MachineFunction.cpp revision 199989 
1//===-- MachineFunction.cpp -----------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Collect native machine code information for a function.  This allows
11// target-specific information about the generated code to be stored with each
12// function.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/DerivedTypes.h"
17#include "llvm/Function.h"
18#include "llvm/Instructions.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/Config/config.h"
21#include "llvm/CodeGen/MachineConstantPool.h"
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/CodeGen/MachineFunctionPass.h"
24#include "llvm/CodeGen/MachineFrameInfo.h"
25#include "llvm/CodeGen/MachineInstr.h"
26#include "llvm/CodeGen/MachineJumpTableInfo.h"
27#include "llvm/CodeGen/MachineRegisterInfo.h"
28#include "llvm/CodeGen/Passes.h"
29#include "llvm/Target/TargetData.h"
30#include "llvm/Target/TargetLowering.h"
31#include "llvm/Target/TargetMachine.h"
32#include "llvm/Target/TargetFrameInfo.h"
33#include "llvm/Support/GraphWriter.h"
34#include "llvm/Support/raw_ostream.h"
35using namespace llvm;
36
37namespace {
38  struct Printer : public MachineFunctionPass {
39    static char ID;
40
41    raw_ostream &OS;
42    const std::string Banner;
43
44    Printer(raw_ostream &os, const std::string &banner)
45      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
46
47    const char *getPassName() const { return "MachineFunction Printer"; }
48
49    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
50      AU.setPreservesAll();
51      MachineFunctionPass::getAnalysisUsage(AU);
52    }
53
54    bool runOnMachineFunction(MachineFunction &MF) {
55      OS << "# " << Banner << ":\n";
56      MF.print(OS);
57      return false;
58    }
59  };
60  char Printer::ID = 0;
61}
62
63/// Returns a newly-created MachineFunction Printer pass. The default banner is
64/// empty.
65///
66FunctionPass *llvm::createMachineFunctionPrinterPass(raw_ostream &OS,
67                                                     const std::string &Banner){
68  return new Printer(OS, Banner);
69}
70
71//===---------------------------------------------------------------------===//
72// MachineFunction implementation
73//===---------------------------------------------------------------------===//
74
75// Out of line virtual method.
76MachineFunctionInfo::~MachineFunctionInfo() {}
77
78void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
79  MBB->getParent()->DeleteMachineBasicBlock(MBB);
80}
81
82MachineFunction::MachineFunction(Function *F,
83                                 const TargetMachine &TM)
84  : Fn(F), Target(TM) {
85  if (TM.getRegisterInfo())
86    RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
87                  MachineRegisterInfo(*TM.getRegisterInfo());
88  else
89    RegInfo = 0;
90  MFInfo = 0;
91  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
92                  MachineFrameInfo(*TM.getFrameInfo());
93  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
94                     MachineConstantPool(TM.getTargetData());
95  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
96
97  // Set up jump table.
98  const TargetData &TD = *TM.getTargetData();
99  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
100  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
101  unsigned TyAlignment = IsPic ?
102                       TD.getABITypeAlignment(Type::getInt32Ty(F->getContext()))
103                               : TD.getPointerABIAlignment();
104  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
105                      MachineJumpTableInfo(EntrySize, TyAlignment);
106}
107
108MachineFunction::~MachineFunction() {
109  BasicBlocks.clear();
110  InstructionRecycler.clear(Allocator);
111  BasicBlockRecycler.clear(Allocator);
112  if (RegInfo) {
113    RegInfo->~MachineRegisterInfo();
114    Allocator.Deallocate(RegInfo);
115  }
116  if (MFInfo) {
117    MFInfo->~MachineFunctionInfo();
118    Allocator.Deallocate(MFInfo);
119  }
120  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
121  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
122  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
123}
124
125
126/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
127/// recomputes them.  This guarantees that the MBB numbers are sequential,
128/// dense, and match the ordering of the blocks within the function.  If a
129/// specific MachineBasicBlock is specified, only that block and those after
130/// it are renumbered.
131void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
132  if (empty()) { MBBNumbering.clear(); return; }
133  MachineFunction::iterator MBBI, E = end();
134  if (MBB == 0)
135    MBBI = begin();
136  else
137    MBBI = MBB;
138
139  // Figure out the block number this should have.
140  unsigned BlockNo = 0;
141  if (MBBI != begin())
142    BlockNo = prior(MBBI)->getNumber()+1;
143
144  for (; MBBI != E; ++MBBI, ++BlockNo) {
145    if (MBBI->getNumber() != (int)BlockNo) {
146      // Remove use of the old number.
147      if (MBBI->getNumber() != -1) {
148        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
149               "MBB number mismatch!");
150        MBBNumbering[MBBI->getNumber()] = 0;
151      }
152
153      // If BlockNo is already taken, set that block's number to -1.
154      if (MBBNumbering[BlockNo])
155        MBBNumbering[BlockNo]->setNumber(-1);
156
157      MBBNumbering[BlockNo] = MBBI;
158      MBBI->setNumber(BlockNo);
159    }
160  }
161
162  // Okay, all the blocks are renumbered.  If we have compactified the block
163  // numbering, shrink MBBNumbering now.
164  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
165  MBBNumbering.resize(BlockNo);
166}
167
168/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
169/// of `new MachineInstr'.
170///
171MachineInstr *
172MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
173                                    DebugLoc DL, bool NoImp) {
174  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
175    MachineInstr(TID, DL, NoImp);
176}
177
178/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
179/// 'Orig' instruction, identical in all ways except the the instruction
180/// has no parent, prev, or next.
181///
182MachineInstr *
183MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
184  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
185             MachineInstr(*this, *Orig);
186}
187
188/// DeleteMachineInstr - Delete the given MachineInstr.
189///
190void
191MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
192  MI->~MachineInstr();
193  InstructionRecycler.Deallocate(Allocator, MI);
194}
195
196/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
197/// instead of `new MachineBasicBlock'.
198///
199MachineBasicBlock *
200MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
201  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
202             MachineBasicBlock(*this, bb);
203}
204
205/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
206///
207void
208MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
209  assert(MBB->getParent() == this && "MBB parent mismatch!");
210  MBB->~MachineBasicBlock();
211  BasicBlockRecycler.Deallocate(Allocator, MBB);
212}
213
214MachineMemOperand *
215MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
216                                      int64_t o, uint64_t s,
217                                      unsigned base_alignment) {
218  return new (Allocator.Allocate<MachineMemOperand>())
219             MachineMemOperand(v, f, o, s, base_alignment);
220}
221
222MachineMemOperand *
223MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
224                                      int64_t Offset, uint64_t Size) {
225  return new (Allocator.Allocate<MachineMemOperand>())
226             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
227                               int64_t(uint64_t(MMO->getOffset()) +
228                                       uint64_t(Offset)),
229                               Size, MMO->getBaseAlignment());
230}
231
232MachineInstr::mmo_iterator
233MachineFunction::allocateMemRefsArray(unsigned long Num) {
234  return Allocator.Allocate<MachineMemOperand *>(Num);
235}
236
237std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
238MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
239                                    MachineInstr::mmo_iterator End) {
240  // Count the number of load mem refs.
241  unsigned Num = 0;
242  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
243    if ((*I)->isLoad())
244      ++Num;
245
246  // Allocate a new array and populate it with the load information.
247  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
248  unsigned Index = 0;
249  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
250    if ((*I)->isLoad()) {
251      if (!(*I)->isStore())
252        // Reuse the MMO.
253        Result[Index] = *I;
254      else {
255        // Clone the MMO and unset the store flag.
256        MachineMemOperand *JustLoad =
257          getMachineMemOperand((*I)->getValue(),
258                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
259                               (*I)->getOffset(), (*I)->getSize(),
260                               (*I)->getBaseAlignment());
261        Result[Index] = JustLoad;
262      }
263      ++Index;
264    }
265  }
266  return std::make_pair(Result, Result + Num);
267}
268
269std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
270MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
271                                     MachineInstr::mmo_iterator End) {
272  // Count the number of load mem refs.
273  unsigned Num = 0;
274  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
275    if ((*I)->isStore())
276      ++Num;
277
278  // Allocate a new array and populate it with the store information.
279  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
280  unsigned Index = 0;
281  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
282    if ((*I)->isStore()) {
283      if (!(*I)->isLoad())
284        // Reuse the MMO.
285        Result[Index] = *I;
286      else {
287        // Clone the MMO and unset the load flag.
288        MachineMemOperand *JustStore =
289          getMachineMemOperand((*I)->getValue(),
290                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
291                               (*I)->getOffset(), (*I)->getSize(),
292                               (*I)->getBaseAlignment());
293        Result[Index] = JustStore;
294      }
295      ++Index;
296    }
297  }
298  return std::make_pair(Result, Result + Num);
299}
300
301void MachineFunction::dump() const {
302  print(errs());
303}
304
305void MachineFunction::print(raw_ostream &OS) const {
306  OS << "# Machine code for function " << Fn->getName() << ":\n";
307
308  // Print Frame Information
309  FrameInfo->print(*this, OS);
310
311  // Print JumpTable Information
312  JumpTableInfo->print(OS);
313
314  // Print Constant Pool
315  ConstantPool->print(OS);
316
317  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
318
319  if (RegInfo && !RegInfo->livein_empty()) {
320    OS << "Function Live Ins: ";
321    for (MachineRegisterInfo::livein_iterator
322         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
323      if (TRI)
324        OS << "%" << TRI->getName(I->first);
325      else
326        OS << " %physreg" << I->first;
327
328      if (I->second)
329        OS << " in reg%" << I->second;
330
331      if (next(I) != E)
332        OS << ", ";
333    }
334    OS << '\n';
335  }
336  if (RegInfo && !RegInfo->liveout_empty()) {
337    OS << "Function Live Outs: ";
338    for (MachineRegisterInfo::liveout_iterator
339         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){
340      if (TRI)
341        OS << '%' << TRI->getName(*I);
342      else
343        OS << "%physreg" << *I;
344
345      if (next(I) != E)
346        OS << " ";
347    }
348    OS << '\n';
349  }
350
351  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
352    OS << '\n';
353    BB->print(OS);
354  }
355
356  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
357}
358
359namespace llvm {
360  template<>
361  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
362
363  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
364
365    static std::string getGraphName(const MachineFunction *F) {
366      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
367    }
368
369    std::string getNodeLabel(const MachineBasicBlock *Node,
370                             const MachineFunction *Graph) {
371      if (isSimple () && Node->getBasicBlock() &&
372          !Node->getBasicBlock()->getName().empty())
373        return Node->getBasicBlock()->getNameStr() + ":";
374
375      std::string OutStr;
376      {
377        raw_string_ostream OSS(OutStr);
378
379        if (isSimple())
380          OSS << Node->getNumber() << ':';
381        else
382          Node->print(OSS);
383      }
384
385      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
386
387      // Process string output to make it nicer...
388      for (unsigned i = 0; i != OutStr.length(); ++i)
389        if (OutStr[i] == '\n') {                            // Left justify
390          OutStr[i] = '\\';
391          OutStr.insert(OutStr.begin()+i+1, 'l');
392        }
393      return OutStr;
394    }
395  };
396}
397
398void MachineFunction::viewCFG() const
399{
400#ifndef NDEBUG
401  ViewGraph(this, "mf" + getFunction()->getNameStr());
402#else
403  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
404         << "systems with Graphviz or gv!\n";
405#endif // NDEBUG
406}
407
408void MachineFunction::viewCFGOnly() const
409{
410#ifndef NDEBUG
411  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
412#else
413  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
414         << "systems with Graphviz or gv!\n";
415#endif // NDEBUG
416}
417
418/// addLiveIn - Add the specified physical register as a live-in value and
419/// create a corresponding virtual register for it.
420unsigned MachineFunction::addLiveIn(unsigned PReg,
421                                    const TargetRegisterClass *RC) {
422  assert(RC->contains(PReg) && "Not the correct regclass!");
423  unsigned VReg = getRegInfo().createVirtualRegister(RC);
424  getRegInfo().addLiveIn(PReg, VReg);
425  return VReg;
426}
427
428/// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object.
429DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const {
430  unsigned Idx = DL.getIndex();
431  assert(Idx < DebugLocInfo.DebugLocations.size() &&
432         "Invalid index into debug locations!");
433  return DebugLocInfo.DebugLocations[Idx];
434}
435
436//===----------------------------------------------------------------------===//
437//  MachineFrameInfo implementation
438//===----------------------------------------------------------------------===//
439
440/// CreateFixedObject - Create a new object at a fixed location on the stack.
441/// All fixed objects should be created before other objects are created for
442/// efficiency. By default, fixed objects are immutable. This returns an
443/// index with a negative value.
444///
445int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
446                                        bool Immutable, bool isSS) {
447  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
448  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable,
449                                              isSS));
450  return -++NumFixedObjects;
451}
452
453
454BitVector
455MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
456  assert(MBB && "MBB must be valid");
457  const MachineFunction *MF = MBB->getParent();
458  assert(MF && "MBB must be part of a MachineFunction");
459  const TargetMachine &TM = MF->getTarget();
460  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
461  BitVector BV(TRI->getNumRegs());
462
463  // Before CSI is calculated, no registers are considered pristine. They can be
464  // freely used and PEI will make sure they are saved.
465  if (!isCalleeSavedInfoValid())
466    return BV;
467
468  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
469    BV.set(*CSR);
470
471  // The entry MBB always has all CSRs pristine.
472  if (MBB == &MF->front())
473    return BV;
474
475  // On other MBBs the saved CSRs are not pristine.
476  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
477  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
478         E = CSI.end(); I != E; ++I)
479    BV.reset(I->getReg());
480
481  return BV;
482}
483
484
485void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
486  if (Objects.empty()) return;
487
488  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
489  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
490
491  OS << "Frame Objects:\n";
492
493  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
494    const StackObject &SO = Objects[i];
495    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
496    if (SO.Size == ~0ULL) {
497      OS << "dead\n";
498      continue;
499    }
500    if (SO.Size == 0)
501      OS << "variable sized";
502    else
503      OS << "size=" << SO.Size;
504    OS << ", align=" << SO.Alignment;
505
506    if (i < NumFixedObjects)
507      OS << ", fixed";
508    if (i < NumFixedObjects || SO.SPOffset != -1) {
509      int64_t Off = SO.SPOffset - ValOffset;
510      OS << ", at location [SP";
511      if (Off > 0)
512        OS << "+" << Off;
513      else if (Off < 0)
514        OS << Off;
515      OS << "]";
516    }
517    OS << "\n";
518  }
519}
520
521void MachineFrameInfo::dump(const MachineFunction &MF) const {
522  print(MF, errs());
523}
524
525//===----------------------------------------------------------------------===//
526//  MachineJumpTableInfo implementation
527//===----------------------------------------------------------------------===//
528
529/// getJumpTableIndex - Create a new jump table entry in the jump table info
530/// or return an existing one.
531///
532unsigned MachineJumpTableInfo::getJumpTableIndex(
533                               const std::vector<MachineBasicBlock*> &DestBBs) {
534  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
535  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
536  return JumpTables.size()-1;
537}
538
539/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
540/// the jump tables to branch to New instead.
541bool
542MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
543                                             MachineBasicBlock *New) {
544  assert(Old != New && "Not making a change?");
545  bool MadeChange = false;
546  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
547    ReplaceMBBInJumpTable(i, Old, New);
548  return MadeChange;
549}
550
551/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
552/// the jump table to branch to New instead.
553bool
554MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
555                                            MachineBasicBlock *Old,
556                                            MachineBasicBlock *New) {
557  assert(Old != New && "Not making a change?");
558  bool MadeChange = false;
559  MachineJumpTableEntry &JTE = JumpTables[Idx];
560  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
561    if (JTE.MBBs[j] == Old) {
562      JTE.MBBs[j] = New;
563      MadeChange = true;
564    }
565  return MadeChange;
566}
567
568void MachineJumpTableInfo::print(raw_ostream &OS) const {
569  if (JumpTables.empty()) return;
570
571  OS << "Jump Tables:\n";
572
573  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
574    OS << "  jt#" << i << ": ";
575    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
576      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
577  }
578
579  OS << '\n';
580}
581
582void MachineJumpTableInfo::dump() const { print(errs()); }
583
584
585//===----------------------------------------------------------------------===//
586//  MachineConstantPool implementation
587//===----------------------------------------------------------------------===//
588
589const Type *MachineConstantPoolEntry::getType() const {
590  if (isMachineConstantPoolEntry())
591    return Val.MachineCPVal->getType();
592  return Val.ConstVal->getType();
593}
594
595
596unsigned MachineConstantPoolEntry::getRelocationInfo() const {
597  if (isMachineConstantPoolEntry())
598    return Val.MachineCPVal->getRelocationInfo();
599  return Val.ConstVal->getRelocationInfo();
600}
601
602MachineConstantPool::~MachineConstantPool() {
603  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
604    if (Constants[i].isMachineConstantPoolEntry())
605      delete Constants[i].Val.MachineCPVal;
606}
607
608/// CanShareConstantPoolEntry - Test whether the given two constants
609/// can be allocated the same constant pool entry.
610static bool CanShareConstantPoolEntry(Constant *A, Constant *B,
611                                      const TargetData *TD) {
612  // Handle the trivial case quickly.
613  if (A == B) return true;
614
615  // If they have the same type but weren't the same constant, quickly
616  // reject them.
617  if (A->getType() == B->getType()) return false;
618
619  // For now, only support constants with the same size.
620  if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
621    return false;
622
623  // If a floating-point value and an integer value have the same encoding,
624  // they can share a constant-pool entry.
625  if (ConstantFP *AFP = dyn_cast<ConstantFP>(A))
626    if (ConstantInt *BI = dyn_cast<ConstantInt>(B))
627      return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
628  if (ConstantFP *BFP = dyn_cast<ConstantFP>(B))
629    if (ConstantInt *AI = dyn_cast<ConstantInt>(A))
630      return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
631
632  // Two vectors can share an entry if each pair of corresponding
633  // elements could.
634  if (ConstantVector *AV = dyn_cast<ConstantVector>(A))
635    if (ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
636      if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
637        return false;
638      for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
639        if (!CanShareConstantPoolEntry(AV->getOperand(i),
640                                       BV->getOperand(i), TD))
641          return false;
642      return true;
643    }
644
645  // TODO: Handle other cases.
646
647  return false;
648}
649
650/// getConstantPoolIndex - Create a new entry in the constant pool or return
651/// an existing one.  User must specify the log2 of the minimum required
652/// alignment for the object.
653///
654unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
655                                                   unsigned Alignment) {
656  assert(Alignment && "Alignment must be specified!");
657  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
658
659  // Check to see if we already have this constant.
660  //
661  // FIXME, this could be made much more efficient for large constant pools.
662  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
663    if (!Constants[i].isMachineConstantPoolEntry() &&
664        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
665      if ((unsigned)Constants[i].getAlignment() < Alignment)
666        Constants[i].Alignment = Alignment;
667      return i;
668    }
669
670  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
671  return Constants.size()-1;
672}
673
674unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
675                                                   unsigned Alignment) {
676  assert(Alignment && "Alignment must be specified!");
677  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
678
679  // Check to see if we already have this constant.
680  //
681  // FIXME, this could be made much more efficient for large constant pools.
682  int Idx = V->getExistingMachineCPValue(this, Alignment);
683  if (Idx != -1)
684    return (unsigned)Idx;
685
686  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
687  return Constants.size()-1;
688}
689
690void MachineConstantPool::print(raw_ostream &OS) const {
691  if (Constants.empty()) return;
692
693  OS << "Constant Pool:\n";
694  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
695    OS << "  cp#" << i << ": ";
696    if (Constants[i].isMachineConstantPoolEntry())
697      Constants[i].Val.MachineCPVal->print(OS);
698    else
699      OS << *(Value*)Constants[i].Val.ConstVal;
700    OS << ", align=" << Constants[i].getAlignment();
701    OS << "\n";
702  }
703}
704
705void MachineConstantPool::dump() const { print(errs()); }
706