MachineFunction.cpp revision bcd2498f4f1682dbdc41452add5b9bc72cbd6b3f 
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/TargetMachine.h"
25#include "llvm/Target/TargetFrameInfo.h"
26#include "llvm/Function.h"
27#include "llvm/Instructions.h"
28#include "llvm/Support/Compiler.h"
29#include "llvm/Support/GraphWriter.h"
30#include "llvm/Support/LeakDetector.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    std::ostream *OS;
46    const std::string Banner;
47
48    Printer (std::ostream *_OS, const std::string &_Banner) :
49      OS (_OS), Banner (_Banner) { }
50
51    const char *getPassName() const { return "MachineFunction Printer"; }
52
53    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
54      AU.setPreservesAll();
55    }
56
57    bool runOnMachineFunction(MachineFunction &MF) {
58      (*OS) << Banner;
59      MF.print (*OS);
60      return false;
61    }
62  };
63}
64
65/// Returns a newly-created MachineFunction Printer pass. The default output
66/// stream is std::cerr; the default banner is empty.
67///
68FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
69                                                     const std::string &Banner){
70  return new Printer(OS, Banner);
71}
72
73namespace {
74  struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
75    const char *getPassName() const { return "Machine Code Deleter"; }
76
77    bool runOnMachineFunction(MachineFunction &MF) {
78      // Delete the annotation from the function now.
79      MachineFunction::destruct(MF.getFunction());
80      return true;
81    }
82  };
83}
84
85/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
86/// the current function, which should happen after the function has been
87/// emitted to a .s file or to memory.
88FunctionPass *llvm::createMachineCodeDeleter() {
89  return new Deleter();
90}
91
92
93
94//===---------------------------------------------------------------------===//
95// MachineFunction implementation
96//===---------------------------------------------------------------------===//
97
98MachineBasicBlock* ilist_traits<MachineBasicBlock>::createSentinel() {
99  MachineBasicBlock* dummy = new MachineBasicBlock();
100  LeakDetector::removeGarbageObject(dummy);
101  return dummy;
102}
103
104void ilist_traits<MachineBasicBlock>::transferNodesFromList(
105  iplist<MachineBasicBlock, ilist_traits<MachineBasicBlock> >& toList,
106  ilist_iterator<MachineBasicBlock> first,
107  ilist_iterator<MachineBasicBlock> last) {
108  if (Parent != toList.Parent)
109    for (; first != last; ++first)
110      first->Parent = toList.Parent;
111}
112
113MachineFunction::MachineFunction(const Function *F,
114                                 const TargetMachine &TM)
115  : Annotation(MF_AID), Fn(F), Target(TM), UsedPhysRegs(0) {
116  SSARegMapping = new SSARegMap();
117  MFInfo = 0;
118  FrameInfo = new MachineFrameInfo();
119  ConstantPool = new MachineConstantPool(TM.getTargetData());
120  JumpTableInfo = new MachineJumpTableInfo(TM.getTargetData());
121  BasicBlocks.Parent = this;
122}
123
124MachineFunction::~MachineFunction() {
125  BasicBlocks.clear();
126  delete SSARegMapping;
127  delete MFInfo;
128  delete FrameInfo;
129  delete ConstantPool;
130  delete JumpTableInfo;
131  delete[] UsedPhysRegs;
132}
133
134
135/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
136/// recomputes them.  This guarantees that the MBB numbers are sequential,
137/// dense, and match the ordering of the blocks within the function.  If a
138/// specific MachineBasicBlock is specified, only that block and those after
139/// it are renumbered.
140void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
141  if (empty()) { MBBNumbering.clear(); return; }
142  MachineFunction::iterator MBBI, E = end();
143  if (MBB == 0)
144    MBBI = begin();
145  else
146    MBBI = MBB;
147
148  // Figure out the block number this should have.
149  unsigned BlockNo = 0;
150  if (MBBI != begin())
151    BlockNo = prior(MBBI)->getNumber()+1;
152
153  for (; MBBI != E; ++MBBI, ++BlockNo) {
154    if (MBBI->getNumber() != (int)BlockNo) {
155      // Remove use of the old number.
156      if (MBBI->getNumber() != -1) {
157        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
158               "MBB number mismatch!");
159        MBBNumbering[MBBI->getNumber()] = 0;
160      }
161
162      // If BlockNo is already taken, set that block's number to -1.
163      if (MBBNumbering[BlockNo])
164        MBBNumbering[BlockNo]->setNumber(-1);
165
166      MBBNumbering[BlockNo] = MBBI;
167      MBBI->setNumber(BlockNo);
168    }
169  }
170
171  // Okay, all the blocks are renumbered.  If we have compactified the block
172  // numbering, shrink MBBNumbering now.
173  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
174  MBBNumbering.resize(BlockNo);
175}
176
177
178void MachineFunction::dump() const { print(*cerr.stream()); }
179
180void MachineFunction::print(std::ostream &OS) const {
181  OS << "# Machine code for " << Fn->getName () << "():\n";
182
183  // Print Frame Information
184  getFrameInfo()->print(*this, OS);
185
186  // Print JumpTable Information
187  getJumpTableInfo()->print(OS);
188
189  // Print Constant Pool
190  getConstantPool()->print(OS);
191
192  const MRegisterInfo *MRI = getTarget().getRegisterInfo();
193
194  if (livein_begin() != livein_end()) {
195    OS << "Live Ins:";
196    for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I) {
197      if (MRI)
198        OS << " " << MRI->getName(I->first);
199      else
200        OS << " Reg #" << I->first;
201
202      if (I->second)
203        OS << " in VR#" << I->second << " ";
204    }
205    OS << "\n";
206  }
207  if (liveout_begin() != liveout_end()) {
208    OS << "Live Outs:";
209    for (liveout_iterator I = liveout_begin(), E = liveout_end(); I != E; ++I)
210      if (MRI)
211        OS << " " << MRI->getName(*I);
212      else
213        OS << " Reg #" << *I;
214    OS << "\n";
215  }
216
217  for (const_iterator BB = begin(); BB != end(); ++BB)
218    BB->print(OS);
219
220  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
221}
222
223/// CFGOnly flag - This is used to control whether or not the CFG graph printer
224/// prints out the contents of basic blocks or not.  This is acceptable because
225/// this code is only really used for debugging purposes.
226///
227static bool CFGOnly = false;
228
229namespace llvm {
230  template<>
231  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
232    static std::string getGraphName(const MachineFunction *F) {
233      return "CFG for '" + F->getFunction()->getName() + "' function";
234    }
235
236    static std::string getNodeLabel(const MachineBasicBlock *Node,
237                                    const MachineFunction *Graph) {
238      if (CFGOnly && Node->getBasicBlock() &&
239          !Node->getBasicBlock()->getName().empty())
240        return Node->getBasicBlock()->getName() + ":";
241
242      std::ostringstream Out;
243      if (CFGOnly) {
244        Out << Node->getNumber() << ':';
245        return Out.str();
246      }
247
248      Node->print(Out);
249
250      std::string OutStr = Out.str();
251      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
252
253      // Process string output to make it nicer...
254      for (unsigned i = 0; i != OutStr.length(); ++i)
255        if (OutStr[i] == '\n') {                            // Left justify
256          OutStr[i] = '\\';
257          OutStr.insert(OutStr.begin()+i+1, 'l');
258        }
259      return OutStr;
260    }
261  };
262}
263
264void MachineFunction::viewCFG() const
265{
266#ifndef NDEBUG
267  ViewGraph(this, "mf" + getFunction()->getName());
268#else
269  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
270       << "systems with Graphviz or gv!\n";
271#endif // NDEBUG
272}
273
274void MachineFunction::viewCFGOnly() const
275{
276  CFGOnly = true;
277  viewCFG();
278  CFGOnly = false;
279}
280
281// The next two methods are used to construct and to retrieve
282// the MachineCodeForFunction object for the given function.
283// construct() -- Allocates and initializes for a given function and target
284// get()       -- Returns a handle to the object.
285//                This should not be called before "construct()"
286//                for a given Function.
287//
288MachineFunction&
289MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
290{
291  assert(Fn->getAnnotation(MF_AID) == 0 &&
292         "Object already exists for this function!");
293  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
294  Fn->addAnnotation(mcInfo);
295  return *mcInfo;
296}
297
298void MachineFunction::destruct(const Function *Fn) {
299  bool Deleted = Fn->deleteAnnotation(MF_AID);
300  assert(Deleted && "Machine code did not exist for function!");
301}
302
303MachineFunction& MachineFunction::get(const Function *F)
304{
305  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
306  assert(mc && "Call construct() method first to allocate the object");
307  return *mc;
308}
309
310void MachineFunction::clearSSARegMap() {
311  delete SSARegMapping;
312  SSARegMapping = 0;
313}
314
315//===----------------------------------------------------------------------===//
316//  MachineFrameInfo implementation
317//===----------------------------------------------------------------------===//
318
319void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
320  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
321
322  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
323    const StackObject &SO = Objects[i];
324    OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
325    if (SO.Size == 0)
326      OS << "variable sized";
327    else
328      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
329    OS << " alignment is " << SO.Alignment << " byte"
330       << (SO.Alignment != 1 ? "s," : ",");
331
332    if (i < NumFixedObjects)
333      OS << " fixed";
334    if (i < NumFixedObjects || SO.SPOffset != -1) {
335      int Off = SO.SPOffset - ValOffset;
336      OS << " at location [SP";
337      if (Off > 0)
338        OS << "+" << Off;
339      else if (Off < 0)
340        OS << Off;
341      OS << "]";
342    }
343    OS << "\n";
344  }
345
346  if (HasVarSizedObjects)
347    OS << "  Stack frame contains variable sized objects\n";
348}
349
350void MachineFrameInfo::dump(const MachineFunction &MF) const {
351  print(MF, *cerr.stream());
352}
353
354
355//===----------------------------------------------------------------------===//
356//  MachineJumpTableInfo implementation
357//===----------------------------------------------------------------------===//
358
359/// getJumpTableIndex - Create a new jump table entry in the jump table info
360/// or return an existing one.
361///
362unsigned MachineJumpTableInfo::getJumpTableIndex(
363                               const std::vector<MachineBasicBlock*> &DestBBs) {
364  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
365  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
366    if (JumpTables[i].MBBs == DestBBs)
367      return i;
368
369  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
370  return JumpTables.size()-1;
371}
372
373
374void MachineJumpTableInfo::print(std::ostream &OS) const {
375  // FIXME: this is lame, maybe we could print out the MBB numbers or something
376  // like {1, 2, 4, 5, 3, 0}
377  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
378    OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size()
379       << " entries\n";
380  }
381}
382
383unsigned MachineJumpTableInfo::getEntrySize() const {
384  return TD->getPointerSize();
385}
386
387unsigned MachineJumpTableInfo::getAlignment() const {
388  return TD->getPointerAlignment();
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].Offset;
470    OS << "\n";
471  }
472}
473
474void MachineConstantPool::dump() const { print(*cerr.stream()); }
475