[llvm-commits] [llvm] r137402 - in /llvm/trunk: lib/Transforms/Scalar/ObjCARC.cpp test/Transforms/ObjCARC/rv.ll

[Dan Gohman]

Author: djg
Date: Thu Aug 11 19:36:31 2011
New Revision: 137402

URL: http://llvm.org/viewvc/llvm-project?rev=137402&view=rev
Log:
Don't convert objc_autoreleaseReturnValue to objc_autorelease if the result
is returned through a bitcast.

Modified:
    llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
    llvm/trunk/test/Transforms/ObjCARC/rv.ll

Modified: llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp?rev=137402&r1=137401&r2=137402&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp Thu Aug 11 19:36:31 2011
@@ -1925,12 +1925,19 @@
 ObjCARCOpt::OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV) {
   // Check for a return of the pointer value.
   const Value *Ptr = GetObjCArg(AutoreleaseRV);
-  for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end();
-       UI != UE; ++UI) {
-    const User *I = *UI;
-    if (isa<ReturnInst>(I) || GetBasicInstructionClass(I) == IC_RetainRV)
-      return;
-  }
+  SmallVector<const Value *, 2> Users;
+  Users.push_back(Ptr);
+  do {
+    Ptr = Users.pop_back_val();
+    for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end();
+         UI != UE; ++UI) {
+      const User *I = *UI;
+      if (isa<ReturnInst>(I) || GetBasicInstructionClass(I) == IC_RetainRV)
+        return;
+      if (isa<BitCastInst>(I))
+        Users.push_back(I);
+    }
+  } while (!Users.empty());
 
   Changed = true;
   ++NumPeeps;

Modified: llvm/trunk/test/Transforms/ObjCARC/rv.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/rv.ll?rev=137402&r1=137401&r2=137402&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/rv.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/rv.ll Thu Aug 11 19:36:31 2011
@@ -329,3 +329,14 @@
   call i8* @objc_autoreleaseReturnValue(i8* %p)
   ret void
 }
+
+; Don't convert autoreleaseRV to autorelease if the result is returned,
+; even through a bitcast.
+
+; CHECK: define {}* @test24(
+; CHECK: tail call i8* @objc_autoreleaseReturnValue(i8* %p)
+define {}* @test24(i8* %p) {
+  %t = call i8* @objc_autoreleaseReturnValue(i8* %p)
+  %s = bitcast i8* %p to {}*
+  ret {}* %s
+}