1; RUN: opt -mergereturn -enable-new-pm=0 -S < %s | FileCheck %s
2; RUN: opt -passes='break-crit-edges,lowerswitch,mergereturn' -S < %s | FileCheck %s
3
4; The pass did previously not report the correct Modified status in the case
5; where a function had at most one return block, and an unified unreachable
6; block was created. This was caught by the pass return status check that is
7; hidden under EXPENSIVE_CHECKS.
8
9; CHECK: for.foo.body2:
10; CHECK-NEXT: br label %UnifiedUnreachableBlock
11
12; CHECK: for.foo.end:
13; CHECK-NEXT: br label %UnifiedUnreachableBlock
14
15; CHECK: UnifiedUnreachableBlock:
16; CHECK-NEXT: unreachable
17
18define i32 @foo() {
19entry:
20  br label %for.foo.cond
21
22for.foo.cond:                                         ; preds = %entry
23  br i1 false, label %for.foo.body, label %for.foo.end3
24
25for.foo.body:                                         ; preds = %for.foo.cond
26  br label %for.foo.cond1
27
28for.foo.cond1:                                        ; preds = %for.foo.body
29  br i1 false, label %for.foo.body2, label %for.foo.end
30
31for.foo.body2:                                        ; preds = %for.foo.cond1
32  unreachable
33
34for.foo.end:                                          ; preds = %for.foo.cond1
35  unreachable
36
37for.foo.end3:                                         ; preds = %for.foo.cond
38  ret i32 undef
39}
40
41; CHECK: for.bar.body2:
42; CHECK-NEXT: br label %UnifiedUnreachableBlock
43
44; CHECK: for.bar.end:
45; CHECK-NEXT: br label %UnifiedUnreachableBlock
46
47; CHECK: UnifiedUnreachableBlock:
48; CHECK-NEXT: unreachable
49
50define void @bar() {
51entry:
52  br label %for.bar.cond
53
54for.bar.cond:                                         ; preds = %entry
55  br i1 false, label %for.bar.body, label %for.bar.end
56
57for.bar.body:                                         ; preds = %for.bar.cond
58  br label %for.bar.cond1
59
60for.bar.cond1:                                        ; preds = %for.bar.body
61  br i1 false, label %for.bar.body2, label %for.bar.end
62
63for.bar.body2:                                        ; preds = %for.bar.cond1
64  unreachable
65
66for.bar.end:                                          ; preds = %for.bar.cond1
67  unreachable
68}
69