1 /* 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "compiler/compileLog.hpp" 27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp" 28 #include "gc_implementation/g1/heapRegion.hpp" 29 #include "gc_interface/collectedHeap.hpp" 30 #include "memory/barrierSet.hpp" 31 #include "memory/cardTableModRefBS.hpp" 32 #include "opto/addnode.hpp" 33 #include "opto/castnode.hpp" 34 #include "opto/convertnode.hpp" 35 #include "opto/graphKit.hpp" 36 #include "opto/idealKit.hpp" 37 #include "opto/intrinsicnode.hpp" 38 #include "opto/locknode.hpp" 39 #include "opto/machnode.hpp" 40 #include "opto/opaquenode.hpp" 41 #include "opto/parse.hpp" 42 #include "opto/rootnode.hpp" 43 #include "opto/runtime.hpp" 44 #include "runtime/deoptimization.hpp" 45 #include "runtime/sharedRuntime.hpp" 46 47 //----------------------------GraphKit----------------------------------------- 48 // Main utility constructor. 49 GraphKit::GraphKit(JVMState* jvms) 50 : Phase(Phase::Parser), 51 _env(C->env()), 52 _gvn(*C->initial_gvn()) 53 { 54 _exceptions = jvms->map()->next_exception(); 55 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL); 56 set_jvms(jvms); 57 } 58 59 // Private constructor for parser. 60 GraphKit::GraphKit() 61 : Phase(Phase::Parser), 62 _env(C->env()), 63 _gvn(*C->initial_gvn()) 64 { 65 _exceptions = NULL; 66 set_map(NULL); 67 debug_only(_sp = -99); 68 debug_only(set_bci(-99)); 69 } 70 71 72 73 //---------------------------clean_stack--------------------------------------- 74 // Clear away rubbish from the stack area of the JVM state. 75 // This destroys any arguments that may be waiting on the stack. 76 void GraphKit::clean_stack(int from_sp) { 77 SafePointNode* map = this->map(); 78 JVMState* jvms = this->jvms(); 79 int stk_size = jvms->stk_size(); 80 int stkoff = jvms->stkoff(); 81 Node* top = this->top(); 82 for (int i = from_sp; i < stk_size; i++) { 83 if (map->in(stkoff + i) != top) { 84 map->set_req(stkoff + i, top); 85 } 86 } 87 } 88 89 90 //--------------------------------sync_jvms----------------------------------- 91 // Make sure our current jvms agrees with our parse state. 92 JVMState* GraphKit::sync_jvms() const { 93 JVMState* jvms = this->jvms(); 94 jvms->set_bci(bci()); // Record the new bci in the JVMState 95 jvms->set_sp(sp()); // Record the new sp in the JVMState 96 assert(jvms_in_sync(), "jvms is now in sync"); 97 return jvms; 98 } 99 100 //--------------------------------sync_jvms_for_reexecute--------------------- 101 // Make sure our current jvms agrees with our parse state. This version 102 // uses the reexecute_sp for reexecuting bytecodes. 103 JVMState* GraphKit::sync_jvms_for_reexecute() { 104 JVMState* jvms = this->jvms(); 105 jvms->set_bci(bci()); // Record the new bci in the JVMState 106 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState 107 return jvms; 108 } 109 110 #ifdef ASSERT 111 bool GraphKit::jvms_in_sync() const { 112 Parse* parse = is_Parse(); 113 if (parse == NULL) { 114 if (bci() != jvms()->bci()) return false; 115 if (sp() != (int)jvms()->sp()) return false; 116 return true; 117 } 118 if (jvms()->method() != parse->method()) return false; 119 if (jvms()->bci() != parse->bci()) return false; 120 int jvms_sp = jvms()->sp(); 121 if (jvms_sp != parse->sp()) return false; 122 int jvms_depth = jvms()->depth(); 123 if (jvms_depth != parse->depth()) return false; 124 return true; 125 } 126 127 // Local helper checks for special internal merge points 128 // used to accumulate and merge exception states. 129 // They are marked by the region's in(0) edge being the map itself. 130 // Such merge points must never "escape" into the parser at large, 131 // until they have been handed to gvn.transform. 132 static bool is_hidden_merge(Node* reg) { 133 if (reg == NULL) return false; 134 if (reg->is_Phi()) { 135 reg = reg->in(0); 136 if (reg == NULL) return false; 137 } 138 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root(); 139 } 140 141 void GraphKit::verify_map() const { 142 if (map() == NULL) return; // null map is OK 143 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map"); 144 assert(!map()->has_exceptions(), "call add_exception_states_from 1st"); 145 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map"); 146 } 147 148 void GraphKit::verify_exception_state(SafePointNode* ex_map) { 149 assert(ex_map->next_exception() == NULL, "not already part of a chain"); 150 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop"); 151 } 152 #endif 153 154 //---------------------------stop_and_kill_map--------------------------------- 155 // Set _map to NULL, signalling a stop to further bytecode execution. 156 // First smash the current map's control to a constant, to mark it dead. 157 void GraphKit::stop_and_kill_map() { 158 SafePointNode* dead_map = stop(); 159 if (dead_map != NULL) { 160 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed. 161 assert(dead_map->is_killed(), "must be so marked"); 162 } 163 } 164 165 166 //--------------------------------stopped-------------------------------------- 167 // Tell if _map is NULL, or control is top. 168 bool GraphKit::stopped() { 169 if (map() == NULL) return true; 170 else if (control() == top()) return true; 171 else return false; 172 } 173 174 175 //-----------------------------has_ex_handler---------------------------------- 176 // Tell if this method or any caller method has exception handlers. 177 bool GraphKit::has_ex_handler() { 178 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) { 179 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) { 180 return true; 181 } 182 } 183 return false; 184 } 185 186 //------------------------------save_ex_oop------------------------------------ 187 // Save an exception without blowing stack contents or other JVM state. 188 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) { 189 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again"); 190 ex_map->add_req(ex_oop); 191 debug_only(verify_exception_state(ex_map)); 192 } 193 194 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) { 195 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there"); 196 Node* ex_oop = ex_map->in(ex_map->req()-1); 197 if (clear_it) ex_map->del_req(ex_map->req()-1); 198 return ex_oop; 199 } 200 201 //-----------------------------saved_ex_oop------------------------------------ 202 // Recover a saved exception from its map. 203 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) { 204 return common_saved_ex_oop(ex_map, false); 205 } 206 207 //--------------------------clear_saved_ex_oop--------------------------------- 208 // Erase a previously saved exception from its map. 209 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) { 210 return common_saved_ex_oop(ex_map, true); 211 } 212 213 #ifdef ASSERT 214 //---------------------------has_saved_ex_oop---------------------------------- 215 // Erase a previously saved exception from its map. 216 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) { 217 return ex_map->req() == ex_map->jvms()->endoff()+1; 218 } 219 #endif 220 221 //-------------------------make_exception_state-------------------------------- 222 // Turn the current JVM state into an exception state, appending the ex_oop. 223 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) { 224 sync_jvms(); 225 SafePointNode* ex_map = stop(); // do not manipulate this map any more 226 set_saved_ex_oop(ex_map, ex_oop); 227 return ex_map; 228 } 229 230 231 //--------------------------add_exception_state-------------------------------- 232 // Add an exception to my list of exceptions. 233 void GraphKit::add_exception_state(SafePointNode* ex_map) { 234 if (ex_map == NULL || ex_map->control() == top()) { 235 return; 236 } 237 #ifdef ASSERT 238 verify_exception_state(ex_map); 239 if (has_exceptions()) { 240 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place"); 241 } 242 #endif 243 244 // If there is already an exception of exactly this type, merge with it. 245 // In particular, null-checks and other low-level exceptions common up here. 246 Node* ex_oop = saved_ex_oop(ex_map); 247 const Type* ex_type = _gvn.type(ex_oop); 248 if (ex_oop == top()) { 249 // No action needed. 250 return; 251 } 252 assert(ex_type->isa_instptr(), "exception must be an instance"); 253 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) { 254 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2)); 255 // We check sp also because call bytecodes can generate exceptions 256 // both before and after arguments are popped! 257 if (ex_type2 == ex_type 258 && e2->_jvms->sp() == ex_map->_jvms->sp()) { 259 combine_exception_states(ex_map, e2); 260 return; 261 } 262 } 263 264 // No pre-existing exception of the same type. Chain it on the list. 265 push_exception_state(ex_map); 266 } 267 268 //-----------------------add_exception_states_from----------------------------- 269 void GraphKit::add_exception_states_from(JVMState* jvms) { 270 SafePointNode* ex_map = jvms->map()->next_exception(); 271 if (ex_map != NULL) { 272 jvms->map()->set_next_exception(NULL); 273 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) { 274 next_map = ex_map->next_exception(); 275 ex_map->set_next_exception(NULL); 276 add_exception_state(ex_map); 277 } 278 } 279 } 280 281 //-----------------------transfer_exceptions_into_jvms------------------------- 282 JVMState* GraphKit::transfer_exceptions_into_jvms() { 283 if (map() == NULL) { 284 // We need a JVMS to carry the exceptions, but the map has gone away. 285 // Create a scratch JVMS, cloned from any of the exception states... 286 if (has_exceptions()) { 287 _map = _exceptions; 288 _map = clone_map(); 289 _map->set_next_exception(NULL); 290 clear_saved_ex_oop(_map); 291 debug_only(verify_map()); 292 } else { 293 // ...or created from scratch 294 JVMState* jvms = new (C) JVMState(_method, NULL); 295 jvms->set_bci(_bci); 296 jvms->set_sp(_sp); 297 jvms->set_map(new (C) SafePointNode(TypeFunc::Parms, jvms)); 298 set_jvms(jvms); 299 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top()); 300 set_all_memory(top()); 301 while (map()->req() < jvms->endoff()) map()->add_req(top()); 302 } 303 // (This is a kludge, in case you didn't notice.) 304 set_control(top()); 305 } 306 JVMState* jvms = sync_jvms(); 307 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet"); 308 jvms->map()->set_next_exception(_exceptions); 309 _exceptions = NULL; // done with this set of exceptions 310 return jvms; 311 } 312 313 static inline void add_n_reqs(Node* dstphi, Node* srcphi) { 314 assert(is_hidden_merge(dstphi), "must be a special merge node"); 315 assert(is_hidden_merge(srcphi), "must be a special merge node"); 316 uint limit = srcphi->req(); 317 for (uint i = PhiNode::Input; i < limit; i++) { 318 dstphi->add_req(srcphi->in(i)); 319 } 320 } 321 static inline void add_one_req(Node* dstphi, Node* src) { 322 assert(is_hidden_merge(dstphi), "must be a special merge node"); 323 assert(!is_hidden_merge(src), "must not be a special merge node"); 324 dstphi->add_req(src); 325 } 326 327 //-----------------------combine_exception_states------------------------------ 328 // This helper function combines exception states by building phis on a 329 // specially marked state-merging region. These regions and phis are 330 // untransformed, and can build up gradually. The region is marked by 331 // having a control input of its exception map, rather than NULL. Such 332 // regions do not appear except in this function, and in use_exception_state. 333 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) { 334 if (failing()) return; // dying anyway... 335 JVMState* ex_jvms = ex_map->_jvms; 336 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains"); 337 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals"); 338 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes"); 339 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS"); 340 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects"); 341 assert(ex_map->req() == phi_map->req(), "matching maps"); 342 uint tos = ex_jvms->stkoff() + ex_jvms->sp(); 343 Node* hidden_merge_mark = root(); 344 Node* region = phi_map->control(); 345 MergeMemNode* phi_mem = phi_map->merged_memory(); 346 MergeMemNode* ex_mem = ex_map->merged_memory(); 347 if (region->in(0) != hidden_merge_mark) { 348 // The control input is not (yet) a specially-marked region in phi_map. 349 // Make it so, and build some phis. 350 region = new (C) RegionNode(2); 351 _gvn.set_type(region, Type::CONTROL); 352 region->set_req(0, hidden_merge_mark); // marks an internal ex-state 353 region->init_req(1, phi_map->control()); 354 phi_map->set_control(region); 355 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO); 356 record_for_igvn(io_phi); 357 _gvn.set_type(io_phi, Type::ABIO); 358 phi_map->set_i_o(io_phi); 359 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) { 360 Node* m = mms.memory(); 361 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C)); 362 record_for_igvn(m_phi); 363 _gvn.set_type(m_phi, Type::MEMORY); 364 mms.set_memory(m_phi); 365 } 366 } 367 368 // Either or both of phi_map and ex_map might already be converted into phis. 369 Node* ex_control = ex_map->control(); 370 // if there is special marking on ex_map also, we add multiple edges from src 371 bool add_multiple = (ex_control->in(0) == hidden_merge_mark); 372 // how wide was the destination phi_map, originally? 373 uint orig_width = region->req(); 374 375 if (add_multiple) { 376 add_n_reqs(region, ex_control); 377 add_n_reqs(phi_map->i_o(), ex_map->i_o()); 378 } else { 379 // ex_map has no merges, so we just add single edges everywhere 380 add_one_req(region, ex_control); 381 add_one_req(phi_map->i_o(), ex_map->i_o()); 382 } 383 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) { 384 if (mms.is_empty()) { 385 // get a copy of the base memory, and patch some inputs into it 386 const TypePtr* adr_type = mms.adr_type(C); 387 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type); 388 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), ""); 389 mms.set_memory(phi); 390 // Prepare to append interesting stuff onto the newly sliced phi: 391 while (phi->req() > orig_width) phi->del_req(phi->req()-1); 392 } 393 // Append stuff from ex_map: 394 if (add_multiple) { 395 add_n_reqs(mms.memory(), mms.memory2()); 396 } else { 397 add_one_req(mms.memory(), mms.memory2()); 398 } 399 } 400 uint limit = ex_map->req(); 401 for (uint i = TypeFunc::Parms; i < limit; i++) { 402 // Skip everything in the JVMS after tos. (The ex_oop follows.) 403 if (i == tos) i = ex_jvms->monoff(); 404 Node* src = ex_map->in(i); 405 Node* dst = phi_map->in(i); 406 if (src != dst) { 407 PhiNode* phi; 408 if (dst->in(0) != region) { 409 dst = phi = PhiNode::make(region, dst, _gvn.type(dst)); 410 record_for_igvn(phi); 411 _gvn.set_type(phi, phi->type()); 412 phi_map->set_req(i, dst); 413 // Prepare to append interesting stuff onto the new phi: 414 while (dst->req() > orig_width) dst->del_req(dst->req()-1); 415 } else { 416 assert(dst->is_Phi(), "nobody else uses a hidden region"); 417 phi = dst->as_Phi(); 418 } 419 if (add_multiple && src->in(0) == ex_control) { 420 // Both are phis. 421 add_n_reqs(dst, src); 422 } else { 423 while (dst->req() < region->req()) add_one_req(dst, src); 424 } 425 const Type* srctype = _gvn.type(src); 426 if (phi->type() != srctype) { 427 const Type* dsttype = phi->type()->meet_speculative(srctype); 428 if (phi->type() != dsttype) { 429 phi->set_type(dsttype); 430 _gvn.set_type(phi, dsttype); 431 } 432 } 433 } 434 } 435 } 436 437 //--------------------------use_exception_state-------------------------------- 438 Node* GraphKit::use_exception_state(SafePointNode* phi_map) { 439 if (failing()) { stop(); return top(); } 440 Node* region = phi_map->control(); 441 Node* hidden_merge_mark = root(); 442 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation"); 443 Node* ex_oop = clear_saved_ex_oop(phi_map); 444 if (region->in(0) == hidden_merge_mark) { 445 // Special marking for internal ex-states. Process the phis now. 446 region->set_req(0, region); // now it's an ordinary region 447 set_jvms(phi_map->jvms()); // ...so now we can use it as a map 448 // Note: Setting the jvms also sets the bci and sp. 449 set_control(_gvn.transform(region)); 450 uint tos = jvms()->stkoff() + sp(); 451 for (uint i = 1; i < tos; i++) { 452 Node* x = phi_map->in(i); 453 if (x->in(0) == region) { 454 assert(x->is_Phi(), "expected a special phi"); 455 phi_map->set_req(i, _gvn.transform(x)); 456 } 457 } 458 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) { 459 Node* x = mms.memory(); 460 if (x->in(0) == region) { 461 assert(x->is_Phi(), "nobody else uses a hidden region"); 462 mms.set_memory(_gvn.transform(x)); 463 } 464 } 465 if (ex_oop->in(0) == region) { 466 assert(ex_oop->is_Phi(), "expected a special phi"); 467 ex_oop = _gvn.transform(ex_oop); 468 } 469 } else { 470 set_jvms(phi_map->jvms()); 471 } 472 473 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared"); 474 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared"); 475 return ex_oop; 476 } 477 478 //---------------------------------java_bc------------------------------------- 479 Bytecodes::Code GraphKit::java_bc() const { 480 ciMethod* method = this->method(); 481 int bci = this->bci(); 482 if (method != NULL && bci != InvocationEntryBci) 483 return method->java_code_at_bci(bci); 484 else 485 return Bytecodes::_illegal; 486 } 487 488 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason, 489 bool must_throw) { 490 // if the exception capability is set, then we will generate code 491 // to check the JavaThread.should_post_on_exceptions flag to see 492 // if we actually need to report exception events (for this 493 // thread). If we don't need to report exception events, we will 494 // take the normal fast path provided by add_exception_events. If 495 // exception event reporting is enabled for this thread, we will 496 // take the uncommon_trap in the BuildCutout below. 497 498 // first must access the should_post_on_exceptions_flag in this thread's JavaThread 499 Node* jthread = _gvn.transform(new (C) ThreadLocalNode()); 500 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset())); 501 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered); 502 503 // Test the should_post_on_exceptions_flag vs. 0 504 Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) ); 505 Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) ); 506 507 // Branch to slow_path if should_post_on_exceptions_flag was true 508 { BuildCutout unless(this, tst, PROB_MAX); 509 // Do not try anything fancy if we're notifying the VM on every throw. 510 // Cf. case Bytecodes::_athrow in parse2.cpp. 511 uncommon_trap(reason, Deoptimization::Action_none, 512 (ciKlass*)NULL, (char*)NULL, must_throw); 513 } 514 515 } 516 517 //------------------------------builtin_throw---------------------------------- 518 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) { 519 bool must_throw = true; 520 521 if (env()->jvmti_can_post_on_exceptions()) { 522 // check if we must post exception events, take uncommon trap if so 523 uncommon_trap_if_should_post_on_exceptions(reason, must_throw); 524 // here if should_post_on_exceptions is false 525 // continue on with the normal codegen 526 } 527 528 // If this particular condition has not yet happened at this 529 // bytecode, then use the uncommon trap mechanism, and allow for 530 // a future recompilation if several traps occur here. 531 // If the throw is hot, try to use a more complicated inline mechanism 532 // which keeps execution inside the compiled code. 533 bool treat_throw_as_hot = false; 534 ciMethodData* md = method()->method_data(); 535 536 if (ProfileTraps) { 537 if (too_many_traps(reason)) { 538 treat_throw_as_hot = true; 539 } 540 // (If there is no MDO at all, assume it is early in 541 // execution, and that any deopts are part of the 542 // startup transient, and don't need to be remembered.) 543 544 // Also, if there is a local exception handler, treat all throws 545 // as hot if there has been at least one in this method. 546 if (C->trap_count(reason) != 0 547 && method()->method_data()->trap_count(reason) != 0 548 && has_ex_handler()) { 549 treat_throw_as_hot = true; 550 } 551 } 552 553 // If this throw happens frequently, an uncommon trap might cause 554 // a performance pothole. If there is a local exception handler, 555 // and if this particular bytecode appears to be deoptimizing often, 556 // let us handle the throw inline, with a preconstructed instance. 557 // Note: If the deopt count has blown up, the uncommon trap 558 // runtime is going to flush this nmethod, not matter what. 559 if (treat_throw_as_hot 560 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) { 561 // If the throw is local, we use a pre-existing instance and 562 // punt on the backtrace. This would lead to a missing backtrace 563 // (a repeat of 4292742) if the backtrace object is ever asked 564 // for its backtrace. 565 // Fixing this remaining case of 4292742 requires some flavor of 566 // escape analysis. Leave that for the future. 567 ciInstance* ex_obj = NULL; 568 switch (reason) { 569 case Deoptimization::Reason_null_check: 570 ex_obj = env()->NullPointerException_instance(); 571 break; 572 case Deoptimization::Reason_div0_check: 573 ex_obj = env()->ArithmeticException_instance(); 574 break; 575 case Deoptimization::Reason_range_check: 576 ex_obj = env()->ArrayIndexOutOfBoundsException_instance(); 577 break; 578 case Deoptimization::Reason_class_check: 579 if (java_bc() == Bytecodes::_aastore) { 580 ex_obj = env()->ArrayStoreException_instance(); 581 } else { 582 ex_obj = env()->ClassCastException_instance(); 583 } 584 break; 585 } 586 if (failing()) { stop(); return; } // exception allocation might fail 587 if (ex_obj != NULL) { 588 // Cheat with a preallocated exception object. 589 if (C->log() != NULL) 590 C->log()->elem("hot_throw preallocated='1' reason='%s'", 591 Deoptimization::trap_reason_name(reason)); 592 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj); 593 Node* ex_node = _gvn.transform( ConNode::make(C, ex_con) ); 594 595 // Clear the detail message of the preallocated exception object. 596 // Weblogic sometimes mutates the detail message of exceptions 597 // using reflection. 598 int offset = java_lang_Throwable::get_detailMessage_offset(); 599 const TypePtr* adr_typ = ex_con->add_offset(offset); 600 601 Node *adr = basic_plus_adr(ex_node, ex_node, offset); 602 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass()); 603 // Conservatively release stores of object references. 604 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release); 605 606 add_exception_state(make_exception_state(ex_node)); 607 return; 608 } 609 } 610 611 // %%% Maybe add entry to OptoRuntime which directly throws the exc.? 612 // It won't be much cheaper than bailing to the interp., since we'll 613 // have to pass up all the debug-info, and the runtime will have to 614 // create the stack trace. 615 616 // Usual case: Bail to interpreter. 617 // Reserve the right to recompile if we haven't seen anything yet. 618 619 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL; 620 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile; 621 if (treat_throw_as_hot 622 && (method()->method_data()->trap_recompiled_at(bci(), m) 623 || C->too_many_traps(reason))) { 624 // We cannot afford to take more traps here. Suffer in the interpreter. 625 if (C->log() != NULL) 626 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'", 627 Deoptimization::trap_reason_name(reason), 628 C->trap_count(reason)); 629 action = Deoptimization::Action_none; 630 } 631 632 // "must_throw" prunes the JVM state to include only the stack, if there 633 // are no local exception handlers. This should cut down on register 634 // allocation time and code size, by drastically reducing the number 635 // of in-edges on the call to the uncommon trap. 636 637 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw); 638 } 639 640 641 //----------------------------PreserveJVMState--------------------------------- 642 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) { 643 debug_only(kit->verify_map()); 644 _kit = kit; 645 _map = kit->map(); // preserve the map 646 _sp = kit->sp(); 647 kit->set_map(clone_map ? kit->clone_map() : NULL); 648 Compile::current()->inc_preserve_jvm_state(); 649 #ifdef ASSERT 650 _bci = kit->bci(); 651 Parse* parser = kit->is_Parse(); 652 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo(); 653 _block = block; 654 #endif 655 } 656 PreserveJVMState::~PreserveJVMState() { 657 GraphKit* kit = _kit; 658 #ifdef ASSERT 659 assert(kit->bci() == _bci, "bci must not shift"); 660 Parse* parser = kit->is_Parse(); 661 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo(); 662 assert(block == _block, "block must not shift"); 663 #endif 664 kit->set_map(_map); 665 kit->set_sp(_sp); 666 Compile::current()->dec_preserve_jvm_state(); 667 } 668 669 670 //-----------------------------BuildCutout------------------------------------- 671 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt) 672 : PreserveJVMState(kit) 673 { 674 assert(p->is_Con() || p->is_Bool(), "test must be a bool"); 675 SafePointNode* outer_map = _map; // preserved map is caller's 676 SafePointNode* inner_map = kit->map(); 677 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt); 678 outer_map->set_control(kit->gvn().transform( new (kit->C) IfTrueNode(iff) )); 679 inner_map->set_control(kit->gvn().transform( new (kit->C) IfFalseNode(iff) )); 680 } 681 BuildCutout::~BuildCutout() { 682 GraphKit* kit = _kit; 683 assert(kit->stopped(), "cutout code must stop, throw, return, etc."); 684 } 685 686 //---------------------------PreserveReexecuteState---------------------------- 687 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) { 688 assert(!kit->stopped(), "must call stopped() before"); 689 _kit = kit; 690 _sp = kit->sp(); 691 _reexecute = kit->jvms()->_reexecute; 692 } 693 PreserveReexecuteState::~PreserveReexecuteState() { 694 if (_kit->stopped()) return; 695 _kit->jvms()->_reexecute = _reexecute; 696 _kit->set_sp(_sp); 697 } 698 699 //------------------------------clone_map-------------------------------------- 700 // Implementation of PreserveJVMState 701 // 702 // Only clone_map(...) here. If this function is only used in the 703 // PreserveJVMState class we may want to get rid of this extra 704 // function eventually and do it all there. 705 706 SafePointNode* GraphKit::clone_map() { 707 if (map() == NULL) return NULL; 708 709 // Clone the memory edge first 710 Node* mem = MergeMemNode::make(C, map()->memory()); 711 gvn().set_type_bottom(mem); 712 713 SafePointNode *clonemap = (SafePointNode*)map()->clone(); 714 JVMState* jvms = this->jvms(); 715 JVMState* clonejvms = jvms->clone_shallow(C); 716 clonemap->set_memory(mem); 717 clonemap->set_jvms(clonejvms); 718 clonejvms->set_map(clonemap); 719 record_for_igvn(clonemap); 720 gvn().set_type_bottom(clonemap); 721 return clonemap; 722 } 723 724 725 //-----------------------------set_map_clone----------------------------------- 726 void GraphKit::set_map_clone(SafePointNode* m) { 727 _map = m; 728 _map = clone_map(); 729 _map->set_next_exception(NULL); 730 debug_only(verify_map()); 731 } 732 733 734 //----------------------------kill_dead_locals--------------------------------- 735 // Detect any locals which are known to be dead, and force them to top. 736 void GraphKit::kill_dead_locals() { 737 // Consult the liveness information for the locals. If any 738 // of them are unused, then they can be replaced by top(). This 739 // should help register allocation time and cut down on the size 740 // of the deoptimization information. 741 742 // This call is made from many of the bytecode handling 743 // subroutines called from the Big Switch in do_one_bytecode. 744 // Every bytecode which might include a slow path is responsible 745 // for killing its dead locals. The more consistent we 746 // are about killing deads, the fewer useless phis will be 747 // constructed for them at various merge points. 748 749 // bci can be -1 (InvocationEntryBci). We return the entry 750 // liveness for the method. 751 752 if (method() == NULL || method()->code_size() == 0) { 753 // We are building a graph for a call to a native method. 754 // All locals are live. 755 return; 756 } 757 758 ResourceMark rm; 759 760 // Consult the liveness information for the locals. If any 761 // of them are unused, then they can be replaced by top(). This 762 // should help register allocation time and cut down on the size 763 // of the deoptimization information. 764 MethodLivenessResult live_locals = method()->liveness_at_bci(bci()); 765 766 int len = (int)live_locals.size(); 767 assert(len <= jvms()->loc_size(), "too many live locals"); 768 for (int local = 0; local < len; local++) { 769 if (!live_locals.at(local)) { 770 set_local(local, top()); 771 } 772 } 773 } 774 775 #ifdef ASSERT 776 //-------------------------dead_locals_are_killed------------------------------ 777 // Return true if all dead locals are set to top in the map. 778 // Used to assert "clean" debug info at various points. 779 bool GraphKit::dead_locals_are_killed() { 780 if (method() == NULL || method()->code_size() == 0) { 781 // No locals need to be dead, so all is as it should be. 782 return true; 783 } 784 785 // Make sure somebody called kill_dead_locals upstream. 786 ResourceMark rm; 787 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) { 788 if (jvms->loc_size() == 0) continue; // no locals to consult 789 SafePointNode* map = jvms->map(); 790 ciMethod* method = jvms->method(); 791 int bci = jvms->bci(); 792 if (jvms == this->jvms()) { 793 bci = this->bci(); // it might not yet be synched 794 } 795 MethodLivenessResult live_locals = method->liveness_at_bci(bci); 796 int len = (int)live_locals.size(); 797 if (!live_locals.is_valid() || len == 0) 798 // This method is trivial, or is poisoned by a breakpoint. 799 return true; 800 assert(len == jvms->loc_size(), "live map consistent with locals map"); 801 for (int local = 0; local < len; local++) { 802 if (!live_locals.at(local) && map->local(jvms, local) != top()) { 803 if (PrintMiscellaneous && (Verbose || WizardMode)) { 804 tty->print_cr("Zombie local %d: ", local); 805 jvms->dump(); 806 } 807 return false; 808 } 809 } 810 } 811 return true; 812 } 813 814 #endif //ASSERT 815 816 // Helper function for enforcing certain bytecodes to reexecute if 817 // deoptimization happens 818 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) { 819 ciMethod* cur_method = jvms->method(); 820 int cur_bci = jvms->bci(); 821 if (cur_method != NULL && cur_bci != InvocationEntryBci) { 822 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci); 823 return Interpreter::bytecode_should_reexecute(code) || 824 is_anewarray && code == Bytecodes::_multianewarray; 825 // Reexecute _multianewarray bytecode which was replaced with 826 // sequence of [a]newarray. See Parse::do_multianewarray(). 827 // 828 // Note: interpreter should not have it set since this optimization 829 // is limited by dimensions and guarded by flag so in some cases 830 // multianewarray() runtime calls will be generated and 831 // the bytecode should not be reexecutes (stack will not be reset). 832 } else 833 return false; 834 } 835 836 // Helper function for adding JVMState and debug information to node 837 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) { 838 // Add the safepoint edges to the call (or other safepoint). 839 840 // Make sure dead locals are set to top. This 841 // should help register allocation time and cut down on the size 842 // of the deoptimization information. 843 assert(dead_locals_are_killed(), "garbage in debug info before safepoint"); 844 845 // Walk the inline list to fill in the correct set of JVMState's 846 // Also fill in the associated edges for each JVMState. 847 848 // If the bytecode needs to be reexecuted we need to put 849 // the arguments back on the stack. 850 const bool should_reexecute = jvms()->should_reexecute(); 851 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms(); 852 853 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to 854 // undefined if the bci is different. This is normal for Parse but it 855 // should not happen for LibraryCallKit because only one bci is processed. 856 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute), 857 "in LibraryCallKit the reexecute bit should not change"); 858 859 // If we are guaranteed to throw, we can prune everything but the 860 // input to the current bytecode. 861 bool can_prune_locals = false; 862 uint stack_slots_not_pruned = 0; 863 int inputs = 0, depth = 0; 864 if (must_throw) { 865 assert(method() == youngest_jvms->method(), "sanity"); 866 if (compute_stack_effects(inputs, depth)) { 867 can_prune_locals = true; 868 stack_slots_not_pruned = inputs; 869 } 870 } 871 872 if (env()->should_retain_local_variables()) { 873 // At any safepoint, this method can get breakpointed, which would 874 // then require an immediate deoptimization. 875 can_prune_locals = false; // do not prune locals 876 stack_slots_not_pruned = 0; 877 } 878 879 // do not scribble on the input jvms 880 JVMState* out_jvms = youngest_jvms->clone_deep(C); 881 call->set_jvms(out_jvms); // Start jvms list for call node 882 883 // For a known set of bytecodes, the interpreter should reexecute them if 884 // deoptimization happens. We set the reexecute state for them here 885 if (out_jvms->is_reexecute_undefined() && //don't change if already specified 886 should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) { 887 out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed 888 } 889 890 // Presize the call: 891 DEBUG_ONLY(uint non_debug_edges = call->req()); 892 call->add_req_batch(top(), youngest_jvms->debug_depth()); 893 assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), ""); 894 895 // Set up edges so that the call looks like this: 896 // Call [state:] ctl io mem fptr retadr 897 // [parms:] parm0 ... parmN 898 // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN 899 // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...] 900 // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN 901 // Note that caller debug info precedes callee debug info. 902 903 // Fill pointer walks backwards from "young:" to "root:" in the diagram above: 904 uint debug_ptr = call->req(); 905 906 // Loop over the map input edges associated with jvms, add them 907 // to the call node, & reset all offsets to match call node array. 908 for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) { 909 uint debug_end = debug_ptr; 910 uint debug_start = debug_ptr - in_jvms->debug_size(); 911 debug_ptr = debug_start; // back up the ptr 912 913 uint p = debug_start; // walks forward in [debug_start, debug_end) 914 uint j, k, l; 915 SafePointNode* in_map = in_jvms->map(); 916 out_jvms->set_map(call); 917 918 if (can_prune_locals) { 919 assert(in_jvms->method() == out_jvms->method(), "sanity"); 920 // If the current throw can reach an exception handler in this JVMS, 921 // then we must keep everything live that can reach that handler. 922 // As a quick and dirty approximation, we look for any handlers at all. 923 if (in_jvms->method()->has_exception_handlers()) { 924 can_prune_locals = false; 925 } 926 } 927 928 // Add the Locals 929 k = in_jvms->locoff(); 930 l = in_jvms->loc_size(); 931 out_jvms->set_locoff(p); 932 if (!can_prune_locals) { 933 for (j = 0; j < l; j++) 934 call->set_req(p++, in_map->in(k+j)); 935 } else { 936 p += l; // already set to top above by add_req_batch 937 } 938 939 // Add the Expression Stack 940 k = in_jvms->stkoff(); 941 l = in_jvms->sp(); 942 out_jvms->set_stkoff(p); 943 if (!can_prune_locals) { 944 for (j = 0; j < l; j++) 945 call->set_req(p++, in_map->in(k+j)); 946 } else if (can_prune_locals && stack_slots_not_pruned != 0) { 947 // Divide stack into {S0,...,S1}, where S0 is set to top. 948 uint s1 = stack_slots_not_pruned; 949 stack_slots_not_pruned = 0; // for next iteration 950 if (s1 > l) s1 = l; 951 uint s0 = l - s1; 952 p += s0; // skip the tops preinstalled by add_req_batch 953 for (j = s0; j < l; j++) 954 call->set_req(p++, in_map->in(k+j)); 955 } else { 956 p += l; // already set to top above by add_req_batch 957 } 958 959 // Add the Monitors 960 k = in_jvms->monoff(); 961 l = in_jvms->mon_size(); 962 out_jvms->set_monoff(p); 963 for (j = 0; j < l; j++) 964 call->set_req(p++, in_map->in(k+j)); 965 966 // Copy any scalar object fields. 967 k = in_jvms->scloff(); 968 l = in_jvms->scl_size(); 969 out_jvms->set_scloff(p); 970 for (j = 0; j < l; j++) 971 call->set_req(p++, in_map->in(k+j)); 972 973 // Finish the new jvms. 974 out_jvms->set_endoff(p); 975 976 assert(out_jvms->endoff() == debug_end, "fill ptr must match"); 977 assert(out_jvms->depth() == in_jvms->depth(), "depth must match"); 978 assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match"); 979 assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match"); 980 assert(out_jvms->scl_size() == in_jvms->scl_size(), "size must match"); 981 assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match"); 982 983 // Update the two tail pointers in parallel. 984 out_jvms = out_jvms->caller(); 985 in_jvms = in_jvms->caller(); 986 } 987 988 assert(debug_ptr == non_debug_edges, "debug info must fit exactly"); 989 990 // Test the correctness of JVMState::debug_xxx accessors: 991 assert(call->jvms()->debug_start() == non_debug_edges, ""); 992 assert(call->jvms()->debug_end() == call->req(), ""); 993 assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, ""); 994 } 995 996 bool GraphKit::compute_stack_effects(int& inputs, int& depth) { 997 Bytecodes::Code code = java_bc(); 998 if (code == Bytecodes::_wide) { 999 code = method()->java_code_at_bci(bci() + 1); 1000 } 1001 1002 BasicType rtype = T_ILLEGAL; 1003 int rsize = 0; 1004 1005 if (code != Bytecodes::_illegal) { 1006 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1 1007 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V 1008 if (rtype < T_CONFLICT) 1009 rsize = type2size[rtype]; 1010 } 1011 1012 switch (code) { 1013 case Bytecodes::_illegal: 1014 return false; 1015 1016 case Bytecodes::_ldc: 1017 case Bytecodes::_ldc_w: 1018 case Bytecodes::_ldc2_w: 1019 inputs = 0; 1020 break; 1021 1022 case Bytecodes::_dup: inputs = 1; break; 1023 case Bytecodes::_dup_x1: inputs = 2; break; 1024 case Bytecodes::_dup_x2: inputs = 3; break; 1025 case Bytecodes::_dup2: inputs = 2; break; 1026 case Bytecodes::_dup2_x1: inputs = 3; break; 1027 case Bytecodes::_dup2_x2: inputs = 4; break; 1028 case Bytecodes::_swap: inputs = 2; break; 1029 case Bytecodes::_arraylength: inputs = 1; break; 1030 1031 case Bytecodes::_getstatic: 1032 case Bytecodes::_putstatic: 1033 case Bytecodes::_getfield: 1034 case Bytecodes::_putfield: 1035 { 1036 bool ignored_will_link; 1037 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link); 1038 int size = field->type()->size(); 1039 bool is_get = (depth >= 0), is_static = (depth & 1); 1040 inputs = (is_static ? 0 : 1); 1041 if (is_get) { 1042 depth = size - inputs; 1043 } else { 1044 inputs += size; // putxxx pops the value from the stack 1045 depth = - inputs; 1046 } 1047 } 1048 break; 1049 1050 case Bytecodes::_invokevirtual: 1051 case Bytecodes::_invokespecial: 1052 case Bytecodes::_invokestatic: 1053 case Bytecodes::_invokedynamic: 1054 case Bytecodes::_invokeinterface: 1055 { 1056 bool ignored_will_link; 1057 ciSignature* declared_signature = NULL; 1058 ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature); 1059 assert(declared_signature != NULL, "cannot be null"); 1060 inputs = declared_signature->arg_size_for_bc(code); 1061 int size = declared_signature->return_type()->size(); 1062 depth = size - inputs; 1063 } 1064 break; 1065 1066 case Bytecodes::_multianewarray: 1067 { 1068 ciBytecodeStream iter(method()); 1069 iter.reset_to_bci(bci()); 1070 iter.next(); 1071 inputs = iter.get_dimensions(); 1072 assert(rsize == 1, ""); 1073 depth = rsize - inputs; 1074 } 1075 break; 1076 1077 case Bytecodes::_ireturn: 1078 case Bytecodes::_lreturn: 1079 case Bytecodes::_freturn: 1080 case Bytecodes::_dreturn: 1081 case Bytecodes::_areturn: 1082 assert(rsize = -depth, ""); 1083 inputs = rsize; 1084 break; 1085 1086 case Bytecodes::_jsr: 1087 case Bytecodes::_jsr_w: 1088 inputs = 0; 1089 depth = 1; // S.B. depth=1, not zero 1090 break; 1091 1092 default: 1093 // bytecode produces a typed result 1094 inputs = rsize - depth; 1095 assert(inputs >= 0, ""); 1096 break; 1097 } 1098 1099 #ifdef ASSERT 1100 // spot check 1101 int outputs = depth + inputs; 1102 assert(outputs >= 0, "sanity"); 1103 switch (code) { 1104 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break; 1105 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break; 1106 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break; 1107 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break; 1108 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break; 1109 } 1110 #endif //ASSERT 1111 1112 return true; 1113 } 1114 1115 1116 1117 //------------------------------basic_plus_adr--------------------------------- 1118 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) { 1119 // short-circuit a common case 1120 if (offset == intcon(0)) return ptr; 1121 return _gvn.transform( new (C) AddPNode(base, ptr, offset) ); 1122 } 1123 1124 Node* GraphKit::ConvI2L(Node* offset) { 1125 // short-circuit a common case 1126 jint offset_con = find_int_con(offset, Type::OffsetBot); 1127 if (offset_con != Type::OffsetBot) { 1128 return longcon((jlong) offset_con); 1129 } 1130 return _gvn.transform( new (C) ConvI2LNode(offset)); 1131 } 1132 1133 Node* GraphKit::ConvI2UL(Node* offset) { 1134 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot); 1135 if (offset_con != (juint) Type::OffsetBot) { 1136 return longcon((julong) offset_con); 1137 } 1138 Node* conv = _gvn.transform( new (C) ConvI2LNode(offset)); 1139 Node* mask = _gvn.transform( ConLNode::make(C, (julong) max_juint) ); 1140 return _gvn.transform( new (C) AndLNode(conv, mask) ); 1141 } 1142 1143 Node* GraphKit::ConvL2I(Node* offset) { 1144 // short-circuit a common case 1145 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot); 1146 if (offset_con != (jlong)Type::OffsetBot) { 1147 return intcon((int) offset_con); 1148 } 1149 return _gvn.transform( new (C) ConvL2INode(offset)); 1150 } 1151 1152 //-------------------------load_object_klass----------------------------------- 1153 Node* GraphKit::load_object_klass(Node* obj) { 1154 // Special-case a fresh allocation to avoid building nodes: 1155 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn); 1156 if (akls != NULL) return akls; 1157 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes()); 1158 return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) ); 1159 } 1160 1161 //-------------------------load_array_length----------------------------------- 1162 Node* GraphKit::load_array_length(Node* array) { 1163 // Special-case a fresh allocation to avoid building nodes: 1164 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn); 1165 Node *alen; 1166 if (alloc == NULL) { 1167 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes()); 1168 alen = _gvn.transform( new (C) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS)); 1169 } else { 1170 alen = alloc->Ideal_length(); 1171 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn); 1172 if (ccast != alen) { 1173 alen = _gvn.transform(ccast); 1174 } 1175 } 1176 return alen; 1177 } 1178 1179 //------------------------------do_null_check---------------------------------- 1180 // Helper function to do a NULL pointer check. Returned value is 1181 // the incoming address with NULL casted away. You are allowed to use the 1182 // not-null value only if you are control dependent on the test. 1183 extern int explicit_null_checks_inserted, 1184 explicit_null_checks_elided; 1185 Node* GraphKit::null_check_common(Node* value, BasicType type, 1186 // optional arguments for variations: 1187 bool assert_null, 1188 Node* *null_control, 1189 bool speculative) { 1190 assert(!assert_null || null_control == NULL, "not both at once"); 1191 if (stopped()) return top(); 1192 if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) { 1193 // For some performance testing, we may wish to suppress null checking. 1194 value = cast_not_null(value); // Make it appear to be non-null (4962416). 1195 return value; 1196 } 1197 explicit_null_checks_inserted++; 1198 1199 // Construct NULL check 1200 Node *chk = NULL; 1201 switch(type) { 1202 case T_LONG : chk = new (C) CmpLNode(value, _gvn.zerocon(T_LONG)); break; 1203 case T_INT : chk = new (C) CmpINode(value, _gvn.intcon(0)); break; 1204 case T_ARRAY : // fall through 1205 type = T_OBJECT; // simplify further tests 1206 case T_OBJECT : { 1207 const Type *t = _gvn.type( value ); 1208 1209 const TypeOopPtr* tp = t->isa_oopptr(); 1210 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded() 1211 // Only for do_null_check, not any of its siblings: 1212 && !assert_null && null_control == NULL) { 1213 // Usually, any field access or invocation on an unloaded oop type 1214 // will simply fail to link, since the statically linked class is 1215 // likely also to be unloaded. However, in -Xcomp mode, sometimes 1216 // the static class is loaded but the sharper oop type is not. 1217 // Rather than checking for this obscure case in lots of places, 1218 // we simply observe that a null check on an unloaded class 1219 // will always be followed by a nonsense operation, so we 1220 // can just issue the uncommon trap here. 1221 // Our access to the unloaded class will only be correct 1222 // after it has been loaded and initialized, which requires 1223 // a trip through the interpreter. 1224 #ifndef PRODUCT 1225 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); } 1226 #endif 1227 uncommon_trap(Deoptimization::Reason_unloaded, 1228 Deoptimization::Action_reinterpret, 1229 tp->klass(), "!loaded"); 1230 return top(); 1231 } 1232 1233 if (assert_null) { 1234 // See if the type is contained in NULL_PTR. 1235 // If so, then the value is already null. 1236 if (t->higher_equal(TypePtr::NULL_PTR)) { 1237 explicit_null_checks_elided++; 1238 return value; // Elided null assert quickly! 1239 } 1240 } else { 1241 // See if mixing in the NULL pointer changes type. 1242 // If so, then the NULL pointer was not allowed in the original 1243 // type. In other words, "value" was not-null. 1244 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) { 1245 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ... 1246 explicit_null_checks_elided++; 1247 return value; // Elided null check quickly! 1248 } 1249 } 1250 chk = new (C) CmpPNode( value, null() ); 1251 break; 1252 } 1253 1254 default: 1255 fatal(err_msg_res("unexpected type: %s", type2name(type))); 1256 } 1257 assert(chk != NULL, "sanity check"); 1258 chk = _gvn.transform(chk); 1259 1260 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne; 1261 BoolNode *btst = new (C) BoolNode( chk, btest); 1262 Node *tst = _gvn.transform( btst ); 1263 1264 //----------- 1265 // if peephole optimizations occurred, a prior test existed. 1266 // If a prior test existed, maybe it dominates as we can avoid this test. 1267 if (tst != btst && type == T_OBJECT) { 1268 // At this point we want to scan up the CFG to see if we can 1269 // find an identical test (and so avoid this test altogether). 1270 Node *cfg = control(); 1271 int depth = 0; 1272 while( depth < 16 ) { // Limit search depth for speed 1273 if( cfg->Opcode() == Op_IfTrue && 1274 cfg->in(0)->in(1) == tst ) { 1275 // Found prior test. Use "cast_not_null" to construct an identical 1276 // CastPP (and hence hash to) as already exists for the prior test. 1277 // Return that casted value. 1278 if (assert_null) { 1279 replace_in_map(value, null()); 1280 return null(); // do not issue the redundant test 1281 } 1282 Node *oldcontrol = control(); 1283 set_control(cfg); 1284 Node *res = cast_not_null(value); 1285 set_control(oldcontrol); 1286 explicit_null_checks_elided++; 1287 return res; 1288 } 1289 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true); 1290 if (cfg == NULL) break; // Quit at region nodes 1291 depth++; 1292 } 1293 } 1294 1295 //----------- 1296 // Branch to failure if null 1297 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen 1298 Deoptimization::DeoptReason reason; 1299 if (assert_null) { 1300 reason = Deoptimization::Reason_null_assert; 1301 } else if (type == T_OBJECT) { 1302 reason = Deoptimization::reason_null_check(speculative); 1303 } else { 1304 reason = Deoptimization::Reason_div0_check; 1305 } 1306 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis, 1307 // ciMethodData::has_trap_at will return a conservative -1 if any 1308 // must-be-null assertion has failed. This could cause performance 1309 // problems for a method after its first do_null_assert failure. 1310 // Consider using 'Reason_class_check' instead? 1311 1312 // To cause an implicit null check, we set the not-null probability 1313 // to the maximum (PROB_MAX). For an explicit check the probability 1314 // is set to a smaller value. 1315 if (null_control != NULL || too_many_traps(reason)) { 1316 // probability is less likely 1317 ok_prob = PROB_LIKELY_MAG(3); 1318 } else if (!assert_null && 1319 (ImplicitNullCheckThreshold > 0) && 1320 method() != NULL && 1321 (method()->method_data()->trap_count(reason) 1322 >= (uint)ImplicitNullCheckThreshold)) { 1323 ok_prob = PROB_LIKELY_MAG(3); 1324 } 1325 1326 if (null_control != NULL) { 1327 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN); 1328 Node* null_true = _gvn.transform( new (C) IfFalseNode(iff)); 1329 set_control( _gvn.transform( new (C) IfTrueNode(iff))); 1330 if (null_true == top()) 1331 explicit_null_checks_elided++; 1332 (*null_control) = null_true; 1333 } else { 1334 BuildCutout unless(this, tst, ok_prob); 1335 // Check for optimizer eliding test at parse time 1336 if (stopped()) { 1337 // Failure not possible; do not bother making uncommon trap. 1338 explicit_null_checks_elided++; 1339 } else if (assert_null) { 1340 uncommon_trap(reason, 1341 Deoptimization::Action_make_not_entrant, 1342 NULL, "assert_null"); 1343 } else { 1344 replace_in_map(value, zerocon(type)); 1345 builtin_throw(reason); 1346 } 1347 } 1348 1349 // Must throw exception, fall-thru not possible? 1350 if (stopped()) { 1351 return top(); // No result 1352 } 1353 1354 if (assert_null) { 1355 // Cast obj to null on this path. 1356 replace_in_map(value, zerocon(type)); 1357 return zerocon(type); 1358 } 1359 1360 // Cast obj to not-null on this path, if there is no null_control. 1361 // (If there is a null_control, a non-null value may come back to haunt us.) 1362 if (type == T_OBJECT) { 1363 Node* cast = cast_not_null(value, false); 1364 if (null_control == NULL || (*null_control) == top()) 1365 replace_in_map(value, cast); 1366 value = cast; 1367 } 1368 1369 return value; 1370 } 1371 1372 1373 //------------------------------cast_not_null---------------------------------- 1374 // Cast obj to not-null on this path 1375 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) { 1376 const Type *t = _gvn.type(obj); 1377 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL); 1378 // Object is already not-null? 1379 if( t == t_not_null ) return obj; 1380 1381 Node *cast = new (C) CastPPNode(obj,t_not_null); 1382 cast->init_req(0, control()); 1383 cast = _gvn.transform( cast ); 1384 1385 // Scan for instances of 'obj' in the current JVM mapping. 1386 // These instances are known to be not-null after the test. 1387 if (do_replace_in_map) 1388 replace_in_map(obj, cast); 1389 1390 return cast; // Return casted value 1391 } 1392 1393 1394 //--------------------------replace_in_map------------------------------------- 1395 void GraphKit::replace_in_map(Node* old, Node* neww) { 1396 if (old == neww) { 1397 return; 1398 } 1399 1400 map()->replace_edge(old, neww); 1401 1402 // Note: This operation potentially replaces any edge 1403 // on the map. This includes locals, stack, and monitors 1404 // of the current (innermost) JVM state. 1405 1406 if (!ReplaceInParentMaps) { 1407 return; 1408 } 1409 1410 // PreserveJVMState doesn't do a deep copy so we can't modify 1411 // parents 1412 if (Compile::current()->has_preserve_jvm_state()) { 1413 return; 1414 } 1415 1416 Parse* parser = is_Parse(); 1417 bool progress = true; 1418 Node* ctrl = map()->in(0); 1419 // Follow the chain of parsers and see whether the update can be 1420 // done in the map of callers. We can do the replace for a caller if 1421 // the current control post dominates the control of a caller. 1422 while (parser != NULL && parser->caller() != NULL && progress) { 1423 progress = false; 1424 Node* parent_map = parser->caller()->map(); 1425 assert(parser->exits().map()->jvms()->depth() == parser->caller()->depth(), "map mismatch"); 1426 1427 Node* parent_ctrl = parent_map->in(0); 1428 1429 while (parent_ctrl->is_Region()) { 1430 Node* n = parent_ctrl->as_Region()->is_copy(); 1431 if (n == NULL) { 1432 break; 1433 } 1434 parent_ctrl = n; 1435 } 1436 1437 for (;;) { 1438 if (ctrl == parent_ctrl) { 1439 // update the map of the exits which is the one that will be 1440 // used when compilation resume after inlining 1441 parser->exits().map()->replace_edge(old, neww); 1442 progress = true; 1443 break; 1444 } 1445 if (ctrl->is_Proj() && ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none)) { 1446 ctrl = ctrl->in(0)->in(0); 1447 } else if (ctrl->is_Region()) { 1448 Node* n = ctrl->as_Region()->is_copy(); 1449 if (n == NULL) { 1450 break; 1451 } 1452 ctrl = n; 1453 } else { 1454 break; 1455 } 1456 } 1457 1458 parser = parser->parent_parser(); 1459 } 1460 } 1461 1462 1463 //============================================================================= 1464 //--------------------------------memory--------------------------------------- 1465 Node* GraphKit::memory(uint alias_idx) { 1466 MergeMemNode* mem = merged_memory(); 1467 Node* p = mem->memory_at(alias_idx); 1468 _gvn.set_type(p, Type::MEMORY); // must be mapped 1469 return p; 1470 } 1471 1472 //-----------------------------reset_memory------------------------------------ 1473 Node* GraphKit::reset_memory() { 1474 Node* mem = map()->memory(); 1475 // do not use this node for any more parsing! 1476 debug_only( map()->set_memory((Node*)NULL) ); 1477 return _gvn.transform( mem ); 1478 } 1479 1480 //------------------------------set_all_memory--------------------------------- 1481 void GraphKit::set_all_memory(Node* newmem) { 1482 Node* mergemem = MergeMemNode::make(C, newmem); 1483 gvn().set_type_bottom(mergemem); 1484 map()->set_memory(mergemem); 1485 } 1486 1487 //------------------------------set_all_memory_call---------------------------- 1488 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) { 1489 Node* newmem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory, separate_io_proj) ); 1490 set_all_memory(newmem); 1491 } 1492 1493 //============================================================================= 1494 // 1495 // parser factory methods for MemNodes 1496 // 1497 // These are layered on top of the factory methods in LoadNode and StoreNode, 1498 // and integrate with the parser's memory state and _gvn engine. 1499 // 1500 1501 // factory methods in "int adr_idx" 1502 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt, 1503 int adr_idx, 1504 MemNode::MemOrd mo, bool require_atomic_access) { 1505 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" ); 1506 const TypePtr* adr_type = NULL; // debug-mode-only argument 1507 debug_only(adr_type = C->get_adr_type(adr_idx)); 1508 Node* mem = memory(adr_idx); 1509 Node* ld; 1510 if (require_atomic_access && bt == T_LONG) { 1511 ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo); 1512 } else { 1513 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo); 1514 } 1515 ld = _gvn.transform(ld); 1516 if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) { 1517 // Improve graph before escape analysis and boxing elimination. 1518 record_for_igvn(ld); 1519 } 1520 return ld; 1521 } 1522 1523 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt, 1524 int adr_idx, 1525 MemNode::MemOrd mo, 1526 bool require_atomic_access) { 1527 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 1528 const TypePtr* adr_type = NULL; 1529 debug_only(adr_type = C->get_adr_type(adr_idx)); 1530 Node *mem = memory(adr_idx); 1531 Node* st; 1532 if (require_atomic_access && bt == T_LONG) { 1533 st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo); 1534 } else { 1535 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo); 1536 } 1537 st = _gvn.transform(st); 1538 set_memory(st, adr_idx); 1539 // Back-to-back stores can only remove intermediate store with DU info 1540 // so push on worklist for optimizer. 1541 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address)) 1542 record_for_igvn(st); 1543 1544 return st; 1545 } 1546 1547 1548 void GraphKit::pre_barrier(bool do_load, 1549 Node* ctl, 1550 Node* obj, 1551 Node* adr, 1552 uint adr_idx, 1553 Node* val, 1554 const TypeOopPtr* val_type, 1555 Node* pre_val, 1556 BasicType bt) { 1557 1558 BarrierSet* bs = Universe::heap()->barrier_set(); 1559 set_control(ctl); 1560 switch (bs->kind()) { 1561 case BarrierSet::G1SATBCT: 1562 case BarrierSet::G1SATBCTLogging: 1563 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt); 1564 break; 1565 1566 case BarrierSet::CardTableModRef: 1567 case BarrierSet::CardTableExtension: 1568 case BarrierSet::ModRef: 1569 break; 1570 1571 case BarrierSet::Other: 1572 default : 1573 ShouldNotReachHere(); 1574 1575 } 1576 } 1577 1578 bool GraphKit::can_move_pre_barrier() const { 1579 BarrierSet* bs = Universe::heap()->barrier_set(); 1580 switch (bs->kind()) { 1581 case BarrierSet::G1SATBCT: 1582 case BarrierSet::G1SATBCTLogging: 1583 return true; // Can move it if no safepoint 1584 1585 case BarrierSet::CardTableModRef: 1586 case BarrierSet::CardTableExtension: 1587 case BarrierSet::ModRef: 1588 return true; // There is no pre-barrier 1589 1590 case BarrierSet::Other: 1591 default : 1592 ShouldNotReachHere(); 1593 } 1594 return false; 1595 } 1596 1597 void GraphKit::post_barrier(Node* ctl, 1598 Node* store, 1599 Node* obj, 1600 Node* adr, 1601 uint adr_idx, 1602 Node* val, 1603 BasicType bt, 1604 bool use_precise) { 1605 BarrierSet* bs = Universe::heap()->barrier_set(); 1606 set_control(ctl); 1607 switch (bs->kind()) { 1608 case BarrierSet::G1SATBCT: 1609 case BarrierSet::G1SATBCTLogging: 1610 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise); 1611 break; 1612 1613 case BarrierSet::CardTableModRef: 1614 case BarrierSet::CardTableExtension: 1615 write_barrier_post(store, obj, adr, adr_idx, val, use_precise); 1616 break; 1617 1618 case BarrierSet::ModRef: 1619 break; 1620 1621 case BarrierSet::Other: 1622 default : 1623 ShouldNotReachHere(); 1624 1625 } 1626 } 1627 1628 Node* GraphKit::store_oop(Node* ctl, 1629 Node* obj, 1630 Node* adr, 1631 const TypePtr* adr_type, 1632 Node* val, 1633 const TypeOopPtr* val_type, 1634 BasicType bt, 1635 bool use_precise, 1636 MemNode::MemOrd mo) { 1637 // Transformation of a value which could be NULL pointer (CastPP #NULL) 1638 // could be delayed during Parse (for example, in adjust_map_after_if()). 1639 // Execute transformation here to avoid barrier generation in such case. 1640 if (_gvn.type(val) == TypePtr::NULL_PTR) 1641 val = _gvn.makecon(TypePtr::NULL_PTR); 1642 1643 set_control(ctl); 1644 if (stopped()) return top(); // Dead path ? 1645 1646 assert(bt == T_OBJECT, "sanity"); 1647 assert(val != NULL, "not dead path"); 1648 uint adr_idx = C->get_alias_index(adr_type); 1649 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 1650 1651 pre_barrier(true /* do_load */, 1652 control(), obj, adr, adr_idx, val, val_type, 1653 NULL /* pre_val */, 1654 bt); 1655 1656 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo); 1657 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise); 1658 return store; 1659 } 1660 1661 // Could be an array or object we don't know at compile time (unsafe ref.) 1662 Node* GraphKit::store_oop_to_unknown(Node* ctl, 1663 Node* obj, // containing obj 1664 Node* adr, // actual adress to store val at 1665 const TypePtr* adr_type, 1666 Node* val, 1667 BasicType bt, 1668 MemNode::MemOrd mo) { 1669 Compile::AliasType* at = C->alias_type(adr_type); 1670 const TypeOopPtr* val_type = NULL; 1671 if (adr_type->isa_instptr()) { 1672 if (at->field() != NULL) { 1673 // known field. This code is a copy of the do_put_xxx logic. 1674 ciField* field = at->field(); 1675 if (!field->type()->is_loaded()) { 1676 val_type = TypeInstPtr::BOTTOM; 1677 } else { 1678 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass()); 1679 } 1680 } 1681 } else if (adr_type->isa_aryptr()) { 1682 val_type = adr_type->is_aryptr()->elem()->make_oopptr(); 1683 } 1684 if (val_type == NULL) { 1685 val_type = TypeInstPtr::BOTTOM; 1686 } 1687 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo); 1688 } 1689 1690 1691 //-------------------------array_element_address------------------------- 1692 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt, 1693 const TypeInt* sizetype) { 1694 uint shift = exact_log2(type2aelembytes(elembt)); 1695 uint header = arrayOopDesc::base_offset_in_bytes(elembt); 1696 1697 // short-circuit a common case (saves lots of confusing waste motion) 1698 jint idx_con = find_int_con(idx, -1); 1699 if (idx_con >= 0) { 1700 intptr_t offset = header + ((intptr_t)idx_con << shift); 1701 return basic_plus_adr(ary, offset); 1702 } 1703 1704 // must be correct type for alignment purposes 1705 Node* base = basic_plus_adr(ary, header); 1706 #ifdef _LP64 1707 // The scaled index operand to AddP must be a clean 64-bit value. 1708 // Java allows a 32-bit int to be incremented to a negative 1709 // value, which appears in a 64-bit register as a large 1710 // positive number. Using that large positive number as an 1711 // operand in pointer arithmetic has bad consequences. 1712 // On the other hand, 32-bit overflow is rare, and the possibility 1713 // can often be excluded, if we annotate the ConvI2L node with 1714 // a type assertion that its value is known to be a small positive 1715 // number. (The prior range check has ensured this.) 1716 // This assertion is used by ConvI2LNode::Ideal. 1717 int index_max = max_jint - 1; // array size is max_jint, index is one less 1718 if (sizetype != NULL) index_max = sizetype->_hi - 1; 1719 const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax); 1720 idx = _gvn.transform( new (C) ConvI2LNode(idx, lidxtype) ); 1721 #endif 1722 Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) ); 1723 return basic_plus_adr(ary, base, scale); 1724 } 1725 1726 //-------------------------load_array_element------------------------- 1727 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) { 1728 const Type* elemtype = arytype->elem(); 1729 BasicType elembt = elemtype->array_element_basic_type(); 1730 Node* adr = array_element_address(ary, idx, elembt, arytype->size()); 1731 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered); 1732 return ld; 1733 } 1734 1735 //-------------------------set_arguments_for_java_call------------------------- 1736 // Arguments (pre-popped from the stack) are taken from the JVMS. 1737 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) { 1738 // Add the call arguments: 1739 uint nargs = call->method()->arg_size(); 1740 for (uint i = 0; i < nargs; i++) { 1741 Node* arg = argument(i); 1742 call->init_req(i + TypeFunc::Parms, arg); 1743 } 1744 } 1745 1746 //---------------------------set_edges_for_java_call--------------------------- 1747 // Connect a newly created call into the current JVMS. 1748 // A return value node (if any) is returned from set_edges_for_java_call. 1749 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) { 1750 1751 // Add the predefined inputs: 1752 call->init_req( TypeFunc::Control, control() ); 1753 call->init_req( TypeFunc::I_O , i_o() ); 1754 call->init_req( TypeFunc::Memory , reset_memory() ); 1755 call->init_req( TypeFunc::FramePtr, frameptr() ); 1756 call->init_req( TypeFunc::ReturnAdr, top() ); 1757 1758 add_safepoint_edges(call, must_throw); 1759 1760 Node* xcall = _gvn.transform(call); 1761 1762 if (xcall == top()) { 1763 set_control(top()); 1764 return; 1765 } 1766 assert(xcall == call, "call identity is stable"); 1767 1768 // Re-use the current map to produce the result. 1769 1770 set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control))); 1771 set_i_o( _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O , separate_io_proj))); 1772 set_all_memory_call(xcall, separate_io_proj); 1773 1774 //return xcall; // no need, caller already has it 1775 } 1776 1777 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) { 1778 if (stopped()) return top(); // maybe the call folded up? 1779 1780 // Capture the return value, if any. 1781 Node* ret; 1782 if (call->method() == NULL || 1783 call->method()->return_type()->basic_type() == T_VOID) 1784 ret = top(); 1785 else ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms)); 1786 1787 // Note: Since any out-of-line call can produce an exception, 1788 // we always insert an I_O projection from the call into the result. 1789 1790 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj); 1791 1792 if (separate_io_proj) { 1793 // The caller requested separate projections be used by the fall 1794 // through and exceptional paths, so replace the projections for 1795 // the fall through path. 1796 set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) )); 1797 set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) )); 1798 } 1799 return ret; 1800 } 1801 1802 //--------------------set_predefined_input_for_runtime_call-------------------- 1803 // Reading and setting the memory state is way conservative here. 1804 // The real problem is that I am not doing real Type analysis on memory, 1805 // so I cannot distinguish card mark stores from other stores. Across a GC 1806 // point the Store Barrier and the card mark memory has to agree. I cannot 1807 // have a card mark store and its barrier split across the GC point from 1808 // either above or below. Here I get that to happen by reading ALL of memory. 1809 // A better answer would be to separate out card marks from other memory. 1810 // For now, return the input memory state, so that it can be reused 1811 // after the call, if this call has restricted memory effects. 1812 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) { 1813 // Set fixed predefined input arguments 1814 Node* memory = reset_memory(); 1815 call->init_req( TypeFunc::Control, control() ); 1816 call->init_req( TypeFunc::I_O, top() ); // does no i/o 1817 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs 1818 call->init_req( TypeFunc::FramePtr, frameptr() ); 1819 call->init_req( TypeFunc::ReturnAdr, top() ); 1820 return memory; 1821 } 1822 1823 //-------------------set_predefined_output_for_runtime_call-------------------- 1824 // Set control and memory (not i_o) from the call. 1825 // If keep_mem is not NULL, use it for the output state, 1826 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM. 1827 // If hook_mem is NULL, this call produces no memory effects at all. 1828 // If hook_mem is a Java-visible memory slice (such as arraycopy operands), 1829 // then only that memory slice is taken from the call. 1830 // In the last case, we must put an appropriate memory barrier before 1831 // the call, so as to create the correct anti-dependencies on loads 1832 // preceding the call. 1833 void GraphKit::set_predefined_output_for_runtime_call(Node* call, 1834 Node* keep_mem, 1835 const TypePtr* hook_mem) { 1836 // no i/o 1837 set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) )); 1838 if (keep_mem) { 1839 // First clone the existing memory state 1840 set_all_memory(keep_mem); 1841 if (hook_mem != NULL) { 1842 // Make memory for the call 1843 Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ); 1844 // Set the RawPtr memory state only. This covers all the heap top/GC stuff 1845 // We also use hook_mem to extract specific effects from arraycopy stubs. 1846 set_memory(mem, hook_mem); 1847 } 1848 // ...else the call has NO memory effects. 1849 1850 // Make sure the call advertises its memory effects precisely. 1851 // This lets us build accurate anti-dependences in gcm.cpp. 1852 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem), 1853 "call node must be constructed correctly"); 1854 } else { 1855 assert(hook_mem == NULL, ""); 1856 // This is not a "slow path" call; all memory comes from the call. 1857 set_all_memory_call(call); 1858 } 1859 } 1860 1861 1862 // Replace the call with the current state of the kit. 1863 void GraphKit::replace_call(CallNode* call, Node* result) { 1864 JVMState* ejvms = NULL; 1865 if (has_exceptions()) { 1866 ejvms = transfer_exceptions_into_jvms(); 1867 } 1868 1869 SafePointNode* final_state = stop(); 1870 1871 // Find all the needed outputs of this call 1872 CallProjections callprojs; 1873 call->extract_projections(&callprojs, true); 1874 1875 Node* init_mem = call->in(TypeFunc::Memory); 1876 Node* final_mem = final_state->in(TypeFunc::Memory); 1877 Node* final_ctl = final_state->in(TypeFunc::Control); 1878 Node* final_io = final_state->in(TypeFunc::I_O); 1879 1880 // Replace all the old call edges with the edges from the inlining result 1881 if (callprojs.fallthrough_catchproj != NULL) { 1882 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl); 1883 } 1884 if (callprojs.fallthrough_memproj != NULL) { 1885 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem); 1886 } 1887 if (callprojs.fallthrough_ioproj != NULL) { 1888 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io); 1889 } 1890 1891 // Replace the result with the new result if it exists and is used 1892 if (callprojs.resproj != NULL && result != NULL) { 1893 C->gvn_replace_by(callprojs.resproj, result); 1894 } 1895 1896 if (ejvms == NULL) { 1897 // No exception edges to simply kill off those paths 1898 if (callprojs.catchall_catchproj != NULL) { 1899 C->gvn_replace_by(callprojs.catchall_catchproj, C->top()); 1900 } 1901 if (callprojs.catchall_memproj != NULL) { 1902 C->gvn_replace_by(callprojs.catchall_memproj, C->top()); 1903 } 1904 if (callprojs.catchall_ioproj != NULL) { 1905 C->gvn_replace_by(callprojs.catchall_ioproj, C->top()); 1906 } 1907 // Replace the old exception object with top 1908 if (callprojs.exobj != NULL) { 1909 C->gvn_replace_by(callprojs.exobj, C->top()); 1910 } 1911 } else { 1912 GraphKit ekit(ejvms); 1913 1914 // Load my combined exception state into the kit, with all phis transformed: 1915 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states(); 1916 1917 Node* ex_oop = ekit.use_exception_state(ex_map); 1918 if (callprojs.catchall_catchproj != NULL) { 1919 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control()); 1920 } 1921 if (callprojs.catchall_memproj != NULL) { 1922 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory()); 1923 } 1924 if (callprojs.catchall_ioproj != NULL) { 1925 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o()); 1926 } 1927 1928 // Replace the old exception object with the newly created one 1929 if (callprojs.exobj != NULL) { 1930 C->gvn_replace_by(callprojs.exobj, ex_oop); 1931 } 1932 } 1933 1934 // Disconnect the call from the graph 1935 call->disconnect_inputs(NULL, C); 1936 C->gvn_replace_by(call, C->top()); 1937 1938 // Clean up any MergeMems that feed other MergeMems since the 1939 // optimizer doesn't like that. 1940 if (final_mem->is_MergeMem()) { 1941 Node_List wl; 1942 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) { 1943 Node* m = i.get(); 1944 if (m->is_MergeMem() && !wl.contains(m)) { 1945 wl.push(m); 1946 } 1947 } 1948 while (wl.size() > 0) { 1949 _gvn.transform(wl.pop()); 1950 } 1951 } 1952 } 1953 1954 1955 //------------------------------increment_counter------------------------------ 1956 // for statistics: increment a VM counter by 1 1957 1958 void GraphKit::increment_counter(address counter_addr) { 1959 Node* adr1 = makecon(TypeRawPtr::make(counter_addr)); 1960 increment_counter(adr1); 1961 } 1962 1963 void GraphKit::increment_counter(Node* counter_addr) { 1964 int adr_type = Compile::AliasIdxRaw; 1965 Node* ctrl = control(); 1966 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered); 1967 Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1))); 1968 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered); 1969 } 1970 1971 1972 //------------------------------uncommon_trap---------------------------------- 1973 // Bail out to the interpreter in mid-method. Implemented by calling the 1974 // uncommon_trap blob. This helper function inserts a runtime call with the 1975 // right debug info. 1976 void GraphKit::uncommon_trap(int trap_request, 1977 ciKlass* klass, const char* comment, 1978 bool must_throw, 1979 bool keep_exact_action) { 1980 if (failing()) stop(); 1981 if (stopped()) return; // trap reachable? 1982 1983 // Note: If ProfileTraps is true, and if a deopt. actually 1984 // occurs here, the runtime will make sure an MDO exists. There is 1985 // no need to call method()->ensure_method_data() at this point. 1986 1987 // Set the stack pointer to the right value for reexecution: 1988 set_sp(reexecute_sp()); 1989 1990 #ifdef ASSERT 1991 if (!must_throw) { 1992 // Make sure the stack has at least enough depth to execute 1993 // the current bytecode. 1994 int inputs, ignored_depth; 1995 if (compute_stack_effects(inputs, ignored_depth)) { 1996 assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d", 1997 Bytecodes::name(java_bc()), sp(), inputs)); 1998 } 1999 } 2000 #endif 2001 2002 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); 2003 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request); 2004 2005 switch (action) { 2006 case Deoptimization::Action_maybe_recompile: 2007 case Deoptimization::Action_reinterpret: 2008 // Temporary fix for 6529811 to allow virtual calls to be sure they 2009 // get the chance to go from mono->bi->mega 2010 if (!keep_exact_action && 2011 Deoptimization::trap_request_index(trap_request) < 0 && 2012 too_many_recompiles(reason)) { 2013 // This BCI is causing too many recompilations. 2014 action = Deoptimization::Action_none; 2015 trap_request = Deoptimization::make_trap_request(reason, action); 2016 } else { 2017 C->set_trap_can_recompile(true); 2018 } 2019 break; 2020 case Deoptimization::Action_make_not_entrant: 2021 C->set_trap_can_recompile(true); 2022 break; 2023 #ifdef ASSERT 2024 case Deoptimization::Action_none: 2025 case Deoptimization::Action_make_not_compilable: 2026 break; 2027 default: 2028 fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action))); 2029 break; 2030 #endif 2031 } 2032 2033 if (TraceOptoParse) { 2034 char buf[100]; 2035 tty->print_cr("Uncommon trap %s at bci:%d", 2036 Deoptimization::format_trap_request(buf, sizeof(buf), 2037 trap_request), bci()); 2038 } 2039 2040 CompileLog* log = C->log(); 2041 if (log != NULL) { 2042 int kid = (klass == NULL)? -1: log->identify(klass); 2043 log->begin_elem("uncommon_trap bci='%d'", bci()); 2044 char buf[100]; 2045 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf), 2046 trap_request)); 2047 if (kid >= 0) log->print(" klass='%d'", kid); 2048 if (comment != NULL) log->print(" comment='%s'", comment); 2049 log->end_elem(); 2050 } 2051 2052 // Make sure any guarding test views this path as very unlikely 2053 Node *i0 = control()->in(0); 2054 if (i0 != NULL && i0->is_If()) { // Found a guarding if test? 2055 IfNode *iff = i0->as_If(); 2056 float f = iff->_prob; // Get prob 2057 if (control()->Opcode() == Op_IfTrue) { 2058 if (f > PROB_UNLIKELY_MAG(4)) 2059 iff->_prob = PROB_MIN; 2060 } else { 2061 if (f < PROB_LIKELY_MAG(4)) 2062 iff->_prob = PROB_MAX; 2063 } 2064 } 2065 2066 // Clear out dead values from the debug info. 2067 kill_dead_locals(); 2068 2069 // Now insert the uncommon trap subroutine call 2070 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point(); 2071 const TypePtr* no_memory_effects = NULL; 2072 // Pass the index of the class to be loaded 2073 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON | 2074 (must_throw ? RC_MUST_THROW : 0), 2075 OptoRuntime::uncommon_trap_Type(), 2076 call_addr, "uncommon_trap", no_memory_effects, 2077 intcon(trap_request)); 2078 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request, 2079 "must extract request correctly from the graph"); 2080 assert(trap_request != 0, "zero value reserved by uncommon_trap_request"); 2081 2082 call->set_req(TypeFunc::ReturnAdr, returnadr()); 2083 // The debug info is the only real input to this call. 2084 2085 // Halt-and-catch fire here. The above call should never return! 2086 HaltNode* halt = new(C) HaltNode(control(), frameptr()); 2087 _gvn.set_type_bottom(halt); 2088 root()->add_req(halt); 2089 2090 stop_and_kill_map(); 2091 } 2092 2093 2094 //--------------------------just_allocated_object------------------------------ 2095 // Report the object that was just allocated. 2096 // It must be the case that there are no intervening safepoints. 2097 // We use this to determine if an object is so "fresh" that 2098 // it does not require card marks. 2099 Node* GraphKit::just_allocated_object(Node* current_control) { 2100 if (C->recent_alloc_ctl() == current_control) 2101 return C->recent_alloc_obj(); 2102 return NULL; 2103 } 2104 2105 2106 void GraphKit::round_double_arguments(ciMethod* dest_method) { 2107 // (Note: TypeFunc::make has a cache that makes this fast.) 2108 const TypeFunc* tf = TypeFunc::make(dest_method); 2109 int nargs = tf->_domain->_cnt - TypeFunc::Parms; 2110 for (int j = 0; j < nargs; j++) { 2111 const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms); 2112 if( targ->basic_type() == T_DOUBLE ) { 2113 // If any parameters are doubles, they must be rounded before 2114 // the call, dstore_rounding does gvn.transform 2115 Node *arg = argument(j); 2116 arg = dstore_rounding(arg); 2117 set_argument(j, arg); 2118 } 2119 } 2120 } 2121 2122 /** 2123 * Record profiling data exact_kls for Node n with the type system so 2124 * that it can propagate it (speculation) 2125 * 2126 * @param n node that the type applies to 2127 * @param exact_kls type from profiling 2128 * @param maybe_null did profiling see null? 2129 * 2130 * @return node with improved type 2131 */ 2132 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) { 2133 const Type* current_type = _gvn.type(n); 2134 assert(UseTypeSpeculation, "type speculation must be on"); 2135 2136 const TypePtr* speculative = current_type->speculative(); 2137 2138 // Should the klass from the profile be recorded in the speculative type? 2139 if (current_type->would_improve_type(exact_kls, jvms()->depth())) { 2140 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls); 2141 const TypeOopPtr* xtype = tklass->as_instance_type(); 2142 assert(xtype->klass_is_exact(), "Should be exact"); 2143 // Any reason to believe n is not null (from this profiling or a previous one)? 2144 const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL; 2145 // record the new speculative type's depth 2146 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr(); 2147 speculative = speculative->with_inline_depth(jvms()->depth()); 2148 } else if (current_type->would_improve_ptr(maybe_null)) { 2149 // Profiling report that null was never seen so we can change the 2150 // speculative type to non null ptr. 2151 assert(!maybe_null, "nothing to improve"); 2152 if (speculative == NULL) { 2153 speculative = TypePtr::NOTNULL; 2154 } else { 2155 const TypePtr* ptr = TypePtr::NOTNULL; 2156 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr(); 2157 } 2158 } 2159 2160 if (speculative != current_type->speculative()) { 2161 // Build a type with a speculative type (what we think we know 2162 // about the type but will need a guard when we use it) 2163 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative); 2164 // We're changing the type, we need a new CheckCast node to carry 2165 // the new type. The new type depends on the control: what 2166 // profiling tells us is only valid from here as far as we can 2167 // tell. 2168 Node* cast = new(C) CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type)); 2169 cast = _gvn.transform(cast); 2170 replace_in_map(n, cast); 2171 n = cast; 2172 } 2173 2174 return n; 2175 } 2176 2177 /** 2178 * Record profiling data from receiver profiling at an invoke with the 2179 * type system so that it can propagate it (speculation) 2180 * 2181 * @param n receiver node 2182 * 2183 * @return node with improved type 2184 */ 2185 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) { 2186 if (!UseTypeSpeculation) { 2187 return n; 2188 } 2189 ciKlass* exact_kls = profile_has_unique_klass(); 2190 bool maybe_null = true; 2191 if (java_bc() == Bytecodes::_checkcast || 2192 java_bc() == Bytecodes::_instanceof || 2193 java_bc() == Bytecodes::_aastore) { 2194 ciProfileData* data = method()->method_data()->bci_to_data(bci()); 2195 bool maybe_null = data == NULL ? true : data->as_BitData()->null_seen(); 2196 } 2197 return record_profile_for_speculation(n, exact_kls, maybe_null); 2198 return n; 2199 } 2200 2201 /** 2202 * Record profiling data from argument profiling at an invoke with the 2203 * type system so that it can propagate it (speculation) 2204 * 2205 * @param dest_method target method for the call 2206 * @param bc what invoke bytecode is this? 2207 */ 2208 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) { 2209 if (!UseTypeSpeculation) { 2210 return; 2211 } 2212 const TypeFunc* tf = TypeFunc::make(dest_method); 2213 int nargs = tf->_domain->_cnt - TypeFunc::Parms; 2214 int skip = Bytecodes::has_receiver(bc) ? 1 : 0; 2215 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) { 2216 const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms); 2217 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) { 2218 bool maybe_null = true; 2219 ciKlass* better_type = NULL; 2220 if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) { 2221 record_profile_for_speculation(argument(j), better_type, maybe_null); 2222 } 2223 i++; 2224 } 2225 } 2226 } 2227 2228 /** 2229 * Record profiling data from parameter profiling at an invoke with 2230 * the type system so that it can propagate it (speculation) 2231 */ 2232 void GraphKit::record_profiled_parameters_for_speculation() { 2233 if (!UseTypeSpeculation) { 2234 return; 2235 } 2236 for (int i = 0, j = 0; i < method()->arg_size() ; i++) { 2237 if (_gvn.type(local(i))->isa_oopptr()) { 2238 bool maybe_null = true; 2239 ciKlass* better_type = NULL; 2240 if (method()->parameter_profiled_type(j, better_type, maybe_null)) { 2241 record_profile_for_speculation(local(i), better_type, maybe_null); 2242 } 2243 j++; 2244 } 2245 } 2246 } 2247 2248 /** 2249 * Record profiling data from return value profiling at an invoke with 2250 * the type system so that it can propagate it (speculation) 2251 */ 2252 void GraphKit::record_profiled_return_for_speculation() { 2253 if (!UseTypeSpeculation) { 2254 return; 2255 } 2256 bool maybe_null = true; 2257 ciKlass* better_type = NULL; 2258 if (method()->return_profiled_type(bci(), better_type, maybe_null)) { 2259 // If profiling reports a single type for the return value, 2260 // feed it to the type system so it can propagate it as a 2261 // speculative type 2262 record_profile_for_speculation(stack(sp()-1), better_type, maybe_null); 2263 } 2264 } 2265 2266 void GraphKit::round_double_result(ciMethod* dest_method) { 2267 // A non-strict method may return a double value which has an extended 2268 // exponent, but this must not be visible in a caller which is 'strict' 2269 // If a strict caller invokes a non-strict callee, round a double result 2270 2271 BasicType result_type = dest_method->return_type()->basic_type(); 2272 assert( method() != NULL, "must have caller context"); 2273 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) { 2274 // Destination method's return value is on top of stack 2275 // dstore_rounding() does gvn.transform 2276 Node *result = pop_pair(); 2277 result = dstore_rounding(result); 2278 push_pair(result); 2279 } 2280 } 2281 2282 // rounding for strict float precision conformance 2283 Node* GraphKit::precision_rounding(Node* n) { 2284 return UseStrictFP && _method->flags().is_strict() 2285 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding 2286 ? _gvn.transform( new (C) RoundFloatNode(0, n) ) 2287 : n; 2288 } 2289 2290 // rounding for strict double precision conformance 2291 Node* GraphKit::dprecision_rounding(Node *n) { 2292 return UseStrictFP && _method->flags().is_strict() 2293 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding 2294 ? _gvn.transform( new (C) RoundDoubleNode(0, n) ) 2295 : n; 2296 } 2297 2298 // rounding for non-strict double stores 2299 Node* GraphKit::dstore_rounding(Node* n) { 2300 return Matcher::strict_fp_requires_explicit_rounding 2301 && UseSSE <= 1 2302 ? _gvn.transform( new (C) RoundDoubleNode(0, n) ) 2303 : n; 2304 } 2305 2306 //============================================================================= 2307 // Generate a fast path/slow path idiom. Graph looks like: 2308 // [foo] indicates that 'foo' is a parameter 2309 // 2310 // [in] NULL 2311 // \ / 2312 // CmpP 2313 // Bool ne 2314 // If 2315 // / \ 2316 // True False-<2> 2317 // / | 2318 // / cast_not_null 2319 // Load | | ^ 2320 // [fast_test] | | 2321 // gvn to opt_test | | 2322 // / \ | <1> 2323 // True False | 2324 // | \\ | 2325 // [slow_call] \[fast_result] 2326 // Ctl Val \ \ 2327 // | \ \ 2328 // Catch <1> \ \ 2329 // / \ ^ \ \ 2330 // Ex No_Ex | \ \ 2331 // | \ \ | \ <2> \ 2332 // ... \ [slow_res] | | \ [null_result] 2333 // \ \--+--+--- | | 2334 // \ | / \ | / 2335 // --------Region Phi 2336 // 2337 //============================================================================= 2338 // Code is structured as a series of driver functions all called 'do_XXX' that 2339 // call a set of helper functions. Helper functions first, then drivers. 2340 2341 //------------------------------null_check_oop--------------------------------- 2342 // Null check oop. Set null-path control into Region in slot 3. 2343 // Make a cast-not-nullness use the other not-null control. Return cast. 2344 Node* GraphKit::null_check_oop(Node* value, Node* *null_control, 2345 bool never_see_null, 2346 bool safe_for_replace, 2347 bool speculative) { 2348 // Initial NULL check taken path 2349 (*null_control) = top(); 2350 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative); 2351 2352 // Generate uncommon_trap: 2353 if (never_see_null && (*null_control) != top()) { 2354 // If we see an unexpected null at a check-cast we record it and force a 2355 // recompile; the offending check-cast will be compiled to handle NULLs. 2356 // If we see more than one offending BCI, then all checkcasts in the 2357 // method will be compiled to handle NULLs. 2358 PreserveJVMState pjvms(this); 2359 set_control(*null_control); 2360 replace_in_map(value, null()); 2361 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative); 2362 uncommon_trap(reason, 2363 Deoptimization::Action_make_not_entrant); 2364 (*null_control) = top(); // NULL path is dead 2365 } 2366 if ((*null_control) == top() && safe_for_replace) { 2367 replace_in_map(value, cast); 2368 } 2369 2370 // Cast away null-ness on the result 2371 return cast; 2372 } 2373 2374 //------------------------------opt_iff---------------------------------------- 2375 // Optimize the fast-check IfNode. Set the fast-path region slot 2. 2376 // Return slow-path control. 2377 Node* GraphKit::opt_iff(Node* region, Node* iff) { 2378 IfNode *opt_iff = _gvn.transform(iff)->as_If(); 2379 2380 // Fast path taken; set region slot 2 2381 Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) ); 2382 region->init_req(2,fast_taken); // Capture fast-control 2383 2384 // Fast path not-taken, i.e. slow path 2385 Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) ); 2386 return slow_taken; 2387 } 2388 2389 //-----------------------------make_runtime_call------------------------------- 2390 Node* GraphKit::make_runtime_call(int flags, 2391 const TypeFunc* call_type, address call_addr, 2392 const char* call_name, 2393 const TypePtr* adr_type, 2394 // The following parms are all optional. 2395 // The first NULL ends the list. 2396 Node* parm0, Node* parm1, 2397 Node* parm2, Node* parm3, 2398 Node* parm4, Node* parm5, 2399 Node* parm6, Node* parm7) { 2400 // Slow-path call 2401 bool is_leaf = !(flags & RC_NO_LEAF); 2402 bool has_io = (!is_leaf && !(flags & RC_NO_IO)); 2403 if (call_name == NULL) { 2404 assert(!is_leaf, "must supply name for leaf"); 2405 call_name = OptoRuntime::stub_name(call_addr); 2406 } 2407 CallNode* call; 2408 if (!is_leaf) { 2409 call = new(C) CallStaticJavaNode(call_type, call_addr, call_name, 2410 bci(), adr_type); 2411 } else if (flags & RC_NO_FP) { 2412 call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type); 2413 } else { 2414 call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type); 2415 } 2416 2417 // The following is similar to set_edges_for_java_call, 2418 // except that the memory effects of the call are restricted to AliasIdxRaw. 2419 2420 // Slow path call has no side-effects, uses few values 2421 bool wide_in = !(flags & RC_NARROW_MEM); 2422 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot); 2423 2424 Node* prev_mem = NULL; 2425 if (wide_in) { 2426 prev_mem = set_predefined_input_for_runtime_call(call); 2427 } else { 2428 assert(!wide_out, "narrow in => narrow out"); 2429 Node* narrow_mem = memory(adr_type); 2430 prev_mem = reset_memory(); 2431 map()->set_memory(narrow_mem); 2432 set_predefined_input_for_runtime_call(call); 2433 } 2434 2435 // Hook each parm in order. Stop looking at the first NULL. 2436 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0); 2437 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1); 2438 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2); 2439 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3); 2440 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4); 2441 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5); 2442 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6); 2443 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7); 2444 /* close each nested if ===> */ } } } } } } } } 2445 assert(call->in(call->req()-1) != NULL, "must initialize all parms"); 2446 2447 if (!is_leaf) { 2448 // Non-leaves can block and take safepoints: 2449 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0)); 2450 } 2451 // Non-leaves can throw exceptions: 2452 if (has_io) { 2453 call->set_req(TypeFunc::I_O, i_o()); 2454 } 2455 2456 if (flags & RC_UNCOMMON) { 2457 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency. 2458 // (An "if" probability corresponds roughly to an unconditional count. 2459 // Sort of.) 2460 call->set_cnt(PROB_UNLIKELY_MAG(4)); 2461 } 2462 2463 Node* c = _gvn.transform(call); 2464 assert(c == call, "cannot disappear"); 2465 2466 if (wide_out) { 2467 // Slow path call has full side-effects. 2468 set_predefined_output_for_runtime_call(call); 2469 } else { 2470 // Slow path call has few side-effects, and/or sets few values. 2471 set_predefined_output_for_runtime_call(call, prev_mem, adr_type); 2472 } 2473 2474 if (has_io) { 2475 set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O))); 2476 } 2477 return call; 2478 2479 } 2480 2481 //------------------------------merge_memory----------------------------------- 2482 // Merge memory from one path into the current memory state. 2483 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) { 2484 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) { 2485 Node* old_slice = mms.force_memory(); 2486 Node* new_slice = mms.memory2(); 2487 if (old_slice != new_slice) { 2488 PhiNode* phi; 2489 if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) { 2490 phi = new_slice->as_Phi(); 2491 #ifdef ASSERT 2492 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) 2493 old_slice = old_slice->in(new_path); 2494 // Caller is responsible for ensuring that any pre-existing 2495 // phis are already aware of old memory. 2496 int old_path = (new_path > 1) ? 1 : 2; // choose old_path != new_path 2497 assert(phi->in(old_path) == old_slice, "pre-existing phis OK"); 2498 #endif 2499 mms.set_memory(phi); 2500 } else { 2501 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C)); 2502 _gvn.set_type(phi, Type::MEMORY); 2503 phi->set_req(new_path, new_slice); 2504 mms.set_memory(_gvn.transform(phi)); // assume it is complete 2505 } 2506 } 2507 } 2508 } 2509 2510 //------------------------------make_slow_call_ex------------------------------ 2511 // Make the exception handler hookups for the slow call 2512 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) { 2513 if (stopped()) return; 2514 2515 // Make a catch node with just two handlers: fall-through and catch-all 2516 Node* i_o = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) ); 2517 Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) ); 2518 Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) ); 2519 Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) ); 2520 2521 { PreserveJVMState pjvms(this); 2522 set_control(excp); 2523 set_i_o(i_o); 2524 2525 if (excp != top()) { 2526 // Create an exception state also. 2527 // Use an exact type if the caller has specified a specific exception. 2528 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull); 2529 Node* ex_oop = new (C) CreateExNode(ex_type, control(), i_o); 2530 add_exception_state(make_exception_state(_gvn.transform(ex_oop))); 2531 } 2532 } 2533 2534 // Get the no-exception control from the CatchNode. 2535 set_control(norm); 2536 } 2537 2538 2539 //-------------------------------gen_subtype_check----------------------------- 2540 // Generate a subtyping check. Takes as input the subtype and supertype. 2541 // Returns 2 values: sets the default control() to the true path and returns 2542 // the false path. Only reads invariant memory; sets no (visible) memory. 2543 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding 2544 // but that's not exposed to the optimizer. This call also doesn't take in an 2545 // Object; if you wish to check an Object you need to load the Object's class 2546 // prior to coming here. 2547 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) { 2548 // Fast check for identical types, perhaps identical constants. 2549 // The types can even be identical non-constants, in cases 2550 // involving Array.newInstance, Object.clone, etc. 2551 if (subklass == superklass) 2552 return top(); // false path is dead; no test needed. 2553 2554 if (_gvn.type(superklass)->singleton()) { 2555 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass(); 2556 ciKlass* subk = _gvn.type(subklass)->is_klassptr()->klass(); 2557 2558 // In the common case of an exact superklass, try to fold up the 2559 // test before generating code. You may ask, why not just generate 2560 // the code and then let it fold up? The answer is that the generated 2561 // code will necessarily include null checks, which do not always 2562 // completely fold away. If they are also needless, then they turn 2563 // into a performance loss. Example: 2564 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x; 2565 // Here, the type of 'fa' is often exact, so the store check 2566 // of fa[1]=x will fold up, without testing the nullness of x. 2567 switch (static_subtype_check(superk, subk)) { 2568 case SSC_always_false: 2569 { 2570 Node* always_fail = control(); 2571 set_control(top()); 2572 return always_fail; 2573 } 2574 case SSC_always_true: 2575 return top(); 2576 case SSC_easy_test: 2577 { 2578 // Just do a direct pointer compare and be done. 2579 Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) ); 2580 Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) ); 2581 IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN); 2582 set_control( _gvn.transform( new(C) IfTrueNode (iff) ) ); 2583 return _gvn.transform( new(C) IfFalseNode(iff) ); 2584 } 2585 case SSC_full_test: 2586 break; 2587 default: 2588 ShouldNotReachHere(); 2589 } 2590 } 2591 2592 // %%% Possible further optimization: Even if the superklass is not exact, 2593 // if the subklass is the unique subtype of the superklass, the check 2594 // will always succeed. We could leave a dependency behind to ensure this. 2595 2596 // First load the super-klass's check-offset 2597 Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) ); 2598 Node *chk_off = _gvn.transform(new (C) LoadINode(NULL, memory(p1), p1, _gvn.type(p1)->is_ptr(), 2599 TypeInt::INT, MemNode::unordered)); 2600 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset()); 2601 bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con); 2602 2603 // Load from the sub-klass's super-class display list, or a 1-word cache of 2604 // the secondary superclass list, or a failing value with a sentinel offset 2605 // if the super-klass is an interface or exceptionally deep in the Java 2606 // hierarchy and we have to scan the secondary superclass list the hard way. 2607 // Worst-case type is a little odd: NULL is allowed as a result (usually 2608 // klass loads can never produce a NULL). 2609 Node *chk_off_X = ConvI2X(chk_off); 2610 Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) ); 2611 // For some types like interfaces the following loadKlass is from a 1-word 2612 // cache which is mutable so can't use immutable memory. Other 2613 // types load from the super-class display table which is immutable. 2614 Node *kmem = might_be_cache ? memory(p2) : immutable_memory(); 2615 Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) ); 2616 2617 // Compile speed common case: ARE a subtype and we canNOT fail 2618 if( superklass == nkls ) 2619 return top(); // false path is dead; no test needed. 2620 2621 // See if we get an immediate positive hit. Happens roughly 83% of the 2622 // time. Test to see if the value loaded just previously from the subklass 2623 // is exactly the superklass. 2624 Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) ); 2625 Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) ); 2626 IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN ); 2627 Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) ); 2628 set_control( _gvn.transform( new (C) IfFalseNode( iff1 ) ) ); 2629 2630 // Compile speed common case: Check for being deterministic right now. If 2631 // chk_off is a constant and not equal to cacheoff then we are NOT a 2632 // subklass. In this case we need exactly the 1 test above and we can 2633 // return those results immediately. 2634 if (!might_be_cache) { 2635 Node* not_subtype_ctrl = control(); 2636 set_control(iftrue1); // We need exactly the 1 test above 2637 return not_subtype_ctrl; 2638 } 2639 2640 // Gather the various success & failures here 2641 RegionNode *r_ok_subtype = new (C) RegionNode(4); 2642 record_for_igvn(r_ok_subtype); 2643 RegionNode *r_not_subtype = new (C) RegionNode(3); 2644 record_for_igvn(r_not_subtype); 2645 2646 r_ok_subtype->init_req(1, iftrue1); 2647 2648 // Check for immediate negative hit. Happens roughly 11% of the time (which 2649 // is roughly 63% of the remaining cases). Test to see if the loaded 2650 // check-offset points into the subklass display list or the 1-element 2651 // cache. If it points to the display (and NOT the cache) and the display 2652 // missed then it's not a subtype. 2653 Node *cacheoff = _gvn.intcon(cacheoff_con); 2654 Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) ); 2655 Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) ); 2656 IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN ); 2657 r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) ); 2658 set_control( _gvn.transform( new (C) IfFalseNode(iff2) ) ); 2659 2660 // Check for self. Very rare to get here, but it is taken 1/3 the time. 2661 // No performance impact (too rare) but allows sharing of secondary arrays 2662 // which has some footprint reduction. 2663 Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) ); 2664 Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) ); 2665 IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN ); 2666 r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) ); 2667 set_control( _gvn.transform( new (C) IfFalseNode( iff3 ) ) ); 2668 2669 // -- Roads not taken here: -- 2670 // We could also have chosen to perform the self-check at the beginning 2671 // of this code sequence, as the assembler does. This would not pay off 2672 // the same way, since the optimizer, unlike the assembler, can perform 2673 // static type analysis to fold away many successful self-checks. 2674 // Non-foldable self checks work better here in second position, because 2675 // the initial primary superclass check subsumes a self-check for most 2676 // types. An exception would be a secondary type like array-of-interface, 2677 // which does not appear in its own primary supertype display. 2678 // Finally, we could have chosen to move the self-check into the 2679 // PartialSubtypeCheckNode, and from there out-of-line in a platform 2680 // dependent manner. But it is worthwhile to have the check here, 2681 // where it can be perhaps be optimized. The cost in code space is 2682 // small (register compare, branch). 2683 2684 // Now do a linear scan of the secondary super-klass array. Again, no real 2685 // performance impact (too rare) but it's gotta be done. 2686 // Since the code is rarely used, there is no penalty for moving it 2687 // out of line, and it can only improve I-cache density. 2688 // The decision to inline or out-of-line this final check is platform 2689 // dependent, and is found in the AD file definition of PartialSubtypeCheck. 2690 Node* psc = _gvn.transform( 2691 new (C) PartialSubtypeCheckNode(control(), subklass, superklass) ); 2692 2693 Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) ); 2694 Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) ); 2695 IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN ); 2696 r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) ); 2697 r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) ); 2698 2699 // Return false path; set default control to true path. 2700 set_control( _gvn.transform(r_ok_subtype) ); 2701 return _gvn.transform(r_not_subtype); 2702 } 2703 2704 //----------------------------static_subtype_check----------------------------- 2705 // Shortcut important common cases when superklass is exact: 2706 // (0) superklass is java.lang.Object (can occur in reflective code) 2707 // (1) subklass is already limited to a subtype of superklass => always ok 2708 // (2) subklass does not overlap with superklass => always fail 2709 // (3) superklass has NO subtypes and we can check with a simple compare. 2710 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) { 2711 if (StressReflectiveCode) { 2712 return SSC_full_test; // Let caller generate the general case. 2713 } 2714 2715 if (superk == env()->Object_klass()) { 2716 return SSC_always_true; // (0) this test cannot fail 2717 } 2718 2719 ciType* superelem = superk; 2720 if (superelem->is_array_klass()) 2721 superelem = superelem->as_array_klass()->base_element_type(); 2722 2723 if (!subk->is_interface()) { // cannot trust static interface types yet 2724 if (subk->is_subtype_of(superk)) { 2725 return SSC_always_true; // (1) false path dead; no dynamic test needed 2726 } 2727 if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) && 2728 !superk->is_subtype_of(subk)) { 2729 return SSC_always_false; 2730 } 2731 } 2732 2733 // If casting to an instance klass, it must have no subtypes 2734 if (superk->is_interface()) { 2735 // Cannot trust interfaces yet. 2736 // %%% S.B. superk->nof_implementors() == 1 2737 } else if (superelem->is_instance_klass()) { 2738 ciInstanceKlass* ik = superelem->as_instance_klass(); 2739 if (!ik->has_subklass() && !ik->is_interface()) { 2740 if (!ik->is_final()) { 2741 // Add a dependency if there is a chance of a later subclass. 2742 C->dependencies()->assert_leaf_type(ik); 2743 } 2744 return SSC_easy_test; // (3) caller can do a simple ptr comparison 2745 } 2746 } else { 2747 // A primitive array type has no subtypes. 2748 return SSC_easy_test; // (3) caller can do a simple ptr comparison 2749 } 2750 2751 return SSC_full_test; 2752 } 2753 2754 // Profile-driven exact type check: 2755 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass, 2756 float prob, 2757 Node* *casted_receiver) { 2758 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass); 2759 Node* recv_klass = load_object_klass(receiver); 2760 Node* want_klass = makecon(tklass); 2761 Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) ); 2762 Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) ); 2763 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN); 2764 set_control( _gvn.transform( new(C) IfTrueNode (iff) )); 2765 Node* fail = _gvn.transform( new(C) IfFalseNode(iff) ); 2766 2767 const TypeOopPtr* recv_xtype = tklass->as_instance_type(); 2768 assert(recv_xtype->klass_is_exact(), ""); 2769 2770 // Subsume downstream occurrences of receiver with a cast to 2771 // recv_xtype, since now we know what the type will be. 2772 Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype); 2773 (*casted_receiver) = _gvn.transform(cast); 2774 // (User must make the replace_in_map call.) 2775 2776 return fail; 2777 } 2778 2779 2780 //------------------------------seems_never_null------------------------------- 2781 // Use null_seen information if it is available from the profile. 2782 // If we see an unexpected null at a type check we record it and force a 2783 // recompile; the offending check will be recompiled to handle NULLs. 2784 // If we see several offending BCIs, then all checks in the 2785 // method will be recompiled. 2786 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) { 2787 speculating = !_gvn.type(obj)->speculative_maybe_null(); 2788 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating); 2789 if (UncommonNullCast // Cutout for this technique 2790 && obj != null() // And not the -Xcomp stupid case? 2791 && !too_many_traps(reason) 2792 ) { 2793 if (speculating) { 2794 return true; 2795 } 2796 if (data == NULL) 2797 // Edge case: no mature data. Be optimistic here. 2798 return true; 2799 // If the profile has not seen a null, assume it won't happen. 2800 assert(java_bc() == Bytecodes::_checkcast || 2801 java_bc() == Bytecodes::_instanceof || 2802 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here"); 2803 return !data->as_BitData()->null_seen(); 2804 } 2805 speculating = false; 2806 return false; 2807 } 2808 2809 //------------------------maybe_cast_profiled_receiver------------------------- 2810 // If the profile has seen exactly one type, narrow to exactly that type. 2811 // Subsequent type checks will always fold up. 2812 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj, 2813 ciKlass* require_klass, 2814 ciKlass* spec_klass, 2815 bool safe_for_replace) { 2816 if (!UseTypeProfile || !TypeProfileCasts) return NULL; 2817 2818 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL); 2819 2820 // Make sure we haven't already deoptimized from this tactic. 2821 if (too_many_traps(reason)) 2822 return NULL; 2823 2824 // (No, this isn't a call, but it's enough like a virtual call 2825 // to use the same ciMethod accessor to get the profile info...) 2826 // If we have a speculative type use it instead of profiling (which 2827 // may not help us) 2828 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass; 2829 if (exact_kls != NULL) {// no cast failures here 2830 if (require_klass == NULL || 2831 static_subtype_check(require_klass, exact_kls) == SSC_always_true) { 2832 // If we narrow the type to match what the type profile sees or 2833 // the speculative type, we can then remove the rest of the 2834 // cast. 2835 // This is a win, even if the exact_kls is very specific, 2836 // because downstream operations, such as method calls, 2837 // will often benefit from the sharper type. 2838 Node* exact_obj = not_null_obj; // will get updated in place... 2839 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, 2840 &exact_obj); 2841 { PreserveJVMState pjvms(this); 2842 set_control(slow_ctl); 2843 uncommon_trap(reason, 2844 Deoptimization::Action_maybe_recompile); 2845 } 2846 if (safe_for_replace) { 2847 replace_in_map(not_null_obj, exact_obj); 2848 } 2849 return exact_obj; 2850 } 2851 // assert(ssc == SSC_always_true)... except maybe the profile lied to us. 2852 } 2853 2854 return NULL; 2855 } 2856 2857 /** 2858 * Cast obj to type and emit guard unless we had too many traps here 2859 * already 2860 * 2861 * @param obj node being casted 2862 * @param type type to cast the node to 2863 * @param not_null true if we know node cannot be null 2864 */ 2865 Node* GraphKit::maybe_cast_profiled_obj(Node* obj, 2866 ciKlass* type, 2867 bool not_null) { 2868 // type == NULL if profiling tells us this object is always null 2869 if (type != NULL) { 2870 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check; 2871 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check; 2872 if (!too_many_traps(null_reason) && 2873 !too_many_traps(class_reason)) { 2874 Node* not_null_obj = NULL; 2875 // not_null is true if we know the object is not null and 2876 // there's no need for a null check 2877 if (!not_null) { 2878 Node* null_ctl = top(); 2879 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true); 2880 assert(null_ctl->is_top(), "no null control here"); 2881 } else { 2882 not_null_obj = obj; 2883 } 2884 2885 Node* exact_obj = not_null_obj; 2886 ciKlass* exact_kls = type; 2887 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, 2888 &exact_obj); 2889 { 2890 PreserveJVMState pjvms(this); 2891 set_control(slow_ctl); 2892 uncommon_trap(class_reason, 2893 Deoptimization::Action_maybe_recompile); 2894 } 2895 replace_in_map(not_null_obj, exact_obj); 2896 obj = exact_obj; 2897 } 2898 } else { 2899 if (!too_many_traps(Deoptimization::Reason_null_assert)) { 2900 Node* exact_obj = null_assert(obj); 2901 replace_in_map(obj, exact_obj); 2902 obj = exact_obj; 2903 } 2904 } 2905 return obj; 2906 } 2907 2908 //-------------------------------gen_instanceof-------------------------------- 2909 // Generate an instance-of idiom. Used by both the instance-of bytecode 2910 // and the reflective instance-of call. 2911 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) { 2912 kill_dead_locals(); // Benefit all the uncommon traps 2913 assert( !stopped(), "dead parse path should be checked in callers" ); 2914 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()), 2915 "must check for not-null not-dead klass in callers"); 2916 2917 // Make the merge point 2918 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT }; 2919 RegionNode* region = new(C) RegionNode(PATH_LIMIT); 2920 Node* phi = new(C) PhiNode(region, TypeInt::BOOL); 2921 C->set_has_split_ifs(true); // Has chance for split-if optimization 2922 2923 ciProfileData* data = NULL; 2924 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode 2925 data = method()->method_data()->bci_to_data(bci()); 2926 } 2927 bool speculative_not_null = false; 2928 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile 2929 && seems_never_null(obj, data, speculative_not_null)); 2930 2931 // Null check; get casted pointer; set region slot 3 2932 Node* null_ctl = top(); 2933 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null); 2934 2935 // If not_null_obj is dead, only null-path is taken 2936 if (stopped()) { // Doing instance-of on a NULL? 2937 set_control(null_ctl); 2938 return intcon(0); 2939 } 2940 region->init_req(_null_path, null_ctl); 2941 phi ->init_req(_null_path, intcon(0)); // Set null path value 2942 if (null_ctl == top()) { 2943 // Do this eagerly, so that pattern matches like is_diamond_phi 2944 // will work even during parsing. 2945 assert(_null_path == PATH_LIMIT-1, "delete last"); 2946 region->del_req(_null_path); 2947 phi ->del_req(_null_path); 2948 } 2949 2950 // Do we know the type check always succeed? 2951 bool known_statically = false; 2952 if (_gvn.type(superklass)->singleton()) { 2953 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass(); 2954 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass(); 2955 if (subk != NULL && subk->is_loaded()) { 2956 int static_res = static_subtype_check(superk, subk); 2957 known_statically = (static_res == SSC_always_true || static_res == SSC_always_false); 2958 } 2959 } 2960 2961 if (known_statically && UseTypeSpeculation) { 2962 // If we know the type check always succeeds then we don't use the 2963 // profiling data at this bytecode. Don't lose it, feed it to the 2964 // type system as a speculative type. 2965 not_null_obj = record_profiled_receiver_for_speculation(not_null_obj); 2966 } else { 2967 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr(); 2968 // We may not have profiling here or it may not help us. If we 2969 // have a speculative type use it to perform an exact cast. 2970 ciKlass* spec_obj_type = obj_type->speculative_type(); 2971 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) { 2972 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace); 2973 if (stopped()) { // Profile disagrees with this path. 2974 set_control(null_ctl); // Null is the only remaining possibility. 2975 return intcon(0); 2976 } 2977 if (cast_obj != NULL) { 2978 not_null_obj = cast_obj; 2979 } 2980 } 2981 } 2982 2983 // Load the object's klass 2984 Node* obj_klass = load_object_klass(not_null_obj); 2985 2986 // Generate the subtype check 2987 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass); 2988 2989 // Plug in the success path to the general merge in slot 1. 2990 region->init_req(_obj_path, control()); 2991 phi ->init_req(_obj_path, intcon(1)); 2992 2993 // Plug in the failing path to the general merge in slot 2. 2994 region->init_req(_fail_path, not_subtype_ctrl); 2995 phi ->init_req(_fail_path, intcon(0)); 2996 2997 // Return final merged results 2998 set_control( _gvn.transform(region) ); 2999 record_for_igvn(region); 3000 return _gvn.transform(phi); 3001 } 3002 3003 //-------------------------------gen_checkcast--------------------------------- 3004 // Generate a checkcast idiom. Used by both the checkcast bytecode and the 3005 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the 3006 // uncommon-trap paths work. Adjust stack after this call. 3007 // If failure_control is supplied and not null, it is filled in with 3008 // the control edge for the cast failure. Otherwise, an appropriate 3009 // uncommon trap or exception is thrown. 3010 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass, 3011 Node* *failure_control) { 3012 kill_dead_locals(); // Benefit all the uncommon traps 3013 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr(); 3014 const Type *toop = TypeOopPtr::make_from_klass(tk->klass()); 3015 3016 // Fast cutout: Check the case that the cast is vacuously true. 3017 // This detects the common cases where the test will short-circuit 3018 // away completely. We do this before we perform the null check, 3019 // because if the test is going to turn into zero code, we don't 3020 // want a residual null check left around. (Causes a slowdown, 3021 // for example, in some objArray manipulations, such as a[i]=a[j].) 3022 if (tk->singleton()) { 3023 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr(); 3024 if (objtp != NULL && objtp->klass() != NULL) { 3025 switch (static_subtype_check(tk->klass(), objtp->klass())) { 3026 case SSC_always_true: 3027 // If we know the type check always succeed then we don't use 3028 // the profiling data at this bytecode. Don't lose it, feed it 3029 // to the type system as a speculative type. 3030 return record_profiled_receiver_for_speculation(obj); 3031 case SSC_always_false: 3032 // It needs a null check because a null will *pass* the cast check. 3033 // A non-null value will always produce an exception. 3034 return null_assert(obj); 3035 } 3036 } 3037 } 3038 3039 ciProfileData* data = NULL; 3040 bool safe_for_replace = false; 3041 if (failure_control == NULL) { // use MDO in regular case only 3042 assert(java_bc() == Bytecodes::_aastore || 3043 java_bc() == Bytecodes::_checkcast, 3044 "interpreter profiles type checks only for these BCs"); 3045 data = method()->method_data()->bci_to_data(bci()); 3046 safe_for_replace = true; 3047 } 3048 3049 // Make the merge point 3050 enum { _obj_path = 1, _null_path, PATH_LIMIT }; 3051 RegionNode* region = new (C) RegionNode(PATH_LIMIT); 3052 Node* phi = new (C) PhiNode(region, toop); 3053 C->set_has_split_ifs(true); // Has chance for split-if optimization 3054 3055 // Use null-cast information if it is available 3056 bool speculative_not_null = false; 3057 bool never_see_null = ((failure_control == NULL) // regular case only 3058 && seems_never_null(obj, data, speculative_not_null)); 3059 3060 // Null check; get casted pointer; set region slot 3 3061 Node* null_ctl = top(); 3062 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null); 3063 3064 // If not_null_obj is dead, only null-path is taken 3065 if (stopped()) { // Doing instance-of on a NULL? 3066 set_control(null_ctl); 3067 return null(); 3068 } 3069 region->init_req(_null_path, null_ctl); 3070 phi ->init_req(_null_path, null()); // Set null path value 3071 if (null_ctl == top()) { 3072 // Do this eagerly, so that pattern matches like is_diamond_phi 3073 // will work even during parsing. 3074 assert(_null_path == PATH_LIMIT-1, "delete last"); 3075 region->del_req(_null_path); 3076 phi ->del_req(_null_path); 3077 } 3078 3079 Node* cast_obj = NULL; 3080 if (tk->klass_is_exact()) { 3081 // The following optimization tries to statically cast the speculative type of the object 3082 // (for example obtained during profiling) to the type of the superklass and then do a 3083 // dynamic check that the type of the object is what we expect. To work correctly 3084 // for checkcast and aastore the type of superklass should be exact. 3085 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr(); 3086 // We may not have profiling here or it may not help us. If we have 3087 // a speculative type use it to perform an exact cast. 3088 ciKlass* spec_obj_type = obj_type->speculative_type(); 3089 if (spec_obj_type != NULL || 3090 (data != NULL && 3091 // Counter has never been decremented (due to cast failure). 3092 // ...This is a reasonable thing to expect. It is true of 3093 // all casts inserted by javac to implement generic types. 3094 data->as_CounterData()->count() >= 0)) { 3095 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace); 3096 if (cast_obj != NULL) { 3097 if (failure_control != NULL) // failure is now impossible 3098 (*failure_control) = top(); 3099 // adjust the type of the phi to the exact klass: 3100 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR)); 3101 } 3102 } 3103 } 3104 3105 if (cast_obj == NULL) { 3106 // Load the object's klass 3107 Node* obj_klass = load_object_klass(not_null_obj); 3108 3109 // Generate the subtype check 3110 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass ); 3111 3112 // Plug in success path into the merge 3113 cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(), 3114 not_null_obj, toop)); 3115 // Failure path ends in uncommon trap (or may be dead - failure impossible) 3116 if (failure_control == NULL) { 3117 if (not_subtype_ctrl != top()) { // If failure is possible 3118 PreserveJVMState pjvms(this); 3119 set_control(not_subtype_ctrl); 3120 builtin_throw(Deoptimization::Reason_class_check, obj_klass); 3121 } 3122 } else { 3123 (*failure_control) = not_subtype_ctrl; 3124 } 3125 } 3126 3127 region->init_req(_obj_path, control()); 3128 phi ->init_req(_obj_path, cast_obj); 3129 3130 // A merge of NULL or Casted-NotNull obj 3131 Node* res = _gvn.transform(phi); 3132 3133 // Note I do NOT always 'replace_in_map(obj,result)' here. 3134 // if( tk->klass()->can_be_primary_super() ) 3135 // This means that if I successfully store an Object into an array-of-String 3136 // I 'forget' that the Object is really now known to be a String. I have to 3137 // do this because we don't have true union types for interfaces - if I store 3138 // a Baz into an array-of-Interface and then tell the optimizer it's an 3139 // Interface, I forget that it's also a Baz and cannot do Baz-like field 3140 // references to it. FIX THIS WHEN UNION TYPES APPEAR! 3141 // replace_in_map( obj, res ); 3142 3143 // Return final merged results 3144 set_control( _gvn.transform(region) ); 3145 record_for_igvn(region); 3146 return res; 3147 } 3148 3149 //------------------------------next_monitor----------------------------------- 3150 // What number should be given to the next monitor? 3151 int GraphKit::next_monitor() { 3152 int current = jvms()->monitor_depth()* C->sync_stack_slots(); 3153 int next = current + C->sync_stack_slots(); 3154 // Keep the toplevel high water mark current: 3155 if (C->fixed_slots() < next) C->set_fixed_slots(next); 3156 return current; 3157 } 3158 3159 //------------------------------insert_mem_bar--------------------------------- 3160 // Memory barrier to avoid floating things around 3161 // The membar serves as a pinch point between both control and all memory slices. 3162 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) { 3163 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent); 3164 mb->init_req(TypeFunc::Control, control()); 3165 mb->init_req(TypeFunc::Memory, reset_memory()); 3166 Node* membar = _gvn.transform(mb); 3167 set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control))); 3168 set_all_memory_call(membar); 3169 return membar; 3170 } 3171 3172 //-------------------------insert_mem_bar_volatile---------------------------- 3173 // Memory barrier to avoid floating things around 3174 // The membar serves as a pinch point between both control and memory(alias_idx). 3175 // If you want to make a pinch point on all memory slices, do not use this 3176 // function (even with AliasIdxBot); use insert_mem_bar() instead. 3177 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) { 3178 // When Parse::do_put_xxx updates a volatile field, it appends a series 3179 // of MemBarVolatile nodes, one for *each* volatile field alias category. 3180 // The first membar is on the same memory slice as the field store opcode. 3181 // This forces the membar to follow the store. (Bug 6500685 broke this.) 3182 // All the other membars (for other volatile slices, including AliasIdxBot, 3183 // which stands for all unknown volatile slices) are control-dependent 3184 // on the first membar. This prevents later volatile loads or stores 3185 // from sliding up past the just-emitted store. 3186 3187 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent); 3188 mb->set_req(TypeFunc::Control,control()); 3189 if (alias_idx == Compile::AliasIdxBot) { 3190 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory()); 3191 } else { 3192 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller"); 3193 mb->set_req(TypeFunc::Memory, memory(alias_idx)); 3194 } 3195 Node* membar = _gvn.transform(mb); 3196 set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control))); 3197 if (alias_idx == Compile::AliasIdxBot) { 3198 merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory))); 3199 } else { 3200 set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx); 3201 } 3202 return membar; 3203 } 3204 3205 //------------------------------shared_lock------------------------------------ 3206 // Emit locking code. 3207 FastLockNode* GraphKit::shared_lock(Node* obj) { 3208 // bci is either a monitorenter bc or InvocationEntryBci 3209 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces 3210 assert(SynchronizationEntryBCI == InvocationEntryBci, ""); 3211 3212 if( !GenerateSynchronizationCode ) 3213 return NULL; // Not locking things? 3214 if (stopped()) // Dead monitor? 3215 return NULL; 3216 3217 assert(dead_locals_are_killed(), "should kill locals before sync. point"); 3218 3219 // Box the stack location 3220 Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor())); 3221 Node* mem = reset_memory(); 3222 3223 FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock(); 3224 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) { 3225 // Create the counters for this fast lock. 3226 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci 3227 } 3228 3229 // Create the rtm counters for this fast lock if needed. 3230 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci 3231 3232 // Add monitor to debug info for the slow path. If we block inside the 3233 // slow path and de-opt, we need the monitor hanging around 3234 map()->push_monitor( flock ); 3235 3236 const TypeFunc *tf = LockNode::lock_type(); 3237 LockNode *lock = new (C) LockNode(C, tf); 3238 3239 lock->init_req( TypeFunc::Control, control() ); 3240 lock->init_req( TypeFunc::Memory , mem ); 3241 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o 3242 lock->init_req( TypeFunc::FramePtr, frameptr() ); 3243 lock->init_req( TypeFunc::ReturnAdr, top() ); 3244 3245 lock->init_req(TypeFunc::Parms + 0, obj); 3246 lock->init_req(TypeFunc::Parms + 1, box); 3247 lock->init_req(TypeFunc::Parms + 2, flock); 3248 add_safepoint_edges(lock); 3249 3250 lock = _gvn.transform( lock )->as_Lock(); 3251 3252 // lock has no side-effects, sets few values 3253 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM); 3254 3255 insert_mem_bar(Op_MemBarAcquireLock); 3256 3257 // Add this to the worklist so that the lock can be eliminated 3258 record_for_igvn(lock); 3259 3260 #ifndef PRODUCT 3261 if (PrintLockStatistics) { 3262 // Update the counter for this lock. Don't bother using an atomic 3263 // operation since we don't require absolute accuracy. 3264 lock->create_lock_counter(map()->jvms()); 3265 increment_counter(lock->counter()->addr()); 3266 } 3267 #endif 3268 3269 return flock; 3270 } 3271 3272 3273 //------------------------------shared_unlock---------------------------------- 3274 // Emit unlocking code. 3275 void GraphKit::shared_unlock(Node* box, Node* obj) { 3276 // bci is either a monitorenter bc or InvocationEntryBci 3277 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces 3278 assert(SynchronizationEntryBCI == InvocationEntryBci, ""); 3279 3280 if( !GenerateSynchronizationCode ) 3281 return; 3282 if (stopped()) { // Dead monitor? 3283 map()->pop_monitor(); // Kill monitor from debug info 3284 return; 3285 } 3286 3287 // Memory barrier to avoid floating things down past the locked region 3288 insert_mem_bar(Op_MemBarReleaseLock); 3289 3290 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type(); 3291 UnlockNode *unlock = new (C) UnlockNode(C, tf); 3292 uint raw_idx = Compile::AliasIdxRaw; 3293 unlock->init_req( TypeFunc::Control, control() ); 3294 unlock->init_req( TypeFunc::Memory , memory(raw_idx) ); 3295 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o 3296 unlock->init_req( TypeFunc::FramePtr, frameptr() ); 3297 unlock->init_req( TypeFunc::ReturnAdr, top() ); 3298 3299 unlock->init_req(TypeFunc::Parms + 0, obj); 3300 unlock->init_req(TypeFunc::Parms + 1, box); 3301 unlock = _gvn.transform(unlock)->as_Unlock(); 3302 3303 Node* mem = reset_memory(); 3304 3305 // unlock has no side-effects, sets few values 3306 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM); 3307 3308 // Kill monitor from debug info 3309 map()->pop_monitor( ); 3310 } 3311 3312 //-------------------------------get_layout_helper----------------------------- 3313 // If the given klass is a constant or known to be an array, 3314 // fetch the constant layout helper value into constant_value 3315 // and return (Node*)NULL. Otherwise, load the non-constant 3316 // layout helper value, and return the node which represents it. 3317 // This two-faced routine is useful because allocation sites 3318 // almost always feature constant types. 3319 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) { 3320 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr(); 3321 if (!StressReflectiveCode && inst_klass != NULL) { 3322 ciKlass* klass = inst_klass->klass(); 3323 bool xklass = inst_klass->klass_is_exact(); 3324 if (xklass || klass->is_array_klass()) { 3325 jint lhelper = klass->layout_helper(); 3326 if (lhelper != Klass::_lh_neutral_value) { 3327 constant_value = lhelper; 3328 return (Node*) NULL; 3329 } 3330 } 3331 } 3332 constant_value = Klass::_lh_neutral_value; // put in a known value 3333 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset())); 3334 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered); 3335 } 3336 3337 // We just put in an allocate/initialize with a big raw-memory effect. 3338 // Hook selected additional alias categories on the initialization. 3339 static void hook_memory_on_init(GraphKit& kit, int alias_idx, 3340 MergeMemNode* init_in_merge, 3341 Node* init_out_raw) { 3342 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory()); 3343 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, ""); 3344 3345 Node* prevmem = kit.memory(alias_idx); 3346 init_in_merge->set_memory_at(alias_idx, prevmem); 3347 kit.set_memory(init_out_raw, alias_idx); 3348 } 3349 3350 //---------------------------set_output_for_allocation------------------------- 3351 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc, 3352 const TypeOopPtr* oop_type) { 3353 int rawidx = Compile::AliasIdxRaw; 3354 alloc->set_req( TypeFunc::FramePtr, frameptr() ); 3355 add_safepoint_edges(alloc); 3356 Node* allocx = _gvn.transform(alloc); 3357 set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) ); 3358 // create memory projection for i_o 3359 set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx ); 3360 make_slow_call_ex(allocx, env()->Throwable_klass(), true); 3361 3362 // create a memory projection as for the normal control path 3363 Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory)); 3364 set_memory(malloc, rawidx); 3365 3366 // a normal slow-call doesn't change i_o, but an allocation does 3367 // we create a separate i_o projection for the normal control path 3368 set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) ); 3369 Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) ); 3370 3371 // put in an initialization barrier 3372 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx, 3373 rawoop)->as_Initialize(); 3374 assert(alloc->initialization() == init, "2-way macro link must work"); 3375 assert(init ->allocation() == alloc, "2-way macro link must work"); 3376 { 3377 // Extract memory strands which may participate in the new object's 3378 // initialization, and source them from the new InitializeNode. 3379 // This will allow us to observe initializations when they occur, 3380 // and link them properly (as a group) to the InitializeNode. 3381 assert(init->in(InitializeNode::Memory) == malloc, ""); 3382 MergeMemNode* minit_in = MergeMemNode::make(C, malloc); 3383 init->set_req(InitializeNode::Memory, minit_in); 3384 record_for_igvn(minit_in); // fold it up later, if possible 3385 Node* minit_out = memory(rawidx); 3386 assert(minit_out->is_Proj() && minit_out->in(0) == init, ""); 3387 if (oop_type->isa_aryptr()) { 3388 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot); 3389 int elemidx = C->get_alias_index(telemref); 3390 hook_memory_on_init(*this, elemidx, minit_in, minit_out); 3391 } else if (oop_type->isa_instptr()) { 3392 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass(); 3393 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) { 3394 ciField* field = ik->nonstatic_field_at(i); 3395 if (field->offset() >= TrackedInitializationLimit * HeapWordSize) 3396 continue; // do not bother to track really large numbers of fields 3397 // Find (or create) the alias category for this field: 3398 int fieldidx = C->alias_type(field)->index(); 3399 hook_memory_on_init(*this, fieldidx, minit_in, minit_out); 3400 } 3401 } 3402 } 3403 3404 // Cast raw oop to the real thing... 3405 Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type); 3406 javaoop = _gvn.transform(javaoop); 3407 C->set_recent_alloc(control(), javaoop); 3408 assert(just_allocated_object(control()) == javaoop, "just allocated"); 3409 3410 #ifdef ASSERT 3411 { // Verify that the AllocateNode::Ideal_allocation recognizers work: 3412 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc, 3413 "Ideal_allocation works"); 3414 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc, 3415 "Ideal_allocation works"); 3416 if (alloc->is_AllocateArray()) { 3417 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(), 3418 "Ideal_allocation works"); 3419 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(), 3420 "Ideal_allocation works"); 3421 } else { 3422 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please"); 3423 } 3424 } 3425 #endif //ASSERT 3426 3427 return javaoop; 3428 } 3429 3430 //---------------------------new_instance-------------------------------------- 3431 // This routine takes a klass_node which may be constant (for a static type) 3432 // or may be non-constant (for reflective code). It will work equally well 3433 // for either, and the graph will fold nicely if the optimizer later reduces 3434 // the type to a constant. 3435 // The optional arguments are for specialized use by intrinsics: 3436 // - If 'extra_slow_test' if not null is an extra condition for the slow-path. 3437 // - If 'return_size_val', report the the total object size to the caller. 3438 Node* GraphKit::new_instance(Node* klass_node, 3439 Node* extra_slow_test, 3440 Node* *return_size_val) { 3441 // Compute size in doublewords 3442 // The size is always an integral number of doublewords, represented 3443 // as a positive bytewise size stored in the klass's layout_helper. 3444 // The layout_helper also encodes (in a low bit) the need for a slow path. 3445 jint layout_con = Klass::_lh_neutral_value; 3446 Node* layout_val = get_layout_helper(klass_node, layout_con); 3447 int layout_is_con = (layout_val == NULL); 3448 3449 if (extra_slow_test == NULL) extra_slow_test = intcon(0); 3450 // Generate the initial go-slow test. It's either ALWAYS (return a 3451 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective 3452 // case) a computed value derived from the layout_helper. 3453 Node* initial_slow_test = NULL; 3454 if (layout_is_con) { 3455 assert(!StressReflectiveCode, "stress mode does not use these paths"); 3456 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con); 3457 initial_slow_test = must_go_slow? intcon(1): extra_slow_test; 3458 3459 } else { // reflective case 3460 // This reflective path is used by Unsafe.allocateInstance. 3461 // (It may be stress-tested by specifying StressReflectiveCode.) 3462 // Basically, we want to get into the VM is there's an illegal argument. 3463 Node* bit = intcon(Klass::_lh_instance_slow_path_bit); 3464 initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) ); 3465 if (extra_slow_test != intcon(0)) { 3466 initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) ); 3467 } 3468 // (Macro-expander will further convert this to a Bool, if necessary.) 3469 } 3470 3471 // Find the size in bytes. This is easy; it's the layout_helper. 3472 // The size value must be valid even if the slow path is taken. 3473 Node* size = NULL; 3474 if (layout_is_con) { 3475 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con)); 3476 } else { // reflective case 3477 // This reflective path is used by clone and Unsafe.allocateInstance. 3478 size = ConvI2X(layout_val); 3479 3480 // Clear the low bits to extract layout_helper_size_in_bytes: 3481 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit"); 3482 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong)); 3483 size = _gvn.transform( new (C) AndXNode(size, mask) ); 3484 } 3485 if (return_size_val != NULL) { 3486 (*return_size_val) = size; 3487 } 3488 3489 // This is a precise notnull oop of the klass. 3490 // (Actually, it need not be precise if this is a reflective allocation.) 3491 // It's what we cast the result to. 3492 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr(); 3493 if (!tklass) tklass = TypeKlassPtr::OBJECT; 3494 const TypeOopPtr* oop_type = tklass->as_instance_type(); 3495 3496 // Now generate allocation code 3497 3498 // The entire memory state is needed for slow path of the allocation 3499 // since GC and deoptimization can happened. 3500 Node *mem = reset_memory(); 3501 set_all_memory(mem); // Create new memory state 3502 3503 AllocateNode* alloc 3504 = new (C) AllocateNode(C, AllocateNode::alloc_type(Type::TOP), 3505 control(), mem, i_o(), 3506 size, klass_node, 3507 initial_slow_test); 3508 3509 return set_output_for_allocation(alloc, oop_type); 3510 } 3511 3512 //-------------------------------new_array------------------------------------- 3513 // helper for both newarray and anewarray 3514 // The 'length' parameter is (obviously) the length of the array. 3515 // See comments on new_instance for the meaning of the other arguments. 3516 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable) 3517 Node* length, // number of array elements 3518 int nargs, // number of arguments to push back for uncommon trap 3519 Node* *return_size_val) { 3520 jint layout_con = Klass::_lh_neutral_value; 3521 Node* layout_val = get_layout_helper(klass_node, layout_con); 3522 int layout_is_con = (layout_val == NULL); 3523 3524 if (!layout_is_con && !StressReflectiveCode && 3525 !too_many_traps(Deoptimization::Reason_class_check)) { 3526 // This is a reflective array creation site. 3527 // Optimistically assume that it is a subtype of Object[], 3528 // so that we can fold up all the address arithmetic. 3529 layout_con = Klass::array_layout_helper(T_OBJECT); 3530 Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) ); 3531 Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) ); 3532 { BuildCutout unless(this, bol_lh, PROB_MAX); 3533 inc_sp(nargs); 3534 uncommon_trap(Deoptimization::Reason_class_check, 3535 Deoptimization::Action_maybe_recompile); 3536 } 3537 layout_val = NULL; 3538 layout_is_con = true; 3539 } 3540 3541 // Generate the initial go-slow test. Make sure we do not overflow 3542 // if length is huge (near 2Gig) or negative! We do not need 3543 // exact double-words here, just a close approximation of needed 3544 // double-words. We can't add any offset or rounding bits, lest we 3545 // take a size -1 of bytes and make it positive. Use an unsigned 3546 // compare, so negative sizes look hugely positive. 3547 int fast_size_limit = FastAllocateSizeLimit; 3548 if (layout_is_con) { 3549 assert(!StressReflectiveCode, "stress mode does not use these paths"); 3550 // Increase the size limit if we have exact knowledge of array type. 3551 int log2_esize = Klass::layout_helper_log2_element_size(layout_con); 3552 fast_size_limit <<= (LogBytesPerLong - log2_esize); 3553 } 3554 3555 Node* initial_slow_cmp = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) ); 3556 Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) ); 3557 if (initial_slow_test->is_Bool()) { 3558 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick. 3559 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn); 3560 } 3561 3562 // --- Size Computation --- 3563 // array_size = round_to_heap(array_header + (length << elem_shift)); 3564 // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes) 3565 // and round_to(x, y) == ((x + y-1) & ~(y-1)) 3566 // The rounding mask is strength-reduced, if possible. 3567 int round_mask = MinObjAlignmentInBytes - 1; 3568 Node* header_size = NULL; 3569 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE); 3570 // (T_BYTE has the weakest alignment and size restrictions...) 3571 if (layout_is_con) { 3572 int hsize = Klass::layout_helper_header_size(layout_con); 3573 int eshift = Klass::layout_helper_log2_element_size(layout_con); 3574 BasicType etype = Klass::layout_helper_element_type(layout_con); 3575 if ((round_mask & ~right_n_bits(eshift)) == 0) 3576 round_mask = 0; // strength-reduce it if it goes away completely 3577 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded"); 3578 assert(header_size_min <= hsize, "generic minimum is smallest"); 3579 header_size_min = hsize; 3580 header_size = intcon(hsize + round_mask); 3581 } else { 3582 Node* hss = intcon(Klass::_lh_header_size_shift); 3583 Node* hsm = intcon(Klass::_lh_header_size_mask); 3584 Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) ); 3585 hsize = _gvn.transform( new(C) AndINode(hsize, hsm) ); 3586 Node* mask = intcon(round_mask); 3587 header_size = _gvn.transform( new(C) AddINode(hsize, mask) ); 3588 } 3589 3590 Node* elem_shift = NULL; 3591 if (layout_is_con) { 3592 int eshift = Klass::layout_helper_log2_element_size(layout_con); 3593 if (eshift != 0) 3594 elem_shift = intcon(eshift); 3595 } else { 3596 // There is no need to mask or shift this value. 3597 // The semantics of LShiftINode include an implicit mask to 0x1F. 3598 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place"); 3599 elem_shift = layout_val; 3600 } 3601 3602 // Transition to native address size for all offset calculations: 3603 Node* lengthx = ConvI2X(length); 3604 Node* headerx = ConvI2X(header_size); 3605 #ifdef _LP64 3606 { const TypeLong* tllen = _gvn.find_long_type(lengthx); 3607 if (tllen != NULL && tllen->_lo < 0) { 3608 // Add a manual constraint to a positive range. Cf. array_element_address. 3609 jlong size_max = arrayOopDesc::max_array_length(T_BYTE); 3610 if (size_max > tllen->_hi) size_max = tllen->_hi; 3611 const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin); 3612 lengthx = _gvn.transform( new (C) ConvI2LNode(length, tlcon)); 3613 } 3614 } 3615 #endif 3616 3617 // Combine header size (plus rounding) and body size. Then round down. 3618 // This computation cannot overflow, because it is used only in two 3619 // places, one where the length is sharply limited, and the other 3620 // after a successful allocation. 3621 Node* abody = lengthx; 3622 if (elem_shift != NULL) 3623 abody = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) ); 3624 Node* size = _gvn.transform( new(C) AddXNode(headerx, abody) ); 3625 if (round_mask != 0) { 3626 Node* mask = MakeConX(~round_mask); 3627 size = _gvn.transform( new(C) AndXNode(size, mask) ); 3628 } 3629 // else if round_mask == 0, the size computation is self-rounding 3630 3631 if (return_size_val != NULL) { 3632 // This is the size 3633 (*return_size_val) = size; 3634 } 3635 3636 // Now generate allocation code 3637 3638 // The entire memory state is needed for slow path of the allocation 3639 // since GC and deoptimization can happened. 3640 Node *mem = reset_memory(); 3641 set_all_memory(mem); // Create new memory state 3642 3643 // Create the AllocateArrayNode and its result projections 3644 AllocateArrayNode* alloc 3645 = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT), 3646 control(), mem, i_o(), 3647 size, klass_node, 3648 initial_slow_test, 3649 length); 3650 3651 // Cast to correct type. Note that the klass_node may be constant or not, 3652 // and in the latter case the actual array type will be inexact also. 3653 // (This happens via a non-constant argument to inline_native_newArray.) 3654 // In any case, the value of klass_node provides the desired array type. 3655 const TypeInt* length_type = _gvn.find_int_type(length); 3656 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type(); 3657 if (ary_type->isa_aryptr() && length_type != NULL) { 3658 // Try to get a better type than POS for the size 3659 ary_type = ary_type->is_aryptr()->cast_to_size(length_type); 3660 } 3661 3662 Node* javaoop = set_output_for_allocation(alloc, ary_type); 3663 3664 // Cast length on remaining path to be as narrow as possible 3665 if (map()->find_edge(length) >= 0) { 3666 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn); 3667 if (ccast != length) { 3668 _gvn.set_type_bottom(ccast); 3669 record_for_igvn(ccast); 3670 replace_in_map(length, ccast); 3671 } 3672 } 3673 3674 return javaoop; 3675 } 3676 3677 // The following "Ideal_foo" functions are placed here because they recognize 3678 // the graph shapes created by the functions immediately above. 3679 3680 //---------------------------Ideal_allocation---------------------------------- 3681 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode. 3682 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) { 3683 if (ptr == NULL) { // reduce dumb test in callers 3684 return NULL; 3685 } 3686 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast 3687 ptr = ptr->in(1); 3688 if (ptr == NULL) return NULL; 3689 } 3690 // Return NULL for allocations with several casts: 3691 // j.l.reflect.Array.newInstance(jobject, jint) 3692 // Object.clone() 3693 // to keep more precise type from last cast. 3694 if (ptr->is_Proj()) { 3695 Node* allo = ptr->in(0); 3696 if (allo != NULL && allo->is_Allocate()) { 3697 return allo->as_Allocate(); 3698 } 3699 } 3700 // Report failure to match. 3701 return NULL; 3702 } 3703 3704 // Fancy version which also strips off an offset (and reports it to caller). 3705 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase, 3706 intptr_t& offset) { 3707 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset); 3708 if (base == NULL) return NULL; 3709 return Ideal_allocation(base, phase); 3710 } 3711 3712 // Trace Initialize <- Proj[Parm] <- Allocate 3713 AllocateNode* InitializeNode::allocation() { 3714 Node* rawoop = in(InitializeNode::RawAddress); 3715 if (rawoop->is_Proj()) { 3716 Node* alloc = rawoop->in(0); 3717 if (alloc->is_Allocate()) { 3718 return alloc->as_Allocate(); 3719 } 3720 } 3721 return NULL; 3722 } 3723 3724 // Trace Allocate -> Proj[Parm] -> Initialize 3725 InitializeNode* AllocateNode::initialization() { 3726 ProjNode* rawoop = proj_out(AllocateNode::RawAddress); 3727 if (rawoop == NULL) return NULL; 3728 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) { 3729 Node* init = rawoop->fast_out(i); 3730 if (init->is_Initialize()) { 3731 assert(init->as_Initialize()->allocation() == this, "2-way link"); 3732 return init->as_Initialize(); 3733 } 3734 } 3735 return NULL; 3736 } 3737 3738 //----------------------------- loop predicates --------------------------- 3739 3740 //------------------------------add_predicate_impl---------------------------- 3741 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) { 3742 // Too many traps seen? 3743 if (too_many_traps(reason)) { 3744 #ifdef ASSERT 3745 if (TraceLoopPredicate) { 3746 int tc = C->trap_count(reason); 3747 tty->print("too many traps=%s tcount=%d in ", 3748 Deoptimization::trap_reason_name(reason), tc); 3749 method()->print(); // which method has too many predicate traps 3750 tty->cr(); 3751 } 3752 #endif 3753 // We cannot afford to take more traps here, 3754 // do not generate predicate. 3755 return; 3756 } 3757 3758 Node *cont = _gvn.intcon(1); 3759 Node* opq = _gvn.transform(new (C) Opaque1Node(C, cont)); 3760 Node *bol = _gvn.transform(new (C) Conv2BNode(opq)); 3761 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN); 3762 Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff)); 3763 C->add_predicate_opaq(opq); 3764 { 3765 PreserveJVMState pjvms(this); 3766 set_control(iffalse); 3767 inc_sp(nargs); 3768 uncommon_trap(reason, Deoptimization::Action_maybe_recompile); 3769 } 3770 Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff)); 3771 set_control(iftrue); 3772 } 3773 3774 //------------------------------add_predicate--------------------------------- 3775 void GraphKit::add_predicate(int nargs) { 3776 if (UseLoopPredicate) { 3777 add_predicate_impl(Deoptimization::Reason_predicate, nargs); 3778 } 3779 // loop's limit check predicate should be near the loop. 3780 if (LoopLimitCheck) { 3781 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs); 3782 } 3783 } 3784 3785 //----------------------------- store barriers ---------------------------- 3786 #define __ ideal. 3787 3788 void GraphKit::sync_kit(IdealKit& ideal) { 3789 set_all_memory(__ merged_memory()); 3790 set_i_o(__ i_o()); 3791 set_control(__ ctrl()); 3792 } 3793 3794 void GraphKit::final_sync(IdealKit& ideal) { 3795 // Final sync IdealKit and graphKit. 3796 sync_kit(ideal); 3797 } 3798 3799 // vanilla/CMS post barrier 3800 // Insert a write-barrier store. This is to let generational GC work; we have 3801 // to flag all oop-stores before the next GC point. 3802 void GraphKit::write_barrier_post(Node* oop_store, 3803 Node* obj, 3804 Node* adr, 3805 uint adr_idx, 3806 Node* val, 3807 bool use_precise) { 3808 // No store check needed if we're storing a NULL or an old object 3809 // (latter case is probably a string constant). The concurrent 3810 // mark sweep garbage collector, however, needs to have all nonNull 3811 // oop updates flagged via card-marks. 3812 if (val != NULL && val->is_Con()) { 3813 // must be either an oop or NULL 3814 const Type* t = val->bottom_type(); 3815 if (t == TypePtr::NULL_PTR || t == Type::TOP) 3816 // stores of null never (?) need barriers 3817 return; 3818 } 3819 3820 if (use_ReduceInitialCardMarks() 3821 && obj == just_allocated_object(control())) { 3822 // We can skip marks on a freshly-allocated object in Eden. 3823 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp. 3824 // That routine informs GC to take appropriate compensating steps, 3825 // upon a slow-path allocation, so as to make this card-mark 3826 // elision safe. 3827 return; 3828 } 3829 3830 if (!use_precise) { 3831 // All card marks for a (non-array) instance are in one place: 3832 adr = obj; 3833 } 3834 // (Else it's an array (or unknown), and we want more precise card marks.) 3835 assert(adr != NULL, ""); 3836 3837 IdealKit ideal(this, true); 3838 3839 // Convert the pointer to an int prior to doing math on it 3840 Node* cast = __ CastPX(__ ctrl(), adr); 3841 3842 // Divide by card size 3843 assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef, 3844 "Only one we handle so far."); 3845 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) ); 3846 3847 // Combine card table base and card offset 3848 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset ); 3849 3850 // Get the alias_index for raw card-mark memory 3851 int adr_type = Compile::AliasIdxRaw; 3852 Node* zero = __ ConI(0); // Dirty card value 3853 BasicType bt = T_BYTE; 3854 3855 if (UseCondCardMark) { 3856 // The classic GC reference write barrier is typically implemented 3857 // as a store into the global card mark table. Unfortunately 3858 // unconditional stores can result in false sharing and excessive 3859 // coherence traffic as well as false transactional aborts. 3860 // UseCondCardMark enables MP "polite" conditional card mark 3861 // stores. In theory we could relax the load from ctrl() to 3862 // no_ctrl, but that doesn't buy much latitude. 3863 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type); 3864 __ if_then(card_val, BoolTest::ne, zero); 3865 } 3866 3867 // Smash zero into card 3868 if( !UseConcMarkSweepGC ) { 3869 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::release); 3870 } else { 3871 // Specialized path for CM store barrier 3872 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type); 3873 } 3874 3875 if (UseCondCardMark) { 3876 __ end_if(); 3877 } 3878 3879 // Final sync IdealKit and GraphKit. 3880 final_sync(ideal); 3881 } 3882 3883 // G1 pre/post barriers 3884 void GraphKit::g1_write_barrier_pre(bool do_load, 3885 Node* obj, 3886 Node* adr, 3887 uint alias_idx, 3888 Node* val, 3889 const TypeOopPtr* val_type, 3890 Node* pre_val, 3891 BasicType bt) { 3892 3893 // Some sanity checks 3894 // Note: val is unused in this routine. 3895 3896 if (do_load) { 3897 // We need to generate the load of the previous value 3898 assert(obj != NULL, "must have a base"); 3899 assert(adr != NULL, "where are loading from?"); 3900 assert(pre_val == NULL, "loaded already?"); 3901 assert(val_type != NULL, "need a type"); 3902 } else { 3903 // In this case both val_type and alias_idx are unused. 3904 assert(pre_val != NULL, "must be loaded already"); 3905 // Nothing to be done if pre_val is null. 3906 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return; 3907 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here"); 3908 } 3909 assert(bt == T_OBJECT, "or we shouldn't be here"); 3910 3911 IdealKit ideal(this, true); 3912 3913 Node* tls = __ thread(); // ThreadLocalStorage 3914 3915 Node* no_ctrl = NULL; 3916 Node* no_base = __ top(); 3917 Node* zero = __ ConI(0); 3918 Node* zeroX = __ ConX(0); 3919 3920 float likely = PROB_LIKELY(0.999); 3921 float unlikely = PROB_UNLIKELY(0.999); 3922 3923 BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE; 3924 assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width"); 3925 3926 // Offsets into the thread 3927 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648 3928 PtrQueue::byte_offset_of_active()); 3929 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656 3930 PtrQueue::byte_offset_of_index()); 3931 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652 3932 PtrQueue::byte_offset_of_buf()); 3933 3934 // Now the actual pointers into the thread 3935 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset)); 3936 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); 3937 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); 3938 3939 // Now some of the values 3940 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw); 3941 3942 // if (!marking) 3943 __ if_then(marking, BoolTest::ne, zero, unlikely); { 3944 BasicType index_bt = TypeX_X->basic_type(); 3945 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size."); 3946 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw); 3947 3948 if (do_load) { 3949 // load original value 3950 // alias_idx correct?? 3951 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx); 3952 } 3953 3954 // if (pre_val != NULL) 3955 __ if_then(pre_val, BoolTest::ne, null()); { 3956 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); 3957 3958 // is the queue for this thread full? 3959 __ if_then(index, BoolTest::ne, zeroX, likely); { 3960 3961 // decrement the index 3962 Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t)))); 3963 3964 // Now get the buffer location we will log the previous value into and store it 3965 Node *log_addr = __ AddP(no_base, buffer, next_index); 3966 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered); 3967 // update the index 3968 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered); 3969 3970 } __ else_(); { 3971 3972 // logging buffer is full, call the runtime 3973 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type(); 3974 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls); 3975 } __ end_if(); // (!index) 3976 } __ end_if(); // (pre_val != NULL) 3977 } __ end_if(); // (!marking) 3978 3979 // Final sync IdealKit and GraphKit. 3980 final_sync(ideal); 3981 } 3982 3983 // 3984 // Update the card table and add card address to the queue 3985 // 3986 void GraphKit::g1_mark_card(IdealKit& ideal, 3987 Node* card_adr, 3988 Node* oop_store, 3989 uint oop_alias_idx, 3990 Node* index, 3991 Node* index_adr, 3992 Node* buffer, 3993 const TypeFunc* tf) { 3994 3995 Node* zero = __ ConI(0); 3996 Node* zeroX = __ ConX(0); 3997 Node* no_base = __ top(); 3998 BasicType card_bt = T_BYTE; 3999 // Smash zero into card. MUST BE ORDERED WRT TO STORE 4000 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw); 4001 4002 // Now do the queue work 4003 __ if_then(index, BoolTest::ne, zeroX); { 4004 4005 Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t)))); 4006 Node* log_addr = __ AddP(no_base, buffer, next_index); 4007 4008 // Order, see storeCM. 4009 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered); 4010 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered); 4011 4012 } __ else_(); { 4013 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread()); 4014 } __ end_if(); 4015 4016 } 4017 4018 void GraphKit::g1_write_barrier_post(Node* oop_store, 4019 Node* obj, 4020 Node* adr, 4021 uint alias_idx, 4022 Node* val, 4023 BasicType bt, 4024 bool use_precise) { 4025 // If we are writing a NULL then we need no post barrier 4026 4027 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) { 4028 // Must be NULL 4029 const Type* t = val->bottom_type(); 4030 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL"); 4031 // No post barrier if writing NULLx 4032 return; 4033 } 4034 4035 if (!use_precise) { 4036 // All card marks for a (non-array) instance are in one place: 4037 adr = obj; 4038 } 4039 // (Else it's an array (or unknown), and we want more precise card marks.) 4040 assert(adr != NULL, ""); 4041 4042 IdealKit ideal(this, true); 4043 4044 Node* tls = __ thread(); // ThreadLocalStorage 4045 4046 Node* no_base = __ top(); 4047 float likely = PROB_LIKELY(0.999); 4048 float unlikely = PROB_UNLIKELY(0.999); 4049 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val()); 4050 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val()); 4051 Node* zeroX = __ ConX(0); 4052 4053 // Get the alias_index for raw card-mark memory 4054 const TypePtr* card_type = TypeRawPtr::BOTTOM; 4055 4056 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type(); 4057 4058 // Offsets into the thread 4059 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() + 4060 PtrQueue::byte_offset_of_index()); 4061 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() + 4062 PtrQueue::byte_offset_of_buf()); 4063 4064 // Pointers into the thread 4065 4066 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); 4067 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); 4068 4069 // Now some values 4070 // Use ctrl to avoid hoisting these values past a safepoint, which could 4071 // potentially reset these fields in the JavaThread. 4072 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw); 4073 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); 4074 4075 // Convert the store obj pointer to an int prior to doing math on it 4076 // Must use ctrl to prevent "integerized oop" existing across safepoint 4077 Node* cast = __ CastPX(__ ctrl(), adr); 4078 4079 // Divide pointer by card size 4080 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) ); 4081 4082 // Combine card table base and card offset 4083 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset ); 4084 4085 // If we know the value being stored does it cross regions? 4086 4087 if (val != NULL) { 4088 // Does the store cause us to cross regions? 4089 4090 // Should be able to do an unsigned compare of region_size instead of 4091 // and extra shift. Do we have an unsigned compare?? 4092 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes); 4093 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes)); 4094 4095 // if (xor_res == 0) same region so skip 4096 __ if_then(xor_res, BoolTest::ne, zeroX); { 4097 4098 // No barrier if we are storing a NULL 4099 __ if_then(val, BoolTest::ne, null(), unlikely); { 4100 4101 // Ok must mark the card if not already dirty 4102 4103 // load the original value of the card 4104 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw); 4105 4106 __ if_then(card_val, BoolTest::ne, young_card); { 4107 sync_kit(ideal); 4108 // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier. 4109 insert_mem_bar(Op_MemBarVolatile, oop_store); 4110 __ sync_kit(this); 4111 4112 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw); 4113 __ if_then(card_val_reload, BoolTest::ne, dirty_card); { 4114 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf); 4115 } __ end_if(); 4116 } __ end_if(); 4117 } __ end_if(); 4118 } __ end_if(); 4119 } else { 4120 // Object.clone() instrinsic uses this path. 4121 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf); 4122 } 4123 4124 // Final sync IdealKit and GraphKit. 4125 final_sync(ideal); 4126 } 4127 #undef __ 4128 4129 4130 4131 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) { 4132 if (java_lang_String::has_offset_field()) { 4133 int offset_offset = java_lang_String::offset_offset_in_bytes(); 4134 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(), 4135 false, NULL, 0); 4136 const TypePtr* offset_field_type = string_type->add_offset(offset_offset); 4137 int offset_field_idx = C->get_alias_index(offset_field_type); 4138 return make_load(ctrl, 4139 basic_plus_adr(str, str, offset_offset), 4140 TypeInt::INT, T_INT, offset_field_idx, MemNode::unordered); 4141 } else { 4142 return intcon(0); 4143 } 4144 } 4145 4146 Node* GraphKit::load_String_length(Node* ctrl, Node* str) { 4147 if (java_lang_String::has_count_field()) { 4148 int count_offset = java_lang_String::count_offset_in_bytes(); 4149 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(), 4150 false, NULL, 0); 4151 const TypePtr* count_field_type = string_type->add_offset(count_offset); 4152 int count_field_idx = C->get_alias_index(count_field_type); 4153 return make_load(ctrl, 4154 basic_plus_adr(str, str, count_offset), 4155 TypeInt::INT, T_INT, count_field_idx, MemNode::unordered); 4156 } else { 4157 return load_array_length(load_String_value(ctrl, str)); 4158 } 4159 } 4160 4161 Node* GraphKit::load_String_value(Node* ctrl, Node* str) { 4162 int value_offset = java_lang_String::value_offset_in_bytes(); 4163 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(), 4164 false, NULL, 0); 4165 const TypePtr* value_field_type = string_type->add_offset(value_offset); 4166 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull, 4167 TypeAry::make(TypeInt::CHAR,TypeInt::POS), 4168 ciTypeArrayKlass::make(T_CHAR), true, 0); 4169 int value_field_idx = C->get_alias_index(value_field_type); 4170 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset), 4171 value_type, T_OBJECT, value_field_idx, MemNode::unordered); 4172 // String.value field is known to be @Stable. 4173 if (UseImplicitStableValues) { 4174 load = cast_array_to_stable(load, value_type); 4175 } 4176 return load; 4177 } 4178 4179 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) { 4180 int offset_offset = java_lang_String::offset_offset_in_bytes(); 4181 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(), 4182 false, NULL, 0); 4183 const TypePtr* offset_field_type = string_type->add_offset(offset_offset); 4184 int offset_field_idx = C->get_alias_index(offset_field_type); 4185 store_to_memory(ctrl, basic_plus_adr(str, offset_offset), 4186 value, T_INT, offset_field_idx, MemNode::unordered); 4187 } 4188 4189 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) { 4190 int value_offset = java_lang_String::value_offset_in_bytes(); 4191 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(), 4192 false, NULL, 0); 4193 const TypePtr* value_field_type = string_type->add_offset(value_offset); 4194 4195 store_oop_to_object(ctrl, str, basic_plus_adr(str, value_offset), value_field_type, 4196 value, TypeAryPtr::CHARS, T_OBJECT, MemNode::unordered); 4197 } 4198 4199 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) { 4200 int count_offset = java_lang_String::count_offset_in_bytes(); 4201 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(), 4202 false, NULL, 0); 4203 const TypePtr* count_field_type = string_type->add_offset(count_offset); 4204 int count_field_idx = C->get_alias_index(count_field_type); 4205 store_to_memory(ctrl, basic_plus_adr(str, count_offset), 4206 value, T_INT, count_field_idx, MemNode::unordered); 4207 } 4208 4209 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) { 4210 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity 4211 // assumption of CCP analysis. 4212 return _gvn.transform(new(C) CastPPNode(ary, ary_type->cast_to_stable(true))); 4213 }