xref: /aosp_15_r20/external/llvm/test/Transforms/LoopUnswitch/infinite-loop.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; REQUIRES: asserts
2*9880d681SAndroid Build Coastguard Worker; RUN: opt -loop-unswitch -disable-output -stats -info-output-file - < %s | FileCheck --check-prefix=STATS %s
3*9880d681SAndroid Build Coastguard Worker; RUN: opt -loop-unswitch -simplifycfg -S < %s | FileCheck %s
4*9880d681SAndroid Build Coastguard Worker; PR5373
5*9880d681SAndroid Build Coastguard Worker
6*9880d681SAndroid Build Coastguard Worker; Loop unswitching shouldn't trivially unswitch the true case of condition %a
7*9880d681SAndroid Build Coastguard Worker; in the code here because it leads to an infinite loop. While this doesn't
8*9880d681SAndroid Build Coastguard Worker; contain any instructions with side effects, it's still a kind of side effect.
9*9880d681SAndroid Build Coastguard Worker; It can trivially unswitch on the false cas of condition %a though.
10*9880d681SAndroid Build Coastguard Worker
11*9880d681SAndroid Build Coastguard Worker; STATS: 2 loop-unswitch - Number of branches unswitched
12*9880d681SAndroid Build Coastguard Worker; STATS: 2 loop-unswitch - Number of unswitches that are trivial
13*9880d681SAndroid Build Coastguard Worker
14*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @func_16(
15*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: entry:
16*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: br i1 %a, label %entry.split, label %abort0.split
17*9880d681SAndroid Build Coastguard Worker
18*9880d681SAndroid Build Coastguard Worker; CHECK: entry.split:
19*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: br i1 %b, label %for.body, label %abort1.split
20*9880d681SAndroid Build Coastguard Worker
21*9880d681SAndroid Build Coastguard Worker; CHECK: for.body:
22*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: br label %for.body
23*9880d681SAndroid Build Coastguard Worker
24*9880d681SAndroid Build Coastguard Worker; CHECK: abort0.split:
25*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: call void @end0() [[NOR_NUW:#[0-9]+]]
26*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: unreachable
27*9880d681SAndroid Build Coastguard Worker
28*9880d681SAndroid Build Coastguard Worker; CHECK: abort1.split:
29*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: call void @end1() [[NOR_NUW]]
30*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: unreachable
31*9880d681SAndroid Build Coastguard Worker
32*9880d681SAndroid Build Coastguard Worker; CHECK: }
33*9880d681SAndroid Build Coastguard Worker
34*9880d681SAndroid Build Coastguard Workerdefine void @func_16(i1 %a, i1 %b) nounwind {
35*9880d681SAndroid Build Coastguard Workerentry:
36*9880d681SAndroid Build Coastguard Worker  br label %for.body
37*9880d681SAndroid Build Coastguard Worker
38*9880d681SAndroid Build Coastguard Workerfor.body:
39*9880d681SAndroid Build Coastguard Worker  br i1 %a, label %cond.end, label %abort0
40*9880d681SAndroid Build Coastguard Worker
41*9880d681SAndroid Build Coastguard Workercond.end:
42*9880d681SAndroid Build Coastguard Worker  br i1 %b, label %for.body, label %abort1
43*9880d681SAndroid Build Coastguard Worker
44*9880d681SAndroid Build Coastguard Workerabort0:
45*9880d681SAndroid Build Coastguard Worker  call void @end0() noreturn nounwind
46*9880d681SAndroid Build Coastguard Worker  unreachable
47*9880d681SAndroid Build Coastguard Worker
48*9880d681SAndroid Build Coastguard Workerabort1:
49*9880d681SAndroid Build Coastguard Worker  call void @end1() noreturn nounwind
50*9880d681SAndroid Build Coastguard Worker  unreachable
51*9880d681SAndroid Build Coastguard Worker}
52*9880d681SAndroid Build Coastguard Worker
53*9880d681SAndroid Build Coastguard Workerdeclare void @end0() noreturn
54*9880d681SAndroid Build Coastguard Workerdeclare void @end1() noreturn
55*9880d681SAndroid Build Coastguard Worker
56*9880d681SAndroid Build Coastguard Worker; CHECK: attributes #0 = { nounwind }
57*9880d681SAndroid Build Coastguard Worker; CHECK: attributes #1 = { noreturn }
58*9880d681SAndroid Build Coastguard Worker; CHECK: attributes [[NOR_NUW]] = { noreturn nounwind }
59