common/bit_util: Replace CLZ/CTZ operations with standardized ones

Makes for less code that we need to maintain.
This commit is contained in:
Lioncash 2021-01-15 02:02:57 -05:00
parent c8bf0caca0
commit 8620de6b20
10 changed files with 17 additions and 113 deletions

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@ -21,82 +21,6 @@ template <typename T>
return sizeof(T) * CHAR_BIT; return sizeof(T) * CHAR_BIT;
} }
#ifdef _MSC_VER
[[nodiscard]] inline u32 CountLeadingZeroes32(u32 value) {
unsigned long leading_zero = 0;
if (_BitScanReverse(&leading_zero, value) != 0) {
return 31 - leading_zero;
}
return 32;
}
[[nodiscard]] inline u32 CountLeadingZeroes64(u64 value) {
unsigned long leading_zero = 0;
if (_BitScanReverse64(&leading_zero, value) != 0) {
return 63 - leading_zero;
}
return 64;
}
#else
[[nodiscard]] inline u32 CountLeadingZeroes32(u32 value) {
if (value == 0) {
return 32;
}
return static_cast<u32>(__builtin_clz(value));
}
[[nodiscard]] inline u32 CountLeadingZeroes64(u64 value) {
if (value == 0) {
return 64;
}
return static_cast<u32>(__builtin_clzll(value));
}
#endif
#ifdef _MSC_VER
[[nodiscard]] inline u32 CountTrailingZeroes32(u32 value) {
unsigned long trailing_zero = 0;
if (_BitScanForward(&trailing_zero, value) != 0) {
return trailing_zero;
}
return 32;
}
[[nodiscard]] inline u32 CountTrailingZeroes64(u64 value) {
unsigned long trailing_zero = 0;
if (_BitScanForward64(&trailing_zero, value) != 0) {
return trailing_zero;
}
return 64;
}
#else
[[nodiscard]] inline u32 CountTrailingZeroes32(u32 value) {
if (value == 0) {
return 32;
}
return static_cast<u32>(__builtin_ctz(value));
}
[[nodiscard]] inline u32 CountTrailingZeroes64(u64 value) {
if (value == 0) {
return 64;
}
return static_cast<u32>(__builtin_ctzll(value));
}
#endif
#ifdef _MSC_VER #ifdef _MSC_VER
[[nodiscard]] inline u32 MostSignificantBit32(const u32 value) { [[nodiscard]] inline u32 MostSignificantBit32(const u32 value) {

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@ -8,11 +8,11 @@
#pragma once #pragma once
#include <array> #include <array>
#include <bit>
#include <concepts> #include <concepts>
#include "common/assert.h" #include "common/assert.h"
#include "common/bit_set.h" #include "common/bit_set.h"
#include "common/bit_util.h"
#include "common/common_types.h" #include "common/common_types.h"
#include "common/concepts.h" #include "common/concepts.h"
@ -268,7 +268,7 @@ private:
} }
constexpr s32 GetNextCore(u64& affinity) { constexpr s32 GetNextCore(u64& affinity) {
const s32 core = Common::CountTrailingZeroes64(affinity); const s32 core = std::countr_zero(affinity);
ClearAffinityBit(affinity, core); ClearAffinityBit(affinity, core);
return core; return core;
} }

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@ -5,6 +5,8 @@
// This file references various implementation details from Atmosphere, an open-source firmware for // This file references various implementation details from Atmosphere, an open-source firmware for
// the Nintendo Switch. Copyright 2018-2020 Atmosphere-NX. // the Nintendo Switch. Copyright 2018-2020 Atmosphere-NX.
#include <bit>
#include "common/assert.h" #include "common/assert.h"
#include "common/bit_util.h" #include "common/bit_util.h"
#include "common/fiber.h" #include "common/fiber.h"
@ -31,12 +33,12 @@ static void IncrementScheduledCount(Kernel::Thread* thread) {
void KScheduler::RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule, void KScheduler::RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule,
Core::EmuThreadHandle global_thread) { Core::EmuThreadHandle global_thread) {
u32 current_core = global_thread.host_handle; const u32 current_core = global_thread.host_handle;
bool must_context_switch = global_thread.guest_handle != InvalidHandle && bool must_context_switch = global_thread.guest_handle != InvalidHandle &&
(current_core < Core::Hardware::NUM_CPU_CORES); (current_core < Core::Hardware::NUM_CPU_CORES);
while (cores_pending_reschedule != 0) { while (cores_pending_reschedule != 0) {
u32 core = Common::CountTrailingZeroes64(cores_pending_reschedule); const auto core = static_cast<u32>(std::countr_zero(cores_pending_reschedule));
ASSERT(core < Core::Hardware::NUM_CPU_CORES); ASSERT(core < Core::Hardware::NUM_CPU_CORES);
if (!must_context_switch || core != current_core) { if (!must_context_switch || core != current_core) {
auto& phys_core = kernel.PhysicalCore(core); auto& phys_core = kernel.PhysicalCore(core);
@ -109,7 +111,7 @@ u64 KScheduler::UpdateHighestPriorityThreadsImpl(KernelCore& kernel) {
// Idle cores are bad. We're going to try to migrate threads to each idle core in turn. // Idle cores are bad. We're going to try to migrate threads to each idle core in turn.
while (idle_cores != 0) { while (idle_cores != 0) {
u32 core_id = Common::CountTrailingZeroes64(idle_cores); const auto core_id = static_cast<u32>(std::countr_zero(idle_cores));
if (Thread* suggested = priority_queue.GetSuggestedFront(core_id); suggested != nullptr) { if (Thread* suggested = priority_queue.GetSuggestedFront(core_id); suggested != nullptr) {
s32 migration_candidates[Core::Hardware::NUM_CPU_CORES]; s32 migration_candidates[Core::Hardware::NUM_CPU_CORES];
size_t num_candidates = 0; size_t num_candidates = 0;

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@ -8,11 +8,11 @@
#pragma once #pragma once
#include <array> #include <array>
#include <bit>
#include <vector> #include <vector>
#include "common/alignment.h" #include "common/alignment.h"
#include "common/assert.h" #include "common/assert.h"
#include "common/bit_util.h"
#include "common/common_funcs.h" #include "common/common_funcs.h"
#include "common/common_types.h" #include "common/common_types.h"
#include "core/hle/kernel/memory/memory_types.h" #include "core/hle/kernel/memory/memory_types.h"
@ -105,7 +105,7 @@ private:
ASSERT(depth == 0); ASSERT(depth == 0);
return -1; return -1;
} }
offset = offset * 64 + Common::CountTrailingZeroes64(v); offset = offset * 64 + static_cast<u32>(std::countr_zero(v));
++depth; ++depth;
} while (depth < static_cast<s32>(used_depths)); } while (depth < static_cast<s32>(used_depths));

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@ -2,6 +2,8 @@
// Licensed under GPLv2 or any later version // Licensed under GPLv2 or any later version
// Refer to the license.txt file included. // Refer to the license.txt file included.
#include <bit>
#include "common/bit_util.h" #include "common/bit_util.h"
#include "common/logging/log.h" #include "common/logging/log.h"
#include "core/hle/kernel/errors.h" #include "core/hle/kernel/errors.h"
@ -60,7 +62,7 @@ constexpr CapabilityType GetCapabilityType(u32 value) {
u32 GetFlagBitOffset(CapabilityType type) { u32 GetFlagBitOffset(CapabilityType type) {
const auto value = static_cast<u32>(type); const auto value = static_cast<u32>(type);
return static_cast<u32>(Common::BitSize<u32>() - Common::CountLeadingZeroes32(value)); return static_cast<u32>(Common::BitSize<u32>() - static_cast<u32>(std::countl_zero(value)));
} }
} // Anonymous namespace } // Anonymous namespace

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@ -1,6 +1,5 @@
add_executable(tests add_executable(tests
common/bit_field.cpp common/bit_field.cpp
common/bit_utils.cpp
common/fibers.cpp common/fibers.cpp
common/param_package.cpp common/param_package.cpp
common/ring_buffer.cpp common/ring_buffer.cpp

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@ -1,23 +0,0 @@
// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <catch2/catch.hpp>
#include <math.h>
#include "common/bit_util.h"
namespace Common {
TEST_CASE("BitUtils::CountTrailingZeroes", "[common]") {
REQUIRE(Common::CountTrailingZeroes32(0) == 32);
REQUIRE(Common::CountTrailingZeroes64(0) == 64);
REQUIRE(Common::CountTrailingZeroes32(9) == 0);
REQUIRE(Common::CountTrailingZeroes32(8) == 3);
REQUIRE(Common::CountTrailingZeroes32(0x801000) == 12);
REQUIRE(Common::CountTrailingZeroes64(9) == 0);
REQUIRE(Common::CountTrailingZeroes64(8) == 3);
REQUIRE(Common::CountTrailingZeroes64(0x801000) == 12);
REQUIRE(Common::CountTrailingZeroes64(0x801000000000UL) == 36);
}
} // namespace Common

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@ -18,10 +18,10 @@
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// //
#include <bit>
#include "command_classes/host1x.h" #include "command_classes/host1x.h"
#include "command_classes/nvdec.h" #include "command_classes/nvdec.h"
#include "command_classes/vic.h" #include "command_classes/vic.h"
#include "common/bit_util.h"
#include "video_core/cdma_pusher.h" #include "video_core/cdma_pusher.h"
#include "video_core/command_classes/nvdec_common.h" #include "video_core/command_classes/nvdec_common.h"
#include "video_core/engines/maxwell_3d.h" #include "video_core/engines/maxwell_3d.h"
@ -56,7 +56,7 @@ void CDmaPusher::Step() {
for (const u32 value : values) { for (const u32 value : values) {
if (mask != 0) { if (mask != 0) {
const u32 lbs = Common::CountTrailingZeroes32(mask); const auto lbs = static_cast<u32>(std::countr_zero(mask));
mask &= ~(1U << lbs); mask &= ~(1U << lbs);
ExecuteCommand(static_cast<u32>(offset + lbs), value); ExecuteCommand(static_cast<u32>(offset + lbs), value);
continue; continue;

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@ -126,7 +126,7 @@ private:
s32 count{}; s32 count{};
s32 offset{}; s32 offset{};
s32 mask{}; u32 mask{};
bool incrementing{}; bool incrementing{};
// Queue of command lists to be processed // Queue of command lists to be processed

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@ -19,7 +19,7 @@
// //
#include <array> #include <array>
#include "common/bit_util.h" #include <bit>
#include "video_core/command_classes/codecs/h264.h" #include "video_core/command_classes/codecs/h264.h"
#include "video_core/gpu.h" #include "video_core/gpu.h"
#include "video_core/memory_manager.h" #include "video_core/memory_manager.h"
@ -266,7 +266,7 @@ void H264BitWriter::WriteExpGolombCodedInt(s32 value) {
} }
void H264BitWriter::WriteExpGolombCodedUInt(u32 value) { void H264BitWriter::WriteExpGolombCodedUInt(u32 value) {
const s32 size = 32 - Common::CountLeadingZeroes32(static_cast<s32>(value + 1)); const s32 size = 32 - std::countl_zero(value + 1);
WriteBits(1, size); WriteBits(1, size);
value -= (1U << (size - 1)) - 1; value -= (1U << (size - 1)) - 1;