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_acquire() > 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::compile_if_required(const methodHandle& m, TRAPS) {
138 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
139 // don't force compilation, resolve was on behalf of compiler
140 return;
141 }
142 if (m->method_holder()->is_not_initialized()) {
143 // 'is_not_initialized' means not only '!is_initialized', but also that
144 // initialization has not been started yet ('!being_initialized')
145 // Do not force compilation of methods in uninitialized classes.
146 // Note that doing this would throw an assert later,
147 // in CompileBroker::compile_method.
148 // We sometimes use the link resolver to do reflective lookups
149 // even before classes are initialized.
150 return;
151 }
152
153 if (must_be_compiled(m)) {
154 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
155 CompLevel level = initial_compile_level(m);
156 if (PrintTieredEvents) {
157 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
158 }
159 // Test AOT code too
160 bool requires_online_compilation = false;
161 if (TrainingData::have_data()) {
162 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
163 if (mtd != nullptr) {
164 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
165 if (ctd != nullptr) {
166 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
167 }
168 }
169 }
170 CompileBroker::compile_method(m, InvocationEntryBci, level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
171 }
172 }
173
174 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, JavaThread* current) {
175 if (!klass->has_init_deps_processed()) {
176 ResourceMark rm;
177 log_debug(training)("Replay training: %s", klass->external_name());
178
179 KlassTrainingData* ktd = KlassTrainingData::find(klass);
180 if (ktd != nullptr) {
181 guarantee(ktd->has_holder(), "");
182 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
183 assert(klass->has_init_deps_processed(), "");
184
185 if (AOTCompileEagerly) {
186 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
187 if (ctd->init_deps_left_acquire() == 0) {
188 MethodTrainingData* mtd = ctd->method();
189 if (mtd->has_holder()) {
190 const methodHandle mh(current, const_cast<Method*>(mtd->holder()));
191 CompilationPolicy::maybe_compile_early(mh, current);
192 }
193 }
194 });
195 }
196 }
197 }
198 }
199
200 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, JavaThread* current) {
201 assert(klass->is_initialized(), "");
202 if (TrainingData::have_data() && klass->in_aot_cache()) {
203 _training_replay_queue.push(klass, TrainingReplayQueue_lock, current);
204 }
205 }
206
207 // For TrainingReplayQueue
208 template<>
209 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
210 int pos = 0;
211 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
212 ResourceMark rm;
213 InstanceKlass* ik = cur->value();
214 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
215 }
216 }
217
218 void CompilationPolicy::replay_training_at_init_loop(JavaThread* current) {
219 while (!CompileBroker::is_compilation_disabled_forever()) {
220 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, current);
221 if (ik != nullptr) {
222 replay_training_at_init_impl(ik, current);
223 }
224 }
225 }
226
227 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
228 if (comp_level == CompLevel_any) {
229 if (CompilerConfig::is_c1_only()) {
230 comp_level = CompLevel_simple;
231 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
232 comp_level = CompLevel_full_optimization;
233 }
234 }
235 return comp_level;
236 }
237
238 // Returns true if m is allowed to be compiled
239 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
240 // allow any levels for WhiteBox
241 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
242
243 if (m->is_abstract()) return false;
244 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
245
246 // Math intrinsics should never be compiled as this can lead to
247 // monotonicity problems because the interpreter will prefer the
248 // compiled code to the intrinsic version. This can't happen in
249 // production because the invocation counter can't be incremented
250 // but we shouldn't expose the system to this problem in testing
251 // modes.
252 if (!AbstractInterpreter::can_be_compiled(m)) {
253 return false;
254 }
255 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
256 if (comp_level == CompLevel_any || is_compile(comp_level)) {
257 return !m->is_not_compilable(comp_level);
258 }
259 return false;
260 }
261
262 // Returns true if m is allowed to be osr compiled
263 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
264 bool result = false;
265 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
266 if (comp_level == CompLevel_any || is_compile(comp_level)) {
267 result = !m->is_not_osr_compilable(comp_level);
268 }
269 return (result && can_be_compiled(m, comp_level));
270 }
271
272 bool CompilationPolicy::is_compilation_enabled() {
273 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
274 return CompileBroker::should_compile_new_jobs();
275 }
276
277 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
278 // Remove unloaded methods from the queue
279 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
280 CompileTask* next = task->next();
281 if (task->is_unloaded()) {
282 compile_queue->remove_and_mark_stale(task);
283 }
284 task = next;
285 }
286 #if INCLUDE_JVMCI
287 if (UseJVMCICompiler && !BackgroundCompilation) {
288 /*
289 * In blocking compilation mode, the CompileBroker will make
290 * compilations submitted by a JVMCI compiler thread non-blocking. These
291 * compilations should be scheduled after all blocking compilations
292 * to service non-compiler related compilations sooner and reduce the
293 * chance of such compilations timing out.
294 */
295 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
296 if (task->is_blocking()) {
297 return task;
298 }
299 }
300 }
301 #endif
302 return compile_queue->first();
303 }
304
305 // Simple methods are as good being compiled with C1 as C2.
306 // Determine if a given method is such a case.
307 bool CompilationPolicy::is_trivial(const methodHandle& method) {
308 if (method->is_accessor() ||
309 method->is_constant_getter()) {
310 return true;
311 }
312 return false;
313 }
314
315 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
316 if (CompilationModeFlag::quick_internal()) {
317 #if INCLUDE_JVMCI
318 if (UseJVMCICompiler) {
319 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
320 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
321 return true;
322 }
323 }
324 #endif
325 }
326 return false;
327 }
328
329 CompLevel CompilationPolicy::comp_level(Method* method) {
330 nmethod *nm = method->code();
331 if (nm != nullptr && nm->is_in_use()) {
332 return (CompLevel)nm->comp_level();
333 }
334 return CompLevel_none;
335 }
336
337 // Call and loop predicates determine whether a transition to a higher
338 // compilation level should be performed (pointers to predicate functions
339 // are passed to common()).
340 // Tier?LoadFeedback is basically a coefficient that determines of
341 // how many methods per compiler thread can be in the queue before
342 // the threshold values double.
343 class LoopPredicate : AllStatic {
344 public:
345 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
346 double threshold_scaling;
347 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
348 scale *= threshold_scaling;
349 }
350 switch(cur_level) {
351 case CompLevel_none:
352 case CompLevel_limited_profile:
353 return b >= Tier3BackEdgeThreshold * scale;
354 case CompLevel_full_profile:
355 return b >= Tier4BackEdgeThreshold * scale;
356 default:
357 return true;
358 }
359 }
360
361 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
362 double k = 1;
363 switch(cur_level) {
364 case CompLevel_none:
365 // Fall through
366 case CompLevel_limited_profile: {
367 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
368 break;
369 }
370 case CompLevel_full_profile: {
371 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
372 break;
373 }
374 default:
375 return true;
376 }
377 return apply_scaled(method, cur_level, i, b, k);
378 }
379 };
380
381 class CallPredicate : AllStatic {
382 public:
383 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
384 double threshold_scaling;
385 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
386 scale *= threshold_scaling;
387 }
388 switch(cur_level) {
389 case CompLevel_none:
390 case CompLevel_limited_profile:
391 return (i >= Tier3InvocationThreshold * scale) ||
392 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
393 case CompLevel_full_profile:
394 return (i >= Tier4InvocationThreshold * scale) ||
395 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
396 default:
397 return true;
398 }
399 }
400
401 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
402 double k = 1;
403 switch(cur_level) {
404 case CompLevel_none:
405 case CompLevel_limited_profile: {
406 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
407 break;
408 }
409 case CompLevel_full_profile: {
410 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
411 break;
412 }
413 default:
414 return true;
415 }
416 return apply_scaled(method, cur_level, i, b, k);
417 }
418 };
419
420 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
421 int comp_count = compiler_count(level);
422 if (comp_count > 0 && feedback_k > 0) {
423 double queue_size = CompileBroker::queue_size(level);
424 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
425
426 // Increase C1 compile threshold when the code cache is filled more
427 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
428 // The main intention is to keep enough free space for C2 compiled code
429 // to achieve peak performance if the code cache is under stress.
430 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
431 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
432 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
433 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
434 }
435 }
436 return k;
437 }
438 return 1;
439 }
440
441 void CompilationPolicy::print_counters_on(outputStream* st, const char* prefix, Method* m) {
442 int invocation_count = m->invocation_count();
443 int backedge_count = m->backedge_count();
444 MethodData* mdh = m->method_data();
445 int mdo_invocations = 0, mdo_backedges = 0;
446 int mdo_invocations_start = 0, mdo_backedges_start = 0;
447 if (mdh != nullptr) {
448 mdo_invocations = mdh->invocation_count();
449 mdo_backedges = mdh->backedge_count();
450 mdo_invocations_start = mdh->invocation_count_start();
451 mdo_backedges_start = mdh->backedge_count_start();
452 }
453 st->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
454 invocation_count, backedge_count, prefix,
455 mdo_invocations, mdo_invocations_start,
456 mdo_backedges, mdo_backedges_start);
457 st->print(" %smax levels=%d,%d", prefix, m->highest_comp_level(), m->highest_osr_comp_level());
458 }
459
460 void CompilationPolicy::print_training_data_on(outputStream* st, const char* prefix, Method* method) {
461 methodHandle m(Thread::current(), method);
462 st->print(" %smtd: ", prefix);
463 MethodTrainingData* mtd = MethodTrainingData::find(m);
464 if (mtd == nullptr) {
465 st->print("null");
466 } else {
467 MethodData* md = mtd->final_profile();
468 st->print("mdo=");
469 if (md == nullptr) {
470 st->print("null");
471 } else {
472 int mdo_invocations = md->invocation_count();
473 int mdo_backedges = md->backedge_count();
474 int mdo_invocations_start = md->invocation_count_start();
475 int mdo_backedges_start = md->backedge_count_start();
476 st->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
477 }
478 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
479 st->print(", deps=");
480 if (ctd == nullptr) {
481 st->print("null");
482 } else {
483 st->print("%d", ctd->init_deps_left_acquire());
484 }
485 }
486 }
487
488 // Print an event.
489 void CompilationPolicy::print_event_on(outputStream *st, EventType type, Method* m, Method* im, int bci, CompLevel level) {
490 bool inlinee_event = m != im;
491
492 st->print("%lf: [", os::elapsedTime());
493
494 switch(type) {
495 case CALL:
496 st->print("call");
497 break;
498 case LOOP:
499 st->print("loop");
500 break;
501 case COMPILE:
502 st->print("compile");
503 break;
504 case FORCE_COMPILE:
505 st->print("force-compile");
506 break;
507 case FORCE_RECOMPILE:
508 st->print("force-recompile");
509 break;
510 case REMOVE_FROM_QUEUE:
511 st->print("remove-from-queue");
512 break;
513 case UPDATE_IN_QUEUE:
514 st->print("update-in-queue");
515 break;
516 case REPROFILE:
517 st->print("reprofile");
518 break;
519 case MAKE_NOT_ENTRANT:
520 st->print("make-not-entrant");
521 break;
522 default:
523 st->print("unknown");
524 }
525
526 st->print(" level=%d ", level);
527
528 ResourceMark rm;
529 char *method_name = m->name_and_sig_as_C_string();
530 st->print("[%s", method_name);
531 if (inlinee_event) {
532 char *inlinee_name = im->name_and_sig_as_C_string();
533 st->print(" [%s]] ", inlinee_name);
534 }
535 else st->print("] ");
536 st->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
537 CompileBroker::queue_size(CompLevel_full_optimization));
538
539 st->print(" rate=");
540 if (m->prev_time() == 0) st->print("n/a");
541 else st->print("%f", m->rate());
542
543 RecompilationPolicy::print_load_average(st);
544
545 st->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
546 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
547
548 if (type != COMPILE) {
549 print_counters_on(st, "", m);
550 if (inlinee_event) {
551 print_counters_on(st, "inlinee ", im);
552 }
553 st->print(" compilable=");
554 bool need_comma = false;
555 if (!m->is_not_compilable(CompLevel_full_profile)) {
556 st->print("c1");
557 need_comma = true;
558 }
559 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
560 if (need_comma) st->print(",");
561 st->print("c1-osr");
562 need_comma = true;
563 }
564 if (!m->is_not_compilable(CompLevel_full_optimization)) {
565 if (need_comma) st->print(",");
566 st->print("c2");
567 need_comma = true;
568 }
569 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
570 if (need_comma) st->print(",");
571 st->print("c2-osr");
572 }
573 st->print(" status=");
574 if (m->queued_for_compilation()) {
575 st->print("in-queue");
576 } else st->print("idle");
577
578 print_training_data_on(st, "", m);
579 if (inlinee_event) {
580 print_training_data_on(st, "inlinee ", im);
581 }
582 }
583 st->print_cr("]");
584
585 }
586
587 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
588 stringStream s;
589 print_event_on(&s, type, m, im, bci, level);
590 ResourceMark rm;
591 tty->print("%s", s.as_string());
592 }
593
594 void CompilationPolicy::initialize() {
595 if (!CompilerConfig::is_interpreter_only()) {
596 int count = CICompilerCount;
597 bool c1_only = CompilerConfig::is_c1_only();
598 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
599 int min_count = (c1_only || c2_only) ? 1 : 2;
600
601 #ifdef _LP64
602 // Turn on ergonomic compiler count selection
603 if (AOTCodeCache::maybe_dumping_code()) {
604 // Assembly phase runs C1 and C2 compilation in separate phases,
605 // and can use all the CPU threads it can reach. Adjust the common
606 // options before policy starts overwriting them.
607 FLAG_SET_ERGO_IF_DEFAULT(UseDynamicNumberOfCompilerThreads, false);
608 FLAG_SET_ERGO_IF_DEFAULT(CICompilerCountPerCPU, false);
609 if (FLAG_IS_DEFAULT(CICompilerCount)) {
610 count = MAX2(count, os::active_processor_count());
611 }
612 }
613 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
614 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
615 }
616 if (CICompilerCountPerCPU) {
617 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
618 int log_cpu = log2i(os::active_processor_count());
619 int loglog_cpu = log2i(MAX2(log_cpu, 1));
620 count = MAX2(log_cpu * loglog_cpu * 3 / 2, min_count);
621 }
622 if (FLAG_IS_DEFAULT(CICompilerCount)) {
623 // Make sure there is enough space in the code cache to hold all the compiler buffers
624 size_t c1_size = 0;
625 #ifdef COMPILER1
626 c1_size = Compiler::code_buffer_size();
627 #endif
628 size_t c2_size = 0;
629 #ifdef COMPILER2
630 c2_size = C2Compiler::initial_code_buffer_size();
631 #endif
632 size_t buffer_size = 0;
633 if (c1_only) {
634 buffer_size = c1_size;
635 } else if (c2_only) {
636 buffer_size = c2_size;
637 } else {
638 buffer_size = c1_size / 3 + 2 * c2_size / 3;
639 }
640 size_t max_count = (NonNMethodCodeHeapSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / buffer_size;
641 if ((size_t)count > max_count) {
642 // Lower the compiler count such that all buffers fit into the code cache
643 count = MAX2((int)max_count, min_count);
644 }
645 FLAG_SET_ERGO(CICompilerCount, count);
646 }
647 #else
648 // On 32-bit systems, the number of compiler threads is limited to 3.
649 // On these systems, the virtual address space available to the JVM
650 // is usually limited to 2-4 GB (the exact value depends on the platform).
651 // As the compilers (especially C2) can consume a large amount of
652 // memory, scaling the number of compiler threads with the number of
653 // available cores can result in the exhaustion of the address space
654 /// available to the VM and thus cause the VM to crash.
655 if (FLAG_IS_DEFAULT(CICompilerCount)) {
656 count = 3;
657 FLAG_SET_ERGO(CICompilerCount, count);
658 }
659 #endif // _LP64
660
661 if (c1_only) {
662 // No C2 compiler threads are needed
663 set_c1_count(count);
664 } else if (c2_only) {
665 // No C1 compiler threads are needed
666 set_c2_count(count);
667 } else {
668 #if INCLUDE_JVMCI
669 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
670 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
671 int c1_count = MAX2(count - libjvmci_count, 1);
672 set_c2_count(libjvmci_count);
673 set_c1_count(c1_count);
674 } else
675 #endif
676 {
677 set_c1_count(MAX2(count / 3, 1));
678 set_c2_count(MAX2(count - c1_count(), 1));
679 }
680 }
681 if (AOTCodeCache::is_code_load_thread_on()) {
682 set_ac_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 AOT code in parallel
683 }
684 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
685 set_increase_threshold_at_ratio();
686 } else {
687 // Interpreter mode creates no compilers
688 FLAG_SET_ERGO(CICompilerCount, 0);
689 }
690 set_start_time(nanos_to_millis(os::javaTimeNanos()));
691 }
692
693
694 #ifdef ASSERT
695 bool CompilationPolicy::verify_level(CompLevel level) {
696 if (TieredCompilation && level > TieredStopAtLevel) {
697 return false;
698 }
699 // Check if there is a compiler to process the requested level
700 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
701 return false;
702 }
703 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
704 return false;
705 }
706
707 // Interpreter level is always valid.
708 if (level == CompLevel_none) {
709 return true;
710 }
711 if (CompilationModeFlag::normal()) {
712 return true;
713 } else if (CompilationModeFlag::quick_only()) {
714 return level == CompLevel_simple;
715 } else if (CompilationModeFlag::high_only()) {
716 return level == CompLevel_full_optimization;
717 } else if (CompilationModeFlag::high_only_quick_internal()) {
718 return level == CompLevel_full_optimization || level == CompLevel_simple;
719 }
720 return false;
721 }
722 #endif
723
724
725 CompLevel CompilationPolicy::highest_compile_level() {
726 CompLevel level = CompLevel_none;
727 // Setup the maximum level available for the current compiler configuration.
728 if (!CompilerConfig::is_interpreter_only()) {
729 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
730 level = CompLevel_full_optimization;
731 } else if (CompilerConfig::is_c1_enabled()) {
732 if (CompilerConfig::is_c1_simple_only()) {
733 level = CompLevel_simple;
734 } else {
735 level = CompLevel_full_profile;
736 }
737 }
738 }
739 // Clamp the maximum level with TieredStopAtLevel.
740 if (TieredCompilation) {
741 level = MIN2(level, (CompLevel) TieredStopAtLevel);
742 }
743
744 // Fix it up if after the clamping it has become invalid.
745 // Bring it monotonically down depending on the next available level for
746 // the compilation mode.
747 if (!CompilationModeFlag::normal()) {
748 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
749 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
750 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
751 if (CompilationModeFlag::quick_only()) {
752 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
753 level = CompLevel_simple;
754 }
755 } else if (CompilationModeFlag::high_only()) {
756 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
757 level = CompLevel_none;
758 }
759 } else if (CompilationModeFlag::high_only_quick_internal()) {
760 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
761 level = CompLevel_simple;
762 }
763 }
764 }
765
766 assert(verify_level(level), "Invalid highest compilation level: %d", level);
767 return level;
768 }
769
770 CompLevel CompilationPolicy::limit_level(CompLevel level) {
771 level = MIN2(level, highest_compile_level());
772 assert(verify_level(level), "Invalid compilation level: %d", level);
773 return level;
774 }
775
776 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
777 CompLevel level = CompLevel_any;
778 if (CompilationModeFlag::normal()) {
779 level = CompLevel_full_profile;
780 } else if (CompilationModeFlag::quick_only()) {
781 level = CompLevel_simple;
782 } else if (CompilationModeFlag::high_only()) {
783 level = CompLevel_full_optimization;
784 } else if (CompilationModeFlag::high_only_quick_internal()) {
785 if (force_comp_at_level_simple(method)) {
786 level = CompLevel_simple;
787 } else {
788 level = CompLevel_full_optimization;
789 }
790 }
791 assert(level != CompLevel_any, "Unhandled compilation mode");
792 return limit_level(level);
793 }
794
795 // Set carry flags on the counters if necessary
796 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
797 MethodCounters *mcs = method->method_counters();
798 if (mcs != nullptr) {
799 mcs->invocation_counter()->set_carry_on_overflow();
800 mcs->backedge_counter()->set_carry_on_overflow();
801 }
802 MethodData* mdo = method->method_data();
803 if (mdo != nullptr) {
804 mdo->invocation_counter()->set_carry_on_overflow();
805 mdo->backedge_counter()->set_carry_on_overflow();
806 }
807 }
808
809 // Called with the queue locked and with at least one element
810 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
811 CompileTask *max_blocking_task = nullptr;
812 CompileTask *max_task = nullptr;
813 Method* max_method = nullptr;
814
815 int64_t t = nanos_to_millis(os::javaTimeNanos());
816 // Iterate through the queue and find a method with a maximum rate.
817 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
818 CompileTask* next_task = task->next();
819 // If a method was unloaded or has been stale for some time, remove it from the queue.
820 // Blocking tasks and tasks submitted from whitebox API don't become stale
821 if (task->is_unloaded()) {
822 compile_queue->remove_and_mark_stale(task);
823 task = next_task;
824 continue;
825 }
826 if (task->is_aot_load()) {
827 // AOTCodeCache tasks are on separate queue, and they should load fast. There is no need to walk
828 // the rest of the queue, just take the task and go.
829 return task;
830 }
831 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
832 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
833 // selection and/or any level adjustments. Just return them in order.
834 return task;
835 }
836 Method* method = task->method();
837 methodHandle mh(THREAD, method);
838 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
839 if (PrintTieredEvents) {
840 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
841 }
842 method->clear_queued_for_compilation();
843 method->set_pending_queue_processed(false);
844 compile_queue->remove_and_mark_stale(task);
845 task = next_task;
846 continue;
847 }
848 update_rate(t, mh);
849 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
850 // Select a method with the highest rate
851 max_task = task;
852 max_method = method;
853 }
854
855 if (task->is_blocking()) {
856 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
857 max_blocking_task = task;
858 }
859 }
860
861 task = next_task;
862 }
863
864 if (max_blocking_task != nullptr) {
865 // In blocking compilation mode, the CompileBroker will make
866 // compilations submitted by a JVMCI compiler thread non-blocking. These
867 // compilations should be scheduled after all blocking compilations
868 // to service non-compiler related compilations sooner and reduce the
869 // chance of such compilations timing out.
870 max_task = max_blocking_task;
871 max_method = max_task->method();
872 }
873
874 methodHandle max_method_h(THREAD, max_method);
875
876 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
877 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
878 max_task->set_comp_level(CompLevel_limited_profile);
879
880 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
881 false /* requires_online_compilation */,
882 CompileTask::Reason_None)) {
883 if (PrintTieredEvents) {
884 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
885 }
886 compile_queue->remove_and_mark_stale(max_task);
887 max_method->clear_queued_for_compilation();
888 return nullptr;
889 }
890
891 if (PrintTieredEvents) {
892 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
893 }
894 }
895
896 return max_task;
897 }
898
899 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
900 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
901 if (PrintTieredEvents) {
902 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
903 }
904 MethodData* mdo = sd->method()->method_data();
905 if (mdo != nullptr) {
906 mdo->reset_start_counters();
907 }
908 if (sd->is_top()) break;
909 }
910 }
911
912 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
913 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
914 if (PrintTieredEvents) {
915 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
916 }
917
918 if (comp_level == CompLevel_none &&
919 JvmtiExport::can_post_interpreter_events() &&
920 THREAD->is_interp_only_mode()) {
921 return nullptr;
922 }
923 if (ReplayCompiles) {
924 // Don't trigger other compiles in testing mode
925 return nullptr;
926 }
927
928 handle_counter_overflow(method);
929 if (method() != inlinee()) {
930 handle_counter_overflow(inlinee);
931 }
932
933 if (bci == InvocationEntryBci) {
934 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
935 } else {
936 // method == inlinee if the event originated in the main method
937 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
938 // Check if event led to a higher level OSR compilation
939 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
940 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
941 // It's not possible to reach the expected level so fall back to simple.
942 expected_comp_level = CompLevel_simple;
943 }
944 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
945 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
946 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
947 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
948 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
949 // Perform OSR with new nmethod
950 return osr_nm;
951 }
952 }
953 }
954 return nullptr;
955 }
956
957 // Check if the method can be compiled, change level if necessary
958 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
959 assert(verify_level(level), "Invalid compilation level requested: %d", level);
960
961 if (level == CompLevel_none) {
962 if (mh->has_compiled_code()) {
963 // Happens when we switch to interpreter to profile.
964 MutexLocker ml(Compile_lock);
965 NoSafepointVerifier nsv;
966 if (mh->has_compiled_code()) {
967 mh->code()->make_not_used();
968 }
969 // Deoptimize immediately (we don't have to wait for a compile).
970 JavaThread* jt = THREAD;
971 RegisterMap map(jt,
972 RegisterMap::UpdateMap::skip,
973 RegisterMap::ProcessFrames::include,
974 RegisterMap::WalkContinuation::skip);
975 frame fr = jt->last_frame().sender(&map);
976 Deoptimization::deoptimize_frame(jt, fr.id());
977 }
978 return;
979 }
980
981 // Check if the method can be compiled. Additional logic for TieredCompilation:
982 // If it cannot be compiled with C1, continue profiling in the interpreter
983 // and then compile with C2 (the transition function will request that,
984 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
985 // pure C1.
986 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
987 if (!CompilationModeFlag::disable_intermediate() &&
988 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 (!CompilationModeFlag::disable_intermediate() &&
995 level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
996 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
997 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
998 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
999 osr_nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_FOR_COMPILING_WITH_C1);
1000 }
1001 compile(mh, bci, CompLevel_simple, THREAD);
1002 }
1003 return;
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_acquire() > 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_acquire() == 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_acquire() == 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> static inline bool apply_predicate(const methodHandle& method, CompLevel cur_level, int i, int b, bool delay_profiling, double delay_profiling_scale) {
1427 if (delay_profiling) {
1428 return Predicate::apply_scaled(method, cur_level, i, b, delay_profiling_scale);
1429 } else {
1430 return Predicate::apply(method, cur_level, i, b);
1431 }
1432 }
1433
1434 template<typename Predicate>
1435 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1436 precond(cur_level == CompLevel_none);
1437 CompLevel next_level = cur_level;
1438 int i = method->invocation_count();
1439 int b = method->backedge_count();
1440 // If we were at full profile level, would we switch to full opt?
1441 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1442 next_level = CompLevel_full_optimization;
1443 } else if (!CompilationModeFlag::disable_intermediate() && apply_predicate<Predicate>(method, cur_level, i, b, delay_profiling, Tier0ProfileDelayFactor)) {
1444 // C1-generated fully profiled code is about 30% slower than the limited profile
1445 // code that has only invocation and backedge counters. The observation is that
1446 // if C2 queue is large enough we can spend too much time in the fully profiled code
1447 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1448 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1449 // we choose to compile a limited profiled version and then recompile with full profiling
1450 // when the load on C2 goes down.
1451 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1452 next_level = CompLevel_limited_profile;
1453 } else {
1454 next_level = CompLevel_full_profile;
1455 }
1456 }
1457 return next_level;
1458 }
1459
1460 template<typename Predicate>
1461 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1462 precond(cur_level == CompLevel_full_profile);
1463 CompLevel next_level = cur_level;
1464 MethodData* mdo = method->method_data();
1465 if (mdo != nullptr) {
1466 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1467 int mdo_i = mdo->invocation_count_delta();
1468 int mdo_b = mdo->backedge_count_delta();
1469 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1470 next_level = CompLevel_full_optimization;
1471 }
1472 } else {
1473 next_level = CompLevel_full_optimization;
1474 }
1475 }
1476 return next_level;
1477 }
1478
1479 template<typename Predicate>
1480 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1481 precond(cur_level == CompLevel_limited_profile);
1482 CompLevel next_level = cur_level;
1483 int i = method->invocation_count();
1484 int b = method->backedge_count();
1485 MethodData* mdo = method->method_data();
1486 if (mdo != nullptr) {
1487 if (mdo->would_profile()) {
1488 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1489 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1490 apply_predicate<Predicate>(method, cur_level, i, b, delay_profiling, Tier2ProfileDelayFactor))) {
1491 next_level = CompLevel_full_profile;
1492 }
1493 } else {
1494 next_level = CompLevel_full_optimization;
1495 }
1496 } else {
1497 // If there is no MDO we need to profile
1498 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1499 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1500 apply_predicate<Predicate>(method, cur_level, i, b, delay_profiling, Tier2ProfileDelayFactor))) {
1501 next_level = CompLevel_full_profile;
1502 }
1503 }
1504 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1505 next_level = CompLevel_full_optimization;
1506 }
1507 return next_level;
1508 }
1509
1510
1511 // Determine if a method should be compiled with a normal entry point at a different level.
1512 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1513 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1514 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1515
1516 // If OSR method level is greater than the regular method level, the levels should be
1517 // equalized by raising the regular method level in order to avoid OSRs during each
1518 // invocation of the method.
1519 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1520 MethodData* mdo = method->method_data();
1521 guarantee(mdo != nullptr, "MDO should not be nullptr");
1522 if (mdo->invocation_count() >= 1) {
1523 next_level = CompLevel_full_optimization;
1524 }
1525 } else {
1526 next_level = MAX2(osr_level, next_level);
1527 }
1528
1529 return next_level;
1530 }
1531
1532 // Determine if we should do an OSR compilation of a given method.
1533 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1534 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1535 if (cur_level == CompLevel_none) {
1536 // If there is a live OSR method that means that we deopted to the interpreter
1537 // for the transition.
1538 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1539 if (osr_level > CompLevel_none) {
1540 return osr_level;
1541 }
1542 }
1543 return next_level;
1544 }
1545
1546 // Handle the invocation event.
1547 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1548 CompLevel level, nmethod* nm, TRAPS) {
1549 if (should_create_mdo(mh, level)) {
1550 create_mdo(mh, THREAD);
1551 }
1552 CompLevel next_level = call_event(mh, level, THREAD);
1553 if (next_level != level) {
1554 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1555 compile(mh, InvocationEntryBci, next_level, THREAD);
1556 }
1557 }
1558 }
1559
1560 // Handle the back branch event. Notice that we can compile the method
1561 // with a regular entry from here.
1562 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1563 int bci, CompLevel level, nmethod* nm, TRAPS) {
1564 if (should_create_mdo(mh, level)) {
1565 create_mdo(mh, THREAD);
1566 }
1567 // Check if MDO should be created for the inlined method
1568 if (should_create_mdo(imh, level)) {
1569 create_mdo(imh, THREAD);
1570 }
1571
1572 if (is_compilation_enabled()) {
1573 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1574 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1575 // At the very least compile the OSR version
1576 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1577 compile(imh, bci, next_osr_level, CHECK);
1578 }
1579
1580 // Use loop event as an opportunity to also check if there's been
1581 // enough calls.
1582 CompLevel cur_level, next_level;
1583 if (mh() != imh()) { // If there is an enclosing method
1584 {
1585 guarantee(nm != nullptr, "Should have nmethod here");
1586 cur_level = comp_level(mh());
1587 next_level = call_event(mh, cur_level, THREAD);
1588
1589 if (max_osr_level == CompLevel_full_optimization) {
1590 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1591 bool make_not_entrant = false;
1592 if (nm->is_osr_method()) {
1593 // This is an osr method, just make it not entrant and recompile later if needed
1594 make_not_entrant = true;
1595 } else {
1596 if (next_level != CompLevel_full_optimization) {
1597 // next_level is not full opt, so we need to recompile the
1598 // enclosing method without the inlinee
1599 cur_level = CompLevel_none;
1600 make_not_entrant = true;
1601 }
1602 }
1603 if (make_not_entrant) {
1604 if (PrintTieredEvents) {
1605 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1606 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1607 }
1608 nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_BACK_BRANCH);
1609 }
1610 }
1611 // Fix up next_level if necessary to avoid deopts
1612 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1613 next_level = CompLevel_full_profile;
1614 }
1615 if (cur_level != next_level) {
1616 if (!CompileBroker::compilation_is_in_queue(mh)) {
1617 compile(mh, InvocationEntryBci, next_level, THREAD);
1618 }
1619 }
1620 }
1621 } else {
1622 cur_level = comp_level(mh());
1623 next_level = call_event(mh, cur_level, THREAD);
1624 if (next_level != cur_level) {
1625 if (!CompileBroker::compilation_is_in_queue(mh)) {
1626 compile(mh, InvocationEntryBci, next_level, THREAD);
1627 }
1628 }
1629 }
1630 }
1631 }
1632