1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/castnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/connode.hpp"
34 #include "opto/loopnode.hpp"
35 #include "opto/machnode.hpp"
36 #include "opto/matcher.hpp"
37 #include "opto/node.hpp"
38 #include "opto/opcodes.hpp"
39 #include "opto/regmask.hpp"
40 #include "opto/type.hpp"
41 #include "utilities/copy.hpp"
42 #include "utilities/macros.hpp"
43
44 class RegMask;
45 // #include "phase.hpp"
46 class PhaseTransform;
47 class PhaseGVN;
48
49 // Arena we are currently building Nodes in
50 const uint Node::NotAMachineReg = 0xffff0000;
51
52 #ifndef PRODUCT
53 extern int nodes_created;
54 #endif
55 #ifdef __clang__
56 #pragma clang diagnostic push
57 #pragma GCC diagnostic ignored "-Wuninitialized"
58 #endif
59
60 #ifdef ASSERT
61
62 //-------------------------- construct_node------------------------------------
63 // Set a breakpoint here to identify where a particular node index is built.
64 void Node::verify_construction() {
65 _debug_orig = NULL;
66 int old_debug_idx = Compile::debug_idx();
67 int new_debug_idx = old_debug_idx+1;
68 if (new_debug_idx > 0) {
69 // Arrange that the lowest five decimal digits of _debug_idx
70 // will repeat those of _idx. In case this is somehow pathological,
71 // we continue to assign negative numbers (!) consecutively.
72 const int mod = 100000;
73 int bump = (int)(_idx - new_debug_idx) % mod;
74 if (bump < 0) bump += mod;
75 assert(bump >= 0 && bump < mod, "");
76 new_debug_idx += bump;
77 }
78 Compile::set_debug_idx(new_debug_idx);
79 set_debug_idx( new_debug_idx );
80 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
81 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
82 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
83 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
84 BREAKPOINT;
85 }
86 #if OPTO_DU_ITERATOR_ASSERT
87 _last_del = NULL;
88 _del_tick = 0;
89 #endif
90 _hash_lock = 0;
91 }
92
93
94 // #ifdef ASSERT ...
95
96 #if OPTO_DU_ITERATOR_ASSERT
97 void DUIterator_Common::sample(const Node* node) {
98 _vdui = VerifyDUIterators;
99 _node = node;
100 _outcnt = node->_outcnt;
101 _del_tick = node->_del_tick;
102 _last = NULL;
103 }
104
105 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
106 assert(_node == node, "consistent iterator source");
107 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
108 }
109
110 void DUIterator_Common::verify_resync() {
111 // Ensure that the loop body has just deleted the last guy produced.
112 const Node* node = _node;
113 // Ensure that at least one copy of the last-seen edge was deleted.
114 // Note: It is OK to delete multiple copies of the last-seen edge.
115 // Unfortunately, we have no way to verify that all the deletions delete
116 // that same edge. On this point we must use the Honor System.
117 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
118 assert(node->_last_del == _last, "must have deleted the edge just produced");
119 // We liked this deletion, so accept the resulting outcnt and tick.
120 _outcnt = node->_outcnt;
121 _del_tick = node->_del_tick;
122 }
123
124 void DUIterator_Common::reset(const DUIterator_Common& that) {
125 if (this == &that) return; // ignore assignment to self
126 if (!_vdui) {
127 // We need to initialize everything, overwriting garbage values.
128 _last = that._last;
129 _vdui = that._vdui;
130 }
131 // Note: It is legal (though odd) for an iterator over some node x
132 // to be reassigned to iterate over another node y. Some doubly-nested
133 // progress loops depend on being able to do this.
134 const Node* node = that._node;
135 // Re-initialize everything, except _last.
136 _node = node;
137 _outcnt = node->_outcnt;
138 _del_tick = node->_del_tick;
139 }
140
141 void DUIterator::sample(const Node* node) {
142 DUIterator_Common::sample(node); // Initialize the assertion data.
143 _refresh_tick = 0; // No refreshes have happened, as yet.
144 }
145
146 void DUIterator::verify(const Node* node, bool at_end_ok) {
147 DUIterator_Common::verify(node, at_end_ok);
148 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
149 }
150
151 void DUIterator::verify_increment() {
152 if (_refresh_tick & 1) {
153 // We have refreshed the index during this loop.
154 // Fix up _idx to meet asserts.
155 if (_idx > _outcnt) _idx = _outcnt;
156 }
157 verify(_node, true);
158 }
159
160 void DUIterator::verify_resync() {
161 // Note: We do not assert on _outcnt, because insertions are OK here.
162 DUIterator_Common::verify_resync();
163 // Make sure we are still in sync, possibly with no more out-edges:
164 verify(_node, true);
165 }
166
167 void DUIterator::reset(const DUIterator& that) {
168 if (this == &that) return; // self assignment is always a no-op
169 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
170 assert(that._idx == 0, "assign only the result of Node::outs()");
171 assert(_idx == that._idx, "already assigned _idx");
172 if (!_vdui) {
173 // We need to initialize everything, overwriting garbage values.
174 sample(that._node);
175 } else {
176 DUIterator_Common::reset(that);
177 if (_refresh_tick & 1) {
178 _refresh_tick++; // Clear the "was refreshed" flag.
179 }
180 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
181 }
182 }
183
184 void DUIterator::refresh() {
185 DUIterator_Common::sample(_node); // Re-fetch assertion data.
186 _refresh_tick |= 1; // Set the "was refreshed" flag.
187 }
188
189 void DUIterator::verify_finish() {
190 // If the loop has killed the node, do not require it to re-run.
191 if (_node->_outcnt == 0) _refresh_tick &= ~1;
192 // If this assert triggers, it means that a loop used refresh_out_pos
193 // to re-synch an iteration index, but the loop did not correctly
194 // re-run itself, using a "while (progress)" construct.
195 // This iterator enforces the rule that you must keep trying the loop
196 // until it "runs clean" without any need for refreshing.
197 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
198 }
199
200
201 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
202 DUIterator_Common::verify(node, at_end_ok);
203 Node** out = node->_out;
204 uint cnt = node->_outcnt;
205 assert(cnt == _outcnt, "no insertions allowed");
206 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
207 // This last check is carefully designed to work for NO_OUT_ARRAY.
208 }
209
210 void DUIterator_Fast::verify_limit() {
211 const Node* node = _node;
212 verify(node, true);
213 assert(_outp == node->_out + node->_outcnt, "limit still correct");
214 }
215
216 void DUIterator_Fast::verify_resync() {
217 const Node* node = _node;
218 if (_outp == node->_out + _outcnt) {
219 // Note that the limit imax, not the pointer i, gets updated with the
220 // exact count of deletions. (For the pointer it's always "--i".)
221 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
222 // This is a limit pointer, with a name like "imax".
223 // Fudge the _last field so that the common assert will be happy.
224 _last = (Node*) node->_last_del;
225 DUIterator_Common::verify_resync();
226 } else {
227 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
228 // A normal internal pointer.
229 DUIterator_Common::verify_resync();
230 // Make sure we are still in sync, possibly with no more out-edges:
231 verify(node, true);
232 }
233 }
234
235 void DUIterator_Fast::verify_relimit(uint n) {
236 const Node* node = _node;
237 assert((int)n > 0, "use imax -= n only with a positive count");
238 // This must be a limit pointer, with a name like "imax".
239 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
240 // The reported number of deletions must match what the node saw.
241 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
242 // Fudge the _last field so that the common assert will be happy.
243 _last = (Node*) node->_last_del;
244 DUIterator_Common::verify_resync();
245 }
246
247 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
248 assert(_outp == that._outp, "already assigned _outp");
249 DUIterator_Common::reset(that);
250 }
251
252 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
253 // at_end_ok means the _outp is allowed to underflow by 1
254 _outp += at_end_ok;
255 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
256 _outp -= at_end_ok;
257 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
258 }
259
260 void DUIterator_Last::verify_limit() {
261 // Do not require the limit address to be resynched.
262 //verify(node, true);
263 assert(_outp == _node->_out, "limit still correct");
264 }
265
266 void DUIterator_Last::verify_step(uint num_edges) {
267 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
268 _outcnt -= num_edges;
269 _del_tick += num_edges;
270 // Make sure we are still in sync, possibly with no more out-edges:
271 const Node* node = _node;
272 verify(node, true);
273 assert(node->_last_del == _last, "must have deleted the edge just produced");
274 }
275
276 #endif //OPTO_DU_ITERATOR_ASSERT
277
278
279 #endif //ASSERT
280
281
282 // This constant used to initialize _out may be any non-null value.
283 // The value NULL is reserved for the top node only.
284 #define NO_OUT_ARRAY ((Node**)-1)
285
286 // Out-of-line code from node constructors.
287 // Executed only when extra debug info. is being passed around.
288 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
289 C->set_node_notes_at(idx, nn);
290 }
291
292 // Shared initialization code.
293 inline int Node::Init(int req) {
294 Compile* C = Compile::current();
295 int idx = C->next_unique();
296
297 // Allocate memory for the necessary number of edges.
298 if (req > 0) {
299 // Allocate space for _in array to have double alignment.
300 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
301 }
302 // If there are default notes floating around, capture them:
303 Node_Notes* nn = C->default_node_notes();
304 if (nn != NULL) init_node_notes(C, idx, nn);
305
306 // Note: At this point, C is dead,
307 // and we begin to initialize the new Node.
308
309 _cnt = _max = req;
310 _outcnt = _outmax = 0;
311 _class_id = Class_Node;
312 _flags = 0;
313 _out = NO_OUT_ARRAY;
314 return idx;
315 }
316
317 //------------------------------Node-------------------------------------------
318 // Create a Node, with a given number of required edges.
319 Node::Node(uint req)
320 : _idx(Init(req))
321 #ifdef ASSERT
322 , _parse_idx(_idx)
323 #endif
324 {
325 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
326 debug_only( verify_construction() );
327 NOT_PRODUCT(nodes_created++);
328 if (req == 0) {
329 _in = NULL;
330 } else {
331 Node** to = _in;
332 for(uint i = 0; i < req; i++) {
333 to[i] = NULL;
334 }
335 }
336 }
337
338 //------------------------------Node-------------------------------------------
339 Node::Node(Node *n0)
340 : _idx(Init(1))
341 #ifdef ASSERT
342 , _parse_idx(_idx)
343 #endif
344 {
345 debug_only( verify_construction() );
346 NOT_PRODUCT(nodes_created++);
347 assert( is_not_dead(n0), "can not use dead node");
348 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
349 }
350
351 //------------------------------Node-------------------------------------------
352 Node::Node(Node *n0, Node *n1)
353 : _idx(Init(2))
354 #ifdef ASSERT
355 , _parse_idx(_idx)
356 #endif
357 {
358 debug_only( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 assert( is_not_dead(n0), "can not use dead node");
361 assert( is_not_dead(n1), "can not use dead node");
362 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
363 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
364 }
365
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1, Node *n2)
368 : _idx(Init(3))
369 #ifdef ASSERT
370 , _parse_idx(_idx)
371 #endif
372 {
373 debug_only( verify_construction() );
374 NOT_PRODUCT(nodes_created++);
375 assert( is_not_dead(n0), "can not use dead node");
376 assert( is_not_dead(n1), "can not use dead node");
377 assert( is_not_dead(n2), "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 }
382
383 //------------------------------Node-------------------------------------------
384 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
385 : _idx(Init(4))
386 #ifdef ASSERT
387 , _parse_idx(_idx)
388 #endif
389 {
390 debug_only( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
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 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
397 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
398 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
399 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
400 }
401
402 //------------------------------Node-------------------------------------------
403 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
404 : _idx(Init(5))
405 #ifdef ASSERT
406 , _parse_idx(_idx)
407 #endif
408 {
409 debug_only( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 assert( is_not_dead(n0), "can not use dead node");
412 assert( is_not_dead(n1), "can not use dead node");
413 assert( is_not_dead(n2), "can not use dead node");
414 assert( is_not_dead(n3), "can not use dead node");
415 assert( is_not_dead(n4), "can not use dead node");
416 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
417 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
418 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
419 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
420 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
421 }
422
423 //------------------------------Node-------------------------------------------
424 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
425 Node *n4, Node *n5)
426 : _idx(Init(6))
427 #ifdef ASSERT
428 , _parse_idx(_idx)
429 #endif
430 {
431 debug_only( verify_construction() );
432 NOT_PRODUCT(nodes_created++);
433 assert( is_not_dead(n0), "can not use dead node");
434 assert( is_not_dead(n1), "can not use dead node");
435 assert( is_not_dead(n2), "can not use dead node");
436 assert( is_not_dead(n3), "can not use dead node");
437 assert( is_not_dead(n4), "can not use dead node");
438 assert( is_not_dead(n5), "can not use dead node");
439 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
444 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
445 }
446
447 //------------------------------Node-------------------------------------------
448 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
449 Node *n4, Node *n5, Node *n6)
450 : _idx(Init(7))
451 #ifdef ASSERT
452 , _parse_idx(_idx)
453 #endif
454 {
455 debug_only( verify_construction() );
456 NOT_PRODUCT(nodes_created++);
457 assert( is_not_dead(n0), "can not use dead node");
458 assert( is_not_dead(n1), "can not use dead node");
459 assert( is_not_dead(n2), "can not use dead node");
460 assert( is_not_dead(n3), "can not use dead node");
461 assert( is_not_dead(n4), "can not use dead node");
462 assert( is_not_dead(n5), "can not use dead node");
463 assert( is_not_dead(n6), "can not use dead node");
464 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
465 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
466 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
467 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
468 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
469 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
470 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
471 }
472
473 #ifdef __clang__
474 #pragma clang diagnostic pop
475 #endif
476
477
478 //------------------------------clone------------------------------------------
479 // Clone a Node.
480 Node *Node::clone() const {
481 Compile* C = Compile::current();
482 uint s = size_of(); // Size of inherited Node
483 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
484 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
485 // Set the new input pointer array
486 n->_in = (Node**)(((char*)n)+s);
487 // Cannot share the old output pointer array, so kill it
488 n->_out = NO_OUT_ARRAY;
489 // And reset the counters to 0
490 n->_outcnt = 0;
491 n->_outmax = 0;
492 // Unlock this guy, since he is not in any hash table.
493 debug_only(n->_hash_lock = 0);
494 // Walk the old node's input list to duplicate its edges
495 uint i;
496 for( i = 0; i < len(); i++ ) {
497 Node *x = in(i);
498 n->_in[i] = x;
499 if (x != NULL) x->add_out(n);
500 }
501 if (is_macro())
502 C->add_macro_node(n);
503 if (is_expensive())
504 C->add_expensive_node(n);
505 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
506 bs->register_potential_barrier_node(n);
507 // If the cloned node is a range check dependent CastII, add it to the list.
508 CastIINode* cast = n->isa_CastII();
509 if (cast != NULL && cast->has_range_check()) {
510 C->add_range_check_cast(cast);
511 }
512 if (n->Opcode() == Op_Opaque4) {
513 C->add_opaque4_node(n);
514 }
515
516 n->set_idx(C->next_unique()); // Get new unique index as well
517 debug_only( n->verify_construction() );
518 NOT_PRODUCT(nodes_created++);
519 // Do not patch over the debug_idx of a clone, because it makes it
520 // impossible to break on the clone's moment of creation.
521 //debug_only( n->set_debug_idx( debug_idx() ) );
522
523 C->copy_node_notes_to(n, (Node*) this);
524
525 // MachNode clone
526 uint nopnds;
527 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
528 MachNode *mach = n->as_Mach();
529 MachNode *mthis = this->as_Mach();
530 // Get address of _opnd_array.
531 // It should be the same offset since it is the clone of this node.
532 MachOper **from = mthis->_opnds;
533 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
534 pointer_delta((const void*)from,
535 (const void*)(&mthis->_opnds), 1));
536 mach->_opnds = to;
537 for ( uint i = 0; i < nopnds; ++i ) {
538 to[i] = from[i]->clone();
539 }
540 }
541 // cloning CallNode may need to clone JVMState
542 if (n->is_Call()) {
543 n->as_Call()->clone_jvms(C);
544 }
545 if (n->is_SafePoint()) {
546 n->as_SafePoint()->clone_replaced_nodes();
547 }
548 return n; // Return the clone
549 }
550
551 //---------------------------setup_is_top--------------------------------------
552 // Call this when changing the top node, to reassert the invariants
553 // required by Node::is_top. See Compile::set_cached_top_node.
554 void Node::setup_is_top() {
555 if (this == (Node*)Compile::current()->top()) {
556 // This node has just become top. Kill its out array.
557 _outcnt = _outmax = 0;
558 _out = NULL; // marker value for top
559 assert(is_top(), "must be top");
560 } else {
561 if (_out == NULL) _out = NO_OUT_ARRAY;
562 assert(!is_top(), "must not be top");
563 }
564 }
565
566
567 //------------------------------~Node------------------------------------------
568 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
569 void Node::destruct() {
570 // Eagerly reclaim unique Node numberings
571 Compile* compile = Compile::current();
572 if ((uint)_idx+1 == compile->unique()) {
573 compile->set_unique(compile->unique()-1);
574 }
575 // Clear debug info:
576 Node_Notes* nn = compile->node_notes_at(_idx);
577 if (nn != NULL) nn->clear();
578 // Walk the input array, freeing the corresponding output edges
579 _cnt = _max; // forget req/prec distinction
580 uint i;
581 for( i = 0; i < _max; i++ ) {
582 set_req(i, NULL);
583 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
584 }
585 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
586 // See if the input array was allocated just prior to the object
587 int edge_size = _max*sizeof(void*);
588 int out_edge_size = _outmax*sizeof(void*);
589 char *edge_end = ((char*)_in) + edge_size;
590 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
591 int node_size = size_of();
592
593 // Free the output edge array
594 if (out_edge_size > 0) {
595 compile->node_arena()->Afree(out_array, out_edge_size);
596 }
597
598 // Free the input edge array and the node itself
599 if( edge_end == (char*)this ) {
600 // It was; free the input array and object all in one hit
601 #ifndef ASSERT
602 compile->node_arena()->Afree(_in,edge_size+node_size);
603 #endif
604 } else {
605 // Free just the input array
606 compile->node_arena()->Afree(_in,edge_size);
607
608 // Free just the object
609 #ifndef ASSERT
610 compile->node_arena()->Afree(this,node_size);
611 #endif
612 }
613 if (is_macro()) {
614 compile->remove_macro_node(this);
615 }
616 if (is_expensive()) {
617 compile->remove_expensive_node(this);
618 }
619 CastIINode* cast = isa_CastII();
620 if (cast != NULL && cast->has_range_check()) {
621 compile->remove_range_check_cast(cast);
622 }
623 if (Opcode() == Op_Opaque4) {
624 compile->remove_opaque4_node(this);
625 }
626
627 if (is_SafePoint()) {
628 as_SafePoint()->delete_replaced_nodes();
629 }
630 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
631 bs->unregister_potential_barrier_node(this);
632 #ifdef ASSERT
633 // We will not actually delete the storage, but we'll make the node unusable.
634 *(address*)this = badAddress; // smash the C++ vtbl, probably
635 _in = _out = (Node**) badAddress;
636 _max = _cnt = _outmax = _outcnt = 0;
637 compile->remove_modified_node(this);
638 #endif
639 }
640
641 //------------------------------grow-------------------------------------------
642 // Grow the input array, making space for more edges
643 void Node::grow( uint len ) {
644 Arena* arena = Compile::current()->node_arena();
645 uint new_max = _max;
646 if( new_max == 0 ) {
647 _max = 4;
648 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
649 Node** to = _in;
650 to[0] = NULL;
651 to[1] = NULL;
652 to[2] = NULL;
653 to[3] = NULL;
654 return;
655 }
656 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
657 // Trimming to limit allows a uint8 to handle up to 255 edges.
658 // Previously I was using only powers-of-2 which peaked at 128 edges.
659 //if( new_max >= limit ) new_max = limit-1;
660 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
661 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
662 _max = new_max; // Record new max length
663 // This assertion makes sure that Node::_max is wide enough to
664 // represent the numerical value of new_max.
665 assert(_max == new_max && _max > len, "int width of _max is too small");
666 }
667
668 //-----------------------------out_grow----------------------------------------
669 // Grow the input array, making space for more edges
670 void Node::out_grow( uint len ) {
671 assert(!is_top(), "cannot grow a top node's out array");
672 Arena* arena = Compile::current()->node_arena();
673 uint new_max = _outmax;
674 if( new_max == 0 ) {
675 _outmax = 4;
676 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
677 return;
678 }
679 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
680 // Trimming to limit allows a uint8 to handle up to 255 edges.
681 // Previously I was using only powers-of-2 which peaked at 128 edges.
682 //if( new_max >= limit ) new_max = limit-1;
683 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
684 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
685 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
686 _outmax = new_max; // Record new max length
687 // This assertion makes sure that Node::_max is wide enough to
688 // represent the numerical value of new_max.
689 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
690 }
691
692 #ifdef ASSERT
693 //------------------------------is_dead----------------------------------------
694 bool Node::is_dead() const {
695 // Mach and pinch point nodes may look like dead.
696 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
697 return false;
698 for( uint i = 0; i < _max; i++ )
699 if( _in[i] != NULL )
700 return false;
701 dump();
702 return true;
703 }
704 #endif
705
706
707 //------------------------------is_unreachable---------------------------------
708 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
709 assert(!is_Mach(), "doesn't work with MachNodes");
710 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != NULL && in(0)->is_top());
711 }
712
713 //------------------------------add_req----------------------------------------
714 // Add a new required input at the end
715 void Node::add_req( Node *n ) {
716 assert( is_not_dead(n), "can not use dead node");
717
718 // Look to see if I can move precedence down one without reallocating
719 if( (_cnt >= _max) || (in(_max-1) != NULL) )
720 grow( _max+1 );
721
722 // Find a precedence edge to move
723 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
724 uint i;
725 for( i=_cnt; i<_max; i++ )
726 if( in(i) == NULL ) // Find the NULL at end of prec edge list
727 break; // There must be one, since we grew the array
728 _in[i] = in(_cnt); // Move prec over, making space for req edge
729 }
730 _in[_cnt++] = n; // Stuff over old prec edge
731 if (n != NULL) n->add_out((Node *)this);
732 }
733
734 //---------------------------add_req_batch-------------------------------------
735 // Add a new required input at the end
736 void Node::add_req_batch( Node *n, uint m ) {
737 assert( is_not_dead(n), "can not use dead node");
738 // check various edge cases
739 if ((int)m <= 1) {
740 assert((int)m >= 0, "oob");
741 if (m != 0) add_req(n);
742 return;
743 }
744
745 // Look to see if I can move precedence down one without reallocating
746 if( (_cnt+m) > _max || _in[_max-m] )
747 grow( _max+m );
748
749 // Find a precedence edge to move
750 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
751 uint i;
752 for( i=_cnt; i<_max; i++ )
753 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
754 break; // There must be one, since we grew the array
755 // Slide all the precs over by m positions (assume #prec << m).
756 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
757 }
758
759 // Stuff over the old prec edges
760 for(uint i=0; i<m; i++ ) {
761 _in[_cnt++] = n;
762 }
763
764 // Insert multiple out edges on the node.
765 if (n != NULL && !n->is_top()) {
766 for(uint i=0; i<m; i++ ) {
767 n->add_out((Node *)this);
768 }
769 }
770 }
771
772 //------------------------------del_req----------------------------------------
773 // Delete the required edge and compact the edge array
774 void Node::del_req( uint idx ) {
775 assert( idx < _cnt, "oob");
776 assert( !VerifyHashTableKeys || _hash_lock == 0,
777 "remove node from hash table before modifying it");
778 // First remove corresponding def-use edge
779 Node *n = in(idx);
780 if (n != NULL) n->del_out((Node *)this);
781 _in[idx] = in(--_cnt); // Compact the array
782 // Avoid spec violation: Gap in prec edges.
783 close_prec_gap_at(_cnt);
784 Compile::current()->record_modified_node(this);
785 }
786
787 //------------------------------del_req_ordered--------------------------------
788 // Delete the required edge and compact the edge array with preserved order
789 void Node::del_req_ordered( uint idx ) {
790 assert( idx < _cnt, "oob");
791 assert( !VerifyHashTableKeys || _hash_lock == 0,
792 "remove node from hash table before modifying it");
793 // First remove corresponding def-use edge
794 Node *n = in(idx);
795 if (n != NULL) n->del_out((Node *)this);
796 if (idx < --_cnt) { // Not last edge ?
797 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
798 }
799 // Avoid spec violation: Gap in prec edges.
800 close_prec_gap_at(_cnt);
801 Compile::current()->record_modified_node(this);
802 }
803
804 //------------------------------ins_req----------------------------------------
805 // Insert a new required input at the end
806 void Node::ins_req( uint idx, Node *n ) {
807 assert( is_not_dead(n), "can not use dead node");
808 add_req(NULL); // Make space
809 assert( idx < _max, "Must have allocated enough space");
810 // Slide over
811 if(_cnt-idx-1 > 0) {
812 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
813 }
814 _in[idx] = n; // Stuff over old required edge
815 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
816 }
817
818 //-----------------------------find_edge---------------------------------------
819 int Node::find_edge(Node* n) {
820 for (uint i = 0; i < len(); i++) {
821 if (_in[i] == n) return i;
822 }
823 return -1;
824 }
825
826 //----------------------------replace_edge-------------------------------------
827 int Node::replace_edge(Node* old, Node* neww) {
828 if (old == neww) return 0; // nothing to do
829 uint nrep = 0;
830 for (uint i = 0; i < len(); i++) {
831 if (in(i) == old) {
832 if (i < req()) {
833 set_req(i, neww);
834 } else {
835 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
836 set_prec(i, neww);
837 }
838 nrep++;
839 }
840 }
841 return nrep;
842 }
843
844 /**
845 * Replace input edges in the range pointing to 'old' node.
846 */
847 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
848 if (old == neww) return 0; // nothing to do
849 uint nrep = 0;
850 for (int i = start; i < end; i++) {
851 if (in(i) == old) {
852 set_req(i, neww);
853 nrep++;
854 }
855 }
856 return nrep;
857 }
858
859 //-------------------------disconnect_inputs-----------------------------------
860 // NULL out all inputs to eliminate incoming Def-Use edges.
861 // Return the number of edges between 'n' and 'this'
862 int Node::disconnect_inputs(Node *n, Compile* C) {
863 int edges_to_n = 0;
864
865 uint cnt = req();
866 for( uint i = 0; i < cnt; ++i ) {
867 if( in(i) == 0 ) continue;
868 if( in(i) == n ) ++edges_to_n;
869 set_req(i, NULL);
870 }
871 // Remove precedence edges if any exist
872 // Note: Safepoints may have precedence edges, even during parsing
873 if( (req() != len()) && (in(req()) != NULL) ) {
874 uint max = len();
875 for( uint i = 0; i < max; ++i ) {
876 if( in(i) == 0 ) continue;
877 if( in(i) == n ) ++edges_to_n;
878 set_prec(i, NULL);
879 }
880 }
881
882 // Node::destruct requires all out edges be deleted first
883 // debug_only(destruct();) // no reuse benefit expected
884 if (edges_to_n == 0) {
885 C->record_dead_node(_idx);
886 }
887 return edges_to_n;
888 }
889
890 //-----------------------------uncast---------------------------------------
891 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
892 // Strip away casting. (It is depth-limited.)
893 Node* Node::uncast() const {
894 // Should be inline:
895 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
896 if (is_ConstraintCast())
897 return uncast_helper(this);
898 else
899 return (Node*) this;
900 }
901
902 bool Node::eqv_uncast(const Node* n) const {
903 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
904 Node* obj1 = bs->step_over_gc_barrier(const_cast<Node*>(this));
905 Node* obj2 = bs->step_over_gc_barrier(const_cast<Node*>(n));
906 return (obj1->uncast() == obj2->uncast());
907 }
908
909 // Find out of current node that matches opcode.
910 Node* Node::find_out_with(int opcode) {
911 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
912 Node* use = fast_out(i);
913 if (use->Opcode() == opcode) {
914 return use;
915 }
916 }
917 return NULL;
918 }
919
920 // Return true if the current node has an out that matches opcode.
921 bool Node::has_out_with(int opcode) {
922 return (find_out_with(opcode) != NULL);
923 }
924
925 // Return true if the current node has an out that matches any of the opcodes.
926 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
927 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
928 int opcode = fast_out(i)->Opcode();
929 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
930 return true;
931 }
932 }
933 return false;
934 }
935
936
937 //---------------------------uncast_helper-------------------------------------
938 Node* Node::uncast_helper(const Node* p) {
939 #ifdef ASSERT
940 uint depth_count = 0;
941 const Node* orig_p = p;
942 #endif
943
944 while (true) {
945 #ifdef ASSERT
946 if (depth_count >= K) {
947 orig_p->dump(4);
948 if (p != orig_p)
949 p->dump(1);
950 }
951 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
952 #endif
953 if (p == NULL || p->req() != 2) {
954 break;
955 } else if (p->is_ConstraintCast()) {
956 p = p->in(1);
957 } else {
958 break;
959 }
960 }
961 return (Node*) p;
962 }
963
964 //------------------------------add_prec---------------------------------------
965 // Add a new precedence input. Precedence inputs are unordered, with
966 // duplicates removed and NULLs packed down at the end.
967 void Node::add_prec( Node *n ) {
968 assert( is_not_dead(n), "can not use dead node");
969
970 // Check for NULL at end
971 if( _cnt >= _max || in(_max-1) )
972 grow( _max+1 );
973
974 // Find a precedence edge to move
975 uint i = _cnt;
976 while( in(i) != NULL ) {
977 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
978 i++;
979 }
980 _in[i] = n; // Stuff prec edge over NULL
981 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
982
983 #ifdef ASSERT
984 while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
985 #endif
986 }
987
988 //------------------------------rm_prec----------------------------------------
989 // Remove a precedence input. Precedence inputs are unordered, with
990 // duplicates removed and NULLs packed down at the end.
991 void Node::rm_prec( uint j ) {
992 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
993 assert(j >= _cnt, "not a precedence edge");
994 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
995 _in[j]->del_out((Node *)this);
996 close_prec_gap_at(j);
997 }
998
999 //------------------------------size_of----------------------------------------
1000 uint Node::size_of() const { return sizeof(*this); }
1001
1002 //------------------------------ideal_reg--------------------------------------
1003 uint Node::ideal_reg() const { return 0; }
1004
1005 //------------------------------jvms-------------------------------------------
1006 JVMState* Node::jvms() const { return NULL; }
1007
1008 #ifdef ASSERT
1009 //------------------------------jvms-------------------------------------------
1010 bool Node::verify_jvms(const JVMState* using_jvms) const {
1011 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1012 if (jvms == using_jvms) return true;
1013 }
1014 return false;
1015 }
1016
1017 //------------------------------init_NodeProperty------------------------------
1018 void Node::init_NodeProperty() {
1019 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1020 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1021 }
1022 #endif
1023
1024 //------------------------------format-----------------------------------------
1025 // Print as assembly
1026 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1027 //------------------------------emit-------------------------------------------
1028 // Emit bytes starting at parameter 'ptr'.
1029 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1030 //------------------------------size-------------------------------------------
1031 // Size of instruction in bytes
1032 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1033
1034 //------------------------------CFG Construction-------------------------------
1035 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1036 // Goto and Return.
1037 const Node *Node::is_block_proj() const { return 0; }
1038
1039 // Minimum guaranteed type
1040 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1041
1042
1043 //------------------------------raise_bottom_type------------------------------
1044 // Get the worst-case Type output for this Node.
1045 void Node::raise_bottom_type(const Type* new_type) {
1046 if (is_Type()) {
1047 TypeNode *n = this->as_Type();
1048 if (VerifyAliases) {
1049 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1050 }
1051 n->set_type(new_type);
1052 } else if (is_Load()) {
1053 LoadNode *n = this->as_Load();
1054 if (VerifyAliases) {
1055 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1056 }
1057 n->set_type(new_type);
1058 }
1059 }
1060
1061 //------------------------------Identity---------------------------------------
1062 // Return a node that the given node is equivalent to.
1063 Node* Node::Identity(PhaseGVN* phase) {
1064 return this; // Default to no identities
1065 }
1066
1067 //------------------------------Value------------------------------------------
1068 // Compute a new Type for a node using the Type of the inputs.
1069 const Type* Node::Value(PhaseGVN* phase) const {
1070 return bottom_type(); // Default to worst-case Type
1071 }
1072
1073 //------------------------------Ideal------------------------------------------
1074 //
1075 // 'Idealize' the graph rooted at this Node.
1076 //
1077 // In order to be efficient and flexible there are some subtle invariants
1078 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1079 // these invariants, although its too slow to have on by default. If you are
1080 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1081 //
1082 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1083 // pointer. If ANY change is made, it must return the root of the reshaped
1084 // graph - even if the root is the same Node. Example: swapping the inputs
1085 // to an AddINode gives the same answer and same root, but you still have to
1086 // return the 'this' pointer instead of NULL.
1087 //
1088 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1089 // Identity call to return an old Node; basically if Identity can find
1090 // another Node have the Ideal call make no change and return NULL.
1091 // Example: AddINode::Ideal must check for add of zero; in this case it
1092 // returns NULL instead of doing any graph reshaping.
1093 //
1094 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1095 // sharing there may be other users of the old Nodes relying on their current
1096 // semantics. Modifying them will break the other users.
1097 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1098 // "X+3" unchanged in case it is shared.
1099 //
1100 // If you modify the 'this' pointer's inputs, you should use
1101 // 'set_req'. If you are making a new Node (either as the new root or
1102 // some new internal piece) you may use 'init_req' to set the initial
1103 // value. You can make a new Node with either 'new' or 'clone'. In
1104 // either case, def-use info is correctly maintained.
1105 //
1106 // Example: reshape "(X+3)+4" into "X+7":
1107 // set_req(1, in(1)->in(1));
1108 // set_req(2, phase->intcon(7));
1109 // return this;
1110 // Example: reshape "X*4" into "X<<2"
1111 // return new LShiftINode(in(1), phase->intcon(2));
1112 //
1113 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1114 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1115 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1116 // return new AddINode(shift, in(1));
1117 //
1118 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1119 // These forms are faster than 'phase->transform(new ConNode())' and Do
1120 // The Right Thing with def-use info.
1121 //
1122 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1123 // graph uses the 'this' Node it must be the root. If you want a Node with
1124 // the same Opcode as the 'this' pointer use 'clone'.
1125 //
1126 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1127 return NULL; // Default to being Ideal already
1128 }
1129
1130 // Some nodes have specific Ideal subgraph transformations only if they are
1131 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1132 // for the transformations to happen.
1133 bool Node::has_special_unique_user() const {
1134 assert(outcnt() == 1, "match only for unique out");
1135 Node* n = unique_out();
1136 int op = Opcode();
1137 if (this->is_Store()) {
1138 // Condition for back-to-back stores folding.
1139 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1140 } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1141 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1142 return n->Opcode() == Op_MemBarAcquire;
1143 } else if (op == Op_AddL) {
1144 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1145 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1146 } else if (op == Op_SubI || op == Op_SubL) {
1147 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1148 return n->Opcode() == op && n->in(2) == this;
1149 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1150 // See IfProjNode::Identity()
1151 return true;
1152 }
1153 return false;
1154 };
1155
1156 //--------------------------find_exact_control---------------------------------
1157 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1158 Node* Node::find_exact_control(Node* ctrl) {
1159 if (ctrl == NULL && this->is_Region())
1160 ctrl = this->as_Region()->is_copy();
1161
1162 if (ctrl != NULL && ctrl->is_CatchProj()) {
1163 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1164 ctrl = ctrl->in(0);
1165 if (ctrl != NULL && !ctrl->is_top())
1166 ctrl = ctrl->in(0);
1167 }
1168
1169 if (ctrl != NULL && ctrl->is_Proj())
1170 ctrl = ctrl->in(0);
1171
1172 return ctrl;
1173 }
1174
1175 //--------------------------dominates------------------------------------------
1176 // Helper function for MemNode::all_controls_dominate().
1177 // Check if 'this' control node dominates or equal to 'sub' control node.
1178 // We already know that if any path back to Root or Start reaches 'this',
1179 // then all paths so, so this is a simple search for one example,
1180 // not an exhaustive search for a counterexample.
1181 bool Node::dominates(Node* sub, Node_List &nlist) {
1182 assert(this->is_CFG(), "expecting control");
1183 assert(sub != NULL && sub->is_CFG(), "expecting control");
1184
1185 // detect dead cycle without regions
1186 int iterations_without_region_limit = DominatorSearchLimit;
1187
1188 Node* orig_sub = sub;
1189 Node* dom = this;
1190 bool met_dom = false;
1191 nlist.clear();
1192
1193 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1194 // After seeing 'dom', continue up to Root or Start.
1195 // If we hit a region (backward split point), it may be a loop head.
1196 // Keep going through one of the region's inputs. If we reach the
1197 // same region again, go through a different input. Eventually we
1198 // will either exit through the loop head, or give up.
1199 // (If we get confused, break out and return a conservative 'false'.)
1200 while (sub != NULL) {
1201 if (sub->is_top()) break; // Conservative answer for dead code.
1202 if (sub == dom) {
1203 if (nlist.size() == 0) {
1204 // No Region nodes except loops were visited before and the EntryControl
1205 // path was taken for loops: it did not walk in a cycle.
1206 return true;
1207 } else if (met_dom) {
1208 break; // already met before: walk in a cycle
1209 } else {
1210 // Region nodes were visited. Continue walk up to Start or Root
1211 // to make sure that it did not walk in a cycle.
1212 met_dom = true; // first time meet
1213 iterations_without_region_limit = DominatorSearchLimit; // Reset
1214 }
1215 }
1216 if (sub->is_Start() || sub->is_Root()) {
1217 // Success if we met 'dom' along a path to Start or Root.
1218 // We assume there are no alternative paths that avoid 'dom'.
1219 // (This assumption is up to the caller to ensure!)
1220 return met_dom;
1221 }
1222 Node* up = sub->in(0);
1223 // Normalize simple pass-through regions and projections:
1224 up = sub->find_exact_control(up);
1225 // If sub == up, we found a self-loop. Try to push past it.
1226 if (sub == up && sub->is_Loop()) {
1227 // Take loop entry path on the way up to 'dom'.
1228 up = sub->in(1); // in(LoopNode::EntryControl);
1229 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1230 // Always take in(1) path on the way up to 'dom' for clone regions
1231 // (with only one input) or regions which merge > 2 paths
1232 // (usually used to merge fast/slow paths).
1233 up = sub->in(1);
1234 } else if (sub == up && sub->is_Region()) {
1235 // Try both paths for Regions with 2 input paths (it may be a loop head).
1236 // It could give conservative 'false' answer without information
1237 // which region's input is the entry path.
1238 iterations_without_region_limit = DominatorSearchLimit; // Reset
1239
1240 bool region_was_visited_before = false;
1241 // Was this Region node visited before?
1242 // If so, we have reached it because we accidentally took a
1243 // loop-back edge from 'sub' back into the body of the loop,
1244 // and worked our way up again to the loop header 'sub'.
1245 // So, take the first unexplored path on the way up to 'dom'.
1246 for (int j = nlist.size() - 1; j >= 0; j--) {
1247 intptr_t ni = (intptr_t)nlist.at(j);
1248 Node* visited = (Node*)(ni & ~1);
1249 bool visited_twice_already = ((ni & 1) != 0);
1250 if (visited == sub) {
1251 if (visited_twice_already) {
1252 // Visited 2 paths, but still stuck in loop body. Give up.
1253 return false;
1254 }
1255 // The Region node was visited before only once.
1256 // (We will repush with the low bit set, below.)
1257 nlist.remove(j);
1258 // We will find a new edge and re-insert.
1259 region_was_visited_before = true;
1260 break;
1261 }
1262 }
1263
1264 // Find an incoming edge which has not been seen yet; walk through it.
1265 assert(up == sub, "");
1266 uint skip = region_was_visited_before ? 1 : 0;
1267 for (uint i = 1; i < sub->req(); i++) {
1268 Node* in = sub->in(i);
1269 if (in != NULL && !in->is_top() && in != sub) {
1270 if (skip == 0) {
1271 up = in;
1272 break;
1273 }
1274 --skip; // skip this nontrivial input
1275 }
1276 }
1277
1278 // Set 0 bit to indicate that both paths were taken.
1279 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1280 }
1281
1282 if (up == sub) {
1283 break; // some kind of tight cycle
1284 }
1285 if (up == orig_sub && met_dom) {
1286 // returned back after visiting 'dom'
1287 break; // some kind of cycle
1288 }
1289 if (--iterations_without_region_limit < 0) {
1290 break; // dead cycle
1291 }
1292 sub = up;
1293 }
1294
1295 // Did not meet Root or Start node in pred. chain.
1296 // Conservative answer for dead code.
1297 return false;
1298 }
1299
1300 //------------------------------remove_dead_region-----------------------------
1301 // This control node is dead. Follow the subgraph below it making everything
1302 // using it dead as well. This will happen normally via the usual IterGVN
1303 // worklist but this call is more efficient. Do not update use-def info
1304 // inside the dead region, just at the borders.
1305 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1306 // Con's are a popular node to re-hit in the hash table again.
1307 if( dead->is_Con() ) return;
1308
1309 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1310 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1311 Node_List nstack(Thread::current()->resource_area());
1312
1313 Node *top = igvn->C->top();
1314 nstack.push(dead);
1315 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1316
1317 while (nstack.size() > 0) {
1318 dead = nstack.pop();
1319 if (dead->outcnt() > 0) {
1320 // Keep dead node on stack until all uses are processed.
1321 nstack.push(dead);
1322 // For all Users of the Dead... ;-)
1323 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1324 Node* use = dead->last_out(k);
1325 igvn->hash_delete(use); // Yank from hash table prior to mod
1326 if (use->in(0) == dead) { // Found another dead node
1327 assert (!use->is_Con(), "Control for Con node should be Root node.");
1328 use->set_req(0, top); // Cut dead edge to prevent processing
1329 nstack.push(use); // the dead node again.
1330 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1331 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1332 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1333 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1334 use->set_req(0, top); // Cut self edge
1335 nstack.push(use);
1336 } else { // Else found a not-dead user
1337 // Dead if all inputs are top or null
1338 bool dead_use = !use->is_Root(); // Keep empty graph alive
1339 for (uint j = 1; j < use->req(); j++) {
1340 Node* in = use->in(j);
1341 if (in == dead) { // Turn all dead inputs into TOP
1342 use->set_req(j, top);
1343 } else if (in != NULL && !in->is_top()) {
1344 dead_use = false;
1345 }
1346 }
1347 if (dead_use) {
1348 if (use->is_Region()) {
1349 use->set_req(0, top); // Cut self edge
1350 }
1351 nstack.push(use);
1352 } else {
1353 igvn->_worklist.push(use);
1354 }
1355 }
1356 // Refresh the iterator, since any number of kills might have happened.
1357 k = dead->last_outs(kmin);
1358 }
1359 } else { // (dead->outcnt() == 0)
1360 // Done with outputs.
1361 igvn->hash_delete(dead);
1362 igvn->_worklist.remove(dead);
1363 igvn->C->remove_modified_node(dead);
1364 igvn->set_type(dead, Type::TOP);
1365 if (dead->is_macro()) {
1366 igvn->C->remove_macro_node(dead);
1367 }
1368 if (dead->is_expensive()) {
1369 igvn->C->remove_expensive_node(dead);
1370 }
1371 CastIINode* cast = dead->isa_CastII();
1372 if (cast != NULL && cast->has_range_check()) {
1373 igvn->C->remove_range_check_cast(cast);
1374 }
1375 if (dead->Opcode() == Op_Opaque4) {
1376 igvn->C->remove_range_check_cast(dead);
1377 }
1378 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1379 bs->unregister_potential_barrier_node(dead);
1380 igvn->C->record_dead_node(dead->_idx);
1381 // Kill all inputs to the dead guy
1382 for (uint i=0; i < dead->req(); i++) {
1383 Node *n = dead->in(i); // Get input to dead guy
1384 if (n != NULL && !n->is_top()) { // Input is valid?
1385 dead->set_req(i, top); // Smash input away
1386 if (n->outcnt() == 0) { // Input also goes dead?
1387 if (!n->is_Con())
1388 nstack.push(n); // Clear it out as well
1389 } else if (n->outcnt() == 1 &&
1390 n->has_special_unique_user()) {
1391 igvn->add_users_to_worklist( n );
1392 } else if (n->outcnt() <= 2 && n->is_Store()) {
1393 // Push store's uses on worklist to enable folding optimization for
1394 // store/store and store/load to the same address.
1395 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1396 // and remove_globally_dead_node().
1397 igvn->add_users_to_worklist( n );
1398 } else {
1399 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1400 }
1401 }
1402 }
1403 } // (dead->outcnt() == 0)
1404 } // while (nstack.size() > 0) for outputs
1405 return;
1406 }
1407
1408 //------------------------------remove_dead_region-----------------------------
1409 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1410 Node *n = in(0);
1411 if( !n ) return false;
1412 // Lost control into this guy? I.e., it became unreachable?
1413 // Aggressively kill all unreachable code.
1414 if (can_reshape && n->is_top()) {
1415 kill_dead_code(this, phase->is_IterGVN());
1416 return false; // Node is dead.
1417 }
1418
1419 if( n->is_Region() && n->as_Region()->is_copy() ) {
1420 Node *m = n->nonnull_req();
1421 set_req(0, m);
1422 return true;
1423 }
1424 return false;
1425 }
1426
1427 //------------------------------hash-------------------------------------------
1428 // Hash function over Nodes.
1429 uint Node::hash() const {
1430 uint sum = 0;
1431 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1432 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1433 return (sum>>2) + _cnt + Opcode();
1434 }
1435
1436 //------------------------------cmp--------------------------------------------
1437 // Compare special parts of simple Nodes
1438 uint Node::cmp( const Node &n ) const {
1439 return 1; // Must be same
1440 }
1441
1442 //------------------------------rematerialize-----------------------------------
1443 // Should we clone rather than spill this instruction?
1444 bool Node::rematerialize() const {
1445 if ( is_Mach() )
1446 return this->as_Mach()->rematerialize();
1447 else
1448 return (_flags & Flag_rematerialize) != 0;
1449 }
1450
1451 //------------------------------needs_anti_dependence_check---------------------
1452 // Nodes which use memory without consuming it, hence need antidependences.
1453 bool Node::needs_anti_dependence_check() const {
1454 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1455 return false;
1456 else
1457 return in(1)->bottom_type()->has_memory();
1458 }
1459
1460
1461 // Get an integer constant from a ConNode (or CastIINode).
1462 // Return a default value if there is no apparent constant here.
1463 const TypeInt* Node::find_int_type() const {
1464 if (this->is_Type()) {
1465 return this->as_Type()->type()->isa_int();
1466 } else if (this->is_Con()) {
1467 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1468 return this->bottom_type()->isa_int();
1469 }
1470 return NULL;
1471 }
1472
1473 // Get a pointer constant from a ConstNode.
1474 // Returns the constant if it is a pointer ConstNode
1475 intptr_t Node::get_ptr() const {
1476 assert( Opcode() == Op_ConP, "" );
1477 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1478 }
1479
1480 // Get a narrow oop constant from a ConNNode.
1481 intptr_t Node::get_narrowcon() const {
1482 assert( Opcode() == Op_ConN, "" );
1483 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1484 }
1485
1486 // Get a long constant from a ConNode.
1487 // Return a default value if there is no apparent constant here.
1488 const TypeLong* Node::find_long_type() const {
1489 if (this->is_Type()) {
1490 return this->as_Type()->type()->isa_long();
1491 } else if (this->is_Con()) {
1492 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1493 return this->bottom_type()->isa_long();
1494 }
1495 return NULL;
1496 }
1497
1498
1499 /**
1500 * Return a ptr type for nodes which should have it.
1501 */
1502 const TypePtr* Node::get_ptr_type() const {
1503 const TypePtr* tp = this->bottom_type()->make_ptr();
1504 #ifdef ASSERT
1505 if (tp == NULL) {
1506 this->dump(1);
1507 assert((tp != NULL), "unexpected node type");
1508 }
1509 #endif
1510 return tp;
1511 }
1512
1513 // Get a double constant from a ConstNode.
1514 // Returns the constant if it is a double ConstNode
1515 jdouble Node::getd() const {
1516 assert( Opcode() == Op_ConD, "" );
1517 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1518 }
1519
1520 // Get a float constant from a ConstNode.
1521 // Returns the constant if it is a float ConstNode
1522 jfloat Node::getf() const {
1523 assert( Opcode() == Op_ConF, "" );
1524 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1525 }
1526
1527 #ifndef PRODUCT
1528
1529 //------------------------------find------------------------------------------
1530 // Find a neighbor of this Node with the given _idx
1531 // If idx is negative, find its absolute value, following both _in and _out.
1532 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1533 VectorSet* old_space, VectorSet* new_space ) {
1534 int node_idx = (idx >= 0) ? idx : -idx;
1535 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1536 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1537 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1538 if( v->test(n->_idx) ) return;
1539 if( (int)n->_idx == node_idx
1540 debug_only(|| n->debug_idx() == node_idx) ) {
1541 if (result != NULL)
1542 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1543 (uintptr_t)result, (uintptr_t)n, node_idx);
1544 result = n;
1545 }
1546 v->set(n->_idx);
1547 for( uint i=0; i<n->len(); i++ ) {
1548 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1549 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1550 }
1551 // Search along forward edges also:
1552 if (idx < 0 && !only_ctrl) {
1553 for( uint j=0; j<n->outcnt(); j++ ) {
1554 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1555 }
1556 }
1557 #ifdef ASSERT
1558 // Search along debug_orig edges last, checking for cycles
1559 Node* orig = n->debug_orig();
1560 if (orig != NULL) {
1561 do {
1562 if (NotANode(orig)) break;
1563 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1564 orig = orig->debug_orig();
1565 } while (orig != NULL && orig != n->debug_orig());
1566 }
1567 #endif //ASSERT
1568 }
1569
1570 // call this from debugger:
1571 Node* find_node(Node* n, int idx) {
1572 return n->find(idx);
1573 }
1574
1575 //------------------------------find-------------------------------------------
1576 Node* Node::find(int idx) const {
1577 ResourceArea *area = Thread::current()->resource_area();
1578 VectorSet old_space(area), new_space(area);
1579 Node* result = NULL;
1580 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1581 return result;
1582 }
1583
1584 //------------------------------find_ctrl--------------------------------------
1585 // Find an ancestor to this node in the control history with given _idx
1586 Node* Node::find_ctrl(int idx) const {
1587 ResourceArea *area = Thread::current()->resource_area();
1588 VectorSet old_space(area), new_space(area);
1589 Node* result = NULL;
1590 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1591 return result;
1592 }
1593 #endif
1594
1595
1596
1597 #ifndef PRODUCT
1598
1599 // -----------------------------Name-------------------------------------------
1600 extern const char *NodeClassNames[];
1601 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1602
1603 static bool is_disconnected(const Node* n) {
1604 for (uint i = 0; i < n->req(); i++) {
1605 if (n->in(i) != NULL) return false;
1606 }
1607 return true;
1608 }
1609
1610 #ifdef ASSERT
1611 static void dump_orig(Node* orig, outputStream *st) {
1612 Compile* C = Compile::current();
1613 if (NotANode(orig)) orig = NULL;
1614 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1615 if (orig == NULL) return;
1616 st->print(" !orig=");
1617 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1618 if (NotANode(fast)) fast = NULL;
1619 while (orig != NULL) {
1620 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1621 if (discon) st->print("[");
1622 if (!Compile::current()->node_arena()->contains(orig))
1623 st->print("o");
1624 st->print("%d", orig->_idx);
1625 if (discon) st->print("]");
1626 orig = orig->debug_orig();
1627 if (NotANode(orig)) orig = NULL;
1628 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1629 if (orig != NULL) st->print(",");
1630 if (fast != NULL) {
1631 // Step fast twice for each single step of orig:
1632 fast = fast->debug_orig();
1633 if (NotANode(fast)) fast = NULL;
1634 if (fast != NULL && fast != orig) {
1635 fast = fast->debug_orig();
1636 if (NotANode(fast)) fast = NULL;
1637 }
1638 if (fast == orig) {
1639 st->print("...");
1640 break;
1641 }
1642 }
1643 }
1644 }
1645
1646 void Node::set_debug_orig(Node* orig) {
1647 _debug_orig = orig;
1648 if (BreakAtNode == 0) return;
1649 if (NotANode(orig)) orig = NULL;
1650 int trip = 10;
1651 while (orig != NULL) {
1652 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1653 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1654 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1655 BREAKPOINT;
1656 }
1657 orig = orig->debug_orig();
1658 if (NotANode(orig)) orig = NULL;
1659 if (trip-- <= 0) break;
1660 }
1661 }
1662 #endif //ASSERT
1663
1664 //------------------------------dump------------------------------------------
1665 // Dump a Node
1666 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1667 Compile* C = Compile::current();
1668 bool is_new = C->node_arena()->contains(this);
1669 C->_in_dump_cnt++;
1670 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1671
1672 // Dump the required and precedence inputs
1673 dump_req(st);
1674 dump_prec(st);
1675 // Dump the outputs
1676 dump_out(st);
1677
1678 if (is_disconnected(this)) {
1679 #ifdef ASSERT
1680 st->print(" [%d]",debug_idx());
1681 dump_orig(debug_orig(), st);
1682 #endif
1683 st->cr();
1684 C->_in_dump_cnt--;
1685 return; // don't process dead nodes
1686 }
1687
1688 if (C->clone_map().value(_idx) != 0) {
1689 C->clone_map().dump(_idx);
1690 }
1691 // Dump node-specific info
1692 dump_spec(st);
1693 #ifdef ASSERT
1694 // Dump the non-reset _debug_idx
1695 if (Verbose && WizardMode) {
1696 st->print(" [%d]",debug_idx());
1697 }
1698 #endif
1699
1700 const Type *t = bottom_type();
1701
1702 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1703 const TypeInstPtr *toop = t->isa_instptr();
1704 const TypeKlassPtr *tkls = t->isa_klassptr();
1705 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1706 if (klass && klass->is_loaded() && klass->is_interface()) {
1707 st->print(" Interface:");
1708 } else if (toop) {
1709 st->print(" Oop:");
1710 } else if (tkls) {
1711 st->print(" Klass:");
1712 }
1713 t->dump_on(st);
1714 } else if (t == Type::MEMORY) {
1715 st->print(" Memory:");
1716 MemNode::dump_adr_type(this, adr_type(), st);
1717 } else if (Verbose || WizardMode) {
1718 st->print(" Type:");
1719 if (t) {
1720 t->dump_on(st);
1721 } else {
1722 st->print("no type");
1723 }
1724 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1725 // Dump MachSpillcopy vector type.
1726 t->dump_on(st);
1727 }
1728 if (is_new) {
1729 debug_only(dump_orig(debug_orig(), st));
1730 Node_Notes* nn = C->node_notes_at(_idx);
1731 if (nn != NULL && !nn->is_clear()) {
1732 if (nn->jvms() != NULL) {
1733 st->print(" !jvms:");
1734 nn->jvms()->dump_spec(st);
1735 }
1736 }
1737 }
1738 if (suffix) st->print("%s", suffix);
1739 C->_in_dump_cnt--;
1740 }
1741
1742 //------------------------------dump_req--------------------------------------
1743 void Node::dump_req(outputStream *st) const {
1744 // Dump the required input edges
1745 for (uint i = 0; i < req(); i++) { // For all required inputs
1746 Node* d = in(i);
1747 if (d == NULL) {
1748 st->print("_ ");
1749 } else if (NotANode(d)) {
1750 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1751 } else {
1752 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1753 }
1754 }
1755 }
1756
1757
1758 //------------------------------dump_prec-------------------------------------
1759 void Node::dump_prec(outputStream *st) const {
1760 // Dump the precedence edges
1761 int any_prec = 0;
1762 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1763 Node* p = in(i);
1764 if (p != NULL) {
1765 if (!any_prec++) st->print(" |");
1766 if (NotANode(p)) { st->print("NotANode "); continue; }
1767 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1768 }
1769 }
1770 }
1771
1772 //------------------------------dump_out--------------------------------------
1773 void Node::dump_out(outputStream *st) const {
1774 // Delimit the output edges
1775 st->print(" [[");
1776 // Dump the output edges
1777 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1778 Node* u = _out[i];
1779 if (u == NULL) {
1780 st->print("_ ");
1781 } else if (NotANode(u)) {
1782 st->print("NotANode ");
1783 } else {
1784 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1785 }
1786 }
1787 st->print("]] ");
1788 }
1789
1790 //----------------------------collect_nodes_i----------------------------------
1791 // Collects nodes from an Ideal graph, starting from a given start node and
1792 // moving in a given direction until a certain depth (distance from the start
1793 // node) is reached. Duplicates are ignored.
1794 // Arguments:
1795 // nstack: the nodes are collected into this array.
1796 // start: the node at which to start collecting.
1797 // direction: if this is a positive number, collect input nodes; if it is
1798 // a negative number, collect output nodes.
1799 // depth: collect nodes up to this distance from the start node.
1800 // include_start: whether to include the start node in the result collection.
1801 // only_ctrl: whether to regard control edges only during traversal.
1802 // only_data: whether to regard data edges only during traversal.
1803 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1804 Node* s = (Node*) start; // remove const
1805 nstack->append(s);
1806 int begin = 0;
1807 int end = 0;
1808 for(uint i = 0; i < depth; i++) {
1809 end = nstack->length();
1810 for(int j = begin; j < end; j++) {
1811 Node* tp = nstack->at(j);
1812 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1813 for(uint k = 0; k < limit; k++) {
1814 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1815
1816 if (NotANode(n)) continue;
1817 // do not recurse through top or the root (would reach unrelated stuff)
1818 if (n->is_Root() || n->is_top()) continue;
1819 if (only_ctrl && !n->is_CFG()) continue;
1820 if (only_data && n->is_CFG()) continue;
1821
1822 bool on_stack = nstack->contains(n);
1823 if (!on_stack) {
1824 nstack->append(n);
1825 }
1826 }
1827 }
1828 begin = end;
1829 }
1830 if (!include_start) {
1831 nstack->remove(s);
1832 }
1833 }
1834
1835 //------------------------------dump_nodes-------------------------------------
1836 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1837 if (NotANode(start)) return;
1838
1839 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1840 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1841
1842 int end = nstack.length();
1843 if (d > 0) {
1844 for(int j = end-1; j >= 0; j--) {
1845 nstack.at(j)->dump();
1846 }
1847 } else {
1848 for(int j = 0; j < end; j++) {
1849 nstack.at(j)->dump();
1850 }
1851 }
1852 }
1853
1854 //------------------------------dump-------------------------------------------
1855 void Node::dump(int d) const {
1856 dump_nodes(this, d, false);
1857 }
1858
1859 //------------------------------dump_ctrl--------------------------------------
1860 // Dump a Node's control history to depth
1861 void Node::dump_ctrl(int d) const {
1862 dump_nodes(this, d, true);
1863 }
1864
1865 //-----------------------------dump_compact------------------------------------
1866 void Node::dump_comp() const {
1867 this->dump_comp("\n");
1868 }
1869
1870 //-----------------------------dump_compact------------------------------------
1871 // Dump a Node in compact representation, i.e., just print its name and index.
1872 // Nodes can specify additional specifics to print in compact representation by
1873 // implementing dump_compact_spec.
1874 void Node::dump_comp(const char* suffix, outputStream *st) const {
1875 Compile* C = Compile::current();
1876 C->_in_dump_cnt++;
1877 st->print("%s(%d)", Name(), _idx);
1878 this->dump_compact_spec(st);
1879 if (suffix) {
1880 st->print("%s", suffix);
1881 }
1882 C->_in_dump_cnt--;
1883 }
1884
1885 //----------------------------dump_related-------------------------------------
1886 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1887 // hand and is determined by the implementation of the virtual method rel.
1888 void Node::dump_related() const {
1889 Compile* C = Compile::current();
1890 GrowableArray <Node *> in_rel(C->unique());
1891 GrowableArray <Node *> out_rel(C->unique());
1892 this->related(&in_rel, &out_rel, false);
1893 for (int i = in_rel.length() - 1; i >= 0; i--) {
1894 in_rel.at(i)->dump();
1895 }
1896 this->dump("\n", true);
1897 for (int i = 0; i < out_rel.length(); i++) {
1898 out_rel.at(i)->dump();
1899 }
1900 }
1901
1902 //----------------------------dump_related-------------------------------------
1903 // Dump a Node's related nodes up to a given depth (distance from the start
1904 // node).
1905 // Arguments:
1906 // d_in: depth for input nodes.
1907 // d_out: depth for output nodes (note: this also is a positive number).
1908 void Node::dump_related(uint d_in, uint d_out) const {
1909 Compile* C = Compile::current();
1910 GrowableArray <Node *> in_rel(C->unique());
1911 GrowableArray <Node *> out_rel(C->unique());
1912
1913 // call collect_nodes_i directly
1914 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1915 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1916
1917 for (int i = in_rel.length() - 1; i >= 0; i--) {
1918 in_rel.at(i)->dump();
1919 }
1920 this->dump("\n", true);
1921 for (int i = 0; i < out_rel.length(); i++) {
1922 out_rel.at(i)->dump();
1923 }
1924 }
1925
1926 //------------------------dump_related_compact---------------------------------
1927 // Dump a Node's related nodes in compact representation. The notion of
1928 // "related" depends on the Node at hand and is determined by the implementation
1929 // of the virtual method rel.
1930 void Node::dump_related_compact() const {
1931 Compile* C = Compile::current();
1932 GrowableArray <Node *> in_rel(C->unique());
1933 GrowableArray <Node *> out_rel(C->unique());
1934 this->related(&in_rel, &out_rel, true);
1935 int n_in = in_rel.length();
1936 int n_out = out_rel.length();
1937
1938 this->dump_comp(n_in == 0 ? "\n" : " ");
1939 for (int i = 0; i < n_in; i++) {
1940 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1941 }
1942 for (int i = 0; i < n_out; i++) {
1943 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1944 }
1945 }
1946
1947 //------------------------------related----------------------------------------
1948 // Collect a Node's related nodes. The default behaviour just collects the
1949 // inputs and outputs at depth 1, including both control and data flow edges,
1950 // regardless of whether the presentation is compact or not. For data nodes,
1951 // the default is to collect all data inputs (till level 1 if compact), and
1952 // outputs till level 1.
1953 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1954 if (this->is_CFG()) {
1955 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1956 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1957 } else {
1958 if (compact) {
1959 this->collect_nodes(in_rel, 1, false, true);
1960 } else {
1961 this->collect_nodes_in_all_data(in_rel, false);
1962 }
1963 this->collect_nodes(out_rel, -1, false, false);
1964 }
1965 }
1966
1967 //---------------------------collect_nodes-------------------------------------
1968 // An entry point to the low-level node collection facility, to start from a
1969 // given node in the graph. The start node is by default not included in the
1970 // result.
1971 // Arguments:
1972 // ns: collect the nodes into this data structure.
1973 // d: the depth (distance from start node) to which nodes should be
1974 // collected. A value >0 indicates input nodes, a value <0, output
1975 // nodes.
1976 // ctrl: include only control nodes.
1977 // data: include only data nodes.
1978 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
1979 if (ctrl && data) {
1980 // ignore nonsensical combination
1981 return;
1982 }
1983 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
1984 }
1985
1986 //--------------------------collect_nodes_in-----------------------------------
1987 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
1988 // The maximum depth is determined using a BFS that visits all primary (data
1989 // or control) inputs and increments the depth at each level.
1990 uint d_in = 0;
1991 GrowableArray<Node*> nodes(Compile::current()->unique());
1992 nodes.push(start);
1993 int nodes_at_current_level = 1;
1994 int n_idx = 0;
1995 while (nodes_at_current_level > 0) {
1996 // Add all primary inputs reachable from the current level to the list, and
1997 // increase the depth if there were any.
1998 int nodes_at_next_level = 0;
1999 bool nodes_added = false;
2000 while (nodes_at_current_level > 0) {
2001 nodes_at_current_level--;
2002 Node* current = nodes.at(n_idx++);
2003 for (uint i = 0; i < current->len(); i++) {
2004 Node* n = current->in(i);
2005 if (NotANode(n)) {
2006 continue;
2007 }
2008 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
2009 continue;
2010 }
2011 if (!nodes.contains(n)) {
2012 nodes.push(n);
2013 nodes_added = true;
2014 nodes_at_next_level++;
2015 }
2016 }
2017 }
2018 if (nodes_added) {
2019 d_in++;
2020 }
2021 nodes_at_current_level = nodes_at_next_level;
2022 }
2023 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
2024 if (collect_secondary) {
2025 // Now, iterate over the secondary nodes in ns and add the respective
2026 // boundary reachable from them.
2027 GrowableArray<Node*> sns(Compile::current()->unique());
2028 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2029 Node* n = *it;
2030 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2031 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2032 ns->append_if_missing(*d);
2033 }
2034 sns.clear();
2035 }
2036 }
2037 }
2038
2039 //---------------------collect_nodes_in_all_data-------------------------------
2040 // Collect the entire data input graph. Include the control boundary if
2041 // requested.
2042 // Arguments:
2043 // ns: collect the nodes into this data structure.
2044 // ctrl: if true, include the control boundary.
2045 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2046 collect_nodes_in((Node*) this, ns, true, ctrl);
2047 }
2048
2049 //--------------------------collect_nodes_in_all_ctrl--------------------------
2050 // Collect the entire control input graph. Include the data boundary if
2051 // requested.
2052 // ns: collect the nodes into this data structure.
2053 // data: if true, include the control boundary.
2054 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2055 collect_nodes_in((Node*) this, ns, false, data);
2056 }
2057
2058 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2059 // Collect the entire output graph until hitting control node boundaries, and
2060 // include those.
2061 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2062 // Perform a BFS and stop at control nodes.
2063 GrowableArray<Node*> nodes(Compile::current()->unique());
2064 nodes.push((Node*) this);
2065 while (nodes.length() > 0) {
2066 Node* current = nodes.pop();
2067 if (NotANode(current)) {
2068 continue;
2069 }
2070 ns->append_if_missing(current);
2071 if (!current->is_CFG()) {
2072 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2073 nodes.push(current->out(i));
2074 }
2075 }
2076 }
2077 ns->remove((Node*) this);
2078 }
2079
2080 // VERIFICATION CODE
2081 // For each input edge to a node (ie - for each Use-Def edge), verify that
2082 // there is a corresponding Def-Use edge.
2083 //------------------------------verify_edges-----------------------------------
2084 void Node::verify_edges(Unique_Node_List &visited) {
2085 uint i, j, idx;
2086 int cnt;
2087 Node *n;
2088
2089 // Recursive termination test
2090 if (visited.member(this)) return;
2091 visited.push(this);
2092
2093 // Walk over all input edges, checking for correspondence
2094 for( i = 0; i < len(); i++ ) {
2095 n = in(i);
2096 if (n != NULL && !n->is_top()) {
2097 // Count instances of (Node *)this
2098 cnt = 0;
2099 for (idx = 0; idx < n->_outcnt; idx++ ) {
2100 if (n->_out[idx] == (Node *)this) cnt++;
2101 }
2102 assert( cnt > 0,"Failed to find Def-Use edge." );
2103 // Check for duplicate edges
2104 // walk the input array downcounting the input edges to n
2105 for( j = 0; j < len(); j++ ) {
2106 if( in(j) == n ) cnt--;
2107 }
2108 assert( cnt == 0,"Mismatched edge count.");
2109 } else if (n == NULL) {
2110 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
2111 } else {
2112 assert(n->is_top(), "sanity");
2113 // Nothing to check.
2114 }
2115 }
2116 // Recursive walk over all input edges
2117 for( i = 0; i < len(); i++ ) {
2118 n = in(i);
2119 if( n != NULL )
2120 in(i)->verify_edges(visited);
2121 }
2122 }
2123
2124 //------------------------------verify_recur-----------------------------------
2125 static const Node *unique_top = NULL;
2126
2127 void Node::verify_recur(const Node *n, int verify_depth,
2128 VectorSet &old_space, VectorSet &new_space) {
2129 if ( verify_depth == 0 ) return;
2130 if (verify_depth > 0) --verify_depth;
2131
2132 Compile* C = Compile::current();
2133
2134 // Contained in new_space or old_space?
2135 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2136 // Check for visited in the proper space. Numberings are not unique
2137 // across spaces so we need a separate VectorSet for each space.
2138 if( v->test_set(n->_idx) ) return;
2139
2140 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2141 if (C->cached_top_node() == NULL)
2142 C->set_cached_top_node((Node*)n);
2143 assert(C->cached_top_node() == n, "TOP node must be unique");
2144 }
2145
2146 for( uint i = 0; i < n->len(); i++ ) {
2147 Node *x = n->in(i);
2148 if (!x || x->is_top()) continue;
2149
2150 // Verify my input has a def-use edge to me
2151 if (true /*VerifyDefUse*/) {
2152 // Count use-def edges from n to x
2153 int cnt = 0;
2154 for( uint j = 0; j < n->len(); j++ )
2155 if( n->in(j) == x )
2156 cnt++;
2157 // Count def-use edges from x to n
2158 uint max = x->_outcnt;
2159 for( uint k = 0; k < max; k++ )
2160 if (x->_out[k] == n)
2161 cnt--;
2162 assert( cnt == 0, "mismatched def-use edge counts" );
2163 }
2164
2165 verify_recur(x, verify_depth, old_space, new_space);
2166 }
2167
2168 }
2169
2170 //------------------------------verify-----------------------------------------
2171 // Check Def-Use info for my subgraph
2172 void Node::verify() const {
2173 Compile* C = Compile::current();
2174 Node* old_top = C->cached_top_node();
2175 ResourceMark rm;
2176 ResourceArea *area = Thread::current()->resource_area();
2177 VectorSet old_space(area), new_space(area);
2178 verify_recur(this, -1, old_space, new_space);
2179 C->set_cached_top_node(old_top);
2180 }
2181 #endif
2182
2183
2184 //------------------------------walk-------------------------------------------
2185 // Graph walk, with both pre-order and post-order functions
2186 void Node::walk(NFunc pre, NFunc post, void *env) {
2187 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2188 walk_(pre, post, env, visited);
2189 }
2190
2191 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2192 if( visited.test_set(_idx) ) return;
2193 pre(*this,env); // Call the pre-order walk function
2194 for( uint i=0; i<_max; i++ )
2195 if( in(i) ) // Input exists and is not walked?
2196 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2197 post(*this,env); // Call the post-order walk function
2198 }
2199
2200 void Node::nop(Node &, void*) {}
2201
2202 //------------------------------Registers--------------------------------------
2203 // Do we Match on this edge index or not? Generally false for Control
2204 // and true for everything else. Weird for calls & returns.
2205 uint Node::match_edge(uint idx) const {
2206 return idx; // True for other than index 0 (control)
2207 }
2208
2209 static RegMask _not_used_at_all;
2210 // Register classes are defined for specific machines
2211 const RegMask &Node::out_RegMask() const {
2212 ShouldNotCallThis();
2213 return _not_used_at_all;
2214 }
2215
2216 const RegMask &Node::in_RegMask(uint) const {
2217 ShouldNotCallThis();
2218 return _not_used_at_all;
2219 }
2220
2221 //=============================================================================
2222 //-----------------------------------------------------------------------------
2223 void Node_Array::reset( Arena *new_arena ) {
2224 _a->Afree(_nodes,_max*sizeof(Node*));
2225 _max = 0;
2226 _nodes = NULL;
2227 _a = new_arena;
2228 }
2229
2230 //------------------------------clear------------------------------------------
2231 // Clear all entries in _nodes to NULL but keep storage
2232 void Node_Array::clear() {
2233 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2234 }
2235
2236 //-----------------------------------------------------------------------------
2237 void Node_Array::grow( uint i ) {
2238 if( !_max ) {
2239 _max = 1;
2240 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2241 _nodes[0] = NULL;
2242 }
2243 uint old = _max;
2244 while( i >= _max ) _max <<= 1; // Double to fit
2245 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2246 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2247 }
2248
2249 //-----------------------------------------------------------------------------
2250 void Node_Array::insert( uint i, Node *n ) {
2251 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2252 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2253 _nodes[i] = n;
2254 }
2255
2256 //-----------------------------------------------------------------------------
2257 void Node_Array::remove( uint i ) {
2258 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2259 _nodes[_max-1] = NULL;
2260 }
2261
2262 //-----------------------------------------------------------------------------
2263 void Node_Array::sort( C_sort_func_t func) {
2264 qsort( _nodes, _max, sizeof( Node* ), func );
2265 }
2266
2267 //-----------------------------------------------------------------------------
2268 void Node_Array::dump() const {
2269 #ifndef PRODUCT
2270 for( uint i = 0; i < _max; i++ ) {
2271 Node *nn = _nodes[i];
2272 if( nn != NULL ) {
2273 tty->print("%5d--> ",i); nn->dump();
2274 }
2275 }
2276 #endif
2277 }
2278
2279 //--------------------------is_iteratively_computed------------------------------
2280 // Operation appears to be iteratively computed (such as an induction variable)
2281 // It is possible for this operation to return false for a loop-varying
2282 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2283 bool Node::is_iteratively_computed() {
2284 if (ideal_reg()) { // does operation have a result register?
2285 for (uint i = 1; i < req(); i++) {
2286 Node* n = in(i);
2287 if (n != NULL && n->is_Phi()) {
2288 for (uint j = 1; j < n->req(); j++) {
2289 if (n->in(j) == this) {
2290 return true;
2291 }
2292 }
2293 }
2294 }
2295 }
2296 return false;
2297 }
2298
2299 //--------------------------find_similar------------------------------
2300 // Return a node with opcode "opc" and same inputs as "this" if one can
2301 // be found; Otherwise return NULL;
2302 Node* Node::find_similar(int opc) {
2303 if (req() >= 2) {
2304 Node* def = in(1);
2305 if (def && def->outcnt() >= 2) {
2306 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2307 Node* use = def->fast_out(i);
2308 if (use != this &&
2309 use->Opcode() == opc &&
2310 use->req() == req()) {
2311 uint j;
2312 for (j = 0; j < use->req(); j++) {
2313 if (use->in(j) != in(j)) {
2314 break;
2315 }
2316 }
2317 if (j == use->req()) {
2318 return use;
2319 }
2320 }
2321 }
2322 }
2323 }
2324 return NULL;
2325 }
2326
2327
2328 //--------------------------unique_ctrl_out------------------------------
2329 // Return the unique control out if only one. Null if none or more than one.
2330 Node* Node::unique_ctrl_out() const {
2331 Node* found = NULL;
2332 for (uint i = 0; i < outcnt(); i++) {
2333 Node* use = raw_out(i);
2334 if (use->is_CFG() && use != this) {
2335 if (found != NULL) return NULL;
2336 found = use;
2337 }
2338 }
2339 return found;
2340 }
2341
2342 void Node::ensure_control_or_add_prec(Node* c) {
2343 if (in(0) == NULL) {
2344 set_req(0, c);
2345 } else if (in(0) != c) {
2346 add_prec(c);
2347 }
2348 }
2349
2350 //=============================================================================
2351 //------------------------------yank-------------------------------------------
2352 // Find and remove
2353 void Node_List::yank( Node *n ) {
2354 uint i;
2355 for( i = 0; i < _cnt; i++ )
2356 if( _nodes[i] == n )
2357 break;
2358
2359 if( i < _cnt )
2360 _nodes[i] = _nodes[--_cnt];
2361 }
2362
2363 //------------------------------dump-------------------------------------------
2364 void Node_List::dump() const {
2365 #ifndef PRODUCT
2366 for( uint i = 0; i < _cnt; i++ )
2367 if( _nodes[i] ) {
2368 tty->print("%5d--> ",i);
2369 _nodes[i]->dump();
2370 }
2371 #endif
2372 }
2373
2374 void Node_List::dump_simple() const {
2375 #ifndef PRODUCT
2376 for( uint i = 0; i < _cnt; i++ )
2377 if( _nodes[i] ) {
2378 tty->print(" %d", _nodes[i]->_idx);
2379 } else {
2380 tty->print(" NULL");
2381 }
2382 #endif
2383 }
2384
2385 //=============================================================================
2386 //------------------------------remove-----------------------------------------
2387 void Unique_Node_List::remove( Node *n ) {
2388 if( _in_worklist[n->_idx] ) {
2389 for( uint i = 0; i < size(); i++ )
2390 if( _nodes[i] == n ) {
2391 map(i,Node_List::pop());
2392 _in_worklist >>= n->_idx;
2393 return;
2394 }
2395 ShouldNotReachHere();
2396 }
2397 }
2398
2399 //-----------------------remove_useless_nodes----------------------------------
2400 // Remove useless nodes from worklist
2401 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2402
2403 for( uint i = 0; i < size(); ++i ) {
2404 Node *n = at(i);
2405 assert( n != NULL, "Did not expect null entries in worklist");
2406 if( ! useful.test(n->_idx) ) {
2407 _in_worklist >>= n->_idx;
2408 map(i,Node_List::pop());
2409 // Node *replacement = Node_List::pop();
2410 // if( i != size() ) { // Check if removing last entry
2411 // _nodes[i] = replacement;
2412 // }
2413 --i; // Visit popped node
2414 // If it was last entry, loop terminates since size() was also reduced
2415 }
2416 }
2417 }
2418
2419 //=============================================================================
2420 void Node_Stack::grow() {
2421 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2422 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2423 size_t max = old_max << 1; // max * 2
2424 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2425 _inode_max = _inodes + max;
2426 _inode_top = _inodes + old_top; // restore _top
2427 }
2428
2429 // Node_Stack is used to map nodes.
2430 Node* Node_Stack::find(uint idx) const {
2431 uint sz = size();
2432 for (uint i=0; i < sz; i++) {
2433 if (idx == index_at(i) )
2434 return node_at(i);
2435 }
2436 return NULL;
2437 }
2438
2439 //=============================================================================
2440 uint TypeNode::size_of() const { return sizeof(*this); }
2441 #ifndef PRODUCT
2442 void TypeNode::dump_spec(outputStream *st) const {
2443 if( !Verbose && !WizardMode ) {
2444 // standard dump does this in Verbose and WizardMode
2445 st->print(" #"); _type->dump_on(st);
2446 }
2447 }
2448
2449 void TypeNode::dump_compact_spec(outputStream *st) const {
2450 st->print("#");
2451 _type->dump_on(st);
2452 }
2453 #endif
2454 uint TypeNode::hash() const {
2455 return Node::hash() + _type->hash();
2456 }
2457 uint TypeNode::cmp( const Node &n ) const
2458 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2459 const Type *TypeNode::bottom_type() const { return _type; }
2460 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
2461
2462 //------------------------------ideal_reg--------------------------------------
2463 uint TypeNode::ideal_reg() const {
2464 return _type->ideal_reg();
2465 }