const Value *Pointer =
StripPointerCastsAndObjCCalls(LI->getPointerOperand());
if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Pointer)) {
+ // A constant pointer can't be pointing to an object on the heap. It may
+ // be reference-counted, but it won't be deleted.
+ if (GV->isConstant())
+ return true;
StringRef Name = GV->getName();
// These special variables are known to hold values which are not
// reference-counted pointers.
// regardless of what possible decrements or uses lie between them.
bool KnownSafe = isa<Constant>(Arg) || isa<AllocaInst>(Arg);
+ // A constant pointer can't be pointing to an object on the heap. It may
+ // be reference-counted, but it won't be deleted.
+ if (const LoadInst *LI = dyn_cast<LoadInst>(Arg))
+ if (const GlobalVariable *GV =
+ dyn_cast<GlobalVariable>(
+ StripPointerCastsAndObjCCalls(LI->getPointerOperand())))
+ if (GV->isConstant())
+ KnownSafe = true;
+
// If a pair happens in a region where it is known that the reference count
// is already incremented, we can similarly ignore possible decrements.
bool KnownSafeTD = true, KnownSafeBU = true;
ret void
}
+; Constant pointers to objects don't need reference counting.
+
+@constptr = external constant i8*
+@something = external global i8*
+
+; CHECK: define void @test60(
+; CHECK-NOT: @objc_
+; CHECK: }
+define void @test60() {
+ %t = load i8** @constptr
+ %s = load i8** @something
+ call i8* @objc_retain(i8* %s)
+ call void @callee()
+ call void @use_pointer(i8* %t)
+ call void @objc_release(i8* %s)
+ ret void
+}
+
+; Constant pointers to objects don't need to be considered related to other
+; pointers.
+
+; CHECK: define void @test61(
+; CHECK-NOT: @objc_
+; CHECK: }
+define void @test61() {
+ %t = load i8** @constptr
+ call i8* @objc_retain(i8* %t)
+ call void @callee()
+ call void @use_pointer(i8* %t)
+ call void @objc_release(i8* %t)
+ ret void
+}
+
declare void @bar(i32 ()*)
; A few real-world testcases.