MachineFunction.cpp revision e837dead3c8dc3445ef6a0e2322179c57e264a13 
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/MachineModuleInfo.h"
27#include "llvm/CodeGen/MachineRegisterInfo.h"
28#include "llvm/CodeGen/Passes.h"
29#include "llvm/MC/MCAsmInfo.h"
30#include "llvm/MC/MCContext.h"
31#include "llvm/Analysis/DebugInfo.h"
32#include "llvm/Support/Debug.h"
33#include "llvm/Target/TargetData.h"
34#include "llvm/Target/TargetLowering.h"
35#include "llvm/Target/TargetMachine.h"
36#include "llvm/Target/TargetFrameLowering.h"
37#include "llvm/ADT/SmallString.h"
38#include "llvm/ADT/STLExtras.h"
39#include "llvm/Support/GraphWriter.h"
40#include "llvm/Support/raw_ostream.h"
41using namespace llvm;
42
43//===----------------------------------------------------------------------===//
44// MachineFunction implementation
45//===----------------------------------------------------------------------===//
46
47// Out of line virtual method.
48MachineFunctionInfo::~MachineFunctionInfo() {}
49
50void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
51  MBB->getParent()->DeleteMachineBasicBlock(MBB);
52}
53
54MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
55                                 unsigned FunctionNum, MachineModuleInfo &mmi,
56                                 GCModuleInfo* gmi)
57  : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
58  if (TM.getRegisterInfo())
59    RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
60  else
61    RegInfo = 0;
62  MFInfo = 0;
63  FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering());
64  if (Fn->hasFnAttr(Attribute::StackAlignment))
65    FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
66        Fn->getAttributes().getFnAttributes()));
67  ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
68  Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
69  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
70  if (!Fn->hasFnAttr(Attribute::OptimizeForSize))
71    Alignment = std::max(Alignment,
72                         TM.getTargetLowering()->getPrefFunctionAlignment());
73  FunctionNumber = FunctionNum;
74  JumpTableInfo = 0;
75}
76
77MachineFunction::~MachineFunction() {
78  BasicBlocks.clear();
79  InstructionRecycler.clear(Allocator);
80  BasicBlockRecycler.clear(Allocator);
81  if (RegInfo) {
82    RegInfo->~MachineRegisterInfo();
83    Allocator.Deallocate(RegInfo);
84  }
85  if (MFInfo) {
86    MFInfo->~MachineFunctionInfo();
87    Allocator.Deallocate(MFInfo);
88  }
89  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
90  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
91
92  if (JumpTableInfo) {
93    JumpTableInfo->~MachineJumpTableInfo();
94    Allocator.Deallocate(JumpTableInfo);
95  }
96}
97
98/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
99/// does already exist, allocate one.
100MachineJumpTableInfo *MachineFunction::
101getOrCreateJumpTableInfo(unsigned EntryKind) {
102  if (JumpTableInfo) return JumpTableInfo;
103
104  JumpTableInfo = new (Allocator)
105    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
106  return JumpTableInfo;
107}
108
109/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
110/// recomputes them.  This guarantees that the MBB numbers are sequential,
111/// dense, and match the ordering of the blocks within the function.  If a
112/// specific MachineBasicBlock is specified, only that block and those after
113/// it are renumbered.
114void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
115  if (empty()) { MBBNumbering.clear(); return; }
116  MachineFunction::iterator MBBI, E = end();
117  if (MBB == 0)
118    MBBI = begin();
119  else
120    MBBI = MBB;
121
122  // Figure out the block number this should have.
123  unsigned BlockNo = 0;
124  if (MBBI != begin())
125    BlockNo = prior(MBBI)->getNumber()+1;
126
127  for (; MBBI != E; ++MBBI, ++BlockNo) {
128    if (MBBI->getNumber() != (int)BlockNo) {
129      // Remove use of the old number.
130      if (MBBI->getNumber() != -1) {
131        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
132               "MBB number mismatch!");
133        MBBNumbering[MBBI->getNumber()] = 0;
134      }
135
136      // If BlockNo is already taken, set that block's number to -1.
137      if (MBBNumbering[BlockNo])
138        MBBNumbering[BlockNo]->setNumber(-1);
139
140      MBBNumbering[BlockNo] = MBBI;
141      MBBI->setNumber(BlockNo);
142    }
143  }
144
145  // Okay, all the blocks are renumbered.  If we have compactified the block
146  // numbering, shrink MBBNumbering now.
147  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
148  MBBNumbering.resize(BlockNo);
149}
150
151/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
152/// of `new MachineInstr'.
153///
154MachineInstr *
155MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
156                                    DebugLoc DL, bool NoImp) {
157  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
158    MachineInstr(MCID, DL, NoImp);
159}
160
161/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
162/// 'Orig' instruction, identical in all ways except the instruction
163/// has no parent, prev, or next.
164///
165MachineInstr *
166MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
167  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
168             MachineInstr(*this, *Orig);
169}
170
171/// DeleteMachineInstr - Delete the given MachineInstr.
172///
173void
174MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
175  MI->~MachineInstr();
176  InstructionRecycler.Deallocate(Allocator, MI);
177}
178
179/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
180/// instead of `new MachineBasicBlock'.
181///
182MachineBasicBlock *
183MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
184  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
185             MachineBasicBlock(*this, bb);
186}
187
188/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
189///
190void
191MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
192  assert(MBB->getParent() == this && "MBB parent mismatch!");
193  MBB->~MachineBasicBlock();
194  BasicBlockRecycler.Deallocate(Allocator, MBB);
195}
196
197MachineMemOperand *
198MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
199                                      uint64_t s, unsigned base_alignment,
200                                      const MDNode *TBAAInfo) {
201  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
202                                           TBAAInfo);
203}
204
205MachineMemOperand *
206MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
207                                      int64_t Offset, uint64_t Size) {
208  return new (Allocator)
209             MachineMemOperand(MachinePointerInfo(MMO->getValue(),
210                                                  MMO->getOffset()+Offset),
211                               MMO->getFlags(), Size,
212                               MMO->getBaseAlignment(), 0);
213}
214
215MachineInstr::mmo_iterator
216MachineFunction::allocateMemRefsArray(unsigned long Num) {
217  return Allocator.Allocate<MachineMemOperand *>(Num);
218}
219
220std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
221MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
222                                    MachineInstr::mmo_iterator End) {
223  // Count the number of load mem refs.
224  unsigned Num = 0;
225  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
226    if ((*I)->isLoad())
227      ++Num;
228
229  // Allocate a new array and populate it with the load information.
230  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
231  unsigned Index = 0;
232  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
233    if ((*I)->isLoad()) {
234      if (!(*I)->isStore())
235        // Reuse the MMO.
236        Result[Index] = *I;
237      else {
238        // Clone the MMO and unset the store flag.
239        MachineMemOperand *JustLoad =
240          getMachineMemOperand((*I)->getPointerInfo(),
241                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
242                               (*I)->getSize(), (*I)->getBaseAlignment(),
243                               (*I)->getTBAAInfo());
244        Result[Index] = JustLoad;
245      }
246      ++Index;
247    }
248  }
249  return std::make_pair(Result, Result + Num);
250}
251
252std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
253MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
254                                     MachineInstr::mmo_iterator End) {
255  // Count the number of load mem refs.
256  unsigned Num = 0;
257  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
258    if ((*I)->isStore())
259      ++Num;
260
261  // Allocate a new array and populate it with the store information.
262  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
263  unsigned Index = 0;
264  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
265    if ((*I)->isStore()) {
266      if (!(*I)->isLoad())
267        // Reuse the MMO.
268        Result[Index] = *I;
269      else {
270        // Clone the MMO and unset the load flag.
271        MachineMemOperand *JustStore =
272          getMachineMemOperand((*I)->getPointerInfo(),
273                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
274                               (*I)->getSize(), (*I)->getBaseAlignment(),
275                               (*I)->getTBAAInfo());
276        Result[Index] = JustStore;
277      }
278      ++Index;
279    }
280  }
281  return std::make_pair(Result, Result + Num);
282}
283
284void MachineFunction::dump() const {
285  print(dbgs());
286}
287
288void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
289  OS << "# Machine code for function " << Fn->getName() << ":\n";
290
291  // Print Frame Information
292  FrameInfo->print(*this, OS);
293
294  // Print JumpTable Information
295  if (JumpTableInfo)
296    JumpTableInfo->print(OS);
297
298  // Print Constant Pool
299  ConstantPool->print(OS);
300
301  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
302
303  if (RegInfo && !RegInfo->livein_empty()) {
304    OS << "Function Live Ins: ";
305    for (MachineRegisterInfo::livein_iterator
306         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
307      OS << PrintReg(I->first, TRI);
308      if (I->second)
309        OS << " in " << PrintReg(I->second, TRI);
310      if (llvm::next(I) != E)
311        OS << ", ";
312    }
313    OS << '\n';
314  }
315  if (RegInfo && !RegInfo->liveout_empty()) {
316    OS << "Function Live Outs:";
317    for (MachineRegisterInfo::liveout_iterator
318         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
319      OS << ' ' << PrintReg(*I, TRI);
320    OS << '\n';
321  }
322
323  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
324    OS << '\n';
325    BB->print(OS, Indexes);
326  }
327
328  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
329}
330
331namespace llvm {
332  template<>
333  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
334
335  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
336
337    static std::string getGraphName(const MachineFunction *F) {
338      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
339    }
340
341    std::string getNodeLabel(const MachineBasicBlock *Node,
342                             const MachineFunction *Graph) {
343      std::string OutStr;
344      {
345        raw_string_ostream OSS(OutStr);
346
347        if (isSimple()) {
348          OSS << "BB#" << Node->getNumber();
349          if (const BasicBlock *BB = Node->getBasicBlock())
350            OSS << ": " << BB->getName();
351        } else
352          Node->print(OSS);
353      }
354
355      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
356
357      // Process string output to make it nicer...
358      for (unsigned i = 0; i != OutStr.length(); ++i)
359        if (OutStr[i] == '\n') {                            // Left justify
360          OutStr[i] = '\\';
361          OutStr.insert(OutStr.begin()+i+1, 'l');
362        }
363      return OutStr;
364    }
365  };
366}
367
368void MachineFunction::viewCFG() const
369{
370#ifndef NDEBUG
371  ViewGraph(this, "mf" + getFunction()->getNameStr());
372#else
373  errs() << "MachineFunction::viewCFG is only available in debug builds on "
374         << "systems with Graphviz or gv!\n";
375#endif // NDEBUG
376}
377
378void MachineFunction::viewCFGOnly() const
379{
380#ifndef NDEBUG
381  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
382#else
383  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
384         << "systems with Graphviz or gv!\n";
385#endif // NDEBUG
386}
387
388/// addLiveIn - Add the specified physical register as a live-in value and
389/// create a corresponding virtual register for it.
390unsigned MachineFunction::addLiveIn(unsigned PReg,
391                                    const TargetRegisterClass *RC) {
392  MachineRegisterInfo &MRI = getRegInfo();
393  unsigned VReg = MRI.getLiveInVirtReg(PReg);
394  if (VReg) {
395    assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
396    return VReg;
397  }
398  VReg = MRI.createVirtualRegister(RC);
399  MRI.addLiveIn(PReg, VReg);
400  return VReg;
401}
402
403/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
404/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
405/// normal 'L' label is returned.
406MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
407                                        bool isLinkerPrivate) const {
408  assert(JumpTableInfo && "No jump tables");
409
410  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
411  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
412
413  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
414                                         MAI.getPrivateGlobalPrefix();
415  SmallString<60> Name;
416  raw_svector_ostream(Name)
417    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
418  return Ctx.GetOrCreateSymbol(Name.str());
419}
420
421/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
422/// base.
423MCSymbol *MachineFunction::getPICBaseSymbol() const {
424  const MCAsmInfo &MAI = *Target.getMCAsmInfo();
425  return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
426                               Twine(getFunctionNumber())+"$pb");
427}
428
429//===----------------------------------------------------------------------===//
430//  MachineFrameInfo implementation
431//===----------------------------------------------------------------------===//
432
433/// CreateFixedObject - Create a new object at a fixed location on the stack.
434/// All fixed objects should be created before other objects are created for
435/// efficiency. By default, fixed objects are immutable. This returns an
436/// index with a negative value.
437///
438int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
439                                        bool Immutable) {
440  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
441  // The alignment of the frame index can be determined from its offset from
442  // the incoming frame position.  If the frame object is at offset 32 and
443  // the stack is guaranteed to be 16-byte aligned, then we know that the
444  // object is 16-byte aligned.
445  unsigned StackAlign = TFI.getStackAlignment();
446  unsigned Align = MinAlign(SPOffset, StackAlign);
447  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
448                                              /*isSS*/false, false));
449  return -++NumFixedObjects;
450}
451
452
453BitVector
454MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
455  assert(MBB && "MBB must be valid");
456  const MachineFunction *MF = MBB->getParent();
457  assert(MF && "MBB must be part of a MachineFunction");
458  const TargetMachine &TM = MF->getTarget();
459  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
460  BitVector BV(TRI->getNumRegs());
461
462  // Before CSI is calculated, no registers are considered pristine. They can be
463  // freely used and PEI will make sure they are saved.
464  if (!isCalleeSavedInfoValid())
465    return BV;
466
467  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
468    BV.set(*CSR);
469
470  // The entry MBB always has all CSRs pristine.
471  if (MBB == &MF->front())
472    return BV;
473
474  // On other MBBs the saved CSRs are not pristine.
475  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
476  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
477         E = CSI.end(); I != E; ++I)
478    BV.reset(I->getReg());
479
480  return BV;
481}
482
483
484void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
485  if (Objects.empty()) return;
486
487  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
488  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
489
490  OS << "Frame Objects:\n";
491
492  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
493    const StackObject &SO = Objects[i];
494    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
495    if (SO.Size == ~0ULL) {
496      OS << "dead\n";
497      continue;
498    }
499    if (SO.Size == 0)
500      OS << "variable sized";
501    else
502      OS << "size=" << SO.Size;
503    OS << ", align=" << SO.Alignment;
504
505    if (i < NumFixedObjects)
506      OS << ", fixed";
507    if (i < NumFixedObjects || SO.SPOffset != -1) {
508      int64_t Off = SO.SPOffset - ValOffset;
509      OS << ", at location [SP";
510      if (Off > 0)
511        OS << "+" << Off;
512      else if (Off < 0)
513        OS << Off;
514      OS << "]";
515    }
516    OS << "\n";
517  }
518}
519
520void MachineFrameInfo::dump(const MachineFunction &MF) const {
521  print(MF, dbgs());
522}
523
524//===----------------------------------------------------------------------===//
525//  MachineJumpTableInfo implementation
526//===----------------------------------------------------------------------===//
527
528/// getEntrySize - Return the size of each entry in the jump table.
529unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
530  // The size of a jump table entry is 4 bytes unless the entry is just the
531  // address of a block, in which case it is the pointer size.
532  switch (getEntryKind()) {
533  case MachineJumpTableInfo::EK_BlockAddress:
534    return TD.getPointerSize();
535  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
536  case MachineJumpTableInfo::EK_LabelDifference32:
537  case MachineJumpTableInfo::EK_Custom32:
538    return 4;
539  case MachineJumpTableInfo::EK_Inline:
540    return 0;
541  }
542  assert(0 && "Unknown jump table encoding!");
543  return ~0;
544}
545
546/// getEntryAlignment - Return the alignment of each entry in the jump table.
547unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
548  // The alignment of a jump table entry is the alignment of int32 unless the
549  // entry is just the address of a block, in which case it is the pointer
550  // alignment.
551  switch (getEntryKind()) {
552  case MachineJumpTableInfo::EK_BlockAddress:
553    return TD.getPointerABIAlignment();
554  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
555  case MachineJumpTableInfo::EK_LabelDifference32:
556  case MachineJumpTableInfo::EK_Custom32:
557    return TD.getABIIntegerTypeAlignment(32);
558  case MachineJumpTableInfo::EK_Inline:
559    return 1;
560  }
561  assert(0 && "Unknown jump table encoding!");
562  return ~0;
563}
564
565/// createJumpTableIndex - Create a new jump table entry in the jump table info.
566///
567unsigned MachineJumpTableInfo::createJumpTableIndex(
568                               const std::vector<MachineBasicBlock*> &DestBBs) {
569  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
570  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
571  return JumpTables.size()-1;
572}
573
574/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
575/// the jump tables to branch to New instead.
576bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
577                                                  MachineBasicBlock *New) {
578  assert(Old != New && "Not making a change?");
579  bool MadeChange = false;
580  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
581    ReplaceMBBInJumpTable(i, Old, New);
582  return MadeChange;
583}
584
585/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
586/// the jump table to branch to New instead.
587bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
588                                                 MachineBasicBlock *Old,
589                                                 MachineBasicBlock *New) {
590  assert(Old != New && "Not making a change?");
591  bool MadeChange = false;
592  MachineJumpTableEntry &JTE = JumpTables[Idx];
593  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
594    if (JTE.MBBs[j] == Old) {
595      JTE.MBBs[j] = New;
596      MadeChange = true;
597    }
598  return MadeChange;
599}
600
601void MachineJumpTableInfo::print(raw_ostream &OS) const {
602  if (JumpTables.empty()) return;
603
604  OS << "Jump Tables:\n";
605
606  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
607    OS << "  jt#" << i << ": ";
608    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
609      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
610  }
611
612  OS << '\n';
613}
614
615void MachineJumpTableInfo::dump() const { print(dbgs()); }
616
617
618//===----------------------------------------------------------------------===//
619//  MachineConstantPool implementation
620//===----------------------------------------------------------------------===//
621
622const Type *MachineConstantPoolEntry::getType() const {
623  if (isMachineConstantPoolEntry())
624    return Val.MachineCPVal->getType();
625  return Val.ConstVal->getType();
626}
627
628
629unsigned MachineConstantPoolEntry::getRelocationInfo() const {
630  if (isMachineConstantPoolEntry())
631    return Val.MachineCPVal->getRelocationInfo();
632  return Val.ConstVal->getRelocationInfo();
633}
634
635MachineConstantPool::~MachineConstantPool() {
636  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
637    if (Constants[i].isMachineConstantPoolEntry())
638      delete Constants[i].Val.MachineCPVal;
639  for (DenseSet<MachineConstantPoolValue*>::iterator I =
640       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
641       I != E; ++I)
642    delete *I;
643}
644
645/// CanShareConstantPoolEntry - Test whether the given two constants
646/// can be allocated the same constant pool entry.
647static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
648                                      const TargetData *TD) {
649  // Handle the trivial case quickly.
650  if (A == B) return true;
651
652  // If they have the same type but weren't the same constant, quickly
653  // reject them.
654  if (A->getType() == B->getType()) return false;
655
656  // For now, only support constants with the same size.
657  if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
658    return false;
659
660  // If a floating-point value and an integer value have the same encoding,
661  // they can share a constant-pool entry.
662  if (const ConstantFP *AFP = dyn_cast<ConstantFP>(A))
663    if (const ConstantInt *BI = dyn_cast<ConstantInt>(B))
664      return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
665  if (const ConstantFP *BFP = dyn_cast<ConstantFP>(B))
666    if (const ConstantInt *AI = dyn_cast<ConstantInt>(A))
667      return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
668
669  // Two vectors can share an entry if each pair of corresponding
670  // elements could.
671  if (const ConstantVector *AV = dyn_cast<ConstantVector>(A))
672    if (const ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
673      if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
674        return false;
675      for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
676        if (!CanShareConstantPoolEntry(AV->getOperand(i),
677                                       BV->getOperand(i), TD))
678          return false;
679      return true;
680    }
681
682  // TODO: Handle other cases.
683
684  return false;
685}
686
687/// getConstantPoolIndex - Create a new entry in the constant pool or return
688/// an existing one.  User must specify the log2 of the minimum required
689/// alignment for the object.
690///
691unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
692                                                   unsigned Alignment) {
693  assert(Alignment && "Alignment must be specified!");
694  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
695
696  // Check to see if we already have this constant.
697  //
698  // FIXME, this could be made much more efficient for large constant pools.
699  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
700    if (!Constants[i].isMachineConstantPoolEntry() &&
701        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
702      if ((unsigned)Constants[i].getAlignment() < Alignment)
703        Constants[i].Alignment = Alignment;
704      return i;
705    }
706
707  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
708  return Constants.size()-1;
709}
710
711unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
712                                                   unsigned Alignment) {
713  assert(Alignment && "Alignment must be specified!");
714  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
715
716  // Check to see if we already have this constant.
717  //
718  // FIXME, this could be made much more efficient for large constant pools.
719  int Idx = V->getExistingMachineCPValue(this, Alignment);
720  if (Idx != -1) {
721    MachineCPVsSharingEntries.insert(V);
722    return (unsigned)Idx;
723  }
724
725  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
726  return Constants.size()-1;
727}
728
729void MachineConstantPool::print(raw_ostream &OS) const {
730  if (Constants.empty()) return;
731
732  OS << "Constant Pool:\n";
733  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
734    OS << "  cp#" << i << ": ";
735    if (Constants[i].isMachineConstantPoolEntry())
736      Constants[i].Val.MachineCPVal->print(OS);
737    else
738      OS << *(Value*)Constants[i].Val.ConstVal;
739    OS << ", align=" << Constants[i].getAlignment();
740    OS << "\n";
741  }
742}
743
744void MachineConstantPool::dump() const { print(dbgs()); }
745