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[X86] IsElementEquivalent - add handling for ISD::BITCASTS from smaller vector elements #139741

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Merged
merged 9 commits into from
May 23, 2025
Merged

[X86] IsElementEquivalent - add handling for ISD::BITCASTS from smaller vector elements #139741

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[X86] IsElementEquivalent - add handling for ISD::BITCASTS from small…
RKSimon May 13, 2025
b04822d
Merge branch 'main' into x86-equivalent-bitcasts
RKSimon May 18, 2025
495673a
Merge branch 'main' into x86-equivalent-bitcasts
RKSimon May 19, 2025
48aca61
[X86] IsElementEquivalent - early-out for non-equivalent bitcasted su…
RKSimon May 19, 2025
c592ac2
Merge branch 'main' into x86-equivalent-bitcasts
RKSimon May 22, 2025
5f7c9a6
Merge branch 'upstream' into x86-equivalent-bitcasts
RKSimon May 22, 2025
fd1a5c9
Merge branch 'upstream' into x86-equivalent-bitcasts
RKSimon May 22, 2025
d02bbbc
combine-concatvectors.ll - regenerate checks
RKSimon May 22, 2025
7762631
Merge branch 'main' into x86-equivalent-bitcasts
RKSimon May 23, 2025
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22 changes: 16 additions & 6 deletions llvm/lib/Target/X86/X86ISelLowering.cpp
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Expand Up @@ -9987,19 +9987,29 @@ static bool IsElementEquivalent(int MaskSize, SDValue Op, SDValue ExpectedOp,
MaskSize == (int)ExpectedOp.getNumOperands())
return Op.getOperand(Idx) == ExpectedOp.getOperand(ExpectedIdx);
break;
case ISD::BITCAST:
if (Op == ExpectedOp && (int)VT.getVectorNumElements() == MaskSize) {
SDValue Src = peekThroughBitcasts(Op);
EVT SrcVT = Src.getValueType();
if (SrcVT.isVector() &&
(SrcVT.getScalarSizeInBits() % VT.getScalarSizeInBits()) == 0) {
case ISD::BITCAST: {
SDValue Src = peekThroughBitcasts(Op);
EVT SrcVT = Src.getValueType();
if (Op == ExpectedOp && SrcVT.isVector() &&
(int)VT.getVectorNumElements() == MaskSize) {
if ((SrcVT.getScalarSizeInBits() % VT.getScalarSizeInBits()) == 0) {
unsigned Scale = SrcVT.getScalarSizeInBits() / VT.getScalarSizeInBits();
return (Idx % Scale) == (ExpectedIdx % Scale) &&
IsElementEquivalent(SrcVT.getVectorNumElements(), Src, Src,
Idx / Scale, ExpectedIdx / Scale);
}
if ((VT.getScalarSizeInBits() % SrcVT.getScalarSizeInBits()) == 0) {
unsigned Scale = VT.getScalarSizeInBits() / SrcVT.getScalarSizeInBits();
for (unsigned I = 0; I != Scale; ++I)
if (!IsElementEquivalent(SrcVT.getVectorNumElements(), Src, Src,
(Idx * Scale) + I,
(ExpectedIdx * Scale) + I))
return false;
return true;
}
}
break;
}
case ISD::VECTOR_SHUFFLE: {
auto *SVN = cast<ShuffleVectorSDNode>(Op);
return Op == ExpectedOp && (int)VT.getVectorNumElements() == MaskSize &&
Expand Down
6 changes: 3 additions & 3 deletions llvm/test/CodeGen/X86/expand-vp-cast-intrinsics.ll
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Expand Up @@ -532,10 +532,10 @@ define <2 x half> @vfptrunc_v2f16_v2f64(<2 x double> %a, <2 x i1> %m, i32 zeroex
; AVX512-NEXT: vmovdqa %xmm0, (%rsp) # 16-byte Spill
; AVX512-NEXT: callq __truncdfhf2@PLT
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vmovdqa (%rsp), %xmm1 # 16-byte Reload
; AVX512-NEXT: vpunpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
; AVX512-NEXT: vpblendd $13, (%rsp), %xmm0, %xmm1 # 16-byte Folded Reload
; AVX512-NEXT: # xmm1 = mem[0],xmm0[1],mem[2,3]
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
; AVX512-NEXT: vpblendd {{.*#+}} xmm0 = xmm1[0,1],xmm0[2,3]
; AVX512-NEXT: addq $40, %rsp
; AVX512-NEXT: .cfi_def_cfa_offset 8
; AVX512-NEXT: retq
Expand Down
15 changes: 7 additions & 8 deletions llvm/test/CodeGen/X86/horizontal-sum.ll
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Expand Up @@ -179,8 +179,8 @@ define <8 x float> @pair_sum_v8f32_v4f32(<4 x float> %0, <4 x float> %1, <4 x fl
; SSSE3-SLOW-NEXT: movlhps {{.*#+}} xmm0 = xmm0[0],xmm2[0]
; SSSE3-SLOW-NEXT: haddps %xmm7, %xmm6
; SSSE3-SLOW-NEXT: haddps %xmm6, %xmm6
; SSSE3-SLOW-NEXT: shufps {{.*#+}} xmm2 = xmm2[2,3],xmm6[0,1]
; SSSE3-SLOW-NEXT: movaps %xmm2, %xmm1
; SSSE3-SLOW-NEXT: movhlps {{.*#+}} xmm6 = xmm2[1],xmm6[1]
; SSSE3-SLOW-NEXT: movaps %xmm6, %xmm1
; SSSE3-SLOW-NEXT: retq
;
; SSSE3-FAST-LABEL: pair_sum_v8f32_v4f32:
Expand Down Expand Up @@ -345,8 +345,7 @@ define <8 x i32> @pair_sum_v8i32_v4i32(<4 x i32> %0, <4 x i32> %1, <4 x i32> %2,
; SSSE3-SLOW-NEXT: punpcklqdq {{.*#+}} xmm0 = xmm0[0],xmm1[0]
; SSSE3-SLOW-NEXT: phaddd %xmm7, %xmm6
; SSSE3-SLOW-NEXT: phaddd %xmm6, %xmm6
; SSSE3-SLOW-NEXT: palignr {{.*#+}} xmm6 = xmm1[8,9,10,11,12,13,14,15],xmm6[0,1,2,3,4,5,6,7]
; SSSE3-SLOW-NEXT: movdqa %xmm6, %xmm1
; SSSE3-SLOW-NEXT: punpckhqdq {{.*#+}} xmm1 = xmm1[1],xmm6[1]
; SSSE3-SLOW-NEXT: retq
;
; SSSE3-FAST-LABEL: pair_sum_v8i32_v4i32:
Expand Down Expand Up @@ -374,7 +373,7 @@ define <8 x i32> @pair_sum_v8i32_v4i32(<4 x i32> %0, <4 x i32> %1, <4 x i32> %2,
; AVX1-SLOW-NEXT: vphaddd %xmm5, %xmm5, %xmm4
; AVX1-SLOW-NEXT: vphaddd %xmm3, %xmm2, %xmm2
; AVX1-SLOW-NEXT: vpshufd {{.*#+}} xmm3 = xmm2[0,2,2,3]
; AVX1-SLOW-NEXT: vpunpcklqdq {{.*#+}} xmm3 = xmm3[0],xmm1[0]
; AVX1-SLOW-NEXT: vpblendw {{.*#+}} xmm3 = xmm3[0,1,2,3],xmm1[4,5,6,7]
; AVX1-SLOW-NEXT: vpshufd {{.*#+}} xmm5 = xmm4[0,0,0,0]
; AVX1-SLOW-NEXT: vpblendw {{.*#+}} xmm3 = xmm3[0,1,2,3,4,5],xmm5[6,7]
; AVX1-SLOW-NEXT: vshufps {{.*#+}} xmm1 = xmm2[1,3],xmm1[1,3]
Expand All @@ -397,7 +396,7 @@ define <8 x i32> @pair_sum_v8i32_v4i32(<4 x i32> %0, <4 x i32> %1, <4 x i32> %2,
; AVX1-FAST-NEXT: vphaddd %xmm5, %xmm5, %xmm4
; AVX1-FAST-NEXT: vphaddd %xmm3, %xmm2, %xmm2
; AVX1-FAST-NEXT: vpshufd {{.*#+}} xmm3 = xmm2[0,2,2,3]
; AVX1-FAST-NEXT: vpunpcklqdq {{.*#+}} xmm3 = xmm3[0],xmm1[0]
; AVX1-FAST-NEXT: vpblendw {{.*#+}} xmm3 = xmm3[0,1,2,3],xmm1[4,5,6,7]
; AVX1-FAST-NEXT: vpshufd {{.*#+}} xmm5 = xmm4[0,0,0,0]
; AVX1-FAST-NEXT: vpblendw {{.*#+}} xmm3 = xmm3[0,1,2,3,4,5],xmm5[6,7]
; AVX1-FAST-NEXT: vshufps {{.*#+}} xmm1 = xmm2[1,3],xmm1[1,3]
Expand All @@ -422,7 +421,7 @@ define <8 x i32> @pair_sum_v8i32_v4i32(<4 x i32> %0, <4 x i32> %1, <4 x i32> %2,
; AVX2-SLOW-NEXT: vphaddd %xmm5, %xmm5, %xmm4
; AVX2-SLOW-NEXT: vphaddd %xmm3, %xmm2, %xmm2
; AVX2-SLOW-NEXT: vpshufd {{.*#+}} xmm3 = xmm2[0,2,2,3]
; AVX2-SLOW-NEXT: vpunpcklqdq {{.*#+}} xmm3 = xmm3[0],xmm1[0]
; AVX2-SLOW-NEXT: vpblendd {{.*#+}} xmm3 = xmm3[0,1],xmm1[2,3]
; AVX2-SLOW-NEXT: vpbroadcastd %xmm4, %xmm5
; AVX2-SLOW-NEXT: vpblendd {{.*#+}} xmm3 = xmm3[0,1,2],xmm5[3]
; AVX2-SLOW-NEXT: vshufps {{.*#+}} xmm1 = xmm2[1,3],xmm1[1,1]
Expand All @@ -445,7 +444,7 @@ define <8 x i32> @pair_sum_v8i32_v4i32(<4 x i32> %0, <4 x i32> %1, <4 x i32> %2,
; AVX2-FAST-NEXT: vphaddd %xmm5, %xmm5, %xmm4
; AVX2-FAST-NEXT: vphaddd %xmm3, %xmm2, %xmm2
; AVX2-FAST-NEXT: vpshufd {{.*#+}} xmm3 = xmm2[0,2,2,3]
; AVX2-FAST-NEXT: vpunpcklqdq {{.*#+}} xmm3 = xmm3[0],xmm1[0]
; AVX2-FAST-NEXT: vpblendd {{.*#+}} xmm3 = xmm3[0,1],xmm1[2,3]
; AVX2-FAST-NEXT: vpbroadcastd %xmm4, %xmm5
; AVX2-FAST-NEXT: vpblendd {{.*#+}} xmm3 = xmm3[0,1,2],xmm5[3]
; AVX2-FAST-NEXT: vshufps {{.*#+}} xmm1 = xmm2[1,3],xmm1[1,1]
Expand Down
18 changes: 9 additions & 9 deletions llvm/test/CodeGen/X86/vector-half-conversions.ll
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Expand Up @@ -3138,10 +3138,10 @@ define <2 x i16> @cvt_2f64_to_2i16(<2 x double> %a0) nounwind {
; AVX512-NEXT: vmovdqa %xmm0, (%rsp) # 16-byte Spill
; AVX512-NEXT: callq __truncdfhf2@PLT
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vmovdqa (%rsp), %xmm1 # 16-byte Reload
; AVX512-NEXT: vpunpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
; AVX512-NEXT: vpblendd $13, (%rsp), %xmm0, %xmm1 # 16-byte Folded Reload
; AVX512-NEXT: # xmm1 = mem[0],xmm0[1],mem[2,3]
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
; AVX512-NEXT: vpblendd {{.*#+}} xmm0 = xmm1[0,1],xmm0[2,3]
; AVX512-NEXT: addq $40, %rsp
; AVX512-NEXT: retq
%1 = fptrunc <2 x double> %a0 to <2 x half>
Expand Down Expand Up @@ -3272,8 +3272,8 @@ define <4 x i16> @cvt_4f64_to_4i16(<4 x double> %a0) nounwind {
; AVX512-NEXT: vmovdqa %xmm0, {{[-0-9]+}}(%r{{[sb]}}p) # 16-byte Spill
; AVX512-NEXT: callq __truncdfhf2@PLT
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vmovdqa {{[-0-9]+}}(%r{{[sb]}}p), %xmm1 # 16-byte Reload
; AVX512-NEXT: vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
; AVX512-NEXT: vpblendd $3, {{[-0-9]+}}(%r{{[sb]}}p), %xmm0, %xmm0 # 16-byte Folded Reload
; AVX512-NEXT: # xmm0 = mem[0,1],xmm0[2,3]
; AVX512-NEXT: addq $72, %rsp
; AVX512-NEXT: retq
%1 = fptrunc <4 x double> %a0 to <4 x half>
Expand Down Expand Up @@ -3404,8 +3404,8 @@ define <8 x i16> @cvt_4f64_to_8i16_undef(<4 x double> %a0) nounwind {
; AVX512-NEXT: vmovdqa %xmm0, {{[-0-9]+}}(%r{{[sb]}}p) # 16-byte Spill
; AVX512-NEXT: callq __truncdfhf2@PLT
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vmovdqa {{[-0-9]+}}(%r{{[sb]}}p), %xmm1 # 16-byte Reload
; AVX512-NEXT: vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
; AVX512-NEXT: vpblendd $3, {{[-0-9]+}}(%r{{[sb]}}p), %xmm0, %xmm0 # 16-byte Folded Reload
; AVX512-NEXT: # xmm0 = mem[0,1],xmm0[2,3]
; AVX512-NEXT: addq $72, %rsp
; AVX512-NEXT: retq
%1 = fptrunc <4 x double> %a0 to <4 x half>
Expand Down Expand Up @@ -4107,8 +4107,8 @@ define void @store_cvt_4f64_to_8i16_undef(<4 x double> %a0, ptr %a1) nounwind {
; AVX512-NEXT: vmovdqa %xmm0, {{[-0-9]+}}(%r{{[sb]}}p) # 16-byte Spill
; AVX512-NEXT: callq __truncdfhf2@PLT
; AVX512-NEXT: vpbroadcastw %xmm0, %xmm0
; AVX512-NEXT: vmovdqa {{[-0-9]+}}(%r{{[sb]}}p), %xmm1 # 16-byte Reload
; AVX512-NEXT: vpunpcklqdq {{.*#+}} xmm0 = xmm1[0],xmm0[0]
; AVX512-NEXT: vpblendd $3, {{[-0-9]+}}(%r{{[sb]}}p), %xmm0, %xmm0 # 16-byte Folded Reload
; AVX512-NEXT: # xmm0 = mem[0,1],xmm0[2,3]
; AVX512-NEXT: vmovdqa %xmm0, (%rbx)
; AVX512-NEXT: addq $64, %rsp
; AVX512-NEXT: popq %rbx
Expand Down
18 changes: 6 additions & 12 deletions llvm/test/CodeGen/X86/vector-mul.ll
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Expand Up @@ -1569,25 +1569,19 @@ define <2 x i64> @mul_v2i64_neg_17_65(<2 x i64> %a0) nounwind {
}

define <2 x i64> @mul_v2i64_0_1(<2 x i64> %a0) nounwind {
; X86-SSE2-LABEL: mul_v2i64_0_1:
; X86-SSE2: # %bb.0:
; X86-SSE2-NEXT: xorpd %xmm1, %xmm1
; X86-SSE2-NEXT: movsd {{.*#+}} xmm0 = xmm1[0],xmm0[1]
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It seems movsd is better

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Are you just referring to the extra move?

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No, I mean movsd is better than unpckhpd

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I'm struggling to come up with a way DAG can handle this cleanly - these are v2i64 shuffles that the domain pass flipped later on, much later than the TwoAddr commutation fixes. Whats happened is the i686 targets are now able to see the v2i64 zero (legalised to v4i32 zero) and match as a v2i64 shuffle instead of falling back to a v2f64 bitcasted shuffle. Unless we can demonstrate that MOVSD/S isn't affected by domain crossing we don't have a good pass to fix this :(

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to be clear, all that has happened is the i686 codegen now matches the x86_64 which has always had this int/fp domain behavior

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Ok, I think 32-bit performance is not so important.

; X86-SSE2-NEXT: retl
; SSE2-LABEL: mul_v2i64_0_1:
; SSE2: # %bb.0:
; SSE2-NEXT: xorps %xmm1, %xmm1
; SSE2-NEXT: unpckhpd {{.*#+}} xmm1 = xmm1[1],xmm0[1]
; SSE2-NEXT: movaps %xmm1, %xmm0
; SSE2-NEXT: ret{{[l|q]}}
;
; SSE4-LABEL: mul_v2i64_0_1:
; SSE4: # %bb.0:
; SSE4-NEXT: xorps %xmm1, %xmm1
; SSE4-NEXT: blendps {{.*#+}} xmm0 = xmm1[0,1],xmm0[2,3]
; SSE4-NEXT: ret{{[l|q]}}
;
; X64-SSE2-LABEL: mul_v2i64_0_1:
; X64-SSE2: # %bb.0:
; X64-SSE2-NEXT: xorps %xmm1, %xmm1
; X64-SSE2-NEXT: unpckhpd {{.*#+}} xmm1 = xmm1[1],xmm0[1]
; X64-SSE2-NEXT: movaps %xmm1, %xmm0
; X64-SSE2-NEXT: retq
;
; X64-AVX-LABEL: mul_v2i64_0_1:
; X64-AVX: # %bb.0:
; X64-AVX-NEXT: vxorps %xmm1, %xmm1, %xmm1
Expand Down
34 changes: 23 additions & 11 deletions llvm/test/CodeGen/X86/zero_extend_vector_inreg_of_broadcast.ll
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Expand Up @@ -7065,17 +7065,29 @@ define void @vec512_i64_widen_to_i256_factor4_broadcast_to_v2i256_factor2(ptr %i
; AVX512DQ-NEXT: vzeroupper
; AVX512DQ-NEXT: retq
;
; AVX512BW-LABEL: vec512_i64_widen_to_i256_factor4_broadcast_to_v2i256_factor2:
; AVX512BW: # %bb.0:
; AVX512BW-NEXT: vmovdqa (%rdi), %xmm0
; AVX512BW-NEXT: vpaddb (%rsi), %xmm0, %xmm0
; AVX512BW-NEXT: vpxor %xmm1, %xmm1, %xmm1
; AVX512BW-NEXT: vpmovsxbq {{.*#+}} zmm2 = [0,9,2,11,0,13,2,15]
; AVX512BW-NEXT: vpermi2q %zmm1, %zmm0, %zmm2
; AVX512BW-NEXT: vpaddb (%rdx), %zmm2, %zmm0
; AVX512BW-NEXT: vmovdqa64 %zmm0, (%rcx)
; AVX512BW-NEXT: vzeroupper
; AVX512BW-NEXT: retq
; AVX512BW-SLOW-LABEL: vec512_i64_widen_to_i256_factor4_broadcast_to_v2i256_factor2:
; AVX512BW-SLOW: # %bb.0:
; AVX512BW-SLOW-NEXT: vmovdqa (%rdi), %xmm0
; AVX512BW-SLOW-NEXT: vpaddb (%rsi), %xmm0, %xmm0
; AVX512BW-SLOW-NEXT: vinserti64x4 $1, %ymm0, %zmm0, %zmm0
; AVX512BW-SLOW-NEXT: vpxor %xmm1, %xmm1, %xmm1
; AVX512BW-SLOW-NEXT: vpunpcklqdq {{.*#+}} zmm0 = zmm0[0],zmm1[0],zmm0[2],zmm1[2],zmm0[4],zmm1[4],zmm0[6],zmm1[6]
; AVX512BW-SLOW-NEXT: vpaddb (%rdx), %zmm0, %zmm0
; AVX512BW-SLOW-NEXT: vmovdqa64 %zmm0, (%rcx)
; AVX512BW-SLOW-NEXT: vzeroupper
; AVX512BW-SLOW-NEXT: retq
;
; AVX512BW-FAST-LABEL: vec512_i64_widen_to_i256_factor4_broadcast_to_v2i256_factor2:
; AVX512BW-FAST: # %bb.0:
; AVX512BW-FAST-NEXT: vmovdqa (%rdi), %xmm0
; AVX512BW-FAST-NEXT: vpaddb (%rsi), %xmm0, %xmm0
; AVX512BW-FAST-NEXT: vpxor %xmm1, %xmm1, %xmm1
; AVX512BW-FAST-NEXT: vpmovsxbq {{.*#+}} zmm2 = [0,9,2,11,0,13,2,15]
; AVX512BW-FAST-NEXT: vpermi2q %zmm1, %zmm0, %zmm2
; AVX512BW-FAST-NEXT: vpaddb (%rdx), %zmm2, %zmm0
; AVX512BW-FAST-NEXT: vmovdqa64 %zmm0, (%rcx)
; AVX512BW-FAST-NEXT: vzeroupper
; AVX512BW-FAST-NEXT: retq
%in.vec.base = load <64 x i8>, ptr %in.vec.base.ptr, align 64
%in.vec.bias = load <64 x i8>, ptr %in.vec.bias.ptr, align 64
%in.vec = add <64 x i8> %in.vec.base, %in.vec.bias
Expand Down
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