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/castnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/idealGraphPrinter.hpp"
32 #include "opto/loopnode.hpp"
33 #include "opto/machnode.hpp"
34 #include "opto/opcodes.hpp"
35 #include "opto/phaseX.hpp"
36 #include "opto/regalloc.hpp"
37 #include "opto/rootnode.hpp"
38
39 //=============================================================================
40 #define NODE_HASH_MINIMUM_SIZE 255
41 //------------------------------NodeHash---------------------------------------
42 NodeHash::NodeHash(uint est_max_size) :
43 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
44 _a(Thread::current()->resource_area()),
45 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ), // (Node**)_a->Amalloc(_max * sizeof(Node*)) ),
46 _inserts(0), _insert_limit( insert_limit() )
47 #ifndef PRODUCT
48 ,_look_probes(0), _lookup_hits(0), _lookup_misses(0),
49 _delete_probes(0), _delete_hits(0), _delete_misses(0),
50 _total_insert_probes(0), _total_inserts(0),
51 _insert_probes(0), _grows(0)
52 #endif
53 {
54 // _sentinel must be in the current node space
55 _sentinel = new ProjNode(NULL, TypeFunc::Control);
56 memset(_table,0,sizeof(Node*)*_max);
57 }
58
59 //------------------------------NodeHash---------------------------------------
60 NodeHash::NodeHash(Arena *arena, uint est_max_size) :
61 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
62 _a(arena),
63 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ),
64 _inserts(0), _insert_limit( insert_limit() )
65 #ifndef PRODUCT
66 ,_look_probes(0), _lookup_hits(0), _lookup_misses(0),
67 _delete_probes(0), _delete_hits(0), _delete_misses(0),
68 _total_insert_probes(0), _total_inserts(0),
69 _insert_probes(0), _grows(0)
70 #endif
71 {
72 // _sentinel must be in the current node space
73 _sentinel = new ProjNode(NULL, TypeFunc::Control);
74 memset(_table,0,sizeof(Node*)*_max);
75 }
76
77 //------------------------------NodeHash---------------------------------------
78 NodeHash::NodeHash(NodeHash *nh) {
79 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator=
80 // just copy in all the fields
81 *this = *nh;
82 // nh->_sentinel must be in the current node space
83 }
84
85 void NodeHash::replace_with(NodeHash *nh) {
86 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator=
87 // just copy in all the fields
88 *this = *nh;
89 // nh->_sentinel must be in the current node space
90 }
91
92 //------------------------------hash_find--------------------------------------
93 // Find in hash table
94 Node *NodeHash::hash_find( const Node *n ) {
95 // ((Node*)n)->set_hash( n->hash() );
96 uint hash = n->hash();
97 if (hash == Node::NO_HASH) {
98 NOT_PRODUCT( _lookup_misses++ );
99 return NULL;
100 }
101 uint key = hash & (_max-1);
102 uint stride = key | 0x01;
103 NOT_PRODUCT( _look_probes++ );
104 Node *k = _table[key]; // Get hashed value
105 if( !k ) { // ?Miss?
106 NOT_PRODUCT( _lookup_misses++ );
107 return NULL; // Miss!
108 }
109
110 int op = n->Opcode();
111 uint req = n->req();
112 while( 1 ) { // While probing hash table
113 if( k->req() == req && // Same count of inputs
114 k->Opcode() == op ) { // Same Opcode
115 for( uint i=0; i<req; i++ )
116 if( n->in(i)!=k->in(i)) // Different inputs?
117 goto collision; // "goto" is a speed hack...
118 if( n->cmp(*k) ) { // Check for any special bits
119 NOT_PRODUCT( _lookup_hits++ );
120 return k; // Hit!
121 }
122 }
123 collision:
124 NOT_PRODUCT( _look_probes++ );
125 key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime
126 k = _table[key]; // Get hashed value
127 if( !k ) { // ?Miss?
128 NOT_PRODUCT( _lookup_misses++ );
129 return NULL; // Miss!
130 }
131 }
132 ShouldNotReachHere();
133 return NULL;
134 }
135
136 //------------------------------hash_find_insert-------------------------------
137 // Find in hash table, insert if not already present
138 // Used to preserve unique entries in hash table
139 Node *NodeHash::hash_find_insert( Node *n ) {
140 // n->set_hash( );
141 uint hash = n->hash();
142 if (hash == Node::NO_HASH) {
143 NOT_PRODUCT( _lookup_misses++ );
144 return NULL;
145 }
146 uint key = hash & (_max-1);
147 uint stride = key | 0x01; // stride must be relatively prime to table siz
148 uint first_sentinel = 0; // replace a sentinel if seen.
149 NOT_PRODUCT( _look_probes++ );
150 Node *k = _table[key]; // Get hashed value
151 if( !k ) { // ?Miss?
152 NOT_PRODUCT( _lookup_misses++ );
153 _table[key] = n; // Insert into table!
154 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
155 check_grow(); // Grow table if insert hit limit
156 return NULL; // Miss!
157 }
158 else if( k == _sentinel ) {
159 first_sentinel = key; // Can insert here
160 }
161
162 int op = n->Opcode();
163 uint req = n->req();
164 while( 1 ) { // While probing hash table
165 if( k->req() == req && // Same count of inputs
166 k->Opcode() == op ) { // Same Opcode
167 for( uint i=0; i<req; i++ )
168 if( n->in(i)!=k->in(i)) // Different inputs?
169 goto collision; // "goto" is a speed hack...
170 if( n->cmp(*k) ) { // Check for any special bits
171 NOT_PRODUCT( _lookup_hits++ );
172 return k; // Hit!
173 }
174 }
175 collision:
176 NOT_PRODUCT( _look_probes++ );
177 key = (key + stride) & (_max-1); // Stride through table w/ relative prime
178 k = _table[key]; // Get hashed value
179 if( !k ) { // ?Miss?
180 NOT_PRODUCT( _lookup_misses++ );
181 key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel?
182 _table[key] = n; // Insert into table!
183 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
184 check_grow(); // Grow table if insert hit limit
185 return NULL; // Miss!
186 }
187 else if( first_sentinel == 0 && k == _sentinel ) {
188 first_sentinel = key; // Can insert here
189 }
190
191 }
192 ShouldNotReachHere();
193 return NULL;
194 }
195
196 //------------------------------hash_insert------------------------------------
197 // Insert into hash table
198 void NodeHash::hash_insert( Node *n ) {
199 // // "conflict" comments -- print nodes that conflict
200 // bool conflict = false;
201 // n->set_hash();
202 uint hash = n->hash();
203 if (hash == Node::NO_HASH) {
204 return;
205 }
206 check_grow();
207 uint key = hash & (_max-1);
208 uint stride = key | 0x01;
209
210 while( 1 ) { // While probing hash table
211 NOT_PRODUCT( _insert_probes++ );
212 Node *k = _table[key]; // Get hashed value
213 if( !k || (k == _sentinel) ) break; // Found a slot
214 assert( k != n, "already inserted" );
215 // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; }
216 key = (key + stride) & (_max-1); // Stride through table w/ relative prime
217 }
218 _table[key] = n; // Insert into table!
219 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
220 // if( conflict ) { n->dump(); }
221 }
222
223 //------------------------------hash_delete------------------------------------
224 // Replace in hash table with sentinel
225 bool NodeHash::hash_delete( const Node *n ) {
226 Node *k;
227 uint hash = n->hash();
228 if (hash == Node::NO_HASH) {
229 NOT_PRODUCT( _delete_misses++ );
230 return false;
231 }
232 uint key = hash & (_max-1);
233 uint stride = key | 0x01;
234 debug_only( uint counter = 0; );
235 for( ; /* (k != NULL) && (k != _sentinel) */; ) {
236 debug_only( counter++ );
237 NOT_PRODUCT( _delete_probes++ );
238 k = _table[key]; // Get hashed value
239 if( !k ) { // Miss?
240 NOT_PRODUCT( _delete_misses++ );
241 #ifdef ASSERT
242 if( VerifyOpto ) {
243 for( uint i=0; i < _max; i++ )
244 assert( _table[i] != n, "changed edges with rehashing" );
245 }
246 #endif
247 return false; // Miss! Not in chain
248 }
249 else if( n == k ) {
250 NOT_PRODUCT( _delete_hits++ );
251 _table[key] = _sentinel; // Hit! Label as deleted entry
252 debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table.
253 return true;
254 }
255 else {
256 // collision: move through table with prime offset
257 key = (key + stride/*7*/) & (_max-1);
258 assert( counter <= _insert_limit, "Cycle in hash-table");
259 }
260 }
261 ShouldNotReachHere();
262 return false;
263 }
264
265 //------------------------------round_up---------------------------------------
266 // Round up to nearest power of 2
267 uint NodeHash::round_up( uint x ) {
268 x += (x>>2); // Add 25% slop
269 if( x <16 ) return 16; // Small stuff
270 uint i=16;
271 while( i < x ) i <<= 1; // Double to fit
272 return i; // Return hash table size
273 }
274
275 //------------------------------grow-------------------------------------------
276 // Grow _table to next power of 2 and insert old entries
277 void NodeHash::grow() {
278 // Record old state
279 uint old_max = _max;
280 Node **old_table = _table;
281 // Construct new table with twice the space
282 #ifndef PRODUCT
283 _grows++;
284 _total_inserts += _inserts;
285 _total_insert_probes += _insert_probes;
286 _insert_probes = 0;
287 #endif
288 _inserts = 0;
289 _max = _max << 1;
290 _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) );
291 memset(_table,0,sizeof(Node*)*_max);
292 _insert_limit = insert_limit();
293 // Insert old entries into the new table
294 for( uint i = 0; i < old_max; i++ ) {
295 Node *m = *old_table++;
296 if( !m || m == _sentinel ) continue;
297 debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table.
298 hash_insert(m);
299 }
300 }
301
302 //------------------------------clear------------------------------------------
303 // Clear all entries in _table to NULL but keep storage
304 void NodeHash::clear() {
305 #ifdef ASSERT
306 // Unlock all nodes upon removal from table.
307 for (uint i = 0; i < _max; i++) {
308 Node* n = _table[i];
309 if (!n || n == _sentinel) continue;
310 n->exit_hash_lock();
311 }
312 #endif
313
314 memset( _table, 0, _max * sizeof(Node*) );
315 }
316
317 //-----------------------remove_useless_nodes----------------------------------
318 // Remove useless nodes from value table,
319 // implementation does not depend on hash function
320 void NodeHash::remove_useless_nodes(VectorSet &useful) {
321
322 // Dead nodes in the hash table inherited from GVN should not replace
323 // existing nodes, remove dead nodes.
324 uint max = size();
325 Node *sentinel_node = sentinel();
326 for( uint i = 0; i < max; ++i ) {
327 Node *n = at(i);
328 if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) {
329 debug_only(n->exit_hash_lock()); // Unlock the node when removed
330 _table[i] = sentinel_node; // Replace with placeholder
331 }
332 }
333 }
334
335
336 void NodeHash::check_no_speculative_types() {
337 #ifdef ASSERT
338 uint max = size();
339 Node *sentinel_node = sentinel();
340 for (uint i = 0; i < max; ++i) {
341 Node *n = at(i);
342 if(n != NULL && n != sentinel_node && n->is_Type() && n->outcnt() > 0) {
343 TypeNode* tn = n->as_Type();
344 const Type* t = tn->type();
345 const Type* t_no_spec = t->remove_speculative();
346 assert(t == t_no_spec, "dead node in hash table or missed node during speculative cleanup");
347 }
348 }
349 #endif
350 }
351
352 #ifndef PRODUCT
353 //------------------------------dump-------------------------------------------
354 // Dump statistics for the hash table
355 void NodeHash::dump() {
356 _total_inserts += _inserts;
357 _total_insert_probes += _insert_probes;
358 if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) {
359 if (WizardMode) {
360 for (uint i=0; i<_max; i++) {
361 if (_table[i])
362 tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx);
363 }
364 }
365 tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max);
366 tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0);
367 tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses));
368 tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts);
369 // sentinels increase lookup cost, but not insert cost
370 assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function");
371 assert( _inserts+(_inserts>>3) < _max, "table too full" );
372 assert( _inserts*3+100 >= _insert_probes, "bad hash function" );
373 }
374 }
375
376 Node *NodeHash::find_index(uint idx) { // For debugging
377 // Find an entry by its index value
378 for( uint i = 0; i < _max; i++ ) {
379 Node *m = _table[i];
380 if( !m || m == _sentinel ) continue;
381 if( m->_idx == (uint)idx ) return m;
382 }
383 return NULL;
384 }
385 #endif
386
387 #ifdef ASSERT
388 NodeHash::~NodeHash() {
389 // Unlock all nodes upon destruction of table.
390 if (_table != (Node**)badAddress) clear();
391 }
392
393 void NodeHash::operator=(const NodeHash& nh) {
394 // Unlock all nodes upon replacement of table.
395 if (&nh == this) return;
396 if (_table != (Node**)badAddress) clear();
397 memcpy(this, &nh, sizeof(*this));
398 // Do not increment hash_lock counts again.
399 // Instead, be sure we never again use the source table.
400 ((NodeHash*)&nh)->_table = (Node**)badAddress;
401 }
402
403
404 #endif
405
406
407 //=============================================================================
408 //------------------------------PhaseRemoveUseless-----------------------------
409 // 1) Use a breadthfirst walk to collect useful nodes reachable from root.
410 PhaseRemoveUseless::PhaseRemoveUseless(PhaseGVN *gvn, Unique_Node_List *worklist, PhaseNumber phase_num) : Phase(phase_num),
411 _useful(Thread::current()->resource_area()) {
412
413 // Implementation requires 'UseLoopSafepoints == true' and an edge from root
414 // to each SafePointNode at a backward branch. Inserted in add_safepoint().
415 if( !UseLoopSafepoints || !OptoRemoveUseless ) return;
416
417 // Identify nodes that are reachable from below, useful.
418 C->identify_useful_nodes(_useful);
419 // Update dead node list
420 C->update_dead_node_list(_useful);
421
422 // Remove all useless nodes from PhaseValues' recorded types
423 // Must be done before disconnecting nodes to preserve hash-table-invariant
424 gvn->remove_useless_nodes(_useful.member_set());
425
426 // Remove all useless nodes from future worklist
427 worklist->remove_useless_nodes(_useful.member_set());
428
429 // Disconnect 'useless' nodes that are adjacent to useful nodes
430 C->remove_useless_nodes(_useful);
431
432 // Remove edges from "root" to each SafePoint at a backward branch.
433 // They were inserted during parsing (see add_safepoint()) to make infinite
434 // loops without calls or exceptions visible to root, i.e., useful.
435 Node *root = C->root();
436 if( root != NULL ) {
437 for( uint i = root->req(); i < root->len(); ++i ) {
438 Node *n = root->in(i);
439 if( n != NULL && n->is_SafePoint() ) {
440 root->rm_prec(i);
441 --i;
442 }
443 }
444 }
445 }
446
447 //=============================================================================
448 //------------------------------PhaseRenumberLive------------------------------
449 // First, remove useless nodes (equivalent to identifying live nodes).
450 // Then, renumber live nodes.
451 //
452 // The set of live nodes is returned by PhaseRemoveUseless in the _useful structure.
453 // If the number of live nodes is 'x' (where 'x' == _useful.size()), then the
454 // PhaseRenumberLive updates the node ID of each node (the _idx field) with a unique
455 // value in the range [0, x).
456 //
457 // At the end of the PhaseRenumberLive phase, the compiler's count of unique nodes is
458 // updated to 'x' and the list of dead nodes is reset (as there are no dead nodes).
459 //
460 // The PhaseRenumberLive phase updates two data structures with the new node IDs.
461 // (1) The worklist is used by the PhaseIterGVN phase to identify nodes that must be
462 // processed. A new worklist (with the updated node IDs) is returned in 'new_worklist'.
463 // (2) Type information (the field PhaseGVN::_types) maps type information to each
464 // node ID. The mapping is updated to use the new node IDs as well. Updated type
465 // information is returned in PhaseGVN::_types.
466 //
467 // The PhaseRenumberLive phase does not preserve the order of elements in the worklist.
468 //
469 // Other data structures used by the compiler are not updated. The hash table for value
470 // numbering (the field PhaseGVN::_table) is not updated because computing the hash
471 // values is not based on node IDs. The field PhaseGVN::_nodes is not updated either
472 // because it is empty wherever PhaseRenumberLive is used.
473 PhaseRenumberLive::PhaseRenumberLive(PhaseGVN* gvn,
474 Unique_Node_List* worklist, Unique_Node_List* new_worklist,
475 PhaseNumber phase_num) :
476 PhaseRemoveUseless(gvn, worklist, Remove_Useless_And_Renumber_Live) {
477
478 assert(RenumberLiveNodes, "RenumberLiveNodes must be set to true for node renumbering to take place");
479 assert(C->live_nodes() == _useful.size(), "the number of live nodes must match the number of useful nodes");
480 assert(gvn->nodes_size() == 0, "GVN must not contain any nodes at this point");
481
482 uint old_unique_count = C->unique();
483 uint live_node_count = C->live_nodes();
484 uint worklist_size = worklist->size();
485
486 // Storage for the updated type information.
487 Type_Array new_type_array(C->comp_arena());
488
489 // Iterate over the set of live nodes.
490 uint current_idx = 0; // The current new node ID. Incremented after every assignment.
491 for (uint i = 0; i < _useful.size(); i++) {
492 Node* n = _useful.at(i);
493 const Type* type = gvn->type_or_null(n);
494 new_type_array.map(current_idx, type);
495
496 bool in_worklist = false;
497 if (worklist->member(n)) {
498 in_worklist = true;
499 }
500
501 n->set_idx(current_idx); // Update node ID.
502
503 if (in_worklist) {
504 new_worklist->push(n);
505 }
506
507 current_idx++;
508 }
509
510 assert(worklist_size == new_worklist->size(), "the new worklist must have the same size as the original worklist");
511 assert(live_node_count == current_idx, "all live nodes must be processed");
512
513 // Replace the compiler's type information with the updated type information.
514 gvn->replace_types(new_type_array);
515
516 // Update the unique node count of the compilation to the number of currently live nodes.
517 C->set_unique(live_node_count);
518
519 // Set the dead node count to 0 and reset dead node list.
520 C->reset_dead_node_list();
521 }
522
523
524 //=============================================================================
525 //------------------------------PhaseTransform---------------------------------
526 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum),
527 _arena(Thread::current()->resource_area()),
528 _nodes(_arena),
529 _types(_arena)
530 {
531 init_con_caches();
532 #ifndef PRODUCT
533 clear_progress();
534 clear_transforms();
535 set_allow_progress(true);
536 #endif
537 // Force allocation for currently existing nodes
538 _types.map(C->unique(), NULL);
539 }
540
541 //------------------------------PhaseTransform---------------------------------
542 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum),
543 _arena(arena),
544 _nodes(arena),
545 _types(arena)
546 {
547 init_con_caches();
548 #ifndef PRODUCT
549 clear_progress();
550 clear_transforms();
551 set_allow_progress(true);
552 #endif
553 // Force allocation for currently existing nodes
554 _types.map(C->unique(), NULL);
555 }
556
557 //------------------------------PhaseTransform---------------------------------
558 // Initialize with previously generated type information
559 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum),
560 _arena(pt->_arena),
561 _nodes(pt->_nodes),
562 _types(pt->_types)
563 {
564 init_con_caches();
565 #ifndef PRODUCT
566 clear_progress();
567 clear_transforms();
568 set_allow_progress(true);
569 #endif
570 }
571
572 void PhaseTransform::init_con_caches() {
573 memset(_icons,0,sizeof(_icons));
574 memset(_lcons,0,sizeof(_lcons));
575 memset(_zcons,0,sizeof(_zcons));
576 }
577
578
579 //--------------------------------find_int_type--------------------------------
580 const TypeInt* PhaseTransform::find_int_type(Node* n) {
581 if (n == NULL) return NULL;
582 // Call type_or_null(n) to determine node's type since we might be in
583 // parse phase and call n->Value() may return wrong type.
584 // (For example, a phi node at the beginning of loop parsing is not ready.)
585 const Type* t = type_or_null(n);
586 if (t == NULL) return NULL;
587 return t->isa_int();
588 }
589
590
591 //-------------------------------find_long_type--------------------------------
592 const TypeLong* PhaseTransform::find_long_type(Node* n) {
593 if (n == NULL) return NULL;
594 // (See comment above on type_or_null.)
595 const Type* t = type_or_null(n);
596 if (t == NULL) return NULL;
597 return t->isa_long();
598 }
599
600
601 #ifndef PRODUCT
602 void PhaseTransform::dump_old2new_map() const {
603 _nodes.dump();
604 }
605
606 void PhaseTransform::dump_new( uint nidx ) const {
607 for( uint i=0; i<_nodes.Size(); i++ )
608 if( _nodes[i] && _nodes[i]->_idx == nidx ) {
609 _nodes[i]->dump();
610 tty->cr();
611 tty->print_cr("Old index= %d",i);
612 return;
613 }
614 tty->print_cr("Node %d not found in the new indices", nidx);
615 }
616
617 //------------------------------dump_types-------------------------------------
618 void PhaseTransform::dump_types( ) const {
619 _types.dump();
620 }
621
622 //------------------------------dump_nodes_and_types---------------------------
623 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) {
624 VectorSet visited(Thread::current()->resource_area());
625 dump_nodes_and_types_recur( root, depth, only_ctrl, visited );
626 }
627
628 //------------------------------dump_nodes_and_types_recur---------------------
629 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) {
630 if( !n ) return;
631 if( depth == 0 ) return;
632 if( visited.test_set(n->_idx) ) return;
633 for( uint i=0; i<n->len(); i++ ) {
634 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue;
635 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited );
636 }
637 n->dump();
638 if (type_or_null(n) != NULL) {
639 tty->print(" "); type(n)->dump(); tty->cr();
640 }
641 }
642
643 #endif
644
645
646 //=============================================================================
647 //------------------------------PhaseValues------------------------------------
648 // Set minimum table size to "255"
649 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) {
650 NOT_PRODUCT( clear_new_values(); )
651 }
652
653 //------------------------------PhaseValues------------------------------------
654 // Set minimum table size to "255"
655 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ),
656 _table(&ptv->_table) {
657 NOT_PRODUCT( clear_new_values(); )
658 }
659
660 //------------------------------PhaseValues------------------------------------
661 // Used by +VerifyOpto. Clear out hash table but copy _types array.
662 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ),
663 _table(ptv->arena(),ptv->_table.size()) {
664 NOT_PRODUCT( clear_new_values(); )
665 }
666
667 //------------------------------~PhaseValues-----------------------------------
668 #ifndef PRODUCT
669 PhaseValues::~PhaseValues() {
670 _table.dump();
671
672 // Statistics for value progress and efficiency
673 if( PrintCompilation && Verbose && WizardMode ) {
674 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)",
675 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values());
676 if( made_transforms() != 0 ) {
677 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() );
678 } else {
679 tty->cr();
680 }
681 }
682 }
683 #endif
684
685 //------------------------------makecon----------------------------------------
686 ConNode* PhaseTransform::makecon(const Type *t) {
687 assert(t->singleton(), "must be a constant");
688 assert(!t->empty() || t == Type::TOP, "must not be vacuous range");
689 switch (t->base()) { // fast paths
690 case Type::Half:
691 case Type::Top: return (ConNode*) C->top();
692 case Type::Int: return intcon( t->is_int()->get_con() );
693 case Type::Long: return longcon( t->is_long()->get_con() );
694 }
695 if (t->is_zero_type())
696 return zerocon(t->basic_type());
697 return uncached_makecon(t);
698 }
699
700 //--------------------------uncached_makecon-----------------------------------
701 // Make an idealized constant - one of ConINode, ConPNode, etc.
702 ConNode* PhaseValues::uncached_makecon(const Type *t) {
703 assert(t->singleton(), "must be a constant");
704 ConNode* x = ConNode::make(t);
705 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering
706 if (k == NULL) {
707 set_type(x, t); // Missed, provide type mapping
708 GrowableArray<Node_Notes*>* nna = C->node_note_array();
709 if (nna != NULL) {
710 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true);
711 loc->clear(); // do not put debug info on constants
712 }
713 } else {
714 x->destruct(); // Hit, destroy duplicate constant
715 x = k; // use existing constant
716 }
717 return x;
718 }
719
720 //------------------------------intcon-----------------------------------------
721 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))"
722 ConINode* PhaseTransform::intcon(int i) {
723 // Small integer? Check cache! Check that cached node is not dead
724 if (i >= _icon_min && i <= _icon_max) {
725 ConINode* icon = _icons[i-_icon_min];
726 if (icon != NULL && icon->in(TypeFunc::Control) != NULL)
727 return icon;
728 }
729 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i));
730 assert(icon->is_Con(), "");
731 if (i >= _icon_min && i <= _icon_max)
732 _icons[i-_icon_min] = icon; // Cache small integers
733 return icon;
734 }
735
736 //------------------------------longcon----------------------------------------
737 // Fast long constant.
738 ConLNode* PhaseTransform::longcon(jlong l) {
739 // Small integer? Check cache! Check that cached node is not dead
740 if (l >= _lcon_min && l <= _lcon_max) {
741 ConLNode* lcon = _lcons[l-_lcon_min];
742 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL)
743 return lcon;
744 }
745 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l));
746 assert(lcon->is_Con(), "");
747 if (l >= _lcon_min && l <= _lcon_max)
748 _lcons[l-_lcon_min] = lcon; // Cache small integers
749 return lcon;
750 }
751
752 //------------------------------zerocon-----------------------------------------
753 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))"
754 ConNode* PhaseTransform::zerocon(BasicType bt) {
755 assert((uint)bt <= _zcon_max, "domain check");
756 ConNode* zcon = _zcons[bt];
757 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL)
758 return zcon;
759 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt));
760 _zcons[bt] = zcon;
761 return zcon;
762 }
763
764
765
766 //=============================================================================
767 //------------------------------transform--------------------------------------
768 // Return a node which computes the same function as this node, but in a
769 // faster or cheaper fashion.
770 Node *PhaseGVN::transform( Node *n ) {
771 return transform_no_reclaim(n);
772 }
773
774 //------------------------------transform--------------------------------------
775 // Return a node which computes the same function as this node, but
776 // in a faster or cheaper fashion.
777 Node *PhaseGVN::transform_no_reclaim( Node *n ) {
778 NOT_PRODUCT( set_transforms(); )
779
780 // Apply the Ideal call in a loop until it no longer applies
781 Node *k = n;
782 NOT_PRODUCT( uint loop_count = 0; )
783 while( 1 ) {
784 Node *i = k->Ideal(this, /*can_reshape=*/false);
785 if( !i ) break;
786 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" );
787 k = i;
788 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform");
789 }
790 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } )
791
792
793 // If brand new node, make space in type array.
794 ensure_type_or_null(k);
795
796 // Since I just called 'Value' to compute the set of run-time values
797 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
798 // cache Value. Later requests for the local phase->type of this Node can
799 // use the cached Value instead of suffering with 'bottom_type'.
800 const Type *t = k->Value(this); // Get runtime Value set
801 assert(t != NULL, "value sanity");
802 if (type_or_null(k) != t) {
803 #ifndef PRODUCT
804 // Do not count initial visit to node as a transformation
805 if (type_or_null(k) == NULL) {
806 inc_new_values();
807 set_progress();
808 }
809 #endif
810 set_type(k, t);
811 // If k is a TypeNode, capture any more-precise type permanently into Node
812 k->raise_bottom_type(t);
813 }
814
815 if( t->singleton() && !k->is_Con() ) {
816 NOT_PRODUCT( set_progress(); )
817 return makecon(t); // Turn into a constant
818 }
819
820 // Now check for Identities
821 Node *i = k->Identity(this); // Look for a nearby replacement
822 if( i != k ) { // Found? Return replacement!
823 NOT_PRODUCT( set_progress(); )
824 return i;
825 }
826
827 // Global Value Numbering
828 i = hash_find_insert(k); // Insert if new
829 if( i && (i != k) ) {
830 // Return the pre-existing node
831 NOT_PRODUCT( set_progress(); )
832 return i;
833 }
834
835 // Return Idealized original
836 return k;
837 }
838
839 bool PhaseGVN::is_dominator_helper(Node *d, Node *n, bool linear_only) {
840 if (d->is_top() || n->is_top()) {
841 return false;
842 }
843 assert(d->is_CFG() && n->is_CFG(), "must have CFG nodes");
844 int i = 0;
845 while (d != n) {
846 n = IfNode::up_one_dom(n, linear_only);
847 i++;
848 if (n == NULL || i >= 10) {
849 return false;
850 }
851 }
852 return true;
853 }
854
855 #ifdef ASSERT
856 //------------------------------dead_loop_check--------------------------------
857 // Check for a simple dead loop when a data node references itself directly
858 // or through an other data node excluding cons and phis.
859 void PhaseGVN::dead_loop_check( Node *n ) {
860 // Phi may reference itself in a loop
861 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) {
862 // Do 2 levels check and only data inputs.
863 bool no_dead_loop = true;
864 uint cnt = n->req();
865 for (uint i = 1; i < cnt && no_dead_loop; i++) {
866 Node *in = n->in(i);
867 if (in == n) {
868 no_dead_loop = false;
869 } else if (in != NULL && !in->is_dead_loop_safe()) {
870 uint icnt = in->req();
871 for (uint j = 1; j < icnt && no_dead_loop; j++) {
872 if (in->in(j) == n || in->in(j) == in)
873 no_dead_loop = false;
874 }
875 }
876 }
877 if (!no_dead_loop) n->dump(3);
878 assert(no_dead_loop, "dead loop detected");
879 }
880 }
881 #endif
882
883 //=============================================================================
884 //------------------------------PhaseIterGVN-----------------------------------
885 // Initialize hash table to fresh and clean for +VerifyOpto
886 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ),
887 _stack(C->live_nodes() >> 1),
888 _delay_transform(false) {
889 }
890
891 //------------------------------PhaseIterGVN-----------------------------------
892 // Initialize with previous PhaseIterGVN info; used by PhaseCCP
893 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn),
894 _worklist( igvn->_worklist ),
895 _stack( igvn->_stack ),
896 _delay_transform(igvn->_delay_transform)
897 {
898 }
899
900 //------------------------------PhaseIterGVN-----------------------------------
901 // Initialize with previous PhaseGVN info from Parser
902 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn),
903 _worklist(*C->for_igvn()),
904 // TODO: Before incremental inlining it was allocated only once and it was fine. Now that
905 // the constructor is used in incremental inlining, this consumes too much memory:
906 // _stack(C->live_nodes() >> 1),
907 // So, as a band-aid, we replace this by:
908 _stack(C->comp_arena(), 32),
909 _delay_transform(false)
910 {
911 uint max;
912
913 // Dead nodes in the hash table inherited from GVN were not treated as
914 // roots during def-use info creation; hence they represent an invisible
915 // use. Clear them out.
916 max = _table.size();
917 for( uint i = 0; i < max; ++i ) {
918 Node *n = _table.at(i);
919 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) {
920 if( n->is_top() ) continue;
921 assert( false, "Parse::remove_useless_nodes missed this node");
922 hash_delete(n);
923 }
924 }
925
926 // Any Phis or Regions on the worklist probably had uses that could not
927 // make more progress because the uses were made while the Phis and Regions
928 // were in half-built states. Put all uses of Phis and Regions on worklist.
929 max = _worklist.size();
930 for( uint j = 0; j < max; j++ ) {
931 Node *n = _worklist.at(j);
932 uint uop = n->Opcode();
933 if( uop == Op_Phi || uop == Op_Region ||
934 n->is_Type() ||
935 n->is_Mem() )
936 add_users_to_worklist(n);
937 }
938 }
939
940 /**
941 * Initialize worklist for each node.
942 */
943 void PhaseIterGVN::init_worklist(Node* first) {
944 Unique_Node_List to_process;
945 to_process.push(first);
946
947 while (to_process.size() > 0) {
948 Node* n = to_process.pop();
949 if (!_worklist.member(n)) {
950 _worklist.push(n);
951
952 uint cnt = n->req();
953 for(uint i = 0; i < cnt; i++) {
954 Node* m = n->in(i);
955 if (m != NULL) {
956 to_process.push(m);
957 }
958 }
959 }
960 }
961 }
962
963 #ifndef PRODUCT
964 void PhaseIterGVN::verify_step(Node* n) {
965 if (VerifyIterativeGVN) {
966 _verify_window[_verify_counter % _verify_window_size] = n;
967 ++_verify_counter;
968 ResourceMark rm;
969 ResourceArea* area = Thread::current()->resource_area();
970 VectorSet old_space(area), new_space(area);
971 if (C->unique() < 1000 ||
972 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) {
973 ++_verify_full_passes;
974 Node::verify_recur(C->root(), -1, old_space, new_space);
975 }
976 const int verify_depth = 4;
977 for ( int i = 0; i < _verify_window_size; i++ ) {
978 Node* n = _verify_window[i];
979 if ( n == NULL ) continue;
980 if( n->in(0) == NodeSentinel ) { // xform_idom
981 _verify_window[i] = n->in(1);
982 --i; continue;
983 }
984 // Typical fanout is 1-2, so this call visits about 6 nodes.
985 Node::verify_recur(n, verify_depth, old_space, new_space);
986 }
987 }
988 }
989
990 void PhaseIterGVN::trace_PhaseIterGVN(Node* n, Node* nn, const Type* oldtype) {
991 if (TraceIterativeGVN) {
992 uint wlsize = _worklist.size();
993 const Type* newtype = type_or_null(n);
994 if (nn != n) {
995 // print old node
996 tty->print("< ");
997 if (oldtype != newtype && oldtype != NULL) {
998 oldtype->dump();
999 }
1000 do { tty->print("\t"); } while (tty->position() < 16);
1001 tty->print("<");
1002 n->dump();
1003 }
1004 if (oldtype != newtype || nn != n) {
1005 // print new node and/or new type
1006 if (oldtype == NULL) {
1007 tty->print("* ");
1008 } else if (nn != n) {
1009 tty->print("> ");
1010 } else {
1011 tty->print("= ");
1012 }
1013 if (newtype == NULL) {
1014 tty->print("null");
1015 } else {
1016 newtype->dump();
1017 }
1018 do { tty->print("\t"); } while (tty->position() < 16);
1019 nn->dump();
1020 }
1021 if (Verbose && wlsize < _worklist.size()) {
1022 tty->print(" Push {");
1023 while (wlsize != _worklist.size()) {
1024 Node* pushed = _worklist.at(wlsize++);
1025 tty->print(" %d", pushed->_idx);
1026 }
1027 tty->print_cr(" }");
1028 }
1029 if (nn != n) {
1030 // ignore n, it might be subsumed
1031 verify_step((Node*) NULL);
1032 }
1033 }
1034 }
1035
1036 void PhaseIterGVN::init_verifyPhaseIterGVN() {
1037 _verify_counter = 0;
1038 _verify_full_passes = 0;
1039 for (int i = 0; i < _verify_window_size; i++) {
1040 _verify_window[i] = NULL;
1041 }
1042 #ifdef ASSERT
1043 // Verify that all modified nodes are on _worklist
1044 Unique_Node_List* modified_list = C->modified_nodes();
1045 while (modified_list != NULL && modified_list->size()) {
1046 Node* n = modified_list->pop();
1047 if (n->outcnt() != 0 && !n->is_Con() && !_worklist.member(n)) {
1048 n->dump();
1049 assert(false, "modified node is not on IGVN._worklist");
1050 }
1051 }
1052 #endif
1053 }
1054
1055 void PhaseIterGVN::verify_PhaseIterGVN() {
1056 #ifdef ASSERT
1057 // Verify nodes with changed inputs.
1058 Unique_Node_List* modified_list = C->modified_nodes();
1059 while (modified_list != NULL && modified_list->size()) {
1060 Node* n = modified_list->pop();
1061 if (n->outcnt() != 0 && !n->is_Con()) { // skip dead and Con nodes
1062 n->dump();
1063 assert(false, "modified node was not processed by IGVN.transform_old()");
1064 }
1065 }
1066 #endif
1067
1068 C->verify_graph_edges();
1069 if( VerifyOpto && allow_progress() ) {
1070 // Must turn off allow_progress to enable assert and break recursion
1071 C->root()->verify();
1072 { // Check if any progress was missed using IterGVN
1073 // Def-Use info enables transformations not attempted in wash-pass
1074 // e.g. Region/Phi cleanup, ...
1075 // Null-check elision -- may not have reached fixpoint
1076 // do not propagate to dominated nodes
1077 ResourceMark rm;
1078 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean!
1079 // Fill worklist completely
1080 igvn2.init_worklist(C->root());
1081
1082 igvn2.set_allow_progress(false);
1083 igvn2.optimize();
1084 igvn2.set_allow_progress(true);
1085 }
1086 }
1087 if (VerifyIterativeGVN && PrintOpto) {
1088 if (_verify_counter == _verify_full_passes) {
1089 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes",
1090 (int) _verify_full_passes);
1091 } else {
1092 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes",
1093 (int) _verify_counter, (int) _verify_full_passes);
1094 }
1095 }
1096
1097 #ifdef ASSERT
1098 while (modified_list->size()) {
1099 Node* n = modified_list->pop();
1100 n->dump();
1101 assert(false, "VerifyIterativeGVN: new modified node was added");
1102 }
1103 #endif
1104 }
1105 #endif /* PRODUCT */
1106
1107 #ifdef ASSERT
1108 /**
1109 * Dumps information that can help to debug the problem. A debug
1110 * build fails with an assert.
1111 */
1112 void PhaseIterGVN::dump_infinite_loop_info(Node* n) {
1113 n->dump(4);
1114 _worklist.dump();
1115 assert(false, "infinite loop in PhaseIterGVN::optimize");
1116 }
1117
1118 /**
1119 * Prints out information about IGVN if the 'verbose' option is used.
1120 */
1121 void PhaseIterGVN::trace_PhaseIterGVN_verbose(Node* n, int num_processed) {
1122 if (TraceIterativeGVN && Verbose) {
1123 tty->print(" Pop ");
1124 n->dump();
1125 if ((num_processed % 100) == 0) {
1126 _worklist.print_set();
1127 }
1128 }
1129 }
1130 #endif /* ASSERT */
1131
1132 void PhaseIterGVN::optimize() {
1133 DEBUG_ONLY(uint num_processed = 0;)
1134 NOT_PRODUCT(init_verifyPhaseIterGVN();)
1135
1136 uint loop_count = 0;
1137 // Pull from worklist and transform the node. If the node has changed,
1138 // update edge info and put uses on worklist.
1139 while(_worklist.size()) {
1140 if (C->check_node_count(NodeLimitFudgeFactor * 2, "Out of nodes")) {
1141 return;
1142 }
1143 Node* n = _worklist.pop();
1144 if (++loop_count >= K * C->live_nodes()) {
1145 DEBUG_ONLY(dump_infinite_loop_info(n);)
1146 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize");
1147 return;
1148 }
1149 DEBUG_ONLY(trace_PhaseIterGVN_verbose(n, num_processed++);)
1150 if (n->outcnt() != 0) {
1151 NOT_PRODUCT(const Type* oldtype = type_or_null(n));
1152 // Do the transformation
1153 Node* nn = transform_old(n);
1154 NOT_PRODUCT(trace_PhaseIterGVN(n, nn, oldtype);)
1155 } else if (!n->is_top()) {
1156 remove_dead_node(n);
1157 }
1158 }
1159 NOT_PRODUCT(verify_PhaseIterGVN();)
1160 }
1161
1162
1163 /**
1164 * Register a new node with the optimizer. Update the types array, the def-use
1165 * info. Put on worklist.
1166 */
1167 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) {
1168 set_type_bottom(n);
1169 _worklist.push(n);
1170 if (orig != NULL) C->copy_node_notes_to(n, orig);
1171 return n;
1172 }
1173
1174 //------------------------------transform--------------------------------------
1175 // Non-recursive: idealize Node 'n' with respect to its inputs and its value
1176 Node *PhaseIterGVN::transform( Node *n ) {
1177 if (_delay_transform) {
1178 // Register the node but don't optimize for now
1179 register_new_node_with_optimizer(n);
1180 return n;
1181 }
1182
1183 // If brand new node, make space in type array, and give it a type.
1184 ensure_type_or_null(n);
1185 if (type_or_null(n) == NULL) {
1186 set_type_bottom(n);
1187 }
1188
1189 return transform_old(n);
1190 }
1191
1192 Node *PhaseIterGVN::transform_old(Node* n) {
1193 DEBUG_ONLY(uint loop_count = 0;);
1194 NOT_PRODUCT(set_transforms());
1195
1196 // Remove 'n' from hash table in case it gets modified
1197 _table.hash_delete(n);
1198 if (VerifyIterativeGVN) {
1199 assert(!_table.find_index(n->_idx), "found duplicate entry in table");
1200 }
1201
1202 // Apply the Ideal call in a loop until it no longer applies
1203 Node* k = n;
1204 DEBUG_ONLY(dead_loop_check(k);)
1205 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);)
1206 C->remove_modified_node(k);
1207 Node* i = k->Ideal(this, /*can_reshape=*/true);
1208 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1209 #ifndef PRODUCT
1210 verify_step(k);
1211 if (i && VerifyOpto ) {
1212 if (!allow_progress()) {
1213 if (i->is_Add() && (i->outcnt() == 1)) {
1214 // Switched input to left side because this is the only use
1215 } else if (i->is_If() && (i->in(0) == NULL)) {
1216 // This IF is dead because it is dominated by an equivalent IF When
1217 // dominating if changed, info is not propagated sparsely to 'this'
1218 // Propagating this info further will spuriously identify other
1219 // progress.
1220 return i;
1221 } else
1222 set_progress();
1223 } else {
1224 set_progress();
1225 }
1226 }
1227 #endif
1228
1229 while (i != NULL) {
1230 #ifdef ASSERT
1231 if (loop_count >= K) {
1232 dump_infinite_loop_info(i);
1233 }
1234 loop_count++;
1235 #endif
1236 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes");
1237 // Made a change; put users of original Node on worklist
1238 add_users_to_worklist(k);
1239 // Replacing root of transform tree?
1240 if (k != i) {
1241 // Make users of old Node now use new.
1242 subsume_node(k, i);
1243 k = i;
1244 }
1245 DEBUG_ONLY(dead_loop_check(k);)
1246 // Try idealizing again
1247 DEBUG_ONLY(is_new = (k->outcnt() == 0);)
1248 C->remove_modified_node(k);
1249 i = k->Ideal(this, /*can_reshape=*/true);
1250 assert(i != k || is_new || (i->outcnt() > 0), "don't return dead nodes");
1251 #ifndef PRODUCT
1252 verify_step(k);
1253 if (i && VerifyOpto) {
1254 set_progress();
1255 }
1256 #endif
1257 }
1258
1259 // If brand new node, make space in type array.
1260 ensure_type_or_null(k);
1261
1262 // See what kind of values 'k' takes on at runtime
1263 const Type* t = k->Value(this);
1264 assert(t != NULL, "value sanity");
1265
1266 // Since I just called 'Value' to compute the set of run-time values
1267 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
1268 // cache Value. Later requests for the local phase->type of this Node can
1269 // use the cached Value instead of suffering with 'bottom_type'.
1270 if (type_or_null(k) != t) {
1271 #ifndef PRODUCT
1272 inc_new_values();
1273 set_progress();
1274 #endif
1275 set_type(k, t);
1276 // If k is a TypeNode, capture any more-precise type permanently into Node
1277 k->raise_bottom_type(t);
1278 // Move users of node to worklist
1279 add_users_to_worklist(k);
1280 }
1281 // If 'k' computes a constant, replace it with a constant
1282 if (t->singleton() && !k->is_Con()) {
1283 NOT_PRODUCT(set_progress();)
1284 Node* con = makecon(t); // Make a constant
1285 add_users_to_worklist(k);
1286 subsume_node(k, con); // Everybody using k now uses con
1287 return con;
1288 }
1289
1290 // Now check for Identities
1291 i = k->Identity(this); // Look for a nearby replacement
1292 if (i != k) { // Found? Return replacement!
1293 NOT_PRODUCT(set_progress();)
1294 add_users_to_worklist(k);
1295 subsume_node(k, i); // Everybody using k now uses i
1296 return i;
1297 }
1298
1299 // Global Value Numbering
1300 i = hash_find_insert(k); // Check for pre-existing node
1301 if (i && (i != k)) {
1302 // Return the pre-existing node if it isn't dead
1303 NOT_PRODUCT(set_progress();)
1304 add_users_to_worklist(k);
1305 subsume_node(k, i); // Everybody using k now uses i
1306 return i;
1307 }
1308
1309 // Return Idealized original
1310 return k;
1311 }
1312
1313 //---------------------------------saturate------------------------------------
1314 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type,
1315 const Type* limit_type) const {
1316 return new_type->narrow(old_type);
1317 }
1318
1319 //------------------------------remove_globally_dead_node----------------------
1320 // Kill a globally dead Node. All uses are also globally dead and are
1321 // aggressively trimmed.
1322 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) {
1323 enum DeleteProgress {
1324 PROCESS_INPUTS,
1325 PROCESS_OUTPUTS
1326 };
1327 assert(_stack.is_empty(), "not empty");
1328 _stack.push(dead, PROCESS_INPUTS);
1329
1330 while (_stack.is_nonempty()) {
1331 dead = _stack.node();
1332 uint progress_state = _stack.index();
1333 assert(dead != C->root(), "killing root, eh?");
1334 assert(!dead->is_top(), "add check for top when pushing");
1335 NOT_PRODUCT( set_progress(); )
1336 if (progress_state == PROCESS_INPUTS) {
1337 // After following inputs, continue to outputs
1338 _stack.set_index(PROCESS_OUTPUTS);
1339 if (!dead->is_Con()) { // Don't kill cons but uses
1340 bool recurse = false;
1341 // Remove from hash table
1342 _table.hash_delete( dead );
1343 // Smash all inputs to 'dead', isolating him completely
1344 for (uint i = 0; i < dead->req(); i++) {
1345 Node *in = dead->in(i);
1346 if (in != NULL && in != C->top()) { // Points to something?
1347 int nrep = dead->replace_edge(in, NULL); // Kill edges
1348 assert((nrep > 0), "sanity");
1349 if (in->outcnt() == 0) { // Made input go dead?
1350 _stack.push(in, PROCESS_INPUTS); // Recursively remove
1351 recurse = true;
1352 } else if (in->outcnt() == 1 &&
1353 in->has_special_unique_user()) {
1354 _worklist.push(in->unique_out());
1355 } else if (in->outcnt() <= 2 && dead->is_Phi()) {
1356 if (in->Opcode() == Op_Region) {
1357 _worklist.push(in);
1358 } else if (in->is_Store()) {
1359 DUIterator_Fast imax, i = in->fast_outs(imax);
1360 _worklist.push(in->fast_out(i));
1361 i++;
1362 if (in->outcnt() == 2) {
1363 _worklist.push(in->fast_out(i));
1364 i++;
1365 }
1366 assert(!(i < imax), "sanity");
1367 }
1368 }
1369 if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory &&
1370 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) {
1371 // A Load that directly follows an InitializeNode is
1372 // going away. The Stores that follow are candidates
1373 // again to be captured by the InitializeNode.
1374 for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) {
1375 Node *n = in->fast_out(j);
1376 if (n->is_Store()) {
1377 _worklist.push(n);
1378 }
1379 }
1380 }
1381 } // if (in != NULL && in != C->top())
1382 } // for (uint i = 0; i < dead->req(); i++)
1383 if (recurse) {
1384 continue;
1385 }
1386 } // if (!dead->is_Con())
1387 } // if (progress_state == PROCESS_INPUTS)
1388
1389 // Aggressively kill globally dead uses
1390 // (Rather than pushing all the outs at once, we push one at a time,
1391 // plus the parent to resume later, because of the indefinite number
1392 // of edge deletions per loop trip.)
1393 if (dead->outcnt() > 0) {
1394 // Recursively remove output edges
1395 _stack.push(dead->raw_out(0), PROCESS_INPUTS);
1396 } else {
1397 // Finished disconnecting all input and output edges.
1398 _stack.pop();
1399 // Remove dead node from iterative worklist
1400 _worklist.remove(dead);
1401 C->remove_modified_node(dead);
1402 // Constant node that has no out-edges and has only one in-edge from
1403 // root is usually dead. However, sometimes reshaping walk makes
1404 // it reachable by adding use edges. So, we will NOT count Con nodes
1405 // as dead to be conservative about the dead node count at any
1406 // given time.
1407 if (!dead->is_Con()) {
1408 C->record_dead_node(dead->_idx);
1409 }
1410 if (dead->is_macro()) {
1411 C->remove_macro_node(dead);
1412 }
1413 if (dead->is_expensive()) {
1414 C->remove_expensive_node(dead);
1415 }
1416 CastIINode* cast = dead->isa_CastII();
1417 if (cast != NULL && cast->has_range_check()) {
1418 C->remove_range_check_cast(cast);
1419 }
1420 }
1421 } // while (_stack.is_nonempty())
1422 }
1423
1424 //------------------------------subsume_node-----------------------------------
1425 // Remove users from node 'old' and add them to node 'nn'.
1426 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
1427 assert( old != hash_find(old), "should already been removed" );
1428 assert( old != C->top(), "cannot subsume top node");
1429 // Copy debug or profile information to the new version:
1430 C->copy_node_notes_to(nn, old);
1431 // Move users of node 'old' to node 'nn'
1432 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) {
1433 Node* use = old->last_out(i); // for each use...
1434 // use might need re-hashing (but it won't if it's a new node)
1435 rehash_node_delayed(use);
1436 // Update use-def info as well
1437 // We remove all occurrences of old within use->in,
1438 // so as to avoid rehashing any node more than once.
1439 // The hash table probe swamps any outer loop overhead.
1440 uint num_edges = 0;
1441 for (uint jmax = use->len(), j = 0; j < jmax; j++) {
1442 if (use->in(j) == old) {
1443 use->set_req(j, nn);
1444 ++num_edges;
1445 }
1446 }
1447 i -= num_edges; // we deleted 1 or more copies of this edge
1448 }
1449
1450 // Smash all inputs to 'old', isolating him completely
1451 Node *temp = new Node(1);
1452 temp->init_req(0,nn); // Add a use to nn to prevent him from dying
1453 remove_dead_node( old );
1454 temp->del_req(0); // Yank bogus edge
1455 #ifndef PRODUCT
1456 if( VerifyIterativeGVN ) {
1457 for ( int i = 0; i < _verify_window_size; i++ ) {
1458 if ( _verify_window[i] == old )
1459 _verify_window[i] = nn;
1460 }
1461 }
1462 #endif
1463 _worklist.remove(temp); // this can be necessary
1464 temp->destruct(); // reuse the _idx of this little guy
1465 }
1466
1467 //------------------------------add_users_to_worklist--------------------------
1468 void PhaseIterGVN::add_users_to_worklist0( Node *n ) {
1469 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1470 _worklist.push(n->fast_out(i)); // Push on worklist
1471 }
1472 }
1473
1474 void PhaseIterGVN::add_users_to_worklist( Node *n ) {
1475 add_users_to_worklist0(n);
1476
1477 // Move users of node to worklist
1478 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1479 Node* use = n->fast_out(i); // Get use
1480
1481 if( use->is_Multi() || // Multi-definer? Push projs on worklist
1482 use->is_Store() ) // Enable store/load same address
1483 add_users_to_worklist0(use);
1484
1485 // If we changed the receiver type to a call, we need to revisit
1486 // the Catch following the call. It's looking for a non-NULL
1487 // receiver to know when to enable the regular fall-through path
1488 // in addition to the NullPtrException path.
1489 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) {
1490 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control);
1491 if (p != NULL) {
1492 add_users_to_worklist0(p);
1493 }
1494 }
1495
1496 uint use_op = use->Opcode();
1497 if(use->is_Cmp()) { // Enable CMP/BOOL optimization
1498 add_users_to_worklist(use); // Put Bool on worklist
1499 if (use->outcnt() > 0) {
1500 Node* bol = use->raw_out(0);
1501 if (bol->outcnt() > 0) {
1502 Node* iff = bol->raw_out(0);
1503 if (use_op == Op_CmpI &&
1504 iff->is_CountedLoopEnd()) {
1505 CountedLoopEndNode* cle = iff->as_CountedLoopEnd();
1506 if (cle->limit() == n && cle->phi() != NULL) {
1507 // If an opaque node feeds into the limit condition of a
1508 // CountedLoop, we need to process the Phi node for the
1509 // induction variable when the opaque node is removed:
1510 // the range of values taken by the Phi is now known and
1511 // so its type is also known.
1512 _worklist.push(cle->phi());
1513 }
1514 } else if (iff->outcnt() == 2) {
1515 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the
1516 // phi merging either 0 or 1 onto the worklist
1517 Node* ifproj0 = iff->raw_out(0);
1518 Node* ifproj1 = iff->raw_out(1);
1519 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) {
1520 Node* region0 = ifproj0->raw_out(0);
1521 Node* region1 = ifproj1->raw_out(0);
1522 if( region0 == region1 )
1523 add_users_to_worklist0(region0);
1524 }
1525 }
1526 }
1527 }
1528 if (use_op == Op_CmpI) {
1529 Node* in1 = use->in(1);
1530 for (uint i = 0; i < in1->outcnt(); i++) {
1531 if (in1->raw_out(i)->Opcode() == Op_CastII) {
1532 Node* castii = in1->raw_out(i);
1533 if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) {
1534 Node* ifnode = castii->in(0)->in(0);
1535 if (ifnode->in(1) != NULL && ifnode->in(1)->is_Bool() && ifnode->in(1)->in(1) == use) {
1536 // Reprocess a CastII node that may depend on an
1537 // opaque node value when the opaque node is
1538 // removed. In case it carries a dependency we can do
1539 // a better job of computing its type.
1540 _worklist.push(castii);
1541 }
1542 }
1543 }
1544 }
1545 }
1546 }
1547
1548 // If changed Cast input, check Phi users for simple cycles
1549 if (use->is_ConstraintCast()) {
1550 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1551 Node* u = use->fast_out(i2);
1552 if (u->is_Phi())
1553 _worklist.push(u);
1554 }
1555 }
1556 // If changed LShift inputs, check RShift users for useless sign-ext
1557 if( use_op == Op_LShiftI ) {
1558 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1559 Node* u = use->fast_out(i2);
1560 if (u->Opcode() == Op_RShiftI)
1561 _worklist.push(u);
1562 }
1563 }
1564 // If changed AddI/SubI inputs, check CmpU for range check optimization.
1565 if (use_op == Op_AddI || use_op == Op_SubI) {
1566 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1567 Node* u = use->fast_out(i2);
1568 if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) {
1569 _worklist.push(u);
1570 }
1571 }
1572 }
1573 // If changed AddP inputs, check Stores for loop invariant
1574 if( use_op == Op_AddP ) {
1575 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1576 Node* u = use->fast_out(i2);
1577 if (u->is_Mem())
1578 _worklist.push(u);
1579 }
1580 }
1581 // If changed initialization activity, check dependent Stores
1582 if (use_op == Op_Allocate || use_op == Op_AllocateArray) {
1583 InitializeNode* init = use->as_Allocate()->initialization();
1584 if (init != NULL) {
1585 Node* imem = init->proj_out(TypeFunc::Memory);
1586 if (imem != NULL) add_users_to_worklist0(imem);
1587 }
1588 }
1589 if (use_op == Op_Initialize) {
1590 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory);
1591 if (imem != NULL) add_users_to_worklist0(imem);
1592 }
1593 }
1594 }
1595
1596 /**
1597 * Remove the speculative part of all types that we know of
1598 */
1599 void PhaseIterGVN::remove_speculative_types() {
1600 assert(UseTypeSpeculation, "speculation is off");
1601 for (uint i = 0; i < _types.Size(); i++) {
1602 const Type* t = _types.fast_lookup(i);
1603 if (t != NULL) {
1604 _types.map(i, t->remove_speculative());
1605 }
1606 }
1607 _table.check_no_speculative_types();
1608 }
1609
1610 //=============================================================================
1611 #ifndef PRODUCT
1612 uint PhaseCCP::_total_invokes = 0;
1613 uint PhaseCCP::_total_constants = 0;
1614 #endif
1615 //------------------------------PhaseCCP---------------------------------------
1616 // Conditional Constant Propagation, ala Wegman & Zadeck
1617 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) {
1618 NOT_PRODUCT( clear_constants(); )
1619 assert( _worklist.size() == 0, "" );
1620 // Clear out _nodes from IterGVN. Must be clear to transform call.
1621 _nodes.clear(); // Clear out from IterGVN
1622 analyze();
1623 }
1624
1625 #ifndef PRODUCT
1626 //------------------------------~PhaseCCP--------------------------------------
1627 PhaseCCP::~PhaseCCP() {
1628 inc_invokes();
1629 _total_constants += count_constants();
1630 }
1631 #endif
1632
1633
1634 #ifdef ASSERT
1635 static bool ccp_type_widens(const Type* t, const Type* t0) {
1636 assert(t->meet(t0) == t, "Not monotonic");
1637 switch (t->base() == t0->base() ? t->base() : Type::Top) {
1638 case Type::Int:
1639 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases");
1640 break;
1641 case Type::Long:
1642 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases");
1643 break;
1644 }
1645 return true;
1646 }
1647 #endif //ASSERT
1648
1649 //------------------------------analyze----------------------------------------
1650 void PhaseCCP::analyze() {
1651 // Initialize all types to TOP, optimistic analysis
1652 for (int i = C->unique() - 1; i >= 0; i--) {
1653 _types.map(i,Type::TOP);
1654 }
1655
1656 // Push root onto worklist
1657 Unique_Node_List worklist;
1658 worklist.push(C->root());
1659
1660 // Pull from worklist; compute new value; push changes out.
1661 // This loop is the meat of CCP.
1662 while( worklist.size() ) {
1663 Node *n = worklist.pop();
1664 const Type *t = n->Value(this);
1665 if (t != type(n)) {
1666 assert(ccp_type_widens(t, type(n)), "ccp type must widen");
1667 #ifndef PRODUCT
1668 if( TracePhaseCCP ) {
1669 t->dump();
1670 do { tty->print("\t"); } while (tty->position() < 16);
1671 n->dump();
1672 }
1673 #endif
1674 set_type(n, t);
1675 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1676 Node* m = n->fast_out(i); // Get user
1677 if (m->is_Region()) { // New path to Region? Must recheck Phis too
1678 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1679 Node* p = m->fast_out(i2); // Propagate changes to uses
1680 if (p->bottom_type() != type(p)) { // If not already bottomed out
1681 worklist.push(p); // Propagate change to user
1682 }
1683 }
1684 }
1685 // If we changed the receiver type to a call, we need to revisit
1686 // the Catch following the call. It's looking for a non-NULL
1687 // receiver to know when to enable the regular fall-through path
1688 // in addition to the NullPtrException path
1689 if (m->is_Call()) {
1690 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1691 Node* p = m->fast_out(i2); // Propagate changes to uses
1692 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) {
1693 worklist.push(p->unique_out());
1694 }
1695 }
1696 }
1697 if (m->bottom_type() != type(m)) { // If not already bottomed out
1698 worklist.push(m); // Propagate change to user
1699 }
1700
1701 // CmpU nodes can get their type information from two nodes up in the
1702 // graph (instead of from the nodes immediately above). Make sure they
1703 // are added to the worklist if nodes they depend on are updated, since
1704 // they could be missed and get wrong types otherwise.
1705 uint m_op = m->Opcode();
1706 if (m_op == Op_AddI || m_op == Op_SubI) {
1707 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1708 Node* p = m->fast_out(i2); // Propagate changes to uses
1709 if (p->Opcode() == Op_CmpU) {
1710 // Got a CmpU which might need the new type information from node n.
1711 if(p->bottom_type() != type(p)) { // If not already bottomed out
1712 worklist.push(p); // Propagate change to user
1713 }
1714 }
1715 }
1716 }
1717 }
1718 }
1719 }
1720 }
1721
1722 //------------------------------do_transform-----------------------------------
1723 // Top level driver for the recursive transformer
1724 void PhaseCCP::do_transform() {
1725 // Correct leaves of new-space Nodes; they point to old-space.
1726 C->set_root( transform(C->root())->as_Root() );
1727 assert( C->top(), "missing TOP node" );
1728 assert( C->root(), "missing root" );
1729 }
1730
1731 //------------------------------transform--------------------------------------
1732 // Given a Node in old-space, clone him into new-space.
1733 // Convert any of his old-space children into new-space children.
1734 Node *PhaseCCP::transform( Node *n ) {
1735 Node *new_node = _nodes[n->_idx]; // Check for transformed node
1736 if( new_node != NULL )
1737 return new_node; // Been there, done that, return old answer
1738 new_node = transform_once(n); // Check for constant
1739 _nodes.map( n->_idx, new_node ); // Flag as having been cloned
1740
1741 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc
1742 GrowableArray <Node *> trstack(C->live_nodes() >> 1);
1743
1744 trstack.push(new_node); // Process children of cloned node
1745 while ( trstack.is_nonempty() ) {
1746 Node *clone = trstack.pop();
1747 uint cnt = clone->req();
1748 for( uint i = 0; i < cnt; i++ ) { // For all inputs do
1749 Node *input = clone->in(i);
1750 if( input != NULL ) { // Ignore NULLs
1751 Node *new_input = _nodes[input->_idx]; // Check for cloned input node
1752 if( new_input == NULL ) {
1753 new_input = transform_once(input); // Check for constant
1754 _nodes.map( input->_idx, new_input );// Flag as having been cloned
1755 trstack.push(new_input);
1756 }
1757 assert( new_input == clone->in(i), "insanity check");
1758 }
1759 }
1760 }
1761 return new_node;
1762 }
1763
1764
1765 //------------------------------transform_once---------------------------------
1766 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant.
1767 Node *PhaseCCP::transform_once( Node *n ) {
1768 const Type *t = type(n);
1769 // Constant? Use constant Node instead
1770 if( t->singleton() ) {
1771 Node *nn = n; // Default is to return the original constant
1772 if( t == Type::TOP ) {
1773 // cache my top node on the Compile instance
1774 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) {
1775 C->set_cached_top_node(ConNode::make(Type::TOP));
1776 set_type(C->top(), Type::TOP);
1777 }
1778 nn = C->top();
1779 }
1780 if( !n->is_Con() ) {
1781 if( t != Type::TOP ) {
1782 nn = makecon(t); // ConNode::make(t);
1783 NOT_PRODUCT( inc_constants(); )
1784 } else if( n->is_Region() ) { // Unreachable region
1785 // Note: nn == C->top()
1786 n->set_req(0, NULL); // Cut selfreference
1787 // Eagerly remove dead phis to avoid phis copies creation.
1788 for (DUIterator i = n->outs(); n->has_out(i); i++) {
1789 Node* m = n->out(i);
1790 if( m->is_Phi() ) {
1791 assert(type(m) == Type::TOP, "Unreachable region should not have live phis.");
1792 replace_node(m, nn);
1793 --i; // deleted this phi; rescan starting with next position
1794 }
1795 }
1796 }
1797 replace_node(n,nn); // Update DefUse edges for new constant
1798 }
1799 return nn;
1800 }
1801
1802 // If x is a TypeNode, capture any more-precise type permanently into Node
1803 if (t != n->bottom_type()) {
1804 hash_delete(n); // changing bottom type may force a rehash
1805 n->raise_bottom_type(t);
1806 _worklist.push(n); // n re-enters the hash table via the worklist
1807 }
1808
1809 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks
1810 switch( n->Opcode() ) {
1811 case Op_FastLock: // Revisit FastLocks for lock coarsening
1812 case Op_If:
1813 case Op_CountedLoopEnd:
1814 case Op_Region:
1815 case Op_Loop:
1816 case Op_CountedLoop:
1817 case Op_Conv2B:
1818 case Op_Opaque1:
1819 case Op_Opaque2:
1820 _worklist.push(n);
1821 break;
1822 default:
1823 break;
1824 }
1825
1826 return n;
1827 }
1828
1829 //---------------------------------saturate------------------------------------
1830 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type,
1831 const Type* limit_type) const {
1832 const Type* wide_type = new_type->widen(old_type, limit_type);
1833 if (wide_type != new_type) { // did we widen?
1834 // If so, we may have widened beyond the limit type. Clip it back down.
1835 new_type = wide_type->filter(limit_type);
1836 }
1837 return new_type;
1838 }
1839
1840 //------------------------------print_statistics-------------------------------
1841 #ifndef PRODUCT
1842 void PhaseCCP::print_statistics() {
1843 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants);
1844 }
1845 #endif
1846
1847
1848 //=============================================================================
1849 #ifndef PRODUCT
1850 uint PhasePeephole::_total_peepholes = 0;
1851 #endif
1852 //------------------------------PhasePeephole----------------------------------
1853 // Conditional Constant Propagation, ala Wegman & Zadeck
1854 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg )
1855 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) {
1856 NOT_PRODUCT( clear_peepholes(); )
1857 }
1858
1859 #ifndef PRODUCT
1860 //------------------------------~PhasePeephole---------------------------------
1861 PhasePeephole::~PhasePeephole() {
1862 _total_peepholes += count_peepholes();
1863 }
1864 #endif
1865
1866 //------------------------------transform--------------------------------------
1867 Node *PhasePeephole::transform( Node *n ) {
1868 ShouldNotCallThis();
1869 return NULL;
1870 }
1871
1872 //------------------------------do_transform-----------------------------------
1873 void PhasePeephole::do_transform() {
1874 bool method_name_not_printed = true;
1875
1876 // Examine each basic block
1877 for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) {
1878 Block* block = _cfg.get_block(block_number);
1879 bool block_not_printed = true;
1880
1881 // and each instruction within a block
1882 uint end_index = block->number_of_nodes();
1883 // block->end_idx() not valid after PhaseRegAlloc
1884 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) {
1885 Node *n = block->get_node(instruction_index);
1886 if( n->is_Mach() ) {
1887 MachNode *m = n->as_Mach();
1888 int deleted_count = 0;
1889 // check for peephole opportunities
1890 MachNode *m2 = m->peephole(block, instruction_index, _regalloc, deleted_count);
1891 if( m2 != NULL ) {
1892 #ifndef PRODUCT
1893 if( PrintOptoPeephole ) {
1894 // Print method, first time only
1895 if( C->method() && method_name_not_printed ) {
1896 C->method()->print_short_name(); tty->cr();
1897 method_name_not_printed = false;
1898 }
1899 // Print this block
1900 if( Verbose && block_not_printed) {
1901 tty->print_cr("in block");
1902 block->dump();
1903 block_not_printed = false;
1904 }
1905 // Print instructions being deleted
1906 for( int i = (deleted_count - 1); i >= 0; --i ) {
1907 block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr();
1908 }
1909 tty->print_cr("replaced with");
1910 // Print new instruction
1911 m2->format(_regalloc);
1912 tty->print("\n\n");
1913 }
1914 #endif
1915 // Remove old nodes from basic block and update instruction_index
1916 // (old nodes still exist and may have edges pointing to them
1917 // as register allocation info is stored in the allocator using
1918 // the node index to live range mappings.)
1919 uint safe_instruction_index = (instruction_index - deleted_count);
1920 for( ; (instruction_index > safe_instruction_index); --instruction_index ) {
1921 block->remove_node( instruction_index );
1922 }
1923 // install new node after safe_instruction_index
1924 block->insert_node(m2, safe_instruction_index + 1);
1925 end_index = block->number_of_nodes() - 1; // Recompute new block size
1926 NOT_PRODUCT( inc_peepholes(); )
1927 }
1928 }
1929 }
1930 }
1931 }
1932
1933 //------------------------------print_statistics-------------------------------
1934 #ifndef PRODUCT
1935 void PhasePeephole::print_statistics() {
1936 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes);
1937 }
1938 #endif
1939
1940
1941 //=============================================================================
1942 //------------------------------set_req_X--------------------------------------
1943 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1944 assert( is_not_dead(n), "can not use dead node");
1945 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1946 Node *old = in(i);
1947 set_req(i, n);
1948
1949 // old goes dead?
1950 if( old ) {
1951 switch (old->outcnt()) {
1952 case 0:
1953 // Put into the worklist to kill later. We do not kill it now because the
1954 // recursive kill will delete the current node (this) if dead-loop exists
1955 if (!old->is_top())
1956 igvn->_worklist.push( old );
1957 break;
1958 case 1:
1959 if( old->is_Store() || old->has_special_unique_user() )
1960 igvn->add_users_to_worklist( old );
1961 break;
1962 case 2:
1963 if( old->is_Store() )
1964 igvn->add_users_to_worklist( old );
1965 if( old->Opcode() == Op_Region )
1966 igvn->_worklist.push(old);
1967 break;
1968 case 3:
1969 if( old->Opcode() == Op_Region ) {
1970 igvn->_worklist.push(old);
1971 igvn->add_users_to_worklist( old );
1972 }
1973 break;
1974 default:
1975 break;
1976 }
1977 }
1978
1979 }
1980
1981 //-------------------------------replace_by-----------------------------------
1982 // Using def-use info, replace one node for another. Follow the def-use info
1983 // to all users of the OLD node. Then make all uses point to the NEW node.
1984 void Node::replace_by(Node *new_node) {
1985 assert(!is_top(), "top node has no DU info");
1986 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) {
1987 Node* use = last_out(i);
1988 uint uses_found = 0;
1989 for (uint j = 0; j < use->len(); j++) {
1990 if (use->in(j) == this) {
1991 if (j < use->req())
1992 use->set_req(j, new_node);
1993 else use->set_prec(j, new_node);
1994 uses_found++;
1995 }
1996 }
1997 i -= uses_found; // we deleted 1 or more copies of this edge
1998 }
1999 }
2000
2001 //=============================================================================
2002 //-----------------------------------------------------------------------------
2003 void Type_Array::grow( uint i ) {
2004 if( !_max ) {
2005 _max = 1;
2006 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) );
2007 _types[0] = NULL;
2008 }
2009 uint old = _max;
2010 while( i >= _max ) _max <<= 1; // Double to fit
2011 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*));
2012 memset( &_types[old], 0, (_max-old)*sizeof(Type*) );
2013 }
2014
2015 //------------------------------dump-------------------------------------------
2016 #ifndef PRODUCT
2017 void Type_Array::dump() const {
2018 uint max = Size();
2019 for( uint i = 0; i < max; i++ ) {
2020 if( _types[i] != NULL ) {
2021 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr();
2022 }
2023 }
2024 }
2025 #endif