llvm/llvm/test/Transforms/SimplifyCFG/pr55765.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -passes=simplifycfg < %s | FileCheck %s

; This used to infinitely thread between loop and loop.latch without reaching a
; fixed point.

declare void @dummy()

define i32 @main(i1 %c1, i1 %c2, i32 %y) {
; CHECK-LABEL: @main(
; CHECK-NEXT:    br i1 [[C1:%.*]], label [[EXIT:%.*]], label [[LOOP_PRE_PREHEADER:%.*]]
; CHECK:       loop.pre.preheader:
; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[Y:%.*]], -1
; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP_PREHEADER:%.*]], label [[EXIT]]
; CHECK:       loop.preheader:
; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i32 [[Y]], 0
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    br i1 [[C1]], label [[LOOP2:%.*]], label [[LOOP_LATCH:%.*]]
; CHECK:       loop.latch:
; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP]], label [[EXIT]]
; CHECK:       loop2:
; CHECK-NEXT:    br i1 [[CMP2]], label [[JOIN:%.*]], label [[IF:%.*]]
; CHECK:       if:
; CHECK-NEXT:    call void @dummy()
; CHECK-NEXT:    br label [[JOIN]]
; CHECK:       join:
; CHECK-NEXT:    br i1 [[C2:%.*]], label [[LOOP2]], label [[LOOP_LATCH]]
; CHECK:       exit:
; CHECK-NEXT:    ret i32 0
;
  br i1 %c1, label %exit, label %loop.pre.preheader

loop.pre.preheader:
  %cmp = icmp sgt i32 %y, -1
  br i1 %cmp, label %loop.preheader, label %exit

loop.preheader:
  %cmp2 = icmp eq i32 %y, 0
  br label %loop

loop:
  br i1 %c1, label %loop2, label %loop.latch

loop.latch:
  br i1 %cmp, label %loop, label %exit

loop2:
  br i1 %cmp2, label %join, label %if

if:
  call void @dummy()
  br label %join

join:
  br i1 %c2, label %loop2, label %loop.latch

exit:
  ret i32 0

; uselistorder directives
  uselistorder label %loop2, { 1, 0 }
}