1 /*
2 * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotLinkedClassBulkLoader.hpp"
26 #include "code/scopeDesc.hpp"
27 #include "compiler/compilationPolicy.hpp"
28 #include "compiler/compileBroker.hpp"
29 #include "compiler/compilerDefinitions.inline.hpp"
30 #include "compiler/compilerOracle.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/method.inline.hpp"
33 #include "oops/methodData.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/trainingData.hpp"
36 #include "prims/jvmtiExport.hpp"
37 #include "runtime/arguments.hpp"
38 #include "runtime/deoptimization.hpp"
39 #include "runtime/frame.hpp"
40 #include "runtime/frame.inline.hpp"
41 #include "runtime/globals_extension.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/safepoint.hpp"
44 #include "runtime/safepointVerifiers.hpp"
45 #ifdef COMPILER1
46 #include "c1/c1_Compiler.hpp"
47 #endif
48 #ifdef COMPILER2
49 #include "opto/c2compiler.hpp"
50 #endif
51 #if INCLUDE_JVMCI
52 #include "jvmci/jvmci.hpp"
53 #endif
54
55 int64_t CompilationPolicy::_start_time = 0;
56 int CompilationPolicy::_c1_count = 0;
57 int CompilationPolicy::_c2_count = 0;
58 double CompilationPolicy::_increase_threshold_at_ratio = 0;
59
60 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
61
62 void compilationPolicy_init() {
63 CompilationPolicy::initialize();
64 }
65
66 int CompilationPolicy::compiler_count(CompLevel comp_level) {
67 if (is_c1_compile(comp_level)) {
68 return c1_count();
69 } else if (is_c2_compile(comp_level)) {
70 return c2_count();
71 }
72 return 0;
73 }
74
75 // Returns true if m must be compiled before executing it
76 // This is intended to force compiles for methods (usually for
77 // debugging) that would otherwise be interpreted for some reason.
78 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
79 // Don't allow Xcomp to cause compiles in replay mode
80 if (ReplayCompiles) return false;
81
82 if (m->has_compiled_code()) return false; // already compiled
83 if (!can_be_compiled(m, comp_level)) return false;
84
85 return !UseInterpreter || // must compile all methods
86 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
87 }
88
89 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
90 if (m->method_holder()->is_not_initialized()) {
91 // 'is_not_initialized' means not only '!is_initialized', but also that
92 // initialization has not been started yet ('!being_initialized')
93 // Do not force compilation of methods in uninitialized classes.
94 return;
95 }
96 if (!m->is_native() && MethodTrainingData::have_data()) {
97 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
98 if (mtd == nullptr) {
99 return; // there is no training data recorded for m
100 }
101 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
102 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
103 if (next_level != cur_level && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
104 if (PrintTieredEvents) {
105 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
106 }
107 CompileBroker::compile_method(m, InvocationEntryBci, next_level, 0, CompileTask::Reason_MustBeCompiled, THREAD);
108 if (HAS_PENDING_EXCEPTION) {
109 CLEAR_PENDING_EXCEPTION;
110 }
111 }
112 }
113 }
114
115 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
116 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
117 // don't force compilation, resolve was on behalf of compiler
118 return;
119 }
120 if (m->method_holder()->is_not_initialized()) {
121 // 'is_not_initialized' means not only '!is_initialized', but also that
122 // initialization has not been started yet ('!being_initialized')
123 // Do not force compilation of methods in uninitialized classes.
124 // Note that doing this would throw an assert later,
125 // in CompileBroker::compile_method.
126 // We sometimes use the link resolver to do reflective lookups
127 // even before classes are initialized.
128 return;
129 }
130
131 if (must_be_compiled(m)) {
132 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
133 CompLevel level = initial_compile_level(m);
134 if (PrintTieredEvents) {
135 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
136 }
137 CompileBroker::compile_method(m, InvocationEntryBci, level, 0, CompileTask::Reason_MustBeCompiled, THREAD);
138 }
139 }
140
141 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, TRAPS) {
142 if (!klass->has_init_deps_processed()) {
143 ResourceMark rm;
144 log_debug(training)("Replay training: %s", klass->external_name());
145
146 KlassTrainingData* ktd = KlassTrainingData::find(klass);
147 if (ktd != nullptr) {
148 guarantee(ktd->has_holder(), "");
149 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
150 assert(klass->has_init_deps_processed(), "");
151 if (AOTCompileEagerly) {
152 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
153 if (ctd->init_deps_left() == 0) {
154 MethodTrainingData* mtd = ctd->method();
155 if (mtd->has_holder()) {
156 const methodHandle mh(THREAD, const_cast<Method*>(mtd->holder()));
157 CompilationPolicy::maybe_compile_early(mh, THREAD);
158 }
159 }
160 });
161 }
162 }
163 }
164 }
165
166 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, TRAPS) {
167 assert(klass->is_initialized(), "");
168 if (TrainingData::have_data() && klass->is_shared()) {
169 _training_replay_queue.push(klass, TrainingReplayQueue_lock, THREAD);
170 }
171 }
172
173 // For TrainingReplayQueue
174 template<>
175 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
176 int pos = 0;
177 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
178 ResourceMark rm;
179 InstanceKlass* ik = cur->value();
180 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
181 }
182 }
183
184 void CompilationPolicy::replay_training_at_init_loop(TRAPS) {
185 while (!CompileBroker::is_compilation_disabled_forever()) {
186 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, THREAD);
187 if (ik != nullptr) {
188 replay_training_at_init_impl(ik, THREAD);
189 }
190 }
191 }
192
193 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
194 if (comp_level == CompLevel_any) {
195 if (CompilerConfig::is_c1_only()) {
196 comp_level = CompLevel_simple;
197 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
198 comp_level = CompLevel_full_optimization;
199 }
200 }
201 return comp_level;
202 }
203
204 // Returns true if m is allowed to be compiled
205 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
206 // allow any levels for WhiteBox
207 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
208
209 if (m->is_abstract()) return false;
210 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
211
212 // Math intrinsics should never be compiled as this can lead to
213 // monotonicity problems because the interpreter will prefer the
214 // compiled code to the intrinsic version. This can't happen in
215 // production because the invocation counter can't be incremented
216 // but we shouldn't expose the system to this problem in testing
217 // modes.
218 if (!AbstractInterpreter::can_be_compiled(m)) {
219 return false;
220 }
221 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
222 if (comp_level == CompLevel_any || is_compile(comp_level)) {
223 return !m->is_not_compilable(comp_level);
224 }
225 return false;
226 }
227
228 // Returns true if m is allowed to be osr compiled
229 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
230 bool result = false;
231 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
232 if (comp_level == CompLevel_any || is_compile(comp_level)) {
233 result = !m->is_not_osr_compilable(comp_level);
234 }
235 return (result && can_be_compiled(m, comp_level));
236 }
237
238 bool CompilationPolicy::is_compilation_enabled() {
239 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
240 return CompileBroker::should_compile_new_jobs();
241 }
242
243 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
244 // Remove unloaded methods from the queue
245 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
246 CompileTask* next = task->next();
247 if (task->is_unloaded()) {
248 compile_queue->remove_and_mark_stale(task);
249 }
250 task = next;
251 }
252 #if INCLUDE_JVMCI
253 if (UseJVMCICompiler && !BackgroundCompilation) {
254 /*
255 * In blocking compilation mode, the CompileBroker will make
256 * compilations submitted by a JVMCI compiler thread non-blocking. These
257 * compilations should be scheduled after all blocking compilations
258 * to service non-compiler related compilations sooner and reduce the
259 * chance of such compilations timing out.
260 */
261 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
262 if (task->is_blocking()) {
263 return task;
264 }
265 }
266 }
267 #endif
268 return compile_queue->first();
269 }
270
271 // Simple methods are as good being compiled with C1 as C2.
272 // Determine if a given method is such a case.
273 bool CompilationPolicy::is_trivial(const methodHandle& method) {
274 if (method->is_accessor() ||
275 method->is_constant_getter()) {
276 return true;
277 }
278 return false;
279 }
280
281 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
282 if (CompilationModeFlag::quick_internal()) {
283 #if INCLUDE_JVMCI
284 if (UseJVMCICompiler) {
285 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
286 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
287 return true;
288 }
289 }
290 #endif
291 }
292 return false;
293 }
294
295 CompLevel CompilationPolicy::comp_level(Method* method) {
296 nmethod *nm = method->code();
297 if (nm != nullptr && nm->is_in_use()) {
298 return (CompLevel)nm->comp_level();
299 }
300 return CompLevel_none;
301 }
302
303 // Call and loop predicates determine whether a transition to a higher
304 // compilation level should be performed (pointers to predicate functions
305 // are passed to common()).
306 // Tier?LoadFeedback is basically a coefficient that determines of
307 // how many methods per compiler thread can be in the queue before
308 // the threshold values double.
309 class LoopPredicate : AllStatic {
310 public:
311 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
312 double threshold_scaling;
313 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
314 scale *= threshold_scaling;
315 }
316 switch(cur_level) {
317 case CompLevel_none:
318 case CompLevel_limited_profile:
319 return b >= Tier3BackEdgeThreshold * scale;
320 case CompLevel_full_profile:
321 return b >= Tier4BackEdgeThreshold * scale;
322 default:
323 return true;
324 }
325 }
326
327 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
328 double k = 1;
329 switch(cur_level) {
330 case CompLevel_none:
331 // Fall through
332 case CompLevel_limited_profile: {
333 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
334 break;
335 }
336 case CompLevel_full_profile: {
337 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
338 break;
339 }
340 default:
341 return true;
342 }
343 return apply_scaled(method, cur_level, i, b, k);
344 }
345 };
346
347 class CallPredicate : AllStatic {
348 public:
349 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
350 double threshold_scaling;
351 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
352 scale *= threshold_scaling;
353 }
354 switch(cur_level) {
355 case CompLevel_none:
356 case CompLevel_limited_profile:
357 return (i >= Tier3InvocationThreshold * scale) ||
358 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
359 case CompLevel_full_profile:
360 return (i >= Tier4InvocationThreshold * scale) ||
361 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
362 default:
363 return true;
364 }
365 }
366
367 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
368 double k = 1;
369 switch(cur_level) {
370 case CompLevel_none:
371 case CompLevel_limited_profile: {
372 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
373 break;
374 }
375 case CompLevel_full_profile: {
376 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
377 break;
378 }
379 default:
380 return true;
381 }
382 return apply_scaled(method, cur_level, i, b, k);
383 }
384 };
385
386 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
387 int comp_count = compiler_count(level);
388 if (comp_count > 0) {
389 double queue_size = CompileBroker::queue_size(level);
390 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
391
392 // Increase C1 compile threshold when the code cache is filled more
393 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
394 // The main intention is to keep enough free space for C2 compiled code
395 // to achieve peak performance if the code cache is under stress.
396 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
397 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
398 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
399 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
400 }
401 }
402 return k;
403 }
404 return 1;
405 }
406
407 void CompilationPolicy::print_counters(const char* prefix, Method* m) {
408 int invocation_count = m->invocation_count();
409 int backedge_count = m->backedge_count();
410 MethodData* mdh = m->method_data();
411 int mdo_invocations = 0, mdo_backedges = 0;
412 int mdo_invocations_start = 0, mdo_backedges_start = 0;
413 if (mdh != nullptr) {
414 mdo_invocations = mdh->invocation_count();
415 mdo_backedges = mdh->backedge_count();
416 mdo_invocations_start = mdh->invocation_count_start();
417 mdo_backedges_start = mdh->backedge_count_start();
418 }
419 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
420 invocation_count, backedge_count, prefix,
421 mdo_invocations, mdo_invocations_start,
422 mdo_backedges, mdo_backedges_start);
423 tty->print(" %smax levels=%d,%d", prefix,
424 m->highest_comp_level(), m->highest_osr_comp_level());
425 }
426
427 void CompilationPolicy::print_training_data(const char* prefix, Method* method) {
428 methodHandle m(Thread::current(), method);
429 tty->print(" %smtd: ", prefix);
430 MethodTrainingData* mtd = MethodTrainingData::find(m);
431 if (mtd == nullptr) {
432 tty->print("null");
433 } else {
434 MethodData* md = mtd->final_profile();
435 tty->print("mdo=");
436 if (md == nullptr) {
437 tty->print("null");
438 } else {
439 int mdo_invocations = md->invocation_count();
440 int mdo_backedges = md->backedge_count();
441 int mdo_invocations_start = md->invocation_count_start();
442 int mdo_backedges_start = md->backedge_count_start();
443 tty->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
444 }
445 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
446 tty->print(", deps=");
447 if (ctd == nullptr) {
448 tty->print("null");
449 } else {
450 tty->print("%d", ctd->init_deps_left());
451 }
452 }
453 }
454
455 // Print an event.
456 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
457 bool inlinee_event = m != im;
458
459 ttyLocker tty_lock;
460 tty->print("%lf: [", os::elapsedTime());
461
462 switch(type) {
463 case CALL:
464 tty->print("call");
465 break;
466 case LOOP:
467 tty->print("loop");
468 break;
469 case COMPILE:
470 tty->print("compile");
471 break;
472 case FORCE_COMPILE:
473 tty->print("force-compile");
474 break;
475 case REMOVE_FROM_QUEUE:
476 tty->print("remove-from-queue");
477 break;
478 case UPDATE_IN_QUEUE:
479 tty->print("update-in-queue");
480 break;
481 case REPROFILE:
482 tty->print("reprofile");
483 break;
484 case MAKE_NOT_ENTRANT:
485 tty->print("make-not-entrant");
486 break;
487 default:
488 tty->print("unknown");
489 }
490
491 tty->print(" level=%d ", level);
492
493 ResourceMark rm;
494 char *method_name = m->name_and_sig_as_C_string();
495 tty->print("[%s", method_name);
496 if (inlinee_event) {
497 char *inlinee_name = im->name_and_sig_as_C_string();
498 tty->print(" [%s]] ", inlinee_name);
499 }
500 else tty->print("] ");
501 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
502 CompileBroker::queue_size(CompLevel_full_optimization));
503
504 tty->print(" rate=");
505 if (m->prev_time() == 0) tty->print("n/a");
506 else tty->print("%f", m->rate());
507
508 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
509 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
510
511 if (type != COMPILE) {
512 print_counters("", m);
513 if (inlinee_event) {
514 print_counters("inlinee ", im);
515 }
516 tty->print(" compilable=");
517 bool need_comma = false;
518 if (!m->is_not_compilable(CompLevel_full_profile)) {
519 tty->print("c1");
520 need_comma = true;
521 }
522 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
523 if (need_comma) tty->print(",");
524 tty->print("c1-osr");
525 need_comma = true;
526 }
527 if (!m->is_not_compilable(CompLevel_full_optimization)) {
528 if (need_comma) tty->print(",");
529 tty->print("c2");
530 need_comma = true;
531 }
532 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
533 if (need_comma) tty->print(",");
534 tty->print("c2-osr");
535 }
536 tty->print(" status=");
537 if (m->queued_for_compilation()) {
538 tty->print("in-queue");
539 } else tty->print("idle");
540 print_training_data("", m);
541 if (inlinee_event) {
542 print_training_data("inlinee ", im);
543 }
544 }
545 tty->print_cr("]");
546 }
547
548 void CompilationPolicy::initialize() {
549 if (!CompilerConfig::is_interpreter_only()) {
550 int count = CICompilerCount;
551 bool c1_only = CompilerConfig::is_c1_only();
552 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
553
554 #ifdef _LP64
555 // Turn on ergonomic compiler count selection
556 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
557 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
558 }
559 if (CICompilerCountPerCPU) {
560 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
561 int log_cpu = log2i(os::active_processor_count());
562 int loglog_cpu = log2i(MAX2(log_cpu, 1));
563 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
564 // Make sure there is enough space in the code cache to hold all the compiler buffers
565 size_t c1_size = 0;
566 #ifdef COMPILER1
567 c1_size = Compiler::code_buffer_size();
568 #endif
569 size_t c2_size = 0;
570 #ifdef COMPILER2
571 c2_size = C2Compiler::initial_code_buffer_size();
572 #endif
573 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
574 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
575 if (count > max_count) {
576 // Lower the compiler count such that all buffers fit into the code cache
577 count = MAX2(max_count, c1_only ? 1 : 2);
578 }
579 FLAG_SET_ERGO(CICompilerCount, count);
580 }
581 #else
582 // On 32-bit systems, the number of compiler threads is limited to 3.
583 // On these systems, the virtual address space available to the JVM
584 // is usually limited to 2-4 GB (the exact value depends on the platform).
585 // As the compilers (especially C2) can consume a large amount of
586 // memory, scaling the number of compiler threads with the number of
587 // available cores can result in the exhaustion of the address space
588 /// available to the VM and thus cause the VM to crash.
589 if (FLAG_IS_DEFAULT(CICompilerCount)) {
590 count = 3;
591 FLAG_SET_ERGO(CICompilerCount, count);
592 }
593 #endif
594
595 if (c1_only) {
596 // No C2 compiler thread required
597 set_c1_count(count);
598 } else if (c2_only) {
599 set_c2_count(count);
600 } else {
601 #if INCLUDE_JVMCI
602 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
603 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
604 int c1_count = MAX2(count - libjvmci_count, 1);
605 set_c2_count(libjvmci_count);
606 set_c1_count(c1_count);
607 } else
608 #endif
609 {
610 set_c1_count(MAX2(count / 3, 1));
611 set_c2_count(MAX2(count - c1_count(), 1));
612 }
613 }
614 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
615 set_increase_threshold_at_ratio();
616 }
617 set_start_time(nanos_to_millis(os::javaTimeNanos()));
618 }
619
620
621 #ifdef ASSERT
622 bool CompilationPolicy::verify_level(CompLevel level) {
623 if (TieredCompilation && level > TieredStopAtLevel) {
624 return false;
625 }
626 // Check if there is a compiler to process the requested level
627 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
628 return false;
629 }
630 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
631 return false;
632 }
633
634 // Interpreter level is always valid.
635 if (level == CompLevel_none) {
636 return true;
637 }
638 if (CompilationModeFlag::normal()) {
639 return true;
640 } else if (CompilationModeFlag::quick_only()) {
641 return level == CompLevel_simple;
642 } else if (CompilationModeFlag::high_only()) {
643 return level == CompLevel_full_optimization;
644 } else if (CompilationModeFlag::high_only_quick_internal()) {
645 return level == CompLevel_full_optimization || level == CompLevel_simple;
646 }
647 return false;
648 }
649 #endif
650
651
652 CompLevel CompilationPolicy::highest_compile_level() {
653 CompLevel level = CompLevel_none;
654 // Setup the maximum level available for the current compiler configuration.
655 if (!CompilerConfig::is_interpreter_only()) {
656 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
657 level = CompLevel_full_optimization;
658 } else if (CompilerConfig::is_c1_enabled()) {
659 if (CompilerConfig::is_c1_simple_only()) {
660 level = CompLevel_simple;
661 } else {
662 level = CompLevel_full_profile;
663 }
664 }
665 }
666 // Clamp the maximum level with TieredStopAtLevel.
667 if (TieredCompilation) {
668 level = MIN2(level, (CompLevel) TieredStopAtLevel);
669 }
670
671 // Fix it up if after the clamping it has become invalid.
672 // Bring it monotonically down depending on the next available level for
673 // the compilation mode.
674 if (!CompilationModeFlag::normal()) {
675 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
676 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
677 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
678 if (CompilationModeFlag::quick_only()) {
679 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
680 level = CompLevel_simple;
681 }
682 } else if (CompilationModeFlag::high_only()) {
683 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
684 level = CompLevel_none;
685 }
686 } else if (CompilationModeFlag::high_only_quick_internal()) {
687 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
688 level = CompLevel_simple;
689 }
690 }
691 }
692
693 assert(verify_level(level), "Invalid highest compilation level: %d", level);
694 return level;
695 }
696
697 CompLevel CompilationPolicy::limit_level(CompLevel level) {
698 level = MIN2(level, highest_compile_level());
699 assert(verify_level(level), "Invalid compilation level: %d", level);
700 return level;
701 }
702
703 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
704 CompLevel level = CompLevel_any;
705 if (CompilationModeFlag::normal()) {
706 level = CompLevel_full_profile;
707 } else if (CompilationModeFlag::quick_only()) {
708 level = CompLevel_simple;
709 } else if (CompilationModeFlag::high_only()) {
710 level = CompLevel_full_optimization;
711 } else if (CompilationModeFlag::high_only_quick_internal()) {
712 if (force_comp_at_level_simple(method)) {
713 level = CompLevel_simple;
714 } else {
715 level = CompLevel_full_optimization;
716 }
717 }
718 assert(level != CompLevel_any, "Unhandled compilation mode");
719 return limit_level(level);
720 }
721
722 // Set carry flags on the counters if necessary
723 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
724 MethodCounters *mcs = method->method_counters();
725 if (mcs != nullptr) {
726 mcs->invocation_counter()->set_carry_on_overflow();
727 mcs->backedge_counter()->set_carry_on_overflow();
728 }
729 MethodData* mdo = method->method_data();
730 if (mdo != nullptr) {
731 mdo->invocation_counter()->set_carry_on_overflow();
732 mdo->backedge_counter()->set_carry_on_overflow();
733 }
734 }
735
736 // Called with the queue locked and with at least one element
737 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
738 CompileTask *max_blocking_task = nullptr;
739 CompileTask *max_task = nullptr;
740 Method* max_method = nullptr;
741
742 int64_t t = nanos_to_millis(os::javaTimeNanos());
743 // Iterate through the queue and find a method with a maximum rate.
744 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
745 CompileTask* next_task = task->next();
746 // If a method was unloaded or has been stale for some time, remove it from the queue.
747 // Blocking tasks and tasks submitted from whitebox API don't become stale
748 if (task->is_unloaded()) {
749 compile_queue->remove_and_mark_stale(task);
750 task = next_task;
751 continue;
752 }
753 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
754 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
755 // selection and/or any level adjustments. Just return them in order.
756 return task;
757 }
758 Method* method = task->method();
759 methodHandle mh(THREAD, method);
760 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
761 if (PrintTieredEvents) {
762 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
763 }
764 method->clear_queued_for_compilation();
765 compile_queue->remove_and_mark_stale(task);
766 task = next_task;
767 continue;
768 }
769 update_rate(t, mh);
770 if (max_task == nullptr || compare_methods(method, max_method)) {
771 // Select a method with the highest rate
772 max_task = task;
773 max_method = method;
774 }
775
776 if (task->is_blocking()) {
777 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
778 max_blocking_task = task;
779 }
780 }
781
782 task = next_task;
783 }
784
785 if (max_blocking_task != nullptr) {
786 // In blocking compilation mode, the CompileBroker will make
787 // compilations submitted by a JVMCI compiler thread non-blocking. These
788 // compilations should be scheduled after all blocking compilations
789 // to service non-compiler related compilations sooner and reduce the
790 // chance of such compilations timing out.
791 max_task = max_blocking_task;
792 max_method = max_task->method();
793 }
794
795 methodHandle max_method_h(THREAD, max_method);
796
797 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
798 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
799 max_task->set_comp_level(CompLevel_limited_profile);
800
801 if (CompileBroker::compilation_is_complete(max_method_h, max_task->osr_bci(), CompLevel_limited_profile)) {
802 if (PrintTieredEvents) {
803 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
804 }
805 compile_queue->remove_and_mark_stale(max_task);
806 max_method->clear_queued_for_compilation();
807 return nullptr;
808 }
809
810 if (PrintTieredEvents) {
811 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
812 }
813 }
814 return max_task;
815 }
816
817 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
818 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
819 if (PrintTieredEvents) {
820 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
821 }
822 MethodData* mdo = sd->method()->method_data();
823 if (mdo != nullptr) {
824 mdo->reset_start_counters();
825 }
826 if (sd->is_top()) break;
827 }
828 }
829
830 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
831 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
832 if (PrintTieredEvents) {
833 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
834 }
835
836 #if INCLUDE_JVMCI
837 if (EnableJVMCI && UseJVMCICompiler &&
838 comp_level == CompLevel_full_optimization CDS_ONLY(&& !AOTLinkedClassBulkLoader::class_preloading_finished())) {
839 return nullptr;
840 }
841 #endif
842
843 if (comp_level == CompLevel_none &&
844 JvmtiExport::can_post_interpreter_events() &&
845 THREAD->is_interp_only_mode()) {
846 return nullptr;
847 }
848 if (ReplayCompiles) {
849 // Don't trigger other compiles in testing mode
850 return nullptr;
851 }
852
853 handle_counter_overflow(method);
854 if (method() != inlinee()) {
855 handle_counter_overflow(inlinee);
856 }
857
858 if (bci == InvocationEntryBci) {
859 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
860 } else {
861 // method == inlinee if the event originated in the main method
862 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
863 // Check if event led to a higher level OSR compilation
864 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
865 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
866 // It's not possible to reach the expected level so fall back to simple.
867 expected_comp_level = CompLevel_simple;
868 }
869 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
870 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
871 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
872 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
873 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
874 // Perform OSR with new nmethod
875 return osr_nm;
876 }
877 }
878 }
879 return nullptr;
880 }
881
882 // Check if the method can be compiled, change level if necessary
883 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
884 assert(verify_level(level), "Invalid compilation level requested: %d", level);
885
886 if (level == CompLevel_none) {
887 if (mh->has_compiled_code()) {
888 // Happens when we switch to interpreter to profile.
889 MutexLocker ml(Compile_lock);
890 NoSafepointVerifier nsv;
891 if (mh->has_compiled_code()) {
892 mh->code()->make_not_used();
893 }
894 // Deoptimize immediately (we don't have to wait for a compile).
895 JavaThread* jt = THREAD;
896 RegisterMap map(jt,
897 RegisterMap::UpdateMap::skip,
898 RegisterMap::ProcessFrames::include,
899 RegisterMap::WalkContinuation::skip);
900 frame fr = jt->last_frame().sender(&map);
901 Deoptimization::deoptimize_frame(jt, fr.id());
902 }
903 return;
904 }
905
906 if (!CompilationModeFlag::disable_intermediate()) {
907 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
908 // in the interpreter and then compile with C2 (the transition function will request that,
909 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
910 // pure C1.
911 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
912 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
913 compile(mh, bci, CompLevel_simple, THREAD);
914 }
915 return;
916 }
917 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
918 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
919 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
920 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
921 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
922 osr_nm->make_not_entrant("OSR invalidation for compiling with C1");
923 }
924 compile(mh, bci, CompLevel_simple, THREAD);
925 }
926 return;
927 }
928 }
929 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
930 return;
931 }
932 if (!CompileBroker::compilation_is_in_queue(mh)) {
933 if (PrintTieredEvents) {
934 print_event(COMPILE, mh(), mh(), bci, level);
935 }
936 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
937 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
938 CompileBroker::compile_method(mh, bci, level, hot_count, CompileTask::Reason_Tiered, THREAD);
939 }
940 }
941
942 // update_rate() is called from select_task() while holding a compile queue lock.
943 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
944 // Skip update if counters are absent.
945 // Can't allocate them since we are holding compile queue lock.
946 if (method->method_counters() == nullptr) return;
947
948 if (is_old(method)) {
949 // We don't remove old methods from the queue,
950 // so we can just zero the rate.
951 method->set_rate(0);
952 return;
953 }
954
955 // We don't update the rate if we've just came out of a safepoint.
956 // delta_s is the time since last safepoint in milliseconds.
957 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
958 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
959 // How many events were there since the last time?
960 int event_count = method->invocation_count() + method->backedge_count();
961 int delta_e = event_count - method->prev_event_count();
962
963 // We should be running for at least 1ms.
964 if (delta_s >= TieredRateUpdateMinTime) {
965 // And we must've taken the previous point at least 1ms before.
966 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
967 method->set_prev_time(t);
968 method->set_prev_event_count(event_count);
969 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
970 } else {
971 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
972 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
973 method->set_rate(0);
974 }
975 }
976 }
977 }
978
979 // Check if this method has been stale for a given number of milliseconds.
980 // See select_task().
981 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
982 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
983 int64_t delta_t = t - method->prev_time();
984 if (delta_t > timeout && delta_s > timeout) {
985 int event_count = method->invocation_count() + method->backedge_count();
986 int delta_e = event_count - method->prev_event_count();
987 // Return true if there were no events.
988 return delta_e == 0;
989 }
990 return false;
991 }
992
993 // We don't remove old methods from the compile queue even if they have
994 // very low activity. See select_task().
995 bool CompilationPolicy::is_old(const methodHandle& method) {
996 int i = method->invocation_count();
997 int b = method->backedge_count();
998 double k = TieredOldPercentage / 100.0;
999
1000 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1001 }
1002
1003 double CompilationPolicy::weight(Method* method) {
1004 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1005 }
1006
1007 // Apply heuristics and return true if x should be compiled before y
1008 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1009 if (x->highest_comp_level() > y->highest_comp_level()) {
1010 // recompilation after deopt
1011 return true;
1012 } else
1013 if (x->highest_comp_level() == y->highest_comp_level()) {
1014 if (weight(x) > weight(y)) {
1015 return true;
1016 }
1017 }
1018 return false;
1019 }
1020
1021 // Is method profiled enough?
1022 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1023 MethodData* mdo = method->method_data();
1024 if (mdo != nullptr) {
1025 int i = mdo->invocation_count_delta();
1026 int b = mdo->backedge_count_delta();
1027 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1028 }
1029 return false;
1030 }
1031
1032
1033 // Determine is a method is mature.
1034 bool CompilationPolicy::is_mature(MethodData* mdo) {
1035 if (Arguments::is_compiler_only()) {
1036 // Always report profiles as immature with -Xcomp
1037 return false;
1038 }
1039 methodHandle mh(Thread::current(), mdo->method());
1040 if (mdo != nullptr) {
1041 int i = mdo->invocation_count();
1042 int b = mdo->backedge_count();
1043 double k = ProfileMaturityPercentage / 100.0;
1044 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1045 }
1046 return false;
1047 }
1048
1049 // If a method is old enough and is still in the interpreter we would want to
1050 // start profiling without waiting for the compiled method to arrive.
1051 // We also take the load on compilers into the account.
1052 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1053 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1054 return false;
1055 }
1056
1057 if (TrainingData::have_data()) {
1058 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1059 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1060 return true;
1061 }
1062 }
1063
1064 if (is_old(method)) {
1065 return true;
1066 }
1067
1068 int i = method->invocation_count();
1069 int b = method->backedge_count();
1070 double k = Tier0ProfilingStartPercentage / 100.0;
1071
1072 // If the top level compiler is not keeping up, delay profiling.
1073 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1074 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1075 }
1076 return false;
1077 }
1078
1079 // Inlining control: if we're compiling a profiled method with C1 and the callee
1080 // is known to have OSRed in a C2 version, don't inline it.
1081 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1082 CompLevel comp_level = (CompLevel)env->comp_level();
1083 if (comp_level == CompLevel_full_profile ||
1084 comp_level == CompLevel_limited_profile) {
1085 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1086 }
1087 return false;
1088 }
1089
1090 // Create MDO if necessary.
1091 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1092 if (mh->is_native() ||
1093 mh->is_abstract() ||
1094 mh->is_accessor() ||
1095 mh->is_constant_getter()) {
1096 return;
1097 }
1098 if (mh->method_data() == nullptr) {
1099 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1100 }
1101 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1102 MethodData* mdo = mh->method_data();
1103 if (mdo != nullptr) {
1104 frame last_frame = THREAD->last_frame();
1105 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1106 int bci = last_frame.interpreter_frame_bci();
1107 address dp = mdo->bci_to_dp(bci);
1108 last_frame.interpreter_frame_set_mdp(dp);
1109 }
1110 }
1111 }
1112 }
1113
1114 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1115 precond(mtd != nullptr);
1116 precond(cur_level == CompLevel_none);
1117
1118 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1119 return CompLevel_none;
1120 }
1121
1122 bool training_has_profile = (mtd->final_profile() != nullptr);
1123 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1124 return CompLevel_full_profile;
1125 }
1126
1127 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1128 switch (highest_training_level) {
1129 case CompLevel_limited_profile:
1130 case CompLevel_full_profile:
1131 return CompLevel_limited_profile;
1132 case CompLevel_simple:
1133 return CompLevel_simple;
1134 case CompLevel_none:
1135 return CompLevel_none;
1136 default:
1137 break;
1138 }
1139
1140 // Now handle the case of level 4.
1141 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1142 if (!training_has_profile) {
1143 // The method was a part of a level 4 compile, but don't have a stored profile,
1144 // we need to profile it.
1145 return CompLevel_full_profile;
1146 }
1147 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1148 // If we deopted, then we reprofile
1149 if (deopt && !is_method_profiled(method)) {
1150 return CompLevel_full_profile;
1151 }
1152
1153 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1154 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1155 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1156 if (SkipTier2IfPossible && ctd->init_deps_left() == 0) {
1157 if (method->method_data() == nullptr) {
1158 create_mdo(method, THREAD);
1159 }
1160 return CompLevel_full_optimization;
1161 }
1162
1163 // Otherwise go to level 2
1164 return CompLevel_limited_profile;
1165 }
1166
1167
1168 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1169 precond(mtd != nullptr);
1170 precond(cur_level == CompLevel_limited_profile);
1171
1172 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1173
1174 // But first, check if we have a saved profile
1175 bool training_has_profile = (mtd->final_profile() != nullptr);
1176 if (!training_has_profile) {
1177 return CompLevel_full_profile;
1178 }
1179
1180
1181 assert(training_has_profile, "Have to have a profile to be here");
1182 // Check if the method is ready
1183 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1184 if (ctd != nullptr && ctd->init_deps_left() == 0) {
1185 if (method->method_data() == nullptr) {
1186 create_mdo(method, THREAD);
1187 }
1188 return CompLevel_full_optimization;
1189 }
1190
1191 // Otherwise stay at the current level
1192 return CompLevel_limited_profile;
1193 }
1194
1195
1196 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1197 precond(mtd != nullptr);
1198 precond(cur_level == CompLevel_full_profile);
1199
1200 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1201 // We have method at the full profile level and we also know that it's possibly an important method.
1202 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1203 // Check if it is adequately profiled
1204 if (is_method_profiled(method)) {
1205 return CompLevel_full_optimization;
1206 }
1207 }
1208
1209 // Otherwise stay at the current level
1210 return CompLevel_full_profile;
1211 }
1212
1213 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1214 precond(MethodTrainingData::have_data());
1215
1216 // If there is no training data recorded for this method, bail out.
1217 if (mtd == nullptr) {
1218 return cur_level;
1219 }
1220
1221 CompLevel next_level = cur_level;
1222 switch(cur_level) {
1223 default: break;
1224 case CompLevel_none:
1225 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1226 break;
1227 case CompLevel_limited_profile:
1228 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1229 break;
1230 case CompLevel_full_profile:
1231 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1232 break;
1233 }
1234
1235 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1236 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1237 return CompLevel_none;
1238 }
1239 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1240 return CompLevel_none;
1241 }
1242 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1243 }
1244
1245 /*
1246 * Method states:
1247 * 0 - interpreter (CompLevel_none)
1248 * 1 - pure C1 (CompLevel_simple)
1249 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1250 * 3 - C1 with full profiling (CompLevel_full_profile)
1251 * 4 - C2 or Graal (CompLevel_full_optimization)
1252 *
1253 * Common state transition patterns:
1254 * a. 0 -> 3 -> 4.
1255 * The most common path. But note that even in this straightforward case
1256 * profiling can start at level 0 and finish at level 3.
1257 *
1258 * b. 0 -> 2 -> 3 -> 4.
1259 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1260 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1261 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1262 *
1263 * c. 0 -> (3->2) -> 4.
1264 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1265 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1266 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1267 * without full profiling while c2 is compiling.
1268 *
1269 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1270 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1271 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1272 *
1273 * e. 0 -> 4.
1274 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1275 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1276 * the compiled version already exists).
1277 *
1278 * Note that since state 0 can be reached from any other state via deoptimization different loops
1279 * are possible.
1280 *
1281 */
1282
1283 // Common transition function. Given a predicate determines if a method should transition to another level.
1284 template<typename Predicate>
1285 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1286 CompLevel next_level = cur_level;
1287
1288 if (force_comp_at_level_simple(method)) {
1289 next_level = CompLevel_simple;
1290 } else if (is_trivial(method) || method->is_native()) {
1291 // We do not care if there is profiling data for these methods, throw them to compiler.
1292 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1293 } else if (MethodTrainingData::have_data()) {
1294 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1295 if (mtd == nullptr) {
1296 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1297 // Feed it to the standard TF with no profiling delay.
1298 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1299 } else {
1300 next_level = trained_transition(method, cur_level, mtd, THREAD);
1301 if (cur_level == next_level) {
1302 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1303 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1304 // TF but with profiling delay.
1305 next_level = standard_transition<Predicate>(method, cur_level, true /*delay_profiling*/, disable_feedback);
1306 }
1307 }
1308 } else {
1309 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1310 }
1311 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1312 }
1313
1314
1315 template<typename Predicate>
1316 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1317 CompLevel next_level = cur_level;
1318 switch(cur_level) {
1319 default: break;
1320 case CompLevel_none:
1321 next_level = transition_from_none<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1322 break;
1323 case CompLevel_limited_profile:
1324 next_level = transition_from_limited_profile<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1325 break;
1326 case CompLevel_full_profile:
1327 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1328 break;
1329 }
1330 return next_level;
1331 }
1332
1333 template<typename Predicate>
1334 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1335 precond(cur_level == CompLevel_none);
1336 CompLevel next_level = cur_level;
1337 int i = method->invocation_count();
1338 int b = method->backedge_count();
1339 double scale = delay_profiling ? Tier0ProfileDelayFactor : 1.0;
1340 // If we were at full profile level, would we switch to full opt?
1341 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1342 next_level = CompLevel_full_optimization;
1343 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply_scaled(method, cur_level, i, b, scale)) {
1344 // C1-generated fully profiled code is about 30% slower than the limited profile
1345 // code that has only invocation and backedge counters. The observation is that
1346 // if C2 queue is large enough we can spend too much time in the fully profiled code
1347 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1348 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1349 // we choose to compile a limited profiled version and then recompile with full profiling
1350 // when the load on C2 goes down.
1351 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1352 next_level = CompLevel_limited_profile;
1353 } else {
1354 next_level = CompLevel_full_profile;
1355 }
1356 }
1357 return next_level;
1358 }
1359
1360 template<typename Predicate>
1361 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1362 precond(cur_level == CompLevel_full_profile);
1363 CompLevel next_level = cur_level;
1364 MethodData* mdo = method->method_data();
1365 if (mdo != nullptr) {
1366 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1367 int mdo_i = mdo->invocation_count_delta();
1368 int mdo_b = mdo->backedge_count_delta();
1369 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1370 next_level = CompLevel_full_optimization;
1371 }
1372 } else {
1373 next_level = CompLevel_full_optimization;
1374 }
1375 }
1376 return next_level;
1377 }
1378
1379 template<typename Predicate>
1380 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1381 precond(cur_level == CompLevel_limited_profile);
1382 CompLevel next_level = cur_level;
1383 int i = method->invocation_count();
1384 int b = method->backedge_count();
1385 double scale = delay_profiling ? Tier2ProfileDelayFactor : 1.0;
1386 MethodData* mdo = method->method_data();
1387 if (mdo != nullptr) {
1388 if (mdo->would_profile()) {
1389 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1390 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1391 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1392 next_level = CompLevel_full_profile;
1393 }
1394 } else {
1395 next_level = CompLevel_full_optimization;
1396 }
1397 } else {
1398 // If there is no MDO we need to profile
1399 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1400 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1401 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1402 next_level = CompLevel_full_profile;
1403 }
1404 }
1405 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1406 next_level = CompLevel_full_optimization;
1407 }
1408 return next_level;
1409 }
1410
1411
1412 // Determine if a method should be compiled with a normal entry point at a different level.
1413 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1414 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1415 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1416
1417 // If OSR method level is greater than the regular method level, the levels should be
1418 // equalized by raising the regular method level in order to avoid OSRs during each
1419 // invocation of the method.
1420 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1421 MethodData* mdo = method->method_data();
1422 guarantee(mdo != nullptr, "MDO should not be nullptr");
1423 if (mdo->invocation_count() >= 1) {
1424 next_level = CompLevel_full_optimization;
1425 }
1426 } else {
1427 next_level = MAX2(osr_level, next_level);
1428 }
1429 #if INCLUDE_JVMCI
1430 if (EnableJVMCI && UseJVMCICompiler &&
1431 next_level == CompLevel_full_optimization CDS_ONLY(&& !AOTLinkedClassBulkLoader::class_preloading_finished())) {
1432 next_level = cur_level;
1433 }
1434 #endif
1435 return next_level;
1436 }
1437
1438 // Determine if we should do an OSR compilation of a given method.
1439 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1440 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1441 if (cur_level == CompLevel_none) {
1442 // If there is a live OSR method that means that we deopted to the interpreter
1443 // for the transition.
1444 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1445 if (osr_level > CompLevel_none) {
1446 return osr_level;
1447 }
1448 }
1449 return next_level;
1450 }
1451
1452 // Handle the invocation event.
1453 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1454 CompLevel level, nmethod* nm, TRAPS) {
1455 if (should_create_mdo(mh, level)) {
1456 create_mdo(mh, THREAD);
1457 }
1458 CompLevel next_level = call_event(mh, level, THREAD);
1459 if (next_level != level) {
1460 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1461 compile(mh, InvocationEntryBci, next_level, THREAD);
1462 }
1463 }
1464 }
1465
1466 // Handle the back branch event. Notice that we can compile the method
1467 // with a regular entry from here.
1468 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1469 int bci, CompLevel level, nmethod* nm, TRAPS) {
1470 if (should_create_mdo(mh, level)) {
1471 create_mdo(mh, THREAD);
1472 }
1473 // Check if MDO should be created for the inlined method
1474 if (should_create_mdo(imh, level)) {
1475 create_mdo(imh, THREAD);
1476 }
1477
1478 if (is_compilation_enabled()) {
1479 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1480 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1481 // At the very least compile the OSR version
1482 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1483 compile(imh, bci, next_osr_level, CHECK);
1484 }
1485
1486 // Use loop event as an opportunity to also check if there's been
1487 // enough calls.
1488 CompLevel cur_level, next_level;
1489 if (mh() != imh()) { // If there is an enclosing method
1490 {
1491 guarantee(nm != nullptr, "Should have nmethod here");
1492 cur_level = comp_level(mh());
1493 next_level = call_event(mh, cur_level, THREAD);
1494
1495 if (max_osr_level == CompLevel_full_optimization) {
1496 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1497 bool make_not_entrant = false;
1498 if (nm->is_osr_method()) {
1499 // This is an osr method, just make it not entrant and recompile later if needed
1500 make_not_entrant = true;
1501 } else {
1502 if (next_level != CompLevel_full_optimization) {
1503 // next_level is not full opt, so we need to recompile the
1504 // enclosing method without the inlinee
1505 cur_level = CompLevel_none;
1506 make_not_entrant = true;
1507 }
1508 }
1509 if (make_not_entrant) {
1510 if (PrintTieredEvents) {
1511 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1512 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1513 }
1514 nm->make_not_entrant("OSR invalidation, back branch");
1515 }
1516 }
1517 // Fix up next_level if necessary to avoid deopts
1518 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1519 next_level = CompLevel_full_profile;
1520 }
1521 if (cur_level != next_level) {
1522 if (!CompileBroker::compilation_is_in_queue(mh)) {
1523 compile(mh, InvocationEntryBci, next_level, THREAD);
1524 }
1525 }
1526 }
1527 } else {
1528 cur_level = comp_level(mh());
1529 next_level = call_event(mh, cur_level, THREAD);
1530 if (next_level != cur_level) {
1531 if (!CompileBroker::compilation_is_in_queue(mh)) {
1532 compile(mh, InvocationEntryBci, next_level, THREAD);
1533 }
1534 }
1535 }
1536 }
1537 }
1538