Mercurial > jdk8-mips64-public > hotspot / file revision
src/share/vm/opto/phaseX.cpp@d2a62e0f25eb
src/share/vm/opto/phaseX.cpp
Thu, 28 Jun 2012 17:03:16 -0400
- author
- zgu
- date
- Thu, 28 Jun 2012 17:03:16 -0400
- changeset 3900
- d2a62e0f25eb
- parent 3260
- 670a74b863fc
- child 3947
- 611e8a669a2c
- permissions
- -rw-r--r--
6995781: Native Memory Tracking (Phase 1)
7151532: DCmd for hotspot native memory tracking
Summary: Implementation of native memory tracking phase 1, which tracks VM native memory usage, and related DCmd
Reviewed-by: acorn, coleenp, fparain
1 /*
2 * Copyright (c) 1997, 2011, 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 */
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/connode.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"
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 _look_probes(0), _lookup_hits(0), _lookup_misses(0),
48 _total_insert_probes(0), _total_inserts(0),
49 _insert_probes(0), _grows(0) {
50 // _sentinel must be in the current node space
51 _sentinel = new (Compile::current(), 1) ProjNode(NULL, TypeFunc::Control);
52 memset(_table,0,sizeof(Node*)*_max);
53 }
55 //------------------------------NodeHash---------------------------------------
56 NodeHash::NodeHash(Arena *arena, uint est_max_size) :
57 _max( round_up(est_max_size < NODE_HASH_MINIMUM_SIZE ? NODE_HASH_MINIMUM_SIZE : est_max_size) ),
58 _a(arena),
59 _table( NEW_ARENA_ARRAY( _a , Node* , _max ) ),
60 _inserts(0), _insert_limit( insert_limit() ),
61 _look_probes(0), _lookup_hits(0), _lookup_misses(0),
62 _delete_probes(0), _delete_hits(0), _delete_misses(0),
63 _total_insert_probes(0), _total_inserts(0),
64 _insert_probes(0), _grows(0) {
65 // _sentinel must be in the current node space
66 _sentinel = new (Compile::current(), 1) ProjNode(NULL, TypeFunc::Control);
67 memset(_table,0,sizeof(Node*)*_max);
68 }
70 //------------------------------NodeHash---------------------------------------
71 NodeHash::NodeHash(NodeHash *nh) {
72 debug_only(_table = (Node**)badAddress); // interact correctly w/ operator=
73 // just copy in all the fields
74 *this = *nh;
75 // nh->_sentinel must be in the current node space
76 }
78 //------------------------------hash_find--------------------------------------
79 // Find in hash table
80 Node *NodeHash::hash_find( const Node *n ) {
81 // ((Node*)n)->set_hash( n->hash() );
82 uint hash = n->hash();
83 if (hash == Node::NO_HASH) {
84 debug_only( _lookup_misses++ );
85 return NULL;
86 }
87 uint key = hash & (_max-1);
88 uint stride = key | 0x01;
89 debug_only( _look_probes++ );
90 Node *k = _table[key]; // Get hashed value
91 if( !k ) { // ?Miss?
92 debug_only( _lookup_misses++ );
93 return NULL; // Miss!
94 }
96 int op = n->Opcode();
97 uint req = n->req();
98 while( 1 ) { // While probing hash table
99 if( k->req() == req && // Same count of inputs
100 k->Opcode() == op ) { // Same Opcode
101 for( uint i=0; i<req; i++ )
102 if( n->in(i)!=k->in(i)) // Different inputs?
103 goto collision; // "goto" is a speed hack...
104 if( n->cmp(*k) ) { // Check for any special bits
105 debug_only( _lookup_hits++ );
106 return k; // Hit!
107 }
108 }
109 collision:
110 debug_only( _look_probes++ );
111 key = (key + stride/*7*/) & (_max-1); // Stride through table with relative prime
112 k = _table[key]; // Get hashed value
113 if( !k ) { // ?Miss?
114 debug_only( _lookup_misses++ );
115 return NULL; // Miss!
116 }
117 }
118 ShouldNotReachHere();
119 return NULL;
120 }
122 //------------------------------hash_find_insert-------------------------------
123 // Find in hash table, insert if not already present
124 // Used to preserve unique entries in hash table
125 Node *NodeHash::hash_find_insert( Node *n ) {
126 // n->set_hash( );
127 uint hash = n->hash();
128 if (hash == Node::NO_HASH) {
129 debug_only( _lookup_misses++ );
130 return NULL;
131 }
132 uint key = hash & (_max-1);
133 uint stride = key | 0x01; // stride must be relatively prime to table siz
134 uint first_sentinel = 0; // replace a sentinel if seen.
135 debug_only( _look_probes++ );
136 Node *k = _table[key]; // Get hashed value
137 if( !k ) { // ?Miss?
138 debug_only( _lookup_misses++ );
139 _table[key] = n; // Insert into table!
140 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
141 check_grow(); // Grow table if insert hit limit
142 return NULL; // Miss!
143 }
144 else if( k == _sentinel ) {
145 first_sentinel = key; // Can insert here
146 }
148 int op = n->Opcode();
149 uint req = n->req();
150 while( 1 ) { // While probing hash table
151 if( k->req() == req && // Same count of inputs
152 k->Opcode() == op ) { // Same Opcode
153 for( uint i=0; i<req; i++ )
154 if( n->in(i)!=k->in(i)) // Different inputs?
155 goto collision; // "goto" is a speed hack...
156 if( n->cmp(*k) ) { // Check for any special bits
157 debug_only( _lookup_hits++ );
158 return k; // Hit!
159 }
160 }
161 collision:
162 debug_only( _look_probes++ );
163 key = (key + stride) & (_max-1); // Stride through table w/ relative prime
164 k = _table[key]; // Get hashed value
165 if( !k ) { // ?Miss?
166 debug_only( _lookup_misses++ );
167 key = (first_sentinel == 0) ? key : first_sentinel; // ?saw sentinel?
168 _table[key] = n; // Insert into table!
169 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
170 check_grow(); // Grow table if insert hit limit
171 return NULL; // Miss!
172 }
173 else if( first_sentinel == 0 && k == _sentinel ) {
174 first_sentinel = key; // Can insert here
175 }
177 }
178 ShouldNotReachHere();
179 return NULL;
180 }
182 //------------------------------hash_insert------------------------------------
183 // Insert into hash table
184 void NodeHash::hash_insert( Node *n ) {
185 // // "conflict" comments -- print nodes that conflict
186 // bool conflict = false;
187 // n->set_hash();
188 uint hash = n->hash();
189 if (hash == Node::NO_HASH) {
190 return;
191 }
192 check_grow();
193 uint key = hash & (_max-1);
194 uint stride = key | 0x01;
196 while( 1 ) { // While probing hash table
197 debug_only( _insert_probes++ );
198 Node *k = _table[key]; // Get hashed value
199 if( !k || (k == _sentinel) ) break; // Found a slot
200 assert( k != n, "already inserted" );
201 // if( PrintCompilation && PrintOptoStatistics && Verbose ) { tty->print(" conflict: "); k->dump(); conflict = true; }
202 key = (key + stride) & (_max-1); // Stride through table w/ relative prime
203 }
204 _table[key] = n; // Insert into table!
205 debug_only(n->enter_hash_lock()); // Lock down the node while in the table.
206 // if( conflict ) { n->dump(); }
207 }
209 //------------------------------hash_delete------------------------------------
210 // Replace in hash table with sentinel
211 bool NodeHash::hash_delete( const Node *n ) {
212 Node *k;
213 uint hash = n->hash();
214 if (hash == Node::NO_HASH) {
215 debug_only( _delete_misses++ );
216 return false;
217 }
218 uint key = hash & (_max-1);
219 uint stride = key | 0x01;
220 debug_only( uint counter = 0; );
221 for( ; /* (k != NULL) && (k != _sentinel) */; ) {
222 debug_only( counter++ );
223 debug_only( _delete_probes++ );
224 k = _table[key]; // Get hashed value
225 if( !k ) { // Miss?
226 debug_only( _delete_misses++ );
227 #ifdef ASSERT
228 if( VerifyOpto ) {
229 for( uint i=0; i < _max; i++ )
230 assert( _table[i] != n, "changed edges with rehashing" );
231 }
232 #endif
233 return false; // Miss! Not in chain
234 }
235 else if( n == k ) {
236 debug_only( _delete_hits++ );
237 _table[key] = _sentinel; // Hit! Label as deleted entry
238 debug_only(((Node*)n)->exit_hash_lock()); // Unlock the node upon removal from table.
239 return true;
240 }
241 else {
242 // collision: move through table with prime offset
243 key = (key + stride/*7*/) & (_max-1);
244 assert( counter <= _insert_limit, "Cycle in hash-table");
245 }
246 }
247 ShouldNotReachHere();
248 return false;
249 }
251 //------------------------------round_up---------------------------------------
252 // Round up to nearest power of 2
253 uint NodeHash::round_up( uint x ) {
254 x += (x>>2); // Add 25% slop
255 if( x <16 ) return 16; // Small stuff
256 uint i=16;
257 while( i < x ) i <<= 1; // Double to fit
258 return i; // Return hash table size
259 }
261 //------------------------------grow-------------------------------------------
262 // Grow _table to next power of 2 and insert old entries
263 void NodeHash::grow() {
264 // Record old state
265 uint old_max = _max;
266 Node **old_table = _table;
267 // Construct new table with twice the space
268 _grows++;
269 _total_inserts += _inserts;
270 _total_insert_probes += _insert_probes;
271 _inserts = 0;
272 _insert_probes = 0;
273 _max = _max << 1;
274 _table = NEW_ARENA_ARRAY( _a , Node* , _max ); // (Node**)_a->Amalloc( _max * sizeof(Node*) );
275 memset(_table,0,sizeof(Node*)*_max);
276 _insert_limit = insert_limit();
277 // Insert old entries into the new table
278 for( uint i = 0; i < old_max; i++ ) {
279 Node *m = *old_table++;
280 if( !m || m == _sentinel ) continue;
281 debug_only(m->exit_hash_lock()); // Unlock the node upon removal from old table.
282 hash_insert(m);
283 }
284 }
286 //------------------------------clear------------------------------------------
287 // Clear all entries in _table to NULL but keep storage
288 void NodeHash::clear() {
289 #ifdef ASSERT
290 // Unlock all nodes upon removal from table.
291 for (uint i = 0; i < _max; i++) {
292 Node* n = _table[i];
293 if (!n || n == _sentinel) continue;
294 n->exit_hash_lock();
295 }
296 #endif
298 memset( _table, 0, _max * sizeof(Node*) );
299 }
301 //-----------------------remove_useless_nodes----------------------------------
302 // Remove useless nodes from value table,
303 // implementation does not depend on hash function
304 void NodeHash::remove_useless_nodes(VectorSet &useful) {
306 // Dead nodes in the hash table inherited from GVN should not replace
307 // existing nodes, remove dead nodes.
308 uint max = size();
309 Node *sentinel_node = sentinel();
310 for( uint i = 0; i < max; ++i ) {
311 Node *n = at(i);
312 if(n != NULL && n != sentinel_node && !useful.test(n->_idx)) {
313 debug_only(n->exit_hash_lock()); // Unlock the node when removed
314 _table[i] = sentinel_node; // Replace with placeholder
315 }
316 }
317 }
319 #ifndef PRODUCT
320 //------------------------------dump-------------------------------------------
321 // Dump statistics for the hash table
322 void NodeHash::dump() {
323 _total_inserts += _inserts;
324 _total_insert_probes += _insert_probes;
325 if (PrintCompilation && PrintOptoStatistics && Verbose && (_inserts > 0)) {
326 if (WizardMode) {
327 for (uint i=0; i<_max; i++) {
328 if (_table[i])
329 tty->print("%d/%d/%d ",i,_table[i]->hash()&(_max-1),_table[i]->_idx);
330 }
331 }
332 tty->print("\nGVN Hash stats: %d grows to %d max_size\n", _grows, _max);
333 tty->print(" %d/%d (%8.1f%% full)\n", _inserts, _max, (double)_inserts/_max*100.0);
334 tty->print(" %dp/(%dh+%dm) (%8.2f probes/lookup)\n", _look_probes, _lookup_hits, _lookup_misses, (double)_look_probes/(_lookup_hits+_lookup_misses));
335 tty->print(" %dp/%di (%8.2f probes/insert)\n", _total_insert_probes, _total_inserts, (double)_total_insert_probes/_total_inserts);
336 // sentinels increase lookup cost, but not insert cost
337 assert((_lookup_misses+_lookup_hits)*4+100 >= _look_probes, "bad hash function");
338 assert( _inserts+(_inserts>>3) < _max, "table too full" );
339 assert( _inserts*3+100 >= _insert_probes, "bad hash function" );
340 }
341 }
343 Node *NodeHash::find_index(uint idx) { // For debugging
344 // Find an entry by its index value
345 for( uint i = 0; i < _max; i++ ) {
346 Node *m = _table[i];
347 if( !m || m == _sentinel ) continue;
348 if( m->_idx == (uint)idx ) return m;
349 }
350 return NULL;
351 }
352 #endif
354 #ifdef ASSERT
355 NodeHash::~NodeHash() {
356 // Unlock all nodes upon destruction of table.
357 if (_table != (Node**)badAddress) clear();
358 }
360 void NodeHash::operator=(const NodeHash& nh) {
361 // Unlock all nodes upon replacement of table.
362 if (&nh == this) return;
363 if (_table != (Node**)badAddress) clear();
364 memcpy(this, &nh, sizeof(*this));
365 // Do not increment hash_lock counts again.
366 // Instead, be sure we never again use the source table.
367 ((NodeHash*)&nh)->_table = (Node**)badAddress;
368 }
371 #endif
374 //=============================================================================
375 //------------------------------PhaseRemoveUseless-----------------------------
376 // 1) Use a breadthfirst walk to collect useful nodes reachable from root.
377 PhaseRemoveUseless::PhaseRemoveUseless( PhaseGVN *gvn, Unique_Node_List *worklist ) : Phase(Remove_Useless),
378 _useful(Thread::current()->resource_area()) {
380 // Implementation requires 'UseLoopSafepoints == true' and an edge from root
381 // to each SafePointNode at a backward branch. Inserted in add_safepoint().
382 if( !UseLoopSafepoints || !OptoRemoveUseless ) return;
384 // Identify nodes that are reachable from below, useful.
385 C->identify_useful_nodes(_useful);
387 // Remove all useless nodes from PhaseValues' recorded types
388 // Must be done before disconnecting nodes to preserve hash-table-invariant
389 gvn->remove_useless_nodes(_useful.member_set());
391 // Remove all useless nodes from future worklist
392 worklist->remove_useless_nodes(_useful.member_set());
394 // Disconnect 'useless' nodes that are adjacent to useful nodes
395 C->remove_useless_nodes(_useful);
397 // Remove edges from "root" to each SafePoint at a backward branch.
398 // They were inserted during parsing (see add_safepoint()) to make infinite
399 // loops without calls or exceptions visible to root, i.e., useful.
400 Node *root = C->root();
401 if( root != NULL ) {
402 for( uint i = root->req(); i < root->len(); ++i ) {
403 Node *n = root->in(i);
404 if( n != NULL && n->is_SafePoint() ) {
405 root->rm_prec(i);
406 --i;
407 }
408 }
409 }
410 }
413 //=============================================================================
414 //------------------------------PhaseTransform---------------------------------
415 PhaseTransform::PhaseTransform( PhaseNumber pnum ) : Phase(pnum),
416 _arena(Thread::current()->resource_area()),
417 _nodes(_arena),
418 _types(_arena)
419 {
420 init_con_caches();
421 #ifndef PRODUCT
422 clear_progress();
423 clear_transforms();
424 set_allow_progress(true);
425 #endif
426 // Force allocation for currently existing nodes
427 _types.map(C->unique(), NULL);
428 }
430 //------------------------------PhaseTransform---------------------------------
431 PhaseTransform::PhaseTransform( Arena *arena, PhaseNumber pnum ) : Phase(pnum),
432 _arena(arena),
433 _nodes(arena),
434 _types(arena)
435 {
436 init_con_caches();
437 #ifndef PRODUCT
438 clear_progress();
439 clear_transforms();
440 set_allow_progress(true);
441 #endif
442 // Force allocation for currently existing nodes
443 _types.map(C->unique(), NULL);
444 }
446 //------------------------------PhaseTransform---------------------------------
447 // Initialize with previously generated type information
448 PhaseTransform::PhaseTransform( PhaseTransform *pt, PhaseNumber pnum ) : Phase(pnum),
449 _arena(pt->_arena),
450 _nodes(pt->_nodes),
451 _types(pt->_types)
452 {
453 init_con_caches();
454 #ifndef PRODUCT
455 clear_progress();
456 clear_transforms();
457 set_allow_progress(true);
458 #endif
459 }
461 void PhaseTransform::init_con_caches() {
462 memset(_icons,0,sizeof(_icons));
463 memset(_lcons,0,sizeof(_lcons));
464 memset(_zcons,0,sizeof(_zcons));
465 }
468 //--------------------------------find_int_type--------------------------------
469 const TypeInt* PhaseTransform::find_int_type(Node* n) {
470 if (n == NULL) return NULL;
471 // Call type_or_null(n) to determine node's type since we might be in
472 // parse phase and call n->Value() may return wrong type.
473 // (For example, a phi node at the beginning of loop parsing is not ready.)
474 const Type* t = type_or_null(n);
475 if (t == NULL) return NULL;
476 return t->isa_int();
477 }
480 //-------------------------------find_long_type--------------------------------
481 const TypeLong* PhaseTransform::find_long_type(Node* n) {
482 if (n == NULL) return NULL;
483 // (See comment above on type_or_null.)
484 const Type* t = type_or_null(n);
485 if (t == NULL) return NULL;
486 return t->isa_long();
487 }
490 #ifndef PRODUCT
491 void PhaseTransform::dump_old2new_map() const {
492 _nodes.dump();
493 }
495 void PhaseTransform::dump_new( uint nidx ) const {
496 for( uint i=0; i<_nodes.Size(); i++ )
497 if( _nodes[i] && _nodes[i]->_idx == nidx ) {
498 _nodes[i]->dump();
499 tty->cr();
500 tty->print_cr("Old index= %d",i);
501 return;
502 }
503 tty->print_cr("Node %d not found in the new indices", nidx);
504 }
506 //------------------------------dump_types-------------------------------------
507 void PhaseTransform::dump_types( ) const {
508 _types.dump();
509 }
511 //------------------------------dump_nodes_and_types---------------------------
512 void PhaseTransform::dump_nodes_and_types(const Node *root, uint depth, bool only_ctrl) {
513 VectorSet visited(Thread::current()->resource_area());
514 dump_nodes_and_types_recur( root, depth, only_ctrl, visited );
515 }
517 //------------------------------dump_nodes_and_types_recur---------------------
518 void PhaseTransform::dump_nodes_and_types_recur( const Node *n, uint depth, bool only_ctrl, VectorSet &visited) {
519 if( !n ) return;
520 if( depth == 0 ) return;
521 if( visited.test_set(n->_idx) ) return;
522 for( uint i=0; i<n->len(); i++ ) {
523 if( only_ctrl && !(n->is_Region()) && i != TypeFunc::Control ) continue;
524 dump_nodes_and_types_recur( n->in(i), depth-1, only_ctrl, visited );
525 }
526 n->dump();
527 if (type_or_null(n) != NULL) {
528 tty->print(" "); type(n)->dump(); tty->cr();
529 }
530 }
532 #endif
535 //=============================================================================
536 //------------------------------PhaseValues------------------------------------
537 // Set minimum table size to "255"
538 PhaseValues::PhaseValues( Arena *arena, uint est_max_size ) : PhaseTransform(arena, GVN), _table(arena, est_max_size) {
539 NOT_PRODUCT( clear_new_values(); )
540 }
542 //------------------------------PhaseValues------------------------------------
543 // Set minimum table size to "255"
544 PhaseValues::PhaseValues( PhaseValues *ptv ) : PhaseTransform( ptv, GVN ),
545 _table(&ptv->_table) {
546 NOT_PRODUCT( clear_new_values(); )
547 }
549 //------------------------------PhaseValues------------------------------------
550 // Used by +VerifyOpto. Clear out hash table but copy _types array.
551 PhaseValues::PhaseValues( PhaseValues *ptv, const char *dummy ) : PhaseTransform( ptv, GVN ),
552 _table(ptv->arena(),ptv->_table.size()) {
553 NOT_PRODUCT( clear_new_values(); )
554 }
556 //------------------------------~PhaseValues-----------------------------------
557 #ifndef PRODUCT
558 PhaseValues::~PhaseValues() {
559 _table.dump();
561 // Statistics for value progress and efficiency
562 if( PrintCompilation && Verbose && WizardMode ) {
563 tty->print("\n%sValues: %d nodes ---> %d/%d (%d)",
564 is_IterGVN() ? "Iter" : " ", C->unique(), made_progress(), made_transforms(), made_new_values());
565 if( made_transforms() != 0 ) {
566 tty->print_cr(" ratio %f", made_progress()/(float)made_transforms() );
567 } else {
568 tty->cr();
569 }
570 }
571 }
572 #endif
574 //------------------------------makecon----------------------------------------
575 ConNode* PhaseTransform::makecon(const Type *t) {
576 assert(t->singleton(), "must be a constant");
577 assert(!t->empty() || t == Type::TOP, "must not be vacuous range");
578 switch (t->base()) { // fast paths
579 case Type::Half:
580 case Type::Top: return (ConNode*) C->top();
581 case Type::Int: return intcon( t->is_int()->get_con() );
582 case Type::Long: return longcon( t->is_long()->get_con() );
583 }
584 if (t->is_zero_type())
585 return zerocon(t->basic_type());
586 return uncached_makecon(t);
587 }
589 //--------------------------uncached_makecon-----------------------------------
590 // Make an idealized constant - one of ConINode, ConPNode, etc.
591 ConNode* PhaseValues::uncached_makecon(const Type *t) {
592 assert(t->singleton(), "must be a constant");
593 ConNode* x = ConNode::make(C, t);
594 ConNode* k = (ConNode*)hash_find_insert(x); // Value numbering
595 if (k == NULL) {
596 set_type(x, t); // Missed, provide type mapping
597 GrowableArray<Node_Notes*>* nna = C->node_note_array();
598 if (nna != NULL) {
599 Node_Notes* loc = C->locate_node_notes(nna, x->_idx, true);
600 loc->clear(); // do not put debug info on constants
601 }
602 } else {
603 x->destruct(); // Hit, destroy duplicate constant
604 x = k; // use existing constant
605 }
606 return x;
607 }
609 //------------------------------intcon-----------------------------------------
610 // Fast integer constant. Same as "transform(new ConINode(TypeInt::make(i)))"
611 ConINode* PhaseTransform::intcon(int i) {
612 // Small integer? Check cache! Check that cached node is not dead
613 if (i >= _icon_min && i <= _icon_max) {
614 ConINode* icon = _icons[i-_icon_min];
615 if (icon != NULL && icon->in(TypeFunc::Control) != NULL)
616 return icon;
617 }
618 ConINode* icon = (ConINode*) uncached_makecon(TypeInt::make(i));
619 assert(icon->is_Con(), "");
620 if (i >= _icon_min && i <= _icon_max)
621 _icons[i-_icon_min] = icon; // Cache small integers
622 return icon;
623 }
625 //------------------------------longcon----------------------------------------
626 // Fast long constant.
627 ConLNode* PhaseTransform::longcon(jlong l) {
628 // Small integer? Check cache! Check that cached node is not dead
629 if (l >= _lcon_min && l <= _lcon_max) {
630 ConLNode* lcon = _lcons[l-_lcon_min];
631 if (lcon != NULL && lcon->in(TypeFunc::Control) != NULL)
632 return lcon;
633 }
634 ConLNode* lcon = (ConLNode*) uncached_makecon(TypeLong::make(l));
635 assert(lcon->is_Con(), "");
636 if (l >= _lcon_min && l <= _lcon_max)
637 _lcons[l-_lcon_min] = lcon; // Cache small integers
638 return lcon;
639 }
641 //------------------------------zerocon-----------------------------------------
642 // Fast zero or null constant. Same as "transform(ConNode::make(Type::get_zero_type(bt)))"
643 ConNode* PhaseTransform::zerocon(BasicType bt) {
644 assert((uint)bt <= _zcon_max, "domain check");
645 ConNode* zcon = _zcons[bt];
646 if (zcon != NULL && zcon->in(TypeFunc::Control) != NULL)
647 return zcon;
648 zcon = (ConNode*) uncached_makecon(Type::get_zero_type(bt));
649 _zcons[bt] = zcon;
650 return zcon;
651 }
655 //=============================================================================
656 //------------------------------transform--------------------------------------
657 // Return a node which computes the same function as this node, but in a
658 // faster or cheaper fashion.
659 Node *PhaseGVN::transform( Node *n ) {
660 return transform_no_reclaim(n);
661 }
663 //------------------------------transform--------------------------------------
664 // Return a node which computes the same function as this node, but
665 // in a faster or cheaper fashion.
666 Node *PhaseGVN::transform_no_reclaim( Node *n ) {
667 NOT_PRODUCT( set_transforms(); )
669 // Apply the Ideal call in a loop until it no longer applies
670 Node *k = n;
671 NOT_PRODUCT( uint loop_count = 0; )
672 while( 1 ) {
673 Node *i = k->Ideal(this, /*can_reshape=*/false);
674 if( !i ) break;
675 assert( i->_idx >= k->_idx, "Idealize should return new nodes, use Identity to return old nodes" );
676 k = i;
677 assert(loop_count++ < K, "infinite loop in PhaseGVN::transform");
678 }
679 NOT_PRODUCT( if( loop_count != 0 ) { set_progress(); } )
682 // If brand new node, make space in type array.
683 ensure_type_or_null(k);
685 // Since I just called 'Value' to compute the set of run-time values
686 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
687 // cache Value. Later requests for the local phase->type of this Node can
688 // use the cached Value instead of suffering with 'bottom_type'.
689 const Type *t = k->Value(this); // Get runtime Value set
690 assert(t != NULL, "value sanity");
691 if (type_or_null(k) != t) {
692 #ifndef PRODUCT
693 // Do not count initial visit to node as a transformation
694 if (type_or_null(k) == NULL) {
695 inc_new_values();
696 set_progress();
697 }
698 #endif
699 set_type(k, t);
700 // If k is a TypeNode, capture any more-precise type permanently into Node
701 k->raise_bottom_type(t);
702 }
704 if( t->singleton() && !k->is_Con() ) {
705 NOT_PRODUCT( set_progress(); )
706 return makecon(t); // Turn into a constant
707 }
709 // Now check for Identities
710 Node *i = k->Identity(this); // Look for a nearby replacement
711 if( i != k ) { // Found? Return replacement!
712 NOT_PRODUCT( set_progress(); )
713 return i;
714 }
716 // Global Value Numbering
717 i = hash_find_insert(k); // Insert if new
718 if( i && (i != k) ) {
719 // Return the pre-existing node
720 NOT_PRODUCT( set_progress(); )
721 return i;
722 }
724 // Return Idealized original
725 return k;
726 }
728 #ifdef ASSERT
729 //------------------------------dead_loop_check--------------------------------
730 // Check for a simple dead loop when a data node references itself directly
731 // or through an other data node excluding cons and phis.
732 void PhaseGVN::dead_loop_check( Node *n ) {
733 // Phi may reference itself in a loop
734 if (n != NULL && !n->is_dead_loop_safe() && !n->is_CFG()) {
735 // Do 2 levels check and only data inputs.
736 bool no_dead_loop = true;
737 uint cnt = n->req();
738 for (uint i = 1; i < cnt && no_dead_loop; i++) {
739 Node *in = n->in(i);
740 if (in == n) {
741 no_dead_loop = false;
742 } else if (in != NULL && !in->is_dead_loop_safe()) {
743 uint icnt = in->req();
744 for (uint j = 1; j < icnt && no_dead_loop; j++) {
745 if (in->in(j) == n || in->in(j) == in)
746 no_dead_loop = false;
747 }
748 }
749 }
750 if (!no_dead_loop) n->dump(3);
751 assert(no_dead_loop, "dead loop detected");
752 }
753 }
754 #endif
756 //=============================================================================
757 //------------------------------PhaseIterGVN-----------------------------------
758 // Initialize hash table to fresh and clean for +VerifyOpto
759 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn, const char *dummy ) : PhaseGVN(igvn,dummy), _worklist( ),
760 _delay_transform(false) {
761 }
763 //------------------------------PhaseIterGVN-----------------------------------
764 // Initialize with previous PhaseIterGVN info; used by PhaseCCP
765 PhaseIterGVN::PhaseIterGVN( PhaseIterGVN *igvn ) : PhaseGVN(igvn),
766 _worklist( igvn->_worklist ),
767 _delay_transform(igvn->_delay_transform)
768 {
769 }
771 //------------------------------PhaseIterGVN-----------------------------------
772 // Initialize with previous PhaseGVN info from Parser
773 PhaseIterGVN::PhaseIterGVN( PhaseGVN *gvn ) : PhaseGVN(gvn),
774 _worklist(*C->for_igvn()),
775 _delay_transform(false)
776 {
777 uint max;
779 // Dead nodes in the hash table inherited from GVN were not treated as
780 // roots during def-use info creation; hence they represent an invisible
781 // use. Clear them out.
782 max = _table.size();
783 for( uint i = 0; i < max; ++i ) {
784 Node *n = _table.at(i);
785 if(n != NULL && n != _table.sentinel() && n->outcnt() == 0) {
786 if( n->is_top() ) continue;
787 assert( false, "Parse::remove_useless_nodes missed this node");
788 hash_delete(n);
789 }
790 }
792 // Any Phis or Regions on the worklist probably had uses that could not
793 // make more progress because the uses were made while the Phis and Regions
794 // were in half-built states. Put all uses of Phis and Regions on worklist.
795 max = _worklist.size();
796 for( uint j = 0; j < max; j++ ) {
797 Node *n = _worklist.at(j);
798 uint uop = n->Opcode();
799 if( uop == Op_Phi || uop == Op_Region ||
800 n->is_Type() ||
801 n->is_Mem() )
802 add_users_to_worklist(n);
803 }
804 }
807 #ifndef PRODUCT
808 void PhaseIterGVN::verify_step(Node* n) {
809 _verify_window[_verify_counter % _verify_window_size] = n;
810 ++_verify_counter;
811 ResourceMark rm;
812 ResourceArea *area = Thread::current()->resource_area();
813 VectorSet old_space(area), new_space(area);
814 if (C->unique() < 1000 ||
815 0 == _verify_counter % (C->unique() < 10000 ? 10 : 100)) {
816 ++_verify_full_passes;
817 Node::verify_recur(C->root(), -1, old_space, new_space);
818 }
819 const int verify_depth = 4;
820 for ( int i = 0; i < _verify_window_size; i++ ) {
821 Node* n = _verify_window[i];
822 if ( n == NULL ) continue;
823 if( n->in(0) == NodeSentinel ) { // xform_idom
824 _verify_window[i] = n->in(1);
825 --i; continue;
826 }
827 // Typical fanout is 1-2, so this call visits about 6 nodes.
828 Node::verify_recur(n, verify_depth, old_space, new_space);
829 }
830 }
831 #endif
834 //------------------------------init_worklist----------------------------------
835 // Initialize worklist for each node.
836 void PhaseIterGVN::init_worklist( Node *n ) {
837 if( _worklist.member(n) ) return;
838 _worklist.push(n);
839 uint cnt = n->req();
840 for( uint i =0 ; i < cnt; i++ ) {
841 Node *m = n->in(i);
842 if( m ) init_worklist(m);
843 }
844 }
846 //------------------------------optimize---------------------------------------
847 void PhaseIterGVN::optimize() {
848 debug_only(uint num_processed = 0;);
849 #ifndef PRODUCT
850 {
851 _verify_counter = 0;
852 _verify_full_passes = 0;
853 for ( int i = 0; i < _verify_window_size; i++ ) {
854 _verify_window[i] = NULL;
855 }
856 }
857 #endif
859 #ifdef ASSERT
860 Node* prev = NULL;
861 uint rep_cnt = 0;
862 #endif
863 uint loop_count = 0;
865 // Pull from worklist; transform node;
866 // If node has changed: update edge info and put uses on worklist.
867 while( _worklist.size() ) {
868 if (C->check_node_count(NodeLimitFudgeFactor * 2,
869 "out of nodes optimizing method")) {
870 return;
871 }
872 Node *n = _worklist.pop();
873 if (++loop_count >= K * C->unique()) {
874 debug_only(n->dump(4);)
875 assert(false, "infinite loop in PhaseIterGVN::optimize");
876 C->record_method_not_compilable("infinite loop in PhaseIterGVN::optimize");
877 return;
878 }
879 #ifdef ASSERT
880 if (n == prev) {
881 if (++rep_cnt > 3) {
882 n->dump(4);
883 assert(false, "loop in Ideal transformation");
884 }
885 } else {
886 rep_cnt = 0;
887 }
888 prev = n;
889 #endif
890 if (TraceIterativeGVN && Verbose) {
891 tty->print(" Pop ");
892 NOT_PRODUCT( n->dump(); )
893 debug_only(if( (num_processed++ % 100) == 0 ) _worklist.print_set();)
894 }
896 if (n->outcnt() != 0) {
898 #ifndef PRODUCT
899 uint wlsize = _worklist.size();
900 const Type* oldtype = type_or_null(n);
901 #endif //PRODUCT
903 Node *nn = transform_old(n);
905 #ifndef PRODUCT
906 if (TraceIterativeGVN) {
907 const Type* newtype = type_or_null(n);
908 if (nn != n) {
909 // print old node
910 tty->print("< ");
911 if (oldtype != newtype && oldtype != NULL) {
912 oldtype->dump();
913 }
914 do { tty->print("\t"); } while (tty->position() < 16);
915 tty->print("<");
916 n->dump();
917 }
918 if (oldtype != newtype || nn != n) {
919 // print new node and/or new type
920 if (oldtype == NULL) {
921 tty->print("* ");
922 } else if (nn != n) {
923 tty->print("> ");
924 } else {
925 tty->print("= ");
926 }
927 if (newtype == NULL) {
928 tty->print("null");
929 } else {
930 newtype->dump();
931 }
932 do { tty->print("\t"); } while (tty->position() < 16);
933 nn->dump();
934 }
935 if (Verbose && wlsize < _worklist.size()) {
936 tty->print(" Push {");
937 while (wlsize != _worklist.size()) {
938 Node* pushed = _worklist.at(wlsize++);
939 tty->print(" %d", pushed->_idx);
940 }
941 tty->print_cr(" }");
942 }
943 }
944 if( VerifyIterativeGVN && nn != n ) {
945 verify_step((Node*) NULL); // ignore n, it might be subsumed
946 }
947 #endif
948 } else if (!n->is_top()) {
949 remove_dead_node(n);
950 }
951 }
953 #ifndef PRODUCT
954 C->verify_graph_edges();
955 if( VerifyOpto && allow_progress() ) {
956 // Must turn off allow_progress to enable assert and break recursion
957 C->root()->verify();
958 { // Check if any progress was missed using IterGVN
959 // Def-Use info enables transformations not attempted in wash-pass
960 // e.g. Region/Phi cleanup, ...
961 // Null-check elision -- may not have reached fixpoint
962 // do not propagate to dominated nodes
963 ResourceMark rm;
964 PhaseIterGVN igvn2(this,"Verify"); // Fresh and clean!
965 // Fill worklist completely
966 igvn2.init_worklist(C->root());
968 igvn2.set_allow_progress(false);
969 igvn2.optimize();
970 igvn2.set_allow_progress(true);
971 }
972 }
973 if ( VerifyIterativeGVN && PrintOpto ) {
974 if ( _verify_counter == _verify_full_passes )
975 tty->print_cr("VerifyIterativeGVN: %d transforms and verify passes",
976 _verify_full_passes);
977 else
978 tty->print_cr("VerifyIterativeGVN: %d transforms, %d full verify passes",
979 _verify_counter, _verify_full_passes);
980 }
981 #endif
982 }
985 //------------------register_new_node_with_optimizer---------------------------
986 // Register a new node with the optimizer. Update the types array, the def-use
987 // info. Put on worklist.
988 Node* PhaseIterGVN::register_new_node_with_optimizer(Node* n, Node* orig) {
989 set_type_bottom(n);
990 _worklist.push(n);
991 if (orig != NULL) C->copy_node_notes_to(n, orig);
992 return n;
993 }
995 //------------------------------transform--------------------------------------
996 // Non-recursive: idealize Node 'n' with respect to its inputs and its value
997 Node *PhaseIterGVN::transform( Node *n ) {
998 if (_delay_transform) {
999 // Register the node but don't optimize for now
1000 register_new_node_with_optimizer(n);
1001 return n;
1002 }
1004 // If brand new node, make space in type array, and give it a type.
1005 ensure_type_or_null(n);
1006 if (type_or_null(n) == NULL) {
1007 set_type_bottom(n);
1008 }
1010 return transform_old(n);
1011 }
1013 //------------------------------transform_old----------------------------------
1014 Node *PhaseIterGVN::transform_old( Node *n ) {
1015 #ifndef PRODUCT
1016 debug_only(uint loop_count = 0;);
1017 set_transforms();
1018 #endif
1019 // Remove 'n' from hash table in case it gets modified
1020 _table.hash_delete(n);
1021 if( VerifyIterativeGVN ) {
1022 assert( !_table.find_index(n->_idx), "found duplicate entry in table");
1023 }
1025 // Apply the Ideal call in a loop until it no longer applies
1026 Node *k = n;
1027 DEBUG_ONLY(dead_loop_check(k);)
1028 DEBUG_ONLY(bool is_new = (k->outcnt() == 0);)
1029 Node *i = k->Ideal(this, /*can_reshape=*/true);
1030 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1031 #ifndef PRODUCT
1032 if( VerifyIterativeGVN )
1033 verify_step(k);
1034 if( i && VerifyOpto ) {
1035 if( !allow_progress() ) {
1036 if (i->is_Add() && i->outcnt() == 1) {
1037 // Switched input to left side because this is the only use
1038 } else if( i->is_If() && (i->in(0) == NULL) ) {
1039 // This IF is dead because it is dominated by an equivalent IF When
1040 // dominating if changed, info is not propagated sparsely to 'this'
1041 // Propagating this info further will spuriously identify other
1042 // progress.
1043 return i;
1044 } else
1045 set_progress();
1046 } else
1047 set_progress();
1048 }
1049 #endif
1051 while( i ) {
1052 #ifndef PRODUCT
1053 debug_only( if( loop_count >= K ) i->dump(4); )
1054 assert(loop_count < K, "infinite loop in PhaseIterGVN::transform");
1055 debug_only( loop_count++; )
1056 #endif
1057 assert((i->_idx >= k->_idx) || i->is_top(), "Idealize should return new nodes, use Identity to return old nodes");
1058 // Made a change; put users of original Node on worklist
1059 add_users_to_worklist( k );
1060 // Replacing root of transform tree?
1061 if( k != i ) {
1062 // Make users of old Node now use new.
1063 subsume_node( k, i );
1064 k = i;
1065 }
1066 DEBUG_ONLY(dead_loop_check(k);)
1067 // Try idealizing again
1068 DEBUG_ONLY(is_new = (k->outcnt() == 0);)
1069 i = k->Ideal(this, /*can_reshape=*/true);
1070 assert(i != k || is_new || i->outcnt() > 0, "don't return dead nodes");
1071 #ifndef PRODUCT
1072 if( VerifyIterativeGVN )
1073 verify_step(k);
1074 if( i && VerifyOpto ) set_progress();
1075 #endif
1076 }
1078 // If brand new node, make space in type array.
1079 ensure_type_or_null(k);
1081 // See what kind of values 'k' takes on at runtime
1082 const Type *t = k->Value(this);
1083 assert(t != NULL, "value sanity");
1085 // Since I just called 'Value' to compute the set of run-time values
1086 // for this Node, and 'Value' is non-local (and therefore expensive) I'll
1087 // cache Value. Later requests for the local phase->type of this Node can
1088 // use the cached Value instead of suffering with 'bottom_type'.
1089 if (t != type_or_null(k)) {
1090 NOT_PRODUCT( set_progress(); )
1091 NOT_PRODUCT( inc_new_values();)
1092 set_type(k, t);
1093 // If k is a TypeNode, capture any more-precise type permanently into Node
1094 k->raise_bottom_type(t);
1095 // Move users of node to worklist
1096 add_users_to_worklist( k );
1097 }
1099 // If 'k' computes a constant, replace it with a constant
1100 if( t->singleton() && !k->is_Con() ) {
1101 NOT_PRODUCT( set_progress(); )
1102 Node *con = makecon(t); // Make a constant
1103 add_users_to_worklist( k );
1104 subsume_node( k, con ); // Everybody using k now uses con
1105 return con;
1106 }
1108 // Now check for Identities
1109 i = k->Identity(this); // Look for a nearby replacement
1110 if( i != k ) { // Found? Return replacement!
1111 NOT_PRODUCT( set_progress(); )
1112 add_users_to_worklist( k );
1113 subsume_node( k, i ); // Everybody using k now uses i
1114 return i;
1115 }
1117 // Global Value Numbering
1118 i = hash_find_insert(k); // Check for pre-existing node
1119 if( i && (i != k) ) {
1120 // Return the pre-existing node if it isn't dead
1121 NOT_PRODUCT( set_progress(); )
1122 add_users_to_worklist( k );
1123 subsume_node( k, i ); // Everybody using k now uses i
1124 return i;
1125 }
1127 // Return Idealized original
1128 return k;
1129 }
1131 //---------------------------------saturate------------------------------------
1132 const Type* PhaseIterGVN::saturate(const Type* new_type, const Type* old_type,
1133 const Type* limit_type) const {
1134 return new_type->narrow(old_type);
1135 }
1137 //------------------------------remove_globally_dead_node----------------------
1138 // Kill a globally dead Node. All uses are also globally dead and are
1139 // aggressively trimmed.
1140 void PhaseIterGVN::remove_globally_dead_node( Node *dead ) {
1141 assert(dead != C->root(), "killing root, eh?");
1142 if (dead->is_top()) return;
1143 NOT_PRODUCT( set_progress(); )
1144 // Remove from iterative worklist
1145 _worklist.remove(dead);
1146 if (!dead->is_Con()) { // Don't kill cons but uses
1147 // Remove from hash table
1148 _table.hash_delete( dead );
1149 // Smash all inputs to 'dead', isolating him completely
1150 for( uint i = 0; i < dead->req(); i++ ) {
1151 Node *in = dead->in(i);
1152 if( in ) { // Points to something?
1153 dead->set_req(i,NULL); // Kill the edge
1154 if (in->outcnt() == 0 && in != C->top()) {// Made input go dead?
1155 remove_dead_node(in); // Recursively remove
1156 } else if (in->outcnt() == 1 &&
1157 in->has_special_unique_user()) {
1158 _worklist.push(in->unique_out());
1159 } else if (in->outcnt() <= 2 && dead->is_Phi()) {
1160 if( in->Opcode() == Op_Region )
1161 _worklist.push(in);
1162 else if( in->is_Store() ) {
1163 DUIterator_Fast imax, i = in->fast_outs(imax);
1164 _worklist.push(in->fast_out(i));
1165 i++;
1166 if(in->outcnt() == 2) {
1167 _worklist.push(in->fast_out(i));
1168 i++;
1169 }
1170 assert(!(i < imax), "sanity");
1171 }
1172 }
1173 }
1174 }
1176 if (dead->is_macro()) {
1177 C->remove_macro_node(dead);
1178 }
1179 }
1180 // Aggressively kill globally dead uses
1181 // (Cannot use DUIterator_Last because of the indefinite number
1182 // of edge deletions per loop trip.)
1183 while (dead->outcnt() > 0) {
1184 remove_globally_dead_node(dead->raw_out(0));
1185 }
1186 }
1188 //------------------------------subsume_node-----------------------------------
1189 // Remove users from node 'old' and add them to node 'nn'.
1190 void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
1191 assert( old != hash_find(old), "should already been removed" );
1192 assert( old != C->top(), "cannot subsume top node");
1193 // Copy debug or profile information to the new version:
1194 C->copy_node_notes_to(nn, old);
1195 // Move users of node 'old' to node 'nn'
1196 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin; ) {
1197 Node* use = old->last_out(i); // for each use...
1198 // use might need re-hashing (but it won't if it's a new node)
1199 bool is_in_table = _table.hash_delete( use );
1200 // Update use-def info as well
1201 // We remove all occurrences of old within use->in,
1202 // so as to avoid rehashing any node more than once.
1203 // The hash table probe swamps any outer loop overhead.
1204 uint num_edges = 0;
1205 for (uint jmax = use->len(), j = 0; j < jmax; j++) {
1206 if (use->in(j) == old) {
1207 use->set_req(j, nn);
1208 ++num_edges;
1209 }
1210 }
1211 // Insert into GVN hash table if unique
1212 // If a duplicate, 'use' will be cleaned up when pulled off worklist
1213 if( is_in_table ) {
1214 hash_find_insert(use);
1215 }
1216 i -= num_edges; // we deleted 1 or more copies of this edge
1217 }
1219 // Smash all inputs to 'old', isolating him completely
1220 Node *temp = new (C, 1) Node(1);
1221 temp->init_req(0,nn); // Add a use to nn to prevent him from dying
1222 remove_dead_node( old );
1223 temp->del_req(0); // Yank bogus edge
1224 #ifndef PRODUCT
1225 if( VerifyIterativeGVN ) {
1226 for ( int i = 0; i < _verify_window_size; i++ ) {
1227 if ( _verify_window[i] == old )
1228 _verify_window[i] = nn;
1229 }
1230 }
1231 #endif
1232 _worklist.remove(temp); // this can be necessary
1233 temp->destruct(); // reuse the _idx of this little guy
1234 }
1236 //------------------------------add_users_to_worklist--------------------------
1237 void PhaseIterGVN::add_users_to_worklist0( Node *n ) {
1238 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1239 _worklist.push(n->fast_out(i)); // Push on worklist
1240 }
1241 }
1243 void PhaseIterGVN::add_users_to_worklist( Node *n ) {
1244 add_users_to_worklist0(n);
1246 // Move users of node to worklist
1247 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1248 Node* use = n->fast_out(i); // Get use
1250 if( use->is_Multi() || // Multi-definer? Push projs on worklist
1251 use->is_Store() ) // Enable store/load same address
1252 add_users_to_worklist0(use);
1254 // If we changed the receiver type to a call, we need to revisit
1255 // the Catch following the call. It's looking for a non-NULL
1256 // receiver to know when to enable the regular fall-through path
1257 // in addition to the NullPtrException path.
1258 if (use->is_CallDynamicJava() && n == use->in(TypeFunc::Parms)) {
1259 Node* p = use->as_CallDynamicJava()->proj_out(TypeFunc::Control);
1260 if (p != NULL) {
1261 add_users_to_worklist0(p);
1262 }
1263 }
1265 if( use->is_Cmp() ) { // Enable CMP/BOOL optimization
1266 add_users_to_worklist(use); // Put Bool on worklist
1267 // Look for the 'is_x2logic' pattern: "x ? : 0 : 1" and put the
1268 // phi merging either 0 or 1 onto the worklist
1269 if (use->outcnt() > 0) {
1270 Node* bol = use->raw_out(0);
1271 if (bol->outcnt() > 0) {
1272 Node* iff = bol->raw_out(0);
1273 if (iff->outcnt() == 2) {
1274 Node* ifproj0 = iff->raw_out(0);
1275 Node* ifproj1 = iff->raw_out(1);
1276 if (ifproj0->outcnt() > 0 && ifproj1->outcnt() > 0) {
1277 Node* region0 = ifproj0->raw_out(0);
1278 Node* region1 = ifproj1->raw_out(0);
1279 if( region0 == region1 )
1280 add_users_to_worklist0(region0);
1281 }
1282 }
1283 }
1284 }
1285 }
1287 uint use_op = use->Opcode();
1288 // If changed Cast input, check Phi users for simple cycles
1289 if( use->is_ConstraintCast() || use->is_CheckCastPP() ) {
1290 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1291 Node* u = use->fast_out(i2);
1292 if (u->is_Phi())
1293 _worklist.push(u);
1294 }
1295 }
1296 // If changed LShift inputs, check RShift users for useless sign-ext
1297 if( use_op == Op_LShiftI ) {
1298 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1299 Node* u = use->fast_out(i2);
1300 if (u->Opcode() == Op_RShiftI)
1301 _worklist.push(u);
1302 }
1303 }
1304 // If changed AddP inputs, check Stores for loop invariant
1305 if( use_op == Op_AddP ) {
1306 for (DUIterator_Fast i2max, i2 = use->fast_outs(i2max); i2 < i2max; i2++) {
1307 Node* u = use->fast_out(i2);
1308 if (u->is_Mem())
1309 _worklist.push(u);
1310 }
1311 }
1312 // If changed initialization activity, check dependent Stores
1313 if (use_op == Op_Allocate || use_op == Op_AllocateArray) {
1314 InitializeNode* init = use->as_Allocate()->initialization();
1315 if (init != NULL) {
1316 Node* imem = init->proj_out(TypeFunc::Memory);
1317 if (imem != NULL) add_users_to_worklist0(imem);
1318 }
1319 }
1320 if (use_op == Op_Initialize) {
1321 Node* imem = use->as_Initialize()->proj_out(TypeFunc::Memory);
1322 if (imem != NULL) add_users_to_worklist0(imem);
1323 }
1324 }
1325 }
1327 //=============================================================================
1328 #ifndef PRODUCT
1329 uint PhaseCCP::_total_invokes = 0;
1330 uint PhaseCCP::_total_constants = 0;
1331 #endif
1332 //------------------------------PhaseCCP---------------------------------------
1333 // Conditional Constant Propagation, ala Wegman & Zadeck
1334 PhaseCCP::PhaseCCP( PhaseIterGVN *igvn ) : PhaseIterGVN(igvn) {
1335 NOT_PRODUCT( clear_constants(); )
1336 assert( _worklist.size() == 0, "" );
1337 // Clear out _nodes from IterGVN. Must be clear to transform call.
1338 _nodes.clear(); // Clear out from IterGVN
1339 analyze();
1340 }
1342 #ifndef PRODUCT
1343 //------------------------------~PhaseCCP--------------------------------------
1344 PhaseCCP::~PhaseCCP() {
1345 inc_invokes();
1346 _total_constants += count_constants();
1347 }
1348 #endif
1351 #ifdef ASSERT
1352 static bool ccp_type_widens(const Type* t, const Type* t0) {
1353 assert(t->meet(t0) == t, "Not monotonic");
1354 switch (t->base() == t0->base() ? t->base() : Type::Top) {
1355 case Type::Int:
1356 assert(t0->isa_int()->_widen <= t->isa_int()->_widen, "widen increases");
1357 break;
1358 case Type::Long:
1359 assert(t0->isa_long()->_widen <= t->isa_long()->_widen, "widen increases");
1360 break;
1361 }
1362 return true;
1363 }
1364 #endif //ASSERT
1366 //------------------------------analyze----------------------------------------
1367 void PhaseCCP::analyze() {
1368 // Initialize all types to TOP, optimistic analysis
1369 for (int i = C->unique() - 1; i >= 0; i--) {
1370 _types.map(i,Type::TOP);
1371 }
1373 // Push root onto worklist
1374 Unique_Node_List worklist;
1375 worklist.push(C->root());
1377 // Pull from worklist; compute new value; push changes out.
1378 // This loop is the meat of CCP.
1379 while( worklist.size() ) {
1380 Node *n = worklist.pop();
1381 const Type *t = n->Value(this);
1382 if (t != type(n)) {
1383 assert(ccp_type_widens(t, type(n)), "ccp type must widen");
1384 #ifndef PRODUCT
1385 if( TracePhaseCCP ) {
1386 t->dump();
1387 do { tty->print("\t"); } while (tty->position() < 16);
1388 n->dump();
1389 }
1390 #endif
1391 set_type(n, t);
1392 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1393 Node* m = n->fast_out(i); // Get user
1394 if( m->is_Region() ) { // New path to Region? Must recheck Phis too
1395 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1396 Node* p = m->fast_out(i2); // Propagate changes to uses
1397 if( p->bottom_type() != type(p) ) // If not already bottomed out
1398 worklist.push(p); // Propagate change to user
1399 }
1400 }
1401 // If we changed the receiver type to a call, we need to revisit
1402 // the Catch following the call. It's looking for a non-NULL
1403 // receiver to know when to enable the regular fall-through path
1404 // in addition to the NullPtrException path
1405 if (m->is_Call()) {
1406 for (DUIterator_Fast i2max, i2 = m->fast_outs(i2max); i2 < i2max; i2++) {
1407 Node* p = m->fast_out(i2); // Propagate changes to uses
1408 if (p->is_Proj() && p->as_Proj()->_con == TypeFunc::Control && p->outcnt() == 1)
1409 worklist.push(p->unique_out());
1410 }
1411 }
1412 if( m->bottom_type() != type(m) ) // If not already bottomed out
1413 worklist.push(m); // Propagate change to user
1414 }
1415 }
1416 }
1417 }
1419 //------------------------------do_transform-----------------------------------
1420 // Top level driver for the recursive transformer
1421 void PhaseCCP::do_transform() {
1422 // Correct leaves of new-space Nodes; they point to old-space.
1423 C->set_root( transform(C->root())->as_Root() );
1424 assert( C->top(), "missing TOP node" );
1425 assert( C->root(), "missing root" );
1426 }
1428 //------------------------------transform--------------------------------------
1429 // Given a Node in old-space, clone him into new-space.
1430 // Convert any of his old-space children into new-space children.
1431 Node *PhaseCCP::transform( Node *n ) {
1432 Node *new_node = _nodes[n->_idx]; // Check for transformed node
1433 if( new_node != NULL )
1434 return new_node; // Been there, done that, return old answer
1435 new_node = transform_once(n); // Check for constant
1436 _nodes.map( n->_idx, new_node ); // Flag as having been cloned
1438 // Allocate stack of size _nodes.Size()/2 to avoid frequent realloc
1439 GrowableArray <Node *> trstack(C->unique() >> 1);
1441 trstack.push(new_node); // Process children of cloned node
1442 while ( trstack.is_nonempty() ) {
1443 Node *clone = trstack.pop();
1444 uint cnt = clone->req();
1445 for( uint i = 0; i < cnt; i++ ) { // For all inputs do
1446 Node *input = clone->in(i);
1447 if( input != NULL ) { // Ignore NULLs
1448 Node *new_input = _nodes[input->_idx]; // Check for cloned input node
1449 if( new_input == NULL ) {
1450 new_input = transform_once(input); // Check for constant
1451 _nodes.map( input->_idx, new_input );// Flag as having been cloned
1452 trstack.push(new_input);
1453 }
1454 assert( new_input == clone->in(i), "insanity check");
1455 }
1456 }
1457 }
1458 return new_node;
1459 }
1462 //------------------------------transform_once---------------------------------
1463 // For PhaseCCP, transformation is IDENTITY unless Node computed a constant.
1464 Node *PhaseCCP::transform_once( Node *n ) {
1465 const Type *t = type(n);
1466 // Constant? Use constant Node instead
1467 if( t->singleton() ) {
1468 Node *nn = n; // Default is to return the original constant
1469 if( t == Type::TOP ) {
1470 // cache my top node on the Compile instance
1471 if( C->cached_top_node() == NULL || C->cached_top_node()->in(0) == NULL ) {
1472 C->set_cached_top_node( ConNode::make(C, Type::TOP) );
1473 set_type(C->top(), Type::TOP);
1474 }
1475 nn = C->top();
1476 }
1477 if( !n->is_Con() ) {
1478 if( t != Type::TOP ) {
1479 nn = makecon(t); // ConNode::make(t);
1480 NOT_PRODUCT( inc_constants(); )
1481 } else if( n->is_Region() ) { // Unreachable region
1482 // Note: nn == C->top()
1483 n->set_req(0, NULL); // Cut selfreference
1484 // Eagerly remove dead phis to avoid phis copies creation.
1485 for (DUIterator i = n->outs(); n->has_out(i); i++) {
1486 Node* m = n->out(i);
1487 if( m->is_Phi() ) {
1488 assert(type(m) == Type::TOP, "Unreachable region should not have live phis.");
1489 replace_node(m, nn);
1490 --i; // deleted this phi; rescan starting with next position
1491 }
1492 }
1493 }
1494 replace_node(n,nn); // Update DefUse edges for new constant
1495 }
1496 return nn;
1497 }
1499 // If x is a TypeNode, capture any more-precise type permanently into Node
1500 if (t != n->bottom_type()) {
1501 hash_delete(n); // changing bottom type may force a rehash
1502 n->raise_bottom_type(t);
1503 _worklist.push(n); // n re-enters the hash table via the worklist
1504 }
1506 // Idealize graph using DU info. Must clone() into new-space.
1507 // DU info is generally used to show profitability, progress or safety
1508 // (but generally not needed for correctness).
1509 Node *nn = n->Ideal_DU_postCCP(this);
1511 // TEMPORARY fix to ensure that 2nd GVN pass eliminates NULL checks
1512 switch( n->Opcode() ) {
1513 case Op_FastLock: // Revisit FastLocks for lock coarsening
1514 case Op_If:
1515 case Op_CountedLoopEnd:
1516 case Op_Region:
1517 case Op_Loop:
1518 case Op_CountedLoop:
1519 case Op_Conv2B:
1520 case Op_Opaque1:
1521 case Op_Opaque2:
1522 _worklist.push(n);
1523 break;
1524 default:
1525 break;
1526 }
1527 if( nn ) {
1528 _worklist.push(n);
1529 // Put users of 'n' onto worklist for second igvn transform
1530 add_users_to_worklist(n);
1531 return nn;
1532 }
1534 return n;
1535 }
1537 //---------------------------------saturate------------------------------------
1538 const Type* PhaseCCP::saturate(const Type* new_type, const Type* old_type,
1539 const Type* limit_type) const {
1540 const Type* wide_type = new_type->widen(old_type, limit_type);
1541 if (wide_type != new_type) { // did we widen?
1542 // If so, we may have widened beyond the limit type. Clip it back down.
1543 new_type = wide_type->filter(limit_type);
1544 }
1545 return new_type;
1546 }
1548 //------------------------------print_statistics-------------------------------
1549 #ifndef PRODUCT
1550 void PhaseCCP::print_statistics() {
1551 tty->print_cr("CCP: %d constants found: %d", _total_invokes, _total_constants);
1552 }
1553 #endif
1556 //=============================================================================
1557 #ifndef PRODUCT
1558 uint PhasePeephole::_total_peepholes = 0;
1559 #endif
1560 //------------------------------PhasePeephole----------------------------------
1561 // Conditional Constant Propagation, ala Wegman & Zadeck
1562 PhasePeephole::PhasePeephole( PhaseRegAlloc *regalloc, PhaseCFG &cfg )
1563 : PhaseTransform(Peephole), _regalloc(regalloc), _cfg(cfg) {
1564 NOT_PRODUCT( clear_peepholes(); )
1565 }
1567 #ifndef PRODUCT
1568 //------------------------------~PhasePeephole---------------------------------
1569 PhasePeephole::~PhasePeephole() {
1570 _total_peepholes += count_peepholes();
1571 }
1572 #endif
1574 //------------------------------transform--------------------------------------
1575 Node *PhasePeephole::transform( Node *n ) {
1576 ShouldNotCallThis();
1577 return NULL;
1578 }
1580 //------------------------------do_transform-----------------------------------
1581 void PhasePeephole::do_transform() {
1582 bool method_name_not_printed = true;
1584 // Examine each basic block
1585 for( uint block_number = 1; block_number < _cfg._num_blocks; ++block_number ) {
1586 Block *block = _cfg._blocks[block_number];
1587 bool block_not_printed = true;
1589 // and each instruction within a block
1590 uint end_index = block->_nodes.size();
1591 // block->end_idx() not valid after PhaseRegAlloc
1592 for( uint instruction_index = 1; instruction_index < end_index; ++instruction_index ) {
1593 Node *n = block->_nodes.at(instruction_index);
1594 if( n->is_Mach() ) {
1595 MachNode *m = n->as_Mach();
1596 int deleted_count = 0;
1597 // check for peephole opportunities
1598 MachNode *m2 = m->peephole( block, instruction_index, _regalloc, deleted_count, C );
1599 if( m2 != NULL ) {
1600 #ifndef PRODUCT
1601 if( PrintOptoPeephole ) {
1602 // Print method, first time only
1603 if( C->method() && method_name_not_printed ) {
1604 C->method()->print_short_name(); tty->cr();
1605 method_name_not_printed = false;
1606 }
1607 // Print this block
1608 if( Verbose && block_not_printed) {
1609 tty->print_cr("in block");
1610 block->dump();
1611 block_not_printed = false;
1612 }
1613 // Print instructions being deleted
1614 for( int i = (deleted_count - 1); i >= 0; --i ) {
1615 block->_nodes.at(instruction_index-i)->as_Mach()->format(_regalloc); tty->cr();
1616 }
1617 tty->print_cr("replaced with");
1618 // Print new instruction
1619 m2->format(_regalloc);
1620 tty->print("\n\n");
1621 }
1622 #endif
1623 // Remove old nodes from basic block and update instruction_index
1624 // (old nodes still exist and may have edges pointing to them
1625 // as register allocation info is stored in the allocator using
1626 // the node index to live range mappings.)
1627 uint safe_instruction_index = (instruction_index - deleted_count);
1628 for( ; (instruction_index > safe_instruction_index); --instruction_index ) {
1629 block->_nodes.remove( instruction_index );
1630 }
1631 // install new node after safe_instruction_index
1632 block->_nodes.insert( safe_instruction_index + 1, m2 );
1633 end_index = block->_nodes.size() - 1; // Recompute new block size
1634 NOT_PRODUCT( inc_peepholes(); )
1635 }
1636 }
1637 }
1638 }
1639 }
1641 //------------------------------print_statistics-------------------------------
1642 #ifndef PRODUCT
1643 void PhasePeephole::print_statistics() {
1644 tty->print_cr("Peephole: peephole rules applied: %d", _total_peepholes);
1645 }
1646 #endif
1649 //=============================================================================
1650 //------------------------------set_req_X--------------------------------------
1651 void Node::set_req_X( uint i, Node *n, PhaseIterGVN *igvn ) {
1652 assert( is_not_dead(n), "can not use dead node");
1653 assert( igvn->hash_find(this) != this, "Need to remove from hash before changing edges" );
1654 Node *old = in(i);
1655 set_req(i, n);
1657 // old goes dead?
1658 if( old ) {
1659 switch (old->outcnt()) {
1660 case 0:
1661 // Put into the worklist to kill later. We do not kill it now because the
1662 // recursive kill will delete the current node (this) if dead-loop exists
1663 if (!old->is_top())
1664 igvn->_worklist.push( old );
1665 break;
1666 case 1:
1667 if( old->is_Store() || old->has_special_unique_user() )
1668 igvn->add_users_to_worklist( old );
1669 break;
1670 case 2:
1671 if( old->is_Store() )
1672 igvn->add_users_to_worklist( old );
1673 if( old->Opcode() == Op_Region )
1674 igvn->_worklist.push(old);
1675 break;
1676 case 3:
1677 if( old->Opcode() == Op_Region ) {
1678 igvn->_worklist.push(old);
1679 igvn->add_users_to_worklist( old );
1680 }
1681 break;
1682 default:
1683 break;
1684 }
1685 }
1687 }
1689 //-------------------------------replace_by-----------------------------------
1690 // Using def-use info, replace one node for another. Follow the def-use info
1691 // to all users of the OLD node. Then make all uses point to the NEW node.
1692 void Node::replace_by(Node *new_node) {
1693 assert(!is_top(), "top node has no DU info");
1694 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; ) {
1695 Node* use = last_out(i);
1696 uint uses_found = 0;
1697 for (uint j = 0; j < use->len(); j++) {
1698 if (use->in(j) == this) {
1699 if (j < use->req())
1700 use->set_req(j, new_node);
1701 else use->set_prec(j, new_node);
1702 uses_found++;
1703 }
1704 }
1705 i -= uses_found; // we deleted 1 or more copies of this edge
1706 }
1707 }
1709 //=============================================================================
1710 //-----------------------------------------------------------------------------
1711 void Type_Array::grow( uint i ) {
1712 if( !_max ) {
1713 _max = 1;
1714 _types = (const Type**)_a->Amalloc( _max * sizeof(Type*) );
1715 _types[0] = NULL;
1716 }
1717 uint old = _max;
1718 while( i >= _max ) _max <<= 1; // Double to fit
1719 _types = (const Type**)_a->Arealloc( _types, old*sizeof(Type*),_max*sizeof(Type*));
1720 memset( &_types[old], 0, (_max-old)*sizeof(Type*) );
1721 }
1723 //------------------------------dump-------------------------------------------
1724 #ifndef PRODUCT
1725 void Type_Array::dump() const {
1726 uint max = Size();
1727 for( uint i = 0; i < max; i++ ) {
1728 if( _types[i] != NULL ) {
1729 tty->print(" %d\t== ", i); _types[i]->dump(); tty->cr();
1730 }
1731 }
1732 }
1733 #endif
