1; REQUIRES: asserts
2; RUN: opt -loop-unswitch -enable-new-pm=0 -disable-output -stats -info-output-file - < %s | FileCheck --check-prefix=STATS %s
3; RUN: opt -loop-unswitch -enable-new-pm=0 -enable-mssa-loop-dependency=true -verify-memoryssa -disable-output -stats -info-output-file - < %s | FileCheck --check-prefix=STATS %s
4; RUN: opt -loop-unswitch -enable-new-pm=0 -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S < %s | FileCheck %s
5; PR5373
6
7; Loop unswitching shouldn't trivially unswitch the true case of condition %a
8; in the code here because it leads to an infinite loop. While this doesn't
9; contain any instructions with side effects, it's still a kind of side effect.
10; It can trivially unswitch on the false case of condition %a though.
11
12; STATS: 2 loop-unswitch - Number of branches unswitched
13; STATS: 2 loop-unswitch - Number of unswitches that are trivial
14
15; CHECK-LABEL: @func_16(
16; CHECK-NEXT: entry:
17; CHECK-NEXT: br i1 %a, label %entry.split, label %abort0.split
18
19; CHECK: entry.split:
20; CHECK-NEXT: br i1 %b, label %for.body, label %abort1.split
21
22; CHECK: for.body:
23; CHECK-NEXT: br label %for.body
24
25; CHECK: abort0.split:
26; CHECK-NEXT: call void @end0() [[NOR_NUW:#[0-9]+]]
27; CHECK-NEXT: unreachable
28
29; CHECK: abort1.split:
30; CHECK-NEXT: call void @end1() [[NOR_NUW]]
31; CHECK-NEXT: unreachable
32
33; CHECK: }
34
35define void @func_16(i1 %a, i1 %b) nounwind {
36entry:
37  br label %for.body
38
39for.body:
40  br i1 %a, label %cond.end, label %abort0
41
42cond.end:
43  br i1 %b, label %for.body, label %abort1
44
45abort0:
46  call void @end0() noreturn nounwind
47  unreachable
48
49abort1:
50  call void @end1() noreturn nounwind
51  unreachable
52}
53
54declare void @end0() noreturn
55declare void @end1() noreturn
56
57; CHECK: attributes #0 = { nounwind }
58; CHECK: attributes #1 = { noreturn }
59; CHECK: attributes [[NOR_NUW]] = { noreturn nounwind }
60