Code: 

@interface AClass : NSObject @end

@implementation AClass {
    id ivar;
}

- (void)aMethod {
	ivar = @1;
}

- (void)test {
	id local = ivar;
	[self aMethod];
	@[local, ivar];
}

@end

Before:
We store the local into the temporary buffer on line 12, but release it on line 19 before the buffer is used on line 23.

1  define internal void @"\01-[AClass test]"(%0* %self, i8* nocapture %_cmd) #0 {
2    %1 = alloca [2 x i8*], align 8
3    %2 = load i64* @"OBJC_IVAR_$_AClass.ivar", align 8, !invariant.load !4
4    %3 = bitcast %0* %self to i8*
5    %4 = getelementptr inbounds i8* %3, i64 %2
6    %5 = bitcast i8* %4 to i8**
7    %6 = load i8** %5, align 8, !tbaa !5
8    %7 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_2", align 8, !invariant.load !4
9    %8 = tail call i8* @objc_retain(i8* %6) #3
10   call void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*)*)(i8* %3, i8* %7), !clang.arc.no_objc_arc_exceptions !4
11   %9 = getelementptr inbounds [2 x i8*]* %1, i64 0, i64 0
12   store i8* %6, i8** %9, align 8
13   %10 = getelementptr inbounds [2 x i8*]* %1, i64 0, i64 1
14   %11 = load i64* @"OBJC_IVAR_$_AClass.ivar", align 8, !invariant.load !4
15   %12 = getelementptr inbounds i8* %3, i64 %11
16   %13 = bitcast i8* %12 to i8**
17   %14 = load i8** %13, align 8, !tbaa !5
18   call void @objc_release(i8* %6) #3, !clang.imprecise_release !4
19   store i8* %14, i8** %10, align 8
20   %15 = load %struct._class_t** @"\01L_OBJC_CLASSLIST_REFERENCES_$_3", align 8
21   %16 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_5", align 8, !invariant.load !4
22   %17 = bitcast %struct._class_t* %15 to i8*
23   %18 = call i8* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i8* (i8*, i8*, i8**, i64)*)(i8* %17, i8* %16, i8** %9, i64 2), !clang.arc.no_objc_arc_exceptions !4
24   %19 = tail call i8* @objc_retainAutoreleasedReturnValue(i8* %18) #3
25   call void @objc_release(i8* %18) #3
26   ret void
27 }

After:
The release is gone, and there's an array cleanup instead.

1  define internal void @"\01-[AClass test]"(%0* %self, i8* nocapture %_cmd) #0 {
2  entry:
3    %objects = alloca [2 x i8*], align 8
4    %ivar = load i64* @"OBJC_IVAR_$_AClass.ivar", align 8, !invariant.load !4
5    %0 = bitcast %0* %self to i8*
6    %add.ptr = getelementptr inbounds i8* %0, i64 %ivar
7    %1 = bitcast i8* %add.ptr to i8**
8    %2 = load i8** %1, align 8, !tbaa !5
9    %3 = tail call i8* @objc_retain(i8* %2) #3
10   %4 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_2", align 8, !invariant.load !4
11   call void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*)*)(i8* %0, i8* %4), !clang.arc.no_objc_arc_exceptions !4
12   %5 = getelementptr inbounds [2 x i8*]* %objects, i64 0, i64 0
13   %6 = tail call i8* @objc_retain(i8* %2) #3
14   store i8* %2, i8** %5, align 8
15   %7 = getelementptr inbounds [2 x i8*]* %objects, i64 0, i64 1
16   %ivar1 = load i64* @"OBJC_IVAR_$_AClass.ivar", align 8, !invariant.load !4
17   %add.ptr2 = getelementptr inbounds i8* %0, i64 %ivar1
18   %8 = bitcast i8* %add.ptr2 to i8**
19   %9 = load i8** %8, align 8, !tbaa !5
20   %10 = tail call i8* @objc_retain(i8* %9) #3
21   store i8* %9, i8** %7, align 8
22   %11 = load %struct._class_t** @"\01L_OBJC_CLASSLIST_REFERENCES_$_3", align 8
23   %12 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_5", align 8, !invariant.load !4
24   %13 = bitcast %struct._class_t* %11 to i8*
25   %call = call i8* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i8* (i8*, i8*, i8**, i64)*)(i8* %13, i8* %12, i8** %5, i64 2), !clang.arc.no_objc_arc_exceptions !4
26   %14 = tail call i8* @objc_retainAutoreleasedReturnValue(i8* %call) #3
27   call void @objc_release(i8* %call) #3
28   %15 = getelementptr inbounds [2 x i8*]* %objects, i64 0, i64 2
29   br label %arraydestroy.body
30 
31 arraydestroy.body:                                ; preds = %arraydestroy.body, %entry
32   %arraydestroy.elementPast = phi i8** [ %15, %entry ], [ %arraydestroy.element, %arraydestroy.body ]
33   %arraydestroy.element = getelementptr inbounds i8** %arraydestroy.elementPast, i64 -1
34   %16 = load i8** %arraydestroy.element, align 8
35   call void @objc_release(i8* %16) #3, !clang.imprecise_release !4
36   %arraydestroy.done = icmp eq i8** %arraydestroy.element, %5
37   br i1 %arraydestroy.done, label %arraydestroy.done3, label %arraydestroy.body
38 
39 arraydestroy.done3:                               ; preds = %arraydestroy.body
40   call void @objc_release(i8* %2) #3, !clang.imprecise_release !4
41   ret void
42 }