1 /* 2 * Copyright (c) 1997, 2023, 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 #ifndef SHARE_OPTO_PHASEX_HPP 26 #define SHARE_OPTO_PHASEX_HPP 27 28 #include "libadt/dict.hpp" 29 #include "libadt/vectset.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "opto/memnode.hpp" 32 #include "opto/node.hpp" 33 #include "opto/phase.hpp" 34 #include "opto/type.hpp" 35 #include "utilities/globalDefinitions.hpp" 36 37 class BarrierSetC2; 38 class Compile; 39 class ConINode; 40 class ConLNode; 41 class Node; 42 class Type; 43 class PhaseTransform; 44 class PhaseGVN; 45 class PhaseIterGVN; 46 class PhaseCCP; 47 class PhasePeephole; 48 class PhaseRegAlloc; 49 50 51 //----------------------------------------------------------------------------- 52 // Expandable closed hash-table of nodes, initialized to null. 53 // Note that the constructor just zeros things 54 // Storage is reclaimed when the Arena's lifetime is over. 55 class NodeHash : public AnyObj { 56 protected: 57 Arena *_a; // Arena to allocate in 58 uint _max; // Size of table (power of 2) 59 uint _inserts; // For grow and debug, count of hash_inserts 60 uint _insert_limit; // 'grow' when _inserts reaches _insert_limit 61 Node **_table; // Hash table of Node pointers 62 Node *_sentinel; // Replaces deleted entries in hash table 63 64 public: 65 NodeHash(Arena *arena, uint est_max_size); 66 #ifdef ASSERT 67 ~NodeHash(); // Unlock all nodes upon destruction of table. 68 #endif 69 Node *hash_find(const Node*);// Find an equivalent version in hash table 70 Node *hash_find_insert(Node*);// If not in table insert else return found node 71 void hash_insert(Node*); // Insert into hash table 72 bool hash_delete(const Node*);// Replace with _sentinel in hash table 73 void check_grow() { 74 _inserts++; 75 if( _inserts == _insert_limit ) { grow(); } 76 assert( _inserts <= _insert_limit, "hash table overflow"); 77 assert( _inserts < _max, "hash table overflow" ); 78 } 79 static uint round_up(uint); // Round up to nearest power of 2 80 void grow(); // Grow _table to next power of 2 and rehash 81 // Return 75% of _max, rounded up. 82 uint insert_limit() const { return _max - (_max>>2); } 83 84 void clear(); // Set all entries to null, keep storage. 85 // Size of hash table 86 uint size() const { return _max; } 87 // Return Node* at index in table 88 Node *at(uint table_index) { 89 assert(table_index < _max, "Must be within table"); 90 return _table[table_index]; 91 } 92 93 void remove_useless_nodes(VectorSet& useful); // replace with sentinel 94 void check_no_speculative_types(); // Check no speculative part for type nodes in table 95 96 Node *sentinel() { return _sentinel; } 97 98 #ifndef PRODUCT 99 Node *find_index(uint idx); // For debugging 100 void dump(); // For debugging, dump statistics 101 uint _grows; // For debugging, count of table grow()s 102 uint _look_probes; // For debugging, count of hash probes 103 uint _lookup_hits; // For debugging, count of hash_finds 104 uint _lookup_misses; // For debugging, count of hash_finds 105 uint _insert_probes; // For debugging, count of hash probes 106 uint _delete_probes; // For debugging, count of hash probes for deletes 107 uint _delete_hits; // For debugging, count of hash probes for deletes 108 uint _delete_misses; // For debugging, count of hash probes for deletes 109 uint _total_inserts; // For debugging, total inserts into hash table 110 uint _total_insert_probes; // For debugging, total probes while inserting 111 #endif 112 NONCOPYABLE(NodeHash); 113 }; 114 115 116 //----------------------------------------------------------------------------- 117 // Map dense integer indices to Types. Uses classic doubling-array trick. 118 // Abstractly provides an infinite array of Type*'s, initialized to null. 119 // Note that the constructor just zeros things, and since I use Arena 120 // allocation I do not need a destructor to reclaim storage. 121 // Despite the general name, this class is customized for use by PhaseValues. 122 class Type_Array : public AnyObj { 123 Arena *_a; // Arena to allocate in 124 uint _max; 125 const Type **_types; 126 void grow( uint i ); // Grow array node to fit 127 const Type *operator[] ( uint i ) const // Lookup, or null for not mapped 128 { return (i<_max) ? _types[i] : (Type*)nullptr; } 129 friend class PhaseValues; 130 public: 131 Type_Array(Arena *a) : _a(a), _max(0), _types(0) {} 132 const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];} 133 // Extend the mapping: index i maps to Type *n. 134 void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; } 135 uint Size() const { return _max; } 136 #ifndef PRODUCT 137 void dump() const; 138 #endif 139 void swap(Type_Array &other) { 140 if (this != &other) { 141 assert(_a == other._a, "swapping for differing arenas is probably a bad idea"); 142 ::swap(_max, other._max); 143 ::swap(_types, other._types); 144 } 145 } 146 NONCOPYABLE(Type_Array); 147 }; 148 149 150 //------------------------------PhaseRemoveUseless----------------------------- 151 // Remove useless nodes from GVN hash-table, worklist, and graph 152 class PhaseRemoveUseless : public Phase { 153 protected: 154 Unique_Node_List _useful; // Nodes reachable from root 155 // list is allocated from current resource area 156 public: 157 PhaseRemoveUseless(PhaseGVN* gvn, Unique_Node_List& worklist, PhaseNumber phase_num = Remove_Useless); 158 159 Unique_Node_List *get_useful() { return &_useful; } 160 }; 161 162 //------------------------------PhaseRenumber---------------------------------- 163 // Phase that first performs a PhaseRemoveUseless, then it renumbers compiler 164 // structures accordingly. 165 class PhaseRenumberLive : public PhaseRemoveUseless { 166 protected: 167 Type_Array _new_type_array; // Storage for the updated type information. 168 GrowableArray<int> _old2new_map; 169 Node_List _delayed; 170 bool _is_pass_finished; 171 uint _live_node_count; 172 173 int update_embedded_ids(Node* n); 174 int new_index(int old_idx); 175 176 public: 177 PhaseRenumberLive(PhaseGVN* gvn, 178 Unique_Node_List& worklist, 179 PhaseNumber phase_num = Remove_Useless_And_Renumber_Live); 180 }; 181 182 183 //------------------------------PhaseTransform--------------------------------- 184 // Phases that analyze, then transform. Constructing the Phase object does any 185 // global or slow analysis. The results are cached later for a fast 186 // transformation pass. When the Phase object is deleted the cached analysis 187 // results are deleted. 188 class PhaseTransform : public Phase { 189 public: 190 PhaseTransform(PhaseNumber pnum) : Phase(pnum) { 191 #ifndef PRODUCT 192 clear_progress(); 193 clear_transforms(); 194 set_allow_progress(true); 195 #endif 196 } 197 198 // Return a node which computes the same function as this node, but 199 // in a faster or cheaper fashion. 200 virtual Node *transform( Node *n ) = 0; 201 202 // true if CFG node d dominates CFG node n 203 virtual bool is_dominator(Node *d, Node *n) { fatal("unimplemented for this pass"); return false; }; 204 205 #ifndef PRODUCT 206 uint _count_progress; // For profiling, count transforms that make progress 207 void set_progress() { ++_count_progress; assert( allow_progress(),"No progress allowed during verification"); } 208 void clear_progress() { _count_progress = 0; } 209 uint made_progress() const { return _count_progress; } 210 211 uint _count_transforms; // For profiling, count transforms performed 212 void set_transforms() { ++_count_transforms; } 213 void clear_transforms() { _count_transforms = 0; } 214 uint made_transforms() const{ return _count_transforms; } 215 216 bool _allow_progress; // progress not allowed during verification pass 217 void set_allow_progress(bool allow) { _allow_progress = allow; } 218 bool allow_progress() { return _allow_progress; } 219 #endif 220 }; 221 222 // Phase infrastructure required for Node::Value computations. 223 // 1) Type array, and accessor methods. 224 // 2) Constants cache, which requires access to the types. 225 // 3) NodeHash table, to find identical nodes (and remove/update the hash of a node on modification). 226 class PhaseValues : public PhaseTransform { 227 protected: 228 bool _iterGVN; 229 230 // Hash table for value-numbering. Reference to "C->node_hash()", 231 NodeHash &_table; 232 233 // Type array mapping node idx to Type*. Reference to "C->types()". 234 Type_Array &_types; 235 236 // ConNode caches: 237 // Support both int and long caches because either might be an intptr_t, 238 // so they show up frequently in address computations. 239 enum { _icon_min = -1 * HeapWordSize, 240 _icon_max = 16 * HeapWordSize, 241 _lcon_min = _icon_min, 242 _lcon_max = _icon_max, 243 _zcon_max = (uint)T_CONFLICT 244 }; 245 ConINode* _icons[_icon_max - _icon_min + 1]; // cached jint constant nodes 246 ConLNode* _lcons[_lcon_max - _lcon_min + 1]; // cached jlong constant nodes 247 ConNode* _zcons[_zcon_max + 1]; // cached is_zero_type nodes 248 void init_con_caches(); 249 250 public: 251 PhaseValues() : PhaseTransform(GVN), _iterGVN(false), 252 _table(*C->node_hash()), _types(*C->types()) 253 { 254 NOT_PRODUCT( clear_new_values(); ) 255 // Force allocation for currently existing nodes 256 _types.map(C->unique(), nullptr); 257 init_con_caches(); 258 } 259 NOT_PRODUCT(~PhaseValues();) 260 PhaseIterGVN* is_IterGVN() { return (_iterGVN) ? (PhaseIterGVN*)this : nullptr; } 261 262 // Some Ideal and other transforms delete --> modify --> insert values 263 bool hash_delete(Node* n) { return _table.hash_delete(n); } 264 void hash_insert(Node* n) { _table.hash_insert(n); } 265 Node* hash_find_insert(Node* n){ return _table.hash_find_insert(n); } 266 Node* hash_find(const Node* n) { return _table.hash_find(n); } 267 268 // Used after parsing to eliminate values that are no longer in program 269 void remove_useless_nodes(VectorSet &useful) { 270 _table.remove_useless_nodes(useful); 271 // this may invalidate cached cons so reset the cache 272 init_con_caches(); 273 } 274 275 Type_Array& types() { 276 return _types; 277 } 278 279 // Get a previously recorded type for the node n. 280 // This type must already have been recorded. 281 // If you want the type of a very new (untransformed) node, 282 // you must use type_or_null, and test the result for null. 283 const Type* type(const Node* n) const { 284 assert(n != nullptr, "must not be null"); 285 const Type* t = _types.fast_lookup(n->_idx); 286 assert(t != nullptr, "must set before get"); 287 return t; 288 } 289 // Get a previously recorded type for the node n, 290 // or else return null if there is none. 291 const Type* type_or_null(const Node* n) const { 292 return _types.fast_lookup(n->_idx); 293 } 294 // Record a type for a node. 295 void set_type(const Node* n, const Type *t) { 296 assert(t != nullptr, "type must not be null"); 297 _types.map(n->_idx, t); 298 } 299 void clear_type(const Node* n) { 300 if (n->_idx < _types.Size()) { 301 _types.map(n->_idx, nullptr); 302 } 303 } 304 // Record an initial type for a node, the node's bottom type. 305 void set_type_bottom(const Node* n) { 306 // Use this for initialization when bottom_type() (or better) is not handy. 307 // Usually the initialization should be to n->Value(this) instead, 308 // or a hand-optimized value like Type::MEMORY or Type::CONTROL. 309 assert(_types[n->_idx] == nullptr, "must set the initial type just once"); 310 _types.map(n->_idx, n->bottom_type()); 311 } 312 // Make sure the types array is big enough to record a size for the node n. 313 // (In product builds, we never want to do range checks on the types array!) 314 void ensure_type_or_null(const Node* n) { 315 if (n->_idx >= _types.Size()) 316 _types.map(n->_idx, nullptr); // Grow the types array as needed. 317 } 318 319 // Utility functions: 320 const TypeInt* find_int_type( Node* n); 321 const TypeLong* find_long_type(Node* n); 322 jint find_int_con( Node* n, jint value_if_unknown) { 323 const TypeInt* t = find_int_type(n); 324 return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown; 325 } 326 jlong find_long_con(Node* n, jlong value_if_unknown) { 327 const TypeLong* t = find_long_type(n); 328 return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown; 329 } 330 331 // Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc. 332 // Same as transform(ConNode::make(t)). 333 ConNode* makecon(const Type* t); 334 ConNode* uncached_makecon(const Type* t); 335 336 // Fast int or long constant. Same as TypeInt::make(i) or TypeLong::make(l). 337 ConINode* intcon(jint i); 338 ConLNode* longcon(jlong l); 339 ConNode* integercon(jlong l, BasicType bt); 340 341 // Fast zero or null constant. Same as makecon(Type::get_zero_type(bt)). 342 ConNode* zerocon(BasicType bt); 343 344 // For pessimistic passes, the return type must monotonically narrow. 345 // For optimistic passes, the return type must monotonically widen. 346 // It is possible to get into a "death march" in either type of pass, 347 // where the types are continually moving but it will take 2**31 or 348 // more steps to converge. This doesn't happen on most normal loops. 349 // 350 // Here is an example of a deadly loop for an optimistic pass, along 351 // with a partial trace of inferred types: 352 // x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L; 353 // 0 1 join([0..max], 1) 354 // [0..1] [1..2] join([0..max], [1..2]) 355 // [0..2] [1..3] join([0..max], [1..3]) 356 // ... ... ... 357 // [0..max] [min]u[1..max] join([0..max], [min..max]) 358 // [0..max] ==> fixpoint 359 // We would have proven, the hard way, that the iteration space is all 360 // non-negative ints, with the loop terminating due to 32-bit overflow. 361 // 362 // Here is the corresponding example for a pessimistic pass: 363 // x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L; 364 // int int join([0..max], int) 365 // [0..max] [-1..max-1] join([0..max], [-1..max-1]) 366 // [0..max-1] [-1..max-2] join([0..max], [-1..max-2]) 367 // ... ... ... 368 // [0..1] [-1..0] join([0..max], [-1..0]) 369 // 0 -1 join([0..max], -1) 370 // 0 == fixpoint 371 // We would have proven, the hard way, that the iteration space is {0}. 372 // (Usually, other optimizations will make the "if (x >= 0)" fold up 373 // before we get into trouble. But not always.) 374 // 375 // It's a pleasant thing to observe that the pessimistic pass 376 // will make short work of the optimistic pass's deadly loop, 377 // and vice versa. That is a good example of the complementary 378 // purposes of the CCP (optimistic) vs. GVN (pessimistic) phases. 379 // 380 // In any case, only widen or narrow a few times before going to the 381 // correct flavor of top or bottom. 382 // 383 // This call only needs to be made once as the data flows around any 384 // given cycle. We do it at Phis, and nowhere else. 385 // The types presented are the new type of a phi (computed by PhiNode::Value) 386 // and the previously computed type, last time the phi was visited. 387 // 388 // The third argument is upper limit for the saturated value, 389 // if the phase wishes to widen the new_type. 390 // If the phase is narrowing, the old type provides a lower limit. 391 // Caller guarantees that old_type and new_type are no higher than limit_type. 392 virtual const Type* saturate(const Type* new_type, 393 const Type* old_type, 394 const Type* limit_type) const { 395 return new_type; 396 } 397 virtual const Type* saturate_and_maybe_push_to_igvn_worklist(const TypeNode* n, const Type* new_type) { 398 return saturate(new_type, type_or_null(n), n->type()); 399 } 400 401 #ifndef PRODUCT 402 uint _count_new_values; // For profiling, count new values produced 403 void inc_new_values() { ++_count_new_values; } 404 void clear_new_values() { _count_new_values = 0; } 405 uint made_new_values() const { return _count_new_values; } 406 #endif 407 }; 408 409 410 //------------------------------PhaseGVN--------------------------------------- 411 // Phase for performing local, pessimistic GVN-style optimizations. 412 class PhaseGVN : public PhaseValues { 413 protected: 414 bool is_dominator_helper(Node *d, Node *n, bool linear_only); 415 416 public: 417 // Return a node which computes the same function as this node, but 418 // in a faster or cheaper fashion. 419 Node *transform( Node *n ); 420 Node *transform_no_reclaim( Node *n ); 421 virtual void record_for_igvn(Node *n) { 422 C->record_for_igvn(n); 423 } 424 425 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, true); } 426 427 // Helper to call Node::Ideal() and BarrierSetC2::ideal_node(). 428 Node* apply_ideal(Node* i, bool can_reshape); 429 430 #ifdef ASSERT 431 void dump_infinite_loop_info(Node* n, const char* where); 432 // Check for a simple dead loop when a data node references itself. 433 void dead_loop_check(Node *n); 434 #endif 435 }; 436 437 //------------------------------PhaseIterGVN----------------------------------- 438 // Phase for iteratively performing local, pessimistic GVN-style optimizations. 439 // and ideal transformations on the graph. 440 class PhaseIterGVN : public PhaseGVN { 441 private: 442 bool _delay_transform; // When true simply register the node when calling transform 443 // instead of actually optimizing it 444 445 // Idealize old Node 'n' with respect to its inputs and its value 446 virtual Node *transform_old( Node *a_node ); 447 448 // Subsume users of node 'old' into node 'nn' 449 void subsume_node( Node *old, Node *nn ); 450 451 protected: 452 // Shuffle worklist, for stress testing 453 void shuffle_worklist(); 454 455 virtual const Type* saturate(const Type* new_type, const Type* old_type, 456 const Type* limit_type) const; 457 // Usually returns new_type. Returns old_type if new_type is only a slight 458 // improvement, such that it would take many (>>10) steps to reach 2**32. 459 460 public: 461 462 PhaseIterGVN(PhaseIterGVN* igvn); // Used by CCP constructor 463 PhaseIterGVN(PhaseGVN* gvn); // Used after Parser 464 465 // Reset IGVN from GVN: call deconstructor, and placement new. 466 // Achieves the same as the following (but without move constructors): 467 // igvn = PhaseIterGVN(gvn); 468 void reset_from_gvn(PhaseGVN* gvn) { 469 if (this != gvn) { 470 this->~PhaseIterGVN(); 471 ::new (static_cast<void*>(this)) PhaseIterGVN(gvn); 472 } 473 } 474 475 // Reset IGVN with another: call deconstructor, and placement new. 476 // Achieves the same as the following (but without move constructors): 477 // igvn = PhaseIterGVN(other); 478 void reset_from_igvn(PhaseIterGVN* other) { 479 if (this != other) { 480 this->~PhaseIterGVN(); 481 ::new (static_cast<void*>(this)) PhaseIterGVN(other); 482 } 483 } 484 485 // Idealize new Node 'n' with respect to its inputs and its value 486 virtual Node *transform( Node *a_node ); 487 virtual void record_for_igvn(Node *n) { } 488 489 // Iterative worklist. Reference to "C->igvn_worklist()". 490 Unique_Node_List &_worklist; 491 492 // Given def-use info and an initial worklist, apply Node::Ideal, 493 // Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU 494 // and dominator info to a fixed point. 495 void optimize(); 496 #ifdef ASSERT 497 void verify_optimize(); 498 bool verify_node_value(Node* n); 499 #endif 500 501 #ifndef PRODUCT 502 void trace_PhaseIterGVN(Node* n, Node* nn, const Type* old_type); 503 void init_verifyPhaseIterGVN(); 504 void verify_PhaseIterGVN(); 505 #endif 506 507 #ifdef ASSERT 508 void dump_infinite_loop_info(Node* n, const char* where); 509 void trace_PhaseIterGVN_verbose(Node* n, int num_processed); 510 #endif 511 512 // Register a new node with the iter GVN pass without transforming it. 513 // Used when we need to restructure a Region/Phi area and all the Regions 514 // and Phis need to complete this one big transform before any other 515 // transforms can be triggered on the region. 516 // Optional 'orig' is an earlier version of this node. 517 // It is significant only for debugging and profiling. 518 Node* register_new_node_with_optimizer(Node* n, Node* orig = nullptr); 519 520 // Kill a globally dead Node. All uses are also globally dead and are 521 // aggressively trimmed. 522 void remove_globally_dead_node( Node *dead ); 523 524 // Kill all inputs to a dead node, recursively making more dead nodes. 525 // The Node must be dead locally, i.e., have no uses. 526 void remove_dead_node( Node *dead ) { 527 assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead"); 528 remove_globally_dead_node(dead); 529 } 530 531 // Add users of 'n' to worklist 532 void add_users_to_worklist0( Node *n ); 533 void add_users_to_worklist ( Node *n ); 534 535 // Replace old node with new one. 536 void replace_node( Node *old, Node *nn ) { 537 add_users_to_worklist(old); 538 hash_delete(old); // Yank from hash before hacking edges 539 subsume_node(old, nn); 540 } 541 542 // Delayed node rehash: remove a node from the hash table and rehash it during 543 // next optimizing pass 544 void rehash_node_delayed(Node* n) { 545 hash_delete(n); 546 _worklist.push(n); 547 } 548 549 // Replace ith edge of "n" with "in" 550 void replace_input_of(Node* n, int i, Node* in) { 551 rehash_node_delayed(n); 552 n->set_req_X(i, in, this); 553 } 554 555 // Add "in" as input (req) of "n" 556 void add_input_to(Node* n, Node* in) { 557 rehash_node_delayed(n); 558 n->add_req(in); 559 } 560 561 // Delete ith edge of "n" 562 void delete_input_of(Node* n, int i) { 563 rehash_node_delayed(n); 564 n->del_req(i); 565 } 566 567 // Delete precedence edge i of "n" 568 void delete_precedence_of(Node* n, int i) { 569 rehash_node_delayed(n); 570 n->rm_prec(i); 571 } 572 573 bool delay_transform() const { return _delay_transform; } 574 575 void set_delay_transform(bool delay) { 576 _delay_transform = delay; 577 } 578 579 void remove_speculative_types(); 580 void check_no_speculative_types() { 581 _table.check_no_speculative_types(); 582 } 583 584 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, false); } 585 bool no_dependent_zero_check(Node* n) const; 586 587 #ifndef PRODUCT 588 static bool is_verify_def_use() { 589 // '-XX:VerifyIterativeGVN=1' 590 return (VerifyIterativeGVN % 10) == 1; 591 } 592 static bool is_verify_Value() { 593 // '-XX:VerifyIterativeGVN=10' 594 return ((VerifyIterativeGVN % 100) / 10) == 1; 595 } 596 protected: 597 // Sub-quadratic implementation of '-XX:VerifyIterativeGVN=1' (Use-Def verification). 598 julong _verify_counter; 599 julong _verify_full_passes; 600 enum { _verify_window_size = 30 }; 601 Node* _verify_window[_verify_window_size]; 602 void verify_step(Node* n); 603 #endif 604 }; 605 606 //------------------------------PhaseCCP--------------------------------------- 607 // Phase for performing global Conditional Constant Propagation. 608 // Should be replaced with combined CCP & GVN someday. 609 class PhaseCCP : public PhaseIterGVN { 610 Unique_Node_List _root_and_safepoints; 611 // Non-recursive. Use analysis to transform single Node. 612 virtual Node* transform_once(Node* n); 613 614 Node* fetch_next_node(Unique_Node_List& worklist); 615 static void dump_type_and_node(const Node* n, const Type* t) PRODUCT_RETURN; 616 617 void push_child_nodes_to_worklist(Unique_Node_List& worklist, Node* n) const; 618 void push_if_not_bottom_type(Unique_Node_List& worklist, Node* n) const; 619 void push_more_uses(Unique_Node_List& worklist, Node* parent, const Node* use) const; 620 void push_phis(Unique_Node_List& worklist, const Node* use) const; 621 static void push_catch(Unique_Node_List& worklist, const Node* use); 622 void push_cmpu(Unique_Node_List& worklist, const Node* use) const; 623 static void push_counted_loop_phi(Unique_Node_List& worklist, Node* parent, const Node* use); 624 void push_loadp(Unique_Node_List& worklist, const Node* use) const; 625 static void push_load_barrier(Unique_Node_List& worklist, const BarrierSetC2* barrier_set, const Node* use); 626 void push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const; 627 void push_cast_ii(Unique_Node_List& worklist, const Node* parent, const Node* use) const; 628 void push_opaque_zero_trip_guard(Unique_Node_List& worklist, const Node* use) const; 629 630 public: 631 PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants 632 NOT_PRODUCT( ~PhaseCCP(); ) 633 634 // Worklist algorithm identifies constants 635 void analyze(); 636 #ifdef ASSERT 637 void verify_type(Node* n, const Type* tnew, const Type* told); 638 // For every node n on verify list, check if type(n) == n->Value() 639 void verify_analyze(Unique_Node_List& worklist_verify); 640 #endif 641 // Recursive traversal of program. Used analysis to modify program. 642 virtual Node *transform( Node *n ); 643 // Do any transformation after analysis 644 void do_transform(); 645 646 virtual const Type* saturate(const Type* new_type, const Type* old_type, 647 const Type* limit_type) const; 648 // Returns new_type->widen(old_type), which increments the widen bits until 649 // giving up with TypeInt::INT or TypeLong::LONG. 650 // Result is clipped to limit_type if necessary. 651 virtual const Type* saturate_and_maybe_push_to_igvn_worklist(const TypeNode* n, const Type* new_type) { 652 const Type* t = saturate(new_type, type_or_null(n), n->type()); 653 if (t != new_type) { 654 // Type was widened in CCP, but IGVN may be able to make it narrower. 655 _worklist.push((Node*)n); 656 } 657 return t; 658 } 659 660 #ifndef PRODUCT 661 static uint _total_invokes; // For profiling, count invocations 662 void inc_invokes() { ++PhaseCCP::_total_invokes; } 663 664 static uint _total_constants; // For profiling, count constants found 665 uint _count_constants; 666 void clear_constants() { _count_constants = 0; } 667 void inc_constants() { ++_count_constants; } 668 uint count_constants() const { return _count_constants; } 669 670 static void print_statistics(); 671 #endif 672 }; 673 674 675 //------------------------------PhasePeephole---------------------------------- 676 // Phase for performing peephole optimizations on register allocated basic blocks. 677 class PhasePeephole : public PhaseTransform { 678 PhaseRegAlloc *_regalloc; 679 PhaseCFG &_cfg; 680 // Recursive traversal of program. Pure function is unused in this phase 681 virtual Node *transform( Node *n ); 682 683 public: 684 PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ); 685 NOT_PRODUCT( ~PhasePeephole(); ) 686 687 // Do any transformation after analysis 688 void do_transform(); 689 690 #ifndef PRODUCT 691 static uint _total_peepholes; // For profiling, count peephole rules applied 692 uint _count_peepholes; 693 void clear_peepholes() { _count_peepholes = 0; } 694 void inc_peepholes() { ++_count_peepholes; } 695 uint count_peepholes() const { return _count_peepholes; } 696 697 static void print_statistics(); 698 #endif 699 }; 700 701 #endif // SHARE_OPTO_PHASEX_HPP