MachineFunction.cpp revision 6b2760759b23b8b96beb43966b9b8088e832efc7 
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/CodeGen/MachineFunction.h"
17#include "llvm/Function.h"
18#include "llvm/CodeGen/MachineConstantPool.h"
19#include "llvm/CodeGen/MachineFunctionPass.h"
20#include "llvm/CodeGen/MachineFrameInfo.h"
21#include "llvm/CodeGen/MachineInstr.h"
22#include "llvm/CodeGen/MachineJumpTableInfo.h"
23#include "llvm/CodeGen/MachineModuleInfo.h"
24#include "llvm/CodeGen/MachineRegisterInfo.h"
25#include "llvm/CodeGen/Passes.h"
26#include "llvm/MC/MCAsmInfo.h"
27#include "llvm/MC/MCContext.h"
28#include "llvm/Analysis/ConstantFolding.h"
29#include "llvm/Analysis/DebugInfo.h"
30#include "llvm/Support/Debug.h"
31#include "llvm/Target/TargetData.h"
32#include "llvm/Target/TargetLowering.h"
33#include "llvm/Target/TargetMachine.h"
34#include "llvm/Target/TargetFrameLowering.h"
35#include "llvm/ADT/SmallString.h"
36#include "llvm/ADT/STLExtras.h"
37#include "llvm/Support/GraphWriter.h"
38#include "llvm/Support/raw_ostream.h"
39using namespace llvm;
40
41//===----------------------------------------------------------------------===//
42// MachineFunction implementation
43//===----------------------------------------------------------------------===//
44
45// Out of line virtual method.
46MachineFunctionInfo::~MachineFunctionInfo() {}
47
48void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
49  MBB->getParent()->DeleteMachineBasicBlock(MBB);
50}
51
52MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
53                                 unsigned FunctionNum, MachineModuleInfo &mmi,
54                                 GCModuleInfo* gmi)
55  : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
56  if (TM.getRegisterInfo())
57    RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
58  else
59    RegInfo = 0;
60  MFInfo = 0;
61  FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering());
62  if (Fn->hasFnAttr(Attribute::StackAlignment))
63    FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
64        Fn->getAttributes().getFnAttributes()));
65  ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
66  Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
67  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
68  if (!Fn->hasFnAttr(Attribute::OptimizeForSize))
69    Alignment = std::max(Alignment,
70                         TM.getTargetLowering()->getPrefFunctionAlignment());
71  FunctionNumber = FunctionNum;
72  JumpTableInfo = 0;
73}
74
75MachineFunction::~MachineFunction() {
76  BasicBlocks.clear();
77  InstructionRecycler.clear(Allocator);
78  BasicBlockRecycler.clear(Allocator);
79  if (RegInfo) {
80    RegInfo->~MachineRegisterInfo();
81    Allocator.Deallocate(RegInfo);
82  }
83  if (MFInfo) {
84    MFInfo->~MachineFunctionInfo();
85    Allocator.Deallocate(MFInfo);
86  }
87  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
88  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
89
90  if (JumpTableInfo) {
91    JumpTableInfo->~MachineJumpTableInfo();
92    Allocator.Deallocate(JumpTableInfo);
93  }
94}
95
96/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
97/// does already exist, allocate one.
98MachineJumpTableInfo *MachineFunction::
99getOrCreateJumpTableInfo(unsigned EntryKind) {
100  if (JumpTableInfo) return JumpTableInfo;
101
102  JumpTableInfo = new (Allocator)
103    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
104  return JumpTableInfo;
105}
106
107/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
108/// recomputes them.  This guarantees that the MBB numbers are sequential,
109/// dense, and match the ordering of the blocks within the function.  If a
110/// specific MachineBasicBlock is specified, only that block and those after
111/// it are renumbered.
112void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
113  if (empty()) { MBBNumbering.clear(); return; }
114  MachineFunction::iterator MBBI, E = end();
115  if (MBB == 0)
116    MBBI = begin();
117  else
118    MBBI = MBB;
119
120  // Figure out the block number this should have.
121  unsigned BlockNo = 0;
122  if (MBBI != begin())
123    BlockNo = prior(MBBI)->getNumber()+1;
124
125  for (; MBBI != E; ++MBBI, ++BlockNo) {
126    if (MBBI->getNumber() != (int)BlockNo) {
127      // Remove use of the old number.
128      if (MBBI->getNumber() != -1) {
129        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
130               "MBB number mismatch!");
131        MBBNumbering[MBBI->getNumber()] = 0;
132      }
133
134      // If BlockNo is already taken, set that block's number to -1.
135      if (MBBNumbering[BlockNo])
136        MBBNumbering[BlockNo]->setNumber(-1);
137
138      MBBNumbering[BlockNo] = MBBI;
139      MBBI->setNumber(BlockNo);
140    }
141  }
142
143  // Okay, all the blocks are renumbered.  If we have compactified the block
144  // numbering, shrink MBBNumbering now.
145  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
146  MBBNumbering.resize(BlockNo);
147}
148
149/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
150/// of `new MachineInstr'.
151///
152MachineInstr *
153MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
154                                    DebugLoc DL, bool NoImp) {
155  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
156    MachineInstr(MCID, DL, NoImp);
157}
158
159/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
160/// 'Orig' instruction, identical in all ways except the instruction
161/// has no parent, prev, or next.
162///
163MachineInstr *
164MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
165  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
166             MachineInstr(*this, *Orig);
167}
168
169/// DeleteMachineInstr - Delete the given MachineInstr.
170///
171void
172MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
173  MI->~MachineInstr();
174  InstructionRecycler.Deallocate(Allocator, MI);
175}
176
177/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
178/// instead of `new MachineBasicBlock'.
179///
180MachineBasicBlock *
181MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
182  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
183             MachineBasicBlock(*this, bb);
184}
185
186/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
187///
188void
189MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
190  assert(MBB->getParent() == this && "MBB parent mismatch!");
191  MBB->~MachineBasicBlock();
192  BasicBlockRecycler.Deallocate(Allocator, MBB);
193}
194
195MachineMemOperand *
196MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
197                                      uint64_t s, unsigned base_alignment,
198                                      const MDNode *TBAAInfo) {
199  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
200                                           TBAAInfo);
201}
202
203MachineMemOperand *
204MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
205                                      int64_t Offset, uint64_t Size) {
206  return new (Allocator)
207             MachineMemOperand(MachinePointerInfo(MMO->getValue(),
208                                                  MMO->getOffset()+Offset),
209                               MMO->getFlags(), Size,
210                               MMO->getBaseAlignment(), 0);
211}
212
213MachineInstr::mmo_iterator
214MachineFunction::allocateMemRefsArray(unsigned long Num) {
215  return Allocator.Allocate<MachineMemOperand *>(Num);
216}
217
218std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
219MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
220                                    MachineInstr::mmo_iterator End) {
221  // Count the number of load mem refs.
222  unsigned Num = 0;
223  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
224    if ((*I)->isLoad())
225      ++Num;
226
227  // Allocate a new array and populate it with the load information.
228  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
229  unsigned Index = 0;
230  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
231    if ((*I)->isLoad()) {
232      if (!(*I)->isStore())
233        // Reuse the MMO.
234        Result[Index] = *I;
235      else {
236        // Clone the MMO and unset the store flag.
237        MachineMemOperand *JustLoad =
238          getMachineMemOperand((*I)->getPointerInfo(),
239                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
240                               (*I)->getSize(), (*I)->getBaseAlignment(),
241                               (*I)->getTBAAInfo());
242        Result[Index] = JustLoad;
243      }
244      ++Index;
245    }
246  }
247  return std::make_pair(Result, Result + Num);
248}
249
250std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
251MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
252                                     MachineInstr::mmo_iterator End) {
253  // Count the number of load mem refs.
254  unsigned Num = 0;
255  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
256    if ((*I)->isStore())
257      ++Num;
258
259  // Allocate a new array and populate it with the store information.
260  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
261  unsigned Index = 0;
262  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
263    if ((*I)->isStore()) {
264      if (!(*I)->isLoad())
265        // Reuse the MMO.
266        Result[Index] = *I;
267      else {
268        // Clone the MMO and unset the load flag.
269        MachineMemOperand *JustStore =
270          getMachineMemOperand((*I)->getPointerInfo(),
271                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
272                               (*I)->getSize(), (*I)->getBaseAlignment(),
273                               (*I)->getTBAAInfo());
274        Result[Index] = JustStore;
275      }
276      ++Index;
277    }
278  }
279  return std::make_pair(Result, Result + Num);
280}
281
282void MachineFunction::dump() const {
283  print(dbgs());
284}
285
286void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
287  OS << "# Machine code for function " << Fn->getName() << ":\n";
288
289  // Print Frame Information
290  FrameInfo->print(*this, OS);
291
292  // Print JumpTable Information
293  if (JumpTableInfo)
294    JumpTableInfo->print(OS);
295
296  // Print Constant Pool
297  ConstantPool->print(OS);
298
299  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
300
301  if (RegInfo && !RegInfo->livein_empty()) {
302    OS << "Function Live Ins: ";
303    for (MachineRegisterInfo::livein_iterator
304         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
305      OS << PrintReg(I->first, TRI);
306      if (I->second)
307        OS << " in " << PrintReg(I->second, TRI);
308      if (llvm::next(I) != E)
309        OS << ", ";
310    }
311    OS << '\n';
312  }
313  if (RegInfo && !RegInfo->liveout_empty()) {
314    OS << "Function Live Outs:";
315    for (MachineRegisterInfo::liveout_iterator
316         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
317      OS << ' ' << PrintReg(*I, TRI);
318    OS << '\n';
319  }
320
321  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
322    OS << '\n';
323    BB->print(OS, Indexes);
324  }
325
326  OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
327}
328
329namespace llvm {
330  template<>
331  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
332
333  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
334
335    static std::string getGraphName(const MachineFunction *F) {
336      return "CFG for '" + F->getFunction()->getName().str() + "' function";
337    }
338
339    std::string getNodeLabel(const MachineBasicBlock *Node,
340                             const MachineFunction *Graph) {
341      std::string OutStr;
342      {
343        raw_string_ostream OSS(OutStr);
344
345        if (isSimple()) {
346          OSS << "BB#" << Node->getNumber();
347          if (const BasicBlock *BB = Node->getBasicBlock())
348            OSS << ": " << BB->getName();
349        } else
350          Node->print(OSS);
351      }
352
353      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
354
355      // Process string output to make it nicer...
356      for (unsigned i = 0; i != OutStr.length(); ++i)
357        if (OutStr[i] == '\n') {                            // Left justify
358          OutStr[i] = '\\';
359          OutStr.insert(OutStr.begin()+i+1, 'l');
360        }
361      return OutStr;
362    }
363  };
364}
365
366void MachineFunction::viewCFG() const
367{
368#ifndef NDEBUG
369  ViewGraph(this, "mf" + getFunction()->getName());
370#else
371  errs() << "MachineFunction::viewCFG is only available in debug builds on "
372         << "systems with Graphviz or gv!\n";
373#endif // NDEBUG
374}
375
376void MachineFunction::viewCFGOnly() const
377{
378#ifndef NDEBUG
379  ViewGraph(this, "mf" + getFunction()->getName(), true);
380#else
381  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
382         << "systems with Graphviz or gv!\n";
383#endif // NDEBUG
384}
385
386/// addLiveIn - Add the specified physical register as a live-in value and
387/// create a corresponding virtual register for it.
388unsigned MachineFunction::addLiveIn(unsigned PReg,
389                                    const TargetRegisterClass *RC) {
390  MachineRegisterInfo &MRI = getRegInfo();
391  unsigned VReg = MRI.getLiveInVirtReg(PReg);
392  if (VReg) {
393    assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
394    return VReg;
395  }
396  VReg = MRI.createVirtualRegister(RC);
397  MRI.addLiveIn(PReg, VReg);
398  return VReg;
399}
400
401/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
402/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
403/// normal 'L' label is returned.
404MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
405                                        bool isLinkerPrivate) const {
406  assert(JumpTableInfo && "No jump tables");
407
408  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
409  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
410
411  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
412                                         MAI.getPrivateGlobalPrefix();
413  SmallString<60> Name;
414  raw_svector_ostream(Name)
415    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
416  return Ctx.GetOrCreateSymbol(Name.str());
417}
418
419/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
420/// base.
421MCSymbol *MachineFunction::getPICBaseSymbol() const {
422  const MCAsmInfo &MAI = *Target.getMCAsmInfo();
423  return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
424                               Twine(getFunctionNumber())+"$pb");
425}
426
427//===----------------------------------------------------------------------===//
428//  MachineFrameInfo implementation
429//===----------------------------------------------------------------------===//
430
431/// CreateFixedObject - Create a new object at a fixed location on the stack.
432/// All fixed objects should be created before other objects are created for
433/// efficiency. By default, fixed objects are immutable. This returns an
434/// index with a negative value.
435///
436int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
437                                        bool Immutable) {
438  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
439  // The alignment of the frame index can be determined from its offset from
440  // the incoming frame position.  If the frame object is at offset 32 and
441  // the stack is guaranteed to be 16-byte aligned, then we know that the
442  // object is 16-byte aligned.
443  unsigned StackAlign = TFI.getStackAlignment();
444  unsigned Align = MinAlign(SPOffset, StackAlign);
445  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
446                                              /*isSS*/false, false));
447  return -++NumFixedObjects;
448}
449
450
451BitVector
452MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
453  assert(MBB && "MBB must be valid");
454  const MachineFunction *MF = MBB->getParent();
455  assert(MF && "MBB must be part of a MachineFunction");
456  const TargetMachine &TM = MF->getTarget();
457  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
458  BitVector BV(TRI->getNumRegs());
459
460  // Before CSI is calculated, no registers are considered pristine. They can be
461  // freely used and PEI will make sure they are saved.
462  if (!isCalleeSavedInfoValid())
463    return BV;
464
465  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
466    BV.set(*CSR);
467
468  // The entry MBB always has all CSRs pristine.
469  if (MBB == &MF->front())
470    return BV;
471
472  // On other MBBs the saved CSRs are not pristine.
473  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
474  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
475         E = CSI.end(); I != E; ++I)
476    BV.reset(I->getReg());
477
478  return BV;
479}
480
481
482void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
483  if (Objects.empty()) return;
484
485  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
486  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
487
488  OS << "Frame Objects:\n";
489
490  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
491    const StackObject &SO = Objects[i];
492    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
493    if (SO.Size == ~0ULL) {
494      OS << "dead\n";
495      continue;
496    }
497    if (SO.Size == 0)
498      OS << "variable sized";
499    else
500      OS << "size=" << SO.Size;
501    OS << ", align=" << SO.Alignment;
502
503    if (i < NumFixedObjects)
504      OS << ", fixed";
505    if (i < NumFixedObjects || SO.SPOffset != -1) {
506      int64_t Off = SO.SPOffset - ValOffset;
507      OS << ", at location [SP";
508      if (Off > 0)
509        OS << "+" << Off;
510      else if (Off < 0)
511        OS << Off;
512      OS << "]";
513    }
514    OS << "\n";
515  }
516}
517
518void MachineFrameInfo::dump(const MachineFunction &MF) const {
519  print(MF, dbgs());
520}
521
522//===----------------------------------------------------------------------===//
523//  MachineJumpTableInfo implementation
524//===----------------------------------------------------------------------===//
525
526/// getEntrySize - Return the size of each entry in the jump table.
527unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
528  // The size of a jump table entry is 4 bytes unless the entry is just the
529  // address of a block, in which case it is the pointer size.
530  switch (getEntryKind()) {
531  case MachineJumpTableInfo::EK_BlockAddress:
532    return TD.getPointerSize();
533  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
534  case MachineJumpTableInfo::EK_LabelDifference32:
535  case MachineJumpTableInfo::EK_Custom32:
536    return 4;
537  case MachineJumpTableInfo::EK_Inline:
538    return 0;
539  }
540  assert(0 && "Unknown jump table encoding!");
541  return ~0;
542}
543
544/// getEntryAlignment - Return the alignment of each entry in the jump table.
545unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
546  // The alignment of a jump table entry is the alignment of int32 unless the
547  // entry is just the address of a block, in which case it is the pointer
548  // alignment.
549  switch (getEntryKind()) {
550  case MachineJumpTableInfo::EK_BlockAddress:
551    return TD.getPointerABIAlignment();
552  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
553  case MachineJumpTableInfo::EK_LabelDifference32:
554  case MachineJumpTableInfo::EK_Custom32:
555    return TD.getABIIntegerTypeAlignment(32);
556  case MachineJumpTableInfo::EK_Inline:
557    return 1;
558  }
559  assert(0 && "Unknown jump table encoding!");
560  return ~0;
561}
562
563/// createJumpTableIndex - Create a new jump table entry in the jump table info.
564///
565unsigned MachineJumpTableInfo::createJumpTableIndex(
566                               const std::vector<MachineBasicBlock*> &DestBBs) {
567  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
568  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
569  return JumpTables.size()-1;
570}
571
572/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
573/// the jump tables to branch to New instead.
574bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
575                                                  MachineBasicBlock *New) {
576  assert(Old != New && "Not making a change?");
577  bool MadeChange = false;
578  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
579    ReplaceMBBInJumpTable(i, Old, New);
580  return MadeChange;
581}
582
583/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
584/// the jump table to branch to New instead.
585bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
586                                                 MachineBasicBlock *Old,
587                                                 MachineBasicBlock *New) {
588  assert(Old != New && "Not making a change?");
589  bool MadeChange = false;
590  MachineJumpTableEntry &JTE = JumpTables[Idx];
591  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
592    if (JTE.MBBs[j] == Old) {
593      JTE.MBBs[j] = New;
594      MadeChange = true;
595    }
596  return MadeChange;
597}
598
599void MachineJumpTableInfo::print(raw_ostream &OS) const {
600  if (JumpTables.empty()) return;
601
602  OS << "Jump Tables:\n";
603
604  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
605    OS << "  jt#" << i << ": ";
606    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
607      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
608  }
609
610  OS << '\n';
611}
612
613void MachineJumpTableInfo::dump() const { print(dbgs()); }
614
615
616//===----------------------------------------------------------------------===//
617//  MachineConstantPool implementation
618//===----------------------------------------------------------------------===//
619
620void MachineConstantPoolValue::anchor() { }
621
622Type *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  // We can't handle structs or arrays.
657  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
658      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
659    return false;
660
661  // For now, only support constants with the same size.
662  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
663  if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
664      StoreSize > 128)
665    return false;
666
667  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
668
669  // Try constant folding a bitcast of both instructions to an integer.  If we
670  // get two identical ConstantInt's, then we are good to share them.  We use
671  // the constant folding APIs to do this so that we get the benefit of
672  // TargetData.
673  if (isa<PointerType>(A->getType()))
674    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
675                                 const_cast<Constant*>(A), TD);
676  else if (A->getType() != IntTy)
677    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
678                                 const_cast<Constant*>(A), TD);
679  if (isa<PointerType>(B->getType()))
680    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
681                                 const_cast<Constant*>(B), TD);
682  else if (B->getType() != IntTy)
683    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
684                                 const_cast<Constant*>(B), TD);
685
686  return A == B;
687}
688
689/// getConstantPoolIndex - Create a new entry in the constant pool or return
690/// an existing one.  User must specify the log2 of the minimum required
691/// alignment for the object.
692///
693unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
694                                                   unsigned Alignment) {
695  assert(Alignment && "Alignment must be specified!");
696  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
697
698  // Check to see if we already have this constant.
699  //
700  // FIXME, this could be made much more efficient for large constant pools.
701  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
702    if (!Constants[i].isMachineConstantPoolEntry() &&
703        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
704      if ((unsigned)Constants[i].getAlignment() < Alignment)
705        Constants[i].Alignment = Alignment;
706      return i;
707    }
708
709  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
710  return Constants.size()-1;
711}
712
713unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
714                                                   unsigned Alignment) {
715  assert(Alignment && "Alignment must be specified!");
716  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
717
718  // Check to see if we already have this constant.
719  //
720  // FIXME, this could be made much more efficient for large constant pools.
721  int Idx = V->getExistingMachineCPValue(this, Alignment);
722  if (Idx != -1) {
723    MachineCPVsSharingEntries.insert(V);
724    return (unsigned)Idx;
725  }
726
727  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
728  return Constants.size()-1;
729}
730
731void MachineConstantPool::print(raw_ostream &OS) const {
732  if (Constants.empty()) return;
733
734  OS << "Constant Pool:\n";
735  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
736    OS << "  cp#" << i << ": ";
737    if (Constants[i].isMachineConstantPoolEntry())
738      Constants[i].Val.MachineCPVal->print(OS);
739    else
740      OS << *(Value*)Constants[i].Val.ConstVal;
741    OS << ", align=" << Constants[i].getAlignment();
742    OS << "\n";
743  }
744}
745
746void MachineConstantPool::dump() const { print(dbgs()); }
747