duke@435: /*
duke@435:  * Copyright 2000-2007 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: # include "incls/_precompiled.incl"
duke@435: # include "incls/_compilationPolicy.cpp.incl"
duke@435: 
duke@435: CompilationPolicy* CompilationPolicy::_policy;
duke@435: elapsedTimer       CompilationPolicy::_accumulated_time;
duke@435: bool               CompilationPolicy::_in_vm_startup;
duke@435: 
duke@435: // Determine compilation policy based on command line argument
duke@435: void compilationPolicy_init() {
duke@435:   CompilationPolicy::set_in_vm_startup(DelayCompilationDuringStartup);
duke@435: 
duke@435:   switch(CompilationPolicyChoice) {
duke@435:   case 0:
duke@435:     CompilationPolicy::set_policy(new SimpleCompPolicy());
duke@435:     break;
duke@435: 
duke@435:   case 1:
duke@435: #ifdef COMPILER2
duke@435:     CompilationPolicy::set_policy(new StackWalkCompPolicy());
duke@435: #else
duke@435:     Unimplemented();
duke@435: #endif
duke@435:     break;
duke@435: 
duke@435:   default:
duke@435:     fatal("CompilationPolicyChoice must be in the range: [0-1]");
duke@435:   }
duke@435: }
duke@435: 
duke@435: void CompilationPolicy::completed_vm_startup() {
duke@435:   if (TraceCompilationPolicy) {
duke@435:     tty->print("CompilationPolicy: completed vm startup.\n");
duke@435:   }
duke@435:   _in_vm_startup = false;
duke@435: }
duke@435: 
duke@435: // Returns true if m must be compiled before executing it
duke@435: // This is intended to force compiles for methods (usually for
duke@435: // debugging) that would otherwise be interpreted for some reason.
duke@435: bool CompilationPolicy::mustBeCompiled(methodHandle m) {
duke@435:   if (m->has_compiled_code()) return false;       // already compiled
duke@435:   if (!canBeCompiled(m))      return false;
duke@435: 
duke@435:   return !UseInterpreter ||                                              // must compile all methods
duke@435:          (UseCompiler && AlwaysCompileLoopMethods && m->has_loops()); // eagerly compile loop methods
duke@435: }
duke@435: 
duke@435: // Returns true if m is allowed to be compiled
duke@435: bool CompilationPolicy::canBeCompiled(methodHandle m) {
duke@435:   if (m->is_abstract()) return false;
duke@435:   if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
duke@435: 
duke@435:   return !m->is_not_compilable();
duke@435: }
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: void CompilationPolicy::print_time() {
duke@435:   tty->print_cr ("Accumulated compilationPolicy times:");
duke@435:   tty->print_cr ("---------------------------");
duke@435:   tty->print_cr ("  Total: %3.3f sec.", _accumulated_time.seconds());
duke@435: }
duke@435: 
duke@435: static void trace_osr_completion(nmethod* osr_nm) {
duke@435:   if (TraceOnStackReplacement) {
duke@435:     if (osr_nm == NULL) tty->print_cr("compilation failed");
duke@435:     else tty->print_cr("nmethod " INTPTR_FORMAT, osr_nm);
duke@435:   }
duke@435: }
duke@435: #endif // !PRODUCT
duke@435: 
duke@435: void CompilationPolicy::reset_counter_for_invocation_event(methodHandle m) {
duke@435:   // Make sure invocation and backedge counter doesn't overflow again right away
duke@435:   // as would be the case for native methods.
duke@435: 
duke@435:   // BUT also make sure the method doesn't look like it was never executed.
duke@435:   // Set carry bit and reduce counter's value to min(count, CompileThreshold/2).
duke@435:   m->invocation_counter()->set_carry();
duke@435:   m->backedge_counter()->set_carry();
duke@435: 
duke@435:   assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed");
duke@435: }
duke@435: 
duke@435: void CompilationPolicy::reset_counter_for_back_branch_event(methodHandle m) {
duke@435:   // Delay next back-branch event but pump up invocation counter to triger
duke@435:   // whole method compilation.
duke@435:   InvocationCounter* i = m->invocation_counter();
duke@435:   InvocationCounter* b = m->backedge_counter();
duke@435: 
duke@435:   // Don't set invocation_counter's value too low otherwise the method will
duke@435:   // look like immature (ic < ~5300) which prevents the inlining based on
duke@435:   // the type profiling.
duke@435:   i->set(i->state(), CompileThreshold);
duke@435:   // Don't reset counter too low - it is used to check if OSR method is ready.
duke@435:   b->set(b->state(), CompileThreshold / 2);
duke@435: }
duke@435: 
duke@435: // SimpleCompPolicy - compile current method
duke@435: 
duke@435: void SimpleCompPolicy::method_invocation_event( methodHandle m, TRAPS) {
duke@435:   assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
duke@435: 
duke@435:   int hot_count = m->invocation_count();
duke@435:   reset_counter_for_invocation_event(m);
duke@435:   const char* comment = "count";
duke@435: 
duke@435:   if (!delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler) {
duke@435:     nmethod* nm = m->code();
duke@435:     if (nm == NULL ) {
duke@435:       const char* comment = "count";
duke@435:       CompileBroker::compile_method(m, InvocationEntryBci,
duke@435:                                     m, hot_count, comment, CHECK);
duke@435:     } else {
duke@435: #ifdef TIERED
duke@435: 
duke@435:       if (nm->is_compiled_by_c1()) {
duke@435:         const char* comment = "tier1 overflow";
duke@435:         CompileBroker::compile_method(m, InvocationEntryBci,
duke@435:                                       m, hot_count, comment, CHECK);
duke@435:       }
duke@435: #endif // TIERED
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void SimpleCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) {
duke@435:   assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
duke@435: 
duke@435:   int hot_count = m->backedge_count();
duke@435:   const char* comment = "backedge_count";
duke@435: 
duke@435:   if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m)) {
duke@435:     CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK);
duke@435: 
duke@435:     NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));)
duke@435:   }
duke@435: }
duke@435: 
duke@435: int SimpleCompPolicy::compilation_level(methodHandle m, int branch_bci)
duke@435: {
duke@435: #ifdef TIERED
duke@435:   if (!TieredCompilation) {
duke@435:     return CompLevel_highest_tier;
duke@435:   }
duke@435:   if (/* m()->tier1_compile_done() && */
duke@435:      // QQQ HACK FIX ME set tier1_compile_done!!
duke@435:       !m()->is_native()) {
duke@435:     // Grab the nmethod so it doesn't go away while it's being queried
duke@435:     nmethod* code = m()->code();
duke@435:     if (code != NULL && code->is_compiled_by_c1()) {
duke@435:       return CompLevel_highest_tier;
duke@435:     }
duke@435:   }
duke@435:   return CompLevel_fast_compile;
duke@435: #else
duke@435:   return CompLevel_highest_tier;
duke@435: #endif // TIERED
duke@435: }
duke@435: 
duke@435: // StackWalkCompPolicy - walk up stack to find a suitable method to compile
duke@435: 
duke@435: #ifdef COMPILER2
duke@435: const char* StackWalkCompPolicy::_msg = NULL;
duke@435: 
duke@435: 
duke@435: // Consider m for compilation
duke@435: void StackWalkCompPolicy::method_invocation_event(methodHandle m, TRAPS) {
duke@435:   assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
duke@435: 
duke@435:   int hot_count = m->invocation_count();
duke@435:   reset_counter_for_invocation_event(m);
duke@435:   const char* comment = "count";
duke@435: 
duke@435:   if (m->code() == NULL && !delayCompilationDuringStartup() && canBeCompiled(m) && UseCompiler) {
duke@435:     ResourceMark rm(THREAD);
duke@435:     JavaThread *thread = (JavaThread*)THREAD;
duke@435:     frame       fr     = thread->last_frame();
duke@435:     assert(fr.is_interpreted_frame(), "must be interpreted");
duke@435:     assert(fr.interpreter_frame_method() == m(), "bad method");
duke@435: 
duke@435:     if (TraceCompilationPolicy) {
duke@435:       tty->print("method invocation trigger: ");
duke@435:       m->print_short_name(tty);
duke@435:       tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)m(), m->code_size());
duke@435:     }
duke@435:     RegisterMap reg_map(thread, false);
duke@435:     javaVFrame* triggerVF = thread->last_java_vframe(&reg_map);
duke@435:     // triggerVF is the frame that triggered its counter
duke@435:     RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m);
duke@435: 
duke@435:     if (first->top_method()->code() != NULL) {
duke@435:       // called obsolete method/nmethod -- no need to recompile
duke@435:       if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, first->top_method()->code());
duke@435:     } else if (compilation_level(m, InvocationEntryBci) == CompLevel_fast_compile) {
duke@435:       // Tier1 compilation policy avaoids stack walking.
duke@435:       CompileBroker::compile_method(m, InvocationEntryBci,
duke@435:                                     m, hot_count, comment, CHECK);
duke@435:     } else {
duke@435:       if (TimeCompilationPolicy) accumulated_time()->start();
duke@435:       GrowableArray<RFrame*>* stack = new GrowableArray<RFrame*>(50);
duke@435:       stack->push(first);
duke@435:       RFrame* top = findTopInlinableFrame(stack);
duke@435:       if (TimeCompilationPolicy) accumulated_time()->stop();
duke@435:       assert(top != NULL, "findTopInlinableFrame returned null");
duke@435:       if (TraceCompilationPolicy) top->print();
duke@435:       CompileBroker::compile_method(top->top_method(), InvocationEntryBci,
duke@435:                                     m, hot_count, comment, CHECK);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void StackWalkCompPolicy::method_back_branch_event(methodHandle m, int branch_bci, int loop_top_bci, TRAPS) {
duke@435:   assert(UseCompiler || CompileTheWorld, "UseCompiler should be set by now.");
duke@435: 
duke@435:   int hot_count = m->backedge_count();
duke@435:   const char* comment = "backedge_count";
duke@435: 
duke@435:   if (!m->is_not_osr_compilable() && !delayCompilationDuringStartup() && canBeCompiled(m)) {
duke@435:     CompileBroker::compile_method(m, loop_top_bci, m, hot_count, comment, CHECK);
duke@435: 
duke@435:     NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(loop_top_bci));)
duke@435:   }
duke@435: }
duke@435: 
duke@435: int StackWalkCompPolicy::compilation_level(methodHandle m, int osr_bci)
duke@435: {
duke@435:   int comp_level = CompLevel_full_optimization;
duke@435:   if (TieredCompilation && osr_bci == InvocationEntryBci) {
duke@435:     if (CompileTheWorld) {
duke@435:       // Under CTW, the first compile is tier1, the second tier2
duke@435:       if (m->highest_tier_compile() == CompLevel_none) {
duke@435:         comp_level = CompLevel_fast_compile;
duke@435:       }
duke@435:     } else if (!m->has_osr_nmethod()) {
duke@435:       // Before tier1 is done, use invocation_count + backedge_count to
duke@435:       // compare against the threshold.  After that, the counters may/will
duke@435:       // be reset, so rely on the straight interpreter_invocation_count.
duke@435:       if (m->highest_tier_compile() == CompLevel_initial_compile) {
duke@435:         if (m->interpreter_invocation_count() < Tier2CompileThreshold) {
duke@435:           comp_level = CompLevel_fast_compile;
duke@435:         }
duke@435:       } else if (m->invocation_count() + m->backedge_count() <
duke@435:                  Tier2CompileThreshold) {
duke@435:         comp_level = CompLevel_fast_compile;
duke@435:       }
duke@435:     }
duke@435: 
duke@435:   }
duke@435:   return comp_level;
duke@435: }
duke@435: 
duke@435: 
duke@435: RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray<RFrame*>* stack) {
duke@435:   // go up the stack until finding a frame that (probably) won't be inlined
duke@435:   // into its caller
duke@435:   RFrame* current = stack->at(0); // current choice for stopping
duke@435:   assert( current && !current->is_compiled(), "" );
duke@435:   const char* msg = NULL;
duke@435: 
duke@435:   while (1) {
duke@435: 
duke@435:     // before going up the stack further, check if doing so would get us into
duke@435:     // compiled code
duke@435:     RFrame* next = senderOf(current, stack);
duke@435:     if( !next )               // No next frame up the stack?
duke@435:       break;                  // Then compile with current frame
duke@435: 
duke@435:     methodHandle m = current->top_method();
duke@435:     methodHandle next_m = next->top_method();
duke@435: 
duke@435:     if (TraceCompilationPolicy && Verbose) {
duke@435:       tty->print("[caller: ");
duke@435:       next_m->print_short_name(tty);
duke@435:       tty->print("] ");
duke@435:     }
duke@435: 
duke@435:     if( !Inline ) {           // Inlining turned off
duke@435:       msg = "Inlining turned off";
duke@435:       break;
duke@435:     }
duke@435:     if (next_m->is_not_compilable()) { // Did fail to compile this before/
duke@435:       msg = "caller not compilable";
duke@435:       break;
duke@435:     }
duke@435:     if (next->num() > MaxRecompilationSearchLength) {
duke@435:       // don't go up too high when searching for recompilees
duke@435:       msg = "don't go up any further: > MaxRecompilationSearchLength";
duke@435:       break;
duke@435:     }
duke@435:     if (next->distance() > MaxInterpretedSearchLength) {
duke@435:       // don't go up too high when searching for recompilees
duke@435:       msg = "don't go up any further: next > MaxInterpretedSearchLength";
duke@435:       break;
duke@435:     }
duke@435:     // Compiled frame above already decided not to inline;
duke@435:     // do not recompile him.
duke@435:     if (next->is_compiled()) {
duke@435:       msg = "not going up into optimized code";
duke@435:       break;
duke@435:     }
duke@435: 
duke@435:     // Interpreted frame above us was already compiled.  Do not force
duke@435:     // a recompile, although if the frame above us runs long enough an
duke@435:     // OSR might still happen.
duke@435:     if( current->is_interpreted() && next_m->has_compiled_code() ) {
duke@435:       msg = "not going up -- already compiled caller";
duke@435:       break;
duke@435:     }
duke@435: 
duke@435:     // Compute how frequent this call site is.  We have current method 'm'.
duke@435:     // We know next method 'next_m' is interpreted.  Find the call site and
duke@435:     // check the various invocation counts.
duke@435:     int invcnt = 0;             // Caller counts
duke@435:     if (ProfileInterpreter) {
duke@435:       invcnt = next_m->interpreter_invocation_count();
duke@435:     }
duke@435:     int cnt = 0;                // Call site counts
duke@435:     if (ProfileInterpreter && next_m->method_data() != NULL) {
duke@435:       ResourceMark rm;
duke@435:       int bci = next->top_vframe()->bci();
duke@435:       ProfileData* data = next_m->method_data()->bci_to_data(bci);
duke@435:       if (data != NULL && data->is_CounterData())
duke@435:         cnt = data->as_CounterData()->count();
duke@435:     }
duke@435: 
duke@435:     // Caller counts / call-site counts; i.e. is this call site
duke@435:     // a hot call site for method next_m?
duke@435:     int freq = (invcnt) ? cnt/invcnt : cnt;
duke@435: 
duke@435:     // Check size and frequency limits
duke@435:     if ((msg = shouldInline(m, freq, cnt)) != NULL) {
duke@435:       break;
duke@435:     }
duke@435:     // Check inlining negative tests
duke@435:     if ((msg = shouldNotInline(m)) != NULL) {
duke@435:       break;
duke@435:     }
duke@435: 
duke@435: 
duke@435:     // If the caller method is too big or something then we do not want to
duke@435:     // compile it just to inline a method
duke@435:     if (!canBeCompiled(next_m)) {
duke@435:       msg = "caller cannot be compiled";
duke@435:       break;
duke@435:     }
duke@435: 
duke@435:     if( next_m->name() == vmSymbols::class_initializer_name() ) {
duke@435:       msg = "do not compile class initializer (OSR ok)";
duke@435:       break;
duke@435:     }
duke@435: 
duke@435:     if (TraceCompilationPolicy && Verbose) {
duke@435:       tty->print("\n\t     check caller: ");
duke@435:       next_m->print_short_name(tty);
duke@435:       tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", (address)next_m(), next_m->code_size());
duke@435:     }
duke@435: 
duke@435:     current = next;
duke@435:   }
duke@435: 
duke@435:   assert( !current || !current->is_compiled(), "" );
duke@435: 
duke@435:   if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg);
duke@435: 
duke@435:   return current;
duke@435: }
duke@435: 
duke@435: RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray<RFrame*>* stack) {
duke@435:   RFrame* sender = rf->caller();
duke@435:   if (sender && sender->num() == stack->length()) stack->push(sender);
duke@435:   return sender;
duke@435: }
duke@435: 
duke@435: 
duke@435: const char* StackWalkCompPolicy::shouldInline(methodHandle m, float freq, int cnt) {
duke@435:   // Allows targeted inlining
duke@435:   // positive filter: should send be inlined?  returns NULL (--> yes)
duke@435:   // or rejection msg
duke@435:   int max_size = MaxInlineSize;
duke@435:   int cost = m->code_size();
duke@435: 
duke@435:   // Check for too many throws (and not too huge)
duke@435:   if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) {
duke@435:     return NULL;
duke@435:   }
duke@435: 
duke@435:   // bump the max size if the call is frequent
duke@435:   if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) {
duke@435:     if (TraceFrequencyInlining) {
duke@435:       tty->print("(Inlined frequent method)\n");
duke@435:       m->print();
duke@435:     }
duke@435:     max_size = FreqInlineSize;
duke@435:   }
duke@435:   if (cost > max_size) {
duke@435:     return (_msg = "too big");
duke@435:   }
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: 
duke@435: const char* StackWalkCompPolicy::shouldNotInline(methodHandle m) {
duke@435:   // negative filter: should send NOT be inlined?  returns NULL (--> inline) or rejection msg
duke@435:   if (m->is_abstract()) return (_msg = "abstract method");
duke@435:   // note: we allow ik->is_abstract()
duke@435:   if (!instanceKlass::cast(m->method_holder())->is_initialized()) return (_msg = "method holder not initialized");
duke@435:   if (m->is_native()) return (_msg = "native method");
duke@435:   nmethod* m_code = m->code();
duke@435:   if( m_code != NULL && m_code->instructions_size() > InlineSmallCode )
duke@435:     return (_msg = "already compiled into a big method");
duke@435: 
duke@435:   // use frequency-based objections only for non-trivial methods
duke@435:   if (m->code_size() <= MaxTrivialSize) return NULL;
duke@435:   if (UseInterpreter) {     // don't use counts with -Xcomp
duke@435:     if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed");
duke@435:     if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times");
duke@435:   }
duke@435:   if (methodOopDesc::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes");
duke@435: 
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: 
duke@435: 
duke@435: #endif // COMPILER2