llvm/test/Transforms/LoopUnroll/runtime-loop-multiexit-dom-verify.ll

   1 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
   2 ; RUN: opt < %s -passes=loop-unroll -unroll-runtime=true -unroll-runtime-epilog=false -unroll-runtime-multi-exit=true -unroll-count=4  -verify-dom-info -S | FileCheck %s
   3
   4 ; REQUIRES: asserts
   5 ; The tests below are for verifying dom tree after runtime unrolling
   6 ; with multiple exit/exiting blocks.
   7
   8 ; We explicitly set the unroll count so that expensiveTripCount computation is allowed.
   9
  10 declare i1 @unknown(i32) readonly nounwind willreturn
  11
  12 ; mergedexit block has edges from loop exit blocks.
  13 define i64 @test1() {
  14 ; CHECK-LABEL: @test1(
  15 ; CHECK-NEXT:  entry:
  16 ; CHECK-NEXT:    br label [[PREHEADER:%.*]]
  17 ; CHECK:       preheader:
  18 ; CHECK-NEXT:    [[TRIP:%.*]] = zext i32 undef to i64
  19 ; CHECK-NEXT:    br label [[HEADER:%.*]]
  20 ; CHECK:       header:
  21 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 2, [[PREHEADER]] ], [ [[ADD_IV_3:%.*]], [[LATCH_3:%.*]] ]
  22 ; CHECK-NEXT:    [[ADD_IV:%.*]] = add nuw nsw i64 [[IV]], 2
  23 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[ADD_IV]], [[TRIP]]
  24 ; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH:%.*]], label [[HEADEREXIT:%.*]]
  25 ; CHECK:       latch:
  26 ; CHECK-NEXT:    [[SHFT:%.*]] = ashr i64 [[ADD_IV]], 1
  27 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[SHFT]], [[TRIP]]
  28 ; CHECK-NEXT:    br i1 [[CMP2]], label [[HEADER_1:%.*]], label [[LATCHEXIT:%.*]]
  29 ; CHECK:       header.1:
  30 ; CHECK-NEXT:    [[ADD_IV_1:%.*]] = add nuw nsw i64 [[IV]], 4
  31 ; CHECK-NEXT:    [[CMP1_1:%.*]] = icmp ult i64 [[ADD_IV_1]], [[TRIP]]
  32 ; CHECK-NEXT:    br i1 [[CMP1_1]], label [[LATCH_1:%.*]], label [[HEADEREXIT]]
  33 ; CHECK:       latch.1:
  34 ; CHECK-NEXT:    [[SHFT_1:%.*]] = ashr i64 [[ADD_IV_1]], 1
  35 ; CHECK-NEXT:    [[CMP2_1:%.*]] = icmp ult i64 [[SHFT_1]], [[TRIP]]
  36 ; CHECK-NEXT:    br i1 [[CMP2_1]], label [[HEADER_2:%.*]], label [[LATCHEXIT]]
  37 ; CHECK:       header.2:
  38 ; CHECK-NEXT:    [[ADD_IV_2:%.*]] = add nuw nsw i64 [[IV]], 6
  39 ; CHECK-NEXT:    [[CMP1_2:%.*]] = icmp ult i64 [[ADD_IV_2]], [[TRIP]]
  40 ; CHECK-NEXT:    br i1 [[CMP1_2]], label [[LATCH_2:%.*]], label [[HEADEREXIT]]
  41 ; CHECK:       latch.2:
  42 ; CHECK-NEXT:    [[SHFT_2:%.*]] = ashr i64 [[ADD_IV_2]], 1
  43 ; CHECK-NEXT:    [[CMP2_2:%.*]] = icmp ult i64 [[SHFT_2]], [[TRIP]]
  44 ; CHECK-NEXT:    br i1 [[CMP2_2]], label [[HEADER_3:%.*]], label [[LATCHEXIT]]
  45 ; CHECK:       header.3:
  46 ; CHECK-NEXT:    [[ADD_IV_3]] = add nuw nsw i64 [[IV]], 8
  47 ; CHECK-NEXT:    [[CMP1_3:%.*]] = icmp ult i64 [[ADD_IV_3]], [[TRIP]]
  48 ; CHECK-NEXT:    br i1 [[CMP1_3]], label [[LATCH_3]], label [[HEADEREXIT]]
  49 ; CHECK:       latch.3:
  50 ; CHECK-NEXT:    [[SHFT_3:%.*]] = ashr i64 [[ADD_IV_3]], 1
  51 ; CHECK-NEXT:    [[CMP2_3:%.*]] = icmp ult i64 [[SHFT_3]], [[TRIP]]
  52 ; CHECK-NEXT:    br i1 [[CMP2_3]], label [[HEADER]], label [[LATCHEXIT]], !llvm.loop [[LOOP0:![0-9]+]]
  53 ; CHECK:       headerexit:
  54 ; CHECK-NEXT:    [[ADDPHI:%.*]] = phi i64 [ [[ADD_IV]], [[HEADER]] ], [ [[ADD_IV_1]], [[HEADER_1]] ], [ [[ADD_IV_2]], [[HEADER_2]] ], [ [[ADD_IV_3]], [[HEADER_3]] ]
  55 ; CHECK-NEXT:    br label [[MERGEDEXIT:%.*]]
  56 ; CHECK:       latchexit:
  57 ; CHECK-NEXT:    [[SHFTPHI:%.*]] = phi i64 [ [[SHFT]], [[LATCH]] ], [ [[SHFT_1]], [[LATCH_1]] ], [ [[SHFT_2]], [[LATCH_2]] ], [ [[SHFT_3]], [[LATCH_3]] ]
  58 ; CHECK-NEXT:    br label [[MERGEDEXIT]]
  59 ; CHECK:       mergedexit:
  60 ; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[ADDPHI]], [[HEADEREXIT]] ], [ [[SHFTPHI]], [[LATCHEXIT]] ]
  61 ; CHECK-NEXT:    ret i64 [[RETVAL]]
  62 ;
  63 entry:
  64   br label %preheader
  65
  66 preheader:                                              ; preds = %bb
  67   %trip = zext i32 undef to i64
  68   br label %header
  69
  70 header:                                              ; preds = %latch, %preheader
  71   %iv = phi i64 [ 2, %preheader ], [ %add.iv, %latch ]
  72   %add.iv = add nuw nsw i64 %iv, 2
  73   %cmp1 = icmp ult i64 %add.iv, %trip
  74   br i1 %cmp1, label %latch, label %headerexit
  75
  76 latch:                                             ; preds = %header
  77   %shft = ashr i64 %add.iv, 1
  78   %cmp2 = icmp ult i64 %shft, %trip
  79   br i1 %cmp2, label %header, label %latchexit
  80
  81 headerexit:                                              ; preds = %header
  82   %addphi = phi i64 [ %add.iv, %header ]
  83   br label %mergedexit
  84
  85 latchexit:                                              ; preds = %latch
  86   %shftphi = phi i64 [ %shft, %latch ]
  87   br label %mergedexit
  88
  89 mergedexit:                                              ; preds = %latchexit, %headerexit
  90   %retval = phi i64 [ %addphi, %headerexit ], [ %shftphi, %latchexit ]
  91   ret i64 %retval
  92 }
  93
  94 ; mergedexit has edges from loop exit blocks and a block outside the loop.
  95 define  void @test2(i1 %cond, i32 %n) {
  96 ; CHECK-LABEL: @test2(
  97 ; CHECK-NEXT:  entry:
  98 ; CHECK-NEXT:    br i1 [[COND:%.*]], label [[PREHEADER:%.*]], label [[MERGEDEXIT:%.*]]
  99 ; CHECK:       preheader:
 100 ; CHECK-NEXT:    [[TRIP:%.*]] = zext i32 [[N:%.*]] to i64
 101 ; CHECK-NEXT:    br label [[HEADER:%.*]]
 102 ; CHECK:       header:
 103 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 2, [[PREHEADER]] ], [ [[ADD_IV_3:%.*]], [[LATCH_3:%.*]] ]
 104 ; CHECK-NEXT:    [[ADD_IV:%.*]] = add nuw nsw i64 [[IV]], 2
 105 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[ADD_IV]], [[TRIP]]
 106 ; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH:%.*]], label [[HEADEREXIT:%.*]]
 107 ; CHECK:       latch:
 108 ; CHECK-NEXT:    [[SHFT:%.*]] = ashr i64 [[ADD_IV]], 1
 109 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[SHFT]], [[TRIP]]
 110 ; CHECK-NEXT:    br i1 [[CMP2]], label [[HEADER_1:%.*]], label [[LATCHEXIT:%.*]]
 111 ; CHECK:       header.1:
 112 ; CHECK-NEXT:    [[ADD_IV_1:%.*]] = add nuw nsw i64 [[IV]], 4
 113 ; CHECK-NEXT:    [[CMP1_1:%.*]] = icmp ult i64 [[ADD_IV_1]], [[TRIP]]
 114 ; CHECK-NEXT:    br i1 [[CMP1_1]], label [[LATCH_1:%.*]], label [[HEADEREXIT]]
 115 ; CHECK:       latch.1:
 116 ; CHECK-NEXT:    [[SHFT_1:%.*]] = ashr i64 [[ADD_IV_1]], 1
 117 ; CHECK-NEXT:    [[CMP2_1:%.*]] = icmp ult i64 [[SHFT_1]], [[TRIP]]
 118 ; CHECK-NEXT:    br i1 [[CMP2_1]], label [[HEADER_2:%.*]], label [[LATCHEXIT]]
 119 ; CHECK:       header.2:
 120 ; CHECK-NEXT:    [[ADD_IV_2:%.*]] = add nuw nsw i64 [[IV]], 6
 121 ; CHECK-NEXT:    [[CMP1_2:%.*]] = icmp ult i64 [[ADD_IV_2]], [[TRIP]]
 122 ; CHECK-NEXT:    br i1 [[CMP1_2]], label [[LATCH_2:%.*]], label [[HEADEREXIT]]
 123 ; CHECK:       latch.2:
 124 ; CHECK-NEXT:    [[SHFT_2:%.*]] = ashr i64 [[ADD_IV_2]], 1
 125 ; CHECK-NEXT:    [[CMP2_2:%.*]] = icmp ult i64 [[SHFT_2]], [[TRIP]]
 126 ; CHECK-NEXT:    br i1 [[CMP2_2]], label [[HEADER_3:%.*]], label [[LATCHEXIT]]
 127 ; CHECK:       header.3:
 128 ; CHECK-NEXT:    [[ADD_IV_3]] = add nuw nsw i64 [[IV]], 8
 129 ; CHECK-NEXT:    [[CMP1_3:%.*]] = icmp ult i64 [[ADD_IV_3]], [[TRIP]]
 130 ; CHECK-NEXT:    br i1 [[CMP1_3]], label [[LATCH_3]], label [[HEADEREXIT]]
 131 ; CHECK:       latch.3:
 132 ; CHECK-NEXT:    [[SHFT_3:%.*]] = ashr i64 [[ADD_IV_3]], 1
 133 ; CHECK-NEXT:    [[CMP2_3:%.*]] = icmp ult i64 [[SHFT_3]], [[TRIP]]
 134 ; CHECK-NEXT:    br i1 [[CMP2_3]], label [[HEADER]], label [[LATCHEXIT]], !llvm.loop [[LOOP2:![0-9]+]]
 135 ; CHECK:       headerexit:
 136 ; CHECK-NEXT:    br label [[MERGEDEXIT]]
 137 ; CHECK:       latchexit:
 138 ; CHECK-NEXT:    br label [[MERGEDEXIT]]
 139 ; CHECK:       mergedexit:
 140 ; CHECK-NEXT:    ret void
 141 ;
 142 entry:
 143   br i1 %cond, label %preheader, label %mergedexit
 144
 145 preheader:                                              ; preds = %entry
 146   %trip = zext i32 %n to i64
 147   br label %header
 148
 149 header:                                              ; preds = %latch, %preheader
 150   %iv = phi i64 [ 2, %preheader ], [ %add.iv, %latch ]
 151   %add.iv = add nuw nsw i64 %iv, 2
 152   %cmp1 = icmp ult i64 %add.iv, %trip
 153   br i1 %cmp1, label %latch, label %headerexit
 154
 155 latch:                                             ; preds = %header
 156   %shft = ashr i64 %add.iv, 1
 157   %cmp2 = icmp ult i64 %shft, %trip
 158   br i1 %cmp2, label %header, label %latchexit
 159
 160 headerexit:                                              ; preds = %header
 161   br label %mergedexit
 162
 163 latchexit:                                              ; preds = %latch
 164   br label %mergedexit
 165
 166 mergedexit:                                              ; preds = %latchexit, %headerexit, %entry
 167   ret void
 168 }
 169
 170
 171 ; exitsucc is from loop exit block only.
 172 define i64 @test3(i32 %n) {
 173 ; CHECK-LABEL: @test3(
 174 ; CHECK-NEXT:  entry:
 175 ; CHECK-NEXT:    br label [[PREHEADER:%.*]]
 176 ; CHECK:       preheader:
 177 ; CHECK-NEXT:    [[TRIP:%.*]] = zext i32 [[N:%.*]] to i64
 178 ; CHECK-NEXT:    br label [[HEADER:%.*]]
 179 ; CHECK:       header:
 180 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ 2, [[PREHEADER]] ], [ [[ADD_IV_3:%.*]], [[LATCH_3:%.*]] ]
 181 ; CHECK-NEXT:    [[ADD_IV:%.*]] = add nuw nsw i64 [[IV]], 2
 182 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i64 [[ADD_IV]], [[TRIP]]
 183 ; CHECK-NEXT:    br i1 [[CMP1]], label [[LATCH:%.*]], label [[HEADEREXIT:%.*]]
 184 ; CHECK:       latch:
 185 ; CHECK-NEXT:    [[SHFT:%.*]] = ashr i64 [[ADD_IV]], 1
 186 ; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i64 [[SHFT]], [[TRIP]]
 187 ; CHECK-NEXT:    br i1 [[CMP2]], label [[HEADER_1:%.*]], label [[LATCHEXIT:%.*]]
 188 ; CHECK:       header.1:
 189 ; CHECK-NEXT:    [[ADD_IV_1:%.*]] = add nuw nsw i64 [[IV]], 4
 190 ; CHECK-NEXT:    [[CMP1_1:%.*]] = icmp ult i64 [[ADD_IV_1]], [[TRIP]]
 191 ; CHECK-NEXT:    br i1 [[CMP1_1]], label [[LATCH_1:%.*]], label [[HEADEREXIT]]
 192 ; CHECK:       latch.1:
 193 ; CHECK-NEXT:    [[SHFT_1:%.*]] = ashr i64 [[ADD_IV_1]], 1
 194 ; CHECK-NEXT:    [[CMP2_1:%.*]] = icmp ult i64 [[SHFT_1]], [[TRIP]]
 195 ; CHECK-NEXT:    br i1 [[CMP2_1]], label [[HEADER_2:%.*]], label [[LATCHEXIT]]
 196 ; CHECK:       header.2:
 197 ; CHECK-NEXT:    [[ADD_IV_2:%.*]] = add nuw nsw i64 [[IV]], 6
 198 ; CHECK-NEXT:    [[CMP1_2:%.*]] = icmp ult i64 [[ADD_IV_2]], [[TRIP]]
 199 ; CHECK-NEXT:    br i1 [[CMP1_2]], label [[LATCH_2:%.*]], label [[HEADEREXIT]]
 200 ; CHECK:       latch.2:
 201 ; CHECK-NEXT:    [[SHFT_2:%.*]] = ashr i64 [[ADD_IV_2]], 1
 202 ; CHECK-NEXT:    [[CMP2_2:%.*]] = icmp ult i64 [[SHFT_2]], [[TRIP]]
 203 ; CHECK-NEXT:    br i1 [[CMP2_2]], label [[HEADER_3:%.*]], label [[LATCHEXIT]]
 204 ; CHECK:       header.3:
 205 ; CHECK-NEXT:    [[ADD_IV_3]] = add nuw nsw i64 [[IV]], 8
 206 ; CHECK-NEXT:    [[CMP1_3:%.*]] = icmp ult i64 [[ADD_IV_3]], [[TRIP]]
 207 ; CHECK-NEXT:    br i1 [[CMP1_3]], label [[LATCH_3]], label [[HEADEREXIT]]
 208 ; CHECK:       latch.3:
 209 ; CHECK-NEXT:    [[SHFT_3:%.*]] = ashr i64 [[ADD_IV_3]], 1
 210 ; CHECK-NEXT:    [[CMP2_3:%.*]] = icmp ult i64 [[SHFT_3]], [[TRIP]]
 211 ; CHECK-NEXT:    br i1 [[CMP2_3]], label [[HEADER]], label [[LATCHEXIT]], !llvm.loop [[LOOP3:![0-9]+]]
 212 ; CHECK:       headerexit:
 213 ; CHECK-NEXT:    br label [[EXITSUCC:%.*]]
 214 ; CHECK:       latchexit:
 215 ; CHECK-NEXT:    [[SHFTPHI:%.*]] = phi i64 [ [[SHFT]], [[LATCH]] ], [ [[SHFT_1]], [[LATCH_1]] ], [ [[SHFT_2]], [[LATCH_2]] ], [ [[SHFT_3]], [[LATCH_3]] ]
 216 ; CHECK-NEXT:    ret i64 [[SHFTPHI]]
 217 ; CHECK:       exitsucc:
 218 ; CHECK-NEXT:    ret i64 96
 219 ;
 220 entry:
 221   br label %preheader
 222
 223 preheader:                                              ; preds = %bb
 224   %trip = zext i32 %n to i64
 225   br label %header
 226
 227 header:                                              ; preds = %latch, %preheader
 228   %iv = phi i64 [ 2, %preheader ], [ %add.iv, %latch ]
 229   %add.iv = add nuw nsw i64 %iv, 2
 230   %cmp1 = icmp ult i64 %add.iv, %trip
 231   br i1 %cmp1, label %latch, label %headerexit
 232
 233 latch:                                             ; preds = %header
 234   %shft = ashr i64 %add.iv, 1
 235   %cmp2 = icmp ult i64 %shft, %trip
 236   br i1 %cmp2, label %header, label %latchexit
 237
 238 headerexit:                                              ; preds = %header
 239   br label %exitsucc
 240
 241 latchexit:                                              ; preds = %latch
 242   %shftphi = phi i64 [ %shft, %latch ]
 243   ret i64 %shftphi
 244
 245 exitsucc:                                              ; preds = %headerexit
 246   ret i64 96
 247 }
 248
 249 ; exit block (%default) has an exiting block and another exit block as predecessors.
 250 define void @test4(i16 %c3) {
 251 ; CHECK-LABEL: @test4(
 252 ; CHECK-NEXT:  preheader:
 253 ; CHECK-NEXT:    [[C1:%.*]] = zext i32 undef to i64
 254 ; CHECK-NEXT:    [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[C1]], i64 1)
 255 ; CHECK-NEXT:    [[TMP0:%.*]] = freeze i64 [[UMAX]]
 256 ; CHECK-NEXT:    [[TMP1:%.*]] = add i64 [[TMP0]], -1
 257 ; CHECK-NEXT:    [[XTRAITER:%.*]] = and i64 [[TMP0]], 3
 258 ; CHECK-NEXT:    [[LCMP_MOD:%.*]] = icmp ne i64 [[XTRAITER]], 0
 259 ; CHECK-NEXT:    br i1 [[LCMP_MOD]], label [[HEADER_PROL_PREHEADER:%.*]], label [[HEADER_PROL_LOOPEXIT:%.*]]
 260 ; CHECK:       header.prol.preheader:
 261 ; CHECK-NEXT:    br label [[HEADER_PROL:%.*]]
 262 ; CHECK:       header.prol:
 263 ; CHECK-NEXT:    [[INDVARS_IV_PROL:%.*]] = phi i64 [ 0, [[HEADER_PROL_PREHEADER]] ], [ [[INDVARS_IV_NEXT_PROL:%.*]], [[LATCH_PROL:%.*]] ]
 264 ; CHECK-NEXT:    [[PROL_ITER:%.*]] = phi i64 [ 0, [[HEADER_PROL_PREHEADER]] ], [ [[PROL_ITER_NEXT:%.*]], [[LATCH_PROL]] ]
 265 ; CHECK-NEXT:    br label [[EXITING_PROL:%.*]]
 266 ; CHECK:       exiting.prol:
 267 ; CHECK-NEXT:    switch i16 [[C3:%.*]], label [[DEFAULT_LOOPEXIT_LOOPEXIT1:%.*]] [
 268 ; CHECK-NEXT:    i16 45, label [[OTHEREXIT_LOOPEXIT2:%.*]]
 269 ; CHECK-NEXT:    i16 95, label [[LATCH_PROL]]
 270 ; CHECK-NEXT:    ]
 271 ; CHECK:       latch.prol:
 272 ; CHECK-NEXT:    [[INDVARS_IV_NEXT_PROL]] = add nuw nsw i64 [[INDVARS_IV_PROL]], 1
 273 ; CHECK-NEXT:    [[C2_PROL:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT_PROL]], [[C1]]
 274 ; CHECK-NEXT:    [[PROL_ITER_NEXT]] = add i64 [[PROL_ITER]], 1
 275 ; CHECK-NEXT:    [[PROL_ITER_CMP:%.*]] = icmp ne i64 [[PROL_ITER_NEXT]], [[XTRAITER]]
 276 ; CHECK-NEXT:    br i1 [[PROL_ITER_CMP]], label [[HEADER_PROL]], label [[HEADER_PROL_LOOPEXIT_UNR_LCSSA:%.*]], !llvm.loop [[LOOP4:![0-9]+]]
 277 ; CHECK:       header.prol.loopexit.unr-lcssa:
 278 ; CHECK-NEXT:    [[INDVARS_IV_UNR_PH:%.*]] = phi i64 [ [[INDVARS_IV_NEXT_PROL]], [[LATCH_PROL]] ]
 279 ; CHECK-NEXT:    br label [[HEADER_PROL_LOOPEXIT]]
 280 ; CHECK:       header.prol.loopexit:
 281 ; CHECK-NEXT:    [[INDVARS_IV_UNR:%.*]] = phi i64 [ 0, [[PREHEADER:%.*]] ], [ [[INDVARS_IV_UNR_PH]], [[HEADER_PROL_LOOPEXIT_UNR_LCSSA]] ]
 282 ; CHECK-NEXT:    [[TMP2:%.*]] = icmp ult i64 [[TMP1]], 3
 283 ; CHECK-NEXT:    br i1 [[TMP2]], label [[LATCHEXIT:%.*]], label [[PREHEADER_NEW:%.*]]
 284 ; CHECK:       preheader.new:
 285 ; CHECK-NEXT:    br label [[HEADER:%.*]]
 286 ; CHECK:       header:
 287 ; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_UNR]], [[PREHEADER_NEW]] ], [ [[INDVARS_IV_NEXT_3:%.*]], [[LATCH_3:%.*]] ]
 288 ; CHECK-NEXT:    br label [[EXITING:%.*]]
 289 ; CHECK:       exiting:
 290 ; CHECK-NEXT:    switch i16 [[C3]], label [[DEFAULT_LOOPEXIT_LOOPEXIT:%.*]] [
 291 ; CHECK-NEXT:    i16 45, label [[OTHEREXIT_LOOPEXIT:%.*]]
 292 ; CHECK-NEXT:    i16 95, label [[LATCH:%.*]]
 293 ; CHECK-NEXT:    ]
 294 ; CHECK:       latch:
 295 ; CHECK-NEXT:    br label [[EXITING_1:%.*]]
 296 ; CHECK:       exiting.1:
 297 ; CHECK-NEXT:    switch i16 [[C3]], label [[DEFAULT_LOOPEXIT_LOOPEXIT]] [
 298 ; CHECK-NEXT:    i16 45, label [[OTHEREXIT_LOOPEXIT]]
 299 ; CHECK-NEXT:    i16 95, label [[LATCH_1:%.*]]
 300 ; CHECK-NEXT:    ]
 301 ; CHECK:       latch.1:
 302 ; CHECK-NEXT:    br label [[EXITING_2:%.*]]
 303 ; CHECK:       exiting.2:
 304 ; CHECK-NEXT:    switch i16 [[C3]], label [[DEFAULT_LOOPEXIT_LOOPEXIT]] [
 305 ; CHECK-NEXT:    i16 45, label [[OTHEREXIT_LOOPEXIT]]
 306 ; CHECK-NEXT:    i16 95, label [[LATCH_2:%.*]]
 307 ; CHECK-NEXT:    ]
 308 ; CHECK:       latch.2:
 309 ; CHECK-NEXT:    br label [[EXITING_3:%.*]]
 310 ; CHECK:       exiting.3:
 311 ; CHECK-NEXT:    switch i16 [[C3]], label [[DEFAULT_LOOPEXIT_LOOPEXIT]] [
 312 ; CHECK-NEXT:    i16 45, label [[OTHEREXIT_LOOPEXIT]]
 313 ; CHECK-NEXT:    i16 95, label [[LATCH_3]]
 314 ; CHECK-NEXT:    ]
 315 ; CHECK:       latch.3:
 316 ; CHECK-NEXT:    [[INDVARS_IV_NEXT_3]] = add nuw nsw i64 [[INDVARS_IV]], 4
 317 ; CHECK-NEXT:    [[C2_3:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT_3]], [[C1]]
 318 ; CHECK-NEXT:    br i1 [[C2_3]], label [[HEADER]], label [[LATCHEXIT_UNR_LCSSA:%.*]], !llvm.loop [[LOOP5:![0-9]+]]
 319 ; CHECK:       latchexit.unr-lcssa:
 320 ; CHECK-NEXT:    br label [[LATCHEXIT]]
 321 ; CHECK:       latchexit:
 322 ; CHECK-NEXT:    ret void
 323 ; CHECK:       default.loopexit.loopexit:
 324 ; CHECK-NEXT:    br label [[DEFAULT_LOOPEXIT:%.*]]
 325 ; CHECK:       default.loopexit.loopexit1:
 326 ; CHECK-NEXT:    br label [[DEFAULT_LOOPEXIT]]
 327 ; CHECK:       default.loopexit:
 328 ; CHECK-NEXT:    br label [[DEFAULT:%.*]]
 329 ; CHECK:       default:
 330 ; CHECK-NEXT:    ret void
 331 ; CHECK:       otherexit.loopexit:
 332 ; CHECK-NEXT:    br label [[OTHEREXIT:%.*]]
 333 ; CHECK:       otherexit.loopexit2:
 334 ; CHECK-NEXT:    br label [[OTHEREXIT]]
 335 ; CHECK:       otherexit:
 336 ; CHECK-NEXT:    br label [[DEFAULT]]
 337 ;
 338 preheader:
 339   %c1 = zext i32 undef to i64
 340   br label %header
 341
 342 header:                                       ; preds = %latch, %preheader
 343   %indvars.iv = phi i64 [ 0, %preheader ], [ %indvars.iv.next, %latch ]
 344   br label %exiting
 345
 346 exiting:                                           ; preds = %header
 347   switch i16 %c3, label %default [
 348   i16 45, label %otherexit
 349   i16 95, label %latch
 350   ]
 351
 352 latch:                                          ; preds = %exiting
 353   %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
 354   %c2 = icmp ult i64 %indvars.iv.next, %c1
 355   br i1 %c2, label %header, label %latchexit
 356
 357 latchexit:                                          ; preds = %latch
 358   ret void
 359
 360 default:                                          ; preds = %otherexit, %exiting
 361   ret void
 362
 363 otherexit:                                           ; preds = %exiting
 364   br label %default
 365 }
 366
 367 ; exit block (%exitB) has an exiting block and another exit block as predecessors.
 368 ; exiting block comes from inner loop.
 369 define void @test5() {
 370 ; CHECK-LABEL: @test5(
 371 ; CHECK-NEXT:  bb:
 372 ; CHECK-NEXT:    [[TMP:%.*]] = icmp sgt i32 undef, 79
 373 ; CHECK-NEXT:    br i1 [[TMP]], label [[OUTERLATCHEXIT:%.*]], label [[BB1:%.*]]
 374 ; CHECK:       bb1:
 375 ; CHECK-NEXT:    [[TMP0:%.*]] = freeze i32 undef
 376 ; CHECK-NEXT:    [[TMP1:%.*]] = add i32 [[TMP0]], -1
 377 ; CHECK-NEXT:    [[XTRAITER:%.*]] = and i32 [[TMP0]], 3
 378 ; CHECK-NEXT:    [[LCMP_MOD:%.*]] = icmp ne i32 [[XTRAITER]], 0
 379 ; CHECK-NEXT:    br i1 [[LCMP_MOD]], label [[OUTERH_PROL_PREHEADER:%.*]], label [[OUTERH_PROL_LOOPEXIT:%.*]]
 380 ; CHECK:       outerH.prol.preheader:
 381 ; CHECK-NEXT:    br label [[OUTERH_PROL:%.*]]
 382 ; CHECK:       outerH.prol:
 383 ; CHECK-NEXT:    [[TMP4_PROL:%.*]] = phi i32 [ [[TMP6_PROL:%.*]], [[OUTERLATCH_PROL:%.*]] ], [ undef, [[OUTERH_PROL_PREHEADER]] ]
 384 ; CHECK-NEXT:    [[PROL_ITER:%.*]] = phi i32 [ 0, [[OUTERH_PROL_PREHEADER]] ], [ [[PROL_ITER_NEXT:%.*]], [[OUTERLATCH_PROL]] ]
 385 ; CHECK-NEXT:    br label [[INNERH_PROL:%.*]]
 386 ; CHECK:       innerH.prol:
 387 ; CHECK-NEXT:    [[C1_PROL:%.*]] = call i1 @unknown(i32 0)
 388 ; CHECK-NEXT:    br i1 [[C1_PROL]], label [[INNEREXITING_PROL:%.*]], label [[OTHEREXITB_LOOPEXIT1:%.*]]
 389 ; CHECK:       innerexiting.prol:
 390 ; CHECK-NEXT:    [[C2_PROL:%.*]] = call i1 @unknown(i32 0)
 391 ; CHECK-NEXT:    br i1 [[C2_PROL]], label [[INNERLATCH_PROL:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT2:%.*]]
 392 ; CHECK:       innerLatch.prol:
 393 ; CHECK-NEXT:    br i1 false, label [[INNERH_1_PROL:%.*]], label [[OUTERLATCH_PROL]]
 394 ; CHECK:       innerH.1.prol:
 395 ; CHECK-NEXT:    [[C1_1_PROL:%.*]] = call i1 @unknown(i32 0)
 396 ; CHECK-NEXT:    br i1 [[C1_1_PROL]], label [[INNEREXITING_1_PROL:%.*]], label [[OTHEREXITB_LOOPEXIT1]]
 397 ; CHECK:       innerexiting.1.prol:
 398 ; CHECK-NEXT:    [[C2_1_PROL:%.*]] = call i1 @unknown(i32 0)
 399 ; CHECK-NEXT:    br i1 [[C2_1_PROL]], label [[INNERLATCH_1_PROL:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT2]]
 400 ; CHECK:       innerLatch.1.prol:
 401 ; CHECK-NEXT:    br i1 false, label [[INNERH_2_PROL:%.*]], label [[OUTERLATCH_PROL]]
 402 ; CHECK:       innerH.2.prol:
 403 ; CHECK-NEXT:    [[C1_2_PROL:%.*]] = call i1 @unknown(i32 0)
 404 ; CHECK-NEXT:    br i1 [[C1_2_PROL]], label [[INNEREXITING_2_PROL:%.*]], label [[OTHEREXITB_LOOPEXIT1]]
 405 ; CHECK:       innerexiting.2.prol:
 406 ; CHECK-NEXT:    [[C2_2_PROL:%.*]] = call i1 @unknown(i32 0)
 407 ; CHECK-NEXT:    br i1 [[C2_2_PROL]], label [[INNERLATCH_2_PROL:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT2]]
 408 ; CHECK:       innerLatch.2.prol:
 409 ; CHECK-NEXT:    br i1 false, label [[INNERH_3_PROL:%.*]], label [[OUTERLATCH_PROL]]
 410 ; CHECK:       innerH.3.prol:
 411 ; CHECK-NEXT:    [[C1_3_PROL:%.*]] = call i1 @unknown(i32 0)
 412 ; CHECK-NEXT:    br i1 [[C1_3_PROL]], label [[INNEREXITING_3_PROL:%.*]], label [[OTHEREXITB_LOOPEXIT1]]
 413 ; CHECK:       innerexiting.3.prol:
 414 ; CHECK-NEXT:    [[C2_3_PROL:%.*]] = call i1 @unknown(i32 0)
 415 ; CHECK-NEXT:    br i1 [[C2_3_PROL]], label [[INNERLATCH_3_PROL:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT2]]
 416 ; CHECK:       innerLatch.3.prol:
 417 ; CHECK-NEXT:    br i1 false, label [[INNERH_PROL]], label [[OUTERLATCH_PROL]], !llvm.loop [[LOOP6:![0-9]+]]
 418 ; CHECK:       outerLatch.prol:
 419 ; CHECK-NEXT:    [[TMP6_PROL]] = add i32 [[TMP4_PROL]], 1
 420 ; CHECK-NEXT:    [[TMP7_PROL:%.*]] = icmp sgt i32 [[TMP6_PROL]], 79
 421 ; CHECK-NEXT:    [[PROL_ITER_NEXT]] = add i32 [[PROL_ITER]], 1
 422 ; CHECK-NEXT:    [[PROL_ITER_CMP:%.*]] = icmp ne i32 [[PROL_ITER_NEXT]], [[XTRAITER]]
 423 ; CHECK-NEXT:    br i1 [[PROL_ITER_CMP]], label [[OUTERH_PROL]], label [[OUTERH_PROL_LOOPEXIT_UNR_LCSSA:%.*]], !llvm.loop [[LOOP7:![0-9]+]]
 424 ; CHECK:       outerH.prol.loopexit.unr-lcssa:
 425 ; CHECK-NEXT:    [[TMP4_UNR_PH:%.*]] = phi i32 [ [[TMP6_PROL]], [[OUTERLATCH_PROL]] ]
 426 ; CHECK-NEXT:    br label [[OUTERH_PROL_LOOPEXIT]]
 427 ; CHECK:       outerH.prol.loopexit:
 428 ; CHECK-NEXT:    [[TMP4_UNR:%.*]] = phi i32 [ undef, [[BB1]] ], [ [[TMP4_UNR_PH]], [[OUTERH_PROL_LOOPEXIT_UNR_LCSSA]] ]
 429 ; CHECK-NEXT:    [[TMP2:%.*]] = icmp ult i32 [[TMP1]], 3
 430 ; CHECK-NEXT:    br i1 [[TMP2]], label [[OUTERLATCHEXIT_LOOPEXIT:%.*]], label [[BB1_NEW:%.*]]
 431 ; CHECK:       bb1.new:
 432 ; CHECK-NEXT:    br label [[OUTERH:%.*]]
 433 ; CHECK:       outerH:
 434 ; CHECK-NEXT:    [[TMP4:%.*]] = phi i32 [ [[TMP4_UNR]], [[BB1_NEW]] ], [ [[TMP6_3:%.*]], [[OUTERLATCH_3:%.*]] ]
 435 ; CHECK-NEXT:    br label [[INNERH:%.*]]
 436 ; CHECK:       innerH:
 437 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @unknown(i32 0)
 438 ; CHECK-NEXT:    br i1 [[C1]], label [[INNEREXITING:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT:%.*]]
 439 ; CHECK:       innerexiting:
 440 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @unknown(i32 0)
 441 ; CHECK-NEXT:    br i1 [[C2]], label [[INNERLATCH:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT:%.*]]
 442 ; CHECK:       innerLatch:
 443 ; CHECK-NEXT:    br i1 false, label [[INNERH_1:%.*]], label [[OUTERLATCH:%.*]]
 444 ; CHECK:       innerH.1:
 445 ; CHECK-NEXT:    [[C1_1:%.*]] = call i1 @unknown(i32 0)
 446 ; CHECK-NEXT:    br i1 [[C1_1]], label [[INNEREXITING_1:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT]]
 447 ; CHECK:       innerexiting.1:
 448 ; CHECK-NEXT:    [[C2_1:%.*]] = call i1 @unknown(i32 0)
 449 ; CHECK-NEXT:    br i1 [[C2_1]], label [[INNERLATCH_1:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT]]
 450 ; CHECK:       innerLatch.1:
 451 ; CHECK-NEXT:    br i1 false, label [[INNERH_2:%.*]], label [[OUTERLATCH]]
 452 ; CHECK:       innerH.2:
 453 ; CHECK-NEXT:    [[C1_2:%.*]] = call i1 @unknown(i32 0)
 454 ; CHECK-NEXT:    br i1 [[C1_2]], label [[INNEREXITING_2:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT]]
 455 ; CHECK:       innerexiting.2:
 456 ; CHECK-NEXT:    [[C2_2:%.*]] = call i1 @unknown(i32 0)
 457 ; CHECK-NEXT:    br i1 [[C2_2]], label [[INNERLATCH_2:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT]]
 458 ; CHECK:       innerLatch.2:
 459 ; CHECK-NEXT:    br i1 false, label [[INNERH_3:%.*]], label [[OUTERLATCH]]
 460 ; CHECK:       innerH.3:
 461 ; CHECK-NEXT:    [[C1_3:%.*]] = call i1 @unknown(i32 0)
 462 ; CHECK-NEXT:    br i1 [[C1_3]], label [[INNEREXITING_3:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT]]
 463 ; CHECK:       innerexiting.3:
 464 ; CHECK-NEXT:    [[C2_3:%.*]] = call i1 @unknown(i32 0)
 465 ; CHECK-NEXT:    br i1 [[C2_3]], label [[INNERLATCH_3:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT]]
 466 ; CHECK:       innerLatch.3:
 467 ; CHECK-NEXT:    br i1 false, label [[INNERH]], label [[OUTERLATCH]], !llvm.loop [[LOOP6]]
 468 ; CHECK:       outerLatch:
 469 ; CHECK-NEXT:    br label [[INNERH_14:%.*]]
 470 ; CHECK:       innerH.14:
 471 ; CHECK-NEXT:    [[C1_13:%.*]] = call i1 @unknown(i32 0)
 472 ; CHECK-NEXT:    br i1 [[C1_13]], label [[INNEREXITING_16:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT18:%.*]]
 473 ; CHECK:       innerexiting.16:
 474 ; CHECK-NEXT:    [[C2_15:%.*]] = call i1 @unknown(i32 0)
 475 ; CHECK-NEXT:    br i1 [[C2_15]], label [[INNERLATCH_17:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT19:%.*]]
 476 ; CHECK:       innerLatch.17:
 477 ; CHECK-NEXT:    br i1 false, label [[INNERH_1_1:%.*]], label [[OUTERLATCH_1:%.*]]
 478 ; CHECK:       innerH.1.1:
 479 ; CHECK-NEXT:    [[C1_1_1:%.*]] = call i1 @unknown(i32 0)
 480 ; CHECK-NEXT:    br i1 [[C1_1_1]], label [[INNEREXITING_1_1:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT18]]
 481 ; CHECK:       innerexiting.1.1:
 482 ; CHECK-NEXT:    [[C2_1_1:%.*]] = call i1 @unknown(i32 0)
 483 ; CHECK-NEXT:    br i1 [[C2_1_1]], label [[INNERLATCH_1_1:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT19]]
 484 ; CHECK:       innerLatch.1.1:
 485 ; CHECK-NEXT:    br i1 false, label [[INNERH_2_1:%.*]], label [[OUTERLATCH_1]]
 486 ; CHECK:       innerH.2.1:
 487 ; CHECK-NEXT:    [[C1_2_1:%.*]] = call i1 @unknown(i32 0)
 488 ; CHECK-NEXT:    br i1 [[C1_2_1]], label [[INNEREXITING_2_1:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT18]]
 489 ; CHECK:       innerexiting.2.1:
 490 ; CHECK-NEXT:    [[C2_2_1:%.*]] = call i1 @unknown(i32 0)
 491 ; CHECK-NEXT:    br i1 [[C2_2_1]], label [[INNERLATCH_2_1:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT19]]
 492 ; CHECK:       innerLatch.2.1:
 493 ; CHECK-NEXT:    br i1 false, label [[INNERH_3_1:%.*]], label [[OUTERLATCH_1]]
 494 ; CHECK:       innerH.3.1:
 495 ; CHECK-NEXT:    [[C1_3_1:%.*]] = call i1 @unknown(i32 0)
 496 ; CHECK-NEXT:    br i1 [[C1_3_1]], label [[INNEREXITING_3_1:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT18]]
 497 ; CHECK:       innerexiting.3.1:
 498 ; CHECK-NEXT:    [[C2_3_1:%.*]] = call i1 @unknown(i32 0)
 499 ; CHECK-NEXT:    br i1 [[C2_3_1]], label [[INNERLATCH_3_1:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT19]]
 500 ; CHECK:       innerLatch.3.1:
 501 ; CHECK-NEXT:    br i1 false, label [[INNERH_14]], label [[OUTERLATCH_1]], !llvm.loop [[LOOP6]]
 502 ; CHECK:       outerLatch.1:
 503 ; CHECK-NEXT:    br label [[INNERH_29:%.*]]
 504 ; CHECK:       innerH.29:
 505 ; CHECK-NEXT:    [[C1_28:%.*]] = call i1 @unknown(i32 0)
 506 ; CHECK-NEXT:    br i1 [[C1_28]], label [[INNEREXITING_211:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT20:%.*]]
 507 ; CHECK:       innerexiting.211:
 508 ; CHECK-NEXT:    [[C2_210:%.*]] = call i1 @unknown(i32 0)
 509 ; CHECK-NEXT:    br i1 [[C2_210]], label [[INNERLATCH_212:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT21:%.*]]
 510 ; CHECK:       innerLatch.212:
 511 ; CHECK-NEXT:    br i1 false, label [[INNERH_1_2:%.*]], label [[OUTERLATCH_2:%.*]]
 512 ; CHECK:       innerH.1.2:
 513 ; CHECK-NEXT:    [[C1_1_2:%.*]] = call i1 @unknown(i32 0)
 514 ; CHECK-NEXT:    br i1 [[C1_1_2]], label [[INNEREXITING_1_2:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT20]]
 515 ; CHECK:       innerexiting.1.2:
 516 ; CHECK-NEXT:    [[C2_1_2:%.*]] = call i1 @unknown(i32 0)
 517 ; CHECK-NEXT:    br i1 [[C2_1_2]], label [[INNERLATCH_1_2:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT21]]
 518 ; CHECK:       innerLatch.1.2:
 519 ; CHECK-NEXT:    br i1 false, label [[INNERH_2_2:%.*]], label [[OUTERLATCH_2]]
 520 ; CHECK:       innerH.2.2:
 521 ; CHECK-NEXT:    [[C1_2_2:%.*]] = call i1 @unknown(i32 0)
 522 ; CHECK-NEXT:    br i1 [[C1_2_2]], label [[INNEREXITING_2_2:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT20]]
 523 ; CHECK:       innerexiting.2.2:
 524 ; CHECK-NEXT:    [[C2_2_2:%.*]] = call i1 @unknown(i32 0)
 525 ; CHECK-NEXT:    br i1 [[C2_2_2]], label [[INNERLATCH_2_2:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT21]]
 526 ; CHECK:       innerLatch.2.2:
 527 ; CHECK-NEXT:    br i1 false, label [[INNERH_3_2:%.*]], label [[OUTERLATCH_2]]
 528 ; CHECK:       innerH.3.2:
 529 ; CHECK-NEXT:    [[C1_3_2:%.*]] = call i1 @unknown(i32 0)
 530 ; CHECK-NEXT:    br i1 [[C1_3_2]], label [[INNEREXITING_3_2:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT20]]
 531 ; CHECK:       innerexiting.3.2:
 532 ; CHECK-NEXT:    [[C2_3_2:%.*]] = call i1 @unknown(i32 0)
 533 ; CHECK-NEXT:    br i1 [[C2_3_2]], label [[INNERLATCH_3_2:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT21]]
 534 ; CHECK:       innerLatch.3.2:
 535 ; CHECK-NEXT:    br i1 false, label [[INNERH_29]], label [[OUTERLATCH_2]], !llvm.loop [[LOOP6]]
 536 ; CHECK:       outerLatch.2:
 537 ; CHECK-NEXT:    br label [[INNERH_314:%.*]]
 538 ; CHECK:       innerH.314:
 539 ; CHECK-NEXT:    [[C1_313:%.*]] = call i1 @unknown(i32 0)
 540 ; CHECK-NEXT:    br i1 [[C1_313]], label [[INNEREXITING_316:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT22:%.*]]
 541 ; CHECK:       innerexiting.316:
 542 ; CHECK-NEXT:    [[C2_315:%.*]] = call i1 @unknown(i32 0)
 543 ; CHECK-NEXT:    br i1 [[C2_315]], label [[INNERLATCH_317:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT23:%.*]]
 544 ; CHECK:       innerLatch.317:
 545 ; CHECK-NEXT:    br i1 false, label [[INNERH_1_3:%.*]], label [[OUTERLATCH_3]]
 546 ; CHECK:       innerH.1.3:
 547 ; CHECK-NEXT:    [[C1_1_3:%.*]] = call i1 @unknown(i32 0)
 548 ; CHECK-NEXT:    br i1 [[C1_1_3]], label [[INNEREXITING_1_3:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT22]]
 549 ; CHECK:       innerexiting.1.3:
 550 ; CHECK-NEXT:    [[C2_1_3:%.*]] = call i1 @unknown(i32 0)
 551 ; CHECK-NEXT:    br i1 [[C2_1_3]], label [[INNERLATCH_1_3:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT23]]
 552 ; CHECK:       innerLatch.1.3:
 553 ; CHECK-NEXT:    br i1 false, label [[INNERH_2_3:%.*]], label [[OUTERLATCH_3]]
 554 ; CHECK:       innerH.2.3:
 555 ; CHECK-NEXT:    [[C1_2_3:%.*]] = call i1 @unknown(i32 0)
 556 ; CHECK-NEXT:    br i1 [[C1_2_3]], label [[INNEREXITING_2_3:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT22]]
 557 ; CHECK:       innerexiting.2.3:
 558 ; CHECK-NEXT:    [[C2_2_3:%.*]] = call i1 @unknown(i32 0)
 559 ; CHECK-NEXT:    br i1 [[C2_2_3]], label [[INNERLATCH_2_3:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT23]]
 560 ; CHECK:       innerLatch.2.3:
 561 ; CHECK-NEXT:    br i1 false, label [[INNERH_3_3:%.*]], label [[OUTERLATCH_3]]
 562 ; CHECK:       innerH.3.3:
 563 ; CHECK-NEXT:    [[C1_3_3:%.*]] = call i1 @unknown(i32 0)
 564 ; CHECK-NEXT:    br i1 [[C1_3_3]], label [[INNEREXITING_3_3:%.*]], label [[OTHEREXITB_LOOPEXIT_LOOPEXIT22]]
 565 ; CHECK:       innerexiting.3.3:
 566 ; CHECK-NEXT:    [[C2_3_3:%.*]] = call i1 @unknown(i32 0)
 567 ; CHECK-NEXT:    br i1 [[C2_3_3]], label [[INNERLATCH_3_3:%.*]], label [[EXITB_LOOPEXIT_LOOPEXIT_LOOPEXIT23]]
 568 ; CHECK:       innerLatch.3.3:
 569 ; CHECK-NEXT:    br i1 false, label [[INNERH_314]], label [[OUTERLATCH_3]], !llvm.loop [[LOOP6]]
 570 ; CHECK:       outerLatch.3:
 571 ; CHECK-NEXT:    [[TMP6_3]] = add i32 [[TMP4]], 4
 572 ; CHECK-NEXT:    [[TMP7_3:%.*]] = icmp sgt i32 [[TMP6_3]], 79
 573 ; CHECK-NEXT:    br i1 [[TMP7_3]], label [[OUTERLATCHEXIT_LOOPEXIT_UNR_LCSSA:%.*]], label [[OUTERH]], !llvm.loop [[LOOP8:![0-9]+]]
 574 ; CHECK:       outerLatchExit.loopexit.unr-lcssa:
 575 ; CHECK-NEXT:    br label [[OUTERLATCHEXIT_LOOPEXIT]]
 576 ; CHECK:       outerLatchExit.loopexit:
 577 ; CHECK-NEXT:    br label [[OUTERLATCHEXIT]]
 578 ; CHECK:       outerLatchExit:
 579 ; CHECK-NEXT:    ret void
 580 ; CHECK:       exitB.loopexit.loopexit.loopexit:
 581 ; CHECK-NEXT:    br label [[EXITB_LOOPEXIT_LOOPEXIT:%.*]]
 582 ; CHECK:       exitB.loopexit.loopexit.loopexit19:
 583 ; CHECK-NEXT:    br label [[EXITB_LOOPEXIT_LOOPEXIT]]
 584 ; CHECK:       exitB.loopexit.loopexit.loopexit21:
 585 ; CHECK-NEXT:    br label [[EXITB_LOOPEXIT_LOOPEXIT]]
 586 ; CHECK:       exitB.loopexit.loopexit.loopexit23:
 587 ; CHECK-NEXT:    br label [[EXITB_LOOPEXIT_LOOPEXIT]]
 588 ; CHECK:       exitB.loopexit.loopexit:
 589 ; CHECK-NEXT:    br label [[EXITB_LOOPEXIT:%.*]]
 590 ; CHECK:       exitB.loopexit.loopexit2:
 591 ; CHECK-NEXT:    br label [[EXITB_LOOPEXIT]]
 592 ; CHECK:       exitB.loopexit:
 593 ; CHECK-NEXT:    br label [[EXITB:%.*]]
 594 ; CHECK:       exitB:
 595 ; CHECK-NEXT:    ret void
 596 ; CHECK:       otherexitB.loopexit.loopexit:
 597 ; CHECK-NEXT:    br label [[OTHEREXITB_LOOPEXIT:%.*]]
 598 ; CHECK:       otherexitB.loopexit.loopexit18:
 599 ; CHECK-NEXT:    br label [[OTHEREXITB_LOOPEXIT]]
 600 ; CHECK:       otherexitB.loopexit.loopexit20:
 601 ; CHECK-NEXT:    br label [[OTHEREXITB_LOOPEXIT]]
 602 ; CHECK:       otherexitB.loopexit.loopexit22:
 603 ; CHECK-NEXT:    br label [[OTHEREXITB_LOOPEXIT]]
 604 ; CHECK:       otherexitB.loopexit:
 605 ; CHECK-NEXT:    br label [[OTHEREXITB:%.*]]
 606 ; CHECK:       otherexitB.loopexit1:
 607 ; CHECK-NEXT:    br label [[OTHEREXITB]]
 608 ; CHECK:       otherexitB:
 609 ; CHECK-NEXT:    br label [[EXITB]]
 610 ;
 611 bb:
 612   %tmp = icmp sgt i32 undef, 79
 613   br i1 %tmp, label %outerLatchExit, label %bb1
 614
 615 bb1:                                              ; preds = %bb
 616   br label %outerH
 617
 618 outerH:                                              ; preds = %outerLatch, %bb1
 619   %tmp4 = phi i32 [ %tmp6, %outerLatch ], [ undef, %bb1 ]
 620   br label %innerH
 621
 622 innerH:                                              ; preds = %innerLatch, %outerH
 623   %c1 = call i1 @unknown(i32 0)
 624   br i1 %c1, label %innerexiting, label %otherexitB
 625
 626 innerexiting:                                             ; preds = %innerH
 627   %c2 = call i1 @unknown(i32 0)
 628   br i1 %c2, label %innerLatch, label %exitB
 629
 630 innerLatch:                                             ; preds = %innerexiting
 631   %tmp13 = fcmp olt double undef, 2.000000e+00
 632   br i1 %tmp13, label %innerH, label %outerLatch
 633
 634 outerLatch:                                              ; preds = %innerLatch
 635   %tmp6 = add i32 %tmp4, 1
 636   %tmp7 = icmp sgt i32 %tmp6, 79
 637   br i1 %tmp7, label %outerLatchExit, label %outerH
 638
 639 outerLatchExit:                                              ; preds = %outerLatch, %bb
 640   ret void
 641
 642 exitB:                                             ; preds = %innerexiting, %otherexitB
 643   ret void
 644
 645 otherexitB:                                              ; preds = %innerH
 646   br label %exitB
 647
 648 }
 649
 650 ; Blocks reachable from exits (not_zero44) have the IDom as the block within the loop (Header).
 651 ; Update the IDom to the preheader.
 652 define void @test6(i64 %start) {
 653 ; CHECK-LABEL: @test6(
 654 ; CHECK-NEXT:  entry:
 655 ; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[START:%.*]], 2
 656 ; CHECK-NEXT:    [[SMAX:%.*]] = call i64 @llvm.smax.i64(i64 [[TMP0]], i64 616)
 657 ; CHECK-NEXT:    [[TMP1:%.*]] = add i64 [[SMAX]], -1
 658 ; CHECK-NEXT:    [[TMP2:%.*]] = sub i64 [[TMP1]], [[START]]
 659 ; CHECK-NEXT:    [[TMP3:%.*]] = lshr i64 [[TMP2]], 1
 660 ; CHECK-NEXT:    [[TMP4:%.*]] = add nuw i64 [[TMP3]], 1
 661 ; CHECK-NEXT:    [[TMP5:%.*]] = freeze i64 [[TMP4]]
 662 ; CHECK-NEXT:    [[TMP6:%.*]] = add i64 [[TMP5]], -1
 663 ; CHECK-NEXT:    [[XTRAITER:%.*]] = and i64 [[TMP5]], 3
 664 ; CHECK-NEXT:    [[LCMP_MOD:%.*]] = icmp ne i64 [[XTRAITER]], 0
 665 ; CHECK-NEXT:    br i1 [[LCMP_MOD]], label [[HEADER_PROL_PREHEADER:%.*]], label [[HEADER_PROL_LOOPEXIT:%.*]]
 666 ; CHECK:       header.prol.preheader:
 667 ; CHECK-NEXT:    br label [[HEADER_PROL:%.*]]
 668 ; CHECK:       header.prol:
 669 ; CHECK-NEXT:    [[INDVARS_IV_PROL:%.*]] = phi i64 [ [[START]], [[HEADER_PROL_PREHEADER]] ], [ [[INDVARS_IV_NEXT_PROL:%.*]], [[LATCH_PROL:%.*]] ]
 670 ; CHECK-NEXT:    [[PROL_ITER:%.*]] = phi i64 [ 0, [[HEADER_PROL_PREHEADER]] ], [ [[PROL_ITER_NEXT:%.*]], [[LATCH_PROL]] ]
 671 ; CHECK-NEXT:    [[IV_I32_PROL:%.*]] = trunc i64 [[INDVARS_IV_PROL]] to i32
 672 ; CHECK-NEXT:    [[C1_PROL:%.*]] = call i1 @unknown(i32 [[IV_I32_PROL]])
 673 ; CHECK-NEXT:    br i1 [[C1_PROL]], label [[LATCH_PROL]], label [[OTHEREXIT_LOOPEXIT1:%.*]]
 674 ; CHECK:       latch.prol:
 675 ; CHECK-NEXT:    [[INDVARS_IV_NEXT_PROL]] = add nsw i64 [[INDVARS_IV_PROL]], 2
 676 ; CHECK-NEXT:    [[TMP7:%.*]] = icmp slt i64 [[INDVARS_IV_NEXT_PROL]], 616
 677 ; CHECK-NEXT:    [[PROL_ITER_NEXT]] = add i64 [[PROL_ITER]], 1
 678 ; CHECK-NEXT:    [[PROL_ITER_CMP:%.*]] = icmp ne i64 [[PROL_ITER_NEXT]], [[XTRAITER]]
 679 ; CHECK-NEXT:    br i1 [[PROL_ITER_CMP]], label [[HEADER_PROL]], label [[HEADER_PROL_LOOPEXIT_UNR_LCSSA:%.*]], !llvm.loop [[LOOP9:![0-9]+]]
 680 ; CHECK:       header.prol.loopexit.unr-lcssa:
 681 ; CHECK-NEXT:    [[INDVARS_IV_UNR_PH:%.*]] = phi i64 [ [[INDVARS_IV_NEXT_PROL]], [[LATCH_PROL]] ]
 682 ; CHECK-NEXT:    br label [[HEADER_PROL_LOOPEXIT]]
 683 ; CHECK:       header.prol.loopexit:
 684 ; CHECK-NEXT:    [[INDVARS_IV_UNR:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[INDVARS_IV_UNR_PH]], [[HEADER_PROL_LOOPEXIT_UNR_LCSSA]] ]
 685 ; CHECK-NEXT:    [[TMP8:%.*]] = icmp ult i64 [[TMP6]], 3
 686 ; CHECK-NEXT:    br i1 [[TMP8]], label [[LATCHEXIT:%.*]], label [[ENTRY_NEW:%.*]]
 687 ; CHECK:       entry.new:
 688 ; CHECK-NEXT:    br label [[HEADER:%.*]]
 689 ; CHECK:       header:
 690 ; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_UNR]], [[ENTRY_NEW]] ], [ [[INDVARS_IV_NEXT_3:%.*]], [[LATCH_3:%.*]] ]
 691 ; CHECK-NEXT:    [[IV_I32:%.*]] = trunc i64 [[INDVARS_IV]] to i32
 692 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @unknown(i32 [[IV_I32]])
 693 ; CHECK-NEXT:    br i1 [[C1]], label [[LATCH:%.*]], label [[OTHEREXIT_LOOPEXIT:%.*]]
 694 ; CHECK:       latch:
 695 ; CHECK-NEXT:    [[INDVARS_IV_NEXT:%.*]] = add nsw i64 [[INDVARS_IV]], 2
 696 ; CHECK-NEXT:    [[IV_I32_1:%.*]] = trunc i64 [[INDVARS_IV_NEXT]] to i32
 697 ; CHECK-NEXT:    [[C1_1:%.*]] = call i1 @unknown(i32 [[IV_I32_1]])
 698 ; CHECK-NEXT:    br i1 [[C1_1]], label [[LATCH_1:%.*]], label [[OTHEREXIT_LOOPEXIT]]
 699 ; CHECK:       latch.1:
 700 ; CHECK-NEXT:    [[INDVARS_IV_NEXT_1:%.*]] = add nsw i64 [[INDVARS_IV]], 4
 701 ; CHECK-NEXT:    [[IV_I32_2:%.*]] = trunc i64 [[INDVARS_IV_NEXT_1]] to i32
 702 ; CHECK-NEXT:    [[C1_2:%.*]] = call i1 @unknown(i32 [[IV_I32_2]])
 703 ; CHECK-NEXT:    br i1 [[C1_2]], label [[LATCH_2:%.*]], label [[OTHEREXIT_LOOPEXIT]]
 704 ; CHECK:       latch.2:
 705 ; CHECK-NEXT:    [[INDVARS_IV_NEXT_2:%.*]] = add nsw i64 [[INDVARS_IV]], 6
 706 ; CHECK-NEXT:    [[IV_I32_3:%.*]] = trunc i64 [[INDVARS_IV_NEXT_2]] to i32
 707 ; CHECK-NEXT:    [[C1_3:%.*]] = call i1 @unknown(i32 [[IV_I32_3]])
 708 ; CHECK-NEXT:    br i1 [[C1_3]], label [[LATCH_3]], label [[OTHEREXIT_LOOPEXIT]]
 709 ; CHECK:       latch.3:
 710 ; CHECK-NEXT:    [[INDVARS_IV_NEXT_3]] = add nsw i64 [[INDVARS_IV]], 8
 711 ; CHECK-NEXT:    [[TMP9:%.*]] = icmp slt i64 [[INDVARS_IV_NEXT_3]], 616
 712 ; CHECK-NEXT:    br i1 [[TMP9]], label [[HEADER]], label [[LATCHEXIT_UNR_LCSSA:%.*]], !llvm.loop [[LOOP10:![0-9]+]]
 713 ; CHECK:       latchexit.unr-lcssa:
 714 ; CHECK-NEXT:    br label [[LATCHEXIT]]
 715 ; CHECK:       latchexit:
 716 ; CHECK-NEXT:    br label [[LATCHEXITSUCC:%.*]]
 717 ; CHECK:       otherexit.loopexit:
 718 ; CHECK-NEXT:    br label [[OTHEREXIT:%.*]]
 719 ; CHECK:       otherexit.loopexit1:
 720 ; CHECK-NEXT:    br label [[OTHEREXIT]]
 721 ; CHECK:       otherexit:
 722 ; CHECK-NEXT:    br label [[OTHEREXITSUCC:%.*]]
 723 ; CHECK:       otherexitsucc:
 724 ; CHECK-NEXT:    br label [[NOT_ZERO44:%.*]]
 725 ; CHECK:       not_zero44:
 726 ; CHECK-NEXT:    unreachable
 727 ; CHECK:       latchexitsucc:
 728 ; CHECK-NEXT:    br label [[NOT_ZERO44]]
 729 ;
 730 entry:
 731   br label %header
 732
 733 header:                                          ; preds = %latch, %entry
 734   %indvars.iv = phi i64 [ %start, %entry ], [ %indvars.iv.next, %latch ]
 735   %iv.i32 = trunc i64 %indvars.iv to i32
 736   %c1 = call i1 @unknown(i32 %iv.i32)
 737   br i1 %c1, label %latch, label %otherexit
 738
 739 latch:                                         ; preds = %header
 740   %indvars.iv.next = add nsw i64 %indvars.iv, 2
 741   %0 = icmp slt i64 %indvars.iv.next, 616
 742   br i1 %0, label %header, label %latchexit
 743
 744 latchexit:                                          ; preds = %latch
 745   br label %latchexitsucc
 746
 747 otherexit:                                 ; preds = %header
 748   br label %otherexitsucc
 749
 750 otherexitsucc:                                          ; preds = %otherexit
 751   br label %not_zero44
 752
 753 not_zero44:                                       ; preds = %latchexitsucc, %otherexitsucc
 754   unreachable
 755
 756 latchexitsucc:                                      ; preds = %latchexit
 757   br label %not_zero44
 758 }
 759