1 /* 2 * Copyright (c) 2009, 2015, 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 "opto/addnode.hpp" 28 #include "opto/callGenerator.hpp" 29 #include "opto/callnode.hpp" 30 #include "opto/divnode.hpp" 31 #include "opto/graphKit.hpp" 32 #include "opto/idealKit.hpp" 33 #include "opto/rootnode.hpp" 34 #include "opto/runtime.hpp" 35 #include "opto/stringopts.hpp" 36 #include "opto/subnode.hpp" 37 #include "runtime/sharedRuntime.hpp" 38 39 #define __ kit. 40 41 class StringConcat : public ResourceObj { 42 private: 43 PhaseStringOpts* _stringopts; 44 Node* _string_alloc; 45 AllocateNode* _begin; // The allocation the begins the pattern 46 CallStaticJavaNode* _end; // The final call of the pattern. Will either be 47 // SB.toString or or String.<init>(SB.toString) 48 bool _multiple; // indicates this is a fusion of two or more 49 // separate StringBuilders 50 51 Node* _arguments; // The list of arguments to be concatenated 52 GrowableArray<int> _mode; // into a String along with a mode flag 53 // indicating how to treat the value. 54 Node_List _constructors; // List of constructors (many in case of stacked concat) 55 Node_List _control; // List of control nodes that will be deleted 56 Node_List _uncommon_traps; // Uncommon traps that needs to be rewritten 57 // to restart at the initial JVMState. 58 59 public: 60 // Mode for converting arguments to Strings 61 enum { 62 StringMode, 63 IntMode, 64 CharMode, 65 StringNullCheckMode 66 }; 67 68 StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end): 69 _end(end), 70 _begin(NULL), 71 _multiple(false), 72 _string_alloc(NULL), 73 _stringopts(stringopts) { 74 _arguments = new Node(1); 75 _arguments->del_req(0); 76 } 77 78 bool validate_mem_flow(); 79 bool validate_control_flow(); 80 81 void merge_add() { 82 #if 0 83 // XXX This is place holder code for reusing an existing String 84 // allocation but the logic for checking the state safety is 85 // probably inadequate at the moment. 86 CallProjections endprojs; 87 sc->end()->extract_projections(&endprojs, false); 88 if (endprojs.resproj != NULL) { 89 for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) { 90 CallStaticJavaNode *use = i.get()->isa_CallStaticJava(); 91 if (use != NULL && use->method() != NULL && 92 use->method()->intrinsic_id() == vmIntrinsics::_String_String && 93 use->in(TypeFunc::Parms + 1) == endprojs.resproj) { 94 // Found useless new String(sb.toString()) so reuse the newly allocated String 95 // when creating the result instead of allocating a new one. 96 sc->set_string_alloc(use->in(TypeFunc::Parms)); 97 sc->set_end(use); 98 } 99 } 100 } 101 #endif 102 } 103 104 StringConcat* merge(StringConcat* other, Node* arg); 105 106 void set_allocation(AllocateNode* alloc) { 107 _begin = alloc; 108 } 109 110 void append(Node* value, int mode) { 111 _arguments->add_req(value); 112 _mode.append(mode); 113 } 114 void push(Node* value, int mode) { 115 _arguments->ins_req(0, value); 116 _mode.insert_before(0, mode); 117 } 118 119 void push_string(Node* value) { 120 push(value, StringMode); 121 } 122 void push_string_null_check(Node* value) { 123 push(value, StringNullCheckMode); 124 } 125 void push_int(Node* value) { 126 push(value, IntMode); 127 } 128 void push_char(Node* value) { 129 push(value, CharMode); 130 } 131 132 static bool is_SB_toString(Node* call) { 133 if (call->is_CallStaticJava()) { 134 CallStaticJavaNode* csj = call->as_CallStaticJava(); 135 ciMethod* m = csj->method(); 136 if (m != NULL && 137 (m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString || 138 m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) { 139 return true; 140 } 141 } 142 return false; 143 } 144 145 static Node* skip_string_null_check(Node* value) { 146 // Look for a diamond shaped Null check of toString() result 147 // (could be code from String.valueOf()): 148 // (Proj == NULL) ? "null":"CastPP(Proj)#NotNULL 149 if (value->is_Phi()) { 150 int true_path = value->as_Phi()->is_diamond_phi(); 151 if (true_path != 0) { 152 // phi->region->if_proj->ifnode->bool 153 BoolNode* b = value->in(0)->in(1)->in(0)->in(1)->as_Bool(); 154 Node* cmp = b->in(1); 155 Node* v1 = cmp->in(1); 156 Node* v2 = cmp->in(2); 157 // Null check of the return of toString which can simply be skipped. 158 if (b->_test._test == BoolTest::ne && 159 v2->bottom_type() == TypePtr::NULL_PTR && 160 value->in(true_path)->Opcode() == Op_CastPP && 161 value->in(true_path)->in(1) == v1 && 162 v1->is_Proj() && is_SB_toString(v1->in(0))) { 163 return v1; 164 } 165 } 166 } 167 return value; 168 } 169 170 Node* argument(int i) { 171 return _arguments->in(i); 172 } 173 Node* argument_uncast(int i) { 174 Node* arg = argument(i); 175 int amode = mode(i); 176 if (amode == StringConcat::StringMode || 177 amode == StringConcat::StringNullCheckMode) { 178 arg = skip_string_null_check(arg); 179 } 180 return arg; 181 } 182 void set_argument(int i, Node* value) { 183 _arguments->set_req(i, value); 184 } 185 int num_arguments() { 186 return _mode.length(); 187 } 188 int mode(int i) { 189 return _mode.at(i); 190 } 191 void add_control(Node* ctrl) { 192 assert(!_control.contains(ctrl), "only push once"); 193 _control.push(ctrl); 194 } 195 void add_constructor(Node* init) { 196 assert(!_constructors.contains(init), "only push once"); 197 _constructors.push(init); 198 } 199 CallStaticJavaNode* end() { return _end; } 200 AllocateNode* begin() { return _begin; } 201 Node* string_alloc() { return _string_alloc; } 202 203 void eliminate_unneeded_control(); 204 void eliminate_initialize(InitializeNode* init); 205 void eliminate_call(CallNode* call); 206 207 void maybe_log_transform() { 208 CompileLog* log = _stringopts->C->log(); 209 if (log != NULL) { 210 log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'", 211 num_arguments(), 212 _string_alloc != NULL, 213 _multiple); 214 JVMState* p = _begin->jvms(); 215 while (p != NULL) { 216 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); 217 p = p->caller(); 218 } 219 log->tail("replace_string_concat"); 220 } 221 } 222 223 void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) { 224 for (uint u = 0; u < _uncommon_traps.size(); u++) { 225 Node* uct = _uncommon_traps.at(u); 226 227 // Build a new call using the jvms state of the allocate 228 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point(); 229 const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type(); 230 const TypePtr* no_memory_effects = NULL; 231 Compile* C = _stringopts->C; 232 CallStaticJavaNode* call = new CallStaticJavaNode(call_type, call_addr, "uncommon_trap", 233 jvms->bci(), no_memory_effects); 234 for (int e = 0; e < TypeFunc::Parms; e++) { 235 call->init_req(e, uct->in(e)); 236 } 237 // Set the trap request to record intrinsic failure if this trap 238 // is taken too many times. Ideally we would handle then traps by 239 // doing the original bookkeeping in the MDO so that if it caused 240 // the code to be thrown out we could still recompile and use the 241 // optimization. Failing the uncommon traps doesn't really mean 242 // that the optimization is a bad idea but there's no other way to 243 // do the MDO updates currently. 244 int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic, 245 Deoptimization::Action_make_not_entrant); 246 call->init_req(TypeFunc::Parms, __ intcon(trap_request)); 247 kit.add_safepoint_edges(call); 248 249 _stringopts->gvn()->transform(call); 250 C->gvn_replace_by(uct, call); 251 uct->disconnect_inputs(NULL, C); 252 } 253 } 254 255 void cleanup() { 256 // disconnect the hook node 257 _arguments->disconnect_inputs(NULL, _stringopts->C); 258 } 259 }; 260 261 262 void StringConcat::eliminate_unneeded_control() { 263 for (uint i = 0; i < _control.size(); i++) { 264 Node* n = _control.at(i); 265 if (n->is_Allocate()) { 266 eliminate_initialize(n->as_Allocate()->initialization()); 267 } 268 if (n->is_Call()) { 269 if (n != _end) { 270 eliminate_call(n->as_Call()); 271 } 272 } else if (n->is_IfTrue()) { 273 Compile* C = _stringopts->C; 274 C->gvn_replace_by(n, n->in(0)->in(0)); 275 // get rid of the other projection 276 C->gvn_replace_by(n->in(0)->as_If()->proj_out(false), C->top()); 277 } 278 } 279 } 280 281 282 StringConcat* StringConcat::merge(StringConcat* other, Node* arg) { 283 StringConcat* result = new StringConcat(_stringopts, _end); 284 for (uint x = 0; x < _control.size(); x++) { 285 Node* n = _control.at(x); 286 if (n->is_Call()) { 287 result->_control.push(n); 288 } 289 } 290 for (uint x = 0; x < other->_control.size(); x++) { 291 Node* n = other->_control.at(x); 292 if (n->is_Call()) { 293 result->_control.push(n); 294 } 295 } 296 assert(result->_control.contains(other->_end), "what?"); 297 assert(result->_control.contains(_begin), "what?"); 298 for (int x = 0; x < num_arguments(); x++) { 299 Node* argx = argument_uncast(x); 300 if (argx == arg) { 301 // replace the toString result with the all the arguments that 302 // made up the other StringConcat 303 for (int y = 0; y < other->num_arguments(); y++) { 304 result->append(other->argument(y), other->mode(y)); 305 } 306 } else { 307 result->append(argx, mode(x)); 308 } 309 } 310 result->set_allocation(other->_begin); 311 for (uint i = 0; i < _constructors.size(); i++) { 312 result->add_constructor(_constructors.at(i)); 313 } 314 for (uint i = 0; i < other->_constructors.size(); i++) { 315 result->add_constructor(other->_constructors.at(i)); 316 } 317 result->_multiple = true; 318 return result; 319 } 320 321 322 void StringConcat::eliminate_call(CallNode* call) { 323 Compile* C = _stringopts->C; 324 CallProjections projs; 325 call->extract_projections(&projs, false); 326 if (projs.fallthrough_catchproj != NULL) { 327 C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control)); 328 } 329 if (projs.fallthrough_memproj != NULL) { 330 C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory)); 331 } 332 if (projs.catchall_memproj != NULL) { 333 C->gvn_replace_by(projs.catchall_memproj, C->top()); 334 } 335 if (projs.fallthrough_ioproj != NULL) { 336 C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O)); 337 } 338 if (projs.catchall_ioproj != NULL) { 339 C->gvn_replace_by(projs.catchall_ioproj, C->top()); 340 } 341 if (projs.catchall_catchproj != NULL) { 342 // EA can't cope with the partially collapsed graph this 343 // creates so put it on the worklist to be collapsed later. 344 for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) { 345 Node *use = i.get(); 346 int opc = use->Opcode(); 347 if (opc == Op_CreateEx || opc == Op_Region) { 348 _stringopts->record_dead_node(use); 349 } 350 } 351 C->gvn_replace_by(projs.catchall_catchproj, C->top()); 352 } 353 if (projs.resproj != NULL) { 354 C->gvn_replace_by(projs.resproj, C->top()); 355 } 356 C->gvn_replace_by(call, C->top()); 357 } 358 359 void StringConcat::eliminate_initialize(InitializeNode* init) { 360 Compile* C = _stringopts->C; 361 362 // Eliminate Initialize node. 363 assert(init->outcnt() <= 2, "only a control and memory projection expected"); 364 assert(init->req() <= InitializeNode::RawStores, "no pending inits"); 365 Node *ctrl_proj = init->proj_out(TypeFunc::Control); 366 if (ctrl_proj != NULL) { 367 C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control)); 368 } 369 Node *mem_proj = init->proj_out(TypeFunc::Memory); 370 if (mem_proj != NULL) { 371 Node *mem = init->in(TypeFunc::Memory); 372 C->gvn_replace_by(mem_proj, mem); 373 } 374 C->gvn_replace_by(init, C->top()); 375 init->disconnect_inputs(NULL, C); 376 } 377 378 Node_List PhaseStringOpts::collect_toString_calls() { 379 Node_List string_calls; 380 Node_List worklist; 381 382 _visited.Clear(); 383 384 // Prime the worklist 385 for (uint i = 1; i < C->root()->len(); i++) { 386 Node* n = C->root()->in(i); 387 if (n != NULL && !_visited.test_set(n->_idx)) { 388 worklist.push(n); 389 } 390 } 391 392 while (worklist.size() > 0) { 393 Node* ctrl = worklist.pop(); 394 if (StringConcat::is_SB_toString(ctrl)) { 395 CallStaticJavaNode* csj = ctrl->as_CallStaticJava(); 396 string_calls.push(csj); 397 } 398 if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) { 399 worklist.push(ctrl->in(0)); 400 } 401 if (ctrl->is_Region()) { 402 for (uint i = 1; i < ctrl->len(); i++) { 403 if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) { 404 worklist.push(ctrl->in(i)); 405 } 406 } 407 } 408 } 409 return string_calls; 410 } 411 412 413 StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) { 414 ciMethod* m = call->method(); 415 ciSymbol* string_sig; 416 ciSymbol* int_sig; 417 ciSymbol* char_sig; 418 if (m->holder() == C->env()->StringBuilder_klass()) { 419 string_sig = ciSymbol::String_StringBuilder_signature(); 420 int_sig = ciSymbol::int_StringBuilder_signature(); 421 char_sig = ciSymbol::char_StringBuilder_signature(); 422 } else if (m->holder() == C->env()->StringBuffer_klass()) { 423 string_sig = ciSymbol::String_StringBuffer_signature(); 424 int_sig = ciSymbol::int_StringBuffer_signature(); 425 char_sig = ciSymbol::char_StringBuffer_signature(); 426 } else { 427 return NULL; 428 } 429 #ifndef PRODUCT 430 if (PrintOptimizeStringConcat) { 431 tty->print("considering toString call in "); 432 call->jvms()->dump_spec(tty); tty->cr(); 433 } 434 #endif 435 436 StringConcat* sc = new StringConcat(this, call); 437 438 AllocateNode* alloc = NULL; 439 InitializeNode* init = NULL; 440 441 // possible opportunity for StringBuilder fusion 442 CallStaticJavaNode* cnode = call; 443 while (cnode) { 444 Node* recv = cnode->in(TypeFunc::Parms)->uncast(); 445 if (recv->is_Proj()) { 446 recv = recv->in(0); 447 } 448 cnode = recv->isa_CallStaticJava(); 449 if (cnode == NULL) { 450 alloc = recv->isa_Allocate(); 451 if (alloc == NULL) { 452 break; 453 } 454 // Find the constructor call 455 Node* result = alloc->result_cast(); 456 if (result == NULL || !result->is_CheckCastPP() || alloc->in(TypeFunc::Memory)->is_top()) { 457 // strange looking allocation 458 #ifndef PRODUCT 459 if (PrintOptimizeStringConcat) { 460 tty->print("giving up because allocation looks strange "); 461 alloc->jvms()->dump_spec(tty); tty->cr(); 462 } 463 #endif 464 break; 465 } 466 Node* constructor = NULL; 467 for (SimpleDUIterator i(result); i.has_next(); i.next()) { 468 CallStaticJavaNode *use = i.get()->isa_CallStaticJava(); 469 if (use != NULL && 470 use->method() != NULL && 471 !use->method()->is_static() && 472 use->method()->name() == ciSymbol::object_initializer_name() && 473 use->method()->holder() == m->holder()) { 474 // Matched the constructor. 475 ciSymbol* sig = use->method()->signature()->as_symbol(); 476 if (sig == ciSymbol::void_method_signature() || 477 sig == ciSymbol::int_void_signature() || 478 sig == ciSymbol::string_void_signature()) { 479 if (sig == ciSymbol::string_void_signature()) { 480 // StringBuilder(String) so pick this up as the first argument 481 assert(use->in(TypeFunc::Parms + 1) != NULL, "what?"); 482 const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1)); 483 if (type == TypePtr::NULL_PTR) { 484 // StringBuilder(null) throws exception. 485 #ifndef PRODUCT 486 if (PrintOptimizeStringConcat) { 487 tty->print("giving up because StringBuilder(null) throws exception"); 488 alloc->jvms()->dump_spec(tty); tty->cr(); 489 } 490 #endif 491 return NULL; 492 } 493 // StringBuilder(str) argument needs null check. 494 sc->push_string_null_check(use->in(TypeFunc::Parms + 1)); 495 } 496 // The int variant takes an initial size for the backing 497 // array so just treat it like the void version. 498 constructor = use; 499 } else { 500 #ifndef PRODUCT 501 if (PrintOptimizeStringConcat) { 502 tty->print("unexpected constructor signature: %s", sig->as_utf8()); 503 } 504 #endif 505 } 506 break; 507 } 508 } 509 if (constructor == NULL) { 510 // couldn't find constructor 511 #ifndef PRODUCT 512 if (PrintOptimizeStringConcat) { 513 tty->print("giving up because couldn't find constructor "); 514 alloc->jvms()->dump_spec(tty); tty->cr(); 515 } 516 #endif 517 break; 518 } 519 520 // Walked all the way back and found the constructor call so see 521 // if this call converted into a direct string concatenation. 522 sc->add_control(call); 523 sc->add_control(constructor); 524 sc->add_control(alloc); 525 sc->set_allocation(alloc); 526 sc->add_constructor(constructor); 527 if (sc->validate_control_flow() && sc->validate_mem_flow()) { 528 return sc; 529 } else { 530 return NULL; 531 } 532 } else if (cnode->method() == NULL) { 533 break; 534 } else if (!cnode->method()->is_static() && 535 cnode->method()->holder() == m->holder() && 536 cnode->method()->name() == ciSymbol::append_name() && 537 (cnode->method()->signature()->as_symbol() == string_sig || 538 cnode->method()->signature()->as_symbol() == char_sig || 539 cnode->method()->signature()->as_symbol() == int_sig)) { 540 sc->add_control(cnode); 541 Node* arg = cnode->in(TypeFunc::Parms + 1); 542 if (cnode->method()->signature()->as_symbol() == int_sig) { 543 sc->push_int(arg); 544 } else if (cnode->method()->signature()->as_symbol() == char_sig) { 545 sc->push_char(arg); 546 } else { 547 if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) { 548 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava(); 549 if (csj->method() != NULL && 550 csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString && 551 arg->outcnt() == 1) { 552 // _control is the list of StringBuilder calls nodes which 553 // will be replaced by new String code after this optimization. 554 // Integer::toString() call is not part of StringBuilder calls 555 // chain. It could be eliminated only if its result is used 556 // only by this SB calls chain. 557 // Another limitation: it should be used only once because 558 // it is unknown that it is used only by this SB calls chain 559 // until all related SB calls nodes are collected. 560 assert(arg->unique_out() == cnode, "sanity"); 561 sc->add_control(csj); 562 sc->push_int(csj->in(TypeFunc::Parms)); 563 continue; 564 } 565 } 566 sc->push_string(arg); 567 } 568 continue; 569 } else { 570 // some unhandled signature 571 #ifndef PRODUCT 572 if (PrintOptimizeStringConcat) { 573 tty->print("giving up because encountered unexpected signature "); 574 cnode->tf()->dump(); tty->cr(); 575 cnode->in(TypeFunc::Parms + 1)->dump(); 576 } 577 #endif 578 break; 579 } 580 } 581 return NULL; 582 } 583 584 585 PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*): 586 Phase(StringOpts), 587 _gvn(gvn), 588 _visited(Thread::current()->resource_area()) { 589 590 assert(OptimizeStringConcat, "shouldn't be here"); 591 592 size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"), 593 ciSymbol::make("[I"), true); 594 if (size_table_field == NULL) { 595 // Something wrong so give up. 596 assert(false, "why can't we find Integer.sizeTable?"); 597 return; 598 } 599 600 // Collect the types needed to talk about the various slices of memory 601 char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS); 602 603 // For each locally allocated StringBuffer see if the usages can be 604 // collapsed into a single String construction. 605 606 // Run through the list of allocation looking for SB.toString to see 607 // if it's possible to fuse the usage of the SB into a single String 608 // construction. 609 GrowableArray<StringConcat*> concats; 610 Node_List toStrings = collect_toString_calls(); 611 while (toStrings.size() > 0) { 612 StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava()); 613 if (sc != NULL) { 614 concats.push(sc); 615 } 616 } 617 618 // try to coalesce separate concats 619 restart: 620 for (int c = 0; c < concats.length(); c++) { 621 StringConcat* sc = concats.at(c); 622 for (int i = 0; i < sc->num_arguments(); i++) { 623 Node* arg = sc->argument_uncast(i); 624 if (arg->is_Proj() && StringConcat::is_SB_toString(arg->in(0))) { 625 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava(); 626 for (int o = 0; o < concats.length(); o++) { 627 if (c == o) continue; 628 StringConcat* other = concats.at(o); 629 if (other->end() == csj) { 630 #ifndef PRODUCT 631 if (PrintOptimizeStringConcat) { 632 tty->print_cr("considering stacked concats"); 633 } 634 #endif 635 636 StringConcat* merged = sc->merge(other, arg); 637 if (merged->validate_control_flow() && merged->validate_mem_flow()) { 638 #ifndef PRODUCT 639 if (PrintOptimizeStringConcat) { 640 tty->print_cr("stacking would succeed"); 641 } 642 #endif 643 if (c < o) { 644 concats.remove_at(o); 645 concats.at_put(c, merged); 646 } else { 647 concats.remove_at(c); 648 concats.at_put(o, merged); 649 } 650 goto restart; 651 } else { 652 #ifndef PRODUCT 653 if (PrintOptimizeStringConcat) { 654 tty->print_cr("stacking would fail"); 655 } 656 #endif 657 } 658 } 659 } 660 } 661 } 662 } 663 664 665 for (int c = 0; c < concats.length(); c++) { 666 StringConcat* sc = concats.at(c); 667 replace_string_concat(sc); 668 } 669 670 remove_dead_nodes(); 671 } 672 673 void PhaseStringOpts::record_dead_node(Node* dead) { 674 dead_worklist.push(dead); 675 } 676 677 void PhaseStringOpts::remove_dead_nodes() { 678 // Delete any dead nodes to make things clean enough that escape 679 // analysis doesn't get unhappy. 680 while (dead_worklist.size() > 0) { 681 Node* use = dead_worklist.pop(); 682 int opc = use->Opcode(); 683 switch (opc) { 684 case Op_Region: { 685 uint i = 1; 686 for (i = 1; i < use->req(); i++) { 687 if (use->in(i) != C->top()) { 688 break; 689 } 690 } 691 if (i >= use->req()) { 692 for (SimpleDUIterator i(use); i.has_next(); i.next()) { 693 Node* m = i.get(); 694 if (m->is_Phi()) { 695 dead_worklist.push(m); 696 } 697 } 698 C->gvn_replace_by(use, C->top()); 699 } 700 break; 701 } 702 case Op_AddP: 703 case Op_CreateEx: { 704 // Recurisvely clean up references to CreateEx so EA doesn't 705 // get unhappy about the partially collapsed graph. 706 for (SimpleDUIterator i(use); i.has_next(); i.next()) { 707 Node* m = i.get(); 708 if (m->is_AddP()) { 709 dead_worklist.push(m); 710 } 711 } 712 C->gvn_replace_by(use, C->top()); 713 break; 714 } 715 case Op_Phi: 716 if (use->in(0) == C->top()) { 717 C->gvn_replace_by(use, C->top()); 718 } 719 break; 720 } 721 } 722 } 723 724 725 bool StringConcat::validate_mem_flow() { 726 Compile* C = _stringopts->C; 727 728 for (uint i = 0; i < _control.size(); i++) { 729 #ifndef PRODUCT 730 Node_List path; 731 #endif 732 Node* curr = _control.at(i); 733 if (curr->is_Call() && curr != _begin) { // For all calls except the first allocation 734 // Now here's the main invariant in our case: 735 // For memory between the constructor, and appends, and toString we should only see bottom memory, 736 // produced by the previous call we know about. 737 if (!_constructors.contains(curr)) { 738 NOT_PRODUCT(path.push(curr);) 739 Node* mem = curr->in(TypeFunc::Memory); 740 assert(mem != NULL, "calls should have memory edge"); 741 assert(!mem->is_Phi(), "should be handled by control flow validation"); 742 NOT_PRODUCT(path.push(mem);) 743 while (mem->is_MergeMem()) { 744 for (uint i = 1; i < mem->req(); i++) { 745 if (i != Compile::AliasIdxBot && mem->in(i) != C->top()) { 746 #ifndef PRODUCT 747 if (PrintOptimizeStringConcat) { 748 tty->print("fusion has incorrect memory flow (side effects) for "); 749 _begin->jvms()->dump_spec(tty); tty->cr(); 750 path.dump(); 751 } 752 #endif 753 return false; 754 } 755 } 756 // skip through a potential MergeMem chain, linked through Bot 757 mem = mem->in(Compile::AliasIdxBot); 758 NOT_PRODUCT(path.push(mem);) 759 } 760 // now let it fall through, and see if we have a projection 761 if (mem->is_Proj()) { 762 // Should point to a previous known call 763 Node *prev = mem->in(0); 764 NOT_PRODUCT(path.push(prev);) 765 if (!prev->is_Call() || !_control.contains(prev)) { 766 #ifndef PRODUCT 767 if (PrintOptimizeStringConcat) { 768 tty->print("fusion has incorrect memory flow (unknown call) for "); 769 _begin->jvms()->dump_spec(tty); tty->cr(); 770 path.dump(); 771 } 772 #endif 773 return false; 774 } 775 } else { 776 assert(mem->is_Store() || mem->is_LoadStore(), "unexpected node type: %s", mem->Name()); 777 #ifndef PRODUCT 778 if (PrintOptimizeStringConcat) { 779 tty->print("fusion has incorrect memory flow (unexpected source) for "); 780 _begin->jvms()->dump_spec(tty); tty->cr(); 781 path.dump(); 782 } 783 #endif 784 return false; 785 } 786 } else { 787 // For memory that feeds into constructors it's more complicated. 788 // However the advantage is that any side effect that happens between the Allocate/Initialize and 789 // the constructor will have to be control-dependent on Initialize. 790 // So we actually don't have to do anything, since it's going to be caught by the control flow 791 // analysis. 792 #ifdef ASSERT 793 // Do a quick verification of the control pattern between the constructor and the initialize node 794 assert(curr->is_Call(), "constructor should be a call"); 795 // Go up the control starting from the constructor call 796 Node* ctrl = curr->in(0); 797 IfNode* iff = NULL; 798 RegionNode* copy = NULL; 799 800 while (true) { 801 // skip known check patterns 802 if (ctrl->is_Region()) { 803 if (ctrl->as_Region()->is_copy()) { 804 copy = ctrl->as_Region(); 805 ctrl = copy->is_copy(); 806 } else { // a cast 807 assert(ctrl->req() == 3 && 808 ctrl->in(1) != NULL && ctrl->in(1)->is_Proj() && 809 ctrl->in(2) != NULL && ctrl->in(2)->is_Proj() && 810 ctrl->in(1)->in(0) == ctrl->in(2)->in(0) && 811 ctrl->in(1)->in(0) != NULL && ctrl->in(1)->in(0)->is_If(), 812 "must be a simple diamond"); 813 Node* true_proj = ctrl->in(1)->is_IfTrue() ? ctrl->in(1) : ctrl->in(2); 814 for (SimpleDUIterator i(true_proj); i.has_next(); i.next()) { 815 Node* use = i.get(); 816 assert(use == ctrl || use->is_ConstraintCast(), 817 "unexpected user: %s", use->Name()); 818 } 819 820 iff = ctrl->in(1)->in(0)->as_If(); 821 ctrl = iff->in(0); 822 } 823 } else if (ctrl->is_IfTrue()) { // null checks, class checks 824 iff = ctrl->in(0)->as_If(); 825 assert(iff->is_If(), "must be if"); 826 // Verify that the other arm is an uncommon trap 827 Node* otherproj = iff->proj_out(1 - ctrl->as_Proj()->_con); 828 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava(); 829 assert(strcmp(call->_name, "uncommon_trap") == 0, "must be uncommond trap"); 830 ctrl = iff->in(0); 831 } else { 832 break; 833 } 834 } 835 836 assert(ctrl->is_Proj(), "must be a projection"); 837 assert(ctrl->in(0)->is_Initialize(), "should be initialize"); 838 for (SimpleDUIterator i(ctrl); i.has_next(); i.next()) { 839 Node* use = i.get(); 840 assert(use == copy || use == iff || use == curr || use->is_CheckCastPP() || use->is_Load(), 841 "unexpected user: %s", use->Name()); 842 } 843 #endif // ASSERT 844 } 845 } 846 } 847 848 #ifndef PRODUCT 849 if (PrintOptimizeStringConcat) { 850 tty->print("fusion has correct memory flow for "); 851 _begin->jvms()->dump_spec(tty); tty->cr(); 852 tty->cr(); 853 } 854 #endif 855 return true; 856 } 857 858 bool StringConcat::validate_control_flow() { 859 // We found all the calls and arguments now lets see if it's 860 // safe to transform the graph as we would expect. 861 862 // Check to see if this resulted in too many uncommon traps previously 863 if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(), 864 Deoptimization::Reason_intrinsic)) { 865 return false; 866 } 867 868 // Walk backwards over the control flow from toString to the 869 // allocation and make sure all the control flow is ok. This 870 // means it's either going to be eliminated once the calls are 871 // removed or it can safely be transformed into an uncommon 872 // trap. 873 874 int null_check_count = 0; 875 Unique_Node_List ctrl_path; 876 877 assert(_control.contains(_begin), "missing"); 878 assert(_control.contains(_end), "missing"); 879 880 // Collect the nodes that we know about and will eliminate into ctrl_path 881 for (uint i = 0; i < _control.size(); i++) { 882 // Push the call and it's control projection 883 Node* n = _control.at(i); 884 if (n->is_Allocate()) { 885 AllocateNode* an = n->as_Allocate(); 886 InitializeNode* init = an->initialization(); 887 ctrl_path.push(init); 888 ctrl_path.push(init->as_Multi()->proj_out(0)); 889 } 890 if (n->is_Call()) { 891 CallNode* cn = n->as_Call(); 892 ctrl_path.push(cn); 893 ctrl_path.push(cn->proj_out(0)); 894 ctrl_path.push(cn->proj_out(0)->unique_out()); 895 if (cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0) != NULL) { 896 ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0)); 897 } 898 } else { 899 ShouldNotReachHere(); 900 } 901 } 902 903 // Skip backwards through the control checking for unexpected control flow 904 Node* ptr = _end; 905 bool fail = false; 906 while (ptr != _begin) { 907 if (ptr->is_Call() && ctrl_path.member(ptr)) { 908 ptr = ptr->in(0); 909 } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) { 910 ptr = ptr->in(0)->in(0)->in(0); 911 assert(ctrl_path.member(ptr), "should be a known piece of control"); 912 } else if (ptr->is_IfTrue()) { 913 IfNode* iff = ptr->in(0)->as_If(); 914 BoolNode* b = iff->in(1)->isa_Bool(); 915 916 if (b == NULL) { 917 fail = true; 918 break; 919 } 920 921 Node* cmp = b->in(1); 922 Node* v1 = cmp->in(1); 923 Node* v2 = cmp->in(2); 924 Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con); 925 926 // Null check of the return of append which can simply be eliminated 927 if (b->_test._test == BoolTest::ne && 928 v2->bottom_type() == TypePtr::NULL_PTR && 929 v1->is_Proj() && ctrl_path.member(v1->in(0))) { 930 // NULL check of the return value of the append 931 null_check_count++; 932 if (otherproj->outcnt() == 1) { 933 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava(); 934 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) { 935 ctrl_path.push(call); 936 } 937 } 938 _control.push(ptr); 939 ptr = ptr->in(0)->in(0); 940 continue; 941 } 942 943 // A test which leads to an uncommon trap which should be safe. 944 // Later this trap will be converted into a trap that restarts 945 // at the beginning. 946 if (otherproj->outcnt() == 1) { 947 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava(); 948 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) { 949 // control flow leads to uct so should be ok 950 _uncommon_traps.push(call); 951 ctrl_path.push(call); 952 ptr = ptr->in(0)->in(0); 953 continue; 954 } 955 } 956 957 #ifndef PRODUCT 958 // Some unexpected control flow we don't know how to handle. 959 if (PrintOptimizeStringConcat) { 960 tty->print_cr("failing with unknown test"); 961 b->dump(); 962 cmp->dump(); 963 v1->dump(); 964 v2->dump(); 965 tty->cr(); 966 } 967 #endif 968 fail = true; 969 break; 970 } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) { 971 ptr = ptr->in(0)->in(0); 972 } else if (ptr->is_Region()) { 973 Node* copy = ptr->as_Region()->is_copy(); 974 if (copy != NULL) { 975 ptr = copy; 976 continue; 977 } 978 if (ptr->req() == 3 && 979 ptr->in(1) != NULL && ptr->in(1)->is_Proj() && 980 ptr->in(2) != NULL && ptr->in(2)->is_Proj() && 981 ptr->in(1)->in(0) == ptr->in(2)->in(0) && 982 ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) { 983 // Simple diamond. 984 // XXX should check for possibly merging stores. simple data merges are ok. 985 // The IGVN will make this simple diamond go away when it 986 // transforms the Region. Make sure it sees it. 987 Compile::current()->record_for_igvn(ptr); 988 ptr = ptr->in(1)->in(0)->in(0); 989 continue; 990 } 991 #ifndef PRODUCT 992 if (PrintOptimizeStringConcat) { 993 tty->print_cr("fusion would fail for region"); 994 _begin->dump(); 995 ptr->dump(2); 996 } 997 #endif 998 fail = true; 999 break; 1000 } else { 1001 // other unknown control 1002 if (!fail) { 1003 #ifndef PRODUCT 1004 if (PrintOptimizeStringConcat) { 1005 tty->print_cr("fusion would fail for"); 1006 _begin->dump(); 1007 } 1008 #endif 1009 fail = true; 1010 } 1011 #ifndef PRODUCT 1012 if (PrintOptimizeStringConcat) { 1013 ptr->dump(); 1014 } 1015 #endif 1016 ptr = ptr->in(0); 1017 } 1018 } 1019 #ifndef PRODUCT 1020 if (PrintOptimizeStringConcat && fail) { 1021 tty->cr(); 1022 } 1023 #endif 1024 if (fail) return !fail; 1025 1026 // Validate that all these results produced are contained within 1027 // this cluster of objects. First collect all the results produced 1028 // by calls in the region. 1029 _stringopts->_visited.Clear(); 1030 Node_List worklist; 1031 Node* final_result = _end->proj_out(TypeFunc::Parms); 1032 for (uint i = 0; i < _control.size(); i++) { 1033 CallNode* cnode = _control.at(i)->isa_Call(); 1034 if (cnode != NULL) { 1035 _stringopts->_visited.test_set(cnode->_idx); 1036 } 1037 Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL; 1038 if (result != NULL && result != final_result) { 1039 worklist.push(result); 1040 } 1041 } 1042 1043 Node* last_result = NULL; 1044 while (worklist.size() > 0) { 1045 Node* result = worklist.pop(); 1046 if (_stringopts->_visited.test_set(result->_idx)) 1047 continue; 1048 for (SimpleDUIterator i(result); i.has_next(); i.next()) { 1049 Node *use = i.get(); 1050 if (ctrl_path.member(use)) { 1051 // already checked this 1052 continue; 1053 } 1054 int opc = use->Opcode(); 1055 if (opc == Op_CmpP || opc == Op_Node) { 1056 ctrl_path.push(use); 1057 continue; 1058 } 1059 if (opc == Op_CastPP || opc == Op_CheckCastPP) { 1060 for (SimpleDUIterator j(use); j.has_next(); j.next()) { 1061 worklist.push(j.get()); 1062 } 1063 worklist.push(use->in(1)); 1064 ctrl_path.push(use); 1065 continue; 1066 } 1067 #ifndef PRODUCT 1068 if (PrintOptimizeStringConcat) { 1069 if (result != last_result) { 1070 last_result = result; 1071 tty->print_cr("extra uses for result:"); 1072 last_result->dump(); 1073 } 1074 use->dump(); 1075 } 1076 #endif 1077 fail = true; 1078 break; 1079 } 1080 } 1081 1082 #ifndef PRODUCT 1083 if (PrintOptimizeStringConcat && !fail) { 1084 ttyLocker ttyl; 1085 tty->cr(); 1086 tty->print("fusion has correct control flow (%d %d) for ", null_check_count, _uncommon_traps.size()); 1087 _begin->jvms()->dump_spec(tty); tty->cr(); 1088 for (int i = 0; i < num_arguments(); i++) { 1089 argument(i)->dump(); 1090 } 1091 _control.dump(); 1092 tty->cr(); 1093 } 1094 #endif 1095 1096 return !fail; 1097 } 1098 1099 Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) { 1100 const TypeInstPtr* mirror_type = TypeInstPtr::make(field->holder()->java_mirror()); 1101 Node* klass_node = __ makecon(mirror_type); 1102 BasicType bt = field->layout_type(); 1103 ciType* field_klass = field->type(); 1104 1105 const Type *type; 1106 if( bt == T_OBJECT ) { 1107 if (!field->type()->is_loaded()) { 1108 type = TypeInstPtr::BOTTOM; 1109 } else if (field->is_constant()) { 1110 // This can happen if the constant oop is non-perm. 1111 ciObject* con = field->constant_value().as_object(); 1112 // Do not "join" in the previous type; it doesn't add value, 1113 // and may yield a vacuous result if the field is of interface type. 1114 type = TypeOopPtr::make_from_constant(con, true)->isa_oopptr(); 1115 assert(type != NULL, "field singleton type must be consistent"); 1116 return __ makecon(type); 1117 } else { 1118 type = TypeOopPtr::make_from_klass(field_klass->as_klass()); 1119 } 1120 } else { 1121 type = Type::get_const_basic_type(bt); 1122 } 1123 1124 return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()), 1125 type, T_OBJECT, 1126 C->get_alias_index(mirror_type->add_offset(field->offset_in_bytes())), 1127 MemNode::unordered); 1128 } 1129 1130 Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) { 1131 RegionNode *final_merge = new RegionNode(3); 1132 kit.gvn().set_type(final_merge, Type::CONTROL); 1133 Node* final_size = new PhiNode(final_merge, TypeInt::INT); 1134 kit.gvn().set_type(final_size, TypeInt::INT); 1135 1136 IfNode* iff = kit.create_and_map_if(kit.control(), 1137 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne), 1138 PROB_FAIR, COUNT_UNKNOWN); 1139 Node* is_min = __ IfFalse(iff); 1140 final_merge->init_req(1, is_min); 1141 final_size->init_req(1, __ intcon(11)); 1142 1143 kit.set_control(__ IfTrue(iff)); 1144 if (kit.stopped()) { 1145 final_merge->init_req(2, C->top()); 1146 final_size->init_req(2, C->top()); 1147 } else { 1148 1149 // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i); 1150 RegionNode *r = new RegionNode(3); 1151 kit.gvn().set_type(r, Type::CONTROL); 1152 Node *phi = new PhiNode(r, TypeInt::INT); 1153 kit.gvn().set_type(phi, TypeInt::INT); 1154 Node *size = new PhiNode(r, TypeInt::INT); 1155 kit.gvn().set_type(size, TypeInt::INT); 1156 Node* chk = __ CmpI(arg, __ intcon(0)); 1157 Node* p = __ Bool(chk, BoolTest::lt); 1158 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN); 1159 Node* lessthan = __ IfTrue(iff); 1160 Node* greaterequal = __ IfFalse(iff); 1161 r->init_req(1, lessthan); 1162 phi->init_req(1, __ SubI(__ intcon(0), arg)); 1163 size->init_req(1, __ intcon(1)); 1164 r->init_req(2, greaterequal); 1165 phi->init_req(2, arg); 1166 size->init_req(2, __ intcon(0)); 1167 kit.set_control(r); 1168 C->record_for_igvn(r); 1169 C->record_for_igvn(phi); 1170 C->record_for_igvn(size); 1171 1172 // for (int i=0; ; i++) 1173 // if (x <= sizeTable[i]) 1174 // return i+1; 1175 1176 // Add loop predicate first. 1177 kit.add_predicate(); 1178 1179 RegionNode *loop = new RegionNode(3); 1180 loop->init_req(1, kit.control()); 1181 kit.gvn().set_type(loop, Type::CONTROL); 1182 1183 Node *index = new PhiNode(loop, TypeInt::INT); 1184 index->init_req(1, __ intcon(0)); 1185 kit.gvn().set_type(index, TypeInt::INT); 1186 kit.set_control(loop); 1187 Node* sizeTable = fetch_static_field(kit, size_table_field); 1188 1189 Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS); 1190 C->record_for_igvn(value); 1191 Node* limit = __ CmpI(phi, value); 1192 Node* limitb = __ Bool(limit, BoolTest::le); 1193 IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN); 1194 Node* lessEqual = __ IfTrue(iff2); 1195 Node* greater = __ IfFalse(iff2); 1196 1197 loop->init_req(2, greater); 1198 index->init_req(2, __ AddI(index, __ intcon(1))); 1199 1200 kit.set_control(lessEqual); 1201 C->record_for_igvn(loop); 1202 C->record_for_igvn(index); 1203 1204 final_merge->init_req(2, kit.control()); 1205 final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1))); 1206 } 1207 1208 kit.set_control(final_merge); 1209 C->record_for_igvn(final_merge); 1210 C->record_for_igvn(final_size); 1211 1212 return final_size; 1213 } 1214 1215 void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) { 1216 RegionNode *final_merge = new RegionNode(4); 1217 kit.gvn().set_type(final_merge, Type::CONTROL); 1218 Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS); 1219 kit.gvn().set_type(final_mem, Type::MEMORY); 1220 1221 // need to handle Integer.MIN_VALUE specially because negating doesn't make it positive 1222 { 1223 // i == MIN_VALUE 1224 IfNode* iff = kit.create_and_map_if(kit.control(), 1225 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne), 1226 PROB_FAIR, COUNT_UNKNOWN); 1227 1228 Node* old_mem = kit.memory(char_adr_idx); 1229 1230 kit.set_control(__ IfFalse(iff)); 1231 if (kit.stopped()) { 1232 // Statically not equal to MIN_VALUE so this path is dead 1233 final_merge->init_req(3, kit.control()); 1234 } else { 1235 copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())), 1236 char_array, start); 1237 final_merge->init_req(3, kit.control()); 1238 final_mem->init_req(3, kit.memory(char_adr_idx)); 1239 } 1240 1241 kit.set_control(__ IfTrue(iff)); 1242 kit.set_memory(old_mem, char_adr_idx); 1243 } 1244 1245 1246 // Simplified version of Integer.getChars 1247 1248 // int q, r; 1249 // int charPos = index; 1250 Node* charPos = end; 1251 1252 // char sign = 0; 1253 1254 Node* i = arg; 1255 Node* sign = __ intcon(0); 1256 1257 // if (i < 0) { 1258 // sign = '-'; 1259 // i = -i; 1260 // } 1261 { 1262 IfNode* iff = kit.create_and_map_if(kit.control(), 1263 __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt), 1264 PROB_FAIR, COUNT_UNKNOWN); 1265 1266 RegionNode *merge = new RegionNode(3); 1267 kit.gvn().set_type(merge, Type::CONTROL); 1268 i = new PhiNode(merge, TypeInt::INT); 1269 kit.gvn().set_type(i, TypeInt::INT); 1270 sign = new PhiNode(merge, TypeInt::INT); 1271 kit.gvn().set_type(sign, TypeInt::INT); 1272 1273 merge->init_req(1, __ IfTrue(iff)); 1274 i->init_req(1, __ SubI(__ intcon(0), arg)); 1275 sign->init_req(1, __ intcon('-')); 1276 merge->init_req(2, __ IfFalse(iff)); 1277 i->init_req(2, arg); 1278 sign->init_req(2, __ intcon(0)); 1279 1280 kit.set_control(merge); 1281 1282 C->record_for_igvn(merge); 1283 C->record_for_igvn(i); 1284 C->record_for_igvn(sign); 1285 } 1286 1287 // for (;;) { 1288 // q = i / 10; 1289 // r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ... 1290 // buf [--charPos] = digits [r]; 1291 // i = q; 1292 // if (i == 0) break; 1293 // } 1294 1295 { 1296 // Add loop predicate first. 1297 kit.add_predicate(); 1298 1299 RegionNode *head = new RegionNode(3); 1300 head->init_req(1, kit.control()); 1301 kit.gvn().set_type(head, Type::CONTROL); 1302 Node *i_phi = new PhiNode(head, TypeInt::INT); 1303 i_phi->init_req(1, i); 1304 kit.gvn().set_type(i_phi, TypeInt::INT); 1305 charPos = PhiNode::make(head, charPos); 1306 kit.gvn().set_type(charPos, TypeInt::INT); 1307 Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS); 1308 kit.gvn().set_type(mem, Type::MEMORY); 1309 kit.set_control(head); 1310 kit.set_memory(mem, char_adr_idx); 1311 1312 Node* q = __ DivI(NULL, i_phi, __ intcon(10)); 1313 Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)), 1314 __ LShiftI(q, __ intcon(1)))); 1315 Node* m1 = __ SubI(charPos, __ intcon(1)); 1316 Node* ch = __ AddI(r, __ intcon('0')); 1317 1318 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR), 1319 ch, T_CHAR, char_adr_idx, MemNode::unordered); 1320 1321 1322 IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne), 1323 PROB_FAIR, COUNT_UNKNOWN); 1324 Node* ne = __ IfTrue(iff); 1325 Node* eq = __ IfFalse(iff); 1326 1327 head->init_req(2, ne); 1328 mem->init_req(2, st); 1329 i_phi->init_req(2, q); 1330 charPos->init_req(2, m1); 1331 1332 charPos = m1; 1333 1334 kit.set_control(eq); 1335 kit.set_memory(st, char_adr_idx); 1336 1337 C->record_for_igvn(head); 1338 C->record_for_igvn(mem); 1339 C->record_for_igvn(i_phi); 1340 C->record_for_igvn(charPos); 1341 } 1342 1343 { 1344 // if (sign != 0) { 1345 // buf [--charPos] = sign; 1346 // } 1347 IfNode* iff = kit.create_and_map_if(kit.control(), 1348 __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne), 1349 PROB_FAIR, COUNT_UNKNOWN); 1350 1351 final_merge->init_req(2, __ IfFalse(iff)); 1352 final_mem->init_req(2, kit.memory(char_adr_idx)); 1353 1354 kit.set_control(__ IfTrue(iff)); 1355 if (kit.stopped()) { 1356 final_merge->init_req(1, C->top()); 1357 final_mem->init_req(1, C->top()); 1358 } else { 1359 Node* m1 = __ SubI(charPos, __ intcon(1)); 1360 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR), 1361 sign, T_CHAR, char_adr_idx, MemNode::unordered); 1362 1363 final_merge->init_req(1, kit.control()); 1364 final_mem->init_req(1, st); 1365 } 1366 1367 kit.set_control(final_merge); 1368 kit.set_memory(final_mem, char_adr_idx); 1369 1370 C->record_for_igvn(final_merge); 1371 C->record_for_igvn(final_mem); 1372 } 1373 } 1374 1375 1376 Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) { 1377 Node* string = str; 1378 Node* offset = kit.load_String_offset(kit.control(), string); 1379 Node* count = kit.load_String_length(kit.control(), string); 1380 Node* value = kit.load_String_value (kit.control(), string); 1381 1382 // copy the contents 1383 if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) { 1384 // For small constant strings just emit individual stores. 1385 // A length of 6 seems like a good space/speed tradeof. 1386 int c = count->get_int(); 1387 int o = offset->get_int(); 1388 const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr(); 1389 ciTypeArray* value_array = t->const_oop()->as_type_array(); 1390 for (int e = 0; e < c; e++) { 1391 __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR), 1392 __ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx, 1393 MemNode::unordered); 1394 start = __ AddI(start, __ intcon(1)); 1395 } 1396 } else { 1397 Node* src_ptr = kit.array_element_address(value, offset, T_CHAR); 1398 Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR); 1399 Node* c = count; 1400 Node* extra = NULL; 1401 #ifdef _LP64 1402 c = __ ConvI2L(c); 1403 extra = C->top(); 1404 #endif 1405 Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP, 1406 OptoRuntime::fast_arraycopy_Type(), 1407 CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()), 1408 "jshort_disjoint_arraycopy", TypeAryPtr::CHARS, 1409 src_ptr, dst_ptr, c, extra); 1410 start = __ AddI(start, count); 1411 } 1412 return start; 1413 } 1414 1415 1416 void PhaseStringOpts::replace_string_concat(StringConcat* sc) { 1417 // Log a little info about the transformation 1418 sc->maybe_log_transform(); 1419 1420 // pull the JVMState of the allocation into a SafePointNode to serve as 1421 // as a shim for the insertion of the new code. 1422 JVMState* jvms = sc->begin()->jvms()->clone_shallow(C); 1423 uint size = sc->begin()->req(); 1424 SafePointNode* map = new SafePointNode(size, jvms); 1425 1426 // copy the control and memory state from the final call into our 1427 // new starting state. This allows any preceeding tests to feed 1428 // into the new section of code. 1429 for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) { 1430 map->init_req(i1, sc->end()->in(i1)); 1431 } 1432 // blow away old allocation arguments 1433 for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) { 1434 map->init_req(i1, C->top()); 1435 } 1436 // Copy the rest of the inputs for the JVMState 1437 for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) { 1438 map->init_req(i1, sc->begin()->in(i1)); 1439 } 1440 // Make sure the memory state is a MergeMem for parsing. 1441 if (!map->in(TypeFunc::Memory)->is_MergeMem()) { 1442 map->set_req(TypeFunc::Memory, MergeMemNode::make(map->in(TypeFunc::Memory))); 1443 } 1444 1445 jvms->set_map(map); 1446 map->ensure_stack(jvms, jvms->method()->max_stack()); 1447 1448 1449 // disconnect all the old StringBuilder calls from the graph 1450 sc->eliminate_unneeded_control(); 1451 1452 // At this point all the old work has been completely removed from 1453 // the graph and the saved JVMState exists at the point where the 1454 // final toString call used to be. 1455 GraphKit kit(jvms); 1456 1457 // There may be uncommon traps which are still using the 1458 // intermediate states and these need to be rewritten to point at 1459 // the JVMState at the beginning of the transformation. 1460 sc->convert_uncommon_traps(kit, jvms); 1461 1462 // Now insert the logic to compute the size of the string followed 1463 // by all the logic to construct array and resulting string. 1464 1465 Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string())); 1466 1467 // Create a region for the overflow checks to merge into. 1468 int args = MAX2(sc->num_arguments(), 1); 1469 RegionNode* overflow = new RegionNode(args); 1470 kit.gvn().set_type(overflow, Type::CONTROL); 1471 1472 // Create a hook node to hold onto the individual sizes since they 1473 // are need for the copying phase. 1474 Node* string_sizes = new Node(args); 1475 1476 Node* length = __ intcon(0); 1477 for (int argi = 0; argi < sc->num_arguments(); argi++) { 1478 Node* arg = sc->argument(argi); 1479 switch (sc->mode(argi)) { 1480 case StringConcat::IntMode: { 1481 Node* string_size = int_stringSize(kit, arg); 1482 1483 // accumulate total 1484 length = __ AddI(length, string_size); 1485 1486 // Cache this value for the use by int_toString 1487 string_sizes->init_req(argi, string_size); 1488 break; 1489 } 1490 case StringConcat::StringNullCheckMode: { 1491 const Type* type = kit.gvn().type(arg); 1492 assert(type != TypePtr::NULL_PTR, "missing check"); 1493 if (!type->higher_equal(TypeInstPtr::NOTNULL)) { 1494 // Null check with uncommont trap since 1495 // StringBuilder(null) throws exception. 1496 // Use special uncommon trap instead of 1497 // calling normal do_null_check(). 1498 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne); 1499 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN); 1500 overflow->add_req(__ IfFalse(iff)); 1501 Node* notnull = __ IfTrue(iff); 1502 kit.set_control(notnull); // set control for the cast_not_null 1503 arg = kit.cast_not_null(arg, false); 1504 sc->set_argument(argi, arg); 1505 } 1506 assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity"); 1507 // Fallthrough to add string length. 1508 } 1509 case StringConcat::StringMode: { 1510 const Type* type = kit.gvn().type(arg); 1511 Node* count = NULL; 1512 if (type == TypePtr::NULL_PTR) { 1513 // replace the argument with the null checked version 1514 arg = null_string; 1515 sc->set_argument(argi, arg); 1516 count = kit.load_String_length(kit.control(), arg); 1517 } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) { 1518 // s = s != null ? s : "null"; 1519 // length = length + (s.count - s.offset); 1520 RegionNode *r = new RegionNode(3); 1521 kit.gvn().set_type(r, Type::CONTROL); 1522 Node *phi = new PhiNode(r, type); 1523 kit.gvn().set_type(phi, phi->bottom_type()); 1524 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne); 1525 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN); 1526 Node* notnull = __ IfTrue(iff); 1527 Node* isnull = __ IfFalse(iff); 1528 kit.set_control(notnull); // set control for the cast_not_null 1529 r->init_req(1, notnull); 1530 phi->init_req(1, kit.cast_not_null(arg, false)); 1531 r->init_req(2, isnull); 1532 phi->init_req(2, null_string); 1533 kit.set_control(r); 1534 C->record_for_igvn(r); 1535 C->record_for_igvn(phi); 1536 // replace the argument with the null checked version 1537 arg = phi; 1538 sc->set_argument(argi, arg); 1539 count = kit.load_String_length(kit.control(), arg); 1540 } else { 1541 // A corresponding nullcheck will be connected during IGVN MemNode::Ideal_common_DU_postCCP 1542 // kit.control might be a different test, that can be hoisted above the actual nullcheck 1543 // in case, that the control input is not null, Ideal_common_DU_postCCP will not look for a nullcheck. 1544 count = kit.load_String_length(NULL, arg); 1545 } 1546 length = __ AddI(length, count); 1547 string_sizes->init_req(argi, NULL); 1548 break; 1549 } 1550 case StringConcat::CharMode: { 1551 // one character only 1552 length = __ AddI(length, __ intcon(1)); 1553 break; 1554 } 1555 default: 1556 ShouldNotReachHere(); 1557 } 1558 if (argi > 0) { 1559 // Check that the sum hasn't overflowed 1560 IfNode* iff = kit.create_and_map_if(kit.control(), 1561 __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt), 1562 PROB_MIN, COUNT_UNKNOWN); 1563 kit.set_control(__ IfFalse(iff)); 1564 overflow->set_req(argi, __ IfTrue(iff)); 1565 } 1566 } 1567 1568 { 1569 // Hook 1570 PreserveJVMState pjvms(&kit); 1571 kit.set_control(overflow); 1572 C->record_for_igvn(overflow); 1573 kit.uncommon_trap(Deoptimization::Reason_intrinsic, 1574 Deoptimization::Action_make_not_entrant); 1575 } 1576 1577 Node* result; 1578 if (!kit.stopped()) { 1579 Node* char_array = NULL; 1580 if (sc->num_arguments() == 1 && 1581 (sc->mode(0) == StringConcat::StringMode || 1582 sc->mode(0) == StringConcat::StringNullCheckMode)) { 1583 // Handle the case when there is only a single String argument. 1584 // In this case, we can just pull the value from the String itself. 1585 char_array = kit.load_String_value(kit.control(), sc->argument(0)); 1586 } else { 1587 // length now contains the number of characters needed for the 1588 // char[] so create a new AllocateArray for the char[] 1589 { 1590 PreserveReexecuteState preexecs(&kit); 1591 // The original jvms is for an allocation of either a String or 1592 // StringBuffer so no stack adjustment is necessary for proper 1593 // reexecution. If we deoptimize in the slow path the bytecode 1594 // will be reexecuted and the char[] allocation will be thrown away. 1595 kit.jvms()->set_should_reexecute(true); 1596 char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))), 1597 length, 1); 1598 } 1599 1600 // Mark the allocation so that zeroing is skipped since the code 1601 // below will overwrite the entire array 1602 AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn); 1603 char_alloc->maybe_set_complete(_gvn); 1604 1605 // Now copy the string representations into the final char[] 1606 Node* start = __ intcon(0); 1607 for (int argi = 0; argi < sc->num_arguments(); argi++) { 1608 Node* arg = sc->argument(argi); 1609 switch (sc->mode(argi)) { 1610 case StringConcat::IntMode: { 1611 Node* end = __ AddI(start, string_sizes->in(argi)); 1612 // getChars words backwards so pass the ending point as well as the start 1613 int_getChars(kit, arg, char_array, start, end); 1614 start = end; 1615 break; 1616 } 1617 case StringConcat::StringNullCheckMode: 1618 case StringConcat::StringMode: { 1619 start = copy_string(kit, arg, char_array, start); 1620 break; 1621 } 1622 case StringConcat::CharMode: { 1623 __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR), 1624 arg, T_CHAR, char_adr_idx, MemNode::unordered); 1625 start = __ AddI(start, __ intcon(1)); 1626 break; 1627 } 1628 default: 1629 ShouldNotReachHere(); 1630 } 1631 } 1632 } 1633 1634 // If we're not reusing an existing String allocation then allocate one here. 1635 result = sc->string_alloc(); 1636 if (result == NULL) { 1637 PreserveReexecuteState preexecs(&kit); 1638 // The original jvms is for an allocation of either a String or 1639 // StringBuffer so no stack adjustment is necessary for proper 1640 // reexecution. 1641 kit.jvms()->set_should_reexecute(true); 1642 result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass()))); 1643 } 1644 1645 // Intialize the string 1646 if (java_lang_String::has_offset_field()) { 1647 kit.store_String_offset(kit.control(), result, __ intcon(0)); 1648 kit.store_String_length(kit.control(), result, length); 1649 } 1650 kit.store_String_value(kit.control(), result, char_array); 1651 } else { 1652 result = C->top(); 1653 } 1654 // hook up the outgoing control and result 1655 kit.replace_call(sc->end(), result); 1656 1657 // Unhook any hook nodes 1658 string_sizes->disconnect_inputs(NULL, C); 1659 sc->cleanup(); 1660 }