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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -fix-irreducible -structurizecfg -S | FileCheck %s
; Both B1 and B4 are headers of an irreducible cycle. But in the
; structurized version, B1 dominates B4. The program is structurized
; correctly when the irreducible cycle is fixed.
define void @irreducible(i1 %PredEntry, i1 %PredB1, i1 %PredB2, i1 %PredB3, i1 %PredB4)
; CHECK-LABEL: @irreducible(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[PREDB2_INV:%.*]] = xor i1 [[PREDB2:%.*]], true
; CHECK-NEXT: [[PREDB1_INV:%.*]] = xor i1 [[PREDB1:%.*]], true
; CHECK-NEXT: br label [[IRR_GUARD:%.*]]
; CHECK: Flow:
; CHECK-NEXT: [[TMP0:%.*]] = phi i1 [ [[PREDB4:%.*]], [[B4:%.*]] ], [ false, [[IRR_GUARD]] ]
; CHECK-NEXT: [[TMP1:%.*]] = phi i1 [ false, [[B4]] ], [ true, [[IRR_GUARD]] ]
; CHECK-NEXT: br i1 [[TMP1]], label [[B1:%.*]], label [[FLOW1:%.*]]
; CHECK: B1:
; CHECK-NEXT: br label [[FLOW1]]
; CHECK: Flow1:
; CHECK-NEXT: [[TMP2:%.*]] = phi i1 [ [[PREDB1_INV]], [[B1]] ], [ [[TMP0]], [[FLOW:%.*]] ]
; CHECK-NEXT: br i1 [[TMP2]], label [[B2:%.*]], label [[FLOW2:%.*]]
; CHECK: B2:
; CHECK-NEXT: br i1 [[PREDB2_INV]], label [[B3:%.*]], label [[FLOW3:%.*]]
; CHECK: Flow2:
; CHECK-NEXT: [[TMP3:%.*]] = phi i1 [ [[TMP5:%.*]], [[FLOW3]] ], [ undef, [[FLOW1]] ]
; CHECK-NEXT: [[TMP4:%.*]] = phi i1 [ [[TMP6:%.*]], [[FLOW3]] ], [ true, [[FLOW1]] ]
; CHECK-NEXT: br i1 [[TMP4]], label [[EXIT:%.*]], label [[IRR_GUARD]]
; CHECK: B3:
; CHECK-NEXT: br label [[FLOW3]]
; CHECK: B4:
; CHECK-NEXT: br label [[FLOW]]
; CHECK: Flow3:
; CHECK-NEXT: [[TMP5]] = phi i1 [ [[PREDB3:%.*]], [[B3]] ], [ undef, [[B2]] ]
; CHECK-NEXT: [[TMP6]] = phi i1 [ false, [[B3]] ], [ true, [[B2]] ]
; CHECK-NEXT: br label [[FLOW2]]
; CHECK: exit:
; CHECK-NEXT: ret void
; CHECK: irr.guard:
; CHECK-NEXT: [[GUARD_B1:%.*]] = phi i1 [ [[PREDENTRY:%.*]], [[ENTRY:%.*]] ], [ [[TMP3]], [[FLOW2]] ]
; CHECK-NEXT: [[GUARD_B1_INV:%.*]] = xor i1 [[GUARD_B1]], true
; CHECK-NEXT: br i1 [[GUARD_B1_INV]], label [[B4]], label [[FLOW]]
;
{
entry:
br i1 %PredEntry, label %B1, label %B4
B1:
br i1 %PredB1, label %exit, label %B2
B2:
br i1 %PredB2, label %exit, label %B3
B3:
br i1 %PredB3, label %B1, label %B4
B4:
br i1 %PredB4, label %B2, label %exit
exit:
ret void
}
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