1 /*
2 * Copyright (c) 1997, 2021, 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
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7 * published by the Free Software Foundation.
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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).
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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
36 class BarrierSetC2;
37 class Compile;
38 class ConINode;
39 class ConLNode;
40 class Node;
41 class Type;
42 class PhaseTransform;
43 class PhaseGVN;
44 class PhaseIterGVN;
45 class PhaseCCP;
46 class PhasePeephole;
47 class PhaseRegAlloc;
48
49
50 //-----------------------------------------------------------------------------
51 // Expandable closed hash-table of nodes, initialized to NULL.
52 // Note that the constructor just zeros things
53 // Storage is reclaimed when the Arena's lifetime is over.
54 class NodeHash : public StackObj {
55 protected:
56 Arena *_a; // Arena to allocate in
57 uint _max; // Size of table (power of 2)
58 uint _inserts; // For grow and debug, count of hash_inserts
59 uint _insert_limit; // 'grow' when _inserts reaches _insert_limit
60 Node **_table; // Hash table of Node pointers
61 Node *_sentinel; // Replaces deleted entries in hash table
62
63 public:
64 NodeHash(uint est_max_size);
65 NodeHash(Arena *arena, uint est_max_size);
66 NodeHash(NodeHash *use_this_state);
67 #ifdef ASSERT
68 ~NodeHash(); // Unlock all nodes upon destruction of table.
69 void operator=(const NodeHash&); // Unlock all nodes upon replacement of table.
70 #endif
71 Node *hash_find(const Node*);// Find an equivalent version in hash table
72 Node *hash_find_insert(Node*);// If not in table insert else return found node
73 void hash_insert(Node*); // Insert into hash table
74 bool hash_delete(const Node*);// Replace with _sentinel in hash table
75 void check_grow() {
76 _inserts++;
77 if( _inserts == _insert_limit ) { grow(); }
78 assert( _inserts <= _insert_limit, "hash table overflow");
79 assert( _inserts < _max, "hash table overflow" );
80 }
81 static uint round_up(uint); // Round up to nearest power of 2
82 void grow(); // Grow _table to next power of 2 and rehash
83 // Return 75% of _max, rounded up.
84 uint insert_limit() const { return _max - (_max>>2); }
85
86 void clear(); // Set all entries to NULL, keep storage.
87 // Size of hash table
88 uint size() const { return _max; }
89 // Return Node* at index in table
90 Node *at(uint table_index) {
91 assert(table_index < _max, "Must be within table");
92 return _table[table_index];
93 }
94
95 void remove_useless_nodes(VectorSet& useful); // replace with sentinel
96 void replace_with(NodeHash* nh);
97 void check_no_speculative_types(); // Check no speculative part for type nodes in table
98
99 Node *sentinel() { return _sentinel; }
100
101 #ifndef PRODUCT
102 Node *find_index(uint idx); // For debugging
103 void dump(); // For debugging, dump statistics
104 uint _grows; // For debugging, count of table grow()s
105 uint _look_probes; // For debugging, count of hash probes
106 uint _lookup_hits; // For debugging, count of hash_finds
107 uint _lookup_misses; // For debugging, count of hash_finds
108 uint _insert_probes; // For debugging, count of hash probes
109 uint _delete_probes; // For debugging, count of hash probes for deletes
110 uint _delete_hits; // For debugging, count of hash probes for deletes
111 uint _delete_misses; // For debugging, count of hash probes for deletes
112 uint _total_inserts; // For debugging, total inserts into hash table
113 uint _total_insert_probes; // For debugging, total probes while inserting
114 #endif
115 };
116
117
118 //-----------------------------------------------------------------------------
119 // Map dense integer indices to Types. Uses classic doubling-array trick.
120 // Abstractly provides an infinite array of Type*'s, initialized to NULL.
121 // Note that the constructor just zeros things, and since I use Arena
122 // allocation I do not need a destructor to reclaim storage.
123 // Despite the general name, this class is customized for use by PhaseTransform.
124 class Type_Array : public StackObj {
125 Arena *_a; // Arena to allocate in
126 uint _max;
127 const Type **_types;
128 void grow( uint i ); // Grow array node to fit
129 const Type *operator[] ( uint i ) const // Lookup, or NULL for not mapped
130 { return (i<_max) ? _types[i] : (Type*)NULL; }
131 friend class PhaseTransform;
132 public:
133 Type_Array(Arena *a) : _a(a), _max(0), _types(0) {}
134 Type_Array(Type_Array *ta) : _a(ta->_a), _max(ta->_max), _types(ta->_types) { }
135 const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];}
136 // Extend the mapping: index i maps to Type *n.
137 void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; }
138 uint Size() const { return _max; }
139 #ifndef PRODUCT
140 void dump() const;
141 #endif
142 };
143
144
145 //------------------------------PhaseRemoveUseless-----------------------------
146 // Remove useless nodes from GVN hash-table, worklist, and graph
147 class PhaseRemoveUseless : public Phase {
148 protected:
149 Unique_Node_List _useful; // Nodes reachable from root
150 // list is allocated from current resource area
151 public:
152 PhaseRemoveUseless(PhaseGVN *gvn, Unique_Node_List *worklist, PhaseNumber phase_num = Remove_Useless);
153
154 Unique_Node_List *get_useful() { return &_useful; }
155 };
156
157 //------------------------------PhaseRenumber----------------------------------
158 // Phase that first performs a PhaseRemoveUseless, then it renumbers compiler
159 // structures accordingly.
160 class PhaseRenumberLive : public PhaseRemoveUseless {
161 protected:
162 Type_Array _new_type_array; // Storage for the updated type information.
163 GrowableArray<int> _old2new_map;
164 Node_List _delayed;
165 bool _is_pass_finished;
166 uint _live_node_count;
167
168 int update_embedded_ids(Node* n);
169 int new_index(int old_idx);
170
171 public:
172 PhaseRenumberLive(PhaseGVN* gvn,
173 Unique_Node_List* worklist, Unique_Node_List* new_worklist,
174 PhaseNumber phase_num = Remove_Useless_And_Renumber_Live);
175 };
176
177
178 //------------------------------PhaseTransform---------------------------------
179 // Phases that analyze, then transform. Constructing the Phase object does any
180 // global or slow analysis. The results are cached later for a fast
181 // transformation pass. When the Phase object is deleted the cached analysis
182 // results are deleted.
183 class PhaseTransform : public Phase {
184 protected:
185 Arena* _arena;
186 Node_List _nodes; // Map old node indices to new nodes.
187 Type_Array _types; // Map old node indices to Types.
188
189 // ConNode caches:
190 enum { _icon_min = -1 * HeapWordSize,
191 _icon_max = 16 * HeapWordSize,
192 _lcon_min = _icon_min,
193 _lcon_max = _icon_max,
194 _zcon_max = (uint)T_CONFLICT
195 };
196 ConINode* _icons[_icon_max - _icon_min + 1]; // cached jint constant nodes
197 ConLNode* _lcons[_lcon_max - _lcon_min + 1]; // cached jlong constant nodes
198 ConNode* _zcons[_zcon_max + 1]; // cached is_zero_type nodes
199 void init_con_caches();
200
201 // Support both int and long caches because either might be an intptr_t,
202 // so they show up frequently in address computations.
203
204 public:
205 PhaseTransform( PhaseNumber pnum );
206 PhaseTransform( Arena *arena, PhaseNumber pnum );
207 PhaseTransform( PhaseTransform *phase, PhaseNumber pnum );
208
209 Arena* arena() { return _arena; }
210 Type_Array& types() { return _types; }
211 void replace_types(Type_Array new_types) {
212 _types = new_types;
213 }
214 // _nodes is used in varying ways by subclasses, which define local accessors
215 uint nodes_size() {
216 return _nodes.size();
217 }
218
219 public:
220 // Get a previously recorded type for the node n.
221 // This type must already have been recorded.
222 // If you want the type of a very new (untransformed) node,
223 // you must use type_or_null, and test the result for NULL.
224 const Type* type(const Node* n) const {
225 assert(_pnum != Ideal_Loop, "should not be used from PhaseIdealLoop");
226 assert(n != NULL, "must not be null");
227 const Type* t = _types.fast_lookup(n->_idx);
228 assert(t != NULL, "must set before get");
229 return t;
230 }
231 // Get a previously recorded type for the node n,
232 // or else return NULL if there is none.
233 const Type* type_or_null(const Node* n) const {
234 assert(_pnum != Ideal_Loop, "should not be used from PhaseIdealLoop");
235 return _types.fast_lookup(n->_idx);
236 }
237 // Record a type for a node.
238 void set_type(const Node* n, const Type *t) {
239 assert(t != NULL, "type must not be null");
240 _types.map(n->_idx, t);
241 }
242 // Record an initial type for a node, the node's bottom type.
243 void set_type_bottom(const Node* n) {
244 // Use this for initialization when bottom_type() (or better) is not handy.
245 // Usually the initialization should be to n->Value(this) instead,
246 // or a hand-optimized value like Type::MEMORY or Type::CONTROL.
247 assert(_types[n->_idx] == NULL, "must set the initial type just once");
248 _types.map(n->_idx, n->bottom_type());
249 }
250 // Make sure the types array is big enough to record a size for the node n.
251 // (In product builds, we never want to do range checks on the types array!)
252 void ensure_type_or_null(const Node* n) {
253 if (n->_idx >= _types.Size())
254 _types.map(n->_idx, NULL); // Grow the types array as needed.
255 }
256
257 // Utility functions:
258 const TypeInt* find_int_type( Node* n);
259 const TypeLong* find_long_type(Node* n);
260 jint find_int_con( Node* n, jint value_if_unknown) {
261 const TypeInt* t = find_int_type(n);
262 return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
263 }
264 jlong find_long_con(Node* n, jlong value_if_unknown) {
265 const TypeLong* t = find_long_type(n);
266 return (t != NULL && t->is_con()) ? t->get_con() : value_if_unknown;
267 }
268
269 // Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc.
270 // Same as transform(ConNode::make(t)).
271 ConNode* makecon(const Type* t);
272 virtual ConNode* uncached_makecon(const Type* t) // override in PhaseValues
273 { ShouldNotCallThis(); return NULL; }
274
275 // Fast int or long constant. Same as TypeInt::make(i) or TypeLong::make(l).
276 ConINode* intcon(jint i);
277 ConLNode* longcon(jlong l);
278 ConNode* integercon(jlong l, BasicType bt);
279
280 // Fast zero or null constant. Same as makecon(Type::get_zero_type(bt)).
281 ConNode* zerocon(BasicType bt);
282
283 // Return a node which computes the same function as this node, but
284 // in a faster or cheaper fashion.
285 virtual Node *transform( Node *n ) = 0;
286
287 // For pessimistic passes, the return type must monotonically narrow.
288 // For optimistic passes, the return type must monotonically widen.
289 // It is possible to get into a "death march" in either type of pass,
290 // where the types are continually moving but it will take 2**31 or
291 // more steps to converge. This doesn't happen on most normal loops.
292 //
293 // Here is an example of a deadly loop for an optimistic pass, along
294 // with a partial trace of inferred types:
295 // x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L;
296 // 0 1 join([0..max], 1)
297 // [0..1] [1..2] join([0..max], [1..2])
298 // [0..2] [1..3] join([0..max], [1..3])
299 // ... ... ...
300 // [0..max] [min]u[1..max] join([0..max], [min..max])
301 // [0..max] ==> fixpoint
302 // We would have proven, the hard way, that the iteration space is all
303 // non-negative ints, with the loop terminating due to 32-bit overflow.
304 //
305 // Here is the corresponding example for a pessimistic pass:
306 // x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L;
307 // int int join([0..max], int)
308 // [0..max] [-1..max-1] join([0..max], [-1..max-1])
309 // [0..max-1] [-1..max-2] join([0..max], [-1..max-2])
310 // ... ... ...
311 // [0..1] [-1..0] join([0..max], [-1..0])
312 // 0 -1 join([0..max], -1)
313 // 0 == fixpoint
314 // We would have proven, the hard way, that the iteration space is {0}.
315 // (Usually, other optimizations will make the "if (x >= 0)" fold up
316 // before we get into trouble. But not always.)
317 //
318 // It's a pleasant thing to observe that the pessimistic pass
319 // will make short work of the optimistic pass's deadly loop,
320 // and vice versa. That is a good example of the complementary
321 // purposes of the CCP (optimistic) vs. GVN (pessimistic) phases.
322 //
323 // In any case, only widen or narrow a few times before going to the
324 // correct flavor of top or bottom.
325 //
326 // This call only needs to be made once as the data flows around any
327 // given cycle. We do it at Phis, and nowhere else.
328 // The types presented are the new type of a phi (computed by PhiNode::Value)
329 // and the previously computed type, last time the phi was visited.
330 //
331 // The third argument is upper limit for the saturated value,
332 // if the phase wishes to widen the new_type.
333 // If the phase is narrowing, the old type provides a lower limit.
334 // Caller guarantees that old_type and new_type are no higher than limit_type.
335 virtual const Type* saturate(const Type* new_type, const Type* old_type,
336 const Type* limit_type) const
337 { ShouldNotCallThis(); return NULL; }
338
339 // true if CFG node d dominates CFG node n
340 virtual bool is_dominator(Node *d, Node *n) { fatal("unimplemented for this pass"); return false; };
341
342 #ifndef PRODUCT
343 void dump_old2new_map() const;
344 void dump_new( uint new_lidx ) const;
345 void dump_types() const;
346 void dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl = true);
347 void dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited);
348
349 uint _count_progress; // For profiling, count transforms that make progress
350 void set_progress() { ++_count_progress; assert( allow_progress(),"No progress allowed during verification"); }
351 void clear_progress() { _count_progress = 0; }
352 uint made_progress() const { return _count_progress; }
353
354 uint _count_transforms; // For profiling, count transforms performed
355 void set_transforms() { ++_count_transforms; }
356 void clear_transforms() { _count_transforms = 0; }
357 uint made_transforms() const{ return _count_transforms; }
358
359 bool _allow_progress; // progress not allowed during verification pass
360 void set_allow_progress(bool allow) { _allow_progress = allow; }
361 bool allow_progress() { return _allow_progress; }
362 #endif
363 };
364
365 //------------------------------PhaseValues------------------------------------
366 // Phase infrastructure to support values
367 class PhaseValues : public PhaseTransform {
368 protected:
369 NodeHash _table; // Hash table for value-numbering
370 bool _iterGVN;
371 public:
372 PhaseValues(Arena* arena, uint est_max_size);
373 PhaseValues(PhaseValues* pt);
374 NOT_PRODUCT(~PhaseValues();)
375 PhaseIterGVN* is_IterGVN() { return (_iterGVN) ? (PhaseIterGVN*)this : NULL; }
376
377 // Some Ideal and other transforms delete --> modify --> insert values
378 bool hash_delete(Node* n) { return _table.hash_delete(n); }
379 void hash_insert(Node* n) { _table.hash_insert(n); }
380 Node* hash_find_insert(Node* n){ return _table.hash_find_insert(n); }
381 Node* hash_find(const Node* n) { return _table.hash_find(n); }
382
383 // Used after parsing to eliminate values that are no longer in program
384 void remove_useless_nodes(VectorSet &useful) {
385 _table.remove_useless_nodes(useful);
386 // this may invalidate cached cons so reset the cache
387 init_con_caches();
388 }
389
390 virtual ConNode* uncached_makecon(const Type* t); // override from PhaseTransform
391
392 const Type* saturate(const Type* new_type, const Type* old_type,
393 const Type* limit_type) const
394 { return new_type; }
395
396 #ifndef PRODUCT
397 uint _count_new_values; // For profiling, count new values produced
398 void inc_new_values() { ++_count_new_values; }
399 void clear_new_values() { _count_new_values = 0; }
400 uint made_new_values() const { return _count_new_values; }
401 #endif
402 };
403
404
405 //------------------------------PhaseGVN---------------------------------------
406 // Phase for performing local, pessimistic GVN-style optimizations.
407 class PhaseGVN : public PhaseValues {
408 protected:
409 bool is_dominator_helper(Node *d, Node *n, bool linear_only);
410
411 public:
412 PhaseGVN( Arena *arena, uint est_max_size ) : PhaseValues( arena, est_max_size ) {}
413 PhaseGVN( PhaseGVN *gvn ) : PhaseValues( gvn ) {}
414
415 // Return a node which computes the same function as this node, but
416 // in a faster or cheaper fashion.
417 Node *transform( Node *n );
418 Node *transform_no_reclaim( Node *n );
419 virtual void record_for_igvn(Node *n) {
420 C->record_for_igvn(n);
421 }
422
423 void replace_with(PhaseGVN* gvn) {
424 _table.replace_with(&gvn->_table);
425 _types = gvn->_types;
426 }
427
428 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, true); }
429
430 // Helper to call Node::Ideal() and BarrierSetC2::ideal_node().
431 Node* apply_ideal(Node* i, bool can_reshape);
432
433 #ifdef ASSERT
434 void dump_infinite_loop_info(Node* n, const char* where);
435 // Check for a simple dead loop when a data node references itself.
436 void dead_loop_check(Node *n);
437 #endif
438 };
439
440 //------------------------------PhaseIterGVN-----------------------------------
441 // Phase for iteratively performing local, pessimistic GVN-style optimizations.
442 // and ideal transformations on the graph.
443 class PhaseIterGVN : public PhaseGVN {
444 private:
445 bool _delay_transform; // When true simply register the node when calling transform
446 // instead of actually optimizing it
447
448 // Idealize old Node 'n' with respect to its inputs and its value
449 virtual Node *transform_old( Node *a_node );
450
451 // Subsume users of node 'old' into node 'nn'
452 void subsume_node( Node *old, Node *nn );
453
454 Node_Stack _stack; // Stack used to avoid recursion
455 protected:
456
457 // Shuffle worklist, for stress testing
458 void shuffle_worklist();
459
460 virtual const Type* saturate(const Type* new_type, const Type* old_type,
461 const Type* limit_type) const;
462 // Usually returns new_type. Returns old_type if new_type is only a slight
463 // improvement, such that it would take many (>>10) steps to reach 2**32.
464
465 public:
466 PhaseIterGVN(PhaseIterGVN* igvn); // Used by CCP constructor
467 PhaseIterGVN(PhaseGVN* gvn); // Used after Parser
468
469 // Idealize new Node 'n' with respect to its inputs and its value
470 virtual Node *transform( Node *a_node );
471 virtual void record_for_igvn(Node *n) { }
472
473 Unique_Node_List _worklist; // Iterative worklist
474
475 // Given def-use info and an initial worklist, apply Node::Ideal,
476 // Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU
477 // and dominator info to a fixed point.
478 void optimize();
479
480 #ifndef PRODUCT
481 void trace_PhaseIterGVN(Node* n, Node* nn, const Type* old_type);
482 void init_verifyPhaseIterGVN();
483 void verify_PhaseIterGVN();
484 #endif
485
486 #ifdef ASSERT
487 void dump_infinite_loop_info(Node* n, const char* where);
488 void trace_PhaseIterGVN_verbose(Node* n, int num_processed);
489 #endif
490
491 // Register a new node with the iter GVN pass without transforming it.
492 // Used when we need to restructure a Region/Phi area and all the Regions
493 // and Phis need to complete this one big transform before any other
494 // transforms can be triggered on the region.
495 // Optional 'orig' is an earlier version of this node.
496 // It is significant only for debugging and profiling.
497 Node* register_new_node_with_optimizer(Node* n, Node* orig = NULL);
498
499 // Kill a globally dead Node. All uses are also globally dead and are
500 // aggressively trimmed.
501 void remove_globally_dead_node( Node *dead );
502
503 // Kill all inputs to a dead node, recursively making more dead nodes.
504 // The Node must be dead locally, i.e., have no uses.
505 void remove_dead_node( Node *dead ) {
506 assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead");
507 remove_globally_dead_node(dead);
508 }
509
510 // Add users of 'n' to worklist
511 void add_users_to_worklist0( Node *n );
512 void add_users_to_worklist ( Node *n );
513
514 // Replace old node with new one.
515 void replace_node( Node *old, Node *nn ) {
516 add_users_to_worklist(old);
517 hash_delete(old); // Yank from hash before hacking edges
518 subsume_node(old, nn);
519 }
520
521 // Delayed node rehash: remove a node from the hash table and rehash it during
522 // next optimizing pass
523 void rehash_node_delayed(Node* n) {
524 hash_delete(n);
525 _worklist.push(n);
526 }
527
528 // Replace ith edge of "n" with "in"
529 void replace_input_of(Node* n, int i, Node* in) {
530 rehash_node_delayed(n);
531 n->set_req_X(i, in, this);
532 }
533
534 // Add "in" as input (req) of "n"
535 void add_input_to(Node* n, Node* in) {
536 rehash_node_delayed(n);
537 n->add_req(in);
538 }
539
540 // Delete ith edge of "n"
541 void delete_input_of(Node* n, int i) {
542 rehash_node_delayed(n);
543 n->del_req(i);
544 }
545
546 // Delete precedence edge i of "n"
547 void delete_precedence_of(Node* n, int i) {
548 rehash_node_delayed(n);
549 n->rm_prec(i);
550 }
551
552 bool delay_transform() const { return _delay_transform; }
553
554 void set_delay_transform(bool delay) {
555 _delay_transform = delay;
556 }
557
558 void remove_speculative_types();
559 void check_no_speculative_types() {
560 _table.check_no_speculative_types();
561 }
562
563 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, false); }
564 bool no_dependent_zero_check(Node* n) const;
565
566 #ifndef PRODUCT
567 protected:
568 // Sub-quadratic implementation of VerifyIterativeGVN.
569 julong _verify_counter;
570 julong _verify_full_passes;
571 enum { _verify_window_size = 30 };
572 Node* _verify_window[_verify_window_size];
573 void verify_step(Node* n);
574 #endif
575 };
576
577 //------------------------------PhaseCCP---------------------------------------
578 // Phase for performing global Conditional Constant Propagation.
579 // Should be replaced with combined CCP & GVN someday.
580 class PhaseCCP : public PhaseIterGVN {
581 Unique_Node_List _root_and_safepoints;
582 // Non-recursive. Use analysis to transform single Node.
583 virtual Node* transform_once(Node* n);
584
585 Node* fetch_next_node(Unique_Node_List& worklist);
586 static void dump_type_and_node(const Node* n, const Type* t) PRODUCT_RETURN;
587
588 void push_child_nodes_to_worklist(Unique_Node_List& worklist, Node* n) const;
589 void push_if_not_bottom_type(Unique_Node_List& worklist, Node* n) const;
590 void push_more_uses(Unique_Node_List& worklist, Node* parent, const Node* use) const;
591 void push_phis(Unique_Node_List& worklist, const Node* use) const;
592 static void push_catch(Unique_Node_List& worklist, const Node* use);
593 void push_cmpu(Unique_Node_List& worklist, const Node* use) const;
594 static void push_counted_loop_phi(Unique_Node_List& worklist, Node* parent, const Node* use);
595 void push_loadp(Unique_Node_List& worklist, const Node* use) const;
596 static void push_load_barrier(Unique_Node_List& worklist, const BarrierSetC2* barrier_set, const Node* use);
597 void push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const;
598 void push_cast_ii(Unique_Node_List& worklist, const Node* parent, const Node* use) const;
599 void push_opaque_zero_trip_guard(Unique_Node_List& worklist, const Node* use) const;
600
601 public:
602 PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants
603 NOT_PRODUCT( ~PhaseCCP(); )
604
605 // Worklist algorithm identifies constants
606 void analyze();
607 #ifdef ASSERT
608 // For every node n on verify list, check if type(n) == n->Value()
609 void verify_analyze(Unique_Node_List& worklist_verify);
610 #endif
611 // Recursive traversal of program. Used analysis to modify program.
612 virtual Node *transform( Node *n );
613 // Do any transformation after analysis
614 void do_transform();
615
616 virtual const Type* saturate(const Type* new_type, const Type* old_type,
617 const Type* limit_type) const;
618 // Returns new_type->widen(old_type), which increments the widen bits until
619 // giving up with TypeInt::INT or TypeLong::LONG.
620 // Result is clipped to limit_type if necessary.
621
622 #ifndef PRODUCT
623 static uint _total_invokes; // For profiling, count invocations
624 void inc_invokes() { ++PhaseCCP::_total_invokes; }
625
626 static uint _total_constants; // For profiling, count constants found
627 uint _count_constants;
628 void clear_constants() { _count_constants = 0; }
629 void inc_constants() { ++_count_constants; }
630 uint count_constants() const { return _count_constants; }
631
632 static void print_statistics();
633 #endif
634 };
635
636
637 //------------------------------PhasePeephole----------------------------------
638 // Phase for performing peephole optimizations on register allocated basic blocks.
639 class PhasePeephole : public PhaseTransform {
640 PhaseRegAlloc *_regalloc;
641 PhaseCFG &_cfg;
642 // Recursive traversal of program. Pure function is unused in this phase
643 virtual Node *transform( Node *n );
644
645 public:
646 PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg );
647 NOT_PRODUCT( ~PhasePeephole(); )
648
649 // Do any transformation after analysis
650 void do_transform();
651
652 #ifndef PRODUCT
653 static uint _total_peepholes; // For profiling, count peephole rules applied
654 uint _count_peepholes;
655 void clear_peepholes() { _count_peepholes = 0; }
656 void inc_peepholes() { ++_count_peepholes; }
657 uint count_peepholes() const { return _count_peepholes; }
658
659 static void print_statistics();
660 #endif
661 };
662
663 #endif // SHARE_OPTO_PHASEX_HPP