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