[InstCombine] fix opcode check in shuffle fold

There's no way to expose this difference currently,
but we should use the updated variable because the
original opcodes can go stale if we transform into
something new.

llvm-svn: 335920

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index 458b0f0..d4fb086 100644 (file)
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -1199,7 +1199,7 @@ static Instruction *foldSelectShuffles(ShuffleVectorInst &Shuf) {
   // If the shuffle mask contains undef elements, then the new constant
   // vector will have undefs in those lanes. This could cause the entire
   // binop to be undef.
-  if (B0->isIntDivRem())
+  if (Instruction::isIntDivRem(BOpc))
     NewC = getSafeVectorConstantForIntDivRem(NewC);
 
   Instruction *NewBO = ConstantsAreOp1 ? BinaryOperator::Create(BOpc, X, NewC) :