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 */
24
25 #include "precompiled.hpp"
26 #include "libadt/vectset.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "opto/cfgnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/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"
38
39 class RegMask;
40 // #include "phase.hpp"
41 class PhaseTransform;
42 class PhaseGVN;
43
44 // Arena we are currently building Nodes in
45 const uint Node::NotAMachineReg = 0xffff0000;
46
47 #ifndef PRODUCT
48 extern int nodes_created;
49 #endif
50
51 #ifdef ASSERT
52
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 }
83
84
85 // #ifdef ASSERT ...
86
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 }
95
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 }
100
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 }
114
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 }
131
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 }
136
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 }
141
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 }
150
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 }
157
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 }
174
175 void DUIterator::refresh() {
176 DUIterator_Common::sample(_node); // Re-fetch assertion data.
177 _refresh_tick |= 1; // Set the "was refreshed" flag.
178 }
179
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 }
190
191
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 }
200
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 }
206
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 }
225
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 }
237
238 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
239 assert(_outp == that._outp, "already assigned _outp");
240 DUIterator_Common::reset(that);
241 }
242
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 }
250
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 }
256
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 }
266
267 #endif //OPTO_DU_ITERATOR_ASSERT
268
269
270 #endif //ASSERT
271
272
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)
276
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
289 #ifdef __clang__
290 #pragma clang diagnostic push
291 #pragma GCC diagnostic ignored "-Wuninitialized"
292 #endif
293
294 // Out-of-line code from node constructors.
295 // Executed only when extra debug info. is being passed around.
296 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
297 C->set_node_notes_at(idx, nn);
298 }
299
300 // Shared initialization code.
301 inline int Node::Init(int req, Compile* C) {
302 assert(Compile::current() == C, "must use operator new(Compile*)");
303 int idx = C->next_unique();
304
305 // Allocate memory for the necessary number of edges.
306 if (req > 0) {
307 // Allocate space for _in array to have double alignment.
308 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
309 #ifdef ASSERT
310 _in[req-1] = this; // magic cookie for assertion check
311 #endif
312 }
313 // If there are default notes floating around, capture them:
314 Node_Notes* nn = C->default_node_notes();
315 if (nn != NULL) init_node_notes(C, idx, nn);
316
317 // Note: At this point, C is dead,
318 // and we begin to initialize the new Node.
319
320 _cnt = _max = req;
321 _outcnt = _outmax = 0;
322 _class_id = Class_Node;
323 _flags = 0;
324 _out = NO_OUT_ARRAY;
325 return idx;
326 }
327
328 //------------------------------Node-------------------------------------------
329 // Create a Node, with a given number of required edges.
330 Node::Node(uint req)
331 : _idx(IDX_INIT(req))
332 {
333 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
334 debug_only( verify_construction() );
335 NOT_PRODUCT(nodes_created++);
336 if (req == 0) {
337 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
338 _in = NULL;
339 } else {
340 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
341 Node** to = _in;
342 for(uint i = 0; i < req; i++) {
343 to[i] = NULL;
344 }
345 }
346 }
347
348 //------------------------------Node-------------------------------------------
349 Node::Node(Node *n0)
350 : _idx(IDX_INIT(1))
351 {
352 debug_only( verify_construction() );
353 NOT_PRODUCT(nodes_created++);
354 // Assert we allocated space for input array already
355 assert( _in[0] == this, "Must pass arg count to 'new'" );
356 assert( is_not_dead(n0), "can not use dead node");
357 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
358 }
359
360 //------------------------------Node-------------------------------------------
361 Node::Node(Node *n0, Node *n1)
362 : _idx(IDX_INIT(2))
363 {
364 debug_only( verify_construction() );
365 NOT_PRODUCT(nodes_created++);
366 // Assert we allocated space for input array already
367 assert( _in[1] == this, "Must pass arg count to 'new'" );
368 assert( is_not_dead(n0), "can not use dead node");
369 assert( is_not_dead(n1), "can not use dead node");
370 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
371 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
372 }
373
374 //------------------------------Node-------------------------------------------
375 Node::Node(Node *n0, Node *n1, Node *n2)
376 : _idx(IDX_INIT(3))
377 {
378 debug_only( verify_construction() );
379 NOT_PRODUCT(nodes_created++);
380 // Assert we allocated space for input array already
381 assert( _in[2] == this, "Must pass arg count to 'new'" );
382 assert( is_not_dead(n0), "can not use dead node");
383 assert( is_not_dead(n1), "can not use dead node");
384 assert( is_not_dead(n2), "can not use dead node");
385 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
386 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
387 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
388 }
389
390 //------------------------------Node-------------------------------------------
391 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
392 : _idx(IDX_INIT(4))
393 {
394 debug_only( verify_construction() );
395 NOT_PRODUCT(nodes_created++);
396 // Assert we allocated space for input array already
397 assert( _in[3] == this, "Must pass arg count to 'new'" );
398 assert( is_not_dead(n0), "can not use dead node");
399 assert( is_not_dead(n1), "can not use dead node");
400 assert( is_not_dead(n2), "can not use dead node");
401 assert( is_not_dead(n3), "can not use dead node");
402 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
403 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
404 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
405 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
406 }
407
408 //------------------------------Node-------------------------------------------
409 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
410 : _idx(IDX_INIT(5))
411 {
412 debug_only( verify_construction() );
413 NOT_PRODUCT(nodes_created++);
414 // Assert we allocated space for input array already
415 assert( _in[4] == this, "Must pass arg count to 'new'" );
416 assert( is_not_dead(n0), "can not use dead node");
417 assert( is_not_dead(n1), "can not use dead node");
418 assert( is_not_dead(n2), "can not use dead node");
419 assert( is_not_dead(n3), "can not use dead node");
420 assert( is_not_dead(n4), "can not use dead node");
421 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
422 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
423 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
424 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
425 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
426 }
427
428 //------------------------------Node-------------------------------------------
429 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
430 Node *n4, Node *n5)
431 : _idx(IDX_INIT(6))
432 {
433 debug_only( verify_construction() );
434 NOT_PRODUCT(nodes_created++);
435 // Assert we allocated space for input array already
436 assert( _in[5] == this, "Must pass arg count to 'new'" );
437 assert( is_not_dead(n0), "can not use dead node");
438 assert( is_not_dead(n1), "can not use dead node");
439 assert( is_not_dead(n2), "can not use dead node");
440 assert( is_not_dead(n3), "can not use dead node");
441 assert( is_not_dead(n4), "can not use dead node");
442 assert( is_not_dead(n5), "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 }
450
451 //------------------------------Node-------------------------------------------
452 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
453 Node *n4, Node *n5, Node *n6)
454 : _idx(IDX_INIT(7))
455 {
456 debug_only( verify_construction() );
457 NOT_PRODUCT(nodes_created++);
458 // Assert we allocated space for input array already
459 assert( _in[6] == this, "Must pass arg count to 'new'" );
460 assert( is_not_dead(n0), "can not use dead node");
461 assert( is_not_dead(n1), "can not use dead node");
462 assert( is_not_dead(n2), "can not use dead node");
463 assert( is_not_dead(n3), "can not use dead node");
464 assert( is_not_dead(n4), "can not use dead node");
465 assert( is_not_dead(n5), "can not use dead node");
466 assert( is_not_dead(n6), "can not use dead node");
467 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
468 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
469 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
470 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
471 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
472 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
473 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
474 }
475
476 #ifdef __clang__
477 #pragma clang diagnostic pop
478 #endif
479
480
481 //------------------------------clone------------------------------------------
482 // Clone a Node.
483 Node *Node::clone() const {
484 Compile* C = Compile::current();
485 uint s = size_of(); // Size of inherited Node
486 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
487 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
488 // Set the new input pointer array
489 n->_in = (Node**)(((char*)n)+s);
490 // Cannot share the old output pointer array, so kill it
491 n->_out = NO_OUT_ARRAY;
492 // And reset the counters to 0
493 n->_outcnt = 0;
494 n->_outmax = 0;
495 // Unlock this guy, since he is not in any hash table.
496 debug_only(n->_hash_lock = 0);
497 // Walk the old node's input list to duplicate its edges
498 uint i;
499 for( i = 0; i < len(); i++ ) {
500 Node *x = in(i);
501 n->_in[i] = x;
502 if (x != NULL) x->add_out(n);
503 }
504 if (is_macro())
505 C->add_macro_node(n);
506 if (is_expensive())
507 C->add_expensive_node(n);
508
509 n->set_idx(C->next_unique()); // Get new unique index as well
510 debug_only( n->verify_construction() );
511 NOT_PRODUCT(nodes_created++);
512 // Do not patch over the debug_idx of a clone, because it makes it
513 // impossible to break on the clone's moment of creation.
514 //debug_only( n->set_debug_idx( debug_idx() ) );
515
516 C->copy_node_notes_to(n, (Node*) this);
517
518 // MachNode clone
519 uint nopnds;
520 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
521 MachNode *mach = n->as_Mach();
522 MachNode *mthis = this->as_Mach();
523 // Get address of _opnd_array.
524 // It should be the same offset since it is the clone of this node.
525 MachOper **from = mthis->_opnds;
526 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
527 pointer_delta((const void*)from,
528 (const void*)(&mthis->_opnds), 1));
529 mach->_opnds = to;
530 for ( uint i = 0; i < nopnds; ++i ) {
531 to[i] = from[i]->clone(C);
532 }
533 }
534 // cloning CallNode may need to clone JVMState
535 if (n->is_Call()) {
536 n->as_Call()->clone_jvms(C);
537 }
538 if (n->is_SafePoint()) {
539 n->as_SafePoint()->clone_replaced_nodes();
540 }
541 return n; // Return the clone
542 }
543
544 //---------------------------setup_is_top--------------------------------------
545 // Call this when changing the top node, to reassert the invariants
546 // required by Node::is_top. See Compile::set_cached_top_node.
547 void Node::setup_is_top() {
548 if (this == (Node*)Compile::current()->top()) {
549 // This node has just become top. Kill its out array.
550 _outcnt = _outmax = 0;
551 _out = NULL; // marker value for top
552 assert(is_top(), "must be top");
553 } else {
554 if (_out == NULL) _out = NO_OUT_ARRAY;
555 assert(!is_top(), "must not be top");
556 }
557 }
558
559
560 //------------------------------~Node------------------------------------------
561 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
562 extern int reclaim_idx ;
563 extern int reclaim_in ;
564 extern int reclaim_node;
565 void Node::destruct() {
566 // Eagerly reclaim unique Node numberings
567 Compile* compile = Compile::current();
568 if ((uint)_idx+1 == compile->unique()) {
569 compile->set_unique(compile->unique()-1);
570 #ifdef ASSERT
571 reclaim_idx++;
572 #endif
573 }
574 // Clear debug info:
575 Node_Notes* nn = compile->node_notes_at(_idx);
576 if (nn != NULL) nn->clear();
577 // Walk the input array, freeing the corresponding output edges
578 _cnt = _max; // forget req/prec distinction
579 uint i;
580 for( i = 0; i < _max; i++ ) {
581 set_req(i, NULL);
582 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
583 }
584 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
585 // See if the input array was allocated just prior to the object
586 int edge_size = _max*sizeof(void*);
587 int out_edge_size = _outmax*sizeof(void*);
588 char *edge_end = ((char*)_in) + edge_size;
589 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
590 char *out_edge_end = out_array + out_edge_size;
591 int node_size = size_of();
592
593 // Free the output edge array
594 if (out_edge_size > 0) {
595 #ifdef ASSERT
596 if( out_edge_end == compile->node_arena()->hwm() )
597 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
598 #endif
599 compile->node_arena()->Afree(out_array, out_edge_size);
600 }
601
602 // Free the input edge array and the node itself
603 if( edge_end == (char*)this ) {
604 #ifdef ASSERT
605 if( edge_end+node_size == compile->node_arena()->hwm() ) {
606 reclaim_in += edge_size;
607 reclaim_node+= node_size;
608 }
609 #else
610 // It was; free the input array and object all in one hit
611 compile->node_arena()->Afree(_in,edge_size+node_size);
612 #endif
613 } else {
614
615 // Free just the input array
616 #ifdef ASSERT
617 if( edge_end == compile->node_arena()->hwm() )
618 reclaim_in += edge_size;
619 #endif
620 compile->node_arena()->Afree(_in,edge_size);
621
622 // Free just the object
623 #ifdef ASSERT
624 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
625 reclaim_node+= node_size;
626 #else
627 compile->node_arena()->Afree(this,node_size);
628 #endif
629 }
630 if (is_macro()) {
631 compile->remove_macro_node(this);
632 }
633 if (is_expensive()) {
634 compile->remove_expensive_node(this);
635 }
636 #ifdef ASSERT
637 // We will not actually delete the storage, but we'll make the node unusable.
638 *(address*)this = badAddress; // smash the C++ vtbl, probably
639 _in = _out = (Node**) badAddress;
640 _max = _cnt = _outmax = _outcnt = 0;
641 #endif
642 }
643
644 //------------------------------grow-------------------------------------------
645 // Grow the input array, making space for more edges
646 void Node::grow( uint len ) {
647 Arena* arena = Compile::current()->node_arena();
648 uint new_max = _max;
649 if( new_max == 0 ) {
650 _max = 4;
651 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
652 Node** to = _in;
653 to[0] = NULL;
654 to[1] = NULL;
655 to[2] = NULL;
656 to[3] = NULL;
657 return;
658 }
659 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
660 // Trimming to limit allows a uint8 to handle up to 255 edges.
661 // Previously I was using only powers-of-2 which peaked at 128 edges.
662 //if( new_max >= limit ) new_max = limit-1;
663 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
664 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
665 _max = new_max; // Record new max length
666 // This assertion makes sure that Node::_max is wide enough to
667 // represent the numerical value of new_max.
668 assert(_max == new_max && _max > len, "int width of _max is too small");
669 }
670
671 //-----------------------------out_grow----------------------------------------
672 // Grow the input array, making space for more edges
673 void Node::out_grow( uint len ) {
674 assert(!is_top(), "cannot grow a top node's out array");
675 Arena* arena = Compile::current()->node_arena();
676 uint new_max = _outmax;
677 if( new_max == 0 ) {
678 _outmax = 4;
679 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
680 return;
681 }
682 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
683 // Trimming to limit allows a uint8 to handle up to 255 edges.
684 // Previously I was using only powers-of-2 which peaked at 128 edges.
685 //if( new_max >= limit ) new_max = limit-1;
686 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
687 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
688 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
689 _outmax = new_max; // Record new max length
690 // This assertion makes sure that Node::_max is wide enough to
691 // represent the numerical value of new_max.
692 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
693 }
694
695 #ifdef ASSERT
696 //------------------------------is_dead----------------------------------------
697 bool Node::is_dead() const {
698 // Mach and pinch point nodes may look like dead.
699 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
700 return false;
701 for( uint i = 0; i < _max; i++ )
702 if( _in[i] != NULL )
703 return false;
704 dump();
705 return true;
706 }
707 #endif
708
709
710 //------------------------------is_unreachable---------------------------------
711 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
712 assert(!is_Mach(), "doesn't work with MachNodes");
713 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
714 }
715
716 //------------------------------add_req----------------------------------------
717 // Add a new required input at the end
718 void Node::add_req( Node *n ) {
719 assert( is_not_dead(n), "can not use dead node");
720
721 // Look to see if I can move precedence down one without reallocating
722 if( (_cnt >= _max) || (in(_max-1) != NULL) )
723 grow( _max+1 );
724
725 // Find a precedence edge to move
726 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
727 uint i;
728 for( i=_cnt; i<_max; i++ )
729 if( in(i) == NULL ) // Find the NULL at end of prec edge list
730 break; // There must be one, since we grew the array
731 _in[i] = in(_cnt); // Move prec over, making space for req edge
732 }
733 _in[_cnt++] = n; // Stuff over old prec edge
734 if (n != NULL) n->add_out((Node *)this);
735 }
736
737 //---------------------------add_req_batch-------------------------------------
738 // Add a new required input at the end
739 void Node::add_req_batch( Node *n, uint m ) {
740 assert( is_not_dead(n), "can not use dead node");
741 // check various edge cases
742 if ((int)m <= 1) {
743 assert((int)m >= 0, "oob");
744 if (m != 0) add_req(n);
745 return;
746 }
747
748 // Look to see if I can move precedence down one without reallocating
749 if( (_cnt+m) > _max || _in[_max-m] )
750 grow( _max+m );
751
752 // Find a precedence edge to move
753 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
754 uint i;
755 for( i=_cnt; i<_max; i++ )
756 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
757 break; // There must be one, since we grew the array
758 // Slide all the precs over by m positions (assume #prec << m).
759 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
760 }
761
762 // Stuff over the old prec edges
763 for(uint i=0; i<m; i++ ) {
764 _in[_cnt++] = n;
765 }
766
767 // Insert multiple out edges on the node.
768 if (n != NULL && !n->is_top()) {
769 for(uint i=0; i<m; i++ ) {
770 n->add_out((Node *)this);
771 }
772 }
773 }
774
775 //------------------------------del_req----------------------------------------
776 // Delete the required edge and compact the edge array
777 void Node::del_req( uint idx ) {
778 assert( idx < _cnt, "oob");
779 assert( !VerifyHashTableKeys || _hash_lock == 0,
780 "remove node from hash table before modifying it");
781 // First remove corresponding def-use edge
782 Node *n = in(idx);
783 if (n != NULL) n->del_out((Node *)this);
784 _in[idx] = in(--_cnt); // Compact the array
785 _in[_cnt] = NULL; // NULL out emptied slot
786 }
787
788 //------------------------------del_req_ordered--------------------------------
789 // Delete the required edge and compact the edge array with preserved order
790 void Node::del_req_ordered( uint idx ) {
791 assert( idx < _cnt, "oob");
792 assert( !VerifyHashTableKeys || _hash_lock == 0,
793 "remove node from hash table before modifying it");
794 // First remove corresponding def-use edge
795 Node *n = in(idx);
796 if (n != NULL) n->del_out((Node *)this);
797 if (idx < _cnt - 1) { // Not last edge ?
798 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
799 }
800 _in[--_cnt] = NULL; // NULL out emptied slot
801 }
802
803 //------------------------------ins_req----------------------------------------
804 // Insert a new required input at the end
805 void Node::ins_req( uint idx, Node *n ) {
806 assert( is_not_dead(n), "can not use dead node");
807 add_req(NULL); // Make space
808 assert( idx < _max, "Must have allocated enough space");
809 // Slide over
810 if(_cnt-idx-1 > 0) {
811 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
812 }
813 _in[idx] = n; // Stuff over old required edge
814 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
815 }
816
817 //-----------------------------find_edge---------------------------------------
818 int Node::find_edge(Node* n) {
819 for (uint i = 0; i < len(); i++) {
820 if (_in[i] == n) return i;
821 }
822 return -1;
823 }
824
825 //----------------------------replace_edge-------------------------------------
826 int Node::replace_edge(Node* old, Node* neww) {
827 if (old == neww) return 0; // nothing to do
828 uint nrep = 0;
829 for (uint i = 0; i < len(); i++) {
830 if (in(i) == old) {
831 if (i < req())
832 set_req(i, neww);
833 else
834 set_prec(i, neww);
835 nrep++;
836 }
837 }
838 return nrep;
839 }
840
841 /**
842 * Replace input edges in the range pointing to 'old' node.
843 */
844 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
845 if (old == neww) return 0; // nothing to do
846 uint nrep = 0;
847 for (int i = start; i < end; i++) {
848 if (in(i) == old) {
849 set_req(i, neww);
850 nrep++;
851 }
852 }
853 return nrep;
854 }
855
856 //-------------------------disconnect_inputs-----------------------------------
857 // NULL out all inputs to eliminate incoming Def-Use edges.
858 // Return the number of edges between 'n' and 'this'
859 int Node::disconnect_inputs(Node *n, Compile* C) {
860 int edges_to_n = 0;
861
862 uint cnt = req();
863 for( uint i = 0; i < cnt; ++i ) {
864 if( in(i) == 0 ) continue;
865 if( in(i) == n ) ++edges_to_n;
866 set_req(i, NULL);
867 }
868 // Remove precedence edges if any exist
869 // Note: Safepoints may have precedence edges, even during parsing
870 if( (req() != len()) && (in(req()) != NULL) ) {
871 uint max = len();
872 for( uint i = 0; i < max; ++i ) {
873 if( in(i) == 0 ) continue;
874 if( in(i) == n ) ++edges_to_n;
875 set_prec(i, NULL);
876 }
877 }
878
879 // Node::destruct requires all out edges be deleted first
880 // debug_only(destruct();) // no reuse benefit expected
881 if (edges_to_n == 0) {
882 C->record_dead_node(_idx);
883 }
884 return edges_to_n;
885 }
886
887 //-----------------------------uncast---------------------------------------
888 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
889 // Strip away casting. (It is depth-limited.)
890 Node* Node::uncast() const {
891 // Should be inline:
892 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
893 if (is_ConstraintCast() || is_CheckCastPP())
894 return uncast_helper(this);
895 else
896 return (Node*) this;
897 }
898
899 //---------------------------uncast_helper-------------------------------------
900 Node* Node::uncast_helper(const Node* p) {
901 #ifdef ASSERT
902 uint depth_count = 0;
903 const Node* orig_p = p;
904 #endif
905
906 while (true) {
907 #ifdef ASSERT
908 if (depth_count >= K) {
909 orig_p->dump(4);
910 if (p != orig_p)
911 p->dump(1);
912 }
913 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
914 #endif
915 if (p == NULL || p->req() != 2) {
916 break;
917 } else if (p->is_ConstraintCast()) {
918 p = p->in(1);
919 } else if (p->is_CheckCastPP()) {
920 p = p->in(1);
921 } else {
922 break;
923 }
924 }
925 return (Node*) p;
926 }
927
928 //------------------------------add_prec---------------------------------------
929 // Add a new precedence input. Precedence inputs are unordered, with
930 // duplicates removed and NULLs packed down at the end.
931 void Node::add_prec( Node *n ) {
932 assert( is_not_dead(n), "can not use dead node");
933
934 // Check for NULL at end
935 if( _cnt >= _max || in(_max-1) )
936 grow( _max+1 );
937
938 // Find a precedence edge to move
939 uint i = _cnt;
940 while( in(i) != NULL ) i++;
941 _in[i] = n; // Stuff prec edge over NULL
942 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
943 }
944
945 //------------------------------rm_prec----------------------------------------
946 // Remove a precedence input. Precedence inputs are unordered, with
947 // duplicates removed and NULLs packed down at the end.
948 void Node::rm_prec( uint j ) {
949
950 // Find end of precedence list to pack NULLs
951 uint i;
952 for( i=j; i<_max; i++ )
953 if( !_in[i] ) // Find the NULL at end of prec edge list
954 break;
955 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
956 _in[j] = _in[--i]; // Move last element over removed guy
957 _in[i] = NULL; // NULL out last element
958 }
959
960 //------------------------------size_of----------------------------------------
961 uint Node::size_of() const { return sizeof(*this); }
962
963 //------------------------------ideal_reg--------------------------------------
964 uint Node::ideal_reg() const { return 0; }
965
966 //------------------------------jvms-------------------------------------------
967 JVMState* Node::jvms() const { return NULL; }
968
969 #ifdef ASSERT
970 //------------------------------jvms-------------------------------------------
971 bool Node::verify_jvms(const JVMState* using_jvms) const {
972 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
973 if (jvms == using_jvms) return true;
974 }
975 return false;
976 }
977
978 //------------------------------init_NodeProperty------------------------------
979 void Node::init_NodeProperty() {
980 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
981 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
982 }
983 #endif
984
985 //------------------------------format-----------------------------------------
986 // Print as assembly
987 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
988 //------------------------------emit-------------------------------------------
989 // Emit bytes starting at parameter 'ptr'.
990 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
991 //------------------------------size-------------------------------------------
992 // Size of instruction in bytes
993 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
994
995 //------------------------------CFG Construction-------------------------------
996 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
997 // Goto and Return.
998 const Node *Node::is_block_proj() const { return 0; }
999
1000 // Minimum guaranteed type
1001 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1002
1003
1004 //------------------------------raise_bottom_type------------------------------
1005 // Get the worst-case Type output for this Node.
1006 void Node::raise_bottom_type(const Type* new_type) {
1007 if (is_Type()) {
1008 TypeNode *n = this->as_Type();
1009 if (VerifyAliases) {
1010 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1011 }
1012 n->set_type(new_type);
1013 } else if (is_Load()) {
1014 LoadNode *n = this->as_Load();
1015 if (VerifyAliases) {
1016 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1017 }
1018 n->set_type(new_type);
1019 }
1020 }
1021
1022 //------------------------------Identity---------------------------------------
1023 // Return a node that the given node is equivalent to.
1024 Node *Node::Identity( PhaseTransform * ) {
1025 return this; // Default to no identities
1026 }
1027
1028 //------------------------------Value------------------------------------------
1029 // Compute a new Type for a node using the Type of the inputs.
1030 const Type *Node::Value( PhaseTransform * ) const {
1031 return bottom_type(); // Default to worst-case Type
1032 }
1033
1034 //------------------------------Ideal------------------------------------------
1035 //
1036 // 'Idealize' the graph rooted at this Node.
1037 //
1038 // In order to be efficient and flexible there are some subtle invariants
1039 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1040 // these invariants, although its too slow to have on by default. If you are
1041 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1042 //
1043 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1044 // pointer. If ANY change is made, it must return the root of the reshaped
1045 // graph - even if the root is the same Node. Example: swapping the inputs
1046 // to an AddINode gives the same answer and same root, but you still have to
1047 // return the 'this' pointer instead of NULL.
1048 //
1049 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1050 // Identity call to return an old Node; basically if Identity can find
1051 // another Node have the Ideal call make no change and return NULL.
1052 // Example: AddINode::Ideal must check for add of zero; in this case it
1053 // returns NULL instead of doing any graph reshaping.
1054 //
1055 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1056 // sharing there may be other users of the old Nodes relying on their current
1057 // semantics. Modifying them will break the other users.
1058 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1059 // "X+3" unchanged in case it is shared.
1060 //
1061 // If you modify the 'this' pointer's inputs, you should use
1062 // 'set_req'. If you are making a new Node (either as the new root or
1063 // some new internal piece) you may use 'init_req' to set the initial
1064 // value. You can make a new Node with either 'new' or 'clone'. In
1065 // either case, def-use info is correctly maintained.
1066 //
1067 // Example: reshape "(X+3)+4" into "X+7":
1068 // set_req(1, in(1)->in(1));
1069 // set_req(2, phase->intcon(7));
1070 // return this;
1071 // Example: reshape "X*4" into "X<<2"
1072 // return new (C) LShiftINode(in(1), phase->intcon(2));
1073 //
1074 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1075 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1076 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1077 // return new (C) AddINode(shift, in(1));
1078 //
1079 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1080 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1081 // The Right Thing with def-use info.
1082 //
1083 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1084 // graph uses the 'this' Node it must be the root. If you want a Node with
1085 // the same Opcode as the 'this' pointer use 'clone'.
1086 //
1087 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1088 return NULL; // Default to being Ideal already
1089 }
1090
1091 // Some nodes have specific Ideal subgraph transformations only if they are
1092 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1093 // for the transformations to happen.
1094 bool Node::has_special_unique_user() const {
1095 assert(outcnt() == 1, "match only for unique out");
1096 Node* n = unique_out();
1097 int op = Opcode();
1098 if( this->is_Store() ) {
1099 // Condition for back-to-back stores folding.
1100 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1101 } else if( op == Op_AddL ) {
1102 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1103 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1104 } else if( op == Op_SubI || op == Op_SubL ) {
1105 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1106 return n->Opcode() == op && n->in(2) == this;
1107 }
1108 return false;
1109 };
1110
1111 //--------------------------find_exact_control---------------------------------
1112 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1113 Node* Node::find_exact_control(Node* ctrl) {
1114 if (ctrl == NULL && this->is_Region())
1115 ctrl = this->as_Region()->is_copy();
1116
1117 if (ctrl != NULL && ctrl->is_CatchProj()) {
1118 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1119 ctrl = ctrl->in(0);
1120 if (ctrl != NULL && !ctrl->is_top())
1121 ctrl = ctrl->in(0);
1122 }
1123
1124 if (ctrl != NULL && ctrl->is_Proj())
1125 ctrl = ctrl->in(0);
1126
1127 return ctrl;
1128 }
1129
1130 //--------------------------dominates------------------------------------------
1131 // Helper function for MemNode::all_controls_dominate().
1132 // Check if 'this' control node dominates or equal to 'sub' control node.
1133 // We already know that if any path back to Root or Start reaches 'this',
1134 // then all paths so, so this is a simple search for one example,
1135 // not an exhaustive search for a counterexample.
1136 bool Node::dominates(Node* sub, Node_List &nlist) {
1137 assert(this->is_CFG(), "expecting control");
1138 assert(sub != NULL && sub->is_CFG(), "expecting control");
1139
1140 // detect dead cycle without regions
1141 int iterations_without_region_limit = DominatorSearchLimit;
1142
1143 Node* orig_sub = sub;
1144 Node* dom = this;
1145 bool met_dom = false;
1146 nlist.clear();
1147
1148 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1149 // After seeing 'dom', continue up to Root or Start.
1150 // If we hit a region (backward split point), it may be a loop head.
1151 // Keep going through one of the region's inputs. If we reach the
1152 // same region again, go through a different input. Eventually we
1153 // will either exit through the loop head, or give up.
1154 // (If we get confused, break out and return a conservative 'false'.)
1155 while (sub != NULL) {
1156 if (sub->is_top()) break; // Conservative answer for dead code.
1157 if (sub == dom) {
1158 if (nlist.size() == 0) {
1159 // No Region nodes except loops were visited before and the EntryControl
1160 // path was taken for loops: it did not walk in a cycle.
1161 return true;
1162 } else if (met_dom) {
1163 break; // already met before: walk in a cycle
1164 } else {
1165 // Region nodes were visited. Continue walk up to Start or Root
1166 // to make sure that it did not walk in a cycle.
1167 met_dom = true; // first time meet
1168 iterations_without_region_limit = DominatorSearchLimit; // Reset
1169 }
1170 }
1171 if (sub->is_Start() || sub->is_Root()) {
1172 // Success if we met 'dom' along a path to Start or Root.
1173 // We assume there are no alternative paths that avoid 'dom'.
1174 // (This assumption is up to the caller to ensure!)
1175 return met_dom;
1176 }
1177 Node* up = sub->in(0);
1178 // Normalize simple pass-through regions and projections:
1179 up = sub->find_exact_control(up);
1180 // If sub == up, we found a self-loop. Try to push past it.
1181 if (sub == up && sub->is_Loop()) {
1182 // Take loop entry path on the way up to 'dom'.
1183 up = sub->in(1); // in(LoopNode::EntryControl);
1184 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1185 // Always take in(1) path on the way up to 'dom' for clone regions
1186 // (with only one input) or regions which merge > 2 paths
1187 // (usually used to merge fast/slow paths).
1188 up = sub->in(1);
1189 } else if (sub == up && sub->is_Region()) {
1190 // Try both paths for Regions with 2 input paths (it may be a loop head).
1191 // It could give conservative 'false' answer without information
1192 // which region's input is the entry path.
1193 iterations_without_region_limit = DominatorSearchLimit; // Reset
1194
1195 bool region_was_visited_before = false;
1196 // Was this Region node visited before?
1197 // If so, we have reached it because we accidentally took a
1198 // loop-back edge from 'sub' back into the body of the loop,
1199 // and worked our way up again to the loop header 'sub'.
1200 // So, take the first unexplored path on the way up to 'dom'.
1201 for (int j = nlist.size() - 1; j >= 0; j--) {
1202 intptr_t ni = (intptr_t)nlist.at(j);
1203 Node* visited = (Node*)(ni & ~1);
1204 bool visited_twice_already = ((ni & 1) != 0);
1205 if (visited == sub) {
1206 if (visited_twice_already) {
1207 // Visited 2 paths, but still stuck in loop body. Give up.
1208 return false;
1209 }
1210 // The Region node was visited before only once.
1211 // (We will repush with the low bit set, below.)
1212 nlist.remove(j);
1213 // We will find a new edge and re-insert.
1214 region_was_visited_before = true;
1215 break;
1216 }
1217 }
1218
1219 // Find an incoming edge which has not been seen yet; walk through it.
1220 assert(up == sub, "");
1221 uint skip = region_was_visited_before ? 1 : 0;
1222 for (uint i = 1; i < sub->req(); i++) {
1223 Node* in = sub->in(i);
1224 if (in != NULL && !in->is_top() && in != sub) {
1225 if (skip == 0) {
1226 up = in;
1227 break;
1228 }
1229 --skip; // skip this nontrivial input
1230 }
1231 }
1232
1233 // Set 0 bit to indicate that both paths were taken.
1234 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1235 }
1236
1237 if (up == sub) {
1238 break; // some kind of tight cycle
1239 }
1240 if (up == orig_sub && met_dom) {
1241 // returned back after visiting 'dom'
1242 break; // some kind of cycle
1243 }
1244 if (--iterations_without_region_limit < 0) {
1245 break; // dead cycle
1246 }
1247 sub = up;
1248 }
1249
1250 // Did not meet Root or Start node in pred. chain.
1251 // Conservative answer for dead code.
1252 return false;
1253 }
1254
1255 //------------------------------remove_dead_region-----------------------------
1256 // This control node is dead. Follow the subgraph below it making everything
1257 // using it dead as well. This will happen normally via the usual IterGVN
1258 // worklist but this call is more efficient. Do not update use-def info
1259 // inside the dead region, just at the borders.
1260 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1261 // Con's are a popular node to re-hit in the hash table again.
1262 if( dead->is_Con() ) return;
1263
1264 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1265 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1266 Node_List nstack(Thread::current()->resource_area());
1267
1268 Node *top = igvn->C->top();
1269 nstack.push(dead);
1270 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1271
1272 while (nstack.size() > 0) {
1273 dead = nstack.pop();
1274 if (dead->outcnt() > 0) {
1275 // Keep dead node on stack until all uses are processed.
1276 nstack.push(dead);
1277 // For all Users of the Dead... ;-)
1278 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1279 Node* use = dead->last_out(k);
1280 igvn->hash_delete(use); // Yank from hash table prior to mod
1281 if (use->in(0) == dead) { // Found another dead node
1282 assert (!use->is_Con(), "Control for Con node should be Root node.");
1283 use->set_req(0, top); // Cut dead edge to prevent processing
1284 nstack.push(use); // the dead node again.
1285 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1286 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1287 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1288 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1289 use->set_req(0, top); // Cut self edge
1290 nstack.push(use);
1291 } else { // Else found a not-dead user
1292 // Dead if all inputs are top or null
1293 bool dead_use = !use->is_Root(); // Keep empty graph alive
1294 for (uint j = 1; j < use->req(); j++) {
1295 Node* in = use->in(j);
1296 if (in == dead) { // Turn all dead inputs into TOP
1297 use->set_req(j, top);
1298 } else if (in != NULL && !in->is_top()) {
1299 dead_use = false;
1300 }
1301 }
1302 if (dead_use) {
1303 if (use->is_Region()) {
1304 use->set_req(0, top); // Cut self edge
1305 }
1306 nstack.push(use);
1307 } else {
1308 igvn->_worklist.push(use);
1309 }
1310 }
1311 // Refresh the iterator, since any number of kills might have happened.
1312 k = dead->last_outs(kmin);
1313 }
1314 } else { // (dead->outcnt() == 0)
1315 // Done with outputs.
1316 igvn->hash_delete(dead);
1317 igvn->_worklist.remove(dead);
1318 igvn->set_type(dead, Type::TOP);
1319 if (dead->is_macro()) {
1320 igvn->C->remove_macro_node(dead);
1321 }
1322 if (dead->is_expensive()) {
1323 igvn->C->remove_expensive_node(dead);
1324 }
1325 igvn->C->record_dead_node(dead->_idx);
1326 // Kill all inputs to the dead guy
1327 for (uint i=0; i < dead->req(); i++) {
1328 Node *n = dead->in(i); // Get input to dead guy
1329 if (n != NULL && !n->is_top()) { // Input is valid?
1330 dead->set_req(i, top); // Smash input away
1331 if (n->outcnt() == 0) { // Input also goes dead?
1332 if (!n->is_Con())
1333 nstack.push(n); // Clear it out as well
1334 } else if (n->outcnt() == 1 &&
1335 n->has_special_unique_user()) {
1336 igvn->add_users_to_worklist( n );
1337 } else if (n->outcnt() <= 2 && n->is_Store()) {
1338 // Push store's uses on worklist to enable folding optimization for
1339 // store/store and store/load to the same address.
1340 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1341 // and remove_globally_dead_node().
1342 igvn->add_users_to_worklist( n );
1343 }
1344 }
1345 }
1346 } // (dead->outcnt() == 0)
1347 } // while (nstack.size() > 0) for outputs
1348 return;
1349 }
1350
1351 //------------------------------remove_dead_region-----------------------------
1352 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1353 Node *n = in(0);
1354 if( !n ) return false;
1355 // Lost control into this guy? I.e., it became unreachable?
1356 // Aggressively kill all unreachable code.
1357 if (can_reshape && n->is_top()) {
1358 kill_dead_code(this, phase->is_IterGVN());
1359 return false; // Node is dead.
1360 }
1361
1362 if( n->is_Region() && n->as_Region()->is_copy() ) {
1363 Node *m = n->nonnull_req();
1364 set_req(0, m);
1365 return true;
1366 }
1367 return false;
1368 }
1369
1370 //------------------------------Ideal_DU_postCCP-------------------------------
1371 // Idealize graph, using DU info. Must clone result into new-space
1372 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1373 return NULL; // Default to no change
1374 }
1375
1376 //------------------------------hash-------------------------------------------
1377 // Hash function over Nodes.
1378 uint Node::hash() const {
1379 uint sum = 0;
1380 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1381 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1382 return (sum>>2) + _cnt + Opcode();
1383 }
1384
1385 //------------------------------cmp--------------------------------------------
1386 // Compare special parts of simple Nodes
1387 uint Node::cmp( const Node &n ) const {
1388 return 1; // Must be same
1389 }
1390
1391 //------------------------------rematerialize-----------------------------------
1392 // Should we clone rather than spill this instruction?
1393 bool Node::rematerialize() const {
1394 if ( is_Mach() )
1395 return this->as_Mach()->rematerialize();
1396 else
1397 return (_flags & Flag_rematerialize) != 0;
1398 }
1399
1400 //------------------------------needs_anti_dependence_check---------------------
1401 // Nodes which use memory without consuming it, hence need antidependences.
1402 bool Node::needs_anti_dependence_check() const {
1403 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1404 return false;
1405 else
1406 return in(1)->bottom_type()->has_memory();
1407 }
1408
1409
1410 // Get an integer constant from a ConNode (or CastIINode).
1411 // Return a default value if there is no apparent constant here.
1412 const TypeInt* Node::find_int_type() const {
1413 if (this->is_Type()) {
1414 return this->as_Type()->type()->isa_int();
1415 } else if (this->is_Con()) {
1416 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1417 return this->bottom_type()->isa_int();
1418 }
1419 return NULL;
1420 }
1421
1422 // Get a pointer constant from a ConstNode.
1423 // Returns the constant if it is a pointer ConstNode
1424 intptr_t Node::get_ptr() const {
1425 assert( Opcode() == Op_ConP, "" );
1426 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1427 }
1428
1429 // Get a narrow oop constant from a ConNNode.
1430 intptr_t Node::get_narrowcon() const {
1431 assert( Opcode() == Op_ConN, "" );
1432 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1433 }
1434
1435 // Get a long constant from a ConNode.
1436 // Return a default value if there is no apparent constant here.
1437 const TypeLong* Node::find_long_type() const {
1438 if (this->is_Type()) {
1439 return this->as_Type()->type()->isa_long();
1440 } else if (this->is_Con()) {
1441 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1442 return this->bottom_type()->isa_long();
1443 }
1444 return NULL;
1445 }
1446
1447
1448 /**
1449 * Return a ptr type for nodes which should have it.
1450 */
1451 const TypePtr* Node::get_ptr_type() const {
1452 const TypePtr* tp = this->bottom_type()->make_ptr();
1453 #ifdef ASSERT
1454 if (tp == NULL) {
1455 this->dump(1);
1456 assert((tp != NULL), "unexpected node type");
1457 }
1458 #endif
1459 return tp;
1460 }
1461
1462 // Get a double constant from a ConstNode.
1463 // Returns the constant if it is a double ConstNode
1464 jdouble Node::getd() const {
1465 assert( Opcode() == Op_ConD, "" );
1466 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1467 }
1468
1469 // Get a float constant from a ConstNode.
1470 // Returns the constant if it is a float ConstNode
1471 jfloat Node::getf() const {
1472 assert( Opcode() == Op_ConF, "" );
1473 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1474 }
1475
1476 #ifndef PRODUCT
1477
1478 //----------------------------NotANode----------------------------------------
1479 // Used in debugging code to avoid walking across dead or uninitialized edges.
1480 static inline bool NotANode(const Node* n) {
1481 if (n == NULL) return true;
1482 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1483 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1484 return false;
1485 }
1486
1487
1488 //------------------------------find------------------------------------------
1489 // Find a neighbor of this Node with the given _idx
1490 // If idx is negative, find its absolute value, following both _in and _out.
1491 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1492 VectorSet* old_space, VectorSet* new_space ) {
1493 int node_idx = (idx >= 0) ? idx : -idx;
1494 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1495 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1496 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1497 if( v->test(n->_idx) ) return;
1498 if( (int)n->_idx == node_idx
1499 debug_only(|| n->debug_idx() == node_idx) ) {
1500 if (result != NULL)
1501 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1502 (uintptr_t)result, (uintptr_t)n, node_idx);
1503 result = n;
1504 }
1505 v->set(n->_idx);
1506 for( uint i=0; i<n->len(); i++ ) {
1507 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1508 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1509 }
1510 // Search along forward edges also:
1511 if (idx < 0 && !only_ctrl) {
1512 for( uint j=0; j<n->outcnt(); j++ ) {
1513 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1514 }
1515 }
1516 #ifdef ASSERT
1517 // Search along debug_orig edges last, checking for cycles
1518 Node* orig = n->debug_orig();
1519 if (orig != NULL) {
1520 do {
1521 if (NotANode(orig)) break;
1522 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1523 orig = orig->debug_orig();
1524 } while (orig != NULL && orig != n->debug_orig());
1525 }
1526 #endif //ASSERT
1527 }
1528
1529 // call this from debugger:
1530 Node* find_node(Node* n, int idx) {
1531 return n->find(idx);
1532 }
1533
1534 //------------------------------find-------------------------------------------
1535 Node* Node::find(int idx) const {
1536 ResourceArea *area = Thread::current()->resource_area();
1537 VectorSet old_space(area), new_space(area);
1538 Node* result = NULL;
1539 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1540 return result;
1541 }
1542
1543 //------------------------------find_ctrl--------------------------------------
1544 // Find an ancestor to this node in the control history with given _idx
1545 Node* Node::find_ctrl(int idx) const {
1546 ResourceArea *area = Thread::current()->resource_area();
1547 VectorSet old_space(area), new_space(area);
1548 Node* result = NULL;
1549 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1550 return result;
1551 }
1552 #endif
1553
1554
1555
1556 #ifndef PRODUCT
1557
1558 // -----------------------------Name-------------------------------------------
1559 extern const char *NodeClassNames[];
1560 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1561
1562 static bool is_disconnected(const Node* n) {
1563 for (uint i = 0; i < n->req(); i++) {
1564 if (n->in(i) != NULL) return false;
1565 }
1566 return true;
1567 }
1568
1569 #ifdef ASSERT
1570 static void dump_orig(Node* orig, outputStream *st) {
1571 Compile* C = Compile::current();
1572 if (NotANode(orig)) orig = NULL;
1573 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1574 if (orig == NULL) return;
1575 st->print(" !orig=");
1576 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1577 if (NotANode(fast)) fast = NULL;
1578 while (orig != NULL) {
1579 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1580 if (discon) st->print("[");
1581 if (!Compile::current()->node_arena()->contains(orig))
1582 st->print("o");
1583 st->print("%d", orig->_idx);
1584 if (discon) st->print("]");
1585 orig = orig->debug_orig();
1586 if (NotANode(orig)) orig = NULL;
1587 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1588 if (orig != NULL) st->print(",");
1589 if (fast != NULL) {
1590 // Step fast twice for each single step of orig:
1591 fast = fast->debug_orig();
1592 if (NotANode(fast)) fast = NULL;
1593 if (fast != NULL && fast != orig) {
1594 fast = fast->debug_orig();
1595 if (NotANode(fast)) fast = NULL;
1596 }
1597 if (fast == orig) {
1598 st->print("...");
1599 break;
1600 }
1601 }
1602 }
1603 }
1604
1605 void Node::set_debug_orig(Node* orig) {
1606 _debug_orig = orig;
1607 if (BreakAtNode == 0) return;
1608 if (NotANode(orig)) orig = NULL;
1609 int trip = 10;
1610 while (orig != NULL) {
1611 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1612 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1613 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1614 BREAKPOINT;
1615 }
1616 orig = orig->debug_orig();
1617 if (NotANode(orig)) orig = NULL;
1618 if (trip-- <= 0) break;
1619 }
1620 }
1621 #endif //ASSERT
1622
1623 //------------------------------dump------------------------------------------
1624 // Dump a Node
1625 void Node::dump(const char* suffix, outputStream *st) const {
1626 Compile* C = Compile::current();
1627 bool is_new = C->node_arena()->contains(this);
1628 C->_in_dump_cnt++;
1629 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1630
1631 // Dump the required and precedence inputs
1632 dump_req(st);
1633 dump_prec(st);
1634 // Dump the outputs
1635 dump_out(st);
1636
1637 if (is_disconnected(this)) {
1638 #ifdef ASSERT
1639 st->print(" [%d]",debug_idx());
1640 dump_orig(debug_orig(), st);
1641 #endif
1642 st->cr();
1643 C->_in_dump_cnt--;
1644 return; // don't process dead nodes
1645 }
1646
1647 // Dump node-specific info
1648 dump_spec(st);
1649 #ifdef ASSERT
1650 // Dump the non-reset _debug_idx
1651 if (Verbose && WizardMode) {
1652 st->print(" [%d]",debug_idx());
1653 }
1654 #endif
1655
1656 const Type *t = bottom_type();
1657
1658 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1659 const TypeInstPtr *toop = t->isa_instptr();
1660 const TypeKlassPtr *tkls = t->isa_klassptr();
1661 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1662 if (klass && klass->is_loaded() && klass->is_interface()) {
1663 st->print(" Interface:");
1664 } else if (toop) {
1665 st->print(" Oop:");
1666 } else if (tkls) {
1667 st->print(" Klass:");
1668 }
1669 t->dump_on(st);
1670 } else if (t == Type::MEMORY) {
1671 st->print(" Memory:");
1672 MemNode::dump_adr_type(this, adr_type(), st);
1673 } else if (Verbose || WizardMode) {
1674 st->print(" Type:");
1675 if (t) {
1676 t->dump_on(st);
1677 } else {
1678 st->print("no type");
1679 }
1680 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1681 // Dump MachSpillcopy vector type.
1682 t->dump_on(st);
1683 }
1684 if (is_new) {
1685 debug_only(dump_orig(debug_orig(), st));
1686 Node_Notes* nn = C->node_notes_at(_idx);
1687 if (nn != NULL && !nn->is_clear()) {
1688 if (nn->jvms() != NULL) {
1689 st->print(" !jvms:");
1690 nn->jvms()->dump_spec(st);
1691 }
1692 }
1693 }
1694 if (suffix) st->print("%s", suffix);
1695 C->_in_dump_cnt--;
1696 }
1697
1698 //------------------------------dump_req--------------------------------------
1699 void Node::dump_req(outputStream *st) const {
1700 // Dump the required input edges
1701 for (uint i = 0; i < req(); i++) { // For all required inputs
1702 Node* d = in(i);
1703 if (d == NULL) {
1704 st->print("_ ");
1705 } else if (NotANode(d)) {
1706 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1707 } else {
1708 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1709 }
1710 }
1711 }
1712
1713
1714 //------------------------------dump_prec-------------------------------------
1715 void Node::dump_prec(outputStream *st) const {
1716 // Dump the precedence edges
1717 int any_prec = 0;
1718 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1719 Node* p = in(i);
1720 if (p != NULL) {
1721 if (!any_prec++) st->print(" |");
1722 if (NotANode(p)) { st->print("NotANode "); continue; }
1723 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1724 }
1725 }
1726 }
1727
1728 //------------------------------dump_out--------------------------------------
1729 void Node::dump_out(outputStream *st) const {
1730 // Delimit the output edges
1731 st->print(" [[");
1732 // Dump the output edges
1733 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1734 Node* u = _out[i];
1735 if (u == NULL) {
1736 st->print("_ ");
1737 } else if (NotANode(u)) {
1738 st->print("NotANode ");
1739 } else {
1740 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1741 }
1742 }
1743 st->print("]] ");
1744 }
1745
1746 //------------------------------dump_nodes-------------------------------------
1747 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1748 Node* s = (Node*)start; // remove const
1749 if (NotANode(s)) return;
1750
1751 uint depth = (uint)ABS(d);
1752 int direction = d;
1753 Compile* C = Compile::current();
1754 GrowableArray <Node *> nstack(C->unique());
1755
1756 nstack.append(s);
1757 int begin = 0;
1758 int end = 0;
1759 for(uint i = 0; i < depth; i++) {
1760 end = nstack.length();
1761 for(int j = begin; j < end; j++) {
1762 Node* tp = nstack.at(j);
1763 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1764 for(uint k = 0; k < limit; k++) {
1765 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1766
1767 if (NotANode(n)) continue;
1768 // do not recurse through top or the root (would reach unrelated stuff)
1769 if (n->is_Root() || n->is_top()) continue;
1770 if (only_ctrl && !n->is_CFG()) continue;
1771
1772 bool on_stack = nstack.contains(n);
1773 if (!on_stack) {
1774 nstack.append(n);
1775 }
1776 }
1777 }
1778 begin = end;
1779 }
1780 end = nstack.length();
1781 if (direction > 0) {
1782 for(int j = end-1; j >= 0; j--) {
1783 nstack.at(j)->dump();
1784 }
1785 } else {
1786 for(int j = 0; j < end; j++) {
1787 nstack.at(j)->dump();
1788 }
1789 }
1790 }
1791
1792 //------------------------------dump-------------------------------------------
1793 void Node::dump(int d) const {
1794 dump_nodes(this, d, false);
1795 }
1796
1797 //------------------------------dump_ctrl--------------------------------------
1798 // Dump a Node's control history to depth
1799 void Node::dump_ctrl(int d) const {
1800 dump_nodes(this, d, true);
1801 }
1802
1803 // VERIFICATION CODE
1804 // For each input edge to a node (ie - for each Use-Def edge), verify that
1805 // there is a corresponding Def-Use edge.
1806 //------------------------------verify_edges-----------------------------------
1807 void Node::verify_edges(Unique_Node_List &visited) {
1808 uint i, j, idx;
1809 int cnt;
1810 Node *n;
1811
1812 // Recursive termination test
1813 if (visited.member(this)) return;
1814 visited.push(this);
1815
1816 // Walk over all input edges, checking for correspondence
1817 for( i = 0; i < len(); i++ ) {
1818 n = in(i);
1819 if (n != NULL && !n->is_top()) {
1820 // Count instances of (Node *)this
1821 cnt = 0;
1822 for (idx = 0; idx < n->_outcnt; idx++ ) {
1823 if (n->_out[idx] == (Node *)this) cnt++;
1824 }
1825 assert( cnt > 0,"Failed to find Def-Use edge." );
1826 // Check for duplicate edges
1827 // walk the input array downcounting the input edges to n
1828 for( j = 0; j < len(); j++ ) {
1829 if( in(j) == n ) cnt--;
1830 }
1831 assert( cnt == 0,"Mismatched edge count.");
1832 } else if (n == NULL) {
1833 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1834 } else {
1835 assert(n->is_top(), "sanity");
1836 // Nothing to check.
1837 }
1838 }
1839 // Recursive walk over all input edges
1840 for( i = 0; i < len(); i++ ) {
1841 n = in(i);
1842 if( n != NULL )
1843 in(i)->verify_edges(visited);
1844 }
1845 }
1846
1847 //------------------------------verify_recur-----------------------------------
1848 static const Node *unique_top = NULL;
1849
1850 void Node::verify_recur(const Node *n, int verify_depth,
1851 VectorSet &old_space, VectorSet &new_space) {
1852 if ( verify_depth == 0 ) return;
1853 if (verify_depth > 0) --verify_depth;
1854
1855 Compile* C = Compile::current();
1856
1857 // Contained in new_space or old_space?
1858 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1859 // Check for visited in the proper space. Numberings are not unique
1860 // across spaces so we need a separate VectorSet for each space.
1861 if( v->test_set(n->_idx) ) return;
1862
1863 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1864 if (C->cached_top_node() == NULL)
1865 C->set_cached_top_node((Node*)n);
1866 assert(C->cached_top_node() == n, "TOP node must be unique");
1867 }
1868
1869 for( uint i = 0; i < n->len(); i++ ) {
1870 Node *x = n->in(i);
1871 if (!x || x->is_top()) continue;
1872
1873 // Verify my input has a def-use edge to me
1874 if (true /*VerifyDefUse*/) {
1875 // Count use-def edges from n to x
1876 int cnt = 0;
1877 for( uint j = 0; j < n->len(); j++ )
1878 if( n->in(j) == x )
1879 cnt++;
1880 // Count def-use edges from x to n
1881 uint max = x->_outcnt;
1882 for( uint k = 0; k < max; k++ )
1883 if (x->_out[k] == n)
1884 cnt--;
1885 assert( cnt == 0, "mismatched def-use edge counts" );
1886 }
1887
1888 verify_recur(x, verify_depth, old_space, new_space);
1889 }
1890
1891 }
1892
1893 //------------------------------verify-----------------------------------------
1894 // Check Def-Use info for my subgraph
1895 void Node::verify() const {
1896 Compile* C = Compile::current();
1897 Node* old_top = C->cached_top_node();
1898 ResourceMark rm;
1899 ResourceArea *area = Thread::current()->resource_area();
1900 VectorSet old_space(area), new_space(area);
1901 verify_recur(this, -1, old_space, new_space);
1902 C->set_cached_top_node(old_top);
1903 }
1904 #endif
1905
1906
1907 //------------------------------walk-------------------------------------------
1908 // Graph walk, with both pre-order and post-order functions
1909 void Node::walk(NFunc pre, NFunc post, void *env) {
1910 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1911 walk_(pre, post, env, visited);
1912 }
1913
1914 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1915 if( visited.test_set(_idx) ) return;
1916 pre(*this,env); // Call the pre-order walk function
1917 for( uint i=0; i<_max; i++ )
1918 if( in(i) ) // Input exists and is not walked?
1919 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1920 post(*this,env); // Call the post-order walk function
1921 }
1922
1923 void Node::nop(Node &, void*) {}
1924
1925 //------------------------------Registers--------------------------------------
1926 // Do we Match on this edge index or not? Generally false for Control
1927 // and true for everything else. Weird for calls & returns.
1928 uint Node::match_edge(uint idx) const {
1929 return idx; // True for other than index 0 (control)
1930 }
1931
1932 static RegMask _not_used_at_all;
1933 // Register classes are defined for specific machines
1934 const RegMask &Node::out_RegMask() const {
1935 ShouldNotCallThis();
1936 return _not_used_at_all;
1937 }
1938
1939 const RegMask &Node::in_RegMask(uint) const {
1940 ShouldNotCallThis();
1941 return _not_used_at_all;
1942 }
1943
1944 //=============================================================================
1945 //-----------------------------------------------------------------------------
1946 void Node_Array::reset( Arena *new_arena ) {
1947 _a->Afree(_nodes,_max*sizeof(Node*));
1948 _max = 0;
1949 _nodes = NULL;
1950 _a = new_arena;
1951 }
1952
1953 //------------------------------clear------------------------------------------
1954 // Clear all entries in _nodes to NULL but keep storage
1955 void Node_Array::clear() {
1956 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1957 }
1958
1959 //-----------------------------------------------------------------------------
1960 void Node_Array::grow( uint i ) {
1961 if( !_max ) {
1962 _max = 1;
1963 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1964 _nodes[0] = NULL;
1965 }
1966 uint old = _max;
1967 while( i >= _max ) _max <<= 1; // Double to fit
1968 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1969 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1970 }
1971
1972 //-----------------------------------------------------------------------------
1973 void Node_Array::insert( uint i, Node *n ) {
1974 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1975 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1976 _nodes[i] = n;
1977 }
1978
1979 //-----------------------------------------------------------------------------
1980 void Node_Array::remove( uint i ) {
1981 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1982 _nodes[_max-1] = NULL;
1983 }
1984
1985 //-----------------------------------------------------------------------------
1986 void Node_Array::sort( C_sort_func_t func) {
1987 qsort( _nodes, _max, sizeof( Node* ), func );
1988 }
1989
1990 //-----------------------------------------------------------------------------
1991 void Node_Array::dump() const {
1992 #ifndef PRODUCT
1993 for( uint i = 0; i < _max; i++ ) {
1994 Node *nn = _nodes[i];
1995 if( nn != NULL ) {
1996 tty->print("%5d--> ",i); nn->dump();
1997 }
1998 }
1999 #endif
2000 }
2001
2002 //--------------------------is_iteratively_computed------------------------------
2003 // Operation appears to be iteratively computed (such as an induction variable)
2004 // It is possible for this operation to return false for a loop-varying
2005 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2006 bool Node::is_iteratively_computed() {
2007 if (ideal_reg()) { // does operation have a result register?
2008 for (uint i = 1; i < req(); i++) {
2009 Node* n = in(i);
2010 if (n != NULL && n->is_Phi()) {
2011 for (uint j = 1; j < n->req(); j++) {
2012 if (n->in(j) == this) {
2013 return true;
2014 }
2015 }
2016 }
2017 }
2018 }
2019 return false;
2020 }
2021
2022 //--------------------------find_similar------------------------------
2023 // Return a node with opcode "opc" and same inputs as "this" if one can
2024 // be found; Otherwise return NULL;
2025 Node* Node::find_similar(int opc) {
2026 if (req() >= 2) {
2027 Node* def = in(1);
2028 if (def && def->outcnt() >= 2) {
2029 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2030 Node* use = def->fast_out(i);
2031 if (use->Opcode() == opc &&
2032 use->req() == req()) {
2033 uint j;
2034 for (j = 0; j < use->req(); j++) {
2035 if (use->in(j) != in(j)) {
2036 break;
2037 }
2038 }
2039 if (j == use->req()) {
2040 return use;
2041 }
2042 }
2043 }
2044 }
2045 }
2046 return NULL;
2047 }
2048
2049
2050 //--------------------------unique_ctrl_out------------------------------
2051 // Return the unique control out if only one. Null if none or more than one.
2052 Node* Node::unique_ctrl_out() {
2053 Node* found = NULL;
2054 for (uint i = 0; i < outcnt(); i++) {
2055 Node* use = raw_out(i);
2056 if (use->is_CFG() && use != this) {
2057 if (found != NULL) return NULL;
2058 found = use;
2059 }
2060 }
2061 return found;
2062 }
2063
2064 //=============================================================================
2065 //------------------------------yank-------------------------------------------
2066 // Find and remove
2067 void Node_List::yank( Node *n ) {
2068 uint i;
2069 for( i = 0; i < _cnt; i++ )
2070 if( _nodes[i] == n )
2071 break;
2072
2073 if( i < _cnt )
2074 _nodes[i] = _nodes[--_cnt];
2075 }
2076
2077 //------------------------------dump-------------------------------------------
2078 void Node_List::dump() const {
2079 #ifndef PRODUCT
2080 for( uint i = 0; i < _cnt; i++ )
2081 if( _nodes[i] ) {
2082 tty->print("%5d--> ",i);
2083 _nodes[i]->dump();
2084 }
2085 #endif
2086 }
2087
2088 //=============================================================================
2089 //------------------------------remove-----------------------------------------
2090 void Unique_Node_List::remove( Node *n ) {
2091 if( _in_worklist[n->_idx] ) {
2092 for( uint i = 0; i < size(); i++ )
2093 if( _nodes[i] == n ) {
2094 map(i,Node_List::pop());
2095 _in_worklist >>= n->_idx;
2096 return;
2097 }
2098 ShouldNotReachHere();
2099 }
2100 }
2101
2102 //-----------------------remove_useless_nodes----------------------------------
2103 // Remove useless nodes from worklist
2104 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2105
2106 for( uint i = 0; i < size(); ++i ) {
2107 Node *n = at(i);
2108 assert( n != NULL, "Did not expect null entries in worklist");
2109 if( ! useful.test(n->_idx) ) {
2110 _in_worklist >>= n->_idx;
2111 map(i,Node_List::pop());
2112 // Node *replacement = Node_List::pop();
2113 // if( i != size() ) { // Check if removing last entry
2114 // _nodes[i] = replacement;
2115 // }
2116 --i; // Visit popped node
2117 // If it was last entry, loop terminates since size() was also reduced
2118 }
2119 }
2120 }
2121
2122 //=============================================================================
2123 void Node_Stack::grow() {
2124 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2125 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2126 size_t max = old_max << 1; // max * 2
2127 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2128 _inode_max = _inodes + max;
2129 _inode_top = _inodes + old_top; // restore _top
2130 }
2131
2132 // Node_Stack is used to map nodes.
2133 Node* Node_Stack::find(uint idx) const {
2134 uint sz = size();
2135 for (uint i=0; i < sz; i++) {
2136 if (idx == index_at(i) )
2137 return node_at(i);
2138 }
2139 return NULL;
2140 }
2141
2142 //=============================================================================
2143 uint TypeNode::size_of() const { return sizeof(*this); }
2144 #ifndef PRODUCT
2145 void TypeNode::dump_spec(outputStream *st) const {
2146 if( !Verbose && !WizardMode ) {
2147 // standard dump does this in Verbose and WizardMode
2148 st->print(" #"); _type->dump_on(st);
2149 }
2150 }
2151 #endif
2152 uint TypeNode::hash() const {
2153 return Node::hash() + _type->hash();
2154 }
2155 uint TypeNode::cmp( const Node &n ) const
2156 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2157 const Type *TypeNode::bottom_type() const { return _type; }
2158 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2159
2160 //------------------------------ideal_reg--------------------------------------
2161 uint TypeNode::ideal_reg() const {
2162 return _type->ideal_reg();
2163 }