1 /* 2 * Copyright (c) 2000, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_OPTO_CALLGENERATOR_HPP 26 #define SHARE_VM_OPTO_CALLGENERATOR_HPP 27 28 #include "opto/callnode.hpp" 29 #include "opto/compile.hpp" 30 #include "opto/type.hpp" 31 #include "runtime/deoptimization.hpp" 32 33 //---------------------------CallGenerator------------------------------------- 34 // The subclasses of this class handle generation of ideal nodes for 35 // call sites and method entry points. 36 37 class CallGenerator : public ResourceObj { 38 public: 39 enum { 40 xxxunusedxxx 41 }; 42 43 private: 44 ciMethod* _method; // The method being called. 45 46 protected: 47 CallGenerator(ciMethod* method); 48 49 public: 50 // Accessors 51 ciMethod* method() const { return _method; } 52 53 // is_inline: At least some code implementing the method is copied here. 54 virtual bool is_inline() const { return false; } 55 // is_intrinsic: There's a method-specific way of generating the inline code. 56 virtual bool is_intrinsic() const { return false; } 57 // is_parse: Bytecodes implementing the specific method are copied here. 58 virtual bool is_parse() const { return false; } 59 // is_virtual: The call uses the receiver type to select or check the method. 60 virtual bool is_virtual() const { return false; } 61 // is_deferred: The decision whether to inline or not is deferred. 62 virtual bool is_deferred() const { return false; } 63 // is_predicted: Uses an explicit check against a predicted type. 64 virtual bool is_predicted() const { return false; } 65 // is_trap: Does not return to the caller. (E.g., uncommon trap.) 66 virtual bool is_trap() const { return false; } 67 68 // is_late_inline: supports conversion of call into an inline 69 virtual bool is_late_inline() const { return false; } 70 // Replace the call with an inline version of the code 71 virtual void do_late_inline() { ShouldNotReachHere(); } 72 73 virtual CallStaticJavaNode* call_node() const { ShouldNotReachHere(); return NULL; } 74 75 // Note: It is possible for a CG to be both inline and virtual. 76 // (The hashCode intrinsic does a vtable check and an inlined fast path.) 77 78 // Utilities: 79 const TypeFunc* tf() const; 80 81 // The given jvms has state and arguments for a call to my method. 82 // Edges after jvms->argoff() carry all (pre-popped) argument values. 83 // 84 // Update the map with state and return values (if any) and return it. 85 // The return values (0, 1, or 2) must be pushed on the map's stack, 86 // and the sp of the jvms incremented accordingly. 87 // 88 // The jvms is returned on success. Alternatively, a copy of the 89 // given jvms, suitably updated, may be returned, in which case the 90 // caller should discard the original jvms. 91 // 92 // The non-Parm edges of the returned map will contain updated global state, 93 // and one or two edges before jvms->sp() will carry any return values. 94 // Other map edges may contain locals or monitors, and should not 95 // be changed in meaning. 96 // 97 // If the call traps, the returned map must have a control edge of top. 98 // If the call can throw, the returned map must report has_exceptions(). 99 // 100 // If the result is NULL, it means that this CallGenerator was unable 101 // to handle the given call, and another CallGenerator should be consulted. 102 virtual JVMState* generate(JVMState* jvms) = 0; 103 104 // How to generate a call site that is inlined: 105 static CallGenerator* for_inline(ciMethod* m, float expected_uses = -1); 106 // How to generate code for an on-stack replacement handler. 107 static CallGenerator* for_osr(ciMethod* m, int osr_bci); 108 109 // How to generate vanilla out-of-line call sites: 110 static CallGenerator* for_direct_call(ciMethod* m, bool separate_io_projs = false); // static, special 111 static CallGenerator* for_dynamic_call(ciMethod* m); // invokedynamic 112 static CallGenerator* for_virtual_call(ciMethod* m, int vtable_index); // virtual, interface 113 114 // How to generate a replace a direct call with an inline version 115 static CallGenerator* for_late_inline(ciMethod* m, CallGenerator* inline_cg); 116 117 // How to make a call but defer the decision whether to inline or not. 118 static CallGenerator* for_warm_call(WarmCallInfo* ci, 119 CallGenerator* if_cold, 120 CallGenerator* if_hot); 121 122 // How to make a call that optimistically assumes a receiver type: 123 static CallGenerator* for_predicted_call(ciKlass* predicted_receiver, 124 CallGenerator* if_missed, 125 CallGenerator* if_hit, 126 float hit_prob); 127 128 // How to make a call that optimistically assumes a MethodHandle target: 129 static CallGenerator* for_predicted_dynamic_call(ciMethodHandle* predicted_method_handle, 130 CallGenerator* if_missed, 131 CallGenerator* if_hit, 132 float hit_prob); 133 134 // How to make a call that gives up and goes back to the interpreter: 135 static CallGenerator* for_uncommon_trap(ciMethod* m, 136 Deoptimization::DeoptReason reason, 137 Deoptimization::DeoptAction action); 138 139 // Registry for intrinsics: 140 static CallGenerator* for_intrinsic(ciMethod* m); 141 static void register_intrinsic(ciMethod* m, CallGenerator* cg); 142 }; 143 144 class InlineCallGenerator : public CallGenerator { 145 virtual bool is_inline() const { return true; } 146 147 protected: 148 InlineCallGenerator(ciMethod* method) : CallGenerator(method) { } 149 }; 150 151 152 //---------------------------WarmCallInfo-------------------------------------- 153 // A struct to collect information about a given call site. 154 // Helps sort call sites into "hot", "medium", and "cold". 155 // Participates in the queueing of "medium" call sites for possible inlining. 156 class WarmCallInfo : public ResourceObj { 157 private: 158 159 CallNode* _call; // The CallNode which may be inlined. 160 CallGenerator* _hot_cg;// CG for expanding the call node 161 162 // These are the metrics we use to evaluate call sites: 163 164 float _count; // How often do we expect to reach this site? 165 float _profit; // How much time do we expect to save by inlining? 166 float _work; // How long do we expect the average call to take? 167 float _size; // How big do we expect the inlined code to be? 168 169 float _heat; // Combined score inducing total order on call sites. 170 WarmCallInfo* _next; // Next cooler call info in pending queue. 171 172 // Count is the number of times this call site is expected to be executed. 173 // Large count is favorable for inlining, because the extra compilation 174 // work will be amortized more completely. 175 176 // Profit is a rough measure of the amount of time we expect to save 177 // per execution of this site if we inline it. (1.0 == call overhead) 178 // Large profit favors inlining. Negative profit disables inlining. 179 180 // Work is a rough measure of the amount of time a typical out-of-line 181 // call from this site is expected to take. (1.0 == call, no-op, return) 182 // Small work is somewhat favorable for inlining, since methods with 183 // short "hot" traces are more likely to inline smoothly. 184 185 // Size is the number of graph nodes we expect this method to produce, 186 // not counting the inlining of any further warm calls it may include. 187 // Small size favors inlining, since small methods are more likely to 188 // inline smoothly. The size is estimated by examining the native code 189 // if available. The method bytecodes are also examined, assuming 190 // empirically observed node counts for each kind of bytecode. 191 192 // Heat is the combined "goodness" of a site's inlining. If we were 193 // omniscient, it would be the difference of two sums of future execution 194 // times of code emitted for this site (amortized across multiple sites if 195 // sharing applies). The two sums are for versions of this call site with 196 // and without inlining. 197 198 // We approximate this mythical quantity by playing with averages, 199 // rough estimates, and assumptions that history repeats itself. 200 // The basic formula count * profit is heuristically adjusted 201 // by looking at the expected compilation and execution times of 202 // of the inlined call. 203 204 // Note: Some of these metrics may not be present in the final product, 205 // but exist in development builds to experiment with inline policy tuning. 206 207 // This heuristic framework does not model well the very significant 208 // effects of multiple-level inlining. It is possible to see no immediate 209 // profit from inlining X->Y, but to get great profit from a subsequent 210 // inlining X->Y->Z. 211 212 // This framework does not take well into account the problem of N**2 code 213 // size in a clique of mutually inlinable methods. 214 215 WarmCallInfo* next() const { return _next; } 216 void set_next(WarmCallInfo* n) { _next = n; } 217 218 static WarmCallInfo* _always_hot; 219 static WarmCallInfo* _always_cold; 220 221 public: 222 // Because WarmInfo objects live over the entire lifetime of the 223 // Compile object, they are allocated into the comp_arena, which 224 // does not get resource marked or reset during the compile process 225 void *operator new( size_t x, Compile* C ) { return C->comp_arena()->Amalloc(x); } 226 void operator delete( void * ) { } // fast deallocation 227 228 static WarmCallInfo* always_hot(); 229 static WarmCallInfo* always_cold(); 230 231 WarmCallInfo() { 232 _call = NULL; 233 _hot_cg = NULL; 234 _next = NULL; 235 _count = _profit = _work = _size = _heat = 0; 236 } 237 238 CallNode* call() const { return _call; } 239 float count() const { return _count; } 240 float size() const { return _size; } 241 float work() const { return _work; } 242 float profit() const { return _profit; } 243 float heat() const { return _heat; } 244 245 void set_count(float x) { _count = x; } 246 void set_size(float x) { _size = x; } 247 void set_work(float x) { _work = x; } 248 void set_profit(float x) { _profit = x; } 249 void set_heat(float x) { _heat = x; } 250 251 // Load initial heuristics from profiles, etc. 252 // The heuristics can be tweaked further by the caller. 253 void init(JVMState* call_site, ciMethod* call_method, ciCallProfile& profile, float prof_factor); 254 255 static float MAX_VALUE() { return +1.0e10; } 256 static float MIN_VALUE() { return -1.0e10; } 257 258 float compute_heat() const; 259 260 void set_call(CallNode* call) { _call = call; } 261 void set_hot_cg(CallGenerator* cg) { _hot_cg = cg; } 262 263 // Do not queue very hot or very cold calls. 264 // Make very cold ones out of line immediately. 265 // Inline very hot ones immediately. 266 // These queries apply various tunable limits 267 // to the above metrics in a systematic way. 268 // Test for coldness before testing for hotness. 269 bool is_cold() const; 270 bool is_hot() const; 271 272 // Force a warm call to be hot. This worklists the call node for inlining. 273 void make_hot(); 274 275 // Force a warm call to be cold. This worklists the call node for out-of-lining. 276 void make_cold(); 277 278 // A reproducible total ordering, in which heat is the major key. 279 bool warmer_than(WarmCallInfo* that); 280 281 // List management. These methods are called with the list head, 282 // and return the new list head, inserting or removing the receiver. 283 WarmCallInfo* insert_into(WarmCallInfo* head); 284 WarmCallInfo* remove_from(WarmCallInfo* head); 285 286 #ifndef PRODUCT 287 void print() const; 288 void print_all() const; 289 int count_all() const; 290 #endif 291 }; 292 293 #endif // SHARE_VM_OPTO_CALLGENERATOR_HPP