1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "opto/block.hpp"
28 #include "opto/callnode.hpp"
29 #include "opto/cfgnode.hpp"
30 #include "opto/idealGraphPrinter.hpp"
31 #include "opto/loopnode.hpp"
32 #include "opto/machnode.hpp"
33 #include "opto/opcodes.hpp"
34 #include "opto/phaseX.hpp"
35 #include "opto/regalloc.hpp"
36 #include "opto/rootnode.hpp"
37
38 //=============================================================================
39 #define NODE_HASH_MINIMUM_SIZE 255
40 //------------------------------NodeHash---------------------------------------
41 NodeHash::NodeHash(uint est_max_size) :
42 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
43 _a(Thread::current()->resource_area()),
44 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ),
45 _inserts(0), _insert_limit( insert_limit() )
46 #ifndef PRODUCT
47 ,_look_probes(0), _lookup_hits(0), _lookup_misses(0),
48 _delete_probes(0), _delete_hits(0), _delete_misses(0),
49 _total_insert_probes(0), _total_inserts(0),
50 _insert_probes(0), _grows(0)
51 #endif
52 {
53 // _sentinel must be in the current node space
54 _sentinel = new ProjNode(NULL, TypeFunc::Control);
55 memset(_table,0,sizeof(Node*)*_max);
56 }
57
58 //------------------------------NodeHash---------------------------------------
59 NodeHash::NodeHash(Arena *arena, uint est_max_size) :
60 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
61 _a(arena),
62 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ),
63 _inserts(0), _insert_limit( insert_limit() )
64 #ifndef PRODUCT
65 ,_look_probes(0), _lookup_hits(0), _lookup_misses(0),
66 _delete_probes(0), _delete_hits(0), _delete_misses(0),
67 _total_insert_probes(0), _total_inserts(0),
68 _insert_probes(0), _grows(0)
69 #endif
70 {
71 // _sentinel must be in the current node space
72 _sentinel = new ProjNode(NULL, TypeFunc::Control);
73 memset(_table,0,sizeof(Node*)*_max);
74 }
75
76 //------------------------------NodeHash---------------------------------------
77 NodeHash::NodeHash(NodeHash *nh) {
78 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator=
79 // just copy in all the fields
80 *this = *nh;
81 // nh->_sentinel must be in the current node space
82 }
83
84 void NodeHash::replace_with(NodeHash *nh) {
85 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator=
86 // just copy in all the fields
87 *this = *nh;
88 // nh->_sentinel must be in the current node space
89 }
90
91 //------------------------------hash_find--------------------------------------
92 // Find in hash table
93 Node *NodeHash::hash_find( const Node *n ) {
94 // ((Node*)n)->set_hash( n->hash() );
95 uint hash = n->hash();
96 if (hash == Node::NO_HASH) {
97 NOT_PRODUCT( _lookup_misses++ );
98 return NULL;
99 }
100 uint key = hash & (_max-1);
101 uint stride = key | 0x01;
102 NOT_PRODUCT( _look_probes++ );
103 Node *k = _table[key]; // Get hashed value
104 if( !k ) { // ?Miss?
105 NOT_PRODUCT( _lookup_misses++ );
106 return NULL; // Miss!
107 }
108
109 int op = n->Opcode();
110 uint req = n->req();
111 while( 1 ) { // While probing hash table
112 if( k->req() == req && // Same count of inputs
113 k->Opcode() == op ) { // Same Opcode
114 for( uint i=0; i<req; i++ )
115 if( n->in(i)!=k->in(i)) // Different inputs?
116 goto collision; // "goto" is a speed hack...
117 if( n->cmp(*k) ) { // Check for any special bits
118 NOT_PRODUCT( _lookup_hits++ );
119 return k; // Hit!
120 }
121 }
122 collision:
123 NOT_PRODUCT( _look_probes++ );
124 key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime
125 k = _table[key]; // Get hashed value
126 if( !k ) { // ?Miss?
127 NOT_PRODUCT( _lookup_misses++ );
128 return NULL; // Miss!
129 }
130 }
131 ShouldNotReachHere();
132 return NULL;
133 }
134
135 //------------------------------hash_find_insert-------------------------------
136 // Find in hash table, insert if not already present
137 // Used to preserve unique entries in hash table
138 Node *NodeHash::hash_find_insert( Node *n ) {
139 // n->set_hash( );
140 uint hash = n->hash();
141 if (hash == Node::NO_HASH) {
142 NOT_PRODUCT( _lookup_misses++ );
143 return NULL;
144 }
145 uint key = hash & (_max-1);
146 uint stride = key | 0x01; // stride must be relatively prime to table siz
147 uint first_sentinel = 0; // replace a sentinel if seen.
148 NOT_PRODUCT( _look_probes++ );
149 Node *k = _table[key]; // Get hashed value
150 if( !k ) { // ?Miss?
151 NOT_PRODUCT( _lookup_misses++ );
152 _table[key] = n; // Insert into table!
153 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
154 check_grow(); // Grow table if insert hit limit
155 return NULL; // Miss!
156 }
157 else if( k == _sentinel ) {
158 first_sentinel = key; // Can insert here
159 }
160
161 int op = n->Opcode();
162 uint req = n->req();
163 while( 1 ) { // While probing hash table
164 if( k->req() == req && // Same count of inputs
165 k->Opcode() == op ) { // Same Opcode
166 for( uint i=0; i<req; i++ )
167 if( n->in(i)!=k->in(i)) // Different inputs?
168 goto collision; // "goto" is a speed hack...
169 if( n->cmp(*k) ) { // Check for any special bits
170 NOT_PRODUCT( _lookup_hits++ );
171 return k; // Hit!
172 }
173 }
174 collision:
175 NOT_PRODUCT( _look_probes++ );
176 key = (key + stride) & (_max-1); // Stride through table w/ relative prime
177 k = _table[key]; // Get hashed value
178 if( !k ) { // ?Miss?
179 NOT_PRODUCT( _lookup_misses++ );
180 key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel?
181 _table[key] = n; // Insert into table!
182 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
183 check_grow(); // Grow table if insert hit limit
184 return NULL; // Miss!
185 }
186 else if( first_sentinel == 0 && k == _sentinel ) {
187 first_sentinel = key; // Can insert here
188 }
189
190 }
191 ShouldNotReachHere();
192 return NULL;
193 }
194
195 //------------------------------hash_insert------------------------------------
196 // Insert into hash table
197 void NodeHash::hash_insert( Node *n ) {
198 // // "conflict" comments -- print nodes that conflict
199 // bool conflict = false;
200 // n->set_hash();
201 uint hash = n->hash();
202 if (hash == Node::NO_HASH) {
203 return;
204 }
205 check_grow();
206 uint key = hash & (_max-1);
207 uint stride = key | 0x01;
208
209 while( 1 ) { // While probing hash table
210 NOT_PRODUCT( _insert_probes++ );
211 Node *k = _table[key]; // Get hashed value
212 if( !k || (k == _sentinel) ) break; // Found a slot
213 assert( k != n, "already inserted" );
214 // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; }
215 key = (key + stride) & (_max-1); // Stride through table w/ relative prime
216 }
217 _table[key] = n; // Insert into table!
218 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
219 // if( conflict ) { n->dump(); }
220 }
221
222 //------------------------------hash_delete------------------------------------
223 // Replace in hash table with sentinel
224 bool NodeHash::hash_delete( const Node *n ) {
225 Node *k;
226 uint hash = n->hash();
227 if (hash == Node::NO_HASH) {
228 NOT_PRODUCT( _delete_misses++ );
229 return false;
230 }
231 uint key = hash & (_max-1);
232 uint stride = key | 0x01;
233 debug_only( uint counter = 0; );
234 for( ; /* (k != NULL) && (k != _sentinel) */; ) {
235 debug_only( counter++ );
236 NOT_PRODUCT( _delete_probes++ );
237 k = _table[key]; // Get hashed value
238 if( !k ) { // Miss?
239 NOT_PRODUCT( _delete_misses++ );
240 #ifdef ASSERT
241 if( VerifyOpto ) {
242 for( uint i=0; i < _max; i++ )
243 assert( _table[i] != n, "changed edges with rehashing" );
244 }
245 #endif
246 return false; // Miss! Not in chain
247 }
248 else if( n == k ) {
249 NOT_PRODUCT( _delete_hits++ );
250 _table[key] = _sentinel; // Hit! Label as deleted entry
251 debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table.
252 return true;
253 }
254 else {
255 // collision: move through table with prime offset
256 key = (key + stride/*7*/) & (_max-1);
257 assert( counter <= _insert_limit, "Cycle in hash-table");
258 }
259 }
260 ShouldNotReachHere();
261 return false;
262 }
263
264 //------------------------------round_up---------------------------------------
265 // Round up to nearest power of 2
266 uint NodeHash::round_up( uint x ) {
267 x += (x>>2); // Add 25% slop
268 if( x <16 ) return 16; // Small stuff
269 uint i=16;
270 while( i < x ) i <<= 1; // Double to fit
271 return i; // Return hash table size
272 }
273
274 //------------------------------grow-------------------------------------------
275 // Grow _table to next power of 2 and insert old entries
276 void NodeHash::grow() {
277 // Record old state
278 uint old_max = _max;
279 Node **old_table = _table;
280 // Construct new table with twice the space
281 #ifndef PRODUCT
282 _grows++;
283 _total_inserts += _inserts;
284 _total_insert_probes += _insert_probes;
285 _insert_probes = 0;
286 #endif
287 _inserts = 0;
288 _max = _max << 1;
289 _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) );
290 memset(_table,0,sizeof(Node*)*_max);
291 _insert_limit = insert_limit();
292 // Insert old entries into the new table
293 for( uint i = 0; i < old_max; i++ ) {
294 Node *m = *old_table++;
295 if( !m || m == _sentinel ) continue;
296 debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table.
297 hash_insert(m);
298 }
299 }
300
301 //------------------------------clear------------------------------------------
302 // Clear all entries in _table to NULL but keep storage
303 void NodeHash::clear() {
304 #ifdef ASSERT
305 // Unlock all nodes upon removal from table.
306 for (uint i = 0; i < _max; i++) {
307 Node* n = _table[i];
308 if (!n || n == _sentinel) continue;
309 n->exit_hash_lock();
310 }
311 #endif
312
313 memset( _table, 0, _max * sizeof(Node*) );
314 }
315
316 //-----------------------remove_useless_nodes----------------------------------
317 // Remove useless nodes from value table,
318 // implementation does not depend on hash function
319 void NodeHash::remove_useless_nodes(VectorSet &useful) {
320
321 // Dead nodes in the hash table inherited from GVN should not replace
322 // existing nodes, remove dead nodes.
323 uint max = size();
324 Node *sentinel_node = sentinel();
325 for( uint i = 0; i < max; ++i ) {
326 Node *n = at(i);
327 if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) {
328 debug_only(n->exit_hash_lock()); // Unlock the node when removed
329 _table[i] = sentinel_node; // Replace with placeholder
330 }
331 }
332 }
333
334
335 void NodeHash::check_no_speculative_types() {
336 #ifdef ASSERT
337 uint max = size();
338 Node *sentinel_node = sentinel();
339 for (uint i = 0; i < max; ++i) {
340 Node *n = at(i);
341 if(n != NULL && n != sentinel_node && n->is_Type() && n->outcnt() > 0) {
342 TypeNode* tn = n->as_Type();
343 const Type* t = tn->type();
344 const Type* t_no_spec = t->remove_speculative();
345 assert(t == t_no_spec, "dead node in hash table or missed node during speculative cleanup");
346 }
347 }
348 #endif
349 }
350
351 #ifndef PRODUCT
352 //------------------------------dump-------------------------------------------
353 // Dump statistics for the hash table
354 void NodeHash::dump() {
355 _total_inserts += _inserts;
356 _total_insert_probes += _insert_probes;
357 if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) {
358 if (WizardMode) {
359 for (uint i=0; i<_max; i++) {
360 if (_table[i])
361 tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx);
362 }
363 }
364 tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max);
365 tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0);
366 tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses));
367 tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts);
368 // sentinels increase lookup cost, but not insert cost
369 assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function");
370 assert( _inserts+(_inserts>>3) < _max, "table too full" );
371 assert( _inserts*3+100 >= _insert_probes, "bad hash function" );
372 }
373 }
374
375 Node *NodeHash::find_index(uint idx) { // For debugging
376 // Find an entry by its index value
377 for( uint i = 0; i < _max; i++ ) {
378 Node *m = _table[i];
379 if( !m || m == _sentinel ) continue;
380 if( m->_idx == (uint)idx ) return m;
381 }
382 return NULL;
383 }
384 #endif
385
386 #ifdef ASSERT
387 NodeHash::~NodeHash() {
388 // Unlock all nodes upon destruction of table.
389 if (_table != (Node**)badAddress) clear();
390 }
391
392 void NodeHash::operator=(const NodeHash& nh) {
393 // Unlock all nodes upon replacement of table.
394 if (&nh == this) return;
395 if (_table != (Node**)badAddress) clear();
396 memcpy(this, &nh, sizeof(*this));
397 // Do not increment hash_lock counts again.
398 // Instead, be sure we never again use the source table.
399 ((NodeHash*)&nh)->_table = (Node**)badAddress;
400 }
401
402
403 #endif
404
405
406 //=============================================================================
407 //------------------------------PhaseRemoveUseless-----------------------------
408 // 1) Use a breadthfirst walk to collect useful nodes reachable from root.
409 PhaseRemoveUseless::PhaseRemoveUseless(PhaseGVN *gvn, Unique_Node_List *worklist, PhaseNumber phase_num) : Phase(phase_num),
410 _useful(Thread::current()->resource_area()) {
411
412 // Implementation requires 'UseLoopSafepoints == true' and an edge from root
413 // to each SafePointNode at a backward branch. Inserted in add_safepoint().
414 if( !UseLoopSafepoints || !OptoRemoveUseless ) return;
415
416 // Identify nodes that are reachable from below, useful.
417 C->identify_useful_nodes(_useful);
418 // Update dead node list
419 C->update_dead_node_list(_useful);
420
421 // Remove all useless nodes from PhaseValues' recorded types
422 // Must be done before disconnecting nodes to preserve hash-table-invariant
423 gvn->remove_useless_nodes(_useful.member_set());
424
425 // Remove all useless nodes from future worklist
426 worklist->remove_useless_nodes(_useful.member_set());
427
428 // Disconnect 'useless' nodes that are adjacent to useful nodes
429 C->remove_useless_nodes(_useful);
430
431 // Remove edges from "root" to each SafePoint at a backward branch.
432 // They were inserted during parsing (see add_safepoint()) to make infinite
433 // loops without calls or exceptions visible to root, i.e., useful.
434 Node *root = C->root();
435 if( root != NULL ) {
436 for( uint i = root->req(); i < root->len(); ++i ) {
437 Node *n = root->in(i);
438 if( n != NULL && n->is_SafePoint() ) {
439 root->rm_prec(i);
440 --i;
441 }
442 }
443 }
444 }
445
446 //=============================================================================
447 //------------------------------PhaseRenumberLive------------------------------
448 // First, remove useless nodes (equivalent to identifying live nodes).
449 // Then, renumber live nodes.
450 //
451 // The set of live nodes is returned by PhaseRemoveUseless in the _useful structure.
452 // If the number of live nodes is 'x' (where 'x' == _useful.size()), then the
453 // PhaseRenumberLive updates the node ID of each node (the _idx field) with a unique
454 // value in the range [0, x).
455 //
456 // At the end of the PhaseRenumberLive phase, the compiler's count of unique nodes is
457 // updated to 'x' and the list of dead nodes is reset (as there are no dead nodes).
458 //
459 // The PhaseRenumberLive phase updates two data structures with the new node IDs.
460 // (1) The worklist is used by the PhaseIterGVN phase to identify nodes that must be
461 // processed. A new worklist (with the updated node IDs) is returned in 'new_worklist'.
462 // (2) Type information (the field PhaseGVN::_types) maps type information to each
463 // node ID. The mapping is updated to use the new node IDs as well. Updated type
464 // information is returned in PhaseGVN::_types.
465 //
466 // The PhaseRenumberLive phase does not preserve the order of elements in the worklist.
467 //
468 // Other data structures used by the compiler are not updated. The hash table for value
469 // numbering (the field PhaseGVN::_table) is not updated because computing the hash
470 // values is not based on node IDs. The field PhaseGVN::_nodes is not updated either
471 // because it is empty wherever PhaseRenumberLive is used.
472 PhaseRenumberLive::PhaseRenumberLive(PhaseGVN* gvn,
473 Unique_Node_List* worklist, Unique_Node_List* new_worklist,
474 PhaseNumber phase_num) :
475 PhaseRemoveUseless(gvn, worklist, Remove_Useless_And_Renumber_Live) {
476
477 assert(RenumberLiveNodes, "RenumberLiveNodes must be set to true for node renumbering to take place");
478 assert(C->live_nodes() == _useful.size(), "the number of live nodes must match the number of useful nodes");
479 assert(gvn->nodes_size() == 0, "GVN must not contain any nodes at this point");
480
481 uint old_unique_count = C->unique();
482 uint live_node_count = C->live_nodes();
483 uint worklist_size = worklist->size();
484
485 // Storage for the updated type information.
486 Type_Array new_type_array(C->comp_arena());
487
488 // Iterate over the set of live nodes.
489 uint current_idx = 0; // The current new node ID. Incremented after every assignment.
490 for (uint i = 0; i < _useful.size(); i++) {
491 Node* n = _useful.at(i);
492 const Type* type = gvn->type_or_null(n);
493 new_type_array.map(current_idx, type);
494
495 bool in_worklist = false;
496 if (worklist->member(n)) {
497 in_worklist = true;
498 }
499
500 n->set_idx(current_idx); // Update node ID.
501
502 if (in_worklist) {
503 new_worklist->push(n);
504 }
505
506 current_idx++;
507 }
508
509 assert(worklist_size == new_worklist->size(), "the new worklist must have the same size as the original worklist");
510 assert(live_node_count == current_idx, "all live nodes must be processed");
511
512 // Replace the compiler's type information with the updated type information.
513 gvn->replace_types(new_type_array);
514
515 // Update the unique node count of the compilation to the number of currently live nodes.
516 C->set_unique(live_node_count);
517
518 // Set the dead node count to 0 and reset dead node list.
519 C->reset_dead_node_list();
520 }
521
522
523 //=============================================================================
524 //------------------------------PhaseTransform---------------------------------
525 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum),
526 _arena(Thread::current()->resource_area()),
527 _nodes(_arena),
528 _types(_arena)
529 {
530 init_con_caches();
531 #ifndef PRODUCT
532 clear_progress();
533 clear_transforms();
534 set_allow_progress(true);
535 #endif
536 // Force allocation for currently existing nodes
537 _types.map(C->unique(), NULL);
538 }
539
540 //------------------------------PhaseTransform---------------------------------
541 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum),
542 _arena(arena),
543 _nodes(arena),
544 _types(arena)
545 {
546 init_con_caches();
547 #ifndef PRODUCT
548 clear_progress();
549 clear_transforms();
550 set_allow_progress(true);
551 #endif
552 // Force allocation for currently existing nodes
553 _types.map(C->unique(), NULL);
554 }
555
556 //------------------------------PhaseTransform---------------------------------
557 // Initialize with previously generated type information
558 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum),
559 _arena(pt->_arena),
560 _nodes(pt->_nodes),
561 _types(pt->_types)
562 {
563 init_con_caches();
564 #ifndef PRODUCT
565 clear_progress();
566 clear_transforms();
567 set_allow_progress(true);
568 #endif
569 }
570
571 void PhaseTransform::init_con_caches() {
572 memset(_icons,0,sizeof(_icons));
573 memset(_lcons,0,sizeof(_lcons));
574 memset(_zcons,0,sizeof(_zcons));
575 }
576
577
578 //--------------------------------find_int_type--------------------------------
579 const TypeInt* PhaseTransform::find_int_type(Node* n) {
580 if (n == NULL) return NULL;
581 // Call type_or_null(n) to determine node's type since we might be in
582 // parse phase and call n->Value() may return wrong type.
583 // (For example, a phi node at the beginning of loop parsing is not ready.)
584 const Type* t = type_or_null(n);
585 if (t == NULL) return NULL;
586 return t->isa_int();
587 }
588
589
590 //-------------------------------find_long_type--------------------------------
591 const TypeLong* PhaseTransform::find_long_type(Node* n) {
592 if (n == NULL) return NULL;
593 // (See comment above on type_or_null.)
594 const Type* t = type_or_null(n);
595 if (t == NULL) return NULL;
596 return t->isa_long();
597 }
598
599
600 #ifndef PRODUCT
601 void PhaseTransform::dump_old2new_map() const {
602 _nodes.dump();
603 }
604
605 void PhaseTransform::dump_new( uint nidx ) const {
606 for( uint i=0; i<_nodes.Size(); i++ )
607 if( _nodes[i] && _nodes[i]->_idx == nidx ) {
608 _nodes[i]->dump();
609 tty->cr();
610 tty->print_cr("Old index= %d",i);
611 return;
612 }
613 tty->print_cr("Node %d not found in the new indices", nidx);
614 }
615
616 //------------------------------dump_types-------------------------------------
617 void PhaseTransform::dump_types( ) const {
618 _types.dump();
619 }
620
621 //------------------------------dump_nodes_and_types---------------------------
622 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) {
623 VectorSet visited(Thread::current()->resource_area());
624 dump_nodes_and_types_recur( root, depth, only_ctrl, visited );
625 }
626
627 //------------------------------dump_nodes_and_types_recur---------------------
628 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) {
629 if( !n ) return;
630 if( depth == 0 ) return;
631 if( visited.test_set(n->_idx) ) return;
632 for( uint i=0; i<n->len(); i++ ) {
633 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue;
634 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited );
635 }
636 n->dump();
637 if (type_or_null(n) != NULL) {
638 tty->print(" "); type(n)->dump(); tty->cr();
639 }
640 }
641
642 #endif
643
644
645 //=============================================================================
646 //------------------------------PhaseValues------------------------------------
647 // Set minimum table size to "255"
648 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) {
649 NOT_PRODUCT( clear_new_values(); )
650 }
651
652 //------------------------------PhaseValues------------------------------------
653 // Set minimum table size to "255"
654 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ),
655 _table(&ptv->_table) {
656 NOT_PRODUCT( clear_new_values(); )
657 }
658
659 //------------------------------PhaseValues------------------------------------
660 // Used by +VerifyOpto. Clear out hash table but copy _types array.
661 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ),
662 _table(ptv->arena(),ptv->_table.size()) {
663 NOT_PRODUCT( clear_new_values(); )
664 }
665
666 //------------------------------~PhaseValues-----------------------------------
667 #ifndef PRODUCT
668 PhaseValues::~PhaseValues() {
669 _table.dump();
670
671 // Statistics for value progress and efficiency
672 if( PrintCompilation && Verbose && WizardMode ) {
673 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)",
674 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values());
675 if( made_transforms() != 0 ) {
676 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() );
677 } else {
678 tty->cr();
679 }
680 }
681 }
682 #endif
683
684 //------------------------------makecon----------------------------------------
685 ConNode* PhaseTransform::makecon(const Type *t) {
686 assert(t->singleton(), "must be a constant");
687 assert(!t->empty() || t == Type::TOP, "must not be vacuous range");
688 switch (t->base()) { // fast paths
689 case Type::Half:
690 case Type::Top: return (ConNode*) C->top();
691 case Type::Int: return intcon( t->is_int()->get_con() );
692 case Type::Long: return longcon( t->is_long()->get_con() );
693 }
694 if (t->is_zero_type())
695 return zerocon(t->basic_type());
696 return uncached_makecon(t);
697 }
698
699 //--------------------------uncached_makecon-----------------------------------
700 // Make an idealized constant - one of ConINode, ConPNode, etc.
701 ConNode* PhaseValues::uncached_makecon(const Type *t) {
702 assert(t->singleton(), "must be a constant");
703 ConNode* x = ConNode::make(t);
704 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering
705 if (k == NULL) {
706 set_type(x, t); // Missed, provide type mapping
707 GrowableArray<Node_Notes*>* nna = C->node_note_array();
708 if (nna != NULL) {
709 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true);
710 loc->clear(); // do not put debug info on constants
711 }
712 } else {
713 x->destruct(); // Hit, destroy duplicate constant
714 x = k; // use existing constant
715 }
716 return x;
717 }
718
719 //------------------------------intcon-----------------------------------------
720 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))"
721 ConINode* PhaseTransform::intcon(int i) {
722 // Small integer? Check cache! Check that cached node is not dead
723 if (i >= _icon_min && i <= _icon_max) {
724 ConINode* icon = _icons[i-_icon_min];
725 if (icon != NULL && icon->in(TypeFunc::Control) != NULL)
726 return icon;
727 }
728 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i));
729 assert(icon->is_Con(), "");
730 if (i >= _icon_min && i <= _icon_max)
731 _icons[i-_icon_min] = icon; // Cache small integers
732 return icon;
733 }
734
735 //------------------------------longcon----------------------------------------
736 // Fast long constant.
737 ConLNode* PhaseTransform::longcon(jlong l) {
738 // Small integer? Check cache! Check that cached node is not dead
739 if (l >= _lcon_min && l <= _lcon_max) {
740 ConLNode* lcon = _lcons[l-_lcon_min];
741 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL)
742 return lcon;
743 }
744 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l));
745 assert(lcon->is_Con(), "");
746 if (l >= _lcon_min && l <= _lcon_max)
747 _lcons[l-_lcon_min] = lcon; // Cache small integers
748 return lcon;
749 }
750
751 //------------------------------zerocon-----------------------------------------
752 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))"
753 ConNode* PhaseTransform::zerocon(BasicType bt) {
754 assert((uint)bt <= _zcon_max, "domain check");
755 ConNode* zcon = _zcons[bt];
756 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL)
757 return zcon;
758 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt));
759 _zcons[bt] = zcon;
760 return zcon;
761 }
762
763
764
765 //=============================================================================
766 //------------------------------transform--------------------------------------
767 // Return a node which computes the same function as this node, but in a
768 // faster or cheaper fashion.
769 Node *PhaseGVN::transform( Node *n ) {
770 return transform_no_reclaim(n);
771 }
772
773 //------------------------------transform--------------------------------------
774 // Return a node which computes the same function as this node, but
775 // in a faster or cheaper fashion.
776 Node *PhaseGVN::transform_no_reclaim( Node *n ) {
777 NOT_PRODUCT( set_transforms(); )
778
779 // Apply the Ideal call in a loop until it no longer applies
780 Node *k = n;
781 NOT_PRODUCT( uint loop_count = 0; )
782 while( 1 ) {
783 Node *i = k->Ideal(this, /*can_reshape=*/false);
784 if( !i ) break;
785 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" );
786 k = i;
787 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform");
788 }
789 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } )
790
791
792 // If brand new node, make space in type array.
793 ensure_type_or_null(k);
794
795 // Since I just called 'Value' to compute the set of run-time values
796 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
797 // cache Value. Later requests for the local phase->type of this Node can
798 // use the cached Value instead of suffering with 'bottom_type'.
799 const Type *t = k->Value(this); // Get runtime Value set
800 assert(t != NULL, "value sanity");
801 if (type_or_null(k) != t) {
802 #ifndef PRODUCT
803 // Do not count initial visit to node as a transformation
804 if (type_or_null(k) == NULL) {
805 inc_new_values();
806 set_progress();
807 }
808 #endif
809 set_type(k, t);
810 // If k is a TypeNode, capture any more-precise type permanently into Node
811 k->raise_bottom_type(t);
812 }
813
814 if( t->singleton() && !k->is_Con() ) {
815 NOT_PRODUCT( set_progress(); )
816 return makecon(t); // Turn into a constant
817 }
818
819 // Now check for Identities
820 Node *i = k->Identity(this); // Look for a nearby replacement
821 if( i != k ) { // Found? Return replacement!
822 NOT_PRODUCT( set_progress(); )
823 return i;
824 }
825
826 // Global Value Numbering
827 i = hash_find_insert(k); // Insert if new
828 if( i && (i != k) ) {
829 // Return the pre-existing node
830 NOT_PRODUCT( set_progress(); )
831 return i;
832 }
833
834 // Return Idealized original
835 return k;
836 }
837
838 #ifdef ASSERT
839 //------------------------------dead_loop_check--------------------------------
840 // Check for a simple dead loop when a data node references itself directly
841 // or through an other data node excluding cons and phis.
842 void PhaseGVN::dead_loop_check( Node *n ) {
843 // Phi may reference itself in a loop
844 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) {
845 // Do 2 levels check and only data inputs.
846 bool no_dead_loop = true;
847 uint cnt = n->req();
848 for (uint i = 1; i < cnt && no_dead_loop; i++) {
849 Node *in = n->in(i);
850 if (in == n) {
851 no_dead_loop = false;
852 } else if (in != NULL && !in->is_dead_loop_safe()) {
853 uint icnt = in->req();
854 for (uint j = 1; j < icnt && no_dead_loop; j++) {
855 if (in->in(j) == n || in->in(j) == in)
856 no_dead_loop = false;
857 }
858 }
859 }
860 if (!no_dead_loop) n->dump(3);
861 assert(no_dead_loop, "dead loop detected");
862 }
863 }
864 #endif
865
866 //=============================================================================
867 //------------------------------PhaseIterGVN-----------------------------------
868 // Initialize hash table to fresh and clean for +VerifyOpto
869 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ),
870 _stack(C->live_nodes() >> 1),
871 _delay_transform(false) {
872 }
873
874 //------------------------------PhaseIterGVN-----------------------------------
875 // Initialize with previous PhaseIterGVN info; used by PhaseCCP
876 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn),
877 _worklist( igvn->_worklist ),
878 _stack( igvn->_stack ),
879 _delay_transform(igvn->_delay_transform)
880 {
881 }
882
883 //------------------------------PhaseIterGVN-----------------------------------
884 // Initialize with previous PhaseGVN info from Parser
885 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn),
886 _worklist(*C->for_igvn()),
887 // TODO: Before incremental inlining it was allocated only once and it was fine. Now that
888 // the constructor is used in incremental inlining, this consumes too much memory:
889 // _stack(C->live_nodes() >> 1),
890 // So, as a band-aid, we replace this by:
891 _stack(C->comp_arena(), 32),
892 _delay_transform(false)
893 {
894 uint max;
895
896 // Dead nodes in the hash table inherited from GVN were not treated as
897 // roots during def-use info creation; hence they represent an invisible
898 // use. Clear them out.
899 max = _table.size();
900 for( uint i = 0; i < max; ++i ) {
901 Node *n = _table.at(i);
902 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) {
903 if( n->is_top() ) continue;
904 assert( false, "Parse::remove_useless_nodes missed this node");
905 hash_delete(n);
906 }
907 }
908
909 // Any Phis or Regions on the worklist probably had uses that could not
910 // make more progress because the uses were made while the Phis and Regions
911 // were in half-built states. Put all uses of Phis and Regions on worklist.
912 max = _worklist.size();
913 for( uint j = 0; j < max; j++ ) {
914 Node *n = _worklist.at(j);
915 uint uop = n->Opcode();
916 if( uop == Op_Phi || uop == Op_Region ||
917 n->is_Type() ||
918 n->is_Mem() )
919 add_users_to_worklist(n);
920 }
921 }
922
923 /**
924 * Initialize worklist for each node.
925 */
926 void PhaseIterGVN::init_worklist(Node* first) {
927 Unique_Node_List to_process;
928 to_process.push(first);
929
930 while (to_process.size() > 0) {
931 Node* n = to_process.pop();
932 if (!_worklist.member(n)) {
933 _worklist.push(n);
934
935 uint cnt = n->req();
936 for(uint i = 0; i < cnt; i++) {
937 Node* m = n->in(i);
938 if (m != NULL) {
939 to_process.push(m);
940 }
941 }
942 }
943 }
944 }
945
946 #ifndef PRODUCT
947 void PhaseIterGVN::verify_step(Node* n) {
948 if (VerifyIterativeGVN) {
949 _verify_window[_verify_counter % _verify_window_size] = n;
950 ++_verify_counter;
951 ResourceMark rm;
952 ResourceArea* area = Thread::current()->resource_area();
953 VectorSet old_space(area), new_space(area);
954 if (C->unique() < 1000 ||
955 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) {
956 ++_verify_full_passes;
957 Node::verify_recur(C->root(), -1, old_space, new_space);
958 }
959 const int verify_depth = 4;
960 for ( int i = 0; i < _verify_window_size; i++ ) {
961 Node* n = _verify_window[i];
962 if ( n == NULL ) continue;
963 if( n->in(0) == NodeSentinel ) { // xform_idom
964 _verify_window[i] = n->in(1);
965 --i; continue;
966 }
967 // Typical fanout is 1-2, so this call visits about 6 nodes.
968 Node::verify_recur(n, verify_depth, old_space, new_space);
969 }
970 }
971 }
972
973 void PhaseIterGVN::trace_PhaseIterGVN(Node* n, Node* nn, const Type* oldtype) {
974 if (TraceIterativeGVN) {
975 uint wlsize = _worklist.size();
976 const Type* newtype = type_or_null(n);
977 if (nn != n) {
978 // print old node
979 tty->print("< ");
980 if (oldtype != newtype && oldtype != NULL) {
981 oldtype->dump();
982 }
983 do { tty->print("\t"); } while (tty->position() < 16);
984 tty->print("<");
985 n->dump();
986 }
987 if (oldtype != newtype || nn != n) {
988 // print new node and/or new type
989 if (oldtype == NULL) {
990 tty->print("* ");
991 } else if (nn != n) {
992 tty->print("> ");
993 } else {
994 tty->print("= ");
995 }
996 if (newtype == NULL) {
997 tty->print("null");
998 } else {
999 newtype->dump();
1000 }
1001 do { tty->print("\t"); } while (tty->position() < 16);
1002 nn->dump();
1003 }
1004 if (Verbose && wlsize < _worklist.size()) {
1005 tty->print(" Push {");
1006 while (wlsize != _worklist.size()) {
1007 Node* pushed = _worklist.at(wlsize++);
1008 tty->print(" %d", pushed->_idx);
1009 }
1010 tty->print_cr(" }");
1011 }
1012 if (nn != n) {
1013 // ignore n, it might be subsumed
1014 verify_step((Node*) NULL);
1015 }
1016 }
1017 }
1018
1019 void PhaseIterGVN::init_verifyPhaseIterGVN() {
1020 _verify_counter = 0;
1021 _verify_full_passes = 0;
1022 for (int i = 0; i < _verify_window_size; i++) {
1023 _verify_window[i] = NULL;
1024 }
1025 #ifdef ASSERT
1026 // Verify that all modified nodes are on _worklist
1027 Unique_Node_List* modified_list = C->modified_nodes();
1028 while (modified_list != NULL && modified_list->size()) {
1029 Node* n = modified_list->pop();
1030 if (n->outcnt() != 0 && !n->is_Con() && !_worklist.member(n)) {
1031 n->dump();
1032 assert(false, "modified node is not on IGVN._worklist");
1033 }
1034 }
1035 #endif
1036 }
1037
1038 void PhaseIterGVN::verify_PhaseIterGVN() {
1039 #ifdef ASSERT
1040 // Verify nodes with changed inputs.
1041 Unique_Node_List* modified_list = C->modified_nodes();
1042 while (modified_list != NULL && modified_list->size()) {
1043 Node* n = modified_list->pop();
1044 if (n->outcnt() != 0 && !n->is_Con()) { // skip dead and Con nodes
1045 n->dump();
1046 assert(false, "modified node was not processed by IGVN.transform_old()");
1047 }
1048 }
1049 #endif
1050
1051 C->verify_graph_edges();
1052 if( VerifyOpto && allow_progress() ) {
1053 // Must turn off allow_progress to enable assert and break recursion
1054 C->root()->verify();
1055 { // Check if any progress was missed using IterGVN
1056 // Def-Use info enables transformations not attempted in wash-pass
1057 // e.g. Region/Phi cleanup, ...
1058 // Null-check elision -- may not have reached fixpoint
1059 // do not propagate to dominated nodes
1060 ResourceMark rm;
1061 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean!
1062 // Fill worklist completely
1063 igvn2.init_worklist(C->root());
1064
1065 igvn2.set_allow_progress(false);
1066 igvn2.optimize();
1067 igvn2.set_allow_progress(true);
1068 }
1069 }
1070 if (VerifyIterativeGVN && PrintOpto) {
1071 if (_verify_counter == _verify_full_passes) {
1072 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes",
1073 (int) _verify_full_passes);
1074 } else {
1075 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes",
1076 (int) _verify_counter, (int) _verify_full_passes);
1077 }
1078 }
1079
1080 #ifdef ASSERT
1081 while (modified_list->size()) {
1082 Node* n = modified_list->pop();
1083 n->dump();
1084 assert(false, "VerifyIterativeGVN: new modified node was added");
1085 }
1086 #endif
1087 }
1088 #endif /* PRODUCT */
1089
1090 #ifdef ASSERT
1091 /**
1092 * Dumps information that can help to debug the problem. A debug
1093 * build fails with an assert.
1094 */
1095 void PhaseIterGVN::dump_infinite_loop_info(Node* n) {
1096 n->dump(4);
1097 _worklist.dump();
1098 assert(false, "infinite loop in PhaseIterGVN::optimize");
1099 }
1100
1101 /**
1102 * Prints out information about IGVN if the 'verbose' option is used.
1103 */
1104 void PhaseIterGVN::trace_PhaseIterGVN_verbose(Node* n, int num_processed) {
1105 if (TraceIterativeGVN && Verbose) {
1106 tty->print(" Pop ");
1107 n->dump();
1108 if ((num_processed % 100) == 0) {
1109 _worklist.print_set();
1110 }
1111 }
1112 }
1113 #endif /* ASSERT */
1114
1115 void PhaseIterGVN::optimize() {
1116 DEBUG_ONLY(uint num_processed = 0;)
1117 NOT_PRODUCT(init_verifyPhaseIterGVN();)
1118
1119 uint loop_count = 0;
1120 // Pull from worklist and transform the node. If the node has changed,
1121 // update edge info and put uses on worklist.
1122 while(_worklist.size()) {
1123 if (C->check_node_count(NodeLimitFudgeFactor * 2, "Out of nodes")) {
1124 return;
1125 }
1126 Node* n = _worklist.pop();
1127 if (++loop_count >= K * C->live_nodes()) {
1128 DEBUG_ONLY(dump_infinite_loop_info(n);)
1129 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize");
1130 return;
1131 }
1132 DEBUG_ONLY(trace_PhaseIterGVN_verbose(n, num_processed++);)
1133 if (n->outcnt() != 0) {
1134 NOT_PRODUCT(const Type* oldtype = type_or_null(n));
1135 // Do the transformation
1136 Node* nn = transform_old(n);
1137 NOT_PRODUCT(trace_PhaseIterGVN(n, nn, oldtype);)
1138 } else if (!n->is_top()) {
1139 remove_dead_node(n);
1140 }
1141 }
1142 NOT_PRODUCT(verify_PhaseIterGVN();)
1143 }
1144
1145
1146 /**
1147 * Register a new node with the optimizer. Update the types array, the def-use
1148 * info. Put on worklist.
1149 */
1150 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) {
1151 set_type_bottom(n);
1152 _worklist.push(n);
1153 if (orig != NULL) C->copy_node_notes_to(n, orig);
1154 return n;
1155 }
1156
1157 //------------------------------transform--------------------------------------
1158 // Non-recursive: idealize Node 'n' with respect to its inputs and its value
1159 Node *PhaseIterGVN::transform( Node *n ) {
1160 if (_delay_transform) {
1161 // Register the node but don't optimize for now
1162 register_new_node_with_optimizer(n);
1163 return n;
1164 }
1165
1166 // If brand new node, make space in type array, and give it a type.
1167 ensure_type_or_null(n);
1168 if (type_or_null(n) == NULL) {
1169 set_type_bottom(n);
1170 }
1171
1172 return transform_old(n);
1173 }
1174
1175 Node *PhaseIterGVN::transform_old(Node* n) {
1176 DEBUG_ONLY(uint loop_count = 0;);
1177 NOT_PRODUCT(set_transforms());
1178
1179 // Remove 'n' from hash table in case it gets modified
1180 _table.hash_delete(n);
1181 if (VerifyIterativeGVN) {
1182 assert(!_table.find_index(n->_idx), "found duplicate entry in table");
1183 }
1184
1185 // Apply the Ideal call in a loop until it no longer applies
1186 Node* k = n;
1187 DEBUG_ONLY(dead_loop_check(k);)
1188 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);)
1189 C->remove_modified_node(k);
1190 Node* i = k->Ideal(this, /*can_reshape=*/true);
1191 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1192 #ifndef PRODUCT
1193 verify_step(k);
1194 if (i && VerifyOpto ) {
1195 if (!allow_progress()) {
1196 if (i->is_Add() && (i->outcnt() == 1)) {
1197 // Switched input to left side because this is the only use
1198 } else if (i->is_If() && (i->in(0) == NULL)) {
1199 // This IF is dead because it is dominated by an equivalent IF When
1200 // dominating if changed, info is not propagated sparsely to 'this'
1201 // Propagating this info further will spuriously identify other
1202 // progress.
1203 return i;
1204 } else
1205 set_progress();
1206 } else {
1207 set_progress();
1208 }
1209 }
1210 #endif
1211
1212 while (i != NULL) {
1213 #ifdef ASSERT
1214 if (loop_count >= K) {
1215 dump_infinite_loop_info(i);
1216 }
1217 loop_count++;
1218 #endif
1219 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes");
1220 // Made a change; put users of original Node on worklist
1221 add_users_to_worklist(k);
1222 // Replacing root of transform tree?
1223 if (k != i) {
1224 // Make users of old Node now use new.
1225 subsume_node(k, i);
1226 k = i;
1227 }
1228 DEBUG_ONLY(dead_loop_check(k);)
1229 // Try idealizing again
1230 DEBUG_ONLY(is_new = (k->outcnt() == 0);)
1231 C->remove_modified_node(k);
1232 i = k->Ideal(this, /*can_reshape=*/true);
1233 assert(i != k || is_new || (i->outcnt() > 0), "don't return dead nodes");
1234 #ifndef PRODUCT
1235 verify_step(k);
1236 if (i && VerifyOpto) {
1237 set_progress();
1238 }
1239 #endif
1240 }
1241
1242 // If brand new node, make space in type array.
1243 ensure_type_or_null(k);
1244
1245 // See what kind of values 'k' takes on at runtime
1246 const Type* t = k->Value(this);
1247 assert(t != NULL, "value sanity");
1248
1249 // Since I just called 'Value' to compute the set of run-time values
1250 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
1251 // cache Value. Later requests for the local phase->type of this Node can
1252 // use the cached Value instead of suffering with 'bottom_type'.
1253 if (type_or_null(k) != t) {
1254 #ifndef PRODUCT
1255 inc_new_values();
1256 set_progress();
1257 #endif
1258 set_type(k, t);
1259 // If k is a TypeNode, capture any more-precise type permanently into Node
1260 k->raise_bottom_type(t);
1261 // Move users of node to worklist
1262 add_users_to_worklist(k);
1263 }
1264 // If 'k' computes a constant, replace it with a constant
1265 if (t->singleton() && !k->is_Con()) {
1266 NOT_PRODUCT(set_progress();)
1267 Node* con = makecon(t); // Make a constant
1268 add_users_to_worklist(k);
1269 subsume_node(k, con); // Everybody using k now uses con
1270 return con;
1271 }
1272
1273 // Now check for Identities
1274 i = k->Identity(this); // Look for a nearby replacement
1275 if (i != k) { // Found? Return replacement!
1276 NOT_PRODUCT(set_progress();)
1277 add_users_to_worklist(k);
1278 subsume_node(k, i); // Everybody using k now uses i
1279 return i;
1280 }
1281
1282 // Global Value Numbering
1283 i = hash_find_insert(k); // Check for pre-existing node
1284 if (i && (i != k)) {
1285 // Return the pre-existing node if it isn't dead
1286 NOT_PRODUCT(set_progress();)
1287 add_users_to_worklist(k);
1288 subsume_node(k, i); // Everybody using k now uses i
1289 return i;
1290 }
1291
1292 // Return Idealized original
1293 return k;
1294 }
1295
1296 //---------------------------------saturate------------------------------------
1297 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type,
1298 const Type* limit_type) const {
1299 return new_type->narrow(old_type);
1300 }
1301
1302 //------------------------------remove_globally_dead_node----------------------
1303 // Kill a globally dead Node. All uses are also globally dead and are
1304 // aggressively trimmed.
1305 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) {
1306 enum DeleteProgress {
1307 PROCESS_INPUTS,
1308 PROCESS_OUTPUTS
1309 };
1310 assert(_stack.is_empty(), "not empty");
1311 _stack.push(dead, PROCESS_INPUTS);
1312
1313 while (_stack.is_nonempty()) {
1314 dead = _stack.node();
1315 uint progress_state = _stack.index();
1316 assert(dead != C->root(), "killing root, eh?");
1317 assert(!dead->is_top(), "add check for top when pushing");
1318 NOT_PRODUCT( set_progress(); )
1319 if (progress_state == PROCESS_INPUTS) {
1320 // After following inputs, continue to outputs
1321 _stack.set_index(PROCESS_OUTPUTS);
1322 if (!dead->is_Con()) { // Don't kill cons but uses
1323 bool recurse = false;
1324 // Remove from hash table
1325 _table.hash_delete( dead );
1326 // Smash all inputs to 'dead', isolating him completely
1327 for (uint i = 0; i < dead->req(); i++) {
1328 Node *in = dead->in(i);
1329 if (in != NULL && in != C->top()) { // Points to something?
1330 int nrep = dead->replace_edge(in, NULL); // Kill edges
1331 assert((nrep > 0), "sanity");
1332 if (in->outcnt() == 0) { // Made input go dead?
1333 _stack.push(in, PROCESS_INPUTS); // Recursively remove
1334 recurse = true;
1335 } else if (in->outcnt() == 1 &&
1336 in->has_special_unique_user()) {
1337 _worklist.push(in->unique_out());
1338 } else if (in->outcnt() <= 2 && dead->is_Phi()) {
1339 if (in->Opcode() == Op_Region) {
1340 _worklist.push(in);
1341 } else if (in->is_Store()) {
1342 DUIterator_Fast imax, i = in->fast_outs(imax);
1343 _worklist.push(in->fast_out(i));
1344 i++;
1345 if (in->outcnt() == 2) {
1346 _worklist.push(in->fast_out(i));
1347 i++;
1348 }
1349 assert(!(i < imax), "sanity");
1350 }
1351 }
1352 if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory &&
1353 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) {
1354 // A Load that directly follows an InitializeNode is
1355 // going away. The Stores that follow are candidates
1356 // again to be captured by the InitializeNode.
1357 for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) {
1358 Node *n = in->fast_out(j);
1359 if (n->is_Store()) {
1360 _worklist.push(n);
1361 }
1362 }
1363 }
1364 } // if (in != NULL && in != C->top())
1365 } // for (uint i = 0; i < dead->req(); i++)
1366 if (recurse) {
1367 continue;
1368 }
1369 } // if (!dead->is_Con())
1370 } // if (progress_state == PROCESS_INPUTS)
1371
1372 // Aggressively kill globally dead uses
1373 // (Rather than pushing all the outs at once, we push one at a time,
1374 // plus the parent to resume later, because of the indefinite number
1375 // of edge deletions per loop trip.)
1376 if (dead->outcnt() > 0) {
1377 // Recursively remove output edges
1378 _stack.push(dead->raw_out(0), PROCESS_INPUTS);
1379 } else {
1380 // Finished disconnecting all input and output edges.
1381 _stack.pop();
1382 // Remove dead node from iterative worklist
1383 _worklist.remove(dead);
1384 C->remove_modified_node(dead);
1385 // Constant node that has no out-edges and has only one in-edge from
1386 // root is usually dead. However, sometimes reshaping walk makes
1387 // it reachable by adding use edges. So, we will NOT count Con nodes
1388 // as dead to be conservative about the dead node count at any
1389 // given time.
1390 if (!dead->is_Con()) {
1391 C->record_dead_node(dead->_idx);
1392 }
1393 if (dead->is_macro()) {
1394 C->remove_macro_node(dead);
1395 }
1396 if (dead->is_expensive()) {
1397 C->remove_expensive_node(dead);
1398 }
1399 }
1400 } // while (_stack.is_nonempty())
1401 }
1402
1403 //------------------------------subsume_node-----------------------------------
1404 // Remove users from node 'old' and add them to node 'nn'.
1405 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
1406 assert( old != hash_find(old), "should already been removed" );
1407 assert( old != C->top(), "cannot subsume top node");
1408 // Copy debug or profile information to the new version:
1409 C->copy_node_notes_to(nn, old);
1410 // Move users of node 'old' to node 'nn'
1411 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) {
1412 Node* use = old->last_out(i); // for each use...
1413 // use might need re-hashing (but it won't if it's a new node)
1414 rehash_node_delayed(use);
1415 // Update use-def info as well
1416 // We remove all occurrences of old within use->in,
1417 // so as to avoid rehashing any node more than once.
1418 // The hash table probe swamps any outer loop overhead.
1419 uint num_edges = 0;
1420 for (uint jmax = use->len(), j = 0; j < jmax; j++) {
1421 if (use->in(j) == old) {
1422 use->set_req(j, nn);
1423 ++num_edges;
1424 }
1425 }
1426 i -= num_edges; // we deleted 1 or more copies of this edge
1427 }
1428
1429 // Smash all inputs to 'old', isolating him completely
1430 Node *temp = new Node(1);
1431 temp->init_req(0,nn); // Add a use to nn to prevent him from dying
1432 remove_dead_node( old );
1433 temp->del_req(0); // Yank bogus edge
1434 #ifndef PRODUCT
1435 if( VerifyIterativeGVN ) {
1436 for ( int i = 0; i < _verify_window_size; i++ ) {
1437 if ( _verify_window[i] == old )
1438 _verify_window[i] = nn;
1439 }
1440 }
1441 #endif
1442 _worklist.remove(temp); // this can be necessary
1443 temp->destruct(); // reuse the _idx of this little guy
1444 }
1445
1446 //------------------------------add_users_to_worklist--------------------------
1447 void PhaseIterGVN::add_users_to_worklist0( Node *n ) {
1448 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1449 _worklist.push(n->fast_out(i)); // Push on worklist
1450 }
1451 }
1452
1453 void PhaseIterGVN::add_users_to_worklist( Node *n ) {
1454 add_users_to_worklist0(n);
1455
1456 // Move users of node to worklist
1457 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1458 Node* use = n->fast_out(i); // Get use
1459
1460 if( use->is_Multi() || // Multi-definer? Push projs on worklist
1461 use->is_Store() ) // Enable store/load same address
1462 add_users_to_worklist0(use);
1463
1464 // If we changed the receiver type to a call, we need to revisit
1465 // the Catch following the call. It's looking for a non-NULL
1466 // receiver to know when to enable the regular fall-through path
1467 // in addition to the NullPtrException path.
1468 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) {
1469 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control);
1470 if (p != NULL) {
1471 add_users_to_worklist0(p);
1472 }
1473 }
1474
1475 uint use_op = use->Opcode();
1476 if(use->is_Cmp()) { // Enable CMP/BOOL optimization
1477 add_users_to_worklist(use); // Put Bool on worklist
1478 if (use->outcnt() > 0) {
1479 Node* bol = use->raw_out(0);
1480 if (bol->outcnt() > 0) {
1481 Node* iff = bol->raw_out(0);
1482 if (use_op == Op_CmpI &&
1483 iff->is_CountedLoopEnd()) {
1484 CountedLoopEndNode* cle = iff->as_CountedLoopEnd();
1485 if (cle->limit() == n && cle->phi() != NULL) {
1486 // If an opaque node feeds into the limit condition of a
1487 // CountedLoop, we need to process the Phi node for the
1488 // induction variable when the opaque node is removed:
1489 // the range of values taken by the Phi is now known and
1490 // so its type is also known.
1491 _worklist.push(cle->phi());
1492 }
1493 } else if (iff->outcnt() == 2) {
1494 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the
1495 // phi merging either 0 or 1 onto the worklist
1496 Node* ifproj0 = iff->raw_out(0);
1497 Node* ifproj1 = iff->raw_out(1);
1498 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) {
1499 Node* region0 = ifproj0->raw_out(0);
1500 Node* region1 = ifproj1->raw_out(0);
1501 if( region0 == region1 )
1502 add_users_to_worklist0(region0);
1503 }
1504 }
1505 }
1506 }
1507 if (use_op == Op_CmpI) {
1508 Node* in1 = use->in(1);
1509 for (uint i = 0; i < in1->outcnt(); i++) {
1510 if (in1->raw_out(i)->Opcode() == Op_CastII) {
1511 Node* castii = in1->raw_out(i);
1512 if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) {
1513 Node* ifnode = castii->in(0)->in(0);
1514 if (ifnode->in(1) != NULL && ifnode->in(1)->is_Bool() && ifnode->in(1)->in(1) == use) {
1515 // Reprocess a CastII node that may depend on an
1516 // opaque node value when the opaque node is
1517 // removed. In case it carries a dependency we can do
1518 // a better job of computing its type.
1519 _worklist.push(castii);
1520 }
1521 }
1522 }
1523 }
1524 }
1525 }
1526
1527 // If changed Cast input, check Phi users for simple cycles
1528 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) {
1529 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1530 Node* u = use->fast_out(i2);
1531 if (u->is_Phi())
1532 _worklist.push(u);
1533 }
1534 }
1535 // If changed LShift inputs, check RShift users for useless sign-ext
1536 if( use_op == Op_LShiftI ) {
1537 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1538 Node* u = use->fast_out(i2);
1539 if (u->Opcode() == Op_RShiftI)
1540 _worklist.push(u);
1541 }
1542 }
1543 // If changed AddI/SubI inputs, check CmpU for range check optimization.
1544 if (use_op == Op_AddI || use_op == Op_SubI) {
1545 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1546 Node* u = use->fast_out(i2);
1547 if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) {
1548 _worklist.push(u);
1549 }
1550 }
1551 }
1552 // If changed AddP inputs, check Stores for loop invariant
1553 if( use_op == Op_AddP ) {
1554 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1555 Node* u = use->fast_out(i2);
1556 if (u->is_Mem())
1557 _worklist.push(u);
1558 }
1559 }
1560 // If changed initialization activity, check dependent Stores
1561 if (use_op == Op_Allocate || use_op == Op_AllocateArray) {
1562 InitializeNode* init = use->as_Allocate()->initialization();
1563 if (init != NULL) {
1564 Node* imem = init->proj_out(TypeFunc::Memory);
1565 if (imem != NULL) add_users_to_worklist0(imem);
1566 }
1567 }
1568 if (use_op == Op_Initialize) {
1569 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory);
1570 if (imem != NULL) add_users_to_worklist0(imem);
1571 }
1572 }
1573 }
1574
1575 /**
1576 * Remove the speculative part of all types that we know of
1577 */
1578 void PhaseIterGVN::remove_speculative_types() {
1579 assert(UseTypeSpeculation, "speculation is off");
1580 for (uint i = 0; i < _types.Size(); i++) {
1581 const Type* t = _types.fast_lookup(i);
1582 if (t != NULL) {
1583 _types.map(i, t->remove_speculative());
1584 }
1585 }
1586 _table.check_no_speculative_types();
1587 }
1588
1589 //=============================================================================
1590 #ifndef PRODUCT
1591 uint PhaseCCP::_total_invokes = 0;
1592 uint PhaseCCP::_total_constants = 0;
1593 #endif
1594 //------------------------------PhaseCCP---------------------------------------
1595 // Conditional Constant Propagation, ala Wegman & Zadeck
1596 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) {
1597 NOT_PRODUCT( clear_constants(); )
1598 assert( _worklist.size() == 0, "" );
1599 // Clear out _nodes from IterGVN. Must be clear to transform call.
1600 _nodes.clear(); // Clear out from IterGVN
1601 analyze();
1602 }
1603
1604 #ifndef PRODUCT
1605 //------------------------------~PhaseCCP--------------------------------------
1606 PhaseCCP::~PhaseCCP() {
1607 inc_invokes();
1608 _total_constants += count_constants();
1609 }
1610 #endif
1611
1612
1613 #ifdef ASSERT
1614 static bool ccp_type_widens(const Type* t, const Type* t0) {
1615 assert(t->meet(t0) == t, "Not monotonic");
1616 switch (t->base() == t0->base() ? t->base() : Type::Top) {
1617 case Type::Int:
1618 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases");
1619 break;
1620 case Type::Long:
1621 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases");
1622 break;
1623 }
1624 return true;
1625 }
1626 #endif //ASSERT
1627
1628 //------------------------------analyze----------------------------------------
1629 void PhaseCCP::analyze() {
1630 // Initialize all types to TOP, optimistic analysis
1631 for (int i = C->unique() - 1; i >= 0; i--) {
1632 _types.map(i,Type::TOP);
1633 }
1634
1635 // Push root onto worklist
1636 Unique_Node_List worklist;
1637 worklist.push(C->root());
1638
1639 // Pull from worklist; compute new value; push changes out.
1640 // This loop is the meat of CCP.
1641 while( worklist.size() ) {
1642 Node *n = worklist.pop();
1643 const Type *t = n->Value(this);
1644 if (t != type(n)) {
1645 assert(ccp_type_widens(t, type(n)), "ccp type must widen");
1646 #ifndef PRODUCT
1647 if( TracePhaseCCP ) {
1648 t->dump();
1649 do { tty->print("\t"); } while (tty->position() < 16);
1650 n->dump();
1651 }
1652 #endif
1653 set_type(n, t);
1654 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1655 Node* m = n->fast_out(i); // Get user
1656 if (m->is_Region()) { // New path to Region? Must recheck Phis too
1657 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1658 Node* p = m->fast_out(i2); // Propagate changes to uses
1659 if (p->bottom_type() != type(p)) { // If not already bottomed out
1660 worklist.push(p); // Propagate change to user
1661 }
1662 }
1663 }
1664 // If we changed the receiver type to a call, we need to revisit
1665 // the Catch following the call. It's looking for a non-NULL
1666 // receiver to know when to enable the regular fall-through path
1667 // in addition to the NullPtrException path
1668 if (m->is_Call()) {
1669 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1670 Node* p = m->fast_out(i2); // Propagate changes to uses
1671 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) {
1672 worklist.push(p->unique_out());
1673 }
1674 }
1675 }
1676 if (m->bottom_type() != type(m)) { // If not already bottomed out
1677 worklist.push(m); // Propagate change to user
1678 }
1679
1680 // CmpU nodes can get their type information from two nodes up in the
1681 // graph (instead of from the nodes immediately above). Make sure they
1682 // are added to the worklist if nodes they depend on are updated, since
1683 // they could be missed and get wrong types otherwise.
1684 uint m_op = m->Opcode();
1685 if (m_op == Op_AddI || m_op == Op_SubI) {
1686 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1687 Node* p = m->fast_out(i2); // Propagate changes to uses
1688 if (p->Opcode() == Op_CmpU) {
1689 // Got a CmpU which might need the new type information from node n.
1690 if(p->bottom_type() != type(p)) { // If not already bottomed out
1691 worklist.push(p); // Propagate change to user
1692 }
1693 }
1694 }
1695 }
1696 }
1697 }
1698 }
1699 }
1700
1701 //------------------------------do_transform-----------------------------------
1702 // Top level driver for the recursive transformer
1703 void PhaseCCP::do_transform() {
1704 // Correct leaves of new-space Nodes; they point to old-space.
1705 C->set_root( transform(C->root())->as_Root() );
1706 assert( C->top(), "missing TOP node" );
1707 assert( C->root(), "missing root" );
1708 }
1709
1710 //------------------------------transform--------------------------------------
1711 // Given a Node in old-space, clone him into new-space.
1712 // Convert any of his old-space children into new-space children.
1713 Node *PhaseCCP::transform( Node *n ) {
1714 Node *new_node = _nodes[n->_idx]; // Check for transformed node
1715 if( new_node != NULL )
1716 return new_node; // Been there, done that, return old answer
1717 new_node = transform_once(n); // Check for constant
1718 _nodes.map( n->_idx, new_node ); // Flag as having been cloned
1719
1720 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc
1721 GrowableArray <Node *> trstack(C->live_nodes() >> 1);
1722
1723 trstack.push(new_node); // Process children of cloned node
1724 while ( trstack.is_nonempty() ) {
1725 Node *clone = trstack.pop();
1726 uint cnt = clone->req();
1727 for( uint i = 0; i < cnt; i++ ) { // For all inputs do
1728 Node *input = clone->in(i);
1729 if( input != NULL ) { // Ignore NULLs
1730 Node *new_input = _nodes[input->_idx]; // Check for cloned input node
1731 if( new_input == NULL ) {
1732 new_input = transform_once(input); // Check for constant
1733 _nodes.map( input->_idx, new_input );// Flag as having been cloned
1734 trstack.push(new_input);
1735 }
1736 assert( new_input == clone->in(i), "insanity check");
1737 }
1738 }
1739 }
1740 return new_node;
1741 }
1742
1743
1744 //------------------------------transform_once---------------------------------
1745 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant.
1746 Node *PhaseCCP::transform_once( Node *n ) {
1747 const Type *t = type(n);
1748 // Constant? Use constant Node instead
1749 if( t->singleton() ) {
1750 Node *nn = n; // Default is to return the original constant
1751 if( t == Type::TOP ) {
1752 // cache my top node on the Compile instance
1753 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) {
1754 C->set_cached_top_node(ConNode::make(Type::TOP));
1755 set_type(C->top(), Type::TOP);
1756 }
1757 nn = C->top();
1758 }
1759 if( !n->is_Con() ) {
1760 if( t != Type::TOP ) {
1761 nn = makecon(t); // ConNode::make(t);
1762 NOT_PRODUCT( inc_constants(); )
1763 } else if( n->is_Region() ) { // Unreachable region
1764 // Note: nn == C->top()
1765 n->set_req(0, NULL); // Cut selfreference
1766 // Eagerly remove dead phis to avoid phis copies creation.
1767 for (DUIterator i = n->outs(); n->has_out(i); i++) {
1768 Node* m = n->out(i);
1769 if( m->is_Phi() ) {
1770 assert(type(m) == Type::TOP, "Unreachable region should not have live phis.");
1771 replace_node(m, nn);
1772 --i; // deleted this phi; rescan starting with next position
1773 }
1774 }
1775 }
1776 replace_node(n,nn); // Update DefUse edges for new constant
1777 }
1778 return nn;
1779 }
1780
1781 // If x is a TypeNode, capture any more-precise type permanently into Node
1782 if (t != n->bottom_type()) {
1783 hash_delete(n); // changing bottom type may force a rehash
1784 n->raise_bottom_type(t);
1785 _worklist.push(n); // n re-enters the hash table via the worklist
1786 }
1787
1788 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks
1789 switch( n->Opcode() ) {
1790 case Op_FastLock: // Revisit FastLocks for lock coarsening
1791 case Op_If:
1792 case Op_CountedLoopEnd:
1793 case Op_Region:
1794 case Op_Loop:
1795 case Op_CountedLoop:
1796 case Op_Conv2B:
1797 case Op_Opaque1:
1798 case Op_Opaque2:
1799 _worklist.push(n);
1800 break;
1801 default:
1802 break;
1803 }
1804
1805 return n;
1806 }
1807
1808 //---------------------------------saturate------------------------------------
1809 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type,
1810 const Type* limit_type) const {
1811 const Type* wide_type = new_type->widen(old_type, limit_type);
1812 if (wide_type != new_type) { // did we widen?
1813 // If so, we may have widened beyond the limit type. Clip it back down.
1814 new_type = wide_type->filter(limit_type);
1815 }
1816 return new_type;
1817 }
1818
1819 //------------------------------print_statistics-------------------------------
1820 #ifndef PRODUCT
1821 void PhaseCCP::print_statistics() {
1822 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants);
1823 }
1824 #endif
1825
1826
1827 //=============================================================================
1828 #ifndef PRODUCT
1829 uint PhasePeephole::_total_peepholes = 0;
1830 #endif
1831 //------------------------------PhasePeephole----------------------------------
1832 // Conditional Constant Propagation, ala Wegman & Zadeck
1833 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg )
1834 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) {
1835 NOT_PRODUCT( clear_peepholes(); )
1836 }
1837
1838 #ifndef PRODUCT
1839 //------------------------------~PhasePeephole---------------------------------
1840 PhasePeephole::~PhasePeephole() {
1841 _total_peepholes += count_peepholes();
1842 }
1843 #endif
1844
1845 //------------------------------transform--------------------------------------
1846 Node *PhasePeephole::transform( Node *n ) {
1847 ShouldNotCallThis();
1848 return NULL;
1849 }
1850
1851 //------------------------------do_transform-----------------------------------
1852 void PhasePeephole::do_transform() {
1853 bool method_name_not_printed = true;
1854
1855 // Examine each basic block
1856 for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) {
1857 Block* block = _cfg.get_block(block_number);
1858 bool block_not_printed = true;
1859
1860 // and each instruction within a block
1861 uint end_index = block->number_of_nodes();
1862 // block->end_idx() not valid after PhaseRegAlloc
1863 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) {
1864 Node *n = block->get_node(instruction_index);
1865 if( n->is_Mach() ) {
1866 MachNode *m = n->as_Mach();
1867 int deleted_count = 0;
1868 // check for peephole opportunities
1869 MachNode *m2 = m->peephole(block, instruction_index, _regalloc, deleted_count);
1870 if( m2 != NULL ) {
1871 #ifndef PRODUCT
1872 if( PrintOptoPeephole ) {
1873 // Print method, first time only
1874 if( C->method() && method_name_not_printed ) {
1875 C->method()->print_short_name(); tty->cr();
1876 method_name_not_printed = false;
1877 }
1878 // Print this block
1879 if( Verbose && block_not_printed) {
1880 tty->print_cr("in block");
1881 block->dump();
1882 block_not_printed = false;
1883 }
1884 // Print instructions being deleted
1885 for( int i = (deleted_count - 1); i >= 0; --i ) {
1886 block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr();
1887 }
1888 tty->print_cr("replaced with");
1889 // Print new instruction
1890 m2->format(_regalloc);
1891 tty->print("\n\n");
1892 }
1893 #endif
1894 // Remove old nodes from basic block and update instruction_index
1895 // (old nodes still exist and may have edges pointing to them
1896 // as register allocation info is stored in the allocator using
1897 // the node index to live range mappings.)
1898 uint safe_instruction_index = (instruction_index - deleted_count);
1899 for( ; (instruction_index > safe_instruction_index); --instruction_index ) {
1900 block->remove_node( instruction_index );
1901 }
1902 // install new node after safe_instruction_index
1903 block->insert_node(m2, safe_instruction_index + 1);
1904 end_index = block->number_of_nodes() - 1; // Recompute new block size
1905 NOT_PRODUCT( inc_peepholes(); )
1906 }
1907 }
1908 }
1909 }
1910 }
1911
1912 //------------------------------print_statistics-------------------------------
1913 #ifndef PRODUCT
1914 void PhasePeephole::print_statistics() {
1915 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes);
1916 }
1917 #endif
1918
1919
1920 //=============================================================================
1921 //------------------------------set_req_X--------------------------------------
1922 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1923 assert( is_not_dead(n), "can not use dead node");
1924 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1925 Node *old = in(i);
1926 set_req(i, n);
1927
1928 // old goes dead?
1929 if( old ) {
1930 switch (old->outcnt()) {
1931 case 0:
1932 // Put into the worklist to kill later. We do not kill it now because the
1933 // recursive kill will delete the current node (this) if dead-loop exists
1934 if (!old->is_top())
1935 igvn->_worklist.push( old );
1936 break;
1937 case 1:
1938 if( old->is_Store() || old->has_special_unique_user() )
1939 igvn->add_users_to_worklist( old );
1940 break;
1941 case 2:
1942 if( old->is_Store() )
1943 igvn->add_users_to_worklist( old );
1944 if( old->Opcode() == Op_Region )
1945 igvn->_worklist.push(old);
1946 break;
1947 case 3:
1948 if( old->Opcode() == Op_Region ) {
1949 igvn->_worklist.push(old);
1950 igvn->add_users_to_worklist( old );
1951 }
1952 break;
1953 default:
1954 break;
1955 }
1956 }
1957
1958 }
1959
1960 //-------------------------------replace_by-----------------------------------
1961 // Using def-use info, replace one node for another. Follow the def-use info
1962 // to all users of the OLD node. Then make all uses point to the NEW node.
1963 void Node::replace_by(Node *new_node) {
1964 assert(!is_top(), "top node has no DU info");
1965 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) {
1966 Node* use = last_out(i);
1967 uint uses_found = 0;
1968 for (uint j = 0; j < use->len(); j++) {
1969 if (use->in(j) == this) {
1970 if (j < use->req())
1971 use->set_req(j, new_node);
1972 else use->set_prec(j, new_node);
1973 uses_found++;
1974 }
1975 }
1976 i -= uses_found; // we deleted 1 or more copies of this edge
1977 }
1978 }
1979
1980 //=============================================================================
1981 //-----------------------------------------------------------------------------
1982 void Type_Array::grow( uint i ) {
1983 if( !_max ) {
1984 _max = 1;
1985 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) );
1986 _types[0] = NULL;
1987 }
1988 uint old = _max;
1989 while( i >= _max ) _max <<= 1; // Double to fit
1990 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*));
1991 memset( &_types[old], 0, (_max-old)*sizeof(Type*) );
1992 }
1993
1994 //------------------------------dump-------------------------------------------
1995 #ifndef PRODUCT
1996 void Type_Array::dump() const {
1997 uint max = Size();
1998 for( uint i = 0; i < max; i++ ) {
1999 if( _types[i] != NULL ) {
2000 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr();
2001 }
2002 }
2003 }
2004 #endif