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/connode.hpp" 31 #include "opto/idealGraphPrinter.hpp" 32 #include "opto/loopnode.hpp" 33 #include "opto/machnode.hpp" 34 #include "opto/opcodes.hpp" 35 #include "opto/phaseX.hpp" 36 #include "opto/regalloc.hpp" 37 #include "opto/rootnode.hpp" 38 39 //============================================================================= 40 #define NODE_HASH_MINIMUM_SIZE 255 41 //------------------------------NodeHash--------------------------------------- 42 NodeHash::NodeHash(uint est_max_size) : 43 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), 44 _a(Thread::current()->resource_area()), 45 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ), 46 _inserts(0), _insert_limit( insert_limit() ), 47 _look_probes(0), _lookup_hits(0), _lookup_misses(0), 48 _total_insert_probes(0), _total_inserts(0), 49 _insert_probes(0), _grows(0) { 50 // _sentinel must be in the current node space 51 _sentinel = new (Compile::current()) ProjNode(NULL, TypeFunc::Control); 52 memset(_table,0,sizeof(Node*)*_max); 53 } 54 55 //------------------------------NodeHash--------------------------------------- 56 NodeHash::NodeHash(Arena *arena, uint est_max_size) : 57 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), 58 _a(arena), 59 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), 60 _inserts(0), _insert_limit( insert_limit() ), 61 _look_probes(0), _lookup_hits(0), _lookup_misses(0), 62 _delete_probes(0), _delete_hits(0), _delete_misses(0), 63 _total_insert_probes(0), _total_inserts(0), 64 _insert_probes(0), _grows(0) { 65 // _sentinel must be in the current node space 66 _sentinel = new (Compile::current()) ProjNode(NULL, TypeFunc::Control); 67 memset(_table,0,sizeof(Node*)*_max); 68 } 69 70 //------------------------------NodeHash--------------------------------------- 71 NodeHash::NodeHash(NodeHash *nh) { 72 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= 73 // just copy in all the fields 74 *this = *nh; 75 // nh->_sentinel must be in the current node space 76 } 77 78 void NodeHash::replace_with(NodeHash *nh) { 79 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= 80 // just copy in all the fields 81 *this = *nh; 82 // nh->_sentinel must be in the current node space 83 } 84 85 //------------------------------hash_find-------------------------------------- 86 // Find in hash table 87 Node *NodeHash::hash_find( const Node *n ) { 88 // ((Node*)n)->set_hash( n->hash() ); 89 uint hash = n->hash(); 90 if (hash == Node::NO_HASH) { 91 debug_only( _lookup_misses++ ); 92 return NULL; 93 } 94 uint key = hash & (_max-1); 95 uint stride = key | 0x01; 96 debug_only( _look_probes++ ); 97 Node *k = _table[key]; // Get hashed value 98 if( !k ) { // ?Miss? 99 debug_only( _lookup_misses++ ); 100 return NULL; // Miss! 101 } 102 103 int op = n->Opcode(); 104 uint req = n->req(); 105 while( 1 ) { // While probing hash table 106 if( k->req() == req && // Same count of inputs 107 k->Opcode() == op ) { // Same Opcode 108 for( uint i=0; i<req; i++ ) 109 if( n->in(i)!=k->in(i)) // Different inputs? 110 goto collision; // "goto" is a speed hack... 111 if( n->cmp(*k) ) { // Check for any special bits 112 debug_only( _lookup_hits++ ); 113 return k; // Hit! 114 } 115 } 116 collision: 117 debug_only( _look_probes++ ); 118 key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime 119 k = _table[key]; // Get hashed value 120 if( !k ) { // ?Miss? 121 debug_only( _lookup_misses++ ); 122 return NULL; // Miss! 123 } 124 } 125 ShouldNotReachHere(); 126 return NULL; 127 } 128 129 //------------------------------hash_find_insert------------------------------- 130 // Find in hash table, insert if not already present 131 // Used to preserve unique entries in hash table 132 Node *NodeHash::hash_find_insert( Node *n ) { 133 // n->set_hash( ); 134 uint hash = n->hash(); 135 if (hash == Node::NO_HASH) { 136 debug_only( _lookup_misses++ ); 137 return NULL; 138 } 139 uint key = hash & (_max-1); 140 uint stride = key | 0x01; // stride must be relatively prime to table siz 141 uint first_sentinel = 0; // replace a sentinel if seen. 142 debug_only( _look_probes++ ); 143 Node *k = _table[key]; // Get hashed value 144 if( !k ) { // ?Miss? 145 debug_only( _lookup_misses++ ); 146 _table[key] = n; // Insert into table! 147 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 148 check_grow(); // Grow table if insert hit limit 149 return NULL; // Miss! 150 } 151 else if( k == _sentinel ) { 152 first_sentinel = key; // Can insert here 153 } 154 155 int op = n->Opcode(); 156 uint req = n->req(); 157 while( 1 ) { // While probing hash table 158 if( k->req() == req && // Same count of inputs 159 k->Opcode() == op ) { // Same Opcode 160 for( uint i=0; i<req; i++ ) 161 if( n->in(i)!=k->in(i)) // Different inputs? 162 goto collision; // "goto" is a speed hack... 163 if( n->cmp(*k) ) { // Check for any special bits 164 debug_only( _lookup_hits++ ); 165 return k; // Hit! 166 } 167 } 168 collision: 169 debug_only( _look_probes++ ); 170 key = (key + stride) & (_max-1); // Stride through table w/ relative prime 171 k = _table[key]; // Get hashed value 172 if( !k ) { // ?Miss? 173 debug_only( _lookup_misses++ ); 174 key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel? 175 _table[key] = n; // Insert into table! 176 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 177 check_grow(); // Grow table if insert hit limit 178 return NULL; // Miss! 179 } 180 else if( first_sentinel == 0 && k == _sentinel ) { 181 first_sentinel = key; // Can insert here 182 } 183 184 } 185 ShouldNotReachHere(); 186 return NULL; 187 } 188 189 //------------------------------hash_insert------------------------------------ 190 // Insert into hash table 191 void NodeHash::hash_insert( Node *n ) { 192 // // "conflict" comments -- print nodes that conflict 193 // bool conflict = false; 194 // n->set_hash(); 195 uint hash = n->hash(); 196 if (hash == Node::NO_HASH) { 197 return; 198 } 199 check_grow(); 200 uint key = hash & (_max-1); 201 uint stride = key | 0x01; 202 203 while( 1 ) { // While probing hash table 204 debug_only( _insert_probes++ ); 205 Node *k = _table[key]; // Get hashed value 206 if( !k || (k == _sentinel) ) break; // Found a slot 207 assert( k != n, "already inserted" ); 208 // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; } 209 key = (key + stride) & (_max-1); // Stride through table w/ relative prime 210 } 211 _table[key] = n; // Insert into table! 212 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 213 // if( conflict ) { n->dump(); } 214 } 215 216 //------------------------------hash_delete------------------------------------ 217 // Replace in hash table with sentinel 218 bool NodeHash::hash_delete( const Node *n ) { 219 Node *k; 220 uint hash = n->hash(); 221 if (hash == Node::NO_HASH) { 222 debug_only( _delete_misses++ ); 223 return false; 224 } 225 uint key = hash & (_max-1); 226 uint stride = key | 0x01; 227 debug_only( uint counter = 0; ); 228 for( ; /* (k != NULL) && (k != _sentinel) */; ) { 229 debug_only( counter++ ); 230 debug_only( _delete_probes++ ); 231 k = _table[key]; // Get hashed value 232 if( !k ) { // Miss? 233 debug_only( _delete_misses++ ); 234 #ifdef ASSERT 235 if( VerifyOpto ) { 236 for( uint i=0; i < _max; i++ ) 237 assert( _table[i] != n, "changed edges with rehashing" ); 238 } 239 #endif 240 return false; // Miss! Not in chain 241 } 242 else if( n == k ) { 243 debug_only( _delete_hits++ ); 244 _table[key] = _sentinel; // Hit! Label as deleted entry 245 debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table. 246 return true; 247 } 248 else { 249 // collision: move through table with prime offset 250 key = (key + stride/*7*/) & (_max-1); 251 assert( counter <= _insert_limit, "Cycle in hash-table"); 252 } 253 } 254 ShouldNotReachHere(); 255 return false; 256 } 257 258 //------------------------------round_up--------------------------------------- 259 // Round up to nearest power of 2 260 uint NodeHash::round_up( uint x ) { 261 x += (x>>2); // Add 25% slop 262 if( x <16 ) return 16; // Small stuff 263 uint i=16; 264 while( i < x ) i <<= 1; // Double to fit 265 return i; // Return hash table size 266 } 267 268 //------------------------------grow------------------------------------------- 269 // Grow _table to next power of 2 and insert old entries 270 void NodeHash::grow() { 271 // Record old state 272 uint old_max = _max; 273 Node **old_table = _table; 274 // Construct new table with twice the space 275 _grows++; 276 _total_inserts += _inserts; 277 _total_insert_probes += _insert_probes; 278 _inserts = 0; 279 _insert_probes = 0; 280 _max = _max << 1; 281 _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) ); 282 memset(_table,0,sizeof(Node*)*_max); 283 _insert_limit = insert_limit(); 284 // Insert old entries into the new table 285 for( uint i = 0; i < old_max; i++ ) { 286 Node *m = *old_table++; 287 if( !m || m == _sentinel ) continue; 288 debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table. 289 hash_insert(m); 290 } 291 } 292 293 //------------------------------clear------------------------------------------ 294 // Clear all entries in _table to NULL but keep storage 295 void NodeHash::clear() { 296 #ifdef ASSERT 297 // Unlock all nodes upon removal from table. 298 for (uint i = 0; i < _max; i++) { 299 Node* n = _table[i]; 300 if (!n || n == _sentinel) continue; 301 n->exit_hash_lock(); 302 } 303 #endif 304 305 memset( _table, 0, _max * sizeof(Node*) ); 306 } 307 308 //-----------------------remove_useless_nodes---------------------------------- 309 // Remove useless nodes from value table, 310 // implementation does not depend on hash function 311 void NodeHash::remove_useless_nodes(VectorSet &useful) { 312 313 // Dead nodes in the hash table inherited from GVN should not replace 314 // existing nodes, remove dead nodes. 315 uint max = size(); 316 Node *sentinel_node = sentinel(); 317 for( uint i = 0; i < max; ++i ) { 318 Node *n = at(i); 319 if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) { 320 debug_only(n->exit_hash_lock()); // Unlock the node when removed 321 _table[i] = sentinel_node; // Replace with placeholder 322 } 323 } 324 } 325 326 327 void NodeHash::check_no_speculative_types() { 328 #ifdef ASSERT 329 uint max = size(); 330 Node *sentinel_node = sentinel(); 331 for (uint i = 0; i < max; ++i) { 332 Node *n = at(i); 333 if(n != NULL && n != sentinel_node && n->is_Type()) { 334 TypeNode* tn = n->as_Type(); 335 const Type* t = tn->type(); 336 const Type* t_no_spec = t->remove_speculative(); 337 assert(t == t_no_spec, "dead node in hash table or missed node during speculative cleanup"); 338 } 339 } 340 #endif 341 } 342 343 #ifndef PRODUCT 344 //------------------------------dump------------------------------------------- 345 // Dump statistics for the hash table 346 void NodeHash::dump() { 347 _total_inserts += _inserts; 348 _total_insert_probes += _insert_probes; 349 if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) { 350 if (WizardMode) { 351 for (uint i=0; i<_max; i++) { 352 if (_table[i]) 353 tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx); 354 } 355 } 356 tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max); 357 tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0); 358 tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses)); 359 tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts); 360 // sentinels increase lookup cost, but not insert cost 361 assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function"); 362 assert( _inserts+(_inserts>>3) < _max, "table too full" ); 363 assert( _inserts*3+100 >= _insert_probes, "bad hash function" ); 364 } 365 } 366 367 Node *NodeHash::find_index(uint idx) { // For debugging 368 // Find an entry by its index value 369 for( uint i = 0; i < _max; i++ ) { 370 Node *m = _table[i]; 371 if( !m || m == _sentinel ) continue; 372 if( m->_idx == (uint)idx ) return m; 373 } 374 return NULL; 375 } 376 #endif 377 378 #ifdef ASSERT 379 NodeHash::~NodeHash() { 380 // Unlock all nodes upon destruction of table. 381 if (_table != (Node**)badAddress) clear(); 382 } 383 384 void NodeHash::operator=(const NodeHash& nh) { 385 // Unlock all nodes upon replacement of table. 386 if (&nh == this) return; 387 if (_table != (Node**)badAddress) clear(); 388 memcpy(this, &nh, sizeof(*this)); 389 // Do not increment hash_lock counts again. 390 // Instead, be sure we never again use the source table. 391 ((NodeHash*)&nh)->_table = (Node**)badAddress; 392 } 393 394 395 #endif 396 397 398 //============================================================================= 399 //------------------------------PhaseRemoveUseless----------------------------- 400 // 1) Use a breadthfirst walk to collect useful nodes reachable from root. 401 PhaseRemoveUseless::PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ) : Phase(Remove_Useless), 402 _useful(Thread::current()->resource_area()) { 403 404 // Implementation requires 'UseLoopSafepoints == true' and an edge from root 405 // to each SafePointNode at a backward branch. Inserted in add_safepoint(). 406 if( !UseLoopSafepoints || !OptoRemoveUseless ) return; 407 408 // Identify nodes that are reachable from below, useful. 409 C->identify_useful_nodes(_useful); 410 // Update dead node list 411 C->update_dead_node_list(_useful); 412 413 // Remove all useless nodes from PhaseValues' recorded types 414 // Must be done before disconnecting nodes to preserve hash-table-invariant 415 gvn->remove_useless_nodes(_useful.member_set()); 416 417 // Remove all useless nodes from future worklist 418 worklist->remove_useless_nodes(_useful.member_set()); 419 420 // Disconnect 'useless' nodes that are adjacent to useful nodes 421 C->remove_useless_nodes(_useful); 422 423 // Remove edges from "root" to each SafePoint at a backward branch. 424 // They were inserted during parsing (see add_safepoint()) to make infinite 425 // loops without calls or exceptions visible to root, i.e., useful. 426 Node *root = C->root(); 427 if( root != NULL ) { 428 for( uint i = root->req(); i < root->len(); ++i ) { 429 Node *n = root->in(i); 430 if( n != NULL && n->is_SafePoint() ) { 431 root->rm_prec(i); 432 --i; 433 } 434 } 435 } 436 } 437 438 439 //============================================================================= 440 //------------------------------PhaseTransform--------------------------------- 441 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum), 442 _arena(Thread::current()->resource_area()), 443 _nodes(_arena), 444 _types(_arena) 445 { 446 init_con_caches(); 447 #ifndef PRODUCT 448 clear_progress(); 449 clear_transforms(); 450 set_allow_progress(true); 451 #endif 452 // Force allocation for currently existing nodes 453 _types.map(C->unique(), NULL); 454 } 455 456 //------------------------------PhaseTransform--------------------------------- 457 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum), 458 _arena(arena), 459 _nodes(arena), 460 _types(arena) 461 { 462 init_con_caches(); 463 #ifndef PRODUCT 464 clear_progress(); 465 clear_transforms(); 466 set_allow_progress(true); 467 #endif 468 // Force allocation for currently existing nodes 469 _types.map(C->unique(), NULL); 470 } 471 472 //------------------------------PhaseTransform--------------------------------- 473 // Initialize with previously generated type information 474 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum), 475 _arena(pt->_arena), 476 _nodes(pt->_nodes), 477 _types(pt->_types) 478 { 479 init_con_caches(); 480 #ifndef PRODUCT 481 clear_progress(); 482 clear_transforms(); 483 set_allow_progress(true); 484 #endif 485 } 486 487 void PhaseTransform::init_con_caches() { 488 memset(_icons,0,sizeof(_icons)); 489 memset(_lcons,0,sizeof(_lcons)); 490 memset(_zcons,0,sizeof(_zcons)); 491 } 492 493 494 //--------------------------------find_int_type-------------------------------- 495 const TypeInt* PhaseTransform::find_int_type(Node* n) { 496 if (n == NULL) return NULL; 497 // Call type_or_null(n) to determine node's type since we might be in 498 // parse phase and call n->Value() may return wrong type. 499 // (For example, a phi node at the beginning of loop parsing is not ready.) 500 const Type* t = type_or_null(n); 501 if (t == NULL) return NULL; 502 return t->isa_int(); 503 } 504 505 506 //-------------------------------find_long_type-------------------------------- 507 const TypeLong* PhaseTransform::find_long_type(Node* n) { 508 if (n == NULL) return NULL; 509 // (See comment above on type_or_null.) 510 const Type* t = type_or_null(n); 511 if (t == NULL) return NULL; 512 return t->isa_long(); 513 } 514 515 516 #ifndef PRODUCT 517 void PhaseTransform::dump_old2new_map() const { 518 _nodes.dump(); 519 } 520 521 void PhaseTransform::dump_new( uint nidx ) const { 522 for( uint i=0; i<_nodes.Size(); i++ ) 523 if( _nodes[i] && _nodes[i]->_idx == nidx ) { 524 _nodes[i]->dump(); 525 tty->cr(); 526 tty->print_cr("Old index= %d",i); 527 return; 528 } 529 tty->print_cr("Node %d not found in the new indices", nidx); 530 } 531 532 //------------------------------dump_types------------------------------------- 533 void PhaseTransform::dump_types( ) const { 534 _types.dump(); 535 } 536 537 //------------------------------dump_nodes_and_types--------------------------- 538 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) { 539 VectorSet visited(Thread::current()->resource_area()); 540 dump_nodes_and_types_recur( root, depth, only_ctrl, visited ); 541 } 542 543 //------------------------------dump_nodes_and_types_recur--------------------- 544 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) { 545 if( !n ) return; 546 if( depth == 0 ) return; 547 if( visited.test_set(n->_idx) ) return; 548 for( uint i=0; i<n->len(); i++ ) { 549 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue; 550 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited ); 551 } 552 n->dump(); 553 if (type_or_null(n) != NULL) { 554 tty->print(" "); type(n)->dump(); tty->cr(); 555 } 556 } 557 558 #endif 559 560 561 //============================================================================= 562 //------------------------------PhaseValues------------------------------------ 563 // Set minimum table size to "255" 564 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) { 565 NOT_PRODUCT( clear_new_values(); ) 566 } 567 568 //------------------------------PhaseValues------------------------------------ 569 // Set minimum table size to "255" 570 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ), 571 _table(&ptv->_table) { 572 NOT_PRODUCT( clear_new_values(); ) 573 } 574 575 //------------------------------PhaseValues------------------------------------ 576 // Used by +VerifyOpto. Clear out hash table but copy _types array. 577 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ), 578 _table(ptv->arena(),ptv->_table.size()) { 579 NOT_PRODUCT( clear_new_values(); ) 580 } 581 582 //------------------------------~PhaseValues----------------------------------- 583 #ifndef PRODUCT 584 PhaseValues::~PhaseValues() { 585 _table.dump(); 586 587 // Statistics for value progress and efficiency 588 if( PrintCompilation && Verbose && WizardMode ) { 589 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)", 590 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values()); 591 if( made_transforms() != 0 ) { 592 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() ); 593 } else { 594 tty->cr(); 595 } 596 } 597 } 598 #endif 599 600 //------------------------------makecon---------------------------------------- 601 ConNode* PhaseTransform::makecon(const Type *t) { 602 assert(t->singleton(), "must be a constant"); 603 assert(!t->empty() || t == Type::TOP, "must not be vacuous range"); 604 switch (t->base()) { // fast paths 605 case Type::Half: 606 case Type::Top: return (ConNode*) C->top(); 607 case Type::Int: return intcon( t->is_int()->get_con() ); 608 case Type::Long: return longcon( t->is_long()->get_con() ); 609 } 610 if (t->is_zero_type()) 611 return zerocon(t->basic_type()); 612 return uncached_makecon(t); 613 } 614 615 //--------------------------uncached_makecon----------------------------------- 616 // Make an idealized constant - one of ConINode, ConPNode, etc. 617 ConNode* PhaseValues::uncached_makecon(const Type *t) { 618 assert(t->singleton(), "must be a constant"); 619 ConNode* x = ConNode::make(C, t); 620 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering 621 if (k == NULL) { 622 set_type(x, t); // Missed, provide type mapping 623 GrowableArray<Node_Notes*>* nna = C->node_note_array(); 624 if (nna != NULL) { 625 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true); 626 loc->clear(); // do not put debug info on constants 627 } 628 } else { 629 x->destruct(); // Hit, destroy duplicate constant 630 x = k; // use existing constant 631 } 632 return x; 633 } 634 635 //------------------------------intcon----------------------------------------- 636 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))" 637 ConINode* PhaseTransform::intcon(int i) { 638 // Small integer? Check cache! Check that cached node is not dead 639 if (i >= _icon_min && i <= _icon_max) { 640 ConINode* icon = _icons[i-_icon_min]; 641 if (icon != NULL && icon->in(TypeFunc::Control) != NULL) 642 return icon; 643 } 644 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i)); 645 assert(icon->is_Con(), ""); 646 if (i >= _icon_min && i <= _icon_max) 647 _icons[i-_icon_min] = icon; // Cache small integers 648 return icon; 649 } 650 651 //------------------------------longcon---------------------------------------- 652 // Fast long constant. 653 ConLNode* PhaseTransform::longcon(jlong l) { 654 // Small integer? Check cache! Check that cached node is not dead 655 if (l >= _lcon_min && l <= _lcon_max) { 656 ConLNode* lcon = _lcons[l-_lcon_min]; 657 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL) 658 return lcon; 659 } 660 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l)); 661 assert(lcon->is_Con(), ""); 662 if (l >= _lcon_min && l <= _lcon_max) 663 _lcons[l-_lcon_min] = lcon; // Cache small integers 664 return lcon; 665 } 666 667 //------------------------------zerocon----------------------------------------- 668 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))" 669 ConNode* PhaseTransform::zerocon(BasicType bt) { 670 assert((uint)bt <= _zcon_max, "domain check"); 671 ConNode* zcon = _zcons[bt]; 672 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL) 673 return zcon; 674 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt)); 675 _zcons[bt] = zcon; 676 return zcon; 677 } 678 679 680 681 //============================================================================= 682 //------------------------------transform-------------------------------------- 683 // Return a node which computes the same function as this node, but in a 684 // faster or cheaper fashion. 685 Node *PhaseGVN::transform( Node *n ) { 686 return transform_no_reclaim(n); 687 } 688 689 //------------------------------transform-------------------------------------- 690 // Return a node which computes the same function as this node, but 691 // in a faster or cheaper fashion. 692 Node *PhaseGVN::transform_no_reclaim( Node *n ) { 693 NOT_PRODUCT( set_transforms(); ) 694 695 // Apply the Ideal call in a loop until it no longer applies 696 Node *k = n; 697 NOT_PRODUCT( uint loop_count = 0; ) 698 while( 1 ) { 699 Node *i = k->Ideal(this, /*can_reshape=*/false); 700 if( !i ) break; 701 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" ); 702 k = i; 703 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform"); 704 } 705 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } ) 706 707 708 // If brand new node, make space in type array. 709 ensure_type_or_null(k); 710 711 // Since I just called 'Value' to compute the set of run-time values 712 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 713 // cache Value. Later requests for the local phase->type of this Node can 714 // use the cached Value instead of suffering with 'bottom_type'. 715 const Type *t = k->Value(this); // Get runtime Value set 716 assert(t != NULL, "value sanity"); 717 if (type_or_null(k) != t) { 718 #ifndef PRODUCT 719 // Do not count initial visit to node as a transformation 720 if (type_or_null(k) == NULL) { 721 inc_new_values(); 722 set_progress(); 723 } 724 #endif 725 set_type(k, t); 726 // If k is a TypeNode, capture any more-precise type permanently into Node 727 k->raise_bottom_type(t); 728 } 729 730 if( t->singleton() && !k->is_Con() ) { 731 NOT_PRODUCT( set_progress(); ) 732 return makecon(t); // Turn into a constant 733 } 734 735 // Now check for Identities 736 Node *i = k->Identity(this); // Look for a nearby replacement 737 if( i != k ) { // Found? Return replacement! 738 NOT_PRODUCT( set_progress(); ) 739 return i; 740 } 741 742 // Global Value Numbering 743 i = hash_find_insert(k); // Insert if new 744 if( i && (i != k) ) { 745 // Return the pre-existing node 746 NOT_PRODUCT( set_progress(); ) 747 return i; 748 } 749 750 // Return Idealized original 751 return k; 752 } 753 754 #ifdef ASSERT 755 //------------------------------dead_loop_check-------------------------------- 756 // Check for a simple dead loop when a data node references itself directly 757 // or through an other data node excluding cons and phis. 758 void PhaseGVN::dead_loop_check( Node *n ) { 759 // Phi may reference itself in a loop 760 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) { 761 // Do 2 levels check and only data inputs. 762 bool no_dead_loop = true; 763 uint cnt = n->req(); 764 for (uint i = 1; i < cnt && no_dead_loop; i++) { 765 Node *in = n->in(i); 766 if (in == n) { 767 no_dead_loop = false; 768 } else if (in != NULL && !in->is_dead_loop_safe()) { 769 uint icnt = in->req(); 770 for (uint j = 1; j < icnt && no_dead_loop; j++) { 771 if (in->in(j) == n || in->in(j) == in) 772 no_dead_loop = false; 773 } 774 } 775 } 776 if (!no_dead_loop) n->dump(3); 777 assert(no_dead_loop, "dead loop detected"); 778 } 779 } 780 #endif 781 782 //============================================================================= 783 //------------------------------PhaseIterGVN----------------------------------- 784 // Initialize hash table to fresh and clean for +VerifyOpto 785 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ), 786 _stack(C->live_nodes() >> 1), 787 _delay_transform(false) { 788 } 789 790 //------------------------------PhaseIterGVN----------------------------------- 791 // Initialize with previous PhaseIterGVN info; used by PhaseCCP 792 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn), 793 _worklist( igvn->_worklist ), 794 _stack( igvn->_stack ), 795 _delay_transform(igvn->_delay_transform) 796 { 797 } 798 799 //------------------------------PhaseIterGVN----------------------------------- 800 // Initialize with previous PhaseGVN info from Parser 801 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn), 802 _worklist(*C->for_igvn()), 803 // TODO: Before incremental inlining it was allocated only once and it was fine. Now that 804 // the constructor is used in incremental inlining, this consumes too much memory: 805 // _stack(C->live_nodes() >> 1), 806 // So, as a band-aid, we replace this by: 807 _stack(C->comp_arena(), 32), 808 _delay_transform(false) 809 { 810 uint max; 811 812 // Dead nodes in the hash table inherited from GVN were not treated as 813 // roots during def-use info creation; hence they represent an invisible 814 // use. Clear them out. 815 max = _table.size(); 816 for( uint i = 0; i < max; ++i ) { 817 Node *n = _table.at(i); 818 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) { 819 if( n->is_top() ) continue; 820 assert( false, "Parse::remove_useless_nodes missed this node"); 821 hash_delete(n); 822 } 823 } 824 825 // Any Phis or Regions on the worklist probably had uses that could not 826 // make more progress because the uses were made while the Phis and Regions 827 // were in half-built states. Put all uses of Phis and Regions on worklist. 828 max = _worklist.size(); 829 for( uint j = 0; j < max; j++ ) { 830 Node *n = _worklist.at(j); 831 uint uop = n->Opcode(); 832 if( uop == Op_Phi || uop == Op_Region || 833 n->is_Type() || 834 n->is_Mem() ) 835 add_users_to_worklist(n); 836 } 837 } 838 839 840 #ifndef PRODUCT 841 void PhaseIterGVN::verify_step(Node* n) { 842 _verify_window[_verify_counter % _verify_window_size] = n; 843 ++_verify_counter; 844 ResourceMark rm; 845 ResourceArea *area = Thread::current()->resource_area(); 846 VectorSet old_space(area), new_space(area); 847 if (C->unique() < 1000 || 848 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) { 849 ++_verify_full_passes; 850 Node::verify_recur(C->root(), -1, old_space, new_space); 851 } 852 const int verify_depth = 4; 853 for ( int i = 0; i < _verify_window_size; i++ ) { 854 Node* n = _verify_window[i]; 855 if ( n == NULL ) continue; 856 if( n->in(0) == NodeSentinel ) { // xform_idom 857 _verify_window[i] = n->in(1); 858 --i; continue; 859 } 860 // Typical fanout is 1-2, so this call visits about 6 nodes. 861 Node::verify_recur(n, verify_depth, old_space, new_space); 862 } 863 } 864 #endif 865 866 867 //------------------------------init_worklist---------------------------------- 868 // Initialize worklist for each node. 869 void PhaseIterGVN::init_worklist( Node *n ) { 870 if( _worklist.member(n) ) return; 871 _worklist.push(n); 872 uint cnt = n->req(); 873 for( uint i =0 ; i < cnt; i++ ) { 874 Node *m = n->in(i); 875 if( m ) init_worklist(m); 876 } 877 } 878 879 //------------------------------optimize--------------------------------------- 880 void PhaseIterGVN::optimize() { 881 debug_only(uint num_processed = 0;); 882 #ifndef PRODUCT 883 { 884 _verify_counter = 0; 885 _verify_full_passes = 0; 886 for ( int i = 0; i < _verify_window_size; i++ ) { 887 _verify_window[i] = NULL; 888 } 889 } 890 #endif 891 892 #ifdef ASSERT 893 Node* prev = NULL; 894 uint rep_cnt = 0; 895 #endif 896 uint loop_count = 0; 897 898 // Pull from worklist; transform node; 899 // If node has changed: update edge info and put uses on worklist. 900 while( _worklist.size() ) { 901 if (C->check_node_count(NodeLimitFudgeFactor * 2, 902 "out of nodes optimizing method")) { 903 return; 904 } 905 Node *n = _worklist.pop(); 906 if (++loop_count >= K * C->live_nodes()) { 907 debug_only(n->dump(4);) 908 assert(false, "infinite loop in PhaseIterGVN::optimize"); 909 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize"); 910 return; 911 } 912 #ifdef ASSERT 913 if (n == prev) { 914 if (++rep_cnt > 3) { 915 n->dump(4); 916 assert(false, "loop in Ideal transformation"); 917 } 918 } else { 919 rep_cnt = 0; 920 } 921 prev = n; 922 #endif 923 if (TraceIterativeGVN && Verbose) { 924 tty->print(" Pop "); 925 NOT_PRODUCT( n->dump(); ) 926 debug_only(if( (num_processed++ % 100) == 0 ) _worklist.print_set();) 927 } 928 929 if (n->outcnt() != 0) { 930 931 #ifndef PRODUCT 932 uint wlsize = _worklist.size(); 933 const Type* oldtype = type_or_null(n); 934 #endif //PRODUCT 935 936 Node *nn = transform_old(n); 937 938 #ifndef PRODUCT 939 if (TraceIterativeGVN) { 940 const Type* newtype = type_or_null(n); 941 if (nn != n) { 942 // print old node 943 tty->print("< "); 944 if (oldtype != newtype && oldtype != NULL) { 945 oldtype->dump(); 946 } 947 do { tty->print("\t"); } while (tty->position() < 16); 948 tty->print("<"); 949 n->dump(); 950 } 951 if (oldtype != newtype || nn != n) { 952 // print new node and/or new type 953 if (oldtype == NULL) { 954 tty->print("* "); 955 } else if (nn != n) { 956 tty->print("> "); 957 } else { 958 tty->print("= "); 959 } 960 if (newtype == NULL) { 961 tty->print("null"); 962 } else { 963 newtype->dump(); 964 } 965 do { tty->print("\t"); } while (tty->position() < 16); 966 nn->dump(); 967 } 968 if (Verbose && wlsize < _worklist.size()) { 969 tty->print(" Push {"); 970 while (wlsize != _worklist.size()) { 971 Node* pushed = _worklist.at(wlsize++); 972 tty->print(" %d", pushed->_idx); 973 } 974 tty->print_cr(" }"); 975 } 976 } 977 if( VerifyIterativeGVN && nn != n ) { 978 verify_step((Node*) NULL); // ignore n, it might be subsumed 979 } 980 #endif 981 } else if (!n->is_top()) { 982 remove_dead_node(n); 983 } 984 } 985 986 #ifndef PRODUCT 987 C->verify_graph_edges(); 988 if( VerifyOpto && allow_progress() ) { 989 // Must turn off allow_progress to enable assert and break recursion 990 C->root()->verify(); 991 { // Check if any progress was missed using IterGVN 992 // Def-Use info enables transformations not attempted in wash-pass 993 // e.g. Region/Phi cleanup, ... 994 // Null-check elision -- may not have reached fixpoint 995 // do not propagate to dominated nodes 996 ResourceMark rm; 997 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean! 998 // Fill worklist completely 999 igvn2.init_worklist(C->root()); 1000 1001 igvn2.set_allow_progress(false); 1002 igvn2.optimize(); 1003 igvn2.set_allow_progress(true); 1004 } 1005 } 1006 if ( VerifyIterativeGVN && PrintOpto ) { 1007 if ( _verify_counter == _verify_full_passes ) 1008 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes", 1009 (int) _verify_full_passes); 1010 else 1011 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes", 1012 (int) _verify_counter, (int) _verify_full_passes); 1013 } 1014 #endif 1015 } 1016 1017 1018 //------------------register_new_node_with_optimizer--------------------------- 1019 // Register a new node with the optimizer. Update the types array, the def-use 1020 // info. Put on worklist. 1021 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) { 1022 set_type_bottom(n); 1023 _worklist.push(n); 1024 if (orig != NULL) C->copy_node_notes_to(n, orig); 1025 return n; 1026 } 1027 1028 //------------------------------transform-------------------------------------- 1029 // Non-recursive: idealize Node 'n' with respect to its inputs and its value 1030 Node *PhaseIterGVN::transform( Node *n ) { 1031 if (_delay_transform) { 1032 // Register the node but don't optimize for now 1033 register_new_node_with_optimizer(n); 1034 return n; 1035 } 1036 1037 // If brand new node, make space in type array, and give it a type. 1038 ensure_type_or_null(n); 1039 if (type_or_null(n) == NULL) { 1040 set_type_bottom(n); 1041 } 1042 1043 return transform_old(n); 1044 } 1045 1046 //------------------------------transform_old---------------------------------- 1047 Node *PhaseIterGVN::transform_old( Node *n ) { 1048 #ifndef PRODUCT 1049 debug_only(uint loop_count = 0;); 1050 set_transforms(); 1051 #endif 1052 // Remove 'n' from hash table in case it gets modified 1053 _table.hash_delete(n); 1054 if( VerifyIterativeGVN ) { 1055 assert( !_table.find_index(n->_idx), "found duplicate entry in table"); 1056 } 1057 1058 // Apply the Ideal call in a loop until it no longer applies 1059 Node *k = n; 1060 DEBUG_ONLY(dead_loop_check(k);) 1061 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);) 1062 Node *i = k->Ideal(this, /*can_reshape=*/true); 1063 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1064 #ifndef PRODUCT 1065 if( VerifyIterativeGVN ) 1066 verify_step(k); 1067 if( i && VerifyOpto ) { 1068 if( !allow_progress() ) { 1069 if (i->is_Add() && i->outcnt() == 1) { 1070 // Switched input to left side because this is the only use 1071 } else if( i->is_If() && (i->in(0) == NULL) ) { 1072 // This IF is dead because it is dominated by an equivalent IF When 1073 // dominating if changed, info is not propagated sparsely to 'this' 1074 // Propagating this info further will spuriously identify other 1075 // progress. 1076 return i; 1077 } else 1078 set_progress(); 1079 } else 1080 set_progress(); 1081 } 1082 #endif 1083 1084 while( i ) { 1085 #ifndef PRODUCT 1086 debug_only( if( loop_count >= K ) i->dump(4); ) 1087 assert(loop_count < K, "infinite loop in PhaseIterGVN::transform"); 1088 debug_only( loop_count++; ) 1089 #endif 1090 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes"); 1091 // Made a change; put users of original Node on worklist 1092 add_users_to_worklist( k ); 1093 // Replacing root of transform tree? 1094 if( k != i ) { 1095 // Make users of old Node now use new. 1096 subsume_node( k, i ); 1097 k = i; 1098 } 1099 DEBUG_ONLY(dead_loop_check(k);) 1100 // Try idealizing again 1101 DEBUG_ONLY(is_new = (k->outcnt() == 0);) 1102 i = k->Ideal(this, /*can_reshape=*/true); 1103 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1104 #ifndef PRODUCT 1105 if( VerifyIterativeGVN ) 1106 verify_step(k); 1107 if( i && VerifyOpto ) set_progress(); 1108 #endif 1109 } 1110 1111 // If brand new node, make space in type array. 1112 ensure_type_or_null(k); 1113 1114 // See what kind of values 'k' takes on at runtime 1115 const Type *t = k->Value(this); 1116 assert(t != NULL, "value sanity"); 1117 1118 // Since I just called 'Value' to compute the set of run-time values 1119 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 1120 // cache Value. Later requests for the local phase->type of this Node can 1121 // use the cached Value instead of suffering with 'bottom_type'. 1122 if (t != type_or_null(k)) { 1123 NOT_PRODUCT( set_progress(); ) 1124 NOT_PRODUCT( inc_new_values();) 1125 set_type(k, t); 1126 // If k is a TypeNode, capture any more-precise type permanently into Node 1127 k->raise_bottom_type(t); 1128 // Move users of node to worklist 1129 add_users_to_worklist( k ); 1130 } 1131 1132 // If 'k' computes a constant, replace it with a constant 1133 if( t->singleton() && !k->is_Con() ) { 1134 NOT_PRODUCT( set_progress(); ) 1135 Node *con = makecon(t); // Make a constant 1136 add_users_to_worklist( k ); 1137 subsume_node( k, con ); // Everybody using k now uses con 1138 return con; 1139 } 1140 1141 // Now check for Identities 1142 i = k->Identity(this); // Look for a nearby replacement 1143 if( i != k ) { // Found? Return replacement! 1144 NOT_PRODUCT( set_progress(); ) 1145 add_users_to_worklist( k ); 1146 subsume_node( k, i ); // Everybody using k now uses i 1147 return i; 1148 } 1149 1150 // Global Value Numbering 1151 i = hash_find_insert(k); // Check for pre-existing node 1152 if( i && (i != k) ) { 1153 // Return the pre-existing node if it isn't dead 1154 NOT_PRODUCT( set_progress(); ) 1155 add_users_to_worklist( k ); 1156 subsume_node( k, i ); // Everybody using k now uses i 1157 return i; 1158 } 1159 1160 // Return Idealized original 1161 return k; 1162 } 1163 1164 //---------------------------------saturate------------------------------------ 1165 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type, 1166 const Type* limit_type) const { 1167 return new_type->narrow(old_type); 1168 } 1169 1170 //------------------------------remove_globally_dead_node---------------------- 1171 // Kill a globally dead Node. All uses are also globally dead and are 1172 // aggressively trimmed. 1173 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) { 1174 enum DeleteProgress { 1175 PROCESS_INPUTS, 1176 PROCESS_OUTPUTS 1177 }; 1178 assert(_stack.is_empty(), "not empty"); 1179 _stack.push(dead, PROCESS_INPUTS); 1180 1181 while (_stack.is_nonempty()) { 1182 dead = _stack.node(); 1183 uint progress_state = _stack.index(); 1184 assert(dead != C->root(), "killing root, eh?"); 1185 assert(!dead->is_top(), "add check for top when pushing"); 1186 NOT_PRODUCT( set_progress(); ) 1187 if (progress_state == PROCESS_INPUTS) { 1188 // After following inputs, continue to outputs 1189 _stack.set_index(PROCESS_OUTPUTS); 1190 if (!dead->is_Con()) { // Don't kill cons but uses 1191 bool recurse = false; 1192 // Remove from hash table 1193 _table.hash_delete( dead ); 1194 // Smash all inputs to 'dead', isolating him completely 1195 for (uint i = 0; i < dead->req(); i++) { 1196 Node *in = dead->in(i); 1197 if (in != NULL && in != C->top()) { // Points to something? 1198 int nrep = dead->replace_edge(in, NULL); // Kill edges 1199 assert((nrep > 0), "sanity"); 1200 if (in->outcnt() == 0) { // Made input go dead? 1201 _stack.push(in, PROCESS_INPUTS); // Recursively remove 1202 recurse = true; 1203 } else if (in->outcnt() == 1 && 1204 in->has_special_unique_user()) { 1205 _worklist.push(in->unique_out()); 1206 } else if (in->outcnt() <= 2 && dead->is_Phi()) { 1207 if (in->Opcode() == Op_Region) { 1208 _worklist.push(in); 1209 } else if (in->is_Store()) { 1210 DUIterator_Fast imax, i = in->fast_outs(imax); 1211 _worklist.push(in->fast_out(i)); 1212 i++; 1213 if (in->outcnt() == 2) { 1214 _worklist.push(in->fast_out(i)); 1215 i++; 1216 } 1217 assert(!(i < imax), "sanity"); 1218 } 1219 } 1220 if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory && 1221 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) { 1222 // A Load that directly follows an InitializeNode is 1223 // going away. The Stores that follow are candidates 1224 // again to be captured by the InitializeNode. 1225 for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) { 1226 Node *n = in->fast_out(j); 1227 if (n->is_Store()) { 1228 _worklist.push(n); 1229 } 1230 } 1231 } 1232 } // if (in != NULL && in != C->top()) 1233 } // for (uint i = 0; i < dead->req(); i++) 1234 if (recurse) { 1235 continue; 1236 } 1237 } // if (!dead->is_Con()) 1238 } // if (progress_state == PROCESS_INPUTS) 1239 1240 // Aggressively kill globally dead uses 1241 // (Rather than pushing all the outs at once, we push one at a time, 1242 // plus the parent to resume later, because of the indefinite number 1243 // of edge deletions per loop trip.) 1244 if (dead->outcnt() > 0) { 1245 // Recursively remove output edges 1246 _stack.push(dead->raw_out(0), PROCESS_INPUTS); 1247 } else { 1248 // Finished disconnecting all input and output edges. 1249 _stack.pop(); 1250 // Remove dead node from iterative worklist 1251 _worklist.remove(dead); 1252 // Constant node that has no out-edges and has only one in-edge from 1253 // root is usually dead. However, sometimes reshaping walk makes 1254 // it reachable by adding use edges. So, we will NOT count Con nodes 1255 // as dead to be conservative about the dead node count at any 1256 // given time. 1257 if (!dead->is_Con()) { 1258 C->record_dead_node(dead->_idx); 1259 } 1260 if (dead->is_macro()) { 1261 C->remove_macro_node(dead); 1262 } 1263 if (dead->is_expensive()) { 1264 C->remove_expensive_node(dead); 1265 } 1266 } 1267 } // while (_stack.is_nonempty()) 1268 } 1269 1270 //------------------------------subsume_node----------------------------------- 1271 // Remove users from node 'old' and add them to node 'nn'. 1272 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) { 1273 assert( old != hash_find(old), "should already been removed" ); 1274 assert( old != C->top(), "cannot subsume top node"); 1275 // Copy debug or profile information to the new version: 1276 C->copy_node_notes_to(nn, old); 1277 // Move users of node 'old' to node 'nn' 1278 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) { 1279 Node* use = old->last_out(i); // for each use... 1280 // use might need re-hashing (but it won't if it's a new node) 1281 bool is_in_table = _table.hash_delete( use ); 1282 // Update use-def info as well 1283 // We remove all occurrences of old within use->in, 1284 // so as to avoid rehashing any node more than once. 1285 // The hash table probe swamps any outer loop overhead. 1286 uint num_edges = 0; 1287 for (uint jmax = use->len(), j = 0; j < jmax; j++) { 1288 if (use->in(j) == old) { 1289 use->set_req(j, nn); 1290 ++num_edges; 1291 } 1292 } 1293 // Insert into GVN hash table if unique 1294 // If a duplicate, 'use' will be cleaned up when pulled off worklist 1295 if( is_in_table ) { 1296 hash_find_insert(use); 1297 } 1298 i -= num_edges; // we deleted 1 or more copies of this edge 1299 } 1300 1301 // Smash all inputs to 'old', isolating him completely 1302 Node *temp = new (C) Node(1); 1303 temp->init_req(0,nn); // Add a use to nn to prevent him from dying 1304 remove_dead_node( old ); 1305 temp->del_req(0); // Yank bogus edge 1306 #ifndef PRODUCT 1307 if( VerifyIterativeGVN ) { 1308 for ( int i = 0; i < _verify_window_size; i++ ) { 1309 if ( _verify_window[i] == old ) 1310 _verify_window[i] = nn; 1311 } 1312 } 1313 #endif 1314 _worklist.remove(temp); // this can be necessary 1315 temp->destruct(); // reuse the _idx of this little guy 1316 } 1317 1318 //------------------------------add_users_to_worklist-------------------------- 1319 void PhaseIterGVN::add_users_to_worklist0( Node *n ) { 1320 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1321 _worklist.push(n->fast_out(i)); // Push on worklist 1322 } 1323 } 1324 1325 void PhaseIterGVN::add_users_to_worklist( Node *n ) { 1326 add_users_to_worklist0(n); 1327 1328 // Move users of node to worklist 1329 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1330 Node* use = n->fast_out(i); // Get use 1331 1332 if( use->is_Multi() || // Multi-definer? Push projs on worklist 1333 use->is_Store() ) // Enable store/load same address 1334 add_users_to_worklist0(use); 1335 1336 // If we changed the receiver type to a call, we need to revisit 1337 // the Catch following the call. It's looking for a non-NULL 1338 // receiver to know when to enable the regular fall-through path 1339 // in addition to the NullPtrException path. 1340 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) { 1341 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control); 1342 if (p != NULL) { 1343 add_users_to_worklist0(p); 1344 } 1345 } 1346 1347 uint use_op = use->Opcode(); 1348 if(use->is_Cmp()) { // Enable CMP/BOOL optimization 1349 add_users_to_worklist(use); // Put Bool on worklist 1350 if (use->outcnt() > 0) { 1351 Node* bol = use->raw_out(0); 1352 if (bol->outcnt() > 0) { 1353 Node* iff = bol->raw_out(0); 1354 if (use_op == Op_CmpI && 1355 iff->is_CountedLoopEnd()) { 1356 CountedLoopEndNode* cle = iff->as_CountedLoopEnd(); 1357 if (cle->limit() == n && cle->phi() != NULL) { 1358 // If an opaque node feeds into the limit condition of a 1359 // CountedLoop, we need to process the Phi node for the 1360 // induction variable when the opaque node is removed: 1361 // the range of values taken by the Phi is now known and 1362 // so its type is also known. 1363 _worklist.push(cle->phi()); 1364 } 1365 } else if (iff->outcnt() == 2) { 1366 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the 1367 // phi merging either 0 or 1 onto the worklist 1368 Node* ifproj0 = iff->raw_out(0); 1369 Node* ifproj1 = iff->raw_out(1); 1370 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) { 1371 Node* region0 = ifproj0->raw_out(0); 1372 Node* region1 = ifproj1->raw_out(0); 1373 if( region0 == region1 ) 1374 add_users_to_worklist0(region0); 1375 } 1376 } 1377 } 1378 } 1379 if (use_op == Op_CmpI) { 1380 Node* in1 = use->in(1); 1381 for (uint i = 0; i < in1->outcnt(); i++) { 1382 if (in1->raw_out(i)->Opcode() == Op_CastII) { 1383 Node* castii = in1->raw_out(i); 1384 if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) { 1385 Node* ifnode = castii->in(0)->in(0); 1386 if (ifnode->in(1) != NULL && ifnode->in(1)->is_Bool() && ifnode->in(1)->in(1) == use) { 1387 // Reprocess a CastII node that may depend on an 1388 // opaque node value when the opaque node is 1389 // removed. In case it carries a dependency we can do 1390 // a better job of computing its type. 1391 _worklist.push(castii); 1392 } 1393 } 1394 } 1395 } 1396 } 1397 } 1398 1399 // If changed Cast input, check Phi users for simple cycles 1400 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) { 1401 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1402 Node* u = use->fast_out(i2); 1403 if (u->is_Phi()) 1404 _worklist.push(u); 1405 } 1406 } 1407 // If changed LShift inputs, check RShift users for useless sign-ext 1408 if( use_op == Op_LShiftI ) { 1409 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1410 Node* u = use->fast_out(i2); 1411 if (u->Opcode() == Op_RShiftI) 1412 _worklist.push(u); 1413 } 1414 } 1415 // If changed AddI/SubI inputs, check CmpU for range check optimization. 1416 if (use_op == Op_AddI || use_op == Op_SubI) { 1417 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1418 Node* u = use->fast_out(i2); 1419 if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) { 1420 _worklist.push(u); 1421 } 1422 } 1423 } 1424 // If changed AddP inputs, check Stores for loop invariant 1425 if( use_op == Op_AddP ) { 1426 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1427 Node* u = use->fast_out(i2); 1428 if (u->is_Mem()) 1429 _worklist.push(u); 1430 } 1431 } 1432 // If changed initialization activity, check dependent Stores 1433 if (use_op == Op_Allocate || use_op == Op_AllocateArray) { 1434 InitializeNode* init = use->as_Allocate()->initialization(); 1435 if (init != NULL) { 1436 Node* imem = init->proj_out(TypeFunc::Memory); 1437 if (imem != NULL) add_users_to_worklist0(imem); 1438 } 1439 } 1440 if (use_op == Op_Initialize) { 1441 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory); 1442 if (imem != NULL) add_users_to_worklist0(imem); 1443 } 1444 } 1445 } 1446 1447 /** 1448 * Remove the speculative part of all types that we know of 1449 */ 1450 void PhaseIterGVN::remove_speculative_types() { 1451 assert(UseTypeSpeculation, "speculation is off"); 1452 for (uint i = 0; i < _types.Size(); i++) { 1453 const Type* t = _types.fast_lookup(i); 1454 if (t != NULL) { 1455 _types.map(i, t->remove_speculative()); 1456 } 1457 } 1458 _table.check_no_speculative_types(); 1459 } 1460 1461 //============================================================================= 1462 #ifndef PRODUCT 1463 uint PhaseCCP::_total_invokes = 0; 1464 uint PhaseCCP::_total_constants = 0; 1465 #endif 1466 //------------------------------PhaseCCP--------------------------------------- 1467 // Conditional Constant Propagation, ala Wegman & Zadeck 1468 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) { 1469 NOT_PRODUCT( clear_constants(); ) 1470 assert( _worklist.size() == 0, "" ); 1471 // Clear out _nodes from IterGVN. Must be clear to transform call. 1472 _nodes.clear(); // Clear out from IterGVN 1473 analyze(); 1474 } 1475 1476 #ifndef PRODUCT 1477 //------------------------------~PhaseCCP-------------------------------------- 1478 PhaseCCP::~PhaseCCP() { 1479 inc_invokes(); 1480 _total_constants += count_constants(); 1481 } 1482 #endif 1483 1484 1485 #ifdef ASSERT 1486 static bool ccp_type_widens(const Type* t, const Type* t0) { 1487 assert(t->meet(t0) == t, "Not monotonic"); 1488 switch (t->base() == t0->base() ? t->base() : Type::Top) { 1489 case Type::Int: 1490 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases"); 1491 break; 1492 case Type::Long: 1493 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases"); 1494 break; 1495 } 1496 return true; 1497 } 1498 #endif //ASSERT 1499 1500 //------------------------------analyze---------------------------------------- 1501 void PhaseCCP::analyze() { 1502 // Initialize all types to TOP, optimistic analysis 1503 for (int i = C->unique() - 1; i >= 0; i--) { 1504 _types.map(i,Type::TOP); 1505 } 1506 1507 // Push root onto worklist 1508 Unique_Node_List worklist; 1509 worklist.push(C->root()); 1510 1511 // Pull from worklist; compute new value; push changes out. 1512 // This loop is the meat of CCP. 1513 while( worklist.size() ) { 1514 Node *n = worklist.pop(); 1515 const Type *t = n->Value(this); 1516 if (t != type(n)) { 1517 assert(ccp_type_widens(t, type(n)), "ccp type must widen"); 1518 #ifndef PRODUCT 1519 if( TracePhaseCCP ) { 1520 t->dump(); 1521 do { tty->print("\t"); } while (tty->position() < 16); 1522 n->dump(); 1523 } 1524 #endif 1525 set_type(n, t); 1526 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1527 Node* m = n->fast_out(i); // Get user 1528 if (m->is_Region()) { // New path to Region? Must recheck Phis too 1529 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1530 Node* p = m->fast_out(i2); // Propagate changes to uses 1531 if (p->bottom_type() != type(p)) { // If not already bottomed out 1532 worklist.push(p); // Propagate change to user 1533 } 1534 } 1535 } 1536 // If we changed the receiver type to a call, we need to revisit 1537 // the Catch following the call. It's looking for a non-NULL 1538 // receiver to know when to enable the regular fall-through path 1539 // in addition to the NullPtrException path 1540 if (m->is_Call()) { 1541 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1542 Node* p = m->fast_out(i2); // Propagate changes to uses 1543 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) { 1544 worklist.push(p->unique_out()); 1545 } 1546 } 1547 } 1548 if (m->bottom_type() != type(m)) { // If not already bottomed out 1549 worklist.push(m); // Propagate change to user 1550 } 1551 1552 // CmpU nodes can get their type information from two nodes up in the 1553 // graph (instead of from the nodes immediately above). Make sure they 1554 // are added to the worklist if nodes they depend on are updated, since 1555 // they could be missed and get wrong types otherwise. 1556 uint m_op = m->Opcode(); 1557 if (m_op == Op_AddI || m_op == Op_SubI) { 1558 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1559 Node* p = m->fast_out(i2); // Propagate changes to uses 1560 if (p->Opcode() == Op_CmpU) { 1561 // Got a CmpU which might need the new type information from node n. 1562 if(p->bottom_type() != type(p)) { // If not already bottomed out 1563 worklist.push(p); // Propagate change to user 1564 } 1565 } 1566 } 1567 } 1568 } 1569 } 1570 } 1571 } 1572 1573 //------------------------------do_transform----------------------------------- 1574 // Top level driver for the recursive transformer 1575 void PhaseCCP::do_transform() { 1576 // Correct leaves of new-space Nodes; they point to old-space. 1577 C->set_root( transform(C->root())->as_Root() ); 1578 assert( C->top(), "missing TOP node" ); 1579 assert( C->root(), "missing root" ); 1580 } 1581 1582 //------------------------------transform-------------------------------------- 1583 // Given a Node in old-space, clone him into new-space. 1584 // Convert any of his old-space children into new-space children. 1585 Node *PhaseCCP::transform( Node *n ) { 1586 Node *new_node = _nodes[n->_idx]; // Check for transformed node 1587 if( new_node != NULL ) 1588 return new_node; // Been there, done that, return old answer 1589 new_node = transform_once(n); // Check for constant 1590 _nodes.map( n->_idx, new_node ); // Flag as having been cloned 1591 1592 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc 1593 GrowableArray <Node *> trstack(C->live_nodes() >> 1); 1594 1595 trstack.push(new_node); // Process children of cloned node 1596 while ( trstack.is_nonempty() ) { 1597 Node *clone = trstack.pop(); 1598 uint cnt = clone->req(); 1599 for( uint i = 0; i < cnt; i++ ) { // For all inputs do 1600 Node *input = clone->in(i); 1601 if( input != NULL ) { // Ignore NULLs 1602 Node *new_input = _nodes[input->_idx]; // Check for cloned input node 1603 if( new_input == NULL ) { 1604 new_input = transform_once(input); // Check for constant 1605 _nodes.map( input->_idx, new_input );// Flag as having been cloned 1606 trstack.push(new_input); 1607 } 1608 assert( new_input == clone->in(i), "insanity check"); 1609 } 1610 } 1611 } 1612 return new_node; 1613 } 1614 1615 1616 //------------------------------transform_once--------------------------------- 1617 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant. 1618 Node *PhaseCCP::transform_once( Node *n ) { 1619 const Type *t = type(n); 1620 // Constant? Use constant Node instead 1621 if( t->singleton() ) { 1622 Node *nn = n; // Default is to return the original constant 1623 if( t == Type::TOP ) { 1624 // cache my top node on the Compile instance 1625 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) { 1626 C->set_cached_top_node( ConNode::make(C, Type::TOP) ); 1627 set_type(C->top(), Type::TOP); 1628 } 1629 nn = C->top(); 1630 } 1631 if( !n->is_Con() ) { 1632 if( t != Type::TOP ) { 1633 nn = makecon(t); // ConNode::make(t); 1634 NOT_PRODUCT( inc_constants(); ) 1635 } else if( n->is_Region() ) { // Unreachable region 1636 // Note: nn == C->top() 1637 n->set_req(0, NULL); // Cut selfreference 1638 // Eagerly remove dead phis to avoid phis copies creation. 1639 for (DUIterator i = n->outs(); n->has_out(i); i++) { 1640 Node* m = n->out(i); 1641 if( m->is_Phi() ) { 1642 assert(type(m) == Type::TOP, "Unreachable region should not have live phis."); 1643 replace_node(m, nn); 1644 --i; // deleted this phi; rescan starting with next position 1645 } 1646 } 1647 } 1648 replace_node(n,nn); // Update DefUse edges for new constant 1649 } 1650 return nn; 1651 } 1652 1653 // If x is a TypeNode, capture any more-precise type permanently into Node 1654 if (t != n->bottom_type()) { 1655 hash_delete(n); // changing bottom type may force a rehash 1656 n->raise_bottom_type(t); 1657 _worklist.push(n); // n re-enters the hash table via the worklist 1658 } 1659 1660 // Idealize graph using DU info. Must clone() into new-space. 1661 // DU info is generally used to show profitability, progress or safety 1662 // (but generally not needed for correctness). 1663 Node *nn = n->Ideal_DU_postCCP(this); 1664 1665 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks 1666 switch( n->Opcode() ) { 1667 case Op_FastLock: // Revisit FastLocks for lock coarsening 1668 case Op_If: 1669 case Op_CountedLoopEnd: 1670 case Op_Region: 1671 case Op_Loop: 1672 case Op_CountedLoop: 1673 case Op_Conv2B: 1674 case Op_Opaque1: 1675 case Op_Opaque2: 1676 _worklist.push(n); 1677 break; 1678 default: 1679 break; 1680 } 1681 if( nn ) { 1682 _worklist.push(n); 1683 // Put users of 'n' onto worklist for second igvn transform 1684 add_users_to_worklist(n); 1685 return nn; 1686 } 1687 1688 return n; 1689 } 1690 1691 //---------------------------------saturate------------------------------------ 1692 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type, 1693 const Type* limit_type) const { 1694 const Type* wide_type = new_type->widen(old_type, limit_type); 1695 if (wide_type != new_type) { // did we widen? 1696 // If so, we may have widened beyond the limit type. Clip it back down. 1697 new_type = wide_type->filter(limit_type); 1698 } 1699 return new_type; 1700 } 1701 1702 //------------------------------print_statistics------------------------------- 1703 #ifndef PRODUCT 1704 void PhaseCCP::print_statistics() { 1705 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants); 1706 } 1707 #endif 1708 1709 1710 //============================================================================= 1711 #ifndef PRODUCT 1712 uint PhasePeephole::_total_peepholes = 0; 1713 #endif 1714 //------------------------------PhasePeephole---------------------------------- 1715 // Conditional Constant Propagation, ala Wegman & Zadeck 1716 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ) 1717 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) { 1718 NOT_PRODUCT( clear_peepholes(); ) 1719 } 1720 1721 #ifndef PRODUCT 1722 //------------------------------~PhasePeephole--------------------------------- 1723 PhasePeephole::~PhasePeephole() { 1724 _total_peepholes += count_peepholes(); 1725 } 1726 #endif 1727 1728 //------------------------------transform-------------------------------------- 1729 Node *PhasePeephole::transform( Node *n ) { 1730 ShouldNotCallThis(); 1731 return NULL; 1732 } 1733 1734 //------------------------------do_transform----------------------------------- 1735 void PhasePeephole::do_transform() { 1736 bool method_name_not_printed = true; 1737 1738 // Examine each basic block 1739 for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) { 1740 Block* block = _cfg.get_block(block_number); 1741 bool block_not_printed = true; 1742 1743 // and each instruction within a block 1744 uint end_index = block->number_of_nodes(); 1745 // block->end_idx() not valid after PhaseRegAlloc 1746 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) { 1747 Node *n = block->get_node(instruction_index); 1748 if( n->is_Mach() ) { 1749 MachNode *m = n->as_Mach(); 1750 int deleted_count = 0; 1751 // check for peephole opportunities 1752 MachNode *m2 = m->peephole( block, instruction_index, _regalloc, deleted_count, C ); 1753 if( m2 != NULL ) { 1754 #ifndef PRODUCT 1755 if( PrintOptoPeephole ) { 1756 // Print method, first time only 1757 if( C->method() && method_name_not_printed ) { 1758 C->method()->print_short_name(); tty->cr(); 1759 method_name_not_printed = false; 1760 } 1761 // Print this block 1762 if( Verbose && block_not_printed) { 1763 tty->print_cr("in block"); 1764 block->dump(); 1765 block_not_printed = false; 1766 } 1767 // Print instructions being deleted 1768 for( int i = (deleted_count - 1); i >= 0; --i ) { 1769 block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr(); 1770 } 1771 tty->print_cr("replaced with"); 1772 // Print new instruction 1773 m2->format(_regalloc); 1774 tty->print("\n\n"); 1775 } 1776 #endif 1777 // Remove old nodes from basic block and update instruction_index 1778 // (old nodes still exist and may have edges pointing to them 1779 // as register allocation info is stored in the allocator using 1780 // the node index to live range mappings.) 1781 uint safe_instruction_index = (instruction_index - deleted_count); 1782 for( ; (instruction_index > safe_instruction_index); --instruction_index ) { 1783 block->remove_node( instruction_index ); 1784 } 1785 // install new node after safe_instruction_index 1786 block->insert_node(m2, safe_instruction_index + 1); 1787 end_index = block->number_of_nodes() - 1; // Recompute new block size 1788 NOT_PRODUCT( inc_peepholes(); ) 1789 } 1790 } 1791 } 1792 } 1793 } 1794 1795 //------------------------------print_statistics------------------------------- 1796 #ifndef PRODUCT 1797 void PhasePeephole::print_statistics() { 1798 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes); 1799 } 1800 #endif 1801 1802 1803 //============================================================================= 1804 //------------------------------set_req_X-------------------------------------- 1805 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) { 1806 assert( is_not_dead(n), "can not use dead node"); 1807 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" ); 1808 Node *old = in(i); 1809 set_req(i, n); 1810 1811 // old goes dead? 1812 if( old ) { 1813 switch (old->outcnt()) { 1814 case 0: 1815 // Put into the worklist to kill later. We do not kill it now because the 1816 // recursive kill will delete the current node (this) if dead-loop exists 1817 if (!old->is_top()) 1818 igvn->_worklist.push( old ); 1819 break; 1820 case 1: 1821 if( old->is_Store() || old->has_special_unique_user() ) 1822 igvn->add_users_to_worklist( old ); 1823 break; 1824 case 2: 1825 if( old->is_Store() ) 1826 igvn->add_users_to_worklist( old ); 1827 if( old->Opcode() == Op_Region ) 1828 igvn->_worklist.push(old); 1829 break; 1830 case 3: 1831 if( old->Opcode() == Op_Region ) { 1832 igvn->_worklist.push(old); 1833 igvn->add_users_to_worklist( old ); 1834 } 1835 break; 1836 default: 1837 break; 1838 } 1839 } 1840 1841 } 1842 1843 //-------------------------------replace_by----------------------------------- 1844 // Using def-use info, replace one node for another. Follow the def-use info 1845 // to all users of the OLD node. Then make all uses point to the NEW node. 1846 void Node::replace_by(Node *new_node) { 1847 assert(!is_top(), "top node has no DU info"); 1848 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) { 1849 Node* use = last_out(i); 1850 uint uses_found = 0; 1851 for (uint j = 0; j < use->len(); j++) { 1852 if (use->in(j) == this) { 1853 if (j < use->req()) 1854 use->set_req(j, new_node); 1855 else use->set_prec(j, new_node); 1856 uses_found++; 1857 } 1858 } 1859 i -= uses_found; // we deleted 1 or more copies of this edge 1860 } 1861 } 1862 1863 //============================================================================= 1864 //----------------------------------------------------------------------------- 1865 void Type_Array::grow( uint i ) { 1866 if( !_max ) { 1867 _max = 1; 1868 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) ); 1869 _types[0] = NULL; 1870 } 1871 uint old = _max; 1872 while( i >= _max ) _max <<= 1; // Double to fit 1873 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*)); 1874 memset( &_types[old], 0, (_max-old)*sizeof(Type*) ); 1875 } 1876 1877 //------------------------------dump------------------------------------------- 1878 #ifndef PRODUCT 1879 void Type_Array::dump() const { 1880 uint max = Size(); 1881 for( uint i = 0; i < max; i++ ) { 1882 if( _types[i] != NULL ) { 1883 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr(); 1884 } 1885 } 1886 } 1887 #endif