Actually check memcpy lengths, instead of just commenting about
how they should be checked.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123999 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 0d3c5c7..acddf08 100644
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -690,8 +690,10 @@
// Second, the length of the memcpy's must be the same, or the preceeding one
// must be larger than the following one.
- ConstantInt *C1 = dyn_cast<ConstantInt>(MDep->getLength());
- if (!C1) return false;
+ ConstantInt *MDepLen = dyn_cast<ConstantInt>(MDep->getLength());
+ ConstantInt *MLen = dyn_cast<ConstantInt>(M->getLength());
+ if (!MDepLen || !MLen || MDepLen->getZExtValue() < MLen->getZExtValue())
+ return false;
AliasAnalysis &AA = getAnalysis<AliasAnalysis>();