Slightly generalize transformation of memmove(a,a,n) so that it also applies

to memcpy. (Such a memcpy is technically illegal, but in practice is safe
and is generated by struct self-assignment in C code.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91621 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index b9c536fe1e..c7359c4de7 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9896,9 +9896,11 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
                         Intrinsic::getDeclaration(M, MemCpyID, Tys, 1));
           Changed = true;
         }
+    }
 
+    if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
       // memmove(x,x,size) -> noop.
-      if (MMI->getSource() == MMI->getDest())
+      if (MTI->getSource() == MTI->getDest())
         return EraseInstFromFunction(CI);
     }