MachineFunction.cpp revision c81efdc59cd2ce5410cefd7ab5cb52cfd7ac3aad 
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/MachineCodeForInstruction.h"
19#include "llvm/CodeGen/SSARegMap.h"
20#include "llvm/CodeGen/MachineFunctionInfo.h"
21#include "llvm/CodeGen/MachineFrameInfo.h"
22#include "llvm/CodeGen/MachineConstantPool.h"
23#include "llvm/CodeGen/Passes.h"
24#include "llvm/Target/TargetMachine.h"
25#include "llvm/Target/TargetFrameInfo.h"
26#include "llvm/Target/TargetCacheInfo.h"
27#include "llvm/Function.h"
28#include "llvm/iOther.h"
29using namespace llvm;
30
31static AnnotationID MF_AID(
32                 AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
33
34
35namespace {
36  struct Printer : public MachineFunctionPass {
37    std::ostream *OS;
38    const std::string Banner;
39
40    Printer (std::ostream *_OS, const std::string &_Banner) :
41      OS (_OS), Banner (_Banner) { }
42
43    const char *getPassName() const { return "MachineFunction Printer"; }
44
45    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
46      AU.setPreservesAll();
47    }
48
49    bool runOnMachineFunction(MachineFunction &MF) {
50      (*OS) << Banner;
51      MF.print (*OS);
52      return false;
53    }
54  };
55}
56
57/// Returns a newly-created MachineFunction Printer pass. The default output
58/// stream is std::cerr; the default banner is empty.
59///
60FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
61                                                     const std::string &Banner) {
62  return new Printer(OS, Banner);
63}
64
65namespace {
66  struct Deleter : public MachineFunctionPass {
67    const char *getPassName() const { return "Machine Code Deleter"; }
68
69    bool runOnMachineFunction(MachineFunction &MF) {
70      // Delete the annotation from the function now.
71      MachineFunction::destruct(MF.getFunction());
72      return true;
73    }
74  };
75}
76
77/// MachineCodeDeletion Pass - This pass deletes all of the machine code for
78/// the current function, which should happen after the function has been
79/// emitted to a .s file or to memory.
80FunctionPass *llvm::createMachineCodeDeleter() {
81  return new Deleter();
82}
83
84
85
86//===---------------------------------------------------------------------===//
87// MachineFunction implementation
88//===---------------------------------------------------------------------===//
89
90MachineFunction::MachineFunction(const Function *F,
91                                 const TargetMachine &TM)
92  : Annotation(MF_AID), Fn(F), Target(TM) {
93  SSARegMapping = new SSARegMap();
94  MFInfo = new MachineFunctionInfo(*this);
95  FrameInfo = new MachineFrameInfo();
96  ConstantPool = new MachineConstantPool();
97}
98
99MachineFunction::~MachineFunction() {
100  delete SSARegMapping;
101  delete MFInfo;
102  delete FrameInfo;
103  delete ConstantPool;
104}
105
106void MachineFunction::dump() const { print(std::cerr); }
107
108void MachineFunction::print(std::ostream &OS) const {
109  OS << "\n" << *(Value*)Fn->getFunctionType() << " \"" << Fn->getName()
110     << "\"\n";
111
112  // Print Frame Information
113  getFrameInfo()->print(*this, OS);
114
115  // Print Constant Pool
116  getConstantPool()->print(OS);
117
118  for (const_iterator BB = begin(); BB != end(); ++BB)
119    BB->print(OS);
120  OS << "\nEnd function \"" << Fn->getName() << "\"\n\n";
121}
122
123void MachineBasicBlock::dump() const { print(std::cerr); }
124
125void MachineBasicBlock::print(std::ostream &OS) const {
126  const BasicBlock *LBB = getBasicBlock();
127  OS << "\n" << LBB->getName() << " (" << (const void*)LBB << "):\n";
128  for (const_iterator I = begin(); I != end(); ++I) {
129    OS << "\t";
130    I->print(OS, MachineFunction::get(LBB->getParent()).getTarget());
131  }
132}
133
134// The next two methods are used to construct and to retrieve
135// the MachineCodeForFunction object for the given function.
136// construct() -- Allocates and initializes for a given function and target
137// get()       -- Returns a handle to the object.
138//                This should not be called before "construct()"
139//                for a given Function.
140//
141MachineFunction&
142MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
143{
144  assert(Fn->getAnnotation(MF_AID) == 0 &&
145         "Object already exists for this function!");
146  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
147  Fn->addAnnotation(mcInfo);
148  return *mcInfo;
149}
150
151void MachineFunction::destruct(const Function *Fn) {
152  bool Deleted = Fn->deleteAnnotation(MF_AID);
153  assert(Deleted && "Machine code did not exist for function!");
154}
155
156MachineFunction& MachineFunction::get(const Function *F)
157{
158  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
159  assert(mc && "Call construct() method first to allocate the object");
160  return *mc;
161}
162
163void MachineFunction::clearSSARegMap() {
164  delete SSARegMapping;
165  SSARegMapping = 0;
166}
167
168//===----------------------------------------------------------------------===//
169//  MachineFrameInfo implementation
170//===----------------------------------------------------------------------===//
171
172/// CreateStackObject - Create a stack object for a value of the specified type.
173///
174int MachineFrameInfo::CreateStackObject(const Type *Ty, const TargetData &TD) {
175  return CreateStackObject(TD.getTypeSize(Ty), TD.getTypeAlignment(Ty));
176}
177
178int MachineFrameInfo::CreateStackObject(const TargetRegisterClass *RC) {
179  return CreateStackObject(RC->getSize(), RC->getAlignment());
180}
181
182
183void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
184  int ValOffset = MF.getTarget().getFrameInfo().getOffsetOfLocalArea();
185
186  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
187    const StackObject &SO = Objects[i];
188    OS << "  <fi #" << (int)(i-NumFixedObjects) << "> is ";
189    if (SO.Size == 0)
190      OS << "variable sized";
191    else
192      OS << SO.Size << " byte" << (SO.Size != 1 ? "s" : " ");
193
194    if (i < NumFixedObjects)
195      OS << " fixed";
196    if (i < NumFixedObjects || SO.SPOffset != -1) {
197      int Off = SO.SPOffset + ValOffset;
198      OS << " at location [SP";
199      if (Off > 0)
200	OS << "+" << Off;
201      else if (Off < 0)
202	OS << Off;
203      OS << "]";
204    }
205    OS << "\n";
206  }
207
208  if (HasVarSizedObjects)
209    OS << "  Stack frame contains variable sized objects\n";
210}
211
212void MachineFrameInfo::dump(const MachineFunction &MF) const {
213  print(MF, std::cerr);
214}
215
216
217//===----------------------------------------------------------------------===//
218//  MachineConstantPool implementation
219//===----------------------------------------------------------------------===//
220
221void MachineConstantPool::print(std::ostream &OS) const {
222  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
223    OS << "  <cp #" << i << "> is" << *(Value*)Constants[i] << "\n";
224}
225
226void MachineConstantPool::dump() const { print(std::cerr); }
227
228//===----------------------------------------------------------------------===//
229//  MachineFunctionInfo implementation
230//===----------------------------------------------------------------------===//
231
232static unsigned
233ComputeMaxOptionalArgsSize(const TargetMachine& target, const Function *F,
234                           unsigned &maxOptionalNumArgs)
235{
236  const TargetFrameInfo &frameInfo = target.getFrameInfo();
237
238  unsigned maxSize = 0;
239
240  for (Function::const_iterator BB = F->begin(), BBE = F->end(); BB !=BBE; ++BB)
241    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
242      if (const CallInst *callInst = dyn_cast<CallInst>(I))
243        {
244          unsigned numOperands = callInst->getNumOperands() - 1;
245          int numExtra = (int)numOperands-frameInfo.getNumFixedOutgoingArgs();
246          if (numExtra <= 0)
247            continue;
248
249          unsigned sizeForThisCall;
250          if (frameInfo.argsOnStackHaveFixedSize())
251            {
252              int argSize = frameInfo.getSizeOfEachArgOnStack();
253              sizeForThisCall = numExtra * (unsigned) argSize;
254            }
255          else
256            {
257              assert(0 && "UNTESTED CODE: Size per stack argument is not "
258                     "fixed on this architecture: use actual arg sizes to "
259                     "compute MaxOptionalArgsSize");
260              sizeForThisCall = 0;
261              for (unsigned i = 0; i < numOperands; ++i)
262                sizeForThisCall += target.getTargetData().getTypeSize(callInst->
263                                              getOperand(i)->getType());
264            }
265
266          if (maxSize < sizeForThisCall)
267            maxSize = sizeForThisCall;
268
269          if ((int)maxOptionalNumArgs < numExtra)
270            maxOptionalNumArgs = (unsigned) numExtra;
271        }
272
273  return maxSize;
274}
275
276// Align data larger than one L1 cache line on L1 cache line boundaries.
277// Align all smaller data on the next higher 2^x boundary (4, 8, ...),
278// but not higher than the alignment of the largest type we support
279// (currently a double word). -- see class TargetData).
280//
281// This function is similar to the corresponding function in EmitAssembly.cpp
282// but they are unrelated.  This one does not align at more than a
283// double-word boundary whereas that one might.
284//
285inline unsigned
286SizeToAlignment(unsigned size, const TargetMachine& target)
287{
288  unsigned short cacheLineSize = target.getCacheInfo().getCacheLineSize(1);
289  if (size > (unsigned) cacheLineSize / 2)
290    return cacheLineSize;
291  else
292    for (unsigned sz=1; /*no condition*/; sz *= 2)
293      if (sz >= size || sz >= target.getTargetData().getDoubleAlignment())
294        return sz;
295}
296
297
298void MachineFunctionInfo::CalculateArgSize() {
299  maxOptionalArgsSize = ComputeMaxOptionalArgsSize(MF.getTarget(),
300						   MF.getFunction(),
301                                                   maxOptionalNumArgs);
302  staticStackSize = maxOptionalArgsSize
303    + MF.getTarget().getFrameInfo().getMinStackFrameSize();
304}
305
306int
307MachineFunctionInfo::computeOffsetforLocalVar(const Value* val,
308					      unsigned &getPaddedSize,
309					      unsigned  sizeToUse)
310{
311  if (sizeToUse == 0)
312    sizeToUse = MF.getTarget().findOptimalStorageSize(val->getType());
313  unsigned align = SizeToAlignment(sizeToUse, MF.getTarget());
314
315  bool growUp;
316  int firstOffset = MF.getTarget().getFrameInfo().getFirstAutomaticVarOffset(MF,
317									     growUp);
318  int offset = growUp? firstOffset + getAutomaticVarsSize()
319                     : firstOffset - (getAutomaticVarsSize() + sizeToUse);
320
321  int aligned = MF.getTarget().getFrameInfo().adjustAlignment(offset, growUp, align);
322  getPaddedSize = sizeToUse + abs(aligned - offset);
323
324  return aligned;
325}
326
327
328int MachineFunctionInfo::allocateLocalVar(const Value* val,
329                                          unsigned sizeToUse) {
330  assert(! automaticVarsAreaFrozen &&
331         "Size of auto vars area has been used to compute an offset so "
332         "no more automatic vars should be allocated!");
333
334  // Check if we've allocated a stack slot for this value already
335  //
336  hash_map<const Value*, int>::const_iterator pair = offsets.find(val);
337  if (pair != offsets.end())
338    return pair->second;
339
340  unsigned getPaddedSize;
341  unsigned offset = computeOffsetforLocalVar(val, getPaddedSize, sizeToUse);
342  offsets[val] = offset;
343  incrementAutomaticVarsSize(getPaddedSize);
344  return offset;
345}
346
347int
348MachineFunctionInfo::allocateSpilledValue(const Type* type)
349{
350  assert(! spillsAreaFrozen &&
351         "Size of reg spills area has been used to compute an offset so "
352         "no more register spill slots should be allocated!");
353
354  unsigned size  = MF.getTarget().getTargetData().getTypeSize(type);
355  unsigned char align = MF.getTarget().getTargetData().getTypeAlignment(type);
356
357  bool growUp;
358  int firstOffset = MF.getTarget().getFrameInfo().getRegSpillAreaOffset(MF, growUp);
359
360  int offset = growUp? firstOffset + getRegSpillsSize()
361                     : firstOffset - (getRegSpillsSize() + size);
362
363  int aligned = MF.getTarget().getFrameInfo().adjustAlignment(offset, growUp, align);
364  size += abs(aligned - offset); // include alignment padding in size
365
366  incrementRegSpillsSize(size);  // update size of reg. spills area
367
368  return aligned;
369}
370
371int
372MachineFunctionInfo::pushTempValue(unsigned size)
373{
374  unsigned align = SizeToAlignment(size, MF.getTarget());
375
376  bool growUp;
377  int firstOffset = MF.getTarget().getFrameInfo().getTmpAreaOffset(MF, growUp);
378
379  int offset = growUp? firstOffset + currentTmpValuesSize
380                     : firstOffset - (currentTmpValuesSize + size);
381
382  int aligned = MF.getTarget().getFrameInfo().adjustAlignment(offset, growUp,
383							      align);
384  size += abs(aligned - offset); // include alignment padding in size
385
386  incrementTmpAreaSize(size);    // update "current" size of tmp area
387
388  return aligned;
389}
390
391void MachineFunctionInfo::popAllTempValues() {
392  resetTmpAreaSize();            // clear tmp area to reuse
393}
394
395