Added DEBUG message when ObjCARC replaces a call which returns its argument verbatim with its argument to temporarily undo an optimization.
Specifically these calls return their argument verbatim, as a low-level
optimization. However, this makes high-level optimizations
harder. We undo any uses of this optimization that the front-end
emitted. We redo them later in the contract pass.
llvm-svn: 171346
diff --git a/llvm/lib/Transforms/Scalar/ObjCARC.cpp b/llvm/lib/Transforms/Scalar/ObjCARC.cpp
index 2bc7e2d..3c4aea1 100644
--- a/llvm/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/llvm/lib/Transforms/Scalar/ObjCARC.cpp
@@ -895,14 +895,18 @@
case IC_Autorelease:
case IC_AutoreleaseRV:
case IC_FusedRetainAutorelease:
- case IC_FusedRetainAutoreleaseRV:
+ case IC_FusedRetainAutoreleaseRV: {
// These calls return their argument verbatim, as a low-level
// optimization. However, this makes high-level optimizations
// harder. Undo any uses of this optimization that the front-end
// emitted here. We'll redo them in the contract pass.
Changed = true;
- Inst->replaceAllUsesWith(cast<CallInst>(Inst)->getArgOperand(0));
+ Value *Value = cast<CallInst>(Inst)->getArgOperand(0);
+ DEBUG(dbgs() << "ObjCARCExpand: Old = " << *Inst << "\n"
+ " New = " << *Value << "\n");
+ Inst->replaceAllUsesWith(Value);
break;
+ }
default:
break;
}