MachineFunction.cpp revision 74ab84c31ef64538a1b56e1f282e49303412ad17 
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/TargetLowering.h"
26#include "llvm/Target/TargetMachine.h"
27#include "llvm/Target/TargetFrameInfo.h"
28#include "llvm/Function.h"
29#include "llvm/Instructions.h"
30#include "llvm/Support/Compiler.h"
31#include "llvm/Support/GraphWriter.h"
32#include "llvm/Support/LeakDetector.h"
33#include "llvm/ADT/STLExtras.h"
34#include "llvm/Config/config.h"
35#include <fstream>
36#include <sstream>
37using namespace llvm;
38
39static AnnotationID MF_AID(
40  AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
41
42// Out of line virtual function to home classes.
43void MachineFunctionPass::virtfn() {}
44
45namespace {
46  struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
47    static char ID;
48
49    std::ostream *OS;
50    const std::string Banner;
51
52    Printer (std::ostream *_OS, const std::string &_Banner)
53      : MachineFunctionPass((intptr_t)&ID), OS (_OS), Banner (_Banner) { }
54
55    const char *getPassName() const { return "MachineFunction Printer"; }
56
57    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
58      AU.setPreservesAll();
59    }
60
61    bool runOnMachineFunction(MachineFunction &MF) {
62      (*OS) << Banner;
63      MF.print (*OS);
64      return false;
65    }
66  };
67  char Printer::ID = 0;
68}
69
70/// Returns a newly-created MachineFunction Printer pass. The default output
71/// stream is std::cerr; the default banner is empty.
72///
73FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
74                                                     const std::string &Banner){
75  return new Printer(OS, Banner);
76}
77
78namespace {
79  struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
80    static char ID;
81    Deleter() : MachineFunctionPass((intptr_t)&ID) {}
82
83    const char *getPassName() const { return "Machine Code Deleter"; }
84
85    bool runOnMachineFunction(MachineFunction &MF) {
86      // Delete the annotation from the function now.
87      MachineFunction::destruct(MF.getFunction());
88      return true;
89    }
90  };
91  char Deleter::ID = 0;
92}
93
94/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
95/// the current function, which should happen after the function has been
96/// emitted to a .s file or to memory.
97FunctionPass *llvm::createMachineCodeDeleter() {
98  return new Deleter();
99}
100
101
102
103//===---------------------------------------------------------------------===//
104// MachineFunction implementation
105//===---------------------------------------------------------------------===//
106
107MachineBasicBlock* ilist_traits<MachineBasicBlock>::createSentinel() {
108  MachineBasicBlock* dummy = new MachineBasicBlock();
109  LeakDetector::removeGarbageObject(dummy);
110  return dummy;
111}
112
113void ilist_traits<MachineBasicBlock>::transferNodesFromList(
114            iplist<MachineBasicBlock, ilist_traits<MachineBasicBlock> >& toList,
115            ilist_iterator<MachineBasicBlock> first,
116            ilist_iterator<MachineBasicBlock> last) {
117  // If splicing withing the same function, no change.
118  if (Parent == toList.Parent) return;
119
120  for (; first != last; ++first)
121    first->setParent(toList.Parent);
122}
123
124MachineFunction::MachineFunction(const Function *F,
125                                 const TargetMachine &TM)
126  : Annotation(MF_AID), Fn(F), Target(TM) {
127  RegInfo = new MachineRegisterInfo(*TM.getRegisterInfo());
128  MFInfo = 0;
129  FrameInfo = new MachineFrameInfo(*TM.getFrameInfo());
130  ConstantPool = new MachineConstantPool(TM.getTargetData());
131
132  // Set up jump table.
133  const TargetData &TD = *TM.getTargetData();
134  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
135  unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
136  unsigned Alignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
137                             : TD.getPointerABIAlignment();
138  JumpTableInfo = new MachineJumpTableInfo(EntrySize, Alignment);
139
140  BasicBlocks.Parent = this;
141}
142
143MachineFunction::~MachineFunction() {
144  BasicBlocks.clear();
145  delete RegInfo;
146  delete MFInfo;
147  delete FrameInfo;
148  delete ConstantPool;
149  delete JumpTableInfo;
150}
151
152
153/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
154/// recomputes them.  This guarantees that the MBB numbers are sequential,
155/// dense, and match the ordering of the blocks within the function.  If a
156/// specific MachineBasicBlock is specified, only that block and those after
157/// it are renumbered.
158void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
159  if (empty()) { MBBNumbering.clear(); return; }
160  MachineFunction::iterator MBBI, E = end();
161  if (MBB == 0)
162    MBBI = begin();
163  else
164    MBBI = MBB;
165
166  // Figure out the block number this should have.
167  unsigned BlockNo = 0;
168  if (MBBI != begin())
169    BlockNo = prior(MBBI)->getNumber()+1;
170
171  for (; MBBI != E; ++MBBI, ++BlockNo) {
172    if (MBBI->getNumber() != (int)BlockNo) {
173      // Remove use of the old number.
174      if (MBBI->getNumber() != -1) {
175        assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
176               "MBB number mismatch!");
177        MBBNumbering[MBBI->getNumber()] = 0;
178      }
179
180      // If BlockNo is already taken, set that block's number to -1.
181      if (MBBNumbering[BlockNo])
182        MBBNumbering[BlockNo]->setNumber(-1);
183
184      MBBNumbering[BlockNo] = MBBI;
185      MBBI->setNumber(BlockNo);
186    }
187  }
188
189  // Okay, all the blocks are renumbered.  If we have compactified the block
190  // numbering, shrink MBBNumbering now.
191  assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
192  MBBNumbering.resize(BlockNo);
193}
194
195
196void MachineFunction::dump() const { print(*cerr.stream()); }
197
198void MachineFunction::print(std::ostream &OS) const {
199  OS << "# Machine code for " << Fn->getName () << "():\n";
200
201  // Print Frame Information
202  getFrameInfo()->print(*this, OS);
203
204  // Print JumpTable Information
205  getJumpTableInfo()->print(OS);
206
207  // Print Constant Pool
208  getConstantPool()->print(OS);
209
210  const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
211
212  if (!RegInfo->livein_empty()) {
213    OS << "Live Ins:";
214    for (MachineRegisterInfo::livein_iterator
215         I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
216      if (TRI)
217        OS << " " << TRI->getPrintableName(I->first);
218      else
219        OS << " Reg #" << I->first;
220
221      if (I->second)
222        OS << " in VR#" << I->second << " ";
223    }
224    OS << "\n";
225  }
226  if (!RegInfo->liveout_empty()) {
227    OS << "Live Outs:";
228    for (MachineRegisterInfo::liveout_iterator
229         I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
230      if (TRI)
231        OS << " " << TRI->getPrintableName(*I);
232      else
233        OS << " Reg #" << *I;
234    OS << "\n";
235  }
236
237  for (const_iterator BB = begin(); BB != end(); ++BB)
238    BB->print(OS);
239
240  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
241}
242
243/// CFGOnly flag - This is used to control whether or not the CFG graph printer
244/// prints out the contents of basic blocks or not.  This is acceptable because
245/// this code is only really used for debugging purposes.
246///
247static bool CFGOnly = false;
248
249namespace llvm {
250  template<>
251  struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
252    static std::string getGraphName(const MachineFunction *F) {
253      return "CFG for '" + F->getFunction()->getName() + "' function";
254    }
255
256    static std::string getNodeLabel(const MachineBasicBlock *Node,
257                                    const MachineFunction *Graph) {
258      if (CFGOnly && Node->getBasicBlock() &&
259          !Node->getBasicBlock()->getName().empty())
260        return Node->getBasicBlock()->getName() + ":";
261
262      std::ostringstream Out;
263      if (CFGOnly) {
264        Out << Node->getNumber() << ':';
265        return Out.str();
266      }
267
268      Node->print(Out);
269
270      std::string OutStr = Out.str();
271      if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
272
273      // Process string output to make it nicer...
274      for (unsigned i = 0; i != OutStr.length(); ++i)
275        if (OutStr[i] == '\n') {                            // Left justify
276          OutStr[i] = '\\';
277          OutStr.insert(OutStr.begin()+i+1, 'l');
278        }
279      return OutStr;
280    }
281  };
282}
283
284void MachineFunction::viewCFG() const
285{
286#ifndef NDEBUG
287  ViewGraph(this, "mf" + getFunction()->getName());
288#else
289  cerr << "SelectionDAG::viewGraph is only available in debug builds on "
290       << "systems with Graphviz or gv!\n";
291#endif // NDEBUG
292}
293
294void MachineFunction::viewCFGOnly() const
295{
296  CFGOnly = true;
297  viewCFG();
298  CFGOnly = false;
299}
300
301// The next two methods are used to construct and to retrieve
302// the MachineCodeForFunction object for the given function.
303// construct() -- Allocates and initializes for a given function and target
304// get()       -- Returns a handle to the object.
305//                This should not be called before "construct()"
306//                for a given Function.
307//
308MachineFunction&
309MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
310{
311  assert(Fn->getAnnotation(MF_AID) == 0 &&
312         "Object already exists for this function!");
313  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
314  Fn->addAnnotation(mcInfo);
315  return *mcInfo;
316}
317
318void MachineFunction::destruct(const Function *Fn) {
319  bool Deleted = Fn->deleteAnnotation(MF_AID);
320  assert(Deleted && "Machine code did not exist for function!");
321}
322
323MachineFunction& MachineFunction::get(const Function *F)
324{
325  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
326  assert(mc && "Call construct() method first to allocate the object");
327  return *mc;
328}
329
330//===----------------------------------------------------------------------===//
331//  MachineFrameInfo implementation
332//===----------------------------------------------------------------------===//
333
334/// CreateFixedObject - Create a new object at a fixed location on the stack.
335/// All fixed objects should be created before other objects are created for
336/// efficiency. By default, fixed objects are immutable. This returns an
337/// index with a negative value.
338///
339int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
340                                        bool Immutable) {
341  assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
342  Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
343  return -++NumFixedObjects;
344}
345
346
347void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
348  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
349
350  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
351    const StackObject &SO = Objects[i];
352    OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
353    if (SO.Size == 0)
354      OS << "variable sized";
355    else
356      OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
357    OS << " alignment is " << SO.Alignment << " byte"
358       << (SO.Alignment != 1 ? "s," : ",");
359
360    if (i < NumFixedObjects)
361      OS << " fixed";
362    if (i < NumFixedObjects || SO.SPOffset != -1) {
363      int64_t Off = SO.SPOffset - ValOffset;
364      OS << " at location [SP";
365      if (Off > 0)
366        OS << "+" << Off;
367      else if (Off < 0)
368        OS << Off;
369      OS << "]";
370    }
371    OS << "\n";
372  }
373
374  if (HasVarSizedObjects)
375    OS << "  Stack frame contains variable sized objects\n";
376}
377
378void MachineFrameInfo::dump(const MachineFunction &MF) const {
379  print(MF, *cerr.stream());
380}
381
382
383//===----------------------------------------------------------------------===//
384//  MachineJumpTableInfo implementation
385//===----------------------------------------------------------------------===//
386
387/// getJumpTableIndex - Create a new jump table entry in the jump table info
388/// or return an existing one.
389///
390unsigned MachineJumpTableInfo::getJumpTableIndex(
391                               const std::vector<MachineBasicBlock*> &DestBBs) {
392  assert(!DestBBs.empty() && "Cannot create an empty jump table!");
393  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
394    if (JumpTables[i].MBBs == DestBBs)
395      return i;
396
397  JumpTables.push_back(MachineJumpTableEntry(DestBBs));
398  return JumpTables.size()-1;
399}
400
401
402void MachineJumpTableInfo::print(std::ostream &OS) const {
403  // FIXME: this is lame, maybe we could print out the MBB numbers or something
404  // like {1, 2, 4, 5, 3, 0}
405  for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
406    OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size()
407       << " entries\n";
408  }
409}
410
411void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
412
413
414//===----------------------------------------------------------------------===//
415//  MachineConstantPool implementation
416//===----------------------------------------------------------------------===//
417
418const Type *MachineConstantPoolEntry::getType() const {
419  if (isMachineConstantPoolEntry())
420      return Val.MachineCPVal->getType();
421  return Val.ConstVal->getType();
422}
423
424MachineConstantPool::~MachineConstantPool() {
425  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
426    if (Constants[i].isMachineConstantPoolEntry())
427      delete Constants[i].Val.MachineCPVal;
428}
429
430/// getConstantPoolIndex - Create a new entry in the constant pool or return
431/// an existing one.  User must specify an alignment in bytes for the object.
432///
433unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
434                                                   unsigned Alignment) {
435  assert(Alignment && "Alignment must be specified!");
436  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
437
438  // Check to see if we already have this constant.
439  //
440  // FIXME, this could be made much more efficient for large constant pools.
441  unsigned AlignMask = (1 << Alignment)-1;
442  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
443    if (Constants[i].Val.ConstVal == C && (Constants[i].Offset & AlignMask)== 0)
444      return i;
445
446  unsigned Offset = 0;
447  if (!Constants.empty()) {
448    Offset = Constants.back().getOffset();
449    Offset += TD->getABITypeSize(Constants.back().getType());
450    Offset = (Offset+AlignMask)&~AlignMask;
451  }
452
453  Constants.push_back(MachineConstantPoolEntry(C, Offset));
454  return Constants.size()-1;
455}
456
457unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
458                                                   unsigned Alignment) {
459  assert(Alignment && "Alignment must be specified!");
460  if (Alignment > PoolAlignment) PoolAlignment = Alignment;
461
462  // Check to see if we already have this constant.
463  //
464  // FIXME, this could be made much more efficient for large constant pools.
465  unsigned AlignMask = (1 << Alignment)-1;
466  int Idx = V->getExistingMachineCPValue(this, Alignment);
467  if (Idx != -1)
468    return (unsigned)Idx;
469
470  unsigned Offset = 0;
471  if (!Constants.empty()) {
472    Offset = Constants.back().getOffset();
473    Offset += TD->getABITypeSize(Constants.back().getType());
474    Offset = (Offset+AlignMask)&~AlignMask;
475  }
476
477  Constants.push_back(MachineConstantPoolEntry(V, Offset));
478  return Constants.size()-1;
479}
480
481
482void MachineConstantPool::print(std::ostream &OS) const {
483  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
484    OS << "  <cp #" << i << "> is";
485    if (Constants[i].isMachineConstantPoolEntry())
486      Constants[i].Val.MachineCPVal->print(OS);
487    else
488      OS << *(Value*)Constants[i].Val.ConstVal;
489    OS << " , offset=" << Constants[i].getOffset();
490    OS << "\n";
491  }
492}
493
494void MachineConstantPool::dump() const { print(*cerr.stream()); }
495