Mon, 25 Jan 2010 18:03:29 -0500
6919980: G1: remove +UseG1GC from under experimental options (second attempt)
Summary: Trying this again, as the original change was lost.
Reviewed-by: ysr, jmasa
1 /*
2 * Copyright 2000-2010 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
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23 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_compilationPolicy.cpp.incl"
28 CompilationPolicy* CompilationPolicy::_policy;
29 elapsedTimer CompilationPolicy::_accumulated_time;
30 bool CompilationPolicy::_in_vm_startup;
32 // Determine compilation policy based on command line argument
33 void compilationPolicy_init() {
34 CompilationPolicy::set_in_vm_startup(DelayCompilationDuringStartup);
36 switch(CompilationPolicyChoice) {
37 case 0:
38 CompilationPolicy::set_policy(new SimpleCompPolicy());
39 break;
41 case 1:
42 #ifdef COMPILER2
43 CompilationPolicy::set_policy(new StackWalkCompPolicy());
44 #else
45 Unimplemented();
46 #endif
47 break;
49 default:
50 fatal("CompilationPolicyChoice must be in the range: [0-1]");
51 }
52 }
54 void CompilationPolicy::completed_vm_startup() {
55 if (TraceCompilationPolicy) {
56 tty->print("CompilationPolicy: completed vm startup.\n");
57 }
58 _in_vm_startup = false;
59 }
61 // Returns true if m must be compiled before executing it
62 // This is intended to force compiles for methods (usually for
63 // debugging) that would otherwise be interpreted for some reason.
64 bool CompilationPolicy::mustBeCompiled(methodHandle m) {
65 if (m->has_compiled_code()) return false; // already compiled
66 if (!canBeCompiled(m)) return false;
68 return !UseInterpreter || // must compile all methods
69 (UseCompiler && AlwaysCompileLoopMethods && m->has_loops()); // eagerly compile loop methods
70 }
72 // Returns true if m is allowed to be compiled
73 bool CompilationPolicy::canBeCompiled(methodHandle m) {
74 if (m->is_abstract()) return false;
75 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
77 // Math intrinsics should never be compiled as this can lead to
78 // monotonicity problems because the interpreter will prefer the
79 // compiled code to the intrinsic version. This can't happen in
80 // production because the invocation counter can't be incremented
81 // but we shouldn't expose the system to this problem in testing
82 // modes.
83 if (!AbstractInterpreter::can_be_compiled(m)) {
84 return false;
85 }
87 return !m->is_not_compilable();
88 }
90 #ifndef PRODUCT
91 void CompilationPolicy::print_time() {
92 tty->print_cr ("Accumulated compilationPolicy times:");
93 tty->print_cr ("---------------------------");
94 tty->print_cr (" Total: %3.3f sec.", _accumulated_time.seconds());
95 }
97 static void trace_osr_completion(nmethod* osr_nm) {
98 if (TraceOnStackReplacement) {
99 if (osr_nm == NULL) tty->print_cr("compilation failed");
100 else tty->print_cr("nmethod " INTPTR_FORMAT, osr_nm);
101 }
102 }
103 #endif // !PRODUCT
105 void CompilationPolicy::reset_counter_for_invocation_event(methodHandle m) {
106 // Make sure invocation and backedge counter doesn't overflow again right away
107 // as would be the case for native methods.
109 // BUT also make sure the method doesn't look like it was never executed.
110 // Set carry bit and reduce counter's value to min(count, CompileThreshold/2).
111 m->invocation_counter()->set_carry();
112 m->backedge_counter()->set_carry();
114 assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed");
115 }
117 void CompilationPolicy::reset_counter_for_back_branch_event(methodHandle m) {
118 // Delay next back-branch event but pump up invocation counter to triger
119 // whole method compilation.
120 InvocationCounter* i = m->invocation_counter();
121 InvocationCounter* b = m->backedge_counter();
123 // Don't set invocation_counter's value too low otherwise the method will
124 // look like immature (ic < ~5300) which prevents the inlining based on
125 // the type profiling.
126 i->set(i->state(), CompileThreshold);
127 // Don't reset counter too low - it is used to check if OSR method is ready.
128 b->set(b->state(), CompileThreshold / 2);
129 }
131 // SimpleCompPolicy - compile current method
133 void SimpleCompPolicy::method_invocation_event( methodHandle m, TRAPS) {
134 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
136 int hot_count = m->invocation_count();
137 reset_counter_for_invocation_event(m);
138 const char* comment = "count";
140 if (!delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler) {
141 nmethod* nm = m->code();
142 if (nm == NULL ) {
143 const char* comment = "count";
144 CompileBroker::compile_method(m, InvocationEntryBci,
145 m, hot_count, comment, CHECK);
146 } else {
147 #ifdef TIERED
149 if (nm->is_compiled_by_c1()) {
150 const char* comment = "tier1 overflow";
151 CompileBroker::compile_method(m, InvocationEntryBci,
152 m, hot_count, comment, CHECK);
153 }
154 #endif // TIERED
155 }
156 }
157 }
159 void SimpleCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) {
160 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
162 int hot_count = m->backedge_count();
163 const char* comment = "backedge_count";
165 if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m)) {
166 CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK);
168 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));)
169 }
170 }
172 int SimpleCompPolicy::compilation_level(methodHandle m, int branch_bci)
173 {
174 #ifdef TIERED
175 if (!TieredCompilation) {
176 return CompLevel_highest_tier;
177 }
178 if (/* m()->tier1_compile_done() && */
179 // QQQ HACK FIX ME set tier1_compile_done!!
180 !m()->is_native()) {
181 // Grab the nmethod so it doesn't go away while it's being queried
182 nmethod* code = m()->code();
183 if (code != NULL && code->is_compiled_by_c1()) {
184 return CompLevel_highest_tier;
185 }
186 }
187 return CompLevel_fast_compile;
188 #else
189 return CompLevel_highest_tier;
190 #endif // TIERED
191 }
193 // StackWalkCompPolicy - walk up stack to find a suitable method to compile
195 #ifdef COMPILER2
196 const char* StackWalkCompPolicy::_msg = NULL;
199 // Consider m for compilation
200 void StackWalkCompPolicy::method_invocation_event(methodHandle m, TRAPS) {
201 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
203 int hot_count = m->invocation_count();
204 reset_counter_for_invocation_event(m);
205 const char* comment = "count";
207 if (m->code() == NULL && !delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler) {
208 ResourceMark rm(THREAD);
209 JavaThread *thread = (JavaThread*)THREAD;
210 frame fr = thread->last_frame();
211 assert(fr.is_interpreted_frame(), "must be interpreted");
212 assert(fr.interpreter_frame_method() == m(), "bad method");
214 if (TraceCompilationPolicy) {
215 tty->print("method invocation trigger: ");
216 m->print_short_name(tty);
217 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)m(), m->code_size());
218 }
219 RegisterMap reg_map(thread, false);
220 javaVFrame* triggerVF = thread->last_java_vframe(®_map);
221 // triggerVF is the frame that triggered its counter
222 RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m);
224 if (first->top_method()->code() != NULL) {
225 // called obsolete method/nmethod -- no need to recompile
226 if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, first->top_method()->code());
227 } else if (compilation_level(m, InvocationEntryBci) == CompLevel_fast_compile) {
228 // Tier1 compilation policy avaoids stack walking.
229 CompileBroker::compile_method(m, InvocationEntryBci,
230 m, hot_count, comment, CHECK);
231 } else {
232 if (TimeCompilationPolicy) accumulated_time()->start();
233 GrowableArray<RFrame*>* stack = new GrowableArray<RFrame*>(50);
234 stack->push(first);
235 RFrame* top = findTopInlinableFrame(stack);
236 if (TimeCompilationPolicy) accumulated_time()->stop();
237 assert(top != NULL, "findTopInlinableFrame returned null");
238 if (TraceCompilationPolicy) top->print();
239 CompileBroker::compile_method(top->top_method(), InvocationEntryBci,
240 m, hot_count, comment, CHECK);
241 }
242 }
243 }
245 void StackWalkCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) {
246 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
248 int hot_count = m->backedge_count();
249 const char* comment = "backedge_count";
251 if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m)) {
252 CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK);
254 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));)
255 }
256 }
258 int StackWalkCompPolicy::compilation_level(methodHandle m, int osr_bci)
259 {
260 int comp_level = CompLevel_full_optimization;
261 if (TieredCompilation && osr_bci == InvocationEntryBci) {
262 if (CompileTheWorld) {
263 // Under CTW, the first compile is tier1, the second tier2
264 if (m->highest_tier_compile() == CompLevel_none) {
265 comp_level = CompLevel_fast_compile;
266 }
267 } else if (!m->has_osr_nmethod()) {
268 // Before tier1 is done, use invocation_count + backedge_count to
269 // compare against the threshold. After that, the counters may/will
270 // be reset, so rely on the straight interpreter_invocation_count.
271 if (m->highest_tier_compile() == CompLevel_initial_compile) {
272 if (m->interpreter_invocation_count() < Tier2CompileThreshold) {
273 comp_level = CompLevel_fast_compile;
274 }
275 } else if (m->invocation_count() + m->backedge_count() <
276 Tier2CompileThreshold) {
277 comp_level = CompLevel_fast_compile;
278 }
279 }
281 }
282 return comp_level;
283 }
286 RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray<RFrame*>* stack) {
287 // go up the stack until finding a frame that (probably) won't be inlined
288 // into its caller
289 RFrame* current = stack->at(0); // current choice for stopping
290 assert( current && !current->is_compiled(), "" );
291 const char* msg = NULL;
293 while (1) {
295 // before going up the stack further, check if doing so would get us into
296 // compiled code
297 RFrame* next = senderOf(current, stack);
298 if( !next ) // No next frame up the stack?
299 break; // Then compile with current frame
301 methodHandle m = current->top_method();
302 methodHandle next_m = next->top_method();
304 if (TraceCompilationPolicy && Verbose) {
305 tty->print("[caller: ");
306 next_m->print_short_name(tty);
307 tty->print("] ");
308 }
310 if( !Inline ) { // Inlining turned off
311 msg = "Inlining turned off";
312 break;
313 }
314 if (next_m->is_not_compilable()) { // Did fail to compile this before/
315 msg = "caller not compilable";
316 break;
317 }
318 if (next->num() > MaxRecompilationSearchLength) {
319 // don't go up too high when searching for recompilees
320 msg = "don't go up any further: > MaxRecompilationSearchLength";
321 break;
322 }
323 if (next->distance() > MaxInterpretedSearchLength) {
324 // don't go up too high when searching for recompilees
325 msg = "don't go up any further: next > MaxInterpretedSearchLength";
326 break;
327 }
328 // Compiled frame above already decided not to inline;
329 // do not recompile him.
330 if (next->is_compiled()) {
331 msg = "not going up into optimized code";
332 break;
333 }
335 // Interpreted frame above us was already compiled. Do not force
336 // a recompile, although if the frame above us runs long enough an
337 // OSR might still happen.
338 if( current->is_interpreted() && next_m->has_compiled_code() ) {
339 msg = "not going up -- already compiled caller";
340 break;
341 }
343 // Compute how frequent this call site is. We have current method 'm'.
344 // We know next method 'next_m' is interpreted. Find the call site and
345 // check the various invocation counts.
346 int invcnt = 0; // Caller counts
347 if (ProfileInterpreter) {
348 invcnt = next_m->interpreter_invocation_count();
349 }
350 int cnt = 0; // Call site counts
351 if (ProfileInterpreter && next_m->method_data() != NULL) {
352 ResourceMark rm;
353 int bci = next->top_vframe()->bci();
354 ProfileData* data = next_m->method_data()->bci_to_data(bci);
355 if (data != NULL && data->is_CounterData())
356 cnt = data->as_CounterData()->count();
357 }
359 // Caller counts / call-site counts; i.e. is this call site
360 // a hot call site for method next_m?
361 int freq = (invcnt) ? cnt/invcnt : cnt;
363 // Check size and frequency limits
364 if ((msg = shouldInline(m, freq, cnt)) != NULL) {
365 break;
366 }
367 // Check inlining negative tests
368 if ((msg = shouldNotInline(m)) != NULL) {
369 break;
370 }
373 // If the caller method is too big or something then we do not want to
374 // compile it just to inline a method
375 if (!canBeCompiled(next_m)) {
376 msg = "caller cannot be compiled";
377 break;
378 }
380 if( next_m->name() == vmSymbols::class_initializer_name() ) {
381 msg = "do not compile class initializer (OSR ok)";
382 break;
383 }
385 if (TraceCompilationPolicy && Verbose) {
386 tty->print("\n\t check caller: ");
387 next_m->print_short_name(tty);
388 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)next_m(), next_m->code_size());
389 }
391 current = next;
392 }
394 assert( !current || !current->is_compiled(), "" );
396 if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg);
398 return current;
399 }
401 RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray<RFrame*>* stack) {
402 RFrame* sender = rf->caller();
403 if (sender && sender->num() == stack->length()) stack->push(sender);
404 return sender;
405 }
408 const char* StackWalkCompPolicy::shouldInline(methodHandle m, float freq, int cnt) {
409 // Allows targeted inlining
410 // positive filter: should send be inlined? returns NULL (--> yes)
411 // or rejection msg
412 int max_size = MaxInlineSize;
413 int cost = m->code_size();
415 // Check for too many throws (and not too huge)
416 if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) {
417 return NULL;
418 }
420 // bump the max size if the call is frequent
421 if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) {
422 if (TraceFrequencyInlining) {
423 tty->print("(Inlined frequent method)\n");
424 m->print();
425 }
426 max_size = FreqInlineSize;
427 }
428 if (cost > max_size) {
429 return (_msg = "too big");
430 }
431 return NULL;
432 }
435 const char* StackWalkCompPolicy::shouldNotInline(methodHandle m) {
436 // negative filter: should send NOT be inlined? returns NULL (--> inline) or rejection msg
437 if (m->is_abstract()) return (_msg = "abstract method");
438 // note: we allow ik->is_abstract()
439 if (!instanceKlass::cast(m->method_holder())->is_initialized()) return (_msg = "method holder not initialized");
440 if (m->is_native()) return (_msg = "native method");
441 nmethod* m_code = m->code();
442 if( m_code != NULL && m_code->instructions_size() > InlineSmallCode )
443 return (_msg = "already compiled into a big method");
445 // use frequency-based objections only for non-trivial methods
446 if (m->code_size() <= MaxTrivialSize) return NULL;
447 if (UseInterpreter) { // don't use counts with -Xcomp
448 if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed");
449 if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times");
450 }
451 if (methodOopDesc::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes");
453 return NULL;
454 }
458 #endif // COMPILER2