diff options
Diffstat (limited to 'llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp index 6e858d61fef..4e82e2bd42c 100644 --- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -413,7 +413,10 @@ Instruction *MemCpyOptPass::tryMergingIntoMemset(Instruction *StartInst, if (!NextStore->isSimple()) break; // Check to see if this stored value is of the same byte-splattable value. - if (ByteVal != isBytewiseValue(NextStore->getOperand(0))) + Value *StoredByte = isBytewiseValue(NextStore->getOperand(0)); + if (isa<UndefValue>(ByteVal) && StoredByte) + ByteVal = StoredByte; + if (ByteVal != StoredByte) break; // Check to see if this store is to a constant offset from the start ptr. |
