MachineFunction.cpp revision 07f32d48f1e16bcdc621985549548a5849215238 
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/MachineFunction.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/Target/TargetMachine.h"
24#include "llvm/Target/TargetFrameInfo.h"
25#include "llvm/Target/TargetCacheInfo.h"
26#include "llvm/Function.h"
27#include "llvm/iOther.h"
28#include "llvm/Pass.h"
29using namespace llvm;
30
31static AnnotationID MF_AID(
32                 AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
33
34
35namespace {
36  struct Printer : public FunctionPass {
37    const char *getPassName() const { return "MachineFunction Printer"; }
38
39    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
40      AU.setPreservesAll();
41    }
42
43    bool runOnFunction(Function &F) {
44      MachineFunction::get(&F).dump();
45      return false;
46    }
47  };
48}
49
50FunctionPass *llvm::createMachineFunctionPrinterPass() {
51  return new Printer();
52}
53
54
55//===---------------------------------------------------------------------===//
56// MachineFunction implementation
57//===---------------------------------------------------------------------===//
58
59MachineFunction::MachineFunction(const Function *F,
60                                 const TargetMachine &TM)
61  : Annotation(MF_AID), Fn(F), Target(TM) {
62  SSARegMapping = new SSARegMap();
63  MFInfo = new MachineFunctionInfo(*this);
64  FrameInfo = new MachineFrameInfo();
65  ConstantPool = new MachineConstantPool();
66}
67
68MachineFunction::~MachineFunction() {
69  delete SSARegMapping;
70  delete MFInfo;
71  delete FrameInfo;
72  delete ConstantPool;
73}
74
75void MachineFunction::dump() const { print(std::cerr); }
76
77void MachineFunction::print(std::ostream &OS) const {
78  OS << "\n" << *(Value*)Fn->getFunctionType() << " \"" << Fn->getName()
79     << "\"\n";
80
81  // Print Frame Information
82  getFrameInfo()->print(*this, OS);
83
84  // Print Constant Pool
85  getConstantPool()->print(OS);
86
87  for (const_iterator BB = begin(); BB != end(); ++BB) {
88    const BasicBlock *LBB = BB->getBasicBlock();
89    OS << "\n" << LBB->getName() << " (" << (const void*)LBB << "):\n";
90    for (MachineBasicBlock::const_iterator I = BB->begin(); I != BB->end();++I){
91      OS << "\t";
92      (*I)->print(OS, Target);
93    }
94  }
95  OS << "\nEnd function \"" << Fn->getName() << "\"\n\n";
96}
97
98
99// The next two methods are used to construct and to retrieve
100// the MachineCodeForFunction object for the given function.
101// construct() -- Allocates and initializes for a given function and target
102// get()       -- Returns a handle to the object.
103//                This should not be called before "construct()"
104//                for a given Function.
105//
106MachineFunction&
107MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
108{
109  assert(Fn->getAnnotation(MF_AID) == 0 &&
110         "Object already exists for this function!");
111  MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
112  Fn->addAnnotation(mcInfo);
113  return *mcInfo;
114}
115
116void
117MachineFunction::destruct(const Function *Fn)
118{
119  bool Deleted = Fn->deleteAnnotation(MF_AID);
120  assert(Deleted && "Machine code did not exist for function!");
121}
122
123MachineFunction& MachineFunction::get(const Function *F)
124{
125  MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
126  assert(mc && "Call construct() method first to allocate the object");
127  return *mc;
128}
129
130void MachineFunction::clearSSARegMap() {
131  delete SSARegMapping;
132  SSARegMapping = 0;
133}
134
135//===----------------------------------------------------------------------===//
136//  MachineFrameInfo implementation
137//===----------------------------------------------------------------------===//
138
139/// CreateStackObject - Create a stack object for a value of the specified type.
140///
141int MachineFrameInfo::CreateStackObject(const Type *Ty, const TargetData &TD) {
142  return CreateStackObject(TD.getTypeSize(Ty), TD.getTypeAlignment(Ty));
143}
144
145int MachineFrameInfo::CreateStackObject(const TargetRegisterClass *RC) {
146  return CreateStackObject(RC->getSize(), RC->getAlignment());
147}
148
149
150void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
151  int ValOffset = MF.getTarget().getFrameInfo().getOffsetOfLocalArea();
152
153  for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
154    const StackObject &SO = Objects[i];
155    OS << "  <fi #" << (int)(i-NumFixedObjects) << "> is ";
156    if (SO.Size == 0)
157      OS << "variable sized";
158    else
159      OS << SO.Size << " byte" << (SO.Size != 1 ? "s" : " ");
160
161    if (i < NumFixedObjects)
162      OS << " fixed";
163    if (i < NumFixedObjects || SO.SPOffset != -1) {
164      int Off = SO.SPOffset + ValOffset;
165      OS << " at location [SP";
166      if (Off > 0)
167	OS << "+" << Off;
168      else if (Off < 0)
169	OS << Off;
170      OS << "]";
171    }
172    OS << "\n";
173  }
174
175  if (HasVarSizedObjects)
176    OS << "  Stack frame contains variable sized objects\n";
177}
178
179void MachineFrameInfo::dump(const MachineFunction &MF) const {
180  print(MF, std::cerr);
181}
182
183
184//===----------------------------------------------------------------------===//
185//  MachineConstantPool implementation
186//===----------------------------------------------------------------------===//
187
188void MachineConstantPool::print(std::ostream &OS) const {
189  for (unsigned i = 0, e = Constants.size(); i != e; ++i)
190    OS << "  <cp #" << i << "> is" << *(Value*)Constants[i] << "\n";
191}
192
193void MachineConstantPool::dump() const { print(std::cerr); }
194
195//===----------------------------------------------------------------------===//
196//  MachineFunctionInfo implementation
197//===----------------------------------------------------------------------===//
198
199static unsigned
200ComputeMaxOptionalArgsSize(const TargetMachine& target, const Function *F,
201                           unsigned &maxOptionalNumArgs)
202{
203  const TargetFrameInfo &frameInfo = target.getFrameInfo();
204
205  unsigned maxSize = 0;
206
207  for (Function::const_iterator BB = F->begin(), BBE = F->end(); BB !=BBE; ++BB)
208    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
209      if (const CallInst *callInst = dyn_cast<CallInst>(I))
210        {
211          unsigned numOperands = callInst->getNumOperands() - 1;
212          int numExtra = (int)numOperands-frameInfo.getNumFixedOutgoingArgs();
213          if (numExtra <= 0)
214            continue;
215
216          unsigned sizeForThisCall;
217          if (frameInfo.argsOnStackHaveFixedSize())
218            {
219              int argSize = frameInfo.getSizeOfEachArgOnStack();
220              sizeForThisCall = numExtra * (unsigned) argSize;
221            }
222          else
223            {
224              assert(0 && "UNTESTED CODE: Size per stack argument is not "
225                     "fixed on this architecture: use actual arg sizes to "
226                     "compute MaxOptionalArgsSize");
227              sizeForThisCall = 0;
228              for (unsigned i = 0; i < numOperands; ++i)
229                sizeForThisCall += target.getTargetData().getTypeSize(callInst->
230                                              getOperand(i)->getType());
231            }
232
233          if (maxSize < sizeForThisCall)
234            maxSize = sizeForThisCall;
235
236          if ((int)maxOptionalNumArgs < numExtra)
237            maxOptionalNumArgs = (unsigned) numExtra;
238        }
239
240  return maxSize;
241}
242
243// Align data larger than one L1 cache line on L1 cache line boundaries.
244// Align all smaller data on the next higher 2^x boundary (4, 8, ...),
245// but not higher than the alignment of the largest type we support
246// (currently a double word). -- see class TargetData).
247//
248// This function is similar to the corresponding function in EmitAssembly.cpp
249// but they are unrelated.  This one does not align at more than a
250// double-word boundary whereas that one might.
251//
252inline unsigned
253SizeToAlignment(unsigned size, const TargetMachine& target)
254{
255  unsigned short cacheLineSize = target.getCacheInfo().getCacheLineSize(1);
256  if (size > (unsigned) cacheLineSize / 2)
257    return cacheLineSize;
258  else
259    for (unsigned sz=1; /*no condition*/; sz *= 2)
260      if (sz >= size || sz >= target.getTargetData().getDoubleAlignment())
261        return sz;
262}
263
264
265void MachineFunctionInfo::CalculateArgSize() {
266  maxOptionalArgsSize = ComputeMaxOptionalArgsSize(MF.getTarget(),
267						   MF.getFunction(),
268                                                   maxOptionalNumArgs);
269  staticStackSize = maxOptionalArgsSize
270    + MF.getTarget().getFrameInfo().getMinStackFrameSize();
271}
272
273int
274MachineFunctionInfo::computeOffsetforLocalVar(const Value* val,
275					      unsigned &getPaddedSize,
276					      unsigned  sizeToUse)
277{
278  if (sizeToUse == 0)
279    sizeToUse = MF.getTarget().findOptimalStorageSize(val->getType());
280  unsigned align = SizeToAlignment(sizeToUse, MF.getTarget());
281
282  bool growUp;
283  int firstOffset = MF.getTarget().getFrameInfo().getFirstAutomaticVarOffset(MF,
284									     growUp);
285  int offset = growUp? firstOffset + getAutomaticVarsSize()
286                     : firstOffset - (getAutomaticVarsSize() + sizeToUse);
287
288  int aligned = MF.getTarget().getFrameInfo().adjustAlignment(offset, growUp, align);
289  getPaddedSize = sizeToUse + abs(aligned - offset);
290
291  return aligned;
292}
293
294
295int MachineFunctionInfo::allocateLocalVar(const Value* val,
296                                          unsigned sizeToUse) {
297  assert(! automaticVarsAreaFrozen &&
298         "Size of auto vars area has been used to compute an offset so "
299         "no more automatic vars should be allocated!");
300
301  // Check if we've allocated a stack slot for this value already
302  //
303  hash_map<const Value*, int>::const_iterator pair = offsets.find(val);
304  if (pair != offsets.end())
305    return pair->second;
306
307  unsigned getPaddedSize;
308  unsigned offset = computeOffsetforLocalVar(val, getPaddedSize, sizeToUse);
309  offsets[val] = offset;
310  incrementAutomaticVarsSize(getPaddedSize);
311  return offset;
312}
313
314int
315MachineFunctionInfo::allocateSpilledValue(const Type* type)
316{
317  assert(! spillsAreaFrozen &&
318         "Size of reg spills area has been used to compute an offset so "
319         "no more register spill slots should be allocated!");
320
321  unsigned size  = MF.getTarget().getTargetData().getTypeSize(type);
322  unsigned char align = MF.getTarget().getTargetData().getTypeAlignment(type);
323
324  bool growUp;
325  int firstOffset = MF.getTarget().getFrameInfo().getRegSpillAreaOffset(MF, growUp);
326
327  int offset = growUp? firstOffset + getRegSpillsSize()
328                     : firstOffset - (getRegSpillsSize() + size);
329
330  int aligned = MF.getTarget().getFrameInfo().adjustAlignment(offset, growUp, align);
331  size += abs(aligned - offset); // include alignment padding in size
332
333  incrementRegSpillsSize(size);  // update size of reg. spills area
334
335  return aligned;
336}
337
338int
339MachineFunctionInfo::pushTempValue(unsigned size)
340{
341  unsigned align = SizeToAlignment(size, MF.getTarget());
342
343  bool growUp;
344  int firstOffset = MF.getTarget().getFrameInfo().getTmpAreaOffset(MF, growUp);
345
346  int offset = growUp? firstOffset + currentTmpValuesSize
347                     : firstOffset - (currentTmpValuesSize + size);
348
349  int aligned = MF.getTarget().getFrameInfo().adjustAlignment(offset, growUp,
350							      align);
351  size += abs(aligned - offset); // include alignment padding in size
352
353  incrementTmpAreaSize(size);    // update "current" size of tmp area
354
355  return aligned;
356}
357
358void MachineFunctionInfo::popAllTempValues() {
359  resetTmpAreaSize();            // clear tmp area to reuse
360}
361
362