1 /* 2 * Copyright 2001-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 #include "incls/_precompiled.incl" 26 #include "incls/_graphKit.cpp.incl" 27 28 //----------------------------GraphKit----------------------------------------- 29 // Main utility constructor. 30 GraphKit::GraphKit(JVMState* jvms) 31 : Phase(Phase::Parser), 32 _env(C->env()), 33 _gvn(*C->initial_gvn()) 34 { 35 _exceptions = jvms->map()->next_exception(); 36 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL); 37 set_jvms(jvms); 38 } 39 40 // Private constructor for parser. 41 GraphKit::GraphKit() 42 : Phase(Phase::Parser), 43 _env(C->env()), 44 _gvn(*C->initial_gvn()) 45 { 46 _exceptions = NULL; 47 set_map(NULL); 48 debug_only(_sp = -99); 49 debug_only(set_bci(-99)); 50 } 51 52 53 54 //---------------------------clean_stack--------------------------------------- 55 // Clear away rubbish from the stack area of the JVM state. 56 // This destroys any arguments that may be waiting on the stack. 57 void GraphKit::clean_stack(int from_sp) { 58 SafePointNode* map = this->map(); 59 JVMState* jvms = this->jvms(); 60 int stk_size = jvms->stk_size(); 61 int stkoff = jvms->stkoff(); 62 Node* top = this->top(); 63 for (int i = from_sp; i < stk_size; i++) { 64 if (map->in(stkoff + i) != top) { 65 map->set_req(stkoff + i, top); 66 } 67 } 68 } 69 70 71 //--------------------------------sync_jvms----------------------------------- 72 // Make sure our current jvms agrees with our parse state. 73 JVMState* GraphKit::sync_jvms() const { 74 JVMState* jvms = this->jvms(); 75 jvms->set_bci(bci()); // Record the new bci in the JVMState 76 jvms->set_sp(sp()); // Record the new sp in the JVMState 77 assert(jvms_in_sync(), "jvms is now in sync"); 78 return jvms; 79 } 80 81 #ifdef ASSERT 82 bool GraphKit::jvms_in_sync() const { 83 Parse* parse = is_Parse(); 84 if (parse == NULL) { 85 if (bci() != jvms()->bci()) return false; 86 if (sp() != (int)jvms()->sp()) return false; 87 return true; 88 } 89 if (jvms()->method() != parse->method()) return false; 90 if (jvms()->bci() != parse->bci()) return false; 91 int jvms_sp = jvms()->sp(); 92 if (jvms_sp != parse->sp()) return false; 93 int jvms_depth = jvms()->depth(); 94 if (jvms_depth != parse->depth()) return false; 95 return true; 96 } 97 98 // Local helper checks for special internal merge points 99 // used to accumulate and merge exception states. 100 // They are marked by the region's in(0) edge being the map itself. 101 // Such merge points must never "escape" into the parser at large, 102 // until they have been handed to gvn.transform. 103 static bool is_hidden_merge(Node* reg) { 104 if (reg == NULL) return false; 105 if (reg->is_Phi()) { 106 reg = reg->in(0); 107 if (reg == NULL) return false; 108 } 109 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root(); 110 } 111 112 void GraphKit::verify_map() const { 113 if (map() == NULL) return; // null map is OK 114 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map"); 115 assert(!map()->has_exceptions(), "call add_exception_states_from 1st"); 116 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map"); 117 } 118 119 void GraphKit::verify_exception_state(SafePointNode* ex_map) { 120 assert(ex_map->next_exception() == NULL, "not already part of a chain"); 121 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop"); 122 } 123 #endif 124 125 //---------------------------stop_and_kill_map--------------------------------- 126 // Set _map to NULL, signalling a stop to further bytecode execution. 127 // First smash the current map's control to a constant, to mark it dead. 128 void GraphKit::stop_and_kill_map() { 129 SafePointNode* dead_map = stop(); 130 if (dead_map != NULL) { 131 dead_map->disconnect_inputs(NULL); // Mark the map as killed. 132 assert(dead_map->is_killed(), "must be so marked"); 133 } 134 } 135 136 137 //--------------------------------stopped-------------------------------------- 138 // Tell if _map is NULL, or control is top. 139 bool GraphKit::stopped() { 140 if (map() == NULL) return true; 141 else if (control() == top()) return true; 142 else return false; 143 } 144 145 146 //-----------------------------has_ex_handler---------------------------------- 147 // Tell if this method or any caller method has exception handlers. 148 bool GraphKit::has_ex_handler() { 149 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) { 150 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) { 151 return true; 152 } 153 } 154 return false; 155 } 156 157 //------------------------------save_ex_oop------------------------------------ 158 // Save an exception without blowing stack contents or other JVM state. 159 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) { 160 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again"); 161 ex_map->add_req(ex_oop); 162 debug_only(verify_exception_state(ex_map)); 163 } 164 165 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) { 166 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there"); 167 Node* ex_oop = ex_map->in(ex_map->req()-1); 168 if (clear_it) ex_map->del_req(ex_map->req()-1); 169 return ex_oop; 170 } 171 172 //-----------------------------saved_ex_oop------------------------------------ 173 // Recover a saved exception from its map. 174 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) { 175 return common_saved_ex_oop(ex_map, false); 176 } 177 178 //--------------------------clear_saved_ex_oop--------------------------------- 179 // Erase a previously saved exception from its map. 180 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) { 181 return common_saved_ex_oop(ex_map, true); 182 } 183 184 #ifdef ASSERT 185 //---------------------------has_saved_ex_oop---------------------------------- 186 // Erase a previously saved exception from its map. 187 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) { 188 return ex_map->req() == ex_map->jvms()->endoff()+1; 189 } 190 #endif 191 192 //-------------------------make_exception_state-------------------------------- 193 // Turn the current JVM state into an exception state, appending the ex_oop. 194 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) { 195 sync_jvms(); 196 SafePointNode* ex_map = stop(); // do not manipulate this map any more 197 set_saved_ex_oop(ex_map, ex_oop); 198 return ex_map; 199 } 200 201 202 //--------------------------add_exception_state-------------------------------- 203 // Add an exception to my list of exceptions. 204 void GraphKit::add_exception_state(SafePointNode* ex_map) { 205 if (ex_map == NULL || ex_map->control() == top()) { 206 return; 207 } 208 #ifdef ASSERT 209 verify_exception_state(ex_map); 210 if (has_exceptions()) { 211 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place"); 212 } 213 #endif 214 215 // If there is already an exception of exactly this type, merge with it. 216 // In particular, null-checks and other low-level exceptions common up here. 217 Node* ex_oop = saved_ex_oop(ex_map); 218 const Type* ex_type = _gvn.type(ex_oop); 219 if (ex_oop == top()) { 220 // No action needed. 221 return; 222 } 223 assert(ex_type->isa_instptr(), "exception must be an instance"); 224 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) { 225 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2)); 226 // We check sp also because call bytecodes can generate exceptions 227 // both before and after arguments are popped! 228 if (ex_type2 == ex_type 229 && e2->_jvms->sp() == ex_map->_jvms->sp()) { 230 combine_exception_states(ex_map, e2); 231 return; 232 } 233 } 234 235 // No pre-existing exception of the same type. Chain it on the list. 236 push_exception_state(ex_map); 237 } 238 239 //-----------------------add_exception_states_from----------------------------- 240 void GraphKit::add_exception_states_from(JVMState* jvms) { 241 SafePointNode* ex_map = jvms->map()->next_exception(); 242 if (ex_map != NULL) { 243 jvms->map()->set_next_exception(NULL); 244 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) { 245 next_map = ex_map->next_exception(); 246 ex_map->set_next_exception(NULL); 247 add_exception_state(ex_map); 248 } 249 } 250 } 251 252 //-----------------------transfer_exceptions_into_jvms------------------------- 253 JVMState* GraphKit::transfer_exceptions_into_jvms() { 254 if (map() == NULL) { 255 // We need a JVMS to carry the exceptions, but the map has gone away. 256 // Create a scratch JVMS, cloned from any of the exception states... 257 if (has_exceptions()) { 258 _map = _exceptions; 259 _map = clone_map(); 260 _map->set_next_exception(NULL); 261 clear_saved_ex_oop(_map); 262 debug_only(verify_map()); 263 } else { 264 // ...or created from scratch 265 JVMState* jvms = new (C) JVMState(_method, NULL); 266 jvms->set_bci(_bci); 267 jvms->set_sp(_sp); 268 jvms->set_map(new (C, TypeFunc::Parms) SafePointNode(TypeFunc::Parms, jvms)); 269 set_jvms(jvms); 270 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top()); 271 set_all_memory(top()); 272 while (map()->req() < jvms->endoff()) map()->add_req(top()); 273 } 274 // (This is a kludge, in case you didn't notice.) 275 set_control(top()); 276 } 277 JVMState* jvms = sync_jvms(); 278 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet"); 279 jvms->map()->set_next_exception(_exceptions); 280 _exceptions = NULL; // done with this set of exceptions 281 return jvms; 282 } 283 284 static inline void add_n_reqs(Node* dstphi, Node* srcphi) { 285 assert(is_hidden_merge(dstphi), "must be a special merge node"); 286 assert(is_hidden_merge(srcphi), "must be a special merge node"); 287 uint limit = srcphi->req(); 288 for (uint i = PhiNode::Input; i < limit; i++) { 289 dstphi->add_req(srcphi->in(i)); 290 } 291 } 292 static inline void add_one_req(Node* dstphi, Node* src) { 293 assert(is_hidden_merge(dstphi), "must be a special merge node"); 294 assert(!is_hidden_merge(src), "must not be a special merge node"); 295 dstphi->add_req(src); 296 } 297 298 //-----------------------combine_exception_states------------------------------ 299 // This helper function combines exception states by building phis on a 300 // specially marked state-merging region. These regions and phis are 301 // untransformed, and can build up gradually. The region is marked by 302 // having a control input of its exception map, rather than NULL. Such 303 // regions do not appear except in this function, and in use_exception_state. 304 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) { 305 if (failing()) return; // dying anyway... 306 JVMState* ex_jvms = ex_map->_jvms; 307 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains"); 308 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals"); 309 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes"); 310 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS"); 311 assert(ex_map->req() == phi_map->req(), "matching maps"); 312 uint tos = ex_jvms->stkoff() + ex_jvms->sp(); 313 Node* hidden_merge_mark = root(); 314 Node* region = phi_map->control(); 315 MergeMemNode* phi_mem = phi_map->merged_memory(); 316 MergeMemNode* ex_mem = ex_map->merged_memory(); 317 if (region->in(0) != hidden_merge_mark) { 318 // The control input is not (yet) a specially-marked region in phi_map. 319 // Make it so, and build some phis. 320 region = new (C, 2) RegionNode(2); 321 _gvn.set_type(region, Type::CONTROL); 322 region->set_req(0, hidden_merge_mark); // marks an internal ex-state 323 region->init_req(1, phi_map->control()); 324 phi_map->set_control(region); 325 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO); 326 record_for_igvn(io_phi); 327 _gvn.set_type(io_phi, Type::ABIO); 328 phi_map->set_i_o(io_phi); 329 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) { 330 Node* m = mms.memory(); 331 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C)); 332 record_for_igvn(m_phi); 333 _gvn.set_type(m_phi, Type::MEMORY); 334 mms.set_memory(m_phi); 335 } 336 } 337 338 // Either or both of phi_map and ex_map might already be converted into phis. 339 Node* ex_control = ex_map->control(); 340 // if there is special marking on ex_map also, we add multiple edges from src 341 bool add_multiple = (ex_control->in(0) == hidden_merge_mark); 342 // how wide was the destination phi_map, originally? 343 uint orig_width = region->req(); 344 345 if (add_multiple) { 346 add_n_reqs(region, ex_control); 347 add_n_reqs(phi_map->i_o(), ex_map->i_o()); 348 } else { 349 // ex_map has no merges, so we just add single edges everywhere 350 add_one_req(region, ex_control); 351 add_one_req(phi_map->i_o(), ex_map->i_o()); 352 } 353 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) { 354 if (mms.is_empty()) { 355 // get a copy of the base memory, and patch some inputs into it 356 const TypePtr* adr_type = mms.adr_type(C); 357 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type); 358 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), ""); 359 mms.set_memory(phi); 360 // Prepare to append interesting stuff onto the newly sliced phi: 361 while (phi->req() > orig_width) phi->del_req(phi->req()-1); 362 } 363 // Append stuff from ex_map: 364 if (add_multiple) { 365 add_n_reqs(mms.memory(), mms.memory2()); 366 } else { 367 add_one_req(mms.memory(), mms.memory2()); 368 } 369 } 370 uint limit = ex_map->req(); 371 for (uint i = TypeFunc::Parms; i < limit; i++) { 372 // Skip everything in the JVMS after tos. (The ex_oop follows.) 373 if (i == tos) i = ex_jvms->monoff(); 374 Node* src = ex_map->in(i); 375 Node* dst = phi_map->in(i); 376 if (src != dst) { 377 PhiNode* phi; 378 if (dst->in(0) != region) { 379 dst = phi = PhiNode::make(region, dst, _gvn.type(dst)); 380 record_for_igvn(phi); 381 _gvn.set_type(phi, phi->type()); 382 phi_map->set_req(i, dst); 383 // Prepare to append interesting stuff onto the new phi: 384 while (dst->req() > orig_width) dst->del_req(dst->req()-1); 385 } else { 386 assert(dst->is_Phi(), "nobody else uses a hidden region"); 387 phi = (PhiNode*)dst; 388 } 389 if (add_multiple && src->in(0) == ex_control) { 390 // Both are phis. 391 add_n_reqs(dst, src); 392 } else { 393 while (dst->req() < region->req()) add_one_req(dst, src); 394 } 395 const Type* srctype = _gvn.type(src); 396 if (phi->type() != srctype) { 397 const Type* dsttype = phi->type()->meet(srctype); 398 if (phi->type() != dsttype) { 399 phi->set_type(dsttype); 400 _gvn.set_type(phi, dsttype); 401 } 402 } 403 } 404 } 405 } 406 407 //--------------------------use_exception_state-------------------------------- 408 Node* GraphKit::use_exception_state(SafePointNode* phi_map) { 409 if (failing()) { stop(); return top(); } 410 Node* region = phi_map->control(); 411 Node* hidden_merge_mark = root(); 412 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation"); 413 Node* ex_oop = clear_saved_ex_oop(phi_map); 414 if (region->in(0) == hidden_merge_mark) { 415 // Special marking for internal ex-states. Process the phis now. 416 region->set_req(0, region); // now it's an ordinary region 417 set_jvms(phi_map->jvms()); // ...so now we can use it as a map 418 // Note: Setting the jvms also sets the bci and sp. 419 set_control(_gvn.transform(region)); 420 uint tos = jvms()->stkoff() + sp(); 421 for (uint i = 1; i < tos; i++) { 422 Node* x = phi_map->in(i); 423 if (x->in(0) == region) { 424 assert(x->is_Phi(), "expected a special phi"); 425 phi_map->set_req(i, _gvn.transform(x)); 426 } 427 } 428 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) { 429 Node* x = mms.memory(); 430 if (x->in(0) == region) { 431 assert(x->is_Phi(), "nobody else uses a hidden region"); 432 mms.set_memory(_gvn.transform(x)); 433 } 434 } 435 if (ex_oop->in(0) == region) { 436 assert(ex_oop->is_Phi(), "expected a special phi"); 437 ex_oop = _gvn.transform(ex_oop); 438 } 439 } else { 440 set_jvms(phi_map->jvms()); 441 } 442 443 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared"); 444 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared"); 445 return ex_oop; 446 } 447 448 //---------------------------------java_bc------------------------------------- 449 Bytecodes::Code GraphKit::java_bc() const { 450 ciMethod* method = this->method(); 451 int bci = this->bci(); 452 if (method != NULL && bci != InvocationEntryBci) 453 return method->java_code_at_bci(bci); 454 else 455 return Bytecodes::_illegal; 456 } 457 458 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason, 459 bool must_throw) { 460 // if the exception capability is set, then we will generate code 461 // to check the JavaThread.should_post_on_exceptions flag to see 462 // if we actually need to report exception events (for this 463 // thread). If we don't need to report exception events, we will 464 // take the normal fast path provided by add_exception_events. If 465 // exception event reporting is enabled for this thread, we will 466 // take the uncommon_trap in the BuildCutout below. 467 468 // first must access the should_post_on_exceptions_flag in this thread's JavaThread 469 Node* jthread = _gvn.transform(new (C, 1) ThreadLocalNode()); 470 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset())); 471 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, false); 472 473 // Test the should_post_on_exceptions_flag vs. 0 474 Node* chk = _gvn.transform( new (C, 3) CmpINode(should_post_flag, intcon(0)) ); 475 Node* tst = _gvn.transform( new (C, 2) BoolNode(chk, BoolTest::eq) ); 476 477 // Branch to slow_path if should_post_on_exceptions_flag was true 478 { BuildCutout unless(this, tst, PROB_MAX); 479 // Do not try anything fancy if we're notifying the VM on every throw. 480 // Cf. case Bytecodes::_athrow in parse2.cpp. 481 uncommon_trap(reason, Deoptimization::Action_none, 482 (ciKlass*)NULL, (char*)NULL, must_throw); 483 } 484 485 } 486 487 //------------------------------builtin_throw---------------------------------- 488 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) { 489 bool must_throw = true; 490 491 if (env()->jvmti_can_post_exceptions()) { 492 // check if we must post exception events, take uncommon trap if so 493 uncommon_trap_if_should_post_on_exceptions(reason, must_throw); 494 // here if should_post_on_exceptions is false 495 // continue on with the normal codegen 496 } 497 498 // If this particular condition has not yet happened at this 499 // bytecode, then use the uncommon trap mechanism, and allow for 500 // a future recompilation if several traps occur here. 501 // If the throw is hot, try to use a more complicated inline mechanism 502 // which keeps execution inside the compiled code. 503 bool treat_throw_as_hot = false; 504 ciMethodData* md = method()->method_data(); 505 506 if (ProfileTraps) { 507 if (too_many_traps(reason)) { 508 treat_throw_as_hot = true; 509 } 510 // (If there is no MDO at all, assume it is early in 511 // execution, and that any deopts are part of the 512 // startup transient, and don't need to be remembered.) 513 514 // Also, if there is a local exception handler, treat all throws 515 // as hot if there has been at least one in this method. 516 if (C->trap_count(reason) != 0 517 && method()->method_data()->trap_count(reason) != 0 518 && has_ex_handler()) { 519 treat_throw_as_hot = true; 520 } 521 } 522 523 // If this throw happens frequently, an uncommon trap might cause 524 // a performance pothole. If there is a local exception handler, 525 // and if this particular bytecode appears to be deoptimizing often, 526 // let us handle the throw inline, with a preconstructed instance. 527 // Note: If the deopt count has blown up, the uncommon trap 528 // runtime is going to flush this nmethod, not matter what. 529 if (treat_throw_as_hot 530 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) { 531 // If the throw is local, we use a pre-existing instance and 532 // punt on the backtrace. This would lead to a missing backtrace 533 // (a repeat of 4292742) if the backtrace object is ever asked 534 // for its backtrace. 535 // Fixing this remaining case of 4292742 requires some flavor of 536 // escape analysis. Leave that for the future. 537 ciInstance* ex_obj = NULL; 538 switch (reason) { 539 case Deoptimization::Reason_null_check: 540 ex_obj = env()->NullPointerException_instance(); 541 break; 542 case Deoptimization::Reason_div0_check: 543 ex_obj = env()->ArithmeticException_instance(); 544 break; 545 case Deoptimization::Reason_range_check: 546 ex_obj = env()->ArrayIndexOutOfBoundsException_instance(); 547 break; 548 case Deoptimization::Reason_class_check: 549 if (java_bc() == Bytecodes::_aastore) { 550 ex_obj = env()->ArrayStoreException_instance(); 551 } else { 552 ex_obj = env()->ClassCastException_instance(); 553 } 554 break; 555 } 556 if (failing()) { stop(); return; } // exception allocation might fail 557 if (ex_obj != NULL) { 558 // Cheat with a preallocated exception object. 559 if (C->log() != NULL) 560 C->log()->elem("hot_throw preallocated='1' reason='%s'", 561 Deoptimization::trap_reason_name(reason)); 562 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj); 563 Node* ex_node = _gvn.transform( ConNode::make(C, ex_con) ); 564 565 // Clear the detail message of the preallocated exception object. 566 // Weblogic sometimes mutates the detail message of exceptions 567 // using reflection. 568 int offset = java_lang_Throwable::get_detailMessage_offset(); 569 const TypePtr* adr_typ = ex_con->add_offset(offset); 570 571 Node *adr = basic_plus_adr(ex_node, ex_node, offset); 572 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), ex_con, T_OBJECT); 573 574 add_exception_state(make_exception_state(ex_node)); 575 return; 576 } 577 } 578 579 // %%% Maybe add entry to OptoRuntime which directly throws the exc.? 580 // It won't be much cheaper than bailing to the interp., since we'll 581 // have to pass up all the debug-info, and the runtime will have to 582 // create the stack trace. 583 584 // Usual case: Bail to interpreter. 585 // Reserve the right to recompile if we haven't seen anything yet. 586 587 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile; 588 if (treat_throw_as_hot 589 && (method()->method_data()->trap_recompiled_at(bci()) 590 || C->too_many_traps(reason))) { 591 // We cannot afford to take more traps here. Suffer in the interpreter. 592 if (C->log() != NULL) 593 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'", 594 Deoptimization::trap_reason_name(reason), 595 C->trap_count(reason)); 596 action = Deoptimization::Action_none; 597 } 598 599 // "must_throw" prunes the JVM state to include only the stack, if there 600 // are no local exception handlers. This should cut down on register 601 // allocation time and code size, by drastically reducing the number 602 // of in-edges on the call to the uncommon trap. 603 604 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw); 605 } 606 607 608 //----------------------------PreserveJVMState--------------------------------- 609 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) { 610 debug_only(kit->verify_map()); 611 _kit = kit; 612 _map = kit->map(); // preserve the map 613 _sp = kit->sp(); 614 kit->set_map(clone_map ? kit->clone_map() : NULL); 615 #ifdef ASSERT 616 _bci = kit->bci(); 617 Parse* parser = kit->is_Parse(); 618 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo(); 619 _block = block; 620 #endif 621 } 622 PreserveJVMState::~PreserveJVMState() { 623 GraphKit* kit = _kit; 624 #ifdef ASSERT 625 assert(kit->bci() == _bci, "bci must not shift"); 626 Parse* parser = kit->is_Parse(); 627 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo(); 628 assert(block == _block, "block must not shift"); 629 #endif 630 kit->set_map(_map); 631 kit->set_sp(_sp); 632 } 633 634 635 //-----------------------------BuildCutout------------------------------------- 636 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt) 637 : PreserveJVMState(kit) 638 { 639 assert(p->is_Con() || p->is_Bool(), "test must be a bool"); 640 SafePointNode* outer_map = _map; // preserved map is caller's 641 SafePointNode* inner_map = kit->map(); 642 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt); 643 outer_map->set_control(kit->gvn().transform( new (kit->C, 1) IfTrueNode(iff) )); 644 inner_map->set_control(kit->gvn().transform( new (kit->C, 1) IfFalseNode(iff) )); 645 } 646 BuildCutout::~BuildCutout() { 647 GraphKit* kit = _kit; 648 assert(kit->stopped(), "cutout code must stop, throw, return, etc."); 649 } 650 651 //---------------------------PreserveReexecuteState---------------------------- 652 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) { 653 assert(!kit->stopped(), "must call stopped() before"); 654 _kit = kit; 655 _sp = kit->sp(); 656 _reexecute = kit->jvms()->_reexecute; 657 } 658 PreserveReexecuteState::~PreserveReexecuteState() { 659 if (_kit->stopped()) return; 660 _kit->jvms()->_reexecute = _reexecute; 661 _kit->set_sp(_sp); 662 } 663 664 //------------------------------clone_map-------------------------------------- 665 // Implementation of PreserveJVMState 666 // 667 // Only clone_map(...) here. If this function is only used in the 668 // PreserveJVMState class we may want to get rid of this extra 669 // function eventually and do it all there. 670 671 SafePointNode* GraphKit::clone_map() { 672 if (map() == NULL) return NULL; 673 674 // Clone the memory edge first 675 Node* mem = MergeMemNode::make(C, map()->memory()); 676 gvn().set_type_bottom(mem); 677 678 SafePointNode *clonemap = (SafePointNode*)map()->clone(); 679 JVMState* jvms = this->jvms(); 680 JVMState* clonejvms = jvms->clone_shallow(C); 681 clonemap->set_memory(mem); 682 clonemap->set_jvms(clonejvms); 683 clonejvms->set_map(clonemap); 684 record_for_igvn(clonemap); 685 gvn().set_type_bottom(clonemap); 686 return clonemap; 687 } 688 689 690 //-----------------------------set_map_clone----------------------------------- 691 void GraphKit::set_map_clone(SafePointNode* m) { 692 _map = m; 693 _map = clone_map(); 694 _map->set_next_exception(NULL); 695 debug_only(verify_map()); 696 } 697 698 699 //----------------------------kill_dead_locals--------------------------------- 700 // Detect any locals which are known to be dead, and force them to top. 701 void GraphKit::kill_dead_locals() { 702 // Consult the liveness information for the locals. If any 703 // of them are unused, then they can be replaced by top(). This 704 // should help register allocation time and cut down on the size 705 // of the deoptimization information. 706 707 // This call is made from many of the bytecode handling 708 // subroutines called from the Big Switch in do_one_bytecode. 709 // Every bytecode which might include a slow path is responsible 710 // for killing its dead locals. The more consistent we 711 // are about killing deads, the fewer useless phis will be 712 // constructed for them at various merge points. 713 714 // bci can be -1 (InvocationEntryBci). We return the entry 715 // liveness for the method. 716 717 if (method() == NULL || method()->code_size() == 0) { 718 // We are building a graph for a call to a native method. 719 // All locals are live. 720 return; 721 } 722 723 ResourceMark rm; 724 725 // Consult the liveness information for the locals. If any 726 // of them are unused, then they can be replaced by top(). This 727 // should help register allocation time and cut down on the size 728 // of the deoptimization information. 729 MethodLivenessResult live_locals = method()->liveness_at_bci(bci()); 730 731 int len = (int)live_locals.size(); 732 assert(len <= jvms()->loc_size(), "too many live locals"); 733 for (int local = 0; local < len; local++) { 734 if (!live_locals.at(local)) { 735 set_local(local, top()); 736 } 737 } 738 } 739 740 #ifdef ASSERT 741 //-------------------------dead_locals_are_killed------------------------------ 742 // Return true if all dead locals are set to top in the map. 743 // Used to assert "clean" debug info at various points. 744 bool GraphKit::dead_locals_are_killed() { 745 if (method() == NULL || method()->code_size() == 0) { 746 // No locals need to be dead, so all is as it should be. 747 return true; 748 } 749 750 // Make sure somebody called kill_dead_locals upstream. 751 ResourceMark rm; 752 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) { 753 if (jvms->loc_size() == 0) continue; // no locals to consult 754 SafePointNode* map = jvms->map(); 755 ciMethod* method = jvms->method(); 756 int bci = jvms->bci(); 757 if (jvms == this->jvms()) { 758 bci = this->bci(); // it might not yet be synched 759 } 760 MethodLivenessResult live_locals = method->liveness_at_bci(bci); 761 int len = (int)live_locals.size(); 762 if (!live_locals.is_valid() || len == 0) 763 // This method is trivial, or is poisoned by a breakpoint. 764 return true; 765 assert(len == jvms->loc_size(), "live map consistent with locals map"); 766 for (int local = 0; local < len; local++) { 767 if (!live_locals.at(local) && map->local(jvms, local) != top()) { 768 if (PrintMiscellaneous && (Verbose || WizardMode)) { 769 tty->print_cr("Zombie local %d: ", local); 770 jvms->dump(); 771 } 772 return false; 773 } 774 } 775 } 776 return true; 777 } 778 779 #endif //ASSERT 780 781 // Helper function for enforcing certain bytecodes to reexecute if 782 // deoptimization happens 783 static bool should_reexecute_implied_by_bytecode(JVMState *jvms) { 784 ciMethod* cur_method = jvms->method(); 785 int cur_bci = jvms->bci(); 786 if (cur_method != NULL && cur_bci != InvocationEntryBci) { 787 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci); 788 return Interpreter::bytecode_should_reexecute(code); 789 } else 790 return false; 791 } 792 793 // Helper function for adding JVMState and debug information to node 794 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) { 795 // Add the safepoint edges to the call (or other safepoint). 796 797 // Make sure dead locals are set to top. This 798 // should help register allocation time and cut down on the size 799 // of the deoptimization information. 800 assert(dead_locals_are_killed(), "garbage in debug info before safepoint"); 801 802 // Walk the inline list to fill in the correct set of JVMState's 803 // Also fill in the associated edges for each JVMState. 804 805 JVMState* youngest_jvms = sync_jvms(); 806 807 // Do we need debug info here? If it is a SafePoint and this method 808 // cannot de-opt, then we do NOT need any debug info. 809 bool full_info = (C->deopt_happens() || call->Opcode() != Op_SafePoint); 810 811 // If we are guaranteed to throw, we can prune everything but the 812 // input to the current bytecode. 813 bool can_prune_locals = false; 814 uint stack_slots_not_pruned = 0; 815 int inputs = 0, depth = 0; 816 if (must_throw) { 817 assert(method() == youngest_jvms->method(), "sanity"); 818 if (compute_stack_effects(inputs, depth)) { 819 can_prune_locals = true; 820 stack_slots_not_pruned = inputs; 821 } 822 } 823 824 if (env()->jvmti_can_examine_or_deopt_anywhere()) { 825 // At any safepoint, this method can get breakpointed, which would 826 // then require an immediate deoptimization. 827 full_info = true; 828 can_prune_locals = false; // do not prune locals 829 stack_slots_not_pruned = 0; 830 } 831 832 // do not scribble on the input jvms 833 JVMState* out_jvms = youngest_jvms->clone_deep(C); 834 call->set_jvms(out_jvms); // Start jvms list for call node 835 836 // For a known set of bytecodes, the interpreter should reexecute them if 837 // deoptimization happens. We set the reexecute state for them here 838 if (out_jvms->is_reexecute_undefined() && //don't change if already specified 839 should_reexecute_implied_by_bytecode(out_jvms)) { 840 out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed 841 } 842 843 // Presize the call: 844 debug_only(uint non_debug_edges = call->req()); 845 call->add_req_batch(top(), youngest_jvms->debug_depth()); 846 assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), ""); 847 848 // Set up edges so that the call looks like this: 849 // Call [state:] ctl io mem fptr retadr 850 // [parms:] parm0 ... parmN 851 // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN 852 // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...] 853 // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN 854 // Note that caller debug info precedes callee debug info. 855 856 // Fill pointer walks backwards from "young:" to "root:" in the diagram above: 857 uint debug_ptr = call->req(); 858 859 // Loop over the map input edges associated with jvms, add them 860 // to the call node, & reset all offsets to match call node array. 861 for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) { 862 uint debug_end = debug_ptr; 863 uint debug_start = debug_ptr - in_jvms->debug_size(); 864 debug_ptr = debug_start; // back up the ptr 865 866 uint p = debug_start; // walks forward in [debug_start, debug_end) 867 uint j, k, l; 868 SafePointNode* in_map = in_jvms->map(); 869 out_jvms->set_map(call); 870 871 if (can_prune_locals) { 872 assert(in_jvms->method() == out_jvms->method(), "sanity"); 873 // If the current throw can reach an exception handler in this JVMS, 874 // then we must keep everything live that can reach that handler. 875 // As a quick and dirty approximation, we look for any handlers at all. 876 if (in_jvms->method()->has_exception_handlers()) { 877 can_prune_locals = false; 878 } 879 } 880 881 // Add the Locals 882 k = in_jvms->locoff(); 883 l = in_jvms->loc_size(); 884 out_jvms->set_locoff(p); 885 if (full_info && !can_prune_locals) { 886 for (j = 0; j < l; j++) 887 call->set_req(p++, in_map->in(k+j)); 888 } else { 889 p += l; // already set to top above by add_req_batch 890 } 891 892 // Add the Expression Stack 893 k = in_jvms->stkoff(); 894 l = in_jvms->sp(); 895 out_jvms->set_stkoff(p); 896 if (full_info && !can_prune_locals) { 897 for (j = 0; j < l; j++) 898 call->set_req(p++, in_map->in(k+j)); 899 } else if (can_prune_locals && stack_slots_not_pruned != 0) { 900 // Divide stack into {S0,...,S1}, where S0 is set to top. 901 uint s1 = stack_slots_not_pruned; 902 stack_slots_not_pruned = 0; // for next iteration 903 if (s1 > l) s1 = l; 904 uint s0 = l - s1; 905 p += s0; // skip the tops preinstalled by add_req_batch 906 for (j = s0; j < l; j++) 907 call->set_req(p++, in_map->in(k+j)); 908 } else { 909 p += l; // already set to top above by add_req_batch 910 } 911 912 // Add the Monitors 913 k = in_jvms->monoff(); 914 l = in_jvms->mon_size(); 915 out_jvms->set_monoff(p); 916 for (j = 0; j < l; j++) 917 call->set_req(p++, in_map->in(k+j)); 918 919 // Copy any scalar object fields. 920 k = in_jvms->scloff(); 921 l = in_jvms->scl_size(); 922 out_jvms->set_scloff(p); 923 for (j = 0; j < l; j++) 924 call->set_req(p++, in_map->in(k+j)); 925 926 // Finish the new jvms. 927 out_jvms->set_endoff(p); 928 929 assert(out_jvms->endoff() == debug_end, "fill ptr must match"); 930 assert(out_jvms->depth() == in_jvms->depth(), "depth must match"); 931 assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match"); 932 assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match"); 933 assert(out_jvms->scl_size() == in_jvms->scl_size(), "size must match"); 934 assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match"); 935 936 // Update the two tail pointers in parallel. 937 out_jvms = out_jvms->caller(); 938 in_jvms = in_jvms->caller(); 939 } 940 941 assert(debug_ptr == non_debug_edges, "debug info must fit exactly"); 942 943 // Test the correctness of JVMState::debug_xxx accessors: 944 assert(call->jvms()->debug_start() == non_debug_edges, ""); 945 assert(call->jvms()->debug_end() == call->req(), ""); 946 assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, ""); 947 } 948 949 bool GraphKit::compute_stack_effects(int& inputs, int& depth) { 950 Bytecodes::Code code = java_bc(); 951 if (code == Bytecodes::_wide) { 952 code = method()->java_code_at_bci(bci() + 1); 953 } 954 955 BasicType rtype = T_ILLEGAL; 956 int rsize = 0; 957 958 if (code != Bytecodes::_illegal) { 959 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1 960 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V 961 if (rtype < T_CONFLICT) 962 rsize = type2size[rtype]; 963 } 964 965 switch (code) { 966 case Bytecodes::_illegal: 967 return false; 968 969 case Bytecodes::_ldc: 970 case Bytecodes::_ldc_w: 971 case Bytecodes::_ldc2_w: 972 inputs = 0; 973 break; 974 975 case Bytecodes::_dup: inputs = 1; break; 976 case Bytecodes::_dup_x1: inputs = 2; break; 977 case Bytecodes::_dup_x2: inputs = 3; break; 978 case Bytecodes::_dup2: inputs = 2; break; 979 case Bytecodes::_dup2_x1: inputs = 3; break; 980 case Bytecodes::_dup2_x2: inputs = 4; break; 981 case Bytecodes::_swap: inputs = 2; break; 982 case Bytecodes::_arraylength: inputs = 1; break; 983 984 case Bytecodes::_getstatic: 985 case Bytecodes::_putstatic: 986 case Bytecodes::_getfield: 987 case Bytecodes::_putfield: 988 { 989 bool is_get = (depth >= 0), is_static = (depth & 1); 990 bool ignore; 991 ciBytecodeStream iter(method()); 992 iter.reset_to_bci(bci()); 993 iter.next(); 994 ciField* field = iter.get_field(ignore); 995 int size = field->type()->size(); 996 inputs = (is_static ? 0 : 1); 997 if (is_get) { 998 depth = size - inputs; 999 } else { 1000 inputs += size; // putxxx pops the value from the stack 1001 depth = - inputs; 1002 } 1003 } 1004 break; 1005 1006 case Bytecodes::_invokevirtual: 1007 case Bytecodes::_invokespecial: 1008 case Bytecodes::_invokestatic: 1009 case Bytecodes::_invokedynamic: 1010 case Bytecodes::_invokeinterface: 1011 { 1012 bool is_static = (depth == 0); 1013 bool ignore; 1014 ciBytecodeStream iter(method()); 1015 iter.reset_to_bci(bci()); 1016 iter.next(); 1017 ciMethod* method = iter.get_method(ignore); 1018 inputs = method->arg_size_no_receiver(); 1019 if (!is_static) inputs += 1; 1020 int size = method->return_type()->size(); 1021 depth = size - inputs; 1022 } 1023 break; 1024 1025 case Bytecodes::_multianewarray: 1026 { 1027 ciBytecodeStream iter(method()); 1028 iter.reset_to_bci(bci()); 1029 iter.next(); 1030 inputs = iter.get_dimensions(); 1031 assert(rsize == 1, ""); 1032 depth = rsize - inputs; 1033 } 1034 break; 1035 1036 case Bytecodes::_ireturn: 1037 case Bytecodes::_lreturn: 1038 case Bytecodes::_freturn: 1039 case Bytecodes::_dreturn: 1040 case Bytecodes::_areturn: 1041 assert(rsize = -depth, ""); 1042 inputs = rsize; 1043 break; 1044 1045 case Bytecodes::_jsr: 1046 case Bytecodes::_jsr_w: 1047 inputs = 0; 1048 depth = 1; // S.B. depth=1, not zero 1049 break; 1050 1051 default: 1052 // bytecode produces a typed result 1053 inputs = rsize - depth; 1054 assert(inputs >= 0, ""); 1055 break; 1056 } 1057 1058 #ifdef ASSERT 1059 // spot check 1060 int outputs = depth + inputs; 1061 assert(outputs >= 0, "sanity"); 1062 switch (code) { 1063 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break; 1064 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break; 1065 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break; 1066 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break; 1067 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break; 1068 } 1069 #endif //ASSERT 1070 1071 return true; 1072 } 1073 1074 1075 1076 //------------------------------basic_plus_adr--------------------------------- 1077 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) { 1078 // short-circuit a common case 1079 if (offset == intcon(0)) return ptr; 1080 return _gvn.transform( new (C, 4) AddPNode(base, ptr, offset) ); 1081 } 1082 1083 Node* GraphKit::ConvI2L(Node* offset) { 1084 // short-circuit a common case 1085 jint offset_con = find_int_con(offset, Type::OffsetBot); 1086 if (offset_con != Type::OffsetBot) { 1087 return longcon((long) offset_con); 1088 } 1089 return _gvn.transform( new (C, 2) ConvI2LNode(offset)); 1090 } 1091 Node* GraphKit::ConvL2I(Node* offset) { 1092 // short-circuit a common case 1093 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot); 1094 if (offset_con != (jlong)Type::OffsetBot) { 1095 return intcon((int) offset_con); 1096 } 1097 return _gvn.transform( new (C, 2) ConvL2INode(offset)); 1098 } 1099 1100 //-------------------------load_object_klass----------------------------------- 1101 Node* GraphKit::load_object_klass(Node* obj) { 1102 // Special-case a fresh allocation to avoid building nodes: 1103 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn); 1104 if (akls != NULL) return akls; 1105 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes()); 1106 return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) ); 1107 } 1108 1109 //-------------------------load_array_length----------------------------------- 1110 Node* GraphKit::load_array_length(Node* array) { 1111 // Special-case a fresh allocation to avoid building nodes: 1112 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn); 1113 Node *alen; 1114 if (alloc == NULL) { 1115 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes()); 1116 alen = _gvn.transform( new (C, 3) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS)); 1117 } else { 1118 alen = alloc->Ideal_length(); 1119 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn); 1120 if (ccast != alen) { 1121 alen = _gvn.transform(ccast); 1122 } 1123 } 1124 return alen; 1125 } 1126 1127 //------------------------------do_null_check---------------------------------- 1128 // Helper function to do a NULL pointer check. Returned value is 1129 // the incoming address with NULL casted away. You are allowed to use the 1130 // not-null value only if you are control dependent on the test. 1131 extern int explicit_null_checks_inserted, 1132 explicit_null_checks_elided; 1133 Node* GraphKit::null_check_common(Node* value, BasicType type, 1134 // optional arguments for variations: 1135 bool assert_null, 1136 Node* *null_control) { 1137 assert(!assert_null || null_control == NULL, "not both at once"); 1138 if (stopped()) return top(); 1139 if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) { 1140 // For some performance testing, we may wish to suppress null checking. 1141 value = cast_not_null(value); // Make it appear to be non-null (4962416). 1142 return value; 1143 } 1144 explicit_null_checks_inserted++; 1145 1146 // Construct NULL check 1147 Node *chk = NULL; 1148 switch(type) { 1149 case T_LONG : chk = new (C, 3) CmpLNode(value, _gvn.zerocon(T_LONG)); break; 1150 case T_INT : chk = new (C, 3) CmpINode( value, _gvn.intcon(0)); break; 1151 case T_ARRAY : // fall through 1152 type = T_OBJECT; // simplify further tests 1153 case T_OBJECT : { 1154 const Type *t = _gvn.type( value ); 1155 1156 const TypeOopPtr* tp = t->isa_oopptr(); 1157 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded() 1158 // Only for do_null_check, not any of its siblings: 1159 && !assert_null && null_control == NULL) { 1160 // Usually, any field access or invocation on an unloaded oop type 1161 // will simply fail to link, since the statically linked class is 1162 // likely also to be unloaded. However, in -Xcomp mode, sometimes 1163 // the static class is loaded but the sharper oop type is not. 1164 // Rather than checking for this obscure case in lots of places, 1165 // we simply observe that a null check on an unloaded class 1166 // will always be followed by a nonsense operation, so we 1167 // can just issue the uncommon trap here. 1168 // Our access to the unloaded class will only be correct 1169 // after it has been loaded and initialized, which requires 1170 // a trip through the interpreter. 1171 #ifndef PRODUCT 1172 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); } 1173 #endif 1174 uncommon_trap(Deoptimization::Reason_unloaded, 1175 Deoptimization::Action_reinterpret, 1176 tp->klass(), "!loaded"); 1177 return top(); 1178 } 1179 1180 if (assert_null) { 1181 // See if the type is contained in NULL_PTR. 1182 // If so, then the value is already null. 1183 if (t->higher_equal(TypePtr::NULL_PTR)) { 1184 explicit_null_checks_elided++; 1185 return value; // Elided null assert quickly! 1186 } 1187 } else { 1188 // See if mixing in the NULL pointer changes type. 1189 // If so, then the NULL pointer was not allowed in the original 1190 // type. In other words, "value" was not-null. 1191 if (t->meet(TypePtr::NULL_PTR) != t) { 1192 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ... 1193 explicit_null_checks_elided++; 1194 return value; // Elided null check quickly! 1195 } 1196 } 1197 chk = new (C, 3) CmpPNode( value, null() ); 1198 break; 1199 } 1200 1201 default : ShouldNotReachHere(); 1202 } 1203 assert(chk != NULL, "sanity check"); 1204 chk = _gvn.transform(chk); 1205 1206 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne; 1207 BoolNode *btst = new (C, 2) BoolNode( chk, btest); 1208 Node *tst = _gvn.transform( btst ); 1209 1210 //----------- 1211 // if peephole optimizations occurred, a prior test existed. 1212 // If a prior test existed, maybe it dominates as we can avoid this test. 1213 if (tst != btst && type == T_OBJECT) { 1214 // At this point we want to scan up the CFG to see if we can 1215 // find an identical test (and so avoid this test altogether). 1216 Node *cfg = control(); 1217 int depth = 0; 1218 while( depth < 16 ) { // Limit search depth for speed 1219 if( cfg->Opcode() == Op_IfTrue && 1220 cfg->in(0)->in(1) == tst ) { 1221 // Found prior test. Use "cast_not_null" to construct an identical 1222 // CastPP (and hence hash to) as already exists for the prior test. 1223 // Return that casted value. 1224 if (assert_null) { 1225 replace_in_map(value, null()); 1226 return null(); // do not issue the redundant test 1227 } 1228 Node *oldcontrol = control(); 1229 set_control(cfg); 1230 Node *res = cast_not_null(value); 1231 set_control(oldcontrol); 1232 explicit_null_checks_elided++; 1233 return res; 1234 } 1235 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true); 1236 if (cfg == NULL) break; // Quit at region nodes 1237 depth++; 1238 } 1239 } 1240 1241 //----------- 1242 // Branch to failure if null 1243 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen 1244 Deoptimization::DeoptReason reason; 1245 if (assert_null) 1246 reason = Deoptimization::Reason_null_assert; 1247 else if (type == T_OBJECT) 1248 reason = Deoptimization::Reason_null_check; 1249 else 1250 reason = Deoptimization::Reason_div0_check; 1251 1252 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis, 1253 // ciMethodData::has_trap_at will return a conservative -1 if any 1254 // must-be-null assertion has failed. This could cause performance 1255 // problems for a method after its first do_null_assert failure. 1256 // Consider using 'Reason_class_check' instead? 1257 1258 // To cause an implicit null check, we set the not-null probability 1259 // to the maximum (PROB_MAX). For an explicit check the probability 1260 // is set to a smaller value. 1261 if (null_control != NULL || too_many_traps(reason)) { 1262 // probability is less likely 1263 ok_prob = PROB_LIKELY_MAG(3); 1264 } else if (!assert_null && 1265 (ImplicitNullCheckThreshold > 0) && 1266 method() != NULL && 1267 (method()->method_data()->trap_count(reason) 1268 >= (uint)ImplicitNullCheckThreshold)) { 1269 ok_prob = PROB_LIKELY_MAG(3); 1270 } 1271 1272 if (null_control != NULL) { 1273 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN); 1274 Node* null_true = _gvn.transform( new (C, 1) IfFalseNode(iff)); 1275 set_control( _gvn.transform( new (C, 1) IfTrueNode(iff))); 1276 if (null_true == top()) 1277 explicit_null_checks_elided++; 1278 (*null_control) = null_true; 1279 } else { 1280 BuildCutout unless(this, tst, ok_prob); 1281 // Check for optimizer eliding test at parse time 1282 if (stopped()) { 1283 // Failure not possible; do not bother making uncommon trap. 1284 explicit_null_checks_elided++; 1285 } else if (assert_null) { 1286 uncommon_trap(reason, 1287 Deoptimization::Action_make_not_entrant, 1288 NULL, "assert_null"); 1289 } else { 1290 replace_in_map(value, zerocon(type)); 1291 builtin_throw(reason); 1292 } 1293 } 1294 1295 // Must throw exception, fall-thru not possible? 1296 if (stopped()) { 1297 return top(); // No result 1298 } 1299 1300 if (assert_null) { 1301 // Cast obj to null on this path. 1302 replace_in_map(value, zerocon(type)); 1303 return zerocon(type); 1304 } 1305 1306 // Cast obj to not-null on this path, if there is no null_control. 1307 // (If there is a null_control, a non-null value may come back to haunt us.) 1308 if (type == T_OBJECT) { 1309 Node* cast = cast_not_null(value, false); 1310 if (null_control == NULL || (*null_control) == top()) 1311 replace_in_map(value, cast); 1312 value = cast; 1313 } 1314 1315 return value; 1316 } 1317 1318 1319 //------------------------------cast_not_null---------------------------------- 1320 // Cast obj to not-null on this path 1321 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) { 1322 const Type *t = _gvn.type(obj); 1323 const Type *t_not_null = t->join(TypePtr::NOTNULL); 1324 // Object is already not-null? 1325 if( t == t_not_null ) return obj; 1326 1327 Node *cast = new (C, 2) CastPPNode(obj,t_not_null); 1328 cast->init_req(0, control()); 1329 cast = _gvn.transform( cast ); 1330 1331 // Scan for instances of 'obj' in the current JVM mapping. 1332 // These instances are known to be not-null after the test. 1333 if (do_replace_in_map) 1334 replace_in_map(obj, cast); 1335 1336 return cast; // Return casted value 1337 } 1338 1339 1340 //--------------------------replace_in_map------------------------------------- 1341 void GraphKit::replace_in_map(Node* old, Node* neww) { 1342 this->map()->replace_edge(old, neww); 1343 1344 // Note: This operation potentially replaces any edge 1345 // on the map. This includes locals, stack, and monitors 1346 // of the current (innermost) JVM state. 1347 1348 // We can consider replacing in caller maps. 1349 // The idea would be that an inlined function's null checks 1350 // can be shared with the entire inlining tree. 1351 // The expense of doing this is that the PreserveJVMState class 1352 // would have to preserve caller states too, with a deep copy. 1353 } 1354 1355 1356 1357 //============================================================================= 1358 //--------------------------------memory--------------------------------------- 1359 Node* GraphKit::memory(uint alias_idx) { 1360 MergeMemNode* mem = merged_memory(); 1361 Node* p = mem->memory_at(alias_idx); 1362 _gvn.set_type(p, Type::MEMORY); // must be mapped 1363 return p; 1364 } 1365 1366 //-----------------------------reset_memory------------------------------------ 1367 Node* GraphKit::reset_memory() { 1368 Node* mem = map()->memory(); 1369 // do not use this node for any more parsing! 1370 debug_only( map()->set_memory((Node*)NULL) ); 1371 return _gvn.transform( mem ); 1372 } 1373 1374 //------------------------------set_all_memory--------------------------------- 1375 void GraphKit::set_all_memory(Node* newmem) { 1376 Node* mergemem = MergeMemNode::make(C, newmem); 1377 gvn().set_type_bottom(mergemem); 1378 map()->set_memory(mergemem); 1379 } 1380 1381 //------------------------------set_all_memory_call---------------------------- 1382 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) { 1383 Node* newmem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory, separate_io_proj) ); 1384 set_all_memory(newmem); 1385 } 1386 1387 //============================================================================= 1388 // 1389 // parser factory methods for MemNodes 1390 // 1391 // These are layered on top of the factory methods in LoadNode and StoreNode, 1392 // and integrate with the parser's memory state and _gvn engine. 1393 // 1394 1395 // factory methods in "int adr_idx" 1396 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, 1397 int adr_idx, 1398 bool require_atomic_access) { 1399 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" ); 1400 const TypePtr* adr_type = NULL; // debug-mode-only argument 1401 debug_only(adr_type = C->get_adr_type(adr_idx)); 1402 Node* mem = memory(adr_idx); 1403 Node* ld; 1404 if (require_atomic_access && bt == T_LONG) { 1405 ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t); 1406 } else { 1407 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt); 1408 } 1409 return _gvn.transform(ld); 1410 } 1411 1412 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt, 1413 int adr_idx, 1414 bool require_atomic_access) { 1415 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 1416 const TypePtr* adr_type = NULL; 1417 debug_only(adr_type = C->get_adr_type(adr_idx)); 1418 Node *mem = memory(adr_idx); 1419 Node* st; 1420 if (require_atomic_access && bt == T_LONG) { 1421 st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val); 1422 } else { 1423 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt); 1424 } 1425 st = _gvn.transform(st); 1426 set_memory(st, adr_idx); 1427 // Back-to-back stores can only remove intermediate store with DU info 1428 // so push on worklist for optimizer. 1429 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address)) 1430 record_for_igvn(st); 1431 1432 return st; 1433 } 1434 1435 1436 void GraphKit::pre_barrier(Node* ctl, 1437 Node* obj, 1438 Node* adr, 1439 uint adr_idx, 1440 Node* val, 1441 const TypeOopPtr* val_type, 1442 BasicType bt) { 1443 BarrierSet* bs = Universe::heap()->barrier_set(); 1444 set_control(ctl); 1445 switch (bs->kind()) { 1446 case BarrierSet::G1SATBCT: 1447 case BarrierSet::G1SATBCTLogging: 1448 g1_write_barrier_pre(obj, adr, adr_idx, val, val_type, bt); 1449 break; 1450 1451 case BarrierSet::CardTableModRef: 1452 case BarrierSet::CardTableExtension: 1453 case BarrierSet::ModRef: 1454 break; 1455 1456 case BarrierSet::Other: 1457 default : 1458 ShouldNotReachHere(); 1459 1460 } 1461 } 1462 1463 void GraphKit::post_barrier(Node* ctl, 1464 Node* store, 1465 Node* obj, 1466 Node* adr, 1467 uint adr_idx, 1468 Node* val, 1469 BasicType bt, 1470 bool use_precise) { 1471 BarrierSet* bs = Universe::heap()->barrier_set(); 1472 set_control(ctl); 1473 switch (bs->kind()) { 1474 case BarrierSet::G1SATBCT: 1475 case BarrierSet::G1SATBCTLogging: 1476 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise); 1477 break; 1478 1479 case BarrierSet::CardTableModRef: 1480 case BarrierSet::CardTableExtension: 1481 write_barrier_post(store, obj, adr, adr_idx, val, use_precise); 1482 break; 1483 1484 case BarrierSet::ModRef: 1485 break; 1486 1487 case BarrierSet::Other: 1488 default : 1489 ShouldNotReachHere(); 1490 1491 } 1492 } 1493 1494 Node* GraphKit::store_oop(Node* ctl, 1495 Node* obj, 1496 Node* adr, 1497 const TypePtr* adr_type, 1498 Node* val, 1499 const TypeOopPtr* val_type, 1500 BasicType bt, 1501 bool use_precise) { 1502 1503 set_control(ctl); 1504 if (stopped()) return top(); // Dead path ? 1505 1506 assert(bt == T_OBJECT, "sanity"); 1507 assert(val != NULL, "not dead path"); 1508 uint adr_idx = C->get_alias_index(adr_type); 1509 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 1510 1511 pre_barrier(control(), obj, adr, adr_idx, val, val_type, bt); 1512 Node* store = store_to_memory(control(), adr, val, bt, adr_idx); 1513 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise); 1514 return store; 1515 } 1516 1517 // Could be an array or object we don't know at compile time (unsafe ref.) 1518 Node* GraphKit::store_oop_to_unknown(Node* ctl, 1519 Node* obj, // containing obj 1520 Node* adr, // actual adress to store val at 1521 const TypePtr* adr_type, 1522 Node* val, 1523 BasicType bt) { 1524 Compile::AliasType* at = C->alias_type(adr_type); 1525 const TypeOopPtr* val_type = NULL; 1526 if (adr_type->isa_instptr()) { 1527 if (at->field() != NULL) { 1528 // known field. This code is a copy of the do_put_xxx logic. 1529 ciField* field = at->field(); 1530 if (!field->type()->is_loaded()) { 1531 val_type = TypeInstPtr::BOTTOM; 1532 } else { 1533 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass()); 1534 } 1535 } 1536 } else if (adr_type->isa_aryptr()) { 1537 val_type = adr_type->is_aryptr()->elem()->make_oopptr(); 1538 } 1539 if (val_type == NULL) { 1540 val_type = TypeInstPtr::BOTTOM; 1541 } 1542 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true); 1543 } 1544 1545 1546 //-------------------------array_element_address------------------------- 1547 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt, 1548 const TypeInt* sizetype) { 1549 uint shift = exact_log2(type2aelembytes(elembt)); 1550 uint header = arrayOopDesc::base_offset_in_bytes(elembt); 1551 1552 // short-circuit a common case (saves lots of confusing waste motion) 1553 jint idx_con = find_int_con(idx, -1); 1554 if (idx_con >= 0) { 1555 intptr_t offset = header + ((intptr_t)idx_con << shift); 1556 return basic_plus_adr(ary, offset); 1557 } 1558 1559 // must be correct type for alignment purposes 1560 Node* base = basic_plus_adr(ary, header); 1561 #ifdef _LP64 1562 // The scaled index operand to AddP must be a clean 64-bit value. 1563 // Java allows a 32-bit int to be incremented to a negative 1564 // value, which appears in a 64-bit register as a large 1565 // positive number. Using that large positive number as an 1566 // operand in pointer arithmetic has bad consequences. 1567 // On the other hand, 32-bit overflow is rare, and the possibility 1568 // can often be excluded, if we annotate the ConvI2L node with 1569 // a type assertion that its value is known to be a small positive 1570 // number. (The prior range check has ensured this.) 1571 // This assertion is used by ConvI2LNode::Ideal. 1572 int index_max = max_jint - 1; // array size is max_jint, index is one less 1573 if (sizetype != NULL) index_max = sizetype->_hi - 1; 1574 const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax); 1575 idx = _gvn.transform( new (C, 2) ConvI2LNode(idx, lidxtype) ); 1576 #endif 1577 Node* scale = _gvn.transform( new (C, 3) LShiftXNode(idx, intcon(shift)) ); 1578 return basic_plus_adr(ary, base, scale); 1579 } 1580 1581 //-------------------------load_array_element------------------------- 1582 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) { 1583 const Type* elemtype = arytype->elem(); 1584 BasicType elembt = elemtype->array_element_basic_type(); 1585 Node* adr = array_element_address(ary, idx, elembt, arytype->size()); 1586 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype); 1587 return ld; 1588 } 1589 1590 //-------------------------set_arguments_for_java_call------------------------- 1591 // Arguments (pre-popped from the stack) are taken from the JVMS. 1592 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) { 1593 // Add the call arguments: 1594 uint nargs = call->method()->arg_size(); 1595 for (uint i = 0; i < nargs; i++) { 1596 Node* arg = argument(i); 1597 call->init_req(i + TypeFunc::Parms, arg); 1598 } 1599 } 1600 1601 //---------------------------set_edges_for_java_call--------------------------- 1602 // Connect a newly created call into the current JVMS. 1603 // A return value node (if any) is returned from set_edges_for_java_call. 1604 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) { 1605 1606 // Add the predefined inputs: 1607 call->init_req( TypeFunc::Control, control() ); 1608 call->init_req( TypeFunc::I_O , i_o() ); 1609 call->init_req( TypeFunc::Memory , reset_memory() ); 1610 call->init_req( TypeFunc::FramePtr, frameptr() ); 1611 call->init_req( TypeFunc::ReturnAdr, top() ); 1612 1613 add_safepoint_edges(call, must_throw); 1614 1615 Node* xcall = _gvn.transform(call); 1616 1617 if (xcall == top()) { 1618 set_control(top()); 1619 return; 1620 } 1621 assert(xcall == call, "call identity is stable"); 1622 1623 // Re-use the current map to produce the result. 1624 1625 set_control(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Control))); 1626 set_i_o( _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O , separate_io_proj))); 1627 set_all_memory_call(xcall, separate_io_proj); 1628 1629 //return xcall; // no need, caller already has it 1630 } 1631 1632 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) { 1633 if (stopped()) return top(); // maybe the call folded up? 1634 1635 // Capture the return value, if any. 1636 Node* ret; 1637 if (call->method() == NULL || 1638 call->method()->return_type()->basic_type() == T_VOID) 1639 ret = top(); 1640 else ret = _gvn.transform(new (C, 1) ProjNode(call, TypeFunc::Parms)); 1641 1642 // Note: Since any out-of-line call can produce an exception, 1643 // we always insert an I_O projection from the call into the result. 1644 1645 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj); 1646 1647 if (separate_io_proj) { 1648 // The caller requested separate projections be used by the fall 1649 // through and exceptional paths, so replace the projections for 1650 // the fall through path. 1651 set_i_o(_gvn.transform( new (C, 1) ProjNode(call, TypeFunc::I_O) )); 1652 set_all_memory(_gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) )); 1653 } 1654 return ret; 1655 } 1656 1657 //--------------------set_predefined_input_for_runtime_call-------------------- 1658 // Reading and setting the memory state is way conservative here. 1659 // The real problem is that I am not doing real Type analysis on memory, 1660 // so I cannot distinguish card mark stores from other stores. Across a GC 1661 // point the Store Barrier and the card mark memory has to agree. I cannot 1662 // have a card mark store and its barrier split across the GC point from 1663 // either above or below. Here I get that to happen by reading ALL of memory. 1664 // A better answer would be to separate out card marks from other memory. 1665 // For now, return the input memory state, so that it can be reused 1666 // after the call, if this call has restricted memory effects. 1667 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) { 1668 // Set fixed predefined input arguments 1669 Node* memory = reset_memory(); 1670 call->init_req( TypeFunc::Control, control() ); 1671 call->init_req( TypeFunc::I_O, top() ); // does no i/o 1672 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs 1673 call->init_req( TypeFunc::FramePtr, frameptr() ); 1674 call->init_req( TypeFunc::ReturnAdr, top() ); 1675 return memory; 1676 } 1677 1678 //-------------------set_predefined_output_for_runtime_call-------------------- 1679 // Set control and memory (not i_o) from the call. 1680 // If keep_mem is not NULL, use it for the output state, 1681 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM. 1682 // If hook_mem is NULL, this call produces no memory effects at all. 1683 // If hook_mem is a Java-visible memory slice (such as arraycopy operands), 1684 // then only that memory slice is taken from the call. 1685 // In the last case, we must put an appropriate memory barrier before 1686 // the call, so as to create the correct anti-dependencies on loads 1687 // preceding the call. 1688 void GraphKit::set_predefined_output_for_runtime_call(Node* call, 1689 Node* keep_mem, 1690 const TypePtr* hook_mem) { 1691 // no i/o 1692 set_control(_gvn.transform( new (C, 1) ProjNode(call,TypeFunc::Control) )); 1693 if (keep_mem) { 1694 // First clone the existing memory state 1695 set_all_memory(keep_mem); 1696 if (hook_mem != NULL) { 1697 // Make memory for the call 1698 Node* mem = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::Memory) ); 1699 // Set the RawPtr memory state only. This covers all the heap top/GC stuff 1700 // We also use hook_mem to extract specific effects from arraycopy stubs. 1701 set_memory(mem, hook_mem); 1702 } 1703 // ...else the call has NO memory effects. 1704 1705 // Make sure the call advertises its memory effects precisely. 1706 // This lets us build accurate anti-dependences in gcm.cpp. 1707 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem), 1708 "call node must be constructed correctly"); 1709 } else { 1710 assert(hook_mem == NULL, ""); 1711 // This is not a "slow path" call; all memory comes from the call. 1712 set_all_memory_call(call); 1713 } 1714 } 1715 1716 1717 // Replace the call with the current state of the kit. 1718 void GraphKit::replace_call(CallNode* call, Node* result) { 1719 JVMState* ejvms = NULL; 1720 if (has_exceptions()) { 1721 ejvms = transfer_exceptions_into_jvms(); 1722 } 1723 1724 SafePointNode* final_state = stop(); 1725 1726 // Find all the needed outputs of this call 1727 CallProjections callprojs; 1728 call->extract_projections(&callprojs, true); 1729 1730 // Replace all the old call edges with the edges from the inlining result 1731 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_state->in(TypeFunc::Control)); 1732 C->gvn_replace_by(callprojs.fallthrough_memproj, final_state->in(TypeFunc::Memory)); 1733 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_state->in(TypeFunc::I_O)); 1734 1735 // Replace the result with the new result if it exists and is used 1736 if (callprojs.resproj != NULL && result != NULL) { 1737 C->gvn_replace_by(callprojs.resproj, result); 1738 } 1739 1740 if (ejvms == NULL) { 1741 // No exception edges to simply kill off those paths 1742 C->gvn_replace_by(callprojs.catchall_catchproj, C->top()); 1743 C->gvn_replace_by(callprojs.catchall_memproj, C->top()); 1744 C->gvn_replace_by(callprojs.catchall_ioproj, C->top()); 1745 1746 // Replace the old exception object with top 1747 if (callprojs.exobj != NULL) { 1748 C->gvn_replace_by(callprojs.exobj, C->top()); 1749 } 1750 } else { 1751 GraphKit ekit(ejvms); 1752 1753 // Load my combined exception state into the kit, with all phis transformed: 1754 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states(); 1755 1756 Node* ex_oop = ekit.use_exception_state(ex_map); 1757 1758 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control()); 1759 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory()); 1760 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o()); 1761 1762 // Replace the old exception object with the newly created one 1763 if (callprojs.exobj != NULL) { 1764 C->gvn_replace_by(callprojs.exobj, ex_oop); 1765 } 1766 } 1767 1768 // Disconnect the call from the graph 1769 call->disconnect_inputs(NULL); 1770 C->gvn_replace_by(call, C->top()); 1771 } 1772 1773 1774 //------------------------------increment_counter------------------------------ 1775 // for statistics: increment a VM counter by 1 1776 1777 void GraphKit::increment_counter(address counter_addr) { 1778 Node* adr1 = makecon(TypeRawPtr::make(counter_addr)); 1779 increment_counter(adr1); 1780 } 1781 1782 void GraphKit::increment_counter(Node* counter_addr) { 1783 int adr_type = Compile::AliasIdxRaw; 1784 Node* cnt = make_load(NULL, counter_addr, TypeInt::INT, T_INT, adr_type); 1785 Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1))); 1786 store_to_memory( NULL, counter_addr, incr, T_INT, adr_type ); 1787 } 1788 1789 1790 //------------------------------uncommon_trap---------------------------------- 1791 // Bail out to the interpreter in mid-method. Implemented by calling the 1792 // uncommon_trap blob. This helper function inserts a runtime call with the 1793 // right debug info. 1794 void GraphKit::uncommon_trap(int trap_request, 1795 ciKlass* klass, const char* comment, 1796 bool must_throw, 1797 bool keep_exact_action) { 1798 if (failing()) stop(); 1799 if (stopped()) return; // trap reachable? 1800 1801 // Note: If ProfileTraps is true, and if a deopt. actually 1802 // occurs here, the runtime will make sure an MDO exists. There is 1803 // no need to call method()->build_method_data() at this point. 1804 1805 #ifdef ASSERT 1806 if (!must_throw) { 1807 // Make sure the stack has at least enough depth to execute 1808 // the current bytecode. 1809 int inputs, ignore; 1810 if (compute_stack_effects(inputs, ignore)) { 1811 assert(sp() >= inputs, "must have enough JVMS stack to execute"); 1812 // It is a frequent error in library_call.cpp to issue an 1813 // uncommon trap with the _sp value already popped. 1814 } 1815 } 1816 #endif 1817 1818 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); 1819 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request); 1820 1821 switch (action) { 1822 case Deoptimization::Action_maybe_recompile: 1823 case Deoptimization::Action_reinterpret: 1824 // Temporary fix for 6529811 to allow virtual calls to be sure they 1825 // get the chance to go from mono->bi->mega 1826 if (!keep_exact_action && 1827 Deoptimization::trap_request_index(trap_request) < 0 && 1828 too_many_recompiles(reason)) { 1829 // This BCI is causing too many recompilations. 1830 action = Deoptimization::Action_none; 1831 trap_request = Deoptimization::make_trap_request(reason, action); 1832 } else { 1833 C->set_trap_can_recompile(true); 1834 } 1835 break; 1836 case Deoptimization::Action_make_not_entrant: 1837 C->set_trap_can_recompile(true); 1838 break; 1839 #ifdef ASSERT 1840 case Deoptimization::Action_none: 1841 case Deoptimization::Action_make_not_compilable: 1842 break; 1843 default: 1844 assert(false, "bad action"); 1845 #endif 1846 } 1847 1848 if (TraceOptoParse) { 1849 char buf[100]; 1850 tty->print_cr("Uncommon trap %s at bci:%d", 1851 Deoptimization::format_trap_request(buf, sizeof(buf), 1852 trap_request), bci()); 1853 } 1854 1855 CompileLog* log = C->log(); 1856 if (log != NULL) { 1857 int kid = (klass == NULL)? -1: log->identify(klass); 1858 log->begin_elem("uncommon_trap bci='%d'", bci()); 1859 char buf[100]; 1860 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf), 1861 trap_request)); 1862 if (kid >= 0) log->print(" klass='%d'", kid); 1863 if (comment != NULL) log->print(" comment='%s'", comment); 1864 log->end_elem(); 1865 } 1866 1867 // Make sure any guarding test views this path as very unlikely 1868 Node *i0 = control()->in(0); 1869 if (i0 != NULL && i0->is_If()) { // Found a guarding if test? 1870 IfNode *iff = i0->as_If(); 1871 float f = iff->_prob; // Get prob 1872 if (control()->Opcode() == Op_IfTrue) { 1873 if (f > PROB_UNLIKELY_MAG(4)) 1874 iff->_prob = PROB_MIN; 1875 } else { 1876 if (f < PROB_LIKELY_MAG(4)) 1877 iff->_prob = PROB_MAX; 1878 } 1879 } 1880 1881 // Clear out dead values from the debug info. 1882 kill_dead_locals(); 1883 1884 // Now insert the uncommon trap subroutine call 1885 address call_addr = SharedRuntime::uncommon_trap_blob()->instructions_begin(); 1886 const TypePtr* no_memory_effects = NULL; 1887 // Pass the index of the class to be loaded 1888 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON | 1889 (must_throw ? RC_MUST_THROW : 0), 1890 OptoRuntime::uncommon_trap_Type(), 1891 call_addr, "uncommon_trap", no_memory_effects, 1892 intcon(trap_request)); 1893 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request, 1894 "must extract request correctly from the graph"); 1895 assert(trap_request != 0, "zero value reserved by uncommon_trap_request"); 1896 1897 call->set_req(TypeFunc::ReturnAdr, returnadr()); 1898 // The debug info is the only real input to this call. 1899 1900 // Halt-and-catch fire here. The above call should never return! 1901 HaltNode* halt = new(C, TypeFunc::Parms) HaltNode(control(), frameptr()); 1902 _gvn.set_type_bottom(halt); 1903 root()->add_req(halt); 1904 1905 stop_and_kill_map(); 1906 } 1907 1908 1909 //--------------------------just_allocated_object------------------------------ 1910 // Report the object that was just allocated. 1911 // It must be the case that there are no intervening safepoints. 1912 // We use this to determine if an object is so "fresh" that 1913 // it does not require card marks. 1914 Node* GraphKit::just_allocated_object(Node* current_control) { 1915 if (C->recent_alloc_ctl() == current_control) 1916 return C->recent_alloc_obj(); 1917 return NULL; 1918 } 1919 1920 1921 void GraphKit::round_double_arguments(ciMethod* dest_method) { 1922 // (Note: TypeFunc::make has a cache that makes this fast.) 1923 const TypeFunc* tf = TypeFunc::make(dest_method); 1924 int nargs = tf->_domain->_cnt - TypeFunc::Parms; 1925 for (int j = 0; j < nargs; j++) { 1926 const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms); 1927 if( targ->basic_type() == T_DOUBLE ) { 1928 // If any parameters are doubles, they must be rounded before 1929 // the call, dstore_rounding does gvn.transform 1930 Node *arg = argument(j); 1931 arg = dstore_rounding(arg); 1932 set_argument(j, arg); 1933 } 1934 } 1935 } 1936 1937 void GraphKit::round_double_result(ciMethod* dest_method) { 1938 // A non-strict method may return a double value which has an extended 1939 // exponent, but this must not be visible in a caller which is 'strict' 1940 // If a strict caller invokes a non-strict callee, round a double result 1941 1942 BasicType result_type = dest_method->return_type()->basic_type(); 1943 assert( method() != NULL, "must have caller context"); 1944 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) { 1945 // Destination method's return value is on top of stack 1946 // dstore_rounding() does gvn.transform 1947 Node *result = pop_pair(); 1948 result = dstore_rounding(result); 1949 push_pair(result); 1950 } 1951 } 1952 1953 // rounding for strict float precision conformance 1954 Node* GraphKit::precision_rounding(Node* n) { 1955 return UseStrictFP && _method->flags().is_strict() 1956 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding 1957 ? _gvn.transform( new (C, 2) RoundFloatNode(0, n) ) 1958 : n; 1959 } 1960 1961 // rounding for strict double precision conformance 1962 Node* GraphKit::dprecision_rounding(Node *n) { 1963 return UseStrictFP && _method->flags().is_strict() 1964 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding 1965 ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) ) 1966 : n; 1967 } 1968 1969 // rounding for non-strict double stores 1970 Node* GraphKit::dstore_rounding(Node* n) { 1971 return Matcher::strict_fp_requires_explicit_rounding 1972 && UseSSE <= 1 1973 ? _gvn.transform( new (C, 2) RoundDoubleNode(0, n) ) 1974 : n; 1975 } 1976 1977 //============================================================================= 1978 // Generate a fast path/slow path idiom. Graph looks like: 1979 // [foo] indicates that 'foo' is a parameter 1980 // 1981 // [in] NULL 1982 // \ / 1983 // CmpP 1984 // Bool ne 1985 // If 1986 // / \ 1987 // True False-<2> 1988 // / | 1989 // / cast_not_null 1990 // Load | | ^ 1991 // [fast_test] | | 1992 // gvn to opt_test | | 1993 // / \ | <1> 1994 // True False | 1995 // | \\ | 1996 // [slow_call] \[fast_result] 1997 // Ctl Val \ \ 1998 // | \ \ 1999 // Catch <1> \ \ 2000 // / \ ^ \ \ 2001 // Ex No_Ex | \ \ 2002 // | \ \ | \ <2> \ 2003 // ... \ [slow_res] | | \ [null_result] 2004 // \ \--+--+--- | | 2005 // \ | / \ | / 2006 // --------Region Phi 2007 // 2008 //============================================================================= 2009 // Code is structured as a series of driver functions all called 'do_XXX' that 2010 // call a set of helper functions. Helper functions first, then drivers. 2011 2012 //------------------------------null_check_oop--------------------------------- 2013 // Null check oop. Set null-path control into Region in slot 3. 2014 // Make a cast-not-nullness use the other not-null control. Return cast. 2015 Node* GraphKit::null_check_oop(Node* value, Node* *null_control, 2016 bool never_see_null) { 2017 // Initial NULL check taken path 2018 (*null_control) = top(); 2019 Node* cast = null_check_common(value, T_OBJECT, false, null_control); 2020 2021 // Generate uncommon_trap: 2022 if (never_see_null && (*null_control) != top()) { 2023 // If we see an unexpected null at a check-cast we record it and force a 2024 // recompile; the offending check-cast will be compiled to handle NULLs. 2025 // If we see more than one offending BCI, then all checkcasts in the 2026 // method will be compiled to handle NULLs. 2027 PreserveJVMState pjvms(this); 2028 set_control(*null_control); 2029 replace_in_map(value, null()); 2030 uncommon_trap(Deoptimization::Reason_null_check, 2031 Deoptimization::Action_make_not_entrant); 2032 (*null_control) = top(); // NULL path is dead 2033 } 2034 2035 // Cast away null-ness on the result 2036 return cast; 2037 } 2038 2039 //------------------------------opt_iff---------------------------------------- 2040 // Optimize the fast-check IfNode. Set the fast-path region slot 2. 2041 // Return slow-path control. 2042 Node* GraphKit::opt_iff(Node* region, Node* iff) { 2043 IfNode *opt_iff = _gvn.transform(iff)->as_If(); 2044 2045 // Fast path taken; set region slot 2 2046 Node *fast_taken = _gvn.transform( new (C, 1) IfFalseNode(opt_iff) ); 2047 region->init_req(2,fast_taken); // Capture fast-control 2048 2049 // Fast path not-taken, i.e. slow path 2050 Node *slow_taken = _gvn.transform( new (C, 1) IfTrueNode(opt_iff) ); 2051 return slow_taken; 2052 } 2053 2054 //-----------------------------make_runtime_call------------------------------- 2055 Node* GraphKit::make_runtime_call(int flags, 2056 const TypeFunc* call_type, address call_addr, 2057 const char* call_name, 2058 const TypePtr* adr_type, 2059 // The following parms are all optional. 2060 // The first NULL ends the list. 2061 Node* parm0, Node* parm1, 2062 Node* parm2, Node* parm3, 2063 Node* parm4, Node* parm5, 2064 Node* parm6, Node* parm7) { 2065 // Slow-path call 2066 int size = call_type->domain()->cnt(); 2067 bool is_leaf = !(flags & RC_NO_LEAF); 2068 bool has_io = (!is_leaf && !(flags & RC_NO_IO)); 2069 if (call_name == NULL) { 2070 assert(!is_leaf, "must supply name for leaf"); 2071 call_name = OptoRuntime::stub_name(call_addr); 2072 } 2073 CallNode* call; 2074 if (!is_leaf) { 2075 call = new(C, size) CallStaticJavaNode(call_type, call_addr, call_name, 2076 bci(), adr_type); 2077 } else if (flags & RC_NO_FP) { 2078 call = new(C, size) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type); 2079 } else { 2080 call = new(C, size) CallLeafNode(call_type, call_addr, call_name, adr_type); 2081 } 2082 2083 // The following is similar to set_edges_for_java_call, 2084 // except that the memory effects of the call are restricted to AliasIdxRaw. 2085 2086 // Slow path call has no side-effects, uses few values 2087 bool wide_in = !(flags & RC_NARROW_MEM); 2088 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot); 2089 2090 Node* prev_mem = NULL; 2091 if (wide_in) { 2092 prev_mem = set_predefined_input_for_runtime_call(call); 2093 } else { 2094 assert(!wide_out, "narrow in => narrow out"); 2095 Node* narrow_mem = memory(adr_type); 2096 prev_mem = reset_memory(); 2097 map()->set_memory(narrow_mem); 2098 set_predefined_input_for_runtime_call(call); 2099 } 2100 2101 // Hook each parm in order. Stop looking at the first NULL. 2102 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0); 2103 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1); 2104 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2); 2105 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3); 2106 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4); 2107 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5); 2108 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6); 2109 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7); 2110 /* close each nested if ===> */ } } } } } } } } 2111 assert(call->in(call->req()-1) != NULL, "must initialize all parms"); 2112 2113 if (!is_leaf) { 2114 // Non-leaves can block and take safepoints: 2115 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0)); 2116 } 2117 // Non-leaves can throw exceptions: 2118 if (has_io) { 2119 call->set_req(TypeFunc::I_O, i_o()); 2120 } 2121 2122 if (flags & RC_UNCOMMON) { 2123 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency. 2124 // (An "if" probability corresponds roughly to an unconditional count. 2125 // Sort of.) 2126 call->set_cnt(PROB_UNLIKELY_MAG(4)); 2127 } 2128 2129 Node* c = _gvn.transform(call); 2130 assert(c == call, "cannot disappear"); 2131 2132 if (wide_out) { 2133 // Slow path call has full side-effects. 2134 set_predefined_output_for_runtime_call(call); 2135 } else { 2136 // Slow path call has few side-effects, and/or sets few values. 2137 set_predefined_output_for_runtime_call(call, prev_mem, adr_type); 2138 } 2139 2140 if (has_io) { 2141 set_i_o(_gvn.transform(new (C, 1) ProjNode(call, TypeFunc::I_O))); 2142 } 2143 return call; 2144 2145 } 2146 2147 //------------------------------merge_memory----------------------------------- 2148 // Merge memory from one path into the current memory state. 2149 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) { 2150 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) { 2151 Node* old_slice = mms.force_memory(); 2152 Node* new_slice = mms.memory2(); 2153 if (old_slice != new_slice) { 2154 PhiNode* phi; 2155 if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) { 2156 phi = new_slice->as_Phi(); 2157 #ifdef ASSERT 2158 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) 2159 old_slice = old_slice->in(new_path); 2160 // Caller is responsible for ensuring that any pre-existing 2161 // phis are already aware of old memory. 2162 int old_path = (new_path > 1) ? 1 : 2; // choose old_path != new_path 2163 assert(phi->in(old_path) == old_slice, "pre-existing phis OK"); 2164 #endif 2165 mms.set_memory(phi); 2166 } else { 2167 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C)); 2168 _gvn.set_type(phi, Type::MEMORY); 2169 phi->set_req(new_path, new_slice); 2170 mms.set_memory(_gvn.transform(phi)); // assume it is complete 2171 } 2172 } 2173 } 2174 } 2175 2176 //------------------------------make_slow_call_ex------------------------------ 2177 // Make the exception handler hookups for the slow call 2178 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) { 2179 if (stopped()) return; 2180 2181 // Make a catch node with just two handlers: fall-through and catch-all 2182 Node* i_o = _gvn.transform( new (C, 1) ProjNode(call, TypeFunc::I_O, separate_io_proj) ); 2183 Node* catc = _gvn.transform( new (C, 2) CatchNode(control(), i_o, 2) ); 2184 Node* norm = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) ); 2185 Node* excp = _gvn.transform( new (C, 1) CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) ); 2186 2187 { PreserveJVMState pjvms(this); 2188 set_control(excp); 2189 set_i_o(i_o); 2190 2191 if (excp != top()) { 2192 // Create an exception state also. 2193 // Use an exact type if the caller has specified a specific exception. 2194 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull); 2195 Node* ex_oop = new (C, 2) CreateExNode(ex_type, control(), i_o); 2196 add_exception_state(make_exception_state(_gvn.transform(ex_oop))); 2197 } 2198 } 2199 2200 // Get the no-exception control from the CatchNode. 2201 set_control(norm); 2202 } 2203 2204 2205 //-------------------------------gen_subtype_check----------------------------- 2206 // Generate a subtyping check. Takes as input the subtype and supertype. 2207 // Returns 2 values: sets the default control() to the true path and returns 2208 // the false path. Only reads invariant memory; sets no (visible) memory. 2209 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding 2210 // but that's not exposed to the optimizer. This call also doesn't take in an 2211 // Object; if you wish to check an Object you need to load the Object's class 2212 // prior to coming here. 2213 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) { 2214 // Fast check for identical types, perhaps identical constants. 2215 // The types can even be identical non-constants, in cases 2216 // involving Array.newInstance, Object.clone, etc. 2217 if (subklass == superklass) 2218 return top(); // false path is dead; no test needed. 2219 2220 if (_gvn.type(superklass)->singleton()) { 2221 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass(); 2222 ciKlass* subk = _gvn.type(subklass)->is_klassptr()->klass(); 2223 2224 // In the common case of an exact superklass, try to fold up the 2225 // test before generating code. You may ask, why not just generate 2226 // the code and then let it fold up? The answer is that the generated 2227 // code will necessarily include null checks, which do not always 2228 // completely fold away. If they are also needless, then they turn 2229 // into a performance loss. Example: 2230 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x; 2231 // Here, the type of 'fa' is often exact, so the store check 2232 // of fa[1]=x will fold up, without testing the nullness of x. 2233 switch (static_subtype_check(superk, subk)) { 2234 case SSC_always_false: 2235 { 2236 Node* always_fail = control(); 2237 set_control(top()); 2238 return always_fail; 2239 } 2240 case SSC_always_true: 2241 return top(); 2242 case SSC_easy_test: 2243 { 2244 // Just do a direct pointer compare and be done. 2245 Node* cmp = _gvn.transform( new(C, 3) CmpPNode(subklass, superklass) ); 2246 Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) ); 2247 IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN); 2248 set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) ) ); 2249 return _gvn.transform( new(C, 1) IfFalseNode(iff) ); 2250 } 2251 case SSC_full_test: 2252 break; 2253 default: 2254 ShouldNotReachHere(); 2255 } 2256 } 2257 2258 // %%% Possible further optimization: Even if the superklass is not exact, 2259 // if the subklass is the unique subtype of the superklass, the check 2260 // will always succeed. We could leave a dependency behind to ensure this. 2261 2262 // First load the super-klass's check-offset 2263 Node *p1 = basic_plus_adr( superklass, superklass, sizeof(oopDesc) + Klass::super_check_offset_offset_in_bytes() ); 2264 Node *chk_off = _gvn.transform( new (C, 3) LoadINode( NULL, memory(p1), p1, _gvn.type(p1)->is_ptr() ) ); 2265 int cacheoff_con = sizeof(oopDesc) + Klass::secondary_super_cache_offset_in_bytes(); 2266 bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con); 2267 2268 // Load from the sub-klass's super-class display list, or a 1-word cache of 2269 // the secondary superclass list, or a failing value with a sentinel offset 2270 // if the super-klass is an interface or exceptionally deep in the Java 2271 // hierarchy and we have to scan the secondary superclass list the hard way. 2272 // Worst-case type is a little odd: NULL is allowed as a result (usually 2273 // klass loads can never produce a NULL). 2274 Node *chk_off_X = ConvI2X(chk_off); 2275 Node *p2 = _gvn.transform( new (C, 4) AddPNode(subklass,subklass,chk_off_X) ); 2276 // For some types like interfaces the following loadKlass is from a 1-word 2277 // cache which is mutable so can't use immutable memory. Other 2278 // types load from the super-class display table which is immutable. 2279 Node *kmem = might_be_cache ? memory(p2) : immutable_memory(); 2280 Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) ); 2281 2282 // Compile speed common case: ARE a subtype and we canNOT fail 2283 if( superklass == nkls ) 2284 return top(); // false path is dead; no test needed. 2285 2286 // See if we get an immediate positive hit. Happens roughly 83% of the 2287 // time. Test to see if the value loaded just previously from the subklass 2288 // is exactly the superklass. 2289 Node *cmp1 = _gvn.transform( new (C, 3) CmpPNode( superklass, nkls ) ); 2290 Node *bol1 = _gvn.transform( new (C, 2) BoolNode( cmp1, BoolTest::eq ) ); 2291 IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN ); 2292 Node *iftrue1 = _gvn.transform( new (C, 1) IfTrueNode ( iff1 ) ); 2293 set_control( _gvn.transform( new (C, 1) IfFalseNode( iff1 ) ) ); 2294 2295 // Compile speed common case: Check for being deterministic right now. If 2296 // chk_off is a constant and not equal to cacheoff then we are NOT a 2297 // subklass. In this case we need exactly the 1 test above and we can 2298 // return those results immediately. 2299 if (!might_be_cache) { 2300 Node* not_subtype_ctrl = control(); 2301 set_control(iftrue1); // We need exactly the 1 test above 2302 return not_subtype_ctrl; 2303 } 2304 2305 // Gather the various success & failures here 2306 RegionNode *r_ok_subtype = new (C, 4) RegionNode(4); 2307 record_for_igvn(r_ok_subtype); 2308 RegionNode *r_not_subtype = new (C, 3) RegionNode(3); 2309 record_for_igvn(r_not_subtype); 2310 2311 r_ok_subtype->init_req(1, iftrue1); 2312 2313 // Check for immediate negative hit. Happens roughly 11% of the time (which 2314 // is roughly 63% of the remaining cases). Test to see if the loaded 2315 // check-offset points into the subklass display list or the 1-element 2316 // cache. If it points to the display (and NOT the cache) and the display 2317 // missed then it's not a subtype. 2318 Node *cacheoff = _gvn.intcon(cacheoff_con); 2319 Node *cmp2 = _gvn.transform( new (C, 3) CmpINode( chk_off, cacheoff ) ); 2320 Node *bol2 = _gvn.transform( new (C, 2) BoolNode( cmp2, BoolTest::ne ) ); 2321 IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN ); 2322 r_not_subtype->init_req(1, _gvn.transform( new (C, 1) IfTrueNode (iff2) ) ); 2323 set_control( _gvn.transform( new (C, 1) IfFalseNode(iff2) ) ); 2324 2325 // Check for self. Very rare to get here, but it is taken 1/3 the time. 2326 // No performance impact (too rare) but allows sharing of secondary arrays 2327 // which has some footprint reduction. 2328 Node *cmp3 = _gvn.transform( new (C, 3) CmpPNode( subklass, superklass ) ); 2329 Node *bol3 = _gvn.transform( new (C, 2) BoolNode( cmp3, BoolTest::eq ) ); 2330 IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN ); 2331 r_ok_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode ( iff3 ) ) ); 2332 set_control( _gvn.transform( new (C, 1) IfFalseNode( iff3 ) ) ); 2333 2334 // -- Roads not taken here: -- 2335 // We could also have chosen to perform the self-check at the beginning 2336 // of this code sequence, as the assembler does. This would not pay off 2337 // the same way, since the optimizer, unlike the assembler, can perform 2338 // static type analysis to fold away many successful self-checks. 2339 // Non-foldable self checks work better here in second position, because 2340 // the initial primary superclass check subsumes a self-check for most 2341 // types. An exception would be a secondary type like array-of-interface, 2342 // which does not appear in its own primary supertype display. 2343 // Finally, we could have chosen to move the self-check into the 2344 // PartialSubtypeCheckNode, and from there out-of-line in a platform 2345 // dependent manner. But it is worthwhile to have the check here, 2346 // where it can be perhaps be optimized. The cost in code space is 2347 // small (register compare, branch). 2348 2349 // Now do a linear scan of the secondary super-klass array. Again, no real 2350 // performance impact (too rare) but it's gotta be done. 2351 // Since the code is rarely used, there is no penalty for moving it 2352 // out of line, and it can only improve I-cache density. 2353 // The decision to inline or out-of-line this final check is platform 2354 // dependent, and is found in the AD file definition of PartialSubtypeCheck. 2355 Node* psc = _gvn.transform( 2356 new (C, 3) PartialSubtypeCheckNode(control(), subklass, superklass) ); 2357 2358 Node *cmp4 = _gvn.transform( new (C, 3) CmpPNode( psc, null() ) ); 2359 Node *bol4 = _gvn.transform( new (C, 2) BoolNode( cmp4, BoolTest::ne ) ); 2360 IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN ); 2361 r_not_subtype->init_req(2, _gvn.transform( new (C, 1) IfTrueNode (iff4) ) ); 2362 r_ok_subtype ->init_req(3, _gvn.transform( new (C, 1) IfFalseNode(iff4) ) ); 2363 2364 // Return false path; set default control to true path. 2365 set_control( _gvn.transform(r_ok_subtype) ); 2366 return _gvn.transform(r_not_subtype); 2367 } 2368 2369 //----------------------------static_subtype_check----------------------------- 2370 // Shortcut important common cases when superklass is exact: 2371 // (0) superklass is java.lang.Object (can occur in reflective code) 2372 // (1) subklass is already limited to a subtype of superklass => always ok 2373 // (2) subklass does not overlap with superklass => always fail 2374 // (3) superklass has NO subtypes and we can check with a simple compare. 2375 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) { 2376 if (StressReflectiveCode) { 2377 return SSC_full_test; // Let caller generate the general case. 2378 } 2379 2380 if (superk == env()->Object_klass()) { 2381 return SSC_always_true; // (0) this test cannot fail 2382 } 2383 2384 ciType* superelem = superk; 2385 if (superelem->is_array_klass()) 2386 superelem = superelem->as_array_klass()->base_element_type(); 2387 2388 if (!subk->is_interface()) { // cannot trust static interface types yet 2389 if (subk->is_subtype_of(superk)) { 2390 return SSC_always_true; // (1) false path dead; no dynamic test needed 2391 } 2392 if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) && 2393 !superk->is_subtype_of(subk)) { 2394 return SSC_always_false; 2395 } 2396 } 2397 2398 // If casting to an instance klass, it must have no subtypes 2399 if (superk->is_interface()) { 2400 // Cannot trust interfaces yet. 2401 // %%% S.B. superk->nof_implementors() == 1 2402 } else if (superelem->is_instance_klass()) { 2403 ciInstanceKlass* ik = superelem->as_instance_klass(); 2404 if (!ik->has_subklass() && !ik->is_interface()) { 2405 if (!ik->is_final()) { 2406 // Add a dependency if there is a chance of a later subclass. 2407 C->dependencies()->assert_leaf_type(ik); 2408 } 2409 return SSC_easy_test; // (3) caller can do a simple ptr comparison 2410 } 2411 } else { 2412 // A primitive array type has no subtypes. 2413 return SSC_easy_test; // (3) caller can do a simple ptr comparison 2414 } 2415 2416 return SSC_full_test; 2417 } 2418 2419 // Profile-driven exact type check: 2420 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass, 2421 float prob, 2422 Node* *casted_receiver) { 2423 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass); 2424 Node* recv_klass = load_object_klass(receiver); 2425 Node* want_klass = makecon(tklass); 2426 Node* cmp = _gvn.transform( new(C, 3) CmpPNode(recv_klass, want_klass) ); 2427 Node* bol = _gvn.transform( new(C, 2) BoolNode(cmp, BoolTest::eq) ); 2428 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN); 2429 set_control( _gvn.transform( new(C, 1) IfTrueNode (iff) )); 2430 Node* fail = _gvn.transform( new(C, 1) IfFalseNode(iff) ); 2431 2432 const TypeOopPtr* recv_xtype = tklass->as_instance_type(); 2433 assert(recv_xtype->klass_is_exact(), ""); 2434 2435 // Subsume downstream occurrences of receiver with a cast to 2436 // recv_xtype, since now we know what the type will be. 2437 Node* cast = new(C, 2) CheckCastPPNode(control(), receiver, recv_xtype); 2438 (*casted_receiver) = _gvn.transform(cast); 2439 // (User must make the replace_in_map call.) 2440 2441 return fail; 2442 } 2443 2444 2445 //-------------------------------gen_instanceof-------------------------------- 2446 // Generate an instance-of idiom. Used by both the instance-of bytecode 2447 // and the reflective instance-of call. 2448 Node* GraphKit::gen_instanceof( Node *subobj, Node* superklass ) { 2449 C->set_has_split_ifs(true); // Has chance for split-if optimization 2450 assert( !stopped(), "dead parse path should be checked in callers" ); 2451 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()), 2452 "must check for not-null not-dead klass in callers"); 2453 2454 // Make the merge point 2455 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT }; 2456 RegionNode* region = new(C, PATH_LIMIT) RegionNode(PATH_LIMIT); 2457 Node* phi = new(C, PATH_LIMIT) PhiNode(region, TypeInt::BOOL); 2458 C->set_has_split_ifs(true); // Has chance for split-if optimization 2459 2460 // Null check; get casted pointer; set region slot 3 2461 Node* null_ctl = top(); 2462 Node* not_null_obj = null_check_oop(subobj, &null_ctl); 2463 2464 // If not_null_obj is dead, only null-path is taken 2465 if (stopped()) { // Doing instance-of on a NULL? 2466 set_control(null_ctl); 2467 return intcon(0); 2468 } 2469 region->init_req(_null_path, null_ctl); 2470 phi ->init_req(_null_path, intcon(0)); // Set null path value 2471 2472 // Load the object's klass 2473 Node* obj_klass = load_object_klass(not_null_obj); 2474 2475 // Generate the subtype check 2476 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass); 2477 2478 // Plug in the success path to the general merge in slot 1. 2479 region->init_req(_obj_path, control()); 2480 phi ->init_req(_obj_path, intcon(1)); 2481 2482 // Plug in the failing path to the general merge in slot 2. 2483 region->init_req(_fail_path, not_subtype_ctrl); 2484 phi ->init_req(_fail_path, intcon(0)); 2485 2486 // Return final merged results 2487 set_control( _gvn.transform(region) ); 2488 record_for_igvn(region); 2489 return _gvn.transform(phi); 2490 } 2491 2492 //-------------------------------gen_checkcast--------------------------------- 2493 // Generate a checkcast idiom. Used by both the checkcast bytecode and the 2494 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the 2495 // uncommon-trap paths work. Adjust stack after this call. 2496 // If failure_control is supplied and not null, it is filled in with 2497 // the control edge for the cast failure. Otherwise, an appropriate 2498 // uncommon trap or exception is thrown. 2499 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass, 2500 Node* *failure_control) { 2501 kill_dead_locals(); // Benefit all the uncommon traps 2502 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr(); 2503 const Type *toop = TypeOopPtr::make_from_klass(tk->klass()); 2504 2505 // Fast cutout: Check the case that the cast is vacuously true. 2506 // This detects the common cases where the test will short-circuit 2507 // away completely. We do this before we perform the null check, 2508 // because if the test is going to turn into zero code, we don't 2509 // want a residual null check left around. (Causes a slowdown, 2510 // for example, in some objArray manipulations, such as a[i]=a[j].) 2511 if (tk->singleton()) { 2512 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr(); 2513 if (objtp != NULL && objtp->klass() != NULL) { 2514 switch (static_subtype_check(tk->klass(), objtp->klass())) { 2515 case SSC_always_true: 2516 return obj; 2517 case SSC_always_false: 2518 // It needs a null check because a null will *pass* the cast check. 2519 // A non-null value will always produce an exception. 2520 return do_null_assert(obj, T_OBJECT); 2521 } 2522 } 2523 } 2524 2525 ciProfileData* data = NULL; 2526 if (failure_control == NULL) { // use MDO in regular case only 2527 assert(java_bc() == Bytecodes::_aastore || 2528 java_bc() == Bytecodes::_checkcast, 2529 "interpreter profiles type checks only for these BCs"); 2530 data = method()->method_data()->bci_to_data(bci()); 2531 } 2532 2533 // Make the merge point 2534 enum { _obj_path = 1, _null_path, PATH_LIMIT }; 2535 RegionNode* region = new (C, PATH_LIMIT) RegionNode(PATH_LIMIT); 2536 Node* phi = new (C, PATH_LIMIT) PhiNode(region, toop); 2537 C->set_has_split_ifs(true); // Has chance for split-if optimization 2538 2539 // Use null-cast information if it is available 2540 bool never_see_null = false; 2541 // If we see an unexpected null at a check-cast we record it and force a 2542 // recompile; the offending check-cast will be compiled to handle NULLs. 2543 // If we see several offending BCIs, then all checkcasts in the 2544 // method will be compiled to handle NULLs. 2545 if (UncommonNullCast // Cutout for this technique 2546 && failure_control == NULL // regular case 2547 && obj != null() // And not the -Xcomp stupid case? 2548 && !too_many_traps(Deoptimization::Reason_null_check)) { 2549 // Finally, check the "null_seen" bit from the interpreter. 2550 if (data == NULL || !data->as_BitData()->null_seen()) { 2551 never_see_null = true; 2552 } 2553 } 2554 2555 // Null check; get casted pointer; set region slot 3 2556 Node* null_ctl = top(); 2557 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null); 2558 2559 // If not_null_obj is dead, only null-path is taken 2560 if (stopped()) { // Doing instance-of on a NULL? 2561 set_control(null_ctl); 2562 return null(); 2563 } 2564 region->init_req(_null_path, null_ctl); 2565 phi ->init_req(_null_path, null()); // Set null path value 2566 2567 Node* cast_obj = NULL; // the casted version of the object 2568 2569 // If the profile has seen exactly one type, narrow to that type. 2570 // (The subsequent subtype check will always fold up.) 2571 if (UseTypeProfile && TypeProfileCasts && data != NULL && 2572 // Counter has never been decremented (due to cast failure). 2573 // ...This is a reasonable thing to expect. It is true of 2574 // all casts inserted by javac to implement generic types. 2575 data->as_CounterData()->count() >= 0 && 2576 !too_many_traps(Deoptimization::Reason_class_check)) { 2577 // (No, this isn't a call, but it's enough like a virtual call 2578 // to use the same ciMethod accessor to get the profile info...) 2579 ciCallProfile profile = method()->call_profile_at_bci(bci()); 2580 if (profile.count() >= 0 && // no cast failures here 2581 profile.has_receiver(0) && 2582 profile.morphism() == 1) { 2583 ciKlass* exact_kls = profile.receiver(0); 2584 int ssc = static_subtype_check(tk->klass(), exact_kls); 2585 if (ssc == SSC_always_true) { 2586 // If we narrow the type to match what the type profile sees, 2587 // we can then remove the rest of the cast. 2588 // This is a win, even if the exact_kls is very specific, 2589 // because downstream operations, such as method calls, 2590 // will often benefit from the sharper type. 2591 Node* exact_obj = not_null_obj; // will get updated in place... 2592 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, 2593 &exact_obj); 2594 { PreserveJVMState pjvms(this); 2595 set_control(slow_ctl); 2596 uncommon_trap(Deoptimization::Reason_class_check, 2597 Deoptimization::Action_maybe_recompile); 2598 } 2599 if (failure_control != NULL) // failure is now impossible 2600 (*failure_control) = top(); 2601 replace_in_map(not_null_obj, exact_obj); 2602 // adjust the type of the phi to the exact klass: 2603 phi->raise_bottom_type(_gvn.type(exact_obj)->meet(TypePtr::NULL_PTR)); 2604 cast_obj = exact_obj; 2605 } 2606 // assert(cast_obj != NULL)... except maybe the profile lied to us. 2607 } 2608 } 2609 2610 if (cast_obj == NULL) { 2611 // Load the object's klass 2612 Node* obj_klass = load_object_klass(not_null_obj); 2613 2614 // Generate the subtype check 2615 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass ); 2616 2617 // Plug in success path into the merge 2618 cast_obj = _gvn.transform(new (C, 2) CheckCastPPNode(control(), 2619 not_null_obj, toop)); 2620 // Failure path ends in uncommon trap (or may be dead - failure impossible) 2621 if (failure_control == NULL) { 2622 if (not_subtype_ctrl != top()) { // If failure is possible 2623 PreserveJVMState pjvms(this); 2624 set_control(not_subtype_ctrl); 2625 builtin_throw(Deoptimization::Reason_class_check, obj_klass); 2626 } 2627 } else { 2628 (*failure_control) = not_subtype_ctrl; 2629 } 2630 } 2631 2632 region->init_req(_obj_path, control()); 2633 phi ->init_req(_obj_path, cast_obj); 2634 2635 // A merge of NULL or Casted-NotNull obj 2636 Node* res = _gvn.transform(phi); 2637 2638 // Note I do NOT always 'replace_in_map(obj,result)' here. 2639 // if( tk->klass()->can_be_primary_super() ) 2640 // This means that if I successfully store an Object into an array-of-String 2641 // I 'forget' that the Object is really now known to be a String. I have to 2642 // do this because we don't have true union types for interfaces - if I store 2643 // a Baz into an array-of-Interface and then tell the optimizer it's an 2644 // Interface, I forget that it's also a Baz and cannot do Baz-like field 2645 // references to it. FIX THIS WHEN UNION TYPES APPEAR! 2646 // replace_in_map( obj, res ); 2647 2648 // Return final merged results 2649 set_control( _gvn.transform(region) ); 2650 record_for_igvn(region); 2651 return res; 2652 } 2653 2654 //------------------------------next_monitor----------------------------------- 2655 // What number should be given to the next monitor? 2656 int GraphKit::next_monitor() { 2657 int current = jvms()->monitor_depth()* C->sync_stack_slots(); 2658 int next = current + C->sync_stack_slots(); 2659 // Keep the toplevel high water mark current: 2660 if (C->fixed_slots() < next) C->set_fixed_slots(next); 2661 return current; 2662 } 2663 2664 //------------------------------insert_mem_bar--------------------------------- 2665 // Memory barrier to avoid floating things around 2666 // The membar serves as a pinch point between both control and all memory slices. 2667 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) { 2668 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent); 2669 mb->init_req(TypeFunc::Control, control()); 2670 mb->init_req(TypeFunc::Memory, reset_memory()); 2671 Node* membar = _gvn.transform(mb); 2672 set_control(_gvn.transform(new (C, 1) ProjNode(membar,TypeFunc::Control) )); 2673 set_all_memory_call(membar); 2674 return membar; 2675 } 2676 2677 //-------------------------insert_mem_bar_volatile---------------------------- 2678 // Memory barrier to avoid floating things around 2679 // The membar serves as a pinch point between both control and memory(alias_idx). 2680 // If you want to make a pinch point on all memory slices, do not use this 2681 // function (even with AliasIdxBot); use insert_mem_bar() instead. 2682 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) { 2683 // When Parse::do_put_xxx updates a volatile field, it appends a series 2684 // of MemBarVolatile nodes, one for *each* volatile field alias category. 2685 // The first membar is on the same memory slice as the field store opcode. 2686 // This forces the membar to follow the store. (Bug 6500685 broke this.) 2687 // All the other membars (for other volatile slices, including AliasIdxBot, 2688 // which stands for all unknown volatile slices) are control-dependent 2689 // on the first membar. This prevents later volatile loads or stores 2690 // from sliding up past the just-emitted store. 2691 2692 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent); 2693 mb->set_req(TypeFunc::Control,control()); 2694 if (alias_idx == Compile::AliasIdxBot) { 2695 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory()); 2696 } else { 2697 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller"); 2698 mb->set_req(TypeFunc::Memory, memory(alias_idx)); 2699 } 2700 Node* membar = _gvn.transform(mb); 2701 set_control(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Control))); 2702 if (alias_idx == Compile::AliasIdxBot) { 2703 merged_memory()->set_base_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory))); 2704 } else { 2705 set_memory(_gvn.transform(new (C, 1) ProjNode(membar, TypeFunc::Memory)),alias_idx); 2706 } 2707 return membar; 2708 } 2709 2710 //------------------------------shared_lock------------------------------------ 2711 // Emit locking code. 2712 FastLockNode* GraphKit::shared_lock(Node* obj) { 2713 // bci is either a monitorenter bc or InvocationEntryBci 2714 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces 2715 assert(SynchronizationEntryBCI == InvocationEntryBci, ""); 2716 2717 if( !GenerateSynchronizationCode ) 2718 return NULL; // Not locking things? 2719 if (stopped()) // Dead monitor? 2720 return NULL; 2721 2722 assert(dead_locals_are_killed(), "should kill locals before sync. point"); 2723 2724 // Box the stack location 2725 Node* box = _gvn.transform(new (C, 1) BoxLockNode(next_monitor())); 2726 Node* mem = reset_memory(); 2727 2728 FastLockNode * flock = _gvn.transform(new (C, 3) FastLockNode(0, obj, box) )->as_FastLock(); 2729 if (PrintPreciseBiasedLockingStatistics) { 2730 // Create the counters for this fast lock. 2731 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci 2732 } 2733 // Add monitor to debug info for the slow path. If we block inside the 2734 // slow path and de-opt, we need the monitor hanging around 2735 map()->push_monitor( flock ); 2736 2737 const TypeFunc *tf = LockNode::lock_type(); 2738 LockNode *lock = new (C, tf->domain()->cnt()) LockNode(C, tf); 2739 2740 lock->init_req( TypeFunc::Control, control() ); 2741 lock->init_req( TypeFunc::Memory , mem ); 2742 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o 2743 lock->init_req( TypeFunc::FramePtr, frameptr() ); 2744 lock->init_req( TypeFunc::ReturnAdr, top() ); 2745 2746 lock->init_req(TypeFunc::Parms + 0, obj); 2747 lock->init_req(TypeFunc::Parms + 1, box); 2748 lock->init_req(TypeFunc::Parms + 2, flock); 2749 add_safepoint_edges(lock); 2750 2751 lock = _gvn.transform( lock )->as_Lock(); 2752 2753 // lock has no side-effects, sets few values 2754 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM); 2755 2756 insert_mem_bar(Op_MemBarAcquire); 2757 2758 // Add this to the worklist so that the lock can be eliminated 2759 record_for_igvn(lock); 2760 2761 #ifndef PRODUCT 2762 if (PrintLockStatistics) { 2763 // Update the counter for this lock. Don't bother using an atomic 2764 // operation since we don't require absolute accuracy. 2765 lock->create_lock_counter(map()->jvms()); 2766 int adr_type = Compile::AliasIdxRaw; 2767 Node* counter_addr = makecon(TypeRawPtr::make(lock->counter()->addr())); 2768 Node* cnt = make_load(NULL, counter_addr, TypeInt::INT, T_INT, adr_type); 2769 Node* incr = _gvn.transform(new (C, 3) AddINode(cnt, _gvn.intcon(1))); 2770 store_to_memory(control(), counter_addr, incr, T_INT, adr_type); 2771 } 2772 #endif 2773 2774 return flock; 2775 } 2776 2777 2778 //------------------------------shared_unlock---------------------------------- 2779 // Emit unlocking code. 2780 void GraphKit::shared_unlock(Node* box, Node* obj) { 2781 // bci is either a monitorenter bc or InvocationEntryBci 2782 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces 2783 assert(SynchronizationEntryBCI == InvocationEntryBci, ""); 2784 2785 if( !GenerateSynchronizationCode ) 2786 return; 2787 if (stopped()) { // Dead monitor? 2788 map()->pop_monitor(); // Kill monitor from debug info 2789 return; 2790 } 2791 2792 // Memory barrier to avoid floating things down past the locked region 2793 insert_mem_bar(Op_MemBarRelease); 2794 2795 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type(); 2796 UnlockNode *unlock = new (C, tf->domain()->cnt()) UnlockNode(C, tf); 2797 uint raw_idx = Compile::AliasIdxRaw; 2798 unlock->init_req( TypeFunc::Control, control() ); 2799 unlock->init_req( TypeFunc::Memory , memory(raw_idx) ); 2800 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o 2801 unlock->init_req( TypeFunc::FramePtr, frameptr() ); 2802 unlock->init_req( TypeFunc::ReturnAdr, top() ); 2803 2804 unlock->init_req(TypeFunc::Parms + 0, obj); 2805 unlock->init_req(TypeFunc::Parms + 1, box); 2806 unlock = _gvn.transform(unlock)->as_Unlock(); 2807 2808 Node* mem = reset_memory(); 2809 2810 // unlock has no side-effects, sets few values 2811 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM); 2812 2813 // Kill monitor from debug info 2814 map()->pop_monitor( ); 2815 } 2816 2817 //-------------------------------get_layout_helper----------------------------- 2818 // If the given klass is a constant or known to be an array, 2819 // fetch the constant layout helper value into constant_value 2820 // and return (Node*)NULL. Otherwise, load the non-constant 2821 // layout helper value, and return the node which represents it. 2822 // This two-faced routine is useful because allocation sites 2823 // almost always feature constant types. 2824 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) { 2825 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr(); 2826 if (!StressReflectiveCode && inst_klass != NULL) { 2827 ciKlass* klass = inst_klass->klass(); 2828 bool xklass = inst_klass->klass_is_exact(); 2829 if (xklass || klass->is_array_klass()) { 2830 jint lhelper = klass->layout_helper(); 2831 if (lhelper != Klass::_lh_neutral_value) { 2832 constant_value = lhelper; 2833 return (Node*) NULL; 2834 } 2835 } 2836 } 2837 constant_value = Klass::_lh_neutral_value; // put in a known value 2838 Node* lhp = basic_plus_adr(klass_node, klass_node, Klass::layout_helper_offset_in_bytes() + sizeof(oopDesc)); 2839 return make_load(NULL, lhp, TypeInt::INT, T_INT); 2840 } 2841 2842 // We just put in an allocate/initialize with a big raw-memory effect. 2843 // Hook selected additional alias categories on the initialization. 2844 static void hook_memory_on_init(GraphKit& kit, int alias_idx, 2845 MergeMemNode* init_in_merge, 2846 Node* init_out_raw) { 2847 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory()); 2848 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, ""); 2849 2850 Node* prevmem = kit.memory(alias_idx); 2851 init_in_merge->set_memory_at(alias_idx, prevmem); 2852 kit.set_memory(init_out_raw, alias_idx); 2853 } 2854 2855 //---------------------------set_output_for_allocation------------------------- 2856 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc, 2857 const TypeOopPtr* oop_type, 2858 bool raw_mem_only) { 2859 int rawidx = Compile::AliasIdxRaw; 2860 alloc->set_req( TypeFunc::FramePtr, frameptr() ); 2861 add_safepoint_edges(alloc); 2862 Node* allocx = _gvn.transform(alloc); 2863 set_control( _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Control) ) ); 2864 // create memory projection for i_o 2865 set_memory ( _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx ); 2866 make_slow_call_ex(allocx, env()->OutOfMemoryError_klass(), true); 2867 2868 // create a memory projection as for the normal control path 2869 Node* malloc = _gvn.transform(new (C, 1) ProjNode(allocx, TypeFunc::Memory)); 2870 set_memory(malloc, rawidx); 2871 2872 // a normal slow-call doesn't change i_o, but an allocation does 2873 // we create a separate i_o projection for the normal control path 2874 set_i_o(_gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::I_O, false) ) ); 2875 Node* rawoop = _gvn.transform( new (C, 1) ProjNode(allocx, TypeFunc::Parms) ); 2876 2877 // put in an initialization barrier 2878 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx, 2879 rawoop)->as_Initialize(); 2880 assert(alloc->initialization() == init, "2-way macro link must work"); 2881 assert(init ->allocation() == alloc, "2-way macro link must work"); 2882 if (ReduceFieldZeroing && !raw_mem_only) { 2883 // Extract memory strands which may participate in the new object's 2884 // initialization, and source them from the new InitializeNode. 2885 // This will allow us to observe initializations when they occur, 2886 // and link them properly (as a group) to the InitializeNode. 2887 assert(init->in(InitializeNode::Memory) == malloc, ""); 2888 MergeMemNode* minit_in = MergeMemNode::make(C, malloc); 2889 init->set_req(InitializeNode::Memory, minit_in); 2890 record_for_igvn(minit_in); // fold it up later, if possible 2891 Node* minit_out = memory(rawidx); 2892 assert(minit_out->is_Proj() && minit_out->in(0) == init, ""); 2893 if (oop_type->isa_aryptr()) { 2894 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot); 2895 int elemidx = C->get_alias_index(telemref); 2896 hook_memory_on_init(*this, elemidx, minit_in, minit_out); 2897 } else if (oop_type->isa_instptr()) { 2898 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass(); 2899 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) { 2900 ciField* field = ik->nonstatic_field_at(i); 2901 if (field->offset() >= TrackedInitializationLimit * HeapWordSize) 2902 continue; // do not bother to track really large numbers of fields 2903 // Find (or create) the alias category for this field: 2904 int fieldidx = C->alias_type(field)->index(); 2905 hook_memory_on_init(*this, fieldidx, minit_in, minit_out); 2906 } 2907 } 2908 } 2909 2910 // Cast raw oop to the real thing... 2911 Node* javaoop = new (C, 2) CheckCastPPNode(control(), rawoop, oop_type); 2912 javaoop = _gvn.transform(javaoop); 2913 C->set_recent_alloc(control(), javaoop); 2914 assert(just_allocated_object(control()) == javaoop, "just allocated"); 2915 2916 #ifdef ASSERT 2917 { // Verify that the AllocateNode::Ideal_allocation recognizers work: 2918 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc, 2919 "Ideal_allocation works"); 2920 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc, 2921 "Ideal_allocation works"); 2922 if (alloc->is_AllocateArray()) { 2923 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(), 2924 "Ideal_allocation works"); 2925 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(), 2926 "Ideal_allocation works"); 2927 } else { 2928 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please"); 2929 } 2930 } 2931 #endif //ASSERT 2932 2933 return javaoop; 2934 } 2935 2936 //---------------------------new_instance-------------------------------------- 2937 // This routine takes a klass_node which may be constant (for a static type) 2938 // or may be non-constant (for reflective code). It will work equally well 2939 // for either, and the graph will fold nicely if the optimizer later reduces 2940 // the type to a constant. 2941 // The optional arguments are for specialized use by intrinsics: 2942 // - If 'extra_slow_test' if not null is an extra condition for the slow-path. 2943 // - If 'raw_mem_only', do not cast the result to an oop. 2944 // - If 'return_size_val', report the the total object size to the caller. 2945 Node* GraphKit::new_instance(Node* klass_node, 2946 Node* extra_slow_test, 2947 bool raw_mem_only, // affect only raw memory 2948 Node* *return_size_val) { 2949 // Compute size in doublewords 2950 // The size is always an integral number of doublewords, represented 2951 // as a positive bytewise size stored in the klass's layout_helper. 2952 // The layout_helper also encodes (in a low bit) the need for a slow path. 2953 jint layout_con = Klass::_lh_neutral_value; 2954 Node* layout_val = get_layout_helper(klass_node, layout_con); 2955 int layout_is_con = (layout_val == NULL); 2956 2957 if (extra_slow_test == NULL) extra_slow_test = intcon(0); 2958 // Generate the initial go-slow test. It's either ALWAYS (return a 2959 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective 2960 // case) a computed value derived from the layout_helper. 2961 Node* initial_slow_test = NULL; 2962 if (layout_is_con) { 2963 assert(!StressReflectiveCode, "stress mode does not use these paths"); 2964 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con); 2965 initial_slow_test = must_go_slow? intcon(1): extra_slow_test; 2966 2967 } else { // reflective case 2968 // This reflective path is used by Unsafe.allocateInstance. 2969 // (It may be stress-tested by specifying StressReflectiveCode.) 2970 // Basically, we want to get into the VM is there's an illegal argument. 2971 Node* bit = intcon(Klass::_lh_instance_slow_path_bit); 2972 initial_slow_test = _gvn.transform( new (C, 3) AndINode(layout_val, bit) ); 2973 if (extra_slow_test != intcon(0)) { 2974 initial_slow_test = _gvn.transform( new (C, 3) OrINode(initial_slow_test, extra_slow_test) ); 2975 } 2976 // (Macro-expander will further convert this to a Bool, if necessary.) 2977 } 2978 2979 // Find the size in bytes. This is easy; it's the layout_helper. 2980 // The size value must be valid even if the slow path is taken. 2981 Node* size = NULL; 2982 if (layout_is_con) { 2983 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con)); 2984 } else { // reflective case 2985 // This reflective path is used by clone and Unsafe.allocateInstance. 2986 size = ConvI2X(layout_val); 2987 2988 // Clear the low bits to extract layout_helper_size_in_bytes: 2989 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit"); 2990 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong)); 2991 size = _gvn.transform( new (C, 3) AndXNode(size, mask) ); 2992 } 2993 if (return_size_val != NULL) { 2994 (*return_size_val) = size; 2995 } 2996 2997 // This is a precise notnull oop of the klass. 2998 // (Actually, it need not be precise if this is a reflective allocation.) 2999 // It's what we cast the result to. 3000 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr(); 3001 if (!tklass) tklass = TypeKlassPtr::OBJECT; 3002 const TypeOopPtr* oop_type = tklass->as_instance_type(); 3003 3004 // Now generate allocation code 3005 3006 // The entire memory state is needed for slow path of the allocation 3007 // since GC and deoptimization can happened. 3008 Node *mem = reset_memory(); 3009 set_all_memory(mem); // Create new memory state 3010 3011 AllocateNode* alloc 3012 = new (C, AllocateNode::ParmLimit) 3013 AllocateNode(C, AllocateNode::alloc_type(), 3014 control(), mem, i_o(), 3015 size, klass_node, 3016 initial_slow_test); 3017 3018 return set_output_for_allocation(alloc, oop_type, raw_mem_only); 3019 } 3020 3021 //-------------------------------new_array------------------------------------- 3022 // helper for both newarray and anewarray 3023 // The 'length' parameter is (obviously) the length of the array. 3024 // See comments on new_instance for the meaning of the other arguments. 3025 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable) 3026 Node* length, // number of array elements 3027 int nargs, // number of arguments to push back for uncommon trap 3028 bool raw_mem_only, // affect only raw memory 3029 Node* *return_size_val) { 3030 jint layout_con = Klass::_lh_neutral_value; 3031 Node* layout_val = get_layout_helper(klass_node, layout_con); 3032 int layout_is_con = (layout_val == NULL); 3033 3034 if (!layout_is_con && !StressReflectiveCode && 3035 !too_many_traps(Deoptimization::Reason_class_check)) { 3036 // This is a reflective array creation site. 3037 // Optimistically assume that it is a subtype of Object[], 3038 // so that we can fold up all the address arithmetic. 3039 layout_con = Klass::array_layout_helper(T_OBJECT); 3040 Node* cmp_lh = _gvn.transform( new(C, 3) CmpINode(layout_val, intcon(layout_con)) ); 3041 Node* bol_lh = _gvn.transform( new(C, 2) BoolNode(cmp_lh, BoolTest::eq) ); 3042 { BuildCutout unless(this, bol_lh, PROB_MAX); 3043 _sp += nargs; 3044 uncommon_trap(Deoptimization::Reason_class_check, 3045 Deoptimization::Action_maybe_recompile); 3046 } 3047 layout_val = NULL; 3048 layout_is_con = true; 3049 } 3050 3051 // Generate the initial go-slow test. Make sure we do not overflow 3052 // if length is huge (near 2Gig) or negative! We do not need 3053 // exact double-words here, just a close approximation of needed 3054 // double-words. We can't add any offset or rounding bits, lest we 3055 // take a size -1 of bytes and make it positive. Use an unsigned 3056 // compare, so negative sizes look hugely positive. 3057 int fast_size_limit = FastAllocateSizeLimit; 3058 if (layout_is_con) { 3059 assert(!StressReflectiveCode, "stress mode does not use these paths"); 3060 // Increase the size limit if we have exact knowledge of array type. 3061 int log2_esize = Klass::layout_helper_log2_element_size(layout_con); 3062 fast_size_limit <<= (LogBytesPerLong - log2_esize); 3063 } 3064 3065 Node* initial_slow_cmp = _gvn.transform( new (C, 3) CmpUNode( length, intcon( fast_size_limit ) ) ); 3066 Node* initial_slow_test = _gvn.transform( new (C, 2) BoolNode( initial_slow_cmp, BoolTest::gt ) ); 3067 if (initial_slow_test->is_Bool()) { 3068 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick. 3069 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn); 3070 } 3071 3072 // --- Size Computation --- 3073 // array_size = round_to_heap(array_header + (length << elem_shift)); 3074 // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes) 3075 // and round_to(x, y) == ((x + y-1) & ~(y-1)) 3076 // The rounding mask is strength-reduced, if possible. 3077 int round_mask = MinObjAlignmentInBytes - 1; 3078 Node* header_size = NULL; 3079 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE); 3080 // (T_BYTE has the weakest alignment and size restrictions...) 3081 if (layout_is_con) { 3082 int hsize = Klass::layout_helper_header_size(layout_con); 3083 int eshift = Klass::layout_helper_log2_element_size(layout_con); 3084 BasicType etype = Klass::layout_helper_element_type(layout_con); 3085 if ((round_mask & ~right_n_bits(eshift)) == 0) 3086 round_mask = 0; // strength-reduce it if it goes away completely 3087 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded"); 3088 assert(header_size_min <= hsize, "generic minimum is smallest"); 3089 header_size_min = hsize; 3090 header_size = intcon(hsize + round_mask); 3091 } else { 3092 Node* hss = intcon(Klass::_lh_header_size_shift); 3093 Node* hsm = intcon(Klass::_lh_header_size_mask); 3094 Node* hsize = _gvn.transform( new(C, 3) URShiftINode(layout_val, hss) ); 3095 hsize = _gvn.transform( new(C, 3) AndINode(hsize, hsm) ); 3096 Node* mask = intcon(round_mask); 3097 header_size = _gvn.transform( new(C, 3) AddINode(hsize, mask) ); 3098 } 3099 3100 Node* elem_shift = NULL; 3101 if (layout_is_con) { 3102 int eshift = Klass::layout_helper_log2_element_size(layout_con); 3103 if (eshift != 0) 3104 elem_shift = intcon(eshift); 3105 } else { 3106 // There is no need to mask or shift this value. 3107 // The semantics of LShiftINode include an implicit mask to 0x1F. 3108 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place"); 3109 elem_shift = layout_val; 3110 } 3111 3112 // Transition to native address size for all offset calculations: 3113 Node* lengthx = ConvI2X(length); 3114 Node* headerx = ConvI2X(header_size); 3115 #ifdef _LP64 3116 { const TypeLong* tllen = _gvn.find_long_type(lengthx); 3117 if (tllen != NULL && tllen->_lo < 0) { 3118 // Add a manual constraint to a positive range. Cf. array_element_address. 3119 jlong size_max = arrayOopDesc::max_array_length(T_BYTE); 3120 if (size_max > tllen->_hi) size_max = tllen->_hi; 3121 const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin); 3122 lengthx = _gvn.transform( new (C, 2) ConvI2LNode(length, tlcon)); 3123 } 3124 } 3125 #endif 3126 3127 // Combine header size (plus rounding) and body size. Then round down. 3128 // This computation cannot overflow, because it is used only in two 3129 // places, one where the length is sharply limited, and the other 3130 // after a successful allocation. 3131 Node* abody = lengthx; 3132 if (elem_shift != NULL) 3133 abody = _gvn.transform( new(C, 3) LShiftXNode(lengthx, elem_shift) ); 3134 Node* size = _gvn.transform( new(C, 3) AddXNode(headerx, abody) ); 3135 if (round_mask != 0) { 3136 Node* mask = MakeConX(~round_mask); 3137 size = _gvn.transform( new(C, 3) AndXNode(size, mask) ); 3138 } 3139 // else if round_mask == 0, the size computation is self-rounding 3140 3141 if (return_size_val != NULL) { 3142 // This is the size 3143 (*return_size_val) = size; 3144 } 3145 3146 // Now generate allocation code 3147 3148 // The entire memory state is needed for slow path of the allocation 3149 // since GC and deoptimization can happened. 3150 Node *mem = reset_memory(); 3151 set_all_memory(mem); // Create new memory state 3152 3153 // Create the AllocateArrayNode and its result projections 3154 AllocateArrayNode* alloc 3155 = new (C, AllocateArrayNode::ParmLimit) 3156 AllocateArrayNode(C, AllocateArrayNode::alloc_type(), 3157 control(), mem, i_o(), 3158 size, klass_node, 3159 initial_slow_test, 3160 length); 3161 3162 // Cast to correct type. Note that the klass_node may be constant or not, 3163 // and in the latter case the actual array type will be inexact also. 3164 // (This happens via a non-constant argument to inline_native_newArray.) 3165 // In any case, the value of klass_node provides the desired array type. 3166 const TypeInt* length_type = _gvn.find_int_type(length); 3167 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type(); 3168 if (ary_type->isa_aryptr() && length_type != NULL) { 3169 // Try to get a better type than POS for the size 3170 ary_type = ary_type->is_aryptr()->cast_to_size(length_type); 3171 } 3172 3173 Node* javaoop = set_output_for_allocation(alloc, ary_type, raw_mem_only); 3174 3175 // Cast length on remaining path to be as narrow as possible 3176 if (map()->find_edge(length) >= 0) { 3177 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn); 3178 if (ccast != length) { 3179 _gvn.set_type_bottom(ccast); 3180 record_for_igvn(ccast); 3181 replace_in_map(length, ccast); 3182 } 3183 } 3184 3185 return javaoop; 3186 } 3187 3188 // The following "Ideal_foo" functions are placed here because they recognize 3189 // the graph shapes created by the functions immediately above. 3190 3191 //---------------------------Ideal_allocation---------------------------------- 3192 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode. 3193 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) { 3194 if (ptr == NULL) { // reduce dumb test in callers 3195 return NULL; 3196 } 3197 if (ptr->is_CheckCastPP()) { // strip a raw-to-oop cast 3198 ptr = ptr->in(1); 3199 if (ptr == NULL) return NULL; 3200 } 3201 if (ptr->is_Proj()) { 3202 Node* allo = ptr->in(0); 3203 if (allo != NULL && allo->is_Allocate()) { 3204 return allo->as_Allocate(); 3205 } 3206 } 3207 // Report failure to match. 3208 return NULL; 3209 } 3210 3211 // Fancy version which also strips off an offset (and reports it to caller). 3212 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase, 3213 intptr_t& offset) { 3214 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset); 3215 if (base == NULL) return NULL; 3216 return Ideal_allocation(base, phase); 3217 } 3218 3219 // Trace Initialize <- Proj[Parm] <- Allocate 3220 AllocateNode* InitializeNode::allocation() { 3221 Node* rawoop = in(InitializeNode::RawAddress); 3222 if (rawoop->is_Proj()) { 3223 Node* alloc = rawoop->in(0); 3224 if (alloc->is_Allocate()) { 3225 return alloc->as_Allocate(); 3226 } 3227 } 3228 return NULL; 3229 } 3230 3231 // Trace Allocate -> Proj[Parm] -> Initialize 3232 InitializeNode* AllocateNode::initialization() { 3233 ProjNode* rawoop = proj_out(AllocateNode::RawAddress); 3234 if (rawoop == NULL) return NULL; 3235 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) { 3236 Node* init = rawoop->fast_out(i); 3237 if (init->is_Initialize()) { 3238 assert(init->as_Initialize()->allocation() == this, "2-way link"); 3239 return init->as_Initialize(); 3240 } 3241 } 3242 return NULL; 3243 } 3244 3245 //----------------------------- store barriers ---------------------------- 3246 #define __ ideal. 3247 3248 void GraphKit::sync_kit(IdealKit& ideal) { 3249 // Final sync IdealKit and graphKit. 3250 __ drain_delay_transform(); 3251 set_all_memory(__ merged_memory()); 3252 set_control(__ ctrl()); 3253 } 3254 3255 // vanilla/CMS post barrier 3256 // Insert a write-barrier store. This is to let generational GC work; we have 3257 // to flag all oop-stores before the next GC point. 3258 void GraphKit::write_barrier_post(Node* oop_store, 3259 Node* obj, 3260 Node* adr, 3261 uint adr_idx, 3262 Node* val, 3263 bool use_precise) { 3264 // No store check needed if we're storing a NULL or an old object 3265 // (latter case is probably a string constant). The concurrent 3266 // mark sweep garbage collector, however, needs to have all nonNull 3267 // oop updates flagged via card-marks. 3268 if (val != NULL && val->is_Con()) { 3269 // must be either an oop or NULL 3270 const Type* t = val->bottom_type(); 3271 if (t == TypePtr::NULL_PTR || t == Type::TOP) 3272 // stores of null never (?) need barriers 3273 return; 3274 ciObject* con = t->is_oopptr()->const_oop(); 3275 if (con != NULL 3276 && con->is_perm() 3277 && Universe::heap()->can_elide_permanent_oop_store_barriers()) 3278 // no store barrier needed, because no old-to-new ref created 3279 return; 3280 } 3281 3282 if (use_ReduceInitialCardMarks() 3283 && obj == just_allocated_object(control())) { 3284 // We can skip marks on a freshly-allocated object in Eden. 3285 // Keep this code in sync with maybe_defer_card_mark() in runtime.cpp. 3286 // That routine informs GC to take appropriate compensating steps 3287 // so as to make this card-mark elision safe. 3288 return; 3289 } 3290 3291 if (!use_precise) { 3292 // All card marks for a (non-array) instance are in one place: 3293 adr = obj; 3294 } 3295 // (Else it's an array (or unknown), and we want more precise card marks.) 3296 assert(adr != NULL, ""); 3297 3298 IdealKit ideal(gvn(), control(), merged_memory(), true); 3299 3300 // Convert the pointer to an int prior to doing math on it 3301 Node* cast = __ CastPX(__ ctrl(), adr); 3302 3303 // Divide by card size 3304 assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef, 3305 "Only one we handle so far."); 3306 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) ); 3307 3308 // Combine card table base and card offset 3309 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset ); 3310 3311 // Get the alias_index for raw card-mark memory 3312 int adr_type = Compile::AliasIdxRaw; 3313 // Smash zero into card 3314 Node* zero = __ ConI(0); 3315 BasicType bt = T_BYTE; 3316 if( !UseConcMarkSweepGC ) { 3317 __ store(__ ctrl(), card_adr, zero, bt, adr_type); 3318 } else { 3319 // Specialized path for CM store barrier 3320 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type); 3321 } 3322 3323 // Final sync IdealKit and GraphKit. 3324 sync_kit(ideal); 3325 } 3326 3327 // G1 pre/post barriers 3328 void GraphKit::g1_write_barrier_pre(Node* obj, 3329 Node* adr, 3330 uint alias_idx, 3331 Node* val, 3332 const TypeOopPtr* val_type, 3333 BasicType bt) { 3334 IdealKit ideal(gvn(), control(), merged_memory(), true); 3335 3336 Node* tls = __ thread(); // ThreadLocalStorage 3337 3338 Node* no_ctrl = NULL; 3339 Node* no_base = __ top(); 3340 Node* zero = __ ConI(0); 3341 3342 float likely = PROB_LIKELY(0.999); 3343 float unlikely = PROB_UNLIKELY(0.999); 3344 3345 BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE; 3346 assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width"); 3347 3348 // Offsets into the thread 3349 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648 3350 PtrQueue::byte_offset_of_active()); 3351 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656 3352 PtrQueue::byte_offset_of_index()); 3353 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652 3354 PtrQueue::byte_offset_of_buf()); 3355 // Now the actual pointers into the thread 3356 3357 // set_control( ctl); 3358 3359 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset)); 3360 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); 3361 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); 3362 3363 // Now some of the values 3364 3365 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw); 3366 3367 // if (!marking) 3368 __ if_then(marking, BoolTest::ne, zero); { 3369 Node* index = __ load(__ ctrl(), index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw); 3370 3371 const Type* t1 = adr->bottom_type(); 3372 const Type* t2 = val->bottom_type(); 3373 3374 Node* orig = __ load(no_ctrl, adr, val_type, bt, alias_idx); 3375 // if (orig != NULL) 3376 __ if_then(orig, BoolTest::ne, null()); { 3377 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); 3378 3379 // load original value 3380 // alias_idx correct?? 3381 3382 // is the queue for this thread full? 3383 __ if_then(index, BoolTest::ne, zero, likely); { 3384 3385 // decrement the index 3386 Node* next_index = __ SubI(index, __ ConI(sizeof(intptr_t))); 3387 Node* next_indexX = next_index; 3388 #ifdef _LP64 3389 // We could refine the type for what it's worth 3390 // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue); 3391 next_indexX = _gvn.transform( new (C, 2) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) ); 3392 #endif 3393 3394 // Now get the buffer location we will log the original value into and store it 3395 Node *log_addr = __ AddP(no_base, buffer, next_indexX); 3396 __ store(__ ctrl(), log_addr, orig, T_OBJECT, Compile::AliasIdxRaw); 3397 3398 // update the index 3399 __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw); 3400 3401 } __ else_(); { 3402 3403 // logging buffer is full, call the runtime 3404 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type(); 3405 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", orig, tls); 3406 } __ end_if(); // (!index) 3407 } __ end_if(); // (orig != NULL) 3408 } __ end_if(); // (!marking) 3409 3410 // Final sync IdealKit and GraphKit. 3411 sync_kit(ideal); 3412 } 3413 3414 // 3415 // Update the card table and add card address to the queue 3416 // 3417 void GraphKit::g1_mark_card(IdealKit& ideal, 3418 Node* card_adr, 3419 Node* oop_store, 3420 uint oop_alias_idx, 3421 Node* index, 3422 Node* index_adr, 3423 Node* buffer, 3424 const TypeFunc* tf) { 3425 3426 Node* zero = __ ConI(0); 3427 Node* no_base = __ top(); 3428 BasicType card_bt = T_BYTE; 3429 // Smash zero into card. MUST BE ORDERED WRT TO STORE 3430 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw); 3431 3432 // Now do the queue work 3433 __ if_then(index, BoolTest::ne, zero); { 3434 3435 Node* next_index = __ SubI(index, __ ConI(sizeof(intptr_t))); 3436 Node* next_indexX = next_index; 3437 #ifdef _LP64 3438 // We could refine the type for what it's worth 3439 // const TypeLong* lidxtype = TypeLong::make(CONST64(0), get_size_from_queue); 3440 next_indexX = _gvn.transform( new (C, 2) ConvI2LNode(next_index, TypeLong::make(0, max_jlong, Type::WidenMax)) ); 3441 #endif // _LP64 3442 Node* log_addr = __ AddP(no_base, buffer, next_indexX); 3443 3444 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw); 3445 __ store(__ ctrl(), index_adr, next_index, T_INT, Compile::AliasIdxRaw); 3446 3447 } __ else_(); { 3448 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread()); 3449 } __ end_if(); 3450 3451 } 3452 3453 void GraphKit::g1_write_barrier_post(Node* oop_store, 3454 Node* obj, 3455 Node* adr, 3456 uint alias_idx, 3457 Node* val, 3458 BasicType bt, 3459 bool use_precise) { 3460 // If we are writing a NULL then we need no post barrier 3461 3462 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) { 3463 // Must be NULL 3464 const Type* t = val->bottom_type(); 3465 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL"); 3466 // No post barrier if writing NULLx 3467 return; 3468 } 3469 3470 if (!use_precise) { 3471 // All card marks for a (non-array) instance are in one place: 3472 adr = obj; 3473 } 3474 // (Else it's an array (or unknown), and we want more precise card marks.) 3475 assert(adr != NULL, ""); 3476 3477 IdealKit ideal(gvn(), control(), merged_memory(), true); 3478 3479 Node* tls = __ thread(); // ThreadLocalStorage 3480 3481 Node* no_ctrl = NULL; 3482 Node* no_base = __ top(); 3483 float likely = PROB_LIKELY(0.999); 3484 float unlikely = PROB_UNLIKELY(0.999); 3485 Node* zero = __ ConI(0); 3486 Node* zeroX = __ ConX(0); 3487 3488 // Get the alias_index for raw card-mark memory 3489 const TypePtr* card_type = TypeRawPtr::BOTTOM; 3490 3491 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type(); 3492 3493 // Offsets into the thread 3494 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() + 3495 PtrQueue::byte_offset_of_index()); 3496 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() + 3497 PtrQueue::byte_offset_of_buf()); 3498 3499 // Pointers into the thread 3500 3501 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); 3502 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); 3503 3504 // Now some values 3505 3506 Node* index = __ load(no_ctrl, index_adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw); 3507 Node* buffer = __ load(no_ctrl, buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); 3508 3509 3510 // Convert the store obj pointer to an int prior to doing math on it 3511 // Must use ctrl to prevent "integerized oop" existing across safepoint 3512 Node* cast = __ CastPX(__ ctrl(), adr); 3513 3514 // Divide pointer by card size 3515 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) ); 3516 3517 // Combine card table base and card offset 3518 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset ); 3519 3520 // If we know the value being stored does it cross regions? 3521 3522 if (val != NULL) { 3523 // Does the store cause us to cross regions? 3524 3525 // Should be able to do an unsigned compare of region_size instead of 3526 // and extra shift. Do we have an unsigned compare?? 3527 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes); 3528 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes)); 3529 3530 // if (xor_res == 0) same region so skip 3531 __ if_then(xor_res, BoolTest::ne, zeroX); { 3532 3533 // No barrier if we are storing a NULL 3534 __ if_then(val, BoolTest::ne, null(), unlikely); { 3535 3536 // Ok must mark the card if not already dirty 3537 3538 // load the original value of the card 3539 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw); 3540 3541 __ if_then(card_val, BoolTest::ne, zero); { 3542 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf); 3543 } __ end_if(); 3544 } __ end_if(); 3545 } __ end_if(); 3546 } else { 3547 // Object.clone() instrinsic uses this path. 3548 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf); 3549 } 3550 3551 // Final sync IdealKit and GraphKit. 3552 sync_kit(ideal); 3553 } 3554 #undef __