MachineFunction.cpp revision d472ad7c7cb9378367bdc105dd208f80c7cd5998 
1//===-- MachineFunction.cpp -----------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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/CodeGen/MachineFunctionPass.h"
17#include "llvm/CodeGen/MachineInstr.h"
18#include "llvm/CodeGen/SSARegMap.h"
19#include "llvm/CodeGen/MachineFrameInfo.h"
20#include "llvm/CodeGen/MachineConstantPool.h"
21#include "llvm/CodeGen/MachineJumpTableInfo.h"
22#include "llvm/CodeGen/Passes.h"
23#include "llvm/Target/TargetData.h"
24#include "llvm/Target/TargetLowering.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/LeakDetector.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    std::ostream *OS;
47    const std::string Banner;
48
49    Printer (std::ostream *_OS, const std::string &_Banner) :
50      OS (_OS), Banner (_Banner) { }
51
52    const char *getPassName() const { return "MachineFunction Printer"; }
53
54    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
55      AU.setPreservesAll();
56    }
57
58    bool runOnMachineFunction(MachineFunction &MF) {
59      (*OS) << Banner;
60      MF.print (*OS);
61      return false;
62    }
63  };
64}
65
66/// Returns a newly-created MachineFunction Printer pass. The default output
67/// stream is std::cerr; the default banner is empty.
68///
69FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
70                                                     const std::string &Banner){
71  return new Printer(OS, Banner);
72}
73
74namespace {
75  struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
76    const char *getPassName() const { return "Machine Code Deleter"; }
77
78    bool runOnMachineFunction(MachineFunction &MF) {
79      // Delete the annotation from the function now.
80      MachineFunction::destruct(MF.getFunction());
81      return true;
82    }
83  };
84}
85
86/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
87/// the current function, which should happen after the function has been
88/// emitted to a .s file or to memory.
89FunctionPass *llvm::createMachineCodeDeleter() {
90  return new Deleter();
91}
92
93
94
95//===---------------------------------------------------------------------===//
96// MachineFunction implementation
97//===---------------------------------------------------------------------===//
98
99MachineBasicBlock* ilist_traits<MachineBasicBlock>::createSentinel() {
100  MachineBasicBlock* dummy = new MachineBasicBlock();
101  LeakDetector::removeGarbageObject(dummy);
102  return dummy;
103}
104
105void ilist_traits<MachineBasicBlock>::transferNodesFromList(
106  iplist<MachineBasicBlock, ilist_traits<MachineBasicBlock> >& toList,
107  ilist_iterator<MachineBasicBlock> first,
108  ilist_iterator<MachineBasicBlock> last) {
109  if (Parent != toList.Parent)
110    for (; first != last; ++first)
111      first->Parent = toList.Parent;
112}
113
114MachineFunction::MachineFunction(const Function *F,
115                                 const TargetMachine &TM)
116  : Annotation(MF_AID), Fn(F), Target(TM), UsedPhysRegs(0) {
117  SSARegMapping = new SSARegMap();
118  MFInfo = 0;
119  FrameInfo = new MachineFrameInfo();
120  ConstantPool = new MachineConstantPool(TM.getTargetData());
121
122  // Set up jump table.
123  const TargetData &TD = *TM.getTargetData();
124  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
125  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
126  unsigned Alignment = IsPic ? TD.getIntAlignment() : TD.getPointerAlignment();
127  JumpTableInfo = new MachineJumpTableInfo(EntrySize, Alignment);
128
129  BasicBlocks.Parent = this;
130}
131
132MachineFunction::~MachineFunction() {
133  BasicBlocks.clear();
134  delete SSARegMapping;
135  delete MFInfo;
136  delete FrameInfo;
137  delete ConstantPool;
138  delete JumpTableInfo;
139  delete[] UsedPhysRegs;
140}
141
142
143/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
144/// recomputes them.  This guarantees that the MBB numbers are sequential,
145/// dense, and match the ordering of the blocks within the function.  If a
146/// specific MachineBasicBlock is specified, only that block and those after
147/// it are renumbered.
148void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
149  if (empty()) { MBBNumbering.clear(); return; }
150  MachineFunction::iterator MBBI, E = end();
151  if (MBB == 0)
152    MBBI = begin();
153  else
154    MBBI = MBB;
155
156  // Figure out the block number this should have.
157  unsigned BlockNo = 0;
158  if (MBBI != begin())
159    BlockNo = prior(MBBI)->getNumber()+1;
160
161  for (; MBBI != E; ++MBBI, ++BlockNo) {
162    if (MBBI->getNumber() != (int)BlockNo) {
163      // Remove use of the old number.
164      if (MBBI->getNumber() != -1) {
165        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
166               "MBB number mismatch!");
167        MBBNumbering[MBBI->getNumber()] = 0;
168      }
169
170      // If BlockNo is already taken, set that block's number to -1.
171      if (MBBNumbering[BlockNo])
172        MBBNumbering[BlockNo]->setNumber(-1);
173
174      MBBNumbering[BlockNo] = MBBI;
175      MBBI->setNumber(BlockNo);
176    }
177  }
178
179  // Okay, all the blocks are renumbered.  If we have compactified the block
180  // numbering, shrink MBBNumbering now.
181  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
182  MBBNumbering.resize(BlockNo);
183}
184
185
186void MachineFunction::dump() const { print(*cerr.stream()); }
187
188void MachineFunction::print(std::ostream &OS) const {
189  OS << "# Machine code for " << Fn->getName () << "():\n";
190
191  // Print Frame Information
192  getFrameInfo()->print(*this, OS);
193
194  // Print JumpTable Information
195  getJumpTableInfo()->print(OS);
196
197  // Print Constant Pool
198  getConstantPool()->print(OS);
199
200  const MRegisterInfo *MRI = getTarget().getRegisterInfo();
201
202  if (livein_begin() != livein_end()) {
203    OS << "Live Ins:";
204    for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I) {
205      if (MRI)
206        OS << " " << MRI->getName(I->first);
207      else
208        OS << " Reg #" << I->first;
209
210      if (I->second)
211        OS << " in VR#" << I->second << " ";
212    }
213    OS << "\n";
214  }
215  if (liveout_begin() != liveout_end()) {
216    OS << "Live Outs:";
217    for (liveout_iterator I = liveout_begin(), E = liveout_end(); I != E; ++I)
218      if (MRI)
219        OS << " " << MRI->getName(*I);
220      else
221        OS << " Reg #" << *I;
222    OS << "\n";
223  }
224
225  for (const_iterator BB = begin(); BB != end(); ++BB)
226    BB->print(OS);
227
228  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
229}
230
231/// CFGOnly flag - This is used to control whether or not the CFG graph printer
232/// prints out the contents of basic blocks or not.  This is acceptable because
233/// this code is only really used for debugging purposes.
234///
235static bool CFGOnly = false;
236
237namespace llvm {
238  template<>
239  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
240    static std::string getGraphName(const MachineFunction *F) {
241      return "CFG for '" + F->getFunction()->getName() + "' function";
242    }
243
244    static std::string getNodeLabel(const MachineBasicBlock *Node,
245                                    const MachineFunction *Graph) {
246      if (CFGOnly && Node->getBasicBlock() &&
247          !Node->getBasicBlock()->getName().empty())
248        return Node->getBasicBlock()->getName() + ":";
249
250      std::ostringstream Out;
251      if (CFGOnly) {
252        Out << Node->getNumber() << ':';
253        return Out.str();
254      }
255
256      Node->print(Out);
257
258      std::string OutStr = Out.str();
259      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
260
261      // Process string output to make it nicer...
262      for (unsigned i = 0; i != OutStr.length(); ++i)
263        if (OutStr[i] == '\n') {                            // Left justify
264          OutStr[i] = '\\';
265          OutStr.insert(OutStr.begin()+i+1, 'l');
266        }
267      return OutStr;
268    }
269  };
270}
271
272void MachineFunction::viewCFG() const
273{
274#ifndef NDEBUG
275  ViewGraph(this, "mf" + getFunction()->getName());
276#else
277  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
278       << "systems with Graphviz or gv!\n";
279#endif // NDEBUG
280}
281
282void MachineFunction::viewCFGOnly() const
283{
284  CFGOnly = true;
285  viewCFG();
286  CFGOnly = false;
287}
288
289// The next two methods are used to construct and to retrieve
290// the MachineCodeForFunction object for the given function.
291// construct() -- Allocates and initializes for a given function and target
292// get()       -- Returns a handle to the object.
293//                This should not be called before "construct()"
294//                for a given Function.
295//
296MachineFunction&
297MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
298{
299  assert(Fn->getAnnotation(MF_AID) == 0 &&
300         "Object already exists for this function!");
301  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
302  Fn->addAnnotation(mcInfo);
303  return *mcInfo;
304}
305
306void MachineFunction::destruct(const Function *Fn) {
307  bool Deleted = Fn->deleteAnnotation(MF_AID);
308  assert(Deleted && "Machine code did not exist for function!");
309}
310
311MachineFunction& MachineFunction::get(const Function *F)
312{
313  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
314  assert(mc && "Call construct() method first to allocate the object");
315  return *mc;
316}
317
318void MachineFunction::clearSSARegMap() {
319  delete SSARegMapping;
320  SSARegMapping = 0;
321}
322
323//===----------------------------------------------------------------------===//
324//  MachineFrameInfo implementation
325//===----------------------------------------------------------------------===//
326
327void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
328  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
329
330  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
331    const StackObject &SO = Objects[i];
332    OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
333    if (SO.Size == 0)
334      OS << "variable sized";
335    else
336      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
337    OS << " alignment is " << SO.Alignment << " byte"
338       << (SO.Alignment != 1 ? "s," : ",");
339
340    if (i < NumFixedObjects)
341      OS << " fixed";
342    if (i < NumFixedObjects || SO.SPOffset != -1) {
343      int Off = SO.SPOffset - ValOffset;
344      OS << " at location [SP";
345      if (Off > 0)
346        OS << "+" << Off;
347      else if (Off < 0)
348        OS << Off;
349      OS << "]";
350    }
351    OS << "\n";
352  }
353
354  if (HasVarSizedObjects)
355    OS << "  Stack frame contains variable sized objects\n";
356}
357
358void MachineFrameInfo::dump(const MachineFunction &MF) const {
359  print(MF, *cerr.stream());
360}
361
362
363//===----------------------------------------------------------------------===//
364//  MachineJumpTableInfo implementation
365//===----------------------------------------------------------------------===//
366
367/// getJumpTableIndex - Create a new jump table entry in the jump table info
368/// or return an existing one.
369///
370unsigned MachineJumpTableInfo::getJumpTableIndex(
371                               const std::vector<MachineBasicBlock*> &DestBBs) {
372  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
373  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
374    if (JumpTables[i].MBBs == DestBBs)
375      return i;
376
377  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
378  return JumpTables.size()-1;
379}
380
381
382void MachineJumpTableInfo::print(std::ostream &OS) const {
383  // FIXME: this is lame, maybe we could print out the MBB numbers or something
384  // like {1, 2, 4, 5, 3, 0}
385  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
386    OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size()
387       << " entries\n";
388  }
389}
390
391void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
392
393
394//===----------------------------------------------------------------------===//
395//  MachineConstantPool implementation
396//===----------------------------------------------------------------------===//
397
398const Type *MachineConstantPoolEntry::getType() const {
399  if (isMachineConstantPoolEntry())
400      return Val.MachineCPVal->getType();
401  return Val.ConstVal->getType();
402}
403
404MachineConstantPool::~MachineConstantPool() {
405  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
406    if (Constants[i].isMachineConstantPoolEntry())
407      delete Constants[i].Val.MachineCPVal;
408}
409
410/// getConstantPoolIndex - Create a new entry in the constant pool or return
411/// an existing one.  User must specify an alignment in bytes for the object.
412///
413unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
414                                                   unsigned Alignment) {
415  assert(Alignment && "Alignment must be specified!");
416  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
417
418  // Check to see if we already have this constant.
419  //
420  // FIXME, this could be made much more efficient for large constant pools.
421  unsigned AlignMask = (1 << Alignment)-1;
422  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
423    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
424      return i;
425
426  unsigned Offset = 0;
427  if (!Constants.empty()) {
428    Offset = Constants.back().getOffset();
429    Offset += TD->getTypeSize(Constants.back().getType());
430    Offset = (Offset+AlignMask)&~AlignMask;
431  }
432
433  Constants.push_back(MachineConstantPoolEntry(C, Offset));
434  return Constants.size()-1;
435}
436
437unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
438                                                   unsigned Alignment) {
439  assert(Alignment && "Alignment must be specified!");
440  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
441
442  // Check to see if we already have this constant.
443  //
444  // FIXME, this could be made much more efficient for large constant pools.
445  unsigned AlignMask = (1 << Alignment)-1;
446  int Idx = V->getExistingMachineCPValue(this, Alignment);
447  if (Idx != -1)
448    return (unsigned)Idx;
449
450  unsigned Offset = 0;
451  if (!Constants.empty()) {
452    Offset = Constants.back().getOffset();
453    Offset += TD->getTypeSize(Constants.back().getType());
454    Offset = (Offset+AlignMask)&~AlignMask;
455  }
456
457  Constants.push_back(MachineConstantPoolEntry(V, Offset));
458  return Constants.size()-1;
459}
460
461
462void MachineConstantPool::print(std::ostream &OS) const {
463  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
464    OS << "  <cp #" << i << "> is";
465    if (Constants[i].isMachineConstantPoolEntry())
466      Constants[i].Val.MachineCPVal->print(OS);
467    else
468      OS << *(Value*)Constants[i].Val.ConstVal;
469    OS << " , offset=" << Constants[i].getOffset();
470    OS << "\n";
471  }
472}
473
474void MachineConstantPool::dump() const { print(*cerr.stream()); }
475