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[X86][EVEX512] Do not allow 512-bit memcpy without EVEX512 #70420

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Merged
merged 2 commits into from
Oct 27, 2023
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[X86][EVEX512] Do not allow 512-bit memcpy without EVEX512 #70420

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[X86][EVEX512] Do not allow 512-bit memcpy without EVEX512
phoebewang Oct 27, 2023
902b356
Address review comments
phoebewang Oct 27, 2023
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4 changes: 2 additions & 2 deletions llvm/lib/Target/X86/X86ISelLoweringCall.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -281,7 +281,7 @@ EVT X86TargetLowering::getOptimalMemOpType(
if (Op.size() >= 16 &&
(!Subtarget.isUnalignedMem16Slow() || Op.isAligned(Align(16)))) {
// FIXME: Check if unaligned 64-byte accesses are slow.
if (Op.size() >= 64 && Subtarget.hasAVX512() &&
if (Op.size() >= 64 && Subtarget.hasAVX512() && Subtarget.hasEVEX512() &&
(Subtarget.getPreferVectorWidth() >= 512)) {
return Subtarget.hasBWI() ? MVT::v64i8 : MVT::v16i32;
}
Expand Down Expand Up @@ -395,7 +395,7 @@ bool X86TargetLowering::allowsMemoryAccess(LLVMContext &Context,
return true;
return false;
case 512:
if (Subtarget.hasAVX512())
if (Subtarget.hasAVX512() && Subtarget.hasEVEX512())
return true;
return false;
default:
Expand Down
5 changes: 3 additions & 2 deletions llvm/lib/Target/X86/X86TargetTransformInfo.cpp
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Expand Up @@ -180,7 +180,7 @@ X86TTIImpl::getRegisterBitWidth(TargetTransformInfo::RegisterKind K) const {
case TargetTransformInfo::RGK_Scalar:
return TypeSize::getFixed(ST->is64Bit() ? 64 : 32);
case TargetTransformInfo::RGK_FixedWidthVector:
if (ST->hasAVX512() && PreferVectorWidth >= 512)
if (ST->hasAVX512() && ST->hasEVEX512() && PreferVectorWidth >= 512)
return TypeSize::getFixed(512);
if (ST->hasAVX() && PreferVectorWidth >= 256)
return TypeSize::getFixed(256);
Expand Down Expand Up @@ -6131,7 +6131,8 @@ X86TTIImpl::enableMemCmpExpansion(bool OptSize, bool IsZeroCmp) const {
// Only enable vector loads for equality comparison. Right now the vector
// version is not as fast for three way compare (see #33329).
const unsigned PreferredWidth = ST->getPreferVectorWidth();
if (PreferredWidth >= 512 && ST->hasAVX512()) Options.LoadSizes.push_back(64);
if (PreferredWidth >= 512 && ST->hasAVX512() && ST->hasEVEX512())
Options.LoadSizes.push_back(64);
if (PreferredWidth >= 256 && ST->hasAVX()) Options.LoadSizes.push_back(32);
if (PreferredWidth >= 128 && ST->hasSSE2()) Options.LoadSizes.push_back(16);
}
Expand Down
29 changes: 29 additions & 0 deletions llvm/test/CodeGen/X86/evex512-mem.ll
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@@ -0,0 +1,29 @@
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=x86_64-unknown-unknown -mattr=avx512f,avx512bw,avx512vl < %s | FileCheck %s --check-prefix=AVX512
; RUN: llc -mtriple=x86_64-unknown-unknown -mattr=avx512f,avx512bw,avx512vl,-evex512 < %s | FileCheck %s --check-prefix=AVX256

define void @test1() {
; AVX512-LABEL: test1:
; AVX512: # %bb.0:
; AVX512-NEXT: movq 64, %rax
; AVX512-NEXT: movq %rax, (%rax)
; AVX512-NEXT: vmovups 0, %zmm0
; AVX512-NEXT: vmovups %zmm0, (%rax)
; AVX512-NEXT: vzeroupper
; AVX512-NEXT: retq
;
; AVX256-LABEL: test1:
; AVX256: # %bb.0:
; AVX256-NEXT: movq 64, %rax
; AVX256-NEXT: movq %rax, (%rax)
; AVX256-NEXT: vmovups 0, %ymm0
; AVX256-NEXT: vmovups 32, %ymm1
; AVX256-NEXT: vmovups %ymm1, (%rax)
; AVX256-NEXT: vmovups %ymm0, (%rax)
; AVX256-NEXT: vzeroupper
; AVX256-NEXT: retq
call void @llvm.memcpy.p0.p0.i64(ptr align 8 poison, ptr align 8 null, i64 72, i1 false)
ret void
}

declare void @llvm.memcpy.p0.p0.i64(ptr, ptr, i64, i1)