SPU LLVM: Improve approx FCGT (#8728)

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Eladash 2020-08-14 21:33:35 +03:00 committed by GitHub
parent 01d3585bf3
commit 995cb8125e
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@ -7552,63 +7552,53 @@ public:
return;
}
const auto a = get_vr<f32[4]>(op.ra);
const auto b = get_vr<f32[4]>(op.rb);
const auto [a, b] = get_vrs<f32[4]>(op.ra, op.rb);
const value_t<f32[4]> ab[2]{a, b};
if (auto [ok, data] = get_const_vector(b.value, m_pos, 5000); ok)
std::bitset<2> safe_int_compare(0);
std::bitset<2> safe_nonzero_compare(0);
for (u32 i = 0; i < 2; i++)
{
bool safe_int_compare = true;
for (u32 i = 0; i < 4; i++)
if (auto [ok, data] = get_const_vector(ab[i].value, m_pos, 5000); ok)
{
const u32 exponent = data._u32[i] & 0x7f800000u;
safe_int_compare.set(i);
safe_nonzero_compare.set(i);
if (data._u32[i] >= 0x7f7fffffu || !exponent)
for (u32 j = 0; j < 4; j++)
{
// Postive or negative zero, Denormal (treated as zero), Negative constant, or Normalized number with exponent +127
// Cannot used signed integer compare safely
// Note: Technically this optimization is accurate for any positive value, but due to the fact that
// we don't produce "extended range" values the same way as real hardware, it's not safe to apply
// this optimization for values outside of the range of x86 floating point hardware.
safe_int_compare = false;
}
}
const u32 value = data._u32[j];
const u8 exponent = static_cast<u8>(value >> 23);
if (safe_int_compare)
{
set_vr(op.rt, sext<s32[4]>(bitcast<s32[4]>(a) > bitcast<s32[4]>(b)));
return;
if (value >= 0x7f7fffffu || !exponent)
{
// Postive or negative zero, Denormal (treated as zero), Negative constant, or Normalized number with exponent +127
// Cannot used signed integer compare safely
// Note: Technically this optimization is accurate for any positive value, but due to the fact that
// we don't produce "extended range" values the same way as real hardware, it's not safe to apply
// this optimization for values outside of the range of x86 floating point hardware.
safe_int_compare.reset(i);
if (!exponent) safe_nonzero_compare.reset(i);
}
}
}
}
if (auto [ok, data] = get_const_vector(a.value, m_pos, 5000); ok)
if (safe_int_compare.any())
{
bool safe_int_compare = true;
for (u32 i = 0; i < 4; i++)
{
const u32 exponent = data._u32[i] & 0x7f800000u;
if (data._u32[i] >= 0x7f7fffffu || !exponent)
{
// See above
safe_int_compare = false;
break;
}
}
if (safe_int_compare)
{
set_vr(op.rt, sext<s32[4]>(bitcast<s32[4]>(a) > bitcast<s32[4]>(b)));
return;
}
set_vr(op.rt, sext<s32[4]>(bitcast<s32[4]>(a) > bitcast<s32[4]>(b)));
return;
}
if (g_cfg.core.spu_approx_xfloat)
{
const auto ca = eval(clamp_positive_smax(a));
const auto cb = eval(clamp_negative_smax(b));
set_vr(op.rt, sext<s32[4]>(fcmp_ord(ca > cb)));
const auto ai = eval(bitcast<s32[4]>(a));
const auto bi = eval(bitcast<s32[4]>(b));
if (!safe_nonzero_compare.any())
set_vr(op.rt, sext<s32[4]>(fcmp_uno(a != b) & select((ai & bi) >= 0, ai > bi, ai < bi)));
else
set_vr(op.rt, sext<s32[4]>(select((ai & bi) >= 0, ai > bi, ai < bi)));
}
else
{