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