From 38b098be6605494cc7308ea9b08f920c4c3fe4ce Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Thu, 5 Aug 2021 14:50:37 +0100 Subject: [PATCH] [VectorCombine] Limit scalarization known non-poison indices. We can only trust the range of the index if it is guaranteed non-poison. Fixes PR50949. Reviewed By: lebedev.ri Differential Revision: https://reviews.llvm.org/D107364 --- llvm/lib/Transforms/Vectorize/VectorCombine.cpp | 3 +++ llvm/test/Transforms/VectorCombine/load-insert-store.ll | 10 ++++++---- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp index d18bcd3..e138e89 100644 --- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp +++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp @@ -781,6 +781,9 @@ static bool canScalarizeAccess(FixedVectorType *VecTy, Value *Idx, if (auto *C = dyn_cast(Idx)) return C->getValue().ult(VecTy->getNumElements()); + if (!isGuaranteedNotToBePoison(Idx, &AC)) + return false; + APInt Zero(Idx->getType()->getScalarSizeInBits(), 0); APInt MaxElts(Idx->getType()->getScalarSizeInBits(), VecTy->getNumElements()); ConstantRange ValidIndices(Zero, MaxElts); diff --git a/llvm/test/Transforms/VectorCombine/load-insert-store.ll b/llvm/test/Transforms/VectorCombine/load-insert-store.ll index 93ad6e7..5c3f165 100644 --- a/llvm/test/Transforms/VectorCombine/load-insert-store.ll +++ b/llvm/test/Transforms/VectorCombine/load-insert-store.ll @@ -310,9 +310,10 @@ entry: define void @insert_store_nonconst_index_known_valid_by_and_but_may_be_poison(<16 x i8>* %q, i8 zeroext %s, i32 %idx) { ; CHECK-LABEL: @insert_store_nonconst_index_known_valid_by_and_but_may_be_poison( ; CHECK-NEXT: entry: +; CHECK-NEXT: [[TMP0:%.*]] = load <16 x i8>, <16 x i8>* [[Q:%.*]], align 16 ; CHECK-NEXT: [[IDX_CLAMPED:%.*]] = and i32 [[IDX:%.*]], 7 -; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds <16 x i8>, <16 x i8>* [[Q:%.*]], i32 0, i32 [[IDX_CLAMPED]] -; CHECK-NEXT: store i8 [[S:%.*]], i8* [[TMP0]], align 1 +; CHECK-NEXT: [[VECINS:%.*]] = insertelement <16 x i8> [[TMP0]], i8 [[S:%.*]], i32 [[IDX_CLAMPED]] +; CHECK-NEXT: store <16 x i8> [[VECINS]], <16 x i8>* [[Q]], align 16 ; CHECK-NEXT: ret void ; entry: @@ -412,9 +413,10 @@ entry: define void @insert_store_nonconst_index_known_valid_by_urem_but_may_be_poison(<16 x i8>* %q, i8 zeroext %s, i32 %idx) { ; CHECK-LABEL: @insert_store_nonconst_index_known_valid_by_urem_but_may_be_poison( ; CHECK-NEXT: entry: +; CHECK-NEXT: [[TMP0:%.*]] = load <16 x i8>, <16 x i8>* [[Q:%.*]], align 16 ; CHECK-NEXT: [[IDX_CLAMPED:%.*]] = urem i32 [[IDX:%.*]], 16 -; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds <16 x i8>, <16 x i8>* [[Q:%.*]], i32 0, i32 [[IDX_CLAMPED]] -; CHECK-NEXT: store i8 [[S:%.*]], i8* [[TMP0]], align 1 +; CHECK-NEXT: [[VECINS:%.*]] = insertelement <16 x i8> [[TMP0]], i8 [[S:%.*]], i32 [[IDX_CLAMPED]] +; CHECK-NEXT: store <16 x i8> [[VECINS]], <16 x i8>* [[Q]], align 16 ; CHECK-NEXT: ret void ; entry: -- 2.7.4