LLVM 17.0.0git
ObjCARCInstKind.cpp
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1//===- ARCInstKind.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 several utility functions used by various ARC
10/// optimizations which are IMHO too big to be in a header file.
11///
12/// WARNING: This file knows about certain library functions. It recognizes them
13/// by name, and hardwires knowledge of their semantics.
14///
15/// WARNING: This file knows about how certain Objective-C library functions are
16/// used. Naive LLVM IR transformations which would otherwise be
17/// behavior-preserving may break these assumptions.
18///
19//===----------------------------------------------------------------------===//
20
21#include "llvm/Analysis/ObjCARCInstKind.h"
22#include "llvm/Analysis/ObjCARCAnalysisUtils.h"
23#include "llvm/IR/Intrinsics.h"
24
25using namespace llvm;
26using namespace llvm::objcarc;
27
28raw_ostream &llvm::objcarc::operator<<(raw_ostream &OS,
29 const ARCInstKind Class) {
30 switch (Class) {
31 case ARCInstKind::Retain:
32 return OS << "ARCInstKind::Retain";
33 case ARCInstKind::RetainRV:
34 return OS << "ARCInstKind::RetainRV";
35 case ARCInstKind::UnsafeClaimRV:
36 return OS << "ARCInstKind::UnsafeClaimRV";
37 case ARCInstKind::RetainBlock:
38 return OS << "ARCInstKind::RetainBlock";
39 case ARCInstKind::Release:
40 return OS << "ARCInstKind::Release";
41 case ARCInstKind::Autorelease:
42 return OS << "ARCInstKind::Autorelease";
43 case ARCInstKind::AutoreleaseRV:
44 return OS << "ARCInstKind::AutoreleaseRV";
45 case ARCInstKind::AutoreleasepoolPush:
46 return OS << "ARCInstKind::AutoreleasepoolPush";
47 case ARCInstKind::AutoreleasepoolPop:
48 return OS << "ARCInstKind::AutoreleasepoolPop";
49 case ARCInstKind::NoopCast:
50 return OS << "ARCInstKind::NoopCast";
51 case ARCInstKind::FusedRetainAutorelease:
52 return OS << "ARCInstKind::FusedRetainAutorelease";
53 case ARCInstKind::FusedRetainAutoreleaseRV:
54 return OS << "ARCInstKind::FusedRetainAutoreleaseRV";
55 case ARCInstKind::LoadWeakRetained:
56 return OS << "ARCInstKind::LoadWeakRetained";
57 case ARCInstKind::StoreWeak:
58 return OS << "ARCInstKind::StoreWeak";
59 case ARCInstKind::InitWeak:
60 return OS << "ARCInstKind::InitWeak";
61 case ARCInstKind::LoadWeak:
62 return OS << "ARCInstKind::LoadWeak";
63 case ARCInstKind::MoveWeak:
64 return OS << "ARCInstKind::MoveWeak";
65 case ARCInstKind::CopyWeak:
66 return OS << "ARCInstKind::CopyWeak";
67 case ARCInstKind::DestroyWeak:
68 return OS << "ARCInstKind::DestroyWeak";
69 case ARCInstKind::StoreStrong:
70 return OS << "ARCInstKind::StoreStrong";
71 case ARCInstKind::CallOrUser:
72 return OS << "ARCInstKind::CallOrUser";
73 case ARCInstKind::Call:
74 return OS << "ARCInstKind::Call";
75 case ARCInstKind::User:
76 return OS << "ARCInstKind::User";
77 case ARCInstKind::IntrinsicUser:
78 return OS << "ARCInstKind::IntrinsicUser";
79 case ARCInstKind::None:
80 return OS << "ARCInstKind::None";
81 }
82 llvm_unreachable("Unknown instruction class!");
83}
84
85ARCInstKind llvm::objcarc::GetFunctionClass(const Function *F) {
86
87 Intrinsic::ID ID = F->getIntrinsicID();
88 switch (ID) {
89 default:
90 return ARCInstKind::CallOrUser;
91 case Intrinsic::objc_autorelease:
92 return ARCInstKind::Autorelease;
93 case Intrinsic::objc_autoreleasePoolPop:
94 return ARCInstKind::AutoreleasepoolPop;
95 case Intrinsic::objc_autoreleasePoolPush:
96 return ARCInstKind::AutoreleasepoolPush;
97 case Intrinsic::objc_autoreleaseReturnValue:
98 return ARCInstKind::AutoreleaseRV;
99 case Intrinsic::objc_copyWeak:
100 return ARCInstKind::CopyWeak;
101 case Intrinsic::objc_destroyWeak:
102 return ARCInstKind::DestroyWeak;
103 case Intrinsic::objc_initWeak:
104 return ARCInstKind::InitWeak;
105 case Intrinsic::objc_loadWeak:
106 return ARCInstKind::LoadWeak;
107 case Intrinsic::objc_loadWeakRetained:
108 return ARCInstKind::LoadWeakRetained;
109 case Intrinsic::objc_moveWeak:
110 return ARCInstKind::MoveWeak;
111 case Intrinsic::objc_release:
112 return ARCInstKind::Release;
113 case Intrinsic::objc_retain:
114 return ARCInstKind::Retain;
115 case Intrinsic::objc_retainAutorelease:
116 return ARCInstKind::FusedRetainAutorelease;
117 case Intrinsic::objc_retainAutoreleaseReturnValue:
118 return ARCInstKind::FusedRetainAutoreleaseRV;
119 case Intrinsic::objc_retainAutoreleasedReturnValue:
120 return ARCInstKind::RetainRV;
121 case Intrinsic::objc_retainBlock:
122 return ARCInstKind::RetainBlock;
123 case Intrinsic::objc_storeStrong:
124 return ARCInstKind::StoreStrong;
125 case Intrinsic::objc_storeWeak:
126 return ARCInstKind::StoreWeak;
127 case Intrinsic::objc_clang_arc_use:
128 return ARCInstKind::IntrinsicUser;
129 case Intrinsic::objc_unsafeClaimAutoreleasedReturnValue:
130 return ARCInstKind::UnsafeClaimRV;
131 case Intrinsic::objc_retainedObject:
132 return ARCInstKind::NoopCast;
133 case Intrinsic::objc_unretainedObject:
134 return ARCInstKind::NoopCast;
135 case Intrinsic::objc_unretainedPointer:
136 return ARCInstKind::NoopCast;
137 case Intrinsic::objc_retain_autorelease:
138 return ARCInstKind::FusedRetainAutorelease;
139 case Intrinsic::objc_sync_enter:
140 return ARCInstKind::User;
141 case Intrinsic::objc_sync_exit:
142 return ARCInstKind::User;
143 case Intrinsic::objc_clang_arc_noop_use:
144 case Intrinsic::objc_arc_annotation_topdown_bbstart:
145 case Intrinsic::objc_arc_annotation_topdown_bbend:
146 case Intrinsic::objc_arc_annotation_bottomup_bbstart:
147 case Intrinsic::objc_arc_annotation_bottomup_bbend:
148 // Ignore annotation calls. This is important to stop the
149 // optimizer from treating annotations as uses which would
150 // make the state of the pointers they are attempting to
151 // elucidate to be incorrect.
152 return ARCInstKind::None;
153 }
154}
155
156// A list of intrinsics that we know do not use objc pointers or decrement
157// ref counts.
158static bool isInertIntrinsic(unsigned ID) {
159 // TODO: Make this into a covered switch.
160 switch (ID) {
161 case Intrinsic::returnaddress:
162 case Intrinsic::addressofreturnaddress:
163 case Intrinsic::frameaddress:
164 case Intrinsic::stacksave:
165 case Intrinsic::stackrestore:
166 case Intrinsic::vastart:
167 case Intrinsic::vacopy:
168 case Intrinsic::vaend:
169 case Intrinsic::objectsize:
170 case Intrinsic::prefetch:
171 case Intrinsic::stackprotector:
172 case Intrinsic::eh_return_i32:
173 case Intrinsic::eh_return_i64:
174 case Intrinsic::eh_typeid_for:
175 case Intrinsic::eh_dwarf_cfa:
176 case Intrinsic::eh_sjlj_lsda:
177 case Intrinsic::eh_sjlj_functioncontext:
178 case Intrinsic::init_trampoline:
179 case Intrinsic::adjust_trampoline:
180 case Intrinsic::lifetime_start:
181 case Intrinsic::lifetime_end:
182 case Intrinsic::invariant_start:
183 case Intrinsic::invariant_end:
184 // Don't let dbg info affect our results.
185 case Intrinsic::dbg_declare:
186 case Intrinsic::dbg_value:
187 case Intrinsic::dbg_label:
188 // Short cut: Some intrinsics obviously don't use ObjC pointers.
189 return true;
190 default:
191 return false;
192 }
193}
194
195// A list of intrinsics that we know do not use objc pointers or decrement
196// ref counts.
197static bool isUseOnlyIntrinsic(unsigned ID) {
198 // We are conservative and even though intrinsics are unlikely to touch
199 // reference counts, we white list them for safety.
200 //
201 // TODO: Expand this into a covered switch. There is a lot more here.
202 switch (ID) {
203 case Intrinsic::memcpy:
204 case Intrinsic::memmove:
205 case Intrinsic::memset:
206 return true;
207 default:
208 return false;
209 }
210}
211
212/// Determine what kind of construct V is.
213ARCInstKind llvm::objcarc::GetARCInstKind(const Value *V) {
214 if (const Instruction *I = dyn_cast<Instruction>(V)) {
215 // Any instruction other than bitcast and gep with a pointer operand have a
216 // use of an objc pointer. Bitcasts, GEPs, Selects, PHIs transfer a pointer
217 // to a subsequent use, rather than using it themselves, in this sense.
218 // As a short cut, several other opcodes are known to have no pointer
219 // operands of interest. And ret is never followed by a release, so it's
220 // not interesting to examine.
221 switch (I->getOpcode()) {
222 case Instruction::Call: {
223 const CallInst *CI = cast<CallInst>(I);
224 // See if we have a function that we know something about.
225 if (const Function *F = CI->getCalledFunction()) {
226 ARCInstKind Class = GetFunctionClass(F);
227 if (Class != ARCInstKind::CallOrUser)
228 return Class;
229 Intrinsic::ID ID = F->getIntrinsicID();
230 if (isInertIntrinsic(ID))
231 return ARCInstKind::None;
232 if (isUseOnlyIntrinsic(ID))
233 return ARCInstKind::User;
234 }
235
236 // Otherwise, be conservative.
237 return GetCallSiteClass(*CI);
238 }
239 case Instruction::Invoke:
240 // Otherwise, be conservative.
241 return GetCallSiteClass(cast<InvokeInst>(*I));
242 case Instruction::BitCast:
243 case Instruction::GetElementPtr:
244 case Instruction::Select:
245 case Instruction::PHI:
246 case Instruction::Ret:
247 case Instruction::Br:
248 case Instruction::Switch:
249 case Instruction::IndirectBr:
250 case Instruction::Alloca:
251 case Instruction::VAArg:
252 case Instruction::Add:
253 case Instruction::FAdd:
254 case Instruction::Sub:
255 case Instruction::FSub:
256 case Instruction::Mul:
257 case Instruction::FMul:
258 case Instruction::SDiv:
259 case Instruction::UDiv:
260 case Instruction::FDiv:
261 case Instruction::SRem:
262 case Instruction::URem:
263 case Instruction::FRem:
264 case Instruction::Shl:
265 case Instruction::LShr:
266 case Instruction::AShr:
267 case Instruction::And:
268 case Instruction::Or:
269 case Instruction::Xor:
270 case Instruction::SExt:
271 case Instruction::ZExt:
272 case Instruction::Trunc:
273 case Instruction::IntToPtr:
274 case Instruction::FCmp:
275 case Instruction::FPTrunc:
276 case Instruction::FPExt:
277 case Instruction::FPToUI:
278 case Instruction::FPToSI:
279 case Instruction::UIToFP:
280 case Instruction::SIToFP:
281 case Instruction::InsertElement:
282 case Instruction::ExtractElement:
283 case Instruction::ShuffleVector:
284 case Instruction::ExtractValue:
285 break;
286 case Instruction::ICmp:
287 // Comparing a pointer with null, or any other constant, isn't an
288 // interesting use, because we don't care what the pointer points to, or
289 // about the values of any other dynamic reference-counted pointers.
290 if (IsPotentialRetainableObjPtr(I->getOperand(1)))
291 return ARCInstKind::User;
292 break;
293 default:
294 // For anything else, check all the operands.
295 // Note that this includes both operands of a Store: while the first
296 // operand isn't actually being dereferenced, it is being stored to
297 // memory where we can no longer track who might read it and dereference
298 // it, so we have to consider it potentially used.
299 for (const Use &U : I->operands())
300 if (IsPotentialRetainableObjPtr(U))
301 return ARCInstKind::User;
302 }
303 }
304
305 // Otherwise, it's totally inert for ARC purposes.
306 return ARCInstKind::None;
307}
308
309/// Test if the given class is a kind of user.
310bool llvm::objcarc::IsUser(ARCInstKind Class) {
311 switch (Class) {
312 case ARCInstKind::User:
313 case ARCInstKind::CallOrUser:
314 case ARCInstKind::IntrinsicUser:
315 return true;
316 case ARCInstKind::Retain:
317 case ARCInstKind::RetainRV:
318 case ARCInstKind::RetainBlock:
319 case ARCInstKind::Release:
320 case ARCInstKind::Autorelease:
321 case ARCInstKind::AutoreleaseRV:
322 case ARCInstKind::AutoreleasepoolPush:
323 case ARCInstKind::AutoreleasepoolPop:
324 case ARCInstKind::NoopCast:
325 case ARCInstKind::FusedRetainAutorelease:
326 case ARCInstKind::FusedRetainAutoreleaseRV:
327 case ARCInstKind::LoadWeakRetained:
328 case ARCInstKind::StoreWeak:
329 case ARCInstKind::InitWeak:
330 case ARCInstKind::LoadWeak:
331 case ARCInstKind::MoveWeak:
332 case ARCInstKind::CopyWeak:
333 case ARCInstKind::DestroyWeak:
334 case ARCInstKind::StoreStrong:
335 case ARCInstKind::Call:
336 case ARCInstKind::None:
337 case ARCInstKind::UnsafeClaimRV:
338 return false;
339 }
340 llvm_unreachable("covered switch isn't covered?");
341}
342
343/// Test if the given class is objc_retain or equivalent.
344bool llvm::objcarc::IsRetain(ARCInstKind Class) {
345 switch (Class) {
346 case ARCInstKind::Retain:
347 case ARCInstKind::RetainRV:
348 return true;
349 // I believe we treat retain block as not a retain since it can copy its
350 // block.
351 case ARCInstKind::RetainBlock:
352 case ARCInstKind::Release:
353 case ARCInstKind::Autorelease:
354 case ARCInstKind::AutoreleaseRV:
355 case ARCInstKind::AutoreleasepoolPush:
356 case ARCInstKind::AutoreleasepoolPop:
357 case ARCInstKind::NoopCast:
358 case ARCInstKind::FusedRetainAutorelease:
359 case ARCInstKind::FusedRetainAutoreleaseRV:
360 case ARCInstKind::LoadWeakRetained:
361 case ARCInstKind::StoreWeak:
362 case ARCInstKind::InitWeak:
363 case ARCInstKind::LoadWeak:
364 case ARCInstKind::MoveWeak:
365 case ARCInstKind::CopyWeak:
366 case ARCInstKind::DestroyWeak:
367 case ARCInstKind::StoreStrong:
368 case ARCInstKind::IntrinsicUser:
369 case ARCInstKind::CallOrUser:
370 case ARCInstKind::Call:
371 case ARCInstKind::User:
372 case ARCInstKind::None:
373 case ARCInstKind::UnsafeClaimRV:
374 return false;
375 }
376 llvm_unreachable("covered switch isn't covered?");
377}
378
379/// Test if the given class is objc_autorelease or equivalent.
380bool llvm::objcarc::IsAutorelease(ARCInstKind Class) {
381 switch (Class) {
382 case ARCInstKind::Autorelease:
383 case ARCInstKind::AutoreleaseRV:
384 return true;
385 case ARCInstKind::Retain:
386 case ARCInstKind::RetainRV:
387 case ARCInstKind::UnsafeClaimRV:
388 case ARCInstKind::RetainBlock:
389 case ARCInstKind::Release:
390 case ARCInstKind::AutoreleasepoolPush:
391 case ARCInstKind::AutoreleasepoolPop:
392 case ARCInstKind::NoopCast:
393 case ARCInstKind::FusedRetainAutorelease:
394 case ARCInstKind::FusedRetainAutoreleaseRV:
395 case ARCInstKind::LoadWeakRetained:
396 case ARCInstKind::StoreWeak:
397 case ARCInstKind::InitWeak:
398 case ARCInstKind::LoadWeak:
399 case ARCInstKind::MoveWeak:
400 case ARCInstKind::CopyWeak:
401 case ARCInstKind::DestroyWeak:
402 case ARCInstKind::StoreStrong:
403 case ARCInstKind::IntrinsicUser:
404 case ARCInstKind::CallOrUser:
405 case ARCInstKind::Call:
406 case ARCInstKind::User:
407 case ARCInstKind::None:
408 return false;
409 }
410 llvm_unreachable("covered switch isn't covered?");
411}
412
413/// Test if the given class represents instructions which return their
414/// argument verbatim.
415bool llvm::objcarc::IsForwarding(ARCInstKind Class) {
416 switch (Class) {
417 case ARCInstKind::Retain:
418 case ARCInstKind::RetainRV:
419 case ARCInstKind::UnsafeClaimRV:
420 case ARCInstKind::Autorelease:
421 case ARCInstKind::AutoreleaseRV:
422 case ARCInstKind::NoopCast:
423 return true;
424 case ARCInstKind::RetainBlock:
425 case ARCInstKind::Release:
426 case ARCInstKind::AutoreleasepoolPush:
427 case ARCInstKind::AutoreleasepoolPop:
428 case ARCInstKind::FusedRetainAutorelease:
429 case ARCInstKind::FusedRetainAutoreleaseRV:
430 case ARCInstKind::LoadWeakRetained:
431 case ARCInstKind::StoreWeak:
432 case ARCInstKind::InitWeak:
433 case ARCInstKind::LoadWeak:
434 case ARCInstKind::MoveWeak:
435 case ARCInstKind::CopyWeak:
436 case ARCInstKind::DestroyWeak:
437 case ARCInstKind::StoreStrong:
438 case ARCInstKind::IntrinsicUser:
439 case ARCInstKind::CallOrUser:
440 case ARCInstKind::Call:
441 case ARCInstKind::User:
442 case ARCInstKind::None:
443 return false;
444 }
445 llvm_unreachable("covered switch isn't covered?");
446}
447
448/// Test if the given class represents instructions which do nothing if
449/// passed a null pointer.
450bool llvm::objcarc::IsNoopOnNull(ARCInstKind Class) {
451 switch (Class) {
452 case ARCInstKind::Retain:
453 case ARCInstKind::RetainRV:
454 case ARCInstKind::UnsafeClaimRV:
455 case ARCInstKind::Release:
456 case ARCInstKind::Autorelease:
457 case ARCInstKind::AutoreleaseRV:
458 case ARCInstKind::RetainBlock:
459 return true;
460 case ARCInstKind::AutoreleasepoolPush:
461 case ARCInstKind::AutoreleasepoolPop:
462 case ARCInstKind::FusedRetainAutorelease:
463 case ARCInstKind::FusedRetainAutoreleaseRV:
464 case ARCInstKind::LoadWeakRetained:
465 case ARCInstKind::StoreWeak:
466 case ARCInstKind::InitWeak:
467 case ARCInstKind::LoadWeak:
468 case ARCInstKind::MoveWeak:
469 case ARCInstKind::CopyWeak:
470 case ARCInstKind::DestroyWeak:
471 case ARCInstKind::StoreStrong:
472 case ARCInstKind::IntrinsicUser:
473 case ARCInstKind::CallOrUser:
474 case ARCInstKind::Call:
475 case ARCInstKind::User:
476 case ARCInstKind::None:
477 case ARCInstKind::NoopCast:
478 return false;
479 }
480 llvm_unreachable("covered switch isn't covered?");
481}
482
483/// Test if the given class represents instructions which do nothing if
484/// passed a global variable.
485bool llvm::objcarc::IsNoopOnGlobal(ARCInstKind Class) {
486 switch (Class) {
487 case ARCInstKind::Retain:
488 case ARCInstKind::RetainRV:
489 case ARCInstKind::UnsafeClaimRV:
490 case ARCInstKind::Release:
491 case ARCInstKind::Autorelease:
492 case ARCInstKind::AutoreleaseRV:
493 case ARCInstKind::RetainBlock:
494 case ARCInstKind::FusedRetainAutorelease:
495 case ARCInstKind::FusedRetainAutoreleaseRV:
496 return true;
497 case ARCInstKind::AutoreleasepoolPush:
498 case ARCInstKind::AutoreleasepoolPop:
499 case ARCInstKind::LoadWeakRetained:
500 case ARCInstKind::StoreWeak:
501 case ARCInstKind::InitWeak:
502 case ARCInstKind::LoadWeak:
503 case ARCInstKind::MoveWeak:
504 case ARCInstKind::CopyWeak:
505 case ARCInstKind::DestroyWeak:
506 case ARCInstKind::StoreStrong:
507 case ARCInstKind::IntrinsicUser:
508 case ARCInstKind::CallOrUser:
509 case ARCInstKind::Call:
510 case ARCInstKind::User:
511 case ARCInstKind::None:
512 case ARCInstKind::NoopCast:
513 return false;
514 }
515 llvm_unreachable("covered switch isn't covered?");
516}
517
518/// Test if the given class represents instructions which are always safe
519/// to mark with the "tail" keyword.
520bool llvm::objcarc::IsAlwaysTail(ARCInstKind Class) {
521 // ARCInstKind::RetainBlock may be given a stack argument.
522 switch (Class) {
523 case ARCInstKind::Retain:
524 case ARCInstKind::RetainRV:
525 case ARCInstKind::UnsafeClaimRV:
526 case ARCInstKind::AutoreleaseRV:
527 return true;
528 case ARCInstKind::Release:
529 case ARCInstKind::Autorelease:
530 case ARCInstKind::RetainBlock:
531 case ARCInstKind::AutoreleasepoolPush:
532 case ARCInstKind::AutoreleasepoolPop:
533 case ARCInstKind::FusedRetainAutorelease:
534 case ARCInstKind::FusedRetainAutoreleaseRV:
535 case ARCInstKind::LoadWeakRetained:
536 case ARCInstKind::StoreWeak:
537 case ARCInstKind::InitWeak:
538 case ARCInstKind::LoadWeak:
539 case ARCInstKind::MoveWeak:
540 case ARCInstKind::CopyWeak:
541 case ARCInstKind::DestroyWeak:
542 case ARCInstKind::StoreStrong:
543 case ARCInstKind::IntrinsicUser:
544 case ARCInstKind::CallOrUser:
545 case ARCInstKind::Call:
546 case ARCInstKind::User:
547 case ARCInstKind::None:
548 case ARCInstKind::NoopCast:
549 return false;
550 }
551 llvm_unreachable("covered switch isn't covered?");
552}
553
554/// Test if the given class represents instructions which are never safe
555/// to mark with the "tail" keyword.
556bool llvm::objcarc::IsNeverTail(ARCInstKind Class) {
557 /// It is never safe to tail call objc_autorelease since by tail calling
558 /// objc_autorelease: fast autoreleasing causing our object to be potentially
559 /// reclaimed from the autorelease pool which violates the semantics of
560 /// __autoreleasing types in ARC.
561 switch (Class) {
562 case ARCInstKind::Autorelease:
563 return true;
564 case ARCInstKind::Retain:
565 case ARCInstKind::RetainRV:
566 case ARCInstKind::UnsafeClaimRV:
567 case ARCInstKind::AutoreleaseRV:
568 case ARCInstKind::Release:
569 case ARCInstKind::RetainBlock:
570 case ARCInstKind::AutoreleasepoolPush:
571 case ARCInstKind::AutoreleasepoolPop:
572 case ARCInstKind::FusedRetainAutorelease:
573 case ARCInstKind::FusedRetainAutoreleaseRV:
574 case ARCInstKind::LoadWeakRetained:
575 case ARCInstKind::StoreWeak:
576 case ARCInstKind::InitWeak:
577 case ARCInstKind::LoadWeak:
578 case ARCInstKind::MoveWeak:
579 case ARCInstKind::CopyWeak:
580 case ARCInstKind::DestroyWeak:
581 case ARCInstKind::StoreStrong:
582 case ARCInstKind::IntrinsicUser:
583 case ARCInstKind::CallOrUser:
584 case ARCInstKind::Call:
585 case ARCInstKind::User:
586 case ARCInstKind::None:
587 case ARCInstKind::NoopCast:
588 return false;
589 }
590 llvm_unreachable("covered switch isn't covered?");
591}
592
593/// Test if the given class represents instructions which are always safe
594/// to mark with the nounwind attribute.
595bool llvm::objcarc::IsNoThrow(ARCInstKind Class) {
596 // objc_retainBlock is not nounwind because it calls user copy constructors
597 // which could theoretically throw.
598 switch (Class) {
599 case ARCInstKind::Retain:
600 case ARCInstKind::RetainRV:
601 case ARCInstKind::UnsafeClaimRV:
602 case ARCInstKind::Release:
603 case ARCInstKind::Autorelease:
604 case ARCInstKind::AutoreleaseRV:
605 case ARCInstKind::AutoreleasepoolPush:
606 case ARCInstKind::AutoreleasepoolPop:
607 return true;
608 case ARCInstKind::RetainBlock:
609 case ARCInstKind::FusedRetainAutorelease:
610 case ARCInstKind::FusedRetainAutoreleaseRV:
611 case ARCInstKind::LoadWeakRetained:
612 case ARCInstKind::StoreWeak:
613 case ARCInstKind::InitWeak:
614 case ARCInstKind::LoadWeak:
615 case ARCInstKind::MoveWeak:
616 case ARCInstKind::CopyWeak:
617 case ARCInstKind::DestroyWeak:
618 case ARCInstKind::StoreStrong:
619 case ARCInstKind::IntrinsicUser:
620 case ARCInstKind::CallOrUser:
621 case ARCInstKind::Call:
622 case ARCInstKind::User:
623 case ARCInstKind::None:
624 case ARCInstKind::NoopCast:
625 return false;
626 }
627 llvm_unreachable("covered switch isn't covered?");
628}
629
630/// Test whether the given instruction can autorelease any pointer or cause an
631/// autoreleasepool pop.
632///
633/// This means that it *could* interrupt the RV optimization.
634bool llvm::objcarc::CanInterruptRV(ARCInstKind Class) {
635 switch (Class) {
636 case ARCInstKind::AutoreleasepoolPop:
637 case ARCInstKind::CallOrUser:
638 case ARCInstKind::Call:
639 case ARCInstKind::Autorelease:
640 case ARCInstKind::AutoreleaseRV:
641 case ARCInstKind::FusedRetainAutorelease:
642 case ARCInstKind::FusedRetainAutoreleaseRV:
643 return true;
644 case ARCInstKind::Retain:
645 case ARCInstKind::RetainRV:
646 case ARCInstKind::UnsafeClaimRV:
647 case ARCInstKind::Release:
648 case ARCInstKind::AutoreleasepoolPush:
649 case ARCInstKind::RetainBlock:
650 case ARCInstKind::LoadWeakRetained:
651 case ARCInstKind::StoreWeak:
652 case ARCInstKind::InitWeak:
653 case ARCInstKind::LoadWeak:
654 case ARCInstKind::MoveWeak:
655 case ARCInstKind::CopyWeak:
656 case ARCInstKind::DestroyWeak:
657 case ARCInstKind::StoreStrong:
658 case ARCInstKind::IntrinsicUser:
659 case ARCInstKind::User:
660 case ARCInstKind::None:
661 case ARCInstKind::NoopCast:
662 return false;
663 }
664 llvm_unreachable("covered switch isn't covered?");
665}
666
667bool llvm::objcarc::CanDecrementRefCount(ARCInstKind Kind) {
668 switch (Kind) {
669 case ARCInstKind::Retain:
670 case ARCInstKind::RetainRV:
671 case ARCInstKind::Autorelease:
672 case ARCInstKind::AutoreleaseRV:
673 case ARCInstKind::NoopCast:
674 case ARCInstKind::FusedRetainAutorelease:
675 case ARCInstKind::FusedRetainAutoreleaseRV:
676 case ARCInstKind::IntrinsicUser:
677 case ARCInstKind::User:
678 case ARCInstKind::None:
679 return false;
680
681 // The cases below are conservative.
682
683 // RetainBlock can result in user defined copy constructors being called
684 // implying releases may occur.
685 case ARCInstKind::RetainBlock:
686 case ARCInstKind::Release:
687 case ARCInstKind::AutoreleasepoolPush:
688 case ARCInstKind::AutoreleasepoolPop:
689 case ARCInstKind::LoadWeakRetained:
690 case ARCInstKind::StoreWeak:
691 case ARCInstKind::InitWeak:
692 case ARCInstKind::LoadWeak:
693 case ARCInstKind::MoveWeak:
694 case ARCInstKind::CopyWeak:
695 case ARCInstKind::DestroyWeak:
696 case ARCInstKind::StoreStrong:
697 case ARCInstKind::CallOrUser:
698 case ARCInstKind::Call:
699 case ARCInstKind::UnsafeClaimRV:
700 return true;
701 }
702
703 llvm_unreachable("covered switch isn't covered?");
704}
F
#define F(x, y, z)
Definition: MD5.cpp:55
I
#define I(x, y, z)
Definition: MD5.cpp:58
ObjCARCAnalysisUtils.h
This file defines common analysis utilities used by the ObjC ARC Optimizer.
isInertIntrinsic
static bool isInertIntrinsic(unsigned ID)
Definition: ObjCARCInstKind.cpp:158
isUseOnlyIntrinsic
static bool isUseOnlyIntrinsic(unsigned ID)
Definition: ObjCARCInstKind.cpp:197
llvm::CallBase::getCalledFunction
Function * getCalledFunction() const
Returns the function called, or null if this is an indirect function invocation or the function signa...
Definition: InstrTypes.h:1406
llvm::CallInst
This class represents a function call, abstracting a target machine's calling convention.
Definition: Instructions.h:1485
llvm::Use
A Use represents the edge between a Value definition and its users.
Definition: Use.h:43
llvm::Value
LLVM Value Representation.
Definition: Value.h:74
llvm::raw_ostream
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
llvm_unreachable
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:143
llvm::objcarc::IsPotentialRetainableObjPtr
bool IsPotentialRetainableObjPtr(const Value *Op)
Test whether the given value is possible a retainable object pointer.
Definition: ObjCARCAnalysisUtils.h:146
llvm::objcarc::IsUser
bool IsUser(ARCInstKind Class)
Test if the given class is a kind of user.
Definition: ObjCARCInstKind.cpp:310
llvm::objcarc::operator<<
raw_ostream & operator<<(raw_ostream &OS, const ARCInstKind Class)
Definition: ObjCARCInstKind.cpp:28
llvm::objcarc::IsRetain
bool IsRetain(ARCInstKind Class)
Test if the given class is objc_retain or equivalent.
Definition: ObjCARCInstKind.cpp:344
llvm::objcarc::IsNeverTail
bool IsNeverTail(ARCInstKind Class)
Test if the given class represents instructions which are never safe to mark with the "tail" keyword.
Definition: ObjCARCInstKind.cpp:556
llvm::objcarc::IsAlwaysTail
bool IsAlwaysTail(ARCInstKind Class)
Test if the given class represents instructions which are always safe to mark with the "tail" keyword...
Definition: ObjCARCInstKind.cpp:520
llvm::objcarc::GetCallSiteClass
ARCInstKind GetCallSiteClass(const CallBase &CB)
Helper for GetARCInstKind.
Definition: ObjCARCAnalysisUtils.h:173
llvm::objcarc::IsAutorelease
bool IsAutorelease(ARCInstKind Class)
Test if the given class is objc_autorelease or equivalent.
Definition: ObjCARCInstKind.cpp:380
llvm::objcarc::ARCInstKind
ARCInstKind
Equivalence classes of instructions in the ARC Model.
Definition: ObjCARCInstKind.h:28
llvm::objcarc::GetFunctionClass
ARCInstKind GetFunctionClass(const Function *F)
Determine if F is one of the special known Functions.
Definition: ObjCARCInstKind.cpp:85
llvm::objcarc::IsForwarding
bool IsForwarding(ARCInstKind Class)
Test if the given class represents instructions which return their argument verbatim.
Definition: ObjCARCInstKind.cpp:415
llvm::objcarc::GetARCInstKind
ARCInstKind GetARCInstKind(const Value *V)
Map V to its ARCInstKind equivalence class.
Definition: ObjCARCInstKind.cpp:213
llvm::objcarc::CanInterruptRV
bool CanInterruptRV(ARCInstKind Class)
Test whether the given instruction can autorelease any pointer or cause an autoreleasepool pop.
Definition: ObjCARCInstKind.cpp:634
llvm::objcarc::IsNoThrow
bool IsNoThrow(ARCInstKind Class)
Test if the given class represents instructions which are always safe to mark with the nounwind attri...
Definition: ObjCARCInstKind.cpp:595
llvm::objcarc::CanDecrementRefCount
bool CanDecrementRefCount(ARCInstKind Kind)
Returns false if conservatively we can prove that any instruction mapped to this kind can not decreme...
Definition: ObjCARCInstKind.cpp:667
llvm::objcarc::IsNoopOnGlobal
bool IsNoopOnGlobal(ARCInstKind Class)
Test if the given class represents instructions which do nothing if passed a global variable.
Definition: ObjCARCInstKind.cpp:485
llvm::objcarc::IsNoopOnNull
bool IsNoopOnNull(ARCInstKind Class)
Test if the given class represents instructions which do nothing if passed a null pointer.
Definition: ObjCARCInstKind.cpp:450
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
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