[llvm] 007f268 - [VectorCombine] Check indices for all extracts we scalarize.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2021-05-28T18:35:29+01:00
New Revision: 007f268c35fcd9428ba13f3a9f288b997278c1a4

URL: https://github.com/llvm/llvm-project/commit/007f268c35fcd9428ba13f3a9f288b997278c1a4
DIFF: https://github.com/llvm/llvm-project/commit/007f268c35fcd9428ba13f3a9f288b997278c1a4.diff

LOG: [VectorCombine] Check indices for all extracts we scalarize.

We need to make sure that the indices of all extracts we scalarize are
valid.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VectorCombine.cpp
    llvm/test/Transforms/VectorCombine/AArch64/load-extractelement-scalarization.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
index 182495615d346..9f3ca224f8468 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -858,9 +858,6 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
   if (!FixedVT)
     return false;
 
-  if (!canScalarizeAccess(FixedVT, Idx, &I, AC))
-    return false;
-
   InstructionCost OriginalCost = TTI.getMemoryOpCost(
       Instruction::Load, LI->getType(), Align(LI->getAlignment()),
       LI->getPointerAddressSpace());
@@ -894,6 +891,9 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
     else if (LastCheckedInst->comesBefore(UI))
       LastCheckedInst = UI;
 
+    if (!canScalarizeAccess(FixedVT, UI->getOperand(1), &I, AC))
+      return false;
+
     auto *Index = dyn_cast<ConstantInt>(UI->getOperand(1));
     OriginalCost +=
         TTI.getVectorInstrCost(Instruction::ExtractElement, LI->getType(),

diff  --git a/llvm/test/Transforms/VectorCombine/AArch64/load-extractelement-scalarization.ll b/llvm/test/Transforms/VectorCombine/AArch64/load-extractelement-scalarization.ll
index e927311849a37..b18d55d4d44ac 100644
--- a/llvm/test/Transforms/VectorCombine/AArch64/load-extractelement-scalarization.ll
+++ b/llvm/test/Transforms/VectorCombine/AArch64/load-extractelement-scalarization.ll
@@ -476,10 +476,9 @@ define i32 @load_multiple_extracts_with_variable_indices_large_vector_only_first
 ; CHECK-LABEL: @load_multiple_extracts_with_variable_indices_large_vector_only_first_valid(
 ; CHECK-NEXT:    [[CMP_IDX_0:%.*]] = icmp ult i64 [[IDX_0:%.*]], 16
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP_IDX_0]])
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds <16 x i32>, <16 x i32>* [[X:%.*]], i32 0, i64 [[IDX_0]]
-; CHECK-NEXT:    [[E_0:%.*]] = load i32, i32* [[TMP1]], align 4
-; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds <16 x i32>, <16 x i32>* [[X]], i32 0, i64 [[IDX_1:%.*]]
-; CHECK-NEXT:    [[E_1:%.*]] = load i32, i32* [[TMP2]], align 4
+; CHECK-NEXT:    [[LV:%.*]] = load <16 x i32>, <16 x i32>* [[X:%.*]], align 64
+; CHECK-NEXT:    [[E_0:%.*]] = extractelement <16 x i32> [[LV]], i64 [[IDX_0]]
+; CHECK-NEXT:    [[E_1:%.*]] = extractelement <16 x i32> [[LV]], i64 [[IDX_1:%.*]]
 ; CHECK-NEXT:    [[RES:%.*]] = add i32 [[E_0]], [[E_1]]
 ; CHECK-NEXT:    ret i32 [[RES]]
 ;