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

@a = external global i32

define void @b() {
; CHECK-LABEL: @b(
; CHECK-NEXT:    br i1 false, label [[C:%.*]], label [[WHILE_D:%.*]]
; CHECK:       while.d:
; CHECK-NEXT:    br label [[F:%.*]]
; CHECK:       f:
; CHECK-NEXT:    br i1 undef, label [[IF_E:%.*]], label [[C]]
; CHECK:       c:
; CHECK-NEXT:    br i1 undef, label [[IF_G:%.*]], label [[IF_E]]
; CHECK:       if.g:
; CHECK-NEXT:    store i32 undef, i32* @a
; CHECK-NEXT:    br label [[WHILE_D]]
; CHECK:       if.e:
; CHECK-NEXT:    br label [[F]]
;
  br i1 false, label %c, label %while.d

while.d:                                          ; preds = %if.g, %0
  br label %f

f:                                                ; preds = %if.e, %while.d
  br i1 undef, label %if.e, label %c

c:                                                ; preds = %f, %0
  br i1 undef, label %if.g, label %if.e

if.g:                                             ; preds = %c
  store i32 undef, i32* @a
  br label %while.d

if.e:                                             ; preds = %c, %f
  br label %f
}