1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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 public:
128 Type_Array(Arena *a) : _a(a), _max(0), _types(nullptr) {}
129 const Type *operator[] ( uint i ) const // Lookup, or null for not mapped
130 { return (i<_max) ? _types[i] : (Type*)nullptr; }
131 const Type *fast_lookup(uint i) const{assert(i<_max,"oob");return _types[i];}
132 // Extend the mapping: index i maps to Type *n.
133 void map( uint i, const Type *n ) { if( i>=_max ) grow(i); _types[i] = n; }
134 uint Size() const { return _max; }
135 #ifndef PRODUCT
136 void dump() const;
137 #endif
138 void swap(Type_Array &other) {
139 if (this != &other) {
140 assert(_a == other._a, "swapping for differing arenas is probably a bad idea");
141 ::swap(_max, other._max);
142 ::swap(_types, other._types);
143 }
144 }
145 NONCOPYABLE(Type_Array);
146 };
147
148
149 //------------------------------PhaseRemoveUseless-----------------------------
150 // Remove useless nodes from GVN hash-table, worklist, and graph
151 class PhaseRemoveUseless : public Phase {
152 protected:
153 Unique_Node_List _useful; // Nodes reachable from root
154 // list is allocated from current resource area
155 public:
156 PhaseRemoveUseless(PhaseGVN* gvn, Unique_Node_List& worklist, PhaseNumber phase_num = Remove_Useless);
157
158 Unique_Node_List *get_useful() { return &_useful; }
159 };
160
161 //------------------------------PhaseRenumber----------------------------------
162 // Phase that first performs a PhaseRemoveUseless, then it renumbers compiler
163 // structures accordingly.
164 class PhaseRenumberLive : public PhaseRemoveUseless {
165 protected:
166 Type_Array _new_type_array; // Storage for the updated type information.
167 GrowableArray<int> _old2new_map;
168 Node_List _delayed;
169 bool _is_pass_finished;
170 uint _live_node_count;
171
172 int update_embedded_ids(Node* n);
173 int new_index(int old_idx);
174
175 public:
176 PhaseRenumberLive(PhaseGVN* gvn,
177 Unique_Node_List& worklist,
178 PhaseNumber phase_num = Remove_Useless_And_Renumber_Live);
179 };
180
181
182 //------------------------------PhaseTransform---------------------------------
183 // Phases that analyze, then transform. Constructing the Phase object does any
184 // global or slow analysis. The results are cached later for a fast
185 // transformation pass. When the Phase object is deleted the cached analysis
186 // results are deleted.
187 class PhaseTransform : public Phase {
188 public:
189 PhaseTransform(PhaseNumber pnum) : Phase(pnum) {
190 #ifndef PRODUCT
191 clear_progress();
192 clear_transforms();
193 set_allow_progress(true);
194 #endif
195 }
196
197 // Return a node which computes the same function as this node, but
198 // in a faster or cheaper fashion.
199 virtual Node *transform( Node *n ) = 0;
200
201 // true if CFG node d dominates CFG node n
202 virtual bool is_dominator(Node *d, Node *n) { fatal("unimplemented for this pass"); return false; };
203
204 #ifndef PRODUCT
205 uint _count_progress; // For profiling, count transforms that make progress
206 void set_progress() { ++_count_progress; assert( allow_progress(),"No progress allowed during verification"); }
207 void clear_progress() { _count_progress = 0; }
208 uint made_progress() const { return _count_progress; }
209
210 uint _count_transforms; // For profiling, count transforms performed
211 void set_transforms() { ++_count_transforms; }
212 void clear_transforms() { _count_transforms = 0; }
213 uint made_transforms() const{ return _count_transforms; }
214
215 bool _allow_progress; // progress not allowed during verification pass
216 void set_allow_progress(bool allow) { _allow_progress = allow; }
217 bool allow_progress() { return _allow_progress; }
218 #endif
219 };
220
221 // Phase infrastructure required for Node::Value computations.
222 // 1) Type array, and accessor methods.
223 // 2) Constants cache, which requires access to the types.
224 // 3) NodeHash table, to find identical nodes (and remove/update the hash of a node on modification).
225 class PhaseValues : public PhaseTransform {
226 protected:
227 enum class PhaseValuesType {
228 gvn,
229 iter_gvn,
230 ccp
231 };
232
233 PhaseValuesType _phase;
234
235 // Hash table for value-numbering. Reference to "C->node_hash()",
236 NodeHash &_table;
237
238 // Type array mapping node idx to Type*. Reference to "C->types()".
239 Type_Array &_types;
240
241 // ConNode caches:
242 // Support both int and long caches because either might be an intptr_t,
243 // so they show up frequently in address computations.
244 enum { _icon_min = -1 * HeapWordSize,
245 _icon_max = 16 * HeapWordSize,
246 _lcon_min = _icon_min,
247 _lcon_max = _icon_max,
248 _zcon_max = (uint)T_CONFLICT
249 };
250 ConINode* _icons[_icon_max - _icon_min + 1]; // cached jint constant nodes
251 ConLNode* _lcons[_lcon_max - _lcon_min + 1]; // cached jlong constant nodes
252 ConNode* _zcons[_zcon_max + 1]; // cached is_zero_type nodes
253 void init_con_caches();
254
255 public:
256 PhaseValues() : PhaseTransform(GVN), _phase(PhaseValuesType::gvn),
257 _table(*C->node_hash()), _types(*C->types())
258 {
259 NOT_PRODUCT( clear_new_values(); )
260 // Force allocation for currently existing nodes
261 _types.map(C->unique(), nullptr);
262 init_con_caches();
263 }
264 NOT_PRODUCT(~PhaseValues();)
265 PhaseIterGVN* is_IterGVN();
266
267 // Some Ideal and other transforms delete --> modify --> insert values
268 bool hash_delete(Node* n) { return _table.hash_delete(n); }
269 void hash_insert(Node* n) { _table.hash_insert(n); }
270 Node* hash_find_insert(Node* n){ return _table.hash_find_insert(n); }
271 Node* hash_find(const Node* n) { return _table.hash_find(n); }
272
273 // Used after parsing to eliminate values that are no longer in program
274 void remove_useless_nodes(VectorSet &useful) {
275 _table.remove_useless_nodes(useful);
276 // this may invalidate cached cons so reset the cache
277 init_con_caches();
278 }
279
280 Type_Array& types() {
281 return _types;
282 }
283
284 // Get a previously recorded type for the node n.
285 // This type must already have been recorded.
286 // If you want the type of a very new (untransformed) node,
287 // you must use type_or_null, and test the result for null.
288 const Type* type(const Node* n) const {
289 assert(n != nullptr, "must not be null");
290 const Type* t = _types.fast_lookup(n->_idx);
291 assert(t != nullptr, "must set before get");
292 return t;
293 }
294 // Get a previously recorded type for the node n,
295 // or else return null if there is none.
296 const Type* type_or_null(const Node* n) const {
297 return _types.fast_lookup(n->_idx);
298 }
299 // Record a type for a node.
300 void set_type(const Node* n, const Type *t) {
301 assert(t != nullptr, "type must not be null");
302 _types.map(n->_idx, t);
303 }
304 void clear_type(const Node* n) {
305 if (n->_idx < _types.Size()) {
306 _types.map(n->_idx, nullptr);
307 }
308 }
309 // Record an initial type for a node, the node's bottom type.
310 void set_type_bottom(const Node* n) {
311 // Use this for initialization when bottom_type() (or better) is not handy.
312 // Usually the initialization should be to n->Value(this) instead,
313 // or a hand-optimized value like Type::MEMORY or Type::CONTROL.
314 assert(_types[n->_idx] == nullptr, "must set the initial type just once");
315 _types.map(n->_idx, n->bottom_type());
316 }
317 // Make sure the types array is big enough to record a size for the node n.
318 // (In product builds, we never want to do range checks on the types array!)
319 void ensure_type_or_null(const Node* n) {
320 if (n->_idx >= _types.Size())
321 _types.map(n->_idx, nullptr); // Grow the types array as needed.
322 }
323
324 // Utility functions:
325 const TypeInt* find_int_type( Node* n);
326 const TypeLong* find_long_type(Node* n);
327 jint find_int_con( Node* n, jint value_if_unknown) {
328 const TypeInt* t = find_int_type(n);
329 return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
330 }
331 jlong find_long_con(Node* n, jlong value_if_unknown) {
332 const TypeLong* t = find_long_type(n);
333 return (t != nullptr && t->is_con()) ? t->get_con() : value_if_unknown;
334 }
335
336 // Make an idealized constant, i.e., one of ConINode, ConPNode, ConFNode, etc.
337 // Same as transform(ConNode::make(t)).
338 ConNode* makecon(const Type* t);
339 ConNode* uncached_makecon(const Type* t);
340
341 // Fast int or long constant. Same as TypeInt::make(i) or TypeLong::make(l).
342 ConINode* intcon(jint i);
343 ConLNode* longcon(jlong l);
344 ConNode* integercon(jlong l, BasicType bt);
345
346 // Fast zero or null constant. Same as makecon(Type::get_zero_type(bt)).
347 ConNode* zerocon(BasicType bt);
348
349 // For pessimistic passes, the return type must monotonically narrow.
350 // For optimistic passes, the return type must monotonically widen.
351 // It is possible to get into a "death march" in either type of pass,
352 // where the types are continually moving but it will take 2**31 or
353 // more steps to converge. This doesn't happen on most normal loops.
354 //
355 // Here is an example of a deadly loop for an optimistic pass, along
356 // with a partial trace of inferred types:
357 // x = phi(0,x'); L: x' = x+1; if (x' >= 0) goto L;
358 // 0 1 join([0..max], 1)
359 // [0..1] [1..2] join([0..max], [1..2])
360 // [0..2] [1..3] join([0..max], [1..3])
361 // ... ... ...
362 // [0..max] [min]u[1..max] join([0..max], [min..max])
363 // [0..max] ==> fixpoint
364 // We would have proven, the hard way, that the iteration space is all
365 // non-negative ints, with the loop terminating due to 32-bit overflow.
366 //
367 // Here is the corresponding example for a pessimistic pass:
368 // x = phi(0,x'); L: x' = x-1; if (x' >= 0) goto L;
369 // int int join([0..max], int)
370 // [0..max] [-1..max-1] join([0..max], [-1..max-1])
371 // [0..max-1] [-1..max-2] join([0..max], [-1..max-2])
372 // ... ... ...
373 // [0..1] [-1..0] join([0..max], [-1..0])
374 // 0 -1 join([0..max], -1)
375 // 0 == fixpoint
376 // We would have proven, the hard way, that the iteration space is {0}.
377 // (Usually, other optimizations will make the "if (x >= 0)" fold up
378 // before we get into trouble. But not always.)
379 //
380 // It's a pleasant thing to observe that the pessimistic pass
381 // will make short work of the optimistic pass's deadly loop,
382 // and vice versa. That is a good example of the complementary
383 // purposes of the CCP (optimistic) vs. GVN (pessimistic) phases.
384 //
385 // In any case, only widen or narrow a few times before going to the
386 // correct flavor of top or bottom.
387 //
388 // This call only needs to be made once as the data flows around any
389 // given cycle. We do it at Phis, and nowhere else.
390 // The types presented are the new type of a phi (computed by PhiNode::Value)
391 // and the previously computed type, last time the phi was visited.
392 //
393 // The third argument is upper limit for the saturated value,
394 // if the phase wishes to widen the new_type.
395 // If the phase is narrowing, the old type provides a lower limit.
396 // Caller guarantees that old_type and new_type are no higher than limit_type.
397 virtual const Type* saturate(const Type* new_type,
398 const Type* old_type,
399 const Type* limit_type) const {
400 return new_type;
401 }
402 virtual const Type* saturate_and_maybe_push_to_igvn_worklist(const TypeNode* n, const Type* new_type) {
403 return saturate(new_type, type_or_null(n), n->type());
404 }
405
406 #ifndef PRODUCT
407 uint _count_new_values; // For profiling, count new values produced
408 void inc_new_values() { ++_count_new_values; }
409 void clear_new_values() { _count_new_values = 0; }
410 uint made_new_values() const { return _count_new_values; }
411 #endif
412 };
413
414
415 //------------------------------PhaseGVN---------------------------------------
416 // Phase for performing local, pessimistic GVN-style optimizations.
417 class PhaseGVN : public PhaseValues {
418 protected:
419 bool is_dominator_helper(Node *d, Node *n, bool linear_only);
420
421 public:
422 // Return a node which computes the same function as this node, but
423 // in a faster or cheaper fashion.
424 Node* transform(Node* n);
425
426 virtual void record_for_igvn(Node *n) {
427 C->record_for_igvn(n);
428 }
429
430 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, true); }
431
432 // Helper to call Node::Ideal() and BarrierSetC2::ideal_node().
433 Node* apply_ideal(Node* i, bool can_reshape);
434
435 #ifdef ASSERT
436 void dump_infinite_loop_info(Node* n, const char* where);
437 // Check for a simple dead loop when a data node references itself.
438 void dead_loop_check(Node *n);
439 #endif
440 };
441
442 //------------------------------PhaseIterGVN-----------------------------------
443 // Phase for iteratively performing local, pessimistic GVN-style optimizations.
444 // and ideal transformations on the graph.
445 class PhaseIterGVN : public PhaseGVN {
446 private:
447 bool _delay_transform; // When true simply register the node when calling transform
448 // instead of actually optimizing it
449
450 // Idealize old Node 'n' with respect to its inputs and its value
451 virtual Node *transform_old( Node *a_node );
452
453 // Subsume users of node 'old' into node 'nn'
454 void subsume_node( Node *old, Node *nn );
455
456 protected:
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
467 PhaseIterGVN(PhaseIterGVN* igvn); // Used by CCP constructor
468 PhaseIterGVN();
469
470 // Reset IGVN: call deconstructor, and placement new.
471 void reset() {
472 this->~PhaseIterGVN();
473 ::new (static_cast<void*>(this)) PhaseIterGVN();
474 }
475
476 // Reset IGVN with another: call deconstructor, and placement new.
477 // Achieves the same as the following (but without move constructors):
478 // igvn = PhaseIterGVN(other);
479 void reset_from_igvn(PhaseIterGVN* other) {
480 if (this != other) {
481 this->~PhaseIterGVN();
482 ::new (static_cast<void*>(this)) PhaseIterGVN(other);
483 }
484 }
485
486 // Idealize new Node 'n' with respect to its inputs and its value
487 virtual Node *transform( Node *a_node );
488 virtual void record_for_igvn(Node *n) { }
489
490 // Iterative worklist. Reference to "C->igvn_worklist()".
491 Unique_Node_List &_worklist;
492
493 // Given def-use info and an initial worklist, apply Node::Ideal,
494 // Node::Value, Node::Identity, hash-based value numbering, Node::Ideal_DU
495 // and dominator info to a fixed point.
496 void optimize();
497 #ifdef ASSERT
498 void verify_optimize();
499 void verify_Value_for(const Node* n, bool strict = false);
500 void verify_Ideal_for(Node* n, bool can_reshape);
501 void verify_Identity_for(Node* n);
502 void verify_node_invariants_for(const Node* n);
503 void verify_empty_worklist(Node* n);
504 #endif
505
506 #ifndef PRODUCT
507 void trace_PhaseIterGVN(Node* n, Node* nn, const Type* old_type);
508 void init_verifyPhaseIterGVN();
509 void verify_PhaseIterGVN();
510 #endif
511
512 #ifdef ASSERT
513 void dump_infinite_loop_info(Node* n, const char* where);
514 void trace_PhaseIterGVN_verbose(Node* n, int num_processed);
515 #endif
516
517 // Register a new node with the iter GVN pass without transforming it.
518 // Used when we need to restructure a Region/Phi area and all the Regions
519 // and Phis need to complete this one big transform before any other
520 // transforms can be triggered on the region.
521 // Optional 'orig' is an earlier version of this node.
522 // It is significant only for debugging and profiling.
523 Node* register_new_node_with_optimizer(Node* n, Node* orig = nullptr);
524
525 // Kill a globally dead Node. All uses are also globally dead and are
526 // aggressively trimmed.
527 void remove_globally_dead_node( Node *dead );
528
529 // Kill all inputs to a dead node, recursively making more dead nodes.
530 // The Node must be dead locally, i.e., have no uses.
531 void remove_dead_node( Node *dead ) {
532 assert(dead->outcnt() == 0 && !dead->is_top(), "node must be dead");
533 remove_globally_dead_node(dead);
534 }
535
536 // Add users of 'n' to worklist
537 static void add_users_to_worklist0(Node* n, Unique_Node_List& worklist);
538
539 // Add one or more users of 'use' to the worklist if it appears that a
540 // known optimization could be applied to those users.
541 // Node 'n' is a node that was modified or is about to get replaced,
542 // and 'use' is one use of 'n'.
543 // Certain optimizations have dependencies that extend beyond a node's
544 // direct inputs, so it is necessary to ensure the appropriate
545 // notifications are made here.
546 static void add_users_of_use_to_worklist(Node* n, Node* use, Unique_Node_List& worklist);
547
548 // Add users of 'n', and any other nodes that could be directly
549 // affected by changes to 'n', to the worklist.
550 // Node 'n' may be a node that is about to get replaced. In this
551 // case, 'n' should not be considered part of the new graph.
552 // Passing the old node (as 'n'), rather than the new node,
553 // prevents unnecessary notifications when the new node already
554 // has other users.
555 void add_users_to_worklist(Node* n);
556
557 // Replace old node with new one.
558 void replace_node( Node *old, Node *nn ) {
559 add_users_to_worklist(old);
560 hash_delete(old); // Yank from hash before hacking edges
561 subsume_node(old, nn);
562 }
563
564 // Delayed node rehash: remove a node from the hash table and rehash it during
565 // next optimizing pass
566 void rehash_node_delayed(Node* n) {
567 hash_delete(n);
568 _worklist.push(n);
569 }
570
571 // Replace ith edge of "n" with "in"
572 void replace_input_of(Node* n, uint i, Node* in) {
573 rehash_node_delayed(n);
574 n->set_req_X(i, in, this);
575 }
576
577 // Add "in" as input (req) of "n"
578 void add_input_to(Node* n, Node* in) {
579 rehash_node_delayed(n);
580 n->add_req(in);
581 }
582
583 // Delete ith edge of "n"
584 void delete_input_of(Node* n, uint i) {
585 rehash_node_delayed(n);
586 n->del_req(i);
587 }
588
589 // Delete precedence edge i of "n"
590 void delete_precedence_of(Node* n, uint i) {
591 rehash_node_delayed(n);
592 n->rm_prec(i);
593 }
594
595 bool delay_transform() const { return _delay_transform; }
596
597 void set_delay_transform(bool delay) {
598 _delay_transform = delay;
599 }
600
601 void remove_speculative_types();
602 void check_no_speculative_types() {
603 _table.check_no_speculative_types();
604 }
605
606 bool is_dominator(Node *d, Node *n) { return is_dominator_helper(d, n, false); }
607 bool no_dependent_zero_check(Node* n) const;
608
609 #ifndef PRODUCT
610 static bool is_verify_def_use() {
611 // '-XX:VerifyIterativeGVN=1'
612 return (VerifyIterativeGVN % 10) == 1;
613 }
614 static bool is_verify_Value() {
615 // '-XX:VerifyIterativeGVN=10'
616 return ((VerifyIterativeGVN % 100) / 10) == 1;
617 }
618 static bool is_verify_Ideal() {
619 // '-XX:VerifyIterativeGVN=100'
620 return ((VerifyIterativeGVN % 1000) / 100) == 1;
621 }
622 static bool is_verify_Identity() {
623 // '-XX:VerifyIterativeGVN=1000'
624 return ((VerifyIterativeGVN % 10000) / 1000) == 1;
625 }
626 static bool is_verify_invariants() {
627 // '-XX:VerifyIterativeGVN=10000'
628 return ((VerifyIterativeGVN % 100000) / 10000) == 1;
629 }
630 protected:
631 // Sub-quadratic implementation of '-XX:VerifyIterativeGVN=1' (Use-Def verification).
632 julong _verify_counter;
633 julong _verify_full_passes;
634 enum { _verify_window_size = 30 };
635 Node* _verify_window[_verify_window_size];
636 void verify_step(Node* n);
637 #endif
638 };
639
640 //------------------------------PhaseCCP---------------------------------------
641 // Phase for performing global Conditional Constant Propagation.
642 // Should be replaced with combined CCP & GVN someday.
643 class PhaseCCP : public PhaseIterGVN {
644 Unique_Node_List _root_and_safepoints;
645 Unique_Node_List _maybe_top_type_nodes;
646 // Non-recursive. Use analysis to transform single Node.
647 virtual Node* transform_once(Node* n);
648
649 Node* fetch_next_node(Unique_Node_List& worklist);
650 static void dump_type_and_node(const Node* n, const Type* t) PRODUCT_RETURN;
651
652 void push_child_nodes_to_worklist(Unique_Node_List& worklist, Node* n) const;
653 void push_if_not_bottom_type(Unique_Node_List& worklist, Node* n) const;
654 void push_more_uses(Unique_Node_List& worklist, Node* parent, const Node* use) const;
655 void push_phis(Unique_Node_List& worklist, const Node* use) const;
656 static void push_catch(Unique_Node_List& worklist, const Node* use);
657 void push_cmpu(Unique_Node_List& worklist, const Node* use) const;
658 static void push_counted_loop_phi(Unique_Node_List& worklist, Node* parent, const Node* use);
659 void push_loadp(Unique_Node_List& worklist, const Node* use) const;
660 void push_and(Unique_Node_List& worklist, const Node* parent, const Node* use) const;
661 void push_cast_ii(Unique_Node_List& worklist, const Node* parent, const Node* use) const;
662 void push_opaque_zero_trip_guard(Unique_Node_List& worklist, const Node* use) const;
663 void push_bool_with_cmpu_and_mask(Unique_Node_List& worklist, const Node* use) const;
664 void push_bool_matching_case1b(Unique_Node_List& worklist, const Node* cmpu) const;
665
666 public:
667 PhaseCCP( PhaseIterGVN *igvn ); // Compute conditional constants
668 NOT_PRODUCT( ~PhaseCCP(); )
669
670 // Worklist algorithm identifies constants
671 void analyze();
672 void analyze_step(Unique_Node_List& worklist, Node* n);
673 bool needs_revisit(Node* n) const;
674 #ifdef ASSERT
675 void verify_type(Node* n, const Type* tnew, const Type* told);
676 // For every node n on verify list, check if type(n) == n->Value()
677 void verify_analyze(Unique_Node_List& worklist_verify);
678 #endif
679 // Recursive traversal of program. Used analysis to modify program.
680 virtual Node *transform( Node *n );
681 // Do any transformation after analysis
682 void do_transform();
683
684 virtual const Type* saturate(const Type* new_type, const Type* old_type,
685 const Type* limit_type) const;
686 // Returns new_type->widen(old_type), which increments the widen bits until
687 // giving up with TypeInt::INT or TypeLong::LONG.
688 // Result is clipped to limit_type if necessary.
689 virtual const Type* saturate_and_maybe_push_to_igvn_worklist(const TypeNode* n, const Type* new_type) {
690 const Type* t = saturate(new_type, type_or_null(n), n->type());
691 if (t != new_type) {
692 // Type was widened in CCP, but IGVN may be able to make it narrower.
693 _worklist.push((Node*)n);
694 }
695 return t;
696 }
697
698 #ifndef PRODUCT
699 static uint _total_invokes; // For profiling, count invocations
700 void inc_invokes() { ++PhaseCCP::_total_invokes; }
701
702 static uint _total_constants; // For profiling, count constants found
703 uint _count_constants;
704 void clear_constants() { _count_constants = 0; }
705 void inc_constants() { ++_count_constants; }
706 uint count_constants() const { return _count_constants; }
707
708 static void print_statistics();
709 #endif
710 };
711
712
713 //------------------------------PhasePeephole----------------------------------
714 // Phase for performing peephole optimizations on register allocated basic blocks.
715 class PhasePeephole : public PhaseTransform {
716 PhaseRegAlloc *_regalloc;
717 PhaseCFG &_cfg;
718 // Recursive traversal of program. Pure function is unused in this phase
719 virtual Node *transform( Node *n );
720
721 public:
722 PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg );
723 NOT_PRODUCT( ~PhasePeephole(); )
724
725 // Do any transformation after analysis
726 void do_transform();
727
728 #ifndef PRODUCT
729 static uint _total_peepholes; // For profiling, count peephole rules applied
730 uint _count_peepholes;
731 void clear_peepholes() { _count_peepholes = 0; }
732 void inc_peepholes() { ++_count_peepholes; }
733 uint count_peepholes() const { return _count_peepholes; }
734
735 static void print_statistics();
736 #endif
737 };
738
739 #endif // SHARE_OPTO_PHASEX_HPP