MachineFunction.cpp revision ad2afc2a421a0e41603d5eee412d4d8c77e9bc1c 
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 output
66/// stream is std::cerr; the default banner is 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  : Annotation(AnnotationManager::getID("CodeGen::MachineCodeForFunction")),
84    Fn(F), Target(TM) {
85  if (TM.getRegisterInfo())
86    RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
87                  MachineRegisterInfo(*TM.getRegisterInfo());
88  else
89    RegInfo = 0;
90  MFInfo = 0;
91  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
92                  MachineFrameInfo(*TM.getFrameInfo());
93  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
94                     MachineConstantPool(TM.getTargetData());
95  Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
96
97  // Set up jump table.
98  const TargetData &TD = *TM.getTargetData();
99  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
100  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
101  unsigned TyAlignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
102                               : TD.getPointerABIAlignment();
103  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
104                      MachineJumpTableInfo(EntrySize, TyAlignment);
105}
106
107MachineFunction::~MachineFunction() {
108  BasicBlocks.clear();
109  InstructionRecycler.clear(Allocator);
110  BasicBlockRecycler.clear(Allocator);
111  if (RegInfo) {
112    RegInfo->~MachineRegisterInfo();
113    Allocator.Deallocate(RegInfo);
114  }
115  if (MFInfo) {
116    MFInfo->~MachineFunctionInfo();
117    Allocator.Deallocate(MFInfo);
118  }
119  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
120  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
121  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
122}
123
124
125/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
126/// recomputes them.  This guarantees that the MBB numbers are sequential,
127/// dense, and match the ordering of the blocks within the function.  If a
128/// specific MachineBasicBlock is specified, only that block and those after
129/// it are renumbered.
130void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
131  if (empty()) { MBBNumbering.clear(); return; }
132  MachineFunction::iterator MBBI, E = end();
133  if (MBB == 0)
134    MBBI = begin();
135  else
136    MBBI = MBB;
137
138  // Figure out the block number this should have.
139  unsigned BlockNo = 0;
140  if (MBBI != begin())
141    BlockNo = prior(MBBI)->getNumber()+1;
142
143  for (; MBBI != E; ++MBBI, ++BlockNo) {
144    if (MBBI->getNumber() != (int)BlockNo) {
145      // Remove use of the old number.
146      if (MBBI->getNumber() != -1) {
147        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
148               "MBB number mismatch!");
149        MBBNumbering[MBBI->getNumber()] = 0;
150      }
151
152      // If BlockNo is already taken, set that block's number to -1.
153      if (MBBNumbering[BlockNo])
154        MBBNumbering[BlockNo]->setNumber(-1);
155
156      MBBNumbering[BlockNo] = MBBI;
157      MBBI->setNumber(BlockNo);
158    }
159  }
160
161  // Okay, all the blocks are renumbered.  If we have compactified the block
162  // numbering, shrink MBBNumbering now.
163  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
164  MBBNumbering.resize(BlockNo);
165}
166
167/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
168/// of `new MachineInstr'.
169///
170MachineInstr *
171MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
172                                    DebugLoc DL, bool NoImp) {
173  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
174    MachineInstr(TID, DL, NoImp);
175}
176
177/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
178/// 'Orig' instruction, identical in all ways except the the instruction
179/// has no parent, prev, or next.
180///
181MachineInstr *
182MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
183  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
184             MachineInstr(*this, *Orig);
185}
186
187/// DeleteMachineInstr - Delete the given MachineInstr.
188///
189void
190MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
191  // Clear the instructions memoperands. This must be done manually because
192  // the instruction's parent pointer is now null, so it can't properly
193  // deallocate them on its own.
194  MI->clearMemOperands(*this);
195
196  MI->~MachineInstr();
197  InstructionRecycler.Deallocate(Allocator, MI);
198}
199
200/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
201/// instead of `new MachineBasicBlock'.
202///
203MachineBasicBlock *
204MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
205  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
206             MachineBasicBlock(*this, bb);
207}
208
209/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
210///
211void
212MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
213  assert(MBB->getParent() == this && "MBB parent mismatch!");
214  MBB->~MachineBasicBlock();
215  BasicBlockRecycler.Deallocate(Allocator, MBB);
216}
217
218void MachineFunction::dump() const {
219  print(*cerr.stream());
220}
221
222void MachineFunction::print(std::ostream &OS) const {
223  OS << "# Machine code for " << Fn->getNameStr () << "():\n";
224
225  // Print Frame Information
226  FrameInfo->print(*this, OS);
227
228  // Print JumpTable Information
229  JumpTableInfo->print(OS);
230
231  // Print Constant Pool
232  {
233    raw_os_ostream OSS(OS);
234    ConstantPool->print(OSS);
235  }
236
237  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
238
239  if (RegInfo && !RegInfo->livein_empty()) {
240    OS << "Live Ins:";
241    for (MachineRegisterInfo::livein_iterator
242         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
243      if (TRI)
244        OS << " " << TRI->getName(I->first);
245      else
246        OS << " Reg #" << I->first;
247
248      if (I->second)
249        OS << " in VR#" << I->second << " ";
250    }
251    OS << "\n";
252  }
253  if (RegInfo && !RegInfo->liveout_empty()) {
254    OS << "Live Outs:";
255    for (MachineRegisterInfo::liveout_iterator
256         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
257      if (TRI)
258        OS << " " << TRI->getName(*I);
259      else
260        OS << " Reg #" << *I;
261    OS << "\n";
262  }
263
264  for (const_iterator BB = begin(); BB != end(); ++BB)
265    BB->print(OS);
266
267  OS << "\n# End machine code for " << Fn->getNameStr () << "().\n\n";
268}
269
270namespace llvm {
271  template<>
272  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
273    static std::string getGraphName(const MachineFunction *F) {
274      return "CFG for '" + F->getFunction()->getNameStr() + "' function";
275    }
276
277    static std::string getNodeLabel(const MachineBasicBlock *Node,
278                                    const MachineFunction *Graph,
279                                    bool ShortNames) {
280      if (ShortNames && Node->getBasicBlock() &&
281          !Node->getBasicBlock()->getName().empty())
282        return Node->getBasicBlock()->getNameStr() + ":";
283
284      std::ostringstream Out;
285      if (ShortNames) {
286        Out << Node->getNumber() << ':';
287        return Out.str();
288      }
289
290      Node->print(Out);
291
292      std::string OutStr = Out.str();
293      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
294
295      // Process string output to make it nicer...
296      for (unsigned i = 0; i != OutStr.length(); ++i)
297        if (OutStr[i] == '\n') {                            // Left justify
298          OutStr[i] = '\\';
299          OutStr.insert(OutStr.begin()+i+1, 'l');
300        }
301      return OutStr;
302    }
303  };
304}
305
306void MachineFunction::viewCFG() const
307{
308#ifndef NDEBUG
309  ViewGraph(this, "mf" + getFunction()->getNameStr());
310#else
311  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
312       << "systems with Graphviz or gv!\n";
313#endif // NDEBUG
314}
315
316void MachineFunction::viewCFGOnly() const
317{
318#ifndef NDEBUG
319  ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
320#else
321  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
322       << "systems with Graphviz or gv!\n";
323#endif // NDEBUG
324}
325
326/// addLiveIn - Add the specified physical register as a live-in value and
327/// create a corresponding virtual register for it.
328unsigned MachineFunction::addLiveIn(unsigned PReg,
329                                    const TargetRegisterClass *RC) {
330  assert(RC->contains(PReg) && "Not the correct regclass!");
331  unsigned VReg = getRegInfo().createVirtualRegister(RC);
332  getRegInfo().addLiveIn(PReg, VReg);
333  return VReg;
334}
335
336/// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given
337/// source file, line, and column. If none currently exists, create a new
338/// DebugLocTuple, and insert it into the DebugIdMap.
339unsigned MachineFunction::getOrCreateDebugLocID(GlobalVariable *CompileUnit,
340                                                unsigned Line, unsigned Col) {
341  DebugLocTuple Tuple(CompileUnit, Line, Col);
342  DenseMap<DebugLocTuple, unsigned>::iterator II
343    = DebugLocInfo.DebugIdMap.find(Tuple);
344  if (II != DebugLocInfo.DebugIdMap.end())
345    return II->second;
346  // Add a new tuple.
347  unsigned Id = DebugLocInfo.DebugLocations.size();
348  DebugLocInfo.DebugLocations.push_back(Tuple);
349  DebugLocInfo.DebugIdMap[Tuple] = Id;
350  return Id;
351}
352
353/// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object.
354DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const {
355  unsigned Idx = DL.getIndex();
356  assert(Idx < DebugLocInfo.DebugLocations.size() &&
357         "Invalid index into debug locations!");
358  return DebugLocInfo.DebugLocations[Idx];
359}
360
361//===----------------------------------------------------------------------===//
362//  MachineFrameInfo implementation
363//===----------------------------------------------------------------------===//
364
365/// CreateFixedObject - Create a new object at a fixed location on the stack.
366/// All fixed objects should be created before other objects are created for
367/// efficiency. By default, fixed objects are immutable. This returns an
368/// index with a negative value.
369///
370int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
371                                        bool Immutable) {
372  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
373  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
374  return -++NumFixedObjects;
375}
376
377
378void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
379  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
380  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
381
382  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
383    const StackObject &SO = Objects[i];
384    OS << "  <fi#" << (int)(i-NumFixedObjects) << ">: ";
385    if (SO.Size == ~0ULL) {
386      OS << "dead\n";
387      continue;
388    }
389    if (SO.Size == 0)
390      OS << "variable sized";
391    else
392      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
393    OS << " alignment is " << SO.Alignment << " byte"
394       << (SO.Alignment != 1 ? "s," : ",");
395
396    if (i < NumFixedObjects)
397      OS << " fixed";
398    if (i < NumFixedObjects || SO.SPOffset != -1) {
399      int64_t Off = SO.SPOffset - ValOffset;
400      OS << " at location [SP";
401      if (Off > 0)
402        OS << "+" << Off;
403      else if (Off < 0)
404        OS << Off;
405      OS << "]";
406    }
407    OS << "\n";
408  }
409
410  if (HasVarSizedObjects)
411    OS << "  Stack frame contains variable sized objects\n";
412}
413
414void MachineFrameInfo::dump(const MachineFunction &MF) const {
415  print(MF, *cerr.stream());
416}
417
418
419//===----------------------------------------------------------------------===//
420//  MachineJumpTableInfo implementation
421//===----------------------------------------------------------------------===//
422
423/// getJumpTableIndex - Create a new jump table entry in the jump table info
424/// or return an existing one.
425///
426unsigned MachineJumpTableInfo::getJumpTableIndex(
427                               const std::vector<MachineBasicBlock*> &DestBBs) {
428  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
429  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
430    if (JumpTables[i].MBBs == DestBBs)
431      return i;
432
433  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
434  return JumpTables.size()-1;
435}
436
437/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
438/// the jump tables to branch to New instead.
439bool
440MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
441                                             MachineBasicBlock *New) {
442  assert(Old != New && "Not making a change?");
443  bool MadeChange = false;
444  for (size_t i = 0, e = JumpTables.size(); i != e; ++i) {
445    MachineJumpTableEntry &JTE = JumpTables[i];
446    for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
447      if (JTE.MBBs[j] == Old) {
448        JTE.MBBs[j] = New;
449        MadeChange = true;
450      }
451  }
452  return MadeChange;
453}
454
455void MachineJumpTableInfo::print(std::ostream &OS) const {
456  // FIXME: this is lame, maybe we could print out the MBB numbers or something
457  // like {1, 2, 4, 5, 3, 0}
458  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
459    OS << "  <jt#" << i << "> has " << JumpTables[i].MBBs.size()
460       << " entries\n";
461  }
462}
463
464void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
465
466
467//===----------------------------------------------------------------------===//
468//  MachineConstantPool implementation
469//===----------------------------------------------------------------------===//
470
471const Type *MachineConstantPoolEntry::getType() const {
472  if (isMachineConstantPoolEntry())
473    return Val.MachineCPVal->getType();
474  return Val.ConstVal->getType();
475}
476
477
478unsigned MachineConstantPoolEntry::getRelocationInfo() const {
479  if (isMachineConstantPoolEntry())
480    return Val.MachineCPVal->getRelocationInfo();
481  return Val.ConstVal->getRelocationInfo();
482}
483
484MachineConstantPool::~MachineConstantPool() {
485  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
486    if (Constants[i].isMachineConstantPoolEntry())
487      delete Constants[i].Val.MachineCPVal;
488}
489
490/// getConstantPoolIndex - Create a new entry in the constant pool or return
491/// an existing one.  User must specify the log2 of the minimum required
492/// alignment for the object.
493///
494unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
495                                                   unsigned Alignment) {
496  assert(Alignment && "Alignment must be specified!");
497  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
498
499  // Check to see if we already have this constant.
500  //
501  // FIXME, this could be made much more efficient for large constant pools.
502  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
503    if (Constants[i].Val.ConstVal == C &&
504        (Constants[i].getAlignment() & (Alignment - 1)) == 0)
505      return i;
506
507  Constants.push_back(MachineConstantPoolEntry(C, Alignment));
508  return Constants.size()-1;
509}
510
511unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
512                                                   unsigned Alignment) {
513  assert(Alignment && "Alignment must be specified!");
514  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
515
516  // Check to see if we already have this constant.
517  //
518  // FIXME, this could be made much more efficient for large constant pools.
519  int Idx = V->getExistingMachineCPValue(this, Alignment);
520  if (Idx != -1)
521    return (unsigned)Idx;
522
523  Constants.push_back(MachineConstantPoolEntry(V, Alignment));
524  return Constants.size()-1;
525}
526
527void MachineConstantPool::print(raw_ostream &OS) const {
528  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
529    OS << "  <cp#" << i << "> is";
530    if (Constants[i].isMachineConstantPoolEntry())
531      Constants[i].Val.MachineCPVal->print(OS);
532    else
533      OS << *(Value*)Constants[i].Val.ConstVal;
534    OS << " , alignment=" << Constants[i].getAlignment();
535    OS << "\n";
536  }
537}
538
539void MachineConstantPool::dump() const { print(errs()); }
540