MachineFunction.cpp revision 259065 
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/DebugInfo.h"
29#include "llvm/IR/DataLayout.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.getRegisterInfo());
58  else
59    RegInfo = 0;
60  MFInfo = 0;
61  FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering(),
62                                               TM.Options.RealignStack);
63  if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
64                                       Attribute::StackAlignment))
65    FrameInfo->ensureMaxAlignment(Fn->getAttributes().
66                                getStackAlignment(AttributeSet::FunctionIndex));
67  ConstantPool = new (Allocator) MachineConstantPool(TM.getDataLayout());
68  Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
69  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
70  if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
71                                        Attribute::OptimizeForSize))
72    Alignment = std::max(Alignment,
73                         TM.getTargetLowering()->getPrefFunctionAlignment());
74  FunctionNumber = FunctionNum;
75  JumpTableInfo = 0;
76}
77
78MachineFunction::~MachineFunction() {
79  // Don't call destructors on MachineInstr and MachineOperand. All of their
80  // memory comes from the BumpPtrAllocator which is about to be purged.
81  //
82  // Do call MachineBasicBlock destructors, it contains std::vectors.
83  for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
84    I->Insts.clearAndLeakNodesUnsafely();
85
86  InstructionRecycler.clear(Allocator);
87  OperandRecycler.clear(Allocator);
88  BasicBlockRecycler.clear(Allocator);
89  if (RegInfo) {
90    RegInfo->~MachineRegisterInfo();
91    Allocator.Deallocate(RegInfo);
92  }
93  if (MFInfo) {
94    MFInfo->~MachineFunctionInfo();
95    Allocator.Deallocate(MFInfo);
96  }
97
98  FrameInfo->~MachineFrameInfo();
99  Allocator.Deallocate(FrameInfo);
100
101  ConstantPool->~MachineConstantPool();
102  Allocator.Deallocate(ConstantPool);
103
104  if (JumpTableInfo) {
105    JumpTableInfo->~MachineJumpTableInfo();
106    Allocator.Deallocate(JumpTableInfo);
107  }
108}
109
110/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
111/// does already exist, allocate one.
112MachineJumpTableInfo *MachineFunction::
113getOrCreateJumpTableInfo(unsigned EntryKind) {
114  if (JumpTableInfo) return JumpTableInfo;
115
116  JumpTableInfo = new (Allocator)
117    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
118  return JumpTableInfo;
119}
120
121/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
122/// recomputes them.  This guarantees that the MBB numbers are sequential,
123/// dense, and match the ordering of the blocks within the function.  If a
124/// specific MachineBasicBlock is specified, only that block and those after
125/// it are renumbered.
126void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
127  if (empty()) { MBBNumbering.clear(); return; }
128  MachineFunction::iterator MBBI, E = end();
129  if (MBB == 0)
130    MBBI = begin();
131  else
132    MBBI = MBB;
133
134  // Figure out the block number this should have.
135  unsigned BlockNo = 0;
136  if (MBBI != begin())
137    BlockNo = prior(MBBI)->getNumber()+1;
138
139  for (; MBBI != E; ++MBBI, ++BlockNo) {
140    if (MBBI->getNumber() != (int)BlockNo) {
141      // Remove use of the old number.
142      if (MBBI->getNumber() != -1) {
143        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
144               "MBB number mismatch!");
145        MBBNumbering[MBBI->getNumber()] = 0;
146      }
147
148      // If BlockNo is already taken, set that block's number to -1.
149      if (MBBNumbering[BlockNo])
150        MBBNumbering[BlockNo]->setNumber(-1);
151
152      MBBNumbering[BlockNo] = MBBI;
153      MBBI->setNumber(BlockNo);
154    }
155  }
156
157  // Okay, all the blocks are renumbered.  If we have compactified the block
158  // numbering, shrink MBBNumbering now.
159  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
160  MBBNumbering.resize(BlockNo);
161}
162
163/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
164/// of `new MachineInstr'.
165///
166MachineInstr *
167MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
168                                    DebugLoc DL, bool NoImp) {
169  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
170    MachineInstr(*this, MCID, DL, NoImp);
171}
172
173/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
174/// 'Orig' instruction, identical in all ways except the instruction
175/// has no parent, prev, or next.
176///
177MachineInstr *
178MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
179  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
180             MachineInstr(*this, *Orig);
181}
182
183/// DeleteMachineInstr - Delete the given MachineInstr.
184///
185/// This function also serves as the MachineInstr destructor - the real
186/// ~MachineInstr() destructor must be empty.
187void
188MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
189  // Strip it for parts. The operand array and the MI object itself are
190  // independently recyclable.
191  if (MI->Operands)
192    deallocateOperandArray(MI->CapOperands, MI->Operands);
193  // Don't call ~MachineInstr() which must be trivial anyway because
194  // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
195  // destructors.
196  InstructionRecycler.Deallocate(Allocator, MI);
197}
198
199/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
200/// instead of `new MachineBasicBlock'.
201///
202MachineBasicBlock *
203MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
204  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
205             MachineBasicBlock(*this, bb);
206}
207
208/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
209///
210void
211MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
212  assert(MBB->getParent() == this && "MBB parent mismatch!");
213  MBB->~MachineBasicBlock();
214  BasicBlockRecycler.Deallocate(Allocator, MBB);
215}
216
217MachineMemOperand *
218MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
219                                      uint64_t s, unsigned base_alignment,
220                                      const MDNode *TBAAInfo,
221                                      const MDNode *Ranges) {
222  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
223                                           TBAAInfo, Ranges);
224}
225
226MachineMemOperand *
227MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
228                                      int64_t Offset, uint64_t Size) {
229  return new (Allocator)
230             MachineMemOperand(MachinePointerInfo(MMO->getValue(),
231                                                  MMO->getOffset()+Offset),
232                               MMO->getFlags(), Size,
233                               MMO->getBaseAlignment(), 0);
234}
235
236MachineInstr::mmo_iterator
237MachineFunction::allocateMemRefsArray(unsigned long Num) {
238  return Allocator.Allocate<MachineMemOperand *>(Num);
239}
240
241std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
242MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
243                                    MachineInstr::mmo_iterator End) {
244  // Count the number of load mem refs.
245  unsigned Num = 0;
246  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
247    if ((*I)->isLoad())
248      ++Num;
249
250  // Allocate a new array and populate it with the load information.
251  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
252  unsigned Index = 0;
253  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
254    if ((*I)->isLoad()) {
255      if (!(*I)->isStore())
256        // Reuse the MMO.
257        Result[Index] = *I;
258      else {
259        // Clone the MMO and unset the store flag.
260        MachineMemOperand *JustLoad =
261          getMachineMemOperand((*I)->getPointerInfo(),
262                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
263                               (*I)->getSize(), (*I)->getBaseAlignment(),
264                               (*I)->getTBAAInfo());
265        Result[Index] = JustLoad;
266      }
267      ++Index;
268    }
269  }
270  return std::make_pair(Result, Result + Num);
271}
272
273std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
274MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
275                                     MachineInstr::mmo_iterator End) {
276  // Count the number of load mem refs.
277  unsigned Num = 0;
278  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
279    if ((*I)->isStore())
280      ++Num;
281
282  // Allocate a new array and populate it with the store information.
283  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
284  unsigned Index = 0;
285  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
286    if ((*I)->isStore()) {
287      if (!(*I)->isLoad())
288        // Reuse the MMO.
289        Result[Index] = *I;
290      else {
291        // Clone the MMO and unset the load flag.
292        MachineMemOperand *JustStore =
293          getMachineMemOperand((*I)->getPointerInfo(),
294                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
295                               (*I)->getSize(), (*I)->getBaseAlignment(),
296                               (*I)->getTBAAInfo());
297        Result[Index] = JustStore;
298      }
299      ++Index;
300    }
301  }
302  return std::make_pair(Result, Result + Num);
303}
304
305#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
306void MachineFunction::dump() const {
307  print(dbgs());
308}
309#endif
310
311StringRef MachineFunction::getName() const {
312  assert(getFunction() && "No function!");
313  return getFunction()->getName();
314}
315
316void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
317  OS << "# Machine code for function " << getName() << ": ";
318  if (RegInfo) {
319    OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
320    if (!RegInfo->tracksLiveness())
321      OS << ", not tracking liveness";
322  }
323  OS << '\n';
324
325  // Print Frame Information
326  FrameInfo->print(*this, OS);
327
328  // Print JumpTable Information
329  if (JumpTableInfo)
330    JumpTableInfo->print(OS);
331
332  // Print Constant Pool
333  ConstantPool->print(OS);
334
335  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
336
337  if (RegInfo && !RegInfo->livein_empty()) {
338    OS << "Function Live Ins: ";
339    for (MachineRegisterInfo::livein_iterator
340         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
341      OS << PrintReg(I->first, TRI);
342      if (I->second)
343        OS << " in " << PrintReg(I->second, TRI);
344      if (llvm::next(I) != E)
345        OS << ", ";
346    }
347    OS << '\n';
348  }
349
350  for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
351    OS << '\n';
352    BB->print(OS, Indexes);
353  }
354
355  OS << "\n# End machine code for function " << getName() << ".\n\n";
356}
357
358namespace llvm {
359  template<>
360  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
361
362  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
363
364    static std::string getGraphName(const MachineFunction *F) {
365      return "CFG for '" + F->getName().str() + "' function";
366    }
367
368    std::string getNodeLabel(const MachineBasicBlock *Node,
369                             const MachineFunction *Graph) {
370      std::string OutStr;
371      {
372        raw_string_ostream OSS(OutStr);
373
374        if (isSimple()) {
375          OSS << "BB#" << Node->getNumber();
376          if (const BasicBlock *BB = Node->getBasicBlock())
377            OSS << ": " << BB->getName();
378        } else
379          Node->print(OSS);
380      }
381
382      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
383
384      // Process string output to make it nicer...
385      for (unsigned i = 0; i != OutStr.length(); ++i)
386        if (OutStr[i] == '\n') {                            // Left justify
387          OutStr[i] = '\\';
388          OutStr.insert(OutStr.begin()+i+1, 'l');
389        }
390      return OutStr;
391    }
392  };
393}
394
395void MachineFunction::viewCFG() const
396{
397#ifndef NDEBUG
398  ViewGraph(this, "mf" + getName());
399#else
400  errs() << "MachineFunction::viewCFG is only available in debug builds on "
401         << "systems with Graphviz or gv!\n";
402#endif // NDEBUG
403}
404
405void MachineFunction::viewCFGOnly() const
406{
407#ifndef NDEBUG
408  ViewGraph(this, "mf" + getName(), true);
409#else
410  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
411         << "systems with Graphviz or gv!\n";
412#endif // NDEBUG
413}
414
415/// addLiveIn - Add the specified physical register as a live-in value and
416/// create a corresponding virtual register for it.
417unsigned MachineFunction::addLiveIn(unsigned PReg,
418                                    const TargetRegisterClass *RC) {
419  MachineRegisterInfo &MRI = getRegInfo();
420  unsigned VReg = MRI.getLiveInVirtReg(PReg);
421  if (VReg) {
422    assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
423    return VReg;
424  }
425  VReg = MRI.createVirtualRegister(RC);
426  MRI.addLiveIn(PReg, VReg);
427  return VReg;
428}
429
430/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
431/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
432/// normal 'L' label is returned.
433MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
434                                        bool isLinkerPrivate) const {
435  assert(JumpTableInfo && "No jump tables");
436  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
437  const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
438
439  const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
440                                         MAI.getPrivateGlobalPrefix();
441  SmallString<60> Name;
442  raw_svector_ostream(Name)
443    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
444  return Ctx.GetOrCreateSymbol(Name.str());
445}
446
447/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
448/// base.
449MCSymbol *MachineFunction::getPICBaseSymbol() const {
450  const MCAsmInfo &MAI = *Target.getMCAsmInfo();
451  return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
452                               Twine(getFunctionNumber())+"$pb");
453}
454
455//===----------------------------------------------------------------------===//
456//  MachineFrameInfo implementation
457//===----------------------------------------------------------------------===//
458
459/// ensureMaxAlignment - Make sure the function is at least Align bytes
460/// aligned.
461void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
462  if (!TFI.isStackRealignable() || !RealignOption)
463    assert(Align <= TFI.getStackAlignment() &&
464           "For targets without stack realignment, Align is out of limit!");
465  if (MaxAlignment < Align) MaxAlignment = Align;
466}
467
468/// clampStackAlignment - Clamp the alignment if requested and emit a warning.
469static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
470                                           unsigned StackAlign) {
471  if (!ShouldClamp || Align <= StackAlign)
472    return Align;
473  DEBUG(dbgs() << "Warning: requested alignment " << Align
474               << " exceeds the stack alignment " << StackAlign
475               << " when stack realignment is off" << '\n');
476  return StackAlign;
477}
478
479/// CreateStackObject - Create a new statically sized stack object, returning
480/// a nonnegative identifier to represent it.
481///
482int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
483                      bool isSS, bool MayNeedSP, const AllocaInst *Alloca) {
484  assert(Size != 0 && "Cannot allocate zero size stack objects!");
485  Alignment = clampStackAlignment(!TFI.isStackRealignable() || !RealignOption,
486                                  Alignment, TFI.getStackAlignment());
487  Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, MayNeedSP,
488                                Alloca));
489  int Index = (int)Objects.size() - NumFixedObjects - 1;
490  assert(Index >= 0 && "Bad frame index!");
491  ensureMaxAlignment(Alignment);
492  return Index;
493}
494
495/// CreateSpillStackObject - Create a new statically sized stack object that
496/// represents a spill slot, returning a nonnegative identifier to represent
497/// it.
498///
499int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
500                                             unsigned Alignment) {
501  Alignment = clampStackAlignment(!TFI.isStackRealignable() || !RealignOption,
502                                  Alignment, TFI.getStackAlignment());
503  CreateStackObject(Size, Alignment, true, false);
504  int Index = (int)Objects.size() - NumFixedObjects - 1;
505  ensureMaxAlignment(Alignment);
506  return Index;
507}
508
509/// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
510/// variable sized object has been created.  This must be created whenever a
511/// variable sized object is created, whether or not the index returned is
512/// actually used.
513///
514int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment) {
515  HasVarSizedObjects = true;
516  Alignment = clampStackAlignment(!TFI.isStackRealignable() || !RealignOption,
517                                  Alignment, TFI.getStackAlignment());
518  Objects.push_back(StackObject(0, Alignment, 0, false, false, true, 0));
519  ensureMaxAlignment(Alignment);
520  return (int)Objects.size()-NumFixedObjects-1;
521}
522
523/// CreateFixedObject - Create a new object at a fixed location on the stack.
524/// All fixed objects should be created before other objects are created for
525/// efficiency. By default, fixed objects are immutable. This returns an
526/// index with a negative value.
527///
528int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
529                                        bool Immutable) {
530  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
531  // The alignment of the frame index can be determined from its offset from
532  // the incoming frame position.  If the frame object is at offset 32 and
533  // the stack is guaranteed to be 16-byte aligned, then we know that the
534  // object is 16-byte aligned.
535  unsigned StackAlign = TFI.getStackAlignment();
536  unsigned Align = MinAlign(SPOffset, StackAlign);
537  Align = clampStackAlignment(!TFI.isStackRealignable() || !RealignOption,
538                              Align, TFI.getStackAlignment());
539  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
540                                              /*isSS*/   false,
541                                              /*NeedSP*/ false,
542                                              /*Alloca*/ 0));
543  return -++NumFixedObjects;
544}
545
546
547BitVector
548MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
549  assert(MBB && "MBB must be valid");
550  const MachineFunction *MF = MBB->getParent();
551  assert(MF && "MBB must be part of a MachineFunction");
552  const TargetMachine &TM = MF->getTarget();
553  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
554  BitVector BV(TRI->getNumRegs());
555
556  // Before CSI is calculated, no registers are considered pristine. They can be
557  // freely used and PEI will make sure they are saved.
558  if (!isCalleeSavedInfoValid())
559    return BV;
560
561  for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
562    BV.set(*CSR);
563
564  // The entry MBB always has all CSRs pristine.
565  if (MBB == &MF->front())
566    return BV;
567
568  // On other MBBs the saved CSRs are not pristine.
569  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
570  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
571         E = CSI.end(); I != E; ++I)
572    BV.reset(I->getReg());
573
574  return BV;
575}
576
577unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
578  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
579  const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
580  unsigned MaxAlign = getMaxAlignment();
581  int Offset = 0;
582
583  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
584  // It really should be refactored to share code. Until then, changes
585  // should keep in mind that there's tight coupling between the two.
586
587  for (int i = getObjectIndexBegin(); i != 0; ++i) {
588    int FixedOff = -getObjectOffset(i);
589    if (FixedOff > Offset) Offset = FixedOff;
590  }
591  for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
592    if (isDeadObjectIndex(i))
593      continue;
594    Offset += getObjectSize(i);
595    unsigned Align = getObjectAlignment(i);
596    // Adjust to alignment boundary
597    Offset = (Offset+Align-1)/Align*Align;
598
599    MaxAlign = std::max(Align, MaxAlign);
600  }
601
602  if (adjustsStack() && TFI->hasReservedCallFrame(MF))
603    Offset += getMaxCallFrameSize();
604
605  // Round up the size to a multiple of the alignment.  If the function has
606  // any calls or alloca's, align to the target's StackAlignment value to
607  // ensure that the callee's frame or the alloca data is suitably aligned;
608  // otherwise, for leaf functions, align to the TransientStackAlignment
609  // value.
610  unsigned StackAlign;
611  if (adjustsStack() || hasVarSizedObjects() ||
612      (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
613    StackAlign = TFI->getStackAlignment();
614  else
615    StackAlign = TFI->getTransientStackAlignment();
616
617  // If the frame pointer is eliminated, all frame offsets will be relative to
618  // SP not FP. Align to MaxAlign so this works.
619  StackAlign = std::max(StackAlign, MaxAlign);
620  unsigned AlignMask = StackAlign - 1;
621  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
622
623  return (unsigned)Offset;
624}
625
626void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
627  if (Objects.empty()) return;
628
629  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
630  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
631
632  OS << "Frame Objects:\n";
633
634  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
635    const StackObject &SO = Objects[i];
636    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
637    if (SO.Size == ~0ULL) {
638      OS << "dead\n";
639      continue;
640    }
641    if (SO.Size == 0)
642      OS << "variable sized";
643    else
644      OS << "size=" << SO.Size;
645    OS << ", align=" << SO.Alignment;
646
647    if (i < NumFixedObjects)
648      OS << ", fixed";
649    if (i < NumFixedObjects || SO.SPOffset != -1) {
650      int64_t Off = SO.SPOffset - ValOffset;
651      OS << ", at location [SP";
652      if (Off > 0)
653        OS << "+" << Off;
654      else if (Off < 0)
655        OS << Off;
656      OS << "]";
657    }
658    OS << "\n";
659  }
660}
661
662#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
663void MachineFrameInfo::dump(const MachineFunction &MF) const {
664  print(MF, dbgs());
665}
666#endif
667
668//===----------------------------------------------------------------------===//
669//  MachineJumpTableInfo implementation
670//===----------------------------------------------------------------------===//
671
672/// getEntrySize - Return the size of each entry in the jump table.
673unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
674  // The size of a jump table entry is 4 bytes unless the entry is just the
675  // address of a block, in which case it is the pointer size.
676  switch (getEntryKind()) {
677  case MachineJumpTableInfo::EK_BlockAddress:
678    return TD.getPointerSize();
679  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
680    return 8;
681  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
682  case MachineJumpTableInfo::EK_LabelDifference32:
683  case MachineJumpTableInfo::EK_Custom32:
684    return 4;
685  case MachineJumpTableInfo::EK_Inline:
686    return 0;
687  }
688  llvm_unreachable("Unknown jump table encoding!");
689}
690
691/// getEntryAlignment - Return the alignment of each entry in the jump table.
692unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
693  // The alignment of a jump table entry is the alignment of int32 unless the
694  // entry is just the address of a block, in which case it is the pointer
695  // alignment.
696  switch (getEntryKind()) {
697  case MachineJumpTableInfo::EK_BlockAddress:
698    return TD.getPointerABIAlignment();
699  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
700    return TD.getABIIntegerTypeAlignment(64);
701  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
702  case MachineJumpTableInfo::EK_LabelDifference32:
703  case MachineJumpTableInfo::EK_Custom32:
704    return TD.getABIIntegerTypeAlignment(32);
705  case MachineJumpTableInfo::EK_Inline:
706    return 1;
707  }
708  llvm_unreachable("Unknown jump table encoding!");
709}
710
711/// createJumpTableIndex - Create a new jump table entry in the jump table info.
712///
713unsigned MachineJumpTableInfo::createJumpTableIndex(
714                               const std::vector<MachineBasicBlock*> &DestBBs) {
715  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
716  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
717  return JumpTables.size()-1;
718}
719
720/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
721/// the jump tables to branch to New instead.
722bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
723                                                  MachineBasicBlock *New) {
724  assert(Old != New && "Not making a change?");
725  bool MadeChange = false;
726  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
727    ReplaceMBBInJumpTable(i, Old, New);
728  return MadeChange;
729}
730
731/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
732/// the jump table to branch to New instead.
733bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
734                                                 MachineBasicBlock *Old,
735                                                 MachineBasicBlock *New) {
736  assert(Old != New && "Not making a change?");
737  bool MadeChange = false;
738  MachineJumpTableEntry &JTE = JumpTables[Idx];
739  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
740    if (JTE.MBBs[j] == Old) {
741      JTE.MBBs[j] = New;
742      MadeChange = true;
743    }
744  return MadeChange;
745}
746
747void MachineJumpTableInfo::print(raw_ostream &OS) const {
748  if (JumpTables.empty()) return;
749
750  OS << "Jump Tables:\n";
751
752  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
753    OS << "  jt#" << i << ": ";
754    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
755      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
756  }
757
758  OS << '\n';
759}
760
761#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
762void MachineJumpTableInfo::dump() const { print(dbgs()); }
763#endif
764
765
766//===----------------------------------------------------------------------===//
767//  MachineConstantPool implementation
768//===----------------------------------------------------------------------===//
769
770void MachineConstantPoolValue::anchor() { }
771
772Type *MachineConstantPoolEntry::getType() const {
773  if (isMachineConstantPoolEntry())
774    return Val.MachineCPVal->getType();
775  return Val.ConstVal->getType();
776}
777
778
779unsigned MachineConstantPoolEntry::getRelocationInfo() const {
780  if (isMachineConstantPoolEntry())
781    return Val.MachineCPVal->getRelocationInfo();
782  return Val.ConstVal->getRelocationInfo();
783}
784
785MachineConstantPool::~MachineConstantPool() {
786  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
787    if (Constants[i].isMachineConstantPoolEntry())
788      delete Constants[i].Val.MachineCPVal;
789  for (DenseSet<MachineConstantPoolValue*>::iterator I =
790       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
791       I != E; ++I)
792    delete *I;
793}
794
795/// CanShareConstantPoolEntry - Test whether the given two constants
796/// can be allocated the same constant pool entry.
797static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
798                                      const DataLayout *TD) {
799  // Handle the trivial case quickly.
800  if (A == B) return true;
801
802  // If they have the same type but weren't the same constant, quickly
803  // reject them.
804  if (A->getType() == B->getType()) return false;
805
806  // We can't handle structs or arrays.
807  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
808      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
809    return false;
810
811  // For now, only support constants with the same size.
812  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
813  if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
814      StoreSize > 128)
815    return false;
816
817  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
818
819  // Try constant folding a bitcast of both instructions to an integer.  If we
820  // get two identical ConstantInt's, then we are good to share them.  We use
821  // the constant folding APIs to do this so that we get the benefit of
822  // DataLayout.
823  if (isa<PointerType>(A->getType()))
824    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
825                                 const_cast<Constant*>(A), TD);
826  else if (A->getType() != IntTy)
827    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
828                                 const_cast<Constant*>(A), TD);
829  if (isa<PointerType>(B->getType()))
830    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
831                                 const_cast<Constant*>(B), TD);
832  else if (B->getType() != IntTy)
833    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
834                                 const_cast<Constant*>(B), TD);
835
836  return A == B;
837}
838
839/// getConstantPoolIndex - Create a new entry in the constant pool or return
840/// an existing one.  User must specify the log2 of the minimum required
841/// alignment for the object.
842///
843unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
844                                                   unsigned Alignment) {
845  assert(Alignment && "Alignment must be specified!");
846  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
847
848  // Check to see if we already have this constant.
849  //
850  // FIXME, this could be made much more efficient for large constant pools.
851  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
852    if (!Constants[i].isMachineConstantPoolEntry() &&
853        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
854      if ((unsigned)Constants[i].getAlignment() < Alignment)
855        Constants[i].Alignment = Alignment;
856      return i;
857    }
858
859  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
860  return Constants.size()-1;
861}
862
863unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
864                                                   unsigned Alignment) {
865  assert(Alignment && "Alignment must be specified!");
866  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
867
868  // Check to see if we already have this constant.
869  //
870  // FIXME, this could be made much more efficient for large constant pools.
871  int Idx = V->getExistingMachineCPValue(this, Alignment);
872  if (Idx != -1) {
873    MachineCPVsSharingEntries.insert(V);
874    return (unsigned)Idx;
875  }
876
877  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
878  return Constants.size()-1;
879}
880
881void MachineConstantPool::print(raw_ostream &OS) const {
882  if (Constants.empty()) return;
883
884  OS << "Constant Pool:\n";
885  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
886    OS << "  cp#" << i << ": ";
887    if (Constants[i].isMachineConstantPoolEntry())
888      Constants[i].Val.MachineCPVal->print(OS);
889    else
890      OS << *(const Value*)Constants[i].Val.ConstVal;
891    OS << ", align=" << Constants[i].getAlignment();
892    OS << "\n";
893  }
894}
895
896#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
897void MachineConstantPool::dump() const { print(dbgs()); }
898#endif
899