1 /* 2 * Copyright 2000-2007 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. 22 * 23 */ 24 25 # include "incls/_precompiled.incl" 26 # include "incls/_compilationPolicy.cpp.incl" 27 28 CompilationPolicy* CompilationPolicy::_policy; 29 elapsedTimer CompilationPolicy::_accumulated_time; 30 bool CompilationPolicy::_in_vm_startup; 31 32 // Determine compilation policy based on command line argument 33 void compilationPolicy_init() { 34 CompilationPolicy::set_in_vm_startup(DelayCompilationDuringStartup); 35 36 switch(CompilationPolicyChoice) { 37 case 0: 38 CompilationPolicy::set_policy(new SimpleCompPolicy()); 39 break; 40 41 case 1: 42 #ifdef COMPILER2 43 CompilationPolicy::set_policy(new StackWalkCompPolicy()); 44 #else 45 Unimplemented(); 46 #endif 47 break; 48 49 default: 50 fatal("CompilationPolicyChoice must be in the range: [0-1]"); 51 } 52 } 53 54 void CompilationPolicy::completed_vm_startup() { 55 if (TraceCompilationPolicy) { 56 tty->print("CompilationPolicy: completed vm startup.\n"); 57 } 58 _in_vm_startup = false; 59 } 60 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; 67 68 return !UseInterpreter || // must compile all methods 69 (UseCompiler && AlwaysCompileLoopMethods && m->has_loops()); // eagerly compile loop methods 70 } 71 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; 76 77 return !m->is_not_compilable(); 78 } 79 80 #ifndef PRODUCT 81 void CompilationPolicy::print_time() { 82 tty->print_cr ("Accumulated compilationPolicy times:"); 83 tty->print_cr ("---------------------------"); 84 tty->print_cr (" Total: %3.3f sec.", _accumulated_time.seconds()); 85 } 86 87 static void trace_osr_completion(nmethod* osr_nm) { 88 if (TraceOnStackReplacement) { 89 if (osr_nm == NULL) tty->print_cr("compilation failed"); 90 else tty->print_cr("nmethod " INTPTR_FORMAT, osr_nm); 91 } 92 } 93 #endif // !PRODUCT 94 95 void CompilationPolicy::reset_counter_for_invocation_event(methodHandle m) { 96 // Make sure invocation and backedge counter doesn't overflow again right away 97 // as would be the case for native methods. 98 99 // BUT also make sure the method doesn't look like it was never executed. 100 // Set carry bit and reduce counter's value to min(count, CompileThreshold/2). 101 m->invocation_counter()->set_carry(); 102 m->backedge_counter()->set_carry(); 103 104 assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed"); 105 } 106 107 void CompilationPolicy::reset_counter_for_back_branch_event(methodHandle m) { 108 // Delay next back-branch event but pump up invocation counter to triger 109 // whole method compilation. 110 InvocationCounter* i = m->invocation_counter(); 111 InvocationCounter* b = m->backedge_counter(); 112 113 // Don't set invocation_counter's value too low otherwise the method will 114 // look like immature (ic < ~5300) which prevents the inlining based on 115 // the type profiling. 116 i->set(i->state(), CompileThreshold); 117 // Don't reset counter too low - it is used to check if OSR method is ready. 118 b->set(b->state(), CompileThreshold / 2); 119 } 120 121 // SimpleCompPolicy - compile current method 122 123 void SimpleCompPolicy::method_invocation_event( methodHandle m, TRAPS) { 124 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); 125 126 int hot_count = m->invocation_count(); 127 reset_counter_for_invocation_event(m); 128 const char* comment = "count"; 129 130 if (!delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler) { 131 nmethod* nm = m->code(); 132 if (nm == NULL ) { 133 const char* comment = "count"; 134 CompileBroker::compile_method(m, InvocationEntryBci, 135 m, hot_count, comment, CHECK); 136 } else { 137 #ifdef TIERED 138 139 if (nm->is_compiled_by_c1()) { 140 const char* comment = "tier1 overflow"; 141 CompileBroker::compile_method(m, InvocationEntryBci, 142 m, hot_count, comment, CHECK); 143 } 144 #endif // TIERED 145 } 146 } 147 } 148 149 void SimpleCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) { 150 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); 151 152 int hot_count = m->backedge_count(); 153 const char* comment = "backedge_count"; 154 155 if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m)) { 156 CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK); 157 158 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));) 159 } 160 } 161 162 int SimpleCompPolicy::compilation_level(methodHandle m, int branch_bci) 163 { 164 #ifdef TIERED 165 if (!TieredCompilation) { 166 return CompLevel_highest_tier; 167 } 168 if (/* m()->tier1_compile_done() && */ 169 // QQQ HACK FIX ME set tier1_compile_done!! 170 !m()->is_native()) { 171 // Grab the nmethod so it doesn't go away while it's being queried 172 nmethod* code = m()->code(); 173 if (code != NULL && code->is_compiled_by_c1()) { 174 return CompLevel_highest_tier; 175 } 176 } 177 return CompLevel_fast_compile; 178 #else 179 return CompLevel_highest_tier; 180 #endif // TIERED 181 } 182 183 // StackWalkCompPolicy - walk up stack to find a suitable method to compile 184 185 #ifdef COMPILER2 186 const char* StackWalkCompPolicy::_msg = NULL; 187 188 189 // Consider m for compilation 190 void StackWalkCompPolicy::method_invocation_event(methodHandle m, TRAPS) { 191 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); 192 193 int hot_count = m->invocation_count(); 194 reset_counter_for_invocation_event(m); 195 const char* comment = "count"; 196 197 if (m->code() == NULL && !delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler) { 198 ResourceMark rm(THREAD); 199 JavaThread *thread = (JavaThread*)THREAD; 200 frame fr = thread->last_frame(); 201 assert(fr.is_interpreted_frame(), "must be interpreted"); 202 assert(fr.interpreter_frame_method() == m(), "bad method"); 203 204 if (TraceCompilationPolicy) { 205 tty->print("method invocation trigger: "); 206 m->print_short_name(tty); 207 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)m(), m->code_size()); 208 } 209 RegisterMap reg_map(thread, false); 210 javaVFrame* triggerVF = thread->last_java_vframe(®_map); 211 // triggerVF is the frame that triggered its counter 212 RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m); 213 214 if (first->top_method()->code() != NULL) { 215 // called obsolete method/nmethod -- no need to recompile 216 if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, first->top_method()->code()); 217 } else if (compilation_level(m, InvocationEntryBci) == CompLevel_fast_compile) { 218 // Tier1 compilation policy avaoids stack walking. 219 CompileBroker::compile_method(m, InvocationEntryBci, 220 m, hot_count, comment, CHECK); 221 } else { 222 if (TimeCompilationPolicy) accumulated_time()->start(); 223 GrowableArray<RFrame*>* stack = new GrowableArray<RFrame*>(50); 224 stack->push(first); 225 RFrame* top = findTopInlinableFrame(stack); 226 if (TimeCompilationPolicy) accumulated_time()->stop(); 227 assert(top != NULL, "findTopInlinableFrame returned null"); 228 if (TraceCompilationPolicy) top->print(); 229 CompileBroker::compile_method(top->top_method(), InvocationEntryBci, 230 m, hot_count, comment, CHECK); 231 } 232 } 233 } 234 235 void StackWalkCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) { 236 assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); 237 238 int hot_count = m->backedge_count(); 239 const char* comment = "backedge_count"; 240 241 if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m)) { 242 CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK); 243 244 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));) 245 } 246 } 247 248 int StackWalkCompPolicy::compilation_level(methodHandle m, int osr_bci) 249 { 250 int comp_level = CompLevel_full_optimization; 251 if (TieredCompilation && osr_bci == InvocationEntryBci) { 252 if (CompileTheWorld) { 253 // Under CTW, the first compile is tier1, the second tier2 254 if (m->highest_tier_compile() == CompLevel_none) { 255 comp_level = CompLevel_fast_compile; 256 } 257 } else if (!m->has_osr_nmethod()) { 258 // Before tier1 is done, use invocation_count + backedge_count to 259 // compare against the threshold. After that, the counters may/will 260 // be reset, so rely on the straight interpreter_invocation_count. 261 if (m->highest_tier_compile() == CompLevel_initial_compile) { 262 if (m->interpreter_invocation_count() < Tier2CompileThreshold) { 263 comp_level = CompLevel_fast_compile; 264 } 265 } else if (m->invocation_count() + m->backedge_count() < 266 Tier2CompileThreshold) { 267 comp_level = CompLevel_fast_compile; 268 } 269 } 270 271 } 272 return comp_level; 273 } 274 275 276 RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray<RFrame*>* stack) { 277 // go up the stack until finding a frame that (probably) won't be inlined 278 // into its caller 279 RFrame* current = stack->at(0); // current choice for stopping 280 assert( current && !current->is_compiled(), "" ); 281 const char* msg = NULL; 282 283 while (1) { 284 285 // before going up the stack further, check if doing so would get us into 286 // compiled code 287 RFrame* next = senderOf(current, stack); 288 if( !next ) // No next frame up the stack? 289 break; // Then compile with current frame 290 291 methodHandle m = current->top_method(); 292 methodHandle next_m = next->top_method(); 293 294 if (TraceCompilationPolicy && Verbose) { 295 tty->print("[caller: "); 296 next_m->print_short_name(tty); 297 tty->print("] "); 298 } 299 300 if( !Inline ) { // Inlining turned off 301 msg = "Inlining turned off"; 302 break; 303 } 304 if (next_m->is_not_compilable()) { // Did fail to compile this before/ 305 msg = "caller not compilable"; 306 break; 307 } 308 if (next->num() > MaxRecompilationSearchLength) { 309 // don't go up too high when searching for recompilees 310 msg = "don't go up any further: > MaxRecompilationSearchLength"; 311 break; 312 } 313 if (next->distance() > MaxInterpretedSearchLength) { 314 // don't go up too high when searching for recompilees 315 msg = "don't go up any further: next > MaxInterpretedSearchLength"; 316 break; 317 } 318 // Compiled frame above already decided not to inline; 319 // do not recompile him. 320 if (next->is_compiled()) { 321 msg = "not going up into optimized code"; 322 break; 323 } 324 325 // Interpreted frame above us was already compiled. Do not force 326 // a recompile, although if the frame above us runs long enough an 327 // OSR might still happen. 328 if( current->is_interpreted() && next_m->has_compiled_code() ) { 329 msg = "not going up -- already compiled caller"; 330 break; 331 } 332 333 // Compute how frequent this call site is. We have current method 'm'. 334 // We know next method 'next_m' is interpreted. Find the call site and 335 // check the various invocation counts. 336 int invcnt = 0; // Caller counts 337 if (ProfileInterpreter) { 338 invcnt = next_m->interpreter_invocation_count(); 339 } 340 int cnt = 0; // Call site counts 341 if (ProfileInterpreter && next_m->method_data() != NULL) { 342 ResourceMark rm; 343 int bci = next->top_vframe()->bci(); 344 ProfileData* data = next_m->method_data()->bci_to_data(bci); 345 if (data != NULL && data->is_CounterData()) 346 cnt = data->as_CounterData()->count(); 347 } 348 349 // Caller counts / call-site counts; i.e. is this call site 350 // a hot call site for method next_m? 351 int freq = (invcnt) ? cnt/invcnt : cnt; 352 353 // Check size and frequency limits 354 if ((msg = shouldInline(m, freq, cnt)) != NULL) { 355 break; 356 } 357 // Check inlining negative tests 358 if ((msg = shouldNotInline(m)) != NULL) { 359 break; 360 } 361 362 363 // If the caller method is too big or something then we do not want to 364 // compile it just to inline a method 365 if (!canBeCompiled(next_m)) { 366 msg = "caller cannot be compiled"; 367 break; 368 } 369 370 if( next_m->name() == vmSymbols::class_initializer_name() ) { 371 msg = "do not compile class initializer (OSR ok)"; 372 break; 373 } 374 375 if (TraceCompilationPolicy && Verbose) { 376 tty->print("\n\t check caller: "); 377 next_m->print_short_name(tty); 378 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)next_m(), next_m->code_size()); 379 } 380 381 current = next; 382 } 383 384 assert( !current || !current->is_compiled(), "" ); 385 386 if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg); 387 388 return current; 389 } 390 391 RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray<RFrame*>* stack) { 392 RFrame* sender = rf->caller(); 393 if (sender && sender->num() == stack->length()) stack->push(sender); 394 return sender; 395 } 396 397 398 const char* StackWalkCompPolicy::shouldInline(methodHandle m, float freq, int cnt) { 399 // Allows targeted inlining 400 // positive filter: should send be inlined? returns NULL (--> yes) 401 // or rejection msg 402 int max_size = MaxInlineSize; 403 int cost = m->code_size(); 404 405 // Check for too many throws (and not too huge) 406 if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) { 407 return NULL; 408 } 409 410 // bump the max size if the call is frequent 411 if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) { 412 if (TraceFrequencyInlining) { 413 tty->print("(Inlined frequent method)\n"); 414 m->print(); 415 } 416 max_size = FreqInlineSize; 417 } 418 if (cost > max_size) { 419 return (_msg = "too big"); 420 } 421 return NULL; 422 } 423 424 425 const char* StackWalkCompPolicy::shouldNotInline(methodHandle m) { 426 // negative filter: should send NOT be inlined? returns NULL (--> inline) or rejection msg 427 if (m->is_abstract()) return (_msg = "abstract method"); 428 // note: we allow ik->is_abstract() 429 if (!instanceKlass::cast(m->method_holder())->is_initialized()) return (_msg = "method holder not initialized"); 430 if (m->is_native()) return (_msg = "native method"); 431 nmethod* m_code = m->code(); 432 if( m_code != NULL && m_code->instructions_size() > InlineSmallCode ) 433 return (_msg = "already compiled into a big method"); 434 435 // use frequency-based objections only for non-trivial methods 436 if (m->code_size() <= MaxTrivialSize) return NULL; 437 if (UseInterpreter) { // don't use counts with -Xcomp 438 if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed"); 439 if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times"); 440 } 441 if (methodOopDesc::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes"); 442 443 return NULL; 444 } 445 446 447 448 #endif // COMPILER2