/* * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ # include "incls/_precompiled.incl" # include "incls/_compilationPolicy.cpp.incl" CompilationPolicy* CompilationPolicy::_policy; elapsedTimer CompilationPolicy::_accumulated_time; bool CompilationPolicy::_in_vm_startup; // Determine compilation policy based on command line argument void compilationPolicy_init() { CompilationPolicy::set_in_vm_startup(DelayCompilationDuringStartup); switch(CompilationPolicyChoice) { case 0: CompilationPolicy::set_policy(new SimpleCompPolicy()); break; case 1: #ifdef COMPILER2 CompilationPolicy::set_policy(new StackWalkCompPolicy()); #else Unimplemented(); #endif break; default: fatal("CompilationPolicyChoice must be in the range: [0-1]"); } } void CompilationPolicy::completed_vm_startup() { if (TraceCompilationPolicy) { tty->print("CompilationPolicy: completed vm startup.\n"); } _in_vm_startup = false; } // Returns true if m must be compiled before executing it // This is intended to force compiles for methods (usually for // debugging) that would otherwise be interpreted for some reason. bool CompilationPolicy::mustBeCompiled(methodHandle m) { if (m->has_compiled_code()) return false; // already compiled if (!canBeCompiled(m)) return false; return !UseInterpreter || // must compile all methods (UseCompiler && AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods } // Returns true if m is allowed to be compiled bool CompilationPolicy::canBeCompiled(methodHandle m) { if (m->is_abstract()) return false; if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false; // Math intrinsics should never be compiled as this can lead to // monotonicity problems because the interpreter will prefer the // compiled code to the intrinsic version. This can't happen in // production because the invocation counter can't be incremented // but we shouldn't expose the system to this problem in testing // modes. if (!AbstractInterpreter::can_be_compiled(m)) { return false; } return !m->is_not_compilable(); } #ifndef PRODUCT void CompilationPolicy::print_time() { tty->print_cr ("Accumulated compilationPolicy times:"); tty->print_cr ("---------------------------"); tty->print_cr (" Total: %3.3f sec.", _accumulated_time.seconds()); } static void trace_osr_completion(nmethod* osr_nm) { if (TraceOnStackReplacement) { if (osr_nm == NULL) tty->print_cr("compilation failed"); else tty->print_cr("nmethod " INTPTR_FORMAT, osr_nm); } } #endif // !PRODUCT void CompilationPolicy::reset_counter_for_invocation_event(methodHandle m) { // Make sure invocation and backedge counter doesn't overflow again right away // as would be the case for native methods. // BUT also make sure the method doesn't look like it was never executed. // Set carry bit and reduce counter's value to min(count, CompileThreshold/2). m->invocation_counter()->set_carry(); m->backedge_counter()->set_carry(); assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed"); } void CompilationPolicy::reset_counter_for_back_branch_event(methodHandle m) { // Delay next back-branch event but pump up invocation counter to triger // whole method compilation. InvocationCounter* i = m->invocation_counter(); InvocationCounter* b = m->backedge_counter(); // Don't set invocation_counter's value too low otherwise the method will // look like immature (ic < ~5300) which prevents the inlining based on // the type profiling. i->set(i->state(), CompileThreshold); // Don't reset counter too low - it is used to check if OSR method is ready. b->set(b->state(), CompileThreshold / 2); } // SimpleCompPolicy - compile current method void SimpleCompPolicy::method_invocation_event( methodHandle m, TRAPS) { assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); int hot_count = m->invocation_count(); reset_counter_for_invocation_event(m); const char* comment = "count"; if (!delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler && CompileBroker::should_compile_new_jobs()) { nmethod* nm = m->code(); if (nm == NULL ) { const char* comment = "count"; CompileBroker::compile_method(m, InvocationEntryBci, m, hot_count, comment, CHECK); } else { #ifdef TIERED if (nm->is_compiled_by_c1()) { const char* comment = "tier1 overflow"; CompileBroker::compile_method(m, InvocationEntryBci, m, hot_count, comment, CHECK); } #endif // TIERED } } } void SimpleCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) { assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); int hot_count = m->backedge_count(); const char* comment = "backedge_count"; if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m) && CompileBroker::should_compile_new_jobs()) { CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK); NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));) } } int SimpleCompPolicy::compilation_level(methodHandle m, int branch_bci) { #ifdef TIERED if (!TieredCompilation) { return CompLevel_highest_tier; } if (/* m()->tier1_compile_done() && */ // QQQ HACK FIX ME set tier1_compile_done!! !m()->is_native()) { // Grab the nmethod so it doesn't go away while it's being queried nmethod* code = m()->code(); if (code != NULL && code->is_compiled_by_c1()) { return CompLevel_highest_tier; } } return CompLevel_fast_compile; #else return CompLevel_highest_tier; #endif // TIERED } // StackWalkCompPolicy - walk up stack to find a suitable method to compile #ifdef COMPILER2 const char* StackWalkCompPolicy::_msg = NULL; // Consider m for compilation void StackWalkCompPolicy::method_invocation_event(methodHandle m, TRAPS) { assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); int hot_count = m->invocation_count(); reset_counter_for_invocation_event(m); const char* comment = "count"; if (m->code() == NULL && !delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler && CompileBroker::should_compile_new_jobs()) { ResourceMark rm(THREAD); JavaThread *thread = (JavaThread*)THREAD; frame fr = thread->last_frame(); assert(fr.is_interpreted_frame(), "must be interpreted"); assert(fr.interpreter_frame_method() == m(), "bad method"); if (TraceCompilationPolicy) { tty->print("method invocation trigger: "); m->print_short_name(tty); tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)m(), m->code_size()); } RegisterMap reg_map(thread, false); javaVFrame* triggerVF = thread->last_java_vframe(®_map); // triggerVF is the frame that triggered its counter RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m); if (first->top_method()->code() != NULL) { // called obsolete method/nmethod -- no need to recompile if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, first->top_method()->code()); } else if (compilation_level(m, InvocationEntryBci) == CompLevel_fast_compile) { // Tier1 compilation policy avaoids stack walking. CompileBroker::compile_method(m, InvocationEntryBci, m, hot_count, comment, CHECK); } else { if (TimeCompilationPolicy) accumulated_time()->start(); GrowableArray* stack = new GrowableArray(50); stack->push(first); RFrame* top = findTopInlinableFrame(stack); if (TimeCompilationPolicy) accumulated_time()->stop(); assert(top != NULL, "findTopInlinableFrame returned null"); if (TraceCompilationPolicy) top->print(); CompileBroker::compile_method(top->top_method(), InvocationEntryBci, m, hot_count, comment, CHECK); } } } void StackWalkCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) { assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now."); int hot_count = m->backedge_count(); const char* comment = "backedge_count"; if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m) && CompileBroker::should_compile_new_jobs()) { CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK); NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));) } } int StackWalkCompPolicy::compilation_level(methodHandle m, int osr_bci) { int comp_level = CompLevel_full_optimization; if (TieredCompilation && osr_bci == InvocationEntryBci) { if (CompileTheWorld) { // Under CTW, the first compile is tier1, the second tier2 if (m->highest_tier_compile() == CompLevel_none) { comp_level = CompLevel_fast_compile; } } else if (!m->has_osr_nmethod()) { // Before tier1 is done, use invocation_count + backedge_count to // compare against the threshold. After that, the counters may/will // be reset, so rely on the straight interpreter_invocation_count. if (m->highest_tier_compile() == CompLevel_initial_compile) { if (m->interpreter_invocation_count() < Tier2CompileThreshold) { comp_level = CompLevel_fast_compile; } } else if (m->invocation_count() + m->backedge_count() < Tier2CompileThreshold) { comp_level = CompLevel_fast_compile; } } } return comp_level; } RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray* stack) { // go up the stack until finding a frame that (probably) won't be inlined // into its caller RFrame* current = stack->at(0); // current choice for stopping assert( current && !current->is_compiled(), "" ); const char* msg = NULL; while (1) { // before going up the stack further, check if doing so would get us into // compiled code RFrame* next = senderOf(current, stack); if( !next ) // No next frame up the stack? break; // Then compile with current frame methodHandle m = current->top_method(); methodHandle next_m = next->top_method(); if (TraceCompilationPolicy && Verbose) { tty->print("[caller: "); next_m->print_short_name(tty); tty->print("] "); } if( !Inline ) { // Inlining turned off msg = "Inlining turned off"; break; } if (next_m->is_not_compilable()) { // Did fail to compile this before/ msg = "caller not compilable"; break; } if (next->num() > MaxRecompilationSearchLength) { // don't go up too high when searching for recompilees msg = "don't go up any further: > MaxRecompilationSearchLength"; break; } if (next->distance() > MaxInterpretedSearchLength) { // don't go up too high when searching for recompilees msg = "don't go up any further: next > MaxInterpretedSearchLength"; break; } // Compiled frame above already decided not to inline; // do not recompile him. if (next->is_compiled()) { msg = "not going up into optimized code"; break; } // Interpreted frame above us was already compiled. Do not force // a recompile, although if the frame above us runs long enough an // OSR might still happen. if( current->is_interpreted() && next_m->has_compiled_code() ) { msg = "not going up -- already compiled caller"; break; } // Compute how frequent this call site is. We have current method 'm'. // We know next method 'next_m' is interpreted. Find the call site and // check the various invocation counts. int invcnt = 0; // Caller counts if (ProfileInterpreter) { invcnt = next_m->interpreter_invocation_count(); } int cnt = 0; // Call site counts if (ProfileInterpreter && next_m->method_data() != NULL) { ResourceMark rm; int bci = next->top_vframe()->bci(); ProfileData* data = next_m->method_data()->bci_to_data(bci); if (data != NULL && data->is_CounterData()) cnt = data->as_CounterData()->count(); } // Caller counts / call-site counts; i.e. is this call site // a hot call site for method next_m? int freq = (invcnt) ? cnt/invcnt : cnt; // Check size and frequency limits if ((msg = shouldInline(m, freq, cnt)) != NULL) { break; } // Check inlining negative tests if ((msg = shouldNotInline(m)) != NULL) { break; } // If the caller method is too big or something then we do not want to // compile it just to inline a method if (!canBeCompiled(next_m)) { msg = "caller cannot be compiled"; break; } if( next_m->name() == vmSymbols::class_initializer_name() ) { msg = "do not compile class initializer (OSR ok)"; break; } if (TraceCompilationPolicy && Verbose) { tty->print("\n\t check caller: "); next_m->print_short_name(tty); tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)next_m(), next_m->code_size()); } current = next; } assert( !current || !current->is_compiled(), "" ); if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg); return current; } RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray* stack) { RFrame* sender = rf->caller(); if (sender && sender->num() == stack->length()) stack->push(sender); return sender; } const char* StackWalkCompPolicy::shouldInline(methodHandle m, float freq, int cnt) { // Allows targeted inlining // positive filter: should send be inlined? returns NULL (--> yes) // or rejection msg int max_size = MaxInlineSize; int cost = m->code_size(); // Check for too many throws (and not too huge) if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) { return NULL; } // bump the max size if the call is frequent if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) { if (TraceFrequencyInlining) { tty->print("(Inlined frequent method)\n"); m->print(); } max_size = FreqInlineSize; } if (cost > max_size) { return (_msg = "too big"); } return NULL; } const char* StackWalkCompPolicy::shouldNotInline(methodHandle m) { // negative filter: should send NOT be inlined? returns NULL (--> inline) or rejection msg if (m->is_abstract()) return (_msg = "abstract method"); // note: we allow ik->is_abstract() if (!instanceKlass::cast(m->method_holder())->is_initialized()) return (_msg = "method holder not initialized"); if (m->is_native()) return (_msg = "native method"); nmethod* m_code = m->code(); if( m_code != NULL && m_code->instructions_size() > InlineSmallCode ) return (_msg = "already compiled into a big method"); // use frequency-based objections only for non-trivial methods if (m->code_size() <= MaxTrivialSize) return NULL; if (UseInterpreter) { // don't use counts with -Xcomp if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed"); if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times"); } if (methodOopDesc::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes"); return NULL; } #endif // COMPILER2