1 /*
2 * Copyright (c) 2000, 2019, 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 "precompiled.hpp"
26 #include "classfile/classLoaderDataGraph.inline.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/scopeDesc.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/methodData.hpp"
33 #include "oops/method.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "prims/nativeLookup.hpp"
36 #include "runtime/compilationPolicy.hpp"
37 #include "runtime/frame.hpp"
38 #include "runtime/handles.inline.hpp"
39 #include "runtime/rframe.hpp"
40 #include "runtime/stubRoutines.hpp"
41 #include "runtime/thread.hpp"
42 #include "runtime/tieredThresholdPolicy.hpp"
43 #include "runtime/timer.hpp"
44 #include "runtime/vframe.hpp"
45 #include "runtime/vmOperations.hpp"
46 #include "utilities/events.hpp"
47 #include "utilities/globalDefinitions.hpp"
48
49 #ifdef COMPILER1
50 #include "c1/c1_Compiler.hpp"
51 #endif
52 #ifdef COMPILER2
53 #include "opto/c2compiler.hpp"
54 #endif
55
56 CompilationPolicy* CompilationPolicy::_policy;
57 elapsedTimer CompilationPolicy::_accumulated_time;
58
59 // Determine compilation policy based on command line argument
60 void compilationPolicy_init() {
61 switch(CompilationPolicyChoice) {
62 case 0:
63 CompilationPolicy::set_policy(new SimpleCompPolicy());
64 break;
65
66 case 1:
67 #ifdef COMPILER2
68 CompilationPolicy::set_policy(new StackWalkCompPolicy());
69 #else
70 Unimplemented();
71 #endif
72 break;
73 case 2:
74 #ifdef TIERED
75 CompilationPolicy::set_policy(new TieredThresholdPolicy());
76 #else
77 Unimplemented();
78 #endif
79 break;
80 default:
81 fatal("CompilationPolicyChoice must be in the range: [0-2]");
82 }
83 CompilationPolicy::policy()->initialize();
84 }
85
86 // Returns true if m must be compiled before executing it
87 // This is intended to force compiles for methods (usually for
88 // debugging) that would otherwise be interpreted for some reason.
89 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
90 // Don't allow Xcomp to cause compiles in replay mode
91 if (ReplayCompiles) return false;
92
93 if (m->has_compiled_code()) return false; // already compiled
94 if (!can_be_compiled(m, comp_level)) return false;
95
96 return !UseInterpreter || // must compile all methods
97 (UseCompiler && AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
98 }
99
100 void CompilationPolicy::compile_if_required(const methodHandle& selected_method, TRAPS) {
101 if (must_be_compiled(selected_method)) {
102 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
103
104 // Note: with several active threads, the must_be_compiled may be true
105 // while can_be_compiled is false; remove assert
106 // assert(CompilationPolicy::can_be_compiled(selected_method), "cannot compile");
107 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
108 // don't force compilation, resolve was on behalf of compiler
109 return;
110 }
111 if (selected_method->method_holder()->is_not_initialized()) {
112 // 'is_not_initialized' means not only '!is_initialized', but also that
113 // initialization has not been started yet ('!being_initialized')
114 // Do not force compilation of methods in uninitialized classes.
115 // Note that doing this would throw an assert later,
116 // in CompileBroker::compile_method.
117 // We sometimes use the link resolver to do reflective lookups
118 // even before classes are initialized.
119 return;
120 }
121 CompileBroker::compile_method(selected_method, InvocationEntryBci,
122 CompilationPolicy::policy()->initial_compile_level(),
123 methodHandle(), 0, CompileTask::Reason_MustBeCompiled, CHECK);
124 }
125 }
126
127 // Returns true if m is allowed to be compiled
128 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
129 // allow any levels for WhiteBox
130 assert(WhiteBoxAPI || comp_level == CompLevel_all || is_compile(comp_level), "illegal compilation level");
131
132 if (m->is_abstract()) return false;
133 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
134
135 // Math intrinsics should never be compiled as this can lead to
136 // monotonicity problems because the interpreter will prefer the
137 // compiled code to the intrinsic version. This can't happen in
138 // production because the invocation counter can't be incremented
139 // but we shouldn't expose the system to this problem in testing
140 // modes.
141 if (!AbstractInterpreter::can_be_compiled(m)) {
142 return false;
143 }
144 if (comp_level == CompLevel_all) {
145 if (TieredCompilation) {
146 // enough to be compilable at any level for tiered
147 return !m->is_not_compilable(CompLevel_simple) || !m->is_not_compilable(CompLevel_full_optimization);
148 } else {
149 // must be compilable at available level for non-tiered
150 return !m->is_not_compilable(CompLevel_highest_tier);
151 }
152 } else if (is_compile(comp_level)) {
153 return !m->is_not_compilable(comp_level);
154 }
155 return false;
156 }
157
158 // Returns true if m is allowed to be osr compiled
159 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
160 bool result = false;
161 if (comp_level == CompLevel_all) {
162 if (TieredCompilation) {
163 // enough to be osr compilable at any level for tiered
164 result = !m->is_not_osr_compilable(CompLevel_simple) || !m->is_not_osr_compilable(CompLevel_full_optimization);
165 } else {
166 // must be osr compilable at available level for non-tiered
167 result = !m->is_not_osr_compilable(CompLevel_highest_tier);
168 }
169 } else if (is_compile(comp_level)) {
170 result = !m->is_not_osr_compilable(comp_level);
171 }
172 return (result && can_be_compiled(m, comp_level));
173 }
174
175 bool CompilationPolicy::is_compilation_enabled() {
176 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
177 return CompileBroker::should_compile_new_jobs();
178 }
179
180 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
181 #if INCLUDE_JVMCI
182 if (UseJVMCICompiler && !BackgroundCompilation) {
183 /*
184 * In blocking compilation mode, the CompileBroker will make
185 * compilations submitted by a JVMCI compiler thread non-blocking. These
186 * compilations should be scheduled after all blocking compilations
187 * to service non-compiler related compilations sooner and reduce the
188 * chance of such compilations timing out.
189 */
190 for (CompileTask* task = compile_queue->first(); task != NULL; task = task->next()) {
191 if (task->is_blocking()) {
192 return task;
193 }
194 }
195 }
196 #endif
197 return compile_queue->first();
198 }
199
200 #ifndef PRODUCT
201 void CompilationPolicy::print_time() {
202 tty->print_cr ("Accumulated compilationPolicy times:");
203 tty->print_cr ("---------------------------");
204 tty->print_cr (" Total: %3.3f sec.", _accumulated_time.seconds());
205 }
206
207 void NonTieredCompPolicy::trace_osr_completion(nmethod* osr_nm) {
208 if (TraceOnStackReplacement) {
209 if (osr_nm == NULL) tty->print_cr("compilation failed");
210 else tty->print_cr("nmethod " INTPTR_FORMAT, p2i(osr_nm));
211 }
212 }
213 #endif // !PRODUCT
214
215 void NonTieredCompPolicy::initialize() {
216 // Setup the compiler thread numbers
217 if (CICompilerCountPerCPU) {
218 // Example: if CICompilerCountPerCPU is true, then we get
219 // max(log2(8)-1,1) = 2 compiler threads on an 8-way machine.
220 // May help big-app startup time.
221 _compiler_count = MAX2(log2_int(os::active_processor_count())-1,1);
222 // Make sure there is enough space in the code cache to hold all the compiler buffers
223 size_t buffer_size = 1;
224 #ifdef COMPILER1
225 buffer_size = is_client_compilation_mode_vm() ? Compiler::code_buffer_size() : buffer_size;
226 #endif
227 #ifdef COMPILER2
228 buffer_size = is_server_compilation_mode_vm() ? C2Compiler::initial_code_buffer_size() : buffer_size;
229 #endif
230 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
231 if (_compiler_count > max_count) {
232 // Lower the compiler count such that all buffers fit into the code cache
233 _compiler_count = MAX2(max_count, 1);
234 }
235 FLAG_SET_ERGO(intx, CICompilerCount, _compiler_count);
236 } else {
237 _compiler_count = CICompilerCount;
238 }
239 }
240
241 // Note: this policy is used ONLY if TieredCompilation is off.
242 // compiler_count() behaves the following way:
243 // - with TIERED build (with both COMPILER1 and COMPILER2 defined) it should return
244 // zero for the c1 compilation levels in server compilation mode runs
245 // and c2 compilation levels in client compilation mode runs.
246 // - with COMPILER2 not defined it should return zero for c2 compilation levels.
247 // - with COMPILER1 not defined it should return zero for c1 compilation levels.
248 // - if neither is defined - always return zero.
249 int NonTieredCompPolicy::compiler_count(CompLevel comp_level) {
250 assert(!TieredCompilation, "This policy should not be used with TieredCompilation");
251 if (COMPILER2_PRESENT(is_server_compilation_mode_vm() && is_c2_compile(comp_level) ||)
252 is_client_compilation_mode_vm() && is_c1_compile(comp_level)) {
253 return _compiler_count;
254 }
255 return 0;
256 }
257
258 void NonTieredCompPolicy::reset_counter_for_invocation_event(const methodHandle& m) {
259 // Make sure invocation and backedge counter doesn't overflow again right away
260 // as would be the case for native methods.
261
262 // BUT also make sure the method doesn't look like it was never executed.
263 // Set carry bit and reduce counter's value to min(count, CompileThreshold/2).
264 MethodCounters* mcs = m->method_counters();
265 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling");
266 mcs->invocation_counter()->set_carry();
267 mcs->backedge_counter()->set_carry();
268
269 assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed");
270 }
271
272 void NonTieredCompPolicy::reset_counter_for_back_branch_event(const methodHandle& m) {
273 // Delay next back-branch event but pump up invocation counter to trigger
274 // whole method compilation.
275 MethodCounters* mcs = m->method_counters();
276 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling");
277 InvocationCounter* i = mcs->invocation_counter();
278 InvocationCounter* b = mcs->backedge_counter();
279
280 // Don't set invocation_counter's value too low otherwise the method will
281 // look like immature (ic < ~5300) which prevents the inlining based on
282 // the type profiling.
283 i->set(i->state(), CompileThreshold);
284 // Don't reset counter too low - it is used to check if OSR method is ready.
285 b->set(b->state(), CompileThreshold / 2);
286 }
287
288 //
289 // CounterDecay
290 //
291 // Iterates through invocation counters and decrements them. This
292 // is done at each safepoint.
293 //
294 class CounterDecay : public AllStatic {
295 static jlong _last_timestamp;
296 static void do_method(Method* m) {
297 MethodCounters* mcs = m->method_counters();
298 if (mcs != NULL) {
299 mcs->invocation_counter()->decay();
300 }
301 }
302 public:
303 static void decay();
304 static bool is_decay_needed() {
305 return (os::javaTimeMillis() - _last_timestamp) > CounterDecayMinIntervalLength;
306 }
307 };
308
309 jlong CounterDecay::_last_timestamp = 0;
310
311 void CounterDecay::decay() {
312 _last_timestamp = os::javaTimeMillis();
313
314 // This operation is going to be performed only at the end of a safepoint
315 // and hence GC's will not be going on, all Java mutators are suspended
316 // at this point and hence SystemDictionary_lock is also not needed.
317 assert(SafepointSynchronize::is_at_safepoint(), "can only be executed at a safepoint");
318 size_t nclasses = ClassLoaderDataGraph::num_instance_classes();
319 size_t classes_per_tick = nclasses * (CounterDecayMinIntervalLength * 1e-3 /
320 CounterHalfLifeTime);
321 for (size_t i = 0; i < classes_per_tick; i++) {
322 InstanceKlass* k = ClassLoaderDataGraph::try_get_next_class();
323 if (k != NULL) {
324 k->methods_do(do_method);
325 }
326 }
327 }
328
329 // Called at the end of the safepoint
330 void NonTieredCompPolicy::do_safepoint_work() {
331 if(UseCounterDecay && CounterDecay::is_decay_needed()) {
332 CounterDecay::decay();
333 }
334 }
335
336 void NonTieredCompPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
337 ScopeDesc* sd = trap_scope;
338 MethodCounters* mcs;
339 InvocationCounter* c;
340 for (; !sd->is_top(); sd = sd->sender()) {
341 mcs = sd->method()->method_counters();
342 if (mcs != NULL) {
343 // Reset ICs of inlined methods, since they can trigger compilations also.
344 mcs->invocation_counter()->reset();
345 }
346 }
347 mcs = sd->method()->method_counters();
348 if (mcs != NULL) {
349 c = mcs->invocation_counter();
350 if (is_osr) {
351 // It was an OSR method, so bump the count higher.
352 c->set(c->state(), CompileThreshold);
353 } else {
354 c->reset();
355 }
356 mcs->backedge_counter()->reset();
357 }
358 }
359
360 // This method can be called by any component of the runtime to notify the policy
361 // that it's recommended to delay the compilation of this method.
362 void NonTieredCompPolicy::delay_compilation(Method* method) {
363 MethodCounters* mcs = method->method_counters();
364 if (mcs != NULL) {
365 mcs->invocation_counter()->decay();
366 mcs->backedge_counter()->decay();
367 }
368 }
369
370 void NonTieredCompPolicy::disable_compilation(Method* method) {
371 MethodCounters* mcs = method->method_counters();
372 if (mcs != NULL) {
373 mcs->invocation_counter()->set_state(InvocationCounter::wait_for_nothing);
374 mcs->backedge_counter()->set_state(InvocationCounter::wait_for_nothing);
375 }
376 }
377
378 CompileTask* NonTieredCompPolicy::select_task(CompileQueue* compile_queue) {
379 return select_task_helper(compile_queue);
380 }
381
382 bool NonTieredCompPolicy::is_mature(Method* method) {
383 MethodData* mdo = method->method_data();
384 assert(mdo != NULL, "Should be");
385 uint current = mdo->mileage_of(method);
386 uint initial = mdo->creation_mileage();
387 if (current < initial)
388 return true; // some sort of overflow
389 uint target;
390 if (ProfileMaturityPercentage <= 0)
391 target = (uint) -ProfileMaturityPercentage; // absolute value
392 else
393 target = (uint)( (ProfileMaturityPercentage * CompileThreshold) / 100 );
394 return (current >= initial + target);
395 }
396
397 nmethod* NonTieredCompPolicy::event(const methodHandle& method, const methodHandle& inlinee, int branch_bci,
398 int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread) {
399 assert(comp_level == CompLevel_none, "This should be only called from the interpreter");
400 NOT_PRODUCT(trace_frequency_counter_overflow(method, branch_bci, bci));
401 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) {
402 // If certain JVMTI events (e.g. frame pop event) are requested then the
403 // thread is forced to remain in interpreted code. This is
404 // implemented partly by a check in the run_compiled_code
405 // section of the interpreter whether we should skip running
406 // compiled code, and partly by skipping OSR compiles for
407 // interpreted-only threads.
408 if (bci != InvocationEntryBci) {
409 reset_counter_for_back_branch_event(method);
410 return NULL;
411 }
412 }
413 if (ReplayCompiles) {
414 // Don't trigger other compiles in testing mode
415 if (bci == InvocationEntryBci) {
416 reset_counter_for_invocation_event(method);
417 } else {
418 reset_counter_for_back_branch_event(method);
419 }
420 return NULL;
421 }
422
423 if (bci == InvocationEntryBci) {
424 // when code cache is full, compilation gets switched off, UseCompiler
425 // is set to false
426 if (!method->has_compiled_code() && UseCompiler) {
427 method_invocation_event(method, thread);
428 } else {
429 // Force counter overflow on method entry, even if no compilation
430 // happened. (The method_invocation_event call does this also.)
431 reset_counter_for_invocation_event(method);
432 }
433 // compilation at an invocation overflow no longer goes and retries test for
434 // compiled method. We always run the loser of the race as interpreted.
435 // so return NULL
436 return NULL;
437 } else {
438 // counter overflow in a loop => try to do on-stack-replacement
439 nmethod* osr_nm = method->lookup_osr_nmethod_for(bci, CompLevel_highest_tier, true);
440 NOT_PRODUCT(trace_osr_request(method, osr_nm, bci));
441 // when code cache is full, we should not compile any more...
442 if (osr_nm == NULL && UseCompiler) {
443 method_back_branch_event(method, bci, thread);
444 osr_nm = method->lookup_osr_nmethod_for(bci, CompLevel_highest_tier, true);
445 }
446 if (osr_nm == NULL) {
447 reset_counter_for_back_branch_event(method);
448 return NULL;
449 }
450 return osr_nm;
451 }
452 return NULL;
453 }
454
455 #ifndef PRODUCT
456 void NonTieredCompPolicy::trace_frequency_counter_overflow(const methodHandle& m, int branch_bci, int bci) {
457 if (TraceInvocationCounterOverflow) {
458 MethodCounters* mcs = m->method_counters();
459 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling");
460 InvocationCounter* ic = mcs->invocation_counter();
461 InvocationCounter* bc = mcs->backedge_counter();
462 ResourceMark rm;
463 if (bci == InvocationEntryBci) {
464 tty->print("comp-policy cntr ovfl @ %d in entry of ", bci);
465 } else {
466 tty->print("comp-policy cntr ovfl @ %d in loop of ", bci);
467 }
468 m->print_value();
469 tty->cr();
470 ic->print();
471 bc->print();
472 if (ProfileInterpreter) {
473 if (bci != InvocationEntryBci) {
474 MethodData* mdo = m->method_data();
475 if (mdo != NULL) {
476 ProfileData *pd = mdo->bci_to_data(branch_bci);
477 if (pd == NULL) {
478 tty->print_cr("back branch count = N/A (missing ProfileData)");
479 } else {
480 tty->print_cr("back branch count = %d", pd->as_JumpData()->taken());
481 }
482 }
483 }
484 }
485 }
486 }
487
488 void NonTieredCompPolicy::trace_osr_request(const methodHandle& method, nmethod* osr, int bci) {
489 if (TraceOnStackReplacement) {
490 ResourceMark rm;
491 tty->print(osr != NULL ? "Reused OSR entry for " : "Requesting OSR entry for ");
492 method->print_short_name(tty);
493 tty->print_cr(" at bci %d", bci);
494 }
495 }
496 #endif // !PRODUCT
497
498 // SimpleCompPolicy - compile current method
499
500 void SimpleCompPolicy::method_invocation_event(const methodHandle& m, JavaThread* thread) {
501 const int comp_level = CompLevel_highest_tier;
502 const int hot_count = m->invocation_count();
503 reset_counter_for_invocation_event(m);
504
505 if (is_compilation_enabled() && can_be_compiled(m, comp_level)) {
506 CompiledMethod* nm = m->code();
507 if (nm == NULL ) {
508 CompileBroker::compile_method(m, InvocationEntryBci, comp_level, m, hot_count, CompileTask::Reason_InvocationCount, thread);
509 }
510 }
511 }
512
513 void SimpleCompPolicy::method_back_branch_event(const methodHandle& m, int bci, JavaThread* thread) {
514 const int comp_level = CompLevel_highest_tier;
515 const int hot_count = m->backedge_count();
516
517 if (is_compilation_enabled() && can_be_osr_compiled(m, comp_level)) {
518 CompileBroker::compile_method(m, bci, comp_level, m, hot_count, CompileTask::Reason_BackedgeCount, thread);
519 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(bci, comp_level, true));)
520 }
521 }
522 // StackWalkCompPolicy - walk up stack to find a suitable method to compile
523
524 #ifdef COMPILER2
525 const char* StackWalkCompPolicy::_msg = NULL;
526
527
528 // Consider m for compilation
529 void StackWalkCompPolicy::method_invocation_event(const methodHandle& m, JavaThread* thread) {
530 const int comp_level = CompLevel_highest_tier;
531 const int hot_count = m->invocation_count();
532 reset_counter_for_invocation_event(m);
533
534 if (is_compilation_enabled() && m->code() == NULL && can_be_compiled(m, comp_level)) {
535 ResourceMark rm(thread);
536 frame fr = thread->last_frame();
537 assert(fr.is_interpreted_frame(), "must be interpreted");
538 assert(fr.interpreter_frame_method() == m(), "bad method");
539
540 if (TraceCompilationPolicy) {
541 tty->print("method invocation trigger: ");
542 m->print_short_name(tty);
543 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", p2i((address)m()), m->code_size());
544 }
545 RegisterMap reg_map(thread, false);
546 javaVFrame* triggerVF = thread->last_java_vframe(®_map);
547 // triggerVF is the frame that triggered its counter
548 RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m());
549
550 if (first->top_method()->code() != NULL) {
551 // called obsolete method/nmethod -- no need to recompile
552 if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, p2i(first->top_method()->code()));
553 } else {
554 if (TimeCompilationPolicy) accumulated_time()->start();
555 GrowableArray<RFrame*>* stack = new GrowableArray<RFrame*>(50);
556 stack->push(first);
557 RFrame* top = findTopInlinableFrame(stack);
558 if (TimeCompilationPolicy) accumulated_time()->stop();
559 assert(top != NULL, "findTopInlinableFrame returned null");
560 if (TraceCompilationPolicy) top->print();
561 CompileBroker::compile_method(top->top_method(), InvocationEntryBci, comp_level,
562 m, hot_count, CompileTask::Reason_InvocationCount, thread);
563 }
564 }
565 }
566
567 void StackWalkCompPolicy::method_back_branch_event(const methodHandle& m, int bci, JavaThread* thread) {
568 const int comp_level = CompLevel_highest_tier;
569 const int hot_count = m->backedge_count();
570
571 if (is_compilation_enabled() && can_be_osr_compiled(m, comp_level)) {
572 CompileBroker::compile_method(m, bci, comp_level, m, hot_count, CompileTask::Reason_BackedgeCount, thread);
573 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(bci, comp_level, true));)
574 }
575 }
576
577 RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray<RFrame*>* stack) {
578 // go up the stack until finding a frame that (probably) won't be inlined
579 // into its caller
580 RFrame* current = stack->at(0); // current choice for stopping
581 assert( current && !current->is_compiled(), "" );
582 const char* msg = NULL;
583
584 while (1) {
585
586 // before going up the stack further, check if doing so would get us into
587 // compiled code
588 RFrame* next = senderOf(current, stack);
589 if( !next ) // No next frame up the stack?
590 break; // Then compile with current frame
591
592 Method* m = current->top_method();
593 Method* next_m = next->top_method();
594
595 if (TraceCompilationPolicy && Verbose) {
596 tty->print("[caller: ");
597 next_m->print_short_name(tty);
598 tty->print("] ");
599 }
600
601 if( !Inline ) { // Inlining turned off
602 msg = "Inlining turned off";
603 break;
604 }
605 if (next_m->is_not_compilable()) { // Did fail to compile this before/
606 msg = "caller not compilable";
607 break;
608 }
609 if (next->num() > MaxRecompilationSearchLength) {
610 // don't go up too high when searching for recompilees
611 msg = "don't go up any further: > MaxRecompilationSearchLength";
612 break;
613 }
614 if (next->distance() > MaxInterpretedSearchLength) {
615 // don't go up too high when searching for recompilees
616 msg = "don't go up any further: next > MaxInterpretedSearchLength";
617 break;
618 }
619 // Compiled frame above already decided not to inline;
620 // do not recompile him.
621 if (next->is_compiled()) {
622 msg = "not going up into optimized code";
623 break;
624 }
625
626 // Interpreted frame above us was already compiled. Do not force
627 // a recompile, although if the frame above us runs long enough an
628 // OSR might still happen.
629 if( current->is_interpreted() && next_m->has_compiled_code() ) {
630 msg = "not going up -- already compiled caller";
631 break;
632 }
633
634 // Compute how frequent this call site is. We have current method 'm'.
635 // We know next method 'next_m' is interpreted. Find the call site and
636 // check the various invocation counts.
637 int invcnt = 0; // Caller counts
638 if (ProfileInterpreter) {
639 invcnt = next_m->interpreter_invocation_count();
640 }
641 int cnt = 0; // Call site counts
642 if (ProfileInterpreter && next_m->method_data() != NULL) {
643 ResourceMark rm;
644 int bci = next->top_vframe()->bci();
645 ProfileData* data = next_m->method_data()->bci_to_data(bci);
646 if (data != NULL && data->is_CounterData())
647 cnt = data->as_CounterData()->count();
648 }
649
650 // Caller counts / call-site counts; i.e. is this call site
651 // a hot call site for method next_m?
652 int freq = (invcnt) ? cnt/invcnt : cnt;
653
654 // Check size and frequency limits
655 if ((msg = shouldInline(m, freq, cnt)) != NULL) {
656 break;
657 }
658 // Check inlining negative tests
659 if ((msg = shouldNotInline(m)) != NULL) {
660 break;
661 }
662
663
664 // If the caller method is too big or something then we do not want to
665 // compile it just to inline a method
666 if (!can_be_compiled(next_m, CompLevel_any)) {
667 msg = "caller cannot be compiled";
668 break;
669 }
670
671 if( next_m->name() == vmSymbols::class_initializer_name() ) {
672 msg = "do not compile class initializer (OSR ok)";
673 break;
674 }
675
676 if (TraceCompilationPolicy && Verbose) {
677 tty->print("\n\t check caller: ");
678 next_m->print_short_name(tty);
679 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", p2i((address)next_m), next_m->code_size());
680 }
681
682 current = next;
683 }
684
685 assert( !current || !current->is_compiled(), "" );
686
687 if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg);
688
689 return current;
690 }
691
692 RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray<RFrame*>* stack) {
693 RFrame* sender = rf->caller();
694 if (sender && sender->num() == stack->length()) stack->push(sender);
695 return sender;
696 }
697
698
699 const char* StackWalkCompPolicy::shouldInline(const methodHandle& m, float freq, int cnt) {
700 // Allows targeted inlining
701 // positive filter: should send be inlined? returns NULL (--> yes)
702 // or rejection msg
703 int max_size = MaxInlineSize;
704 int cost = m->code_size();
705
706 // Check for too many throws (and not too huge)
707 if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) {
708 return NULL;
709 }
710
711 // bump the max size if the call is frequent
712 if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) {
713 if (TraceFrequencyInlining) {
714 tty->print("(Inlined frequent method)\n");
715 m->print();
716 }
717 max_size = FreqInlineSize;
718 }
719 if (cost > max_size) {
720 return (_msg = "too big");
721 }
722 return NULL;
723 }
724
725
726 const char* StackWalkCompPolicy::shouldNotInline(const methodHandle& m) {
727 // negative filter: should send NOT be inlined? returns NULL (--> inline) or rejection msg
728 if (m->is_abstract()) return (_msg = "abstract method");
729 // note: we allow ik->is_abstract()
730 if (!m->method_holder()->is_initialized()) return (_msg = "method holder not initialized");
731 if (m->is_native()) return (_msg = "native method");
732 CompiledMethod* m_code = m->code();
733 if (m_code != NULL && m_code->code_size() > InlineSmallCode)
734 return (_msg = "already compiled into a big method");
735
736 // use frequency-based objections only for non-trivial methods
737 if (m->code_size() <= MaxTrivialSize) return NULL;
738 if (UseInterpreter) { // don't use counts with -Xcomp
739 if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed");
740 if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times");
741 }
742 if (Method::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes");
743
744 return NULL;
745 }
746
747
748
749 #endif // COMPILER2