summaryrefslogtreecommitdiffstats
path: root/contrib/llvm/lib/CodeGen/MachineFunction.cpp
blob: 6b4cba6c678285ccbb903a463a7d8519cfed7ddc (plain)
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
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
//===-- MachineFunction.cpp -----------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Collect native machine code information for a function.  This allows
// target-specific information about the generated code to be stored with each
// function.
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GraphWriter.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;

#define DEBUG_TYPE "codegen"

//===----------------------------------------------------------------------===//
// MachineFunction implementation
//===----------------------------------------------------------------------===//

// Out of line virtual method.
MachineFunctionInfo::~MachineFunctionInfo() {}

void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
  MBB->getParent()->DeleteMachineBasicBlock(MBB);
}

MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
                                 unsigned FunctionNum, MachineModuleInfo &mmi)
    : Fn(F), Target(TM), STI(TM.getSubtargetImpl()), Ctx(mmi.getContext()),
      MMI(mmi) {
  if (STI->getRegisterInfo())
    RegInfo = new (Allocator) MachineRegisterInfo(this);
  else
    RegInfo = nullptr;

  MFInfo = nullptr;
  FrameInfo = new (Allocator)
      MachineFrameInfo(STI->getFrameLowering()->getStackAlignment(),
                       STI->getFrameLowering()->isStackRealignable(),
                       !F->hasFnAttribute("no-realign-stack"));

  if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                       Attribute::StackAlignment))
    FrameInfo->ensureMaxAlignment(Fn->getAttributes().
                                getStackAlignment(AttributeSet::FunctionIndex));

  ConstantPool = new (Allocator) MachineConstantPool(TM);
  Alignment = STI->getTargetLowering()->getMinFunctionAlignment();

  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
  if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
                                        Attribute::OptimizeForSize))
    Alignment = std::max(Alignment,
                         STI->getTargetLowering()->getPrefFunctionAlignment());

  FunctionNumber = FunctionNum;
  JumpTableInfo = nullptr;
}

MachineFunction::~MachineFunction() {
  // Don't call destructors on MachineInstr and MachineOperand. All of their
  // memory comes from the BumpPtrAllocator which is about to be purged.
  //
  // Do call MachineBasicBlock destructors, it contains std::vectors.
  for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
    I->Insts.clearAndLeakNodesUnsafely();

  InstructionRecycler.clear(Allocator);
  OperandRecycler.clear(Allocator);
  BasicBlockRecycler.clear(Allocator);
  if (RegInfo) {
    RegInfo->~MachineRegisterInfo();
    Allocator.Deallocate(RegInfo);
  }
  if (MFInfo) {
    MFInfo->~MachineFunctionInfo();
    Allocator.Deallocate(MFInfo);
  }

  FrameInfo->~MachineFrameInfo();
  Allocator.Deallocate(FrameInfo);

  ConstantPool->~MachineConstantPool();
  Allocator.Deallocate(ConstantPool);

  if (JumpTableInfo) {
    JumpTableInfo->~MachineJumpTableInfo();
    Allocator.Deallocate(JumpTableInfo);
  }
}

/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
/// does already exist, allocate one.
MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind) {
  if (JumpTableInfo) return JumpTableInfo;

  JumpTableInfo = new (Allocator)
    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
  return JumpTableInfo;
}

/// Should we be emitting segmented stack stuff for the function
bool MachineFunction::shouldSplitStack() {
  return getFunction()->hasFnAttribute("split-stack");
}

/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
/// recomputes them.  This guarantees that the MBB numbers are sequential,
/// dense, and match the ordering of the blocks within the function.  If a
/// specific MachineBasicBlock is specified, only that block and those after
/// it are renumbered.
void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
  if (empty()) { MBBNumbering.clear(); return; }
  MachineFunction::iterator MBBI, E = end();
  if (MBB == nullptr)
    MBBI = begin();
  else
    MBBI = MBB;

  // Figure out the block number this should have.
  unsigned BlockNo = 0;
  if (MBBI != begin())
    BlockNo = std::prev(MBBI)->getNumber() + 1;

  for (; MBBI != E; ++MBBI, ++BlockNo) {
    if (MBBI->getNumber() != (int)BlockNo) {
      // Remove use of the old number.
      if (MBBI->getNumber() != -1) {
        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
               "MBB number mismatch!");
        MBBNumbering[MBBI->getNumber()] = nullptr;
      }

      // If BlockNo is already taken, set that block's number to -1.
      if (MBBNumbering[BlockNo])
        MBBNumbering[BlockNo]->setNumber(-1);

      MBBNumbering[BlockNo] = MBBI;
      MBBI->setNumber(BlockNo);
    }
  }

  // Okay, all the blocks are renumbered.  If we have compactified the block
  // numbering, shrink MBBNumbering now.
  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
  MBBNumbering.resize(BlockNo);
}

/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
/// of `new MachineInstr'.
///
MachineInstr *
MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
                                    DebugLoc DL, bool NoImp) {
  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
    MachineInstr(*this, MCID, DL, NoImp);
}

/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
/// 'Orig' instruction, identical in all ways except the instruction
/// has no parent, prev, or next.
///
MachineInstr *
MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
             MachineInstr(*this, *Orig);
}

/// DeleteMachineInstr - Delete the given MachineInstr.
///
/// This function also serves as the MachineInstr destructor - the real
/// ~MachineInstr() destructor must be empty.
void
MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
  // Strip it for parts. The operand array and the MI object itself are
  // independently recyclable.
  if (MI->Operands)
    deallocateOperandArray(MI->CapOperands, MI->Operands);
  // Don't call ~MachineInstr() which must be trivial anyway because
  // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
  // destructors.
  InstructionRecycler.Deallocate(Allocator, MI);
}

/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
/// instead of `new MachineBasicBlock'.
///
MachineBasicBlock *
MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
             MachineBasicBlock(*this, bb);
}

/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
///
void
MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
  assert(MBB->getParent() == this && "MBB parent mismatch!");
  MBB->~MachineBasicBlock();
  BasicBlockRecycler.Deallocate(Allocator, MBB);
}

MachineMemOperand *
MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
                                      uint64_t s, unsigned base_alignment,
                                      const AAMDNodes &AAInfo,
                                      const MDNode *Ranges) {
  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
                                           AAInfo, Ranges);
}

MachineMemOperand *
MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
                                      int64_t Offset, uint64_t Size) {
  if (MMO->getValue())
    return new (Allocator)
               MachineMemOperand(MachinePointerInfo(MMO->getValue(),
                                                    MMO->getOffset()+Offset),
                                 MMO->getFlags(), Size,
                                 MMO->getBaseAlignment());
  return new (Allocator)
             MachineMemOperand(MachinePointerInfo(MMO->getPseudoValue(),
                                                  MMO->getOffset()+Offset),
                               MMO->getFlags(), Size,
                               MMO->getBaseAlignment());
}

MachineInstr::mmo_iterator
MachineFunction::allocateMemRefsArray(unsigned long Num) {
  return Allocator.Allocate<MachineMemOperand *>(Num);
}

std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
                                    MachineInstr::mmo_iterator End) {
  // Count the number of load mem refs.
  unsigned Num = 0;
  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
    if ((*I)->isLoad())
      ++Num;

  // Allocate a new array and populate it with the load information.
  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
  unsigned Index = 0;
  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
    if ((*I)->isLoad()) {
      if (!(*I)->isStore())
        // Reuse the MMO.
        Result[Index] = *I;
      else {
        // Clone the MMO and unset the store flag.
        MachineMemOperand *JustLoad =
          getMachineMemOperand((*I)->getPointerInfo(),
                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
                               (*I)->getSize(), (*I)->getBaseAlignment(),
                               (*I)->getAAInfo());
        Result[Index] = JustLoad;
      }
      ++Index;
    }
  }
  return std::make_pair(Result, Result + Num);
}

std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
                                     MachineInstr::mmo_iterator End) {
  // Count the number of load mem refs.
  unsigned Num = 0;
  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
    if ((*I)->isStore())
      ++Num;

  // Allocate a new array and populate it with the store information.
  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
  unsigned Index = 0;
  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
    if ((*I)->isStore()) {
      if (!(*I)->isLoad())
        // Reuse the MMO.
        Result[Index] = *I;
      else {
        // Clone the MMO and unset the load flag.
        MachineMemOperand *JustStore =
          getMachineMemOperand((*I)->getPointerInfo(),
                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
                               (*I)->getSize(), (*I)->getBaseAlignment(),
                               (*I)->getAAInfo());
        Result[Index] = JustStore;
      }
      ++Index;
    }
  }
  return std::make_pair(Result, Result + Num);
}

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineFunction::dump() const {
  print(dbgs());
}
#endif

StringRef MachineFunction::getName() const {
  assert(getFunction() && "No function!");
  return getFunction()->getName();
}

void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
  OS << "# Machine code for function " << getName() << ": ";
  if (RegInfo) {
    OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
    if (!RegInfo->tracksLiveness())
      OS << ", not tracking liveness";
  }
  OS << '\n';

  // Print Frame Information
  FrameInfo->print(*this, OS);

  // Print JumpTable Information
  if (JumpTableInfo)
    JumpTableInfo->print(OS);

  // Print Constant Pool
  ConstantPool->print(OS);

  const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo();

  if (RegInfo && !RegInfo->livein_empty()) {
    OS << "Function Live Ins: ";
    for (MachineRegisterInfo::livein_iterator
         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
      OS << PrintReg(I->first, TRI);
      if (I->second)
        OS << " in " << PrintReg(I->second, TRI);
      if (std::next(I) != E)
        OS << ", ";
    }
    OS << '\n';
  }

  for (const auto &BB : *this) {
    OS << '\n';
    BB.print(OS, Indexes);
  }

  OS << "\n# End machine code for function " << getName() << ".\n\n";
}

namespace llvm {
  template<>
  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {

  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}

    static std::string getGraphName(const MachineFunction *F) {
      return "CFG for '" + F->getName().str() + "' function";
    }

    std::string getNodeLabel(const MachineBasicBlock *Node,
                             const MachineFunction *Graph) {
      std::string OutStr;
      {
        raw_string_ostream OSS(OutStr);

        if (isSimple()) {
          OSS << "BB#" << Node->getNumber();
          if (const BasicBlock *BB = Node->getBasicBlock())
            OSS << ": " << BB->getName();
        } else
          Node->print(OSS);
      }

      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());

      // Process string output to make it nicer...
      for (unsigned i = 0; i != OutStr.length(); ++i)
        if (OutStr[i] == '\n') {                            // Left justify
          OutStr[i] = '\\';
          OutStr.insert(OutStr.begin()+i+1, 'l');
        }
      return OutStr;
    }
  };
}

void MachineFunction::viewCFG() const
{
#ifndef NDEBUG
  ViewGraph(this, "mf" + getName());
#else
  errs() << "MachineFunction::viewCFG is only available in debug builds on "
         << "systems with Graphviz or gv!\n";
#endif // NDEBUG
}

void MachineFunction::viewCFGOnly() const
{
#ifndef NDEBUG
  ViewGraph(this, "mf" + getName(), true);
#else
  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
         << "systems with Graphviz or gv!\n";
#endif // NDEBUG
}

/// addLiveIn - Add the specified physical register as a live-in value and
/// create a corresponding virtual register for it.
unsigned MachineFunction::addLiveIn(unsigned PReg,
                                    const TargetRegisterClass *RC) {
  MachineRegisterInfo &MRI = getRegInfo();
  unsigned VReg = MRI.getLiveInVirtReg(PReg);
  if (VReg) {
    const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
    (void)VRegRC;
    // A physical register can be added several times.
    // Between two calls, the register class of the related virtual register
    // may have been constrained to match some operation constraints.
    // In that case, check that the current register class includes the
    // physical register and is a sub class of the specified RC.
    assert((VRegRC == RC || (VRegRC->contains(PReg) &&
                             RC->hasSubClassEq(VRegRC))) &&
            "Register class mismatch!");
    return VReg;
  }
  VReg = MRI.createVirtualRegister(RC);
  MRI.addLiveIn(PReg, VReg);
  return VReg;
}

/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
/// normal 'L' label is returned.
MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
                                        bool isLinkerPrivate) const {
  const DataLayout *DL = getSubtarget().getDataLayout();
  assert(JumpTableInfo && "No jump tables");
  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");

  const char *Prefix = isLinkerPrivate ? DL->getLinkerPrivateGlobalPrefix() :
                                         DL->getPrivateGlobalPrefix();
  SmallString<60> Name;
  raw_svector_ostream(Name)
    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
  return Ctx.GetOrCreateSymbol(Name.str());
}

/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
/// base.
MCSymbol *MachineFunction::getPICBaseSymbol() const {
  const DataLayout *DL = getSubtarget().getDataLayout();
  return Ctx.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
                               Twine(getFunctionNumber())+"$pb");
}

//===----------------------------------------------------------------------===//
//  MachineFrameInfo implementation
//===----------------------------------------------------------------------===//

/// ensureMaxAlignment - Make sure the function is at least Align bytes
/// aligned.
void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
  if (!StackRealignable || !RealignOption)
    assert(Align <= StackAlignment &&
           "For targets without stack realignment, Align is out of limit!");
  if (MaxAlignment < Align) MaxAlignment = Align;
}

/// clampStackAlignment - Clamp the alignment if requested and emit a warning.
static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
                                           unsigned StackAlign) {
  if (!ShouldClamp || Align <= StackAlign)
    return Align;
  DEBUG(dbgs() << "Warning: requested alignment " << Align
               << " exceeds the stack alignment " << StackAlign
               << " when stack realignment is off" << '\n');
  return StackAlign;
}

/// CreateStackObject - Create a new statically sized stack object, returning
/// a nonnegative identifier to represent it.
///
int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
                      bool isSS, const AllocaInst *Alloca) {
  assert(Size != 0 && "Cannot allocate zero size stack objects!");
  Alignment = clampStackAlignment(!StackRealignable || !RealignOption,
                                  Alignment, StackAlignment);
  Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, Alloca,
                                !isSS));
  int Index = (int)Objects.size() - NumFixedObjects - 1;
  assert(Index >= 0 && "Bad frame index!");
  ensureMaxAlignment(Alignment);
  return Index;
}

/// CreateSpillStackObject - Create a new statically sized stack object that
/// represents a spill slot, returning a nonnegative identifier to represent
/// it.
///
int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
                                             unsigned Alignment) {
  Alignment = clampStackAlignment(!StackRealignable || !RealignOption,
                                  Alignment, StackAlignment);
  CreateStackObject(Size, Alignment, true);
  int Index = (int)Objects.size() - NumFixedObjects - 1;
  ensureMaxAlignment(Alignment);
  return Index;
}

/// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
/// variable sized object has been created.  This must be created whenever a
/// variable sized object is created, whether or not the index returned is
/// actually used.
///
int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment,
                                                const AllocaInst *Alloca) {
  HasVarSizedObjects = true;
  Alignment = clampStackAlignment(!StackRealignable || !RealignOption,
                                  Alignment, StackAlignment);
  Objects.push_back(StackObject(0, Alignment, 0, false, false, Alloca, true));
  ensureMaxAlignment(Alignment);
  return (int)Objects.size()-NumFixedObjects-1;
}

/// CreateFixedObject - Create a new object at a fixed location on the stack.
/// All fixed objects should be created before other objects are created for
/// efficiency. By default, fixed objects are immutable. This returns an
/// index with a negative value.
///
int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
                                        bool Immutable, bool isAliased) {
  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
  // The alignment of the frame index can be determined from its offset from
  // the incoming frame position.  If the frame object is at offset 32 and
  // the stack is guaranteed to be 16-byte aligned, then we know that the
  // object is 16-byte aligned.
  unsigned Align = MinAlign(SPOffset, StackAlignment);
  Align = clampStackAlignment(!StackRealignable || !RealignOption, Align,
                              StackAlignment);
  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
                                              /*isSS*/   false,
                                              /*Alloca*/ nullptr, isAliased));
  return -++NumFixedObjects;
}

/// CreateFixedSpillStackObject - Create a spill slot at a fixed location
/// on the stack.  Returns an index with a negative value.
int MachineFrameInfo::CreateFixedSpillStackObject(uint64_t Size,
                                                  int64_t SPOffset) {
  unsigned Align = MinAlign(SPOffset, StackAlignment);
  Align = clampStackAlignment(!StackRealignable || !RealignOption, Align,
                              StackAlignment);
  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset,
                                              /*Immutable*/ true,
                                              /*isSS*/ true,
                                              /*Alloca*/ nullptr,
                                              /*isAliased*/ false));
  return -++NumFixedObjects;
}

int MachineFrameInfo::CreateFrameAllocation(uint64_t Size) {
  // Force the use of a frame pointer. The intention is that this intrinsic be
  // used in conjunction with unwind mechanisms that leak the frame pointer.
  setFrameAddressIsTaken(true);
  Size = RoundUpToAlignment(Size, StackAlignment);
  return CreateStackObject(Size, StackAlignment, false);
}

BitVector
MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
  assert(MBB && "MBB must be valid");
  const MachineFunction *MF = MBB->getParent();
  assert(MF && "MBB must be part of a MachineFunction");
  const TargetMachine &TM = MF->getTarget();
  const TargetRegisterInfo *TRI = TM.getSubtargetImpl()->getRegisterInfo();
  BitVector BV(TRI->getNumRegs());

  // Before CSI is calculated, no registers are considered pristine. They can be
  // freely used and PEI will make sure they are saved.
  if (!isCalleeSavedInfoValid())
    return BV;

  for (const MCPhysReg *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
    BV.set(*CSR);

  // The entry MBB always has all CSRs pristine.
  if (MBB == &MF->front())
    return BV;

  // On other MBBs the saved CSRs are not pristine.
  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
         E = CSI.end(); I != E; ++I)
    BV.reset(I->getReg());

  return BV;
}

unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
  const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
  unsigned MaxAlign = getMaxAlignment();
  int Offset = 0;

  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
  // It really should be refactored to share code. Until then, changes
  // should keep in mind that there's tight coupling between the two.

  for (int i = getObjectIndexBegin(); i != 0; ++i) {
    int FixedOff = -getObjectOffset(i);
    if (FixedOff > Offset) Offset = FixedOff;
  }
  for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
    if (isDeadObjectIndex(i))
      continue;
    Offset += getObjectSize(i);
    unsigned Align = getObjectAlignment(i);
    // Adjust to alignment boundary
    Offset = (Offset+Align-1)/Align*Align;

    MaxAlign = std::max(Align, MaxAlign);
  }

  if (adjustsStack() && TFI->hasReservedCallFrame(MF))
    Offset += getMaxCallFrameSize();

  // Round up the size to a multiple of the alignment.  If the function has
  // any calls or alloca's, align to the target's StackAlignment value to
  // ensure that the callee's frame or the alloca data is suitably aligned;
  // otherwise, for leaf functions, align to the TransientStackAlignment
  // value.
  unsigned StackAlign;
  if (adjustsStack() || hasVarSizedObjects() ||
      (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
    StackAlign = TFI->getStackAlignment();
  else
    StackAlign = TFI->getTransientStackAlignment();

  // If the frame pointer is eliminated, all frame offsets will be relative to
  // SP not FP. Align to MaxAlign so this works.
  StackAlign = std::max(StackAlign, MaxAlign);
  unsigned AlignMask = StackAlign - 1;
  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);

  return (unsigned)Offset;
}

void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
  if (Objects.empty()) return;

  const TargetFrameLowering *FI = MF.getSubtarget().getFrameLowering();
  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);

  OS << "Frame Objects:\n";

  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
    const StackObject &SO = Objects[i];
    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
    if (SO.Size == ~0ULL) {
      OS << "dead\n";
      continue;
    }
    if (SO.Size == 0)
      OS << "variable sized";
    else
      OS << "size=" << SO.Size;
    OS << ", align=" << SO.Alignment;

    if (i < NumFixedObjects)
      OS << ", fixed";
    if (i < NumFixedObjects || SO.SPOffset != -1) {
      int64_t Off = SO.SPOffset - ValOffset;
      OS << ", at location [SP";
      if (Off > 0)
        OS << "+" << Off;
      else if (Off < 0)
        OS << Off;
      OS << "]";
    }
    OS << "\n";
  }
}

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineFrameInfo::dump(const MachineFunction &MF) const {
  print(MF, dbgs());
}
#endif

//===----------------------------------------------------------------------===//
//  MachineJumpTableInfo implementation
//===----------------------------------------------------------------------===//

/// getEntrySize - Return the size of each entry in the jump table.
unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
  // The size of a jump table entry is 4 bytes unless the entry is just the
  // address of a block, in which case it is the pointer size.
  switch (getEntryKind()) {
  case MachineJumpTableInfo::EK_BlockAddress:
    return TD.getPointerSize();
  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
    return 8;
  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
  case MachineJumpTableInfo::EK_LabelDifference32:
  case MachineJumpTableInfo::EK_Custom32:
    return 4;
  case MachineJumpTableInfo::EK_Inline:
    return 0;
  }
  llvm_unreachable("Unknown jump table encoding!");
}

/// getEntryAlignment - Return the alignment of each entry in the jump table.
unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
  // The alignment of a jump table entry is the alignment of int32 unless the
  // entry is just the address of a block, in which case it is the pointer
  // alignment.
  switch (getEntryKind()) {
  case MachineJumpTableInfo::EK_BlockAddress:
    return TD.getPointerABIAlignment();
  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
    return TD.getABIIntegerTypeAlignment(64);
  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
  case MachineJumpTableInfo::EK_LabelDifference32:
  case MachineJumpTableInfo::EK_Custom32:
    return TD.getABIIntegerTypeAlignment(32);
  case MachineJumpTableInfo::EK_Inline:
    return 1;
  }
  llvm_unreachable("Unknown jump table encoding!");
}

/// createJumpTableIndex - Create a new jump table entry in the jump table info.
///
unsigned MachineJumpTableInfo::createJumpTableIndex(
                               const std::vector<MachineBasicBlock*> &DestBBs) {
  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
  return JumpTables.size()-1;
}

/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
/// the jump tables to branch to New instead.
bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
                                                  MachineBasicBlock *New) {
  assert(Old != New && "Not making a change?");
  bool MadeChange = false;
  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
    ReplaceMBBInJumpTable(i, Old, New);
  return MadeChange;
}

/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
/// the jump table to branch to New instead.
bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
                                                 MachineBasicBlock *Old,
                                                 MachineBasicBlock *New) {
  assert(Old != New && "Not making a change?");
  bool MadeChange = false;
  MachineJumpTableEntry &JTE = JumpTables[Idx];
  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
    if (JTE.MBBs[j] == Old) {
      JTE.MBBs[j] = New;
      MadeChange = true;
    }
  return MadeChange;
}

void MachineJumpTableInfo::print(raw_ostream &OS) const {
  if (JumpTables.empty()) return;

  OS << "Jump Tables:\n";

  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
    OS << "  jt#" << i << ": ";
    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
  }

  OS << '\n';
}

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineJumpTableInfo::dump() const { print(dbgs()); }
#endif


//===----------------------------------------------------------------------===//
//  MachineConstantPool implementation
//===----------------------------------------------------------------------===//

void MachineConstantPoolValue::anchor() { }

const DataLayout *MachineConstantPool::getDataLayout() const {
  return TM.getSubtargetImpl()->getDataLayout();
}

Type *MachineConstantPoolEntry::getType() const {
  if (isMachineConstantPoolEntry())
    return Val.MachineCPVal->getType();
  return Val.ConstVal->getType();
}


unsigned MachineConstantPoolEntry::getRelocationInfo() const {
  if (isMachineConstantPoolEntry())
    return Val.MachineCPVal->getRelocationInfo();
  return Val.ConstVal->getRelocationInfo();
}

SectionKind
MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const {
  SectionKind Kind;
  switch (getRelocationInfo()) {
  default:
    llvm_unreachable("Unknown section kind");
  case 2:
    Kind = SectionKind::getReadOnlyWithRel();
    break;
  case 1:
    Kind = SectionKind::getReadOnlyWithRelLocal();
    break;
  case 0:
    switch (DL->getTypeAllocSize(getType())) {
    case 4:
      Kind = SectionKind::getMergeableConst4();
      break;
    case 8:
      Kind = SectionKind::getMergeableConst8();
      break;
    case 16:
      Kind = SectionKind::getMergeableConst16();
      break;
    default:
      Kind = SectionKind::getMergeableConst();
      break;
    }
  }
  return Kind;
}

MachineConstantPool::~MachineConstantPool() {
  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
    if (Constants[i].isMachineConstantPoolEntry())
      delete Constants[i].Val.MachineCPVal;
  for (DenseSet<MachineConstantPoolValue*>::iterator I =
       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
       I != E; ++I)
    delete *I;
}

/// CanShareConstantPoolEntry - Test whether the given two constants
/// can be allocated the same constant pool entry.
static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
                                      const DataLayout *TD) {
  // Handle the trivial case quickly.
  if (A == B) return true;

  // If they have the same type but weren't the same constant, quickly
  // reject them.
  if (A->getType() == B->getType()) return false;

  // We can't handle structs or arrays.
  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
    return false;

  // For now, only support constants with the same size.
  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
  if (StoreSize != TD->getTypeStoreSize(B->getType()) || StoreSize > 128)
    return false;

  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);

  // Try constant folding a bitcast of both instructions to an integer.  If we
  // get two identical ConstantInt's, then we are good to share them.  We use
  // the constant folding APIs to do this so that we get the benefit of
  // DataLayout.
  if (isa<PointerType>(A->getType()))
    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
                                 const_cast<Constant*>(A), TD);
  else if (A->getType() != IntTy)
    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
                                 const_cast<Constant*>(A), TD);
  if (isa<PointerType>(B->getType()))
    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
                                 const_cast<Constant*>(B), TD);
  else if (B->getType() != IntTy)
    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
                                 const_cast<Constant*>(B), TD);

  return A == B;
}

/// getConstantPoolIndex - Create a new entry in the constant pool or return
/// an existing one.  User must specify the log2 of the minimum required
/// alignment for the object.
///
unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
                                                   unsigned Alignment) {
  assert(Alignment && "Alignment must be specified!");
  if (Alignment > PoolAlignment) PoolAlignment = Alignment;

  // Check to see if we already have this constant.
  //
  // FIXME, this could be made much more efficient for large constant pools.
  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
    if (!Constants[i].isMachineConstantPoolEntry() &&
        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
                                  getDataLayout())) {
      if ((unsigned)Constants[i].getAlignment() < Alignment)
        Constants[i].Alignment = Alignment;
      return i;
    }

  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
  return Constants.size()-1;
}

unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
                                                   unsigned Alignment) {
  assert(Alignment && "Alignment must be specified!");
  if (Alignment > PoolAlignment) PoolAlignment = Alignment;

  // Check to see if we already have this constant.
  //
  // FIXME, this could be made much more efficient for large constant pools.
  int Idx = V->getExistingMachineCPValue(this, Alignment);
  if (Idx != -1) {
    MachineCPVsSharingEntries.insert(V);
    return (unsigned)Idx;
  }

  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
  return Constants.size()-1;
}

void MachineConstantPool::print(raw_ostream &OS) const {
  if (Constants.empty()) return;

  OS << "Constant Pool:\n";
  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
    OS << "  cp#" << i << ": ";
    if (Constants[i].isMachineConstantPoolEntry())
      Constants[i].Val.MachineCPVal->print(OS);
    else
      Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
    OS << ", align=" << Constants[i].getAlignment();
    OS << "\n";
  }
}

#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MachineConstantPool::dump() const { print(dbgs()); }
#endif
OpenPOWER on IntegriCloud