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/rootnode.hpp"
41 #include "opto/type.hpp"
42 #include "utilities/copy.hpp"
43 #include "utilities/macros.hpp"
44
45 class RegMask;
46 // #include "phase.hpp"
47 class PhaseTransform;
48 class PhaseGVN;
49
50 // Arena we are currently building Nodes in
51 const uint Node::NotAMachineReg = 0xffff0000;
52
53 #ifndef PRODUCT
54 extern int nodes_created;
55 #endif
56 #ifdef __clang__
57 #pragma clang diagnostic push
58 #pragma GCC diagnostic ignored "-Wuninitialized"
59 #endif
60
61 #ifdef ASSERT
62
63 //-------------------------- construct_node------------------------------------
64 // Set a breakpoint here to identify where a particular node index is built.
65 void Node::verify_construction() {
66 _debug_orig = NULL;
67 int old_debug_idx = Compile::debug_idx();
68 int new_debug_idx = old_debug_idx+1;
69 if (new_debug_idx > 0) {
70 // Arrange that the lowest five decimal digits of _debug_idx
71 // will repeat those of _idx. In case this is somehow pathological,
72 // we continue to assign negative numbers (!) consecutively.
73 const int mod = 100000;
74 int bump = (int)(_idx - new_debug_idx) % mod;
75 if (bump < 0) bump += mod;
76 assert(bump >= 0 && bump < mod, "");
77 new_debug_idx += bump;
78 }
79 Compile::set_debug_idx(new_debug_idx);
80 set_debug_idx( new_debug_idx );
81 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
82 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
83 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
84 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
85 BREAKPOINT;
86 }
87 #if OPTO_DU_ITERATOR_ASSERT
88 _last_del = NULL;
89 _del_tick = 0;
90 #endif
91 _hash_lock = 0;
92 }
93
94
95 // #ifdef ASSERT ...
96
97 #if OPTO_DU_ITERATOR_ASSERT
98 void DUIterator_Common::sample(const Node* node) {
99 _vdui = VerifyDUIterators;
100 _node = node;
101 _outcnt = node->_outcnt;
102 _del_tick = node->_del_tick;
103 _last = NULL;
104 }
105
106 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
107 assert(_node == node, "consistent iterator source");
108 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
109 }
110
111 void DUIterator_Common::verify_resync() {
112 // Ensure that the loop body has just deleted the last guy produced.
113 const Node* node = _node;
114 // Ensure that at least one copy of the last-seen edge was deleted.
115 // Note: It is OK to delete multiple copies of the last-seen edge.
116 // Unfortunately, we have no way to verify that all the deletions delete
117 // that same edge. On this point we must use the Honor System.
118 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
119 assert(node->_last_del == _last, "must have deleted the edge just produced");
120 // We liked this deletion, so accept the resulting outcnt and tick.
121 _outcnt = node->_outcnt;
122 _del_tick = node->_del_tick;
123 }
124
125 void DUIterator_Common::reset(const DUIterator_Common& that) {
126 if (this == &that) return; // ignore assignment to self
127 if (!_vdui) {
128 // We need to initialize everything, overwriting garbage values.
129 _last = that._last;
130 _vdui = that._vdui;
131 }
132 // Note: It is legal (though odd) for an iterator over some node x
133 // to be reassigned to iterate over another node y. Some doubly-nested
134 // progress loops depend on being able to do this.
135 const Node* node = that._node;
136 // Re-initialize everything, except _last.
137 _node = node;
138 _outcnt = node->_outcnt;
139 _del_tick = node->_del_tick;
140 }
141
142 void DUIterator::sample(const Node* node) {
143 DUIterator_Common::sample(node); // Initialize the assertion data.
144 _refresh_tick = 0; // No refreshes have happened, as yet.
145 }
146
147 void DUIterator::verify(const Node* node, bool at_end_ok) {
148 DUIterator_Common::verify(node, at_end_ok);
149 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
150 }
151
152 void DUIterator::verify_increment() {
153 if (_refresh_tick & 1) {
154 // We have refreshed the index during this loop.
155 // Fix up _idx to meet asserts.
156 if (_idx > _outcnt) _idx = _outcnt;
157 }
158 verify(_node, true);
159 }
160
161 void DUIterator::verify_resync() {
162 // Note: We do not assert on _outcnt, because insertions are OK here.
163 DUIterator_Common::verify_resync();
164 // Make sure we are still in sync, possibly with no more out-edges:
165 verify(_node, true);
166 }
167
168 void DUIterator::reset(const DUIterator& that) {
169 if (this == &that) return; // self assignment is always a no-op
170 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
171 assert(that._idx == 0, "assign only the result of Node::outs()");
172 assert(_idx == that._idx, "already assigned _idx");
173 if (!_vdui) {
174 // We need to initialize everything, overwriting garbage values.
175 sample(that._node);
176 } else {
177 DUIterator_Common::reset(that);
178 if (_refresh_tick & 1) {
179 _refresh_tick++; // Clear the "was refreshed" flag.
180 }
181 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
182 }
183 }
184
185 void DUIterator::refresh() {
186 DUIterator_Common::sample(_node); // Re-fetch assertion data.
187 _refresh_tick |= 1; // Set the "was refreshed" flag.
188 }
189
190 void DUIterator::verify_finish() {
191 // If the loop has killed the node, do not require it to re-run.
192 if (_node->_outcnt == 0) _refresh_tick &= ~1;
193 // If this assert triggers, it means that a loop used refresh_out_pos
194 // to re-synch an iteration index, but the loop did not correctly
195 // re-run itself, using a "while (progress)" construct.
196 // This iterator enforces the rule that you must keep trying the loop
197 // until it "runs clean" without any need for refreshing.
198 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
199 }
200
201
202 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
203 DUIterator_Common::verify(node, at_end_ok);
204 Node** out = node->_out;
205 uint cnt = node->_outcnt;
206 assert(cnt == _outcnt, "no insertions allowed");
207 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
208 // This last check is carefully designed to work for NO_OUT_ARRAY.
209 }
210
211 void DUIterator_Fast::verify_limit() {
212 const Node* node = _node;
213 verify(node, true);
214 assert(_outp == node->_out + node->_outcnt, "limit still correct");
215 }
216
217 void DUIterator_Fast::verify_resync() {
218 const Node* node = _node;
219 if (_outp == node->_out + _outcnt) {
220 // Note that the limit imax, not the pointer i, gets updated with the
221 // exact count of deletions. (For the pointer it's always "--i".)
222 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
223 // This is a limit pointer, with a name like "imax".
224 // Fudge the _last field so that the common assert will be happy.
225 _last = (Node*) node->_last_del;
226 DUIterator_Common::verify_resync();
227 } else {
228 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
229 // A normal internal pointer.
230 DUIterator_Common::verify_resync();
231 // Make sure we are still in sync, possibly with no more out-edges:
232 verify(node, true);
233 }
234 }
235
236 void DUIterator_Fast::verify_relimit(uint n) {
237 const Node* node = _node;
238 assert((int)n > 0, "use imax -= n only with a positive count");
239 // This must be a limit pointer, with a name like "imax".
240 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
241 // The reported number of deletions must match what the node saw.
242 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
243 // Fudge the _last field so that the common assert will be happy.
244 _last = (Node*) node->_last_del;
245 DUIterator_Common::verify_resync();
246 }
247
248 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
249 assert(_outp == that._outp, "already assigned _outp");
250 DUIterator_Common::reset(that);
251 }
252
253 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
254 // at_end_ok means the _outp is allowed to underflow by 1
255 _outp += at_end_ok;
256 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
257 _outp -= at_end_ok;
258 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
259 }
260
261 void DUIterator_Last::verify_limit() {
262 // Do not require the limit address to be resynched.
263 //verify(node, true);
264 assert(_outp == _node->_out, "limit still correct");
265 }
266
267 void DUIterator_Last::verify_step(uint num_edges) {
268 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
269 _outcnt -= num_edges;
270 _del_tick += num_edges;
271 // Make sure we are still in sync, possibly with no more out-edges:
272 const Node* node = _node;
273 verify(node, true);
274 assert(node->_last_del == _last, "must have deleted the edge just produced");
275 }
276
277 #endif //OPTO_DU_ITERATOR_ASSERT
278
279
280 #endif //ASSERT
281
282
283 // This constant used to initialize _out may be any non-null value.
284 // The value NULL is reserved for the top node only.
285 #define NO_OUT_ARRAY ((Node**)-1)
286
287 // Out-of-line code from node constructors.
288 // Executed only when extra debug info. is being passed around.
289 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
290 C->set_node_notes_at(idx, nn);
291 }
292
293 // Shared initialization code.
294 inline int Node::Init(int req) {
295 Compile* C = Compile::current();
296 int idx = C->next_unique();
297
298 // Allocate memory for the necessary number of edges.
299 if (req > 0) {
300 // Allocate space for _in array to have double alignment.
301 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
302 }
303 // If there are default notes floating around, capture them:
304 Node_Notes* nn = C->default_node_notes();
305 if (nn != NULL) init_node_notes(C, idx, nn);
306
307 // Note: At this point, C is dead,
308 // and we begin to initialize the new Node.
309
310 _cnt = _max = req;
311 _outcnt = _outmax = 0;
312 _class_id = Class_Node;
313 _flags = 0;
314 _out = NO_OUT_ARRAY;
315 return idx;
316 }
317
318 //------------------------------Node-------------------------------------------
319 // Create a Node, with a given number of required edges.
320 Node::Node(uint req)
321 : _idx(Init(req))
322 #ifdef ASSERT
323 , _parse_idx(_idx)
324 #endif
325 {
326 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
327 debug_only( verify_construction() );
328 NOT_PRODUCT(nodes_created++);
329 if (req == 0) {
330 _in = NULL;
331 } else {
332 Node** to = _in;
333 for(uint i = 0; i < req; i++) {
334 to[i] = NULL;
335 }
336 }
337 }
338
339 //------------------------------Node-------------------------------------------
340 Node::Node(Node *n0)
341 : _idx(Init(1))
342 #ifdef ASSERT
343 , _parse_idx(_idx)
344 #endif
345 {
346 debug_only( verify_construction() );
347 NOT_PRODUCT(nodes_created++);
348 assert( is_not_dead(n0), "can not use dead node");
349 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
350 }
351
352 //------------------------------Node-------------------------------------------
353 Node::Node(Node *n0, Node *n1)
354 : _idx(Init(2))
355 #ifdef ASSERT
356 , _parse_idx(_idx)
357 #endif
358 {
359 debug_only( verify_construction() );
360 NOT_PRODUCT(nodes_created++);
361 assert( is_not_dead(n0), "can not use dead node");
362 assert( is_not_dead(n1), "can not use dead node");
363 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
364 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
365 }
366
367 //------------------------------Node-------------------------------------------
368 Node::Node(Node *n0, Node *n1, Node *n2)
369 : _idx(Init(3))
370 #ifdef ASSERT
371 , _parse_idx(_idx)
372 #endif
373 {
374 debug_only( verify_construction() );
375 NOT_PRODUCT(nodes_created++);
376 assert( is_not_dead(n0), "can not use dead node");
377 assert( is_not_dead(n1), "can not use dead node");
378 assert( is_not_dead(n2), "can not use dead node");
379 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
380 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
381 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
382 }
383
384 //------------------------------Node-------------------------------------------
385 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
386 : _idx(Init(4))
387 #ifdef ASSERT
388 , _parse_idx(_idx)
389 #endif
390 {
391 debug_only( verify_construction() );
392 NOT_PRODUCT(nodes_created++);
393 assert( is_not_dead(n0), "can not use dead node");
394 assert( is_not_dead(n1), "can not use dead node");
395 assert( is_not_dead(n2), "can not use dead node");
396 assert( is_not_dead(n3), "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 }
402
403 //------------------------------Node-------------------------------------------
404 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
405 : _idx(Init(5))
406 #ifdef ASSERT
407 , _parse_idx(_idx)
408 #endif
409 {
410 debug_only( verify_construction() );
411 NOT_PRODUCT(nodes_created++);
412 assert( is_not_dead(n0), "can not use dead node");
413 assert( is_not_dead(n1), "can not use dead node");
414 assert( is_not_dead(n2), "can not use dead node");
415 assert( is_not_dead(n3), "can not use dead node");
416 assert( is_not_dead(n4), "can not use dead node");
417 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
418 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
419 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
420 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
421 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
422 }
423
424 //------------------------------Node-------------------------------------------
425 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
426 Node *n4, Node *n5)
427 : _idx(Init(6))
428 #ifdef ASSERT
429 , _parse_idx(_idx)
430 #endif
431 {
432 debug_only( verify_construction() );
433 NOT_PRODUCT(nodes_created++);
434 assert( is_not_dead(n0), "can not use dead node");
435 assert( is_not_dead(n1), "can not use dead node");
436 assert( is_not_dead(n2), "can not use dead node");
437 assert( is_not_dead(n3), "can not use dead node");
438 assert( is_not_dead(n4), "can not use dead node");
439 assert( is_not_dead(n5), "can not use dead node");
440 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
441 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
442 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
443 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
444 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
445 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
446 }
447
448 //------------------------------Node-------------------------------------------
449 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
450 Node *n4, Node *n5, Node *n6)
451 : _idx(Init(7))
452 #ifdef ASSERT
453 , _parse_idx(_idx)
454 #endif
455 {
456 debug_only( verify_construction() );
457 NOT_PRODUCT(nodes_created++);
458 assert( is_not_dead(n0), "can not use dead node");
459 assert( is_not_dead(n1), "can not use dead node");
460 assert( is_not_dead(n2), "can not use dead node");
461 assert( is_not_dead(n3), "can not use dead node");
462 assert( is_not_dead(n4), "can not use dead node");
463 assert( is_not_dead(n5), "can not use dead node");
464 assert( is_not_dead(n6), "can not use dead node");
465 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
466 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
467 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
468 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
469 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
470 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
471 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
472 }
473
474 #ifdef __clang__
475 #pragma clang diagnostic pop
476 #endif
477
478
479 //------------------------------clone------------------------------------------
480 // Clone a Node.
481 Node *Node::clone() const {
482 Compile* C = Compile::current();
483 uint s = size_of(); // Size of inherited Node
484 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
485 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
486 // Set the new input pointer array
487 n->_in = (Node**)(((char*)n)+s);
488 // Cannot share the old output pointer array, so kill it
489 n->_out = NO_OUT_ARRAY;
490 // And reset the counters to 0
491 n->_outcnt = 0;
492 n->_outmax = 0;
493 // Unlock this guy, since he is not in any hash table.
494 debug_only(n->_hash_lock = 0);
495 // Walk the old node's input list to duplicate its edges
496 uint i;
497 for( i = 0; i < len(); i++ ) {
498 Node *x = in(i);
499 n->_in[i] = x;
500 if (x != NULL) x->add_out(n);
501 }
502 if (is_macro())
503 C->add_macro_node(n);
504 if (is_expensive())
505 C->add_expensive_node(n);
506 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
507 bs->register_potential_barrier_node(n);
508 // If the cloned node is a range check dependent CastII, add it to the list.
509 CastIINode* cast = n->isa_CastII();
510 if (cast != NULL && cast->has_range_check()) {
511 C->add_range_check_cast(cast);
512 }
513 if (n->Opcode() == Op_Opaque4) {
514 C->add_opaque4_node(n);
515 }
516
517 n->set_idx(C->next_unique()); // Get new unique index as well
518 debug_only( n->verify_construction() );
519 NOT_PRODUCT(nodes_created++);
520 // Do not patch over the debug_idx of a clone, because it makes it
521 // impossible to break on the clone's moment of creation.
522 //debug_only( n->set_debug_idx( debug_idx() ) );
523
524 C->copy_node_notes_to(n, (Node*) this);
525
526 // MachNode clone
527 uint nopnds;
528 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
529 MachNode *mach = n->as_Mach();
530 MachNode *mthis = this->as_Mach();
531 // Get address of _opnd_array.
532 // It should be the same offset since it is the clone of this node.
533 MachOper **from = mthis->_opnds;
534 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
535 pointer_delta((const void*)from,
536 (const void*)(&mthis->_opnds), 1));
537 mach->_opnds = to;
538 for ( uint i = 0; i < nopnds; ++i ) {
539 to[i] = from[i]->clone();
540 }
541 }
542 // cloning CallNode may need to clone JVMState
543 if (n->is_Call()) {
544 n->as_Call()->clone_jvms(C);
545 }
546 if (n->is_SafePoint()) {
547 n->as_SafePoint()->clone_replaced_nodes();
548 }
549 return n; // Return the clone
550 }
551
552 //---------------------------setup_is_top--------------------------------------
553 // Call this when changing the top node, to reassert the invariants
554 // required by Node::is_top. See Compile::set_cached_top_node.
555 void Node::setup_is_top() {
556 if (this == (Node*)Compile::current()->top()) {
557 // This node has just become top. Kill its out array.
558 _outcnt = _outmax = 0;
559 _out = NULL; // marker value for top
560 assert(is_top(), "must be top");
561 } else {
562 if (_out == NULL) _out = NO_OUT_ARRAY;
563 assert(!is_top(), "must not be top");
564 }
565 }
566
567
568 //------------------------------~Node------------------------------------------
569 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
570 void Node::destruct() {
571 // Eagerly reclaim unique Node numberings
572 Compile* compile = Compile::current();
573 if ((uint)_idx+1 == compile->unique()) {
574 compile->set_unique(compile->unique()-1);
575 }
576 // Clear debug info:
577 Node_Notes* nn = compile->node_notes_at(_idx);
578 if (nn != NULL) nn->clear();
579 // Walk the input array, freeing the corresponding output edges
580 _cnt = _max; // forget req/prec distinction
581 uint i;
582 for( i = 0; i < _max; i++ ) {
583 set_req(i, NULL);
584 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
585 }
586 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
587 // See if the input array was allocated just prior to the object
588 int edge_size = _max*sizeof(void*);
589 int out_edge_size = _outmax*sizeof(void*);
590 char *edge_end = ((char*)_in) + edge_size;
591 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
592 int node_size = size_of();
593
594 // Free the output edge array
595 if (out_edge_size > 0) {
596 compile->node_arena()->Afree(out_array, out_edge_size);
597 }
598
599 // Free the input edge array and the node itself
600 if( edge_end == (char*)this ) {
601 // It was; free the input array and object all in one hit
602 #ifndef ASSERT
603 compile->node_arena()->Afree(_in,edge_size+node_size);
604 #endif
605 } else {
606 // Free just the input array
607 compile->node_arena()->Afree(_in,edge_size);
608
609 // Free just the object
610 #ifndef ASSERT
611 compile->node_arena()->Afree(this,node_size);
612 #endif
613 }
614 if (is_macro()) {
615 compile->remove_macro_node(this);
616 }
617 if (is_expensive()) {
618 compile->remove_expensive_node(this);
619 }
620 CastIINode* cast = isa_CastII();
621 if (cast != NULL && cast->has_range_check()) {
622 compile->remove_range_check_cast(cast);
623 }
624 if (Opcode() == Op_Opaque4) {
625 compile->remove_opaque4_node(this);
626 }
627
628 if (is_SafePoint()) {
629 as_SafePoint()->delete_replaced_nodes();
630 }
631 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
632 bs->unregister_potential_barrier_node(this);
633 #ifdef ASSERT
634 // We will not actually delete the storage, but we'll make the node unusable.
635 *(address*)this = badAddress; // smash the C++ vtbl, probably
636 _in = _out = (Node**) badAddress;
637 _max = _cnt = _outmax = _outcnt = 0;
638 compile->remove_modified_node(this);
639 #endif
640 }
641
642 //------------------------------grow-------------------------------------------
643 // Grow the input array, making space for more edges
644 void Node::grow( uint len ) {
645 Arena* arena = Compile::current()->node_arena();
646 uint new_max = _max;
647 if( new_max == 0 ) {
648 _max = 4;
649 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
650 Node** to = _in;
651 to[0] = NULL;
652 to[1] = NULL;
653 to[2] = NULL;
654 to[3] = NULL;
655 return;
656 }
657 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
658 // Trimming to limit allows a uint8 to handle up to 255 edges.
659 // Previously I was using only powers-of-2 which peaked at 128 edges.
660 //if( new_max >= limit ) new_max = limit-1;
661 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
662 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
663 _max = new_max; // Record new max length
664 // This assertion makes sure that Node::_max is wide enough to
665 // represent the numerical value of new_max.
666 assert(_max == new_max && _max > len, "int width of _max is too small");
667 }
668
669 //-----------------------------out_grow----------------------------------------
670 // Grow the input array, making space for more edges
671 void Node::out_grow( uint len ) {
672 assert(!is_top(), "cannot grow a top node's out array");
673 Arena* arena = Compile::current()->node_arena();
674 uint new_max = _outmax;
675 if( new_max == 0 ) {
676 _outmax = 4;
677 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
678 return;
679 }
680 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
681 // Trimming to limit allows a uint8 to handle up to 255 edges.
682 // Previously I was using only powers-of-2 which peaked at 128 edges.
683 //if( new_max >= limit ) new_max = limit-1;
684 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
685 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
686 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
687 _outmax = new_max; // Record new max length
688 // This assertion makes sure that Node::_max is wide enough to
689 // represent the numerical value of new_max.
690 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
691 }
692
693 #ifdef ASSERT
694 //------------------------------is_dead----------------------------------------
695 bool Node::is_dead() const {
696 // Mach and pinch point nodes may look like dead.
697 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
698 return false;
699 for( uint i = 0; i < _max; i++ )
700 if( _in[i] != NULL )
701 return false;
702 dump();
703 return true;
704 }
705 #endif
706
707
708 //------------------------------is_unreachable---------------------------------
709 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
710 assert(!is_Mach(), "doesn't work with MachNodes");
711 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != NULL && in(0)->is_top());
712 }
713
714 //------------------------------add_req----------------------------------------
715 // Add a new required input at the end
716 void Node::add_req( Node *n ) {
717 assert( is_not_dead(n), "can not use dead node");
718
719 // Look to see if I can move precedence down one without reallocating
720 if( (_cnt >= _max) || (in(_max-1) != NULL) )
721 grow( _max+1 );
722
723 // Find a precedence edge to move
724 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
725 uint i;
726 for( i=_cnt; i<_max; i++ )
727 if( in(i) == NULL ) // Find the NULL at end of prec edge list
728 break; // There must be one, since we grew the array
729 _in[i] = in(_cnt); // Move prec over, making space for req edge
730 }
731 _in[_cnt++] = n; // Stuff over old prec edge
732 if (n != NULL) n->add_out((Node *)this);
733 }
734
735 //---------------------------add_req_batch-------------------------------------
736 // Add a new required input at the end
737 void Node::add_req_batch( Node *n, uint m ) {
738 assert( is_not_dead(n), "can not use dead node");
739 // check various edge cases
740 if ((int)m <= 1) {
741 assert((int)m >= 0, "oob");
742 if (m != 0) add_req(n);
743 return;
744 }
745
746 // Look to see if I can move precedence down one without reallocating
747 if( (_cnt+m) > _max || _in[_max-m] )
748 grow( _max+m );
749
750 // Find a precedence edge to move
751 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
752 uint i;
753 for( i=_cnt; i<_max; i++ )
754 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
755 break; // There must be one, since we grew the array
756 // Slide all the precs over by m positions (assume #prec << m).
757 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
758 }
759
760 // Stuff over the old prec edges
761 for(uint i=0; i<m; i++ ) {
762 _in[_cnt++] = n;
763 }
764
765 // Insert multiple out edges on the node.
766 if (n != NULL && !n->is_top()) {
767 for(uint i=0; i<m; i++ ) {
768 n->add_out((Node *)this);
769 }
770 }
771 }
772
773 //------------------------------del_req----------------------------------------
774 // Delete the required edge and compact the edge array
775 void Node::del_req( uint idx ) {
776 assert( idx < _cnt, "oob");
777 assert( !VerifyHashTableKeys || _hash_lock == 0,
778 "remove node from hash table before modifying it");
779 // First remove corresponding def-use edge
780 Node *n = in(idx);
781 if (n != NULL) n->del_out((Node *)this);
782 _in[idx] = in(--_cnt); // Compact the array
783 // Avoid spec violation: Gap in prec edges.
784 close_prec_gap_at(_cnt);
785 Compile::current()->record_modified_node(this);
786 }
787
788 //------------------------------del_req_ordered--------------------------------
789 // Delete the required edge and compact the edge array with preserved order
790 void Node::del_req_ordered( uint idx ) {
791 assert( idx < _cnt, "oob");
792 assert( !VerifyHashTableKeys || _hash_lock == 0,
793 "remove node from hash table before modifying it");
794 // First remove corresponding def-use edge
795 Node *n = in(idx);
796 if (n != NULL) n->del_out((Node *)this);
797 if (idx < --_cnt) { // Not last edge ?
798 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
799 }
800 // Avoid spec violation: Gap in prec edges.
801 close_prec_gap_at(_cnt);
802 Compile::current()->record_modified_node(this);
803 }
804
805 //------------------------------ins_req----------------------------------------
806 // Insert a new required input at the end
807 void Node::ins_req( uint idx, Node *n ) {
808 assert( is_not_dead(n), "can not use dead node");
809 add_req(NULL); // Make space
810 assert( idx < _max, "Must have allocated enough space");
811 // Slide over
812 if(_cnt-idx-1 > 0) {
813 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
814 }
815 _in[idx] = n; // Stuff over old required edge
816 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
817 }
818
819 //-----------------------------find_edge---------------------------------------
820 int Node::find_edge(Node* n) {
821 for (uint i = 0; i < len(); i++) {
822 if (_in[i] == n) return i;
823 }
824 return -1;
825 }
826
827 //----------------------------replace_edge-------------------------------------
828 int Node::replace_edge(Node* old, Node* neww) {
829 if (old == neww) return 0; // nothing to do
830 uint nrep = 0;
831 for (uint i = 0; i < len(); i++) {
832 if (in(i) == old) {
833 if (i < req()) {
834 set_req(i, neww);
835 } else {
836 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
837 set_prec(i, neww);
838 }
839 nrep++;
840 }
841 }
842 return nrep;
843 }
844
845 /**
846 * Replace input edges in the range pointing to 'old' node.
847 */
848 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
849 if (old == neww) return 0; // nothing to do
850 uint nrep = 0;
851 for (int i = start; i < end; i++) {
852 if (in(i) == old) {
853 set_req(i, neww);
854 nrep++;
855 }
856 }
857 return nrep;
858 }
859
860 //-------------------------disconnect_inputs-----------------------------------
861 // NULL out all inputs to eliminate incoming Def-Use edges.
862 // Return the number of edges between 'n' and 'this'
863 int Node::disconnect_inputs(Node *n, Compile* C) {
864 int edges_to_n = 0;
865
866 uint cnt = req();
867 for( uint i = 0; i < cnt; ++i ) {
868 if( in(i) == 0 ) continue;
869 if( in(i) == n ) ++edges_to_n;
870 set_req(i, NULL);
871 }
872 // Remove precedence edges if any exist
873 // Note: Safepoints may have precedence edges, even during parsing
874 if( (req() != len()) && (in(req()) != NULL) ) {
875 uint max = len();
876 for( uint i = 0; i < max; ++i ) {
877 if( in(i) == 0 ) continue;
878 if( in(i) == n ) ++edges_to_n;
879 set_prec(i, NULL);
880 }
881 }
882
883 // Node::destruct requires all out edges be deleted first
884 // debug_only(destruct();) // no reuse benefit expected
885 if (edges_to_n == 0) {
886 C->record_dead_node(_idx);
887 }
888 return edges_to_n;
889 }
890
891 //-----------------------------uncast---------------------------------------
892 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
893 // Strip away casting. (It is depth-limited.)
894 // Optionally, keep casts with dependencies.
895 Node* Node::uncast(bool keep_deps) const {
896 // Should be inline:
897 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
898 if (is_ConstraintCast()) {
899 return uncast_helper(this, keep_deps);
900 } else {
901 return (Node*) this;
902 }
903 }
904
905 // Find out of current node that matches opcode.
906 Node* Node::find_out_with(int opcode) {
907 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
908 Node* use = fast_out(i);
909 if (use->Opcode() == opcode) {
910 return use;
911 }
912 }
913 return NULL;
914 }
915
916 // Return true if the current node has an out that matches opcode.
917 bool Node::has_out_with(int opcode) {
918 return (find_out_with(opcode) != NULL);
919 }
920
921 // Return true if the current node has an out that matches any of the opcodes.
922 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
923 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
924 int opcode = fast_out(i)->Opcode();
925 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
926 return true;
927 }
928 }
929 return false;
930 }
931
932
933 //---------------------------uncast_helper-------------------------------------
934 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
935 #ifdef ASSERT
936 uint depth_count = 0;
937 const Node* orig_p = p;
938 #endif
939
940 while (true) {
941 #ifdef ASSERT
942 if (depth_count >= K) {
943 orig_p->dump(4);
944 if (p != orig_p)
945 p->dump(1);
946 }
947 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
948 #endif
949 if (p == NULL || p->req() != 2) {
950 break;
951 } else if (p->is_ConstraintCast()) {
952 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
953 break; // stop at casts with dependencies
954 }
955 p = p->in(1);
956 } else {
957 break;
958 }
959 }
960 return (Node*) p;
961 }
962
963 //------------------------------add_prec---------------------------------------
964 // Add a new precedence input. Precedence inputs are unordered, with
965 // duplicates removed and NULLs packed down at the end.
966 void Node::add_prec( Node *n ) {
967 assert( is_not_dead(n), "can not use dead node");
968
969 // Check for NULL at end
970 if( _cnt >= _max || in(_max-1) )
971 grow( _max+1 );
972
973 // Find a precedence edge to move
974 uint i = _cnt;
975 while( in(i) != NULL ) {
976 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
977 i++;
978 }
979 _in[i] = n; // Stuff prec edge over NULL
980 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
981
982 #ifdef ASSERT
983 while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
984 #endif
985 }
986
987 //------------------------------rm_prec----------------------------------------
988 // Remove a precedence input. Precedence inputs are unordered, with
989 // duplicates removed and NULLs packed down at the end.
990 void Node::rm_prec( uint j ) {
991 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
992 assert(j >= _cnt, "not a precedence edge");
993 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
994 _in[j]->del_out((Node *)this);
995 close_prec_gap_at(j);
996 }
997
998 //------------------------------size_of----------------------------------------
999 uint Node::size_of() const { return sizeof(*this); }
1000
1001 //------------------------------ideal_reg--------------------------------------
1002 uint Node::ideal_reg() const { return 0; }
1003
1004 //------------------------------jvms-------------------------------------------
1005 JVMState* Node::jvms() const { return NULL; }
1006
1007 #ifdef ASSERT
1008 //------------------------------jvms-------------------------------------------
1009 bool Node::verify_jvms(const JVMState* using_jvms) const {
1010 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1011 if (jvms == using_jvms) return true;
1012 }
1013 return false;
1014 }
1015
1016 //------------------------------init_NodeProperty------------------------------
1017 void Node::init_NodeProperty() {
1018 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1019 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1020 }
1021 #endif
1022
1023 //------------------------------format-----------------------------------------
1024 // Print as assembly
1025 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1026 //------------------------------emit-------------------------------------------
1027 // Emit bytes starting at parameter 'ptr'.
1028 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1029 //------------------------------size-------------------------------------------
1030 // Size of instruction in bytes
1031 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1032
1033 //------------------------------CFG Construction-------------------------------
1034 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1035 // Goto and Return.
1036 const Node *Node::is_block_proj() const { return 0; }
1037
1038 // Minimum guaranteed type
1039 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1040
1041
1042 //------------------------------raise_bottom_type------------------------------
1043 // Get the worst-case Type output for this Node.
1044 void Node::raise_bottom_type(const Type* new_type) {
1045 if (is_Type()) {
1046 TypeNode *n = this->as_Type();
1047 if (VerifyAliases) {
1048 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1049 }
1050 n->set_type(new_type);
1051 } else if (is_Load()) {
1052 LoadNode *n = this->as_Load();
1053 if (VerifyAliases) {
1054 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1055 }
1056 n->set_type(new_type);
1057 }
1058 }
1059
1060 //------------------------------Identity---------------------------------------
1061 // Return a node that the given node is equivalent to.
1062 Node* Node::Identity(PhaseGVN* phase) {
1063 return this; // Default to no identities
1064 }
1065
1066 //------------------------------Value------------------------------------------
1067 // Compute a new Type for a node using the Type of the inputs.
1068 const Type* Node::Value(PhaseGVN* phase) const {
1069 return bottom_type(); // Default to worst-case Type
1070 }
1071
1072 //------------------------------Ideal------------------------------------------
1073 //
1074 // 'Idealize' the graph rooted at this Node.
1075 //
1076 // In order to be efficient and flexible there are some subtle invariants
1077 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1078 // these invariants, although its too slow to have on by default. If you are
1079 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1080 //
1081 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1082 // pointer. If ANY change is made, it must return the root of the reshaped
1083 // graph - even if the root is the same Node. Example: swapping the inputs
1084 // to an AddINode gives the same answer and same root, but you still have to
1085 // return the 'this' pointer instead of NULL.
1086 //
1087 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1088 // Identity call to return an old Node; basically if Identity can find
1089 // another Node have the Ideal call make no change and return NULL.
1090 // Example: AddINode::Ideal must check for add of zero; in this case it
1091 // returns NULL instead of doing any graph reshaping.
1092 //
1093 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1094 // sharing there may be other users of the old Nodes relying on their current
1095 // semantics. Modifying them will break the other users.
1096 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1097 // "X+3" unchanged in case it is shared.
1098 //
1099 // If you modify the 'this' pointer's inputs, you should use
1100 // 'set_req'. If you are making a new Node (either as the new root or
1101 // some new internal piece) you may use 'init_req' to set the initial
1102 // value. You can make a new Node with either 'new' or 'clone'. In
1103 // either case, def-use info is correctly maintained.
1104 //
1105 // Example: reshape "(X+3)+4" into "X+7":
1106 // set_req(1, in(1)->in(1));
1107 // set_req(2, phase->intcon(7));
1108 // return this;
1109 // Example: reshape "X*4" into "X<<2"
1110 // return new LShiftINode(in(1), phase->intcon(2));
1111 //
1112 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1113 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1114 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1115 // return new AddINode(shift, in(1));
1116 //
1117 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1118 // These forms are faster than 'phase->transform(new ConNode())' and Do
1119 // The Right Thing with def-use info.
1120 //
1121 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1122 // graph uses the 'this' Node it must be the root. If you want a Node with
1123 // the same Opcode as the 'this' pointer use 'clone'.
1124 //
1125 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1126 return NULL; // Default to being Ideal already
1127 }
1128
1129 // Some nodes have specific Ideal subgraph transformations only if they are
1130 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1131 // for the transformations to happen.
1132 bool Node::has_special_unique_user() const {
1133 assert(outcnt() == 1, "match only for unique out");
1134 Node* n = unique_out();
1135 int op = Opcode();
1136 if (this->is_Store()) {
1137 // Condition for back-to-back stores folding.
1138 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1139 } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1140 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1141 return n->Opcode() == Op_MemBarAcquire;
1142 } else if (op == Op_AddL) {
1143 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1144 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1145 } else if (op == Op_SubI || op == Op_SubL) {
1146 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1147 return n->Opcode() == op && n->in(2) == this;
1148 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1149 // See IfProjNode::Identity()
1150 return true;
1151 } else {
1152 return BarrierSet::barrier_set()->barrier_set_c2()->has_special_unique_user(this);
1153 }
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->Opcode() == Op_SafePoint) {
1320 dead->as_SafePoint()->disconnect_from_root(igvn);
1321 }
1322 if (dead->outcnt() > 0) {
1323 // Keep dead node on stack until all uses are processed.
1324 nstack.push(dead);
1325 // For all Users of the Dead... ;-)
1326 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1327 Node* use = dead->last_out(k);
1328 igvn->hash_delete(use); // Yank from hash table prior to mod
1329 if (use->in(0) == dead) { // Found another dead node
1330 assert (!use->is_Con(), "Control for Con node should be Root node.");
1331 use->set_req(0, top); // Cut dead edge to prevent processing
1332 nstack.push(use); // the dead node again.
1333 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1334 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1335 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1336 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1337 use->set_req(0, top); // Cut self edge
1338 nstack.push(use);
1339 } else { // Else found a not-dead user
1340 // Dead if all inputs are top or null
1341 bool dead_use = !use->is_Root(); // Keep empty graph alive
1342 for (uint j = 1; j < use->req(); j++) {
1343 Node* in = use->in(j);
1344 if (in == dead) { // Turn all dead inputs into TOP
1345 use->set_req(j, top);
1346 } else if (in != NULL && !in->is_top()) {
1347 dead_use = false;
1348 }
1349 }
1350 if (dead_use) {
1351 if (use->is_Region()) {
1352 use->set_req(0, top); // Cut self edge
1353 }
1354 nstack.push(use);
1355 } else {
1356 igvn->_worklist.push(use);
1357 }
1358 }
1359 // Refresh the iterator, since any number of kills might have happened.
1360 k = dead->last_outs(kmin);
1361 }
1362 } else { // (dead->outcnt() == 0)
1363 // Done with outputs.
1364 igvn->hash_delete(dead);
1365 igvn->_worklist.remove(dead);
1366 igvn->C->remove_modified_node(dead);
1367 igvn->set_type(dead, Type::TOP);
1368 if (dead->is_macro()) {
1369 igvn->C->remove_macro_node(dead);
1370 }
1371 if (dead->is_expensive()) {
1372 igvn->C->remove_expensive_node(dead);
1373 }
1374 CastIINode* cast = dead->isa_CastII();
1375 if (cast != NULL && cast->has_range_check()) {
1376 igvn->C->remove_range_check_cast(cast);
1377 }
1378 if (dead->Opcode() == Op_Opaque4) {
1379 igvn->C->remove_opaque4_node(dead);
1380 }
1381 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1382 bs->unregister_potential_barrier_node(dead);
1383 igvn->C->record_dead_node(dead->_idx);
1384 // Kill all inputs to the dead guy
1385 for (uint i=0; i < dead->req(); i++) {
1386 Node *n = dead->in(i); // Get input to dead guy
1387 if (n != NULL && !n->is_top()) { // Input is valid?
1388 dead->set_req(i, top); // Smash input away
1389 if (n->outcnt() == 0) { // Input also goes dead?
1390 if (!n->is_Con())
1391 nstack.push(n); // Clear it out as well
1392 } else if (n->outcnt() == 1 &&
1393 n->has_special_unique_user()) {
1394 igvn->add_users_to_worklist( n );
1395 } else if (n->outcnt() <= 2 && n->is_Store()) {
1396 // Push store's uses on worklist to enable folding optimization for
1397 // store/store and store/load to the same address.
1398 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1399 // and remove_globally_dead_node().
1400 igvn->add_users_to_worklist( n );
1401 } else {
1402 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1403 }
1404 }
1405 }
1406 } // (dead->outcnt() == 0)
1407 } // while (nstack.size() > 0) for outputs
1408 return;
1409 }
1410
1411 //------------------------------remove_dead_region-----------------------------
1412 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1413 Node *n = in(0);
1414 if( !n ) return false;
1415 // Lost control into this guy? I.e., it became unreachable?
1416 // Aggressively kill all unreachable code.
1417 if (can_reshape && n->is_top()) {
1418 kill_dead_code(this, phase->is_IterGVN());
1419 return false; // Node is dead.
1420 }
1421
1422 if( n->is_Region() && n->as_Region()->is_copy() ) {
1423 Node *m = n->nonnull_req();
1424 set_req(0, m);
1425 return true;
1426 }
1427 return false;
1428 }
1429
1430 //------------------------------hash-------------------------------------------
1431 // Hash function over Nodes.
1432 uint Node::hash() const {
1433 uint sum = 0;
1434 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1435 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1436 return (sum>>2) + _cnt + Opcode();
1437 }
1438
1439 //------------------------------cmp--------------------------------------------
1440 // Compare special parts of simple Nodes
1441 bool Node::cmp( const Node &n ) const {
1442 return true; // Must be same
1443 }
1444
1445 //------------------------------rematerialize-----------------------------------
1446 // Should we clone rather than spill this instruction?
1447 bool Node::rematerialize() const {
1448 if ( is_Mach() )
1449 return this->as_Mach()->rematerialize();
1450 else
1451 return (_flags & Flag_rematerialize) != 0;
1452 }
1453
1454 //------------------------------needs_anti_dependence_check---------------------
1455 // Nodes which use memory without consuming it, hence need antidependences.
1456 bool Node::needs_anti_dependence_check() const {
1457 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1458 return false;
1459 else
1460 return in(1)->bottom_type()->has_memory();
1461 }
1462
1463
1464 // Get an integer constant from a ConNode (or CastIINode).
1465 // Return a default value if there is no apparent constant here.
1466 const TypeInt* Node::find_int_type() const {
1467 if (this->is_Type()) {
1468 return this->as_Type()->type()->isa_int();
1469 } else if (this->is_Con()) {
1470 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1471 return this->bottom_type()->isa_int();
1472 }
1473 return NULL;
1474 }
1475
1476 // Get a pointer constant from a ConstNode.
1477 // Returns the constant if it is a pointer ConstNode
1478 intptr_t Node::get_ptr() const {
1479 assert( Opcode() == Op_ConP, "" );
1480 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1481 }
1482
1483 // Get a narrow oop constant from a ConNNode.
1484 intptr_t Node::get_narrowcon() const {
1485 assert( Opcode() == Op_ConN, "" );
1486 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1487 }
1488
1489 // Get a long constant from a ConNode.
1490 // Return a default value if there is no apparent constant here.
1491 const TypeLong* Node::find_long_type() const {
1492 if (this->is_Type()) {
1493 return this->as_Type()->type()->isa_long();
1494 } else if (this->is_Con()) {
1495 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1496 return this->bottom_type()->isa_long();
1497 }
1498 return NULL;
1499 }
1500
1501
1502 /**
1503 * Return a ptr type for nodes which should have it.
1504 */
1505 const TypePtr* Node::get_ptr_type() const {
1506 const TypePtr* tp = this->bottom_type()->make_ptr();
1507 #ifdef ASSERT
1508 if (tp == NULL) {
1509 this->dump(1);
1510 assert((tp != NULL), "unexpected node type");
1511 }
1512 #endif
1513 return tp;
1514 }
1515
1516 // Get a double constant from a ConstNode.
1517 // Returns the constant if it is a double ConstNode
1518 jdouble Node::getd() const {
1519 assert( Opcode() == Op_ConD, "" );
1520 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1521 }
1522
1523 // Get a float constant from a ConstNode.
1524 // Returns the constant if it is a float ConstNode
1525 jfloat Node::getf() const {
1526 assert( Opcode() == Op_ConF, "" );
1527 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1528 }
1529
1530 #ifndef PRODUCT
1531
1532 //------------------------------find------------------------------------------
1533 // Find a neighbor of this Node with the given _idx
1534 // If idx is negative, find its absolute value, following both _in and _out.
1535 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1536 VectorSet* old_space, VectorSet* new_space ) {
1537 int node_idx = (idx >= 0) ? idx : -idx;
1538 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1539 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1540 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1541 if( v->test(n->_idx) ) return;
1542 if( (int)n->_idx == node_idx
1543 debug_only(|| n->debug_idx() == node_idx) ) {
1544 if (result != NULL)
1545 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1546 (uintptr_t)result, (uintptr_t)n, node_idx);
1547 result = n;
1548 }
1549 v->set(n->_idx);
1550 for( uint i=0; i<n->len(); i++ ) {
1551 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1552 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1553 }
1554 // Search along forward edges also:
1555 if (idx < 0 && !only_ctrl) {
1556 for( uint j=0; j<n->outcnt(); j++ ) {
1557 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1558 }
1559 }
1560 #ifdef ASSERT
1561 // Search along debug_orig edges last, checking for cycles
1562 Node* orig = n->debug_orig();
1563 if (orig != NULL) {
1564 do {
1565 if (NotANode(orig)) break;
1566 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1567 orig = orig->debug_orig();
1568 } while (orig != NULL && orig != n->debug_orig());
1569 }
1570 #endif //ASSERT
1571 }
1572
1573 // call this from debugger:
1574 Node* find_node(Node* n, int idx) {
1575 return n->find(idx);
1576 }
1577
1578 //------------------------------find-------------------------------------------
1579 Node* Node::find(int idx) const {
1580 ResourceArea *area = Thread::current()->resource_area();
1581 VectorSet old_space(area), new_space(area);
1582 Node* result = NULL;
1583 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1584 return result;
1585 }
1586
1587 //------------------------------find_ctrl--------------------------------------
1588 // Find an ancestor to this node in the control history with given _idx
1589 Node* Node::find_ctrl(int idx) const {
1590 ResourceArea *area = Thread::current()->resource_area();
1591 VectorSet old_space(area), new_space(area);
1592 Node* result = NULL;
1593 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1594 return result;
1595 }
1596 #endif
1597
1598
1599
1600 #ifndef PRODUCT
1601
1602 // -----------------------------Name-------------------------------------------
1603 extern const char *NodeClassNames[];
1604 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1605
1606 static bool is_disconnected(const Node* n) {
1607 for (uint i = 0; i < n->req(); i++) {
1608 if (n->in(i) != NULL) return false;
1609 }
1610 return true;
1611 }
1612
1613 #ifdef ASSERT
1614 static void dump_orig(Node* orig, outputStream *st) {
1615 Compile* C = Compile::current();
1616 if (NotANode(orig)) orig = NULL;
1617 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1618 if (orig == NULL) return;
1619 st->print(" !orig=");
1620 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1621 if (NotANode(fast)) fast = NULL;
1622 while (orig != NULL) {
1623 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1624 if (discon) st->print("[");
1625 if (!Compile::current()->node_arena()->contains(orig))
1626 st->print("o");
1627 st->print("%d", orig->_idx);
1628 if (discon) st->print("]");
1629 orig = orig->debug_orig();
1630 if (NotANode(orig)) orig = NULL;
1631 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1632 if (orig != NULL) st->print(",");
1633 if (fast != NULL) {
1634 // Step fast twice for each single step of orig:
1635 fast = fast->debug_orig();
1636 if (NotANode(fast)) fast = NULL;
1637 if (fast != NULL && fast != orig) {
1638 fast = fast->debug_orig();
1639 if (NotANode(fast)) fast = NULL;
1640 }
1641 if (fast == orig) {
1642 st->print("...");
1643 break;
1644 }
1645 }
1646 }
1647 }
1648
1649 void Node::set_debug_orig(Node* orig) {
1650 _debug_orig = orig;
1651 if (BreakAtNode == 0) return;
1652 if (NotANode(orig)) orig = NULL;
1653 int trip = 10;
1654 while (orig != NULL) {
1655 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1656 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1657 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1658 BREAKPOINT;
1659 }
1660 orig = orig->debug_orig();
1661 if (NotANode(orig)) orig = NULL;
1662 if (trip-- <= 0) break;
1663 }
1664 }
1665 #endif //ASSERT
1666
1667 //------------------------------dump------------------------------------------
1668 // Dump a Node
1669 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1670 Compile* C = Compile::current();
1671 bool is_new = C->node_arena()->contains(this);
1672 C->_in_dump_cnt++;
1673 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1674
1675 // Dump the required and precedence inputs
1676 dump_req(st);
1677 dump_prec(st);
1678 // Dump the outputs
1679 dump_out(st);
1680
1681 if (is_disconnected(this)) {
1682 #ifdef ASSERT
1683 st->print(" [%d]",debug_idx());
1684 dump_orig(debug_orig(), st);
1685 #endif
1686 st->cr();
1687 C->_in_dump_cnt--;
1688 return; // don't process dead nodes
1689 }
1690
1691 if (C->clone_map().value(_idx) != 0) {
1692 C->clone_map().dump(_idx);
1693 }
1694 // Dump node-specific info
1695 dump_spec(st);
1696 #ifdef ASSERT
1697 // Dump the non-reset _debug_idx
1698 if (Verbose && WizardMode) {
1699 st->print(" [%d]",debug_idx());
1700 }
1701 #endif
1702
1703 const Type *t = bottom_type();
1704
1705 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1706 const TypeInstPtr *toop = t->isa_instptr();
1707 const TypeKlassPtr *tkls = t->isa_klassptr();
1708 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1709 if (klass && klass->is_loaded() && klass->is_interface()) {
1710 st->print(" Interface:");
1711 } else if (toop) {
1712 st->print(" Oop:");
1713 } else if (tkls) {
1714 st->print(" Klass:");
1715 }
1716 t->dump_on(st);
1717 } else if (t == Type::MEMORY) {
1718 st->print(" Memory:");
1719 MemNode::dump_adr_type(this, adr_type(), st);
1720 } else if (Verbose || WizardMode) {
1721 st->print(" Type:");
1722 if (t) {
1723 t->dump_on(st);
1724 } else {
1725 st->print("no type");
1726 }
1727 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1728 // Dump MachSpillcopy vector type.
1729 t->dump_on(st);
1730 }
1731 if (is_new) {
1732 debug_only(dump_orig(debug_orig(), st));
1733 Node_Notes* nn = C->node_notes_at(_idx);
1734 if (nn != NULL && !nn->is_clear()) {
1735 if (nn->jvms() != NULL) {
1736 st->print(" !jvms:");
1737 nn->jvms()->dump_spec(st);
1738 }
1739 }
1740 }
1741 if (suffix) st->print("%s", suffix);
1742 C->_in_dump_cnt--;
1743 }
1744
1745 //------------------------------dump_req--------------------------------------
1746 void Node::dump_req(outputStream *st) const {
1747 // Dump the required input edges
1748 for (uint i = 0; i < req(); i++) { // For all required inputs
1749 Node* d = in(i);
1750 if (d == NULL) {
1751 st->print("_ ");
1752 } else if (NotANode(d)) {
1753 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1754 } else {
1755 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1756 }
1757 }
1758 }
1759
1760
1761 //------------------------------dump_prec-------------------------------------
1762 void Node::dump_prec(outputStream *st) const {
1763 // Dump the precedence edges
1764 int any_prec = 0;
1765 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1766 Node* p = in(i);
1767 if (p != NULL) {
1768 if (!any_prec++) st->print(" |");
1769 if (NotANode(p)) { st->print("NotANode "); continue; }
1770 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1771 }
1772 }
1773 }
1774
1775 //------------------------------dump_out--------------------------------------
1776 void Node::dump_out(outputStream *st) const {
1777 // Delimit the output edges
1778 st->print(" [[");
1779 // Dump the output edges
1780 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1781 Node* u = _out[i];
1782 if (u == NULL) {
1783 st->print("_ ");
1784 } else if (NotANode(u)) {
1785 st->print("NotANode ");
1786 } else {
1787 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1788 }
1789 }
1790 st->print("]] ");
1791 }
1792
1793 //----------------------------collect_nodes_i----------------------------------
1794 // Collects nodes from an Ideal graph, starting from a given start node and
1795 // moving in a given direction until a certain depth (distance from the start
1796 // node) is reached. Duplicates are ignored.
1797 // Arguments:
1798 // nstack: the nodes are collected into this array.
1799 // start: the node at which to start collecting.
1800 // direction: if this is a positive number, collect input nodes; if it is
1801 // a negative number, collect output nodes.
1802 // depth: collect nodes up to this distance from the start node.
1803 // include_start: whether to include the start node in the result collection.
1804 // only_ctrl: whether to regard control edges only during traversal.
1805 // only_data: whether to regard data edges only during traversal.
1806 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1807 Node* s = (Node*) start; // remove const
1808 nstack->append(s);
1809 int begin = 0;
1810 int end = 0;
1811 for(uint i = 0; i < depth; i++) {
1812 end = nstack->length();
1813 for(int j = begin; j < end; j++) {
1814 Node* tp = nstack->at(j);
1815 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1816 for(uint k = 0; k < limit; k++) {
1817 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1818
1819 if (NotANode(n)) continue;
1820 // do not recurse through top or the root (would reach unrelated stuff)
1821 if (n->is_Root() || n->is_top()) continue;
1822 if (only_ctrl && !n->is_CFG()) continue;
1823 if (only_data && n->is_CFG()) continue;
1824
1825 bool on_stack = nstack->contains(n);
1826 if (!on_stack) {
1827 nstack->append(n);
1828 }
1829 }
1830 }
1831 begin = end;
1832 }
1833 if (!include_start) {
1834 nstack->remove(s);
1835 }
1836 }
1837
1838 //------------------------------dump_nodes-------------------------------------
1839 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1840 if (NotANode(start)) return;
1841
1842 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1843 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1844
1845 int end = nstack.length();
1846 if (d > 0) {
1847 for(int j = end-1; j >= 0; j--) {
1848 nstack.at(j)->dump();
1849 }
1850 } else {
1851 for(int j = 0; j < end; j++) {
1852 nstack.at(j)->dump();
1853 }
1854 }
1855 }
1856
1857 //------------------------------dump-------------------------------------------
1858 void Node::dump(int d) const {
1859 dump_nodes(this, d, false);
1860 }
1861
1862 //------------------------------dump_ctrl--------------------------------------
1863 // Dump a Node's control history to depth
1864 void Node::dump_ctrl(int d) const {
1865 dump_nodes(this, d, true);
1866 }
1867
1868 //-----------------------------dump_compact------------------------------------
1869 void Node::dump_comp() const {
1870 this->dump_comp("\n");
1871 }
1872
1873 //-----------------------------dump_compact------------------------------------
1874 // Dump a Node in compact representation, i.e., just print its name and index.
1875 // Nodes can specify additional specifics to print in compact representation by
1876 // implementing dump_compact_spec.
1877 void Node::dump_comp(const char* suffix, outputStream *st) const {
1878 Compile* C = Compile::current();
1879 C->_in_dump_cnt++;
1880 st->print("%s(%d)", Name(), _idx);
1881 this->dump_compact_spec(st);
1882 if (suffix) {
1883 st->print("%s", suffix);
1884 }
1885 C->_in_dump_cnt--;
1886 }
1887
1888 //----------------------------dump_related-------------------------------------
1889 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1890 // hand and is determined by the implementation of the virtual method rel.
1891 void Node::dump_related() const {
1892 Compile* C = Compile::current();
1893 GrowableArray <Node *> in_rel(C->unique());
1894 GrowableArray <Node *> out_rel(C->unique());
1895 this->related(&in_rel, &out_rel, false);
1896 for (int i = in_rel.length() - 1; i >= 0; i--) {
1897 in_rel.at(i)->dump();
1898 }
1899 this->dump("\n", true);
1900 for (int i = 0; i < out_rel.length(); i++) {
1901 out_rel.at(i)->dump();
1902 }
1903 }
1904
1905 //----------------------------dump_related-------------------------------------
1906 // Dump a Node's related nodes up to a given depth (distance from the start
1907 // node).
1908 // Arguments:
1909 // d_in: depth for input nodes.
1910 // d_out: depth for output nodes (note: this also is a positive number).
1911 void Node::dump_related(uint d_in, uint d_out) const {
1912 Compile* C = Compile::current();
1913 GrowableArray <Node *> in_rel(C->unique());
1914 GrowableArray <Node *> out_rel(C->unique());
1915
1916 // call collect_nodes_i directly
1917 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1918 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1919
1920 for (int i = in_rel.length() - 1; i >= 0; i--) {
1921 in_rel.at(i)->dump();
1922 }
1923 this->dump("\n", true);
1924 for (int i = 0; i < out_rel.length(); i++) {
1925 out_rel.at(i)->dump();
1926 }
1927 }
1928
1929 //------------------------dump_related_compact---------------------------------
1930 // Dump a Node's related nodes in compact representation. The notion of
1931 // "related" depends on the Node at hand and is determined by the implementation
1932 // of the virtual method rel.
1933 void Node::dump_related_compact() const {
1934 Compile* C = Compile::current();
1935 GrowableArray <Node *> in_rel(C->unique());
1936 GrowableArray <Node *> out_rel(C->unique());
1937 this->related(&in_rel, &out_rel, true);
1938 int n_in = in_rel.length();
1939 int n_out = out_rel.length();
1940
1941 this->dump_comp(n_in == 0 ? "\n" : " ");
1942 for (int i = 0; i < n_in; i++) {
1943 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1944 }
1945 for (int i = 0; i < n_out; i++) {
1946 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1947 }
1948 }
1949
1950 //------------------------------related----------------------------------------
1951 // Collect a Node's related nodes. The default behaviour just collects the
1952 // inputs and outputs at depth 1, including both control and data flow edges,
1953 // regardless of whether the presentation is compact or not. For data nodes,
1954 // the default is to collect all data inputs (till level 1 if compact), and
1955 // outputs till level 1.
1956 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1957 if (this->is_CFG()) {
1958 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1959 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1960 } else {
1961 if (compact) {
1962 this->collect_nodes(in_rel, 1, false, true);
1963 } else {
1964 this->collect_nodes_in_all_data(in_rel, false);
1965 }
1966 this->collect_nodes(out_rel, -1, false, false);
1967 }
1968 }
1969
1970 //---------------------------collect_nodes-------------------------------------
1971 // An entry point to the low-level node collection facility, to start from a
1972 // given node in the graph. The start node is by default not included in the
1973 // result.
1974 // Arguments:
1975 // ns: collect the nodes into this data structure.
1976 // d: the depth (distance from start node) to which nodes should be
1977 // collected. A value >0 indicates input nodes, a value <0, output
1978 // nodes.
1979 // ctrl: include only control nodes.
1980 // data: include only data nodes.
1981 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
1982 if (ctrl && data) {
1983 // ignore nonsensical combination
1984 return;
1985 }
1986 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
1987 }
1988
1989 //--------------------------collect_nodes_in-----------------------------------
1990 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
1991 // The maximum depth is determined using a BFS that visits all primary (data
1992 // or control) inputs and increments the depth at each level.
1993 uint d_in = 0;
1994 GrowableArray<Node*> nodes(Compile::current()->unique());
1995 nodes.push(start);
1996 int nodes_at_current_level = 1;
1997 int n_idx = 0;
1998 while (nodes_at_current_level > 0) {
1999 // Add all primary inputs reachable from the current level to the list, and
2000 // increase the depth if there were any.
2001 int nodes_at_next_level = 0;
2002 bool nodes_added = false;
2003 while (nodes_at_current_level > 0) {
2004 nodes_at_current_level--;
2005 Node* current = nodes.at(n_idx++);
2006 for (uint i = 0; i < current->len(); i++) {
2007 Node* n = current->in(i);
2008 if (NotANode(n)) {
2009 continue;
2010 }
2011 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
2012 continue;
2013 }
2014 if (!nodes.contains(n)) {
2015 nodes.push(n);
2016 nodes_added = true;
2017 nodes_at_next_level++;
2018 }
2019 }
2020 }
2021 if (nodes_added) {
2022 d_in++;
2023 }
2024 nodes_at_current_level = nodes_at_next_level;
2025 }
2026 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
2027 if (collect_secondary) {
2028 // Now, iterate over the secondary nodes in ns and add the respective
2029 // boundary reachable from them.
2030 GrowableArray<Node*> sns(Compile::current()->unique());
2031 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2032 Node* n = *it;
2033 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2034 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2035 ns->append_if_missing(*d);
2036 }
2037 sns.clear();
2038 }
2039 }
2040 }
2041
2042 //---------------------collect_nodes_in_all_data-------------------------------
2043 // Collect the entire data input graph. Include the control boundary if
2044 // requested.
2045 // Arguments:
2046 // ns: collect the nodes into this data structure.
2047 // ctrl: if true, include the control boundary.
2048 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2049 collect_nodes_in((Node*) this, ns, true, ctrl);
2050 }
2051
2052 //--------------------------collect_nodes_in_all_ctrl--------------------------
2053 // Collect the entire control input graph. Include the data boundary if
2054 // requested.
2055 // ns: collect the nodes into this data structure.
2056 // data: if true, include the control boundary.
2057 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2058 collect_nodes_in((Node*) this, ns, false, data);
2059 }
2060
2061 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2062 // Collect the entire output graph until hitting control node boundaries, and
2063 // include those.
2064 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2065 // Perform a BFS and stop at control nodes.
2066 GrowableArray<Node*> nodes(Compile::current()->unique());
2067 nodes.push((Node*) this);
2068 while (nodes.length() > 0) {
2069 Node* current = nodes.pop();
2070 if (NotANode(current)) {
2071 continue;
2072 }
2073 ns->append_if_missing(current);
2074 if (!current->is_CFG()) {
2075 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2076 nodes.push(current->out(i));
2077 }
2078 }
2079 }
2080 ns->remove((Node*) this);
2081 }
2082
2083 // VERIFICATION CODE
2084 // For each input edge to a node (ie - for each Use-Def edge), verify that
2085 // there is a corresponding Def-Use edge.
2086 //------------------------------verify_edges-----------------------------------
2087 void Node::verify_edges(Unique_Node_List &visited) {
2088 uint i, j, idx;
2089 int cnt;
2090 Node *n;
2091
2092 // Recursive termination test
2093 if (visited.member(this)) return;
2094 visited.push(this);
2095
2096 // Walk over all input edges, checking for correspondence
2097 for( i = 0; i < len(); i++ ) {
2098 n = in(i);
2099 if (n != NULL && !n->is_top()) {
2100 // Count instances of (Node *)this
2101 cnt = 0;
2102 for (idx = 0; idx < n->_outcnt; idx++ ) {
2103 if (n->_out[idx] == (Node *)this) cnt++;
2104 }
2105 assert( cnt > 0,"Failed to find Def-Use edge." );
2106 // Check for duplicate edges
2107 // walk the input array downcounting the input edges to n
2108 for( j = 0; j < len(); j++ ) {
2109 if( in(j) == n ) cnt--;
2110 }
2111 assert( cnt == 0,"Mismatched edge count.");
2112 } else if (n == NULL) {
2113 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
2114 } else {
2115 assert(n->is_top(), "sanity");
2116 // Nothing to check.
2117 }
2118 }
2119 // Recursive walk over all input edges
2120 for( i = 0; i < len(); i++ ) {
2121 n = in(i);
2122 if( n != NULL )
2123 in(i)->verify_edges(visited);
2124 }
2125 }
2126
2127 //------------------------------verify_recur-----------------------------------
2128 static const Node *unique_top = NULL;
2129
2130 void Node::verify_recur(const Node *n, int verify_depth,
2131 VectorSet &old_space, VectorSet &new_space) {
2132 if ( verify_depth == 0 ) return;
2133 if (verify_depth > 0) --verify_depth;
2134
2135 Compile* C = Compile::current();
2136
2137 // Contained in new_space or old_space?
2138 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2139 // Check for visited in the proper space. Numberings are not unique
2140 // across spaces so we need a separate VectorSet for each space.
2141 if( v->test_set(n->_idx) ) return;
2142
2143 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2144 if (C->cached_top_node() == NULL)
2145 C->set_cached_top_node((Node*)n);
2146 assert(C->cached_top_node() == n, "TOP node must be unique");
2147 }
2148
2149 for( uint i = 0; i < n->len(); i++ ) {
2150 Node *x = n->in(i);
2151 if (!x || x->is_top()) continue;
2152
2153 // Verify my input has a def-use edge to me
2154 if (true /*VerifyDefUse*/) {
2155 // Count use-def edges from n to x
2156 int cnt = 0;
2157 for( uint j = 0; j < n->len(); j++ )
2158 if( n->in(j) == x )
2159 cnt++;
2160 // Count def-use edges from x to n
2161 uint max = x->_outcnt;
2162 for( uint k = 0; k < max; k++ )
2163 if (x->_out[k] == n)
2164 cnt--;
2165 assert( cnt == 0, "mismatched def-use edge counts" );
2166 }
2167
2168 verify_recur(x, verify_depth, old_space, new_space);
2169 }
2170
2171 }
2172
2173 //------------------------------verify-----------------------------------------
2174 // Check Def-Use info for my subgraph
2175 void Node::verify() const {
2176 Compile* C = Compile::current();
2177 Node* old_top = C->cached_top_node();
2178 ResourceMark rm;
2179 ResourceArea *area = Thread::current()->resource_area();
2180 VectorSet old_space(area), new_space(area);
2181 verify_recur(this, -1, old_space, new_space);
2182 C->set_cached_top_node(old_top);
2183 }
2184 #endif
2185
2186
2187 //------------------------------walk-------------------------------------------
2188 // Graph walk, with both pre-order and post-order functions
2189 void Node::walk(NFunc pre, NFunc post, void *env) {
2190 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2191 walk_(pre, post, env, visited);
2192 }
2193
2194 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2195 if( visited.test_set(_idx) ) return;
2196 pre(*this,env); // Call the pre-order walk function
2197 for( uint i=0; i<_max; i++ )
2198 if( in(i) ) // Input exists and is not walked?
2199 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2200 post(*this,env); // Call the post-order walk function
2201 }
2202
2203 void Node::nop(Node &, void*) {}
2204
2205 //------------------------------Registers--------------------------------------
2206 // Do we Match on this edge index or not? Generally false for Control
2207 // and true for everything else. Weird for calls & returns.
2208 uint Node::match_edge(uint idx) const {
2209 return idx; // True for other than index 0 (control)
2210 }
2211
2212 static RegMask _not_used_at_all;
2213 // Register classes are defined for specific machines
2214 const RegMask &Node::out_RegMask() const {
2215 ShouldNotCallThis();
2216 return _not_used_at_all;
2217 }
2218
2219 const RegMask &Node::in_RegMask(uint) const {
2220 ShouldNotCallThis();
2221 return _not_used_at_all;
2222 }
2223
2224 //=============================================================================
2225 //-----------------------------------------------------------------------------
2226 void Node_Array::reset( Arena *new_arena ) {
2227 _a->Afree(_nodes,_max*sizeof(Node*));
2228 _max = 0;
2229 _nodes = NULL;
2230 _a = new_arena;
2231 }
2232
2233 //------------------------------clear------------------------------------------
2234 // Clear all entries in _nodes to NULL but keep storage
2235 void Node_Array::clear() {
2236 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2237 }
2238
2239 //-----------------------------------------------------------------------------
2240 void Node_Array::grow( uint i ) {
2241 if( !_max ) {
2242 _max = 1;
2243 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2244 _nodes[0] = NULL;
2245 }
2246 uint old = _max;
2247 while( i >= _max ) _max <<= 1; // Double to fit
2248 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2249 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2250 }
2251
2252 //-----------------------------------------------------------------------------
2253 void Node_Array::insert( uint i, Node *n ) {
2254 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2255 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2256 _nodes[i] = n;
2257 }
2258
2259 //-----------------------------------------------------------------------------
2260 void Node_Array::remove( uint i ) {
2261 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2262 _nodes[_max-1] = NULL;
2263 }
2264
2265 //-----------------------------------------------------------------------------
2266 void Node_Array::sort( C_sort_func_t func) {
2267 qsort( _nodes, _max, sizeof( Node* ), func );
2268 }
2269
2270 //-----------------------------------------------------------------------------
2271 void Node_Array::dump() const {
2272 #ifndef PRODUCT
2273 for( uint i = 0; i < _max; i++ ) {
2274 Node *nn = _nodes[i];
2275 if( nn != NULL ) {
2276 tty->print("%5d--> ",i); nn->dump();
2277 }
2278 }
2279 #endif
2280 }
2281
2282 //--------------------------is_iteratively_computed------------------------------
2283 // Operation appears to be iteratively computed (such as an induction variable)
2284 // It is possible for this operation to return false for a loop-varying
2285 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2286 bool Node::is_iteratively_computed() {
2287 if (ideal_reg()) { // does operation have a result register?
2288 for (uint i = 1; i < req(); i++) {
2289 Node* n = in(i);
2290 if (n != NULL && n->is_Phi()) {
2291 for (uint j = 1; j < n->req(); j++) {
2292 if (n->in(j) == this) {
2293 return true;
2294 }
2295 }
2296 }
2297 }
2298 }
2299 return false;
2300 }
2301
2302 //--------------------------find_similar------------------------------
2303 // Return a node with opcode "opc" and same inputs as "this" if one can
2304 // be found; Otherwise return NULL;
2305 Node* Node::find_similar(int opc) {
2306 if (req() >= 2) {
2307 Node* def = in(1);
2308 if (def && def->outcnt() >= 2) {
2309 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2310 Node* use = def->fast_out(i);
2311 if (use != this &&
2312 use->Opcode() == opc &&
2313 use->req() == req()) {
2314 uint j;
2315 for (j = 0; j < use->req(); j++) {
2316 if (use->in(j) != in(j)) {
2317 break;
2318 }
2319 }
2320 if (j == use->req()) {
2321 return use;
2322 }
2323 }
2324 }
2325 }
2326 }
2327 return NULL;
2328 }
2329
2330
2331 //--------------------------unique_ctrl_out------------------------------
2332 // Return the unique control out if only one. Null if none or more than one.
2333 Node* Node::unique_ctrl_out() const {
2334 Node* found = NULL;
2335 for (uint i = 0; i < outcnt(); i++) {
2336 Node* use = raw_out(i);
2337 if (use->is_CFG() && use != this) {
2338 if (found != NULL) return NULL;
2339 found = use;
2340 }
2341 }
2342 return found;
2343 }
2344
2345 void Node::ensure_control_or_add_prec(Node* c) {
2346 if (in(0) == NULL) {
2347 set_req(0, c);
2348 } else if (in(0) != c) {
2349 add_prec(c);
2350 }
2351 }
2352
2353 //=============================================================================
2354 //------------------------------yank-------------------------------------------
2355 // Find and remove
2356 void Node_List::yank( Node *n ) {
2357 uint i;
2358 for( i = 0; i < _cnt; i++ )
2359 if( _nodes[i] == n )
2360 break;
2361
2362 if( i < _cnt )
2363 _nodes[i] = _nodes[--_cnt];
2364 }
2365
2366 //------------------------------dump-------------------------------------------
2367 void Node_List::dump() const {
2368 #ifndef PRODUCT
2369 for( uint i = 0; i < _cnt; i++ )
2370 if( _nodes[i] ) {
2371 tty->print("%5d--> ",i);
2372 _nodes[i]->dump();
2373 }
2374 #endif
2375 }
2376
2377 void Node_List::dump_simple() const {
2378 #ifndef PRODUCT
2379 for( uint i = 0; i < _cnt; i++ )
2380 if( _nodes[i] ) {
2381 tty->print(" %d", _nodes[i]->_idx);
2382 } else {
2383 tty->print(" NULL");
2384 }
2385 #endif
2386 }
2387
2388 //=============================================================================
2389 //------------------------------remove-----------------------------------------
2390 void Unique_Node_List::remove( Node *n ) {
2391 if( _in_worklist[n->_idx] ) {
2392 for( uint i = 0; i < size(); i++ )
2393 if( _nodes[i] == n ) {
2394 map(i,Node_List::pop());
2395 _in_worklist >>= n->_idx;
2396 return;
2397 }
2398 ShouldNotReachHere();
2399 }
2400 }
2401
2402 //-----------------------remove_useless_nodes----------------------------------
2403 // Remove useless nodes from worklist
2404 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2405
2406 for( uint i = 0; i < size(); ++i ) {
2407 Node *n = at(i);
2408 assert( n != NULL, "Did not expect null entries in worklist");
2409 if( ! useful.test(n->_idx) ) {
2410 _in_worklist >>= n->_idx;
2411 map(i,Node_List::pop());
2412 // Node *replacement = Node_List::pop();
2413 // if( i != size() ) { // Check if removing last entry
2414 // _nodes[i] = replacement;
2415 // }
2416 --i; // Visit popped node
2417 // If it was last entry, loop terminates since size() was also reduced
2418 }
2419 }
2420 }
2421
2422 //=============================================================================
2423 void Node_Stack::grow() {
2424 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2425 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2426 size_t max = old_max << 1; // max * 2
2427 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2428 _inode_max = _inodes + max;
2429 _inode_top = _inodes + old_top; // restore _top
2430 }
2431
2432 // Node_Stack is used to map nodes.
2433 Node* Node_Stack::find(uint idx) const {
2434 uint sz = size();
2435 for (uint i=0; i < sz; i++) {
2436 if (idx == index_at(i) )
2437 return node_at(i);
2438 }
2439 return NULL;
2440 }
2441
2442 //=============================================================================
2443 uint TypeNode::size_of() const { return sizeof(*this); }
2444 #ifndef PRODUCT
2445 void TypeNode::dump_spec(outputStream *st) const {
2446 if( !Verbose && !WizardMode ) {
2447 // standard dump does this in Verbose and WizardMode
2448 st->print(" #"); _type->dump_on(st);
2449 }
2450 }
2451
2452 void TypeNode::dump_compact_spec(outputStream *st) const {
2453 st->print("#");
2454 _type->dump_on(st);
2455 }
2456 #endif
2457 uint TypeNode::hash() const {
2458 return Node::hash() + _type->hash();
2459 }
2460 bool TypeNode::cmp( const Node &n ) const
2461 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2462 const Type *TypeNode::bottom_type() const { return _type; }
2463 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
2464
2465 //------------------------------ideal_reg--------------------------------------
2466 uint TypeNode::ideal_reg() const {
2467 return _type->ideal_reg();
2468 }