[InstCombine] Determine the result of a select based on a dominating condition.

Differential Revision: http://reviews.llvm.org/D19550

llvm-svn: 268104

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index feddbafa0d5..4097322a2b9 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -3941,7 +3941,10 @@ Optional<bool> llvm::isImpliedCondition(Value *LHS, Value *RHS,
                                         unsigned Depth, AssumptionCache *AC,
                                         const Instruction *CxtI,
                                         const DominatorTree *DT) {
-  assert(LHS->getType() == RHS->getType() && "mismatched type");
+  // A mismatch occurs when we compare a scalar cmp to a vector cmp, for example.
+  if (LHS->getType() != RHS->getType())
+    return None;
+
   Type *OpTy = LHS->getType();
   assert(OpTy->getScalarType()->isIntegerTy(1));