1 /*
2 * Copyright 1997-2008 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() < Compile::current()->nodes_limit(), "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 should use
972 // 'set_req'. If you are making a new Node (either as the new root or
973 // some new internal piece) you may use 'init_req' to set the initial
974 // value. You can make a new Node with either 'new' or 'clone'. In
975 // either case, def-use info is correctly maintained.
976 //
977 // Example: reshape "(X+3)+4" into "X+7":
978 // set_req(1, in(1)->in(1));
979 // set_req(2, phase->intcon(7));
980 // return this;
981 // Example: reshape "X*4" into "X<<2"
982 // return new (C,3) LShiftINode(in(1), phase->intcon(2));
983 //
984 // You must call 'phase->transform(X)' on any new Nodes X you make, except
985 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
986 // Node *shift=phase->transform(new(C,3)LShiftINode(in(1),phase->intcon(5)));
987 // return new (C,3) AddINode(shift, in(1));
988 //
989 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
990 // These forms are faster than 'phase->transform(new (C,1) ConNode())' and Do
991 // The Right Thing with def-use info.
992 //
993 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
994 // graph uses the 'this' Node it must be the root. If you want a Node with
995 // the same Opcode as the 'this' pointer use 'clone'.
996 //
997 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
998 return NULL; // Default to being Ideal already
999 }
1000
1001 // Some nodes have specific Ideal subgraph transformations only if they are
1002 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1003 // for the transformations to happen.
1004 bool Node::has_special_unique_user() const {
1005 assert(outcnt() == 1, "match only for unique out");
1006 Node* n = unique_out();
1007 int op = Opcode();
1008 if( this->is_Store() ) {
1009 // Condition for back-to-back stores folding.
1010 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1011 } else if( op == Op_AddL ) {
1012 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1013 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1014 } else if( op == Op_SubI || op == Op_SubL ) {
1015 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1016 return n->Opcode() == op && n->in(2) == this;
1017 }
1018 return false;
1019 };
1020
1021 //--------------------------find_exact_control---------------------------------
1022 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1023 Node* Node::find_exact_control(Node* ctrl) {
1024 if (ctrl == NULL && this->is_Region())
1025 ctrl = this->as_Region()->is_copy();
1026
1027 if (ctrl != NULL && ctrl->is_CatchProj()) {
1028 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1029 ctrl = ctrl->in(0);
1030 if (ctrl != NULL && !ctrl->is_top())
1031 ctrl = ctrl->in(0);
1032 }
1033
1034 if (ctrl != NULL && ctrl->is_Proj())
1035 ctrl = ctrl->in(0);
1036
1037 return ctrl;
1038 }
1039
1040 //--------------------------dominates------------------------------------------
1041 // Helper function for MemNode::all_controls_dominate().
1042 // Check if 'this' control node dominates or equal to 'sub' control node.
1043 // We already know that if any path back to Root or Start reaches 'this',
1044 // then all paths so, so this is a simple search for one example,
1045 // not an exhaustive search for a counterexample.
1046 bool Node::dominates(Node* sub, Node_List &nlist) {
1047 assert(this->is_CFG(), "expecting control");
1048 assert(sub != NULL && sub->is_CFG(), "expecting control");
1049
1050 // detect dead cycle without regions
1051 int iterations_without_region_limit = DominatorSearchLimit;
1052
1053 Node* orig_sub = sub;
1054 Node* dom = this;
1055 bool met_dom = false;
1056 nlist.clear();
1057
1058 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1059 // After seeing 'dom', continue up to Root or Start.
1060 // If we hit a region (backward split point), it may be a loop head.
1061 // Keep going through one of the region's inputs. If we reach the
1062 // same region again, go through a different input. Eventually we
1063 // will either exit through the loop head, or give up.
1064 // (If we get confused, break out and return a conservative 'false'.)
1065 while (sub != NULL) {
1066 if (sub->is_top()) break; // Conservative answer for dead code.
1067 if (sub == dom) {
1068 if (nlist.size() == 0) {
1069 // No Region nodes except loops were visited before and the EntryControl
1070 // path was taken for loops: it did not walk in a cycle.
1071 return true;
1072 } else if (met_dom) {
1073 break; // already met before: walk in a cycle
1074 } else {
1075 // Region nodes were visited. Continue walk up to Start or Root
1076 // to make sure that it did not walk in a cycle.
1077 met_dom = true; // first time meet
1078 iterations_without_region_limit = DominatorSearchLimit; // Reset
1079 }
1080 }
1081 if (sub->is_Start() || sub->is_Root()) {
1082 // Success if we met 'dom' along a path to Start or Root.
1083 // We assume there are no alternative paths that avoid 'dom'.
1084 // (This assumption is up to the caller to ensure!)
1085 return met_dom;
1086 }
1087 Node* up = sub->in(0);
1088 // Normalize simple pass-through regions and projections:
1089 up = sub->find_exact_control(up);
1090 // If sub == up, we found a self-loop. Try to push past it.
1091 if (sub == up && sub->is_Loop()) {
1092 // Take loop entry path on the way up to 'dom'.
1093 up = sub->in(1); // in(LoopNode::EntryControl);
1094 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1095 // Always take in(1) path on the way up to 'dom' for clone regions
1096 // (with only one input) or regions which merge > 2 paths
1097 // (usually used to merge fast/slow paths).
1098 up = sub->in(1);
1099 } else if (sub == up && sub->is_Region()) {
1100 // Try both paths for Regions with 2 input paths (it may be a loop head).
1101 // It could give conservative 'false' answer without information
1102 // which region's input is the entry path.
1103 iterations_without_region_limit = DominatorSearchLimit; // Reset
1104
1105 bool region_was_visited_before = false;
1106 // Was this Region node visited before?
1107 // If so, we have reached it because we accidentally took a
1108 // loop-back edge from 'sub' back into the body of the loop,
1109 // and worked our way up again to the loop header 'sub'.
1110 // So, take the first unexplored path on the way up to 'dom'.
1111 for (int j = nlist.size() - 1; j >= 0; j--) {
1112 intptr_t ni = (intptr_t)nlist.at(j);
1113 Node* visited = (Node*)(ni & ~1);
1114 bool visited_twice_already = ((ni & 1) != 0);
1115 if (visited == sub) {
1116 if (visited_twice_already) {
1117 // Visited 2 paths, but still stuck in loop body. Give up.
1118 return false;
1119 }
1120 // The Region node was visited before only once.
1121 // (We will repush with the low bit set, below.)
1122 nlist.remove(j);
1123 // We will find a new edge and re-insert.
1124 region_was_visited_before = true;
1125 break;
1126 }
1127 }
1128
1129 // Find an incoming edge which has not been seen yet; walk through it.
1130 assert(up == sub, "");
1131 uint skip = region_was_visited_before ? 1 : 0;
1132 for (uint i = 1; i < sub->req(); i++) {
1133 Node* in = sub->in(i);
1134 if (in != NULL && !in->is_top() && in != sub) {
1135 if (skip == 0) {
1136 up = in;
1137 break;
1138 }
1139 --skip; // skip this nontrivial input
1140 }
1141 }
1142
1143 // Set 0 bit to indicate that both paths were taken.
1144 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1145 }
1146
1147 if (up == sub) {
1148 break; // some kind of tight cycle
1149 }
1150 if (up == orig_sub && met_dom) {
1151 // returned back after visiting 'dom'
1152 break; // some kind of cycle
1153 }
1154 if (--iterations_without_region_limit < 0) {
1155 break; // dead cycle
1156 }
1157 sub = up;
1158 }
1159
1160 // Did not meet Root or Start node in pred. chain.
1161 // Conservative answer for dead code.
1162 return false;
1163 }
1164
1165 //------------------------------remove_dead_region-----------------------------
1166 // This control node is dead. Follow the subgraph below it making everything
1167 // using it dead as well. This will happen normally via the usual IterGVN
1168 // worklist but this call is more efficient. Do not update use-def info
1169 // inside the dead region, just at the borders.
1170 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1171 // Con's are a popular node to re-hit in the hash table again.
1172 if( dead->is_Con() ) return;
1173
1174 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1175 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1176 Node_List nstack(Thread::current()->resource_area());
1177
1178 Node *top = igvn->C->top();
1179 nstack.push(dead);
1180
1181 while (nstack.size() > 0) {
1182 dead = nstack.pop();
1183 if (dead->outcnt() > 0) {
1184 // Keep dead node on stack until all uses are processed.
1185 nstack.push(dead);
1186 // For all Users of the Dead... ;-)
1187 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1188 Node* use = dead->last_out(k);
1189 igvn->hash_delete(use); // Yank from hash table prior to mod
1190 if (use->in(0) == dead) { // Found another dead node
1191 assert (!use->is_Con(), "Control for Con node should be Root node.")
1192 use->set_req(0, top); // Cut dead edge to prevent processing
1193 nstack.push(use); // the dead node again.
1194 } else { // Else found a not-dead user
1195 for (uint j = 1; j < use->req(); j++) {
1196 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1197 use->set_req(j, top);
1198 }
1199 }
1200 igvn->_worklist.push(use);
1201 }
1202 // Refresh the iterator, since any number of kills might have happened.
1203 k = dead->last_outs(kmin);
1204 }
1205 } else { // (dead->outcnt() == 0)
1206 // Done with outputs.
1207 igvn->hash_delete(dead);
1208 igvn->_worklist.remove(dead);
1209 igvn->set_type(dead, Type::TOP);
1210 if (dead->is_macro()) {
1211 igvn->C->remove_macro_node(dead);
1212 }
1213 // Kill all inputs to the dead guy
1214 for (uint i=0; i < dead->req(); i++) {
1215 Node *n = dead->in(i); // Get input to dead guy
1216 if (n != NULL && !n->is_top()) { // Input is valid?
1217 dead->set_req(i, top); // Smash input away
1218 if (n->outcnt() == 0) { // Input also goes dead?
1219 if (!n->is_Con())
1220 nstack.push(n); // Clear it out as well
1221 } else if (n->outcnt() == 1 &&
1222 n->has_special_unique_user()) {
1223 igvn->add_users_to_worklist( n );
1224 } else if (n->outcnt() <= 2 && n->is_Store()) {
1225 // Push store's uses on worklist to enable folding optimization for
1226 // store/store and store/load to the same address.
1227 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1228 // and remove_globally_dead_node().
1229 igvn->add_users_to_worklist( n );
1230 }
1231 }
1232 }
1233 } // (dead->outcnt() == 0)
1234 } // while (nstack.size() > 0) for outputs
1235 return;
1236 }
1237
1238 //------------------------------remove_dead_region-----------------------------
1239 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1240 Node *n = in(0);
1241 if( !n ) return false;
1242 // Lost control into this guy? I.e., it became unreachable?
1243 // Aggressively kill all unreachable code.
1244 if (can_reshape && n->is_top()) {
1245 kill_dead_code(this, phase->is_IterGVN());
1246 return false; // Node is dead.
1247 }
1248
1249 if( n->is_Region() && n->as_Region()->is_copy() ) {
1250 Node *m = n->nonnull_req();
1251 set_req(0, m);
1252 return true;
1253 }
1254 return false;
1255 }
1256
1257 //------------------------------Ideal_DU_postCCP-------------------------------
1258 // Idealize graph, using DU info. Must clone result into new-space
1259 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1260 return NULL; // Default to no change
1261 }
1262
1263 //------------------------------hash-------------------------------------------
1264 // Hash function over Nodes.
1265 uint Node::hash() const {
1266 uint sum = 0;
1267 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1268 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1269 return (sum>>2) + _cnt + Opcode();
1270 }
1271
1272 //------------------------------cmp--------------------------------------------
1273 // Compare special parts of simple Nodes
1274 uint Node::cmp( const Node &n ) const {
1275 return 1; // Must be same
1276 }
1277
1278 //------------------------------rematerialize-----------------------------------
1279 // Should we clone rather than spill this instruction?
1280 bool Node::rematerialize() const {
1281 if ( is_Mach() )
1282 return this->as_Mach()->rematerialize();
1283 else
1284 return (_flags & Flag_rematerialize) != 0;
1285 }
1286
1287 //------------------------------needs_anti_dependence_check---------------------
1288 // Nodes which use memory without consuming it, hence need antidependences.
1289 bool Node::needs_anti_dependence_check() const {
1290 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1291 return false;
1292 else
1293 return in(1)->bottom_type()->has_memory();
1294 }
1295
1296
1297 // Get an integer constant from a ConNode (or CastIINode).
1298 // Return a default value if there is no apparent constant here.
1299 const TypeInt* Node::find_int_type() const {
1300 if (this->is_Type()) {
1301 return this->as_Type()->type()->isa_int();
1302 } else if (this->is_Con()) {
1303 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1304 return this->bottom_type()->isa_int();
1305 }
1306 return NULL;
1307 }
1308
1309 // Get a pointer constant from a ConstNode.
1310 // Returns the constant if it is a pointer ConstNode
1311 intptr_t Node::get_ptr() const {
1312 assert( Opcode() == Op_ConP, "" );
1313 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1314 }
1315
1316 // Get a narrow oop constant from a ConNNode.
1317 intptr_t Node::get_narrowcon() const {
1318 assert( Opcode() == Op_ConN, "" );
1319 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1320 }
1321
1322 // Get a long constant from a ConNode.
1323 // Return a default value if there is no apparent constant here.
1324 const TypeLong* Node::find_long_type() const {
1325 if (this->is_Type()) {
1326 return this->as_Type()->type()->isa_long();
1327 } else if (this->is_Con()) {
1328 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1329 return this->bottom_type()->isa_long();
1330 }
1331 return NULL;
1332 }
1333
1334 // Get a double constant from a ConstNode.
1335 // Returns the constant if it is a double ConstNode
1336 jdouble Node::getd() const {
1337 assert( Opcode() == Op_ConD, "" );
1338 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1339 }
1340
1341 // Get a float constant from a ConstNode.
1342 // Returns the constant if it is a float ConstNode
1343 jfloat Node::getf() const {
1344 assert( Opcode() == Op_ConF, "" );
1345 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1346 }
1347
1348 #ifndef PRODUCT
1349
1350 //----------------------------NotANode----------------------------------------
1351 // Used in debugging code to avoid walking across dead or uninitialized edges.
1352 static inline bool NotANode(const Node* n) {
1353 if (n == NULL) return true;
1354 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1355 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1356 return false;
1357 }
1358
1359
1360 //------------------------------find------------------------------------------
1361 // Find a neighbor of this Node with the given _idx
1362 // If idx is negative, find its absolute value, following both _in and _out.
1363 static void find_recur( Node* &result, Node *n, int idx, bool only_ctrl,
1364 VectorSet &old_space, VectorSet &new_space ) {
1365 int node_idx = (idx >= 0) ? idx : -idx;
1366 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1367 // Contained in new_space or old_space?
1368 VectorSet *v = Compile::current()->node_arena()->contains(n) ? &new_space : &old_space;
1369 if( v->test(n->_idx) ) return;
1370 if( (int)n->_idx == node_idx
1371 debug_only(|| n->debug_idx() == node_idx) ) {
1372 if (result != NULL)
1373 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1374 (uintptr_t)result, (uintptr_t)n, node_idx);
1375 result = n;
1376 }
1377 v->set(n->_idx);
1378 for( uint i=0; i<n->len(); i++ ) {
1379 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1380 find_recur( result, n->in(i), idx, only_ctrl, old_space, new_space );
1381 }
1382 // Search along forward edges also:
1383 if (idx < 0 && !only_ctrl) {
1384 for( uint j=0; j<n->outcnt(); j++ ) {
1385 find_recur( result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1386 }
1387 }
1388 #ifdef ASSERT
1389 // Search along debug_orig edges last:
1390 for (Node* orig = n->debug_orig(); orig != NULL && n != orig; orig = orig->debug_orig()) {
1391 if (NotANode(orig)) break;
1392 find_recur( result, orig, idx, only_ctrl, old_space, new_space );
1393 }
1394 #endif //ASSERT
1395 }
1396
1397 // call this from debugger:
1398 Node* find_node(Node* n, int idx) {
1399 return n->find(idx);
1400 }
1401
1402 //------------------------------find-------------------------------------------
1403 Node* Node::find(int idx) const {
1404 ResourceArea *area = Thread::current()->resource_area();
1405 VectorSet old_space(area), new_space(area);
1406 Node* result = NULL;
1407 find_recur( result, (Node*) this, idx, false, old_space, new_space );
1408 return result;
1409 }
1410
1411 //------------------------------find_ctrl--------------------------------------
1412 // Find an ancestor to this node in the control history with given _idx
1413 Node* Node::find_ctrl(int idx) const {
1414 ResourceArea *area = Thread::current()->resource_area();
1415 VectorSet old_space(area), new_space(area);
1416 Node* result = NULL;
1417 find_recur( result, (Node*) this, idx, true, old_space, new_space );
1418 return result;
1419 }
1420 #endif
1421
1422
1423
1424 #ifndef PRODUCT
1425 int Node::_in_dump_cnt = 0;
1426
1427 // -----------------------------Name-------------------------------------------
1428 extern const char *NodeClassNames[];
1429 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1430
1431 static bool is_disconnected(const Node* n) {
1432 for (uint i = 0; i < n->req(); i++) {
1433 if (n->in(i) != NULL) return false;
1434 }
1435 return true;
1436 }
1437
1438 #ifdef ASSERT
1439 static void dump_orig(Node* orig) {
1440 Compile* C = Compile::current();
1441 if (NotANode(orig)) orig = NULL;
1442 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1443 if (orig == NULL) return;
1444 tty->print(" !orig=");
1445 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1446 if (NotANode(fast)) fast = NULL;
1447 while (orig != NULL) {
1448 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1449 if (discon) tty->print("[");
1450 if (!Compile::current()->node_arena()->contains(orig))
1451 tty->print("o");
1452 tty->print("%d", orig->_idx);
1453 if (discon) tty->print("]");
1454 orig = orig->debug_orig();
1455 if (NotANode(orig)) orig = NULL;
1456 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1457 if (orig != NULL) tty->print(",");
1458 if (fast != NULL) {
1459 // Step fast twice for each single step of orig:
1460 fast = fast->debug_orig();
1461 if (NotANode(fast)) fast = NULL;
1462 if (fast != NULL && fast != orig) {
1463 fast = fast->debug_orig();
1464 if (NotANode(fast)) fast = NULL;
1465 }
1466 if (fast == orig) {
1467 tty->print("...");
1468 break;
1469 }
1470 }
1471 }
1472 }
1473
1474 void Node::set_debug_orig(Node* orig) {
1475 _debug_orig = orig;
1476 if (BreakAtNode == 0) return;
1477 if (NotANode(orig)) orig = NULL;
1478 int trip = 10;
1479 while (orig != NULL) {
1480 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1481 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1482 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1483 BREAKPOINT;
1484 }
1485 orig = orig->debug_orig();
1486 if (NotANode(orig)) orig = NULL;
1487 if (trip-- <= 0) break;
1488 }
1489 }
1490 #endif //ASSERT
1491
1492 //------------------------------dump------------------------------------------
1493 // Dump a Node
1494 void Node::dump() const {
1495 Compile* C = Compile::current();
1496 bool is_new = C->node_arena()->contains(this);
1497 _in_dump_cnt++;
1498 tty->print("%c%d\t%s\t=== ",
1499 is_new ? ' ' : 'o', _idx, Name());
1500
1501 // Dump the required and precedence inputs
1502 dump_req();
1503 dump_prec();
1504 // Dump the outputs
1505 dump_out();
1506
1507 if (is_disconnected(this)) {
1508 #ifdef ASSERT
1509 tty->print(" [%d]",debug_idx());
1510 dump_orig(debug_orig());
1511 #endif
1512 tty->cr();
1513 _in_dump_cnt--;
1514 return; // don't process dead nodes
1515 }
1516
1517 // Dump node-specific info
1518 dump_spec(tty);
1519 #ifdef ASSERT
1520 // Dump the non-reset _debug_idx
1521 if( Verbose && WizardMode ) {
1522 tty->print(" [%d]",debug_idx());
1523 }
1524 #endif
1525
1526 const Type *t = bottom_type();
1527
1528 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1529 const TypeInstPtr *toop = t->isa_instptr();
1530 const TypeKlassPtr *tkls = t->isa_klassptr();
1531 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1532 if( klass && klass->is_loaded() && klass->is_interface() ) {
1533 tty->print(" Interface:");
1534 } else if( toop ) {
1535 tty->print(" Oop:");
1536 } else if( tkls ) {
1537 tty->print(" Klass:");
1538 }
1539 t->dump();
1540 } else if( t == Type::MEMORY ) {
1541 tty->print(" Memory:");
1542 MemNode::dump_adr_type(this, adr_type(), tty);
1543 } else if( Verbose || WizardMode ) {
1544 tty->print(" Type:");
1545 if( t ) {
1546 t->dump();
1547 } else {
1548 tty->print("no type");
1549 }
1550 }
1551 if (is_new) {
1552 debug_only(dump_orig(debug_orig()));
1553 Node_Notes* nn = C->node_notes_at(_idx);
1554 if (nn != NULL && !nn->is_clear()) {
1555 if (nn->jvms() != NULL) {
1556 tty->print(" !jvms:");
1557 nn->jvms()->dump_spec(tty);
1558 }
1559 }
1560 }
1561 tty->cr();
1562 _in_dump_cnt--;
1563 }
1564
1565 //------------------------------dump_req--------------------------------------
1566 void Node::dump_req() const {
1567 // Dump the required input edges
1568 for (uint i = 0; i < req(); i++) { // For all required inputs
1569 Node* d = in(i);
1570 if (d == NULL) {
1571 tty->print("_ ");
1572 } else if (NotANode(d)) {
1573 tty->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1574 } else {
1575 tty->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1576 }
1577 }
1578 }
1579
1580
1581 //------------------------------dump_prec-------------------------------------
1582 void Node::dump_prec() const {
1583 // Dump the precedence edges
1584 int any_prec = 0;
1585 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1586 Node* p = in(i);
1587 if (p != NULL) {
1588 if( !any_prec++ ) tty->print(" |");
1589 if (NotANode(p)) { tty->print("NotANode "); continue; }
1590 tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1591 }
1592 }
1593 }
1594
1595 //------------------------------dump_out--------------------------------------
1596 void Node::dump_out() const {
1597 // Delimit the output edges
1598 tty->print(" [[");
1599 // Dump the output edges
1600 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1601 Node* u = _out[i];
1602 if (u == NULL) {
1603 tty->print("_ ");
1604 } else if (NotANode(u)) {
1605 tty->print("NotANode ");
1606 } else {
1607 tty->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1608 }
1609 }
1610 tty->print("]] ");
1611 }
1612
1613 //------------------------------dump_nodes-------------------------------------
1614 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1615 Node* s = (Node*)start; // remove const
1616 if (NotANode(s)) return;
1617
1618 uint depth = (uint)ABS(d);
1619 int direction = d;
1620 Compile* C = Compile::current();
1621 GrowableArray <Node *> nstack(C->unique());
1622
1623 nstack.append(s);
1624 int begin = 0;
1625 int end = 0;
1626 for(uint i = 0; i < depth; i++) {
1627 end = nstack.length();
1628 for(int j = begin; j < end; j++) {
1629 Node* tp = nstack.at(j);
1630 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1631 for(uint k = 0; k < limit; k++) {
1632 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1633
1634 if (NotANode(n)) continue;
1635 // do not recurse through top or the root (would reach unrelated stuff)
1636 if (n->is_Root() || n->is_top()) continue;
1637 if (only_ctrl && !n->is_CFG()) continue;
1638
1639 bool on_stack = nstack.contains(n);
1640 if (!on_stack) {
1641 nstack.append(n);
1642 }
1643 }
1644 }
1645 begin = end;
1646 }
1647 end = nstack.length();
1648 if (direction > 0) {
1649 for(int j = end-1; j >= 0; j--) {
1650 nstack.at(j)->dump();
1651 }
1652 } else {
1653 for(int j = 0; j < end; j++) {
1654 nstack.at(j)->dump();
1655 }
1656 }
1657 }
1658
1659 //------------------------------dump-------------------------------------------
1660 void Node::dump(int d) const {
1661 dump_nodes(this, d, false);
1662 }
1663
1664 //------------------------------dump_ctrl--------------------------------------
1665 // Dump a Node's control history to depth
1666 void Node::dump_ctrl(int d) const {
1667 dump_nodes(this, d, true);
1668 }
1669
1670 // VERIFICATION CODE
1671 // For each input edge to a node (ie - for each Use-Def edge), verify that
1672 // there is a corresponding Def-Use edge.
1673 //------------------------------verify_edges-----------------------------------
1674 void Node::verify_edges(Unique_Node_List &visited) {
1675 uint i, j, idx;
1676 int cnt;
1677 Node *n;
1678
1679 // Recursive termination test
1680 if (visited.member(this)) return;
1681 visited.push(this);
1682
1683 // Walk over all input edges, checking for correspondence
1684 for( i = 0; i < len(); i++ ) {
1685 n = in(i);
1686 if (n != NULL && !n->is_top()) {
1687 // Count instances of (Node *)this
1688 cnt = 0;
1689 for (idx = 0; idx < n->_outcnt; idx++ ) {
1690 if (n->_out[idx] == (Node *)this) cnt++;
1691 }
1692 assert( cnt > 0,"Failed to find Def-Use edge." );
1693 // Check for duplicate edges
1694 // walk the input array downcounting the input edges to n
1695 for( j = 0; j < len(); j++ ) {
1696 if( in(j) == n ) cnt--;
1697 }
1698 assert( cnt == 0,"Mismatched edge count.");
1699 } else if (n == NULL) {
1700 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1701 } else {
1702 assert(n->is_top(), "sanity");
1703 // Nothing to check.
1704 }
1705 }
1706 // Recursive walk over all input edges
1707 for( i = 0; i < len(); i++ ) {
1708 n = in(i);
1709 if( n != NULL )
1710 in(i)->verify_edges(visited);
1711 }
1712 }
1713
1714 //------------------------------verify_recur-----------------------------------
1715 static const Node *unique_top = NULL;
1716
1717 void Node::verify_recur(const Node *n, int verify_depth,
1718 VectorSet &old_space, VectorSet &new_space) {
1719 if ( verify_depth == 0 ) return;
1720 if (verify_depth > 0) --verify_depth;
1721
1722 Compile* C = Compile::current();
1723
1724 // Contained in new_space or old_space?
1725 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1726 // Check for visited in the proper space. Numberings are not unique
1727 // across spaces so we need a separate VectorSet for each space.
1728 if( v->test_set(n->_idx) ) return;
1729
1730 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1731 if (C->cached_top_node() == NULL)
1732 C->set_cached_top_node((Node*)n);
1733 assert(C->cached_top_node() == n, "TOP node must be unique");
1734 }
1735
1736 for( uint i = 0; i < n->len(); i++ ) {
1737 Node *x = n->in(i);
1738 if (!x || x->is_top()) continue;
1739
1740 // Verify my input has a def-use edge to me
1741 if (true /*VerifyDefUse*/) {
1742 // Count use-def edges from n to x
1743 int cnt = 0;
1744 for( uint j = 0; j < n->len(); j++ )
1745 if( n->in(j) == x )
1746 cnt++;
1747 // Count def-use edges from x to n
1748 uint max = x->_outcnt;
1749 for( uint k = 0; k < max; k++ )
1750 if (x->_out[k] == n)
1751 cnt--;
1752 assert( cnt == 0, "mismatched def-use edge counts" );
1753 }
1754
1755 verify_recur(x, verify_depth, old_space, new_space);
1756 }
1757
1758 }
1759
1760 //------------------------------verify-----------------------------------------
1761 // Check Def-Use info for my subgraph
1762 void Node::verify() const {
1763 Compile* C = Compile::current();
1764 Node* old_top = C->cached_top_node();
1765 ResourceMark rm;
1766 ResourceArea *area = Thread::current()->resource_area();
1767 VectorSet old_space(area), new_space(area);
1768 verify_recur(this, -1, old_space, new_space);
1769 C->set_cached_top_node(old_top);
1770 }
1771 #endif
1772
1773
1774 //------------------------------walk-------------------------------------------
1775 // Graph walk, with both pre-order and post-order functions
1776 void Node::walk(NFunc pre, NFunc post, void *env) {
1777 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1778 walk_(pre, post, env, visited);
1779 }
1780
1781 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1782 if( visited.test_set(_idx) ) return;
1783 pre(*this,env); // Call the pre-order walk function
1784 for( uint i=0; i<_max; i++ )
1785 if( in(i) ) // Input exists and is not walked?
1786 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1787 post(*this,env); // Call the post-order walk function
1788 }
1789
1790 void Node::nop(Node &, void*) {}
1791
1792 //------------------------------Registers--------------------------------------
1793 // Do we Match on this edge index or not? Generally false for Control
1794 // and true for everything else. Weird for calls & returns.
1795 uint Node::match_edge(uint idx) const {
1796 return idx; // True for other than index 0 (control)
1797 }
1798
1799 // Register classes are defined for specific machines
1800 const RegMask &Node::out_RegMask() const {
1801 ShouldNotCallThis();
1802 return *(new RegMask());
1803 }
1804
1805 const RegMask &Node::in_RegMask(uint) const {
1806 ShouldNotCallThis();
1807 return *(new RegMask());
1808 }
1809
1810 //=============================================================================
1811 //-----------------------------------------------------------------------------
1812 void Node_Array::reset( Arena *new_arena ) {
1813 _a->Afree(_nodes,_max*sizeof(Node*));
1814 _max = 0;
1815 _nodes = NULL;
1816 _a = new_arena;
1817 }
1818
1819 //------------------------------clear------------------------------------------
1820 // Clear all entries in _nodes to NULL but keep storage
1821 void Node_Array::clear() {
1822 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1823 }
1824
1825 //-----------------------------------------------------------------------------
1826 void Node_Array::grow( uint i ) {
1827 if( !_max ) {
1828 _max = 1;
1829 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1830 _nodes[0] = NULL;
1831 }
1832 uint old = _max;
1833 while( i >= _max ) _max <<= 1; // Double to fit
1834 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1835 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1836 }
1837
1838 //-----------------------------------------------------------------------------
1839 void Node_Array::insert( uint i, Node *n ) {
1840 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1841 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1842 _nodes[i] = n;
1843 }
1844
1845 //-----------------------------------------------------------------------------
1846 void Node_Array::remove( uint i ) {
1847 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1848 _nodes[_max-1] = NULL;
1849 }
1850
1851 //-----------------------------------------------------------------------------
1852 void Node_Array::sort( C_sort_func_t func) {
1853 qsort( _nodes, _max, sizeof( Node* ), func );
1854 }
1855
1856 //-----------------------------------------------------------------------------
1857 void Node_Array::dump() const {
1858 #ifndef PRODUCT
1859 for( uint i = 0; i < _max; i++ ) {
1860 Node *nn = _nodes[i];
1861 if( nn != NULL ) {
1862 tty->print("%5d--> ",i); nn->dump();
1863 }
1864 }
1865 #endif
1866 }
1867
1868 //--------------------------is_iteratively_computed------------------------------
1869 // Operation appears to be iteratively computed (such as an induction variable)
1870 // It is possible for this operation to return false for a loop-varying
1871 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1872 bool Node::is_iteratively_computed() {
1873 if (ideal_reg()) { // does operation have a result register?
1874 for (uint i = 1; i < req(); i++) {
1875 Node* n = in(i);
1876 if (n != NULL && n->is_Phi()) {
1877 for (uint j = 1; j < n->req(); j++) {
1878 if (n->in(j) == this) {
1879 return true;
1880 }
1881 }
1882 }
1883 }
1884 }
1885 return false;
1886 }
1887
1888 //--------------------------find_similar------------------------------
1889 // Return a node with opcode "opc" and same inputs as "this" if one can
1890 // be found; Otherwise return NULL;
1891 Node* Node::find_similar(int opc) {
1892 if (req() >= 2) {
1893 Node* def = in(1);
1894 if (def && def->outcnt() >= 2) {
1895 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
1896 Node* use = def->fast_out(i);
1897 if (use->Opcode() == opc &&
1898 use->req() == req()) {
1899 uint j;
1900 for (j = 0; j < use->req(); j++) {
1901 if (use->in(j) != in(j)) {
1902 break;
1903 }
1904 }
1905 if (j == use->req()) {
1906 return use;
1907 }
1908 }
1909 }
1910 }
1911 }
1912 return NULL;
1913 }
1914
1915
1916 //--------------------------unique_ctrl_out------------------------------
1917 // Return the unique control out if only one. Null if none or more than one.
1918 Node* Node::unique_ctrl_out() {
1919 Node* found = NULL;
1920 for (uint i = 0; i < outcnt(); i++) {
1921 Node* use = raw_out(i);
1922 if (use->is_CFG() && use != this) {
1923 if (found != NULL) return NULL;
1924 found = use;
1925 }
1926 }
1927 return found;
1928 }
1929
1930 //=============================================================================
1931 //------------------------------yank-------------------------------------------
1932 // Find and remove
1933 void Node_List::yank( Node *n ) {
1934 uint i;
1935 for( i = 0; i < _cnt; i++ )
1936 if( _nodes[i] == n )
1937 break;
1938
1939 if( i < _cnt )
1940 _nodes[i] = _nodes[--_cnt];
1941 }
1942
1943 //------------------------------dump-------------------------------------------
1944 void Node_List::dump() const {
1945 #ifndef PRODUCT
1946 for( uint i = 0; i < _cnt; i++ )
1947 if( _nodes[i] ) {
1948 tty->print("%5d--> ",i);
1949 _nodes[i]->dump();
1950 }
1951 #endif
1952 }
1953
1954 //=============================================================================
1955 //------------------------------remove-----------------------------------------
1956 void Unique_Node_List::remove( Node *n ) {
1957 if( _in_worklist[n->_idx] ) {
1958 for( uint i = 0; i < size(); i++ )
1959 if( _nodes[i] == n ) {
1960 map(i,Node_List::pop());
1961 _in_worklist >>= n->_idx;
1962 return;
1963 }
1964 ShouldNotReachHere();
1965 }
1966 }
1967
1968 //-----------------------remove_useless_nodes----------------------------------
1969 // Remove useless nodes from worklist
1970 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
1971
1972 for( uint i = 0; i < size(); ++i ) {
1973 Node *n = at(i);
1974 assert( n != NULL, "Did not expect null entries in worklist");
1975 if( ! useful.test(n->_idx) ) {
1976 _in_worklist >>= n->_idx;
1977 map(i,Node_List::pop());
1978 // Node *replacement = Node_List::pop();
1979 // if( i != size() ) { // Check if removing last entry
1980 // _nodes[i] = replacement;
1981 // }
1982 --i; // Visit popped node
1983 // If it was last entry, loop terminates since size() was also reduced
1984 }
1985 }
1986 }
1987
1988 //=============================================================================
1989 void Node_Stack::grow() {
1990 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
1991 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
1992 size_t max = old_max << 1; // max * 2
1993 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
1994 _inode_max = _inodes + max;
1995 _inode_top = _inodes + old_top; // restore _top
1996 }
1997
1998 //=============================================================================
1999 uint TypeNode::size_of() const { return sizeof(*this); }
2000 #ifndef PRODUCT
2001 void TypeNode::dump_spec(outputStream *st) const {
2002 if( !Verbose && !WizardMode ) {
2003 // standard dump does this in Verbose and WizardMode
2004 st->print(" #"); _type->dump_on(st);
2005 }
2006 }
2007 #endif
2008 uint TypeNode::hash() const {
2009 return Node::hash() + _type->hash();
2010 }
2011 uint TypeNode::cmp( const Node &n ) const
2012 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2013 const Type *TypeNode::bottom_type() const { return _type; }
2014 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2015
2016 //------------------------------ideal_reg--------------------------------------
2017 uint TypeNode::ideal_reg() const {
2018 return Matcher::base2reg[_type->base()];
2019 }