MachineFunction.cpp revision 589c6f620e8dcf3d59af1ae0e15372c934647c82 
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/Config/config.h"
20#include "llvm/CodeGen/MachineConstantPool.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/CodeGen/MachineFunctionPass.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineInstr.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/Passes.h"
28#include "llvm/MC/MCAsmInfo.h"
29#include "llvm/MC/MCContext.h"
30#include "llvm/Analysis/DebugInfo.h"
31#include "llvm/Support/Debug.h"
32#include "llvm/Target/TargetData.h"
33#include "llvm/Target/TargetLowering.h"
34#include "llvm/Target/TargetMachine.h"
35#include "llvm/Target/TargetFrameInfo.h"
36#include "llvm/ADT/SmallString.h"
37#include "llvm/ADT/STLExtras.h"
38#include "llvm/Support/GraphWriter.h"
39#include "llvm/Support/raw_ostream.h"
40using namespace llvm;
41
42namespace {
43  struct Printer : public MachineFunctionPass {
44    static char ID;
45
46    raw_ostream &OS;
47    const std::string Banner;
48
49    Printer(raw_ostream &os, const std::string &banner)
50      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
51
52    const char *getPassName() const { return "MachineFunction Printer"; }
53
54    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
55      AU.setPreservesAll();
56      MachineFunctionPass::getAnalysisUsage(AU);
57    }
58
59    bool runOnMachineFunction(MachineFunction &MF) {
60      OS << "# " << Banner << ":\n";
61      MF.print(OS);
62      return false;
63    }
64  };
65  char Printer::ID = 0;
66}
67
68/// Returns a newly-created MachineFunction Printer pass. The default banner is
69/// empty.
70///
71FunctionPass *llvm::createMachineFunctionPrinterPass(raw_ostream &OS,
72                                                     const std::string &Banner){
73  return new Printer(OS, Banner);
74}
75
76//===----------------------------------------------------------------------===//
77// MachineFunction implementation
78//===----------------------------------------------------------------------===//
79
80// Out of line virtual method.
81MachineFunctionInfo::~MachineFunctionInfo() {}
82
83void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
84  MBB->getParent()->DeleteMachineBasicBlock(MBB);
85}
86
87MachineFunction::MachineFunction(Function *F, const TargetMachine &TM,
88                                 unsigned FunctionNum)
89  : Fn(F), Target(TM) {
90  if (TM.getRegisterInfo())
91    RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
92                  MachineRegisterInfo(*TM.getRegisterInfo());
93  else
94    RegInfo = 0;
95  MFInfo = 0;
96  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
97                  MachineFrameInfo(*TM.getFrameInfo());
98  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
99                     MachineConstantPool(TM.getTargetData());
100  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
101  FunctionNumber = FunctionNum;
102  JumpTableInfo = 0;
103}
104
105MachineFunction::~MachineFunction() {
106  BasicBlocks.clear();
107  InstructionRecycler.clear(Allocator);
108  BasicBlockRecycler.clear(Allocator);
109  if (RegInfo) {
110    RegInfo->~MachineRegisterInfo();
111    Allocator.Deallocate(RegInfo);
112  }
113  if (MFInfo) {
114    MFInfo->~MachineFunctionInfo();
115    Allocator.Deallocate(MFInfo);
116  }
117  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
118  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
119
120  if (JumpTableInfo) {
121    JumpTableInfo->~MachineJumpTableInfo();
122    Allocator.Deallocate(JumpTableInfo);
123  }
124}
125
126/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
127/// does already exist, allocate one.
128MachineJumpTableInfo *MachineFunction::
129getOrCreateJumpTableInfo(unsigned EntryKind) {
130  if (JumpTableInfo) return JumpTableInfo;
131
132  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
133    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
134  return JumpTableInfo;
135}
136
137/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
138/// recomputes them.  This guarantees that the MBB numbers are sequential,
139/// dense, and match the ordering of the blocks within the function.  If a
140/// specific MachineBasicBlock is specified, only that block and those after
141/// it are renumbered.
142void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
143  if (empty()) { MBBNumbering.clear(); return; }
144  MachineFunction::iterator MBBI, E = end();
145  if (MBB == 0)
146    MBBI = begin();
147  else
148    MBBI = MBB;
149
150  // Figure out the block number this should have.
151  unsigned BlockNo = 0;
152  if (MBBI != begin())
153    BlockNo = prior(MBBI)->getNumber()+1;
154
155  for (; MBBI != E; ++MBBI, ++BlockNo) {
156    if (MBBI->getNumber() != (int)BlockNo) {
157      // Remove use of the old number.
158      if (MBBI->getNumber() != -1) {
159        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
160               "MBB number mismatch!");
161        MBBNumbering[MBBI->getNumber()] = 0;
162      }
163
164      // If BlockNo is already taken, set that block's number to -1.
165      if (MBBNumbering[BlockNo])
166        MBBNumbering[BlockNo]->setNumber(-1);
167
168      MBBNumbering[BlockNo] = MBBI;
169      MBBI->setNumber(BlockNo);
170    }
171  }
172
173  // Okay, all the blocks are renumbered.  If we have compactified the block
174  // numbering, shrink MBBNumbering now.
175  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
176  MBBNumbering.resize(BlockNo);
177}
178
179/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
180/// of `new MachineInstr'.
181///
182MachineInstr *
183MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
184                                    DebugLoc DL, bool NoImp) {
185  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
186    MachineInstr(TID, DL, NoImp);
187}
188
189/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
190/// 'Orig' instruction, identical in all ways except the the instruction
191/// has no parent, prev, or next.
192///
193MachineInstr *
194MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
195  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
196             MachineInstr(*this, *Orig);
197}
198
199/// DeleteMachineInstr - Delete the given MachineInstr.
200///
201void
202MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
203  MI->~MachineInstr();
204  InstructionRecycler.Deallocate(Allocator, MI);
205}
206
207/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
208/// instead of `new MachineBasicBlock'.
209///
210MachineBasicBlock *
211MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
212  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
213             MachineBasicBlock(*this, bb);
214}
215
216/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
217///
218void
219MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
220  assert(MBB->getParent() == this && "MBB parent mismatch!");
221  MBB->~MachineBasicBlock();
222  BasicBlockRecycler.Deallocate(Allocator, MBB);
223}
224
225MachineMemOperand *
226MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
227                                      int64_t o, uint64_t s,
228                                      unsigned base_alignment) {
229  return new (Allocator.Allocate<MachineMemOperand>())
230             MachineMemOperand(v, f, o, s, base_alignment);
231}
232
233MachineMemOperand *
234MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
235                                      int64_t Offset, uint64_t Size) {
236  return new (Allocator.Allocate<MachineMemOperand>())
237             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
238                               int64_t(uint64_t(MMO->getOffset()) +
239                                       uint64_t(Offset)),
240                               Size, MMO->getBaseAlignment());
241}
242
243MachineInstr::mmo_iterator
244MachineFunction::allocateMemRefsArray(unsigned long Num) {
245  return Allocator.Allocate<MachineMemOperand *>(Num);
246}
247
248std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
249MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
250                                    MachineInstr::mmo_iterator End) {
251  // Count the number of load mem refs.
252  unsigned Num = 0;
253  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
254    if ((*I)->isLoad())
255      ++Num;
256
257  // Allocate a new array and populate it with the load information.
258  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
259  unsigned Index = 0;
260  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
261    if ((*I)->isLoad()) {
262      if (!(*I)->isStore())
263        // Reuse the MMO.
264        Result[Index] = *I;
265      else {
266        // Clone the MMO and unset the store flag.
267        MachineMemOperand *JustLoad =
268          getMachineMemOperand((*I)->getValue(),
269                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
270                               (*I)->getOffset(), (*I)->getSize(),
271                               (*I)->getBaseAlignment());
272        Result[Index] = JustLoad;
273      }
274      ++Index;
275    }
276  }
277  return std::make_pair(Result, Result + Num);
278}
279
280std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
281MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
282                                     MachineInstr::mmo_iterator End) {
283  // Count the number of load mem refs.
284  unsigned Num = 0;
285  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
286    if ((*I)->isStore())
287      ++Num;
288
289  // Allocate a new array and populate it with the store information.
290  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
291  unsigned Index = 0;
292  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
293    if ((*I)->isStore()) {
294      if (!(*I)->isLoad())
295        // Reuse the MMO.
296        Result[Index] = *I;
297      else {
298        // Clone the MMO and unset the load flag.
299        MachineMemOperand *JustStore =
300          getMachineMemOperand((*I)->getValue(),
301                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
302                               (*I)->getOffset(), (*I)->getSize(),
303                               (*I)->getBaseAlignment());
304        Result[Index] = JustStore;
305      }
306      ++Index;
307    }
308  }
309  return std::make_pair(Result, Result + Num);
310}
311
312void MachineFunction::dump() const {
313  print(dbgs());
314}
315
316void MachineFunction::print(raw_ostream &OS) const {
317  OS << "# Machine code for function " << Fn->getName() << ":\n";
318
319  // Print Frame Information
320  FrameInfo->print(*this, OS);
321
322  // Print JumpTable Information
323  if (JumpTableInfo)
324    JumpTableInfo->print(OS);
325
326  // Print Constant Pool
327  ConstantPool->print(OS);
328
329  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
330
331  if (RegInfo && !RegInfo->livein_empty()) {
332    OS << "Function Live Ins: ";
333    for (MachineRegisterInfo::livein_iterator
334         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
335      if (TRI)
336        OS << "%" << TRI->getName(I->first);
337      else
338        OS << " %physreg" << I->first;
339
340      if (I->second)
341        OS << " in reg%" << I->second;
342
343      if (llvm::next(I) != E)
344        OS << ", ";
345    }
346    OS << '\n';
347  }
348  if (RegInfo && !RegInfo->liveout_empty()) {
349    OS << "Function Live Outs: ";
350    for (MachineRegisterInfo::liveout_iterator
351         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){
352      if (TRI)
353        OS << '%' << TRI->getName(*I);
354      else
355        OS << "%physreg" << *I;
356
357      if (llvm::next(I) != E)
358        OS << " ";
359    }
360    OS << '\n';
361  }
362
363  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
364    OS << '\n';
365    BB->print(OS);
366  }
367
368  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
369}
370
371namespace llvm {
372  template<>
373  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
374
375  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
376
377    static std::string getGraphName(const MachineFunction *F) {
378      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
379    }
380
381    std::string getNodeLabel(const MachineBasicBlock *Node,
382                             const MachineFunction *Graph) {
383      if (isSimple () && Node->getBasicBlock() &&
384          !Node->getBasicBlock()->getName().empty())
385        return Node->getBasicBlock()->getNameStr() + ":";
386
387      std::string OutStr;
388      {
389        raw_string_ostream OSS(OutStr);
390
391        if (isSimple())
392          OSS << Node->getNumber() << ':';
393        else
394          Node->print(OSS);
395      }
396
397      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
398
399      // Process string output to make it nicer...
400      for (unsigned i = 0; i != OutStr.length(); ++i)
401        if (OutStr[i] == '\n') {                            // Left justify
402          OutStr[i] = '\\';
403          OutStr.insert(OutStr.begin()+i+1, 'l');
404        }
405      return OutStr;
406    }
407  };
408}
409
410void MachineFunction::viewCFG() const
411{
412#ifndef NDEBUG
413  ViewGraph(this, "mf" + getFunction()->getNameStr());
414#else
415  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
416         << "systems with Graphviz or gv!\n";
417#endif // NDEBUG
418}
419
420void MachineFunction::viewCFGOnly() const
421{
422#ifndef NDEBUG
423  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
424#else
425  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
426         << "systems with Graphviz or gv!\n";
427#endif // NDEBUG
428}
429
430/// addLiveIn - Add the specified physical register as a live-in value and
431/// create a corresponding virtual register for it.
432unsigned MachineFunction::addLiveIn(unsigned PReg,
433                                    const TargetRegisterClass *RC) {
434  assert(RC->contains(PReg) && "Not the correct regclass!");
435  unsigned VReg = getRegInfo().createVirtualRegister(RC);
436  getRegInfo().addLiveIn(PReg, VReg);
437  return VReg;
438}
439
440/// getDILocation - Get the DILocation for a given DebugLoc object.
441DILocation MachineFunction::getDILocation(DebugLoc DL) const {
442  unsigned Idx = DL.getIndex();
443  assert(Idx < DebugLocInfo.DebugLocations.size() &&
444         "Invalid index into debug locations!");
445  return DILocation(DebugLocInfo.DebugLocations[Idx]);
446}
447
448
449/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
450/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
451/// normal 'L' label is returned.
452MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
453                                        bool isLinkerPrivate) const {
454  assert(JumpTableInfo && "No jump tables");
455
456  const std::vector<MachineJumpTableEntry> &JTs =JumpTableInfo->getJumpTables();
457  assert(JTI < JTs.size() && "Invalid JTI!");
458  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
459
460  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
461                                         MAI.getPrivateGlobalPrefix();
462  SmallString<60> Name;
463  raw_svector_ostream(Name)
464    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
465  return Ctx.GetOrCreateSymbol(Name.str());
466}
467
468
469//===----------------------------------------------------------------------===//
470//  MachineFrameInfo implementation
471//===----------------------------------------------------------------------===//
472
473/// CreateFixedObject - Create a new object at a fixed location on the stack.
474/// All fixed objects should be created before other objects are created for
475/// efficiency. By default, fixed objects are immutable. This returns an
476/// index with a negative value.
477///
478int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
479                                        bool Immutable, bool isSS) {
480  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
481  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable,
482                                              isSS));
483  return -++NumFixedObjects;
484}
485
486
487BitVector
488MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
489  assert(MBB && "MBB must be valid");
490  const MachineFunction *MF = MBB->getParent();
491  assert(MF && "MBB must be part of a MachineFunction");
492  const TargetMachine &TM = MF->getTarget();
493  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
494  BitVector BV(TRI->getNumRegs());
495
496  // Before CSI is calculated, no registers are considered pristine. They can be
497  // freely used and PEI will make sure they are saved.
498  if (!isCalleeSavedInfoValid())
499    return BV;
500
501  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
502    BV.set(*CSR);
503
504  // The entry MBB always has all CSRs pristine.
505  if (MBB == &MF->front())
506    return BV;
507
508  // On other MBBs the saved CSRs are not pristine.
509  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
510  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
511         E = CSI.end(); I != E; ++I)
512    BV.reset(I->getReg());
513
514  return BV;
515}
516
517
518void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
519  if (Objects.empty()) return;
520
521  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
522  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
523
524  OS << "Frame Objects:\n";
525
526  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
527    const StackObject &SO = Objects[i];
528    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
529    if (SO.Size == ~0ULL) {
530      OS << "dead\n";
531      continue;
532    }
533    if (SO.Size == 0)
534      OS << "variable sized";
535    else
536      OS << "size=" << SO.Size;
537    OS << ", align=" << SO.Alignment;
538
539    if (i < NumFixedObjects)
540      OS << ", fixed";
541    if (i < NumFixedObjects || SO.SPOffset != -1) {
542      int64_t Off = SO.SPOffset - ValOffset;
543      OS << ", at location [SP";
544      if (Off > 0)
545        OS << "+" << Off;
546      else if (Off < 0)
547        OS << Off;
548      OS << "]";
549    }
550    OS << "\n";
551  }
552}
553
554void MachineFrameInfo::dump(const MachineFunction &MF) const {
555  print(MF, dbgs());
556}
557
558//===----------------------------------------------------------------------===//
559//  MachineJumpTableInfo implementation
560//===----------------------------------------------------------------------===//
561
562/// getEntrySize - Return the size of each entry in the jump table.
563unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
564  // The size of a jump table entry is 4 bytes unless the entry is just the
565  // address of a block, in which case it is the pointer size.
566  switch (getEntryKind()) {
567  case MachineJumpTableInfo::EK_BlockAddress:
568    return TD.getPointerSize();
569  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
570  case MachineJumpTableInfo::EK_LabelDifference32:
571  case MachineJumpTableInfo::EK_Custom32:
572    return 4;
573  }
574  assert(0 && "Unknown jump table encoding!");
575  return ~0;
576}
577
578/// getEntryAlignment - Return the alignment of each entry in the jump table.
579unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
580  // The alignment of a jump table entry is the alignment of int32 unless the
581  // entry is just the address of a block, in which case it is the pointer
582  // alignment.
583  switch (getEntryKind()) {
584  case MachineJumpTableInfo::EK_BlockAddress:
585    return TD.getPointerABIAlignment();
586  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
587  case MachineJumpTableInfo::EK_LabelDifference32:
588  case MachineJumpTableInfo::EK_Custom32:
589    return TD.getABIIntegerTypeAlignment(32);
590  }
591  assert(0 && "Unknown jump table encoding!");
592  return ~0;
593}
594
595/// getJumpTableIndex - Create a new jump table entry in the jump table info
596/// or return an existing one.
597///
598unsigned MachineJumpTableInfo::getJumpTableIndex(
599                               const std::vector<MachineBasicBlock*> &DestBBs) {
600  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
601  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
602  return JumpTables.size()-1;
603}
604
605
606/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
607/// the jump tables to branch to New instead.
608bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
609                                                  MachineBasicBlock *New) {
610  assert(Old != New && "Not making a change?");
611  bool MadeChange = false;
612  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
613    ReplaceMBBInJumpTable(i, Old, New);
614  return MadeChange;
615}
616
617/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
618/// the jump table to branch to New instead.
619bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
620                                                 MachineBasicBlock *Old,
621                                                 MachineBasicBlock *New) {
622  assert(Old != New && "Not making a change?");
623  bool MadeChange = false;
624  MachineJumpTableEntry &JTE = JumpTables[Idx];
625  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
626    if (JTE.MBBs[j] == Old) {
627      JTE.MBBs[j] = New;
628      MadeChange = true;
629    }
630  return MadeChange;
631}
632
633void MachineJumpTableInfo::print(raw_ostream &OS) const {
634  if (JumpTables.empty()) return;
635
636  OS << "Jump Tables:\n";
637
638  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
639    OS << "  jt#" << i << ": ";
640    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
641      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
642  }
643
644  OS << '\n';
645}
646
647void MachineJumpTableInfo::dump() const { print(dbgs()); }
648
649
650//===----------------------------------------------------------------------===//
651//  MachineConstantPool implementation
652//===----------------------------------------------------------------------===//
653
654const Type *MachineConstantPoolEntry::getType() const {
655  if (isMachineConstantPoolEntry())
656    return Val.MachineCPVal->getType();
657  return Val.ConstVal->getType();
658}
659
660
661unsigned MachineConstantPoolEntry::getRelocationInfo() const {
662  if (isMachineConstantPoolEntry())
663    return Val.MachineCPVal->getRelocationInfo();
664  return Val.ConstVal->getRelocationInfo();
665}
666
667MachineConstantPool::~MachineConstantPool() {
668  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
669    if (Constants[i].isMachineConstantPoolEntry())
670      delete Constants[i].Val.MachineCPVal;
671}
672
673/// CanShareConstantPoolEntry - Test whether the given two constants
674/// can be allocated the same constant pool entry.
675static bool CanShareConstantPoolEntry(Constant *A, Constant *B,
676                                      const TargetData *TD) {
677  // Handle the trivial case quickly.
678  if (A == B) return true;
679
680  // If they have the same type but weren't the same constant, quickly
681  // reject them.
682  if (A->getType() == B->getType()) return false;
683
684  // For now, only support constants with the same size.
685  if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
686    return false;
687
688  // If a floating-point value and an integer value have the same encoding,
689  // they can share a constant-pool entry.
690  if (ConstantFP *AFP = dyn_cast<ConstantFP>(A))
691    if (ConstantInt *BI = dyn_cast<ConstantInt>(B))
692      return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
693  if (ConstantFP *BFP = dyn_cast<ConstantFP>(B))
694    if (ConstantInt *AI = dyn_cast<ConstantInt>(A))
695      return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
696
697  // Two vectors can share an entry if each pair of corresponding
698  // elements could.
699  if (ConstantVector *AV = dyn_cast<ConstantVector>(A))
700    if (ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
701      if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
702        return false;
703      for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
704        if (!CanShareConstantPoolEntry(AV->getOperand(i),
705                                       BV->getOperand(i), TD))
706          return false;
707      return true;
708    }
709
710  // TODO: Handle other cases.
711
712  return false;
713}
714
715/// getConstantPoolIndex - Create a new entry in the constant pool or return
716/// an existing one.  User must specify the log2 of the minimum required
717/// alignment for the object.
718///
719unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
720                                                   unsigned Alignment) {
721  assert(Alignment && "Alignment must be specified!");
722  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
723
724  // Check to see if we already have this constant.
725  //
726  // FIXME, this could be made much more efficient for large constant pools.
727  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
728    if (!Constants[i].isMachineConstantPoolEntry() &&
729        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
730      if ((unsigned)Constants[i].getAlignment() < Alignment)
731        Constants[i].Alignment = Alignment;
732      return i;
733    }
734
735  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
736  return Constants.size()-1;
737}
738
739unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
740                                                   unsigned Alignment) {
741  assert(Alignment && "Alignment must be specified!");
742  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
743
744  // Check to see if we already have this constant.
745  //
746  // FIXME, this could be made much more efficient for large constant pools.
747  int Idx = V->getExistingMachineCPValue(this, Alignment);
748  if (Idx != -1)
749    return (unsigned)Idx;
750
751  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
752  return Constants.size()-1;
753}
754
755void MachineConstantPool::print(raw_ostream &OS) const {
756  if (Constants.empty()) return;
757
758  OS << "Constant Pool:\n";
759  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
760    OS << "  cp#" << i << ": ";
761    if (Constants[i].isMachineConstantPoolEntry())
762      Constants[i].Val.MachineCPVal->print(OS);
763    else
764      OS << *(Value*)Constants[i].Val.ConstVal;
765    OS << ", align=" << Constants[i].getAlignment();
766    OS << "\n";
767  }
768}
769
770void MachineConstantPool::dump() const { print(dbgs()); }
771