/* * Copyright 2000-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ //---------------------------CallGenerator------------------------------------- // The subclasses of this class handle generation of ideal nodes for // call sites and method entry points. class CallGenerator : public ResourceObj { public: enum { xxxunusedxxx }; private: ciMethod* _method; // The method being called. protected: CallGenerator(ciMethod* method); public: // Accessors ciMethod* method() const { return _method; } // is_inline: At least some code implementing the method is copied here. virtual bool is_inline() const { return false; } // is_intrinsic: There's a method-specific way of generating the inline code. virtual bool is_intrinsic() const { return false; } // is_parse: Bytecodes implementing the specific method are copied here. virtual bool is_parse() const { return false; } // is_virtual: The call uses the receiver type to select or check the method. virtual bool is_virtual() const { return false; } // is_deferred: The decision whether to inline or not is deferred. virtual bool is_deferred() const { return false; } // is_predicted: Uses an explicit check against a predicted type. virtual bool is_predicted() const { return false; } // is_trap: Does not return to the caller. (E.g., uncommon trap.) virtual bool is_trap() const { return false; } // is_late_inline: supports conversion of call into an inline virtual bool is_late_inline() const { return false; } // Replace the call with an inline version of the code virtual void do_late_inline() { ShouldNotReachHere(); } virtual CallStaticJavaNode* call_node() const { ShouldNotReachHere(); return NULL; } // Note: It is possible for a CG to be both inline and virtual. // (The hashCode intrinsic does a vtable check and an inlined fast path.) // Utilities: const TypeFunc* tf() const; // The given jvms has state and arguments for a call to my method. // Edges after jvms->argoff() carry all (pre-popped) argument values. // // Update the map with state and return values (if any) and return it. // The return values (0, 1, or 2) must be pushed on the map's stack, // and the sp of the jvms incremented accordingly. // // The jvms is returned on success. Alternatively, a copy of the // given jvms, suitably updated, may be returned, in which case the // caller should discard the original jvms. // // The non-Parm edges of the returned map will contain updated global state, // and one or two edges before jvms->sp() will carry any return values. // Other map edges may contain locals or monitors, and should not // be changed in meaning. // // If the call traps, the returned map must have a control edge of top. // If the call can throw, the returned map must report has_exceptions(). // // If the result is NULL, it means that this CallGenerator was unable // to handle the given call, and another CallGenerator should be consulted. virtual JVMState* generate(JVMState* jvms) = 0; // How to generate a call site that is inlined: static CallGenerator* for_inline(ciMethod* m, float expected_uses = -1); // How to generate code for an on-stack replacement handler. static CallGenerator* for_osr(ciMethod* m, int osr_bci); // How to generate vanilla out-of-line call sites: static CallGenerator* for_direct_call(ciMethod* m, bool separate_io_projs = false); // static, special static CallGenerator* for_virtual_call(ciMethod* m, int vtable_index); // virtual, interface // How to generate a replace a direct call with an inline version static CallGenerator* for_late_inline(ciMethod* m, CallGenerator* inline_cg); // How to make a call but defer the decision whether to inline or not. static CallGenerator* for_warm_call(WarmCallInfo* ci, CallGenerator* if_cold, CallGenerator* if_hot); // How to make a call that optimistically assumes a receiver type: static CallGenerator* for_predicted_call(ciKlass* predicted_receiver, CallGenerator* if_missed, CallGenerator* if_hit, float hit_prob); // How to make a call that gives up and goes back to the interpreter: static CallGenerator* for_uncommon_trap(ciMethod* m, Deoptimization::DeoptReason reason, Deoptimization::DeoptAction action); // Registry for intrinsics: static CallGenerator* for_intrinsic(ciMethod* m); static void register_intrinsic(ciMethod* m, CallGenerator* cg); }; class InlineCallGenerator : public CallGenerator { virtual bool is_inline() const { return true; } protected: InlineCallGenerator(ciMethod* method) : CallGenerator(method) { } }; //---------------------------WarmCallInfo-------------------------------------- // A struct to collect information about a given call site. // Helps sort call sites into "hot", "medium", and "cold". // Participates in the queueing of "medium" call sites for possible inlining. class WarmCallInfo : public ResourceObj { private: CallNode* _call; // The CallNode which may be inlined. CallGenerator* _hot_cg;// CG for expanding the call node // These are the metrics we use to evaluate call sites: float _count; // How often do we expect to reach this site? float _profit; // How much time do we expect to save by inlining? float _work; // How long do we expect the average call to take? float _size; // How big do we expect the inlined code to be? float _heat; // Combined score inducing total order on call sites. WarmCallInfo* _next; // Next cooler call info in pending queue. // Count is the number of times this call site is expected to be executed. // Large count is favorable for inlining, because the extra compilation // work will be amortized more completely. // Profit is a rough measure of the amount of time we expect to save // per execution of this site if we inline it. (1.0 == call overhead) // Large profit favors inlining. Negative profit disables inlining. // Work is a rough measure of the amount of time a typical out-of-line // call from this site is expected to take. (1.0 == call, no-op, return) // Small work is somewhat favorable for inlining, since methods with // short "hot" traces are more likely to inline smoothly. // Size is the number of graph nodes we expect this method to produce, // not counting the inlining of any further warm calls it may include. // Small size favors inlining, since small methods are more likely to // inline smoothly. The size is estimated by examining the native code // if available. The method bytecodes are also examined, assuming // empirically observed node counts for each kind of bytecode. // Heat is the combined "goodness" of a site's inlining. If we were // omniscient, it would be the difference of two sums of future execution // times of code emitted for this site (amortized across multiple sites if // sharing applies). The two sums are for versions of this call site with // and without inlining. // We approximate this mythical quantity by playing with averages, // rough estimates, and assumptions that history repeats itself. // The basic formula count * profit is heuristically adjusted // by looking at the expected compilation and execution times of // of the inlined call. // Note: Some of these metrics may not be present in the final product, // but exist in development builds to experiment with inline policy tuning. // This heuristic framework does not model well the very significant // effects of multiple-level inlining. It is possible to see no immediate // profit from inlining X->Y, but to get great profit from a subsequent // inlining X->Y->Z. // This framework does not take well into account the problem of N**2 code // size in a clique of mutually inlinable methods. WarmCallInfo* next() const { return _next; } void set_next(WarmCallInfo* n) { _next = n; } static WarmCallInfo* _always_hot; static WarmCallInfo* _always_cold; public: // Because WarmInfo objects live over the entire lifetime of the // Compile object, they are allocated into the comp_arena, which // does not get resource marked or reset during the compile process void *operator new( size_t x, Compile* C ) { return C->comp_arena()->Amalloc(x); } void operator delete( void * ) { } // fast deallocation static WarmCallInfo* always_hot(); static WarmCallInfo* always_cold(); WarmCallInfo() { _call = NULL; _hot_cg = NULL; _next = NULL; _count = _profit = _work = _size = _heat = 0; } CallNode* call() const { return _call; } float count() const { return _count; } float size() const { return _size; } float work() const { return _work; } float profit() const { return _profit; } float heat() const { return _heat; } void set_count(float x) { _count = x; } void set_size(float x) { _size = x; } void set_work(float x) { _work = x; } void set_profit(float x) { _profit = x; } void set_heat(float x) { _heat = x; } // Load initial heuristics from profiles, etc. // The heuristics can be tweaked further by the caller. void init(JVMState* call_site, ciMethod* call_method, ciCallProfile& profile, float prof_factor); static float MAX_VALUE() { return +1.0e10; } static float MIN_VALUE() { return -1.0e10; } float compute_heat() const; void set_call(CallNode* call) { _call = call; } void set_hot_cg(CallGenerator* cg) { _hot_cg = cg; } // Do not queue very hot or very cold calls. // Make very cold ones out of line immediately. // Inline very hot ones immediately. // These queries apply various tunable limits // to the above metrics in a systematic way. // Test for coldness before testing for hotness. bool is_cold() const; bool is_hot() const; // Force a warm call to be hot. This worklists the call node for inlining. void make_hot(); // Force a warm call to be cold. This worklists the call node for out-of-lining. void make_cold(); // A reproducible total ordering, in which heat is the major key. bool warmer_than(WarmCallInfo* that); // List management. These methods are called with the list head, // and return the new list head, inserting or removing the receiver. WarmCallInfo* insert_into(WarmCallInfo* head); WarmCallInfo* remove_from(WarmCallInfo* head); #ifndef PRODUCT void print() const; void print_all() const; int count_all() const; #endif };