1 /*
2 * Copyright (c) 1997, 2012, 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/machnode.hpp"
31 #include "opto/matcher.hpp"
32 #include "opto/node.hpp"
33 #include "opto/opcodes.hpp"
34 #include "opto/regmask.hpp"
35 #include "opto/type.hpp"
36 #include "utilities/copy.hpp"
37
38 class RegMask;
39 // #include "phase.hpp"
40 class PhaseTransform;
41 class PhaseGVN;
42
43 // Arena we are currently building Nodes in
44 const uint Node::NotAMachineReg = 0xffff0000;
45
46 #ifndef PRODUCT
47 extern int nodes_created;
48 #endif
49
50 #ifdef ASSERT
51
52 //-------------------------- construct_node------------------------------------
53 // Set a breakpoint here to identify where a particular node index is built.
54 void Node::verify_construction() {
55 _debug_orig = NULL;
56 int old_debug_idx = Compile::debug_idx();
57 int new_debug_idx = old_debug_idx+1;
58 if (new_debug_idx > 0) {
59 // Arrange that the lowest five decimal digits of _debug_idx
60 // will repeat those of _idx. In case this is somehow pathological,
61 // we continue to assign negative numbers (!) consecutively.
62 const int mod = 100000;
63 int bump = (int)(_idx - new_debug_idx) % mod;
64 if (bump < 0) bump += mod;
65 assert(bump >= 0 && bump < mod, "");
66 new_debug_idx += bump;
67 }
68 Compile::set_debug_idx(new_debug_idx);
69 set_debug_idx( new_debug_idx );
70 assert(Compile::current()->unique() < (UINT_MAX - 1), "Node limit exceeded UINT_MAX");
71 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
72 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
73 BREAKPOINT;
74 }
75 #if OPTO_DU_ITERATOR_ASSERT
76 _last_del = NULL;
77 _del_tick = 0;
78 #endif
79 _hash_lock = 0;
80 }
81
82
83 // #ifdef ASSERT ...
84
85 #if OPTO_DU_ITERATOR_ASSERT
86 void DUIterator_Common::sample(const Node* node) {
87 _vdui = VerifyDUIterators;
88 _node = node;
89 _outcnt = node->_outcnt;
90 _del_tick = node->_del_tick;
91 _last = NULL;
92 }
93
94 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
95 assert(_node == node, "consistent iterator source");
96 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
97 }
98
99 void DUIterator_Common::verify_resync() {
100 // Ensure that the loop body has just deleted the last guy produced.
101 const Node* node = _node;
102 // Ensure that at least one copy of the last-seen edge was deleted.
103 // Note: It is OK to delete multiple copies of the last-seen edge.
104 // Unfortunately, we have no way to verify that all the deletions delete
105 // that same edge. On this point we must use the Honor System.
106 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
107 assert(node->_last_del == _last, "must have deleted the edge just produced");
108 // We liked this deletion, so accept the resulting outcnt and tick.
109 _outcnt = node->_outcnt;
110 _del_tick = node->_del_tick;
111 }
112
113 void DUIterator_Common::reset(const DUIterator_Common& that) {
114 if (this == &that) return; // ignore assignment to self
115 if (!_vdui) {
116 // We need to initialize everything, overwriting garbage values.
117 _last = that._last;
118 _vdui = that._vdui;
119 }
120 // Note: It is legal (though odd) for an iterator over some node x
121 // to be reassigned to iterate over another node y. Some doubly-nested
122 // progress loops depend on being able to do this.
123 const Node* node = that._node;
124 // Re-initialize everything, except _last.
125 _node = node;
126 _outcnt = node->_outcnt;
127 _del_tick = node->_del_tick;
128 }
129
130 void DUIterator::sample(const Node* node) {
131 DUIterator_Common::sample(node); // Initialize the assertion data.
132 _refresh_tick = 0; // No refreshes have happened, as yet.
133 }
134
135 void DUIterator::verify(const Node* node, bool at_end_ok) {
136 DUIterator_Common::verify(node, at_end_ok);
137 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
138 }
139
140 void DUIterator::verify_increment() {
141 if (_refresh_tick & 1) {
142 // We have refreshed the index during this loop.
143 // Fix up _idx to meet asserts.
144 if (_idx > _outcnt) _idx = _outcnt;
145 }
146 verify(_node, true);
147 }
148
149 void DUIterator::verify_resync() {
150 // Note: We do not assert on _outcnt, because insertions are OK here.
151 DUIterator_Common::verify_resync();
152 // Make sure we are still in sync, possibly with no more out-edges:
153 verify(_node, true);
154 }
155
156 void DUIterator::reset(const DUIterator& that) {
157 if (this == &that) return; // self assignment is always a no-op
158 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
159 assert(that._idx == 0, "assign only the result of Node::outs()");
160 assert(_idx == that._idx, "already assigned _idx");
161 if (!_vdui) {
162 // We need to initialize everything, overwriting garbage values.
163 sample(that._node);
164 } else {
165 DUIterator_Common::reset(that);
166 if (_refresh_tick & 1) {
167 _refresh_tick++; // Clear the "was refreshed" flag.
168 }
169 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
170 }
171 }
172
173 void DUIterator::refresh() {
174 DUIterator_Common::sample(_node); // Re-fetch assertion data.
175 _refresh_tick |= 1; // Set the "was refreshed" flag.
176 }
177
178 void DUIterator::verify_finish() {
179 // If the loop has killed the node, do not require it to re-run.
180 if (_node->_outcnt == 0) _refresh_tick &= ~1;
181 // If this assert triggers, it means that a loop used refresh_out_pos
182 // to re-synch an iteration index, but the loop did not correctly
183 // re-run itself, using a "while (progress)" construct.
184 // This iterator enforces the rule that you must keep trying the loop
185 // until it "runs clean" without any need for refreshing.
186 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
187 }
188
189
190 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
191 DUIterator_Common::verify(node, at_end_ok);
192 Node** out = node->_out;
193 uint cnt = node->_outcnt;
194 assert(cnt == _outcnt, "no insertions allowed");
195 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
196 // This last check is carefully designed to work for NO_OUT_ARRAY.
197 }
198
199 void DUIterator_Fast::verify_limit() {
200 const Node* node = _node;
201 verify(node, true);
202 assert(_outp == node->_out + node->_outcnt, "limit still correct");
203 }
204
205 void DUIterator_Fast::verify_resync() {
206 const Node* node = _node;
207 if (_outp == node->_out + _outcnt) {
208 // Note that the limit imax, not the pointer i, gets updated with the
209 // exact count of deletions. (For the pointer it's always "--i".)
210 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
211 // This is a limit pointer, with a name like "imax".
212 // Fudge the _last field so that the common assert will be happy.
213 _last = (Node*) node->_last_del;
214 DUIterator_Common::verify_resync();
215 } else {
216 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
217 // A normal internal pointer.
218 DUIterator_Common::verify_resync();
219 // Make sure we are still in sync, possibly with no more out-edges:
220 verify(node, true);
221 }
222 }
223
224 void DUIterator_Fast::verify_relimit(uint n) {
225 const Node* node = _node;
226 assert((int)n > 0, "use imax -= n only with a positive count");
227 // This must be a limit pointer, with a name like "imax".
228 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
229 // The reported number of deletions must match what the node saw.
230 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
231 // Fudge the _last field so that the common assert will be happy.
232 _last = (Node*) node->_last_del;
233 DUIterator_Common::verify_resync();
234 }
235
236 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
237 assert(_outp == that._outp, "already assigned _outp");
238 DUIterator_Common::reset(that);
239 }
240
241 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
242 // at_end_ok means the _outp is allowed to underflow by 1
243 _outp += at_end_ok;
244 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
245 _outp -= at_end_ok;
246 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
247 }
248
249 void DUIterator_Last::verify_limit() {
250 // Do not require the limit address to be resynched.
251 //verify(node, true);
252 assert(_outp == _node->_out, "limit still correct");
253 }
254
255 void DUIterator_Last::verify_step(uint num_edges) {
256 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
257 _outcnt -= num_edges;
258 _del_tick += num_edges;
259 // Make sure we are still in sync, possibly with no more out-edges:
260 const Node* node = _node;
261 verify(node, true);
262 assert(node->_last_del == _last, "must have deleted the edge just produced");
263 }
264
265 #endif //OPTO_DU_ITERATOR_ASSERT
266
267
268 #endif //ASSERT
269
270
271 // This constant used to initialize _out may be any non-null value.
272 // The value NULL is reserved for the top node only.
273 #define NO_OUT_ARRAY ((Node**)-1)
274
275 // This funny expression handshakes with Node::operator new
276 // to pull Compile::current out of the new node's _out field,
277 // and then calls a subroutine which manages most field
278 // initializations. The only one which is tricky is the
279 // _idx field, which is const, and so must be initialized
280 // by a return value, not an assignment.
281 //
282 // (Aren't you thankful that Java finals don't require so many tricks?)
283 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
284 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
285 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
286 #endif
287
288 // Out-of-line code from node constructors.
289 // Executed only when extra debug info. is being passed around.
290 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
291 C->set_node_notes_at(idx, nn);
292 }
293
294 // Shared initialization code.
295 inline int Node::Init(int req, Compile* C) {
296 assert(Compile::current() == C, "must use operator new(Compile*)");
297 int idx = C->next_unique();
298
299 // Allocate memory for the necessary number of edges.
300 if (req > 0) {
301 // Allocate space for _in array to have double alignment.
302 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
303 #ifdef ASSERT
304 _in[req-1] = this; // magic cookie for assertion check
305 #endif
306 }
307 // If there are default notes floating around, capture them:
308 Node_Notes* nn = C->default_node_notes();
309 if (nn != NULL) init_node_notes(C, idx, nn);
310
311 // Note: At this point, C is dead,
312 // and we begin to initialize the new Node.
313
314 _cnt = _max = req;
315 _outcnt = _outmax = 0;
316 _class_id = Class_Node;
317 _flags = 0;
318 _out = NO_OUT_ARRAY;
319 return idx;
320 }
321
322 //------------------------------Node-------------------------------------------
323 // Create a Node, with a given number of required edges.
324 Node::Node(uint req)
325 : _idx(IDX_INIT(req))
326 {
327 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
328 debug_only( verify_construction() );
329 NOT_PRODUCT(nodes_created++);
330 if (req == 0) {
331 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
332 _in = NULL;
333 } else {
334 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
335 Node** to = _in;
336 for(uint i = 0; i < req; i++) {
337 to[i] = NULL;
338 }
339 }
340 }
341
342 //------------------------------Node-------------------------------------------
343 Node::Node(Node *n0)
344 : _idx(IDX_INIT(1))
345 {
346 debug_only( verify_construction() );
347 NOT_PRODUCT(nodes_created++);
348 // Assert we allocated space for input array already
349 assert( _in[0] == this, "Must pass arg count to 'new'" );
350 assert( is_not_dead(n0), "can not use dead node");
351 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
352 }
353
354 //------------------------------Node-------------------------------------------
355 Node::Node(Node *n0, Node *n1)
356 : _idx(IDX_INIT(2))
357 {
358 debug_only( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 // Assert we allocated space for input array already
361 assert( _in[1] == this, "Must pass arg count to 'new'" );
362 assert( is_not_dead(n0), "can not use dead node");
363 assert( is_not_dead(n1), "can not use dead node");
364 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
365 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
366 }
367
368 //------------------------------Node-------------------------------------------
369 Node::Node(Node *n0, Node *n1, Node *n2)
370 : _idx(IDX_INIT(3))
371 {
372 debug_only( verify_construction() );
373 NOT_PRODUCT(nodes_created++);
374 // Assert we allocated space for input array already
375 assert( _in[2] == this, "Must pass arg count to 'new'" );
376 assert( is_not_dead(n0), "can not use dead node");
377 assert( is_not_dead(n1), "can not use dead node");
378 assert( is_not_dead(n2), "can not use dead node");
379 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
380 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
381 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
382 }
383
384 //------------------------------Node-------------------------------------------
385 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
386 : _idx(IDX_INIT(4))
387 {
388 debug_only( verify_construction() );
389 NOT_PRODUCT(nodes_created++);
390 // Assert we allocated space for input array already
391 assert( _in[3] == this, "Must pass arg count to 'new'" );
392 assert( is_not_dead(n0), "can not use dead node");
393 assert( is_not_dead(n1), "can not use dead node");
394 assert( is_not_dead(n2), "can not use dead node");
395 assert( is_not_dead(n3), "can not use dead node");
396 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
397 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
398 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
399 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
400 }
401
402 //------------------------------Node-------------------------------------------
403 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
404 : _idx(IDX_INIT(5))
405 {
406 debug_only( verify_construction() );
407 NOT_PRODUCT(nodes_created++);
408 // Assert we allocated space for input array already
409 assert( _in[4] == this, "Must pass arg count to 'new'" );
410 assert( is_not_dead(n0), "can not use dead node");
411 assert( is_not_dead(n1), "can not use dead node");
412 assert( is_not_dead(n2), "can not use dead node");
413 assert( is_not_dead(n3), "can not use dead node");
414 assert( is_not_dead(n4), "can not use dead node");
415 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
416 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
417 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
418 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
419 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
420 }
421
422 //------------------------------Node-------------------------------------------
423 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
424 Node *n4, Node *n5)
425 : _idx(IDX_INIT(6))
426 {
427 debug_only( verify_construction() );
428 NOT_PRODUCT(nodes_created++);
429 // Assert we allocated space for input array already
430 assert( _in[5] == this, "Must pass arg count to 'new'" );
431 assert( is_not_dead(n0), "can not use dead node");
432 assert( is_not_dead(n1), "can not use dead node");
433 assert( is_not_dead(n2), "can not use dead node");
434 assert( is_not_dead(n3), "can not use dead node");
435 assert( is_not_dead(n4), "can not use dead node");
436 assert( is_not_dead(n5), "can not use dead node");
437 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
438 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
439 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
440 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
441 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
442 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
443 }
444
445 //------------------------------Node-------------------------------------------
446 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
447 Node *n4, Node *n5, Node *n6)
448 : _idx(IDX_INIT(7))
449 {
450 debug_only( verify_construction() );
451 NOT_PRODUCT(nodes_created++);
452 // Assert we allocated space for input array already
453 assert( _in[6] == this, "Must pass arg count to 'new'" );
454 assert( is_not_dead(n0), "can not use dead node");
455 assert( is_not_dead(n1), "can not use dead node");
456 assert( is_not_dead(n2), "can not use dead node");
457 assert( is_not_dead(n3), "can not use dead node");
458 assert( is_not_dead(n4), "can not use dead node");
459 assert( is_not_dead(n5), "can not use dead node");
460 assert( is_not_dead(n6), "can not use dead node");
461 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
462 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
463 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
464 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
465 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
466 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
467 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
468 }
469
470
471 //------------------------------clone------------------------------------------
472 // Clone a Node.
473 Node *Node::clone() const {
474 Compile *compile = Compile::current();
475 uint s = size_of(); // Size of inherited Node
476 Node *n = (Node*)compile->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
477 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
478 // Set the new input pointer array
479 n->_in = (Node**)(((char*)n)+s);
480 // Cannot share the old output pointer array, so kill it
481 n->_out = NO_OUT_ARRAY;
482 // And reset the counters to 0
483 n->_outcnt = 0;
484 n->_outmax = 0;
485 // Unlock this guy, since he is not in any hash table.
486 debug_only(n->_hash_lock = 0);
487 // Walk the old node's input list to duplicate its edges
488 uint i;
489 for( i = 0; i < len(); i++ ) {
490 Node *x = in(i);
491 n->_in[i] = x;
492 if (x != NULL) x->add_out(n);
493 }
494 if (is_macro())
495 compile->add_macro_node(n);
496 if (is_expensive())
497 compile->add_expensive_node(n);
498
499 n->set_idx(compile->next_unique()); // Get new unique index as well
500 debug_only( n->verify_construction() );
501 NOT_PRODUCT(nodes_created++);
502 // Do not patch over the debug_idx of a clone, because it makes it
503 // impossible to break on the clone's moment of creation.
504 //debug_only( n->set_debug_idx( debug_idx() ) );
505
506 compile->copy_node_notes_to(n, (Node*) this);
507
508 // MachNode clone
509 uint nopnds;
510 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
511 MachNode *mach = n->as_Mach();
512 MachNode *mthis = this->as_Mach();
513 // Get address of _opnd_array.
514 // It should be the same offset since it is the clone of this node.
515 MachOper **from = mthis->_opnds;
516 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
517 pointer_delta((const void*)from,
518 (const void*)(&mthis->_opnds), 1));
519 mach->_opnds = to;
520 for ( uint i = 0; i < nopnds; ++i ) {
521 to[i] = from[i]->clone(compile);
522 }
523 }
524 // cloning CallNode may need to clone JVMState
525 if (n->is_Call()) {
526 CallNode *call = n->as_Call();
527 call->clone_jvms();
528 }
529 return n; // Return the clone
530 }
531
532 //---------------------------setup_is_top--------------------------------------
533 // Call this when changing the top node, to reassert the invariants
534 // required by Node::is_top. See Compile::set_cached_top_node.
535 void Node::setup_is_top() {
536 if (this == (Node*)Compile::current()->top()) {
537 // This node has just become top. Kill its out array.
538 _outcnt = _outmax = 0;
539 _out = NULL; // marker value for top
540 assert(is_top(), "must be top");
541 } else {
542 if (_out == NULL) _out = NO_OUT_ARRAY;
543 assert(!is_top(), "must not be top");
544 }
545 }
546
547
548 //------------------------------~Node------------------------------------------
549 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
550 extern int reclaim_idx ;
551 extern int reclaim_in ;
552 extern int reclaim_node;
553 void Node::destruct() {
554 // Eagerly reclaim unique Node numberings
555 Compile* compile = Compile::current();
556 if ((uint)_idx+1 == compile->unique()) {
557 compile->set_unique(compile->unique()-1);
558 #ifdef ASSERT
559 reclaim_idx++;
560 #endif
561 }
562 // Clear debug info:
563 Node_Notes* nn = compile->node_notes_at(_idx);
564 if (nn != NULL) nn->clear();
565 // Walk the input array, freeing the corresponding output edges
566 _cnt = _max; // forget req/prec distinction
567 uint i;
568 for( i = 0; i < _max; i++ ) {
569 set_req(i, NULL);
570 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
571 }
572 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
573 // See if the input array was allocated just prior to the object
574 int edge_size = _max*sizeof(void*);
575 int out_edge_size = _outmax*sizeof(void*);
576 char *edge_end = ((char*)_in) + edge_size;
577 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
578 char *out_edge_end = out_array + out_edge_size;
579 int node_size = size_of();
580
581 // Free the output edge array
582 if (out_edge_size > 0) {
583 #ifdef ASSERT
584 if( out_edge_end == compile->node_arena()->hwm() )
585 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
586 #endif
587 compile->node_arena()->Afree(out_array, out_edge_size);
588 }
589
590 // Free the input edge array and the node itself
591 if( edge_end == (char*)this ) {
592 #ifdef ASSERT
593 if( edge_end+node_size == compile->node_arena()->hwm() ) {
594 reclaim_in += edge_size;
595 reclaim_node+= node_size;
596 }
597 #else
598 // It was; free the input array and object all in one hit
599 compile->node_arena()->Afree(_in,edge_size+node_size);
600 #endif
601 } else {
602
603 // Free just the input array
604 #ifdef ASSERT
605 if( edge_end == compile->node_arena()->hwm() )
606 reclaim_in += edge_size;
607 #endif
608 compile->node_arena()->Afree(_in,edge_size);
609
610 // Free just the object
611 #ifdef ASSERT
612 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
613 reclaim_node+= node_size;
614 #else
615 compile->node_arena()->Afree(this,node_size);
616 #endif
617 }
618 if (is_macro()) {
619 compile->remove_macro_node(this);
620 }
621 if (is_expensive()) {
622 compile->remove_expensive_node(this);
623 }
624 #ifdef ASSERT
625 // We will not actually delete the storage, but we'll make the node unusable.
626 *(address*)this = badAddress; // smash the C++ vtbl, probably
627 _in = _out = (Node**) badAddress;
628 _max = _cnt = _outmax = _outcnt = 0;
629 #endif
630 }
631
632 //------------------------------grow-------------------------------------------
633 // Grow the input array, making space for more edges
634 void Node::grow( uint len ) {
635 Arena* arena = Compile::current()->node_arena();
636 uint new_max = _max;
637 if( new_max == 0 ) {
638 _max = 4;
639 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
640 Node** to = _in;
641 to[0] = NULL;
642 to[1] = NULL;
643 to[2] = NULL;
644 to[3] = NULL;
645 return;
646 }
647 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
648 // Trimming to limit allows a uint8 to handle up to 255 edges.
649 // Previously I was using only powers-of-2 which peaked at 128 edges.
650 //if( new_max >= limit ) new_max = limit-1;
651 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
652 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
653 _max = new_max; // Record new max length
654 // This assertion makes sure that Node::_max is wide enough to
655 // represent the numerical value of new_max.
656 assert(_max == new_max && _max > len, "int width of _max is too small");
657 }
658
659 //-----------------------------out_grow----------------------------------------
660 // Grow the input array, making space for more edges
661 void Node::out_grow( uint len ) {
662 assert(!is_top(), "cannot grow a top node's out array");
663 Arena* arena = Compile::current()->node_arena();
664 uint new_max = _outmax;
665 if( new_max == 0 ) {
666 _outmax = 4;
667 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
668 return;
669 }
670 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
671 // Trimming to limit allows a uint8 to handle up to 255 edges.
672 // Previously I was using only powers-of-2 which peaked at 128 edges.
673 //if( new_max >= limit ) new_max = limit-1;
674 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
675 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
676 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
677 _outmax = new_max; // Record new max length
678 // This assertion makes sure that Node::_max is wide enough to
679 // represent the numerical value of new_max.
680 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
681 }
682
683 #ifdef ASSERT
684 //------------------------------is_dead----------------------------------------
685 bool Node::is_dead() const {
686 // Mach and pinch point nodes may look like dead.
687 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
688 return false;
689 for( uint i = 0; i < _max; i++ )
690 if( _in[i] != NULL )
691 return false;
692 dump();
693 return true;
694 }
695 #endif
696
697
698 //------------------------------is_unreachable---------------------------------
699 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
700 assert(!is_Mach(), "doesn't work with MachNodes");
701 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
702 }
703
704 //------------------------------add_req----------------------------------------
705 // Add a new required input at the end
706 void Node::add_req( Node *n ) {
707 assert( is_not_dead(n), "can not use dead node");
708
709 // Look to see if I can move precedence down one without reallocating
710 if( (_cnt >= _max) || (in(_max-1) != NULL) )
711 grow( _max+1 );
712
713 // Find a precedence edge to move
714 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
715 uint i;
716 for( i=_cnt; i<_max; i++ )
717 if( in(i) == NULL ) // Find the NULL at end of prec edge list
718 break; // There must be one, since we grew the array
719 _in[i] = in(_cnt); // Move prec over, making space for req edge
720 }
721 _in[_cnt++] = n; // Stuff over old prec edge
722 if (n != NULL) n->add_out((Node *)this);
723 }
724
725 //---------------------------add_req_batch-------------------------------------
726 // Add a new required input at the end
727 void Node::add_req_batch( Node *n, uint m ) {
728 assert( is_not_dead(n), "can not use dead node");
729 // check various edge cases
730 if ((int)m <= 1) {
731 assert((int)m >= 0, "oob");
732 if (m != 0) add_req(n);
733 return;
734 }
735
736 // Look to see if I can move precedence down one without reallocating
737 if( (_cnt+m) > _max || _in[_max-m] )
738 grow( _max+m );
739
740 // Find a precedence edge to move
741 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
742 uint i;
743 for( i=_cnt; i<_max; i++ )
744 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
745 break; // There must be one, since we grew the array
746 // Slide all the precs over by m positions (assume #prec << m).
747 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
748 }
749
750 // Stuff over the old prec edges
751 for(uint i=0; i<m; i++ ) {
752 _in[_cnt++] = n;
753 }
754
755 // Insert multiple out edges on the node.
756 if (n != NULL && !n->is_top()) {
757 for(uint i=0; i<m; i++ ) {
758 n->add_out((Node *)this);
759 }
760 }
761 }
762
763 //------------------------------del_req----------------------------------------
764 // Delete the required edge and compact the edge array
765 void Node::del_req( uint idx ) {
766 assert( idx < _cnt, "oob");
767 assert( !VerifyHashTableKeys || _hash_lock == 0,
768 "remove node from hash table before modifying it");
769 // First remove corresponding def-use edge
770 Node *n = in(idx);
771 if (n != NULL) n->del_out((Node *)this);
772 _in[idx] = in(--_cnt); // Compact the array
773 _in[_cnt] = NULL; // NULL out emptied slot
774 }
775
776 //------------------------------ins_req----------------------------------------
777 // Insert a new required input at the end
778 void Node::ins_req( uint idx, Node *n ) {
779 assert( is_not_dead(n), "can not use dead node");
780 add_req(NULL); // Make space
781 assert( idx < _max, "Must have allocated enough space");
782 // Slide over
783 if(_cnt-idx-1 > 0) {
784 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
785 }
786 _in[idx] = n; // Stuff over old required edge
787 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
788 }
789
790 //-----------------------------find_edge---------------------------------------
791 int Node::find_edge(Node* n) {
792 for (uint i = 0; i < len(); i++) {
793 if (_in[i] == n) return i;
794 }
795 return -1;
796 }
797
798 //----------------------------replace_edge-------------------------------------
799 int Node::replace_edge(Node* old, Node* neww) {
800 if (old == neww) return 0; // nothing to do
801 uint nrep = 0;
802 for (uint i = 0; i < len(); i++) {
803 if (in(i) == old) {
804 if (i < req())
805 set_req(i, neww);
806 else
807 set_prec(i, neww);
808 nrep++;
809 }
810 }
811 return nrep;
812 }
813
814 //-------------------------disconnect_inputs-----------------------------------
815 // NULL out all inputs to eliminate incoming Def-Use edges.
816 // Return the number of edges between 'n' and 'this'
817 int Node::disconnect_inputs(Node *n, Compile* C) {
818 int edges_to_n = 0;
819
820 uint cnt = req();
821 for( uint i = 0; i < cnt; ++i ) {
822 if( in(i) == 0 ) continue;
823 if( in(i) == n ) ++edges_to_n;
824 set_req(i, NULL);
825 }
826 // Remove precedence edges if any exist
827 // Note: Safepoints may have precedence edges, even during parsing
828 if( (req() != len()) && (in(req()) != NULL) ) {
829 uint max = len();
830 for( uint i = 0; i < max; ++i ) {
831 if( in(i) == 0 ) continue;
832 if( in(i) == n ) ++edges_to_n;
833 set_prec(i, NULL);
834 }
835 }
836
837 // Node::destruct requires all out edges be deleted first
838 // debug_only(destruct();) // no reuse benefit expected
839 if (edges_to_n == 0) {
840 C->record_dead_node(_idx);
841 }
842 return edges_to_n;
843 }
844
845 //-----------------------------uncast---------------------------------------
846 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
847 // Strip away casting. (It is depth-limited.)
848 Node* Node::uncast() const {
849 // Should be inline:
850 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
851 if (is_ConstraintCast() || is_CheckCastPP())
852 return uncast_helper(this);
853 else
854 return (Node*) this;
855 }
856
857 //---------------------------uncast_helper-------------------------------------
858 Node* Node::uncast_helper(const Node* p) {
859 #ifdef ASSERT
860 uint depth_count = 0;
861 const Node* orig_p = p;
862 #endif
863
864 while (true) {
865 #ifdef ASSERT
866 if (depth_count >= K) {
867 orig_p->dump(4);
868 if (p != orig_p)
869 p->dump(1);
870 }
871 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
872 #endif
873 if (p == NULL || p->req() != 2) {
874 break;
875 } else if (p->is_ConstraintCast()) {
876 p = p->in(1);
877 } else if (p->is_CheckCastPP()) {
878 p = p->in(1);
879 } else {
880 break;
881 }
882 }
883 return (Node*) p;
884 }
885
886 //------------------------------add_prec---------------------------------------
887 // Add a new precedence input. Precedence inputs are unordered, with
888 // duplicates removed and NULLs packed down at the end.
889 void Node::add_prec( Node *n ) {
890 assert( is_not_dead(n), "can not use dead node");
891
892 // Check for NULL at end
893 if( _cnt >= _max || in(_max-1) )
894 grow( _max+1 );
895
896 // Find a precedence edge to move
897 uint i = _cnt;
898 while( in(i) != NULL ) i++;
899 _in[i] = n; // Stuff prec edge over NULL
900 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
901 }
902
903 //------------------------------rm_prec----------------------------------------
904 // Remove a precedence input. Precedence inputs are unordered, with
905 // duplicates removed and NULLs packed down at the end.
906 void Node::rm_prec( uint j ) {
907
908 // Find end of precedence list to pack NULLs
909 uint i;
910 for( i=j; i<_max; i++ )
911 if( !_in[i] ) // Find the NULL at end of prec edge list
912 break;
913 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
914 _in[j] = _in[--i]; // Move last element over removed guy
915 _in[i] = NULL; // NULL out last element
916 }
917
918 //------------------------------size_of----------------------------------------
919 uint Node::size_of() const { return sizeof(*this); }
920
921 //------------------------------ideal_reg--------------------------------------
922 uint Node::ideal_reg() const { return 0; }
923
924 //------------------------------jvms-------------------------------------------
925 JVMState* Node::jvms() const { return NULL; }
926
927 #ifdef ASSERT
928 //------------------------------jvms-------------------------------------------
929 bool Node::verify_jvms(const JVMState* using_jvms) const {
930 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
931 if (jvms == using_jvms) return true;
932 }
933 return false;
934 }
935
936 //------------------------------init_NodeProperty------------------------------
937 void Node::init_NodeProperty() {
938 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
939 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
940 }
941 #endif
942
943 //------------------------------format-----------------------------------------
944 // Print as assembly
945 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
946 //------------------------------emit-------------------------------------------
947 // Emit bytes starting at parameter 'ptr'.
948 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
949 //------------------------------size-------------------------------------------
950 // Size of instruction in bytes
951 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
952
953 //------------------------------CFG Construction-------------------------------
954 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
955 // Goto and Return.
956 const Node *Node::is_block_proj() const { return 0; }
957
958 // Minimum guaranteed type
959 const Type *Node::bottom_type() const { return Type::BOTTOM; }
960
961
962 //------------------------------raise_bottom_type------------------------------
963 // Get the worst-case Type output for this Node.
964 void Node::raise_bottom_type(const Type* new_type) {
965 if (is_Type()) {
966 TypeNode *n = this->as_Type();
967 if (VerifyAliases) {
968 assert(new_type->higher_equal(n->type()), "new type must refine old type");
969 }
970 n->set_type(new_type);
971 } else if (is_Load()) {
972 LoadNode *n = this->as_Load();
973 if (VerifyAliases) {
974 assert(new_type->higher_equal(n->type()), "new type must refine old type");
975 }
976 n->set_type(new_type);
977 }
978 }
979
980 //------------------------------Identity---------------------------------------
981 // Return a node that the given node is equivalent to.
982 Node *Node::Identity( PhaseTransform * ) {
983 return this; // Default to no identities
984 }
985
986 //------------------------------Value------------------------------------------
987 // Compute a new Type for a node using the Type of the inputs.
988 const Type *Node::Value( PhaseTransform * ) const {
989 return bottom_type(); // Default to worst-case Type
990 }
991
992 //------------------------------Ideal------------------------------------------
993 //
994 // 'Idealize' the graph rooted at this Node.
995 //
996 // In order to be efficient and flexible there are some subtle invariants
997 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
998 // these invariants, although its too slow to have on by default. If you are
999 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1000 //
1001 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1002 // pointer. If ANY change is made, it must return the root of the reshaped
1003 // graph - even if the root is the same Node. Example: swapping the inputs
1004 // to an AddINode gives the same answer and same root, but you still have to
1005 // return the 'this' pointer instead of NULL.
1006 //
1007 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1008 // Identity call to return an old Node; basically if Identity can find
1009 // another Node have the Ideal call make no change and return NULL.
1010 // Example: AddINode::Ideal must check for add of zero; in this case it
1011 // returns NULL instead of doing any graph reshaping.
1012 //
1013 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1014 // sharing there may be other users of the old Nodes relying on their current
1015 // semantics. Modifying them will break the other users.
1016 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1017 // "X+3" unchanged in case it is shared.
1018 //
1019 // If you modify the 'this' pointer's inputs, you should use
1020 // 'set_req'. If you are making a new Node (either as the new root or
1021 // some new internal piece) you may use 'init_req' to set the initial
1022 // value. You can make a new Node with either 'new' or 'clone'. In
1023 // either case, def-use info is correctly maintained.
1024 //
1025 // Example: reshape "(X+3)+4" into "X+7":
1026 // set_req(1, in(1)->in(1));
1027 // set_req(2, phase->intcon(7));
1028 // return this;
1029 // Example: reshape "X*4" into "X<<2"
1030 // return new (C) LShiftINode(in(1), phase->intcon(2));
1031 //
1032 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1033 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1034 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1035 // return new (C) AddINode(shift, in(1));
1036 //
1037 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1038 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1039 // The Right Thing with def-use info.
1040 //
1041 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1042 // graph uses the 'this' Node it must be the root. If you want a Node with
1043 // the same Opcode as the 'this' pointer use 'clone'.
1044 //
1045 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1046 return NULL; // Default to being Ideal already
1047 }
1048
1049 // Some nodes have specific Ideal subgraph transformations only if they are
1050 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1051 // for the transformations to happen.
1052 bool Node::has_special_unique_user() const {
1053 assert(outcnt() == 1, "match only for unique out");
1054 Node* n = unique_out();
1055 int op = Opcode();
1056 if( this->is_Store() ) {
1057 // Condition for back-to-back stores folding.
1058 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1059 } else if( op == Op_AddL ) {
1060 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1061 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1062 } else if( op == Op_SubI || op == Op_SubL ) {
1063 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1064 return n->Opcode() == op && n->in(2) == this;
1065 }
1066 return false;
1067 };
1068
1069 //--------------------------find_exact_control---------------------------------
1070 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1071 Node* Node::find_exact_control(Node* ctrl) {
1072 if (ctrl == NULL && this->is_Region())
1073 ctrl = this->as_Region()->is_copy();
1074
1075 if (ctrl != NULL && ctrl->is_CatchProj()) {
1076 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1077 ctrl = ctrl->in(0);
1078 if (ctrl != NULL && !ctrl->is_top())
1079 ctrl = ctrl->in(0);
1080 }
1081
1082 if (ctrl != NULL && ctrl->is_Proj())
1083 ctrl = ctrl->in(0);
1084
1085 return ctrl;
1086 }
1087
1088 //--------------------------dominates------------------------------------------
1089 // Helper function for MemNode::all_controls_dominate().
1090 // Check if 'this' control node dominates or equal to 'sub' control node.
1091 // We already know that if any path back to Root or Start reaches 'this',
1092 // then all paths so, so this is a simple search for one example,
1093 // not an exhaustive search for a counterexample.
1094 bool Node::dominates(Node* sub, Node_List &nlist) {
1095 assert(this->is_CFG(), "expecting control");
1096 assert(sub != NULL && sub->is_CFG(), "expecting control");
1097
1098 // detect dead cycle without regions
1099 int iterations_without_region_limit = DominatorSearchLimit;
1100
1101 Node* orig_sub = sub;
1102 Node* dom = this;
1103 bool met_dom = false;
1104 nlist.clear();
1105
1106 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1107 // After seeing 'dom', continue up to Root or Start.
1108 // If we hit a region (backward split point), it may be a loop head.
1109 // Keep going through one of the region's inputs. If we reach the
1110 // same region again, go through a different input. Eventually we
1111 // will either exit through the loop head, or give up.
1112 // (If we get confused, break out and return a conservative 'false'.)
1113 while (sub != NULL) {
1114 if (sub->is_top()) break; // Conservative answer for dead code.
1115 if (sub == dom) {
1116 if (nlist.size() == 0) {
1117 // No Region nodes except loops were visited before and the EntryControl
1118 // path was taken for loops: it did not walk in a cycle.
1119 return true;
1120 } else if (met_dom) {
1121 break; // already met before: walk in a cycle
1122 } else {
1123 // Region nodes were visited. Continue walk up to Start or Root
1124 // to make sure that it did not walk in a cycle.
1125 met_dom = true; // first time meet
1126 iterations_without_region_limit = DominatorSearchLimit; // Reset
1127 }
1128 }
1129 if (sub->is_Start() || sub->is_Root()) {
1130 // Success if we met 'dom' along a path to Start or Root.
1131 // We assume there are no alternative paths that avoid 'dom'.
1132 // (This assumption is up to the caller to ensure!)
1133 return met_dom;
1134 }
1135 Node* up = sub->in(0);
1136 // Normalize simple pass-through regions and projections:
1137 up = sub->find_exact_control(up);
1138 // If sub == up, we found a self-loop. Try to push past it.
1139 if (sub == up && sub->is_Loop()) {
1140 // Take loop entry path on the way up to 'dom'.
1141 up = sub->in(1); // in(LoopNode::EntryControl);
1142 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1143 // Always take in(1) path on the way up to 'dom' for clone regions
1144 // (with only one input) or regions which merge > 2 paths
1145 // (usually used to merge fast/slow paths).
1146 up = sub->in(1);
1147 } else if (sub == up && sub->is_Region()) {
1148 // Try both paths for Regions with 2 input paths (it may be a loop head).
1149 // It could give conservative 'false' answer without information
1150 // which region's input is the entry path.
1151 iterations_without_region_limit = DominatorSearchLimit; // Reset
1152
1153 bool region_was_visited_before = false;
1154 // Was this Region node visited before?
1155 // If so, we have reached it because we accidentally took a
1156 // loop-back edge from 'sub' back into the body of the loop,
1157 // and worked our way up again to the loop header 'sub'.
1158 // So, take the first unexplored path on the way up to 'dom'.
1159 for (int j = nlist.size() - 1; j >= 0; j--) {
1160 intptr_t ni = (intptr_t)nlist.at(j);
1161 Node* visited = (Node*)(ni & ~1);
1162 bool visited_twice_already = ((ni & 1) != 0);
1163 if (visited == sub) {
1164 if (visited_twice_already) {
1165 // Visited 2 paths, but still stuck in loop body. Give up.
1166 return false;
1167 }
1168 // The Region node was visited before only once.
1169 // (We will repush with the low bit set, below.)
1170 nlist.remove(j);
1171 // We will find a new edge and re-insert.
1172 region_was_visited_before = true;
1173 break;
1174 }
1175 }
1176
1177 // Find an incoming edge which has not been seen yet; walk through it.
1178 assert(up == sub, "");
1179 uint skip = region_was_visited_before ? 1 : 0;
1180 for (uint i = 1; i < sub->req(); i++) {
1181 Node* in = sub->in(i);
1182 if (in != NULL && !in->is_top() && in != sub) {
1183 if (skip == 0) {
1184 up = in;
1185 break;
1186 }
1187 --skip; // skip this nontrivial input
1188 }
1189 }
1190
1191 // Set 0 bit to indicate that both paths were taken.
1192 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1193 }
1194
1195 if (up == sub) {
1196 break; // some kind of tight cycle
1197 }
1198 if (up == orig_sub && met_dom) {
1199 // returned back after visiting 'dom'
1200 break; // some kind of cycle
1201 }
1202 if (--iterations_without_region_limit < 0) {
1203 break; // dead cycle
1204 }
1205 sub = up;
1206 }
1207
1208 // Did not meet Root or Start node in pred. chain.
1209 // Conservative answer for dead code.
1210 return false;
1211 }
1212
1213 //------------------------------remove_dead_region-----------------------------
1214 // This control node is dead. Follow the subgraph below it making everything
1215 // using it dead as well. This will happen normally via the usual IterGVN
1216 // worklist but this call is more efficient. Do not update use-def info
1217 // inside the dead region, just at the borders.
1218 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1219 // Con's are a popular node to re-hit in the hash table again.
1220 if( dead->is_Con() ) return;
1221
1222 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1223 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1224 Node_List nstack(Thread::current()->resource_area());
1225
1226 Node *top = igvn->C->top();
1227 nstack.push(dead);
1228
1229 while (nstack.size() > 0) {
1230 dead = nstack.pop();
1231 if (dead->outcnt() > 0) {
1232 // Keep dead node on stack until all uses are processed.
1233 nstack.push(dead);
1234 // For all Users of the Dead... ;-)
1235 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1236 Node* use = dead->last_out(k);
1237 igvn->hash_delete(use); // Yank from hash table prior to mod
1238 if (use->in(0) == dead) { // Found another dead node
1239 assert (!use->is_Con(), "Control for Con node should be Root node.");
1240 use->set_req(0, top); // Cut dead edge to prevent processing
1241 nstack.push(use); // the dead node again.
1242 } else { // Else found a not-dead user
1243 for (uint j = 1; j < use->req(); j++) {
1244 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1245 use->set_req(j, top);
1246 }
1247 }
1248 igvn->_worklist.push(use);
1249 }
1250 // Refresh the iterator, since any number of kills might have happened.
1251 k = dead->last_outs(kmin);
1252 }
1253 } else { // (dead->outcnt() == 0)
1254 // Done with outputs.
1255 igvn->hash_delete(dead);
1256 igvn->_worklist.remove(dead);
1257 igvn->set_type(dead, Type::TOP);
1258 if (dead->is_macro()) {
1259 igvn->C->remove_macro_node(dead);
1260 }
1261 if (dead->is_expensive()) {
1262 igvn->C->remove_expensive_node(dead);
1263 }
1264 igvn->C->record_dead_node(dead->_idx);
1265 // Kill all inputs to the dead guy
1266 for (uint i=0; i < dead->req(); i++) {
1267 Node *n = dead->in(i); // Get input to dead guy
1268 if (n != NULL && !n->is_top()) { // Input is valid?
1269 dead->set_req(i, top); // Smash input away
1270 if (n->outcnt() == 0) { // Input also goes dead?
1271 if (!n->is_Con())
1272 nstack.push(n); // Clear it out as well
1273 } else if (n->outcnt() == 1 &&
1274 n->has_special_unique_user()) {
1275 igvn->add_users_to_worklist( n );
1276 } else if (n->outcnt() <= 2 && n->is_Store()) {
1277 // Push store's uses on worklist to enable folding optimization for
1278 // store/store and store/load to the same address.
1279 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1280 // and remove_globally_dead_node().
1281 igvn->add_users_to_worklist( n );
1282 }
1283 }
1284 }
1285 } // (dead->outcnt() == 0)
1286 } // while (nstack.size() > 0) for outputs
1287 return;
1288 }
1289
1290 //------------------------------remove_dead_region-----------------------------
1291 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1292 Node *n = in(0);
1293 if( !n ) return false;
1294 // Lost control into this guy? I.e., it became unreachable?
1295 // Aggressively kill all unreachable code.
1296 if (can_reshape && n->is_top()) {
1297 kill_dead_code(this, phase->is_IterGVN());
1298 return false; // Node is dead.
1299 }
1300
1301 if( n->is_Region() && n->as_Region()->is_copy() ) {
1302 Node *m = n->nonnull_req();
1303 set_req(0, m);
1304 return true;
1305 }
1306 return false;
1307 }
1308
1309 //------------------------------Ideal_DU_postCCP-------------------------------
1310 // Idealize graph, using DU info. Must clone result into new-space
1311 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1312 return NULL; // Default to no change
1313 }
1314
1315 //------------------------------hash-------------------------------------------
1316 // Hash function over Nodes.
1317 uint Node::hash() const {
1318 uint sum = 0;
1319 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1320 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1321 return (sum>>2) + _cnt + Opcode();
1322 }
1323
1324 //------------------------------cmp--------------------------------------------
1325 // Compare special parts of simple Nodes
1326 uint Node::cmp( const Node &n ) const {
1327 return 1; // Must be same
1328 }
1329
1330 //------------------------------rematerialize-----------------------------------
1331 // Should we clone rather than spill this instruction?
1332 bool Node::rematerialize() const {
1333 if ( is_Mach() )
1334 return this->as_Mach()->rematerialize();
1335 else
1336 return (_flags & Flag_rematerialize) != 0;
1337 }
1338
1339 //------------------------------needs_anti_dependence_check---------------------
1340 // Nodes which use memory without consuming it, hence need antidependences.
1341 bool Node::needs_anti_dependence_check() const {
1342 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1343 return false;
1344 else
1345 return in(1)->bottom_type()->has_memory();
1346 }
1347
1348
1349 // Get an integer constant from a ConNode (or CastIINode).
1350 // Return a default value if there is no apparent constant here.
1351 const TypeInt* Node::find_int_type() const {
1352 if (this->is_Type()) {
1353 return this->as_Type()->type()->isa_int();
1354 } else if (this->is_Con()) {
1355 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1356 return this->bottom_type()->isa_int();
1357 }
1358 return NULL;
1359 }
1360
1361 // Get a pointer constant from a ConstNode.
1362 // Returns the constant if it is a pointer ConstNode
1363 intptr_t Node::get_ptr() const {
1364 assert( Opcode() == Op_ConP, "" );
1365 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1366 }
1367
1368 // Get a narrow oop constant from a ConNNode.
1369 intptr_t Node::get_narrowcon() const {
1370 assert( Opcode() == Op_ConN, "" );
1371 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1372 }
1373
1374 // Get a long constant from a ConNode.
1375 // Return a default value if there is no apparent constant here.
1376 const TypeLong* Node::find_long_type() const {
1377 if (this->is_Type()) {
1378 return this->as_Type()->type()->isa_long();
1379 } else if (this->is_Con()) {
1380 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1381 return this->bottom_type()->isa_long();
1382 }
1383 return NULL;
1384 }
1385
1386
1387 /**
1388 * Return a ptr type for nodes which should have it.
1389 */
1390 const TypePtr* Node::get_ptr_type() const {
1391 const TypePtr* tp = this->bottom_type()->make_ptr();
1392 #ifdef ASSERT
1393 if (tp == NULL) {
1394 this->dump(1);
1395 assert((tp != NULL), "unexpected node type");
1396 }
1397 #endif
1398 return tp;
1399 }
1400
1401 // Get a double constant from a ConstNode.
1402 // Returns the constant if it is a double ConstNode
1403 jdouble Node::getd() const {
1404 assert( Opcode() == Op_ConD, "" );
1405 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1406 }
1407
1408 // Get a float constant from a ConstNode.
1409 // Returns the constant if it is a float ConstNode
1410 jfloat Node::getf() const {
1411 assert( Opcode() == Op_ConF, "" );
1412 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1413 }
1414
1415 #ifndef PRODUCT
1416
1417 //----------------------------NotANode----------------------------------------
1418 // Used in debugging code to avoid walking across dead or uninitialized edges.
1419 static inline bool NotANode(const Node* n) {
1420 if (n == NULL) return true;
1421 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1422 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1423 return false;
1424 }
1425
1426
1427 //------------------------------find------------------------------------------
1428 // Find a neighbor of this Node with the given _idx
1429 // If idx is negative, find its absolute value, following both _in and _out.
1430 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1431 VectorSet* old_space, VectorSet* new_space ) {
1432 int node_idx = (idx >= 0) ? idx : -idx;
1433 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1434 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1435 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1436 if( v->test(n->_idx) ) return;
1437 if( (int)n->_idx == node_idx
1438 debug_only(|| n->debug_idx() == node_idx) ) {
1439 if (result != NULL)
1440 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1441 (uintptr_t)result, (uintptr_t)n, node_idx);
1442 result = n;
1443 }
1444 v->set(n->_idx);
1445 for( uint i=0; i<n->len(); i++ ) {
1446 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1447 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1448 }
1449 // Search along forward edges also:
1450 if (idx < 0 && !only_ctrl) {
1451 for( uint j=0; j<n->outcnt(); j++ ) {
1452 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1453 }
1454 }
1455 #ifdef ASSERT
1456 // Search along debug_orig edges last, checking for cycles
1457 Node* orig = n->debug_orig();
1458 if (orig != NULL) {
1459 do {
1460 if (NotANode(orig)) break;
1461 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1462 orig = orig->debug_orig();
1463 } while (orig != NULL && orig != n->debug_orig());
1464 }
1465 #endif //ASSERT
1466 }
1467
1468 // call this from debugger:
1469 Node* find_node(Node* n, int idx) {
1470 return n->find(idx);
1471 }
1472
1473 //------------------------------find-------------------------------------------
1474 Node* Node::find(int idx) const {
1475 ResourceArea *area = Thread::current()->resource_area();
1476 VectorSet old_space(area), new_space(area);
1477 Node* result = NULL;
1478 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1479 return result;
1480 }
1481
1482 //------------------------------find_ctrl--------------------------------------
1483 // Find an ancestor to this node in the control history with given _idx
1484 Node* Node::find_ctrl(int idx) const {
1485 ResourceArea *area = Thread::current()->resource_area();
1486 VectorSet old_space(area), new_space(area);
1487 Node* result = NULL;
1488 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1489 return result;
1490 }
1491 #endif
1492
1493
1494
1495 #ifndef PRODUCT
1496 int Node::_in_dump_cnt = 0;
1497
1498 // -----------------------------Name-------------------------------------------
1499 extern const char *NodeClassNames[];
1500 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1501
1502 static bool is_disconnected(const Node* n) {
1503 for (uint i = 0; i < n->req(); i++) {
1504 if (n->in(i) != NULL) return false;
1505 }
1506 return true;
1507 }
1508
1509 #ifdef ASSERT
1510 static void dump_orig(Node* orig, outputStream *st) {
1511 Compile* C = Compile::current();
1512 if (NotANode(orig)) orig = NULL;
1513 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1514 if (orig == NULL) return;
1515 st->print(" !orig=");
1516 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1517 if (NotANode(fast)) fast = NULL;
1518 while (orig != NULL) {
1519 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1520 if (discon) st->print("[");
1521 if (!Compile::current()->node_arena()->contains(orig))
1522 st->print("o");
1523 st->print("%d", orig->_idx);
1524 if (discon) st->print("]");
1525 orig = orig->debug_orig();
1526 if (NotANode(orig)) orig = NULL;
1527 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1528 if (orig != NULL) st->print(",");
1529 if (fast != NULL) {
1530 // Step fast twice for each single step of orig:
1531 fast = fast->debug_orig();
1532 if (NotANode(fast)) fast = NULL;
1533 if (fast != NULL && fast != orig) {
1534 fast = fast->debug_orig();
1535 if (NotANode(fast)) fast = NULL;
1536 }
1537 if (fast == orig) {
1538 st->print("...");
1539 break;
1540 }
1541 }
1542 }
1543 }
1544
1545 void Node::set_debug_orig(Node* orig) {
1546 _debug_orig = orig;
1547 if (BreakAtNode == 0) return;
1548 if (NotANode(orig)) orig = NULL;
1549 int trip = 10;
1550 while (orig != NULL) {
1551 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1552 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1553 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1554 BREAKPOINT;
1555 }
1556 orig = orig->debug_orig();
1557 if (NotANode(orig)) orig = NULL;
1558 if (trip-- <= 0) break;
1559 }
1560 }
1561 #endif //ASSERT
1562
1563 //------------------------------dump------------------------------------------
1564 // Dump a Node
1565 void Node::dump(const char* suffix, outputStream *st) const {
1566 Compile* C = Compile::current();
1567 bool is_new = C->node_arena()->contains(this);
1568 _in_dump_cnt++;
1569 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1570
1571 // Dump the required and precedence inputs
1572 dump_req(st);
1573 dump_prec(st);
1574 // Dump the outputs
1575 dump_out(st);
1576
1577 if (is_disconnected(this)) {
1578 #ifdef ASSERT
1579 st->print(" [%d]",debug_idx());
1580 dump_orig(debug_orig(), st);
1581 #endif
1582 st->cr();
1583 _in_dump_cnt--;
1584 return; // don't process dead nodes
1585 }
1586
1587 // Dump node-specific info
1588 dump_spec(st);
1589 #ifdef ASSERT
1590 // Dump the non-reset _debug_idx
1591 if (Verbose && WizardMode) {
1592 st->print(" [%d]",debug_idx());
1593 }
1594 #endif
1595
1596 const Type *t = bottom_type();
1597
1598 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1599 const TypeInstPtr *toop = t->isa_instptr();
1600 const TypeKlassPtr *tkls = t->isa_klassptr();
1601 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1602 if (klass && klass->is_loaded() && klass->is_interface()) {
1603 st->print(" Interface:");
1604 } else if (toop) {
1605 st->print(" Oop:");
1606 } else if (tkls) {
1607 st->print(" Klass:");
1608 }
1609 t->dump_on(st);
1610 } else if (t == Type::MEMORY) {
1611 st->print(" Memory:");
1612 MemNode::dump_adr_type(this, adr_type(), st);
1613 } else if (Verbose || WizardMode) {
1614 st->print(" Type:");
1615 if (t) {
1616 t->dump_on(st);
1617 } else {
1618 st->print("no type");
1619 }
1620 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1621 // Dump MachSpillcopy vector type.
1622 t->dump_on(st);
1623 }
1624 if (is_new) {
1625 debug_only(dump_orig(debug_orig(), st));
1626 Node_Notes* nn = C->node_notes_at(_idx);
1627 if (nn != NULL && !nn->is_clear()) {
1628 if (nn->jvms() != NULL) {
1629 st->print(" !jvms:");
1630 nn->jvms()->dump_spec(st);
1631 }
1632 }
1633 }
1634 if (suffix) st->print(suffix);
1635 _in_dump_cnt--;
1636 }
1637
1638 //------------------------------dump_req--------------------------------------
1639 void Node::dump_req(outputStream *st) const {
1640 // Dump the required input edges
1641 for (uint i = 0; i < req(); i++) { // For all required inputs
1642 Node* d = in(i);
1643 if (d == NULL) {
1644 st->print("_ ");
1645 } else if (NotANode(d)) {
1646 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1647 } else {
1648 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1649 }
1650 }
1651 }
1652
1653
1654 //------------------------------dump_prec-------------------------------------
1655 void Node::dump_prec(outputStream *st) const {
1656 // Dump the precedence edges
1657 int any_prec = 0;
1658 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1659 Node* p = in(i);
1660 if (p != NULL) {
1661 if (!any_prec++) st->print(" |");
1662 if (NotANode(p)) { st->print("NotANode "); continue; }
1663 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1664 }
1665 }
1666 }
1667
1668 //------------------------------dump_out--------------------------------------
1669 void Node::dump_out(outputStream *st) const {
1670 // Delimit the output edges
1671 st->print(" [[");
1672 // Dump the output edges
1673 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1674 Node* u = _out[i];
1675 if (u == NULL) {
1676 st->print("_ ");
1677 } else if (NotANode(u)) {
1678 st->print("NotANode ");
1679 } else {
1680 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1681 }
1682 }
1683 st->print("]] ");
1684 }
1685
1686 //------------------------------dump_nodes-------------------------------------
1687 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1688 Node* s = (Node*)start; // remove const
1689 if (NotANode(s)) return;
1690
1691 uint depth = (uint)ABS(d);
1692 int direction = d;
1693 Compile* C = Compile::current();
1694 GrowableArray <Node *> nstack(C->unique());
1695
1696 nstack.append(s);
1697 int begin = 0;
1698 int end = 0;
1699 for(uint i = 0; i < depth; i++) {
1700 end = nstack.length();
1701 for(int j = begin; j < end; j++) {
1702 Node* tp = nstack.at(j);
1703 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1704 for(uint k = 0; k < limit; k++) {
1705 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1706
1707 if (NotANode(n)) continue;
1708 // do not recurse through top or the root (would reach unrelated stuff)
1709 if (n->is_Root() || n->is_top()) continue;
1710 if (only_ctrl && !n->is_CFG()) continue;
1711
1712 bool on_stack = nstack.contains(n);
1713 if (!on_stack) {
1714 nstack.append(n);
1715 }
1716 }
1717 }
1718 begin = end;
1719 }
1720 end = nstack.length();
1721 if (direction > 0) {
1722 for(int j = end-1; j >= 0; j--) {
1723 nstack.at(j)->dump();
1724 }
1725 } else {
1726 for(int j = 0; j < end; j++) {
1727 nstack.at(j)->dump();
1728 }
1729 }
1730 }
1731
1732 //------------------------------dump-------------------------------------------
1733 void Node::dump(int d) const {
1734 dump_nodes(this, d, false);
1735 }
1736
1737 //------------------------------dump_ctrl--------------------------------------
1738 // Dump a Node's control history to depth
1739 void Node::dump_ctrl(int d) const {
1740 dump_nodes(this, d, true);
1741 }
1742
1743 // VERIFICATION CODE
1744 // For each input edge to a node (ie - for each Use-Def edge), verify that
1745 // there is a corresponding Def-Use edge.
1746 //------------------------------verify_edges-----------------------------------
1747 void Node::verify_edges(Unique_Node_List &visited) {
1748 uint i, j, idx;
1749 int cnt;
1750 Node *n;
1751
1752 // Recursive termination test
1753 if (visited.member(this)) return;
1754 visited.push(this);
1755
1756 // Walk over all input edges, checking for correspondence
1757 for( i = 0; i < len(); i++ ) {
1758 n = in(i);
1759 if (n != NULL && !n->is_top()) {
1760 // Count instances of (Node *)this
1761 cnt = 0;
1762 for (idx = 0; idx < n->_outcnt; idx++ ) {
1763 if (n->_out[idx] == (Node *)this) cnt++;
1764 }
1765 assert( cnt > 0,"Failed to find Def-Use edge." );
1766 // Check for duplicate edges
1767 // walk the input array downcounting the input edges to n
1768 for( j = 0; j < len(); j++ ) {
1769 if( in(j) == n ) cnt--;
1770 }
1771 assert( cnt == 0,"Mismatched edge count.");
1772 } else if (n == NULL) {
1773 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1774 } else {
1775 assert(n->is_top(), "sanity");
1776 // Nothing to check.
1777 }
1778 }
1779 // Recursive walk over all input edges
1780 for( i = 0; i < len(); i++ ) {
1781 n = in(i);
1782 if( n != NULL )
1783 in(i)->verify_edges(visited);
1784 }
1785 }
1786
1787 //------------------------------verify_recur-----------------------------------
1788 static const Node *unique_top = NULL;
1789
1790 void Node::verify_recur(const Node *n, int verify_depth,
1791 VectorSet &old_space, VectorSet &new_space) {
1792 if ( verify_depth == 0 ) return;
1793 if (verify_depth > 0) --verify_depth;
1794
1795 Compile* C = Compile::current();
1796
1797 // Contained in new_space or old_space?
1798 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1799 // Check for visited in the proper space. Numberings are not unique
1800 // across spaces so we need a separate VectorSet for each space.
1801 if( v->test_set(n->_idx) ) return;
1802
1803 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1804 if (C->cached_top_node() == NULL)
1805 C->set_cached_top_node((Node*)n);
1806 assert(C->cached_top_node() == n, "TOP node must be unique");
1807 }
1808
1809 for( uint i = 0; i < n->len(); i++ ) {
1810 Node *x = n->in(i);
1811 if (!x || x->is_top()) continue;
1812
1813 // Verify my input has a def-use edge to me
1814 if (true /*VerifyDefUse*/) {
1815 // Count use-def edges from n to x
1816 int cnt = 0;
1817 for( uint j = 0; j < n->len(); j++ )
1818 if( n->in(j) == x )
1819 cnt++;
1820 // Count def-use edges from x to n
1821 uint max = x->_outcnt;
1822 for( uint k = 0; k < max; k++ )
1823 if (x->_out[k] == n)
1824 cnt--;
1825 assert( cnt == 0, "mismatched def-use edge counts" );
1826 }
1827
1828 verify_recur(x, verify_depth, old_space, new_space);
1829 }
1830
1831 }
1832
1833 //------------------------------verify-----------------------------------------
1834 // Check Def-Use info for my subgraph
1835 void Node::verify() const {
1836 Compile* C = Compile::current();
1837 Node* old_top = C->cached_top_node();
1838 ResourceMark rm;
1839 ResourceArea *area = Thread::current()->resource_area();
1840 VectorSet old_space(area), new_space(area);
1841 verify_recur(this, -1, old_space, new_space);
1842 C->set_cached_top_node(old_top);
1843 }
1844 #endif
1845
1846
1847 //------------------------------walk-------------------------------------------
1848 // Graph walk, with both pre-order and post-order functions
1849 void Node::walk(NFunc pre, NFunc post, void *env) {
1850 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1851 walk_(pre, post, env, visited);
1852 }
1853
1854 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1855 if( visited.test_set(_idx) ) return;
1856 pre(*this,env); // Call the pre-order walk function
1857 for( uint i=0; i<_max; i++ )
1858 if( in(i) ) // Input exists and is not walked?
1859 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1860 post(*this,env); // Call the post-order walk function
1861 }
1862
1863 void Node::nop(Node &, void*) {}
1864
1865 //------------------------------Registers--------------------------------------
1866 // Do we Match on this edge index or not? Generally false for Control
1867 // and true for everything else. Weird for calls & returns.
1868 uint Node::match_edge(uint idx) const {
1869 return idx; // True for other than index 0 (control)
1870 }
1871
1872 // Register classes are defined for specific machines
1873 const RegMask &Node::out_RegMask() const {
1874 ShouldNotCallThis();
1875 return *(new RegMask());
1876 }
1877
1878 const RegMask &Node::in_RegMask(uint) const {
1879 ShouldNotCallThis();
1880 return *(new RegMask());
1881 }
1882
1883 //=============================================================================
1884 //-----------------------------------------------------------------------------
1885 void Node_Array::reset( Arena *new_arena ) {
1886 _a->Afree(_nodes,_max*sizeof(Node*));
1887 _max = 0;
1888 _nodes = NULL;
1889 _a = new_arena;
1890 }
1891
1892 //------------------------------clear------------------------------------------
1893 // Clear all entries in _nodes to NULL but keep storage
1894 void Node_Array::clear() {
1895 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1896 }
1897
1898 //-----------------------------------------------------------------------------
1899 void Node_Array::grow( uint i ) {
1900 if( !_max ) {
1901 _max = 1;
1902 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1903 _nodes[0] = NULL;
1904 }
1905 uint old = _max;
1906 while( i >= _max ) _max <<= 1; // Double to fit
1907 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1908 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1909 }
1910
1911 //-----------------------------------------------------------------------------
1912 void Node_Array::insert( uint i, Node *n ) {
1913 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1914 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1915 _nodes[i] = n;
1916 }
1917
1918 //-----------------------------------------------------------------------------
1919 void Node_Array::remove( uint i ) {
1920 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1921 _nodes[_max-1] = NULL;
1922 }
1923
1924 //-----------------------------------------------------------------------------
1925 void Node_Array::sort( C_sort_func_t func) {
1926 qsort( _nodes, _max, sizeof( Node* ), func );
1927 }
1928
1929 //-----------------------------------------------------------------------------
1930 void Node_Array::dump() const {
1931 #ifndef PRODUCT
1932 for( uint i = 0; i < _max; i++ ) {
1933 Node *nn = _nodes[i];
1934 if( nn != NULL ) {
1935 tty->print("%5d--> ",i); nn->dump();
1936 }
1937 }
1938 #endif
1939 }
1940
1941 //--------------------------is_iteratively_computed------------------------------
1942 // Operation appears to be iteratively computed (such as an induction variable)
1943 // It is possible for this operation to return false for a loop-varying
1944 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1945 bool Node::is_iteratively_computed() {
1946 if (ideal_reg()) { // does operation have a result register?
1947 for (uint i = 1; i < req(); i++) {
1948 Node* n = in(i);
1949 if (n != NULL && n->is_Phi()) {
1950 for (uint j = 1; j < n->req(); j++) {
1951 if (n->in(j) == this) {
1952 return true;
1953 }
1954 }
1955 }
1956 }
1957 }
1958 return false;
1959 }
1960
1961 //--------------------------find_similar------------------------------
1962 // Return a node with opcode "opc" and same inputs as "this" if one can
1963 // be found; Otherwise return NULL;
1964 Node* Node::find_similar(int opc) {
1965 if (req() >= 2) {
1966 Node* def = in(1);
1967 if (def && def->outcnt() >= 2) {
1968 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
1969 Node* use = def->fast_out(i);
1970 if (use->Opcode() == opc &&
1971 use->req() == req()) {
1972 uint j;
1973 for (j = 0; j < use->req(); j++) {
1974 if (use->in(j) != in(j)) {
1975 break;
1976 }
1977 }
1978 if (j == use->req()) {
1979 return use;
1980 }
1981 }
1982 }
1983 }
1984 }
1985 return NULL;
1986 }
1987
1988
1989 //--------------------------unique_ctrl_out------------------------------
1990 // Return the unique control out if only one. Null if none or more than one.
1991 Node* Node::unique_ctrl_out() {
1992 Node* found = NULL;
1993 for (uint i = 0; i < outcnt(); i++) {
1994 Node* use = raw_out(i);
1995 if (use->is_CFG() && use != this) {
1996 if (found != NULL) return NULL;
1997 found = use;
1998 }
1999 }
2000 return found;
2001 }
2002
2003 //=============================================================================
2004 //------------------------------yank-------------------------------------------
2005 // Find and remove
2006 void Node_List::yank( Node *n ) {
2007 uint i;
2008 for( i = 0; i < _cnt; i++ )
2009 if( _nodes[i] == n )
2010 break;
2011
2012 if( i < _cnt )
2013 _nodes[i] = _nodes[--_cnt];
2014 }
2015
2016 //------------------------------dump-------------------------------------------
2017 void Node_List::dump() const {
2018 #ifndef PRODUCT
2019 for( uint i = 0; i < _cnt; i++ )
2020 if( _nodes[i] ) {
2021 tty->print("%5d--> ",i);
2022 _nodes[i]->dump();
2023 }
2024 #endif
2025 }
2026
2027 //=============================================================================
2028 //------------------------------remove-----------------------------------------
2029 void Unique_Node_List::remove( Node *n ) {
2030 if( _in_worklist[n->_idx] ) {
2031 for( uint i = 0; i < size(); i++ )
2032 if( _nodes[i] == n ) {
2033 map(i,Node_List::pop());
2034 _in_worklist >>= n->_idx;
2035 return;
2036 }
2037 ShouldNotReachHere();
2038 }
2039 }
2040
2041 //-----------------------remove_useless_nodes----------------------------------
2042 // Remove useless nodes from worklist
2043 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2044
2045 for( uint i = 0; i < size(); ++i ) {
2046 Node *n = at(i);
2047 assert( n != NULL, "Did not expect null entries in worklist");
2048 if( ! useful.test(n->_idx) ) {
2049 _in_worklist >>= n->_idx;
2050 map(i,Node_List::pop());
2051 // Node *replacement = Node_List::pop();
2052 // if( i != size() ) { // Check if removing last entry
2053 // _nodes[i] = replacement;
2054 // }
2055 --i; // Visit popped node
2056 // If it was last entry, loop terminates since size() was also reduced
2057 }
2058 }
2059 }
2060
2061 //=============================================================================
2062 void Node_Stack::grow() {
2063 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2064 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2065 size_t max = old_max << 1; // max * 2
2066 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2067 _inode_max = _inodes + max;
2068 _inode_top = _inodes + old_top; // restore _top
2069 }
2070
2071 // Node_Stack is used to map nodes.
2072 Node* Node_Stack::find(uint idx) const {
2073 uint sz = size();
2074 for (uint i=0; i < sz; i++) {
2075 if (idx == index_at(i) )
2076 return node_at(i);
2077 }
2078 return NULL;
2079 }
2080
2081 //=============================================================================
2082 uint TypeNode::size_of() const { return sizeof(*this); }
2083 #ifndef PRODUCT
2084 void TypeNode::dump_spec(outputStream *st) const {
2085 if( !Verbose && !WizardMode ) {
2086 // standard dump does this in Verbose and WizardMode
2087 st->print(" #"); _type->dump_on(st);
2088 }
2089 }
2090 #endif
2091 uint TypeNode::hash() const {
2092 return Node::hash() + _type->hash();
2093 }
2094 uint TypeNode::cmp( const Node &n ) const
2095 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2096 const Type *TypeNode::bottom_type() const { return _type; }
2097 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2098
2099 //------------------------------ideal_reg--------------------------------------
2100 uint TypeNode::ideal_reg() const {
2101 return Matcher::base2reg[_type->base()];
2102 }