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 "libadt/vectset.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "opto/castnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/connode.hpp"
32 #include "opto/loopnode.hpp"
33 #include "opto/machnode.hpp"
34 #include "opto/matcher.hpp"
35 #include "opto/node.hpp"
36 #include "opto/opcodes.hpp"
37 #include "opto/regmask.hpp"
38 #include "opto/type.hpp"
39 #include "utilities/copy.hpp"
40
41 class RegMask;
42 // #include "phase.hpp"
43 class PhaseTransform;
44 class PhaseGVN;
45
46 // Arena we are currently building Nodes in
47 const uint Node::NotAMachineReg = 0xffff0000;
48
49 #ifndef PRODUCT
50 extern int nodes_created;
51 #endif
52 #ifdef __clang__
53 #pragma clang diagnostic push
54 #pragma GCC diagnostic ignored "-Wuninitialized"
55 #endif
56
57 #ifdef ASSERT
58
59 //-------------------------- construct_node------------------------------------
60 // Set a breakpoint here to identify where a particular node index is built.
61 void Node::verify_construction() {
62 _debug_orig = NULL;
63 int old_debug_idx = Compile::debug_idx();
64 int new_debug_idx = old_debug_idx+1;
65 if (new_debug_idx > 0) {
66 // Arrange that the lowest five decimal digits of _debug_idx
67 // will repeat those of _idx. In case this is somehow pathological,
68 // we continue to assign negative numbers (!) consecutively.
69 const int mod = 100000;
70 int bump = (int)(_idx - new_debug_idx) % mod;
71 if (bump < 0) bump += mod;
72 assert(bump >= 0 && bump < mod, "");
73 new_debug_idx += bump;
74 }
75 Compile::set_debug_idx(new_debug_idx);
76 set_debug_idx( new_debug_idx );
77 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
78 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
79 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
80 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
81 BREAKPOINT;
82 }
83 #if OPTO_DU_ITERATOR_ASSERT
84 _last_del = NULL;
85 _del_tick = 0;
86 #endif
87 _hash_lock = 0;
88 }
89
90
91 // #ifdef ASSERT ...
92
93 #if OPTO_DU_ITERATOR_ASSERT
94 void DUIterator_Common::sample(const Node* node) {
95 _vdui = VerifyDUIterators;
96 _node = node;
97 _outcnt = node->_outcnt;
98 _del_tick = node->_del_tick;
99 _last = NULL;
100 }
101
102 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
103 assert(_node == node, "consistent iterator source");
104 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
105 }
106
107 void DUIterator_Common::verify_resync() {
108 // Ensure that the loop body has just deleted the last guy produced.
109 const Node* node = _node;
110 // Ensure that at least one copy of the last-seen edge was deleted.
111 // Note: It is OK to delete multiple copies of the last-seen edge.
112 // Unfortunately, we have no way to verify that all the deletions delete
113 // that same edge. On this point we must use the Honor System.
114 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
115 assert(node->_last_del == _last, "must have deleted the edge just produced");
116 // We liked this deletion, so accept the resulting outcnt and tick.
117 _outcnt = node->_outcnt;
118 _del_tick = node->_del_tick;
119 }
120
121 void DUIterator_Common::reset(const DUIterator_Common& that) {
122 if (this == &that) return; // ignore assignment to self
123 if (!_vdui) {
124 // We need to initialize everything, overwriting garbage values.
125 _last = that._last;
126 _vdui = that._vdui;
127 }
128 // Note: It is legal (though odd) for an iterator over some node x
129 // to be reassigned to iterate over another node y. Some doubly-nested
130 // progress loops depend on being able to do this.
131 const Node* node = that._node;
132 // Re-initialize everything, except _last.
133 _node = node;
134 _outcnt = node->_outcnt;
135 _del_tick = node->_del_tick;
136 }
137
138 void DUIterator::sample(const Node* node) {
139 DUIterator_Common::sample(node); // Initialize the assertion data.
140 _refresh_tick = 0; // No refreshes have happened, as yet.
141 }
142
143 void DUIterator::verify(const Node* node, bool at_end_ok) {
144 DUIterator_Common::verify(node, at_end_ok);
145 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
146 }
147
148 void DUIterator::verify_increment() {
149 if (_refresh_tick & 1) {
150 // We have refreshed the index during this loop.
151 // Fix up _idx to meet asserts.
152 if (_idx > _outcnt) _idx = _outcnt;
153 }
154 verify(_node, true);
155 }
156
157 void DUIterator::verify_resync() {
158 // Note: We do not assert on _outcnt, because insertions are OK here.
159 DUIterator_Common::verify_resync();
160 // Make sure we are still in sync, possibly with no more out-edges:
161 verify(_node, true);
162 }
163
164 void DUIterator::reset(const DUIterator& that) {
165 if (this == &that) return; // self assignment is always a no-op
166 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
167 assert(that._idx == 0, "assign only the result of Node::outs()");
168 assert(_idx == that._idx, "already assigned _idx");
169 if (!_vdui) {
170 // We need to initialize everything, overwriting garbage values.
171 sample(that._node);
172 } else {
173 DUIterator_Common::reset(that);
174 if (_refresh_tick & 1) {
175 _refresh_tick++; // Clear the "was refreshed" flag.
176 }
177 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
178 }
179 }
180
181 void DUIterator::refresh() {
182 DUIterator_Common::sample(_node); // Re-fetch assertion data.
183 _refresh_tick |= 1; // Set the "was refreshed" flag.
184 }
185
186 void DUIterator::verify_finish() {
187 // If the loop has killed the node, do not require it to re-run.
188 if (_node->_outcnt == 0) _refresh_tick &= ~1;
189 // If this assert triggers, it means that a loop used refresh_out_pos
190 // to re-synch an iteration index, but the loop did not correctly
191 // re-run itself, using a "while (progress)" construct.
192 // This iterator enforces the rule that you must keep trying the loop
193 // until it "runs clean" without any need for refreshing.
194 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
195 }
196
197
198 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
199 DUIterator_Common::verify(node, at_end_ok);
200 Node** out = node->_out;
201 uint cnt = node->_outcnt;
202 assert(cnt == _outcnt, "no insertions allowed");
203 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
204 // This last check is carefully designed to work for NO_OUT_ARRAY.
205 }
206
207 void DUIterator_Fast::verify_limit() {
208 const Node* node = _node;
209 verify(node, true);
210 assert(_outp == node->_out + node->_outcnt, "limit still correct");
211 }
212
213 void DUIterator_Fast::verify_resync() {
214 const Node* node = _node;
215 if (_outp == node->_out + _outcnt) {
216 // Note that the limit imax, not the pointer i, gets updated with the
217 // exact count of deletions. (For the pointer it's always "--i".)
218 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
219 // This is a limit pointer, with a name like "imax".
220 // Fudge the _last field so that the common assert will be happy.
221 _last = (Node*) node->_last_del;
222 DUIterator_Common::verify_resync();
223 } else {
224 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
225 // A normal internal pointer.
226 DUIterator_Common::verify_resync();
227 // Make sure we are still in sync, possibly with no more out-edges:
228 verify(node, true);
229 }
230 }
231
232 void DUIterator_Fast::verify_relimit(uint n) {
233 const Node* node = _node;
234 assert((int)n > 0, "use imax -= n only with a positive count");
235 // This must be a limit pointer, with a name like "imax".
236 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
237 // The reported number of deletions must match what the node saw.
238 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
239 // Fudge the _last field so that the common assert will be happy.
240 _last = (Node*) node->_last_del;
241 DUIterator_Common::verify_resync();
242 }
243
244 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
245 assert(_outp == that._outp, "already assigned _outp");
246 DUIterator_Common::reset(that);
247 }
248
249 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
250 // at_end_ok means the _outp is allowed to underflow by 1
251 _outp += at_end_ok;
252 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
253 _outp -= at_end_ok;
254 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
255 }
256
257 void DUIterator_Last::verify_limit() {
258 // Do not require the limit address to be resynched.
259 //verify(node, true);
260 assert(_outp == _node->_out, "limit still correct");
261 }
262
263 void DUIterator_Last::verify_step(uint num_edges) {
264 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
265 _outcnt -= num_edges;
266 _del_tick += num_edges;
267 // Make sure we are still in sync, possibly with no more out-edges:
268 const Node* node = _node;
269 verify(node, true);
270 assert(node->_last_del == _last, "must have deleted the edge just produced");
271 }
272
273 #endif //OPTO_DU_ITERATOR_ASSERT
274
275
276 #endif //ASSERT
277
278
279 // This constant used to initialize _out may be any non-null value.
280 // The value NULL is reserved for the top node only.
281 #define NO_OUT_ARRAY ((Node**)-1)
282
283 // Out-of-line code from node constructors.
284 // Executed only when extra debug info. is being passed around.
285 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
286 C->set_node_notes_at(idx, nn);
287 }
288
289 // Shared initialization code.
290 inline int Node::Init(int req) {
291 Compile* C = Compile::current();
292 int idx = C->next_unique();
293
294 // Allocate memory for the necessary number of edges.
295 if (req > 0) {
296 // Allocate space for _in array to have double alignment.
297 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
298 }
299 // If there are default notes floating around, capture them:
300 Node_Notes* nn = C->default_node_notes();
301 if (nn != NULL) init_node_notes(C, idx, nn);
302
303 // Note: At this point, C is dead,
304 // and we begin to initialize the new Node.
305
306 _cnt = _max = req;
307 _outcnt = _outmax = 0;
308 _class_id = Class_Node;
309 _flags = 0;
310 _out = NO_OUT_ARRAY;
311 return idx;
312 }
313
314 //------------------------------Node-------------------------------------------
315 // Create a Node, with a given number of required edges.
316 Node::Node(uint req)
317 : _idx(Init(req))
318 #ifdef ASSERT
319 , _parse_idx(_idx)
320 #endif
321 {
322 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
323 debug_only( verify_construction() );
324 NOT_PRODUCT(nodes_created++);
325 if (req == 0) {
326 _in = NULL;
327 } else {
328 Node** to = _in;
329 for(uint i = 0; i < req; i++) {
330 to[i] = NULL;
331 }
332 }
333 }
334
335 //------------------------------Node-------------------------------------------
336 Node::Node(Node *n0)
337 : _idx(Init(1))
338 #ifdef ASSERT
339 , _parse_idx(_idx)
340 #endif
341 {
342 debug_only( verify_construction() );
343 NOT_PRODUCT(nodes_created++);
344 assert( is_not_dead(n0), "can not use dead node");
345 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
346 }
347
348 //------------------------------Node-------------------------------------------
349 Node::Node(Node *n0, Node *n1)
350 : _idx(Init(2))
351 #ifdef ASSERT
352 , _parse_idx(_idx)
353 #endif
354 {
355 debug_only( verify_construction() );
356 NOT_PRODUCT(nodes_created++);
357 assert( is_not_dead(n0), "can not use dead node");
358 assert( is_not_dead(n1), "can not use dead node");
359 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
360 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
361 }
362
363 //------------------------------Node-------------------------------------------
364 Node::Node(Node *n0, Node *n1, Node *n2)
365 : _idx(Init(3))
366 #ifdef ASSERT
367 , _parse_idx(_idx)
368 #endif
369 {
370 debug_only( verify_construction() );
371 NOT_PRODUCT(nodes_created++);
372 assert( is_not_dead(n0), "can not use dead node");
373 assert( is_not_dead(n1), "can not use dead node");
374 assert( is_not_dead(n2), "can not use dead node");
375 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
376 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
377 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
378 }
379
380 //------------------------------Node-------------------------------------------
381 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
382 : _idx(Init(4))
383 #ifdef ASSERT
384 , _parse_idx(_idx)
385 #endif
386 {
387 debug_only( verify_construction() );
388 NOT_PRODUCT(nodes_created++);
389 assert( is_not_dead(n0), "can not use dead node");
390 assert( is_not_dead(n1), "can not use dead node");
391 assert( is_not_dead(n2), "can not use dead node");
392 assert( is_not_dead(n3), "can not use dead node");
393 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
394 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
395 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
396 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
397 }
398
399 //------------------------------Node-------------------------------------------
400 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
401 : _idx(Init(5))
402 #ifdef ASSERT
403 , _parse_idx(_idx)
404 #endif
405 {
406 debug_only( verify_construction() );
407 NOT_PRODUCT(nodes_created++);
408 assert( is_not_dead(n0), "can not use dead node");
409 assert( is_not_dead(n1), "can not use dead node");
410 assert( is_not_dead(n2), "can not use dead node");
411 assert( is_not_dead(n3), "can not use dead node");
412 assert( is_not_dead(n4), "can not use dead node");
413 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
414 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
415 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
416 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
417 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
418 }
419
420 //------------------------------Node-------------------------------------------
421 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
422 Node *n4, Node *n5)
423 : _idx(Init(6))
424 #ifdef ASSERT
425 , _parse_idx(_idx)
426 #endif
427 {
428 debug_only( verify_construction() );
429 NOT_PRODUCT(nodes_created++);
430 assert( is_not_dead(n0), "can not use dead node");
431 assert( is_not_dead(n1), "can not use dead node");
432 assert( is_not_dead(n2), "can not use dead node");
433 assert( is_not_dead(n3), "can not use dead node");
434 assert( is_not_dead(n4), "can not use dead node");
435 assert( is_not_dead(n5), "can not use dead node");
436 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
437 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
438 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
439 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
440 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
441 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
442 }
443
444 //------------------------------Node-------------------------------------------
445 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
446 Node *n4, Node *n5, Node *n6)
447 : _idx(Init(7))
448 #ifdef ASSERT
449 , _parse_idx(_idx)
450 #endif
451 {
452 debug_only( verify_construction() );
453 NOT_PRODUCT(nodes_created++);
454 assert( is_not_dead(n0), "can not use dead node");
455 assert( is_not_dead(n1), "can not use dead node");
456 assert( is_not_dead(n2), "can not use dead node");
457 assert( is_not_dead(n3), "can not use dead node");
458 assert( is_not_dead(n4), "can not use dead node");
459 assert( is_not_dead(n5), "can not use dead node");
460 assert( is_not_dead(n6), "can not use dead node");
461 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
462 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
463 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
464 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
465 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
466 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
467 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
468 }
469
470 #ifdef __clang__
471 #pragma clang diagnostic pop
472 #endif
473
474
475 //------------------------------clone------------------------------------------
476 // Clone a Node.
477 Node *Node::clone() const {
478 Compile* C = Compile::current();
479 uint s = size_of(); // Size of inherited Node
480 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
481 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
482 // Set the new input pointer array
483 n->_in = (Node**)(((char*)n)+s);
484 // Cannot share the old output pointer array, so kill it
485 n->_out = NO_OUT_ARRAY;
486 // And reset the counters to 0
487 n->_outcnt = 0;
488 n->_outmax = 0;
489 // Unlock this guy, since he is not in any hash table.
490 debug_only(n->_hash_lock = 0);
491 // Walk the old node's input list to duplicate its edges
492 uint i;
493 for( i = 0; i < len(); i++ ) {
494 Node *x = in(i);
495 n->_in[i] = x;
496 if (x != NULL) x->add_out(n);
497 }
498 if (is_macro())
499 C->add_macro_node(n);
500 if (is_expensive())
501 C->add_expensive_node(n);
502 // If the cloned node is a range check dependent CastII, add it to the list.
503 CastIINode* cast = n->isa_CastII();
504 if (cast != NULL && cast->has_range_check()) {
505 C->add_range_check_cast(cast);
506 }
507 if (n->Opcode() == Op_Opaque4) {
508 C->add_opaque4_node(n);
509 }
510
511 n->set_idx(C->next_unique()); // Get new unique index as well
512 debug_only( n->verify_construction() );
513 NOT_PRODUCT(nodes_created++);
514 // Do not patch over the debug_idx of a clone, because it makes it
515 // impossible to break on the clone's moment of creation.
516 //debug_only( n->set_debug_idx( debug_idx() ) );
517
518 C->copy_node_notes_to(n, (Node*) this);
519
520 // MachNode clone
521 uint nopnds;
522 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
523 MachNode *mach = n->as_Mach();
524 MachNode *mthis = this->as_Mach();
525 // Get address of _opnd_array.
526 // It should be the same offset since it is the clone of this node.
527 MachOper **from = mthis->_opnds;
528 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
529 pointer_delta((const void*)from,
530 (const void*)(&mthis->_opnds), 1));
531 mach->_opnds = to;
532 for ( uint i = 0; i < nopnds; ++i ) {
533 to[i] = from[i]->clone();
534 }
535 }
536 // cloning CallNode may need to clone JVMState
537 if (n->is_Call()) {
538 n->as_Call()->clone_jvms(C);
539 }
540 if (n->is_SafePoint()) {
541 n->as_SafePoint()->clone_replaced_nodes();
542 }
543 return n; // Return the clone
544 }
545
546 //---------------------------setup_is_top--------------------------------------
547 // Call this when changing the top node, to reassert the invariants
548 // required by Node::is_top. See Compile::set_cached_top_node.
549 void Node::setup_is_top() {
550 if (this == (Node*)Compile::current()->top()) {
551 // This node has just become top. Kill its out array.
552 _outcnt = _outmax = 0;
553 _out = NULL; // marker value for top
554 assert(is_top(), "must be top");
555 } else {
556 if (_out == NULL) _out = NO_OUT_ARRAY;
557 assert(!is_top(), "must not be top");
558 }
559 }
560
561
562 //------------------------------~Node------------------------------------------
563 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
564 void Node::destruct() {
565 // Eagerly reclaim unique Node numberings
566 Compile* compile = Compile::current();
567 if ((uint)_idx+1 == compile->unique()) {
568 compile->set_unique(compile->unique()-1);
569 }
570 // Clear debug info:
571 Node_Notes* nn = compile->node_notes_at(_idx);
572 if (nn != NULL) nn->clear();
573 // Walk the input array, freeing the corresponding output edges
574 _cnt = _max; // forget req/prec distinction
575 uint i;
576 for( i = 0; i < _max; i++ ) {
577 set_req(i, NULL);
578 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
579 }
580 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
581 // See if the input array was allocated just prior to the object
582 int edge_size = _max*sizeof(void*);
583 int out_edge_size = _outmax*sizeof(void*);
584 char *edge_end = ((char*)_in) + edge_size;
585 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
586 int node_size = size_of();
587
588 // Free the output edge array
589 if (out_edge_size > 0) {
590 compile->node_arena()->Afree(out_array, out_edge_size);
591 }
592
593 // Free the input edge array and the node itself
594 if( edge_end == (char*)this ) {
595 // It was; free the input array and object all in one hit
596 #ifndef ASSERT
597 compile->node_arena()->Afree(_in,edge_size+node_size);
598 #endif
599 } else {
600 // Free just the input array
601 compile->node_arena()->Afree(_in,edge_size);
602
603 // Free just the object
604 #ifndef ASSERT
605 compile->node_arena()->Afree(this,node_size);
606 #endif
607 }
608 if (is_macro()) {
609 compile->remove_macro_node(this);
610 }
611 if (is_expensive()) {
612 compile->remove_expensive_node(this);
613 }
614 CastIINode* cast = isa_CastII();
615 if (cast != NULL && cast->has_range_check()) {
616 compile->remove_range_check_cast(cast);
617 }
618 if (Opcode() == Op_Opaque4) {
619 compile->remove_opaque4_node(this);
620 }
621
622 if (is_SafePoint()) {
623 as_SafePoint()->delete_replaced_nodes();
624 }
625 #ifdef ASSERT
626 // We will not actually delete the storage, but we'll make the node unusable.
627 *(address*)this = badAddress; // smash the C++ vtbl, probably
628 _in = _out = (Node**) badAddress;
629 _max = _cnt = _outmax = _outcnt = 0;
630 compile->remove_modified_node(this);
631 #endif
632 }
633
634 //------------------------------grow-------------------------------------------
635 // Grow the input array, making space for more edges
636 void Node::grow( uint len ) {
637 Arena* arena = Compile::current()->node_arena();
638 uint new_max = _max;
639 if( new_max == 0 ) {
640 _max = 4;
641 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
642 Node** to = _in;
643 to[0] = NULL;
644 to[1] = NULL;
645 to[2] = NULL;
646 to[3] = NULL;
647 return;
648 }
649 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
650 // Trimming to limit allows a uint8 to handle up to 255 edges.
651 // Previously I was using only powers-of-2 which peaked at 128 edges.
652 //if( new_max >= limit ) new_max = limit-1;
653 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
654 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
655 _max = new_max; // Record new max length
656 // This assertion makes sure that Node::_max is wide enough to
657 // represent the numerical value of new_max.
658 assert(_max == new_max && _max > len, "int width of _max is too small");
659 }
660
661 //-----------------------------out_grow----------------------------------------
662 // Grow the input array, making space for more edges
663 void Node::out_grow( uint len ) {
664 assert(!is_top(), "cannot grow a top node's out array");
665 Arena* arena = Compile::current()->node_arena();
666 uint new_max = _outmax;
667 if( new_max == 0 ) {
668 _outmax = 4;
669 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
670 return;
671 }
672 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
673 // Trimming to limit allows a uint8 to handle up to 255 edges.
674 // Previously I was using only powers-of-2 which peaked at 128 edges.
675 //if( new_max >= limit ) new_max = limit-1;
676 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
677 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
678 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
679 _outmax = new_max; // Record new max length
680 // This assertion makes sure that Node::_max is wide enough to
681 // represent the numerical value of new_max.
682 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
683 }
684
685 #ifdef ASSERT
686 //------------------------------is_dead----------------------------------------
687 bool Node::is_dead() const {
688 // Mach and pinch point nodes may look like dead.
689 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
690 return false;
691 for( uint i = 0; i < _max; i++ )
692 if( _in[i] != NULL )
693 return false;
694 dump();
695 return true;
696 }
697 #endif
698
699
700 //------------------------------is_unreachable---------------------------------
701 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
702 assert(!is_Mach(), "doesn't work with MachNodes");
703 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != NULL && in(0)->is_top());
704 }
705
706 //------------------------------add_req----------------------------------------
707 // Add a new required input at the end
708 void Node::add_req( Node *n ) {
709 assert( is_not_dead(n), "can not use dead node");
710
711 // Look to see if I can move precedence down one without reallocating
712 if( (_cnt >= _max) || (in(_max-1) != NULL) )
713 grow( _max+1 );
714
715 // Find a precedence edge to move
716 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
717 uint i;
718 for( i=_cnt; i<_max; i++ )
719 if( in(i) == NULL ) // Find the NULL at end of prec edge list
720 break; // There must be one, since we grew the array
721 _in[i] = in(_cnt); // Move prec over, making space for req edge
722 }
723 _in[_cnt++] = n; // Stuff over old prec edge
724 if (n != NULL) n->add_out((Node *)this);
725 }
726
727 //---------------------------add_req_batch-------------------------------------
728 // Add a new required input at the end
729 void Node::add_req_batch( Node *n, uint m ) {
730 assert( is_not_dead(n), "can not use dead node");
731 // check various edge cases
732 if ((int)m <= 1) {
733 assert((int)m >= 0, "oob");
734 if (m != 0) add_req(n);
735 return;
736 }
737
738 // Look to see if I can move precedence down one without reallocating
739 if( (_cnt+m) > _max || _in[_max-m] )
740 grow( _max+m );
741
742 // Find a precedence edge to move
743 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
744 uint i;
745 for( i=_cnt; i<_max; i++ )
746 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
747 break; // There must be one, since we grew the array
748 // Slide all the precs over by m positions (assume #prec << m).
749 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
750 }
751
752 // Stuff over the old prec edges
753 for(uint i=0; i<m; i++ ) {
754 _in[_cnt++] = n;
755 }
756
757 // Insert multiple out edges on the node.
758 if (n != NULL && !n->is_top()) {
759 for(uint i=0; i<m; i++ ) {
760 n->add_out((Node *)this);
761 }
762 }
763 }
764
765 //------------------------------del_req----------------------------------------
766 // Delete the required edge and compact the edge array
767 void Node::del_req( uint idx ) {
768 assert( idx < _cnt, "oob");
769 assert( !VerifyHashTableKeys || _hash_lock == 0,
770 "remove node from hash table before modifying it");
771 // First remove corresponding def-use edge
772 Node *n = in(idx);
773 if (n != NULL) n->del_out((Node *)this);
774 _in[idx] = in(--_cnt); // Compact the array
775 // Avoid spec violation: Gap in prec edges.
776 close_prec_gap_at(_cnt);
777 Compile::current()->record_modified_node(this);
778 }
779
780 //------------------------------del_req_ordered--------------------------------
781 // Delete the required edge and compact the edge array with preserved order
782 void Node::del_req_ordered( uint idx ) {
783 assert( idx < _cnt, "oob");
784 assert( !VerifyHashTableKeys || _hash_lock == 0,
785 "remove node from hash table before modifying it");
786 // First remove corresponding def-use edge
787 Node *n = in(idx);
788 if (n != NULL) n->del_out((Node *)this);
789 if (idx < --_cnt) { // Not last edge ?
790 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
791 }
792 // Avoid spec violation: Gap in prec edges.
793 close_prec_gap_at(_cnt);
794 Compile::current()->record_modified_node(this);
795 }
796
797 //------------------------------ins_req----------------------------------------
798 // Insert a new required input at the end
799 void Node::ins_req( uint idx, Node *n ) {
800 assert( is_not_dead(n), "can not use dead node");
801 add_req(NULL); // Make space
802 assert( idx < _max, "Must have allocated enough space");
803 // Slide over
804 if(_cnt-idx-1 > 0) {
805 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
806 }
807 _in[idx] = n; // Stuff over old required edge
808 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
809 }
810
811 //-----------------------------find_edge---------------------------------------
812 int Node::find_edge(Node* n) {
813 for (uint i = 0; i < len(); i++) {
814 if (_in[i] == n) return i;
815 }
816 return -1;
817 }
818
819 //----------------------------replace_edge-------------------------------------
820 int Node::replace_edge(Node* old, Node* neww) {
821 if (old == neww) return 0; // nothing to do
822 uint nrep = 0;
823 for (uint i = 0; i < len(); i++) {
824 if (in(i) == old) {
825 if (i < req()) {
826 set_req(i, neww);
827 } else {
828 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
829 set_prec(i, neww);
830 }
831 nrep++;
832 }
833 }
834 return nrep;
835 }
836
837 /**
838 * Replace input edges in the range pointing to 'old' node.
839 */
840 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
841 if (old == neww) return 0; // nothing to do
842 uint nrep = 0;
843 for (int i = start; i < end; i++) {
844 if (in(i) == old) {
845 set_req(i, neww);
846 nrep++;
847 }
848 }
849 return nrep;
850 }
851
852 //-------------------------disconnect_inputs-----------------------------------
853 // NULL out all inputs to eliminate incoming Def-Use edges.
854 // Return the number of edges between 'n' and 'this'
855 int Node::disconnect_inputs(Node *n, Compile* C) {
856 int edges_to_n = 0;
857
858 uint cnt = req();
859 for( uint i = 0; i < cnt; ++i ) {
860 if( in(i) == 0 ) continue;
861 if( in(i) == n ) ++edges_to_n;
862 set_req(i, NULL);
863 }
864 // Remove precedence edges if any exist
865 // Note: Safepoints may have precedence edges, even during parsing
866 if( (req() != len()) && (in(req()) != NULL) ) {
867 uint max = len();
868 for( uint i = 0; i < max; ++i ) {
869 if( in(i) == 0 ) continue;
870 if( in(i) == n ) ++edges_to_n;
871 set_prec(i, NULL);
872 }
873 }
874
875 // Node::destruct requires all out edges be deleted first
876 // debug_only(destruct();) // no reuse benefit expected
877 if (edges_to_n == 0) {
878 C->record_dead_node(_idx);
879 }
880 return edges_to_n;
881 }
882
883 //-----------------------------uncast---------------------------------------
884 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
885 // Strip away casting. (It is depth-limited.)
886 Node* Node::uncast() const {
887 // Should be inline:
888 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
889 if (is_ConstraintCast())
890 return uncast_helper(this);
891 else
892 return (Node*) this;
893 }
894
895 // Find out of current node that matches opcode.
896 Node* Node::find_out_with(int opcode) {
897 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
898 Node* use = fast_out(i);
899 if (use->Opcode() == opcode) {
900 return use;
901 }
902 }
903 return NULL;
904 }
905
906 // Return true if the current node has an out that matches opcode.
907 bool Node::has_out_with(int opcode) {
908 return (find_out_with(opcode) != NULL);
909 }
910
911 // Return true if the current node has an out that matches any of the opcodes.
912 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
913 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
914 int opcode = fast_out(i)->Opcode();
915 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
916 return true;
917 }
918 }
919 return false;
920 }
921
922
923 //---------------------------uncast_helper-------------------------------------
924 Node* Node::uncast_helper(const Node* p) {
925 #ifdef ASSERT
926 uint depth_count = 0;
927 const Node* orig_p = p;
928 #endif
929
930 while (true) {
931 #ifdef ASSERT
932 if (depth_count >= K) {
933 orig_p->dump(4);
934 if (p != orig_p)
935 p->dump(1);
936 }
937 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
938 #endif
939 if (p == NULL || p->req() != 2) {
940 break;
941 } else if (p->is_ConstraintCast()) {
942 p = p->in(1);
943 } else {
944 break;
945 }
946 }
947 return (Node*) p;
948 }
949
950 //------------------------------add_prec---------------------------------------
951 // Add a new precedence input. Precedence inputs are unordered, with
952 // duplicates removed and NULLs packed down at the end.
953 void Node::add_prec( Node *n ) {
954 assert( is_not_dead(n), "can not use dead node");
955
956 // Check for NULL at end
957 if( _cnt >= _max || in(_max-1) )
958 grow( _max+1 );
959
960 // Find a precedence edge to move
961 uint i = _cnt;
962 while( in(i) != NULL ) {
963 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
964 i++;
965 }
966 _in[i] = n; // Stuff prec edge over NULL
967 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
968
969 #ifdef ASSERT
970 while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
971 #endif
972 }
973
974 //------------------------------rm_prec----------------------------------------
975 // Remove a precedence input. Precedence inputs are unordered, with
976 // duplicates removed and NULLs packed down at the end.
977 void Node::rm_prec( uint j ) {
978 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
979 assert(j >= _cnt, "not a precedence edge");
980 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
981 _in[j]->del_out((Node *)this);
982 close_prec_gap_at(j);
983 }
984
985 //------------------------------size_of----------------------------------------
986 uint Node::size_of() const { return sizeof(*this); }
987
988 //------------------------------ideal_reg--------------------------------------
989 uint Node::ideal_reg() const { return 0; }
990
991 //------------------------------jvms-------------------------------------------
992 JVMState* Node::jvms() const { return NULL; }
993
994 #ifdef ASSERT
995 //------------------------------jvms-------------------------------------------
996 bool Node::verify_jvms(const JVMState* using_jvms) const {
997 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
998 if (jvms == using_jvms) return true;
999 }
1000 return false;
1001 }
1002
1003 //------------------------------init_NodeProperty------------------------------
1004 void Node::init_NodeProperty() {
1005 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1006 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1007 }
1008 #endif
1009
1010 //------------------------------format-----------------------------------------
1011 // Print as assembly
1012 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1013 //------------------------------emit-------------------------------------------
1014 // Emit bytes starting at parameter 'ptr'.
1015 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1016 //------------------------------size-------------------------------------------
1017 // Size of instruction in bytes
1018 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1019
1020 //------------------------------CFG Construction-------------------------------
1021 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1022 // Goto and Return.
1023 const Node *Node::is_block_proj() const { return 0; }
1024
1025 // Minimum guaranteed type
1026 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1027
1028
1029 //------------------------------raise_bottom_type------------------------------
1030 // Get the worst-case Type output for this Node.
1031 void Node::raise_bottom_type(const Type* new_type) {
1032 if (is_Type()) {
1033 TypeNode *n = this->as_Type();
1034 if (VerifyAliases) {
1035 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1036 }
1037 n->set_type(new_type);
1038 } else if (is_Load()) {
1039 LoadNode *n = this->as_Load();
1040 if (VerifyAliases) {
1041 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1042 }
1043 n->set_type(new_type);
1044 }
1045 }
1046
1047 //------------------------------Identity---------------------------------------
1048 // Return a node that the given node is equivalent to.
1049 Node* Node::Identity(PhaseGVN* phase) {
1050 return this; // Default to no identities
1051 }
1052
1053 //------------------------------Value------------------------------------------
1054 // Compute a new Type for a node using the Type of the inputs.
1055 const Type* Node::Value(PhaseGVN* phase) const {
1056 return bottom_type(); // Default to worst-case Type
1057 }
1058
1059 //------------------------------Ideal------------------------------------------
1060 //
1061 // 'Idealize' the graph rooted at this Node.
1062 //
1063 // In order to be efficient and flexible there are some subtle invariants
1064 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1065 // these invariants, although its too slow to have on by default. If you are
1066 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1067 //
1068 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1069 // pointer. If ANY change is made, it must return the root of the reshaped
1070 // graph - even if the root is the same Node. Example: swapping the inputs
1071 // to an AddINode gives the same answer and same root, but you still have to
1072 // return the 'this' pointer instead of NULL.
1073 //
1074 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1075 // Identity call to return an old Node; basically if Identity can find
1076 // another Node have the Ideal call make no change and return NULL.
1077 // Example: AddINode::Ideal must check for add of zero; in this case it
1078 // returns NULL instead of doing any graph reshaping.
1079 //
1080 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1081 // sharing there may be other users of the old Nodes relying on their current
1082 // semantics. Modifying them will break the other users.
1083 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1084 // "X+3" unchanged in case it is shared.
1085 //
1086 // If you modify the 'this' pointer's inputs, you should use
1087 // 'set_req'. If you are making a new Node (either as the new root or
1088 // some new internal piece) you may use 'init_req' to set the initial
1089 // value. You can make a new Node with either 'new' or 'clone'. In
1090 // either case, def-use info is correctly maintained.
1091 //
1092 // Example: reshape "(X+3)+4" into "X+7":
1093 // set_req(1, in(1)->in(1));
1094 // set_req(2, phase->intcon(7));
1095 // return this;
1096 // Example: reshape "X*4" into "X<<2"
1097 // return new LShiftINode(in(1), phase->intcon(2));
1098 //
1099 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1100 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1101 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1102 // return new AddINode(shift, in(1));
1103 //
1104 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1105 // These forms are faster than 'phase->transform(new ConNode())' and Do
1106 // The Right Thing with def-use info.
1107 //
1108 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1109 // graph uses the 'this' Node it must be the root. If you want a Node with
1110 // the same Opcode as the 'this' pointer use 'clone'.
1111 //
1112 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1113 return NULL; // Default to being Ideal already
1114 }
1115
1116 // Some nodes have specific Ideal subgraph transformations only if they are
1117 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1118 // for the transformations to happen.
1119 bool Node::has_special_unique_user() const {
1120 assert(outcnt() == 1, "match only for unique out");
1121 Node* n = unique_out();
1122 int op = Opcode();
1123 if (this->is_Store()) {
1124 // Condition for back-to-back stores folding.
1125 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1126 } else if (this->is_Load() || this->is_DecodeN()) {
1127 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1128 return n->Opcode() == Op_MemBarAcquire;
1129 } else if (op == Op_AddL) {
1130 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1131 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1132 } else if (op == Op_SubI || op == Op_SubL) {
1133 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1134 return n->Opcode() == op && n->in(2) == this;
1135 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1136 // See IfProjNode::Identity()
1137 return true;
1138 }
1139 return false;
1140 };
1141
1142 //--------------------------find_exact_control---------------------------------
1143 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1144 Node* Node::find_exact_control(Node* ctrl) {
1145 if (ctrl == NULL && this->is_Region())
1146 ctrl = this->as_Region()->is_copy();
1147
1148 if (ctrl != NULL && ctrl->is_CatchProj()) {
1149 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1150 ctrl = ctrl->in(0);
1151 if (ctrl != NULL && !ctrl->is_top())
1152 ctrl = ctrl->in(0);
1153 }
1154
1155 if (ctrl != NULL && ctrl->is_Proj())
1156 ctrl = ctrl->in(0);
1157
1158 return ctrl;
1159 }
1160
1161 //--------------------------dominates------------------------------------------
1162 // Helper function for MemNode::all_controls_dominate().
1163 // Check if 'this' control node dominates or equal to 'sub' control node.
1164 // We already know that if any path back to Root or Start reaches 'this',
1165 // then all paths so, so this is a simple search for one example,
1166 // not an exhaustive search for a counterexample.
1167 bool Node::dominates(Node* sub, Node_List &nlist) {
1168 assert(this->is_CFG(), "expecting control");
1169 assert(sub != NULL && sub->is_CFG(), "expecting control");
1170
1171 // detect dead cycle without regions
1172 int iterations_without_region_limit = DominatorSearchLimit;
1173
1174 Node* orig_sub = sub;
1175 Node* dom = this;
1176 bool met_dom = false;
1177 nlist.clear();
1178
1179 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1180 // After seeing 'dom', continue up to Root or Start.
1181 // If we hit a region (backward split point), it may be a loop head.
1182 // Keep going through one of the region's inputs. If we reach the
1183 // same region again, go through a different input. Eventually we
1184 // will either exit through the loop head, or give up.
1185 // (If we get confused, break out and return a conservative 'false'.)
1186 while (sub != NULL) {
1187 if (sub->is_top()) break; // Conservative answer for dead code.
1188 if (sub == dom) {
1189 if (nlist.size() == 0) {
1190 // No Region nodes except loops were visited before and the EntryControl
1191 // path was taken for loops: it did not walk in a cycle.
1192 return true;
1193 } else if (met_dom) {
1194 break; // already met before: walk in a cycle
1195 } else {
1196 // Region nodes were visited. Continue walk up to Start or Root
1197 // to make sure that it did not walk in a cycle.
1198 met_dom = true; // first time meet
1199 iterations_without_region_limit = DominatorSearchLimit; // Reset
1200 }
1201 }
1202 if (sub->is_Start() || sub->is_Root()) {
1203 // Success if we met 'dom' along a path to Start or Root.
1204 // We assume there are no alternative paths that avoid 'dom'.
1205 // (This assumption is up to the caller to ensure!)
1206 return met_dom;
1207 }
1208 Node* up = sub->in(0);
1209 // Normalize simple pass-through regions and projections:
1210 up = sub->find_exact_control(up);
1211 // If sub == up, we found a self-loop. Try to push past it.
1212 if (sub == up && sub->is_Loop()) {
1213 // Take loop entry path on the way up to 'dom'.
1214 up = sub->in(1); // in(LoopNode::EntryControl);
1215 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1216 // Always take in(1) path on the way up to 'dom' for clone regions
1217 // (with only one input) or regions which merge > 2 paths
1218 // (usually used to merge fast/slow paths).
1219 up = sub->in(1);
1220 } else if (sub == up && sub->is_Region()) {
1221 // Try both paths for Regions with 2 input paths (it may be a loop head).
1222 // It could give conservative 'false' answer without information
1223 // which region's input is the entry path.
1224 iterations_without_region_limit = DominatorSearchLimit; // Reset
1225
1226 bool region_was_visited_before = false;
1227 // Was this Region node visited before?
1228 // If so, we have reached it because we accidentally took a
1229 // loop-back edge from 'sub' back into the body of the loop,
1230 // and worked our way up again to the loop header 'sub'.
1231 // So, take the first unexplored path on the way up to 'dom'.
1232 for (int j = nlist.size() - 1; j >= 0; j--) {
1233 intptr_t ni = (intptr_t)nlist.at(j);
1234 Node* visited = (Node*)(ni & ~1);
1235 bool visited_twice_already = ((ni & 1) != 0);
1236 if (visited == sub) {
1237 if (visited_twice_already) {
1238 // Visited 2 paths, but still stuck in loop body. Give up.
1239 return false;
1240 }
1241 // The Region node was visited before only once.
1242 // (We will repush with the low bit set, below.)
1243 nlist.remove(j);
1244 // We will find a new edge and re-insert.
1245 region_was_visited_before = true;
1246 break;
1247 }
1248 }
1249
1250 // Find an incoming edge which has not been seen yet; walk through it.
1251 assert(up == sub, "");
1252 uint skip = region_was_visited_before ? 1 : 0;
1253 for (uint i = 1; i < sub->req(); i++) {
1254 Node* in = sub->in(i);
1255 if (in != NULL && !in->is_top() && in != sub) {
1256 if (skip == 0) {
1257 up = in;
1258 break;
1259 }
1260 --skip; // skip this nontrivial input
1261 }
1262 }
1263
1264 // Set 0 bit to indicate that both paths were taken.
1265 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1266 }
1267
1268 if (up == sub) {
1269 break; // some kind of tight cycle
1270 }
1271 if (up == orig_sub && met_dom) {
1272 // returned back after visiting 'dom'
1273 break; // some kind of cycle
1274 }
1275 if (--iterations_without_region_limit < 0) {
1276 break; // dead cycle
1277 }
1278 sub = up;
1279 }
1280
1281 // Did not meet Root or Start node in pred. chain.
1282 // Conservative answer for dead code.
1283 return false;
1284 }
1285
1286 //------------------------------remove_dead_region-----------------------------
1287 // This control node is dead. Follow the subgraph below it making everything
1288 // using it dead as well. This will happen normally via the usual IterGVN
1289 // worklist but this call is more efficient. Do not update use-def info
1290 // inside the dead region, just at the borders.
1291 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1292 // Con's are a popular node to re-hit in the hash table again.
1293 if( dead->is_Con() ) return;
1294
1295 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1296 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1297 Node_List nstack(Thread::current()->resource_area());
1298
1299 Node *top = igvn->C->top();
1300 nstack.push(dead);
1301 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1302
1303 while (nstack.size() > 0) {
1304 dead = nstack.pop();
1305 if (dead->outcnt() > 0) {
1306 // Keep dead node on stack until all uses are processed.
1307 nstack.push(dead);
1308 // For all Users of the Dead... ;-)
1309 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1310 Node* use = dead->last_out(k);
1311 igvn->hash_delete(use); // Yank from hash table prior to mod
1312 if (use->in(0) == dead) { // Found another dead node
1313 assert (!use->is_Con(), "Control for Con node should be Root node.");
1314 use->set_req(0, top); // Cut dead edge to prevent processing
1315 nstack.push(use); // the dead node again.
1316 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1317 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1318 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1319 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1320 use->set_req(0, top); // Cut self edge
1321 nstack.push(use);
1322 } else { // Else found a not-dead user
1323 // Dead if all inputs are top or null
1324 bool dead_use = !use->is_Root(); // Keep empty graph alive
1325 for (uint j = 1; j < use->req(); j++) {
1326 Node* in = use->in(j);
1327 if (in == dead) { // Turn all dead inputs into TOP
1328 use->set_req(j, top);
1329 } else if (in != NULL && !in->is_top()) {
1330 dead_use = false;
1331 }
1332 }
1333 if (dead_use) {
1334 if (use->is_Region()) {
1335 use->set_req(0, top); // Cut self edge
1336 }
1337 nstack.push(use);
1338 } else {
1339 igvn->_worklist.push(use);
1340 }
1341 }
1342 // Refresh the iterator, since any number of kills might have happened.
1343 k = dead->last_outs(kmin);
1344 }
1345 } else { // (dead->outcnt() == 0)
1346 // Done with outputs.
1347 igvn->hash_delete(dead);
1348 igvn->_worklist.remove(dead);
1349 igvn->C->remove_modified_node(dead);
1350 igvn->set_type(dead, Type::TOP);
1351 if (dead->is_macro()) {
1352 igvn->C->remove_macro_node(dead);
1353 }
1354 if (dead->is_expensive()) {
1355 igvn->C->remove_expensive_node(dead);
1356 }
1357 CastIINode* cast = dead->isa_CastII();
1358 if (cast != NULL && cast->has_range_check()) {
1359 igvn->C->remove_range_check_cast(cast);
1360 }
1361 if (dead->Opcode() == Op_Opaque4) {
1362 igvn->C->remove_range_check_cast(dead);
1363 }
1364 igvn->C->record_dead_node(dead->_idx);
1365 // Kill all inputs to the dead guy
1366 for (uint i=0; i < dead->req(); i++) {
1367 Node *n = dead->in(i); // Get input to dead guy
1368 if (n != NULL && !n->is_top()) { // Input is valid?
1369 dead->set_req(i, top); // Smash input away
1370 if (n->outcnt() == 0) { // Input also goes dead?
1371 if (!n->is_Con())
1372 nstack.push(n); // Clear it out as well
1373 } else if (n->outcnt() == 1 &&
1374 n->has_special_unique_user()) {
1375 igvn->add_users_to_worklist( n );
1376 } else if (n->outcnt() <= 2 && n->is_Store()) {
1377 // Push store's uses on worklist to enable folding optimization for
1378 // store/store and store/load to the same address.
1379 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1380 // and remove_globally_dead_node().
1381 igvn->add_users_to_worklist( n );
1382 }
1383 }
1384 }
1385 } // (dead->outcnt() == 0)
1386 } // while (nstack.size() > 0) for outputs
1387 return;
1388 }
1389
1390 //------------------------------remove_dead_region-----------------------------
1391 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1392 Node *n = in(0);
1393 if( !n ) return false;
1394 // Lost control into this guy? I.e., it became unreachable?
1395 // Aggressively kill all unreachable code.
1396 if (can_reshape && n->is_top()) {
1397 kill_dead_code(this, phase->is_IterGVN());
1398 return false; // Node is dead.
1399 }
1400
1401 if( n->is_Region() && n->as_Region()->is_copy() ) {
1402 Node *m = n->nonnull_req();
1403 set_req(0, m);
1404 return true;
1405 }
1406 return false;
1407 }
1408
1409 //------------------------------hash-------------------------------------------
1410 // Hash function over Nodes.
1411 uint Node::hash() const {
1412 uint sum = 0;
1413 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1414 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1415 return (sum>>2) + _cnt + Opcode();
1416 }
1417
1418 //------------------------------cmp--------------------------------------------
1419 // Compare special parts of simple Nodes
1420 uint Node::cmp( const Node &n ) const {
1421 return 1; // Must be same
1422 }
1423
1424 //------------------------------rematerialize-----------------------------------
1425 // Should we clone rather than spill this instruction?
1426 bool Node::rematerialize() const {
1427 if ( is_Mach() )
1428 return this->as_Mach()->rematerialize();
1429 else
1430 return (_flags & Flag_rematerialize) != 0;
1431 }
1432
1433 //------------------------------needs_anti_dependence_check---------------------
1434 // Nodes which use memory without consuming it, hence need antidependences.
1435 bool Node::needs_anti_dependence_check() const {
1436 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1437 return false;
1438 else
1439 return in(1)->bottom_type()->has_memory();
1440 }
1441
1442
1443 // Get an integer constant from a ConNode (or CastIINode).
1444 // Return a default value if there is no apparent constant here.
1445 const TypeInt* Node::find_int_type() const {
1446 if (this->is_Type()) {
1447 return this->as_Type()->type()->isa_int();
1448 } else if (this->is_Con()) {
1449 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1450 return this->bottom_type()->isa_int();
1451 }
1452 return NULL;
1453 }
1454
1455 // Get a pointer constant from a ConstNode.
1456 // Returns the constant if it is a pointer ConstNode
1457 intptr_t Node::get_ptr() const {
1458 assert( Opcode() == Op_ConP, "" );
1459 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1460 }
1461
1462 // Get a narrow oop constant from a ConNNode.
1463 intptr_t Node::get_narrowcon() const {
1464 assert( Opcode() == Op_ConN, "" );
1465 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1466 }
1467
1468 // Get a long constant from a ConNode.
1469 // Return a default value if there is no apparent constant here.
1470 const TypeLong* Node::find_long_type() const {
1471 if (this->is_Type()) {
1472 return this->as_Type()->type()->isa_long();
1473 } else if (this->is_Con()) {
1474 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1475 return this->bottom_type()->isa_long();
1476 }
1477 return NULL;
1478 }
1479
1480
1481 /**
1482 * Return a ptr type for nodes which should have it.
1483 */
1484 const TypePtr* Node::get_ptr_type() const {
1485 const TypePtr* tp = this->bottom_type()->make_ptr();
1486 #ifdef ASSERT
1487 if (tp == NULL) {
1488 this->dump(1);
1489 assert((tp != NULL), "unexpected node type");
1490 }
1491 #endif
1492 return tp;
1493 }
1494
1495 // Get a double constant from a ConstNode.
1496 // Returns the constant if it is a double ConstNode
1497 jdouble Node::getd() const {
1498 assert( Opcode() == Op_ConD, "" );
1499 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1500 }
1501
1502 // Get a float constant from a ConstNode.
1503 // Returns the constant if it is a float ConstNode
1504 jfloat Node::getf() const {
1505 assert( Opcode() == Op_ConF, "" );
1506 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1507 }
1508
1509 #ifndef PRODUCT
1510
1511 //------------------------------find------------------------------------------
1512 // Find a neighbor of this Node with the given _idx
1513 // If idx is negative, find its absolute value, following both _in and _out.
1514 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1515 VectorSet* old_space, VectorSet* new_space ) {
1516 int node_idx = (idx >= 0) ? idx : -idx;
1517 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1518 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1519 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1520 if( v->test(n->_idx) ) return;
1521 if( (int)n->_idx == node_idx
1522 debug_only(|| n->debug_idx() == node_idx) ) {
1523 if (result != NULL)
1524 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1525 (uintptr_t)result, (uintptr_t)n, node_idx);
1526 result = n;
1527 }
1528 v->set(n->_idx);
1529 for( uint i=0; i<n->len(); i++ ) {
1530 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1531 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1532 }
1533 // Search along forward edges also:
1534 if (idx < 0 && !only_ctrl) {
1535 for( uint j=0; j<n->outcnt(); j++ ) {
1536 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1537 }
1538 }
1539 #ifdef ASSERT
1540 // Search along debug_orig edges last, checking for cycles
1541 Node* orig = n->debug_orig();
1542 if (orig != NULL) {
1543 do {
1544 if (NotANode(orig)) break;
1545 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1546 orig = orig->debug_orig();
1547 } while (orig != NULL && orig != n->debug_orig());
1548 }
1549 #endif //ASSERT
1550 }
1551
1552 // call this from debugger:
1553 Node* find_node(Node* n, int idx) {
1554 return n->find(idx);
1555 }
1556
1557 //------------------------------find-------------------------------------------
1558 Node* Node::find(int idx) const {
1559 ResourceArea *area = Thread::current()->resource_area();
1560 VectorSet old_space(area), new_space(area);
1561 Node* result = NULL;
1562 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1563 return result;
1564 }
1565
1566 //------------------------------find_ctrl--------------------------------------
1567 // Find an ancestor to this node in the control history with given _idx
1568 Node* Node::find_ctrl(int idx) const {
1569 ResourceArea *area = Thread::current()->resource_area();
1570 VectorSet old_space(area), new_space(area);
1571 Node* result = NULL;
1572 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1573 return result;
1574 }
1575 #endif
1576
1577
1578
1579 #ifndef PRODUCT
1580
1581 // -----------------------------Name-------------------------------------------
1582 extern const char *NodeClassNames[];
1583 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1584
1585 static bool is_disconnected(const Node* n) {
1586 for (uint i = 0; i < n->req(); i++) {
1587 if (n->in(i) != NULL) return false;
1588 }
1589 return true;
1590 }
1591
1592 #ifdef ASSERT
1593 static void dump_orig(Node* orig, outputStream *st) {
1594 Compile* C = Compile::current();
1595 if (NotANode(orig)) orig = NULL;
1596 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1597 if (orig == NULL) return;
1598 st->print(" !orig=");
1599 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1600 if (NotANode(fast)) fast = NULL;
1601 while (orig != NULL) {
1602 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1603 if (discon) st->print("[");
1604 if (!Compile::current()->node_arena()->contains(orig))
1605 st->print("o");
1606 st->print("%d", orig->_idx);
1607 if (discon) st->print("]");
1608 orig = orig->debug_orig();
1609 if (NotANode(orig)) orig = NULL;
1610 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1611 if (orig != NULL) st->print(",");
1612 if (fast != NULL) {
1613 // Step fast twice for each single step of orig:
1614 fast = fast->debug_orig();
1615 if (NotANode(fast)) fast = NULL;
1616 if (fast != NULL && fast != orig) {
1617 fast = fast->debug_orig();
1618 if (NotANode(fast)) fast = NULL;
1619 }
1620 if (fast == orig) {
1621 st->print("...");
1622 break;
1623 }
1624 }
1625 }
1626 }
1627
1628 void Node::set_debug_orig(Node* orig) {
1629 _debug_orig = orig;
1630 if (BreakAtNode == 0) return;
1631 if (NotANode(orig)) orig = NULL;
1632 int trip = 10;
1633 while (orig != NULL) {
1634 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1635 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1636 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1637 BREAKPOINT;
1638 }
1639 orig = orig->debug_orig();
1640 if (NotANode(orig)) orig = NULL;
1641 if (trip-- <= 0) break;
1642 }
1643 }
1644 #endif //ASSERT
1645
1646 //------------------------------dump------------------------------------------
1647 // Dump a Node
1648 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1649 Compile* C = Compile::current();
1650 bool is_new = C->node_arena()->contains(this);
1651 C->_in_dump_cnt++;
1652 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1653
1654 // Dump the required and precedence inputs
1655 dump_req(st);
1656 dump_prec(st);
1657 // Dump the outputs
1658 dump_out(st);
1659
1660 if (is_disconnected(this)) {
1661 #ifdef ASSERT
1662 st->print(" [%d]",debug_idx());
1663 dump_orig(debug_orig(), st);
1664 #endif
1665 st->cr();
1666 C->_in_dump_cnt--;
1667 return; // don't process dead nodes
1668 }
1669
1670 if (C->clone_map().value(_idx) != 0) {
1671 C->clone_map().dump(_idx);
1672 }
1673 // Dump node-specific info
1674 dump_spec(st);
1675 #ifdef ASSERT
1676 // Dump the non-reset _debug_idx
1677 if (Verbose && WizardMode) {
1678 st->print(" [%d]",debug_idx());
1679 }
1680 #endif
1681
1682 const Type *t = bottom_type();
1683
1684 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1685 const TypeInstPtr *toop = t->isa_instptr();
1686 const TypeKlassPtr *tkls = t->isa_klassptr();
1687 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1688 if (klass && klass->is_loaded() && klass->is_interface()) {
1689 st->print(" Interface:");
1690 } else if (toop) {
1691 st->print(" Oop:");
1692 } else if (tkls) {
1693 st->print(" Klass:");
1694 }
1695 t->dump_on(st);
1696 } else if (t == Type::MEMORY) {
1697 st->print(" Memory:");
1698 MemNode::dump_adr_type(this, adr_type(), st);
1699 } else if (Verbose || WizardMode) {
1700 st->print(" Type:");
1701 if (t) {
1702 t->dump_on(st);
1703 } else {
1704 st->print("no type");
1705 }
1706 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1707 // Dump MachSpillcopy vector type.
1708 t->dump_on(st);
1709 }
1710 if (is_new) {
1711 debug_only(dump_orig(debug_orig(), st));
1712 Node_Notes* nn = C->node_notes_at(_idx);
1713 if (nn != NULL && !nn->is_clear()) {
1714 if (nn->jvms() != NULL) {
1715 st->print(" !jvms:");
1716 nn->jvms()->dump_spec(st);
1717 }
1718 }
1719 }
1720 if (suffix) st->print("%s", suffix);
1721 C->_in_dump_cnt--;
1722 }
1723
1724 //------------------------------dump_req--------------------------------------
1725 void Node::dump_req(outputStream *st) const {
1726 // Dump the required input edges
1727 for (uint i = 0; i < req(); i++) { // For all required inputs
1728 Node* d = in(i);
1729 if (d == NULL) {
1730 st->print("_ ");
1731 } else if (NotANode(d)) {
1732 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1733 } else {
1734 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1735 }
1736 }
1737 }
1738
1739
1740 //------------------------------dump_prec-------------------------------------
1741 void Node::dump_prec(outputStream *st) const {
1742 // Dump the precedence edges
1743 int any_prec = 0;
1744 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1745 Node* p = in(i);
1746 if (p != NULL) {
1747 if (!any_prec++) st->print(" |");
1748 if (NotANode(p)) { st->print("NotANode "); continue; }
1749 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1750 }
1751 }
1752 }
1753
1754 //------------------------------dump_out--------------------------------------
1755 void Node::dump_out(outputStream *st) const {
1756 // Delimit the output edges
1757 st->print(" [[");
1758 // Dump the output edges
1759 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1760 Node* u = _out[i];
1761 if (u == NULL) {
1762 st->print("_ ");
1763 } else if (NotANode(u)) {
1764 st->print("NotANode ");
1765 } else {
1766 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1767 }
1768 }
1769 st->print("]] ");
1770 }
1771
1772 //----------------------------collect_nodes_i----------------------------------
1773 // Collects nodes from an Ideal graph, starting from a given start node and
1774 // moving in a given direction until a certain depth (distance from the start
1775 // node) is reached. Duplicates are ignored.
1776 // Arguments:
1777 // nstack: the nodes are collected into this array.
1778 // start: the node at which to start collecting.
1779 // direction: if this is a positive number, collect input nodes; if it is
1780 // a negative number, collect output nodes.
1781 // depth: collect nodes up to this distance from the start node.
1782 // include_start: whether to include the start node in the result collection.
1783 // only_ctrl: whether to regard control edges only during traversal.
1784 // only_data: whether to regard data edges only during traversal.
1785 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1786 Node* s = (Node*) start; // remove const
1787 nstack->append(s);
1788 int begin = 0;
1789 int end = 0;
1790 for(uint i = 0; i < depth; i++) {
1791 end = nstack->length();
1792 for(int j = begin; j < end; j++) {
1793 Node* tp = nstack->at(j);
1794 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1795 for(uint k = 0; k < limit; k++) {
1796 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1797
1798 if (NotANode(n)) continue;
1799 // do not recurse through top or the root (would reach unrelated stuff)
1800 if (n->is_Root() || n->is_top()) continue;
1801 if (only_ctrl && !n->is_CFG()) continue;
1802 if (only_data && n->is_CFG()) continue;
1803
1804 bool on_stack = nstack->contains(n);
1805 if (!on_stack) {
1806 nstack->append(n);
1807 }
1808 }
1809 }
1810 begin = end;
1811 }
1812 if (!include_start) {
1813 nstack->remove(s);
1814 }
1815 }
1816
1817 //------------------------------dump_nodes-------------------------------------
1818 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1819 if (NotANode(start)) return;
1820
1821 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1822 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1823
1824 int end = nstack.length();
1825 if (d > 0) {
1826 for(int j = end-1; j >= 0; j--) {
1827 nstack.at(j)->dump();
1828 }
1829 } else {
1830 for(int j = 0; j < end; j++) {
1831 nstack.at(j)->dump();
1832 }
1833 }
1834 }
1835
1836 //------------------------------dump-------------------------------------------
1837 void Node::dump(int d) const {
1838 dump_nodes(this, d, false);
1839 }
1840
1841 //------------------------------dump_ctrl--------------------------------------
1842 // Dump a Node's control history to depth
1843 void Node::dump_ctrl(int d) const {
1844 dump_nodes(this, d, true);
1845 }
1846
1847 //-----------------------------dump_compact------------------------------------
1848 void Node::dump_comp() const {
1849 this->dump_comp("\n");
1850 }
1851
1852 //-----------------------------dump_compact------------------------------------
1853 // Dump a Node in compact representation, i.e., just print its name and index.
1854 // Nodes can specify additional specifics to print in compact representation by
1855 // implementing dump_compact_spec.
1856 void Node::dump_comp(const char* suffix, outputStream *st) const {
1857 Compile* C = Compile::current();
1858 C->_in_dump_cnt++;
1859 st->print("%s(%d)", Name(), _idx);
1860 this->dump_compact_spec(st);
1861 if (suffix) {
1862 st->print("%s", suffix);
1863 }
1864 C->_in_dump_cnt--;
1865 }
1866
1867 //----------------------------dump_related-------------------------------------
1868 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1869 // hand and is determined by the implementation of the virtual method rel.
1870 void Node::dump_related() const {
1871 Compile* C = Compile::current();
1872 GrowableArray <Node *> in_rel(C->unique());
1873 GrowableArray <Node *> out_rel(C->unique());
1874 this->related(&in_rel, &out_rel, false);
1875 for (int i = in_rel.length() - 1; i >= 0; i--) {
1876 in_rel.at(i)->dump();
1877 }
1878 this->dump("\n", true);
1879 for (int i = 0; i < out_rel.length(); i++) {
1880 out_rel.at(i)->dump();
1881 }
1882 }
1883
1884 //----------------------------dump_related-------------------------------------
1885 // Dump a Node's related nodes up to a given depth (distance from the start
1886 // node).
1887 // Arguments:
1888 // d_in: depth for input nodes.
1889 // d_out: depth for output nodes (note: this also is a positive number).
1890 void Node::dump_related(uint d_in, uint d_out) const {
1891 Compile* C = Compile::current();
1892 GrowableArray <Node *> in_rel(C->unique());
1893 GrowableArray <Node *> out_rel(C->unique());
1894
1895 // call collect_nodes_i directly
1896 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1897 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1898
1899 for (int i = in_rel.length() - 1; i >= 0; i--) {
1900 in_rel.at(i)->dump();
1901 }
1902 this->dump("\n", true);
1903 for (int i = 0; i < out_rel.length(); i++) {
1904 out_rel.at(i)->dump();
1905 }
1906 }
1907
1908 //------------------------dump_related_compact---------------------------------
1909 // Dump a Node's related nodes in compact representation. The notion of
1910 // "related" depends on the Node at hand and is determined by the implementation
1911 // of the virtual method rel.
1912 void Node::dump_related_compact() const {
1913 Compile* C = Compile::current();
1914 GrowableArray <Node *> in_rel(C->unique());
1915 GrowableArray <Node *> out_rel(C->unique());
1916 this->related(&in_rel, &out_rel, true);
1917 int n_in = in_rel.length();
1918 int n_out = out_rel.length();
1919
1920 this->dump_comp(n_in == 0 ? "\n" : " ");
1921 for (int i = 0; i < n_in; i++) {
1922 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1923 }
1924 for (int i = 0; i < n_out; i++) {
1925 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1926 }
1927 }
1928
1929 //------------------------------related----------------------------------------
1930 // Collect a Node's related nodes. The default behaviour just collects the
1931 // inputs and outputs at depth 1, including both control and data flow edges,
1932 // regardless of whether the presentation is compact or not. For data nodes,
1933 // the default is to collect all data inputs (till level 1 if compact), and
1934 // outputs till level 1.
1935 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1936 if (this->is_CFG()) {
1937 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1938 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1939 } else {
1940 if (compact) {
1941 this->collect_nodes(in_rel, 1, false, true);
1942 } else {
1943 this->collect_nodes_in_all_data(in_rel, false);
1944 }
1945 this->collect_nodes(out_rel, -1, false, false);
1946 }
1947 }
1948
1949 //---------------------------collect_nodes-------------------------------------
1950 // An entry point to the low-level node collection facility, to start from a
1951 // given node in the graph. The start node is by default not included in the
1952 // result.
1953 // Arguments:
1954 // ns: collect the nodes into this data structure.
1955 // d: the depth (distance from start node) to which nodes should be
1956 // collected. A value >0 indicates input nodes, a value <0, output
1957 // nodes.
1958 // ctrl: include only control nodes.
1959 // data: include only data nodes.
1960 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
1961 if (ctrl && data) {
1962 // ignore nonsensical combination
1963 return;
1964 }
1965 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
1966 }
1967
1968 //--------------------------collect_nodes_in-----------------------------------
1969 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
1970 // The maximum depth is determined using a BFS that visits all primary (data
1971 // or control) inputs and increments the depth at each level.
1972 uint d_in = 0;
1973 GrowableArray<Node*> nodes(Compile::current()->unique());
1974 nodes.push(start);
1975 int nodes_at_current_level = 1;
1976 int n_idx = 0;
1977 while (nodes_at_current_level > 0) {
1978 // Add all primary inputs reachable from the current level to the list, and
1979 // increase the depth if there were any.
1980 int nodes_at_next_level = 0;
1981 bool nodes_added = false;
1982 while (nodes_at_current_level > 0) {
1983 nodes_at_current_level--;
1984 Node* current = nodes.at(n_idx++);
1985 for (uint i = 0; i < current->len(); i++) {
1986 Node* n = current->in(i);
1987 if (NotANode(n)) {
1988 continue;
1989 }
1990 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
1991 continue;
1992 }
1993 if (!nodes.contains(n)) {
1994 nodes.push(n);
1995 nodes_added = true;
1996 nodes_at_next_level++;
1997 }
1998 }
1999 }
2000 if (nodes_added) {
2001 d_in++;
2002 }
2003 nodes_at_current_level = nodes_at_next_level;
2004 }
2005 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
2006 if (collect_secondary) {
2007 // Now, iterate over the secondary nodes in ns and add the respective
2008 // boundary reachable from them.
2009 GrowableArray<Node*> sns(Compile::current()->unique());
2010 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2011 Node* n = *it;
2012 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2013 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2014 ns->append_if_missing(*d);
2015 }
2016 sns.clear();
2017 }
2018 }
2019 }
2020
2021 //---------------------collect_nodes_in_all_data-------------------------------
2022 // Collect the entire data input graph. Include the control boundary if
2023 // requested.
2024 // Arguments:
2025 // ns: collect the nodes into this data structure.
2026 // ctrl: if true, include the control boundary.
2027 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2028 collect_nodes_in((Node*) this, ns, true, ctrl);
2029 }
2030
2031 //--------------------------collect_nodes_in_all_ctrl--------------------------
2032 // Collect the entire control input graph. Include the data boundary if
2033 // requested.
2034 // ns: collect the nodes into this data structure.
2035 // data: if true, include the control boundary.
2036 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2037 collect_nodes_in((Node*) this, ns, false, data);
2038 }
2039
2040 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2041 // Collect the entire output graph until hitting control node boundaries, and
2042 // include those.
2043 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2044 // Perform a BFS and stop at control nodes.
2045 GrowableArray<Node*> nodes(Compile::current()->unique());
2046 nodes.push((Node*) this);
2047 while (nodes.length() > 0) {
2048 Node* current = nodes.pop();
2049 if (NotANode(current)) {
2050 continue;
2051 }
2052 ns->append_if_missing(current);
2053 if (!current->is_CFG()) {
2054 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2055 nodes.push(current->out(i));
2056 }
2057 }
2058 }
2059 ns->remove((Node*) this);
2060 }
2061
2062 // VERIFICATION CODE
2063 // For each input edge to a node (ie - for each Use-Def edge), verify that
2064 // there is a corresponding Def-Use edge.
2065 //------------------------------verify_edges-----------------------------------
2066 void Node::verify_edges(Unique_Node_List &visited) {
2067 uint i, j, idx;
2068 int cnt;
2069 Node *n;
2070
2071 // Recursive termination test
2072 if (visited.member(this)) return;
2073 visited.push(this);
2074
2075 // Walk over all input edges, checking for correspondence
2076 for( i = 0; i < len(); i++ ) {
2077 n = in(i);
2078 if (n != NULL && !n->is_top()) {
2079 // Count instances of (Node *)this
2080 cnt = 0;
2081 for (idx = 0; idx < n->_outcnt; idx++ ) {
2082 if (n->_out[idx] == (Node *)this) cnt++;
2083 }
2084 assert( cnt > 0,"Failed to find Def-Use edge." );
2085 // Check for duplicate edges
2086 // walk the input array downcounting the input edges to n
2087 for( j = 0; j < len(); j++ ) {
2088 if( in(j) == n ) cnt--;
2089 }
2090 assert( cnt == 0,"Mismatched edge count.");
2091 } else if (n == NULL) {
2092 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
2093 } else {
2094 assert(n->is_top(), "sanity");
2095 // Nothing to check.
2096 }
2097 }
2098 // Recursive walk over all input edges
2099 for( i = 0; i < len(); i++ ) {
2100 n = in(i);
2101 if( n != NULL )
2102 in(i)->verify_edges(visited);
2103 }
2104 }
2105
2106 //------------------------------verify_recur-----------------------------------
2107 static const Node *unique_top = NULL;
2108
2109 void Node::verify_recur(const Node *n, int verify_depth,
2110 VectorSet &old_space, VectorSet &new_space) {
2111 if ( verify_depth == 0 ) return;
2112 if (verify_depth > 0) --verify_depth;
2113
2114 Compile* C = Compile::current();
2115
2116 // Contained in new_space or old_space?
2117 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2118 // Check for visited in the proper space. Numberings are not unique
2119 // across spaces so we need a separate VectorSet for each space.
2120 if( v->test_set(n->_idx) ) return;
2121
2122 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2123 if (C->cached_top_node() == NULL)
2124 C->set_cached_top_node((Node*)n);
2125 assert(C->cached_top_node() == n, "TOP node must be unique");
2126 }
2127
2128 for( uint i = 0; i < n->len(); i++ ) {
2129 Node *x = n->in(i);
2130 if (!x || x->is_top()) continue;
2131
2132 // Verify my input has a def-use edge to me
2133 if (true /*VerifyDefUse*/) {
2134 // Count use-def edges from n to x
2135 int cnt = 0;
2136 for( uint j = 0; j < n->len(); j++ )
2137 if( n->in(j) == x )
2138 cnt++;
2139 // Count def-use edges from x to n
2140 uint max = x->_outcnt;
2141 for( uint k = 0; k < max; k++ )
2142 if (x->_out[k] == n)
2143 cnt--;
2144 assert( cnt == 0, "mismatched def-use edge counts" );
2145 }
2146
2147 verify_recur(x, verify_depth, old_space, new_space);
2148 }
2149
2150 }
2151
2152 //------------------------------verify-----------------------------------------
2153 // Check Def-Use info for my subgraph
2154 void Node::verify() const {
2155 Compile* C = Compile::current();
2156 Node* old_top = C->cached_top_node();
2157 ResourceMark rm;
2158 ResourceArea *area = Thread::current()->resource_area();
2159 VectorSet old_space(area), new_space(area);
2160 verify_recur(this, -1, old_space, new_space);
2161 C->set_cached_top_node(old_top);
2162 }
2163 #endif
2164
2165
2166 //------------------------------walk-------------------------------------------
2167 // Graph walk, with both pre-order and post-order functions
2168 void Node::walk(NFunc pre, NFunc post, void *env) {
2169 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2170 walk_(pre, post, env, visited);
2171 }
2172
2173 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2174 if( visited.test_set(_idx) ) return;
2175 pre(*this,env); // Call the pre-order walk function
2176 for( uint i=0; i<_max; i++ )
2177 if( in(i) ) // Input exists and is not walked?
2178 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2179 post(*this,env); // Call the post-order walk function
2180 }
2181
2182 void Node::nop(Node &, void*) {}
2183
2184 //------------------------------Registers--------------------------------------
2185 // Do we Match on this edge index or not? Generally false for Control
2186 // and true for everything else. Weird for calls & returns.
2187 uint Node::match_edge(uint idx) const {
2188 return idx; // True for other than index 0 (control)
2189 }
2190
2191 static RegMask _not_used_at_all;
2192 // Register classes are defined for specific machines
2193 const RegMask &Node::out_RegMask() const {
2194 ShouldNotCallThis();
2195 return _not_used_at_all;
2196 }
2197
2198 const RegMask &Node::in_RegMask(uint) const {
2199 ShouldNotCallThis();
2200 return _not_used_at_all;
2201 }
2202
2203 //=============================================================================
2204 //-----------------------------------------------------------------------------
2205 void Node_Array::reset( Arena *new_arena ) {
2206 _a->Afree(_nodes,_max*sizeof(Node*));
2207 _max = 0;
2208 _nodes = NULL;
2209 _a = new_arena;
2210 }
2211
2212 //------------------------------clear------------------------------------------
2213 // Clear all entries in _nodes to NULL but keep storage
2214 void Node_Array::clear() {
2215 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2216 }
2217
2218 //-----------------------------------------------------------------------------
2219 void Node_Array::grow( uint i ) {
2220 if( !_max ) {
2221 _max = 1;
2222 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2223 _nodes[0] = NULL;
2224 }
2225 uint old = _max;
2226 while( i >= _max ) _max <<= 1; // Double to fit
2227 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2228 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2229 }
2230
2231 //-----------------------------------------------------------------------------
2232 void Node_Array::insert( uint i, Node *n ) {
2233 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2234 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2235 _nodes[i] = n;
2236 }
2237
2238 //-----------------------------------------------------------------------------
2239 void Node_Array::remove( uint i ) {
2240 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2241 _nodes[_max-1] = NULL;
2242 }
2243
2244 //-----------------------------------------------------------------------------
2245 void Node_Array::sort( C_sort_func_t func) {
2246 qsort( _nodes, _max, sizeof( Node* ), func );
2247 }
2248
2249 //-----------------------------------------------------------------------------
2250 void Node_Array::dump() const {
2251 #ifndef PRODUCT
2252 for( uint i = 0; i < _max; i++ ) {
2253 Node *nn = _nodes[i];
2254 if( nn != NULL ) {
2255 tty->print("%5d--> ",i); nn->dump();
2256 }
2257 }
2258 #endif
2259 }
2260
2261 //--------------------------is_iteratively_computed------------------------------
2262 // Operation appears to be iteratively computed (such as an induction variable)
2263 // It is possible for this operation to return false for a loop-varying
2264 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2265 bool Node::is_iteratively_computed() {
2266 if (ideal_reg()) { // does operation have a result register?
2267 for (uint i = 1; i < req(); i++) {
2268 Node* n = in(i);
2269 if (n != NULL && n->is_Phi()) {
2270 for (uint j = 1; j < n->req(); j++) {
2271 if (n->in(j) == this) {
2272 return true;
2273 }
2274 }
2275 }
2276 }
2277 }
2278 return false;
2279 }
2280
2281 //--------------------------find_similar------------------------------
2282 // Return a node with opcode "opc" and same inputs as "this" if one can
2283 // be found; Otherwise return NULL;
2284 Node* Node::find_similar(int opc) {
2285 if (req() >= 2) {
2286 Node* def = in(1);
2287 if (def && def->outcnt() >= 2) {
2288 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2289 Node* use = def->fast_out(i);
2290 if (use != this &&
2291 use->Opcode() == opc &&
2292 use->req() == req()) {
2293 uint j;
2294 for (j = 0; j < use->req(); j++) {
2295 if (use->in(j) != in(j)) {
2296 break;
2297 }
2298 }
2299 if (j == use->req()) {
2300 return use;
2301 }
2302 }
2303 }
2304 }
2305 }
2306 return NULL;
2307 }
2308
2309
2310 //--------------------------unique_ctrl_out------------------------------
2311 // Return the unique control out if only one. Null if none or more than one.
2312 Node* Node::unique_ctrl_out() const {
2313 Node* found = NULL;
2314 for (uint i = 0; i < outcnt(); i++) {
2315 Node* use = raw_out(i);
2316 if (use->is_CFG() && use != this) {
2317 if (found != NULL) return NULL;
2318 found = use;
2319 }
2320 }
2321 return found;
2322 }
2323
2324 void Node::ensure_control_or_add_prec(Node* c) {
2325 if (in(0) == NULL) {
2326 set_req(0, c);
2327 } else if (in(0) != c) {
2328 add_prec(c);
2329 }
2330 }
2331
2332 //=============================================================================
2333 //------------------------------yank-------------------------------------------
2334 // Find and remove
2335 void Node_List::yank( Node *n ) {
2336 uint i;
2337 for( i = 0; i < _cnt; i++ )
2338 if( _nodes[i] == n )
2339 break;
2340
2341 if( i < _cnt )
2342 _nodes[i] = _nodes[--_cnt];
2343 }
2344
2345 //------------------------------dump-------------------------------------------
2346 void Node_List::dump() const {
2347 #ifndef PRODUCT
2348 for( uint i = 0; i < _cnt; i++ )
2349 if( _nodes[i] ) {
2350 tty->print("%5d--> ",i);
2351 _nodes[i]->dump();
2352 }
2353 #endif
2354 }
2355
2356 void Node_List::dump_simple() const {
2357 #ifndef PRODUCT
2358 for( uint i = 0; i < _cnt; i++ )
2359 if( _nodes[i] ) {
2360 tty->print(" %d", _nodes[i]->_idx);
2361 } else {
2362 tty->print(" NULL");
2363 }
2364 #endif
2365 }
2366
2367 //=============================================================================
2368 //------------------------------remove-----------------------------------------
2369 void Unique_Node_List::remove( Node *n ) {
2370 if( _in_worklist[n->_idx] ) {
2371 for( uint i = 0; i < size(); i++ )
2372 if( _nodes[i] == n ) {
2373 map(i,Node_List::pop());
2374 _in_worklist >>= n->_idx;
2375 return;
2376 }
2377 ShouldNotReachHere();
2378 }
2379 }
2380
2381 //-----------------------remove_useless_nodes----------------------------------
2382 // Remove useless nodes from worklist
2383 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2384
2385 for( uint i = 0; i < size(); ++i ) {
2386 Node *n = at(i);
2387 assert( n != NULL, "Did not expect null entries in worklist");
2388 if( ! useful.test(n->_idx) ) {
2389 _in_worklist >>= n->_idx;
2390 map(i,Node_List::pop());
2391 // Node *replacement = Node_List::pop();
2392 // if( i != size() ) { // Check if removing last entry
2393 // _nodes[i] = replacement;
2394 // }
2395 --i; // Visit popped node
2396 // If it was last entry, loop terminates since size() was also reduced
2397 }
2398 }
2399 }
2400
2401 //=============================================================================
2402 void Node_Stack::grow() {
2403 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2404 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2405 size_t max = old_max << 1; // max * 2
2406 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2407 _inode_max = _inodes + max;
2408 _inode_top = _inodes + old_top; // restore _top
2409 }
2410
2411 // Node_Stack is used to map nodes.
2412 Node* Node_Stack::find(uint idx) const {
2413 uint sz = size();
2414 for (uint i=0; i < sz; i++) {
2415 if (idx == index_at(i) )
2416 return node_at(i);
2417 }
2418 return NULL;
2419 }
2420
2421 //=============================================================================
2422 uint TypeNode::size_of() const { return sizeof(*this); }
2423 #ifndef PRODUCT
2424 void TypeNode::dump_spec(outputStream *st) const {
2425 if( !Verbose && !WizardMode ) {
2426 // standard dump does this in Verbose and WizardMode
2427 st->print(" #"); _type->dump_on(st);
2428 }
2429 }
2430
2431 void TypeNode::dump_compact_spec(outputStream *st) const {
2432 st->print("#");
2433 _type->dump_on(st);
2434 }
2435 #endif
2436 uint TypeNode::hash() const {
2437 return Node::hash() + _type->hash();
2438 }
2439 uint TypeNode::cmp( const Node &n ) const
2440 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2441 const Type *TypeNode::bottom_type() const { return _type; }
2442 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
2443
2444 //------------------------------ideal_reg--------------------------------------
2445 uint TypeNode::ideal_reg() const {
2446 return _type->ideal_reg();
2447 }