1 /* 2 * Copyright (c) 1997, 2014, 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 "memory/allocation.inline.hpp" 27 #include "opto/block.hpp" 28 #include "opto/callnode.hpp" 29 #include "opto/cfgnode.hpp" 30 #include "opto/idealGraphPrinter.hpp" 31 #include "opto/loopnode.hpp" 32 #include "opto/machnode.hpp" 33 #include "opto/opcodes.hpp" 34 #include "opto/phaseX.hpp" 35 #include "opto/regalloc.hpp" 36 #include "opto/rootnode.hpp" 37 38 //============================================================================= 39 #define NODE_HASH_MINIMUM_SIZE 255 40 //------------------------------NodeHash--------------------------------------- 41 NodeHash::NodeHash(uint est_max_size) : 42 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), 43 _a(Thread::current()->resource_area()), 44 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ), 45 _inserts(0), _insert_limit( insert_limit() ) 46 #ifndef PRODUCT 47 ,_look_probes(0), _lookup_hits(0), _lookup_misses(0), 48 _delete_probes(0), _delete_hits(0), _delete_misses(0), 49 _total_insert_probes(0), _total_inserts(0), 50 _insert_probes(0), _grows(0) 51 #endif 52 { 53 // _sentinel must be in the current node space 54 _sentinel = new ProjNode(NULL, TypeFunc::Control); 55 memset(_table,0,sizeof(Node*)*_max); 56 } 57 58 //------------------------------NodeHash--------------------------------------- 59 NodeHash::NodeHash(Arena *arena, uint est_max_size) : 60 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), 61 _a(arena), 62 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), 63 _inserts(0), _insert_limit( insert_limit() ) 64 #ifndef PRODUCT 65 ,_look_probes(0), _lookup_hits(0), _lookup_misses(0), 66 _delete_probes(0), _delete_hits(0), _delete_misses(0), 67 _total_insert_probes(0), _total_inserts(0), 68 _insert_probes(0), _grows(0) 69 #endif 70 { 71 // _sentinel must be in the current node space 72 _sentinel = new ProjNode(NULL, TypeFunc::Control); 73 memset(_table,0,sizeof(Node*)*_max); 74 } 75 76 //------------------------------NodeHash--------------------------------------- 77 NodeHash::NodeHash(NodeHash *nh) { 78 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= 79 // just copy in all the fields 80 *this = *nh; 81 // nh->_sentinel must be in the current node space 82 } 83 84 void NodeHash::replace_with(NodeHash *nh) { 85 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= 86 // just copy in all the fields 87 *this = *nh; 88 // nh->_sentinel must be in the current node space 89 } 90 91 //------------------------------hash_find-------------------------------------- 92 // Find in hash table 93 Node *NodeHash::hash_find( const Node *n ) { 94 // ((Node*)n)->set_hash( n->hash() ); 95 uint hash = n->hash(); 96 if (hash == Node::NO_HASH) { 97 NOT_PRODUCT( _lookup_misses++ ); 98 return NULL; 99 } 100 uint key = hash & (_max-1); 101 uint stride = key | 0x01; 102 NOT_PRODUCT( _look_probes++ ); 103 Node *k = _table[key]; // Get hashed value 104 if( !k ) { // ?Miss? 105 NOT_PRODUCT( _lookup_misses++ ); 106 return NULL; // Miss! 107 } 108 109 int op = n->Opcode(); 110 uint req = n->req(); 111 while( 1 ) { // While probing hash table 112 if( k->req() == req && // Same count of inputs 113 k->Opcode() == op ) { // Same Opcode 114 for( uint i=0; i<req; i++ ) 115 if( n->in(i)!=k->in(i)) // Different inputs? 116 goto collision; // "goto" is a speed hack... 117 if( n->cmp(*k) ) { // Check for any special bits 118 NOT_PRODUCT( _lookup_hits++ ); 119 return k; // Hit! 120 } 121 } 122 collision: 123 NOT_PRODUCT( _look_probes++ ); 124 key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime 125 k = _table[key]; // Get hashed value 126 if( !k ) { // ?Miss? 127 NOT_PRODUCT( _lookup_misses++ ); 128 return NULL; // Miss! 129 } 130 } 131 ShouldNotReachHere(); 132 return NULL; 133 } 134 135 //------------------------------hash_find_insert------------------------------- 136 // Find in hash table, insert if not already present 137 // Used to preserve unique entries in hash table 138 Node *NodeHash::hash_find_insert( Node *n ) { 139 // n->set_hash( ); 140 uint hash = n->hash(); 141 if (hash == Node::NO_HASH) { 142 NOT_PRODUCT( _lookup_misses++ ); 143 return NULL; 144 } 145 uint key = hash & (_max-1); 146 uint stride = key | 0x01; // stride must be relatively prime to table siz 147 uint first_sentinel = 0; // replace a sentinel if seen. 148 NOT_PRODUCT( _look_probes++ ); 149 Node *k = _table[key]; // Get hashed value 150 if( !k ) { // ?Miss? 151 NOT_PRODUCT( _lookup_misses++ ); 152 _table[key] = n; // Insert into table! 153 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 154 check_grow(); // Grow table if insert hit limit 155 return NULL; // Miss! 156 } 157 else if( k == _sentinel ) { 158 first_sentinel = key; // Can insert here 159 } 160 161 int op = n->Opcode(); 162 uint req = n->req(); 163 while( 1 ) { // While probing hash table 164 if( k->req() == req && // Same count of inputs 165 k->Opcode() == op ) { // Same Opcode 166 for( uint i=0; i<req; i++ ) 167 if( n->in(i)!=k->in(i)) // Different inputs? 168 goto collision; // "goto" is a speed hack... 169 if( n->cmp(*k) ) { // Check for any special bits 170 NOT_PRODUCT( _lookup_hits++ ); 171 return k; // Hit! 172 } 173 } 174 collision: 175 NOT_PRODUCT( _look_probes++ ); 176 key = (key + stride) & (_max-1); // Stride through table w/ relative prime 177 k = _table[key]; // Get hashed value 178 if( !k ) { // ?Miss? 179 NOT_PRODUCT( _lookup_misses++ ); 180 key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel? 181 _table[key] = n; // Insert into table! 182 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 183 check_grow(); // Grow table if insert hit limit 184 return NULL; // Miss! 185 } 186 else if( first_sentinel == 0 && k == _sentinel ) { 187 first_sentinel = key; // Can insert here 188 } 189 190 } 191 ShouldNotReachHere(); 192 return NULL; 193 } 194 195 //------------------------------hash_insert------------------------------------ 196 // Insert into hash table 197 void NodeHash::hash_insert( Node *n ) { 198 // // "conflict" comments -- print nodes that conflict 199 // bool conflict = false; 200 // n->set_hash(); 201 uint hash = n->hash(); 202 if (hash == Node::NO_HASH) { 203 return; 204 } 205 check_grow(); 206 uint key = hash & (_max-1); 207 uint stride = key | 0x01; 208 209 while( 1 ) { // While probing hash table 210 NOT_PRODUCT( _insert_probes++ ); 211 Node *k = _table[key]; // Get hashed value 212 if( !k || (k == _sentinel) ) break; // Found a slot 213 assert( k != n, "already inserted" ); 214 // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; } 215 key = (key + stride) & (_max-1); // Stride through table w/ relative prime 216 } 217 _table[key] = n; // Insert into table! 218 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 219 // if( conflict ) { n->dump(); } 220 } 221 222 //------------------------------hash_delete------------------------------------ 223 // Replace in hash table with sentinel 224 bool NodeHash::hash_delete( const Node *n ) { 225 Node *k; 226 uint hash = n->hash(); 227 if (hash == Node::NO_HASH) { 228 NOT_PRODUCT( _delete_misses++ ); 229 return false; 230 } 231 uint key = hash & (_max-1); 232 uint stride = key | 0x01; 233 debug_only( uint counter = 0; ); 234 for( ; /* (k != NULL) && (k != _sentinel) */; ) { 235 debug_only( counter++ ); 236 NOT_PRODUCT( _delete_probes++ ); 237 k = _table[key]; // Get hashed value 238 if( !k ) { // Miss? 239 NOT_PRODUCT( _delete_misses++ ); 240 #ifdef ASSERT 241 if( VerifyOpto ) { 242 for( uint i=0; i < _max; i++ ) 243 assert( _table[i] != n, "changed edges with rehashing" ); 244 } 245 #endif 246 return false; // Miss! Not in chain 247 } 248 else if( n == k ) { 249 NOT_PRODUCT( _delete_hits++ ); 250 _table[key] = _sentinel; // Hit! Label as deleted entry 251 debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table. 252 return true; 253 } 254 else { 255 // collision: move through table with prime offset 256 key = (key + stride/*7*/) & (_max-1); 257 assert( counter <= _insert_limit, "Cycle in hash-table"); 258 } 259 } 260 ShouldNotReachHere(); 261 return false; 262 } 263 264 //------------------------------round_up--------------------------------------- 265 // Round up to nearest power of 2 266 uint NodeHash::round_up( uint x ) { 267 x += (x>>2); // Add 25% slop 268 if( x <16 ) return 16; // Small stuff 269 uint i=16; 270 while( i < x ) i <<= 1; // Double to fit 271 return i; // Return hash table size 272 } 273 274 //------------------------------grow------------------------------------------- 275 // Grow _table to next power of 2 and insert old entries 276 void NodeHash::grow() { 277 // Record old state 278 uint old_max = _max; 279 Node **old_table = _table; 280 // Construct new table with twice the space 281 #ifndef PRODUCT 282 _grows++; 283 _total_inserts += _inserts; 284 _total_insert_probes += _insert_probes; 285 _insert_probes = 0; 286 #endif 287 _inserts = 0; 288 _max = _max << 1; 289 _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) ); 290 memset(_table,0,sizeof(Node*)*_max); 291 _insert_limit = insert_limit(); 292 // Insert old entries into the new table 293 for( uint i = 0; i < old_max; i++ ) { 294 Node *m = *old_table++; 295 if( !m || m == _sentinel ) continue; 296 debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table. 297 hash_insert(m); 298 } 299 } 300 301 //------------------------------clear------------------------------------------ 302 // Clear all entries in _table to NULL but keep storage 303 void NodeHash::clear() { 304 #ifdef ASSERT 305 // Unlock all nodes upon removal from table. 306 for (uint i = 0; i < _max; i++) { 307 Node* n = _table[i]; 308 if (!n || n == _sentinel) continue; 309 n->exit_hash_lock(); 310 } 311 #endif 312 313 memset( _table, 0, _max * sizeof(Node*) ); 314 } 315 316 //-----------------------remove_useless_nodes---------------------------------- 317 // Remove useless nodes from value table, 318 // implementation does not depend on hash function 319 void NodeHash::remove_useless_nodes(VectorSet &useful) { 320 321 // Dead nodes in the hash table inherited from GVN should not replace 322 // existing nodes, remove dead nodes. 323 uint max = size(); 324 Node *sentinel_node = sentinel(); 325 for( uint i = 0; i < max; ++i ) { 326 Node *n = at(i); 327 if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) { 328 debug_only(n->exit_hash_lock()); // Unlock the node when removed 329 _table[i] = sentinel_node; // Replace with placeholder 330 } 331 } 332 } 333 334 335 void NodeHash::check_no_speculative_types() { 336 #ifdef ASSERT 337 uint max = size(); 338 Node *sentinel_node = sentinel(); 339 for (uint i = 0; i < max; ++i) { 340 Node *n = at(i); 341 if(n != NULL && n != sentinel_node && n->is_Type() && n->outcnt() > 0) { 342 TypeNode* tn = n->as_Type(); 343 const Type* t = tn->type(); 344 const Type* t_no_spec = t->remove_speculative(); 345 assert(t == t_no_spec, "dead node in hash table or missed node during speculative cleanup"); 346 } 347 } 348 #endif 349 } 350 351 #ifndef PRODUCT 352 //------------------------------dump------------------------------------------- 353 // Dump statistics for the hash table 354 void NodeHash::dump() { 355 _total_inserts += _inserts; 356 _total_insert_probes += _insert_probes; 357 if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) { 358 if (WizardMode) { 359 for (uint i=0; i<_max; i++) { 360 if (_table[i]) 361 tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx); 362 } 363 } 364 tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max); 365 tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0); 366 tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses)); 367 tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts); 368 // sentinels increase lookup cost, but not insert cost 369 assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function"); 370 assert( _inserts+(_inserts>>3) < _max, "table too full" ); 371 assert( _inserts*3+100 >= _insert_probes, "bad hash function" ); 372 } 373 } 374 375 Node *NodeHash::find_index(uint idx) { // For debugging 376 // Find an entry by its index value 377 for( uint i = 0; i < _max; i++ ) { 378 Node *m = _table[i]; 379 if( !m || m == _sentinel ) continue; 380 if( m->_idx == (uint)idx ) return m; 381 } 382 return NULL; 383 } 384 #endif 385 386 #ifdef ASSERT 387 NodeHash::~NodeHash() { 388 // Unlock all nodes upon destruction of table. 389 if (_table != (Node**)badAddress) clear(); 390 } 391 392 void NodeHash::operator=(const NodeHash& nh) { 393 // Unlock all nodes upon replacement of table. 394 if (&nh == this) return; 395 if (_table != (Node**)badAddress) clear(); 396 memcpy(this, &nh, sizeof(*this)); 397 // Do not increment hash_lock counts again. 398 // Instead, be sure we never again use the source table. 399 ((NodeHash*)&nh)->_table = (Node**)badAddress; 400 } 401 402 403 #endif 404 405 406 //============================================================================= 407 //------------------------------PhaseRemoveUseless----------------------------- 408 // 1) Use a breadthfirst walk to collect useful nodes reachable from root. 409 PhaseRemoveUseless::PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ) : Phase(Remove_Useless), 410 _useful(Thread::current()->resource_area()) { 411 412 // Implementation requires 'UseLoopSafepoints == true' and an edge from root 413 // to each SafePointNode at a backward branch. Inserted in add_safepoint(). 414 if( !UseLoopSafepoints || !OptoRemoveUseless ) return; 415 416 // Identify nodes that are reachable from below, useful. 417 C->identify_useful_nodes(_useful); 418 // Update dead node list 419 C->update_dead_node_list(_useful); 420 421 // Remove all useless nodes from PhaseValues' recorded types 422 // Must be done before disconnecting nodes to preserve hash-table-invariant 423 gvn->remove_useless_nodes(_useful.member_set()); 424 425 // Remove all useless nodes from future worklist 426 worklist->remove_useless_nodes(_useful.member_set()); 427 428 // Disconnect 'useless' nodes that are adjacent to useful nodes 429 C->remove_useless_nodes(_useful); 430 431 // Remove edges from "root" to each SafePoint at a backward branch. 432 // They were inserted during parsing (see add_safepoint()) to make infinite 433 // loops without calls or exceptions visible to root, i.e., useful. 434 Node *root = C->root(); 435 if( root != NULL ) { 436 for( uint i = root->req(); i < root->len(); ++i ) { 437 Node *n = root->in(i); 438 if( n != NULL && n->is_SafePoint() ) { 439 root->rm_prec(i); 440 --i; 441 } 442 } 443 } 444 } 445 446 447 //============================================================================= 448 //------------------------------PhaseTransform--------------------------------- 449 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum), 450 _arena(Thread::current()->resource_area()), 451 _nodes(_arena), 452 _types(_arena) 453 { 454 init_con_caches(); 455 #ifndef PRODUCT 456 clear_progress(); 457 clear_transforms(); 458 set_allow_progress(true); 459 #endif 460 // Force allocation for currently existing nodes 461 _types.map(C->unique(), NULL); 462 } 463 464 //------------------------------PhaseTransform--------------------------------- 465 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum), 466 _arena(arena), 467 _nodes(arena), 468 _types(arena) 469 { 470 init_con_caches(); 471 #ifndef PRODUCT 472 clear_progress(); 473 clear_transforms(); 474 set_allow_progress(true); 475 #endif 476 // Force allocation for currently existing nodes 477 _types.map(C->unique(), NULL); 478 } 479 480 //------------------------------PhaseTransform--------------------------------- 481 // Initialize with previously generated type information 482 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum), 483 _arena(pt->_arena), 484 _nodes(pt->_nodes), 485 _types(pt->_types) 486 { 487 init_con_caches(); 488 #ifndef PRODUCT 489 clear_progress(); 490 clear_transforms(); 491 set_allow_progress(true); 492 #endif 493 } 494 495 void PhaseTransform::init_con_caches() { 496 memset(_icons,0,sizeof(_icons)); 497 memset(_lcons,0,sizeof(_lcons)); 498 memset(_zcons,0,sizeof(_zcons)); 499 } 500 501 502 //--------------------------------find_int_type-------------------------------- 503 const TypeInt* PhaseTransform::find_int_type(Node* n) { 504 if (n == NULL) return NULL; 505 // Call type_or_null(n) to determine node's type since we might be in 506 // parse phase and call n->Value() may return wrong type. 507 // (For example, a phi node at the beginning of loop parsing is not ready.) 508 const Type* t = type_or_null(n); 509 if (t == NULL) return NULL; 510 return t->isa_int(); 511 } 512 513 514 //-------------------------------find_long_type-------------------------------- 515 const TypeLong* PhaseTransform::find_long_type(Node* n) { 516 if (n == NULL) return NULL; 517 // (See comment above on type_or_null.) 518 const Type* t = type_or_null(n); 519 if (t == NULL) return NULL; 520 return t->isa_long(); 521 } 522 523 524 #ifndef PRODUCT 525 void PhaseTransform::dump_old2new_map() const { 526 _nodes.dump(); 527 } 528 529 void PhaseTransform::dump_new( uint nidx ) const { 530 for( uint i=0; i<_nodes.Size(); i++ ) 531 if( _nodes[i] && _nodes[i]->_idx == nidx ) { 532 _nodes[i]->dump(); 533 tty->cr(); 534 tty->print_cr("Old index= %d",i); 535 return; 536 } 537 tty->print_cr("Node %d not found in the new indices", nidx); 538 } 539 540 //------------------------------dump_types------------------------------------- 541 void PhaseTransform::dump_types( ) const { 542 _types.dump(); 543 } 544 545 //------------------------------dump_nodes_and_types--------------------------- 546 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) { 547 VectorSet visited(Thread::current()->resource_area()); 548 dump_nodes_and_types_recur( root, depth, only_ctrl, visited ); 549 } 550 551 //------------------------------dump_nodes_and_types_recur--------------------- 552 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) { 553 if( !n ) return; 554 if( depth == 0 ) return; 555 if( visited.test_set(n->_idx) ) return; 556 for( uint i=0; i<n->len(); i++ ) { 557 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue; 558 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited ); 559 } 560 n->dump(); 561 if (type_or_null(n) != NULL) { 562 tty->print(" "); type(n)->dump(); tty->cr(); 563 } 564 } 565 566 #endif 567 568 569 //============================================================================= 570 //------------------------------PhaseValues------------------------------------ 571 // Set minimum table size to "255" 572 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) { 573 NOT_PRODUCT( clear_new_values(); ) 574 } 575 576 //------------------------------PhaseValues------------------------------------ 577 // Set minimum table size to "255" 578 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ), 579 _table(&ptv->_table) { 580 NOT_PRODUCT( clear_new_values(); ) 581 } 582 583 //------------------------------PhaseValues------------------------------------ 584 // Used by +VerifyOpto. Clear out hash table but copy _types array. 585 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ), 586 _table(ptv->arena(),ptv->_table.size()) { 587 NOT_PRODUCT( clear_new_values(); ) 588 } 589 590 //------------------------------~PhaseValues----------------------------------- 591 #ifndef PRODUCT 592 PhaseValues::~PhaseValues() { 593 _table.dump(); 594 595 // Statistics for value progress and efficiency 596 if( PrintCompilation && Verbose && WizardMode ) { 597 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)", 598 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values()); 599 if( made_transforms() != 0 ) { 600 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() ); 601 } else { 602 tty->cr(); 603 } 604 } 605 } 606 #endif 607 608 //------------------------------makecon---------------------------------------- 609 ConNode* PhaseTransform::makecon(const Type *t) { 610 assert(t->singleton(), "must be a constant"); 611 assert(!t->empty() || t == Type::TOP, "must not be vacuous range"); 612 switch (t->base()) { // fast paths 613 case Type::Half: 614 case Type::Top: return (ConNode*) C->top(); 615 case Type::Int: return intcon( t->is_int()->get_con() ); 616 case Type::Long: return longcon( t->is_long()->get_con() ); 617 } 618 if (t->is_zero_type()) 619 return zerocon(t->basic_type()); 620 return uncached_makecon(t); 621 } 622 623 //--------------------------uncached_makecon----------------------------------- 624 // Make an idealized constant - one of ConINode, ConPNode, etc. 625 ConNode* PhaseValues::uncached_makecon(const Type *t) { 626 assert(t->singleton(), "must be a constant"); 627 ConNode* x = ConNode::make(t); 628 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering 629 if (k == NULL) { 630 set_type(x, t); // Missed, provide type mapping 631 GrowableArray<Node_Notes*>* nna = C->node_note_array(); 632 if (nna != NULL) { 633 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true); 634 loc->clear(); // do not put debug info on constants 635 } 636 } else { 637 x->destruct(); // Hit, destroy duplicate constant 638 x = k; // use existing constant 639 } 640 return x; 641 } 642 643 //------------------------------intcon----------------------------------------- 644 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))" 645 ConINode* PhaseTransform::intcon(int i) { 646 // Small integer? Check cache! Check that cached node is not dead 647 if (i >= _icon_min && i <= _icon_max) { 648 ConINode* icon = _icons[i-_icon_min]; 649 if (icon != NULL && icon->in(TypeFunc::Control) != NULL) 650 return icon; 651 } 652 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i)); 653 assert(icon->is_Con(), ""); 654 if (i >= _icon_min && i <= _icon_max) 655 _icons[i-_icon_min] = icon; // Cache small integers 656 return icon; 657 } 658 659 //------------------------------longcon---------------------------------------- 660 // Fast long constant. 661 ConLNode* PhaseTransform::longcon(jlong l) { 662 // Small integer? Check cache! Check that cached node is not dead 663 if (l >= _lcon_min && l <= _lcon_max) { 664 ConLNode* lcon = _lcons[l-_lcon_min]; 665 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL) 666 return lcon; 667 } 668 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l)); 669 assert(lcon->is_Con(), ""); 670 if (l >= _lcon_min && l <= _lcon_max) 671 _lcons[l-_lcon_min] = lcon; // Cache small integers 672 return lcon; 673 } 674 675 //------------------------------zerocon----------------------------------------- 676 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))" 677 ConNode* PhaseTransform::zerocon(BasicType bt) { 678 assert((uint)bt <= _zcon_max, "domain check"); 679 ConNode* zcon = _zcons[bt]; 680 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL) 681 return zcon; 682 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt)); 683 _zcons[bt] = zcon; 684 return zcon; 685 } 686 687 688 689 //============================================================================= 690 //------------------------------transform-------------------------------------- 691 // Return a node which computes the same function as this node, but in a 692 // faster or cheaper fashion. 693 Node *PhaseGVN::transform( Node *n ) { 694 return transform_no_reclaim(n); 695 } 696 697 //------------------------------transform-------------------------------------- 698 // Return a node which computes the same function as this node, but 699 // in a faster or cheaper fashion. 700 Node *PhaseGVN::transform_no_reclaim( Node *n ) { 701 NOT_PRODUCT( set_transforms(); ) 702 703 // Apply the Ideal call in a loop until it no longer applies 704 Node *k = n; 705 NOT_PRODUCT( uint loop_count = 0; ) 706 while( 1 ) { 707 Node *i = k->Ideal(this, /*can_reshape=*/false); 708 if( !i ) break; 709 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" ); 710 k = i; 711 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform"); 712 } 713 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } ) 714 715 716 // If brand new node, make space in type array. 717 ensure_type_or_null(k); 718 719 // Since I just called 'Value' to compute the set of run-time values 720 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 721 // cache Value. Later requests for the local phase->type of this Node can 722 // use the cached Value instead of suffering with 'bottom_type'. 723 const Type *t = k->Value(this); // Get runtime Value set 724 assert(t != NULL, "value sanity"); 725 if (type_or_null(k) != t) { 726 #ifndef PRODUCT 727 // Do not count initial visit to node as a transformation 728 if (type_or_null(k) == NULL) { 729 inc_new_values(); 730 set_progress(); 731 } 732 #endif 733 set_type(k, t); 734 // If k is a TypeNode, capture any more-precise type permanently into Node 735 k->raise_bottom_type(t); 736 } 737 738 if( t->singleton() && !k->is_Con() ) { 739 NOT_PRODUCT( set_progress(); ) 740 return makecon(t); // Turn into a constant 741 } 742 743 // Now check for Identities 744 Node *i = k->Identity(this); // Look for a nearby replacement 745 if( i != k ) { // Found? Return replacement! 746 NOT_PRODUCT( set_progress(); ) 747 return i; 748 } 749 750 // Global Value Numbering 751 i = hash_find_insert(k); // Insert if new 752 if( i && (i != k) ) { 753 // Return the pre-existing node 754 NOT_PRODUCT( set_progress(); ) 755 return i; 756 } 757 758 // Return Idealized original 759 return k; 760 } 761 762 #ifdef ASSERT 763 //------------------------------dead_loop_check-------------------------------- 764 // Check for a simple dead loop when a data node references itself directly 765 // or through an other data node excluding cons and phis. 766 void PhaseGVN::dead_loop_check( Node *n ) { 767 // Phi may reference itself in a loop 768 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) { 769 // Do 2 levels check and only data inputs. 770 bool no_dead_loop = true; 771 uint cnt = n->req(); 772 for (uint i = 1; i < cnt && no_dead_loop; i++) { 773 Node *in = n->in(i); 774 if (in == n) { 775 no_dead_loop = false; 776 } else if (in != NULL && !in->is_dead_loop_safe()) { 777 uint icnt = in->req(); 778 for (uint j = 1; j < icnt && no_dead_loop; j++) { 779 if (in->in(j) == n || in->in(j) == in) 780 no_dead_loop = false; 781 } 782 } 783 } 784 if (!no_dead_loop) n->dump(3); 785 assert(no_dead_loop, "dead loop detected"); 786 } 787 } 788 #endif 789 790 //============================================================================= 791 //------------------------------PhaseIterGVN----------------------------------- 792 // Initialize hash table to fresh and clean for +VerifyOpto 793 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ), 794 _stack(C->unique() >> 1), 795 _delay_transform(false) { 796 } 797 798 //------------------------------PhaseIterGVN----------------------------------- 799 // Initialize with previous PhaseIterGVN info; used by PhaseCCP 800 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn), 801 _worklist( igvn->_worklist ), 802 _stack( igvn->_stack ), 803 _delay_transform(igvn->_delay_transform) 804 { 805 } 806 807 //------------------------------PhaseIterGVN----------------------------------- 808 // Initialize with previous PhaseGVN info from Parser 809 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn), 810 _worklist(*C->for_igvn()), 811 _stack(C->unique() >> 1), 812 _delay_transform(false) 813 { 814 uint max; 815 816 // Dead nodes in the hash table inherited from GVN were not treated as 817 // roots during def-use info creation; hence they represent an invisible 818 // use. Clear them out. 819 max = _table.size(); 820 for( uint i = 0; i < max; ++i ) { 821 Node *n = _table.at(i); 822 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) { 823 if( n->is_top() ) continue; 824 assert( false, "Parse::remove_useless_nodes missed this node"); 825 hash_delete(n); 826 } 827 } 828 829 // Any Phis or Regions on the worklist probably had uses that could not 830 // make more progress because the uses were made while the Phis and Regions 831 // were in half-built states. Put all uses of Phis and Regions on worklist. 832 max = _worklist.size(); 833 for( uint j = 0; j < max; j++ ) { 834 Node *n = _worklist.at(j); 835 uint uop = n->Opcode(); 836 if( uop == Op_Phi || uop == Op_Region || 837 n->is_Type() || 838 n->is_Mem() ) 839 add_users_to_worklist(n); 840 } 841 } 842 843 /** 844 * Initialize worklist for each node. 845 */ 846 void PhaseIterGVN::init_worklist(Node* first) { 847 Unique_Node_List to_process; 848 to_process.push(first); 849 850 while (to_process.size() > 0) { 851 Node* n = to_process.pop(); 852 if (!_worklist.member(n)) { 853 _worklist.push(n); 854 855 uint cnt = n->req(); 856 for(uint i = 0; i < cnt; i++) { 857 Node* m = n->in(i); 858 if (m != NULL) { 859 to_process.push(m); 860 } 861 } 862 } 863 } 864 } 865 866 #ifndef PRODUCT 867 void PhaseIterGVN::verify_step(Node* n) { 868 if (VerifyIterativeGVN) { 869 _verify_window[_verify_counter % _verify_window_size] = n; 870 ++_verify_counter; 871 ResourceMark rm; 872 ResourceArea* area = Thread::current()->resource_area(); 873 VectorSet old_space(area), new_space(area); 874 if (C->unique() < 1000 || 875 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) { 876 ++_verify_full_passes; 877 Node::verify_recur(C->root(), -1, old_space, new_space); 878 } 879 const int verify_depth = 4; 880 for ( int i = 0; i < _verify_window_size; i++ ) { 881 Node* n = _verify_window[i]; 882 if ( n == NULL ) continue; 883 if( n->in(0) == NodeSentinel ) { // xform_idom 884 _verify_window[i] = n->in(1); 885 --i; continue; 886 } 887 // Typical fanout is 1-2, so this call visits about 6 nodes. 888 Node::verify_recur(n, verify_depth, old_space, new_space); 889 } 890 } 891 } 892 893 void PhaseIterGVN::trace_PhaseIterGVN(Node* n, Node* nn, const Type* oldtype) { 894 if (TraceIterativeGVN) { 895 uint wlsize = _worklist.size(); 896 const Type* newtype = type_or_null(n); 897 if (nn != n) { 898 // print old node 899 tty->print("< "); 900 if (oldtype != newtype && oldtype != NULL) { 901 oldtype->dump(); 902 } 903 do { tty->print("\t"); } while (tty->position() < 16); 904 tty->print("<"); 905 n->dump(); 906 } 907 if (oldtype != newtype || nn != n) { 908 // print new node and/or new type 909 if (oldtype == NULL) { 910 tty->print("* "); 911 } else if (nn != n) { 912 tty->print("> "); 913 } else { 914 tty->print("= "); 915 } 916 if (newtype == NULL) { 917 tty->print("null"); 918 } else { 919 newtype->dump(); 920 } 921 do { tty->print("\t"); } while (tty->position() < 16); 922 nn->dump(); 923 } 924 if (Verbose && wlsize < _worklist.size()) { 925 tty->print(" Push {"); 926 while (wlsize != _worklist.size()) { 927 Node* pushed = _worklist.at(wlsize++); 928 tty->print(" %d", pushed->_idx); 929 } 930 tty->print_cr(" }"); 931 } 932 if (nn != n) { 933 // ignore n, it might be subsumed 934 verify_step((Node*) NULL); 935 } 936 } 937 } 938 939 void PhaseIterGVN::init_verifyPhaseIterGVN() { 940 _verify_counter = 0; 941 _verify_full_passes = 0; 942 for (int i = 0; i < _verify_window_size; i++) { 943 _verify_window[i] = NULL; 944 } 945 #ifdef ASSERT 946 // Verify that all modified nodes are on _worklist 947 Unique_Node_List* modified_list = C->modified_nodes(); 948 while (modified_list != NULL && modified_list->size()) { 949 Node* n = modified_list->pop(); 950 if (n->outcnt() != 0 && !n->is_Con() && !_worklist.member(n)) { 951 n->dump(); 952 assert(false, "modified node is not on IGVN._worklist"); 953 } 954 } 955 #endif 956 } 957 958 void PhaseIterGVN::verify_PhaseIterGVN() { 959 #ifdef ASSERT 960 // Verify nodes with changed inputs. 961 Unique_Node_List* modified_list = C->modified_nodes(); 962 while (modified_list != NULL && modified_list->size()) { 963 Node* n = modified_list->pop(); 964 if (n->outcnt() != 0 && !n->is_Con()) { // skip dead and Con nodes 965 n->dump(); 966 assert(false, "modified node was not processed by IGVN.transform_old()"); 967 } 968 } 969 #endif 970 971 C->verify_graph_edges(); 972 if( VerifyOpto && allow_progress() ) { 973 // Must turn off allow_progress to enable assert and break recursion 974 C->root()->verify(); 975 { // Check if any progress was missed using IterGVN 976 // Def-Use info enables transformations not attempted in wash-pass 977 // e.g. Region/Phi cleanup, ... 978 // Null-check elision -- may not have reached fixpoint 979 // do not propagate to dominated nodes 980 ResourceMark rm; 981 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean! 982 // Fill worklist completely 983 igvn2.init_worklist(C->root()); 984 985 igvn2.set_allow_progress(false); 986 igvn2.optimize(); 987 igvn2.set_allow_progress(true); 988 } 989 } 990 if (VerifyIterativeGVN && PrintOpto) { 991 if (_verify_counter == _verify_full_passes) { 992 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes", 993 (int) _verify_full_passes); 994 } else { 995 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes", 996 (int) _verify_counter, (int) _verify_full_passes); 997 } 998 } 999 1000 #ifdef ASSERT 1001 while (modified_list->size()) { 1002 Node* n = modified_list->pop(); 1003 n->dump(); 1004 assert(false, "VerifyIterativeGVN: new modified node was added"); 1005 } 1006 #endif 1007 } 1008 #endif /* PRODUCT */ 1009 1010 #ifdef ASSERT 1011 /** 1012 * Dumps information that can help to debug the problem. A debug 1013 * build fails with an assert. 1014 */ 1015 void PhaseIterGVN::dump_infinite_loop_info(Node* n) { 1016 n->dump(4); 1017 _worklist.dump(); 1018 assert(false, "infinite loop in PhaseIterGVN::optimize"); 1019 } 1020 1021 /** 1022 * Prints out information about IGVN if the 'verbose' option is used. 1023 */ 1024 void PhaseIterGVN::trace_PhaseIterGVN_verbose(Node* n, int num_processed) { 1025 if (TraceIterativeGVN && Verbose) { 1026 tty->print(" Pop "); 1027 n->dump(); 1028 if ((num_processed % 100) == 0) { 1029 _worklist.print_set(); 1030 } 1031 } 1032 } 1033 #endif /* ASSERT */ 1034 1035 void PhaseIterGVN::optimize() { 1036 DEBUG_ONLY(uint num_processed = 0;) 1037 NOT_PRODUCT(init_verifyPhaseIterGVN();) 1038 1039 uint loop_count = 0; 1040 // Pull from worklist and transform the node. If the node has changed, 1041 // update edge info and put uses on worklist. 1042 while(_worklist.size()) { 1043 if (C->check_node_count(NodeLimitFudgeFactor * 2, "Out of nodes")) { 1044 return; 1045 } 1046 Node* n = _worklist.pop(); 1047 if (++loop_count >= K * C->live_nodes()) { 1048 DEBUG_ONLY(dump_infinite_loop_info(n);) 1049 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize"); 1050 return; 1051 } 1052 DEBUG_ONLY(trace_PhaseIterGVN_verbose(n, num_processed++);) 1053 if (n->outcnt() != 0) { 1054 NOT_PRODUCT(const Type* oldtype = type_or_null(n)); 1055 // Do the transformation 1056 Node* nn = transform_old(n); 1057 NOT_PRODUCT(trace_PhaseIterGVN(n, nn, oldtype);) 1058 } else if (!n->is_top()) { 1059 remove_dead_node(n); 1060 } 1061 } 1062 NOT_PRODUCT(verify_PhaseIterGVN();) 1063 } 1064 1065 1066 /** 1067 * Register a new node with the optimizer. Update the types array, the def-use 1068 * info. Put on worklist. 1069 */ 1070 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) { 1071 set_type_bottom(n); 1072 _worklist.push(n); 1073 if (orig != NULL) C->copy_node_notes_to(n, orig); 1074 return n; 1075 } 1076 1077 //------------------------------transform-------------------------------------- 1078 // Non-recursive: idealize Node 'n' with respect to its inputs and its value 1079 Node *PhaseIterGVN::transform( Node *n ) { 1080 if (_delay_transform) { 1081 // Register the node but don't optimize for now 1082 register_new_node_with_optimizer(n); 1083 return n; 1084 } 1085 1086 // If brand new node, make space in type array, and give it a type. 1087 ensure_type_or_null(n); 1088 if (type_or_null(n) == NULL) { 1089 set_type_bottom(n); 1090 } 1091 1092 return transform_old(n); 1093 } 1094 1095 Node *PhaseIterGVN::transform_old(Node* n) { 1096 DEBUG_ONLY(uint loop_count = 0;); 1097 NOT_PRODUCT(set_transforms()); 1098 1099 // Remove 'n' from hash table in case it gets modified 1100 _table.hash_delete(n); 1101 if (VerifyIterativeGVN) { 1102 assert(!_table.find_index(n->_idx), "found duplicate entry in table"); 1103 } 1104 1105 // Apply the Ideal call in a loop until it no longer applies 1106 Node* k = n; 1107 DEBUG_ONLY(dead_loop_check(k);) 1108 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);) 1109 C->remove_modified_node(k); 1110 Node* i = k->Ideal(this, /*can_reshape=*/true); 1111 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1112 #ifndef PRODUCT 1113 verify_step(k); 1114 if (i && VerifyOpto ) { 1115 if (!allow_progress()) { 1116 if (i->is_Add() && (i->outcnt() == 1)) { 1117 // Switched input to left side because this is the only use 1118 } else if (i->is_If() && (i->in(0) == NULL)) { 1119 // This IF is dead because it is dominated by an equivalent IF When 1120 // dominating if changed, info is not propagated sparsely to 'this' 1121 // Propagating this info further will spuriously identify other 1122 // progress. 1123 return i; 1124 } else 1125 set_progress(); 1126 } else { 1127 set_progress(); 1128 } 1129 } 1130 #endif 1131 1132 while (i != NULL) { 1133 #ifdef ASSERT 1134 if (loop_count >= K) { 1135 dump_infinite_loop_info(i); 1136 } 1137 loop_count++; 1138 #endif 1139 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes"); 1140 // Made a change; put users of original Node on worklist 1141 add_users_to_worklist(k); 1142 // Replacing root of transform tree? 1143 if (k != i) { 1144 // Make users of old Node now use new. 1145 subsume_node(k, i); 1146 k = i; 1147 } 1148 DEBUG_ONLY(dead_loop_check(k);) 1149 // Try idealizing again 1150 DEBUG_ONLY(is_new = (k->outcnt() == 0);) 1151 C->remove_modified_node(k); 1152 i = k->Ideal(this, /*can_reshape=*/true); 1153 assert(i != k || is_new || (i->outcnt() > 0), "don't return dead nodes"); 1154 #ifndef PRODUCT 1155 verify_step(k); 1156 if (i && VerifyOpto) { 1157 set_progress(); 1158 } 1159 #endif 1160 } 1161 1162 // If brand new node, make space in type array. 1163 ensure_type_or_null(k); 1164 1165 // See what kind of values 'k' takes on at runtime 1166 const Type* t = k->Value(this); 1167 assert(t != NULL, "value sanity"); 1168 1169 // Since I just called 'Value' to compute the set of run-time values 1170 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 1171 // cache Value. Later requests for the local phase->type of this Node can 1172 // use the cached Value instead of suffering with 'bottom_type'. 1173 if (type_or_null(k) != t) { 1174 #ifndef PRODUCT 1175 inc_new_values(); 1176 set_progress(); 1177 #endif 1178 set_type(k, t); 1179 // If k is a TypeNode, capture any more-precise type permanently into Node 1180 k->raise_bottom_type(t); 1181 // Move users of node to worklist 1182 add_users_to_worklist(k); 1183 } 1184 // If 'k' computes a constant, replace it with a constant 1185 if (t->singleton() && !k->is_Con()) { 1186 NOT_PRODUCT(set_progress();) 1187 Node* con = makecon(t); // Make a constant 1188 add_users_to_worklist(k); 1189 subsume_node(k, con); // Everybody using k now uses con 1190 return con; 1191 } 1192 1193 // Now check for Identities 1194 i = k->Identity(this); // Look for a nearby replacement 1195 if (i != k) { // Found? Return replacement! 1196 NOT_PRODUCT(set_progress();) 1197 add_users_to_worklist(k); 1198 subsume_node(k, i); // Everybody using k now uses i 1199 return i; 1200 } 1201 1202 // Global Value Numbering 1203 i = hash_find_insert(k); // Check for pre-existing node 1204 if (i && (i != k)) { 1205 // Return the pre-existing node if it isn't dead 1206 NOT_PRODUCT(set_progress();) 1207 add_users_to_worklist(k); 1208 subsume_node(k, i); // Everybody using k now uses i 1209 return i; 1210 } 1211 1212 // Return Idealized original 1213 return k; 1214 } 1215 1216 //---------------------------------saturate------------------------------------ 1217 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type, 1218 const Type* limit_type) const { 1219 return new_type->narrow(old_type); 1220 } 1221 1222 //------------------------------remove_globally_dead_node---------------------- 1223 // Kill a globally dead Node. All uses are also globally dead and are 1224 // aggressively trimmed. 1225 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) { 1226 enum DeleteProgress { 1227 PROCESS_INPUTS, 1228 PROCESS_OUTPUTS 1229 }; 1230 assert(_stack.is_empty(), "not empty"); 1231 _stack.push(dead, PROCESS_INPUTS); 1232 1233 while (_stack.is_nonempty()) { 1234 dead = _stack.node(); 1235 uint progress_state = _stack.index(); 1236 assert(dead != C->root(), "killing root, eh?"); 1237 assert(!dead->is_top(), "add check for top when pushing"); 1238 NOT_PRODUCT( set_progress(); ) 1239 if (progress_state == PROCESS_INPUTS) { 1240 // After following inputs, continue to outputs 1241 _stack.set_index(PROCESS_OUTPUTS); 1242 if (!dead->is_Con()) { // Don't kill cons but uses 1243 bool recurse = false; 1244 // Remove from hash table 1245 _table.hash_delete( dead ); 1246 // Smash all inputs to 'dead', isolating him completely 1247 for (uint i = 0; i < dead->req(); i++) { 1248 Node *in = dead->in(i); 1249 if (in != NULL && in != C->top()) { // Points to something? 1250 int nrep = dead->replace_edge(in, NULL); // Kill edges 1251 assert((nrep > 0), "sanity"); 1252 if (in->outcnt() == 0) { // Made input go dead? 1253 _stack.push(in, PROCESS_INPUTS); // Recursively remove 1254 recurse = true; 1255 } else if (in->outcnt() == 1 && 1256 in->has_special_unique_user()) { 1257 _worklist.push(in->unique_out()); 1258 } else if (in->outcnt() <= 2 && dead->is_Phi()) { 1259 if (in->Opcode() == Op_Region) { 1260 _worklist.push(in); 1261 } else if (in->is_Store()) { 1262 DUIterator_Fast imax, i = in->fast_outs(imax); 1263 _worklist.push(in->fast_out(i)); 1264 i++; 1265 if (in->outcnt() == 2) { 1266 _worklist.push(in->fast_out(i)); 1267 i++; 1268 } 1269 assert(!(i < imax), "sanity"); 1270 } 1271 } 1272 if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory && 1273 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) { 1274 // A Load that directly follows an InitializeNode is 1275 // going away. The Stores that follow are candidates 1276 // again to be captured by the InitializeNode. 1277 for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) { 1278 Node *n = in->fast_out(j); 1279 if (n->is_Store()) { 1280 _worklist.push(n); 1281 } 1282 } 1283 } 1284 } // if (in != NULL && in != C->top()) 1285 } // for (uint i = 0; i < dead->req(); i++) 1286 if (recurse) { 1287 continue; 1288 } 1289 } // if (!dead->is_Con()) 1290 } // if (progress_state == PROCESS_INPUTS) 1291 1292 // Aggressively kill globally dead uses 1293 // (Rather than pushing all the outs at once, we push one at a time, 1294 // plus the parent to resume later, because of the indefinite number 1295 // of edge deletions per loop trip.) 1296 if (dead->outcnt() > 0) { 1297 // Recursively remove output edges 1298 _stack.push(dead->raw_out(0), PROCESS_INPUTS); 1299 } else { 1300 // Finished disconnecting all input and output edges. 1301 _stack.pop(); 1302 // Remove dead node from iterative worklist 1303 _worklist.remove(dead); 1304 C->remove_modified_node(dead); 1305 // Constant node that has no out-edges and has only one in-edge from 1306 // root is usually dead. However, sometimes reshaping walk makes 1307 // it reachable by adding use edges. So, we will NOT count Con nodes 1308 // as dead to be conservative about the dead node count at any 1309 // given time. 1310 if (!dead->is_Con()) { 1311 C->record_dead_node(dead->_idx); 1312 } 1313 if (dead->is_macro()) { 1314 C->remove_macro_node(dead); 1315 } 1316 if (dead->is_expensive()) { 1317 C->remove_expensive_node(dead); 1318 } 1319 } 1320 } // while (_stack.is_nonempty()) 1321 } 1322 1323 //------------------------------subsume_node----------------------------------- 1324 // Remove users from node 'old' and add them to node 'nn'. 1325 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) { 1326 assert( old != hash_find(old), "should already been removed" ); 1327 assert( old != C->top(), "cannot subsume top node"); 1328 // Copy debug or profile information to the new version: 1329 C->copy_node_notes_to(nn, old); 1330 // Move users of node 'old' to node 'nn' 1331 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) { 1332 Node* use = old->last_out(i); // for each use... 1333 // use might need re-hashing (but it won't if it's a new node) 1334 rehash_node_delayed(use); 1335 // Update use-def info as well 1336 // We remove all occurrences of old within use->in, 1337 // so as to avoid rehashing any node more than once. 1338 // The hash table probe swamps any outer loop overhead. 1339 uint num_edges = 0; 1340 for (uint jmax = use->len(), j = 0; j < jmax; j++) { 1341 if (use->in(j) == old) { 1342 use->set_req(j, nn); 1343 ++num_edges; 1344 } 1345 } 1346 i -= num_edges; // we deleted 1 or more copies of this edge 1347 } 1348 1349 // Smash all inputs to 'old', isolating him completely 1350 Node *temp = new Node(1); 1351 temp->init_req(0,nn); // Add a use to nn to prevent him from dying 1352 remove_dead_node( old ); 1353 temp->del_req(0); // Yank bogus edge 1354 #ifndef PRODUCT 1355 if( VerifyIterativeGVN ) { 1356 for ( int i = 0; i < _verify_window_size; i++ ) { 1357 if ( _verify_window[i] == old ) 1358 _verify_window[i] = nn; 1359 } 1360 } 1361 #endif 1362 _worklist.remove(temp); // this can be necessary 1363 temp->destruct(); // reuse the _idx of this little guy 1364 } 1365 1366 //------------------------------add_users_to_worklist-------------------------- 1367 void PhaseIterGVN::add_users_to_worklist0( Node *n ) { 1368 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1369 _worklist.push(n->fast_out(i)); // Push on worklist 1370 } 1371 } 1372 1373 void PhaseIterGVN::add_users_to_worklist( Node *n ) { 1374 add_users_to_worklist0(n); 1375 1376 // Move users of node to worklist 1377 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1378 Node* use = n->fast_out(i); // Get use 1379 1380 if( use->is_Multi() || // Multi-definer? Push projs on worklist 1381 use->is_Store() ) // Enable store/load same address 1382 add_users_to_worklist0(use); 1383 1384 // If we changed the receiver type to a call, we need to revisit 1385 // the Catch following the call. It's looking for a non-NULL 1386 // receiver to know when to enable the regular fall-through path 1387 // in addition to the NullPtrException path. 1388 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) { 1389 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control); 1390 if (p != NULL) { 1391 add_users_to_worklist0(p); 1392 } 1393 } 1394 1395 if( use->is_Cmp() ) { // Enable CMP/BOOL optimization 1396 add_users_to_worklist(use); // Put Bool on worklist 1397 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the 1398 // phi merging either 0 or 1 onto the worklist 1399 if (use->outcnt() > 0) { 1400 Node* bol = use->raw_out(0); 1401 if (bol->outcnt() > 0) { 1402 Node* iff = bol->raw_out(0); 1403 if (iff->outcnt() == 2) { 1404 Node* ifproj0 = iff->raw_out(0); 1405 Node* ifproj1 = iff->raw_out(1); 1406 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) { 1407 Node* region0 = ifproj0->raw_out(0); 1408 Node* region1 = ifproj1->raw_out(0); 1409 if( region0 == region1 ) 1410 add_users_to_worklist0(region0); 1411 } 1412 } 1413 } 1414 } 1415 } 1416 1417 uint use_op = use->Opcode(); 1418 // If changed Cast input, check Phi users for simple cycles 1419 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) { 1420 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1421 Node* u = use->fast_out(i2); 1422 if (u->is_Phi()) 1423 _worklist.push(u); 1424 } 1425 } 1426 // If changed LShift inputs, check RShift users for useless sign-ext 1427 if( use_op == Op_LShiftI ) { 1428 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1429 Node* u = use->fast_out(i2); 1430 if (u->Opcode() == Op_RShiftI) 1431 _worklist.push(u); 1432 } 1433 } 1434 // If changed AddI/SubI inputs, check CmpU for range check optimization. 1435 if (use_op == Op_AddI || use_op == Op_SubI) { 1436 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1437 Node* u = use->fast_out(i2); 1438 if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) { 1439 _worklist.push(u); 1440 } 1441 } 1442 } 1443 // If changed AddP inputs, check Stores for loop invariant 1444 if( use_op == Op_AddP ) { 1445 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1446 Node* u = use->fast_out(i2); 1447 if (u->is_Mem()) 1448 _worklist.push(u); 1449 } 1450 } 1451 // If changed initialization activity, check dependent Stores 1452 if (use_op == Op_Allocate || use_op == Op_AllocateArray) { 1453 InitializeNode* init = use->as_Allocate()->initialization(); 1454 if (init != NULL) { 1455 Node* imem = init->proj_out(TypeFunc::Memory); 1456 if (imem != NULL) add_users_to_worklist0(imem); 1457 } 1458 } 1459 if (use_op == Op_Initialize) { 1460 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory); 1461 if (imem != NULL) add_users_to_worklist0(imem); 1462 } 1463 } 1464 } 1465 1466 /** 1467 * Remove the speculative part of all types that we know of 1468 */ 1469 void PhaseIterGVN::remove_speculative_types() { 1470 assert(UseTypeSpeculation, "speculation is off"); 1471 for (uint i = 0; i < _types.Size(); i++) { 1472 const Type* t = _types.fast_lookup(i); 1473 if (t != NULL) { 1474 _types.map(i, t->remove_speculative()); 1475 } 1476 } 1477 _table.check_no_speculative_types(); 1478 } 1479 1480 //============================================================================= 1481 #ifndef PRODUCT 1482 uint PhaseCCP::_total_invokes = 0; 1483 uint PhaseCCP::_total_constants = 0; 1484 #endif 1485 //------------------------------PhaseCCP--------------------------------------- 1486 // Conditional Constant Propagation, ala Wegman & Zadeck 1487 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) { 1488 NOT_PRODUCT( clear_constants(); ) 1489 assert( _worklist.size() == 0, "" ); 1490 // Clear out _nodes from IterGVN. Must be clear to transform call. 1491 _nodes.clear(); // Clear out from IterGVN 1492 analyze(); 1493 } 1494 1495 #ifndef PRODUCT 1496 //------------------------------~PhaseCCP-------------------------------------- 1497 PhaseCCP::~PhaseCCP() { 1498 inc_invokes(); 1499 _total_constants += count_constants(); 1500 } 1501 #endif 1502 1503 1504 #ifdef ASSERT 1505 static bool ccp_type_widens(const Type* t, const Type* t0) { 1506 assert(t->meet(t0) == t, "Not monotonic"); 1507 switch (t->base() == t0->base() ? t->base() : Type::Top) { 1508 case Type::Int: 1509 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases"); 1510 break; 1511 case Type::Long: 1512 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases"); 1513 break; 1514 } 1515 return true; 1516 } 1517 #endif //ASSERT 1518 1519 //------------------------------analyze---------------------------------------- 1520 void PhaseCCP::analyze() { 1521 // Initialize all types to TOP, optimistic analysis 1522 for (int i = C->unique() - 1; i >= 0; i--) { 1523 _types.map(i,Type::TOP); 1524 } 1525 1526 // Push root onto worklist 1527 Unique_Node_List worklist; 1528 worklist.push(C->root()); 1529 1530 // Pull from worklist; compute new value; push changes out. 1531 // This loop is the meat of CCP. 1532 while( worklist.size() ) { 1533 Node *n = worklist.pop(); 1534 const Type *t = n->Value(this); 1535 if (t != type(n)) { 1536 assert(ccp_type_widens(t, type(n)), "ccp type must widen"); 1537 #ifndef PRODUCT 1538 if( TracePhaseCCP ) { 1539 t->dump(); 1540 do { tty->print("\t"); } while (tty->position() < 16); 1541 n->dump(); 1542 } 1543 #endif 1544 set_type(n, t); 1545 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1546 Node* m = n->fast_out(i); // Get user 1547 if( m->is_Region() ) { // New path to Region? Must recheck Phis too 1548 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1549 Node* p = m->fast_out(i2); // Propagate changes to uses 1550 if( p->bottom_type() != type(p) ) // If not already bottomed out 1551 worklist.push(p); // Propagate change to user 1552 } 1553 } 1554 // If we changed the receiver type to a call, we need to revisit 1555 // the Catch following the call. It's looking for a non-NULL 1556 // receiver to know when to enable the regular fall-through path 1557 // in addition to the NullPtrException path 1558 if (m->is_Call()) { 1559 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1560 Node* p = m->fast_out(i2); // Propagate changes to uses 1561 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) 1562 worklist.push(p->unique_out()); 1563 } 1564 } 1565 if( m->bottom_type() != type(m) ) // If not already bottomed out 1566 worklist.push(m); // Propagate change to user 1567 } 1568 } 1569 } 1570 } 1571 1572 //------------------------------do_transform----------------------------------- 1573 // Top level driver for the recursive transformer 1574 void PhaseCCP::do_transform() { 1575 // Correct leaves of new-space Nodes; they point to old-space. 1576 C->set_root( transform(C->root())->as_Root() ); 1577 assert( C->top(), "missing TOP node" ); 1578 assert( C->root(), "missing root" ); 1579 1580 // Eagerly remove castPP nodes here. CastPP nodes might not be 1581 // removed in the subsequent IGVN phase if a node that changes 1582 // in(1) of a castPP is processed prior to the castPP node. 1583 for (uint i = 0; i < _worklist.size(); i++) { 1584 Node* n = _worklist.at(i); 1585 1586 if (n->is_ConstraintCast()) { 1587 Node* nn = n->Identity(this); 1588 if (nn != n) { 1589 replace_node(n, nn); 1590 --i; 1591 } 1592 } 1593 } 1594 } 1595 1596 //------------------------------transform-------------------------------------- 1597 // Given a Node in old-space, clone him into new-space. 1598 // Convert any of his old-space children into new-space children. 1599 Node *PhaseCCP::transform( Node *n ) { 1600 Node *new_node = _nodes[n->_idx]; // Check for transformed node 1601 if( new_node != NULL ) 1602 return new_node; // Been there, done that, return old answer 1603 new_node = transform_once(n); // Check for constant 1604 _nodes.map( n->_idx, new_node ); // Flag as having been cloned 1605 1606 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc 1607 GrowableArray <Node *> trstack(C->unique() >> 1); 1608 1609 trstack.push(new_node); // Process children of cloned node 1610 while ( trstack.is_nonempty() ) { 1611 Node *clone = trstack.pop(); 1612 uint cnt = clone->req(); 1613 for( uint i = 0; i < cnt; i++ ) { // For all inputs do 1614 Node *input = clone->in(i); 1615 if( input != NULL ) { // Ignore NULLs 1616 Node *new_input = _nodes[input->_idx]; // Check for cloned input node 1617 if( new_input == NULL ) { 1618 new_input = transform_once(input); // Check for constant 1619 _nodes.map( input->_idx, new_input );// Flag as having been cloned 1620 trstack.push(new_input); 1621 } 1622 assert( new_input == clone->in(i), "insanity check"); 1623 } 1624 } 1625 } 1626 return new_node; 1627 } 1628 1629 1630 //------------------------------transform_once--------------------------------- 1631 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant. 1632 Node *PhaseCCP::transform_once( Node *n ) { 1633 const Type *t = type(n); 1634 // Constant? Use constant Node instead 1635 if( t->singleton() ) { 1636 Node *nn = n; // Default is to return the original constant 1637 if( t == Type::TOP ) { 1638 // cache my top node on the Compile instance 1639 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) { 1640 C->set_cached_top_node(ConNode::make(Type::TOP)); 1641 set_type(C->top(), Type::TOP); 1642 } 1643 nn = C->top(); 1644 } 1645 if( !n->is_Con() ) { 1646 if( t != Type::TOP ) { 1647 nn = makecon(t); // ConNode::make(t); 1648 NOT_PRODUCT( inc_constants(); ) 1649 } else if( n->is_Region() ) { // Unreachable region 1650 // Note: nn == C->top() 1651 n->set_req(0, NULL); // Cut selfreference 1652 // Eagerly remove dead phis to avoid phis copies creation. 1653 for (DUIterator i = n->outs(); n->has_out(i); i++) { 1654 Node* m = n->out(i); 1655 if( m->is_Phi() ) { 1656 assert(type(m) == Type::TOP, "Unreachable region should not have live phis."); 1657 replace_node(m, nn); 1658 --i; // deleted this phi; rescan starting with next position 1659 } 1660 } 1661 } 1662 replace_node(n,nn); // Update DefUse edges for new constant 1663 } 1664 return nn; 1665 } 1666 1667 // If x is a TypeNode, capture any more-precise type permanently into Node 1668 if (t != n->bottom_type()) { 1669 hash_delete(n); // changing bottom type may force a rehash 1670 n->raise_bottom_type(t); 1671 _worklist.push(n); // n re-enters the hash table via the worklist 1672 } 1673 1674 // Idealize graph using DU info. Must clone() into new-space. 1675 // DU info is generally used to show profitability, progress or safety 1676 // (but generally not needed for correctness). 1677 Node *nn = n->Ideal_DU_postCCP(this); 1678 1679 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks 1680 switch( n->Opcode() ) { 1681 case Op_FastLock: // Revisit FastLocks for lock coarsening 1682 case Op_If: 1683 case Op_CountedLoopEnd: 1684 case Op_Region: 1685 case Op_Loop: 1686 case Op_CountedLoop: 1687 case Op_Conv2B: 1688 case Op_Opaque1: 1689 case Op_Opaque2: 1690 _worklist.push(n); 1691 break; 1692 default: 1693 break; 1694 } 1695 if( nn ) { 1696 _worklist.push(n); 1697 // Put users of 'n' onto worklist for second igvn transform 1698 add_users_to_worklist(n); 1699 return nn; 1700 } 1701 1702 return n; 1703 } 1704 1705 //---------------------------------saturate------------------------------------ 1706 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type, 1707 const Type* limit_type) const { 1708 const Type* wide_type = new_type->widen(old_type, limit_type); 1709 if (wide_type != new_type) { // did we widen? 1710 // If so, we may have widened beyond the limit type. Clip it back down. 1711 new_type = wide_type->filter(limit_type); 1712 } 1713 return new_type; 1714 } 1715 1716 //------------------------------print_statistics------------------------------- 1717 #ifndef PRODUCT 1718 void PhaseCCP::print_statistics() { 1719 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants); 1720 } 1721 #endif 1722 1723 1724 //============================================================================= 1725 #ifndef PRODUCT 1726 uint PhasePeephole::_total_peepholes = 0; 1727 #endif 1728 //------------------------------PhasePeephole---------------------------------- 1729 // Conditional Constant Propagation, ala Wegman & Zadeck 1730 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ) 1731 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) { 1732 NOT_PRODUCT( clear_peepholes(); ) 1733 } 1734 1735 #ifndef PRODUCT 1736 //------------------------------~PhasePeephole--------------------------------- 1737 PhasePeephole::~PhasePeephole() { 1738 _total_peepholes += count_peepholes(); 1739 } 1740 #endif 1741 1742 //------------------------------transform-------------------------------------- 1743 Node *PhasePeephole::transform( Node *n ) { 1744 ShouldNotCallThis(); 1745 return NULL; 1746 } 1747 1748 //------------------------------do_transform----------------------------------- 1749 void PhasePeephole::do_transform() { 1750 bool method_name_not_printed = true; 1751 1752 // Examine each basic block 1753 for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) { 1754 Block* block = _cfg.get_block(block_number); 1755 bool block_not_printed = true; 1756 1757 // and each instruction within a block 1758 uint end_index = block->number_of_nodes(); 1759 // block->end_idx() not valid after PhaseRegAlloc 1760 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) { 1761 Node *n = block->get_node(instruction_index); 1762 if( n->is_Mach() ) { 1763 MachNode *m = n->as_Mach(); 1764 int deleted_count = 0; 1765 // check for peephole opportunities 1766 MachNode *m2 = m->peephole(block, instruction_index, _regalloc, deleted_count); 1767 if( m2 != NULL ) { 1768 #ifndef PRODUCT 1769 if( PrintOptoPeephole ) { 1770 // Print method, first time only 1771 if( C->method() && method_name_not_printed ) { 1772 C->method()->print_short_name(); tty->cr(); 1773 method_name_not_printed = false; 1774 } 1775 // Print this block 1776 if( Verbose && block_not_printed) { 1777 tty->print_cr("in block"); 1778 block->dump(); 1779 block_not_printed = false; 1780 } 1781 // Print instructions being deleted 1782 for( int i = (deleted_count - 1); i >= 0; --i ) { 1783 block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr(); 1784 } 1785 tty->print_cr("replaced with"); 1786 // Print new instruction 1787 m2->format(_regalloc); 1788 tty->print("\n\n"); 1789 } 1790 #endif 1791 // Remove old nodes from basic block and update instruction_index 1792 // (old nodes still exist and may have edges pointing to them 1793 // as register allocation info is stored in the allocator using 1794 // the node index to live range mappings.) 1795 uint safe_instruction_index = (instruction_index - deleted_count); 1796 for( ; (instruction_index > safe_instruction_index); --instruction_index ) { 1797 block->remove_node( instruction_index ); 1798 } 1799 // install new node after safe_instruction_index 1800 block->insert_node(m2, safe_instruction_index + 1); 1801 end_index = block->number_of_nodes() - 1; // Recompute new block size 1802 NOT_PRODUCT( inc_peepholes(); ) 1803 } 1804 } 1805 } 1806 } 1807 } 1808 1809 //------------------------------print_statistics------------------------------- 1810 #ifndef PRODUCT 1811 void PhasePeephole::print_statistics() { 1812 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes); 1813 } 1814 #endif 1815 1816 1817 //============================================================================= 1818 //------------------------------set_req_X-------------------------------------- 1819 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) { 1820 assert( is_not_dead(n), "can not use dead node"); 1821 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" ); 1822 Node *old = in(i); 1823 set_req(i, n); 1824 1825 // old goes dead? 1826 if( old ) { 1827 switch (old->outcnt()) { 1828 case 0: 1829 // Put into the worklist to kill later. We do not kill it now because the 1830 // recursive kill will delete the current node (this) if dead-loop exists 1831 if (!old->is_top()) 1832 igvn->_worklist.push( old ); 1833 break; 1834 case 1: 1835 if( old->is_Store() || old->has_special_unique_user() ) 1836 igvn->add_users_to_worklist( old ); 1837 break; 1838 case 2: 1839 if( old->is_Store() ) 1840 igvn->add_users_to_worklist( old ); 1841 if( old->Opcode() == Op_Region ) 1842 igvn->_worklist.push(old); 1843 break; 1844 case 3: 1845 if( old->Opcode() == Op_Region ) { 1846 igvn->_worklist.push(old); 1847 igvn->add_users_to_worklist( old ); 1848 } 1849 break; 1850 default: 1851 break; 1852 } 1853 } 1854 1855 } 1856 1857 //-------------------------------replace_by----------------------------------- 1858 // Using def-use info, replace one node for another. Follow the def-use info 1859 // to all users of the OLD node. Then make all uses point to the NEW node. 1860 void Node::replace_by(Node *new_node) { 1861 assert(!is_top(), "top node has no DU info"); 1862 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) { 1863 Node* use = last_out(i); 1864 uint uses_found = 0; 1865 for (uint j = 0; j < use->len(); j++) { 1866 if (use->in(j) == this) { 1867 if (j < use->req()) 1868 use->set_req(j, new_node); 1869 else use->set_prec(j, new_node); 1870 uses_found++; 1871 } 1872 } 1873 i -= uses_found; // we deleted 1 or more copies of this edge 1874 } 1875 } 1876 1877 //============================================================================= 1878 //----------------------------------------------------------------------------- 1879 void Type_Array::grow( uint i ) { 1880 if( !_max ) { 1881 _max = 1; 1882 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) ); 1883 _types[0] = NULL; 1884 } 1885 uint old = _max; 1886 while( i >= _max ) _max <<= 1; // Double to fit 1887 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*)); 1888 memset( &_types[old], 0, (_max-old)*sizeof(Type*) ); 1889 } 1890 1891 //------------------------------dump------------------------------------------- 1892 #ifndef PRODUCT 1893 void Type_Array::dump() const { 1894 uint max = Size(); 1895 for( uint i = 0; i < max; i++ ) { 1896 if( _types[i] != NULL ) { 1897 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr(); 1898 } 1899 } 1900 } 1901 #endif