[llvm-commits] [llvm] r171346 - /llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp

[Michael Gottesman]

Author: mgottesman
Date: Tue Jan  1 10:05:54 2013
New Revision: 171346

URL: http://llvm.org/viewvc/llvm-project?rev=171346&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp?rev=171346&r1=171345&r2=171346&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp Tue Jan  1 10:05:54 2013
@@ -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;
     }