MachineFunction.cpp revision 61fc8d670f1e991804c2ab753e567981e60962cb 
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/Assembly/Writer.h"
21#include "llvm/CodeGen/MachineConstantPool.h"
22#include "llvm/CodeGen/MachineFrameInfo.h"
23#include "llvm/CodeGen/MachineFunctionPass.h"
24#include "llvm/CodeGen/MachineInstr.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineModuleInfo.h"
27#include "llvm/CodeGen/MachineRegisterInfo.h"
28#include "llvm/CodeGen/Passes.h"
29#include "llvm/DebugInfo.h"
30#include "llvm/IR/DataLayout.h"
31#include "llvm/IR/Function.h"
32#include "llvm/MC/MCAsmInfo.h"
33#include "llvm/MC/MCContext.h"
34#include "llvm/Support/Debug.h"
35#include "llvm/Support/GraphWriter.h"
36#include "llvm/Support/raw_ostream.h"
37#include "llvm/Target/TargetFrameLowering.h"
38#include "llvm/Target/TargetLowering.h"
39#include "llvm/Target/TargetMachine.h"
40using namespace llvm;
41
42//===----------------------------------------------------------------------===//
43// MachineFunction implementation
44//===----------------------------------------------------------------------===//
45
46// Out of line virtual method.
47MachineFunctionInfo::~MachineFunctionInfo() {}
48
49void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
50  MBB->getParent()->DeleteMachineBasicBlock(MBB);
51}
52
53MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
54                                 unsigned FunctionNum, MachineModuleInfo &mmi,
55                                 GCModuleInfo* gmi)
56  : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
57  if (TM.getRegisterInfo())
58    RegInfo = new (Allocator) MachineRegisterInfo(TM);
59  else
60    RegInfo = 0;
61
62  MFInfo = 0;
63  FrameInfo =
64    new (Allocator) MachineFrameInfo(TM,!F->hasFnAttribute("no-realign-stack"));
65
66  if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
67                                       Attribute::StackAlignment))
68    FrameInfo->ensureMaxAlignment(Fn->getAttributes().
69                                getStackAlignment(AttributeSet::FunctionIndex));
70
71  ConstantPool = new (Allocator) MachineConstantPool(TM);
72  Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
73
74  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
75  if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
76                                        Attribute::OptimizeForSize))
77    Alignment = std::max(Alignment,
78                         TM.getTargetLowering()->getPrefFunctionAlignment());
79
80  FunctionNumber = FunctionNum;
81  JumpTableInfo = 0;
82}
83
84MachineFunction::~MachineFunction() {
85  // Don't call destructors on MachineInstr and MachineOperand. All of their
86  // memory comes from the BumpPtrAllocator which is about to be purged.
87  //
88  // Do call MachineBasicBlock destructors, it contains std::vectors.
89  for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
90    I->Insts.clearAndLeakNodesUnsafely();
91
92  InstructionRecycler.clear(Allocator);
93  OperandRecycler.clear(Allocator);
94  BasicBlockRecycler.clear(Allocator);
95  if (RegInfo) {
96    RegInfo->~MachineRegisterInfo();
97    Allocator.Deallocate(RegInfo);
98  }
99  if (MFInfo) {
100    MFInfo->~MachineFunctionInfo();
101    Allocator.Deallocate(MFInfo);
102  }
103
104  FrameInfo->~MachineFrameInfo();
105  Allocator.Deallocate(FrameInfo);
106
107  ConstantPool->~MachineConstantPool();
108  Allocator.Deallocate(ConstantPool);
109
110  if (JumpTableInfo) {
111    JumpTableInfo->~MachineJumpTableInfo();
112    Allocator.Deallocate(JumpTableInfo);
113  }
114}
115
116/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
117/// does already exist, allocate one.
118MachineJumpTableInfo *MachineFunction::
119getOrCreateJumpTableInfo(unsigned EntryKind) {
120  if (JumpTableInfo) return JumpTableInfo;
121
122  JumpTableInfo = new (Allocator)
123    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
124  return JumpTableInfo;
125}
126
127/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
128/// recomputes them.  This guarantees that the MBB numbers are sequential,
129/// dense, and match the ordering of the blocks within the function.  If a
130/// specific MachineBasicBlock is specified, only that block and those after
131/// it are renumbered.
132void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
133  if (empty()) { MBBNumbering.clear(); return; }
134  MachineFunction::iterator MBBI, E = end();
135  if (MBB == 0)
136    MBBI = begin();
137  else
138    MBBI = MBB;
139
140  // Figure out the block number this should have.
141  unsigned BlockNo = 0;
142  if (MBBI != begin())
143    BlockNo = prior(MBBI)->getNumber()+1;
144
145  for (; MBBI != E; ++MBBI, ++BlockNo) {
146    if (MBBI->getNumber() != (int)BlockNo) {
147      // Remove use of the old number.
148      if (MBBI->getNumber() != -1) {
149        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
150               "MBB number mismatch!");
151        MBBNumbering[MBBI->getNumber()] = 0;
152      }
153
154      // If BlockNo is already taken, set that block's number to -1.
155      if (MBBNumbering[BlockNo])
156        MBBNumbering[BlockNo]->setNumber(-1);
157
158      MBBNumbering[BlockNo] = MBBI;
159      MBBI->setNumber(BlockNo);
160    }
161  }
162
163  // Okay, all the blocks are renumbered.  If we have compactified the block
164  // numbering, shrink MBBNumbering now.
165  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
166  MBBNumbering.resize(BlockNo);
167}
168
169/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
170/// of `new MachineInstr'.
171///
172MachineInstr *
173MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
174                                    DebugLoc DL, bool NoImp) {
175  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
176    MachineInstr(*this, MCID, DL, NoImp);
177}
178
179/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
180/// 'Orig' instruction, identical in all ways except the instruction
181/// has no parent, prev, or next.
182///
183MachineInstr *
184MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
185  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
186             MachineInstr(*this, *Orig);
187}
188
189/// DeleteMachineInstr - Delete the given MachineInstr.
190///
191/// This function also serves as the MachineInstr destructor - the real
192/// ~MachineInstr() destructor must be empty.
193void
194MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
195  // Strip it for parts. The operand array and the MI object itself are
196  // independently recyclable.
197  if (MI->Operands)
198    deallocateOperandArray(MI->CapOperands, MI->Operands);
199  // Don't call ~MachineInstr() which must be trivial anyway because
200  // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
201  // destructors.
202  InstructionRecycler.Deallocate(Allocator, MI);
203}
204
205/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
206/// instead of `new MachineBasicBlock'.
207///
208MachineBasicBlock *
209MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
210  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
211             MachineBasicBlock(*this, bb);
212}
213
214/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
215///
216void
217MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
218  assert(MBB->getParent() == this && "MBB parent mismatch!");
219  MBB->~MachineBasicBlock();
220  BasicBlockRecycler.Deallocate(Allocator, MBB);
221}
222
223MachineMemOperand *
224MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
225                                      uint64_t s, unsigned base_alignment,
226                                      const MDNode *TBAAInfo,
227                                      const MDNode *Ranges) {
228  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
229                                           TBAAInfo, Ranges);
230}
231
232MachineMemOperand *
233MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
234                                      int64_t Offset, uint64_t Size) {
235  return new (Allocator)
236             MachineMemOperand(MachinePointerInfo(MMO->getValue(),
237                                                  MMO->getOffset()+Offset),
238                               MMO->getFlags(), Size,
239                               MMO->getBaseAlignment(), 0);
240}
241
242MachineInstr::mmo_iterator
243MachineFunction::allocateMemRefsArray(unsigned long Num) {
244  return Allocator.Allocate<MachineMemOperand *>(Num);
245}
246
247std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
248MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
249                                    MachineInstr::mmo_iterator End) {
250  // Count the number of load mem refs.
251  unsigned Num = 0;
252  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
253    if ((*I)->isLoad())
254      ++Num;
255
256  // Allocate a new array and populate it with the load information.
257  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
258  unsigned Index = 0;
259  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
260    if ((*I)->isLoad()) {
261      if (!(*I)->isStore())
262        // Reuse the MMO.
263        Result[Index] = *I;
264      else {
265        // Clone the MMO and unset the store flag.
266        MachineMemOperand *JustLoad =
267          getMachineMemOperand((*I)->getPointerInfo(),
268                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
269                               (*I)->getSize(), (*I)->getBaseAlignment(),
270                               (*I)->getTBAAInfo());
271        Result[Index] = JustLoad;
272      }
273      ++Index;
274    }
275  }
276  return std::make_pair(Result, Result + Num);
277}
278
279std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
280MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
281                                     MachineInstr::mmo_iterator End) {
282  // Count the number of load mem refs.
283  unsigned Num = 0;
284  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
285    if ((*I)->isStore())
286      ++Num;
287
288  // Allocate a new array and populate it with the store information.
289  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
290  unsigned Index = 0;
291  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
292    if ((*I)->isStore()) {
293      if (!(*I)->isLoad())
294        // Reuse the MMO.
295        Result[Index] = *I;
296      else {
297        // Clone the MMO and unset the load flag.
298        MachineMemOperand *JustStore =
299          getMachineMemOperand((*I)->getPointerInfo(),
300                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
301                               (*I)->getSize(), (*I)->getBaseAlignment(),
302                               (*I)->getTBAAInfo());
303        Result[Index] = JustStore;
304      }
305      ++Index;
306    }
307  }
308  return std::make_pair(Result, Result + Num);
309}
310
311#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
312void MachineFunction::dump() const {
313  print(dbgs());
314}
315#endif
316
317StringRef MachineFunction::getName() const {
318  assert(getFunction() && "No function!");
319  return getFunction()->getName();
320}
321
322void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
323  OS << "# Machine code for function " << getName() << ": ";
324  if (RegInfo) {
325    OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
326    if (!RegInfo->tracksLiveness())
327      OS << ", not tracking liveness";
328  }
329  OS << '\n';
330
331  // Print Frame Information
332  FrameInfo->print(*this, OS);
333
334  // Print JumpTable Information
335  if (JumpTableInfo)
336    JumpTableInfo->print(OS);
337
338  // Print Constant Pool
339  ConstantPool->print(OS);
340
341  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
342
343  if (RegInfo && !RegInfo->livein_empty()) {
344    OS << "Function Live Ins: ";
345    for (MachineRegisterInfo::livein_iterator
346         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
347      OS << PrintReg(I->first, TRI);
348      if (I->second)
349        OS << " in " << PrintReg(I->second, TRI);
350      if (llvm::next(I) != E)
351        OS << ", ";
352    }
353    OS << '\n';
354  }
355
356  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
357    OS << '\n';
358    BB->print(OS, Indexes);
359  }
360
361  OS << "\n# End machine code for function " << getName() << ".\n\n";
362}
363
364namespace llvm {
365  template<>
366  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
367
368  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
369
370    static std::string getGraphName(const MachineFunction *F) {
371      return "CFG for '" + F->getName().str() + "' function";
372    }
373
374    std::string getNodeLabel(const MachineBasicBlock *Node,
375                             const MachineFunction *Graph) {
376      std::string OutStr;
377      {
378        raw_string_ostream OSS(OutStr);
379
380        if (isSimple()) {
381          OSS << "BB#" << Node->getNumber();
382          if (const BasicBlock *BB = Node->getBasicBlock())
383            OSS << ": " << BB->getName();
384        } else
385          Node->print(OSS);
386      }
387
388      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
389
390      // Process string output to make it nicer...
391      for (unsigned i = 0; i != OutStr.length(); ++i)
392        if (OutStr[i] == '\n') {                            // Left justify
393          OutStr[i] = '\\';
394          OutStr.insert(OutStr.begin()+i+1, 'l');
395        }
396      return OutStr;
397    }
398  };
399}
400
401void MachineFunction::viewCFG() const
402{
403#ifndef NDEBUG
404  ViewGraph(this, "mf" + getName());
405#else
406  errs() << "MachineFunction::viewCFG is only available in debug builds on "
407         << "systems with Graphviz or gv!\n";
408#endif // NDEBUG
409}
410
411void MachineFunction::viewCFGOnly() const
412{
413#ifndef NDEBUG
414  ViewGraph(this, "mf" + getName(), true);
415#else
416  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
417         << "systems with Graphviz or gv!\n";
418#endif // NDEBUG
419}
420
421/// addLiveIn - Add the specified physical register as a live-in value and
422/// create a corresponding virtual register for it.
423unsigned MachineFunction::addLiveIn(unsigned PReg,
424                                    const TargetRegisterClass *RC) {
425  MachineRegisterInfo &MRI = getRegInfo();
426  unsigned VReg = MRI.getLiveInVirtReg(PReg);
427  if (VReg) {
428    assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
429    return VReg;
430  }
431  VReg = MRI.createVirtualRegister(RC);
432  MRI.addLiveIn(PReg, VReg);
433  return VReg;
434}
435
436/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
437/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
438/// normal 'L' label is returned.
439MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
440                                        bool isLinkerPrivate) const {
441  assert(JumpTableInfo && "No jump tables");
442  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
443  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
444
445  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
446                                         MAI.getPrivateGlobalPrefix();
447  SmallString<60> Name;
448  raw_svector_ostream(Name)
449    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
450  return Ctx.GetOrCreateSymbol(Name.str());
451}
452
453/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
454/// base.
455MCSymbol *MachineFunction::getPICBaseSymbol() const {
456  const MCAsmInfo &MAI = *Target.getMCAsmInfo();
457  return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
458                               Twine(getFunctionNumber())+"$pb");
459}
460
461//===----------------------------------------------------------------------===//
462//  MachineFrameInfo implementation
463//===----------------------------------------------------------------------===//
464
465const TargetFrameLowering *MachineFrameInfo::getFrameLowering() const {
466  return TM.getFrameLowering();
467}
468
469/// ensureMaxAlignment - Make sure the function is at least Align bytes
470/// aligned.
471void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
472  if (!getFrameLowering()->isStackRealignable() || !RealignOption)
473    assert(Align <= getFrameLowering()->getStackAlignment() &&
474           "For targets without stack realignment, Align is out of limit!");
475  if (MaxAlignment < Align) MaxAlignment = Align;
476}
477
478/// clampStackAlignment - Clamp the alignment if requested and emit a warning.
479static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
480                                           unsigned StackAlign) {
481  if (!ShouldClamp || Align <= StackAlign)
482    return Align;
483  DEBUG(dbgs() << "Warning: requested alignment " << Align
484               << " exceeds the stack alignment " << StackAlign
485               << " when stack realignment is off" << '\n');
486  return StackAlign;
487}
488
489/// CreateStackObject - Create a new statically sized stack object, returning
490/// a nonnegative identifier to represent it.
491///
492int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
493                      bool isSS, bool MayNeedSP, const AllocaInst *Alloca) {
494  assert(Size != 0 && "Cannot allocate zero size stack objects!");
495  Alignment =
496    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
497                          !RealignOption,
498                        Alignment, getFrameLowering()->getStackAlignment());
499  Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, MayNeedSP,
500                                Alloca));
501  int Index = (int)Objects.size() - NumFixedObjects - 1;
502  assert(Index >= 0 && "Bad frame index!");
503  ensureMaxAlignment(Alignment);
504  return Index;
505}
506
507/// CreateSpillStackObject - Create a new statically sized stack object that
508/// represents a spill slot, returning a nonnegative identifier to represent
509/// it.
510///
511int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
512                                             unsigned Alignment) {
513  Alignment =
514    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
515                          !RealignOption,
516                        Alignment, getFrameLowering()->getStackAlignment());
517  CreateStackObject(Size, Alignment, true, false);
518  int Index = (int)Objects.size() - NumFixedObjects - 1;
519  ensureMaxAlignment(Alignment);
520  return Index;
521}
522
523/// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
524/// variable sized object has been created.  This must be created whenever a
525/// variable sized object is created, whether or not the index returned is
526/// actually used.
527///
528int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment) {
529  HasVarSizedObjects = true;
530  Alignment =
531    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
532                          !RealignOption,
533                        Alignment, getFrameLowering()->getStackAlignment());
534  Objects.push_back(StackObject(0, Alignment, 0, false, false, true, 0));
535  ensureMaxAlignment(Alignment);
536  return (int)Objects.size()-NumFixedObjects-1;
537}
538
539/// CreateFixedObject - Create a new object at a fixed location on the stack.
540/// All fixed objects should be created before other objects are created for
541/// efficiency. By default, fixed objects are immutable. This returns an
542/// index with a negative value.
543///
544int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
545                                        bool Immutable) {
546  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
547  // The alignment of the frame index can be determined from its offset from
548  // the incoming frame position.  If the frame object is at offset 32 and
549  // the stack is guaranteed to be 16-byte aligned, then we know that the
550  // object is 16-byte aligned.
551  unsigned StackAlign = getFrameLowering()->getStackAlignment();
552  unsigned Align = MinAlign(SPOffset, StackAlign);
553  Align =
554    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
555                          !RealignOption,
556                        Align, getFrameLowering()->getStackAlignment());
557  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
558                                              /*isSS*/   false,
559                                              /*NeedSP*/ false,
560                                              /*Alloca*/ 0));
561  return -++NumFixedObjects;
562}
563
564
565BitVector
566MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
567  assert(MBB && "MBB must be valid");
568  const MachineFunction *MF = MBB->getParent();
569  assert(MF && "MBB must be part of a MachineFunction");
570  const TargetMachine &TM = MF->getTarget();
571  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
572  BitVector BV(TRI->getNumRegs());
573
574  // Before CSI is calculated, no registers are considered pristine. They can be
575  // freely used and PEI will make sure they are saved.
576  if (!isCalleeSavedInfoValid())
577    return BV;
578
579  for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
580    BV.set(*CSR);
581
582  // The entry MBB always has all CSRs pristine.
583  if (MBB == &MF->front())
584    return BV;
585
586  // On other MBBs the saved CSRs are not pristine.
587  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
588  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
589         E = CSI.end(); I != E; ++I)
590    BV.reset(I->getReg());
591
592  return BV;
593}
594
595unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
596  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
597  const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
598  unsigned MaxAlign = getMaxAlignment();
599  int Offset = 0;
600
601  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
602  // It really should be refactored to share code. Until then, changes
603  // should keep in mind that there's tight coupling between the two.
604
605  for (int i = getObjectIndexBegin(); i != 0; ++i) {
606    int FixedOff = -getObjectOffset(i);
607    if (FixedOff > Offset) Offset = FixedOff;
608  }
609  for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
610    if (isDeadObjectIndex(i))
611      continue;
612    Offset += getObjectSize(i);
613    unsigned Align = getObjectAlignment(i);
614    // Adjust to alignment boundary
615    Offset = (Offset+Align-1)/Align*Align;
616
617    MaxAlign = std::max(Align, MaxAlign);
618  }
619
620  if (adjustsStack() && TFI->hasReservedCallFrame(MF))
621    Offset += getMaxCallFrameSize();
622
623  // Round up the size to a multiple of the alignment.  If the function has
624  // any calls or alloca's, align to the target's StackAlignment value to
625  // ensure that the callee's frame or the alloca data is suitably aligned;
626  // otherwise, for leaf functions, align to the TransientStackAlignment
627  // value.
628  unsigned StackAlign;
629  if (adjustsStack() || hasVarSizedObjects() ||
630      (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
631    StackAlign = TFI->getStackAlignment();
632  else
633    StackAlign = TFI->getTransientStackAlignment();
634
635  // If the frame pointer is eliminated, all frame offsets will be relative to
636  // SP not FP. Align to MaxAlign so this works.
637  StackAlign = std::max(StackAlign, MaxAlign);
638  unsigned AlignMask = StackAlign - 1;
639  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
640
641  return (unsigned)Offset;
642}
643
644void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
645  if (Objects.empty()) return;
646
647  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
648  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
649
650  OS << "Frame Objects:\n";
651
652  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
653    const StackObject &SO = Objects[i];
654    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
655    if (SO.Size == ~0ULL) {
656      OS << "dead\n";
657      continue;
658    }
659    if (SO.Size == 0)
660      OS << "variable sized";
661    else
662      OS << "size=" << SO.Size;
663    OS << ", align=" << SO.Alignment;
664
665    if (i < NumFixedObjects)
666      OS << ", fixed";
667    if (i < NumFixedObjects || SO.SPOffset != -1) {
668      int64_t Off = SO.SPOffset - ValOffset;
669      OS << ", at location [SP";
670      if (Off > 0)
671        OS << "+" << Off;
672      else if (Off < 0)
673        OS << Off;
674      OS << "]";
675    }
676    OS << "\n";
677  }
678}
679
680#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
681void MachineFrameInfo::dump(const MachineFunction &MF) const {
682  print(MF, dbgs());
683}
684#endif
685
686//===----------------------------------------------------------------------===//
687//  MachineJumpTableInfo implementation
688//===----------------------------------------------------------------------===//
689
690/// getEntrySize - Return the size of each entry in the jump table.
691unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
692  // The size of a jump table entry is 4 bytes unless the entry is just the
693  // address of a block, in which case it is the pointer size.
694  switch (getEntryKind()) {
695  case MachineJumpTableInfo::EK_BlockAddress:
696    return TD.getPointerSize();
697  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
698    return 8;
699  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
700  case MachineJumpTableInfo::EK_LabelDifference32:
701  case MachineJumpTableInfo::EK_Custom32:
702    return 4;
703  case MachineJumpTableInfo::EK_Inline:
704    return 0;
705  }
706  llvm_unreachable("Unknown jump table encoding!");
707}
708
709/// getEntryAlignment - Return the alignment of each entry in the jump table.
710unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
711  // The alignment of a jump table entry is the alignment of int32 unless the
712  // entry is just the address of a block, in which case it is the pointer
713  // alignment.
714  switch (getEntryKind()) {
715  case MachineJumpTableInfo::EK_BlockAddress:
716    return TD.getPointerABIAlignment();
717  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
718    return TD.getABIIntegerTypeAlignment(64);
719  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
720  case MachineJumpTableInfo::EK_LabelDifference32:
721  case MachineJumpTableInfo::EK_Custom32:
722    return TD.getABIIntegerTypeAlignment(32);
723  case MachineJumpTableInfo::EK_Inline:
724    return 1;
725  }
726  llvm_unreachable("Unknown jump table encoding!");
727}
728
729/// createJumpTableIndex - Create a new jump table entry in the jump table info.
730///
731unsigned MachineJumpTableInfo::createJumpTableIndex(
732                               const std::vector<MachineBasicBlock*> &DestBBs) {
733  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
734  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
735  return JumpTables.size()-1;
736}
737
738/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
739/// the jump tables to branch to New instead.
740bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
741                                                  MachineBasicBlock *New) {
742  assert(Old != New && "Not making a change?");
743  bool MadeChange = false;
744  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
745    ReplaceMBBInJumpTable(i, Old, New);
746  return MadeChange;
747}
748
749/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
750/// the jump table to branch to New instead.
751bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
752                                                 MachineBasicBlock *Old,
753                                                 MachineBasicBlock *New) {
754  assert(Old != New && "Not making a change?");
755  bool MadeChange = false;
756  MachineJumpTableEntry &JTE = JumpTables[Idx];
757  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
758    if (JTE.MBBs[j] == Old) {
759      JTE.MBBs[j] = New;
760      MadeChange = true;
761    }
762  return MadeChange;
763}
764
765void MachineJumpTableInfo::print(raw_ostream &OS) const {
766  if (JumpTables.empty()) return;
767
768  OS << "Jump Tables:\n";
769
770  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
771    OS << "  jt#" << i << ": ";
772    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
773      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
774  }
775
776  OS << '\n';
777}
778
779#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
780void MachineJumpTableInfo::dump() const { print(dbgs()); }
781#endif
782
783
784//===----------------------------------------------------------------------===//
785//  MachineConstantPool implementation
786//===----------------------------------------------------------------------===//
787
788void MachineConstantPoolValue::anchor() { }
789
790const DataLayout *MachineConstantPool::getDataLayout() const {
791  return TM.getDataLayout();
792}
793
794Type *MachineConstantPoolEntry::getType() const {
795  if (isMachineConstantPoolEntry())
796    return Val.MachineCPVal->getType();
797  return Val.ConstVal->getType();
798}
799
800
801unsigned MachineConstantPoolEntry::getRelocationInfo() const {
802  if (isMachineConstantPoolEntry())
803    return Val.MachineCPVal->getRelocationInfo();
804  return Val.ConstVal->getRelocationInfo();
805}
806
807MachineConstantPool::~MachineConstantPool() {
808  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
809    if (Constants[i].isMachineConstantPoolEntry())
810      delete Constants[i].Val.MachineCPVal;
811  for (DenseSet<MachineConstantPoolValue*>::iterator I =
812       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
813       I != E; ++I)
814    delete *I;
815}
816
817/// CanShareConstantPoolEntry - Test whether the given two constants
818/// can be allocated the same constant pool entry.
819static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
820                                      const DataLayout *TD) {
821  // Handle the trivial case quickly.
822  if (A == B) return true;
823
824  // If they have the same type but weren't the same constant, quickly
825  // reject them.
826  if (A->getType() == B->getType()) return false;
827
828  // We can't handle structs or arrays.
829  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
830      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
831    return false;
832
833  // For now, only support constants with the same size.
834  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
835  if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
836      StoreSize > 128)
837    return false;
838
839  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
840
841  // Try constant folding a bitcast of both instructions to an integer.  If we
842  // get two identical ConstantInt's, then we are good to share them.  We use
843  // the constant folding APIs to do this so that we get the benefit of
844  // DataLayout.
845  if (isa<PointerType>(A->getType()))
846    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
847                                 const_cast<Constant*>(A), TD);
848  else if (A->getType() != IntTy)
849    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
850                                 const_cast<Constant*>(A), TD);
851  if (isa<PointerType>(B->getType()))
852    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
853                                 const_cast<Constant*>(B), TD);
854  else if (B->getType() != IntTy)
855    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
856                                 const_cast<Constant*>(B), TD);
857
858  return A == B;
859}
860
861/// getConstantPoolIndex - Create a new entry in the constant pool or return
862/// an existing one.  User must specify the log2 of the minimum required
863/// alignment for the object.
864///
865unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
866                                                   unsigned Alignment) {
867  assert(Alignment && "Alignment must be specified!");
868  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
869
870  // Check to see if we already have this constant.
871  //
872  // FIXME, this could be made much more efficient for large constant pools.
873  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
874    if (!Constants[i].isMachineConstantPoolEntry() &&
875        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
876                                  getDataLayout())) {
877      if ((unsigned)Constants[i].getAlignment() < Alignment)
878        Constants[i].Alignment = Alignment;
879      return i;
880    }
881
882  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
883  return Constants.size()-1;
884}
885
886unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
887                                                   unsigned Alignment) {
888  assert(Alignment && "Alignment must be specified!");
889  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
890
891  // Check to see if we already have this constant.
892  //
893  // FIXME, this could be made much more efficient for large constant pools.
894  int Idx = V->getExistingMachineCPValue(this, Alignment);
895  if (Idx != -1) {
896    MachineCPVsSharingEntries.insert(V);
897    return (unsigned)Idx;
898  }
899
900  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
901  return Constants.size()-1;
902}
903
904void MachineConstantPool::print(raw_ostream &OS) const {
905  if (Constants.empty()) return;
906
907  OS << "Constant Pool:\n";
908  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
909    OS << "  cp#" << i << ": ";
910    if (Constants[i].isMachineConstantPoolEntry())
911      Constants[i].Val.MachineCPVal->print(OS);
912    else
913      WriteAsOperand(OS, Constants[i].Val.ConstVal, /*PrintType=*/false);
914    OS << ", align=" << Constants[i].getAlignment();
915    OS << "\n";
916  }
917}
918
919#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
920void MachineConstantPool::dump() const { print(dbgs()); }
921#endif
922