[InstCombine] handle zero constant vectors for LE/GE comparisons too

Enhancement to: http://reviews.llvm.org/rL269426
With discussion in: http://reviews.llvm.org/D17859

This should complete the fixes for: PR26701, PR26819:
https://llvm.org/bugs/show_bug.cgi?id=26701
https://llvm.org/bugs/show_bug.cgi?id=26819
 

llvm-svn: 269439

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index acc03e722f0..e06ec3945e3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -3130,8 +3130,9 @@ static ICmpInst *canonicalizeCmpWithConstant(ICmpInst &I,
   }
 
   // The usual vector types are ConstantDataVector. Exotic vector types are
-  // ConstantVector. They both derive from Constant.
-  if (isa<ConstantDataVector>(Op1) || isa<ConstantVector>(Op1)) {
+  // ConstantVector. Zeros are special. They all derive from Constant.
+  if (isa<ConstantDataVector>(Op1) || isa<ConstantVector>(Op1) ||
+      isa<ConstantAggregateZero>(Op1)) {
     Constant *Op1C = cast<Constant>(Op1);
     Type *Op1Type = Op1->getType();
     unsigned NumElts = Op1Type->getVectorNumElements();