1 /* 2 * Copyright (c) 1997, 2013, 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_VM_OPTO_PHASEX_HPP 26 #define SHARE_VM_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 36 class Compile; 37 class ConINode; 38 class ConLNode; 39 class Node; 40 class Type; 41 class PhaseTransform; 42 class PhaseGVN; 43 class PhaseIterGVN; 44 class PhaseCCP; 45 class PhasePeephole; 46 class PhaseRegAlloc; 47 48 49 //----------------------------------------------------------------------------- 50 // Expandable closed hash-table of nodes, initialized to NULL. 51 // Note that the constructor just zeros things 52 // Storage is reclaimed when the Arena's lifetime is over. 53 class NodeHash : public StackObj { 54 protected: 55 Arena *_a; // Arena to allocate in 56 uint _max; // Size of table (power of 2) 57 uint _inserts; // For grow and debug, count of hash_inserts 58 uint _insert_limit; // 'grow' when _inserts reaches _insert_limit 59 Node **_table; // Hash table of Node pointers 60 Node *_sentinel; // Replaces deleted entries in hash table 61 62 public: 63 NodeHash(uint est_max_size); 64 NodeHash(Arena *arena, uint est_max_size); 65 NodeHash(NodeHash *use_this_state); 66 #ifdef ASSERT 67 ~NodeHash(); // Unlock all nodes upon destruction of table. 68 void operator=(const NodeHash&); // Unlock all nodes upon replacement of table. 69 #endif 70 Node *hash_find(const Node*);// Find an equivalent version in hash table 71 Node *hash_find_insert(Node*);// If not in table insert else return found node 72 void hash_insert(Node*); // Insert into hash table 73 bool hash_delete(const Node*);// Replace with _sentinel in hash table 74 void check_grow() { 75 _inserts++; 76 if( _inserts == _insert_limit ) { grow(); } 77 assert( _inserts <= _insert_limit, "hash table overflow"); 78 assert( _inserts < _max, "hash table overflow" ); 79 } 80 static uint round_up(uint); // Round up to nearest power of 2 81 void grow(); // Grow _table to next power of 2 and rehash 82 // Return 75% of _max, rounded up. 83 uint insert_limit() const { return _max - (_max>>2); } 84 85 void clear(); // Set all entries to NULL, keep storage. 86 // Size of hash table 87 uint size() const { return _max; } 88 // Return Node* at index in table 89 Node *at(uint table_index) { 90 assert(table_index < _max, "Must be within table"); 91 return _table[table_index]; 92 } 93 94 void remove_useless_nodes(VectorSet &useful); // replace with sentinel 95 void replace_with(NodeHash* nh); 96 void check_no_speculative_types(); // Check no speculative part for type nodes in table 97 98 Node *sentinel() { return _sentinel; } 99 100 #ifndef PRODUCT 101 Node *find_index(uint idx); // For debugging 102 void dump(); // For debugging, dump statistics 103 uint _grows; // For debugging, count of table grow()s 104 uint _look_probes; // For debugging, count of hash probes 105 uint _lookup_hits; // For debugging, count of hash_finds 106 uint _lookup_misses; // For debugging, count of hash_finds 107 uint _insert_probes; // For debugging, count of hash probes 108 uint _delete_probes; // For debugging, count of hash probes for deletes 109 uint _delete_hits; // For debugging, count of hash probes for deletes 110 uint _delete_misses; // For debugging, count of hash probes for deletes 111 uint _total_inserts; // For debugging, total inserts into hash table 112 uint _total_insert_probes; // For debugging, total probes while inserting 113 #endif 114 }; 115 116 117 //----------------------------------------------------------------------------- 118 // Map dense integer indices to Types. Uses classic doubling-array trick. 119 // Abstractly provides an infinite array of Type*'s, initialized to NULL. 120 // Note that the constructor just zeros things, and since I use Arena 121 // allocation I do not need a destructor to reclaim storage. 122 // Despite the general name, this class is customized for use by PhaseTransform. 123 class Type_Array : public StackObj { 124 Arena *_a; // Arena to allocate in 125 uint _max; 126 const Type **_types; 127 void grow( uint i ); // Grow array node to fit 128 const Type *operator[] ( uint i ) const // Lookup, or NULL for not mapped 129 { return (i<_max) ? _types[i] : (Type*)NULL; } 130 friend class PhaseTransform; 131 public: 132 Type_Array(Arena *a) : _a(a), _max(0), _types(0) {} 133 Type_Array(Type_Array *ta) : _a(ta->_a), _max(ta->_max), _types(ta->_types) { } 134 const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];} 135 // Extend the mapping: index i maps to Type *n. 136 void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; } 137 uint Size() const { return _max; } 138 #ifndef PRODUCT 139 void dump() const; 140 #endif 141 }; 142 143 144 //------------------------------PhaseRemoveUseless----------------------------- 145 // Remove useless nodes from GVN hash-table, worklist, and graph 146 class PhaseRemoveUseless : public Phase { 147 protected: 148 Unique_Node_List _useful; // Nodes reachable from root 149 // list is allocated from current resource area 150 public: 151 PhaseRemoveUseless(PhaseGVN *gvn, Unique_Node_List *worklist, PhaseNumber phase_num = Remove_Useless); 152 153 Unique_Node_List *get_useful() { return &_useful; } 154 }; 155 156 //------------------------------PhaseRenumber---------------------------------- 157 // Phase that first performs a PhaseRemoveUseless, then it renumbers compiler 158 // structures accordingly. 159 class PhaseRenumberLive : public PhaseRemoveUseless { 160 public: 161 PhaseRenumberLive(PhaseGVN* gvn, 162 Unique_Node_List* worklist, Unique_Node_List* new_worklist, 163 PhaseNumber phase_num = Remove_Useless_And_Renumber_Live); 164 }; 165 166 167 //------------------------------PhaseTransform--------------------------------- 168 // Phases that analyze, then transform. Constructing the Phase object does any 169 // global or slow analysis. The results are cached later for a fast 170 // transformation pass. When the Phase object is deleted the cached analysis 171 // results are deleted. 172 class PhaseTransform : public Phase { 173 protected: 174 Arena* _arena; 175 Node_List _nodes; // Map old node indices to new nodes. 176 Type_Array _types; // Map old node indices to Types. 177 178 // ConNode caches: 179 enum { _icon_min = -1 * HeapWordSize, 180 _icon_max = 16 * HeapWordSize, 181 _lcon_min = _icon_min, 182 _lcon_max = _icon_max, 183 _zcon_max = (uint)T_CONFLICT 184 }; 185 ConINode* _icons[_icon_max - _icon_min + 1]; // cached jint constant nodes 186 ConLNode* _lcons[_lcon_max - _lcon_min + 1]; // cached jlong constant nodes 187 ConNode* _zcons[_zcon_max + 1]; // cached is_zero_type nodes 188 void init_con_caches(); 189 190 // Support both int and long caches because either might be an intptr_t, 191 // so they show up frequently in address computations. 192 193 public: 194 PhaseTransform( PhaseNumber pnum ); 195 PhaseTransform( Arena *arena, PhaseNumber pnum ); 196 PhaseTransform( PhaseTransform *phase, PhaseNumber pnum ); 197 198 Arena* arena() { return _arena; } 199 Type_Array& types() { return _types; } 200 void replace_types(Type_Array new_types) { 201 _types = new_types; 202 } 203 // _nodes is used in varying ways by subclasses, which define local accessors 204 uint nodes_size() { 205 return _nodes.size(); 206 } 207 208 public: 209 // Get a previously recorded type for the node n. 210 // This type must already have been recorded. 211 // If you want the type of a very new (untransformed) node, 212 // you must use type_or_null, and test the result for NULL. 213 const Type* type(const Node* n) const { 214 assert(n != NULL, "must not be null"); 215 const Type* t = _types.fast_lookup(n->_idx); 216 assert(t != NULL, "must set before get"); 217 return t; 218 } 219 // Get a previously recorded type for the node n, 220 // or else return NULL if there is none. 221 const Type* type_or_null(const Node* n) const { 222 return _types.fast_lookup(n->_idx); 223 } 224 // Record a type for a node. 225 void set_type(const Node* n, const Type *t) { 226 assert(t != NULL, "type must not be null"); 227 _types.map(n->_idx, t); 228 } 229 // Record an initial type for a node, the node's bottom type. 230 void set_type_bottom(const Node* n) { 231 // Use this for initialization when bottom_type() (or better) is not handy. 232 // Usually the initialization shoudl be to n->Value(this) instead, 233 // or a hand-optimized value like Type::MEMORY or Type::CONTROL. 234 assert(_types[n->_idx] == NULL, "must set the initial type just once"); 235 _types.map(n->_idx, n->bottom_type()); 236 } 237 // Make sure the types array is big enough to record a size for the node n. 238 // (In product builds, we never want to do range checks on the types array!) 239 void ensure_type_or_null(const Node* n) { 240 if (n->_idx >= _types.Size()) 241 _types.map(n->_idx, NULL); // Grow the types array as needed. 242 } 243 244 // Utility functions: 245 const TypeInt* find_int_type( Node* n); 246 const TypeLong* find_long_type(Node* n); 247 jint find_int_con( Node* n, jint value_if_unknown) { 248 const TypeInt* t = find_int_type(n); 249 return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown; 250 } 251 jlong find_long_con(Node* n, jlong value_if_unknown) { 252 const TypeLong* t = find_long_type(n); 253 return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown; 254 } 255 256 // Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc. 257 // Same as transform(ConNode::make(t)). 258 ConNode* makecon(const Type* t); 259 virtual ConNode* uncached_makecon(const Type* t) // override in PhaseValues 260 { ShouldNotCallThis(); return NULL; } 261 262 // Fast int or long constant. Same as TypeInt::make(i) or TypeLong::make(l). 263 ConINode* intcon(jint i); 264 ConLNode* longcon(jlong l); 265 266 // Fast zero or null constant. Same as makecon(Type::get_zero_type(bt)). 267 ConNode* zerocon(BasicType bt); 268 269 // Return a node which computes the same function as this node, but 270 // in a faster or cheaper fashion. 271 virtual Node *transform( Node *n ) = 0; 272 273 // Return whether two Nodes are equivalent. 274 // Must not be recursive, since the recursive version is built from this. 275 // For pessimistic optimizations this is simply pointer equivalence. 276 bool eqv(const Node* n1, const Node* n2) const { return n1 == n2; } 277 278 // For pessimistic passes, the return type must monotonically narrow. 279 // For optimistic passes, the return type must monotonically widen. 280 // It is possible to get into a "death march" in either type of pass, 281 // where the types are continually moving but it will take 2**31 or 282 // more steps to converge. This doesn't happen on most normal loops. 283 // 284 // Here is an example of a deadly loop for an optimistic pass, along 285 // with a partial trace of inferred types: 286 // x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L; 287 // 0 1 join([0..max], 1) 288 // [0..1] [1..2] join([0..max], [1..2]) 289 // [0..2] [1..3] join([0..max], [1..3]) 290 // ... ... ... 291 // [0..max] [min]u[1..max] join([0..max], [min..max]) 292 // [0..max] ==> fixpoint 293 // We would have proven, the hard way, that the iteration space is all 294 // non-negative ints, with the loop terminating due to 32-bit overflow. 295 // 296 // Here is the corresponding example for a pessimistic pass: 297 // x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L; 298 // int int join([0..max], int) 299 // [0..max] [-1..max-1] join([0..max], [-1..max-1]) 300 // [0..max-1] [-1..max-2] join([0..max], [-1..max-2]) 301 // ... ... ... 302 // [0..1] [-1..0] join([0..max], [-1..0]) 303 // 0 -1 join([0..max], -1) 304 // 0 == fixpoint 305 // We would have proven, the hard way, that the iteration space is {0}. 306 // (Usually, other optimizations will make the "if (x >= 0)" fold up 307 // before we get into trouble. But not always.) 308 // 309 // It's a pleasant thing to observe that the pessimistic pass 310 // will make short work of the optimistic pass's deadly loop, 311 // and vice versa. That is a good example of the complementary 312 // purposes of the CCP (optimistic) vs. GVN (pessimistic) phases. 313 // 314 // In any case, only widen or narrow a few times before going to the 315 // correct flavor of top or bottom. 316 // 317 // This call only needs to be made once as the data flows around any 318 // given cycle. We do it at Phis, and nowhere else. 319 // The types presented are the new type of a phi (computed by PhiNode::Value) 320 // and the previously computed type, last time the phi was visited. 321 // 322 // The third argument is upper limit for the saturated value, 323 // if the phase wishes to widen the new_type. 324 // If the phase is narrowing, the old type provides a lower limit. 325 // Caller guarantees that old_type and new_type are no higher than limit_type. 326 virtual const Type* saturate(const Type* new_type, const Type* old_type, 327 const Type* limit_type) const 328 { ShouldNotCallThis(); return NULL; } 329 330 // Delayed node rehash if this is an IGVN phase 331 virtual void igvn_rehash_node_delayed(Node* n) {} 332 333 // true if CFG node d dominates CFG node n 334 virtual bool is_dominator(Node *d, Node *n) { fatal("unimplemented for this pass"); return false; }; 335 336 #ifndef PRODUCT 337 void dump_old2new_map() const; 338 void dump_new( uint new_lidx ) const; 339 void dump_types() const; 340 void dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl = true); 341 void dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited); 342 343 uint _count_progress; // For profiling, count transforms that make progress 344 void set_progress() { ++_count_progress; assert( allow_progress(),"No progress allowed during verification"); } 345 void clear_progress() { _count_progress = 0; } 346 uint made_progress() const { return _count_progress; } 347 348 uint _count_transforms; // For profiling, count transforms performed 349 void set_transforms() { ++_count_transforms; } 350 void clear_transforms() { _count_transforms = 0; } 351 uint made_transforms() const{ return _count_transforms; } 352 353 bool _allow_progress; // progress not allowed during verification pass 354 void set_allow_progress(bool allow) { _allow_progress = allow; } 355 bool allow_progress() { return _allow_progress; } 356 #endif 357 }; 358 359 //------------------------------PhaseValues------------------------------------ 360 // Phase infrastructure to support values 361 class PhaseValues : public PhaseTransform { 362 protected: 363 NodeHash _table; // Hash table for value-numbering 364 365 public: 366 PhaseValues( Arena *arena, uint est_max_size ); 367 PhaseValues( PhaseValues *pt ); 368 PhaseValues( PhaseValues *ptv, const char *dummy ); 369 NOT_PRODUCT( ~PhaseValues(); ) 370 virtual PhaseIterGVN *is_IterGVN() { return 0; } 371 372 // Some Ideal and other transforms delete --> modify --> insert values 373 bool hash_delete(Node *n) { return _table.hash_delete(n); } 374 void hash_insert(Node *n) { _table.hash_insert(n); } 375 Node *hash_find_insert(Node *n){ return _table.hash_find_insert(n); } 376 Node *hash_find(const Node *n) { return _table.hash_find(n); } 377 378 // Used after parsing to eliminate values that are no longer in program 379 void remove_useless_nodes(VectorSet &useful) { 380 _table.remove_useless_nodes(useful); 381 // this may invalidate cached cons so reset the cache 382 init_con_caches(); 383 } 384 385 virtual ConNode* uncached_makecon(const Type* t); // override from PhaseTransform 386 387 virtual const Type* saturate(const Type* new_type, const Type* old_type, 388 const Type* limit_type) const 389 { return new_type; } 390 391 #ifndef PRODUCT 392 uint _count_new_values; // For profiling, count new values produced 393 void inc_new_values() { ++_count_new_values; } 394 void clear_new_values() { _count_new_values = 0; } 395 uint made_new_values() const { return _count_new_values; } 396 #endif 397 }; 398 399 400 //------------------------------PhaseGVN--------------------------------------- 401 // Phase for performing local, pessimistic GVN-style optimizations. 402 class PhaseGVN : public PhaseValues { 403 protected: 404 bool is_dominator_helper(Node *d, Node *n, bool linear_only); 405 406 public: 407 PhaseGVN( Arena *arena, uint est_max_size ) : PhaseValues( arena, est_max_size ) {} 408 PhaseGVN( PhaseGVN *gvn ) : PhaseValues( gvn ) {} 409 PhaseGVN( PhaseGVN *gvn, const char *dummy ) : PhaseValues( gvn, dummy ) {} 410 411 // Return a node which computes the same function as this node, but 412 // in a faster or cheaper fashion. 413 Node *transform( Node *n ); 414 Node *transform_no_reclaim( Node *n ); 415 virtual void record_for_igvn(Node *n) { 416 C->record_for_igvn(n); 417 } 418 419 void replace_with(PhaseGVN* gvn) { 420 _table.replace_with(&gvn->_table); 421 _types = gvn->_types; 422 } 423 424 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, true); } 425 426 // Check for a simple dead loop when a data node references itself. 427 DEBUG_ONLY(void dead_loop_check(Node *n);) 428 }; 429 430 //------------------------------PhaseIterGVN----------------------------------- 431 // Phase for iteratively performing local, pessimistic GVN-style optimizations. 432 // and ideal transformations on the graph. 433 class PhaseIterGVN : public PhaseGVN { 434 private: 435 bool _delay_transform; // When true simply register the node when calling transform 436 // instead of actually optimizing it 437 438 // Idealize old Node 'n' with respect to its inputs and its value 439 virtual Node *transform_old( Node *a_node ); 440 441 // Subsume users of node 'old' into node 'nn' 442 void subsume_node( Node *old, Node *nn ); 443 444 Node_Stack _stack; // Stack used to avoid recursion 445 446 protected: 447 448 // Warm up hash table, type table and initial worklist 449 void init_worklist( Node *a_root ); 450 451 virtual const Type* saturate(const Type* new_type, const Type* old_type, 452 const Type* limit_type) const; 453 // Usually returns new_type. Returns old_type if new_type is only a slight 454 // improvement, such that it would take many (>>10) steps to reach 2**32. 455 456 public: 457 PhaseIterGVN( PhaseIterGVN *igvn ); // Used by CCP constructor 458 PhaseIterGVN( PhaseGVN *gvn ); // Used after Parser 459 PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ); // Used after +VerifyOpto 460 461 // Idealize new Node 'n' with respect to its inputs and its value 462 virtual Node *transform( Node *a_node ); 463 virtual void record_for_igvn(Node *n) { } 464 465 virtual PhaseIterGVN *is_IterGVN() { return this; } 466 467 Unique_Node_List _worklist; // Iterative worklist 468 469 // Given def-use info and an initial worklist, apply Node::Ideal, 470 // Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU 471 // and dominator info to a fixed point. 472 void optimize(); 473 474 #ifndef PRODUCT 475 void trace_PhaseIterGVN(Node* n, Node* nn, const Type* old_type); 476 void init_verifyPhaseIterGVN(); 477 void verify_PhaseIterGVN(); 478 #endif 479 480 #ifdef ASSERT 481 void dump_infinite_loop_info(Node* n); 482 void trace_PhaseIterGVN_verbose(Node* n, int num_processed); 483 #endif 484 485 // Register a new node with the iter GVN pass without transforming it. 486 // Used when we need to restructure a Region/Phi area and all the Regions 487 // and Phis need to complete this one big transform before any other 488 // transforms can be triggered on the region. 489 // Optional 'orig' is an earlier version of this node. 490 // It is significant only for debugging and profiling. 491 Node* register_new_node_with_optimizer(Node* n, Node* orig = NULL); 492 493 // Kill a globally dead Node. All uses are also globally dead and are 494 // aggressively trimmed. 495 void remove_globally_dead_node( Node *dead ); 496 497 // Kill all inputs to a dead node, recursively making more dead nodes. 498 // The Node must be dead locally, i.e., have no uses. 499 void remove_dead_node( Node *dead ) { 500 assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead"); 501 remove_globally_dead_node(dead); 502 } 503 504 // Add users of 'n' to worklist 505 void add_users_to_worklist0( Node *n ); 506 void add_users_to_worklist ( Node *n ); 507 508 // Replace old node with new one. 509 void replace_node( Node *old, Node *nn ) { 510 add_users_to_worklist(old); 511 hash_delete(old); // Yank from hash before hacking edges 512 subsume_node(old, nn); 513 } 514 515 // Delayed node rehash: remove a node from the hash table and rehash it during 516 // next optimizing pass 517 void rehash_node_delayed(Node* n) { 518 hash_delete(n); 519 _worklist.push(n); 520 } 521 522 void igvn_rehash_node_delayed(Node* n) { 523 rehash_node_delayed(n); 524 } 525 526 // Replace ith edge of "n" with "in" 527 void replace_input_of(Node* n, int i, Node* in) { 528 rehash_node_delayed(n); 529 n->set_req(i, in); 530 } 531 532 // Delete ith edge of "n" 533 void delete_input_of(Node* n, int i) { 534 rehash_node_delayed(n); 535 n->del_req(i); 536 } 537 538 bool delay_transform() const { return _delay_transform; } 539 540 void set_delay_transform(bool delay) { 541 _delay_transform = delay; 542 } 543 544 // Clone loop predicates. Defined in loopTransform.cpp. 545 Node* clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check); 546 // Create a new if below new_entry for the predicate to be cloned 547 ProjNode* create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, 548 Deoptimization::DeoptReason reason, 549 Opcodes opcode); 550 551 void remove_speculative_types(); 552 void check_no_speculative_types() { 553 _table.check_no_speculative_types(); 554 } 555 556 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, false); } 557 558 #ifndef PRODUCT 559 protected: 560 // Sub-quadratic implementation of VerifyIterativeGVN. 561 julong _verify_counter; 562 julong _verify_full_passes; 563 enum { _verify_window_size = 30 }; 564 Node* _verify_window[_verify_window_size]; 565 void verify_step(Node* n); 566 #endif 567 }; 568 569 //------------------------------PhaseCCP--------------------------------------- 570 // Phase for performing global Conditional Constant Propagation. 571 // Should be replaced with combined CCP & GVN someday. 572 class PhaseCCP : public PhaseIterGVN { 573 // Non-recursive. Use analysis to transform single Node. 574 virtual Node *transform_once( Node *n ); 575 576 public: 577 PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants 578 NOT_PRODUCT( ~PhaseCCP(); ) 579 580 // Worklist algorithm identifies constants 581 void analyze(); 582 // Recursive traversal of program. Used analysis to modify program. 583 virtual Node *transform( Node *n ); 584 // Do any transformation after analysis 585 void do_transform(); 586 587 virtual const Type* saturate(const Type* new_type, const Type* old_type, 588 const Type* limit_type) const; 589 // Returns new_type->widen(old_type), which increments the widen bits until 590 // giving up with TypeInt::INT or TypeLong::LONG. 591 // Result is clipped to limit_type if necessary. 592 593 #ifndef PRODUCT 594 static uint _total_invokes; // For profiling, count invocations 595 void inc_invokes() { ++PhaseCCP::_total_invokes; } 596 597 static uint _total_constants; // For profiling, count constants found 598 uint _count_constants; 599 void clear_constants() { _count_constants = 0; } 600 void inc_constants() { ++_count_constants; } 601 uint count_constants() const { return _count_constants; } 602 603 static void print_statistics(); 604 #endif 605 }; 606 607 608 //------------------------------PhasePeephole---------------------------------- 609 // Phase for performing peephole optimizations on register allocated basic blocks. 610 class PhasePeephole : public PhaseTransform { 611 PhaseRegAlloc *_regalloc; 612 PhaseCFG &_cfg; 613 // Recursive traversal of program. Pure function is unused in this phase 614 virtual Node *transform( Node *n ); 615 616 public: 617 PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg ); 618 NOT_PRODUCT( ~PhasePeephole(); ) 619 620 // Do any transformation after analysis 621 void do_transform(); 622 623 #ifndef PRODUCT 624 static uint _total_peepholes; // For profiling, count peephole rules applied 625 uint _count_peepholes; 626 void clear_peepholes() { _count_peepholes = 0; } 627 void inc_peepholes() { ++_count_peepholes; } 628 uint count_peepholes() const { return _count_peepholes; } 629 630 static void print_statistics(); 631 #endif 632 }; 633 634 #endif // SHARE_VM_OPTO_PHASEX_HPP