llvm-6502/test/Transforms/LoopUnswitch/infinite-loop.ll

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; RUN: opt -loop-unswitch -disable-output -stats -info-output-file - < %s | FileCheck --check-prefix=STATS %s
; RUN: opt -loop-unswitch -simplifycfg -S < %s | FileCheck %s
; PR5373
; Loop unswitching shouldn't trivially unswitch the true case of condition %a
; in the code here because it leads to an infinite loop. While this doesn't
; contain any instructions with side effects, it's still a kind of side effect.
; It can trivially unswitch on the false cas of condition %a though.
; STATS: 2 loop-unswitch - Number of branches unswitched
; STATS: 1 loop-unswitch - Number of unswitches that are trivial
; CHECK: @func_16
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %a, label %entry.split, label %abort0.split
; CHECK: entry.split:
; CHECK-NEXT: br i1 %b, label %cond.end.us, label %abort1
; CHECK: cond.end.us:
; CHECK-NEXT: br label %cond.end.us
; CHECK: abort0.split:
; CHECK-NEXT: call void @end0() noreturn nounwind
; CHECK-NEXT: unreachable
; CHECK: abort1:
; CHECK-NEXT: call void @end1() noreturn nounwind
; CHECK-NEXT: unreachable
; CHECK: }
define void @func_16(i1 %a, i1 %b) nounwind {
entry:
br label %for.body
for.body:
br i1 %a, label %cond.end, label %abort0
cond.end:
br i1 %b, label %for.body, label %abort1
abort0:
call void @end0() noreturn nounwind
unreachable
abort1:
call void @end1() noreturn nounwind
unreachable
}
declare void @end0() noreturn
declare void @end1() noreturn