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.)
llvm-svn: 91621
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index b9c536f..c7359c4 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9896,9 +9896,11 @@
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);
}