MachineFunction.cpp revision 2fcbc7e8303dfee61147d76bbf16ed0297133c77 
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 ilist_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  RegInfo->~MachineRegisterInfo();        Allocator.Deallocate(RegInfo);
135  if (MFInfo) {
136    MFInfo->~MachineFunctionInfo();       Allocator.Deallocate(MFInfo);
137  }
138  FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
139  ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
140  JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
141}
142
143
144/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
145/// recomputes them.  This guarantees that the MBB numbers are sequential,
146/// dense, and match the ordering of the blocks within the function.  If a
147/// specific MachineBasicBlock is specified, only that block and those after
148/// it are renumbered.
149void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
150  if (empty()) { MBBNumbering.clear(); return; }
151  MachineFunction::iterator MBBI, E = end();
152  if (MBB == 0)
153    MBBI = begin();
154  else
155    MBBI = MBB;
156
157  // Figure out the block number this should have.
158  unsigned BlockNo = 0;
159  if (MBBI != begin())
160    BlockNo = prior(MBBI)->getNumber()+1;
161
162  for (; MBBI != E; ++MBBI, ++BlockNo) {
163    if (MBBI->getNumber() != (int)BlockNo) {
164      // Remove use of the old number.
165      if (MBBI->getNumber() != -1) {
166        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
167               "MBB number mismatch!");
168        MBBNumbering[MBBI->getNumber()] = 0;
169      }
170
171      // If BlockNo is already taken, set that block's number to -1.
172      if (MBBNumbering[BlockNo])
173        MBBNumbering[BlockNo]->setNumber(-1);
174
175      MBBNumbering[BlockNo] = MBBI;
176      MBBI->setNumber(BlockNo);
177    }
178  }
179
180  // Okay, all the blocks are renumbered.  If we have compactified the block
181  // numbering, shrink MBBNumbering now.
182  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
183  MBBNumbering.resize(BlockNo);
184}
185
186/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
187/// of `new MachineInstr'.
188///
189MachineInstr *
190MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID, bool NoImp) {
191  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
192             MachineInstr(TID, NoImp);
193}
194
195/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
196/// 'Orig' instruction, identical in all ways except the the instruction
197/// has no parent, prev, or next.
198///
199MachineInstr *
200MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
201  return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
202             MachineInstr(*this, *Orig);
203}
204
205/// DeleteMachineInstr - Delete the given MachineInstr.
206///
207void
208MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
209  // Clear the instructions memoperands. This must be done manually because
210  // the instruction's parent pointer is now null, so it can't properly
211  // deallocate them on its own.
212  MI->clearMemOperands(*this);
213
214  MI->~MachineInstr();
215  InstructionRecycler.Deallocate(Allocator, MI);
216}
217
218/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
219/// instead of `new MachineBasicBlock'.
220///
221MachineBasicBlock *
222MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
223  return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
224             MachineBasicBlock(*this, bb);
225}
226
227/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
228///
229void
230MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
231  assert(MBB->getParent() == this && "MBB parent mismatch!");
232  MBB->~MachineBasicBlock();
233  BasicBlockRecycler.Deallocate(Allocator, MBB);
234}
235
236void MachineFunction::dump() const {
237  print(*cerr.stream());
238}
239
240void MachineFunction::print(std::ostream &OS) const {
241  OS << "# Machine code for " << Fn->getName () << "():\n";
242
243  // Print Frame Information
244  FrameInfo->print(*this, OS);
245
246  // Print JumpTable Information
247  JumpTableInfo->print(OS);
248
249  // Print Constant Pool
250  ConstantPool->print(OS);
251
252  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
253
254  if (!RegInfo->livein_empty()) {
255    OS << "Live Ins:";
256    for (MachineRegisterInfo::livein_iterator
257         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
258      if (TRI)
259        OS << " " << TRI->getName(I->first);
260      else
261        OS << " Reg #" << I->first;
262
263      if (I->second)
264        OS << " in VR#" << I->second << " ";
265    }
266    OS << "\n";
267  }
268  if (!RegInfo->liveout_empty()) {
269    OS << "Live Outs:";
270    for (MachineRegisterInfo::liveout_iterator
271         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
272      if (TRI)
273        OS << " " << TRI->getName(*I);
274      else
275        OS << " Reg #" << *I;
276    OS << "\n";
277  }
278
279  for (const_iterator BB = begin(); BB != end(); ++BB)
280    BB->print(OS);
281
282  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
283}
284
285/// CFGOnly flag - This is used to control whether or not the CFG graph printer
286/// prints out the contents of basic blocks or not.  This is acceptable because
287/// this code is only really used for debugging purposes.
288///
289static bool CFGOnly = false;
290
291namespace llvm {
292  template<>
293  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
294    static std::string getGraphName(const MachineFunction *F) {
295      return "CFG for '" + F->getFunction()->getName() + "' function";
296    }
297
298    static std::string getNodeLabel(const MachineBasicBlock *Node,
299                                    const MachineFunction *Graph) {
300      if (CFGOnly && Node->getBasicBlock() &&
301          !Node->getBasicBlock()->getName().empty())
302        return Node->getBasicBlock()->getName() + ":";
303
304      std::ostringstream Out;
305      if (CFGOnly) {
306        Out << Node->getNumber() << ':';
307        return Out.str();
308      }
309
310      Node->print(Out);
311
312      std::string OutStr = Out.str();
313      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
314
315      // Process string output to make it nicer...
316      for (unsigned i = 0; i != OutStr.length(); ++i)
317        if (OutStr[i] == '\n') {                            // Left justify
318          OutStr[i] = '\\';
319          OutStr.insert(OutStr.begin()+i+1, 'l');
320        }
321      return OutStr;
322    }
323  };
324}
325
326void MachineFunction::viewCFG() const
327{
328#ifndef NDEBUG
329  ViewGraph(this, "mf" + getFunction()->getName());
330#else
331  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
332       << "systems with Graphviz or gv!\n";
333#endif // NDEBUG
334}
335
336void MachineFunction::viewCFGOnly() const
337{
338  CFGOnly = true;
339  viewCFG();
340  CFGOnly = false;
341}
342
343// The next two methods are used to construct and to retrieve
344// the MachineCodeForFunction object for the given function.
345// construct() -- Allocates and initializes for a given function and target
346// get()       -- Returns a handle to the object.
347//                This should not be called before "construct()"
348//                for a given Function.
349//
350MachineFunction&
351MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
352{
353  assert(Fn->getAnnotation(MF_AID) == 0 &&
354         "Object already exists for this function!");
355  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
356  Fn->addAnnotation(mcInfo);
357  return *mcInfo;
358}
359
360void MachineFunction::destruct(const Function *Fn) {
361  bool Deleted = Fn->deleteAnnotation(MF_AID);
362  assert(Deleted && "Machine code did not exist for function!");
363  Deleted = Deleted; // silence warning when no assertions.
364}
365
366MachineFunction& MachineFunction::get(const Function *F)
367{
368  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
369  assert(mc && "Call construct() method first to allocate the object");
370  return *mc;
371}
372
373//===----------------------------------------------------------------------===//
374//  MachineFrameInfo implementation
375//===----------------------------------------------------------------------===//
376
377/// CreateFixedObject - Create a new object at a fixed location on the stack.
378/// All fixed objects should be created before other objects are created for
379/// efficiency. By default, fixed objects are immutable. This returns an
380/// index with a negative value.
381///
382int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
383                                        bool Immutable) {
384  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
385  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
386  return -++NumFixedObjects;
387}
388
389
390void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
391  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
392
393  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
394    const StackObject &SO = Objects[i];
395    OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
396    if (SO.Size == ~0ULL) {
397      OS << "dead\n";
398      continue;
399    }
400    if (SO.Size == 0)
401      OS << "variable sized";
402    else
403      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
404    OS << " alignment is " << SO.Alignment << " byte"
405       << (SO.Alignment != 1 ? "s," : ",");
406
407    if (i < NumFixedObjects)
408      OS << " fixed";
409    if (i < NumFixedObjects || SO.SPOffset != -1) {
410      int64_t Off = SO.SPOffset - ValOffset;
411      OS << " at location [SP";
412      if (Off > 0)
413        OS << "+" << Off;
414      else if (Off < 0)
415        OS << Off;
416      OS << "]";
417    }
418    OS << "\n";
419  }
420
421  if (HasVarSizedObjects)
422    OS << "  Stack frame contains variable sized objects\n";
423}
424
425void MachineFrameInfo::dump(const MachineFunction &MF) const {
426  print(MF, *cerr.stream());
427}
428
429
430//===----------------------------------------------------------------------===//
431//  MachineJumpTableInfo implementation
432//===----------------------------------------------------------------------===//
433
434/// getJumpTableIndex - Create a new jump table entry in the jump table info
435/// or return an existing one.
436///
437unsigned MachineJumpTableInfo::getJumpTableIndex(
438                               const std::vector<MachineBasicBlock*> &DestBBs) {
439  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
440  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
441    if (JumpTables[i].MBBs == DestBBs)
442      return i;
443
444  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
445  return JumpTables.size()-1;
446}
447
448
449void MachineJumpTableInfo::print(std::ostream &OS) const {
450  // FIXME: this is lame, maybe we could print out the MBB numbers or something
451  // like {1, 2, 4, 5, 3, 0}
452  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
453    OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size()
454       << " entries\n";
455  }
456}
457
458void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
459
460
461//===----------------------------------------------------------------------===//
462//  MachineConstantPool implementation
463//===----------------------------------------------------------------------===//
464
465const Type *MachineConstantPoolEntry::getType() const {
466  if (isMachineConstantPoolEntry())
467      return Val.MachineCPVal->getType();
468  return Val.ConstVal->getType();
469}
470
471MachineConstantPool::~MachineConstantPool() {
472  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
473    if (Constants[i].isMachineConstantPoolEntry())
474      delete Constants[i].Val.MachineCPVal;
475}
476
477/// getConstantPoolIndex - Create a new entry in the constant pool or return
478/// an existing one.  User must specify an alignment in bytes for the object.
479///
480unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
481                                                   unsigned Alignment) {
482  assert(Alignment && "Alignment must be specified!");
483  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
484
485  // Check to see if we already have this constant.
486  //
487  // FIXME, this could be made much more efficient for large constant pools.
488  unsigned AlignMask = (1 << Alignment)-1;
489  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
490    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
491      return i;
492
493  unsigned Offset = 0;
494  if (!Constants.empty()) {
495    Offset = Constants.back().getOffset();
496    Offset += TD->getABITypeSize(Constants.back().getType());
497    Offset = (Offset+AlignMask)&~AlignMask;
498  }
499
500  Constants.push_back(MachineConstantPoolEntry(C, Offset));
501  return Constants.size()-1;
502}
503
504unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
505                                                   unsigned Alignment) {
506  assert(Alignment && "Alignment must be specified!");
507  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
508
509  // Check to see if we already have this constant.
510  //
511  // FIXME, this could be made much more efficient for large constant pools.
512  unsigned AlignMask = (1 << Alignment)-1;
513  int Idx = V->getExistingMachineCPValue(this, Alignment);
514  if (Idx != -1)
515    return (unsigned)Idx;
516
517  unsigned Offset = 0;
518  if (!Constants.empty()) {
519    Offset = Constants.back().getOffset();
520    Offset += TD->getABITypeSize(Constants.back().getType());
521    Offset = (Offset+AlignMask)&~AlignMask;
522  }
523
524  Constants.push_back(MachineConstantPoolEntry(V, Offset));
525  return Constants.size()-1;
526}
527
528
529void MachineConstantPool::print(std::ostream &OS) const {
530  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
531    OS << "  <cp #" << i << "> is";
532    if (Constants[i].isMachineConstantPoolEntry())
533      Constants[i].Val.MachineCPVal->print(OS);
534    else
535      OS << *(Value*)Constants[i].Val.ConstVal;
536    OS << " , offset=" << Constants[i].getOffset();
537    OS << "\n";
538  }
539}
540
541void MachineConstantPool::dump() const { print(*cerr.stream()); }
542