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 thos 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)MaxNodeLimit, "Node limit exceeded");
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
497 n->set_idx(compile->next_unique()); // Get new unique index as well
498 debug_only( n->verify_construction() );
499 NOT_PRODUCT(nodes_created++);
500 // Do not patch over the debug_idx of a clone, because it makes it
501 // impossible to break on the clone's moment of creation.
502 //debug_only( n->set_debug_idx( debug_idx() ) );
503
504 compile->copy_node_notes_to(n, (Node*) this);
505
506 // MachNode clone
507 uint nopnds;
508 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
509 MachNode *mach = n->as_Mach();
510 MachNode *mthis = this->as_Mach();
511 // Get address of _opnd_array.
512 // It should be the same offset since it is the clone of this node.
513 MachOper **from = mthis->_opnds;
514 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
515 pointer_delta((const void*)from,
516 (const void*)(&mthis->_opnds), 1));
517 mach->_opnds = to;
518 for ( uint i = 0; i < nopnds; ++i ) {
519 to[i] = from[i]->clone(compile);
520 }
521 }
522 // cloning CallNode may need to clone JVMState
523 if (n->is_Call()) {
524 CallNode *call = n->as_Call();
525 call->clone_jvms();
526 }
527 return n; // Return the clone
528 }
529
530 //---------------------------setup_is_top--------------------------------------
531 // Call this when changing the top node, to reassert the invariants
532 // required by Node::is_top. See Compile::set_cached_top_node.
533 void Node::setup_is_top() {
534 if (this == (Node*)Compile::current()->top()) {
535 // This node has just become top. Kill its out array.
536 _outcnt = _outmax = 0;
537 _out = NULL; // marker value for top
538 assert(is_top(), "must be top");
539 } else {
540 if (_out == NULL) _out = NO_OUT_ARRAY;
541 assert(!is_top(), "must not be top");
542 }
543 }
544
545
546 //------------------------------~Node------------------------------------------
547 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
548 extern int reclaim_idx ;
549 extern int reclaim_in ;
550 extern int reclaim_node;
551 void Node::destruct() {
552 // Eagerly reclaim unique Node numberings
553 Compile* compile = Compile::current();
554 if ((uint)_idx+1 == compile->unique()) {
555 compile->set_unique(compile->unique()-1);
556 #ifdef ASSERT
557 reclaim_idx++;
558 #endif
559 }
560 // Clear debug info:
561 Node_Notes* nn = compile->node_notes_at(_idx);
562 if (nn != NULL) nn->clear();
563 // Walk the input array, freeing the corresponding output edges
564 _cnt = _max; // forget req/prec distinction
565 uint i;
566 for( i = 0; i < _max; i++ ) {
567 set_req(i, NULL);
568 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
569 }
570 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
571 // See if the input array was allocated just prior to the object
572 int edge_size = _max*sizeof(void*);
573 int out_edge_size = _outmax*sizeof(void*);
574 char *edge_end = ((char*)_in) + edge_size;
575 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
576 char *out_edge_end = out_array + out_edge_size;
577 int node_size = size_of();
578
579 // Free the output edge array
580 if (out_edge_size > 0) {
581 #ifdef ASSERT
582 if( out_edge_end == compile->node_arena()->hwm() )
583 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
584 #endif
585 compile->node_arena()->Afree(out_array, out_edge_size);
586 }
587
588 // Free the input edge array and the node itself
589 if( edge_end == (char*)this ) {
590 #ifdef ASSERT
591 if( edge_end+node_size == compile->node_arena()->hwm() ) {
592 reclaim_in += edge_size;
593 reclaim_node+= node_size;
594 }
595 #else
596 // It was; free the input array and object all in one hit
597 compile->node_arena()->Afree(_in,edge_size+node_size);
598 #endif
599 } else {
600
601 // Free just the input array
602 #ifdef ASSERT
603 if( edge_end == compile->node_arena()->hwm() )
604 reclaim_in += edge_size;
605 #endif
606 compile->node_arena()->Afree(_in,edge_size);
607
608 // Free just the object
609 #ifdef ASSERT
610 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
611 reclaim_node+= node_size;
612 #else
613 compile->node_arena()->Afree(this,node_size);
614 #endif
615 }
616 if (is_macro()) {
617 compile->remove_macro_node(this);
618 }
619 #ifdef ASSERT
620 // We will not actually delete the storage, but we'll make the node unusable.
621 *(address*)this = badAddress; // smash the C++ vtbl, probably
622 _in = _out = (Node**) badAddress;
623 _max = _cnt = _outmax = _outcnt = 0;
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 //------------------------------add_req----------------------------------------
693 // Add a new required input at the end
694 void Node::add_req( Node *n ) {
695 assert( is_not_dead(n), "can not use dead node");
696
697 // Look to see if I can move precedence down one without reallocating
698 if( (_cnt >= _max) || (in(_max-1) != NULL) )
699 grow( _max+1 );
700
701 // Find a precedence edge to move
702 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
703 uint i;
704 for( i=_cnt; i<_max; i++ )
705 if( in(i) == NULL ) // Find the NULL at end of prec edge list
706 break; // There must be one, since we grew the array
707 _in[i] = in(_cnt); // Move prec over, making space for req edge
708 }
709 _in[_cnt++] = n; // Stuff over old prec edge
710 if (n != NULL) n->add_out((Node *)this);
711 }
712
713 //---------------------------add_req_batch-------------------------------------
714 // Add a new required input at the end
715 void Node::add_req_batch( Node *n, uint m ) {
716 assert( is_not_dead(n), "can not use dead node");
717 // check various edge cases
718 if ((int)m <= 1) {
719 assert((int)m >= 0, "oob");
720 if (m != 0) add_req(n);
721 return;
722 }
723
724 // Look to see if I can move precedence down one without reallocating
725 if( (_cnt+m) > _max || _in[_max-m] )
726 grow( _max+m );
727
728 // Find a precedence edge to move
729 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
730 uint i;
731 for( i=_cnt; i<_max; i++ )
732 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
733 break; // There must be one, since we grew the array
734 // Slide all the precs over by m positions (assume #prec << m).
735 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
736 }
737
738 // Stuff over the old prec edges
739 for(uint i=0; i<m; i++ ) {
740 _in[_cnt++] = n;
741 }
742
743 // Insert multiple out edges on the node.
744 if (n != NULL && !n->is_top()) {
745 for(uint i=0; i<m; i++ ) {
746 n->add_out((Node *)this);
747 }
748 }
749 }
750
751 //------------------------------del_req----------------------------------------
752 // Delete the required edge and compact the edge array
753 void Node::del_req( uint idx ) {
754 assert( idx < _cnt, "oob");
755 assert( !VerifyHashTableKeys || _hash_lock == 0,
756 "remove node from hash table before modifying it");
757 // First remove corresponding def-use edge
758 Node *n = in(idx);
759 if (n != NULL) n->del_out((Node *)this);
760 _in[idx] = in(--_cnt); // Compact the array
761 _in[_cnt] = NULL; // NULL out emptied slot
762 }
763
764 //------------------------------ins_req----------------------------------------
765 // Insert a new required input at the end
766 void Node::ins_req( uint idx, Node *n ) {
767 assert( is_not_dead(n), "can not use dead node");
768 add_req(NULL); // Make space
769 assert( idx < _max, "Must have allocated enough space");
770 // Slide over
771 if(_cnt-idx-1 > 0) {
772 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
773 }
774 _in[idx] = n; // Stuff over old required edge
775 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
776 }
777
778 //-----------------------------find_edge---------------------------------------
779 int Node::find_edge(Node* n) {
780 for (uint i = 0; i < len(); i++) {
781 if (_in[i] == n) return i;
782 }
783 return -1;
784 }
785
786 //----------------------------replace_edge-------------------------------------
787 int Node::replace_edge(Node* old, Node* neww) {
788 if (old == neww) return 0; // nothing to do
789 uint nrep = 0;
790 for (uint i = 0; i < len(); i++) {
791 if (in(i) == old) {
792 if (i < req())
793 set_req(i, neww);
794 else
795 set_prec(i, neww);
796 nrep++;
797 }
798 }
799 return nrep;
800 }
801
802 //-------------------------disconnect_inputs-----------------------------------
803 // NULL out all inputs to eliminate incoming Def-Use edges.
804 // Return the number of edges between 'n' and 'this'
805 int Node::disconnect_inputs(Node *n) {
806 int edges_to_n = 0;
807
808 uint cnt = req();
809 for( uint i = 0; i < cnt; ++i ) {
810 if( in(i) == 0 ) continue;
811 if( in(i) == n ) ++edges_to_n;
812 set_req(i, NULL);
813 }
814 // Remove precedence edges if any exist
815 // Note: Safepoints may have precedence edges, even during parsing
816 if( (req() != len()) && (in(req()) != NULL) ) {
817 uint max = len();
818 for( uint i = 0; i < max; ++i ) {
819 if( in(i) == 0 ) continue;
820 if( in(i) == n ) ++edges_to_n;
821 set_prec(i, NULL);
822 }
823 }
824
825 // Node::destruct requires all out edges be deleted first
826 // debug_only(destruct();) // no reuse benefit expected
827 return edges_to_n;
828 }
829
830 //-----------------------------uncast---------------------------------------
831 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
832 // Strip away casting. (It is depth-limited.)
833 Node* Node::uncast() const {
834 // Should be inline:
835 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
836 if (is_ConstraintCast() || is_CheckCastPP())
837 return uncast_helper(this);
838 else
839 return (Node*) this;
840 }
841
842 //---------------------------uncast_helper-------------------------------------
843 Node* Node::uncast_helper(const Node* p) {
844 #ifdef ASSERT
845 uint depth_count = 0;
846 const Node* orig_p = p;
847 #endif
848
849 while (true) {
850 #ifdef ASSERT
851 if (depth_count >= K) {
852 orig_p->dump(4);
853 if (p != orig_p)
854 p->dump(1);
855 }
856 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
857 #endif
858 if (p == NULL || p->req() != 2) {
859 break;
860 } else if (p->is_ConstraintCast()) {
861 p = p->in(1);
862 } else if (p->is_CheckCastPP()) {
863 p = p->in(1);
864 } else {
865 break;
866 }
867 }
868 return (Node*) p;
869 }
870
871 //------------------------------add_prec---------------------------------------
872 // Add a new precedence input. Precedence inputs are unordered, with
873 // duplicates removed and NULLs packed down at the end.
874 void Node::add_prec( Node *n ) {
875 assert( is_not_dead(n), "can not use dead node");
876
877 // Check for NULL at end
878 if( _cnt >= _max || in(_max-1) )
879 grow( _max+1 );
880
881 // Find a precedence edge to move
882 uint i = _cnt;
883 while( in(i) != NULL ) i++;
884 _in[i] = n; // Stuff prec edge over NULL
885 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
886 }
887
888 //------------------------------rm_prec----------------------------------------
889 // Remove a precedence input. Precedence inputs are unordered, with
890 // duplicates removed and NULLs packed down at the end.
891 void Node::rm_prec( uint j ) {
892
893 // Find end of precedence list to pack NULLs
894 uint i;
895 for( i=j; i<_max; i++ )
896 if( !_in[i] ) // Find the NULL at end of prec edge list
897 break;
898 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
899 _in[j] = _in[--i]; // Move last element over removed guy
900 _in[i] = NULL; // NULL out last element
901 }
902
903 //------------------------------size_of----------------------------------------
904 uint Node::size_of() const { return sizeof(*this); }
905
906 //------------------------------ideal_reg--------------------------------------
907 uint Node::ideal_reg() const { return 0; }
908
909 //------------------------------jvms-------------------------------------------
910 JVMState* Node::jvms() const { return NULL; }
911
912 #ifdef ASSERT
913 //------------------------------jvms-------------------------------------------
914 bool Node::verify_jvms(const JVMState* using_jvms) const {
915 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
916 if (jvms == using_jvms) return true;
917 }
918 return false;
919 }
920
921 //------------------------------init_NodeProperty------------------------------
922 void Node::init_NodeProperty() {
923 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
924 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
925 }
926 #endif
927
928 //------------------------------format-----------------------------------------
929 // Print as assembly
930 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
931 //------------------------------emit-------------------------------------------
932 // Emit bytes starting at parameter 'ptr'.
933 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
934 //------------------------------size-------------------------------------------
935 // Size of instruction in bytes
936 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
937
938 //------------------------------CFG Construction-------------------------------
939 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
940 // Goto and Return.
941 const Node *Node::is_block_proj() const { return 0; }
942
943 // Minimum guaranteed type
944 const Type *Node::bottom_type() const { return Type::BOTTOM; }
945
946
947 //------------------------------raise_bottom_type------------------------------
948 // Get the worst-case Type output for this Node.
949 void Node::raise_bottom_type(const Type* new_type) {
950 if (is_Type()) {
951 TypeNode *n = this->as_Type();
952 if (VerifyAliases) {
953 assert(new_type->higher_equal(n->type()), "new type must refine old type");
954 }
955 n->set_type(new_type);
956 } else if (is_Load()) {
957 LoadNode *n = this->as_Load();
958 if (VerifyAliases) {
959 assert(new_type->higher_equal(n->type()), "new type must refine old type");
960 }
961 n->set_type(new_type);
962 }
963 }
964
965 //------------------------------Identity---------------------------------------
966 // Return a node that the given node is equivalent to.
967 Node *Node::Identity( PhaseTransform * ) {
968 return this; // Default to no identities
969 }
970
971 //------------------------------Value------------------------------------------
972 // Compute a new Type for a node using the Type of the inputs.
973 const Type *Node::Value( PhaseTransform * ) const {
974 return bottom_type(); // Default to worst-case Type
975 }
976
977 //------------------------------Ideal------------------------------------------
978 //
979 // 'Idealize' the graph rooted at this Node.
980 //
981 // In order to be efficient and flexible there are some subtle invariants
982 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
983 // these invariants, although its too slow to have on by default. If you are
984 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
985 //
986 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
987 // pointer. If ANY change is made, it must return the root of the reshaped
988 // graph - even if the root is the same Node. Example: swapping the inputs
989 // to an AddINode gives the same answer and same root, but you still have to
990 // return the 'this' pointer instead of NULL.
991 //
992 // You cannot return an OLD Node, except for the 'this' pointer. Use the
993 // Identity call to return an old Node; basically if Identity can find
994 // another Node have the Ideal call make no change and return NULL.
995 // Example: AddINode::Ideal must check for add of zero; in this case it
996 // returns NULL instead of doing any graph reshaping.
997 //
998 // You cannot modify any old Nodes except for the 'this' pointer. Due to
999 // sharing there may be other users of the old Nodes relying on their current
1000 // semantics. Modifying them will break the other users.
1001 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1002 // "X+3" unchanged in case it is shared.
1003 //
1004 // If you modify the 'this' pointer's inputs, you should use
1005 // 'set_req'. If you are making a new Node (either as the new root or
1006 // some new internal piece) you may use 'init_req' to set the initial
1007 // value. You can make a new Node with either 'new' or 'clone'. In
1008 // either case, def-use info is correctly maintained.
1009 //
1010 // Example: reshape "(X+3)+4" into "X+7":
1011 // set_req(1, in(1)->in(1));
1012 // set_req(2, phase->intcon(7));
1013 // return this;
1014 // Example: reshape "X*4" into "X<<2"
1015 // return new (C) LShiftINode(in(1), phase->intcon(2));
1016 //
1017 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1018 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1019 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1020 // return new (C) AddINode(shift, in(1));
1021 //
1022 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1023 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1024 // The Right Thing with def-use info.
1025 //
1026 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1027 // graph uses the 'this' Node it must be the root. If you want a Node with
1028 // the same Opcode as the 'this' pointer use 'clone'.
1029 //
1030 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1031 return NULL; // Default to being Ideal already
1032 }
1033
1034 // Some nodes have specific Ideal subgraph transformations only if they are
1035 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1036 // for the transformations to happen.
1037 bool Node::has_special_unique_user() const {
1038 assert(outcnt() == 1, "match only for unique out");
1039 Node* n = unique_out();
1040 int op = Opcode();
1041 if( this->is_Store() ) {
1042 // Condition for back-to-back stores folding.
1043 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1044 } else if( op == Op_AddL ) {
1045 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1046 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1047 } else if( op == Op_SubI || op == Op_SubL ) {
1048 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1049 return n->Opcode() == op && n->in(2) == this;
1050 }
1051 return false;
1052 };
1053
1054 //--------------------------find_exact_control---------------------------------
1055 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1056 Node* Node::find_exact_control(Node* ctrl) {
1057 if (ctrl == NULL && this->is_Region())
1058 ctrl = this->as_Region()->is_copy();
1059
1060 if (ctrl != NULL && ctrl->is_CatchProj()) {
1061 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1062 ctrl = ctrl->in(0);
1063 if (ctrl != NULL && !ctrl->is_top())
1064 ctrl = ctrl->in(0);
1065 }
1066
1067 if (ctrl != NULL && ctrl->is_Proj())
1068 ctrl = ctrl->in(0);
1069
1070 return ctrl;
1071 }
1072
1073 //--------------------------dominates------------------------------------------
1074 // Helper function for MemNode::all_controls_dominate().
1075 // Check if 'this' control node dominates or equal to 'sub' control node.
1076 // We already know that if any path back to Root or Start reaches 'this',
1077 // then all paths so, so this is a simple search for one example,
1078 // not an exhaustive search for a counterexample.
1079 bool Node::dominates(Node* sub, Node_List &nlist) {
1080 assert(this->is_CFG(), "expecting control");
1081 assert(sub != NULL && sub->is_CFG(), "expecting control");
1082
1083 // detect dead cycle without regions
1084 int iterations_without_region_limit = DominatorSearchLimit;
1085
1086 Node* orig_sub = sub;
1087 Node* dom = this;
1088 bool met_dom = false;
1089 nlist.clear();
1090
1091 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1092 // After seeing 'dom', continue up to Root or Start.
1093 // If we hit a region (backward split point), it may be a loop head.
1094 // Keep going through one of the region's inputs. If we reach the
1095 // same region again, go through a different input. Eventually we
1096 // will either exit through the loop head, or give up.
1097 // (If we get confused, break out and return a conservative 'false'.)
1098 while (sub != NULL) {
1099 if (sub->is_top()) break; // Conservative answer for dead code.
1100 if (sub == dom) {
1101 if (nlist.size() == 0) {
1102 // No Region nodes except loops were visited before and the EntryControl
1103 // path was taken for loops: it did not walk in a cycle.
1104 return true;
1105 } else if (met_dom) {
1106 break; // already met before: walk in a cycle
1107 } else {
1108 // Region nodes were visited. Continue walk up to Start or Root
1109 // to make sure that it did not walk in a cycle.
1110 met_dom = true; // first time meet
1111 iterations_without_region_limit = DominatorSearchLimit; // Reset
1112 }
1113 }
1114 if (sub->is_Start() || sub->is_Root()) {
1115 // Success if we met 'dom' along a path to Start or Root.
1116 // We assume there are no alternative paths that avoid 'dom'.
1117 // (This assumption is up to the caller to ensure!)
1118 return met_dom;
1119 }
1120 Node* up = sub->in(0);
1121 // Normalize simple pass-through regions and projections:
1122 up = sub->find_exact_control(up);
1123 // If sub == up, we found a self-loop. Try to push past it.
1124 if (sub == up && sub->is_Loop()) {
1125 // Take loop entry path on the way up to 'dom'.
1126 up = sub->in(1); // in(LoopNode::EntryControl);
1127 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1128 // Always take in(1) path on the way up to 'dom' for clone regions
1129 // (with only one input) or regions which merge > 2 paths
1130 // (usually used to merge fast/slow paths).
1131 up = sub->in(1);
1132 } else if (sub == up && sub->is_Region()) {
1133 // Try both paths for Regions with 2 input paths (it may be a loop head).
1134 // It could give conservative 'false' answer without information
1135 // which region's input is the entry path.
1136 iterations_without_region_limit = DominatorSearchLimit; // Reset
1137
1138 bool region_was_visited_before = false;
1139 // Was this Region node visited before?
1140 // If so, we have reached it because we accidentally took a
1141 // loop-back edge from 'sub' back into the body of the loop,
1142 // and worked our way up again to the loop header 'sub'.
1143 // So, take the first unexplored path on the way up to 'dom'.
1144 for (int j = nlist.size() - 1; j >= 0; j--) {
1145 intptr_t ni = (intptr_t)nlist.at(j);
1146 Node* visited = (Node*)(ni & ~1);
1147 bool visited_twice_already = ((ni & 1) != 0);
1148 if (visited == sub) {
1149 if (visited_twice_already) {
1150 // Visited 2 paths, but still stuck in loop body. Give up.
1151 return false;
1152 }
1153 // The Region node was visited before only once.
1154 // (We will repush with the low bit set, below.)
1155 nlist.remove(j);
1156 // We will find a new edge and re-insert.
1157 region_was_visited_before = true;
1158 break;
1159 }
1160 }
1161
1162 // Find an incoming edge which has not been seen yet; walk through it.
1163 assert(up == sub, "");
1164 uint skip = region_was_visited_before ? 1 : 0;
1165 for (uint i = 1; i < sub->req(); i++) {
1166 Node* in = sub->in(i);
1167 if (in != NULL && !in->is_top() && in != sub) {
1168 if (skip == 0) {
1169 up = in;
1170 break;
1171 }
1172 --skip; // skip this nontrivial input
1173 }
1174 }
1175
1176 // Set 0 bit to indicate that both paths were taken.
1177 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1178 }
1179
1180 if (up == sub) {
1181 break; // some kind of tight cycle
1182 }
1183 if (up == orig_sub && met_dom) {
1184 // returned back after visiting 'dom'
1185 break; // some kind of cycle
1186 }
1187 if (--iterations_without_region_limit < 0) {
1188 break; // dead cycle
1189 }
1190 sub = up;
1191 }
1192
1193 // Did not meet Root or Start node in pred. chain.
1194 // Conservative answer for dead code.
1195 return false;
1196 }
1197
1198 //------------------------------remove_dead_region-----------------------------
1199 // This control node is dead. Follow the subgraph below it making everything
1200 // using it dead as well. This will happen normally via the usual IterGVN
1201 // worklist but this call is more efficient. Do not update use-def info
1202 // inside the dead region, just at the borders.
1203 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1204 // Con's are a popular node to re-hit in the hash table again.
1205 if( dead->is_Con() ) return;
1206
1207 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1208 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1209 Node_List nstack(Thread::current()->resource_area());
1210
1211 Node *top = igvn->C->top();
1212 nstack.push(dead);
1213
1214 while (nstack.size() > 0) {
1215 dead = nstack.pop();
1216 if (dead->outcnt() > 0) {
1217 // Keep dead node on stack until all uses are processed.
1218 nstack.push(dead);
1219 // For all Users of the Dead... ;-)
1220 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1221 Node* use = dead->last_out(k);
1222 igvn->hash_delete(use); // Yank from hash table prior to mod
1223 if (use->in(0) == dead) { // Found another dead node
1224 assert (!use->is_Con(), "Control for Con node should be Root node.");
1225 use->set_req(0, top); // Cut dead edge to prevent processing
1226 nstack.push(use); // the dead node again.
1227 } else { // Else found a not-dead user
1228 for (uint j = 1; j < use->req(); j++) {
1229 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1230 use->set_req(j, top);
1231 }
1232 }
1233 igvn->_worklist.push(use);
1234 }
1235 // Refresh the iterator, since any number of kills might have happened.
1236 k = dead->last_outs(kmin);
1237 }
1238 } else { // (dead->outcnt() == 0)
1239 // Done with outputs.
1240 igvn->hash_delete(dead);
1241 igvn->_worklist.remove(dead);
1242 igvn->set_type(dead, Type::TOP);
1243 if (dead->is_macro()) {
1244 igvn->C->remove_macro_node(dead);
1245 }
1246 // Kill all inputs to the dead guy
1247 for (uint i=0; i < dead->req(); i++) {
1248 Node *n = dead->in(i); // Get input to dead guy
1249 if (n != NULL && !n->is_top()) { // Input is valid?
1250 dead->set_req(i, top); // Smash input away
1251 if (n->outcnt() == 0) { // Input also goes dead?
1252 if (!n->is_Con())
1253 nstack.push(n); // Clear it out as well
1254 } else if (n->outcnt() == 1 &&
1255 n->has_special_unique_user()) {
1256 igvn->add_users_to_worklist( n );
1257 } else if (n->outcnt() <= 2 && n->is_Store()) {
1258 // Push store's uses on worklist to enable folding optimization for
1259 // store/store and store/load to the same address.
1260 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1261 // and remove_globally_dead_node().
1262 igvn->add_users_to_worklist( n );
1263 }
1264 }
1265 }
1266 } // (dead->outcnt() == 0)
1267 } // while (nstack.size() > 0) for outputs
1268 return;
1269 }
1270
1271 //------------------------------remove_dead_region-----------------------------
1272 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1273 Node *n = in(0);
1274 if( !n ) return false;
1275 // Lost control into this guy? I.e., it became unreachable?
1276 // Aggressively kill all unreachable code.
1277 if (can_reshape && n->is_top()) {
1278 kill_dead_code(this, phase->is_IterGVN());
1279 return false; // Node is dead.
1280 }
1281
1282 if( n->is_Region() && n->as_Region()->is_copy() ) {
1283 Node *m = n->nonnull_req();
1284 set_req(0, m);
1285 return true;
1286 }
1287 return false;
1288 }
1289
1290 //------------------------------Ideal_DU_postCCP-------------------------------
1291 // Idealize graph, using DU info. Must clone result into new-space
1292 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1293 return NULL; // Default to no change
1294 }
1295
1296 //------------------------------hash-------------------------------------------
1297 // Hash function over Nodes.
1298 uint Node::hash() const {
1299 uint sum = 0;
1300 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1301 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1302 return (sum>>2) + _cnt + Opcode();
1303 }
1304
1305 //------------------------------cmp--------------------------------------------
1306 // Compare special parts of simple Nodes
1307 uint Node::cmp( const Node &n ) const {
1308 return 1; // Must be same
1309 }
1310
1311 //------------------------------rematerialize-----------------------------------
1312 // Should we clone rather than spill this instruction?
1313 bool Node::rematerialize() const {
1314 if ( is_Mach() )
1315 return this->as_Mach()->rematerialize();
1316 else
1317 return (_flags & Flag_rematerialize) != 0;
1318 }
1319
1320 //------------------------------needs_anti_dependence_check---------------------
1321 // Nodes which use memory without consuming it, hence need antidependences.
1322 bool Node::needs_anti_dependence_check() const {
1323 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1324 return false;
1325 else
1326 return in(1)->bottom_type()->has_memory();
1327 }
1328
1329
1330 // Get an integer constant from a ConNode (or CastIINode).
1331 // Return a default value if there is no apparent constant here.
1332 const TypeInt* Node::find_int_type() const {
1333 if (this->is_Type()) {
1334 return this->as_Type()->type()->isa_int();
1335 } else if (this->is_Con()) {
1336 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1337 return this->bottom_type()->isa_int();
1338 }
1339 return NULL;
1340 }
1341
1342 // Get a pointer constant from a ConstNode.
1343 // Returns the constant if it is a pointer ConstNode
1344 intptr_t Node::get_ptr() const {
1345 assert( Opcode() == Op_ConP, "" );
1346 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1347 }
1348
1349 // Get a narrow oop constant from a ConNNode.
1350 intptr_t Node::get_narrowcon() const {
1351 assert( Opcode() == Op_ConN, "" );
1352 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1353 }
1354
1355 // Get a long constant from a ConNode.
1356 // Return a default value if there is no apparent constant here.
1357 const TypeLong* Node::find_long_type() const {
1358 if (this->is_Type()) {
1359 return this->as_Type()->type()->isa_long();
1360 } else if (this->is_Con()) {
1361 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1362 return this->bottom_type()->isa_long();
1363 }
1364 return NULL;
1365 }
1366
1367 // Get a double constant from a ConstNode.
1368 // Returns the constant if it is a double ConstNode
1369 jdouble Node::getd() const {
1370 assert( Opcode() == Op_ConD, "" );
1371 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1372 }
1373
1374 // Get a float constant from a ConstNode.
1375 // Returns the constant if it is a float ConstNode
1376 jfloat Node::getf() const {
1377 assert( Opcode() == Op_ConF, "" );
1378 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1379 }
1380
1381 #ifndef PRODUCT
1382
1383 //----------------------------NotANode----------------------------------------
1384 // Used in debugging code to avoid walking across dead or uninitialized edges.
1385 static inline bool NotANode(const Node* n) {
1386 if (n == NULL) return true;
1387 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1388 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1389 return false;
1390 }
1391
1392
1393 //------------------------------find------------------------------------------
1394 // Find a neighbor of this Node with the given _idx
1395 // If idx is negative, find its absolute value, following both _in and _out.
1396 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1397 VectorSet* old_space, VectorSet* new_space ) {
1398 int node_idx = (idx >= 0) ? idx : -idx;
1399 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1400 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1401 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1402 if( v->test(n->_idx) ) return;
1403 if( (int)n->_idx == node_idx
1404 debug_only(|| n->debug_idx() == node_idx) ) {
1405 if (result != NULL)
1406 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1407 (uintptr_t)result, (uintptr_t)n, node_idx);
1408 result = n;
1409 }
1410 v->set(n->_idx);
1411 for( uint i=0; i<n->len(); i++ ) {
1412 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1413 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1414 }
1415 // Search along forward edges also:
1416 if (idx < 0 && !only_ctrl) {
1417 for( uint j=0; j<n->outcnt(); j++ ) {
1418 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1419 }
1420 }
1421 #ifdef ASSERT
1422 // Search along debug_orig edges last, checking for cycles
1423 Node* orig = n->debug_orig();
1424 if (orig != NULL) {
1425 do {
1426 if (NotANode(orig)) break;
1427 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1428 orig = orig->debug_orig();
1429 } while (orig != NULL && orig != n->debug_orig());
1430 }
1431 #endif //ASSERT
1432 }
1433
1434 // call this from debugger:
1435 Node* find_node(Node* n, int idx) {
1436 return n->find(idx);
1437 }
1438
1439 //------------------------------find-------------------------------------------
1440 Node* Node::find(int idx) const {
1441 ResourceArea *area = Thread::current()->resource_area();
1442 VectorSet old_space(area), new_space(area);
1443 Node* result = NULL;
1444 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1445 return result;
1446 }
1447
1448 //------------------------------find_ctrl--------------------------------------
1449 // Find an ancestor to this node in the control history with given _idx
1450 Node* Node::find_ctrl(int idx) const {
1451 ResourceArea *area = Thread::current()->resource_area();
1452 VectorSet old_space(area), new_space(area);
1453 Node* result = NULL;
1454 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1455 return result;
1456 }
1457 #endif
1458
1459
1460
1461 #ifndef PRODUCT
1462 int Node::_in_dump_cnt = 0;
1463
1464 // -----------------------------Name-------------------------------------------
1465 extern const char *NodeClassNames[];
1466 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1467
1468 static bool is_disconnected(const Node* n) {
1469 for (uint i = 0; i < n->req(); i++) {
1470 if (n->in(i) != NULL) return false;
1471 }
1472 return true;
1473 }
1474
1475 #ifdef ASSERT
1476 static void dump_orig(Node* orig) {
1477 Compile* C = Compile::current();
1478 if (NotANode(orig)) orig = NULL;
1479 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1480 if (orig == NULL) return;
1481 tty->print(" !orig=");
1482 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1483 if (NotANode(fast)) fast = NULL;
1484 while (orig != NULL) {
1485 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1486 if (discon) tty->print("[");
1487 if (!Compile::current()->node_arena()->contains(orig))
1488 tty->print("o");
1489 tty->print("%d", orig->_idx);
1490 if (discon) tty->print("]");
1491 orig = orig->debug_orig();
1492 if (NotANode(orig)) orig = NULL;
1493 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1494 if (orig != NULL) tty->print(",");
1495 if (fast != NULL) {
1496 // Step fast twice for each single step of orig:
1497 fast = fast->debug_orig();
1498 if (NotANode(fast)) fast = NULL;
1499 if (fast != NULL && fast != orig) {
1500 fast = fast->debug_orig();
1501 if (NotANode(fast)) fast = NULL;
1502 }
1503 if (fast == orig) {
1504 tty->print("...");
1505 break;
1506 }
1507 }
1508 }
1509 }
1510
1511 void Node::set_debug_orig(Node* orig) {
1512 _debug_orig = orig;
1513 if (BreakAtNode == 0) return;
1514 if (NotANode(orig)) orig = NULL;
1515 int trip = 10;
1516 while (orig != NULL) {
1517 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1518 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1519 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1520 BREAKPOINT;
1521 }
1522 orig = orig->debug_orig();
1523 if (NotANode(orig)) orig = NULL;
1524 if (trip-- <= 0) break;
1525 }
1526 }
1527 #endif //ASSERT
1528
1529 //------------------------------dump------------------------------------------
1530 // Dump a Node
1531 void Node::dump() const {
1532 Compile* C = Compile::current();
1533 bool is_new = C->node_arena()->contains(this);
1534 _in_dump_cnt++;
1535 tty->print("%c%d\t%s\t=== ",
1536 is_new ? ' ' : 'o', _idx, Name());
1537
1538 // Dump the required and precedence inputs
1539 dump_req();
1540 dump_prec();
1541 // Dump the outputs
1542 dump_out();
1543
1544 if (is_disconnected(this)) {
1545 #ifdef ASSERT
1546 tty->print(" [%d]",debug_idx());
1547 dump_orig(debug_orig());
1548 #endif
1549 tty->cr();
1550 _in_dump_cnt--;
1551 return; // don't process dead nodes
1552 }
1553
1554 // Dump node-specific info
1555 dump_spec(tty);
1556 #ifdef ASSERT
1557 // Dump the non-reset _debug_idx
1558 if( Verbose && WizardMode ) {
1559 tty->print(" [%d]",debug_idx());
1560 }
1561 #endif
1562
1563 const Type *t = bottom_type();
1564
1565 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1566 const TypeInstPtr *toop = t->isa_instptr();
1567 const TypeKlassPtr *tkls = t->isa_klassptr();
1568 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1569 if( klass && klass->is_loaded() && klass->is_interface() ) {
1570 tty->print(" Interface:");
1571 } else if( toop ) {
1572 tty->print(" Oop:");
1573 } else if( tkls ) {
1574 tty->print(" Klass:");
1575 }
1576 t->dump();
1577 } else if( t == Type::MEMORY ) {
1578 tty->print(" Memory:");
1579 MemNode::dump_adr_type(this, adr_type(), tty);
1580 } else if( Verbose || WizardMode ) {
1581 tty->print(" Type:");
1582 if( t ) {
1583 t->dump();
1584 } else {
1585 tty->print("no type");
1586 }
1587 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1588 // Dump MachSpillcopy vector type.
1589 t->dump();
1590 }
1591 if (is_new) {
1592 debug_only(dump_orig(debug_orig()));
1593 Node_Notes* nn = C->node_notes_at(_idx);
1594 if (nn != NULL && !nn->is_clear()) {
1595 if (nn->jvms() != NULL) {
1596 tty->print(" !jvms:");
1597 nn->jvms()->dump_spec(tty);
1598 }
1599 }
1600 }
1601 tty->cr();
1602 _in_dump_cnt--;
1603 }
1604
1605 //------------------------------dump_req--------------------------------------
1606 void Node::dump_req() const {
1607 // Dump the required input edges
1608 for (uint i = 0; i < req(); i++) { // For all required inputs
1609 Node* d = in(i);
1610 if (d == NULL) {
1611 tty->print("_ ");
1612 } else if (NotANode(d)) {
1613 tty->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1614 } else {
1615 tty->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1616 }
1617 }
1618 }
1619
1620
1621 //------------------------------dump_prec-------------------------------------
1622 void Node::dump_prec() const {
1623 // Dump the precedence edges
1624 int any_prec = 0;
1625 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1626 Node* p = in(i);
1627 if (p != NULL) {
1628 if( !any_prec++ ) tty->print(" |");
1629 if (NotANode(p)) { tty->print("NotANode "); continue; }
1630 tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1631 }
1632 }
1633 }
1634
1635 //------------------------------dump_out--------------------------------------
1636 void Node::dump_out() const {
1637 // Delimit the output edges
1638 tty->print(" [[");
1639 // Dump the output edges
1640 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1641 Node* u = _out[i];
1642 if (u == NULL) {
1643 tty->print("_ ");
1644 } else if (NotANode(u)) {
1645 tty->print("NotANode ");
1646 } else {
1647 tty->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1648 }
1649 }
1650 tty->print("]] ");
1651 }
1652
1653 //------------------------------dump_nodes-------------------------------------
1654 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1655 Node* s = (Node*)start; // remove const
1656 if (NotANode(s)) return;
1657
1658 uint depth = (uint)ABS(d);
1659 int direction = d;
1660 Compile* C = Compile::current();
1661 GrowableArray <Node *> nstack(C->unique());
1662
1663 nstack.append(s);
1664 int begin = 0;
1665 int end = 0;
1666 for(uint i = 0; i < depth; i++) {
1667 end = nstack.length();
1668 for(int j = begin; j < end; j++) {
1669 Node* tp = nstack.at(j);
1670 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1671 for(uint k = 0; k < limit; k++) {
1672 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1673
1674 if (NotANode(n)) continue;
1675 // do not recurse through top or the root (would reach unrelated stuff)
1676 if (n->is_Root() || n->is_top()) continue;
1677 if (only_ctrl && !n->is_CFG()) continue;
1678
1679 bool on_stack = nstack.contains(n);
1680 if (!on_stack) {
1681 nstack.append(n);
1682 }
1683 }
1684 }
1685 begin = end;
1686 }
1687 end = nstack.length();
1688 if (direction > 0) {
1689 for(int j = end-1; j >= 0; j--) {
1690 nstack.at(j)->dump();
1691 }
1692 } else {
1693 for(int j = 0; j < end; j++) {
1694 nstack.at(j)->dump();
1695 }
1696 }
1697 }
1698
1699 //------------------------------dump-------------------------------------------
1700 void Node::dump(int d) const {
1701 dump_nodes(this, d, false);
1702 }
1703
1704 //------------------------------dump_ctrl--------------------------------------
1705 // Dump a Node's control history to depth
1706 void Node::dump_ctrl(int d) const {
1707 dump_nodes(this, d, true);
1708 }
1709
1710 // VERIFICATION CODE
1711 // For each input edge to a node (ie - for each Use-Def edge), verify that
1712 // there is a corresponding Def-Use edge.
1713 //------------------------------verify_edges-----------------------------------
1714 void Node::verify_edges(Unique_Node_List &visited) {
1715 uint i, j, idx;
1716 int cnt;
1717 Node *n;
1718
1719 // Recursive termination test
1720 if (visited.member(this)) return;
1721 visited.push(this);
1722
1723 // Walk over all input edges, checking for correspondence
1724 for( i = 0; i < len(); i++ ) {
1725 n = in(i);
1726 if (n != NULL && !n->is_top()) {
1727 // Count instances of (Node *)this
1728 cnt = 0;
1729 for (idx = 0; idx < n->_outcnt; idx++ ) {
1730 if (n->_out[idx] == (Node *)this) cnt++;
1731 }
1732 assert( cnt > 0,"Failed to find Def-Use edge." );
1733 // Check for duplicate edges
1734 // walk the input array downcounting the input edges to n
1735 for( j = 0; j < len(); j++ ) {
1736 if( in(j) == n ) cnt--;
1737 }
1738 assert( cnt == 0,"Mismatched edge count.");
1739 } else if (n == NULL) {
1740 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1741 } else {
1742 assert(n->is_top(), "sanity");
1743 // Nothing to check.
1744 }
1745 }
1746 // Recursive walk over all input edges
1747 for( i = 0; i < len(); i++ ) {
1748 n = in(i);
1749 if( n != NULL )
1750 in(i)->verify_edges(visited);
1751 }
1752 }
1753
1754 //------------------------------verify_recur-----------------------------------
1755 static const Node *unique_top = NULL;
1756
1757 void Node::verify_recur(const Node *n, int verify_depth,
1758 VectorSet &old_space, VectorSet &new_space) {
1759 if ( verify_depth == 0 ) return;
1760 if (verify_depth > 0) --verify_depth;
1761
1762 Compile* C = Compile::current();
1763
1764 // Contained in new_space or old_space?
1765 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1766 // Check for visited in the proper space. Numberings are not unique
1767 // across spaces so we need a separate VectorSet for each space.
1768 if( v->test_set(n->_idx) ) return;
1769
1770 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1771 if (C->cached_top_node() == NULL)
1772 C->set_cached_top_node((Node*)n);
1773 assert(C->cached_top_node() == n, "TOP node must be unique");
1774 }
1775
1776 for( uint i = 0; i < n->len(); i++ ) {
1777 Node *x = n->in(i);
1778 if (!x || x->is_top()) continue;
1779
1780 // Verify my input has a def-use edge to me
1781 if (true /*VerifyDefUse*/) {
1782 // Count use-def edges from n to x
1783 int cnt = 0;
1784 for( uint j = 0; j < n->len(); j++ )
1785 if( n->in(j) == x )
1786 cnt++;
1787 // Count def-use edges from x to n
1788 uint max = x->_outcnt;
1789 for( uint k = 0; k < max; k++ )
1790 if (x->_out[k] == n)
1791 cnt--;
1792 assert( cnt == 0, "mismatched def-use edge counts" );
1793 }
1794
1795 verify_recur(x, verify_depth, old_space, new_space);
1796 }
1797
1798 }
1799
1800 //------------------------------verify-----------------------------------------
1801 // Check Def-Use info for my subgraph
1802 void Node::verify() const {
1803 Compile* C = Compile::current();
1804 Node* old_top = C->cached_top_node();
1805 ResourceMark rm;
1806 ResourceArea *area = Thread::current()->resource_area();
1807 VectorSet old_space(area), new_space(area);
1808 verify_recur(this, -1, old_space, new_space);
1809 C->set_cached_top_node(old_top);
1810 }
1811 #endif
1812
1813
1814 //------------------------------walk-------------------------------------------
1815 // Graph walk, with both pre-order and post-order functions
1816 void Node::walk(NFunc pre, NFunc post, void *env) {
1817 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1818 walk_(pre, post, env, visited);
1819 }
1820
1821 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1822 if( visited.test_set(_idx) ) return;
1823 pre(*this,env); // Call the pre-order walk function
1824 for( uint i=0; i<_max; i++ )
1825 if( in(i) ) // Input exists and is not walked?
1826 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1827 post(*this,env); // Call the post-order walk function
1828 }
1829
1830 void Node::nop(Node &, void*) {}
1831
1832 //------------------------------Registers--------------------------------------
1833 // Do we Match on this edge index or not? Generally false for Control
1834 // and true for everything else. Weird for calls & returns.
1835 uint Node::match_edge(uint idx) const {
1836 return idx; // True for other than index 0 (control)
1837 }
1838
1839 // Register classes are defined for specific machines
1840 const RegMask &Node::out_RegMask() const {
1841 ShouldNotCallThis();
1842 return *(new RegMask());
1843 }
1844
1845 const RegMask &Node::in_RegMask(uint) const {
1846 ShouldNotCallThis();
1847 return *(new RegMask());
1848 }
1849
1850 //=============================================================================
1851 //-----------------------------------------------------------------------------
1852 void Node_Array::reset( Arena *new_arena ) {
1853 _a->Afree(_nodes,_max*sizeof(Node*));
1854 _max = 0;
1855 _nodes = NULL;
1856 _a = new_arena;
1857 }
1858
1859 //------------------------------clear------------------------------------------
1860 // Clear all entries in _nodes to NULL but keep storage
1861 void Node_Array::clear() {
1862 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1863 }
1864
1865 //-----------------------------------------------------------------------------
1866 void Node_Array::grow( uint i ) {
1867 if( !_max ) {
1868 _max = 1;
1869 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1870 _nodes[0] = NULL;
1871 }
1872 uint old = _max;
1873 while( i >= _max ) _max <<= 1; // Double to fit
1874 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1875 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1876 }
1877
1878 //-----------------------------------------------------------------------------
1879 void Node_Array::insert( uint i, Node *n ) {
1880 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1881 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1882 _nodes[i] = n;
1883 }
1884
1885 //-----------------------------------------------------------------------------
1886 void Node_Array::remove( uint i ) {
1887 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1888 _nodes[_max-1] = NULL;
1889 }
1890
1891 //-----------------------------------------------------------------------------
1892 void Node_Array::sort( C_sort_func_t func) {
1893 qsort( _nodes, _max, sizeof( Node* ), func );
1894 }
1895
1896 //-----------------------------------------------------------------------------
1897 void Node_Array::dump() const {
1898 #ifndef PRODUCT
1899 for( uint i = 0; i < _max; i++ ) {
1900 Node *nn = _nodes[i];
1901 if( nn != NULL ) {
1902 tty->print("%5d--> ",i); nn->dump();
1903 }
1904 }
1905 #endif
1906 }
1907
1908 //--------------------------is_iteratively_computed------------------------------
1909 // Operation appears to be iteratively computed (such as an induction variable)
1910 // It is possible for this operation to return false for a loop-varying
1911 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1912 bool Node::is_iteratively_computed() {
1913 if (ideal_reg()) { // does operation have a result register?
1914 for (uint i = 1; i < req(); i++) {
1915 Node* n = in(i);
1916 if (n != NULL && n->is_Phi()) {
1917 for (uint j = 1; j < n->req(); j++) {
1918 if (n->in(j) == this) {
1919 return true;
1920 }
1921 }
1922 }
1923 }
1924 }
1925 return false;
1926 }
1927
1928 //--------------------------find_similar------------------------------
1929 // Return a node with opcode "opc" and same inputs as "this" if one can
1930 // be found; Otherwise return NULL;
1931 Node* Node::find_similar(int opc) {
1932 if (req() >= 2) {
1933 Node* def = in(1);
1934 if (def && def->outcnt() >= 2) {
1935 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
1936 Node* use = def->fast_out(i);
1937 if (use->Opcode() == opc &&
1938 use->req() == req()) {
1939 uint j;
1940 for (j = 0; j < use->req(); j++) {
1941 if (use->in(j) != in(j)) {
1942 break;
1943 }
1944 }
1945 if (j == use->req()) {
1946 return use;
1947 }
1948 }
1949 }
1950 }
1951 }
1952 return NULL;
1953 }
1954
1955
1956 //--------------------------unique_ctrl_out------------------------------
1957 // Return the unique control out if only one. Null if none or more than one.
1958 Node* Node::unique_ctrl_out() {
1959 Node* found = NULL;
1960 for (uint i = 0; i < outcnt(); i++) {
1961 Node* use = raw_out(i);
1962 if (use->is_CFG() && use != this) {
1963 if (found != NULL) return NULL;
1964 found = use;
1965 }
1966 }
1967 return found;
1968 }
1969
1970 //=============================================================================
1971 //------------------------------yank-------------------------------------------
1972 // Find and remove
1973 void Node_List::yank( Node *n ) {
1974 uint i;
1975 for( i = 0; i < _cnt; i++ )
1976 if( _nodes[i] == n )
1977 break;
1978
1979 if( i < _cnt )
1980 _nodes[i] = _nodes[--_cnt];
1981 }
1982
1983 //------------------------------dump-------------------------------------------
1984 void Node_List::dump() const {
1985 #ifndef PRODUCT
1986 for( uint i = 0; i < _cnt; i++ )
1987 if( _nodes[i] ) {
1988 tty->print("%5d--> ",i);
1989 _nodes[i]->dump();
1990 }
1991 #endif
1992 }
1993
1994 //=============================================================================
1995 //------------------------------remove-----------------------------------------
1996 void Unique_Node_List::remove( Node *n ) {
1997 if( _in_worklist[n->_idx] ) {
1998 for( uint i = 0; i < size(); i++ )
1999 if( _nodes[i] == n ) {
2000 map(i,Node_List::pop());
2001 _in_worklist >>= n->_idx;
2002 return;
2003 }
2004 ShouldNotReachHere();
2005 }
2006 }
2007
2008 //-----------------------remove_useless_nodes----------------------------------
2009 // Remove useless nodes from worklist
2010 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2011
2012 for( uint i = 0; i < size(); ++i ) {
2013 Node *n = at(i);
2014 assert( n != NULL, "Did not expect null entries in worklist");
2015 if( ! useful.test(n->_idx) ) {
2016 _in_worklist >>= n->_idx;
2017 map(i,Node_List::pop());
2018 // Node *replacement = Node_List::pop();
2019 // if( i != size() ) { // Check if removing last entry
2020 // _nodes[i] = replacement;
2021 // }
2022 --i; // Visit popped node
2023 // If it was last entry, loop terminates since size() was also reduced
2024 }
2025 }
2026 }
2027
2028 //=============================================================================
2029 void Node_Stack::grow() {
2030 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2031 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2032 size_t max = old_max << 1; // max * 2
2033 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2034 _inode_max = _inodes + max;
2035 _inode_top = _inodes + old_top; // restore _top
2036 }
2037
2038 // Node_Stack is used to map nodes.
2039 Node* Node_Stack::find(uint idx) const {
2040 uint sz = size();
2041 for (uint i=0; i < sz; i++) {
2042 if (idx == index_at(i) )
2043 return node_at(i);
2044 }
2045 return NULL;
2046 }
2047
2048 //=============================================================================
2049 uint TypeNode::size_of() const { return sizeof(*this); }
2050 #ifndef PRODUCT
2051 void TypeNode::dump_spec(outputStream *st) const {
2052 if( !Verbose && !WizardMode ) {
2053 // standard dump does this in Verbose and WizardMode
2054 st->print(" #"); _type->dump_on(st);
2055 }
2056 }
2057 #endif
2058 uint TypeNode::hash() const {
2059 return Node::hash() + _type->hash();
2060 }
2061 uint TypeNode::cmp( const Node &n ) const
2062 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2063 const Type *TypeNode::bottom_type() const { return _type; }
2064 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2065
2066 //------------------------------ideal_reg--------------------------------------
2067 uint TypeNode::ideal_reg() const {
2068 return _type->ideal_reg();
2069 }