aboutsummaryrefslogtreecommitdiffstats
path: root/lib/VMCore/Pass.cpp
blob: 2f581c51abf0dc49bfe5132549f3e40299bff52f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
//===- Pass.cpp - LLVM Pass Infrastructure Implementation -----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LLVM Pass infrastructure.  It is primarily
// responsible with ensuring that passes are executed and batched together
// optimally.
//
//===----------------------------------------------------------------------===//

#include "llvm/PassManager.h"
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/TypeInfo.h"
#include <algorithm>
#include <set>
using namespace llvm;

//===----------------------------------------------------------------------===//
// Pass Implementation
//

// Force out-of-line virtual method.
Pass::~Pass() { 
  delete Resolver; 
}

// Force out-of-line virtual method.
ModulePass::~ModulePass() { }

bool Pass::mustPreserveAnalysisID(const PassInfo *AnalysisID) const {
  return Resolver->getAnalysisToUpdate(AnalysisID, true) != 0;
}

// dumpPassStructure - Implement the -debug-passes=Structure option
void Pass::dumpPassStructure(unsigned Offset) {
  cerr << std::string(Offset*2, ' ') << getPassName() << "\n";
}

// getPassName - Use C++ RTTI to get a SOMEWHAT intelligible name for the pass.
//
const char *Pass::getPassName() const {
  if (const PassInfo *PI = getPassInfo())
    return PI->getPassName();
  return typeid(*this).name();
}

// print - Print out the internal state of the pass.  This is called by Analyze
// to print out the contents of an analysis.  Otherwise it is not necessary to
// implement this method.
//
void Pass::print(std::ostream &O,const Module*) const {
  O << "Pass::print not implemented for pass: '" << getPassName() << "'!\n";
}

// dump - call print(cerr);
void Pass::dump() const {
  print(*cerr.stream(), 0);
}

//===----------------------------------------------------------------------===//
// ImmutablePass Implementation
//
// Force out-of-line virtual method.
ImmutablePass::~ImmutablePass() { }

//===----------------------------------------------------------------------===//
// FunctionPass Implementation
//

// run - On a module, we run this pass by initializing, runOnFunction'ing once
// for every function in the module, then by finalizing.
//
bool FunctionPass::runOnModule(Module &M) {
  bool Changed = doInitialization(M);

  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration())      // Passes are not run on external functions!
    Changed |= runOnFunction(*I);

  return Changed | doFinalization(M);
}

// run - On a function, we simply initialize, run the function, then finalize.
//
bool FunctionPass::run(Function &F) {
  if (F.isDeclaration()) return false;// Passes are not run on external functions!

  bool Changed = doInitialization(*F.getParent());
  Changed |= runOnFunction(F);
  return Changed | doFinalization(*F.getParent());
}

//===----------------------------------------------------------------------===//
// BasicBlockPass Implementation
//

// To run this pass on a function, we simply call runOnBasicBlock once for each
// function.
//
bool BasicBlockPass::runOnFunction(Function &F) {
  bool Changed = doInitialization(F);
  for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
    Changed |= runOnBasicBlock(*I);
  return Changed | doFinalization(F);
}

// To run directly on the basic block, we initialize, runOnBasicBlock, then
// finalize.
//
bool BasicBlockPass::runPass(BasicBlock &BB) {
  Function &F = *BB.getParent();
  Module &M = *F.getParent();
  bool Changed = doInitialization(M);
  Changed |= doInitialization(F);
  Changed |= runOnBasicBlock(BB);
  Changed |= doFinalization(F);
  Changed |= doFinalization(M);
  return Changed;
}

//===----------------------------------------------------------------------===//
// Pass Registration mechanism
//
namespace {
class PassRegistrar {
  /// PassInfoMap - Keep track of the passinfo object for each registered llvm
  /// pass.
  std::map<intptr_t, PassInfo*> PassInfoMap;
  
  /// AnalysisGroupInfo - Keep track of information for each analysis group.
  struct AnalysisGroupInfo {
    const PassInfo *DefaultImpl;
    std::set<const PassInfo *> Implementations;
    AnalysisGroupInfo() : DefaultImpl(0) {}
  };
  
  /// AnalysisGroupInfoMap - Information for each analysis group.
  std::map<const PassInfo *, AnalysisGroupInfo> AnalysisGroupInfoMap;

public:
  
  const PassInfo *GetPassInfo(intptr_t TI) const {
    std::map<intptr_t, PassInfo*>::const_iterator I = PassInfoMap.find(TI);
    return I != PassInfoMap.end() ? I->second : 0;
  }
  
  void RegisterPass(PassInfo &PI) {
    bool Inserted =
      PassInfoMap.insert(std::make_pair(PI.getTypeInfo(),&PI)).second;
    assert(Inserted && "Pass registered multiple times!");
  }
  
  void UnregisterPass(PassInfo &PI) {
    std::map<intptr_t, PassInfo*>::iterator I =
      PassInfoMap.find(PI.getTypeInfo());
    assert(I != PassInfoMap.end() && "Pass registered but not in map!");
    
    // Remove pass from the map.
    PassInfoMap.erase(I);
  }
  
  void EnumerateWith(PassRegistrationListener *L) {
    for (std::map<intptr_t, PassInfo*>::const_iterator I = PassInfoMap.begin(),
         E = PassInfoMap.end(); I != E; ++I)
      L->passEnumerate(I->second);
  }
  
  
  /// Analysis Group Mechanisms.
  void RegisterAnalysisGroup(PassInfo *InterfaceInfo,
                             const PassInfo *ImplementationInfo,
                             bool isDefault) {
    AnalysisGroupInfo &AGI = AnalysisGroupInfoMap[InterfaceInfo];
    assert(AGI.Implementations.count(ImplementationInfo) == 0 &&
           "Cannot add a pass to the same analysis group more than once!");
    AGI.Implementations.insert(ImplementationInfo);
    if (isDefault) {
      assert(AGI.DefaultImpl == 0 && InterfaceInfo->getNormalCtor() == 0 &&
             "Default implementation for analysis group already specified!");
      assert(ImplementationInfo->getNormalCtor() &&
           "Cannot specify pass as default if it does not have a default ctor");
      AGI.DefaultImpl = ImplementationInfo;
      InterfaceInfo->setNormalCtor(ImplementationInfo->getNormalCtor());
    }
  }
};
}

static std::vector<PassRegistrationListener*> *Listeners = 0;

// FIXME: This should use ManagedStatic to manage the pass registrar.
// Unfortunately, we can't do this, because passes are registered with static
// ctors, and having llvm_shutdown clear this map prevents successful
// ressurection after llvm_shutdown is run.
static PassRegistrar *getPassRegistrar() {
  static PassRegistrar *PassRegistrarObj = 0;
  if (!PassRegistrarObj)
    PassRegistrarObj = new PassRegistrar();
  return PassRegistrarObj;
}

// getPassInfo - Return the PassInfo data structure that corresponds to this
// pass...
const PassInfo *Pass::getPassInfo() const {
  return lookupPassInfo(PassID);
}

const PassInfo *Pass::lookupPassInfo(intptr_t TI) {
  return getPassRegistrar()->GetPassInfo(TI);
}

void RegisterPassBase::registerPass() {
  getPassRegistrar()->RegisterPass(PIObj);

  // Notify any listeners.
  if (Listeners)
    for (std::vector<PassRegistrationListener*>::iterator
           I = Listeners->begin(), E = Listeners->end(); I != E; ++I)
      (*I)->passRegistered(&PIObj);
}

void RegisterPassBase::unregisterPass() {
  getPassRegistrar()->UnregisterPass(PIObj);
}

//===----------------------------------------------------------------------===//
//                  Analysis Group Implementation Code
//===----------------------------------------------------------------------===//

// RegisterAGBase implementation
//
RegisterAGBase::RegisterAGBase(intptr_t InterfaceID,
                               intptr_t PassID, bool isDefault)
  : RegisterPassBase(InterfaceID),
    ImplementationInfo(0), isDefaultImplementation(isDefault) {

  InterfaceInfo = const_cast<PassInfo*>(Pass::lookupPassInfo(InterfaceID));
  if (InterfaceInfo == 0) {
    // First reference to Interface, register it now.
    registerPass();
    InterfaceInfo = &PIObj;
  }
  assert(PIObj.isAnalysisGroup() &&
         "Trying to join an analysis group that is a normal pass!");

  if (PassID) {
    ImplementationInfo = Pass::lookupPassInfo(PassID);
    assert(ImplementationInfo &&
           "Must register pass before adding to AnalysisGroup!");

    // Make sure we keep track of the fact that the implementation implements
    // the interface.
    PassInfo *IIPI = const_cast<PassInfo*>(ImplementationInfo);
    IIPI->addInterfaceImplemented(InterfaceInfo);
    
    getPassRegistrar()->RegisterAnalysisGroup(InterfaceInfo, IIPI, isDefault);
  }
}

void RegisterAGBase::setGroupName(const char *Name) {
  assert(InterfaceInfo->getPassName()[0] == 0 && "Interface Name already set!");
  InterfaceInfo->setPassName(Name);
}


//===----------------------------------------------------------------------===//
// PassRegistrationListener implementation
//

// PassRegistrationListener ctor - Add the current object to the list of
// PassRegistrationListeners...
PassRegistrationListener::PassRegistrationListener() {
  if (!Listeners) Listeners = new std::vector<PassRegistrationListener*>();
  Listeners->push_back(this);
}

// dtor - Remove object from list of listeners...
PassRegistrationListener::~PassRegistrationListener() {
  std::vector<PassRegistrationListener*>::iterator I =
    std::find(Listeners->begin(), Listeners->end(), this);
  assert(Listeners && I != Listeners->end() &&
         "PassRegistrationListener not registered!");
  Listeners->erase(I);

  if (Listeners->empty()) {
    delete Listeners;
    Listeners = 0;
  }
}

// enumeratePasses - Iterate over the registered passes, calling the
// passEnumerate callback on each PassInfo object.
//
void PassRegistrationListener::enumeratePasses() {
  getPassRegistrar()->EnumerateWith(this);
}

//===----------------------------------------------------------------------===//
//   AnalysisUsage Class Implementation
//

namespace {
  struct GetCFGOnlyPasses : public PassRegistrationListener {
    std::vector<AnalysisID> &CFGOnlyList;
    GetCFGOnlyPasses(std::vector<AnalysisID> &L) : CFGOnlyList(L) {}
    
    void passEnumerate(const PassInfo *P) {
      if (P->isCFGOnlyPass())
        CFGOnlyList.push_back(P);
    }
  };
}

// setPreservesCFG - This function should be called to by the pass, iff they do
// not:
//
//  1. Add or remove basic blocks from the function
//  2. Modify terminator instructions in any way.
//
// This function annotates the AnalysisUsage info object to say that analyses
// that only depend on the CFG are preserved by this pass.
//
void AnalysisUsage::setPreservesCFG() {
  // Since this transformation doesn't modify the CFG, it preserves all analyses
  // that only depend on the CFG (like dominators, loop info, etc...)
  GetCFGOnlyPasses(Preserved).enumeratePasses();
}