MachineFunction.cpp revision 275872e79950dafc6699f6502cee52f74b84a22a 
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/MachineFunctionPass.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineInstr.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineRegisterInfo.h"
27#include "llvm/CodeGen/Passes.h"
28#include "llvm/Target/TargetData.h"
29#include "llvm/Target/TargetLowering.h"
30#include "llvm/Target/TargetMachine.h"
31#include "llvm/Target/TargetFrameInfo.h"
32#include "llvm/Support/Compiler.h"
33#include "llvm/Support/GraphWriter.h"
34#include "llvm/Support/raw_ostream.h"
35#include <fstream>
36#include <sstream>
37using namespace llvm;
38
39namespace {
40  struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
41    static char ID;
42
43    std::ostream *OS;
44    const std::string Banner;
45
46    Printer (std::ostream *os, const std::string &banner)
47      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
48
49    const char *getPassName() const { return "MachineFunction Printer"; }
50
51    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
52      AU.setPreservesAll();
53      MachineFunctionPass::getAnalysisUsage(AU);
54    }
55
56    bool runOnMachineFunction(MachineFunction &MF) {
57      (*OS) << Banner;
58      MF.print (*OS);
59      return false;
60    }
61  };
62  char Printer::ID = 0;
63}
64
65/// Returns a newly-created MachineFunction Printer pass. The default banner is
66/// empty.
67///
68FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
69                                                     const std::string &Banner){
70  return new Printer(OS, Banner);
71}
72
73//===---------------------------------------------------------------------===//
74// MachineFunction implementation
75//===---------------------------------------------------------------------===//
76
77void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
78  MBB->getParent()->DeleteMachineBasicBlock(MBB);
79}
80
81MachineFunction::MachineFunction(Function *F,
82                                 const TargetMachine &TM)
83  : Fn(F), Target(TM) {
84  if (TM.getRegisterInfo())
85    RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
86                  MachineRegisterInfo(*TM.getRegisterInfo());
87  else
88    RegInfo = 0;
89  MFInfo = 0;
90  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
91                  MachineFrameInfo(*TM.getFrameInfo());
92  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
93                     MachineConstantPool(TM.getTargetData());
94  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
95
96  // Set up jump table.
97  const TargetData &TD = *TM.getTargetData();
98  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
99  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
100  unsigned TyAlignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
101                               : TD.getPointerABIAlignment();
102  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
103                      MachineJumpTableInfo(EntrySize, TyAlignment);
104}
105
106MachineFunction::~MachineFunction() {
107  BasicBlocks.clear();
108  InstructionRecycler.clear(Allocator);
109  BasicBlockRecycler.clear(Allocator);
110  if (RegInfo) {
111    RegInfo->~MachineRegisterInfo();
112    Allocator.Deallocate(RegInfo);
113  }
114  if (MFInfo) {
115    MFInfo->~MachineFunctionInfo();
116    Allocator.Deallocate(MFInfo);
117  }
118  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
119  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
120  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
121}
122
123
124/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
125/// recomputes them.  This guarantees that the MBB numbers are sequential,
126/// dense, and match the ordering of the blocks within the function.  If a
127/// specific MachineBasicBlock is specified, only that block and those after
128/// it are renumbered.
129void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
130  if (empty()) { MBBNumbering.clear(); return; }
131  MachineFunction::iterator MBBI, E = end();
132  if (MBB == 0)
133    MBBI = begin();
134  else
135    MBBI = MBB;
136
137  // Figure out the block number this should have.
138  unsigned BlockNo = 0;
139  if (MBBI != begin())
140    BlockNo = prior(MBBI)->getNumber()+1;
141
142  for (; MBBI != E; ++MBBI, ++BlockNo) {
143    if (MBBI->getNumber() != (int)BlockNo) {
144      // Remove use of the old number.
145      if (MBBI->getNumber() != -1) {
146        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
147               "MBB number mismatch!");
148        MBBNumbering[MBBI->getNumber()] = 0;
149      }
150
151      // If BlockNo is already taken, set that block's number to -1.
152      if (MBBNumbering[BlockNo])
153        MBBNumbering[BlockNo]->setNumber(-1);
154
155      MBBNumbering[BlockNo] = MBBI;
156      MBBI->setNumber(BlockNo);
157    }
158  }
159
160  // Okay, all the blocks are renumbered.  If we have compactified the block
161  // numbering, shrink MBBNumbering now.
162  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
163  MBBNumbering.resize(BlockNo);
164}
165
166/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
167/// of `new MachineInstr'.
168///
169MachineInstr *
170MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
171                                    DebugLoc DL, bool NoImp) {
172  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
173    MachineInstr(TID, DL, NoImp);
174}
175
176/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
177/// 'Orig' instruction, identical in all ways except the the instruction
178/// has no parent, prev, or next.
179///
180MachineInstr *
181MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
182  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
183             MachineInstr(*this, *Orig);
184}
185
186/// DeleteMachineInstr - Delete the given MachineInstr.
187///
188void
189MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
190  // Clear the instructions memoperands. This must be done manually because
191  // the instruction's parent pointer is now null, so it can't properly
192  // deallocate them on its own.
193  MI->clearMemOperands(*this);
194
195  MI->~MachineInstr();
196  InstructionRecycler.Deallocate(Allocator, MI);
197}
198
199/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
200/// instead of `new MachineBasicBlock'.
201///
202MachineBasicBlock *
203MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
204  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
205             MachineBasicBlock(*this, bb);
206}
207
208/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
209///
210void
211MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
212  assert(MBB->getParent() == this && "MBB parent mismatch!");
213  MBB->~MachineBasicBlock();
214  BasicBlockRecycler.Deallocate(Allocator, MBB);
215}
216
217void MachineFunction::dump() const {
218  print(*cerr.stream());
219}
220
221void MachineFunction::print(std::ostream &OS) const {
222  OS << "# Machine code for " << Fn->getNameStr () << "():\n";
223
224  // Print Frame Information
225  FrameInfo->print(*this, OS);
226
227  // Print JumpTable Information
228  JumpTableInfo->print(OS);
229
230  // Print Constant Pool
231  {
232    raw_os_ostream OSS(OS);
233    ConstantPool->print(OSS);
234  }
235
236  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
237
238  if (RegInfo && !RegInfo->livein_empty()) {
239    OS << "Live Ins:";
240    for (MachineRegisterInfo::livein_iterator
241         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
242      if (TRI)
243        OS << " " << TRI->getName(I->first);
244      else
245        OS << " Reg #" << I->first;
246
247      if (I->second)
248        OS << " in VR#" << I->second << " ";
249    }
250    OS << "\n";
251  }
252  if (RegInfo && !RegInfo->liveout_empty()) {
253    OS << "Live Outs:";
254    for (MachineRegisterInfo::liveout_iterator
255         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
256      if (TRI)
257        OS << " " << TRI->getName(*I);
258      else
259        OS << " Reg #" << *I;
260    OS << "\n";
261  }
262
263  for (const_iterator BB = begin(); BB != end(); ++BB)
264    BB->print(OS);
265
266  OS << "\n# End machine code for " << Fn->getNameStr () << "().\n\n";
267}
268
269namespace llvm {
270  template<>
271  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
272    static std::string getGraphName(const MachineFunction *F) {
273      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
274    }
275
276    static std::string getNodeLabel(const MachineBasicBlock *Node,
277                                    const MachineFunction *Graph,
278                                    bool ShortNames) {
279      if (ShortNames && Node->getBasicBlock() &&
280          !Node->getBasicBlock()->getName().empty())
281        return Node->getBasicBlock()->getNameStr() + ":";
282
283      std::ostringstream Out;
284      if (ShortNames) {
285        Out << Node->getNumber() << ':';
286        return Out.str();
287      }
288
289      Node->print(Out);
290
291      std::string OutStr = Out.str();
292      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
293
294      // Process string output to make it nicer...
295      for (unsigned i = 0; i != OutStr.length(); ++i)
296        if (OutStr[i] == '\n') {                            // Left justify
297          OutStr[i] = '\\';
298          OutStr.insert(OutStr.begin()+i+1, 'l');
299        }
300      return OutStr;
301    }
302  };
303}
304
305void MachineFunction::viewCFG() const
306{
307#ifndef NDEBUG
308  ViewGraph(this, "mf" + getFunction()->getNameStr());
309#else
310  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
311       << "systems with Graphviz or gv!\n";
312#endif // NDEBUG
313}
314
315void MachineFunction::viewCFGOnly() const
316{
317#ifndef NDEBUG
318  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
319#else
320  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
321       << "systems with Graphviz or gv!\n";
322#endif // NDEBUG
323}
324
325/// addLiveIn - Add the specified physical register as a live-in value and
326/// create a corresponding virtual register for it.
327unsigned MachineFunction::addLiveIn(unsigned PReg,
328                                    const TargetRegisterClass *RC) {
329  assert(RC->contains(PReg) && "Not the correct regclass!");
330  unsigned VReg = getRegInfo().createVirtualRegister(RC);
331  getRegInfo().addLiveIn(PReg, VReg);
332  return VReg;
333}
334
335/// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given
336/// source file, line, and column. If none currently exists, create a new
337/// DebugLocTuple, and insert it into the DebugIdMap.
338unsigned MachineFunction::getOrCreateDebugLocID(GlobalVariable *CompileUnit,
339                                                unsigned Line, unsigned Col) {
340  DebugLocTuple Tuple(CompileUnit, Line, Col);
341  DenseMap<DebugLocTuple, unsigned>::iterator II
342    = DebugLocInfo.DebugIdMap.find(Tuple);
343  if (II != DebugLocInfo.DebugIdMap.end())
344    return II->second;
345  // Add a new tuple.
346  unsigned Id = DebugLocInfo.DebugLocations.size();
347  DebugLocInfo.DebugLocations.push_back(Tuple);
348  DebugLocInfo.DebugIdMap[Tuple] = Id;
349  return Id;
350}
351
352/// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object.
353DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const {
354  unsigned Idx = DL.getIndex();
355  assert(Idx < DebugLocInfo.DebugLocations.size() &&
356         "Invalid index into debug locations!");
357  return DebugLocInfo.DebugLocations[Idx];
358}
359
360//===----------------------------------------------------------------------===//
361//  MachineFrameInfo implementation
362//===----------------------------------------------------------------------===//
363
364/// CreateFixedObject - Create a new object at a fixed location on the stack.
365/// All fixed objects should be created before other objects are created for
366/// efficiency. By default, fixed objects are immutable. This returns an
367/// index with a negative value.
368///
369int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
370                                        bool Immutable) {
371  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
372  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
373  return -++NumFixedObjects;
374}
375
376
377void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
378  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
379  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
380
381  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
382    const StackObject &SO = Objects[i];
383    OS << "  <fi#" << (int)(i-NumFixedObjects) << ">: ";
384    if (SO.Size == ~0ULL) {
385      OS << "dead\n";
386      continue;
387    }
388    if (SO.Size == 0)
389      OS << "variable sized";
390    else
391      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
392    OS << " alignment is " << SO.Alignment << " byte"
393       << (SO.Alignment != 1 ? "s," : ",");
394
395    if (i < NumFixedObjects)
396      OS << " fixed";
397    if (i < NumFixedObjects || SO.SPOffset != -1) {
398      int64_t Off = SO.SPOffset - ValOffset;
399      OS << " at location [SP";
400      if (Off > 0)
401        OS << "+" << Off;
402      else if (Off < 0)
403        OS << Off;
404      OS << "]";
405    }
406    OS << "\n";
407  }
408
409  if (HasVarSizedObjects)
410    OS << "  Stack frame contains variable sized objects\n";
411}
412
413void MachineFrameInfo::dump(const MachineFunction &MF) const {
414  print(MF, *cerr.stream());
415}
416
417
418//===----------------------------------------------------------------------===//
419//  MachineJumpTableInfo implementation
420//===----------------------------------------------------------------------===//
421
422/// getJumpTableIndex - Create a new jump table entry in the jump table info
423/// or return an existing one.
424///
425unsigned MachineJumpTableInfo::getJumpTableIndex(
426                               const std::vector<MachineBasicBlock*> &DestBBs) {
427  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
428  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
429    if (JumpTables[i].MBBs == DestBBs)
430      return i;
431
432  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
433  return JumpTables.size()-1;
434}
435
436/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
437/// the jump tables to branch to New instead.
438bool
439MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
440                                             MachineBasicBlock *New) {
441  assert(Old != New && "Not making a change?");
442  bool MadeChange = false;
443  for (size_t i = 0, e = JumpTables.size(); i != e; ++i) {
444    MachineJumpTableEntry &JTE = JumpTables[i];
445    for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
446      if (JTE.MBBs[j] == Old) {
447        JTE.MBBs[j] = New;
448        MadeChange = true;
449      }
450  }
451  return MadeChange;
452}
453
454void MachineJumpTableInfo::print(std::ostream &OS) const {
455  // FIXME: this is lame, maybe we could print out the MBB numbers or something
456  // like {1, 2, 4, 5, 3, 0}
457  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
458    OS << "  <jt#" << i << "> has " << JumpTables[i].MBBs.size()
459       << " entries\n";
460  }
461}
462
463void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
464
465
466//===----------------------------------------------------------------------===//
467//  MachineConstantPool implementation
468//===----------------------------------------------------------------------===//
469
470const Type *MachineConstantPoolEntry::getType() const {
471  if (isMachineConstantPoolEntry())
472    return Val.MachineCPVal->getType();
473  return Val.ConstVal->getType();
474}
475
476
477unsigned MachineConstantPoolEntry::getRelocationInfo() const {
478  if (isMachineConstantPoolEntry())
479    return Val.MachineCPVal->getRelocationInfo();
480  return Val.ConstVal->getRelocationInfo();
481}
482
483MachineConstantPool::~MachineConstantPool() {
484  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
485    if (Constants[i].isMachineConstantPoolEntry())
486      delete Constants[i].Val.MachineCPVal;
487}
488
489/// getConstantPoolIndex - Create a new entry in the constant pool or return
490/// an existing one.  User must specify the log2 of the minimum required
491/// alignment for the object.
492///
493unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
494                                                   unsigned Alignment) {
495  assert(Alignment && "Alignment must be specified!");
496  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
497
498  // Check to see if we already have this constant.
499  //
500  // FIXME, this could be made much more efficient for large constant pools.
501  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
502    if (Constants[i].Val.ConstVal == C &&
503        (Constants[i].getAlignment() & (Alignment - 1)) == 0)
504      return i;
505
506  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
507  return Constants.size()-1;
508}
509
510unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
511                                                   unsigned Alignment) {
512  assert(Alignment && "Alignment must be specified!");
513  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
514
515  // Check to see if we already have this constant.
516  //
517  // FIXME, this could be made much more efficient for large constant pools.
518  int Idx = V->getExistingMachineCPValue(this, Alignment);
519  if (Idx != -1)
520    return (unsigned)Idx;
521
522  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
523  return Constants.size()-1;
524}
525
526void MachineConstantPool::print(raw_ostream &OS) const {
527  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
528    OS << "  <cp#" << i << "> is";
529    if (Constants[i].isMachineConstantPoolEntry())
530      Constants[i].Val.MachineCPVal->print(OS);
531    else
532      OS << *(Value*)Constants[i].Val.ConstVal;
533    OS << " , alignment=" << Constants[i].getAlignment();
534    OS << "\n";
535  }
536}
537
538void MachineConstantPool::dump() const { print(errs()); }
539