MachineFunction.cpp revision 5567869637383969dced0b84dbd19da12682df6b 
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()->getFunctionAlignment(F);
69  FunctionNumber = FunctionNum;
70  JumpTableInfo = 0;
71}
72
73MachineFunction::~MachineFunction() {
74  BasicBlocks.clear();
75  InstructionRecycler.clear(Allocator);
76  BasicBlockRecycler.clear(Allocator);
77  if (RegInfo) {
78    RegInfo->~MachineRegisterInfo();
79    Allocator.Deallocate(RegInfo);
80  }
81  if (MFInfo) {
82    MFInfo->~MachineFunctionInfo();
83    Allocator.Deallocate(MFInfo);
84  }
85  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
86  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
87
88  if (JumpTableInfo) {
89    JumpTableInfo->~MachineJumpTableInfo();
90    Allocator.Deallocate(JumpTableInfo);
91  }
92}
93
94/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
95/// does already exist, allocate one.
96MachineJumpTableInfo *MachineFunction::
97getOrCreateJumpTableInfo(unsigned EntryKind) {
98  if (JumpTableInfo) return JumpTableInfo;
99
100  JumpTableInfo = new (Allocator)
101    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
102  return JumpTableInfo;
103}
104
105/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
106/// recomputes them.  This guarantees that the MBB numbers are sequential,
107/// dense, and match the ordering of the blocks within the function.  If a
108/// specific MachineBasicBlock is specified, only that block and those after
109/// it are renumbered.
110void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
111  if (empty()) { MBBNumbering.clear(); return; }
112  MachineFunction::iterator MBBI, E = end();
113  if (MBB == 0)
114    MBBI = begin();
115  else
116    MBBI = MBB;
117
118  // Figure out the block number this should have.
119  unsigned BlockNo = 0;
120  if (MBBI != begin())
121    BlockNo = prior(MBBI)->getNumber()+1;
122
123  for (; MBBI != E; ++MBBI, ++BlockNo) {
124    if (MBBI->getNumber() != (int)BlockNo) {
125      // Remove use of the old number.
126      if (MBBI->getNumber() != -1) {
127        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
128               "MBB number mismatch!");
129        MBBNumbering[MBBI->getNumber()] = 0;
130      }
131
132      // If BlockNo is already taken, set that block's number to -1.
133      if (MBBNumbering[BlockNo])
134        MBBNumbering[BlockNo]->setNumber(-1);
135
136      MBBNumbering[BlockNo] = MBBI;
137      MBBI->setNumber(BlockNo);
138    }
139  }
140
141  // Okay, all the blocks are renumbered.  If we have compactified the block
142  // numbering, shrink MBBNumbering now.
143  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
144  MBBNumbering.resize(BlockNo);
145}
146
147/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
148/// of `new MachineInstr'.
149///
150MachineInstr *
151MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
152                                    DebugLoc DL, bool NoImp) {
153  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
154    MachineInstr(TID, DL, NoImp);
155}
156
157/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
158/// 'Orig' instruction, identical in all ways except the instruction
159/// has no parent, prev, or next.
160///
161MachineInstr *
162MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
163  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
164             MachineInstr(*this, *Orig);
165}
166
167/// DeleteMachineInstr - Delete the given MachineInstr.
168///
169void
170MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
171  MI->~MachineInstr();
172  InstructionRecycler.Deallocate(Allocator, MI);
173}
174
175/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
176/// instead of `new MachineBasicBlock'.
177///
178MachineBasicBlock *
179MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
180  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
181             MachineBasicBlock(*this, bb);
182}
183
184/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
185///
186void
187MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
188  assert(MBB->getParent() == this && "MBB parent mismatch!");
189  MBB->~MachineBasicBlock();
190  BasicBlockRecycler.Deallocate(Allocator, MBB);
191}
192
193MachineMemOperand *
194MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
195                                      uint64_t s, unsigned base_alignment,
196                                      const MDNode *TBAAInfo) {
197  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
198                                           TBAAInfo);
199}
200
201MachineMemOperand *
202MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
203                                      int64_t Offset, uint64_t Size) {
204  return new (Allocator)
205             MachineMemOperand(MachinePointerInfo(MMO->getValue(),
206                                                  MMO->getOffset()+Offset),
207                               MMO->getFlags(), Size,
208                               MMO->getBaseAlignment(), 0);
209}
210
211MachineInstr::mmo_iterator
212MachineFunction::allocateMemRefsArray(unsigned long Num) {
213  return Allocator.Allocate<MachineMemOperand *>(Num);
214}
215
216std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
217MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
218                                    MachineInstr::mmo_iterator End) {
219  // Count the number of load mem refs.
220  unsigned Num = 0;
221  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
222    if ((*I)->isLoad())
223      ++Num;
224
225  // Allocate a new array and populate it with the load information.
226  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
227  unsigned Index = 0;
228  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
229    if ((*I)->isLoad()) {
230      if (!(*I)->isStore())
231        // Reuse the MMO.
232        Result[Index] = *I;
233      else {
234        // Clone the MMO and unset the store flag.
235        MachineMemOperand *JustLoad =
236          getMachineMemOperand((*I)->getPointerInfo(),
237                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
238                               (*I)->getSize(), (*I)->getBaseAlignment(),
239                               (*I)->getTBAAInfo());
240        Result[Index] = JustLoad;
241      }
242      ++Index;
243    }
244  }
245  return std::make_pair(Result, Result + Num);
246}
247
248std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
249MachineFunction::extractStoreMemRefs(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)->isStore())
255      ++Num;
256
257  // Allocate a new array and populate it with the store 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)->isStore()) {
262      if (!(*I)->isLoad())
263        // Reuse the MMO.
264        Result[Index] = *I;
265      else {
266        // Clone the MMO and unset the load flag.
267        MachineMemOperand *JustStore =
268          getMachineMemOperand((*I)->getPointerInfo(),
269                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
270                               (*I)->getSize(), (*I)->getBaseAlignment(),
271                               (*I)->getTBAAInfo());
272        Result[Index] = JustStore;
273      }
274      ++Index;
275    }
276  }
277  return std::make_pair(Result, Result + Num);
278}
279
280void MachineFunction::dump() const {
281  print(dbgs());
282}
283
284void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
285  OS << "# Machine code for function " << Fn->getName() << ":\n";
286
287  // Print Frame Information
288  FrameInfo->print(*this, OS);
289
290  // Print JumpTable Information
291  if (JumpTableInfo)
292    JumpTableInfo->print(OS);
293
294  // Print Constant Pool
295  ConstantPool->print(OS);
296
297  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
298
299  if (RegInfo && !RegInfo->livein_empty()) {
300    OS << "Function Live Ins: ";
301    for (MachineRegisterInfo::livein_iterator
302         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
303      if (TRI)
304        OS << "%" << TRI->getName(I->first);
305      else
306        OS << " %physreg" << I->first;
307
308      if (I->second)
309        OS << " in reg%" << I->second;
310
311      if (llvm::next(I) != E)
312        OS << ", ";
313    }
314    OS << '\n';
315  }
316  if (RegInfo && !RegInfo->liveout_empty()) {
317    OS << "Function Live Outs: ";
318    for (MachineRegisterInfo::liveout_iterator
319         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){
320      if (TRI)
321        OS << '%' << TRI->getName(*I);
322      else
323        OS << "%physreg" << *I;
324
325      if (llvm::next(I) != E)
326        OS << " ";
327    }
328    OS << '\n';
329  }
330
331  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
332    OS << '\n';
333    BB->print(OS, Indexes);
334  }
335
336  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
337}
338
339namespace llvm {
340  template<>
341  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
342
343  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
344
345    static std::string getGraphName(const MachineFunction *F) {
346      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
347    }
348
349    std::string getNodeLabel(const MachineBasicBlock *Node,
350                             const MachineFunction *Graph) {
351      std::string OutStr;
352      {
353        raw_string_ostream OSS(OutStr);
354
355        if (isSimple()) {
356          OSS << "BB#" << Node->getNumber();
357          if (const BasicBlock *BB = Node->getBasicBlock())
358            OSS << ": " << BB->getName();
359        } else
360          Node->print(OSS);
361      }
362
363      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
364
365      // Process string output to make it nicer...
366      for (unsigned i = 0; i != OutStr.length(); ++i)
367        if (OutStr[i] == '\n') {                            // Left justify
368          OutStr[i] = '\\';
369          OutStr.insert(OutStr.begin()+i+1, 'l');
370        }
371      return OutStr;
372    }
373  };
374}
375
376void MachineFunction::viewCFG() const
377{
378#ifndef NDEBUG
379  ViewGraph(this, "mf" + getFunction()->getNameStr());
380#else
381  errs() << "MachineFunction::viewCFG is only available in debug builds on "
382         << "systems with Graphviz or gv!\n";
383#endif // NDEBUG
384}
385
386void MachineFunction::viewCFGOnly() const
387{
388#ifndef NDEBUG
389  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
390#else
391  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
392         << "systems with Graphviz or gv!\n";
393#endif // NDEBUG
394}
395
396/// addLiveIn - Add the specified physical register as a live-in value and
397/// create a corresponding virtual register for it.
398unsigned MachineFunction::addLiveIn(unsigned PReg,
399                                    const TargetRegisterClass *RC) {
400  MachineRegisterInfo &MRI = getRegInfo();
401  unsigned VReg = MRI.getLiveInVirtReg(PReg);
402  if (VReg) {
403    assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
404    return VReg;
405  }
406  VReg = MRI.createVirtualRegister(RC);
407  MRI.addLiveIn(PReg, VReg);
408  return VReg;
409}
410
411/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
412/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
413/// normal 'L' label is returned.
414MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
415                                        bool isLinkerPrivate) const {
416  assert(JumpTableInfo && "No jump tables");
417
418  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
419  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
420
421  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
422                                         MAI.getPrivateGlobalPrefix();
423  SmallString<60> Name;
424  raw_svector_ostream(Name)
425    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
426  return Ctx.GetOrCreateSymbol(Name.str());
427}
428
429/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
430/// base.
431MCSymbol *MachineFunction::getPICBaseSymbol() const {
432  const MCAsmInfo &MAI = *Target.getMCAsmInfo();
433  return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
434                               Twine(getFunctionNumber())+"$pb");
435}
436
437//===----------------------------------------------------------------------===//
438//  MachineFrameInfo implementation
439//===----------------------------------------------------------------------===//
440
441/// CreateFixedObject - Create a new object at a fixed location on the stack.
442/// All fixed objects should be created before other objects are created for
443/// efficiency. By default, fixed objects are immutable. This returns an
444/// index with a negative value.
445///
446int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
447                                        bool Immutable) {
448  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
449  // The alignment of the frame index can be determined from its offset from
450  // the incoming frame position.  If the frame object is at offset 32 and
451  // the stack is guaranteed to be 16-byte aligned, then we know that the
452  // object is 16-byte aligned.
453  unsigned StackAlign = TFI.getStackAlignment();
454  unsigned Align = MinAlign(SPOffset, StackAlign);
455  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
456                                              /*isSS*/false, false));
457  return -++NumFixedObjects;
458}
459
460
461BitVector
462MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
463  assert(MBB && "MBB must be valid");
464  const MachineFunction *MF = MBB->getParent();
465  assert(MF && "MBB must be part of a MachineFunction");
466  const TargetMachine &TM = MF->getTarget();
467  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
468  BitVector BV(TRI->getNumRegs());
469
470  // Before CSI is calculated, no registers are considered pristine. They can be
471  // freely used and PEI will make sure they are saved.
472  if (!isCalleeSavedInfoValid())
473    return BV;
474
475  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
476    BV.set(*CSR);
477
478  // The entry MBB always has all CSRs pristine.
479  if (MBB == &MF->front())
480    return BV;
481
482  // On other MBBs the saved CSRs are not pristine.
483  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
484  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
485         E = CSI.end(); I != E; ++I)
486    BV.reset(I->getReg());
487
488  return BV;
489}
490
491
492void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
493  if (Objects.empty()) return;
494
495  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
496  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
497
498  OS << "Frame Objects:\n";
499
500  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
501    const StackObject &SO = Objects[i];
502    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
503    if (SO.Size == ~0ULL) {
504      OS << "dead\n";
505      continue;
506    }
507    if (SO.Size == 0)
508      OS << "variable sized";
509    else
510      OS << "size=" << SO.Size;
511    OS << ", align=" << SO.Alignment;
512
513    if (i < NumFixedObjects)
514      OS << ", fixed";
515    if (i < NumFixedObjects || SO.SPOffset != -1) {
516      int64_t Off = SO.SPOffset - ValOffset;
517      OS << ", at location [SP";
518      if (Off > 0)
519        OS << "+" << Off;
520      else if (Off < 0)
521        OS << Off;
522      OS << "]";
523    }
524    OS << "\n";
525  }
526}
527
528void MachineFrameInfo::dump(const MachineFunction &MF) const {
529  print(MF, dbgs());
530}
531
532//===----------------------------------------------------------------------===//
533//  MachineJumpTableInfo implementation
534//===----------------------------------------------------------------------===//
535
536/// getEntrySize - Return the size of each entry in the jump table.
537unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
538  // The size of a jump table entry is 4 bytes unless the entry is just the
539  // address of a block, in which case it is the pointer size.
540  switch (getEntryKind()) {
541  case MachineJumpTableInfo::EK_BlockAddress:
542    return TD.getPointerSize();
543  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
544  case MachineJumpTableInfo::EK_LabelDifference32:
545  case MachineJumpTableInfo::EK_Custom32:
546    return 4;
547  case MachineJumpTableInfo::EK_Inline:
548    return 0;
549  }
550  assert(0 && "Unknown jump table encoding!");
551  return ~0;
552}
553
554/// getEntryAlignment - Return the alignment of each entry in the jump table.
555unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
556  // The alignment of a jump table entry is the alignment of int32 unless the
557  // entry is just the address of a block, in which case it is the pointer
558  // alignment.
559  switch (getEntryKind()) {
560  case MachineJumpTableInfo::EK_BlockAddress:
561    return TD.getPointerABIAlignment();
562  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
563  case MachineJumpTableInfo::EK_LabelDifference32:
564  case MachineJumpTableInfo::EK_Custom32:
565    return TD.getABIIntegerTypeAlignment(32);
566  case MachineJumpTableInfo::EK_Inline:
567    return 1;
568  }
569  assert(0 && "Unknown jump table encoding!");
570  return ~0;
571}
572
573/// createJumpTableIndex - Create a new jump table entry in the jump table info.
574///
575unsigned MachineJumpTableInfo::createJumpTableIndex(
576                               const std::vector<MachineBasicBlock*> &DestBBs) {
577  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
578  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
579  return JumpTables.size()-1;
580}
581
582/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
583/// the jump tables to branch to New instead.
584bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
585                                                  MachineBasicBlock *New) {
586  assert(Old != New && "Not making a change?");
587  bool MadeChange = false;
588  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
589    ReplaceMBBInJumpTable(i, Old, New);
590  return MadeChange;
591}
592
593/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
594/// the jump table to branch to New instead.
595bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
596                                                 MachineBasicBlock *Old,
597                                                 MachineBasicBlock *New) {
598  assert(Old != New && "Not making a change?");
599  bool MadeChange = false;
600  MachineJumpTableEntry &JTE = JumpTables[Idx];
601  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
602    if (JTE.MBBs[j] == Old) {
603      JTE.MBBs[j] = New;
604      MadeChange = true;
605    }
606  return MadeChange;
607}
608
609void MachineJumpTableInfo::print(raw_ostream &OS) const {
610  if (JumpTables.empty()) return;
611
612  OS << "Jump Tables:\n";
613
614  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
615    OS << "  jt#" << i << ": ";
616    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
617      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
618  }
619
620  OS << '\n';
621}
622
623void MachineJumpTableInfo::dump() const { print(dbgs()); }
624
625
626//===----------------------------------------------------------------------===//
627//  MachineConstantPool implementation
628//===----------------------------------------------------------------------===//
629
630const Type *MachineConstantPoolEntry::getType() const {
631  if (isMachineConstantPoolEntry())
632    return Val.MachineCPVal->getType();
633  return Val.ConstVal->getType();
634}
635
636
637unsigned MachineConstantPoolEntry::getRelocationInfo() const {
638  if (isMachineConstantPoolEntry())
639    return Val.MachineCPVal->getRelocationInfo();
640  return Val.ConstVal->getRelocationInfo();
641}
642
643MachineConstantPool::~MachineConstantPool() {
644  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
645    if (Constants[i].isMachineConstantPoolEntry())
646      delete Constants[i].Val.MachineCPVal;
647  for (DenseSet<MachineConstantPoolValue*>::iterator I =
648       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
649       I != E; ++I)
650    delete *I;
651}
652
653/// CanShareConstantPoolEntry - Test whether the given two constants
654/// can be allocated the same constant pool entry.
655static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
656                                      const TargetData *TD) {
657  // Handle the trivial case quickly.
658  if (A == B) return true;
659
660  // If they have the same type but weren't the same constant, quickly
661  // reject them.
662  if (A->getType() == B->getType()) return false;
663
664  // For now, only support constants with the same size.
665  if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
666    return false;
667
668  // If a floating-point value and an integer value have the same encoding,
669  // they can share a constant-pool entry.
670  if (const ConstantFP *AFP = dyn_cast<ConstantFP>(A))
671    if (const ConstantInt *BI = dyn_cast<ConstantInt>(B))
672      return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
673  if (const ConstantFP *BFP = dyn_cast<ConstantFP>(B))
674    if (const ConstantInt *AI = dyn_cast<ConstantInt>(A))
675      return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
676
677  // Two vectors can share an entry if each pair of corresponding
678  // elements could.
679  if (const ConstantVector *AV = dyn_cast<ConstantVector>(A))
680    if (const ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
681      if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
682        return false;
683      for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
684        if (!CanShareConstantPoolEntry(AV->getOperand(i),
685                                       BV->getOperand(i), TD))
686          return false;
687      return true;
688    }
689
690  // TODO: Handle other cases.
691
692  return false;
693}
694
695/// getConstantPoolIndex - Create a new entry in the constant pool or return
696/// an existing one.  User must specify the log2 of the minimum required
697/// alignment for the object.
698///
699unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
700                                                   unsigned Alignment) {
701  assert(Alignment && "Alignment must be specified!");
702  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
703
704  // Check to see if we already have this constant.
705  //
706  // FIXME, this could be made much more efficient for large constant pools.
707  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
708    if (!Constants[i].isMachineConstantPoolEntry() &&
709        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
710      if ((unsigned)Constants[i].getAlignment() < Alignment)
711        Constants[i].Alignment = Alignment;
712      return i;
713    }
714
715  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
716  return Constants.size()-1;
717}
718
719unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
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  int Idx = V->getExistingMachineCPValue(this, Alignment);
728  if (Idx != -1) {
729    MachineCPVsSharingEntries.insert(V);
730    return (unsigned)Idx;
731  }
732
733  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
734  return Constants.size()-1;
735}
736
737void MachineConstantPool::print(raw_ostream &OS) const {
738  if (Constants.empty()) return;
739
740  OS << "Constant Pool:\n";
741  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
742    OS << "  cp#" << i << ": ";
743    if (Constants[i].isMachineConstantPoolEntry())
744      Constants[i].Val.MachineCPVal->print(OS);
745    else
746      OS << *(Value*)Constants[i].Val.ConstVal;
747    OS << ", align=" << Constants[i].getAlignment();
748    OS << "\n";
749  }
750}
751
752void MachineConstantPool::dump() const { print(dbgs()); }
753