1; RUN: opt -S -loop-rotate < %s -verify-loop-info | FileCheck %s
2;
3; Verify that LoopRotate preserves LoopSimplify form even in very peculiar loop
4; structures. We manually validate the CFG with FileCheck because currently we
5; can't cause a failure when LoopSimplify fails to be preserved.
6
7define void @PR18643() {
8; CHECK-LABEL: @PR18643(
9entry:
10  br label %outer.header
11; CHECK: br label %outer.header
12
13outer.header:
14; CHECK: outer.header:
15  br i1 undef, label %inner.header, label %outer.body
16; CHECK-NEXT: br i1 {{[^,]*}}, label %[[INNER_PREROTATE_PREHEADER:[^,]*]], label %outer.body
17
18; CHECK: [[INNER_PREROTATE_PREHEADER]]:
19; CHECK-NEXT: br i1 {{[^,]*}}, label %[[INNER_PREROTATE_PREHEADER_SPLIT_RETURN:[^,]*]], label %[[INNER_ROTATED_PREHEADER:[^,]*]]
20
21; CHECK: [[INNER_ROTATED_PREHEADER]]:
22; CHECK-NEXT: br label %inner.body
23
24inner.header:
25; Now the latch!
26; CHECK: inner.header:
27  br i1 undef, label %return, label %inner.body
28; CHECK-NEXT: br i1 {{[^,]*}}, label %[[INNER_SPLIT_RETURN:[^,]*]], label %inner.body
29
30inner.body:
31; Now the header!
32; CHECK: inner.body:
33  br i1 undef, label %outer.latch, label %inner.latch
34; CHECK-NEXT: br i1 {{[^,]*}}, label %[[INNER_SPLIT_OUTER_LATCH:[^,]*]], label %inner.header
35
36inner.latch:
37; Dead!
38  br label %inner.header
39
40outer.body:
41; CHECK: outer.body:
42  br label %outer.latch
43; CHECK-NEXT: br label %outer.latch
44
45; L2 -> L1 exit edge needs a simplified exit block.
46; CHECK: [[INNER_SPLIT_OUTER_LATCH]]:
47; CHECK-NEXT: br label %outer.latch
48
49outer.latch:
50; CHECK: outer.latch:
51  br label %outer.header
52; CHECK-NEXT: br label %outer.header
53
54; L1 -> L0 exit edge need sa simplified exit block.
55; CHECK: [[INNER_PREROTATE_PREHEADER_SPLIT_RETURN]]:
56; CHECK-NEXT: br label %return
57
58; L2 -> L0 exit edge needs a simplified exit block.
59; CHECK: [[INNER_SPLIT_RETURN]]:
60; CHECK-NEXT: br label %return
61
62return:
63; CHECK: return:
64  unreachable
65}
66