Mon, 23 Jun 2014 13:33:23 +0200
8046289: compiler/6340864/TestLongVect.java timeout with
Reviewed-by: iveresov, vlivanov
1 /*
2 * Copyright (c) 1997, 2014, 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 */
25 #include "precompiled.hpp"
26 #include "libadt/vectset.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "opto/cfgnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/loopnode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/node.hpp"
34 #include "opto/opcodes.hpp"
35 #include "opto/regmask.hpp"
36 #include "opto/type.hpp"
37 #include "utilities/copy.hpp"
39 class RegMask;
40 // #include "phase.hpp"
41 class PhaseTransform;
42 class PhaseGVN;
44 // Arena we are currently building Nodes in
45 const uint Node::NotAMachineReg = 0xffff0000;
47 #ifndef PRODUCT
48 extern int nodes_created;
49 #endif
51 #ifdef ASSERT
53 //-------------------------- construct_node------------------------------------
54 // Set a breakpoint here to identify where a particular node index is built.
55 void Node::verify_construction() {
56 _debug_orig = NULL;
57 int old_debug_idx = Compile::debug_idx();
58 int new_debug_idx = old_debug_idx+1;
59 if (new_debug_idx > 0) {
60 // Arrange that the lowest five decimal digits of _debug_idx
61 // will repeat those of _idx. In case this is somehow pathological,
62 // we continue to assign negative numbers (!) consecutively.
63 const int mod = 100000;
64 int bump = (int)(_idx - new_debug_idx) % mod;
65 if (bump < 0) bump += mod;
66 assert(bump >= 0 && bump < mod, "");
67 new_debug_idx += bump;
68 }
69 Compile::set_debug_idx(new_debug_idx);
70 set_debug_idx( new_debug_idx );
71 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
72 assert(Compile::current()->live_nodes() < (uint)MaxNodeLimit, "Live Node limit exceeded limit");
73 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
74 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
75 BREAKPOINT;
76 }
77 #if OPTO_DU_ITERATOR_ASSERT
78 _last_del = NULL;
79 _del_tick = 0;
80 #endif
81 _hash_lock = 0;
82 }
85 // #ifdef ASSERT ...
87 #if OPTO_DU_ITERATOR_ASSERT
88 void DUIterator_Common::sample(const Node* node) {
89 _vdui = VerifyDUIterators;
90 _node = node;
91 _outcnt = node->_outcnt;
92 _del_tick = node->_del_tick;
93 _last = NULL;
94 }
96 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
97 assert(_node == node, "consistent iterator source");
98 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
99 }
101 void DUIterator_Common::verify_resync() {
102 // Ensure that the loop body has just deleted the last guy produced.
103 const Node* node = _node;
104 // Ensure that at least one copy of the last-seen edge was deleted.
105 // Note: It is OK to delete multiple copies of the last-seen edge.
106 // Unfortunately, we have no way to verify that all the deletions delete
107 // that same edge. On this point we must use the Honor System.
108 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
109 assert(node->_last_del == _last, "must have deleted the edge just produced");
110 // We liked this deletion, so accept the resulting outcnt and tick.
111 _outcnt = node->_outcnt;
112 _del_tick = node->_del_tick;
113 }
115 void DUIterator_Common::reset(const DUIterator_Common& that) {
116 if (this == &that) return; // ignore assignment to self
117 if (!_vdui) {
118 // We need to initialize everything, overwriting garbage values.
119 _last = that._last;
120 _vdui = that._vdui;
121 }
122 // Note: It is legal (though odd) for an iterator over some node x
123 // to be reassigned to iterate over another node y. Some doubly-nested
124 // progress loops depend on being able to do this.
125 const Node* node = that._node;
126 // Re-initialize everything, except _last.
127 _node = node;
128 _outcnt = node->_outcnt;
129 _del_tick = node->_del_tick;
130 }
132 void DUIterator::sample(const Node* node) {
133 DUIterator_Common::sample(node); // Initialize the assertion data.
134 _refresh_tick = 0; // No refreshes have happened, as yet.
135 }
137 void DUIterator::verify(const Node* node, bool at_end_ok) {
138 DUIterator_Common::verify(node, at_end_ok);
139 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
140 }
142 void DUIterator::verify_increment() {
143 if (_refresh_tick & 1) {
144 // We have refreshed the index during this loop.
145 // Fix up _idx to meet asserts.
146 if (_idx > _outcnt) _idx = _outcnt;
147 }
148 verify(_node, true);
149 }
151 void DUIterator::verify_resync() {
152 // Note: We do not assert on _outcnt, because insertions are OK here.
153 DUIterator_Common::verify_resync();
154 // Make sure we are still in sync, possibly with no more out-edges:
155 verify(_node, true);
156 }
158 void DUIterator::reset(const DUIterator& that) {
159 if (this == &that) return; // self assignment is always a no-op
160 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
161 assert(that._idx == 0, "assign only the result of Node::outs()");
162 assert(_idx == that._idx, "already assigned _idx");
163 if (!_vdui) {
164 // We need to initialize everything, overwriting garbage values.
165 sample(that._node);
166 } else {
167 DUIterator_Common::reset(that);
168 if (_refresh_tick & 1) {
169 _refresh_tick++; // Clear the "was refreshed" flag.
170 }
171 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
172 }
173 }
175 void DUIterator::refresh() {
176 DUIterator_Common::sample(_node); // Re-fetch assertion data.
177 _refresh_tick |= 1; // Set the "was refreshed" flag.
178 }
180 void DUIterator::verify_finish() {
181 // If the loop has killed the node, do not require it to re-run.
182 if (_node->_outcnt == 0) _refresh_tick &= ~1;
183 // If this assert triggers, it means that a loop used refresh_out_pos
184 // to re-synch an iteration index, but the loop did not correctly
185 // re-run itself, using a "while (progress)" construct.
186 // This iterator enforces the rule that you must keep trying the loop
187 // until it "runs clean" without any need for refreshing.
188 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
189 }
192 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
193 DUIterator_Common::verify(node, at_end_ok);
194 Node** out = node->_out;
195 uint cnt = node->_outcnt;
196 assert(cnt == _outcnt, "no insertions allowed");
197 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
198 // This last check is carefully designed to work for NO_OUT_ARRAY.
199 }
201 void DUIterator_Fast::verify_limit() {
202 const Node* node = _node;
203 verify(node, true);
204 assert(_outp == node->_out + node->_outcnt, "limit still correct");
205 }
207 void DUIterator_Fast::verify_resync() {
208 const Node* node = _node;
209 if (_outp == node->_out + _outcnt) {
210 // Note that the limit imax, not the pointer i, gets updated with the
211 // exact count of deletions. (For the pointer it's always "--i".)
212 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
213 // This is a limit pointer, with a name like "imax".
214 // Fudge the _last field so that the common assert will be happy.
215 _last = (Node*) node->_last_del;
216 DUIterator_Common::verify_resync();
217 } else {
218 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
219 // A normal internal pointer.
220 DUIterator_Common::verify_resync();
221 // Make sure we are still in sync, possibly with no more out-edges:
222 verify(node, true);
223 }
224 }
226 void DUIterator_Fast::verify_relimit(uint n) {
227 const Node* node = _node;
228 assert((int)n > 0, "use imax -= n only with a positive count");
229 // This must be a limit pointer, with a name like "imax".
230 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
231 // The reported number of deletions must match what the node saw.
232 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
233 // Fudge the _last field so that the common assert will be happy.
234 _last = (Node*) node->_last_del;
235 DUIterator_Common::verify_resync();
236 }
238 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
239 assert(_outp == that._outp, "already assigned _outp");
240 DUIterator_Common::reset(that);
241 }
243 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
244 // at_end_ok means the _outp is allowed to underflow by 1
245 _outp += at_end_ok;
246 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
247 _outp -= at_end_ok;
248 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
249 }
251 void DUIterator_Last::verify_limit() {
252 // Do not require the limit address to be resynched.
253 //verify(node, true);
254 assert(_outp == _node->_out, "limit still correct");
255 }
257 void DUIterator_Last::verify_step(uint num_edges) {
258 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
259 _outcnt -= num_edges;
260 _del_tick += num_edges;
261 // Make sure we are still in sync, possibly with no more out-edges:
262 const Node* node = _node;
263 verify(node, true);
264 assert(node->_last_del == _last, "must have deleted the edge just produced");
265 }
267 #endif //OPTO_DU_ITERATOR_ASSERT
270 #endif //ASSERT
273 // This constant used to initialize _out may be any non-null value.
274 // The value NULL is reserved for the top node only.
275 #define NO_OUT_ARRAY ((Node**)-1)
277 // This funny expression handshakes with Node::operator new
278 // to pull Compile::current out of the new node's _out field,
279 // and then calls a subroutine which manages most field
280 // initializations. The only one which is tricky is the
281 // _idx field, which is const, and so must be initialized
282 // by a return value, not an assignment.
283 //
284 // (Aren't you thankful that Java finals don't require so many tricks?)
285 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
286 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
287 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
288 #endif
290 // Out-of-line code from node constructors.
291 // Executed only when extra debug info. is being passed around.
292 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
293 C->set_node_notes_at(idx, nn);
294 }
296 // Shared initialization code.
297 inline int Node::Init(int req, Compile* C) {
298 assert(Compile::current() == C, "must use operator new(Compile*)");
299 int idx = C->next_unique();
301 // Allocate memory for the necessary number of edges.
302 if (req > 0) {
303 // Allocate space for _in array to have double alignment.
304 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
305 #ifdef ASSERT
306 _in[req-1] = this; // magic cookie for assertion check
307 #endif
308 }
309 // If there are default notes floating around, capture them:
310 Node_Notes* nn = C->default_node_notes();
311 if (nn != NULL) init_node_notes(C, idx, nn);
313 // Note: At this point, C is dead,
314 // and we begin to initialize the new Node.
316 _cnt = _max = req;
317 _outcnt = _outmax = 0;
318 _class_id = Class_Node;
319 _flags = 0;
320 _out = NO_OUT_ARRAY;
321 return idx;
322 }
324 //------------------------------Node-------------------------------------------
325 // Create a Node, with a given number of required edges.
326 Node::Node(uint req)
327 : _idx(IDX_INIT(req))
328 {
329 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
330 debug_only( verify_construction() );
331 NOT_PRODUCT(nodes_created++);
332 if (req == 0) {
333 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
334 _in = NULL;
335 } else {
336 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
337 Node** to = _in;
338 for(uint i = 0; i < req; i++) {
339 to[i] = NULL;
340 }
341 }
342 }
344 //------------------------------Node-------------------------------------------
345 Node::Node(Node *n0)
346 : _idx(IDX_INIT(1))
347 {
348 debug_only( verify_construction() );
349 NOT_PRODUCT(nodes_created++);
350 // Assert we allocated space for input array already
351 assert( _in[0] == this, "Must pass arg count to 'new'" );
352 assert( is_not_dead(n0), "can not use dead node");
353 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
354 }
356 //------------------------------Node-------------------------------------------
357 Node::Node(Node *n0, Node *n1)
358 : _idx(IDX_INIT(2))
359 {
360 debug_only( verify_construction() );
361 NOT_PRODUCT(nodes_created++);
362 // Assert we allocated space for input array already
363 assert( _in[1] == this, "Must pass arg count to 'new'" );
364 assert( is_not_dead(n0), "can not use dead node");
365 assert( is_not_dead(n1), "can not use dead node");
366 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
367 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
368 }
370 //------------------------------Node-------------------------------------------
371 Node::Node(Node *n0, Node *n1, Node *n2)
372 : _idx(IDX_INIT(3))
373 {
374 debug_only( verify_construction() );
375 NOT_PRODUCT(nodes_created++);
376 // Assert we allocated space for input array already
377 assert( _in[2] == this, "Must pass arg count to 'new'" );
378 assert( is_not_dead(n0), "can not use dead node");
379 assert( is_not_dead(n1), "can not use dead node");
380 assert( is_not_dead(n2), "can not use dead node");
381 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
382 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
383 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
384 }
386 //------------------------------Node-------------------------------------------
387 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
388 : _idx(IDX_INIT(4))
389 {
390 debug_only( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
392 // Assert we allocated space for input array already
393 assert( _in[3] == this, "Must pass arg count to 'new'" );
394 assert( is_not_dead(n0), "can not use dead node");
395 assert( is_not_dead(n1), "can not use dead node");
396 assert( is_not_dead(n2), "can not use dead node");
397 assert( is_not_dead(n3), "can not use dead node");
398 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
399 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
400 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
401 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
402 }
404 //------------------------------Node-------------------------------------------
405 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
406 : _idx(IDX_INIT(5))
407 {
408 debug_only( verify_construction() );
409 NOT_PRODUCT(nodes_created++);
410 // Assert we allocated space for input array already
411 assert( _in[4] == this, "Must pass arg count to 'new'" );
412 assert( is_not_dead(n0), "can not use dead node");
413 assert( is_not_dead(n1), "can not use dead node");
414 assert( is_not_dead(n2), "can not use dead node");
415 assert( is_not_dead(n3), "can not use dead node");
416 assert( is_not_dead(n4), "can not use dead node");
417 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
418 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
419 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
420 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
421 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
422 }
424 //------------------------------Node-------------------------------------------
425 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
426 Node *n4, Node *n5)
427 : _idx(IDX_INIT(6))
428 {
429 debug_only( verify_construction() );
430 NOT_PRODUCT(nodes_created++);
431 // Assert we allocated space for input array already
432 assert( _in[5] == this, "Must pass arg count to 'new'" );
433 assert( is_not_dead(n0), "can not use dead node");
434 assert( is_not_dead(n1), "can not use dead node");
435 assert( is_not_dead(n2), "can not use dead node");
436 assert( is_not_dead(n3), "can not use dead node");
437 assert( is_not_dead(n4), "can not use dead node");
438 assert( is_not_dead(n5), "can not use dead node");
439 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
444 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
445 }
447 //------------------------------Node-------------------------------------------
448 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
449 Node *n4, Node *n5, Node *n6)
450 : _idx(IDX_INIT(7))
451 {
452 debug_only( verify_construction() );
453 NOT_PRODUCT(nodes_created++);
454 // Assert we allocated space for input array already
455 assert( _in[6] == this, "Must pass arg count to 'new'" );
456 assert( is_not_dead(n0), "can not use dead node");
457 assert( is_not_dead(n1), "can not use dead node");
458 assert( is_not_dead(n2), "can not use dead node");
459 assert( is_not_dead(n3), "can not use dead node");
460 assert( is_not_dead(n4), "can not use dead node");
461 assert( is_not_dead(n5), "can not use dead node");
462 assert( is_not_dead(n6), "can not use dead node");
463 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
464 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
465 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
466 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
467 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
468 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
469 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
470 }
473 //------------------------------clone------------------------------------------
474 // Clone a Node.
475 Node *Node::clone() const {
476 Compile* C = Compile::current();
477 uint s = size_of(); // Size of inherited Node
478 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
479 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
480 // Set the new input pointer array
481 n->_in = (Node**)(((char*)n)+s);
482 // Cannot share the old output pointer array, so kill it
483 n->_out = NO_OUT_ARRAY;
484 // And reset the counters to 0
485 n->_outcnt = 0;
486 n->_outmax = 0;
487 // Unlock this guy, since he is not in any hash table.
488 debug_only(n->_hash_lock = 0);
489 // Walk the old node's input list to duplicate its edges
490 uint i;
491 for( i = 0; i < len(); i++ ) {
492 Node *x = in(i);
493 n->_in[i] = x;
494 if (x != NULL) x->add_out(n);
495 }
496 if (is_macro())
497 C->add_macro_node(n);
498 if (is_expensive())
499 C->add_expensive_node(n);
501 n->set_idx(C->next_unique()); // Get new unique index as well
502 debug_only( n->verify_construction() );
503 NOT_PRODUCT(nodes_created++);
504 // Do not patch over the debug_idx of a clone, because it makes it
505 // impossible to break on the clone's moment of creation.
506 //debug_only( n->set_debug_idx( debug_idx() ) );
508 C->copy_node_notes_to(n, (Node*) this);
510 // MachNode clone
511 uint nopnds;
512 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
513 MachNode *mach = n->as_Mach();
514 MachNode *mthis = this->as_Mach();
515 // Get address of _opnd_array.
516 // It should be the same offset since it is the clone of this node.
517 MachOper **from = mthis->_opnds;
518 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
519 pointer_delta((const void*)from,
520 (const void*)(&mthis->_opnds), 1));
521 mach->_opnds = to;
522 for ( uint i = 0; i < nopnds; ++i ) {
523 to[i] = from[i]->clone(C);
524 }
525 }
526 // cloning CallNode may need to clone JVMState
527 if (n->is_Call()) {
528 n->as_Call()->clone_jvms(C);
529 }
530 if (n->is_SafePoint()) {
531 n->as_SafePoint()->clone_replaced_nodes();
532 }
533 return n; // Return the clone
534 }
536 //---------------------------setup_is_top--------------------------------------
537 // Call this when changing the top node, to reassert the invariants
538 // required by Node::is_top. See Compile::set_cached_top_node.
539 void Node::setup_is_top() {
540 if (this == (Node*)Compile::current()->top()) {
541 // This node has just become top. Kill its out array.
542 _outcnt = _outmax = 0;
543 _out = NULL; // marker value for top
544 assert(is_top(), "must be top");
545 } else {
546 if (_out == NULL) _out = NO_OUT_ARRAY;
547 assert(!is_top(), "must not be top");
548 }
549 }
552 //------------------------------~Node------------------------------------------
553 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
554 extern int reclaim_idx ;
555 extern int reclaim_in ;
556 extern int reclaim_node;
557 void Node::destruct() {
558 // Eagerly reclaim unique Node numberings
559 Compile* compile = Compile::current();
560 if ((uint)_idx+1 == compile->unique()) {
561 compile->set_unique(compile->unique()-1);
562 #ifdef ASSERT
563 reclaim_idx++;
564 #endif
565 }
566 // Clear debug info:
567 Node_Notes* nn = compile->node_notes_at(_idx);
568 if (nn != NULL) nn->clear();
569 // Walk the input array, freeing the corresponding output edges
570 _cnt = _max; // forget req/prec distinction
571 uint i;
572 for( i = 0; i < _max; i++ ) {
573 set_req(i, NULL);
574 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
575 }
576 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
577 // See if the input array was allocated just prior to the object
578 int edge_size = _max*sizeof(void*);
579 int out_edge_size = _outmax*sizeof(void*);
580 char *edge_end = ((char*)_in) + edge_size;
581 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
582 char *out_edge_end = out_array + out_edge_size;
583 int node_size = size_of();
585 // Free the output edge array
586 if (out_edge_size > 0) {
587 #ifdef ASSERT
588 if( out_edge_end == compile->node_arena()->hwm() )
589 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
590 #endif
591 compile->node_arena()->Afree(out_array, out_edge_size);
592 }
594 // Free the input edge array and the node itself
595 if( edge_end == (char*)this ) {
596 #ifdef ASSERT
597 if( edge_end+node_size == compile->node_arena()->hwm() ) {
598 reclaim_in += edge_size;
599 reclaim_node+= node_size;
600 }
601 #else
602 // It was; free the input array and object all in one hit
603 compile->node_arena()->Afree(_in,edge_size+node_size);
604 #endif
605 } else {
607 // Free just the input array
608 #ifdef ASSERT
609 if( edge_end == compile->node_arena()->hwm() )
610 reclaim_in += edge_size;
611 #endif
612 compile->node_arena()->Afree(_in,edge_size);
614 // Free just the object
615 #ifdef ASSERT
616 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
617 reclaim_node+= node_size;
618 #else
619 compile->node_arena()->Afree(this,node_size);
620 #endif
621 }
622 if (is_macro()) {
623 compile->remove_macro_node(this);
624 }
625 if (is_expensive()) {
626 compile->remove_expensive_node(this);
627 }
628 if (is_SafePoint()) {
629 as_SafePoint()->delete_replaced_nodes();
630 }
631 #ifdef ASSERT
632 // We will not actually delete the storage, but we'll make the node unusable.
633 *(address*)this = badAddress; // smash the C++ vtbl, probably
634 _in = _out = (Node**) badAddress;
635 _max = _cnt = _outmax = _outcnt = 0;
636 #endif
637 }
639 //------------------------------grow-------------------------------------------
640 // Grow the input array, making space for more edges
641 void Node::grow( uint len ) {
642 Arena* arena = Compile::current()->node_arena();
643 uint new_max = _max;
644 if( new_max == 0 ) {
645 _max = 4;
646 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
647 Node** to = _in;
648 to[0] = NULL;
649 to[1] = NULL;
650 to[2] = NULL;
651 to[3] = NULL;
652 return;
653 }
654 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
655 // Trimming to limit allows a uint8 to handle up to 255 edges.
656 // Previously I was using only powers-of-2 which peaked at 128 edges.
657 //if( new_max >= limit ) new_max = limit-1;
658 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
659 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
660 _max = new_max; // Record new max length
661 // This assertion makes sure that Node::_max is wide enough to
662 // represent the numerical value of new_max.
663 assert(_max == new_max && _max > len, "int width of _max is too small");
664 }
666 //-----------------------------out_grow----------------------------------------
667 // Grow the input array, making space for more edges
668 void Node::out_grow( uint len ) {
669 assert(!is_top(), "cannot grow a top node's out array");
670 Arena* arena = Compile::current()->node_arena();
671 uint new_max = _outmax;
672 if( new_max == 0 ) {
673 _outmax = 4;
674 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
675 return;
676 }
677 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
678 // Trimming to limit allows a uint8 to handle up to 255 edges.
679 // Previously I was using only powers-of-2 which peaked at 128 edges.
680 //if( new_max >= limit ) new_max = limit-1;
681 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
682 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
683 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
684 _outmax = new_max; // Record new max length
685 // This assertion makes sure that Node::_max is wide enough to
686 // represent the numerical value of new_max.
687 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
688 }
690 #ifdef ASSERT
691 //------------------------------is_dead----------------------------------------
692 bool Node::is_dead() const {
693 // Mach and pinch point nodes may look like dead.
694 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
695 return false;
696 for( uint i = 0; i < _max; i++ )
697 if( _in[i] != NULL )
698 return false;
699 dump();
700 return true;
701 }
702 #endif
705 //------------------------------is_unreachable---------------------------------
706 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
707 assert(!is_Mach(), "doesn't work with MachNodes");
708 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
709 }
711 //------------------------------add_req----------------------------------------
712 // Add a new required input at the end
713 void Node::add_req( Node *n ) {
714 assert( is_not_dead(n), "can not use dead node");
716 // Look to see if I can move precedence down one without reallocating
717 if( (_cnt >= _max) || (in(_max-1) != NULL) )
718 grow( _max+1 );
720 // Find a precedence edge to move
721 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
722 uint i;
723 for( i=_cnt; i<_max; i++ )
724 if( in(i) == NULL ) // Find the NULL at end of prec edge list
725 break; // There must be one, since we grew the array
726 _in[i] = in(_cnt); // Move prec over, making space for req edge
727 }
728 _in[_cnt++] = n; // Stuff over old prec edge
729 if (n != NULL) n->add_out((Node *)this);
730 }
732 //---------------------------add_req_batch-------------------------------------
733 // Add a new required input at the end
734 void Node::add_req_batch( Node *n, uint m ) {
735 assert( is_not_dead(n), "can not use dead node");
736 // check various edge cases
737 if ((int)m <= 1) {
738 assert((int)m >= 0, "oob");
739 if (m != 0) add_req(n);
740 return;
741 }
743 // Look to see if I can move precedence down one without reallocating
744 if( (_cnt+m) > _max || _in[_max-m] )
745 grow( _max+m );
747 // Find a precedence edge to move
748 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
749 uint i;
750 for( i=_cnt; i<_max; i++ )
751 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
752 break; // There must be one, since we grew the array
753 // Slide all the precs over by m positions (assume #prec << m).
754 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
755 }
757 // Stuff over the old prec edges
758 for(uint i=0; i<m; i++ ) {
759 _in[_cnt++] = n;
760 }
762 // Insert multiple out edges on the node.
763 if (n != NULL && !n->is_top()) {
764 for(uint i=0; i<m; i++ ) {
765 n->add_out((Node *)this);
766 }
767 }
768 }
770 //------------------------------del_req----------------------------------------
771 // Delete the required edge and compact the edge array
772 void Node::del_req( uint idx ) {
773 assert( idx < _cnt, "oob");
774 assert( !VerifyHashTableKeys || _hash_lock == 0,
775 "remove node from hash table before modifying it");
776 // First remove corresponding def-use edge
777 Node *n = in(idx);
778 if (n != NULL) n->del_out((Node *)this);
779 _in[idx] = in(--_cnt); // Compact the array
780 _in[_cnt] = NULL; // NULL out emptied slot
781 }
783 //------------------------------del_req_ordered--------------------------------
784 // Delete the required edge and compact the edge array with preserved order
785 void Node::del_req_ordered( uint idx ) {
786 assert( idx < _cnt, "oob");
787 assert( !VerifyHashTableKeys || _hash_lock == 0,
788 "remove node from hash table before modifying it");
789 // First remove corresponding def-use edge
790 Node *n = in(idx);
791 if (n != NULL) n->del_out((Node *)this);
792 if (idx < _cnt - 1) { // Not last edge ?
793 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
794 }
795 _in[--_cnt] = NULL; // NULL out emptied slot
796 }
798 //------------------------------ins_req----------------------------------------
799 // Insert a new required input at the end
800 void Node::ins_req( uint idx, Node *n ) {
801 assert( is_not_dead(n), "can not use dead node");
802 add_req(NULL); // Make space
803 assert( idx < _max, "Must have allocated enough space");
804 // Slide over
805 if(_cnt-idx-1 > 0) {
806 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
807 }
808 _in[idx] = n; // Stuff over old required edge
809 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
810 }
812 //-----------------------------find_edge---------------------------------------
813 int Node::find_edge(Node* n) {
814 for (uint i = 0; i < len(); i++) {
815 if (_in[i] == n) return i;
816 }
817 return -1;
818 }
820 //----------------------------replace_edge-------------------------------------
821 int Node::replace_edge(Node* old, Node* neww) {
822 if (old == neww) return 0; // nothing to do
823 uint nrep = 0;
824 for (uint i = 0; i < len(); i++) {
825 if (in(i) == old) {
826 if (i < req())
827 set_req(i, neww);
828 else
829 set_prec(i, neww);
830 nrep++;
831 }
832 }
833 return nrep;
834 }
836 /**
837 * Replace input edges in the range pointing to 'old' node.
838 */
839 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
840 if (old == neww) return 0; // nothing to do
841 uint nrep = 0;
842 for (int i = start; i < end; i++) {
843 if (in(i) == old) {
844 set_req(i, neww);
845 nrep++;
846 }
847 }
848 return nrep;
849 }
851 //-------------------------disconnect_inputs-----------------------------------
852 // NULL out all inputs to eliminate incoming Def-Use edges.
853 // Return the number of edges between 'n' and 'this'
854 int Node::disconnect_inputs(Node *n, Compile* C) {
855 int edges_to_n = 0;
857 uint cnt = req();
858 for( uint i = 0; i < cnt; ++i ) {
859 if( in(i) == 0 ) continue;
860 if( in(i) == n ) ++edges_to_n;
861 set_req(i, NULL);
862 }
863 // Remove precedence edges if any exist
864 // Note: Safepoints may have precedence edges, even during parsing
865 if( (req() != len()) && (in(req()) != NULL) ) {
866 uint max = len();
867 for( uint i = 0; i < max; ++i ) {
868 if( in(i) == 0 ) continue;
869 if( in(i) == n ) ++edges_to_n;
870 set_prec(i, NULL);
871 }
872 }
874 // Node::destruct requires all out edges be deleted first
875 // debug_only(destruct();) // no reuse benefit expected
876 if (edges_to_n == 0) {
877 C->record_dead_node(_idx);
878 }
879 return edges_to_n;
880 }
882 //-----------------------------uncast---------------------------------------
883 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
884 // Strip away casting. (It is depth-limited.)
885 Node* Node::uncast() const {
886 // Should be inline:
887 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
888 if (is_ConstraintCast() || is_CheckCastPP())
889 return uncast_helper(this);
890 else
891 return (Node*) this;
892 }
894 //---------------------------uncast_helper-------------------------------------
895 Node* Node::uncast_helper(const Node* p) {
896 #ifdef ASSERT
897 uint depth_count = 0;
898 const Node* orig_p = p;
899 #endif
901 while (true) {
902 #ifdef ASSERT
903 if (depth_count >= K) {
904 orig_p->dump(4);
905 if (p != orig_p)
906 p->dump(1);
907 }
908 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
909 #endif
910 if (p == NULL || p->req() != 2) {
911 break;
912 } else if (p->is_ConstraintCast()) {
913 p = p->in(1);
914 } else if (p->is_CheckCastPP()) {
915 p = p->in(1);
916 } else {
917 break;
918 }
919 }
920 return (Node*) p;
921 }
923 //------------------------------add_prec---------------------------------------
924 // Add a new precedence input. Precedence inputs are unordered, with
925 // duplicates removed and NULLs packed down at the end.
926 void Node::add_prec( Node *n ) {
927 assert( is_not_dead(n), "can not use dead node");
929 // Check for NULL at end
930 if( _cnt >= _max || in(_max-1) )
931 grow( _max+1 );
933 // Find a precedence edge to move
934 uint i = _cnt;
935 while( in(i) != NULL ) i++;
936 _in[i] = n; // Stuff prec edge over NULL
937 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
938 }
940 //------------------------------rm_prec----------------------------------------
941 // Remove a precedence input. Precedence inputs are unordered, with
942 // duplicates removed and NULLs packed down at the end.
943 void Node::rm_prec( uint j ) {
945 // Find end of precedence list to pack NULLs
946 uint i;
947 for( i=j; i<_max; i++ )
948 if( !_in[i] ) // Find the NULL at end of prec edge list
949 break;
950 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
951 _in[j] = _in[--i]; // Move last element over removed guy
952 _in[i] = NULL; // NULL out last element
953 }
955 //------------------------------size_of----------------------------------------
956 uint Node::size_of() const { return sizeof(*this); }
958 //------------------------------ideal_reg--------------------------------------
959 uint Node::ideal_reg() const { return 0; }
961 //------------------------------jvms-------------------------------------------
962 JVMState* Node::jvms() const { return NULL; }
964 #ifdef ASSERT
965 //------------------------------jvms-------------------------------------------
966 bool Node::verify_jvms(const JVMState* using_jvms) const {
967 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
968 if (jvms == using_jvms) return true;
969 }
970 return false;
971 }
973 //------------------------------init_NodeProperty------------------------------
974 void Node::init_NodeProperty() {
975 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
976 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
977 }
978 #endif
980 //------------------------------format-----------------------------------------
981 // Print as assembly
982 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
983 //------------------------------emit-------------------------------------------
984 // Emit bytes starting at parameter 'ptr'.
985 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
986 //------------------------------size-------------------------------------------
987 // Size of instruction in bytes
988 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
990 //------------------------------CFG Construction-------------------------------
991 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
992 // Goto and Return.
993 const Node *Node::is_block_proj() const { return 0; }
995 // Minimum guaranteed type
996 const Type *Node::bottom_type() const { return Type::BOTTOM; }
999 //------------------------------raise_bottom_type------------------------------
1000 // Get the worst-case Type output for this Node.
1001 void Node::raise_bottom_type(const Type* new_type) {
1002 if (is_Type()) {
1003 TypeNode *n = this->as_Type();
1004 if (VerifyAliases) {
1005 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1006 }
1007 n->set_type(new_type);
1008 } else if (is_Load()) {
1009 LoadNode *n = this->as_Load();
1010 if (VerifyAliases) {
1011 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1012 }
1013 n->set_type(new_type);
1014 }
1015 }
1017 //------------------------------Identity---------------------------------------
1018 // Return a node that the given node is equivalent to.
1019 Node *Node::Identity( PhaseTransform * ) {
1020 return this; // Default to no identities
1021 }
1023 //------------------------------Value------------------------------------------
1024 // Compute a new Type for a node using the Type of the inputs.
1025 const Type *Node::Value( PhaseTransform * ) const {
1026 return bottom_type(); // Default to worst-case Type
1027 }
1029 //------------------------------Ideal------------------------------------------
1030 //
1031 // 'Idealize' the graph rooted at this Node.
1032 //
1033 // In order to be efficient and flexible there are some subtle invariants
1034 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1035 // these invariants, although its too slow to have on by default. If you are
1036 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1037 //
1038 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1039 // pointer. If ANY change is made, it must return the root of the reshaped
1040 // graph - even if the root is the same Node. Example: swapping the inputs
1041 // to an AddINode gives the same answer and same root, but you still have to
1042 // return the 'this' pointer instead of NULL.
1043 //
1044 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1045 // Identity call to return an old Node; basically if Identity can find
1046 // another Node have the Ideal call make no change and return NULL.
1047 // Example: AddINode::Ideal must check for add of zero; in this case it
1048 // returns NULL instead of doing any graph reshaping.
1049 //
1050 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1051 // sharing there may be other users of the old Nodes relying on their current
1052 // semantics. Modifying them will break the other users.
1053 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1054 // "X+3" unchanged in case it is shared.
1055 //
1056 // If you modify the 'this' pointer's inputs, you should use
1057 // 'set_req'. If you are making a new Node (either as the new root or
1058 // some new internal piece) you may use 'init_req' to set the initial
1059 // value. You can make a new Node with either 'new' or 'clone'. In
1060 // either case, def-use info is correctly maintained.
1061 //
1062 // Example: reshape "(X+3)+4" into "X+7":
1063 // set_req(1, in(1)->in(1));
1064 // set_req(2, phase->intcon(7));
1065 // return this;
1066 // Example: reshape "X*4" into "X<<2"
1067 // return new (C) LShiftINode(in(1), phase->intcon(2));
1068 //
1069 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1070 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1071 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1072 // return new (C) AddINode(shift, in(1));
1073 //
1074 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1075 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1076 // The Right Thing with def-use info.
1077 //
1078 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1079 // graph uses the 'this' Node it must be the root. If you want a Node with
1080 // the same Opcode as the 'this' pointer use 'clone'.
1081 //
1082 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1083 return NULL; // Default to being Ideal already
1084 }
1086 // Some nodes have specific Ideal subgraph transformations only if they are
1087 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1088 // for the transformations to happen.
1089 bool Node::has_special_unique_user() const {
1090 assert(outcnt() == 1, "match only for unique out");
1091 Node* n = unique_out();
1092 int op = Opcode();
1093 if( this->is_Store() ) {
1094 // Condition for back-to-back stores folding.
1095 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1096 } else if (this->is_Load()) {
1097 // Condition for removing an unused LoadNode from the MemBarAcquire precedence input
1098 return n->Opcode() == Op_MemBarAcquire;
1099 } else if( op == Op_AddL ) {
1100 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1101 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1102 } else if( op == Op_SubI || op == Op_SubL ) {
1103 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1104 return n->Opcode() == op && n->in(2) == this;
1105 }
1106 return false;
1107 };
1109 //--------------------------find_exact_control---------------------------------
1110 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1111 Node* Node::find_exact_control(Node* ctrl) {
1112 if (ctrl == NULL && this->is_Region())
1113 ctrl = this->as_Region()->is_copy();
1115 if (ctrl != NULL && ctrl->is_CatchProj()) {
1116 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1117 ctrl = ctrl->in(0);
1118 if (ctrl != NULL && !ctrl->is_top())
1119 ctrl = ctrl->in(0);
1120 }
1122 if (ctrl != NULL && ctrl->is_Proj())
1123 ctrl = ctrl->in(0);
1125 return ctrl;
1126 }
1128 //--------------------------dominates------------------------------------------
1129 // Helper function for MemNode::all_controls_dominate().
1130 // Check if 'this' control node dominates or equal to 'sub' control node.
1131 // We already know that if any path back to Root or Start reaches 'this',
1132 // then all paths so, so this is a simple search for one example,
1133 // not an exhaustive search for a counterexample.
1134 bool Node::dominates(Node* sub, Node_List &nlist) {
1135 assert(this->is_CFG(), "expecting control");
1136 assert(sub != NULL && sub->is_CFG(), "expecting control");
1138 // detect dead cycle without regions
1139 int iterations_without_region_limit = DominatorSearchLimit;
1141 Node* orig_sub = sub;
1142 Node* dom = this;
1143 bool met_dom = false;
1144 nlist.clear();
1146 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1147 // After seeing 'dom', continue up to Root or Start.
1148 // If we hit a region (backward split point), it may be a loop head.
1149 // Keep going through one of the region's inputs. If we reach the
1150 // same region again, go through a different input. Eventually we
1151 // will either exit through the loop head, or give up.
1152 // (If we get confused, break out and return a conservative 'false'.)
1153 while (sub != NULL) {
1154 if (sub->is_top()) break; // Conservative answer for dead code.
1155 if (sub == dom) {
1156 if (nlist.size() == 0) {
1157 // No Region nodes except loops were visited before and the EntryControl
1158 // path was taken for loops: it did not walk in a cycle.
1159 return true;
1160 } else if (met_dom) {
1161 break; // already met before: walk in a cycle
1162 } else {
1163 // Region nodes were visited. Continue walk up to Start or Root
1164 // to make sure that it did not walk in a cycle.
1165 met_dom = true; // first time meet
1166 iterations_without_region_limit = DominatorSearchLimit; // Reset
1167 }
1168 }
1169 if (sub->is_Start() || sub->is_Root()) {
1170 // Success if we met 'dom' along a path to Start or Root.
1171 // We assume there are no alternative paths that avoid 'dom'.
1172 // (This assumption is up to the caller to ensure!)
1173 return met_dom;
1174 }
1175 Node* up = sub->in(0);
1176 // Normalize simple pass-through regions and projections:
1177 up = sub->find_exact_control(up);
1178 // If sub == up, we found a self-loop. Try to push past it.
1179 if (sub == up && sub->is_Loop()) {
1180 // Take loop entry path on the way up to 'dom'.
1181 up = sub->in(1); // in(LoopNode::EntryControl);
1182 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1183 // Always take in(1) path on the way up to 'dom' for clone regions
1184 // (with only one input) or regions which merge > 2 paths
1185 // (usually used to merge fast/slow paths).
1186 up = sub->in(1);
1187 } else if (sub == up && sub->is_Region()) {
1188 // Try both paths for Regions with 2 input paths (it may be a loop head).
1189 // It could give conservative 'false' answer without information
1190 // which region's input is the entry path.
1191 iterations_without_region_limit = DominatorSearchLimit; // Reset
1193 bool region_was_visited_before = false;
1194 // Was this Region node visited before?
1195 // If so, we have reached it because we accidentally took a
1196 // loop-back edge from 'sub' back into the body of the loop,
1197 // and worked our way up again to the loop header 'sub'.
1198 // So, take the first unexplored path on the way up to 'dom'.
1199 for (int j = nlist.size() - 1; j >= 0; j--) {
1200 intptr_t ni = (intptr_t)nlist.at(j);
1201 Node* visited = (Node*)(ni & ~1);
1202 bool visited_twice_already = ((ni & 1) != 0);
1203 if (visited == sub) {
1204 if (visited_twice_already) {
1205 // Visited 2 paths, but still stuck in loop body. Give up.
1206 return false;
1207 }
1208 // The Region node was visited before only once.
1209 // (We will repush with the low bit set, below.)
1210 nlist.remove(j);
1211 // We will find a new edge and re-insert.
1212 region_was_visited_before = true;
1213 break;
1214 }
1215 }
1217 // Find an incoming edge which has not been seen yet; walk through it.
1218 assert(up == sub, "");
1219 uint skip = region_was_visited_before ? 1 : 0;
1220 for (uint i = 1; i < sub->req(); i++) {
1221 Node* in = sub->in(i);
1222 if (in != NULL && !in->is_top() && in != sub) {
1223 if (skip == 0) {
1224 up = in;
1225 break;
1226 }
1227 --skip; // skip this nontrivial input
1228 }
1229 }
1231 // Set 0 bit to indicate that both paths were taken.
1232 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1233 }
1235 if (up == sub) {
1236 break; // some kind of tight cycle
1237 }
1238 if (up == orig_sub && met_dom) {
1239 // returned back after visiting 'dom'
1240 break; // some kind of cycle
1241 }
1242 if (--iterations_without_region_limit < 0) {
1243 break; // dead cycle
1244 }
1245 sub = up;
1246 }
1248 // Did not meet Root or Start node in pred. chain.
1249 // Conservative answer for dead code.
1250 return false;
1251 }
1253 //------------------------------remove_dead_region-----------------------------
1254 // This control node is dead. Follow the subgraph below it making everything
1255 // using it dead as well. This will happen normally via the usual IterGVN
1256 // worklist but this call is more efficient. Do not update use-def info
1257 // inside the dead region, just at the borders.
1258 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1259 // Con's are a popular node to re-hit in the hash table again.
1260 if( dead->is_Con() ) return;
1262 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1263 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1264 Node_List nstack(Thread::current()->resource_area());
1266 Node *top = igvn->C->top();
1267 nstack.push(dead);
1268 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1270 while (nstack.size() > 0) {
1271 dead = nstack.pop();
1272 if (dead->outcnt() > 0) {
1273 // Keep dead node on stack until all uses are processed.
1274 nstack.push(dead);
1275 // For all Users of the Dead... ;-)
1276 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1277 Node* use = dead->last_out(k);
1278 igvn->hash_delete(use); // Yank from hash table prior to mod
1279 if (use->in(0) == dead) { // Found another dead node
1280 assert (!use->is_Con(), "Control for Con node should be Root node.");
1281 use->set_req(0, top); // Cut dead edge to prevent processing
1282 nstack.push(use); // the dead node again.
1283 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1284 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1285 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1286 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1287 use->set_req(0, top); // Cut self edge
1288 nstack.push(use);
1289 } else { // Else found a not-dead user
1290 // Dead if all inputs are top or null
1291 bool dead_use = !use->is_Root(); // Keep empty graph alive
1292 for (uint j = 1; j < use->req(); j++) {
1293 Node* in = use->in(j);
1294 if (in == dead) { // Turn all dead inputs into TOP
1295 use->set_req(j, top);
1296 } else if (in != NULL && !in->is_top()) {
1297 dead_use = false;
1298 }
1299 }
1300 if (dead_use) {
1301 if (use->is_Region()) {
1302 use->set_req(0, top); // Cut self edge
1303 }
1304 nstack.push(use);
1305 } else {
1306 igvn->_worklist.push(use);
1307 }
1308 }
1309 // Refresh the iterator, since any number of kills might have happened.
1310 k = dead->last_outs(kmin);
1311 }
1312 } else { // (dead->outcnt() == 0)
1313 // Done with outputs.
1314 igvn->hash_delete(dead);
1315 igvn->_worklist.remove(dead);
1316 igvn->set_type(dead, Type::TOP);
1317 if (dead->is_macro()) {
1318 igvn->C->remove_macro_node(dead);
1319 }
1320 if (dead->is_expensive()) {
1321 igvn->C->remove_expensive_node(dead);
1322 }
1323 igvn->C->record_dead_node(dead->_idx);
1324 // Kill all inputs to the dead guy
1325 for (uint i=0; i < dead->req(); i++) {
1326 Node *n = dead->in(i); // Get input to dead guy
1327 if (n != NULL && !n->is_top()) { // Input is valid?
1328 dead->set_req(i, top); // Smash input away
1329 if (n->outcnt() == 0) { // Input also goes dead?
1330 if (!n->is_Con())
1331 nstack.push(n); // Clear it out as well
1332 } else if (n->outcnt() == 1 &&
1333 n->has_special_unique_user()) {
1334 igvn->add_users_to_worklist( n );
1335 } else if (n->outcnt() <= 2 && n->is_Store()) {
1336 // Push store's uses on worklist to enable folding optimization for
1337 // store/store and store/load to the same address.
1338 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1339 // and remove_globally_dead_node().
1340 igvn->add_users_to_worklist( n );
1341 }
1342 }
1343 }
1344 } // (dead->outcnt() == 0)
1345 } // while (nstack.size() > 0) for outputs
1346 return;
1347 }
1349 //------------------------------remove_dead_region-----------------------------
1350 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1351 Node *n = in(0);
1352 if( !n ) return false;
1353 // Lost control into this guy? I.e., it became unreachable?
1354 // Aggressively kill all unreachable code.
1355 if (can_reshape && n->is_top()) {
1356 kill_dead_code(this, phase->is_IterGVN());
1357 return false; // Node is dead.
1358 }
1360 if( n->is_Region() && n->as_Region()->is_copy() ) {
1361 Node *m = n->nonnull_req();
1362 set_req(0, m);
1363 return true;
1364 }
1365 return false;
1366 }
1368 //------------------------------Ideal_DU_postCCP-------------------------------
1369 // Idealize graph, using DU info. Must clone result into new-space
1370 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1371 return NULL; // Default to no change
1372 }
1374 //------------------------------hash-------------------------------------------
1375 // Hash function over Nodes.
1376 uint Node::hash() const {
1377 uint sum = 0;
1378 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1379 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1380 return (sum>>2) + _cnt + Opcode();
1381 }
1383 //------------------------------cmp--------------------------------------------
1384 // Compare special parts of simple Nodes
1385 uint Node::cmp( const Node &n ) const {
1386 return 1; // Must be same
1387 }
1389 //------------------------------rematerialize-----------------------------------
1390 // Should we clone rather than spill this instruction?
1391 bool Node::rematerialize() const {
1392 if ( is_Mach() )
1393 return this->as_Mach()->rematerialize();
1394 else
1395 return (_flags & Flag_rematerialize) != 0;
1396 }
1398 //------------------------------needs_anti_dependence_check---------------------
1399 // Nodes which use memory without consuming it, hence need antidependences.
1400 bool Node::needs_anti_dependence_check() const {
1401 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1402 return false;
1403 else
1404 return in(1)->bottom_type()->has_memory();
1405 }
1408 // Get an integer constant from a ConNode (or CastIINode).
1409 // Return a default value if there is no apparent constant here.
1410 const TypeInt* Node::find_int_type() const {
1411 if (this->is_Type()) {
1412 return this->as_Type()->type()->isa_int();
1413 } else if (this->is_Con()) {
1414 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1415 return this->bottom_type()->isa_int();
1416 }
1417 return NULL;
1418 }
1420 // Get a pointer constant from a ConstNode.
1421 // Returns the constant if it is a pointer ConstNode
1422 intptr_t Node::get_ptr() const {
1423 assert( Opcode() == Op_ConP, "" );
1424 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1425 }
1427 // Get a narrow oop constant from a ConNNode.
1428 intptr_t Node::get_narrowcon() const {
1429 assert( Opcode() == Op_ConN, "" );
1430 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1431 }
1433 // Get a long constant from a ConNode.
1434 // Return a default value if there is no apparent constant here.
1435 const TypeLong* Node::find_long_type() const {
1436 if (this->is_Type()) {
1437 return this->as_Type()->type()->isa_long();
1438 } else if (this->is_Con()) {
1439 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1440 return this->bottom_type()->isa_long();
1441 }
1442 return NULL;
1443 }
1446 /**
1447 * Return a ptr type for nodes which should have it.
1448 */
1449 const TypePtr* Node::get_ptr_type() const {
1450 const TypePtr* tp = this->bottom_type()->make_ptr();
1451 #ifdef ASSERT
1452 if (tp == NULL) {
1453 this->dump(1);
1454 assert((tp != NULL), "unexpected node type");
1455 }
1456 #endif
1457 return tp;
1458 }
1460 // Get a double constant from a ConstNode.
1461 // Returns the constant if it is a double ConstNode
1462 jdouble Node::getd() const {
1463 assert( Opcode() == Op_ConD, "" );
1464 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1465 }
1467 // Get a float constant from a ConstNode.
1468 // Returns the constant if it is a float ConstNode
1469 jfloat Node::getf() const {
1470 assert( Opcode() == Op_ConF, "" );
1471 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1472 }
1474 #ifndef PRODUCT
1476 //----------------------------NotANode----------------------------------------
1477 // Used in debugging code to avoid walking across dead or uninitialized edges.
1478 static inline bool NotANode(const Node* n) {
1479 if (n == NULL) return true;
1480 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1481 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1482 return false;
1483 }
1486 //------------------------------find------------------------------------------
1487 // Find a neighbor of this Node with the given _idx
1488 // If idx is negative, find its absolute value, following both _in and _out.
1489 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1490 VectorSet* old_space, VectorSet* new_space ) {
1491 int node_idx = (idx >= 0) ? idx : -idx;
1492 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1493 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1494 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1495 if( v->test(n->_idx) ) return;
1496 if( (int)n->_idx == node_idx
1497 debug_only(|| n->debug_idx() == node_idx) ) {
1498 if (result != NULL)
1499 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1500 (uintptr_t)result, (uintptr_t)n, node_idx);
1501 result = n;
1502 }
1503 v->set(n->_idx);
1504 for( uint i=0; i<n->len(); i++ ) {
1505 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1506 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1507 }
1508 // Search along forward edges also:
1509 if (idx < 0 && !only_ctrl) {
1510 for( uint j=0; j<n->outcnt(); j++ ) {
1511 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1512 }
1513 }
1514 #ifdef ASSERT
1515 // Search along debug_orig edges last, checking for cycles
1516 Node* orig = n->debug_orig();
1517 if (orig != NULL) {
1518 do {
1519 if (NotANode(orig)) break;
1520 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1521 orig = orig->debug_orig();
1522 } while (orig != NULL && orig != n->debug_orig());
1523 }
1524 #endif //ASSERT
1525 }
1527 // call this from debugger:
1528 Node* find_node(Node* n, int idx) {
1529 return n->find(idx);
1530 }
1532 //------------------------------find-------------------------------------------
1533 Node* Node::find(int idx) const {
1534 ResourceArea *area = Thread::current()->resource_area();
1535 VectorSet old_space(area), new_space(area);
1536 Node* result = NULL;
1537 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1538 return result;
1539 }
1541 //------------------------------find_ctrl--------------------------------------
1542 // Find an ancestor to this node in the control history with given _idx
1543 Node* Node::find_ctrl(int idx) const {
1544 ResourceArea *area = Thread::current()->resource_area();
1545 VectorSet old_space(area), new_space(area);
1546 Node* result = NULL;
1547 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1548 return result;
1549 }
1550 #endif
1554 #ifndef PRODUCT
1556 // -----------------------------Name-------------------------------------------
1557 extern const char *NodeClassNames[];
1558 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1560 static bool is_disconnected(const Node* n) {
1561 for (uint i = 0; i < n->req(); i++) {
1562 if (n->in(i) != NULL) return false;
1563 }
1564 return true;
1565 }
1567 #ifdef ASSERT
1568 static void dump_orig(Node* orig, outputStream *st) {
1569 Compile* C = Compile::current();
1570 if (NotANode(orig)) orig = NULL;
1571 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1572 if (orig == NULL) return;
1573 st->print(" !orig=");
1574 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1575 if (NotANode(fast)) fast = NULL;
1576 while (orig != NULL) {
1577 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1578 if (discon) st->print("[");
1579 if (!Compile::current()->node_arena()->contains(orig))
1580 st->print("o");
1581 st->print("%d", orig->_idx);
1582 if (discon) st->print("]");
1583 orig = orig->debug_orig();
1584 if (NotANode(orig)) orig = NULL;
1585 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1586 if (orig != NULL) st->print(",");
1587 if (fast != NULL) {
1588 // Step fast twice for each single step of orig:
1589 fast = fast->debug_orig();
1590 if (NotANode(fast)) fast = NULL;
1591 if (fast != NULL && fast != orig) {
1592 fast = fast->debug_orig();
1593 if (NotANode(fast)) fast = NULL;
1594 }
1595 if (fast == orig) {
1596 st->print("...");
1597 break;
1598 }
1599 }
1600 }
1601 }
1603 void Node::set_debug_orig(Node* orig) {
1604 _debug_orig = orig;
1605 if (BreakAtNode == 0) return;
1606 if (NotANode(orig)) orig = NULL;
1607 int trip = 10;
1608 while (orig != NULL) {
1609 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1610 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1611 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1612 BREAKPOINT;
1613 }
1614 orig = orig->debug_orig();
1615 if (NotANode(orig)) orig = NULL;
1616 if (trip-- <= 0) break;
1617 }
1618 }
1619 #endif //ASSERT
1621 //------------------------------dump------------------------------------------
1622 // Dump a Node
1623 void Node::dump(const char* suffix, outputStream *st) const {
1624 Compile* C = Compile::current();
1625 bool is_new = C->node_arena()->contains(this);
1626 C->_in_dump_cnt++;
1627 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1629 // Dump the required and precedence inputs
1630 dump_req(st);
1631 dump_prec(st);
1632 // Dump the outputs
1633 dump_out(st);
1635 if (is_disconnected(this)) {
1636 #ifdef ASSERT
1637 st->print(" [%d]",debug_idx());
1638 dump_orig(debug_orig(), st);
1639 #endif
1640 st->cr();
1641 C->_in_dump_cnt--;
1642 return; // don't process dead nodes
1643 }
1645 // Dump node-specific info
1646 dump_spec(st);
1647 #ifdef ASSERT
1648 // Dump the non-reset _debug_idx
1649 if (Verbose && WizardMode) {
1650 st->print(" [%d]",debug_idx());
1651 }
1652 #endif
1654 const Type *t = bottom_type();
1656 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1657 const TypeInstPtr *toop = t->isa_instptr();
1658 const TypeKlassPtr *tkls = t->isa_klassptr();
1659 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1660 if (klass && klass->is_loaded() && klass->is_interface()) {
1661 st->print(" Interface:");
1662 } else if (toop) {
1663 st->print(" Oop:");
1664 } else if (tkls) {
1665 st->print(" Klass:");
1666 }
1667 t->dump_on(st);
1668 } else if (t == Type::MEMORY) {
1669 st->print(" Memory:");
1670 MemNode::dump_adr_type(this, adr_type(), st);
1671 } else if (Verbose || WizardMode) {
1672 st->print(" Type:");
1673 if (t) {
1674 t->dump_on(st);
1675 } else {
1676 st->print("no type");
1677 }
1678 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1679 // Dump MachSpillcopy vector type.
1680 t->dump_on(st);
1681 }
1682 if (is_new) {
1683 debug_only(dump_orig(debug_orig(), st));
1684 Node_Notes* nn = C->node_notes_at(_idx);
1685 if (nn != NULL && !nn->is_clear()) {
1686 if (nn->jvms() != NULL) {
1687 st->print(" !jvms:");
1688 nn->jvms()->dump_spec(st);
1689 }
1690 }
1691 }
1692 if (suffix) st->print("%s", suffix);
1693 C->_in_dump_cnt--;
1694 }
1696 //------------------------------dump_req--------------------------------------
1697 void Node::dump_req(outputStream *st) const {
1698 // Dump the required input edges
1699 for (uint i = 0; i < req(); i++) { // For all required inputs
1700 Node* d = in(i);
1701 if (d == NULL) {
1702 st->print("_ ");
1703 } else if (NotANode(d)) {
1704 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1705 } else {
1706 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1707 }
1708 }
1709 }
1712 //------------------------------dump_prec-------------------------------------
1713 void Node::dump_prec(outputStream *st) const {
1714 // Dump the precedence edges
1715 int any_prec = 0;
1716 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1717 Node* p = in(i);
1718 if (p != NULL) {
1719 if (!any_prec++) st->print(" |");
1720 if (NotANode(p)) { st->print("NotANode "); continue; }
1721 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1722 }
1723 }
1724 }
1726 //------------------------------dump_out--------------------------------------
1727 void Node::dump_out(outputStream *st) const {
1728 // Delimit the output edges
1729 st->print(" [[");
1730 // Dump the output edges
1731 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1732 Node* u = _out[i];
1733 if (u == NULL) {
1734 st->print("_ ");
1735 } else if (NotANode(u)) {
1736 st->print("NotANode ");
1737 } else {
1738 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1739 }
1740 }
1741 st->print("]] ");
1742 }
1744 //------------------------------dump_nodes-------------------------------------
1745 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1746 Node* s = (Node*)start; // remove const
1747 if (NotANode(s)) return;
1749 uint depth = (uint)ABS(d);
1750 int direction = d;
1751 Compile* C = Compile::current();
1752 GrowableArray <Node *> nstack(C->unique());
1754 nstack.append(s);
1755 int begin = 0;
1756 int end = 0;
1757 for(uint i = 0; i < depth; i++) {
1758 end = nstack.length();
1759 for(int j = begin; j < end; j++) {
1760 Node* tp = nstack.at(j);
1761 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1762 for(uint k = 0; k < limit; k++) {
1763 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1765 if (NotANode(n)) continue;
1766 // do not recurse through top or the root (would reach unrelated stuff)
1767 if (n->is_Root() || n->is_top()) continue;
1768 if (only_ctrl && !n->is_CFG()) continue;
1770 bool on_stack = nstack.contains(n);
1771 if (!on_stack) {
1772 nstack.append(n);
1773 }
1774 }
1775 }
1776 begin = end;
1777 }
1778 end = nstack.length();
1779 if (direction > 0) {
1780 for(int j = end-1; j >= 0; j--) {
1781 nstack.at(j)->dump();
1782 }
1783 } else {
1784 for(int j = 0; j < end; j++) {
1785 nstack.at(j)->dump();
1786 }
1787 }
1788 }
1790 //------------------------------dump-------------------------------------------
1791 void Node::dump(int d) const {
1792 dump_nodes(this, d, false);
1793 }
1795 //------------------------------dump_ctrl--------------------------------------
1796 // Dump a Node's control history to depth
1797 void Node::dump_ctrl(int d) const {
1798 dump_nodes(this, d, true);
1799 }
1801 // VERIFICATION CODE
1802 // For each input edge to a node (ie - for each Use-Def edge), verify that
1803 // there is a corresponding Def-Use edge.
1804 //------------------------------verify_edges-----------------------------------
1805 void Node::verify_edges(Unique_Node_List &visited) {
1806 uint i, j, idx;
1807 int cnt;
1808 Node *n;
1810 // Recursive termination test
1811 if (visited.member(this)) return;
1812 visited.push(this);
1814 // Walk over all input edges, checking for correspondence
1815 for( i = 0; i < len(); i++ ) {
1816 n = in(i);
1817 if (n != NULL && !n->is_top()) {
1818 // Count instances of (Node *)this
1819 cnt = 0;
1820 for (idx = 0; idx < n->_outcnt; idx++ ) {
1821 if (n->_out[idx] == (Node *)this) cnt++;
1822 }
1823 assert( cnt > 0,"Failed to find Def-Use edge." );
1824 // Check for duplicate edges
1825 // walk the input array downcounting the input edges to n
1826 for( j = 0; j < len(); j++ ) {
1827 if( in(j) == n ) cnt--;
1828 }
1829 assert( cnt == 0,"Mismatched edge count.");
1830 } else if (n == NULL) {
1831 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1832 } else {
1833 assert(n->is_top(), "sanity");
1834 // Nothing to check.
1835 }
1836 }
1837 // Recursive walk over all input edges
1838 for( i = 0; i < len(); i++ ) {
1839 n = in(i);
1840 if( n != NULL )
1841 in(i)->verify_edges(visited);
1842 }
1843 }
1845 //------------------------------verify_recur-----------------------------------
1846 static const Node *unique_top = NULL;
1848 void Node::verify_recur(const Node *n, int verify_depth,
1849 VectorSet &old_space, VectorSet &new_space) {
1850 if ( verify_depth == 0 ) return;
1851 if (verify_depth > 0) --verify_depth;
1853 Compile* C = Compile::current();
1855 // Contained in new_space or old_space?
1856 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1857 // Check for visited in the proper space. Numberings are not unique
1858 // across spaces so we need a separate VectorSet for each space.
1859 if( v->test_set(n->_idx) ) return;
1861 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1862 if (C->cached_top_node() == NULL)
1863 C->set_cached_top_node((Node*)n);
1864 assert(C->cached_top_node() == n, "TOP node must be unique");
1865 }
1867 for( uint i = 0; i < n->len(); i++ ) {
1868 Node *x = n->in(i);
1869 if (!x || x->is_top()) continue;
1871 // Verify my input has a def-use edge to me
1872 if (true /*VerifyDefUse*/) {
1873 // Count use-def edges from n to x
1874 int cnt = 0;
1875 for( uint j = 0; j < n->len(); j++ )
1876 if( n->in(j) == x )
1877 cnt++;
1878 // Count def-use edges from x to n
1879 uint max = x->_outcnt;
1880 for( uint k = 0; k < max; k++ )
1881 if (x->_out[k] == n)
1882 cnt--;
1883 assert( cnt == 0, "mismatched def-use edge counts" );
1884 }
1886 verify_recur(x, verify_depth, old_space, new_space);
1887 }
1889 }
1891 //------------------------------verify-----------------------------------------
1892 // Check Def-Use info for my subgraph
1893 void Node::verify() const {
1894 Compile* C = Compile::current();
1895 Node* old_top = C->cached_top_node();
1896 ResourceMark rm;
1897 ResourceArea *area = Thread::current()->resource_area();
1898 VectorSet old_space(area), new_space(area);
1899 verify_recur(this, -1, old_space, new_space);
1900 C->set_cached_top_node(old_top);
1901 }
1902 #endif
1905 //------------------------------walk-------------------------------------------
1906 // Graph walk, with both pre-order and post-order functions
1907 void Node::walk(NFunc pre, NFunc post, void *env) {
1908 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1909 walk_(pre, post, env, visited);
1910 }
1912 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1913 if( visited.test_set(_idx) ) return;
1914 pre(*this,env); // Call the pre-order walk function
1915 for( uint i=0; i<_max; i++ )
1916 if( in(i) ) // Input exists and is not walked?
1917 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1918 post(*this,env); // Call the post-order walk function
1919 }
1921 void Node::nop(Node &, void*) {}
1923 //------------------------------Registers--------------------------------------
1924 // Do we Match on this edge index or not? Generally false for Control
1925 // and true for everything else. Weird for calls & returns.
1926 uint Node::match_edge(uint idx) const {
1927 return idx; // True for other than index 0 (control)
1928 }
1930 static RegMask _not_used_at_all;
1931 // Register classes are defined for specific machines
1932 const RegMask &Node::out_RegMask() const {
1933 ShouldNotCallThis();
1934 return _not_used_at_all;
1935 }
1937 const RegMask &Node::in_RegMask(uint) const {
1938 ShouldNotCallThis();
1939 return _not_used_at_all;
1940 }
1942 //=============================================================================
1943 //-----------------------------------------------------------------------------
1944 void Node_Array::reset( Arena *new_arena ) {
1945 _a->Afree(_nodes,_max*sizeof(Node*));
1946 _max = 0;
1947 _nodes = NULL;
1948 _a = new_arena;
1949 }
1951 //------------------------------clear------------------------------------------
1952 // Clear all entries in _nodes to NULL but keep storage
1953 void Node_Array::clear() {
1954 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1955 }
1957 //-----------------------------------------------------------------------------
1958 void Node_Array::grow( uint i ) {
1959 if( !_max ) {
1960 _max = 1;
1961 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1962 _nodes[0] = NULL;
1963 }
1964 uint old = _max;
1965 while( i >= _max ) _max <<= 1; // Double to fit
1966 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1967 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1968 }
1970 //-----------------------------------------------------------------------------
1971 void Node_Array::insert( uint i, Node *n ) {
1972 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1973 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1974 _nodes[i] = n;
1975 }
1977 //-----------------------------------------------------------------------------
1978 void Node_Array::remove( uint i ) {
1979 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1980 _nodes[_max-1] = NULL;
1981 }
1983 //-----------------------------------------------------------------------------
1984 void Node_Array::sort( C_sort_func_t func) {
1985 qsort( _nodes, _max, sizeof( Node* ), func );
1986 }
1988 //-----------------------------------------------------------------------------
1989 void Node_Array::dump() const {
1990 #ifndef PRODUCT
1991 for( uint i = 0; i < _max; i++ ) {
1992 Node *nn = _nodes[i];
1993 if( nn != NULL ) {
1994 tty->print("%5d--> ",i); nn->dump();
1995 }
1996 }
1997 #endif
1998 }
2000 //--------------------------is_iteratively_computed------------------------------
2001 // Operation appears to be iteratively computed (such as an induction variable)
2002 // It is possible for this operation to return false for a loop-varying
2003 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2004 bool Node::is_iteratively_computed() {
2005 if (ideal_reg()) { // does operation have a result register?
2006 for (uint i = 1; i < req(); i++) {
2007 Node* n = in(i);
2008 if (n != NULL && n->is_Phi()) {
2009 for (uint j = 1; j < n->req(); j++) {
2010 if (n->in(j) == this) {
2011 return true;
2012 }
2013 }
2014 }
2015 }
2016 }
2017 return false;
2018 }
2020 //--------------------------find_similar------------------------------
2021 // Return a node with opcode "opc" and same inputs as "this" if one can
2022 // be found; Otherwise return NULL;
2023 Node* Node::find_similar(int opc) {
2024 if (req() >= 2) {
2025 Node* def = in(1);
2026 if (def && def->outcnt() >= 2) {
2027 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2028 Node* use = def->fast_out(i);
2029 if (use->Opcode() == opc &&
2030 use->req() == req()) {
2031 uint j;
2032 for (j = 0; j < use->req(); j++) {
2033 if (use->in(j) != in(j)) {
2034 break;
2035 }
2036 }
2037 if (j == use->req()) {
2038 return use;
2039 }
2040 }
2041 }
2042 }
2043 }
2044 return NULL;
2045 }
2048 //--------------------------unique_ctrl_out------------------------------
2049 // Return the unique control out if only one. Null if none or more than one.
2050 Node* Node::unique_ctrl_out() {
2051 Node* found = NULL;
2052 for (uint i = 0; i < outcnt(); i++) {
2053 Node* use = raw_out(i);
2054 if (use->is_CFG() && use != this) {
2055 if (found != NULL) return NULL;
2056 found = use;
2057 }
2058 }
2059 return found;
2060 }
2062 //=============================================================================
2063 //------------------------------yank-------------------------------------------
2064 // Find and remove
2065 void Node_List::yank( Node *n ) {
2066 uint i;
2067 for( i = 0; i < _cnt; i++ )
2068 if( _nodes[i] == n )
2069 break;
2071 if( i < _cnt )
2072 _nodes[i] = _nodes[--_cnt];
2073 }
2075 //------------------------------dump-------------------------------------------
2076 void Node_List::dump() const {
2077 #ifndef PRODUCT
2078 for( uint i = 0; i < _cnt; i++ )
2079 if( _nodes[i] ) {
2080 tty->print("%5d--> ",i);
2081 _nodes[i]->dump();
2082 }
2083 #endif
2084 }
2086 //=============================================================================
2087 //------------------------------remove-----------------------------------------
2088 void Unique_Node_List::remove( Node *n ) {
2089 if( _in_worklist[n->_idx] ) {
2090 for( uint i = 0; i < size(); i++ )
2091 if( _nodes[i] == n ) {
2092 map(i,Node_List::pop());
2093 _in_worklist >>= n->_idx;
2094 return;
2095 }
2096 ShouldNotReachHere();
2097 }
2098 }
2100 //-----------------------remove_useless_nodes----------------------------------
2101 // Remove useless nodes from worklist
2102 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2104 for( uint i = 0; i < size(); ++i ) {
2105 Node *n = at(i);
2106 assert( n != NULL, "Did not expect null entries in worklist");
2107 if( ! useful.test(n->_idx) ) {
2108 _in_worklist >>= n->_idx;
2109 map(i,Node_List::pop());
2110 // Node *replacement = Node_List::pop();
2111 // if( i != size() ) { // Check if removing last entry
2112 // _nodes[i] = replacement;
2113 // }
2114 --i; // Visit popped node
2115 // If it was last entry, loop terminates since size() was also reduced
2116 }
2117 }
2118 }
2120 //=============================================================================
2121 void Node_Stack::grow() {
2122 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2123 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2124 size_t max = old_max << 1; // max * 2
2125 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2126 _inode_max = _inodes + max;
2127 _inode_top = _inodes + old_top; // restore _top
2128 }
2130 // Node_Stack is used to map nodes.
2131 Node* Node_Stack::find(uint idx) const {
2132 uint sz = size();
2133 for (uint i=0; i < sz; i++) {
2134 if (idx == index_at(i) )
2135 return node_at(i);
2136 }
2137 return NULL;
2138 }
2140 //=============================================================================
2141 uint TypeNode::size_of() const { return sizeof(*this); }
2142 #ifndef PRODUCT
2143 void TypeNode::dump_spec(outputStream *st) const {
2144 if( !Verbose && !WizardMode ) {
2145 // standard dump does this in Verbose and WizardMode
2146 st->print(" #"); _type->dump_on(st);
2147 }
2148 }
2149 #endif
2150 uint TypeNode::hash() const {
2151 return Node::hash() + _type->hash();
2152 }
2153 uint TypeNode::cmp( const Node &n ) const
2154 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2155 const Type *TypeNode::bottom_type() const { return _type; }
2156 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2158 //------------------------------ideal_reg--------------------------------------
2159 uint TypeNode::ideal_reg() const {
2160 return _type->ideal_reg();
2161 }