1 /* 2 * Copyright (c) 1997, 2017, 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, PhaseNumber phase_num) : Phase(phase_num), 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 } 423 424 //============================================================================= 425 //------------------------------PhaseRenumberLive------------------------------ 426 // First, remove useless nodes (equivalent to identifying live nodes). 427 // Then, renumber live nodes. 428 // 429 // The set of live nodes is returned by PhaseRemoveUseless in the _useful structure. 430 // If the number of live nodes is 'x' (where 'x' == _useful.size()), then the 431 // PhaseRenumberLive updates the node ID of each node (the _idx field) with a unique 432 // value in the range [0, x). 433 // 434 // At the end of the PhaseRenumberLive phase, the compiler's count of unique nodes is 435 // updated to 'x' and the list of dead nodes is reset (as there are no dead nodes). 436 // 437 // The PhaseRenumberLive phase updates two data structures with the new node IDs. 438 // (1) The worklist is used by the PhaseIterGVN phase to identify nodes that must be 439 // processed. A new worklist (with the updated node IDs) is returned in 'new_worklist'. 440 // (2) Type information (the field PhaseGVN::_types) maps type information to each 441 // node ID. The mapping is updated to use the new node IDs as well. Updated type 442 // information is returned in PhaseGVN::_types. 443 // 444 // The PhaseRenumberLive phase does not preserve the order of elements in the worklist. 445 // 446 // Other data structures used by the compiler are not updated. The hash table for value 447 // numbering (the field PhaseGVN::_table) is not updated because computing the hash 448 // values is not based on node IDs. The field PhaseGVN::_nodes is not updated either 449 // because it is empty wherever PhaseRenumberLive is used. 450 PhaseRenumberLive::PhaseRenumberLive(PhaseGVN* gvn, 451 Unique_Node_List* worklist, Unique_Node_List* new_worklist, 452 PhaseNumber phase_num) : 453 PhaseRemoveUseless(gvn, worklist, Remove_Useless_And_Renumber_Live) { 454 455 assert(RenumberLiveNodes, "RenumberLiveNodes must be set to true for node renumbering to take place"); 456 assert(C->live_nodes() == _useful.size(), "the number of live nodes must match the number of useful nodes"); 457 assert(gvn->nodes_size() == 0, "GVN must not contain any nodes at this point"); 458 459 uint old_unique_count = C->unique(); 460 uint live_node_count = C->live_nodes(); 461 uint worklist_size = worklist->size(); 462 463 // Storage for the updated type information. 464 Type_Array new_type_array(C->comp_arena()); 465 466 // Iterate over the set of live nodes. 467 uint current_idx = 0; // The current new node ID. Incremented after every assignment. 468 for (uint i = 0; i < _useful.size(); i++) { 469 Node* n = _useful.at(i); 470 // Sanity check that fails if we ever decide to execute this phase after EA 471 assert(!n->is_Phi() || n->as_Phi()->inst_mem_id() == -1, "should not be linked to data Phi"); 472 const Type* type = gvn->type_or_null(n); 473 new_type_array.map(current_idx, type); 474 475 bool in_worklist = false; 476 if (worklist->member(n)) { 477 in_worklist = true; 478 } 479 480 n->set_idx(current_idx); // Update node ID. 481 482 if (in_worklist) { 483 new_worklist->push(n); 484 } 485 486 current_idx++; 487 } 488 489 assert(worklist_size == new_worklist->size(), "the new worklist must have the same size as the original worklist"); 490 assert(live_node_count == current_idx, "all live nodes must be processed"); 491 492 // Replace the compiler's type information with the updated type information. 493 gvn->replace_types(new_type_array); 494 495 // Update the unique node count of the compilation to the number of currently live nodes. 496 C->set_unique(live_node_count); 497 498 // Set the dead node count to 0 and reset dead node list. 499 C->reset_dead_node_list(); 500 } 501 502 503 //============================================================================= 504 //------------------------------PhaseTransform--------------------------------- 505 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum), 506 _arena(Thread::current()->resource_area()), 507 _nodes(_arena), 508 _types(_arena) 509 { 510 init_con_caches(); 511 #ifndef PRODUCT 512 clear_progress(); 513 clear_transforms(); 514 set_allow_progress(true); 515 #endif 516 // Force allocation for currently existing nodes 517 _types.map(C->unique(), NULL); 518 } 519 520 //------------------------------PhaseTransform--------------------------------- 521 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum), 522 _arena(arena), 523 _nodes(arena), 524 _types(arena) 525 { 526 init_con_caches(); 527 #ifndef PRODUCT 528 clear_progress(); 529 clear_transforms(); 530 set_allow_progress(true); 531 #endif 532 // Force allocation for currently existing nodes 533 _types.map(C->unique(), NULL); 534 } 535 536 //------------------------------PhaseTransform--------------------------------- 537 // Initialize with previously generated type information 538 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum), 539 _arena(pt->_arena), 540 _nodes(pt->_nodes), 541 _types(pt->_types) 542 { 543 init_con_caches(); 544 #ifndef PRODUCT 545 clear_progress(); 546 clear_transforms(); 547 set_allow_progress(true); 548 #endif 549 } 550 551 void PhaseTransform::init_con_caches() { 552 memset(_icons,0,sizeof(_icons)); 553 memset(_lcons,0,sizeof(_lcons)); 554 memset(_zcons,0,sizeof(_zcons)); 555 } 556 557 558 //--------------------------------find_int_type-------------------------------- 559 const TypeInt* PhaseTransform::find_int_type(Node* n) { 560 if (n == NULL) return NULL; 561 // Call type_or_null(n) to determine node's type since we might be in 562 // parse phase and call n->Value() may return wrong type. 563 // (For example, a phi node at the beginning of loop parsing is not ready.) 564 const Type* t = type_or_null(n); 565 if (t == NULL) return NULL; 566 return t->isa_int(); 567 } 568 569 570 //-------------------------------find_long_type-------------------------------- 571 const TypeLong* PhaseTransform::find_long_type(Node* n) { 572 if (n == NULL) return NULL; 573 // (See comment above on type_or_null.) 574 const Type* t = type_or_null(n); 575 if (t == NULL) return NULL; 576 return t->isa_long(); 577 } 578 579 580 #ifndef PRODUCT 581 void PhaseTransform::dump_old2new_map() const { 582 _nodes.dump(); 583 } 584 585 void PhaseTransform::dump_new( uint nidx ) const { 586 for( uint i=0; i<_nodes.Size(); i++ ) 587 if( _nodes[i] && _nodes[i]->_idx == nidx ) { 588 _nodes[i]->dump(); 589 tty->cr(); 590 tty->print_cr("Old index= %d",i); 591 return; 592 } 593 tty->print_cr("Node %d not found in the new indices", nidx); 594 } 595 596 //------------------------------dump_types------------------------------------- 597 void PhaseTransform::dump_types( ) const { 598 _types.dump(); 599 } 600 601 //------------------------------dump_nodes_and_types--------------------------- 602 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) { 603 VectorSet visited(Thread::current()->resource_area()); 604 dump_nodes_and_types_recur( root, depth, only_ctrl, visited ); 605 } 606 607 //------------------------------dump_nodes_and_types_recur--------------------- 608 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) { 609 if( !n ) return; 610 if( depth == 0 ) return; 611 if( visited.test_set(n->_idx) ) return; 612 for( uint i=0; i<n->len(); i++ ) { 613 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue; 614 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited ); 615 } 616 n->dump(); 617 if (type_or_null(n) != NULL) { 618 tty->print(" "); type(n)->dump(); tty->cr(); 619 } 620 } 621 622 #endif 623 624 625 //============================================================================= 626 //------------------------------PhaseValues------------------------------------ 627 // Set minimum table size to "255" 628 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) { 629 NOT_PRODUCT( clear_new_values(); ) 630 } 631 632 //------------------------------PhaseValues------------------------------------ 633 // Set minimum table size to "255" 634 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ), 635 _table(&ptv->_table) { 636 NOT_PRODUCT( clear_new_values(); ) 637 } 638 639 //------------------------------PhaseValues------------------------------------ 640 // Used by +VerifyOpto. Clear out hash table but copy _types array. 641 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ), 642 _table(ptv->arena(),ptv->_table.size()) { 643 NOT_PRODUCT( clear_new_values(); ) 644 } 645 646 //------------------------------~PhaseValues----------------------------------- 647 #ifndef PRODUCT 648 PhaseValues::~PhaseValues() { 649 _table.dump(); 650 651 // Statistics for value progress and efficiency 652 if( PrintCompilation && Verbose && WizardMode ) { 653 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)", 654 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values()); 655 if( made_transforms() != 0 ) { 656 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() ); 657 } else { 658 tty->cr(); 659 } 660 } 661 } 662 #endif 663 664 //------------------------------makecon---------------------------------------- 665 ConNode* PhaseTransform::makecon(const Type *t) { 666 assert(t->singleton(), "must be a constant"); 667 assert(!t->empty() || t == Type::TOP, "must not be vacuous range"); 668 switch (t->base()) { // fast paths 669 case Type::Half: 670 case Type::Top: return (ConNode*) C->top(); 671 case Type::Int: return intcon( t->is_int()->get_con() ); 672 case Type::Long: return longcon( t->is_long()->get_con() ); 673 } 674 if (t->is_zero_type()) 675 return zerocon(t->basic_type()); 676 return uncached_makecon(t); 677 } 678 679 //--------------------------uncached_makecon----------------------------------- 680 // Make an idealized constant - one of ConINode, ConPNode, etc. 681 ConNode* PhaseValues::uncached_makecon(const Type *t) { 682 assert(t->singleton(), "must be a constant"); 683 ConNode* x = ConNode::make(C, t); 684 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering 685 if (k == NULL) { 686 set_type(x, t); // Missed, provide type mapping 687 GrowableArray<Node_Notes*>* nna = C->node_note_array(); 688 if (nna != NULL) { 689 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true); 690 loc->clear(); // do not put debug info on constants 691 } 692 } else { 693 x->destruct(); // Hit, destroy duplicate constant 694 x = k; // use existing constant 695 } 696 return x; 697 } 698 699 //------------------------------intcon----------------------------------------- 700 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))" 701 ConINode* PhaseTransform::intcon(int i) { 702 // Small integer? Check cache! Check that cached node is not dead 703 if (i >= _icon_min && i <= _icon_max) { 704 ConINode* icon = _icons[i-_icon_min]; 705 if (icon != NULL && icon->in(TypeFunc::Control) != NULL) 706 return icon; 707 } 708 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i)); 709 assert(icon->is_Con(), ""); 710 if (i >= _icon_min && i <= _icon_max) 711 _icons[i-_icon_min] = icon; // Cache small integers 712 return icon; 713 } 714 715 //------------------------------longcon---------------------------------------- 716 // Fast long constant. 717 ConLNode* PhaseTransform::longcon(jlong l) { 718 // Small integer? Check cache! Check that cached node is not dead 719 if (l >= _lcon_min && l <= _lcon_max) { 720 ConLNode* lcon = _lcons[l-_lcon_min]; 721 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL) 722 return lcon; 723 } 724 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l)); 725 assert(lcon->is_Con(), ""); 726 if (l >= _lcon_min && l <= _lcon_max) 727 _lcons[l-_lcon_min] = lcon; // Cache small integers 728 return lcon; 729 } 730 731 //------------------------------zerocon----------------------------------------- 732 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))" 733 ConNode* PhaseTransform::zerocon(BasicType bt) { 734 assert((uint)bt <= _zcon_max, "domain check"); 735 ConNode* zcon = _zcons[bt]; 736 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL) 737 return zcon; 738 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt)); 739 _zcons[bt] = zcon; 740 return zcon; 741 } 742 743 744 745 //============================================================================= 746 //------------------------------transform-------------------------------------- 747 // Return a node which computes the same function as this node, but in a 748 // faster or cheaper fashion. 749 Node *PhaseGVN::transform( Node *n ) { 750 return transform_no_reclaim(n); 751 } 752 753 //------------------------------transform-------------------------------------- 754 // Return a node which computes the same function as this node, but 755 // in a faster or cheaper fashion. 756 Node *PhaseGVN::transform_no_reclaim( Node *n ) { 757 NOT_PRODUCT( set_transforms(); ) 758 759 // Apply the Ideal call in a loop until it no longer applies 760 Node *k = n; 761 NOT_PRODUCT( uint loop_count = 0; ) 762 while( 1 ) { 763 Node *i = k->Ideal(this, /*can_reshape=*/false); 764 if( !i ) break; 765 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" ); 766 k = i; 767 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform"); 768 } 769 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } ) 770 771 772 // If brand new node, make space in type array. 773 ensure_type_or_null(k); 774 775 // Since I just called 'Value' to compute the set of run-time values 776 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 777 // cache Value. Later requests for the local phase->type of this Node can 778 // use the cached Value instead of suffering with 'bottom_type'. 779 const Type *t = k->Value(this); // Get runtime Value set 780 assert(t != NULL, "value sanity"); 781 if (type_or_null(k) != t) { 782 #ifndef PRODUCT 783 // Do not count initial visit to node as a transformation 784 if (type_or_null(k) == NULL) { 785 inc_new_values(); 786 set_progress(); 787 } 788 #endif 789 set_type(k, t); 790 // If k is a TypeNode, capture any more-precise type permanently into Node 791 k->raise_bottom_type(t); 792 } 793 794 if( t->singleton() && !k->is_Con() ) { 795 NOT_PRODUCT( set_progress(); ) 796 return makecon(t); // Turn into a constant 797 } 798 799 // Now check for Identities 800 Node *i = k->Identity(this); // Look for a nearby replacement 801 if( i != k ) { // Found? Return replacement! 802 NOT_PRODUCT( set_progress(); ) 803 return i; 804 } 805 806 // Global Value Numbering 807 i = hash_find_insert(k); // Insert if new 808 if( i && (i != k) ) { 809 // Return the pre-existing node 810 NOT_PRODUCT( set_progress(); ) 811 return i; 812 } 813 814 // Return Idealized original 815 return k; 816 } 817 818 #ifdef ASSERT 819 //------------------------------dead_loop_check-------------------------------- 820 // Check for a simple dead loop when a data node references itself directly 821 // or through an other data node excluding cons and phis. 822 void PhaseGVN::dead_loop_check( Node *n ) { 823 // Phi may reference itself in a loop 824 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) { 825 // Do 2 levels check and only data inputs. 826 bool no_dead_loop = true; 827 uint cnt = n->req(); 828 for (uint i = 1; i < cnt && no_dead_loop; i++) { 829 Node *in = n->in(i); 830 if (in == n) { 831 no_dead_loop = false; 832 } else if (in != NULL && !in->is_dead_loop_safe()) { 833 uint icnt = in->req(); 834 for (uint j = 1; j < icnt && no_dead_loop; j++) { 835 if (in->in(j) == n || in->in(j) == in) 836 no_dead_loop = false; 837 } 838 } 839 } 840 if (!no_dead_loop) n->dump(3); 841 assert(no_dead_loop, "dead loop detected"); 842 } 843 } 844 #endif 845 846 //============================================================================= 847 //------------------------------PhaseIterGVN----------------------------------- 848 // Initialize hash table to fresh and clean for +VerifyOpto 849 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ), 850 _stack(C->live_nodes() >> 1), 851 _delay_transform(false) { 852 } 853 854 //------------------------------PhaseIterGVN----------------------------------- 855 // Initialize with previous PhaseIterGVN info; used by PhaseCCP 856 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn), 857 _worklist( igvn->_worklist ), 858 _stack( igvn->_stack ), 859 _delay_transform(igvn->_delay_transform) 860 { 861 } 862 863 //------------------------------PhaseIterGVN----------------------------------- 864 // Initialize with previous PhaseGVN info from Parser 865 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn), 866 _worklist(*C->for_igvn()), 867 // TODO: Before incremental inlining it was allocated only once and it was fine. Now that 868 // the constructor is used in incremental inlining, this consumes too much memory: 869 // _stack(C->live_nodes() >> 1), 870 // So, as a band-aid, we replace this by: 871 _stack(C->comp_arena(), 32), 872 _delay_transform(false) 873 { 874 uint max; 875 876 // Dead nodes in the hash table inherited from GVN were not treated as 877 // roots during def-use info creation; hence they represent an invisible 878 // use. Clear them out. 879 max = _table.size(); 880 for( uint i = 0; i < max; ++i ) { 881 Node *n = _table.at(i); 882 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) { 883 if( n->is_top() ) continue; 884 assert( false, "Parse::remove_useless_nodes missed this node"); 885 hash_delete(n); 886 } 887 } 888 889 // Any Phis or Regions on the worklist probably had uses that could not 890 // make more progress because the uses were made while the Phis and Regions 891 // were in half-built states. Put all uses of Phis and Regions on worklist. 892 max = _worklist.size(); 893 for( uint j = 0; j < max; j++ ) { 894 Node *n = _worklist.at(j); 895 uint uop = n->Opcode(); 896 if( uop == Op_Phi || uop == Op_Region || 897 n->is_Type() || 898 n->is_Mem() ) 899 add_users_to_worklist(n); 900 } 901 } 902 903 904 #ifndef PRODUCT 905 void PhaseIterGVN::verify_step(Node* n) { 906 _verify_window[_verify_counter % _verify_window_size] = n; 907 ++_verify_counter; 908 ResourceMark rm; 909 ResourceArea *area = Thread::current()->resource_area(); 910 VectorSet old_space(area), new_space(area); 911 if (C->unique() < 1000 || 912 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) { 913 ++_verify_full_passes; 914 Node::verify_recur(C->root(), -1, old_space, new_space); 915 } 916 const int verify_depth = 4; 917 for ( int i = 0; i < _verify_window_size; i++ ) { 918 Node* n = _verify_window[i]; 919 if ( n == NULL ) continue; 920 if( n->in(0) == NodeSentinel ) { // xform_idom 921 _verify_window[i] = n->in(1); 922 --i; continue; 923 } 924 // Typical fanout is 1-2, so this call visits about 6 nodes. 925 Node::verify_recur(n, verify_depth, old_space, new_space); 926 } 927 } 928 #endif 929 930 931 //------------------------------init_worklist---------------------------------- 932 // Initialize worklist for each node. 933 void PhaseIterGVN::init_worklist( Node *n ) { 934 if( _worklist.member(n) ) return; 935 _worklist.push(n); 936 uint cnt = n->req(); 937 for( uint i =0 ; i < cnt; i++ ) { 938 Node *m = n->in(i); 939 if( m ) init_worklist(m); 940 } 941 } 942 943 //------------------------------optimize--------------------------------------- 944 void PhaseIterGVN::optimize() { 945 debug_only(uint num_processed = 0;); 946 #ifndef PRODUCT 947 { 948 _verify_counter = 0; 949 _verify_full_passes = 0; 950 for ( int i = 0; i < _verify_window_size; i++ ) { 951 _verify_window[i] = NULL; 952 } 953 } 954 #endif 955 956 #ifdef ASSERT 957 Node* prev = NULL; 958 uint rep_cnt = 0; 959 #endif 960 uint loop_count = 0; 961 962 // Pull from worklist; transform node; 963 // If node has changed: update edge info and put uses on worklist. 964 while( _worklist.size() ) { 965 if (C->check_node_count(NodeLimitFudgeFactor * 2, 966 "out of nodes optimizing method")) { 967 return; 968 } 969 Node *n = _worklist.pop(); 970 if (++loop_count >= K * C->live_nodes()) { 971 debug_only(n->dump(4);) 972 assert(false, "infinite loop in PhaseIterGVN::optimize"); 973 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize"); 974 return; 975 } 976 #ifdef ASSERT 977 if (n == prev) { 978 if (++rep_cnt > 3) { 979 n->dump(4); 980 assert(false, "loop in Ideal transformation"); 981 } 982 } else { 983 rep_cnt = 0; 984 } 985 prev = n; 986 #endif 987 if (TraceIterativeGVN && Verbose) { 988 tty->print(" Pop "); 989 NOT_PRODUCT( n->dump(); ) 990 debug_only(if( (num_processed++ % 100) == 0 ) _worklist.print_set();) 991 } 992 993 if (n->outcnt() != 0) { 994 995 #ifndef PRODUCT 996 uint wlsize = _worklist.size(); 997 const Type* oldtype = type_or_null(n); 998 #endif //PRODUCT 999 1000 Node *nn = transform_old(n); 1001 1002 #ifndef PRODUCT 1003 if (TraceIterativeGVN) { 1004 const Type* newtype = type_or_null(n); 1005 if (nn != n) { 1006 // print old node 1007 tty->print("< "); 1008 if (oldtype != newtype && oldtype != NULL) { 1009 oldtype->dump(); 1010 } 1011 do { tty->print("\t"); } while (tty->position() < 16); 1012 tty->print("<"); 1013 n->dump(); 1014 } 1015 if (oldtype != newtype || nn != n) { 1016 // print new node and/or new type 1017 if (oldtype == NULL) { 1018 tty->print("* "); 1019 } else if (nn != n) { 1020 tty->print("> "); 1021 } else { 1022 tty->print("= "); 1023 } 1024 if (newtype == NULL) { 1025 tty->print("null"); 1026 } else { 1027 newtype->dump(); 1028 } 1029 do { tty->print("\t"); } while (tty->position() < 16); 1030 nn->dump(); 1031 } 1032 if (Verbose && wlsize < _worklist.size()) { 1033 tty->print(" Push {"); 1034 while (wlsize != _worklist.size()) { 1035 Node* pushed = _worklist.at(wlsize++); 1036 tty->print(" %d", pushed->_idx); 1037 } 1038 tty->print_cr(" }"); 1039 } 1040 } 1041 if( VerifyIterativeGVN && nn != n ) { 1042 verify_step((Node*) NULL); // ignore n, it might be subsumed 1043 } 1044 #endif 1045 } else if (!n->is_top()) { 1046 remove_dead_node(n); 1047 } 1048 } 1049 1050 #ifndef PRODUCT 1051 C->verify_graph_edges(); 1052 if( VerifyOpto && allow_progress() ) { 1053 // Must turn off allow_progress to enable assert and break recursion 1054 C->root()->verify(); 1055 { // Check if any progress was missed using IterGVN 1056 // Def-Use info enables transformations not attempted in wash-pass 1057 // e.g. Region/Phi cleanup, ... 1058 // Null-check elision -- may not have reached fixpoint 1059 // do not propagate to dominated nodes 1060 ResourceMark rm; 1061 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean! 1062 // Fill worklist completely 1063 igvn2.init_worklist(C->root()); 1064 1065 igvn2.set_allow_progress(false); 1066 igvn2.optimize(); 1067 igvn2.set_allow_progress(true); 1068 } 1069 } 1070 if ( VerifyIterativeGVN && PrintOpto ) { 1071 if ( _verify_counter == _verify_full_passes ) 1072 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes", 1073 (int) _verify_full_passes); 1074 else 1075 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes", 1076 (int) _verify_counter, (int) _verify_full_passes); 1077 } 1078 #endif 1079 } 1080 1081 1082 //------------------register_new_node_with_optimizer--------------------------- 1083 // Register a new node with the optimizer. Update the types array, the def-use 1084 // info. Put on worklist. 1085 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) { 1086 set_type_bottom(n); 1087 _worklist.push(n); 1088 if (orig != NULL) C->copy_node_notes_to(n, orig); 1089 return n; 1090 } 1091 1092 //------------------------------transform-------------------------------------- 1093 // Non-recursive: idealize Node 'n' with respect to its inputs and its value 1094 Node *PhaseIterGVN::transform( Node *n ) { 1095 if (_delay_transform) { 1096 // Register the node but don't optimize for now 1097 register_new_node_with_optimizer(n); 1098 return n; 1099 } 1100 1101 // If brand new node, make space in type array, and give it a type. 1102 ensure_type_or_null(n); 1103 if (type_or_null(n) == NULL) { 1104 set_type_bottom(n); 1105 } 1106 1107 return transform_old(n); 1108 } 1109 1110 //------------------------------transform_old---------------------------------- 1111 Node *PhaseIterGVN::transform_old( Node *n ) { 1112 #ifndef PRODUCT 1113 debug_only(uint loop_count = 0;); 1114 set_transforms(); 1115 #endif 1116 // Remove 'n' from hash table in case it gets modified 1117 _table.hash_delete(n); 1118 if( VerifyIterativeGVN ) { 1119 assert( !_table.find_index(n->_idx), "found duplicate entry in table"); 1120 } 1121 1122 // Apply the Ideal call in a loop until it no longer applies 1123 Node *k = n; 1124 DEBUG_ONLY(dead_loop_check(k);) 1125 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);) 1126 Node *i = k->Ideal(this, /*can_reshape=*/true); 1127 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1128 #ifndef PRODUCT 1129 if( VerifyIterativeGVN ) 1130 verify_step(k); 1131 if( i && VerifyOpto ) { 1132 if( !allow_progress() ) { 1133 if (i->is_Add() && i->outcnt() == 1) { 1134 // Switched input to left side because this is the only use 1135 } else if( i->is_If() && (i->in(0) == NULL) ) { 1136 // This IF is dead because it is dominated by an equivalent IF When 1137 // dominating if changed, info is not propagated sparsely to 'this' 1138 // Propagating this info further will spuriously identify other 1139 // progress. 1140 return i; 1141 } else 1142 set_progress(); 1143 } else 1144 set_progress(); 1145 } 1146 #endif 1147 1148 while( i ) { 1149 #ifndef PRODUCT 1150 debug_only( if( loop_count >= K ) i->dump(4); ) 1151 assert(loop_count < K, "infinite loop in PhaseIterGVN::transform"); 1152 debug_only( loop_count++; ) 1153 #endif 1154 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes"); 1155 // Made a change; put users of original Node on worklist 1156 add_users_to_worklist( k ); 1157 // Replacing root of transform tree? 1158 if( k != i ) { 1159 // Make users of old Node now use new. 1160 subsume_node( k, i ); 1161 k = i; 1162 } 1163 DEBUG_ONLY(dead_loop_check(k);) 1164 // Try idealizing again 1165 DEBUG_ONLY(is_new = (k->outcnt() == 0);) 1166 i = k->Ideal(this, /*can_reshape=*/true); 1167 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1168 #ifndef PRODUCT 1169 if( VerifyIterativeGVN ) 1170 verify_step(k); 1171 if( i && VerifyOpto ) set_progress(); 1172 #endif 1173 } 1174 1175 // If brand new node, make space in type array. 1176 ensure_type_or_null(k); 1177 1178 // See what kind of values 'k' takes on at runtime 1179 const Type *t = k->Value(this); 1180 assert(t != NULL, "value sanity"); 1181 1182 // Since I just called 'Value' to compute the set of run-time values 1183 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 1184 // cache Value. Later requests for the local phase->type of this Node can 1185 // use the cached Value instead of suffering with 'bottom_type'. 1186 if (t != type_or_null(k)) { 1187 NOT_PRODUCT( set_progress(); ) 1188 NOT_PRODUCT( inc_new_values();) 1189 set_type(k, t); 1190 // If k is a TypeNode, capture any more-precise type permanently into Node 1191 k->raise_bottom_type(t); 1192 // Move users of node to worklist 1193 add_users_to_worklist( k ); 1194 } 1195 1196 // If 'k' computes a constant, replace it with a constant 1197 if( t->singleton() && !k->is_Con() ) { 1198 NOT_PRODUCT( set_progress(); ) 1199 Node *con = makecon(t); // Make a constant 1200 add_users_to_worklist( k ); 1201 subsume_node( k, con ); // Everybody using k now uses con 1202 return con; 1203 } 1204 1205 // Now check for Identities 1206 i = k->Identity(this); // Look for a nearby replacement 1207 if( i != k ) { // Found? Return replacement! 1208 NOT_PRODUCT( set_progress(); ) 1209 add_users_to_worklist( k ); 1210 subsume_node( k, i ); // Everybody using k now uses i 1211 return i; 1212 } 1213 1214 // Global Value Numbering 1215 i = hash_find_insert(k); // Check for pre-existing node 1216 if( i && (i != k) ) { 1217 // Return the pre-existing node if it isn't dead 1218 NOT_PRODUCT( set_progress(); ) 1219 add_users_to_worklist( k ); 1220 subsume_node( k, i ); // Everybody using k now uses i 1221 return i; 1222 } 1223 1224 // Return Idealized original 1225 return k; 1226 } 1227 1228 //---------------------------------saturate------------------------------------ 1229 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type, 1230 const Type* limit_type) const { 1231 return new_type->narrow(old_type); 1232 } 1233 1234 //------------------------------remove_globally_dead_node---------------------- 1235 // Kill a globally dead Node. All uses are also globally dead and are 1236 // aggressively trimmed. 1237 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) { 1238 enum DeleteProgress { 1239 PROCESS_INPUTS, 1240 PROCESS_OUTPUTS 1241 }; 1242 assert(_stack.is_empty(), "not empty"); 1243 _stack.push(dead, PROCESS_INPUTS); 1244 1245 while (_stack.is_nonempty()) { 1246 dead = _stack.node(); 1247 if (dead->Opcode() == Op_SafePoint) { 1248 dead->as_SafePoint()->disconnect_from_root(this); 1249 } 1250 uint progress_state = _stack.index(); 1251 assert(dead != C->root(), "killing root, eh?"); 1252 assert(!dead->is_top(), "add check for top when pushing"); 1253 NOT_PRODUCT( set_progress(); ) 1254 if (progress_state == PROCESS_INPUTS) { 1255 // After following inputs, continue to outputs 1256 _stack.set_index(PROCESS_OUTPUTS); 1257 if (!dead->is_Con()) { // Don't kill cons but uses 1258 bool recurse = false; 1259 // Remove from hash table 1260 _table.hash_delete( dead ); 1261 // Smash all inputs to 'dead', isolating him completely 1262 for (uint i = 0; i < dead->req(); i++) { 1263 Node *in = dead->in(i); 1264 if (in != NULL && in != C->top()) { // Points to something? 1265 int nrep = dead->replace_edge(in, NULL); // Kill edges 1266 assert((nrep > 0), "sanity"); 1267 if (in->outcnt() == 0) { // Made input go dead? 1268 _stack.push(in, PROCESS_INPUTS); // Recursively remove 1269 recurse = true; 1270 } else if (in->outcnt() == 1 && 1271 in->has_special_unique_user()) { 1272 _worklist.push(in->unique_out()); 1273 } else if (in->outcnt() <= 2 && dead->is_Phi()) { 1274 if (in->Opcode() == Op_Region) { 1275 _worklist.push(in); 1276 } else if (in->is_Store()) { 1277 DUIterator_Fast imax, i = in->fast_outs(imax); 1278 _worklist.push(in->fast_out(i)); 1279 i++; 1280 if (in->outcnt() == 2) { 1281 _worklist.push(in->fast_out(i)); 1282 i++; 1283 } 1284 assert(!(i < imax), "sanity"); 1285 } 1286 } 1287 if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory && 1288 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) { 1289 // A Load that directly follows an InitializeNode is 1290 // going away. The Stores that follow are candidates 1291 // again to be captured by the InitializeNode. 1292 for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) { 1293 Node *n = in->fast_out(j); 1294 if (n->is_Store()) { 1295 _worklist.push(n); 1296 } 1297 } 1298 } 1299 } // if (in != NULL && in != C->top()) 1300 } // for (uint i = 0; i < dead->req(); i++) 1301 if (recurse) { 1302 continue; 1303 } 1304 } // if (!dead->is_Con()) 1305 } // if (progress_state == PROCESS_INPUTS) 1306 1307 // Aggressively kill globally dead uses 1308 // (Rather than pushing all the outs at once, we push one at a time, 1309 // plus the parent to resume later, because of the indefinite number 1310 // of edge deletions per loop trip.) 1311 if (dead->outcnt() > 0) { 1312 // Recursively remove output edges 1313 _stack.push(dead->raw_out(0), PROCESS_INPUTS); 1314 } else { 1315 // Finished disconnecting all input and output edges. 1316 _stack.pop(); 1317 // Remove dead node from iterative worklist 1318 _worklist.remove(dead); 1319 // Constant node that has no out-edges and has only one in-edge from 1320 // root is usually dead. However, sometimes reshaping walk makes 1321 // it reachable by adding use edges. So, we will NOT count Con nodes 1322 // as dead to be conservative about the dead node count at any 1323 // given time. 1324 if (!dead->is_Con()) { 1325 C->record_dead_node(dead->_idx); 1326 } 1327 if (dead->is_macro()) { 1328 C->remove_macro_node(dead); 1329 } 1330 if (dead->is_expensive()) { 1331 C->remove_expensive_node(dead); 1332 } 1333 CastIINode* cast = dead->isa_CastII(); 1334 if (cast != NULL && cast->has_range_check()) { 1335 C->remove_range_check_cast(cast); 1336 } 1337 } 1338 } // while (_stack.is_nonempty()) 1339 } 1340 1341 //------------------------------subsume_node----------------------------------- 1342 // Remove users from node 'old' and add them to node 'nn'. 1343 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) { 1344 if (old->Opcode() == Op_SafePoint) { 1345 old->as_SafePoint()->disconnect_from_root(this); 1346 } 1347 assert( old != hash_find(old), "should already been removed" ); 1348 assert( old != C->top(), "cannot subsume top node"); 1349 // Copy debug or profile information to the new version: 1350 C->copy_node_notes_to(nn, old); 1351 // Move users of node 'old' to node 'nn' 1352 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) { 1353 Node* use = old->last_out(i); // for each use... 1354 // use might need re-hashing (but it won't if it's a new node) 1355 bool is_in_table = _table.hash_delete( use ); 1356 // Update use-def info as well 1357 // We remove all occurrences of old within use->in, 1358 // so as to avoid rehashing any node more than once. 1359 // The hash table probe swamps any outer loop overhead. 1360 uint num_edges = 0; 1361 for (uint jmax = use->len(), j = 0; j < jmax; j++) { 1362 if (use->in(j) == old) { 1363 use->set_req(j, nn); 1364 ++num_edges; 1365 } 1366 } 1367 // Insert into GVN hash table if unique 1368 // If a duplicate, 'use' will be cleaned up when pulled off worklist 1369 if( is_in_table ) { 1370 hash_find_insert(use); 1371 } 1372 i -= num_edges; // we deleted 1 or more copies of this edge 1373 } 1374 1375 // Search for instance field data PhiNodes in the same region pointing to the old 1376 // memory PhiNode and update their instance memory ids to point to the new node. 1377 if (old->is_Phi() && old->as_Phi()->type()->has_memory() && old->in(0) != NULL) { 1378 Node* region = old->in(0); 1379 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { 1380 PhiNode* phi = region->fast_out(i)->isa_Phi(); 1381 if (phi != NULL && phi->inst_mem_id() == (int)old->_idx) { 1382 phi->set_inst_mem_id((int)nn->_idx); 1383 } 1384 } 1385 } 1386 1387 // Smash all inputs to 'old', isolating him completely 1388 Node *temp = new (C) Node(1); 1389 temp->init_req(0,nn); // Add a use to nn to prevent him from dying 1390 remove_dead_node( old ); 1391 temp->del_req(0); // Yank bogus edge 1392 #ifndef PRODUCT 1393 if( VerifyIterativeGVN ) { 1394 for ( int i = 0; i < _verify_window_size; i++ ) { 1395 if ( _verify_window[i] == old ) 1396 _verify_window[i] = nn; 1397 } 1398 } 1399 #endif 1400 _worklist.remove(temp); // this can be necessary 1401 temp->destruct(); // reuse the _idx of this little guy 1402 } 1403 1404 //------------------------------add_users_to_worklist-------------------------- 1405 void PhaseIterGVN::add_users_to_worklist0( Node *n ) { 1406 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1407 _worklist.push(n->fast_out(i)); // Push on worklist 1408 } 1409 } 1410 1411 // Return counted loop Phi if as a counted loop exit condition, cmp 1412 // compares the the induction variable with n 1413 static PhiNode* countedloop_phi_from_cmp(CmpINode* cmp, Node* n) { 1414 for (DUIterator_Fast imax, i = cmp->fast_outs(imax); i < imax; i++) { 1415 Node* bol = cmp->fast_out(i); 1416 for (DUIterator_Fast i2max, i2 = bol->fast_outs(i2max); i2 < i2max; i2++) { 1417 Node* iff = bol->fast_out(i2); 1418 if (iff->is_CountedLoopEnd()) { 1419 CountedLoopEndNode* cle = iff->as_CountedLoopEnd(); 1420 if (cle->limit() == n) { 1421 PhiNode* phi = cle->phi(); 1422 if (phi != NULL) { 1423 return phi; 1424 } 1425 } 1426 } 1427 } 1428 } 1429 return NULL; 1430 } 1431 1432 void PhaseIterGVN::add_users_to_worklist( Node *n ) { 1433 add_users_to_worklist0(n); 1434 1435 // Move users of node to worklist 1436 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1437 Node* use = n->fast_out(i); // Get use 1438 1439 if( use->is_Multi() || // Multi-definer? Push projs on worklist 1440 use->is_Store() ) // Enable store/load same address 1441 add_users_to_worklist0(use); 1442 1443 // If we changed the receiver type to a call, we need to revisit 1444 // the Catch following the call. It's looking for a non-NULL 1445 // receiver to know when to enable the regular fall-through path 1446 // in addition to the NullPtrException path. 1447 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) { 1448 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control); 1449 if (p != NULL) { 1450 add_users_to_worklist0(p); 1451 } 1452 } 1453 1454 uint use_op = use->Opcode(); 1455 if(use->is_Cmp()) { // Enable CMP/BOOL optimization 1456 add_users_to_worklist(use); // Put Bool on worklist 1457 if (use->outcnt() > 0) { 1458 Node* bol = use->raw_out(0); 1459 if (bol->outcnt() > 0) { 1460 Node* iff = bol->raw_out(0); 1461 if (iff->outcnt() == 2) { 1462 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the 1463 // phi merging either 0 or 1 onto the worklist 1464 Node* ifproj0 = iff->raw_out(0); 1465 Node* ifproj1 = iff->raw_out(1); 1466 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) { 1467 Node* region0 = ifproj0->raw_out(0); 1468 Node* region1 = ifproj1->raw_out(0); 1469 if( region0 == region1 ) 1470 add_users_to_worklist0(region0); 1471 } 1472 } 1473 } 1474 } 1475 if (use_op == Op_CmpI) { 1476 Node* phi = countedloop_phi_from_cmp((CmpINode*)use, n); 1477 if (phi != NULL) { 1478 // If an opaque node feeds into the limit condition of a 1479 // CountedLoop, we need to process the Phi node for the 1480 // induction variable when the opaque node is removed: 1481 // the range of values taken by the Phi is now known and 1482 // so its type is also known. 1483 _worklist.push(phi); 1484 } 1485 Node* in1 = use->in(1); 1486 for (uint i = 0; i < in1->outcnt(); i++) { 1487 if (in1->raw_out(i)->Opcode() == Op_CastII) { 1488 Node* castii = in1->raw_out(i); 1489 if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) { 1490 Node* ifnode = castii->in(0)->in(0); 1491 if (ifnode->in(1) != NULL && ifnode->in(1)->is_Bool() && ifnode->in(1)->in(1) == use) { 1492 // Reprocess a CastII node that may depend on an 1493 // opaque node value when the opaque node is 1494 // removed. In case it carries a dependency we can do 1495 // a better job of computing its type. 1496 _worklist.push(castii); 1497 } 1498 } 1499 } 1500 } 1501 } 1502 } 1503 1504 // If changed Cast input, check Phi users for simple cycles 1505 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) { 1506 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1507 Node* u = use->fast_out(i2); 1508 if (u->is_Phi()) 1509 _worklist.push(u); 1510 } 1511 } 1512 // If changed LShift inputs, check RShift users for useless sign-ext 1513 if( use_op == Op_LShiftI ) { 1514 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1515 Node* u = use->fast_out(i2); 1516 if (u->Opcode() == Op_RShiftI) 1517 _worklist.push(u); 1518 } 1519 } 1520 // If changed AddI/SubI inputs, check CmpU for range check optimization. 1521 if (use_op == Op_AddI || use_op == Op_SubI) { 1522 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1523 Node* u = use->fast_out(i2); 1524 if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) { 1525 _worklist.push(u); 1526 } 1527 } 1528 } 1529 // If changed AddP inputs, check Stores for loop invariant 1530 if( use_op == Op_AddP ) { 1531 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1532 Node* u = use->fast_out(i2); 1533 if (u->is_Mem()) 1534 _worklist.push(u); 1535 } 1536 } 1537 // If changed initialization activity, check dependent Stores 1538 if (use_op == Op_Allocate || use_op == Op_AllocateArray) { 1539 InitializeNode* init = use->as_Allocate()->initialization(); 1540 if (init != NULL) { 1541 Node* imem = init->proj_out(TypeFunc::Memory); 1542 if (imem != NULL) add_users_to_worklist0(imem); 1543 } 1544 } 1545 if (use_op == Op_Initialize) { 1546 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory); 1547 if (imem != NULL) add_users_to_worklist0(imem); 1548 } 1549 } 1550 } 1551 1552 /** 1553 * Remove the speculative part of all types that we know of 1554 */ 1555 void PhaseIterGVN::remove_speculative_types() { 1556 assert(UseTypeSpeculation, "speculation is off"); 1557 for (uint i = 0; i < _types.Size(); i++) { 1558 const Type* t = _types.fast_lookup(i); 1559 if (t != NULL) { 1560 _types.map(i, t->remove_speculative()); 1561 } 1562 } 1563 _table.check_no_speculative_types(); 1564 } 1565 1566 //============================================================================= 1567 #ifndef PRODUCT 1568 uint PhaseCCP::_total_invokes = 0; 1569 uint PhaseCCP::_total_constants = 0; 1570 #endif 1571 //------------------------------PhaseCCP--------------------------------------- 1572 // Conditional Constant Propagation, ala Wegman & Zadeck 1573 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) { 1574 NOT_PRODUCT( clear_constants(); ) 1575 assert( _worklist.size() == 0, "" ); 1576 // Clear out _nodes from IterGVN. Must be clear to transform call. 1577 _nodes.clear(); // Clear out from IterGVN 1578 analyze(); 1579 } 1580 1581 #ifndef PRODUCT 1582 //------------------------------~PhaseCCP-------------------------------------- 1583 PhaseCCP::~PhaseCCP() { 1584 inc_invokes(); 1585 _total_constants += count_constants(); 1586 } 1587 #endif 1588 1589 1590 #ifdef ASSERT 1591 static bool ccp_type_widens(const Type* t, const Type* t0) { 1592 assert(t->meet(t0) == t, "Not monotonic"); 1593 switch (t->base() == t0->base() ? t->base() : Type::Top) { 1594 case Type::Int: 1595 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases"); 1596 break; 1597 case Type::Long: 1598 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases"); 1599 break; 1600 } 1601 return true; 1602 } 1603 #endif //ASSERT 1604 1605 //------------------------------analyze---------------------------------------- 1606 void PhaseCCP::analyze() { 1607 // Initialize all types to TOP, optimistic analysis 1608 for (int i = C->unique() - 1; i >= 0; i--) { 1609 _types.map(i,Type::TOP); 1610 } 1611 1612 // Push root onto worklist 1613 Unique_Node_List worklist; 1614 worklist.push(C->root()); 1615 1616 // Pull from worklist; compute new value; push changes out. 1617 // This loop is the meat of CCP. 1618 while( worklist.size() ) { 1619 Node *n = worklist.pop(); 1620 const Type *t = n->Value(this); 1621 if (t != type(n)) { 1622 assert(ccp_type_widens(t, type(n)), "ccp type must widen"); 1623 #ifndef PRODUCT 1624 if( TracePhaseCCP ) { 1625 t->dump(); 1626 do { tty->print("\t"); } while (tty->position() < 16); 1627 n->dump(); 1628 } 1629 #endif 1630 set_type(n, t); 1631 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1632 Node* m = n->fast_out(i); // Get user 1633 if (m->is_Region()) { // New path to Region? Must recheck Phis too 1634 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1635 Node* p = m->fast_out(i2); // Propagate changes to uses 1636 if (p->bottom_type() != type(p)) { // If not already bottomed out 1637 worklist.push(p); // Propagate change to user 1638 } 1639 } 1640 } 1641 // If we changed the receiver type to a call, we need to revisit 1642 // the Catch following the call. It's looking for a non-NULL 1643 // receiver to know when to enable the regular fall-through path 1644 // in addition to the NullPtrException path 1645 if (m->is_Call()) { 1646 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1647 Node* p = m->fast_out(i2); // Propagate changes to uses 1648 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control) { 1649 Node* catch_node = p->find_out_with(Op_Catch); 1650 if (catch_node != NULL) { 1651 worklist.push(catch_node); 1652 } 1653 } 1654 } 1655 } 1656 if (m->bottom_type() != type(m)) { // If not already bottomed out 1657 worklist.push(m); // Propagate change to user 1658 } 1659 1660 // CmpU nodes can get their type information from two nodes up in the 1661 // graph (instead of from the nodes immediately above). Make sure they 1662 // are added to the worklist if nodes they depend on are updated, since 1663 // they could be missed and get wrong types otherwise. 1664 uint m_op = m->Opcode(); 1665 if (m_op == Op_AddI || m_op == Op_SubI) { 1666 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1667 Node* p = m->fast_out(i2); // Propagate changes to uses 1668 if (p->Opcode() == Op_CmpU) { 1669 // Got a CmpU which might need the new type information from node n. 1670 if(p->bottom_type() != type(p)) { // If not already bottomed out 1671 worklist.push(p); // Propagate change to user 1672 } 1673 } 1674 } 1675 } 1676 // If n is used in a counted loop exit condition then the type 1677 // of the counted loop's Phi depends on the type of n. See 1678 // PhiNode::Value(). 1679 if (m_op == Op_CmpI) { 1680 PhiNode* phi = countedloop_phi_from_cmp((CmpINode*)m, n); 1681 if (phi != NULL) { 1682 worklist.push(phi); 1683 } 1684 } 1685 } 1686 } 1687 } 1688 } 1689 1690 //------------------------------do_transform----------------------------------- 1691 // Top level driver for the recursive transformer 1692 void PhaseCCP::do_transform() { 1693 // Correct leaves of new-space Nodes; they point to old-space. 1694 C->set_root( transform(C->root())->as_Root() ); 1695 assert( C->top(), "missing TOP node" ); 1696 assert( C->root(), "missing root" ); 1697 } 1698 1699 //------------------------------transform-------------------------------------- 1700 // Given a Node in old-space, clone him into new-space. 1701 // Convert any of his old-space children into new-space children. 1702 Node *PhaseCCP::transform( Node *n ) { 1703 Node *new_node = _nodes[n->_idx]; // Check for transformed node 1704 if( new_node != NULL ) 1705 return new_node; // Been there, done that, return old answer 1706 new_node = transform_once(n); // Check for constant 1707 _nodes.map( n->_idx, new_node ); // Flag as having been cloned 1708 1709 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc 1710 GrowableArray <Node *> trstack(C->live_nodes() >> 1); 1711 1712 trstack.push(new_node); // Process children of cloned node 1713 while ( trstack.is_nonempty() ) { 1714 Node *clone = trstack.pop(); 1715 uint cnt = clone->req(); 1716 for( uint i = 0; i < cnt; i++ ) { // For all inputs do 1717 Node *input = clone->in(i); 1718 if( input != NULL ) { // Ignore NULLs 1719 Node *new_input = _nodes[input->_idx]; // Check for cloned input node 1720 if( new_input == NULL ) { 1721 new_input = transform_once(input); // Check for constant 1722 _nodes.map( input->_idx, new_input );// Flag as having been cloned 1723 trstack.push(new_input); 1724 } 1725 assert( new_input == clone->in(i), "insanity check"); 1726 } 1727 } 1728 } 1729 return new_node; 1730 } 1731 1732 1733 //------------------------------transform_once--------------------------------- 1734 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant. 1735 Node *PhaseCCP::transform_once( Node *n ) { 1736 const Type *t = type(n); 1737 // Constant? Use constant Node instead 1738 if( t->singleton() ) { 1739 Node *nn = n; // Default is to return the original constant 1740 if( t == Type::TOP ) { 1741 // cache my top node on the Compile instance 1742 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) { 1743 C->set_cached_top_node( ConNode::make(C, Type::TOP) ); 1744 set_type(C->top(), Type::TOP); 1745 } 1746 nn = C->top(); 1747 } 1748 if( !n->is_Con() ) { 1749 if( t != Type::TOP ) { 1750 nn = makecon(t); // ConNode::make(t); 1751 NOT_PRODUCT( inc_constants(); ) 1752 } else if( n->is_Region() ) { // Unreachable region 1753 // Note: nn == C->top() 1754 n->set_req(0, NULL); // Cut selfreference 1755 // Eagerly remove dead phis to avoid phis copies creation. 1756 for (DUIterator i = n->outs(); n->has_out(i); i++) { 1757 Node* m = n->out(i); 1758 if( m->is_Phi() ) { 1759 assert(type(m) == Type::TOP, "Unreachable region should not have live phis."); 1760 replace_node(m, nn); 1761 --i; // deleted this phi; rescan starting with next position 1762 } 1763 } 1764 } 1765 replace_node(n,nn); // Update DefUse edges for new constant 1766 } 1767 return nn; 1768 } 1769 1770 // If x is a TypeNode, capture any more-precise type permanently into Node 1771 if (t != n->bottom_type()) { 1772 hash_delete(n); // changing bottom type may force a rehash 1773 n->raise_bottom_type(t); 1774 _worklist.push(n); // n re-enters the hash table via the worklist 1775 } 1776 1777 // Idealize graph using DU info. Must clone() into new-space. 1778 // DU info is generally used to show profitability, progress or safety 1779 // (but generally not needed for correctness). 1780 Node *nn = n->Ideal_DU_postCCP(this); 1781 1782 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks 1783 switch( n->Opcode() ) { 1784 case Op_FastLock: // Revisit FastLocks for lock coarsening 1785 case Op_If: 1786 case Op_CountedLoopEnd: 1787 case Op_Region: 1788 case Op_Loop: 1789 case Op_CountedLoop: 1790 case Op_Conv2B: 1791 case Op_Opaque1: 1792 case Op_Opaque2: 1793 _worklist.push(n); 1794 break; 1795 default: 1796 break; 1797 } 1798 if( nn ) { 1799 _worklist.push(n); 1800 // Put users of 'n' onto worklist for second igvn transform 1801 add_users_to_worklist(n); 1802 return nn; 1803 } 1804 1805 return n; 1806 } 1807 1808 //---------------------------------saturate------------------------------------ 1809 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type, 1810 const Type* limit_type) const { 1811 const Type* wide_type = new_type->widen(old_type, limit_type); 1812 if (wide_type != new_type) { // did we widen? 1813 // If so, we may have widened beyond the limit type. Clip it back down. 1814 new_type = wide_type->filter(limit_type); 1815 } 1816 return new_type; 1817 } 1818 1819 //------------------------------print_statistics------------------------------- 1820 #ifndef PRODUCT 1821 void PhaseCCP::print_statistics() { 1822 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants); 1823 } 1824 #endif 1825 1826 1827 //============================================================================= 1828 #ifndef PRODUCT 1829 uint PhasePeephole::_total_peepholes = 0; 1830 #endif 1831 //------------------------------PhasePeephole---------------------------------- 1832 // Conditional Constant Propagation, ala Wegman & Zadeck 1833 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ) 1834 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) { 1835 NOT_PRODUCT( clear_peepholes(); ) 1836 } 1837 1838 #ifndef PRODUCT 1839 //------------------------------~PhasePeephole--------------------------------- 1840 PhasePeephole::~PhasePeephole() { 1841 _total_peepholes += count_peepholes(); 1842 } 1843 #endif 1844 1845 //------------------------------transform-------------------------------------- 1846 Node *PhasePeephole::transform( Node *n ) { 1847 ShouldNotCallThis(); 1848 return NULL; 1849 } 1850 1851 //------------------------------do_transform----------------------------------- 1852 void PhasePeephole::do_transform() { 1853 bool method_name_not_printed = true; 1854 1855 // Examine each basic block 1856 for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) { 1857 Block* block = _cfg.get_block(block_number); 1858 bool block_not_printed = true; 1859 1860 // and each instruction within a block 1861 uint end_index = block->number_of_nodes(); 1862 // block->end_idx() not valid after PhaseRegAlloc 1863 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) { 1864 Node *n = block->get_node(instruction_index); 1865 if( n->is_Mach() ) { 1866 MachNode *m = n->as_Mach(); 1867 int deleted_count = 0; 1868 // check for peephole opportunities 1869 MachNode *m2 = m->peephole( block, instruction_index, _regalloc, deleted_count, C ); 1870 if( m2 != NULL ) { 1871 #ifndef PRODUCT 1872 if( PrintOptoPeephole ) { 1873 // Print method, first time only 1874 if( C->method() && method_name_not_printed ) { 1875 C->method()->print_short_name(); tty->cr(); 1876 method_name_not_printed = false; 1877 } 1878 // Print this block 1879 if( Verbose && block_not_printed) { 1880 tty->print_cr("in block"); 1881 block->dump(); 1882 block_not_printed = false; 1883 } 1884 // Print instructions being deleted 1885 for( int i = (deleted_count - 1); i >= 0; --i ) { 1886 block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr(); 1887 } 1888 tty->print_cr("replaced with"); 1889 // Print new instruction 1890 m2->format(_regalloc); 1891 tty->print("\n\n"); 1892 } 1893 #endif 1894 // Remove old nodes from basic block and update instruction_index 1895 // (old nodes still exist and may have edges pointing to them 1896 // as register allocation info is stored in the allocator using 1897 // the node index to live range mappings.) 1898 uint safe_instruction_index = (instruction_index - deleted_count); 1899 for( ; (instruction_index > safe_instruction_index); --instruction_index ) { 1900 block->remove_node( instruction_index ); 1901 } 1902 // install new node after safe_instruction_index 1903 block->insert_node(m2, safe_instruction_index + 1); 1904 end_index = block->number_of_nodes() - 1; // Recompute new block size 1905 NOT_PRODUCT( inc_peepholes(); ) 1906 } 1907 } 1908 } 1909 } 1910 } 1911 1912 //------------------------------print_statistics------------------------------- 1913 #ifndef PRODUCT 1914 void PhasePeephole::print_statistics() { 1915 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes); 1916 } 1917 #endif 1918 1919 1920 //============================================================================= 1921 //------------------------------set_req_X-------------------------------------- 1922 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) { 1923 assert( is_not_dead(n), "can not use dead node"); 1924 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" ); 1925 Node *old = in(i); 1926 set_req(i, n); 1927 1928 // old goes dead? 1929 if( old ) { 1930 switch (old->outcnt()) { 1931 case 0: 1932 // Put into the worklist to kill later. We do not kill it now because the 1933 // recursive kill will delete the current node (this) if dead-loop exists 1934 if (!old->is_top()) 1935 igvn->_worklist.push( old ); 1936 break; 1937 case 1: 1938 if( old->is_Store() || old->has_special_unique_user() ) 1939 igvn->add_users_to_worklist( old ); 1940 break; 1941 case 2: 1942 if( old->is_Store() ) 1943 igvn->add_users_to_worklist( old ); 1944 if( old->Opcode() == Op_Region ) 1945 igvn->_worklist.push(old); 1946 break; 1947 case 3: 1948 if( old->Opcode() == Op_Region ) { 1949 igvn->_worklist.push(old); 1950 igvn->add_users_to_worklist( old ); 1951 } 1952 break; 1953 default: 1954 break; 1955 } 1956 } 1957 1958 } 1959 1960 //-------------------------------replace_by----------------------------------- 1961 // Using def-use info, replace one node for another. Follow the def-use info 1962 // to all users of the OLD node. Then make all uses point to the NEW node. 1963 void Node::replace_by(Node *new_node) { 1964 assert(!is_top(), "top node has no DU info"); 1965 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) { 1966 Node* use = last_out(i); 1967 uint uses_found = 0; 1968 for (uint j = 0; j < use->len(); j++) { 1969 if (use->in(j) == this) { 1970 if (j < use->req()) 1971 use->set_req(j, new_node); 1972 else use->set_prec(j, new_node); 1973 uses_found++; 1974 } 1975 } 1976 i -= uses_found; // we deleted 1 or more copies of this edge 1977 } 1978 } 1979 1980 //============================================================================= 1981 //----------------------------------------------------------------------------- 1982 void Type_Array::grow( uint i ) { 1983 if( !_max ) { 1984 _max = 1; 1985 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) ); 1986 _types[0] = NULL; 1987 } 1988 uint old = _max; 1989 while( i >= _max ) _max <<= 1; // Double to fit 1990 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*)); 1991 memset( &_types[old], 0, (_max-old)*sizeof(Type*) ); 1992 } 1993 1994 //------------------------------dump------------------------------------------- 1995 #ifndef PRODUCT 1996 void Type_Array::dump() const { 1997 uint max = Size(); 1998 for( uint i = 0; i < max; i++ ) { 1999 if( _types[i] != NULL ) { 2000 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr(); 2001 } 2002 } 2003 } 2004 #endif