callGenerator.hpp revision 6571:9be8f500449d
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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 "compiler/compileBroker.hpp" 29#include "opto/callnode.hpp" 30#include "opto/compile.hpp" 31#include "opto/type.hpp" 32#include "runtime/deoptimization.hpp" 33 34//---------------------------CallGenerator------------------------------------- 35// The subclasses of this class handle generation of ideal nodes for 36// call sites and method entry points. 37 38class CallGenerator : public ResourceObj { 39 public: 40 enum { 41 xxxunusedxxx 42 }; 43 44 private: 45 ciMethod* _method; // The method being called. 46 47 protected: 48 CallGenerator(ciMethod* method) : _method(method) {} 49 50 public: 51 // Accessors 52 ciMethod* method() const { return _method; } 53 54 // is_inline: At least some code implementing the method is copied here. 55 virtual bool is_inline() const { return false; } 56 // is_intrinsic: There's a method-specific way of generating the inline code. 57 virtual bool is_intrinsic() const { return false; } 58 // is_parse: Bytecodes implementing the specific method are copied here. 59 virtual bool is_parse() const { return false; } 60 // is_virtual: The call uses the receiver type to select or check the method. 61 virtual bool is_virtual() const { return false; } 62 // is_deferred: The decision whether to inline or not is deferred. 63 virtual bool is_deferred() const { return false; } 64 // is_predicated: Uses an explicit check (predicate). 65 virtual bool is_predicated() const { return false; } 66 virtual int predicates_count() const { return 0; } 67 // is_trap: Does not return to the caller. (E.g., uncommon trap.) 68 virtual bool is_trap() const { return false; } 69 // does_virtual_dispatch: Should try inlining as normal method first. 70 virtual bool does_virtual_dispatch() const { return false; } 71 72 // is_late_inline: supports conversion of call into an inline 73 virtual bool is_late_inline() const { return false; } 74 // same but for method handle calls 75 virtual bool is_mh_late_inline() const { return false; } 76 virtual bool is_string_late_inline() const{ return false; } 77 78 // for method handle calls: have we tried inlinining the call already? 79 virtual bool already_attempted() const { ShouldNotReachHere(); return false; } 80 81 // Replace the call with an inline version of the code 82 virtual void do_late_inline() { ShouldNotReachHere(); } 83 84 virtual CallStaticJavaNode* call_node() const { ShouldNotReachHere(); return NULL; } 85 86 virtual void set_unique_id(jlong id) { fatal("unique id only for late inlines"); }; 87 virtual jlong unique_id() const { fatal("unique id only for late inlines"); return 0; }; 88 89 // Note: It is possible for a CG to be both inline and virtual. 90 // (The hashCode intrinsic does a vtable check and an inlined fast path.) 91 92 // Utilities: 93 const TypeFunc* tf() const; 94 95 // The given jvms has state and arguments for a call to my method. 96 // Edges after jvms->argoff() carry all (pre-popped) argument values. 97 // 98 // Update the map with state and return values (if any) and return it. 99 // The return values (0, 1, or 2) must be pushed on the map's stack, 100 // and the sp of the jvms incremented accordingly. 101 // 102 // The jvms is returned on success. Alternatively, a copy of the 103 // given jvms, suitably updated, may be returned, in which case the 104 // caller should discard the original jvms. 105 // 106 // The non-Parm edges of the returned map will contain updated global state, 107 // and one or two edges before jvms->sp() will carry any return values. 108 // Other map edges may contain locals or monitors, and should not 109 // be changed in meaning. 110 // 111 // If the call traps, the returned map must have a control edge of top. 112 // If the call can throw, the returned map must report has_exceptions(). 113 // 114 // If the result is NULL, it means that this CallGenerator was unable 115 // to handle the given call, and another CallGenerator should be consulted. 116 virtual JVMState* generate(JVMState* jvms) = 0; 117 118 // How to generate a call site that is inlined: 119 static CallGenerator* for_inline(ciMethod* m, float expected_uses = -1); 120 // How to generate code for an on-stack replacement handler. 121 static CallGenerator* for_osr(ciMethod* m, int osr_bci); 122 123 // How to generate vanilla out-of-line call sites: 124 static CallGenerator* for_direct_call(ciMethod* m, bool separate_io_projs = false); // static, special 125 static CallGenerator* for_virtual_call(ciMethod* m, int vtable_index); // virtual, interface 126 static CallGenerator* for_dynamic_call(ciMethod* m); // invokedynamic 127 128 static CallGenerator* for_method_handle_call( JVMState* jvms, ciMethod* caller, ciMethod* callee, bool delayed_forbidden); 129 static CallGenerator* for_method_handle_inline(JVMState* jvms, ciMethod* caller, ciMethod* callee, bool& input_not_const); 130 131 // How to generate a replace a direct call with an inline version 132 static CallGenerator* for_late_inline(ciMethod* m, CallGenerator* inline_cg); 133 static CallGenerator* for_mh_late_inline(ciMethod* caller, ciMethod* callee, bool input_not_const); 134 static CallGenerator* for_string_late_inline(ciMethod* m, CallGenerator* inline_cg); 135 static CallGenerator* for_boxing_late_inline(ciMethod* m, CallGenerator* inline_cg); 136 137 // How to make a call but defer the decision whether to inline or not. 138 static CallGenerator* for_warm_call(WarmCallInfo* ci, 139 CallGenerator* if_cold, 140 CallGenerator* if_hot); 141 142 // How to make a call that optimistically assumes a receiver type: 143 static CallGenerator* for_predicted_call(ciKlass* predicted_receiver, 144 CallGenerator* if_missed, 145 CallGenerator* if_hit, 146 float hit_prob); 147 148 // How to make a call that optimistically assumes a MethodHandle target: 149 static CallGenerator* for_predicted_dynamic_call(ciMethodHandle* predicted_method_handle, 150 CallGenerator* if_missed, 151 CallGenerator* if_hit, 152 float hit_prob); 153 154 // How to make a call that gives up and goes back to the interpreter: 155 static CallGenerator* for_uncommon_trap(ciMethod* m, 156 Deoptimization::DeoptReason reason, 157 Deoptimization::DeoptAction action); 158 159 // Registry for intrinsics: 160 static CallGenerator* for_intrinsic(ciMethod* m); 161 static void register_intrinsic(ciMethod* m, CallGenerator* cg); 162 static CallGenerator* for_predicated_intrinsic(CallGenerator* intrinsic, 163 CallGenerator* cg); 164 virtual Node* generate_predicate(JVMState* jvms, int predicate) { return NULL; }; 165 166 virtual void print_inlining_late(const char* msg) { ShouldNotReachHere(); } 167 168 static void print_inlining(Compile* C, ciMethod* callee, int inline_level, int bci, const char* msg) { 169 if (C->print_inlining()) { 170 C->print_inlining(callee, inline_level, bci, msg); 171 } 172 } 173}; 174 175 176//------------------------InlineCallGenerator---------------------------------- 177class InlineCallGenerator : public CallGenerator { 178 protected: 179 InlineCallGenerator(ciMethod* method) : CallGenerator(method) {} 180 181 public: 182 virtual bool is_inline() const { return true; } 183}; 184 185 186//---------------------------WarmCallInfo-------------------------------------- 187// A struct to collect information about a given call site. 188// Helps sort call sites into "hot", "medium", and "cold". 189// Participates in the queueing of "medium" call sites for possible inlining. 190class WarmCallInfo : public ResourceObj { 191 private: 192 193 CallNode* _call; // The CallNode which may be inlined. 194 CallGenerator* _hot_cg;// CG for expanding the call node 195 196 // These are the metrics we use to evaluate call sites: 197 198 float _count; // How often do we expect to reach this site? 199 float _profit; // How much time do we expect to save by inlining? 200 float _work; // How long do we expect the average call to take? 201 float _size; // How big do we expect the inlined code to be? 202 203 float _heat; // Combined score inducing total order on call sites. 204 WarmCallInfo* _next; // Next cooler call info in pending queue. 205 206 // Count is the number of times this call site is expected to be executed. 207 // Large count is favorable for inlining, because the extra compilation 208 // work will be amortized more completely. 209 210 // Profit is a rough measure of the amount of time we expect to save 211 // per execution of this site if we inline it. (1.0 == call overhead) 212 // Large profit favors inlining. Negative profit disables inlining. 213 214 // Work is a rough measure of the amount of time a typical out-of-line 215 // call from this site is expected to take. (1.0 == call, no-op, return) 216 // Small work is somewhat favorable for inlining, since methods with 217 // short "hot" traces are more likely to inline smoothly. 218 219 // Size is the number of graph nodes we expect this method to produce, 220 // not counting the inlining of any further warm calls it may include. 221 // Small size favors inlining, since small methods are more likely to 222 // inline smoothly. The size is estimated by examining the native code 223 // if available. The method bytecodes are also examined, assuming 224 // empirically observed node counts for each kind of bytecode. 225 226 // Heat is the combined "goodness" of a site's inlining. If we were 227 // omniscient, it would be the difference of two sums of future execution 228 // times of code emitted for this site (amortized across multiple sites if 229 // sharing applies). The two sums are for versions of this call site with 230 // and without inlining. 231 232 // We approximate this mythical quantity by playing with averages, 233 // rough estimates, and assumptions that history repeats itself. 234 // The basic formula count * profit is heuristically adjusted 235 // by looking at the expected compilation and execution times of 236 // of the inlined call. 237 238 // Note: Some of these metrics may not be present in the final product, 239 // but exist in development builds to experiment with inline policy tuning. 240 241 // This heuristic framework does not model well the very significant 242 // effects of multiple-level inlining. It is possible to see no immediate 243 // profit from inlining X->Y, but to get great profit from a subsequent 244 // inlining X->Y->Z. 245 246 // This framework does not take well into account the problem of N**2 code 247 // size in a clique of mutually inlinable methods. 248 249 WarmCallInfo* next() const { return _next; } 250 void set_next(WarmCallInfo* n) { _next = n; } 251 252 static WarmCallInfo _always_hot; 253 static WarmCallInfo _always_cold; 254 255 // Constructor intitialization of always_hot and always_cold 256 WarmCallInfo(float c, float p, float w, float s) { 257 _call = NULL; 258 _hot_cg = NULL; 259 _next = NULL; 260 _count = c; 261 _profit = p; 262 _work = w; 263 _size = s; 264 _heat = 0; 265 } 266 267 public: 268 // Because WarmInfo objects live over the entire lifetime of the 269 // Compile object, they are allocated into the comp_arena, which 270 // does not get resource marked or reset during the compile process 271 void *operator new( size_t x, Compile* C ) throw() { return C->comp_arena()->Amalloc(x); } 272 void operator delete( void * ) { } // fast deallocation 273 274 static WarmCallInfo* always_hot(); 275 static WarmCallInfo* always_cold(); 276 277 WarmCallInfo() { 278 _call = NULL; 279 _hot_cg = NULL; 280 _next = NULL; 281 _count = _profit = _work = _size = _heat = 0; 282 } 283 284 CallNode* call() const { return _call; } 285 float count() const { return _count; } 286 float size() const { return _size; } 287 float work() const { return _work; } 288 float profit() const { return _profit; } 289 float heat() const { return _heat; } 290 291 void set_count(float x) { _count = x; } 292 void set_size(float x) { _size = x; } 293 void set_work(float x) { _work = x; } 294 void set_profit(float x) { _profit = x; } 295 void set_heat(float x) { _heat = x; } 296 297 // Load initial heuristics from profiles, etc. 298 // The heuristics can be tweaked further by the caller. 299 void init(JVMState* call_site, ciMethod* call_method, ciCallProfile& profile, float prof_factor); 300 301 static float MAX_VALUE() { return +1.0e10; } 302 static float MIN_VALUE() { return -1.0e10; } 303 304 float compute_heat() const; 305 306 void set_call(CallNode* call) { _call = call; } 307 void set_hot_cg(CallGenerator* cg) { _hot_cg = cg; } 308 309 // Do not queue very hot or very cold calls. 310 // Make very cold ones out of line immediately. 311 // Inline very hot ones immediately. 312 // These queries apply various tunable limits 313 // to the above metrics in a systematic way. 314 // Test for coldness before testing for hotness. 315 bool is_cold() const; 316 bool is_hot() const; 317 318 // Force a warm call to be hot. This worklists the call node for inlining. 319 void make_hot(); 320 321 // Force a warm call to be cold. This worklists the call node for out-of-lining. 322 void make_cold(); 323 324 // A reproducible total ordering, in which heat is the major key. 325 bool warmer_than(WarmCallInfo* that); 326 327 // List management. These methods are called with the list head, 328 // and return the new list head, inserting or removing the receiver. 329 WarmCallInfo* insert_into(WarmCallInfo* head); 330 WarmCallInfo* remove_from(WarmCallInfo* head); 331 332#ifndef PRODUCT 333 void print() const; 334 void print_all() const; 335 int count_all() const; 336#endif 337}; 338 339#endif // SHARE_VM_OPTO_CALLGENERATOR_HPP 340