MachineFunction.cpp revision 4b9a4006748b8d72a04504a5fc1f5daa73bf69f9 
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/MachineFunctionInfo.h"
20#include "llvm/CodeGen/MachineFrameInfo.h"
21#include "llvm/CodeGen/MachineConstantPool.h"
22#include "llvm/CodeGen/Passes.h"
23#include "llvm/Target/TargetMachine.h"
24#include "llvm/Target/TargetFrameInfo.h"
25#include "llvm/Function.h"
26#include "llvm/iOther.h"
27#include "llvm/Type.h"
28#include "Support/LeakDetector.h"
29
30using namespace llvm;
31
32static AnnotationID MF_AID(
33                 AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
34
35
36namespace {
37  struct Printer : public MachineFunctionPass {
38    std::ostream *OS;
39    const std::string Banner;
40
41    Printer (std::ostream *_OS, const std::string &_Banner) :
42      OS (_OS), Banner (_Banner) { }
43
44    const char *getPassName() const { return "MachineFunction Printer"; }
45
46    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
47      AU.setPreservesAll();
48    }
49
50    bool runOnMachineFunction(MachineFunction &MF) {
51      (*OS) << Banner;
52      MF.print (*OS);
53      return false;
54    }
55  };
56}
57
58/// Returns a newly-created MachineFunction Printer pass. The default output
59/// stream is std::cerr; the default banner is empty.
60///
61FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
62                                                     const std::string &Banner) {
63  return new Printer(OS, Banner);
64}
65
66namespace {
67  struct Deleter : public MachineFunctionPass {
68    const char *getPassName() const { return "Machine Code Deleter"; }
69
70    bool runOnMachineFunction(MachineFunction &MF) {
71      // Delete the annotation from the function now.
72      MachineFunction::destruct(MF.getFunction());
73      return true;
74    }
75  };
76}
77
78/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
79/// the current function, which should happen after the function has been
80/// emitted to a .s file or to memory.
81FunctionPass *llvm::createMachineCodeDeleter() {
82  return new Deleter();
83}
84
85
86
87//===---------------------------------------------------------------------===//
88// MachineFunction implementation
89//===---------------------------------------------------------------------===//
90MachineBasicBlock* ilist_traits<MachineBasicBlock>::createNode()
91{
92    MachineBasicBlock* dummy = new MachineBasicBlock();
93    LeakDetector::removeGarbageObject(dummy);
94    return dummy;
95}
96
97void ilist_traits<MachineBasicBlock>::transferNodesFromList(
98    iplist<MachineBasicBlock, ilist_traits<MachineBasicBlock> >& toList,
99    ilist_iterator<MachineBasicBlock> first,
100    ilist_iterator<MachineBasicBlock> last)
101{
102    if (Parent != toList.Parent)
103        for (; first != last; ++first)
104            first->Parent = toList.Parent;
105}
106
107MachineFunction::MachineFunction(const Function *F,
108                                 const TargetMachine &TM)
109  : Annotation(MF_AID), Fn(F), Target(TM) {
110  SSARegMapping = new SSARegMap();
111  MFInfo = new MachineFunctionInfo(*this);
112  FrameInfo = new MachineFrameInfo();
113  ConstantPool = new MachineConstantPool();
114  BasicBlocks.Parent = this;
115}
116
117MachineFunction::~MachineFunction() {
118  BasicBlocks.clear();
119  delete SSARegMapping;
120  delete MFInfo;
121  delete FrameInfo;
122  delete ConstantPool;
123}
124
125void MachineFunction::dump() const { print(std::cerr); }
126
127void MachineFunction::print(std::ostream &OS) const {
128  OS << "# Machine code for " << Fn->getName () << "():\n";
129
130  // Print Frame Information
131  getFrameInfo()->print(*this, OS);
132
133  // Print Constant Pool
134  getConstantPool()->print(OS);
135
136  for (const_iterator BB = begin(); BB != end(); ++BB)
137    BB->print(OS);
138
139  OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
140}
141
142// The next two methods are used to construct and to retrieve
143// the MachineCodeForFunction object for the given function.
144// construct() -- Allocates and initializes for a given function and target
145// get()       -- Returns a handle to the object.
146//                This should not be called before "construct()"
147//                for a given Function.
148//
149MachineFunction&
150MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
151{
152  assert(Fn->getAnnotation(MF_AID) == 0 &&
153         "Object already exists for this function!");
154  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
155  Fn->addAnnotation(mcInfo);
156  return *mcInfo;
157}
158
159void MachineFunction::destruct(const Function *Fn) {
160  bool Deleted = Fn->deleteAnnotation(MF_AID);
161  assert(Deleted && "Machine code did not exist for function!");
162}
163
164MachineFunction& MachineFunction::get(const Function *F)
165{
166  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
167  assert(mc && "Call construct() method first to allocate the object");
168  return *mc;
169}
170
171void MachineFunction::clearSSARegMap() {
172  delete SSARegMapping;
173  SSARegMapping = 0;
174}
175
176//===----------------------------------------------------------------------===//
177//  MachineFrameInfo implementation
178//===----------------------------------------------------------------------===//
179
180/// CreateStackObject - Create a stack object for a value of the specified type.
181///
182int MachineFrameInfo::CreateStackObject(const Type *Ty, const TargetData &TD) {
183  return CreateStackObject(TD.getTypeSize(Ty), TD.getTypeAlignment(Ty));
184}
185
186int MachineFrameInfo::CreateStackObject(const TargetRegisterClass *RC) {
187  return CreateStackObject(RC->getSize(), RC->getAlignment());
188}
189
190
191void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
192  int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
193
194  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
195    const StackObject &SO = Objects[i];
196    OS << "  <fi #" << (int)(i-NumFixedObjects) << "> is ";
197    if (SO.Size == 0)
198      OS << "variable sized";
199    else
200      OS << SO.Size << " byte" << (SO.Size != 1 ? "s" : " ");
201
202    if (i < NumFixedObjects)
203      OS << " fixed";
204    if (i < NumFixedObjects || SO.SPOffset != -1) {
205      int Off = SO.SPOffset - ValOffset;
206      OS << " at location [SP";
207      if (Off > 0)
208	OS << "+" << Off;
209      else if (Off < 0)
210	OS << Off;
211      OS << "]";
212    }
213    OS << "\n";
214  }
215
216  if (HasVarSizedObjects)
217    OS << "  Stack frame contains variable sized objects\n";
218}
219
220void MachineFrameInfo::dump(const MachineFunction &MF) const {
221  print(MF, std::cerr);
222}
223
224
225//===----------------------------------------------------------------------===//
226//  MachineConstantPool implementation
227//===----------------------------------------------------------------------===//
228
229void MachineConstantPool::print(std::ostream &OS) const {
230  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
231    OS << "  <cp #" << i << "> is" << *(Value*)Constants[i] << "\n";
232}
233
234void MachineConstantPool::dump() const { print(std::cerr); }
235
236//===----------------------------------------------------------------------===//
237//  MachineFunctionInfo implementation
238//===----------------------------------------------------------------------===//
239
240static unsigned
241ComputeMaxOptionalArgsSize(const TargetMachine& target, const Function *F,
242                           unsigned &maxOptionalNumArgs)
243{
244  const TargetFrameInfo &frameInfo = *target.getFrameInfo();
245
246  unsigned maxSize = 0;
247
248  for (Function::const_iterator BB = F->begin(), BBE = F->end(); BB !=BBE; ++BB)
249    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
250      if (const CallInst *callInst = dyn_cast<CallInst>(I))
251        {
252          unsigned numOperands = callInst->getNumOperands() - 1;
253          int numExtra = (int)numOperands-frameInfo.getNumFixedOutgoingArgs();
254          if (numExtra <= 0)
255            continue;
256
257          unsigned sizeForThisCall;
258          if (frameInfo.argsOnStackHaveFixedSize())
259            {
260              int argSize = frameInfo.getSizeOfEachArgOnStack();
261              sizeForThisCall = numExtra * (unsigned) argSize;
262            }
263          else
264            {
265              assert(0 && "UNTESTED CODE: Size per stack argument is not "
266                     "fixed on this architecture: use actual arg sizes to "
267                     "compute MaxOptionalArgsSize");
268              sizeForThisCall = 0;
269              for (unsigned i = 0; i < numOperands; ++i)
270                sizeForThisCall += target.getTargetData().getTypeSize(callInst->
271                                              getOperand(i)->getType());
272            }
273
274          if (maxSize < sizeForThisCall)
275            maxSize = sizeForThisCall;
276
277          if ((int)maxOptionalNumArgs < numExtra)
278            maxOptionalNumArgs = (unsigned) numExtra;
279        }
280
281  return maxSize;
282}
283
284// Align data larger than one L1 cache line on L1 cache line boundaries.
285// Align all smaller data on the next higher 2^x boundary (4, 8, ...),
286// but not higher than the alignment of the largest type we support
287// (currently a double word). -- see class TargetData).
288//
289// This function is similar to the corresponding function in EmitAssembly.cpp
290// but they are unrelated.  This one does not align at more than a
291// double-word boundary whereas that one might.
292//
293inline unsigned
294SizeToAlignment(unsigned size, const TargetMachine& target)
295{
296  const unsigned short cacheLineSize = 16;
297  if (size > (unsigned) cacheLineSize / 2)
298    return cacheLineSize;
299  else
300    for (unsigned sz=1; /*no condition*/; sz *= 2)
301      if (sz >= size || sz >= target.getTargetData().getDoubleAlignment())
302        return sz;
303}
304
305
306void MachineFunctionInfo::CalculateArgSize() {
307  maxOptionalArgsSize = ComputeMaxOptionalArgsSize(MF.getTarget(),
308						   MF.getFunction(),
309                                                   maxOptionalNumArgs);
310  staticStackSize = maxOptionalArgsSize
311    + MF.getTarget().getFrameInfo()->getMinStackFrameSize();
312}
313
314int
315MachineFunctionInfo::computeOffsetforLocalVar(const Value* val,
316					      unsigned &getPaddedSize,
317					      unsigned  sizeToUse)
318{
319  if (sizeToUse == 0) {
320    // All integer types smaller than ints promote to 4 byte integers.
321    if (val->getType()->isIntegral() && val->getType()->getPrimitiveSize() < 4)
322      sizeToUse = 4;
323    else
324      sizeToUse = MF.getTarget().getTargetData().getTypeSize(val->getType());
325  }
326  unsigned align = SizeToAlignment(sizeToUse, MF.getTarget());
327
328  bool growUp;
329  int firstOffset = MF.getTarget().getFrameInfo()->getFirstAutomaticVarOffset(MF,
330						 			     growUp);
331  int offset = growUp? firstOffset + getAutomaticVarsSize()
332                     : firstOffset - (getAutomaticVarsSize() + sizeToUse);
333
334  int aligned = MF.getTarget().getFrameInfo()->adjustAlignment(offset, growUp, align);
335  getPaddedSize = sizeToUse + abs(aligned - offset);
336
337  return aligned;
338}
339
340
341int MachineFunctionInfo::allocateLocalVar(const Value* val,
342                                          unsigned sizeToUse) {
343  assert(! automaticVarsAreaFrozen &&
344         "Size of auto vars area has been used to compute an offset so "
345         "no more automatic vars should be allocated!");
346
347  // Check if we've allocated a stack slot for this value already
348  //
349  hash_map<const Value*, int>::const_iterator pair = offsets.find(val);
350  if (pair != offsets.end())
351    return pair->second;
352
353  unsigned getPaddedSize;
354  unsigned offset = computeOffsetforLocalVar(val, getPaddedSize, sizeToUse);
355  offsets[val] = offset;
356  incrementAutomaticVarsSize(getPaddedSize);
357  return offset;
358}
359
360int
361MachineFunctionInfo::allocateSpilledValue(const Type* type)
362{
363  assert(! spillsAreaFrozen &&
364         "Size of reg spills area has been used to compute an offset so "
365         "no more register spill slots should be allocated!");
366
367  unsigned size  = MF.getTarget().getTargetData().getTypeSize(type);
368  unsigned char align = MF.getTarget().getTargetData().getTypeAlignment(type);
369
370  bool growUp;
371  int firstOffset = MF.getTarget().getFrameInfo()->getRegSpillAreaOffset(MF, growUp);
372
373  int offset = growUp? firstOffset + getRegSpillsSize()
374                     : firstOffset - (getRegSpillsSize() + size);
375
376  int aligned = MF.getTarget().getFrameInfo()->adjustAlignment(offset, growUp, align);
377  size += abs(aligned - offset); // include alignment padding in size
378
379  incrementRegSpillsSize(size);  // update size of reg. spills area
380
381  return aligned;
382}
383
384int
385MachineFunctionInfo::pushTempValue(unsigned size)
386{
387  unsigned align = SizeToAlignment(size, MF.getTarget());
388
389  bool growUp;
390  int firstOffset = MF.getTarget().getFrameInfo()->getTmpAreaOffset(MF, growUp);
391
392  int offset = growUp? firstOffset + currentTmpValuesSize
393                     : firstOffset - (currentTmpValuesSize + size);
394
395  int aligned = MF.getTarget().getFrameInfo()->adjustAlignment(offset, growUp,
396							      align);
397  size += abs(aligned - offset); // include alignment padding in size
398
399  incrementTmpAreaSize(size);    // update "current" size of tmp area
400
401  return aligned;
402}
403
404void MachineFunctionInfo::popAllTempValues() {
405  resetTmpAreaSize();            // clear tmp area to reuse
406}
407
408