MachineFunction.cpp revision 9bc96a57206cbebaa9b0ba9979f949eb10c1592c 
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/CodeGen/MachineConstantPool.h"
18#include "llvm/CodeGen/MachineFunctionPass.h"
19#include "llvm/CodeGen/MachineFrameInfo.h"
20#include "llvm/CodeGen/MachineInstr.h"
21#include "llvm/CodeGen/MachineJumpTableInfo.h"
22#include "llvm/CodeGen/MachineRegisterInfo.h"
23#include "llvm/CodeGen/Passes.h"
24#include "llvm/Target/TargetData.h"
25#include "llvm/Target/TargetMachine.h"
26#include "llvm/Target/TargetFrameInfo.h"
27#include "llvm/Function.h"
28#include "llvm/Instructions.h"
29#include "llvm/Support/Compiler.h"
30#include "llvm/Support/GraphWriter.h"
31#include "llvm/Support/raw_ostream.h"
32#include "llvm/ADT/STLExtras.h"
33#include "llvm/Config/config.h"
34#include <fstream>
35#include <sstream>
36using namespace llvm;
37
38static AnnotationID MF_AID(
39  AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
40
41// Out of line virtual function to home classes.
42void MachineFunctionPass::virtfn() {}
43
44namespace {
45  struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
46    static char ID;
47
48    std::ostream *OS;
49    const std::string Banner;
50
51    Printer (std::ostream *os, const std::string &banner)
52      : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
53
54    const char *getPassName() const { return "MachineFunction Printer"; }
55
56    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
57      AU.setPreservesAll();
58    }
59
60    bool runOnMachineFunction(MachineFunction &MF) {
61      (*OS) << Banner;
62      MF.print (*OS);
63      return false;
64    }
65  };
66  char Printer::ID = 0;
67}
68
69/// Returns a newly-created MachineFunction Printer pass. The default output
70/// stream is std::cerr; the default banner is empty.
71///
72FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
73                                                     const std::string &Banner){
74  return new Printer(OS, Banner);
75}
76
77namespace {
78  struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
79    static char ID;
80    Deleter() : MachineFunctionPass(&ID) {}
81
82    const char *getPassName() const { return "Machine Code Deleter"; }
83
84    bool runOnMachineFunction(MachineFunction &MF) {
85      // Delete the annotation from the function now.
86      MachineFunction::destruct(MF.getFunction());
87      return true;
88    }
89  };
90  char Deleter::ID = 0;
91}
92
93/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
94/// the current function, which should happen after the function has been
95/// emitted to a .s file or to memory.
96FunctionPass *llvm::createMachineCodeDeleter() {
97  return new Deleter();
98}
99
100
101
102//===---------------------------------------------------------------------===//
103// MachineFunction implementation
104//===---------------------------------------------------------------------===//
105
106void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
107  MBB->getParent()->DeleteMachineBasicBlock(MBB);
108}
109
110MachineFunction::MachineFunction(const Function *F,
111                                 const TargetMachine &TM)
112  : Annotation(MF_AID), Fn(F), Target(TM) {
113  if (TM.getRegisterInfo())
114    RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
115                  MachineRegisterInfo(*TM.getRegisterInfo());
116  else
117    RegInfo = 0;
118  MFInfo = 0;
119  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
120                  MachineFrameInfo(*TM.getFrameInfo());
121  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
122                     MachineConstantPool(TM.getTargetData());
123
124  // Set up jump table.
125  const TargetData &TD = *TM.getTargetData();
126  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
127  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
128  unsigned Alignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
129                             : TD.getPointerABIAlignment();
130  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
131                      MachineJumpTableInfo(EntrySize, Alignment);
132}
133
134MachineFunction::~MachineFunction() {
135  BasicBlocks.clear();
136  InstructionRecycler.clear(Allocator);
137  BasicBlockRecycler.clear(Allocator);
138  if (RegInfo)
139    RegInfo->~MachineRegisterInfo();        Allocator.Deallocate(RegInfo);
140  if (MFInfo) {
141    MFInfo->~MachineFunctionInfo();       Allocator.Deallocate(MFInfo);
142  }
143  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
144  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
145  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
146}
147
148
149/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
150/// recomputes them.  This guarantees that the MBB numbers are sequential,
151/// dense, and match the ordering of the blocks within the function.  If a
152/// specific MachineBasicBlock is specified, only that block and those after
153/// it are renumbered.
154void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
155  if (empty()) { MBBNumbering.clear(); return; }
156  MachineFunction::iterator MBBI, E = end();
157  if (MBB == 0)
158    MBBI = begin();
159  else
160    MBBI = MBB;
161
162  // Figure out the block number this should have.
163  unsigned BlockNo = 0;
164  if (MBBI != begin())
165    BlockNo = prior(MBBI)->getNumber()+1;
166
167  for (; MBBI != E; ++MBBI, ++BlockNo) {
168    if (MBBI->getNumber() != (int)BlockNo) {
169      // Remove use of the old number.
170      if (MBBI->getNumber() != -1) {
171        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
172               "MBB number mismatch!");
173        MBBNumbering[MBBI->getNumber()] = 0;
174      }
175
176      // If BlockNo is already taken, set that block's number to -1.
177      if (MBBNumbering[BlockNo])
178        MBBNumbering[BlockNo]->setNumber(-1);
179
180      MBBNumbering[BlockNo] = MBBI;
181      MBBI->setNumber(BlockNo);
182    }
183  }
184
185  // Okay, all the blocks are renumbered.  If we have compactified the block
186  // numbering, shrink MBBNumbering now.
187  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
188  MBBNumbering.resize(BlockNo);
189}
190
191/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
192/// of `new MachineInstr'.
193///
194MachineInstr *
195MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
196                                    DebugLoc DL, bool NoImp) {
197  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
198    MachineInstr(TID, DL, NoImp);
199}
200
201/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
202/// 'Orig' instruction, identical in all ways except the the instruction
203/// has no parent, prev, or next.
204///
205MachineInstr *
206MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
207  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
208             MachineInstr(*this, *Orig);
209}
210
211/// DeleteMachineInstr - Delete the given MachineInstr.
212///
213void
214MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
215  // Clear the instructions memoperands. This must be done manually because
216  // the instruction's parent pointer is now null, so it can't properly
217  // deallocate them on its own.
218  MI->clearMemOperands(*this);
219
220  MI->~MachineInstr();
221  InstructionRecycler.Deallocate(Allocator, MI);
222}
223
224/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
225/// instead of `new MachineBasicBlock'.
226///
227MachineBasicBlock *
228MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
229  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
230             MachineBasicBlock(*this, bb);
231}
232
233/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
234///
235void
236MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
237  assert(MBB->getParent() == this && "MBB parent mismatch!");
238  MBB->~MachineBasicBlock();
239  BasicBlockRecycler.Deallocate(Allocator, MBB);
240}
241
242void MachineFunction::dump() const {
243  print(*cerr.stream());
244}
245
246void MachineFunction::print(std::ostream &OS) const {
247  OS << "# Machine code for " << Fn->getName () << "():\n";
248
249  // Print Frame Information
250  FrameInfo->print(*this, OS);
251
252  // Print JumpTable Information
253  JumpTableInfo->print(OS);
254
255  // Print Constant Pool
256  {
257    raw_os_ostream OSS(OS);
258    ConstantPool->print(OSS);
259  }
260
261  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
262
263  if (RegInfo && !RegInfo->livein_empty()) {
264    OS << "Live Ins:";
265    for (MachineRegisterInfo::livein_iterator
266         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
267      if (TRI)
268        OS << " " << TRI->getName(I->first);
269      else
270        OS << " Reg #" << I->first;
271
272      if (I->second)
273        OS << " in VR#" << I->second << " ";
274    }
275    OS << "\n";
276  }
277  if (RegInfo && !RegInfo->liveout_empty()) {
278    OS << "Live Outs:";
279    for (MachineRegisterInfo::liveout_iterator
280         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
281      if (TRI)
282        OS << " " << TRI->getName(*I);
283      else
284        OS << " Reg #" << *I;
285    OS << "\n";
286  }
287
288  for (const_iterator BB = begin(); BB != end(); ++BB)
289    BB->print(OS);
290
291  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
292}
293
294/// CFGOnly flag - This is used to control whether or not the CFG graph printer
295/// prints out the contents of basic blocks or not.  This is acceptable because
296/// this code is only really used for debugging purposes.
297///
298static bool CFGOnly = false;
299
300namespace llvm {
301  template<>
302  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
303    static std::string getGraphName(const MachineFunction *F) {
304      return "CFG for '" + F->getFunction()->getName() + "' function";
305    }
306
307    static std::string getNodeLabel(const MachineBasicBlock *Node,
308                                    const MachineFunction *Graph) {
309      if (CFGOnly && Node->getBasicBlock() &&
310          !Node->getBasicBlock()->getName().empty())
311        return Node->getBasicBlock()->getName() + ":";
312
313      std::ostringstream Out;
314      if (CFGOnly) {
315        Out << Node->getNumber() << ':';
316        return Out.str();
317      }
318
319      Node->print(Out);
320
321      std::string OutStr = Out.str();
322      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
323
324      // Process string output to make it nicer...
325      for (unsigned i = 0; i != OutStr.length(); ++i)
326        if (OutStr[i] == '\n') {                            // Left justify
327          OutStr[i] = '\\';
328          OutStr.insert(OutStr.begin()+i+1, 'l');
329        }
330      return OutStr;
331    }
332  };
333}
334
335void MachineFunction::viewCFG() const
336{
337#ifndef NDEBUG
338  ViewGraph(this, "mf" + getFunction()->getName());
339#else
340  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
341       << "systems with Graphviz or gv!\n";
342#endif // NDEBUG
343}
344
345void MachineFunction::viewCFGOnly() const
346{
347  CFGOnly = true;
348  viewCFG();
349  CFGOnly = false;
350}
351
352// The next two methods are used to construct and to retrieve
353// the MachineCodeForFunction object for the given function.
354// construct() -- Allocates and initializes for a given function and target
355// get()       -- Returns a handle to the object.
356//                This should not be called before "construct()"
357//                for a given Function.
358//
359MachineFunction&
360MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
361{
362  assert(Fn->getAnnotation(MF_AID) == 0 &&
363         "Object already exists for this function!");
364  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
365  Fn->addAnnotation(mcInfo);
366  return *mcInfo;
367}
368
369void MachineFunction::destruct(const Function *Fn) {
370  bool Deleted = Fn->deleteAnnotation(MF_AID);
371  assert(Deleted && "Machine code did not exist for function!");
372  Deleted = Deleted; // silence warning when no assertions.
373}
374
375MachineFunction& MachineFunction::get(const Function *F)
376{
377  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
378  assert(mc && "Call construct() method first to allocate the object");
379  return *mc;
380}
381
382/// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given
383/// source file, line, and column. If none currently exists, create add a new
384/// new DebugLocTuple and insert it into the DebugIdMap.
385unsigned MachineFunction::getOrCreateDebugLocID(unsigned Src, unsigned Line,
386                                                unsigned Col) {
387  struct DebugLocTuple Tuple(Src, Line, Col);
388  DenseMap<DebugLocTuple, unsigned>::iterator II
389    = DebugLocInfo.DebugIdMap.find(Tuple);
390  if (II != DebugLocInfo.DebugIdMap.end())
391    return II->second;
392  // Add a new tuple.
393  unsigned Id = DebugLocInfo.DebugLocations.size();
394  DebugLocInfo.DebugLocations.push_back(Tuple);
395  DebugLocInfo.DebugIdMap[Tuple] = Id;
396  return Id;
397}
398
399//===----------------------------------------------------------------------===//
400//  MachineFrameInfo implementation
401//===----------------------------------------------------------------------===//
402
403/// CreateFixedObject - Create a new object at a fixed location on the stack.
404/// All fixed objects should be created before other objects are created for
405/// efficiency. By default, fixed objects are immutable. This returns an
406/// index with a negative value.
407///
408int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
409                                        bool Immutable) {
410  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
411  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
412  return -++NumFixedObjects;
413}
414
415
416void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
417  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
418  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
419
420  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
421    const StackObject &SO = Objects[i];
422    OS << "  <fi#" << (int)(i-NumFixedObjects) << ">: ";
423    if (SO.Size == ~0ULL) {
424      OS << "dead\n";
425      continue;
426    }
427    if (SO.Size == 0)
428      OS << "variable sized";
429    else
430      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
431    OS << " alignment is " << SO.Alignment << " byte"
432       << (SO.Alignment != 1 ? "s," : ",");
433
434    if (i < NumFixedObjects)
435      OS << " fixed";
436    if (i < NumFixedObjects || SO.SPOffset != -1) {
437      int64_t Off = SO.SPOffset - ValOffset;
438      OS << " at location [SP";
439      if (Off > 0)
440        OS << "+" << Off;
441      else if (Off < 0)
442        OS << Off;
443      OS << "]";
444    }
445    OS << "\n";
446  }
447
448  if (HasVarSizedObjects)
449    OS << "  Stack frame contains variable sized objects\n";
450}
451
452void MachineFrameInfo::dump(const MachineFunction &MF) const {
453  print(MF, *cerr.stream());
454}
455
456
457//===----------------------------------------------------------------------===//
458//  MachineJumpTableInfo implementation
459//===----------------------------------------------------------------------===//
460
461/// getJumpTableIndex - Create a new jump table entry in the jump table info
462/// or return an existing one.
463///
464unsigned MachineJumpTableInfo::getJumpTableIndex(
465                               const std::vector<MachineBasicBlock*> &DestBBs) {
466  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
467  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
468    if (JumpTables[i].MBBs == DestBBs)
469      return i;
470
471  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
472  return JumpTables.size()-1;
473}
474
475
476void MachineJumpTableInfo::print(std::ostream &OS) const {
477  // FIXME: this is lame, maybe we could print out the MBB numbers or something
478  // like {1, 2, 4, 5, 3, 0}
479  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
480    OS << "  <jt#" << i << "> has " << JumpTables[i].MBBs.size()
481       << " entries\n";
482  }
483}
484
485void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
486
487
488//===----------------------------------------------------------------------===//
489//  MachineConstantPool implementation
490//===----------------------------------------------------------------------===//
491
492const Type *MachineConstantPoolEntry::getType() const {
493  if (isMachineConstantPoolEntry())
494      return Val.MachineCPVal->getType();
495  return Val.ConstVal->getType();
496}
497
498MachineConstantPool::~MachineConstantPool() {
499  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
500    if (Constants[i].isMachineConstantPoolEntry())
501      delete Constants[i].Val.MachineCPVal;
502}
503
504/// getConstantPoolIndex - Create a new entry in the constant pool or return
505/// an existing one.  User must specify the log2 of the minimum required
506/// alignment for the object.
507///
508unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
509                                                   unsigned Alignment) {
510  assert(Alignment && "Alignment must be specified!");
511  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
512
513  // Check to see if we already have this constant.
514  //
515  // FIXME, this could be made much more efficient for large constant pools.
516  unsigned AlignMask = (1 << Alignment)-1;
517  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
518    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
519      return i;
520
521  unsigned Offset = 0;
522  if (!Constants.empty()) {
523    Offset = Constants.back().getOffset();
524    Offset += TD->getTypePaddedSize(Constants.back().getType());
525    Offset = (Offset+AlignMask)&~AlignMask;
526  }
527
528  Constants.push_back(MachineConstantPoolEntry(C, Offset));
529  return Constants.size()-1;
530}
531
532unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
533                                                   unsigned Alignment) {
534  assert(Alignment && "Alignment must be specified!");
535  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
536
537  // Check to see if we already have this constant.
538  //
539  // FIXME, this could be made much more efficient for large constant pools.
540  unsigned AlignMask = (1 << Alignment)-1;
541  int Idx = V->getExistingMachineCPValue(this, Alignment);
542  if (Idx != -1)
543    return (unsigned)Idx;
544
545  unsigned Offset = 0;
546  if (!Constants.empty()) {
547    Offset = Constants.back().getOffset();
548    Offset += TD->getTypePaddedSize(Constants.back().getType());
549    Offset = (Offset+AlignMask)&~AlignMask;
550  }
551
552  Constants.push_back(MachineConstantPoolEntry(V, Offset));
553  return Constants.size()-1;
554}
555
556void MachineConstantPool::print(raw_ostream &OS) const {
557  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
558    OS << "  <cp#" << i << "> is";
559    if (Constants[i].isMachineConstantPoolEntry())
560      Constants[i].Val.MachineCPVal->print(OS);
561    else
562      OS << *(Value*)Constants[i].Val.ConstVal;
563    OS << " , offset=" << Constants[i].getOffset();
564    OS << "\n";
565  }
566}
567
568void MachineConstantPool::dump() const { print(errs()); errs().flush(); }
569