MachineFunction.cpp revision d1ec31dca534a8816d7f2fcbfdc7ed4476b471d3 
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, MCContext &ctx)
89  : Fn(F), Target(TM), Ctx(ctx) {
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  if (Fn->hasFnAttr(Attribute::StackAlignment))
99    FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
100        Fn->getAttributes().getFnAttributes()));
101  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
102                     MachineConstantPool(TM.getTargetData());
103  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
104  FunctionNumber = FunctionNum;
105  JumpTableInfo = 0;
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
123  if (JumpTableInfo) {
124    JumpTableInfo->~MachineJumpTableInfo();
125    Allocator.Deallocate(JumpTableInfo);
126  }
127}
128
129/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
130/// does already exist, allocate one.
131MachineJumpTableInfo *MachineFunction::
132getOrCreateJumpTableInfo(unsigned EntryKind) {
133  if (JumpTableInfo) return JumpTableInfo;
134
135  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
136    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
137  return JumpTableInfo;
138}
139
140/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
141/// recomputes them.  This guarantees that the MBB numbers are sequential,
142/// dense, and match the ordering of the blocks within the function.  If a
143/// specific MachineBasicBlock is specified, only that block and those after
144/// it are renumbered.
145void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
146  if (empty()) { MBBNumbering.clear(); return; }
147  MachineFunction::iterator MBBI, E = end();
148  if (MBB == 0)
149    MBBI = begin();
150  else
151    MBBI = MBB;
152
153  // Figure out the block number this should have.
154  unsigned BlockNo = 0;
155  if (MBBI != begin())
156    BlockNo = prior(MBBI)->getNumber()+1;
157
158  for (; MBBI != E; ++MBBI, ++BlockNo) {
159    if (MBBI->getNumber() != (int)BlockNo) {
160      // Remove use of the old number.
161      if (MBBI->getNumber() != -1) {
162        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
163               "MBB number mismatch!");
164        MBBNumbering[MBBI->getNumber()] = 0;
165      }
166
167      // If BlockNo is already taken, set that block's number to -1.
168      if (MBBNumbering[BlockNo])
169        MBBNumbering[BlockNo]->setNumber(-1);
170
171      MBBNumbering[BlockNo] = MBBI;
172      MBBI->setNumber(BlockNo);
173    }
174  }
175
176  // Okay, all the blocks are renumbered.  If we have compactified the block
177  // numbering, shrink MBBNumbering now.
178  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
179  MBBNumbering.resize(BlockNo);
180}
181
182/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
183/// of `new MachineInstr'.
184///
185MachineInstr *
186MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
187                                    DebugLoc DL, bool NoImp) {
188  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
189    MachineInstr(TID, DL, NoImp);
190}
191
192/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
193/// 'Orig' instruction, identical in all ways except the instruction
194/// has no parent, prev, or next.
195///
196MachineInstr *
197MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
198  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
199             MachineInstr(*this, *Orig);
200}
201
202/// DeleteMachineInstr - Delete the given MachineInstr.
203///
204void
205MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
206  MI->~MachineInstr();
207  InstructionRecycler.Deallocate(Allocator, MI);
208}
209
210/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
211/// instead of `new MachineBasicBlock'.
212///
213MachineBasicBlock *
214MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
215  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
216             MachineBasicBlock(*this, bb);
217}
218
219/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
220///
221void
222MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
223  assert(MBB->getParent() == this && "MBB parent mismatch!");
224  MBB->~MachineBasicBlock();
225  BasicBlockRecycler.Deallocate(Allocator, MBB);
226}
227
228MachineMemOperand *
229MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
230                                      int64_t o, uint64_t s,
231                                      unsigned base_alignment) {
232  return new (Allocator.Allocate<MachineMemOperand>())
233             MachineMemOperand(v, f, o, s, base_alignment);
234}
235
236MachineMemOperand *
237MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
238                                      int64_t Offset, uint64_t Size) {
239  return new (Allocator.Allocate<MachineMemOperand>())
240             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
241                               int64_t(uint64_t(MMO->getOffset()) +
242                                       uint64_t(Offset)),
243                               Size, MMO->getBaseAlignment());
244}
245
246MachineInstr::mmo_iterator
247MachineFunction::allocateMemRefsArray(unsigned long Num) {
248  return Allocator.Allocate<MachineMemOperand *>(Num);
249}
250
251std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
252MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
253                                    MachineInstr::mmo_iterator End) {
254  // Count the number of load mem refs.
255  unsigned Num = 0;
256  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
257    if ((*I)->isLoad())
258      ++Num;
259
260  // Allocate a new array and populate it with the load information.
261  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
262  unsigned Index = 0;
263  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
264    if ((*I)->isLoad()) {
265      if (!(*I)->isStore())
266        // Reuse the MMO.
267        Result[Index] = *I;
268      else {
269        // Clone the MMO and unset the store flag.
270        MachineMemOperand *JustLoad =
271          getMachineMemOperand((*I)->getValue(),
272                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
273                               (*I)->getOffset(), (*I)->getSize(),
274                               (*I)->getBaseAlignment());
275        Result[Index] = JustLoad;
276      }
277      ++Index;
278    }
279  }
280  return std::make_pair(Result, Result + Num);
281}
282
283std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
284MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
285                                     MachineInstr::mmo_iterator End) {
286  // Count the number of load mem refs.
287  unsigned Num = 0;
288  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
289    if ((*I)->isStore())
290      ++Num;
291
292  // Allocate a new array and populate it with the store information.
293  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
294  unsigned Index = 0;
295  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
296    if ((*I)->isStore()) {
297      if (!(*I)->isLoad())
298        // Reuse the MMO.
299        Result[Index] = *I;
300      else {
301        // Clone the MMO and unset the load flag.
302        MachineMemOperand *JustStore =
303          getMachineMemOperand((*I)->getValue(),
304                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
305                               (*I)->getOffset(), (*I)->getSize(),
306                               (*I)->getBaseAlignment());
307        Result[Index] = JustStore;
308      }
309      ++Index;
310    }
311  }
312  return std::make_pair(Result, Result + Num);
313}
314
315void MachineFunction::dump() const {
316  print(dbgs());
317}
318
319void MachineFunction::print(raw_ostream &OS) const {
320  OS << "# Machine code for function " << Fn->getName() << ":\n";
321
322  // Print Frame Information
323  FrameInfo->print(*this, OS);
324
325  // Print JumpTable Information
326  if (JumpTableInfo)
327    JumpTableInfo->print(OS);
328
329  // Print Constant Pool
330  ConstantPool->print(OS);
331
332  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
333
334  if (RegInfo && !RegInfo->livein_empty()) {
335    OS << "Function Live Ins: ";
336    for (MachineRegisterInfo::livein_iterator
337         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
338      if (TRI)
339        OS << "%" << TRI->getName(I->first);
340      else
341        OS << " %physreg" << I->first;
342
343      if (I->second)
344        OS << " in reg%" << I->second;
345
346      if (llvm::next(I) != E)
347        OS << ", ";
348    }
349    OS << '\n';
350  }
351  if (RegInfo && !RegInfo->liveout_empty()) {
352    OS << "Function Live Outs: ";
353    for (MachineRegisterInfo::liveout_iterator
354         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){
355      if (TRI)
356        OS << '%' << TRI->getName(*I);
357      else
358        OS << "%physreg" << *I;
359
360      if (llvm::next(I) != E)
361        OS << " ";
362    }
363    OS << '\n';
364  }
365
366  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
367    OS << '\n';
368    BB->print(OS);
369  }
370
371  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
372}
373
374namespace llvm {
375  template<>
376  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
377
378  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
379
380    static std::string getGraphName(const MachineFunction *F) {
381      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
382    }
383
384    std::string getNodeLabel(const MachineBasicBlock *Node,
385                             const MachineFunction *Graph) {
386      if (isSimple () && Node->getBasicBlock() &&
387          !Node->getBasicBlock()->getName().empty())
388        return Node->getBasicBlock()->getNameStr() + ":";
389
390      std::string OutStr;
391      {
392        raw_string_ostream OSS(OutStr);
393
394        if (isSimple())
395          OSS << Node->getNumber() << ':';
396        else
397          Node->print(OSS);
398      }
399
400      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
401
402      // Process string output to make it nicer...
403      for (unsigned i = 0; i != OutStr.length(); ++i)
404        if (OutStr[i] == '\n') {                            // Left justify
405          OutStr[i] = '\\';
406          OutStr.insert(OutStr.begin()+i+1, 'l');
407        }
408      return OutStr;
409    }
410  };
411}
412
413void MachineFunction::viewCFG() const
414{
415#ifndef NDEBUG
416  ViewGraph(this, "mf" + getFunction()->getNameStr());
417#else
418  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
419         << "systems with Graphviz or gv!\n";
420#endif // NDEBUG
421}
422
423void MachineFunction::viewCFGOnly() const
424{
425#ifndef NDEBUG
426  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
427#else
428  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
429         << "systems with Graphviz or gv!\n";
430#endif // NDEBUG
431}
432
433/// addLiveIn - Add the specified physical register as a live-in value and
434/// create a corresponding virtual register for it.
435unsigned MachineFunction::addLiveIn(unsigned PReg,
436                                    const TargetRegisterClass *RC) {
437  assert(RC->contains(PReg) && "Not the correct regclass!");
438  unsigned VReg = getRegInfo().createVirtualRegister(RC);
439  getRegInfo().addLiveIn(PReg, VReg);
440  return VReg;
441}
442
443/// getDILocation - Get the DILocation for a given DebugLoc object.
444DILocation MachineFunction::getDILocation(DebugLoc DL) const {
445  unsigned Idx = DL.getIndex();
446  assert(Idx < DebugLocInfo.DebugLocations.size() &&
447         "Invalid index into debug locations!");
448  return DILocation(DebugLocInfo.DebugLocations[Idx]);
449}
450
451
452/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
453/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
454/// normal 'L' label is returned.
455MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
456                                        bool isLinkerPrivate) const {
457  assert(JumpTableInfo && "No jump tables");
458
459  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
460  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
461
462  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
463                                         MAI.getPrivateGlobalPrefix();
464  SmallString<60> Name;
465  raw_svector_ostream(Name)
466    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
467  if (isLinkerPrivate)
468    return Ctx.GetOrCreateSymbol(Name.str());
469  return Ctx.GetOrCreateTemporarySymbol(Name.str());
470}
471
472
473//===----------------------------------------------------------------------===//
474//  MachineFrameInfo implementation
475//===----------------------------------------------------------------------===//
476
477/// CreateFixedObject - Create a new object at a fixed location on the stack.
478/// All fixed objects should be created before other objects are created for
479/// efficiency. By default, fixed objects are immutable. This returns an
480/// index with a negative value.
481///
482int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
483                                        bool Immutable, bool isSS) {
484  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
485  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable,
486                                              isSS));
487  return -++NumFixedObjects;
488}
489
490
491BitVector
492MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
493  assert(MBB && "MBB must be valid");
494  const MachineFunction *MF = MBB->getParent();
495  assert(MF && "MBB must be part of a MachineFunction");
496  const TargetMachine &TM = MF->getTarget();
497  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
498  BitVector BV(TRI->getNumRegs());
499
500  // Before CSI is calculated, no registers are considered pristine. They can be
501  // freely used and PEI will make sure they are saved.
502  if (!isCalleeSavedInfoValid())
503    return BV;
504
505  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
506    BV.set(*CSR);
507
508  // The entry MBB always has all CSRs pristine.
509  if (MBB == &MF->front())
510    return BV;
511
512  // On other MBBs the saved CSRs are not pristine.
513  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
514  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
515         E = CSI.end(); I != E; ++I)
516    BV.reset(I->getReg());
517
518  return BV;
519}
520
521
522void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
523  if (Objects.empty()) return;
524
525  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
526  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
527
528  OS << "Frame Objects:\n";
529
530  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
531    const StackObject &SO = Objects[i];
532    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
533    if (SO.Size == ~0ULL) {
534      OS << "dead\n";
535      continue;
536    }
537    if (SO.Size == 0)
538      OS << "variable sized";
539    else
540      OS << "size=" << SO.Size;
541    OS << ", align=" << SO.Alignment;
542
543    if (i < NumFixedObjects)
544      OS << ", fixed";
545    if (i < NumFixedObjects || SO.SPOffset != -1) {
546      int64_t Off = SO.SPOffset - ValOffset;
547      OS << ", at location [SP";
548      if (Off > 0)
549        OS << "+" << Off;
550      else if (Off < 0)
551        OS << Off;
552      OS << "]";
553    }
554    OS << "\n";
555  }
556}
557
558void MachineFrameInfo::dump(const MachineFunction &MF) const {
559  print(MF, dbgs());
560}
561
562//===----------------------------------------------------------------------===//
563//  MachineJumpTableInfo implementation
564//===----------------------------------------------------------------------===//
565
566/// getEntrySize - Return the size of each entry in the jump table.
567unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
568  // The size of a jump table entry is 4 bytes unless the entry is just the
569  // address of a block, in which case it is the pointer size.
570  switch (getEntryKind()) {
571  case MachineJumpTableInfo::EK_BlockAddress:
572    return TD.getPointerSize();
573  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
574  case MachineJumpTableInfo::EK_LabelDifference32:
575  case MachineJumpTableInfo::EK_Custom32:
576    return 4;
577  case MachineJumpTableInfo::EK_Inline:
578    return 0;
579  }
580  assert(0 && "Unknown jump table encoding!");
581  return ~0;
582}
583
584/// getEntryAlignment - Return the alignment of each entry in the jump table.
585unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
586  // The alignment of a jump table entry is the alignment of int32 unless the
587  // entry is just the address of a block, in which case it is the pointer
588  // alignment.
589  switch (getEntryKind()) {
590  case MachineJumpTableInfo::EK_BlockAddress:
591    return TD.getPointerABIAlignment();
592  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
593  case MachineJumpTableInfo::EK_LabelDifference32:
594  case MachineJumpTableInfo::EK_Custom32:
595    return TD.getABIIntegerTypeAlignment(32);
596  case MachineJumpTableInfo::EK_Inline:
597    return 1;
598  }
599  assert(0 && "Unknown jump table encoding!");
600  return ~0;
601}
602
603/// createJumpTableIndex - Create a new jump table entry in the jump table info.
604///
605unsigned MachineJumpTableInfo::createJumpTableIndex(
606                               const std::vector<MachineBasicBlock*> &DestBBs) {
607  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
608  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
609  return JumpTables.size()-1;
610}
611
612/// getJumpTableIndex - Return the index for an existing jump table entry in
613/// the jump table info.
614unsigned MachineJumpTableInfo::getJumpTableIndex(
615                               const std::vector<MachineBasicBlock*> &DestBBs) {
616  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
617    if (JumpTables[i].MBBs == DestBBs)
618      return i;
619  assert(false && "getJumpTableIndex failed to find matching table");
620  return ~0;
621}
622
623/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
624/// the jump tables to branch to New instead.
625bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
626                                                  MachineBasicBlock *New) {
627  assert(Old != New && "Not making a change?");
628  bool MadeChange = false;
629  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
630    ReplaceMBBInJumpTable(i, Old, New);
631  return MadeChange;
632}
633
634/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
635/// the jump table to branch to New instead.
636bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
637                                                 MachineBasicBlock *Old,
638                                                 MachineBasicBlock *New) {
639  assert(Old != New && "Not making a change?");
640  bool MadeChange = false;
641  MachineJumpTableEntry &JTE = JumpTables[Idx];
642  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
643    if (JTE.MBBs[j] == Old) {
644      JTE.MBBs[j] = New;
645      MadeChange = true;
646    }
647  return MadeChange;
648}
649
650void MachineJumpTableInfo::print(raw_ostream &OS) const {
651  if (JumpTables.empty()) return;
652
653  OS << "Jump Tables:\n";
654
655  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
656    OS << "  jt#" << i << ": ";
657    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
658      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
659  }
660
661  OS << '\n';
662}
663
664void MachineJumpTableInfo::dump() const { print(dbgs()); }
665
666
667//===----------------------------------------------------------------------===//
668//  MachineConstantPool implementation
669//===----------------------------------------------------------------------===//
670
671const Type *MachineConstantPoolEntry::getType() const {
672  if (isMachineConstantPoolEntry())
673    return Val.MachineCPVal->getType();
674  return Val.ConstVal->getType();
675}
676
677
678unsigned MachineConstantPoolEntry::getRelocationInfo() const {
679  if (isMachineConstantPoolEntry())
680    return Val.MachineCPVal->getRelocationInfo();
681  return Val.ConstVal->getRelocationInfo();
682}
683
684MachineConstantPool::~MachineConstantPool() {
685  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
686    if (Constants[i].isMachineConstantPoolEntry())
687      delete Constants[i].Val.MachineCPVal;
688}
689
690/// CanShareConstantPoolEntry - Test whether the given two constants
691/// can be allocated the same constant pool entry.
692static bool CanShareConstantPoolEntry(Constant *A, Constant *B,
693                                      const TargetData *TD) {
694  // Handle the trivial case quickly.
695  if (A == B) return true;
696
697  // If they have the same type but weren't the same constant, quickly
698  // reject them.
699  if (A->getType() == B->getType()) return false;
700
701  // For now, only support constants with the same size.
702  if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
703    return false;
704
705  // If a floating-point value and an integer value have the same encoding,
706  // they can share a constant-pool entry.
707  if (ConstantFP *AFP = dyn_cast<ConstantFP>(A))
708    if (ConstantInt *BI = dyn_cast<ConstantInt>(B))
709      return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
710  if (ConstantFP *BFP = dyn_cast<ConstantFP>(B))
711    if (ConstantInt *AI = dyn_cast<ConstantInt>(A))
712      return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
713
714  // Two vectors can share an entry if each pair of corresponding
715  // elements could.
716  if (ConstantVector *AV = dyn_cast<ConstantVector>(A))
717    if (ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
718      if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
719        return false;
720      for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
721        if (!CanShareConstantPoolEntry(AV->getOperand(i),
722                                       BV->getOperand(i), TD))
723          return false;
724      return true;
725    }
726
727  // TODO: Handle other cases.
728
729  return false;
730}
731
732/// getConstantPoolIndex - Create a new entry in the constant pool or return
733/// an existing one.  User must specify the log2 of the minimum required
734/// alignment for the object.
735///
736unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
737                                                   unsigned Alignment) {
738  assert(Alignment && "Alignment must be specified!");
739  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
740
741  // Check to see if we already have this constant.
742  //
743  // FIXME, this could be made much more efficient for large constant pools.
744  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
745    if (!Constants[i].isMachineConstantPoolEntry() &&
746        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
747      if ((unsigned)Constants[i].getAlignment() < Alignment)
748        Constants[i].Alignment = Alignment;
749      return i;
750    }
751
752  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
753  return Constants.size()-1;
754}
755
756unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
757                                                   unsigned Alignment) {
758  assert(Alignment && "Alignment must be specified!");
759  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
760
761  // Check to see if we already have this constant.
762  //
763  // FIXME, this could be made much more efficient for large constant pools.
764  int Idx = V->getExistingMachineCPValue(this, Alignment);
765  if (Idx != -1)
766    return (unsigned)Idx;
767
768  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
769  return Constants.size()-1;
770}
771
772void MachineConstantPool::print(raw_ostream &OS) const {
773  if (Constants.empty()) return;
774
775  OS << "Constant Pool:\n";
776  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
777    OS << "  cp#" << i << ": ";
778    if (Constants[i].isMachineConstantPoolEntry())
779      Constants[i].Val.MachineCPVal->print(OS);
780    else
781      OS << *(Value*)Constants[i].Val.ConstVal;
782    OS << ", align=" << Constants[i].getAlignment();
783    OS << "\n";
784  }
785}
786
787void MachineConstantPool::dump() const { print(dbgs()); }
788