MachineFunction.cpp revision 263765 
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                                                const AllocaInst *Alloca) {
530  HasVarSizedObjects = true;
531  Alignment =
532    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
533                          !RealignOption,
534                        Alignment, getFrameLowering()->getStackAlignment());
535  Objects.push_back(StackObject(0, Alignment, 0, false, false, true, Alloca));
536  ensureMaxAlignment(Alignment);
537  return (int)Objects.size()-NumFixedObjects-1;
538}
539
540/// CreateFixedObject - Create a new object at a fixed location on the stack.
541/// All fixed objects should be created before other objects are created for
542/// efficiency. By default, fixed objects are immutable. This returns an
543/// index with a negative value.
544///
545int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
546                                        bool Immutable) {
547  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
548  // The alignment of the frame index can be determined from its offset from
549  // the incoming frame position.  If the frame object is at offset 32 and
550  // the stack is guaranteed to be 16-byte aligned, then we know that the
551  // object is 16-byte aligned.
552  unsigned StackAlign = getFrameLowering()->getStackAlignment();
553  unsigned Align = MinAlign(SPOffset, StackAlign);
554  Align =
555    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
556                          !RealignOption,
557                        Align, getFrameLowering()->getStackAlignment());
558  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
559                                              /*isSS*/   false,
560                                              /*NeedSP*/ false,
561                                              /*Alloca*/ 0));
562  return -++NumFixedObjects;
563}
564
565
566BitVector
567MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
568  assert(MBB && "MBB must be valid");
569  const MachineFunction *MF = MBB->getParent();
570  assert(MF && "MBB must be part of a MachineFunction");
571  const TargetMachine &TM = MF->getTarget();
572  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
573  BitVector BV(TRI->getNumRegs());
574
575  // Before CSI is calculated, no registers are considered pristine. They can be
576  // freely used and PEI will make sure they are saved.
577  if (!isCalleeSavedInfoValid())
578    return BV;
579
580  for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
581    BV.set(*CSR);
582
583  // The entry MBB always has all CSRs pristine.
584  if (MBB == &MF->front())
585    return BV;
586
587  // On other MBBs the saved CSRs are not pristine.
588  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
589  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
590         E = CSI.end(); I != E; ++I)
591    BV.reset(I->getReg());
592
593  return BV;
594}
595
596unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
597  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
598  const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
599  unsigned MaxAlign = getMaxAlignment();
600  int Offset = 0;
601
602  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
603  // It really should be refactored to share code. Until then, changes
604  // should keep in mind that there's tight coupling between the two.
605
606  for (int i = getObjectIndexBegin(); i != 0; ++i) {
607    int FixedOff = -getObjectOffset(i);
608    if (FixedOff > Offset) Offset = FixedOff;
609  }
610  for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
611    if (isDeadObjectIndex(i))
612      continue;
613    Offset += getObjectSize(i);
614    unsigned Align = getObjectAlignment(i);
615    // Adjust to alignment boundary
616    Offset = (Offset+Align-1)/Align*Align;
617
618    MaxAlign = std::max(Align, MaxAlign);
619  }
620
621  if (adjustsStack() && TFI->hasReservedCallFrame(MF))
622    Offset += getMaxCallFrameSize();
623
624  // Round up the size to a multiple of the alignment.  If the function has
625  // any calls or alloca's, align to the target's StackAlignment value to
626  // ensure that the callee's frame or the alloca data is suitably aligned;
627  // otherwise, for leaf functions, align to the TransientStackAlignment
628  // value.
629  unsigned StackAlign;
630  if (adjustsStack() || hasVarSizedObjects() ||
631      (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
632    StackAlign = TFI->getStackAlignment();
633  else
634    StackAlign = TFI->getTransientStackAlignment();
635
636  // If the frame pointer is eliminated, all frame offsets will be relative to
637  // SP not FP. Align to MaxAlign so this works.
638  StackAlign = std::max(StackAlign, MaxAlign);
639  unsigned AlignMask = StackAlign - 1;
640  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
641
642  return (unsigned)Offset;
643}
644
645void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
646  if (Objects.empty()) return;
647
648  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
649  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
650
651  OS << "Frame Objects:\n";
652
653  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
654    const StackObject &SO = Objects[i];
655    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
656    if (SO.Size == ~0ULL) {
657      OS << "dead\n";
658      continue;
659    }
660    if (SO.Size == 0)
661      OS << "variable sized";
662    else
663      OS << "size=" << SO.Size;
664    OS << ", align=" << SO.Alignment;
665
666    if (i < NumFixedObjects)
667      OS << ", fixed";
668    if (i < NumFixedObjects || SO.SPOffset != -1) {
669      int64_t Off = SO.SPOffset - ValOffset;
670      OS << ", at location [SP";
671      if (Off > 0)
672        OS << "+" << Off;
673      else if (Off < 0)
674        OS << Off;
675      OS << "]";
676    }
677    OS << "\n";
678  }
679}
680
681#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
682void MachineFrameInfo::dump(const MachineFunction &MF) const {
683  print(MF, dbgs());
684}
685#endif
686
687//===----------------------------------------------------------------------===//
688//  MachineJumpTableInfo implementation
689//===----------------------------------------------------------------------===//
690
691/// getEntrySize - Return the size of each entry in the jump table.
692unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
693  // The size of a jump table entry is 4 bytes unless the entry is just the
694  // address of a block, in which case it is the pointer size.
695  switch (getEntryKind()) {
696  case MachineJumpTableInfo::EK_BlockAddress:
697    return TD.getPointerSize();
698  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
699    return 8;
700  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
701  case MachineJumpTableInfo::EK_LabelDifference32:
702  case MachineJumpTableInfo::EK_Custom32:
703    return 4;
704  case MachineJumpTableInfo::EK_Inline:
705    return 0;
706  }
707  llvm_unreachable("Unknown jump table encoding!");
708}
709
710/// getEntryAlignment - Return the alignment of each entry in the jump table.
711unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
712  // The alignment of a jump table entry is the alignment of int32 unless the
713  // entry is just the address of a block, in which case it is the pointer
714  // alignment.
715  switch (getEntryKind()) {
716  case MachineJumpTableInfo::EK_BlockAddress:
717    return TD.getPointerABIAlignment();
718  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
719    return TD.getABIIntegerTypeAlignment(64);
720  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
721  case MachineJumpTableInfo::EK_LabelDifference32:
722  case MachineJumpTableInfo::EK_Custom32:
723    return TD.getABIIntegerTypeAlignment(32);
724  case MachineJumpTableInfo::EK_Inline:
725    return 1;
726  }
727  llvm_unreachable("Unknown jump table encoding!");
728}
729
730/// createJumpTableIndex - Create a new jump table entry in the jump table info.
731///
732unsigned MachineJumpTableInfo::createJumpTableIndex(
733                               const std::vector<MachineBasicBlock*> &DestBBs) {
734  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
735  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
736  return JumpTables.size()-1;
737}
738
739/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
740/// the jump tables to branch to New instead.
741bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
742                                                  MachineBasicBlock *New) {
743  assert(Old != New && "Not making a change?");
744  bool MadeChange = false;
745  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
746    ReplaceMBBInJumpTable(i, Old, New);
747  return MadeChange;
748}
749
750/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
751/// the jump table to branch to New instead.
752bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
753                                                 MachineBasicBlock *Old,
754                                                 MachineBasicBlock *New) {
755  assert(Old != New && "Not making a change?");
756  bool MadeChange = false;
757  MachineJumpTableEntry &JTE = JumpTables[Idx];
758  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
759    if (JTE.MBBs[j] == Old) {
760      JTE.MBBs[j] = New;
761      MadeChange = true;
762    }
763  return MadeChange;
764}
765
766void MachineJumpTableInfo::print(raw_ostream &OS) const {
767  if (JumpTables.empty()) return;
768
769  OS << "Jump Tables:\n";
770
771  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
772    OS << "  jt#" << i << ": ";
773    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
774      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
775  }
776
777  OS << '\n';
778}
779
780#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
781void MachineJumpTableInfo::dump() const { print(dbgs()); }
782#endif
783
784
785//===----------------------------------------------------------------------===//
786//  MachineConstantPool implementation
787//===----------------------------------------------------------------------===//
788
789void MachineConstantPoolValue::anchor() { }
790
791const DataLayout *MachineConstantPool::getDataLayout() const {
792  return TM.getDataLayout();
793}
794
795Type *MachineConstantPoolEntry::getType() const {
796  if (isMachineConstantPoolEntry())
797    return Val.MachineCPVal->getType();
798  return Val.ConstVal->getType();
799}
800
801
802unsigned MachineConstantPoolEntry::getRelocationInfo() const {
803  if (isMachineConstantPoolEntry())
804    return Val.MachineCPVal->getRelocationInfo();
805  return Val.ConstVal->getRelocationInfo();
806}
807
808MachineConstantPool::~MachineConstantPool() {
809  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
810    if (Constants[i].isMachineConstantPoolEntry())
811      delete Constants[i].Val.MachineCPVal;
812  for (DenseSet<MachineConstantPoolValue*>::iterator I =
813       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
814       I != E; ++I)
815    delete *I;
816}
817
818/// CanShareConstantPoolEntry - Test whether the given two constants
819/// can be allocated the same constant pool entry.
820static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
821                                      const DataLayout *TD) {
822  // Handle the trivial case quickly.
823  if (A == B) return true;
824
825  // If they have the same type but weren't the same constant, quickly
826  // reject them.
827  if (A->getType() == B->getType()) return false;
828
829  // We can't handle structs or arrays.
830  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
831      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
832    return false;
833
834  // For now, only support constants with the same size.
835  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
836  if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
837      StoreSize > 128)
838    return false;
839
840  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
841
842  // Try constant folding a bitcast of both instructions to an integer.  If we
843  // get two identical ConstantInt's, then we are good to share them.  We use
844  // the constant folding APIs to do this so that we get the benefit of
845  // DataLayout.
846  if (isa<PointerType>(A->getType()))
847    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
848                                 const_cast<Constant*>(A), TD);
849  else if (A->getType() != IntTy)
850    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
851                                 const_cast<Constant*>(A), TD);
852  if (isa<PointerType>(B->getType()))
853    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
854                                 const_cast<Constant*>(B), TD);
855  else if (B->getType() != IntTy)
856    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
857                                 const_cast<Constant*>(B), TD);
858
859  return A == B;
860}
861
862/// getConstantPoolIndex - Create a new entry in the constant pool or return
863/// an existing one.  User must specify the log2 of the minimum required
864/// alignment for the object.
865///
866unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
867                                                   unsigned Alignment) {
868  assert(Alignment && "Alignment must be specified!");
869  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
870
871  // Check to see if we already have this constant.
872  //
873  // FIXME, this could be made much more efficient for large constant pools.
874  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
875    if (!Constants[i].isMachineConstantPoolEntry() &&
876        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
877                                  getDataLayout())) {
878      if ((unsigned)Constants[i].getAlignment() < Alignment)
879        Constants[i].Alignment = Alignment;
880      return i;
881    }
882
883  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
884  return Constants.size()-1;
885}
886
887unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
888                                                   unsigned Alignment) {
889  assert(Alignment && "Alignment must be specified!");
890  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
891
892  // Check to see if we already have this constant.
893  //
894  // FIXME, this could be made much more efficient for large constant pools.
895  int Idx = V->getExistingMachineCPValue(this, Alignment);
896  if (Idx != -1) {
897    MachineCPVsSharingEntries.insert(V);
898    return (unsigned)Idx;
899  }
900
901  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
902  return Constants.size()-1;
903}
904
905void MachineConstantPool::print(raw_ostream &OS) const {
906  if (Constants.empty()) return;
907
908  OS << "Constant Pool:\n";
909  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
910    OS << "  cp#" << i << ": ";
911    if (Constants[i].isMachineConstantPoolEntry())
912      Constants[i].Val.MachineCPVal->print(OS);
913    else
914      WriteAsOperand(OS, Constants[i].Val.ConstVal, /*PrintType=*/false);
915    OS << ", align=" << Constants[i].getAlignment();
916    OS << "\n";
917  }
918}
919
920#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
921void MachineConstantPool::dump() const { print(dbgs()); }
922#endif
923