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() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
71 assert(Compile::current()->live_nodes() < (uint)MaxNodeLimit, "Live Node limit exceeded limit");
72 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
73 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
74 BREAKPOINT;
75 }
76 #if OPTO_DU_ITERATOR_ASSERT
77 _last_del = NULL;
78 _del_tick = 0;
79 #endif
80 _hash_lock = 0;
81 }
82
83
84 // #ifdef ASSERT ...
85
86 #if OPTO_DU_ITERATOR_ASSERT
87 void DUIterator_Common::sample(const Node* node) {
88 _vdui = VerifyDUIterators;
89 _node = node;
90 _outcnt = node->_outcnt;
91 _del_tick = node->_del_tick;
92 _last = NULL;
93 }
94
95 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
96 assert(_node == node, "consistent iterator source");
97 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
98 }
99
100 void DUIterator_Common::verify_resync() {
101 // Ensure that the loop body has just deleted the last guy produced.
102 const Node* node = _node;
103 // Ensure that at least one copy of the last-seen edge was deleted.
104 // Note: It is OK to delete multiple copies of the last-seen edge.
105 // Unfortunately, we have no way to verify that all the deletions delete
106 // that same edge. On this point we must use the Honor System.
107 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
108 assert(node->_last_del == _last, "must have deleted the edge just produced");
109 // We liked this deletion, so accept the resulting outcnt and tick.
110 _outcnt = node->_outcnt;
111 _del_tick = node->_del_tick;
112 }
113
114 void DUIterator_Common::reset(const DUIterator_Common& that) {
115 if (this == &that) return; // ignore assignment to self
116 if (!_vdui) {
117 // We need to initialize everything, overwriting garbage values.
118 _last = that._last;
119 _vdui = that._vdui;
120 }
121 // Note: It is legal (though odd) for an iterator over some node x
122 // to be reassigned to iterate over another node y. Some doubly-nested
123 // progress loops depend on being able to do this.
124 const Node* node = that._node;
125 // Re-initialize everything, except _last.
126 _node = node;
127 _outcnt = node->_outcnt;
128 _del_tick = node->_del_tick;
129 }
130
131 void DUIterator::sample(const Node* node) {
132 DUIterator_Common::sample(node); // Initialize the assertion data.
133 _refresh_tick = 0; // No refreshes have happened, as yet.
134 }
135
136 void DUIterator::verify(const Node* node, bool at_end_ok) {
137 DUIterator_Common::verify(node, at_end_ok);
138 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
139 }
140
141 void DUIterator::verify_increment() {
142 if (_refresh_tick & 1) {
143 // We have refreshed the index during this loop.
144 // Fix up _idx to meet asserts.
145 if (_idx > _outcnt) _idx = _outcnt;
146 }
147 verify(_node, true);
148 }
149
150 void DUIterator::verify_resync() {
151 // Note: We do not assert on _outcnt, because insertions are OK here.
152 DUIterator_Common::verify_resync();
153 // Make sure we are still in sync, possibly with no more out-edges:
154 verify(_node, true);
155 }
156
157 void DUIterator::reset(const DUIterator& that) {
158 if (this == &that) return; // self assignment is always a no-op
159 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
160 assert(that._idx == 0, "assign only the result of Node::outs()");
161 assert(_idx == that._idx, "already assigned _idx");
162 if (!_vdui) {
163 // We need to initialize everything, overwriting garbage values.
164 sample(that._node);
165 } else {
166 DUIterator_Common::reset(that);
167 if (_refresh_tick & 1) {
168 _refresh_tick++; // Clear the "was refreshed" flag.
169 }
170 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
171 }
172 }
173
174 void DUIterator::refresh() {
175 DUIterator_Common::sample(_node); // Re-fetch assertion data.
176 _refresh_tick |= 1; // Set the "was refreshed" flag.
177 }
178
179 void DUIterator::verify_finish() {
180 // If the loop has killed the node, do not require it to re-run.
181 if (_node->_outcnt == 0) _refresh_tick &= ~1;
182 // If this assert triggers, it means that a loop used refresh_out_pos
183 // to re-synch an iteration index, but the loop did not correctly
184 // re-run itself, using a "while (progress)" construct.
185 // This iterator enforces the rule that you must keep trying the loop
186 // until it "runs clean" without any need for refreshing.
187 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
188 }
189
190
191 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
192 DUIterator_Common::verify(node, at_end_ok);
193 Node** out = node->_out;
194 uint cnt = node->_outcnt;
195 assert(cnt == _outcnt, "no insertions allowed");
196 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
197 // This last check is carefully designed to work for NO_OUT_ARRAY.
198 }
199
200 void DUIterator_Fast::verify_limit() {
201 const Node* node = _node;
202 verify(node, true);
203 assert(_outp == node->_out + node->_outcnt, "limit still correct");
204 }
205
206 void DUIterator_Fast::verify_resync() {
207 const Node* node = _node;
208 if (_outp == node->_out + _outcnt) {
209 // Note that the limit imax, not the pointer i, gets updated with the
210 // exact count of deletions. (For the pointer it's always "--i".)
211 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
212 // This is a limit pointer, with a name like "imax".
213 // Fudge the _last field so that the common assert will be happy.
214 _last = (Node*) node->_last_del;
215 DUIterator_Common::verify_resync();
216 } else {
217 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
218 // A normal internal pointer.
219 DUIterator_Common::verify_resync();
220 // Make sure we are still in sync, possibly with no more out-edges:
221 verify(node, true);
222 }
223 }
224
225 void DUIterator_Fast::verify_relimit(uint n) {
226 const Node* node = _node;
227 assert((int)n > 0, "use imax -= n only with a positive count");
228 // This must be a limit pointer, with a name like "imax".
229 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
230 // The reported number of deletions must match what the node saw.
231 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
232 // Fudge the _last field so that the common assert will be happy.
233 _last = (Node*) node->_last_del;
234 DUIterator_Common::verify_resync();
235 }
236
237 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
238 assert(_outp == that._outp, "already assigned _outp");
239 DUIterator_Common::reset(that);
240 }
241
242 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
243 // at_end_ok means the _outp is allowed to underflow by 1
244 _outp += at_end_ok;
245 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
246 _outp -= at_end_ok;
247 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
248 }
249
250 void DUIterator_Last::verify_limit() {
251 // Do not require the limit address to be resynched.
252 //verify(node, true);
253 assert(_outp == _node->_out, "limit still correct");
254 }
255
256 void DUIterator_Last::verify_step(uint num_edges) {
257 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
258 _outcnt -= num_edges;
259 _del_tick += num_edges;
260 // Make sure we are still in sync, possibly with no more out-edges:
261 const Node* node = _node;
262 verify(node, true);
263 assert(node->_last_del == _last, "must have deleted the edge just produced");
264 }
265
266 #endif //OPTO_DU_ITERATOR_ASSERT
267
268
269 #endif //ASSERT
270
271
272 // This constant used to initialize _out may be any non-null value.
273 // The value NULL is reserved for the top node only.
274 #define NO_OUT_ARRAY ((Node**)-1)
275
276 // This funny expression handshakes with Node::operator new
277 // to pull Compile::current out of the new node's _out field,
278 // and then calls a subroutine which manages most field
279 // initializations. The only one which is tricky is the
280 // _idx field, which is const, and so must be initialized
281 // by a return value, not an assignment.
282 //
283 // (Aren't you thankful that Java finals don't require so many tricks?)
284 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
285 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
286 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
287 #endif
288
289 // Out-of-line code from node constructors.
290 // Executed only when extra debug info. is being passed around.
291 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
292 C->set_node_notes_at(idx, nn);
293 }
294
295 // Shared initialization code.
296 inline int Node::Init(int req, Compile* C) {
297 assert(Compile::current() == C, "must use operator new(Compile*)");
298 int idx = C->next_unique();
299
300 // Allocate memory for the necessary number of edges.
301 if (req > 0) {
302 // Allocate space for _in array to have double alignment.
303 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
304 #ifdef ASSERT
305 _in[req-1] = this; // magic cookie for assertion check
306 #endif
307 }
308 // If there are default notes floating around, capture them:
309 Node_Notes* nn = C->default_node_notes();
310 if (nn != NULL) init_node_notes(C, idx, nn);
311
312 // Note: At this point, C is dead,
313 // and we begin to initialize the new Node.
314
315 _cnt = _max = req;
316 _outcnt = _outmax = 0;
317 _class_id = Class_Node;
318 _flags = 0;
319 _out = NO_OUT_ARRAY;
320 return idx;
321 }
322
323 //------------------------------Node-------------------------------------------
324 // Create a Node, with a given number of required edges.
325 Node::Node(uint req)
326 : _idx(IDX_INIT(req))
327 {
328 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
329 debug_only( verify_construction() );
330 NOT_PRODUCT(nodes_created++);
331 if (req == 0) {
332 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
333 _in = NULL;
334 } else {
335 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
336 Node** to = _in;
337 for(uint i = 0; i < req; i++) {
338 to[i] = NULL;
339 }
340 }
341 }
342
343 //------------------------------Node-------------------------------------------
344 Node::Node(Node *n0)
345 : _idx(IDX_INIT(1))
346 {
347 debug_only( verify_construction() );
348 NOT_PRODUCT(nodes_created++);
349 // Assert we allocated space for input array already
350 assert( _in[0] == this, "Must pass arg count to 'new'" );
351 assert( is_not_dead(n0), "can not use dead node");
352 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
353 }
354
355 //------------------------------Node-------------------------------------------
356 Node::Node(Node *n0, Node *n1)
357 : _idx(IDX_INIT(2))
358 {
359 debug_only( verify_construction() );
360 NOT_PRODUCT(nodes_created++);
361 // Assert we allocated space for input array already
362 assert( _in[1] == this, "Must pass arg count to 'new'" );
363 assert( is_not_dead(n0), "can not use dead node");
364 assert( is_not_dead(n1), "can not use dead node");
365 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
366 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
367 }
368
369 //------------------------------Node-------------------------------------------
370 Node::Node(Node *n0, Node *n1, Node *n2)
371 : _idx(IDX_INIT(3))
372 {
373 debug_only( verify_construction() );
374 NOT_PRODUCT(nodes_created++);
375 // Assert we allocated space for input array already
376 assert( _in[2] == this, "Must pass arg count to 'new'" );
377 assert( is_not_dead(n0), "can not use dead node");
378 assert( is_not_dead(n1), "can not use dead node");
379 assert( is_not_dead(n2), "can not use dead node");
380 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
381 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
382 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
383 }
384
385 //------------------------------Node-------------------------------------------
386 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
387 : _idx(IDX_INIT(4))
388 {
389 debug_only( verify_construction() );
390 NOT_PRODUCT(nodes_created++);
391 // Assert we allocated space for input array already
392 assert( _in[3] == this, "Must pass arg count to 'new'" );
393 assert( is_not_dead(n0), "can not use dead node");
394 assert( is_not_dead(n1), "can not use dead node");
395 assert( is_not_dead(n2), "can not use dead node");
396 assert( is_not_dead(n3), "can not use dead node");
397 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
398 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
399 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
400 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
401 }
402
403 //------------------------------Node-------------------------------------------
404 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
405 : _idx(IDX_INIT(5))
406 {
407 debug_only( verify_construction() );
408 NOT_PRODUCT(nodes_created++);
409 // Assert we allocated space for input array already
410 assert( _in[4] == this, "Must pass arg count to 'new'" );
411 assert( is_not_dead(n0), "can not use dead node");
412 assert( is_not_dead(n1), "can not use dead node");
413 assert( is_not_dead(n2), "can not use dead node");
414 assert( is_not_dead(n3), "can not use dead node");
415 assert( is_not_dead(n4), "can not use dead node");
416 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
417 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
418 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
419 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
420 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
421 }
422
423 //------------------------------Node-------------------------------------------
424 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
425 Node *n4, Node *n5)
426 : _idx(IDX_INIT(6))
427 {
428 debug_only( verify_construction() );
429 NOT_PRODUCT(nodes_created++);
430 // Assert we allocated space for input array already
431 assert( _in[5] == this, "Must pass arg count to 'new'" );
432 assert( is_not_dead(n0), "can not use dead node");
433 assert( is_not_dead(n1), "can not use dead node");
434 assert( is_not_dead(n2), "can not use dead node");
435 assert( is_not_dead(n3), "can not use dead node");
436 assert( is_not_dead(n4), "can not use dead node");
437 assert( is_not_dead(n5), "can not use dead node");
438 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
439 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
440 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
441 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
442 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
443 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
444 }
445
446 //------------------------------Node-------------------------------------------
447 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
448 Node *n4, Node *n5, Node *n6)
449 : _idx(IDX_INIT(7))
450 {
451 debug_only( verify_construction() );
452 NOT_PRODUCT(nodes_created++);
453 // Assert we allocated space for input array already
454 assert( _in[6] == this, "Must pass arg count to 'new'" );
455 assert( is_not_dead(n0), "can not use dead node");
456 assert( is_not_dead(n1), "can not use dead node");
457 assert( is_not_dead(n2), "can not use dead node");
458 assert( is_not_dead(n3), "can not use dead node");
459 assert( is_not_dead(n4), "can not use dead node");
460 assert( is_not_dead(n5), "can not use dead node");
461 assert( is_not_dead(n6), "can not use dead node");
462 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
463 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
464 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
465 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
466 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
467 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
468 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
469 }
470
471
472 //------------------------------clone------------------------------------------
473 // Clone a Node.
474 Node *Node::clone() const {
475 Compile* C = Compile::current();
476 uint s = size_of(); // Size of inherited Node
477 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
478 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
479 // Set the new input pointer array
480 n->_in = (Node**)(((char*)n)+s);
481 // Cannot share the old output pointer array, so kill it
482 n->_out = NO_OUT_ARRAY;
483 // And reset the counters to 0
484 n->_outcnt = 0;
485 n->_outmax = 0;
486 // Unlock this guy, since he is not in any hash table.
487 debug_only(n->_hash_lock = 0);
488 // Walk the old node's input list to duplicate its edges
489 uint i;
490 for( i = 0; i < len(); i++ ) {
491 Node *x = in(i);
492 n->_in[i] = x;
493 if (x != NULL) x->add_out(n);
494 }
495 if (is_macro())
496 C->add_macro_node(n);
497 if (is_expensive())
498 C->add_expensive_node(n);
499
500 n->set_idx(C->next_unique()); // Get new unique index as well
501 debug_only( n->verify_construction() );
502 NOT_PRODUCT(nodes_created++);
503 // Do not patch over the debug_idx of a clone, because it makes it
504 // impossible to break on the clone's moment of creation.
505 //debug_only( n->set_debug_idx( debug_idx() ) );
506
507 C->copy_node_notes_to(n, (Node*) this);
508
509 // MachNode clone
510 uint nopnds;
511 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
512 MachNode *mach = n->as_Mach();
513 MachNode *mthis = this->as_Mach();
514 // Get address of _opnd_array.
515 // It should be the same offset since it is the clone of this node.
516 MachOper **from = mthis->_opnds;
517 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
518 pointer_delta((const void*)from,
519 (const void*)(&mthis->_opnds), 1));
520 mach->_opnds = to;
521 for ( uint i = 0; i < nopnds; ++i ) {
522 to[i] = from[i]->clone(C);
523 }
524 }
525 // cloning CallNode may need to clone JVMState
526 if (n->is_Call()) {
527 n->as_Call()->clone_jvms(C);
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 //------------------------------del_req_ordered--------------------------------
777 // Delete the required edge and compact the edge array with preserved order
778 void Node::del_req_ordered( uint idx ) {
779 assert( idx < _cnt, "oob");
780 assert( !VerifyHashTableKeys || _hash_lock == 0,
781 "remove node from hash table before modifying it");
782 // First remove corresponding def-use edge
783 Node *n = in(idx);
784 if (n != NULL) n->del_out((Node *)this);
785 if (idx < _cnt - 1) { // Not last edge ?
786 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
787 }
788 _in[--_cnt] = NULL; // NULL out emptied slot
789 }
790
791 //------------------------------ins_req----------------------------------------
792 // Insert a new required input at the end
793 void Node::ins_req( uint idx, Node *n ) {
794 assert( is_not_dead(n), "can not use dead node");
795 add_req(NULL); // Make space
796 assert( idx < _max, "Must have allocated enough space");
797 // Slide over
798 if(_cnt-idx-1 > 0) {
799 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
800 }
801 _in[idx] = n; // Stuff over old required edge
802 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
803 }
804
805 //-----------------------------find_edge---------------------------------------
806 int Node::find_edge(Node* n) {
807 for (uint i = 0; i < len(); i++) {
808 if (_in[i] == n) return i;
809 }
810 return -1;
811 }
812
813 //----------------------------replace_edge-------------------------------------
814 int Node::replace_edge(Node* old, Node* neww) {
815 if (old == neww) return 0; // nothing to do
816 uint nrep = 0;
817 for (uint i = 0; i < len(); i++) {
818 if (in(i) == old) {
819 if (i < req())
820 set_req(i, neww);
821 else
822 set_prec(i, neww);
823 nrep++;
824 }
825 }
826 return nrep;
827 }
828
829 /**
830 * Replace input edges in the range pointing to 'old' node.
831 */
832 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
833 if (old == neww) return 0; // nothing to do
834 uint nrep = 0;
835 for (int i = start; i < end; i++) {
836 if (in(i) == old) {
837 set_req(i, neww);
838 nrep++;
839 }
840 }
841 return nrep;
842 }
843
844 //-------------------------disconnect_inputs-----------------------------------
845 // NULL out all inputs to eliminate incoming Def-Use edges.
846 // Return the number of edges between 'n' and 'this'
847 int Node::disconnect_inputs(Node *n, Compile* C) {
848 int edges_to_n = 0;
849
850 uint cnt = req();
851 for( uint i = 0; i < cnt; ++i ) {
852 if( in(i) == 0 ) continue;
853 if( in(i) == n ) ++edges_to_n;
854 set_req(i, NULL);
855 }
856 // Remove precedence edges if any exist
857 // Note: Safepoints may have precedence edges, even during parsing
858 if( (req() != len()) && (in(req()) != NULL) ) {
859 uint max = len();
860 for( uint i = 0; i < max; ++i ) {
861 if( in(i) == 0 ) continue;
862 if( in(i) == n ) ++edges_to_n;
863 set_prec(i, NULL);
864 }
865 }
866
867 // Node::destruct requires all out edges be deleted first
868 // debug_only(destruct();) // no reuse benefit expected
869 if (edges_to_n == 0) {
870 C->record_dead_node(_idx);
871 }
872 return edges_to_n;
873 }
874
875 //-----------------------------uncast---------------------------------------
876 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
877 // Strip away casting. (It is depth-limited.)
878 Node* Node::uncast() const {
879 // Should be inline:
880 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
881 if (is_ConstraintCast() || is_CheckCastPP())
882 return uncast_helper(this);
883 else
884 return (Node*) this;
885 }
886
887 //---------------------------uncast_helper-------------------------------------
888 Node* Node::uncast_helper(const Node* p) {
889 #ifdef ASSERT
890 uint depth_count = 0;
891 const Node* orig_p = p;
892 #endif
893
894 while (true) {
895 #ifdef ASSERT
896 if (depth_count >= K) {
897 orig_p->dump(4);
898 if (p != orig_p)
899 p->dump(1);
900 }
901 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
902 #endif
903 if (p == NULL || p->req() != 2) {
904 break;
905 } else if (p->is_ConstraintCast()) {
906 p = p->in(1);
907 } else if (p->is_CheckCastPP()) {
908 p = p->in(1);
909 } else {
910 break;
911 }
912 }
913 return (Node*) p;
914 }
915
916 //------------------------------add_prec---------------------------------------
917 // Add a new precedence input. Precedence inputs are unordered, with
918 // duplicates removed and NULLs packed down at the end.
919 void Node::add_prec( Node *n ) {
920 assert( is_not_dead(n), "can not use dead node");
921
922 // Check for NULL at end
923 if( _cnt >= _max || in(_max-1) )
924 grow( _max+1 );
925
926 // Find a precedence edge to move
927 uint i = _cnt;
928 while( in(i) != NULL ) i++;
929 _in[i] = n; // Stuff prec edge over NULL
930 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
931 }
932
933 //------------------------------rm_prec----------------------------------------
934 // Remove a precedence input. Precedence inputs are unordered, with
935 // duplicates removed and NULLs packed down at the end.
936 void Node::rm_prec( uint j ) {
937
938 // Find end of precedence list to pack NULLs
939 uint i;
940 for( i=j; i<_max; i++ )
941 if( !_in[i] ) // Find the NULL at end of prec edge list
942 break;
943 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
944 _in[j] = _in[--i]; // Move last element over removed guy
945 _in[i] = NULL; // NULL out last element
946 }
947
948 //------------------------------size_of----------------------------------------
949 uint Node::size_of() const { return sizeof(*this); }
950
951 //------------------------------ideal_reg--------------------------------------
952 uint Node::ideal_reg() const { return 0; }
953
954 //------------------------------jvms-------------------------------------------
955 JVMState* Node::jvms() const { return NULL; }
956
957 #ifdef ASSERT
958 //------------------------------jvms-------------------------------------------
959 bool Node::verify_jvms(const JVMState* using_jvms) const {
960 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
961 if (jvms == using_jvms) return true;
962 }
963 return false;
964 }
965
966 //------------------------------init_NodeProperty------------------------------
967 void Node::init_NodeProperty() {
968 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
969 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
970 }
971 #endif
972
973 //------------------------------format-----------------------------------------
974 // Print as assembly
975 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
976 //------------------------------emit-------------------------------------------
977 // Emit bytes starting at parameter 'ptr'.
978 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
979 //------------------------------lateExpand-------------------------------------
980 // Expand node after register allocation.
981 void Node::lateExpand(GrowableArray <Node *> *nodes, PhaseRegAlloc *ra_) {}
982 //------------------------------size-------------------------------------------
983 // Size of instruction in bytes
984 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
985
986 //------------------------------CFG Construction-------------------------------
987 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
988 // Goto and Return.
989 const Node *Node::is_block_proj() const { return 0; }
990
991 // Minimum guaranteed type
992 const Type *Node::bottom_type() const { return Type::BOTTOM; }
993
994
995 //------------------------------raise_bottom_type------------------------------
996 // Get the worst-case Type output for this Node.
997 void Node::raise_bottom_type(const Type* new_type) {
998 if (is_Type()) {
999 TypeNode *n = this->as_Type();
1000 if (VerifyAliases) {
1001 assert(new_type->higher_equal(n->type()), "new type must refine old type");
1002 }
1003 n->set_type(new_type);
1004 } else if (is_Load()) {
1005 LoadNode *n = this->as_Load();
1006 if (VerifyAliases) {
1007 assert(new_type->higher_equal(n->type()), "new type must refine old type");
1008 }
1009 n->set_type(new_type);
1010 }
1011 }
1012
1013 //------------------------------Identity---------------------------------------
1014 // Return a node that the given node is equivalent to.
1015 Node *Node::Identity( PhaseTransform * ) {
1016 return this; // Default to no identities
1017 }
1018
1019 //------------------------------Value------------------------------------------
1020 // Compute a new Type for a node using the Type of the inputs.
1021 const Type *Node::Value( PhaseTransform * ) const {
1022 return bottom_type(); // Default to worst-case Type
1023 }
1024
1025 //------------------------------Ideal------------------------------------------
1026 //
1027 // 'Idealize' the graph rooted at this Node.
1028 //
1029 // In order to be efficient and flexible there are some subtle invariants
1030 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1031 // these invariants, although its too slow to have on by default. If you are
1032 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1033 //
1034 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1035 // pointer. If ANY change is made, it must return the root of the reshaped
1036 // graph - even if the root is the same Node. Example: swapping the inputs
1037 // to an AddINode gives the same answer and same root, but you still have to
1038 // return the 'this' pointer instead of NULL.
1039 //
1040 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1041 // Identity call to return an old Node; basically if Identity can find
1042 // another Node have the Ideal call make no change and return NULL.
1043 // Example: AddINode::Ideal must check for add of zero; in this case it
1044 // returns NULL instead of doing any graph reshaping.
1045 //
1046 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1047 // sharing there may be other users of the old Nodes relying on their current
1048 // semantics. Modifying them will break the other users.
1049 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1050 // "X+3" unchanged in case it is shared.
1051 //
1052 // If you modify the 'this' pointer's inputs, you should use
1053 // 'set_req'. If you are making a new Node (either as the new root or
1054 // some new internal piece) you may use 'init_req' to set the initial
1055 // value. You can make a new Node with either 'new' or 'clone'. In
1056 // either case, def-use info is correctly maintained.
1057 //
1058 // Example: reshape "(X+3)+4" into "X+7":
1059 // set_req(1, in(1)->in(1));
1060 // set_req(2, phase->intcon(7));
1061 // return this;
1062 // Example: reshape "X*4" into "X<<2"
1063 // return new (C) LShiftINode(in(1), phase->intcon(2));
1064 //
1065 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1066 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1067 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1068 // return new (C) AddINode(shift, in(1));
1069 //
1070 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1071 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1072 // The Right Thing with def-use info.
1073 //
1074 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1075 // graph uses the 'this' Node it must be the root. If you want a Node with
1076 // the same Opcode as the 'this' pointer use 'clone'.
1077 //
1078 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1079 return NULL; // Default to being Ideal already
1080 }
1081
1082 // Some nodes have specific Ideal subgraph transformations only if they are
1083 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1084 // for the transformations to happen.
1085 bool Node::has_special_unique_user() const {
1086 assert(outcnt() == 1, "match only for unique out");
1087 Node* n = unique_out();
1088 int op = Opcode();
1089 if( this->is_Store() ) {
1090 // Condition for back-to-back stores folding.
1091 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1092 } else if( op == Op_AddL ) {
1093 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1094 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1095 } else if( op == Op_SubI || op == Op_SubL ) {
1096 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1097 return n->Opcode() == op && n->in(2) == this;
1098 }
1099 return false;
1100 };
1101
1102 //--------------------------find_exact_control---------------------------------
1103 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1104 Node* Node::find_exact_control(Node* ctrl) {
1105 if (ctrl == NULL && this->is_Region())
1106 ctrl = this->as_Region()->is_copy();
1107
1108 if (ctrl != NULL && ctrl->is_CatchProj()) {
1109 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1110 ctrl = ctrl->in(0);
1111 if (ctrl != NULL && !ctrl->is_top())
1112 ctrl = ctrl->in(0);
1113 }
1114
1115 if (ctrl != NULL && ctrl->is_Proj())
1116 ctrl = ctrl->in(0);
1117
1118 return ctrl;
1119 }
1120
1121 //--------------------------dominates------------------------------------------
1122 // Helper function for MemNode::all_controls_dominate().
1123 // Check if 'this' control node dominates or equal to 'sub' control node.
1124 // We already know that if any path back to Root or Start reaches 'this',
1125 // then all paths so, so this is a simple search for one example,
1126 // not an exhaustive search for a counterexample.
1127 bool Node::dominates(Node* sub, Node_List &nlist) {
1128 assert(this->is_CFG(), "expecting control");
1129 assert(sub != NULL && sub->is_CFG(), "expecting control");
1130
1131 // detect dead cycle without regions
1132 int iterations_without_region_limit = DominatorSearchLimit;
1133
1134 Node* orig_sub = sub;
1135 Node* dom = this;
1136 bool met_dom = false;
1137 nlist.clear();
1138
1139 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1140 // After seeing 'dom', continue up to Root or Start.
1141 // If we hit a region (backward split point), it may be a loop head.
1142 // Keep going through one of the region's inputs. If we reach the
1143 // same region again, go through a different input. Eventually we
1144 // will either exit through the loop head, or give up.
1145 // (If we get confused, break out and return a conservative 'false'.)
1146 while (sub != NULL) {
1147 if (sub->is_top()) break; // Conservative answer for dead code.
1148 if (sub == dom) {
1149 if (nlist.size() == 0) {
1150 // No Region nodes except loops were visited before and the EntryControl
1151 // path was taken for loops: it did not walk in a cycle.
1152 return true;
1153 } else if (met_dom) {
1154 break; // already met before: walk in a cycle
1155 } else {
1156 // Region nodes were visited. Continue walk up to Start or Root
1157 // to make sure that it did not walk in a cycle.
1158 met_dom = true; // first time meet
1159 iterations_without_region_limit = DominatorSearchLimit; // Reset
1160 }
1161 }
1162 if (sub->is_Start() || sub->is_Root()) {
1163 // Success if we met 'dom' along a path to Start or Root.
1164 // We assume there are no alternative paths that avoid 'dom'.
1165 // (This assumption is up to the caller to ensure!)
1166 return met_dom;
1167 }
1168 Node* up = sub->in(0);
1169 // Normalize simple pass-through regions and projections:
1170 up = sub->find_exact_control(up);
1171 // If sub == up, we found a self-loop. Try to push past it.
1172 if (sub == up && sub->is_Loop()) {
1173 // Take loop entry path on the way up to 'dom'.
1174 up = sub->in(1); // in(LoopNode::EntryControl);
1175 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1176 // Always take in(1) path on the way up to 'dom' for clone regions
1177 // (with only one input) or regions which merge > 2 paths
1178 // (usually used to merge fast/slow paths).
1179 up = sub->in(1);
1180 } else if (sub == up && sub->is_Region()) {
1181 // Try both paths for Regions with 2 input paths (it may be a loop head).
1182 // It could give conservative 'false' answer without information
1183 // which region's input is the entry path.
1184 iterations_without_region_limit = DominatorSearchLimit; // Reset
1185
1186 bool region_was_visited_before = false;
1187 // Was this Region node visited before?
1188 // If so, we have reached it because we accidentally took a
1189 // loop-back edge from 'sub' back into the body of the loop,
1190 // and worked our way up again to the loop header 'sub'.
1191 // So, take the first unexplored path on the way up to 'dom'.
1192 for (int j = nlist.size() - 1; j >= 0; j--) {
1193 intptr_t ni = (intptr_t)nlist.at(j);
1194 Node* visited = (Node*)(ni & ~1);
1195 bool visited_twice_already = ((ni & 1) != 0);
1196 if (visited == sub) {
1197 if (visited_twice_already) {
1198 // Visited 2 paths, but still stuck in loop body. Give up.
1199 return false;
1200 }
1201 // The Region node was visited before only once.
1202 // (We will repush with the low bit set, below.)
1203 nlist.remove(j);
1204 // We will find a new edge and re-insert.
1205 region_was_visited_before = true;
1206 break;
1207 }
1208 }
1209
1210 // Find an incoming edge which has not been seen yet; walk through it.
1211 assert(up == sub, "");
1212 uint skip = region_was_visited_before ? 1 : 0;
1213 for (uint i = 1; i < sub->req(); i++) {
1214 Node* in = sub->in(i);
1215 if (in != NULL && !in->is_top() && in != sub) {
1216 if (skip == 0) {
1217 up = in;
1218 break;
1219 }
1220 --skip; // skip this nontrivial input
1221 }
1222 }
1223
1224 // Set 0 bit to indicate that both paths were taken.
1225 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1226 }
1227
1228 if (up == sub) {
1229 break; // some kind of tight cycle
1230 }
1231 if (up == orig_sub && met_dom) {
1232 // returned back after visiting 'dom'
1233 break; // some kind of cycle
1234 }
1235 if (--iterations_without_region_limit < 0) {
1236 break; // dead cycle
1237 }
1238 sub = up;
1239 }
1240
1241 // Did not meet Root or Start node in pred. chain.
1242 // Conservative answer for dead code.
1243 return false;
1244 }
1245
1246 //------------------------------remove_dead_region-----------------------------
1247 // This control node is dead. Follow the subgraph below it making everything
1248 // using it dead as well. This will happen normally via the usual IterGVN
1249 // worklist but this call is more efficient. Do not update use-def info
1250 // inside the dead region, just at the borders.
1251 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1252 // Con's are a popular node to re-hit in the hash table again.
1253 if( dead->is_Con() ) return;
1254
1255 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1256 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1257 Node_List nstack(Thread::current()->resource_area());
1258
1259 Node *top = igvn->C->top();
1260 nstack.push(dead);
1261
1262 while (nstack.size() > 0) {
1263 dead = nstack.pop();
1264 if (dead->outcnt() > 0) {
1265 // Keep dead node on stack until all uses are processed.
1266 nstack.push(dead);
1267 // For all Users of the Dead... ;-)
1268 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1269 Node* use = dead->last_out(k);
1270 igvn->hash_delete(use); // Yank from hash table prior to mod
1271 if (use->in(0) == dead) { // Found another dead node
1272 assert (!use->is_Con(), "Control for Con node should be Root node.");
1273 use->set_req(0, top); // Cut dead edge to prevent processing
1274 nstack.push(use); // the dead node again.
1275 } else { // Else found a not-dead user
1276 for (uint j = 1; j < use->req(); j++) {
1277 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1278 use->set_req(j, top);
1279 }
1280 }
1281 igvn->_worklist.push(use);
1282 }
1283 // Refresh the iterator, since any number of kills might have happened.
1284 k = dead->last_outs(kmin);
1285 }
1286 } else { // (dead->outcnt() == 0)
1287 // Done with outputs.
1288 igvn->hash_delete(dead);
1289 igvn->_worklist.remove(dead);
1290 igvn->set_type(dead, Type::TOP);
1291 if (dead->is_macro()) {
1292 igvn->C->remove_macro_node(dead);
1293 }
1294 if (dead->is_expensive()) {
1295 igvn->C->remove_expensive_node(dead);
1296 }
1297 igvn->C->record_dead_node(dead->_idx);
1298 // Kill all inputs to the dead guy
1299 for (uint i=0; i < dead->req(); i++) {
1300 Node *n = dead->in(i); // Get input to dead guy
1301 if (n != NULL && !n->is_top()) { // Input is valid?
1302 dead->set_req(i, top); // Smash input away
1303 if (n->outcnt() == 0) { // Input also goes dead?
1304 if (!n->is_Con())
1305 nstack.push(n); // Clear it out as well
1306 } else if (n->outcnt() == 1 &&
1307 n->has_special_unique_user()) {
1308 igvn->add_users_to_worklist( n );
1309 } else if (n->outcnt() <= 2 && n->is_Store()) {
1310 // Push store's uses on worklist to enable folding optimization for
1311 // store/store and store/load to the same address.
1312 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1313 // and remove_globally_dead_node().
1314 igvn->add_users_to_worklist( n );
1315 }
1316 }
1317 }
1318 } // (dead->outcnt() == 0)
1319 } // while (nstack.size() > 0) for outputs
1320 return;
1321 }
1322
1323 //------------------------------remove_dead_region-----------------------------
1324 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1325 Node *n = in(0);
1326 if( !n ) return false;
1327 // Lost control into this guy? I.e., it became unreachable?
1328 // Aggressively kill all unreachable code.
1329 if (can_reshape && n->is_top()) {
1330 kill_dead_code(this, phase->is_IterGVN());
1331 return false; // Node is dead.
1332 }
1333
1334 if( n->is_Region() && n->as_Region()->is_copy() ) {
1335 Node *m = n->nonnull_req();
1336 set_req(0, m);
1337 return true;
1338 }
1339 return false;
1340 }
1341
1342 //------------------------------Ideal_DU_postCCP-------------------------------
1343 // Idealize graph, using DU info. Must clone result into new-space
1344 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1345 return NULL; // Default to no change
1346 }
1347
1348 //------------------------------hash-------------------------------------------
1349 // Hash function over Nodes.
1350 uint Node::hash() const {
1351 uint sum = 0;
1352 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1353 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1354 return (sum>>2) + _cnt + Opcode();
1355 }
1356
1357 //------------------------------cmp--------------------------------------------
1358 // Compare special parts of simple Nodes
1359 uint Node::cmp( const Node &n ) const {
1360 return 1; // Must be same
1361 }
1362
1363 //------------------------------rematerialize-----------------------------------
1364 // Should we clone rather than spill this instruction?
1365 bool Node::rematerialize() const {
1366 if ( is_Mach() )
1367 return this->as_Mach()->rematerialize();
1368 else
1369 return (_flags & Flag_rematerialize) != 0;
1370 }
1371
1372 //------------------------------needs_anti_dependence_check---------------------
1373 // Nodes which use memory without consuming it, hence need antidependences.
1374 bool Node::needs_anti_dependence_check() const {
1375 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1376 return false;
1377 else
1378 return in(1)->bottom_type()->has_memory();
1379 }
1380
1381
1382 // Get an integer constant from a ConNode (or CastIINode).
1383 // Return a default value if there is no apparent constant here.
1384 const TypeInt* Node::find_int_type() const {
1385 if (this->is_Type()) {
1386 return this->as_Type()->type()->isa_int();
1387 } else if (this->is_Con()) {
1388 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1389 return this->bottom_type()->isa_int();
1390 }
1391 return NULL;
1392 }
1393
1394 // Get a pointer constant from a ConstNode.
1395 // Returns the constant if it is a pointer ConstNode
1396 intptr_t Node::get_ptr() const {
1397 assert( Opcode() == Op_ConP, "" );
1398 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1399 }
1400
1401 // Get a narrow oop constant from a ConNNode.
1402 intptr_t Node::get_narrowcon() const {
1403 assert( Opcode() == Op_ConN, "" );
1404 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1405 }
1406
1407 // Get a long constant from a ConNode.
1408 // Return a default value if there is no apparent constant here.
1409 const TypeLong* Node::find_long_type() const {
1410 if (this->is_Type()) {
1411 return this->as_Type()->type()->isa_long();
1412 } else if (this->is_Con()) {
1413 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1414 return this->bottom_type()->isa_long();
1415 }
1416 return NULL;
1417 }
1418
1419
1420 /**
1421 * Return a ptr type for nodes which should have it.
1422 */
1423 const TypePtr* Node::get_ptr_type() const {
1424 const TypePtr* tp = this->bottom_type()->make_ptr();
1425 #ifdef ASSERT
1426 if (tp == NULL) {
1427 this->dump(1);
1428 assert((tp != NULL), "unexpected node type");
1429 }
1430 #endif
1431 return tp;
1432 }
1433
1434 // Get a double constant from a ConstNode.
1435 // Returns the constant if it is a double ConstNode
1436 jdouble Node::getd() const {
1437 assert( Opcode() == Op_ConD, "" );
1438 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1439 }
1440
1441 // Get a float constant from a ConstNode.
1442 // Returns the constant if it is a float ConstNode
1443 jfloat Node::getf() const {
1444 assert( Opcode() == Op_ConF, "" );
1445 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1446 }
1447
1448 #ifndef PRODUCT
1449
1450 //----------------------------NotANode----------------------------------------
1451 // Used in debugging code to avoid walking across dead or uninitialized edges.
1452 static inline bool NotANode(const Node* n) {
1453 if (n == NULL) return true;
1454 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1455 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1456 return false;
1457 }
1458
1459
1460 //------------------------------find------------------------------------------
1461 // Find a neighbor of this Node with the given _idx
1462 // If idx is negative, find its absolute value, following both _in and _out.
1463 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1464 VectorSet* old_space, VectorSet* new_space ) {
1465 int node_idx = (idx >= 0) ? idx : -idx;
1466 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1467 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1468 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1469 if( v->test(n->_idx) ) return;
1470 if( (int)n->_idx == node_idx
1471 debug_only(|| n->debug_idx() == node_idx) ) {
1472 if (result != NULL)
1473 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1474 (uintptr_t)result, (uintptr_t)n, node_idx);
1475 result = n;
1476 }
1477 v->set(n->_idx);
1478 for( uint i=0; i<n->len(); i++ ) {
1479 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1480 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1481 }
1482 // Search along forward edges also:
1483 if (idx < 0 && !only_ctrl) {
1484 for( uint j=0; j<n->outcnt(); j++ ) {
1485 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1486 }
1487 }
1488 #ifdef ASSERT
1489 // Search along debug_orig edges last, checking for cycles
1490 Node* orig = n->debug_orig();
1491 if (orig != NULL) {
1492 do {
1493 if (NotANode(orig)) break;
1494 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1495 orig = orig->debug_orig();
1496 } while (orig != NULL && orig != n->debug_orig());
1497 }
1498 #endif //ASSERT
1499 }
1500
1501 // call this from debugger:
1502 Node* find_node(Node* n, int idx) {
1503 return n->find(idx);
1504 }
1505
1506 //------------------------------find-------------------------------------------
1507 Node* Node::find(int idx) const {
1508 ResourceArea *area = Thread::current()->resource_area();
1509 VectorSet old_space(area), new_space(area);
1510 Node* result = NULL;
1511 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1512 return result;
1513 }
1514
1515 //------------------------------find_ctrl--------------------------------------
1516 // Find an ancestor to this node in the control history with given _idx
1517 Node* Node::find_ctrl(int idx) const {
1518 ResourceArea *area = Thread::current()->resource_area();
1519 VectorSet old_space(area), new_space(area);
1520 Node* result = NULL;
1521 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1522 return result;
1523 }
1524 #endif
1525
1526
1527
1528 #ifndef PRODUCT
1529 int Node::_in_dump_cnt = 0;
1530
1531 // -----------------------------Name-------------------------------------------
1532 extern const char *NodeClassNames[];
1533 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1534
1535 static bool is_disconnected(const Node* n) {
1536 for (uint i = 0; i < n->req(); i++) {
1537 if (n->in(i) != NULL) return false;
1538 }
1539 return true;
1540 }
1541
1542 #ifdef ASSERT
1543 static void dump_orig(Node* orig, outputStream *st) {
1544 Compile* C = Compile::current();
1545 if (NotANode(orig)) orig = NULL;
1546 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1547 if (orig == NULL) return;
1548 st->print(" !orig=");
1549 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1550 if (NotANode(fast)) fast = NULL;
1551 while (orig != NULL) {
1552 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1553 if (discon) st->print("[");
1554 if (!Compile::current()->node_arena()->contains(orig))
1555 st->print("o");
1556 st->print("%d", orig->_idx);
1557 if (discon) st->print("]");
1558 orig = orig->debug_orig();
1559 if (NotANode(orig)) orig = NULL;
1560 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1561 if (orig != NULL) st->print(",");
1562 if (fast != NULL) {
1563 // Step fast twice for each single step of orig:
1564 fast = fast->debug_orig();
1565 if (NotANode(fast)) fast = NULL;
1566 if (fast != NULL && fast != orig) {
1567 fast = fast->debug_orig();
1568 if (NotANode(fast)) fast = NULL;
1569 }
1570 if (fast == orig) {
1571 st->print("...");
1572 break;
1573 }
1574 }
1575 }
1576 }
1577
1578 void Node::set_debug_orig(Node* orig) {
1579 _debug_orig = orig;
1580 if (BreakAtNode == 0) return;
1581 if (NotANode(orig)) orig = NULL;
1582 int trip = 10;
1583 while (orig != NULL) {
1584 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1585 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1586 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1587 BREAKPOINT;
1588 }
1589 orig = orig->debug_orig();
1590 if (NotANode(orig)) orig = NULL;
1591 if (trip-- <= 0) break;
1592 }
1593 }
1594 #endif //ASSERT
1595
1596 //------------------------------dump------------------------------------------
1597 // Dump a Node
1598 void Node::dump(const char* suffix, outputStream *st) const {
1599 Compile* C = Compile::current();
1600 bool is_new = C->node_arena()->contains(this);
1601 _in_dump_cnt++;
1602 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1603
1604 // Dump the required and precedence inputs
1605 dump_req(st);
1606 dump_prec(st);
1607 // Dump the outputs
1608 dump_out(st);
1609
1610 if (is_disconnected(this)) {
1611 #ifdef ASSERT
1612 st->print(" [%d]",debug_idx());
1613 dump_orig(debug_orig(), st);
1614 #endif
1615 st->cr();
1616 _in_dump_cnt--;
1617 return; // don't process dead nodes
1618 }
1619
1620 // Dump node-specific info
1621 dump_spec(st);
1622 #ifdef ASSERT
1623 // Dump the non-reset _debug_idx
1624 if (Verbose && WizardMode) {
1625 st->print(" [%d]",debug_idx());
1626 }
1627 #endif
1628
1629 const Type *t = bottom_type();
1630
1631 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1632 const TypeInstPtr *toop = t->isa_instptr();
1633 const TypeKlassPtr *tkls = t->isa_klassptr();
1634 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1635 if (klass && klass->is_loaded() && klass->is_interface()) {
1636 st->print(" Interface:");
1637 } else if (toop) {
1638 st->print(" Oop:");
1639 } else if (tkls) {
1640 st->print(" Klass:");
1641 }
1642 t->dump_on(st);
1643 } else if (t == Type::MEMORY) {
1644 st->print(" Memory:");
1645 MemNode::dump_adr_type(this, adr_type(), st);
1646 } else if (Verbose || WizardMode) {
1647 st->print(" Type:");
1648 if (t) {
1649 t->dump_on(st);
1650 } else {
1651 st->print("no type");
1652 }
1653 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1654 // Dump MachSpillcopy vector type.
1655 t->dump_on(st);
1656 }
1657 if (is_new) {
1658 debug_only(dump_orig(debug_orig(), st));
1659 Node_Notes* nn = C->node_notes_at(_idx);
1660 if (nn != NULL && !nn->is_clear()) {
1661 if (nn->jvms() != NULL) {
1662 st->print(" !jvms:");
1663 nn->jvms()->dump_spec(st);
1664 }
1665 }
1666 }
1667 if (suffix) st->print(suffix);
1668 _in_dump_cnt--;
1669 }
1670
1671 //------------------------------dump_req--------------------------------------
1672 void Node::dump_req(outputStream *st) const {
1673 // Dump the required input edges
1674 for (uint i = 0; i < req(); i++) { // For all required inputs
1675 Node* d = in(i);
1676 if (d == NULL) {
1677 st->print("_ ");
1678 } else if (NotANode(d)) {
1679 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1680 } else {
1681 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1682 }
1683 }
1684 }
1685
1686
1687 //------------------------------dump_prec-------------------------------------
1688 void Node::dump_prec(outputStream *st) const {
1689 // Dump the precedence edges
1690 int any_prec = 0;
1691 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1692 Node* p = in(i);
1693 if (p != NULL) {
1694 if (!any_prec++) st->print(" |");
1695 if (NotANode(p)) { st->print("NotANode "); continue; }
1696 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1697 }
1698 }
1699 }
1700
1701 //------------------------------dump_out--------------------------------------
1702 void Node::dump_out(outputStream *st) const {
1703 // Delimit the output edges
1704 st->print(" [[");
1705 // Dump the output edges
1706 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1707 Node* u = _out[i];
1708 if (u == NULL) {
1709 st->print("_ ");
1710 } else if (NotANode(u)) {
1711 st->print("NotANode ");
1712 } else {
1713 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1714 }
1715 }
1716 st->print("]] ");
1717 }
1718
1719 //------------------------------dump_nodes-------------------------------------
1720 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1721 Node* s = (Node*)start; // remove const
1722 if (NotANode(s)) return;
1723
1724 uint depth = (uint)ABS(d);
1725 int direction = d;
1726 Compile* C = Compile::current();
1727 GrowableArray <Node *> nstack(C->unique());
1728
1729 nstack.append(s);
1730 int begin = 0;
1731 int end = 0;
1732 for(uint i = 0; i < depth; i++) {
1733 end = nstack.length();
1734 for(int j = begin; j < end; j++) {
1735 Node* tp = nstack.at(j);
1736 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1737 for(uint k = 0; k < limit; k++) {
1738 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1739
1740 if (NotANode(n)) continue;
1741 // do not recurse through top or the root (would reach unrelated stuff)
1742 if (n->is_Root() || n->is_top()) continue;
1743 if (only_ctrl && !n->is_CFG()) continue;
1744
1745 bool on_stack = nstack.contains(n);
1746 if (!on_stack) {
1747 nstack.append(n);
1748 }
1749 }
1750 }
1751 begin = end;
1752 }
1753 end = nstack.length();
1754 if (direction > 0) {
1755 for(int j = end-1; j >= 0; j--) {
1756 nstack.at(j)->dump();
1757 }
1758 } else {
1759 for(int j = 0; j < end; j++) {
1760 nstack.at(j)->dump();
1761 }
1762 }
1763 }
1764
1765 //------------------------------dump-------------------------------------------
1766 void Node::dump(int d) const {
1767 dump_nodes(this, d, false);
1768 }
1769
1770 //------------------------------dump_ctrl--------------------------------------
1771 // Dump a Node's control history to depth
1772 void Node::dump_ctrl(int d) const {
1773 dump_nodes(this, d, true);
1774 }
1775
1776 // VERIFICATION CODE
1777 // For each input edge to a node (ie - for each Use-Def edge), verify that
1778 // there is a corresponding Def-Use edge.
1779 //------------------------------verify_edges-----------------------------------
1780 void Node::verify_edges(Unique_Node_List &visited) {
1781 uint i, j, idx;
1782 int cnt;
1783 Node *n;
1784
1785 // Recursive termination test
1786 if (visited.member(this)) return;
1787 visited.push(this);
1788
1789 // Walk over all input edges, checking for correspondence
1790 for( i = 0; i < len(); i++ ) {
1791 n = in(i);
1792 if (n != NULL && !n->is_top()) {
1793 // Count instances of (Node *)this
1794 cnt = 0;
1795 for (idx = 0; idx < n->_outcnt; idx++ ) {
1796 if (n->_out[idx] == (Node *)this) cnt++;
1797 }
1798 assert( cnt > 0,"Failed to find Def-Use edge." );
1799 // Check for duplicate edges
1800 // walk the input array downcounting the input edges to n
1801 for( j = 0; j < len(); j++ ) {
1802 if( in(j) == n ) cnt--;
1803 }
1804 assert( cnt == 0,"Mismatched edge count.");
1805 } else if (n == NULL) {
1806 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1807 } else {
1808 assert(n->is_top(), "sanity");
1809 // Nothing to check.
1810 }
1811 }
1812 // Recursive walk over all input edges
1813 for( i = 0; i < len(); i++ ) {
1814 n = in(i);
1815 if( n != NULL )
1816 in(i)->verify_edges(visited);
1817 }
1818 }
1819
1820 //------------------------------verify_recur-----------------------------------
1821 static const Node *unique_top = NULL;
1822
1823 void Node::verify_recur(const Node *n, int verify_depth,
1824 VectorSet &old_space, VectorSet &new_space) {
1825 if ( verify_depth == 0 ) return;
1826 if (verify_depth > 0) --verify_depth;
1827
1828 Compile* C = Compile::current();
1829
1830 // Contained in new_space or old_space?
1831 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1832 // Check for visited in the proper space. Numberings are not unique
1833 // across spaces so we need a separate VectorSet for each space.
1834 if( v->test_set(n->_idx) ) return;
1835
1836 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1837 if (C->cached_top_node() == NULL)
1838 C->set_cached_top_node((Node*)n);
1839 assert(C->cached_top_node() == n, "TOP node must be unique");
1840 }
1841
1842 for( uint i = 0; i < n->len(); i++ ) {
1843 Node *x = n->in(i);
1844 if (!x || x->is_top()) continue;
1845
1846 // Verify my input has a def-use edge to me
1847 if (true /*VerifyDefUse*/) {
1848 // Count use-def edges from n to x
1849 int cnt = 0;
1850 for( uint j = 0; j < n->len(); j++ )
1851 if( n->in(j) == x )
1852 cnt++;
1853 // Count def-use edges from x to n
1854 uint max = x->_outcnt;
1855 for( uint k = 0; k < max; k++ )
1856 if (x->_out[k] == n)
1857 cnt--;
1858 assert( cnt == 0, "mismatched def-use edge counts" );
1859 }
1860
1861 verify_recur(x, verify_depth, old_space, new_space);
1862 }
1863
1864 }
1865
1866 //------------------------------verify-----------------------------------------
1867 // Check Def-Use info for my subgraph
1868 void Node::verify() const {
1869 Compile* C = Compile::current();
1870 Node* old_top = C->cached_top_node();
1871 ResourceMark rm;
1872 ResourceArea *area = Thread::current()->resource_area();
1873 VectorSet old_space(area), new_space(area);
1874 verify_recur(this, -1, old_space, new_space);
1875 C->set_cached_top_node(old_top);
1876 }
1877 #endif
1878
1879
1880 //------------------------------walk-------------------------------------------
1881 // Graph walk, with both pre-order and post-order functions
1882 void Node::walk(NFunc pre, NFunc post, void *env) {
1883 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1884 walk_(pre, post, env, visited);
1885 }
1886
1887 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1888 if( visited.test_set(_idx) ) return;
1889 pre(*this,env); // Call the pre-order walk function
1890 for( uint i=0; i<_max; i++ )
1891 if( in(i) ) // Input exists and is not walked?
1892 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1893 post(*this,env); // Call the post-order walk function
1894 }
1895
1896 void Node::nop(Node &, void*) {}
1897
1898 //------------------------------Registers--------------------------------------
1899 // Do we Match on this edge index or not? Generally false for Control
1900 // and true for everything else. Weird for calls & returns.
1901 uint Node::match_edge(uint idx) const {
1902 return idx; // True for other than index 0 (control)
1903 }
1904
1905 static RegMask _not_used_at_all;
1906 // Register classes are defined for specific machines
1907 const RegMask &Node::out_RegMask() const {
1908 ShouldNotCallThis();
1909 return _not_used_at_all;
1910 }
1911
1912 const RegMask &Node::in_RegMask(uint) const {
1913 ShouldNotCallThis();
1914 return _not_used_at_all;
1915 }
1916
1917 //=============================================================================
1918 //-----------------------------------------------------------------------------
1919 void Node_Array::reset( Arena *new_arena ) {
1920 _a->Afree(_nodes,_max*sizeof(Node*));
1921 _max = 0;
1922 _nodes = NULL;
1923 _a = new_arena;
1924 }
1925
1926 //------------------------------clear------------------------------------------
1927 // Clear all entries in _nodes to NULL but keep storage
1928 void Node_Array::clear() {
1929 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1930 }
1931
1932 //-----------------------------------------------------------------------------
1933 void Node_Array::grow( uint i ) {
1934 if( !_max ) {
1935 _max = 1;
1936 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1937 _nodes[0] = NULL;
1938 }
1939 uint old = _max;
1940 while( i >= _max ) _max <<= 1; // Double to fit
1941 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1942 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1943 }
1944
1945 //-----------------------------------------------------------------------------
1946 void Node_Array::insert( uint i, Node *n ) {
1947 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1948 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1949 _nodes[i] = n;
1950 }
1951
1952 //-----------------------------------------------------------------------------
1953 void Node_Array::remove( uint i ) {
1954 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1955 _nodes[_max-1] = NULL;
1956 }
1957
1958 //-----------------------------------------------------------------------------
1959 void Node_Array::sort( C_sort_func_t func) {
1960 qsort( _nodes, _max, sizeof( Node* ), func );
1961 }
1962
1963 //-----------------------------------------------------------------------------
1964 void Node_Array::dump() const {
1965 #ifndef PRODUCT
1966 for( uint i = 0; i < _max; i++ ) {
1967 Node *nn = _nodes[i];
1968 if( nn != NULL ) {
1969 tty->print("%5d--> ",i); nn->dump();
1970 }
1971 }
1972 #endif
1973 }
1974
1975 //--------------------------is_iteratively_computed------------------------------
1976 // Operation appears to be iteratively computed (such as an induction variable)
1977 // It is possible for this operation to return false for a loop-varying
1978 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1979 bool Node::is_iteratively_computed() {
1980 if (ideal_reg()) { // does operation have a result register?
1981 for (uint i = 1; i < req(); i++) {
1982 Node* n = in(i);
1983 if (n != NULL && n->is_Phi()) {
1984 for (uint j = 1; j < n->req(); j++) {
1985 if (n->in(j) == this) {
1986 return true;
1987 }
1988 }
1989 }
1990 }
1991 }
1992 return false;
1993 }
1994
1995 //--------------------------find_similar------------------------------
1996 // Return a node with opcode "opc" and same inputs as "this" if one can
1997 // be found; Otherwise return NULL;
1998 Node* Node::find_similar(int opc) {
1999 if (req() >= 2) {
2000 Node* def = in(1);
2001 if (def && def->outcnt() >= 2) {
2002 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2003 Node* use = def->fast_out(i);
2004 if (use->Opcode() == opc &&
2005 use->req() == req()) {
2006 uint j;
2007 for (j = 0; j < use->req(); j++) {
2008 if (use->in(j) != in(j)) {
2009 break;
2010 }
2011 }
2012 if (j == use->req()) {
2013 return use;
2014 }
2015 }
2016 }
2017 }
2018 }
2019 return NULL;
2020 }
2021
2022
2023 //--------------------------unique_ctrl_out------------------------------
2024 // Return the unique control out if only one. Null if none or more than one.
2025 Node* Node::unique_ctrl_out() {
2026 Node* found = NULL;
2027 for (uint i = 0; i < outcnt(); i++) {
2028 Node* use = raw_out(i);
2029 if (use->is_CFG() && use != this) {
2030 if (found != NULL) return NULL;
2031 found = use;
2032 }
2033 }
2034 return found;
2035 }
2036
2037 //=============================================================================
2038 //------------------------------yank-------------------------------------------
2039 // Find and remove
2040 void Node_List::yank( Node *n ) {
2041 uint i;
2042 for( i = 0; i < _cnt; i++ )
2043 if( _nodes[i] == n )
2044 break;
2045
2046 if( i < _cnt )
2047 _nodes[i] = _nodes[--_cnt];
2048 }
2049
2050 //------------------------------dump-------------------------------------------
2051 void Node_List::dump() const {
2052 #ifndef PRODUCT
2053 for( uint i = 0; i < _cnt; i++ )
2054 if( _nodes[i] ) {
2055 tty->print("%5d--> ",i);
2056 _nodes[i]->dump();
2057 }
2058 #endif
2059 }
2060
2061 //=============================================================================
2062 //------------------------------remove-----------------------------------------
2063 void Unique_Node_List::remove( Node *n ) {
2064 if( _in_worklist[n->_idx] ) {
2065 for( uint i = 0; i < size(); i++ )
2066 if( _nodes[i] == n ) {
2067 map(i,Node_List::pop());
2068 _in_worklist >>= n->_idx;
2069 return;
2070 }
2071 ShouldNotReachHere();
2072 }
2073 }
2074
2075 //-----------------------remove_useless_nodes----------------------------------
2076 // Remove useless nodes from worklist
2077 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2078
2079 for( uint i = 0; i < size(); ++i ) {
2080 Node *n = at(i);
2081 assert( n != NULL, "Did not expect null entries in worklist");
2082 if( ! useful.test(n->_idx) ) {
2083 _in_worklist >>= n->_idx;
2084 map(i,Node_List::pop());
2085 // Node *replacement = Node_List::pop();
2086 // if( i != size() ) { // Check if removing last entry
2087 // _nodes[i] = replacement;
2088 // }
2089 --i; // Visit popped node
2090 // If it was last entry, loop terminates since size() was also reduced
2091 }
2092 }
2093 }
2094
2095 //=============================================================================
2096 void Node_Stack::grow() {
2097 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2098 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2099 size_t max = old_max << 1; // max * 2
2100 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2101 _inode_max = _inodes + max;
2102 _inode_top = _inodes + old_top; // restore _top
2103 }
2104
2105 // Node_Stack is used to map nodes.
2106 Node* Node_Stack::find(uint idx) const {
2107 uint sz = size();
2108 for (uint i=0; i < sz; i++) {
2109 if (idx == index_at(i) )
2110 return node_at(i);
2111 }
2112 return NULL;
2113 }
2114
2115 //=============================================================================
2116 uint TypeNode::size_of() const { return sizeof(*this); }
2117 #ifndef PRODUCT
2118 void TypeNode::dump_spec(outputStream *st) const {
2119 if( !Verbose && !WizardMode ) {
2120 // standard dump does this in Verbose and WizardMode
2121 st->print(" #"); _type->dump_on(st);
2122 }
2123 }
2124 #endif
2125 uint TypeNode::hash() const {
2126 return Node::hash() + _type->hash();
2127 }
2128 uint TypeNode::cmp( const Node &n ) const
2129 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2130 const Type *TypeNode::bottom_type() const { return _type; }
2131 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2132
2133 //------------------------------ideal_reg--------------------------------------
2134 uint TypeNode::ideal_reg() const {
2135 return _type->ideal_reg();
2136 }