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 #include "opto/shenandoahSupport.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 ) : Phase(Remove_Useless),
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 //=============================================================================
449 //------------------------------PhaseTransform---------------------------------
450 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum),
451 _arena(Thread::current()->resource_area()),
452 _nodes(_arena),
453 _types(_arena)
454 {
455 init_con_caches();
456 #ifndef PRODUCT
457 clear_progress();
458 clear_transforms();
459 set_allow_progress(true);
460 #endif
461 // Force allocation for currently existing nodes
462 _types.map(C->unique(), NULL);
463 }
464
465 //------------------------------PhaseTransform---------------------------------
466 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum),
467 _arena(arena),
468 _nodes(arena),
469 _types(arena)
470 {
471 init_con_caches();
472 #ifndef PRODUCT
473 clear_progress();
474 clear_transforms();
475 set_allow_progress(true);
476 #endif
477 // Force allocation for currently existing nodes
478 _types.map(C->unique(), NULL);
479 }
480
481 //------------------------------PhaseTransform---------------------------------
482 // Initialize with previously generated type information
483 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum),
484 _arena(pt->_arena),
485 _nodes(pt->_nodes),
486 _types(pt->_types)
487 {
488 init_con_caches();
489 #ifndef PRODUCT
490 clear_progress();
491 clear_transforms();
492 set_allow_progress(true);
493 #endif
494 }
495
496 void PhaseTransform::init_con_caches() {
497 memset(_icons,0,sizeof(_icons));
498 memset(_lcons,0,sizeof(_lcons));
499 memset(_zcons,0,sizeof(_zcons));
500 }
501
502
503 //--------------------------------find_int_type--------------------------------
504 const TypeInt* PhaseTransform::find_int_type(Node* n) {
505 if (n == NULL) return NULL;
506 // Call type_or_null(n) to determine node's type since we might be in
507 // parse phase and call n->Value() may return wrong type.
508 // (For example, a phi node at the beginning of loop parsing is not ready.)
509 const Type* t = type_or_null(n);
510 if (t == NULL) return NULL;
511 return t->isa_int();
512 }
513
514
515 //-------------------------------find_long_type--------------------------------
516 const TypeLong* PhaseTransform::find_long_type(Node* n) {
517 if (n == NULL) return NULL;
518 // (See comment above on type_or_null.)
519 const Type* t = type_or_null(n);
520 if (t == NULL) return NULL;
521 return t->isa_long();
522 }
523
524
525 #ifndef PRODUCT
526 void PhaseTransform::dump_old2new_map() const {
527 _nodes.dump();
528 }
529
530 void PhaseTransform::dump_new( uint nidx ) const {
531 for( uint i=0; i<_nodes.Size(); i++ )
532 if( _nodes[i] && _nodes[i]->_idx == nidx ) {
533 _nodes[i]->dump();
534 tty->cr();
535 tty->print_cr("Old index= %d",i);
536 return;
537 }
538 tty->print_cr("Node %d not found in the new indices", nidx);
539 }
540
541 //------------------------------dump_types-------------------------------------
542 void PhaseTransform::dump_types( ) const {
543 _types.dump();
544 }
545
546 //------------------------------dump_nodes_and_types---------------------------
547 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) {
548 VectorSet visited(Thread::current()->resource_area());
549 dump_nodes_and_types_recur( root, depth, only_ctrl, visited );
550 }
551
552 //------------------------------dump_nodes_and_types_recur---------------------
553 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) {
554 if( !n ) return;
555 if( depth == 0 ) return;
556 if( visited.test_set(n->_idx) ) return;
557 for( uint i=0; i<n->len(); i++ ) {
558 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue;
559 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited );
560 }
561 n->dump();
562 if (type_or_null(n) != NULL) {
563 tty->print(" "); type(n)->dump(); tty->cr();
564 }
565 }
566
567 #endif
568
569 bool PhaseTransform::eqv(const Node* n1, const Node* n2) const {
570 if (UseShenandoahGC) {
571
572 if (n1 == n2) return true;
573
574 if (n1 == NULL || n2 == NULL) return false;
575
576 if (n1->is_AddP() && n2->is_AddP()) {
577 Node* addp1 = n1->as_AddP();
578 Node* base1 = addp1->in(AddPNode::Base);
579 Node* addr1 = addp1->in(AddPNode::Address);
580 Node* offs1 = addp1->in(AddPNode::Offset);
581
582 Node* addp2 = n2->as_AddP();
583 Node* base2 = addp2->in(AddPNode::Base);
584 Node* addr2 = addp2->in(AddPNode::Address);
585 Node* offs2 = addp2->in(AddPNode::Offset);
586
587 if (base1 == addr1 && base2 == addr2) {
588
589 addr1 = ShenandoahBarrierNode::skip_through_barrier(addr1);
590 addr2 = ShenandoahBarrierNode::skip_through_barrier(addr2);
591
592 if (addr1 == addr2 && offs1 == offs2) return true;
593 }
594
595 }
596 return false;
597 } else {
598 return n1 == n2;
599 }
600 }
601
602 //=============================================================================
603 //------------------------------PhaseValues------------------------------------
604 // Set minimum table size to "255"
605 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) {
606 NOT_PRODUCT( clear_new_values(); )
607 }
608
609 //------------------------------PhaseValues------------------------------------
610 // Set minimum table size to "255"
611 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ),
612 _table(&ptv->_table) {
613 NOT_PRODUCT( clear_new_values(); )
614 }
615
616 //------------------------------PhaseValues------------------------------------
617 // Used by +VerifyOpto. Clear out hash table but copy _types array.
618 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ),
619 _table(ptv->arena(),ptv->_table.size()) {
620 NOT_PRODUCT( clear_new_values(); )
621 }
622
623 //------------------------------~PhaseValues-----------------------------------
624 #ifndef PRODUCT
625 PhaseValues::~PhaseValues() {
626 _table.dump();
627
628 // Statistics for value progress and efficiency
629 if( PrintCompilation && Verbose && WizardMode ) {
630 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)",
631 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values());
632 if( made_transforms() != 0 ) {
633 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() );
634 } else {
635 tty->cr();
636 }
637 }
638 }
639 #endif
640
641 //------------------------------makecon----------------------------------------
642 ConNode* PhaseTransform::makecon(const Type *t) {
643 assert(t->singleton(), "must be a constant");
644 assert(!t->empty() || t == Type::TOP, "must not be vacuous range");
645 switch (t->base()) { // fast paths
646 case Type::Half:
647 case Type::Top: return (ConNode*) C->top();
648 case Type::Int: return intcon( t->is_int()->get_con() );
649 case Type::Long: return longcon( t->is_long()->get_con() );
650 }
651 if (t->is_zero_type())
652 return zerocon(t->basic_type());
653 return uncached_makecon(t);
654 }
655
656 //--------------------------uncached_makecon-----------------------------------
657 // Make an idealized constant - one of ConINode, ConPNode, etc.
658 ConNode* PhaseValues::uncached_makecon(const Type *t) {
659 assert(t->singleton(), "must be a constant");
660 ConNode* x = ConNode::make(t);
661 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering
662 if (k == NULL) {
663 set_type(x, t); // Missed, provide type mapping
664 GrowableArray<Node_Notes*>* nna = C->node_note_array();
665 if (nna != NULL) {
666 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true);
667 loc->clear(); // do not put debug info on constants
668 }
669 } else {
670 x->destruct(); // Hit, destroy duplicate constant
671 x = k; // use existing constant
672 }
673 return x;
674 }
675
676 //------------------------------intcon-----------------------------------------
677 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))"
678 ConINode* PhaseTransform::intcon(int i) {
679 // Small integer? Check cache! Check that cached node is not dead
680 if (i >= _icon_min && i <= _icon_max) {
681 ConINode* icon = _icons[i-_icon_min];
682 if (icon != NULL && icon->in(TypeFunc::Control) != NULL)
683 return icon;
684 }
685 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i));
686 assert(icon->is_Con(), "");
687 if (i >= _icon_min && i <= _icon_max)
688 _icons[i-_icon_min] = icon; // Cache small integers
689 return icon;
690 }
691
692 //------------------------------longcon----------------------------------------
693 // Fast long constant.
694 ConLNode* PhaseTransform::longcon(jlong l) {
695 // Small integer? Check cache! Check that cached node is not dead
696 if (l >= _lcon_min && l <= _lcon_max) {
697 ConLNode* lcon = _lcons[l-_lcon_min];
698 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL)
699 return lcon;
700 }
701 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l));
702 assert(lcon->is_Con(), "");
703 if (l >= _lcon_min && l <= _lcon_max)
704 _lcons[l-_lcon_min] = lcon; // Cache small integers
705 return lcon;
706 }
707
708 //------------------------------zerocon-----------------------------------------
709 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))"
710 ConNode* PhaseTransform::zerocon(BasicType bt) {
711 assert((uint)bt <= _zcon_max, "domain check");
712 ConNode* zcon = _zcons[bt];
713 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL)
714 return zcon;
715 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt));
716 _zcons[bt] = zcon;
717 return zcon;
718 }
719
720
721
722 //=============================================================================
723 //------------------------------transform--------------------------------------
724 // Return a node which computes the same function as this node, but in a
725 // faster or cheaper fashion.
726 Node *PhaseGVN::transform( Node *n ) {
727 return transform_no_reclaim(n);
728 }
729
730 //------------------------------transform--------------------------------------
731 // Return a node which computes the same function as this node, but
732 // in a faster or cheaper fashion.
733 Node *PhaseGVN::transform_no_reclaim( Node *n ) {
734 NOT_PRODUCT( set_transforms(); )
735
736 // Apply the Ideal call in a loop until it no longer applies
737 Node *k = n;
738 NOT_PRODUCT( uint loop_count = 0; )
739 while( 1 ) {
740 Node *i = k->Ideal(this, /*can_reshape=*/false);
741 if( !i ) break;
742 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" );
743 k = i;
744 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform");
745 }
746 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } )
747
748
749 // If brand new node, make space in type array.
750 ensure_type_or_null(k);
751
752 // Since I just called 'Value' to compute the set of run-time values
753 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
754 // cache Value. Later requests for the local phase->type of this Node can
755 // use the cached Value instead of suffering with 'bottom_type'.
756 const Type *t = k->Value(this); // Get runtime Value set
757 assert(t != NULL, "value sanity");
758 if (type_or_null(k) != t) {
759 #ifndef PRODUCT
760 // Do not count initial visit to node as a transformation
761 if (type_or_null(k) == NULL) {
762 inc_new_values();
763 set_progress();
764 }
765 #endif
766 set_type(k, t);
767 // If k is a TypeNode, capture any more-precise type permanently into Node
768 k->raise_bottom_type(t);
769 }
770
771 if( t->singleton() && !k->is_Con() ) {
772 NOT_PRODUCT( set_progress(); )
773 return makecon(t); // Turn into a constant
774 }
775
776 // Now check for Identities
777 Node *i = k->Identity(this); // Look for a nearby replacement
778 if( i != k ) { // Found? Return replacement!
779 NOT_PRODUCT( set_progress(); )
780 return i;
781 }
782
783 // Global Value Numbering
784 i = hash_find_insert(k); // Insert if new
785 if( i && (i != k) ) {
786 // Return the pre-existing node
787 NOT_PRODUCT( set_progress(); )
788 return i;
789 }
790
791 // Return Idealized original
792 return k;
793 }
794
795 #ifdef ASSERT
796 //------------------------------dead_loop_check--------------------------------
797 // Check for a simple dead loop when a data node references itself directly
798 // or through an other data node excluding cons and phis.
799 void PhaseGVN::dead_loop_check( Node *n ) {
800 // Phi may reference itself in a loop
801 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) {
802 // Do 2 levels check and only data inputs.
803 bool no_dead_loop = true;
804 uint cnt = n->req();
805 for (uint i = 1; i < cnt && no_dead_loop; i++) {
806 Node *in = n->in(i);
807 if (in == n) {
808 no_dead_loop = false;
809 } else if (in != NULL && !in->is_dead_loop_safe()) {
810 uint icnt = in->req();
811 for (uint j = 1; j < icnt && no_dead_loop; j++) {
812 if (in->in(j) == n || in->in(j) == in)
813 no_dead_loop = false;
814 }
815 }
816 }
817 if (!no_dead_loop) n->dump(3);
818 assert(no_dead_loop, "dead loop detected");
819 }
820 }
821 #endif
822
823 //=============================================================================
824 //------------------------------PhaseIterGVN-----------------------------------
825 // Initialize hash table to fresh and clean for +VerifyOpto
826 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ),
827 _stack(C->live_nodes() >> 1),
828 _delay_transform(false) {
829 }
830
831 //------------------------------PhaseIterGVN-----------------------------------
832 // Initialize with previous PhaseIterGVN info; used by PhaseCCP
833 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn),
834 _worklist( igvn->_worklist ),
835 _stack( igvn->_stack ),
836 _delay_transform(igvn->_delay_transform)
837 {
838 }
839
840 //------------------------------PhaseIterGVN-----------------------------------
841 // Initialize with previous PhaseGVN info from Parser
842 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn),
843 _worklist(*C->for_igvn()),
844 // TODO: Before incremental inlining it was allocated only once and it was fine. Now that
845 // the constructor is used in incremental inlining, this consumes too much memory:
846 // _stack(C->live_nodes() >> 1),
847 // So, as a band-aid, we replace this by:
848 _stack(C->comp_arena(), 32),
849 _delay_transform(false)
850 {
851 uint max;
852
853 // Dead nodes in the hash table inherited from GVN were not treated as
854 // roots during def-use info creation; hence they represent an invisible
855 // use. Clear them out.
856 max = _table.size();
857 for( uint i = 0; i < max; ++i ) {
858 Node *n = _table.at(i);
859 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) {
860 if( n->is_top() ) continue;
861 assert( false, "Parse::remove_useless_nodes missed this node");
862 hash_delete(n);
863 }
864 }
865
866 // Any Phis or Regions on the worklist probably had uses that could not
867 // make more progress because the uses were made while the Phis and Regions
868 // were in half-built states. Put all uses of Phis and Regions on worklist.
869 max = _worklist.size();
870 for( uint j = 0; j < max; j++ ) {
871 Node *n = _worklist.at(j);
872 uint uop = n->Opcode();
873 if( uop == Op_Phi || uop == Op_Region ||
874 n->is_Type() ||
875 n->is_Mem() )
876 add_users_to_worklist(n);
877 }
878 }
879
880 /**
881 * Initialize worklist for each node.
882 */
883 void PhaseIterGVN::init_worklist(Node* first) {
884 Unique_Node_List to_process;
885 to_process.push(first);
886
887 while (to_process.size() > 0) {
888 Node* n = to_process.pop();
889 if (!_worklist.member(n)) {
890 _worklist.push(n);
891
892 uint cnt = n->req();
893 for(uint i = 0; i < cnt; i++) {
894 Node* m = n->in(i);
895 if (m != NULL) {
896 to_process.push(m);
897 }
898 }
899 }
900 }
901 }
902
903 #ifndef PRODUCT
904 void PhaseIterGVN::verify_step(Node* n) {
905 if (VerifyIterativeGVN) {
906 _verify_window[_verify_counter % _verify_window_size] = n;
907 ++_verify_counter;
908 ResourceMark rm;
909 ResourceArea* area = Thread::current()->resource_area();
910 VectorSet old_space(area), new_space(area);
911 if (C->unique() < 1000 ||
912 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) {
913 ++_verify_full_passes;
914 Node::verify_recur(C->root(), -1, old_space, new_space);
915 }
916 const int verify_depth = 4;
917 for ( int i = 0; i < _verify_window_size; i++ ) {
918 Node* n = _verify_window[i];
919 if ( n == NULL ) continue;
920 if( n->in(0) == NodeSentinel ) { // xform_idom
921 _verify_window[i] = n->in(1);
922 --i; continue;
923 }
924 // Typical fanout is 1-2, so this call visits about 6 nodes.
925 Node::verify_recur(n, verify_depth, old_space, new_space);
926 }
927 }
928 }
929
930 void PhaseIterGVN::trace_PhaseIterGVN(Node* n, Node* nn, const Type* oldtype) {
931 if (TraceIterativeGVN) {
932 uint wlsize = _worklist.size();
933 const Type* newtype = type_or_null(n);
934 if (nn != n) {
935 // print old node
936 tty->print("< ");
937 if (oldtype != newtype && oldtype != NULL) {
938 oldtype->dump();
939 }
940 do { tty->print("\t"); } while (tty->position() < 16);
941 tty->print("<");
942 n->dump();
943 }
944 if (oldtype != newtype || nn != n) {
945 // print new node and/or new type
946 if (oldtype == NULL) {
947 tty->print("* ");
948 } else if (nn != n) {
949 tty->print("> ");
950 } else {
951 tty->print("= ");
952 }
953 if (newtype == NULL) {
954 tty->print("null");
955 } else {
956 newtype->dump();
957 }
958 do { tty->print("\t"); } while (tty->position() < 16);
959 nn->dump();
960 }
961 if (Verbose && wlsize < _worklist.size()) {
962 tty->print(" Push {");
963 while (wlsize != _worklist.size()) {
964 Node* pushed = _worklist.at(wlsize++);
965 tty->print(" %d", pushed->_idx);
966 }
967 tty->print_cr(" }");
968 }
969 if (nn != n) {
970 // ignore n, it might be subsumed
971 verify_step((Node*) NULL);
972 }
973 }
974 }
975
976 void PhaseIterGVN::init_verifyPhaseIterGVN() {
977 _verify_counter = 0;
978 _verify_full_passes = 0;
979 for (int i = 0; i < _verify_window_size; i++) {
980 _verify_window[i] = NULL;
981 }
982 #ifdef ASSERT
983 // Verify that all modified nodes are on _worklist
984 Unique_Node_List* modified_list = C->modified_nodes();
985 while (modified_list != NULL && modified_list->size()) {
986 Node* n = modified_list->pop();
987 if (n->outcnt() != 0 && !n->is_Con() && !_worklist.member(n)) {
988 n->dump();
989 assert(false, "modified node is not on IGVN._worklist");
990 }
991 }
992 #endif
993 }
994
995 void PhaseIterGVN::verify_PhaseIterGVN() {
996 #ifdef ASSERT
997 // Verify nodes with changed inputs.
998 Unique_Node_List* modified_list = C->modified_nodes();
999 while (modified_list != NULL && modified_list->size()) {
1000 Node* n = modified_list->pop();
1001 if (n->outcnt() != 0 && !n->is_Con()) { // skip dead and Con nodes
1002 n->dump();
1003 assert(false, "modified node was not processed by IGVN.transform_old()");
1004 }
1005 }
1006 #endif
1007
1008 C->verify_graph_edges();
1009 if( VerifyOpto && allow_progress() ) {
1010 // Must turn off allow_progress to enable assert and break recursion
1011 C->root()->verify();
1012 { // Check if any progress was missed using IterGVN
1013 // Def-Use info enables transformations not attempted in wash-pass
1014 // e.g. Region/Phi cleanup, ...
1015 // Null-check elision -- may not have reached fixpoint
1016 // do not propagate to dominated nodes
1017 ResourceMark rm;
1018 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean!
1019 // Fill worklist completely
1020 igvn2.init_worklist(C->root());
1021
1022 igvn2.set_allow_progress(false);
1023 igvn2.optimize();
1024 igvn2.set_allow_progress(true);
1025 }
1026 }
1027 if (VerifyIterativeGVN && PrintOpto) {
1028 if (_verify_counter == _verify_full_passes) {
1029 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes",
1030 (int) _verify_full_passes);
1031 } else {
1032 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes",
1033 (int) _verify_counter, (int) _verify_full_passes);
1034 }
1035 }
1036
1037 #ifdef ASSERT
1038 while (modified_list->size()) {
1039 Node* n = modified_list->pop();
1040 n->dump();
1041 assert(false, "VerifyIterativeGVN: new modified node was added");
1042 }
1043 #endif
1044 }
1045 #endif /* PRODUCT */
1046
1047 #ifdef ASSERT
1048 /**
1049 * Dumps information that can help to debug the problem. A debug
1050 * build fails with an assert.
1051 */
1052 void PhaseIterGVN::dump_infinite_loop_info(Node* n) {
1053 n->dump(4);
1054 _worklist.dump();
1055 assert(false, "infinite loop in PhaseIterGVN::optimize");
1056 }
1057
1058 /**
1059 * Prints out information about IGVN if the 'verbose' option is used.
1060 */
1061 void PhaseIterGVN::trace_PhaseIterGVN_verbose(Node* n, int num_processed) {
1062 if (TraceIterativeGVN && Verbose) {
1063 tty->print(" Pop ");
1064 n->dump();
1065 if ((num_processed % 100) == 0) {
1066 _worklist.print_set();
1067 }
1068 }
1069 }
1070 #endif /* ASSERT */
1071
1072 void PhaseIterGVN::optimize() {
1073 DEBUG_ONLY(uint num_processed = 0;)
1074 NOT_PRODUCT(init_verifyPhaseIterGVN();)
1075
1076 uint loop_count = 0;
1077 // Pull from worklist and transform the node. If the node has changed,
1078 // update edge info and put uses on worklist.
1079 while(_worklist.size()) {
1080 if (C->check_node_count(NodeLimitFudgeFactor * 2, "Out of nodes")) {
1081 return;
1082 }
1083 Node* n = _worklist.pop();
1084 if (++loop_count >= K * C->live_nodes()) {
1085 DEBUG_ONLY(dump_infinite_loop_info(n);)
1086 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize");
1087 return;
1088 }
1089 DEBUG_ONLY(trace_PhaseIterGVN_verbose(n, num_processed++);)
1090 if (n->outcnt() != 0) {
1091 NOT_PRODUCT(const Type* oldtype = type_or_null(n));
1092 // Do the transformation
1093 Node* nn = transform_old(n);
1094 NOT_PRODUCT(trace_PhaseIterGVN(n, nn, oldtype);)
1095 } else if (!n->is_top()) {
1096 remove_dead_node(n);
1097 }
1098 }
1099 NOT_PRODUCT(verify_PhaseIterGVN();)
1100 }
1101
1102
1103 /**
1104 * Register a new node with the optimizer. Update the types array, the def-use
1105 * info. Put on worklist.
1106 */
1107 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) {
1108 set_type_bottom(n);
1109 _worklist.push(n);
1110 if (orig != NULL) C->copy_node_notes_to(n, orig);
1111 return n;
1112 }
1113
1114 //------------------------------transform--------------------------------------
1115 // Non-recursive: idealize Node 'n' with respect to its inputs and its value
1116 Node *PhaseIterGVN::transform( Node *n ) {
1117 if (_delay_transform) {
1118 // Register the node but don't optimize for now
1119 register_new_node_with_optimizer(n);
1120 return n;
1121 }
1122
1123 // If brand new node, make space in type array, and give it a type.
1124 ensure_type_or_null(n);
1125 if (type_or_null(n) == NULL) {
1126 set_type_bottom(n);
1127 }
1128
1129 return transform_old(n);
1130 }
1131
1132 Node *PhaseIterGVN::transform_old(Node* n) {
1133 DEBUG_ONLY(uint loop_count = 0;);
1134 NOT_PRODUCT(set_transforms());
1135
1136 // Remove 'n' from hash table in case it gets modified
1137 _table.hash_delete(n);
1138 if (VerifyIterativeGVN) {
1139 assert(!_table.find_index(n->_idx), "found duplicate entry in table");
1140 }
1141
1142 // Apply the Ideal call in a loop until it no longer applies
1143 Node* k = n;
1144 DEBUG_ONLY(dead_loop_check(k);)
1145 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);)
1146 C->remove_modified_node(k);
1147 Node* i = k->Ideal(this, /*can_reshape=*/true);
1148 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1149 #ifndef PRODUCT
1150 verify_step(k);
1151 if (i && VerifyOpto ) {
1152 if (!allow_progress()) {
1153 if (i->is_Add() && (i->outcnt() == 1)) {
1154 // Switched input to left side because this is the only use
1155 } else if (i->is_If() && (i->in(0) == NULL)) {
1156 // This IF is dead because it is dominated by an equivalent IF When
1157 // dominating if changed, info is not propagated sparsely to 'this'
1158 // Propagating this info further will spuriously identify other
1159 // progress.
1160 return i;
1161 } else
1162 set_progress();
1163 } else {
1164 set_progress();
1165 }
1166 }
1167 #endif
1168
1169 while (i != NULL) {
1170 #ifdef ASSERT
1171 if (loop_count >= K) {
1172 dump_infinite_loop_info(i);
1173 }
1174 loop_count++;
1175 #endif
1176 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes");
1177 // Made a change; put users of original Node on worklist
1178 add_users_to_worklist(k);
1179 // Replacing root of transform tree?
1180 if (k != i) {
1181 // Make users of old Node now use new.
1182 subsume_node(k, i);
1183 k = i;
1184 }
1185 DEBUG_ONLY(dead_loop_check(k);)
1186 // Try idealizing again
1187 DEBUG_ONLY(is_new = (k->outcnt() == 0);)
1188 C->remove_modified_node(k);
1189 i = k->Ideal(this, /*can_reshape=*/true);
1190 assert(i != k || is_new || (i->outcnt() > 0), "don't return dead nodes");
1191 #ifndef PRODUCT
1192 verify_step(k);
1193 if (i && VerifyOpto) {
1194 set_progress();
1195 }
1196 #endif
1197 }
1198
1199 // If brand new node, make space in type array.
1200 ensure_type_or_null(k);
1201
1202 // See what kind of values 'k' takes on at runtime
1203 const Type* t = k->Value(this);
1204 assert(t != NULL, "value sanity");
1205
1206 // Since I just called 'Value' to compute the set of run-time values
1207 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
1208 // cache Value. Later requests for the local phase->type of this Node can
1209 // use the cached Value instead of suffering with 'bottom_type'.
1210 if (type_or_null(k) != t) {
1211 #ifndef PRODUCT
1212 inc_new_values();
1213 set_progress();
1214 #endif
1215 set_type(k, t);
1216 // If k is a TypeNode, capture any more-precise type permanently into Node
1217 k->raise_bottom_type(t);
1218 // Move users of node to worklist
1219 add_users_to_worklist(k);
1220 }
1221 // If 'k' computes a constant, replace it with a constant
1222 if (t->singleton() && !k->is_Con()) {
1223 NOT_PRODUCT(set_progress();)
1224 Node* con = makecon(t); // Make a constant
1225 add_users_to_worklist(k);
1226 if (k->Opcode() == Op_ShenandoahWriteBarrier) {
1227 assert(con->is_top(), "can only replace barrier with top");
1228 }
1229 subsume_node(k, con); // Everybody using k now uses con
1230 return con;
1231 }
1232
1233 // Now check for Identities
1234 i = k->Identity(this); // Look for a nearby replacement
1235 if (i != k) { // Found? Return replacement!
1236 NOT_PRODUCT(set_progress();)
1237 add_users_to_worklist(k);
1238 subsume_node(k, i); // Everybody using k now uses i
1239 return i;
1240 }
1241
1242 // Global Value Numbering
1243 i = hash_find_insert(k); // Check for pre-existing node
1244 if (i && (i != k)) {
1245 // Return the pre-existing node if it isn't dead
1246 NOT_PRODUCT(set_progress();)
1247 add_users_to_worklist(k);
1248 subsume_node(k, i); // Everybody using k now uses i
1249 return i;
1250 }
1251
1252 // Return Idealized original
1253 return k;
1254 }
1255
1256 //---------------------------------saturate------------------------------------
1257 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type,
1258 const Type* limit_type) const {
1259 return new_type->narrow(old_type);
1260 }
1261
1262 //------------------------------remove_globally_dead_node----------------------
1263 // Kill a globally dead Node. All uses are also globally dead and are
1264 // aggressively trimmed.
1265 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) {
1266 enum DeleteProgress {
1267 PROCESS_INPUTS,
1268 PROCESS_OUTPUTS
1269 };
1270 assert(_stack.is_empty(), "not empty");
1271 _stack.push(dead, PROCESS_INPUTS);
1272
1273 while (_stack.is_nonempty()) {
1274 dead = _stack.node();
1275 uint progress_state = _stack.index();
1276 assert(dead != C->root(), "killing root, eh?");
1277 assert(!dead->is_top(), "add check for top when pushing");
1278 NOT_PRODUCT( set_progress(); )
1279 if (progress_state == PROCESS_INPUTS) {
1280 // After following inputs, continue to outputs
1281 _stack.set_index(PROCESS_OUTPUTS);
1282 if (!dead->is_Con()) { // Don't kill cons but uses
1283 bool recurse = false;
1284 // Remove from hash table
1285 _table.hash_delete( dead );
1286 // Smash all inputs to 'dead', isolating him completely
1287 for (uint i = 0; i < dead->req(); i++) {
1288 Node *in = dead->in(i);
1289 if (in != NULL && in != C->top()) { // Points to something?
1290 int nrep = dead->replace_edge(in, NULL); // Kill edges
1291 assert((nrep > 0), "sanity");
1292 if (in->outcnt() == 0) { // Made input go dead?
1293 _stack.push(in, PROCESS_INPUTS); // Recursively remove
1294 recurse = true;
1295 } else if (in->outcnt() == 1 &&
1296 in->has_special_unique_user()) {
1297 _worklist.push(in->unique_out());
1298 } else if (in->outcnt() <= 2 && dead->is_Phi()) {
1299 if (in->Opcode() == Op_Region) {
1300 _worklist.push(in);
1301 } else if (in->is_Store()) {
1302 DUIterator_Fast imax, i = in->fast_outs(imax);
1303 _worklist.push(in->fast_out(i));
1304 i++;
1305 if (in->outcnt() == 2) {
1306 _worklist.push(in->fast_out(i));
1307 i++;
1308 }
1309 assert(!(i < imax), "sanity");
1310 }
1311 }
1312 if (ReduceFieldZeroing && dead->is_Load() && i == MemNode::Memory &&
1313 in->is_Proj() && in->in(0) != NULL && in->in(0)->is_Initialize()) {
1314 // A Load that directly follows an InitializeNode is
1315 // going away. The Stores that follow are candidates
1316 // again to be captured by the InitializeNode.
1317 for (DUIterator_Fast jmax, j = in->fast_outs(jmax); j < jmax; j++) {
1318 Node *n = in->fast_out(j);
1319 if (n->is_Store()) {
1320 _worklist.push(n);
1321 }
1322 }
1323 }
1324 } // if (in != NULL && in != C->top())
1325 } // for (uint i = 0; i < dead->req(); i++)
1326 if (recurse) {
1327 continue;
1328 }
1329 } // if (!dead->is_Con())
1330 } // if (progress_state == PROCESS_INPUTS)
1331
1332 // Aggressively kill globally dead uses
1333 // (Rather than pushing all the outs at once, we push one at a time,
1334 // plus the parent to resume later, because of the indefinite number
1335 // of edge deletions per loop trip.)
1336 if (dead->outcnt() > 0) {
1337 // Recursively remove output edges
1338 _stack.push(dead->raw_out(0), PROCESS_INPUTS);
1339 } else {
1340 // Finished disconnecting all input and output edges.
1341 _stack.pop();
1342 // Remove dead node from iterative worklist
1343 _worklist.remove(dead);
1344 C->remove_modified_node(dead);
1345 // Constant node that has no out-edges and has only one in-edge from
1346 // root is usually dead. However, sometimes reshaping walk makes
1347 // it reachable by adding use edges. So, we will NOT count Con nodes
1348 // as dead to be conservative about the dead node count at any
1349 // given time.
1350 if (!dead->is_Con()) {
1351 C->record_dead_node(dead->_idx);
1352 }
1353 if (dead->is_macro()) {
1354 C->remove_macro_node(dead);
1355 }
1356 if (dead->is_expensive()) {
1357 C->remove_expensive_node(dead);
1358 }
1359 }
1360 } // while (_stack.is_nonempty())
1361 }
1362
1363 //------------------------------subsume_node-----------------------------------
1364 // Remove users from node 'old' and add them to node 'nn'.
1365 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
1366 assert( old != hash_find(old), "should already been removed" );
1367 assert( old != C->top(), "cannot subsume top node");
1368 // Copy debug or profile information to the new version:
1369 C->copy_node_notes_to(nn, old);
1370 // Move users of node 'old' to node 'nn'
1371 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) {
1372 Node* use = old->last_out(i); // for each use...
1373 // use might need re-hashing (but it won't if it's a new node)
1374 rehash_node_delayed(use);
1375 // Update use-def info as well
1376 // We remove all occurrences of old within use->in,
1377 // so as to avoid rehashing any node more than once.
1378 // The hash table probe swamps any outer loop overhead.
1379 uint num_edges = 0;
1380 for (uint jmax = use->len(), j = 0; j < jmax; j++) {
1381 if (use->in(j) == old) {
1382 use->set_req(j, nn);
1383 ++num_edges;
1384 }
1385 }
1386 i -= num_edges; // we deleted 1 or more copies of this edge
1387 }
1388
1389 // Smash all inputs to 'old', isolating him completely
1390 Node *temp = new Node(1);
1391 temp->init_req(0,nn); // Add a use to nn to prevent him from dying
1392 remove_dead_node( old );
1393 temp->del_req(0); // Yank bogus edge
1394 #ifndef PRODUCT
1395 if( VerifyIterativeGVN ) {
1396 for ( int i = 0; i < _verify_window_size; i++ ) {
1397 if ( _verify_window[i] == old )
1398 _verify_window[i] = nn;
1399 }
1400 }
1401 #endif
1402 _worklist.remove(temp); // this can be necessary
1403 temp->destruct(); // reuse the _idx of this little guy
1404 }
1405
1406 //------------------------------add_users_to_worklist--------------------------
1407 void PhaseIterGVN::add_users_to_worklist0( Node *n ) {
1408 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1409 _worklist.push(n->fast_out(i)); // Push on worklist
1410 }
1411 }
1412
1413 void PhaseIterGVN::add_users_to_worklist( Node *n ) {
1414 add_users_to_worklist0(n);
1415
1416 // Move users of node to worklist
1417 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1418 Node* use = n->fast_out(i); // Get use
1419
1420 if( use->is_Multi() || // Multi-definer? Push projs on worklist
1421 use->is_Store() ) // Enable store/load same address
1422 add_users_to_worklist0(use);
1423
1424 // If we changed the receiver type to a call, we need to revisit
1425 // the Catch following the call. It's looking for a non-NULL
1426 // receiver to know when to enable the regular fall-through path
1427 // in addition to the NullPtrException path.
1428 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) {
1429 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control);
1430 if (p != NULL) {
1431 add_users_to_worklist0(p);
1432 }
1433 }
1434
1435 uint use_op = use->Opcode();
1436 if(use->is_Cmp()) { // Enable CMP/BOOL optimization
1437 add_users_to_worklist(use); // Put Bool on worklist
1438 if (use->outcnt() > 0) {
1439 Node* bol = use->raw_out(0);
1440 if (bol->outcnt() > 0) {
1441 Node* iff = bol->raw_out(0);
1442 if (use_op == Op_CmpI &&
1443 iff->is_CountedLoopEnd()) {
1444 CountedLoopEndNode* cle = iff->as_CountedLoopEnd();
1445 if (cle->limit() == n && cle->phi() != NULL) {
1446 // If an opaque node feeds into the limit condition of a
1447 // CountedLoop, we need to process the Phi node for the
1448 // induction variable when the opaque node is removed:
1449 // the range of values taken by the Phi is now known and
1450 // so its type is also known.
1451 _worklist.push(cle->phi());
1452 }
1453 } else if (iff->outcnt() == 2) {
1454 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the
1455 // phi merging either 0 or 1 onto the worklist
1456 Node* ifproj0 = iff->raw_out(0);
1457 Node* ifproj1 = iff->raw_out(1);
1458 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) {
1459 Node* region0 = ifproj0->raw_out(0);
1460 Node* region1 = ifproj1->raw_out(0);
1461 if( region0 == region1 )
1462 add_users_to_worklist0(region0);
1463 }
1464 }
1465 }
1466 }
1467 if (use_op == Op_CmpI) {
1468 Node* in1 = use->in(1);
1469 for (uint i = 0; i < in1->outcnt(); i++) {
1470 if (in1->raw_out(i)->Opcode() == Op_CastII) {
1471 Node* castii = in1->raw_out(i);
1472 if (castii->in(0) != NULL && castii->in(0)->in(0) != NULL && castii->in(0)->in(0)->is_If()) {
1473 Node* ifnode = castii->in(0)->in(0);
1474 if (ifnode->in(1) != NULL && ifnode->in(1)->is_Bool() && ifnode->in(1)->in(1) == use) {
1475 // Reprocess a CastII node that may depend on an
1476 // opaque node value when the opaque node is
1477 // removed. In case it carries a dependency we can do
1478 // a better job of computing its type.
1479 _worklist.push(castii);
1480 }
1481 }
1482 }
1483 }
1484 }
1485 }
1486
1487 // If changed Cast input, check Phi users for simple cycles
1488 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) {
1489 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1490 Node* u = use->fast_out(i2);
1491 if (u->is_Phi())
1492 _worklist.push(u);
1493 }
1494 }
1495 // If changed LShift inputs, check RShift users for useless sign-ext
1496 if( use_op == Op_LShiftI ) {
1497 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1498 Node* u = use->fast_out(i2);
1499 if (u->Opcode() == Op_RShiftI)
1500 _worklist.push(u);
1501 }
1502 }
1503 // If changed AddI/SubI inputs, check CmpU for range check optimization.
1504 if (use_op == Op_AddI || use_op == Op_SubI) {
1505 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1506 Node* u = use->fast_out(i2);
1507 if (u->is_Cmp() && (u->Opcode() == Op_CmpU)) {
1508 _worklist.push(u);
1509 }
1510 }
1511 }
1512 // If changed AddP inputs, check Stores for loop invariant
1513 if( use_op == Op_AddP ) {
1514 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1515 Node* u = use->fast_out(i2);
1516 if (u->is_Mem())
1517 _worklist.push(u);
1518 }
1519 }
1520 // If changed initialization activity, check dependent Stores
1521 if (use_op == Op_Allocate || use_op == Op_AllocateArray) {
1522 InitializeNode* init = use->as_Allocate()->initialization();
1523 if (init != NULL) {
1524 Node* imem = init->proj_out(TypeFunc::Memory);
1525 if (imem != NULL) add_users_to_worklist0(imem);
1526 }
1527 }
1528 if (use_op == Op_Initialize) {
1529 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory);
1530 if (imem != NULL) add_users_to_worklist0(imem);
1531 }
1532 }
1533 }
1534
1535 /**
1536 * Remove the speculative part of all types that we know of
1537 */
1538 void PhaseIterGVN::remove_speculative_types() {
1539 assert(UseTypeSpeculation, "speculation is off");
1540 for (uint i = 0; i < _types.Size(); i++) {
1541 const Type* t = _types.fast_lookup(i);
1542 if (t != NULL) {
1543 _types.map(i, t->remove_speculative());
1544 }
1545 }
1546 _table.check_no_speculative_types();
1547 }
1548
1549 //=============================================================================
1550 #ifndef PRODUCT
1551 uint PhaseCCP::_total_invokes = 0;
1552 uint PhaseCCP::_total_constants = 0;
1553 #endif
1554 //------------------------------PhaseCCP---------------------------------------
1555 // Conditional Constant Propagation, ala Wegman & Zadeck
1556 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) {
1557 NOT_PRODUCT( clear_constants(); )
1558 assert( _worklist.size() == 0, "" );
1559 // Clear out _nodes from IterGVN. Must be clear to transform call.
1560 _nodes.clear(); // Clear out from IterGVN
1561 analyze();
1562 }
1563
1564 #ifndef PRODUCT
1565 //------------------------------~PhaseCCP--------------------------------------
1566 PhaseCCP::~PhaseCCP() {
1567 inc_invokes();
1568 _total_constants += count_constants();
1569 }
1570 #endif
1571
1572
1573 #ifdef ASSERT
1574 static bool ccp_type_widens(const Type* t, const Type* t0) {
1575 assert(t->meet(t0) == t, "Not monotonic");
1576 switch (t->base() == t0->base() ? t->base() : Type::Top) {
1577 case Type::Int:
1578 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases");
1579 break;
1580 case Type::Long:
1581 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases");
1582 break;
1583 }
1584 return true;
1585 }
1586 #endif //ASSERT
1587
1588 //------------------------------analyze----------------------------------------
1589 void PhaseCCP::analyze() {
1590 // Initialize all types to TOP, optimistic analysis
1591 for (int i = C->unique() - 1; i >= 0; i--) {
1592 _types.map(i,Type::TOP);
1593 }
1594
1595 // Push root onto worklist
1596 Unique_Node_List worklist;
1597 worklist.push(C->root());
1598
1599 // Pull from worklist; compute new value; push changes out.
1600 // This loop is the meat of CCP.
1601 while( worklist.size() ) {
1602 Node *n = worklist.pop();
1603 const Type *t = n->Value(this);
1604 if (t != type(n)) {
1605 assert(ccp_type_widens(t, type(n)), "ccp type must widen");
1606 #ifndef PRODUCT
1607 if( TracePhaseCCP ) {
1608 t->dump();
1609 do { tty->print("\t"); } while (tty->position() < 16);
1610 n->dump();
1611 }
1612 #endif
1613 set_type(n, t);
1614 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1615 Node* m = n->fast_out(i); // Get user
1616 if (m->is_Region()) { // New path to Region? Must recheck Phis too
1617 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1618 Node* p = m->fast_out(i2); // Propagate changes to uses
1619 if (p->bottom_type() != type(p)) { // If not already bottomed out
1620 worklist.push(p); // Propagate change to user
1621 }
1622 }
1623 }
1624 // If we changed the receiver type to a call, we need to revisit
1625 // the Catch following the call. It's looking for a non-NULL
1626 // receiver to know when to enable the regular fall-through path
1627 // in addition to the NullPtrException path
1628 if (m->is_Call()) {
1629 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1630 Node* p = m->fast_out(i2); // Propagate changes to uses
1631 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1) {
1632 worklist.push(p->unique_out());
1633 }
1634 }
1635 }
1636 if (m->bottom_type() != type(m)) { // If not already bottomed out
1637 worklist.push(m); // Propagate change to user
1638 }
1639
1640 // CmpU nodes can get their type information from two nodes up in the
1641 // graph (instead of from the nodes immediately above). Make sure they
1642 // are added to the worklist if nodes they depend on are updated, since
1643 // they could be missed and get wrong types otherwise.
1644 uint m_op = m->Opcode();
1645 if (m_op == Op_AddI || m_op == Op_SubI) {
1646 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1647 Node* p = m->fast_out(i2); // Propagate changes to uses
1648 if (p->Opcode() == Op_CmpU) {
1649 // Got a CmpU which might need the new type information from node n.
1650 if(p->bottom_type() != type(p)) { // If not already bottomed out
1651 worklist.push(p); // Propagate change to user
1652 }
1653 }
1654 }
1655 }
1656 }
1657 }
1658 }
1659 }
1660
1661 //------------------------------do_transform-----------------------------------
1662 // Top level driver for the recursive transformer
1663 void PhaseCCP::do_transform() {
1664 // Correct leaves of new-space Nodes; they point to old-space.
1665 C->set_root( transform(C->root())->as_Root() );
1666 assert( C->top(), "missing TOP node" );
1667 assert( C->root(), "missing root" );
1668 }
1669
1670 //------------------------------transform--------------------------------------
1671 // Given a Node in old-space, clone him into new-space.
1672 // Convert any of his old-space children into new-space children.
1673 Node *PhaseCCP::transform( Node *n ) {
1674 Node *new_node = _nodes[n->_idx]; // Check for transformed node
1675 if( new_node != NULL )
1676 return new_node; // Been there, done that, return old answer
1677 new_node = transform_once(n); // Check for constant
1678 _nodes.map( n->_idx, new_node ); // Flag as having been cloned
1679
1680 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc
1681 GrowableArray <Node *> trstack(C->live_nodes() >> 1);
1682
1683 trstack.push(new_node); // Process children of cloned node
1684 while ( trstack.is_nonempty() ) {
1685 Node *clone = trstack.pop();
1686 uint cnt = clone->req();
1687 for( uint i = 0; i < cnt; i++ ) { // For all inputs do
1688 Node *input = clone->in(i);
1689 if( input != NULL ) { // Ignore NULLs
1690 Node *new_input = _nodes[input->_idx]; // Check for cloned input node
1691 if( new_input == NULL ) {
1692 new_input = transform_once(input); // Check for constant
1693 _nodes.map( input->_idx, new_input );// Flag as having been cloned
1694 trstack.push(new_input);
1695 }
1696 assert( new_input == clone->in(i), "insanity check");
1697 }
1698 }
1699 }
1700 return new_node;
1701 }
1702
1703
1704 //------------------------------transform_once---------------------------------
1705 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant.
1706 Node *PhaseCCP::transform_once( Node *n ) {
1707 const Type *t = type(n);
1708 // Constant? Use constant Node instead
1709 if( t->singleton() ) {
1710 Node *nn = n; // Default is to return the original constant
1711 if( t == Type::TOP ) {
1712 // cache my top node on the Compile instance
1713 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) {
1714 C->set_cached_top_node(ConNode::make(Type::TOP));
1715 set_type(C->top(), Type::TOP);
1716 }
1717 nn = C->top();
1718 }
1719 if( !n->is_Con() ) {
1720 if( t != Type::TOP ) {
1721 nn = makecon(t); // ConNode::make(t);
1722 NOT_PRODUCT( inc_constants(); )
1723 } else if( n->is_Region() ) { // Unreachable region
1724 // Note: nn == C->top()
1725 n->set_req(0, NULL); // Cut selfreference
1726 // Eagerly remove dead phis to avoid phis copies creation.
1727 for (DUIterator i = n->outs(); n->has_out(i); i++) {
1728 Node* m = n->out(i);
1729 if( m->is_Phi() ) {
1730 assert(type(m) == Type::TOP, "Unreachable region should not have live phis.");
1731 replace_node(m, nn);
1732 --i; // deleted this phi; rescan starting with next position
1733 }
1734 }
1735 }
1736 replace_node(n,nn); // Update DefUse edges for new constant
1737 }
1738 return nn;
1739 }
1740
1741 // If x is a TypeNode, capture any more-precise type permanently into Node
1742 if (t != n->bottom_type()) {
1743 hash_delete(n); // changing bottom type may force a rehash
1744 n->raise_bottom_type(t);
1745 _worklist.push(n); // n re-enters the hash table via the worklist
1746 }
1747
1748 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks
1749 switch( n->Opcode() ) {
1750 case Op_FastLock: // Revisit FastLocks for lock coarsening
1751 case Op_If:
1752 case Op_CountedLoopEnd:
1753 case Op_Region:
1754 case Op_Loop:
1755 case Op_CountedLoop:
1756 case Op_Conv2B:
1757 case Op_Opaque1:
1758 case Op_Opaque2:
1759 _worklist.push(n);
1760 break;
1761 default:
1762 break;
1763 }
1764
1765 return n;
1766 }
1767
1768 //---------------------------------saturate------------------------------------
1769 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type,
1770 const Type* limit_type) const {
1771 const Type* wide_type = new_type->widen(old_type, limit_type);
1772 if (wide_type != new_type) { // did we widen?
1773 // If so, we may have widened beyond the limit type. Clip it back down.
1774 new_type = wide_type->filter(limit_type);
1775 }
1776 return new_type;
1777 }
1778
1779 //------------------------------print_statistics-------------------------------
1780 #ifndef PRODUCT
1781 void PhaseCCP::print_statistics() {
1782 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants);
1783 }
1784 #endif
1785
1786
1787 //=============================================================================
1788 #ifndef PRODUCT
1789 uint PhasePeephole::_total_peepholes = 0;
1790 #endif
1791 //------------------------------PhasePeephole----------------------------------
1792 // Conditional Constant Propagation, ala Wegman & Zadeck
1793 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg )
1794 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) {
1795 NOT_PRODUCT( clear_peepholes(); )
1796 }
1797
1798 #ifndef PRODUCT
1799 //------------------------------~PhasePeephole---------------------------------
1800 PhasePeephole::~PhasePeephole() {
1801 _total_peepholes += count_peepholes();
1802 }
1803 #endif
1804
1805 //------------------------------transform--------------------------------------
1806 Node *PhasePeephole::transform( Node *n ) {
1807 ShouldNotCallThis();
1808 return NULL;
1809 }
1810
1811 //------------------------------do_transform-----------------------------------
1812 void PhasePeephole::do_transform() {
1813 bool method_name_not_printed = true;
1814
1815 // Examine each basic block
1816 for (uint block_number = 1; block_number < _cfg.number_of_blocks(); ++block_number) {
1817 Block* block = _cfg.get_block(block_number);
1818 bool block_not_printed = true;
1819
1820 // and each instruction within a block
1821 uint end_index = block->number_of_nodes();
1822 // block->end_idx() not valid after PhaseRegAlloc
1823 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) {
1824 Node *n = block->get_node(instruction_index);
1825 if( n->is_Mach() ) {
1826 MachNode *m = n->as_Mach();
1827 int deleted_count = 0;
1828 // check for peephole opportunities
1829 MachNode *m2 = m->peephole(block, instruction_index, _regalloc, deleted_count);
1830 if( m2 != NULL ) {
1831 #ifndef PRODUCT
1832 if( PrintOptoPeephole ) {
1833 // Print method, first time only
1834 if( C->method() && method_name_not_printed ) {
1835 C->method()->print_short_name(); tty->cr();
1836 method_name_not_printed = false;
1837 }
1838 // Print this block
1839 if( Verbose && block_not_printed) {
1840 tty->print_cr("in block");
1841 block->dump();
1842 block_not_printed = false;
1843 }
1844 // Print instructions being deleted
1845 for( int i = (deleted_count - 1); i >= 0; --i ) {
1846 block->get_node(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr();
1847 }
1848 tty->print_cr("replaced with");
1849 // Print new instruction
1850 m2->format(_regalloc);
1851 tty->print("\n\n");
1852 }
1853 #endif
1854 // Remove old nodes from basic block and update instruction_index
1855 // (old nodes still exist and may have edges pointing to them
1856 // as register allocation info is stored in the allocator using
1857 // the node index to live range mappings.)
1858 uint safe_instruction_index = (instruction_index - deleted_count);
1859 for( ; (instruction_index > safe_instruction_index); --instruction_index ) {
1860 block->remove_node( instruction_index );
1861 }
1862 // install new node after safe_instruction_index
1863 block->insert_node(m2, safe_instruction_index + 1);
1864 end_index = block->number_of_nodes() - 1; // Recompute new block size
1865 NOT_PRODUCT( inc_peepholes(); )
1866 }
1867 }
1868 }
1869 }
1870 }
1871
1872 //------------------------------print_statistics-------------------------------
1873 #ifndef PRODUCT
1874 void PhasePeephole::print_statistics() {
1875 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes);
1876 }
1877 #endif
1878
1879
1880 //=============================================================================
1881 //------------------------------set_req_X--------------------------------------
1882 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1883 assert( is_not_dead(n), "can not use dead node");
1884 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1885 Node *old = in(i);
1886 set_req(i, n);
1887
1888 // old goes dead?
1889 if( old ) {
1890 switch (old->outcnt()) {
1891 case 0:
1892 // Put into the worklist to kill later. We do not kill it now because the
1893 // recursive kill will delete the current node (this) if dead-loop exists
1894 if (!old->is_top())
1895 igvn->_worklist.push( old );
1896 break;
1897 case 1:
1898 if( old->is_Store() || old->has_special_unique_user() )
1899 igvn->add_users_to_worklist( old );
1900 break;
1901 case 2:
1902 if( old->is_Store() )
1903 igvn->add_users_to_worklist( old );
1904 if( old->Opcode() == Op_Region )
1905 igvn->_worklist.push(old);
1906 break;
1907 case 3:
1908 if( old->Opcode() == Op_Region ) {
1909 igvn->_worklist.push(old);
1910 igvn->add_users_to_worklist( old );
1911 }
1912 break;
1913 default:
1914 break;
1915 }
1916 }
1917
1918 }
1919
1920 //-------------------------------replace_by-----------------------------------
1921 // Using def-use info, replace one node for another. Follow the def-use info
1922 // to all users of the OLD node. Then make all uses point to the NEW node.
1923 void Node::replace_by(Node *new_node) {
1924 assert(!is_top(), "top node has no DU info");
1925 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) {
1926 Node* use = last_out(i);
1927 uint uses_found = 0;
1928 for (uint j = 0; j < use->len(); j++) {
1929 if (use->in(j) == this) {
1930 if (j < use->req())
1931 use->set_req(j, new_node);
1932 else use->set_prec(j, new_node);
1933 uses_found++;
1934 }
1935 }
1936 i -= uses_found; // we deleted 1 or more copies of this edge
1937 }
1938 }
1939
1940 //=============================================================================
1941 //-----------------------------------------------------------------------------
1942 void Type_Array::grow( uint i ) {
1943 if( !_max ) {
1944 _max = 1;
1945 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) );
1946 _types[0] = NULL;
1947 }
1948 uint old = _max;
1949 while( i >= _max ) _max <<= 1; // Double to fit
1950 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*));
1951 memset( &_types[old], 0, (_max-old)*sizeof(Type*) );
1952 }
1953
1954 //------------------------------dump-------------------------------------------
1955 #ifndef PRODUCT
1956 void Type_Array::dump() const {
1957 uint max = Size();
1958 for( uint i = 0; i < max; i++ ) {
1959 if( _types[i] != NULL ) {
1960 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr();
1961 }
1962 }
1963 }
1964 #endif