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[a64] Implement `OPCODE_PACK`(FLOAT16) 

Fails the unit tests due to subtle rounding errors
This commit is contained in:
Wunkolo 2024-05-04 12:31:56 -07:00
parent e62f3f31d4
commit 3b2612bfc0
1 changed files with 51 additions and 2 deletions
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53
src/xenia/cpu/backend/a64/a64_seq_vector.cc
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@ -1124,8 +1124,57 @@ struct PACK : Sequence<PACK, I<OPCODE_PACK, V128Op, V128Op, V128Op>> {
e.LDR(Q0, X0);
e.TBL(i.dest.reg().B16(), List{i.dest.reg().B16()}, Q0.B16());
}
static void EmitFLOAT16_2(A64Emitter& e, const EmitArgType& i) {}
static void EmitFLOAT16_4(A64Emitter& e, const EmitArgType& i) {}
static uint8x16_t EmulateFLOAT16_2(void*, std::byte src1[16]) {
alignas(16) float a[4];
alignas(16) uint16_t b[8];
vst1q_u8(a, vld1q_u8(src1));
std::memset(b, 0, sizeof(b));
for (int i = 0; i < 2; i++) {
b[7 - i] = half_float::detail::float2half<std::round_toward_zero>(a[i]);
}
return vld1q_u8(b);
}
static void EmitFLOAT16_2(A64Emitter& e, const EmitArgType& i) {
assert_true(i.src2.value->IsConstantZero());
// http://blogs.msdn.com/b/chuckw/archive/2012/09/11/directxmath-f16c-and-fma.aspx
// dest = [(src1.x | src1.y), 0, 0, 0]
if (i.src1.is_constant) {
e.ADD(e.GetNativeParam(0), XSP, e.StashConstantV(0, i.src1.constant()));
} else {
e.ADD(e.GetNativeParam(0), XSP, e.StashV(0, i.src1));
}
e.CallNativeSafe(reinterpret_cast<void*>(EmulateFLOAT16_2));
e.MOV(i.dest.reg().B16(), Q0.B16());
}
static uint8x16_t EmulateFLOAT16_4(void*, std::byte src1[16]) {
alignas(16) float a[4];
alignas(16) uint16_t b[8];
vst1q_u8(a, vld1q_u8(src1));
std::memset(b, 0, sizeof(b));
for (int i = 0; i < 4; i++) {
b[7 - (i ^ 2)] =
half_float::detail::float2half<std::round_toward_zero>(a[i]);
}
return vld1q_u8(b);
}
static void EmitFLOAT16_4(A64Emitter& e, const EmitArgType& i) {
assert_true(i.src2.value->IsConstantZero());
// http://blogs.msdn.com/b/chuckw/archive/2012/09/11/directxmath-f16c-and-fma.aspx
// dest = [(src1.z | src1.w), (src1.x | src1.y), 0, 0]
if (i.src1.is_constant) {
e.ADD(e.GetNativeParam(0), XSP, e.StashConstantV(0, i.src1.constant()));
} else {
e.ADD(e.GetNativeParam(0), XSP, e.StashV(0, i.src1));
}
e.CallNativeSafe(reinterpret_cast<void*>(EmulateFLOAT16_4));
e.MOV(i.dest.reg().B16(), Q0.B16());
}
static void EmitSHORT_2(A64Emitter& e, const EmitArgType& i) {}
static void EmitSHORT_4(A64Emitter& e, const EmitArgType& i) {}
static void EmitUINT_2101010(A64Emitter& e, const EmitArgType& i) {}