llvm/test/Transforms/StructurizeCFG/loop-prefix-backedge-condition.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes=structurizecfg %s -o - | FileCheck %s

; The backedge targets a flow block in front of h. It must loop back, not exit.

define i32 @f(i32 %s) {
; CHECK-LABEL: define i32 @f(
; CHECK-SAME: i32 [[S:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*]]:
; CHECK-NEXT:    [[C0:%.*]] = trunc i32 [[S]] to i1
; CHECK-NEXT:    [[C0_INV:%.*]] = xor i1 [[C0]], true
; CHECK-NEXT:    br label %[[FLOW:.*]]
; CHECK:       [[FLOW]]:
; CHECK-NEXT:    [[TMP0:%.*]] = phi i32 [ [[TMP4:%.*]], %[[FLOW1:.*]] ], [ poison, %[[ENTRY]] ]
; CHECK-NEXT:    [[TMP1:%.*]] = phi i32 [ [[TMP5:%.*]], %[[FLOW1]] ], [ 0, %[[ENTRY]] ]
; CHECK-NEXT:    [[TMP2:%.*]] = phi i1 [ [[TMP7:%.*]], %[[FLOW1]] ], [ [[C0_INV]], %[[ENTRY]] ]
; CHECK-NEXT:    [[TMP3:%.*]] = phi i1 [ true, %[[FLOW1]] ], [ [[C0]], %[[ENTRY]] ]
; CHECK-NEXT:    br i1 [[TMP3]], label %[[H:.*]], label %[[FLOW1]]
; CHECK:       [[H]]:
; CHECK-NEXT:    [[I1:%.*]] = add i32 [[TMP1]], 1
; CHECK-NEXT:    [[C1:%.*]] = icmp ult i32 [[I1]], [[S]]
; CHECK-NEXT:    br i1 [[C1]], label %[[L:.*]], label %[[FLOW2:.*]]
; CHECK:       [[FLOW1]]:
; CHECK-NEXT:    [[TMP4]] = phi i32 [ [[I1]], %[[FLOW2]] ], [ [[TMP0]], %[[FLOW]] ]
; CHECK-NEXT:    [[TMP5]] = phi i32 [ [[I1]], %[[FLOW2]] ], [ [[TMP1]], %[[FLOW]] ]
; CHECK-NEXT:    [[TMP6:%.*]] = phi i1 [ [[TMP8:%.*]], %[[FLOW2]] ], [ true, %[[FLOW]] ]
; CHECK-NEXT:    [[TMP7]] = phi i1 [ [[TMP9:%.*]], %[[FLOW2]] ], [ [[TMP2]], %[[FLOW]] ]
; CHECK-NEXT:    br i1 [[TMP6]], label %[[FLOW3:.*]], label %[[FLOW]]
; CHECK:       [[L]]:
; CHECK-NEXT:    [[C2:%.*]] = icmp uge i32 [[I1]], 3
; CHECK-NEXT:    br label %[[FLOW2]]
; CHECK:       [[FLOW2]]:
; CHECK-NEXT:    [[TMP8]] = phi i1 [ [[C2]], %[[L]] ], [ true, %[[H]] ]
; CHECK-NEXT:    [[TMP9]] = phi i1 [ [[C2]], %[[L]] ], [ [[TMP2]], %[[H]] ]
; CHECK-NEXT:    br label %[[FLOW1]]
; CHECK:       [[FLOW3]]:
; CHECK-NEXT:    br i1 [[TMP7]], label %[[OTHER:.*]], label %[[RET:.*]]
; CHECK:       [[OTHER]]:
; CHECK-NEXT:    br label %[[RET]]
; CHECK:       [[RET]]:
; CHECK-NEXT:    [[R:%.*]] = phi i32 [ [[TMP4]], %[[FLOW3]] ], [ 0, %[[OTHER]] ]
; CHECK-NEXT:    ret i32 [[R]]
;
entry:
  %c0 = trunc i32 %s to i1
  br i1 %c0, label %h, label %other
h:
  %i = phi i32 [ 0, %entry ], [ %i1, %l ]
  %i1 = add i32 %i, 1
  %c1 = icmp ult i32 %i1, %s
  br i1 %c1, label %l, label %ret
l:
  %c2 = icmp ult i32 %i1, 3
  br i1 %c2, label %h, label %other
other:
  br label %ret
ret:
  %r = phi i32 [ %i1, %h ], [ 0, %other ]
  ret i32 %r
}