MachineFunction.cpp revision c4b1abd81e4de314880110c5d58917d4747fb978 
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, bool NoImp) {
196  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
197             MachineInstr(TID, NoImp);
198}
199
200/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
201/// 'Orig' instruction, identical in all ways except the the instruction
202/// has no parent, prev, or next.
203///
204MachineInstr *
205MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
206  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
207             MachineInstr(*this, *Orig);
208}
209
210/// DeleteMachineInstr - Delete the given MachineInstr.
211///
212void
213MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
214  // Clear the instructions memoperands. This must be done manually because
215  // the instruction's parent pointer is now null, so it can't properly
216  // deallocate them on its own.
217  MI->clearMemOperands(*this);
218
219  MI->~MachineInstr();
220  InstructionRecycler.Deallocate(Allocator, MI);
221}
222
223/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
224/// instead of `new MachineBasicBlock'.
225///
226MachineBasicBlock *
227MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
228  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
229             MachineBasicBlock(*this, bb);
230}
231
232/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
233///
234void
235MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
236  assert(MBB->getParent() == this && "MBB parent mismatch!");
237  MBB->~MachineBasicBlock();
238  BasicBlockRecycler.Deallocate(Allocator, MBB);
239}
240
241void MachineFunction::dump() const {
242  print(*cerr.stream());
243}
244
245void MachineFunction::print(std::ostream &OS) const {
246  OS << "# Machine code for " << Fn->getName () << "():\n";
247
248  // Print Frame Information
249  FrameInfo->print(*this, OS);
250
251  // Print JumpTable Information
252  JumpTableInfo->print(OS);
253
254  // Print Constant Pool
255  {
256    raw_os_ostream OSS(OS);
257    ConstantPool->print(OSS);
258  }
259
260  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
261
262  if (RegInfo && !RegInfo->livein_empty()) {
263    OS << "Live Ins:";
264    for (MachineRegisterInfo::livein_iterator
265         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
266      if (TRI)
267        OS << " " << TRI->getName(I->first);
268      else
269        OS << " Reg #" << I->first;
270
271      if (I->second)
272        OS << " in VR#" << I->second << " ";
273    }
274    OS << "\n";
275  }
276  if (RegInfo && !RegInfo->liveout_empty()) {
277    OS << "Live Outs:";
278    for (MachineRegisterInfo::liveout_iterator
279         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
280      if (TRI)
281        OS << " " << TRI->getName(*I);
282      else
283        OS << " Reg #" << *I;
284    OS << "\n";
285  }
286
287  for (const_iterator BB = begin(); BB != end(); ++BB)
288    BB->print(OS);
289
290  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
291}
292
293/// CFGOnly flag - This is used to control whether or not the CFG graph printer
294/// prints out the contents of basic blocks or not.  This is acceptable because
295/// this code is only really used for debugging purposes.
296///
297static bool CFGOnly = false;
298
299namespace llvm {
300  template<>
301  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
302    static std::string getGraphName(const MachineFunction *F) {
303      return "CFG for '" + F->getFunction()->getName() + "' function";
304    }
305
306    static std::string getNodeLabel(const MachineBasicBlock *Node,
307                                    const MachineFunction *Graph) {
308      if (CFGOnly && Node->getBasicBlock() &&
309          !Node->getBasicBlock()->getName().empty())
310        return Node->getBasicBlock()->getName() + ":";
311
312      std::ostringstream Out;
313      if (CFGOnly) {
314        Out << Node->getNumber() << ':';
315        return Out.str();
316      }
317
318      Node->print(Out);
319
320      std::string OutStr = Out.str();
321      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
322
323      // Process string output to make it nicer...
324      for (unsigned i = 0; i != OutStr.length(); ++i)
325        if (OutStr[i] == '\n') {                            // Left justify
326          OutStr[i] = '\\';
327          OutStr.insert(OutStr.begin()+i+1, 'l');
328        }
329      return OutStr;
330    }
331  };
332}
333
334void MachineFunction::viewCFG() const
335{
336#ifndef NDEBUG
337  ViewGraph(this, "mf" + getFunction()->getName());
338#else
339  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
340       << "systems with Graphviz or gv!\n";
341#endif // NDEBUG
342}
343
344void MachineFunction::viewCFGOnly() const
345{
346  CFGOnly = true;
347  viewCFG();
348  CFGOnly = false;
349}
350
351// The next two methods are used to construct and to retrieve
352// the MachineCodeForFunction object for the given function.
353// construct() -- Allocates and initializes for a given function and target
354// get()       -- Returns a handle to the object.
355//                This should not be called before "construct()"
356//                for a given Function.
357//
358MachineFunction&
359MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
360{
361  assert(Fn->getAnnotation(MF_AID) == 0 &&
362         "Object already exists for this function!");
363  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
364  Fn->addAnnotation(mcInfo);
365  return *mcInfo;
366}
367
368void MachineFunction::destruct(const Function *Fn) {
369  bool Deleted = Fn->deleteAnnotation(MF_AID);
370  assert(Deleted && "Machine code did not exist for function!");
371  Deleted = Deleted; // silence warning when no assertions.
372}
373
374MachineFunction& MachineFunction::get(const Function *F)
375{
376  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
377  assert(mc && "Call construct() method first to allocate the object");
378  return *mc;
379}
380
381/// lookUpDebugLocId - Look up the DebugLocTuple index with the given
382/// source file, line, and column. It may add a new filename and / or
383/// a new DebugLocTuple.
384unsigned MachineFunction::lookUpDebugLocId(unsigned Src, unsigned Line,
385                                           unsigned Col) {
386  struct DebugLocTuple Tuple(Src, Line, Col);
387  DebugIdMapType::iterator II = DebugLocInfo.DebugIdMap.find(Tuple);
388  if (II != DebugLocInfo.DebugIdMap.end())
389    return II->second;
390  // Add a new tuple.
391  DebugLocInfo.DebugLocations.push_back(Tuple);
392  DebugLocInfo.DebugIdMap[Tuple] = DebugLocInfo.NumDebugLocations;
393  return DebugLocInfo.NumDebugLocations++;
394}
395
396//===----------------------------------------------------------------------===//
397//  MachineFrameInfo implementation
398//===----------------------------------------------------------------------===//
399
400/// CreateFixedObject - Create a new object at a fixed location on the stack.
401/// All fixed objects should be created before other objects are created for
402/// efficiency. By default, fixed objects are immutable. This returns an
403/// index with a negative value.
404///
405int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
406                                        bool Immutable) {
407  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
408  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
409  return -++NumFixedObjects;
410}
411
412
413void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
414  const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
415  int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
416
417  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
418    const StackObject &SO = Objects[i];
419    OS << "  <fi#" << (int)(i-NumFixedObjects) << ">: ";
420    if (SO.Size == ~0ULL) {
421      OS << "dead\n";
422      continue;
423    }
424    if (SO.Size == 0)
425      OS << "variable sized";
426    else
427      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
428    OS << " alignment is " << SO.Alignment << " byte"
429       << (SO.Alignment != 1 ? "s," : ",");
430
431    if (i < NumFixedObjects)
432      OS << " fixed";
433    if (i < NumFixedObjects || SO.SPOffset != -1) {
434      int64_t Off = SO.SPOffset - ValOffset;
435      OS << " at location [SP";
436      if (Off > 0)
437        OS << "+" << Off;
438      else if (Off < 0)
439        OS << Off;
440      OS << "]";
441    }
442    OS << "\n";
443  }
444
445  if (HasVarSizedObjects)
446    OS << "  Stack frame contains variable sized objects\n";
447}
448
449void MachineFrameInfo::dump(const MachineFunction &MF) const {
450  print(MF, *cerr.stream());
451}
452
453
454//===----------------------------------------------------------------------===//
455//  MachineJumpTableInfo implementation
456//===----------------------------------------------------------------------===//
457
458/// getJumpTableIndex - Create a new jump table entry in the jump table info
459/// or return an existing one.
460///
461unsigned MachineJumpTableInfo::getJumpTableIndex(
462                               const std::vector<MachineBasicBlock*> &DestBBs) {
463  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
464  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
465    if (JumpTables[i].MBBs == DestBBs)
466      return i;
467
468  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
469  return JumpTables.size()-1;
470}
471
472
473void MachineJumpTableInfo::print(std::ostream &OS) const {
474  // FIXME: this is lame, maybe we could print out the MBB numbers or something
475  // like {1, 2, 4, 5, 3, 0}
476  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
477    OS << "  <jt#" << i << "> has " << JumpTables[i].MBBs.size()
478       << " entries\n";
479  }
480}
481
482void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
483
484
485//===----------------------------------------------------------------------===//
486//  MachineConstantPool implementation
487//===----------------------------------------------------------------------===//
488
489const Type *MachineConstantPoolEntry::getType() const {
490  if (isMachineConstantPoolEntry())
491      return Val.MachineCPVal->getType();
492  return Val.ConstVal->getType();
493}
494
495MachineConstantPool::~MachineConstantPool() {
496  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
497    if (Constants[i].isMachineConstantPoolEntry())
498      delete Constants[i].Val.MachineCPVal;
499}
500
501/// getConstantPoolIndex - Create a new entry in the constant pool or return
502/// an existing one.  User must specify the log2 of the minimum required
503/// alignment for the object.
504///
505unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
506                                                   unsigned Alignment) {
507  assert(Alignment && "Alignment must be specified!");
508  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
509
510  // Check to see if we already have this constant.
511  //
512  // FIXME, this could be made much more efficient for large constant pools.
513  unsigned AlignMask = (1 << Alignment)-1;
514  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
515    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
516      return i;
517
518  unsigned Offset = 0;
519  if (!Constants.empty()) {
520    Offset = Constants.back().getOffset();
521    Offset += TD->getTypePaddedSize(Constants.back().getType());
522    Offset = (Offset+AlignMask)&~AlignMask;
523  }
524
525  Constants.push_back(MachineConstantPoolEntry(C, Offset));
526  return Constants.size()-1;
527}
528
529unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
530                                                   unsigned Alignment) {
531  assert(Alignment && "Alignment must be specified!");
532  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
533
534  // Check to see if we already have this constant.
535  //
536  // FIXME, this could be made much more efficient for large constant pools.
537  unsigned AlignMask = (1 << Alignment)-1;
538  int Idx = V->getExistingMachineCPValue(this, Alignment);
539  if (Idx != -1)
540    return (unsigned)Idx;
541
542  unsigned Offset = 0;
543  if (!Constants.empty()) {
544    Offset = Constants.back().getOffset();
545    Offset += TD->getTypePaddedSize(Constants.back().getType());
546    Offset = (Offset+AlignMask)&~AlignMask;
547  }
548
549  Constants.push_back(MachineConstantPoolEntry(V, Offset));
550  return Constants.size()-1;
551}
552
553void MachineConstantPool::print(raw_ostream &OS) const {
554  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
555    OS << "  <cp#" << i << "> is";
556    if (Constants[i].isMachineConstantPoolEntry())
557      Constants[i].Val.MachineCPVal->print(OS);
558    else
559      OS << *(Value*)Constants[i].Val.ConstVal;
560    OS << " , offset=" << Constants[i].getOffset();
561    OS << "\n";
562  }
563}
564
565void MachineConstantPool::dump() const { print(errs()); errs().flush(); }
566