1 /*
2 * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotLinkedClassBulkLoader.hpp"
26 #include "code/scopeDesc.hpp"
27 #include "compiler/compilationPolicy.hpp"
28 #include "compiler/compileBroker.hpp"
29 #include "compiler/compilerDefinitions.inline.hpp"
30 #include "compiler/compilerOracle.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/method.inline.hpp"
33 #include "oops/methodData.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/trainingData.hpp"
36 #include "prims/jvmtiExport.hpp"
37 #include "runtime/arguments.hpp"
38 #include "runtime/deoptimization.hpp"
39 #include "runtime/frame.hpp"
40 #include "runtime/frame.inline.hpp"
41 #include "runtime/globals_extension.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/safepoint.hpp"
44 #include "runtime/safepointVerifiers.hpp"
45 #ifdef COMPILER1
46 #include "c1/c1_Compiler.hpp"
47 #endif
48 #ifdef COMPILER2
49 #include "opto/c2compiler.hpp"
50 #endif
51 #if INCLUDE_JVMCI
52 #include "jvmci/jvmci.hpp"
53 #endif
54
55 int64_t CompilationPolicy::_start_time = 0;
56 int CompilationPolicy::_c1_count = 0;
57 int CompilationPolicy::_c2_count = 0;
58 double CompilationPolicy::_increase_threshold_at_ratio = 0;
59
60 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
61
62 void compilationPolicy_init() {
63 CompilationPolicy::initialize();
64 }
65
66 int CompilationPolicy::compiler_count(CompLevel comp_level) {
67 if (is_c1_compile(comp_level)) {
68 return c1_count();
69 } else if (is_c2_compile(comp_level)) {
70 return c2_count();
71 }
72 return 0;
73 }
74
75 // Returns true if m must be compiled before executing it
76 // This is intended to force compiles for methods (usually for
77 // debugging) that would otherwise be interpreted for some reason.
78 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
79 // Don't allow Xcomp to cause compiles in replay mode
80 if (ReplayCompiles) return false;
81
82 if (m->has_compiled_code()) return false; // already compiled
83 if (!can_be_compiled(m, comp_level)) return false;
84
85 return !UseInterpreter || // must compile all methods
86 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
87 }
88
89 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
90 if (m->method_holder()->is_not_initialized()) {
91 // 'is_not_initialized' means not only '!is_initialized', but also that
92 // initialization has not been started yet ('!being_initialized')
93 // Do not force compilation of methods in uninitialized classes.
94 return;
95 }
96 if (!m->is_native() && MethodTrainingData::have_data()) {
97 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
98 if (mtd == nullptr) {
99 return; // there is no training data recorded for m
100 }
101 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
102 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
103 if (next_level != cur_level && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
104 if (PrintTieredEvents) {
105 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
106 }
107 CompileBroker::compile_method(m, InvocationEntryBci, next_level, 0, CompileTask::Reason_MustBeCompiled, THREAD);
108 if (HAS_PENDING_EXCEPTION) {
109 CLEAR_PENDING_EXCEPTION;
110 }
111 }
112 }
113 }
114
115 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
116 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
117 // don't force compilation, resolve was on behalf of compiler
118 return;
119 }
120 if (m->method_holder()->is_not_initialized()) {
121 // 'is_not_initialized' means not only '!is_initialized', but also that
122 // initialization has not been started yet ('!being_initialized')
123 // Do not force compilation of methods in uninitialized classes.
124 // Note that doing this would throw an assert later,
125 // in CompileBroker::compile_method.
126 // We sometimes use the link resolver to do reflective lookups
127 // even before classes are initialized.
128 return;
129 }
130
131 if (must_be_compiled(m)) {
132 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
133 CompLevel level = initial_compile_level(m);
134 if (PrintTieredEvents) {
135 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
136 }
137 CompileBroker::compile_method(m, InvocationEntryBci, level, 0, CompileTask::Reason_MustBeCompiled, THREAD);
138 }
139 }
140
141 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, JavaThread* current) {
142 if (!klass->has_init_deps_processed()) {
143 ResourceMark rm;
144 log_debug(training)("Replay training: %s", klass->external_name());
145
146 KlassTrainingData* ktd = KlassTrainingData::find(klass);
147 if (ktd != nullptr) {
148 guarantee(ktd->has_holder(), "");
149 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
150 assert(klass->has_init_deps_processed(), "");
151 if (AOTCompileEagerly) {
152 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
153 if (ctd->init_deps_left_acquire() == 0) {
154 MethodTrainingData* mtd = ctd->method();
155 if (mtd->has_holder()) {
156 const methodHandle mh(current, const_cast<Method*>(mtd->holder()));
157 CompilationPolicy::maybe_compile_early(mh, current);
158 }
159 }
160 });
161 }
162 }
163 }
164 }
165
166 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, JavaThread* current) {
167 assert(klass->is_initialized(), "");
168 if (TrainingData::have_data() && klass->in_aot_cache()) {
169 _training_replay_queue.push(klass, TrainingReplayQueue_lock, current);
170 }
171 }
172
173 // For TrainingReplayQueue
174 template<>
175 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
176 int pos = 0;
177 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
178 ResourceMark rm;
179 InstanceKlass* ik = cur->value();
180 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
181 }
182 }
183
184 void CompilationPolicy::replay_training_at_init_loop(JavaThread* current) {
185 while (!CompileBroker::is_compilation_disabled_forever()) {
186 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, current);
187 if (ik != nullptr) {
188 replay_training_at_init_impl(ik, current);
189 }
190 }
191 }
192
193 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
194 if (comp_level == CompLevel_any) {
195 if (CompilerConfig::is_c1_only()) {
196 comp_level = CompLevel_simple;
197 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
198 comp_level = CompLevel_full_optimization;
199 }
200 }
201 return comp_level;
202 }
203
204 // Returns true if m is allowed to be compiled
205 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
206 // allow any levels for WhiteBox
207 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
208
209 if (m->is_abstract()) return false;
210 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
211
212 // Math intrinsics should never be compiled as this can lead to
213 // monotonicity problems because the interpreter will prefer the
214 // compiled code to the intrinsic version. This can't happen in
215 // production because the invocation counter can't be incremented
216 // but we shouldn't expose the system to this problem in testing
217 // modes.
218 if (!AbstractInterpreter::can_be_compiled(m)) {
219 return false;
220 }
221 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
222 if (comp_level == CompLevel_any || is_compile(comp_level)) {
223 return !m->is_not_compilable(comp_level);
224 }
225 return false;
226 }
227
228 // Returns true if m is allowed to be osr compiled
229 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
230 bool result = false;
231 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
232 if (comp_level == CompLevel_any || is_compile(comp_level)) {
233 result = !m->is_not_osr_compilable(comp_level);
234 }
235 return (result && can_be_compiled(m, comp_level));
236 }
237
238 bool CompilationPolicy::is_compilation_enabled() {
239 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
240 return CompileBroker::should_compile_new_jobs();
241 }
242
243 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
244 // Remove unloaded methods from the queue
245 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
246 CompileTask* next = task->next();
247 if (task->is_unloaded()) {
248 compile_queue->remove_and_mark_stale(task);
249 }
250 task = next;
251 }
252 #if INCLUDE_JVMCI
253 if (UseJVMCICompiler && !BackgroundCompilation) {
254 /*
255 * In blocking compilation mode, the CompileBroker will make
256 * compilations submitted by a JVMCI compiler thread non-blocking. These
257 * compilations should be scheduled after all blocking compilations
258 * to service non-compiler related compilations sooner and reduce the
259 * chance of such compilations timing out.
260 */
261 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
262 if (task->is_blocking()) {
263 return task;
264 }
265 }
266 }
267 #endif
268 return compile_queue->first();
269 }
270
271 // Simple methods are as good being compiled with C1 as C2.
272 // Determine if a given method is such a case.
273 bool CompilationPolicy::is_trivial(const methodHandle& method) {
274 if (method->is_accessor() ||
275 method->is_constant_getter()) {
276 return true;
277 }
278 return false;
279 }
280
281 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
282 if (CompilationModeFlag::quick_internal()) {
283 #if INCLUDE_JVMCI
284 if (UseJVMCICompiler) {
285 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
286 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
287 return true;
288 }
289 }
290 #endif
291 }
292 return false;
293 }
294
295 CompLevel CompilationPolicy::comp_level(Method* method) {
296 nmethod *nm = method->code();
297 if (nm != nullptr && nm->is_in_use()) {
298 return (CompLevel)nm->comp_level();
299 }
300 return CompLevel_none;
301 }
302
303 // Call and loop predicates determine whether a transition to a higher
304 // compilation level should be performed (pointers to predicate functions
305 // are passed to common()).
306 // Tier?LoadFeedback is basically a coefficient that determines of
307 // how many methods per compiler thread can be in the queue before
308 // the threshold values double.
309 class LoopPredicate : AllStatic {
310 public:
311 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
312 double threshold_scaling;
313 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
314 scale *= threshold_scaling;
315 }
316 switch(cur_level) {
317 case CompLevel_none:
318 case CompLevel_limited_profile:
319 return b >= Tier3BackEdgeThreshold * scale;
320 case CompLevel_full_profile:
321 return b >= Tier4BackEdgeThreshold * scale;
322 default:
323 return true;
324 }
325 }
326
327 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
328 double k = 1;
329 switch(cur_level) {
330 case CompLevel_none:
331 // Fall through
332 case CompLevel_limited_profile: {
333 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
334 break;
335 }
336 case CompLevel_full_profile: {
337 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
338 break;
339 }
340 default:
341 return true;
342 }
343 return apply_scaled(method, cur_level, i, b, k);
344 }
345 };
346
347 class CallPredicate : AllStatic {
348 public:
349 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
350 double threshold_scaling;
351 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
352 scale *= threshold_scaling;
353 }
354 switch(cur_level) {
355 case CompLevel_none:
356 case CompLevel_limited_profile:
357 return (i >= Tier3InvocationThreshold * scale) ||
358 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
359 case CompLevel_full_profile:
360 return (i >= Tier4InvocationThreshold * scale) ||
361 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
362 default:
363 return true;
364 }
365 }
366
367 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
368 double k = 1;
369 switch(cur_level) {
370 case CompLevel_none:
371 case CompLevel_limited_profile: {
372 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
373 break;
374 }
375 case CompLevel_full_profile: {
376 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
377 break;
378 }
379 default:
380 return true;
381 }
382 return apply_scaled(method, cur_level, i, b, k);
383 }
384 };
385
386 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
387 int comp_count = compiler_count(level);
388 if (comp_count > 0 && feedback_k > 0) {
389 double queue_size = CompileBroker::queue_size(level);
390 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
391
392 // Increase C1 compile threshold when the code cache is filled more
393 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
394 // The main intention is to keep enough free space for C2 compiled code
395 // to achieve peak performance if the code cache is under stress.
396 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
397 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
398 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
399 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
400 }
401 }
402 return k;
403 }
404 return 1;
405 }
406
407 void CompilationPolicy::print_counters_on(outputStream* st, const char* prefix, Method* m) {
408 int invocation_count = m->invocation_count();
409 int backedge_count = m->backedge_count();
410 MethodData* mdh = m->method_data();
411 int mdo_invocations = 0, mdo_backedges = 0;
412 int mdo_invocations_start = 0, mdo_backedges_start = 0;
413 if (mdh != nullptr) {
414 mdo_invocations = mdh->invocation_count();
415 mdo_backedges = mdh->backedge_count();
416 mdo_invocations_start = mdh->invocation_count_start();
417 mdo_backedges_start = mdh->backedge_count_start();
418 }
419 st->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
420 invocation_count, backedge_count, prefix,
421 mdo_invocations, mdo_invocations_start,
422 mdo_backedges, mdo_backedges_start);
423 st->print(" %smax levels=%d,%d", prefix, m->highest_comp_level(), m->highest_osr_comp_level());
424 }
425
426 void CompilationPolicy::print_training_data_on(outputStream* st, const char* prefix, Method* method, CompLevel cur_level) {
427 methodHandle m(Thread::current(), method);
428 st->print(" %smtd: ", prefix);
429 MethodTrainingData* mtd = MethodTrainingData::find(m);
430 if (mtd == nullptr) {
431 st->print("null");
432 } else {
433 if (should_delay_standard_transition(m, cur_level, mtd)) {
434 st->print("delayed, ");
435 }
436 MethodData* md = mtd->final_profile();
437 st->print("mdo=");
438 if (md == nullptr) {
439 st->print("null");
440 } else {
441 int mdo_invocations = md->invocation_count();
442 int mdo_backedges = md->backedge_count();
443 int mdo_invocations_start = md->invocation_count_start();
444 int mdo_backedges_start = md->backedge_count_start();
445 st->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
446 }
447 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
448 st->print(", deps=");
449 if (ctd == nullptr) {
450 st->print("null");
451 } else {
452 st->print("%d", ctd->init_deps_left_acquire());
453 }
454 }
455 }
456
457 // Print an event.
458 void CompilationPolicy::print_event_on(outputStream *st, EventType type, Method* m, Method* im, int bci, CompLevel level) {
459 bool inlinee_event = m != im;
460
461 st->print("%lf: [", os::elapsedTime());
462
463 switch(type) {
464 case CALL:
465 st->print("call");
466 break;
467 case LOOP:
468 st->print("loop");
469 break;
470 case COMPILE:
471 st->print("compile");
472 break;
473 case FORCE_COMPILE:
474 st->print("force-compile");
475 break;
476 case REMOVE_FROM_QUEUE:
477 st->print("remove-from-queue");
478 break;
479 case UPDATE_IN_QUEUE:
480 st->print("update-in-queue");
481 break;
482 case REPROFILE:
483 st->print("reprofile");
484 break;
485 case MAKE_NOT_ENTRANT:
486 st->print("make-not-entrant");
487 break;
488 default:
489 st->print("unknown");
490 }
491
492 st->print(" level=%d ", level);
493
494 ResourceMark rm;
495 char *method_name = m->name_and_sig_as_C_string();
496 st->print("[%s", method_name);
497 if (inlinee_event) {
498 char *inlinee_name = im->name_and_sig_as_C_string();
499 st->print(" [%s]] ", inlinee_name);
500 }
501 else st->print("] ");
502 st->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
503 CompileBroker::queue_size(CompLevel_full_optimization));
504
505 st->print(" rate=");
506 if (m->prev_time() == 0) st->print("n/a");
507 else st->print("%f", m->rate());
508
509 st->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
510 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
511
512 if (type != COMPILE) {
513 print_counters_on(st, "", m);
514 if (inlinee_event) {
515 print_counters_on(st, "inlinee ", im);
516 }
517 st->print(" compilable=");
518 bool need_comma = false;
519 if (!m->is_not_compilable(CompLevel_full_profile)) {
520 st->print("c1");
521 need_comma = true;
522 }
523 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
524 if (need_comma) st->print(",");
525 st->print("c1-osr");
526 need_comma = true;
527 }
528 if (!m->is_not_compilable(CompLevel_full_optimization)) {
529 if (need_comma) st->print(",");
530 st->print("c2");
531 need_comma = true;
532 }
533 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
534 if (need_comma) st->print(",");
535 st->print("c2-osr");
536 }
537 st->print(" status=");
538 if (m->queued_for_compilation()) {
539 st->print("in-queue");
540 } else st->print("idle");
541
542 print_training_data_on(st, "", m, level);
543 if (inlinee_event) {
544 print_training_data_on(st, "inlinee ", im, level);
545 }
546 }
547 st->print_cr("]");
548
549 }
550
551 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
552 stringStream s;
553 print_event_on(&s, type, m, im, bci, level);
554 ResourceMark rm;
555 tty->print("%s", s.as_string());
556 }
557
558 void CompilationPolicy::initialize() {
559 if (!CompilerConfig::is_interpreter_only()) {
560 int count = CICompilerCount;
561 bool c1_only = CompilerConfig::is_c1_only();
562 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
563 int min_count = (c1_only || c2_only) ? 1 : 2;
564
565 #ifdef _LP64
566 // Turn on ergonomic compiler count selection
567 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
568 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
569 }
570 if (CICompilerCountPerCPU) {
571 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
572 int log_cpu = log2i(os::active_processor_count());
573 int loglog_cpu = log2i(MAX2(log_cpu, 1));
574 count = MAX2(log_cpu * loglog_cpu * 3 / 2, min_count);
575 // Make sure there is enough space in the code cache to hold all the compiler buffers
576 size_t c1_size = 0;
577 #ifdef COMPILER1
578 c1_size = Compiler::code_buffer_size();
579 #endif
580 size_t c2_size = 0;
581 #ifdef COMPILER2
582 c2_size = C2Compiler::initial_code_buffer_size();
583 #endif
584 size_t buffer_size = 0;
585 if (c1_only) {
586 buffer_size = c1_size;
587 } else if (c2_only) {
588 buffer_size = c2_size;
589 } else {
590 buffer_size = c1_size / 3 + 2 * c2_size / 3;
591 }
592 size_t max_count = (NonNMethodCodeHeapSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / buffer_size;
593 if ((size_t)count > max_count) {
594 // Lower the compiler count such that all buffers fit into the code cache
595 count = MAX2((int)max_count, min_count);
596 }
597 FLAG_SET_ERGO(CICompilerCount, count);
598 }
599 #else
600 // On 32-bit systems, the number of compiler threads is limited to 3.
601 // On these systems, the virtual address space available to the JVM
602 // is usually limited to 2-4 GB (the exact value depends on the platform).
603 // As the compilers (especially C2) can consume a large amount of
604 // memory, scaling the number of compiler threads with the number of
605 // available cores can result in the exhaustion of the address space
606 /// available to the VM and thus cause the VM to crash.
607 if (FLAG_IS_DEFAULT(CICompilerCount)) {
608 count = 3;
609 FLAG_SET_ERGO(CICompilerCount, count);
610 }
611 #endif // _LP64
612
613 if (c1_only) {
614 // No C2 compiler threads are needed
615 set_c1_count(count);
616 } else if (c2_only) {
617 // No C1 compiler threads are needed
618 set_c2_count(count);
619 } else {
620 #if INCLUDE_JVMCI
621 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
622 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
623 int c1_count = MAX2(count - libjvmci_count, 1);
624 set_c2_count(libjvmci_count);
625 set_c1_count(c1_count);
626 } else
627 #endif
628 {
629 set_c1_count(MAX2(count / 3, 1));
630 set_c2_count(MAX2(count - c1_count(), 1));
631 }
632 }
633 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
634 set_increase_threshold_at_ratio();
635 } else {
636 // Interpreter mode creates no compilers
637 FLAG_SET_ERGO(CICompilerCount, 0);
638 }
639 set_start_time(nanos_to_millis(os::javaTimeNanos()));
640 }
641
642
643 #ifdef ASSERT
644 bool CompilationPolicy::verify_level(CompLevel level) {
645 if (TieredCompilation && level > TieredStopAtLevel) {
646 return false;
647 }
648 // Check if there is a compiler to process the requested level
649 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
650 return false;
651 }
652 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
653 return false;
654 }
655
656 // Interpreter level is always valid.
657 if (level == CompLevel_none) {
658 return true;
659 }
660 if (CompilationModeFlag::normal()) {
661 return true;
662 } else if (CompilationModeFlag::quick_only()) {
663 return level == CompLevel_simple;
664 } else if (CompilationModeFlag::high_only()) {
665 return level == CompLevel_full_optimization;
666 } else if (CompilationModeFlag::high_only_quick_internal()) {
667 return level == CompLevel_full_optimization || level == CompLevel_simple;
668 }
669 return false;
670 }
671 #endif
672
673
674 CompLevel CompilationPolicy::highest_compile_level() {
675 CompLevel level = CompLevel_none;
676 // Setup the maximum level available for the current compiler configuration.
677 if (!CompilerConfig::is_interpreter_only()) {
678 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
679 level = CompLevel_full_optimization;
680 } else if (CompilerConfig::is_c1_enabled()) {
681 if (CompilerConfig::is_c1_simple_only()) {
682 level = CompLevel_simple;
683 } else {
684 level = CompLevel_full_profile;
685 }
686 }
687 }
688 // Clamp the maximum level with TieredStopAtLevel.
689 if (TieredCompilation) {
690 level = MIN2(level, (CompLevel) TieredStopAtLevel);
691 }
692
693 // Fix it up if after the clamping it has become invalid.
694 // Bring it monotonically down depending on the next available level for
695 // the compilation mode.
696 if (!CompilationModeFlag::normal()) {
697 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
698 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
699 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
700 if (CompilationModeFlag::quick_only()) {
701 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
702 level = CompLevel_simple;
703 }
704 } else if (CompilationModeFlag::high_only()) {
705 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
706 level = CompLevel_none;
707 }
708 } else if (CompilationModeFlag::high_only_quick_internal()) {
709 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
710 level = CompLevel_simple;
711 }
712 }
713 }
714
715 assert(verify_level(level), "Invalid highest compilation level: %d", level);
716 return level;
717 }
718
719 CompLevel CompilationPolicy::limit_level(CompLevel level) {
720 level = MIN2(level, highest_compile_level());
721 assert(verify_level(level), "Invalid compilation level: %d", level);
722 return level;
723 }
724
725 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
726 CompLevel level = CompLevel_any;
727 if (CompilationModeFlag::normal()) {
728 level = CompLevel_full_profile;
729 } else if (CompilationModeFlag::quick_only()) {
730 level = CompLevel_simple;
731 } else if (CompilationModeFlag::high_only()) {
732 level = CompLevel_full_optimization;
733 } else if (CompilationModeFlag::high_only_quick_internal()) {
734 if (force_comp_at_level_simple(method)) {
735 level = CompLevel_simple;
736 } else {
737 level = CompLevel_full_optimization;
738 }
739 }
740 assert(level != CompLevel_any, "Unhandled compilation mode");
741 return limit_level(level);
742 }
743
744 // Set carry flags on the counters if necessary
745 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
746 MethodCounters *mcs = method->method_counters();
747 if (mcs != nullptr) {
748 mcs->invocation_counter()->set_carry_on_overflow();
749 mcs->backedge_counter()->set_carry_on_overflow();
750 }
751 MethodData* mdo = method->method_data();
752 if (mdo != nullptr) {
753 mdo->invocation_counter()->set_carry_on_overflow();
754 mdo->backedge_counter()->set_carry_on_overflow();
755 }
756 }
757
758 // Called with the queue locked and with at least one element
759 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
760 CompileTask *max_blocking_task = nullptr;
761 CompileTask *max_task = nullptr;
762 Method* max_method = nullptr;
763
764 int64_t t = nanos_to_millis(os::javaTimeNanos());
765 // Iterate through the queue and find a method with a maximum rate.
766 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
767 CompileTask* next_task = task->next();
768 // If a method was unloaded or has been stale for some time, remove it from the queue.
769 // Blocking tasks and tasks submitted from whitebox API don't become stale
770 if (task->is_unloaded()) {
771 compile_queue->remove_and_mark_stale(task);
772 task = next_task;
773 continue;
774 }
775 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
776 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
777 // selection and/or any level adjustments. Just return them in order.
778 return task;
779 }
780 Method* method = task->method();
781 methodHandle mh(THREAD, method);
782 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
783 if (PrintTieredEvents) {
784 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
785 }
786 method->clear_queued_for_compilation();
787 compile_queue->remove_and_mark_stale(task);
788 task = next_task;
789 continue;
790 }
791 update_rate(t, mh);
792 if (max_task == nullptr || compare_methods(method, max_method)) {
793 // Select a method with the highest rate
794 max_task = task;
795 max_method = method;
796 }
797
798 if (task->is_blocking()) {
799 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
800 max_blocking_task = task;
801 }
802 }
803
804 task = next_task;
805 }
806
807 if (max_blocking_task != nullptr) {
808 // In blocking compilation mode, the CompileBroker will make
809 // compilations submitted by a JVMCI compiler thread non-blocking. These
810 // compilations should be scheduled after all blocking compilations
811 // to service non-compiler related compilations sooner and reduce the
812 // chance of such compilations timing out.
813 max_task = max_blocking_task;
814 max_method = max_task->method();
815 }
816
817 methodHandle max_method_h(THREAD, max_method);
818
819 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
820 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
821 max_task->set_comp_level(CompLevel_limited_profile);
822
823 if (CompileBroker::compilation_is_complete(max_method_h, max_task->osr_bci(), CompLevel_limited_profile)) {
824 if (PrintTieredEvents) {
825 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
826 }
827 compile_queue->remove_and_mark_stale(max_task);
828 max_method->clear_queued_for_compilation();
829 return nullptr;
830 }
831
832 if (PrintTieredEvents) {
833 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
834 }
835 }
836 return max_task;
837 }
838
839 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
840 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
841 if (PrintTieredEvents) {
842 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
843 }
844 MethodData* mdo = sd->method()->method_data();
845 if (mdo != nullptr) {
846 mdo->reset_start_counters();
847 }
848 if (sd->is_top()) break;
849 }
850 }
851
852 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
853 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
854 if (PrintTieredEvents) {
855 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
856 }
857
858 if (comp_level == CompLevel_none &&
859 JvmtiExport::can_post_interpreter_events() &&
860 THREAD->is_interp_only_mode()) {
861 return nullptr;
862 }
863 if (ReplayCompiles) {
864 // Don't trigger other compiles in testing mode
865 return nullptr;
866 }
867
868 handle_counter_overflow(method);
869 if (method() != inlinee()) {
870 handle_counter_overflow(inlinee);
871 }
872
873 if (bci == InvocationEntryBci) {
874 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
875 } else {
876 // method == inlinee if the event originated in the main method
877 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
878 // Check if event led to a higher level OSR compilation
879 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
880 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
881 // It's not possible to reach the expected level so fall back to simple.
882 expected_comp_level = CompLevel_simple;
883 }
884 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
885 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
886 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
887 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
888 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
889 // Perform OSR with new nmethod
890 return osr_nm;
891 }
892 }
893 }
894 return nullptr;
895 }
896
897 // Check if the method can be compiled, change level if necessary
898 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
899 assert(verify_level(level), "Invalid compilation level requested: %d", level);
900
901 if (level == CompLevel_none) {
902 if (mh->has_compiled_code()) {
903 // Happens when we switch to interpreter to profile.
904 MutexLocker ml(Compile_lock);
905 NoSafepointVerifier nsv;
906 if (mh->has_compiled_code()) {
907 mh->code()->make_not_used();
908 }
909 // Deoptimize immediately (we don't have to wait for a compile).
910 JavaThread* jt = THREAD;
911 RegisterMap map(jt,
912 RegisterMap::UpdateMap::skip,
913 RegisterMap::ProcessFrames::include,
914 RegisterMap::WalkContinuation::skip);
915 frame fr = jt->last_frame().sender(&map);
916 Deoptimization::deoptimize_frame(jt, fr.id());
917 }
918 return;
919 }
920
921 // Check if the method can be compiled. Additional logic for TieredCompilation:
922 // If it cannot be compiled with C1, continue profiling in the interpreter
923 // and then compile with C2 (the transition function will request that,
924 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
925 // pure C1.
926 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
927 if (!CompilationModeFlag::disable_intermediate() &&
928 level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
929 compile(mh, bci, CompLevel_simple, THREAD);
930 }
931 return;
932 }
933 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
934 if (!CompilationModeFlag::disable_intermediate() &&
935 level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
936 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
937 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
938 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
939 osr_nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_FOR_COMPILING_WITH_C1);
940 }
941 compile(mh, bci, CompLevel_simple, THREAD);
942 }
943 return;
944 }
945 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
946 return;
947 }
948 if (!CompileBroker::compilation_is_in_queue(mh)) {
949 if (PrintTieredEvents) {
950 print_event(COMPILE, mh(), mh(), bci, level);
951 }
952 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
953 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
954 CompileBroker::compile_method(mh, bci, level, hot_count, CompileTask::Reason_Tiered, THREAD);
955 }
956 }
957
958 // update_rate() is called from select_task() while holding a compile queue lock.
959 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
960 // Skip update if counters are absent.
961 // Can't allocate them since we are holding compile queue lock.
962 if (method->method_counters() == nullptr) return;
963
964 if (is_old(method)) {
965 // We don't remove old methods from the queue,
966 // so we can just zero the rate.
967 method->set_rate(0);
968 return;
969 }
970
971 // We don't update the rate if we've just came out of a safepoint.
972 // delta_s is the time since last safepoint in milliseconds.
973 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
974 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
975 // How many events were there since the last time?
976 int event_count = method->invocation_count() + method->backedge_count();
977 int delta_e = event_count - method->prev_event_count();
978
979 // We should be running for at least 1ms.
980 if (delta_s >= TieredRateUpdateMinTime) {
981 // And we must've taken the previous point at least 1ms before.
982 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
983 method->set_prev_time(t);
984 method->set_prev_event_count(event_count);
985 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
986 } else {
987 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
988 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
989 method->set_rate(0);
990 }
991 }
992 }
993 }
994
995 // Check if this method has been stale for a given number of milliseconds.
996 // See select_task().
997 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
998 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
999 int64_t delta_t = t - method->prev_time();
1000 if (delta_t > timeout && delta_s > timeout) {
1001 int event_count = method->invocation_count() + method->backedge_count();
1002 int delta_e = event_count - method->prev_event_count();
1003 // Return true if there were no events.
1004 return delta_e == 0;
1005 }
1006 return false;
1007 }
1008
1009 // We don't remove old methods from the compile queue even if they have
1010 // very low activity. See select_task().
1011 bool CompilationPolicy::is_old(const methodHandle& method) {
1012 int i = method->invocation_count();
1013 int b = method->backedge_count();
1014 double k = TieredOldPercentage / 100.0;
1015
1016 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1017 }
1018
1019 double CompilationPolicy::weight(Method* method) {
1020 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1021 }
1022
1023 // Apply heuristics and return true if x should be compiled before y
1024 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1025 if (x->highest_comp_level() > y->highest_comp_level()) {
1026 // recompilation after deopt
1027 return true;
1028 } else
1029 if (x->highest_comp_level() == y->highest_comp_level()) {
1030 if (weight(x) > weight(y)) {
1031 return true;
1032 }
1033 }
1034 return false;
1035 }
1036
1037 // Is method profiled enough?
1038 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1039 MethodData* mdo = method->method_data();
1040 if (mdo != nullptr) {
1041 int i = mdo->invocation_count_delta();
1042 int b = mdo->backedge_count_delta();
1043 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1044 }
1045 return false;
1046 }
1047
1048
1049 // Determine is a method is mature.
1050 bool CompilationPolicy::is_mature(MethodData* mdo) {
1051 if (Arguments::is_compiler_only()) {
1052 // Always report profiles as immature with -Xcomp
1053 return false;
1054 }
1055 methodHandle mh(Thread::current(), mdo->method());
1056 if (mdo != nullptr) {
1057 int i = mdo->invocation_count();
1058 int b = mdo->backedge_count();
1059 double k = ProfileMaturityPercentage / 100.0;
1060 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1061 }
1062 return false;
1063 }
1064
1065 // If a method is old enough and is still in the interpreter we would want to
1066 // start profiling without waiting for the compiled method to arrive.
1067 // We also take the load on compilers into the account.
1068 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1069 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1070 return false;
1071 }
1072
1073 if (TrainingData::have_data()) {
1074 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1075 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1076 return true;
1077 }
1078 }
1079
1080 if (is_old(method)) {
1081 return true;
1082 }
1083
1084 int i = method->invocation_count();
1085 int b = method->backedge_count();
1086 double k = Tier0ProfilingStartPercentage / 100.0;
1087
1088 // If the top level compiler is not keeping up, delay profiling.
1089 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1090 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1091 }
1092 return false;
1093 }
1094
1095 // Inlining control: if we're compiling a profiled method with C1 and the callee
1096 // is known to have OSRed in a C2 version, don't inline it.
1097 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1098 CompLevel comp_level = (CompLevel)env->comp_level();
1099 if (comp_level == CompLevel_full_profile ||
1100 comp_level == CompLevel_limited_profile) {
1101 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1102 }
1103 return false;
1104 }
1105
1106 // Create MDO if necessary.
1107 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1108 if (mh->is_native() ||
1109 mh->is_abstract() ||
1110 mh->is_accessor() ||
1111 mh->is_constant_getter()) {
1112 return;
1113 }
1114 if (mh->method_data() == nullptr) {
1115 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1116 }
1117 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1118 MethodData* mdo = mh->method_data();
1119 if (mdo != nullptr) {
1120 frame last_frame = THREAD->last_frame();
1121 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1122 int bci = last_frame.interpreter_frame_bci();
1123 address dp = mdo->bci_to_dp(bci);
1124 last_frame.interpreter_frame_set_mdp(dp);
1125 }
1126 }
1127 }
1128 }
1129
1130 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1131 precond(mtd != nullptr);
1132 precond(cur_level == CompLevel_none);
1133
1134 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1135 return CompLevel_none;
1136 }
1137
1138 bool training_has_profile = (mtd->final_profile() != nullptr);
1139 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1140 return CompLevel_full_profile;
1141 }
1142
1143 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1144 switch (highest_training_level) {
1145 case CompLevel_limited_profile:
1146 case CompLevel_full_profile:
1147 return CompLevel_limited_profile;
1148 case CompLevel_simple:
1149 return CompLevel_simple;
1150 case CompLevel_none:
1151 return CompLevel_none;
1152 default:
1153 break;
1154 }
1155
1156 // Now handle the case of level 4.
1157 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1158 if (!training_has_profile) {
1159 // The method was a part of a level 4 compile, but doesn't have a stored profile,
1160 // we need to profile it.
1161 return CompLevel_full_profile;
1162 }
1163 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1164 // If we deopted, then we reprofile
1165 if (deopt && !is_method_profiled(method)) {
1166 return CompLevel_full_profile;
1167 }
1168
1169 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1170 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1171 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1172 if (SkipTier2IfPossible && ctd->init_deps_left_acquire() == 0) {
1173 if (method->method_data() == nullptr) {
1174 create_mdo(method, THREAD);
1175 }
1176 return CompLevel_full_optimization;
1177 }
1178
1179 // Otherwise go to level 2
1180 return CompLevel_limited_profile;
1181 }
1182
1183
1184 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1185 precond(mtd != nullptr);
1186 precond(cur_level == CompLevel_limited_profile);
1187
1188 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1189
1190 // But first, check if we have a saved profile
1191 bool training_has_profile = (mtd->final_profile() != nullptr);
1192 if (!training_has_profile) {
1193 return CompLevel_full_profile;
1194 }
1195
1196
1197 assert(training_has_profile, "Have to have a profile to be here");
1198 // Check if the method is ready
1199 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1200 if (ctd != nullptr && ctd->init_deps_left_acquire() == 0) {
1201 if (method->method_data() == nullptr) {
1202 create_mdo(method, THREAD);
1203 }
1204 return CompLevel_full_optimization;
1205 }
1206
1207 // Otherwise stay at the current level
1208 return CompLevel_limited_profile;
1209 }
1210
1211
1212 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1213 precond(mtd != nullptr);
1214 precond(cur_level == CompLevel_full_profile);
1215
1216 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1217 // We have method at the full profile level and we also know that it's possibly an important method.
1218 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1219 // Check if it is adequately profiled
1220 if (is_method_profiled(method)) {
1221 return CompLevel_full_optimization;
1222 }
1223 }
1224
1225 // Otherwise stay at the current level
1226 return CompLevel_full_profile;
1227 }
1228
1229 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1230 precond(MethodTrainingData::have_data());
1231
1232 // If there is no training data recorded for this method, bail out.
1233 if (mtd == nullptr) {
1234 return cur_level;
1235 }
1236
1237 CompLevel next_level = cur_level;
1238 switch(cur_level) {
1239 default: break;
1240 case CompLevel_none:
1241 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1242 break;
1243 case CompLevel_limited_profile:
1244 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1245 break;
1246 case CompLevel_full_profile:
1247 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1248 break;
1249 }
1250
1251 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1252 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1253 return CompLevel_none;
1254 }
1255 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1256 return CompLevel_none;
1257 }
1258 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1259 }
1260
1261 /*
1262 * Method states:
1263 * 0 - interpreter (CompLevel_none)
1264 * 1 - pure C1 (CompLevel_simple)
1265 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1266 * 3 - C1 with full profiling (CompLevel_full_profile)
1267 * 4 - C2 or Graal (CompLevel_full_optimization)
1268 *
1269 * Common state transition patterns:
1270 * a. 0 -> 3 -> 4.
1271 * The most common path. But note that even in this straightforward case
1272 * profiling can start at level 0 and finish at level 3.
1273 *
1274 * b. 0 -> 2 -> 3 -> 4.
1275 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1276 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1277 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1278 *
1279 * c. 0 -> (3->2) -> 4.
1280 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1281 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1282 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1283 * without full profiling while c2 is compiling.
1284 *
1285 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1286 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1287 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1288 *
1289 * e. 0 -> 4.
1290 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1291 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1292 * the compiled version already exists).
1293 *
1294 * Note that since state 0 can be reached from any other state via deoptimization different loops
1295 * are possible.
1296 *
1297 */
1298
1299 // Common transition function. Given a predicate determines if a method should transition to another level.
1300 template<typename Predicate>
1301 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1302 CompLevel next_level = cur_level;
1303
1304 if (force_comp_at_level_simple(method)) {
1305 next_level = CompLevel_simple;
1306 } else if (is_trivial(method) || method->is_native()) {
1307 // We do not care if there is profiling data for these methods, throw them to compiler.
1308 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1309 } else if (MethodTrainingData::have_data()) {
1310 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1311 if (mtd == nullptr) {
1312 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1313 // Feed it to the standard TF with no profiling delay.
1314 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1315 } else {
1316 next_level = trained_transition(method, cur_level, mtd, THREAD);
1317 if (cur_level == next_level && !should_delay_standard_transition(method, cur_level, mtd)) {
1318 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1319 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1320 // TF but with profiling delay.
1321 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1322 }
1323 }
1324 } else {
1325 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1326 }
1327 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1328 }
1329
1330 bool CompilationPolicy::should_delay_standard_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd) {
1331 precond(mtd != nullptr);
1332 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1333 if (highest_training_level != CompLevel_full_optimization && cur_level == CompLevel_limited_profile) {
1334 // This is a lukewarm method - it hasn't been compiled with C2 during the tranining run and is currently
1335 // running at level 2. Delay any further state changes until its counters exceed the training run counts.
1336 MethodCounters* mc = method->method_counters();
1337 if (mc == nullptr) {
1338 return false;
1339 }
1340 if (mc->invocation_counter()->carry() || mc->backedge_counter()->carry()) {
1341 return false;
1342 }
1343 if (static_cast<int>(mc->invocation_counter()->count()) <= mtd->invocation_count() &&
1344 static_cast<int>(mc->backedge_counter()->count()) <= mtd->backedge_count()) {
1345 return true;
1346 }
1347 }
1348 return false;
1349 }
1350
1351 template<typename Predicate>
1352 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1353 CompLevel next_level = cur_level;
1354 switch(cur_level) {
1355 default: break;
1356 case CompLevel_none:
1357 next_level = transition_from_none<Predicate>(method, cur_level, disable_feedback);
1358 break;
1359 case CompLevel_limited_profile:
1360 next_level = transition_from_limited_profile<Predicate>(method, cur_level, disable_feedback);
1361 break;
1362 case CompLevel_full_profile:
1363 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1364 break;
1365 }
1366 return next_level;
1367 }
1368
1369 template<typename Predicate>
1370 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1371 precond(cur_level == CompLevel_none);
1372 CompLevel next_level = cur_level;
1373 int i = method->invocation_count();
1374 int b = method->backedge_count();
1375 // If we were at full profile level, would we switch to full opt?
1376 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1377 next_level = CompLevel_full_optimization;
1378 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply(method, cur_level, i, b)) {
1379 // C1-generated fully profiled code is about 30% slower than the limited profile
1380 // code that has only invocation and backedge counters. The observation is that
1381 // if C2 queue is large enough we can spend too much time in the fully profiled code
1382 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1383 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1384 // we choose to compile a limited profiled version and then recompile with full profiling
1385 // when the load on C2 goes down.
1386 if (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization)) {
1387 next_level = CompLevel_limited_profile;
1388 } else {
1389 next_level = CompLevel_full_profile;
1390 }
1391 }
1392 return next_level;
1393 }
1394
1395 template<typename Predicate>
1396 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1397 precond(cur_level == CompLevel_full_profile);
1398 CompLevel next_level = cur_level;
1399 MethodData* mdo = method->method_data();
1400 if (mdo != nullptr) {
1401 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1402 int mdo_i = mdo->invocation_count_delta();
1403 int mdo_b = mdo->backedge_count_delta();
1404 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1405 next_level = CompLevel_full_optimization;
1406 }
1407 } else {
1408 next_level = CompLevel_full_optimization;
1409 }
1410 }
1411 return next_level;
1412 }
1413
1414 template<typename Predicate>
1415 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1416 precond(cur_level == CompLevel_limited_profile);
1417 CompLevel next_level = cur_level;
1418 int i = method->invocation_count();
1419 int b = method->backedge_count();
1420 MethodData* mdo = method->method_data();
1421 if (mdo != nullptr) {
1422 if (mdo->would_profile()) {
1423 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1424 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1425 Predicate::apply(method, cur_level, i, b))) {
1426 next_level = CompLevel_full_profile;
1427 }
1428 } else {
1429 next_level = CompLevel_full_optimization;
1430 }
1431 } else {
1432 // If there is no MDO we need to profile
1433 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1434 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1435 Predicate::apply(method, cur_level, i, b))) {
1436 next_level = CompLevel_full_profile;
1437 }
1438 }
1439 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1440 next_level = CompLevel_full_optimization;
1441 }
1442 return next_level;
1443 }
1444
1445
1446 // Determine if a method should be compiled with a normal entry point at a different level.
1447 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1448 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1449 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1450
1451 // If OSR method level is greater than the regular method level, the levels should be
1452 // equalized by raising the regular method level in order to avoid OSRs during each
1453 // invocation of the method.
1454 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1455 MethodData* mdo = method->method_data();
1456 guarantee(mdo != nullptr, "MDO should not be nullptr");
1457 if (mdo->invocation_count() >= 1) {
1458 next_level = CompLevel_full_optimization;
1459 }
1460 } else {
1461 next_level = MAX2(osr_level, next_level);
1462 }
1463
1464 return next_level;
1465 }
1466
1467 // Determine if we should do an OSR compilation of a given method.
1468 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1469 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1470 if (cur_level == CompLevel_none) {
1471 // If there is a live OSR method that means that we deopted to the interpreter
1472 // for the transition.
1473 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1474 if (osr_level > CompLevel_none) {
1475 return osr_level;
1476 }
1477 }
1478 return next_level;
1479 }
1480
1481 // Handle the invocation event.
1482 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1483 CompLevel level, nmethod* nm, TRAPS) {
1484 if (should_create_mdo(mh, level)) {
1485 create_mdo(mh, THREAD);
1486 }
1487 CompLevel next_level = call_event(mh, level, THREAD);
1488 if (next_level != level) {
1489 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1490 compile(mh, InvocationEntryBci, next_level, THREAD);
1491 }
1492 }
1493 }
1494
1495 // Handle the back branch event. Notice that we can compile the method
1496 // with a regular entry from here.
1497 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1498 int bci, CompLevel level, nmethod* nm, TRAPS) {
1499 if (should_create_mdo(mh, level)) {
1500 create_mdo(mh, THREAD);
1501 }
1502 // Check if MDO should be created for the inlined method
1503 if (should_create_mdo(imh, level)) {
1504 create_mdo(imh, THREAD);
1505 }
1506
1507 if (is_compilation_enabled()) {
1508 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1509 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1510 // At the very least compile the OSR version
1511 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1512 compile(imh, bci, next_osr_level, CHECK);
1513 }
1514
1515 // Use loop event as an opportunity to also check if there's been
1516 // enough calls.
1517 CompLevel cur_level, next_level;
1518 if (mh() != imh()) { // If there is an enclosing method
1519 {
1520 guarantee(nm != nullptr, "Should have nmethod here");
1521 cur_level = comp_level(mh());
1522 next_level = call_event(mh, cur_level, THREAD);
1523
1524 if (max_osr_level == CompLevel_full_optimization) {
1525 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1526 bool make_not_entrant = false;
1527 if (nm->is_osr_method()) {
1528 // This is an osr method, just make it not entrant and recompile later if needed
1529 make_not_entrant = true;
1530 } else {
1531 if (next_level != CompLevel_full_optimization) {
1532 // next_level is not full opt, so we need to recompile the
1533 // enclosing method without the inlinee
1534 cur_level = CompLevel_none;
1535 make_not_entrant = true;
1536 }
1537 }
1538 if (make_not_entrant) {
1539 if (PrintTieredEvents) {
1540 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1541 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1542 }
1543 nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_BACK_BRANCH);
1544 }
1545 }
1546 // Fix up next_level if necessary to avoid deopts
1547 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1548 next_level = CompLevel_full_profile;
1549 }
1550 if (cur_level != next_level) {
1551 if (!CompileBroker::compilation_is_in_queue(mh)) {
1552 compile(mh, InvocationEntryBci, next_level, THREAD);
1553 }
1554 }
1555 }
1556 } else {
1557 cur_level = comp_level(mh());
1558 next_level = call_event(mh, cur_level, THREAD);
1559 if (next_level != cur_level) {
1560 if (!CompileBroker::compilation_is_in_queue(mh)) {
1561 compile(mh, InvocationEntryBci, next_level, THREAD);
1562 }
1563 }
1564 }
1565 }
1566 }
1567