/*
* Copyright 2015-2019 Arm Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "spirv_glsl.hpp"
#include "GLSL.std.450.h"
#include "spirv_common.hpp"
#include <algorithm>
#include <assert.h>
#include <cmath>
#include <limits>
#include <locale.h>
#include <utility>
#ifndef _WIN32
#include <langinfo.h>
#endif
#include <locale.h>
#ifdef RARCH_INTERNAL
#include <retro_miscellaneous.h>
#endif
using namespace spv;
using namespace SPIRV_CROSS_NAMESPACE;
using namespace std;
static bool is_unsigned_opcode(Op op)
{
// Don't have to be exhaustive, only relevant for legacy target checking ...
switch (op)
{
case OpShiftRightLogical:
case OpUGreaterThan:
case OpUGreaterThanEqual:
case OpULessThan:
case OpULessThanEqual:
case OpUConvert:
case OpUDiv:
case OpUMod:
case OpUMulExtended:
case OpConvertUToF:
case OpConvertFToU:
return true;
default:
return false;
}
}
static bool is_unsigned_glsl_opcode(GLSLstd450 op)
{
// Don't have to be exhaustive, only relevant for legacy target checking ...
switch (op)
{
case GLSLstd450UClamp:
case GLSLstd450UMin:
case GLSLstd450UMax:
case GLSLstd450FindUMsb:
return true;
default:
return false;
}
}
static bool packing_is_vec4_padded(BufferPackingStandard packing)
{
switch (packing)
{
case BufferPackingHLSLCbuffer:
case BufferPackingHLSLCbufferPackOffset:
case BufferPackingStd140:
case BufferPackingStd140EnhancedLayout:
return true;
default:
return false;
}
}
static bool packing_is_hlsl(BufferPackingStandard packing)
{
switch (packing)
{
case BufferPackingHLSLCbuffer:
case BufferPackingHLSLCbufferPackOffset:
return true;
default:
return false;
}
}
static bool packing_has_flexible_offset(BufferPackingStandard packing)
{
switch (packing)
{
case BufferPackingStd140:
case BufferPackingStd430:
case BufferPackingScalar:
case BufferPackingHLSLCbuffer:
return false;
default:
return true;
}
}
static bool packing_is_scalar(BufferPackingStandard packing)
{
switch (packing)
{
case BufferPackingScalar:
case BufferPackingScalarEnhancedLayout:
return true;
default:
return false;
}
}
static BufferPackingStandard packing_to_substruct_packing(BufferPackingStandard packing)
{
switch (packing)
{
case BufferPackingStd140EnhancedLayout:
return BufferPackingStd140;
case BufferPackingStd430EnhancedLayout:
return BufferPackingStd430;
case BufferPackingHLSLCbufferPackOffset:
return BufferPackingHLSLCbuffer;
case BufferPackingScalarEnhancedLayout:
return BufferPackingScalar;
default:
return packing;
}
}
// Sanitizes underscores for GLSL where multiple underscores in a row are not allowed.
string CompilerGLSL::sanitize_underscores(const string &str)
{
string res;
res.reserve(str.size());
bool last_underscore = false;
for (auto c : str)
{
if (c == '_')
{
if (last_underscore)
continue;
res += c;
last_underscore = true;
}
else
{
res += c;
last_underscore = false;
}
}
return res;
}
void CompilerGLSL::init()
{
if (ir.source.known)
{
options.es = ir.source.es;
options.version = ir.source.version;
}
// Query the locale to see what the decimal point is.
// We'll rely on fixing it up ourselves in the rare case we have a comma-as-decimal locale
// rather than setting locales ourselves. Settings locales in a safe and isolated way is rather
// tricky.
#ifdef _WIN32
// On Windows, localeconv uses thread-local storage, so it should be fine.
const struct lconv *conv = localeconv();
if (conv && conv->decimal_point)
current_locale_radix_character = *conv->decimal_point;
#elif defined(__ANDROID__) && __ANDROID_API__ < 26
// nl_langinfo is not supported on this platform, fall back to the worse alternative.
const struct lconv *conv = localeconv();
if (conv && conv->decimal_point)
current_locale_radix_character = *conv->decimal_point;
#else
// localeconv, the portable function is not MT safe ...
const char *decimal_point = nl_langinfo(RADIXCHAR);
if (decimal_point && *decimal_point != '\0')
current_locale_radix_character = *decimal_point;
#endif
}
static const char *to_pls_layout(PlsFormat format)
{
switch (format)
{
case PlsR11FG11FB10F:
return "layout(r11f_g11f_b10f) ";
case PlsR32F:
return "layout(r32f) ";
case PlsRG16F:
return "layout(rg16f) ";
case PlsRGB10A2:
return "layout(rgb10_a2) ";
case PlsRGBA8:
return "layout(rgba8) ";
case PlsRG16:
return "layout(rg16) ";
case PlsRGBA8I:
return "layout(rgba8i)";
case PlsRG16I:
return "layout(rg16i) ";
case PlsRGB10A2UI:
return "layout(rgb10_a2ui) ";
case PlsRGBA8UI:
return "layout(rgba8ui) ";
case PlsRG16UI:
return "layout(rg16ui) ";
case PlsR32UI:
return "layout(r32ui) ";
default:
return "";
}
}
static SPIRType::BaseType pls_format_to_basetype(PlsFormat format)
{
switch (format)
{
default:
case PlsR11FG11FB10F:
case PlsR32F:
case PlsRG16F:
case PlsRGB10A2:
case PlsRGBA8:
case PlsRG16:
return SPIRType::Float;
case PlsRGBA8I:
case PlsRG16I:
return SPIRType::Int;
case PlsRGB10A2UI:
case PlsRGBA8UI:
case PlsRG16UI:
case PlsR32UI:
return SPIRType::UInt;
}
}
static uint32_t pls_format_to_components(PlsFormat format)
{
switch (format)
{
default:
case PlsR32F:
case PlsR32UI:
return 1;
case PlsRG16F:
case PlsRG16:
case PlsRG16UI:
case PlsRG16I:
return 2;
case PlsR11FG11FB10F:
return 3;
case PlsRGB10A2:
case PlsRGBA8:
case PlsRGBA8I:
case PlsRGB10A2UI:
case PlsRGBA8UI:
return 4;
}
}
static const char *vector_swizzle(int vecsize, int index)
{
static const char *const swizzle[4][4] = {
{ ".x", ".y", ".z", ".w" },
{ ".xy", ".yz", ".zw", nullptr },
{ ".xyz", ".yzw", nullptr, nullptr },
#if defined(__GNUC__) && (__GNUC__ == 9)
// This works around a GCC 9 bug, see details in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90947.
// This array ends up being compiled as all nullptrs, tripping the assertions below.
{ "", nullptr, nullptr, "$" },
#else
{ "", nullptr, nullptr, nullptr },
#endif
};
assert(vecsize >= 1 && vecsize <= 4);
assert(index >= 0 && index < 4);
assert(swizzle[vecsize - 1][index]);
return swizzle[vecsize - 1][index];
}
void CompilerGLSL::reset()
{
// We do some speculative optimizations which should pretty much always work out,
// but just in case the SPIR-V is rather weird, recompile until it's happy.
// This typically only means one extra pass.
clear_force_recompile();
// Clear invalid expression tracking.
invalid_expressions.clear();
current_function = nullptr;
// Clear temporary usage tracking.
expression_usage_counts.clear();
forwarded_temporaries.clear();
reset_name_caches();
ir.for_each_typed_id<SPIRFunction>([&](uint32_t, SPIRFunction &func) {
func.active = false;
func.flush_undeclared = true;
});
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) { var.dependees.clear(); });
ir.reset_all_of_type<SPIRExpression>();
ir.reset_all_of_type<SPIRAccessChain>();
statement_count = 0;
indent = 0;
}
void CompilerGLSL::remap_pls_variables()
{
for (auto &input : pls_inputs)
{
auto &var = get<SPIRVariable>(input.id);
bool input_is_target = false;
if (var.storage == StorageClassUniformConstant)
{
auto &type = get<SPIRType>(var.basetype);
input_is_target = type.image.dim == DimSubpassData;
}
if (var.storage != StorageClassInput && !input_is_target)
SPIRV_CROSS_THROW("Can only use in and target variables for PLS inputs.");
var.remapped_variable = true;
}
for (auto &output : pls_outputs)
{
auto &var = get<SPIRVariable>(output.id);
if (var.storage != StorageClassOutput)
SPIRV_CROSS_THROW("Can only use out variables for PLS outputs.");
var.remapped_variable = true;
}
}
void CompilerGLSL::find_static_extensions()
{
ir.for_each_typed_id<SPIRType>([&](uint32_t, const SPIRType &type) {
if (type.basetype == SPIRType::Double)
{
if (options.es)
SPIRV_CROSS_THROW("FP64 not supported in ES profile.");
if (!options.es && options.version < 400)
require_extension_internal("GL_ARB_gpu_shader_fp64");
}
else if (type.basetype == SPIRType::Int64 || type.basetype == SPIRType::UInt64)
{
if (options.es)
SPIRV_CROSS_THROW("64-bit integers not supported in ES profile.");
if (!options.es)
require_extension_internal("GL_ARB_gpu_shader_int64");
}
else if (type.basetype == SPIRType::Half)
{
require_extension_internal("GL_EXT_shader_explicit_arithmetic_types_float16");
if (options.vulkan_semantics)
require_extension_internal("GL_EXT_shader_16bit_storage");
}
else if (type.basetype == SPIRType::SByte || type.basetype == SPIRType::UByte)
{
require_extension_internal("GL_EXT_shader_explicit_arithmetic_types_int8");
if (options.vulkan_semantics)
require_extension_internal("GL_EXT_shader_8bit_storage");
}
else if (type.basetype == SPIRType::Short || type.basetype == SPIRType::UShort)
{
require_extension_internal("GL_EXT_shader_explicit_arithmetic_types_int16");
if (options.vulkan_semantics)
require_extension_internal("GL_EXT_shader_16bit_storage");
}
});
auto &execution = get_entry_point();
switch (execution.model)
{
case ExecutionModelGLCompute:
if (!options.es && options.version < 430)
require_extension_internal("GL_ARB_compute_shader");
if (options.es && options.version < 310)
SPIRV_CROSS_THROW("At least ESSL 3.10 required for compute shaders.");
break;
case ExecutionModelGeometry:
if (options.es && options.version < 320)
require_extension_internal("GL_EXT_geometry_shader");
if (!options.es && options.version < 150)
require_extension_internal("GL_ARB_geometry_shader4");
if (execution.flags.get(ExecutionModeInvocations) && execution.invocations != 1)
{
// Instanced GS is part of 400 core or this extension.
if (!options.es && options.version < 400)
require_extension_internal("GL_ARB_gpu_shader5");
}
break;
case ExecutionModelTessellationEvaluation:
case ExecutionModelTessellationControl:
if (options.es && options.version < 320)
require_extension_internal("GL_EXT_tessellation_shader");
if (!options.es && options.version < 400)
require_extension_internal("GL_ARB_tessellation_shader");
break;
case ExecutionModelRayGenerationNV:
case ExecutionModelIntersectionNV:
case ExecutionModelAnyHitNV:
case ExecutionModelClosestHitNV:
case ExecutionModelMissNV:
case ExecutionModelCallableNV:
if (options.es || options.version < 460)
SPIRV_CROSS_THROW("Ray tracing shaders require non-es profile with version 460 or above.");
require_extension_internal("GL_NV_ray_tracing");
break;
default:
break;
}
if (!pls_inputs.empty() || !pls_outputs.empty())
require_extension_internal("GL_EXT_shader_pixel_local_storage");
if (options.separate_shader_objects && !options.es && options.version < 410)
require_extension_internal("GL_ARB_separate_shader_objects");
if (ir.addressing_model == AddressingModelPhysicalStorageBuffer64EXT)
{
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("GL_EXT_buffer_reference is only supported in Vulkan GLSL.");
if (options.es && options.version < 320)
SPIRV_CROSS_THROW("GL_EXT_buffer_reference requires ESSL 320.");
else if (!options.es && options.version < 450)
SPIRV_CROSS_THROW("GL_EXT_buffer_reference requires GLSL 450.");
require_extension_internal("GL_EXT_buffer_reference");
}
else if (ir.addressing_model != AddressingModelLogical)
{
SPIRV_CROSS_THROW("Only Logical and PhysicalStorageBuffer64EXT addressing models are supported.");
}
// Check for nonuniform qualifier.
// Instead of looping over all decorations to find this, just look at capabilities.
for (auto &cap : ir.declared_capabilities)
{
bool nonuniform_indexing = false;
switch (cap)
{
case CapabilityShaderNonUniformEXT:
case CapabilityRuntimeDescriptorArrayEXT:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("GL_EXT_nonuniform_qualifier is only supported in Vulkan GLSL.");
require_extension_internal("GL_EXT_nonuniform_qualifier");
nonuniform_indexing = true;
break;
default:
break;
}
if (nonuniform_indexing)
break;
}
}
string CompilerGLSL::compile()
{
if (options.vulkan_semantics)
backend.allow_precision_qualifiers = true;
backend.force_gl_in_out_block = true;
backend.supports_extensions = true;
// Scan the SPIR-V to find trivial uses of extensions.
fixup_type_alias();
reorder_type_alias();
build_function_control_flow_graphs_and_analyze();
find_static_extensions();
fixup_image_load_store_access();
update_active_builtins();
analyze_image_and_sampler_usage();
// Shaders might cast unrelated data to pointers of non-block types.
// Find all such instances and make sure we can cast the pointers to a synthesized block type.
if (ir.addressing_model == AddressingModelPhysicalStorageBuffer64EXT)
analyze_non_block_pointer_types();
uint32_t pass_count = 0;
do
{
if (pass_count >= 3)
SPIRV_CROSS_THROW("Over 3 compilation loops detected. Must be a bug!");
reset();
buffer.reset();
emit_header();
emit_resources();
emit_function(get<SPIRFunction>(ir.default_entry_point), Bitset());
pass_count++;
} while (is_forcing_recompilation());
// Entry point in GLSL is always main().
get_entry_point().name = "main";
return buffer.str();
}
std::string CompilerGLSL::get_partial_source()
{
return buffer.str();
}
void CompilerGLSL::build_workgroup_size(SmallVector<string> &arguments, const SpecializationConstant &wg_x,
const SpecializationConstant &wg_y, const SpecializationConstant &wg_z)
{
auto &execution = get_entry_point();
if (wg_x.id)
{
if (options.vulkan_semantics)
arguments.push_back(join("local_size_x_id = ", wg_x.constant_id));
else
arguments.push_back(join("local_size_x = ", get<SPIRConstant>(wg_x.id).specialization_constant_macro_name));
}
else
arguments.push_back(join("local_size_x = ", execution.workgroup_size.x));
if (wg_y.id)
{
if (options.vulkan_semantics)
arguments.push_back(join("local_size_y_id = ", wg_y.constant_id));
else
arguments.push_back(join("local_size_y = ", get<SPIRConstant>(wg_y.id).specialization_constant_macro_name));
}
else
arguments.push_back(join("local_size_y = ", execution.workgroup_size.y));
if (wg_z.id)
{
if (options.vulkan_semantics)
arguments.push_back(join("local_size_z_id = ", wg_z.constant_id));
else
arguments.push_back(join("local_size_z = ", get<SPIRConstant>(wg_z.id).specialization_constant_macro_name));
}
else
arguments.push_back(join("local_size_z = ", execution.workgroup_size.z));
}
void CompilerGLSL::emit_header()
{
auto &execution = get_entry_point();
statement("#version ", options.version, options.es && options.version > 100 ? " es" : "");
if (!options.es && options.version < 420)
{
// Needed for binding = # on UBOs, etc.
if (options.enable_420pack_extension)
{
statement("#ifdef GL_ARB_shading_language_420pack");
statement("#extension GL_ARB_shading_language_420pack : require");
statement("#endif");
}
// Needed for: layout(early_fragment_tests) in;
if (execution.flags.get(ExecutionModeEarlyFragmentTests))
require_extension_internal("GL_ARB_shader_image_load_store");
}
for (auto &ext : forced_extensions)
{
if (ext == "GL_EXT_shader_explicit_arithmetic_types_float16")
{
// Special case, this extension has a potential fallback to another vendor extension in normal GLSL.
// GL_AMD_gpu_shader_half_float is a superset, so try that first.
statement("#if defined(GL_AMD_gpu_shader_half_float)");
statement("#extension GL_AMD_gpu_shader_half_float : require");
if (!options.vulkan_semantics)
{
statement("#elif defined(GL_NV_gpu_shader5)");
statement("#extension GL_NV_gpu_shader5 : require");
}
else
{
statement("#elif defined(GL_EXT_shader_explicit_arithmetic_types_float16)");
statement("#extension GL_EXT_shader_explicit_arithmetic_types_float16 : require");
}
statement("#else");
statement("#error No extension available for FP16.");
statement("#endif");
}
else if (ext == "GL_EXT_shader_explicit_arithmetic_types_int16")
{
if (options.vulkan_semantics)
statement("#extension GL_EXT_shader_explicit_arithmetic_types_int16 : require");
else
{
statement("#if defined(GL_AMD_gpu_shader_int16)");
statement("#extension GL_AMD_gpu_shader_int16 : require");
statement("#else");
statement("#error No extension available for Int16.");
statement("#endif");
}
}
else
statement("#extension ", ext, " : require");
}
for (auto &header : header_lines)
statement(header);
SmallVector<string> inputs;
SmallVector<string> outputs;
switch (execution.model)
{
case ExecutionModelGeometry:
outputs.push_back(join("max_vertices = ", execution.output_vertices));
if ((execution.flags.get(ExecutionModeInvocations)) && execution.invocations != 1)
inputs.push_back(join("invocations = ", execution.invocations));
if (execution.flags.get(ExecutionModeInputPoints))
inputs.push_back("points");
if (execution.flags.get(ExecutionModeInputLines))
inputs.push_back("lines");
if (execution.flags.get(ExecutionModeInputLinesAdjacency))
inputs.push_back("lines_adjacency");
if (execution.flags.get(ExecutionModeTriangles))
inputs.push_back("triangles");
if (execution.flags.get(ExecutionModeInputTrianglesAdjacency))
inputs.push_back("triangles_adjacency");
if (execution.flags.get(ExecutionModeOutputTriangleStrip))
outputs.push_back("triangle_strip");
if (execution.flags.get(ExecutionModeOutputPoints))
outputs.push_back("points");
if (execution.flags.get(ExecutionModeOutputLineStrip))
outputs.push_back("line_strip");
break;
case ExecutionModelTessellationControl:
if (execution.flags.get(ExecutionModeOutputVertices))
outputs.push_back(join("vertices = ", execution.output_vertices));
break;
case ExecutionModelTessellationEvaluation:
if (execution.flags.get(ExecutionModeQuads))
inputs.push_back("quads");
if (execution.flags.get(ExecutionModeTriangles))
inputs.push_back("triangles");
if (execution.flags.get(ExecutionModeIsolines))
inputs.push_back("isolines");
if (execution.flags.get(ExecutionModePointMode))
inputs.push_back("point_mode");
if (!execution.flags.get(ExecutionModeIsolines))
{
if (execution.flags.get(ExecutionModeVertexOrderCw))
inputs.push_back("cw");
if (execution.flags.get(ExecutionModeVertexOrderCcw))
inputs.push_back("ccw");
}
if (execution.flags.get(ExecutionModeSpacingFractionalEven))
inputs.push_back("fractional_even_spacing");
if (execution.flags.get(ExecutionModeSpacingFractionalOdd))
inputs.push_back("fractional_odd_spacing");
if (execution.flags.get(ExecutionModeSpacingEqual))
inputs.push_back("equal_spacing");
break;
case ExecutionModelGLCompute:
{
if (execution.workgroup_size.constant != 0)
{
SpecializationConstant wg_x, wg_y, wg_z;
get_work_group_size_specialization_constants(wg_x, wg_y, wg_z);
// If there are any spec constants on legacy GLSL, defer declaration, we need to set up macro
// declarations before we can emit the work group size.
if (options.vulkan_semantics || ((wg_x.id == 0) && (wg_y.id == 0) && (wg_z.id == 0)))
build_workgroup_size(inputs, wg_x, wg_y, wg_z);
}
else
{
inputs.push_back(join("local_size_x = ", execution.workgroup_size.x));
inputs.push_back(join("local_size_y = ", execution.workgroup_size.y));
inputs.push_back(join("local_size_z = ", execution.workgroup_size.z));
}
break;
}
case ExecutionModelFragment:
if (options.es)
{
switch (options.fragment.default_float_precision)
{
case Options::Lowp:
statement("precision lowp float;");
break;
case Options::Mediump:
statement("precision mediump float;");
break;
case Options::Highp:
statement("precision highp float;");
break;
default:
break;
}
switch (options.fragment.default_int_precision)
{
case Options::Lowp:
statement("precision lowp int;");
break;
case Options::Mediump:
statement("precision mediump int;");
break;
case Options::Highp:
statement("precision highp int;");
break;
default:
break;
}
}
if (execution.flags.get(ExecutionModeEarlyFragmentTests))
inputs.push_back("early_fragment_tests");
if (!options.es && execution.flags.get(ExecutionModeDepthGreater))
statement("layout(depth_greater) out float gl_FragDepth;");
else if (!options.es && execution.flags.get(ExecutionModeDepthLess))
statement("layout(depth_less) out float gl_FragDepth;");
break;
default:
break;
}
if (!inputs.empty())
statement("layout(", merge(inputs), ") in;");
if (!outputs.empty())
statement("layout(", merge(outputs), ") out;");
statement("");
}
bool CompilerGLSL::type_is_empty(const SPIRType &type)
{
return type.basetype == SPIRType::Struct && type.member_types.empty();
}
void CompilerGLSL::emit_struct(SPIRType &type)
{
// Struct types can be stamped out multiple times
// with just different offsets, matrix layouts, etc ...
// Type-punning with these types is legal, which complicates things
// when we are storing struct and array types in an SSBO for example.
// If the type master is packed however, we can no longer assume that the struct declaration will be redundant.
if (type.type_alias != 0 && !has_extended_decoration(type.type_alias, SPIRVCrossDecorationPacked))
return;
add_resource_name(type.self);
auto name = type_to_glsl(type);
statement(!backend.explicit_struct_type ? "struct " : "", name);
begin_scope();
type.member_name_cache.clear();
uint32_t i = 0;
bool emitted = false;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
emitted = true;
}
// Don't declare empty structs in GLSL, this is not allowed.
if (type_is_empty(type) && !backend.supports_empty_struct)
{
statement("int empty_struct_member;");
emitted = true;
}
end_scope_decl();
if (emitted)
statement("");
}
string CompilerGLSL::to_interpolation_qualifiers(const Bitset &flags)
{
string res;
//if (flags & (1ull << DecorationSmooth))
// res += "smooth ";
if (flags.get(DecorationFlat))
res += "flat ";
if (flags.get(DecorationNoPerspective))
res += "noperspective ";
if (flags.get(DecorationCentroid))
res += "centroid ";
if (flags.get(DecorationPatch))
res += "patch ";
if (flags.get(DecorationSample))
res += "sample ";
if (flags.get(DecorationInvariant))
res += "invariant ";
if (flags.get(DecorationExplicitInterpAMD))
res += "__explicitInterpAMD ";
return res;
}
string CompilerGLSL::layout_for_member(const SPIRType &type, uint32_t index)
{
if (is_legacy())
return "";
bool is_block = ir.meta[type.self].decoration.decoration_flags.get(DecorationBlock) ||
ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock);
if (!is_block)
return "";
auto &memb = ir.meta[type.self].members;
if (index >= memb.size())
return "";
auto &dec = memb[index];
SmallVector<string> attr;
// We can only apply layouts on members in block interfaces.
// This is a bit problematic because in SPIR-V decorations are applied on the struct types directly.
// This is not supported on GLSL, so we have to make the assumption that if a struct within our buffer block struct
// has a decoration, it was originally caused by a top-level layout() qualifier in GLSL.
//
// We would like to go from (SPIR-V style):
//
// struct Foo { layout(row_major) mat4 matrix; };
// buffer UBO { Foo foo; };
//
// to
//
// struct Foo { mat4 matrix; }; // GLSL doesn't support any layout shenanigans in raw struct declarations.
// buffer UBO { layout(row_major) Foo foo; }; // Apply the layout on top-level.
auto flags = combined_decoration_for_member(type, index);
if (flags.get(DecorationRowMajor))
attr.push_back("row_major");
// We don't emit any global layouts, so column_major is default.
//if (flags & (1ull << DecorationColMajor))
// attr.push_back("column_major");
if (dec.decoration_flags.get(DecorationLocation) && can_use_io_location(type.storage, true))
attr.push_back(join("location = ", dec.location));
// Can only declare component if we can declare location.
if (dec.decoration_flags.get(DecorationComponent) && can_use_io_location(type.storage, true))
{
if (!options.es)
{
if (options.version < 440 && options.version >= 140)
require_extension_internal("GL_ARB_enhanced_layouts");
else if (options.version < 140)
SPIRV_CROSS_THROW("Component decoration is not supported in targets below GLSL 1.40.");
attr.push_back(join("component = ", dec.component));
}
else
SPIRV_CROSS_THROW("Component decoration is not supported in ES targets.");
}
// SPIRVCrossDecorationPacked is set by layout_for_variable earlier to mark that we need to emit offset qualifiers.
// This is only done selectively in GLSL as needed.
if (has_extended_decoration(type.self, SPIRVCrossDecorationPacked) && dec.decoration_flags.get(DecorationOffset))
attr.push_back(join("offset = ", dec.offset));
if (attr.empty())
return "";
string res = "layout(";
res += merge(attr);
res += ") ";
return res;
}
const char *CompilerGLSL::format_to_glsl(spv::ImageFormat format)
{
if (options.es && is_desktop_only_format(format))
SPIRV_CROSS_THROW("Attempting to use image format not supported in ES profile.");
switch (format)
{
case ImageFormatRgba32f:
return "rgba32f";
case ImageFormatRgba16f:
return "rgba16f";
case ImageFormatR32f:
return "r32f";
case ImageFormatRgba8:
return "rgba8";
case ImageFormatRgba8Snorm:
return "rgba8_snorm";
case ImageFormatRg32f:
return "rg32f";
case ImageFormatRg16f:
return "rg16f";
case ImageFormatRgba32i:
return "rgba32i";
case ImageFormatRgba16i:
return "rgba16i";
case ImageFormatR32i:
return "r32i";
case ImageFormatRgba8i:
return "rgba8i";
case ImageFormatRg32i:
return "rg32i";
case ImageFormatRg16i:
return "rg16i";
case ImageFormatRgba32ui:
return "rgba32ui";
case ImageFormatRgba16ui:
return "rgba16ui";
case ImageFormatR32ui:
return "r32ui";
case ImageFormatRgba8ui:
return "rgba8ui";
case ImageFormatRg32ui:
return "rg32ui";
case ImageFormatRg16ui:
return "rg16ui";
case ImageFormatR11fG11fB10f:
return "r11f_g11f_b10f";
case ImageFormatR16f:
return "r16f";
case ImageFormatRgb10A2:
return "rgb10_a2";
case ImageFormatR8:
return "r8";
case ImageFormatRg8:
return "rg8";
case ImageFormatR16:
return "r16";
case ImageFormatRg16:
return "rg16";
case ImageFormatRgba16:
return "rgba16";
case ImageFormatR16Snorm:
return "r16_snorm";
case ImageFormatRg16Snorm:
return "rg16_snorm";
case ImageFormatRgba16Snorm:
return "rgba16_snorm";
case ImageFormatR8Snorm:
return "r8_snorm";
case ImageFormatRg8Snorm:
return "rg8_snorm";
case ImageFormatR8ui:
return "r8ui";
case ImageFormatRg8ui:
return "rg8ui";
case ImageFormatR16ui:
return "r16ui";
case ImageFormatRgb10a2ui:
return "rgb10_a2ui";
case ImageFormatR8i:
return "r8i";
case ImageFormatRg8i:
return "rg8i";
case ImageFormatR16i:
return "r16i";
default:
case ImageFormatUnknown:
return nullptr;
}
}
uint32_t CompilerGLSL::type_to_packed_base_size(const SPIRType &type, BufferPackingStandard)
{
switch (type.basetype)
{
case SPIRType::Double:
case SPIRType::Int64:
case SPIRType::UInt64:
return 8;
case SPIRType::Float:
case SPIRType::Int:
case SPIRType::UInt:
return 4;
case SPIRType::Half:
case SPIRType::Short:
case SPIRType::UShort:
return 2;
case SPIRType::SByte:
case SPIRType::UByte:
return 1;
default:
SPIRV_CROSS_THROW("Unrecognized type in type_to_packed_base_size.");
}
}
uint32_t CompilerGLSL::type_to_packed_alignment(const SPIRType &type, const Bitset &flags,
BufferPackingStandard packing)
{
// If using PhysicalStorageBufferEXT storage class, this is a pointer,
// and is 64-bit.
if (type.storage == StorageClassPhysicalStorageBufferEXT)
{
if (!type.pointer)
SPIRV_CROSS_THROW("Types in PhysicalStorageBufferEXT must be pointers.");
if (ir.addressing_model == AddressingModelPhysicalStorageBuffer64EXT)
{
if (packing_is_vec4_padded(packing) && type_is_array_of_pointers(type))
return 16;
else
return 8;
}
else
SPIRV_CROSS_THROW("AddressingModelPhysicalStorageBuffer64EXT must be used for PhysicalStorageBufferEXT.");
}
if (!type.array.empty())
{
uint32_t minimum_alignment = 1;
if (packing_is_vec4_padded(packing))
minimum_alignment = 16;
auto *tmp = &get<SPIRType>(type.parent_type);
while (!tmp->array.empty())
tmp = &get<SPIRType>(tmp->parent_type);
// Get the alignment of the base type, then maybe round up.
return max(minimum_alignment, type_to_packed_alignment(*tmp, flags, packing));
}
if (type.basetype == SPIRType::Struct)
{
// Rule 9. Structs alignments are maximum alignment of its members.
uint32_t alignment = 1;
for (uint32_t i = 0; i < type.member_types.size(); i++)
{
auto member_flags = ir.meta[type.self].members[i].decoration_flags;
alignment =
max(alignment, type_to_packed_alignment(get<SPIRType>(type.member_types[i]), member_flags, packing));
}
// In std140, struct alignment is rounded up to 16.
if (packing_is_vec4_padded(packing))
#if defined(RARCH_INTERNAL)
alignment = MAX(alignment, 16u);
#else
alignment = max(alignment, 16u);
#endif
return alignment;
}
else
{
const uint32_t base_alignment = type_to_packed_base_size(type, packing);
// Alignment requirement for scalar block layout is always the alignment for the most basic component.
if (packing_is_scalar(packing))
return base_alignment;
// Vectors are *not* aligned in HLSL, but there's an extra rule where vectors cannot straddle
// a vec4, this is handled outside since that part knows our current offset.
if (type.columns == 1 && packing_is_hlsl(packing))
return base_alignment;
// From 7.6.2.2 in GL 4.5 core spec.
// Rule 1
if (type.vecsize == 1 && type.columns == 1)
return base_alignment;
// Rule 2
if ((type.vecsize == 2 || type.vecsize == 4) && type.columns == 1)
return type.vecsize * base_alignment;
// Rule 3
if (type.vecsize == 3 && type.columns == 1)
return 4 * base_alignment;
// Rule 4 implied. Alignment does not change in std430.
// Rule 5. Column-major matrices are stored as arrays of
// vectors.
if (flags.get(DecorationColMajor) && type.columns > 1)
{
if (packing_is_vec4_padded(packing))
return 4 * base_alignment;
else if (type.vecsize == 3)
return 4 * base_alignment;
else
return type.vecsize * base_alignment;
}
// Rule 6 implied.
// Rule 7.
if (flags.get(DecorationRowMajor) && type.vecsize > 1)
{
if (packing_is_vec4_padded(packing))
return 4 * base_alignment;
else if (type.columns == 3)
return 4 * base_alignment;
else
return type.columns * base_alignment;
}
// Rule 8 implied.
}
SPIRV_CROSS_THROW("Did not find suitable rule for type. Bogus decorations?");
}
uint32_t CompilerGLSL::type_to_packed_array_stride(const SPIRType &type, const Bitset &flags,
BufferPackingStandard packing)
{
// Array stride is equal to aligned size of the underlying type.
uint32_t parent = type.parent_type;
assert(parent);
auto &tmp = get<SPIRType>(parent);
uint32_t size = type_to_packed_size(tmp, flags, packing);
if (tmp.array.empty())
{
uint32_t alignment = type_to_packed_alignment(type, flags, packing);
return (size + alignment - 1) & ~(alignment - 1);
}
else
{
// For multidimensional arrays, array stride always matches size of subtype.
// The alignment cannot change because multidimensional arrays are basically N * M array elements.
return size;
}
}
uint32_t CompilerGLSL::type_to_packed_size(const SPIRType &type, const Bitset &flags, BufferPackingStandard packing)
{
if (!type.array.empty())
{
return to_array_size_literal(type) * type_to_packed_array_stride(type, flags, packing);
}
// If using PhysicalStorageBufferEXT storage class, this is a pointer,
// and is 64-bit.
if (type.storage == StorageClassPhysicalStorageBufferEXT)
{
if (!type.pointer)
SPIRV_CROSS_THROW("Types in PhysicalStorageBufferEXT must be pointers.");
if (ir.addressing_model == AddressingModelPhysicalStorageBuffer64EXT)
return 8;
else
SPIRV_CROSS_THROW("AddressingModelPhysicalStorageBuffer64EXT must be used for PhysicalStorageBufferEXT.");
}
uint32_t size = 0;
if (type.basetype == SPIRType::Struct)
{
uint32_t pad_alignment = 1;
for (uint32_t i = 0; i < type.member_types.size(); i++)
{
auto member_flags = ir.meta[type.self].members[i].decoration_flags;
auto &member_type = get<SPIRType>(type.member_types[i]);
uint32_t packed_alignment = type_to_packed_alignment(member_type, member_flags, packing);
uint32_t alignment = max(packed_alignment, pad_alignment);
// The next member following a struct member is aligned to the base alignment of the struct that came before.
// GL 4.5 spec, 7.6.2.2.
if (member_type.basetype == SPIRType::Struct)
pad_alignment = packed_alignment;
else
pad_alignment = 1;
size = (size + alignment - 1) & ~(alignment - 1);
size += type_to_packed_size(member_type, member_flags, packing);
}
}
else
{
const uint32_t base_alignment = type_to_packed_base_size(type, packing);
if (packing_is_scalar(packing))
{
size = type.vecsize * type.columns * base_alignment;
}
else
{
if (type.columns == 1)
size = type.vecsize * base_alignment;
if (flags.get(DecorationColMajor) && type.columns > 1)
{
if (packing_is_vec4_padded(packing))
size = type.columns * 4 * base_alignment;
else if (type.vecsize == 3)
size = type.columns * 4 * base_alignment;
else
size = type.columns * type.vecsize * base_alignment;
}
if (flags.get(DecorationRowMajor) && type.vecsize > 1)
{
if (packing_is_vec4_padded(packing))
size = type.vecsize * 4 * base_alignment;
else if (type.columns == 3)
size = type.vecsize * 4 * base_alignment;
else
size = type.vecsize * type.columns * base_alignment;
}
}
}
return size;
}
bool CompilerGLSL::buffer_is_packing_standard(const SPIRType &type, BufferPackingStandard packing,
uint32_t start_offset, uint32_t end_offset)
{
// This is very tricky and error prone, but try to be exhaustive and correct here.
// SPIR-V doesn't directly say if we're using std430 or std140.
// SPIR-V communicates this using Offset and ArrayStride decorations (which is what really matters),
// so we have to try to infer whether or not the original GLSL source was std140 or std430 based on this information.
// We do not have to consider shared or packed since these layouts are not allowed in Vulkan SPIR-V (they are useless anyways, and custom offsets would do the same thing).
//
// It is almost certain that we're using std430, but it gets tricky with arrays in particular.
// We will assume std430, but infer std140 if we can prove the struct is not compliant with std430.
//
// The only two differences between std140 and std430 are related to padding alignment/array stride
// in arrays and structs. In std140 they take minimum vec4 alignment.
// std430 only removes the vec4 requirement.
uint32_t offset = 0;
uint32_t pad_alignment = 1;
bool is_top_level_block =
has_decoration(type.self, DecorationBlock) || has_decoration(type.self, DecorationBufferBlock);
for (uint32_t i = 0; i < type.member_types.size(); i++)
{
auto &memb_type = get<SPIRType>(type.member_types[i]);
auto member_flags = ir.meta[type.self].members[i].decoration_flags;
// Verify alignment rules.
uint32_t packed_alignment = type_to_packed_alignment(memb_type, member_flags, packing);
// This is a rather dirty workaround to deal with some cases of OpSpecConstantOp used as array size, e.g:
// layout(constant_id = 0) const int s = 10;
// const int S = s + 5; // SpecConstantOp
// buffer Foo { int data[S]; }; // <-- Very hard for us to deduce a fixed value here,
// we would need full implementation of compile-time constant folding. :(
// If we are the last member of a struct, there might be cases where the actual size of that member is irrelevant
// for our analysis (e.g. unsized arrays).
// This lets us simply ignore that there are spec constant op sized arrays in our buffers.
// Querying size of this member will fail, so just don't call it unless we have to.
//
// This is likely "best effort" we can support without going into unacceptably complicated workarounds.
bool member_can_be_unsized =
is_top_level_block && size_t(i + 1) == type.member_types.size() && !memb_type.array.empty();
uint32_t packed_size = 0;
if (!member_can_be_unsized)
packed_size = type_to_packed_size(memb_type, member_flags, packing);
// We only need to care about this if we have non-array types which can straddle the vec4 boundary.
if (packing_is_hlsl(packing))
{
// If a member straddles across a vec4 boundary, alignment is actually vec4.
uint32_t begin_word = offset / 16;
uint32_t end_word = (offset + packed_size - 1) / 16;
if (begin_word != end_word)
#if defined(RARCH_INTERNAL)
packed_alignment = MAX(packed_alignment, 16u);
#else
packed_alignment = max(packed_alignment, 16u);
#endif
}
uint32_t alignment = max(packed_alignment, pad_alignment);
offset = (offset + alignment - 1) & ~(alignment - 1);
// Field is not in the specified range anymore and we can ignore any further fields.
if (offset >= end_offset)
break;
// The next member following a struct member is aligned to the base alignment of the struct that came before.
// GL 4.5 spec, 7.6.2.2.
if (memb_type.basetype == SPIRType::Struct && !memb_type.pointer)
pad_alignment = packed_alignment;
else
pad_alignment = 1;
// Only care about packing if we are in the given range
if (offset >= start_offset)
{
// We only care about offsets in std140, std430, etc ...
// For EnhancedLayout variants, we have the flexibility to choose our own offsets.
if (!packing_has_flexible_offset(packing))
{
uint32_t actual_offset = type_struct_member_offset(type, i);
if (actual_offset != offset) // This cannot be the packing we're looking for.
return false;
}
// Verify array stride rules.
if (!memb_type.array.empty() && type_to_packed_array_stride(memb_type, member_flags, packing) !=
type_struct_member_array_stride(type, i))
return false;
// Verify that sub-structs also follow packing rules.
// We cannot use enhanced layouts on substructs, so they better be up to spec.
auto substruct_packing = packing_to_substruct_packing(packing);
if (!memb_type.pointer && !memb_type.member_types.empty() &&
!buffer_is_packing_standard(memb_type, substruct_packing))
{
return false;
}
}
// Bump size.
offset += packed_size;
}
return true;
}
bool CompilerGLSL::can_use_io_location(StorageClass storage, bool block)
{
// Location specifiers are must have in SPIR-V, but they aren't really supported in earlier versions of GLSL.
// Be very explicit here about how to solve the issue.
if ((get_execution_model() != ExecutionModelVertex && storage == StorageClassInput) ||
(get_execution_model() != ExecutionModelFragment && storage == StorageClassOutput))
{
uint32_t minimum_desktop_version = block ? 440 : 410;
// ARB_enhanced_layouts vs ARB_separate_shader_objects ...
if (!options.es && options.version < minimum_desktop_version && !options.separate_shader_objects)
return false;
else if (options.es && options.version < 310)
return false;
}
if ((get_execution_model() == ExecutionModelVertex && storage == StorageClassInput) ||
(get_execution_model() == ExecutionModelFragment && storage == StorageClassOutput))
{
if (options.es && options.version < 300)
return false;
else if (!options.es && options.version < 330)
return false;
}
if (storage == StorageClassUniform || storage == StorageClassUniformConstant || storage == StorageClassPushConstant)
{
if (options.es && options.version < 310)
return false;
else if (!options.es && options.version < 430)
return false;
}
return true;
}
string CompilerGLSL::layout_for_variable(const SPIRVariable &var)
{
// FIXME: Come up with a better solution for when to disable layouts.
// Having layouts depend on extensions as well as which types
// of layouts are used. For now, the simple solution is to just disable
// layouts for legacy versions.
if (is_legacy())
return "";
SmallVector<string> attr;
auto &dec = ir.meta[var.self].decoration;
auto &type = get<SPIRType>(var.basetype);
auto &flags = dec.decoration_flags;
auto typeflags = ir.meta[type.self].decoration.decoration_flags;
if (options.vulkan_semantics && var.storage == StorageClassPushConstant)
attr.push_back("push_constant");
else if (var.storage == StorageClassShaderRecordBufferNV)
attr.push_back("shaderRecordNV");
if (flags.get(DecorationRowMajor))
attr.push_back("row_major");
if (flags.get(DecorationColMajor))
attr.push_back("column_major");
if (options.vulkan_semantics)
{
if (flags.get(DecorationInputAttachmentIndex))
attr.push_back(join("input_attachment_index = ", dec.input_attachment));
}
bool is_block = has_decoration(type.self, DecorationBlock);
if (flags.get(DecorationLocation) && can_use_io_location(var.storage, is_block))
{
Bitset combined_decoration;
for (uint32_t i = 0; i < ir.meta[type.self].members.size(); i++)
combined_decoration.merge_or(combined_decoration_for_member(type, i));
// If our members have location decorations, we don't need to
// emit location decorations at the top as well (looks weird).
if (!combined_decoration.get(DecorationLocation))
attr.push_back(join("location = ", dec.location));
}
// Can only declare Component if we can declare location.
if (flags.get(DecorationComponent) && can_use_io_location(var.storage, is_block))
{
if (!options.es)
{
if (options.version < 440 && options.version >= 140)
require_extension_internal("GL_ARB_enhanced_layouts");
else if (options.version < 140)
SPIRV_CROSS_THROW("Component decoration is not supported in targets below GLSL 1.40.");
attr.push_back(join("component = ", dec.component));
}
else
SPIRV_CROSS_THROW("Component decoration is not supported in ES targets.");
}
if (flags.get(DecorationIndex))
attr.push_back(join("index = ", dec.index));
// Do not emit set = decoration in regular GLSL output, but
// we need to preserve it in Vulkan GLSL mode.
if (var.storage != StorageClassPushConstant && var.storage != StorageClassShaderRecordBufferNV)
{
if (flags.get(DecorationDescriptorSet) && options.vulkan_semantics)
attr.push_back(join("set = ", dec.set));
}
bool push_constant_block = options.vulkan_semantics && var.storage == StorageClassPushConstant;
bool ssbo_block = var.storage == StorageClassStorageBuffer || var.storage == StorageClassShaderRecordBufferNV ||
(var.storage == StorageClassUniform && typeflags.get(DecorationBufferBlock));
bool emulated_ubo = var.storage == StorageClassPushConstant && options.emit_push_constant_as_uniform_buffer;
bool ubo_block = var.storage == StorageClassUniform && typeflags.get(DecorationBlock);
// GL 3.0/GLSL 1.30 is not considered legacy, but it doesn't have UBOs ...
bool can_use_buffer_blocks = (options.es && options.version >= 300) || (!options.es && options.version >= 140);
// pretend no UBOs when options say so
if (ubo_block && options.emit_uniform_buffer_as_plain_uniforms)
can_use_buffer_blocks = false;
bool can_use_binding;
if (options.es)
can_use_binding = options.version >= 310;
else
can_use_binding = options.enable_420pack_extension || (options.version >= 420);
// Make sure we don't emit binding layout for a classic uniform on GLSL 1.30.
if (!can_use_buffer_blocks && var.storage == StorageClassUniform)
can_use_binding = false;
if (var.storage == StorageClassShaderRecordBufferNV)
can_use_binding = false;
if (can_use_binding && flags.get(DecorationBinding))
attr.push_back(join("binding = ", dec.binding));
if (flags.get(DecorationOffset))
attr.push_back(join("offset = ", dec.offset));
// Instead of adding explicit offsets for every element here, just assume we're using std140 or std430.
// If SPIR-V does not comply with either layout, we cannot really work around it.
if (can_use_buffer_blocks && (ubo_block || emulated_ubo))
{
attr.push_back(buffer_to_packing_standard(type, false));
}
else if (can_use_buffer_blocks && (push_constant_block || ssbo_block))
{
attr.push_back(buffer_to_packing_standard(type, true));
}
// For images, the type itself adds a layout qualifer.
// Only emit the format for storage images.
if (type.basetype == SPIRType::Image && type.image.sampled == 2)
{
const char *fmt = format_to_glsl(type.image.format);
if (fmt)
attr.push_back(fmt);
}
if (attr.empty())
return "";
string res = "layout(";
res += merge(attr);
res += ") ";
return res;
}
string CompilerGLSL::buffer_to_packing_standard(const SPIRType &type, bool support_std430_without_scalar_layout)
{
if (support_std430_without_scalar_layout && buffer_is_packing_standard(type, BufferPackingStd430))
return "std430";
else if (buffer_is_packing_standard(type, BufferPackingStd140))
return "std140";
else if (options.vulkan_semantics && buffer_is_packing_standard(type, BufferPackingScalar))
{
require_extension_internal("GL_EXT_scalar_block_layout");
return "scalar";
}
else if (support_std430_without_scalar_layout &&
buffer_is_packing_standard(type, BufferPackingStd430EnhancedLayout))
{
if (options.es && !options.vulkan_semantics)
SPIRV_CROSS_THROW("Push constant block cannot be expressed as neither std430 nor std140. ES-targets do "
"not support GL_ARB_enhanced_layouts.");
if (!options.es && !options.vulkan_semantics && options.version < 440)
require_extension_internal("GL_ARB_enhanced_layouts");
set_extended_decoration(type.self, SPIRVCrossDecorationPacked);
return "std430";
}
else if (buffer_is_packing_standard(type, BufferPackingStd140EnhancedLayout))
{
// Fallback time. We might be able to use the ARB_enhanced_layouts to deal with this difference,
// however, we can only use layout(offset) on the block itself, not any substructs, so the substructs better be the appropriate layout.
// Enhanced layouts seem to always work in Vulkan GLSL, so no need for extensions there.
if (options.es && !options.vulkan_semantics)
SPIRV_CROSS_THROW("Push constant block cannot be expressed as neither std430 nor std140. ES-targets do "
"not support GL_ARB_enhanced_layouts.");
if (!options.es && !options.vulkan_semantics && options.version < 440)
require_extension_internal("GL_ARB_enhanced_layouts");
set_extended_decoration(type.self, SPIRVCrossDecorationPacked);
return "std140";
}
else if (options.vulkan_semantics && buffer_is_packing_standard(type, BufferPackingScalarEnhancedLayout))
{
set_extended_decoration(type.self, SPIRVCrossDecorationPacked);
require_extension_internal("GL_EXT_scalar_block_layout");
return "scalar";
}
else if (!support_std430_without_scalar_layout && options.vulkan_semantics &&
buffer_is_packing_standard(type, BufferPackingStd430))
{
// UBOs can support std430 with GL_EXT_scalar_block_layout.
require_extension_internal("GL_EXT_scalar_block_layout");
return "std430";
}
else if (!support_std430_without_scalar_layout && options.vulkan_semantics &&
buffer_is_packing_standard(type, BufferPackingStd430EnhancedLayout))
{
// UBOs can support std430 with GL_EXT_scalar_block_layout.
set_extended_decoration(type.self, SPIRVCrossDecorationPacked);
require_extension_internal("GL_EXT_scalar_block_layout");
return "std430";
}
else
{
SPIRV_CROSS_THROW("Buffer block cannot be expressed as any of std430, std140, scalar, even with enhanced "
"layouts. You can try flattening this block to support a more flexible layout.");
}
}
void CompilerGLSL::emit_push_constant_block(const SPIRVariable &var)
{
if (flattened_buffer_blocks.count(var.self))
emit_buffer_block_flattened(var);
else if (options.vulkan_semantics)
emit_push_constant_block_vulkan(var);
else if (options.emit_push_constant_as_uniform_buffer)
emit_buffer_block_native(var);
else
emit_push_constant_block_glsl(var);
}
void CompilerGLSL::emit_push_constant_block_vulkan(const SPIRVariable &var)
{
emit_buffer_block(var);
}
void CompilerGLSL::emit_push_constant_block_glsl(const SPIRVariable &var)
{
// OpenGL has no concept of push constant blocks, implement it as a uniform struct.
auto &type = get<SPIRType>(var.basetype);
auto &flags = ir.meta[var.self].decoration.decoration_flags;
flags.clear(DecorationBinding);
flags.clear(DecorationDescriptorSet);
#if 0
if (flags & ((1ull << DecorationBinding) | (1ull << DecorationDescriptorSet)))
SPIRV_CROSS_THROW("Push constant blocks cannot be compiled to GLSL with Binding or Set syntax. "
"Remap to location with reflection API first or disable these decorations.");
#endif
// We're emitting the push constant block as a regular struct, so disable the block qualifier temporarily.
// Otherwise, we will end up emitting layout() qualifiers on naked structs which is not allowed.
auto &block_flags = ir.meta[type.self].decoration.decoration_flags;
bool block_flag = block_flags.get(DecorationBlock);
block_flags.clear(DecorationBlock);
emit_struct(type);
if (block_flag)
block_flags.set(DecorationBlock);
emit_uniform(var);
statement("");
}
void CompilerGLSL::emit_buffer_block(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
bool ubo_block = var.storage == StorageClassUniform && has_decoration(type.self, DecorationBlock);
if (flattened_buffer_blocks.count(var.self))
emit_buffer_block_flattened(var);
else if (is_legacy() || (!options.es && options.version == 130) ||
(ubo_block && options.emit_uniform_buffer_as_plain_uniforms))
emit_buffer_block_legacy(var);
else
emit_buffer_block_native(var);
}
void CompilerGLSL::emit_buffer_block_legacy(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
bool ssbo = var.storage == StorageClassStorageBuffer ||
ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock);
if (ssbo)
SPIRV_CROSS_THROW("SSBOs not supported in legacy targets.");
// We're emitting the push constant block as a regular struct, so disable the block qualifier temporarily.
// Otherwise, we will end up emitting layout() qualifiers on naked structs which is not allowed.
auto &block_flags = ir.meta[type.self].decoration.decoration_flags;
bool block_flag = block_flags.get(DecorationBlock);
block_flags.clear(DecorationBlock);
emit_struct(type);
if (block_flag)
block_flags.set(DecorationBlock);
emit_uniform(var);
statement("");
}
void CompilerGLSL::emit_buffer_reference_block(SPIRType &type, bool forward_declaration)
{
string buffer_name;
if (forward_declaration)
{
// Block names should never alias, but from HLSL input they kind of can because block types are reused for UAVs ...
// Allow aliased name since we might be declaring the block twice. Once with buffer reference (forward declared) and one proper declaration.
// The names must match up.
buffer_name = to_name(type.self, false);
// Shaders never use the block by interface name, so we don't
// have to track this other than updating name caches.
// If we have a collision for any reason, just fallback immediately.
if (ir.meta[type.self].decoration.alias.empty() ||
block_ssbo_names.find(buffer_name) != end(block_ssbo_names) ||
resource_names.find(buffer_name) != end(resource_names))
{
buffer_name = join("_", type.self);
}
// Make sure we get something unique for both global name scope and block name scope.
// See GLSL 4.5 spec: section 4.3.9 for details.
add_variable(block_ssbo_names, resource_names, buffer_name);
// If for some reason buffer_name is an illegal name, make a final fallback to a workaround name.
// This cannot conflict with anything else, so we're safe now.
// We cannot reuse this fallback name in neither global scope (blocked by block_names) nor block name scope.
if (buffer_name.empty())
buffer_name = join("_", type.self);
block_names.insert(buffer_name);
block_ssbo_names.insert(buffer_name);
}
else if (type.basetype != SPIRType::Struct)
buffer_name = type_to_glsl(type);
else
buffer_name = to_name(type.self, false);
if (!forward_declaration)
{
if (type.basetype == SPIRType::Struct)
statement("layout(buffer_reference, ", buffer_to_packing_standard(type, true), ") buffer ", buffer_name);
else
statement("layout(buffer_reference) buffer ", buffer_name);
begin_scope();
if (type.basetype == SPIRType::Struct)
{
type.member_name_cache.clear();
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
}
}
else
{
auto &pointee_type = get_pointee_type(type);
statement(type_to_glsl(pointee_type), " value", type_to_array_glsl(pointee_type), ";");
}
end_scope_decl();
statement("");
}
else
{
statement("layout(buffer_reference) buffer ", buffer_name, ";");
}
}
void CompilerGLSL::emit_buffer_block_native(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
Bitset flags = ir.get_buffer_block_flags(var);
bool ssbo = var.storage == StorageClassStorageBuffer || var.storage == StorageClassShaderRecordBufferNV ||
ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock);
bool is_restrict = ssbo && flags.get(DecorationRestrict);
bool is_writeonly = ssbo && flags.get(DecorationNonReadable);
bool is_readonly = ssbo && flags.get(DecorationNonWritable);
bool is_coherent = ssbo && flags.get(DecorationCoherent);
// Block names should never alias, but from HLSL input they kind of can because block types are reused for UAVs ...
auto buffer_name = to_name(type.self, false);
auto &block_namespace = ssbo ? block_ssbo_names : block_ubo_names;
// Shaders never use the block by interface name, so we don't
// have to track this other than updating name caches.
// If we have a collision for any reason, just fallback immediately.
if (ir.meta[type.self].decoration.alias.empty() || block_namespace.find(buffer_name) != end(block_namespace) ||
resource_names.find(buffer_name) != end(resource_names))
{
buffer_name = get_block_fallback_name(var.self);
}
// Make sure we get something unique for both global name scope and block name scope.
// See GLSL 4.5 spec: section 4.3.9 for details.
add_variable(block_namespace, resource_names, buffer_name);
// If for some reason buffer_name is an illegal name, make a final fallback to a workaround name.
// This cannot conflict with anything else, so we're safe now.
// We cannot reuse this fallback name in neither global scope (blocked by block_names) nor block name scope.
if (buffer_name.empty())
buffer_name = join("_", get<SPIRType>(var.basetype).self, "_", var.self);
block_names.insert(buffer_name);
block_namespace.insert(buffer_name);
// Save for post-reflection later.
declared_block_names[var.self] = buffer_name;
statement(layout_for_variable(var), is_coherent ? "coherent " : "", is_restrict ? "restrict " : "",
is_writeonly ? "writeonly " : "", is_readonly ? "readonly " : "", ssbo ? "buffer " : "uniform ",
buffer_name);
begin_scope();
type.member_name_cache.clear();
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
}
// var.self can be used as a backup name for the block name,
// so we need to make sure we don't disturb the name here on a recompile.
// It will need to be reset if we have to recompile.
preserve_alias_on_reset(var.self);
add_resource_name(var.self);
end_scope_decl(to_name(var.self) + type_to_array_glsl(type));
statement("");
}
void CompilerGLSL::emit_buffer_block_flattened(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
// Block names should never alias.
auto buffer_name = to_name(type.self, false);
size_t buffer_size = (get_declared_struct_size(type) + 15) / 16;
SPIRType::BaseType basic_type;
if (get_common_basic_type(type, basic_type))
{
SPIRType tmp;
tmp.basetype = basic_type;
tmp.vecsize = 4;
if (basic_type != SPIRType::Float && basic_type != SPIRType::Int && basic_type != SPIRType::UInt)
SPIRV_CROSS_THROW("Basic types in a flattened UBO must be float, int or uint.");
auto flags = ir.get_buffer_block_flags(var);
statement("uniform ", flags_to_qualifiers_glsl(tmp, flags), type_to_glsl(tmp), " ", buffer_name, "[",
buffer_size, "];");
}
else
SPIRV_CROSS_THROW("All basic types in a flattened block must be the same.");
}
const char *CompilerGLSL::to_storage_qualifiers_glsl(const SPIRVariable &var)
{
auto &execution = get_entry_point();
if (var.storage == StorageClassInput || var.storage == StorageClassOutput)
{
if (is_legacy() && execution.model == ExecutionModelVertex)
return var.storage == StorageClassInput ? "attribute " : "varying ";
else if (is_legacy() && execution.model == ExecutionModelFragment)
return "varying "; // Fragment outputs are renamed so they never hit this case.
else
return var.storage == StorageClassInput ? "in " : "out ";
}
else if (var.storage == StorageClassUniformConstant || var.storage == StorageClassUniform ||
var.storage == StorageClassPushConstant)
{
return "uniform ";
}
else if (var.storage == StorageClassRayPayloadNV)
{
return "rayPayloadNV ";
}
else if (var.storage == StorageClassIncomingRayPayloadNV)
{
return "rayPayloadInNV ";
}
else if (var.storage == StorageClassHitAttributeNV)
{
return "hitAttributeNV ";
}
else if (var.storage == StorageClassCallableDataNV)
{
return "callableDataNV ";
}
else if (var.storage == StorageClassIncomingCallableDataNV)
{
return "callableDataInNV ";
}
return "";
}
void CompilerGLSL::emit_flattened_io_block(const SPIRVariable &var, const char *qual)
{
auto &type = get<SPIRType>(var.basetype);
if (!type.array.empty())
SPIRV_CROSS_THROW("Array of varying structs cannot be flattened to legacy-compatible varyings.");
auto old_flags = ir.meta[type.self].decoration.decoration_flags;
// Emit the members as if they are part of a block to get all qualifiers.
ir.meta[type.self].decoration.decoration_flags.set(DecorationBlock);
type.member_name_cache.clear();
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
auto &membertype = get<SPIRType>(member);
if (membertype.basetype == SPIRType::Struct)
SPIRV_CROSS_THROW("Cannot flatten struct inside structs in I/O variables.");
// Pass in the varying qualifier here so it will appear in the correct declaration order.
// Replace member name while emitting it so it encodes both struct name and member name.
// Sanitize underscores because joining the two identifiers might create more than 1 underscore in a row,
// which is not allowed.
auto backup_name = get_member_name(type.self, i);
auto member_name = to_member_name(type, i);
set_member_name(type.self, i, sanitize_underscores(join(to_name(var.self), "_", member_name)));
emit_struct_member(type, member, i, qual);
// Restore member name.
set_member_name(type.self, i, member_name);
i++;
}
ir.meta[type.self].decoration.decoration_flags = old_flags;
// Treat this variable as flattened from now on.
flattened_structs.insert(var.self);
}
void CompilerGLSL::emit_interface_block(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
// Either make it plain in/out or in/out blocks depending on what shader is doing ...
bool block = ir.meta[type.self].decoration.decoration_flags.get(DecorationBlock);
const char *qual = to_storage_qualifiers_glsl(var);
if (block)
{
// ESSL earlier than 310 and GLSL earlier than 150 did not support
// I/O variables which are struct types.
// To support this, flatten the struct into separate varyings instead.
if ((options.es && options.version < 310) || (!options.es && options.version < 150))
{
// I/O blocks on ES require version 310 with Android Extension Pack extensions, or core version 320.
// On desktop, I/O blocks were introduced with geometry shaders in GL 3.2 (GLSL 150).
emit_flattened_io_block(var, qual);
}
else
{
if (options.es && options.version < 320)
{
// Geometry and tessellation extensions imply this extension.
if (!has_extension("GL_EXT_geometry_shader") && !has_extension("GL_EXT_tessellation_shader"))
require_extension_internal("GL_EXT_shader_io_blocks");
}
// Block names should never alias.
auto block_name = to_name(type.self, false);
// The namespace for I/O blocks is separate from other variables in GLSL.
auto &block_namespace = type.storage == StorageClassInput ? block_input_names : block_output_names;
// Shaders never use the block by interface name, so we don't
// have to track this other than updating name caches.
if (block_name.empty() || block_namespace.find(block_name) != end(block_namespace))
block_name = get_fallback_name(type.self);
else
block_namespace.insert(block_name);
// If for some reason buffer_name is an illegal name, make a final fallback to a workaround name.
// This cannot conflict with anything else, so we're safe now.
if (block_name.empty())
block_name = join("_", get<SPIRType>(var.basetype).self, "_", var.self);
// Instance names cannot alias block names.
resource_names.insert(block_name);
statement(layout_for_variable(var), qual, block_name);
begin_scope();
type.member_name_cache.clear();
uint32_t i = 0;
for (auto &member : type.member_types)
{
add_member_name(type, i);
emit_struct_member(type, member, i);
i++;
}
add_resource_name(var.self);
end_scope_decl(join(to_name(var.self), type_to_array_glsl(type)));
statement("");
}
}
else
{
// ESSL earlier than 310 and GLSL earlier than 150 did not support
// I/O variables which are struct types.
// To support this, flatten the struct into separate varyings instead.
if (type.basetype == SPIRType::Struct &&
((options.es && options.version < 310) || (!options.es && options.version < 150)))
{
emit_flattened_io_block(var, qual);
}
else
{
add_resource_name(var.self);
statement(layout_for_variable(var), to_qualifiers_glsl(var.self),
variable_decl(type, to_name(var.self), var.self), ";");
// If a StorageClassOutput variable has an initializer, we need to initialize it in main().
if (var.storage == StorageClassOutput && var.initializer)
{
auto &entry_func = this->get<SPIRFunction>(ir.default_entry_point);
entry_func.fixup_hooks_in.push_back(
[&]() { statement(to_name(var.self), " = ", to_expression(var.initializer), ";"); });
}
}
}
}
void CompilerGLSL::emit_uniform(const SPIRVariable &var)
{
auto &type = get<SPIRType>(var.basetype);
if (type.basetype == SPIRType::Image && type.image.sampled == 2)
{
if (!options.es && options.version < 420)
require_extension_internal("GL_ARB_shader_image_load_store");
else if (options.es && options.version < 310)
SPIRV_CROSS_THROW("At least ESSL 3.10 required for shader image load store.");
}
add_resource_name(var.self);
statement(layout_for_variable(var), variable_decl(var), ";");
}
string CompilerGLSL::constant_value_macro_name(uint32_t id)
{
return join("SPIRV_CROSS_CONSTANT_ID_", id);
}
void CompilerGLSL::emit_specialization_constant_op(const SPIRConstantOp &constant)
{
auto &type = get<SPIRType>(constant.basetype);
auto name = to_name(constant.self);
statement("const ", variable_decl(type, name), " = ", constant_op_expression(constant), ";");
}
void CompilerGLSL::emit_constant(const SPIRConstant &constant)
{
auto &type = get<SPIRType>(constant.constant_type);
auto name = to_name(constant.self);
SpecializationConstant wg_x, wg_y, wg_z;
uint32_t workgroup_size_id = get_work_group_size_specialization_constants(wg_x, wg_y, wg_z);
// This specialization constant is implicitly declared by emitting layout() in;
if (constant.self == workgroup_size_id)
return;
// These specialization constants are implicitly declared by emitting layout() in;
// In legacy GLSL, we will still need to emit macros for these, so a layout() in; declaration
// later can use macro overrides for work group size.
bool is_workgroup_size_constant = constant.self == wg_x.id || constant.self == wg_y.id || constant.self == wg_z.id;
if (options.vulkan_semantics && is_workgroup_size_constant)
{
// Vulkan GLSL does not need to declare workgroup spec constants explicitly, it is handled in layout().
return;
}
else if (!options.vulkan_semantics && is_workgroup_size_constant &&
!has_decoration(constant.self, DecorationSpecId))
{
// Only bother declaring a workgroup size if it is actually a specialization constant, because we need macros.
return;
}
// Only scalars have constant IDs.
if (has_decoration(constant.self, DecorationSpecId))
{
if (options.vulkan_semantics)
{
statement("layout(constant_id = ", get_decoration(constant.self, DecorationSpecId), ") const ",
variable_decl(type, name), " = ", constant_expression(constant), ";");
}
else
{
const string ¯o_name = constant.specialization_constant_macro_name;
statement("#ifndef ", macro_name);
statement("#define ", macro_name, " ", constant_expression(constant));
statement("#endif");
// For workgroup size constants, only emit the macros.
if (!is_workgroup_size_constant)
statement("const ", variable_decl(type, name), " = ", macro_name, ";");
}
}
else
{
statement("const ", variable_decl(type, name), " = ", constant_expression(constant), ";");
}
}
void CompilerGLSL::emit_entry_point_declarations()
{
}
void CompilerGLSL::replace_illegal_names()
{
// clang-format off
static const unordered_set<string> keywords = {
"abs", "acos", "acosh", "all", "any", "asin", "asinh", "atan", "atanh",
"atomicAdd", "atomicCompSwap", "atomicCounter", "atomicCounterDecrement", "atomicCounterIncrement",
"atomicExchange", "atomicMax", "atomicMin", "atomicOr", "atomicXor",
"bitCount", "bitfieldExtract", "bitfieldInsert", "bitfieldReverse",
"ceil", "cos", "cosh", "cross", "degrees",
"dFdx", "dFdxCoarse", "dFdxFine",
"dFdy", "dFdyCoarse", "dFdyFine",
"distance", "dot", "EmitStreamVertex", "EmitVertex", "EndPrimitive", "EndStreamPrimitive", "equal", "exp", "exp2",
"faceforward", "findLSB", "findMSB", "float16BitsToInt16", "float16BitsToUint16", "floatBitsToInt", "floatBitsToUint", "floor", "fma", "fract",
"frexp", "fwidth", "fwidthCoarse", "fwidthFine",
"greaterThan", "greaterThanEqual", "groupMemoryBarrier",
"imageAtomicAdd", "imageAtomicAnd", "imageAtomicCompSwap", "imageAtomicExchange", "imageAtomicMax", "imageAtomicMin", "imageAtomicOr", "imageAtomicXor",
"imageLoad", "imageSamples", "imageSize", "imageStore", "imulExtended", "int16BitsToFloat16", "intBitsToFloat", "interpolateAtOffset", "interpolateAtCentroid", "interpolateAtSample",
"inverse", "inversesqrt", "isinf", "isnan", "ldexp", "length", "lessThan", "lessThanEqual", "log", "log2",
"matrixCompMult", "max", "memoryBarrier", "memoryBarrierAtomicCounter", "memoryBarrierBuffer", "memoryBarrierImage", "memoryBarrierShared",
"min", "mix", "mod", "modf", "noise", "noise1", "noise2", "noise3", "noise4", "normalize", "not", "notEqual",
"outerProduct", "packDouble2x32", "packHalf2x16", "packInt2x16", "packInt4x16", "packSnorm2x16", "packSnorm4x8",
"packUint2x16", "packUint4x16", "packUnorm2x16", "packUnorm4x8", "pow",
"radians", "reflect", "refract", "round", "roundEven", "sign", "sin", "sinh", "smoothstep", "sqrt", "step",
"tan", "tanh", "texelFetch", "texelFetchOffset", "texture", "textureGather", "textureGatherOffset", "textureGatherOffsets",
"textureGrad", "textureGradOffset", "textureLod", "textureLodOffset", "textureOffset", "textureProj", "textureProjGrad",
"textureProjGradOffset", "textureProjLod", "textureProjLodOffset", "textureProjOffset", "textureQueryLevels", "textureQueryLod", "textureSamples", "textureSize",
"transpose", "trunc", "uaddCarry", "uint16BitsToFloat16", "uintBitsToFloat", "umulExtended", "unpackDouble2x32", "unpackHalf2x16", "unpackInt2x16", "unpackInt4x16",
"unpackSnorm2x16", "unpackSnorm4x8", "unpackUint2x16", "unpackUint4x16", "unpackUnorm2x16", "unpackUnorm4x8", "usubBorrow",
"active", "asm", "atomic_uint", "attribute", "bool", "break", "buffer",
"bvec2", "bvec3", "bvec4", "case", "cast", "centroid", "class", "coherent", "common", "const", "continue", "default", "discard",
"dmat2", "dmat2x2", "dmat2x3", "dmat2x4", "dmat3", "dmat3x2", "dmat3x3", "dmat3x4", "dmat4", "dmat4x2", "dmat4x3", "dmat4x4",
"do", "double", "dvec2", "dvec3", "dvec4", "else", "enum", "extern", "external", "false", "filter", "fixed", "flat", "float",
"for", "fvec2", "fvec3", "fvec4", "goto", "half", "highp", "hvec2", "hvec3", "hvec4", "if", "iimage1D", "iimage1DArray",
"iimage2D", "iimage2DArray", "iimage2DMS", "iimage2DMSArray", "iimage2DRect", "iimage3D", "iimageBuffer", "iimageCube",
"iimageCubeArray", "image1D", "image1DArray", "image2D", "image2DArray", "image2DMS", "image2DMSArray", "image2DRect",
"image3D", "imageBuffer", "imageCube", "imageCubeArray", "in", "inline", "inout", "input", "int", "interface", "invariant",
"isampler1D", "isampler1DArray", "isampler2D", "isampler2DArray", "isampler2DMS", "isampler2DMSArray", "isampler2DRect",
"isampler3D", "isamplerBuffer", "isamplerCube", "isamplerCubeArray", "ivec2", "ivec3", "ivec4", "layout", "long", "lowp",
"mat2", "mat2x2", "mat2x3", "mat2x4", "mat3", "mat3x2", "mat3x3", "mat3x4", "mat4", "mat4x2", "mat4x3", "mat4x4", "mediump",
"namespace", "noinline", "noperspective", "out", "output", "packed", "partition", "patch", "precise", "precision", "public", "readonly",
"resource", "restrict", "return", "sample", "sampler1D", "sampler1DArray", "sampler1DArrayShadow",
"sampler1DShadow", "sampler2D", "sampler2DArray", "sampler2DArrayShadow", "sampler2DMS", "sampler2DMSArray",
"sampler2DRect", "sampler2DRectShadow", "sampler2DShadow", "sampler3D", "sampler3DRect", "samplerBuffer",
"samplerCube", "samplerCubeArray", "samplerCubeArrayShadow", "samplerCubeShadow", "shared", "short", "sizeof", "smooth", "static",
"struct", "subroutine", "superp", "switch", "template", "this", "true", "typedef", "uimage1D", "uimage1DArray", "uimage2D",
"uimage2DArray", "uimage2DMS", "uimage2DMSArray", "uimage2DRect", "uimage3D", "uimageBuffer", "uimageCube",
"uimageCubeArray", "uint", "uniform", "union", "unsigned", "usampler1D", "usampler1DArray", "usampler2D", "usampler2DArray",
"usampler2DMS", "usampler2DMSArray", "usampler2DRect", "usampler3D", "usamplerBuffer", "usamplerCube",
"usamplerCubeArray", "using", "uvec2", "uvec3", "uvec4", "varying", "vec2", "vec3", "vec4", "void", "volatile",
"while", "writeonly",
};
// clang-format on
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, const SPIRVariable &var) {
if (!is_hidden_variable(var))
{
auto &m = ir.meta[var.self].decoration;
if (m.alias.compare(0, 3, "gl_") == 0 || keywords.find(m.alias) != end(keywords))
m.alias = join("_", m.alias);
}
});
}
void CompilerGLSL::replace_fragment_output(SPIRVariable &var)
{
auto &m = ir.meta[var.self].decoration;
uint32_t location = 0;
if (m.decoration_flags.get(DecorationLocation))
location = m.location;
// If our variable is arrayed, we must not emit the array part of this as the SPIR-V will
// do the access chain part of this for us.
auto &type = get<SPIRType>(var.basetype);
if (type.array.empty())
{
// Redirect the write to a specific render target in legacy GLSL.
m.alias = join("gl_FragData[", location, "]");
if (is_legacy_es() && location != 0)
require_extension_internal("GL_EXT_draw_buffers");
}
else if (type.array.size() == 1)
{
// If location is non-zero, we probably have to add an offset.
// This gets really tricky since we'd have to inject an offset in the access chain.
// FIXME: This seems like an extremely odd-ball case, so it's probably fine to leave it like this for now.
m.alias = "gl_FragData";
if (location != 0)
SPIRV_CROSS_THROW("Arrayed output variable used, but location is not 0. "
"This is unimplemented in SPIRV-Cross.");
if (is_legacy_es())
require_extension_internal("GL_EXT_draw_buffers");
}
else
SPIRV_CROSS_THROW("Array-of-array output variable used. This cannot be implemented in legacy GLSL.");
var.compat_builtin = true; // We don't want to declare this variable, but use the name as-is.
}
void CompilerGLSL::replace_fragment_outputs()
{
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) {
auto &type = this->get<SPIRType>(var.basetype);
if (!is_builtin_variable(var) && !var.remapped_variable && type.pointer && var.storage == StorageClassOutput)
replace_fragment_output(var);
});
}
string CompilerGLSL::remap_swizzle(const SPIRType &out_type, uint32_t input_components, const string &expr)
{
if (out_type.vecsize == input_components)
return expr;
else if (input_components == 1 && !backend.can_swizzle_scalar)
return join(type_to_glsl(out_type), "(", expr, ")");
else
{
// FIXME: This will not work with packed expressions.
auto e = enclose_expression(expr) + ".";
// Just clamp the swizzle index if we have more outputs than inputs.
for (uint32_t c = 0; c < out_type.vecsize; c++)
e += index_to_swizzle(min(c, input_components - 1));
if (backend.swizzle_is_function && out_type.vecsize > 1)
e += "()";
remove_duplicate_swizzle(e);
return e;
}
}
void CompilerGLSL::emit_pls()
{
auto &execution = get_entry_point();
if (execution.model != ExecutionModelFragment)
SPIRV_CROSS_THROW("Pixel local storage only supported in fragment shaders.");
if (!options.es)
SPIRV_CROSS_THROW("Pixel local storage only supported in OpenGL ES.");
if (options.version < 300)
SPIRV_CROSS_THROW("Pixel local storage only supported in ESSL 3.0 and above.");
if (!pls_inputs.empty())
{
statement("__pixel_local_inEXT _PLSIn");
begin_scope();
for (auto &input : pls_inputs)
statement(pls_decl(input), ";");
end_scope_decl();
statement("");
}
if (!pls_outputs.empty())
{
statement("__pixel_local_outEXT _PLSOut");
begin_scope();
for (auto &output : pls_outputs)
statement(pls_decl(output), ";");
end_scope_decl();
statement("");
}
}
void CompilerGLSL::fixup_image_load_store_access()
{
ir.for_each_typed_id<SPIRVariable>([&](uint32_t var, const SPIRVariable &) {
auto &vartype = expression_type(var);
if (vartype.basetype == SPIRType::Image)
{
// Older glslangValidator does not emit required qualifiers here.
// Solve this by making the image access as restricted as possible and loosen up if we need to.
// If any no-read/no-write flags are actually set, assume that the compiler knows what it's doing.
auto &flags = ir.meta[var].decoration.decoration_flags;
if (!flags.get(DecorationNonWritable) && !flags.get(DecorationNonReadable))
{
flags.set(DecorationNonWritable);
flags.set(DecorationNonReadable);
}
}
});
}
void CompilerGLSL::emit_declared_builtin_block(StorageClass storage, ExecutionModel model)
{
Bitset emitted_builtins;
Bitset global_builtins;
const SPIRVariable *block_var = nullptr;
bool emitted_block = false;
bool builtin_array = false;
// Need to use declared size in the type.
// These variables might have been declared, but not statically used, so we haven't deduced their size yet.
uint32_t cull_distance_size = 0;
uint32_t clip_distance_size = 0;
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) {
auto &type = this->get<SPIRType>(var.basetype);
bool block = has_decoration(type.self, DecorationBlock);
Bitset builtins;
if (var.storage == storage && block && is_builtin_variable(var))
{
uint32_t index = 0;
for (auto &m : ir.meta[type.self].members)
{
if (m.builtin)
{
builtins.set(m.builtin_type);
if (m.builtin_type == BuiltInCullDistance)
cull_distance_size = this->get<SPIRType>(type.member_types[index]).array.front();
else if (m.builtin_type == BuiltInClipDistance)
clip_distance_size = this->get<SPIRType>(type.member_types[index]).array.front();
}
index++;
}
}
else if (var.storage == storage && !block && is_builtin_variable(var))
{
// While we're at it, collect all declared global builtins (HLSL mostly ...).
auto &m = ir.meta[var.self].decoration;
if (m.builtin)
{
global_builtins.set(m.builtin_type);
if (m.builtin_type == BuiltInCullDistance)
cull_distance_size = type.array.front();
else if (m.builtin_type == BuiltInClipDistance)
clip_distance_size = type.array.front();
}
}
if (builtins.empty())
return;
if (emitted_block)
SPIRV_CROSS_THROW("Cannot use more than one builtin I/O block.");
emitted_builtins = builtins;
emitted_block = true;
builtin_array = !type.array.empty();
block_var = &var;
});
global_builtins =
Bitset(global_builtins.get_lower() & ((1ull << BuiltInPosition) | (1ull << BuiltInPointSize) |
(1ull << BuiltInClipDistance) | (1ull << BuiltInCullDistance)));
// Try to collect all other declared builtins.
if (!emitted_block)
emitted_builtins = global_builtins;
// Can't declare an empty interface block.
if (emitted_builtins.empty())
return;
if (storage == StorageClassOutput)
statement("out gl_PerVertex");
else
statement("in gl_PerVertex");
begin_scope();
if (emitted_builtins.get(BuiltInPosition))
statement("vec4 gl_Position;");
if (emitted_builtins.get(BuiltInPointSize))
statement("float gl_PointSize;");
if (emitted_builtins.get(BuiltInClipDistance))
statement("float gl_ClipDistance[", clip_distance_size, "];");
if (emitted_builtins.get(BuiltInCullDistance))
statement("float gl_CullDistance[", cull_distance_size, "];");
bool tessellation = model == ExecutionModelTessellationEvaluation || model == ExecutionModelTessellationControl;
if (builtin_array)
{
// Make sure the array has a supported name in the code.
if (storage == StorageClassOutput)
set_name(block_var->self, "gl_out");
else if (storage == StorageClassInput)
set_name(block_var->self, "gl_in");
if (model == ExecutionModelTessellationControl && storage == StorageClassOutput)
end_scope_decl(join(to_name(block_var->self), "[", get_entry_point().output_vertices, "]"));
else
end_scope_decl(join(to_name(block_var->self), tessellation ? "[gl_MaxPatchVertices]" : "[]"));
}
else
end_scope_decl();
statement("");
}
void CompilerGLSL::declare_undefined_values()
{
bool emitted = false;
ir.for_each_typed_id<SPIRUndef>([&](uint32_t, const SPIRUndef &undef) {
statement(variable_decl(this->get<SPIRType>(undef.basetype), to_name(undef.self), undef.self), ";");
emitted = true;
});
if (emitted)
statement("");
}
bool CompilerGLSL::variable_is_lut(const SPIRVariable &var) const
{
bool statically_assigned = var.statically_assigned && var.static_expression != 0 && var.remapped_variable;
if (statically_assigned)
{
auto *constant = maybe_get<SPIRConstant>(var.static_expression);
if (constant && constant->is_used_as_lut)
return true;
}
return false;
}
void CompilerGLSL::emit_resources()
{
auto &execution = get_entry_point();
replace_illegal_names();
// Legacy GL uses gl_FragData[], redeclare all fragment outputs
// with builtins.
if (execution.model == ExecutionModelFragment && is_legacy())
replace_fragment_outputs();
// Emit PLS blocks if we have such variables.
if (!pls_inputs.empty() || !pls_outputs.empty())
emit_pls();
// Emit custom gl_PerVertex for SSO compatibility.
if (options.separate_shader_objects && !options.es && execution.model != ExecutionModelFragment)
{
switch (execution.model)
{
case ExecutionModelGeometry:
case ExecutionModelTessellationControl:
case ExecutionModelTessellationEvaluation:
emit_declared_builtin_block(StorageClassInput, execution.model);
emit_declared_builtin_block(StorageClassOutput, execution.model);
break;
case ExecutionModelVertex:
emit_declared_builtin_block(StorageClassOutput, execution.model);
break;
default:
break;
}
}
else
{
// Need to redeclare clip/cull distance with explicit size to use them.
// SPIR-V mandates these builtins have a size declared.
const char *storage = execution.model == ExecutionModelFragment ? "in" : "out";
if (clip_distance_count != 0)
statement(storage, " float gl_ClipDistance[", clip_distance_count, "];");
if (cull_distance_count != 0)
statement(storage, " float gl_CullDistance[", cull_distance_count, "];");
if (clip_distance_count != 0 || cull_distance_count != 0)
statement("");
}
if (position_invariant)
{
statement("invariant gl_Position;");
statement("");
}
bool emitted = false;
// If emitted Vulkan GLSL,
// emit specialization constants as actual floats,
// spec op expressions will redirect to the constant name.
//
for (auto &id_ : ir.ids_for_constant_or_type)
{
auto &id = ir.ids[id_];
if (id.get_type() == TypeConstant)
{
auto &c = id.get<SPIRConstant>();
bool needs_declaration = c.specialization || c.is_used_as_lut;
if (needs_declaration)
{
if (!options.vulkan_semantics && c.specialization)
{
c.specialization_constant_macro_name =
constant_value_macro_name(get_decoration(c.self, DecorationSpecId));
}
emit_constant(c);
emitted = true;
}
}
else if (id.get_type() == TypeConstantOp)
{
emit_specialization_constant_op(id.get<SPIRConstantOp>());
emitted = true;
}
else if (id.get_type() == TypeType)
{
auto &type = id.get<SPIRType>();
if (type.basetype == SPIRType::Struct && type.array.empty() && !type.pointer &&
(!ir.meta[type.self].decoration.decoration_flags.get(DecorationBlock) &&
!ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock)))
{
if (emitted)
statement("");
emitted = false;
emit_struct(type);
}
}
}
if (emitted)
statement("");
// If we needed to declare work group size late, check here.
// If the work group size depends on a specialization constant, we need to declare the layout() block
// after constants (and their macros) have been declared.
if (execution.model == ExecutionModelGLCompute && !options.vulkan_semantics &&
execution.workgroup_size.constant != 0)
{
SpecializationConstant wg_x, wg_y, wg_z;
get_work_group_size_specialization_constants(wg_x, wg_y, wg_z);
if ((wg_x.id != 0) || (wg_y.id != 0) || (wg_z.id != 0))
{
SmallVector<string> inputs;
build_workgroup_size(inputs, wg_x, wg_y, wg_z);
statement("layout(", merge(inputs), ") in;");
statement("");
}
}
emitted = false;
if (ir.addressing_model == AddressingModelPhysicalStorageBuffer64EXT)
{
for (auto type : physical_storage_non_block_pointer_types)
{
emit_buffer_reference_block(get<SPIRType>(type), false);
}
// Output buffer reference blocks.
// Do this in two stages, one with forward declaration,
// and one without. Buffer reference blocks can reference themselves
// to support things like linked lists.
ir.for_each_typed_id<SPIRType>([&](uint32_t, SPIRType &type) {
bool has_block_flags = has_decoration(type.self, DecorationBlock);
if (has_block_flags && type.pointer && type.pointer_depth == 1 && !type_is_array_of_pointers(type) &&
type.storage == StorageClassPhysicalStorageBufferEXT)
{
emit_buffer_reference_block(type, true);
}
});
ir.for_each_typed_id<SPIRType>([&](uint32_t, SPIRType &type) {
bool has_block_flags = has_decoration(type.self, DecorationBlock);
if (has_block_flags && type.pointer && type.pointer_depth == 1 && !type_is_array_of_pointers(type) &&
type.storage == StorageClassPhysicalStorageBufferEXT)
{
emit_buffer_reference_block(type, false);
}
});
}
// Output UBOs and SSBOs
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) {
auto &type = this->get<SPIRType>(var.basetype);
bool is_block_storage = type.storage == StorageClassStorageBuffer || type.storage == StorageClassUniform ||
type.storage == StorageClassShaderRecordBufferNV;
bool has_block_flags = ir.meta[type.self].decoration.decoration_flags.get(DecorationBlock) ||
ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock);
if (var.storage != StorageClassFunction && type.pointer && is_block_storage && !is_hidden_variable(var) &&
has_block_flags)
{
emit_buffer_block(var);
}
});
// Output push constant blocks
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) {
auto &type = this->get<SPIRType>(var.basetype);
if (var.storage != StorageClassFunction && type.pointer && type.storage == StorageClassPushConstant &&
!is_hidden_variable(var))
{
emit_push_constant_block(var);
}
});
bool skip_separate_image_sampler = !combined_image_samplers.empty() || !options.vulkan_semantics;
// Output Uniform Constants (values, samplers, images, etc).
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) {
auto &type = this->get<SPIRType>(var.basetype);
// If we're remapping separate samplers and images, only emit the combined samplers.
if (skip_separate_image_sampler)
{
// Sampler buffers are always used without a sampler, and they will also work in regular GL.
bool sampler_buffer = type.basetype == SPIRType::Image && type.image.dim == DimBuffer;
bool separate_image = type.basetype == SPIRType::Image && type.image.sampled == 1;
bool separate_sampler = type.basetype == SPIRType::Sampler;
if (!sampler_buffer && (separate_image || separate_sampler))
return;
}
if (var.storage != StorageClassFunction && type.pointer &&
(type.storage == StorageClassUniformConstant || type.storage == StorageClassAtomicCounter ||
type.storage == StorageClassRayPayloadNV || type.storage == StorageClassIncomingRayPayloadNV ||
type.storage == StorageClassCallableDataNV || type.storage == StorageClassIncomingCallableDataNV ||
type.storage == StorageClassHitAttributeNV) &&
!is_hidden_variable(var))
{
emit_uniform(var);
emitted = true;
}
});
if (emitted)
statement("");
emitted = false;
// Output in/out interfaces.
ir.for_each_typed_id<SPIRVariable>([&](uint32_t, SPIRVariable &var) {
auto &type = this->get<SPIRType>(var.basetype);
if (var.storage != StorageClassFunction && type.pointer &&
(var.storage == StorageClassInput || var.storage == StorageClassOutput) &&
interface_variable_exists_in_entry_point(var.self) && !is_hidden_variable(var))
{
emit_interface_block(var);
emitted = true;
}
else if (is_builtin_variable(var))
{
// For gl_InstanceIndex emulation on GLES, the API user needs to
// supply this uniform.
if (options.vertex.support_nonzero_base_instance &&
ir.meta[var.self].decoration.builtin_type == BuiltInInstanceIndex && !options.vulkan_semantics)
{
statement("uniform int SPIRV_Cross_BaseInstance;");
emitted = true;
}
}
});
// Global variables.
for (auto global : global_variables)
{
auto &var = get<SPIRVariable>(global);
if (var.storage != StorageClassOutput)
{
if (!variable_is_lut(var))
{
add_resource_name(var.self);
statement(variable_decl(var), ";");
emitted = true;
}
}
}
if (emitted)
statement("");
declare_undefined_values();
}
// Returns a string representation of the ID, usable as a function arg.
// Default is to simply return the expression representation fo the arg ID.
// Subclasses may override to modify the return value.
string CompilerGLSL::to_func_call_arg(uint32_t id)
{
// Make sure that we use the name of the original variable, and not the parameter alias.
uint32_t name_id = id;
auto *var = maybe_get<SPIRVariable>(id);
if (var && var->basevariable)
name_id = var->basevariable;
return to_expression(name_id);
}
void CompilerGLSL::handle_invalid_expression(uint32_t id)
{
// We tried to read an invalidated expression.
// This means we need another pass at compilation, but next time, force temporary variables so that they cannot be invalidated.
forced_temporaries.insert(id);
force_recompile();
}
// Converts the format of the current expression from packed to unpacked,
// by wrapping the expression in a constructor of the appropriate type.
// GLSL does not support packed formats, so simply return the expression.
// Subclasses that do will override
string CompilerGLSL::unpack_expression_type(string expr_str, const SPIRType &, uint32_t)
{
return expr_str;
}
// Sometimes we proactively enclosed an expression where it turns out we might have not needed it after all.
void CompilerGLSL::strip_enclosed_expression(string &expr)
{
if (expr.size() < 2 || expr.front() != '(' || expr.back() != ')')
return;
// Have to make sure that our first and last parens actually enclose everything inside it.
uint32_t paren_count = 0;
for (auto &c : expr)
{
if (c == '(')
paren_count++;
else if (c == ')')
{
paren_count--;
// If we hit 0 and this is not the final char, our first and final parens actually don't
// enclose the expression, and we cannot strip, e.g.: (a + b) * (c + d).
if (paren_count == 0 && &c != &expr.back())
return;
}
}
expr.erase(expr.size() - 1, 1);
expr.erase(begin(expr));
}
string CompilerGLSL::enclose_expression(const string &expr)
{
bool need_parens = false;
// If the expression starts with a unary we need to enclose to deal with cases where we have back-to-back
// unary expressions.
if (!expr.empty())
{
auto c = expr.front();
if (c == '-' || c == '+' || c == '!' || c == '~' || c == '&' || c == '*')
need_parens = true;
}
if (!need_parens)
{
uint32_t paren_count = 0;
for (auto c : expr)
{
if (c == '(' || c == '[')
paren_count++;
else if (c == ')' || c == ']')
{
assert(paren_count);
paren_count--;
}
else if (c == ' ' && paren_count == 0)
{
need_parens = true;
break;
}
}
assert(paren_count == 0);
}
// If this expression contains any spaces which are not enclosed by parentheses,
// we need to enclose it so we can treat the whole string as an expression.
// This happens when two expressions have been part of a binary op earlier.
if (need_parens)
return join('(', expr, ')');
else
return expr;
}
string CompilerGLSL::dereference_expression(const SPIRType &expr_type, const std::string &expr)
{
// If this expression starts with an address-of operator ('&'), then
// just return the part after the operator.
// TODO: Strip parens if unnecessary?
if (expr.front() == '&')
return expr.substr(1);
else if (backend.native_pointers)
return join('*', expr);
else if (expr_type.storage == StorageClassPhysicalStorageBufferEXT && expr_type.basetype != SPIRType::Struct &&
expr_type.pointer_depth == 1)
{
return join(enclose_expression(expr), ".value");
}
else
return expr;
}
string CompilerGLSL::address_of_expression(const std::string &expr)
{
if (expr.size() > 3 && expr[0] == '(' && expr[1] == '*' && expr.back() == ')')
{
// If we have an expression which looks like (*foo), taking the address of it is the same as stripping
// the first two and last characters. We might have to enclose the expression.
// This doesn't work for cases like (*foo + 10),
// but this is an r-value expression which we cannot take the address of anyways.
return enclose_expression(expr.substr(2, expr.size() - 3));
}
else if (expr.front() == '*')
{
// If this expression starts with a dereference operator ('*'), then
// just return the part after the operator.
return expr.substr(1);
}
else
return join('&', enclose_expression(expr));
}
// Just like to_expression except that we enclose the expression inside parentheses if needed.
string CompilerGLSL::to_enclosed_expression(uint32_t id, bool register_expression_read)
{
return enclose_expression(to_expression(id, register_expression_read));
}
string CompilerGLSL::to_unpacked_expression(uint32_t id, bool register_expression_read)
{
// If we need to transpose, it will also take care of unpacking rules.
auto *e = maybe_get<SPIRExpression>(id);
bool need_transpose = e && e->need_transpose;
if (!need_transpose && has_extended_decoration(id, SPIRVCrossDecorationPacked))
return unpack_expression_type(to_expression(id, register_expression_read), expression_type(id),
get_extended_decoration(id, SPIRVCrossDecorationPackedType));
else
return to_expression(id, register_expression_read);
}
string CompilerGLSL::to_enclosed_unpacked_expression(uint32_t id, bool register_expression_read)
{
// If we need to transpose, it will also take care of unpacking rules.
auto *e = maybe_get<SPIRExpression>(id);
bool need_transpose = e && e->need_transpose;
if (!need_transpose && has_extended_decoration(id, SPIRVCrossDecorationPacked))
return unpack_expression_type(to_expression(id, register_expression_read), expression_type(id),
get_extended_decoration(id, SPIRVCrossDecorationPackedType));
else
return to_enclosed_expression(id, register_expression_read);
}
string CompilerGLSL::to_dereferenced_expression(uint32_t id, bool register_expression_read)
{
auto &type = expression_type(id);
if (type.pointer && should_dereference(id))
return dereference_expression(type, to_enclosed_expression(id, register_expression_read));
else
return to_expression(id, register_expression_read);
}
string CompilerGLSL::to_pointer_expression(uint32_t id, bool register_expression_read)
{
auto &type = expression_type(id);
if (type.pointer && expression_is_lvalue(id) && !should_dereference(id))
return address_of_expression(to_enclosed_expression(id, register_expression_read));
else
return to_unpacked_expression(id, register_expression_read);
}
string CompilerGLSL::to_enclosed_pointer_expression(uint32_t id, bool register_expression_read)
{
auto &type = expression_type(id);
if (type.pointer && expression_is_lvalue(id) && !should_dereference(id))
return address_of_expression(to_enclosed_expression(id, register_expression_read));
else
return to_enclosed_unpacked_expression(id, register_expression_read);
}
string CompilerGLSL::to_extract_component_expression(uint32_t id, uint32_t index)
{
auto expr = to_enclosed_expression(id);
if (has_extended_decoration(id, SPIRVCrossDecorationPacked))
return join(expr, "[", index, "]");
else
return join(expr, ".", index_to_swizzle(index));
}
string CompilerGLSL::to_rerolled_array_expression(const string &base_expr, const SPIRType &type)
{
uint32_t size = to_array_size_literal(type);
auto &parent = get<SPIRType>(type.parent_type);
string expr = "{ ";
for (uint32_t i = 0; i < size; i++)
{
auto subexpr = join(base_expr, "[", convert_to_string(i), "]");
if (parent.array.empty())
expr += subexpr;
else
expr += to_rerolled_array_expression(subexpr, parent);
if (i + 1 < size)
expr += ", ";
}
expr += " }";
return expr;
}
string CompilerGLSL::to_composite_constructor_expression(uint32_t id)
{
auto &type = expression_type(id);
if (!backend.array_is_value_type && !type.array.empty())
{
// For this case, we need to "re-roll" an array initializer from a temporary.
// We cannot simply pass the array directly, since it decays to a pointer and it cannot
// participate in a struct initializer. E.g.
// float arr[2] = { 1.0, 2.0 };
// Foo foo = { arr }; must be transformed to
// Foo foo = { { arr[0], arr[1] } };
// The array sizes cannot be deduced from specialization constants since we cannot use any loops.
// We're only triggering one read of the array expression, but this is fine since arrays have to be declared
// as temporaries anyways.
return to_rerolled_array_expression(to_enclosed_expression(id), type);
}
else
return to_expression(id);
}
string CompilerGLSL::to_expression(uint32_t id, bool register_expression_read)
{
auto itr = invalid_expressions.find(id);
if (itr != end(invalid_expressions))
handle_invalid_expression(id);
if (ir.ids[id].get_type() == TypeExpression)
{
// We might have a more complex chain of dependencies.
// A possible scenario is that we
//
// %1 = OpLoad
// %2 = OpDoSomething %1 %1. here %2 will have a dependency on %1.
// %3 = OpDoSomethingAgain %2 %2. Here %3 will lose the link to %1 since we don't propagate the dependencies like that.
// OpStore %1 %foo // Here we can invalidate %1, and hence all expressions which depend on %1. Only %2 will know since it's part of invalid_expressions.
// %4 = OpDoSomethingAnotherTime %3 %3 // If we forward all expressions we will see %1 expression after store, not before.
//
// However, we can propagate up a list of depended expressions when we used %2, so we can check if %2 is invalid when reading %3 after the store,
// and see that we should not forward reads of the original variable.
auto &expr = get<SPIRExpression>(id);
for (uint32_t dep : expr.expression_dependencies)
if (invalid_expressions.find(dep) != end(invalid_expressions))
handle_invalid_expression(dep);
}
if (register_expression_read)
track_expression_read(id);
switch (ir.ids[id].get_type())
{
case TypeExpression:
{
auto &e = get<SPIRExpression>(id);
if (e.base_expression)
return to_enclosed_expression(e.base_expression) + e.expression;
else if (e.need_transpose)
{
bool is_packed = has_extended_decoration(id, SPIRVCrossDecorationPacked);
return convert_row_major_matrix(e.expression, get<SPIRType>(e.expression_type), is_packed);
}
else
{
if (is_forcing_recompilation())
{
// During first compilation phase, certain expression patterns can trigger exponential growth of memory.
// Avoid this by returning dummy expressions during this phase.
// Do not use empty expressions here, because those are sentinels for other cases.
return "_";
}
else
return e.expression;
}
}
case TypeConstant:
{
auto &c = get<SPIRConstant>(id);
auto &type = get<SPIRType>(c.constant_type);
// WorkGroupSize may be a constant.
auto &dec = ir.meta[c.self].decoration;
if (dec.builtin)
return builtin_to_glsl(dec.builtin_type, StorageClassGeneric);
else if (c.specialization)
return to_name(id);
else if (c.is_used_as_lut)
return to_name(id);
else if (type.basetype == SPIRType::Struct && !backend.can_declare_struct_inline)
return to_name(id);
else if (!type.array.empty() && !backend.can_declare_arrays_inline)
return to_name(id);
else
return constant_expression(c);
}
case TypeConstantOp:
return to_name(id);
case TypeVariable:
{
auto &var = get<SPIRVariable>(id);
// If we try to use a loop variable before the loop header, we have to redirect it to the static expression,
// the variable has not been declared yet.
if (var.statically_assigned || (var.loop_variable && !var.loop_variable_enable))
return to_expression(var.static_expression);
else if (var.deferred_declaration)
{
var.deferred_declaration = false;
return variable_decl(var);
}
else if (flattened_structs.count(id))
{
return load_flattened_struct(var);
}
else
{
auto &dec = ir.meta[var.self].decoration;
if (dec.builtin)
return builtin_to_glsl(dec.builtin_type, var.storage);
else
return to_name(id);
}
}
case TypeCombinedImageSampler:
// This type should never be taken the expression of directly.
// The intention is that texture sampling functions will extract the image and samplers
// separately and take their expressions as needed.
// GLSL does not use this type because OpSampledImage immediately creates a combined image sampler
// expression ala sampler2D(texture, sampler).
SPIRV_CROSS_THROW("Combined image samplers have no default expression representation.");
case TypeAccessChain:
// We cannot express this type. They only have meaning in other OpAccessChains, OpStore or OpLoad.
SPIRV_CROSS_THROW("Access chains have no default expression representation.");
default:
return to_name(id);
}
}
string CompilerGLSL::constant_op_expression(const SPIRConstantOp &cop)
{
auto &type = get<SPIRType>(cop.basetype);
bool binary = false;
bool unary = false;
string op;
if (is_legacy() && is_unsigned_opcode(cop.opcode))
SPIRV_CROSS_THROW("Unsigned integers are not supported on legacy targets.");
// TODO: Find a clean way to reuse emit_instruction.
switch (cop.opcode)
{
case OpSConvert:
case OpUConvert:
case OpFConvert:
op = type_to_glsl_constructor(type);
break;
#define GLSL_BOP(opname, x) \
case Op##opname: \
binary = true; \
op = x; \
break
#define GLSL_UOP(opname, x) \
case Op##opname: \
unary = true; \
op = x; \
break
GLSL_UOP(SNegate, "-");
GLSL_UOP(Not, "~");
GLSL_BOP(IAdd, "+");
GLSL_BOP(ISub, "-");
GLSL_BOP(IMul, "*");
GLSL_BOP(SDiv, "/");
GLSL_BOP(UDiv, "/");
GLSL_BOP(UMod, "%");
GLSL_BOP(SMod, "%");
GLSL_BOP(ShiftRightLogical, ">>");
GLSL_BOP(ShiftRightArithmetic, ">>");
GLSL_BOP(ShiftLeftLogical, "<<");
GLSL_BOP(BitwiseOr, "|");
GLSL_BOP(BitwiseXor, "^");
GLSL_BOP(BitwiseAnd, "&");
GLSL_BOP(LogicalOr, "||");
GLSL_BOP(LogicalAnd, "&&");
GLSL_UOP(LogicalNot, "!");
GLSL_BOP(LogicalEqual, "==");
GLSL_BOP(LogicalNotEqual, "!=");
GLSL_BOP(IEqual, "==");
GLSL_BOP(INotEqual, "!=");
GLSL_BOP(ULessThan, "<");
GLSL_BOP(SLessThan, "<");
GLSL_BOP(ULessThanEqual, "<=");
GLSL_BOP(SLessThanEqual, "<=");
GLSL_BOP(UGreaterThan, ">");
GLSL_BOP(SGreaterThan, ">");
GLSL_BOP(UGreaterThanEqual, ">=");
GLSL_BOP(SGreaterThanEqual, ">=");
case OpSelect:
{
if (cop.arguments.size() < 3)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
// This one is pretty annoying. It's triggered from
// uint(bool), int(bool) from spec constants.
// In order to preserve its compile-time constness in Vulkan GLSL,
// we need to reduce the OpSelect expression back to this simplified model.
// If we cannot, fail.
if (to_trivial_mix_op(type, op, cop.arguments[2], cop.arguments[1], cop.arguments[0]))
{
// Implement as a simple cast down below.
}
else
{
// Implement a ternary and pray the compiler understands it :)
return to_ternary_expression(type, cop.arguments[0], cop.arguments[1], cop.arguments[2]);
}
break;
}
case OpVectorShuffle:
{
string expr = type_to_glsl_constructor(type);
expr += "(";
uint32_t left_components = expression_type(cop.arguments[0]).vecsize;
string left_arg = to_enclosed_expression(cop.arguments[0]);
string right_arg = to_enclosed_expression(cop.arguments[1]);
for (uint32_t i = 2; i < uint32_t(cop.arguments.size()); i++)
{
uint32_t index = cop.arguments[i];
if (index >= left_components)
expr += right_arg + "." + "xyzw"[index - left_components];
else
expr += left_arg + "." + "xyzw"[index];
if (i + 1 < uint32_t(cop.arguments.size()))
expr += ", ";
}
expr += ")";
return expr;
}
case OpCompositeExtract:
{
auto expr = access_chain_internal(cop.arguments[0], &cop.arguments[1], uint32_t(cop.arguments.size() - 1),
ACCESS_CHAIN_INDEX_IS_LITERAL_BIT, nullptr);
return expr;
}
case OpCompositeInsert:
SPIRV_CROSS_THROW("OpCompositeInsert spec constant op is not supported.");
default:
// Some opcodes are unimplemented here, these are currently not possible to test from glslang.
SPIRV_CROSS_THROW("Unimplemented spec constant op.");
}
uint32_t bit_width = 0;
if (unary || binary || cop.opcode == OpSConvert || cop.opcode == OpUConvert)
bit_width = expression_type(cop.arguments[0]).width;
SPIRType::BaseType input_type;
bool skip_cast_if_equal_type = opcode_is_sign_invariant(cop.opcode);
switch (cop.opcode)
{
case OpIEqual:
case OpINotEqual:
input_type = to_signed_basetype(bit_width);
break;
case OpSLessThan:
case OpSLessThanEqual:
case OpSGreaterThan:
case OpSGreaterThanEqual:
case OpSMod:
case OpSDiv:
case OpShiftRightArithmetic:
case OpSConvert:
case OpSNegate:
input_type = to_signed_basetype(bit_width);
break;
case OpULessThan:
case OpULessThanEqual:
case OpUGreaterThan:
case OpUGreaterThanEqual:
case OpUMod:
case OpUDiv:
case OpShiftRightLogical:
case OpUConvert:
input_type = to_unsigned_basetype(bit_width);
break;
default:
input_type = type.basetype;
break;
}
#undef GLSL_BOP
#undef GLSL_UOP
if (binary)
{
if (cop.arguments.size() < 2)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
string cast_op0;
string cast_op1;
auto expected_type = binary_op_bitcast_helper(cast_op0, cast_op1, input_type, cop.arguments[0],
cop.arguments[1], skip_cast_if_equal_type);
if (type.basetype != input_type && type.basetype != SPIRType::Boolean)
{
expected_type.basetype = input_type;
auto expr = bitcast_glsl_op(type, expected_type);
expr += '(';
expr += join(cast_op0, " ", op, " ", cast_op1);
expr += ')';
return expr;
}
else
return join("(", cast_op0, " ", op, " ", cast_op1, ")");
}
else if (unary)
{
if (cop.arguments.size() < 1)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
// Auto-bitcast to result type as needed.
// Works around various casting scenarios in glslang as there is no OpBitcast for specialization constants.
return join("(", op, bitcast_glsl(type, cop.arguments[0]), ")");
}
else if (cop.opcode == OpSConvert || cop.opcode == OpUConvert)
{
if (cop.arguments.size() < 1)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
auto &arg_type = expression_type(cop.arguments[0]);
if (arg_type.width < type.width && input_type != arg_type.basetype)
{
auto expected = arg_type;
expected.basetype = input_type;
return join(op, "(", bitcast_glsl(expected, cop.arguments[0]), ")");
}
else
return join(op, "(", to_expression(cop.arguments[0]), ")");
}
else
{
if (cop.arguments.size() < 1)
SPIRV_CROSS_THROW("Not enough arguments to OpSpecConstantOp.");
return join(op, "(", to_expression(cop.arguments[0]), ")");
}
}
string CompilerGLSL::constant_expression(const SPIRConstant &c)
{
auto &type = get<SPIRType>(c.constant_type);
if (type.pointer)
{
return backend.null_pointer_literal;
}
else if (!c.subconstants.empty())
{
// Handles Arrays and structures.
string res;
if (backend.use_initializer_list && backend.use_typed_initializer_list && type.basetype == SPIRType::Struct &&
type.array.empty())
{
res = type_to_glsl_constructor(type) + "{ ";
}
else if (backend.use_initializer_list)
{
res = "{ ";
}
else
{
res = type_to_glsl_constructor(type) + "(";
}
for (auto &elem : c.subconstants)
{
auto &subc = get<SPIRConstant>(elem);
if (subc.specialization)
res += to_name(elem);
else
res += constant_expression(subc);
if (&elem != &c.subconstants.back())
res += ", ";
}
res += backend.use_initializer_list ? " }" : ")";
return res;
}
else if (c.columns() == 1)
{
return constant_expression_vector(c, 0);
}
else
{
string res = type_to_glsl(get<SPIRType>(c.constant_type)) + "(";
for (uint32_t col = 0; col < c.columns(); col++)
{
if (c.specialization_constant_id(col) != 0)
res += to_name(c.specialization_constant_id(col));
else
res += constant_expression_vector(c, col);
if (col + 1 < c.columns())
res += ", ";
}
res += ")";
return res;
}
}
#ifdef _MSC_VER
// sprintf warning.
// We cannot rely on snprintf existing because, ..., MSVC.
#pragma warning(push)
#pragma warning(disable : 4996)
#endif
string CompilerGLSL::convert_half_to_string(const SPIRConstant &c, uint32_t col, uint32_t row)
{
string res;
float float_value = c.scalar_f16(col, row);
// There is no literal "hf" in GL_NV_gpu_shader5, so to avoid lots
// of complicated workarounds, just value-cast to the half type always.
if (std::isnan(float_value) || std::isinf(float_value))
{
SPIRType type;
type.basetype = SPIRType::Half;
type.vecsize = 1;
type.columns = 1;
if (float_value == numeric_limits<float>::infinity())
res = join(type_to_glsl(type), "(1.0 / 0.0)");
else if (float_value == -numeric_limits<float>::infinity())
res = join(type_to_glsl(type), "(-1.0 / 0.0)");
else if (std::isnan(float_value))
res = join(type_to_glsl(type), "(0.0 / 0.0)");
else
SPIRV_CROSS_THROW("Cannot represent non-finite floating point constant.");
}
else
{
SPIRType type;
type.basetype = SPIRType::Half;
type.vecsize = 1;
type.columns = 1;
res = join(type_to_glsl(type), "(", convert_to_string(float_value, current_locale_radix_character), ")");
}
return res;
}
string CompilerGLSL::convert_float_to_string(const SPIRConstant &c, uint32_t col, uint32_t row)
{
string res;
float float_value = c.scalar_f32(col, row);
if (std::isnan(float_value) || std::isinf(float_value))
{
// Use special representation.
if (!is_legacy())
{
SPIRType out_type;
SPIRType in_type;
out_type.basetype = SPIRType::Float;
in_type.basetype = SPIRType::UInt;
out_type.vecsize = 1;
in_type.vecsize = 1;
out_type.width = 32;
in_type.width = 32;
char print_buffer[32];
sprintf(print_buffer, "0x%xu", c.scalar(col, row));
res = join(bitcast_glsl_op(out_type, in_type), "(", print_buffer, ")");
}
else
{
if (float_value == numeric_limits<float>::infinity())
{
if (backend.float_literal_suffix)
res = "(1.0f / 0.0f)";
else
res = "(1.0 / 0.0)";
}
else if (float_value == -numeric_limits<float>::infinity())
{
if (backend.float_literal_suffix)
res = "(-1.0f / 0.0f)";
else
res = "(-1.0 / 0.0)";
}
else if (std::isnan(float_value))
{
if (backend.float_literal_suffix)
res = "(0.0f / 0.0f)";
else
res = "(0.0 / 0.0)";
}
else
SPIRV_CROSS_THROW("Cannot represent non-finite floating point constant.");
}
}
else
{
res = convert_to_string(float_value, current_locale_radix_character);
if (backend.float_literal_suffix)
res += "f";
}
return res;
}
std::string CompilerGLSL::convert_double_to_string(const SPIRConstant &c, uint32_t col, uint32_t row)
{
string res;
double double_value = c.scalar_f64(col, row);
if (std::isnan(double_value) || std::isinf(double_value))
{
// Use special representation.
if (!is_legacy())
{
SPIRType out_type;
SPIRType in_type;
out_type.basetype = SPIRType::Double;
in_type.basetype = SPIRType::UInt64;
out_type.vecsize = 1;
in_type.vecsize = 1;
out_type.width = 64;
in_type.width = 64;
uint64_t u64_value = c.scalar_u64(col, row);
if (options.es)
SPIRV_CROSS_THROW("64-bit integers/float not supported in ES profile.");
require_extension_internal("GL_ARB_gpu_shader_int64");
char print_buffer[64];
sprintf(print_buffer, "0x%llx%s", static_cast<unsigned long long>(u64_value),
backend.long_long_literal_suffix ? "ull" : "ul");
res = join(bitcast_glsl_op(out_type, in_type), "(", print_buffer, ")");
}
else
{
if (options.es)
SPIRV_CROSS_THROW("FP64 not supported in ES profile.");
if (options.version < 400)
require_extension_internal("GL_ARB_gpu_shader_fp64");
if (double_value == numeric_limits<double>::infinity())
{
if (backend.double_literal_suffix)
res = "(1.0lf / 0.0lf)";
else
res = "(1.0 / 0.0)";
}
else if (double_value == -numeric_limits<double>::infinity())
{
if (backend.double_literal_suffix)
res = "(-1.0lf / 0.0lf)";
else
res = "(-1.0 / 0.0)";
}
else if (std::isnan(double_value))
{
if (backend.double_literal_suffix)
res = "(0.0lf / 0.0lf)";
else
res = "(0.0 / 0.0)";
}
else
SPIRV_CROSS_THROW("Cannot represent non-finite floating point constant.");
}
}
else
{
res = convert_to_string(double_value, current_locale_radix_character);
if (backend.double_literal_suffix)
res += "lf";
}
return res;
}
#ifdef _MSC_VER
#pragma warning(pop)
#endif
string CompilerGLSL::constant_expression_vector(const SPIRConstant &c, uint32_t vector)
{
auto type = get<SPIRType>(c.constant_type);
type.columns = 1;
auto scalar_type = type;
scalar_type.vecsize = 1;
string res;
bool splat = backend.use_constructor_splatting && c.vector_size() > 1;
bool swizzle_splat = backend.can_swizzle_scalar && c.vector_size() > 1;
if (!type_is_floating_point(type))
{
// Cannot swizzle literal integers as a special case.
swizzle_splat = false;
}
if (splat || swizzle_splat)
{
// Cannot use constant splatting if we have specialization constants somewhere in the vector.
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.specialization_constant_id(vector, i) != 0)
{
splat = false;
swizzle_splat = false;
break;
}
}
}
if (splat || swizzle_splat)
{
if (type.width == 64)
{
uint64_t ident = c.scalar_u64(vector, 0);
for (uint32_t i = 1; i < c.vector_size(); i++)
{
if (ident != c.scalar_u64(vector, i))
{
splat = false;
swizzle_splat = false;
break;
}
}
}
else
{
uint32_t ident = c.scalar(vector, 0);
for (uint32_t i = 1; i < c.vector_size(); i++)
{
if (ident != c.scalar(vector, i))
{
splat = false;
swizzle_splat = false;
}
}
}
}
if (c.vector_size() > 1 && !swizzle_splat)
res += type_to_glsl(type) + "(";
switch (type.basetype)
{
case SPIRType::Half:
if (splat || swizzle_splat)
{
res += convert_half_to_string(c, vector, 0);
if (swizzle_splat)
res = remap_swizzle(get<SPIRType>(c.constant_type), 1, res);
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
res += convert_half_to_string(c, vector, i);
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Float:
if (splat || swizzle_splat)
{
res += convert_float_to_string(c, vector, 0);
if (swizzle_splat)
res = remap_swizzle(get<SPIRType>(c.constant_type), 1, res);
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
res += convert_float_to_string(c, vector, i);
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Double:
if (splat || swizzle_splat)
{
res += convert_double_to_string(c, vector, 0);
if (swizzle_splat)
res = remap_swizzle(get<SPIRType>(c.constant_type), 1, res);
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
res += convert_double_to_string(c, vector, i);
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Int64:
if (splat)
{
res += convert_to_string(c.scalar_i64(vector, 0));
if (backend.long_long_literal_suffix)
res += "ll";
else
res += "l";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += convert_to_string(c.scalar_i64(vector, i));
if (backend.long_long_literal_suffix)
res += "ll";
else
res += "l";
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::UInt64:
if (splat)
{
res += convert_to_string(c.scalar_u64(vector, 0));
if (backend.long_long_literal_suffix)
res += "ull";
else
res += "ul";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += convert_to_string(c.scalar_u64(vector, i));
if (backend.long_long_literal_suffix)
res += "ull";
else
res += "ul";
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::UInt:
if (splat)
{
res += convert_to_string(c.scalar(vector, 0));
if (is_legacy())
{
// Fake unsigned constant literals with signed ones if possible.
// Things like array sizes, etc, tend to be unsigned even though they could just as easily be signed.
if (c.scalar_i32(vector, 0) < 0)
SPIRV_CROSS_THROW("Tried to convert uint literal into int, but this made the literal negative.");
}
else if (backend.uint32_t_literal_suffix)
res += "u";
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += convert_to_string(c.scalar(vector, i));
if (is_legacy())
{
// Fake unsigned constant literals with signed ones if possible.
// Things like array sizes, etc, tend to be unsigned even though they could just as easily be signed.
if (c.scalar_i32(vector, i) < 0)
SPIRV_CROSS_THROW(
"Tried to convert uint literal into int, but this made the literal negative.");
}
else if (backend.uint32_t_literal_suffix)
res += "u";
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Int:
if (splat)
res += convert_to_string(c.scalar_i32(vector, 0));
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
res += convert_to_string(c.scalar_i32(vector, i));
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::UShort:
if (splat)
{
res += convert_to_string(c.scalar(vector, 0));
if (is_legacy())
{
// Fake unsigned constant literals with signed ones if possible.
// Things like array sizes, etc, tend to be unsigned even though they could just as easily be signed.
if (c.scalar_i16(vector, 0) < 0)
SPIRV_CROSS_THROW("Tried to convert uint literal into int, but this made the literal negative.");
}
else
res += backend.uint16_t_literal_suffix;
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += convert_to_string(c.scalar(vector, i));
if (is_legacy())
{
// Fake unsigned constant literals with signed ones if possible.
// Things like array sizes, etc, tend to be unsigned even though they could just as easily be signed.
if (c.scalar_i16(vector, i) < 0)
SPIRV_CROSS_THROW(
"Tried to convert uint literal into int, but this made the literal negative.");
}
else
res += backend.uint16_t_literal_suffix;
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Short:
if (splat)
{
res += convert_to_string(c.scalar_i16(vector, 0));
res += backend.int16_t_literal_suffix;
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += convert_to_string(c.scalar_i16(vector, i));
res += backend.int16_t_literal_suffix;
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::UByte:
if (splat)
{
res += convert_to_string(c.scalar_u8(vector, 0));
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += type_to_glsl(scalar_type);
res += "(";
res += convert_to_string(c.scalar_u8(vector, i));
res += ")";
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::SByte:
if (splat)
{
res += convert_to_string(c.scalar_i8(vector, 0));
}
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
{
res += type_to_glsl(scalar_type);
res += "(";
res += convert_to_string(c.scalar_i8(vector, i));
res += ")";
}
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
case SPIRType::Boolean:
if (splat)
res += c.scalar(vector, 0) ? "true" : "false";
else
{
for (uint32_t i = 0; i < c.vector_size(); i++)
{
if (c.vector_size() > 1 && c.specialization_constant_id(vector, i) != 0)
res += to_name(c.specialization_constant_id(vector, i));
else
res += c.scalar(vector, i) ? "true" : "false";
if (i + 1 < c.vector_size())
res += ", ";
}
}
break;
default:
SPIRV_CROSS_THROW("Invalid constant expression basetype.");
}
if (c.vector_size() > 1 && !swizzle_splat)
res += ")";
return res;
}
SPIRExpression &CompilerGLSL::emit_uninitialized_temporary_expression(uint32_t type, uint32_t id)
{
forced_temporaries.insert(id);
emit_uninitialized_temporary(type, id);
return set<SPIRExpression>(id, to_name(id), type, true);
}
void CompilerGLSL::emit_uninitialized_temporary(uint32_t result_type, uint32_t result_id)
{
// If we're declaring temporaries inside continue blocks,
// we must declare the temporary in the loop header so that the continue block can avoid declaring new variables.
if (current_continue_block && !hoisted_temporaries.count(result_id))
{
auto &header = get<SPIRBlock>(current_continue_block->loop_dominator);
if (find_if(begin(header.declare_temporary), end(header.declare_temporary),
[result_type, result_id](const pair<uint32_t, uint32_t> &tmp) {
return tmp.first == result_type && tmp.second == result_id;
}) == end(header.declare_temporary))
{
header.declare_temporary.emplace_back(result_type, result_id);
hoisted_temporaries.insert(result_id);
force_recompile();
}
}
else if (hoisted_temporaries.count(result_id) == 0)
{
auto &type = get<SPIRType>(result_type);
auto &flags = ir.meta[result_id].decoration.decoration_flags;
// The result_id has not been made into an expression yet, so use flags interface.
add_local_variable_name(result_id);
statement(flags_to_qualifiers_glsl(type, flags), variable_decl(type, to_name(result_id)), ";");
}
}
string CompilerGLSL::declare_temporary(uint32_t result_type, uint32_t result_id)
{
auto &type = get<SPIRType>(result_type);
auto &flags = ir.meta[result_id].decoration.decoration_flags;
// If we're declaring temporaries inside continue blocks,
// we must declare the temporary in the loop header so that the continue block can avoid declaring new variables.
if (current_continue_block && !hoisted_temporaries.count(result_id))
{
auto &header = get<SPIRBlock>(current_continue_block->loop_dominator);
if (find_if(begin(header.declare_temporary), end(header.declare_temporary),
[result_type, result_id](const pair<uint32_t, uint32_t> &tmp) {
return tmp.first == result_type && tmp.second == result_id;
}) == end(header.declare_temporary))
{
header.declare_temporary.emplace_back(result_type, result_id);
hoisted_temporaries.insert(result_id);
force_recompile();
}
return join(to_name(result_id), " = ");
}
else if (hoisted_temporaries.count(result_id))
{
// The temporary has already been declared earlier, so just "declare" the temporary by writing to it.
return join(to_name(result_id), " = ");
}
else
{
// The result_id has not been made into an expression yet, so use flags interface.
add_local_variable_name(result_id);
return join(flags_to_qualifiers_glsl(type, flags), variable_decl(type, to_name(result_id)), " = ");
}
}
bool CompilerGLSL::expression_is_forwarded(uint32_t id)
{
return forwarded_temporaries.find(id) != end(forwarded_temporaries);
}
SPIRExpression &CompilerGLSL::emit_op(uint32_t result_type, uint32_t result_id, const string &rhs, bool forwarding,
bool suppress_usage_tracking)
{
if (forwarding && (forced_temporaries.find(result_id) == end(forced_temporaries)))
{
// Just forward it without temporary.
// If the forward is trivial, we do not force flushing to temporary for this expression.
if (!suppress_usage_tracking)
forwarded_temporaries.insert(result_id);
return set<SPIRExpression>(result_id, rhs, result_type, true);
}
else
{
// If expression isn't immutable, bind it to a temporary and make the new temporary immutable (they always are).
statement(declare_temporary(result_type, result_id), rhs, ";");
return set<SPIRExpression>(result_id, to_name(result_id), result_type, true);
}
}
void CompilerGLSL::emit_unary_op(uint32_t result_type, uint32_t result_id, uint32_t op0, const char *op)
{
bool forward = should_forward(op0);
emit_op(result_type, result_id, join(op, to_enclosed_unpacked_expression(op0)), forward);
inherit_expression_dependencies(result_id, op0);
}
void CompilerGLSL::emit_binary_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1, const char *op)
{
bool forward = should_forward(op0) && should_forward(op1);
emit_op(result_type, result_id,
join(to_enclosed_unpacked_expression(op0), " ", op, " ", to_enclosed_unpacked_expression(op1)), forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
void CompilerGLSL::emit_unrolled_unary_op(uint32_t result_type, uint32_t result_id, uint32_t operand, const char *op)
{
auto &type = get<SPIRType>(result_type);
auto expr = type_to_glsl_constructor(type);
expr += '(';
for (uint32_t i = 0; i < type.vecsize; i++)
{
// Make sure to call to_expression multiple times to ensure
// that these expressions are properly flushed to temporaries if needed.
expr += op;
expr += to_extract_component_expression(operand, i);
if (i + 1 < type.vecsize)
expr += ", ";
}
expr += ')';
emit_op(result_type, result_id, expr, should_forward(operand));
inherit_expression_dependencies(result_id, operand);
}
void CompilerGLSL::emit_unrolled_binary_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op)
{
auto &type = get<SPIRType>(result_type);
auto expr = type_to_glsl_constructor(type);
expr += '(';
for (uint32_t i = 0; i < type.vecsize; i++)
{
// Make sure to call to_expression multiple times to ensure
// that these expressions are properly flushed to temporaries if needed.
expr += to_extract_component_expression(op0, i);
expr += ' ';
expr += op;
expr += ' ';
expr += to_extract_component_expression(op1, i);
if (i + 1 < type.vecsize)
expr += ", ";
}
expr += ')';
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1));
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
SPIRType CompilerGLSL::binary_op_bitcast_helper(string &cast_op0, string &cast_op1, SPIRType::BaseType &input_type,
uint32_t op0, uint32_t op1, bool skip_cast_if_equal_type)
{
auto &type0 = expression_type(op0);
auto &type1 = expression_type(op1);
// We have to bitcast if our inputs are of different type, or if our types are not equal to expected inputs.
// For some functions like OpIEqual and INotEqual, we don't care if inputs are of different types than expected
// since equality test is exactly the same.
bool cast = (type0.basetype != type1.basetype) || (!skip_cast_if_equal_type && type0.basetype != input_type);
// Create a fake type so we can bitcast to it.
// We only deal with regular arithmetic types here like int, uints and so on.
SPIRType expected_type;
expected_type.basetype = input_type;
expected_type.vecsize = type0.vecsize;
expected_type.columns = type0.columns;
expected_type.width = type0.width;
if (cast)
{
cast_op0 = bitcast_glsl(expected_type, op0);
cast_op1 = bitcast_glsl(expected_type, op1);
}
else
{
// If we don't cast, our actual input type is that of the first (or second) argument.
cast_op0 = to_enclosed_unpacked_expression(op0);
cast_op1 = to_enclosed_unpacked_expression(op1);
input_type = type0.basetype;
}
return expected_type;
}
void CompilerGLSL::emit_binary_op_cast(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op, SPIRType::BaseType input_type, bool skip_cast_if_equal_type)
{
string cast_op0, cast_op1;
auto expected_type = binary_op_bitcast_helper(cast_op0, cast_op1, input_type, op0, op1, skip_cast_if_equal_type);
auto &out_type = get<SPIRType>(result_type);
// We might have casted away from the result type, so bitcast again.
// For example, arithmetic right shift with uint inputs.
// Special case boolean outputs since relational opcodes output booleans instead of int/uint.
string expr;
if (out_type.basetype != input_type && out_type.basetype != SPIRType::Boolean)
{
expected_type.basetype = input_type;
expr = bitcast_glsl_op(out_type, expected_type);
expr += '(';
expr += join(cast_op0, " ", op, " ", cast_op1);
expr += ')';
}
else
expr += join(cast_op0, " ", op, " ", cast_op1);
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1));
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
void CompilerGLSL::emit_unary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, const char *op)
{
bool forward = should_forward(op0);
emit_op(result_type, result_id, join(op, "(", to_unpacked_expression(op0), ")"), forward);
inherit_expression_dependencies(result_id, op0);
}
void CompilerGLSL::emit_binary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op)
{
bool forward = should_forward(op0) && should_forward(op1);
emit_op(result_type, result_id, join(op, "(", to_unpacked_expression(op0), ", ", to_unpacked_expression(op1), ")"),
forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
void CompilerGLSL::emit_unary_func_op_cast(uint32_t result_type, uint32_t result_id, uint32_t op0, const char *op,
SPIRType::BaseType input_type, SPIRType::BaseType expected_result_type)
{
auto &out_type = get<SPIRType>(result_type);
auto &expr_type = expression_type(op0);
auto expected_type = out_type;
// Bit-widths might be different in unary cases because we use it for SConvert/UConvert and friends.
expected_type.basetype = input_type;
expected_type.width = expr_type.width;
string cast_op = expr_type.basetype != input_type ? bitcast_glsl(expected_type, op0) : to_unpacked_expression(op0);
string expr;
if (out_type.basetype != expected_result_type)
{
expected_type.basetype = expected_result_type;
expected_type.width = out_type.width;
expr = bitcast_glsl_op(out_type, expected_type);
expr += '(';
expr += join(op, "(", cast_op, ")");
expr += ')';
}
else
{
expr += join(op, "(", cast_op, ")");
}
emit_op(result_type, result_id, expr, should_forward(op0));
inherit_expression_dependencies(result_id, op0);
}
void CompilerGLSL::emit_trinary_func_op_cast(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
uint32_t op2, const char *op, SPIRType::BaseType input_type)
{
auto &out_type = get<SPIRType>(result_type);
auto expected_type = out_type;
expected_type.basetype = input_type;
string cast_op0 =
expression_type(op0).basetype != input_type ? bitcast_glsl(expected_type, op0) : to_unpacked_expression(op0);
string cast_op1 =
expression_type(op1).basetype != input_type ? bitcast_glsl(expected_type, op1) : to_unpacked_expression(op1);
string cast_op2 =
expression_type(op2).basetype != input_type ? bitcast_glsl(expected_type, op2) : to_unpacked_expression(op2);
string expr;
if (out_type.basetype != input_type)
{
expr = bitcast_glsl_op(out_type, expected_type);
expr += '(';
expr += join(op, "(", cast_op0, ", ", cast_op1, ", ", cast_op2, ")");
expr += ')';
}
else
{
expr += join(op, "(", cast_op0, ", ", cast_op1, ", ", cast_op2, ")");
}
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1) && should_forward(op2));
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
inherit_expression_dependencies(result_id, op2);
}
void CompilerGLSL::emit_binary_func_op_cast(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
const char *op, SPIRType::BaseType input_type, bool skip_cast_if_equal_type)
{
string cast_op0, cast_op1;
auto expected_type = binary_op_bitcast_helper(cast_op0, cast_op1, input_type, op0, op1, skip_cast_if_equal_type);
auto &out_type = get<SPIRType>(result_type);
// Special case boolean outputs since relational opcodes output booleans instead of int/uint.
string expr;
if (out_type.basetype != input_type && out_type.basetype != SPIRType::Boolean)
{
expected_type.basetype = input_type;
expr = bitcast_glsl_op(out_type, expected_type);
expr += '(';
expr += join(op, "(", cast_op0, ", ", cast_op1, ")");
expr += ')';
}
else
{
expr += join(op, "(", cast_op0, ", ", cast_op1, ")");
}
emit_op(result_type, result_id, expr, should_forward(op0) && should_forward(op1));
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
}
void CompilerGLSL::emit_trinary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
uint32_t op2, const char *op)
{
bool forward = should_forward(op0) && should_forward(op1) && should_forward(op2);
emit_op(result_type, result_id,
join(op, "(", to_unpacked_expression(op0), ", ", to_unpacked_expression(op1), ", ",
to_unpacked_expression(op2), ")"),
forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
inherit_expression_dependencies(result_id, op2);
}
void CompilerGLSL::emit_quaternary_func_op(uint32_t result_type, uint32_t result_id, uint32_t op0, uint32_t op1,
uint32_t op2, uint32_t op3, const char *op)
{
bool forward = should_forward(op0) && should_forward(op1) && should_forward(op2) && should_forward(op3);
emit_op(result_type, result_id,
join(op, "(", to_unpacked_expression(op0), ", ", to_unpacked_expression(op1), ", ",
to_unpacked_expression(op2), ", ", to_unpacked_expression(op3), ")"),
forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
inherit_expression_dependencies(result_id, op2);
inherit_expression_dependencies(result_id, op3);
}
// EXT_shader_texture_lod only concerns fragment shaders so lod tex functions
// are not allowed in ES 2 vertex shaders. But SPIR-V only supports lod tex
// functions in vertex shaders so we revert those back to plain calls when
// the lod is a constant value of zero.
bool CompilerGLSL::check_explicit_lod_allowed(uint32_t lod)
{
auto &execution = get_entry_point();
bool allowed = !is_legacy_es() || execution.model == ExecutionModelFragment;
if (!allowed && lod != 0)
{
auto *lod_constant = maybe_get<SPIRConstant>(lod);
if (!lod_constant || lod_constant->scalar_f32() != 0.0f)
{
SPIRV_CROSS_THROW("Explicit lod not allowed in legacy ES non-fragment shaders.");
}
}
return allowed;
}
string CompilerGLSL::legacy_tex_op(const std::string &op, const SPIRType &imgtype, uint32_t lod, uint32_t tex)
{
const char *type;
switch (imgtype.image.dim)
{
case spv::Dim1D:
type = (imgtype.image.arrayed && !options.es) ? "1DArray" : "1D";
break;
case spv::Dim2D:
type = (imgtype.image.arrayed && !options.es) ? "2DArray" : "2D";
break;
case spv::Dim3D:
type = "3D";
break;
case spv::DimCube:
type = "Cube";
break;
case spv::DimRect:
type = "2DRect";
break;
case spv::DimBuffer:
type = "Buffer";
break;
case spv::DimSubpassData:
type = "2D";
break;
default:
type = "";
break;
}
bool use_explicit_lod = check_explicit_lod_allowed(lod);
if (op == "textureLod" || op == "textureProjLod" || op == "textureGrad" || op == "textureProjGrad")
{
if (is_legacy_es())
{
if (use_explicit_lod)
require_extension_internal("GL_EXT_shader_texture_lod");
}
else if (is_legacy())
require_extension_internal("GL_ARB_shader_texture_lod");
}
if (op == "textureLodOffset" || op == "textureProjLodOffset")
{
if (is_legacy_es())
SPIRV_CROSS_THROW(join(op, " not allowed in legacy ES"));
require_extension_internal("GL_EXT_gpu_shader4");
}
// GLES has very limited support for shadow samplers.
// Basically shadow2D and shadow2DProj work through EXT_shadow_samplers,
// everything else can just throw
if (image_is_comparison(imgtype, tex) && is_legacy_es())
{
if (op == "texture" || op == "textureProj")
require_extension_internal("GL_EXT_shadow_samplers");
else
SPIRV_CROSS_THROW(join(op, " not allowed on depth samplers in legacy ES"));
}
bool is_es_and_depth = is_legacy_es() && image_is_comparison(imgtype, tex);
std::string type_prefix = image_is_comparison(imgtype, tex) ? "shadow" : "texture";
if (op == "texture")
return is_es_and_depth ? join(type_prefix, type, "EXT") : join(type_prefix, type);
else if (op == "textureLod")
{
if (use_explicit_lod)
return join(type_prefix, type, is_legacy_es() ? "LodEXT" : "Lod");
else
return join(type_prefix, type);
}
else if (op == "textureProj")
return join(type_prefix, type, is_es_and_depth ? "ProjEXT" : "Proj");
else if (op == "textureGrad")
return join(type_prefix, type, is_legacy_es() ? "GradEXT" : is_legacy_desktop() ? "GradARB" : "Grad");
else if (op == "textureProjLod")
{
if (use_explicit_lod)
return join(type_prefix, type, is_legacy_es() ? "ProjLodEXT" : "ProjLod");
else
return join(type_prefix, type, "Proj");
}
else if (op == "textureLodOffset")
{
if (use_explicit_lod)
return join(type_prefix, type, "LodOffset");
else
return join(type_prefix, type);
}
else if (op == "textureProjGrad")
return join(type_prefix, type,
is_legacy_es() ? "ProjGradEXT" : is_legacy_desktop() ? "ProjGradARB" : "ProjGrad");
else if (op == "textureProjLodOffset")
{
if (use_explicit_lod)
return join(type_prefix, type, "ProjLodOffset");
else
return join(type_prefix, type, "ProjOffset");
}
else
{
SPIRV_CROSS_THROW(join("Unsupported legacy texture op: ", op));
}
}
bool CompilerGLSL::to_trivial_mix_op(const SPIRType &type, string &op, uint32_t left, uint32_t right, uint32_t lerp)
{
auto *cleft = maybe_get<SPIRConstant>(left);
auto *cright = maybe_get<SPIRConstant>(right);
auto &lerptype = expression_type(lerp);
// If our targets aren't constants, we cannot use construction.
if (!cleft || !cright)
return false;
// If our targets are spec constants, we cannot use construction.
if (cleft->specialization || cright->specialization)
return false;
// We can only use trivial construction if we have a scalar
// (should be possible to do it for vectors as well, but that is overkill for now).
if (lerptype.basetype != SPIRType::Boolean || lerptype.vecsize > 1)
return false;
// If our bool selects between 0 and 1, we can cast from bool instead, making our trivial constructor.
bool ret = false;
switch (type.basetype)
{
case SPIRType::Short:
case SPIRType::UShort:
ret = cleft->scalar_u16() == 0 && cright->scalar_u16() == 1;
break;
case SPIRType::Int:
case SPIRType::UInt:
ret = cleft->scalar() == 0 && cright->scalar() == 1;
break;
case SPIRType::Half:
ret = cleft->scalar_f16() == 0.0f && cright->scalar_f16() == 1.0f;
break;
case SPIRType::Float:
ret = cleft->scalar_f32() == 0.0f && cright->scalar_f32() == 1.0f;
break;
case SPIRType::Double:
ret = cleft->scalar_f64() == 0.0 && cright->scalar_f64() == 1.0;
break;
case SPIRType::Int64:
case SPIRType::UInt64:
ret = cleft->scalar_u64() == 0 && cright->scalar_u64() == 1;
break;
default:
break;
}
if (ret)
op = type_to_glsl_constructor(type);
return ret;
}
string CompilerGLSL::to_ternary_expression(const SPIRType &restype, uint32_t select, uint32_t true_value,
uint32_t false_value)
{
string expr;
auto &lerptype = expression_type(select);
if (lerptype.vecsize == 1)
expr = join(to_enclosed_expression(select), " ? ", to_enclosed_pointer_expression(true_value), " : ",
to_enclosed_pointer_expression(false_value));
else
{
auto swiz = [this](uint32_t expression, uint32_t i) { return to_extract_component_expression(expression, i); };
expr = type_to_glsl_constructor(restype);
expr += "(";
for (uint32_t i = 0; i < restype.vecsize; i++)
{
expr += swiz(select, i);
expr += " ? ";
expr += swiz(true_value, i);
expr += " : ";
expr += swiz(false_value, i);
if (i + 1 < restype.vecsize)
expr += ", ";
}
expr += ")";
}
return expr;
}
void CompilerGLSL::emit_mix_op(uint32_t result_type, uint32_t id, uint32_t left, uint32_t right, uint32_t lerp)
{
auto &lerptype = expression_type(lerp);
auto &restype = get<SPIRType>(result_type);
// If this results in a variable pointer, assume it may be written through.
if (restype.pointer)
{
register_write(left);
register_write(right);
}
string mix_op;
bool has_boolean_mix = backend.boolean_mix_support &&
((options.es && options.version >= 310) || (!options.es && options.version >= 450));
bool trivial_mix = to_trivial_mix_op(restype, mix_op, left, right, lerp);
// Cannot use boolean mix when the lerp argument is just one boolean,
// fall back to regular trinary statements.
if (lerptype.vecsize == 1)
has_boolean_mix = false;
// If we can reduce the mix to a simple cast, do so.
// This helps for cases like int(bool), uint(bool) which is implemented with
// OpSelect bool 1 0.
if (trivial_mix)
{
emit_unary_func_op(result_type, id, lerp, mix_op.c_str());
}
else if (!has_boolean_mix && lerptype.basetype == SPIRType::Boolean)
{
// Boolean mix not supported on desktop without extension.
// Was added in OpenGL 4.5 with ES 3.1 compat.
//
// Could use GL_EXT_shader_integer_mix on desktop at least,
// but Apple doesn't support it. :(
// Just implement it as ternary expressions.
auto expr = to_ternary_expression(get<SPIRType>(result_type), lerp, right, left);
emit_op(result_type, id, expr, should_forward(left) && should_forward(right) && should_forward(lerp));
inherit_expression_dependencies(id, left);
inherit_expression_dependencies(id, right);
inherit_expression_dependencies(id, lerp);
}
else
emit_trinary_func_op(result_type, id, left, right, lerp, "mix");
}
string CompilerGLSL::to_combined_image_sampler(uint32_t image_id, uint32_t samp_id)
{
// Keep track of the array indices we have used to load the image.
// We'll need to use the same array index into the combined image sampler array.
auto image_expr = to_expression(image_id);
string array_expr;
auto array_index = image_expr.find_first_of('[');
if (array_index != string::npos)
array_expr = image_expr.substr(array_index, string::npos);
auto &args = current_function->arguments;
// For GLSL and ESSL targets, we must enumerate all possible combinations for sampler2D(texture2D, sampler) and redirect
// all possible combinations into new sampler2D uniforms.
auto *image = maybe_get_backing_variable(image_id);
auto *samp = maybe_get_backing_variable(samp_id);
if (image)
image_id = image->self;
if (samp)
samp_id = samp->self;
auto image_itr = find_if(begin(args), end(args),
[image_id](const SPIRFunction::Parameter ¶m) { return param.id == image_id; });
auto sampler_itr = find_if(begin(args), end(args),
[samp_id](const SPIRFunction::Parameter ¶m) { return param.id == samp_id; });
if (image_itr != end(args) || sampler_itr != end(args))
{
// If any parameter originates from a parameter, we will find it in our argument list.
bool global_image = image_itr == end(args);
bool global_sampler = sampler_itr == end(args);
uint32_t iid = global_image ? image_id : uint32_t(image_itr - begin(args));
uint32_t sid = global_sampler ? samp_id : uint32_t(sampler_itr - begin(args));
auto &combined = current_function->combined_parameters;
auto itr = find_if(begin(combined), end(combined), [=](const SPIRFunction::CombinedImageSamplerParameter &p) {
return p.global_image == global_image && p.global_sampler == global_sampler && p.image_id == iid &&
p.sampler_id == sid;
});
if (itr != end(combined))
return to_expression(itr->id) + array_expr;
else
{
SPIRV_CROSS_THROW(
"Cannot find mapping for combined sampler parameter, was build_combined_image_samplers() used "
"before compile() was called?");
}
}
else
{
// For global sampler2D, look directly at the global remapping table.
auto &mapping = combined_image_samplers;
auto itr = find_if(begin(mapping), end(mapping), [image_id, samp_id](const CombinedImageSampler &combined) {
return combined.image_id == image_id && combined.sampler_id == samp_id;
});
if (itr != end(combined_image_samplers))
return to_expression(itr->combined_id) + array_expr;
else
{
SPIRV_CROSS_THROW("Cannot find mapping for combined sampler, was build_combined_image_samplers() used "
"before compile() was called?");
}
}
}
void CompilerGLSL::emit_sampled_image_op(uint32_t result_type, uint32_t result_id, uint32_t image_id, uint32_t samp_id)
{
if (options.vulkan_semantics && combined_image_samplers.empty())
{
emit_binary_func_op(result_type, result_id, image_id, samp_id,
type_to_glsl(get<SPIRType>(result_type), result_id).c_str());
// Make sure to suppress usage tracking. It is illegal to create temporaries of opaque types.
forwarded_temporaries.erase(result_id);
}
else
{
// Make sure to suppress usage tracking. It is illegal to create temporaries of opaque types.
emit_op(result_type, result_id, to_combined_image_sampler(image_id, samp_id), true, true);
}
}
static inline bool image_opcode_is_sample_no_dref(Op op)
{
switch (op)
{
case OpImageSampleExplicitLod:
case OpImageSampleImplicitLod:
case OpImageSampleProjExplicitLod:
case OpImageSampleProjImplicitLod:
case OpImageFetch:
case OpImageRead:
case OpImageSparseSampleExplicitLod:
case OpImageSparseSampleImplicitLod:
case OpImageSparseSampleProjExplicitLod:
case OpImageSparseSampleProjImplicitLod:
case OpImageSparseFetch:
case OpImageSparseRead:
return true;
default:
return false;
}
}
void CompilerGLSL::emit_texture_op(const Instruction &i)
{
auto *ops = stream(i);
auto op = static_cast<Op>(i.op);
uint32_t length = i.length;
SmallVector<uint32_t> inherited_expressions;
uint32_t result_type_id = ops[0];
uint32_t id = ops[1];
uint32_t img = ops[2];
uint32_t coord = ops[3];
uint32_t dref = 0;
uint32_t comp = 0;
bool gather = false;
bool proj = false;
bool fetch = false;
const uint32_t *opt = nullptr;
auto &result_type = get<SPIRType>(result_type_id);
inherited_expressions.push_back(coord);
// Make sure non-uniform decoration is back-propagated to where it needs to be.
if (has_decoration(img, DecorationNonUniformEXT))
propagate_nonuniform_qualifier(img);
switch (op)
{
case OpImageSampleDrefImplicitLod:
case OpImageSampleDrefExplicitLod:
dref = ops[4];
opt = &ops[5];
length -= 5;
break;
case OpImageSampleProjDrefImplicitLod:
case OpImageSampleProjDrefExplicitLod:
dref = ops[4];
opt = &ops[5];
length -= 5;
proj = true;
break;
case OpImageDrefGather:
dref = ops[4];
opt = &ops[5];
length -= 5;
gather = true;
break;
case OpImageGather:
comp = ops[4];
opt = &ops[5];
length -= 5;
gather = true;
break;
case OpImageFetch:
case OpImageRead: // Reads == fetches in Metal (other langs will not get here)
opt = &ops[4];
length -= 4;
fetch = true;
break;
case OpImageSampleProjImplicitLod:
case OpImageSampleProjExplicitLod:
opt = &ops[4];
length -= 4;
proj = true;
break;
default:
opt = &ops[4];
length -= 4;
break;
}
// Bypass pointers because we need the real image struct
auto &type = expression_type(img);
auto &imgtype = get<SPIRType>(type.self);
uint32_t coord_components = 0;
switch (imgtype.image.dim)
{
case spv::Dim1D:
coord_components = 1;
break;
case spv::Dim2D:
coord_components = 2;
break;
case spv::Dim3D:
coord_components = 3;
break;
case spv::DimCube:
coord_components = 3;
break;
case spv::DimBuffer:
coord_components = 1;
break;
default:
coord_components = 2;
break;
}
if (dref)
inherited_expressions.push_back(dref);
if (proj)
coord_components++;
if (imgtype.image.arrayed)
coord_components++;
uint32_t bias = 0;
uint32_t lod = 0;
uint32_t grad_x = 0;
uint32_t grad_y = 0;
uint32_t coffset = 0;
uint32_t offset = 0;
uint32_t coffsets = 0;
uint32_t sample = 0;
uint32_t minlod = 0;
uint32_t flags = 0;
if (length)
{
flags = *opt++;
length--;
}
auto test = [&](uint32_t &v, uint32_t flag) {
if (length && (flags & flag))
{
v = *opt++;
inherited_expressions.push_back(v);
length--;
}
};
test(bias, ImageOperandsBiasMask);
test(lod, ImageOperandsLodMask);
test(grad_x, ImageOperandsGradMask);
test(grad_y, ImageOperandsGradMask);
test(coffset, ImageOperandsConstOffsetMask);
test(offset, ImageOperandsOffsetMask);
test(coffsets, ImageOperandsConstOffsetsMask);
test(sample, ImageOperandsSampleMask);
test(minlod, ImageOperandsMinLodMask);
string expr;
bool forward = false;
expr += to_function_name(img, imgtype, !!fetch, !!gather, !!proj, !!coffsets, (!!coffset || !!offset),
(!!grad_x || !!grad_y), !!dref, lod, minlod);
expr += "(";
expr += to_function_args(img, imgtype, fetch, gather, proj, coord, coord_components, dref, grad_x, grad_y, lod,
coffset, offset, bias, comp, sample, minlod, &forward);
expr += ")";
// texture(samplerXShadow) returns float. shadowX() returns vec4. Swizzle here.
if (is_legacy() && image_is_comparison(imgtype, img))
expr += ".r";
// Sampling from a texture which was deduced to be a depth image, might actually return 1 component here.
// Remap back to 4 components as sampling opcodes expect.
if (backend.comparison_image_samples_scalar && image_opcode_is_sample_no_dref(op))
{
bool image_is_depth = false;
const auto *combined = maybe_get<SPIRCombinedImageSampler>(img);
uint32_t image_id = combined ? combined->image : img;
if (combined && image_is_comparison(imgtype, combined->image))
image_is_depth = true;
else if (image_is_comparison(imgtype, img))
image_is_depth = true;
// We must also check the backing variable for the image.
// We might have loaded an OpImage, and used that handle for two different purposes.
// Once with comparison, once without.
auto *image_variable = maybe_get_backing_variable(image_id);
if (image_variable && image_is_comparison(get<SPIRType>(image_variable->basetype), image_variable->self))
image_is_depth = true;
if (image_is_depth)
expr = remap_swizzle(result_type, 1, expr);
}
if (!backend.support_small_type_sampling_result && result_type.width < 32)
{
// Just value cast (narrowing) to expected type since we cannot rely on narrowing to work automatically.
// Hopefully compiler picks this up and converts the texturing instruction to the appropriate precision.
expr = join(type_to_glsl_constructor(result_type), "(", expr, ")");
}
// Deals with reads from MSL. We might need to downconvert to fewer components.
if (op == OpImageRead)
expr = remap_swizzle(result_type, 4, expr);
emit_op(result_type_id, id, expr, forward);
for (auto &inherit : inherited_expressions)
inherit_expression_dependencies(id, inherit);
switch (op)
{
case OpImageSampleDrefImplicitLod:
case OpImageSampleImplicitLod:
case OpImageSampleProjImplicitLod:
case OpImageSampleProjDrefImplicitLod:
register_control_dependent_expression(id);
break;
default:
break;
}
}
bool CompilerGLSL::expression_is_constant_null(uint32_t id) const
{
auto *c = maybe_get<SPIRConstant>(id);
if (!c)
return false;
return c->constant_is_null();
}
// Returns the function name for a texture sampling function for the specified image and sampling characteristics.
// For some subclasses, the function is a method on the specified image.
string CompilerGLSL::to_function_name(uint32_t tex, const SPIRType &imgtype, bool is_fetch, bool is_gather,
bool is_proj, bool has_array_offsets, bool has_offset, bool has_grad, bool,
uint32_t lod, uint32_t minlod)
{
if (minlod != 0)
SPIRV_CROSS_THROW("Sparse texturing not yet supported.");
string fname;
// textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL for some reason.
// To emulate this, we will have to use textureGrad with a constant gradient of 0.
// The workaround will assert that the LOD is in fact constant 0, or we cannot emit correct code.
// This happens for HLSL SampleCmpLevelZero on Texture2DArray and TextureCube.
bool workaround_lod_array_shadow_as_grad = false;
if (((imgtype.image.arrayed && imgtype.image.dim == Dim2D) || imgtype.image.dim == DimCube) &&
image_is_comparison(imgtype, tex) && lod)
{
if (!expression_is_constant_null(lod))
{
SPIRV_CROSS_THROW(
"textureLod on sampler2DArrayShadow is not constant 0.0. This cannot be expressed in GLSL.");
}
workaround_lod_array_shadow_as_grad = true;
}
if (is_fetch)
fname += "texelFetch";
else
{
fname += "texture";
if (is_gather)
fname += "Gather";
if (has_array_offsets)
fname += "Offsets";
if (is_proj)
fname += "Proj";
if (has_grad || workaround_lod_array_shadow_as_grad)
fname += "Grad";
if (!!lod && !workaround_lod_array_shadow_as_grad)
fname += "Lod";
}
if (has_offset)
fname += "Offset";
return is_legacy() ? legacy_tex_op(fname, imgtype, lod, tex) : fname;
}
std::string CompilerGLSL::convert_separate_image_to_expression(uint32_t id)
{
auto *var = maybe_get_backing_variable(id);
// If we are fetching from a plain OpTypeImage, we must combine with a dummy sampler in GLSL.
// In Vulkan GLSL, we can make use of the newer GL_EXT_samplerless_texture_functions.
if (var)
{
auto &type = get<SPIRType>(var->basetype);
if (type.basetype == SPIRType::Image && type.image.sampled == 1 && type.image.dim != DimBuffer)
{
if (options.vulkan_semantics)
{
// Newer glslang supports this extension to deal with texture2D as argument to texture functions.
if (dummy_sampler_id)
SPIRV_CROSS_THROW("Vulkan GLSL should not have a dummy sampler for combining.");
require_extension_internal("GL_EXT_samplerless_texture_functions");
}
else
{
if (!dummy_sampler_id)
SPIRV_CROSS_THROW(
"Cannot find dummy sampler ID. Was build_dummy_sampler_for_combined_images() called?");
return to_combined_image_sampler(id, dummy_sampler_id);
}
}
}
return to_expression(id);
}
// Returns the function args for a texture sampling function for the specified image and sampling characteristics.
string CompilerGLSL::to_function_args(uint32_t img, const SPIRType &imgtype, bool is_fetch, bool is_gather,
bool is_proj, uint32_t coord, uint32_t coord_components, uint32_t dref,
uint32_t grad_x, uint32_t grad_y, uint32_t lod, uint32_t coffset, uint32_t offset,
uint32_t bias, uint32_t comp, uint32_t sample, uint32_t /*minlod*/,
bool *p_forward)
{
string farg_str;
if (is_fetch)
farg_str = convert_separate_image_to_expression(img);
else
farg_str = to_expression(img);
bool swizz_func = backend.swizzle_is_function;
auto swizzle = [swizz_func](uint32_t comps, uint32_t in_comps) -> const char * {
if (comps == in_comps)
return "";
switch (comps)
{
case 1:
return ".x";
case 2:
return swizz_func ? ".xy()" : ".xy";
case 3:
return swizz_func ? ".xyz()" : ".xyz";
default:
return "";
}
};
bool forward = should_forward(coord);
// The IR can give us more components than we need, so chop them off as needed.
auto swizzle_expr = swizzle(coord_components, expression_type(coord).vecsize);
// Only enclose the UV expression if needed.
auto coord_expr = (*swizzle_expr == '\0') ? to_expression(coord) : (to_enclosed_expression(coord) + swizzle_expr);
// texelFetch only takes int, not uint.
auto &coord_type = expression_type(coord);
if (coord_type.basetype == SPIRType::UInt)
{
auto expected_type = coord_type;
expected_type.vecsize = coord_components;
expected_type.basetype = SPIRType::Int;
coord_expr = bitcast_expression(expected_type, coord_type.basetype, coord_expr);
}
// textureLod on sampler2DArrayShadow and samplerCubeShadow does not exist in GLSL for some reason.
// To emulate this, we will have to use textureGrad with a constant gradient of 0.
// The workaround will assert that the LOD is in fact constant 0, or we cannot emit correct code.
// This happens for HLSL SampleCmpLevelZero on Texture2DArray and TextureCube.
bool workaround_lod_array_shadow_as_grad =
((imgtype.image.arrayed && imgtype.image.dim == Dim2D) || imgtype.image.dim == DimCube) &&
image_is_comparison(imgtype, img) && lod;
if (dref)
{
forward = forward && should_forward(dref);
// SPIR-V splits dref and coordinate.
if (is_gather || coord_components == 4) // GLSL also splits the arguments in two. Same for textureGather.
{
farg_str += ", ";
farg_str += to_expression(coord);
farg_str += ", ";
farg_str += to_expression(dref);
}
else if (is_proj)
{
// Have to reshuffle so we get vec4(coord, dref, proj), special case.
// Other shading languages splits up the arguments for coord and compare value like SPIR-V.
// The coordinate type for textureProj shadow is always vec4 even for sampler1DShadow.
farg_str += ", vec4(";
if (imgtype.image.dim == Dim1D)
{
// Could reuse coord_expr, but we will mess up the temporary usage checking.
farg_str += to_enclosed_expression(coord) + ".x";
farg_str += ", ";
farg_str += "0.0, ";
farg_str += to_expression(dref);
farg_str += ", ";
farg_str += to_enclosed_expression(coord) + ".y)";
}
else if (imgtype.image.dim == Dim2D)
{
// Could reuse coord_expr, but we will mess up the temporary usage checking.
farg_str += to_enclosed_expression(coord) + (swizz_func ? ".xy()" : ".xy");
farg_str += ", ";
farg_str += to_expression(dref);
farg_str += ", ";
farg_str += to_enclosed_expression(coord) + ".z)";
}
else
SPIRV_CROSS_THROW("Invalid type for textureProj with shadow.");
}
else
{
// Create a composite which merges coord/dref into a single vector.
auto type = expression_type(coord);
type.vecsize = coord_components + 1;
farg_str += ", ";
farg_str += type_to_glsl_constructor(type);
farg_str += "(";
farg_str += coord_expr;
farg_str += ", ";
farg_str += to_expression(dref);
farg_str += ")";
}
}
else
{
farg_str += ", ";
farg_str += coord_expr;
}
if (grad_x || grad_y)
{
forward = forward && should_forward(grad_x);
forward = forward && should_forward(grad_y);
farg_str += ", ";
farg_str += to_expression(grad_x);
farg_str += ", ";
farg_str += to_expression(grad_y);
}
if (lod)
{
if (workaround_lod_array_shadow_as_grad)
{
// Implement textureGrad() instead. LOD == 0.0 is implemented as gradient of 0.0.
// Implementing this as plain texture() is not safe on some implementations.
if (imgtype.image.dim == Dim2D)
farg_str += ", vec2(0.0), vec2(0.0)";
else if (imgtype.image.dim == DimCube)
farg_str += ", vec3(0.0), vec3(0.0)";
}
else
{
if (check_explicit_lod_allowed(lod))
{
forward = forward && should_forward(lod);
farg_str += ", ";
auto &lod_expr_type = expression_type(lod);
// Lod expression for TexelFetch in GLSL must be int, and only int.
if (is_fetch && imgtype.image.dim != DimBuffer && !imgtype.image.ms &&
lod_expr_type.basetype != SPIRType::Int)
{
farg_str += join("int(", to_expression(lod), ")");
}
else
{
farg_str += to_expression(lod);
}
}
}
}
else if (is_fetch && imgtype.image.dim != DimBuffer && !imgtype.image.ms)
{
// Lod argument is optional in OpImageFetch, but we require a LOD value, pick 0 as the default.
farg_str += ", 0";
}
if (coffset)
{
forward = forward && should_forward(coffset);
farg_str += ", ";
farg_str += to_expression(coffset);
}
else if (offset)
{
forward = forward && should_forward(offset);
farg_str += ", ";
farg_str += to_expression(offset);
}
if (bias)
{
forward = forward && should_forward(bias);
farg_str += ", ";
farg_str += to_expression(bias);
}
if (comp)
{
forward = forward && should_forward(comp);
farg_str += ", ";
farg_str += to_expression(comp);
}
if (sample)
{
farg_str += ", ";
farg_str += to_expression(sample);
}
*p_forward = forward;
return farg_str;
}
void CompilerGLSL::emit_glsl_op(uint32_t result_type, uint32_t id, uint32_t eop, const uint32_t *args, uint32_t length)
{
auto op = static_cast<GLSLstd450>(eop);
if (is_legacy() && is_unsigned_glsl_opcode(op))
SPIRV_CROSS_THROW("Unsigned integers are not supported on legacy GLSL targets.");
// If we need to do implicit bitcasts, make sure we do it with the correct type.
uint32_t integer_width = get_integer_width_for_glsl_instruction(op, args, length);
auto int_type = to_signed_basetype(integer_width);
auto uint_type = to_unsigned_basetype(integer_width);
switch (op)
{
// FP fiddling
case GLSLstd450Round:
emit_unary_func_op(result_type, id, args[0], "round");
break;
case GLSLstd450RoundEven:
if ((options.es && options.version >= 300) || (!options.es && options.version >= 130))
emit_unary_func_op(result_type, id, args[0], "roundEven");
else
SPIRV_CROSS_THROW("roundEven supported only in ESSL 300 and GLSL 130 and up.");
break;
case GLSLstd450Trunc:
emit_unary_func_op(result_type, id, args[0], "trunc");
break;
case GLSLstd450SAbs:
emit_unary_func_op_cast(result_type, id, args[0], "abs", int_type, int_type);
break;
case GLSLstd450FAbs:
emit_unary_func_op(result_type, id, args[0], "abs");
break;
case GLSLstd450SSign:
emit_unary_func_op_cast(result_type, id, args[0], "sign", int_type, int_type);
break;
case GLSLstd450FSign:
emit_unary_func_op(result_type, id, args[0], "sign");
break;
case GLSLstd450Floor:
emit_unary_func_op(result_type, id, args[0], "floor");
break;
case GLSLstd450Ceil:
emit_unary_func_op(result_type, id, args[0], "ceil");
break;
case GLSLstd450Fract:
emit_unary_func_op(result_type, id, args[0], "fract");
break;
case GLSLstd450Radians:
emit_unary_func_op(result_type, id, args[0], "radians");
break;
case GLSLstd450Degrees:
emit_unary_func_op(result_type, id, args[0], "degrees");
break;
case GLSLstd450Fma:
if ((!options.es && options.version < 400) || (options.es && options.version < 320))
{
auto expr = join(to_enclosed_expression(args[0]), " * ", to_enclosed_expression(args[1]), " + ",
to_enclosed_expression(args[2]));
emit_op(result_type, id, expr,
should_forward(args[0]) && should_forward(args[1]) && should_forward(args[2]));
for (uint32_t i = 0; i < 3; i++)
inherit_expression_dependencies(id, args[i]);
}
else
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "fma");
break;
case GLSLstd450Modf:
register_call_out_argument(args[1]);
forced_temporaries.insert(id);
emit_binary_func_op(result_type, id, args[0], args[1], "modf");
break;
case GLSLstd450ModfStruct:
{
forced_temporaries.insert(id);
auto &type = get<SPIRType>(result_type);
emit_uninitialized_temporary_expression(result_type, id);
statement(to_expression(id), ".", to_member_name(type, 0), " = ", "modf(", to_expression(args[0]), ", ",
to_expression(id), ".", to_member_name(type, 1), ");");
break;
}
// Minmax
case GLSLstd450UMin:
emit_binary_func_op_cast(result_type, id, args[0], args[1], "min", uint_type, false);
break;
case GLSLstd450SMin:
emit_binary_func_op_cast(result_type, id, args[0], args[1], "min", int_type, false);
break;
case GLSLstd450FMin:
emit_binary_func_op(result_type, id, args[0], args[1], "min");
break;
case GLSLstd450FMax:
emit_binary_func_op(result_type, id, args[0], args[1], "max");
break;
case GLSLstd450UMax:
emit_binary_func_op_cast(result_type, id, args[0], args[1], "max", uint_type, false);
break;
case GLSLstd450SMax:
emit_binary_func_op_cast(result_type, id, args[0], args[1], "max", int_type, false);
break;
case GLSLstd450FClamp:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "clamp");
break;
case GLSLstd450UClamp:
emit_trinary_func_op_cast(result_type, id, args[0], args[1], args[2], "clamp", uint_type);
break;
case GLSLstd450SClamp:
emit_trinary_func_op_cast(result_type, id, args[0], args[1], args[2], "clamp", int_type);
break;
// Trig
case GLSLstd450Sin:
emit_unary_func_op(result_type, id, args[0], "sin");
break;
case GLSLstd450Cos:
emit_unary_func_op(result_type, id, args[0], "cos");
break;
case GLSLstd450Tan:
emit_unary_func_op(result_type, id, args[0], "tan");
break;
case GLSLstd450Asin:
emit_unary_func_op(result_type, id, args[0], "asin");
break;
case GLSLstd450Acos:
emit_unary_func_op(result_type, id, args[0], "acos");
break;
case GLSLstd450Atan:
emit_unary_func_op(result_type, id, args[0], "atan");
break;
case GLSLstd450Sinh:
emit_unary_func_op(result_type, id, args[0], "sinh");
break;
case GLSLstd450Cosh:
emit_unary_func_op(result_type, id, args[0], "cosh");
break;
case GLSLstd450Tanh:
emit_unary_func_op(result_type, id, args[0], "tanh");
break;
case GLSLstd450Asinh:
emit_unary_func_op(result_type, id, args[0], "asinh");
break;
case GLSLstd450Acosh:
emit_unary_func_op(result_type, id, args[0], "acosh");
break;
case GLSLstd450Atanh:
emit_unary_func_op(result_type, id, args[0], "atanh");
break;
case GLSLstd450Atan2:
emit_binary_func_op(result_type, id, args[0], args[1], "atan");
break;
// Exponentials
case GLSLstd450Pow:
emit_binary_func_op(result_type, id, args[0], args[1], "pow");
break;
case GLSLstd450Exp:
emit_unary_func_op(result_type, id, args[0], "exp");
break;
case GLSLstd450Log:
emit_unary_func_op(result_type, id, args[0], "log");
break;
case GLSLstd450Exp2:
emit_unary_func_op(result_type, id, args[0], "exp2");
break;
case GLSLstd450Log2:
emit_unary_func_op(result_type, id, args[0], "log2");
break;
case GLSLstd450Sqrt:
emit_unary_func_op(result_type, id, args[0], "sqrt");
break;
case GLSLstd450InverseSqrt:
emit_unary_func_op(result_type, id, args[0], "inversesqrt");
break;
// Matrix math
case GLSLstd450Determinant:
emit_unary_func_op(result_type, id, args[0], "determinant");
break;
case GLSLstd450MatrixInverse:
emit_unary_func_op(result_type, id, args[0], "inverse");
break;
// Lerping
case GLSLstd450FMix:
case GLSLstd450IMix:
{
emit_mix_op(result_type, id, args[0], args[1], args[2]);
break;
}
case GLSLstd450Step:
emit_binary_func_op(result_type, id, args[0], args[1], "step");
break;
case GLSLstd450SmoothStep:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "smoothstep");
break;
// Packing
case GLSLstd450Frexp:
register_call_out_argument(args[1]);
forced_temporaries.insert(id);
emit_binary_func_op(result_type, id, args[0], args[1], "frexp");
break;
case GLSLstd450FrexpStruct:
{
forced_temporaries.insert(id);
auto &type = get<SPIRType>(result_type);
emit_uninitialized_temporary_expression(result_type, id);
statement(to_expression(id), ".", to_member_name(type, 0), " = ", "frexp(", to_expression(args[0]), ", ",
to_expression(id), ".", to_member_name(type, 1), ");");
break;
}
case GLSLstd450Ldexp:
emit_binary_func_op(result_type, id, args[0], args[1], "ldexp");
break;
case GLSLstd450PackSnorm4x8:
emit_unary_func_op(result_type, id, args[0], "packSnorm4x8");
break;
case GLSLstd450PackUnorm4x8:
emit_unary_func_op(result_type, id, args[0], "packUnorm4x8");
break;
case GLSLstd450PackSnorm2x16:
emit_unary_func_op(result_type, id, args[0], "packSnorm2x16");
break;
case GLSLstd450PackUnorm2x16:
emit_unary_func_op(result_type, id, args[0], "packUnorm2x16");
break;
case GLSLstd450PackHalf2x16:
emit_unary_func_op(result_type, id, args[0], "packHalf2x16");
break;
case GLSLstd450UnpackSnorm4x8:
emit_unary_func_op(result_type, id, args[0], "unpackSnorm4x8");
break;
case GLSLstd450UnpackUnorm4x8:
emit_unary_func_op(result_type, id, args[0], "unpackUnorm4x8");
break;
case GLSLstd450UnpackSnorm2x16:
emit_unary_func_op(result_type, id, args[0], "unpackSnorm2x16");
break;
case GLSLstd450UnpackUnorm2x16:
emit_unary_func_op(result_type, id, args[0], "unpackUnorm2x16");
break;
case GLSLstd450UnpackHalf2x16:
emit_unary_func_op(result_type, id, args[0], "unpackHalf2x16");
break;
case GLSLstd450PackDouble2x32:
emit_unary_func_op(result_type, id, args[0], "packDouble2x32");
break;
case GLSLstd450UnpackDouble2x32:
emit_unary_func_op(result_type, id, args[0], "unpackDouble2x32");
break;
// Vector math
case GLSLstd450Length:
emit_unary_func_op(result_type, id, args[0], "length");
break;
case GLSLstd450Distance:
emit_binary_func_op(result_type, id, args[0], args[1], "distance");
break;
case GLSLstd450Cross:
emit_binary_func_op(result_type, id, args[0], args[1], "cross");
break;
case GLSLstd450Normalize:
emit_unary_func_op(result_type, id, args[0], "normalize");
break;
case GLSLstd450FaceForward:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "faceforward");
break;
case GLSLstd450Reflect:
emit_binary_func_op(result_type, id, args[0], args[1], "reflect");
break;
case GLSLstd450Refract:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "refract");
break;
// Bit-fiddling
case GLSLstd450FindILsb:
emit_unary_func_op(result_type, id, args[0], "findLSB");
break;
case GLSLstd450FindSMsb:
emit_unary_func_op_cast(result_type, id, args[0], "findMSB", int_type, int_type);
break;
case GLSLstd450FindUMsb:
emit_unary_func_op_cast(result_type, id, args[0], "findMSB", uint_type,
int_type); // findMSB always returns int.
break;
// Multisampled varying
case GLSLstd450InterpolateAtCentroid:
emit_unary_func_op(result_type, id, args[0], "interpolateAtCentroid");
break;
case GLSLstd450InterpolateAtSample:
emit_binary_func_op(result_type, id, args[0], args[1], "interpolateAtSample");
break;
case GLSLstd450InterpolateAtOffset:
emit_binary_func_op(result_type, id, args[0], args[1], "interpolateAtOffset");
break;
case GLSLstd450NMin:
case GLSLstd450NMax:
{
emit_nminmax_op(result_type, id, args[0], args[1], op);
break;
}
case GLSLstd450NClamp:
{
// Make sure we have a unique ID here to avoid aliasing the extra sub-expressions between clamp and NMin sub-op.
// IDs cannot exceed 24 bits, so we can make use of the higher bits for some unique flags.
uint32_t &max_id = extra_sub_expressions[id | 0x80000000u];
if (!max_id)
max_id = ir.increase_bound_by(1);
// Inherit precision qualifiers.
ir.meta[max_id] = ir.meta[id];
emit_nminmax_op(result_type, max_id, args[0], args[1], GLSLstd450NMax);
emit_nminmax_op(result_type, id, max_id, args[2], GLSLstd450NMin);
break;
}
default:
statement("// unimplemented GLSL op ", eop);
break;
}
}
void CompilerGLSL::emit_nminmax_op(uint32_t result_type, uint32_t id, uint32_t op0, uint32_t op1, GLSLstd450 op)
{
// Need to emulate this call.
uint32_t &ids = extra_sub_expressions[id];
if (!ids)
{
ids = ir.increase_bound_by(5);
auto btype = get<SPIRType>(result_type);
btype.basetype = SPIRType::Boolean;
set<SPIRType>(ids, btype);
}
uint32_t btype_id = ids + 0;
uint32_t left_nan_id = ids + 1;
uint32_t right_nan_id = ids + 2;
uint32_t tmp_id = ids + 3;
uint32_t mixed_first_id = ids + 4;
// Inherit precision qualifiers.
ir.meta[tmp_id] = ir.meta[id];
ir.meta[mixed_first_id] = ir.meta[id];
emit_unary_func_op(btype_id, left_nan_id, op0, "isnan");
emit_unary_func_op(btype_id, right_nan_id, op1, "isnan");
emit_binary_func_op(result_type, tmp_id, op0, op1, op == GLSLstd450NMin ? "min" : "max");
emit_mix_op(result_type, mixed_first_id, tmp_id, op1, left_nan_id);
emit_mix_op(result_type, id, mixed_first_id, op0, right_nan_id);
}
void CompilerGLSL::emit_spv_amd_shader_ballot_op(uint32_t result_type, uint32_t id, uint32_t eop, const uint32_t *args,
uint32_t)
{
require_extension_internal("GL_AMD_shader_ballot");
enum AMDShaderBallot
{
SwizzleInvocationsAMD = 1,
SwizzleInvocationsMaskedAMD = 2,
WriteInvocationAMD = 3,
MbcntAMD = 4
};
auto op = static_cast<AMDShaderBallot>(eop);
switch (op)
{
case SwizzleInvocationsAMD:
emit_binary_func_op(result_type, id, args[0], args[1], "swizzleInvocationsAMD");
register_control_dependent_expression(id);
break;
case SwizzleInvocationsMaskedAMD:
emit_binary_func_op(result_type, id, args[0], args[1], "swizzleInvocationsMaskedAMD");
register_control_dependent_expression(id);
break;
case WriteInvocationAMD:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "writeInvocationAMD");
register_control_dependent_expression(id);
break;
case MbcntAMD:
emit_unary_func_op(result_type, id, args[0], "mbcntAMD");
register_control_dependent_expression(id);
break;
default:
statement("// unimplemented SPV AMD shader ballot op ", eop);
break;
}
}
void CompilerGLSL::emit_spv_amd_shader_explicit_vertex_parameter_op(uint32_t result_type, uint32_t id, uint32_t eop,
const uint32_t *args, uint32_t)
{
require_extension_internal("GL_AMD_shader_explicit_vertex_parameter");
enum AMDShaderExplicitVertexParameter
{
InterpolateAtVertexAMD = 1
};
auto op = static_cast<AMDShaderExplicitVertexParameter>(eop);
switch (op)
{
case InterpolateAtVertexAMD:
emit_binary_func_op(result_type, id, args[0], args[1], "interpolateAtVertexAMD");
break;
default:
statement("// unimplemented SPV AMD shader explicit vertex parameter op ", eop);
break;
}
}
void CompilerGLSL::emit_spv_amd_shader_trinary_minmax_op(uint32_t result_type, uint32_t id, uint32_t eop,
const uint32_t *args, uint32_t)
{
require_extension_internal("GL_AMD_shader_trinary_minmax");
enum AMDShaderTrinaryMinMax
{
FMin3AMD = 1,
UMin3AMD = 2,
SMin3AMD = 3,
FMax3AMD = 4,
UMax3AMD = 5,
SMax3AMD = 6,
FMid3AMD = 7,
UMid3AMD = 8,
SMid3AMD = 9
};
auto op = static_cast<AMDShaderTrinaryMinMax>(eop);
switch (op)
{
case FMin3AMD:
case UMin3AMD:
case SMin3AMD:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "min3");
break;
case FMax3AMD:
case UMax3AMD:
case SMax3AMD:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "max3");
break;
case FMid3AMD:
case UMid3AMD:
case SMid3AMD:
emit_trinary_func_op(result_type, id, args[0], args[1], args[2], "mid3");
break;
default:
statement("// unimplemented SPV AMD shader trinary minmax op ", eop);
break;
}
}
void CompilerGLSL::emit_spv_amd_gcn_shader_op(uint32_t result_type, uint32_t id, uint32_t eop, const uint32_t *args,
uint32_t)
{
require_extension_internal("GL_AMD_gcn_shader");
enum AMDGCNShader
{
CubeFaceIndexAMD = 1,
CubeFaceCoordAMD = 2,
TimeAMD = 3
};
auto op = static_cast<AMDGCNShader>(eop);
switch (op)
{
case CubeFaceIndexAMD:
emit_unary_func_op(result_type, id, args[0], "cubeFaceIndexAMD");
break;
case CubeFaceCoordAMD:
emit_unary_func_op(result_type, id, args[0], "cubeFaceCoordAMD");
break;
case TimeAMD:
{
string expr = "timeAMD()";
emit_op(result_type, id, expr, true);
register_control_dependent_expression(id);
break;
}
default:
statement("// unimplemented SPV AMD gcn shader op ", eop);
break;
}
}
void CompilerGLSL::emit_subgroup_op(const Instruction &i)
{
const uint32_t *ops = stream(i);
auto op = static_cast<Op>(i.op);
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Can only use subgroup operations in Vulkan semantics.");
switch (op)
{
case OpGroupNonUniformElect:
require_extension_internal("GL_KHR_shader_subgroup_basic");
break;
case OpGroupNonUniformBroadcast:
case OpGroupNonUniformBroadcastFirst:
case OpGroupNonUniformBallot:
case OpGroupNonUniformInverseBallot:
case OpGroupNonUniformBallotBitExtract:
case OpGroupNonUniformBallotBitCount:
case OpGroupNonUniformBallotFindLSB:
case OpGroupNonUniformBallotFindMSB:
require_extension_internal("GL_KHR_shader_subgroup_ballot");
break;
case OpGroupNonUniformShuffle:
case OpGroupNonUniformShuffleXor:
require_extension_internal("GL_KHR_shader_subgroup_shuffle");
break;
case OpGroupNonUniformShuffleUp:
case OpGroupNonUniformShuffleDown:
require_extension_internal("GL_KHR_shader_subgroup_shuffle_relative");
break;
case OpGroupNonUniformAll:
case OpGroupNonUniformAny:
case OpGroupNonUniformAllEqual:
require_extension_internal("GL_KHR_shader_subgroup_vote");
break;
case OpGroupNonUniformFAdd:
case OpGroupNonUniformFMul:
case OpGroupNonUniformFMin:
case OpGroupNonUniformFMax:
case OpGroupNonUniformIAdd:
case OpGroupNonUniformIMul:
case OpGroupNonUniformSMin:
case OpGroupNonUniformSMax:
case OpGroupNonUniformUMin:
case OpGroupNonUniformUMax:
case OpGroupNonUniformBitwiseAnd:
case OpGroupNonUniformBitwiseOr:
case OpGroupNonUniformBitwiseXor:
{
auto operation = static_cast<GroupOperation>(ops[3]);
if (operation == GroupOperationClusteredReduce)
{
require_extension_internal("GL_KHR_shader_subgroup_clustered");
}
else if (operation == GroupOperationExclusiveScan || operation == GroupOperationInclusiveScan ||
operation == GroupOperationReduce)
{
require_extension_internal("GL_KHR_shader_subgroup_arithmetic");
}
else
SPIRV_CROSS_THROW("Invalid group operation.");
break;
}
case OpGroupNonUniformQuadSwap:
case OpGroupNonUniformQuadBroadcast:
require_extension_internal("GL_KHR_shader_subgroup_quad");
break;
default:
SPIRV_CROSS_THROW("Invalid opcode for subgroup.");
}
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto scope = static_cast<Scope>(get<SPIRConstant>(ops[2]).scalar());
if (scope != ScopeSubgroup)
SPIRV_CROSS_THROW("Only subgroup scope is supported.");
switch (op)
{
case OpGroupNonUniformElect:
emit_op(result_type, id, "subgroupElect()", true);
break;
case OpGroupNonUniformBroadcast:
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupBroadcast");
break;
case OpGroupNonUniformBroadcastFirst:
emit_unary_func_op(result_type, id, ops[3], "subgroupBroadcastFirst");
break;
case OpGroupNonUniformBallot:
emit_unary_func_op(result_type, id, ops[3], "subgroupBallot");
break;
case OpGroupNonUniformInverseBallot:
emit_unary_func_op(result_type, id, ops[3], "subgroupInverseBallot");
break;
case OpGroupNonUniformBallotBitExtract:
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupBallotBitExtract");
break;
case OpGroupNonUniformBallotFindLSB:
emit_unary_func_op(result_type, id, ops[3], "subgroupBallotFindLSB");
break;
case OpGroupNonUniformBallotFindMSB:
emit_unary_func_op(result_type, id, ops[3], "subgroupBallotFindMSB");
break;
case OpGroupNonUniformBallotBitCount:
{
auto operation = static_cast<GroupOperation>(ops[3]);
if (operation == GroupOperationReduce)
emit_unary_func_op(result_type, id, ops[4], "subgroupBallotBitCount");
else if (operation == GroupOperationInclusiveScan)
emit_unary_func_op(result_type, id, ops[4], "subgroupBallotInclusiveBitCount");
else if (operation == GroupOperationExclusiveScan)
emit_unary_func_op(result_type, id, ops[4], "subgroupBallotExclusiveBitCount");
else
SPIRV_CROSS_THROW("Invalid BitCount operation.");
break;
}
case OpGroupNonUniformShuffle:
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupShuffle");
break;
case OpGroupNonUniformShuffleXor:
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupShuffleXor");
break;
case OpGroupNonUniformShuffleUp:
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupShuffleUp");
break;
case OpGroupNonUniformShuffleDown:
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupShuffleDown");
break;
case OpGroupNonUniformAll:
emit_unary_func_op(result_type, id, ops[3], "subgroupAll");
break;
case OpGroupNonUniformAny:
emit_unary_func_op(result_type, id, ops[3], "subgroupAny");
break;
case OpGroupNonUniformAllEqual:
emit_unary_func_op(result_type, id, ops[3], "subgroupAllEqual");
break;
// clang-format off
#define GLSL_GROUP_OP(op, glsl_op) \
case OpGroupNonUniform##op: \
{ \
auto operation = static_cast<GroupOperation>(ops[3]); \
if (operation == GroupOperationReduce) \
emit_unary_func_op(result_type, id, ops[4], "subgroup" #glsl_op); \
else if (operation == GroupOperationInclusiveScan) \
emit_unary_func_op(result_type, id, ops[4], "subgroupInclusive" #glsl_op); \
else if (operation == GroupOperationExclusiveScan) \
emit_unary_func_op(result_type, id, ops[4], "subgroupExclusive" #glsl_op); \
else if (operation == GroupOperationClusteredReduce) \
emit_binary_func_op(result_type, id, ops[4], ops[5], "subgroupClustered" #glsl_op); \
else \
SPIRV_CROSS_THROW("Invalid group operation."); \
break; \
}
GLSL_GROUP_OP(FAdd, Add)
GLSL_GROUP_OP(FMul, Mul)
GLSL_GROUP_OP(FMin, Min)
GLSL_GROUP_OP(FMax, Max)
GLSL_GROUP_OP(IAdd, Add)
GLSL_GROUP_OP(IMul, Mul)
GLSL_GROUP_OP(SMin, Min)
GLSL_GROUP_OP(SMax, Max)
GLSL_GROUP_OP(UMin, Min)
GLSL_GROUP_OP(UMax, Max)
GLSL_GROUP_OP(BitwiseAnd, And)
GLSL_GROUP_OP(BitwiseOr, Or)
GLSL_GROUP_OP(BitwiseXor, Xor)
#undef GLSL_GROUP_OP
// clang-format on
case OpGroupNonUniformQuadSwap:
{
uint32_t direction = get<SPIRConstant>(ops[4]).scalar();
if (direction == 0)
emit_unary_func_op(result_type, id, ops[3], "subgroupQuadSwapHorizontal");
else if (direction == 1)
emit_unary_func_op(result_type, id, ops[3], "subgroupQuadSwapVertical");
else if (direction == 2)
emit_unary_func_op(result_type, id, ops[3], "subgroupQuadSwapDiagonal");
else
SPIRV_CROSS_THROW("Invalid quad swap direction.");
break;
}
case OpGroupNonUniformQuadBroadcast:
{
emit_binary_func_op(result_type, id, ops[3], ops[4], "subgroupQuadBroadcast");
break;
}
default:
SPIRV_CROSS_THROW("Invalid opcode for subgroup.");
}
register_control_dependent_expression(id);
}
string CompilerGLSL::bitcast_glsl_op(const SPIRType &out_type, const SPIRType &in_type)
{
// OpBitcast can deal with pointers.
if (out_type.pointer || in_type.pointer)
return type_to_glsl(out_type);
if (out_type.basetype == in_type.basetype)
return "";
assert(out_type.basetype != SPIRType::Boolean);
assert(in_type.basetype != SPIRType::Boolean);
bool integral_cast = type_is_integral(out_type) && type_is_integral(in_type);
bool same_size_cast = out_type.width == in_type.width;
// Trivial bitcast case, casts between integers.
if (integral_cast && same_size_cast)
return type_to_glsl(out_type);
// Catch-all 8-bit arithmetic casts (GL_EXT_shader_explicit_arithmetic_types).
if (out_type.width == 8 && in_type.width >= 16 && integral_cast && in_type.vecsize == 1)
return "unpack8";
else if (in_type.width == 8 && out_type.width == 16 && integral_cast && out_type.vecsize == 1)
return "pack16";
else if (in_type.width == 8 && out_type.width == 32 && integral_cast && out_type.vecsize == 1)
return "pack32";
// Floating <-> Integer special casts. Just have to enumerate all cases. :(
// 16-bit, 32-bit and 64-bit floats.
if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Float)
{
if (is_legacy_es())
SPIRV_CROSS_THROW("Float -> Uint bitcast not supported on legacy ESSL.");
else if (!options.es && options.version < 330)
require_extension_internal("GL_ARB_shader_bit_encoding");
return "floatBitsToUint";
}
else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::Float)
{
if (is_legacy_es())
SPIRV_CROSS_THROW("Float -> Int bitcast not supported on legacy ESSL.");
else if (!options.es && options.version < 330)
require_extension_internal("GL_ARB_shader_bit_encoding");
return "floatBitsToInt";
}
else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::UInt)
{
if (is_legacy_es())
SPIRV_CROSS_THROW("Uint -> Float bitcast not supported on legacy ESSL.");
else if (!options.es && options.version < 330)
require_extension_internal("GL_ARB_shader_bit_encoding");
return "uintBitsToFloat";
}
else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::Int)
{
if (is_legacy_es())
SPIRV_CROSS_THROW("Int -> Float bitcast not supported on legacy ESSL.");
else if (!options.es && options.version < 330)
require_extension_internal("GL_ARB_shader_bit_encoding");
return "intBitsToFloat";
}
else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::Double)
return "doubleBitsToInt64";
else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Double)
return "doubleBitsToUint64";
else if (out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::Int64)
return "int64BitsToDouble";
else if (out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::UInt64)
return "uint64BitsToDouble";
else if (out_type.basetype == SPIRType::Short && in_type.basetype == SPIRType::Half)
return "float16BitsToInt16";
else if (out_type.basetype == SPIRType::UShort && in_type.basetype == SPIRType::Half)
return "float16BitsToUint16";
else if (out_type.basetype == SPIRType::Half && in_type.basetype == SPIRType::Short)
return "int16BitsToFloat16";
else if (out_type.basetype == SPIRType::Half && in_type.basetype == SPIRType::UShort)
return "uint16BitsToFloat16";
// And finally, some even more special purpose casts.
if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::UInt && in_type.vecsize == 2)
return "packUint2x32";
else if (out_type.basetype == SPIRType::Half && in_type.basetype == SPIRType::UInt && in_type.vecsize == 1)
return "unpackFloat2x16";
else if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Half && in_type.vecsize == 2)
return "packFloat2x16";
else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::Short && in_type.vecsize == 2)
return "packInt2x16";
else if (out_type.basetype == SPIRType::Short && in_type.basetype == SPIRType::Int && in_type.vecsize == 1)
return "unpackInt2x16";
else if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::UShort && in_type.vecsize == 2)
return "packUint2x16";
else if (out_type.basetype == SPIRType::UShort && in_type.basetype == SPIRType::UInt && in_type.vecsize == 1)
return "unpackUint2x16";
else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::Short && in_type.vecsize == 4)
return "packInt4x16";
else if (out_type.basetype == SPIRType::Short && in_type.basetype == SPIRType::Int64 && in_type.vecsize == 1)
return "unpackInt4x16";
else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::UShort && in_type.vecsize == 4)
return "packUint4x16";
else if (out_type.basetype == SPIRType::UShort && in_type.basetype == SPIRType::UInt64 && in_type.vecsize == 1)
return "unpackUint4x16";
return "";
}
string CompilerGLSL::bitcast_glsl(const SPIRType &result_type, uint32_t argument)
{
auto op = bitcast_glsl_op(result_type, expression_type(argument));
if (op.empty())
return to_enclosed_unpacked_expression(argument);
else
return join(op, "(", to_unpacked_expression(argument), ")");
}
std::string CompilerGLSL::bitcast_expression(SPIRType::BaseType target_type, uint32_t arg)
{
auto expr = to_expression(arg);
auto &src_type = expression_type(arg);
if (src_type.basetype != target_type)
{
auto target = src_type;
target.basetype = target_type;
expr = join(bitcast_glsl_op(target, src_type), "(", expr, ")");
}
return expr;
}
std::string CompilerGLSL::bitcast_expression(const SPIRType &target_type, SPIRType::BaseType expr_type,
const std::string &expr)
{
if (target_type.basetype == expr_type)
return expr;
auto src_type = target_type;
src_type.basetype = expr_type;
return join(bitcast_glsl_op(target_type, src_type), "(", expr, ")");
}
string CompilerGLSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
{
switch (builtin)
{
case BuiltInPosition:
return "gl_Position";
case BuiltInPointSize:
return "gl_PointSize";
case BuiltInClipDistance:
return "gl_ClipDistance";
case BuiltInCullDistance:
return "gl_CullDistance";
case BuiltInVertexId:
if (options.vulkan_semantics)
SPIRV_CROSS_THROW(
"Cannot implement gl_VertexID in Vulkan GLSL. This shader was created with GL semantics.");
return "gl_VertexID";
case BuiltInInstanceId:
if (options.vulkan_semantics)
SPIRV_CROSS_THROW(
"Cannot implement gl_InstanceID in Vulkan GLSL. This shader was created with GL semantics.");
return "gl_InstanceID";
case BuiltInVertexIndex:
if (options.vulkan_semantics)
return "gl_VertexIndex";
else
return "gl_VertexID"; // gl_VertexID already has the base offset applied.
case BuiltInInstanceIndex:
if (options.vulkan_semantics)
return "gl_InstanceIndex";
else if (options.vertex.support_nonzero_base_instance)
return "(gl_InstanceID + SPIRV_Cross_BaseInstance)"; // ... but not gl_InstanceID.
else
return "gl_InstanceID";
case BuiltInPrimitiveId:
if (storage == StorageClassInput && get_entry_point().model == ExecutionModelGeometry)
return "gl_PrimitiveIDIn";
else
return "gl_PrimitiveID";
case BuiltInInvocationId:
return "gl_InvocationID";
case BuiltInLayer:
return "gl_Layer";
case BuiltInViewportIndex:
return "gl_ViewportIndex";
case BuiltInTessLevelOuter:
return "gl_TessLevelOuter";
case BuiltInTessLevelInner:
return "gl_TessLevelInner";
case BuiltInTessCoord:
return "gl_TessCoord";
case BuiltInFragCoord:
return "gl_FragCoord";
case BuiltInPointCoord:
return "gl_PointCoord";
case BuiltInFrontFacing:
return "gl_FrontFacing";
case BuiltInFragDepth:
return "gl_FragDepth";
case BuiltInNumWorkgroups:
return "gl_NumWorkGroups";
case BuiltInWorkgroupSize:
return "gl_WorkGroupSize";
case BuiltInWorkgroupId:
return "gl_WorkGroupID";
case BuiltInLocalInvocationId:
return "gl_LocalInvocationID";
case BuiltInGlobalInvocationId:
return "gl_GlobalInvocationID";
case BuiltInLocalInvocationIndex:
return "gl_LocalInvocationIndex";
case BuiltInHelperInvocation:
return "gl_HelperInvocation";
case BuiltInBaseVertex:
if (options.es)
SPIRV_CROSS_THROW("BaseVertex not supported in ES profile.");
if (options.version < 460)
{
require_extension_internal("GL_ARB_shader_draw_parameters");
return "gl_BaseVertexARB";
}
return "gl_BaseVertex";
case BuiltInBaseInstance:
if (options.es)
SPIRV_CROSS_THROW("BaseInstance not supported in ES profile.");
if (options.version < 460)
{
require_extension_internal("GL_ARB_shader_draw_parameters");
return "gl_BaseInstanceARB";
}
return "gl_BaseInstance";
case BuiltInDrawIndex:
if (options.es)
SPIRV_CROSS_THROW("DrawIndex not supported in ES profile.");
if (options.version < 460)
{
require_extension_internal("GL_ARB_shader_draw_parameters");
return "gl_DrawIDARB";
}
return "gl_DrawID";
case BuiltInSampleId:
if (options.es && options.version < 320)
require_extension_internal("GL_OES_sample_variables");
if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("gl_SampleID not supported before GLSL 400.");
return "gl_SampleID";
case BuiltInSampleMask:
if (options.es && options.version < 320)
require_extension_internal("GL_OES_sample_variables");
if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("gl_SampleMask/gl_SampleMaskIn not supported before GLSL 400.");
if (storage == StorageClassInput)
return "gl_SampleMaskIn";
else
return "gl_SampleMask";
case BuiltInSamplePosition:
if (options.es && options.version < 320)
require_extension_internal("GL_OES_sample_variables");
if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("gl_SamplePosition not supported before GLSL 400.");
return "gl_SamplePosition";
case BuiltInViewIndex:
if (options.vulkan_semantics)
{
require_extension_internal("GL_EXT_multiview");
return "gl_ViewIndex";
}
else
{
require_extension_internal("GL_OVR_multiview2");
return "gl_ViewID_OVR";
}
case BuiltInNumSubgroups:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_basic");
return "gl_NumSubgroups";
case BuiltInSubgroupId:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_basic");
return "gl_SubgroupID";
case BuiltInSubgroupSize:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_basic");
return "gl_SubgroupSize";
case BuiltInSubgroupLocalInvocationId:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_basic");
return "gl_SubgroupInvocationID";
case BuiltInSubgroupEqMask:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_ballot");
return "gl_SubgroupEqMask";
case BuiltInSubgroupGeMask:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_ballot");
return "gl_SubgroupGeMask";
case BuiltInSubgroupGtMask:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_ballot");
return "gl_SubgroupGtMask";
case BuiltInSubgroupLeMask:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_ballot");
return "gl_SubgroupLeMask";
case BuiltInSubgroupLtMask:
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Need Vulkan semantics for subgroup.");
require_extension_internal("GL_KHR_shader_subgroup_ballot");
return "gl_SubgroupLtMask";
case BuiltInLaunchIdNV:
return "gl_LaunchIDNV";
case BuiltInLaunchSizeNV:
return "gl_LaunchSizeNV";
case BuiltInWorldRayOriginNV:
return "gl_WorldRayOriginNV";
case BuiltInWorldRayDirectionNV:
return "gl_WorldRayDirectionNV";
case BuiltInObjectRayOriginNV:
return "gl_ObjectRayOriginNV";
case BuiltInObjectRayDirectionNV:
return "gl_ObjectRayDirectionNV";
case BuiltInRayTminNV:
return "gl_RayTminNV";
case BuiltInRayTmaxNV:
return "gl_RayTmaxNV";
case BuiltInInstanceCustomIndexNV:
return "gl_InstanceCustomIndexNV";
case BuiltInObjectToWorldNV:
return "gl_ObjectToWorldNV";
case BuiltInWorldToObjectNV:
return "gl_WorldToObjectNV";
case BuiltInHitTNV:
return "gl_HitTNV";
case BuiltInHitKindNV:
return "gl_HitKindNV";
case BuiltInIncomingRayFlagsNV:
return "gl_IncomingRayFlagsNV";
case BuiltInBaryCoordNV:
{
if (options.es && options.version < 320)
SPIRV_CROSS_THROW("gl_BaryCoordNV requires ESSL 320.");
else if (!options.es && options.version < 450)
SPIRV_CROSS_THROW("gl_BaryCoordNV requires GLSL 450.");
require_extension_internal("GL_NV_fragment_shader_barycentric");
return "gl_BaryCoordNV";
}
case BuiltInBaryCoordNoPerspNV:
{
if (options.es && options.version < 320)
SPIRV_CROSS_THROW("gl_BaryCoordNoPerspNV requires ESSL 320.");
else if (!options.es && options.version < 450)
SPIRV_CROSS_THROW("gl_BaryCoordNoPerspNV requires GLSL 450.");
require_extension_internal("GL_NV_fragment_shader_barycentric");
return "gl_BaryCoordNoPerspNV";
}
case BuiltInFragStencilRefEXT:
{
if (!options.es)
{
require_extension_internal("GL_ARB_shader_stencil_export");
return "gl_FragStencilRefARB";
}
else
SPIRV_CROSS_THROW("Stencil export not supported in GLES.");
}
default:
return join("gl_BuiltIn_", convert_to_string(builtin));
}
}
const char *CompilerGLSL::index_to_swizzle(uint32_t index)
{
switch (index)
{
case 0:
return "x";
case 1:
return "y";
case 2:
return "z";
case 3:
return "w";
default:
SPIRV_CROSS_THROW("Swizzle index out of range");
}
}
string CompilerGLSL::access_chain_internal(uint32_t base, const uint32_t *indices, uint32_t count,
AccessChainFlags flags, AccessChainMeta *meta)
{
string expr;
bool index_is_literal = (flags & ACCESS_CHAIN_INDEX_IS_LITERAL_BIT) != 0;
bool chain_only = (flags & ACCESS_CHAIN_CHAIN_ONLY_BIT) != 0;
bool ptr_chain = (flags & ACCESS_CHAIN_PTR_CHAIN_BIT) != 0;
bool register_expression_read = (flags & ACCESS_CHAIN_SKIP_REGISTER_EXPRESSION_READ_BIT) == 0;
if (!chain_only)
expr = to_enclosed_expression(base, register_expression_read);
// Start traversing type hierarchy at the proper non-pointer types,
// but keep type_id referencing the original pointer for use below.
uint32_t type_id = expression_type_id(base);
if (!backend.native_pointers)
{
if (ptr_chain)
SPIRV_CROSS_THROW("Backend does not support native pointers and does not support OpPtrAccessChain.");
// Wrapped buffer reference pointer types will need to poke into the internal "value" member before
// continuing the access chain.
if (should_dereference(base))
{
auto &type = get<SPIRType>(type_id);
expr = dereference_expression(type, expr);
}
}
const auto *type = &get_pointee_type(type_id);
bool access_chain_is_arrayed = expr.find_first_of('[') != string::npos;
bool row_major_matrix_needs_conversion = is_non_native_row_major_matrix(base);
bool is_packed = has_extended_decoration(base, SPIRVCrossDecorationPacked);
uint32_t packed_type = get_extended_decoration(base, SPIRVCrossDecorationPackedType);
bool is_invariant = has_decoration(base, DecorationInvariant);
bool pending_array_enclose = false;
bool dimension_flatten = false;
const auto append_index = [&](uint32_t index) {
expr += "[";
// If we are indexing into an array of SSBOs or UBOs, we need to index it with a non-uniform qualifier.
bool nonuniform_index =
has_decoration(index, DecorationNonUniformEXT) &&
(has_decoration(type->self, DecorationBlock) || has_decoration(type->self, DecorationBufferBlock));
if (nonuniform_index)
{
expr += backend.nonuniform_qualifier;
expr += "(";
}
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_expression(index, register_expression_read);
if (nonuniform_index)
expr += ")";
expr += "]";
};
for (uint32_t i = 0; i < count; i++)
{
uint32_t index = indices[i];
// Pointer chains
if (ptr_chain && i == 0)
{
// If we are flattening multidimensional arrays, only create opening bracket on first
// array index.
if (options.flatten_multidimensional_arrays)
{
dimension_flatten = type->array.size() >= 1;
pending_array_enclose = dimension_flatten;
if (pending_array_enclose)
expr += "[";
}
if (options.flatten_multidimensional_arrays && dimension_flatten)
{
// If we are flattening multidimensional arrays, do manual stride computation.
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_enclosed_expression(index, register_expression_read);
for (auto j = uint32_t(type->array.size()); j; j--)
{
expr += " * ";
expr += enclose_expression(to_array_size(*type, j - 1));
}
if (type->array.empty())
pending_array_enclose = false;
else
expr += " + ";
if (!pending_array_enclose)
expr += "]";
}
else
{
append_index(index);
}
if (type->basetype == SPIRType::ControlPointArray)
{
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
}
access_chain_is_arrayed = true;
}
// Arrays
else if (!type->array.empty())
{
// If we are flattening multidimensional arrays, only create opening bracket on first
// array index.
if (options.flatten_multidimensional_arrays && !pending_array_enclose)
{
dimension_flatten = type->array.size() > 1;
pending_array_enclose = dimension_flatten;
if (pending_array_enclose)
expr += "[";
}
assert(type->parent_type);
auto *var = maybe_get<SPIRVariable>(base);
if (backend.force_gl_in_out_block && i == 0 && var && is_builtin_variable(*var) &&
!has_decoration(type->self, DecorationBlock))
{
// This deals with scenarios for tesc/geom where arrays of gl_Position[] are declared.
// Normally, these variables live in blocks when compiled from GLSL,
// but HLSL seems to just emit straight arrays here.
// We must pretend this access goes through gl_in/gl_out arrays
// to be able to access certain builtins as arrays.
auto builtin = ir.meta[base].decoration.builtin_type;
switch (builtin)
{
// case BuiltInCullDistance: // These are already arrays, need to figure out rules for these in tess/geom.
// case BuiltInClipDistance:
case BuiltInPosition:
case BuiltInPointSize:
if (var->storage == StorageClassInput)
expr = join("gl_in[", to_expression(index, register_expression_read), "].", expr);
else if (var->storage == StorageClassOutput)
expr = join("gl_out[", to_expression(index, register_expression_read), "].", expr);
else
append_index(index);
break;
default:
append_index(index);
break;
}
}
else if (options.flatten_multidimensional_arrays && dimension_flatten)
{
// If we are flattening multidimensional arrays, do manual stride computation.
auto &parent_type = get<SPIRType>(type->parent_type);
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_enclosed_expression(index, register_expression_read);
for (auto j = uint32_t(parent_type.array.size()); j; j--)
{
expr += " * ";
expr += enclose_expression(to_array_size(parent_type, j - 1));
}
if (parent_type.array.empty())
pending_array_enclose = false;
else
expr += " + ";
if (!pending_array_enclose)
expr += "]";
}
else
{
append_index(index);
}
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
access_chain_is_arrayed = true;
}
// For structs, the index refers to a constant, which indexes into the members.
// We also check if this member is a builtin, since we then replace the entire expression with the builtin one.
else if (type->basetype == SPIRType::Struct)
{
if (!index_is_literal)
index = get<SPIRConstant>(index).scalar();
if (index >= type->member_types.size())
SPIRV_CROSS_THROW("Member index is out of bounds!");
BuiltIn builtin;
if (is_member_builtin(*type, index, &builtin))
{
// FIXME: We rely here on OpName on gl_in/gl_out to make this work properly.
// To make this properly work by omitting all OpName opcodes,
// we need to infer gl_in or gl_out based on the builtin, and stage.
if (access_chain_is_arrayed)
{
expr += ".";
expr += builtin_to_glsl(builtin, type->storage);
}
else
expr = builtin_to_glsl(builtin, type->storage);
}
else
{
// If the member has a qualified name, use it as the entire chain
string qual_mbr_name = get_member_qualified_name(type_id, index);
if (!qual_mbr_name.empty())
expr = qual_mbr_name;
else
expr += to_member_reference(base, *type, index, ptr_chain);
}
if (has_member_decoration(type->self, index, DecorationInvariant))
is_invariant = true;
is_packed = member_is_packed_type(*type, index);
if (is_packed)
packed_type = get_extended_member_decoration(type->self, index, SPIRVCrossDecorationPackedType);
else
packed_type = 0;
row_major_matrix_needs_conversion = member_is_non_native_row_major_matrix(*type, index);
type = &get<SPIRType>(type->member_types[index]);
}
// Matrix -> Vector
else if (type->columns > 1)
{
if (row_major_matrix_needs_conversion)
{
expr = convert_row_major_matrix(expr, *type, is_packed);
row_major_matrix_needs_conversion = false;
is_packed = false;
packed_type = 0;
}
expr += "[";
if (index_is_literal)
expr += convert_to_string(index);
else
expr += to_expression(index, register_expression_read);
expr += "]";
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
}
// Vector -> Scalar
else if (type->vecsize > 1)
{
if (index_is_literal && !is_packed)
{
expr += ".";
expr += index_to_swizzle(index);
}
else if (ir.ids[index].get_type() == TypeConstant && !is_packed)
{
auto &c = get<SPIRConstant>(index);
expr += ".";
expr += index_to_swizzle(c.scalar());
}
else if (index_is_literal)
{
// For packed vectors, we can only access them as an array, not by swizzle.
expr += join("[", index, "]");
}
else
{
expr += "[";
expr += to_expression(index, register_expression_read);
expr += "]";
}
is_packed = false;
packed_type = 0;
type_id = type->parent_type;
type = &get<SPIRType>(type_id);
}
else if (!backend.allow_truncated_access_chain)
SPIRV_CROSS_THROW("Cannot subdivide a scalar value!");
}
if (pending_array_enclose)
{
SPIRV_CROSS_THROW("Flattening of multidimensional arrays were enabled, "
"but the access chain was terminated in the middle of a multidimensional array. "
"This is not supported.");
}
if (meta)
{
meta->need_transpose = row_major_matrix_needs_conversion;
meta->storage_is_packed = is_packed;
meta->storage_is_invariant = is_invariant;
meta->storage_packed_type = packed_type;
}
return expr;
}
string CompilerGLSL::to_flattened_struct_member(const SPIRVariable &var, uint32_t index)
{
auto &type = get<SPIRType>(var.basetype);
return sanitize_underscores(join(to_name(var.self), "_", to_member_name(type, index)));
}
string CompilerGLSL::access_chain(uint32_t base, const uint32_t *indices, uint32_t count, const SPIRType &target_type,
AccessChainMeta *meta, bool ptr_chain)
{
if (flattened_buffer_blocks.count(base))
{
uint32_t matrix_stride = 0;
bool need_transpose = false;
flattened_access_chain_offset(expression_type(base), indices, count, 0, 16, &need_transpose, &matrix_stride,
ptr_chain);
if (meta)
{
meta->need_transpose = target_type.columns > 1 && need_transpose;
meta->storage_is_packed = false;
}
return flattened_access_chain(base, indices, count, target_type, 0, matrix_stride, need_transpose);
}
else if (flattened_structs.count(base) && count > 0)
{
AccessChainFlags flags = ACCESS_CHAIN_CHAIN_ONLY_BIT | ACCESS_CHAIN_SKIP_REGISTER_EXPRESSION_READ_BIT;
if (ptr_chain)
flags |= ACCESS_CHAIN_PTR_CHAIN_BIT;
auto chain = access_chain_internal(base, indices, count, flags, nullptr).substr(1);
if (meta)
{
meta->need_transpose = false;
meta->storage_is_packed = false;
}
return sanitize_underscores(join(to_name(base), "_", chain));
}
else
{
AccessChainFlags flags = ACCESS_CHAIN_SKIP_REGISTER_EXPRESSION_READ_BIT;
if (ptr_chain)
flags |= ACCESS_CHAIN_PTR_CHAIN_BIT;
return access_chain_internal(base, indices, count, flags, meta);
}
}
string CompilerGLSL::load_flattened_struct(SPIRVariable &var)
{
auto expr = type_to_glsl_constructor(get<SPIRType>(var.basetype));
expr += '(';
auto &type = get<SPIRType>(var.basetype);
for (uint32_t i = 0; i < uint32_t(type.member_types.size()); i++)
{
if (i)
expr += ", ";
// Flatten the varyings.
// Apply name transformation for flattened I/O blocks.
expr += to_flattened_struct_member(var, i);
}
expr += ')';
return expr;
}
void CompilerGLSL::store_flattened_struct(SPIRVariable &var, uint32_t value)
{
// We're trying to store a structure which has been flattened.
// Need to copy members one by one.
auto rhs = to_expression(value);
// Store result locally.
// Since we're declaring a variable potentially multiple times here,
// store the variable in an isolated scope.
begin_scope();
statement(variable_decl_function_local(var), " = ", rhs, ";");
auto &type = get<SPIRType>(var.basetype);
for (uint32_t i = 0; i < uint32_t(type.member_types.size()); i++)
{
// Flatten the varyings.
// Apply name transformation for flattened I/O blocks.
auto lhs = sanitize_underscores(join(to_name(var.self), "_", to_member_name(type, i)));
rhs = join(to_name(var.self), ".", to_member_name(type, i));
statement(lhs, " = ", rhs, ";");
}
end_scope();
}
std::string CompilerGLSL::flattened_access_chain(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset, uint32_t matrix_stride,
bool need_transpose)
{
if (!target_type.array.empty())
SPIRV_CROSS_THROW("Access chains that result in an array can not be flattened");
else if (target_type.basetype == SPIRType::Struct)
return flattened_access_chain_struct(base, indices, count, target_type, offset);
else if (target_type.columns > 1)
return flattened_access_chain_matrix(base, indices, count, target_type, offset, matrix_stride, need_transpose);
else
return flattened_access_chain_vector(base, indices, count, target_type, offset, matrix_stride, need_transpose);
}
std::string CompilerGLSL::flattened_access_chain_struct(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset)
{
std::string expr;
expr += type_to_glsl_constructor(target_type);
expr += "(";
for (uint32_t i = 0; i < uint32_t(target_type.member_types.size()); ++i)
{
if (i != 0)
expr += ", ";
const SPIRType &member_type = get<SPIRType>(target_type.member_types[i]);
uint32_t member_offset = type_struct_member_offset(target_type, i);
// The access chain terminates at the struct, so we need to find matrix strides and row-major information
// ahead of time.
bool need_transpose = false;
uint32_t matrix_stride = 0;
if (member_type.columns > 1)
{
need_transpose = combined_decoration_for_member(target_type, i).get(DecorationRowMajor);
matrix_stride = type_struct_member_matrix_stride(target_type, i);
}
auto tmp = flattened_access_chain(base, indices, count, member_type, offset + member_offset, matrix_stride,
need_transpose);
// Cannot forward transpositions, so resolve them here.
if (need_transpose)
expr += convert_row_major_matrix(tmp, member_type, false);
else
expr += tmp;
}
expr += ")";
return expr;
}
std::string CompilerGLSL::flattened_access_chain_matrix(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset,
uint32_t matrix_stride, bool need_transpose)
{
assert(matrix_stride);
SPIRType tmp_type = target_type;
if (need_transpose)
swap(tmp_type.vecsize, tmp_type.columns);
std::string expr;
expr += type_to_glsl_constructor(tmp_type);
expr += "(";
for (uint32_t i = 0; i < tmp_type.columns; i++)
{
if (i != 0)
expr += ", ";
expr += flattened_access_chain_vector(base, indices, count, tmp_type, offset + i * matrix_stride, matrix_stride,
/* need_transpose= */ false);
}
expr += ")";
return expr;
}
std::string CompilerGLSL::flattened_access_chain_vector(uint32_t base, const uint32_t *indices, uint32_t count,
const SPIRType &target_type, uint32_t offset,
uint32_t matrix_stride, bool need_transpose)
{
auto result = flattened_access_chain_offset(expression_type(base), indices, count, offset, 16);
auto buffer_name = to_name(expression_type(base).self);
if (need_transpose)
{
std::string expr;
if (target_type.vecsize > 1)
{
expr += type_to_glsl_constructor(target_type);
expr += "(";
}
for (uint32_t i = 0; i < target_type.vecsize; ++i)
{
if (i != 0)
expr += ", ";
uint32_t component_offset = result.second + i * matrix_stride;
assert(component_offset % (target_type.width / 8) == 0);
uint32_t index = component_offset / (target_type.width / 8);
expr += buffer_name;
expr += "[";
expr += result.first; // this is a series of N1 * k1 + N2 * k2 + ... that is either empty or ends with a +
expr += convert_to_string(index / 4);
expr += "]";
expr += vector_swizzle(1, index % 4);
}
if (target_type.vecsize > 1)
{
expr += ")";
}
return expr;
}
else
{
assert(result.second % (target_type.width / 8) == 0);
uint32_t index = result.second / (target_type.width / 8);
std::string expr;
expr += buffer_name;
expr += "[";
expr += result.first; // this is a series of N1 * k1 + N2 * k2 + ... that is either empty or ends with a +
expr += convert_to_string(index / 4);
expr += "]";
expr += vector_swizzle(target_type.vecsize, index % 4);
return expr;
}
}
std::pair<std::string, uint32_t> CompilerGLSL::flattened_access_chain_offset(
const SPIRType &basetype, const uint32_t *indices, uint32_t count, uint32_t offset, uint32_t word_stride,
bool *need_transpose, uint32_t *out_matrix_stride, bool ptr_chain)
{
// Start traversing type hierarchy at the proper non-pointer types.
const auto *type = &get_pointee_type(basetype);
// This holds the type of the current pointer which we are traversing through.
// We always start out from a struct type which is the block.
// This is primarily used to reflect the array strides and matrix strides later.
// For the first access chain index, type_id won't be needed, so just keep it as 0, it will be set
// accordingly as members of structs are accessed.
assert(type->basetype == SPIRType::Struct);
uint32_t type_id = 0;
std::string expr;
// Inherit matrix information in case we are access chaining a vector which might have come from a row major layout.
bool row_major_matrix_needs_conversion = need_transpose ? *need_transpose : false;
uint32_t matrix_stride = out_matrix_stride ? *out_matrix_stride : 0;
for (uint32_t i = 0; i < count; i++)
{
uint32_t index = indices[i];
// Pointers
if (ptr_chain && i == 0)
{
// Here, the pointer type will be decorated with an array stride.
uint32_t array_stride = get_decoration(basetype.self, DecorationArrayStride);
if (!array_stride)
SPIRV_CROSS_THROW("SPIR-V does not define ArrayStride for buffer block.");
auto *constant = maybe_get<SPIRConstant>(index);
if (constant)
{
// Constant array access.
offset += constant->scalar() * array_stride;
}
else
{
// Dynamic array access.
if (array_stride % word_stride)
{
SPIRV_CROSS_THROW(
"Array stride for dynamic indexing must be divisible by the size of a 4-component vector. "
"Likely culprit here is a float or vec2 array inside a push constant block which is std430. "
"This cannot be flattened. Try using std140 layout instead.");
}
expr += to_enclosed_expression(index);
expr += " * ";
expr += convert_to_string(array_stride / word_stride);
expr += " + ";
}
// Type ID is unchanged.
}
// Arrays
else if (!type->array.empty())
{
// Here, the type_id will be a type ID for the array type itself.
uint32_t array_stride = get_decoration(type_id, DecorationArrayStride);
if (!array_stride)
SPIRV_CROSS_THROW("SPIR-V does not define ArrayStride for buffer block.");
auto *constant = maybe_get<SPIRConstant>(index);
if (constant)
{
// Constant array access.
offset += constant->scalar() * array_stride;
}
else
{
// Dynamic array access.
if (array_stride % word_stride)
{
SPIRV_CROSS_THROW(
"Array stride for dynamic indexing must be divisible by the size of a 4-component vector. "
"Likely culprit here is a float or vec2 array inside a push constant block which is std430. "
"This cannot be flattened. Try using std140 layout instead.");
}
expr += to_enclosed_expression(index, false);
expr += " * ";
expr += convert_to_string(array_stride / word_stride);
expr += " + ";
}
uint32_t parent_type = type->parent_type;
type = &get<SPIRType>(parent_type);
type_id = parent_type;
// Type ID now refers to the array type with one less dimension.
}
// For structs, the index refers to a constant, which indexes into the members.
// We also check if this member is a builtin, since we then replace the entire expression with the builtin one.
else if (type->basetype == SPIRType::Struct)
{
index = get<SPIRConstant>(index).scalar();
if (index >= type->member_types.size())
SPIRV_CROSS_THROW("Member index is out of bounds!");
offset += type_struct_member_offset(*type, index);
type_id = type->member_types[index];
auto &struct_type = *type;
type = &get<SPIRType>(type->member_types[index]);
if (type->columns > 1)
{
matrix_stride = type_struct_member_matrix_stride(struct_type, index);
row_major_matrix_needs_conversion =
combined_decoration_for_member(struct_type, index).get(DecorationRowMajor);
}
else
row_major_matrix_needs_conversion = false;
}
// Matrix -> Vector
else if (type->columns > 1)
{
auto *constant = maybe_get<SPIRConstant>(index);
if (constant)
{
index = get<SPIRConstant>(index).scalar();
offset += index * (row_major_matrix_needs_conversion ? (type->width / 8) : matrix_stride);
}
else
{
uint32_t indexing_stride = row_major_matrix_needs_conversion ? (type->width / 8) : matrix_stride;
// Dynamic array access.
if (indexing_stride % word_stride)
{
SPIRV_CROSS_THROW(
"Matrix stride for dynamic indexing must be divisible by the size of a 4-component vector. "
"Likely culprit here is a row-major matrix being accessed dynamically. "
"This cannot be flattened. Try using std140 layout instead.");
}
expr += to_enclosed_expression(index, false);
expr += " * ";
expr += convert_to_string(indexing_stride / word_stride);
expr += " + ";
}
uint32_t parent_type = type->parent_type;
type = &get<SPIRType>(type->parent_type);
type_id = parent_type;
}
// Vector -> Scalar
else if (type->vecsize > 1)
{
auto *constant = maybe_get<SPIRConstant>(index);
if (constant)
{
index = get<SPIRConstant>(index).scalar();
offset += index * (row_major_matrix_needs_conversion ? matrix_stride : (type->width / 8));
}
else
{
uint32_t indexing_stride = row_major_matrix_needs_conversion ? matrix_stride : (type->width / 8);
// Dynamic array access.
if (indexing_stride % word_stride)
{
SPIRV_CROSS_THROW(
"Stride for dynamic vector indexing must be divisible by the size of a 4-component vector. "
"This cannot be flattened in legacy targets.");
}
expr += to_enclosed_expression(index, false);
expr += " * ";
expr += convert_to_string(indexing_stride / word_stride);
expr += " + ";
}
uint32_t parent_type = type->parent_type;
type = &get<SPIRType>(type->parent_type);
type_id = parent_type;
}
else
SPIRV_CROSS_THROW("Cannot subdivide a scalar value!");
}
if (need_transpose)
*need_transpose = row_major_matrix_needs_conversion;
if (out_matrix_stride)
*out_matrix_stride = matrix_stride;
return std::make_pair(expr, offset);
}
bool CompilerGLSL::should_dereference(uint32_t id)
{
const auto &type = expression_type(id);
// Non-pointer expressions don't need to be dereferenced.
if (!type.pointer)
return false;
// Handles shouldn't be dereferenced either.
if (!expression_is_lvalue(id))
return false;
// If id is a variable but not a phi variable, we should not dereference it.
if (auto *var = maybe_get<SPIRVariable>(id))
return var->phi_variable;
// If id is an access chain, we should not dereference it.
if (auto *expr = maybe_get<SPIRExpression>(id))
return !expr->access_chain;
// Otherwise, we should dereference this pointer expression.
return true;
}
bool CompilerGLSL::should_forward(uint32_t id)
{
// If id is a variable we will try to forward it regardless of force_temporary check below
// This is important because otherwise we'll get local sampler copies (highp sampler2D foo = bar) that are invalid in OpenGL GLSL
auto *var = maybe_get<SPIRVariable>(id);
if (var && var->forwardable)
return true;
// For debugging emit temporary variables for all expressions
if (options.force_temporary)
return false;
// Immutable expression can always be forwarded.
if (is_immutable(id))
return true;
return false;
}
void CompilerGLSL::track_expression_read(uint32_t id)
{
switch (ir.ids[id].get_type())
{
case TypeExpression:
{
auto &e = get<SPIRExpression>(id);
for (auto implied_read : e.implied_read_expressions)
track_expression_read(implied_read);
break;
}
case TypeAccessChain:
{
auto &e = get<SPIRAccessChain>(id);
for (auto implied_read : e.implied_read_expressions)
track_expression_read(implied_read);
break;
}
default:
break;
}
// If we try to read a forwarded temporary more than once we will stamp out possibly complex code twice.
// In this case, it's better to just bind the complex expression to the temporary and read that temporary twice.
if (expression_is_forwarded(id))
{
auto &v = expression_usage_counts[id];
v++;
if (v >= 2)
{
//if (v == 2)
// fprintf(stderr, "ID %u was forced to temporary due to more than 1 expression use!\n", id);
forced_temporaries.insert(id);
// Force a recompile after this pass to avoid forwarding this variable.
force_recompile();
}
}
}
bool CompilerGLSL::args_will_forward(uint32_t id, const uint32_t *args, uint32_t num_args, bool pure)
{
if (forced_temporaries.find(id) != end(forced_temporaries))
return false;
for (uint32_t i = 0; i < num_args; i++)
if (!should_forward(args[i]))
return false;
// We need to forward globals as well.
if (!pure)
{
for (auto global : global_variables)
if (!should_forward(global))
return false;
for (auto aliased : aliased_variables)
if (!should_forward(aliased))
return false;
}
return true;
}
void CompilerGLSL::register_impure_function_call()
{
// Impure functions can modify globals and aliased variables, so invalidate them as well.
for (auto global : global_variables)
flush_dependees(get<SPIRVariable>(global));
for (auto aliased : aliased_variables)
flush_dependees(get<SPIRVariable>(aliased));
}
void CompilerGLSL::register_call_out_argument(uint32_t id)
{
register_write(id);
auto *var = maybe_get<SPIRVariable>(id);
if (var)
flush_variable_declaration(var->self);
}
string CompilerGLSL::variable_decl_function_local(SPIRVariable &var)
{
// These variables are always function local,
// so make sure we emit the variable without storage qualifiers.
// Some backends will inject custom variables locally in a function
// with a storage qualifier which is not function-local.
auto old_storage = var.storage;
var.storage = StorageClassFunction;
auto expr = variable_decl(var);
var.storage = old_storage;
return expr;
}
void CompilerGLSL::emit_variable_temporary_copies(const SPIRVariable &var)
{
if (var.allocate_temporary_copy)
{
auto &type = get<SPIRType>(var.basetype);
auto &flags = get_decoration_bitset(var.self);
statement(flags_to_qualifiers_glsl(type, flags), variable_decl(type, join("_", var.self, "_copy")), ";");
}
}
void CompilerGLSL::flush_variable_declaration(uint32_t id)
{
auto *var = maybe_get<SPIRVariable>(id);
if (var && var->deferred_declaration)
{
statement(variable_decl_function_local(*var), ";");
emit_variable_temporary_copies(*var);
var->deferred_declaration = false;
}
}
bool CompilerGLSL::remove_duplicate_swizzle(string &op)
{
auto pos = op.find_last_of('.');
if (pos == string::npos || pos == 0)
return false;
string final_swiz = op.substr(pos + 1, string::npos);
if (backend.swizzle_is_function)
{
if (final_swiz.size() < 2)
return false;
if (final_swiz.substr(final_swiz.size() - 2, string::npos) == "()")
final_swiz.erase(final_swiz.size() - 2, string::npos);
else
return false;
}
// Check if final swizzle is of form .x, .xy, .xyz, .xyzw or similar.
// If so, and previous swizzle is of same length,
// we can drop the final swizzle altogether.
for (uint32_t i = 0; i < final_swiz.size(); i++)
{
static const char expected[] = { 'x', 'y', 'z', 'w' };
if (i >= 4 || final_swiz[i] != expected[i])
return false;
}
auto prevpos = op.find_last_of('.', pos - 1);
if (prevpos == string::npos)
return false;
prevpos++;
// Make sure there are only swizzles here ...
for (auto i = prevpos; i < pos; i++)
{
if (op[i] < 'w' || op[i] > 'z')
{
// If swizzles are foo.xyz() like in C++ backend for example, check for that.
if (backend.swizzle_is_function && i + 2 == pos && op[i] == '(' && op[i + 1] == ')')
break;
return false;
}
}
// If original swizzle is large enough, just carve out the components we need.
// E.g. foobar.wyx.xy will turn into foobar.wy.
if (pos - prevpos >= final_swiz.size())
{
op.erase(prevpos + final_swiz.size(), string::npos);
// Add back the function call ...
if (backend.swizzle_is_function)
op += "()";
}
return true;
}
// Optimizes away vector swizzles where we have something like
// vec3 foo;
// foo.xyz <-- swizzle expression does nothing.
// This is a very common pattern after OpCompositeCombine.
bool CompilerGLSL::remove_unity_swizzle(uint32_t base, string &op)
{
auto pos = op.find_last_of('.');
if (pos == string::npos || pos == 0)
return false;
string final_swiz = op.substr(pos + 1, string::npos);
if (backend.swizzle_is_function)
{
if (final_swiz.size() < 2)
return false;
if (final_swiz.substr(final_swiz.size() - 2, string::npos) == "()")
final_swiz.erase(final_swiz.size() - 2, string::npos);
else
return false;
}
// Check if final swizzle is of form .x, .xy, .xyz, .xyzw or similar.
// If so, and previous swizzle is of same length,
// we can drop the final swizzle altogether.
for (uint32_t i = 0; i < final_swiz.size(); i++)
{
static const char expected[] = { 'x', 'y', 'z', 'w' };
if (i >= 4 || final_swiz[i] != expected[i])
return false;
}
auto &type = expression_type(base);
// Sanity checking ...
assert(type.columns == 1 && type.array.empty());
if (type.vecsize == final_swiz.size())
op.erase(pos, string::npos);
return true;
}
string CompilerGLSL::build_composite_combiner(uint32_t return_type, const uint32_t *elems, uint32_t length)
{
uint32_t base = 0;
string op;
string subop;
// Can only merge swizzles for vectors.
auto &type = get<SPIRType>(return_type);
bool can_apply_swizzle_opt = type.basetype != SPIRType::Struct && type.array.empty() && type.columns == 1;
bool swizzle_optimization = false;
for (uint32_t i = 0; i < length; i++)
{
auto *e = maybe_get<SPIRExpression>(elems[i]);
// If we're merging another scalar which belongs to the same base
// object, just merge the swizzles to avoid triggering more than 1 expression read as much as possible!
if (can_apply_swizzle_opt && e && e->base_expression && e->base_expression == base)
{
// Only supposed to be used for vector swizzle -> scalar.
assert(!e->expression.empty() && e->expression.front() == '.');
subop += e->expression.substr(1, string::npos);
swizzle_optimization = true;
}
else
{
// We'll likely end up with duplicated swizzles, e.g.
// foobar.xyz.xyz from patterns like
// OpVectorShuffle
// OpCompositeExtract x 3
// OpCompositeConstruct 3x + other scalar.
// Just modify op in-place.
if (swizzle_optimization)
{
if (backend.swizzle_is_function)
subop += "()";
// Don't attempt to remove unity swizzling if we managed to remove duplicate swizzles.
// The base "foo" might be vec4, while foo.xyz is vec3 (OpVectorShuffle) and looks like a vec3 due to the .xyz tacked on.
// We only want to remove the swizzles if we're certain that the resulting base will be the same vecsize.
// Essentially, we can only remove one set of swizzles, since that's what we have control over ...
// Case 1:
// foo.yxz.xyz: Duplicate swizzle kicks in, giving foo.yxz, we are done.
// foo.yxz was the result of OpVectorShuffle and we don't know the type of foo.
// Case 2:
// foo.xyz: Duplicate swizzle won't kick in.
// If foo is vec3, we can remove xyz, giving just foo.
if (!remove_duplicate_swizzle(subop))
remove_unity_swizzle(base, subop);
// Strips away redundant parens if we created them during component extraction.
strip_enclosed_expression(subop);
swizzle_optimization = false;
op += subop;
}
else
op += subop;
if (i)
op += ", ";
subop = to_composite_constructor_expression(elems[i]);
}
base = e ? e->base_expression : 0;
}
if (swizzle_optimization)
{
if (backend.swizzle_is_function)
subop += "()";
if (!remove_duplicate_swizzle(subop))
remove_unity_swizzle(base, subop);
// Strips away redundant parens if we created them during component extraction.
strip_enclosed_expression(subop);
}
op += subop;
return op;
}
bool CompilerGLSL::skip_argument(uint32_t id) const
{
if (!combined_image_samplers.empty() || !options.vulkan_semantics)
{
auto &type = expression_type(id);
if (type.basetype == SPIRType::Sampler || (type.basetype == SPIRType::Image && type.image.sampled == 1))
return true;
}
return false;
}
bool CompilerGLSL::optimize_read_modify_write(const SPIRType &type, const string &lhs, const string &rhs)
{
// Do this with strings because we have a very clear pattern we can check for and it avoids
// adding lots of special cases to the code emission.
if (rhs.size() < lhs.size() + 3)
return false;
// Do not optimize matrices. They are a bit awkward to reason about in general
// (in which order does operation happen?), and it does not work on MSL anyways.
if (type.vecsize > 1 && type.columns > 1)
return false;
auto index = rhs.find(lhs);
if (index != 0)
return false;
// TODO: Shift operators, but it's not important for now.
auto op = rhs.find_first_of("+-/*%|&^", lhs.size() + 1);
if (op != lhs.size() + 1)
return false;
// Check that the op is followed by space. This excludes && and ||.
if (rhs[op + 1] != ' ')
return false;
char bop = rhs[op];
auto expr = rhs.substr(lhs.size() + 3);
// Try to find increments and decrements. Makes it look neater as += 1, -= 1 is fairly rare to see in real code.
// Find some common patterns which are equivalent.
if ((bop == '+' || bop == '-') && (expr == "1" || expr == "uint(1)" || expr == "1u" || expr == "int(1u)"))
statement(lhs, bop, bop, ";");
else
statement(lhs, " ", bop, "= ", expr, ";");
return true;
}
void CompilerGLSL::register_control_dependent_expression(uint32_t expr)
{
if (forwarded_temporaries.find(expr) == end(forwarded_temporaries))
return;
assert(current_emitting_block);
current_emitting_block->invalidate_expressions.push_back(expr);
}
void CompilerGLSL::emit_block_instructions(SPIRBlock &block)
{
current_emitting_block = █
for (auto &op : block.ops)
emit_instruction(op);
current_emitting_block = nullptr;
}
void CompilerGLSL::disallow_forwarding_in_expression_chain(const SPIRExpression &expr)
{
if (forwarded_temporaries.count(expr.self))
{
forced_temporaries.insert(expr.self);
force_recompile();
}
for (auto &dependent : expr.expression_dependencies)
disallow_forwarding_in_expression_chain(get<SPIRExpression>(dependent));
}
void CompilerGLSL::handle_store_to_invariant_variable(uint32_t store_id, uint32_t value_id)
{
// Variables or access chains marked invariant are complicated. We will need to make sure the code-gen leading up to
// this variable is consistent. The failure case for SPIRV-Cross is when an expression is forced to a temporary
// in one translation unit, but not another, e.g. due to multiple use of an expression.
// This causes variance despite the output variable being marked invariant, so the solution here is to force all dependent
// expressions to be temporaries.
// It is uncertain if this is enough to support invariant in all possible cases, but it should be good enough
// for all reasonable uses of invariant.
if (!has_decoration(store_id, DecorationInvariant))
return;
auto *expr = maybe_get<SPIRExpression>(value_id);
if (!expr)
return;
disallow_forwarding_in_expression_chain(*expr);
}
void CompilerGLSL::emit_store_statement(uint32_t lhs_expression, uint32_t rhs_expression)
{
auto rhs = to_pointer_expression(rhs_expression);
// Statements to OpStore may be empty if it is a struct with zero members. Just forward the store to /dev/null.
if (!rhs.empty())
{
handle_store_to_invariant_variable(lhs_expression, rhs_expression);
auto lhs = to_dereferenced_expression(lhs_expression);
// We might need to bitcast in order to store to a builtin.
bitcast_to_builtin_store(lhs_expression, rhs, expression_type(rhs_expression));
// Tries to optimize assignments like "<lhs> = <lhs> op expr".
// While this is purely cosmetic, this is important for legacy ESSL where loop
// variable increments must be in either i++ or i += const-expr.
// Without this, we end up with i = i + 1, which is correct GLSL, but not correct GLES 2.0.
if (!optimize_read_modify_write(expression_type(rhs_expression), lhs, rhs))
statement(lhs, " = ", rhs, ";");
register_write(lhs_expression);
}
}
uint32_t CompilerGLSL::get_integer_width_for_instruction(const Instruction &instr) const
{
if (instr.length < 3)
return 32;
auto *ops = stream(instr);
switch (instr.op)
{
case OpSConvert:
case OpConvertSToF:
case OpUConvert:
case OpConvertUToF:
case OpIEqual:
case OpINotEqual:
case OpSLessThan:
case OpSLessThanEqual:
case OpSGreaterThan:
case OpSGreaterThanEqual:
return expression_type(ops[2]).width;
default:
{
// We can look at result type which is more robust.
auto *type = maybe_get<SPIRType>(ops[0]);
if (type && type_is_integral(*type))
return type->width;
else
return 32;
}
}
}
uint32_t CompilerGLSL::get_integer_width_for_glsl_instruction(GLSLstd450 op, const uint32_t *ops, uint32_t length) const
{
if (length < 1)
return 32;
switch (op)
{
case GLSLstd450SAbs:
case GLSLstd450SSign:
case GLSLstd450UMin:
case GLSLstd450SMin:
case GLSLstd450UMax:
case GLSLstd450SMax:
case GLSLstd450UClamp:
case GLSLstd450SClamp:
case GLSLstd450FindSMsb:
case GLSLstd450FindUMsb:
return expression_type(ops[0]).width;
default:
{
// We don't need to care about other opcodes, just return 32.
return 32;
}
}
}
void CompilerGLSL::emit_instruction(const Instruction &instruction)
{
auto ops = stream(instruction);
auto opcode = static_cast<Op>(instruction.op);
uint32_t length = instruction.length;
#define GLSL_BOP(op) emit_binary_op(ops[0], ops[1], ops[2], ops[3], #op)
#define GLSL_BOP_CAST(op, type) \
emit_binary_op_cast(ops[0], ops[1], ops[2], ops[3], #op, type, opcode_is_sign_invariant(opcode))
#define GLSL_UOP(op) emit_unary_op(ops[0], ops[1], ops[2], #op)
#define GLSL_QFOP(op) emit_quaternary_func_op(ops[0], ops[1], ops[2], ops[3], ops[4], ops[5], #op)
#define GLSL_TFOP(op) emit_trinary_func_op(ops[0], ops[1], ops[2], ops[3], ops[4], #op)
#define GLSL_BFOP(op) emit_binary_func_op(ops[0], ops[1], ops[2], ops[3], #op)
#define GLSL_BFOP_CAST(op, type) \
emit_binary_func_op_cast(ops[0], ops[1], ops[2], ops[3], #op, type, opcode_is_sign_invariant(opcode))
#define GLSL_BFOP(op) emit_binary_func_op(ops[0], ops[1], ops[2], ops[3], #op)
#define GLSL_UFOP(op) emit_unary_func_op(ops[0], ops[1], ops[2], #op)
// If we need to do implicit bitcasts, make sure we do it with the correct type.
uint32_t integer_width = get_integer_width_for_instruction(instruction);
auto int_type = to_signed_basetype(integer_width);
auto uint_type = to_unsigned_basetype(integer_width);
switch (opcode)
{
// Dealing with memory
case OpLoad:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
flush_variable_declaration(ptr);
// If we're loading from memory that cannot be changed by the shader,
// just forward the expression directly to avoid needless temporaries.
// If an expression is mutable and forwardable, we speculate that it is immutable.
bool forward = should_forward(ptr) && forced_temporaries.find(id) == end(forced_temporaries);
// If loading a non-native row-major matrix, mark the expression as need_transpose.
bool need_transpose = false;
bool old_need_transpose = false;
auto *ptr_expression = maybe_get<SPIRExpression>(ptr);
if (ptr_expression && ptr_expression->need_transpose)
{
old_need_transpose = true;
ptr_expression->need_transpose = false;
need_transpose = true;
}
else if (is_non_native_row_major_matrix(ptr))
need_transpose = true;
// If we are forwarding this load,
// don't register the read to access chain here, defer that to when we actually use the expression,
// using the add_implied_read_expression mechanism.
auto expr = to_dereferenced_expression(ptr, !forward);
// We might need to bitcast in order to load from a builtin.
bitcast_from_builtin_load(ptr, expr, get<SPIRType>(result_type));
// We might be trying to load a gl_Position[N], where we should be
// doing float4[](gl_in[i].gl_Position, ...) instead.
// Similar workarounds are required for input arrays in tessellation.
unroll_array_from_complex_load(id, ptr, expr);
auto &type = get<SPIRType>(result_type);
// Shouldn't need to check for ID, but current glslang codegen requires it in some cases
// when loading Image/Sampler descriptors. It does not hurt to check ID as well.
if (has_decoration(id, DecorationNonUniformEXT) || has_decoration(ptr, DecorationNonUniformEXT))
{
propagate_nonuniform_qualifier(ptr);
convert_non_uniform_expression(type, expr);
}
if (ptr_expression)
ptr_expression->need_transpose = old_need_transpose;
// By default, suppress usage tracking since using same expression multiple times does not imply any extra work.
// However, if we try to load a complex, composite object from a flattened buffer,
// we should avoid emitting the same code over and over and lower the result to a temporary.
bool usage_tracking = ptr_expression && flattened_buffer_blocks.count(ptr_expression->loaded_from) != 0 &&
(type.basetype == SPIRType::Struct || (type.columns > 1));
SPIRExpression *e = nullptr;
if (!backend.array_is_value_type && !type.array.empty() && !forward)
{
// Complicated load case where we need to make a copy of ptr, but we cannot, because
// it is an array, and our backend does not support arrays as value types.
// Emit the temporary, and copy it explicitly.
e = &emit_uninitialized_temporary_expression(result_type, id);
emit_array_copy(to_expression(id), ptr);
}
else
e = &emit_op(result_type, id, expr, forward, !usage_tracking);
e->need_transpose = need_transpose;
register_read(id, ptr, forward);
// Pass through whether the result is of a packed type.
if (has_extended_decoration(ptr, SPIRVCrossDecorationPacked))
{
set_extended_decoration(id, SPIRVCrossDecorationPacked);
set_extended_decoration(id, SPIRVCrossDecorationPackedType,
get_extended_decoration(ptr, SPIRVCrossDecorationPackedType));
}
inherit_expression_dependencies(id, ptr);
if (forward)
add_implied_read_expression(*e, ptr);
break;
}
case OpInBoundsAccessChain:
case OpAccessChain:
case OpPtrAccessChain:
{
auto *var = maybe_get<SPIRVariable>(ops[2]);
if (var)
flush_variable_declaration(var->self);
// If the base is immutable, the access chain pointer must also be.
// If an expression is mutable and forwardable, we speculate that it is immutable.
AccessChainMeta meta;
bool ptr_chain = opcode == OpPtrAccessChain;
auto e = access_chain(ops[2], &ops[3], length - 3, get<SPIRType>(ops[0]), &meta, ptr_chain);
auto &expr = set<SPIRExpression>(ops[1], move(e), ops[0], should_forward(ops[2]));
auto *backing_variable = maybe_get_backing_variable(ops[2]);
expr.loaded_from = backing_variable ? backing_variable->self : ops[2];
expr.need_transpose = meta.need_transpose;
expr.access_chain = true;
// Mark the result as being packed. Some platforms handled packed vectors differently than non-packed.
if (meta.storage_is_packed)
set_extended_decoration(ops[1], SPIRVCrossDecorationPacked);
if (meta.storage_packed_type != 0)
set_extended_decoration(ops[1], SPIRVCrossDecorationPackedType, meta.storage_packed_type);
if (meta.storage_is_invariant)
set_decoration(ops[1], DecorationInvariant);
for (uint32_t i = 2; i < length; i++)
{
inherit_expression_dependencies(ops[1], ops[i]);
add_implied_read_expression(expr, ops[i]);
}
break;
}
case OpStore:
{
auto *var = maybe_get<SPIRVariable>(ops[0]);
if (has_decoration(ops[0], DecorationNonUniformEXT))
propagate_nonuniform_qualifier(ops[0]);
if (var && var->statically_assigned)
var->static_expression = ops[1];
else if (var && var->loop_variable && !var->loop_variable_enable)
var->static_expression = ops[1];
else if (var && var->remapped_variable)
{
// Skip the write.
}
else if (var && flattened_structs.count(ops[0]))
{
store_flattened_struct(*var, ops[1]);
register_write(ops[0]);
}
else
{
emit_store_statement(ops[0], ops[1]);
}
// Storing a pointer results in a variable pointer, so we must conservatively assume
// we can write through it.
if (expression_type(ops[1]).pointer)
register_write(ops[1]);
break;
}
case OpArrayLength:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto e = access_chain_internal(ops[2], &ops[3], length - 3, ACCESS_CHAIN_INDEX_IS_LITERAL_BIT, nullptr);
set<SPIRExpression>(id, join(type_to_glsl(get<SPIRType>(result_type)), "(", e, ".length())"), result_type,
true);
break;
}
// Function calls
case OpFunctionCall:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t func = ops[2];
const auto *arg = &ops[3];
length -= 3;
auto &callee = get<SPIRFunction>(func);
auto &return_type = get<SPIRType>(callee.return_type);
bool pure = function_is_pure(callee);
bool callee_has_out_variables = false;
bool emit_return_value_as_argument = false;
// Invalidate out variables passed to functions since they can be OpStore'd to.
for (uint32_t i = 0; i < length; i++)
{
if (callee.arguments[i].write_count)
{
register_call_out_argument(arg[i]);
callee_has_out_variables = true;
}
flush_variable_declaration(arg[i]);
}
if (!return_type.array.empty() && !backend.can_return_array)
{
callee_has_out_variables = true;
emit_return_value_as_argument = true;
}
if (!pure)
register_impure_function_call();
string funexpr;
SmallVector<string> arglist;
funexpr += to_name(func) + "(";
if (emit_return_value_as_argument)
{
statement(type_to_glsl(return_type), " ", to_name(id), type_to_array_glsl(return_type), ";");
arglist.push_back(to_name(id));
}
for (uint32_t i = 0; i < length; i++)
{
// Do not pass in separate images or samplers if we're remapping
// to combined image samplers.
if (skip_argument(arg[i]))
continue;
arglist.push_back(to_func_call_arg(arg[i]));
}
for (auto &combined : callee.combined_parameters)
{
uint32_t image_id = combined.global_image ? combined.image_id : arg[combined.image_id];
uint32_t sampler_id = combined.global_sampler ? combined.sampler_id : arg[combined.sampler_id];
arglist.push_back(to_combined_image_sampler(image_id, sampler_id));
}
append_global_func_args(callee, length, arglist);
funexpr += merge(arglist);
funexpr += ")";
// Check for function call constraints.
check_function_call_constraints(arg, length);
if (return_type.basetype != SPIRType::Void)
{
// If the function actually writes to an out variable,
// take the conservative route and do not forward.
// The problem is that we might not read the function
// result (and emit the function) before an out variable
// is read (common case when return value is ignored!
// In order to avoid start tracking invalid variables,
// just avoid the forwarding problem altogether.
bool forward = args_will_forward(id, arg, length, pure) && !callee_has_out_variables && pure &&
(forced_temporaries.find(id) == end(forced_temporaries));
if (emit_return_value_as_argument)
{
statement(funexpr, ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
}
else
emit_op(result_type, id, funexpr, forward);
// Function calls are implicit loads from all variables in question.
// Set dependencies for them.
for (uint32_t i = 0; i < length; i++)
register_read(id, arg[i], forward);
// If we're going to forward the temporary result,
// put dependencies on every variable that must not change.
if (forward)
register_global_read_dependencies(callee, id);
}
else
statement(funexpr, ";");
break;
}
// Composite munging
case OpCompositeConstruct:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
const auto *const elems = &ops[2];
length -= 2;
bool forward = true;
for (uint32_t i = 0; i < length; i++)
forward = forward && should_forward(elems[i]);
auto &out_type = get<SPIRType>(result_type);
auto *in_type = length > 0 ? &expression_type(elems[0]) : nullptr;
// Only splat if we have vector constructors.
// Arrays and structs must be initialized properly in full.
bool composite = !out_type.array.empty() || out_type.basetype == SPIRType::Struct;
bool splat = false;
bool swizzle_splat = false;
if (in_type)
{
splat = in_type->vecsize == 1 && in_type->columns == 1 && !composite && backend.use_constructor_splatting;
swizzle_splat = in_type->vecsize == 1 && in_type->columns == 1 && backend.can_swizzle_scalar;
if (ir.ids[elems[0]].get_type() == TypeConstant && !type_is_floating_point(*in_type))
{
// Cannot swizzle literal integers as a special case.
swizzle_splat = false;
}
}
if (splat || swizzle_splat)
{
uint32_t input = elems[0];
for (uint32_t i = 0; i < length; i++)
{
if (input != elems[i])
{
splat = false;
swizzle_splat = false;
}
}
}
if (out_type.basetype == SPIRType::Struct && !backend.can_declare_struct_inline)
forward = false;
if (!out_type.array.empty() && !backend.can_declare_arrays_inline)
forward = false;
if (type_is_empty(out_type) && !backend.supports_empty_struct)
forward = false;
string constructor_op;
if (backend.use_initializer_list && composite)
{
// Only use this path if we are building composites.
// This path cannot be used for arithmetic.
if (backend.use_typed_initializer_list && out_type.basetype == SPIRType::Struct && out_type.array.empty())
constructor_op += type_to_glsl_constructor(get<SPIRType>(result_type));
constructor_op += "{ ";
if (type_is_empty(out_type) && !backend.supports_empty_struct)
constructor_op += "0";
else if (splat)
constructor_op += to_expression(elems[0]);
else
constructor_op += build_composite_combiner(result_type, elems, length);
constructor_op += " }";
}
else if (swizzle_splat && !composite)
{
constructor_op = remap_swizzle(get<SPIRType>(result_type), 1, to_expression(elems[0]));
}
else
{
constructor_op = type_to_glsl_constructor(get<SPIRType>(result_type)) + "(";
if (type_is_empty(out_type) && !backend.supports_empty_struct)
constructor_op += "0";
else if (splat)
constructor_op += to_expression(elems[0]);
else
constructor_op += build_composite_combiner(result_type, elems, length);
constructor_op += ")";
}
if (!constructor_op.empty())
{
emit_op(result_type, id, constructor_op, forward);
for (uint32_t i = 0; i < length; i++)
inherit_expression_dependencies(id, elems[i]);
}
break;
}
case OpVectorInsertDynamic:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t vec = ops[2];
uint32_t comp = ops[3];
uint32_t index = ops[4];
flush_variable_declaration(vec);
// Make a copy, then use access chain to store the variable.
statement(declare_temporary(result_type, id), to_expression(vec), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
auto chain = access_chain_internal(id, &index, 1, 0, nullptr);
statement(chain, " = ", to_expression(comp), ";");
break;
}
case OpVectorExtractDynamic:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto expr = access_chain_internal(ops[2], &ops[3], 1, 0, nullptr);
emit_op(result_type, id, expr, should_forward(ops[2]));
inherit_expression_dependencies(id, ops[2]);
inherit_expression_dependencies(id, ops[3]);
break;
}
case OpCompositeExtract:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
length -= 3;
auto &type = get<SPIRType>(result_type);
// We can only split the expression here if our expression is forwarded as a temporary.
bool allow_base_expression = forced_temporaries.find(id) == end(forced_temporaries);
// Do not allow base expression for struct members. We risk doing "swizzle" optimizations in this case.
auto &composite_type = expression_type(ops[2]);
if (composite_type.basetype == SPIRType::Struct || !composite_type.array.empty())
allow_base_expression = false;
// Packed expressions cannot be split up.
if (has_extended_decoration(ops[2], SPIRVCrossDecorationPacked))
allow_base_expression = false;
AccessChainMeta meta;
SPIRExpression *e = nullptr;
// Only apply this optimization if result is scalar.
if (allow_base_expression && should_forward(ops[2]) && type.vecsize == 1 && type.columns == 1 && length == 1)
{
// We want to split the access chain from the base.
// This is so we can later combine different CompositeExtract results
// with CompositeConstruct without emitting code like
//
// vec3 temp = texture(...).xyz
// vec4(temp.x, temp.y, temp.z, 1.0).
//
// when we actually wanted to emit this
// vec4(texture(...).xyz, 1.0).
//
// Including the base will prevent this and would trigger multiple reads
// from expression causing it to be forced to an actual temporary in GLSL.
auto expr = access_chain_internal(ops[2], &ops[3], length,
ACCESS_CHAIN_INDEX_IS_LITERAL_BIT | ACCESS_CHAIN_CHAIN_ONLY_BIT, &meta);
e = &emit_op(result_type, id, expr, true, !expression_is_forwarded(ops[2]));
inherit_expression_dependencies(id, ops[2]);
e->base_expression = ops[2];
}
else
{
auto expr = access_chain_internal(ops[2], &ops[3], length, ACCESS_CHAIN_INDEX_IS_LITERAL_BIT, &meta);
e = &emit_op(result_type, id, expr, should_forward(ops[2]), !expression_is_forwarded(ops[2]));
inherit_expression_dependencies(id, ops[2]);
}
// Pass through some meta information to the loaded expression.
// We can still end up loading a buffer type to a variable, then CompositeExtract from it
// instead of loading everything through an access chain.
e->need_transpose = meta.need_transpose;
if (meta.storage_is_packed)
set_extended_decoration(id, SPIRVCrossDecorationPacked);
if (meta.storage_packed_type != 0)
set_extended_decoration(id, SPIRVCrossDecorationPackedType, meta.storage_packed_type);
if (meta.storage_is_invariant)
set_decoration(id, DecorationInvariant);
break;
}
case OpCompositeInsert:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t obj = ops[2];
uint32_t composite = ops[3];
const auto *elems = &ops[4];
length -= 4;
flush_variable_declaration(composite);
// Make a copy, then use access chain to store the variable.
statement(declare_temporary(result_type, id), to_expression(composite), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
auto chain = access_chain_internal(id, elems, length, ACCESS_CHAIN_INDEX_IS_LITERAL_BIT, nullptr);
statement(chain, " = ", to_expression(obj), ";");
break;
}
case OpCopyMemory:
{
uint32_t lhs = ops[0];
uint32_t rhs = ops[1];
if (lhs != rhs)
{
flush_variable_declaration(lhs);
flush_variable_declaration(rhs);
statement(to_expression(lhs), " = ", to_expression(rhs), ";");
register_write(lhs);
}
break;
}
case OpCopyObject:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t rhs = ops[2];
bool pointer = get<SPIRType>(result_type).pointer;
auto *chain = maybe_get<SPIRAccessChain>(rhs);
if (chain)
{
// Cannot lower to a SPIRExpression, just copy the object.
auto &e = set<SPIRAccessChain>(id, *chain);
e.self = id;
}
else if (expression_is_lvalue(rhs) && !pointer)
{
// Need a copy.
// For pointer types, we copy the pointer itself.
statement(declare_temporary(result_type, id), to_expression(rhs), ";");
set<SPIRExpression>(id, to_name(id), result_type, true);
inherit_expression_dependencies(id, rhs);
}
else
{
// RHS expression is immutable, so just forward it.
// Copying these things really make no sense, but
// seems to be allowed anyways.
auto &e = set<SPIRExpression>(id, to_expression(rhs), result_type, true);
if (pointer)
{
auto *var = maybe_get_backing_variable(rhs);
e.loaded_from = var ? var->self : 0;
}
// If we're copying an access chain, need to inherit the read expressions.
auto *rhs_expr = maybe_get<SPIRExpression>(rhs);
if (rhs_expr)
e.implied_read_expressions = rhs_expr->implied_read_expressions;
}
break;
}
case OpVectorShuffle:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t vec0 = ops[2];
uint32_t vec1 = ops[3];
const auto *elems = &ops[4];
length -= 4;
auto &type0 = expression_type(vec0);
// If we have the undefined swizzle index -1, we need to swizzle in undefined data,
// or in our case, T(0).
bool shuffle = false;
for (uint32_t i = 0; i < length; i++)
if (elems[i] >= type0.vecsize || elems[i] == 0xffffffffu)
shuffle = true;
// Cannot use swizzles with packed expressions, force shuffle path.
if (!shuffle && has_extended_decoration(vec0, SPIRVCrossDecorationPacked))
shuffle = true;
string expr;
bool should_fwd, trivial_forward;
if (shuffle)
{
should_fwd = should_forward(vec0) && should_forward(vec1);
trivial_forward = !expression_is_forwarded(vec0) && !expression_is_forwarded(vec1);
// Constructor style and shuffling from two different vectors.
SmallVector<string> args;
for (uint32_t i = 0; i < length; i++)
{
if (elems[i] == 0xffffffffu)
{
// Use a constant 0 here.
// We could use the first component or similar, but then we risk propagating
// a value we might not need, and bog down codegen.
SPIRConstant c;
c.constant_type = type0.parent_type;
assert(type0.parent_type != 0);
args.push_back(constant_expression(c));
}
else if (elems[i] >= type0.vecsize)
args.push_back(to_extract_component_expression(vec1, elems[i] - type0.vecsize));
else
args.push_back(to_extract_component_expression(vec0, elems[i]));
}
expr += join(type_to_glsl_constructor(get<SPIRType>(result_type)), "(", merge(args), ")");
}
else
{
should_fwd = should_forward(vec0);
trivial_forward = !expression_is_forwarded(vec0);
// We only source from first vector, so can use swizzle.
// If the vector is packed, unpack it before applying a swizzle (needed for MSL)
expr += to_enclosed_unpacked_expression(vec0);
expr += ".";
for (uint32_t i = 0; i < length; i++)
{
assert(elems[i] != 0xffffffffu);
expr += index_to_swizzle(elems[i]);
}
if (backend.swizzle_is_function && length > 1)
expr += "()";
}
// A shuffle is trivial in that it doesn't actually *do* anything.
// We inherit the forwardedness from our arguments to avoid flushing out to temporaries when it's not really needed.
emit_op(result_type, id, expr, should_fwd, trivial_forward);
inherit_expression_dependencies(id, vec0);
inherit_expression_dependencies(id, vec1);
break;
}
// ALU
case OpIsNan:
GLSL_UFOP(isnan);
break;
case OpIsInf:
GLSL_UFOP(isinf);
break;
case OpSNegate:
case OpFNegate:
GLSL_UOP(-);
break;
case OpIAdd:
{
// For simple arith ops, prefer the output type if there's a mismatch to avoid extra bitcasts.
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(+, type);
break;
}
case OpFAdd:
GLSL_BOP(+);
break;
case OpISub:
{
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(-, type);
break;
}
case OpFSub:
GLSL_BOP(-);
break;
case OpIMul:
{
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(*, type);
break;
}
case OpVectorTimesMatrix:
case OpMatrixTimesVector:
{
// If the matrix needs transpose, just flip the multiply order.
auto *e = maybe_get<SPIRExpression>(ops[opcode == OpMatrixTimesVector ? 2 : 3]);
if (e && e->need_transpose)
{
e->need_transpose = false;
emit_binary_op(ops[0], ops[1], ops[3], ops[2], "*");
e->need_transpose = true;
}
else
GLSL_BOP(*);
break;
}
case OpFMul:
case OpMatrixTimesScalar:
case OpVectorTimesScalar:
case OpMatrixTimesMatrix:
GLSL_BOP(*);
break;
case OpOuterProduct:
GLSL_BFOP(outerProduct);
break;
case OpDot:
GLSL_BFOP(dot);
break;
case OpTranspose:
GLSL_UFOP(transpose);
break;
case OpSRem:
{
uint32_t result_type = ops[0];
uint32_t result_id = ops[1];
uint32_t op0 = ops[2];
uint32_t op1 = ops[3];
// Needs special handling.
bool forward = should_forward(op0) && should_forward(op1);
auto expr = join(to_enclosed_expression(op0), " - ", to_enclosed_expression(op1), " * ", "(",
to_enclosed_expression(op0), " / ", to_enclosed_expression(op1), ")");
emit_op(result_type, result_id, expr, forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
break;
}
case OpSDiv:
GLSL_BOP_CAST(/, int_type);
break;
case OpUDiv:
GLSL_BOP_CAST(/, uint_type);
break;
case OpIAddCarry:
case OpISubBorrow:
{
if (options.es && options.version < 310)
SPIRV_CROSS_THROW("Extended arithmetic is only available from ESSL 310.");
else if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("Extended arithmetic is only available from GLSL 400.");
uint32_t result_type = ops[0];
uint32_t result_id = ops[1];
uint32_t op0 = ops[2];
uint32_t op1 = ops[3];
auto &type = get<SPIRType>(result_type);
emit_uninitialized_temporary_expression(result_type, result_id);
const char *op = opcode == OpIAddCarry ? "uaddCarry" : "usubBorrow";
statement(to_expression(result_id), ".", to_member_name(type, 0), " = ", op, "(", to_expression(op0), ", ",
to_expression(op1), ", ", to_expression(result_id), ".", to_member_name(type, 1), ");");
break;
}
case OpUMulExtended:
case OpSMulExtended:
{
if (options.es && options.version < 310)
SPIRV_CROSS_THROW("Extended arithmetic is only available from ESSL 310.");
else if (!options.es && options.version < 400)
SPIRV_CROSS_THROW("Extended arithmetic is only available from GLSL 4000.");
uint32_t result_type = ops[0];
uint32_t result_id = ops[1];
uint32_t op0 = ops[2];
uint32_t op1 = ops[3];
forced_temporaries.insert(result_id);
auto &type = get<SPIRType>(result_type);
emit_uninitialized_temporary_expression(result_type, result_id);
const char *op = opcode == OpUMulExtended ? "umulExtended" : "imulExtended";
statement(op, "(", to_expression(op0), ", ", to_expression(op1), ", ", to_expression(result_id), ".",
to_member_name(type, 1), ", ", to_expression(result_id), ".", to_member_name(type, 0), ");");
break;
}
case OpFDiv:
GLSL_BOP(/);
break;
case OpShiftRightLogical:
GLSL_BOP_CAST(>>, uint_type);
break;
case OpShiftRightArithmetic:
GLSL_BOP_CAST(>>, int_type);
break;
case OpShiftLeftLogical:
{
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(<<, type);
break;
}
case OpBitwiseOr:
{
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(|, type);
break;
}
case OpBitwiseXor:
{
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(^, type);
break;
}
case OpBitwiseAnd:
{
auto type = get<SPIRType>(ops[0]).basetype;
GLSL_BOP_CAST(&, type);
break;
}
case OpNot:
GLSL_UOP(~);
break;
case OpUMod:
GLSL_BOP_CAST(%, uint_type);
break;
case OpSMod:
GLSL_BOP_CAST(%, int_type);
break;
case OpFMod:
GLSL_BFOP(mod);
break;
case OpFRem:
{
if (is_legacy())
SPIRV_CROSS_THROW("OpFRem requires trunc() and is only supported on non-legacy targets. A workaround is "
"needed for legacy.");
uint32_t result_type = ops[0];
uint32_t result_id = ops[1];
uint32_t op0 = ops[2];
uint32_t op1 = ops[3];
// Needs special handling.
bool forward = should_forward(op0) && should_forward(op1);
auto expr = join(to_enclosed_expression(op0), " - ", to_enclosed_expression(op1), " * ", "trunc(",
to_enclosed_expression(op0), " / ", to_enclosed_expression(op1), ")");
emit_op(result_type, result_id, expr, forward);
inherit_expression_dependencies(result_id, op0);
inherit_expression_dependencies(result_id, op1);
break;
}
// Relational
case OpAny:
GLSL_UFOP(any);
break;
case OpAll:
GLSL_UFOP(all);
break;
case OpSelect:
emit_mix_op(ops[0], ops[1], ops[4], ops[3], ops[2]);
break;
case OpLogicalOr:
{
// No vector variant in GLSL for logical OR.
auto result_type = ops[0];
auto id = ops[1];
auto &type = get<SPIRType>(result_type);
if (type.vecsize > 1)
emit_unrolled_binary_op(result_type, id, ops[2], ops[3], "||");
else
GLSL_BOP(||);
break;
}
case OpLogicalAnd:
{
// No vector variant in GLSL for logical AND.
auto result_type = ops[0];
auto id = ops[1];
auto &type = get<SPIRType>(result_type);
if (type.vecsize > 1)
emit_unrolled_binary_op(result_type, id, ops[2], ops[3], "&&");
else
GLSL_BOP(&&);
break;
}
case OpLogicalNot:
{
auto &type = get<SPIRType>(ops[0]);
if (type.vecsize > 1)
GLSL_UFOP(not);
else
GLSL_UOP(!);
break;
}
case OpIEqual:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP_CAST(equal, int_type);
else
GLSL_BOP_CAST(==, int_type);
break;
}
case OpLogicalEqual:
case OpFOrdEqual:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP(equal);
else
GLSL_BOP(==);
break;
}
case OpINotEqual:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP_CAST(notEqual, int_type);
else
GLSL_BOP_CAST(!=, int_type);
break;
}
case OpLogicalNotEqual:
case OpFOrdNotEqual:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP(notEqual);
else
GLSL_BOP(!=);
break;
}
case OpUGreaterThan:
case OpSGreaterThan:
{
auto type = opcode == OpUGreaterThan ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP_CAST(greaterThan, type);
else
GLSL_BOP_CAST(>, type);
break;
}
case OpFOrdGreaterThan:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP(greaterThan);
else
GLSL_BOP(>);
break;
}
case OpUGreaterThanEqual:
case OpSGreaterThanEqual:
{
auto type = opcode == OpUGreaterThanEqual ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP_CAST(greaterThanEqual, type);
else
GLSL_BOP_CAST(>=, type);
break;
}
case OpFOrdGreaterThanEqual:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP(greaterThanEqual);
else
GLSL_BOP(>=);
break;
}
case OpULessThan:
case OpSLessThan:
{
auto type = opcode == OpULessThan ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP_CAST(lessThan, type);
else
GLSL_BOP_CAST(<, type);
break;
}
case OpFOrdLessThan:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP(lessThan);
else
GLSL_BOP(<);
break;
}
case OpULessThanEqual:
case OpSLessThanEqual:
{
auto type = opcode == OpULessThanEqual ? SPIRType::UInt : SPIRType::Int;
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP_CAST(lessThanEqual, type);
else
GLSL_BOP_CAST(<=, type);
break;
}
case OpFOrdLessThanEqual:
{
if (expression_type(ops[2]).vecsize > 1)
GLSL_BFOP(lessThanEqual);
else
GLSL_BOP(<=);
break;
}
// Conversion
case OpSConvert:
case OpConvertSToF:
case OpUConvert:
case OpConvertUToF:
{
auto input_type = opcode == OpSConvert || opcode == OpConvertSToF ? int_type : uint_type;
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto &type = get<SPIRType>(result_type);
auto &arg_type = expression_type(ops[2]);
auto func = type_to_glsl_constructor(type);
// If we're sign-extending or zero-extending, we need to make sure we cast from the correct type.
// For truncation, it does not matter, so don't emit useless casts.
if (arg_type.width < type.width)
emit_unary_func_op_cast(result_type, id, ops[2], func.c_str(), input_type, type.basetype);
else
emit_unary_func_op(result_type, id, ops[2], func.c_str());
break;
}
case OpConvertFToU:
case OpConvertFToS:
{
// Cast to expected arithmetic type, then potentially bitcast away to desired signedness.
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto &type = get<SPIRType>(result_type);
auto expected_type = type;
auto &float_type = expression_type(ops[2]);
expected_type.basetype =
opcode == OpConvertFToS ? to_signed_basetype(type.width) : to_unsigned_basetype(type.width);
auto func = type_to_glsl_constructor(expected_type);
emit_unary_func_op_cast(result_type, id, ops[2], func.c_str(), float_type.basetype, expected_type.basetype);
break;
}
case OpFConvert:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto func = type_to_glsl_constructor(get<SPIRType>(result_type));
emit_unary_func_op(result_type, id, ops[2], func.c_str());
break;
}
case OpBitcast:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t arg = ops[2];
auto op = bitcast_glsl_op(get<SPIRType>(result_type), expression_type(arg));
emit_unary_func_op(result_type, id, arg, op.c_str());
break;
}
case OpQuantizeToF16:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t arg = ops[2];
string op;
auto &type = get<SPIRType>(result_type);
switch (type.vecsize)
{
case 1:
op = join("unpackHalf2x16(packHalf2x16(vec2(", to_expression(arg), "))).x");
break;
case 2:
op = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), "))");
break;
case 3:
{
auto op0 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".xy))");
auto op1 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".zz)).x");
op = join("vec3(", op0, ", ", op1, ")");
break;
}
case 4:
{
auto op0 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".xy))");
auto op1 = join("unpackHalf2x16(packHalf2x16(", to_expression(arg), ".zw))");
op = join("vec4(", op0, ", ", op1, ")");
break;
}
default:
SPIRV_CROSS_THROW("Illegal argument to OpQuantizeToF16.");
}
emit_op(result_type, id, op, should_forward(arg));
inherit_expression_dependencies(id, arg);
break;
}
// Derivatives
case OpDPdx:
GLSL_UFOP(dFdx);
if (is_legacy_es())
require_extension_internal("GL_OES_standard_derivatives");
register_control_dependent_expression(ops[1]);
break;
case OpDPdy:
GLSL_UFOP(dFdy);
if (is_legacy_es())
require_extension_internal("GL_OES_standard_derivatives");
register_control_dependent_expression(ops[1]);
break;
case OpDPdxFine:
GLSL_UFOP(dFdxFine);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension_internal("GL_ARB_derivative_control");
register_control_dependent_expression(ops[1]);
break;
case OpDPdyFine:
GLSL_UFOP(dFdyFine);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension_internal("GL_ARB_derivative_control");
register_control_dependent_expression(ops[1]);
break;
case OpDPdxCoarse:
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
GLSL_UFOP(dFdxCoarse);
if (options.version < 450)
require_extension_internal("GL_ARB_derivative_control");
register_control_dependent_expression(ops[1]);
break;
case OpDPdyCoarse:
GLSL_UFOP(dFdyCoarse);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension_internal("GL_ARB_derivative_control");
register_control_dependent_expression(ops[1]);
break;
case OpFwidth:
GLSL_UFOP(fwidth);
if (is_legacy_es())
require_extension_internal("GL_OES_standard_derivatives");
register_control_dependent_expression(ops[1]);
break;
case OpFwidthCoarse:
GLSL_UFOP(fwidthCoarse);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension_internal("GL_ARB_derivative_control");
register_control_dependent_expression(ops[1]);
break;
case OpFwidthFine:
GLSL_UFOP(fwidthFine);
if (options.es)
{
SPIRV_CROSS_THROW("GL_ARB_derivative_control is unavailable in OpenGL ES.");
}
if (options.version < 450)
require_extension_internal("GL_ARB_derivative_control");
register_control_dependent_expression(ops[1]);
break;
// Bitfield
case OpBitFieldInsert:
// TODO: The signedness of inputs is strict in GLSL, but not in SPIR-V, bitcast if necessary.
GLSL_QFOP(bitfieldInsert);
break;
case OpBitFieldSExtract:
case OpBitFieldUExtract:
// TODO: The signedness of inputs is strict in GLSL, but not in SPIR-V, bitcast if necessary.
GLSL_TFOP(bitfieldExtract);
break;
case OpBitReverse:
GLSL_UFOP(bitfieldReverse);
break;
case OpBitCount:
GLSL_UFOP(bitCount);
break;
// Atomics
case OpAtomicExchange:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
// Ignore semantics for now, probably only relevant to CL.
uint32_t val = ops[5];
const char *op = check_atomic_image(ptr) ? "imageAtomicExchange" : "atomicExchange";
forced_temporaries.insert(id);
emit_binary_func_op(result_type, id, ptr, val, op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicCompareExchange:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
uint32_t val = ops[6];
uint32_t comp = ops[7];
const char *op = check_atomic_image(ptr) ? "imageAtomicCompSwap" : "atomicCompSwap";
forced_temporaries.insert(id);
emit_trinary_func_op(result_type, id, ptr, comp, val, op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicLoad:
flush_all_atomic_capable_variables();
// FIXME: Image?
// OpAtomicLoad seems to only be relevant for atomic counters.
forced_temporaries.insert(ops[1]);
GLSL_UFOP(atomicCounter);
break;
case OpAtomicStore:
SPIRV_CROSS_THROW("Unsupported opcode OpAtomicStore.");
case OpAtomicIIncrement:
case OpAtomicIDecrement:
{
forced_temporaries.insert(ops[1]);
auto &type = expression_type(ops[2]);
if (type.storage == StorageClassAtomicCounter)
{
// Legacy GLSL stuff, not sure if this is relevant to support.
if (opcode == OpAtomicIIncrement)
GLSL_UFOP(atomicCounterIncrement);
else
GLSL_UFOP(atomicCounterDecrement);
}
else
{
bool atomic_image = check_atomic_image(ops[2]);
bool unsigned_type = (type.basetype == SPIRType::UInt) ||
(atomic_image && get<SPIRType>(type.image.type).basetype == SPIRType::UInt);
const char *op = atomic_image ? "imageAtomicAdd" : "atomicAdd";
const char *increment = nullptr;
if (opcode == OpAtomicIIncrement && unsigned_type)
increment = "1u";
else if (opcode == OpAtomicIIncrement)
increment = "1";
else if (unsigned_type)
increment = "uint(-1)";
else
increment = "-1";
emit_op(ops[0], ops[1], join(op, "(", to_expression(ops[2]), ", ", increment, ")"), false);
}
flush_all_atomic_capable_variables();
break;
}
case OpAtomicIAdd:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicAdd" : "atomicAdd";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicISub:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicAdd" : "atomicAdd";
forced_temporaries.insert(ops[1]);
auto expr = join(op, "(", to_expression(ops[2]), ", -", to_enclosed_expression(ops[5]), ")");
emit_op(ops[0], ops[1], expr, should_forward(ops[2]) && should_forward(ops[5]));
flush_all_atomic_capable_variables();
break;
}
case OpAtomicSMin:
case OpAtomicUMin:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicMin" : "atomicMin";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicSMax:
case OpAtomicUMax:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicMax" : "atomicMax";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicAnd:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicAnd" : "atomicAnd";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicOr:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicOr" : "atomicOr";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
break;
}
case OpAtomicXor:
{
const char *op = check_atomic_image(ops[2]) ? "imageAtomicXor" : "atomicXor";
forced_temporaries.insert(ops[1]);
emit_binary_func_op(ops[0], ops[1], ops[2], ops[5], op);
flush_all_atomic_capable_variables();
break;
}
// Geometry shaders
case OpEmitVertex:
statement("EmitVertex();");
break;
case OpEndPrimitive:
statement("EndPrimitive();");
break;
case OpEmitStreamVertex:
statement("EmitStreamVertex();");
break;
case OpEndStreamPrimitive:
statement("EndStreamPrimitive();");
break;
// Textures
case OpImageSampleExplicitLod:
case OpImageSampleProjExplicitLod:
case OpImageSampleDrefExplicitLod:
case OpImageSampleProjDrefExplicitLod:
case OpImageSampleImplicitLod:
case OpImageSampleProjImplicitLod:
case OpImageSampleDrefImplicitLod:
case OpImageSampleProjDrefImplicitLod:
case OpImageFetch:
case OpImageGather:
case OpImageDrefGather:
// Gets a bit hairy, so move this to a separate instruction.
emit_texture_op(instruction);
break;
case OpImage:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
// Suppress usage tracking.
auto &e = emit_op(result_type, id, to_expression(ops[2]), true, true);
// When using the image, we need to know which variable it is actually loaded from.
auto *var = maybe_get_backing_variable(ops[2]);
e.loaded_from = var ? var->self : 0;
break;
}
case OpImageQueryLod:
{
if (!options.es && options.version < 400)
{
require_extension_internal("GL_ARB_texture_query_lod");
// For some reason, the ARB spec is all-caps.
GLSL_BFOP(textureQueryLOD);
}
else if (options.es)
SPIRV_CROSS_THROW("textureQueryLod not supported in ES profile.");
else
GLSL_BFOP(textureQueryLod);
register_control_dependent_expression(ops[1]);
break;
}
case OpImageQueryLevels:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
if (!options.es && options.version < 430)
require_extension_internal("GL_ARB_texture_query_levels");
if (options.es)
SPIRV_CROSS_THROW("textureQueryLevels not supported in ES profile.");
auto expr = join("textureQueryLevels(", convert_separate_image_to_expression(ops[2]), ")");
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
break;
}
case OpImageQuerySamples:
{
auto &type = expression_type(ops[2]);
uint32_t result_type = ops[0];
uint32_t id = ops[1];
string expr;
if (type.image.sampled == 2)
expr = join("imageSamples(", to_expression(ops[2]), ")");
else
expr = join("textureSamples(", convert_separate_image_to_expression(ops[2]), ")");
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
break;
}
case OpSampledImage:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_sampled_image_op(result_type, id, ops[2], ops[3]);
inherit_expression_dependencies(id, ops[2]);
inherit_expression_dependencies(id, ops[3]);
break;
}
case OpImageQuerySizeLod:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto expr = join("textureSize(", convert_separate_image_to_expression(ops[2]), ", ",
bitcast_expression(SPIRType::Int, ops[3]), ")");
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
break;
}
// Image load/store
case OpImageRead:
{
// We added Nonreadable speculatively to the OpImage variable due to glslangValidator
// not adding the proper qualifiers.
// If it turns out we need to read the image after all, remove the qualifier and recompile.
auto *var = maybe_get_backing_variable(ops[2]);
if (var)
{
auto &flags = ir.meta[var->self].decoration.decoration_flags;
if (flags.get(DecorationNonReadable))
{
flags.clear(DecorationNonReadable);
force_recompile();
}
}
uint32_t result_type = ops[0];
uint32_t id = ops[1];
bool pure;
string imgexpr;
auto &type = expression_type(ops[2]);
if (var && var->remapped_variable) // Remapped input, just read as-is without any op-code
{
if (type.image.ms)
SPIRV_CROSS_THROW("Trying to remap multisampled image to variable, this is not possible.");
auto itr =
find_if(begin(pls_inputs), end(pls_inputs), [var](const PlsRemap &pls) { return pls.id == var->self; });
if (itr == end(pls_inputs))
{
// For non-PLS inputs, we rely on subpass type remapping information to get it right
// since ImageRead always returns 4-component vectors and the backing type is opaque.
if (!var->remapped_components)
SPIRV_CROSS_THROW("subpassInput was remapped, but remap_components is not set correctly.");
imgexpr = remap_swizzle(get<SPIRType>(result_type), var->remapped_components, to_expression(ops[2]));
}
else
{
// PLS input could have different number of components than what the SPIR expects, swizzle to
// the appropriate vector size.
uint32_t components = pls_format_to_components(itr->format);
imgexpr = remap_swizzle(get<SPIRType>(result_type), components, to_expression(ops[2]));
}
pure = true;
}
else if (type.image.dim == DimSubpassData)
{
if (options.vulkan_semantics)
{
// With Vulkan semantics, use the proper Vulkan GLSL construct.
if (type.image.ms)
{
uint32_t operands = ops[4];
if (operands != ImageOperandsSampleMask || length != 6)
SPIRV_CROSS_THROW(
"Multisampled image used in OpImageRead, but unexpected operand mask was used.");
uint32_t samples = ops[5];
imgexpr = join("subpassLoad(", to_expression(ops[2]), ", ", to_expression(samples), ")");
}
else
imgexpr = join("subpassLoad(", to_expression(ops[2]), ")");
}
else
{
if (type.image.ms)
{
uint32_t operands = ops[4];
if (operands != ImageOperandsSampleMask || length != 6)
SPIRV_CROSS_THROW(
"Multisampled image used in OpImageRead, but unexpected operand mask was used.");
uint32_t samples = ops[5];
imgexpr = join("texelFetch(", to_expression(ops[2]), ", ivec2(gl_FragCoord.xy), ",
to_expression(samples), ")");
}
else
{
// Implement subpass loads via texture barrier style sampling.
imgexpr = join("texelFetch(", to_expression(ops[2]), ", ivec2(gl_FragCoord.xy), 0)");
}
}
imgexpr = remap_swizzle(get<SPIRType>(result_type), 4, imgexpr);
pure = true;
}
else
{
// imageLoad only accepts int coords, not uint.
auto coord_expr = to_expression(ops[3]);
auto target_coord_type = expression_type(ops[3]);
target_coord_type.basetype = SPIRType::Int;
coord_expr = bitcast_expression(target_coord_type, expression_type(ops[3]).basetype, coord_expr);
// Plain image load/store.
if (type.image.ms)
{
uint32_t operands = ops[4];
if (operands != ImageOperandsSampleMask || length != 6)
SPIRV_CROSS_THROW("Multisampled image used in OpImageRead, but unexpected operand mask was used.");
uint32_t samples = ops[5];
imgexpr =
join("imageLoad(", to_expression(ops[2]), ", ", coord_expr, ", ", to_expression(samples), ")");
}
else
imgexpr = join("imageLoad(", to_expression(ops[2]), ", ", coord_expr, ")");
imgexpr = remap_swizzle(get<SPIRType>(result_type), 4, imgexpr);
pure = false;
}
if (var && var->forwardable)
{
bool forward = forced_temporaries.find(id) == end(forced_temporaries);
auto &e = emit_op(result_type, id, imgexpr, forward);
// We only need to track dependencies if we're reading from image load/store.
if (!pure)
{
e.loaded_from = var->self;
if (forward)
var->dependees.push_back(id);
}
}
else
emit_op(result_type, id, imgexpr, false);
inherit_expression_dependencies(id, ops[2]);
if (type.image.ms)
inherit_expression_dependencies(id, ops[5]);
break;
}
case OpImageTexelPointer:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
auto &e = set<SPIRExpression>(id, join(to_expression(ops[2]), ", ", to_expression(ops[3])), result_type, true);
// When using the pointer, we need to know which variable it is actually loaded from.
auto *var = maybe_get_backing_variable(ops[2]);
e.loaded_from = var ? var->self : 0;
break;
}
case OpImageWrite:
{
// We added Nonwritable speculatively to the OpImage variable due to glslangValidator
// not adding the proper qualifiers.
// If it turns out we need to write to the image after all, remove the qualifier and recompile.
auto *var = maybe_get_backing_variable(ops[0]);
if (var)
{
auto &flags = ir.meta[var->self].decoration.decoration_flags;
if (flags.get(DecorationNonWritable))
{
flags.clear(DecorationNonWritable);
force_recompile();
}
}
auto &type = expression_type(ops[0]);
auto &value_type = expression_type(ops[2]);
auto store_type = value_type;
store_type.vecsize = 4;
// imageStore only accepts int coords, not uint.
auto coord_expr = to_expression(ops[1]);
auto target_coord_type = expression_type(ops[1]);
target_coord_type.basetype = SPIRType::Int;
coord_expr = bitcast_expression(target_coord_type, expression_type(ops[1]).basetype, coord_expr);
if (type.image.ms)
{
uint32_t operands = ops[3];
if (operands != ImageOperandsSampleMask || length != 5)
SPIRV_CROSS_THROW("Multisampled image used in OpImageWrite, but unexpected operand mask was used.");
uint32_t samples = ops[4];
statement("imageStore(", to_expression(ops[0]), ", ", coord_expr, ", ", to_expression(samples), ", ",
remap_swizzle(store_type, value_type.vecsize, to_expression(ops[2])), ");");
}
else
statement("imageStore(", to_expression(ops[0]), ", ", coord_expr, ", ",
remap_swizzle(store_type, value_type.vecsize, to_expression(ops[2])), ");");
if (var && variable_storage_is_aliased(*var))
flush_all_aliased_variables();
break;
}
case OpImageQuerySize:
{
auto &type = expression_type(ops[2]);
uint32_t result_type = ops[0];
uint32_t id = ops[1];
if (type.basetype == SPIRType::Image)
{
string expr;
if (type.image.sampled == 2)
{
// The size of an image is always constant.
expr = join("imageSize(", to_expression(ops[2]), ")");
}
else
{
// This path is hit for samplerBuffers and multisampled images which do not have LOD.
expr = join("textureSize(", convert_separate_image_to_expression(ops[2]), ")");
}
auto &restype = get<SPIRType>(ops[0]);
expr = bitcast_expression(restype, SPIRType::Int, expr);
emit_op(result_type, id, expr, true);
}
else
SPIRV_CROSS_THROW("Invalid type for OpImageQuerySize.");
break;
}
// Compute
case OpControlBarrier:
case OpMemoryBarrier:
{
uint32_t execution_scope = 0;
uint32_t memory;
uint32_t semantics;
if (opcode == OpMemoryBarrier)
{
memory = get<SPIRConstant>(ops[0]).scalar();
semantics = get<SPIRConstant>(ops[1]).scalar();
}
else
{
execution_scope = get<SPIRConstant>(ops[0]).scalar();
memory = get<SPIRConstant>(ops[1]).scalar();
semantics = get<SPIRConstant>(ops[2]).scalar();
}
if (execution_scope == ScopeSubgroup || memory == ScopeSubgroup)
{
if (!options.vulkan_semantics)
SPIRV_CROSS_THROW("Can only use subgroup operations in Vulkan semantics.");
require_extension_internal("GL_KHR_shader_subgroup_basic");
}
if (execution_scope != ScopeSubgroup && get_entry_point().model == ExecutionModelTessellationControl)
{
// Control shaders only have barriers, and it implies memory barriers.
if (opcode == OpControlBarrier)
statement("barrier();");
break;
}
// We only care about these flags, acquire/release and friends are not relevant to GLSL.
semantics = mask_relevant_memory_semantics(semantics);
if (opcode == OpMemoryBarrier)
{
// If we are a memory barrier, and the next instruction is a control barrier, check if that memory barrier
// does what we need, so we avoid redundant barriers.
const Instruction *next = get_next_instruction_in_block(instruction);
if (next && next->op == OpControlBarrier)
{
auto *next_ops = stream(*next);
uint32_t next_memory = get<SPIRConstant>(next_ops[1]).scalar();
uint32_t next_semantics = get<SPIRConstant>(next_ops[2]).scalar();
next_semantics = mask_relevant_memory_semantics(next_semantics);
bool memory_scope_covered = false;
if (next_memory == memory)
memory_scope_covered = true;
else if (next_semantics == MemorySemanticsWorkgroupMemoryMask)
{
// If we only care about workgroup memory, either Device or Workgroup scope is fine,
// scope does not have to match.
if ((next_memory == ScopeDevice || next_memory == ScopeWorkgroup) &&
(memory == ScopeDevice || memory == ScopeWorkgroup))
{
memory_scope_covered = true;
}
}
else if (memory == ScopeWorkgroup && next_memory == ScopeDevice)
{
// The control barrier has device scope, but the memory barrier just has workgroup scope.
memory_scope_covered = true;
}
// If we have the same memory scope, and all memory types are covered, we're good.
if (memory_scope_covered && (semantics & next_semantics) == semantics)
break;
}
}
// We are synchronizing some memory or syncing execution,
// so we cannot forward any loads beyond the memory barrier.
if (semantics || opcode == OpControlBarrier)
{
assert(current_emitting_block);
flush_control_dependent_expressions(current_emitting_block->self);
flush_all_active_variables();
}
if (memory == ScopeWorkgroup) // Only need to consider memory within a group
{
if (semantics == MemorySemanticsWorkgroupMemoryMask)
statement("memoryBarrierShared();");
else if (semantics != 0)
statement("groupMemoryBarrier();");
}
else if (memory == ScopeSubgroup)
{
const uint32_t all_barriers =
MemorySemanticsWorkgroupMemoryMask | MemorySemanticsUniformMemoryMask | MemorySemanticsImageMemoryMask;
if (semantics & (MemorySemanticsCrossWorkgroupMemoryMask | MemorySemanticsSubgroupMemoryMask))
{
// These are not relevant for GLSL, but assume it means memoryBarrier().
// memoryBarrier() does everything, so no need to test anything else.
statement("subgroupMemoryBarrier();");
}
else if ((semantics & all_barriers) == all_barriers)
{
// Short-hand instead of emitting 3 barriers.
statement("subgroupMemoryBarrier();");
}
else
{
// Pick out individual barriers.
if (semantics & MemorySemanticsWorkgroupMemoryMask)
statement("subgroupMemoryBarrierShared();");
if (semantics & MemorySemanticsUniformMemoryMask)
statement("subgroupMemoryBarrierBuffer();");
if (semantics & MemorySemanticsImageMemoryMask)
statement("subgroupMemoryBarrierImage();");
}
}
else
{
const uint32_t all_barriers = MemorySemanticsWorkgroupMemoryMask | MemorySemanticsUniformMemoryMask |
MemorySemanticsImageMemoryMask | MemorySemanticsAtomicCounterMemoryMask;
if (semantics & (MemorySemanticsCrossWorkgroupMemoryMask | MemorySemanticsSubgroupMemoryMask))
{
// These are not relevant for GLSL, but assume it means memoryBarrier().
// memoryBarrier() does everything, so no need to test anything else.
statement("memoryBarrier();");
}
else if ((semantics & all_barriers) == all_barriers)
{
// Short-hand instead of emitting 4 barriers.
statement("memoryBarrier();");
}
else
{
// Pick out individual barriers.
if (semantics & MemorySemanticsWorkgroupMemoryMask)
statement("memoryBarrierShared();");
if (semantics & MemorySemanticsUniformMemoryMask)
statement("memoryBarrierBuffer();");
if (semantics & MemorySemanticsImageMemoryMask)
statement("memoryBarrierImage();");
if (semantics & MemorySemanticsAtomicCounterMemoryMask)
statement("memoryBarrierAtomicCounter();");
}
}
if (opcode == OpControlBarrier)
{
if (execution_scope == ScopeSubgroup)
statement("subgroupBarrier();");
else
statement("barrier();");
}
break;
}
case OpExtInst:
{
uint32_t extension_set = ops[2];
if (get<SPIRExtension>(extension_set).ext == SPIRExtension::GLSL)
{
emit_glsl_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
}
else if (get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_AMD_shader_ballot)
{
emit_spv_amd_shader_ballot_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
}
else if (get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_AMD_shader_explicit_vertex_parameter)
{
emit_spv_amd_shader_explicit_vertex_parameter_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
}
else if (get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_AMD_shader_trinary_minmax)
{
emit_spv_amd_shader_trinary_minmax_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
}
else if (get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_AMD_gcn_shader)
{
emit_spv_amd_gcn_shader_op(ops[0], ops[1], ops[3], &ops[4], length - 4);
}
else if (get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_debug_info)
{
break; // Ignore SPIR-V debug information extended instructions.
}
else
{
statement("// unimplemented ext op ", instruction.op);
break;
}
break;
}
// Legacy sub-group stuff ...
case OpSubgroupBallotKHR:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
string expr;
expr = join("uvec4(unpackUint2x32(ballotARB(" + to_expression(ops[2]) + ")), 0u, 0u)");
emit_op(result_type, id, expr, should_forward(ops[2]));
require_extension_internal("GL_ARB_shader_ballot");
inherit_expression_dependencies(id, ops[2]);
register_control_dependent_expression(ops[1]);
break;
}
case OpSubgroupFirstInvocationKHR:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[2], "readFirstInvocationARB");
require_extension_internal("GL_ARB_shader_ballot");
register_control_dependent_expression(ops[1]);
break;
}
case OpSubgroupReadInvocationKHR:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_binary_func_op(result_type, id, ops[2], ops[3], "readInvocationARB");
require_extension_internal("GL_ARB_shader_ballot");
register_control_dependent_expression(ops[1]);
break;
}
case OpSubgroupAllKHR:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[2], "allInvocationsARB");
require_extension_internal("GL_ARB_shader_group_vote");
register_control_dependent_expression(ops[1]);
break;
}
case OpSubgroupAnyKHR:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[2], "anyInvocationARB");
require_extension_internal("GL_ARB_shader_group_vote");
register_control_dependent_expression(ops[1]);
break;
}
case OpSubgroupAllEqualKHR:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[2], "allInvocationsEqualARB");
require_extension_internal("GL_ARB_shader_group_vote");
register_control_dependent_expression(ops[1]);
break;
}
case OpGroupIAddNonUniformAMD:
case OpGroupFAddNonUniformAMD:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[4], "addInvocationsNonUniformAMD");
require_extension_internal("GL_AMD_shader_ballot");
register_control_dependent_expression(ops[1]);
break;
}
case OpGroupFMinNonUniformAMD:
case OpGroupUMinNonUniformAMD:
case OpGroupSMinNonUniformAMD:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[4], "minInvocationsNonUniformAMD");
require_extension_internal("GL_AMD_shader_ballot");
register_control_dependent_expression(ops[1]);
break;
}
case OpGroupFMaxNonUniformAMD:
case OpGroupUMaxNonUniformAMD:
case OpGroupSMaxNonUniformAMD:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
emit_unary_func_op(result_type, id, ops[4], "maxInvocationsNonUniformAMD");
require_extension_internal("GL_AMD_shader_ballot");
register_control_dependent_expression(ops[1]);
break;
}
case OpFragmentMaskFetchAMD:
{
auto &type = expression_type(ops[2]);
uint32_t result_type = ops[0];
uint32_t id = ops[1];
if (type.image.dim == spv::DimSubpassData)
{
emit_unary_func_op(result_type, id, ops[2], "fragmentMaskFetchAMD");
}
else
{
emit_binary_func_op(result_type, id, ops[2], ops[3], "fragmentMaskFetchAMD");
}
require_extension_internal("GL_AMD_shader_fragment_mask");
break;
}
case OpFragmentFetchAMD:
{
auto &type = expression_type(ops[2]);
uint32_t result_type = ops[0];
uint32_t id = ops[1];
if (type.image.dim == spv::DimSubpassData)
{
emit_binary_func_op(result_type, id, ops[2], ops[4], "fragmentFetchAMD");
}
else
{
emit_trinary_func_op(result_type, id, ops[2], ops[3], ops[4], "fragmentFetchAMD");
}
require_extension_internal("GL_AMD_shader_fragment_mask");
break;
}
// Vulkan 1.1 sub-group stuff ...
case OpGroupNonUniformElect:
case OpGroupNonUniformBroadcast:
case OpGroupNonUniformBroadcastFirst:
case OpGroupNonUniformBallot:
case OpGroupNonUniformInverseBallot:
case OpGroupNonUniformBallotBitExtract:
case OpGroupNonUniformBallotBitCount:
case OpGroupNonUniformBallotFindLSB:
case OpGroupNonUniformBallotFindMSB:
case OpGroupNonUniformShuffle:
case OpGroupNonUniformShuffleXor:
case OpGroupNonUniformShuffleUp:
case OpGroupNonUniformShuffleDown:
case OpGroupNonUniformAll:
case OpGroupNonUniformAny:
case OpGroupNonUniformAllEqual:
case OpGroupNonUniformFAdd:
case OpGroupNonUniformIAdd:
case OpGroupNonUniformFMul:
case OpGroupNonUniformIMul:
case OpGroupNonUniformFMin:
case OpGroupNonUniformFMax:
case OpGroupNonUniformSMin:
case OpGroupNonUniformSMax:
case OpGroupNonUniformUMin:
case OpGroupNonUniformUMax:
case OpGroupNonUniformBitwiseAnd:
case OpGroupNonUniformBitwiseOr:
case OpGroupNonUniformBitwiseXor:
case OpGroupNonUniformQuadSwap:
case OpGroupNonUniformQuadBroadcast:
emit_subgroup_op(instruction);
break;
case OpFUnordEqual:
GLSL_BFOP(unsupported_FUnordEqual);
break;
case OpFUnordNotEqual:
GLSL_BFOP(unsupported_FUnordNotEqual);
break;
case OpFUnordLessThan:
GLSL_BFOP(unsupported_FUnordLessThan);
break;
case OpFUnordGreaterThan:
GLSL_BFOP(unsupported_FUnordGreaterThan);
break;
case OpFUnordLessThanEqual:
GLSL_BFOP(unsupported_FUnordLessThanEqual);
break;
case OpFUnordGreaterThanEqual:
GLSL_BFOP(unsupported_FUnordGreaterThanEqual);
break;
case OpReportIntersectionNV:
statement("reportIntersectionNV(", to_expression(ops[0]), ", ", to_expression(ops[1]), ");");
break;
case OpIgnoreIntersectionNV:
statement("ignoreIntersectionNV();");
break;
case OpTerminateRayNV:
statement("terminateRayNV();");
break;
case OpTraceNV:
statement("traceNV(", to_expression(ops[0]), ", ", to_expression(ops[1]), ", ", to_expression(ops[2]), ", ",
to_expression(ops[3]), ", ", to_expression(ops[4]), ", ", to_expression(ops[5]), ", ",
to_expression(ops[6]), ", ", to_expression(ops[7]), ", ", to_expression(ops[8]), ", ",
to_expression(ops[9]), ", ", to_expression(ops[10]), ");");
break;
case OpExecuteCallableNV:
statement("executeCallableNV(", to_expression(ops[0]), ", ", to_expression(ops[1]), ");");
break;
case OpConvertUToPtr:
{
auto &type = get<SPIRType>(ops[0]);
if (type.storage != StorageClassPhysicalStorageBufferEXT)
SPIRV_CROSS_THROW("Only StorageClassPhysicalStorageBufferEXT is supported by OpConvertUToPtr.");
auto op = type_to_glsl(type);
emit_unary_func_op(ops[0], ops[1], ops[2], op.c_str());
break;
}
case OpConvertPtrToU:
{
auto &type = get<SPIRType>(ops[0]);
auto &ptr_type = expression_type(ops[2]);
if (ptr_type.storage != StorageClassPhysicalStorageBufferEXT)
SPIRV_CROSS_THROW("Only StorageClassPhysicalStorageBufferEXT is supported by OpConvertPtrToU.");
auto op = type_to_glsl(type);
emit_unary_func_op(ops[0], ops[1], ops[2], op.c_str());
break;
}
case OpUndef:
// Undefined value has been declared.
break;
case OpLine:
{
emit_line_directive(ops[0], ops[1]);
break;
}
case OpNoLine:
break;
default:
statement("// unimplemented op ", instruction.op);
break;
}
}
// Appends function arguments, mapped from global variables, beyond the specified arg index.
// This is used when a function call uses fewer arguments than the function defines.
// This situation may occur if the function signature has been dynamically modified to
// extract global variables referenced from within the function, and convert them to
// function arguments. This is necessary for shader languages that do not support global
// access to shader input content from within a function (eg. Metal). Each additional
// function args uses the name of the global variable. Function nesting will modify the
// functions and function calls all the way up the nesting chain.
void CompilerGLSL::append_global_func_args(const SPIRFunction &func, uint32_t index, SmallVector<string> &arglist)
{
auto &args = func.arguments;
uint32_t arg_cnt = uint32_t(args.size());
for (uint32_t arg_idx = index; arg_idx < arg_cnt; arg_idx++)
{
auto &arg = args[arg_idx];
assert(arg.alias_global_variable);
// If the underlying variable needs to be declared
// (ie. a local variable with deferred declaration), do so now.
uint32_t var_id = get<SPIRVariable>(arg.id).basevariable;
if (var_id)
flush_variable_declaration(var_id);
arglist.push_back(to_func_call_arg(arg.id));
}
}
string CompilerGLSL::to_member_name(const SPIRType &type, uint32_t index)
{
auto &memb = ir.meta[type.self].members;
if (index < memb.size() && !memb[index].alias.empty())
return memb[index].alias;
else
return join("_m", index);
}
string CompilerGLSL::to_member_reference(uint32_t, const SPIRType &type, uint32_t index, bool)
{
return join(".", to_member_name(type, index));
}
void CompilerGLSL::add_member_name(SPIRType &type, uint32_t index)
{
auto &memb = ir.meta[type.self].members;
if (index < memb.size() && !memb[index].alias.empty())
{
auto &name = memb[index].alias;
if (name.empty())
return;
// Reserved for temporaries.
if (name[0] == '_' && name.size() >= 2 && isdigit(name[1]))
{
name.clear();
return;
}
update_name_cache(type.member_name_cache, name);
}
}
// Checks whether the ID is a row_major matrix that requires conversion before use
bool CompilerGLSL::is_non_native_row_major_matrix(uint32_t id)
{
// Natively supported row-major matrices do not need to be converted.
// Legacy targets do not support row major.
if (backend.native_row_major_matrix && !is_legacy())
return false;
// Non-matrix or column-major matrix types do not need to be converted.
if (!has_decoration(id, DecorationRowMajor))
return false;
// Only square row-major matrices can be converted at this time.
// Converting non-square matrices will require defining custom GLSL function that
// swaps matrix elements while retaining the original dimensional form of the matrix.
const auto type = expression_type(id);
if (type.columns != type.vecsize)
SPIRV_CROSS_THROW("Row-major matrices must be square on this platform.");
return true;
}
// Checks whether the member is a row_major matrix that requires conversion before use
bool CompilerGLSL::member_is_non_native_row_major_matrix(const SPIRType &type, uint32_t index)
{
// Natively supported row-major matrices do not need to be converted.
if (backend.native_row_major_matrix && !is_legacy())
return false;
// Non-matrix or column-major matrix types do not need to be converted.
if (!has_member_decoration(type.self, index, DecorationRowMajor))
return false;
// Only square row-major matrices can be converted at this time.
// Converting non-square matrices will require defining custom GLSL function that
// swaps matrix elements while retaining the original dimensional form of the matrix.
const auto mbr_type = get<SPIRType>(type.member_types[index]);
if (mbr_type.columns != mbr_type.vecsize)
SPIRV_CROSS_THROW("Row-major matrices must be square on this platform.");
return true;
}
// Checks whether the member is in packed data type, that might need to be unpacked.
// GLSL does not define packed data types, but certain subclasses do.
bool CompilerGLSL::member_is_packed_type(const SPIRType &type, uint32_t index) const
{
return has_extended_member_decoration(type.self, index, SPIRVCrossDecorationPacked);
}
// Wraps the expression string in a function call that converts the
// row_major matrix result of the expression to a column_major matrix.
// Base implementation uses the standard library transpose() function.
// Subclasses may override to use a different function.
string CompilerGLSL::convert_row_major_matrix(string exp_str, const SPIRType & /*exp_type*/, bool /*is_packed*/)
{
strip_enclosed_expression(exp_str);
return join("transpose(", exp_str, ")");
}
string CompilerGLSL::variable_decl(const SPIRType &type, const string &name, uint32_t id)
{
string type_name = type_to_glsl(type, id);
remap_variable_type_name(type, name, type_name);
return join(type_name, " ", name, type_to_array_glsl(type));
}
// Emit a structure member. Subclasses may override to modify output,
// or to dynamically add a padding member if needed.
void CompilerGLSL::emit_struct_member(const SPIRType &type, uint32_t member_type_id, uint32_t index,
const string &qualifier, uint32_t)
{
auto &membertype = get<SPIRType>(member_type_id);
Bitset memberflags;
auto &memb = ir.meta[type.self].members;
if (index < memb.size())
memberflags = memb[index].decoration_flags;
string qualifiers;
bool is_block = ir.meta[type.self].decoration.decoration_flags.get(DecorationBlock) ||
ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock);
if (is_block)
qualifiers = to_interpolation_qualifiers(memberflags);
statement(layout_for_member(type, index), qualifiers, qualifier, flags_to_qualifiers_glsl(membertype, memberflags),
variable_decl(membertype, to_member_name(type, index)), ";");
}
const char *CompilerGLSL::flags_to_qualifiers_glsl(const SPIRType &type, const Bitset &flags)
{
// GL_EXT_buffer_reference variables can be marked as restrict.
if (flags.get(DecorationRestrictPointerEXT))
return "restrict ";
// Structs do not have precision qualifiers, neither do doubles (desktop only anyways, so no mediump/highp).
if (type.basetype != SPIRType::Float && type.basetype != SPIRType::Int && type.basetype != SPIRType::UInt &&
type.basetype != SPIRType::Image && type.basetype != SPIRType::SampledImage &&
type.basetype != SPIRType::Sampler)
return "";
if (options.es)
{
auto &execution = get_entry_point();
if (flags.get(DecorationRelaxedPrecision))
{
bool implied_fmediump = type.basetype == SPIRType::Float &&
options.fragment.default_float_precision == Options::Mediump &&
execution.model == ExecutionModelFragment;
bool implied_imediump = (type.basetype == SPIRType::Int || type.basetype == SPIRType::UInt) &&
options.fragment.default_int_precision == Options::Mediump &&
execution.model == ExecutionModelFragment;
return implied_fmediump || implied_imediump ? "" : "mediump ";
}
else
{
bool implied_fhighp =
type.basetype == SPIRType::Float && ((options.fragment.default_float_precision == Options::Highp &&
execution.model == ExecutionModelFragment) ||
(execution.model != ExecutionModelFragment));
bool implied_ihighp = (type.basetype == SPIRType::Int || type.basetype == SPIRType::UInt) &&
((options.fragment.default_int_precision == Options::Highp &&
execution.model == ExecutionModelFragment) ||
(execution.model != ExecutionModelFragment));
return implied_fhighp || implied_ihighp ? "" : "highp ";
}
}
else if (backend.allow_precision_qualifiers)
{
// Vulkan GLSL supports precision qualifiers, even in desktop profiles, which is convenient.
// The default is highp however, so only emit mediump in the rare case that a shader has these.
if (flags.get(DecorationRelaxedPrecision))
return "mediump ";
else
return "";
}
else
return "";
}
const char *CompilerGLSL::to_precision_qualifiers_glsl(uint32_t id)
{
auto &type = expression_type(id);
bool use_precision_qualifiers = backend.allow_precision_qualifiers || options.es;
if (use_precision_qualifiers && (type.basetype == SPIRType::Image || type.basetype == SPIRType::SampledImage))
{
// Force mediump for the sampler type. We cannot declare 16-bit or smaller image types.
auto &result_type = get<SPIRType>(type.image.type);
if (result_type.width < 32)
return "mediump ";
}
return flags_to_qualifiers_glsl(type, ir.meta[id].decoration.decoration_flags);
}
string CompilerGLSL::to_qualifiers_glsl(uint32_t id)
{
auto &flags = ir.meta[id].decoration.decoration_flags;
string res;
auto *var = maybe_get<SPIRVariable>(id);
if (var && var->storage == StorageClassWorkgroup && !backend.shared_is_implied)
res += "shared ";
res += to_interpolation_qualifiers(flags);
if (var)
res += to_storage_qualifiers_glsl(*var);
auto &type = expression_type(id);
if (type.image.dim != DimSubpassData && type.image.sampled == 2)
{
if (flags.get(DecorationCoherent))
res += "coherent ";
if (flags.get(DecorationRestrict))
res += "restrict ";
if (flags.get(DecorationNonWritable))
res += "readonly ";
if (flags.get(DecorationNonReadable))
res += "writeonly ";
}
res += to_precision_qualifiers_glsl(id);
return res;
}
string CompilerGLSL::argument_decl(const SPIRFunction::Parameter &arg)
{
// glslangValidator seems to make all arguments pointer no matter what which is rather bizarre ...
auto &type = expression_type(arg.id);
const char *direction = "";
if (type.pointer)
{
if (arg.write_count && arg.read_count)
direction = "inout ";
else if (arg.write_count)
direction = "out ";
}
return join(direction, to_qualifiers_glsl(arg.id), variable_decl(type, to_name(arg.id), arg.id));
}
string CompilerGLSL::to_initializer_expression(const SPIRVariable &var)
{
return to_expression(var.initializer);
}
string CompilerGLSL::variable_decl(const SPIRVariable &variable)
{
// Ignore the pointer type since GLSL doesn't have pointers.
auto &type = get_variable_data_type(variable);
if (type.pointer_depth > 1)
SPIRV_CROSS_THROW("Cannot declare pointer-to-pointer types.");
auto res = join(to_qualifiers_glsl(variable.self), variable_decl(type, to_name(variable.self), variable.self));
if (variable.loop_variable && variable.static_expression)
{
uint32_t expr = variable.static_expression;
if (ir.ids[expr].get_type() != TypeUndef)
res += join(" = ", to_expression(variable.static_expression));
}
else if (variable.initializer)
{
uint32_t expr = variable.initializer;
if (ir.ids[expr].get_type() != TypeUndef)
res += join(" = ", to_initializer_expression(variable));
}
return res;
}
const char *CompilerGLSL::to_pls_qualifiers_glsl(const SPIRVariable &variable)
{
auto &flags = ir.meta[variable.self].decoration.decoration_flags;
if (flags.get(DecorationRelaxedPrecision))
return "mediump ";
else
return "highp ";
}
string CompilerGLSL::pls_decl(const PlsRemap &var)
{
auto &variable = get<SPIRVariable>(var.id);
SPIRType type;
type.vecsize = pls_format_to_components(var.format);
type.basetype = pls_format_to_basetype(var.format);
return join(to_pls_layout(var.format), to_pls_qualifiers_glsl(variable), type_to_glsl(type), " ",
to_name(variable.self));
}
uint32_t CompilerGLSL::to_array_size_literal(const SPIRType &type) const
{
return to_array_size_literal(type, uint32_t(type.array.size() - 1));
}
uint32_t CompilerGLSL::to_array_size_literal(const SPIRType &type, uint32_t index) const
{
assert(type.array.size() == type.array_size_literal.size());
if (type.array_size_literal[index])
{
return type.array[index];
}
else
{
// Use the default spec constant value.
// This is the best we can do.
uint32_t array_size_id = type.array[index];
// Explicitly check for this case. The error message you would get (bad cast) makes no sense otherwise.
if (ir.ids[array_size_id].get_type() == TypeConstantOp)
SPIRV_CROSS_THROW("An array size was found to be an OpSpecConstantOp. This is not supported since "
"SPIRV-Cross cannot deduce the actual size here.");
uint32_t array_size = get<SPIRConstant>(array_size_id).scalar();
return array_size;
}
}
string CompilerGLSL::to_array_size(const SPIRType &type, uint32_t index)
{
assert(type.array.size() == type.array_size_literal.size());
// Tessellation control and evaluation shaders must have either gl_MaxPatchVertices or unsized arrays for input arrays.
// Opt for unsized as it's the more "correct" variant to use.
if (type.storage == StorageClassInput && (get_entry_point().model == ExecutionModelTessellationControl ||
get_entry_point().model == ExecutionModelTessellationEvaluation))
return "";
auto &size = type.array[index];
if (!type.array_size_literal[index])
return to_expression(size);
else if (size)
return convert_to_string(size);
else if (!backend.unsized_array_supported)
{
// For runtime-sized arrays, we can work around
// lack of standard support for this by simply having
// a single element array.
//
// Runtime length arrays must always be the last element
// in an interface block.
return "1";
}
else
return "";
}
string CompilerGLSL::type_to_array_glsl(const SPIRType &type)
{
if (type.pointer && type.storage == StorageClassPhysicalStorageBufferEXT && type.basetype != SPIRType::Struct)
{
// We are using a wrapped pointer type, and we should not emit any array declarations here.
return "";
}
if (type.array.empty())
return "";
if (options.flatten_multidimensional_arrays)
{
string res;
res += "[";
for (auto i = uint32_t(type.array.size()); i; i--)
{
res += enclose_expression(to_array_size(type, i - 1));
if (i > 1)
res += " * ";
}
res += "]";
return res;
}
else
{
if (type.array.size() > 1)
{
if (!options.es && options.version < 430)
require_extension_internal("GL_ARB_arrays_of_arrays");
else if (options.es && options.version < 310)
SPIRV_CROSS_THROW("Arrays of arrays not supported before ESSL version 310. "
"Try using --flatten-multidimensional-arrays or set "
"options.flatten_multidimensional_arrays to true.");
}
string res;
for (auto i = uint32_t(type.array.size()); i; i--)
{
res += "[";
res += to_array_size(type, i - 1);
res += "]";
}
return res;
}
}
string CompilerGLSL::image_type_glsl(const SPIRType &type, uint32_t id)
{
auto &imagetype = get<SPIRType>(type.image.type);
string res;
switch (imagetype.basetype)
{
case SPIRType::Int:
case SPIRType::Short:
case SPIRType::SByte:
res = "i";
break;
case SPIRType::UInt:
case SPIRType::UShort:
case SPIRType::UByte:
res = "u";
break;
default:
break;
}
// For half image types, we will force mediump for the sampler, and cast to f16 after any sampling operation.
// We cannot express a true half texture type in GLSL. Neither for short integer formats for that matter.
if (type.basetype == SPIRType::Image && type.image.dim == DimSubpassData && options.vulkan_semantics)
return res + "subpassInput" + (type.image.ms ? "MS" : "");
// If we're emulating subpassInput with samplers, force sampler2D
// so we don't have to specify format.
if (type.basetype == SPIRType::Image && type.image.dim != DimSubpassData)
{
// Sampler buffers are always declared as samplerBuffer even though they might be separate images in the SPIR-V.
if (type.image.dim == DimBuffer && type.image.sampled == 1)
res += "sampler";
else
res += type.image.sampled == 2 ? "image" : "texture";
}
else
res += "sampler";
switch (type.image.dim)
{
case Dim1D:
res += "1D";
break;
case Dim2D:
res += "2D";
break;
case Dim3D:
res += "3D";
break;
case DimCube:
res += "Cube";
break;
case DimRect:
if (options.es)
SPIRV_CROSS_THROW("Rectangle textures are not supported on OpenGL ES.");
if (is_legacy_desktop())
require_extension_internal("GL_ARB_texture_rectangle");
res += "2DRect";
break;
case DimBuffer:
if (options.es && options.version < 320)
require_extension_internal("GL_OES_texture_buffer");
else if (!options.es && options.version < 300)
require_extension_internal("GL_EXT_texture_buffer_object");
res += "Buffer";
break;
case DimSubpassData:
res += "2D";
break;
default:
SPIRV_CROSS_THROW("Only 1D, 2D, 2DRect, 3D, Buffer, InputTarget and Cube textures supported.");
}
if (type.image.ms)
res += "MS";
if (type.image.arrayed)
{
if (is_legacy_desktop())
require_extension_internal("GL_EXT_texture_array");
res += "Array";
}
// "Shadow" state in GLSL only exists for samplers and combined image samplers.
if (((type.basetype == SPIRType::SampledImage) || (type.basetype == SPIRType::Sampler)) &&
image_is_comparison(type, id))
{
res += "Shadow";
}
return res;
}
string CompilerGLSL::type_to_glsl_constructor(const SPIRType &type)
{
if (type.array.size() > 1)
{
if (options.flatten_multidimensional_arrays)
SPIRV_CROSS_THROW("Cannot flatten constructors of multidimensional array constructors, e.g. float[][]().");
else if (!options.es && options.version < 430)
require_extension_internal("GL_ARB_arrays_of_arrays");
else if (options.es && options.version < 310)
SPIRV_CROSS_THROW("Arrays of arrays not supported before ESSL version 310.");
}
auto e = type_to_glsl(type);
for (uint32_t i = 0; i < type.array.size(); i++)
e += "[]";
return e;
}
// The optional id parameter indicates the object whose type we are trying
// to find the description for. It is optional. Most type descriptions do not
// depend on a specific object's use of that type.
string CompilerGLSL::type_to_glsl(const SPIRType &type, uint32_t id)
{
if (type.pointer && type.storage == StorageClassPhysicalStorageBufferEXT && type.basetype != SPIRType::Struct)
{
// Need to create a magic type name which compacts the entire type information.
string name = type_to_glsl(get_pointee_type(type));
for (size_t i = 0; i < type.array.size(); i++)
{
if (type.array_size_literal[i])
name += join(type.array[i], "_");
else
name += join("id", type.array[i], "_");
}
name += "Pointer";
return name;
}
switch (type.basetype)
{
case SPIRType::Struct:
// Need OpName lookup here to get a "sensible" name for a struct.
if (backend.explicit_struct_type)
return join("struct ", to_name(type.self));
else
return to_name(type.self);
case SPIRType::Image:
case SPIRType::SampledImage:
return image_type_glsl(type, id);
case SPIRType::Sampler:
// The depth field is set by calling code based on the variable ID of the sampler, effectively reintroducing
// this distinction into the type system.
return comparison_ids.count(id) ? "samplerShadow" : "sampler";
case SPIRType::AccelerationStructureNV:
return "accelerationStructureNV";
case SPIRType::Void:
return "void";
default:
break;
}
if (type.basetype == SPIRType::UInt && is_legacy())
SPIRV_CROSS_THROW("Unsigned integers are not supported on legacy targets.");
if (type.vecsize == 1 && type.columns == 1) // Scalar builtin
{
switch (type.basetype)
{
case SPIRType::Boolean:
return "bool";
case SPIRType::SByte:
return backend.basic_int8_type;
case SPIRType::UByte:
return backend.basic_uint8_type;
case SPIRType::Short:
return backend.basic_int16_type;
case SPIRType::UShort:
return backend.basic_uint16_type;
case SPIRType::Int:
return backend.basic_int_type;
case SPIRType::UInt:
return backend.basic_uint_type;
case SPIRType::AtomicCounter:
return "atomic_uint";
case SPIRType::Half:
return "float16_t";
case SPIRType::Float:
return "float";
case SPIRType::Double:
return "double";
case SPIRType::Int64:
return "int64_t";
case SPIRType::UInt64:
return "uint64_t";
default:
return "???";
}
}
else if (type.vecsize > 1 && type.columns == 1) // Vector builtin
{
switch (type.basetype)
{
case SPIRType::Boolean:
return join("bvec", type.vecsize);
case SPIRType::SByte:
return join("i8vec", type.vecsize);
case SPIRType::UByte:
return join("u8vec", type.vecsize);
case SPIRType::Short:
return join("i16vec", type.vecsize);
case SPIRType::UShort:
return join("u16vec", type.vecsize);
case SPIRType::Int:
return join("ivec", type.vecsize);
case SPIRType::UInt:
return join("uvec", type.vecsize);
case SPIRType::Half:
return join("f16vec", type.vecsize);
case SPIRType::Float:
return join("vec", type.vecsize);
case SPIRType::Double:
return join("dvec", type.vecsize);
case SPIRType::Int64:
return join("i64vec", type.vecsize);
case SPIRType::UInt64:
return join("u64vec", type.vecsize);
default:
return "???";
}
}
else if (type.vecsize == type.columns) // Simple Matrix builtin
{
switch (type.basetype)
{
case SPIRType::Boolean:
return join("bmat", type.vecsize);
case SPIRType::Int:
return join("imat", type.vecsize);
case SPIRType::UInt:
return join("umat", type.vecsize);
case SPIRType::Half:
return join("f16mat", type.vecsize);
case SPIRType::Float:
return join("mat", type.vecsize);
case SPIRType::Double:
return join("dmat", type.vecsize);
// Matrix types not supported for int64/uint64.
default:
return "???";
}
}
else
{
switch (type.basetype)
{
case SPIRType::Boolean:
return join("bmat", type.columns, "x", type.vecsize);
case SPIRType::Int:
return join("imat", type.columns, "x", type.vecsize);
case SPIRType::UInt:
return join("umat", type.columns, "x", type.vecsize);
case SPIRType::Half:
return join("f16mat", type.columns, "x", type.vecsize);
case SPIRType::Float:
return join("mat", type.columns, "x", type.vecsize);
case SPIRType::Double:
return join("dmat", type.columns, "x", type.vecsize);
// Matrix types not supported for int64/uint64.
default:
return "???";
}
}
}
void CompilerGLSL::add_variable(unordered_set<string> &variables_primary,
const unordered_set<string> &variables_secondary, string &name)
{
if (name.empty())
return;
// Reserved for temporaries.
if (name[0] == '_' && name.size() >= 2 && isdigit(name[1]))
{
name.clear();
return;
}
// Avoid double underscores.
name = sanitize_underscores(name);
update_name_cache(variables_primary, variables_secondary, name);
}
void CompilerGLSL::add_local_variable_name(uint32_t id)
{
add_variable(local_variable_names, block_names, ir.meta[id].decoration.alias);
}
void CompilerGLSL::add_resource_name(uint32_t id)
{
add_variable(resource_names, block_names, ir.meta[id].decoration.alias);
}
void CompilerGLSL::add_header_line(const std::string &line)
{
header_lines.push_back(line);
}
bool CompilerGLSL::has_extension(const std::string &ext) const
{
auto itr = find(begin(forced_extensions), end(forced_extensions), ext);
return itr != end(forced_extensions);
}
void CompilerGLSL::require_extension(const std::string &ext)
{
if (!has_extension(ext))
forced_extensions.push_back(ext);
}
void CompilerGLSL::require_extension_internal(const string &ext)
{
if (backend.supports_extensions && !has_extension(ext))
{
forced_extensions.push_back(ext);
force_recompile();
}
}
void CompilerGLSL::flatten_buffer_block(uint32_t id)
{
auto &var = get<SPIRVariable>(id);
auto &type = get<SPIRType>(var.basetype);
auto name = to_name(type.self, false);
auto &flags = ir.meta[type.self].decoration.decoration_flags;
if (!type.array.empty())
SPIRV_CROSS_THROW(name + " is an array of UBOs.");
if (type.basetype != SPIRType::Struct)
SPIRV_CROSS_THROW(name + " is not a struct.");
if (!flags.get(DecorationBlock))
SPIRV_CROSS_THROW(name + " is not a block.");
if (type.member_types.empty())
SPIRV_CROSS_THROW(name + " is an empty struct.");
flattened_buffer_blocks.insert(id);
}
bool CompilerGLSL::check_atomic_image(uint32_t id)
{
auto &type = expression_type(id);
if (type.storage == StorageClassImage)
{
if (options.es && options.version < 320)
require_extension_internal("GL_OES_shader_image_atomic");
auto *var = maybe_get_backing_variable(id);
if (var)
{
auto &flags = ir.meta[var->self].decoration.decoration_flags;
if (flags.get(DecorationNonWritable) || flags.get(DecorationNonReadable))
{
flags.clear(DecorationNonWritable);
flags.clear(DecorationNonReadable);
force_recompile();
}
}
return true;
}
else
return false;
}
void CompilerGLSL::add_function_overload(const SPIRFunction &func)
{
Hasher hasher;
for (auto &arg : func.arguments)
{
// Parameters can vary with pointer type or not,
// but that will not change the signature in GLSL/HLSL,
// so strip the pointer type before hashing.
uint32_t type_id = get_pointee_type_id(arg.type);
auto &type = get<SPIRType>(type_id);
if (!combined_image_samplers.empty())
{
// If we have combined image samplers, we cannot really trust the image and sampler arguments
// we pass down to callees, because they may be shuffled around.
// Ignore these arguments, to make sure that functions need to differ in some other way
// to be considered different overloads.
if (type.basetype == SPIRType::SampledImage ||
(type.basetype == SPIRType::Image && type.image.sampled == 1) || type.basetype == SPIRType::Sampler)
{
continue;
}
}
hasher.u32(type_id);
}
uint64_t types_hash = hasher.get();
auto function_name = to_name(func.self);
auto itr = function_overloads.find(function_name);
if (itr != end(function_overloads))
{
// There exists a function with this name already.
auto &overloads = itr->second;
if (overloads.count(types_hash) != 0)
{
// Overload conflict, assign a new name.
add_resource_name(func.self);
function_overloads[to_name(func.self)].insert(types_hash);
}
else
{
// Can reuse the name.
overloads.insert(types_hash);
}
}
else
{
// First time we see this function name.
add_resource_name(func.self);
function_overloads[to_name(func.self)].insert(types_hash);
}
}
void CompilerGLSL::emit_function_prototype(SPIRFunction &func, const Bitset &return_flags)
{
if (func.self != ir.default_entry_point)
add_function_overload(func);
// Avoid shadow declarations.
local_variable_names = resource_names;
string decl;
auto &type = get<SPIRType>(func.return_type);
decl += flags_to_qualifiers_glsl(type, return_flags);
decl += type_to_glsl(type);
decl += type_to_array_glsl(type);
decl += " ";
if (func.self == ir.default_entry_point)
{
decl += "main";
processing_entry_point = true;
}
else
decl += to_name(func.self);
decl += "(";
SmallVector<string> arglist;
for (auto &arg : func.arguments)
{
// Do not pass in separate images or samplers if we're remapping
// to combined image samplers.
if (skip_argument(arg.id))
continue;
// Might change the variable name if it already exists in this function.
// SPIRV OpName doesn't have any semantic effect, so it's valid for an implementation
// to use same name for variables.
// Since we want to make the GLSL debuggable and somewhat sane, use fallback names for variables which are duplicates.
add_local_variable_name(arg.id);
arglist.push_back(argument_decl(arg));
// Hold a pointer to the parameter so we can invalidate the readonly field if needed.
auto *var = maybe_get<SPIRVariable>(arg.id);
if (var)
var->parameter = &arg;
}
for (auto &arg : func.shadow_arguments)
{
// Might change the variable name if it already exists in this function.
// SPIRV OpName doesn't have any semantic effect, so it's valid for an implementation
// to use same name for variables.
// Since we want to make the GLSL debuggable and somewhat sane, use fallback names for variables which are duplicates.
add_local_variable_name(arg.id);
arglist.push_back(argument_decl(arg));
// Hold a pointer to the parameter so we can invalidate the readonly field if needed.
auto *var = maybe_get<SPIRVariable>(arg.id);
if (var)
var->parameter = &arg;
}
decl += merge(arglist);
decl += ")";
statement(decl);
}
void CompilerGLSL::emit_function(SPIRFunction &func, const Bitset &return_flags)
{
// Avoid potential cycles.
if (func.active)
return;
func.active = true;
// If we depend on a function, emit that function before we emit our own function.
for (auto block : func.blocks)
{
auto &b = get<SPIRBlock>(block);
for (auto &i : b.ops)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
if (op == OpFunctionCall)
{
// Recursively emit functions which are called.
uint32_t id = ops[2];
emit_function(get<SPIRFunction>(id), ir.meta[ops[1]].decoration.decoration_flags);
}
}
}
if (func.entry_line.file_id != 0)
emit_line_directive(func.entry_line.file_id, func.entry_line.line_literal);
emit_function_prototype(func, return_flags);
begin_scope();
if (func.self == ir.default_entry_point)
emit_entry_point_declarations();
current_function = &func;
auto &entry_block = get<SPIRBlock>(func.entry_block);
sort(begin(func.constant_arrays_needed_on_stack), end(func.constant_arrays_needed_on_stack));
for (auto &array : func.constant_arrays_needed_on_stack)
{
auto &c = get<SPIRConstant>(array);
auto &type = get<SPIRType>(c.constant_type);
statement(variable_decl(type, join("_", array, "_array_copy")), " = ", constant_expression(c), ";");
}
for (auto &v : func.local_variables)
{
auto &var = get<SPIRVariable>(v);
var.deferred_declaration = false;
if (var.storage == StorageClassWorkgroup)
{
// Special variable type which cannot have initializer,
// need to be declared as standalone variables.
// Comes from MSL which can push global variables as local variables in main function.
add_local_variable_name(var.self);
statement(variable_decl(var), ";");
var.deferred_declaration = false;
}
else if (var.storage == StorageClassPrivate)
{
// These variables will not have had their CFG usage analyzed, so move it to the entry block.
// Comes from MSL which can push global variables as local variables in main function.
// We could just declare them right now, but we would miss out on an important initialization case which is
// LUT declaration in MSL.
// If we don't declare the variable when it is assigned we're forced to go through a helper function
// which copies elements one by one.
add_local_variable_name(var.self);
auto &dominated = entry_block.dominated_variables;
if (find(begin(dominated), end(dominated), var.self) == end(dominated))
entry_block.dominated_variables.push_back(var.self);
var.deferred_declaration = true;
}
else if (var.storage == StorageClassFunction && var.remapped_variable && var.static_expression)
{
// No need to declare this variable, it has a static expression.
var.deferred_declaration = false;
}
else if (expression_is_lvalue(v))
{
add_local_variable_name(var.self);
if (var.initializer)
statement(variable_decl_function_local(var), ";");
else
{
// Don't declare variable until first use to declutter the GLSL output quite a lot.
// If we don't touch the variable before first branch,
// declare it then since we need variable declaration to be in top scope.
var.deferred_declaration = true;
}
}
else
{
// HACK: SPIR-V in older glslang output likes to use samplers and images as local variables, but GLSL does not allow this.
// For these types (non-lvalue), we enforce forwarding through a shadowed variable.
// This means that when we OpStore to these variables, we just write in the expression ID directly.
// This breaks any kind of branching, since the variable must be statically assigned.
// Branching on samplers and images would be pretty much impossible to fake in GLSL.
var.statically_assigned = true;
}
var.loop_variable_enable = false;
// Loop variables are never declared outside their for-loop, so block any implicit declaration.
if (var.loop_variable)
var.deferred_declaration = false;
}
// Enforce declaration order for regression testing purposes.
for (auto &block_id : func.blocks)
{
auto &block = get<SPIRBlock>(block_id);
sort(begin(block.dominated_variables), end(block.dominated_variables));
}
for (auto &line : current_function->fixup_hooks_in)
line();
emit_block_chain(entry_block);
end_scope();
processing_entry_point = false;
statement("");
// Make sure deferred declaration state for local variables is cleared when we are done with function.
// We risk declaring Private/Workgroup variables in places we are not supposed to otherwise.
for (auto &v : func.local_variables)
{
auto &var = get<SPIRVariable>(v);
var.deferred_declaration = false;
}
}
void CompilerGLSL::emit_fixup()
{
auto &execution = get_entry_point();
if (execution.model == ExecutionModelVertex)
{
if (options.vertex.fixup_clipspace)
{
const char *suffix = backend.float_literal_suffix ? "f" : "";
statement("gl_Position.z = 2.0", suffix, " * gl_Position.z - gl_Position.w;");
}
if (options.vertex.flip_vert_y)
statement("gl_Position.y = -gl_Position.y;");
}
}
bool CompilerGLSL::flush_phi_required(uint32_t from, uint32_t to)
{
auto &child = get<SPIRBlock>(to);
for (auto &phi : child.phi_variables)
if (phi.parent == from)
return true;
return false;
}
void CompilerGLSL::flush_phi(uint32_t from, uint32_t to)
{
auto &child = get<SPIRBlock>(to);
if (child.ignore_phi_from_block == from)
return;
unordered_set<uint32_t> temporary_phi_variables;
for (auto itr = begin(child.phi_variables); itr != end(child.phi_variables); ++itr)
{
auto &phi = *itr;
if (phi.parent == from)
{
auto &var = get<SPIRVariable>(phi.function_variable);
// A Phi variable might be a loop variable, so flush to static expression.
if (var.loop_variable && !var.loop_variable_enable)
var.static_expression = phi.local_variable;
else
{
flush_variable_declaration(phi.function_variable);
// Check if we are going to write to a Phi variable that another statement will read from
// as part of another Phi node in our target block.
// For this case, we will need to copy phi.function_variable to a temporary, and use that for future reads.
// This is judged to be extremely rare, so deal with it here using a simple, but suboptimal algorithm.
bool need_saved_temporary =
find_if(itr + 1, end(child.phi_variables), [&](const SPIRBlock::Phi &future_phi) -> bool {
return future_phi.local_variable == phi.function_variable && future_phi.parent == from;
}) != end(child.phi_variables);
if (need_saved_temporary)
{
// Need to make sure we declare the phi variable with a copy at the right scope.
// We cannot safely declare a temporary here since we might be inside a continue block.
if (!var.allocate_temporary_copy)
{
var.allocate_temporary_copy = true;
force_recompile();
}
statement("_", phi.function_variable, "_copy", " = ", to_name(phi.function_variable), ";");
temporary_phi_variables.insert(phi.function_variable);
}
// This might be called in continue block, so make sure we
// use this to emit ESSL 1.0 compliant increments/decrements.
auto lhs = to_expression(phi.function_variable);
string rhs;
if (temporary_phi_variables.count(phi.local_variable))
rhs = join("_", phi.local_variable, "_copy");
else
rhs = to_pointer_expression(phi.local_variable);
if (!optimize_read_modify_write(get<SPIRType>(var.basetype), lhs, rhs))
statement(lhs, " = ", rhs, ";");
}
register_write(phi.function_variable);
}
}
}
void CompilerGLSL::branch_to_continue(uint32_t from, uint32_t to)
{
auto &to_block = get<SPIRBlock>(to);
if (from == to)
return;
assert(is_continue(to));
if (to_block.complex_continue)
{
// Just emit the whole block chain as is.
auto usage_counts = expression_usage_counts;
auto invalid = invalid_expressions;
emit_block_chain(to_block);
// Expression usage counts and invalid expressions
// are moot after returning from the continue block.
// Since we emit the same block multiple times,
// we don't want to invalidate ourselves.
expression_usage_counts = usage_counts;
invalid_expressions = invalid;
}
else
{
auto &from_block = get<SPIRBlock>(from);
bool outside_control_flow = false;
uint32_t loop_dominator = 0;
// FIXME: Refactor this to not use the old loop_dominator tracking.
if (from_block.merge_block)
{
// If we are a loop header, we don't set the loop dominator,
// so just use "self" here.
loop_dominator = from;
}
else if (from_block.loop_dominator != SPIRBlock::NoDominator)
{
loop_dominator = from_block.loop_dominator;
}
if (loop_dominator != 0)
{
auto &dominator = get<SPIRBlock>(loop_dominator);
// For non-complex continue blocks, we implicitly branch to the continue block
// by having the continue block be part of the loop header in for (; ; continue-block).
outside_control_flow = block_is_outside_flow_control_from_block(dominator, from_block);
}
// Some simplification for for-loops. We always end up with a useless continue;
// statement since we branch to a loop block.
// Walk the CFG, if we uncoditionally execute the block calling continue assuming we're in the loop block,
// we can avoid writing out an explicit continue statement.
// Similar optimization to return statements if we know we're outside flow control.
if (!outside_control_flow)
statement("continue;");
}
}
void CompilerGLSL::branch(uint32_t from, uint32_t to)
{
flush_phi(from, to);
flush_control_dependent_expressions(from);
flush_all_active_variables();
// This is only a continue if we branch to our loop dominator.
if ((ir.block_meta[to] & ParsedIR::BLOCK_META_LOOP_HEADER_BIT) != 0 && get<SPIRBlock>(from).loop_dominator == to)
{
// This can happen if we had a complex continue block which was emitted.
// Once the continue block tries to branch to the loop header, just emit continue;
// and end the chain here.
statement("continue;");
}
else if (is_break(to))
{
// Very dirty workaround.
// Switch constructs are able to break, but they cannot break out of a loop at the same time.
// Only sensible solution is to make a ladder variable, which we declare at the top of the switch block,
// write to the ladder here, and defer the break.
// The loop we're breaking out of must dominate the switch block, or there is no ladder breaking case.
if (current_emitting_switch && is_loop_break(to) && current_emitting_switch->loop_dominator != ~0u &&
get<SPIRBlock>(current_emitting_switch->loop_dominator).merge_block == to)
{
if (!current_emitting_switch->need_ladder_break)
{
force_recompile();
current_emitting_switch->need_ladder_break = true;
}
statement("_", current_emitting_switch->self, "_ladder_break = true;");
}
statement("break;");
}
else if (is_continue(to) || (from == to))
{
// For from == to case can happen for a do-while loop which branches into itself.
// We don't mark these cases as continue blocks, but the only possible way to branch into
// ourselves is through means of continue blocks.
branch_to_continue(from, to);
}
else if (!is_conditional(to))
emit_block_chain(get<SPIRBlock>(to));
// It is important that we check for break before continue.
// A block might serve two purposes, a break block for the inner scope, and
// a continue block in the outer scope.
// Inner scope always takes precedence.
}
void CompilerGLSL::branch(uint32_t from, uint32_t cond, uint32_t true_block, uint32_t false_block)
{
// If we branch directly to a selection merge target, we don't really need a code path.
bool true_sub = !is_conditional(true_block);
bool false_sub = !is_conditional(false_block);
if (true_sub)
{
emit_block_hints(get<SPIRBlock>(from));
statement("if (", to_expression(cond), ")");
begin_scope();
branch(from, true_block);
end_scope();
if (false_sub || is_continue(false_block) || is_break(false_block))
{
statement("else");
begin_scope();
branch(from, false_block);
end_scope();
}
else if (flush_phi_required(from, false_block))
{
statement("else");
begin_scope();
flush_phi(from, false_block);
end_scope();
}
}
else if (false_sub && !true_sub)
{
// Only need false path, use negative conditional.
emit_block_hints(get<SPIRBlock>(from));
statement("if (!", to_enclosed_expression(cond), ")");
begin_scope();
branch(from, false_block);
end_scope();
if (is_continue(true_block) || is_break(true_block))
{
statement("else");
begin_scope();
branch(from, true_block);
end_scope();
}
else if (flush_phi_required(from, true_block))
{
statement("else");
begin_scope();
flush_phi(from, true_block);
end_scope();
}
}
}
// FIXME: This currently cannot handle complex continue blocks
// as in do-while.
// This should be seen as a "trivial" continue block.
string CompilerGLSL::emit_continue_block(uint32_t continue_block, bool follow_true_block, bool follow_false_block)
{
auto *block = &get<SPIRBlock>(continue_block);
// While emitting the continue block, declare_temporary will check this
// if we have to emit temporaries.
current_continue_block = block;
SmallVector<string> statements;
// Capture all statements into our list.
auto *old = redirect_statement;
redirect_statement = &statements;
// Stamp out all blocks one after each other.
while ((ir.block_meta[block->self] & ParsedIR::BLOCK_META_LOOP_HEADER_BIT) == 0)
{
// Write out all instructions we have in this block.
emit_block_instructions(*block);
// For plain branchless for/while continue blocks.
if (block->next_block)
{
flush_phi(continue_block, block->next_block);
block = &get<SPIRBlock>(block->next_block);
}
// For do while blocks. The last block will be a select block.
else if (block->true_block && follow_true_block)
{
flush_phi(continue_block, block->true_block);
block = &get<SPIRBlock>(block->true_block);
}
else if (block->false_block && follow_false_block)
{
flush_phi(continue_block, block->false_block);
block = &get<SPIRBlock>(block->false_block);
}
else
{
SPIRV_CROSS_THROW("Invalid continue block detected!");
}
}
// Restore old pointer.
redirect_statement = old;
// Somewhat ugly, strip off the last ';' since we use ',' instead.
// Ideally, we should select this behavior in statement().
for (auto &s : statements)
{
if (!s.empty() && s.back() == ';')
s.erase(s.size() - 1, 1);
}
current_continue_block = nullptr;
return merge(statements);
}
void CompilerGLSL::emit_while_loop_initializers(const SPIRBlock &block)
{
// While loops do not take initializers, so declare all of them outside.
for (auto &loop_var : block.loop_variables)
{
auto &var = get<SPIRVariable>(loop_var);
statement(variable_decl(var), ";");
}
}
string CompilerGLSL::emit_for_loop_initializers(const SPIRBlock &block)
{
if (block.loop_variables.empty())
return "";
bool same_types = for_loop_initializers_are_same_type(block);
// We can only declare for loop initializers if all variables are of same type.
// If we cannot do this, declare individual variables before the loop header.
// We might have a loop variable candidate which was not assigned to for some reason.
uint32_t missing_initializers = 0;
for (auto &variable : block.loop_variables)
{
uint32_t expr = get<SPIRVariable>(variable).static_expression;
// Sometimes loop variables are initialized with OpUndef, but we can just declare
// a plain variable without initializer in this case.
if (expr == 0 || ir.ids[expr].get_type() == TypeUndef)
missing_initializers++;
}
if (block.loop_variables.size() == 1 && missing_initializers == 0)
{
return variable_decl(get<SPIRVariable>(block.loop_variables.front()));
}
else if (!same_types || missing_initializers == uint32_t(block.loop_variables.size()))
{
for (auto &loop_var : block.loop_variables)
statement(variable_decl(get<SPIRVariable>(loop_var)), ";");
return "";
}
else
{
// We have a mix of loop variables, either ones with a clear initializer, or ones without.
// Separate the two streams.
string expr;
for (auto &loop_var : block.loop_variables)
{
uint32_t static_expr = get<SPIRVariable>(loop_var).static_expression;
if (static_expr == 0 || ir.ids[static_expr].get_type() == TypeUndef)
{
statement(variable_decl(get<SPIRVariable>(loop_var)), ";");
}
else
{
auto &var = get<SPIRVariable>(loop_var);
auto &type = get_variable_data_type(var);
if (expr.empty())
{
// For loop initializers are of the form <type id = value, id = value, id = value, etc ...
expr = join(to_qualifiers_glsl(var.self), type_to_glsl(type), " ");
}
else
{
expr += ", ";
// In MSL, being based on C++, the asterisk marking a pointer
// binds to the identifier, not the type.
if (type.pointer)
expr += "* ";
}
expr += join(to_name(loop_var), " = ", to_pointer_expression(var.static_expression));
}
}
return expr;
}
}
bool CompilerGLSL::for_loop_initializers_are_same_type(const SPIRBlock &block)
{
if (block.loop_variables.size() <= 1)
return true;
uint32_t expected = 0;
Bitset expected_flags;
for (auto &var : block.loop_variables)
{
// Don't care about uninitialized variables as they will not be part of the initializers.
uint32_t expr = get<SPIRVariable>(var).static_expression;
if (expr == 0 || ir.ids[expr].get_type() == TypeUndef)
continue;
if (expected == 0)
{
expected = get<SPIRVariable>(var).basetype;
expected_flags = get_decoration_bitset(var);
}
else if (expected != get<SPIRVariable>(var).basetype)
return false;
// Precision flags and things like that must also match.
if (expected_flags != get_decoration_bitset(var))
return false;
}
return true;
}
bool CompilerGLSL::attempt_emit_loop_header(SPIRBlock &block, SPIRBlock::Method method)
{
SPIRBlock::ContinueBlockType continue_type = continue_block_type(get<SPIRBlock>(block.continue_block));
if (method == SPIRBlock::MergeToSelectForLoop || method == SPIRBlock::MergeToSelectContinueForLoop)
{
uint32_t current_count = statement_count;
// If we're trying to create a true for loop,
// we need to make sure that all opcodes before branch statement do not actually emit any code.
// We can then take the condition expression and create a for (; cond ; ) { body; } structure instead.
emit_block_instructions(block);
bool condition_is_temporary = forced_temporaries.find(block.condition) == end(forced_temporaries);
// This can work! We only did trivial things which could be forwarded in block body!
if (current_count == statement_count && condition_is_temporary)
{
switch (continue_type)
{
case SPIRBlock::ForLoop:
{
// This block may be a dominating block, so make sure we flush undeclared variables before building the for loop header.
flush_undeclared_variables(block);
// Important that we do this in this order because
// emitting the continue block can invalidate the condition expression.
auto initializer = emit_for_loop_initializers(block);
auto condition = to_expression(block.condition);
// Condition might have to be inverted.
if (execution_is_noop(get<SPIRBlock>(block.true_block), get<SPIRBlock>(block.merge_block)))
condition = join("!", enclose_expression(condition));
emit_block_hints(block);
if (method != SPIRBlock::MergeToSelectContinueForLoop)
{
auto continue_block = emit_continue_block(block.continue_block, false, false);
statement("for (", initializer, "; ", condition, "; ", continue_block, ")");
}
else
statement("for (", initializer, "; ", condition, "; )");
break;
}
case SPIRBlock::WhileLoop:
{
// This block may be a dominating block, so make sure we flush undeclared variables before building the while loop header.
flush_undeclared_variables(block);
emit_while_loop_initializers(block);
emit_block_hints(block);
auto condition = to_expression(block.condition);
// Condition might have to be inverted.
if (execution_is_noop(get<SPIRBlock>(block.true_block), get<SPIRBlock>(block.merge_block)))
condition = join("!", enclose_expression(condition));
statement("while (", condition, ")");
break;
}
default:
block.disable_block_optimization = true;
force_recompile();
begin_scope(); // We'll see an end_scope() later.
return false;
}
begin_scope();
return true;
}
else
{
block.disable_block_optimization = true;
force_recompile();
begin_scope(); // We'll see an end_scope() later.
return false;
}
}
else if (method == SPIRBlock::MergeToDirectForLoop)
{
auto &child = get<SPIRBlock>(block.next_block);
// This block may be a dominating block, so make sure we flush undeclared variables before building the for loop header.
flush_undeclared_variables(child);
uint32_t current_count = statement_count;
// If we're trying to create a true for loop,
// we need to make sure that all opcodes before branch statement do not actually emit any code.
// We can then take the condition expression and create a for (; cond ; ) { body; } structure instead.
emit_block_instructions(child);
bool condition_is_temporary = forced_temporaries.find(child.condition) == end(forced_temporaries);
if (current_count == statement_count && condition_is_temporary)
{
uint32_t target_block = child.true_block;
switch (continue_type)
{
case SPIRBlock::ForLoop:
{
// Important that we do this in this order because
// emitting the continue block can invalidate the condition expression.
auto initializer = emit_for_loop_initializers(block);
auto condition = to_expression(child.condition);
// Condition might have to be inverted.
if (execution_is_noop(get<SPIRBlock>(child.true_block), get<SPIRBlock>(block.merge_block)))
{
condition = join("!", enclose_expression(condition));
target_block = child.false_block;
}
auto continue_block = emit_continue_block(block.continue_block, false, false);
emit_block_hints(block);
statement("for (", initializer, "; ", condition, "; ", continue_block, ")");
break;
}
case SPIRBlock::WhileLoop:
{
emit_while_loop_initializers(block);
emit_block_hints(block);
auto condition = to_expression(child.condition);
// Condition might have to be inverted.
if (execution_is_noop(get<SPIRBlock>(child.true_block), get<SPIRBlock>(block.merge_block)))
{
condition = join("!", enclose_expression(condition));
target_block = child.false_block;
}
statement("while (", condition, ")");
break;
}
default:
block.disable_block_optimization = true;
force_recompile();
begin_scope(); // We'll see an end_scope() later.
return false;
}
begin_scope();
branch(child.self, target_block);
return true;
}
else
{
block.disable_block_optimization = true;
force_recompile();
begin_scope(); // We'll see an end_scope() later.
return false;
}
}
else
return false;
}
void CompilerGLSL::flush_undeclared_variables(SPIRBlock &block)
{
for (auto &v : block.dominated_variables)
flush_variable_declaration(v);
}
void CompilerGLSL::emit_hoisted_temporaries(SmallVector<pair<uint32_t, uint32_t>> &temporaries)
{
// If we need to force temporaries for certain IDs due to continue blocks, do it before starting loop header.
// Need to sort these to ensure that reference output is stable.
sort(begin(temporaries), end(temporaries),
[](const pair<uint32_t, uint32_t> &a, const pair<uint32_t, uint32_t> &b) { return a.second < b.second; });
for (auto &tmp : temporaries)
{
add_local_variable_name(tmp.second);
auto &flags = ir.meta[tmp.second].decoration.decoration_flags;
auto &type = get<SPIRType>(tmp.first);
statement(flags_to_qualifiers_glsl(type, flags), variable_decl(type, to_name(tmp.second)), ";");
hoisted_temporaries.insert(tmp.second);
forced_temporaries.insert(tmp.second);
// The temporary might be read from before it's assigned, set up the expression now.
set<SPIRExpression>(tmp.second, to_name(tmp.second), tmp.first, true);
}
}
void CompilerGLSL::emit_block_chain(SPIRBlock &block)
{
bool select_branch_to_true_block = false;
bool select_branch_to_false_block = false;
bool skip_direct_branch = false;
bool emitted_loop_header_variables = false;
bool force_complex_continue_block = false;
emit_hoisted_temporaries(block.declare_temporary);
SPIRBlock::ContinueBlockType continue_type = SPIRBlock::ContinueNone;
if (block.continue_block)
continue_type = continue_block_type(get<SPIRBlock>(block.continue_block));
// If we have loop variables, stop masking out access to the variable now.
for (auto var_id : block.loop_variables)
{
auto &var = get<SPIRVariable>(var_id);
var.loop_variable_enable = true;
// We're not going to declare the variable directly, so emit a copy here.
emit_variable_temporary_copies(var);
}
// Remember deferred declaration state. We will restore it before returning.
SmallVector<bool, 64> rearm_dominated_variables(block.dominated_variables.size());
for (size_t i = 0; i < block.dominated_variables.size(); i++)
{
uint32_t var_id = block.dominated_variables[i];
auto &var = get<SPIRVariable>(var_id);
rearm_dominated_variables[i] = var.deferred_declaration;
}
// This is the method often used by spirv-opt to implement loops.
// The loop header goes straight into the continue block.
// However, don't attempt this on ESSL 1.0, because if a loop variable is used in a continue block,
// it *MUST* be used in the continue block. This loop method will not work.
if (!is_legacy_es() && block_is_loop_candidate(block, SPIRBlock::MergeToSelectContinueForLoop))
{
flush_undeclared_variables(block);
if (attempt_emit_loop_header(block, SPIRBlock::MergeToSelectContinueForLoop))
{
if (execution_is_noop(get<SPIRBlock>(block.true_block), get<SPIRBlock>(block.merge_block)))
select_branch_to_false_block = true;
else
select_branch_to_true_block = true;
emitted_loop_header_variables = true;
force_complex_continue_block = true;
}
}
// This is the older loop behavior in glslang which branches to loop body directly from the loop header.
else if (block_is_loop_candidate(block, SPIRBlock::MergeToSelectForLoop))
{
flush_undeclared_variables(block);
if (attempt_emit_loop_header(block, SPIRBlock::MergeToSelectForLoop))
{
// The body of while, is actually just the true (or false) block, so always branch there unconditionally.
if (execution_is_noop(get<SPIRBlock>(block.true_block), get<SPIRBlock>(block.merge_block)))
select_branch_to_false_block = true;
else
select_branch_to_true_block = true;
emitted_loop_header_variables = true;
}
}
// This is the newer loop behavior in glslang which branches from Loop header directly to
// a new block, which in turn has a OpBranchSelection without a selection merge.
else if (block_is_loop_candidate(block, SPIRBlock::MergeToDirectForLoop))
{
flush_undeclared_variables(block);
if (attempt_emit_loop_header(block, SPIRBlock::MergeToDirectForLoop))
{
skip_direct_branch = true;
emitted_loop_header_variables = true;
}
}
else if (continue_type == SPIRBlock::DoWhileLoop)
{
flush_undeclared_variables(block);
emit_while_loop_initializers(block);
emitted_loop_header_variables = true;
// We have some temporaries where the loop header is the dominator.
// We risk a case where we have code like:
// for (;;) { create-temporary; break; } consume-temporary;
// so force-declare temporaries here.
emit_hoisted_temporaries(block.potential_declare_temporary);
statement("do");
begin_scope();
emit_block_instructions(block);
}
else if (block.merge == SPIRBlock::MergeLoop)
{
flush_undeclared_variables(block);
emit_while_loop_initializers(block);
emitted_loop_header_variables = true;
// We have a generic loop without any distinguishable pattern like for, while or do while.
get<SPIRBlock>(block.continue_block).complex_continue = true;
continue_type = SPIRBlock::ComplexLoop;
// We have some temporaries where the loop header is the dominator.
// We risk a case where we have code like:
// for (;;) { create-temporary; break; } consume-temporary;
// so force-declare temporaries here.
emit_hoisted_temporaries(block.potential_declare_temporary);
statement("for (;;)");
begin_scope();
emit_block_instructions(block);
}
else
{
emit_block_instructions(block);
}
// If we didn't successfully emit a loop header and we had loop variable candidates, we have a problem
// as writes to said loop variables might have been masked out, we need a recompile.
if (!emitted_loop_header_variables && !block.loop_variables.empty())
{
force_recompile();
for (auto var : block.loop_variables)
get<SPIRVariable>(var).loop_variable = false;
block.loop_variables.clear();
}
flush_undeclared_variables(block);
bool emit_next_block = true;
// Handle end of block.
switch (block.terminator)
{
case SPIRBlock::Direct:
// True when emitting complex continue block.
if (block.loop_dominator == block.next_block)
{
branch(block.self, block.next_block);
emit_next_block = false;
}
// True if MergeToDirectForLoop succeeded.
else if (skip_direct_branch)
emit_next_block = false;
else if (is_continue(block.next_block) || is_break(block.next_block) || is_conditional(block.next_block))
{
branch(block.self, block.next_block);
emit_next_block = false;
}
break;
case SPIRBlock::Select:
// True if MergeToSelectForLoop or MergeToSelectContinueForLoop succeeded.
if (select_branch_to_true_block)
{
if (force_complex_continue_block)
{
assert(block.true_block == block.continue_block);
// We're going to emit a continue block directly here, so make sure it's marked as complex.
auto &complex_continue = get<SPIRBlock>(block.continue_block).complex_continue;
bool old_complex = complex_continue;
complex_continue = true;
branch(block.self, block.true_block);
complex_continue = old_complex;
}
else
branch(block.self, block.true_block);
}
else if (select_branch_to_false_block)
{
if (force_complex_continue_block)
{
assert(block.false_block == block.continue_block);
// We're going to emit a continue block directly here, so make sure it's marked as complex.
auto &complex_continue = get<SPIRBlock>(block.continue_block).complex_continue;
bool old_complex = complex_continue;
complex_continue = true;
branch(block.self, block.false_block);
complex_continue = old_complex;
}
else
branch(block.self, block.false_block);
}
else
branch(block.self, block.condition, block.true_block, block.false_block);
break;
case SPIRBlock::MultiSelect:
{
auto &type = expression_type(block.condition);
bool unsigned_case =
type.basetype == SPIRType::UInt || type.basetype == SPIRType::UShort || type.basetype == SPIRType::UByte;
if (block.merge == SPIRBlock::MergeNone)
SPIRV_CROSS_THROW("Switch statement is not structured");
if (type.basetype == SPIRType::UInt64 || type.basetype == SPIRType::Int64)
{
// SPIR-V spec suggests this is allowed, but we cannot support it in higher level languages.
SPIRV_CROSS_THROW("Cannot use 64-bit switch selectors.");
}
const char *label_suffix = "";
if (type.basetype == SPIRType::UInt && backend.uint32_t_literal_suffix)
label_suffix = "u";
else if (type.basetype == SPIRType::UShort)
label_suffix = backend.uint16_t_literal_suffix;
else if (type.basetype == SPIRType::Short)
label_suffix = backend.int16_t_literal_suffix;
SPIRBlock *old_emitting_switch = current_emitting_switch;
current_emitting_switch = █
if (block.need_ladder_break)
statement("bool _", block.self, "_ladder_break = false;");
// Find all unique case constructs.
unordered_map<uint32_t, SmallVector<uint32_t>> case_constructs;
SmallVector<uint32_t> block_declaration_order;
SmallVector<uint32_t> literals_to_merge;
// If a switch case branches to the default block for some reason, we can just remove that literal from consideration
// and let the default: block handle it.
// 2.11 in SPIR-V spec states that for fall-through cases, there is a very strict declaration order which we can take advantage of here.
// We only need to consider possible fallthrough if order[i] branches to order[i + 1].
for (auto &c : block.cases)
{
if (c.block != block.next_block && c.block != block.default_block)
{
if (!case_constructs.count(c.block))
block_declaration_order.push_back(c.block);
case_constructs[c.block].push_back(c.value);
}
else if (c.block == block.next_block && block.default_block != block.next_block)
{
// We might have to flush phi inside specific case labels.
// If we can piggyback on default:, do so instead.
literals_to_merge.push_back(c.value);
}
}
// Empty literal array -> default.
if (block.default_block != block.next_block)
{
auto &default_block = get<SPIRBlock>(block.default_block);
// We need to slide in the default block somewhere in this chain
// if there are fall-through scenarios since the default is declared separately in OpSwitch.
// Only consider trivial fall-through cases here.
size_t num_blocks = block_declaration_order.size();
bool injected_block = false;
for (size_t i = 0; i < num_blocks; i++)
{
auto &case_block = get<SPIRBlock>(block_declaration_order[i]);
if (execution_is_direct_branch(case_block, default_block))
{
// Fallthrough to default block, we must inject the default block here.
block_declaration_order.insert(begin(block_declaration_order) + i + 1, block.default_block);
injected_block = true;
break;
}
else if (execution_is_direct_branch(default_block, case_block))
{
// Default case is falling through to another case label, we must inject the default block here.
block_declaration_order.insert(begin(block_declaration_order) + i, block.default_block);
injected_block = true;
break;
}
}
// Order does not matter.
if (!injected_block)
block_declaration_order.push_back(block.default_block);
case_constructs[block.default_block] = {};
}
size_t num_blocks = block_declaration_order.size();
const auto to_case_label = [](uint32_t literal, bool is_unsigned_case) -> string {
return is_unsigned_case ? convert_to_string(literal) : convert_to_string(int32_t(literal));
};
// We need to deal with a complex scenario for OpPhi. If we have case-fallthrough and Phi in the picture,
// we need to flush phi nodes outside the switch block in a branch,
// and skip any Phi handling inside the case label to make fall-through work as expected.
// This kind of code-gen is super awkward and it's a last resort. Normally we would want to handle this
// inside the case label if at all possible.
for (size_t i = 1; i < num_blocks; i++)
{
if (flush_phi_required(block.self, block_declaration_order[i]) &&
flush_phi_required(block_declaration_order[i - 1], block_declaration_order[i]))
{
uint32_t target_block = block_declaration_order[i];
// Make sure we flush Phi, it might have been marked to be ignored earlier.
get<SPIRBlock>(target_block).ignore_phi_from_block = 0;
auto &literals = case_constructs[target_block];
if (literals.empty())
{
// Oh boy, gotta make a complete negative test instead! o.o
// Find all possible literals that would *not* make us enter the default block.
// If none of those literals match, we flush Phi ...
SmallVector<string> conditions;
for (size_t j = 0; j < num_blocks; j++)
{
auto &negative_literals = case_constructs[block_declaration_order[j]];
for (auto &case_label : negative_literals)
conditions.push_back(join(to_enclosed_expression(block.condition),
" != ", to_case_label(case_label, unsigned_case)));
}
statement("if (", merge(conditions, " && "), ")");
begin_scope();
flush_phi(block.self, target_block);
end_scope();
}
else
{
SmallVector<string> conditions;
conditions.reserve(literals.size());
for (auto &case_label : literals)
conditions.push_back(join(to_enclosed_expression(block.condition),
" == ", to_case_label(case_label, unsigned_case)));
statement("if (", merge(conditions, " || "), ")");
begin_scope();
flush_phi(block.self, target_block);
end_scope();
}
// Mark the block so that we don't flush Phi from header to case label.
get<SPIRBlock>(target_block).ignore_phi_from_block = block.self;
}
}
emit_block_hints(block);
statement("switch (", to_expression(block.condition), ")");
begin_scope();
for (size_t i = 0; i < num_blocks; i++)
{
uint32_t target_block = block_declaration_order[i];
auto &literals = case_constructs[target_block];
if (literals.empty())
{
// Default case.
statement("default:");
}
else
{
for (auto &case_literal : literals)
{
// The case label value must be sign-extended properly in SPIR-V, so we can assume 32-bit values here.
statement("case ", to_case_label(case_literal, unsigned_case), label_suffix, ":");
}
}
auto &case_block = get<SPIRBlock>(target_block);
if (backend.support_case_fallthrough && i + 1 < num_blocks &&
execution_is_direct_branch(case_block, get<SPIRBlock>(block_declaration_order[i + 1])))
{
// We will fall through here, so just terminate the block chain early.
// We still need to deal with Phi potentially.
// No need for a stack-like thing here since we only do fall-through when there is a
// single trivial branch to fall-through target..
current_emitting_switch_fallthrough = true;
}
else
current_emitting_switch_fallthrough = false;
begin_scope();
branch(block.self, target_block);
end_scope();
current_emitting_switch_fallthrough = false;
}
// Might still have to flush phi variables if we branch from loop header directly to merge target.
if (flush_phi_required(block.self, block.next_block))
{
if (block.default_block == block.next_block || !literals_to_merge.empty())
{
for (auto &case_literal : literals_to_merge)
statement("case ", to_case_label(case_literal, unsigned_case), label_suffix, ":");
if (block.default_block == block.next_block)
statement("default:");
begin_scope();
flush_phi(block.self, block.next_block);
statement("break;");
end_scope();
}
}
end_scope();
if (block.need_ladder_break)
{
statement("if (_", block.self, "_ladder_break)");
begin_scope();
statement("break;");
end_scope();
}
current_emitting_switch = old_emitting_switch;
break;
}
case SPIRBlock::Return:
for (auto &line : current_function->fixup_hooks_out)
line();
if (processing_entry_point)
emit_fixup();
if (block.return_value)
{
auto &type = expression_type(block.return_value);
if (!type.array.empty() && !backend.can_return_array)
{
// If we cannot return arrays, we will have a special out argument we can write to instead.
// The backend is responsible for setting this up, and redirection the return values as appropriate.
if (ir.ids[block.return_value].get_type() != TypeUndef)
emit_array_copy("SPIRV_Cross_return_value", block.return_value);
if (!block_is_outside_flow_control_from_block(get<SPIRBlock>(current_function->entry_block), block) ||
block.loop_dominator != SPIRBlock::NoDominator)
{
statement("return;");
}
}
else
{
// OpReturnValue can return Undef, so don't emit anything for this case.
if (ir.ids[block.return_value].get_type() != TypeUndef)
statement("return ", to_expression(block.return_value), ";");
}
}
// If this block is the very final block and not called from control flow,
// we do not need an explicit return which looks out of place. Just end the function here.
// In the very weird case of for(;;) { return; } executing return is unconditional,
// but we actually need a return here ...
else if (!block_is_outside_flow_control_from_block(get<SPIRBlock>(current_function->entry_block), block) ||
block.loop_dominator != SPIRBlock::NoDominator)
{
statement("return;");
}
break;
case SPIRBlock::Kill:
statement(backend.discard_literal, ";");
break;
case SPIRBlock::Unreachable:
emit_next_block = false;
break;
default:
SPIRV_CROSS_THROW("Unimplemented block terminator.");
}
if (block.next_block && emit_next_block)
{
// If we hit this case, we're dealing with an unconditional branch, which means we will output
// that block after this. If we had selection merge, we already flushed phi variables.
if (block.merge != SPIRBlock::MergeSelection)
flush_phi(block.self, block.next_block);
// For switch fallthrough cases, we terminate the chain here, but we still need to handle Phi.
if (!current_emitting_switch_fallthrough)
{
// For merge selects we might have ignored the fact that a merge target
// could have been a break; or continue;
// We will need to deal with it here.
if (is_loop_break(block.next_block))
{
// Cannot check for just break, because switch statements will also use break.
assert(block.merge == SPIRBlock::MergeSelection);
statement("break;");
}
else if (is_continue(block.next_block))
{
assert(block.merge == SPIRBlock::MergeSelection);
branch_to_continue(block.self, block.next_block);
}
else if (block.self != block.next_block)
emit_block_chain(get<SPIRBlock>(block.next_block));
}
}
if (block.merge == SPIRBlock::MergeLoop)
{
if (continue_type == SPIRBlock::DoWhileLoop)
{
// Make sure that we run the continue block to get the expressions set, but this
// should become an empty string.
// We have no fallbacks if we cannot forward everything to temporaries ...
const auto &continue_block = get<SPIRBlock>(block.continue_block);
bool positive_test = execution_is_noop(get<SPIRBlock>(continue_block.true_block),
get<SPIRBlock>(continue_block.loop_dominator));
uint32_t current_count = statement_count;
auto statements = emit_continue_block(block.continue_block, positive_test, !positive_test);
if (statement_count != current_count)
{
// The DoWhile block has side effects, force ComplexLoop pattern next pass.
get<SPIRBlock>(block.continue_block).complex_continue = true;
force_recompile();
}
// Might have to invert the do-while test here.
auto condition = to_expression(continue_block.condition);
if (!positive_test)
condition = join("!", enclose_expression(condition));
end_scope_decl(join("while (", condition, ")"));
}
else
end_scope();
// We cannot break out of two loops at once, so don't check for break; here.
// Using block.self as the "from" block isn't quite right, but it has the same scope
// and dominance structure, so it's fine.
if (is_continue(block.merge_block))
branch_to_continue(block.self, block.merge_block);
else
emit_block_chain(get<SPIRBlock>(block.merge_block));
}
// Forget about control dependent expressions now.
block.invalidate_expressions.clear();
// After we return, we must be out of scope, so if we somehow have to re-emit this function,
// re-declare variables if necessary.
assert(rearm_dominated_variables.size() == block.dominated_variables.size());
for (size_t i = 0; i < block.dominated_variables.size(); i++)
{
uint32_t var = block.dominated_variables[i];
get<SPIRVariable>(var).deferred_declaration = rearm_dominated_variables[i];
}
// Just like for deferred declaration, we need to forget about loop variable enable
// if our block chain is reinstantiated later.
for (auto &var_id : block.loop_variables)
get<SPIRVariable>(var_id).loop_variable_enable = false;
}
void CompilerGLSL::begin_scope()
{
statement("{");
indent++;
}
void CompilerGLSL::end_scope()
{
if (!indent)
SPIRV_CROSS_THROW("Popping empty indent stack.");
indent--;
statement("}");
}
void CompilerGLSL::end_scope_decl()
{
if (!indent)
SPIRV_CROSS_THROW("Popping empty indent stack.");
indent--;
statement("};");
}
void CompilerGLSL::end_scope_decl(const string &decl)
{
if (!indent)
SPIRV_CROSS_THROW("Popping empty indent stack.");
indent--;
statement("} ", decl, ";");
}
void CompilerGLSL::check_function_call_constraints(const uint32_t *args, uint32_t length)
{
// If our variable is remapped, and we rely on type-remapping information as
// well, then we cannot pass the variable as a function parameter.
// Fixing this is non-trivial without stamping out variants of the same function,
// so for now warn about this and suggest workarounds instead.
for (uint32_t i = 0; i < length; i++)
{
auto *var = maybe_get<SPIRVariable>(args[i]);
if (!var || !var->remapped_variable)
continue;
auto &type = get<SPIRType>(var->basetype);
if (type.basetype == SPIRType::Image && type.image.dim == DimSubpassData)
{
SPIRV_CROSS_THROW("Tried passing a remapped subpassInput variable to a function. "
"This will not work correctly because type-remapping information is lost. "
"To workaround, please consider not passing the subpass input as a function parameter, "
"or use in/out variables instead which do not need type remapping information.");
}
}
}
const Instruction *CompilerGLSL::get_next_instruction_in_block(const Instruction &instr)
{
// FIXME: This is kind of hacky. There should be a cleaner way.
auto offset = uint32_t(&instr - current_emitting_block->ops.data());
if ((offset + 1) < current_emitting_block->ops.size())
return ¤t_emitting_block->ops[offset + 1];
else
return nullptr;
}
uint32_t CompilerGLSL::mask_relevant_memory_semantics(uint32_t semantics)
{
return semantics & (MemorySemanticsAtomicCounterMemoryMask | MemorySemanticsImageMemoryMask |
MemorySemanticsWorkgroupMemoryMask | MemorySemanticsUniformMemoryMask |
MemorySemanticsCrossWorkgroupMemoryMask | MemorySemanticsSubgroupMemoryMask);
}
void CompilerGLSL::emit_array_copy(const string &lhs, uint32_t rhs_id)
{
statement(lhs, " = ", to_expression(rhs_id), ";");
}
void CompilerGLSL::unroll_array_from_complex_load(uint32_t target_id, uint32_t source_id, std::string &expr)
{
if (!backend.force_gl_in_out_block)
return;
// This path is only relevant for GL backends.
auto *var = maybe_get<SPIRVariable>(source_id);
if (!var)
return;
if (var->storage != StorageClassInput)
return;
auto &type = get_variable_data_type(*var);
if (type.array.empty())
return;
auto builtin = BuiltIn(get_decoration(var->self, DecorationBuiltIn));
bool is_builtin = is_builtin_variable(*var) && (builtin == BuiltInPointSize || builtin == BuiltInPosition);
bool is_tess = is_tessellation_shader();
// Tessellation input arrays are special in that they are unsized, so we cannot directly copy from it.
// We must unroll the array load.
// For builtins, we couldn't catch this case normally,
// because this is resolved in the OpAccessChain in most cases.
// If we load the entire array, we have no choice but to unroll here.
if (is_builtin || is_tess)
{
auto new_expr = join("_", target_id, "_unrolled");
statement(variable_decl(type, new_expr, target_id), ";");
string array_expr;
if (type.array_size_literal.front())
{
array_expr = convert_to_string(type.array.front());
if (type.array.front() == 0)
SPIRV_CROSS_THROW("Cannot unroll an array copy from unsized array.");
}
else
array_expr = to_expression(type.array.front());
// The array size might be a specialization constant, so use a for-loop instead.
statement("for (int i = 0; i < int(", array_expr, "); i++)");
begin_scope();
if (is_builtin)
statement(new_expr, "[i] = gl_in[i].", expr, ";");
else
statement(new_expr, "[i] = ", expr, "[i];");
end_scope();
expr = move(new_expr);
}
}
void CompilerGLSL::bitcast_from_builtin_load(uint32_t source_id, std::string &expr, const SPIRType &expr_type)
{
auto *var = maybe_get_backing_variable(source_id);
if (var)
source_id = var->self;
// Only interested in standalone builtin variables.
if (!has_decoration(source_id, DecorationBuiltIn))
return;
auto builtin = static_cast<BuiltIn>(get_decoration(source_id, DecorationBuiltIn));
auto expected_type = expr_type.basetype;
// TODO: Fill in for more builtins.
switch (builtin)
{
case BuiltInLayer:
case BuiltInPrimitiveId:
case BuiltInViewportIndex:
case BuiltInInstanceId:
case BuiltInInstanceIndex:
case BuiltInVertexId:
case BuiltInVertexIndex:
case BuiltInSampleId:
case BuiltInBaseVertex:
case BuiltInBaseInstance:
case BuiltInDrawIndex:
case BuiltInFragStencilRefEXT:
expected_type = SPIRType::Int;
break;
case BuiltInGlobalInvocationId:
case BuiltInLocalInvocationId:
case BuiltInWorkgroupId:
case BuiltInLocalInvocationIndex:
case BuiltInWorkgroupSize:
case BuiltInNumWorkgroups:
expected_type = SPIRType::UInt;
break;
default:
break;
}
if (expected_type != expr_type.basetype)
expr = bitcast_expression(expr_type, expected_type, expr);
}
void CompilerGLSL::bitcast_to_builtin_store(uint32_t target_id, std::string &expr, const SPIRType &expr_type)
{
// Only interested in standalone builtin variables.
if (!has_decoration(target_id, DecorationBuiltIn))
return;
auto builtin = static_cast<BuiltIn>(get_decoration(target_id, DecorationBuiltIn));
auto expected_type = expr_type.basetype;
// TODO: Fill in for more builtins.
switch (builtin)
{
case BuiltInLayer:
case BuiltInPrimitiveId:
case BuiltInViewportIndex:
case BuiltInFragStencilRefEXT:
expected_type = SPIRType::Int;
break;
default:
break;
}
if (expected_type != expr_type.basetype)
{
auto type = expr_type;
type.basetype = expected_type;
expr = bitcast_expression(type, expr_type.basetype, expr);
}
}
void CompilerGLSL::convert_non_uniform_expression(const SPIRType &type, std::string &expr)
{
if (*backend.nonuniform_qualifier == '\0')
return;
// Handle SPV_EXT_descriptor_indexing.
if (type.basetype == SPIRType::Sampler || type.basetype == SPIRType::SampledImage ||
type.basetype == SPIRType::Image)
{
// The image/sampler ID must be declared as non-uniform.
// However, it is not legal GLSL to have
// nonuniformEXT(samplers[index]), so we must move the nonuniform qualifier
// to the array indexing, like
// samplers[nonuniformEXT(index)].
// While the access chain will generally be nonuniformEXT, it's not necessarily so,
// so we might have to fixup the OpLoad-ed expression late.
auto start_array_index = expr.find_first_of('[');
auto end_array_index = expr.find_last_of(']');
// Doesn't really make sense to declare a non-arrayed image with nonuniformEXT, but there's
// nothing we can do here to express that.
if (start_array_index == string::npos || end_array_index == string::npos || end_array_index < start_array_index)
return;
start_array_index++;
expr = join(expr.substr(0, start_array_index), backend.nonuniform_qualifier, "(",
expr.substr(start_array_index, end_array_index - start_array_index), ")",
expr.substr(end_array_index, string::npos));
}
}
void CompilerGLSL::emit_block_hints(const SPIRBlock &)
{
}
void CompilerGLSL::preserve_alias_on_reset(uint32_t id)
{
preserved_aliases[id] = get_name(id);
}
void CompilerGLSL::reset_name_caches()
{
for (auto &preserved : preserved_aliases)
set_name(preserved.first, preserved.second);
preserved_aliases.clear();
resource_names.clear();
block_input_names.clear();
block_output_names.clear();
block_ubo_names.clear();
block_ssbo_names.clear();
block_names.clear();
function_overloads.clear();
}
void CompilerGLSL::fixup_type_alias()
{
// Due to how some backends work, the "master" type of type_alias must be a block-like type if it exists.
// FIXME: Multiple alias types which are both block-like will be awkward, for now, it's best to just drop the type
// alias if the slave type is a block type.
ir.for_each_typed_id<SPIRType>([&](uint32_t self, SPIRType &type) {
if (type.type_alias && type_is_block_like(type))
{
// Become the master.
ir.for_each_typed_id<SPIRType>([&](uint32_t other_id, SPIRType &other_type) {
if (other_id == type.self)
return;
if (other_type.type_alias == type.type_alias)
other_type.type_alias = type.self;
});
this->get<SPIRType>(type.type_alias).type_alias = self;
type.type_alias = 0;
}
});
ir.for_each_typed_id<SPIRType>([&](uint32_t, SPIRType &type) {
if (type.type_alias && type_is_block_like(type))
{
// This is not allowed, drop the type_alias.
type.type_alias = 0;
}
});
}
void CompilerGLSL::reorder_type_alias()
{
// Reorder declaration of types so that the master of the type alias is always emitted first.
// We need this in case a type B depends on type A (A must come before in the vector), but A is an alias of a type Abuffer, which
// means declaration of A doesn't happen (yet), and order would be B, ABuffer and not ABuffer, B. Fix this up here.
auto &type_ids = ir.ids_for_type[TypeType];
for (auto alias_itr = begin(type_ids); alias_itr != end(type_ids); ++alias_itr)
{
auto &type = get<SPIRType>(*alias_itr);
if (type.type_alias != 0 && !has_extended_decoration(type.type_alias, SPIRVCrossDecorationPacked))
{
// We will skip declaring this type, so make sure the type_alias type comes before.
auto master_itr = find(begin(type_ids), end(type_ids), type.type_alias);
assert(master_itr != end(type_ids));
if (alias_itr < master_itr)
{
// Must also swap the type order for the constant-type joined array.
auto &joined_types = ir.ids_for_constant_or_type;
auto alt_alias_itr = find(begin(joined_types), end(joined_types), *alias_itr);
auto alt_master_itr = find(begin(joined_types), end(joined_types), *master_itr);
assert(alt_alias_itr != end(joined_types));
assert(alt_master_itr != end(joined_types));
swap(*alias_itr, *master_itr);
swap(*alt_alias_itr, *alt_master_itr);
}
}
}
}
void CompilerGLSL::emit_line_directive(uint32_t file_id, uint32_t line_literal)
{
// If we are redirecting statements, ignore the line directive.
// Common case here is continue blocks.
if (redirect_statement)
return;
if (options.emit_line_directives)
{
require_extension_internal("GL_GOOGLE_cpp_style_line_directive");
statement_no_indent("#line ", line_literal, " \"", get<SPIRString>(file_id).str, "\"");
}
}
void CompilerGLSL::propagate_nonuniform_qualifier(uint32_t id)
{
// SPIR-V might only tag the very last ID with NonUniformEXT, but for codegen,
// we need to know NonUniformEXT a little earlier, when the resource is actually loaded.
// Back-propagate the qualifier based on the expression dependency chain.
if (!has_decoration(id, DecorationNonUniformEXT))
{
set_decoration(id, DecorationNonUniformEXT);
force_recompile();
}
auto *e = maybe_get<SPIRExpression>(id);
auto *combined = maybe_get<SPIRCombinedImageSampler>(id);
auto *chain = maybe_get<SPIRAccessChain>(id);
if (e)
{
for (auto &expr : e->expression_dependencies)
propagate_nonuniform_qualifier(expr);
for (auto &expr : e->implied_read_expressions)
propagate_nonuniform_qualifier(expr);
}
else if (combined)
{
propagate_nonuniform_qualifier(combined->image);
propagate_nonuniform_qualifier(combined->sampler);
}
else if (chain)
{
for (auto &expr : chain->implied_read_expressions)
propagate_nonuniform_qualifier(expr);
}
}