/// class implementation is "non-lazy".
bool ImplementationIsNonLazy(const ObjCImplDecl *OD) const;
+ bool IsIvarOffsetKnownIdempotent(const CodeGen::CodeGenFunction &CGF,
+ const ObjCInterfaceDecl *ID,
+ const ObjCIvarDecl *IV) {
+ // Annotate the load as an invariant load iff the object type is the type,
+ // or a derived type, of the class containing the ivar within an ObjC
+ // method. This check is needed because the ivar offset is a lazily
+ // initialised value that may depend on objc_msgSend to perform a fixup on
+ // the first message dispatch.
+ //
+ // An additional opportunity to mark the load as invariant arises when the
+ // base of the ivar access is a parameter to an Objective C method.
+ // However, because the parameters are not available in the current
+ // interface, we cannot perform this check.
+ if (dyn_cast<ObjCMethodDecl>(CGF.CurFuncDecl))
+ if (IV->getContainingInterface()->isSuperClassOf(ID))
+ return true;
+ return false;
+ }
+
public:
CGObjCNonFragileABIMac(CodeGen::CodeGenModule &cgm);
// FIXME. All stubs for now!
unsigned CVRQualifiers) {
ObjCInterfaceDecl *ID = ObjectTy->getAs<ObjCObjectType>()->getInterface();
llvm::Value *Offset = EmitIvarOffset(CGF, ID, Ivar);
- if (llvm::LoadInst *LI = dyn_cast<llvm::LoadInst>(Offset))
- LI->setMetadata(CGM.getModule().getMDKindID("invariant.load"),
- llvm::MDNode::get(VMContext,
- ArrayRef<llvm::Value*>()));
+
+ if (IsIvarOffsetKnownIdempotent(CGF, ID, Ivar))
+ if (llvm::LoadInst *LI = cast<llvm::LoadInst>(Offset))
+ LI->setMetadata(CGM.getModule().getMDKindID("invariant.load"),
+ llvm::MDNode::get(VMContext, ArrayRef<llvm::Value*>()));
+
return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
Offset);
}
--- /dev/null
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -x objective-c %s -o - | FileCheck %s
+
+@interface NSObject
++ (id) new;
+- (id) init;
+@end
+
+@interface Base : NSObject @end
+
+// @implementation Base
+// {
+// int dummy;
+// }
+// @end
+
+@interface Derived : Base
+{
+ @public int member;
+}
+@end
+
+@implementation Derived
+- (id) init
+{
+ self = [super init];
+ member = 42;
+ return self;
+}
+@end
+
+// CHECK: [[IVAR:%.*]] = load i64* @"OBJC_IVAR_$_Derived.member", !invariant.load
+
+void * variant_load_1(int i) {
+ void *ptr;
+ while (i--) {
+ Derived *d = [Derived new];
+ ptr = &d->member;
+ }
+ return ptr;
+}
+
+// CHECK: [[IVAR:%.*]] = load i64* @"OBJC_IVAR_$_Derived.member"{{$}}
+
+@interface Container : Derived @end
+@implementation Container
+- (void *) invariant_load_1
+{
+ return &self->member;
+}
+@end
+
+// CHECK: [[IVAR:%.*]] = load i64* @"OBJC_IVAR_$_Derived.member", !invariant.load
+