1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "inliner.h"
18
19 #include "art_method-inl.h"
20 #include "base/enums.h"
21 #include "base/logging.h"
22 #include "builder.h"
23 #include "class_linker.h"
24 #include "class_root-inl.h"
25 #include "constant_folding.h"
26 #include "data_type-inl.h"
27 #include "dead_code_elimination.h"
28 #include "dex/inline_method_analyser.h"
29 #include "dex/verification_results.h"
30 #include "dex/verified_method.h"
31 #include "driver/compiler_options.h"
32 #include "driver/dex_compilation_unit.h"
33 #include "instruction_simplifier.h"
34 #include "intrinsics.h"
35 #include "jit/jit.h"
36 #include "jit/jit_code_cache.h"
37 #include "mirror/class_loader.h"
38 #include "mirror/dex_cache.h"
39 #include "mirror/object_array-alloc-inl.h"
40 #include "mirror/object_array-inl.h"
41 #include "nodes.h"
42 #include "reference_type_propagation.h"
43 #include "register_allocator_linear_scan.h"
44 #include "scoped_thread_state_change-inl.h"
45 #include "sharpening.h"
46 #include "ssa_builder.h"
47 #include "ssa_phi_elimination.h"
48 #include "thread.h"
49
50 namespace art {
51
52 // Instruction limit to control memory.
53 static constexpr size_t kMaximumNumberOfTotalInstructions = 1024;
54
55 // Maximum number of instructions for considering a method small,
56 // which we will always try to inline if the other non-instruction limits
57 // are not reached.
58 static constexpr size_t kMaximumNumberOfInstructionsForSmallMethod = 3;
59
60 // Limit the number of dex registers that we accumulate while inlining
61 // to avoid creating large amount of nested environments.
62 static constexpr size_t kMaximumNumberOfCumulatedDexRegisters = 32;
63
64 // Limit recursive call inlining, which do not benefit from too
65 // much inlining compared to code locality.
66 static constexpr size_t kMaximumNumberOfRecursiveCalls = 4;
67
68 // Controls the use of inline caches in AOT mode.
69 static constexpr bool kUseAOTInlineCaches = true;
70
71 // We check for line numbers to make sure the DepthString implementation
72 // aligns the output nicely.
73 #define LOG_INTERNAL(msg) \
74 static_assert(__LINE__ > 10, "Unhandled line number"); \
75 static_assert(__LINE__ < 10000, "Unhandled line number"); \
76 VLOG(compiler) << DepthString(__LINE__) << msg
77
78 #define LOG_TRY() LOG_INTERNAL("Try inlinining call: ")
79 #define LOG_NOTE() LOG_INTERNAL("Note: ")
80 #define LOG_SUCCESS() LOG_INTERNAL("Success: ")
81 #define LOG_FAIL(stats_ptr, stat) MaybeRecordStat(stats_ptr, stat); LOG_INTERNAL("Fail: ")
82 #define LOG_FAIL_NO_STAT() LOG_INTERNAL("Fail: ")
83
DepthString(int line) const84 std::string HInliner::DepthString(int line) const {
85 std::string value;
86 // Indent according to the inlining depth.
87 size_t count = depth_;
88 // Line numbers get printed in the log, so add a space if the log's line is less
89 // than 1000, and two if less than 100. 10 cannot be reached as it's the copyright.
90 if (!kIsTargetBuild) {
91 if (line < 100) {
92 value += " ";
93 }
94 if (line < 1000) {
95 value += " ";
96 }
97 // Safeguard if this file reaches more than 10000 lines.
98 DCHECK_LT(line, 10000);
99 }
100 for (size_t i = 0; i < count; ++i) {
101 value += " ";
102 }
103 return value;
104 }
105
CountNumberOfInstructions(HGraph * graph)106 static size_t CountNumberOfInstructions(HGraph* graph) {
107 size_t number_of_instructions = 0;
108 for (HBasicBlock* block : graph->GetReversePostOrderSkipEntryBlock()) {
109 for (HInstructionIterator instr_it(block->GetInstructions());
110 !instr_it.Done();
111 instr_it.Advance()) {
112 ++number_of_instructions;
113 }
114 }
115 return number_of_instructions;
116 }
117
UpdateInliningBudget()118 void HInliner::UpdateInliningBudget() {
119 if (total_number_of_instructions_ >= kMaximumNumberOfTotalInstructions) {
120 // Always try to inline small methods.
121 inlining_budget_ = kMaximumNumberOfInstructionsForSmallMethod;
122 } else {
123 inlining_budget_ = std::max(
124 kMaximumNumberOfInstructionsForSmallMethod,
125 kMaximumNumberOfTotalInstructions - total_number_of_instructions_);
126 }
127 }
128
Run()129 bool HInliner::Run() {
130 if (codegen_->GetCompilerOptions().GetInlineMaxCodeUnits() == 0) {
131 // Inlining effectively disabled.
132 return false;
133 } else if (graph_->IsDebuggable()) {
134 // For simplicity, we currently never inline when the graph is debuggable. This avoids
135 // doing some logic in the runtime to discover if a method could have been inlined.
136 return false;
137 }
138
139 bool didInline = false;
140
141 // Initialize the number of instructions for the method being compiled. Recursive calls
142 // to HInliner::Run have already updated the instruction count.
143 if (outermost_graph_ == graph_) {
144 total_number_of_instructions_ = CountNumberOfInstructions(graph_);
145 }
146
147 UpdateInliningBudget();
148 DCHECK_NE(total_number_of_instructions_, 0u);
149 DCHECK_NE(inlining_budget_, 0u);
150
151 // If we're compiling tests, honor inlining directives in method names:
152 // - if a method's name contains the substring "$noinline$", do not
153 // inline that method;
154 // - if a method's name contains the substring "$inline$", ensure
155 // that this method is actually inlined.
156 // We limit the latter to AOT compilation, as the JIT may or may not inline
157 // depending on the state of classes at runtime.
158 const bool honor_noinline_directives = codegen_->GetCompilerOptions().CompileArtTest();
159 const bool honor_inline_directives =
160 honor_noinline_directives && Runtime::Current()->IsAotCompiler();
161
162 // Keep a copy of all blocks when starting the visit.
163 ArenaVector<HBasicBlock*> blocks = graph_->GetReversePostOrder();
164 DCHECK(!blocks.empty());
165 // Because we are changing the graph when inlining,
166 // we just iterate over the blocks of the outer method.
167 // This avoids doing the inlining work again on the inlined blocks.
168 for (HBasicBlock* block : blocks) {
169 for (HInstruction* instruction = block->GetFirstInstruction(); instruction != nullptr;) {
170 HInstruction* next = instruction->GetNext();
171 HInvoke* call = instruction->AsInvoke();
172 // As long as the call is not intrinsified, it is worth trying to inline.
173 if (call != nullptr && call->GetIntrinsic() == Intrinsics::kNone) {
174 if (honor_noinline_directives) {
175 // Debugging case: directives in method names control or assert on inlining.
176 std::string callee_name = outer_compilation_unit_.GetDexFile()->PrettyMethod(
177 call->GetDexMethodIndex(), /* with_signature= */ false);
178 // Tests prevent inlining by having $noinline$ in their method names.
179 if (callee_name.find("$noinline$") == std::string::npos) {
180 if (TryInline(call)) {
181 didInline = true;
182 } else if (honor_inline_directives) {
183 bool should_have_inlined = (callee_name.find("$inline$") != std::string::npos);
184 CHECK(!should_have_inlined) << "Could not inline " << callee_name;
185 }
186 }
187 } else {
188 DCHECK(!honor_inline_directives);
189 // Normal case: try to inline.
190 if (TryInline(call)) {
191 didInline = true;
192 }
193 }
194 }
195 instruction = next;
196 }
197 }
198
199 return didInline;
200 }
201
IsMethodOrDeclaringClassFinal(ArtMethod * method)202 static bool IsMethodOrDeclaringClassFinal(ArtMethod* method)
203 REQUIRES_SHARED(Locks::mutator_lock_) {
204 return method->IsFinal() || method->GetDeclaringClass()->IsFinal();
205 }
206
207 /**
208 * Given the `resolved_method` looked up in the dex cache, try to find
209 * the actual runtime target of an interface or virtual call.
210 * Return nullptr if the runtime target cannot be proven.
211 */
FindVirtualOrInterfaceTarget(HInvoke * invoke,ArtMethod * resolved_method)212 static ArtMethod* FindVirtualOrInterfaceTarget(HInvoke* invoke, ArtMethod* resolved_method)
213 REQUIRES_SHARED(Locks::mutator_lock_) {
214 if (IsMethodOrDeclaringClassFinal(resolved_method)) {
215 // No need to lookup further, the resolved method will be the target.
216 return resolved_method;
217 }
218
219 HInstruction* receiver = invoke->InputAt(0);
220 if (receiver->IsNullCheck()) {
221 // Due to multiple levels of inlining within the same pass, it might be that
222 // null check does not have the reference type of the actual receiver.
223 receiver = receiver->InputAt(0);
224 }
225 ReferenceTypeInfo info = receiver->GetReferenceTypeInfo();
226 DCHECK(info.IsValid()) << "Invalid RTI for " << receiver->DebugName();
227 if (!info.IsExact()) {
228 // We currently only support inlining with known receivers.
229 // TODO: Remove this check, we should be able to inline final methods
230 // on unknown receivers.
231 return nullptr;
232 } else if (info.GetTypeHandle()->IsInterface()) {
233 // Statically knowing that the receiver has an interface type cannot
234 // help us find what is the target method.
235 return nullptr;
236 } else if (!resolved_method->GetDeclaringClass()->IsAssignableFrom(info.GetTypeHandle().Get())) {
237 // The method that we're trying to call is not in the receiver's class or super classes.
238 return nullptr;
239 } else if (info.GetTypeHandle()->IsErroneous()) {
240 // If the type is erroneous, do not go further, as we are going to query the vtable or
241 // imt table, that we can only safely do on non-erroneous classes.
242 return nullptr;
243 }
244
245 ClassLinker* cl = Runtime::Current()->GetClassLinker();
246 PointerSize pointer_size = cl->GetImagePointerSize();
247 if (invoke->IsInvokeInterface()) {
248 resolved_method = info.GetTypeHandle()->FindVirtualMethodForInterface(
249 resolved_method, pointer_size);
250 } else {
251 DCHECK(invoke->IsInvokeVirtual());
252 resolved_method = info.GetTypeHandle()->FindVirtualMethodForVirtual(
253 resolved_method, pointer_size);
254 }
255
256 if (resolved_method == nullptr) {
257 // The information we had on the receiver was not enough to find
258 // the target method. Since we check above the exact type of the receiver,
259 // the only reason this can happen is an IncompatibleClassChangeError.
260 return nullptr;
261 } else if (!resolved_method->IsInvokable()) {
262 // The information we had on the receiver was not enough to find
263 // the target method. Since we check above the exact type of the receiver,
264 // the only reason this can happen is an IncompatibleClassChangeError.
265 return nullptr;
266 } else if (IsMethodOrDeclaringClassFinal(resolved_method)) {
267 // A final method has to be the target method.
268 return resolved_method;
269 } else if (info.IsExact()) {
270 // If we found a method and the receiver's concrete type is statically
271 // known, we know for sure the target.
272 return resolved_method;
273 } else {
274 // Even if we did find a method, the receiver type was not enough to
275 // statically find the runtime target.
276 return nullptr;
277 }
278 }
279
FindMethodIndexIn(ArtMethod * method,const DexFile & dex_file,uint32_t name_and_signature_index)280 static uint32_t FindMethodIndexIn(ArtMethod* method,
281 const DexFile& dex_file,
282 uint32_t name_and_signature_index)
283 REQUIRES_SHARED(Locks::mutator_lock_) {
284 if (IsSameDexFile(*method->GetDexFile(), dex_file)) {
285 return method->GetDexMethodIndex();
286 } else {
287 return method->FindDexMethodIndexInOtherDexFile(dex_file, name_and_signature_index);
288 }
289 }
290
FindClassIndexIn(ObjPtr<mirror::Class> cls,const DexCompilationUnit & compilation_unit)291 static dex::TypeIndex FindClassIndexIn(ObjPtr<mirror::Class> cls,
292 const DexCompilationUnit& compilation_unit)
293 REQUIRES_SHARED(Locks::mutator_lock_) {
294 const DexFile& dex_file = *compilation_unit.GetDexFile();
295 dex::TypeIndex index;
296 if (cls->GetDexCache() == nullptr) {
297 DCHECK(cls->IsArrayClass()) << cls->PrettyClass();
298 index = cls->FindTypeIndexInOtherDexFile(dex_file);
299 } else if (!cls->GetDexTypeIndex().IsValid()) {
300 DCHECK(cls->IsProxyClass()) << cls->PrettyClass();
301 // TODO: deal with proxy classes.
302 } else if (IsSameDexFile(cls->GetDexFile(), dex_file)) {
303 DCHECK_EQ(cls->GetDexCache(), compilation_unit.GetDexCache().Get());
304 index = cls->GetDexTypeIndex();
305 } else {
306 index = cls->FindTypeIndexInOtherDexFile(dex_file);
307 // We cannot guarantee the entry will resolve to the same class,
308 // as there may be different class loaders. So only return the index if it's
309 // the right class already resolved with the class loader.
310 if (index.IsValid()) {
311 ObjPtr<mirror::Class> resolved = compilation_unit.GetClassLinker()->LookupResolvedType(
312 index, compilation_unit.GetDexCache().Get(), compilation_unit.GetClassLoader().Get());
313 if (resolved != cls) {
314 index = dex::TypeIndex::Invalid();
315 }
316 }
317 }
318
319 return index;
320 }
321
322 class ScopedProfilingInfoInlineUse {
323 public:
ScopedProfilingInfoInlineUse(ArtMethod * method,Thread * self)324 explicit ScopedProfilingInfoInlineUse(ArtMethod* method, Thread* self)
325 : method_(method),
326 self_(self),
327 // Fetch the profiling info ahead of using it. If it's null when fetching,
328 // we should not call JitCodeCache::DoneInlining.
329 profiling_info_(
330 Runtime::Current()->GetJit()->GetCodeCache()->NotifyCompilerUse(method, self)) {
331 }
332
~ScopedProfilingInfoInlineUse()333 ~ScopedProfilingInfoInlineUse() {
334 if (profiling_info_ != nullptr) {
335 PointerSize pointer_size = Runtime::Current()->GetClassLinker()->GetImagePointerSize();
336 DCHECK_EQ(profiling_info_, method_->GetProfilingInfo(pointer_size));
337 Runtime::Current()->GetJit()->GetCodeCache()->DoneCompilerUse(method_, self_);
338 }
339 }
340
GetProfilingInfo() const341 ProfilingInfo* GetProfilingInfo() const { return profiling_info_; }
342
343 private:
344 ArtMethod* const method_;
345 Thread* const self_;
346 ProfilingInfo* const profiling_info_;
347 };
348
GetInlineCacheType(const Handle<mirror::ObjectArray<mirror::Class>> & classes)349 HInliner::InlineCacheType HInliner::GetInlineCacheType(
350 const Handle<mirror::ObjectArray<mirror::Class>>& classes)
351 REQUIRES_SHARED(Locks::mutator_lock_) {
352 uint8_t number_of_types = 0;
353 for (; number_of_types < InlineCache::kIndividualCacheSize; ++number_of_types) {
354 if (classes->Get(number_of_types) == nullptr) {
355 break;
356 }
357 }
358
359 if (number_of_types == 0) {
360 return kInlineCacheUninitialized;
361 } else if (number_of_types == 1) {
362 return kInlineCacheMonomorphic;
363 } else if (number_of_types == InlineCache::kIndividualCacheSize) {
364 return kInlineCacheMegamorphic;
365 } else {
366 return kInlineCachePolymorphic;
367 }
368 }
369
GetMonomorphicType(Handle<mirror::ObjectArray<mirror::Class>> classes)370 static ObjPtr<mirror::Class> GetMonomorphicType(Handle<mirror::ObjectArray<mirror::Class>> classes)
371 REQUIRES_SHARED(Locks::mutator_lock_) {
372 DCHECK(classes->Get(0) != nullptr);
373 return classes->Get(0);
374 }
375
TryCHADevirtualization(ArtMethod * resolved_method)376 ArtMethod* HInliner::TryCHADevirtualization(ArtMethod* resolved_method) {
377 if (!resolved_method->HasSingleImplementation()) {
378 return nullptr;
379 }
380 if (Runtime::Current()->IsAotCompiler()) {
381 // No CHA-based devirtulization for AOT compiler (yet).
382 return nullptr;
383 }
384 if (Runtime::Current()->IsZygote()) {
385 // No CHA-based devirtulization for Zygote, as it compiles with
386 // offline information.
387 return nullptr;
388 }
389 if (outermost_graph_->IsCompilingOsr()) {
390 // We do not support HDeoptimize in OSR methods.
391 return nullptr;
392 }
393 PointerSize pointer_size = caller_compilation_unit_.GetClassLinker()->GetImagePointerSize();
394 ArtMethod* single_impl = resolved_method->GetSingleImplementation(pointer_size);
395 if (single_impl == nullptr) {
396 return nullptr;
397 }
398 if (single_impl->IsProxyMethod()) {
399 // Proxy method is a generic invoker that's not worth
400 // devirtualizing/inlining. It also causes issues when the proxy
401 // method is in another dex file if we try to rewrite invoke-interface to
402 // invoke-virtual because a proxy method doesn't have a real dex file.
403 return nullptr;
404 }
405 if (!single_impl->GetDeclaringClass()->IsResolved()) {
406 // There's a race with the class loading, which updates the CHA info
407 // before setting the class to resolved. So we just bail for this
408 // rare occurence.
409 return nullptr;
410 }
411 return single_impl;
412 }
413
IsMethodUnverified(const CompilerOptions & compiler_options,ArtMethod * method)414 static bool IsMethodUnverified(const CompilerOptions& compiler_options, ArtMethod* method)
415 REQUIRES_SHARED(Locks::mutator_lock_) {
416 if (!method->GetDeclaringClass()->IsVerified()) {
417 if (compiler_options.IsJitCompiler()) {
418 // We're at runtime, we know this is cold code if the class
419 // is not verified, so don't bother analyzing.
420 return true;
421 }
422 uint16_t class_def_idx = method->GetDeclaringClass()->GetDexClassDefIndex();
423 if (!compiler_options.IsMethodVerifiedWithoutFailures(method->GetDexMethodIndex(),
424 class_def_idx,
425 *method->GetDexFile())) {
426 // Method has soft or hard failures, don't analyze.
427 return true;
428 }
429 }
430 return false;
431 }
432
AlwaysThrows(const CompilerOptions & compiler_options,ArtMethod * method)433 static bool AlwaysThrows(const CompilerOptions& compiler_options, ArtMethod* method)
434 REQUIRES_SHARED(Locks::mutator_lock_) {
435 DCHECK(method != nullptr);
436 // Skip non-compilable and unverified methods.
437 if (!method->IsCompilable() || IsMethodUnverified(compiler_options, method)) {
438 return false;
439 }
440 // Skip native methods, methods with try blocks, and methods that are too large.
441 CodeItemDataAccessor accessor(method->DexInstructionData());
442 if (!accessor.HasCodeItem() ||
443 accessor.TriesSize() != 0 ||
444 accessor.InsnsSizeInCodeUnits() > kMaximumNumberOfTotalInstructions) {
445 return false;
446 }
447 // Scan for exits.
448 bool throw_seen = false;
449 for (const DexInstructionPcPair& pair : accessor) {
450 switch (pair.Inst().Opcode()) {
451 case Instruction::RETURN:
452 case Instruction::RETURN_VOID:
453 case Instruction::RETURN_WIDE:
454 case Instruction::RETURN_OBJECT:
455 case Instruction::RETURN_VOID_NO_BARRIER:
456 return false; // found regular control flow back
457 case Instruction::THROW:
458 throw_seen = true;
459 break;
460 default:
461 break;
462 }
463 }
464 return throw_seen;
465 }
466
FindActualCallTarget(HInvoke * invoke_instruction,bool * cha_devirtualize)467 ArtMethod* HInliner::FindActualCallTarget(HInvoke* invoke_instruction, bool* cha_devirtualize) {
468 ArtMethod* resolved_method = invoke_instruction->GetResolvedMethod();
469 DCHECK(resolved_method != nullptr);
470
471 ArtMethod* actual_method = nullptr;
472 if (invoke_instruction->IsInvokeStaticOrDirect()) {
473 actual_method = resolved_method;
474 } else {
475 // Check if we can statically find the method.
476 actual_method = FindVirtualOrInterfaceTarget(invoke_instruction, resolved_method);
477 }
478
479 if (actual_method == nullptr) {
480 ArtMethod* method = TryCHADevirtualization(resolved_method);
481 if (method != nullptr) {
482 *cha_devirtualize = true;
483 actual_method = method;
484 LOG_NOTE() << "Try CHA-based inlining of " << actual_method->PrettyMethod();
485 }
486 }
487
488 return actual_method;
489 }
490
TryInline(HInvoke * invoke_instruction)491 bool HInliner::TryInline(HInvoke* invoke_instruction) {
492 MaybeRecordStat(stats_, MethodCompilationStat::kTryInline);
493
494 // Don't bother to move further if we know the method is unresolved or the invocation is
495 // polymorphic (invoke-{polymorphic,custom}).
496 if (invoke_instruction->IsInvokeUnresolved()) {
497 MaybeRecordStat(stats_, MethodCompilationStat::kNotInlinedUnresolved);
498 return false;
499 } else if (invoke_instruction->IsInvokePolymorphic()) {
500 MaybeRecordStat(stats_, MethodCompilationStat::kNotInlinedPolymorphic);
501 return false;
502 } else if (invoke_instruction->IsInvokeCustom()) {
503 MaybeRecordStat(stats_, MethodCompilationStat::kNotInlinedCustom);
504 return false;
505 }
506
507 ScopedObjectAccess soa(Thread::Current());
508 uint32_t method_index = invoke_instruction->GetDexMethodIndex();
509 const DexFile& caller_dex_file = *caller_compilation_unit_.GetDexFile();
510 LOG_TRY() << caller_dex_file.PrettyMethod(method_index);
511
512 ArtMethod* resolved_method = invoke_instruction->GetResolvedMethod();
513 if (resolved_method == nullptr) {
514 DCHECK(invoke_instruction->IsInvokeStaticOrDirect());
515 DCHECK(invoke_instruction->AsInvokeStaticOrDirect()->IsStringInit());
516 LOG_FAIL_NO_STAT() << "Not inlining a String.<init> method";
517 return false;
518 }
519
520 bool cha_devirtualize = false;
521 ArtMethod* actual_method = FindActualCallTarget(invoke_instruction, &cha_devirtualize);
522
523 // If we didn't find a method, see if we can inline from the inline caches.
524 if (actual_method == nullptr) {
525 DCHECK(!invoke_instruction->IsInvokeStaticOrDirect());
526
527 return TryInlineFromInlineCache(caller_dex_file, invoke_instruction, resolved_method);
528 }
529
530 // Single target.
531 bool result = TryInlineAndReplace(invoke_instruction,
532 actual_method,
533 ReferenceTypeInfo::CreateInvalid(),
534 /* do_rtp= */ true,
535 cha_devirtualize);
536 if (result) {
537 // Successfully inlined.
538 if (!invoke_instruction->IsInvokeStaticOrDirect()) {
539 if (cha_devirtualize) {
540 // Add dependency due to devirtualization. We've assumed resolved_method
541 // has single implementation.
542 outermost_graph_->AddCHASingleImplementationDependency(resolved_method);
543 MaybeRecordStat(stats_, MethodCompilationStat::kCHAInline);
544 } else {
545 MaybeRecordStat(stats_, MethodCompilationStat::kInlinedInvokeVirtualOrInterface);
546 }
547 }
548 } else if (!cha_devirtualize && AlwaysThrows(codegen_->GetCompilerOptions(), actual_method)) {
549 // Set always throws property for non-inlined method call with single target
550 // (unless it was obtained through CHA, because that would imply we have
551 // to add the CHA dependency, which seems not worth it).
552 invoke_instruction->SetAlwaysThrows(true);
553 }
554 return result;
555 }
556
AllocateInlineCacheHolder(const DexCompilationUnit & compilation_unit,StackHandleScope<1> * hs)557 static Handle<mirror::ObjectArray<mirror::Class>> AllocateInlineCacheHolder(
558 const DexCompilationUnit& compilation_unit,
559 StackHandleScope<1>* hs)
560 REQUIRES_SHARED(Locks::mutator_lock_) {
561 Thread* self = Thread::Current();
562 ClassLinker* class_linker = compilation_unit.GetClassLinker();
563 Handle<mirror::ObjectArray<mirror::Class>> inline_cache = hs->NewHandle(
564 mirror::ObjectArray<mirror::Class>::Alloc(
565 self,
566 GetClassRoot<mirror::ObjectArray<mirror::Class>>(class_linker),
567 InlineCache::kIndividualCacheSize));
568 if (inline_cache == nullptr) {
569 // We got an OOME. Just clear the exception, and don't inline.
570 DCHECK(self->IsExceptionPending());
571 self->ClearException();
572 VLOG(compiler) << "Out of memory in the compiler when trying to inline";
573 }
574 return inline_cache;
575 }
576
UseOnlyPolymorphicInliningWithNoDeopt()577 bool HInliner::UseOnlyPolymorphicInliningWithNoDeopt() {
578 // If we are compiling AOT or OSR, pretend the call using inline caches is polymorphic and
579 // do not generate a deopt.
580 //
581 // For AOT:
582 // Generating a deopt does not ensure that we will actually capture the new types;
583 // and the danger is that we could be stuck in a loop with "forever" deoptimizations.
584 // Take for example the following scenario:
585 // - we capture the inline cache in one run
586 // - the next run, we deoptimize because we miss a type check, but the method
587 // never becomes hot again
588 // In this case, the inline cache will not be updated in the profile and the AOT code
589 // will keep deoptimizing.
590 // Another scenario is if we use profile compilation for a process which is not allowed
591 // to JIT (e.g. system server). If we deoptimize we will run interpreted code for the
592 // rest of the lifetime.
593 // TODO(calin):
594 // This is a compromise because we will most likely never update the inline cache
595 // in the profile (unless there's another reason to deopt). So we might be stuck with
596 // a sub-optimal inline cache.
597 // We could be smarter when capturing inline caches to mitigate this.
598 // (e.g. by having different thresholds for new and old methods).
599 //
600 // For OSR:
601 // We may come from the interpreter and it may have seen different receiver types.
602 return Runtime::Current()->IsAotCompiler() || outermost_graph_->IsCompilingOsr();
603 }
TryInlineFromInlineCache(const DexFile & caller_dex_file,HInvoke * invoke_instruction,ArtMethod * resolved_method)604 bool HInliner::TryInlineFromInlineCache(const DexFile& caller_dex_file,
605 HInvoke* invoke_instruction,
606 ArtMethod* resolved_method)
607 REQUIRES_SHARED(Locks::mutator_lock_) {
608 if (Runtime::Current()->IsAotCompiler() && !kUseAOTInlineCaches) {
609 return false;
610 }
611
612 StackHandleScope<1> hs(Thread::Current());
613 Handle<mirror::ObjectArray<mirror::Class>> inline_cache;
614 // The Zygote JIT compiles based on a profile, so we shouldn't use runtime inline caches
615 // for it.
616 InlineCacheType inline_cache_type =
617 (Runtime::Current()->IsAotCompiler() || Runtime::Current()->IsZygote())
618 ? GetInlineCacheAOT(caller_dex_file, invoke_instruction, &hs, &inline_cache)
619 : GetInlineCacheJIT(invoke_instruction, &hs, &inline_cache);
620
621 switch (inline_cache_type) {
622 case kInlineCacheNoData: {
623 LOG_FAIL_NO_STAT()
624 << "No inline cache information for call to "
625 << caller_dex_file.PrettyMethod(invoke_instruction->GetDexMethodIndex());
626 return false;
627 }
628
629 case kInlineCacheUninitialized: {
630 LOG_FAIL_NO_STAT()
631 << "Interface or virtual call to "
632 << caller_dex_file.PrettyMethod(invoke_instruction->GetDexMethodIndex())
633 << " is not hit and not inlined";
634 return false;
635 }
636
637 case kInlineCacheMonomorphic: {
638 MaybeRecordStat(stats_, MethodCompilationStat::kMonomorphicCall);
639 if (UseOnlyPolymorphicInliningWithNoDeopt()) {
640 return TryInlinePolymorphicCall(invoke_instruction, resolved_method, inline_cache);
641 } else {
642 return TryInlineMonomorphicCall(invoke_instruction, resolved_method, inline_cache);
643 }
644 }
645
646 case kInlineCachePolymorphic: {
647 MaybeRecordStat(stats_, MethodCompilationStat::kPolymorphicCall);
648 return TryInlinePolymorphicCall(invoke_instruction, resolved_method, inline_cache);
649 }
650
651 case kInlineCacheMegamorphic: {
652 LOG_FAIL_NO_STAT()
653 << "Interface or virtual call to "
654 << caller_dex_file.PrettyMethod(invoke_instruction->GetDexMethodIndex())
655 << " is megamorphic and not inlined";
656 MaybeRecordStat(stats_, MethodCompilationStat::kMegamorphicCall);
657 return false;
658 }
659
660 case kInlineCacheMissingTypes: {
661 LOG_FAIL_NO_STAT()
662 << "Interface or virtual call to "
663 << caller_dex_file.PrettyMethod(invoke_instruction->GetDexMethodIndex())
664 << " is missing types and not inlined";
665 return false;
666 }
667 }
668 UNREACHABLE();
669 }
670
GetInlineCacheJIT(HInvoke * invoke_instruction,StackHandleScope<1> * hs,Handle<mirror::ObjectArray<mirror::Class>> * inline_cache)671 HInliner::InlineCacheType HInliner::GetInlineCacheJIT(
672 HInvoke* invoke_instruction,
673 StackHandleScope<1>* hs,
674 /*out*/Handle<mirror::ObjectArray<mirror::Class>>* inline_cache)
675 REQUIRES_SHARED(Locks::mutator_lock_) {
676 DCHECK(codegen_->GetCompilerOptions().IsJitCompiler());
677
678 ArtMethod* caller = graph_->GetArtMethod();
679 // Under JIT, we should always know the caller.
680 DCHECK(caller != nullptr);
681 ScopedProfilingInfoInlineUse spiis(caller, Thread::Current());
682 ProfilingInfo* profiling_info = spiis.GetProfilingInfo();
683
684 if (profiling_info == nullptr) {
685 return kInlineCacheNoData;
686 }
687
688 *inline_cache = AllocateInlineCacheHolder(caller_compilation_unit_, hs);
689 if (inline_cache->Get() == nullptr) {
690 // We can't extract any data if we failed to allocate;
691 return kInlineCacheNoData;
692 } else {
693 Runtime::Current()->GetJit()->GetCodeCache()->CopyInlineCacheInto(
694 *profiling_info->GetInlineCache(invoke_instruction->GetDexPc()),
695 *inline_cache);
696 return GetInlineCacheType(*inline_cache);
697 }
698 }
699
GetInlineCacheAOT(const DexFile & caller_dex_file,HInvoke * invoke_instruction,StackHandleScope<1> * hs,Handle<mirror::ObjectArray<mirror::Class>> * inline_cache)700 HInliner::InlineCacheType HInliner::GetInlineCacheAOT(
701 const DexFile& caller_dex_file,
702 HInvoke* invoke_instruction,
703 StackHandleScope<1>* hs,
704 /*out*/Handle<mirror::ObjectArray<mirror::Class>>* inline_cache)
705 REQUIRES_SHARED(Locks::mutator_lock_) {
706 const ProfileCompilationInfo* pci = codegen_->GetCompilerOptions().GetProfileCompilationInfo();
707 if (pci == nullptr) {
708 return kInlineCacheNoData;
709 }
710
711 std::unique_ptr<ProfileCompilationInfo::OfflineProfileMethodInfo> offline_profile =
712 pci->GetHotMethodInfo(MethodReference(
713 &caller_dex_file, caller_compilation_unit_.GetDexMethodIndex()));
714 if (offline_profile == nullptr) {
715 return kInlineCacheNoData; // no profile information for this invocation.
716 }
717
718 *inline_cache = AllocateInlineCacheHolder(caller_compilation_unit_, hs);
719 if (inline_cache == nullptr) {
720 // We can't extract any data if we failed to allocate;
721 return kInlineCacheNoData;
722 } else {
723 return ExtractClassesFromOfflineProfile(invoke_instruction,
724 *(offline_profile.get()),
725 *inline_cache);
726 }
727 }
728
ExtractClassesFromOfflineProfile(const HInvoke * invoke_instruction,const ProfileCompilationInfo::OfflineProfileMethodInfo & offline_profile,Handle<mirror::ObjectArray<mirror::Class>> inline_cache)729 HInliner::InlineCacheType HInliner::ExtractClassesFromOfflineProfile(
730 const HInvoke* invoke_instruction,
731 const ProfileCompilationInfo::OfflineProfileMethodInfo& offline_profile,
732 /*out*/Handle<mirror::ObjectArray<mirror::Class>> inline_cache)
733 REQUIRES_SHARED(Locks::mutator_lock_) {
734 const auto it = offline_profile.inline_caches->find(invoke_instruction->GetDexPc());
735 if (it == offline_profile.inline_caches->end()) {
736 return kInlineCacheUninitialized;
737 }
738
739 const ProfileCompilationInfo::DexPcData& dex_pc_data = it->second;
740
741 if (dex_pc_data.is_missing_types) {
742 return kInlineCacheMissingTypes;
743 }
744 if (dex_pc_data.is_megamorphic) {
745 return kInlineCacheMegamorphic;
746 }
747
748 DCHECK_LE(dex_pc_data.classes.size(), InlineCache::kIndividualCacheSize);
749 Thread* self = Thread::Current();
750 // We need to resolve the class relative to the containing dex file.
751 // So first, build a mapping from the index of dex file in the profile to
752 // its dex cache. This will avoid repeating the lookup when walking over
753 // the inline cache types.
754 std::vector<ObjPtr<mirror::DexCache>> dex_profile_index_to_dex_cache(
755 offline_profile.dex_references.size());
756 for (size_t i = 0; i < offline_profile.dex_references.size(); i++) {
757 bool found = false;
758 for (const DexFile* dex_file : codegen_->GetCompilerOptions().GetDexFilesForOatFile()) {
759 if (offline_profile.dex_references[i].MatchesDex(dex_file)) {
760 dex_profile_index_to_dex_cache[i] =
761 caller_compilation_unit_.GetClassLinker()->FindDexCache(self, *dex_file);
762 found = true;
763 }
764 }
765 if (!found) {
766 VLOG(compiler) << "Could not find profiled dex file: " << offline_profile.dex_references[i];
767 return kInlineCacheMissingTypes;
768 }
769 }
770
771 // Walk over the classes and resolve them. If we cannot find a type we return
772 // kInlineCacheMissingTypes.
773 int ic_index = 0;
774 for (const ProfileCompilationInfo::ClassReference& class_ref : dex_pc_data.classes) {
775 ObjPtr<mirror::DexCache> dex_cache =
776 dex_profile_index_to_dex_cache[class_ref.dex_profile_index];
777 DCHECK(dex_cache != nullptr);
778
779 if (!dex_cache->GetDexFile()->IsTypeIndexValid(class_ref.type_index)) {
780 VLOG(compiler) << "Profile data corrupt: type index " << class_ref.type_index
781 << "is invalid in location" << dex_cache->GetDexFile()->GetLocation();
782 return kInlineCacheNoData;
783 }
784 ObjPtr<mirror::Class> clazz = caller_compilation_unit_.GetClassLinker()->LookupResolvedType(
785 class_ref.type_index,
786 dex_cache,
787 caller_compilation_unit_.GetClassLoader().Get());
788 if (clazz != nullptr) {
789 inline_cache->Set(ic_index++, clazz);
790 } else {
791 VLOG(compiler) << "Could not resolve class from inline cache in AOT mode "
792 << caller_compilation_unit_.GetDexFile()->PrettyMethod(
793 invoke_instruction->GetDexMethodIndex()) << " : "
794 << caller_compilation_unit_
795 .GetDexFile()->StringByTypeIdx(class_ref.type_index);
796 return kInlineCacheMissingTypes;
797 }
798 }
799 return GetInlineCacheType(inline_cache);
800 }
801
BuildGetReceiverClass(ClassLinker * class_linker,HInstruction * receiver,uint32_t dex_pc) const802 HInstanceFieldGet* HInliner::BuildGetReceiverClass(ClassLinker* class_linker,
803 HInstruction* receiver,
804 uint32_t dex_pc) const {
805 ArtField* field = GetClassRoot<mirror::Object>(class_linker)->GetInstanceField(0);
806 DCHECK_EQ(std::string(field->GetName()), "shadow$_klass_");
807 HInstanceFieldGet* result = new (graph_->GetAllocator()) HInstanceFieldGet(
808 receiver,
809 field,
810 DataType::Type::kReference,
811 field->GetOffset(),
812 field->IsVolatile(),
813 field->GetDexFieldIndex(),
814 field->GetDeclaringClass()->GetDexClassDefIndex(),
815 *field->GetDexFile(),
816 dex_pc);
817 // The class of a field is effectively final, and does not have any memory dependencies.
818 result->SetSideEffects(SideEffects::None());
819 return result;
820 }
821
ResolveMethodFromInlineCache(Handle<mirror::Class> klass,ArtMethod * resolved_method,HInstruction * invoke_instruction,PointerSize pointer_size)822 static ArtMethod* ResolveMethodFromInlineCache(Handle<mirror::Class> klass,
823 ArtMethod* resolved_method,
824 HInstruction* invoke_instruction,
825 PointerSize pointer_size)
826 REQUIRES_SHARED(Locks::mutator_lock_) {
827 if (Runtime::Current()->IsAotCompiler()) {
828 // We can get unrelated types when working with profiles (corruption,
829 // systme updates, or anyone can write to it). So first check if the class
830 // actually implements the declaring class of the method that is being
831 // called in bytecode.
832 // Note: the lookup methods used below require to have assignable types.
833 if (!resolved_method->GetDeclaringClass()->IsAssignableFrom(klass.Get())) {
834 return nullptr;
835 }
836 }
837
838 if (invoke_instruction->IsInvokeInterface()) {
839 resolved_method = klass->FindVirtualMethodForInterface(resolved_method, pointer_size);
840 } else {
841 DCHECK(invoke_instruction->IsInvokeVirtual());
842 resolved_method = klass->FindVirtualMethodForVirtual(resolved_method, pointer_size);
843 }
844 DCHECK(resolved_method != nullptr);
845 return resolved_method;
846 }
847
TryInlineMonomorphicCall(HInvoke * invoke_instruction,ArtMethod * resolved_method,Handle<mirror::ObjectArray<mirror::Class>> classes)848 bool HInliner::TryInlineMonomorphicCall(HInvoke* invoke_instruction,
849 ArtMethod* resolved_method,
850 Handle<mirror::ObjectArray<mirror::Class>> classes) {
851 DCHECK(invoke_instruction->IsInvokeVirtual() || invoke_instruction->IsInvokeInterface())
852 << invoke_instruction->DebugName();
853
854 dex::TypeIndex class_index = FindClassIndexIn(
855 GetMonomorphicType(classes), caller_compilation_unit_);
856 if (!class_index.IsValid()) {
857 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedDexCache)
858 << "Call to " << ArtMethod::PrettyMethod(resolved_method)
859 << " from inline cache is not inlined because its class is not"
860 << " accessible to the caller";
861 return false;
862 }
863
864 ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
865 PointerSize pointer_size = class_linker->GetImagePointerSize();
866 Handle<mirror::Class> monomorphic_type =
867 graph_->GetHandleCache()->NewHandle(GetMonomorphicType(classes));
868 resolved_method = ResolveMethodFromInlineCache(
869 monomorphic_type, resolved_method, invoke_instruction, pointer_size);
870
871 LOG_NOTE() << "Try inline monomorphic call to " << resolved_method->PrettyMethod();
872 if (resolved_method == nullptr) {
873 // Bogus AOT profile, bail.
874 DCHECK(Runtime::Current()->IsAotCompiler());
875 return false;
876 }
877
878 HInstruction* receiver = invoke_instruction->InputAt(0);
879 HInstruction* cursor = invoke_instruction->GetPrevious();
880 HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
881 if (!TryInlineAndReplace(invoke_instruction,
882 resolved_method,
883 ReferenceTypeInfo::Create(monomorphic_type, /* is_exact= */ true),
884 /* do_rtp= */ false,
885 /* cha_devirtualize= */ false)) {
886 return false;
887 }
888
889 // We successfully inlined, now add a guard.
890 AddTypeGuard(receiver,
891 cursor,
892 bb_cursor,
893 class_index,
894 monomorphic_type,
895 invoke_instruction,
896 /* with_deoptimization= */ true);
897
898 // Run type propagation to get the guard typed, and eventually propagate the
899 // type of the receiver.
900 ReferenceTypePropagation rtp_fixup(graph_,
901 outer_compilation_unit_.GetClassLoader(),
902 outer_compilation_unit_.GetDexCache(),
903 /* is_first_run= */ false);
904 rtp_fixup.Run();
905
906 MaybeRecordStat(stats_, MethodCompilationStat::kInlinedMonomorphicCall);
907 return true;
908 }
909
AddCHAGuard(HInstruction * invoke_instruction,uint32_t dex_pc,HInstruction * cursor,HBasicBlock * bb_cursor)910 void HInliner::AddCHAGuard(HInstruction* invoke_instruction,
911 uint32_t dex_pc,
912 HInstruction* cursor,
913 HBasicBlock* bb_cursor) {
914 HShouldDeoptimizeFlag* deopt_flag = new (graph_->GetAllocator())
915 HShouldDeoptimizeFlag(graph_->GetAllocator(), dex_pc);
916 HInstruction* compare = new (graph_->GetAllocator()) HNotEqual(
917 deopt_flag, graph_->GetIntConstant(0, dex_pc));
918 HInstruction* deopt = new (graph_->GetAllocator()) HDeoptimize(
919 graph_->GetAllocator(), compare, DeoptimizationKind::kCHA, dex_pc);
920
921 if (cursor != nullptr) {
922 bb_cursor->InsertInstructionAfter(deopt_flag, cursor);
923 } else {
924 bb_cursor->InsertInstructionBefore(deopt_flag, bb_cursor->GetFirstInstruction());
925 }
926 bb_cursor->InsertInstructionAfter(compare, deopt_flag);
927 bb_cursor->InsertInstructionAfter(deopt, compare);
928
929 // Add receiver as input to aid CHA guard optimization later.
930 deopt_flag->AddInput(invoke_instruction->InputAt(0));
931 DCHECK_EQ(deopt_flag->InputCount(), 1u);
932 deopt->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
933 outermost_graph_->IncrementNumberOfCHAGuards();
934 }
935
AddTypeGuard(HInstruction * receiver,HInstruction * cursor,HBasicBlock * bb_cursor,dex::TypeIndex class_index,Handle<mirror::Class> klass,HInstruction * invoke_instruction,bool with_deoptimization)936 HInstruction* HInliner::AddTypeGuard(HInstruction* receiver,
937 HInstruction* cursor,
938 HBasicBlock* bb_cursor,
939 dex::TypeIndex class_index,
940 Handle<mirror::Class> klass,
941 HInstruction* invoke_instruction,
942 bool with_deoptimization) {
943 ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
944 HInstanceFieldGet* receiver_class = BuildGetReceiverClass(
945 class_linker, receiver, invoke_instruction->GetDexPc());
946 if (cursor != nullptr) {
947 bb_cursor->InsertInstructionAfter(receiver_class, cursor);
948 } else {
949 bb_cursor->InsertInstructionBefore(receiver_class, bb_cursor->GetFirstInstruction());
950 }
951
952 const DexFile& caller_dex_file = *caller_compilation_unit_.GetDexFile();
953 bool is_referrer;
954 ArtMethod* outermost_art_method = outermost_graph_->GetArtMethod();
955 if (outermost_art_method == nullptr) {
956 DCHECK(Runtime::Current()->IsAotCompiler());
957 // We are in AOT mode and we don't have an ART method to determine
958 // if the inlined method belongs to the referrer. Assume it doesn't.
959 is_referrer = false;
960 } else {
961 is_referrer = klass.Get() == outermost_art_method->GetDeclaringClass();
962 }
963
964 // Note that we will just compare the classes, so we don't need Java semantics access checks.
965 // Note that the type index and the dex file are relative to the method this type guard is
966 // inlined into.
967 HLoadClass* load_class = new (graph_->GetAllocator()) HLoadClass(graph_->GetCurrentMethod(),
968 class_index,
969 caller_dex_file,
970 klass,
971 is_referrer,
972 invoke_instruction->GetDexPc(),
973 /* needs_access_check= */ false);
974 HLoadClass::LoadKind kind = HSharpening::ComputeLoadClassKind(
975 load_class, codegen_, caller_compilation_unit_);
976 DCHECK(kind != HLoadClass::LoadKind::kInvalid)
977 << "We should always be able to reference a class for inline caches";
978 // Load kind must be set before inserting the instruction into the graph.
979 load_class->SetLoadKind(kind);
980 bb_cursor->InsertInstructionAfter(load_class, receiver_class);
981 // In AOT mode, we will most likely load the class from BSS, which will involve a call
982 // to the runtime. In this case, the load instruction will need an environment so copy
983 // it from the invoke instruction.
984 if (load_class->NeedsEnvironment()) {
985 DCHECK(Runtime::Current()->IsAotCompiler());
986 load_class->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
987 }
988
989 HNotEqual* compare = new (graph_->GetAllocator()) HNotEqual(load_class, receiver_class);
990 bb_cursor->InsertInstructionAfter(compare, load_class);
991 if (with_deoptimization) {
992 HDeoptimize* deoptimize = new (graph_->GetAllocator()) HDeoptimize(
993 graph_->GetAllocator(),
994 compare,
995 receiver,
996 Runtime::Current()->IsAotCompiler()
997 ? DeoptimizationKind::kAotInlineCache
998 : DeoptimizationKind::kJitInlineCache,
999 invoke_instruction->GetDexPc());
1000 bb_cursor->InsertInstructionAfter(deoptimize, compare);
1001 deoptimize->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
1002 DCHECK_EQ(invoke_instruction->InputAt(0), receiver);
1003 receiver->ReplaceUsesDominatedBy(deoptimize, deoptimize);
1004 deoptimize->SetReferenceTypeInfo(receiver->GetReferenceTypeInfo());
1005 }
1006 return compare;
1007 }
1008
TryInlinePolymorphicCall(HInvoke * invoke_instruction,ArtMethod * resolved_method,Handle<mirror::ObjectArray<mirror::Class>> classes)1009 bool HInliner::TryInlinePolymorphicCall(HInvoke* invoke_instruction,
1010 ArtMethod* resolved_method,
1011 Handle<mirror::ObjectArray<mirror::Class>> classes) {
1012 DCHECK(invoke_instruction->IsInvokeVirtual() || invoke_instruction->IsInvokeInterface())
1013 << invoke_instruction->DebugName();
1014
1015 if (TryInlinePolymorphicCallToSameTarget(invoke_instruction, resolved_method, classes)) {
1016 return true;
1017 }
1018
1019 ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
1020 PointerSize pointer_size = class_linker->GetImagePointerSize();
1021
1022 bool all_targets_inlined = true;
1023 bool one_target_inlined = false;
1024 for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) {
1025 if (classes->Get(i) == nullptr) {
1026 break;
1027 }
1028 ArtMethod* method = nullptr;
1029
1030 Handle<mirror::Class> handle = graph_->GetHandleCache()->NewHandle(classes->Get(i));
1031 method = ResolveMethodFromInlineCache(
1032 handle, resolved_method, invoke_instruction, pointer_size);
1033 if (method == nullptr) {
1034 DCHECK(Runtime::Current()->IsAotCompiler());
1035 // AOT profile is bogus. This loop expects to iterate over all entries,
1036 // so just just continue.
1037 all_targets_inlined = false;
1038 continue;
1039 }
1040
1041 HInstruction* receiver = invoke_instruction->InputAt(0);
1042 HInstruction* cursor = invoke_instruction->GetPrevious();
1043 HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
1044
1045 dex::TypeIndex class_index = FindClassIndexIn(handle.Get(), caller_compilation_unit_);
1046 HInstruction* return_replacement = nullptr;
1047 LOG_NOTE() << "Try inline polymorphic call to " << method->PrettyMethod();
1048 if (!class_index.IsValid() ||
1049 !TryBuildAndInline(invoke_instruction,
1050 method,
1051 ReferenceTypeInfo::Create(handle, /* is_exact= */ true),
1052 &return_replacement)) {
1053 all_targets_inlined = false;
1054 } else {
1055 one_target_inlined = true;
1056
1057 LOG_SUCCESS() << "Polymorphic call to " << ArtMethod::PrettyMethod(resolved_method)
1058 << " has inlined " << ArtMethod::PrettyMethod(method);
1059
1060 // If we have inlined all targets before, and this receiver is the last seen,
1061 // we deoptimize instead of keeping the original invoke instruction.
1062 bool deoptimize = !UseOnlyPolymorphicInliningWithNoDeopt() &&
1063 all_targets_inlined &&
1064 (i != InlineCache::kIndividualCacheSize - 1) &&
1065 (classes->Get(i + 1) == nullptr);
1066
1067 HInstruction* compare = AddTypeGuard(receiver,
1068 cursor,
1069 bb_cursor,
1070 class_index,
1071 handle,
1072 invoke_instruction,
1073 deoptimize);
1074 if (deoptimize) {
1075 if (return_replacement != nullptr) {
1076 invoke_instruction->ReplaceWith(return_replacement);
1077 }
1078 invoke_instruction->GetBlock()->RemoveInstruction(invoke_instruction);
1079 // Because the inline cache data can be populated concurrently, we force the end of the
1080 // iteration. Otherwise, we could see a new receiver type.
1081 break;
1082 } else {
1083 CreateDiamondPatternForPolymorphicInline(compare, return_replacement, invoke_instruction);
1084 }
1085 }
1086 }
1087
1088 if (!one_target_inlined) {
1089 LOG_FAIL_NO_STAT()
1090 << "Call to " << ArtMethod::PrettyMethod(resolved_method)
1091 << " from inline cache is not inlined because none"
1092 << " of its targets could be inlined";
1093 return false;
1094 }
1095
1096 MaybeRecordStat(stats_, MethodCompilationStat::kInlinedPolymorphicCall);
1097
1098 // Run type propagation to get the guards typed.
1099 ReferenceTypePropagation rtp_fixup(graph_,
1100 outer_compilation_unit_.GetClassLoader(),
1101 outer_compilation_unit_.GetDexCache(),
1102 /* is_first_run= */ false);
1103 rtp_fixup.Run();
1104 return true;
1105 }
1106
CreateDiamondPatternForPolymorphicInline(HInstruction * compare,HInstruction * return_replacement,HInstruction * invoke_instruction)1107 void HInliner::CreateDiamondPatternForPolymorphicInline(HInstruction* compare,
1108 HInstruction* return_replacement,
1109 HInstruction* invoke_instruction) {
1110 uint32_t dex_pc = invoke_instruction->GetDexPc();
1111 HBasicBlock* cursor_block = compare->GetBlock();
1112 HBasicBlock* original_invoke_block = invoke_instruction->GetBlock();
1113 ArenaAllocator* allocator = graph_->GetAllocator();
1114
1115 // Spit the block after the compare: `cursor_block` will now be the start of the diamond,
1116 // and the returned block is the start of the then branch (that could contain multiple blocks).
1117 HBasicBlock* then = cursor_block->SplitAfterForInlining(compare);
1118
1119 // Split the block containing the invoke before and after the invoke. The returned block
1120 // of the split before will contain the invoke and will be the otherwise branch of
1121 // the diamond. The returned block of the split after will be the merge block
1122 // of the diamond.
1123 HBasicBlock* end_then = invoke_instruction->GetBlock();
1124 HBasicBlock* otherwise = end_then->SplitBeforeForInlining(invoke_instruction);
1125 HBasicBlock* merge = otherwise->SplitAfterForInlining(invoke_instruction);
1126
1127 // If the methods we are inlining return a value, we create a phi in the merge block
1128 // that will have the `invoke_instruction and the `return_replacement` as inputs.
1129 if (return_replacement != nullptr) {
1130 HPhi* phi = new (allocator) HPhi(
1131 allocator, kNoRegNumber, 0, HPhi::ToPhiType(invoke_instruction->GetType()), dex_pc);
1132 merge->AddPhi(phi);
1133 invoke_instruction->ReplaceWith(phi);
1134 phi->AddInput(return_replacement);
1135 phi->AddInput(invoke_instruction);
1136 }
1137
1138 // Add the control flow instructions.
1139 otherwise->AddInstruction(new (allocator) HGoto(dex_pc));
1140 end_then->AddInstruction(new (allocator) HGoto(dex_pc));
1141 cursor_block->AddInstruction(new (allocator) HIf(compare, dex_pc));
1142
1143 // Add the newly created blocks to the graph.
1144 graph_->AddBlock(then);
1145 graph_->AddBlock(otherwise);
1146 graph_->AddBlock(merge);
1147
1148 // Set up successor (and implictly predecessor) relations.
1149 cursor_block->AddSuccessor(otherwise);
1150 cursor_block->AddSuccessor(then);
1151 end_then->AddSuccessor(merge);
1152 otherwise->AddSuccessor(merge);
1153
1154 // Set up dominance information.
1155 then->SetDominator(cursor_block);
1156 cursor_block->AddDominatedBlock(then);
1157 otherwise->SetDominator(cursor_block);
1158 cursor_block->AddDominatedBlock(otherwise);
1159 merge->SetDominator(cursor_block);
1160 cursor_block->AddDominatedBlock(merge);
1161
1162 // Update the revert post order.
1163 size_t index = IndexOfElement(graph_->reverse_post_order_, cursor_block);
1164 MakeRoomFor(&graph_->reverse_post_order_, 1, index);
1165 graph_->reverse_post_order_[++index] = then;
1166 index = IndexOfElement(graph_->reverse_post_order_, end_then);
1167 MakeRoomFor(&graph_->reverse_post_order_, 2, index);
1168 graph_->reverse_post_order_[++index] = otherwise;
1169 graph_->reverse_post_order_[++index] = merge;
1170
1171
1172 graph_->UpdateLoopAndTryInformationOfNewBlock(
1173 then, original_invoke_block, /* replace_if_back_edge= */ false);
1174 graph_->UpdateLoopAndTryInformationOfNewBlock(
1175 otherwise, original_invoke_block, /* replace_if_back_edge= */ false);
1176
1177 // In case the original invoke location was a back edge, we need to update
1178 // the loop to now have the merge block as a back edge.
1179 graph_->UpdateLoopAndTryInformationOfNewBlock(
1180 merge, original_invoke_block, /* replace_if_back_edge= */ true);
1181 }
1182
TryInlinePolymorphicCallToSameTarget(HInvoke * invoke_instruction,ArtMethod * resolved_method,Handle<mirror::ObjectArray<mirror::Class>> classes)1183 bool HInliner::TryInlinePolymorphicCallToSameTarget(
1184 HInvoke* invoke_instruction,
1185 ArtMethod* resolved_method,
1186 Handle<mirror::ObjectArray<mirror::Class>> classes) {
1187 // This optimization only works under JIT for now.
1188 if (!codegen_->GetCompilerOptions().IsJitCompiler()) {
1189 return false;
1190 }
1191
1192 ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
1193 PointerSize pointer_size = class_linker->GetImagePointerSize();
1194
1195 DCHECK(resolved_method != nullptr);
1196 ArtMethod* actual_method = nullptr;
1197 size_t method_index = invoke_instruction->IsInvokeVirtual()
1198 ? invoke_instruction->AsInvokeVirtual()->GetVTableIndex()
1199 : invoke_instruction->AsInvokeInterface()->GetImtIndex();
1200
1201 // Check whether we are actually calling the same method among
1202 // the different types seen.
1203 for (size_t i = 0; i < InlineCache::kIndividualCacheSize; ++i) {
1204 if (classes->Get(i) == nullptr) {
1205 break;
1206 }
1207 ArtMethod* new_method = nullptr;
1208 if (invoke_instruction->IsInvokeInterface()) {
1209 new_method = classes->Get(i)->GetImt(pointer_size)->Get(
1210 method_index, pointer_size);
1211 if (new_method->IsRuntimeMethod()) {
1212 // Bail out as soon as we see a conflict trampoline in one of the target's
1213 // interface table.
1214 return false;
1215 }
1216 } else {
1217 DCHECK(invoke_instruction->IsInvokeVirtual());
1218 new_method = classes->Get(i)->GetEmbeddedVTableEntry(method_index, pointer_size);
1219 }
1220 DCHECK(new_method != nullptr);
1221 if (actual_method == nullptr) {
1222 actual_method = new_method;
1223 } else if (actual_method != new_method) {
1224 // Different methods, bailout.
1225 return false;
1226 }
1227 }
1228
1229 HInstruction* receiver = invoke_instruction->InputAt(0);
1230 HInstruction* cursor = invoke_instruction->GetPrevious();
1231 HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
1232
1233 HInstruction* return_replacement = nullptr;
1234 if (!TryBuildAndInline(invoke_instruction,
1235 actual_method,
1236 ReferenceTypeInfo::CreateInvalid(),
1237 &return_replacement)) {
1238 return false;
1239 }
1240
1241 // We successfully inlined, now add a guard.
1242 HInstanceFieldGet* receiver_class = BuildGetReceiverClass(
1243 class_linker, receiver, invoke_instruction->GetDexPc());
1244
1245 DataType::Type type = Is64BitInstructionSet(graph_->GetInstructionSet())
1246 ? DataType::Type::kInt64
1247 : DataType::Type::kInt32;
1248 HClassTableGet* class_table_get = new (graph_->GetAllocator()) HClassTableGet(
1249 receiver_class,
1250 type,
1251 invoke_instruction->IsInvokeVirtual() ? HClassTableGet::TableKind::kVTable
1252 : HClassTableGet::TableKind::kIMTable,
1253 method_index,
1254 invoke_instruction->GetDexPc());
1255
1256 HConstant* constant;
1257 if (type == DataType::Type::kInt64) {
1258 constant = graph_->GetLongConstant(
1259 reinterpret_cast<intptr_t>(actual_method), invoke_instruction->GetDexPc());
1260 } else {
1261 constant = graph_->GetIntConstant(
1262 reinterpret_cast<intptr_t>(actual_method), invoke_instruction->GetDexPc());
1263 }
1264
1265 HNotEqual* compare = new (graph_->GetAllocator()) HNotEqual(class_table_get, constant);
1266 if (cursor != nullptr) {
1267 bb_cursor->InsertInstructionAfter(receiver_class, cursor);
1268 } else {
1269 bb_cursor->InsertInstructionBefore(receiver_class, bb_cursor->GetFirstInstruction());
1270 }
1271 bb_cursor->InsertInstructionAfter(class_table_get, receiver_class);
1272 bb_cursor->InsertInstructionAfter(compare, class_table_get);
1273
1274 if (outermost_graph_->IsCompilingOsr()) {
1275 CreateDiamondPatternForPolymorphicInline(compare, return_replacement, invoke_instruction);
1276 } else {
1277 HDeoptimize* deoptimize = new (graph_->GetAllocator()) HDeoptimize(
1278 graph_->GetAllocator(),
1279 compare,
1280 receiver,
1281 DeoptimizationKind::kJitSameTarget,
1282 invoke_instruction->GetDexPc());
1283 bb_cursor->InsertInstructionAfter(deoptimize, compare);
1284 deoptimize->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
1285 if (return_replacement != nullptr) {
1286 invoke_instruction->ReplaceWith(return_replacement);
1287 }
1288 receiver->ReplaceUsesDominatedBy(deoptimize, deoptimize);
1289 invoke_instruction->GetBlock()->RemoveInstruction(invoke_instruction);
1290 deoptimize->SetReferenceTypeInfo(receiver->GetReferenceTypeInfo());
1291 }
1292
1293 // Run type propagation to get the guard typed.
1294 ReferenceTypePropagation rtp_fixup(graph_,
1295 outer_compilation_unit_.GetClassLoader(),
1296 outer_compilation_unit_.GetDexCache(),
1297 /* is_first_run= */ false);
1298 rtp_fixup.Run();
1299
1300 MaybeRecordStat(stats_, MethodCompilationStat::kInlinedPolymorphicCall);
1301
1302 LOG_SUCCESS() << "Inlined same polymorphic target " << actual_method->PrettyMethod();
1303 return true;
1304 }
1305
TryInlineAndReplace(HInvoke * invoke_instruction,ArtMethod * method,ReferenceTypeInfo receiver_type,bool do_rtp,bool cha_devirtualize)1306 bool HInliner::TryInlineAndReplace(HInvoke* invoke_instruction,
1307 ArtMethod* method,
1308 ReferenceTypeInfo receiver_type,
1309 bool do_rtp,
1310 bool cha_devirtualize) {
1311 DCHECK(!invoke_instruction->IsIntrinsic());
1312 HInstruction* return_replacement = nullptr;
1313 uint32_t dex_pc = invoke_instruction->GetDexPc();
1314 HInstruction* cursor = invoke_instruction->GetPrevious();
1315 HBasicBlock* bb_cursor = invoke_instruction->GetBlock();
1316 bool should_remove_invoke_instruction = false;
1317
1318 // If invoke_instruction is devirtualized to a different method, give intrinsics
1319 // another chance before we try to inline it.
1320 if (invoke_instruction->GetResolvedMethod() != method && method->IsIntrinsic()) {
1321 MaybeRecordStat(stats_, MethodCompilationStat::kIntrinsicRecognized);
1322 if (invoke_instruction->IsInvokeInterface()) {
1323 // We don't intrinsify an invoke-interface directly.
1324 // Replace the invoke-interface with an invoke-virtual.
1325 HInvokeVirtual* new_invoke = new (graph_->GetAllocator()) HInvokeVirtual(
1326 graph_->GetAllocator(),
1327 invoke_instruction->GetNumberOfArguments(),
1328 invoke_instruction->GetType(),
1329 invoke_instruction->GetDexPc(),
1330 invoke_instruction->GetDexMethodIndex(), // Use interface method's dex method index.
1331 method,
1332 method->GetMethodIndex());
1333 DCHECK_NE(new_invoke->GetIntrinsic(), Intrinsics::kNone);
1334 HInputsRef inputs = invoke_instruction->GetInputs();
1335 for (size_t index = 0; index != inputs.size(); ++index) {
1336 new_invoke->SetArgumentAt(index, inputs[index]);
1337 }
1338 invoke_instruction->GetBlock()->InsertInstructionBefore(new_invoke, invoke_instruction);
1339 new_invoke->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
1340 if (invoke_instruction->GetType() == DataType::Type::kReference) {
1341 new_invoke->SetReferenceTypeInfo(invoke_instruction->GetReferenceTypeInfo());
1342 }
1343 return_replacement = new_invoke;
1344 // invoke_instruction is replaced with new_invoke.
1345 should_remove_invoke_instruction = true;
1346 } else {
1347 invoke_instruction->SetResolvedMethod(method);
1348 }
1349 } else if (!TryBuildAndInline(invoke_instruction, method, receiver_type, &return_replacement)) {
1350 if (invoke_instruction->IsInvokeInterface()) {
1351 DCHECK(!method->IsProxyMethod());
1352 // Turn an invoke-interface into an invoke-virtual. An invoke-virtual is always
1353 // better than an invoke-interface because:
1354 // 1) In the best case, the interface call has one more indirection (to fetch the IMT).
1355 // 2) We will not go to the conflict trampoline with an invoke-virtual.
1356 // TODO: Consider sharpening once it is not dependent on the compiler driver.
1357
1358 if (method->IsDefault() && !method->IsCopied()) {
1359 // Changing to invoke-virtual cannot be done on an original default method
1360 // since it's not in any vtable. Devirtualization by exact type/inline-cache
1361 // always uses a method in the iftable which is never an original default
1362 // method.
1363 // On the other hand, inlining an original default method by CHA is fine.
1364 DCHECK(cha_devirtualize);
1365 return false;
1366 }
1367
1368 const DexFile& caller_dex_file = *caller_compilation_unit_.GetDexFile();
1369 uint32_t dex_method_index = FindMethodIndexIn(
1370 method, caller_dex_file, invoke_instruction->GetDexMethodIndex());
1371 if (dex_method_index == dex::kDexNoIndex) {
1372 return false;
1373 }
1374 HInvokeVirtual* new_invoke = new (graph_->GetAllocator()) HInvokeVirtual(
1375 graph_->GetAllocator(),
1376 invoke_instruction->GetNumberOfArguments(),
1377 invoke_instruction->GetType(),
1378 invoke_instruction->GetDexPc(),
1379 dex_method_index,
1380 method,
1381 method->GetMethodIndex());
1382 HInputsRef inputs = invoke_instruction->GetInputs();
1383 for (size_t index = 0; index != inputs.size(); ++index) {
1384 new_invoke->SetArgumentAt(index, inputs[index]);
1385 }
1386 invoke_instruction->GetBlock()->InsertInstructionBefore(new_invoke, invoke_instruction);
1387 new_invoke->CopyEnvironmentFrom(invoke_instruction->GetEnvironment());
1388 if (invoke_instruction->GetType() == DataType::Type::kReference) {
1389 new_invoke->SetReferenceTypeInfo(invoke_instruction->GetReferenceTypeInfo());
1390 }
1391 return_replacement = new_invoke;
1392 // invoke_instruction is replaced with new_invoke.
1393 should_remove_invoke_instruction = true;
1394 } else {
1395 // TODO: Consider sharpening an invoke virtual once it is not dependent on the
1396 // compiler driver.
1397 return false;
1398 }
1399 } else {
1400 // invoke_instruction is inlined.
1401 should_remove_invoke_instruction = true;
1402 }
1403
1404 if (cha_devirtualize) {
1405 AddCHAGuard(invoke_instruction, dex_pc, cursor, bb_cursor);
1406 }
1407 if (return_replacement != nullptr) {
1408 invoke_instruction->ReplaceWith(return_replacement);
1409 }
1410 if (should_remove_invoke_instruction) {
1411 invoke_instruction->GetBlock()->RemoveInstruction(invoke_instruction);
1412 }
1413 FixUpReturnReferenceType(method, return_replacement);
1414 if (do_rtp && ReturnTypeMoreSpecific(invoke_instruction, return_replacement)) {
1415 // Actual return value has a more specific type than the method's declared
1416 // return type. Run RTP again on the outer graph to propagate it.
1417 ReferenceTypePropagation(graph_,
1418 outer_compilation_unit_.GetClassLoader(),
1419 outer_compilation_unit_.GetDexCache(),
1420 /* is_first_run= */ false).Run();
1421 }
1422 return true;
1423 }
1424
CountRecursiveCallsOf(ArtMethod * method) const1425 size_t HInliner::CountRecursiveCallsOf(ArtMethod* method) const {
1426 const HInliner* current = this;
1427 size_t count = 0;
1428 do {
1429 if (current->graph_->GetArtMethod() == method) {
1430 ++count;
1431 }
1432 current = current->parent_;
1433 } while (current != nullptr);
1434 return count;
1435 }
1436
MayInline(const CompilerOptions & compiler_options,const DexFile & inlined_from,const DexFile & inlined_into)1437 static inline bool MayInline(const CompilerOptions& compiler_options,
1438 const DexFile& inlined_from,
1439 const DexFile& inlined_into) {
1440 // We're not allowed to inline across dex files if we're the no-inline-from dex file.
1441 if (!IsSameDexFile(inlined_from, inlined_into) &&
1442 ContainsElement(compiler_options.GetNoInlineFromDexFile(), &inlined_from)) {
1443 return false;
1444 }
1445
1446 return true;
1447 }
1448
1449 // Returns whether inlining is allowed based on ART semantics.
IsInliningAllowed(ArtMethod * method,const CodeItemDataAccessor & accessor) const1450 bool HInliner::IsInliningAllowed(ArtMethod* method, const CodeItemDataAccessor& accessor) const {
1451 if (!accessor.HasCodeItem()) {
1452 LOG_FAIL_NO_STAT()
1453 << "Method " << method->PrettyMethod() << " is not inlined because it is native";
1454 return false;
1455 }
1456
1457 if (!method->IsCompilable()) {
1458 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedNotVerified)
1459 << "Method " << method->PrettyMethod()
1460 << " has soft failures un-handled by the compiler, so it cannot be inlined";
1461 return false;
1462 }
1463
1464 if (IsMethodUnverified(codegen_->GetCompilerOptions(), method)) {
1465 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedNotVerified)
1466 << "Method " << method->PrettyMethod()
1467 << " couldn't be verified, so it cannot be inlined";
1468 return false;
1469 }
1470
1471 return true;
1472 }
1473
1474 // Returns whether ART supports inlining this method.
1475 //
1476 // Some methods are not supported because they have features for which inlining
1477 // is not implemented. For example, we do not currently support inlining throw
1478 // instructions into a try block.
IsInliningSupported(const HInvoke * invoke_instruction,ArtMethod * method,const CodeItemDataAccessor & accessor) const1479 bool HInliner::IsInliningSupported(const HInvoke* invoke_instruction,
1480 ArtMethod* method,
1481 const CodeItemDataAccessor& accessor) const {
1482 if (method->IsProxyMethod()) {
1483 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedProxy)
1484 << "Method " << method->PrettyMethod()
1485 << " is not inlined because of unimplemented inline support for proxy methods.";
1486 return false;
1487 }
1488
1489 if (accessor.TriesSize() != 0) {
1490 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedTryCatch)
1491 << "Method " << method->PrettyMethod() << " is not inlined because of try block";
1492 return false;
1493 }
1494
1495 if (invoke_instruction->IsInvokeStaticOrDirect() &&
1496 invoke_instruction->AsInvokeStaticOrDirect()->IsStaticWithImplicitClinitCheck()) {
1497 // Case of a static method that cannot be inlined because it implicitly
1498 // requires an initialization check of its declaring class.
1499 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedDexCache)
1500 << "Method " << method->PrettyMethod()
1501 << " is not inlined because it is static and requires a clinit"
1502 << " check that cannot be emitted due to Dex cache limitations";
1503 return false;
1504 }
1505
1506 return true;
1507 }
1508
1509 // Returns whether our resource limits allow inlining this method.
IsInliningBudgetAvailable(ArtMethod * method,const CodeItemDataAccessor & accessor) const1510 bool HInliner::IsInliningBudgetAvailable(ArtMethod* method,
1511 const CodeItemDataAccessor& accessor) const {
1512 if (CountRecursiveCallsOf(method) > kMaximumNumberOfRecursiveCalls) {
1513 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedRecursiveBudget)
1514 << "Method "
1515 << method->PrettyMethod()
1516 << " is not inlined because it has reached its recursive call budget.";
1517 return false;
1518 }
1519
1520 size_t inline_max_code_units = codegen_->GetCompilerOptions().GetInlineMaxCodeUnits();
1521 if (accessor.InsnsSizeInCodeUnits() > inline_max_code_units) {
1522 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedCodeItem)
1523 << "Method " << method->PrettyMethod()
1524 << " is not inlined because its code item is too big: "
1525 << accessor.InsnsSizeInCodeUnits()
1526 << " > "
1527 << inline_max_code_units;
1528 return false;
1529 }
1530
1531 return true;
1532 }
1533
TryBuildAndInline(HInvoke * invoke_instruction,ArtMethod * method,ReferenceTypeInfo receiver_type,HInstruction ** return_replacement)1534 bool HInliner::TryBuildAndInline(HInvoke* invoke_instruction,
1535 ArtMethod* method,
1536 ReferenceTypeInfo receiver_type,
1537 HInstruction** return_replacement) {
1538 // Check whether we're allowed to inline. The outermost compilation unit is the relevant
1539 // dex file here (though the transitivity of an inline chain would allow checking the caller).
1540 if (!MayInline(codegen_->GetCompilerOptions(),
1541 *method->GetDexFile(),
1542 *outer_compilation_unit_.GetDexFile())) {
1543 if (TryPatternSubstitution(invoke_instruction, method, return_replacement)) {
1544 LOG_SUCCESS() << "Successfully replaced pattern of invoke "
1545 << method->PrettyMethod();
1546 MaybeRecordStat(stats_, MethodCompilationStat::kReplacedInvokeWithSimplePattern);
1547 return true;
1548 }
1549 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedWont)
1550 << "Won't inline " << method->PrettyMethod() << " in "
1551 << outer_compilation_unit_.GetDexFile()->GetLocation() << " ("
1552 << caller_compilation_unit_.GetDexFile()->GetLocation() << ") from "
1553 << method->GetDexFile()->GetLocation();
1554 return false;
1555 }
1556
1557 CodeItemDataAccessor accessor(method->DexInstructionData());
1558
1559 if (!IsInliningAllowed(method, accessor)) {
1560 return false;
1561 }
1562
1563 if (!IsInliningSupported(invoke_instruction, method, accessor)) {
1564 return false;
1565 }
1566
1567 if (!IsInliningBudgetAvailable(method, accessor)) {
1568 return false;
1569 }
1570
1571 if (!TryBuildAndInlineHelper(
1572 invoke_instruction, method, receiver_type, return_replacement)) {
1573 return false;
1574 }
1575
1576 LOG_SUCCESS() << method->PrettyMethod();
1577 MaybeRecordStat(stats_, MethodCompilationStat::kInlinedInvoke);
1578 return true;
1579 }
1580
GetInvokeInputForArgVRegIndex(HInvoke * invoke_instruction,size_t arg_vreg_index)1581 static HInstruction* GetInvokeInputForArgVRegIndex(HInvoke* invoke_instruction,
1582 size_t arg_vreg_index)
1583 REQUIRES_SHARED(Locks::mutator_lock_) {
1584 size_t input_index = 0;
1585 for (size_t i = 0; i < arg_vreg_index; ++i, ++input_index) {
1586 DCHECK_LT(input_index, invoke_instruction->GetNumberOfArguments());
1587 if (DataType::Is64BitType(invoke_instruction->InputAt(input_index)->GetType())) {
1588 ++i;
1589 DCHECK_NE(i, arg_vreg_index);
1590 }
1591 }
1592 DCHECK_LT(input_index, invoke_instruction->GetNumberOfArguments());
1593 return invoke_instruction->InputAt(input_index);
1594 }
1595
1596 // Try to recognize known simple patterns and replace invoke call with appropriate instructions.
TryPatternSubstitution(HInvoke * invoke_instruction,ArtMethod * resolved_method,HInstruction ** return_replacement)1597 bool HInliner::TryPatternSubstitution(HInvoke* invoke_instruction,
1598 ArtMethod* resolved_method,
1599 HInstruction** return_replacement) {
1600 InlineMethod inline_method;
1601 if (!InlineMethodAnalyser::AnalyseMethodCode(resolved_method, &inline_method)) {
1602 return false;
1603 }
1604
1605 switch (inline_method.opcode) {
1606 case kInlineOpNop:
1607 DCHECK_EQ(invoke_instruction->GetType(), DataType::Type::kVoid);
1608 *return_replacement = nullptr;
1609 break;
1610 case kInlineOpReturnArg:
1611 *return_replacement = GetInvokeInputForArgVRegIndex(invoke_instruction,
1612 inline_method.d.return_data.arg);
1613 break;
1614 case kInlineOpNonWideConst:
1615 if (resolved_method->GetShorty()[0] == 'L') {
1616 DCHECK_EQ(inline_method.d.data, 0u);
1617 *return_replacement = graph_->GetNullConstant();
1618 } else {
1619 *return_replacement = graph_->GetIntConstant(static_cast<int32_t>(inline_method.d.data));
1620 }
1621 break;
1622 case kInlineOpIGet: {
1623 const InlineIGetIPutData& data = inline_method.d.ifield_data;
1624 if (data.method_is_static || data.object_arg != 0u) {
1625 // TODO: Needs null check.
1626 return false;
1627 }
1628 HInstruction* obj = GetInvokeInputForArgVRegIndex(invoke_instruction, data.object_arg);
1629 HInstanceFieldGet* iget = CreateInstanceFieldGet(data.field_idx, resolved_method, obj);
1630 DCHECK_EQ(iget->GetFieldOffset().Uint32Value(), data.field_offset);
1631 DCHECK_EQ(iget->IsVolatile() ? 1u : 0u, data.is_volatile);
1632 invoke_instruction->GetBlock()->InsertInstructionBefore(iget, invoke_instruction);
1633 *return_replacement = iget;
1634 break;
1635 }
1636 case kInlineOpIPut: {
1637 const InlineIGetIPutData& data = inline_method.d.ifield_data;
1638 if (data.method_is_static || data.object_arg != 0u) {
1639 // TODO: Needs null check.
1640 return false;
1641 }
1642 HInstruction* obj = GetInvokeInputForArgVRegIndex(invoke_instruction, data.object_arg);
1643 HInstruction* value = GetInvokeInputForArgVRegIndex(invoke_instruction, data.src_arg);
1644 HInstanceFieldSet* iput = CreateInstanceFieldSet(data.field_idx, resolved_method, obj, value);
1645 DCHECK_EQ(iput->GetFieldOffset().Uint32Value(), data.field_offset);
1646 DCHECK_EQ(iput->IsVolatile() ? 1u : 0u, data.is_volatile);
1647 invoke_instruction->GetBlock()->InsertInstructionBefore(iput, invoke_instruction);
1648 if (data.return_arg_plus1 != 0u) {
1649 size_t return_arg = data.return_arg_plus1 - 1u;
1650 *return_replacement = GetInvokeInputForArgVRegIndex(invoke_instruction, return_arg);
1651 }
1652 break;
1653 }
1654 case kInlineOpConstructor: {
1655 const InlineConstructorData& data = inline_method.d.constructor_data;
1656 // Get the indexes to arrays for easier processing.
1657 uint16_t iput_field_indexes[] = {
1658 data.iput0_field_index, data.iput1_field_index, data.iput2_field_index
1659 };
1660 uint16_t iput_args[] = { data.iput0_arg, data.iput1_arg, data.iput2_arg };
1661 static_assert(arraysize(iput_args) == arraysize(iput_field_indexes), "Size mismatch");
1662 // Count valid field indexes.
1663 size_t number_of_iputs = 0u;
1664 while (number_of_iputs != arraysize(iput_field_indexes) &&
1665 iput_field_indexes[number_of_iputs] != DexFile::kDexNoIndex16) {
1666 // Check that there are no duplicate valid field indexes.
1667 DCHECK_EQ(0, std::count(iput_field_indexes + number_of_iputs + 1,
1668 iput_field_indexes + arraysize(iput_field_indexes),
1669 iput_field_indexes[number_of_iputs]));
1670 ++number_of_iputs;
1671 }
1672 // Check that there are no valid field indexes in the rest of the array.
1673 DCHECK_EQ(0, std::count_if(iput_field_indexes + number_of_iputs,
1674 iput_field_indexes + arraysize(iput_field_indexes),
1675 [](uint16_t index) { return index != DexFile::kDexNoIndex16; }));
1676
1677 // Create HInstanceFieldSet for each IPUT that stores non-zero data.
1678 HInstruction* obj = GetInvokeInputForArgVRegIndex(invoke_instruction,
1679 /* arg_vreg_index= */ 0u);
1680 bool needs_constructor_barrier = false;
1681 for (size_t i = 0; i != number_of_iputs; ++i) {
1682 HInstruction* value = GetInvokeInputForArgVRegIndex(invoke_instruction, iput_args[i]);
1683 if (!value->IsConstant() || !value->AsConstant()->IsZeroBitPattern()) {
1684 uint16_t field_index = iput_field_indexes[i];
1685 bool is_final;
1686 HInstanceFieldSet* iput =
1687 CreateInstanceFieldSet(field_index, resolved_method, obj, value, &is_final);
1688 invoke_instruction->GetBlock()->InsertInstructionBefore(iput, invoke_instruction);
1689
1690 // Check whether the field is final. If it is, we need to add a barrier.
1691 if (is_final) {
1692 needs_constructor_barrier = true;
1693 }
1694 }
1695 }
1696 if (needs_constructor_barrier) {
1697 // See DexCompilationUnit::RequiresConstructorBarrier for more details.
1698 DCHECK(obj != nullptr) << "only non-static methods can have a constructor fence";
1699
1700 HConstructorFence* constructor_fence =
1701 new (graph_->GetAllocator()) HConstructorFence(obj, kNoDexPc, graph_->GetAllocator());
1702 invoke_instruction->GetBlock()->InsertInstructionBefore(constructor_fence,
1703 invoke_instruction);
1704 }
1705 *return_replacement = nullptr;
1706 break;
1707 }
1708 default:
1709 LOG(FATAL) << "UNREACHABLE";
1710 UNREACHABLE();
1711 }
1712 return true;
1713 }
1714
CreateInstanceFieldGet(uint32_t field_index,ArtMethod * referrer,HInstruction * obj)1715 HInstanceFieldGet* HInliner::CreateInstanceFieldGet(uint32_t field_index,
1716 ArtMethod* referrer,
1717 HInstruction* obj)
1718 REQUIRES_SHARED(Locks::mutator_lock_) {
1719 ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
1720 ArtField* resolved_field =
1721 class_linker->LookupResolvedField(field_index, referrer, /* is_static= */ false);
1722 DCHECK(resolved_field != nullptr);
1723 HInstanceFieldGet* iget = new (graph_->GetAllocator()) HInstanceFieldGet(
1724 obj,
1725 resolved_field,
1726 DataType::FromShorty(resolved_field->GetTypeDescriptor()[0]),
1727 resolved_field->GetOffset(),
1728 resolved_field->IsVolatile(),
1729 field_index,
1730 resolved_field->GetDeclaringClass()->GetDexClassDefIndex(),
1731 *referrer->GetDexFile(),
1732 // Read barrier generates a runtime call in slow path and we need a valid
1733 // dex pc for the associated stack map. 0 is bogus but valid. Bug: 26854537.
1734 /* dex_pc= */ 0);
1735 if (iget->GetType() == DataType::Type::kReference) {
1736 // Use the same dex_cache that we used for field lookup as the hint_dex_cache.
1737 Handle<mirror::DexCache> dex_cache =
1738 graph_->GetHandleCache()->NewHandle(referrer->GetDexCache());
1739 ReferenceTypePropagation rtp(graph_,
1740 outer_compilation_unit_.GetClassLoader(),
1741 dex_cache,
1742 /* is_first_run= */ false);
1743 rtp.Visit(iget);
1744 }
1745 return iget;
1746 }
1747
CreateInstanceFieldSet(uint32_t field_index,ArtMethod * referrer,HInstruction * obj,HInstruction * value,bool * is_final)1748 HInstanceFieldSet* HInliner::CreateInstanceFieldSet(uint32_t field_index,
1749 ArtMethod* referrer,
1750 HInstruction* obj,
1751 HInstruction* value,
1752 bool* is_final)
1753 REQUIRES_SHARED(Locks::mutator_lock_) {
1754 ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
1755 ArtField* resolved_field =
1756 class_linker->LookupResolvedField(field_index, referrer, /* is_static= */ false);
1757 DCHECK(resolved_field != nullptr);
1758 if (is_final != nullptr) {
1759 // This information is needed only for constructors.
1760 DCHECK(referrer->IsConstructor());
1761 *is_final = resolved_field->IsFinal();
1762 }
1763 HInstanceFieldSet* iput = new (graph_->GetAllocator()) HInstanceFieldSet(
1764 obj,
1765 value,
1766 resolved_field,
1767 DataType::FromShorty(resolved_field->GetTypeDescriptor()[0]),
1768 resolved_field->GetOffset(),
1769 resolved_field->IsVolatile(),
1770 field_index,
1771 resolved_field->GetDeclaringClass()->GetDexClassDefIndex(),
1772 *referrer->GetDexFile(),
1773 // Read barrier generates a runtime call in slow path and we need a valid
1774 // dex pc for the associated stack map. 0 is bogus but valid. Bug: 26854537.
1775 /* dex_pc= */ 0);
1776 return iput;
1777 }
1778
1779 template <typename T>
NewHandleIfDifferent(ObjPtr<T> object,Handle<T> hint,HGraph * graph)1780 static inline Handle<T> NewHandleIfDifferent(ObjPtr<T> object, Handle<T> hint, HGraph* graph)
1781 REQUIRES_SHARED(Locks::mutator_lock_) {
1782 return (object != hint.Get()) ? graph->GetHandleCache()->NewHandle(object) : hint;
1783 }
1784
CanEncodeInlinedMethodInStackMap(const DexFile & caller_dex_file,ArtMethod * callee)1785 static bool CanEncodeInlinedMethodInStackMap(const DexFile& caller_dex_file, ArtMethod* callee)
1786 REQUIRES_SHARED(Locks::mutator_lock_) {
1787 if (!Runtime::Current()->IsAotCompiler()) {
1788 // JIT can always encode methods in stack maps.
1789 return true;
1790 }
1791 if (IsSameDexFile(caller_dex_file, *callee->GetDexFile())) {
1792 return true;
1793 }
1794 // TODO(ngeoffray): Support more AOT cases for inlining:
1795 // - methods in multidex
1796 // - methods in boot image for on-device non-PIC compilation.
1797 return false;
1798 }
1799
1800 // Substitutes parameters in the callee graph with their values from the caller.
SubstituteArguments(HGraph * callee_graph,HInvoke * invoke_instruction,ReferenceTypeInfo receiver_type,const DexCompilationUnit & dex_compilation_unit)1801 void HInliner::SubstituteArguments(HGraph* callee_graph,
1802 HInvoke* invoke_instruction,
1803 ReferenceTypeInfo receiver_type,
1804 const DexCompilationUnit& dex_compilation_unit) {
1805 ArtMethod* const resolved_method = callee_graph->GetArtMethod();
1806 size_t parameter_index = 0;
1807 bool run_rtp = false;
1808 for (HInstructionIterator instructions(callee_graph->GetEntryBlock()->GetInstructions());
1809 !instructions.Done();
1810 instructions.Advance()) {
1811 HInstruction* current = instructions.Current();
1812 if (current->IsParameterValue()) {
1813 HInstruction* argument = invoke_instruction->InputAt(parameter_index);
1814 if (argument->IsNullConstant()) {
1815 current->ReplaceWith(callee_graph->GetNullConstant());
1816 } else if (argument->IsIntConstant()) {
1817 current->ReplaceWith(callee_graph->GetIntConstant(argument->AsIntConstant()->GetValue()));
1818 } else if (argument->IsLongConstant()) {
1819 current->ReplaceWith(callee_graph->GetLongConstant(argument->AsLongConstant()->GetValue()));
1820 } else if (argument->IsFloatConstant()) {
1821 current->ReplaceWith(
1822 callee_graph->GetFloatConstant(argument->AsFloatConstant()->GetValue()));
1823 } else if (argument->IsDoubleConstant()) {
1824 current->ReplaceWith(
1825 callee_graph->GetDoubleConstant(argument->AsDoubleConstant()->GetValue()));
1826 } else if (argument->GetType() == DataType::Type::kReference) {
1827 if (!resolved_method->IsStatic() && parameter_index == 0 && receiver_type.IsValid()) {
1828 run_rtp = true;
1829 current->SetReferenceTypeInfo(receiver_type);
1830 } else {
1831 current->SetReferenceTypeInfo(argument->GetReferenceTypeInfo());
1832 }
1833 current->AsParameterValue()->SetCanBeNull(argument->CanBeNull());
1834 }
1835 ++parameter_index;
1836 }
1837 }
1838
1839 // We have replaced formal arguments with actual arguments. If actual types
1840 // are more specific than the declared ones, run RTP again on the inner graph.
1841 if (run_rtp || ArgumentTypesMoreSpecific(invoke_instruction, resolved_method)) {
1842 ReferenceTypePropagation(callee_graph,
1843 outer_compilation_unit_.GetClassLoader(),
1844 dex_compilation_unit.GetDexCache(),
1845 /* is_first_run= */ false).Run();
1846 }
1847 }
1848
1849 // Returns whether we can inline the callee_graph into the target_block.
1850 //
1851 // This performs a combination of semantics checks, compiler support checks, and
1852 // resource limit checks.
1853 //
1854 // If this function returns true, it will also set out_number_of_instructions to
1855 // the number of instructions in the inlined body.
CanInlineBody(const HGraph * callee_graph,const HBasicBlock * target_block,size_t * out_number_of_instructions) const1856 bool HInliner::CanInlineBody(const HGraph* callee_graph,
1857 const HBasicBlock* target_block,
1858 size_t* out_number_of_instructions) const {
1859 const DexFile& callee_dex_file = callee_graph->GetDexFile();
1860 ArtMethod* const resolved_method = callee_graph->GetArtMethod();
1861 const uint32_t method_index = resolved_method->GetMethodIndex();
1862 const bool same_dex_file =
1863 IsSameDexFile(*outer_compilation_unit_.GetDexFile(), *resolved_method->GetDexFile());
1864
1865 HBasicBlock* exit_block = callee_graph->GetExitBlock();
1866 if (exit_block == nullptr) {
1867 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedInfiniteLoop)
1868 << "Method " << callee_dex_file.PrettyMethod(method_index)
1869 << " could not be inlined because it has an infinite loop";
1870 return false;
1871 }
1872
1873 bool has_one_return = false;
1874 for (HBasicBlock* predecessor : exit_block->GetPredecessors()) {
1875 if (predecessor->GetLastInstruction()->IsThrow()) {
1876 if (target_block->IsTryBlock()) {
1877 // TODO(ngeoffray): Support adding HTryBoundary in Hgraph::InlineInto.
1878 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedTryCatch)
1879 << "Method " << callee_dex_file.PrettyMethod(method_index)
1880 << " could not be inlined because one branch always throws and"
1881 << " caller is in a try/catch block";
1882 return false;
1883 } else if (graph_->GetExitBlock() == nullptr) {
1884 // TODO(ngeoffray): Support adding HExit in the caller graph.
1885 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedInfiniteLoop)
1886 << "Method " << callee_dex_file.PrettyMethod(method_index)
1887 << " could not be inlined because one branch always throws and"
1888 << " caller does not have an exit block";
1889 return false;
1890 } else if (graph_->HasIrreducibleLoops()) {
1891 // TODO(ngeoffray): Support re-computing loop information to graphs with
1892 // irreducible loops?
1893 VLOG(compiler) << "Method " << callee_dex_file.PrettyMethod(method_index)
1894 << " could not be inlined because one branch always throws and"
1895 << " caller has irreducible loops";
1896 return false;
1897 }
1898 } else {
1899 has_one_return = true;
1900 }
1901 }
1902
1903 if (!has_one_return) {
1904 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedAlwaysThrows)
1905 << "Method " << callee_dex_file.PrettyMethod(method_index)
1906 << " could not be inlined because it always throws";
1907 return false;
1908 }
1909
1910 size_t number_of_instructions = 0;
1911 // Skip the entry block, it does not contain instructions that prevent inlining.
1912 for (HBasicBlock* block : callee_graph->GetReversePostOrderSkipEntryBlock()) {
1913 if (block->IsLoopHeader()) {
1914 if (block->GetLoopInformation()->IsIrreducible()) {
1915 // Don't inline methods with irreducible loops, they could prevent some
1916 // optimizations to run.
1917 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedIrreducibleLoop)
1918 << "Method " << callee_dex_file.PrettyMethod(method_index)
1919 << " could not be inlined because it contains an irreducible loop";
1920 return false;
1921 }
1922 if (!block->GetLoopInformation()->HasExitEdge()) {
1923 // Don't inline methods with loops without exit, since they cause the
1924 // loop information to be computed incorrectly when updating after
1925 // inlining.
1926 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedLoopWithoutExit)
1927 << "Method " << callee_dex_file.PrettyMethod(method_index)
1928 << " could not be inlined because it contains a loop with no exit";
1929 return false;
1930 }
1931 }
1932
1933 for (HInstructionIterator instr_it(block->GetInstructions());
1934 !instr_it.Done();
1935 instr_it.Advance()) {
1936 if (++number_of_instructions >= inlining_budget_) {
1937 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedInstructionBudget)
1938 << "Method " << callee_dex_file.PrettyMethod(method_index)
1939 << " is not inlined because the outer method has reached"
1940 << " its instruction budget limit.";
1941 return false;
1942 }
1943 HInstruction* current = instr_it.Current();
1944 if (current->NeedsEnvironment() &&
1945 (total_number_of_dex_registers_ >= kMaximumNumberOfCumulatedDexRegisters)) {
1946 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedEnvironmentBudget)
1947 << "Method " << callee_dex_file.PrettyMethod(method_index)
1948 << " is not inlined because its caller has reached"
1949 << " its environment budget limit.";
1950 return false;
1951 }
1952
1953 if (current->NeedsEnvironment() &&
1954 !CanEncodeInlinedMethodInStackMap(*caller_compilation_unit_.GetDexFile(),
1955 resolved_method)) {
1956 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedStackMaps)
1957 << "Method " << callee_dex_file.PrettyMethod(method_index)
1958 << " could not be inlined because " << current->DebugName()
1959 << " needs an environment, is in a different dex file"
1960 << ", and cannot be encoded in the stack maps.";
1961 return false;
1962 }
1963
1964 if (!same_dex_file && current->NeedsDexCacheOfDeclaringClass()) {
1965 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedDexCache)
1966 << "Method " << callee_dex_file.PrettyMethod(method_index)
1967 << " could not be inlined because " << current->DebugName()
1968 << " it is in a different dex file and requires access to the dex cache";
1969 return false;
1970 }
1971
1972 if (current->IsUnresolvedStaticFieldGet() ||
1973 current->IsUnresolvedInstanceFieldGet() ||
1974 current->IsUnresolvedStaticFieldSet() ||
1975 current->IsUnresolvedInstanceFieldSet()) {
1976 // Entrypoint for unresolved fields does not handle inlined frames.
1977 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedUnresolvedEntrypoint)
1978 << "Method " << callee_dex_file.PrettyMethod(method_index)
1979 << " could not be inlined because it is using an unresolved"
1980 << " entrypoint";
1981 return false;
1982 }
1983 }
1984 }
1985
1986 *out_number_of_instructions = number_of_instructions;
1987 return true;
1988 }
1989
TryBuildAndInlineHelper(HInvoke * invoke_instruction,ArtMethod * resolved_method,ReferenceTypeInfo receiver_type,HInstruction ** return_replacement)1990 bool HInliner::TryBuildAndInlineHelper(HInvoke* invoke_instruction,
1991 ArtMethod* resolved_method,
1992 ReferenceTypeInfo receiver_type,
1993 HInstruction** return_replacement) {
1994 DCHECK(!(resolved_method->IsStatic() && receiver_type.IsValid()));
1995 const dex::CodeItem* code_item = resolved_method->GetCodeItem();
1996 const DexFile& callee_dex_file = *resolved_method->GetDexFile();
1997 uint32_t method_index = resolved_method->GetDexMethodIndex();
1998 CodeItemDebugInfoAccessor code_item_accessor(resolved_method->DexInstructionDebugInfo());
1999 ClassLinker* class_linker = caller_compilation_unit_.GetClassLinker();
2000 Handle<mirror::DexCache> dex_cache = NewHandleIfDifferent(resolved_method->GetDexCache(),
2001 caller_compilation_unit_.GetDexCache(),
2002 graph_);
2003 Handle<mirror::ClassLoader> class_loader =
2004 NewHandleIfDifferent(resolved_method->GetDeclaringClass()->GetClassLoader(),
2005 caller_compilation_unit_.GetClassLoader(),
2006 graph_);
2007
2008 Handle<mirror::Class> compiling_class =
2009 graph_->GetHandleCache()->NewHandle(resolved_method->GetDeclaringClass());
2010 DexCompilationUnit dex_compilation_unit(
2011 class_loader,
2012 class_linker,
2013 callee_dex_file,
2014 code_item,
2015 resolved_method->GetDeclaringClass()->GetDexClassDefIndex(),
2016 method_index,
2017 resolved_method->GetAccessFlags(),
2018 /* verified_method= */ nullptr,
2019 dex_cache,
2020 compiling_class);
2021
2022 InvokeType invoke_type = invoke_instruction->GetInvokeType();
2023 if (invoke_type == kInterface) {
2024 // We have statically resolved the dispatch. To please the class linker
2025 // at runtime, we change this call as if it was a virtual call.
2026 invoke_type = kVirtual;
2027 }
2028
2029 bool caller_dead_reference_safe = graph_->IsDeadReferenceSafe();
2030 const dex::ClassDef& callee_class = resolved_method->GetClassDef();
2031 // MethodContainsRSensitiveAccess is currently slow, but HasDeadReferenceSafeAnnotation()
2032 // is currently rarely true.
2033 bool callee_dead_reference_safe =
2034 annotations::HasDeadReferenceSafeAnnotation(callee_dex_file, callee_class)
2035 && !annotations::MethodContainsRSensitiveAccess(callee_dex_file, callee_class, method_index);
2036
2037 const int32_t caller_instruction_counter = graph_->GetCurrentInstructionId();
2038 HGraph* callee_graph = new (graph_->GetAllocator()) HGraph(
2039 graph_->GetAllocator(),
2040 graph_->GetArenaStack(),
2041 graph_->GetHandleCache()->GetHandles(),
2042 callee_dex_file,
2043 method_index,
2044 codegen_->GetCompilerOptions().GetInstructionSet(),
2045 invoke_type,
2046 callee_dead_reference_safe,
2047 graph_->IsDebuggable(),
2048 graph_->GetCompilationKind(),
2049 /* start_instruction_id= */ caller_instruction_counter);
2050 callee_graph->SetArtMethod(resolved_method);
2051
2052 // When they are needed, allocate `inline_stats_` on the Arena instead
2053 // of on the stack, as Clang might produce a stack frame too large
2054 // for this function, that would not fit the requirements of the
2055 // `-Wframe-larger-than` option.
2056 if (stats_ != nullptr) {
2057 // Reuse one object for all inline attempts from this caller to keep Arena memory usage low.
2058 if (inline_stats_ == nullptr) {
2059 void* storage = graph_->GetAllocator()->Alloc<OptimizingCompilerStats>(kArenaAllocMisc);
2060 inline_stats_ = new (storage) OptimizingCompilerStats;
2061 } else {
2062 inline_stats_->Reset();
2063 }
2064 }
2065 HGraphBuilder builder(callee_graph,
2066 code_item_accessor,
2067 &dex_compilation_unit,
2068 &outer_compilation_unit_,
2069 codegen_,
2070 inline_stats_,
2071 resolved_method->GetQuickenedInfo());
2072
2073 if (builder.BuildGraph() != kAnalysisSuccess) {
2074 LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedCannotBuild)
2075 << "Method " << callee_dex_file.PrettyMethod(method_index)
2076 << " could not be built, so cannot be inlined";
2077 return false;
2078 }
2079
2080 SubstituteArguments(callee_graph, invoke_instruction, receiver_type, dex_compilation_unit);
2081
2082 RunOptimizations(callee_graph, code_item, dex_compilation_unit);
2083
2084 size_t number_of_instructions = 0;
2085 if (!CanInlineBody(callee_graph, invoke_instruction->GetBlock(), &number_of_instructions)) {
2086 return false;
2087 }
2088
2089 DCHECK_EQ(caller_instruction_counter, graph_->GetCurrentInstructionId())
2090 << "No instructions can be added to the outer graph while inner graph is being built";
2091
2092 // Inline the callee graph inside the caller graph.
2093 const int32_t callee_instruction_counter = callee_graph->GetCurrentInstructionId();
2094 graph_->SetCurrentInstructionId(callee_instruction_counter);
2095 *return_replacement = callee_graph->InlineInto(graph_, invoke_instruction);
2096 // Update our budget for other inlining attempts in `caller_graph`.
2097 total_number_of_instructions_ += number_of_instructions;
2098 UpdateInliningBudget();
2099
2100 DCHECK_EQ(callee_instruction_counter, callee_graph->GetCurrentInstructionId())
2101 << "No instructions can be added to the inner graph during inlining into the outer graph";
2102
2103 if (stats_ != nullptr) {
2104 DCHECK(inline_stats_ != nullptr);
2105 inline_stats_->AddTo(stats_);
2106 }
2107
2108 if (caller_dead_reference_safe && !callee_dead_reference_safe) {
2109 // Caller was dead reference safe, but is not anymore, since we inlined dead
2110 // reference unsafe code. Prior transformations remain valid, since they did not
2111 // affect the inlined code.
2112 graph_->MarkDeadReferenceUnsafe();
2113 }
2114
2115 return true;
2116 }
2117
RunOptimizations(HGraph * callee_graph,const dex::CodeItem * code_item,const DexCompilationUnit & dex_compilation_unit)2118 void HInliner::RunOptimizations(HGraph* callee_graph,
2119 const dex::CodeItem* code_item,
2120 const DexCompilationUnit& dex_compilation_unit) {
2121 // Note: if the outermost_graph_ is being compiled OSR, we should not run any
2122 // optimization that could lead to a HDeoptimize. The following optimizations do not.
2123 HDeadCodeElimination dce(callee_graph, inline_stats_, "dead_code_elimination$inliner");
2124 HConstantFolding fold(callee_graph, "constant_folding$inliner");
2125 InstructionSimplifier simplify(callee_graph, codegen_, inline_stats_);
2126
2127 HOptimization* optimizations[] = {
2128 &simplify,
2129 &fold,
2130 &dce,
2131 };
2132
2133 for (size_t i = 0; i < arraysize(optimizations); ++i) {
2134 HOptimization* optimization = optimizations[i];
2135 optimization->Run();
2136 }
2137
2138 // Bail early for pathological cases on the environment (for example recursive calls,
2139 // or too large environment).
2140 if (total_number_of_dex_registers_ >= kMaximumNumberOfCumulatedDexRegisters) {
2141 LOG_NOTE() << "Calls in " << callee_graph->GetArtMethod()->PrettyMethod()
2142 << " will not be inlined because the outer method has reached"
2143 << " its environment budget limit.";
2144 return;
2145 }
2146
2147 // Bail early if we know we already are over the limit.
2148 size_t number_of_instructions = CountNumberOfInstructions(callee_graph);
2149 if (number_of_instructions > inlining_budget_) {
2150 LOG_NOTE() << "Calls in " << callee_graph->GetArtMethod()->PrettyMethod()
2151 << " will not be inlined because the outer method has reached"
2152 << " its instruction budget limit. " << number_of_instructions;
2153 return;
2154 }
2155
2156 CodeItemDataAccessor accessor(callee_graph->GetDexFile(), code_item);
2157 HInliner inliner(callee_graph,
2158 outermost_graph_,
2159 codegen_,
2160 outer_compilation_unit_,
2161 dex_compilation_unit,
2162 inline_stats_,
2163 total_number_of_dex_registers_ + accessor.RegistersSize(),
2164 total_number_of_instructions_ + number_of_instructions,
2165 this,
2166 depth_ + 1);
2167 inliner.Run();
2168 }
2169
IsReferenceTypeRefinement(ObjPtr<mirror::Class> declared_class,bool declared_is_exact,bool declared_can_be_null,HInstruction * actual_obj)2170 static bool IsReferenceTypeRefinement(ObjPtr<mirror::Class> declared_class,
2171 bool declared_is_exact,
2172 bool declared_can_be_null,
2173 HInstruction* actual_obj)
2174 REQUIRES_SHARED(Locks::mutator_lock_) {
2175 if (declared_can_be_null && !actual_obj->CanBeNull()) {
2176 return true;
2177 }
2178
2179 ReferenceTypeInfo actual_rti = actual_obj->GetReferenceTypeInfo();
2180 ObjPtr<mirror::Class> actual_class = actual_rti.GetTypeHandle().Get();
2181 return (actual_rti.IsExact() && !declared_is_exact) ||
2182 (declared_class != actual_class && declared_class->IsAssignableFrom(actual_class));
2183 }
2184
IsReferenceTypeRefinement(ObjPtr<mirror::Class> declared_class,bool declared_can_be_null,HInstruction * actual_obj)2185 static bool IsReferenceTypeRefinement(ObjPtr<mirror::Class> declared_class,
2186 bool declared_can_be_null,
2187 HInstruction* actual_obj)
2188 REQUIRES_SHARED(Locks::mutator_lock_) {
2189 bool admissible = ReferenceTypePropagation::IsAdmissible(declared_class);
2190 return IsReferenceTypeRefinement(
2191 admissible ? declared_class : GetClassRoot<mirror::Class>(),
2192 /*declared_is_exact=*/ admissible && declared_class->CannotBeAssignedFromOtherTypes(),
2193 declared_can_be_null,
2194 actual_obj);
2195 }
2196
ArgumentTypesMoreSpecific(HInvoke * invoke_instruction,ArtMethod * resolved_method)2197 bool HInliner::ArgumentTypesMoreSpecific(HInvoke* invoke_instruction, ArtMethod* resolved_method) {
2198 // If this is an instance call, test whether the type of the `this` argument
2199 // is more specific than the class which declares the method.
2200 if (!resolved_method->IsStatic()) {
2201 if (IsReferenceTypeRefinement(resolved_method->GetDeclaringClass(),
2202 /*declared_can_be_null=*/ false,
2203 invoke_instruction->InputAt(0u))) {
2204 return true;
2205 }
2206 }
2207
2208 // Iterate over the list of parameter types and test whether any of the
2209 // actual inputs has a more specific reference type than the type declared in
2210 // the signature.
2211 const dex::TypeList* param_list = resolved_method->GetParameterTypeList();
2212 for (size_t param_idx = 0,
2213 input_idx = resolved_method->IsStatic() ? 0 : 1,
2214 e = (param_list == nullptr ? 0 : param_list->Size());
2215 param_idx < e;
2216 ++param_idx, ++input_idx) {
2217 HInstruction* input = invoke_instruction->InputAt(input_idx);
2218 if (input->GetType() == DataType::Type::kReference) {
2219 ObjPtr<mirror::Class> param_cls = resolved_method->LookupResolvedClassFromTypeIndex(
2220 param_list->GetTypeItem(param_idx).type_idx_);
2221 if (IsReferenceTypeRefinement(param_cls, /*declared_can_be_null=*/ true, input)) {
2222 return true;
2223 }
2224 }
2225 }
2226
2227 return false;
2228 }
2229
ReturnTypeMoreSpecific(HInvoke * invoke_instruction,HInstruction * return_replacement)2230 bool HInliner::ReturnTypeMoreSpecific(HInvoke* invoke_instruction,
2231 HInstruction* return_replacement) {
2232 // Check the integrity of reference types and run another type propagation if needed.
2233 if (return_replacement != nullptr) {
2234 if (return_replacement->GetType() == DataType::Type::kReference) {
2235 // Test if the return type is a refinement of the declared return type.
2236 ReferenceTypeInfo invoke_rti = invoke_instruction->GetReferenceTypeInfo();
2237 if (IsReferenceTypeRefinement(invoke_rti.GetTypeHandle().Get(),
2238 invoke_rti.IsExact(),
2239 /*declared_can_be_null=*/ true,
2240 return_replacement)) {
2241 return true;
2242 } else if (return_replacement->IsInstanceFieldGet()) {
2243 HInstanceFieldGet* field_get = return_replacement->AsInstanceFieldGet();
2244 if (field_get->GetFieldInfo().GetField() ==
2245 GetClassRoot<mirror::Object>()->GetInstanceField(0)) {
2246 return true;
2247 }
2248 }
2249 } else if (return_replacement->IsInstanceOf()) {
2250 // Inlining InstanceOf into an If may put a tighter bound on reference types.
2251 return true;
2252 }
2253 }
2254
2255 return false;
2256 }
2257
FixUpReturnReferenceType(ArtMethod * resolved_method,HInstruction * return_replacement)2258 void HInliner::FixUpReturnReferenceType(ArtMethod* resolved_method,
2259 HInstruction* return_replacement) {
2260 if (return_replacement != nullptr) {
2261 if (return_replacement->GetType() == DataType::Type::kReference) {
2262 if (!return_replacement->GetReferenceTypeInfo().IsValid()) {
2263 // Make sure that we have a valid type for the return. We may get an invalid one when
2264 // we inline invokes with multiple branches and create a Phi for the result.
2265 // TODO: we could be more precise by merging the phi inputs but that requires
2266 // some functionality from the reference type propagation.
2267 DCHECK(return_replacement->IsPhi());
2268 ObjPtr<mirror::Class> cls = resolved_method->LookupResolvedReturnType();
2269 ReferenceTypeInfo rti = ReferenceTypePropagation::IsAdmissible(cls)
2270 ? ReferenceTypeInfo::Create(graph_->GetHandleCache()->NewHandle(cls))
2271 : graph_->GetInexactObjectRti();
2272 return_replacement->SetReferenceTypeInfo(rti);
2273 }
2274 }
2275 }
2276 }
2277
2278 } // namespace art
2279