MachineFunction.cpp revision 16030402039c222229fe0e64cbc8307964480e31
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/DerivedTypes.h"
17#include "llvm/Function.h"
18#include "llvm/Instructions.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/Config/config.h"
21#include "llvm/CodeGen/MachineConstantPool.h"
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/CodeGen/MachineFunctionPass.h"
24#include "llvm/CodeGen/MachineFrameInfo.h"
25#include "llvm/CodeGen/MachineInstr.h"
26#include "llvm/CodeGen/MachineJumpTableInfo.h"
27#include "llvm/CodeGen/MachineRegisterInfo.h"
28#include "llvm/CodeGen/Passes.h"
29#include "llvm/Target/TargetData.h"
30#include "llvm/Target/TargetLowering.h"
31#include "llvm/Target/TargetMachine.h"
32#include "llvm/Target/TargetFrameInfo.h"
33#include "llvm/Support/Compiler.h"
34#include "llvm/Support/GraphWriter.h"
35#include "llvm/Support/raw_ostream.h"
36using namespace llvm;
37
38namespace {
39  struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
40    static char ID;
41
42    raw_ostream &OS;
43    const std::string Banner;
44
45    Printer(raw_ostream &os, const std::string &banner)
46      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
47
48    const char *getPassName() const { return "MachineFunction Printer"; }
49
50    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
51      AU.setPreservesAll();
52      MachineFunctionPass::getAnalysisUsage(AU);
53    }
54
55    bool runOnMachineFunction(MachineFunction &MF) {
56      OS << Banner;
57      MF.print(OS);
58      return false;
59    }
60  };
61  char Printer::ID = 0;
62}
63
64/// Returns a newly-created MachineFunction Printer pass. The default banner is
65/// empty.
66///
67FunctionPass *llvm::createMachineFunctionPrinterPass(raw_ostream &OS,
68                                                     const std::string &Banner){
69  return new Printer(OS, Banner);
70}
71
72//===---------------------------------------------------------------------===//
73// MachineFunction implementation
74//===---------------------------------------------------------------------===//
75
76// Out of line virtual method.
77MachineFunctionInfo::~MachineFunctionInfo() {}
78
79void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
80  MBB->getParent()->DeleteMachineBasicBlock(MBB);
81}
82
83MachineFunction::MachineFunction(Function *F,
84                                 const TargetMachine &TM)
85  : Fn(F), Target(TM) {
86  if (TM.getRegisterInfo())
87    RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
88                  MachineRegisterInfo(*TM.getRegisterInfo());
89  else
90    RegInfo = 0;
91  MFInfo = 0;
92  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
93                  MachineFrameInfo(*TM.getFrameInfo());
94  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
95                     MachineConstantPool(TM.getTargetData());
96  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
97
98  // Set up jump table.
99  const TargetData &TD = *TM.getTargetData();
100  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
101  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
102  unsigned TyAlignment = IsPic ?
103                       TD.getABITypeAlignment(Type::getInt32Ty(F->getContext()))
104                               : TD.getPointerABIAlignment();
105  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
106                      MachineJumpTableInfo(EntrySize, TyAlignment);
107}
108
109MachineFunction::~MachineFunction() {
110  BasicBlocks.clear();
111  InstructionRecycler.clear(Allocator);
112  BasicBlockRecycler.clear(Allocator);
113  if (RegInfo) {
114    RegInfo->~MachineRegisterInfo();
115    Allocator.Deallocate(RegInfo);
116  }
117  if (MFInfo) {
118    MFInfo->~MachineFunctionInfo();
119    Allocator.Deallocate(MFInfo);
120  }
121  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
122  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
123  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
124}
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 TargetInstrDesc &TID,
174                                    DebugLoc DL, bool NoImp) {
175  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
176    MachineInstr(TID, 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 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///
191void
192MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
193  MI->~MachineInstr();
194  InstructionRecycler.Deallocate(Allocator, MI);
195}
196
197/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
198/// instead of `new MachineBasicBlock'.
199///
200MachineBasicBlock *
201MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
202  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
203             MachineBasicBlock(*this, bb);
204}
205
206/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
207///
208void
209MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
210  assert(MBB->getParent() == this && "MBB parent mismatch!");
211  MBB->~MachineBasicBlock();
212  BasicBlockRecycler.Deallocate(Allocator, MBB);
213}
214
215MachineMemOperand *
216MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
217                                      int64_t o, uint64_t s,
218                                      unsigned base_alignment) {
219  return new (Allocator.Allocate<MachineMemOperand>())
220             MachineMemOperand(v, f, o, s, base_alignment);
221}
222
223MachineMemOperand *
224MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
225                                      int64_t Offset, uint64_t Size) {
226  return new (Allocator.Allocate<MachineMemOperand>())
227             MachineMemOperand(MMO->getValue(), MMO->getFlags(),
228                               int64_t(uint64_t(MMO->getOffset()) +
229                                       uint64_t(Offset)),
230                               Size, MMO->getBaseAlignment());
231}
232
233MachineInstr::mmo_iterator
234MachineFunction::allocateMemRefsArray(unsigned long Num) {
235  return Allocator.Allocate<MachineMemOperand *>(Num);
236}
237
238void MachineFunction::dump() const {
239  print(errs());
240}
241
242void MachineFunction::print(raw_ostream &OS) const {
243  OS << "# Machine code for " << Fn->getName() << "():\n";
244
245  // Print Frame Information
246  FrameInfo->print(*this, OS);
247
248  // Print JumpTable Information
249  JumpTableInfo->print(OS);
250
251  // Print Constant Pool
252  ConstantPool->print(OS);
253
254  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
255
256  if (RegInfo && !RegInfo->livein_empty()) {
257    OS << "Live Ins:";
258    for (MachineRegisterInfo::livein_iterator
259         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
260      if (TRI)
261        OS << " " << TRI->getName(I->first);
262      else
263        OS << " Reg #" << I->first;
264
265      if (I->second)
266        OS << " in VR#" << I->second << ' ';
267    }
268    OS << '\n';
269  }
270  if (RegInfo && !RegInfo->liveout_empty()) {
271    OS << "Live Outs:";
272    for (MachineRegisterInfo::liveout_iterator
273         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
274      if (TRI)
275        OS << ' ' << TRI->getName(*I);
276      else
277        OS << " Reg #" << *I;
278    OS << '\n';
279  }
280
281  for (const_iterator BB = begin(), E = end(); BB != E; ++BB)
282    BB->print(OS);
283
284  OS << "\n# End machine code for " << Fn->getName() << "().\n\n";
285}
286
287namespace llvm {
288  template<>
289  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
290    static std::string getGraphName(const MachineFunction *F) {
291      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
292    }
293
294    static std::string getNodeLabel(const MachineBasicBlock *Node,
295                                    const MachineFunction *Graph,
296                                    bool ShortNames) {
297      if (ShortNames && Node->getBasicBlock() &&
298          !Node->getBasicBlock()->getName().empty())
299        return Node->getBasicBlock()->getNameStr() + ":";
300
301      std::string OutStr;
302      {
303        raw_string_ostream OSS(OutStr);
304
305        if (ShortNames)
306          OSS << Node->getNumber() << ':';
307        else
308          Node->print(OSS);
309      }
310
311      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
312
313      // Process string output to make it nicer...
314      for (unsigned i = 0; i != OutStr.length(); ++i)
315        if (OutStr[i] == '\n') {                            // Left justify
316          OutStr[i] = '\\';
317          OutStr.insert(OutStr.begin()+i+1, 'l');
318        }
319      return OutStr;
320    }
321  };
322}
323
324void MachineFunction::viewCFG() const
325{
326#ifndef NDEBUG
327  ViewGraph(this, "mf" + getFunction()->getNameStr());
328#else
329  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
330         << "systems with Graphviz or gv!\n";
331#endif // NDEBUG
332}
333
334void MachineFunction::viewCFGOnly() const
335{
336#ifndef NDEBUG
337  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
338#else
339  errs() << "SelectionDAG::viewGraph is only available in debug builds on "
340         << "systems with Graphviz or gv!\n";
341#endif // NDEBUG
342}
343
344/// addLiveIn - Add the specified physical register as a live-in value and
345/// create a corresponding virtual register for it.
346unsigned MachineFunction::addLiveIn(unsigned PReg,
347                                    const TargetRegisterClass *RC) {
348  assert(RC->contains(PReg) && "Not the correct regclass!");
349  unsigned VReg = getRegInfo().createVirtualRegister(RC);
350  getRegInfo().addLiveIn(PReg, VReg);
351  return VReg;
352}
353
354/// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object.
355DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const {
356  unsigned Idx = DL.getIndex();
357  assert(Idx < DebugLocInfo.DebugLocations.size() &&
358         "Invalid index into debug locations!");
359  return DebugLocInfo.DebugLocations[Idx];
360}
361
362//===----------------------------------------------------------------------===//
363//  MachineFrameInfo implementation
364//===----------------------------------------------------------------------===//
365
366/// CreateFixedObject - Create a new object at a fixed location on the stack.
367/// All fixed objects should be created before other objects are created for
368/// efficiency. By default, fixed objects are immutable. This returns an
369/// index with a negative value.
370///
371int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
372                                        bool Immutable) {
373  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
374  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
375  return -++NumFixedObjects;
376}
377
378
379BitVector
380MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
381  assert(MBB && "MBB must be valid");
382  const MachineFunction *MF = MBB->getParent();
383  assert(MF && "MBB must be part of a MachineFunction");
384  const TargetMachine &TM = MF->getTarget();
385  const TargetRegisterInfo *TRI = TM.getRegisterInfo();
386  BitVector BV(TRI->getNumRegs());
387
388  // Before CSI is calculated, no registers are considered pristine. They can be
389  // freely used and PEI will make sure they are saved.
390  if (!isCalleeSavedInfoValid())
391    return BV;
392
393  for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
394    BV.set(*CSR);
395
396  // The entry MBB always has all CSRs pristine.
397  if (MBB == &MF->front())
398    return BV;
399
400  // On other MBBs the saved CSRs are not pristine.
401  const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
402  for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
403         E = CSI.end(); I != E; ++I)
404    BV.reset(I->getReg());
405
406  return BV;
407}
408
409
410void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
411  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
412  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
413
414  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
415    const StackObject &SO = Objects[i];
416    OS << "  <fi#" << (int)(i-NumFixedObjects) << ">: ";
417    if (SO.Size == ~0ULL) {
418      OS << "dead\n";
419      continue;
420    }
421    if (SO.Size == 0)
422      OS << "variable sized";
423    else
424      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
425    OS << " alignment is " << SO.Alignment << " byte"
426       << (SO.Alignment != 1 ? "s," : ",");
427
428    if (i < NumFixedObjects)
429      OS << " fixed";
430    if (i < NumFixedObjects || SO.SPOffset != -1) {
431      int64_t Off = SO.SPOffset - ValOffset;
432      OS << " at location [SP";
433      if (Off > 0)
434        OS << "+" << Off;
435      else if (Off < 0)
436        OS << Off;
437      OS << "]";
438    }
439    OS << "\n";
440  }
441
442  if (HasVarSizedObjects)
443    OS << "  Stack frame contains variable sized objects\n";
444}
445
446void MachineFrameInfo::dump(const MachineFunction &MF) const {
447  print(MF, errs());
448}
449
450//===----------------------------------------------------------------------===//
451//  MachineJumpTableInfo implementation
452//===----------------------------------------------------------------------===//
453
454/// getJumpTableIndex - Create a new jump table entry in the jump table info
455/// or return an existing one.
456///
457unsigned MachineJumpTableInfo::getJumpTableIndex(
458                               const std::vector<MachineBasicBlock*> &DestBBs) {
459  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
460  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
461    if (JumpTables[i].MBBs == DestBBs)
462      return i;
463
464  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
465  return JumpTables.size()-1;
466}
467
468/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
469/// the jump tables to branch to New instead.
470bool
471MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
472                                             MachineBasicBlock *New) {
473  assert(Old != New && "Not making a change?");
474  bool MadeChange = false;
475  for (size_t i = 0, e = JumpTables.size(); i != e; ++i) {
476    MachineJumpTableEntry &JTE = JumpTables[i];
477    for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
478      if (JTE.MBBs[j] == Old) {
479        JTE.MBBs[j] = New;
480        MadeChange = true;
481      }
482  }
483  return MadeChange;
484}
485
486void MachineJumpTableInfo::print(raw_ostream &OS) const {
487  // FIXME: this is lame, maybe we could print out the MBB numbers or something
488  // like {1, 2, 4, 5, 3, 0}
489  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
490    OS << "  <jt#" << i << "> has " << JumpTables[i].MBBs.size()
491       << " entries\n";
492  }
493}
494
495void MachineJumpTableInfo::dump() const { print(errs()); }
496
497
498//===----------------------------------------------------------------------===//
499//  MachineConstantPool implementation
500//===----------------------------------------------------------------------===//
501
502const Type *MachineConstantPoolEntry::getType() const {
503  if (isMachineConstantPoolEntry())
504    return Val.MachineCPVal->getType();
505  return Val.ConstVal->getType();
506}
507
508
509unsigned MachineConstantPoolEntry::getRelocationInfo() const {
510  if (isMachineConstantPoolEntry())
511    return Val.MachineCPVal->getRelocationInfo();
512  return Val.ConstVal->getRelocationInfo();
513}
514
515MachineConstantPool::~MachineConstantPool() {
516  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
517    if (Constants[i].isMachineConstantPoolEntry())
518      delete Constants[i].Val.MachineCPVal;
519}
520
521/// getConstantPoolIndex - Create a new entry in the constant pool or return
522/// an existing one.  User must specify the log2 of the minimum required
523/// alignment for the object.
524///
525unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
526                                                   unsigned Alignment) {
527  assert(Alignment && "Alignment must be specified!");
528  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
529
530  // Check to see if we already have this constant.
531  //
532  // FIXME, this could be made much more efficient for large constant pools.
533  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
534    if (Constants[i].Val.ConstVal == C &&
535        (Constants[i].getAlignment() & (Alignment - 1)) == 0)
536      return i;
537
538  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
539  return Constants.size()-1;
540}
541
542unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
543                                                   unsigned Alignment) {
544  assert(Alignment && "Alignment must be specified!");
545  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
546
547  // Check to see if we already have this constant.
548  //
549  // FIXME, this could be made much more efficient for large constant pools.
550  int Idx = V->getExistingMachineCPValue(this, Alignment);
551  if (Idx != -1)
552    return (unsigned)Idx;
553
554  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
555  return Constants.size()-1;
556}
557
558void MachineConstantPool::print(raw_ostream &OS) const {
559  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
560    OS << "  <cp#" << i << "> is";
561    if (Constants[i].isMachineConstantPoolEntry())
562      Constants[i].Val.MachineCPVal->print(OS);
563    else
564      OS << *(Value*)Constants[i].Val.ConstVal;
565    OS << " , alignment=" << Constants[i].getAlignment();
566    OS << "\n";
567  }
568}
569
570void MachineConstantPool::dump() const { print(errs()); }
571