Thu, 15 May 2008 22:43:11 -0700
6701887: JDK7 server VM in endless loop in Node::dominates
Summary: The method Node::dominates loops in the dead code which does not have a Region node.
Reviewed-by: jrose, never
1 /*
2 * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 #include "incls/_precompiled.incl"
26 #include "incls/_node.cpp.incl"
28 class RegMask;
29 // #include "phase.hpp"
30 class PhaseTransform;
31 class PhaseGVN;
33 // Arena we are currently building Nodes in
34 const uint Node::NotAMachineReg = 0xffff0000;
36 #ifndef PRODUCT
37 extern int nodes_created;
38 #endif
40 #ifdef ASSERT
42 //-------------------------- construct_node------------------------------------
43 // Set a breakpoint here to identify where a particular node index is built.
44 void Node::verify_construction() {
45 _debug_orig = NULL;
46 int old_debug_idx = Compile::debug_idx();
47 int new_debug_idx = old_debug_idx+1;
48 if (new_debug_idx > 0) {
49 // Arrange that the lowest five decimal digits of _debug_idx
50 // will repeat thos of _idx. In case this is somehow pathological,
51 // we continue to assign negative numbers (!) consecutively.
52 const int mod = 100000;
53 int bump = (int)(_idx - new_debug_idx) % mod;
54 if (bump < 0) bump += mod;
55 assert(bump >= 0 && bump < mod, "");
56 new_debug_idx += bump;
57 }
58 Compile::set_debug_idx(new_debug_idx);
59 set_debug_idx( new_debug_idx );
60 assert(Compile::current()->unique() < (uint)MaxNodeLimit, "Node limit exceeded");
61 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
62 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
63 BREAKPOINT;
64 }
65 #if OPTO_DU_ITERATOR_ASSERT
66 _last_del = NULL;
67 _del_tick = 0;
68 #endif
69 _hash_lock = 0;
70 }
73 // #ifdef ASSERT ...
75 #if OPTO_DU_ITERATOR_ASSERT
76 void DUIterator_Common::sample(const Node* node) {
77 _vdui = VerifyDUIterators;
78 _node = node;
79 _outcnt = node->_outcnt;
80 _del_tick = node->_del_tick;
81 _last = NULL;
82 }
84 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
85 assert(_node == node, "consistent iterator source");
86 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
87 }
89 void DUIterator_Common::verify_resync() {
90 // Ensure that the loop body has just deleted the last guy produced.
91 const Node* node = _node;
92 // Ensure that at least one copy of the last-seen edge was deleted.
93 // Note: It is OK to delete multiple copies of the last-seen edge.
94 // Unfortunately, we have no way to verify that all the deletions delete
95 // that same edge. On this point we must use the Honor System.
96 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
97 assert(node->_last_del == _last, "must have deleted the edge just produced");
98 // We liked this deletion, so accept the resulting outcnt and tick.
99 _outcnt = node->_outcnt;
100 _del_tick = node->_del_tick;
101 }
103 void DUIterator_Common::reset(const DUIterator_Common& that) {
104 if (this == &that) return; // ignore assignment to self
105 if (!_vdui) {
106 // We need to initialize everything, overwriting garbage values.
107 _last = that._last;
108 _vdui = that._vdui;
109 }
110 // Note: It is legal (though odd) for an iterator over some node x
111 // to be reassigned to iterate over another node y. Some doubly-nested
112 // progress loops depend on being able to do this.
113 const Node* node = that._node;
114 // Re-initialize everything, except _last.
115 _node = node;
116 _outcnt = node->_outcnt;
117 _del_tick = node->_del_tick;
118 }
120 void DUIterator::sample(const Node* node) {
121 DUIterator_Common::sample(node); // Initialize the assertion data.
122 _refresh_tick = 0; // No refreshes have happened, as yet.
123 }
125 void DUIterator::verify(const Node* node, bool at_end_ok) {
126 DUIterator_Common::verify(node, at_end_ok);
127 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
128 }
130 void DUIterator::verify_increment() {
131 if (_refresh_tick & 1) {
132 // We have refreshed the index during this loop.
133 // Fix up _idx to meet asserts.
134 if (_idx > _outcnt) _idx = _outcnt;
135 }
136 verify(_node, true);
137 }
139 void DUIterator::verify_resync() {
140 // Note: We do not assert on _outcnt, because insertions are OK here.
141 DUIterator_Common::verify_resync();
142 // Make sure we are still in sync, possibly with no more out-edges:
143 verify(_node, true);
144 }
146 void DUIterator::reset(const DUIterator& that) {
147 if (this == &that) return; // self assignment is always a no-op
148 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
149 assert(that._idx == 0, "assign only the result of Node::outs()");
150 assert(_idx == that._idx, "already assigned _idx");
151 if (!_vdui) {
152 // We need to initialize everything, overwriting garbage values.
153 sample(that._node);
154 } else {
155 DUIterator_Common::reset(that);
156 if (_refresh_tick & 1) {
157 _refresh_tick++; // Clear the "was refreshed" flag.
158 }
159 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
160 }
161 }
163 void DUIterator::refresh() {
164 DUIterator_Common::sample(_node); // Re-fetch assertion data.
165 _refresh_tick |= 1; // Set the "was refreshed" flag.
166 }
168 void DUIterator::verify_finish() {
169 // If the loop has killed the node, do not require it to re-run.
170 if (_node->_outcnt == 0) _refresh_tick &= ~1;
171 // If this assert triggers, it means that a loop used refresh_out_pos
172 // to re-synch an iteration index, but the loop did not correctly
173 // re-run itself, using a "while (progress)" construct.
174 // This iterator enforces the rule that you must keep trying the loop
175 // until it "runs clean" without any need for refreshing.
176 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
177 }
180 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
181 DUIterator_Common::verify(node, at_end_ok);
182 Node** out = node->_out;
183 uint cnt = node->_outcnt;
184 assert(cnt == _outcnt, "no insertions allowed");
185 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
186 // This last check is carefully designed to work for NO_OUT_ARRAY.
187 }
189 void DUIterator_Fast::verify_limit() {
190 const Node* node = _node;
191 verify(node, true);
192 assert(_outp == node->_out + node->_outcnt, "limit still correct");
193 }
195 void DUIterator_Fast::verify_resync() {
196 const Node* node = _node;
197 if (_outp == node->_out + _outcnt) {
198 // Note that the limit imax, not the pointer i, gets updated with the
199 // exact count of deletions. (For the pointer it's always "--i".)
200 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
201 // This is a limit pointer, with a name like "imax".
202 // Fudge the _last field so that the common assert will be happy.
203 _last = (Node*) node->_last_del;
204 DUIterator_Common::verify_resync();
205 } else {
206 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
207 // A normal internal pointer.
208 DUIterator_Common::verify_resync();
209 // Make sure we are still in sync, possibly with no more out-edges:
210 verify(node, true);
211 }
212 }
214 void DUIterator_Fast::verify_relimit(uint n) {
215 const Node* node = _node;
216 assert((int)n > 0, "use imax -= n only with a positive count");
217 // This must be a limit pointer, with a name like "imax".
218 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
219 // The reported number of deletions must match what the node saw.
220 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
221 // Fudge the _last field so that the common assert will be happy.
222 _last = (Node*) node->_last_del;
223 DUIterator_Common::verify_resync();
224 }
226 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
227 assert(_outp == that._outp, "already assigned _outp");
228 DUIterator_Common::reset(that);
229 }
231 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
232 // at_end_ok means the _outp is allowed to underflow by 1
233 _outp += at_end_ok;
234 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
235 _outp -= at_end_ok;
236 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
237 }
239 void DUIterator_Last::verify_limit() {
240 // Do not require the limit address to be resynched.
241 //verify(node, true);
242 assert(_outp == _node->_out, "limit still correct");
243 }
245 void DUIterator_Last::verify_step(uint num_edges) {
246 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
247 _outcnt -= num_edges;
248 _del_tick += num_edges;
249 // Make sure we are still in sync, possibly with no more out-edges:
250 const Node* node = _node;
251 verify(node, true);
252 assert(node->_last_del == _last, "must have deleted the edge just produced");
253 }
255 #endif //OPTO_DU_ITERATOR_ASSERT
258 #endif //ASSERT
261 // This constant used to initialize _out may be any non-null value.
262 // The value NULL is reserved for the top node only.
263 #define NO_OUT_ARRAY ((Node**)-1)
265 // This funny expression handshakes with Node::operator new
266 // to pull Compile::current out of the new node's _out field,
267 // and then calls a subroutine which manages most field
268 // initializations. The only one which is tricky is the
269 // _idx field, which is const, and so must be initialized
270 // by a return value, not an assignment.
271 //
272 // (Aren't you thankful that Java finals don't require so many tricks?)
273 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
274 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
275 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
276 #endif
278 // Out-of-line code from node constructors.
279 // Executed only when extra debug info. is being passed around.
280 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
281 C->set_node_notes_at(idx, nn);
282 }
284 // Shared initialization code.
285 inline int Node::Init(int req, Compile* C) {
286 assert(Compile::current() == C, "must use operator new(Compile*)");
287 int idx = C->next_unique();
289 // If there are default notes floating around, capture them:
290 Node_Notes* nn = C->default_node_notes();
291 if (nn != NULL) init_node_notes(C, idx, nn);
293 // Note: At this point, C is dead,
294 // and we begin to initialize the new Node.
296 _cnt = _max = req;
297 _outcnt = _outmax = 0;
298 _class_id = Class_Node;
299 _flags = 0;
300 _out = NO_OUT_ARRAY;
301 return idx;
302 }
304 //------------------------------Node-------------------------------------------
305 // Create a Node, with a given number of required edges.
306 Node::Node(uint req)
307 : _idx(IDX_INIT(req))
308 {
309 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
310 debug_only( verify_construction() );
311 NOT_PRODUCT(nodes_created++);
312 if (req == 0) {
313 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
314 _in = NULL;
315 } else {
316 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
317 Node** to = _in;
318 for(uint i = 0; i < req; i++) {
319 to[i] = NULL;
320 }
321 }
322 }
324 //------------------------------Node-------------------------------------------
325 Node::Node(Node *n0)
326 : _idx(IDX_INIT(1))
327 {
328 debug_only( verify_construction() );
329 NOT_PRODUCT(nodes_created++);
330 // Assert we allocated space for input array already
331 assert( _in[0] == this, "Must pass arg count to 'new'" );
332 assert( is_not_dead(n0), "can not use dead node");
333 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
334 }
336 //------------------------------Node-------------------------------------------
337 Node::Node(Node *n0, Node *n1)
338 : _idx(IDX_INIT(2))
339 {
340 debug_only( verify_construction() );
341 NOT_PRODUCT(nodes_created++);
342 // Assert we allocated space for input array already
343 assert( _in[1] == this, "Must pass arg count to 'new'" );
344 assert( is_not_dead(n0), "can not use dead node");
345 assert( is_not_dead(n1), "can not use dead node");
346 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
347 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
348 }
350 //------------------------------Node-------------------------------------------
351 Node::Node(Node *n0, Node *n1, Node *n2)
352 : _idx(IDX_INIT(3))
353 {
354 debug_only( verify_construction() );
355 NOT_PRODUCT(nodes_created++);
356 // Assert we allocated space for input array already
357 assert( _in[2] == this, "Must pass arg count to 'new'" );
358 assert( is_not_dead(n0), "can not use dead node");
359 assert( is_not_dead(n1), "can not use dead node");
360 assert( is_not_dead(n2), "can not use dead node");
361 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
362 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
363 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
364 }
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
368 : _idx(IDX_INIT(4))
369 {
370 debug_only( verify_construction() );
371 NOT_PRODUCT(nodes_created++);
372 // Assert we allocated space for input array already
373 assert( _in[3] == this, "Must pass arg count to 'new'" );
374 assert( is_not_dead(n0), "can not use dead node");
375 assert( is_not_dead(n1), "can not use dead node");
376 assert( is_not_dead(n2), "can not use dead node");
377 assert( is_not_dead(n3), "can not use dead node");
378 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
379 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
380 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
381 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
382 }
384 //------------------------------Node-------------------------------------------
385 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
386 : _idx(IDX_INIT(5))
387 {
388 debug_only( verify_construction() );
389 NOT_PRODUCT(nodes_created++);
390 // Assert we allocated space for input array already
391 assert( _in[4] == 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 assert( is_not_dead(n4), "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 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
402 }
404 //------------------------------Node-------------------------------------------
405 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
406 Node *n4, Node *n5)
407 : _idx(IDX_INIT(6))
408 {
409 debug_only( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 // Assert we allocated space for input array already
412 assert( _in[5] == this, "Must pass arg count to 'new'" );
413 assert( is_not_dead(n0), "can not use dead node");
414 assert( is_not_dead(n1), "can not use dead node");
415 assert( is_not_dead(n2), "can not use dead node");
416 assert( is_not_dead(n3), "can not use dead node");
417 assert( is_not_dead(n4), "can not use dead node");
418 assert( is_not_dead(n5), "can not use dead node");
419 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
420 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
421 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
422 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
423 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
424 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
425 }
427 //------------------------------Node-------------------------------------------
428 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
429 Node *n4, Node *n5, Node *n6)
430 : _idx(IDX_INIT(7))
431 {
432 debug_only( verify_construction() );
433 NOT_PRODUCT(nodes_created++);
434 // Assert we allocated space for input array already
435 assert( _in[6] == this, "Must pass arg count to 'new'" );
436 assert( is_not_dead(n0), "can not use dead node");
437 assert( is_not_dead(n1), "can not use dead node");
438 assert( is_not_dead(n2), "can not use dead node");
439 assert( is_not_dead(n3), "can not use dead node");
440 assert( is_not_dead(n4), "can not use dead node");
441 assert( is_not_dead(n5), "can not use dead node");
442 assert( is_not_dead(n6), "can not use dead node");
443 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
444 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
445 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
446 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
447 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
448 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
449 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
450 }
453 //------------------------------clone------------------------------------------
454 // Clone a Node.
455 Node *Node::clone() const {
456 Compile *compile = Compile::current();
457 uint s = size_of(); // Size of inherited Node
458 Node *n = (Node*)compile->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
459 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
460 // Set the new input pointer array
461 n->_in = (Node**)(((char*)n)+s);
462 // Cannot share the old output pointer array, so kill it
463 n->_out = NO_OUT_ARRAY;
464 // And reset the counters to 0
465 n->_outcnt = 0;
466 n->_outmax = 0;
467 // Unlock this guy, since he is not in any hash table.
468 debug_only(n->_hash_lock = 0);
469 // Walk the old node's input list to duplicate its edges
470 uint i;
471 for( i = 0; i < len(); i++ ) {
472 Node *x = in(i);
473 n->_in[i] = x;
474 if (x != NULL) x->add_out(n);
475 }
476 if (is_macro())
477 compile->add_macro_node(n);
479 n->set_idx(compile->next_unique()); // Get new unique index as well
480 debug_only( n->verify_construction() );
481 NOT_PRODUCT(nodes_created++);
482 // Do not patch over the debug_idx of a clone, because it makes it
483 // impossible to break on the clone's moment of creation.
484 //debug_only( n->set_debug_idx( debug_idx() ) );
486 compile->copy_node_notes_to(n, (Node*) this);
488 // MachNode clone
489 uint nopnds;
490 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
491 MachNode *mach = n->as_Mach();
492 MachNode *mthis = this->as_Mach();
493 // Get address of _opnd_array.
494 // It should be the same offset since it is the clone of this node.
495 MachOper **from = mthis->_opnds;
496 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
497 pointer_delta((const void*)from,
498 (const void*)(&mthis->_opnds), 1));
499 mach->_opnds = to;
500 for ( uint i = 0; i < nopnds; ++i ) {
501 to[i] = from[i]->clone(compile);
502 }
503 }
504 // cloning CallNode may need to clone JVMState
505 if (n->is_Call()) {
506 CallNode *call = n->as_Call();
507 call->clone_jvms();
508 }
509 return n; // Return the clone
510 }
512 //---------------------------setup_is_top--------------------------------------
513 // Call this when changing the top node, to reassert the invariants
514 // required by Node::is_top. See Compile::set_cached_top_node.
515 void Node::setup_is_top() {
516 if (this == (Node*)Compile::current()->top()) {
517 // This node has just become top. Kill its out array.
518 _outcnt = _outmax = 0;
519 _out = NULL; // marker value for top
520 assert(is_top(), "must be top");
521 } else {
522 if (_out == NULL) _out = NO_OUT_ARRAY;
523 assert(!is_top(), "must not be top");
524 }
525 }
528 //------------------------------~Node------------------------------------------
529 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
530 extern int reclaim_idx ;
531 extern int reclaim_in ;
532 extern int reclaim_node;
533 void Node::destruct() {
534 // Eagerly reclaim unique Node numberings
535 Compile* compile = Compile::current();
536 if ((uint)_idx+1 == compile->unique()) {
537 compile->set_unique(compile->unique()-1);
538 #ifdef ASSERT
539 reclaim_idx++;
540 #endif
541 }
542 // Clear debug info:
543 Node_Notes* nn = compile->node_notes_at(_idx);
544 if (nn != NULL) nn->clear();
545 // Walk the input array, freeing the corresponding output edges
546 _cnt = _max; // forget req/prec distinction
547 uint i;
548 for( i = 0; i < _max; i++ ) {
549 set_req(i, NULL);
550 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
551 }
552 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
553 // See if the input array was allocated just prior to the object
554 int edge_size = _max*sizeof(void*);
555 int out_edge_size = _outmax*sizeof(void*);
556 char *edge_end = ((char*)_in) + edge_size;
557 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
558 char *out_edge_end = out_array + out_edge_size;
559 int node_size = size_of();
561 // Free the output edge array
562 if (out_edge_size > 0) {
563 #ifdef ASSERT
564 if( out_edge_end == compile->node_arena()->hwm() )
565 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
566 #endif
567 compile->node_arena()->Afree(out_array, out_edge_size);
568 }
570 // Free the input edge array and the node itself
571 if( edge_end == (char*)this ) {
572 #ifdef ASSERT
573 if( edge_end+node_size == compile->node_arena()->hwm() ) {
574 reclaim_in += edge_size;
575 reclaim_node+= node_size;
576 }
577 #else
578 // It was; free the input array and object all in one hit
579 compile->node_arena()->Afree(_in,edge_size+node_size);
580 #endif
581 } else {
583 // Free just the input array
584 #ifdef ASSERT
585 if( edge_end == compile->node_arena()->hwm() )
586 reclaim_in += edge_size;
587 #endif
588 compile->node_arena()->Afree(_in,edge_size);
590 // Free just the object
591 #ifdef ASSERT
592 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
593 reclaim_node+= node_size;
594 #else
595 compile->node_arena()->Afree(this,node_size);
596 #endif
597 }
598 if (is_macro()) {
599 compile->remove_macro_node(this);
600 }
601 #ifdef ASSERT
602 // We will not actually delete the storage, but we'll make the node unusable.
603 *(address*)this = badAddress; // smash the C++ vtbl, probably
604 _in = _out = (Node**) badAddress;
605 _max = _cnt = _outmax = _outcnt = 0;
606 #endif
607 }
609 //------------------------------grow-------------------------------------------
610 // Grow the input array, making space for more edges
611 void Node::grow( uint len ) {
612 Arena* arena = Compile::current()->node_arena();
613 uint new_max = _max;
614 if( new_max == 0 ) {
615 _max = 4;
616 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
617 Node** to = _in;
618 to[0] = NULL;
619 to[1] = NULL;
620 to[2] = NULL;
621 to[3] = NULL;
622 return;
623 }
624 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
625 // Trimming to limit allows a uint8 to handle up to 255 edges.
626 // Previously I was using only powers-of-2 which peaked at 128 edges.
627 //if( new_max >= limit ) new_max = limit-1;
628 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
629 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
630 _max = new_max; // Record new max length
631 // This assertion makes sure that Node::_max is wide enough to
632 // represent the numerical value of new_max.
633 assert(_max == new_max && _max > len, "int width of _max is too small");
634 }
636 //-----------------------------out_grow----------------------------------------
637 // Grow the input array, making space for more edges
638 void Node::out_grow( uint len ) {
639 assert(!is_top(), "cannot grow a top node's out array");
640 Arena* arena = Compile::current()->node_arena();
641 uint new_max = _outmax;
642 if( new_max == 0 ) {
643 _outmax = 4;
644 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
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 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
652 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
653 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
654 _outmax = new_max; // Record new max length
655 // This assertion makes sure that Node::_max is wide enough to
656 // represent the numerical value of new_max.
657 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
658 }
660 #ifdef ASSERT
661 //------------------------------is_dead----------------------------------------
662 bool Node::is_dead() const {
663 // Mach and pinch point nodes may look like dead.
664 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
665 return false;
666 for( uint i = 0; i < _max; i++ )
667 if( _in[i] != NULL )
668 return false;
669 dump();
670 return true;
671 }
672 #endif
674 //------------------------------add_req----------------------------------------
675 // Add a new required input at the end
676 void Node::add_req( Node *n ) {
677 assert( is_not_dead(n), "can not use dead node");
679 // Look to see if I can move precedence down one without reallocating
680 if( (_cnt >= _max) || (in(_max-1) != NULL) )
681 grow( _max+1 );
683 // Find a precedence edge to move
684 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
685 uint i;
686 for( i=_cnt; i<_max; i++ )
687 if( in(i) == NULL ) // Find the NULL at end of prec edge list
688 break; // There must be one, since we grew the array
689 _in[i] = in(_cnt); // Move prec over, making space for req edge
690 }
691 _in[_cnt++] = n; // Stuff over old prec edge
692 if (n != NULL) n->add_out((Node *)this);
693 }
695 //---------------------------add_req_batch-------------------------------------
696 // Add a new required input at the end
697 void Node::add_req_batch( Node *n, uint m ) {
698 assert( is_not_dead(n), "can not use dead node");
699 // check various edge cases
700 if ((int)m <= 1) {
701 assert((int)m >= 0, "oob");
702 if (m != 0) add_req(n);
703 return;
704 }
706 // Look to see if I can move precedence down one without reallocating
707 if( (_cnt+m) > _max || _in[_max-m] )
708 grow( _max+m );
710 // Find a precedence edge to move
711 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
712 uint i;
713 for( i=_cnt; i<_max; i++ )
714 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
715 break; // There must be one, since we grew the array
716 // Slide all the precs over by m positions (assume #prec << m).
717 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
718 }
720 // Stuff over the old prec edges
721 for(uint i=0; i<m; i++ ) {
722 _in[_cnt++] = n;
723 }
725 // Insert multiple out edges on the node.
726 if (n != NULL && !n->is_top()) {
727 for(uint i=0; i<m; i++ ) {
728 n->add_out((Node *)this);
729 }
730 }
731 }
733 //------------------------------del_req----------------------------------------
734 // Delete the required edge and compact the edge array
735 void Node::del_req( uint idx ) {
736 // First remove corresponding def-use edge
737 Node *n = in(idx);
738 if (n != NULL) n->del_out((Node *)this);
739 _in[idx] = in(--_cnt); // Compact the array
740 _in[_cnt] = NULL; // NULL out emptied slot
741 }
743 //------------------------------ins_req----------------------------------------
744 // Insert a new required input at the end
745 void Node::ins_req( uint idx, Node *n ) {
746 assert( is_not_dead(n), "can not use dead node");
747 add_req(NULL); // Make space
748 assert( idx < _max, "Must have allocated enough space");
749 // Slide over
750 if(_cnt-idx-1 > 0) {
751 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
752 }
753 _in[idx] = n; // Stuff over old required edge
754 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
755 }
757 //-----------------------------find_edge---------------------------------------
758 int Node::find_edge(Node* n) {
759 for (uint i = 0; i < len(); i++) {
760 if (_in[i] == n) return i;
761 }
762 return -1;
763 }
765 //----------------------------replace_edge-------------------------------------
766 int Node::replace_edge(Node* old, Node* neww) {
767 if (old == neww) return 0; // nothing to do
768 uint nrep = 0;
769 for (uint i = 0; i < len(); i++) {
770 if (in(i) == old) {
771 if (i < req())
772 set_req(i, neww);
773 else
774 set_prec(i, neww);
775 nrep++;
776 }
777 }
778 return nrep;
779 }
781 //-------------------------disconnect_inputs-----------------------------------
782 // NULL out all inputs to eliminate incoming Def-Use edges.
783 // Return the number of edges between 'n' and 'this'
784 int Node::disconnect_inputs(Node *n) {
785 int edges_to_n = 0;
787 uint cnt = req();
788 for( uint i = 0; i < cnt; ++i ) {
789 if( in(i) == 0 ) continue;
790 if( in(i) == n ) ++edges_to_n;
791 set_req(i, NULL);
792 }
793 // Remove precedence edges if any exist
794 // Note: Safepoints may have precedence edges, even during parsing
795 if( (req() != len()) && (in(req()) != NULL) ) {
796 uint max = len();
797 for( uint i = 0; i < max; ++i ) {
798 if( in(i) == 0 ) continue;
799 if( in(i) == n ) ++edges_to_n;
800 set_prec(i, NULL);
801 }
802 }
804 // Node::destruct requires all out edges be deleted first
805 // debug_only(destruct();) // no reuse benefit expected
806 return edges_to_n;
807 }
809 //-----------------------------uncast---------------------------------------
810 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
811 // Strip away casting. (It is depth-limited.)
812 Node* Node::uncast() const {
813 // Should be inline:
814 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
815 if (is_ConstraintCast() || is_CheckCastPP())
816 return uncast_helper(this);
817 else
818 return (Node*) this;
819 }
821 //---------------------------uncast_helper-------------------------------------
822 Node* Node::uncast_helper(const Node* p) {
823 uint max_depth = 3;
824 for (uint i = 0; i < max_depth; i++) {
825 if (p == NULL || p->req() != 2) {
826 break;
827 } else if (p->is_ConstraintCast()) {
828 p = p->in(1);
829 } else if (p->is_CheckCastPP()) {
830 p = p->in(1);
831 } else {
832 break;
833 }
834 }
835 return (Node*) p;
836 }
838 //------------------------------add_prec---------------------------------------
839 // Add a new precedence input. Precedence inputs are unordered, with
840 // duplicates removed and NULLs packed down at the end.
841 void Node::add_prec( Node *n ) {
842 assert( is_not_dead(n), "can not use dead node");
844 // Check for NULL at end
845 if( _cnt >= _max || in(_max-1) )
846 grow( _max+1 );
848 // Find a precedence edge to move
849 uint i = _cnt;
850 while( in(i) != NULL ) i++;
851 _in[i] = n; // Stuff prec edge over NULL
852 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
853 }
855 //------------------------------rm_prec----------------------------------------
856 // Remove a precedence input. Precedence inputs are unordered, with
857 // duplicates removed and NULLs packed down at the end.
858 void Node::rm_prec( uint j ) {
860 // Find end of precedence list to pack NULLs
861 uint i;
862 for( i=j; i<_max; i++ )
863 if( !_in[i] ) // Find the NULL at end of prec edge list
864 break;
865 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
866 _in[j] = _in[--i]; // Move last element over removed guy
867 _in[i] = NULL; // NULL out last element
868 }
870 //------------------------------size_of----------------------------------------
871 uint Node::size_of() const { return sizeof(*this); }
873 //------------------------------ideal_reg--------------------------------------
874 uint Node::ideal_reg() const { return 0; }
876 //------------------------------jvms-------------------------------------------
877 JVMState* Node::jvms() const { return NULL; }
879 #ifdef ASSERT
880 //------------------------------jvms-------------------------------------------
881 bool Node::verify_jvms(const JVMState* using_jvms) const {
882 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
883 if (jvms == using_jvms) return true;
884 }
885 return false;
886 }
888 //------------------------------init_NodeProperty------------------------------
889 void Node::init_NodeProperty() {
890 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
891 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
892 }
893 #endif
895 //------------------------------format-----------------------------------------
896 // Print as assembly
897 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
898 //------------------------------emit-------------------------------------------
899 // Emit bytes starting at parameter 'ptr'.
900 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
901 //------------------------------size-------------------------------------------
902 // Size of instruction in bytes
903 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
905 //------------------------------CFG Construction-------------------------------
906 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
907 // Goto and Return.
908 const Node *Node::is_block_proj() const { return 0; }
910 // Minimum guaranteed type
911 const Type *Node::bottom_type() const { return Type::BOTTOM; }
914 //------------------------------raise_bottom_type------------------------------
915 // Get the worst-case Type output for this Node.
916 void Node::raise_bottom_type(const Type* new_type) {
917 if (is_Type()) {
918 TypeNode *n = this->as_Type();
919 if (VerifyAliases) {
920 assert(new_type->higher_equal(n->type()), "new type must refine old type");
921 }
922 n->set_type(new_type);
923 } else if (is_Load()) {
924 LoadNode *n = this->as_Load();
925 if (VerifyAliases) {
926 assert(new_type->higher_equal(n->type()), "new type must refine old type");
927 }
928 n->set_type(new_type);
929 }
930 }
932 //------------------------------Identity---------------------------------------
933 // Return a node that the given node is equivalent to.
934 Node *Node::Identity( PhaseTransform * ) {
935 return this; // Default to no identities
936 }
938 //------------------------------Value------------------------------------------
939 // Compute a new Type for a node using the Type of the inputs.
940 const Type *Node::Value( PhaseTransform * ) const {
941 return bottom_type(); // Default to worst-case Type
942 }
944 //------------------------------Ideal------------------------------------------
945 //
946 // 'Idealize' the graph rooted at this Node.
947 //
948 // In order to be efficient and flexible there are some subtle invariants
949 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
950 // these invariants, although its too slow to have on by default. If you are
951 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
952 //
953 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
954 // pointer. If ANY change is made, it must return the root of the reshaped
955 // graph - even if the root is the same Node. Example: swapping the inputs
956 // to an AddINode gives the same answer and same root, but you still have to
957 // return the 'this' pointer instead of NULL.
958 //
959 // You cannot return an OLD Node, except for the 'this' pointer. Use the
960 // Identity call to return an old Node; basically if Identity can find
961 // another Node have the Ideal call make no change and return NULL.
962 // Example: AddINode::Ideal must check for add of zero; in this case it
963 // returns NULL instead of doing any graph reshaping.
964 //
965 // You cannot modify any old Nodes except for the 'this' pointer. Due to
966 // sharing there may be other users of the old Nodes relying on their current
967 // semantics. Modifying them will break the other users.
968 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
969 // "X+3" unchanged in case it is shared.
970 //
971 // If you modify the 'this' pointer's inputs, you must use 'set_req' with
972 // def-use info. If you are making a new Node (either as the new root or
973 // some new internal piece) you must NOT use set_req with def-use info.
974 // You can make a new Node with either 'new' or 'clone'. In either case,
975 // def-use info is (correctly) not generated.
976 // Example: reshape "(X+3)+4" into "X+7":
977 // set_req(1,in(1)->in(1) /* grab X */, du /* must use DU on 'this' */);
978 // set_req(2,phase->intcon(7),du);
979 // return this;
980 // Example: reshape "X*4" into "X<<1"
981 // return new (C,3) LShiftINode( in(1), phase->intcon(1) );
982 //
983 // You must call 'phase->transform(X)' on any new Nodes X you make, except
984 // for the returned root node. Example: reshape "X*31" with "(X<<5)-1".
985 // Node *shift=phase->transform(new(C,3)LShiftINode(in(1),phase->intcon(5)));
986 // return new (C,3) AddINode(shift, phase->intcon(-1));
987 //
988 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
989 // These forms are faster than 'phase->transform(new (C,1) ConNode())' and Do
990 // The Right Thing with def-use info.
991 //
992 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
993 // graph uses the 'this' Node it must be the root. If you want a Node with
994 // the same Opcode as the 'this' pointer use 'clone'.
995 //
996 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
997 return NULL; // Default to being Ideal already
998 }
1000 // Some nodes have specific Ideal subgraph transformations only if they are
1001 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1002 // for the transformations to happen.
1003 bool Node::has_special_unique_user() const {
1004 assert(outcnt() == 1, "match only for unique out");
1005 Node* n = unique_out();
1006 int op = Opcode();
1007 if( this->is_Store() ) {
1008 // Condition for back-to-back stores folding.
1009 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1010 } else if( op == Op_AddL ) {
1011 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1012 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1013 } else if( op == Op_SubI || op == Op_SubL ) {
1014 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1015 return n->Opcode() == op && n->in(2) == this;
1016 }
1017 return false;
1018 };
1020 //--------------------------find_exact_control---------------------------------
1021 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1022 Node* Node::find_exact_control(Node* ctrl) {
1023 if (ctrl == NULL && this->is_Region())
1024 ctrl = this->as_Region()->is_copy();
1026 if (ctrl != NULL && ctrl->is_CatchProj()) {
1027 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1028 ctrl = ctrl->in(0);
1029 if (ctrl != NULL && !ctrl->is_top())
1030 ctrl = ctrl->in(0);
1031 }
1033 if (ctrl != NULL && ctrl->is_Proj())
1034 ctrl = ctrl->in(0);
1036 return ctrl;
1037 }
1039 //--------------------------dominates------------------------------------------
1040 // Helper function for MemNode::all_controls_dominate().
1041 // Check if 'this' control node dominates or equal to 'sub' control node.
1042 bool Node::dominates(Node* sub, Node_List &nlist) {
1043 assert(this->is_CFG(), "expecting control");
1044 assert(sub != NULL && sub->is_CFG(), "expecting control");
1046 // detect dead cycle without regions
1047 int iterations_without_region_limit = DominatorSearchLimit;
1049 Node* orig_sub = sub;
1050 nlist.clear();
1051 bool this_dominates = false;
1052 uint region_input = 0;
1053 while (sub != NULL) { // walk 'sub' up the chain to 'this'
1054 if (sub == this) {
1055 if (nlist.size() == 0) {
1056 // No Region nodes except loops were visited before and the EntryControl
1057 // path was taken for loops: it did not walk in a cycle.
1058 return true;
1059 } else if (!this_dominates) {
1060 // Region nodes were visited. Continue walk up to Start or Root
1061 // to make sure that it did not walk in a cycle.
1062 this_dominates = true; // first time meet
1063 iterations_without_region_limit = DominatorSearchLimit; // Reset
1064 } else {
1065 return false; // already met before: walk in a cycle
1066 }
1067 }
1068 if (sub->is_Start() || sub->is_Root())
1069 return this_dominates;
1071 Node* up = sub->find_exact_control(sub->in(0));
1072 if (up == NULL || up->is_top())
1073 return false; // Conservative answer for dead code
1075 if (sub == up && sub->is_Loop()) {
1076 up = sub->in(1); // in(LoopNode::EntryControl);
1077 } else if (sub == up && sub->is_Region() && sub->req() == 3) {
1078 iterations_without_region_limit = DominatorSearchLimit; // Reset
1079 uint i = 1;
1080 uint size = nlist.size();
1081 if (size == 0) {
1082 // No Region nodes (except Loops) were visited before.
1083 // Take first valid path on the way up to 'this'.
1084 } else if (nlist.at(size - 1) == sub) {
1085 // This Region node was just visited. Take other path.
1086 i = region_input + 1;
1087 nlist.pop();
1088 } else {
1089 // Was this Region node visited before?
1090 for (uint j = 0; j < size; j++) {
1091 if (nlist.at(j) == sub) {
1092 return false; // The Region node was visited before. Give up.
1093 }
1094 }
1095 // The Region node was not visited before.
1096 // Take first valid path on the way up to 'this'.
1097 }
1098 for (; i < sub->req(); i++) {
1099 Node* in = sub->in(i);
1100 if (in != NULL && !in->is_top() && in != sub) {
1101 break;
1102 }
1103 }
1104 if (i < sub->req()) {
1105 nlist.push(sub);
1106 up = sub->in(i);
1107 region_input = i;
1108 }
1109 }
1110 if (sub == up)
1111 return false; // some kind of tight cycle
1113 if (--iterations_without_region_limit < 0)
1114 return false; // dead cycle
1116 sub = up;
1117 }
1118 return false;
1119 }
1121 //------------------------------remove_dead_region-----------------------------
1122 // This control node is dead. Follow the subgraph below it making everything
1123 // using it dead as well. This will happen normally via the usual IterGVN
1124 // worklist but this call is more efficient. Do not update use-def info
1125 // inside the dead region, just at the borders.
1126 static bool kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1127 // Con's are a popular node to re-hit in the hash table again.
1128 if( dead->is_Con() ) return false;
1130 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1131 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1132 Node_List nstack(Thread::current()->resource_area());
1134 Node *top = igvn->C->top();
1135 bool progress = false;
1136 nstack.push(dead);
1138 while (nstack.size() > 0) {
1139 dead = nstack.pop();
1140 if (dead->outcnt() > 0) {
1141 // Keep dead node on stack until all uses are processed.
1142 nstack.push(dead);
1143 // For all Users of the Dead... ;-)
1144 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1145 Node* use = dead->last_out(k);
1146 igvn->hash_delete(use); // Yank from hash table prior to mod
1147 if (use->in(0) == dead) { // Found another dead node
1148 assert (!use->is_Con(), "Control for Con node should be Root node.")
1149 use->set_req(0, top); // Cut dead edge to prevent processing
1150 nstack.push(use); // the dead node again.
1151 } else { // Else found a not-dead user
1152 for (uint j = 1; j < use->req(); j++) {
1153 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1154 use->set_req(j, top);
1155 }
1156 }
1157 igvn->_worklist.push(use);
1158 }
1159 // Refresh the iterator, since any number of kills might have happened.
1160 k = dead->last_outs(kmin);
1161 }
1162 } else { // (dead->outcnt() == 0)
1163 // Done with outputs.
1164 igvn->hash_delete(dead);
1165 igvn->_worklist.remove(dead);
1166 igvn->set_type(dead, Type::TOP);
1167 if (dead->is_macro()) {
1168 igvn->C->remove_macro_node(dead);
1169 }
1170 // Kill all inputs to the dead guy
1171 for (uint i=0; i < dead->req(); i++) {
1172 Node *n = dead->in(i); // Get input to dead guy
1173 if (n != NULL && !n->is_top()) { // Input is valid?
1174 progress = true;
1175 dead->set_req(i, top); // Smash input away
1176 if (n->outcnt() == 0) { // Input also goes dead?
1177 if (!n->is_Con())
1178 nstack.push(n); // Clear it out as well
1179 } else if (n->outcnt() == 1 &&
1180 n->has_special_unique_user()) {
1181 igvn->add_users_to_worklist( n );
1182 } else if (n->outcnt() <= 2 && n->is_Store()) {
1183 // Push store's uses on worklist to enable folding optimization for
1184 // store/store and store/load to the same address.
1185 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1186 // and remove_globally_dead_node().
1187 igvn->add_users_to_worklist( n );
1188 }
1189 }
1190 }
1191 } // (dead->outcnt() == 0)
1192 } // while (nstack.size() > 0) for outputs
1193 return progress;
1194 }
1196 //------------------------------remove_dead_region-----------------------------
1197 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1198 Node *n = in(0);
1199 if( !n ) return false;
1200 // Lost control into this guy? I.e., it became unreachable?
1201 // Aggressively kill all unreachable code.
1202 if (can_reshape && n->is_top()) {
1203 return kill_dead_code(this, phase->is_IterGVN());
1204 }
1206 if( n->is_Region() && n->as_Region()->is_copy() ) {
1207 Node *m = n->nonnull_req();
1208 set_req(0, m);
1209 return true;
1210 }
1211 return false;
1212 }
1214 //------------------------------Ideal_DU_postCCP-------------------------------
1215 // Idealize graph, using DU info. Must clone result into new-space
1216 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1217 return NULL; // Default to no change
1218 }
1220 //------------------------------hash-------------------------------------------
1221 // Hash function over Nodes.
1222 uint Node::hash() const {
1223 uint sum = 0;
1224 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1225 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1226 return (sum>>2) + _cnt + Opcode();
1227 }
1229 //------------------------------cmp--------------------------------------------
1230 // Compare special parts of simple Nodes
1231 uint Node::cmp( const Node &n ) const {
1232 return 1; // Must be same
1233 }
1235 //------------------------------rematerialize-----------------------------------
1236 // Should we clone rather than spill this instruction?
1237 bool Node::rematerialize() const {
1238 if ( is_Mach() )
1239 return this->as_Mach()->rematerialize();
1240 else
1241 return (_flags & Flag_rematerialize) != 0;
1242 }
1244 //------------------------------needs_anti_dependence_check---------------------
1245 // Nodes which use memory without consuming it, hence need antidependences.
1246 bool Node::needs_anti_dependence_check() const {
1247 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1248 return false;
1249 else
1250 return in(1)->bottom_type()->has_memory();
1251 }
1254 // Get an integer constant from a ConNode (or CastIINode).
1255 // Return a default value if there is no apparent constant here.
1256 const TypeInt* Node::find_int_type() const {
1257 if (this->is_Type()) {
1258 return this->as_Type()->type()->isa_int();
1259 } else if (this->is_Con()) {
1260 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1261 return this->bottom_type()->isa_int();
1262 }
1263 return NULL;
1264 }
1266 // Get a pointer constant from a ConstNode.
1267 // Returns the constant if it is a pointer ConstNode
1268 intptr_t Node::get_ptr() const {
1269 assert( Opcode() == Op_ConP, "" );
1270 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1271 }
1273 // Get a narrow oop constant from a ConNNode.
1274 intptr_t Node::get_narrowcon() const {
1275 assert( Opcode() == Op_ConN, "" );
1276 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1277 }
1279 // Get a long constant from a ConNode.
1280 // Return a default value if there is no apparent constant here.
1281 const TypeLong* Node::find_long_type() const {
1282 if (this->is_Type()) {
1283 return this->as_Type()->type()->isa_long();
1284 } else if (this->is_Con()) {
1285 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1286 return this->bottom_type()->isa_long();
1287 }
1288 return NULL;
1289 }
1291 // Get a double constant from a ConstNode.
1292 // Returns the constant if it is a double ConstNode
1293 jdouble Node::getd() const {
1294 assert( Opcode() == Op_ConD, "" );
1295 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1296 }
1298 // Get a float constant from a ConstNode.
1299 // Returns the constant if it is a float ConstNode
1300 jfloat Node::getf() const {
1301 assert( Opcode() == Op_ConF, "" );
1302 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1303 }
1305 #ifndef PRODUCT
1307 //----------------------------NotANode----------------------------------------
1308 // Used in debugging code to avoid walking across dead or uninitialized edges.
1309 static inline bool NotANode(const Node* n) {
1310 if (n == NULL) return true;
1311 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1312 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1313 return false;
1314 }
1317 //------------------------------find------------------------------------------
1318 // Find a neighbor of this Node with the given _idx
1319 // If idx is negative, find its absolute value, following both _in and _out.
1320 static void find_recur( Node* &result, Node *n, int idx, bool only_ctrl,
1321 VectorSet &old_space, VectorSet &new_space ) {
1322 int node_idx = (idx >= 0) ? idx : -idx;
1323 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1324 // Contained in new_space or old_space?
1325 VectorSet *v = Compile::current()->node_arena()->contains(n) ? &new_space : &old_space;
1326 if( v->test(n->_idx) ) return;
1327 if( (int)n->_idx == node_idx
1328 debug_only(|| n->debug_idx() == node_idx) ) {
1329 if (result != NULL)
1330 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1331 (uintptr_t)result, (uintptr_t)n, node_idx);
1332 result = n;
1333 }
1334 v->set(n->_idx);
1335 for( uint i=0; i<n->len(); i++ ) {
1336 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1337 find_recur( result, n->in(i), idx, only_ctrl, old_space, new_space );
1338 }
1339 // Search along forward edges also:
1340 if (idx < 0 && !only_ctrl) {
1341 for( uint j=0; j<n->outcnt(); j++ ) {
1342 find_recur( result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1343 }
1344 }
1345 #ifdef ASSERT
1346 // Search along debug_orig edges last:
1347 for (Node* orig = n->debug_orig(); orig != NULL; orig = orig->debug_orig()) {
1348 if (NotANode(orig)) break;
1349 find_recur( result, orig, idx, only_ctrl, old_space, new_space );
1350 }
1351 #endif //ASSERT
1352 }
1354 // call this from debugger:
1355 Node* find_node(Node* n, int idx) {
1356 return n->find(idx);
1357 }
1359 //------------------------------find-------------------------------------------
1360 Node* Node::find(int idx) const {
1361 ResourceArea *area = Thread::current()->resource_area();
1362 VectorSet old_space(area), new_space(area);
1363 Node* result = NULL;
1364 find_recur( result, (Node*) this, idx, false, old_space, new_space );
1365 return result;
1366 }
1368 //------------------------------find_ctrl--------------------------------------
1369 // Find an ancestor to this node in the control history with given _idx
1370 Node* Node::find_ctrl(int idx) const {
1371 ResourceArea *area = Thread::current()->resource_area();
1372 VectorSet old_space(area), new_space(area);
1373 Node* result = NULL;
1374 find_recur( result, (Node*) this, idx, true, old_space, new_space );
1375 return result;
1376 }
1377 #endif
1381 #ifndef PRODUCT
1382 int Node::_in_dump_cnt = 0;
1384 // -----------------------------Name-------------------------------------------
1385 extern const char *NodeClassNames[];
1386 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1388 static bool is_disconnected(const Node* n) {
1389 for (uint i = 0; i < n->req(); i++) {
1390 if (n->in(i) != NULL) return false;
1391 }
1392 return true;
1393 }
1395 #ifdef ASSERT
1396 static void dump_orig(Node* orig) {
1397 Compile* C = Compile::current();
1398 if (NotANode(orig)) orig = NULL;
1399 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1400 if (orig == NULL) return;
1401 tty->print(" !orig=");
1402 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1403 if (NotANode(fast)) fast = NULL;
1404 while (orig != NULL) {
1405 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1406 if (discon) tty->print("[");
1407 if (!Compile::current()->node_arena()->contains(orig))
1408 tty->print("o");
1409 tty->print("%d", orig->_idx);
1410 if (discon) tty->print("]");
1411 orig = orig->debug_orig();
1412 if (NotANode(orig)) orig = NULL;
1413 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1414 if (orig != NULL) tty->print(",");
1415 if (fast != NULL) {
1416 // Step fast twice for each single step of orig:
1417 fast = fast->debug_orig();
1418 if (NotANode(fast)) fast = NULL;
1419 if (fast != NULL && fast != orig) {
1420 fast = fast->debug_orig();
1421 if (NotANode(fast)) fast = NULL;
1422 }
1423 if (fast == orig) {
1424 tty->print("...");
1425 break;
1426 }
1427 }
1428 }
1429 }
1431 void Node::set_debug_orig(Node* orig) {
1432 _debug_orig = orig;
1433 if (BreakAtNode == 0) return;
1434 if (NotANode(orig)) orig = NULL;
1435 int trip = 10;
1436 while (orig != NULL) {
1437 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1438 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1439 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1440 BREAKPOINT;
1441 }
1442 orig = orig->debug_orig();
1443 if (NotANode(orig)) orig = NULL;
1444 if (trip-- <= 0) break;
1445 }
1446 }
1447 #endif //ASSERT
1449 //------------------------------dump------------------------------------------
1450 // Dump a Node
1451 void Node::dump() const {
1452 Compile* C = Compile::current();
1453 bool is_new = C->node_arena()->contains(this);
1454 _in_dump_cnt++;
1455 tty->print("%c%d\t%s\t=== ",
1456 is_new ? ' ' : 'o', _idx, Name());
1458 // Dump the required and precedence inputs
1459 dump_req();
1460 dump_prec();
1461 // Dump the outputs
1462 dump_out();
1464 if (is_disconnected(this)) {
1465 #ifdef ASSERT
1466 tty->print(" [%d]",debug_idx());
1467 dump_orig(debug_orig());
1468 #endif
1469 tty->cr();
1470 _in_dump_cnt--;
1471 return; // don't process dead nodes
1472 }
1474 // Dump node-specific info
1475 dump_spec(tty);
1476 #ifdef ASSERT
1477 // Dump the non-reset _debug_idx
1478 if( Verbose && WizardMode ) {
1479 tty->print(" [%d]",debug_idx());
1480 }
1481 #endif
1483 const Type *t = bottom_type();
1485 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1486 const TypeInstPtr *toop = t->isa_instptr();
1487 const TypeKlassPtr *tkls = t->isa_klassptr();
1488 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1489 if( klass && klass->is_loaded() && klass->is_interface() ) {
1490 tty->print(" Interface:");
1491 } else if( toop ) {
1492 tty->print(" Oop:");
1493 } else if( tkls ) {
1494 tty->print(" Klass:");
1495 }
1496 t->dump();
1497 } else if( t == Type::MEMORY ) {
1498 tty->print(" Memory:");
1499 MemNode::dump_adr_type(this, adr_type(), tty);
1500 } else if( Verbose || WizardMode ) {
1501 tty->print(" Type:");
1502 if( t ) {
1503 t->dump();
1504 } else {
1505 tty->print("no type");
1506 }
1507 }
1508 if (is_new) {
1509 debug_only(dump_orig(debug_orig()));
1510 Node_Notes* nn = C->node_notes_at(_idx);
1511 if (nn != NULL && !nn->is_clear()) {
1512 if (nn->jvms() != NULL) {
1513 tty->print(" !jvms:");
1514 nn->jvms()->dump_spec(tty);
1515 }
1516 }
1517 }
1518 tty->cr();
1519 _in_dump_cnt--;
1520 }
1522 //------------------------------dump_req--------------------------------------
1523 void Node::dump_req() const {
1524 // Dump the required input edges
1525 for (uint i = 0; i < req(); i++) { // For all required inputs
1526 Node* d = in(i);
1527 if (d == NULL) {
1528 tty->print("_ ");
1529 } else if (NotANode(d)) {
1530 tty->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1531 } else {
1532 tty->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1533 }
1534 }
1535 }
1538 //------------------------------dump_prec-------------------------------------
1539 void Node::dump_prec() const {
1540 // Dump the precedence edges
1541 int any_prec = 0;
1542 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1543 Node* p = in(i);
1544 if (p != NULL) {
1545 if( !any_prec++ ) tty->print(" |");
1546 if (NotANode(p)) { tty->print("NotANode "); continue; }
1547 tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1548 }
1549 }
1550 }
1552 //------------------------------dump_out--------------------------------------
1553 void Node::dump_out() const {
1554 // Delimit the output edges
1555 tty->print(" [[");
1556 // Dump the output edges
1557 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1558 Node* u = _out[i];
1559 if (u == NULL) {
1560 tty->print("_ ");
1561 } else if (NotANode(u)) {
1562 tty->print("NotANode ");
1563 } else {
1564 tty->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1565 }
1566 }
1567 tty->print("]] ");
1568 }
1570 //------------------------------dump_nodes-------------------------------------
1571 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1572 Node* s = (Node*)start; // remove const
1573 if (NotANode(s)) return;
1575 uint depth = (uint)ABS(d);
1576 int direction = d;
1577 Compile* C = Compile::current();
1578 GrowableArray <Node *> nstack(C->unique());
1580 nstack.append(s);
1581 int begin = 0;
1582 int end = 0;
1583 for(uint i = 0; i < depth; i++) {
1584 end = nstack.length();
1585 for(int j = begin; j < end; j++) {
1586 Node* tp = nstack.at(j);
1587 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1588 for(uint k = 0; k < limit; k++) {
1589 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1591 if (NotANode(n)) continue;
1592 // do not recurse through top or the root (would reach unrelated stuff)
1593 if (n->is_Root() || n->is_top()) continue;
1594 if (only_ctrl && !n->is_CFG()) continue;
1596 bool on_stack = nstack.contains(n);
1597 if (!on_stack) {
1598 nstack.append(n);
1599 }
1600 }
1601 }
1602 begin = end;
1603 }
1604 end = nstack.length();
1605 if (direction > 0) {
1606 for(int j = end-1; j >= 0; j--) {
1607 nstack.at(j)->dump();
1608 }
1609 } else {
1610 for(int j = 0; j < end; j++) {
1611 nstack.at(j)->dump();
1612 }
1613 }
1614 }
1616 //------------------------------dump-------------------------------------------
1617 void Node::dump(int d) const {
1618 dump_nodes(this, d, false);
1619 }
1621 //------------------------------dump_ctrl--------------------------------------
1622 // Dump a Node's control history to depth
1623 void Node::dump_ctrl(int d) const {
1624 dump_nodes(this, d, true);
1625 }
1627 // VERIFICATION CODE
1628 // For each input edge to a node (ie - for each Use-Def edge), verify that
1629 // there is a corresponding Def-Use edge.
1630 //------------------------------verify_edges-----------------------------------
1631 void Node::verify_edges(Unique_Node_List &visited) {
1632 uint i, j, idx;
1633 int cnt;
1634 Node *n;
1636 // Recursive termination test
1637 if (visited.member(this)) return;
1638 visited.push(this);
1640 // Walk over all input edges, checking for correspondance
1641 for( i = 0; i < len(); i++ ) {
1642 n = in(i);
1643 if (n != NULL && !n->is_top()) {
1644 // Count instances of (Node *)this
1645 cnt = 0;
1646 for (idx = 0; idx < n->_outcnt; idx++ ) {
1647 if (n->_out[idx] == (Node *)this) cnt++;
1648 }
1649 assert( cnt > 0,"Failed to find Def-Use edge." );
1650 // Check for duplicate edges
1651 // walk the input array downcounting the input edges to n
1652 for( j = 0; j < len(); j++ ) {
1653 if( in(j) == n ) cnt--;
1654 }
1655 assert( cnt == 0,"Mismatched edge count.");
1656 } else if (n == NULL) {
1657 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1658 } else {
1659 assert(n->is_top(), "sanity");
1660 // Nothing to check.
1661 }
1662 }
1663 // Recursive walk over all input edges
1664 for( i = 0; i < len(); i++ ) {
1665 n = in(i);
1666 if( n != NULL )
1667 in(i)->verify_edges(visited);
1668 }
1669 }
1671 //------------------------------verify_recur-----------------------------------
1672 static const Node *unique_top = NULL;
1674 void Node::verify_recur(const Node *n, int verify_depth,
1675 VectorSet &old_space, VectorSet &new_space) {
1676 if ( verify_depth == 0 ) return;
1677 if (verify_depth > 0) --verify_depth;
1679 Compile* C = Compile::current();
1681 // Contained in new_space or old_space?
1682 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1683 // Check for visited in the proper space. Numberings are not unique
1684 // across spaces so we need a seperate VectorSet for each space.
1685 if( v->test_set(n->_idx) ) return;
1687 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1688 if (C->cached_top_node() == NULL)
1689 C->set_cached_top_node((Node*)n);
1690 assert(C->cached_top_node() == n, "TOP node must be unique");
1691 }
1693 for( uint i = 0; i < n->len(); i++ ) {
1694 Node *x = n->in(i);
1695 if (!x || x->is_top()) continue;
1697 // Verify my input has a def-use edge to me
1698 if (true /*VerifyDefUse*/) {
1699 // Count use-def edges from n to x
1700 int cnt = 0;
1701 for( uint j = 0; j < n->len(); j++ )
1702 if( n->in(j) == x )
1703 cnt++;
1704 // Count def-use edges from x to n
1705 uint max = x->_outcnt;
1706 for( uint k = 0; k < max; k++ )
1707 if (x->_out[k] == n)
1708 cnt--;
1709 assert( cnt == 0, "mismatched def-use edge counts" );
1710 }
1712 verify_recur(x, verify_depth, old_space, new_space);
1713 }
1715 }
1717 //------------------------------verify-----------------------------------------
1718 // Check Def-Use info for my subgraph
1719 void Node::verify() const {
1720 Compile* C = Compile::current();
1721 Node* old_top = C->cached_top_node();
1722 ResourceMark rm;
1723 ResourceArea *area = Thread::current()->resource_area();
1724 VectorSet old_space(area), new_space(area);
1725 verify_recur(this, -1, old_space, new_space);
1726 C->set_cached_top_node(old_top);
1727 }
1728 #endif
1731 //------------------------------walk-------------------------------------------
1732 // Graph walk, with both pre-order and post-order functions
1733 void Node::walk(NFunc pre, NFunc post, void *env) {
1734 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1735 walk_(pre, post, env, visited);
1736 }
1738 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1739 if( visited.test_set(_idx) ) return;
1740 pre(*this,env); // Call the pre-order walk function
1741 for( uint i=0; i<_max; i++ )
1742 if( in(i) ) // Input exists and is not walked?
1743 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1744 post(*this,env); // Call the post-order walk function
1745 }
1747 void Node::nop(Node &, void*) {}
1749 //------------------------------Registers--------------------------------------
1750 // Do we Match on this edge index or not? Generally false for Control
1751 // and true for everything else. Weird for calls & returns.
1752 uint Node::match_edge(uint idx) const {
1753 return idx; // True for other than index 0 (control)
1754 }
1756 // Register classes are defined for specific machines
1757 const RegMask &Node::out_RegMask() const {
1758 ShouldNotCallThis();
1759 return *(new RegMask());
1760 }
1762 const RegMask &Node::in_RegMask(uint) const {
1763 ShouldNotCallThis();
1764 return *(new RegMask());
1765 }
1767 //=============================================================================
1768 //-----------------------------------------------------------------------------
1769 void Node_Array::reset( Arena *new_arena ) {
1770 _a->Afree(_nodes,_max*sizeof(Node*));
1771 _max = 0;
1772 _nodes = NULL;
1773 _a = new_arena;
1774 }
1776 //------------------------------clear------------------------------------------
1777 // Clear all entries in _nodes to NULL but keep storage
1778 void Node_Array::clear() {
1779 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1780 }
1782 //-----------------------------------------------------------------------------
1783 void Node_Array::grow( uint i ) {
1784 if( !_max ) {
1785 _max = 1;
1786 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1787 _nodes[0] = NULL;
1788 }
1789 uint old = _max;
1790 while( i >= _max ) _max <<= 1; // Double to fit
1791 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1792 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1793 }
1795 //-----------------------------------------------------------------------------
1796 void Node_Array::insert( uint i, Node *n ) {
1797 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1798 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1799 _nodes[i] = n;
1800 }
1802 //-----------------------------------------------------------------------------
1803 void Node_Array::remove( uint i ) {
1804 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1805 _nodes[_max-1] = NULL;
1806 }
1808 //-----------------------------------------------------------------------------
1809 void Node_Array::sort( C_sort_func_t func) {
1810 qsort( _nodes, _max, sizeof( Node* ), func );
1811 }
1813 //-----------------------------------------------------------------------------
1814 void Node_Array::dump() const {
1815 #ifndef PRODUCT
1816 for( uint i = 0; i < _max; i++ ) {
1817 Node *nn = _nodes[i];
1818 if( nn != NULL ) {
1819 tty->print("%5d--> ",i); nn->dump();
1820 }
1821 }
1822 #endif
1823 }
1825 //--------------------------is_iteratively_computed------------------------------
1826 // Operation appears to be iteratively computed (such as an induction variable)
1827 // It is possible for this operation to return false for a loop-varying
1828 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1829 bool Node::is_iteratively_computed() {
1830 if (ideal_reg()) { // does operation have a result register?
1831 for (uint i = 1; i < req(); i++) {
1832 Node* n = in(i);
1833 if (n != NULL && n->is_Phi()) {
1834 for (uint j = 1; j < n->req(); j++) {
1835 if (n->in(j) == this) {
1836 return true;
1837 }
1838 }
1839 }
1840 }
1841 }
1842 return false;
1843 }
1845 //--------------------------find_similar------------------------------
1846 // Return a node with opcode "opc" and same inputs as "this" if one can
1847 // be found; Otherwise return NULL;
1848 Node* Node::find_similar(int opc) {
1849 if (req() >= 2) {
1850 Node* def = in(1);
1851 if (def && def->outcnt() >= 2) {
1852 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
1853 Node* use = def->fast_out(i);
1854 if (use->Opcode() == opc &&
1855 use->req() == req()) {
1856 uint j;
1857 for (j = 0; j < use->req(); j++) {
1858 if (use->in(j) != in(j)) {
1859 break;
1860 }
1861 }
1862 if (j == use->req()) {
1863 return use;
1864 }
1865 }
1866 }
1867 }
1868 }
1869 return NULL;
1870 }
1873 //--------------------------unique_ctrl_out------------------------------
1874 // Return the unique control out if only one. Null if none or more than one.
1875 Node* Node::unique_ctrl_out() {
1876 Node* found = NULL;
1877 for (uint i = 0; i < outcnt(); i++) {
1878 Node* use = raw_out(i);
1879 if (use->is_CFG() && use != this) {
1880 if (found != NULL) return NULL;
1881 found = use;
1882 }
1883 }
1884 return found;
1885 }
1887 //=============================================================================
1888 //------------------------------yank-------------------------------------------
1889 // Find and remove
1890 void Node_List::yank( Node *n ) {
1891 uint i;
1892 for( i = 0; i < _cnt; i++ )
1893 if( _nodes[i] == n )
1894 break;
1896 if( i < _cnt )
1897 _nodes[i] = _nodes[--_cnt];
1898 }
1900 //------------------------------dump-------------------------------------------
1901 void Node_List::dump() const {
1902 #ifndef PRODUCT
1903 for( uint i = 0; i < _cnt; i++ )
1904 if( _nodes[i] ) {
1905 tty->print("%5d--> ",i);
1906 _nodes[i]->dump();
1907 }
1908 #endif
1909 }
1911 //=============================================================================
1912 //------------------------------remove-----------------------------------------
1913 void Unique_Node_List::remove( Node *n ) {
1914 if( _in_worklist[n->_idx] ) {
1915 for( uint i = 0; i < size(); i++ )
1916 if( _nodes[i] == n ) {
1917 map(i,Node_List::pop());
1918 _in_worklist >>= n->_idx;
1919 return;
1920 }
1921 ShouldNotReachHere();
1922 }
1923 }
1925 //-----------------------remove_useless_nodes----------------------------------
1926 // Remove useless nodes from worklist
1927 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
1929 for( uint i = 0; i < size(); ++i ) {
1930 Node *n = at(i);
1931 assert( n != NULL, "Did not expect null entries in worklist");
1932 if( ! useful.test(n->_idx) ) {
1933 _in_worklist >>= n->_idx;
1934 map(i,Node_List::pop());
1935 // Node *replacement = Node_List::pop();
1936 // if( i != size() ) { // Check if removing last entry
1937 // _nodes[i] = replacement;
1938 // }
1939 --i; // Visit popped node
1940 // If it was last entry, loop terminates since size() was also reduced
1941 }
1942 }
1943 }
1945 //=============================================================================
1946 void Node_Stack::grow() {
1947 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
1948 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
1949 size_t max = old_max << 1; // max * 2
1950 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
1951 _inode_max = _inodes + max;
1952 _inode_top = _inodes + old_top; // restore _top
1953 }
1955 //=============================================================================
1956 uint TypeNode::size_of() const { return sizeof(*this); }
1957 #ifndef PRODUCT
1958 void TypeNode::dump_spec(outputStream *st) const {
1959 if( !Verbose && !WizardMode ) {
1960 // standard dump does this in Verbose and WizardMode
1961 st->print(" #"); _type->dump_on(st);
1962 }
1963 }
1964 #endif
1965 uint TypeNode::hash() const {
1966 return Node::hash() + _type->hash();
1967 }
1968 uint TypeNode::cmp( const Node &n ) const
1969 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
1970 const Type *TypeNode::bottom_type() const { return _type; }
1971 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
1973 //------------------------------ideal_reg--------------------------------------
1974 uint TypeNode::ideal_reg() const {
1975 return Matcher::base2reg[_type->base()];
1976 }