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[AMDGPU] Update PromoteAlloca to handle GEPs with variable offset. #122342

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Merged
merged 6 commits into from
Feb 24, 2025
Merged

[AMDGPU] Update PromoteAlloca to handle GEPs with variable offset. #122342

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1093642
[AMDGPU] Update PromoteAlloca to handle GEPs with variable offset.
sgundapa Jan 9, 2025
9b7403a
[AMDGPU] Update PromoteAlloca to handle updated GEP Indexes.
sgundapa Jan 30, 2025
d443b33
Merge branch 'llvm:main' into pro_alloc_crash
sgundapa Feb 10, 2025
13a43bd
[AMDGPU] Update PromoteAlloca to handle changed GEP Indexes.
sgundapa Feb 10, 2025
bf8a22d
Update llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
sgundapa Feb 24, 2025
3e8e15f
clang-format fix
arsenm Feb 24, 2025
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17 changes: 11 additions & 6 deletions llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -385,16 +385,21 @@ static bool isSupportedMemset(MemSetInst *I, AllocaInst *AI,
match(I->getOperand(2), m_SpecificInt(Size)) && !I->isVolatile();
}

static Value *
calculateVectorIndex(Value *Ptr,
const std::map<GetElementPtrInst *, Value *> &GEPIdx) {
static Value *calculateVectorIndex(
Value *Ptr, const std::map<GetElementPtrInst *, WeakTrackingVH> &GEPIdx) {
auto *GEP = dyn_cast<GetElementPtrInst>(Ptr->stripPointerCasts());
if (!GEP)
return ConstantInt::getNullValue(Type::getInt32Ty(Ptr->getContext()));

auto I = GEPIdx.find(GEP);
assert(I != GEPIdx.end() && "Must have entry for GEP!");
return I->second;

if (Value *IndexValue = I->second)
return IndexValue;

llvm_unreachable(
"Index value is not present in Cached GEPs! This indicates a "
"bug in the pass that populates GEPIdx.");
}

static Value *GEPToVectorIndex(GetElementPtrInst *GEP, AllocaInst *Alloca,
Expand Down Expand Up @@ -449,7 +454,7 @@ static Value *promoteAllocaUserToVector(
Instruction *Inst, const DataLayout &DL, FixedVectorType *VectorTy,
unsigned VecStoreSize, unsigned ElementSize,
DenseMap<MemTransferInst *, MemTransferInfo> &TransferInfo,
std::map<GetElementPtrInst *, Value *> &GEPVectorIdx, Value *CurVal,
std::map<GetElementPtrInst *, WeakTrackingVH> &GEPVectorIdx, Value *CurVal,
SmallVectorImpl<LoadInst *> &DeferredLoads) {
// Note: we use InstSimplifyFolder because it can leverage the DataLayout
// to do more folding, especially in the case of vector splats.
Expand Down Expand Up @@ -757,7 +762,7 @@ bool AMDGPUPromoteAllocaImpl::tryPromoteAllocaToVector(AllocaInst &Alloca) {
return false;
}

std::map<GetElementPtrInst *, Value *> GEPVectorIdx;
std::map<GetElementPtrInst *, WeakTrackingVH> GEPVectorIdx;
SmallVector<Instruction *> WorkList;
SmallVector<Instruction *> UsersToRemove;
SmallVector<Instruction *> DeferredInsts;
Expand Down
28 changes: 28 additions & 0 deletions llvm/test/CodeGen/AMDGPU/promote-alloca-array-aggregate.ll
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Expand Up @@ -122,6 +122,34 @@ define amdgpu_vs void @promote_load_from_store_aggr() #0 {
ret void
}

%Block4 = type { [2 x i32], i32 }
@block4 = external addrspace(1) global %Block4
%gl_PV = type { <4 x i32>, i32, [1 x i32], [1 x i32] }
@pv1 = external addrspace(1) global %gl_PV

; This should not crash on an aliased variable offset that can be
; optimized out (variable %aliasTofoo3 in the test)
define amdgpu_vs void @promote_load_from_store_aggr_varoff(<4 x i32> %input) {
; CHECK-LABEL: @promote_load_from_store_aggr_varoff(
; CHECK-NEXT: [[FOO3_UNPACK2:%.*]] = load i32, ptr addrspace(1) getelementptr inbounds (i8, ptr addrspace(1) @block4, i64 8), align 4
; CHECK-NEXT: [[TMP1:%.*]] = insertelement <3 x i32> undef, i32 [[FOO3_UNPACK2]], i32 2
; CHECK-NEXT: [[TMP2:%.*]] = extractelement <3 x i32> [[TMP1]], i32 [[FOO3_UNPACK2]]
; CHECK-NEXT: [[FOO12:%.*]] = insertelement <4 x i32> %input, i32 [[TMP2]], i64 3
; CHECK-NEXT: store <4 x i32> [[FOO12]], ptr addrspace(1) @pv1, align 16
; CHECK-NEXT: ret void
;
%f1 = alloca [3 x i32], align 4, addrspace(5)
%G1 = getelementptr inbounds i8, ptr addrspace(5) %f1, i32 8
%foo3.unpack2 = load i32, ptr addrspace(1) getelementptr inbounds (i8, ptr addrspace(1) @block4, i64 8), align 4
store i32 %foo3.unpack2, ptr addrspace(5) %G1, align 4
%aliasTofoo3 = load i32, ptr addrspace(5) %G1, align 4
%foo5 = getelementptr [3 x i32], ptr addrspace(5) %f1, i32 0, i32 %aliasTofoo3
%foo6 = load i32, ptr addrspace(5) %foo5, align 4
%foo12 = insertelement <4 x i32> %input, i32 %foo6, i64 3
store <4 x i32> %foo12, ptr addrspace(1) @pv1, align 16
ret void
}

define amdgpu_vs void @promote_memmove_aggr() #0 {
; CHECK-LABEL: @promote_memmove_aggr(
; CHECK-NEXT: store float 1.000000e+00, ptr addrspace(1) @pv, align 4
Expand Down
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