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