1 /*
2 * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_node.cpp.incl"
27
28 class RegMask;
29 // #include "phase.hpp"
30 class PhaseTransform;
31 class PhaseGVN;
32
33 // Arena we are currently building Nodes in
34 const uint Node::NotAMachineReg = 0xffff0000;
35
36 #ifndef PRODUCT
37 extern int nodes_created;
38 #endif
39
40 #ifdef ASSERT
41
42 //-------------------------- construct_node------------------------------------
43 // Set a breakpoint here to identify where a particular node index is built.
44 void Node::verify_construction() {
45 _debug_orig = NULL;
46 int old_debug_idx = Compile::debug_idx();
47 int new_debug_idx = old_debug_idx+1;
48 if (new_debug_idx > 0) {
49 // Arrange that the lowest five decimal digits of _debug_idx
50 // will repeat thos of _idx. In case this is somehow pathological,
51 // we continue to assign negative numbers (!) consecutively.
52 const int mod = 100000;
53 int bump = (int)(_idx - new_debug_idx) % mod;
54 if (bump < 0) bump += mod;
55 assert(bump >= 0 && bump < mod, "");
56 new_debug_idx += bump;
57 }
58 Compile::set_debug_idx(new_debug_idx);
59 set_debug_idx( new_debug_idx );
60 assert(Compile::current()->unique() < (uint)MaxNodeLimit, "Node limit exceeded");
61 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
62 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
63 BREAKPOINT;
64 }
65 #if OPTO_DU_ITERATOR_ASSERT
66 _last_del = NULL;
67 _del_tick = 0;
68 #endif
69 _hash_lock = 0;
70 }
71
72
73 // #ifdef ASSERT ...
74
75 #if OPTO_DU_ITERATOR_ASSERT
76 void DUIterator_Common::sample(const Node* node) {
77 _vdui = VerifyDUIterators;
78 _node = node;
79 _outcnt = node->_outcnt;
80 _del_tick = node->_del_tick;
81 _last = NULL;
82 }
83
84 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
85 assert(_node == node, "consistent iterator source");
86 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
87 }
88
89 void DUIterator_Common::verify_resync() {
90 // Ensure that the loop body has just deleted the last guy produced.
91 const Node* node = _node;
92 // Ensure that at least one copy of the last-seen edge was deleted.
93 // Note: It is OK to delete multiple copies of the last-seen edge.
94 // Unfortunately, we have no way to verify that all the deletions delete
95 // that same edge. On this point we must use the Honor System.
96 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
97 assert(node->_last_del == _last, "must have deleted the edge just produced");
98 // We liked this deletion, so accept the resulting outcnt and tick.
99 _outcnt = node->_outcnt;
100 _del_tick = node->_del_tick;
101 }
102
103 void DUIterator_Common::reset(const DUIterator_Common& that) {
104 if (this == &that) return; // ignore assignment to self
105 if (!_vdui) {
106 // We need to initialize everything, overwriting garbage values.
107 _last = that._last;
108 _vdui = that._vdui;
109 }
110 // Note: It is legal (though odd) for an iterator over some node x
111 // to be reassigned to iterate over another node y. Some doubly-nested
112 // progress loops depend on being able to do this.
113 const Node* node = that._node;
114 // Re-initialize everything, except _last.
115 _node = node;
116 _outcnt = node->_outcnt;
117 _del_tick = node->_del_tick;
118 }
119
120 void DUIterator::sample(const Node* node) {
121 DUIterator_Common::sample(node); // Initialize the assertion data.
122 _refresh_tick = 0; // No refreshes have happened, as yet.
123 }
124
125 void DUIterator::verify(const Node* node, bool at_end_ok) {
126 DUIterator_Common::verify(node, at_end_ok);
127 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
128 }
129
130 void DUIterator::verify_increment() {
131 if (_refresh_tick & 1) {
132 // We have refreshed the index during this loop.
133 // Fix up _idx to meet asserts.
134 if (_idx > _outcnt) _idx = _outcnt;
135 }
136 verify(_node, true);
137 }
138
139 void DUIterator::verify_resync() {
140 // Note: We do not assert on _outcnt, because insertions are OK here.
141 DUIterator_Common::verify_resync();
142 // Make sure we are still in sync, possibly with no more out-edges:
143 verify(_node, true);
144 }
145
146 void DUIterator::reset(const DUIterator& that) {
147 if (this == &that) return; // self assignment is always a no-op
148 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
149 assert(that._idx == 0, "assign only the result of Node::outs()");
150 assert(_idx == that._idx, "already assigned _idx");
151 if (!_vdui) {
152 // We need to initialize everything, overwriting garbage values.
153 sample(that._node);
154 } else {
155 DUIterator_Common::reset(that);
156 if (_refresh_tick & 1) {
157 _refresh_tick++; // Clear the "was refreshed" flag.
158 }
159 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
160 }
161 }
162
163 void DUIterator::refresh() {
164 DUIterator_Common::sample(_node); // Re-fetch assertion data.
165 _refresh_tick |= 1; // Set the "was refreshed" flag.
166 }
167
168 void DUIterator::verify_finish() {
169 // If the loop has killed the node, do not require it to re-run.
170 if (_node->_outcnt == 0) _refresh_tick &= ~1;
171 // If this assert triggers, it means that a loop used refresh_out_pos
172 // to re-synch an iteration index, but the loop did not correctly
173 // re-run itself, using a "while (progress)" construct.
174 // This iterator enforces the rule that you must keep trying the loop
175 // until it "runs clean" without any need for refreshing.
176 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
177 }
178
179
180 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
181 DUIterator_Common::verify(node, at_end_ok);
182 Node** out = node->_out;
183 uint cnt = node->_outcnt;
184 assert(cnt == _outcnt, "no insertions allowed");
185 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
186 // This last check is carefully designed to work for NO_OUT_ARRAY.
187 }
188
189 void DUIterator_Fast::verify_limit() {
190 const Node* node = _node;
191 verify(node, true);
192 assert(_outp == node->_out + node->_outcnt, "limit still correct");
193 }
194
195 void DUIterator_Fast::verify_resync() {
196 const Node* node = _node;
197 if (_outp == node->_out + _outcnt) {
198 // Note that the limit imax, not the pointer i, gets updated with the
199 // exact count of deletions. (For the pointer it's always "--i".)
200 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
201 // This is a limit pointer, with a name like "imax".
202 // Fudge the _last field so that the common assert will be happy.
203 _last = (Node*) node->_last_del;
204 DUIterator_Common::verify_resync();
205 } else {
206 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
207 // A normal internal pointer.
208 DUIterator_Common::verify_resync();
209 // Make sure we are still in sync, possibly with no more out-edges:
210 verify(node, true);
211 }
212 }
213
214 void DUIterator_Fast::verify_relimit(uint n) {
215 const Node* node = _node;
216 assert((int)n > 0, "use imax -= n only with a positive count");
217 // This must be a limit pointer, with a name like "imax".
218 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
219 // The reported number of deletions must match what the node saw.
220 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
221 // Fudge the _last field so that the common assert will be happy.
222 _last = (Node*) node->_last_del;
223 DUIterator_Common::verify_resync();
224 }
225
226 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
227 assert(_outp == that._outp, "already assigned _outp");
228 DUIterator_Common::reset(that);
229 }
230
231 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
232 // at_end_ok means the _outp is allowed to underflow by 1
233 _outp += at_end_ok;
234 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
235 _outp -= at_end_ok;
236 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
237 }
238
239 void DUIterator_Last::verify_limit() {
240 // Do not require the limit address to be resynched.
241 //verify(node, true);
242 assert(_outp == _node->_out, "limit still correct");
243 }
244
245 void DUIterator_Last::verify_step(uint num_edges) {
246 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
247 _outcnt -= num_edges;
248 _del_tick += num_edges;
249 // Make sure we are still in sync, possibly with no more out-edges:
250 const Node* node = _node;
251 verify(node, true);
252 assert(node->_last_del == _last, "must have deleted the edge just produced");
253 }
254
255 #endif //OPTO_DU_ITERATOR_ASSERT
256
257
258 #endif //ASSERT
259
260
261 // This constant used to initialize _out may be any non-null value.
262 // The value NULL is reserved for the top node only.
263 #define NO_OUT_ARRAY ((Node**)-1)
264
265 // This funny expression handshakes with Node::operator new
266 // to pull Compile::current out of the new node's _out field,
267 // and then calls a subroutine which manages most field
268 // initializations. The only one which is tricky is the
269 // _idx field, which is const, and so must be initialized
270 // by a return value, not an assignment.
271 //
272 // (Aren't you thankful that Java finals don't require so many tricks?)
273 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
274 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
275 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
276 #endif
277
278 // Out-of-line code from node constructors.
279 // Executed only when extra debug info. is being passed around.
280 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
281 C->set_node_notes_at(idx, nn);
282 }
283
284 // Shared initialization code.
285 inline int Node::Init(int req, Compile* C) {
286 assert(Compile::current() == C, "must use operator new(Compile*)");
287 int idx = C->next_unique();
288
289 // If there are default notes floating around, capture them:
290 Node_Notes* nn = C->default_node_notes();
291 if (nn != NULL) init_node_notes(C, idx, nn);
292
293 // Note: At this point, C is dead,
294 // and we begin to initialize the new Node.
295
296 _cnt = _max = req;
297 _outcnt = _outmax = 0;
298 _class_id = Class_Node;
299 _flags = 0;
300 _out = NO_OUT_ARRAY;
301 return idx;
302 }
303
304 //------------------------------Node-------------------------------------------
305 // Create a Node, with a given number of required edges.
306 Node::Node(uint req)
307 : _idx(IDX_INIT(req))
308 {
309 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
310 debug_only( verify_construction() );
311 NOT_PRODUCT(nodes_created++);
312 if (req == 0) {
313 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
314 _in = NULL;
315 } else {
316 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
317 Node** to = _in;
318 for(uint i = 0; i < req; i++) {
319 to[i] = NULL;
320 }
321 }
322 }
323
324 //------------------------------Node-------------------------------------------
325 Node::Node(Node *n0)
326 : _idx(IDX_INIT(1))
327 {
328 debug_only( verify_construction() );
329 NOT_PRODUCT(nodes_created++);
330 // Assert we allocated space for input array already
331 assert( _in[0] == this, "Must pass arg count to 'new'" );
332 assert( is_not_dead(n0), "can not use dead node");
333 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
334 }
335
336 //------------------------------Node-------------------------------------------
337 Node::Node(Node *n0, Node *n1)
338 : _idx(IDX_INIT(2))
339 {
340 debug_only( verify_construction() );
341 NOT_PRODUCT(nodes_created++);
342 // Assert we allocated space for input array already
343 assert( _in[1] == this, "Must pass arg count to 'new'" );
344 assert( is_not_dead(n0), "can not use dead node");
345 assert( is_not_dead(n1), "can not use dead node");
346 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
347 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
348 }
349
350 //------------------------------Node-------------------------------------------
351 Node::Node(Node *n0, Node *n1, Node *n2)
352 : _idx(IDX_INIT(3))
353 {
354 debug_only( verify_construction() );
355 NOT_PRODUCT(nodes_created++);
356 // Assert we allocated space for input array already
357 assert( _in[2] == this, "Must pass arg count to 'new'" );
358 assert( is_not_dead(n0), "can not use dead node");
359 assert( is_not_dead(n1), "can not use dead node");
360 assert( is_not_dead(n2), "can not use dead node");
361 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
362 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
363 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
364 }
365
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
368 : _idx(IDX_INIT(4))
369 {
370 debug_only( verify_construction() );
371 NOT_PRODUCT(nodes_created++);
372 // Assert we allocated space for input array already
373 assert( _in[3] == this, "Must pass arg count to 'new'" );
374 assert( is_not_dead(n0), "can not use dead node");
375 assert( is_not_dead(n1), "can not use dead node");
376 assert( is_not_dead(n2), "can not use dead node");
377 assert( is_not_dead(n3), "can not use dead node");
378 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
379 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
380 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
381 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
382 }
383
384 //------------------------------Node-------------------------------------------
385 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
386 : _idx(IDX_INIT(5))
387 {
388 debug_only( verify_construction() );
389 NOT_PRODUCT(nodes_created++);
390 // Assert we allocated space for input array already
391 assert( _in[4] == this, "Must pass arg count to 'new'" );
392 assert( is_not_dead(n0), "can not use dead node");
393 assert( is_not_dead(n1), "can not use dead node");
394 assert( is_not_dead(n2), "can not use dead node");
395 assert( is_not_dead(n3), "can not use dead node");
396 assert( is_not_dead(n4), "can not use dead node");
397 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
398 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
399 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
400 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
401 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
402 }
403
404 //------------------------------Node-------------------------------------------
405 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
406 Node *n4, Node *n5)
407 : _idx(IDX_INIT(6))
408 {
409 debug_only( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 // Assert we allocated space for input array already
412 assert( _in[5] == this, "Must pass arg count to 'new'" );
413 assert( is_not_dead(n0), "can not use dead node");
414 assert( is_not_dead(n1), "can not use dead node");
415 assert( is_not_dead(n2), "can not use dead node");
416 assert( is_not_dead(n3), "can not use dead node");
417 assert( is_not_dead(n4), "can not use dead node");
418 assert( is_not_dead(n5), "can not use dead node");
419 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
420 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
421 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
422 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
423 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
424 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
425 }
426
427 //------------------------------Node-------------------------------------------
428 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
429 Node *n4, Node *n5, Node *n6)
430 : _idx(IDX_INIT(7))
431 {
432 debug_only( verify_construction() );
433 NOT_PRODUCT(nodes_created++);
434 // Assert we allocated space for input array already
435 assert( _in[6] == this, "Must pass arg count to 'new'" );
436 assert( is_not_dead(n0), "can not use dead node");
437 assert( is_not_dead(n1), "can not use dead node");
438 assert( is_not_dead(n2), "can not use dead node");
439 assert( is_not_dead(n3), "can not use dead node");
440 assert( is_not_dead(n4), "can not use dead node");
441 assert( is_not_dead(n5), "can not use dead node");
442 assert( is_not_dead(n6), "can not use dead node");
443 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
444 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
445 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
446 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
447 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
448 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
449 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
450 }
451
452
453 //------------------------------clone------------------------------------------
454 // Clone a Node.
455 Node *Node::clone() const {
456 Compile *compile = Compile::current();
457 uint s = size_of(); // Size of inherited Node
458 Node *n = (Node*)compile->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
459 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
460 // Set the new input pointer array
461 n->_in = (Node**)(((char*)n)+s);
462 // Cannot share the old output pointer array, so kill it
463 n->_out = NO_OUT_ARRAY;
464 // And reset the counters to 0
465 n->_outcnt = 0;
466 n->_outmax = 0;
467 // Unlock this guy, since he is not in any hash table.
468 debug_only(n->_hash_lock = 0);
469 // Walk the old node's input list to duplicate its edges
470 uint i;
471 for( i = 0; i < len(); i++ ) {
472 Node *x = in(i);
473 n->_in[i] = x;
474 if (x != NULL) x->add_out(n);
475 }
476 if (is_macro())
477 compile->add_macro_node(n);
478
479 n->set_idx(compile->next_unique()); // Get new unique index as well
480 debug_only( n->verify_construction() );
481 NOT_PRODUCT(nodes_created++);
482 // Do not patch over the debug_idx of a clone, because it makes it
483 // impossible to break on the clone's moment of creation.
484 //debug_only( n->set_debug_idx( debug_idx() ) );
485
486 compile->copy_node_notes_to(n, (Node*) this);
487
488 // MachNode clone
489 uint nopnds;
490 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
491 MachNode *mach = n->as_Mach();
492 MachNode *mthis = this->as_Mach();
493 // Get address of _opnd_array.
494 // It should be the same offset since it is the clone of this node.
495 MachOper **from = mthis->_opnds;
496 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
497 pointer_delta((const void*)from,
498 (const void*)(&mthis->_opnds), 1));
499 mach->_opnds = to;
500 for ( uint i = 0; i < nopnds; ++i ) {
501 to[i] = from[i]->clone(compile);
502 }
503 }
504 // cloning CallNode may need to clone JVMState
505 if (n->is_Call()) {
506 CallNode *call = n->as_Call();
507 call->clone_jvms();
508 }
509 return n; // Return the clone
510 }
511
512 //---------------------------setup_is_top--------------------------------------
513 // Call this when changing the top node, to reassert the invariants
514 // required by Node::is_top. See Compile::set_cached_top_node.
515 void Node::setup_is_top() {
516 if (this == (Node*)Compile::current()->top()) {
517 // This node has just become top. Kill its out array.
518 _outcnt = _outmax = 0;
519 _out = NULL; // marker value for top
520 assert(is_top(), "must be top");
521 } else {
522 if (_out == NULL) _out = NO_OUT_ARRAY;
523 assert(!is_top(), "must not be top");
524 }
525 }
526
527
528 //------------------------------~Node------------------------------------------
529 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
530 extern int reclaim_idx ;
531 extern int reclaim_in ;
532 extern int reclaim_node;
533 void Node::destruct() {
534 // Eagerly reclaim unique Node numberings
535 Compile* compile = Compile::current();
536 if ((uint)_idx+1 == compile->unique()) {
537 compile->set_unique(compile->unique()-1);
538 #ifdef ASSERT
539 reclaim_idx++;
540 #endif
541 }
542 // Clear debug info:
543 Node_Notes* nn = compile->node_notes_at(_idx);
544 if (nn != NULL) nn->clear();
545 // Walk the input array, freeing the corresponding output edges
546 _cnt = _max; // forget req/prec distinction
547 uint i;
548 for( i = 0; i < _max; i++ ) {
549 set_req(i, NULL);
550 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
551 }
552 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
553 // See if the input array was allocated just prior to the object
554 int edge_size = _max*sizeof(void*);
555 int out_edge_size = _outmax*sizeof(void*);
556 char *edge_end = ((char*)_in) + edge_size;
557 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
558 char *out_edge_end = out_array + out_edge_size;
559 int node_size = size_of();
560
561 // Free the output edge array
562 if (out_edge_size > 0) {
563 #ifdef ASSERT
564 if( out_edge_end == compile->node_arena()->hwm() )
565 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
566 #endif
567 compile->node_arena()->Afree(out_array, out_edge_size);
568 }
569
570 // Free the input edge array and the node itself
571 if( edge_end == (char*)this ) {
572 #ifdef ASSERT
573 if( edge_end+node_size == compile->node_arena()->hwm() ) {
574 reclaim_in += edge_size;
575 reclaim_node+= node_size;
576 }
577 #else
578 // It was; free the input array and object all in one hit
579 compile->node_arena()->Afree(_in,edge_size+node_size);
580 #endif
581 } else {
582
583 // Free just the input array
584 #ifdef ASSERT
585 if( edge_end == compile->node_arena()->hwm() )
586 reclaim_in += edge_size;
587 #endif
588 compile->node_arena()->Afree(_in,edge_size);
589
590 // Free just the object
591 #ifdef ASSERT
592 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
593 reclaim_node+= node_size;
594 #else
595 compile->node_arena()->Afree(this,node_size);
596 #endif
597 }
598 if (is_macro()) {
599 compile->remove_macro_node(this);
600 }
601 #ifdef ASSERT
602 // We will not actually delete the storage, but we'll make the node unusable.
603 *(address*)this = badAddress; // smash the C++ vtbl, probably
604 _in = _out = (Node**) badAddress;
605 _max = _cnt = _outmax = _outcnt = 0;
606 #endif
607 }
608
609 //------------------------------grow-------------------------------------------
610 // Grow the input array, making space for more edges
611 void Node::grow( uint len ) {
612 Arena* arena = Compile::current()->node_arena();
613 uint new_max = _max;
614 if( new_max == 0 ) {
615 _max = 4;
616 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
617 Node** to = _in;
618 to[0] = NULL;
619 to[1] = NULL;
620 to[2] = NULL;
621 to[3] = NULL;
622 return;
623 }
624 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
625 // Trimming to limit allows a uint8 to handle up to 255 edges.
626 // Previously I was using only powers-of-2 which peaked at 128 edges.
627 //if( new_max >= limit ) new_max = limit-1;
628 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
629 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
630 _max = new_max; // Record new max length
631 // This assertion makes sure that Node::_max is wide enough to
632 // represent the numerical value of new_max.
633 assert(_max == new_max && _max > len, "int width of _max is too small");
634 }
635
636 //-----------------------------out_grow----------------------------------------
637 // Grow the input array, making space for more edges
638 void Node::out_grow( uint len ) {
639 assert(!is_top(), "cannot grow a top node's out array");
640 Arena* arena = Compile::current()->node_arena();
641 uint new_max = _outmax;
642 if( new_max == 0 ) {
643 _outmax = 4;
644 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
645 return;
646 }
647 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
648 // Trimming to limit allows a uint8 to handle up to 255 edges.
649 // Previously I was using only powers-of-2 which peaked at 128 edges.
650 //if( new_max >= limit ) new_max = limit-1;
651 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
652 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
653 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
654 _outmax = new_max; // Record new max length
655 // This assertion makes sure that Node::_max is wide enough to
656 // represent the numerical value of new_max.
657 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
658 }
659
660 #ifdef ASSERT
661 //------------------------------is_dead----------------------------------------
662 bool Node::is_dead() const {
663 // Mach and pinch point nodes may look like dead.
664 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
665 return false;
666 for( uint i = 0; i < _max; i++ )
667 if( _in[i] != NULL )
668 return false;
669 dump();
670 return true;
671 }
672 #endif
673
674 //------------------------------add_req----------------------------------------
675 // Add a new required input at the end
676 void Node::add_req( Node *n ) {
677 assert( is_not_dead(n), "can not use dead node");
678
679 // Look to see if I can move precedence down one without reallocating
680 if( (_cnt >= _max) || (in(_max-1) != NULL) )
681 grow( _max+1 );
682
683 // Find a precedence edge to move
684 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
685 uint i;
686 for( i=_cnt; i<_max; i++ )
687 if( in(i) == NULL ) // Find the NULL at end of prec edge list
688 break; // There must be one, since we grew the array
689 _in[i] = in(_cnt); // Move prec over, making space for req edge
690 }
691 _in[_cnt++] = n; // Stuff over old prec edge
692 if (n != NULL) n->add_out((Node *)this);
693 }
694
695 //---------------------------add_req_batch-------------------------------------
696 // Add a new required input at the end
697 void Node::add_req_batch( Node *n, uint m ) {
698 assert( is_not_dead(n), "can not use dead node");
699 // check various edge cases
700 if ((int)m <= 1) {
701 assert((int)m >= 0, "oob");
702 if (m != 0) add_req(n);
703 return;
704 }
705
706 // Look to see if I can move precedence down one without reallocating
707 if( (_cnt+m) > _max || _in[_max-m] )
708 grow( _max+m );
709
710 // Find a precedence edge to move
711 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
712 uint i;
713 for( i=_cnt; i<_max; i++ )
714 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
715 break; // There must be one, since we grew the array
716 // Slide all the precs over by m positions (assume #prec << m).
717 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
718 }
719
720 // Stuff over the old prec edges
721 for(uint i=0; i<m; i++ ) {
722 _in[_cnt++] = n;
723 }
724
725 // Insert multiple out edges on the node.
726 if (n != NULL && !n->is_top()) {
727 for(uint i=0; i<m; i++ ) {
728 n->add_out((Node *)this);
729 }
730 }
731 }
732
733 //------------------------------del_req----------------------------------------
734 // Delete the required edge and compact the edge array
735 void Node::del_req( uint idx ) {
736 // First remove corresponding def-use edge
737 Node *n = in(idx);
738 if (n != NULL) n->del_out((Node *)this);
739 _in[idx] = in(--_cnt); // Compact the array
740 _in[_cnt] = NULL; // NULL out emptied slot
741 }
742
743 //------------------------------ins_req----------------------------------------
744 // Insert a new required input at the end
745 void Node::ins_req( uint idx, Node *n ) {
746 assert( is_not_dead(n), "can not use dead node");
747 add_req(NULL); // Make space
748 assert( idx < _max, "Must have allocated enough space");
749 // Slide over
750 if(_cnt-idx-1 > 0) {
751 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
752 }
753 _in[idx] = n; // Stuff over old required edge
754 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
755 }
756
757 //-----------------------------find_edge---------------------------------------
758 int Node::find_edge(Node* n) {
759 for (uint i = 0; i < len(); i++) {
760 if (_in[i] == n) return i;
761 }
762 return -1;
763 }
764
765 //----------------------------replace_edge-------------------------------------
766 int Node::replace_edge(Node* old, Node* neww) {
767 if (old == neww) return 0; // nothing to do
768 uint nrep = 0;
769 for (uint i = 0; i < len(); i++) {
770 if (in(i) == old) {
771 if (i < req())
772 set_req(i, neww);
773 else
774 set_prec(i, neww);
775 nrep++;
776 }
777 }
778 return nrep;
779 }
780
781 //-------------------------disconnect_inputs-----------------------------------
782 // NULL out all inputs to eliminate incoming Def-Use edges.
783 // Return the number of edges between 'n' and 'this'
784 int Node::disconnect_inputs(Node *n) {
785 int edges_to_n = 0;
786
787 uint cnt = req();
788 for( uint i = 0; i < cnt; ++i ) {
789 if( in(i) == 0 ) continue;
790 if( in(i) == n ) ++edges_to_n;
791 set_req(i, NULL);
792 }
793 // Remove precedence edges if any exist
794 // Note: Safepoints may have precedence edges, even during parsing
795 if( (req() != len()) && (in(req()) != NULL) ) {
796 uint max = len();
797 for( uint i = 0; i < max; ++i ) {
798 if( in(i) == 0 ) continue;
799 if( in(i) == n ) ++edges_to_n;
800 set_prec(i, NULL);
801 }
802 }
803
804 // Node::destruct requires all out edges be deleted first
805 // debug_only(destruct();) // no reuse benefit expected
806 return edges_to_n;
807 }
808
809 //-----------------------------uncast---------------------------------------
810 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
811 // Strip away casting. (It is depth-limited.)
812 Node* Node::uncast() const {
813 // Should be inline:
814 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
815 if (is_ConstraintCast() || is_CheckCastPP())
816 return uncast_helper(this);
817 else
818 return (Node*) this;
819 }
820
821 //---------------------------uncast_helper-------------------------------------
822 Node* Node::uncast_helper(const Node* p) {
823 uint max_depth = 3;
824 for (uint i = 0; i < max_depth; i++) {
825 if (p == NULL || p->req() != 2) {
826 break;
827 } else if (p->is_ConstraintCast()) {
828 p = p->in(1);
829 } else if (p->is_CheckCastPP()) {
830 p = p->in(1);
831 } else {
832 break;
833 }
834 }
835 return (Node*) p;
836 }
837
838 //------------------------------add_prec---------------------------------------
839 // Add a new precedence input. Precedence inputs are unordered, with
840 // duplicates removed and NULLs packed down at the end.
841 void Node::add_prec( Node *n ) {
842 assert( is_not_dead(n), "can not use dead node");
843
844 // Check for NULL at end
845 if( _cnt >= _max || in(_max-1) )
846 grow( _max+1 );
847
848 // Find a precedence edge to move
849 uint i = _cnt;
850 while( in(i) != NULL ) i++;
851 _in[i] = n; // Stuff prec edge over NULL
852 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
853 }
854
855 //------------------------------rm_prec----------------------------------------
856 // Remove a precedence input. Precedence inputs are unordered, with
857 // duplicates removed and NULLs packed down at the end.
858 void Node::rm_prec( uint j ) {
859
860 // Find end of precedence list to pack NULLs
861 uint i;
862 for( i=j; i<_max; i++ )
863 if( !_in[i] ) // Find the NULL at end of prec edge list
864 break;
865 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
866 _in[j] = _in[--i]; // Move last element over removed guy
867 _in[i] = NULL; // NULL out last element
868 }
869
870 //------------------------------size_of----------------------------------------
871 uint Node::size_of() const { return sizeof(*this); }
872
873 //------------------------------ideal_reg--------------------------------------
874 uint Node::ideal_reg() const { return 0; }
875
876 //------------------------------jvms-------------------------------------------
877 JVMState* Node::jvms() const { return NULL; }
878
879 #ifdef ASSERT
880 //------------------------------jvms-------------------------------------------
881 bool Node::verify_jvms(const JVMState* using_jvms) const {
882 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
883 if (jvms == using_jvms) return true;
884 }
885 return false;
886 }
887
888 //------------------------------init_NodeProperty------------------------------
889 void Node::init_NodeProperty() {
890 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
891 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
892 }
893 #endif
894
895 //------------------------------format-----------------------------------------
896 // Print as assembly
897 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
898 //------------------------------emit-------------------------------------------
899 // Emit bytes starting at parameter 'ptr'.
900 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
901 //------------------------------size-------------------------------------------
902 // Size of instruction in bytes
903 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
904
905 //------------------------------CFG Construction-------------------------------
906 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
907 // Goto and Return.
908 const Node *Node::is_block_proj() const { return 0; }
909
910 // Minimum guaranteed type
911 const Type *Node::bottom_type() const { return Type::BOTTOM; }
912
913
914 //------------------------------raise_bottom_type------------------------------
915 // Get the worst-case Type output for this Node.
916 void Node::raise_bottom_type(const Type* new_type) {
917 if (is_Type()) {
918 TypeNode *n = this->as_Type();
919 if (VerifyAliases) {
920 assert(new_type->higher_equal(n->type()), "new type must refine old type");
921 }
922 n->set_type(new_type);
923 } else if (is_Load()) {
924 LoadNode *n = this->as_Load();
925 if (VerifyAliases) {
926 assert(new_type->higher_equal(n->type()), "new type must refine old type");
927 }
928 n->set_type(new_type);
929 }
930 }
931
932 //------------------------------Identity---------------------------------------
933 // Return a node that the given node is equivalent to.
934 Node *Node::Identity( PhaseTransform * ) {
935 return this; // Default to no identities
936 }
937
938 //------------------------------Value------------------------------------------
939 // Compute a new Type for a node using the Type of the inputs.
940 const Type *Node::Value( PhaseTransform * ) const {
941 return bottom_type(); // Default to worst-case Type
942 }
943
944 //------------------------------Ideal------------------------------------------
945 //
946 // 'Idealize' the graph rooted at this Node.
947 //
948 // In order to be efficient and flexible there are some subtle invariants
949 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
950 // these invariants, although its too slow to have on by default. If you are
951 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
952 //
953 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
954 // pointer. If ANY change is made, it must return the root of the reshaped
955 // graph - even if the root is the same Node. Example: swapping the inputs
956 // to an AddINode gives the same answer and same root, but you still have to
957 // return the 'this' pointer instead of NULL.
958 //
959 // You cannot return an OLD Node, except for the 'this' pointer. Use the
960 // Identity call to return an old Node; basically if Identity can find
961 // another Node have the Ideal call make no change and return NULL.
962 // Example: AddINode::Ideal must check for add of zero; in this case it
963 // returns NULL instead of doing any graph reshaping.
964 //
965 // You cannot modify any old Nodes except for the 'this' pointer. Due to
966 // sharing there may be other users of the old Nodes relying on their current
967 // semantics. Modifying them will break the other users.
968 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
969 // "X+3" unchanged in case it is shared.
970 //
971 // If you modify the 'this' pointer's inputs, you must use 'set_req' with
972 // def-use info. If you are making a new Node (either as the new root or
973 // some new internal piece) you must NOT use set_req with def-use info.
974 // You can make a new Node with either 'new' or 'clone'. In either case,
975 // def-use info is (correctly) not generated.
976 // Example: reshape "(X+3)+4" into "X+7":
977 // set_req(1,in(1)->in(1) /* grab X */, du /* must use DU on 'this' */);
978 // set_req(2,phase->intcon(7),du);
979 // return this;
980 // Example: reshape "X*4" into "X<<1"
981 // return new (C,3) LShiftINode( in(1), phase->intcon(1) );
982 //
983 // You must call 'phase->transform(X)' on any new Nodes X you make, except
984 // for the returned root node. Example: reshape "X*31" with "(X<<5)-1".
985 // Node *shift=phase->transform(new(C,3)LShiftINode(in(1),phase->intcon(5)));
986 // return new (C,3) AddINode(shift, phase->intcon(-1));
987 //
988 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
989 // These forms are faster than 'phase->transform(new (C,1) ConNode())' and Do
990 // The Right Thing with def-use info.
991 //
992 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
993 // graph uses the 'this' Node it must be the root. If you want a Node with
994 // the same Opcode as the 'this' pointer use 'clone'.
995 //
996 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
997 return NULL; // Default to being Ideal already
998 }
999
1000 // Some nodes have specific Ideal subgraph transformations only if they are
1001 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1002 // for the transformations to happen.
1003 bool Node::has_special_unique_user() const {
1004 assert(outcnt() == 1, "match only for unique out");
1005 Node* n = unique_out();
1006 int op = Opcode();
1007 if( this->is_Store() ) {
1008 // Condition for back-to-back stores folding.
1009 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1010 } else if( op == Op_AddL ) {
1011 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1012 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1013 } else if( op == Op_SubI || op == Op_SubL ) {
1014 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1015 return n->Opcode() == op && n->in(2) == this;
1016 }
1017 return false;
1018 };
1019
1020 //--------------------------find_exact_control---------------------------------
1021 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1022 Node* Node::find_exact_control(Node* ctrl) {
1023 if (ctrl == NULL && this->is_Region())
1024 ctrl = this->as_Region()->is_copy();
1025
1026 if (ctrl != NULL && ctrl->is_CatchProj()) {
1027 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1028 ctrl = ctrl->in(0);
1029 if (ctrl != NULL && !ctrl->is_top())
1030 ctrl = ctrl->in(0);
1031 }
1032
1033 if (ctrl != NULL && ctrl->is_Proj())
1034 ctrl = ctrl->in(0);
1035
1036 return ctrl;
1037 }
1038
1039 //--------------------------dominates------------------------------------------
1040 // Helper function for MemNode::all_controls_dominate().
1041 // Check if 'this' control node dominates or equal to 'sub' control node.
1042 bool Node::dominates(Node* sub, Node_List &nlist) {
1043 assert(this->is_CFG(), "expecting control");
1044 assert(sub != NULL && sub->is_CFG(), "expecting control");
1045
1046 Node* orig_sub = sub;
1047 nlist.clear();
1048 bool this_dominates = false;
1049 uint region_input = 0;
1050 while (sub != NULL) { // walk 'sub' up the chain to 'this'
1051 if (sub == this) {
1052 if (nlist.size() == 0) {
1053 // No Region nodes except loops were visited before and the EntryControl
1054 // path was taken for loops: it did not walk in a cycle.
1055 return true;
1056 } else if (!this_dominates) {
1057 // Region nodes were visited. Continue walk up to Start or Root
1058 // to make sure that it did not walk in a cycle.
1059 this_dominates = true; // first time meet
1060 } else {
1061 return false; // already met before: walk in a cycle
1062 }
1063 }
1064 if (sub->is_Start() || sub->is_Root())
1065 return this_dominates;
1066
1067 Node* up = sub->find_exact_control(sub->in(0));
1068 if (up == NULL || up->is_top())
1069 return false; // Conservative answer for dead code
1070
1071 if (sub == up && sub->is_Loop()) {
1072 up = sub->in(0); // in(LoopNode::EntryControl);
1073 } else if (sub == up && sub->is_Region()) {
1074 uint i = 1;
1075 if (nlist.size() == 0) {
1076 // No Region nodes (except Loops) were visited before.
1077 // Take first valid path on the way up to 'this'.
1078 } else if (nlist.at(nlist.size() - 1) == sub) {
1079 // This Region node was just visited. Take other path.
1080 i = region_input + 1;
1081 nlist.pop();
1082 } else {
1083 // Was this Region node visited before?
1084 uint size = nlist.size();
1085 for (uint j = 0; j < size; j++) {
1086 if (nlist.at(j) == sub) {
1087 return false; // The Region node was visited before. Give up.
1088 }
1089 }
1090 // The Region node was not visited before.
1091 // Take first valid path on the way up to 'this'.
1092 }
1093 for (; i < sub->req(); i++) {
1094 Node* in = sub->in(i);
1095 if (in != NULL && !in->is_top() && in != sub) {
1096 break;
1097 }
1098 }
1099 if (i < sub->req()) {
1100 nlist.push(sub);
1101 up = sub->in(i);
1102 region_input = i;
1103 }
1104 }
1105 if (sub == up)
1106 return false; // some kind of tight cycle
1107 if (orig_sub == up)
1108 return false; // walk in a cycle
1109
1110 sub = up;
1111 }
1112 return false;
1113 }
1114
1115 //------------------------------remove_dead_region-----------------------------
1116 // This control node is dead. Follow the subgraph below it making everything
1117 // using it dead as well. This will happen normally via the usual IterGVN
1118 // worklist but this call is more efficient. Do not update use-def info
1119 // inside the dead region, just at the borders.
1120 static bool kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1121 // Con's are a popular node to re-hit in the hash table again.
1122 if( dead->is_Con() ) return false;
1123
1124 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1125 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1126 Node_List nstack(Thread::current()->resource_area());
1127
1128 Node *top = igvn->C->top();
1129 bool progress = false;
1130 nstack.push(dead);
1131
1132 while (nstack.size() > 0) {
1133 dead = nstack.pop();
1134 if (dead->outcnt() > 0) {
1135 // Keep dead node on stack until all uses are processed.
1136 nstack.push(dead);
1137 // For all Users of the Dead... ;-)
1138 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1139 Node* use = dead->last_out(k);
1140 igvn->hash_delete(use); // Yank from hash table prior to mod
1141 if (use->in(0) == dead) { // Found another dead node
1142 assert (!use->is_Con(), "Control for Con node should be Root node.")
1143 use->set_req(0, top); // Cut dead edge to prevent processing
1144 nstack.push(use); // the dead node again.
1145 } else { // Else found a not-dead user
1146 for (uint j = 1; j < use->req(); j++) {
1147 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1148 use->set_req(j, top);
1149 }
1150 }
1151 igvn->_worklist.push(use);
1152 }
1153 // Refresh the iterator, since any number of kills might have happened.
1154 k = dead->last_outs(kmin);
1155 }
1156 } else { // (dead->outcnt() == 0)
1157 // Done with outputs.
1158 igvn->hash_delete(dead);
1159 igvn->_worklist.remove(dead);
1160 igvn->set_type(dead, Type::TOP);
1161 if (dead->is_macro()) {
1162 igvn->C->remove_macro_node(dead);
1163 }
1164 // Kill all inputs to the dead guy
1165 for (uint i=0; i < dead->req(); i++) {
1166 Node *n = dead->in(i); // Get input to dead guy
1167 if (n != NULL && !n->is_top()) { // Input is valid?
1168 progress = true;
1169 dead->set_req(i, top); // Smash input away
1170 if (n->outcnt() == 0) { // Input also goes dead?
1171 if (!n->is_Con())
1172 nstack.push(n); // Clear it out as well
1173 } else if (n->outcnt() == 1 &&
1174 n->has_special_unique_user()) {
1175 igvn->add_users_to_worklist( n );
1176 } else if (n->outcnt() <= 2 && n->is_Store()) {
1177 // Push store's uses on worklist to enable folding optimization for
1178 // store/store and store/load to the same address.
1179 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1180 // and remove_globally_dead_node().
1181 igvn->add_users_to_worklist( n );
1182 }
1183 }
1184 }
1185 } // (dead->outcnt() == 0)
1186 } // while (nstack.size() > 0) for outputs
1187 return progress;
1188 }
1189
1190 //------------------------------remove_dead_region-----------------------------
1191 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1192 Node *n = in(0);
1193 if( !n ) return false;
1194 // Lost control into this guy? I.e., it became unreachable?
1195 // Aggressively kill all unreachable code.
1196 if (can_reshape && n->is_top()) {
1197 return kill_dead_code(this, phase->is_IterGVN());
1198 }
1199
1200 if( n->is_Region() && n->as_Region()->is_copy() ) {
1201 Node *m = n->nonnull_req();
1202 set_req(0, m);
1203 return true;
1204 }
1205 return false;
1206 }
1207
1208 //------------------------------Ideal_DU_postCCP-------------------------------
1209 // Idealize graph, using DU info. Must clone result into new-space
1210 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1211 return NULL; // Default to no change
1212 }
1213
1214 //------------------------------hash-------------------------------------------
1215 // Hash function over Nodes.
1216 uint Node::hash() const {
1217 uint sum = 0;
1218 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1219 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1220 return (sum>>2) + _cnt + Opcode();
1221 }
1222
1223 //------------------------------cmp--------------------------------------------
1224 // Compare special parts of simple Nodes
1225 uint Node::cmp( const Node &n ) const {
1226 return 1; // Must be same
1227 }
1228
1229 //------------------------------rematerialize-----------------------------------
1230 // Should we clone rather than spill this instruction?
1231 bool Node::rematerialize() const {
1232 if ( is_Mach() )
1233 return this->as_Mach()->rematerialize();
1234 else
1235 return (_flags & Flag_rematerialize) != 0;
1236 }
1237
1238 //------------------------------needs_anti_dependence_check---------------------
1239 // Nodes which use memory without consuming it, hence need antidependences.
1240 bool Node::needs_anti_dependence_check() const {
1241 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1242 return false;
1243 else
1244 return in(1)->bottom_type()->has_memory();
1245 }
1246
1247
1248 // Get an integer constant from a ConNode (or CastIINode).
1249 // Return a default value if there is no apparent constant here.
1250 const TypeInt* Node::find_int_type() const {
1251 if (this->is_Type()) {
1252 return this->as_Type()->type()->isa_int();
1253 } else if (this->is_Con()) {
1254 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1255 return this->bottom_type()->isa_int();
1256 }
1257 return NULL;
1258 }
1259
1260 // Get a pointer constant from a ConstNode.
1261 // Returns the constant if it is a pointer ConstNode
1262 intptr_t Node::get_ptr() const {
1263 assert( Opcode() == Op_ConP, "" );
1264 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1265 }
1266
1267 // Get a narrow oop constant from a ConNNode.
1268 intptr_t Node::get_narrowcon() const {
1269 assert( Opcode() == Op_ConN, "" );
1270 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1271 }
1272
1273 // Get a long constant from a ConNode.
1274 // Return a default value if there is no apparent constant here.
1275 const TypeLong* Node::find_long_type() const {
1276 if (this->is_Type()) {
1277 return this->as_Type()->type()->isa_long();
1278 } else if (this->is_Con()) {
1279 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1280 return this->bottom_type()->isa_long();
1281 }
1282 return NULL;
1283 }
1284
1285 // Get a double constant from a ConstNode.
1286 // Returns the constant if it is a double ConstNode
1287 jdouble Node::getd() const {
1288 assert( Opcode() == Op_ConD, "" );
1289 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1290 }
1291
1292 // Get a float constant from a ConstNode.
1293 // Returns the constant if it is a float ConstNode
1294 jfloat Node::getf() const {
1295 assert( Opcode() == Op_ConF, "" );
1296 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1297 }
1298
1299 #ifndef PRODUCT
1300
1301 //----------------------------NotANode----------------------------------------
1302 // Used in debugging code to avoid walking across dead or uninitialized edges.
1303 static inline bool NotANode(const Node* n) {
1304 if (n == NULL) return true;
1305 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1306 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1307 return false;
1308 }
1309
1310
1311 //------------------------------find------------------------------------------
1312 // Find a neighbor of this Node with the given _idx
1313 // If idx is negative, find its absolute value, following both _in and _out.
1314 static void find_recur( Node* &result, Node *n, int idx, bool only_ctrl,
1315 VectorSet &old_space, VectorSet &new_space ) {
1316 int node_idx = (idx >= 0) ? idx : -idx;
1317 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1318 // Contained in new_space or old_space?
1319 VectorSet *v = Compile::current()->node_arena()->contains(n) ? &new_space : &old_space;
1320 if( v->test(n->_idx) ) return;
1321 if( (int)n->_idx == node_idx
1322 debug_only(|| n->debug_idx() == node_idx) ) {
1323 if (result != NULL)
1324 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1325 (uintptr_t)result, (uintptr_t)n, node_idx);
1326 result = n;
1327 }
1328 v->set(n->_idx);
1329 for( uint i=0; i<n->len(); i++ ) {
1330 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1331 find_recur( result, n->in(i), idx, only_ctrl, old_space, new_space );
1332 }
1333 // Search along forward edges also:
1334 if (idx < 0 && !only_ctrl) {
1335 for( uint j=0; j<n->outcnt(); j++ ) {
1336 find_recur( result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1337 }
1338 }
1339 #ifdef ASSERT
1340 // Search along debug_orig edges last:
1341 for (Node* orig = n->debug_orig(); orig != NULL; orig = orig->debug_orig()) {
1342 if (NotANode(orig)) break;
1343 find_recur( result, orig, idx, only_ctrl, old_space, new_space );
1344 }
1345 #endif //ASSERT
1346 }
1347
1348 // call this from debugger:
1349 Node* find_node(Node* n, int idx) {
1350 return n->find(idx);
1351 }
1352
1353 //------------------------------find-------------------------------------------
1354 Node* Node::find(int idx) const {
1355 ResourceArea *area = Thread::current()->resource_area();
1356 VectorSet old_space(area), new_space(area);
1357 Node* result = NULL;
1358 find_recur( result, (Node*) this, idx, false, old_space, new_space );
1359 return result;
1360 }
1361
1362 //------------------------------find_ctrl--------------------------------------
1363 // Find an ancestor to this node in the control history with given _idx
1364 Node* Node::find_ctrl(int idx) const {
1365 ResourceArea *area = Thread::current()->resource_area();
1366 VectorSet old_space(area), new_space(area);
1367 Node* result = NULL;
1368 find_recur( result, (Node*) this, idx, true, old_space, new_space );
1369 return result;
1370 }
1371 #endif
1372
1373
1374
1375 #ifndef PRODUCT
1376 int Node::_in_dump_cnt = 0;
1377
1378 // -----------------------------Name-------------------------------------------
1379 extern const char *NodeClassNames[];
1380 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1381
1382 static bool is_disconnected(const Node* n) {
1383 for (uint i = 0; i < n->req(); i++) {
1384 if (n->in(i) != NULL) return false;
1385 }
1386 return true;
1387 }
1388
1389 #ifdef ASSERT
1390 static void dump_orig(Node* orig) {
1391 Compile* C = Compile::current();
1392 if (NotANode(orig)) orig = NULL;
1393 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1394 if (orig == NULL) return;
1395 tty->print(" !orig=");
1396 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1397 if (NotANode(fast)) fast = NULL;
1398 while (orig != NULL) {
1399 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1400 if (discon) tty->print("[");
1401 if (!Compile::current()->node_arena()->contains(orig))
1402 tty->print("o");
1403 tty->print("%d", orig->_idx);
1404 if (discon) tty->print("]");
1405 orig = orig->debug_orig();
1406 if (NotANode(orig)) orig = NULL;
1407 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1408 if (orig != NULL) tty->print(",");
1409 if (fast != NULL) {
1410 // Step fast twice for each single step of orig:
1411 fast = fast->debug_orig();
1412 if (NotANode(fast)) fast = NULL;
1413 if (fast != NULL && fast != orig) {
1414 fast = fast->debug_orig();
1415 if (NotANode(fast)) fast = NULL;
1416 }
1417 if (fast == orig) {
1418 tty->print("...");
1419 break;
1420 }
1421 }
1422 }
1423 }
1424
1425 void Node::set_debug_orig(Node* orig) {
1426 _debug_orig = orig;
1427 if (BreakAtNode == 0) return;
1428 if (NotANode(orig)) orig = NULL;
1429 int trip = 10;
1430 while (orig != NULL) {
1431 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1432 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1433 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1434 BREAKPOINT;
1435 }
1436 orig = orig->debug_orig();
1437 if (NotANode(orig)) orig = NULL;
1438 if (trip-- <= 0) break;
1439 }
1440 }
1441 #endif //ASSERT
1442
1443 //------------------------------dump------------------------------------------
1444 // Dump a Node
1445 void Node::dump() const {
1446 Compile* C = Compile::current();
1447 bool is_new = C->node_arena()->contains(this);
1448 _in_dump_cnt++;
1449 tty->print("%c%d\t%s\t=== ",
1450 is_new ? ' ' : 'o', _idx, Name());
1451
1452 // Dump the required and precedence inputs
1453 dump_req();
1454 dump_prec();
1455 // Dump the outputs
1456 dump_out();
1457
1458 if (is_disconnected(this)) {
1459 #ifdef ASSERT
1460 tty->print(" [%d]",debug_idx());
1461 dump_orig(debug_orig());
1462 #endif
1463 tty->cr();
1464 _in_dump_cnt--;
1465 return; // don't process dead nodes
1466 }
1467
1468 // Dump node-specific info
1469 dump_spec(tty);
1470 #ifdef ASSERT
1471 // Dump the non-reset _debug_idx
1472 if( Verbose && WizardMode ) {
1473 tty->print(" [%d]",debug_idx());
1474 }
1475 #endif
1476
1477 const Type *t = bottom_type();
1478
1479 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1480 const TypeInstPtr *toop = t->isa_instptr();
1481 const TypeKlassPtr *tkls = t->isa_klassptr();
1482 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1483 if( klass && klass->is_loaded() && klass->is_interface() ) {
1484 tty->print(" Interface:");
1485 } else if( toop ) {
1486 tty->print(" Oop:");
1487 } else if( tkls ) {
1488 tty->print(" Klass:");
1489 }
1490 t->dump();
1491 } else if( t == Type::MEMORY ) {
1492 tty->print(" Memory:");
1493 MemNode::dump_adr_type(this, adr_type(), tty);
1494 } else if( Verbose || WizardMode ) {
1495 tty->print(" Type:");
1496 if( t ) {
1497 t->dump();
1498 } else {
1499 tty->print("no type");
1500 }
1501 }
1502 if (is_new) {
1503 debug_only(dump_orig(debug_orig()));
1504 Node_Notes* nn = C->node_notes_at(_idx);
1505 if (nn != NULL && !nn->is_clear()) {
1506 if (nn->jvms() != NULL) {
1507 tty->print(" !jvms:");
1508 nn->jvms()->dump_spec(tty);
1509 }
1510 }
1511 }
1512 tty->cr();
1513 _in_dump_cnt--;
1514 }
1515
1516 //------------------------------dump_req--------------------------------------
1517 void Node::dump_req() const {
1518 // Dump the required input edges
1519 for (uint i = 0; i < req(); i++) { // For all required inputs
1520 Node* d = in(i);
1521 if (d == NULL) {
1522 tty->print("_ ");
1523 } else if (NotANode(d)) {
1524 tty->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1525 } else {
1526 tty->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1527 }
1528 }
1529 }
1530
1531
1532 //------------------------------dump_prec-------------------------------------
1533 void Node::dump_prec() const {
1534 // Dump the precedence edges
1535 int any_prec = 0;
1536 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1537 Node* p = in(i);
1538 if (p != NULL) {
1539 if( !any_prec++ ) tty->print(" |");
1540 if (NotANode(p)) { tty->print("NotANode "); continue; }
1541 tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1542 }
1543 }
1544 }
1545
1546 //------------------------------dump_out--------------------------------------
1547 void Node::dump_out() const {
1548 // Delimit the output edges
1549 tty->print(" [[");
1550 // Dump the output edges
1551 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1552 Node* u = _out[i];
1553 if (u == NULL) {
1554 tty->print("_ ");
1555 } else if (NotANode(u)) {
1556 tty->print("NotANode ");
1557 } else {
1558 tty->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1559 }
1560 }
1561 tty->print("]] ");
1562 }
1563
1564 //------------------------------dump_nodes-------------------------------------
1565 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1566 Node* s = (Node*)start; // remove const
1567 if (NotANode(s)) return;
1568
1569 uint depth = (uint)ABS(d);
1570 int direction = d;
1571 Compile* C = Compile::current();
1572 GrowableArray <Node *> nstack(C->unique());
1573
1574 nstack.append(s);
1575 int begin = 0;
1576 int end = 0;
1577 for(uint i = 0; i < depth; i++) {
1578 end = nstack.length();
1579 for(int j = begin; j < end; j++) {
1580 Node* tp = nstack.at(j);
1581 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1582 for(uint k = 0; k < limit; k++) {
1583 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1584
1585 if (NotANode(n)) continue;
1586 // do not recurse through top or the root (would reach unrelated stuff)
1587 if (n->is_Root() || n->is_top()) continue;
1588 if (only_ctrl && !n->is_CFG()) continue;
1589
1590 bool on_stack = nstack.contains(n);
1591 if (!on_stack) {
1592 nstack.append(n);
1593 }
1594 }
1595 }
1596 begin = end;
1597 }
1598 end = nstack.length();
1599 if (direction > 0) {
1600 for(int j = end-1; j >= 0; j--) {
1601 nstack.at(j)->dump();
1602 }
1603 } else {
1604 for(int j = 0; j < end; j++) {
1605 nstack.at(j)->dump();
1606 }
1607 }
1608 }
1609
1610 //------------------------------dump-------------------------------------------
1611 void Node::dump(int d) const {
1612 dump_nodes(this, d, false);
1613 }
1614
1615 //------------------------------dump_ctrl--------------------------------------
1616 // Dump a Node's control history to depth
1617 void Node::dump_ctrl(int d) const {
1618 dump_nodes(this, d, true);
1619 }
1620
1621 // VERIFICATION CODE
1622 // For each input edge to a node (ie - for each Use-Def edge), verify that
1623 // there is a corresponding Def-Use edge.
1624 //------------------------------verify_edges-----------------------------------
1625 void Node::verify_edges(Unique_Node_List &visited) {
1626 uint i, j, idx;
1627 int cnt;
1628 Node *n;
1629
1630 // Recursive termination test
1631 if (visited.member(this)) return;
1632 visited.push(this);
1633
1634 // Walk over all input edges, checking for correspondance
1635 for( i = 0; i < len(); i++ ) {
1636 n = in(i);
1637 if (n != NULL && !n->is_top()) {
1638 // Count instances of (Node *)this
1639 cnt = 0;
1640 for (idx = 0; idx < n->_outcnt; idx++ ) {
1641 if (n->_out[idx] == (Node *)this) cnt++;
1642 }
1643 assert( cnt > 0,"Failed to find Def-Use edge." );
1644 // Check for duplicate edges
1645 // walk the input array downcounting the input edges to n
1646 for( j = 0; j < len(); j++ ) {
1647 if( in(j) == n ) cnt--;
1648 }
1649 assert( cnt == 0,"Mismatched edge count.");
1650 } else if (n == NULL) {
1651 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1652 } else {
1653 assert(n->is_top(), "sanity");
1654 // Nothing to check.
1655 }
1656 }
1657 // Recursive walk over all input edges
1658 for( i = 0; i < len(); i++ ) {
1659 n = in(i);
1660 if( n != NULL )
1661 in(i)->verify_edges(visited);
1662 }
1663 }
1664
1665 //------------------------------verify_recur-----------------------------------
1666 static const Node *unique_top = NULL;
1667
1668 void Node::verify_recur(const Node *n, int verify_depth,
1669 VectorSet &old_space, VectorSet &new_space) {
1670 if ( verify_depth == 0 ) return;
1671 if (verify_depth > 0) --verify_depth;
1672
1673 Compile* C = Compile::current();
1674
1675 // Contained in new_space or old_space?
1676 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1677 // Check for visited in the proper space. Numberings are not unique
1678 // across spaces so we need a seperate VectorSet for each space.
1679 if( v->test_set(n->_idx) ) return;
1680
1681 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1682 if (C->cached_top_node() == NULL)
1683 C->set_cached_top_node((Node*)n);
1684 assert(C->cached_top_node() == n, "TOP node must be unique");
1685 }
1686
1687 for( uint i = 0; i < n->len(); i++ ) {
1688 Node *x = n->in(i);
1689 if (!x || x->is_top()) continue;
1690
1691 // Verify my input has a def-use edge to me
1692 if (true /*VerifyDefUse*/) {
1693 // Count use-def edges from n to x
1694 int cnt = 0;
1695 for( uint j = 0; j < n->len(); j++ )
1696 if( n->in(j) == x )
1697 cnt++;
1698 // Count def-use edges from x to n
1699 uint max = x->_outcnt;
1700 for( uint k = 0; k < max; k++ )
1701 if (x->_out[k] == n)
1702 cnt--;
1703 assert( cnt == 0, "mismatched def-use edge counts" );
1704 }
1705
1706 verify_recur(x, verify_depth, old_space, new_space);
1707 }
1708
1709 }
1710
1711 //------------------------------verify-----------------------------------------
1712 // Check Def-Use info for my subgraph
1713 void Node::verify() const {
1714 Compile* C = Compile::current();
1715 Node* old_top = C->cached_top_node();
1716 ResourceMark rm;
1717 ResourceArea *area = Thread::current()->resource_area();
1718 VectorSet old_space(area), new_space(area);
1719 verify_recur(this, -1, old_space, new_space);
1720 C->set_cached_top_node(old_top);
1721 }
1722 #endif
1723
1724
1725 //------------------------------walk-------------------------------------------
1726 // Graph walk, with both pre-order and post-order functions
1727 void Node::walk(NFunc pre, NFunc post, void *env) {
1728 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1729 walk_(pre, post, env, visited);
1730 }
1731
1732 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1733 if( visited.test_set(_idx) ) return;
1734 pre(*this,env); // Call the pre-order walk function
1735 for( uint i=0; i<_max; i++ )
1736 if( in(i) ) // Input exists and is not walked?
1737 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1738 post(*this,env); // Call the post-order walk function
1739 }
1740
1741 void Node::nop(Node &, void*) {}
1742
1743 //------------------------------Registers--------------------------------------
1744 // Do we Match on this edge index or not? Generally false for Control
1745 // and true for everything else. Weird for calls & returns.
1746 uint Node::match_edge(uint idx) const {
1747 return idx; // True for other than index 0 (control)
1748 }
1749
1750 // Register classes are defined for specific machines
1751 const RegMask &Node::out_RegMask() const {
1752 ShouldNotCallThis();
1753 return *(new RegMask());
1754 }
1755
1756 const RegMask &Node::in_RegMask(uint) const {
1757 ShouldNotCallThis();
1758 return *(new RegMask());
1759 }
1760
1761 //=============================================================================
1762 //-----------------------------------------------------------------------------
1763 void Node_Array::reset( Arena *new_arena ) {
1764 _a->Afree(_nodes,_max*sizeof(Node*));
1765 _max = 0;
1766 _nodes = NULL;
1767 _a = new_arena;
1768 }
1769
1770 //------------------------------clear------------------------------------------
1771 // Clear all entries in _nodes to NULL but keep storage
1772 void Node_Array::clear() {
1773 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1774 }
1775
1776 //-----------------------------------------------------------------------------
1777 void Node_Array::grow( uint i ) {
1778 if( !_max ) {
1779 _max = 1;
1780 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1781 _nodes[0] = NULL;
1782 }
1783 uint old = _max;
1784 while( i >= _max ) _max <<= 1; // Double to fit
1785 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1786 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1787 }
1788
1789 //-----------------------------------------------------------------------------
1790 void Node_Array::insert( uint i, Node *n ) {
1791 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1792 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1793 _nodes[i] = n;
1794 }
1795
1796 //-----------------------------------------------------------------------------
1797 void Node_Array::remove( uint i ) {
1798 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1799 _nodes[_max-1] = NULL;
1800 }
1801
1802 //-----------------------------------------------------------------------------
1803 void Node_Array::sort( C_sort_func_t func) {
1804 qsort( _nodes, _max, sizeof( Node* ), func );
1805 }
1806
1807 //-----------------------------------------------------------------------------
1808 void Node_Array::dump() const {
1809 #ifndef PRODUCT
1810 for( uint i = 0; i < _max; i++ ) {
1811 Node *nn = _nodes[i];
1812 if( nn != NULL ) {
1813 tty->print("%5d--> ",i); nn->dump();
1814 }
1815 }
1816 #endif
1817 }
1818
1819 //--------------------------is_iteratively_computed------------------------------
1820 // Operation appears to be iteratively computed (such as an induction variable)
1821 // It is possible for this operation to return false for a loop-varying
1822 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1823 bool Node::is_iteratively_computed() {
1824 if (ideal_reg()) { // does operation have a result register?
1825 for (uint i = 1; i < req(); i++) {
1826 Node* n = in(i);
1827 if (n != NULL && n->is_Phi()) {
1828 for (uint j = 1; j < n->req(); j++) {
1829 if (n->in(j) == this) {
1830 return true;
1831 }
1832 }
1833 }
1834 }
1835 }
1836 return false;
1837 }
1838
1839 //--------------------------find_similar------------------------------
1840 // Return a node with opcode "opc" and same inputs as "this" if one can
1841 // be found; Otherwise return NULL;
1842 Node* Node::find_similar(int opc) {
1843 if (req() >= 2) {
1844 Node* def = in(1);
1845 if (def && def->outcnt() >= 2) {
1846 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
1847 Node* use = def->fast_out(i);
1848 if (use->Opcode() == opc &&
1849 use->req() == req()) {
1850 uint j;
1851 for (j = 0; j < use->req(); j++) {
1852 if (use->in(j) != in(j)) {
1853 break;
1854 }
1855 }
1856 if (j == use->req()) {
1857 return use;
1858 }
1859 }
1860 }
1861 }
1862 }
1863 return NULL;
1864 }
1865
1866
1867 //--------------------------unique_ctrl_out------------------------------
1868 // Return the unique control out if only one. Null if none or more than one.
1869 Node* Node::unique_ctrl_out() {
1870 Node* found = NULL;
1871 for (uint i = 0; i < outcnt(); i++) {
1872 Node* use = raw_out(i);
1873 if (use->is_CFG() && use != this) {
1874 if (found != NULL) return NULL;
1875 found = use;
1876 }
1877 }
1878 return found;
1879 }
1880
1881 //=============================================================================
1882 //------------------------------yank-------------------------------------------
1883 // Find and remove
1884 void Node_List::yank( Node *n ) {
1885 uint i;
1886 for( i = 0; i < _cnt; i++ )
1887 if( _nodes[i] == n )
1888 break;
1889
1890 if( i < _cnt )
1891 _nodes[i] = _nodes[--_cnt];
1892 }
1893
1894 //------------------------------dump-------------------------------------------
1895 void Node_List::dump() const {
1896 #ifndef PRODUCT
1897 for( uint i = 0; i < _cnt; i++ )
1898 if( _nodes[i] ) {
1899 tty->print("%5d--> ",i);
1900 _nodes[i]->dump();
1901 }
1902 #endif
1903 }
1904
1905 //=============================================================================
1906 //------------------------------remove-----------------------------------------
1907 void Unique_Node_List::remove( Node *n ) {
1908 if( _in_worklist[n->_idx] ) {
1909 for( uint i = 0; i < size(); i++ )
1910 if( _nodes[i] == n ) {
1911 map(i,Node_List::pop());
1912 _in_worklist >>= n->_idx;
1913 return;
1914 }
1915 ShouldNotReachHere();
1916 }
1917 }
1918
1919 //-----------------------remove_useless_nodes----------------------------------
1920 // Remove useless nodes from worklist
1921 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
1922
1923 for( uint i = 0; i < size(); ++i ) {
1924 Node *n = at(i);
1925 assert( n != NULL, "Did not expect null entries in worklist");
1926 if( ! useful.test(n->_idx) ) {
1927 _in_worklist >>= n->_idx;
1928 map(i,Node_List::pop());
1929 // Node *replacement = Node_List::pop();
1930 // if( i != size() ) { // Check if removing last entry
1931 // _nodes[i] = replacement;
1932 // }
1933 --i; // Visit popped node
1934 // If it was last entry, loop terminates since size() was also reduced
1935 }
1936 }
1937 }
1938
1939 //=============================================================================
1940 void Node_Stack::grow() {
1941 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
1942 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
1943 size_t max = old_max << 1; // max * 2
1944 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
1945 _inode_max = _inodes + max;
1946 _inode_top = _inodes + old_top; // restore _top
1947 }
1948
1949 //=============================================================================
1950 uint TypeNode::size_of() const { return sizeof(*this); }
1951 #ifndef PRODUCT
1952 void TypeNode::dump_spec(outputStream *st) const {
1953 if( !Verbose && !WizardMode ) {
1954 // standard dump does this in Verbose and WizardMode
1955 st->print(" #"); _type->dump_on(st);
1956 }
1957 }
1958 #endif
1959 uint TypeNode::hash() const {
1960 return Node::hash() + _type->hash();
1961 }
1962 uint TypeNode::cmp( const Node &n ) const
1963 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
1964 const Type *TypeNode::bottom_type() const { return _type; }
1965 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
1966
1967 //------------------------------ideal_reg--------------------------------------
1968 uint TypeNode::ideal_reg() const {
1969 return Matcher::base2reg[_type->base()];
1970 }