ppc-shrink-wrapping.ll 23.8 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791
; RUN: llc -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 %s -o - -verify-machineinstrs | FileCheck %s --check-prefix=CHECK --check-prefix=ENABLE
; RUN: llc -mtriple=powerpc64le-unknown-linux-gnu %s -o - -enable-shrink-wrap=false -verify-machineinstrs |  FileCheck %s --check-prefix=CHECK --check-prefix=DISABLE
;
; Note: Lots of tests use inline asm instead of regular calls.
; This allows to have a better control on what the allocation will do.
; Otherwise, we may have spill right in the entry block, defeating
; shrink-wrapping. Moreover, some of the inline asm statement (nop)
; are here to ensure that the related paths do not end up as critical
; edges.


; Initial motivating example: Simple diamond with a call just on one side.
; CHECK-LABEL: foo:
;
; Compare the arguments and return
; No prologue needed.
; ENABLE: cmpw 0, 3, 4
; ENABLE-NEXT: bgelr 0
;
; Prologue code.
;  At a minimum, we save/restore the link register. Other registers may be saved
;  as well. 
; CHECK: mflr 
;
; Compare the arguments and jump to exit.
; After the prologue is set.
; DISABLE: cmpw 0, 3, 4
; DISABLE-NEXT: bge 0, .[[EXIT_LABEL:LBB[0-9_]+]]
;
; Store %a on the stack
; CHECK: stw 3, {{[0-9]+([0-9]+)}}
; Set the alloca address in the second argument.
; CHECK-NEXT: addi 4, 1, {{[0-9]+}}
; Set the first argument to zero.
; CHECK-NEXT: li 3, 0
; CHECK-NEXT: bl doSomething
;
; With shrink-wrapping, epilogue is just after the call.
; Restore the link register and return.
; Note that there could be other epilog code before the link register is 
; restored but we will not check for it here.
; ENABLE: mtlr
; ENABLE-NEXT: blr
;
; DISABLE: [[EXIT_LABEL]]:
;
; Without shrink-wrapping, epilogue is in the exit block.
; Epilogue code. (What we pop does not matter.)
; DISABLE: mtlr {{[0-9]+}}
; DISABLE-NEXT: blr
;

define i32 @foo(i32 %a, i32 %b) {
  %tmp = alloca i32, align 4
  %tmp2 = icmp slt i32 %a, %b
  br i1 %tmp2, label %true, label %false

true:
  store i32 %a, i32* %tmp, align 4
  %tmp4 = call i32 @doSomething(i32 0, i32* %tmp)
  br label %false

false:
  %tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ]
  ret i32 %tmp.0
}

; Function Attrs: optsize
declare i32 @doSomething(i32, i32*)



; Check that we do not perform the restore inside the loop whereas the save
; is outside.
; CHECK-LABEL: freqSaveAndRestoreOutsideLoop:
;
; Shrink-wrapping allows to skip the prologue in the else case.
; ENABLE: cmplwi 0, 3, 0
; ENABLE: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; Make sure we save the link register
; CHECK: mflr {{[0-9]+}}
;
; DISABLE: cmplwi 0, 3, 0
; DISABLE: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Loop preheader
; CHECK-DAG: li [[SUM:[0-9]+]], 0
; CHECK-DAG: li [[IV:[0-9]+]], 10
; 
; Loop body
; CHECK: .[[LOOP:LBB[0-9_]+]]: # %for.body
; CHECK: bl something
; CHECK-DAG: addi [[IV]], [[IV]], -1
; CHECK-DAG: add [[SUM]], 3, [[SUM]] 
; CHECK-NEXT: cmplwi [[IV]], 0
; CHECK-NEXT: bne 0, .[[LOOP]]
;
; Next BB.
; CHECK: slwi 3, [[SUM]], 3
;
; Jump to epilogue.
; DISABLE: b .[[EPILOG_BB:LBB[0-9_]+]]
;
; DISABLE: .[[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; DISABLE: slwi 3, 4, 1
; DISABLE: .[[EPILOG_BB]]: # %if.end
;
; Epilogue code.
; CHECK: mtlr {{[0-9]+}}
; CHECK: blr
;
; ENABLE: .[[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; ENABLE: slwi 3, 4, 1
; ENABLE-NEXT: blr
define i32 @freqSaveAndRestoreOutsideLoop(i32 %cond, i32 %N) {
entry:
  %tobool = icmp eq i32 %cond, 0
  br i1 %tobool, label %if.else, label %for.preheader

for.preheader:
  tail call void asm "nop", ""()
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %i.05 = phi i32 [ %inc, %for.body ], [ 0, %for.preheader ]
  %sum.04 = phi i32 [ %add, %for.body ], [ 0, %for.preheader ]
  %call = tail call i32 bitcast (i32 (...)* @something to i32 ()*)()
  %add = add nsw i32 %call, %sum.04
  %inc = add nuw nsw i32 %i.05, 1
  %exitcond = icmp eq i32 %inc, 10
  br i1 %exitcond, label %for.end, label %for.body

for.end:                                          ; preds = %for.body
  %shl = shl i32 %add, 3
  br label %if.end

if.else:                                          ; preds = %entry
  %mul = shl nsw i32 %N, 1
  br label %if.end

if.end:                                           ; preds = %if.else, %for.end
  %sum.1 = phi i32 [ %shl, %for.end ], [ %mul, %if.else ]
  ret i32 %sum.1
}

declare i32 @something(...)

; Check that we do not perform the shrink-wrapping inside the loop even
; though that would be legal. The cost model must prevent that.
; CHECK-LABEL: freqSaveAndRestoreOutsideLoop2:
; Prologue code.
; Make sure we save the link register before the call
; CHECK: mflr {{[0-9]+}}
;
; Loop preheader
; CHECK-DAG: li [[SUM:[0-9]+]], 0
; CHECK-DAG: li [[IV:[0-9]+]], 10
; 
; Loop body
; CHECK: .[[LOOP:LBB[0-9_]+]]: # %for.body
; CHECK: bl something
; CHECK-DAG: addi [[IV]], [[IV]], -1
; CHECK-DAG: add [[SUM]], 3, [[SUM]] 
; CHECK-NEXT: cmplwi [[IV]], 0
; CHECK-NEXT: bne 0, .[[LOOP]]
;
; Next BB
; CHECK: %for.exit
; CHECK: mtlr {{[0-9]+}}
; CHECK: blr
define i32 @freqSaveAndRestoreOutsideLoop2(i32 %cond) {
entry:
  br label %for.preheader

for.preheader:
  tail call void asm "nop", ""()
  br label %for.body

for.body:                                         ; preds = %for.body, %entry
  %i.04 = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]
  %sum.03 = phi i32 [ 0, %for.preheader ], [ %add, %for.body ]
  %call = tail call i32 bitcast (i32 (...)* @something to i32 ()*)()
  %add = add nsw i32 %call, %sum.03
  %inc = add nuw nsw i32 %i.04, 1
  %exitcond = icmp eq i32 %inc, 10
  br i1 %exitcond, label %for.exit, label %for.body

for.exit:
  tail call void asm "nop", ""()
  br label %for.end

for.end:                                          ; preds = %for.body
  ret i32 %add
}


; Check with a more complex case that we do not have save within the loop and
; restore outside.
; CHECK-LABEL: loopInfoSaveOutsideLoop:
;
; ENABLE: cmplwi 0, 3, 0
; ENABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; Make sure we save the link register 
; CHECK: mflr {{[0-9]+}}
;
; DISABLE: std
; DISABLE-NEXT: std
; DISABLE: cmplwi 0, 3, 0
; DISABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Loop preheader
; CHECK-DAG: li [[SUM:[0-9]+]], 0
; CHECK-DAG: li [[IV:[0-9]+]], 10
; 
; Loop body
; CHECK: .[[LOOP:LBB[0-9_]+]]: # %for.body
; CHECK: bl something
; CHECK-DAG: addi [[IV]], [[IV]], -1
; CHECK-DAG: add [[SUM]], 3, [[SUM]] 
; CHECK-NEXT: cmplwi [[IV]], 0
; CHECK-NEXT: bne 0, .[[LOOP]]
; 
; Next BB
; CHECK: bl somethingElse 
; CHECK: slwi 3, [[SUM]], 3
;
; Jump to epilogue
; DISABLE: b .[[EPILOG_BB:LBB[0-9_]+]]
;
; DISABLE: .[[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; DISABLE: slwi 3, 4, 1
;
; DISABLE: .[[EPILOG_BB]]: # %if.end
; Epilog code
; CHECK: mtlr {{[0-9]+}}
; CHECK: blr
; 
; ENABLE: .[[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; ENABLE: slwi 3, 4, 1
; ENABLE-NEXT: blr
define i32 @loopInfoSaveOutsideLoop(i32 %cond, i32 %N) {
entry:
  %tobool = icmp eq i32 %cond, 0
  br i1 %tobool, label %if.else, label %for.preheader

for.preheader:
  tail call void asm "nop", ""()
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %i.05 = phi i32 [ %inc, %for.body ], [ 0, %for.preheader ]
  %sum.04 = phi i32 [ %add, %for.body ], [ 0, %for.preheader ]
  %call = tail call i32 bitcast (i32 (...)* @something to i32 ()*)()
  %add = add nsw i32 %call, %sum.04
  %inc = add nuw nsw i32 %i.05, 1
  %exitcond = icmp eq i32 %inc, 10
  br i1 %exitcond, label %for.end, label %for.body

for.end:                                          ; preds = %for.body
  tail call void bitcast (void (...)* @somethingElse to void ()*)()
  %shl = shl i32 %add, 3
  br label %if.end

if.else:                                          ; preds = %entry
  %mul = shl nsw i32 %N, 1
  br label %if.end

if.end:                                           ; preds = %if.else, %for.end
  %sum.1 = phi i32 [ %shl, %for.end ], [ %mul, %if.else ]
  ret i32 %sum.1
}

declare void @somethingElse(...)

; Check with a more complex case that we do not have restore within the loop and
; save outside.
; CHECK-LABEL: loopInfoRestoreOutsideLoop:
;
; ENABLE: cmplwi 0, 3, 0
; ENABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; Make sure we save the link register
; CHECK: mflr {{[0-9]+}}
;
; DISABLE: std
; DISABLE-NEXT: std
; DISABLE: cmplwi 0, 3, 0
; DISABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; CHECK: bl somethingElse
;
; Loop preheader
; CHECK-DAG: li [[SUM:[0-9]+]], 0
; CHECK-DAG: li [[IV:[0-9]+]], 10
; 
; Loop body
; CHECK: .[[LOOP:LBB[0-9_]+]]: # %for.body
; CHECK: bl something
; CHECK-DAG: addi [[IV]], [[IV]], -1
; CHECK-DAG: add [[SUM]], 3, [[SUM]] 
; CHECK-NEXT: cmplwi [[IV]], 0
; CHECK-NEXT: bne 0, .[[LOOP]]
;
; Next BB. 
; slwi 3, [[SUM]], 3
;
; DISABLE: b .[[EPILOG_BB:LBB[0-9_]+]]
;
; DISABLE: .[[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; DISABLE: slwi 3, 4, 1
; DISABLE: .[[EPILOG_BB]]: # %if.end
;
; Epilogue code.
; CHECK: mtlr {{[0-9]+}}
; CHECK: blr
;
; ENABLE: .[[ELSE_LABEL]]: # %if.else
; Shift second argument by one and store into returned register.
; ENABLE: slwi 3, 4, 1
; ENABLE-NEXT: blr
define i32 @loopInfoRestoreOutsideLoop(i32 %cond, i32 %N) nounwind {
entry:
  %tobool = icmp eq i32 %cond, 0
  br i1 %tobool, label %if.else, label %if.then

if.then:                                          ; preds = %entry
  tail call void bitcast (void (...)* @somethingElse to void ()*)()
  br label %for.body

for.body:                                         ; preds = %for.body, %if.then
  %i.05 = phi i32 [ 0, %if.then ], [ %inc, %for.body ]
  %sum.04 = phi i32 [ 0, %if.then ], [ %add, %for.body ]
  %call = tail call i32 bitcast (i32 (...)* @something to i32 ()*)()
  %add = add nsw i32 %call, %sum.04
  %inc = add nuw nsw i32 %i.05, 1
  %exitcond = icmp eq i32 %inc, 10
  br i1 %exitcond, label %for.end, label %for.body

for.end:                                          ; preds = %for.body
  %shl = shl i32 %add, 3
  br label %if.end

if.else:                                          ; preds = %entry
  %mul = shl nsw i32 %N, 1
  br label %if.end

if.end:                                           ; preds = %if.else, %for.end
  %sum.1 = phi i32 [ %shl, %for.end ], [ %mul, %if.else ]
  ret i32 %sum.1
}

; Check that we handle function with no frame information correctly.
; CHECK-LABEL: emptyFrame:
; CHECK: # %entry
; CHECK-NEXT: li 3, 0
; CHECK-NEXT: blr
define i32 @emptyFrame() {
entry:
  ret i32 0
}


; Check that we handle inline asm correctly.
; CHECK-LABEL: inlineAsm:
;
; ENABLE: cmplwi 0, 3, 0
; ENABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; Make sure we save the CSR used in the inline asm: r14
; ENABLE-DAG: li [[IV:[0-9]+]], 10
; ENABLE-DAG: std 14, -[[STACK_OFFSET:[0-9]+]](1) # 8-byte Folded Spill
;
; DISABLE: cmplwi 0, 3, 0
; DISABLE-NEXT: std 14, -[[STACK_OFFSET:[0-9]+]](1) # 8-byte Folded Spill
; DISABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
; DISABLE: li [[IV:[0-9]+]], 10
;
; CHECK: nop
; CHECK: mtctr [[IV]]
;
; CHECK: .[[LOOP_LABEL:LBB[0-9_]+]]: # %for.body
; Inline asm statement.
; CHECK: addi 14, 14, 1
; CHECK: bdnz .[[LOOP_LABEL]]
;
; Epilogue code.
; CHECK: li 3, 0
; CHECK-DAG: ld 14, -[[STACK_OFFSET]](1) # 8-byte Folded Reload
; CHECK: nop
; CHECK: blr
;
; CHECK: [[ELSE_LABEL]]
; CHECK-NEXT: slwi 3, 4, 1
; DISABLE: ld 14, -[[STACK_OFFSET]](1) # 8-byte Folded Reload
; CHECK-NEXT: blr
; 
define i32 @inlineAsm(i32 %cond, i32 %N) {
entry:
  %tobool = icmp eq i32 %cond, 0
  br i1 %tobool, label %if.else, label %for.preheader

for.preheader:
  tail call void asm "nop", ""()
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %i.03 = phi i32 [ %inc, %for.body ], [ 0, %for.preheader ]
  tail call void asm "addi 14, 14, 1", "~{r14}"()
  %inc = add nuw nsw i32 %i.03, 1
  %exitcond = icmp eq i32 %inc, 10
  br i1 %exitcond, label %for.exit, label %for.body

for.exit:
  tail call void asm "nop", ""()
  br label %if.end

if.else:                                          ; preds = %entry
  %mul = shl nsw i32 %N, 1
  br label %if.end

if.end:                                           ; preds = %for.body, %if.else
  %sum.0 = phi i32 [ %mul, %if.else ], [ 0, %for.exit ]
  ret i32 %sum.0
}


; Check that we handle calls to variadic functions correctly.
; CHECK-LABEL: callVariadicFunc:
;
; ENABLE: cmplwi 0, 3, 0
; ENABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; CHECK: mflr {{[0-9]+}}
; 
; DISABLE: cmplwi 0, 3, 0
; DISABLE-NEXT: beq 0, .[[ELSE_LABEL:LBB[0-9_]+]]
;
; Setup of the varags.
; CHECK: mr 4, 3
; CHECK-NEXT: mr 5, 3
; CHECK-NEXT: mr 6, 3
; CHECK-NEXT: mr 7, 3
; CHECK-NEXT: mr 8, 3
; CHECK-NEXT: mr 9, 3
; CHECK-NEXT: bl someVariadicFunc
; CHECK: slwi 3, 3, 3
; DISABLE: b .[[EPILOGUE_BB:LBB[0-9_]+]]
;
; ENABLE: mtlr {{[0-9]+}}
; ENABLE-NEXT: blr
;
; CHECK: .[[ELSE_LABEL]]: # %if.else
; CHECK-NEXT: slwi 3, 4, 1
; 
; DISABLE: .[[EPILOGUE_BB]]: # %if.end
; DISABLE: mtlr
; CHECK: blr
define i32 @callVariadicFunc(i32 %cond, i32 %N) {
entry:
  %tobool = icmp eq i32 %cond, 0
  br i1 %tobool, label %if.else, label %if.then

if.then:                                          ; preds = %entry
  %call = tail call i32 (i32, ...) @someVariadicFunc(i32 %N, i32 %N, i32 %N, i32 %N, i32 %N, i32 %N, i32 %N)
  %shl = shl i32 %call, 3
  br label %if.end

if.else:                                          ; preds = %entry
  %mul = shl nsw i32 %N, 1
  br label %if.end

if.end:                                           ; preds = %if.else, %if.then
  %sum.0 = phi i32 [ %shl, %if.then ], [ %mul, %if.else ]
  ret i32 %sum.0
}

declare i32 @someVariadicFunc(i32, ...)



; Make sure we do not insert unreachable code after noreturn function.
; Although this is not incorrect to insert such code, it is useless
; and it hurts the binary size.
;
; CHECK-LABEL: noreturn:
; DISABLE: mflr {{[0-9]+}}
;
; CHECK: cmplwi 0, 3, 0
; CHECK-NEXT: bne{{[-]?}} 0, .[[ABORT:LBB[0-9_]+]]
;
; CHECK: li 3, 42
;
; DISABLE: mtlr {{[0-9]+}}
;
; CHECK-NEXT: blr
;
; CHECK: .[[ABORT]]: # %if.abort
;
; ENABLE: mflr {{[0-9]+}}
;
; CHECK: bl abort
; ENABLE-NOT: mtlr {{[0-9]+}}
define i32 @noreturn(i8 signext %bad_thing) {
entry:
  %tobool = icmp eq i8 %bad_thing, 0
  br i1 %tobool, label %if.end, label %if.abort

if.abort:
  tail call void @abort() #0
  unreachable

if.end:
  ret i32 42
}

declare void @abort() #0

attributes #0 = { noreturn nounwind }


; Make sure that we handle infinite loops properly When checking that the Save
; and Restore blocks are control flow equivalent, the loop searches for the
; immediate (post) dominator for the (restore) save blocks. When either the Save
; or Restore block is located in an infinite loop the only immediate (post)
; dominator is itself. In this case, we cannot perform shrink wrapping, but we
; should return gracefully and continue compilation.
; The only condition for this test is the compilation finishes correctly.
; 
; CHECK-LABEL: infiniteloop
; CHECK: blr
define void @infiniteloop() {
entry:
  br i1 undef, label %if.then, label %if.end

if.then:
  %ptr = alloca i32, i32 4
  br label %for.body

for.body:                                         ; preds = %for.body, %entry
  %sum.03 = phi i32 [ 0, %if.then ], [ %add, %for.body ]
  %call = tail call i32 bitcast (i32 (...)* @something to i32 ()*)()
  %add = add nsw i32 %call, %sum.03
  store i32 %add, i32* %ptr
  br label %for.body

if.end:
  ret void
}

; Another infinite loop test this time with a body bigger than just one block.
; CHECK-LABEL: infiniteloop2
; CHECK: blr
define void @infiniteloop2() {
entry:
  br i1 undef, label %if.then, label %if.end

if.then:
  %ptr = alloca i32, i32 4
  br label %for.body

for.body:                                         ; preds = %for.body, %entry
  %sum.03 = phi i32 [ 0, %if.then ], [ %add, %body1 ], [ 1, %body2]
  %call = tail call i32 asm "mftb $0, 268", "=r,~{r14}"()
  %add = add nsw i32 %call, %sum.03
  store i32 %add, i32* %ptr
  br i1 undef, label %body1, label %body2

body1:
  tail call void asm sideeffect "nop", "~{r14}"()
  br label %for.body

body2:
  tail call void asm sideeffect "nop", "~{r14}"()
  br label %for.body

if.end:
  ret void
}

; Another infinite loop test this time with two nested infinite loop.
; CHECK-LABEL: infiniteloop3
; CHECK: Lfunc_begin[[FUNCNUM:[0-9]+]]
; CHECK: bclr
; CHECK: Lfunc_end[[FUNCNUM]]
define void @infiniteloop3() {
entry:
  br i1 undef, label %loop2a, label %body

body:                                             ; preds = %entry
  br i1 undef, label %loop2a, label %end

loop1:                                            ; preds = %loop2a, %loop2b
  %var.phi = phi i32* [ %next.phi, %loop2b ], [ %var, %loop2a ]
  %next.phi = phi i32* [ %next.load, %loop2b ], [ %next.var, %loop2a ]
  %0 = icmp eq i32* %var, null
  %next.load = load i32*, i32** undef
  br i1 %0, label %loop2a, label %loop2b

loop2a:                                           ; preds = %loop1, %body, %entry
  %var = phi i32* [ null, %body ], [ null, %entry ], [ %next.phi, %loop1 ]
  %next.var = phi i32* [ undef, %body ], [ null, %entry ], [ %next.load, %loop1 ]
  br label %loop1

loop2b:                                           ; preds = %loop1
  %gep1 = bitcast i32* %var.phi to i32*
  %next.ptr = bitcast i32* %gep1 to i32**
  store i32* %next.phi, i32** %next.ptr
  br label %loop1

end:
  ret void
}

@columns = external global [0 x i32], align 4
@lock = common global i32 0, align 4
@htindex = common global i32 0, align 4
@stride = common global i32 0, align 4
@ht = common global i32* null, align 8
@he = common global i8* null, align 8

; Test for a bug that was caused when save point was equal to restore point.
; Function Attrs: nounwind
; CHECK-LABEL: transpose
;
; Store of callee-save register saved by shrink wrapping
; FIXME: Test disabled: Improved scheduling needs no spills/reloads any longer!
; CHECKXX: std [[CSR:[0-9]+]], -[[STACK_OFFSET:[0-9]+]](1) # 8-byte Folded Spill
;
; Reload of callee-save register
; CHECKXX: ld [[CSR]], -[[STACK_OFFSET]](1) # 8-byte Folded Reload
;
; Ensure no subsequent uses of callee-save register before end of function
; CHECK-NOT: {{[a-z]+}} [[CSR]]
; CHECK: blr
define signext i32 @transpose() {
entry:
  %0 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 1), align 4
  %shl.i = shl i32 %0, 7
  %1 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 2), align 4
  %or.i = or i32 %shl.i, %1
  %shl1.i = shl i32 %or.i, 7
  %2 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 3), align 4
  %or2.i = or i32 %shl1.i, %2
  %3 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 7), align 4
  %shl3.i = shl i32 %3, 7
  %4 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 6), align 4
  %or4.i = or i32 %shl3.i, %4
  %shl5.i = shl i32 %or4.i, 7
  %5 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 5), align 4
  %or6.i = or i32 %shl5.i, %5
  %cmp.i = icmp ugt i32 %or2.i, %or6.i
  br i1 %cmp.i, label %cond.true.i, label %cond.false.i

cond.true.i:
  %shl7.i = shl i32 %or2.i, 7
  %6 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 4), align 4
  %or8.i = or i32 %6, %shl7.i
  %conv.i = zext i32 %or8.i to i64
  %shl9.i = shl nuw nsw i64 %conv.i, 21
  %conv10.i = zext i32 %or6.i to i64
  %or11.i = or i64 %shl9.i, %conv10.i
  br label %hash.exit

cond.false.i:
  %shl12.i = shl i32 %or6.i, 7
  %7 = load i32, i32* getelementptr inbounds ([0 x i32], [0 x i32]* @columns, i64 0, i64 4), align 4
  %or13.i = or i32 %7, %shl12.i
  %conv14.i = zext i32 %or13.i to i64
  %shl15.i = shl nuw nsw i64 %conv14.i, 21
  %conv16.i = zext i32 %or2.i to i64
  %or17.i = or i64 %shl15.i, %conv16.i
  br label %hash.exit

hash.exit:
  %cond.i = phi i64 [ %or11.i, %cond.true.i ], [ %or17.i, %cond.false.i ]
  %shr.29.i = lshr i64 %cond.i, 17
  %conv18.i = trunc i64 %shr.29.i to i32
  store i32 %conv18.i, i32* @lock, align 4
  %rem.i = srem i64 %cond.i, 1050011
  %conv19.i = trunc i64 %rem.i to i32
  store i32 %conv19.i, i32* @htindex, align 4
  %rem20.i = urem i32 %conv18.i, 179
  %add.i = or i32 %rem20.i, 131072
  store i32 %add.i, i32* @stride, align 4
  %8 = load i32*, i32** @ht, align 8
  %arrayidx = getelementptr inbounds i32, i32* %8, i64 %rem.i
  %9 = load i32, i32* %arrayidx, align 4
  %cmp1 = icmp eq i32 %9, %conv18.i
  br i1 %cmp1, label %if.then, label %if.end

if.then:
  %idxprom.lcssa = phi i64 [ %rem.i, %hash.exit ], [ %idxprom.1, %if.end ], [ %idxprom.2, %if.end.1 ], [ %idxprom.3, %if.end.2 ], [ %idxprom.4, %if.end.3 ], [ %idxprom.5, %if.end.4 ], [ %idxprom.6, %if.end.5 ], [ %idxprom.7, %if.end.6 ]
  %10 = load i8*, i8** @he, align 8
  %arrayidx3 = getelementptr inbounds i8, i8* %10, i64 %idxprom.lcssa
  %11 = load i8, i8* %arrayidx3, align 1
  %conv = sext i8 %11 to i32
  br label %cleanup

if.end:
  %add = add nsw i32 %add.i, %conv19.i
  %cmp4 = icmp sgt i32 %add, 1050010
  %sub = add nsw i32 %add, -1050011
  %sub.add = select i1 %cmp4, i32 %sub, i32 %add
  %idxprom.1 = sext i32 %sub.add to i64
  %arrayidx.1 = getelementptr inbounds i32, i32* %8, i64 %idxprom.1
  %12 = load i32, i32* %arrayidx.1, align 4
  %cmp1.1 = icmp eq i32 %12, %conv18.i
  br i1 %cmp1.1, label %if.then, label %if.end.1

cleanup:
  %retval.0 = phi i32 [ %conv, %if.then ], [ -128, %if.end.6 ]
  ret i32 %retval.0

if.end.1:
  %add.1 = add nsw i32 %add.i, %sub.add
  %cmp4.1 = icmp sgt i32 %add.1, 1050010
  %sub.1 = add nsw i32 %add.1, -1050011
  %sub.add.1 = select i1 %cmp4.1, i32 %sub.1, i32 %add.1
  %idxprom.2 = sext i32 %sub.add.1 to i64
  %arrayidx.2 = getelementptr inbounds i32, i32* %8, i64 %idxprom.2
  %13 = load i32, i32* %arrayidx.2, align 4
  %cmp1.2 = icmp eq i32 %13, %conv18.i
  br i1 %cmp1.2, label %if.then, label %if.end.2

if.end.2:
  %add.2 = add nsw i32 %add.i, %sub.add.1
  %cmp4.2 = icmp sgt i32 %add.2, 1050010
  %sub.2 = add nsw i32 %add.2, -1050011
  %sub.add.2 = select i1 %cmp4.2, i32 %sub.2, i32 %add.2
  %idxprom.3 = sext i32 %sub.add.2 to i64
  %arrayidx.3 = getelementptr inbounds i32, i32* %8, i64 %idxprom.3
  %14 = load i32, i32* %arrayidx.3, align 4
  %cmp1.3 = icmp eq i32 %14, %conv18.i
  br i1 %cmp1.3, label %if.then, label %if.end.3

if.end.3:
  %add.3 = add nsw i32 %add.i, %sub.add.2
  %cmp4.3 = icmp sgt i32 %add.3, 1050010
  %sub.3 = add nsw i32 %add.3, -1050011
  %sub.add.3 = select i1 %cmp4.3, i32 %sub.3, i32 %add.3
  %idxprom.4 = sext i32 %sub.add.3 to i64
  %arrayidx.4 = getelementptr inbounds i32, i32* %8, i64 %idxprom.4
  %15 = load i32, i32* %arrayidx.4, align 4
  %cmp1.4 = icmp eq i32 %15, %conv18.i
  br i1 %cmp1.4, label %if.then, label %if.end.4

if.end.4:
  %add.4 = add nsw i32 %add.i, %sub.add.3
  %cmp4.4 = icmp sgt i32 %add.4, 1050010
  %sub.4 = add nsw i32 %add.4, -1050011
  %sub.add.4 = select i1 %cmp4.4, i32 %sub.4, i32 %add.4
  %idxprom.5 = sext i32 %sub.add.4 to i64
  %arrayidx.5 = getelementptr inbounds i32, i32* %8, i64 %idxprom.5
  %16 = load i32, i32* %arrayidx.5, align 4
  %cmp1.5 = icmp eq i32 %16, %conv18.i
  br i1 %cmp1.5, label %if.then, label %if.end.5

if.end.5:
  %add.5 = add nsw i32 %add.i, %sub.add.4
  %cmp4.5 = icmp sgt i32 %add.5, 1050010
  %sub.5 = add nsw i32 %add.5, -1050011
  %sub.add.5 = select i1 %cmp4.5, i32 %sub.5, i32 %add.5
  %idxprom.6 = sext i32 %sub.add.5 to i64
  %arrayidx.6 = getelementptr inbounds i32, i32* %8, i64 %idxprom.6
  %17 = load i32, i32* %arrayidx.6, align 4
  %cmp1.6 = icmp eq i32 %17, %conv18.i
  br i1 %cmp1.6, label %if.then, label %if.end.6

if.end.6:
  %add.6 = add nsw i32 %add.i, %sub.add.5
  %cmp4.6 = icmp sgt i32 %add.6, 1050010
  %sub.6 = add nsw i32 %add.6, -1050011
  %sub.add.6 = select i1 %cmp4.6, i32 %sub.6, i32 %add.6
  %idxprom.7 = sext i32 %sub.add.6 to i64
  %arrayidx.7 = getelementptr inbounds i32, i32* %8, i64 %idxprom.7
  %18 = load i32, i32* %arrayidx.7, align 4
  %cmp1.7 = icmp eq i32 %18, %conv18.i
  br i1 %cmp1.7, label %if.then, label %cleanup
}