MachineFunction.cpp revision 80f3d46968c56bb93597248d7e0157e746c5ce1b 
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/ADT/STLExtras.h"
32#include "llvm/Config/config.h"
33#include <fstream>
34#include <sstream>
35using namespace llvm;
36
37static AnnotationID MF_AID(
38  AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
39
40// Out of line virtual function to home classes.
41void MachineFunctionPass::virtfn() {}
42
43namespace {
44  struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
45    static char ID;
46
47    std::ostream *OS;
48    const std::string Banner;
49
50    Printer (std::ostream *os, const std::string &banner)
51      : MachineFunctionPass((intptr_t)&ID), OS(os), Banner(banner) {}
52
53    const char *getPassName() const { return "MachineFunction Printer"; }
54
55    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
56      AU.setPreservesAll();
57    }
58
59    bool runOnMachineFunction(MachineFunction &MF) {
60      (*OS) << Banner;
61      MF.print (*OS);
62      return false;
63    }
64  };
65  char Printer::ID = 0;
66}
67
68/// Returns a newly-created MachineFunction Printer pass. The default output
69/// stream is std::cerr; the default banner is empty.
70///
71FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
72                                                     const std::string &Banner){
73  return new Printer(OS, Banner);
74}
75
76namespace {
77  struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
78    static char ID;
79    Deleter() : MachineFunctionPass((intptr_t)&ID) {}
80
81    const char *getPassName() const { return "Machine Code Deleter"; }
82
83    bool runOnMachineFunction(MachineFunction &MF) {
84      // Delete the annotation from the function now.
85      MachineFunction::destruct(MF.getFunction());
86      return true;
87    }
88  };
89  char Deleter::ID = 0;
90}
91
92/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
93/// the current function, which should happen after the function has been
94/// emitted to a .s file or to memory.
95FunctionPass *llvm::createMachineCodeDeleter() {
96  return new Deleter();
97}
98
99
100
101//===---------------------------------------------------------------------===//
102// MachineFunction implementation
103//===---------------------------------------------------------------------===//
104
105void alist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
106  MBB->getParent()->DeleteMachineBasicBlock(MBB);
107}
108
109MachineFunction::MachineFunction(const Function *F,
110                                 const TargetMachine &TM)
111  : Annotation(MF_AID), Fn(F), Target(TM) {
112  RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
113                MachineRegisterInfo(*TM.getRegisterInfo());
114  MFInfo = 0;
115  FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
116                  MachineFrameInfo(*TM.getFrameInfo());
117  ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
118                     MachineConstantPool(TM.getTargetData());
119
120  // Set up jump table.
121  const TargetData &TD = *TM.getTargetData();
122  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
123  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
124  unsigned Alignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
125                             : TD.getPointerABIAlignment();
126  JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
127                      MachineJumpTableInfo(EntrySize, Alignment);
128}
129
130MachineFunction::~MachineFunction() {
131  BasicBlocks.clear();
132  InstructionRecycler.clear(Allocator);
133  BasicBlockRecycler.clear(Allocator);
134  MemOperandRecycler.clear(Allocator);
135  RegInfo->~MachineRegisterInfo();        Allocator.Deallocate(RegInfo);
136  if (MFInfo) {
137    MFInfo->~MachineFunctionInfo();       Allocator.Deallocate(MFInfo);
138  }
139  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
140  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
141  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
142}
143
144
145/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
146/// recomputes them.  This guarantees that the MBB numbers are sequential,
147/// dense, and match the ordering of the blocks within the function.  If a
148/// specific MachineBasicBlock is specified, only that block and those after
149/// it are renumbered.
150void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
151  if (empty()) { MBBNumbering.clear(); return; }
152  MachineFunction::iterator MBBI, E = end();
153  if (MBB == 0)
154    MBBI = begin();
155  else
156    MBBI = MBB;
157
158  // Figure out the block number this should have.
159  unsigned BlockNo = 0;
160  if (MBBI != begin())
161    BlockNo = prior(MBBI)->getNumber()+1;
162
163  for (; MBBI != E; ++MBBI, ++BlockNo) {
164    if (MBBI->getNumber() != (int)BlockNo) {
165      // Remove use of the old number.
166      if (MBBI->getNumber() != -1) {
167        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
168               "MBB number mismatch!");
169        MBBNumbering[MBBI->getNumber()] = 0;
170      }
171
172      // If BlockNo is already taken, set that block's number to -1.
173      if (MBBNumbering[BlockNo])
174        MBBNumbering[BlockNo]->setNumber(-1);
175
176      MBBNumbering[BlockNo] = MBBI;
177      MBBI->setNumber(BlockNo);
178    }
179  }
180
181  // Okay, all the blocks are renumbered.  If we have compactified the block
182  // numbering, shrink MBBNumbering now.
183  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
184  MBBNumbering.resize(BlockNo);
185}
186
187/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
188/// of `new MachineInstr'.
189///
190MachineInstr *
191MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID, bool NoImp) {
192  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
193             MachineInstr(TID, NoImp);
194}
195
196/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
197/// 'Orig' instruction, identical in all ways except the the instruction
198/// has no parent, prev, or next.
199///
200MachineInstr *
201MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
202  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
203             MachineInstr(*this, *Orig);
204}
205
206/// DeleteMachineInstr - Delete the given MachineInstr.
207///
208void
209MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
210  // Clear the instructions memoperands. This must be done manually because
211  // the instruction's parent pointer is now null, so it can't properly
212  // deallocate them on its own.
213  MI->clearMemOperands(*this);
214
215  MI->~MachineInstr();
216  InstructionRecycler.Deallocate(Allocator, MI);
217}
218
219/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
220/// instead of `new MachineBasicBlock'.
221///
222MachineBasicBlock *
223MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
224  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
225             MachineBasicBlock(*this, bb);
226}
227
228/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
229///
230void
231MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
232  assert(MBB->getParent() == this && "MBB parent mismatch!");
233  MBB->~MachineBasicBlock();
234  BasicBlockRecycler.Deallocate(Allocator, MBB);
235}
236
237/// CreateMachineMemOperand - Allocate a new MachineMemOperand. Use this
238/// instead of `new MachineMemOperand'.
239///
240MachineMemOperand *
241MachineFunction::CreateMachineMemOperand(const MachineMemOperand &MMO) {
242  return new (MemOperandRecycler.Allocate<MachineMemOperand>(Allocator))
243             MachineMemOperand(MMO);
244}
245
246/// DeleteMachineMemOperand - Delete the given MachineMemOperand.
247///
248void
249MachineFunction::DeleteMachineMemOperand(MachineMemOperand *MO) {
250  MO->~MachineMemOperand();
251  MemOperandRecycler.Deallocate(Allocator, MO);
252}
253
254void MachineFunction::dump() const {
255  print(*cerr.stream());
256}
257
258void MachineFunction::print(std::ostream &OS) const {
259  OS << "# Machine code for " << Fn->getName () << "():\n";
260
261  // Print Frame Information
262  FrameInfo->print(*this, OS);
263
264  // Print JumpTable Information
265  JumpTableInfo->print(OS);
266
267  // Print Constant Pool
268  ConstantPool->print(OS);
269
270  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
271
272  if (!RegInfo->livein_empty()) {
273    OS << "Live Ins:";
274    for (MachineRegisterInfo::livein_iterator
275         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
276      if (TRI)
277        OS << " " << TRI->getName(I->first);
278      else
279        OS << " Reg #" << I->first;
280
281      if (I->second)
282        OS << " in VR#" << I->second << " ";
283    }
284    OS << "\n";
285  }
286  if (!RegInfo->liveout_empty()) {
287    OS << "Live Outs:";
288    for (MachineRegisterInfo::liveout_iterator
289         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
290      if (TRI)
291        OS << " " << TRI->getName(*I);
292      else
293        OS << " Reg #" << *I;
294    OS << "\n";
295  }
296
297  for (const_iterator BB = begin(); BB != end(); ++BB)
298    BB->print(OS);
299
300  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
301}
302
303/// CFGOnly flag - This is used to control whether or not the CFG graph printer
304/// prints out the contents of basic blocks or not.  This is acceptable because
305/// this code is only really used for debugging purposes.
306///
307static bool CFGOnly = false;
308
309namespace llvm {
310  template<>
311  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
312    static std::string getGraphName(const MachineFunction *F) {
313      return "CFG for '" + F->getFunction()->getName() + "' function";
314    }
315
316    static std::string getNodeLabel(const MachineBasicBlock *Node,
317                                    const MachineFunction *Graph) {
318      if (CFGOnly && Node->getBasicBlock() &&
319          !Node->getBasicBlock()->getName().empty())
320        return Node->getBasicBlock()->getName() + ":";
321
322      std::ostringstream Out;
323      if (CFGOnly) {
324        Out << Node->getNumber() << ':';
325        return Out.str();
326      }
327
328      Node->print(Out);
329
330      std::string OutStr = Out.str();
331      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
332
333      // Process string output to make it nicer...
334      for (unsigned i = 0; i != OutStr.length(); ++i)
335        if (OutStr[i] == '\n') {                            // Left justify
336          OutStr[i] = '\\';
337          OutStr.insert(OutStr.begin()+i+1, 'l');
338        }
339      return OutStr;
340    }
341  };
342}
343
344void MachineFunction::viewCFG() const
345{
346#ifndef NDEBUG
347  ViewGraph(this, "mf" + getFunction()->getName());
348#else
349  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
350       << "systems with Graphviz or gv!\n";
351#endif // NDEBUG
352}
353
354void MachineFunction::viewCFGOnly() const
355{
356  CFGOnly = true;
357  viewCFG();
358  CFGOnly = false;
359}
360
361// The next two methods are used to construct and to retrieve
362// the MachineCodeForFunction object for the given function.
363// construct() -- Allocates and initializes for a given function and target
364// get()       -- Returns a handle to the object.
365//                This should not be called before "construct()"
366//                for a given Function.
367//
368MachineFunction&
369MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
370{
371  assert(Fn->getAnnotation(MF_AID) == 0 &&
372         "Object already exists for this function!");
373  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
374  Fn->addAnnotation(mcInfo);
375  return *mcInfo;
376}
377
378void MachineFunction::destruct(const Function *Fn) {
379  bool Deleted = Fn->deleteAnnotation(MF_AID);
380  assert(Deleted && "Machine code did not exist for function!");
381  Deleted = Deleted; // silence warning when no assertions.
382}
383
384MachineFunction& MachineFunction::get(const Function *F)
385{
386  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
387  assert(mc && "Call construct() method first to allocate the object");
388  return *mc;
389}
390
391//===----------------------------------------------------------------------===//
392//  MachineFrameInfo implementation
393//===----------------------------------------------------------------------===//
394
395/// CreateFixedObject - Create a new object at a fixed location on the stack.
396/// All fixed objects should be created before other objects are created for
397/// efficiency. By default, fixed objects are immutable. This returns an
398/// index with a negative value.
399///
400int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
401                                        bool Immutable) {
402  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
403  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
404  return -++NumFixedObjects;
405}
406
407
408void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
409  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
410
411  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
412    const StackObject &SO = Objects[i];
413    OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
414    if (SO.Size == ~0ULL) {
415      OS << "dead\n";
416      continue;
417    }
418    if (SO.Size == 0)
419      OS << "variable sized";
420    else
421      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
422    OS << " alignment is " << SO.Alignment << " byte"
423       << (SO.Alignment != 1 ? "s," : ",");
424
425    if (i < NumFixedObjects)
426      OS << " fixed";
427    if (i < NumFixedObjects || SO.SPOffset != -1) {
428      int64_t Off = SO.SPOffset - ValOffset;
429      OS << " at location [SP";
430      if (Off > 0)
431        OS << "+" << Off;
432      else if (Off < 0)
433        OS << Off;
434      OS << "]";
435    }
436    OS << "\n";
437  }
438
439  if (HasVarSizedObjects)
440    OS << "  Stack frame contains variable sized objects\n";
441}
442
443void MachineFrameInfo::dump(const MachineFunction &MF) const {
444  print(MF, *cerr.stream());
445}
446
447
448//===----------------------------------------------------------------------===//
449//  MachineJumpTableInfo implementation
450//===----------------------------------------------------------------------===//
451
452/// getJumpTableIndex - Create a new jump table entry in the jump table info
453/// or return an existing one.
454///
455unsigned MachineJumpTableInfo::getJumpTableIndex(
456                               const std::vector<MachineBasicBlock*> &DestBBs) {
457  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
458  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
459    if (JumpTables[i].MBBs == DestBBs)
460      return i;
461
462  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
463  return JumpTables.size()-1;
464}
465
466
467void MachineJumpTableInfo::print(std::ostream &OS) const {
468  // FIXME: this is lame, maybe we could print out the MBB numbers or something
469  // like {1, 2, 4, 5, 3, 0}
470  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
471    OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size()
472       << " entries\n";
473  }
474}
475
476void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
477
478
479//===----------------------------------------------------------------------===//
480//  MachineConstantPool implementation
481//===----------------------------------------------------------------------===//
482
483const Type *MachineConstantPoolEntry::getType() const {
484  if (isMachineConstantPoolEntry())
485      return Val.MachineCPVal->getType();
486  return Val.ConstVal->getType();
487}
488
489MachineConstantPool::~MachineConstantPool() {
490  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
491    if (Constants[i].isMachineConstantPoolEntry())
492      delete Constants[i].Val.MachineCPVal;
493}
494
495/// getConstantPoolIndex - Create a new entry in the constant pool or return
496/// an existing one.  User must specify an alignment in bytes for the object.
497///
498unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
499                                                   unsigned Alignment) {
500  assert(Alignment && "Alignment must be specified!");
501  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
502
503  // Check to see if we already have this constant.
504  //
505  // FIXME, this could be made much more efficient for large constant pools.
506  unsigned AlignMask = (1 << Alignment)-1;
507  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
508    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
509      return i;
510
511  unsigned Offset = 0;
512  if (!Constants.empty()) {
513    Offset = Constants.back().getOffset();
514    Offset += TD->getABITypeSize(Constants.back().getType());
515    Offset = (Offset+AlignMask)&~AlignMask;
516  }
517
518  Constants.push_back(MachineConstantPoolEntry(C, Offset));
519  return Constants.size()-1;
520}
521
522unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
523                                                   unsigned Alignment) {
524  assert(Alignment && "Alignment must be specified!");
525  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
526
527  // Check to see if we already have this constant.
528  //
529  // FIXME, this could be made much more efficient for large constant pools.
530  unsigned AlignMask = (1 << Alignment)-1;
531  int Idx = V->getExistingMachineCPValue(this, Alignment);
532  if (Idx != -1)
533    return (unsigned)Idx;
534
535  unsigned Offset = 0;
536  if (!Constants.empty()) {
537    Offset = Constants.back().getOffset();
538    Offset += TD->getABITypeSize(Constants.back().getType());
539    Offset = (Offset+AlignMask)&~AlignMask;
540  }
541
542  Constants.push_back(MachineConstantPoolEntry(V, Offset));
543  return Constants.size()-1;
544}
545
546
547void MachineConstantPool::print(std::ostream &OS) const {
548  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
549    OS << "  <cp #" << i << "> is";
550    if (Constants[i].isMachineConstantPoolEntry())
551      Constants[i].Val.MachineCPVal->print(OS);
552    else
553      OS << *(Value*)Constants[i].Val.ConstVal;
554    OS << " , offset=" << Constants[i].getOffset();
555    OS << "\n";
556  }
557}
558
559void MachineConstantPool::dump() const { print(*cerr.stream()); }
560