1 /*
2 * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotLinkedClassBulkLoader.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "code/scopeDesc.hpp"
28 #include "compiler/compilationPolicy.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "compiler/compilerDefinitions.inline.hpp"
31 #include "compiler/compilerOracle.hpp"
32 #include "compiler/recompilationPolicy.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/method.inline.hpp"
35 #include "oops/methodData.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/trainingData.hpp"
38 #include "prims/jvmtiExport.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/frame.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/globals_extension.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/safepoint.hpp"
46 #include "runtime/safepointVerifiers.hpp"
47 #ifdef COMPILER1
48 #include "c1/c1_Compiler.hpp"
49 #endif
50 #ifdef COMPILER2
51 #include "opto/c2compiler.hpp"
52 #endif
53 #if INCLUDE_JVMCI
54 #include "jvmci/jvmci.hpp"
55 #endif
56
57 int64_t CompilationPolicy::_start_time = 0;
58 int CompilationPolicy::_c1_count = 0;
59 int CompilationPolicy::_c2_count = 0;
60 int CompilationPolicy::_ac_count = 0;
61 double CompilationPolicy::_increase_threshold_at_ratio = 0;
62
63 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
64
65 void compilationPolicy_init() {
66 CompilationPolicy::initialize();
67 }
68
69 int CompilationPolicy::compiler_count(CompLevel comp_level) {
70 if (is_c1_compile(comp_level)) {
71 return c1_count();
72 } else if (is_c2_compile(comp_level)) {
73 return c2_count();
74 }
75 return 0;
76 }
77
78 // Returns true if m must be compiled before executing it
79 // This is intended to force compiles for methods (usually for
80 // debugging) that would otherwise be interpreted for some reason.
81 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
82 // Don't allow Xcomp to cause compiles in replay mode
83 if (ReplayCompiles) return false;
84
85 if (m->has_compiled_code()) return false; // already compiled
86 if (!can_be_compiled(m, comp_level)) return false;
87
88 return !UseInterpreter || // must compile all methods
89 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
90 }
91
92 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
93 if (m->method_holder()->is_not_initialized()) {
94 // 'is_not_initialized' means not only '!is_initialized', but also that
95 // initialization has not been started yet ('!being_initialized')
96 // Do not force compilation of methods in uninitialized classes.
97 return;
98 }
99 if (!m->is_native() && MethodTrainingData::have_data()) {
100 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
101 if (mtd == nullptr) {
102 return; // there is no training data recorded for m
103 }
104 // Consider replacing conservatively compiled AOT Preload code with faster AOT code
105 nmethod* nm = m->code();
106 bool recompile = (nm != nullptr) && nm->preloaded();
107 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
108 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
109 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
110 bool requires_online_compilation = false;
111 CompileTrainingData* ctd = mtd->last_toplevel_compile(next_level);
112 if (ctd != nullptr) {
113 // Can't load normal AOT code - not all dependancies are ready,
114 // request normal compilation
115 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
116 }
117 if (requires_online_compilation && recompile) {
118 // Wait when dependencies are ready to load normal AOT code
119 // if AOT Preload code is used now.
120 //
121 // FIXME. We may never (or it take long time) get all dependencies
122 // be ready to replace AOT Preload code. Consider using time and how many
123 // dependencies left to allow normal JIT compilation for replacement.
124 return;
125 }
126 if (PrintTieredEvents) {
127 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
128 }
129 CompileBroker::compile_method(m, InvocationEntryBci, next_level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
130 if (HAS_PENDING_EXCEPTION) {
131 CLEAR_PENDING_EXCEPTION;
132 }
133 }
134 }
135 }
136
137 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
138 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
139 // don't force compilation, resolve was on behalf of compiler
140 return;
141 }
142 if (m->method_holder()->is_not_initialized()) {
143 // 'is_not_initialized' means not only '!is_initialized', but also that
144 // initialization has not been started yet ('!being_initialized')
145 // Do not force compilation of methods in uninitialized classes.
146 // Note that doing this would throw an assert later,
147 // in CompileBroker::compile_method.
148 // We sometimes use the link resolver to do reflective lookups
149 // even before classes are initialized.
150 return;
151 }
152
153 if (must_be_compiled(m)) {
154 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
155 CompLevel level = initial_compile_level(m);
156 if (PrintTieredEvents) {
157 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
158 }
159 // Test AOT code too
160 bool requires_online_compilation = false;
161 if (TrainingData::have_data()) {
162 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
163 if (mtd != nullptr) {
164 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
165 if (ctd != nullptr) {
166 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
167 }
168 }
169 }
170 CompileBroker::compile_method(m, InvocationEntryBci, level, 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
171 }
172 }
173
174 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, JavaThread* current) {
175 if (!klass->has_init_deps_processed()) {
176 ResourceMark rm;
177 log_debug(training)("Replay training: %s", klass->external_name());
178
179 KlassTrainingData* ktd = KlassTrainingData::find(klass);
180 if (ktd != nullptr) {
181 guarantee(ktd->has_holder(), "");
182 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
183 assert(klass->has_init_deps_processed(), "");
184
185 if (AOTCompileEagerly) {
186 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
187 if (ctd->init_deps_left_acquire() == 0) {
188 MethodTrainingData* mtd = ctd->method();
189 if (mtd->has_holder()) {
190 const methodHandle mh(current, const_cast<Method*>(mtd->holder()));
191 CompilationPolicy::maybe_compile_early(mh, current);
192 }
193 }
194 });
195 }
196 }
197 }
198 }
199
200 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, JavaThread* current) {
201 assert(klass->is_initialized(), "");
202 if (TrainingData::have_data() && klass->in_aot_cache()) {
203 _training_replay_queue.push(klass, TrainingReplayQueue_lock, current);
204 }
205 }
206
207 // For TrainingReplayQueue
208 template<>
209 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
210 int pos = 0;
211 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
212 ResourceMark rm;
213 InstanceKlass* ik = cur->value();
214 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
215 }
216 }
217
218 void CompilationPolicy::replay_training_at_init_loop(JavaThread* current) {
219 while (!CompileBroker::is_compilation_disabled_forever()) {
220 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, current);
221 if (ik != nullptr) {
222 replay_training_at_init_impl(ik, current);
223 }
224 }
225 }
226
227 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
228 if (comp_level == CompLevel_any) {
229 if (CompilerConfig::is_c1_only()) {
230 comp_level = CompLevel_simple;
231 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
232 comp_level = CompLevel_full_optimization;
233 }
234 }
235 return comp_level;
236 }
237
238 // Returns true if m is allowed to be compiled
239 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
240 // allow any levels for WhiteBox
241 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
242
243 if (m->is_abstract()) return false;
244 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
245
246 // Math intrinsics should never be compiled as this can lead to
247 // monotonicity problems because the interpreter will prefer the
248 // compiled code to the intrinsic version. This can't happen in
249 // production because the invocation counter can't be incremented
250 // but we shouldn't expose the system to this problem in testing
251 // modes.
252 if (!AbstractInterpreter::can_be_compiled(m)) {
253 return false;
254 }
255 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
256 if (comp_level == CompLevel_any || is_compile(comp_level)) {
257 return !m->is_not_compilable(comp_level);
258 }
259 return false;
260 }
261
262 // Returns true if m is allowed to be osr compiled
263 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
264 bool result = false;
265 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
266 if (comp_level == CompLevel_any || is_compile(comp_level)) {
267 result = !m->is_not_osr_compilable(comp_level);
268 }
269 return (result && can_be_compiled(m, comp_level));
270 }
271
272 bool CompilationPolicy::is_compilation_enabled() {
273 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
274 return CompileBroker::should_compile_new_jobs();
275 }
276
277 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
278 // Remove unloaded methods from the queue
279 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
280 CompileTask* next = task->next();
281 if (task->is_unloaded()) {
282 compile_queue->remove_and_mark_stale(task);
283 }
284 task = next;
285 }
286 #if INCLUDE_JVMCI
287 if (UseJVMCICompiler && !BackgroundCompilation) {
288 /*
289 * In blocking compilation mode, the CompileBroker will make
290 * compilations submitted by a JVMCI compiler thread non-blocking. These
291 * compilations should be scheduled after all blocking compilations
292 * to service non-compiler related compilations sooner and reduce the
293 * chance of such compilations timing out.
294 */
295 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
296 if (task->is_blocking()) {
297 return task;
298 }
299 }
300 }
301 #endif
302 return compile_queue->first();
303 }
304
305 // Simple methods are as good being compiled with C1 as C2.
306 // Determine if a given method is such a case.
307 bool CompilationPolicy::is_trivial(const methodHandle& method) {
308 if (method->is_accessor() ||
309 method->is_constant_getter()) {
310 return true;
311 }
312 return false;
313 }
314
315 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
316 if (CompilationModeFlag::quick_internal()) {
317 #if INCLUDE_JVMCI
318 if (UseJVMCICompiler) {
319 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
320 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
321 return true;
322 }
323 }
324 #endif
325 }
326 return false;
327 }
328
329 CompLevel CompilationPolicy::comp_level(Method* method) {
330 nmethod *nm = method->code();
331 if (nm != nullptr && nm->is_in_use()) {
332 return (CompLevel)nm->comp_level();
333 }
334 return CompLevel_none;
335 }
336
337 // Call and loop predicates determine whether a transition to a higher
338 // compilation level should be performed (pointers to predicate functions
339 // are passed to common()).
340 // Tier?LoadFeedback is basically a coefficient that determines of
341 // how many methods per compiler thread can be in the queue before
342 // the threshold values double.
343 class LoopPredicate : AllStatic {
344 public:
345 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
346 double threshold_scaling;
347 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
348 scale *= threshold_scaling;
349 }
350 switch(cur_level) {
351 case CompLevel_none:
352 case CompLevel_limited_profile:
353 return b >= Tier3BackEdgeThreshold * scale;
354 case CompLevel_full_profile:
355 return b >= Tier4BackEdgeThreshold * scale;
356 default:
357 return true;
358 }
359 }
360
361 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
362 double k = 1;
363 switch(cur_level) {
364 case CompLevel_none:
365 // Fall through
366 case CompLevel_limited_profile: {
367 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
368 break;
369 }
370 case CompLevel_full_profile: {
371 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
372 break;
373 }
374 default:
375 return true;
376 }
377 return apply_scaled(method, cur_level, i, b, k);
378 }
379 };
380
381 class CallPredicate : AllStatic {
382 public:
383 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
384 double threshold_scaling;
385 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
386 scale *= threshold_scaling;
387 }
388 switch(cur_level) {
389 case CompLevel_none:
390 case CompLevel_limited_profile:
391 return (i >= Tier3InvocationThreshold * scale) ||
392 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
393 case CompLevel_full_profile:
394 return (i >= Tier4InvocationThreshold * scale) ||
395 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
396 default:
397 return true;
398 }
399 }
400
401 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
402 double k = 1;
403 switch(cur_level) {
404 case CompLevel_none:
405 case CompLevel_limited_profile: {
406 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
407 break;
408 }
409 case CompLevel_full_profile: {
410 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
411 break;
412 }
413 default:
414 return true;
415 }
416 return apply_scaled(method, cur_level, i, b, k);
417 }
418 };
419
420 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
421 int comp_count = compiler_count(level);
422 if (comp_count > 0 && feedback_k > 0) {
423 double queue_size = CompileBroker::queue_size(level);
424 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
425
426 // Increase C1 compile threshold when the code cache is filled more
427 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
428 // The main intention is to keep enough free space for C2 compiled code
429 // to achieve peak performance if the code cache is under stress.
430 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
431 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
432 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
433 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
434 }
435 }
436 return k;
437 }
438 return 1;
439 }
440
441 void CompilationPolicy::print_counters_on(outputStream* st, const char* prefix, Method* m) {
442 int invocation_count = m->invocation_count();
443 int backedge_count = m->backedge_count();
444 MethodData* mdh = m->method_data();
445 int mdo_invocations = 0, mdo_backedges = 0;
446 int mdo_invocations_start = 0, mdo_backedges_start = 0;
447 if (mdh != nullptr) {
448 mdo_invocations = mdh->invocation_count();
449 mdo_backedges = mdh->backedge_count();
450 mdo_invocations_start = mdh->invocation_count_start();
451 mdo_backedges_start = mdh->backedge_count_start();
452 }
453 st->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
454 invocation_count, backedge_count, prefix,
455 mdo_invocations, mdo_invocations_start,
456 mdo_backedges, mdo_backedges_start);
457 st->print(" %smax levels=%d,%d", prefix, m->highest_comp_level(), m->highest_osr_comp_level());
458 }
459
460 void CompilationPolicy::print_training_data_on(outputStream* st, const char* prefix, Method* method, CompLevel cur_level) {
461 methodHandle m(Thread::current(), method);
462 st->print(" %smtd: ", prefix);
463 MethodTrainingData* mtd = MethodTrainingData::find(m);
464 if (mtd == nullptr) {
465 st->print("null");
466 } else {
467 if (should_delay_standard_transition(m, cur_level, mtd)) {
468 st->print("delayed, ");
469 }
470 MethodData* md = mtd->final_profile();
471 st->print("mdo=");
472 if (md == nullptr) {
473 st->print("null");
474 } else {
475 int mdo_invocations = md->invocation_count();
476 int mdo_backedges = md->backedge_count();
477 int mdo_invocations_start = md->invocation_count_start();
478 int mdo_backedges_start = md->backedge_count_start();
479 st->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
480 }
481 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
482 st->print(", deps=");
483 if (ctd == nullptr) {
484 st->print("null");
485 } else {
486 st->print("%d", ctd->init_deps_left_acquire());
487 }
488 }
489 }
490
491 // Print an event.
492 void CompilationPolicy::print_event_on(outputStream *st, EventType type, Method* m, Method* im, int bci, CompLevel level) {
493 bool inlinee_event = m != im;
494
495 st->print("%lf: [", os::elapsedTime());
496
497 switch(type) {
498 case CALL:
499 st->print("call");
500 break;
501 case LOOP:
502 st->print("loop");
503 break;
504 case COMPILE:
505 st->print("compile");
506 break;
507 case FORCE_COMPILE:
508 st->print("force-compile");
509 break;
510 case FORCE_RECOMPILE:
511 st->print("force-recompile");
512 break;
513 case REMOVE_FROM_QUEUE:
514 st->print("remove-from-queue");
515 break;
516 case UPDATE_IN_QUEUE:
517 st->print("update-in-queue");
518 break;
519 case REPROFILE:
520 st->print("reprofile");
521 break;
522 case MAKE_NOT_ENTRANT:
523 st->print("make-not-entrant");
524 break;
525 default:
526 st->print("unknown");
527 }
528
529 st->print(" level=%d ", level);
530
531 ResourceMark rm;
532 char *method_name = m->name_and_sig_as_C_string();
533 st->print("[%s", method_name);
534 if (inlinee_event) {
535 char *inlinee_name = im->name_and_sig_as_C_string();
536 st->print(" [%s]] ", inlinee_name);
537 }
538 else st->print("] ");
539 st->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
540 CompileBroker::queue_size(CompLevel_full_optimization));
541
542 st->print(" rate=");
543 if (m->prev_time() == 0) st->print("n/a");
544 else st->print("%f", m->rate());
545
546 RecompilationPolicy::print_load_average(st);
547
548 st->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
549 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
550
551 if (type != COMPILE) {
552 print_counters_on(st, "", m);
553 if (inlinee_event) {
554 print_counters_on(st, "inlinee ", im);
555 }
556 st->print(" compilable=");
557 bool need_comma = false;
558 if (!m->is_not_compilable(CompLevel_full_profile)) {
559 st->print("c1");
560 need_comma = true;
561 }
562 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
563 if (need_comma) st->print(",");
564 st->print("c1-osr");
565 need_comma = true;
566 }
567 if (!m->is_not_compilable(CompLevel_full_optimization)) {
568 if (need_comma) st->print(",");
569 st->print("c2");
570 need_comma = true;
571 }
572 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
573 if (need_comma) st->print(",");
574 st->print("c2-osr");
575 }
576 st->print(" status=");
577 if (m->queued_for_compilation()) {
578 st->print("in-queue");
579 } else st->print("idle");
580
581 print_training_data_on(st, "", m, level);
582 if (inlinee_event) {
583 print_training_data_on(st, "inlinee ", im, level);
584 }
585 }
586 st->print_cr("]");
587
588 }
589
590 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
591 stringStream s;
592 print_event_on(&s, type, m, im, bci, level);
593 ResourceMark rm;
594 tty->print("%s", s.as_string());
595 }
596
597 void CompilationPolicy::initialize() {
598 if (!CompilerConfig::is_interpreter_only()) {
599 int count = CICompilerCount;
600 bool c1_only = CompilerConfig::is_c1_only();
601 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
602 int min_count = (c1_only || c2_only) ? 1 : 2;
603
604 #ifdef _LP64
605 // Turn on ergonomic compiler count selection
606 if (AOTCodeCache::maybe_dumping_code()) {
607 // Assembly phase runs C1 and C2 compilation in separate phases,
608 // and can use all the CPU threads it can reach. Adjust the common
609 // options before policy starts overwriting them.
610 FLAG_SET_ERGO_IF_DEFAULT(UseDynamicNumberOfCompilerThreads, false);
611 FLAG_SET_ERGO_IF_DEFAULT(CICompilerCountPerCPU, false);
612 if (FLAG_IS_DEFAULT(CICompilerCount)) {
613 count = MAX2(count, os::active_processor_count());
614 }
615 }
616 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
617 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
618 }
619 if (CICompilerCountPerCPU) {
620 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
621 int log_cpu = log2i(os::active_processor_count());
622 int loglog_cpu = log2i(MAX2(log_cpu, 1));
623 count = MAX2(log_cpu * loglog_cpu * 3 / 2, min_count);
624 }
625 if (FLAG_IS_DEFAULT(CICompilerCount)) {
626 // Make sure there is enough space in the code cache to hold all the compiler buffers
627 size_t c1_size = 0;
628 #ifdef COMPILER1
629 c1_size = Compiler::code_buffer_size();
630 #endif
631 size_t c2_size = 0;
632 #ifdef COMPILER2
633 c2_size = C2Compiler::initial_code_buffer_size();
634 #endif
635 size_t buffer_size = 0;
636 if (c1_only) {
637 buffer_size = c1_size;
638 } else if (c2_only) {
639 buffer_size = c2_size;
640 } else {
641 buffer_size = c1_size / 3 + 2 * c2_size / 3;
642 }
643 size_t max_count = (NonNMethodCodeHeapSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / buffer_size;
644 if ((size_t)count > max_count) {
645 // Lower the compiler count such that all buffers fit into the code cache
646 count = MAX2((int)max_count, min_count);
647 }
648 FLAG_SET_ERGO(CICompilerCount, count);
649 }
650 #else
651 // On 32-bit systems, the number of compiler threads is limited to 3.
652 // On these systems, the virtual address space available to the JVM
653 // is usually limited to 2-4 GB (the exact value depends on the platform).
654 // As the compilers (especially C2) can consume a large amount of
655 // memory, scaling the number of compiler threads with the number of
656 // available cores can result in the exhaustion of the address space
657 /// available to the VM and thus cause the VM to crash.
658 if (FLAG_IS_DEFAULT(CICompilerCount)) {
659 count = 3;
660 FLAG_SET_ERGO(CICompilerCount, count);
661 }
662 #endif // _LP64
663
664 if (c1_only) {
665 // No C2 compiler threads are needed
666 set_c1_count(count);
667 } else if (c2_only) {
668 // No C1 compiler threads are needed
669 set_c2_count(count);
670 } else {
671 #if INCLUDE_JVMCI
672 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
673 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
674 int c1_count = MAX2(count - libjvmci_count, 1);
675 set_c2_count(libjvmci_count);
676 set_c1_count(c1_count);
677 } else
678 #endif
679 {
680 set_c1_count(MAX2(count / 3, 1));
681 set_c2_count(MAX2(count - c1_count(), 1));
682 }
683 }
684 if (AOTCodeCache::is_code_load_thread_on()) {
685 set_ac_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 AOT code in parallel
686 }
687 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
688 set_increase_threshold_at_ratio();
689 } else {
690 // Interpreter mode creates no compilers
691 FLAG_SET_ERGO(CICompilerCount, 0);
692 }
693 set_start_time(nanos_to_millis(os::javaTimeNanos()));
694 }
695
696
697 #ifdef ASSERT
698 bool CompilationPolicy::verify_level(CompLevel level) {
699 if (TieredCompilation && level > TieredStopAtLevel) {
700 return false;
701 }
702 // Check if there is a compiler to process the requested level
703 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
704 return false;
705 }
706 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
707 return false;
708 }
709
710 // Interpreter level is always valid.
711 if (level == CompLevel_none) {
712 return true;
713 }
714 if (CompilationModeFlag::normal()) {
715 return true;
716 } else if (CompilationModeFlag::quick_only()) {
717 return level == CompLevel_simple;
718 } else if (CompilationModeFlag::high_only()) {
719 return level == CompLevel_full_optimization;
720 } else if (CompilationModeFlag::high_only_quick_internal()) {
721 return level == CompLevel_full_optimization || level == CompLevel_simple;
722 }
723 return false;
724 }
725 #endif
726
727
728 CompLevel CompilationPolicy::highest_compile_level() {
729 CompLevel level = CompLevel_none;
730 // Setup the maximum level available for the current compiler configuration.
731 if (!CompilerConfig::is_interpreter_only()) {
732 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
733 level = CompLevel_full_optimization;
734 } else if (CompilerConfig::is_c1_enabled()) {
735 if (CompilerConfig::is_c1_simple_only()) {
736 level = CompLevel_simple;
737 } else {
738 level = CompLevel_full_profile;
739 }
740 }
741 }
742 // Clamp the maximum level with TieredStopAtLevel.
743 if (TieredCompilation) {
744 level = MIN2(level, (CompLevel) TieredStopAtLevel);
745 }
746
747 // Fix it up if after the clamping it has become invalid.
748 // Bring it monotonically down depending on the next available level for
749 // the compilation mode.
750 if (!CompilationModeFlag::normal()) {
751 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
752 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
753 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
754 if (CompilationModeFlag::quick_only()) {
755 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
756 level = CompLevel_simple;
757 }
758 } else if (CompilationModeFlag::high_only()) {
759 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
760 level = CompLevel_none;
761 }
762 } else if (CompilationModeFlag::high_only_quick_internal()) {
763 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
764 level = CompLevel_simple;
765 }
766 }
767 }
768
769 assert(verify_level(level), "Invalid highest compilation level: %d", level);
770 return level;
771 }
772
773 CompLevel CompilationPolicy::limit_level(CompLevel level) {
774 level = MIN2(level, highest_compile_level());
775 assert(verify_level(level), "Invalid compilation level: %d", level);
776 return level;
777 }
778
779 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
780 CompLevel level = CompLevel_any;
781 if (CompilationModeFlag::normal()) {
782 level = CompLevel_full_profile;
783 } else if (CompilationModeFlag::quick_only()) {
784 level = CompLevel_simple;
785 } else if (CompilationModeFlag::high_only()) {
786 level = CompLevel_full_optimization;
787 } else if (CompilationModeFlag::high_only_quick_internal()) {
788 if (force_comp_at_level_simple(method)) {
789 level = CompLevel_simple;
790 } else {
791 level = CompLevel_full_optimization;
792 }
793 }
794 assert(level != CompLevel_any, "Unhandled compilation mode");
795 return limit_level(level);
796 }
797
798 // Set carry flags on the counters if necessary
799 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
800 MethodCounters *mcs = method->method_counters();
801 if (mcs != nullptr) {
802 mcs->invocation_counter()->set_carry_on_overflow();
803 mcs->backedge_counter()->set_carry_on_overflow();
804 }
805 MethodData* mdo = method->method_data();
806 if (mdo != nullptr) {
807 mdo->invocation_counter()->set_carry_on_overflow();
808 mdo->backedge_counter()->set_carry_on_overflow();
809 }
810 }
811
812 // Called with the queue locked and with at least one element
813 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
814 CompileTask *max_blocking_task = nullptr;
815 CompileTask *max_task = nullptr;
816 Method* max_method = nullptr;
817
818 int64_t t = nanos_to_millis(os::javaTimeNanos());
819 // Iterate through the queue and find a method with a maximum rate.
820 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
821 CompileTask* next_task = task->next();
822 // If a method was unloaded or has been stale for some time, remove it from the queue.
823 // Blocking tasks and tasks submitted from whitebox API don't become stale
824 if (task->is_unloaded()) {
825 compile_queue->remove_and_mark_stale(task);
826 task = next_task;
827 continue;
828 }
829 if (task->is_aot_load()) {
830 // AOTCodeCache tasks are on separate queue, and they should load fast. There is no need to walk
831 // the rest of the queue, just take the task and go.
832 return task;
833 }
834 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
835 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
836 // selection and/or any level adjustments. Just return them in order.
837 return task;
838 }
839 Method* method = task->method();
840 methodHandle mh(THREAD, method);
841 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
842 if (PrintTieredEvents) {
843 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
844 }
845 method->clear_queued_for_compilation();
846 method->set_pending_queue_processed(false);
847 compile_queue->remove_and_mark_stale(task);
848 task = next_task;
849 continue;
850 }
851 update_rate(t, mh);
852 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
853 // Select a method with the highest rate
854 max_task = task;
855 max_method = method;
856 }
857
858 if (task->is_blocking()) {
859 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
860 max_blocking_task = task;
861 }
862 }
863
864 task = next_task;
865 }
866
867 if (max_blocking_task != nullptr) {
868 // In blocking compilation mode, the CompileBroker will make
869 // compilations submitted by a JVMCI compiler thread non-blocking. These
870 // compilations should be scheduled after all blocking compilations
871 // to service non-compiler related compilations sooner and reduce the
872 // chance of such compilations timing out.
873 max_task = max_blocking_task;
874 max_method = max_task->method();
875 }
876
877 methodHandle max_method_h(THREAD, max_method);
878
879 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
880 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
881 max_task->set_comp_level(CompLevel_limited_profile);
882
883 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
884 false /* requires_online_compilation */,
885 CompileTask::Reason_None)) {
886 if (PrintTieredEvents) {
887 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
888 }
889 compile_queue->remove_and_mark_stale(max_task);
890 max_method->clear_queued_for_compilation();
891 return nullptr;
892 }
893
894 if (PrintTieredEvents) {
895 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
896 }
897 }
898
899 return max_task;
900 }
901
902 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
903 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
904 if (PrintTieredEvents) {
905 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
906 }
907 MethodData* mdo = sd->method()->method_data();
908 if (mdo != nullptr) {
909 mdo->reset_start_counters();
910 }
911 if (sd->is_top()) break;
912 }
913 }
914
915 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
916 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
917 if (PrintTieredEvents) {
918 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
919 }
920
921 if (comp_level == CompLevel_none &&
922 JvmtiExport::can_post_interpreter_events() &&
923 THREAD->is_interp_only_mode()) {
924 return nullptr;
925 }
926 if (ReplayCompiles) {
927 // Don't trigger other compiles in testing mode
928 return nullptr;
929 }
930
931 handle_counter_overflow(method);
932 if (method() != inlinee()) {
933 handle_counter_overflow(inlinee);
934 }
935
936 if (bci == InvocationEntryBci) {
937 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
938 } else {
939 // method == inlinee if the event originated in the main method
940 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
941 // Check if event led to a higher level OSR compilation
942 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
943 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
944 // It's not possible to reach the expected level so fall back to simple.
945 expected_comp_level = CompLevel_simple;
946 }
947 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
948 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
949 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
950 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
951 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
952 // Perform OSR with new nmethod
953 return osr_nm;
954 }
955 }
956 }
957 return nullptr;
958 }
959
960 // Check if the method can be compiled, change level if necessary
961 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
962 assert(verify_level(level), "Invalid compilation level requested: %d", level);
963
964 if (level == CompLevel_none) {
965 if (mh->has_compiled_code()) {
966 // Happens when we switch to interpreter to profile.
967 MutexLocker ml(Compile_lock);
968 NoSafepointVerifier nsv;
969 if (mh->has_compiled_code()) {
970 mh->code()->make_not_used();
971 }
972 // Deoptimize immediately (we don't have to wait for a compile).
973 JavaThread* jt = THREAD;
974 RegisterMap map(jt,
975 RegisterMap::UpdateMap::skip,
976 RegisterMap::ProcessFrames::include,
977 RegisterMap::WalkContinuation::skip);
978 frame fr = jt->last_frame().sender(&map);
979 Deoptimization::deoptimize_frame(jt, fr.id());
980 }
981 return;
982 }
983
984 // Check if the method can be compiled. Additional logic for TieredCompilation:
985 // If it cannot be compiled with C1, continue profiling in the interpreter
986 // and then compile with C2 (the transition function will request that,
987 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
988 // pure C1.
989 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
990 if (!CompilationModeFlag::disable_intermediate() &&
991 level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
992 compile(mh, bci, CompLevel_simple, THREAD);
993 }
994 return;
995 }
996 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
997 if (!CompilationModeFlag::disable_intermediate() &&
998 level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
999 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
1000 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
1001 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
1002 osr_nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_FOR_COMPILING_WITH_C1);
1003 }
1004 compile(mh, bci, CompLevel_simple, THREAD);
1005 }
1006 return;
1007 }
1008 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
1009 return;
1010 }
1011 if (!CompileBroker::compilation_is_in_queue(mh)) {
1012 if (PrintTieredEvents) {
1013 print_event(COMPILE, mh(), mh(), bci, level);
1014 }
1015 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
1016 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
1017 bool requires_online_compilation = false;
1018 if (TrainingData::have_data()) {
1019 MethodTrainingData* mtd = MethodTrainingData::find_fast(mh);
1020 if (mtd != nullptr) {
1021 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
1022 if (ctd != nullptr) {
1023 requires_online_compilation = (ctd->init_deps_left_acquire() > 0);
1024 }
1025 }
1026 }
1027 CompileBroker::compile_method(mh, bci, level, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
1028 }
1029 }
1030
1031 // update_rate() is called from select_task() while holding a compile queue lock.
1032 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
1033 // Skip update if counters are absent.
1034 // Can't allocate them since we are holding compile queue lock.
1035 if (method->method_counters() == nullptr) return;
1036
1037 if (is_old(method)) {
1038 // We don't remove old methods from the queue,
1039 // so we can just zero the rate.
1040 method->set_rate(0);
1041 return;
1042 }
1043
1044 // We don't update the rate if we've just came out of a safepoint.
1045 // delta_s is the time since last safepoint in milliseconds.
1046 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1047 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1048 // How many events were there since the last time?
1049 int event_count = method->invocation_count() + method->backedge_count();
1050 int delta_e = event_count - method->prev_event_count();
1051
1052 // We should be running for at least 1ms.
1053 if (delta_s >= TieredRateUpdateMinTime) {
1054 // And we must've taken the previous point at least 1ms before.
1055 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1056 method->set_prev_time(t);
1057 method->set_prev_event_count(event_count);
1058 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1059 } else {
1060 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1061 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1062 method->set_rate(0);
1063 }
1064 }
1065 }
1066 }
1067
1068 // Check if this method has been stale for a given number of milliseconds.
1069 // See select_task().
1070 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1071 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1072 int64_t delta_t = t - method->prev_time();
1073 if (delta_t > timeout && delta_s > timeout) {
1074 int event_count = method->invocation_count() + method->backedge_count();
1075 int delta_e = event_count - method->prev_event_count();
1076 // Return true if there were no events.
1077 return delta_e == 0;
1078 }
1079 return false;
1080 }
1081
1082 // We don't remove old methods from the compile queue even if they have
1083 // very low activity. See select_task().
1084 bool CompilationPolicy::is_old(const methodHandle& method) {
1085 int i = method->invocation_count();
1086 int b = method->backedge_count();
1087 double k = TieredOldPercentage / 100.0;
1088
1089 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1090 }
1091
1092 double CompilationPolicy::weight(Method* method) {
1093 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1094 }
1095
1096 // Apply heuristics and return true if x should be compiled before y
1097 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1098 if (x->highest_comp_level() > y->highest_comp_level()) {
1099 // recompilation after deopt
1100 return true;
1101 } else
1102 if (x->highest_comp_level() == y->highest_comp_level()) {
1103 if (weight(x) > weight(y)) {
1104 return true;
1105 }
1106 }
1107 return false;
1108 }
1109
1110 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1111 assert(!x->is_aot_load() && !y->is_aot_load(), "AOT code caching tasks are not expected here");
1112 if (x->compile_reason() != y->compile_reason() && y->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1113 return true;
1114 }
1115 return false;
1116 }
1117
1118 // Is method profiled enough?
1119 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1120 MethodData* mdo = method->method_data();
1121 if (mdo != nullptr) {
1122 int i = mdo->invocation_count_delta();
1123 int b = mdo->backedge_count_delta();
1124 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1125 }
1126 return false;
1127 }
1128
1129
1130 // Determine is a method is mature.
1131 bool CompilationPolicy::is_mature(MethodData* mdo) {
1132 if (Arguments::is_compiler_only()) {
1133 // Always report profiles as immature with -Xcomp
1134 return false;
1135 }
1136 methodHandle mh(Thread::current(), mdo->method());
1137 if (mdo != nullptr) {
1138 int i = mdo->invocation_count();
1139 int b = mdo->backedge_count();
1140 double k = ProfileMaturityPercentage / 100.0;
1141 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1142 }
1143 return false;
1144 }
1145
1146 // If a method is old enough and is still in the interpreter we would want to
1147 // start profiling without waiting for the compiled method to arrive.
1148 // We also take the load on compilers into the account.
1149 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1150 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1151 return false;
1152 }
1153
1154 if (TrainingData::have_data()) {
1155 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1156 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1157 return true;
1158 }
1159 }
1160
1161 if (is_old(method)) {
1162 return true;
1163 }
1164 int i = method->invocation_count();
1165 int b = method->backedge_count();
1166 double k = Tier0ProfilingStartPercentage / 100.0;
1167
1168 // If the top level compiler is not keeping up, delay profiling.
1169 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1170 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1171 }
1172 return false;
1173 }
1174
1175 // Inlining control: if we're compiling a profiled method with C1 and the callee
1176 // is known to have OSRed in a C2 version, don't inline it.
1177 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1178 CompLevel comp_level = (CompLevel)env->comp_level();
1179 if (comp_level == CompLevel_full_profile ||
1180 comp_level == CompLevel_limited_profile) {
1181 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1182 }
1183 return false;
1184 }
1185
1186 // Create MDO if necessary.
1187 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1188 if (mh->is_native() ||
1189 mh->is_abstract() ||
1190 mh->is_accessor() ||
1191 mh->is_constant_getter()) {
1192 return;
1193 }
1194 if (mh->method_data() == nullptr) {
1195 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1196 }
1197 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1198 MethodData* mdo = mh->method_data();
1199 if (mdo != nullptr) {
1200 frame last_frame = THREAD->last_frame();
1201 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1202 int bci = last_frame.interpreter_frame_bci();
1203 address dp = mdo->bci_to_dp(bci);
1204 last_frame.interpreter_frame_set_mdp(dp);
1205 }
1206 }
1207 }
1208 }
1209
1210 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1211 precond(mtd != nullptr);
1212 precond(cur_level == CompLevel_none);
1213
1214 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1215 return CompLevel_none;
1216 }
1217
1218 bool training_has_profile = (mtd->final_profile() != nullptr);
1219 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1220 return CompLevel_full_profile;
1221 }
1222
1223 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1224 switch (highest_training_level) {
1225 case CompLevel_limited_profile:
1226 case CompLevel_full_profile:
1227 return CompLevel_limited_profile;
1228 case CompLevel_simple:
1229 return CompLevel_simple;
1230 case CompLevel_none:
1231 return CompLevel_none;
1232 default:
1233 break;
1234 }
1235
1236 // Now handle the case of level 4.
1237 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1238 if (!training_has_profile) {
1239 // The method was a part of a level 4 compile, but doesn't have a stored profile,
1240 // we need to profile it.
1241 return CompLevel_full_profile;
1242 }
1243 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1244 // If we deopted, then we reprofile
1245 if (deopt && !is_method_profiled(method)) {
1246 return CompLevel_full_profile;
1247 }
1248
1249 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1250 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1251 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1252 if (SkipTier2IfPossible && ctd->init_deps_left_acquire() == 0) {
1253 if (method->method_data() == nullptr) {
1254 create_mdo(method, THREAD);
1255 }
1256 return CompLevel_full_optimization;
1257 }
1258
1259 // Otherwise go to level 2
1260 return CompLevel_limited_profile;
1261 }
1262
1263
1264 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1265 precond(mtd != nullptr);
1266 precond(cur_level == CompLevel_limited_profile);
1267
1268 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1269
1270 // But first, check if we have a saved profile
1271 bool training_has_profile = (mtd->final_profile() != nullptr);
1272 if (!training_has_profile) {
1273 return CompLevel_full_profile;
1274 }
1275
1276
1277 assert(training_has_profile, "Have to have a profile to be here");
1278 // Check if the method is ready
1279 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1280 if (ctd != nullptr && ctd->init_deps_left_acquire() == 0) {
1281 if (method->method_data() == nullptr) {
1282 create_mdo(method, THREAD);
1283 }
1284 return CompLevel_full_optimization;
1285 }
1286
1287 // Otherwise stay at the current level
1288 return CompLevel_limited_profile;
1289 }
1290
1291
1292 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1293 precond(mtd != nullptr);
1294 precond(cur_level == CompLevel_full_profile);
1295
1296 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1297 // We have method at the full profile level and we also know that it's possibly an important method.
1298 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1299 // Check if it is adequately profiled
1300 if (is_method_profiled(method)) {
1301 return CompLevel_full_optimization;
1302 }
1303 }
1304
1305 // Otherwise stay at the current level
1306 return CompLevel_full_profile;
1307 }
1308
1309 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1310 precond(MethodTrainingData::have_data());
1311
1312 // If there is no training data recorded for this method, bail out.
1313 if (mtd == nullptr) {
1314 return cur_level;
1315 }
1316
1317 CompLevel next_level = cur_level;
1318 switch(cur_level) {
1319 default: break;
1320 case CompLevel_none:
1321 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1322 break;
1323 case CompLevel_limited_profile:
1324 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1325 break;
1326 case CompLevel_full_profile:
1327 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1328 break;
1329 }
1330
1331 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1332 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1333 return CompLevel_none;
1334 }
1335 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1336 return CompLevel_none;
1337 }
1338 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1339 }
1340
1341 /*
1342 * Method states:
1343 * 0 - interpreter (CompLevel_none)
1344 * 1 - pure C1 (CompLevel_simple)
1345 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1346 * 3 - C1 with full profiling (CompLevel_full_profile)
1347 * 4 - C2 or Graal (CompLevel_full_optimization)
1348 *
1349 * Common state transition patterns:
1350 * a. 0 -> 3 -> 4.
1351 * The most common path. But note that even in this straightforward case
1352 * profiling can start at level 0 and finish at level 3.
1353 *
1354 * b. 0 -> 2 -> 3 -> 4.
1355 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1356 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1357 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1358 *
1359 * c. 0 -> (3->2) -> 4.
1360 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1361 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1362 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1363 * without full profiling while c2 is compiling.
1364 *
1365 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1366 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1367 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1368 *
1369 * e. 0 -> 4.
1370 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1371 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1372 * the compiled version already exists).
1373 *
1374 * Note that since state 0 can be reached from any other state via deoptimization different loops
1375 * are possible.
1376 *
1377 */
1378
1379 // Common transition function. Given a predicate determines if a method should transition to another level.
1380 template<typename Predicate>
1381 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1382 CompLevel next_level = cur_level;
1383
1384 if (force_comp_at_level_simple(method)) {
1385 next_level = CompLevel_simple;
1386 } else if (is_trivial(method) || method->is_native()) {
1387 // We do not care if there is profiling data for these methods, throw them to compiler.
1388 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1389 } else if (MethodTrainingData::have_data()) {
1390 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1391 if (mtd == nullptr) {
1392 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1393 // Feed it to the standard TF with no profiling delay.
1394 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1395 } else {
1396 next_level = trained_transition(method, cur_level, mtd, THREAD);
1397 if (cur_level == next_level && !should_delay_standard_transition(method, cur_level, mtd)) {
1398 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1399 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1400 // TF but with profiling delay.
1401 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1402 }
1403 }
1404 } else {
1405 next_level = standard_transition<Predicate>(method, cur_level, disable_feedback);
1406 }
1407 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1408 }
1409
1410 bool CompilationPolicy::should_delay_standard_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd) {
1411 precond(mtd != nullptr);
1412 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1413 if (highest_training_level != CompLevel_full_optimization && cur_level == CompLevel_limited_profile) {
1414 // This is a lukewarm method - it hasn't been compiled with C2 during the tranining run and is currently
1415 // running at level 2. Delay any further state changes until its counters exceed the training run counts.
1416 MethodCounters* mc = method->method_counters();
1417 if (mc == nullptr) {
1418 return false;
1419 }
1420 if (mc->invocation_counter()->carry() || mc->backedge_counter()->carry()) {
1421 return false;
1422 }
1423 if (static_cast<int>(mc->invocation_counter()->count()) <= mtd->invocation_count() &&
1424 static_cast<int>(mc->backedge_counter()->count()) <= mtd->backedge_count()) {
1425 return true;
1426 }
1427 }
1428 return false;
1429 }
1430
1431 template<typename Predicate>
1432 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1433 CompLevel next_level = cur_level;
1434 switch(cur_level) {
1435 default: break;
1436 case CompLevel_none:
1437 next_level = transition_from_none<Predicate>(method, cur_level, disable_feedback);
1438 break;
1439 case CompLevel_limited_profile:
1440 next_level = transition_from_limited_profile<Predicate>(method, cur_level, disable_feedback);
1441 break;
1442 case CompLevel_full_profile:
1443 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1444 break;
1445 }
1446 return next_level;
1447 }
1448
1449 template<typename Predicate>
1450 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1451 precond(cur_level == CompLevel_none);
1452 CompLevel next_level = cur_level;
1453 int i = method->invocation_count();
1454 int b = method->backedge_count();
1455 // If we were at full profile level, would we switch to full opt?
1456 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1457 next_level = CompLevel_full_optimization;
1458 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply(method, cur_level, i, b)) {
1459 // C1-generated fully profiled code is about 30% slower than the limited profile
1460 // code that has only invocation and backedge counters. The observation is that
1461 // if C2 queue is large enough we can spend too much time in the fully profiled code
1462 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1463 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1464 // we choose to compile a limited profiled version and then recompile with full profiling
1465 // when the load on C2 goes down.
1466 if (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization)) {
1467 next_level = CompLevel_limited_profile;
1468 } else {
1469 next_level = CompLevel_full_profile;
1470 }
1471 }
1472 return next_level;
1473 }
1474
1475 template<typename Predicate>
1476 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1477 precond(cur_level == CompLevel_full_profile);
1478 CompLevel next_level = cur_level;
1479 MethodData* mdo = method->method_data();
1480 if (mdo != nullptr) {
1481 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1482 int mdo_i = mdo->invocation_count_delta();
1483 int mdo_b = mdo->backedge_count_delta();
1484 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1485 next_level = CompLevel_full_optimization;
1486 }
1487 } else {
1488 next_level = CompLevel_full_optimization;
1489 }
1490 }
1491 return next_level;
1492 }
1493
1494 template<typename Predicate>
1495 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool disable_feedback) {
1496 precond(cur_level == CompLevel_limited_profile);
1497 CompLevel next_level = cur_level;
1498 int i = method->invocation_count();
1499 int b = method->backedge_count();
1500 MethodData* mdo = method->method_data();
1501 if (mdo != nullptr) {
1502 if (mdo->would_profile()) {
1503 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1504 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1505 Predicate::apply(method, cur_level, i, b))) {
1506 next_level = CompLevel_full_profile;
1507 }
1508 } else {
1509 next_level = CompLevel_full_optimization;
1510 }
1511 } else {
1512 // If there is no MDO we need to profile
1513 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1514 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1515 Predicate::apply(method, cur_level, i, b))) {
1516 next_level = CompLevel_full_profile;
1517 }
1518 }
1519 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1520 next_level = CompLevel_full_optimization;
1521 }
1522 return next_level;
1523 }
1524
1525
1526 // Determine if a method should be compiled with a normal entry point at a different level.
1527 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1528 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1529 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1530
1531 // If OSR method level is greater than the regular method level, the levels should be
1532 // equalized by raising the regular method level in order to avoid OSRs during each
1533 // invocation of the method.
1534 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1535 MethodData* mdo = method->method_data();
1536 guarantee(mdo != nullptr, "MDO should not be nullptr");
1537 if (mdo->invocation_count() >= 1) {
1538 next_level = CompLevel_full_optimization;
1539 }
1540 } else {
1541 next_level = MAX2(osr_level, next_level);
1542 }
1543
1544 return next_level;
1545 }
1546
1547 // Determine if we should do an OSR compilation of a given method.
1548 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1549 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1550 if (cur_level == CompLevel_none) {
1551 // If there is a live OSR method that means that we deopted to the interpreter
1552 // for the transition.
1553 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1554 if (osr_level > CompLevel_none) {
1555 return osr_level;
1556 }
1557 }
1558 return next_level;
1559 }
1560
1561 // Handle the invocation event.
1562 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1563 CompLevel level, nmethod* nm, TRAPS) {
1564 if (should_create_mdo(mh, level)) {
1565 create_mdo(mh, THREAD);
1566 }
1567 CompLevel next_level = call_event(mh, level, THREAD);
1568 if (next_level != level) {
1569 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1570 compile(mh, InvocationEntryBci, next_level, THREAD);
1571 }
1572 }
1573 }
1574
1575 // Handle the back branch event. Notice that we can compile the method
1576 // with a regular entry from here.
1577 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1578 int bci, CompLevel level, nmethod* nm, TRAPS) {
1579 if (should_create_mdo(mh, level)) {
1580 create_mdo(mh, THREAD);
1581 }
1582 // Check if MDO should be created for the inlined method
1583 if (should_create_mdo(imh, level)) {
1584 create_mdo(imh, THREAD);
1585 }
1586
1587 if (is_compilation_enabled()) {
1588 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1589 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1590 // At the very least compile the OSR version
1591 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1592 compile(imh, bci, next_osr_level, CHECK);
1593 }
1594
1595 // Use loop event as an opportunity to also check if there's been
1596 // enough calls.
1597 CompLevel cur_level, next_level;
1598 if (mh() != imh()) { // If there is an enclosing method
1599 {
1600 guarantee(nm != nullptr, "Should have nmethod here");
1601 cur_level = comp_level(mh());
1602 next_level = call_event(mh, cur_level, THREAD);
1603
1604 if (max_osr_level == CompLevel_full_optimization) {
1605 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1606 bool make_not_entrant = false;
1607 if (nm->is_osr_method()) {
1608 // This is an osr method, just make it not entrant and recompile later if needed
1609 make_not_entrant = true;
1610 } else {
1611 if (next_level != CompLevel_full_optimization) {
1612 // next_level is not full opt, so we need to recompile the
1613 // enclosing method without the inlinee
1614 cur_level = CompLevel_none;
1615 make_not_entrant = true;
1616 }
1617 }
1618 if (make_not_entrant) {
1619 if (PrintTieredEvents) {
1620 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1621 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1622 }
1623 nm->make_not_entrant(nmethod::InvalidationReason::OSR_INVALIDATION_BACK_BRANCH);
1624 }
1625 }
1626 // Fix up next_level if necessary to avoid deopts
1627 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1628 next_level = CompLevel_full_profile;
1629 }
1630 if (cur_level != next_level) {
1631 if (!CompileBroker::compilation_is_in_queue(mh)) {
1632 compile(mh, InvocationEntryBci, next_level, THREAD);
1633 }
1634 }
1635 }
1636 } else {
1637 cur_level = comp_level(mh());
1638 next_level = call_event(mh, cur_level, THREAD);
1639 if (next_level != cur_level) {
1640 if (!CompileBroker::compilation_is_in_queue(mh)) {
1641 compile(mh, InvocationEntryBci, next_level, THREAD);
1642 }
1643 }
1644 }
1645 }
1646 }
1647