1 /*
2 * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotLinkedClassBulkLoader.hpp"
26 #include "code/scopeDesc.hpp"
27 #include "code/SCCache.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/methodData.hpp"
35 #include "oops/method.inline.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::_c3_count = 0;
61 int CompilationPolicy::_sc_count = 0;
62 double CompilationPolicy::_increase_threshold_at_ratio = 0;
63
64 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
65
66 void compilationPolicy_init() {
67 CompilationPolicy::initialize();
68 }
69
70 int CompilationPolicy::compiler_count(CompLevel comp_level) {
71 if (is_c1_compile(comp_level)) {
72 return c1_count();
73 } else if (is_c2_compile(comp_level)) {
74 return c2_count();
75 }
76 return 0;
77 }
78
79 // Returns true if m must be compiled before executing it
80 // This is intended to force compiles for methods (usually for
81 // debugging) that would otherwise be interpreted for some reason.
82 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
83 // Don't allow Xcomp to cause compiles in replay mode
84 if (ReplayCompiles) return false;
85
86 if (m->has_compiled_code()) return false; // already compiled
87 if (!can_be_compiled(m, comp_level)) return false;
88
89 return !UseInterpreter || // must compile all methods
90 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
91 }
92
93 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
94 if (m->method_holder()->is_not_initialized()) {
95 // 'is_not_initialized' means not only '!is_initialized', but also that
96 // initialization has not been started yet ('!being_initialized')
97 // Do not force compilation of methods in uninitialized classes.
98 return;
99 }
100 if (!m->is_native() && MethodTrainingData::have_data()) {
101 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
102 if (mtd == nullptr) {
103 return; // there is no training data recorded for m
104 }
105 bool recompile = m->code_has_clinit_barriers();
106 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
107 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
108 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
109 bool requires_online_compilation = false;
110 CompileTrainingData* ctd = mtd->last_toplevel_compile(next_level);
111 if (ctd != nullptr) {
112 requires_online_compilation = (ctd->init_deps_left() > 0);
113 }
114 if (requires_online_compilation && recompile) {
115 return;
116 }
117 if (PrintTieredEvents) {
118 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
119 }
120 CompileBroker::compile_method(m, InvocationEntryBci, next_level, methodHandle(), 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
121 if (HAS_PENDING_EXCEPTION) {
122 CLEAR_PENDING_EXCEPTION;
123 }
124 }
125 }
126 }
127
128 void CompilationPolicy::maybe_compile_early_after_init(const methodHandle& m, TRAPS) {
129 assert(m->method_holder()->is_initialized(), "Should be called after class initialization");
130 maybe_compile_early(m, THREAD);
131 }
132
133 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
134 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
135 // don't force compilation, resolve was on behalf of compiler
136 return;
137 }
138 if (m->method_holder()->is_not_initialized()) {
139 // 'is_not_initialized' means not only '!is_initialized', but also that
140 // initialization has not been started yet ('!being_initialized')
141 // Do not force compilation of methods in uninitialized classes.
142 // Note that doing this would throw an assert later,
143 // in CompileBroker::compile_method.
144 // We sometimes use the link resolver to do reflective lookups
145 // even before classes are initialized.
146 return;
147 }
148
149 if (must_be_compiled(m)) {
150 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
151 CompLevel level = initial_compile_level(m);
152 if (PrintTieredEvents) {
153 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
154 }
155 CompileBroker::compile_method(m, InvocationEntryBci, level, methodHandle(), 0, false, CompileTask::Reason_MustBeCompiled, THREAD);
156 }
157 }
158
159 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, TRAPS) {
160 if (!klass->has_init_deps_processed()) {
161 ResourceMark rm;
162 log_debug(training)("Replay training: %s", klass->external_name());
163
164 KlassTrainingData* ktd = KlassTrainingData::find(klass);
165 if (ktd != nullptr) {
166 guarantee(ktd->has_holder(), "");
167 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
168 assert(klass->has_init_deps_processed(), "");
169
170 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
171 if (ctd->init_deps_left() == 0) {
172 MethodTrainingData* mtd = ctd->method();
173 if (mtd->has_holder()) {
174 const methodHandle mh(THREAD, const_cast<Method*>(mtd->holder()));
175 CompilationPolicy::maybe_compile_early(mh, THREAD);
176 }
177 }
178 });
179 }
180 }
181 }
182
183 void CompilationPolicy::flush_replay_training_at_init(TRAPS) {
184 MonitorLocker locker(THREAD, TrainingReplayQueue_lock);
185 while (!_training_replay_queue.is_empty_unlocked()) {
186 locker.wait(); // let the replay training thread drain the queue
187 }
188 }
189
190 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, TRAPS) {
191 assert(klass->is_initialized(), "");
192 if (TrainingData::have_data() && klass->is_shared()) {
193 _training_replay_queue.push(klass, TrainingReplayQueue_lock, THREAD);
194 }
195 }
196
197 // For TrainingReplayQueue
198 template<>
199 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
200 int pos = 0;
201 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
202 ResourceMark rm;
203 InstanceKlass* ik = cur->value();
204 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
205 }
206 }
207
208 void CompilationPolicy::replay_training_at_init_loop(TRAPS) {
209 while (!CompileBroker::is_compilation_disabled_forever() || VerifyTrainingData) {
210 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, THREAD);
211 replay_training_at_init_impl(ik, THREAD);
212 }
213 }
214
215 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
216 if (comp_level == CompLevel_any) {
217 if (CompilerConfig::is_c1_only()) {
218 comp_level = CompLevel_simple;
219 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
220 comp_level = CompLevel_full_optimization;
221 }
222 }
223 return comp_level;
224 }
225
226 // Returns true if m is allowed to be compiled
227 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
228 // allow any levels for WhiteBox
229 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
230
231 if (m->is_abstract()) return false;
232 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
233
234 // Math intrinsics should never be compiled as this can lead to
235 // monotonicity problems because the interpreter will prefer the
236 // compiled code to the intrinsic version. This can't happen in
237 // production because the invocation counter can't be incremented
238 // but we shouldn't expose the system to this problem in testing
239 // modes.
240 if (!AbstractInterpreter::can_be_compiled(m)) {
241 return false;
242 }
243 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
244 if (comp_level == CompLevel_any || is_compile(comp_level)) {
245 return !m->is_not_compilable(comp_level);
246 }
247 return false;
248 }
249
250 // Returns true if m is allowed to be osr compiled
251 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
252 bool result = false;
253 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
254 if (comp_level == CompLevel_any || is_compile(comp_level)) {
255 result = !m->is_not_osr_compilable(comp_level);
256 }
257 return (result && can_be_compiled(m, comp_level));
258 }
259
260 bool CompilationPolicy::is_compilation_enabled() {
261 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
262 return CompileBroker::should_compile_new_jobs();
263 }
264
265 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
266 // Remove unloaded methods from the queue
267 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
268 CompileTask* next = task->next();
269 if (task->is_unloaded()) {
270 compile_queue->remove_and_mark_stale(task);
271 }
272 task = next;
273 }
274 #if INCLUDE_JVMCI
275 if (UseJVMCICompiler && !BackgroundCompilation) {
276 /*
277 * In blocking compilation mode, the CompileBroker will make
278 * compilations submitted by a JVMCI compiler thread non-blocking. These
279 * compilations should be scheduled after all blocking compilations
280 * to service non-compiler related compilations sooner and reduce the
281 * chance of such compilations timing out.
282 */
283 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
284 if (task->is_blocking()) {
285 return task;
286 }
287 }
288 }
289 #endif
290 return compile_queue->first();
291 }
292
293 // Simple methods are as good being compiled with C1 as C2.
294 // Determine if a given method is such a case.
295 bool CompilationPolicy::is_trivial(const methodHandle& method) {
296 if (method->is_accessor() ||
297 method->is_constant_getter()) {
298 return true;
299 }
300 return false;
301 }
302
303 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
304 if (CompilationModeFlag::quick_internal()) {
305 #if INCLUDE_JVMCI
306 if (UseJVMCICompiler) {
307 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
308 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
309 return !SCCache::is_C3_on();
310 }
311 }
312 #endif
313 }
314 return false;
315 }
316
317 CompLevel CompilationPolicy::comp_level(Method* method) {
318 nmethod *nm = method->code();
319 if (nm != nullptr && nm->is_in_use()) {
320 return (CompLevel)nm->comp_level();
321 }
322 return CompLevel_none;
323 }
324
325 // Call and loop predicates determine whether a transition to a higher
326 // compilation level should be performed (pointers to predicate functions
327 // are passed to common()).
328 // Tier?LoadFeedback is basically a coefficient that determines of
329 // how many methods per compiler thread can be in the queue before
330 // the threshold values double.
331 class LoopPredicate : AllStatic {
332 public:
333 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
334 double threshold_scaling;
335 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
336 scale *= threshold_scaling;
337 }
338 switch(cur_level) {
339 case CompLevel_none:
340 case CompLevel_limited_profile:
341 return b >= Tier3BackEdgeThreshold * scale;
342 case CompLevel_full_profile:
343 return b >= Tier4BackEdgeThreshold * scale;
344 default:
345 return true;
346 }
347 }
348
349 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
350 double k = 1;
351 switch(cur_level) {
352 case CompLevel_none:
353 // Fall through
354 case CompLevel_limited_profile: {
355 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
356 break;
357 }
358 case CompLevel_full_profile: {
359 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
360 break;
361 }
362 default:
363 return true;
364 }
365 return apply_scaled(method, cur_level, i, b, k);
366 }
367 };
368
369 class CallPredicate : AllStatic {
370 public:
371 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
372 double threshold_scaling;
373 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
374 scale *= threshold_scaling;
375 }
376 switch(cur_level) {
377 case CompLevel_none:
378 case CompLevel_limited_profile:
379 return (i >= Tier3InvocationThreshold * scale) ||
380 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
381 case CompLevel_full_profile:
382 return (i >= Tier4InvocationThreshold * scale) ||
383 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
384 default:
385 return true;
386 }
387 }
388
389 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
390 double k = 1;
391 switch(cur_level) {
392 case CompLevel_none:
393 case CompLevel_limited_profile: {
394 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
395 break;
396 }
397 case CompLevel_full_profile: {
398 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
399 break;
400 }
401 default:
402 return true;
403 }
404 return apply_scaled(method, cur_level, i, b, k);
405 }
406 };
407
408 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
409 int comp_count = compiler_count(level);
410 if (comp_count > 0) {
411 double queue_size = CompileBroker::queue_size(level);
412 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
413
414 // Increase C1 compile threshold when the code cache is filled more
415 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
416 // The main intention is to keep enough free space for C2 compiled code
417 // to achieve peak performance if the code cache is under stress.
418 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
419 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
420 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
421 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
422 }
423 }
424 return k;
425 }
426 return 1;
427 }
428
429 void CompilationPolicy::print_counters(const char* prefix, Method* m) {
430 int invocation_count = m->invocation_count();
431 int backedge_count = m->backedge_count();
432 MethodData* mdh = m->method_data();
433 int mdo_invocations = 0, mdo_backedges = 0;
434 int mdo_invocations_start = 0, mdo_backedges_start = 0;
435 if (mdh != nullptr) {
436 mdo_invocations = mdh->invocation_count();
437 mdo_backedges = mdh->backedge_count();
438 mdo_invocations_start = mdh->invocation_count_start();
439 mdo_backedges_start = mdh->backedge_count_start();
440 }
441 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
442 invocation_count, backedge_count, prefix,
443 mdo_invocations, mdo_invocations_start,
444 mdo_backedges, mdo_backedges_start);
445 tty->print(" %smax levels=%d,%d", prefix,
446 m->highest_comp_level(), m->highest_osr_comp_level());
447 }
448
449 void CompilationPolicy::print_training_data(const char* prefix, Method* method) {
450 methodHandle m(Thread::current(), method);
451 tty->print(" %smtd: ", prefix);
452 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
453 if (mtd == nullptr) {
454 tty->print("null");
455 } else {
456 MethodData* md = mtd->final_profile();
457 tty->print("mdo=");
458 if (md == nullptr) {
459 tty->print("null");
460 } else {
461 int mdo_invocations = md->invocation_count();
462 int mdo_backedges = md->backedge_count();
463 int mdo_invocations_start = md->invocation_count_start();
464 int mdo_backedges_start = md->backedge_count_start();
465 tty->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
466 }
467 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
468 tty->print(", deps=");
469 if (ctd == nullptr) {
470 tty->print("null");
471 } else {
472 tty->print("%d", ctd->init_deps_left());
473 }
474 }
475 }
476
477 // Print an event.
478 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
479 bool inlinee_event = m != im;
480
481 ttyLocker tty_lock;
482 tty->print("%lf: [", os::elapsedTime());
483
484 switch(type) {
485 case CALL:
486 tty->print("call");
487 break;
488 case LOOP:
489 tty->print("loop");
490 break;
491 case COMPILE:
492 tty->print("compile");
493 break;
494 case FORCE_COMPILE:
495 tty->print("force-compile");
496 break;
497 case FORCE_RECOMPILE:
498 tty->print("force-recompile");
499 break;
500 case REMOVE_FROM_QUEUE:
501 tty->print("remove-from-queue");
502 break;
503 case UPDATE_IN_QUEUE:
504 tty->print("update-in-queue");
505 break;
506 case REPROFILE:
507 tty->print("reprofile");
508 break;
509 case MAKE_NOT_ENTRANT:
510 tty->print("make-not-entrant");
511 break;
512 default:
513 tty->print("unknown");
514 }
515
516 tty->print(" level=%d ", level);
517
518 ResourceMark rm;
519 char *method_name = m->name_and_sig_as_C_string();
520 tty->print("[%s", method_name);
521 if (inlinee_event) {
522 char *inlinee_name = im->name_and_sig_as_C_string();
523 tty->print(" [%s]] ", inlinee_name);
524 }
525 else tty->print("] ");
526 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
527 CompileBroker::queue_size(CompLevel_full_optimization));
528
529 tty->print(" rate=");
530 if (m->prev_time() == 0) tty->print("n/a");
531 else tty->print("%f", m->rate());
532
533 RecompilationPolicy::print_load_average();
534
535 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
536 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
537
538 if (type != COMPILE) {
539 print_counters("", m);
540 if (inlinee_event) {
541 print_counters("inlinee ", im);
542 }
543 tty->print(" compilable=");
544 bool need_comma = false;
545 if (!m->is_not_compilable(CompLevel_full_profile)) {
546 tty->print("c1");
547 need_comma = true;
548 }
549 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
550 if (need_comma) tty->print(",");
551 tty->print("c1-osr");
552 need_comma = true;
553 }
554 if (!m->is_not_compilable(CompLevel_full_optimization)) {
555 if (need_comma) tty->print(",");
556 tty->print("c2");
557 need_comma = true;
558 }
559 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
560 if (need_comma) tty->print(",");
561 tty->print("c2-osr");
562 }
563 tty->print(" status=");
564 if (m->queued_for_compilation()) {
565 tty->print("in-queue");
566 } else tty->print("idle");
567 print_training_data("", m);
568 if (inlinee_event) {
569 print_training_data("inlinee ", im);
570 }
571 }
572 tty->print_cr("]");
573 }
574
575 void CompilationPolicy::initialize() {
576 if (!CompilerConfig::is_interpreter_only()) {
577 int count = CICompilerCount;
578 bool c1_only = CompilerConfig::is_c1_only();
579 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
580
581 #ifdef _LP64
582 // Turn on ergonomic compiler count selection
583 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
584 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
585 }
586 if (CICompilerCountPerCPU) {
587 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
588 int log_cpu = log2i(os::active_processor_count());
589 int loglog_cpu = log2i(MAX2(log_cpu, 1));
590 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
591 // Make sure there is enough space in the code cache to hold all the compiler buffers
592 size_t c1_size = 0;
593 #ifdef COMPILER1
594 c1_size = Compiler::code_buffer_size();
595 #endif
596 size_t c2_size = 0;
597 #ifdef COMPILER2
598 c2_size = C2Compiler::initial_code_buffer_size();
599 #endif
600 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
601 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
602 if (count > max_count) {
603 // Lower the compiler count such that all buffers fit into the code cache
604 count = MAX2(max_count, c1_only ? 1 : 2);
605 }
606 FLAG_SET_ERGO(CICompilerCount, count);
607 }
608 #else
609 // On 32-bit systems, the number of compiler threads is limited to 3.
610 // On these systems, the virtual address space available to the JVM
611 // is usually limited to 2-4 GB (the exact value depends on the platform).
612 // As the compilers (especially C2) can consume a large amount of
613 // memory, scaling the number of compiler threads with the number of
614 // available cores can result in the exhaustion of the address space
615 /// available to the VM and thus cause the VM to crash.
616 if (FLAG_IS_DEFAULT(CICompilerCount)) {
617 count = 3;
618 FLAG_SET_ERGO(CICompilerCount, count);
619 }
620 #endif
621
622 if (c1_only) {
623 // No C2 compiler thread required
624 set_c1_count(count);
625 } else if (c2_only) {
626 set_c2_count(count);
627 } else {
628 #if INCLUDE_JVMCI
629 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
630 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
631 int c1_count = MAX2(count - libjvmci_count, 1);
632 set_c2_count(libjvmci_count);
633 set_c1_count(c1_count);
634 } else if (SCCache::is_C3_on()) {
635 set_c1_count(MAX2(count / 3, 1));
636 set_c2_count(MAX2(count - c1_count(), 1));
637 set_c3_count(1);
638 } else
639 #endif
640 {
641 set_c1_count(MAX2(count / 3, 1));
642 set_c2_count(MAX2(count - c1_count(), 1));
643 }
644 }
645 if (SCCache::is_code_load_thread_on()) {
646 set_sc_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 cached code in parallel
647 }
648 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
649 set_increase_threshold_at_ratio();
650 }
651
652 set_start_time(nanos_to_millis(os::javaTimeNanos()));
653 }
654
655
656
657
658 #ifdef ASSERT
659 bool CompilationPolicy::verify_level(CompLevel level) {
660 if (TieredCompilation && level > TieredStopAtLevel) {
661 return false;
662 }
663 // Check if there is a compiler to process the requested level
664 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
665 return false;
666 }
667 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
668 return false;
669 }
670
671 // Interpreter level is always valid.
672 if (level == CompLevel_none) {
673 return true;
674 }
675 if (CompilationModeFlag::normal()) {
676 return true;
677 } else if (CompilationModeFlag::quick_only()) {
678 return level == CompLevel_simple;
679 } else if (CompilationModeFlag::high_only()) {
680 return level == CompLevel_full_optimization;
681 } else if (CompilationModeFlag::high_only_quick_internal()) {
682 return level == CompLevel_full_optimization || level == CompLevel_simple;
683 }
684 return false;
685 }
686 #endif
687
688
689 CompLevel CompilationPolicy::highest_compile_level() {
690 CompLevel level = CompLevel_none;
691 // Setup the maximum level available for the current compiler configuration.
692 if (!CompilerConfig::is_interpreter_only()) {
693 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
694 level = CompLevel_full_optimization;
695 } else if (CompilerConfig::is_c1_enabled()) {
696 if (CompilerConfig::is_c1_simple_only()) {
697 level = CompLevel_simple;
698 } else {
699 level = CompLevel_full_profile;
700 }
701 }
702 }
703 // Clamp the maximum level with TieredStopAtLevel.
704 if (TieredCompilation) {
705 level = MIN2(level, (CompLevel) TieredStopAtLevel);
706 }
707
708 // Fix it up if after the clamping it has become invalid.
709 // Bring it monotonically down depending on the next available level for
710 // the compilation mode.
711 if (!CompilationModeFlag::normal()) {
712 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
713 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
714 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
715 if (CompilationModeFlag::quick_only()) {
716 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
717 level = CompLevel_simple;
718 }
719 } else if (CompilationModeFlag::high_only()) {
720 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
721 level = CompLevel_none;
722 }
723 } else if (CompilationModeFlag::high_only_quick_internal()) {
724 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
725 level = CompLevel_simple;
726 }
727 }
728 }
729
730 assert(verify_level(level), "Invalid highest compilation level: %d", level);
731 return level;
732 }
733
734 CompLevel CompilationPolicy::limit_level(CompLevel level) {
735 level = MIN2(level, highest_compile_level());
736 assert(verify_level(level), "Invalid compilation level: %d", level);
737 return level;
738 }
739
740 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
741 CompLevel level = CompLevel_any;
742 if (CompilationModeFlag::normal()) {
743 level = CompLevel_full_profile;
744 } else if (CompilationModeFlag::quick_only()) {
745 level = CompLevel_simple;
746 } else if (CompilationModeFlag::high_only()) {
747 level = CompLevel_full_optimization;
748 } else if (CompilationModeFlag::high_only_quick_internal()) {
749 if (force_comp_at_level_simple(method)) {
750 level = CompLevel_simple;
751 } else {
752 level = CompLevel_full_optimization;
753 }
754 }
755 assert(level != CompLevel_any, "Unhandled compilation mode");
756 return limit_level(level);
757 }
758
759 // Set carry flags on the counters if necessary
760 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
761 MethodCounters *mcs = method->method_counters();
762 if (mcs != nullptr) {
763 mcs->invocation_counter()->set_carry_on_overflow();
764 mcs->backedge_counter()->set_carry_on_overflow();
765 }
766 MethodData* mdo = method->method_data();
767 if (mdo != nullptr) {
768 mdo->invocation_counter()->set_carry_on_overflow();
769 mdo->backedge_counter()->set_carry_on_overflow();
770 }
771 }
772
773 // Called with the queue locked and with at least one element
774 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
775 CompileTask *max_blocking_task = nullptr;
776 CompileTask *max_task = nullptr;
777 Method* max_method = nullptr;
778
779 int64_t t = nanos_to_millis(os::javaTimeNanos());
780 // Iterate through the queue and find a method with a maximum rate.
781 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
782 CompileTask* next_task = task->next();
783 // If a method was unloaded or has been stale for some time, remove it from the queue.
784 // Blocking tasks and tasks submitted from whitebox API don't become stale
785 if (task->is_unloaded()) {
786 compile_queue->remove_and_mark_stale(task);
787 task = next_task;
788 continue;
789 }
790 if (task->is_scc()) {
791 // SCC tasks are on separate queue, and they should load fast. There is no need to walk
792 // the rest of the queue, just take the task and go.
793 return task;
794 }
795 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
796 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
797 // selection and/or any level adjustments. Just return them in order.
798 return task;
799 }
800 Method* method = task->method();
801 methodHandle mh(THREAD, method);
802 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
803 if (PrintTieredEvents) {
804 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
805 }
806 method->clear_queued_for_compilation();
807 method->set_pending_queue_processed(false);
808 compile_queue->remove_and_mark_stale(task);
809 task = next_task;
810 continue;
811 }
812 update_rate(t, mh);
813 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
814 // Select a method with the highest rate
815 max_task = task;
816 max_method = method;
817 }
818
819 if (task->is_blocking()) {
820 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
821 max_blocking_task = task;
822 }
823 }
824
825 task = next_task;
826 }
827
828 if (max_blocking_task != nullptr) {
829 // In blocking compilation mode, the CompileBroker will make
830 // compilations submitted by a JVMCI compiler thread non-blocking. These
831 // compilations should be scheduled after all blocking compilations
832 // to service non-compiler related compilations sooner and reduce the
833 // chance of such compilations timing out.
834 max_task = max_blocking_task;
835 max_method = max_task->method();
836 }
837
838 methodHandle max_method_h(THREAD, max_method);
839
840 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
841 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
842 max_task->set_comp_level(CompLevel_limited_profile);
843
844 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
845 false /* requires_online_compilation */,
846 CompileTask::Reason_None)) {
847 if (PrintTieredEvents) {
848 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
849 }
850 compile_queue->remove_and_mark_stale(max_task);
851 max_method->clear_queued_for_compilation();
852 return nullptr;
853 }
854
855 if (PrintTieredEvents) {
856 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
857 }
858 }
859 return max_task;
860 }
861
862 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
863 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
864 if (PrintTieredEvents) {
865 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
866 }
867 MethodData* mdo = sd->method()->method_data();
868 if (mdo != nullptr) {
869 mdo->reset_start_counters();
870 }
871 if (sd->is_top()) break;
872 }
873 }
874
875 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
876 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
877 if (PrintTieredEvents) {
878 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
879 }
880
881 #if INCLUDE_JVMCI
882 if (EnableJVMCI && UseJVMCICompiler &&
883 comp_level == CompLevel_full_optimization && !AOTLinkedClassBulkLoader::class_preloading_finished()) {
884 return nullptr;
885 }
886 #endif
887
888 if (comp_level == CompLevel_none &&
889 JvmtiExport::can_post_interpreter_events() &&
890 THREAD->is_interp_only_mode()) {
891 return nullptr;
892 }
893 if (ReplayCompiles) {
894 // Don't trigger other compiles in testing mode
895 return nullptr;
896 }
897
898 handle_counter_overflow(method);
899 if (method() != inlinee()) {
900 handle_counter_overflow(inlinee);
901 }
902
903 if (bci == InvocationEntryBci) {
904 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
905 } else {
906 // method == inlinee if the event originated in the main method
907 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
908 // Check if event led to a higher level OSR compilation
909 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
910 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
911 // It's not possible to reach the expected level so fall back to simple.
912 expected_comp_level = CompLevel_simple;
913 }
914 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
915 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
916 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
917 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
918 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
919 // Perform OSR with new nmethod
920 return osr_nm;
921 }
922 }
923 }
924 return nullptr;
925 }
926
927 // Check if the method can be compiled, change level if necessary
928 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
929 assert(verify_level(level), "Invalid compilation level requested: %d", level);
930
931 if (level == CompLevel_none) {
932 if (mh->has_compiled_code()) {
933 // Happens when we switch to interpreter to profile.
934 MutexLocker ml(Compile_lock);
935 NoSafepointVerifier nsv;
936 if (mh->has_compiled_code()) {
937 mh->code()->make_not_used();
938 }
939 // Deoptimize immediately (we don't have to wait for a compile).
940 JavaThread* jt = THREAD;
941 RegisterMap map(jt,
942 RegisterMap::UpdateMap::skip,
943 RegisterMap::ProcessFrames::include,
944 RegisterMap::WalkContinuation::skip);
945 frame fr = jt->last_frame().sender(&map);
946 Deoptimization::deoptimize_frame(jt, fr.id());
947 }
948 return;
949 }
950
951 if (!CompilationModeFlag::disable_intermediate()) {
952 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
953 // in the interpreter and then compile with C2 (the transition function will request that,
954 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
955 // pure C1.
956 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
957 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
958 compile(mh, bci, CompLevel_simple, THREAD);
959 }
960 return;
961 }
962 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
963 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
964 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
965 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
966 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
967 osr_nm->make_not_entrant();
968 }
969 compile(mh, bci, CompLevel_simple, THREAD);
970 }
971 return;
972 }
973 }
974 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
975 return;
976 }
977 if (!CompileBroker::compilation_is_in_queue(mh)) {
978 if (PrintTieredEvents) {
979 print_event(COMPILE, mh(), mh(), bci, level);
980 }
981 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
982 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
983 bool requires_online_compilation = false;
984 if (TrainingData::have_data()) {
985 MethodTrainingData* mtd = MethodTrainingData::find_fast(mh);
986 if (mtd != nullptr) {
987 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
988 if (ctd != nullptr) {
989 requires_online_compilation = (ctd->init_deps_left() > 0);
990 }
991 }
992 }
993 CompileBroker::compile_method(mh, bci, level, mh, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
994 }
995 }
996
997 // update_rate() is called from select_task() while holding a compile queue lock.
998 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
999 // Skip update if counters are absent.
1000 // Can't allocate them since we are holding compile queue lock.
1001 if (method->method_counters() == nullptr) return;
1002
1003 if (is_old(method)) {
1004 // We don't remove old methods from the queue,
1005 // so we can just zero the rate.
1006 method->set_rate(0);
1007 return;
1008 }
1009
1010 // We don't update the rate if we've just came out of a safepoint.
1011 // delta_s is the time since last safepoint in milliseconds.
1012 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1013 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1014 // How many events were there since the last time?
1015 int event_count = method->invocation_count() + method->backedge_count();
1016 int delta_e = event_count - method->prev_event_count();
1017
1018 // We should be running for at least 1ms.
1019 if (delta_s >= TieredRateUpdateMinTime) {
1020 // And we must've taken the previous point at least 1ms before.
1021 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1022 method->set_prev_time(t);
1023 method->set_prev_event_count(event_count);
1024 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1025 } else {
1026 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1027 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1028 method->set_rate(0);
1029 }
1030 }
1031 }
1032 }
1033
1034 // Check if this method has been stale for a given number of milliseconds.
1035 // See select_task().
1036 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1037 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1038 int64_t delta_t = t - method->prev_time();
1039 if (delta_t > timeout && delta_s > timeout) {
1040 int event_count = method->invocation_count() + method->backedge_count();
1041 int delta_e = event_count - method->prev_event_count();
1042 // Return true if there were no events.
1043 return delta_e == 0;
1044 }
1045 return false;
1046 }
1047
1048 // We don't remove old methods from the compile queue even if they have
1049 // very low activity. See select_task().
1050 bool CompilationPolicy::is_old(const methodHandle& method) {
1051 int i = method->invocation_count();
1052 int b = method->backedge_count();
1053 double k = TieredOldPercentage / 100.0;
1054
1055 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1056 }
1057
1058 double CompilationPolicy::weight(Method* method) {
1059 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1060 }
1061
1062 // Apply heuristics and return true if x should be compiled before y
1063 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1064 if (x->highest_comp_level() > y->highest_comp_level()) {
1065 // recompilation after deopt
1066 return true;
1067 } else
1068 if (x->highest_comp_level() == y->highest_comp_level()) {
1069 if (weight(x) > weight(y)) {
1070 return true;
1071 }
1072 }
1073 return false;
1074 }
1075
1076 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1077 assert(!x->is_scc() && !y->is_scc(), "SC tasks are not expected here");
1078 if (x->compile_reason() != y->compile_reason() && y->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1079 return true;
1080 }
1081 return false;
1082 }
1083
1084 // Is method profiled enough?
1085 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1086 MethodData* mdo = method->method_data();
1087 if (mdo != nullptr) {
1088 int i = mdo->invocation_count_delta();
1089 int b = mdo->backedge_count_delta();
1090 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1091 }
1092 return false;
1093 }
1094
1095
1096 // Determine is a method is mature.
1097 bool CompilationPolicy::is_mature(MethodData* mdo) {
1098 if (Arguments::is_compiler_only()) {
1099 // Always report profiles as immature with -Xcomp
1100 return false;
1101 }
1102 methodHandle mh(Thread::current(), mdo->method());
1103 if (mdo != nullptr) {
1104 int i = mdo->invocation_count();
1105 int b = mdo->backedge_count();
1106 double k = ProfileMaturityPercentage / 100.0;
1107 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1108 }
1109 return false;
1110 }
1111
1112 // If a method is old enough and is still in the interpreter we would want to
1113 // start profiling without waiting for the compiled method to arrive.
1114 // We also take the load on compilers into the account.
1115 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1116 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1117 return false;
1118 }
1119
1120 if (TrainingData::have_data()) {
1121 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1122 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1123 return true;
1124 }
1125 return false;
1126 }
1127
1128 if (is_old(method)) {
1129 return true;
1130 }
1131
1132 int i = method->invocation_count();
1133 int b = method->backedge_count();
1134 double k = Tier0ProfilingStartPercentage / 100.0;
1135
1136 // If the top level compiler is not keeping up, delay profiling.
1137 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1138 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1139 }
1140 return false;
1141 }
1142
1143 // Inlining control: if we're compiling a profiled method with C1 and the callee
1144 // is known to have OSRed in a C2 version, don't inline it.
1145 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1146 CompLevel comp_level = (CompLevel)env->comp_level();
1147 if (comp_level == CompLevel_full_profile ||
1148 comp_level == CompLevel_limited_profile) {
1149 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1150 }
1151 return false;
1152 }
1153
1154 // Create MDO if necessary.
1155 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1156 if (mh->is_native() ||
1157 mh->is_abstract() ||
1158 mh->is_accessor() ||
1159 mh->is_constant_getter()) {
1160 return;
1161 }
1162 if (mh->method_data() == nullptr) {
1163 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1164 }
1165 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1166 MethodData* mdo = mh->method_data();
1167 if (mdo != nullptr) {
1168 frame last_frame = THREAD->last_frame();
1169 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1170 int bci = last_frame.interpreter_frame_bci();
1171 address dp = mdo->bci_to_dp(bci);
1172 last_frame.interpreter_frame_set_mdp(dp);
1173 }
1174 }
1175 }
1176 }
1177
1178 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1179 precond(mtd != nullptr);
1180 precond(cur_level == CompLevel_none);
1181
1182 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1183 return CompLevel_none;
1184 }
1185
1186 bool training_has_profile = (mtd->final_profile() != nullptr);
1187 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1188 return CompLevel_full_profile;
1189 }
1190
1191 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1192 switch (highest_training_level) {
1193 case CompLevel_limited_profile:
1194 case CompLevel_full_profile:
1195 return CompLevel_limited_profile;
1196 case CompLevel_simple:
1197 return CompLevel_simple;
1198 case CompLevel_none:
1199 return CompLevel_none;
1200 default:
1201 break;
1202 }
1203
1204 // Now handle the case of level 4.
1205 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1206 if (!training_has_profile) {
1207 // The method was a part of a level 4 compile, but don't have a stored profile,
1208 // we need to profile it.
1209 return CompLevel_full_profile;
1210 }
1211 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1212 // If we deopted, then we reprofile
1213 if (deopt && !is_method_profiled(method)) {
1214 return CompLevel_full_profile;
1215 }
1216
1217 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1218 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1219 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1220 if (SkipTier2IfPossible && ctd->init_deps_left() == 0) {
1221 if (method->method_data() == nullptr) {
1222 create_mdo(method, THREAD);
1223 }
1224 return CompLevel_full_optimization;
1225 }
1226
1227 // Otherwise go to level 2
1228 return CompLevel_limited_profile;
1229 }
1230
1231
1232 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1233 precond(mtd != nullptr);
1234 precond(cur_level == CompLevel_limited_profile);
1235
1236 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1237
1238 // But first, check if we have a saved profile
1239 bool training_has_profile = (mtd->final_profile() != nullptr);
1240 if (!training_has_profile) {
1241 return CompLevel_full_profile;
1242 }
1243
1244
1245 assert(training_has_profile, "Have to have a profile to be here");
1246 // Check if the method is ready
1247 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1248 if (ctd != nullptr && ctd->init_deps_left() == 0) {
1249 if (method->method_data() == nullptr) {
1250 create_mdo(method, THREAD);
1251 }
1252 return CompLevel_full_optimization;
1253 }
1254
1255 // Otherwise stay at the current level
1256 return CompLevel_limited_profile;
1257 }
1258
1259
1260 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1261 precond(mtd != nullptr);
1262 precond(cur_level == CompLevel_full_profile);
1263
1264 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1265 // We have method at the full profile level and we also know that it's possibly an important method.
1266 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1267 // Check if it is adequately profiled
1268 if (is_method_profiled(method)) {
1269 return CompLevel_full_optimization;
1270 }
1271 }
1272
1273 // Otherwise stay at the current level
1274 return CompLevel_full_profile;
1275 }
1276
1277 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1278 precond(MethodTrainingData::have_data());
1279
1280 // If there is no training data recorded for this method, bail out.
1281 if (mtd == nullptr) {
1282 return cur_level;
1283 }
1284
1285 CompLevel next_level = cur_level;
1286 switch(cur_level) {
1287 default: break;
1288 case CompLevel_none:
1289 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1290 break;
1291 case CompLevel_limited_profile:
1292 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1293 break;
1294 case CompLevel_full_profile:
1295 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1296 break;
1297 }
1298
1299 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1300 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1301 return CompLevel_none;
1302 }
1303 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1304 return CompLevel_none;
1305 }
1306 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1307 }
1308
1309 /*
1310 * Method states:
1311 * 0 - interpreter (CompLevel_none)
1312 * 1 - pure C1 (CompLevel_simple)
1313 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1314 * 3 - C1 with full profiling (CompLevel_full_profile)
1315 * 4 - C2 or Graal (CompLevel_full_optimization)
1316 *
1317 * Common state transition patterns:
1318 * a. 0 -> 3 -> 4.
1319 * The most common path. But note that even in this straightforward case
1320 * profiling can start at level 0 and finish at level 3.
1321 *
1322 * b. 0 -> 2 -> 3 -> 4.
1323 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1324 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1325 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1326 *
1327 * c. 0 -> (3->2) -> 4.
1328 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1329 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1330 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1331 * without full profiling while c2 is compiling.
1332 *
1333 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1334 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1335 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1336 *
1337 * e. 0 -> 4.
1338 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1339 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1340 * the compiled version already exists).
1341 *
1342 * Note that since state 0 can be reached from any other state via deoptimization different loops
1343 * are possible.
1344 *
1345 */
1346
1347 // Common transition function. Given a predicate determines if a method should transition to another level.
1348 template<typename Predicate>
1349 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1350 CompLevel next_level = cur_level;
1351 int i = method->invocation_count();
1352 int b = method->backedge_count();
1353
1354 if (force_comp_at_level_simple(method)) {
1355 next_level = CompLevel_simple;
1356 } else {
1357 if (MethodTrainingData::have_data()) {
1358 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1359 if (mtd == nullptr) {
1360 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1361 // Feed it to the standard TF with no profiling delay.
1362 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1363 } else {
1364 next_level = trained_transition(method, cur_level, mtd, THREAD);
1365 if (cur_level == next_level) {
1366 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1367 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1368 // TF but with profiling delay.
1369 next_level = standard_transition<Predicate>(method, cur_level, true /*delay_profiling*/, disable_feedback);
1370 }
1371 }
1372 } else if (is_trivial(method) || method->is_native()) {
1373 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1374 } else {
1375 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1376 }
1377 }
1378 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1379 }
1380
1381
1382 template<typename Predicate>
1383 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1384 CompLevel next_level = cur_level;
1385 switch(cur_level) {
1386 default: break;
1387 case CompLevel_none:
1388 next_level = transition_from_none<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1389 break;
1390 case CompLevel_limited_profile:
1391 next_level = transition_from_limited_profile<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1392 break;
1393 case CompLevel_full_profile:
1394 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1395 break;
1396 }
1397 return next_level;
1398 }
1399
1400 template<typename Predicate>
1401 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1402 precond(cur_level == CompLevel_none);
1403 CompLevel next_level = cur_level;
1404 int i = method->invocation_count();
1405 int b = method->backedge_count();
1406 double scale = delay_profiling ? Tier0ProfileDelayFactor : 1.0;
1407 // If we were at full profile level, would we switch to full opt?
1408 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1409 next_level = CompLevel_full_optimization;
1410 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply_scaled(method, cur_level, i, b, scale)) {
1411 // C1-generated fully profiled code is about 30% slower than the limited profile
1412 // code that has only invocation and backedge counters. The observation is that
1413 // if C2 queue is large enough we can spend too much time in the fully profiled code
1414 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1415 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1416 // we choose to compile a limited profiled version and then recompile with full profiling
1417 // when the load on C2 goes down.
1418 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1419 next_level = CompLevel_limited_profile;
1420 } else {
1421 next_level = CompLevel_full_profile;
1422 }
1423 }
1424 return next_level;
1425 }
1426
1427 template<typename Predicate>
1428 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1429 precond(cur_level == CompLevel_full_profile);
1430 CompLevel next_level = cur_level;
1431 MethodData* mdo = method->method_data();
1432 if (mdo != nullptr) {
1433 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1434 int mdo_i = mdo->invocation_count_delta();
1435 int mdo_b = mdo->backedge_count_delta();
1436 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1437 next_level = CompLevel_full_optimization;
1438 }
1439 } else {
1440 next_level = CompLevel_full_optimization;
1441 }
1442 }
1443 return next_level;
1444 }
1445
1446 template<typename Predicate>
1447 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1448 precond(cur_level == CompLevel_limited_profile);
1449 CompLevel next_level = cur_level;
1450 int i = method->invocation_count();
1451 int b = method->backedge_count();
1452 double scale = delay_profiling ? Tier2ProfileDelayFactor : 1.0;
1453 MethodData* mdo = method->method_data();
1454 if (mdo != nullptr) {
1455 if (mdo->would_profile()) {
1456 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1457 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1458 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1459 next_level = CompLevel_full_profile;
1460 }
1461 } else {
1462 next_level = CompLevel_full_optimization;
1463 }
1464 } else {
1465 // If there is no MDO we need to profile
1466 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1467 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1468 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1469 next_level = CompLevel_full_profile;
1470 }
1471 }
1472 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1473 next_level = CompLevel_full_optimization;
1474 }
1475 return next_level;
1476 }
1477
1478
1479 // Determine if a method should be compiled with a normal entry point at a different level.
1480 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1481 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1482 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1483
1484 // If OSR method level is greater than the regular method level, the levels should be
1485 // equalized by raising the regular method level in order to avoid OSRs during each
1486 // invocation of the method.
1487 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1488 MethodData* mdo = method->method_data();
1489 guarantee(mdo != nullptr, "MDO should not be nullptr");
1490 if (mdo->invocation_count() >= 1) {
1491 next_level = CompLevel_full_optimization;
1492 }
1493 } else {
1494 next_level = MAX2(osr_level, next_level);
1495 }
1496 #if INCLUDE_JVMCI
1497 if (EnableJVMCI && UseJVMCICompiler &&
1498 next_level == CompLevel_full_optimization && !AOTLinkedClassBulkLoader::class_preloading_finished()) {
1499 next_level = cur_level;
1500 }
1501 #endif
1502 return next_level;
1503 }
1504
1505 // Determine if we should do an OSR compilation of a given method.
1506 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1507 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1508 if (cur_level == CompLevel_none) {
1509 // If there is a live OSR method that means that we deopted to the interpreter
1510 // for the transition.
1511 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1512 if (osr_level > CompLevel_none) {
1513 return osr_level;
1514 }
1515 }
1516 return next_level;
1517 }
1518
1519 // Handle the invocation event.
1520 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1521 CompLevel level, nmethod* nm, TRAPS) {
1522 if (should_create_mdo(mh, level)) {
1523 create_mdo(mh, THREAD);
1524 }
1525 CompLevel next_level = call_event(mh, level, THREAD);
1526 if (next_level != level) {
1527 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1528 compile(mh, InvocationEntryBci, next_level, THREAD);
1529 }
1530 }
1531 }
1532
1533 // Handle the back branch event. Notice that we can compile the method
1534 // with a regular entry from here.
1535 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1536 int bci, CompLevel level, nmethod* nm, TRAPS) {
1537 if (should_create_mdo(mh, level)) {
1538 create_mdo(mh, THREAD);
1539 }
1540 // Check if MDO should be created for the inlined method
1541 if (should_create_mdo(imh, level)) {
1542 create_mdo(imh, THREAD);
1543 }
1544
1545 if (is_compilation_enabled()) {
1546 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1547 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1548 // At the very least compile the OSR version
1549 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1550 compile(imh, bci, next_osr_level, CHECK);
1551 }
1552
1553 // Use loop event as an opportunity to also check if there's been
1554 // enough calls.
1555 CompLevel cur_level, next_level;
1556 if (mh() != imh()) { // If there is an enclosing method
1557 {
1558 guarantee(nm != nullptr, "Should have nmethod here");
1559 cur_level = comp_level(mh());
1560 next_level = call_event(mh, cur_level, THREAD);
1561
1562 if (max_osr_level == CompLevel_full_optimization) {
1563 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1564 bool make_not_entrant = false;
1565 if (nm->is_osr_method()) {
1566 // This is an osr method, just make it not entrant and recompile later if needed
1567 make_not_entrant = true;
1568 } else {
1569 if (next_level != CompLevel_full_optimization) {
1570 // next_level is not full opt, so we need to recompile the
1571 // enclosing method without the inlinee
1572 cur_level = CompLevel_none;
1573 make_not_entrant = true;
1574 }
1575 }
1576 if (make_not_entrant) {
1577 if (PrintTieredEvents) {
1578 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1579 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1580 }
1581 nm->make_not_entrant();
1582 }
1583 }
1584 // Fix up next_level if necessary to avoid deopts
1585 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1586 next_level = CompLevel_full_profile;
1587 }
1588 if (cur_level != next_level) {
1589 if (!CompileBroker::compilation_is_in_queue(mh)) {
1590 compile(mh, InvocationEntryBci, next_level, THREAD);
1591 }
1592 }
1593 }
1594 } else {
1595 cur_level = comp_level(mh());
1596 next_level = call_event(mh, cur_level, THREAD);
1597 if (next_level != cur_level) {
1598 if (!CompileBroker::compilation_is_in_queue(mh)) {
1599 compile(mh, InvocationEntryBci, next_level, THREAD);
1600 }
1601 }
1602 }
1603 }
1604 }
1605