xref: /llvm-project/llvm/test/Analysis/GlobalsModRef/dead-uses.ll (revision 47f0b6630c78ab52c2197ec5e1c2d13a6acffed1)
1; RUN: opt < %s -aa-pipeline=basic-aa,globals-aa -passes='function(instcombine),require<globals-aa>,function(invalidate<aa>,loop-mssa(licm))' -S | FileCheck %s
2
3; Make sure -globals-aa ignores dead uses of globals.
4
5@a = internal global i32 0, align 4
6@c = common global i32 0, align 4
7
8; Function Attrs: nounwind
9define i32 @g() {
10; Make sure the load of @a is hoisted.
11; CHECK-LABEL: define i32 @g()
12; CHECK: entry:
13; CHECK-NEXT: load i32, ptr @a, align 4
14; CHECK-NEXT: br label %for.cond
15entry:
16  br label %for.cond
17
18for.cond:                                         ; preds = %for.inc, %entry
19  %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
20  %sum.0 = phi i32 [ 0, %entry ], [ %add, %for.inc ]
21  %cmp = icmp slt i32 %i.0, 1000
22  br i1 %cmp, label %for.body, label %for.end
23
24for.body:                                         ; preds = %for.cond
25  %0 = load i32, ptr @a, align 4
26  %add = add nsw i32 %sum.0, %0
27  call void @f()
28  br label %for.inc
29
30for.inc:                                          ; preds = %for.body
31  %inc = add nsw i32 %i.0, 1
32  br label %for.cond
33
34for.end:                                          ; preds = %for.cond
35  ret i32 %sum.0
36}
37
38; Function Attrs: nounwind
39define internal void @f() {
40entry:
41  %tobool = icmp ne i32 0, 0
42  br i1 %tobool, label %if.then, label %if.end
43
44if.then:                                          ; preds = %entry
45  store i32 ptrtoint (ptr @a to i32), ptr @c, align 4
46  br label %if.end
47
48if.end:                                           ; preds = %if.then, %entry
49  %0 = load i32, ptr @c, align 4
50  %inc = add nsw i32 %0, 1
51  store i32 %inc, ptr @c, align 4
52  ret void
53}
54
55