File: | build/llvm-toolchain-snapshot-16~++20220904122748+c444af1c20b3/llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp |
Warning: | line 384, column 7 Called C++ object pointer is null |
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1 | //===- ObjCARCContract.cpp - ObjC ARC Optimization ------------------------===// | ||||||
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 | /// \file | ||||||
9 | /// This file defines late ObjC ARC optimizations. ARC stands for Automatic | ||||||
10 | /// Reference Counting and is a system for managing reference counts for objects | ||||||
11 | /// in Objective C. | ||||||
12 | /// | ||||||
13 | /// This specific file mainly deals with ``contracting'' multiple lower level | ||||||
14 | /// operations into singular higher level operations through pattern matching. | ||||||
15 | /// | ||||||
16 | /// WARNING: This file knows about certain library functions. It recognizes them | ||||||
17 | /// by name, and hardwires knowledge of their semantics. | ||||||
18 | /// | ||||||
19 | /// WARNING: This file knows about how certain Objective-C library functions are | ||||||
20 | /// used. Naive LLVM IR transformations which would otherwise be | ||||||
21 | /// behavior-preserving may break these assumptions. | ||||||
22 | /// | ||||||
23 | //===----------------------------------------------------------------------===// | ||||||
24 | |||||||
25 | // TODO: ObjCARCContract could insert PHI nodes when uses aren't | ||||||
26 | // dominated by single calls. | ||||||
27 | |||||||
28 | #include "ARCRuntimeEntryPoints.h" | ||||||
29 | #include "DependencyAnalysis.h" | ||||||
30 | #include "ObjCARC.h" | ||||||
31 | #include "ProvenanceAnalysis.h" | ||||||
32 | #include "llvm/ADT/Statistic.h" | ||||||
33 | #include "llvm/Analysis/AliasAnalysis.h" | ||||||
34 | #include "llvm/Analysis/EHPersonalities.h" | ||||||
35 | #include "llvm/Analysis/ObjCARCUtil.h" | ||||||
36 | #include "llvm/IR/Dominators.h" | ||||||
37 | #include "llvm/IR/InlineAsm.h" | ||||||
38 | #include "llvm/IR/InstIterator.h" | ||||||
39 | #include "llvm/IR/Operator.h" | ||||||
40 | #include "llvm/IR/PassManager.h" | ||||||
41 | #include "llvm/InitializePasses.h" | ||||||
42 | #include "llvm/Support/CommandLine.h" | ||||||
43 | #include "llvm/Support/Debug.h" | ||||||
44 | #include "llvm/Support/raw_ostream.h" | ||||||
45 | #include "llvm/Transforms/ObjCARC.h" | ||||||
46 | |||||||
47 | using namespace llvm; | ||||||
48 | using namespace llvm::objcarc; | ||||||
49 | |||||||
50 | #define DEBUG_TYPE"objc-arc-contract" "objc-arc-contract" | ||||||
51 | |||||||
52 | STATISTIC(NumPeeps, "Number of calls peephole-optimized")static llvm::Statistic NumPeeps = {"objc-arc-contract", "NumPeeps" , "Number of calls peephole-optimized"}; | ||||||
53 | STATISTIC(NumStoreStrongs, "Number objc_storeStrong calls formed")static llvm::Statistic NumStoreStrongs = {"objc-arc-contract" , "NumStoreStrongs", "Number objc_storeStrong calls formed"}; | ||||||
54 | |||||||
55 | //===----------------------------------------------------------------------===// | ||||||
56 | // Declarations | ||||||
57 | //===----------------------------------------------------------------------===// | ||||||
58 | |||||||
59 | namespace { | ||||||
60 | /// Late ARC optimizations | ||||||
61 | /// | ||||||
62 | /// These change the IR in a way that makes it difficult to be analyzed by | ||||||
63 | /// ObjCARCOpt, so it's run late. | ||||||
64 | |||||||
65 | class ObjCARCContract { | ||||||
66 | bool Changed; | ||||||
67 | bool CFGChanged; | ||||||
68 | AAResults *AA; | ||||||
69 | DominatorTree *DT; | ||||||
70 | ProvenanceAnalysis PA; | ||||||
71 | ARCRuntimeEntryPoints EP; | ||||||
72 | BundledRetainClaimRVs *BundledInsts = nullptr; | ||||||
73 | |||||||
74 | /// The inline asm string to insert between calls and RetainRV calls to make | ||||||
75 | /// the optimization work on targets which need it. | ||||||
76 | const MDString *RVInstMarker; | ||||||
77 | |||||||
78 | /// The set of inserted objc_storeStrong calls. If at the end of walking the | ||||||
79 | /// function we have found no alloca instructions, these calls can be marked | ||||||
80 | /// "tail". | ||||||
81 | SmallPtrSet<CallInst *, 8> StoreStrongCalls; | ||||||
82 | |||||||
83 | /// Returns true if we eliminated Inst. | ||||||
84 | bool tryToPeepholeInstruction( | ||||||
85 | Function &F, Instruction *Inst, inst_iterator &Iter, | ||||||
86 | bool &TailOkForStoreStrong, | ||||||
87 | const DenseMap<BasicBlock *, ColorVector> &BlockColors); | ||||||
88 | |||||||
89 | bool optimizeRetainCall(Function &F, Instruction *Retain); | ||||||
90 | |||||||
91 | bool contractAutorelease(Function &F, Instruction *Autorelease, | ||||||
92 | ARCInstKind Class); | ||||||
93 | |||||||
94 | void tryToContractReleaseIntoStoreStrong( | ||||||
95 | Instruction *Release, inst_iterator &Iter, | ||||||
96 | const DenseMap<BasicBlock *, ColorVector> &BlockColors); | ||||||
97 | |||||||
98 | public: | ||||||
99 | bool init(Module &M); | ||||||
100 | bool run(Function &F, AAResults *AA, DominatorTree *DT); | ||||||
101 | bool hasCFGChanged() const { return CFGChanged; } | ||||||
102 | }; | ||||||
103 | |||||||
104 | class ObjCARCContractLegacyPass : public FunctionPass { | ||||||
105 | public: | ||||||
106 | void getAnalysisUsage(AnalysisUsage &AU) const override; | ||||||
107 | bool runOnFunction(Function &F) override; | ||||||
108 | |||||||
109 | static char ID; | ||||||
110 | ObjCARCContractLegacyPass() : FunctionPass(ID) { | ||||||
111 | initializeObjCARCContractLegacyPassPass(*PassRegistry::getPassRegistry()); | ||||||
112 | } | ||||||
113 | }; | ||||||
114 | } | ||||||
115 | |||||||
116 | //===----------------------------------------------------------------------===// | ||||||
117 | // Implementation | ||||||
118 | //===----------------------------------------------------------------------===// | ||||||
119 | |||||||
120 | /// Turn objc_retain into objc_retainAutoreleasedReturnValue if the operand is a | ||||||
121 | /// return value. We do this late so we do not disrupt the dataflow analysis in | ||||||
122 | /// ObjCARCOpt. | ||||||
123 | bool ObjCARCContract::optimizeRetainCall(Function &F, Instruction *Retain) { | ||||||
124 | const auto *Call = dyn_cast<CallBase>(GetArgRCIdentityRoot(Retain)); | ||||||
125 | if (!Call) | ||||||
126 | return false; | ||||||
127 | if (Call->getParent() != Retain->getParent()) | ||||||
128 | return false; | ||||||
129 | |||||||
130 | // Check that the call is next to the retain. | ||||||
131 | BasicBlock::const_iterator I = ++Call->getIterator(); | ||||||
132 | while (IsNoopInstruction(&*I)) | ||||||
133 | ++I; | ||||||
134 | if (&*I != Retain) | ||||||
135 | return false; | ||||||
136 | |||||||
137 | // Turn it to an objc_retainAutoreleasedReturnValue. | ||||||
138 | Changed = true; | ||||||
139 | ++NumPeeps; | ||||||
140 | |||||||
141 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Transforming objc_retain => " "objc_retainAutoreleasedReturnValue since the operand is a " "return value.\nOld: " << *Retain << "\n"; } } while (false) | ||||||
142 | dbgs() << "Transforming objc_retain => "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Transforming objc_retain => " "objc_retainAutoreleasedReturnValue since the operand is a " "return value.\nOld: " << *Retain << "\n"; } } while (false) | ||||||
143 | "objc_retainAutoreleasedReturnValue since the operand is a "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Transforming objc_retain => " "objc_retainAutoreleasedReturnValue since the operand is a " "return value.\nOld: " << *Retain << "\n"; } } while (false) | ||||||
144 | "return value.\nOld: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Transforming objc_retain => " "objc_retainAutoreleasedReturnValue since the operand is a " "return value.\nOld: " << *Retain << "\n"; } } while (false) | ||||||
145 | << *Retain << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Transforming objc_retain => " "objc_retainAutoreleasedReturnValue since the operand is a " "return value.\nOld: " << *Retain << "\n"; } } while (false); | ||||||
146 | |||||||
147 | // We do not have to worry about tail calls/does not throw since | ||||||
148 | // retain/retainRV have the same properties. | ||||||
149 | Function *Decl = EP.get(ARCRuntimeEntryPointKind::RetainRV); | ||||||
150 | cast<CallInst>(Retain)->setCalledFunction(Decl); | ||||||
151 | |||||||
152 | LLVM_DEBUG(dbgs() << "New: " << *Retain << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "New: " << *Retain << "\n"; } } while (false); | ||||||
153 | return true; | ||||||
154 | } | ||||||
155 | |||||||
156 | /// Merge an autorelease with a retain into a fused call. | ||||||
157 | bool ObjCARCContract::contractAutorelease(Function &F, Instruction *Autorelease, | ||||||
158 | ARCInstKind Class) { | ||||||
159 | const Value *Arg = GetArgRCIdentityRoot(Autorelease); | ||||||
160 | |||||||
161 | // Check that there are no instructions between the retain and the autorelease | ||||||
162 | // (such as an autorelease_pop) which may change the count. | ||||||
163 | DependenceKind DK = Class == ARCInstKind::AutoreleaseRV | ||||||
164 | ? RetainAutoreleaseRVDep | ||||||
165 | : RetainAutoreleaseDep; | ||||||
166 | auto *Retain = dyn_cast_or_null<CallInst>( | ||||||
167 | findSingleDependency(DK, Arg, Autorelease->getParent(), Autorelease, PA)); | ||||||
168 | |||||||
169 | if (!Retain || GetBasicARCInstKind(Retain) != ARCInstKind::Retain || | ||||||
170 | GetArgRCIdentityRoot(Retain) != Arg) | ||||||
171 | return false; | ||||||
172 | |||||||
173 | Changed = true; | ||||||
174 | ++NumPeeps; | ||||||
175 | |||||||
176 | LLVM_DEBUG(dbgs() << " Fusing retain/autorelease!\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " Fusing retain/autorelease!\n" " Autorelease:" << *Autorelease << "\n" " Retain: " << *Retain << "\n"; } } while (false) | ||||||
177 | " Autorelease:"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " Fusing retain/autorelease!\n" " Autorelease:" << *Autorelease << "\n" " Retain: " << *Retain << "\n"; } } while (false) | ||||||
178 | << *Autoreleasedo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " Fusing retain/autorelease!\n" " Autorelease:" << *Autorelease << "\n" " Retain: " << *Retain << "\n"; } } while (false) | ||||||
179 | << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " Fusing retain/autorelease!\n" " Autorelease:" << *Autorelease << "\n" " Retain: " << *Retain << "\n"; } } while (false) | ||||||
180 | " Retain: "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " Fusing retain/autorelease!\n" " Autorelease:" << *Autorelease << "\n" " Retain: " << *Retain << "\n"; } } while (false) | ||||||
181 | << *Retain << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " Fusing retain/autorelease!\n" " Autorelease:" << *Autorelease << "\n" " Retain: " << *Retain << "\n"; } } while (false); | ||||||
182 | |||||||
183 | Function *Decl = EP.get(Class == ARCInstKind::AutoreleaseRV | ||||||
184 | ? ARCRuntimeEntryPointKind::RetainAutoreleaseRV | ||||||
185 | : ARCRuntimeEntryPointKind::RetainAutorelease); | ||||||
186 | Retain->setCalledFunction(Decl); | ||||||
187 | |||||||
188 | LLVM_DEBUG(dbgs() << " New RetainAutorelease: " << *Retain << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << " New RetainAutorelease: " << *Retain << "\n"; } } while (false); | ||||||
189 | |||||||
190 | EraseInstruction(Autorelease); | ||||||
191 | return true; | ||||||
192 | } | ||||||
193 | |||||||
194 | static StoreInst *findSafeStoreForStoreStrongContraction(LoadInst *Load, | ||||||
195 | Instruction *Release, | ||||||
196 | ProvenanceAnalysis &PA, | ||||||
197 | AAResults *AA) { | ||||||
198 | StoreInst *Store = nullptr; | ||||||
199 | bool SawRelease = false; | ||||||
200 | |||||||
201 | // Get the location associated with Load. | ||||||
202 | MemoryLocation Loc = MemoryLocation::get(Load); | ||||||
203 | auto *LocPtr = Loc.Ptr->stripPointerCasts(); | ||||||
204 | |||||||
205 | // Walk down to find the store and the release, which may be in either order. | ||||||
206 | for (auto I = std::next(BasicBlock::iterator(Load)), | ||||||
207 | E = Load->getParent()->end(); | ||||||
208 | I != E; ++I) { | ||||||
209 | // If we found the store we were looking for and saw the release, | ||||||
210 | // break. There is no more work to be done. | ||||||
211 | if (Store
| ||||||
212 | break; | ||||||
213 | |||||||
214 | // Now we know that we have not seen either the store or the release. If I | ||||||
215 | // is the release, mark that we saw the release and continue. | ||||||
216 | Instruction *Inst = &*I; | ||||||
217 | if (Inst == Release) { | ||||||
218 | SawRelease = true; | ||||||
219 | continue; | ||||||
220 | } | ||||||
221 | |||||||
222 | // Otherwise, we check if Inst is a "good" store. Grab the instruction class | ||||||
223 | // of Inst. | ||||||
224 | ARCInstKind Class = GetBasicARCInstKind(Inst); | ||||||
225 | |||||||
226 | // If we have seen the store, but not the release... | ||||||
227 | if (Store
| ||||||
228 | // We need to make sure that it is safe to move the release from its | ||||||
229 | // current position to the store. This implies proving that any | ||||||
230 | // instruction in between Store and the Release conservatively can not use | ||||||
231 | // the RCIdentityRoot of Release. If we can prove we can ignore Inst, so | ||||||
232 | // continue... | ||||||
233 | if (!CanUse(Inst, Load, PA, Class)) { | ||||||
234 | continue; | ||||||
235 | } | ||||||
236 | |||||||
237 | // Otherwise, be conservative and return nullptr. | ||||||
238 | return nullptr; | ||||||
239 | } | ||||||
240 | |||||||
241 | // Ok, now we know we have not seen a store yet. | ||||||
242 | |||||||
243 | // If Inst is a retain, we don't care about it as it doesn't prevent moving | ||||||
244 | // the load to the store. | ||||||
245 | // | ||||||
246 | // TODO: This is one area where the optimization could be made more | ||||||
247 | // aggressive. | ||||||
248 | if (IsRetain(Class)) | ||||||
249 | continue; | ||||||
250 | |||||||
251 | // See if Inst can write to our load location, if it can not, just ignore | ||||||
252 | // the instruction. | ||||||
253 | if (!isModSet(AA->getModRefInfo(Inst, Loc))) | ||||||
254 | continue; | ||||||
255 | |||||||
256 | Store = dyn_cast<StoreInst>(Inst); | ||||||
257 | |||||||
258 | // If Inst can, then check if Inst is a simple store. If Inst is not a | ||||||
259 | // store or a store that is not simple, then we have some we do not | ||||||
260 | // understand writing to this memory implying we can not move the load | ||||||
261 | // over the write to any subsequent store that we may find. | ||||||
262 | if (!Store
| ||||||
263 | return nullptr; | ||||||
264 | |||||||
265 | // Then make sure that the pointer we are storing to is Ptr. If so, we | ||||||
266 | // found our Store! | ||||||
267 | if (Store->getPointerOperand()->stripPointerCasts() == LocPtr) | ||||||
268 | continue; | ||||||
269 | |||||||
270 | // Otherwise, we have an unknown store to some other ptr that clobbers | ||||||
271 | // Loc.Ptr. Bail! | ||||||
272 | return nullptr; | ||||||
273 | } | ||||||
274 | |||||||
275 | // If we did not find the store or did not see the release, fail. | ||||||
276 | if (!Store
| ||||||
277 | return nullptr; | ||||||
278 | |||||||
279 | // We succeeded! | ||||||
280 | return Store; | ||||||
281 | } | ||||||
282 | |||||||
283 | static Instruction * | ||||||
284 | findRetainForStoreStrongContraction(Value *New, StoreInst *Store, | ||||||
285 | Instruction *Release, | ||||||
286 | ProvenanceAnalysis &PA) { | ||||||
287 | // Walk up from the Store to find the retain. | ||||||
288 | BasicBlock::iterator I = Store->getIterator(); | ||||||
289 | BasicBlock::iterator Begin = Store->getParent()->begin(); | ||||||
290 | while (I != Begin && GetBasicARCInstKind(&*I) != ARCInstKind::Retain) { | ||||||
291 | Instruction *Inst = &*I; | ||||||
292 | |||||||
293 | // It is only safe to move the retain to the store if we can prove | ||||||
294 | // conservatively that nothing besides the release can decrement reference | ||||||
295 | // counts in between the retain and the store. | ||||||
296 | if (CanDecrementRefCount(Inst, New, PA) && Inst != Release) | ||||||
297 | return nullptr; | ||||||
298 | --I; | ||||||
299 | } | ||||||
300 | Instruction *Retain = &*I; | ||||||
301 | if (GetBasicARCInstKind(Retain) != ARCInstKind::Retain) | ||||||
302 | return nullptr; | ||||||
303 | if (GetArgRCIdentityRoot(Retain) != New) | ||||||
304 | return nullptr; | ||||||
305 | return Retain; | ||||||
306 | } | ||||||
307 | |||||||
308 | /// Attempt to merge an objc_release with a store, load, and objc_retain to form | ||||||
309 | /// an objc_storeStrong. An objc_storeStrong: | ||||||
310 | /// | ||||||
311 | /// objc_storeStrong(i8** %old_ptr, i8* new_value) | ||||||
312 | /// | ||||||
313 | /// is equivalent to the following IR sequence: | ||||||
314 | /// | ||||||
315 | /// ; Load old value. | ||||||
316 | /// %old_value = load i8** %old_ptr (1) | ||||||
317 | /// | ||||||
318 | /// ; Increment the new value and then release the old value. This must occur | ||||||
319 | /// ; in order in case old_value releases new_value in its destructor causing | ||||||
320 | /// ; us to potentially have a dangling ptr. | ||||||
321 | /// tail call i8* @objc_retain(i8* %new_value) (2) | ||||||
322 | /// tail call void @objc_release(i8* %old_value) (3) | ||||||
323 | /// | ||||||
324 | /// ; Store the new_value into old_ptr | ||||||
325 | /// store i8* %new_value, i8** %old_ptr (4) | ||||||
326 | /// | ||||||
327 | /// The safety of this optimization is based around the following | ||||||
328 | /// considerations: | ||||||
329 | /// | ||||||
330 | /// 1. We are forming the store strong at the store. Thus to perform this | ||||||
331 | /// optimization it must be safe to move the retain, load, and release to | ||||||
332 | /// (4). | ||||||
333 | /// 2. We need to make sure that any re-orderings of (1), (2), (3), (4) are | ||||||
334 | /// safe. | ||||||
335 | void ObjCARCContract::tryToContractReleaseIntoStoreStrong( | ||||||
336 | Instruction *Release, inst_iterator &Iter, | ||||||
337 | const DenseMap<BasicBlock *, ColorVector> &BlockColors) { | ||||||
338 | // See if we are releasing something that we just loaded. | ||||||
339 | auto *Load = dyn_cast<LoadInst>(GetArgRCIdentityRoot(Release)); | ||||||
340 | if (!Load
| ||||||
341 | return; | ||||||
342 | |||||||
343 | // For now, require everything to be in one basic block. | ||||||
344 | BasicBlock *BB = Release->getParent(); | ||||||
345 | if (Load->getParent() != BB) | ||||||
346 | return; | ||||||
347 | |||||||
348 | // First scan down the BB from Load, looking for a store of the RCIdentityRoot | ||||||
349 | // of Load's | ||||||
350 | StoreInst *Store = | ||||||
351 | findSafeStoreForStoreStrongContraction(Load, Release, PA, AA); | ||||||
352 | // If we fail, bail. | ||||||
353 | if (!Store
| ||||||
354 | return; | ||||||
355 | |||||||
356 | // Then find what new_value's RCIdentity Root is. | ||||||
357 | Value *New = GetRCIdentityRoot(Store->getValueOperand()); | ||||||
358 | |||||||
359 | // Then walk up the BB and look for a retain on New without any intervening | ||||||
360 | // instructions which conservatively might decrement ref counts. | ||||||
361 | Instruction *Retain = | ||||||
362 | findRetainForStoreStrongContraction(New, Store, Release, PA); | ||||||
363 | |||||||
364 | // If we fail, bail. | ||||||
365 | if (!Retain
| ||||||
366 | return; | ||||||
367 | |||||||
368 | Changed = true; | ||||||
369 | ++NumStoreStrongs; | ||||||
370 | |||||||
371 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false) | ||||||
372 | llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false) | ||||||
373 | << " Old:\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false) | ||||||
374 | << " Store: " << *Store << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false) | ||||||
375 | << " Release: " << *Release << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false) | ||||||
376 | << " Retain: " << *Retain << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false) | ||||||
377 | << " Load: " << *Load << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " Contracting retain, release into objc_storeStrong.\n" << " Old:\n" << " Store: " << *Store << "\n" << " Release: " << *Release << "\n" << " Retain: " << *Retain << "\n" << " Load: " << *Load << "\n"; } } while (false); | ||||||
378 | |||||||
379 | LLVMContext &C = Release->getContext(); | ||||||
380 | Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C)); | ||||||
381 | Type *I8XX = PointerType::getUnqual(I8X); | ||||||
382 | |||||||
383 | Value *Args[] = { Load->getPointerOperand(), New }; | ||||||
384 | if (Args[0]->getType() != I8XX) | ||||||
| |||||||
385 | Args[0] = new BitCastInst(Args[0], I8XX, "", Store); | ||||||
386 | if (Args[1]->getType() != I8X) | ||||||
387 | Args[1] = new BitCastInst(Args[1], I8X, "", Store); | ||||||
388 | Function *Decl = EP.get(ARCRuntimeEntryPointKind::StoreStrong); | ||||||
389 | CallInst *StoreStrong = | ||||||
390 | objcarc::createCallInstWithColors(Decl, Args, "", Store, BlockColors); | ||||||
391 | StoreStrong->setDoesNotThrow(); | ||||||
392 | StoreStrong->setDebugLoc(Store->getDebugLoc()); | ||||||
393 | |||||||
394 | // We can't set the tail flag yet, because we haven't yet determined | ||||||
395 | // whether there are any escaping allocas. Remember this call, so that | ||||||
396 | // we can set the tail flag once we know it's safe. | ||||||
397 | StoreStrongCalls.insert(StoreStrong); | ||||||
398 | |||||||
399 | LLVM_DEBUG(llvm::dbgs() << " New Store Strong: " << *StoreStrongdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " New Store Strong: " << *StoreStrong << "\n"; } } while (false) | ||||||
400 | << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << " New Store Strong: " << *StoreStrong << "\n"; } } while (false); | ||||||
401 | |||||||
402 | if (&*Iter == Retain) ++Iter; | ||||||
403 | if (&*Iter == Store) ++Iter; | ||||||
404 | Store->eraseFromParent(); | ||||||
405 | Release->eraseFromParent(); | ||||||
406 | EraseInstruction(Retain); | ||||||
407 | if (Load->use_empty()) | ||||||
408 | Load->eraseFromParent(); | ||||||
409 | } | ||||||
410 | |||||||
411 | bool ObjCARCContract::tryToPeepholeInstruction( | ||||||
412 | Function &F, Instruction *Inst, inst_iterator &Iter, | ||||||
413 | bool &TailOkForStoreStrongs, | ||||||
414 | const DenseMap<BasicBlock *, ColorVector> &BlockColors) { | ||||||
415 | // Only these library routines return their argument. In particular, | ||||||
416 | // objc_retainBlock does not necessarily return its argument. | ||||||
417 | ARCInstKind Class = GetBasicARCInstKind(Inst); | ||||||
418 | switch (Class) { | ||||||
419 | case ARCInstKind::FusedRetainAutorelease: | ||||||
420 | case ARCInstKind::FusedRetainAutoreleaseRV: | ||||||
421 | return false; | ||||||
422 | case ARCInstKind::Autorelease: | ||||||
423 | case ARCInstKind::AutoreleaseRV: | ||||||
424 | return contractAutorelease(F, Inst, Class); | ||||||
425 | case ARCInstKind::Retain: | ||||||
426 | // Attempt to convert retains to retainrvs if they are next to function | ||||||
427 | // calls. | ||||||
428 | if (!optimizeRetainCall(F, Inst)) | ||||||
429 | return false; | ||||||
430 | // If we succeed in our optimization, fall through. | ||||||
431 | [[fallthrough]]; | ||||||
432 | case ARCInstKind::RetainRV: | ||||||
433 | case ARCInstKind::UnsafeClaimRV: { | ||||||
434 | // Return true if this is a bundled retainRV/claimRV call, which is always | ||||||
435 | // redundant with the attachedcall in the bundle, and is going to be erased | ||||||
436 | // at the end of this pass. This avoids undoing objc-arc-expand and | ||||||
437 | // replacing uses of the retainRV/claimRV call's argument with its result. | ||||||
438 | if (BundledInsts->contains(Inst)) | ||||||
439 | return true; | ||||||
440 | |||||||
441 | // If this isn't a bundled call, and the target doesn't need a special | ||||||
442 | // inline-asm marker, we're done: return now, and undo objc-arc-expand. | ||||||
443 | if (!RVInstMarker) | ||||||
444 | return false; | ||||||
445 | |||||||
446 | // The target needs a special inline-asm marker. Insert it. | ||||||
447 | |||||||
448 | BasicBlock::iterator BBI = Inst->getIterator(); | ||||||
449 | BasicBlock *InstParent = Inst->getParent(); | ||||||
450 | |||||||
451 | // Step up to see if the call immediately precedes the RV call. | ||||||
452 | // If it's an invoke, we have to cross a block boundary. And we have | ||||||
453 | // to carefully dodge no-op instructions. | ||||||
454 | do { | ||||||
455 | if (BBI == InstParent->begin()) { | ||||||
456 | BasicBlock *Pred = InstParent->getSinglePredecessor(); | ||||||
457 | if (!Pred) | ||||||
458 | goto decline_rv_optimization; | ||||||
459 | BBI = Pred->getTerminator()->getIterator(); | ||||||
460 | break; | ||||||
461 | } | ||||||
462 | --BBI; | ||||||
463 | } while (IsNoopInstruction(&*BBI)); | ||||||
464 | |||||||
465 | if (GetRCIdentityRoot(&*BBI) == GetArgRCIdentityRoot(Inst)) { | ||||||
466 | LLVM_DEBUG(dbgs() << "Adding inline asm marker for the return value "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Adding inline asm marker for the return value " "optimization.\n"; } } while (false) | ||||||
467 | "optimization.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Adding inline asm marker for the return value " "optimization.\n"; } } while (false); | ||||||
468 | Changed = true; | ||||||
469 | InlineAsm *IA = | ||||||
470 | InlineAsm::get(FunctionType::get(Type::getVoidTy(Inst->getContext()), | ||||||
471 | /*isVarArg=*/false), | ||||||
472 | RVInstMarker->getString(), | ||||||
473 | /*Constraints=*/"", /*hasSideEffects=*/true); | ||||||
474 | |||||||
475 | objcarc::createCallInstWithColors(IA, None, "", Inst, BlockColors); | ||||||
476 | } | ||||||
477 | decline_rv_optimization: | ||||||
478 | return false; | ||||||
479 | } | ||||||
480 | case ARCInstKind::InitWeak: { | ||||||
481 | // objc_initWeak(p, null) => *p = null | ||||||
482 | CallInst *CI = cast<CallInst>(Inst); | ||||||
483 | if (IsNullOrUndef(CI->getArgOperand(1))) { | ||||||
484 | Value *Null = ConstantPointerNull::get(cast<PointerType>(CI->getType())); | ||||||
485 | Changed = true; | ||||||
486 | new StoreInst(Null, CI->getArgOperand(0), CI); | ||||||
487 | |||||||
488 | LLVM_DEBUG(dbgs() << "OBJCARCContract: Old = " << *CI << "\n"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "OBJCARCContract: Old = " << *CI << "\n" << " New = " << *Null << "\n"; } } while (false) | ||||||
489 | << " New = " << *Null << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "OBJCARCContract: Old = " << *CI << "\n" << " New = " << *Null << "\n"; } } while (false); | ||||||
490 | |||||||
491 | CI->replaceAllUsesWith(Null); | ||||||
492 | CI->eraseFromParent(); | ||||||
493 | } | ||||||
494 | return true; | ||||||
495 | } | ||||||
496 | case ARCInstKind::Release: | ||||||
497 | // Try to form an objc store strong from our release. If we fail, there is | ||||||
498 | // nothing further to do below, so continue. | ||||||
499 | tryToContractReleaseIntoStoreStrong(Inst, Iter, BlockColors); | ||||||
500 | return true; | ||||||
501 | case ARCInstKind::User: | ||||||
502 | // Be conservative if the function has any alloca instructions. | ||||||
503 | // Technically we only care about escaping alloca instructions, | ||||||
504 | // but this is sufficient to handle some interesting cases. | ||||||
505 | if (isa<AllocaInst>(Inst)) | ||||||
506 | TailOkForStoreStrongs = false; | ||||||
507 | return true; | ||||||
508 | case ARCInstKind::IntrinsicUser: | ||||||
509 | // Remove calls to @llvm.objc.clang.arc.use(...). | ||||||
510 | Changed = true; | ||||||
511 | Inst->eraseFromParent(); | ||||||
512 | return true; | ||||||
513 | default: | ||||||
514 | if (auto *CI = dyn_cast<CallInst>(Inst)) | ||||||
515 | if (CI->getIntrinsicID() == Intrinsic::objc_clang_arc_noop_use) { | ||||||
516 | // Remove calls to @llvm.objc.clang.arc.noop.use(...). | ||||||
517 | Changed = true; | ||||||
518 | CI->eraseFromParent(); | ||||||
519 | } | ||||||
520 | return true; | ||||||
521 | } | ||||||
522 | } | ||||||
523 | |||||||
524 | //===----------------------------------------------------------------------===// | ||||||
525 | // Top Level Driver | ||||||
526 | //===----------------------------------------------------------------------===// | ||||||
527 | |||||||
528 | bool ObjCARCContract::init(Module &M) { | ||||||
529 | EP.init(&M); | ||||||
530 | |||||||
531 | // Initialize RVInstMarker. | ||||||
532 | RVInstMarker = getRVInstMarker(M); | ||||||
533 | |||||||
534 | return false; | ||||||
535 | } | ||||||
536 | |||||||
537 | bool ObjCARCContract::run(Function &F, AAResults *A, DominatorTree *D) { | ||||||
538 | if (!EnableARCOpts) | ||||||
539 | return false; | ||||||
540 | |||||||
541 | Changed = CFGChanged = false; | ||||||
542 | AA = A; | ||||||
543 | DT = D; | ||||||
544 | PA.setAA(A); | ||||||
545 | BundledRetainClaimRVs BRV(/*ContractPass=*/true); | ||||||
546 | BundledInsts = &BRV; | ||||||
547 | |||||||
548 | std::pair<bool, bool> R = BundledInsts->insertAfterInvokes(F, DT); | ||||||
549 | Changed |= R.first; | ||||||
550 | CFGChanged |= R.second; | ||||||
551 | |||||||
552 | DenseMap<BasicBlock *, ColorVector> BlockColors; | ||||||
553 | if (F.hasPersonalityFn() && | ||||||
554 | isScopedEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) | ||||||
555 | BlockColors = colorEHFunclets(F); | ||||||
556 | |||||||
557 | LLVM_DEBUG(llvm::dbgs() << "**** ObjCARC Contract ****\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { llvm::dbgs() << "**** ObjCARC Contract ****\n" ; } } while (false); | ||||||
558 | |||||||
559 | // Track whether it's ok to mark objc_storeStrong calls with the "tail" | ||||||
560 | // keyword. Be conservative if the function has variadic arguments. | ||||||
561 | // It seems that functions which "return twice" are also unsafe for the | ||||||
562 | // "tail" argument, because they are setjmp, which could need to | ||||||
563 | // return to an earlier stack state. | ||||||
564 | bool TailOkForStoreStrongs = | ||||||
565 | !F.isVarArg() && !F.callsFunctionThatReturnsTwice(); | ||||||
566 | |||||||
567 | // For ObjC library calls which return their argument, replace uses of the | ||||||
568 | // argument with uses of the call return value, if it dominates the use. This | ||||||
569 | // reduces register pressure. | ||||||
570 | for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E;) { | ||||||
571 | Instruction *Inst = &*I++; | ||||||
572 | |||||||
573 | LLVM_DEBUG(dbgs() << "Visiting: " << *Inst << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("objc-arc-contract")) { dbgs() << "Visiting: " << *Inst << "\n"; } } while (false); | ||||||
574 | |||||||
575 | if (auto *CI
| ||||||
576 | if (objcarc::hasAttachedCallOpBundle(CI)) { | ||||||
577 | BundledInsts->insertRVCallWithColors(&*I, CI, BlockColors); | ||||||
578 | --I; | ||||||
579 | Changed = true; | ||||||
580 | } | ||||||
581 | |||||||
582 | // First try to peephole Inst. If there is nothing further we can do in | ||||||
583 | // terms of undoing objc-arc-expand, process the next inst. | ||||||
584 | if (tryToPeepholeInstruction(F, Inst, I, TailOkForStoreStrongs, | ||||||
585 | BlockColors)) | ||||||
586 | continue; | ||||||
587 | |||||||
588 | // Otherwise, try to undo objc-arc-expand. | ||||||
589 | |||||||
590 | // Don't use GetArgRCIdentityRoot because we don't want to look through bitcasts | ||||||
591 | // and such; to do the replacement, the argument must have type i8*. | ||||||
592 | |||||||
593 | // Function for replacing uses of Arg dominated by Inst. | ||||||
594 | auto ReplaceArgUses = [Inst, this](Value *Arg) { | ||||||
595 | // If we're compiling bugpointed code, don't get in trouble. | ||||||
596 | if (!isa<Instruction>(Arg) && !isa<Argument>(Arg)) | ||||||
597 | return; | ||||||
598 | |||||||
599 | // Look through the uses of the pointer. | ||||||
600 | for (Value::use_iterator UI = Arg->use_begin(), UE = Arg->use_end(); | ||||||
601 | UI != UE; ) { | ||||||
602 | // Increment UI now, because we may unlink its element. | ||||||
603 | Use &U = *UI++; | ||||||
604 | unsigned OperandNo = U.getOperandNo(); | ||||||
605 | |||||||
606 | // If the call's return value dominates a use of the call's argument | ||||||
607 | // value, rewrite the use to use the return value. We check for | ||||||
608 | // reachability here because an unreachable call is considered to | ||||||
609 | // trivially dominate itself, which would lead us to rewriting its | ||||||
610 | // argument in terms of its return value, which would lead to | ||||||
611 | // infinite loops in GetArgRCIdentityRoot. | ||||||
612 | if (!DT->isReachableFromEntry(U) || !DT->dominates(Inst, U)) | ||||||
613 | continue; | ||||||
614 | |||||||
615 | Changed = true; | ||||||
616 | Instruction *Replacement = Inst; | ||||||
617 | Type *UseTy = U.get()->getType(); | ||||||
618 | if (PHINode *PHI = dyn_cast<PHINode>(U.getUser())) { | ||||||
619 | // For PHI nodes, insert the bitcast in the predecessor block. | ||||||
620 | unsigned ValNo = PHINode::getIncomingValueNumForOperand(OperandNo); | ||||||
621 | BasicBlock *IncomingBB = PHI->getIncomingBlock(ValNo); | ||||||
622 | if (Replacement->getType() != UseTy) { | ||||||
623 | // A catchswitch is both a pad and a terminator, meaning a basic | ||||||
624 | // block with a catchswitch has no insertion point. Keep going up | ||||||
625 | // the dominator tree until we find a non-catchswitch. | ||||||
626 | BasicBlock *InsertBB = IncomingBB; | ||||||
627 | while (isa<CatchSwitchInst>(InsertBB->getFirstNonPHI())) { | ||||||
628 | InsertBB = DT->getNode(InsertBB)->getIDom()->getBlock(); | ||||||
629 | } | ||||||
630 | |||||||
631 | assert(DT->dominates(Inst, &InsertBB->back()) &&(static_cast <bool> (DT->dominates(Inst, &InsertBB ->back()) && "Invalid insertion point for bitcast" ) ? void (0) : __assert_fail ("DT->dominates(Inst, &InsertBB->back()) && \"Invalid insertion point for bitcast\"" , "llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp", 632, __extension__ __PRETTY_FUNCTION__)) | ||||||
632 | "Invalid insertion point for bitcast")(static_cast <bool> (DT->dominates(Inst, &InsertBB ->back()) && "Invalid insertion point for bitcast" ) ? void (0) : __assert_fail ("DT->dominates(Inst, &InsertBB->back()) && \"Invalid insertion point for bitcast\"" , "llvm/lib/Transforms/ObjCARC/ObjCARCContract.cpp", 632, __extension__ __PRETTY_FUNCTION__)); | ||||||
633 | Replacement = | ||||||
634 | new BitCastInst(Replacement, UseTy, "", &InsertBB->back()); | ||||||
635 | } | ||||||
636 | |||||||
637 | // While we're here, rewrite all edges for this PHI, rather | ||||||
638 | // than just one use at a time, to minimize the number of | ||||||
639 | // bitcasts we emit. | ||||||
640 | for (unsigned i = 0, e = PHI->getNumIncomingValues(); i != e; ++i) | ||||||
641 | if (PHI->getIncomingBlock(i) == IncomingBB) { | ||||||
642 | // Keep the UI iterator valid. | ||||||
643 | if (UI != UE && | ||||||
644 | &PHI->getOperandUse( | ||||||
645 | PHINode::getOperandNumForIncomingValue(i)) == &*UI) | ||||||
646 | ++UI; | ||||||
647 | PHI->setIncomingValue(i, Replacement); | ||||||
648 | } | ||||||
649 | } else { | ||||||
650 | if (Replacement->getType() != UseTy) | ||||||
651 | Replacement = new BitCastInst(Replacement, UseTy, "", | ||||||
652 | cast<Instruction>(U.getUser())); | ||||||
653 | U.set(Replacement); | ||||||
654 | } | ||||||
655 | } | ||||||
656 | }; | ||||||
657 | |||||||
658 | Value *Arg = cast<CallInst>(Inst)->getArgOperand(0); | ||||||
659 | Value *OrigArg = Arg; | ||||||
660 | |||||||
661 | // TODO: Change this to a do-while. | ||||||
662 | for (;;) { | ||||||
663 | ReplaceArgUses(Arg); | ||||||
664 | |||||||
665 | // If Arg is a no-op casted pointer, strip one level of casts and iterate. | ||||||
666 | if (const BitCastInst *BI = dyn_cast<BitCastInst>(Arg)) | ||||||
667 | Arg = BI->getOperand(0); | ||||||
668 | else if (isa<GEPOperator>(Arg) && | ||||||
669 | cast<GEPOperator>(Arg)->hasAllZeroIndices()) | ||||||
670 | Arg = cast<GEPOperator>(Arg)->getPointerOperand(); | ||||||
671 | else if (isa<GlobalAlias>(Arg) && | ||||||
672 | !cast<GlobalAlias>(Arg)->isInterposable()) | ||||||
673 | Arg = cast<GlobalAlias>(Arg)->getAliasee(); | ||||||
674 | else { | ||||||
675 | // If Arg is a PHI node, get PHIs that are equivalent to it and replace | ||||||
676 | // their uses. | ||||||
677 | if (PHINode *PN = dyn_cast<PHINode>(Arg)) { | ||||||
678 | SmallVector<Value *, 1> PHIList; | ||||||
679 | getEquivalentPHIs(*PN, PHIList); | ||||||
680 | for (Value *PHI : PHIList) | ||||||
681 | ReplaceArgUses(PHI); | ||||||
682 | } | ||||||
683 | break; | ||||||
684 | } | ||||||
685 | } | ||||||
686 | |||||||
687 | // Replace bitcast users of Arg that are dominated by Inst. | ||||||
688 | SmallVector<BitCastInst *, 2> BitCastUsers; | ||||||
689 | |||||||
690 | // Add all bitcast users of the function argument first. | ||||||
691 | for (User *U : OrigArg->users()) | ||||||
692 | if (auto *BC = dyn_cast<BitCastInst>(U)) | ||||||
693 | BitCastUsers.push_back(BC); | ||||||
694 | |||||||
695 | // Replace the bitcasts with the call return. Iterate until list is empty. | ||||||
696 | while (!BitCastUsers.empty()) { | ||||||
697 | auto *BC = BitCastUsers.pop_back_val(); | ||||||
698 | for (User *U : BC->users()) | ||||||
699 | if (auto *B = dyn_cast<BitCastInst>(U)) | ||||||
700 | BitCastUsers.push_back(B); | ||||||
701 | |||||||
702 | ReplaceArgUses(BC); | ||||||
703 | } | ||||||
704 | } | ||||||
705 | |||||||
706 | // If this function has no escaping allocas or suspicious vararg usage, | ||||||
707 | // objc_storeStrong calls can be marked with the "tail" keyword. | ||||||
708 | if (TailOkForStoreStrongs) | ||||||
709 | for (CallInst *CI : StoreStrongCalls) | ||||||
710 | CI->setTailCall(); | ||||||
711 | StoreStrongCalls.clear(); | ||||||
712 | |||||||
713 | return Changed; | ||||||
714 | } | ||||||
715 | |||||||
716 | //===----------------------------------------------------------------------===// | ||||||
717 | // Misc Pass Manager | ||||||
718 | //===----------------------------------------------------------------------===// | ||||||
719 | |||||||
720 | char ObjCARCContractLegacyPass::ID = 0; | ||||||
721 | INITIALIZE_PASS_BEGIN(ObjCARCContractLegacyPass, "objc-arc-contract",static void *initializeObjCARCContractLegacyPassPassOnce(PassRegistry &Registry) { | ||||||
722 | "ObjC ARC contraction", false, false)static void *initializeObjCARCContractLegacyPassPassOnce(PassRegistry &Registry) { | ||||||
723 | INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)initializeAAResultsWrapperPassPass(Registry); | ||||||
724 | INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry); | ||||||
725 | INITIALIZE_PASS_END(ObjCARCContractLegacyPass, "objc-arc-contract",PassInfo *PI = new PassInfo( "ObjC ARC contraction", "objc-arc-contract" , &ObjCARCContractLegacyPass::ID, PassInfo::NormalCtor_t( callDefaultCtor<ObjCARCContractLegacyPass>), false, false ); Registry.registerPass(*PI, true); return PI; } static llvm ::once_flag InitializeObjCARCContractLegacyPassPassFlag; void llvm::initializeObjCARCContractLegacyPassPass(PassRegistry & Registry) { llvm::call_once(InitializeObjCARCContractLegacyPassPassFlag , initializeObjCARCContractLegacyPassPassOnce, std::ref(Registry )); } | ||||||
726 | "ObjC ARC contraction", false, false)PassInfo *PI = new PassInfo( "ObjC ARC contraction", "objc-arc-contract" , &ObjCARCContractLegacyPass::ID, PassInfo::NormalCtor_t( callDefaultCtor<ObjCARCContractLegacyPass>), false, false ); Registry.registerPass(*PI, true); return PI; } static llvm ::once_flag InitializeObjCARCContractLegacyPassPassFlag; void llvm::initializeObjCARCContractLegacyPassPass(PassRegistry & Registry) { llvm::call_once(InitializeObjCARCContractLegacyPassPassFlag , initializeObjCARCContractLegacyPassPassOnce, std::ref(Registry )); } | ||||||
727 | |||||||
728 | void ObjCARCContractLegacyPass::getAnalysisUsage(AnalysisUsage &AU) const { | ||||||
729 | AU.addRequired<AAResultsWrapperPass>(); | ||||||
730 | AU.addRequired<DominatorTreeWrapperPass>(); | ||||||
731 | } | ||||||
732 | |||||||
733 | Pass *llvm::createObjCARCContractPass() { | ||||||
734 | return new ObjCARCContractLegacyPass(); | ||||||
735 | } | ||||||
736 | |||||||
737 | bool ObjCARCContractLegacyPass::runOnFunction(Function &F) { | ||||||
738 | ObjCARCContract OCARCC; | ||||||
739 | OCARCC.init(*F.getParent()); | ||||||
740 | auto *AA = &getAnalysis<AAResultsWrapperPass>().getAAResults(); | ||||||
741 | auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | ||||||
742 | return OCARCC.run(F, AA, DT); | ||||||
743 | } | ||||||
744 | |||||||
745 | PreservedAnalyses ObjCARCContractPass::run(Function &F, | ||||||
746 | FunctionAnalysisManager &AM) { | ||||||
747 | ObjCARCContract OCAC; | ||||||
748 | OCAC.init(*F.getParent()); | ||||||
749 | |||||||
750 | bool Changed = OCAC.run(F, &AM.getResult<AAManager>(F), | ||||||
| |||||||
751 | &AM.getResult<DominatorTreeAnalysis>(F)); | ||||||
752 | bool CFGChanged = OCAC.hasCFGChanged(); | ||||||
753 | if (Changed) { | ||||||
754 | PreservedAnalyses PA; | ||||||
755 | if (!CFGChanged) | ||||||
756 | PA.preserveSet<CFGAnalyses>(); | ||||||
757 | return PA; | ||||||
758 | } | ||||||
759 | return PreservedAnalyses::all(); | ||||||
760 | } |