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 byte_adr_idx = C->get_alias_index(TypeAryPtr::BYTES); 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 if (arg->is_Con()) { 1132 // Constant integer. Compute constant length using Integer.sizeTable 1133 int arg_val = arg->get_int(); 1134 int count = 1; 1135 if (arg_val < 0) { 1136 arg_val = -arg_val; 1137 count++; 1138 } 1139 1140 ciArray* size_table = (ciArray*)size_table_field->constant_value().as_object(); 1141 for (int i = 0; i < size_table->length(); i++) { 1142 if (arg_val <= size_table->element_value(i).as_int()) { 1143 count += i; 1144 break; 1145 } 1146 } 1147 return __ intcon(count); 1148 } 1149 1150 RegionNode *final_merge = new RegionNode(3); 1151 kit.gvn().set_type(final_merge, Type::CONTROL); 1152 Node* final_size = new PhiNode(final_merge, TypeInt::INT); 1153 kit.gvn().set_type(final_size, TypeInt::INT); 1154 1155 IfNode* iff = kit.create_and_map_if(kit.control(), 1156 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne), 1157 PROB_FAIR, COUNT_UNKNOWN); 1158 Node* is_min = __ IfFalse(iff); 1159 final_merge->init_req(1, is_min); 1160 final_size->init_req(1, __ intcon(11)); 1161 1162 kit.set_control(__ IfTrue(iff)); 1163 if (kit.stopped()) { 1164 final_merge->init_req(2, C->top()); 1165 final_size->init_req(2, C->top()); 1166 } else { 1167 1168 // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i); 1169 RegionNode *r = new RegionNode(3); 1170 kit.gvn().set_type(r, Type::CONTROL); 1171 Node *phi = new PhiNode(r, TypeInt::INT); 1172 kit.gvn().set_type(phi, TypeInt::INT); 1173 Node *size = new PhiNode(r, TypeInt::INT); 1174 kit.gvn().set_type(size, TypeInt::INT); 1175 Node* chk = __ CmpI(arg, __ intcon(0)); 1176 Node* p = __ Bool(chk, BoolTest::lt); 1177 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN); 1178 Node* lessthan = __ IfTrue(iff); 1179 Node* greaterequal = __ IfFalse(iff); 1180 r->init_req(1, lessthan); 1181 phi->init_req(1, __ SubI(__ intcon(0), arg)); 1182 size->init_req(1, __ intcon(1)); 1183 r->init_req(2, greaterequal); 1184 phi->init_req(2, arg); 1185 size->init_req(2, __ intcon(0)); 1186 kit.set_control(r); 1187 C->record_for_igvn(r); 1188 C->record_for_igvn(phi); 1189 C->record_for_igvn(size); 1190 1191 // for (int i=0; ; i++) 1192 // if (x <= sizeTable[i]) 1193 // return i+1; 1194 1195 // Add loop predicate first. 1196 kit.add_predicate(); 1197 1198 RegionNode *loop = new RegionNode(3); 1199 loop->init_req(1, kit.control()); 1200 kit.gvn().set_type(loop, Type::CONTROL); 1201 1202 Node *index = new PhiNode(loop, TypeInt::INT); 1203 index->init_req(1, __ intcon(0)); 1204 kit.gvn().set_type(index, TypeInt::INT); 1205 kit.set_control(loop); 1206 Node* sizeTable = fetch_static_field(kit, size_table_field); 1207 1208 Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS); 1209 C->record_for_igvn(value); 1210 Node* limit = __ CmpI(phi, value); 1211 Node* limitb = __ Bool(limit, BoolTest::le); 1212 IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN); 1213 Node* lessEqual = __ IfTrue(iff2); 1214 Node* greater = __ IfFalse(iff2); 1215 1216 loop->init_req(2, greater); 1217 index->init_req(2, __ AddI(index, __ intcon(1))); 1218 1219 kit.set_control(lessEqual); 1220 C->record_for_igvn(loop); 1221 C->record_for_igvn(index); 1222 1223 final_merge->init_req(2, kit.control()); 1224 final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1))); 1225 } 1226 1227 kit.set_control(final_merge); 1228 C->record_for_igvn(final_merge); 1229 C->record_for_igvn(final_size); 1230 1231 return final_size; 1232 } 1233 1234 // Simplified version of Integer.getChars 1235 void PhaseStringOpts::getChars(GraphKit& kit, Node* arg, Node* dst_array, BasicType bt, Node* end, Node* final_merge, Node* final_mem, int merge_index) { 1236 // if (i < 0) { 1237 // sign = '-'; 1238 // i = -i; 1239 // } 1240 IfNode* iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt), 1241 PROB_FAIR, COUNT_UNKNOWN); 1242 1243 RegionNode* merge = new RegionNode(3); 1244 kit.gvn().set_type(merge, Type::CONTROL); 1245 Node* i = new PhiNode(merge, TypeInt::INT); 1246 kit.gvn().set_type(i, TypeInt::INT); 1247 Node* sign = new PhiNode(merge, TypeInt::INT); 1248 kit.gvn().set_type(sign, TypeInt::INT); 1249 1250 merge->init_req(1, __ IfTrue(iff)); 1251 i->init_req(1, __ SubI(__ intcon(0), arg)); 1252 sign->init_req(1, __ intcon('-')); 1253 merge->init_req(2, __ IfFalse(iff)); 1254 i->init_req(2, arg); 1255 sign->init_req(2, __ intcon(0)); 1256 1257 kit.set_control(merge); 1258 1259 C->record_for_igvn(merge); 1260 C->record_for_igvn(i); 1261 C->record_for_igvn(sign); 1262 1263 // for (;;) { 1264 // q = i / 10; 1265 // r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ... 1266 // buf [--charPos] = digits [r]; 1267 // i = q; 1268 // if (i == 0) break; 1269 // } 1270 1271 // Add loop predicate first. 1272 kit.add_predicate(); 1273 1274 RegionNode* head = new RegionNode(3); 1275 head->init_req(1, kit.control()); 1276 1277 kit.gvn().set_type(head, Type::CONTROL); 1278 Node* i_phi = new PhiNode(head, TypeInt::INT); 1279 i_phi->init_req(1, i); 1280 kit.gvn().set_type(i_phi, TypeInt::INT); 1281 Node* charPos = new PhiNode(head, TypeInt::INT); 1282 charPos->init_req(1, end); 1283 kit.gvn().set_type(charPos, TypeInt::INT); 1284 Node* mem = PhiNode::make(head, kit.memory(byte_adr_idx), Type::MEMORY, TypeAryPtr::BYTES); 1285 kit.gvn().set_type(mem, Type::MEMORY); 1286 1287 kit.set_control(head); 1288 kit.set_memory(mem, byte_adr_idx); 1289 1290 Node* q = __ DivI(kit.null(), i_phi, __ intcon(10)); 1291 Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)), 1292 __ LShiftI(q, __ intcon(1)))); 1293 Node* index = __ SubI(charPos, __ intcon((bt == T_BYTE) ? 1 : 2)); 1294 Node* ch = __ AddI(r, __ intcon('0')); 1295 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(dst_array, index, T_BYTE), 1296 ch, bt, byte_adr_idx, MemNode::unordered); 1297 1298 iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne), 1299 PROB_FAIR, COUNT_UNKNOWN); 1300 Node* ne = __ IfTrue(iff); 1301 Node* eq = __ IfFalse(iff); 1302 1303 head->init_req(2, ne); 1304 mem->init_req(2, st); 1305 1306 i_phi->init_req(2, q); 1307 charPos->init_req(2, index); 1308 charPos = index; 1309 1310 kit.set_control(eq); 1311 kit.set_memory(st, byte_adr_idx); 1312 1313 C->record_for_igvn(head); 1314 C->record_for_igvn(mem); 1315 C->record_for_igvn(i_phi); 1316 C->record_for_igvn(charPos); 1317 1318 // if (sign != 0) { 1319 // buf [--charPos] = sign; 1320 // } 1321 iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne), 1322 PROB_FAIR, COUNT_UNKNOWN); 1323 1324 final_merge->init_req(merge_index + 2, __ IfFalse(iff)); 1325 final_mem->init_req(merge_index + 2, kit.memory(byte_adr_idx)); 1326 1327 kit.set_control(__ IfTrue(iff)); 1328 if (kit.stopped()) { 1329 final_merge->init_req(merge_index + 1, C->top()); 1330 final_mem->init_req(merge_index + 1, C->top()); 1331 } else { 1332 Node* index = __ SubI(charPos, __ intcon((bt == T_BYTE) ? 1 : 2)); 1333 st = __ store_to_memory(kit.control(), kit.array_element_address(dst_array, index, T_BYTE), 1334 sign, bt, byte_adr_idx, MemNode::unordered); 1335 1336 final_merge->init_req(merge_index + 1, kit.control()); 1337 final_mem->init_req(merge_index + 1, st); 1338 } 1339 } 1340 1341 // Copy the characters representing arg into dst_array starting at start 1342 Node* PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* dst_array, Node* dst_coder, Node* start, Node* size) { 1343 bool dcon = dst_coder->is_Con(); 1344 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false; 1345 Node* end = __ AddI(start, __ LShiftI(size, dst_coder)); 1346 1347 // The final_merge node has 4 entries in case the encoding is known: 1348 // (0) Control, (1) result w/ sign, (2) result w/o sign, (3) result for Integer.min_value 1349 // or 6 entries in case the encoding is not known: 1350 // (0) Control, (1) Latin1 w/ sign, (2) Latin1 w/o sign, (3) min_value, (4) UTF16 w/ sign, (5) UTF16 w/o sign 1351 RegionNode* final_merge = new RegionNode(dcon ? 4 : 6); 1352 kit.gvn().set_type(final_merge, Type::CONTROL); 1353 1354 Node* final_mem = PhiNode::make(final_merge, kit.memory(byte_adr_idx), Type::MEMORY, TypeAryPtr::BYTES); 1355 kit.gvn().set_type(final_mem, Type::MEMORY); 1356 1357 // need to handle arg == Integer.MIN_VALUE specially because negating doesn't make it positive 1358 IfNode* iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne), 1359 PROB_FAIR, COUNT_UNKNOWN); 1360 1361 Node* old_mem = kit.memory(byte_adr_idx); 1362 1363 kit.set_control(__ IfFalse(iff)); 1364 if (kit.stopped()) { 1365 // Statically not equal to MIN_VALUE so this path is dead 1366 final_merge->init_req(3, kit.control()); 1367 } else { 1368 copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())), 1369 dst_array, dst_coder, start); 1370 final_merge->init_req(3, kit.control()); 1371 final_mem->init_req(3, kit.memory(byte_adr_idx)); 1372 } 1373 1374 kit.set_control(__ IfTrue(iff)); 1375 kit.set_memory(old_mem, byte_adr_idx); 1376 1377 if (!dcon) { 1378 // Check encoding of destination 1379 iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(dst_coder, __ intcon(0)), BoolTest::eq), 1380 PROB_FAIR, COUNT_UNKNOWN); 1381 old_mem = kit.memory(byte_adr_idx); 1382 } 1383 if (!dcon || dbyte) { 1384 // Destination is Latin1, 1385 if (!dcon) { 1386 kit.set_control(__ IfTrue(iff)); 1387 } 1388 getChars(kit, arg, dst_array, T_BYTE, end, final_merge, final_mem); 1389 } 1390 if (!dcon || !dbyte) { 1391 // Destination is UTF16 1392 int merge_index = 0; 1393 if (!dcon) { 1394 kit.set_control(__ IfFalse(iff)); 1395 kit.set_memory(old_mem, byte_adr_idx); 1396 merge_index = 3; // Account for Latin1 case 1397 } 1398 getChars(kit, arg, dst_array, T_CHAR, end, final_merge, final_mem, merge_index); 1399 } 1400 1401 // Final merge point for Latin1 and UTF16 case 1402 kit.set_control(final_merge); 1403 kit.set_memory(final_mem, byte_adr_idx); 1404 1405 C->record_for_igvn(final_merge); 1406 C->record_for_igvn(final_mem); 1407 return end; 1408 } 1409 1410 // Copy 'count' bytes/chars from src_array to dst_array starting at index start 1411 void PhaseStringOpts::arraycopy(GraphKit& kit, IdealKit& ideal, Node* src_array, Node* dst_array, BasicType elembt, Node* start, Node* count) { 1412 assert(elembt == T_BYTE || elembt == T_CHAR, "Invalid type for arraycopy"); 1413 1414 if (elembt == T_CHAR) { 1415 // Get number of chars 1416 count = __ RShiftI(count, __ intcon(1)); 1417 } 1418 1419 Node* extra = NULL; 1420 #ifdef _LP64 1421 count = __ ConvI2L(count); 1422 extra = C->top(); 1423 #endif 1424 1425 Node* src_ptr = __ array_element_address(src_array, __ intcon(0), T_BYTE); 1426 Node* dst_ptr = __ array_element_address(dst_array, start, T_BYTE); 1427 // Check if destination address is aligned to HeapWordSize 1428 const TypeInt* tdst = __ gvn().type(start)->is_int(); 1429 bool aligned = tdst->is_con() && ((tdst->get_con() * type2aelembytes(T_BYTE)) % HeapWordSize == 0); 1430 // Figure out which arraycopy runtime method to call (disjoint, uninitialized). 1431 const char* copyfunc_name = "arraycopy"; 1432 address copyfunc_addr = StubRoutines::select_arraycopy_function(elembt, aligned, true, copyfunc_name, true); 1433 ideal.make_leaf_call_no_fp(OptoRuntime::fast_arraycopy_Type(), copyfunc_addr, copyfunc_name, 1434 TypeAryPtr::BYTES, src_ptr, dst_ptr, count, extra); 1435 } 1436 1437 #undef __ 1438 #define __ ideal. 1439 1440 // Copy contents of a Latin1 encoded string from src_array to dst_array 1441 void PhaseStringOpts::copy_latin1_string(GraphKit& kit, IdealKit& ideal, Node* src_array, IdealVariable& count, 1442 Node* dst_array, Node* dst_coder, Node* start) { 1443 bool dcon = dst_coder->is_Con(); 1444 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false; 1445 1446 if (!dcon) { 1447 __ if_then(dst_coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1)); 1448 } 1449 if (!dcon || dbyte) { 1450 // Destination is Latin1. Simply emit a byte arraycopy. 1451 arraycopy(kit, ideal, src_array, dst_array, T_BYTE, start, __ value(count)); 1452 } 1453 if (!dcon) { 1454 __ else_(); 1455 } 1456 if (!dcon || !dbyte) { 1457 // Destination is UTF16. Inflate src_array into dst_array. 1458 kit.sync_kit(ideal); 1459 if (Matcher::match_rule_supported(Op_StrInflatedCopy)) { 1460 // Use fast intrinsic 1461 Node* src = kit.array_element_address(src_array, kit.intcon(0), T_BYTE); 1462 Node* dst = kit.array_element_address(dst_array, start, T_BYTE); 1463 kit.inflate_string(src, dst, __ value(count)); 1464 } else { 1465 // No intrinsic available, use slow method 1466 kit.inflate_string_slow(src_array, dst_array, start, __ value(count)); 1467 } 1468 ideal.sync_kit(&kit); 1469 // Multiply count by two since we now need two bytes per char 1470 __ set(count, __ LShiftI(__ value(count), __ ConI(1))); 1471 } 1472 if (!dcon) { 1473 __ end_if(); 1474 } 1475 } 1476 1477 // Read two bytes from index and index+1 and convert them to a char 1478 static jchar readChar(ciTypeArray* array, int index) { 1479 int shift_high, shift_low; 1480 #ifdef VM_LITTLE_ENDIAN 1481 shift_high = 0; 1482 shift_low = 8; 1483 #else 1484 shift_high = 8; 1485 shift_low = 0; 1486 #endif 1487 1488 jchar b1 = ((jchar) array->byte_at(index)) & 0xff; 1489 jchar b2 = ((jchar) array->byte_at(index+1)) & 0xff; 1490 return (b1 << shift_high) | (b2 << shift_low); 1491 } 1492 1493 // Copy contents of constant src_array to dst_array by emitting individual stores 1494 void PhaseStringOpts::copy_constant_string(GraphKit& kit, IdealKit& ideal, ciTypeArray* src_array, IdealVariable& count, 1495 bool src_is_byte, Node* dst_array, Node* dst_coder, Node* start) { 1496 bool dcon = dst_coder->is_Con(); 1497 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false; 1498 int length = src_array->length(); 1499 1500 if (!dcon) { 1501 __ if_then(dst_coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1)); 1502 } 1503 if (!dcon || dbyte) { 1504 // Destination is Latin1. Copy each byte of src_array into dst_array. 1505 Node* index = start; 1506 for (int i = 0; i < length; i++) { 1507 Node* adr = kit.array_element_address(dst_array, index, T_BYTE); 1508 Node* val = __ ConI(src_array->byte_at(i)); 1509 __ store(__ ctrl(), adr, val, T_BYTE, byte_adr_idx, MemNode::unordered); 1510 index = __ AddI(index, __ ConI(1)); 1511 } 1512 } 1513 if (!dcon) { 1514 __ else_(); 1515 } 1516 if (!dcon || !dbyte) { 1517 // Destination is UTF16. Copy each char of src_array into dst_array. 1518 Node* index = start; 1519 for (int i = 0; i < length; i++) { 1520 Node* adr = kit.array_element_address(dst_array, index, T_BYTE); 1521 jchar val; 1522 if (src_is_byte) { 1523 val = src_array->byte_at(i); 1524 } else { 1525 val = readChar(src_array, i++); 1526 } 1527 __ store(__ ctrl(), adr, __ ConI(val), T_CHAR, byte_adr_idx, MemNode::unordered); 1528 index = __ AddI(index, __ ConI(2)); 1529 } 1530 if (src_is_byte) { 1531 // Multiply count by two since we now need two bytes per char 1532 __ set(count, __ ConI(2 * length)); 1533 } 1534 } 1535 if (!dcon) { 1536 __ end_if(); 1537 } 1538 } 1539 1540 // Compress copy contents of the byte/char String str into dst_array starting at index start. 1541 Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* dst_array, Node* dst_coder, Node* start) { 1542 Node* src_array = kit.load_String_value(kit.control(), str); 1543 1544 IdealKit ideal(&kit, true, true); 1545 IdealVariable count(ideal); __ declarations_done(); 1546 1547 if (str->is_Con()) { 1548 // Constant source string 1549 const TypeOopPtr* t = kit.gvn().type(src_array)->isa_oopptr(); 1550 ciTypeArray* src_array_type = t->const_oop()->as_type_array(); 1551 1552 // Check encoding of constant string 1553 bool src_is_byte = (get_constant_coder(kit, str) == java_lang_String::CODER_LATIN1); 1554 1555 // For small constant strings just emit individual stores. 1556 // A length of 6 seems like a good space/speed tradeof. 1557 __ set(count, __ ConI(src_array_type->length())); 1558 int src_len = src_array_type->length() / (src_is_byte ? 1 : 2); 1559 if (src_len < unroll_string_copy_length) { 1560 // Small constant string 1561 copy_constant_string(kit, ideal, src_array_type, count, src_is_byte, dst_array, dst_coder, start); 1562 } else if (src_is_byte) { 1563 // Source is Latin1 1564 copy_latin1_string(kit, ideal, src_array, count, dst_array, dst_coder, start); 1565 } else { 1566 // Source is UTF16 (destination too). Simply emit a char arraycopy. 1567 arraycopy(kit, ideal, src_array, dst_array, T_CHAR, start, __ value(count)); 1568 } 1569 } else { 1570 Node* size = kit.load_array_length(src_array); 1571 __ set(count, size); 1572 // Non-constant source string 1573 if (CompactStrings) { 1574 // Emit runtime check for coder 1575 Node* coder = kit.load_String_coder(__ ctrl(), str); 1576 __ if_then(coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1)); { 1577 // Source is Latin1 1578 copy_latin1_string(kit, ideal, src_array, count, dst_array, dst_coder, start); 1579 } __ else_(); 1580 } 1581 // Source is UTF16 (destination too). Simply emit a char arraycopy. 1582 arraycopy(kit, ideal, src_array, dst_array, T_CHAR, start, __ value(count)); 1583 1584 if (CompactStrings) { 1585 __ end_if(); 1586 } 1587 } 1588 1589 // Finally sync IdealKit and GraphKit. 1590 kit.sync_kit(ideal); 1591 return __ AddI(start, __ value(count)); 1592 } 1593 1594 // Compress copy the char into dst_array at index start. 1595 Node* PhaseStringOpts::copy_char(GraphKit& kit, Node* val, Node* dst_array, Node* dst_coder, Node* start) { 1596 bool dcon = (dst_coder != NULL) && dst_coder->is_Con(); 1597 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false; 1598 1599 IdealKit ideal(&kit, true, true); 1600 IdealVariable end(ideal); __ declarations_done(); 1601 Node* adr = kit.array_element_address(dst_array, start, T_BYTE); 1602 if (!dcon){ 1603 __ if_then(dst_coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1)); 1604 } 1605 if (!dcon || dbyte) { 1606 // Destination is Latin1. Store a byte. 1607 __ store(__ ctrl(), adr, val, T_BYTE, byte_adr_idx, MemNode::unordered); 1608 __ set(end, __ AddI(start, __ ConI(1))); 1609 } 1610 if (!dcon) { 1611 __ else_(); 1612 } 1613 if (!dcon || !dbyte) { 1614 // Destination is UTF16. Store a char. 1615 __ store(__ ctrl(), adr, val, T_CHAR, byte_adr_idx, MemNode::unordered); 1616 __ set(end, __ AddI(start, __ ConI(2))); 1617 } 1618 if (!dcon) { 1619 __ end_if(); 1620 } 1621 // Finally sync IdealKit and GraphKit. 1622 kit.sync_kit(ideal); 1623 return __ value(end); 1624 } 1625 1626 #undef __ 1627 #define __ kit. 1628 1629 // Allocate a byte array of specified length. 1630 Node* PhaseStringOpts::allocate_byte_array(GraphKit& kit, IdealKit* ideal, Node* length) { 1631 if (ideal != NULL) { 1632 // Sync IdealKit and graphKit. 1633 kit.sync_kit(*ideal); 1634 } 1635 Node* byte_array = NULL; 1636 { 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. If we deoptimize in the slow path the bytecode 1641 // will be reexecuted and the char[] allocation will be thrown away. 1642 kit.jvms()->set_should_reexecute(true); 1643 byte_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_BYTE))), 1644 length, 1); 1645 } 1646 1647 // Mark the allocation so that zeroing is skipped since the code 1648 // below will overwrite the entire array 1649 AllocateArrayNode* byte_alloc = AllocateArrayNode::Ideal_array_allocation(byte_array, _gvn); 1650 byte_alloc->maybe_set_complete(_gvn); 1651 1652 if (ideal != NULL) { 1653 // Sync IdealKit and graphKit. 1654 ideal->sync_kit(&kit); 1655 } 1656 return byte_array; 1657 } 1658 1659 jbyte PhaseStringOpts::get_constant_coder(GraphKit& kit, Node* str) { 1660 assert(str->is_Con(), "String must be constant"); 1661 const TypeOopPtr* str_type = kit.gvn().type(str)->isa_oopptr(); 1662 ciInstance* str_instance = str_type->const_oop()->as_instance(); 1663 jbyte coder = str_instance->field_value_by_offset(java_lang_String::coder_offset_in_bytes()).as_byte(); 1664 assert(CompactStrings || (coder == java_lang_String::CODER_UTF16), "Strings must be UTF16 encoded"); 1665 return coder; 1666 } 1667 1668 int PhaseStringOpts::get_constant_length(GraphKit& kit, Node* str) { 1669 assert(str->is_Con(), "String must be constant"); 1670 Node* src_array = kit.load_String_value(kit.control(), str); 1671 const TypeOopPtr* t = kit.gvn().type(src_array)->isa_oopptr(); 1672 return t->const_oop()->as_type_array()->length(); 1673 } 1674 1675 void PhaseStringOpts::replace_string_concat(StringConcat* sc) { 1676 // Log a little info about the transformation 1677 sc->maybe_log_transform(); 1678 1679 // pull the JVMState of the allocation into a SafePointNode to serve as 1680 // as a shim for the insertion of the new code. 1681 JVMState* jvms = sc->begin()->jvms()->clone_shallow(C); 1682 uint size = sc->begin()->req(); 1683 SafePointNode* map = new SafePointNode(size, jvms); 1684 1685 // copy the control and memory state from the final call into our 1686 // new starting state. This allows any preceeding tests to feed 1687 // into the new section of code. 1688 for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) { 1689 map->init_req(i1, sc->end()->in(i1)); 1690 } 1691 // blow away old allocation arguments 1692 for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) { 1693 map->init_req(i1, C->top()); 1694 } 1695 // Copy the rest of the inputs for the JVMState 1696 for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) { 1697 map->init_req(i1, sc->begin()->in(i1)); 1698 } 1699 // Make sure the memory state is a MergeMem for parsing. 1700 if (!map->in(TypeFunc::Memory)->is_MergeMem()) { 1701 map->set_req(TypeFunc::Memory, MergeMemNode::make(map->in(TypeFunc::Memory))); 1702 } 1703 1704 jvms->set_map(map); 1705 map->ensure_stack(jvms, jvms->method()->max_stack()); 1706 1707 // disconnect all the old StringBuilder calls from the graph 1708 sc->eliminate_unneeded_control(); 1709 1710 // At this point all the old work has been completely removed from 1711 // the graph and the saved JVMState exists at the point where the 1712 // final toString call used to be. 1713 GraphKit kit(jvms); 1714 1715 // There may be uncommon traps which are still using the 1716 // intermediate states and these need to be rewritten to point at 1717 // the JVMState at the beginning of the transformation. 1718 sc->convert_uncommon_traps(kit, jvms); 1719 1720 // Now insert the logic to compute the size of the string followed 1721 // by all the logic to construct array and resulting string. 1722 1723 Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string())); 1724 1725 // Create a region for the overflow checks to merge into. 1726 int args = MAX2(sc->num_arguments(), 1); 1727 RegionNode* overflow = new RegionNode(args); 1728 kit.gvn().set_type(overflow, Type::CONTROL); 1729 1730 // Create a hook node to hold onto the individual sizes since they 1731 // are need for the copying phase. 1732 Node* string_sizes = new Node(args); 1733 1734 Node* coder = __ intcon(0); 1735 Node* length = __ intcon(0); 1736 // If at least one argument is UTF16 encoded, we can fix the encoding. 1737 bool coder_fixed = false; 1738 1739 if (!CompactStrings) { 1740 // Fix encoding of result string to UTF16 1741 coder_fixed = true; 1742 coder = __ intcon(java_lang_String::CODER_UTF16); 1743 } 1744 1745 for (int argi = 0; argi < sc->num_arguments(); argi++) { 1746 Node* arg = sc->argument(argi); 1747 switch (sc->mode(argi)) { 1748 case StringConcat::IntMode: { 1749 Node* string_size = int_stringSize(kit, arg); 1750 1751 // accumulate total 1752 length = __ AddI(length, string_size); 1753 1754 // Cache this value for the use by int_toString 1755 string_sizes->init_req(argi, string_size); 1756 break; 1757 } 1758 case StringConcat::StringNullCheckMode: { 1759 const Type* type = kit.gvn().type(arg); 1760 assert(type != TypePtr::NULL_PTR, "missing check"); 1761 if (!type->higher_equal(TypeInstPtr::NOTNULL)) { 1762 // Null check with uncommon trap since 1763 // StringBuilder(null) throws exception. 1764 // Use special uncommon trap instead of 1765 // calling normal do_null_check(). 1766 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne); 1767 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN); 1768 overflow->add_req(__ IfFalse(iff)); 1769 Node* notnull = __ IfTrue(iff); 1770 kit.set_control(notnull); // set control for the cast_not_null 1771 arg = kit.cast_not_null(arg, false); 1772 sc->set_argument(argi, arg); 1773 } 1774 assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity"); 1775 // Fallthrough to add string length. 1776 } 1777 case StringConcat::StringMode: { 1778 const Type* type = kit.gvn().type(arg); 1779 Node* count = NULL; 1780 Node* arg_coder = NULL; 1781 if (type == TypePtr::NULL_PTR) { 1782 // replace the argument with the null checked version 1783 arg = null_string; 1784 sc->set_argument(argi, arg); 1785 count = kit.load_String_length(kit.control(), arg); 1786 arg_coder = kit.load_String_coder(kit.control(), arg); 1787 } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) { 1788 // s = s != null ? s : "null"; 1789 // length = length + (s.count - s.offset); 1790 RegionNode *r = new RegionNode(3); 1791 kit.gvn().set_type(r, Type::CONTROL); 1792 Node *phi = new PhiNode(r, type); 1793 kit.gvn().set_type(phi, phi->bottom_type()); 1794 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne); 1795 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN); 1796 Node* notnull = __ IfTrue(iff); 1797 Node* isnull = __ IfFalse(iff); 1798 kit.set_control(notnull); // set control for the cast_not_null 1799 r->init_req(1, notnull); 1800 phi->init_req(1, kit.cast_not_null(arg, false)); 1801 r->init_req(2, isnull); 1802 phi->init_req(2, null_string); 1803 kit.set_control(r); 1804 C->record_for_igvn(r); 1805 C->record_for_igvn(phi); 1806 // replace the argument with the null checked version 1807 arg = phi; 1808 sc->set_argument(argi, arg); 1809 count = kit.load_String_length(kit.control(), arg); 1810 arg_coder = kit.load_String_coder(kit.control(), arg); 1811 } else { 1812 // A corresponding nullcheck will be connected during IGVN MemNode::Ideal_common_DU_postCCP 1813 // kit.control might be a different test, that can be hoisted above the actual nullcheck 1814 // in case, that the control input is not null, Ideal_common_DU_postCCP will not look for a nullcheck. 1815 count = kit.load_String_length(NULL, arg); 1816 arg_coder = kit.load_String_coder(NULL, arg); 1817 } 1818 if (arg->is_Con()) { 1819 // Constant string. Get constant coder and length. 1820 jbyte const_coder = get_constant_coder(kit, arg); 1821 int const_length = get_constant_length(kit, arg); 1822 if (const_coder == java_lang_String::CODER_LATIN1) { 1823 // Can be latin1 encoded 1824 arg_coder = __ intcon(const_coder); 1825 count = __ intcon(const_length); 1826 } else { 1827 // Found UTF16 encoded string. Fix result array encoding to UTF16. 1828 coder_fixed = true; 1829 coder = __ intcon(const_coder); 1830 count = __ intcon(const_length / 2); 1831 } 1832 } 1833 1834 if (!coder_fixed) { 1835 coder = __ OrI(coder, arg_coder); 1836 } 1837 length = __ AddI(length, count); 1838 string_sizes->init_req(argi, NULL); 1839 break; 1840 } 1841 case StringConcat::CharMode: { 1842 // one character only 1843 const TypeInt* t = kit.gvn().type(arg)->is_int(); 1844 if (!coder_fixed && t->is_con()) { 1845 // Constant char 1846 if (t->get_con() <= 255) { 1847 // Can be latin1 encoded 1848 coder = __ OrI(coder, __ intcon(java_lang_String::CODER_LATIN1)); 1849 } else { 1850 // Must be UTF16 encoded. Fix result array encoding to UTF16. 1851 coder_fixed = true; 1852 coder = __ intcon(java_lang_String::CODER_UTF16); 1853 } 1854 } else if (!coder_fixed) { 1855 // Not constant 1856 #undef __ 1857 #define __ ideal. 1858 IdealKit ideal(&kit, true, true); 1859 IdealVariable char_coder(ideal); __ declarations_done(); 1860 // Check if character can be latin1 encoded 1861 __ if_then(arg, BoolTest::le, __ ConI(0xFF)); 1862 __ set(char_coder, __ ConI(java_lang_String::CODER_LATIN1)); 1863 __ else_(); 1864 __ set(char_coder, __ ConI(java_lang_String::CODER_UTF16)); 1865 __ end_if(); 1866 kit.sync_kit(ideal); 1867 coder = __ OrI(coder, __ value(char_coder)); 1868 #undef __ 1869 #define __ kit. 1870 } 1871 length = __ AddI(length, __ intcon(1)); 1872 break; 1873 } 1874 default: 1875 ShouldNotReachHere(); 1876 } 1877 if (argi > 0) { 1878 // Check that the sum hasn't overflowed 1879 IfNode* iff = kit.create_and_map_if(kit.control(), 1880 __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt), 1881 PROB_MIN, COUNT_UNKNOWN); 1882 kit.set_control(__ IfFalse(iff)); 1883 overflow->set_req(argi, __ IfTrue(iff)); 1884 } 1885 } 1886 1887 { 1888 // Hook 1889 PreserveJVMState pjvms(&kit); 1890 kit.set_control(overflow); 1891 C->record_for_igvn(overflow); 1892 kit.uncommon_trap(Deoptimization::Reason_intrinsic, 1893 Deoptimization::Action_make_not_entrant); 1894 } 1895 1896 Node* result; 1897 if (!kit.stopped()) { 1898 assert(CompactStrings || (coder->is_Con() && coder->get_int() == java_lang_String::CODER_UTF16), 1899 "Result string must be UTF16 encoded if CompactStrings is disabled"); 1900 1901 Node* dst_array = NULL; 1902 if (sc->num_arguments() == 1 && 1903 (sc->mode(0) == StringConcat::StringMode || 1904 sc->mode(0) == StringConcat::StringNullCheckMode)) { 1905 // Handle the case when there is only a single String argument. 1906 // In this case, we can just pull the value from the String itself. 1907 dst_array = kit.load_String_value(kit.control(), sc->argument(0)); 1908 } else { 1909 // Allocate destination byte array according to coder 1910 dst_array = allocate_byte_array(kit, NULL, __ LShiftI(length, coder)); 1911 1912 // Now copy the string representations into the final byte[] 1913 Node* start = __ intcon(0); 1914 for (int argi = 0; argi < sc->num_arguments(); argi++) { 1915 Node* arg = sc->argument(argi); 1916 switch (sc->mode(argi)) { 1917 case StringConcat::IntMode: { 1918 start = int_getChars(kit, arg, dst_array, coder, start, string_sizes->in(argi)); 1919 break; 1920 } 1921 case StringConcat::StringNullCheckMode: 1922 case StringConcat::StringMode: { 1923 start = copy_string(kit, arg, dst_array, coder, start); 1924 break; 1925 } 1926 case StringConcat::CharMode: { 1927 start = copy_char(kit, arg, dst_array, coder, start); 1928 break; 1929 } 1930 default: 1931 ShouldNotReachHere(); 1932 } 1933 } 1934 } 1935 1936 // If we're not reusing an existing String allocation then allocate one here. 1937 result = sc->string_alloc(); 1938 if (result == NULL) { 1939 PreserveReexecuteState preexecs(&kit); 1940 // The original jvms is for an allocation of either a String or 1941 // StringBuffer so no stack adjustment is necessary for proper 1942 // reexecution. 1943 kit.jvms()->set_should_reexecute(true); 1944 result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass()))); 1945 } 1946 1947 // Initialize the string 1948 kit.store_String_value(kit.control(), result, dst_array); 1949 kit.store_String_coder(kit.control(), result, coder); 1950 } else { 1951 result = C->top(); 1952 } 1953 // hook up the outgoing control and result 1954 kit.replace_call(sc->end(), result); 1955 1956 // Unhook any hook nodes 1957 string_sizes->disconnect_inputs(NULL, C); 1958 sc->cleanup(); 1959 }