Fix new test

Author: arsenm

llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp

@@ -660,13 +660,15 @@ bool ObjCARCContract::run(Function &F, AAResults *A, DominatorTree *D) {
     };
 
     Value *Arg = cast<CallInst>(Inst)->getArgOperand(0);
-
     ReplaceArgUses(Arg);
 
-    Arg = Arg->stripPointerCastsAndAliases();
+    Value *Stripped = Arg->stripPointerCastsAndAliases();
+    if (Stripped != Arg)
+      ReplaceArgUses(Stripped);
+
     // If Arg is a PHI node, get PHIs that are equivalent to it and replace
     // their uses.
-    if (PHINode *PN = dyn_cast<PHINode>(Arg)) {
+    if (PHINode *PN = dyn_cast<PHINode>(Stripped)) {
       SmallVector<Value *, 1> PHIList;
       getEquivalentPHIs(*PN, PHIList);
       for (Value *PHI : PHIList)

llvm/test/Transforms/ObjCARC/contract.ll

@@ -234,6 +234,22 @@ define void @test14(ptr %a, ptr %b) {
   ret void
 }
 
+define void @test15(ptr %x) {
+; CHECK-LABEL: define void @test15(
+; CHECK-SAME: ptr [[X:%.*]]) {
+; CHECK-NEXT:    [[Y:%.*]] = getelementptr inbounds ptr, ptr [[X]], i32 0
+; CHECK-NEXT:    [[V0:%.*]] = call ptr @llvm.objc.retain(ptr [[Y]]) #[[ATTR0:[0-9]+]]
+; CHECK-NEXT:    call void @use_pointer(ptr [[V0]])
+; CHECK-NEXT:    call void @use_pointer(ptr [[V0]])
+; CHECK-NEXT:    ret void
+;
+  %y = getelementptr inbounds ptr, ptr %x, i32 0
+  %v0 = call ptr @llvm.objc.retain(ptr %y) nounwind
+  call void @use_pointer(ptr %x)
+  call void @use_pointer(ptr %y)
+  ret void
+}
+
 declare void @llvm.objc.clang.arc.use(...) nounwind
 declare void @llvm.objc.clang.arc.noop.use(...) nounwind