MachineFunction.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
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/ADT/STLExtras.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/Analysis/ConstantFolding.h"
20#include "llvm/CodeGen/MachineConstantPool.h"
21#include "llvm/CodeGen/MachineFrameInfo.h"
22#include "llvm/CodeGen/MachineFunctionPass.h"
23#include "llvm/CodeGen/MachineInstr.h"
24#include "llvm/CodeGen/MachineJumpTableInfo.h"
25#include "llvm/CodeGen/MachineModuleInfo.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/Passes.h"
28#include "llvm/IR/DataLayout.h"
29#include "llvm/IR/DebugInfo.h"
30#include "llvm/IR/Function.h"
31#include "llvm/MC/MCAsmInfo.h"
32#include "llvm/MC/MCContext.h"
33#include "llvm/Support/Debug.h"
34#include "llvm/Support/GraphWriter.h"
35#include "llvm/Support/raw_ostream.h"
36#include "llvm/Target/TargetFrameLowering.h"
37#include "llvm/Target/TargetLowering.h"
38#include "llvm/Target/TargetMachine.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);
58  else
59    RegInfo = 0;
60
61  MFInfo = 0;
62  FrameInfo =
63    new (Allocator) MachineFrameInfo(TM,!F->hasFnAttribute("no-realign-stack"));
64
65  if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
66                                       Attribute::StackAlignment))
67    FrameInfo->ensureMaxAlignment(Fn->getAttributes().
68                                getStackAlignment(AttributeSet::FunctionIndex));
69
70  ConstantPool = new (Allocator) MachineConstantPool(TM);
71  Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
72
73  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
74  if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
75                                        Attribute::OptimizeForSize))
76    Alignment = std::max(Alignment,
77                         TM.getTargetLowering()->getPrefFunctionAlignment());
78
79  FunctionNumber = FunctionNum;
80  JumpTableInfo = 0;
81}
82
83MachineFunction::~MachineFunction() {
84  // Don't call destructors on MachineInstr and MachineOperand. All of their
85  // memory comes from the BumpPtrAllocator which is about to be purged.
86  //
87  // Do call MachineBasicBlock destructors, it contains std::vectors.
88  for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
89    I->Insts.clearAndLeakNodesUnsafely();
90
91  InstructionRecycler.clear(Allocator);
92  OperandRecycler.clear(Allocator);
93  BasicBlockRecycler.clear(Allocator);
94  if (RegInfo) {
95    RegInfo->~MachineRegisterInfo();
96    Allocator.Deallocate(RegInfo);
97  }
98  if (MFInfo) {
99    MFInfo->~MachineFunctionInfo();
100    Allocator.Deallocate(MFInfo);
101  }
102
103  FrameInfo->~MachineFrameInfo();
104  Allocator.Deallocate(FrameInfo);
105
106  ConstantPool->~MachineConstantPool();
107  Allocator.Deallocate(ConstantPool);
108
109  if (JumpTableInfo) {
110    JumpTableInfo->~MachineJumpTableInfo();
111    Allocator.Deallocate(JumpTableInfo);
112  }
113}
114
115/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
116/// does already exist, allocate one.
117MachineJumpTableInfo *MachineFunction::
118getOrCreateJumpTableInfo(unsigned EntryKind) {
119  if (JumpTableInfo) return JumpTableInfo;
120
121  JumpTableInfo = new (Allocator)
122    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
123  return JumpTableInfo;
124}
125
126/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
127/// recomputes them.  This guarantees that the MBB numbers are sequential,
128/// dense, and match the ordering of the blocks within the function.  If a
129/// specific MachineBasicBlock is specified, only that block and those after
130/// it are renumbered.
131void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
132  if (empty()) { MBBNumbering.clear(); return; }
133  MachineFunction::iterator MBBI, E = end();
134  if (MBB == 0)
135    MBBI = begin();
136  else
137    MBBI = MBB;
138
139  // Figure out the block number this should have.
140  unsigned BlockNo = 0;
141  if (MBBI != begin())
142    BlockNo = std::prev(MBBI)->getNumber() + 1;
143
144  for (; MBBI != E; ++MBBI, ++BlockNo) {
145    if (MBBI->getNumber() != (int)BlockNo) {
146      // Remove use of the old number.
147      if (MBBI->getNumber() != -1) {
148        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
149               "MBB number mismatch!");
150        MBBNumbering[MBBI->getNumber()] = 0;
151      }
152
153      // If BlockNo is already taken, set that block's number to -1.
154      if (MBBNumbering[BlockNo])
155        MBBNumbering[BlockNo]->setNumber(-1);
156
157      MBBNumbering[BlockNo] = MBBI;
158      MBBI->setNumber(BlockNo);
159    }
160  }
161
162  // Okay, all the blocks are renumbered.  If we have compactified the block
163  // numbering, shrink MBBNumbering now.
164  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
165  MBBNumbering.resize(BlockNo);
166}
167
168/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
169/// of `new MachineInstr'.
170///
171MachineInstr *
172MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
173                                    DebugLoc DL, bool NoImp) {
174  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
175    MachineInstr(*this, MCID, DL, NoImp);
176}
177
178/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
179/// 'Orig' instruction, identical in all ways except the instruction
180/// has no parent, prev, or next.
181///
182MachineInstr *
183MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
184  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
185             MachineInstr(*this, *Orig);
186}
187
188/// DeleteMachineInstr - Delete the given MachineInstr.
189///
190/// This function also serves as the MachineInstr destructor - the real
191/// ~MachineInstr() destructor must be empty.
192void
193MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
194  // Strip it for parts. The operand array and the MI object itself are
195  // independently recyclable.
196  if (MI->Operands)
197    deallocateOperandArray(MI->CapOperands, MI->Operands);
198  // Don't call ~MachineInstr() which must be trivial anyway because
199  // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
200  // destructors.
201  InstructionRecycler.Deallocate(Allocator, MI);
202}
203
204/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
205/// instead of `new MachineBasicBlock'.
206///
207MachineBasicBlock *
208MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
209  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
210             MachineBasicBlock(*this, bb);
211}
212
213/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
214///
215void
216MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
217  assert(MBB->getParent() == this && "MBB parent mismatch!");
218  MBB->~MachineBasicBlock();
219  BasicBlockRecycler.Deallocate(Allocator, MBB);
220}
221
222MachineMemOperand *
223MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
224                                      uint64_t s, unsigned base_alignment,
225                                      const MDNode *TBAAInfo,
226                                      const MDNode *Ranges) {
227  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
228                                           TBAAInfo, Ranges);
229}
230
231MachineMemOperand *
232MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
233                                      int64_t Offset, uint64_t Size) {
234  return new (Allocator)
235             MachineMemOperand(MachinePointerInfo(MMO->getValue(),
236                                                  MMO->getOffset()+Offset),
237                               MMO->getFlags(), Size,
238                               MMO->getBaseAlignment(), 0);
239}
240
241MachineInstr::mmo_iterator
242MachineFunction::allocateMemRefsArray(unsigned long Num) {
243  return Allocator.Allocate<MachineMemOperand *>(Num);
244}
245
246std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
247MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
248                                    MachineInstr::mmo_iterator End) {
249  // Count the number of load mem refs.
250  unsigned Num = 0;
251  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
252    if ((*I)->isLoad())
253      ++Num;
254
255  // Allocate a new array and populate it with the load information.
256  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
257  unsigned Index = 0;
258  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
259    if ((*I)->isLoad()) {
260      if (!(*I)->isStore())
261        // Reuse the MMO.
262        Result[Index] = *I;
263      else {
264        // Clone the MMO and unset the store flag.
265        MachineMemOperand *JustLoad =
266          getMachineMemOperand((*I)->getPointerInfo(),
267                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
268                               (*I)->getSize(), (*I)->getBaseAlignment(),
269                               (*I)->getTBAAInfo());
270        Result[Index] = JustLoad;
271      }
272      ++Index;
273    }
274  }
275  return std::make_pair(Result, Result + Num);
276}
277
278std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
279MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
280                                     MachineInstr::mmo_iterator End) {
281  // Count the number of load mem refs.
282  unsigned Num = 0;
283  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
284    if ((*I)->isStore())
285      ++Num;
286
287  // Allocate a new array and populate it with the store information.
288  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
289  unsigned Index = 0;
290  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
291    if ((*I)->isStore()) {
292      if (!(*I)->isLoad())
293        // Reuse the MMO.
294        Result[Index] = *I;
295      else {
296        // Clone the MMO and unset the load flag.
297        MachineMemOperand *JustStore =
298          getMachineMemOperand((*I)->getPointerInfo(),
299                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
300                               (*I)->getSize(), (*I)->getBaseAlignment(),
301                               (*I)->getTBAAInfo());
302        Result[Index] = JustStore;
303      }
304      ++Index;
305    }
306  }
307  return std::make_pair(Result, Result + Num);
308}
309
310#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
311void MachineFunction::dump() const {
312  print(dbgs());
313}
314#endif
315
316StringRef MachineFunction::getName() const {
317  assert(getFunction() && "No function!");
318  return getFunction()->getName();
319}
320
321void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
322  OS << "# Machine code for function " << getName() << ": ";
323  if (RegInfo) {
324    OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
325    if (!RegInfo->tracksLiveness())
326      OS << ", not tracking liveness";
327  }
328  OS << '\n';
329
330  // Print Frame Information
331  FrameInfo->print(*this, OS);
332
333  // Print JumpTable Information
334  if (JumpTableInfo)
335    JumpTableInfo->print(OS);
336
337  // Print Constant Pool
338  ConstantPool->print(OS);
339
340  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
341
342  if (RegInfo && !RegInfo->livein_empty()) {
343    OS << "Function Live Ins: ";
344    for (MachineRegisterInfo::livein_iterator
345         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
346      OS << PrintReg(I->first, TRI);
347      if (I->second)
348        OS << " in " << PrintReg(I->second, TRI);
349      if (std::next(I) != E)
350        OS << ", ";
351    }
352    OS << '\n';
353  }
354
355  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
356    OS << '\n';
357    BB->print(OS, Indexes);
358  }
359
360  OS << "\n# End machine code for function " << getName() << ".\n\n";
361}
362
363namespace llvm {
364  template<>
365  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
366
367  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
368
369    static std::string getGraphName(const MachineFunction *F) {
370      return "CFG for '" + F->getName().str() + "' function";
371    }
372
373    std::string getNodeLabel(const MachineBasicBlock *Node,
374                             const MachineFunction *Graph) {
375      std::string OutStr;
376      {
377        raw_string_ostream OSS(OutStr);
378
379        if (isSimple()) {
380          OSS << "BB#" << Node->getNumber();
381          if (const BasicBlock *BB = Node->getBasicBlock())
382            OSS << ": " << BB->getName();
383        } else
384          Node->print(OSS);
385      }
386
387      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
388
389      // Process string output to make it nicer...
390      for (unsigned i = 0; i != OutStr.length(); ++i)
391        if (OutStr[i] == '\n') {                            // Left justify
392          OutStr[i] = '\\';
393          OutStr.insert(OutStr.begin()+i+1, 'l');
394        }
395      return OutStr;
396    }
397  };
398}
399
400void MachineFunction::viewCFG() const
401{
402#ifndef NDEBUG
403  ViewGraph(this, "mf" + getName());
404#else
405  errs() << "MachineFunction::viewCFG is only available in debug builds on "
406         << "systems with Graphviz or gv!\n";
407#endif // NDEBUG
408}
409
410void MachineFunction::viewCFGOnly() const
411{
412#ifndef NDEBUG
413  ViewGraph(this, "mf" + getName(), true);
414#else
415  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
416         << "systems with Graphviz or gv!\n";
417#endif // NDEBUG
418}
419
420/// addLiveIn - Add the specified physical register as a live-in value and
421/// create a corresponding virtual register for it.
422unsigned MachineFunction::addLiveIn(unsigned PReg,
423                                    const TargetRegisterClass *RC) {
424  MachineRegisterInfo &MRI = getRegInfo();
425  unsigned VReg = MRI.getLiveInVirtReg(PReg);
426  if (VReg) {
427    const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
428    (void)VRegRC;
429    // A physical register can be added several times.
430    // Between two calls, the register class of the related virtual register
431    // may have been constrained to match some operation constraints.
432    // In that case, check that the current register class includes the
433    // physical register and is a sub class of the specified RC.
434    assert((VRegRC == RC || (VRegRC->contains(PReg) &&
435                             RC->hasSubClassEq(VRegRC))) &&
436            "Register class mismatch!");
437    return VReg;
438  }
439  VReg = MRI.createVirtualRegister(RC);
440  MRI.addLiveIn(PReg, VReg);
441  return VReg;
442}
443
444/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
445/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
446/// normal 'L' label is returned.
447MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
448                                        bool isLinkerPrivate) const {
449  const DataLayout *DL = getTarget().getDataLayout();
450  assert(JumpTableInfo && "No jump tables");
451  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
452
453  const char *Prefix = isLinkerPrivate ? DL->getLinkerPrivateGlobalPrefix() :
454                                         DL->getPrivateGlobalPrefix();
455  SmallString<60> Name;
456  raw_svector_ostream(Name)
457    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
458  return Ctx.GetOrCreateSymbol(Name.str());
459}
460
461/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
462/// base.
463MCSymbol *MachineFunction::getPICBaseSymbol() const {
464  const DataLayout *DL = getTarget().getDataLayout();
465  return Ctx.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
466                               Twine(getFunctionNumber())+"$pb");
467}
468
469//===----------------------------------------------------------------------===//
470//  MachineFrameInfo implementation
471//===----------------------------------------------------------------------===//
472
473const TargetFrameLowering *MachineFrameInfo::getFrameLowering() const {
474  return TM.getFrameLowering();
475}
476
477/// ensureMaxAlignment - Make sure the function is at least Align bytes
478/// aligned.
479void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
480  if (!getFrameLowering()->isStackRealignable() || !RealignOption)
481    assert(Align <= getFrameLowering()->getStackAlignment() &&
482           "For targets without stack realignment, Align is out of limit!");
483  if (MaxAlignment < Align) MaxAlignment = Align;
484}
485
486/// clampStackAlignment - Clamp the alignment if requested and emit a warning.
487static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
488                                           unsigned StackAlign) {
489  if (!ShouldClamp || Align <= StackAlign)
490    return Align;
491  DEBUG(dbgs() << "Warning: requested alignment " << Align
492               << " exceeds the stack alignment " << StackAlign
493               << " when stack realignment is off" << '\n');
494  return StackAlign;
495}
496
497/// CreateStackObject - Create a new statically sized stack object, returning
498/// a nonnegative identifier to represent it.
499///
500int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
501                      bool isSS, const AllocaInst *Alloca) {
502  assert(Size != 0 && "Cannot allocate zero size stack objects!");
503  Alignment =
504    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
505                          !RealignOption,
506                        Alignment, getFrameLowering()->getStackAlignment());
507  Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, Alloca));
508  int Index = (int)Objects.size() - NumFixedObjects - 1;
509  assert(Index >= 0 && "Bad frame index!");
510  ensureMaxAlignment(Alignment);
511  return Index;
512}
513
514/// CreateSpillStackObject - Create a new statically sized stack object that
515/// represents a spill slot, returning a nonnegative identifier to represent
516/// it.
517///
518int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
519                                             unsigned Alignment) {
520  Alignment =
521    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
522                          !RealignOption,
523                        Alignment, getFrameLowering()->getStackAlignment());
524  CreateStackObject(Size, Alignment, true);
525  int Index = (int)Objects.size() - NumFixedObjects - 1;
526  ensureMaxAlignment(Alignment);
527  return Index;
528}
529
530/// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
531/// variable sized object has been created.  This must be created whenever a
532/// variable sized object is created, whether or not the index returned is
533/// actually used.
534///
535int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment,
536                                                const AllocaInst *Alloca) {
537  HasVarSizedObjects = true;
538  Alignment =
539    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
540                          !RealignOption,
541                        Alignment, getFrameLowering()->getStackAlignment());
542  Objects.push_back(StackObject(0, Alignment, 0, false, false, Alloca));
543  ensureMaxAlignment(Alignment);
544  return (int)Objects.size()-NumFixedObjects-1;
545}
546
547/// CreateFixedObject - Create a new object at a fixed location on the stack.
548/// All fixed objects should be created before other objects are created for
549/// efficiency. By default, fixed objects are immutable. This returns an
550/// index with a negative value.
551///
552int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
553                                        bool Immutable) {
554  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
555  // The alignment of the frame index can be determined from its offset from
556  // the incoming frame position.  If the frame object is at offset 32 and
557  // the stack is guaranteed to be 16-byte aligned, then we know that the
558  // object is 16-byte aligned.
559  unsigned StackAlign = getFrameLowering()->getStackAlignment();
560  unsigned Align = MinAlign(SPOffset, StackAlign);
561  Align =
562    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
563                          !RealignOption,
564                        Align, getFrameLowering()->getStackAlignment());
565  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
566                                              /*isSS*/   false,
567                                              /*Alloca*/ 0));
568  return -++NumFixedObjects;
569}
570
571
572BitVector
573MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
574  assert(MBB && "MBB must be valid");
575  const MachineFunction *MF = MBB->getParent();
576  assert(MF && "MBB must be part of a MachineFunction");
577  const TargetMachine &TM = MF->getTarget();
578  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
579  BitVector BV(TRI->getNumRegs());
580
581  // Before CSI is calculated, no registers are considered pristine. They can be
582  // freely used and PEI will make sure they are saved.
583  if (!isCalleeSavedInfoValid())
584    return BV;
585
586  for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
587    BV.set(*CSR);
588
589  // The entry MBB always has all CSRs pristine.
590  if (MBB == &MF->front())
591    return BV;
592
593  // On other MBBs the saved CSRs are not pristine.
594  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
595  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
596         E = CSI.end(); I != E; ++I)
597    BV.reset(I->getReg());
598
599  return BV;
600}
601
602unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
603  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
604  const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
605  unsigned MaxAlign = getMaxAlignment();
606  int Offset = 0;
607
608  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
609  // It really should be refactored to share code. Until then, changes
610  // should keep in mind that there's tight coupling between the two.
611
612  for (int i = getObjectIndexBegin(); i != 0; ++i) {
613    int FixedOff = -getObjectOffset(i);
614    if (FixedOff > Offset) Offset = FixedOff;
615  }
616  for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
617    if (isDeadObjectIndex(i))
618      continue;
619    Offset += getObjectSize(i);
620    unsigned Align = getObjectAlignment(i);
621    // Adjust to alignment boundary
622    Offset = (Offset+Align-1)/Align*Align;
623
624    MaxAlign = std::max(Align, MaxAlign);
625  }
626
627  if (adjustsStack() && TFI->hasReservedCallFrame(MF))
628    Offset += getMaxCallFrameSize();
629
630  // Round up the size to a multiple of the alignment.  If the function has
631  // any calls or alloca's, align to the target's StackAlignment value to
632  // ensure that the callee's frame or the alloca data is suitably aligned;
633  // otherwise, for leaf functions, align to the TransientStackAlignment
634  // value.
635  unsigned StackAlign;
636  if (adjustsStack() || hasVarSizedObjects() ||
637      (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
638    StackAlign = TFI->getStackAlignment();
639  else
640    StackAlign = TFI->getTransientStackAlignment();
641
642  // If the frame pointer is eliminated, all frame offsets will be relative to
643  // SP not FP. Align to MaxAlign so this works.
644  StackAlign = std::max(StackAlign, MaxAlign);
645  unsigned AlignMask = StackAlign - 1;
646  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
647
648  return (unsigned)Offset;
649}
650
651void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
652  if (Objects.empty()) return;
653
654  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
655  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
656
657  OS << "Frame Objects:\n";
658
659  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
660    const StackObject &SO = Objects[i];
661    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
662    if (SO.Size == ~0ULL) {
663      OS << "dead\n";
664      continue;
665    }
666    if (SO.Size == 0)
667      OS << "variable sized";
668    else
669      OS << "size=" << SO.Size;
670    OS << ", align=" << SO.Alignment;
671
672    if (i < NumFixedObjects)
673      OS << ", fixed";
674    if (i < NumFixedObjects || SO.SPOffset != -1) {
675      int64_t Off = SO.SPOffset - ValOffset;
676      OS << ", at location [SP";
677      if (Off > 0)
678        OS << "+" << Off;
679      else if (Off < 0)
680        OS << Off;
681      OS << "]";
682    }
683    OS << "\n";
684  }
685}
686
687#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
688void MachineFrameInfo::dump(const MachineFunction &MF) const {
689  print(MF, dbgs());
690}
691#endif
692
693//===----------------------------------------------------------------------===//
694//  MachineJumpTableInfo implementation
695//===----------------------------------------------------------------------===//
696
697/// getEntrySize - Return the size of each entry in the jump table.
698unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
699  // The size of a jump table entry is 4 bytes unless the entry is just the
700  // address of a block, in which case it is the pointer size.
701  switch (getEntryKind()) {
702  case MachineJumpTableInfo::EK_BlockAddress:
703    return TD.getPointerSize();
704  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
705    return 8;
706  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
707  case MachineJumpTableInfo::EK_LabelDifference32:
708  case MachineJumpTableInfo::EK_Custom32:
709    return 4;
710  case MachineJumpTableInfo::EK_Inline:
711    return 0;
712  }
713  llvm_unreachable("Unknown jump table encoding!");
714}
715
716/// getEntryAlignment - Return the alignment of each entry in the jump table.
717unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
718  // The alignment of a jump table entry is the alignment of int32 unless the
719  // entry is just the address of a block, in which case it is the pointer
720  // alignment.
721  switch (getEntryKind()) {
722  case MachineJumpTableInfo::EK_BlockAddress:
723    return TD.getPointerABIAlignment();
724  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
725    return TD.getABIIntegerTypeAlignment(64);
726  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
727  case MachineJumpTableInfo::EK_LabelDifference32:
728  case MachineJumpTableInfo::EK_Custom32:
729    return TD.getABIIntegerTypeAlignment(32);
730  case MachineJumpTableInfo::EK_Inline:
731    return 1;
732  }
733  llvm_unreachable("Unknown jump table encoding!");
734}
735
736/// createJumpTableIndex - Create a new jump table entry in the jump table info.
737///
738unsigned MachineJumpTableInfo::createJumpTableIndex(
739                               const std::vector<MachineBasicBlock*> &DestBBs) {
740  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
741  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
742  return JumpTables.size()-1;
743}
744
745/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
746/// the jump tables to branch to New instead.
747bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
748                                                  MachineBasicBlock *New) {
749  assert(Old != New && "Not making a change?");
750  bool MadeChange = false;
751  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
752    ReplaceMBBInJumpTable(i, Old, New);
753  return MadeChange;
754}
755
756/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
757/// the jump table to branch to New instead.
758bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
759                                                 MachineBasicBlock *Old,
760                                                 MachineBasicBlock *New) {
761  assert(Old != New && "Not making a change?");
762  bool MadeChange = false;
763  MachineJumpTableEntry &JTE = JumpTables[Idx];
764  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
765    if (JTE.MBBs[j] == Old) {
766      JTE.MBBs[j] = New;
767      MadeChange = true;
768    }
769  return MadeChange;
770}
771
772void MachineJumpTableInfo::print(raw_ostream &OS) const {
773  if (JumpTables.empty()) return;
774
775  OS << "Jump Tables:\n";
776
777  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
778    OS << "  jt#" << i << ": ";
779    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
780      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
781  }
782
783  OS << '\n';
784}
785
786#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
787void MachineJumpTableInfo::dump() const { print(dbgs()); }
788#endif
789
790
791//===----------------------------------------------------------------------===//
792//  MachineConstantPool implementation
793//===----------------------------------------------------------------------===//
794
795void MachineConstantPoolValue::anchor() { }
796
797const DataLayout *MachineConstantPool::getDataLayout() const {
798  return TM.getDataLayout();
799}
800
801Type *MachineConstantPoolEntry::getType() const {
802  if (isMachineConstantPoolEntry())
803    return Val.MachineCPVal->getType();
804  return Val.ConstVal->getType();
805}
806
807
808unsigned MachineConstantPoolEntry::getRelocationInfo() const {
809  if (isMachineConstantPoolEntry())
810    return Val.MachineCPVal->getRelocationInfo();
811  return Val.ConstVal->getRelocationInfo();
812}
813
814MachineConstantPool::~MachineConstantPool() {
815  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
816    if (Constants[i].isMachineConstantPoolEntry())
817      delete Constants[i].Val.MachineCPVal;
818  for (DenseSet<MachineConstantPoolValue*>::iterator I =
819       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
820       I != E; ++I)
821    delete *I;
822}
823
824/// CanShareConstantPoolEntry - Test whether the given two constants
825/// can be allocated the same constant pool entry.
826static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
827                                      const DataLayout *TD) {
828  // Handle the trivial case quickly.
829  if (A == B) return true;
830
831  // If they have the same type but weren't the same constant, quickly
832  // reject them.
833  if (A->getType() == B->getType()) return false;
834
835  // We can't handle structs or arrays.
836  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
837      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
838    return false;
839
840  // For now, only support constants with the same size.
841  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
842  if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
843      StoreSize > 128)
844    return false;
845
846  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
847
848  // Try constant folding a bitcast of both instructions to an integer.  If we
849  // get two identical ConstantInt's, then we are good to share them.  We use
850  // the constant folding APIs to do this so that we get the benefit of
851  // DataLayout.
852  if (isa<PointerType>(A->getType()))
853    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
854                                 const_cast<Constant*>(A), TD);
855  else if (A->getType() != IntTy)
856    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
857                                 const_cast<Constant*>(A), TD);
858  if (isa<PointerType>(B->getType()))
859    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
860                                 const_cast<Constant*>(B), TD);
861  else if (B->getType() != IntTy)
862    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
863                                 const_cast<Constant*>(B), TD);
864
865  return A == B;
866}
867
868/// getConstantPoolIndex - Create a new entry in the constant pool or return
869/// an existing one.  User must specify the log2 of the minimum required
870/// alignment for the object.
871///
872unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
873                                                   unsigned Alignment) {
874  assert(Alignment && "Alignment must be specified!");
875  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
876
877  // Check to see if we already have this constant.
878  //
879  // FIXME, this could be made much more efficient for large constant pools.
880  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
881    if (!Constants[i].isMachineConstantPoolEntry() &&
882        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
883                                  getDataLayout())) {
884      if ((unsigned)Constants[i].getAlignment() < Alignment)
885        Constants[i].Alignment = Alignment;
886      return i;
887    }
888
889  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
890  return Constants.size()-1;
891}
892
893unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
894                                                   unsigned Alignment) {
895  assert(Alignment && "Alignment must be specified!");
896  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
897
898  // Check to see if we already have this constant.
899  //
900  // FIXME, this could be made much more efficient for large constant pools.
901  int Idx = V->getExistingMachineCPValue(this, Alignment);
902  if (Idx != -1) {
903    MachineCPVsSharingEntries.insert(V);
904    return (unsigned)Idx;
905  }
906
907  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
908  return Constants.size()-1;
909}
910
911void MachineConstantPool::print(raw_ostream &OS) const {
912  if (Constants.empty()) return;
913
914  OS << "Constant Pool:\n";
915  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
916    OS << "  cp#" << i << ": ";
917    if (Constants[i].isMachineConstantPoolEntry())
918      Constants[i].Val.MachineCPVal->print(OS);
919    else
920      Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
921    OS << ", align=" << Constants[i].getAlignment();
922    OS << "\n";
923  }
924}
925
926#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
927void MachineConstantPool::dump() const { print(dbgs()); }
928#endif
929