Objective-C [IRGen]. Generator a tail call to objc_getProperty() in

synthesized getters for performance improvement. 
// rdar://15884113

llvm-svn: 200430

clang/lib/CodeGen/CGObjC.cpp

@@ -892,10 +892,14 @@ CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
 
     // FIXME: We shouldn't need to get the function info here, the
     // runtime already should have computed it to build the function.
+    llvm::Instruction *CallInstruction;
     RValue RV = EmitCall(getTypes().arrangeFreeFunctionCall(propType, args,
                                                        FunctionType::ExtInfo(),
                                                             RequiredArgs::All),
-                         getPropertyFn, ReturnValueSlot(), args);
+                         getPropertyFn, ReturnValueSlot(), args, 0,
+                         &CallInstruction);
+    if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(CallInstruction))
+      call->setTailCall();
 
     // We need to fix the type here. Ivars with copy & retain are
     // always objects so we don't need to worry about complex or

clang/test/CodeGenObjC/arc-property.m

@@ -67,7 +67,7 @@ static Class theGlobalClass;
 
 // CHECK:    define internal i8* @"\01-[Test2 theClass]"(
 // CHECK:      [[OFFSET:%.*]] = load i64* @"OBJC_IVAR_$_Test2._theClass"
-// CHECK-NEXT: [[T0:%.*]] = call i8* @objc_getProperty(i8* {{.*}}, i8* {{.*}}, i64 [[OFFSET]], i1 zeroext true)
+// CHECK-NEXT: [[T0:%.*]] = tail call i8* @objc_getProperty(i8* {{.*}}, i8* {{.*}}, i64 [[OFFSET]], i1 zeroext true)
 // CHECK-NEXT: ret i8* [[T0]]
 
 // CHECK:    define internal void @"\01-[Test2 setTheClass:]"(

clang/test/CodeGenObjC/arc.m

@@ -1004,7 +1004,7 @@ void test37(void) {
 @synthesize x;
 @end
 // CHECK:    define internal i8* @"\01-[Test45 x]"(
-// CHECK:      [[CALL:%.*]] = call i8* @objc_getProperty(
+// CHECK:      [[CALL:%.*]] = tail call i8* @objc_getProperty(
 // CHECK-NEXT: ret i8* [[CALL]]
 
 // rdar://problem/9315552
@@ -1352,7 +1352,7 @@ void test62(void) {
 @implementation Person
 @synthesize address;
 @end
-// CHECK: call i8* @objc_getProperty
+// CHECK: tail call i8* @objc_getProperty
 // CHECK: call void @objc_setProperty 
 
 // Verify that we successfully parse and preserve this attribute in

clang/test/CodeGenObjC/getter-property-mismatch.m

@@ -13,7 +13,7 @@
 @synthesize filenamesToServerLocation=_filenamesToServerLocation;
 @end
 
-// CHECK:  [[CALL:%.*]] = call i8* @objc_getProperty
+// CHECK:  [[CALL:%.*]] = tail call i8* @objc_getProperty
 // CHECK:  [[ONE:%.*]] = bitcast i8* [[CALL:%.*]] to [[T1:%.*]]*
 // CHECK:  [[TWO:%.*]] = bitcast [[T1]]* [[ONE]] to [[T2:%.*]]*
 // CHECK:  ret [[T2]]* [[TWO]]