xref: /llvm-project/llvm/test/Analysis/GlobalsModRef/global-used-by-global.ll (revision 47f0b6630c78ab52c2197ec5e1c2d13a6acffed1)
1; RUN: opt < %s -aa-pipeline=globals-aa -passes='require<globals-aa>,gvn' -S | FileCheck %s
2
3target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
4
5@a = internal global ptr null, align 8
6@b = global ptr @a, align 8
7@c = global ptr @a, align 8
8@d = common global i32 0, align 4
9
10; Make sure we globals-aa doesn't get confused and allow hoisting
11; the load from @a out of the loop.
12
13; CHECK-LABEL: define i32 @main()
14; CHECK: for.body:
15; CHECK-NEXT:   %2 = load ptr, ptr @b, align 8
16; CHECK-NEXT:   store ptr @d, ptr %2, align 8
17; CHECK-NEXT:   %3 = load ptr, ptr @a, align 8
18; CHECK-NEXT:   %cmp1 = icmp ne ptr %3, @d
19; CHECK-NEXT:   br i1 %cmp1, label %if.then, label %if.end
20
21define i32 @main() {
22entry:
23  %0 = load i32, ptr @d, align 4
24  br label %for.cond
25
26for.cond:                                         ; preds = %if.end, %entry
27  %1 = phi i32 [ %inc, %if.end ], [ %0, %entry ]
28  %cmp = icmp slt i32 %1, 1
29  br i1 %cmp, label %for.body, label %for.end
30
31for.body:                                         ; preds = %for.cond
32  %2 = load ptr, ptr @b, align 8
33  store ptr @d, ptr %2, align 8
34  %3 = load ptr, ptr @a, align 8
35  %cmp1 = icmp ne ptr %3, @d
36  br i1 %cmp1, label %if.then, label %if.end
37
38if.then:                                          ; preds = %for.body
39  br label %return
40
41if.end:                                           ; preds = %for.body
42  %4 = load i32, ptr @d, align 4
43  %inc = add nsw i32 %4, 1
44  store i32 %inc, ptr @d, align 4
45  br label %for.cond
46
47for.end:                                          ; preds = %for.cond
48  br label %return
49
50return:                                           ; preds = %for.end, %if.then
51  %retval.0 = phi i32 [ 1, %if.then ], [ 0, %for.end ]
52  ret i32 %retval.0
53}
54
55