[InstCombine] Do not fold scalar ops over select with vector condition.

If OtherOpT or OtherOpF have scalar types and the condition is a vector,
we would create an invalid select.

Reviewers: spatel, john.brawn, mssimpso, craig.topper

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D51781

llvm-svn: 341666

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 3b79ea55a21..622b6eace5d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -362,6 +362,14 @@ Instruction *InstCombiner::foldSelectOpOp(SelectInst &SI, Instruction *TI,
     return nullptr;
   }
 
+  // If the select condition is a vector, the operands of the original select's
+  // operands also must be vectors. This may not be the case for getelementptr
+  // for example.
+  if (SI.getCondition()->getType()->isVectorTy() &&
+      (!OtherOpT->getType()->isVectorTy() ||
+       !OtherOpF->getType()->isVectorTy()))
+    return nullptr;
+
   // If we reach here, they do have operations in common.
   Value *NewSI = Builder.CreateSelect(SI.getCondition(), OtherOpT, OtherOpF,
                                       SI.getName() + ".v", &SI);