MachineFunction.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===-- MachineFunction.cpp -----------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Collect native machine code information for a function.  This allows
11// target-specific information about the generated code to be stored with each
12// function.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/CodeGen/MachineFunction.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/Analysis/ConstantFolding.h"
20#include "llvm/CodeGen/MachineConstantPool.h"
21#include "llvm/CodeGen/MachineFrameInfo.h"
22#include "llvm/CodeGen/MachineFunctionPass.h"
23#include "llvm/CodeGen/MachineInstr.h"
24#include "llvm/CodeGen/MachineJumpTableInfo.h"
25#include "llvm/CodeGen/MachineModuleInfo.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/Passes.h"
28#include "llvm/IR/DataLayout.h"
29#include "llvm/IR/DebugInfo.h"
30#include "llvm/IR/Function.h"
31#include "llvm/MC/MCAsmInfo.h"
32#include "llvm/MC/MCContext.h"
33#include "llvm/Support/Debug.h"
34#include "llvm/Support/GraphWriter.h"
35#include "llvm/Support/raw_ostream.h"
36#include "llvm/Target/TargetFrameLowering.h"
37#include "llvm/Target/TargetLowering.h"
38#include "llvm/Target/TargetMachine.h"
39using namespace llvm;
40
41#define DEBUG_TYPE "codegen"
42
43//===----------------------------------------------------------------------===//
44// MachineFunction implementation
45//===----------------------------------------------------------------------===//
46
47// Out of line virtual method.
48MachineFunctionInfo::~MachineFunctionInfo() {}
49
50void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
51  MBB->getParent()->DeleteMachineBasicBlock(MBB);
52}
53
54MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
55                                 unsigned FunctionNum, MachineModuleInfo &mmi,
56                                 GCModuleInfo* gmi)
57  : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
58  if (TM.getRegisterInfo())
59    RegInfo = new (Allocator) MachineRegisterInfo(TM);
60  else
61    RegInfo = nullptr;
62
63  MFInfo = nullptr;
64  FrameInfo =
65    new (Allocator) MachineFrameInfo(TM,!F->hasFnAttribute("no-realign-stack"));
66
67  if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
68                                       Attribute::StackAlignment))
69    FrameInfo->ensureMaxAlignment(Fn->getAttributes().
70                                getStackAlignment(AttributeSet::FunctionIndex));
71
72  ConstantPool = new (Allocator) MachineConstantPool(TM);
73  Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
74
75  // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
76  if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
77                                        Attribute::OptimizeForSize))
78    Alignment = std::max(Alignment,
79                         TM.getTargetLowering()->getPrefFunctionAlignment());
80
81  FunctionNumber = FunctionNum;
82  JumpTableInfo = nullptr;
83}
84
85MachineFunction::~MachineFunction() {
86  // Don't call destructors on MachineInstr and MachineOperand. All of their
87  // memory comes from the BumpPtrAllocator which is about to be purged.
88  //
89  // Do call MachineBasicBlock destructors, it contains std::vectors.
90  for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
91    I->Insts.clearAndLeakNodesUnsafely();
92
93  InstructionRecycler.clear(Allocator);
94  OperandRecycler.clear(Allocator);
95  BasicBlockRecycler.clear(Allocator);
96  if (RegInfo) {
97    RegInfo->~MachineRegisterInfo();
98    Allocator.Deallocate(RegInfo);
99  }
100  if (MFInfo) {
101    MFInfo->~MachineFunctionInfo();
102    Allocator.Deallocate(MFInfo);
103  }
104
105  FrameInfo->~MachineFrameInfo();
106  Allocator.Deallocate(FrameInfo);
107
108  ConstantPool->~MachineConstantPool();
109  Allocator.Deallocate(ConstantPool);
110
111  if (JumpTableInfo) {
112    JumpTableInfo->~MachineJumpTableInfo();
113    Allocator.Deallocate(JumpTableInfo);
114  }
115}
116
117/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
118/// does already exist, allocate one.
119MachineJumpTableInfo *MachineFunction::
120getOrCreateJumpTableInfo(unsigned EntryKind) {
121  if (JumpTableInfo) return JumpTableInfo;
122
123  JumpTableInfo = new (Allocator)
124    MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
125  return JumpTableInfo;
126}
127
128/// Should we be emitting segmented stack stuff for the function
129bool MachineFunction::shouldSplitStack() {
130  return getFunction()->hasFnAttribute("split-stack");
131}
132
133/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
134/// recomputes them.  This guarantees that the MBB numbers are sequential,
135/// dense, and match the ordering of the blocks within the function.  If a
136/// specific MachineBasicBlock is specified, only that block and those after
137/// it are renumbered.
138void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
139  if (empty()) { MBBNumbering.clear(); return; }
140  MachineFunction::iterator MBBI, E = end();
141  if (MBB == nullptr)
142    MBBI = begin();
143  else
144    MBBI = MBB;
145
146  // Figure out the block number this should have.
147  unsigned BlockNo = 0;
148  if (MBBI != begin())
149    BlockNo = std::prev(MBBI)->getNumber() + 1;
150
151  for (; MBBI != E; ++MBBI, ++BlockNo) {
152    if (MBBI->getNumber() != (int)BlockNo) {
153      // Remove use of the old number.
154      if (MBBI->getNumber() != -1) {
155        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
156               "MBB number mismatch!");
157        MBBNumbering[MBBI->getNumber()] = nullptr;
158      }
159
160      // If BlockNo is already taken, set that block's number to -1.
161      if (MBBNumbering[BlockNo])
162        MBBNumbering[BlockNo]->setNumber(-1);
163
164      MBBNumbering[BlockNo] = MBBI;
165      MBBI->setNumber(BlockNo);
166    }
167  }
168
169  // Okay, all the blocks are renumbered.  If we have compactified the block
170  // numbering, shrink MBBNumbering now.
171  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
172  MBBNumbering.resize(BlockNo);
173}
174
175/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
176/// of `new MachineInstr'.
177///
178MachineInstr *
179MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
180                                    DebugLoc DL, bool NoImp) {
181  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
182    MachineInstr(*this, MCID, DL, NoImp);
183}
184
185/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
186/// 'Orig' instruction, identical in all ways except the instruction
187/// has no parent, prev, or next.
188///
189MachineInstr *
190MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
191  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
192             MachineInstr(*this, *Orig);
193}
194
195/// DeleteMachineInstr - Delete the given MachineInstr.
196///
197/// This function also serves as the MachineInstr destructor - the real
198/// ~MachineInstr() destructor must be empty.
199void
200MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
201  // Strip it for parts. The operand array and the MI object itself are
202  // independently recyclable.
203  if (MI->Operands)
204    deallocateOperandArray(MI->CapOperands, MI->Operands);
205  // Don't call ~MachineInstr() which must be trivial anyway because
206  // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
207  // destructors.
208  InstructionRecycler.Deallocate(Allocator, MI);
209}
210
211/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
212/// instead of `new MachineBasicBlock'.
213///
214MachineBasicBlock *
215MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
216  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
217             MachineBasicBlock(*this, bb);
218}
219
220/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
221///
222void
223MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
224  assert(MBB->getParent() == this && "MBB parent mismatch!");
225  MBB->~MachineBasicBlock();
226  BasicBlockRecycler.Deallocate(Allocator, MBB);
227}
228
229MachineMemOperand *
230MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
231                                      uint64_t s, unsigned base_alignment,
232                                      const MDNode *TBAAInfo,
233                                      const MDNode *Ranges) {
234  return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
235                                           TBAAInfo, Ranges);
236}
237
238MachineMemOperand *
239MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
240                                      int64_t Offset, uint64_t Size) {
241  if (MMO->getValue())
242    return new (Allocator)
243               MachineMemOperand(MachinePointerInfo(MMO->getValue(),
244                                                    MMO->getOffset()+Offset),
245                                 MMO->getFlags(), Size,
246                                 MMO->getBaseAlignment(), nullptr);
247  return new (Allocator)
248             MachineMemOperand(MachinePointerInfo(MMO->getPseudoValue(),
249                                                  MMO->getOffset()+Offset),
250                               MMO->getFlags(), Size,
251                               MMO->getBaseAlignment(), nullptr);
252}
253
254MachineInstr::mmo_iterator
255MachineFunction::allocateMemRefsArray(unsigned long Num) {
256  return Allocator.Allocate<MachineMemOperand *>(Num);
257}
258
259std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
260MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
261                                    MachineInstr::mmo_iterator End) {
262  // Count the number of load mem refs.
263  unsigned Num = 0;
264  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
265    if ((*I)->isLoad())
266      ++Num;
267
268  // Allocate a new array and populate it with the load information.
269  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
270  unsigned Index = 0;
271  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
272    if ((*I)->isLoad()) {
273      if (!(*I)->isStore())
274        // Reuse the MMO.
275        Result[Index] = *I;
276      else {
277        // Clone the MMO and unset the store flag.
278        MachineMemOperand *JustLoad =
279          getMachineMemOperand((*I)->getPointerInfo(),
280                               (*I)->getFlags() & ~MachineMemOperand::MOStore,
281                               (*I)->getSize(), (*I)->getBaseAlignment(),
282                               (*I)->getTBAAInfo());
283        Result[Index] = JustLoad;
284      }
285      ++Index;
286    }
287  }
288  return std::make_pair(Result, Result + Num);
289}
290
291std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
292MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
293                                     MachineInstr::mmo_iterator End) {
294  // Count the number of load mem refs.
295  unsigned Num = 0;
296  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
297    if ((*I)->isStore())
298      ++Num;
299
300  // Allocate a new array and populate it with the store information.
301  MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
302  unsigned Index = 0;
303  for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
304    if ((*I)->isStore()) {
305      if (!(*I)->isLoad())
306        // Reuse the MMO.
307        Result[Index] = *I;
308      else {
309        // Clone the MMO and unset the load flag.
310        MachineMemOperand *JustStore =
311          getMachineMemOperand((*I)->getPointerInfo(),
312                               (*I)->getFlags() & ~MachineMemOperand::MOLoad,
313                               (*I)->getSize(), (*I)->getBaseAlignment(),
314                               (*I)->getTBAAInfo());
315        Result[Index] = JustStore;
316      }
317      ++Index;
318    }
319  }
320  return std::make_pair(Result, Result + Num);
321}
322
323#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
324void MachineFunction::dump() const {
325  print(dbgs());
326}
327#endif
328
329StringRef MachineFunction::getName() const {
330  assert(getFunction() && "No function!");
331  return getFunction()->getName();
332}
333
334void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
335  OS << "# Machine code for function " << getName() << ": ";
336  if (RegInfo) {
337    OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
338    if (!RegInfo->tracksLiveness())
339      OS << ", not tracking liveness";
340  }
341  OS << '\n';
342
343  // Print Frame Information
344  FrameInfo->print(*this, OS);
345
346  // Print JumpTable Information
347  if (JumpTableInfo)
348    JumpTableInfo->print(OS);
349
350  // Print Constant Pool
351  ConstantPool->print(OS);
352
353  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
354
355  if (RegInfo && !RegInfo->livein_empty()) {
356    OS << "Function Live Ins: ";
357    for (MachineRegisterInfo::livein_iterator
358         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
359      OS << PrintReg(I->first, TRI);
360      if (I->second)
361        OS << " in " << PrintReg(I->second, TRI);
362      if (std::next(I) != E)
363        OS << ", ";
364    }
365    OS << '\n';
366  }
367
368  for (const auto &BB : *this) {
369    OS << '\n';
370    BB.print(OS, Indexes);
371  }
372
373  OS << "\n# End machine code for function " << getName() << ".\n\n";
374}
375
376namespace llvm {
377  template<>
378  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
379
380  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
381
382    static std::string getGraphName(const MachineFunction *F) {
383      return "CFG for '" + F->getName().str() + "' function";
384    }
385
386    std::string getNodeLabel(const MachineBasicBlock *Node,
387                             const MachineFunction *Graph) {
388      std::string OutStr;
389      {
390        raw_string_ostream OSS(OutStr);
391
392        if (isSimple()) {
393          OSS << "BB#" << Node->getNumber();
394          if (const BasicBlock *BB = Node->getBasicBlock())
395            OSS << ": " << BB->getName();
396        } else
397          Node->print(OSS);
398      }
399
400      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
401
402      // Process string output to make it nicer...
403      for (unsigned i = 0; i != OutStr.length(); ++i)
404        if (OutStr[i] == '\n') {                            // Left justify
405          OutStr[i] = '\\';
406          OutStr.insert(OutStr.begin()+i+1, 'l');
407        }
408      return OutStr;
409    }
410  };
411}
412
413void MachineFunction::viewCFG() const
414{
415#ifndef NDEBUG
416  ViewGraph(this, "mf" + getName());
417#else
418  errs() << "MachineFunction::viewCFG is only available in debug builds on "
419         << "systems with Graphviz or gv!\n";
420#endif // NDEBUG
421}
422
423void MachineFunction::viewCFGOnly() const
424{
425#ifndef NDEBUG
426  ViewGraph(this, "mf" + getName(), true);
427#else
428  errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
429         << "systems with Graphviz or gv!\n";
430#endif // NDEBUG
431}
432
433/// addLiveIn - Add the specified physical register as a live-in value and
434/// create a corresponding virtual register for it.
435unsigned MachineFunction::addLiveIn(unsigned PReg,
436                                    const TargetRegisterClass *RC) {
437  MachineRegisterInfo &MRI = getRegInfo();
438  unsigned VReg = MRI.getLiveInVirtReg(PReg);
439  if (VReg) {
440    const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg);
441    (void)VRegRC;
442    // A physical register can be added several times.
443    // Between two calls, the register class of the related virtual register
444    // may have been constrained to match some operation constraints.
445    // In that case, check that the current register class includes the
446    // physical register and is a sub class of the specified RC.
447    assert((VRegRC == RC || (VRegRC->contains(PReg) &&
448                             RC->hasSubClassEq(VRegRC))) &&
449            "Register class mismatch!");
450    return VReg;
451  }
452  VReg = MRI.createVirtualRegister(RC);
453  MRI.addLiveIn(PReg, VReg);
454  return VReg;
455}
456
457/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
458/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
459/// normal 'L' label is returned.
460MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
461                                        bool isLinkerPrivate) const {
462  const DataLayout *DL = getTarget().getDataLayout();
463  assert(JumpTableInfo && "No jump tables");
464  assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
465
466  const char *Prefix = isLinkerPrivate ? DL->getLinkerPrivateGlobalPrefix() :
467                                         DL->getPrivateGlobalPrefix();
468  SmallString<60> Name;
469  raw_svector_ostream(Name)
470    << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
471  return Ctx.GetOrCreateSymbol(Name.str());
472}
473
474/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
475/// base.
476MCSymbol *MachineFunction::getPICBaseSymbol() const {
477  const DataLayout *DL = getTarget().getDataLayout();
478  return Ctx.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
479                               Twine(getFunctionNumber())+"$pb");
480}
481
482//===----------------------------------------------------------------------===//
483//  MachineFrameInfo implementation
484//===----------------------------------------------------------------------===//
485
486const TargetFrameLowering *MachineFrameInfo::getFrameLowering() const {
487  return TM.getFrameLowering();
488}
489
490/// ensureMaxAlignment - Make sure the function is at least Align bytes
491/// aligned.
492void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
493  if (!getFrameLowering()->isStackRealignable() || !RealignOption)
494    assert(Align <= getFrameLowering()->getStackAlignment() &&
495           "For targets without stack realignment, Align is out of limit!");
496  if (MaxAlignment < Align) MaxAlignment = Align;
497}
498
499/// clampStackAlignment - Clamp the alignment if requested and emit a warning.
500static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
501                                           unsigned StackAlign) {
502  if (!ShouldClamp || Align <= StackAlign)
503    return Align;
504  DEBUG(dbgs() << "Warning: requested alignment " << Align
505               << " exceeds the stack alignment " << StackAlign
506               << " when stack realignment is off" << '\n');
507  return StackAlign;
508}
509
510/// CreateStackObject - Create a new statically sized stack object, returning
511/// a nonnegative identifier to represent it.
512///
513int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
514                      bool isSS, const AllocaInst *Alloca) {
515  assert(Size != 0 && "Cannot allocate zero size stack objects!");
516  Alignment =
517    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
518                          !RealignOption,
519                        Alignment, getFrameLowering()->getStackAlignment());
520  Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, Alloca));
521  int Index = (int)Objects.size() - NumFixedObjects - 1;
522  assert(Index >= 0 && "Bad frame index!");
523  ensureMaxAlignment(Alignment);
524  return Index;
525}
526
527/// CreateSpillStackObject - Create a new statically sized stack object that
528/// represents a spill slot, returning a nonnegative identifier to represent
529/// it.
530///
531int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
532                                             unsigned Alignment) {
533  Alignment =
534    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
535                          !RealignOption,
536                        Alignment, getFrameLowering()->getStackAlignment());
537  CreateStackObject(Size, Alignment, true);
538  int Index = (int)Objects.size() - NumFixedObjects - 1;
539  ensureMaxAlignment(Alignment);
540  return Index;
541}
542
543/// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
544/// variable sized object has been created.  This must be created whenever a
545/// variable sized object is created, whether or not the index returned is
546/// actually used.
547///
548int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment,
549                                                const AllocaInst *Alloca) {
550  HasVarSizedObjects = true;
551  Alignment =
552    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
553                          !RealignOption,
554                        Alignment, getFrameLowering()->getStackAlignment());
555  Objects.push_back(StackObject(0, Alignment, 0, false, false, Alloca));
556  ensureMaxAlignment(Alignment);
557  return (int)Objects.size()-NumFixedObjects-1;
558}
559
560/// CreateFixedObject - Create a new object at a fixed location on the stack.
561/// All fixed objects should be created before other objects are created for
562/// efficiency. By default, fixed objects are immutable. This returns an
563/// index with a negative value.
564///
565int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
566                                        bool Immutable) {
567  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
568  // The alignment of the frame index can be determined from its offset from
569  // the incoming frame position.  If the frame object is at offset 32 and
570  // the stack is guaranteed to be 16-byte aligned, then we know that the
571  // object is 16-byte aligned.
572  unsigned StackAlign = getFrameLowering()->getStackAlignment();
573  unsigned Align = MinAlign(SPOffset, StackAlign);
574  Align =
575    clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
576                          !RealignOption,
577                        Align, getFrameLowering()->getStackAlignment());
578  Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
579                                              /*isSS*/   false,
580                                              /*Alloca*/ nullptr));
581  return -++NumFixedObjects;
582}
583
584
585BitVector
586MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
587  assert(MBB && "MBB must be valid");
588  const MachineFunction *MF = MBB->getParent();
589  assert(MF && "MBB must be part of a MachineFunction");
590  const TargetMachine &TM = MF->getTarget();
591  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
592  BitVector BV(TRI->getNumRegs());
593
594  // Before CSI is calculated, no registers are considered pristine. They can be
595  // freely used and PEI will make sure they are saved.
596  if (!isCalleeSavedInfoValid())
597    return BV;
598
599  for (const MCPhysReg *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
600    BV.set(*CSR);
601
602  // The entry MBB always has all CSRs pristine.
603  if (MBB == &MF->front())
604    return BV;
605
606  // On other MBBs the saved CSRs are not pristine.
607  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
608  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
609         E = CSI.end(); I != E; ++I)
610    BV.reset(I->getReg());
611
612  return BV;
613}
614
615unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
616  const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
617  const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
618  unsigned MaxAlign = getMaxAlignment();
619  int Offset = 0;
620
621  // This code is very, very similar to PEI::calculateFrameObjectOffsets().
622  // It really should be refactored to share code. Until then, changes
623  // should keep in mind that there's tight coupling between the two.
624
625  for (int i = getObjectIndexBegin(); i != 0; ++i) {
626    int FixedOff = -getObjectOffset(i);
627    if (FixedOff > Offset) Offset = FixedOff;
628  }
629  for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
630    if (isDeadObjectIndex(i))
631      continue;
632    Offset += getObjectSize(i);
633    unsigned Align = getObjectAlignment(i);
634    // Adjust to alignment boundary
635    Offset = (Offset+Align-1)/Align*Align;
636
637    MaxAlign = std::max(Align, MaxAlign);
638  }
639
640  if (adjustsStack() && TFI->hasReservedCallFrame(MF))
641    Offset += getMaxCallFrameSize();
642
643  // Round up the size to a multiple of the alignment.  If the function has
644  // any calls or alloca's, align to the target's StackAlignment value to
645  // ensure that the callee's frame or the alloca data is suitably aligned;
646  // otherwise, for leaf functions, align to the TransientStackAlignment
647  // value.
648  unsigned StackAlign;
649  if (adjustsStack() || hasVarSizedObjects() ||
650      (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
651    StackAlign = TFI->getStackAlignment();
652  else
653    StackAlign = TFI->getTransientStackAlignment();
654
655  // If the frame pointer is eliminated, all frame offsets will be relative to
656  // SP not FP. Align to MaxAlign so this works.
657  StackAlign = std::max(StackAlign, MaxAlign);
658  unsigned AlignMask = StackAlign - 1;
659  Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
660
661  return (unsigned)Offset;
662}
663
664void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
665  if (Objects.empty()) return;
666
667  const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
668  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
669
670  OS << "Frame Objects:\n";
671
672  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
673    const StackObject &SO = Objects[i];
674    OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
675    if (SO.Size == ~0ULL) {
676      OS << "dead\n";
677      continue;
678    }
679    if (SO.Size == 0)
680      OS << "variable sized";
681    else
682      OS << "size=" << SO.Size;
683    OS << ", align=" << SO.Alignment;
684
685    if (i < NumFixedObjects)
686      OS << ", fixed";
687    if (i < NumFixedObjects || SO.SPOffset != -1) {
688      int64_t Off = SO.SPOffset - ValOffset;
689      OS << ", at location [SP";
690      if (Off > 0)
691        OS << "+" << Off;
692      else if (Off < 0)
693        OS << Off;
694      OS << "]";
695    }
696    OS << "\n";
697  }
698}
699
700#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
701void MachineFrameInfo::dump(const MachineFunction &MF) const {
702  print(MF, dbgs());
703}
704#endif
705
706//===----------------------------------------------------------------------===//
707//  MachineJumpTableInfo implementation
708//===----------------------------------------------------------------------===//
709
710/// getEntrySize - Return the size of each entry in the jump table.
711unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
712  // The size of a jump table entry is 4 bytes unless the entry is just the
713  // address of a block, in which case it is the pointer size.
714  switch (getEntryKind()) {
715  case MachineJumpTableInfo::EK_BlockAddress:
716    return TD.getPointerSize();
717  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
718    return 8;
719  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
720  case MachineJumpTableInfo::EK_LabelDifference32:
721  case MachineJumpTableInfo::EK_Custom32:
722    return 4;
723  case MachineJumpTableInfo::EK_Inline:
724    return 0;
725  }
726  llvm_unreachable("Unknown jump table encoding!");
727}
728
729/// getEntryAlignment - Return the alignment of each entry in the jump table.
730unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
731  // The alignment of a jump table entry is the alignment of int32 unless the
732  // entry is just the address of a block, in which case it is the pointer
733  // alignment.
734  switch (getEntryKind()) {
735  case MachineJumpTableInfo::EK_BlockAddress:
736    return TD.getPointerABIAlignment();
737  case MachineJumpTableInfo::EK_GPRel64BlockAddress:
738    return TD.getABIIntegerTypeAlignment(64);
739  case MachineJumpTableInfo::EK_GPRel32BlockAddress:
740  case MachineJumpTableInfo::EK_LabelDifference32:
741  case MachineJumpTableInfo::EK_Custom32:
742    return TD.getABIIntegerTypeAlignment(32);
743  case MachineJumpTableInfo::EK_Inline:
744    return 1;
745  }
746  llvm_unreachable("Unknown jump table encoding!");
747}
748
749/// createJumpTableIndex - Create a new jump table entry in the jump table info.
750///
751unsigned MachineJumpTableInfo::createJumpTableIndex(
752                               const std::vector<MachineBasicBlock*> &DestBBs) {
753  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
754  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
755  return JumpTables.size()-1;
756}
757
758/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
759/// the jump tables to branch to New instead.
760bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
761                                                  MachineBasicBlock *New) {
762  assert(Old != New && "Not making a change?");
763  bool MadeChange = false;
764  for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
765    ReplaceMBBInJumpTable(i, Old, New);
766  return MadeChange;
767}
768
769/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
770/// the jump table to branch to New instead.
771bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
772                                                 MachineBasicBlock *Old,
773                                                 MachineBasicBlock *New) {
774  assert(Old != New && "Not making a change?");
775  bool MadeChange = false;
776  MachineJumpTableEntry &JTE = JumpTables[Idx];
777  for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
778    if (JTE.MBBs[j] == Old) {
779      JTE.MBBs[j] = New;
780      MadeChange = true;
781    }
782  return MadeChange;
783}
784
785void MachineJumpTableInfo::print(raw_ostream &OS) const {
786  if (JumpTables.empty()) return;
787
788  OS << "Jump Tables:\n";
789
790  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
791    OS << "  jt#" << i << ": ";
792    for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
793      OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
794  }
795
796  OS << '\n';
797}
798
799#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
800void MachineJumpTableInfo::dump() const { print(dbgs()); }
801#endif
802
803
804//===----------------------------------------------------------------------===//
805//  MachineConstantPool implementation
806//===----------------------------------------------------------------------===//
807
808void MachineConstantPoolValue::anchor() { }
809
810const DataLayout *MachineConstantPool::getDataLayout() const {
811  return TM.getDataLayout();
812}
813
814Type *MachineConstantPoolEntry::getType() const {
815  if (isMachineConstantPoolEntry())
816    return Val.MachineCPVal->getType();
817  return Val.ConstVal->getType();
818}
819
820
821unsigned MachineConstantPoolEntry::getRelocationInfo() const {
822  if (isMachineConstantPoolEntry())
823    return Val.MachineCPVal->getRelocationInfo();
824  return Val.ConstVal->getRelocationInfo();
825}
826
827MachineConstantPool::~MachineConstantPool() {
828  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
829    if (Constants[i].isMachineConstantPoolEntry())
830      delete Constants[i].Val.MachineCPVal;
831  for (DenseSet<MachineConstantPoolValue*>::iterator I =
832       MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
833       I != E; ++I)
834    delete *I;
835}
836
837/// CanShareConstantPoolEntry - Test whether the given two constants
838/// can be allocated the same constant pool entry.
839static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
840                                      const DataLayout *TD) {
841  // Handle the trivial case quickly.
842  if (A == B) return true;
843
844  // If they have the same type but weren't the same constant, quickly
845  // reject them.
846  if (A->getType() == B->getType()) return false;
847
848  // We can't handle structs or arrays.
849  if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
850      isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
851    return false;
852
853  // For now, only support constants with the same size.
854  uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
855  if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
856      StoreSize > 128)
857    return false;
858
859  Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
860
861  // Try constant folding a bitcast of both instructions to an integer.  If we
862  // get two identical ConstantInt's, then we are good to share them.  We use
863  // the constant folding APIs to do this so that we get the benefit of
864  // DataLayout.
865  if (isa<PointerType>(A->getType()))
866    A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
867                                 const_cast<Constant*>(A), TD);
868  else if (A->getType() != IntTy)
869    A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
870                                 const_cast<Constant*>(A), TD);
871  if (isa<PointerType>(B->getType()))
872    B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
873                                 const_cast<Constant*>(B), TD);
874  else if (B->getType() != IntTy)
875    B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
876                                 const_cast<Constant*>(B), TD);
877
878  return A == B;
879}
880
881/// getConstantPoolIndex - Create a new entry in the constant pool or return
882/// an existing one.  User must specify the log2 of the minimum required
883/// alignment for the object.
884///
885unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
886                                                   unsigned Alignment) {
887  assert(Alignment && "Alignment must be specified!");
888  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
889
890  // Check to see if we already have this constant.
891  //
892  // FIXME, this could be made much more efficient for large constant pools.
893  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
894    if (!Constants[i].isMachineConstantPoolEntry() &&
895        CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
896                                  getDataLayout())) {
897      if ((unsigned)Constants[i].getAlignment() < Alignment)
898        Constants[i].Alignment = Alignment;
899      return i;
900    }
901
902  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
903  return Constants.size()-1;
904}
905
906unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
907                                                   unsigned Alignment) {
908  assert(Alignment && "Alignment must be specified!");
909  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
910
911  // Check to see if we already have this constant.
912  //
913  // FIXME, this could be made much more efficient for large constant pools.
914  int Idx = V->getExistingMachineCPValue(this, Alignment);
915  if (Idx != -1) {
916    MachineCPVsSharingEntries.insert(V);
917    return (unsigned)Idx;
918  }
919
920  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
921  return Constants.size()-1;
922}
923
924void MachineConstantPool::print(raw_ostream &OS) const {
925  if (Constants.empty()) return;
926
927  OS << "Constant Pool:\n";
928  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
929    OS << "  cp#" << i << ": ";
930    if (Constants[i].isMachineConstantPoolEntry())
931      Constants[i].Val.MachineCPVal->print(OS);
932    else
933      Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false);
934    OS << ", align=" << Constants[i].getAlignment();
935    OS << "\n";
936  }
937}
938
939#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
940void MachineConstantPool::dump() const { print(dbgs()); }
941#endif
942