Fix a bug in memcpyopt where the memcpy-memcpy transform was never being applied because
we were checking for it in the wrong order. This caused a miscompilation because the
return slot optimization assumes that the call it is dealing with is NOT a memcpy.
llvm-svn: 50444
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index d2723ab..9a39c8f 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -615,10 +615,12 @@
if (dep == MemoryDependenceAnalysis::None ||
dep == MemoryDependenceAnalysis::NonLocal)
return false;
- else if (CallInst* C = dyn_cast<CallInst>(dep))
- return performCallSlotOptzn(M, C);
- else if (!isa<MemCpyInst>(dep))
- return false;
+ else if (!isa<MemCpyInst>(dep)) {
+ if (CallInst* C = dyn_cast<CallInst>(dep))
+ return performCallSlotOptzn(M, C);
+ else
+ return false;
+ }
MemCpyInst* MDep = cast<MemCpyInst>(dep);