1 /* 2 * Copyright (c) 1997, 2009, 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 "incls/_precompiled.incl" 26 #include "incls/_phaseX.cpp.incl" 27 28 //============================================================================= 29 #define NODE_HASH_MINIMUM_SIZE 255 30 //------------------------------NodeHash--------------------------------------- 31 NodeHash::NodeHash(uint est_max_size) : 32 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), 33 _a(Thread::current()->resource_area()), 34 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ), 35 _inserts(0), _insert_limit( insert_limit() ), 36 _look_probes(0), _lookup_hits(0), _lookup_misses(0), 37 _total_insert_probes(0), _total_inserts(0), 38 _insert_probes(0), _grows(0) { 39 // _sentinel must be in the current node space 40 _sentinel = new (Compile::current(), 1) ProjNode(NULL, TypeFunc::Control); 41 memset(_table,0,sizeof(Node*)*_max); 42 } 43 44 //------------------------------NodeHash--------------------------------------- 45 NodeHash::NodeHash(Arena *arena, uint est_max_size) : 46 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ), 47 _a(arena), 48 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), 49 _inserts(0), _insert_limit( insert_limit() ), 50 _look_probes(0), _lookup_hits(0), _lookup_misses(0), 51 _delete_probes(0), _delete_hits(0), _delete_misses(0), 52 _total_insert_probes(0), _total_inserts(0), 53 _insert_probes(0), _grows(0) { 54 // _sentinel must be in the current node space 55 _sentinel = new (Compile::current(), 1) ProjNode(NULL, TypeFunc::Control); 56 memset(_table,0,sizeof(Node*)*_max); 57 } 58 59 //------------------------------NodeHash--------------------------------------- 60 NodeHash::NodeHash(NodeHash *nh) { 61 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator= 62 // just copy in all the fields 63 *this = *nh; 64 // nh->_sentinel must be in the current node space 65 } 66 67 //------------------------------hash_find-------------------------------------- 68 // Find in hash table 69 Node *NodeHash::hash_find( const Node *n ) { 70 // ((Node*)n)->set_hash( n->hash() ); 71 uint hash = n->hash(); 72 if (hash == Node::NO_HASH) { 73 debug_only( _lookup_misses++ ); 74 return NULL; 75 } 76 uint key = hash & (_max-1); 77 uint stride = key | 0x01; 78 debug_only( _look_probes++ ); 79 Node *k = _table[key]; // Get hashed value 80 if( !k ) { // ?Miss? 81 debug_only( _lookup_misses++ ); 82 return NULL; // Miss! 83 } 84 85 int op = n->Opcode(); 86 uint req = n->req(); 87 while( 1 ) { // While probing hash table 88 if( k->req() == req && // Same count of inputs 89 k->Opcode() == op ) { // Same Opcode 90 for( uint i=0; i<req; i++ ) 91 if( n->in(i)!=k->in(i)) // Different inputs? 92 goto collision; // "goto" is a speed hack... 93 if( n->cmp(*k) ) { // Check for any special bits 94 debug_only( _lookup_hits++ ); 95 return k; // Hit! 96 } 97 } 98 collision: 99 debug_only( _look_probes++ ); 100 key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime 101 k = _table[key]; // Get hashed value 102 if( !k ) { // ?Miss? 103 debug_only( _lookup_misses++ ); 104 return NULL; // Miss! 105 } 106 } 107 ShouldNotReachHere(); 108 return NULL; 109 } 110 111 //------------------------------hash_find_insert------------------------------- 112 // Find in hash table, insert if not already present 113 // Used to preserve unique entries in hash table 114 Node *NodeHash::hash_find_insert( Node *n ) { 115 // n->set_hash( ); 116 uint hash = n->hash(); 117 if (hash == Node::NO_HASH) { 118 debug_only( _lookup_misses++ ); 119 return NULL; 120 } 121 uint key = hash & (_max-1); 122 uint stride = key | 0x01; // stride must be relatively prime to table siz 123 uint first_sentinel = 0; // replace a sentinel if seen. 124 debug_only( _look_probes++ ); 125 Node *k = _table[key]; // Get hashed value 126 if( !k ) { // ?Miss? 127 debug_only( _lookup_misses++ ); 128 _table[key] = n; // Insert into table! 129 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 130 check_grow(); // Grow table if insert hit limit 131 return NULL; // Miss! 132 } 133 else if( k == _sentinel ) { 134 first_sentinel = key; // Can insert here 135 } 136 137 int op = n->Opcode(); 138 uint req = n->req(); 139 while( 1 ) { // While probing hash table 140 if( k->req() == req && // Same count of inputs 141 k->Opcode() == op ) { // Same Opcode 142 for( uint i=0; i<req; i++ ) 143 if( n->in(i)!=k->in(i)) // Different inputs? 144 goto collision; // "goto" is a speed hack... 145 if( n->cmp(*k) ) { // Check for any special bits 146 debug_only( _lookup_hits++ ); 147 return k; // Hit! 148 } 149 } 150 collision: 151 debug_only( _look_probes++ ); 152 key = (key + stride) & (_max-1); // Stride through table w/ relative prime 153 k = _table[key]; // Get hashed value 154 if( !k ) { // ?Miss? 155 debug_only( _lookup_misses++ ); 156 key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel? 157 _table[key] = n; // Insert into table! 158 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 159 check_grow(); // Grow table if insert hit limit 160 return NULL; // Miss! 161 } 162 else if( first_sentinel == 0 && k == _sentinel ) { 163 first_sentinel = key; // Can insert here 164 } 165 166 } 167 ShouldNotReachHere(); 168 return NULL; 169 } 170 171 //------------------------------hash_insert------------------------------------ 172 // Insert into hash table 173 void NodeHash::hash_insert( Node *n ) { 174 // // "conflict" comments -- print nodes that conflict 175 // bool conflict = false; 176 // n->set_hash(); 177 uint hash = n->hash(); 178 if (hash == Node::NO_HASH) { 179 return; 180 } 181 check_grow(); 182 uint key = hash & (_max-1); 183 uint stride = key | 0x01; 184 185 while( 1 ) { // While probing hash table 186 debug_only( _insert_probes++ ); 187 Node *k = _table[key]; // Get hashed value 188 if( !k || (k == _sentinel) ) break; // Found a slot 189 assert( k != n, "already inserted" ); 190 // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; } 191 key = (key + stride) & (_max-1); // Stride through table w/ relative prime 192 } 193 _table[key] = n; // Insert into table! 194 debug_only(n->enter_hash_lock()); // Lock down the node while in the table. 195 // if( conflict ) { n->dump(); } 196 } 197 198 //------------------------------hash_delete------------------------------------ 199 // Replace in hash table with sentinel 200 bool NodeHash::hash_delete( const Node *n ) { 201 Node *k; 202 uint hash = n->hash(); 203 if (hash == Node::NO_HASH) { 204 debug_only( _delete_misses++ ); 205 return false; 206 } 207 uint key = hash & (_max-1); 208 uint stride = key | 0x01; 209 debug_only( uint counter = 0; ); 210 for( ; /* (k != NULL) && (k != _sentinel) */; ) { 211 debug_only( counter++ ); 212 debug_only( _delete_probes++ ); 213 k = _table[key]; // Get hashed value 214 if( !k ) { // Miss? 215 debug_only( _delete_misses++ ); 216 #ifdef ASSERT 217 if( VerifyOpto ) { 218 for( uint i=0; i < _max; i++ ) 219 assert( _table[i] != n, "changed edges with rehashing" ); 220 } 221 #endif 222 return false; // Miss! Not in chain 223 } 224 else if( n == k ) { 225 debug_only( _delete_hits++ ); 226 _table[key] = _sentinel; // Hit! Label as deleted entry 227 debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table. 228 return true; 229 } 230 else { 231 // collision: move through table with prime offset 232 key = (key + stride/*7*/) & (_max-1); 233 assert( counter <= _insert_limit, "Cycle in hash-table"); 234 } 235 } 236 ShouldNotReachHere(); 237 return false; 238 } 239 240 //------------------------------round_up--------------------------------------- 241 // Round up to nearest power of 2 242 uint NodeHash::round_up( uint x ) { 243 x += (x>>2); // Add 25% slop 244 if( x <16 ) return 16; // Small stuff 245 uint i=16; 246 while( i < x ) i <<= 1; // Double to fit 247 return i; // Return hash table size 248 } 249 250 //------------------------------grow------------------------------------------- 251 // Grow _table to next power of 2 and insert old entries 252 void NodeHash::grow() { 253 // Record old state 254 uint old_max = _max; 255 Node **old_table = _table; 256 // Construct new table with twice the space 257 _grows++; 258 _total_inserts += _inserts; 259 _total_insert_probes += _insert_probes; 260 _inserts = 0; 261 _insert_probes = 0; 262 _max = _max << 1; 263 _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) ); 264 memset(_table,0,sizeof(Node*)*_max); 265 _insert_limit = insert_limit(); 266 // Insert old entries into the new table 267 for( uint i = 0; i < old_max; i++ ) { 268 Node *m = *old_table++; 269 if( !m || m == _sentinel ) continue; 270 debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table. 271 hash_insert(m); 272 } 273 } 274 275 //------------------------------clear------------------------------------------ 276 // Clear all entries in _table to NULL but keep storage 277 void NodeHash::clear() { 278 #ifdef ASSERT 279 // Unlock all nodes upon removal from table. 280 for (uint i = 0; i < _max; i++) { 281 Node* n = _table[i]; 282 if (!n || n == _sentinel) continue; 283 n->exit_hash_lock(); 284 } 285 #endif 286 287 memset( _table, 0, _max * sizeof(Node*) ); 288 } 289 290 //-----------------------remove_useless_nodes---------------------------------- 291 // Remove useless nodes from value table, 292 // implementation does not depend on hash function 293 void NodeHash::remove_useless_nodes(VectorSet &useful) { 294 295 // Dead nodes in the hash table inherited from GVN should not replace 296 // existing nodes, remove dead nodes. 297 uint max = size(); 298 Node *sentinel_node = sentinel(); 299 for( uint i = 0; i < max; ++i ) { 300 Node *n = at(i); 301 if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) { 302 debug_only(n->exit_hash_lock()); // Unlock the node when removed 303 _table[i] = sentinel_node; // Replace with placeholder 304 } 305 } 306 } 307 308 #ifndef PRODUCT 309 //------------------------------dump------------------------------------------- 310 // Dump statistics for the hash table 311 void NodeHash::dump() { 312 _total_inserts += _inserts; 313 _total_insert_probes += _insert_probes; 314 if( PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0) ) { // PrintOptoGVN 315 if( PrintCompilation2 ) { 316 for( uint i=0; i<_max; i++ ) 317 if( _table[i] ) 318 tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx); 319 } 320 tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max); 321 tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0); 322 tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses)); 323 tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts); 324 // sentinels increase lookup cost, but not insert cost 325 assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function"); 326 assert( _inserts+(_inserts>>3) < _max, "table too full" ); 327 assert( _inserts*3+100 >= _insert_probes, "bad hash function" ); 328 } 329 } 330 331 Node *NodeHash::find_index(uint idx) { // For debugging 332 // Find an entry by its index value 333 for( uint i = 0; i < _max; i++ ) { 334 Node *m = _table[i]; 335 if( !m || m == _sentinel ) continue; 336 if( m->_idx == (uint)idx ) return m; 337 } 338 return NULL; 339 } 340 #endif 341 342 #ifdef ASSERT 343 NodeHash::~NodeHash() { 344 // Unlock all nodes upon destruction of table. 345 if (_table != (Node**)badAddress) clear(); 346 } 347 348 void NodeHash::operator=(const NodeHash& nh) { 349 // Unlock all nodes upon replacement of table. 350 if (&nh == this) return; 351 if (_table != (Node**)badAddress) clear(); 352 memcpy(this, &nh, sizeof(*this)); 353 // Do not increment hash_lock counts again. 354 // Instead, be sure we never again use the source table. 355 ((NodeHash*)&nh)->_table = (Node**)badAddress; 356 } 357 358 359 #endif 360 361 362 //============================================================================= 363 //------------------------------PhaseRemoveUseless----------------------------- 364 // 1) Use a breadthfirst walk to collect useful nodes reachable from root. 365 PhaseRemoveUseless::PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ) : Phase(Remove_Useless), 366 _useful(Thread::current()->resource_area()) { 367 368 // Implementation requires 'UseLoopSafepoints == true' and an edge from root 369 // to each SafePointNode at a backward branch. Inserted in add_safepoint(). 370 if( !UseLoopSafepoints || !OptoRemoveUseless ) return; 371 372 // Identify nodes that are reachable from below, useful. 373 C->identify_useful_nodes(_useful); 374 375 // Remove all useless nodes from PhaseValues' recorded types 376 // Must be done before disconnecting nodes to preserve hash-table-invariant 377 gvn->remove_useless_nodes(_useful.member_set()); 378 379 // Remove all useless nodes from future worklist 380 worklist->remove_useless_nodes(_useful.member_set()); 381 382 // Disconnect 'useless' nodes that are adjacent to useful nodes 383 C->remove_useless_nodes(_useful); 384 385 // Remove edges from "root" to each SafePoint at a backward branch. 386 // They were inserted during parsing (see add_safepoint()) to make infinite 387 // loops without calls or exceptions visible to root, i.e., useful. 388 Node *root = C->root(); 389 if( root != NULL ) { 390 for( uint i = root->req(); i < root->len(); ++i ) { 391 Node *n = root->in(i); 392 if( n != NULL && n->is_SafePoint() ) { 393 root->rm_prec(i); 394 --i; 395 } 396 } 397 } 398 } 399 400 401 //============================================================================= 402 //------------------------------PhaseTransform--------------------------------- 403 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum), 404 _arena(Thread::current()->resource_area()), 405 _nodes(_arena), 406 _types(_arena) 407 { 408 init_con_caches(); 409 #ifndef PRODUCT 410 clear_progress(); 411 clear_transforms(); 412 set_allow_progress(true); 413 #endif 414 // Force allocation for currently existing nodes 415 _types.map(C->unique(), NULL); 416 } 417 418 //------------------------------PhaseTransform--------------------------------- 419 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum), 420 _arena(arena), 421 _nodes(arena), 422 _types(arena) 423 { 424 init_con_caches(); 425 #ifndef PRODUCT 426 clear_progress(); 427 clear_transforms(); 428 set_allow_progress(true); 429 #endif 430 // Force allocation for currently existing nodes 431 _types.map(C->unique(), NULL); 432 } 433 434 //------------------------------PhaseTransform--------------------------------- 435 // Initialize with previously generated type information 436 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum), 437 _arena(pt->_arena), 438 _nodes(pt->_nodes), 439 _types(pt->_types) 440 { 441 init_con_caches(); 442 #ifndef PRODUCT 443 clear_progress(); 444 clear_transforms(); 445 set_allow_progress(true); 446 #endif 447 } 448 449 void PhaseTransform::init_con_caches() { 450 memset(_icons,0,sizeof(_icons)); 451 memset(_lcons,0,sizeof(_lcons)); 452 memset(_zcons,0,sizeof(_zcons)); 453 } 454 455 456 //--------------------------------find_int_type-------------------------------- 457 const TypeInt* PhaseTransform::find_int_type(Node* n) { 458 if (n == NULL) return NULL; 459 // Call type_or_null(n) to determine node's type since we might be in 460 // parse phase and call n->Value() may return wrong type. 461 // (For example, a phi node at the beginning of loop parsing is not ready.) 462 const Type* t = type_or_null(n); 463 if (t == NULL) return NULL; 464 return t->isa_int(); 465 } 466 467 468 //-------------------------------find_long_type-------------------------------- 469 const TypeLong* PhaseTransform::find_long_type(Node* n) { 470 if (n == NULL) return NULL; 471 // (See comment above on type_or_null.) 472 const Type* t = type_or_null(n); 473 if (t == NULL) return NULL; 474 return t->isa_long(); 475 } 476 477 478 #ifndef PRODUCT 479 void PhaseTransform::dump_old2new_map() const { 480 _nodes.dump(); 481 } 482 483 void PhaseTransform::dump_new( uint nidx ) const { 484 for( uint i=0; i<_nodes.Size(); i++ ) 485 if( _nodes[i] && _nodes[i]->_idx == nidx ) { 486 _nodes[i]->dump(); 487 tty->cr(); 488 tty->print_cr("Old index= %d",i); 489 return; 490 } 491 tty->print_cr("Node %d not found in the new indices", nidx); 492 } 493 494 //------------------------------dump_types------------------------------------- 495 void PhaseTransform::dump_types( ) const { 496 _types.dump(); 497 } 498 499 //------------------------------dump_nodes_and_types--------------------------- 500 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) { 501 VectorSet visited(Thread::current()->resource_area()); 502 dump_nodes_and_types_recur( root, depth, only_ctrl, visited ); 503 } 504 505 //------------------------------dump_nodes_and_types_recur--------------------- 506 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) { 507 if( !n ) return; 508 if( depth == 0 ) return; 509 if( visited.test_set(n->_idx) ) return; 510 for( uint i=0; i<n->len(); i++ ) { 511 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue; 512 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited ); 513 } 514 n->dump(); 515 if (type_or_null(n) != NULL) { 516 tty->print(" "); type(n)->dump(); tty->cr(); 517 } 518 } 519 520 #endif 521 522 523 //============================================================================= 524 //------------------------------PhaseValues------------------------------------ 525 // Set minimum table size to "255" 526 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) { 527 NOT_PRODUCT( clear_new_values(); ) 528 } 529 530 //------------------------------PhaseValues------------------------------------ 531 // Set minimum table size to "255" 532 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ), 533 _table(&ptv->_table) { 534 NOT_PRODUCT( clear_new_values(); ) 535 } 536 537 //------------------------------PhaseValues------------------------------------ 538 // Used by +VerifyOpto. Clear out hash table but copy _types array. 539 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ), 540 _table(ptv->arena(),ptv->_table.size()) { 541 NOT_PRODUCT( clear_new_values(); ) 542 } 543 544 //------------------------------~PhaseValues----------------------------------- 545 #ifndef PRODUCT 546 PhaseValues::~PhaseValues() { 547 _table.dump(); 548 549 // Statistics for value progress and efficiency 550 if( PrintCompilation && Verbose && WizardMode ) { 551 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)", 552 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values()); 553 if( made_transforms() != 0 ) { 554 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() ); 555 } else { 556 tty->cr(); 557 } 558 } 559 } 560 #endif 561 562 //------------------------------makecon---------------------------------------- 563 ConNode* PhaseTransform::makecon(const Type *t) { 564 assert(t->singleton(), "must be a constant"); 565 assert(!t->empty() || t == Type::TOP, "must not be vacuous range"); 566 switch (t->base()) { // fast paths 567 case Type::Half: 568 case Type::Top: return (ConNode*) C->top(); 569 case Type::Int: return intcon( t->is_int()->get_con() ); 570 case Type::Long: return longcon( t->is_long()->get_con() ); 571 } 572 if (t->is_zero_type()) 573 return zerocon(t->basic_type()); 574 return uncached_makecon(t); 575 } 576 577 //--------------------------uncached_makecon----------------------------------- 578 // Make an idealized constant - one of ConINode, ConPNode, etc. 579 ConNode* PhaseValues::uncached_makecon(const Type *t) { 580 assert(t->singleton(), "must be a constant"); 581 ConNode* x = ConNode::make(C, t); 582 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering 583 if (k == NULL) { 584 set_type(x, t); // Missed, provide type mapping 585 GrowableArray<Node_Notes*>* nna = C->node_note_array(); 586 if (nna != NULL) { 587 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true); 588 loc->clear(); // do not put debug info on constants 589 } 590 } else { 591 x->destruct(); // Hit, destroy duplicate constant 592 x = k; // use existing constant 593 } 594 return x; 595 } 596 597 //------------------------------intcon----------------------------------------- 598 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))" 599 ConINode* PhaseTransform::intcon(int i) { 600 // Small integer? Check cache! Check that cached node is not dead 601 if (i >= _icon_min && i <= _icon_max) { 602 ConINode* icon = _icons[i-_icon_min]; 603 if (icon != NULL && icon->in(TypeFunc::Control) != NULL) 604 return icon; 605 } 606 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i)); 607 assert(icon->is_Con(), ""); 608 if (i >= _icon_min && i <= _icon_max) 609 _icons[i-_icon_min] = icon; // Cache small integers 610 return icon; 611 } 612 613 //------------------------------longcon---------------------------------------- 614 // Fast long constant. 615 ConLNode* PhaseTransform::longcon(jlong l) { 616 // Small integer? Check cache! Check that cached node is not dead 617 if (l >= _lcon_min && l <= _lcon_max) { 618 ConLNode* lcon = _lcons[l-_lcon_min]; 619 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL) 620 return lcon; 621 } 622 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l)); 623 assert(lcon->is_Con(), ""); 624 if (l >= _lcon_min && l <= _lcon_max) 625 _lcons[l-_lcon_min] = lcon; // Cache small integers 626 return lcon; 627 } 628 629 //------------------------------zerocon----------------------------------------- 630 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))" 631 ConNode* PhaseTransform::zerocon(BasicType bt) { 632 assert((uint)bt <= _zcon_max, "domain check"); 633 ConNode* zcon = _zcons[bt]; 634 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL) 635 return zcon; 636 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt)); 637 _zcons[bt] = zcon; 638 return zcon; 639 } 640 641 642 643 //============================================================================= 644 //------------------------------transform-------------------------------------- 645 // Return a node which computes the same function as this node, but in a 646 // faster or cheaper fashion. 647 Node *PhaseGVN::transform( Node *n ) { 648 return transform_no_reclaim(n); 649 } 650 651 //------------------------------transform-------------------------------------- 652 // Return a node which computes the same function as this node, but 653 // in a faster or cheaper fashion. 654 Node *PhaseGVN::transform_no_reclaim( Node *n ) { 655 NOT_PRODUCT( set_transforms(); ) 656 657 // Apply the Ideal call in a loop until it no longer applies 658 Node *k = n; 659 NOT_PRODUCT( uint loop_count = 0; ) 660 while( 1 ) { 661 Node *i = k->Ideal(this, /*can_reshape=*/false); 662 if( !i ) break; 663 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" ); 664 k = i; 665 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform"); 666 } 667 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } ) 668 669 670 // If brand new node, make space in type array. 671 ensure_type_or_null(k); 672 673 // Since I just called 'Value' to compute the set of run-time values 674 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 675 // cache Value. Later requests for the local phase->type of this Node can 676 // use the cached Value instead of suffering with 'bottom_type'. 677 const Type *t = k->Value(this); // Get runtime Value set 678 assert(t != NULL, "value sanity"); 679 if (type_or_null(k) != t) { 680 #ifndef PRODUCT 681 // Do not count initial visit to node as a transformation 682 if (type_or_null(k) == NULL) { 683 inc_new_values(); 684 set_progress(); 685 } 686 #endif 687 set_type(k, t); 688 // If k is a TypeNode, capture any more-precise type permanently into Node 689 k->raise_bottom_type(t); 690 } 691 692 if( t->singleton() && !k->is_Con() ) { 693 NOT_PRODUCT( set_progress(); ) 694 return makecon(t); // Turn into a constant 695 } 696 697 // Now check for Identities 698 Node *i = k->Identity(this); // Look for a nearby replacement 699 if( i != k ) { // Found? Return replacement! 700 NOT_PRODUCT( set_progress(); ) 701 return i; 702 } 703 704 // Global Value Numbering 705 i = hash_find_insert(k); // Insert if new 706 if( i && (i != k) ) { 707 // Return the pre-existing node 708 NOT_PRODUCT( set_progress(); ) 709 return i; 710 } 711 712 // Return Idealized original 713 return k; 714 } 715 716 #ifdef ASSERT 717 //------------------------------dead_loop_check-------------------------------- 718 // Check for a simple dead loop when a data node references itself directly 719 // or through an other data node excluding cons and phis. 720 void PhaseGVN::dead_loop_check( Node *n ) { 721 // Phi may reference itself in a loop 722 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) { 723 // Do 2 levels check and only data inputs. 724 bool no_dead_loop = true; 725 uint cnt = n->req(); 726 for (uint i = 1; i < cnt && no_dead_loop; i++) { 727 Node *in = n->in(i); 728 if (in == n) { 729 no_dead_loop = false; 730 } else if (in != NULL && !in->is_dead_loop_safe()) { 731 uint icnt = in->req(); 732 for (uint j = 1; j < icnt && no_dead_loop; j++) { 733 if (in->in(j) == n || in->in(j) == in) 734 no_dead_loop = false; 735 } 736 } 737 } 738 if (!no_dead_loop) n->dump(3); 739 assert(no_dead_loop, "dead loop detected"); 740 } 741 } 742 #endif 743 744 //============================================================================= 745 //------------------------------PhaseIterGVN----------------------------------- 746 // Initialize hash table to fresh and clean for +VerifyOpto 747 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ), 748 _delay_transform(false) { 749 } 750 751 //------------------------------PhaseIterGVN----------------------------------- 752 // Initialize with previous PhaseIterGVN info; used by PhaseCCP 753 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn), 754 _worklist( igvn->_worklist ), 755 _delay_transform(igvn->_delay_transform) 756 { 757 } 758 759 //------------------------------PhaseIterGVN----------------------------------- 760 // Initialize with previous PhaseGVN info from Parser 761 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn), 762 _worklist(*C->for_igvn()), 763 _delay_transform(false) 764 { 765 uint max; 766 767 // Dead nodes in the hash table inherited from GVN were not treated as 768 // roots during def-use info creation; hence they represent an invisible 769 // use. Clear them out. 770 max = _table.size(); 771 for( uint i = 0; i < max; ++i ) { 772 Node *n = _table.at(i); 773 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) { 774 if( n->is_top() ) continue; 775 assert( false, "Parse::remove_useless_nodes missed this node"); 776 hash_delete(n); 777 } 778 } 779 780 // Any Phis or Regions on the worklist probably had uses that could not 781 // make more progress because the uses were made while the Phis and Regions 782 // were in half-built states. Put all uses of Phis and Regions on worklist. 783 max = _worklist.size(); 784 for( uint j = 0; j < max; j++ ) { 785 Node *n = _worklist.at(j); 786 uint uop = n->Opcode(); 787 if( uop == Op_Phi || uop == Op_Region || 788 n->is_Type() || 789 n->is_Mem() ) 790 add_users_to_worklist(n); 791 } 792 } 793 794 795 #ifndef PRODUCT 796 void PhaseIterGVN::verify_step(Node* n) { 797 _verify_window[_verify_counter % _verify_window_size] = n; 798 ++_verify_counter; 799 ResourceMark rm; 800 ResourceArea *area = Thread::current()->resource_area(); 801 VectorSet old_space(area), new_space(area); 802 if (C->unique() < 1000 || 803 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) { 804 ++_verify_full_passes; 805 Node::verify_recur(C->root(), -1, old_space, new_space); 806 } 807 const int verify_depth = 4; 808 for ( int i = 0; i < _verify_window_size; i++ ) { 809 Node* n = _verify_window[i]; 810 if ( n == NULL ) continue; 811 if( n->in(0) == NodeSentinel ) { // xform_idom 812 _verify_window[i] = n->in(1); 813 --i; continue; 814 } 815 // Typical fanout is 1-2, so this call visits about 6 nodes. 816 Node::verify_recur(n, verify_depth, old_space, new_space); 817 } 818 } 819 #endif 820 821 822 //------------------------------init_worklist---------------------------------- 823 // Initialize worklist for each node. 824 void PhaseIterGVN::init_worklist( Node *n ) { 825 if( _worklist.member(n) ) return; 826 _worklist.push(n); 827 uint cnt = n->req(); 828 for( uint i =0 ; i < cnt; i++ ) { 829 Node *m = n->in(i); 830 if( m ) init_worklist(m); 831 } 832 } 833 834 //------------------------------optimize--------------------------------------- 835 void PhaseIterGVN::optimize() { 836 debug_only(uint num_processed = 0;); 837 #ifndef PRODUCT 838 { 839 _verify_counter = 0; 840 _verify_full_passes = 0; 841 for ( int i = 0; i < _verify_window_size; i++ ) { 842 _verify_window[i] = NULL; 843 } 844 } 845 #endif 846 847 #ifdef ASSERT 848 Node* prev = NULL; 849 uint rep_cnt = 0; 850 #endif 851 uint loop_count = 0; 852 853 // Pull from worklist; transform node; 854 // If node has changed: update edge info and put uses on worklist. 855 while( _worklist.size() ) { 856 Node *n = _worklist.pop(); 857 if (++loop_count >= K * C->unique()) { 858 debug_only(n->dump(4);) 859 assert(false, "infinite loop in PhaseIterGVN::optimize"); 860 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize"); 861 return; 862 } 863 #ifdef ASSERT 864 if (n == prev) { 865 if (++rep_cnt > 3) { 866 n->dump(4); 867 assert(false, "loop in Ideal transformation"); 868 } 869 } else { 870 rep_cnt = 0; 871 } 872 prev = n; 873 #endif 874 if (TraceIterativeGVN && Verbose) { 875 tty->print(" Pop "); 876 NOT_PRODUCT( n->dump(); ) 877 debug_only(if( (num_processed++ % 100) == 0 ) _worklist.print_set();) 878 } 879 880 if (n->outcnt() != 0) { 881 882 #ifndef PRODUCT 883 uint wlsize = _worklist.size(); 884 const Type* oldtype = type_or_null(n); 885 #endif //PRODUCT 886 887 Node *nn = transform_old(n); 888 889 #ifndef PRODUCT 890 if (TraceIterativeGVN) { 891 const Type* newtype = type_or_null(n); 892 if (nn != n) { 893 // print old node 894 tty->print("< "); 895 if (oldtype != newtype && oldtype != NULL) { 896 oldtype->dump(); 897 } 898 do { tty->print("\t"); } while (tty->position() < 16); 899 tty->print("<"); 900 n->dump(); 901 } 902 if (oldtype != newtype || nn != n) { 903 // print new node and/or new type 904 if (oldtype == NULL) { 905 tty->print("* "); 906 } else if (nn != n) { 907 tty->print("> "); 908 } else { 909 tty->print("= "); 910 } 911 if (newtype == NULL) { 912 tty->print("null"); 913 } else { 914 newtype->dump(); 915 } 916 do { tty->print("\t"); } while (tty->position() < 16); 917 nn->dump(); 918 } 919 if (Verbose && wlsize < _worklist.size()) { 920 tty->print(" Push {"); 921 while (wlsize != _worklist.size()) { 922 Node* pushed = _worklist.at(wlsize++); 923 tty->print(" %d", pushed->_idx); 924 } 925 tty->print_cr(" }"); 926 } 927 } 928 if( VerifyIterativeGVN && nn != n ) { 929 verify_step((Node*) NULL); // ignore n, it might be subsumed 930 } 931 #endif 932 } else if (!n->is_top()) { 933 remove_dead_node(n); 934 } 935 } 936 937 #ifndef PRODUCT 938 C->verify_graph_edges(); 939 if( VerifyOpto && allow_progress() ) { 940 // Must turn off allow_progress to enable assert and break recursion 941 C->root()->verify(); 942 { // Check if any progress was missed using IterGVN 943 // Def-Use info enables transformations not attempted in wash-pass 944 // e.g. Region/Phi cleanup, ... 945 // Null-check elision -- may not have reached fixpoint 946 // do not propagate to dominated nodes 947 ResourceMark rm; 948 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean! 949 // Fill worklist completely 950 igvn2.init_worklist(C->root()); 951 952 igvn2.set_allow_progress(false); 953 igvn2.optimize(); 954 igvn2.set_allow_progress(true); 955 } 956 } 957 if ( VerifyIterativeGVN && PrintOpto ) { 958 if ( _verify_counter == _verify_full_passes ) 959 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes", 960 _verify_full_passes); 961 else 962 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes", 963 _verify_counter, _verify_full_passes); 964 } 965 #endif 966 } 967 968 969 //------------------register_new_node_with_optimizer--------------------------- 970 // Register a new node with the optimizer. Update the types array, the def-use 971 // info. Put on worklist. 972 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) { 973 set_type_bottom(n); 974 _worklist.push(n); 975 if (orig != NULL) C->copy_node_notes_to(n, orig); 976 return n; 977 } 978 979 //------------------------------transform-------------------------------------- 980 // Non-recursive: idealize Node 'n' with respect to its inputs and its value 981 Node *PhaseIterGVN::transform( Node *n ) { 982 if (_delay_transform) { 983 // Register the node but don't optimize for now 984 register_new_node_with_optimizer(n); 985 return n; 986 } 987 988 // If brand new node, make space in type array, and give it a type. 989 ensure_type_or_null(n); 990 if (type_or_null(n) == NULL) { 991 set_type_bottom(n); 992 } 993 994 return transform_old(n); 995 } 996 997 //------------------------------transform_old---------------------------------- 998 Node *PhaseIterGVN::transform_old( Node *n ) { 999 #ifndef PRODUCT 1000 debug_only(uint loop_count = 0;); 1001 set_transforms(); 1002 #endif 1003 // Remove 'n' from hash table in case it gets modified 1004 _table.hash_delete(n); 1005 if( VerifyIterativeGVN ) { 1006 assert( !_table.find_index(n->_idx), "found duplicate entry in table"); 1007 } 1008 1009 // Apply the Ideal call in a loop until it no longer applies 1010 Node *k = n; 1011 DEBUG_ONLY(dead_loop_check(k);) 1012 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);) 1013 Node *i = k->Ideal(this, /*can_reshape=*/true); 1014 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1015 #ifndef PRODUCT 1016 if( VerifyIterativeGVN ) 1017 verify_step(k); 1018 if( i && VerifyOpto ) { 1019 if( !allow_progress() ) { 1020 if (i->is_Add() && i->outcnt() == 1) { 1021 // Switched input to left side because this is the only use 1022 } else if( i->is_If() && (i->in(0) == NULL) ) { 1023 // This IF is dead because it is dominated by an equivalent IF When 1024 // dominating if changed, info is not propagated sparsely to 'this' 1025 // Propagating this info further will spuriously identify other 1026 // progress. 1027 return i; 1028 } else 1029 set_progress(); 1030 } else 1031 set_progress(); 1032 } 1033 #endif 1034 1035 while( i ) { 1036 #ifndef PRODUCT 1037 debug_only( if( loop_count >= K ) i->dump(4); ) 1038 assert(loop_count < K, "infinite loop in PhaseIterGVN::transform"); 1039 debug_only( loop_count++; ) 1040 #endif 1041 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes"); 1042 // Made a change; put users of original Node on worklist 1043 add_users_to_worklist( k ); 1044 // Replacing root of transform tree? 1045 if( k != i ) { 1046 // Make users of old Node now use new. 1047 subsume_node( k, i ); 1048 k = i; 1049 } 1050 DEBUG_ONLY(dead_loop_check(k);) 1051 // Try idealizing again 1052 DEBUG_ONLY(is_new = (k->outcnt() == 0);) 1053 i = k->Ideal(this, /*can_reshape=*/true); 1054 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes"); 1055 #ifndef PRODUCT 1056 if( VerifyIterativeGVN ) 1057 verify_step(k); 1058 if( i && VerifyOpto ) set_progress(); 1059 #endif 1060 } 1061 1062 // If brand new node, make space in type array. 1063 ensure_type_or_null(k); 1064 1065 // See what kind of values 'k' takes on at runtime 1066 const Type *t = k->Value(this); 1067 assert(t != NULL, "value sanity"); 1068 1069 // Since I just called 'Value' to compute the set of run-time values 1070 // for this Node, and 'Value' is non-local (and therefore expensive) I'll 1071 // cache Value. Later requests for the local phase->type of this Node can 1072 // use the cached Value instead of suffering with 'bottom_type'. 1073 if (t != type_or_null(k)) { 1074 NOT_PRODUCT( set_progress(); ) 1075 NOT_PRODUCT( inc_new_values();) 1076 set_type(k, t); 1077 // If k is a TypeNode, capture any more-precise type permanently into Node 1078 k->raise_bottom_type(t); 1079 // Move users of node to worklist 1080 add_users_to_worklist( k ); 1081 } 1082 1083 // If 'k' computes a constant, replace it with a constant 1084 if( t->singleton() && !k->is_Con() ) { 1085 NOT_PRODUCT( set_progress(); ) 1086 Node *con = makecon(t); // Make a constant 1087 add_users_to_worklist( k ); 1088 subsume_node( k, con ); // Everybody using k now uses con 1089 return con; 1090 } 1091 1092 // Now check for Identities 1093 i = k->Identity(this); // Look for a nearby replacement 1094 if( i != k ) { // Found? Return replacement! 1095 NOT_PRODUCT( set_progress(); ) 1096 add_users_to_worklist( k ); 1097 subsume_node( k, i ); // Everybody using k now uses i 1098 return i; 1099 } 1100 1101 // Global Value Numbering 1102 i = hash_find_insert(k); // Check for pre-existing node 1103 if( i && (i != k) ) { 1104 // Return the pre-existing node if it isn't dead 1105 NOT_PRODUCT( set_progress(); ) 1106 add_users_to_worklist( k ); 1107 subsume_node( k, i ); // Everybody using k now uses i 1108 return i; 1109 } 1110 1111 // Return Idealized original 1112 return k; 1113 } 1114 1115 //---------------------------------saturate------------------------------------ 1116 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type, 1117 const Type* limit_type) const { 1118 return new_type->narrow(old_type); 1119 } 1120 1121 //------------------------------remove_globally_dead_node---------------------- 1122 // Kill a globally dead Node. All uses are also globally dead and are 1123 // aggressively trimmed. 1124 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) { 1125 assert(dead != C->root(), "killing root, eh?"); 1126 if (dead->is_top()) return; 1127 NOT_PRODUCT( set_progress(); ) 1128 // Remove from iterative worklist 1129 _worklist.remove(dead); 1130 if (!dead->is_Con()) { // Don't kill cons but uses 1131 // Remove from hash table 1132 _table.hash_delete( dead ); 1133 // Smash all inputs to 'dead', isolating him completely 1134 for( uint i = 0; i < dead->req(); i++ ) { 1135 Node *in = dead->in(i); 1136 if( in ) { // Points to something? 1137 dead->set_req(i,NULL); // Kill the edge 1138 if (in->outcnt() == 0 && in != C->top()) {// Made input go dead? 1139 remove_dead_node(in); // Recursively remove 1140 } else if (in->outcnt() == 1 && 1141 in->has_special_unique_user()) { 1142 _worklist.push(in->unique_out()); 1143 } else if (in->outcnt() <= 2 && dead->is_Phi()) { 1144 if( in->Opcode() == Op_Region ) 1145 _worklist.push(in); 1146 else if( in->is_Store() ) { 1147 DUIterator_Fast imax, i = in->fast_outs(imax); 1148 _worklist.push(in->fast_out(i)); 1149 i++; 1150 if(in->outcnt() == 2) { 1151 _worklist.push(in->fast_out(i)); 1152 i++; 1153 } 1154 assert(!(i < imax), "sanity"); 1155 } 1156 } 1157 } 1158 } 1159 1160 if (dead->is_macro()) { 1161 C->remove_macro_node(dead); 1162 } 1163 } 1164 // Aggressively kill globally dead uses 1165 // (Cannot use DUIterator_Last because of the indefinite number 1166 // of edge deletions per loop trip.) 1167 while (dead->outcnt() > 0) { 1168 remove_globally_dead_node(dead->raw_out(0)); 1169 } 1170 } 1171 1172 //------------------------------subsume_node----------------------------------- 1173 // Remove users from node 'old' and add them to node 'nn'. 1174 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) { 1175 assert( old != hash_find(old), "should already been removed" ); 1176 assert( old != C->top(), "cannot subsume top node"); 1177 // Copy debug or profile information to the new version: 1178 C->copy_node_notes_to(nn, old); 1179 // Move users of node 'old' to node 'nn' 1180 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) { 1181 Node* use = old->last_out(i); // for each use... 1182 // use might need re-hashing (but it won't if it's a new node) 1183 bool is_in_table = _table.hash_delete( use ); 1184 // Update use-def info as well 1185 // We remove all occurrences of old within use->in, 1186 // so as to avoid rehashing any node more than once. 1187 // The hash table probe swamps any outer loop overhead. 1188 uint num_edges = 0; 1189 for (uint jmax = use->len(), j = 0; j < jmax; j++) { 1190 if (use->in(j) == old) { 1191 use->set_req(j, nn); 1192 ++num_edges; 1193 } 1194 } 1195 // Insert into GVN hash table if unique 1196 // If a duplicate, 'use' will be cleaned up when pulled off worklist 1197 if( is_in_table ) { 1198 hash_find_insert(use); 1199 } 1200 i -= num_edges; // we deleted 1 or more copies of this edge 1201 } 1202 1203 // Smash all inputs to 'old', isolating him completely 1204 Node *temp = new (C, 1) Node(1); 1205 temp->init_req(0,nn); // Add a use to nn to prevent him from dying 1206 remove_dead_node( old ); 1207 temp->del_req(0); // Yank bogus edge 1208 #ifndef PRODUCT 1209 if( VerifyIterativeGVN ) { 1210 for ( int i = 0; i < _verify_window_size; i++ ) { 1211 if ( _verify_window[i] == old ) 1212 _verify_window[i] = nn; 1213 } 1214 } 1215 #endif 1216 _worklist.remove(temp); // this can be necessary 1217 temp->destruct(); // reuse the _idx of this little guy 1218 } 1219 1220 //------------------------------add_users_to_worklist-------------------------- 1221 void PhaseIterGVN::add_users_to_worklist0( Node *n ) { 1222 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1223 _worklist.push(n->fast_out(i)); // Push on worklist 1224 } 1225 } 1226 1227 void PhaseIterGVN::add_users_to_worklist( Node *n ) { 1228 add_users_to_worklist0(n); 1229 1230 // Move users of node to worklist 1231 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1232 Node* use = n->fast_out(i); // Get use 1233 1234 if( use->is_Multi() || // Multi-definer? Push projs on worklist 1235 use->is_Store() ) // Enable store/load same address 1236 add_users_to_worklist0(use); 1237 1238 // If we changed the receiver type to a call, we need to revisit 1239 // the Catch following the call. It's looking for a non-NULL 1240 // receiver to know when to enable the regular fall-through path 1241 // in addition to the NullPtrException path. 1242 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) { 1243 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control); 1244 if (p != NULL) { 1245 add_users_to_worklist0(p); 1246 } 1247 } 1248 1249 if( use->is_Cmp() ) { // Enable CMP/BOOL optimization 1250 add_users_to_worklist(use); // Put Bool on worklist 1251 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the 1252 // phi merging either 0 or 1 onto the worklist 1253 if (use->outcnt() > 0) { 1254 Node* bol = use->raw_out(0); 1255 if (bol->outcnt() > 0) { 1256 Node* iff = bol->raw_out(0); 1257 if (iff->outcnt() == 2) { 1258 Node* ifproj0 = iff->raw_out(0); 1259 Node* ifproj1 = iff->raw_out(1); 1260 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) { 1261 Node* region0 = ifproj0->raw_out(0); 1262 Node* region1 = ifproj1->raw_out(0); 1263 if( region0 == region1 ) 1264 add_users_to_worklist0(region0); 1265 } 1266 } 1267 } 1268 } 1269 } 1270 1271 uint use_op = use->Opcode(); 1272 // If changed Cast input, check Phi users for simple cycles 1273 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) { 1274 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1275 Node* u = use->fast_out(i2); 1276 if (u->is_Phi()) 1277 _worklist.push(u); 1278 } 1279 } 1280 // If changed LShift inputs, check RShift users for useless sign-ext 1281 if( use_op == Op_LShiftI ) { 1282 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1283 Node* u = use->fast_out(i2); 1284 if (u->Opcode() == Op_RShiftI) 1285 _worklist.push(u); 1286 } 1287 } 1288 // If changed AddP inputs, check Stores for loop invariant 1289 if( use_op == Op_AddP ) { 1290 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) { 1291 Node* u = use->fast_out(i2); 1292 if (u->is_Mem()) 1293 _worklist.push(u); 1294 } 1295 } 1296 // If changed initialization activity, check dependent Stores 1297 if (use_op == Op_Allocate || use_op == Op_AllocateArray) { 1298 InitializeNode* init = use->as_Allocate()->initialization(); 1299 if (init != NULL) { 1300 Node* imem = init->proj_out(TypeFunc::Memory); 1301 if (imem != NULL) add_users_to_worklist0(imem); 1302 } 1303 } 1304 if (use_op == Op_Initialize) { 1305 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory); 1306 if (imem != NULL) add_users_to_worklist0(imem); 1307 } 1308 } 1309 } 1310 1311 //============================================================================= 1312 #ifndef PRODUCT 1313 uint PhaseCCP::_total_invokes = 0; 1314 uint PhaseCCP::_total_constants = 0; 1315 #endif 1316 //------------------------------PhaseCCP--------------------------------------- 1317 // Conditional Constant Propagation, ala Wegman & Zadeck 1318 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) { 1319 NOT_PRODUCT( clear_constants(); ) 1320 assert( _worklist.size() == 0, "" ); 1321 // Clear out _nodes from IterGVN. Must be clear to transform call. 1322 _nodes.clear(); // Clear out from IterGVN 1323 analyze(); 1324 } 1325 1326 #ifndef PRODUCT 1327 //------------------------------~PhaseCCP-------------------------------------- 1328 PhaseCCP::~PhaseCCP() { 1329 inc_invokes(); 1330 _total_constants += count_constants(); 1331 } 1332 #endif 1333 1334 1335 #ifdef ASSERT 1336 static bool ccp_type_widens(const Type* t, const Type* t0) { 1337 assert(t->meet(t0) == t, "Not monotonic"); 1338 switch (t->base() == t0->base() ? t->base() : Type::Top) { 1339 case Type::Int: 1340 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases"); 1341 break; 1342 case Type::Long: 1343 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases"); 1344 break; 1345 } 1346 return true; 1347 } 1348 #endif //ASSERT 1349 1350 //------------------------------analyze---------------------------------------- 1351 void PhaseCCP::analyze() { 1352 // Initialize all types to TOP, optimistic analysis 1353 for (int i = C->unique() - 1; i >= 0; i--) { 1354 _types.map(i,Type::TOP); 1355 } 1356 1357 // Push root onto worklist 1358 Unique_Node_List worklist; 1359 worklist.push(C->root()); 1360 1361 // Pull from worklist; compute new value; push changes out. 1362 // This loop is the meat of CCP. 1363 while( worklist.size() ) { 1364 Node *n = worklist.pop(); 1365 const Type *t = n->Value(this); 1366 if (t != type(n)) { 1367 assert(ccp_type_widens(t, type(n)), "ccp type must widen"); 1368 #ifndef PRODUCT 1369 if( TracePhaseCCP ) { 1370 t->dump(); 1371 do { tty->print("\t"); } while (tty->position() < 16); 1372 n->dump(); 1373 } 1374 #endif 1375 set_type(n, t); 1376 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1377 Node* m = n->fast_out(i); // Get user 1378 if( m->is_Region() ) { // New path to Region? Must recheck Phis too 1379 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1380 Node* p = m->fast_out(i2); // Propagate changes to uses 1381 if( p->bottom_type() != type(p) ) // If not already bottomed out 1382 worklist.push(p); // Propagate change to user 1383 } 1384 } 1385 // If we changed the receiver type to a call, we need to revisit 1386 // the Catch following the call. It's looking for a non-NULL 1387 // receiver to know when to enable the regular fall-through path 1388 // in addition to the NullPtrException path 1389 if (m->is_Call()) { 1390 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) { 1391 Node* p = m->fast_out(i2); // Propagate changes to uses 1392 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) 1393 worklist.push(p->unique_out()); 1394 } 1395 } 1396 if( m->bottom_type() != type(m) ) // If not already bottomed out 1397 worklist.push(m); // Propagate change to user 1398 } 1399 } 1400 } 1401 } 1402 1403 //------------------------------do_transform----------------------------------- 1404 // Top level driver for the recursive transformer 1405 void PhaseCCP::do_transform() { 1406 // Correct leaves of new-space Nodes; they point to old-space. 1407 C->set_root( transform(C->root())->as_Root() ); 1408 assert( C->top(), "missing TOP node" ); 1409 assert( C->root(), "missing root" ); 1410 } 1411 1412 //------------------------------transform-------------------------------------- 1413 // Given a Node in old-space, clone him into new-space. 1414 // Convert any of his old-space children into new-space children. 1415 Node *PhaseCCP::transform( Node *n ) { 1416 Node *new_node = _nodes[n->_idx]; // Check for transformed node 1417 if( new_node != NULL ) 1418 return new_node; // Been there, done that, return old answer 1419 new_node = transform_once(n); // Check for constant 1420 _nodes.map( n->_idx, new_node ); // Flag as having been cloned 1421 1422 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc 1423 GrowableArray <Node *> trstack(C->unique() >> 1); 1424 1425 trstack.push(new_node); // Process children of cloned node 1426 while ( trstack.is_nonempty() ) { 1427 Node *clone = trstack.pop(); 1428 uint cnt = clone->req(); 1429 for( uint i = 0; i < cnt; i++ ) { // For all inputs do 1430 Node *input = clone->in(i); 1431 if( input != NULL ) { // Ignore NULLs 1432 Node *new_input = _nodes[input->_idx]; // Check for cloned input node 1433 if( new_input == NULL ) { 1434 new_input = transform_once(input); // Check for constant 1435 _nodes.map( input->_idx, new_input );// Flag as having been cloned 1436 trstack.push(new_input); 1437 } 1438 assert( new_input == clone->in(i), "insanity check"); 1439 } 1440 } 1441 } 1442 return new_node; 1443 } 1444 1445 1446 //------------------------------transform_once--------------------------------- 1447 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant. 1448 Node *PhaseCCP::transform_once( Node *n ) { 1449 const Type *t = type(n); 1450 // Constant? Use constant Node instead 1451 if( t->singleton() ) { 1452 Node *nn = n; // Default is to return the original constant 1453 if( t == Type::TOP ) { 1454 // cache my top node on the Compile instance 1455 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) { 1456 C->set_cached_top_node( ConNode::make(C, Type::TOP) ); 1457 set_type(C->top(), Type::TOP); 1458 } 1459 nn = C->top(); 1460 } 1461 if( !n->is_Con() ) { 1462 if( t != Type::TOP ) { 1463 nn = makecon(t); // ConNode::make(t); 1464 NOT_PRODUCT( inc_constants(); ) 1465 } else if( n->is_Region() ) { // Unreachable region 1466 // Note: nn == C->top() 1467 n->set_req(0, NULL); // Cut selfreference 1468 // Eagerly remove dead phis to avoid phis copies creation. 1469 for (DUIterator i = n->outs(); n->has_out(i); i++) { 1470 Node* m = n->out(i); 1471 if( m->is_Phi() ) { 1472 assert(type(m) == Type::TOP, "Unreachable region should not have live phis."); 1473 replace_node(m, nn); 1474 --i; // deleted this phi; rescan starting with next position 1475 } 1476 } 1477 } 1478 replace_node(n,nn); // Update DefUse edges for new constant 1479 } 1480 return nn; 1481 } 1482 1483 // If x is a TypeNode, capture any more-precise type permanently into Node 1484 if (t != n->bottom_type()) { 1485 hash_delete(n); // changing bottom type may force a rehash 1486 n->raise_bottom_type(t); 1487 _worklist.push(n); // n re-enters the hash table via the worklist 1488 } 1489 1490 // Idealize graph using DU info. Must clone() into new-space. 1491 // DU info is generally used to show profitability, progress or safety 1492 // (but generally not needed for correctness). 1493 Node *nn = n->Ideal_DU_postCCP(this); 1494 1495 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks 1496 switch( n->Opcode() ) { 1497 case Op_FastLock: // Revisit FastLocks for lock coarsening 1498 case Op_If: 1499 case Op_CountedLoopEnd: 1500 case Op_Region: 1501 case Op_Loop: 1502 case Op_CountedLoop: 1503 case Op_Conv2B: 1504 case Op_Opaque1: 1505 case Op_Opaque2: 1506 _worklist.push(n); 1507 break; 1508 default: 1509 break; 1510 } 1511 if( nn ) { 1512 _worklist.push(n); 1513 // Put users of 'n' onto worklist for second igvn transform 1514 add_users_to_worklist(n); 1515 return nn; 1516 } 1517 1518 return n; 1519 } 1520 1521 //---------------------------------saturate------------------------------------ 1522 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type, 1523 const Type* limit_type) const { 1524 const Type* wide_type = new_type->widen(old_type, limit_type); 1525 if (wide_type != new_type) { // did we widen? 1526 // If so, we may have widened beyond the limit type. Clip it back down. 1527 new_type = wide_type->filter(limit_type); 1528 } 1529 return new_type; 1530 } 1531 1532 //------------------------------print_statistics------------------------------- 1533 #ifndef PRODUCT 1534 void PhaseCCP::print_statistics() { 1535 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants); 1536 } 1537 #endif 1538 1539 1540 //============================================================================= 1541 #ifndef PRODUCT 1542 uint PhasePeephole::_total_peepholes = 0; 1543 #endif 1544 //------------------------------PhasePeephole---------------------------------- 1545 // Conditional Constant Propagation, ala Wegman & Zadeck 1546 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ) 1547 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) { 1548 NOT_PRODUCT( clear_peepholes(); ) 1549 } 1550 1551 #ifndef PRODUCT 1552 //------------------------------~PhasePeephole--------------------------------- 1553 PhasePeephole::~PhasePeephole() { 1554 _total_peepholes += count_peepholes(); 1555 } 1556 #endif 1557 1558 //------------------------------transform-------------------------------------- 1559 Node *PhasePeephole::transform( Node *n ) { 1560 ShouldNotCallThis(); 1561 return NULL; 1562 } 1563 1564 //------------------------------do_transform----------------------------------- 1565 void PhasePeephole::do_transform() { 1566 bool method_name_not_printed = true; 1567 1568 // Examine each basic block 1569 for( uint block_number = 1; block_number < _cfg._num_blocks; ++block_number ) { 1570 Block *block = _cfg._blocks[block_number]; 1571 bool block_not_printed = true; 1572 1573 // and each instruction within a block 1574 uint end_index = block->_nodes.size(); 1575 // block->end_idx() not valid after PhaseRegAlloc 1576 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) { 1577 Node *n = block->_nodes.at(instruction_index); 1578 if( n->is_Mach() ) { 1579 MachNode *m = n->as_Mach(); 1580 int deleted_count = 0; 1581 // check for peephole opportunities 1582 MachNode *m2 = m->peephole( block, instruction_index, _regalloc, deleted_count, C ); 1583 if( m2 != NULL ) { 1584 #ifndef PRODUCT 1585 if( PrintOptoPeephole ) { 1586 // Print method, first time only 1587 if( C->method() && method_name_not_printed ) { 1588 C->method()->print_short_name(); tty->cr(); 1589 method_name_not_printed = false; 1590 } 1591 // Print this block 1592 if( Verbose && block_not_printed) { 1593 tty->print_cr("in block"); 1594 block->dump(); 1595 block_not_printed = false; 1596 } 1597 // Print instructions being deleted 1598 for( int i = (deleted_count - 1); i >= 0; --i ) { 1599 block->_nodes.at(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr(); 1600 } 1601 tty->print_cr("replaced with"); 1602 // Print new instruction 1603 m2->format(_regalloc); 1604 tty->print("\n\n"); 1605 } 1606 #endif 1607 // Remove old nodes from basic block and update instruction_index 1608 // (old nodes still exist and may have edges pointing to them 1609 // as register allocation info is stored in the allocator using 1610 // the node index to live range mappings.) 1611 uint safe_instruction_index = (instruction_index - deleted_count); 1612 for( ; (instruction_index > safe_instruction_index); --instruction_index ) { 1613 block->_nodes.remove( instruction_index ); 1614 } 1615 // install new node after safe_instruction_index 1616 block->_nodes.insert( safe_instruction_index + 1, m2 ); 1617 end_index = block->_nodes.size() - 1; // Recompute new block size 1618 NOT_PRODUCT( inc_peepholes(); ) 1619 } 1620 } 1621 } 1622 } 1623 } 1624 1625 //------------------------------print_statistics------------------------------- 1626 #ifndef PRODUCT 1627 void PhasePeephole::print_statistics() { 1628 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes); 1629 } 1630 #endif 1631 1632 1633 //============================================================================= 1634 //------------------------------set_req_X-------------------------------------- 1635 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) { 1636 assert( is_not_dead(n), "can not use dead node"); 1637 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" ); 1638 Node *old = in(i); 1639 set_req(i, n); 1640 1641 // old goes dead? 1642 if( old ) { 1643 switch (old->outcnt()) { 1644 case 0: 1645 // Put into the worklist to kill later. We do not kill it now because the 1646 // recursive kill will delete the current node (this) if dead-loop exists 1647 if (!old->is_top()) 1648 igvn->_worklist.push( old ); 1649 break; 1650 case 1: 1651 if( old->is_Store() || old->has_special_unique_user() ) 1652 igvn->add_users_to_worklist( old ); 1653 break; 1654 case 2: 1655 if( old->is_Store() ) 1656 igvn->add_users_to_worklist( old ); 1657 if( old->Opcode() == Op_Region ) 1658 igvn->_worklist.push(old); 1659 break; 1660 case 3: 1661 if( old->Opcode() == Op_Region ) { 1662 igvn->_worklist.push(old); 1663 igvn->add_users_to_worklist( old ); 1664 } 1665 break; 1666 default: 1667 break; 1668 } 1669 } 1670 1671 } 1672 1673 //-------------------------------replace_by----------------------------------- 1674 // Using def-use info, replace one node for another. Follow the def-use info 1675 // to all users of the OLD node. Then make all uses point to the NEW node. 1676 void Node::replace_by(Node *new_node) { 1677 assert(!is_top(), "top node has no DU info"); 1678 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) { 1679 Node* use = last_out(i); 1680 uint uses_found = 0; 1681 for (uint j = 0; j < use->len(); j++) { 1682 if (use->in(j) == this) { 1683 if (j < use->req()) 1684 use->set_req(j, new_node); 1685 else use->set_prec(j, new_node); 1686 uses_found++; 1687 } 1688 } 1689 i -= uses_found; // we deleted 1 or more copies of this edge 1690 } 1691 } 1692 1693 //============================================================================= 1694 //----------------------------------------------------------------------------- 1695 void Type_Array::grow( uint i ) { 1696 if( !_max ) { 1697 _max = 1; 1698 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) ); 1699 _types[0] = NULL; 1700 } 1701 uint old = _max; 1702 while( i >= _max ) _max <<= 1; // Double to fit 1703 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*)); 1704 memset( &_types[old], 0, (_max-old)*sizeof(Type*) ); 1705 } 1706 1707 //------------------------------dump------------------------------------------- 1708 #ifndef PRODUCT 1709 void Type_Array::dump() const { 1710 uint max = Size(); 1711 for( uint i = 0; i < max; i++ ) { 1712 if( _types[i] != NULL ) { 1713 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr(); 1714 } 1715 } 1716 } 1717 #endif