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/aotCodeCache.hpp"
27 #include "code/scopeDesc.hpp"
28 #include "compiler/compilationPolicy.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "compiler/compilerDefinitions.inline.hpp"
31 #include "compiler/compilerOracle.hpp"
32 #include "compiler/recompilationPolicy.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/method.inline.hpp"
35 #include "oops/methodData.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/trainingData.hpp"
38 #include "prims/jvmtiExport.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/frame.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/globals_extension.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/safepoint.hpp"
46 #include "runtime/safepointVerifiers.hpp"
47 #ifdef COMPILER1
48 #include "c1/c1_Compiler.hpp"
49 #endif
50 #ifdef COMPILER2
51 #include "opto/c2compiler.hpp"
52 #endif
53 #if INCLUDE_JVMCI
54 #include "jvmci/jvmci.hpp"
55 #endif
56
57 int64_t CompilationPolicy::_start_time = 0;
58 int CompilationPolicy::_c1_count = 0;
59 int CompilationPolicy::_c2_count = 0;
60 int CompilationPolicy::_ac_count = 0;
61 double CompilationPolicy::_increase_threshold_at_ratio = 0;
62
63 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
64
65 void compilationPolicy_init() {
66 CompilationPolicy::initialize();
67 }
68
69 int CompilationPolicy::compiler_count(CompLevel comp_level) {
70 if (is_c1_compile(comp_level)) {
71 return c1_count();
72 } else if (is_c2_compile(comp_level)) {
73 return c2_count();
74 }
75 return 0;
76 }
77
78 // Returns true if m must be compiled before executing it
79 // This is intended to force compiles for methods (usually for
80 // debugging) that would otherwise be interpreted for some reason.
81 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
82 // Don't allow Xcomp to cause compiles in replay mode
83 if (ReplayCompiles) return false;
84
85 if (m->has_compiled_code()) return false; // already compiled
86 if (!can_be_compiled(m, comp_level)) return false;
87
88 return !UseInterpreter || // must compile all methods
89 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
90 }
91
92 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
93 if (m->method_holder()->is_not_initialized()) {
94 // 'is_not_initialized' means not only '!is_initialized', but also that
95 // initialization has not been started yet ('!being_initialized')
96 // Do not force compilation of methods in uninitialized classes.
97 return;
98 }
99 if (!m->is_native() && MethodTrainingData::have_data()) {
100 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
101 if (mtd == nullptr) {
102 return; // there is no training data recorded for m
103 }
104 // AOT Preload code with class init barriers is used,
105 // consider replacing it with normal (faster) AOT code
106 bool recompile = m->code_has_clinit_barriers();
107 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
108 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
109 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
110 bool requires_online_compilation = false;
111 CompileTrainingData* ctd = mtd->last_toplevel_compile(next_level);
112 if (ctd != nullptr) {
113 // Can't load normal AOT code - not all dependancies are ready,
114 // request normal compilation
115 requires_online_compilation = (ctd->init_deps_left() > 0);
116 }
117 if (requires_online_compilation && recompile) {
118 // Wait when dependencies are ready to load normal AOT code
119 // if AOT Preload code is used now.
120 //
121 // FIXME. We may never (or it take long time) get all dependencies
122 // be ready to replace AOT Preload code. Consider using time and how many
123 // dependencies left to allow normal JIT compilation for replacement.
124 return;
125 }
126 if (PrintTieredEvents) {
127 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
128 }
129 CompileBroker::compile_method(m, InvocationEntryBci, next_level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
130 if (HAS_PENDING_EXCEPTION) {
131 CLEAR_PENDING_EXCEPTION;
132 }
133 }
134 }
135 }
136
137 void CompilationPolicy::maybe_compile_early_after_init(const methodHandle& m, TRAPS) {
138 assert(m->method_holder()->is_initialized(), "Should be called after class initialization");
139 maybe_compile_early(m, THREAD);
140 }
141
142 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
143 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
144 // don't force compilation, resolve was on behalf of compiler
145 return;
146 }
147 if (m->method_holder()->is_not_initialized()) {
148 // 'is_not_initialized' means not only '!is_initialized', but also that
149 // initialization has not been started yet ('!being_initialized')
150 // Do not force compilation of methods in uninitialized classes.
151 // Note that doing this would throw an assert later,
152 // in CompileBroker::compile_method.
153 // We sometimes use the link resolver to do reflective lookups
154 // even before classes are initialized.
155 return;
156 }
157
158 if (must_be_compiled(m)) {
159 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
160 CompLevel level = initial_compile_level(m);
161 if (PrintTieredEvents) {
162 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
163 }
164 // Test AOT code too
165 bool requires_online_compilation = false;
166 if (TrainingData::have_data()) {
167 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
168 if (mtd != nullptr) {
169 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
170 if (ctd != nullptr) {
171 requires_online_compilation = (ctd->init_deps_left() > 0);
172 }
173 }
174 }
175 CompileBroker::compile_method(m, InvocationEntryBci, level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
176 }
177 }
178
179 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, TRAPS) {
180 if (!klass->has_init_deps_processed()) {
181 ResourceMark rm;
182 log_debug(training)("Replay training: %s", klass->external_name());
183
184 KlassTrainingData* ktd = KlassTrainingData::find(klass);
185 if (ktd != nullptr) {
186 guarantee(ktd->has_holder(), "");
187 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
188 assert(klass->has_init_deps_processed(), "");
189
190 if (AOTCompileEagerly) {
191 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
192 if (ctd->init_deps_left() == 0) {
193 MethodTrainingData* mtd = ctd->method();
194 if (mtd->has_holder()) {
195 const methodHandle mh(THREAD, const_cast<Method*>(mtd->holder()));
196 CompilationPolicy::maybe_compile_early(mh, THREAD);
197 }
198 }
199 });
200 }
201 }
202 }
203 }
204
205 void CompilationPolicy::flush_replay_training_at_init(TRAPS) {
206 MonitorLocker locker(THREAD, TrainingReplayQueue_lock);
207 while (!_training_replay_queue.is_empty_unlocked()) {
208 locker.wait(); // let the replay training thread drain the queue
209 }
210 }
211
212 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, TRAPS) {
213 assert(klass->is_initialized(), "");
214 if (TrainingData::have_data() && klass->is_shared()) {
215 _training_replay_queue.push(klass, TrainingReplayQueue_lock, THREAD);
216 }
217 }
218
219 // For TrainingReplayQueue
220 template<>
221 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
222 int pos = 0;
223 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
224 ResourceMark rm;
225 InstanceKlass* ik = cur->value();
226 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
227 }
228 }
229
230 void CompilationPolicy::replay_training_at_init_loop(TRAPS) {
231 while (!CompileBroker::is_compilation_disabled_forever() || AOTVerifyTrainingData) {
232 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, THREAD);
233 if (ik != nullptr) {
234 replay_training_at_init_impl(ik, THREAD);
235 }
236 }
237 }
238
239 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
240 if (comp_level == CompLevel_any) {
241 if (CompilerConfig::is_c1_only()) {
242 comp_level = CompLevel_simple;
243 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
244 comp_level = CompLevel_full_optimization;
245 }
246 }
247 return comp_level;
248 }
249
250 // Returns true if m is allowed to be compiled
251 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
252 // allow any levels for WhiteBox
253 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
254
255 if (m->is_abstract()) return false;
256 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
257
258 // Math intrinsics should never be compiled as this can lead to
259 // monotonicity problems because the interpreter will prefer the
260 // compiled code to the intrinsic version. This can't happen in
261 // production because the invocation counter can't be incremented
262 // but we shouldn't expose the system to this problem in testing
263 // modes.
264 if (!AbstractInterpreter::can_be_compiled(m)) {
265 return false;
266 }
267 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
268 if (comp_level == CompLevel_any || is_compile(comp_level)) {
269 return !m->is_not_compilable(comp_level);
270 }
271 return false;
272 }
273
274 // Returns true if m is allowed to be osr compiled
275 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
276 bool result = false;
277 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
278 if (comp_level == CompLevel_any || is_compile(comp_level)) {
279 result = !m->is_not_osr_compilable(comp_level);
280 }
281 return (result && can_be_compiled(m, comp_level));
282 }
283
284 bool CompilationPolicy::is_compilation_enabled() {
285 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
286 return CompileBroker::should_compile_new_jobs();
287 }
288
289 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
290 // Remove unloaded methods from the queue
291 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
292 CompileTask* next = task->next();
293 if (task->is_unloaded()) {
294 compile_queue->remove_and_mark_stale(task);
295 }
296 task = next;
297 }
298 #if INCLUDE_JVMCI
299 if (UseJVMCICompiler && !BackgroundCompilation) {
300 /*
301 * In blocking compilation mode, the CompileBroker will make
302 * compilations submitted by a JVMCI compiler thread non-blocking. These
303 * compilations should be scheduled after all blocking compilations
304 * to service non-compiler related compilations sooner and reduce the
305 * chance of such compilations timing out.
306 */
307 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
308 if (task->is_blocking()) {
309 return task;
310 }
311 }
312 }
313 #endif
314 return compile_queue->first();
315 }
316
317 // Simple methods are as good being compiled with C1 as C2.
318 // Determine if a given method is such a case.
319 bool CompilationPolicy::is_trivial(const methodHandle& method) {
320 if (method->is_accessor() ||
321 method->is_constant_getter()) {
322 return true;
323 }
324 return false;
325 }
326
327 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
328 if (CompilationModeFlag::quick_internal()) {
329 #if INCLUDE_JVMCI
330 if (UseJVMCICompiler) {
331 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
332 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
333 return true;
334 }
335 }
336 #endif
337 }
338 return false;
339 }
340
341 CompLevel CompilationPolicy::comp_level(Method* method) {
342 nmethod *nm = method->code();
343 if (nm != nullptr && nm->is_in_use()) {
344 return (CompLevel)nm->comp_level();
345 }
346 return CompLevel_none;
347 }
348
349 // Call and loop predicates determine whether a transition to a higher
350 // compilation level should be performed (pointers to predicate functions
351 // are passed to common()).
352 // Tier?LoadFeedback is basically a coefficient that determines of
353 // how many methods per compiler thread can be in the queue before
354 // the threshold values double.
355 class LoopPredicate : AllStatic {
356 public:
357 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
358 double threshold_scaling;
359 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
360 scale *= threshold_scaling;
361 }
362 switch(cur_level) {
363 case CompLevel_none:
364 case CompLevel_limited_profile:
365 return b >= Tier3BackEdgeThreshold * scale;
366 case CompLevel_full_profile:
367 return b >= Tier4BackEdgeThreshold * scale;
368 default:
369 return true;
370 }
371 }
372
373 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
374 double k = 1;
375 switch(cur_level) {
376 case CompLevel_none:
377 // Fall through
378 case CompLevel_limited_profile: {
379 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
380 break;
381 }
382 case CompLevel_full_profile: {
383 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
384 break;
385 }
386 default:
387 return true;
388 }
389 return apply_scaled(method, cur_level, i, b, k);
390 }
391 };
392
393 class CallPredicate : AllStatic {
394 public:
395 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
396 double threshold_scaling;
397 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
398 scale *= threshold_scaling;
399 }
400 switch(cur_level) {
401 case CompLevel_none:
402 case CompLevel_limited_profile:
403 return (i >= Tier3InvocationThreshold * scale) ||
404 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
405 case CompLevel_full_profile:
406 return (i >= Tier4InvocationThreshold * scale) ||
407 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
408 default:
409 return true;
410 }
411 }
412
413 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
414 double k = 1;
415 switch(cur_level) {
416 case CompLevel_none:
417 case CompLevel_limited_profile: {
418 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
419 break;
420 }
421 case CompLevel_full_profile: {
422 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
423 break;
424 }
425 default:
426 return true;
427 }
428 return apply_scaled(method, cur_level, i, b, k);
429 }
430 };
431
432 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
433 int comp_count = compiler_count(level);
434 if (comp_count > 0) {
435 double queue_size = CompileBroker::queue_size(level);
436 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
437
438 // Increase C1 compile threshold when the code cache is filled more
439 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
440 // The main intention is to keep enough free space for C2 compiled code
441 // to achieve peak performance if the code cache is under stress.
442 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
443 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
444 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
445 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
446 }
447 }
448 return k;
449 }
450 return 1;
451 }
452
453 void CompilationPolicy::print_counters(const char* prefix, Method* m) {
454 int invocation_count = m->invocation_count();
455 int backedge_count = m->backedge_count();
456 MethodData* mdh = m->method_data();
457 int mdo_invocations = 0, mdo_backedges = 0;
458 int mdo_invocations_start = 0, mdo_backedges_start = 0;
459 if (mdh != nullptr) {
460 mdo_invocations = mdh->invocation_count();
461 mdo_backedges = mdh->backedge_count();
462 mdo_invocations_start = mdh->invocation_count_start();
463 mdo_backedges_start = mdh->backedge_count_start();
464 }
465 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
466 invocation_count, backedge_count, prefix,
467 mdo_invocations, mdo_invocations_start,
468 mdo_backedges, mdo_backedges_start);
469 tty->print(" %smax levels=%d,%d", prefix,
470 m->highest_comp_level(), m->highest_osr_comp_level());
471 }
472
473 void CompilationPolicy::print_training_data(const char* prefix, Method* method) {
474 methodHandle m(Thread::current(), method);
475 tty->print(" %smtd: ", prefix);
476 MethodTrainingData* mtd = MethodTrainingData::find(m);
477 if (mtd == nullptr) {
478 tty->print("null");
479 } else {
480 MethodData* md = mtd->final_profile();
481 tty->print("mdo=");
482 if (md == nullptr) {
483 tty->print("null");
484 } else {
485 int mdo_invocations = md->invocation_count();
486 int mdo_backedges = md->backedge_count();
487 int mdo_invocations_start = md->invocation_count_start();
488 int mdo_backedges_start = md->backedge_count_start();
489 tty->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
490 }
491 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
492 tty->print(", deps=");
493 if (ctd == nullptr) {
494 tty->print("null");
495 } else {
496 tty->print("%d", ctd->init_deps_left());
497 }
498 }
499 }
500
501 // Print an event.
502 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
503 bool inlinee_event = m != im;
504
505 ttyLocker tty_lock;
506 tty->print("%lf: [", os::elapsedTime());
507
508 switch(type) {
509 case CALL:
510 tty->print("call");
511 break;
512 case LOOP:
513 tty->print("loop");
514 break;
515 case COMPILE:
516 tty->print("compile");
517 break;
518 case FORCE_COMPILE:
519 tty->print("force-compile");
520 break;
521 case FORCE_RECOMPILE:
522 tty->print("force-recompile");
523 break;
524 case REMOVE_FROM_QUEUE:
525 tty->print("remove-from-queue");
526 break;
527 case UPDATE_IN_QUEUE:
528 tty->print("update-in-queue");
529 break;
530 case REPROFILE:
531 tty->print("reprofile");
532 break;
533 case MAKE_NOT_ENTRANT:
534 tty->print("make-not-entrant");
535 break;
536 default:
537 tty->print("unknown");
538 }
539
540 tty->print(" level=%d ", level);
541
542 ResourceMark rm;
543 char *method_name = m->name_and_sig_as_C_string();
544 tty->print("[%s", method_name);
545 if (inlinee_event) {
546 char *inlinee_name = im->name_and_sig_as_C_string();
547 tty->print(" [%s]] ", inlinee_name);
548 }
549 else tty->print("] ");
550 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
551 CompileBroker::queue_size(CompLevel_full_optimization));
552
553 tty->print(" rate=");
554 if (m->prev_time() == 0) tty->print("n/a");
555 else tty->print("%f", m->rate());
556
557 RecompilationPolicy::print_load_average();
558
559 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
560 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
561
562 if (type != COMPILE) {
563 print_counters("", m);
564 if (inlinee_event) {
565 print_counters("inlinee ", im);
566 }
567 tty->print(" compilable=");
568 bool need_comma = false;
569 if (!m->is_not_compilable(CompLevel_full_profile)) {
570 tty->print("c1");
571 need_comma = true;
572 }
573 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
574 if (need_comma) tty->print(",");
575 tty->print("c1-osr");
576 need_comma = true;
577 }
578 if (!m->is_not_compilable(CompLevel_full_optimization)) {
579 if (need_comma) tty->print(",");
580 tty->print("c2");
581 need_comma = true;
582 }
583 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
584 if (need_comma) tty->print(",");
585 tty->print("c2-osr");
586 }
587 tty->print(" status=");
588 if (m->queued_for_compilation()) {
589 tty->print("in-queue");
590 } else tty->print("idle");
591 print_training_data("", m);
592 if (inlinee_event) {
593 print_training_data("inlinee ", im);
594 }
595 }
596 tty->print_cr("]");
597 }
598
599 void CompilationPolicy::initialize() {
600 if (!CompilerConfig::is_interpreter_only()) {
601 int count = CICompilerCount;
602 bool c1_only = CompilerConfig::is_c1_only();
603 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
604
605 #ifdef _LP64
606 // Turn on ergonomic compiler count selection
607 if (AOTCodeCache::maybe_dumping_code()) {
608 // Assembly phase runs C1 and C2 compilation in separate phases,
609 // and can use all the CPU threads it can reach. Adjust the common
610 // options before policy starts overwriting them.
611 FLAG_SET_ERGO_IF_DEFAULT(UseDynamicNumberOfCompilerThreads, false);
612 FLAG_SET_ERGO_IF_DEFAULT(CICompilerCountPerCPU, false);
613 if (FLAG_IS_DEFAULT(CICompilerCount)) {
614 count = MAX2(count, os::active_processor_count());
615 }
616 }
617 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
618 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
619 }
620 if (CICompilerCountPerCPU) {
621 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
622 int log_cpu = log2i(os::active_processor_count());
623 int loglog_cpu = log2i(MAX2(log_cpu, 1));
624 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
625 }
626 if (FLAG_IS_DEFAULT(CICompilerCount)) {
627 // Make sure there is enough space in the code cache to hold all the compiler buffers
628 size_t c1_size = 0;
629 #ifdef COMPILER1
630 c1_size = Compiler::code_buffer_size();
631 #endif
632 size_t c2_size = 0;
633 #ifdef COMPILER2
634 c2_size = C2Compiler::initial_code_buffer_size();
635 #endif
636 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
637 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
638 if (count > max_count) {
639 // Lower the compiler count such that all buffers fit into the code cache
640 count = MAX2(max_count, c1_only ? 1 : 2);
641 }
642 FLAG_SET_ERGO(CICompilerCount, count);
643 }
644 #else
645 // On 32-bit systems, the number of compiler threads is limited to 3.
646 // On these systems, the virtual address space available to the JVM
647 // is usually limited to 2-4 GB (the exact value depends on the platform).
648 // As the compilers (especially C2) can consume a large amount of
649 // memory, scaling the number of compiler threads with the number of
650 // available cores can result in the exhaustion of the address space
651 /// available to the VM and thus cause the VM to crash.
652 if (FLAG_IS_DEFAULT(CICompilerCount)) {
653 count = 3;
654 FLAG_SET_ERGO(CICompilerCount, count);
655 }
656 #endif
657
658 if (c1_only) {
659 // No C2 compiler thread required
660 set_c1_count(count);
661 } else if (c2_only) {
662 set_c2_count(count);
663 } else {
664 #if INCLUDE_JVMCI
665 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
666 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
667 int c1_count = MAX2(count - libjvmci_count, 1);
668 set_c2_count(libjvmci_count);
669 set_c1_count(c1_count);
670 } else
671 #endif
672 {
673 set_c1_count(MAX2(count / 3, 1));
674 set_c2_count(MAX2(count - c1_count(), 1));
675 }
676 }
677 if (AOTCodeCache::is_code_load_thread_on()) {
678 set_ac_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 AOT code in parallel
679 }
680 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
681 set_increase_threshold_at_ratio();
682 }
683
684 set_start_time(nanos_to_millis(os::javaTimeNanos()));
685 }
686
687
688 #ifdef ASSERT
689 bool CompilationPolicy::verify_level(CompLevel level) {
690 if (TieredCompilation && level > TieredStopAtLevel) {
691 return false;
692 }
693 // Check if there is a compiler to process the requested level
694 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
695 return false;
696 }
697 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
698 return false;
699 }
700
701 // Interpreter level is always valid.
702 if (level == CompLevel_none) {
703 return true;
704 }
705 if (CompilationModeFlag::normal()) {
706 return true;
707 } else if (CompilationModeFlag::quick_only()) {
708 return level == CompLevel_simple;
709 } else if (CompilationModeFlag::high_only()) {
710 return level == CompLevel_full_optimization;
711 } else if (CompilationModeFlag::high_only_quick_internal()) {
712 return level == CompLevel_full_optimization || level == CompLevel_simple;
713 }
714 return false;
715 }
716 #endif
717
718
719 CompLevel CompilationPolicy::highest_compile_level() {
720 CompLevel level = CompLevel_none;
721 // Setup the maximum level available for the current compiler configuration.
722 if (!CompilerConfig::is_interpreter_only()) {
723 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
724 level = CompLevel_full_optimization;
725 } else if (CompilerConfig::is_c1_enabled()) {
726 if (CompilerConfig::is_c1_simple_only()) {
727 level = CompLevel_simple;
728 } else {
729 level = CompLevel_full_profile;
730 }
731 }
732 }
733 // Clamp the maximum level with TieredStopAtLevel.
734 if (TieredCompilation) {
735 level = MIN2(level, (CompLevel) TieredStopAtLevel);
736 }
737
738 // Fix it up if after the clamping it has become invalid.
739 // Bring it monotonically down depending on the next available level for
740 // the compilation mode.
741 if (!CompilationModeFlag::normal()) {
742 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
743 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
744 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
745 if (CompilationModeFlag::quick_only()) {
746 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
747 level = CompLevel_simple;
748 }
749 } else if (CompilationModeFlag::high_only()) {
750 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
751 level = CompLevel_none;
752 }
753 } else if (CompilationModeFlag::high_only_quick_internal()) {
754 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
755 level = CompLevel_simple;
756 }
757 }
758 }
759
760 assert(verify_level(level), "Invalid highest compilation level: %d", level);
761 return level;
762 }
763
764 CompLevel CompilationPolicy::limit_level(CompLevel level) {
765 level = MIN2(level, highest_compile_level());
766 assert(verify_level(level), "Invalid compilation level: %d", level);
767 return level;
768 }
769
770 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
771 CompLevel level = CompLevel_any;
772 if (CompilationModeFlag::normal()) {
773 level = CompLevel_full_profile;
774 } else if (CompilationModeFlag::quick_only()) {
775 level = CompLevel_simple;
776 } else if (CompilationModeFlag::high_only()) {
777 level = CompLevel_full_optimization;
778 } else if (CompilationModeFlag::high_only_quick_internal()) {
779 if (force_comp_at_level_simple(method)) {
780 level = CompLevel_simple;
781 } else {
782 level = CompLevel_full_optimization;
783 }
784 }
785 assert(level != CompLevel_any, "Unhandled compilation mode");
786 return limit_level(level);
787 }
788
789 // Set carry flags on the counters if necessary
790 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
791 MethodCounters *mcs = method->method_counters();
792 if (mcs != nullptr) {
793 mcs->invocation_counter()->set_carry_on_overflow();
794 mcs->backedge_counter()->set_carry_on_overflow();
795 }
796 MethodData* mdo = method->method_data();
797 if (mdo != nullptr) {
798 mdo->invocation_counter()->set_carry_on_overflow();
799 mdo->backedge_counter()->set_carry_on_overflow();
800 }
801 }
802
803 // Called with the queue locked and with at least one element
804 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
805 CompileTask *max_blocking_task = nullptr;
806 CompileTask *max_task = nullptr;
807 Method* max_method = nullptr;
808
809 int64_t t = nanos_to_millis(os::javaTimeNanos());
810 // Iterate through the queue and find a method with a maximum rate.
811 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
812 CompileTask* next_task = task->next();
813 // If a method was unloaded or has been stale for some time, remove it from the queue.
814 // Blocking tasks and tasks submitted from whitebox API don't become stale
815 if (task->is_unloaded()) {
816 compile_queue->remove_and_mark_stale(task);
817 task = next_task;
818 continue;
819 }
820 if (task->is_aot_load()) {
821 // AOTCodeCache tasks are on separate queue, and they should load fast. There is no need to walk
822 // the rest of the queue, just take the task and go.
823 return task;
824 }
825 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
826 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
827 // selection and/or any level adjustments. Just return them in order.
828 return task;
829 }
830 Method* method = task->method();
831 methodHandle mh(THREAD, method);
832 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
833 if (PrintTieredEvents) {
834 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
835 }
836 method->clear_queued_for_compilation();
837 method->set_pending_queue_processed(false);
838 compile_queue->remove_and_mark_stale(task);
839 task = next_task;
840 continue;
841 }
842 update_rate(t, mh);
843 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
844 // Select a method with the highest rate
845 max_task = task;
846 max_method = method;
847 }
848
849 if (task->is_blocking()) {
850 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
851 max_blocking_task = task;
852 }
853 }
854
855 task = next_task;
856 }
857
858 if (max_blocking_task != nullptr) {
859 // In blocking compilation mode, the CompileBroker will make
860 // compilations submitted by a JVMCI compiler thread non-blocking. These
861 // compilations should be scheduled after all blocking compilations
862 // to service non-compiler related compilations sooner and reduce the
863 // chance of such compilations timing out.
864 max_task = max_blocking_task;
865 max_method = max_task->method();
866 }
867
868 methodHandle max_method_h(THREAD, max_method);
869
870 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
871 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
872 max_task->set_comp_level(CompLevel_limited_profile);
873
874 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
875 false /* requires_online_compilation */,
876 CompileTask::Reason_None)) {
877 if (PrintTieredEvents) {
878 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
879 }
880 compile_queue->remove_and_mark_stale(max_task);
881 max_method->clear_queued_for_compilation();
882 return nullptr;
883 }
884
885 if (PrintTieredEvents) {
886 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
887 }
888 }
889
890 return max_task;
891 }
892
893 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
894 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
895 if (PrintTieredEvents) {
896 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
897 }
898 MethodData* mdo = sd->method()->method_data();
899 if (mdo != nullptr) {
900 mdo->reset_start_counters();
901 }
902 if (sd->is_top()) break;
903 }
904 }
905
906 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
907 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
908 if (PrintTieredEvents) {
909 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
910 }
911
912 #if INCLUDE_JVMCI
913 if (EnableJVMCI && UseJVMCICompiler &&
914 comp_level == CompLevel_full_optimization CDS_ONLY(&& !AOTLinkedClassBulkLoader::class_preloading_finished())) {
915 return nullptr;
916 }
917 #endif
918
919 if (comp_level == CompLevel_none &&
920 JvmtiExport::can_post_interpreter_events() &&
921 THREAD->is_interp_only_mode()) {
922 return nullptr;
923 }
924 if (ReplayCompiles) {
925 // Don't trigger other compiles in testing mode
926 return nullptr;
927 }
928
929 handle_counter_overflow(method);
930 if (method() != inlinee()) {
931 handle_counter_overflow(inlinee);
932 }
933
934 if (bci == InvocationEntryBci) {
935 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
936 } else {
937 // method == inlinee if the event originated in the main method
938 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
939 // Check if event led to a higher level OSR compilation
940 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
941 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
942 // It's not possible to reach the expected level so fall back to simple.
943 expected_comp_level = CompLevel_simple;
944 }
945 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
946 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
947 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
948 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
949 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
950 // Perform OSR with new nmethod
951 return osr_nm;
952 }
953 }
954 }
955 return nullptr;
956 }
957
958 // Check if the method can be compiled, change level if necessary
959 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
960 assert(verify_level(level), "Invalid compilation level requested: %d", level);
961
962 if (level == CompLevel_none) {
963 if (mh->has_compiled_code()) {
964 // Happens when we switch to interpreter to profile.
965 MutexLocker ml(Compile_lock);
966 NoSafepointVerifier nsv;
967 if (mh->has_compiled_code()) {
968 mh->code()->make_not_used();
969 }
970 // Deoptimize immediately (we don't have to wait for a compile).
971 JavaThread* jt = THREAD;
972 RegisterMap map(jt,
973 RegisterMap::UpdateMap::skip,
974 RegisterMap::ProcessFrames::include,
975 RegisterMap::WalkContinuation::skip);
976 frame fr = jt->last_frame().sender(&map);
977 Deoptimization::deoptimize_frame(jt, fr.id());
978 }
979 return;
980 }
981
982 if (!CompilationModeFlag::disable_intermediate()) {
983 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
984 // in the interpreter and then compile with C2 (the transition function will request that,
985 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
986 // pure C1.
987 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
988 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
989 compile(mh, bci, CompLevel_simple, THREAD);
990 }
991 return;
992 }
993 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
994 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
995 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
996 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
997 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
998 osr_nm->make_not_entrant("OSR invalidation for compiling with C1");
999 }
1000 compile(mh, bci, CompLevel_simple, THREAD);
1001 }
1002 return;
1003 }
1004 }
1005 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
1006 return;
1007 }
1008 if (!CompileBroker::compilation_is_in_queue(mh)) {
1009 if (PrintTieredEvents) {
1010 print_event(COMPILE, mh(), mh(), bci, level);
1011 }
1012 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
1013 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
1014 bool requires_online_compilation = false;
1015 if (TrainingData::have_data()) {
1016 MethodTrainingData* mtd = MethodTrainingData::find_fast(mh);
1017 if (mtd != nullptr) {
1018 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
1019 if (ctd != nullptr) {
1020 requires_online_compilation = (ctd->init_deps_left() > 0);
1021 }
1022 }
1023 }
1024 CompileBroker::compile_method(mh, bci, level, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
1025 }
1026 }
1027
1028 // update_rate() is called from select_task() while holding a compile queue lock.
1029 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
1030 // Skip update if counters are absent.
1031 // Can't allocate them since we are holding compile queue lock.
1032 if (method->method_counters() == nullptr) return;
1033
1034 if (is_old(method)) {
1035 // We don't remove old methods from the queue,
1036 // so we can just zero the rate.
1037 method->set_rate(0);
1038 return;
1039 }
1040
1041 // We don't update the rate if we've just came out of a safepoint.
1042 // delta_s is the time since last safepoint in milliseconds.
1043 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1044 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1045 // How many events were there since the last time?
1046 int event_count = method->invocation_count() + method->backedge_count();
1047 int delta_e = event_count - method->prev_event_count();
1048
1049 // We should be running for at least 1ms.
1050 if (delta_s >= TieredRateUpdateMinTime) {
1051 // And we must've taken the previous point at least 1ms before.
1052 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1053 method->set_prev_time(t);
1054 method->set_prev_event_count(event_count);
1055 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1056 } else {
1057 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1058 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1059 method->set_rate(0);
1060 }
1061 }
1062 }
1063 }
1064
1065 // Check if this method has been stale for a given number of milliseconds.
1066 // See select_task().
1067 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1068 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1069 int64_t delta_t = t - method->prev_time();
1070 if (delta_t > timeout && delta_s > timeout) {
1071 int event_count = method->invocation_count() + method->backedge_count();
1072 int delta_e = event_count - method->prev_event_count();
1073 // Return true if there were no events.
1074 return delta_e == 0;
1075 }
1076 return false;
1077 }
1078
1079 // We don't remove old methods from the compile queue even if they have
1080 // very low activity. See select_task().
1081 bool CompilationPolicy::is_old(const methodHandle& method) {
1082 int i = method->invocation_count();
1083 int b = method->backedge_count();
1084 double k = TieredOldPercentage / 100.0;
1085
1086 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1087 }
1088
1089 double CompilationPolicy::weight(Method* method) {
1090 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1091 }
1092
1093 // Apply heuristics and return true if x should be compiled before y
1094 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1095 if (x->highest_comp_level() > y->highest_comp_level()) {
1096 // recompilation after deopt
1097 return true;
1098 } else
1099 if (x->highest_comp_level() == y->highest_comp_level()) {
1100 if (weight(x) > weight(y)) {
1101 return true;
1102 }
1103 }
1104 return false;
1105 }
1106
1107 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1108 assert(!x->is_aot_load() && !y->is_aot_load(), "AOT code caching tasks are not expected here");
1109 if (x->compile_reason() != y->compile_reason() && y->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1110 return true;
1111 }
1112 return false;
1113 }
1114
1115 // Is method profiled enough?
1116 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1117 MethodData* mdo = method->method_data();
1118 if (mdo != nullptr) {
1119 int i = mdo->invocation_count_delta();
1120 int b = mdo->backedge_count_delta();
1121 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1122 }
1123 return false;
1124 }
1125
1126
1127 // Determine is a method is mature.
1128 bool CompilationPolicy::is_mature(MethodData* mdo) {
1129 if (Arguments::is_compiler_only()) {
1130 // Always report profiles as immature with -Xcomp
1131 return false;
1132 }
1133 methodHandle mh(Thread::current(), mdo->method());
1134 if (mdo != nullptr) {
1135 int i = mdo->invocation_count();
1136 int b = mdo->backedge_count();
1137 double k = ProfileMaturityPercentage / 100.0;
1138 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1139 }
1140 return false;
1141 }
1142
1143 // If a method is old enough and is still in the interpreter we would want to
1144 // start profiling without waiting for the compiled method to arrive.
1145 // We also take the load on compilers into the account.
1146 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1147 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1148 return false;
1149 }
1150
1151 if (TrainingData::have_data()) {
1152 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1153 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1154 return true;
1155 }
1156 }
1157
1158 if (is_old(method)) {
1159 return true;
1160 }
1161 int i = method->invocation_count();
1162 int b = method->backedge_count();
1163 double k = Tier0ProfilingStartPercentage / 100.0;
1164
1165 // If the top level compiler is not keeping up, delay profiling.
1166 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1167 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1168 }
1169 return false;
1170 }
1171
1172 // Inlining control: if we're compiling a profiled method with C1 and the callee
1173 // is known to have OSRed in a C2 version, don't inline it.
1174 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1175 CompLevel comp_level = (CompLevel)env->comp_level();
1176 if (comp_level == CompLevel_full_profile ||
1177 comp_level == CompLevel_limited_profile) {
1178 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1179 }
1180 return false;
1181 }
1182
1183 // Create MDO if necessary.
1184 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1185 if (mh->is_native() ||
1186 mh->is_abstract() ||
1187 mh->is_accessor() ||
1188 mh->is_constant_getter()) {
1189 return;
1190 }
1191 if (mh->method_data() == nullptr) {
1192 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1193 }
1194 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1195 MethodData* mdo = mh->method_data();
1196 if (mdo != nullptr) {
1197 frame last_frame = THREAD->last_frame();
1198 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1199 int bci = last_frame.interpreter_frame_bci();
1200 address dp = mdo->bci_to_dp(bci);
1201 last_frame.interpreter_frame_set_mdp(dp);
1202 }
1203 }
1204 }
1205 }
1206
1207 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1208 precond(mtd != nullptr);
1209 precond(cur_level == CompLevel_none);
1210
1211 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1212 return CompLevel_none;
1213 }
1214
1215 bool training_has_profile = (mtd->final_profile() != nullptr);
1216 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1217 return CompLevel_full_profile;
1218 }
1219
1220 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1221 switch (highest_training_level) {
1222 case CompLevel_limited_profile:
1223 case CompLevel_full_profile:
1224 return CompLevel_limited_profile;
1225 case CompLevel_simple:
1226 return CompLevel_simple;
1227 case CompLevel_none:
1228 return CompLevel_none;
1229 default:
1230 break;
1231 }
1232
1233 // Now handle the case of level 4.
1234 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1235 if (!training_has_profile) {
1236 // The method was a part of a level 4 compile, but don't have a stored profile,
1237 // we need to profile it.
1238 return CompLevel_full_profile;
1239 }
1240 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1241 // If we deopted, then we reprofile
1242 if (deopt && !is_method_profiled(method)) {
1243 return CompLevel_full_profile;
1244 }
1245
1246 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1247 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1248 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1249 if (SkipTier2IfPossible && ctd->init_deps_left() == 0) {
1250 if (method->method_data() == nullptr) {
1251 create_mdo(method, THREAD);
1252 }
1253 return CompLevel_full_optimization;
1254 }
1255
1256 // Otherwise go to level 2
1257 return CompLevel_limited_profile;
1258 }
1259
1260
1261 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1262 precond(mtd != nullptr);
1263 precond(cur_level == CompLevel_limited_profile);
1264
1265 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1266
1267 // But first, check if we have a saved profile
1268 bool training_has_profile = (mtd->final_profile() != nullptr);
1269 if (!training_has_profile) {
1270 return CompLevel_full_profile;
1271 }
1272
1273
1274 assert(training_has_profile, "Have to have a profile to be here");
1275 // Check if the method is ready
1276 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1277 if (ctd != nullptr && ctd->init_deps_left() == 0) {
1278 if (method->method_data() == nullptr) {
1279 create_mdo(method, THREAD);
1280 }
1281 return CompLevel_full_optimization;
1282 }
1283
1284 // Otherwise stay at the current level
1285 return CompLevel_limited_profile;
1286 }
1287
1288
1289 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1290 precond(mtd != nullptr);
1291 precond(cur_level == CompLevel_full_profile);
1292
1293 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1294 // We have method at the full profile level and we also know that it's possibly an important method.
1295 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1296 // Check if it is adequately profiled
1297 if (is_method_profiled(method)) {
1298 return CompLevel_full_optimization;
1299 }
1300 }
1301
1302 // Otherwise stay at the current level
1303 return CompLevel_full_profile;
1304 }
1305
1306 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1307 precond(MethodTrainingData::have_data());
1308
1309 // If there is no training data recorded for this method, bail out.
1310 if (mtd == nullptr) {
1311 return cur_level;
1312 }
1313
1314 CompLevel next_level = cur_level;
1315 switch(cur_level) {
1316 default: break;
1317 case CompLevel_none:
1318 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1319 break;
1320 case CompLevel_limited_profile:
1321 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1322 break;
1323 case CompLevel_full_profile:
1324 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1325 break;
1326 }
1327
1328 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1329 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1330 return CompLevel_none;
1331 }
1332 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1333 return CompLevel_none;
1334 }
1335 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1336 }
1337
1338 /*
1339 * Method states:
1340 * 0 - interpreter (CompLevel_none)
1341 * 1 - pure C1 (CompLevel_simple)
1342 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1343 * 3 - C1 with full profiling (CompLevel_full_profile)
1344 * 4 - C2 or Graal (CompLevel_full_optimization)
1345 *
1346 * Common state transition patterns:
1347 * a. 0 -> 3 -> 4.
1348 * The most common path. But note that even in this straightforward case
1349 * profiling can start at level 0 and finish at level 3.
1350 *
1351 * b. 0 -> 2 -> 3 -> 4.
1352 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1353 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1354 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1355 *
1356 * c. 0 -> (3->2) -> 4.
1357 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1358 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1359 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1360 * without full profiling while c2 is compiling.
1361 *
1362 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1363 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1364 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1365 *
1366 * e. 0 -> 4.
1367 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1368 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1369 * the compiled version already exists).
1370 *
1371 * Note that since state 0 can be reached from any other state via deoptimization different loops
1372 * are possible.
1373 *
1374 */
1375
1376 // Common transition function. Given a predicate determines if a method should transition to another level.
1377 template<typename Predicate>
1378 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1379 CompLevel next_level = cur_level;
1380
1381 if (force_comp_at_level_simple(method)) {
1382 next_level = CompLevel_simple;
1383 } else if (is_trivial(method) || method->is_native()) {
1384 // We do not care if there is profiling data for these methods, throw them to compiler.
1385 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1386 } else if (MethodTrainingData::have_data()) {
1387 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1388 if (mtd == nullptr) {
1389 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1390 // Feed it to the standard TF with no profiling delay.
1391 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1392 } else {
1393 next_level = trained_transition(method, cur_level, mtd, THREAD);
1394 if (cur_level == next_level) {
1395 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1396 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1397 // TF but with profiling delay.
1398 next_level = standard_transition<Predicate>(method, cur_level, true /*delay_profiling*/, disable_feedback);
1399 }
1400 }
1401 } else {
1402 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1403 }
1404 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1405 }
1406
1407
1408 template<typename Predicate>
1409 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1410 CompLevel next_level = cur_level;
1411 switch(cur_level) {
1412 default: break;
1413 case CompLevel_none:
1414 next_level = transition_from_none<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1415 break;
1416 case CompLevel_limited_profile:
1417 next_level = transition_from_limited_profile<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1418 break;
1419 case CompLevel_full_profile:
1420 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1421 break;
1422 }
1423 return next_level;
1424 }
1425
1426 template<typename Predicate>
1427 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1428 precond(cur_level == CompLevel_none);
1429 CompLevel next_level = cur_level;
1430 int i = method->invocation_count();
1431 int b = method->backedge_count();
1432 double scale = delay_profiling ? Tier0ProfileDelayFactor : 1.0;
1433 // If we were at full profile level, would we switch to full opt?
1434 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1435 next_level = CompLevel_full_optimization;
1436 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply_scaled(method, cur_level, i, b, scale)) {
1437 // C1-generated fully profiled code is about 30% slower than the limited profile
1438 // code that has only invocation and backedge counters. The observation is that
1439 // if C2 queue is large enough we can spend too much time in the fully profiled code
1440 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1441 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1442 // we choose to compile a limited profiled version and then recompile with full profiling
1443 // when the load on C2 goes down.
1444 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1445 next_level = CompLevel_limited_profile;
1446 } else {
1447 next_level = CompLevel_full_profile;
1448 }
1449 }
1450 return next_level;
1451 }
1452
1453 template<typename Predicate>
1454 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1455 precond(cur_level == CompLevel_full_profile);
1456 CompLevel next_level = cur_level;
1457 MethodData* mdo = method->method_data();
1458 if (mdo != nullptr) {
1459 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1460 int mdo_i = mdo->invocation_count_delta();
1461 int mdo_b = mdo->backedge_count_delta();
1462 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1463 next_level = CompLevel_full_optimization;
1464 }
1465 } else {
1466 next_level = CompLevel_full_optimization;
1467 }
1468 }
1469 return next_level;
1470 }
1471
1472 template<typename Predicate>
1473 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1474 precond(cur_level == CompLevel_limited_profile);
1475 CompLevel next_level = cur_level;
1476 int i = method->invocation_count();
1477 int b = method->backedge_count();
1478 double scale = delay_profiling ? Tier2ProfileDelayFactor : 1.0;
1479 MethodData* mdo = method->method_data();
1480 if (mdo != nullptr) {
1481 if (mdo->would_profile()) {
1482 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1483 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1484 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1485 next_level = CompLevel_full_profile;
1486 }
1487 } else {
1488 next_level = CompLevel_full_optimization;
1489 }
1490 } else {
1491 // If there is no MDO we need to profile
1492 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1493 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1494 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1495 next_level = CompLevel_full_profile;
1496 }
1497 }
1498 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1499 next_level = CompLevel_full_optimization;
1500 }
1501 return next_level;
1502 }
1503
1504
1505 // Determine if a method should be compiled with a normal entry point at a different level.
1506 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1507 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1508 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1509
1510 // If OSR method level is greater than the regular method level, the levels should be
1511 // equalized by raising the regular method level in order to avoid OSRs during each
1512 // invocation of the method.
1513 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1514 MethodData* mdo = method->method_data();
1515 guarantee(mdo != nullptr, "MDO should not be nullptr");
1516 if (mdo->invocation_count() >= 1) {
1517 next_level = CompLevel_full_optimization;
1518 }
1519 } else {
1520 next_level = MAX2(osr_level, next_level);
1521 }
1522 #if INCLUDE_JVMCI
1523 if (EnableJVMCI && UseJVMCICompiler &&
1524 next_level == CompLevel_full_optimization CDS_ONLY(&& !AOTLinkedClassBulkLoader::class_preloading_finished())) {
1525 next_level = cur_level;
1526 }
1527 #endif
1528 return next_level;
1529 }
1530
1531 // Determine if we should do an OSR compilation of a given method.
1532 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1533 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1534 if (cur_level == CompLevel_none) {
1535 // If there is a live OSR method that means that we deopted to the interpreter
1536 // for the transition.
1537 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1538 if (osr_level > CompLevel_none) {
1539 return osr_level;
1540 }
1541 }
1542 return next_level;
1543 }
1544
1545 // Handle the invocation event.
1546 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1547 CompLevel level, nmethod* nm, TRAPS) {
1548 if (should_create_mdo(mh, level)) {
1549 create_mdo(mh, THREAD);
1550 }
1551 CompLevel next_level = call_event(mh, level, THREAD);
1552 if (next_level != level) {
1553 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1554 compile(mh, InvocationEntryBci, next_level, THREAD);
1555 }
1556 }
1557 }
1558
1559 // Handle the back branch event. Notice that we can compile the method
1560 // with a regular entry from here.
1561 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1562 int bci, CompLevel level, nmethod* nm, TRAPS) {
1563 if (should_create_mdo(mh, level)) {
1564 create_mdo(mh, THREAD);
1565 }
1566 // Check if MDO should be created for the inlined method
1567 if (should_create_mdo(imh, level)) {
1568 create_mdo(imh, THREAD);
1569 }
1570
1571 if (is_compilation_enabled()) {
1572 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1573 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1574 // At the very least compile the OSR version
1575 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1576 compile(imh, bci, next_osr_level, CHECK);
1577 }
1578
1579 // Use loop event as an opportunity to also check if there's been
1580 // enough calls.
1581 CompLevel cur_level, next_level;
1582 if (mh() != imh()) { // If there is an enclosing method
1583 {
1584 guarantee(nm != nullptr, "Should have nmethod here");
1585 cur_level = comp_level(mh());
1586 next_level = call_event(mh, cur_level, THREAD);
1587
1588 if (max_osr_level == CompLevel_full_optimization) {
1589 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1590 bool make_not_entrant = false;
1591 if (nm->is_osr_method()) {
1592 // This is an osr method, just make it not entrant and recompile later if needed
1593 make_not_entrant = true;
1594 } else {
1595 if (next_level != CompLevel_full_optimization) {
1596 // next_level is not full opt, so we need to recompile the
1597 // enclosing method without the inlinee
1598 cur_level = CompLevel_none;
1599 make_not_entrant = true;
1600 }
1601 }
1602 if (make_not_entrant) {
1603 if (PrintTieredEvents) {
1604 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1605 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1606 }
1607 nm->make_not_entrant("OSR invalidation, back branch");
1608 }
1609 }
1610 // Fix up next_level if necessary to avoid deopts
1611 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1612 next_level = CompLevel_full_profile;
1613 }
1614 if (cur_level != next_level) {
1615 if (!CompileBroker::compilation_is_in_queue(mh)) {
1616 compile(mh, InvocationEntryBci, next_level, THREAD);
1617 }
1618 }
1619 }
1620 } else {
1621 cur_level = comp_level(mh());
1622 next_level = call_event(mh, cur_level, THREAD);
1623 if (next_level != cur_level) {
1624 if (!CompileBroker::compilation_is_in_queue(mh)) {
1625 compile(mh, InvocationEntryBci, next_level, THREAD);
1626 }
1627 }
1628 }
1629 }
1630 }
1631