[InstCombine] Handle vector gep with scalar argument in evaluateInDifferentElementOrder

This fixes PR41270.

The recursive function evaluateInDifferentElementOrder expects to be called
on a vector Value, so when we call it on a vector GEP's arguments, we must
first check that the argument is indeed a vector.

llvm-svn: 357385

1 files changed, 8 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index 49c29fe651b..665064c4c8d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -1171,7 +1171,14 @@ static Value *evaluateInDifferentElementOrder(Value *V, ArrayRef<int> Mask) {
       SmallVector<Value*, 8> NewOps;
       bool NeedsRebuild = (Mask.size() != I->getType()->getVectorNumElements());
       for (int i = 0, e = I->getNumOperands(); i != e; ++i) {
-        Value *V = evaluateInDifferentElementOrder(I->getOperand(i), Mask);
+        Value *V;
+        // Recursively call evaluateInDifferentElementOrder on vector arguments
+        // as well. E.g. GetElementPtr may have scalar operands even if the
+        // return value is a vector, so we need to examine the operand type.
+        if (I->getOperand(i)->getType()->isVectorTy())
+          V = evaluateInDifferentElementOrder(I->getOperand(i), Mask);
+        else
+          V = I->getOperand(i);
         NewOps.push_back(V);
         NeedsRebuild |= (V != I->getOperand(i));
       }