diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index 45afa63..a9817f1 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1121,6 +1121,10 @@ Instruction *InstCombinerImpl::visitZExt(ZExtInst &Zext) { Value *Src = Zext.getOperand(0); Type *SrcTy = Src->getType(), *DestTy = Zext.getType(); + // zext nneg bool x -> 0 + if (SrcTy->isIntOrIntVectorTy(1) && Zext.hasNonNeg()) + return replaceInstUsesWith(Zext, Constant::getNullValue(Zext.getType())); + // Try to extend the entire expression tree to the wide destination type. unsigned BitsToClear; if (shouldChangeType(SrcTy, DestTy) && |