Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/lib/Transforms/Utils/CloneFunction.cpp
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Source (jump to first uncovered line)
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//===- CloneFunction.cpp - Clone a function into another function ---------===//
2
//
3
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4
// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//
7
//===----------------------------------------------------------------------===//
8
//
9
// This file implements the CloneFunctionInto interface, which is used as the
10
// low-level function cloner.  This is used by the CloneFunction and function
11
// inliner to do the dirty work of copying the body of a function around.
12
//
13
//===----------------------------------------------------------------------===//
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15
#include "llvm/ADT/SetVector.h"
16
#include "llvm/ADT/SmallVector.h"
17
#include "llvm/Analysis/ConstantFolding.h"
18
#include "llvm/Analysis/DomTreeUpdater.h"
19
#include "llvm/Analysis/InstructionSimplify.h"
20
#include "llvm/Analysis/LoopInfo.h"
21
#include "llvm/IR/CFG.h"
22
#include "llvm/IR/Constants.h"
23
#include "llvm/IR/DebugInfo.h"
24
#include "llvm/IR/DerivedTypes.h"
25
#include "llvm/IR/Function.h"
26
#include "llvm/IR/GlobalVariable.h"
27
#include "llvm/IR/Instructions.h"
28
#include "llvm/IR/IntrinsicInst.h"
29
#include "llvm/IR/LLVMContext.h"
30
#include "llvm/IR/Metadata.h"
31
#include "llvm/IR/Module.h"
32
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
33
#include "llvm/Transforms/Utils/Cloning.h"
34
#include "llvm/Transforms/Utils/Local.h"
35
#include "llvm/Transforms/Utils/ValueMapper.h"
36
#include <map>
37
using namespace llvm;
38
39
/// See comments in Cloning.h.
40
BasicBlock *llvm::CloneBasicBlock(const BasicBlock *BB, ValueToValueMapTy &VMap,
41
                                  const Twine &NameSuffix, Function *F,
42
                                  ClonedCodeInfo *CodeInfo,
43
347k
                                  DebugInfoFinder *DIFinder) {
44
347k
  DenseMap<const MDNode *, MDNode *> Cache;
45
347k
  BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "", F);
46
347k
  if (BB->hasName())
47
144k
    NewBB->setName(BB->getName() + NameSuffix);
48
347k
49
347k
  bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
50
347k
  Module *TheModule = F ? 
F->getParent()67.6k
:
nullptr280k
;
51
347k
52
347k
  // Loop over all instructions, and copy them over.
53
2.32M
  for (const Instruction &I : *BB) {
54
2.32M
    if (DIFinder && 
TheModule5.40k
)
55
5.40k
      DIFinder->processInstruction(*TheModule, I);
56
2.32M
57
2.32M
    Instruction *NewInst = I.clone();
58
2.32M
    if (I.hasName())
59
468k
      NewInst->setName(I.getName() + NameSuffix);
60
2.32M
    NewBB->getInstList().push_back(NewInst);
61
2.32M
    VMap[&I] = NewInst; // Add instruction map to value.
62
2.32M
63
2.32M
    hasCalls |= (isa<CallInst>(I) && 
!isa<DbgInfoIntrinsic>(I)46.0k
);
64
2.32M
    if (const AllocaInst *AI = dyn_cast<AllocaInst>(&I)) {
65
101
      if (isa<ConstantInt>(AI->getArraySize()))
66
87
        hasStaticAllocas = true;
67
14
      else
68
14
        hasDynamicAllocas = true;
69
101
    }
70
2.32M
  }
71
347k
72
347k
  if (CodeInfo) {
73
0
    CodeInfo->ContainsCalls          |= hasCalls;
74
0
    CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
75
0
    CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
76
0
                                        BB != &BB->getParent()->getEntryBlock();
77
0
  }
78
347k
  return NewBB;
79
347k
}
80
81
// Clone OldFunc into NewFunc, transforming the old arguments into references to
82
// VMap values.
83
//
84
void llvm::CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
85
                             ValueToValueMapTy &VMap,
86
                             bool ModuleLevelChanges,
87
                             SmallVectorImpl<ReturnInst*> &Returns,
88
                             const char *NameSuffix, ClonedCodeInfo *CodeInfo,
89
                             ValueMapTypeRemapper *TypeMapper,
90
519
                             ValueMaterializer *Materializer) {
91
519
  assert(NameSuffix && "NameSuffix cannot be null!");
92
519
93
#ifndef NDEBUG
94
  for (const Argument &I : OldFunc->args())
95
    assert(VMap.count(&I) && "No mapping from source argument specified!");
96
#endif
97
98
519
  // Copy all attributes other than those stored in the AttributeList.  We need
99
519
  // to remap the parameter indices of the AttributeList.
100
519
  AttributeList NewAttrs = NewFunc->getAttributes();
101
519
  NewFunc->copyAttributesFrom(OldFunc);
102
519
  NewFunc->setAttributes(NewAttrs);
103
519
104
519
  // Fix up the personality function that got copied over.
105
519
  if (OldFunc->hasPersonalityFn())
106
41
    NewFunc->setPersonalityFn(
107
41
        MapValue(OldFunc->getPersonalityFn(), VMap,
108
41
                 ModuleLevelChanges ? 
RF_None35
:
RF_NoModuleLevelChanges6
,
109
41
                 TypeMapper, Materializer));
110
519
111
519
  SmallVector<AttributeSet, 4> NewArgAttrs(NewFunc->arg_size());
112
519
  AttributeList OldAttrs = OldFunc->getAttributes();
113
519
114
519
  // Clone any argument attributes that are present in the VMap.
115
519
  for (const Argument &OldArg : OldFunc->args()) {
116
422
    if (Argument *NewArg = dyn_cast<Argument>(VMap[&OldArg])) {
117
340
      NewArgAttrs[NewArg->getArgNo()] =
118
340
          OldAttrs.getParamAttributes(OldArg.getArgNo());
119
340
    }
120
422
  }
121
519
122
519
  NewFunc->setAttributes(
123
519
      AttributeList::get(NewFunc->getContext(), OldAttrs.getFnAttributes(),
124
519
                         OldAttrs.getRetAttributes(), NewArgAttrs));
125
519
126
519
  bool MustCloneSP =
127
519
      OldFunc->getParent() && 
OldFunc->getParent() == NewFunc->getParent()517
;
128
519
  DISubprogram *SP = OldFunc->getSubprogram();
129
519
  if (SP) {
130
54
    assert(!MustCloneSP || ModuleLevelChanges);
131
54
    // Add mappings for some DebugInfo nodes that we don't want duplicated
132
54
    // even if they're distinct.
133
54
    auto &MD = VMap.MD();
134
54
    MD[SP->getUnit()].reset(SP->getUnit());
135
54
    MD[SP->getType()].reset(SP->getType());
136
54
    MD[SP->getFile()].reset(SP->getFile());
137
54
    // If we're not cloning into the same module, no need to clone the
138
54
    // subprogram
139
54
    if (!MustCloneSP)
140
29
      MD[SP].reset(SP);
141
54
  }
142
519
143
519
  SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
144
519
  OldFunc->getAllMetadata(MDs);
145
519
  for (auto MD : MDs) {
146
63
    NewFunc->addMetadata(
147
63
        MD.first,
148
63
        *MapMetadata(MD.second, VMap,
149
63
                     ModuleLevelChanges ? 
RF_None54
:
RF_NoModuleLevelChanges9
,
150
63
                     TypeMapper, Materializer));
151
63
  }
152
519
153
519
  // When we remap instructions, we want to avoid duplicating inlined
154
519
  // DISubprograms, so record all subprograms we find as we duplicate
155
519
  // instructions and then freeze them in the MD map.
156
519
  // We also record information about dbg.value and dbg.declare to avoid
157
519
  // duplicating the types.
158
519
  DebugInfoFinder DIFinder;
159
519
160
519
  // Loop over all of the basic blocks in the function, cloning them as
161
519
  // appropriate.  Note that we save BE this way in order to handle cloning of
162
519
  // recursive functions into themselves.
163
519
  //
164
519
  for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
165
3.22k
       BI != BE; 
++BI2.70k
) {
166
2.70k
    const BasicBlock &BB = *BI;
167
2.70k
168
2.70k
    // Create a new basic block and copy instructions into it!
169
2.70k
    BasicBlock *CBB = CloneBasicBlock(&BB, VMap, NameSuffix, NewFunc, CodeInfo,
170
2.70k
                                      ModuleLevelChanges ? 
&DIFinder2.27k
:
nullptr433
);
171
2.70k
172
2.70k
    // Add basic block mapping.
173
2.70k
    VMap[&BB] = CBB;
174
2.70k
175
2.70k
    // It is only legal to clone a function if a block address within that
176
2.70k
    // function is never referenced outside of the function.  Given that, we
177
2.70k
    // want to map block addresses from the old function to block addresses in
178
2.70k
    // the clone. (This is different from the generic ValueMapper
179
2.70k
    // implementation, which generates an invalid blockaddress when
180
2.70k
    // cloning a function.)
181
2.70k
    if (BB.hasAddressTaken()) {
182
2
      Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
183
2
                                              const_cast<BasicBlock*>(&BB));
184
2
      VMap[OldBBAddr] = BlockAddress::get(NewFunc, CBB);
185
2
    }
186
2.70k
187
2.70k
    // Note return instructions for the caller.
188
2.70k
    if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
189
523
      Returns.push_back(RI);
190
2.70k
  }
191
519
192
519
  for (DISubprogram *ISP : DIFinder.subprograms())
193
64
    if (ISP != SP)
194
40
      VMap.MD()[ISP].reset(ISP);
195
519
196
519
  for (DICompileUnit *CU : DIFinder.compile_units())
197
57
    VMap.MD()[CU].reset(CU);
198
519
199
519
  for (DIType *Type : DIFinder.types())
200
115
    VMap.MD()[Type].reset(Type);
201
519
202
519
  // Loop over all of the instructions in the function, fixing up operand
203
519
  // references as we go.  This uses VMap to do all the hard work.
204
519
  for (Function::iterator BB =
205
519
           cast<BasicBlock>(VMap[&OldFunc->front()])->getIterator(),
206
519
                          BE = NewFunc->end();
207
3.22k
       BB != BE; 
++BB2.70k
)
208
2.70k
    // Loop over all instructions, fixing each one as we find it...
209
2.70k
    for (Instruction &II : *BB)
210
6.84k
      RemapInstruction(&II, VMap,
211
6.84k
                       ModuleLevelChanges ? 
RF_None5.40k
:
RF_NoModuleLevelChanges1.43k
,
212
6.84k
                       TypeMapper, Materializer);
213
519
}
214
215
/// Return a copy of the specified function and add it to that function's
216
/// module.  Also, any references specified in the VMap are changed to refer to
217
/// their mapped value instead of the original one.  If any of the arguments to
218
/// the function are in the VMap, the arguments are deleted from the resultant
219
/// function.  The VMap is updated to include mappings from all of the
220
/// instructions and basicblocks in the function from their old to new values.
221
///
222
Function *llvm::CloneFunction(Function *F, ValueToValueMapTy &VMap,
223
136
                              ClonedCodeInfo *CodeInfo) {
224
136
  std::vector<Type*> ArgTypes;
225
136
226
136
  // The user might be deleting arguments to the function by specifying them in
227
136
  // the VMap.  If so, we need to not add the arguments to the arg ty vector
228
136
  //
229
136
  for (const Argument &I : F->args())
230
114
    if (VMap.count(&I) == 0) // Haven't mapped the argument to anything yet?
231
114
      ArgTypes.push_back(I.getType());
232
136
233
136
  // Create a new function type...
234
136
  FunctionType *FTy = FunctionType::get(F->getFunctionType()->getReturnType(),
235
136
                                    ArgTypes, F->getFunctionType()->isVarArg());
236
136
237
136
  // Create the new function...
238
136
  Function *NewF = Function::Create(FTy, F->getLinkage(), F->getAddressSpace(),
239
136
                                    F->getName(), F->getParent());
240
136
241
136
  // Loop over the arguments, copying the names of the mapped arguments over...
242
136
  Function::arg_iterator DestI = NewF->arg_begin();
243
136
  for (const Argument & I : F->args())
244
114
    if (VMap.count(&I) == 0) {     // Is this argument preserved?
245
114
      DestI->setName(I.getName()); // Copy the name over...
246
114
      VMap[&I] = &*DestI++;        // Add mapping to VMap
247
114
    }
248
136
249
136
  SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
250
136
  CloneFunctionInto(NewF, F, VMap, F->getSubprogram() != nullptr, Returns, "",
251
136
                    CodeInfo);
252
136
253
136
  return NewF;
254
136
}
255
256
257
258
namespace {
259
  /// This is a private class used to implement CloneAndPruneFunctionInto.
260
  struct PruningFunctionCloner {
261
    Function *NewFunc;
262
    const Function *OldFunc;
263
    ValueToValueMapTy &VMap;
264
    bool ModuleLevelChanges;
265
    const char *NameSuffix;
266
    ClonedCodeInfo *CodeInfo;
267
268
  public:
269
    PruningFunctionCloner(Function *newFunc, const Function *oldFunc,
270
                          ValueToValueMapTy &valueMap, bool moduleLevelChanges,
271
                          const char *nameSuffix, ClonedCodeInfo *codeInfo)
272
        : NewFunc(newFunc), OldFunc(oldFunc), VMap(valueMap),
273
          ModuleLevelChanges(moduleLevelChanges), NameSuffix(nameSuffix),
274
541k
          CodeInfo(codeInfo) {}
275
276
    /// The specified block is found to be reachable, clone it and
277
    /// anything that it can reach.
278
    void CloneBlock(const BasicBlock *BB,
279
                    BasicBlock::const_iterator StartingInst,
280
                    std::vector<const BasicBlock*> &ToClone);
281
  };
282
}
283
284
/// The specified block is found to be reachable, clone it and
285
/// anything that it can reach.
286
void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
287
                                       BasicBlock::const_iterator StartingInst,
288
1.55M
                                       std::vector<const BasicBlock*> &ToClone){
289
1.55M
  WeakTrackingVH &BBEntry = VMap[BB];
290
1.55M
291
1.55M
  // Have we already cloned this block?
292
1.55M
  if (BBEntry) 
return336k
;
293
1.21M
294
1.21M
  // Nope, clone it now.
295
1.21M
  BasicBlock *NewBB;
296
1.21M
  BBEntry = NewBB = BasicBlock::Create(BB->getContext());
297
1.21M
  if (BB->hasName()) 
NewBB->setName(BB->getName()+NameSuffix)34.4k
;
298
1.21M
299
1.21M
  // It is only legal to clone a function if a block address within that
300
1.21M
  // function is never referenced outside of the function.  Given that, we
301
1.21M
  // want to map block addresses from the old function to block addresses in
302
1.21M
  // the clone. (This is different from the generic ValueMapper
303
1.21M
  // implementation, which generates an invalid blockaddress when
304
1.21M
  // cloning a function.)
305
1.21M
  //
306
1.21M
  // Note that we don't need to fix the mapping for unreachable blocks;
307
1.21M
  // the default mapping there is safe.
308
1.21M
  if (BB->hasAddressTaken()) {
309
4
    Constant *OldBBAddr = BlockAddress::get(const_cast<Function*>(OldFunc),
310
4
                                            const_cast<BasicBlock*>(BB));
311
4
    VMap[OldBBAddr] = BlockAddress::get(NewFunc, NewBB);
312
4
  }
313
1.21M
314
1.21M
  bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
315
1.21M
316
1.21M
  // Loop over all instructions, and copy them over, DCE'ing as we go.  This
317
1.21M
  // loop doesn't include the terminator.
318
1.21M
  for (BasicBlock::const_iterator II = StartingInst, IE = --BB->end();
319
6.14M
       II != IE; 
++II4.92M
) {
320
4.92M
321
4.92M
    Instruction *NewInst = II->clone();
322
4.92M
323
4.92M
    // Eagerly remap operands to the newly cloned instruction, except for PHI
324
4.92M
    // nodes for which we defer processing until we update the CFG.
325
4.92M
    if (!isa<PHINode>(NewInst)) {
326
4.74M
      RemapInstruction(NewInst, VMap,
327
4.74M
                       ModuleLevelChanges ? 
RF_None0
: RF_NoModuleLevelChanges);
328
4.74M
329
4.74M
      // If we can simplify this instruction to some other value, simply add
330
4.74M
      // a mapping to that value rather than inserting a new instruction into
331
4.74M
      // the basic block.
332
4.74M
      if (Value *V =
333
119k
              SimplifyInstruction(NewInst, BB->getModule()->getDataLayout())) {
334
119k
        // On the off-chance that this simplifies to an instruction in the old
335
119k
        // function, map it back into the new function.
336
119k
        if (NewFunc != OldFunc)
337
119k
          if (Value *MappedV = VMap.lookup(V))
338
9.10k
            V = MappedV;
339
119k
340
119k
        if (!NewInst->mayHaveSideEffects()) {
341
119k
          VMap[&*II] = V;
342
119k
          NewInst->deleteValue();
343
119k
          continue;
344
119k
        }
345
4.80M
      }
346
4.74M
    }
347
4.80M
348
4.80M
    if (II->hasName())
349
149k
      NewInst->setName(II->getName()+NameSuffix);
350
4.80M
    VMap[&*II] = NewInst; // Add instruction map to value.
351
4.80M
    NewBB->getInstList().push_back(NewInst);
352
4.80M
    hasCalls |= (isa<CallInst>(II) && 
!isa<DbgInfoIntrinsic>(II)419k
);
353
4.80M
354
4.80M
    if (CodeInfo)
355
4.80M
      if (auto CS = ImmutableCallSite(&*II))
356
419k
        if (CS.hasOperandBundles())
357
51
          CodeInfo->OperandBundleCallSites.push_back(NewInst);
358
4.80M
359
4.80M
    if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
360
103k
      if (isa<ConstantInt>(AI->getArraySize()))
361
103k
        hasStaticAllocas = true;
362
17
      else
363
17
        hasDynamicAllocas = true;
364
103k
    }
365
4.80M
  }
366
1.21M
367
1.21M
  // Finally, clone over the terminator.
368
1.21M
  const Instruction *OldTI = BB->getTerminator();
369
1.21M
  bool TerminatorDone = false;
370
1.21M
  if (const BranchInst *BI = dyn_cast<BranchInst>(OldTI)) {
371
611k
    if (BI->isConditional()) {
372
363k
      // If the condition was a known constant in the callee...
373
363k
      ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition());
374
363k
      // Or is a known constant in the caller...
375
363k
      if (!Cond) {
376
363k
        Value *V = VMap.lookup(BI->getCondition());
377
363k
        Cond = dyn_cast_or_null<ConstantInt>(V);
378
363k
      }
379
363k
380
363k
      // Constant fold to uncond branch!
381
363k
      if (Cond) {
382
21.9k
        BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
383
21.9k
        VMap[OldTI] = BranchInst::Create(Dest, NewBB);
384
21.9k
        ToClone.push_back(Dest);
385
21.9k
        TerminatorDone = true;
386
21.9k
      }
387
363k
    }
388
611k
  } else 
if (const SwitchInst *606k
SI606k
= dyn_cast<SwitchInst>(OldTI)) {
389
19.8k
    // If switching on a value known constant in the caller.
390
19.8k
    ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition());
391
19.8k
    if (!Cond) { // Or known constant after constant prop in the callee...
392
19.8k
      Value *V = VMap.lookup(SI->getCondition());
393
19.8k
      Cond = dyn_cast_or_null<ConstantInt>(V);
394
19.8k
    }
395
19.8k
    if (Cond) {     // Constant fold to uncond branch!
396
16.1k
      SwitchInst::ConstCaseHandle Case = *SI->findCaseValue(Cond);
397
16.1k
      BasicBlock *Dest = const_cast<BasicBlock*>(Case.getCaseSuccessor());
398
16.1k
      VMap[OldTI] = BranchInst::Create(Dest, NewBB);
399
16.1k
      ToClone.push_back(Dest);
400
16.1k
      TerminatorDone = true;
401
16.1k
    }
402
19.8k
  }
403
1.21M
404
1.21M
  if (!TerminatorDone) {
405
1.17M
    Instruction *NewInst = OldTI->clone();
406
1.17M
    if (OldTI->hasName())
407
22
      NewInst->setName(OldTI->getName()+NameSuffix);
408
1.17M
    NewBB->getInstList().push_back(NewInst);
409
1.17M
    VMap[OldTI] = NewInst;             // Add instruction map to value.
410
1.17M
411
1.17M
    if (CodeInfo)
412
1.17M
      if (auto CS = ImmutableCallSite(OldTI))
413
12.0k
        if (CS.hasOperandBundles())
414
46
          CodeInfo->OperandBundleCallSites.push_back(NewInst);
415
1.17M
416
1.17M
    // Recursively clone any reachable successor blocks.
417
1.17M
    const Instruction *TI = BB->getTerminator();
418
1.17M
    for (const BasicBlock *Succ : successors(TI))
419
975k
      ToClone.push_back(Succ);
420
1.17M
  }
421
1.21M
422
1.21M
  if (CodeInfo) {
423
1.21M
    CodeInfo->ContainsCalls          |= hasCalls;
424
1.21M
    CodeInfo->ContainsDynamicAllocas |= hasDynamicAllocas;
425
1.21M
    CodeInfo->ContainsDynamicAllocas |= hasStaticAllocas &&
426
1.21M
      
BB != &BB->getParent()->front()34.4k
;
427
1.21M
  }
428
1.21M
}
429
430
/// This works like CloneAndPruneFunctionInto, except that it does not clone the
431
/// entire function. Instead it starts at an instruction provided by the caller
432
/// and copies (and prunes) only the code reachable from that instruction.
433
void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
434
                                     const Instruction *StartingInst,
435
                                     ValueToValueMapTy &VMap,
436
                                     bool ModuleLevelChanges,
437
                                     SmallVectorImpl<ReturnInst *> &Returns,
438
                                     const char *NameSuffix,
439
541k
                                     ClonedCodeInfo *CodeInfo) {
440
541k
  assert(NameSuffix && "NameSuffix cannot be null!");
441
541k
442
541k
  ValueMapTypeRemapper *TypeMapper = nullptr;
443
541k
  ValueMaterializer *Materializer = nullptr;
444
541k
445
#ifndef NDEBUG
446
  // If the cloning starts at the beginning of the function, verify that
447
  // the function arguments are mapped.
448
  if (!StartingInst)
449
    for (const Argument &II : OldFunc->args())
450
      assert(VMap.count(&II) && "No mapping from source argument specified!");
451
#endif
452
453
541k
  PruningFunctionCloner PFC(NewFunc, OldFunc, VMap, ModuleLevelChanges,
454
541k
                            NameSuffix, CodeInfo);
455
541k
  const BasicBlock *StartingBB;
456
541k
  if (StartingInst)
457
541k
    StartingBB = StartingInst->getParent();
458
1
  else {
459
1
    StartingBB = &OldFunc->getEntryBlock();
460
1
    StartingInst = &StartingBB->front();
461
1
  }
462
541k
463
541k
  // Clone the entry block, and anything recursively reachable from it.
464
541k
  std::vector<const BasicBlock*> CloneWorklist;
465
541k
  PFC.CloneBlock(StartingBB, StartingInst->getIterator(), CloneWorklist);
466
1.55M
  while (!CloneWorklist.empty()) {
467
1.01M
    const BasicBlock *BB = CloneWorklist.back();
468
1.01M
    CloneWorklist.pop_back();
469
1.01M
    PFC.CloneBlock(BB, BB->begin(), CloneWorklist);
470
1.01M
  }
471
541k
472
541k
  // Loop over all of the basic blocks in the old function.  If the block was
473
541k
  // reachable, we have cloned it and the old block is now in the value map:
474
541k
  // insert it into the new function in the right order.  If not, ignore it.
475
541k
  //
476
541k
  // Defer PHI resolution until rest of function is resolved.
477
541k
  SmallVector<const PHINode*, 16> PHIToResolve;
478
1.33M
  for (const BasicBlock &BI : *OldFunc) {
479
1.33M
    Value *V = VMap.lookup(&BI);
480
1.33M
    BasicBlock *NewBB = cast_or_null<BasicBlock>(V);
481
1.33M
    if (!NewBB) 
continue118k
; // Dead block.
482
1.21M
483
1.21M
    // Add the new block to the new function.
484
1.21M
    NewFunc->getBasicBlockList().push_back(NewBB);
485
1.21M
486
1.21M
    // Handle PHI nodes specially, as we have to remove references to dead
487
1.21M
    // blocks.
488
1.21M
    for (const PHINode &PN : BI.phis()) {
489
180k
      // PHI nodes may have been remapped to non-PHI nodes by the caller or
490
180k
      // during the cloning process.
491
180k
      if (isa<PHINode>(VMap[&PN]))
492
180k
        PHIToResolve.push_back(&PN);
493
0
      else
494
0
        break;
495
180k
    }
496
1.21M
497
1.21M
    // Finally, remap the terminator instructions, as those can't be remapped
498
1.21M
    // until all BBs are mapped.
499
1.21M
    RemapInstruction(NewBB->getTerminator(), VMap,
500
1.21M
                     ModuleLevelChanges ? 
RF_None0
: RF_NoModuleLevelChanges,
501
1.21M
                     TypeMapper, Materializer);
502
1.21M
  }
503
541k
504
541k
  // Defer PHI resolution until rest of function is resolved, PHI resolution
505
541k
  // requires the CFG to be up-to-date.
506
675k
  for (unsigned phino = 0, e = PHIToResolve.size(); phino != e; ) {
507
134k
    const PHINode *OPN = PHIToResolve[phino];
508
134k
    unsigned NumPreds = OPN->getNumIncomingValues();
509
134k
    const BasicBlock *OldBB = OPN->getParent();
510
134k
    BasicBlock *NewBB = cast<BasicBlock>(VMap[OldBB]);
511
134k
512
134k
    // Map operands for blocks that are live and remove operands for blocks
513
134k
    // that are dead.
514
314k
    for (; phino != PHIToResolve.size() &&
515
314k
         
PHIToResolve[phino]->getParent() == OldBB232k
;
++phino180k
) {
516
180k
      OPN = PHIToResolve[phino];
517
180k
      PHINode *PN = cast<PHINode>(VMap[OPN]);
518
628k
      for (unsigned pred = 0, e = NumPreds; pred != e; 
++pred447k
) {
519
447k
        Value *V = VMap.lookup(PN->getIncomingBlock(pred));
520
447k
        if (BasicBlock *MappedBlock = cast_or_null<BasicBlock>(V)) {
521
414k
          Value *InVal = MapValue(PN->getIncomingValue(pred),
522
414k
                                  VMap,
523
414k
                        ModuleLevelChanges ? 
RF_None0
: RF_NoModuleLevelChanges);
524
414k
          assert(InVal && "Unknown input value?");
525
414k
          PN->setIncomingValue(pred, InVal);
526
414k
          PN->setIncomingBlock(pred, MappedBlock);
527
414k
        } else {
528
33.4k
          PN->removeIncomingValue(pred, false);
529
33.4k
          --pred;  // Revisit the next entry.
530
33.4k
          --e;
531
33.4k
        }
532
447k
      }
533
180k
    }
534
134k
535
134k
    // The loop above has removed PHI entries for those blocks that are dead
536
134k
    // and has updated others.  However, if a block is live (i.e. copied over)
537
134k
    // but its terminator has been changed to not go to this block, then our
538
134k
    // phi nodes will have invalid entries.  Update the PHI nodes in this
539
134k
    // case.
540
134k
    PHINode *PN = cast<PHINode>(NewBB->begin());
541
134k
    NumPreds = pred_size(NewBB);
542
134k
    if (NumPreds != PN->getNumIncomingValues()) {
543
2.60k
      assert(NumPreds < PN->getNumIncomingValues());
544
2.60k
      // Count how many times each predecessor comes to this block.
545
2.60k
      std::map<BasicBlock*, unsigned> PredCount;
546
2.60k
      for (pred_iterator PI = pred_begin(NewBB), E = pred_end(NewBB);
547
7.78k
           PI != E; 
++PI5.18k
)
548
5.18k
        --PredCount[*PI];
549
2.60k
550
2.60k
      // Figure out how many entries to remove from each PHI.
551
10.5k
      for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; 
++i7.96k
)
552
7.96k
        ++PredCount[PN->getIncomingBlock(i)];
553
2.60k
554
2.60k
      // At this point, the excess predecessor entries are positive in the
555
2.60k
      // map.  Loop over all of the PHIs and remove excess predecessor
556
2.60k
      // entries.
557
2.60k
      BasicBlock::iterator I = NewBB->begin();
558
5.33k
      for (; (PN = dyn_cast<PHINode>(I)); 
++I2.73k
) {
559
8.46k
        for (const auto &PCI : PredCount) {
560
8.46k
          BasicBlock *Pred = PCI.first;
561
11.4k
          for (unsigned NumToRemove = PCI.second; NumToRemove; 
--NumToRemove2.93k
)
562
2.93k
            PN->removeIncomingValue(Pred, false);
563
8.46k
        }
564
2.73k
      }
565
2.60k
    }
566
134k
567
134k
    // If the loops above have made these phi nodes have 0 or 1 operand,
568
134k
    // replace them with undef or the input value.  We must do this for
569
134k
    // correctness, because 0-operand phis are not valid.
570
134k
    PN = cast<PHINode>(NewBB->begin());
571
134k
    if (PN->getNumIncomingValues() == 0) {
572
0
      BasicBlock::iterator I = NewBB->begin();
573
0
      BasicBlock::const_iterator OldI = OldBB->begin();
574
0
      while ((PN = dyn_cast<PHINode>(I++))) {
575
0
        Value *NV = UndefValue::get(PN->getType());
576
0
        PN->replaceAllUsesWith(NV);
577
0
        assert(VMap[&*OldI] == PN && "VMap mismatch");
578
0
        VMap[&*OldI] = NV;
579
0
        PN->eraseFromParent();
580
0
        ++OldI;
581
0
      }
582
0
    }
583
134k
  }
584
541k
585
541k
  // Make a second pass over the PHINodes now that all of them have been
586
541k
  // remapped into the new function, simplifying the PHINode and performing any
587
541k
  // recursive simplifications exposed. This will transparently update the
588
541k
  // WeakTrackingVH in the VMap. Notably, we rely on that so that if we coalesce
589
541k
  // two PHINodes, the iteration over the old PHIs remains valid, and the
590
541k
  // mapping will just map us to the new node (which may not even be a PHI
591
541k
  // node).
592
541k
  const DataLayout &DL = NewFunc->getParent()->getDataLayout();
593
541k
  SmallSetVector<const Value *, 8> Worklist;
594
721k
  for (unsigned Idx = 0, Size = PHIToResolve.size(); Idx != Size; 
++Idx180k
)
595
180k
    if (isa<PHINode>(VMap[PHIToResolve[Idx]]))
596
180k
      Worklist.insert(PHIToResolve[Idx]);
597
541k
598
541k
  // Note that we must test the size on each iteration, the worklist can grow.
599
727k
  for (unsigned Idx = 0; Idx != Worklist.size(); 
++Idx186k
) {
600
186k
    const Value *OrigV = Worklist[Idx];
601
186k
    auto *I = dyn_cast_or_null<Instruction>(VMap.lookup(OrigV));
602
186k
    if (!I)
603
253
      continue;
604
186k
605
186k
    // Skip over non-intrinsic callsites, we don't want to remove any nodes from
606
186k
    // the CGSCC.
607
186k
    CallSite CS = CallSite(I);
608
186k
    if (CS && 
CS.getCalledFunction()185
&&
!CS.getCalledFunction()->isIntrinsic()143
)
609
120
      continue;
610
186k
611
186k
    // See if this instruction simplifies.
612
186k
    Value *SimpleV = SimplifyInstruction(I, DL);
613
186k
    if (!SimpleV)
614
181k
      continue;
615
5.34k
616
5.34k
    // Stash away all the uses of the old instruction so we can check them for
617
5.34k
    // recursive simplifications after a RAUW. This is cheaper than checking all
618
5.34k
    // uses of To on the recursive step in most cases.
619
5.34k
    for (const User *U : OrigV->users())
620
7.18k
      Worklist.insert(cast<Instruction>(U));
621
5.34k
622
5.34k
    // Replace the instruction with its simplified value.
623
5.34k
    I->replaceAllUsesWith(SimpleV);
624
5.34k
625
5.34k
    // If the original instruction had no side effects, remove it.
626
5.34k
    if (isInstructionTriviallyDead(I))
627
5.34k
      I->eraseFromParent();
628
0
    else
629
0
      VMap[OrigV] = I;
630
5.34k
  }
631
541k
632
541k
  // Now that the inlined function body has been fully constructed, go through
633
541k
  // and zap unconditional fall-through branches. This happens all the time when
634
541k
  // specializing code: code specialization turns conditional branches into
635
541k
  // uncond branches, and this code folds them.
636
541k
  Function::iterator Begin = cast<BasicBlock>(VMap[StartingBB])->getIterator();
637
541k
  Function::iterator I = Begin;
638
1.75M
  while (I != NewFunc->end()) {
639
1.21M
    // We need to simplify conditional branches and switches with a constant
640
1.21M
    // operand. We try to prune these out when cloning, but if the
641
1.21M
    // simplification required looking through PHI nodes, those are only
642
1.21M
    // available after forming the full basic block. That may leave some here,
643
1.21M
    // and we still want to prune the dead code as early as possible.
644
1.21M
    //
645
1.21M
    // Do the folding before we check if the block is dead since we want code
646
1.21M
    // like
647
1.21M
    //  bb:
648
1.21M
    //    br i1 undef, label %bb, label %bb
649
1.21M
    // to be simplified to
650
1.21M
    //  bb:
651
1.21M
    //    br label %bb
652
1.21M
    // before we call I->getSinglePredecessor().
653
1.21M
    ConstantFoldTerminator(&*I);
654
1.21M
655
1.21M
    // Check if this block has become dead during inlining or other
656
1.21M
    // simplifications. Note that the first block will appear dead, as it has
657
1.21M
    // not yet been wired up properly.
658
1.21M
    if (I != Begin && 
(637k
pred_begin(&*I) == pred_end(&*I)637k
||
659
637k
                       
I->getSinglePredecessor() == &*I637k
)) {
660
44
      BasicBlock *DeadBB = &*I++;
661
44
      DeleteDeadBlock(DeadBB);
662
44
      continue;
663
44
    }
664
1.21M
665
1.21M
    BranchInst *BI = dyn_cast<BranchInst>(I->getTerminator());
666
1.21M
    if (!BI || 
BI->isConditional()627k
)
{ ++I; continue; }932k
667
285k
668
285k
    BasicBlock *Dest = BI->getSuccessor(0);
669
285k
    if (!Dest->getSinglePredecessor()) {
670
242k
      ++I; continue;
671
242k
    }
672
43.6k
673
43.6k
    // We shouldn't be able to get single-entry PHI nodes here, as instsimplify
674
43.6k
    // above should have zapped all of them..
675
43.6k
    assert(!isa<PHINode>(Dest->begin()));
676
43.6k
677
43.6k
    // We know all single-entry PHI nodes in the inlined function have been
678
43.6k
    // removed, so we just need to splice the blocks.
679
43.6k
    BI->eraseFromParent();
680
43.6k
681
43.6k
    // Make all PHI nodes that referred to Dest now refer to I as their source.
682
43.6k
    Dest->replaceAllUsesWith(&*I);
683
43.6k
684
43.6k
    // Move all the instructions in the succ to the pred.
685
43.6k
    I->getInstList().splice(I->end(), Dest->getInstList());
686
43.6k
687
43.6k
    // Remove the dest block.
688
43.6k
    Dest->eraseFromParent();
689
43.6k
690
43.6k
    // Do not increment I, iteratively merge all things this block branches to.
691
43.6k
  }
692
541k
693
541k
  // Make a final pass over the basic blocks from the old function to gather
694
541k
  // any return instructions which survived folding. We have to do this here
695
541k
  // because we can iteratively remove and merge returns above.
696
541k
  for (Function::iterator I = cast<BasicBlock>(VMap[StartingBB])->getIterator(),
697
541k
                          E = NewFunc->end();
698
1.71M
       I != E; 
++I1.17M
)
699
1.17M
    if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator()))
700
541k
      Returns.push_back(RI);
701
541k
}
702
703
704
/// This works exactly like CloneFunctionInto,
705
/// except that it does some simple constant prop and DCE on the fly.  The
706
/// effect of this is to copy significantly less code in cases where (for
707
/// example) a function call with constant arguments is inlined, and those
708
/// constant arguments cause a significant amount of code in the callee to be
709
/// dead.  Since this doesn't produce an exact copy of the input, it can't be
710
/// used for things like CloneFunction or CloneModule.
711
void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
712
                                     ValueToValueMapTy &VMap,
713
                                     bool ModuleLevelChanges,
714
                                     SmallVectorImpl<ReturnInst*> &Returns,
715
                                     const char *NameSuffix,
716
                                     ClonedCodeInfo *CodeInfo,
717
541k
                                     Instruction *TheCall) {
718
541k
  CloneAndPruneIntoFromInst(NewFunc, OldFunc, &OldFunc->front().front(), VMap,
719
541k
                            ModuleLevelChanges, Returns, NameSuffix, CodeInfo);
720
541k
}
721
722
/// Remaps instructions in \p Blocks using the mapping in \p VMap.
723
void llvm::remapInstructionsInBlocks(
724
227
    const SmallVectorImpl<BasicBlock *> &Blocks, ValueToValueMapTy &VMap) {
725
227
  // Rewrite the code to refer to itself.
726
227
  for (auto *BB : Blocks)
727
948
    for (auto &Inst : *BB)
728
6.40k
      RemapInstruction(&Inst, VMap,
729
6.40k
                       RF_NoModuleLevelChanges | RF_IgnoreMissingLocals);
730
227
}
731
732
/// Clones a loop \p OrigLoop.  Returns the loop and the blocks in \p
733
/// Blocks.
734
///
735
/// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
736
/// \p LoopDomBB.  Insert the new blocks before block specified in \p Before.
737
Loop *llvm::cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
738
                                   Loop *OrigLoop, ValueToValueMapTy &VMap,
739
                                   const Twine &NameSuffix, LoopInfo *LI,
740
                                   DominatorTree *DT,
741
75
                                   SmallVectorImpl<BasicBlock *> &Blocks) {
742
75
  Function *F = OrigLoop->getHeader()->getParent();
743
75
  Loop *ParentLoop = OrigLoop->getParentLoop();
744
75
  DenseMap<Loop *, Loop *> LMap;
745
75
746
75
  Loop *NewLoop = LI->AllocateLoop();
747
75
  LMap[OrigLoop] = NewLoop;
748
75
  if (ParentLoop)
749
7
    ParentLoop->addChildLoop(NewLoop);
750
68
  else
751
68
    LI->addTopLevelLoop(NewLoop);
752
75
753
75
  BasicBlock *OrigPH = OrigLoop->getLoopPreheader();
754
75
  assert(OrigPH && "No preheader");
755
75
  BasicBlock *NewPH = CloneBasicBlock(OrigPH, VMap, NameSuffix, F);
756
75
  // To rename the loop PHIs.
757
75
  VMap[OrigPH] = NewPH;
758
75
  Blocks.push_back(NewPH);
759
75
760
75
  // Update LoopInfo.
761
75
  if (ParentLoop)
762
7
    ParentLoop->addBasicBlockToLoop(NewPH, *LI);
763
75
764
75
  // Update DominatorTree.
765
75
  DT->addNewBlock(NewPH, LoopDomBB);
766
75
767
76
  for (Loop *CurLoop : OrigLoop->getLoopsInPreorder()) {
768
76
    Loop *&NewLoop = LMap[CurLoop];
769
76
    if (!NewLoop) {
770
1
      NewLoop = LI->AllocateLoop();
771
1
772
1
      // Establish the parent/child relationship.
773
1
      Loop *OrigParent = CurLoop->getParentLoop();
774
1
      assert(OrigParent && "Could not find the original parent loop");
775
1
      Loop *NewParentLoop = LMap[OrigParent];
776
1
      assert(NewParentLoop && "Could not find the new parent loop");
777
1
778
1
      NewParentLoop->addChildLoop(NewLoop);
779
1
    }
780
76
  }
781
75
782
137
  for (BasicBlock *BB : OrigLoop->getBlocks()) {
783
137
    Loop *CurLoop = LI->getLoopFor(BB);
784
137
    Loop *&NewLoop = LMap[CurLoop];
785
137
    assert(NewLoop && "Expecting new loop to be allocated");
786
137
787
137
    BasicBlock *NewBB = CloneBasicBlock(BB, VMap, NameSuffix, F);
788
137
    VMap[BB] = NewBB;
789
137
790
137
    // Update LoopInfo.
791
137
    NewLoop->addBasicBlockToLoop(NewBB, *LI);
792
137
    if (BB == CurLoop->getHeader())
793
76
      NewLoop->moveToHeader(NewBB);
794
137
795
137
    // Add DominatorTree node. After seeing all blocks, update to correct
796
137
    // IDom.
797
137
    DT->addNewBlock(NewBB, NewPH);
798
137
799
137
    Blocks.push_back(NewBB);
800
137
  }
801
75
802
137
  for (BasicBlock *BB : OrigLoop->getBlocks()) {
803
137
    // Update DominatorTree.
804
137
    BasicBlock *IDomBB = DT->getNode(BB)->getIDom()->getBlock();
805
137
    DT->changeImmediateDominator(cast<BasicBlock>(VMap[BB]),
806
137
                                 cast<BasicBlock>(VMap[IDomBB]));
807
137
  }
808
75
809
75
  // Move them physically from the end of the block list.
810
75
  F->getBasicBlockList().splice(Before->getIterator(), F->getBasicBlockList(),
811
75
                                NewPH);
812
75
  F->getBasicBlockList().splice(Before->getIterator(), F->getBasicBlockList(),
813
75
                                NewLoop->getHeader()->getIterator(), F->end());
814
75
815
75
  return NewLoop;
816
75
}
817
818
/// Duplicate non-Phi instructions from the beginning of block up to
819
/// StopAt instruction into a split block between BB and its predecessor.
820
BasicBlock *llvm::DuplicateInstructionsInSplitBetween(
821
    BasicBlock *BB, BasicBlock *PredBB, Instruction *StopAt,
822
535
    ValueToValueMapTy &ValueMapping, DomTreeUpdater &DTU) {
823
535
824
535
  assert(count(successors(PredBB), BB) == 1 &&
825
535
         "There must be a single edge between PredBB and BB!");
826
535
  // We are going to have to map operands from the original BB block to the new
827
535
  // copy of the block 'NewBB'.  If there are PHI nodes in BB, evaluate them to
828
535
  // account for entry from PredBB.
829
535
  BasicBlock::iterator BI = BB->begin();
830
739
  for (; PHINode *PN = dyn_cast<PHINode>(BI); 
++BI204
)
831
204
    ValueMapping[PN] = PN->getIncomingValueForBlock(PredBB);
832
535
833
535
  BasicBlock *NewBB = SplitEdge(PredBB, BB);
834
535
  NewBB->setName(PredBB->getName() + ".split");
835
535
  Instruction *NewTerm = NewBB->getTerminator();
836
535
837
535
  // FIXME: SplitEdge does not yet take a DTU, so we include the split edge
838
535
  //        in the update set here.
839
535
  DTU.applyUpdates({{DominatorTree::Delete, PredBB, BB},
840
535
                    {DominatorTree::Insert, PredBB, NewBB},
841
535
                    {DominatorTree::Insert, NewBB, BB}});
842
535
843
535
  // Clone the non-phi instructions of BB into NewBB, keeping track of the
844
535
  // mapping and using it to remap operands in the cloned instructions.
845
535
  // Stop once we see the terminator too. This covers the case where BB's
846
535
  // terminator gets replaced and StopAt == BB's terminator.
847
1.28k
  for (; StopAt != &*BI && 
BB->getTerminator() != &*BI748
;
++BI747
) {
848
747
    Instruction *New = BI->clone();
849
747
    New->setName(BI->getName());
850
747
    New->insertBefore(NewTerm);
851
747
    ValueMapping[&*BI] = New;
852
747
853
747
    // Remap operands to patch up intra-block references.
854
3.14k
    for (unsigned i = 0, e = New->getNumOperands(); i != e; 
++i2.40k
)
855
2.40k
      if (Instruction *Inst = dyn_cast<Instruction>(New->getOperand(i))) {
856
890
        auto I = ValueMapping.find(Inst);
857
890
        if (I != ValueMapping.end())
858
340
          New->setOperand(i, I->second);
859
890
      }
860
747
  }
861
535
862
535
  return NewBB;
863
535
}