1 /*
2 * Copyright (c) 1997, 2015, 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 // Find out of current node that matches opcode.
885 Node* Node::find_out_with(int opcode) {
886 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
887 Node* use = fast_out(i);
888 if (use->Opcode() == opcode) {
889 return use;
890 }
891 }
892 return NULL;
893 }
894
895 // Return true if the current node has an out that matches opcode.
896 bool Node::has_out_with(int opcode) {
897 return (find_out_with(opcode) != NULL);
898 }
899
900 // Return true if the current node has an out that matches any of the opcodes.
901 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
902 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
903 int opcode = fast_out(i)->Opcode();
904 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
905 return true;
906 }
907 }
908 return false;
909 }
910
911
912 //---------------------------uncast_helper-------------------------------------
913 Node* Node::uncast_helper(const Node* p) {
914 #ifdef ASSERT
915 uint depth_count = 0;
916 const Node* orig_p = p;
917 #endif
918
919 while (true) {
920 #ifdef ASSERT
921 if (depth_count >= K) {
922 orig_p->dump(4);
923 if (p != orig_p)
924 p->dump(1);
925 }
926 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
927 #endif
928 if (p == NULL || p->req() != 2) {
929 break;
930 } else if (p->is_ConstraintCast()) {
931 p = p->in(1);
932 } else if (p->is_CheckCastPP()) {
933 p = p->in(1);
934 } else {
935 break;
936 }
937 }
938 return (Node*) p;
939 }
940
941 //------------------------------add_prec---------------------------------------
942 // Add a new precedence input. Precedence inputs are unordered, with
943 // duplicates removed and NULLs packed down at the end.
944 void Node::add_prec( Node *n ) {
945 assert( is_not_dead(n), "can not use dead node");
946
947 // Check for NULL at end
948 if( _cnt >= _max || in(_max-1) )
949 grow( _max+1 );
950
951 // Find a precedence edge to move
952 uint i = _cnt;
953 while( in(i) != NULL ) i++;
954 _in[i] = n; // Stuff prec edge over NULL
955 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
956 }
957
958 //------------------------------rm_prec----------------------------------------
959 // Remove a precedence input. Precedence inputs are unordered, with
960 // duplicates removed and NULLs packed down at the end.
961 void Node::rm_prec( uint j ) {
962
963 // Find end of precedence list to pack NULLs
964 uint i;
965 for( i=j; i<_max; i++ )
966 if( !_in[i] ) // Find the NULL at end of prec edge list
967 break;
968 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
969 _in[j] = _in[--i]; // Move last element over removed guy
970 _in[i] = NULL; // NULL out last element
971 }
972
973 //------------------------------size_of----------------------------------------
974 uint Node::size_of() const { return sizeof(*this); }
975
976 //------------------------------ideal_reg--------------------------------------
977 uint Node::ideal_reg() const { return 0; }
978
979 //------------------------------jvms-------------------------------------------
980 JVMState* Node::jvms() const { return NULL; }
981
982 #ifdef ASSERT
983 //------------------------------jvms-------------------------------------------
984 bool Node::verify_jvms(const JVMState* using_jvms) const {
985 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
986 if (jvms == using_jvms) return true;
987 }
988 return false;
989 }
990
991 //------------------------------init_NodeProperty------------------------------
992 void Node::init_NodeProperty() {
993 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
994 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
995 }
996 #endif
997
998 //------------------------------format-----------------------------------------
999 // Print as assembly
1000 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1001 //------------------------------emit-------------------------------------------
1002 // Emit bytes starting at parameter 'ptr'.
1003 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1004 //------------------------------size-------------------------------------------
1005 // Size of instruction in bytes
1006 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1007
1008 //------------------------------CFG Construction-------------------------------
1009 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1010 // Goto and Return.
1011 const Node *Node::is_block_proj() const { return 0; }
1012
1013 // Minimum guaranteed type
1014 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1015
1016
1017 //------------------------------raise_bottom_type------------------------------
1018 // Get the worst-case Type output for this Node.
1019 void Node::raise_bottom_type(const Type* new_type) {
1020 if (is_Type()) {
1021 TypeNode *n = this->as_Type();
1022 if (VerifyAliases) {
1023 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1024 }
1025 n->set_type(new_type);
1026 } else if (is_Load()) {
1027 LoadNode *n = this->as_Load();
1028 if (VerifyAliases) {
1029 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1030 }
1031 n->set_type(new_type);
1032 }
1033 }
1034
1035 //------------------------------Identity---------------------------------------
1036 // Return a node that the given node is equivalent to.
1037 Node *Node::Identity( PhaseTransform * ) {
1038 return this; // Default to no identities
1039 }
1040
1041 //------------------------------Value------------------------------------------
1042 // Compute a new Type for a node using the Type of the inputs.
1043 const Type *Node::Value( PhaseTransform * ) const {
1044 return bottom_type(); // Default to worst-case Type
1045 }
1046
1047 //------------------------------Ideal------------------------------------------
1048 //
1049 // 'Idealize' the graph rooted at this Node.
1050 //
1051 // In order to be efficient and flexible there are some subtle invariants
1052 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1053 // these invariants, although its too slow to have on by default. If you are
1054 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1055 //
1056 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1057 // pointer. If ANY change is made, it must return the root of the reshaped
1058 // graph - even if the root is the same Node. Example: swapping the inputs
1059 // to an AddINode gives the same answer and same root, but you still have to
1060 // return the 'this' pointer instead of NULL.
1061 //
1062 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1063 // Identity call to return an old Node; basically if Identity can find
1064 // another Node have the Ideal call make no change and return NULL.
1065 // Example: AddINode::Ideal must check for add of zero; in this case it
1066 // returns NULL instead of doing any graph reshaping.
1067 //
1068 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1069 // sharing there may be other users of the old Nodes relying on their current
1070 // semantics. Modifying them will break the other users.
1071 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1072 // "X+3" unchanged in case it is shared.
1073 //
1074 // If you modify the 'this' pointer's inputs, you should use
1075 // 'set_req'. If you are making a new Node (either as the new root or
1076 // some new internal piece) you may use 'init_req' to set the initial
1077 // value. You can make a new Node with either 'new' or 'clone'. In
1078 // either case, def-use info is correctly maintained.
1079 //
1080 // Example: reshape "(X+3)+4" into "X+7":
1081 // set_req(1, in(1)->in(1));
1082 // set_req(2, phase->intcon(7));
1083 // return this;
1084 // Example: reshape "X*4" into "X<<2"
1085 // return new LShiftINode(in(1), phase->intcon(2));
1086 //
1087 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1088 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1089 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1090 // return new AddINode(shift, in(1));
1091 //
1092 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1093 // These forms are faster than 'phase->transform(new ConNode())' and Do
1094 // The Right Thing with def-use info.
1095 //
1096 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1097 // graph uses the 'this' Node it must be the root. If you want a Node with
1098 // the same Opcode as the 'this' pointer use 'clone'.
1099 //
1100 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1101 return NULL; // Default to being Ideal already
1102 }
1103
1104 // Some nodes have specific Ideal subgraph transformations only if they are
1105 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1106 // for the transformations to happen.
1107 bool Node::has_special_unique_user() const {
1108 assert(outcnt() == 1, "match only for unique out");
1109 Node* n = unique_out();
1110 int op = Opcode();
1111 if (this->is_Store()) {
1112 // Condition for back-to-back stores folding.
1113 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1114 } else if (this->is_Load()) {
1115 // Condition for removing an unused LoadNode from the MemBarAcquire precedence input
1116 return n->Opcode() == Op_MemBarAcquire;
1117 } else if (op == Op_AddL) {
1118 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1119 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1120 } else if (op == Op_SubI || op == Op_SubL) {
1121 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1122 return n->Opcode() == op && n->in(2) == this;
1123 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1124 // See IfProjNode::Identity()
1125 return true;
1126 }
1127 return false;
1128 };
1129
1130 //--------------------------find_exact_control---------------------------------
1131 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1132 Node* Node::find_exact_control(Node* ctrl) {
1133 if (ctrl == NULL && this->is_Region())
1134 ctrl = this->as_Region()->is_copy();
1135
1136 if (ctrl != NULL && ctrl->is_CatchProj()) {
1137 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1138 ctrl = ctrl->in(0);
1139 if (ctrl != NULL && !ctrl->is_top())
1140 ctrl = ctrl->in(0);
1141 }
1142
1143 if (ctrl != NULL && ctrl->is_Proj())
1144 ctrl = ctrl->in(0);
1145
1146 return ctrl;
1147 }
1148
1149 //--------------------------dominates------------------------------------------
1150 // Helper function for MemNode::all_controls_dominate().
1151 // Check if 'this' control node dominates or equal to 'sub' control node.
1152 // We already know that if any path back to Root or Start reaches 'this',
1153 // then all paths so, so this is a simple search for one example,
1154 // not an exhaustive search for a counterexample.
1155 bool Node::dominates(Node* sub, Node_List &nlist) {
1156 assert(this->is_CFG(), "expecting control");
1157 assert(sub != NULL && sub->is_CFG(), "expecting control");
1158
1159 // detect dead cycle without regions
1160 int iterations_without_region_limit = DominatorSearchLimit;
1161
1162 Node* orig_sub = sub;
1163 Node* dom = this;
1164 bool met_dom = false;
1165 nlist.clear();
1166
1167 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1168 // After seeing 'dom', continue up to Root or Start.
1169 // If we hit a region (backward split point), it may be a loop head.
1170 // Keep going through one of the region's inputs. If we reach the
1171 // same region again, go through a different input. Eventually we
1172 // will either exit through the loop head, or give up.
1173 // (If we get confused, break out and return a conservative 'false'.)
1174 while (sub != NULL) {
1175 if (sub->is_top()) break; // Conservative answer for dead code.
1176 if (sub == dom) {
1177 if (nlist.size() == 0) {
1178 // No Region nodes except loops were visited before and the EntryControl
1179 // path was taken for loops: it did not walk in a cycle.
1180 return true;
1181 } else if (met_dom) {
1182 break; // already met before: walk in a cycle
1183 } else {
1184 // Region nodes were visited. Continue walk up to Start or Root
1185 // to make sure that it did not walk in a cycle.
1186 met_dom = true; // first time meet
1187 iterations_without_region_limit = DominatorSearchLimit; // Reset
1188 }
1189 }
1190 if (sub->is_Start() || sub->is_Root()) {
1191 // Success if we met 'dom' along a path to Start or Root.
1192 // We assume there are no alternative paths that avoid 'dom'.
1193 // (This assumption is up to the caller to ensure!)
1194 return met_dom;
1195 }
1196 Node* up = sub->in(0);
1197 // Normalize simple pass-through regions and projections:
1198 up = sub->find_exact_control(up);
1199 // If sub == up, we found a self-loop. Try to push past it.
1200 if (sub == up && sub->is_Loop()) {
1201 // Take loop entry path on the way up to 'dom'.
1202 up = sub->in(1); // in(LoopNode::EntryControl);
1203 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1204 // Always take in(1) path on the way up to 'dom' for clone regions
1205 // (with only one input) or regions which merge > 2 paths
1206 // (usually used to merge fast/slow paths).
1207 up = sub->in(1);
1208 } else if (sub == up && sub->is_Region()) {
1209 // Try both paths for Regions with 2 input paths (it may be a loop head).
1210 // It could give conservative 'false' answer without information
1211 // which region's input is the entry path.
1212 iterations_without_region_limit = DominatorSearchLimit; // Reset
1213
1214 bool region_was_visited_before = false;
1215 // Was this Region node visited before?
1216 // If so, we have reached it because we accidentally took a
1217 // loop-back edge from 'sub' back into the body of the loop,
1218 // and worked our way up again to the loop header 'sub'.
1219 // So, take the first unexplored path on the way up to 'dom'.
1220 for (int j = nlist.size() - 1; j >= 0; j--) {
1221 intptr_t ni = (intptr_t)nlist.at(j);
1222 Node* visited = (Node*)(ni & ~1);
1223 bool visited_twice_already = ((ni & 1) != 0);
1224 if (visited == sub) {
1225 if (visited_twice_already) {
1226 // Visited 2 paths, but still stuck in loop body. Give up.
1227 return false;
1228 }
1229 // The Region node was visited before only once.
1230 // (We will repush with the low bit set, below.)
1231 nlist.remove(j);
1232 // We will find a new edge and re-insert.
1233 region_was_visited_before = true;
1234 break;
1235 }
1236 }
1237
1238 // Find an incoming edge which has not been seen yet; walk through it.
1239 assert(up == sub, "");
1240 uint skip = region_was_visited_before ? 1 : 0;
1241 for (uint i = 1; i < sub->req(); i++) {
1242 Node* in = sub->in(i);
1243 if (in != NULL && !in->is_top() && in != sub) {
1244 if (skip == 0) {
1245 up = in;
1246 break;
1247 }
1248 --skip; // skip this nontrivial input
1249 }
1250 }
1251
1252 // Set 0 bit to indicate that both paths were taken.
1253 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1254 }
1255
1256 if (up == sub) {
1257 break; // some kind of tight cycle
1258 }
1259 if (up == orig_sub && met_dom) {
1260 // returned back after visiting 'dom'
1261 break; // some kind of cycle
1262 }
1263 if (--iterations_without_region_limit < 0) {
1264 break; // dead cycle
1265 }
1266 sub = up;
1267 }
1268
1269 // Did not meet Root or Start node in pred. chain.
1270 // Conservative answer for dead code.
1271 return false;
1272 }
1273
1274 //------------------------------remove_dead_region-----------------------------
1275 // This control node is dead. Follow the subgraph below it making everything
1276 // using it dead as well. This will happen normally via the usual IterGVN
1277 // worklist but this call is more efficient. Do not update use-def info
1278 // inside the dead region, just at the borders.
1279 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1280 // Con's are a popular node to re-hit in the hash table again.
1281 if( dead->is_Con() ) return;
1282
1283 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1284 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1285 Node_List nstack(Thread::current()->resource_area());
1286
1287 Node *top = igvn->C->top();
1288 nstack.push(dead);
1289 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1290
1291 while (nstack.size() > 0) {
1292 dead = nstack.pop();
1293 if (dead->outcnt() > 0) {
1294 // Keep dead node on stack until all uses are processed.
1295 nstack.push(dead);
1296 // For all Users of the Dead... ;-)
1297 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1298 Node* use = dead->last_out(k);
1299 igvn->hash_delete(use); // Yank from hash table prior to mod
1300 if (use->in(0) == dead) { // Found another dead node
1301 assert (!use->is_Con(), "Control for Con node should be Root node.");
1302 use->set_req(0, top); // Cut dead edge to prevent processing
1303 nstack.push(use); // the dead node again.
1304 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1305 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1306 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1307 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1308 use->set_req(0, top); // Cut self edge
1309 nstack.push(use);
1310 } else { // Else found a not-dead user
1311 // Dead if all inputs are top or null
1312 bool dead_use = !use->is_Root(); // Keep empty graph alive
1313 for (uint j = 1; j < use->req(); j++) {
1314 Node* in = use->in(j);
1315 if (in == dead) { // Turn all dead inputs into TOP
1316 use->set_req(j, top);
1317 } else if (in != NULL && !in->is_top()) {
1318 dead_use = false;
1319 }
1320 }
1321 if (dead_use) {
1322 if (use->is_Region()) {
1323 use->set_req(0, top); // Cut self edge
1324 }
1325 nstack.push(use);
1326 } else {
1327 igvn->_worklist.push(use);
1328 }
1329 }
1330 // Refresh the iterator, since any number of kills might have happened.
1331 k = dead->last_outs(kmin);
1332 }
1333 } else { // (dead->outcnt() == 0)
1334 // Done with outputs.
1335 igvn->hash_delete(dead);
1336 igvn->_worklist.remove(dead);
1337 igvn->C->remove_modified_node(dead);
1338 igvn->set_type(dead, Type::TOP);
1339 if (dead->is_macro()) {
1340 igvn->C->remove_macro_node(dead);
1341 }
1342 if (dead->is_expensive()) {
1343 igvn->C->remove_expensive_node(dead);
1344 }
1345 igvn->C->record_dead_node(dead->_idx);
1346 // Kill all inputs to the dead guy
1347 for (uint i=0; i < dead->req(); i++) {
1348 Node *n = dead->in(i); // Get input to dead guy
1349 if (n != NULL && !n->is_top()) { // Input is valid?
1350 dead->set_req(i, top); // Smash input away
1351 if (n->outcnt() == 0) { // Input also goes dead?
1352 if (!n->is_Con())
1353 nstack.push(n); // Clear it out as well
1354 } else if (n->outcnt() == 1 &&
1355 n->has_special_unique_user()) {
1356 igvn->add_users_to_worklist( n );
1357 } else if (n->outcnt() <= 2 && n->is_Store()) {
1358 // Push store's uses on worklist to enable folding optimization for
1359 // store/store and store/load to the same address.
1360 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1361 // and remove_globally_dead_node().
1362 igvn->add_users_to_worklist( n );
1363 }
1364 }
1365 }
1366 } // (dead->outcnt() == 0)
1367 } // while (nstack.size() > 0) for outputs
1368 return;
1369 }
1370
1371 //------------------------------remove_dead_region-----------------------------
1372 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1373 Node *n = in(0);
1374 if( !n ) return false;
1375 // Lost control into this guy? I.e., it became unreachable?
1376 // Aggressively kill all unreachable code.
1377 if (can_reshape && n->is_top()) {
1378 kill_dead_code(this, phase->is_IterGVN());
1379 return false; // Node is dead.
1380 }
1381
1382 if( n->is_Region() && n->as_Region()->is_copy() ) {
1383 Node *m = n->nonnull_req();
1384 set_req(0, m);
1385 return true;
1386 }
1387 return false;
1388 }
1389
1390 //------------------------------hash-------------------------------------------
1391 // Hash function over Nodes.
1392 uint Node::hash() const {
1393 uint sum = 0;
1394 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1395 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1396 return (sum>>2) + _cnt + Opcode();
1397 }
1398
1399 //------------------------------cmp--------------------------------------------
1400 // Compare special parts of simple Nodes
1401 uint Node::cmp( const Node &n ) const {
1402 return 1; // Must be same
1403 }
1404
1405 //------------------------------rematerialize-----------------------------------
1406 // Should we clone rather than spill this instruction?
1407 bool Node::rematerialize() const {
1408 if ( is_Mach() )
1409 return this->as_Mach()->rematerialize();
1410 else
1411 return (_flags & Flag_rematerialize) != 0;
1412 }
1413
1414 //------------------------------needs_anti_dependence_check---------------------
1415 // Nodes which use memory without consuming it, hence need antidependences.
1416 bool Node::needs_anti_dependence_check() const {
1417 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1418 return false;
1419 else
1420 return in(1)->bottom_type()->has_memory();
1421 }
1422
1423
1424 // Get an integer constant from a ConNode (or CastIINode).
1425 // Return a default value if there is no apparent constant here.
1426 const TypeInt* Node::find_int_type() const {
1427 if (this->is_Type()) {
1428 return this->as_Type()->type()->isa_int();
1429 } else if (this->is_Con()) {
1430 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1431 return this->bottom_type()->isa_int();
1432 }
1433 return NULL;
1434 }
1435
1436 // Get a pointer constant from a ConstNode.
1437 // Returns the constant if it is a pointer ConstNode
1438 intptr_t Node::get_ptr() const {
1439 assert( Opcode() == Op_ConP, "" );
1440 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1441 }
1442
1443 // Get a narrow oop constant from a ConNNode.
1444 intptr_t Node::get_narrowcon() const {
1445 assert( Opcode() == Op_ConN, "" );
1446 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1447 }
1448
1449 // Get a long constant from a ConNode.
1450 // Return a default value if there is no apparent constant here.
1451 const TypeLong* Node::find_long_type() const {
1452 if (this->is_Type()) {
1453 return this->as_Type()->type()->isa_long();
1454 } else if (this->is_Con()) {
1455 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1456 return this->bottom_type()->isa_long();
1457 }
1458 return NULL;
1459 }
1460
1461
1462 /**
1463 * Return a ptr type for nodes which should have it.
1464 */
1465 const TypePtr* Node::get_ptr_type() const {
1466 const TypePtr* tp = this->bottom_type()->make_ptr();
1467 #ifdef ASSERT
1468 if (tp == NULL) {
1469 this->dump(1);
1470 assert((tp != NULL), "unexpected node type");
1471 }
1472 #endif
1473 return tp;
1474 }
1475
1476 // Get a double constant from a ConstNode.
1477 // Returns the constant if it is a double ConstNode
1478 jdouble Node::getd() const {
1479 assert( Opcode() == Op_ConD, "" );
1480 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1481 }
1482
1483 // Get a float constant from a ConstNode.
1484 // Returns the constant if it is a float ConstNode
1485 jfloat Node::getf() const {
1486 assert( Opcode() == Op_ConF, "" );
1487 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1488 }
1489
1490 #ifndef PRODUCT
1491
1492 //------------------------------find------------------------------------------
1493 // Find a neighbor of this Node with the given _idx
1494 // If idx is negative, find its absolute value, following both _in and _out.
1495 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1496 VectorSet* old_space, VectorSet* new_space ) {
1497 int node_idx = (idx >= 0) ? idx : -idx;
1498 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1499 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1500 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1501 if( v->test(n->_idx) ) return;
1502 if( (int)n->_idx == node_idx
1503 debug_only(|| n->debug_idx() == node_idx) ) {
1504 if (result != NULL)
1505 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1506 (uintptr_t)result, (uintptr_t)n, node_idx);
1507 result = n;
1508 }
1509 v->set(n->_idx);
1510 for( uint i=0; i<n->len(); i++ ) {
1511 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1512 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1513 }
1514 // Search along forward edges also:
1515 if (idx < 0 && !only_ctrl) {
1516 for( uint j=0; j<n->outcnt(); j++ ) {
1517 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1518 }
1519 }
1520 #ifdef ASSERT
1521 // Search along debug_orig edges last, checking for cycles
1522 Node* orig = n->debug_orig();
1523 if (orig != NULL) {
1524 do {
1525 if (NotANode(orig)) break;
1526 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1527 orig = orig->debug_orig();
1528 } while (orig != NULL && orig != n->debug_orig());
1529 }
1530 #endif //ASSERT
1531 }
1532
1533 // call this from debugger:
1534 Node* find_node(Node* n, int idx) {
1535 return n->find(idx);
1536 }
1537
1538 //------------------------------find-------------------------------------------
1539 Node* Node::find(int idx) const {
1540 ResourceArea *area = Thread::current()->resource_area();
1541 VectorSet old_space(area), new_space(area);
1542 Node* result = NULL;
1543 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1544 return result;
1545 }
1546
1547 //------------------------------find_ctrl--------------------------------------
1548 // Find an ancestor to this node in the control history with given _idx
1549 Node* Node::find_ctrl(int idx) const {
1550 ResourceArea *area = Thread::current()->resource_area();
1551 VectorSet old_space(area), new_space(area);
1552 Node* result = NULL;
1553 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1554 return result;
1555 }
1556 #endif
1557
1558
1559
1560 #ifndef PRODUCT
1561
1562 // -----------------------------Name-------------------------------------------
1563 extern const char *NodeClassNames[];
1564 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1565
1566 static bool is_disconnected(const Node* n) {
1567 for (uint i = 0; i < n->req(); i++) {
1568 if (n->in(i) != NULL) return false;
1569 }
1570 return true;
1571 }
1572
1573 #ifdef ASSERT
1574 static void dump_orig(Node* orig, outputStream *st) {
1575 Compile* C = Compile::current();
1576 if (NotANode(orig)) orig = NULL;
1577 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1578 if (orig == NULL) return;
1579 st->print(" !orig=");
1580 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1581 if (NotANode(fast)) fast = NULL;
1582 while (orig != NULL) {
1583 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1584 if (discon) st->print("[");
1585 if (!Compile::current()->node_arena()->contains(orig))
1586 st->print("o");
1587 st->print("%d", orig->_idx);
1588 if (discon) st->print("]");
1589 orig = orig->debug_orig();
1590 if (NotANode(orig)) orig = NULL;
1591 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1592 if (orig != NULL) st->print(",");
1593 if (fast != NULL) {
1594 // Step fast twice for each single step of orig:
1595 fast = fast->debug_orig();
1596 if (NotANode(fast)) fast = NULL;
1597 if (fast != NULL && fast != orig) {
1598 fast = fast->debug_orig();
1599 if (NotANode(fast)) fast = NULL;
1600 }
1601 if (fast == orig) {
1602 st->print("...");
1603 break;
1604 }
1605 }
1606 }
1607 }
1608
1609 void Node::set_debug_orig(Node* orig) {
1610 _debug_orig = orig;
1611 if (BreakAtNode == 0) return;
1612 if (NotANode(orig)) orig = NULL;
1613 int trip = 10;
1614 while (orig != NULL) {
1615 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1616 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1617 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1618 BREAKPOINT;
1619 }
1620 orig = orig->debug_orig();
1621 if (NotANode(orig)) orig = NULL;
1622 if (trip-- <= 0) break;
1623 }
1624 }
1625 #endif //ASSERT
1626
1627 //------------------------------dump------------------------------------------
1628 // Dump a Node
1629 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1630 Compile* C = Compile::current();
1631 bool is_new = C->node_arena()->contains(this);
1632 C->_in_dump_cnt++;
1633 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1634
1635 // Dump the required and precedence inputs
1636 dump_req(st);
1637 dump_prec(st);
1638 // Dump the outputs
1639 dump_out(st);
1640
1641 if (is_disconnected(this)) {
1642 #ifdef ASSERT
1643 st->print(" [%d]",debug_idx());
1644 dump_orig(debug_orig(), st);
1645 #endif
1646 st->cr();
1647 C->_in_dump_cnt--;
1648 return; // don't process dead nodes
1649 }
1650
1651 if (C->clone_map().value(_idx) != 0) {
1652 C->clone_map().dump(_idx);
1653 }
1654 // Dump node-specific info
1655 dump_spec(st);
1656 #ifdef ASSERT
1657 // Dump the non-reset _debug_idx
1658 if (Verbose && WizardMode) {
1659 st->print(" [%d]",debug_idx());
1660 }
1661 #endif
1662
1663 const Type *t = bottom_type();
1664
1665 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1666 const TypeInstPtr *toop = t->isa_instptr();
1667 const TypeKlassPtr *tkls = t->isa_klassptr();
1668 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1669 if (klass && klass->is_loaded() && klass->is_interface()) {
1670 st->print(" Interface:");
1671 } else if (toop) {
1672 st->print(" Oop:");
1673 } else if (tkls) {
1674 st->print(" Klass:");
1675 }
1676 t->dump_on(st);
1677 } else if (t == Type::MEMORY) {
1678 st->print(" Memory:");
1679 MemNode::dump_adr_type(this, adr_type(), st);
1680 } else if (Verbose || WizardMode) {
1681 st->print(" Type:");
1682 if (t) {
1683 t->dump_on(st);
1684 } else {
1685 st->print("no type");
1686 }
1687 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1688 // Dump MachSpillcopy vector type.
1689 t->dump_on(st);
1690 }
1691 if (is_new) {
1692 debug_only(dump_orig(debug_orig(), st));
1693 Node_Notes* nn = C->node_notes_at(_idx);
1694 if (nn != NULL && !nn->is_clear()) {
1695 if (nn->jvms() != NULL) {
1696 st->print(" !jvms:");
1697 nn->jvms()->dump_spec(st);
1698 }
1699 }
1700 }
1701 if (suffix) st->print("%s", suffix);
1702 C->_in_dump_cnt--;
1703 }
1704
1705 //------------------------------dump_req--------------------------------------
1706 void Node::dump_req(outputStream *st) const {
1707 // Dump the required input edges
1708 for (uint i = 0; i < req(); i++) { // For all required inputs
1709 Node* d = in(i);
1710 if (d == NULL) {
1711 st->print("_ ");
1712 } else if (NotANode(d)) {
1713 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1714 } else {
1715 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1716 }
1717 }
1718 }
1719
1720
1721 //------------------------------dump_prec-------------------------------------
1722 void Node::dump_prec(outputStream *st) const {
1723 // Dump the precedence edges
1724 int any_prec = 0;
1725 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1726 Node* p = in(i);
1727 if (p != NULL) {
1728 if (!any_prec++) st->print(" |");
1729 if (NotANode(p)) { st->print("NotANode "); continue; }
1730 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1731 }
1732 }
1733 }
1734
1735 //------------------------------dump_out--------------------------------------
1736 void Node::dump_out(outputStream *st) const {
1737 // Delimit the output edges
1738 st->print(" [[");
1739 // Dump the output edges
1740 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1741 Node* u = _out[i];
1742 if (u == NULL) {
1743 st->print("_ ");
1744 } else if (NotANode(u)) {
1745 st->print("NotANode ");
1746 } else {
1747 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1748 }
1749 }
1750 st->print("]] ");
1751 }
1752
1753 //----------------------------collect_nodes_i----------------------------------
1754 // Collects nodes from an Ideal graph, starting from a given start node and
1755 // moving in a given direction until a certain depth (distance from the start
1756 // node) is reached. Duplicates are ignored.
1757 // Arguments:
1758 // nstack: the nodes are collected into this array.
1759 // start: the node at which to start collecting.
1760 // direction: if this is a positive number, collect input nodes; if it is
1761 // a negative number, collect output nodes.
1762 // depth: collect nodes up to this distance from the start node.
1763 // include_start: whether to include the start node in the result collection.
1764 // only_ctrl: whether to regard control edges only during traversal.
1765 // only_data: whether to regard data edges only during traversal.
1766 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1767 Node* s = (Node*) start; // remove const
1768 nstack->append(s);
1769 int begin = 0;
1770 int end = 0;
1771 for(uint i = 0; i < depth; i++) {
1772 end = nstack->length();
1773 for(int j = begin; j < end; j++) {
1774 Node* tp = nstack->at(j);
1775 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1776 for(uint k = 0; k < limit; k++) {
1777 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1778
1779 if (NotANode(n)) continue;
1780 // do not recurse through top or the root (would reach unrelated stuff)
1781 if (n->is_Root() || n->is_top()) continue;
1782 if (only_ctrl && !n->is_CFG()) continue;
1783 if (only_data && n->is_CFG()) continue;
1784
1785 bool on_stack = nstack->contains(n);
1786 if (!on_stack) {
1787 nstack->append(n);
1788 }
1789 }
1790 }
1791 begin = end;
1792 }
1793 if (!include_start) {
1794 nstack->remove(s);
1795 }
1796 }
1797
1798 //------------------------------dump_nodes-------------------------------------
1799 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1800 if (NotANode(start)) return;
1801
1802 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1803 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1804
1805 int end = nstack.length();
1806 if (d > 0) {
1807 for(int j = end-1; j >= 0; j--) {
1808 nstack.at(j)->dump();
1809 }
1810 } else {
1811 for(int j = 0; j < end; j++) {
1812 nstack.at(j)->dump();
1813 }
1814 }
1815 }
1816
1817 //------------------------------dump-------------------------------------------
1818 void Node::dump(int d) const {
1819 dump_nodes(this, d, false);
1820 }
1821
1822 //------------------------------dump_ctrl--------------------------------------
1823 // Dump a Node's control history to depth
1824 void Node::dump_ctrl(int d) const {
1825 dump_nodes(this, d, true);
1826 }
1827
1828 //-----------------------------dump_compact------------------------------------
1829 void Node::dump_comp() const {
1830 this->dump_comp("\n");
1831 }
1832
1833 //-----------------------------dump_compact------------------------------------
1834 // Dump a Node in compact representation, i.e., just print its name and index.
1835 // Nodes can specify additional specifics to print in compact representation by
1836 // implementing dump_compact_spec.
1837 void Node::dump_comp(const char* suffix, outputStream *st) const {
1838 Compile* C = Compile::current();
1839 C->_in_dump_cnt++;
1840 st->print("%s(%d)", Name(), _idx);
1841 this->dump_compact_spec(st);
1842 if (suffix) {
1843 st->print("%s", suffix);
1844 }
1845 C->_in_dump_cnt--;
1846 }
1847
1848 //----------------------------dump_related-------------------------------------
1849 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1850 // hand and is determined by the implementation of the virtual method rel.
1851 void Node::dump_related() const {
1852 Compile* C = Compile::current();
1853 GrowableArray <Node *> in_rel(C->unique());
1854 GrowableArray <Node *> out_rel(C->unique());
1855 this->related(&in_rel, &out_rel, false);
1856 for (int i = in_rel.length() - 1; i >= 0; i--) {
1857 in_rel.at(i)->dump();
1858 }
1859 this->dump("\n", true);
1860 for (int i = 0; i < out_rel.length(); i++) {
1861 out_rel.at(i)->dump();
1862 }
1863 }
1864
1865 //----------------------------dump_related-------------------------------------
1866 // Dump a Node's related nodes up to a given depth (distance from the start
1867 // node).
1868 // Arguments:
1869 // d_in: depth for input nodes.
1870 // d_out: depth for output nodes (note: this also is a positive number).
1871 void Node::dump_related(uint d_in, uint d_out) const {
1872 Compile* C = Compile::current();
1873 GrowableArray <Node *> in_rel(C->unique());
1874 GrowableArray <Node *> out_rel(C->unique());
1875
1876 // call collect_nodes_i directly
1877 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1878 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1879
1880 for (int i = in_rel.length() - 1; i >= 0; i--) {
1881 in_rel.at(i)->dump();
1882 }
1883 this->dump("\n", true);
1884 for (int i = 0; i < out_rel.length(); i++) {
1885 out_rel.at(i)->dump();
1886 }
1887 }
1888
1889 //------------------------dump_related_compact---------------------------------
1890 // Dump a Node's related nodes in compact representation. The notion of
1891 // "related" depends on the Node at hand and is determined by the implementation
1892 // of the virtual method rel.
1893 void Node::dump_related_compact() const {
1894 Compile* C = Compile::current();
1895 GrowableArray <Node *> in_rel(C->unique());
1896 GrowableArray <Node *> out_rel(C->unique());
1897 this->related(&in_rel, &out_rel, true);
1898 int n_in = in_rel.length();
1899 int n_out = out_rel.length();
1900
1901 this->dump_comp(n_in == 0 ? "\n" : " ");
1902 for (int i = 0; i < n_in; i++) {
1903 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1904 }
1905 for (int i = 0; i < n_out; i++) {
1906 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1907 }
1908 }
1909
1910 //------------------------------related----------------------------------------
1911 // Collect a Node's related nodes. The default behaviour just collects the
1912 // inputs and outputs at depth 1, including both control and data flow edges,
1913 // regardless of whether the presentation is compact or not. For data nodes,
1914 // the default is to collect all data inputs (till level 1 if compact), and
1915 // outputs till level 1.
1916 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1917 if (this->is_CFG()) {
1918 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1919 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1920 } else {
1921 if (compact) {
1922 this->collect_nodes(in_rel, 1, false, true);
1923 } else {
1924 this->collect_nodes_in_all_data(in_rel, false);
1925 }
1926 this->collect_nodes(out_rel, -1, false, false);
1927 }
1928 }
1929
1930 //---------------------------collect_nodes-------------------------------------
1931 // An entry point to the low-level node collection facility, to start from a
1932 // given node in the graph. The start node is by default not included in the
1933 // result.
1934 // Arguments:
1935 // ns: collect the nodes into this data structure.
1936 // d: the depth (distance from start node) to which nodes should be
1937 // collected. A value >0 indicates input nodes, a value <0, output
1938 // nodes.
1939 // ctrl: include only control nodes.
1940 // data: include only data nodes.
1941 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
1942 if (ctrl && data) {
1943 // ignore nonsensical combination
1944 return;
1945 }
1946 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
1947 }
1948
1949 //--------------------------collect_nodes_in-----------------------------------
1950 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
1951 // The maximum depth is determined using a BFS that visits all primary (data
1952 // or control) inputs and increments the depth at each level.
1953 uint d_in = 0;
1954 GrowableArray<Node*> nodes(Compile::current()->unique());
1955 nodes.push(start);
1956 int nodes_at_current_level = 1;
1957 int n_idx = 0;
1958 while (nodes_at_current_level > 0) {
1959 // Add all primary inputs reachable from the current level to the list, and
1960 // increase the depth if there were any.
1961 int nodes_at_next_level = 0;
1962 bool nodes_added = false;
1963 while (nodes_at_current_level > 0) {
1964 nodes_at_current_level--;
1965 Node* current = nodes.at(n_idx++);
1966 for (uint i = 0; i < current->len(); i++) {
1967 Node* n = current->in(i);
1968 if (NotANode(n)) {
1969 continue;
1970 }
1971 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
1972 continue;
1973 }
1974 if (!nodes.contains(n)) {
1975 nodes.push(n);
1976 nodes_added = true;
1977 nodes_at_next_level++;
1978 }
1979 }
1980 }
1981 if (nodes_added) {
1982 d_in++;
1983 }
1984 nodes_at_current_level = nodes_at_next_level;
1985 }
1986 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
1987 if (collect_secondary) {
1988 // Now, iterate over the secondary nodes in ns and add the respective
1989 // boundary reachable from them.
1990 GrowableArray<Node*> sns(Compile::current()->unique());
1991 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
1992 Node* n = *it;
1993 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
1994 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
1995 ns->append_if_missing(*d);
1996 }
1997 sns.clear();
1998 }
1999 }
2000 }
2001
2002 //---------------------collect_nodes_in_all_data-------------------------------
2003 // Collect the entire data input graph. Include the control boundary if
2004 // requested.
2005 // Arguments:
2006 // ns: collect the nodes into this data structure.
2007 // ctrl: if true, include the control boundary.
2008 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2009 collect_nodes_in((Node*) this, ns, true, ctrl);
2010 }
2011
2012 //--------------------------collect_nodes_in_all_ctrl--------------------------
2013 // Collect the entire control input graph. Include the data boundary if
2014 // requested.
2015 // ns: collect the nodes into this data structure.
2016 // data: if true, include the control boundary.
2017 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2018 collect_nodes_in((Node*) this, ns, false, data);
2019 }
2020
2021 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2022 // Collect the entire output graph until hitting control node boundaries, and
2023 // include those.
2024 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2025 // Perform a BFS and stop at control nodes.
2026 GrowableArray<Node*> nodes(Compile::current()->unique());
2027 nodes.push((Node*) this);
2028 while (nodes.length() > 0) {
2029 Node* current = nodes.pop();
2030 if (NotANode(current)) {
2031 continue;
2032 }
2033 ns->append_if_missing(current);
2034 if (!current->is_CFG()) {
2035 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2036 nodes.push(current->out(i));
2037 }
2038 }
2039 }
2040 ns->remove((Node*) this);
2041 }
2042
2043 // VERIFICATION CODE
2044 // For each input edge to a node (ie - for each Use-Def edge), verify that
2045 // there is a corresponding Def-Use edge.
2046 //------------------------------verify_edges-----------------------------------
2047 void Node::verify_edges(Unique_Node_List &visited) {
2048 uint i, j, idx;
2049 int cnt;
2050 Node *n;
2051
2052 // Recursive termination test
2053 if (visited.member(this)) return;
2054 visited.push(this);
2055
2056 // Walk over all input edges, checking for correspondence
2057 for( i = 0; i < len(); i++ ) {
2058 n = in(i);
2059 if (n != NULL && !n->is_top()) {
2060 // Count instances of (Node *)this
2061 cnt = 0;
2062 for (idx = 0; idx < n->_outcnt; idx++ ) {
2063 if (n->_out[idx] == (Node *)this) cnt++;
2064 }
2065 assert( cnt > 0,"Failed to find Def-Use edge." );
2066 // Check for duplicate edges
2067 // walk the input array downcounting the input edges to n
2068 for( j = 0; j < len(); j++ ) {
2069 if( in(j) == n ) cnt--;
2070 }
2071 assert( cnt == 0,"Mismatched edge count.");
2072 } else if (n == NULL) {
2073 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
2074 } else {
2075 assert(n->is_top(), "sanity");
2076 // Nothing to check.
2077 }
2078 }
2079 // Recursive walk over all input edges
2080 for( i = 0; i < len(); i++ ) {
2081 n = in(i);
2082 if( n != NULL )
2083 in(i)->verify_edges(visited);
2084 }
2085 }
2086
2087 //------------------------------verify_recur-----------------------------------
2088 static const Node *unique_top = NULL;
2089
2090 void Node::verify_recur(const Node *n, int verify_depth,
2091 VectorSet &old_space, VectorSet &new_space) {
2092 if ( verify_depth == 0 ) return;
2093 if (verify_depth > 0) --verify_depth;
2094
2095 Compile* C = Compile::current();
2096
2097 // Contained in new_space or old_space?
2098 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2099 // Check for visited in the proper space. Numberings are not unique
2100 // across spaces so we need a separate VectorSet for each space.
2101 if( v->test_set(n->_idx) ) return;
2102
2103 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2104 if (C->cached_top_node() == NULL)
2105 C->set_cached_top_node((Node*)n);
2106 assert(C->cached_top_node() == n, "TOP node must be unique");
2107 }
2108
2109 for( uint i = 0; i < n->len(); i++ ) {
2110 Node *x = n->in(i);
2111 if (!x || x->is_top()) continue;
2112
2113 // Verify my input has a def-use edge to me
2114 if (true /*VerifyDefUse*/) {
2115 // Count use-def edges from n to x
2116 int cnt = 0;
2117 for( uint j = 0; j < n->len(); j++ )
2118 if( n->in(j) == x )
2119 cnt++;
2120 // Count def-use edges from x to n
2121 uint max = x->_outcnt;
2122 for( uint k = 0; k < max; k++ )
2123 if (x->_out[k] == n)
2124 cnt--;
2125 assert( cnt == 0, "mismatched def-use edge counts" );
2126 }
2127
2128 verify_recur(x, verify_depth, old_space, new_space);
2129 }
2130
2131 }
2132
2133 //------------------------------verify-----------------------------------------
2134 // Check Def-Use info for my subgraph
2135 void Node::verify() const {
2136 Compile* C = Compile::current();
2137 Node* old_top = C->cached_top_node();
2138 ResourceMark rm;
2139 ResourceArea *area = Thread::current()->resource_area();
2140 VectorSet old_space(area), new_space(area);
2141 verify_recur(this, -1, old_space, new_space);
2142 C->set_cached_top_node(old_top);
2143 }
2144 #endif
2145
2146
2147 //------------------------------walk-------------------------------------------
2148 // Graph walk, with both pre-order and post-order functions
2149 void Node::walk(NFunc pre, NFunc post, void *env) {
2150 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2151 walk_(pre, post, env, visited);
2152 }
2153
2154 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2155 if( visited.test_set(_idx) ) return;
2156 pre(*this,env); // Call the pre-order walk function
2157 for( uint i=0; i<_max; i++ )
2158 if( in(i) ) // Input exists and is not walked?
2159 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2160 post(*this,env); // Call the post-order walk function
2161 }
2162
2163 void Node::nop(Node &, void*) {}
2164
2165 //------------------------------Registers--------------------------------------
2166 // Do we Match on this edge index or not? Generally false for Control
2167 // and true for everything else. Weird for calls & returns.
2168 uint Node::match_edge(uint idx) const {
2169 return idx; // True for other than index 0 (control)
2170 }
2171
2172 static RegMask _not_used_at_all;
2173 // Register classes are defined for specific machines
2174 const RegMask &Node::out_RegMask() const {
2175 ShouldNotCallThis();
2176 return _not_used_at_all;
2177 }
2178
2179 const RegMask &Node::in_RegMask(uint) const {
2180 ShouldNotCallThis();
2181 return _not_used_at_all;
2182 }
2183
2184 //=============================================================================
2185 //-----------------------------------------------------------------------------
2186 void Node_Array::reset( Arena *new_arena ) {
2187 _a->Afree(_nodes,_max*sizeof(Node*));
2188 _max = 0;
2189 _nodes = NULL;
2190 _a = new_arena;
2191 }
2192
2193 //------------------------------clear------------------------------------------
2194 // Clear all entries in _nodes to NULL but keep storage
2195 void Node_Array::clear() {
2196 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2197 }
2198
2199 //-----------------------------------------------------------------------------
2200 void Node_Array::grow( uint i ) {
2201 if( !_max ) {
2202 _max = 1;
2203 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2204 _nodes[0] = NULL;
2205 }
2206 uint old = _max;
2207 while( i >= _max ) _max <<= 1; // Double to fit
2208 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2209 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2210 }
2211
2212 //-----------------------------------------------------------------------------
2213 void Node_Array::insert( uint i, Node *n ) {
2214 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2215 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2216 _nodes[i] = n;
2217 }
2218
2219 //-----------------------------------------------------------------------------
2220 void Node_Array::remove( uint i ) {
2221 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2222 _nodes[_max-1] = NULL;
2223 }
2224
2225 //-----------------------------------------------------------------------------
2226 void Node_Array::sort( C_sort_func_t func) {
2227 qsort( _nodes, _max, sizeof( Node* ), func );
2228 }
2229
2230 //-----------------------------------------------------------------------------
2231 void Node_Array::dump() const {
2232 #ifndef PRODUCT
2233 for( uint i = 0; i < _max; i++ ) {
2234 Node *nn = _nodes[i];
2235 if( nn != NULL ) {
2236 tty->print("%5d--> ",i); nn->dump();
2237 }
2238 }
2239 #endif
2240 }
2241
2242 //--------------------------is_iteratively_computed------------------------------
2243 // Operation appears to be iteratively computed (such as an induction variable)
2244 // It is possible for this operation to return false for a loop-varying
2245 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2246 bool Node::is_iteratively_computed() {
2247 if (ideal_reg()) { // does operation have a result register?
2248 for (uint i = 1; i < req(); i++) {
2249 Node* n = in(i);
2250 if (n != NULL && n->is_Phi()) {
2251 for (uint j = 1; j < n->req(); j++) {
2252 if (n->in(j) == this) {
2253 return true;
2254 }
2255 }
2256 }
2257 }
2258 }
2259 return false;
2260 }
2261
2262 //--------------------------find_similar------------------------------
2263 // Return a node with opcode "opc" and same inputs as "this" if one can
2264 // be found; Otherwise return NULL;
2265 Node* Node::find_similar(int opc) {
2266 if (req() >= 2) {
2267 Node* def = in(1);
2268 if (def && def->outcnt() >= 2) {
2269 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2270 Node* use = def->fast_out(i);
2271 if (use->Opcode() == opc &&
2272 use->req() == req()) {
2273 uint j;
2274 for (j = 0; j < use->req(); j++) {
2275 if (use->in(j) != in(j)) {
2276 break;
2277 }
2278 }
2279 if (j == use->req()) {
2280 return use;
2281 }
2282 }
2283 }
2284 }
2285 }
2286 return NULL;
2287 }
2288
2289
2290 //--------------------------unique_ctrl_out------------------------------
2291 // Return the unique control out if only one. Null if none or more than one.
2292 Node* Node::unique_ctrl_out() const {
2293 Node* found = NULL;
2294 for (uint i = 0; i < outcnt(); i++) {
2295 Node* use = raw_out(i);
2296 if (use->is_CFG() && use != this) {
2297 if (found != NULL) return NULL;
2298 found = use;
2299 }
2300 }
2301 return found;
2302 }
2303
2304 void Node::ensure_control_or_add_prec(Node* c) {
2305 if (in(0) == NULL) {
2306 set_req(0, c);
2307 } else if (in(0) != c) {
2308 add_prec(c);
2309 }
2310 }
2311
2312 //=============================================================================
2313 //------------------------------yank-------------------------------------------
2314 // Find and remove
2315 void Node_List::yank( Node *n ) {
2316 uint i;
2317 for( i = 0; i < _cnt; i++ )
2318 if( _nodes[i] == n )
2319 break;
2320
2321 if( i < _cnt )
2322 _nodes[i] = _nodes[--_cnt];
2323 }
2324
2325 //------------------------------dump-------------------------------------------
2326 void Node_List::dump() const {
2327 #ifndef PRODUCT
2328 for( uint i = 0; i < _cnt; i++ )
2329 if( _nodes[i] ) {
2330 tty->print("%5d--> ",i);
2331 _nodes[i]->dump();
2332 }
2333 #endif
2334 }
2335
2336 //=============================================================================
2337 //------------------------------remove-----------------------------------------
2338 void Unique_Node_List::remove( Node *n ) {
2339 if( _in_worklist[n->_idx] ) {
2340 for( uint i = 0; i < size(); i++ )
2341 if( _nodes[i] == n ) {
2342 map(i,Node_List::pop());
2343 _in_worklist >>= n->_idx;
2344 return;
2345 }
2346 ShouldNotReachHere();
2347 }
2348 }
2349
2350 //-----------------------remove_useless_nodes----------------------------------
2351 // Remove useless nodes from worklist
2352 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2353
2354 for( uint i = 0; i < size(); ++i ) {
2355 Node *n = at(i);
2356 assert( n != NULL, "Did not expect null entries in worklist");
2357 if( ! useful.test(n->_idx) ) {
2358 _in_worklist >>= n->_idx;
2359 map(i,Node_List::pop());
2360 // Node *replacement = Node_List::pop();
2361 // if( i != size() ) { // Check if removing last entry
2362 // _nodes[i] = replacement;
2363 // }
2364 --i; // Visit popped node
2365 // If it was last entry, loop terminates since size() was also reduced
2366 }
2367 }
2368 }
2369
2370 //=============================================================================
2371 void Node_Stack::grow() {
2372 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2373 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2374 size_t max = old_max << 1; // max * 2
2375 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2376 _inode_max = _inodes + max;
2377 _inode_top = _inodes + old_top; // restore _top
2378 }
2379
2380 // Node_Stack is used to map nodes.
2381 Node* Node_Stack::find(uint idx) const {
2382 uint sz = size();
2383 for (uint i=0; i < sz; i++) {
2384 if (idx == index_at(i) )
2385 return node_at(i);
2386 }
2387 return NULL;
2388 }
2389
2390 //=============================================================================
2391 uint TypeNode::size_of() const { return sizeof(*this); }
2392 #ifndef PRODUCT
2393 void TypeNode::dump_spec(outputStream *st) const {
2394 if( !Verbose && !WizardMode ) {
2395 // standard dump does this in Verbose and WizardMode
2396 st->print(" #"); _type->dump_on(st);
2397 }
2398 }
2399
2400 void TypeNode::dump_compact_spec(outputStream *st) const {
2401 st->print("#");
2402 _type->dump_on(st);
2403 }
2404 #endif
2405 uint TypeNode::hash() const {
2406 return Node::hash() + _type->hash();
2407 }
2408 uint TypeNode::cmp( const Node &n ) const
2409 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2410 const Type *TypeNode::bottom_type() const { return _type; }
2411 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2412
2413 //------------------------------ideal_reg--------------------------------------
2414 uint TypeNode::ideal_reg() const {
2415 return _type->ideal_reg();
2416 }