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