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() < Compile::current()->max_node_limit(), "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
290 // Out-of-line code from node constructors.
291 // Executed only when extra debug info. is being passed around.
292 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
293 C->set_node_notes_at(idx, nn);
294 }
295
296 // Shared initialization code.
297 inline int Node::Init(int req, Compile* C) {
298 assert(Compile::current() == C, "must use operator new(Compile*)");
299 int idx = C->next_unique();
300
301 // Allocate memory for the necessary number of edges.
302 if (req > 0) {
303 // Allocate space for _in array to have double alignment.
304 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
305 #ifdef ASSERT
306 _in[req-1] = this; // magic cookie for assertion check
307 #endif
308 }
309 // If there are default notes floating around, capture them:
310 Node_Notes* nn = C->default_node_notes();
311 if (nn != NULL) init_node_notes(C, idx, nn);
312
313 // Note: At this point, C is dead,
314 // and we begin to initialize the new Node.
315
316 _cnt = _max = req;
317 _outcnt = _outmax = 0;
318 _class_id = Class_Node;
319 _flags = 0;
320 _out = NO_OUT_ARRAY;
321 return idx;
322 }
323
324 //------------------------------Node-------------------------------------------
325 // Create a Node, with a given number of required edges.
326 Node::Node(uint req)
327 : _idx(IDX_INIT(req))
328 #ifdef ASSERT
329 , _parse_idx(_idx)
330 #endif
331 {
332 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
333 debug_only( verify_construction() );
334 NOT_PRODUCT(nodes_created++);
335 if (req == 0) {
336 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
337 _in = NULL;
338 } else {
339 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
340 Node** to = _in;
341 for(uint i = 0; i < req; i++) {
342 to[i] = NULL;
343 }
344 }
345 }
346
347 //------------------------------Node-------------------------------------------
348 Node::Node(Node *n0)
349 : _idx(IDX_INIT(1))
350 #ifdef ASSERT
351 , _parse_idx(_idx)
352 #endif
353 {
354 debug_only( verify_construction() );
355 NOT_PRODUCT(nodes_created++);
356 // Assert we allocated space for input array already
357 assert( _in[0] == this, "Must pass arg count to 'new'" );
358 assert( is_not_dead(n0), "can not use dead node");
359 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
360 }
361
362 //------------------------------Node-------------------------------------------
363 Node::Node(Node *n0, Node *n1)
364 : _idx(IDX_INIT(2))
365 #ifdef ASSERT
366 , _parse_idx(_idx)
367 #endif
368 {
369 debug_only( verify_construction() );
370 NOT_PRODUCT(nodes_created++);
371 // Assert we allocated space for input array already
372 assert( _in[1] == this, "Must pass arg count to 'new'" );
373 assert( is_not_dead(n0), "can not use dead node");
374 assert( is_not_dead(n1), "can not use dead node");
375 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
376 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
377 }
378
379 //------------------------------Node-------------------------------------------
380 Node::Node(Node *n0, Node *n1, Node *n2)
381 : _idx(IDX_INIT(3))
382 #ifdef ASSERT
383 , _parse_idx(_idx)
384 #endif
385 {
386 debug_only( verify_construction() );
387 NOT_PRODUCT(nodes_created++);
388 // Assert we allocated space for input array already
389 assert( _in[2] == this, "Must pass arg count to 'new'" );
390 assert( is_not_dead(n0), "can not use dead node");
391 assert( is_not_dead(n1), "can not use dead node");
392 assert( is_not_dead(n2), "can not use dead node");
393 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
394 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
395 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
396 }
397
398 //------------------------------Node-------------------------------------------
399 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
400 : _idx(IDX_INIT(4))
401 #ifdef ASSERT
402 , _parse_idx(_idx)
403 #endif
404 {
405 debug_only( verify_construction() );
406 NOT_PRODUCT(nodes_created++);
407 // Assert we allocated space for input array already
408 assert( _in[3] == this, "Must pass arg count to 'new'" );
409 assert( is_not_dead(n0), "can not use dead node");
410 assert( is_not_dead(n1), "can not use dead node");
411 assert( is_not_dead(n2), "can not use dead node");
412 assert( is_not_dead(n3), "can not use dead node");
413 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
414 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
415 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
416 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
417 }
418
419 //------------------------------Node-------------------------------------------
420 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
421 : _idx(IDX_INIT(5))
422 #ifdef ASSERT
423 , _parse_idx(_idx)
424 #endif
425 {
426 debug_only( verify_construction() );
427 NOT_PRODUCT(nodes_created++);
428 // Assert we allocated space for input array already
429 assert( _in[4] == this, "Must pass arg count to 'new'" );
430 assert( is_not_dead(n0), "can not use dead node");
431 assert( is_not_dead(n1), "can not use dead node");
432 assert( is_not_dead(n2), "can not use dead node");
433 assert( is_not_dead(n3), "can not use dead node");
434 assert( is_not_dead(n4), "can not use dead node");
435 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
436 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
437 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
438 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
439 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
440 }
441
442 //------------------------------Node-------------------------------------------
443 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
444 Node *n4, Node *n5)
445 : _idx(IDX_INIT(6))
446 #ifdef ASSERT
447 , _parse_idx(_idx)
448 #endif
449 {
450 debug_only( verify_construction() );
451 NOT_PRODUCT(nodes_created++);
452 // Assert we allocated space for input array already
453 assert( _in[5] == this, "Must pass arg count to 'new'" );
454 assert( is_not_dead(n0), "can not use dead node");
455 assert( is_not_dead(n1), "can not use dead node");
456 assert( is_not_dead(n2), "can not use dead node");
457 assert( is_not_dead(n3), "can not use dead node");
458 assert( is_not_dead(n4), "can not use dead node");
459 assert( is_not_dead(n5), "can not use dead node");
460 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
461 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
462 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
463 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
464 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
465 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
466 }
467
468 //------------------------------Node-------------------------------------------
469 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
470 Node *n4, Node *n5, Node *n6)
471 : _idx(IDX_INIT(7))
472 #ifdef ASSERT
473 , _parse_idx(_idx)
474 #endif
475 {
476 debug_only( verify_construction() );
477 NOT_PRODUCT(nodes_created++);
478 // Assert we allocated space for input array already
479 assert( _in[6] == this, "Must pass arg count to 'new'" );
480 assert( is_not_dead(n0), "can not use dead node");
481 assert( is_not_dead(n1), "can not use dead node");
482 assert( is_not_dead(n2), "can not use dead node");
483 assert( is_not_dead(n3), "can not use dead node");
484 assert( is_not_dead(n4), "can not use dead node");
485 assert( is_not_dead(n5), "can not use dead node");
486 assert( is_not_dead(n6), "can not use dead node");
487 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
488 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
489 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
490 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
491 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
492 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
493 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
494 }
495
496
497 //------------------------------clone------------------------------------------
498 // Clone a Node.
499 Node *Node::clone() const {
500 Compile* C = Compile::current();
501 uint s = size_of(); // Size of inherited Node
502 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
503 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
504 // Set the new input pointer array
505 n->_in = (Node**)(((char*)n)+s);
506 // Cannot share the old output pointer array, so kill it
507 n->_out = NO_OUT_ARRAY;
508 // And reset the counters to 0
509 n->_outcnt = 0;
510 n->_outmax = 0;
511 // Unlock this guy, since he is not in any hash table.
512 debug_only(n->_hash_lock = 0);
513 // Walk the old node's input list to duplicate its edges
514 uint i;
515 for( i = 0; i < len(); i++ ) {
516 Node *x = in(i);
517 n->_in[i] = x;
518 if (x != NULL) x->add_out(n);
519 }
520 if (is_macro())
521 C->add_macro_node(n);
522 if (is_expensive())
523 C->add_expensive_node(n);
524 // If the cloned node is a range check dependent CastII, add it to the list.
525 CastIINode* cast = n->isa_CastII();
526 if (cast != NULL && cast->has_range_check()) {
527 C->add_range_check_cast(cast);
528 }
529
530 n->set_idx(C->next_unique()); // Get new unique index as well
531 debug_only( n->verify_construction() );
532 NOT_PRODUCT(nodes_created++);
533 // Do not patch over the debug_idx of a clone, because it makes it
534 // impossible to break on the clone's moment of creation.
535 //debug_only( n->set_debug_idx( debug_idx() ) );
536
537 C->copy_node_notes_to(n, (Node*) this);
538
539 // MachNode clone
540 uint nopnds;
541 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
542 MachNode *mach = n->as_Mach();
543 MachNode *mthis = this->as_Mach();
544 // Get address of _opnd_array.
545 // It should be the same offset since it is the clone of this node.
546 MachOper **from = mthis->_opnds;
547 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
548 pointer_delta((const void*)from,
549 (const void*)(&mthis->_opnds), 1));
550 mach->_opnds = to;
551 for ( uint i = 0; i < nopnds; ++i ) {
552 to[i] = from[i]->clone(C);
553 }
554 }
555 // cloning CallNode may need to clone JVMState
556 if (n->is_Call()) {
557 n->as_Call()->clone_jvms(C);
558 }
559 if (n->is_SafePoint()) {
560 n->as_SafePoint()->clone_replaced_nodes();
561 }
562 return n; // Return the clone
563 }
564
565 //---------------------------setup_is_top--------------------------------------
566 // Call this when changing the top node, to reassert the invariants
567 // required by Node::is_top. See Compile::set_cached_top_node.
568 void Node::setup_is_top() {
569 if (this == (Node*)Compile::current()->top()) {
570 // This node has just become top. Kill its out array.
571 _outcnt = _outmax = 0;
572 _out = NULL; // marker value for top
573 assert(is_top(), "must be top");
574 } else {
575 if (_out == NULL) _out = NO_OUT_ARRAY;
576 assert(!is_top(), "must not be top");
577 }
578 }
579
580
581 //------------------------------~Node------------------------------------------
582 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
583 extern int reclaim_idx ;
584 extern int reclaim_in ;
585 extern int reclaim_node;
586 void Node::destruct() {
587 // Eagerly reclaim unique Node numberings
588 Compile* compile = Compile::current();
589 if ((uint)_idx+1 == compile->unique()) {
590 compile->set_unique(compile->unique()-1);
591 #ifdef ASSERT
592 reclaim_idx++;
593 #endif
594 }
595 // Clear debug info:
596 Node_Notes* nn = compile->node_notes_at(_idx);
597 if (nn != NULL) nn->clear();
598 // Walk the input array, freeing the corresponding output edges
599 _cnt = _max; // forget req/prec distinction
600 uint i;
601 for( i = 0; i < _max; i++ ) {
602 set_req(i, NULL);
603 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
604 }
605 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
606 // See if the input array was allocated just prior to the object
607 int edge_size = _max*sizeof(void*);
608 int out_edge_size = _outmax*sizeof(void*);
609 char *edge_end = ((char*)_in) + edge_size;
610 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
611 char *out_edge_end = out_array + out_edge_size;
612 int node_size = size_of();
613
614 // Free the output edge array
615 if (out_edge_size > 0) {
616 #ifdef ASSERT
617 if( out_edge_end == compile->node_arena()->hwm() )
618 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
619 #endif
620 compile->node_arena()->Afree(out_array, out_edge_size);
621 }
622
623 // Free the input edge array and the node itself
624 if( edge_end == (char*)this ) {
625 #ifdef ASSERT
626 if( edge_end+node_size == compile->node_arena()->hwm() ) {
627 reclaim_in += edge_size;
628 reclaim_node+= node_size;
629 }
630 #else
631 // It was; free the input array and object all in one hit
632 compile->node_arena()->Afree(_in,edge_size+node_size);
633 #endif
634 } else {
635
636 // Free just the input array
637 #ifdef ASSERT
638 if( edge_end == compile->node_arena()->hwm() )
639 reclaim_in += edge_size;
640 #endif
641 compile->node_arena()->Afree(_in,edge_size);
642
643 // Free just the object
644 #ifdef ASSERT
645 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
646 reclaim_node+= node_size;
647 #else
648 compile->node_arena()->Afree(this,node_size);
649 #endif
650 }
651 if (is_macro()) {
652 compile->remove_macro_node(this);
653 }
654 if (is_expensive()) {
655 compile->remove_expensive_node(this);
656 }
657 CastIINode* cast = isa_CastII();
658 if (cast != NULL && cast->has_range_check()) {
659 compile->remove_range_check_cast(cast);
660 }
661
662 if (is_SafePoint()) {
663 as_SafePoint()->delete_replaced_nodes();
664 }
665 #ifdef ASSERT
666 // We will not actually delete the storage, but we'll make the node unusable.
667 *(address*)this = badAddress; // smash the C++ vtbl, probably
668 _in = _out = (Node**) badAddress;
669 _max = _cnt = _outmax = _outcnt = 0;
670 #endif
671 }
672
673 //------------------------------grow-------------------------------------------
674 // Grow the input array, making space for more edges
675 void Node::grow( uint len ) {
676 Arena* arena = Compile::current()->node_arena();
677 uint new_max = _max;
678 if( new_max == 0 ) {
679 _max = 4;
680 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
681 Node** to = _in;
682 to[0] = NULL;
683 to[1] = NULL;
684 to[2] = NULL;
685 to[3] = NULL;
686 return;
687 }
688 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
689 // Trimming to limit allows a uint8 to handle up to 255 edges.
690 // Previously I was using only powers-of-2 which peaked at 128 edges.
691 //if( new_max >= limit ) new_max = limit-1;
692 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
693 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
694 _max = new_max; // Record new max length
695 // This assertion makes sure that Node::_max is wide enough to
696 // represent the numerical value of new_max.
697 assert(_max == new_max && _max > len, "int width of _max is too small");
698 }
699
700 //-----------------------------out_grow----------------------------------------
701 // Grow the input array, making space for more edges
702 void Node::out_grow( uint len ) {
703 assert(!is_top(), "cannot grow a top node's out array");
704 Arena* arena = Compile::current()->node_arena();
705 uint new_max = _outmax;
706 if( new_max == 0 ) {
707 _outmax = 4;
708 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
709 return;
710 }
711 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
712 // Trimming to limit allows a uint8 to handle up to 255 edges.
713 // Previously I was using only powers-of-2 which peaked at 128 edges.
714 //if( new_max >= limit ) new_max = limit-1;
715 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
716 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
717 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
718 _outmax = new_max; // Record new max length
719 // This assertion makes sure that Node::_max is wide enough to
720 // represent the numerical value of new_max.
721 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
722 }
723
724 #ifdef ASSERT
725 //------------------------------is_dead----------------------------------------
726 bool Node::is_dead() const {
727 // Mach and pinch point nodes may look like dead.
728 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
729 return false;
730 for( uint i = 0; i < _max; i++ )
731 if( _in[i] != NULL )
732 return false;
733 dump();
734 return true;
735 }
736 #endif
737
738
739 //------------------------------is_unreachable---------------------------------
740 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
741 assert(!is_Mach(), "doesn't work with MachNodes");
742 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
743 }
744
745 //------------------------------add_req----------------------------------------
746 // Add a new required input at the end
747 void Node::add_req( Node *n ) {
748 assert( is_not_dead(n), "can not use dead node");
749
750 // Look to see if I can move precedence down one without reallocating
751 if( (_cnt >= _max) || (in(_max-1) != NULL) )
752 grow( _max+1 );
753
754 // Find a precedence edge to move
755 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
756 uint i;
757 for( i=_cnt; i<_max; i++ )
758 if( in(i) == NULL ) // Find the NULL at end of prec edge list
759 break; // There must be one, since we grew the array
760 _in[i] = in(_cnt); // Move prec over, making space for req edge
761 }
762 _in[_cnt++] = n; // Stuff over old prec edge
763 if (n != NULL) n->add_out((Node *)this);
764 }
765
766 //---------------------------add_req_batch-------------------------------------
767 // Add a new required input at the end
768 void Node::add_req_batch( Node *n, uint m ) {
769 assert( is_not_dead(n), "can not use dead node");
770 // check various edge cases
771 if ((int)m <= 1) {
772 assert((int)m >= 0, "oob");
773 if (m != 0) add_req(n);
774 return;
775 }
776
777 // Look to see if I can move precedence down one without reallocating
778 if( (_cnt+m) > _max || _in[_max-m] )
779 grow( _max+m );
780
781 // Find a precedence edge to move
782 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
783 uint i;
784 for( i=_cnt; i<_max; i++ )
785 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
786 break; // There must be one, since we grew the array
787 // Slide all the precs over by m positions (assume #prec << m).
788 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
789 }
790
791 // Stuff over the old prec edges
792 for(uint i=0; i<m; i++ ) {
793 _in[_cnt++] = n;
794 }
795
796 // Insert multiple out edges on the node.
797 if (n != NULL && !n->is_top()) {
798 for(uint i=0; i<m; i++ ) {
799 n->add_out((Node *)this);
800 }
801 }
802 }
803
804 //------------------------------del_req----------------------------------------
805 // Delete the required edge and compact the edge array
806 void Node::del_req( uint idx ) {
807 assert( idx < _cnt, "oob");
808 assert( !VerifyHashTableKeys || _hash_lock == 0,
809 "remove node from hash table before modifying it");
810 // First remove corresponding def-use edge
811 Node *n = in(idx);
812 if (n != NULL) n->del_out((Node *)this);
813 _in[idx] = in(--_cnt); // Compact the array
814 _in[_cnt] = NULL; // NULL out emptied slot
815 }
816
817 //------------------------------del_req_ordered--------------------------------
818 // Delete the required edge and compact the edge array with preserved order
819 void Node::del_req_ordered( uint idx ) {
820 assert( idx < _cnt, "oob");
821 assert( !VerifyHashTableKeys || _hash_lock == 0,
822 "remove node from hash table before modifying it");
823 // First remove corresponding def-use edge
824 Node *n = in(idx);
825 if (n != NULL) n->del_out((Node *)this);
826 if (idx < _cnt - 1) { // Not last edge ?
827 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
828 }
829 _in[--_cnt] = NULL; // NULL out emptied slot
830 }
831
832 //------------------------------ins_req----------------------------------------
833 // Insert a new required input at the end
834 void Node::ins_req( uint idx, Node *n ) {
835 assert( is_not_dead(n), "can not use dead node");
836 add_req(NULL); // Make space
837 assert( idx < _max, "Must have allocated enough space");
838 // Slide over
839 if(_cnt-idx-1 > 0) {
840 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
841 }
842 _in[idx] = n; // Stuff over old required edge
843 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
844 }
845
846 //-----------------------------find_edge---------------------------------------
847 int Node::find_edge(Node* n) {
848 for (uint i = 0; i < len(); i++) {
849 if (_in[i] == n) return i;
850 }
851 return -1;
852 }
853
854 //----------------------------replace_edge-------------------------------------
855 int Node::replace_edge(Node* old, Node* neww) {
856 if (old == neww) return 0; // nothing to do
857 uint nrep = 0;
858 for (uint i = 0; i < len(); i++) {
859 if (in(i) == old) {
860 if (i < req())
861 set_req(i, neww);
862 else
863 set_prec(i, neww);
864 nrep++;
865 }
866 }
867 return nrep;
868 }
869
870 /**
871 * Replace input edges in the range pointing to 'old' node.
872 */
873 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
874 if (old == neww) return 0; // nothing to do
875 uint nrep = 0;
876 for (int i = start; i < end; i++) {
877 if (in(i) == old) {
878 set_req(i, neww);
879 nrep++;
880 }
881 }
882 return nrep;
883 }
884
885 //-------------------------disconnect_inputs-----------------------------------
886 // NULL out all inputs to eliminate incoming Def-Use edges.
887 // Return the number of edges between 'n' and 'this'
888 int Node::disconnect_inputs(Node *n, Compile* C) {
889 int edges_to_n = 0;
890
891 uint cnt = req();
892 for( uint i = 0; i < cnt; ++i ) {
893 if( in(i) == 0 ) continue;
894 if( in(i) == n ) ++edges_to_n;
895 set_req(i, NULL);
896 }
897 // Remove precedence edges if any exist
898 // Note: Safepoints may have precedence edges, even during parsing
899 if( (req() != len()) && (in(req()) != NULL) ) {
900 uint max = len();
901 for( uint i = 0; i < max; ++i ) {
902 if( in(i) == 0 ) continue;
903 if( in(i) == n ) ++edges_to_n;
904 set_prec(i, NULL);
905 }
906 }
907
908 // Node::destruct requires all out edges be deleted first
909 // debug_only(destruct();) // no reuse benefit expected
910 if (edges_to_n == 0) {
911 C->record_dead_node(_idx);
912 }
913 return edges_to_n;
914 }
915
916 //-----------------------------uncast---------------------------------------
917 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
918 // Strip away casting. (It is depth-limited.)
919 Node* Node::uncast() const {
920 // Should be inline:
921 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
922 if (is_ConstraintCast() || is_CheckCastPP())
923 return uncast_helper(this);
924 else
925 return (Node*) this;
926 }
927
928 //---------------------------uncast_helper-------------------------------------
929 Node* Node::uncast_helper(const Node* p) {
930 #ifdef ASSERT
931 uint depth_count = 0;
932 const Node* orig_p = p;
933 #endif
934
935 while (true) {
936 #ifdef ASSERT
937 if (depth_count >= K) {
938 orig_p->dump(4);
939 if (p != orig_p)
940 p->dump(1);
941 }
942 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
943 #endif
944 if (p == NULL || p->req() != 2) {
945 break;
946 } else if (p->is_ConstraintCast()) {
947 p = p->in(1);
948 } else if (p->is_CheckCastPP()) {
949 p = p->in(1);
950 } else {
951 break;
952 }
953 }
954 return (Node*) p;
955 }
956
957 //------------------------------add_prec---------------------------------------
958 // Add a new precedence input. Precedence inputs are unordered, with
959 // duplicates removed and NULLs packed down at the end.
960 void Node::add_prec( Node *n ) {
961 assert( is_not_dead(n), "can not use dead node");
962
963 // Check for NULL at end
964 if( _cnt >= _max || in(_max-1) )
965 grow( _max+1 );
966
967 // Find a precedence edge to move
968 uint i = _cnt;
969 while( in(i) != NULL ) i++;
970 _in[i] = n; // Stuff prec edge over NULL
971 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
972 }
973
974 //------------------------------rm_prec----------------------------------------
975 // Remove a precedence input. Precedence inputs are unordered, with
976 // duplicates removed and NULLs packed down at the end.
977 void Node::rm_prec( uint j ) {
978
979 // Find end of precedence list to pack NULLs
980 uint i;
981 for( i=j; i<_max; i++ )
982 if( !_in[i] ) // Find the NULL at end of prec edge list
983 break;
984 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
985 _in[j] = _in[--i]; // Move last element over removed guy
986 _in[i] = NULL; // NULL out last element
987 }
988
989 //------------------------------size_of----------------------------------------
990 uint Node::size_of() const { return sizeof(*this); }
991
992 //------------------------------ideal_reg--------------------------------------
993 uint Node::ideal_reg() const { return 0; }
994
995 //------------------------------jvms-------------------------------------------
996 JVMState* Node::jvms() const { return NULL; }
997
998 #ifdef ASSERT
999 //------------------------------jvms-------------------------------------------
1000 bool Node::verify_jvms(const JVMState* using_jvms) const {
1001 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1002 if (jvms == using_jvms) return true;
1003 }
1004 return false;
1005 }
1006
1007 //------------------------------init_NodeProperty------------------------------
1008 void Node::init_NodeProperty() {
1009 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1010 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1011 }
1012 #endif
1013
1014 //------------------------------format-----------------------------------------
1015 // Print as assembly
1016 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1017 //------------------------------emit-------------------------------------------
1018 // Emit bytes starting at parameter 'ptr'.
1019 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1020 //------------------------------size-------------------------------------------
1021 // Size of instruction in bytes
1022 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1023
1024 //------------------------------CFG Construction-------------------------------
1025 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1026 // Goto and Return.
1027 const Node *Node::is_block_proj() const { return 0; }
1028
1029 // Minimum guaranteed type
1030 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1031
1032
1033 //------------------------------raise_bottom_type------------------------------
1034 // Get the worst-case Type output for this Node.
1035 void Node::raise_bottom_type(const Type* new_type) {
1036 if (is_Type()) {
1037 TypeNode *n = this->as_Type();
1038 if (VerifyAliases) {
1039 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1040 }
1041 n->set_type(new_type);
1042 } else if (is_Load()) {
1043 LoadNode *n = this->as_Load();
1044 if (VerifyAliases) {
1045 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1046 }
1047 n->set_type(new_type);
1048 }
1049 }
1050
1051 //------------------------------Identity---------------------------------------
1052 // Return a node that the given node is equivalent to.
1053 Node *Node::Identity( PhaseTransform * ) {
1054 return this; // Default to no identities
1055 }
1056
1057 //------------------------------Value------------------------------------------
1058 // Compute a new Type for a node using the Type of the inputs.
1059 const Type *Node::Value( PhaseTransform * ) const {
1060 return bottom_type(); // Default to worst-case Type
1061 }
1062
1063 //------------------------------Ideal------------------------------------------
1064 //
1065 // 'Idealize' the graph rooted at this Node.
1066 //
1067 // In order to be efficient and flexible there are some subtle invariants
1068 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1069 // these invariants, although its too slow to have on by default. If you are
1070 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1071 //
1072 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1073 // pointer. If ANY change is made, it must return the root of the reshaped
1074 // graph - even if the root is the same Node. Example: swapping the inputs
1075 // to an AddINode gives the same answer and same root, but you still have to
1076 // return the 'this' pointer instead of NULL.
1077 //
1078 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1079 // Identity call to return an old Node; basically if Identity can find
1080 // another Node have the Ideal call make no change and return NULL.
1081 // Example: AddINode::Ideal must check for add of zero; in this case it
1082 // returns NULL instead of doing any graph reshaping.
1083 //
1084 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1085 // sharing there may be other users of the old Nodes relying on their current
1086 // semantics. Modifying them will break the other users.
1087 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1088 // "X+3" unchanged in case it is shared.
1089 //
1090 // If you modify the 'this' pointer's inputs, you should use
1091 // 'set_req'. If you are making a new Node (either as the new root or
1092 // some new internal piece) you may use 'init_req' to set the initial
1093 // value. You can make a new Node with either 'new' or 'clone'. In
1094 // either case, def-use info is correctly maintained.
1095 //
1096 // Example: reshape "(X+3)+4" into "X+7":
1097 // set_req(1, in(1)->in(1));
1098 // set_req(2, phase->intcon(7));
1099 // return this;
1100 // Example: reshape "X*4" into "X<<2"
1101 // return new (C) LShiftINode(in(1), phase->intcon(2));
1102 //
1103 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1104 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1105 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1106 // return new (C) AddINode(shift, in(1));
1107 //
1108 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1109 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1110 // The Right Thing with def-use info.
1111 //
1112 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1113 // graph uses the 'this' Node it must be the root. If you want a Node with
1114 // the same Opcode as the 'this' pointer use 'clone'.
1115 //
1116 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1117 return NULL; // Default to being Ideal already
1118 }
1119
1120 // Some nodes have specific Ideal subgraph transformations only if they are
1121 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1122 // for the transformations to happen.
1123 bool Node::has_special_unique_user() const {
1124 assert(outcnt() == 1, "match only for unique out");
1125 Node* n = unique_out();
1126 int op = Opcode();
1127 if( this->is_Store() ) {
1128 // Condition for back-to-back stores folding.
1129 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1130 } else if (this->is_Load()) {
1131 // Condition for removing an unused LoadNode from the MemBarAcquire precedence input
1132 return n->Opcode() == Op_MemBarAcquire;
1133 } else if( op == Op_AddL ) {
1134 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1135 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1136 } else if( op == Op_SubI || op == Op_SubL ) {
1137 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1138 return n->Opcode() == op && n->in(2) == this;
1139 }
1140 return false;
1141 };
1142
1143 //--------------------------find_exact_control---------------------------------
1144 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1145 Node* Node::find_exact_control(Node* ctrl) {
1146 if (ctrl == NULL && this->is_Region())
1147 ctrl = this->as_Region()->is_copy();
1148
1149 if (ctrl != NULL && ctrl->is_CatchProj()) {
1150 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1151 ctrl = ctrl->in(0);
1152 if (ctrl != NULL && !ctrl->is_top())
1153 ctrl = ctrl->in(0);
1154 }
1155
1156 if (ctrl != NULL && ctrl->is_Proj())
1157 ctrl = ctrl->in(0);
1158
1159 return ctrl;
1160 }
1161
1162 //--------------------------dominates------------------------------------------
1163 // Helper function for MemNode::all_controls_dominate().
1164 // Check if 'this' control node dominates or equal to 'sub' control node.
1165 // We already know that if any path back to Root or Start reaches 'this',
1166 // then all paths so, so this is a simple search for one example,
1167 // not an exhaustive search for a counterexample.
1168 bool Node::dominates(Node* sub, Node_List &nlist) {
1169 assert(this->is_CFG(), "expecting control");
1170 assert(sub != NULL && sub->is_CFG(), "expecting control");
1171
1172 // detect dead cycle without regions
1173 int iterations_without_region_limit = DominatorSearchLimit;
1174
1175 Node* orig_sub = sub;
1176 Node* dom = this;
1177 bool met_dom = false;
1178 nlist.clear();
1179
1180 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1181 // After seeing 'dom', continue up to Root or Start.
1182 // If we hit a region (backward split point), it may be a loop head.
1183 // Keep going through one of the region's inputs. If we reach the
1184 // same region again, go through a different input. Eventually we
1185 // will either exit through the loop head, or give up.
1186 // (If we get confused, break out and return a conservative 'false'.)
1187 while (sub != NULL) {
1188 if (sub->is_top()) break; // Conservative answer for dead code.
1189 if (sub == dom) {
1190 if (nlist.size() == 0) {
1191 // No Region nodes except loops were visited before and the EntryControl
1192 // path was taken for loops: it did not walk in a cycle.
1193 return true;
1194 } else if (met_dom) {
1195 break; // already met before: walk in a cycle
1196 } else {
1197 // Region nodes were visited. Continue walk up to Start or Root
1198 // to make sure that it did not walk in a cycle.
1199 met_dom = true; // first time meet
1200 iterations_without_region_limit = DominatorSearchLimit; // Reset
1201 }
1202 }
1203 if (sub->is_Start() || sub->is_Root()) {
1204 // Success if we met 'dom' along a path to Start or Root.
1205 // We assume there are no alternative paths that avoid 'dom'.
1206 // (This assumption is up to the caller to ensure!)
1207 return met_dom;
1208 }
1209 Node* up = sub->in(0);
1210 // Normalize simple pass-through regions and projections:
1211 up = sub->find_exact_control(up);
1212 // If sub == up, we found a self-loop. Try to push past it.
1213 if (sub == up && sub->is_Loop()) {
1214 // Take loop entry path on the way up to 'dom'.
1215 up = sub->in(1); // in(LoopNode::EntryControl);
1216 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1217 // Always take in(1) path on the way up to 'dom' for clone regions
1218 // (with only one input) or regions which merge > 2 paths
1219 // (usually used to merge fast/slow paths).
1220 up = sub->in(1);
1221 } else if (sub == up && sub->is_Region()) {
1222 // Try both paths for Regions with 2 input paths (it may be a loop head).
1223 // It could give conservative 'false' answer without information
1224 // which region's input is the entry path.
1225 iterations_without_region_limit = DominatorSearchLimit; // Reset
1226
1227 bool region_was_visited_before = false;
1228 // Was this Region node visited before?
1229 // If so, we have reached it because we accidentally took a
1230 // loop-back edge from 'sub' back into the body of the loop,
1231 // and worked our way up again to the loop header 'sub'.
1232 // So, take the first unexplored path on the way up to 'dom'.
1233 for (int j = nlist.size() - 1; j >= 0; j--) {
1234 intptr_t ni = (intptr_t)nlist.at(j);
1235 Node* visited = (Node*)(ni & ~1);
1236 bool visited_twice_already = ((ni & 1) != 0);
1237 if (visited == sub) {
1238 if (visited_twice_already) {
1239 // Visited 2 paths, but still stuck in loop body. Give up.
1240 return false;
1241 }
1242 // The Region node was visited before only once.
1243 // (We will repush with the low bit set, below.)
1244 nlist.remove(j);
1245 // We will find a new edge and re-insert.
1246 region_was_visited_before = true;
1247 break;
1248 }
1249 }
1250
1251 // Find an incoming edge which has not been seen yet; walk through it.
1252 assert(up == sub, "");
1253 uint skip = region_was_visited_before ? 1 : 0;
1254 for (uint i = 1; i < sub->req(); i++) {
1255 Node* in = sub->in(i);
1256 if (in != NULL && !in->is_top() && in != sub) {
1257 if (skip == 0) {
1258 up = in;
1259 break;
1260 }
1261 --skip; // skip this nontrivial input
1262 }
1263 }
1264
1265 // Set 0 bit to indicate that both paths were taken.
1266 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1267 }
1268
1269 if (up == sub) {
1270 break; // some kind of tight cycle
1271 }
1272 if (up == orig_sub && met_dom) {
1273 // returned back after visiting 'dom'
1274 break; // some kind of cycle
1275 }
1276 if (--iterations_without_region_limit < 0) {
1277 break; // dead cycle
1278 }
1279 sub = up;
1280 }
1281
1282 // Did not meet Root or Start node in pred. chain.
1283 // Conservative answer for dead code.
1284 return false;
1285 }
1286
1287 //------------------------------remove_dead_region-----------------------------
1288 // This control node is dead. Follow the subgraph below it making everything
1289 // using it dead as well. This will happen normally via the usual IterGVN
1290 // worklist but this call is more efficient. Do not update use-def info
1291 // inside the dead region, just at the borders.
1292 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1293 // Con's are a popular node to re-hit in the hash table again.
1294 if( dead->is_Con() ) return;
1295
1296 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1297 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1298 Node_List nstack(Thread::current()->resource_area());
1299
1300 Node *top = igvn->C->top();
1301 nstack.push(dead);
1302 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1303
1304 while (nstack.size() > 0) {
1305 dead = nstack.pop();
1306 if (dead->outcnt() > 0) {
1307 // Keep dead node on stack until all uses are processed.
1308 nstack.push(dead);
1309 // For all Users of the Dead... ;-)
1310 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1311 Node* use = dead->last_out(k);
1312 igvn->hash_delete(use); // Yank from hash table prior to mod
1313 if (use->in(0) == dead) { // Found another dead node
1314 assert (!use->is_Con(), "Control for Con node should be Root node.");
1315 use->set_req(0, top); // Cut dead edge to prevent processing
1316 nstack.push(use); // the dead node again.
1317 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1318 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1319 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1320 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1321 use->set_req(0, top); // Cut self edge
1322 nstack.push(use);
1323 } else { // Else found a not-dead user
1324 // Dead if all inputs are top or null
1325 bool dead_use = !use->is_Root(); // Keep empty graph alive
1326 for (uint j = 1; j < use->req(); j++) {
1327 Node* in = use->in(j);
1328 if (in == dead) { // Turn all dead inputs into TOP
1329 use->set_req(j, top);
1330 } else if (in != NULL && !in->is_top()) {
1331 dead_use = false;
1332 }
1333 }
1334 if (dead_use) {
1335 if (use->is_Region()) {
1336 use->set_req(0, top); // Cut self edge
1337 }
1338 nstack.push(use);
1339 } else {
1340 igvn->_worklist.push(use);
1341 }
1342 }
1343 // Refresh the iterator, since any number of kills might have happened.
1344 k = dead->last_outs(kmin);
1345 }
1346 } else { // (dead->outcnt() == 0)
1347 // Done with outputs.
1348 igvn->hash_delete(dead);
1349 igvn->_worklist.remove(dead);
1350 igvn->set_type(dead, Type::TOP);
1351 if (dead->is_macro()) {
1352 igvn->C->remove_macro_node(dead);
1353 }
1354 if (dead->is_expensive()) {
1355 igvn->C->remove_expensive_node(dead);
1356 }
1357 CastIINode* cast = dead->isa_CastII();
1358 if (cast != NULL && cast->has_range_check()) {
1359 igvn->C->remove_range_check_cast(cast);
1360 }
1361 igvn->C->record_dead_node(dead->_idx);
1362 // Kill all inputs to the dead guy
1363 for (uint i=0; i < dead->req(); i++) {
1364 Node *n = dead->in(i); // Get input to dead guy
1365 if (n != NULL && !n->is_top()) { // Input is valid?
1366 dead->set_req(i, top); // Smash input away
1367 if (n->outcnt() == 0) { // Input also goes dead?
1368 if (!n->is_Con())
1369 nstack.push(n); // Clear it out as well
1370 } else if (n->outcnt() == 1 &&
1371 n->has_special_unique_user()) {
1372 igvn->add_users_to_worklist( n );
1373 } else if (n->outcnt() <= 2 && n->is_Store()) {
1374 // Push store's uses on worklist to enable folding optimization for
1375 // store/store and store/load to the same address.
1376 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1377 // and remove_globally_dead_node().
1378 igvn->add_users_to_worklist( n );
1379 }
1380 }
1381 }
1382 } // (dead->outcnt() == 0)
1383 } // while (nstack.size() > 0) for outputs
1384 return;
1385 }
1386
1387 //------------------------------remove_dead_region-----------------------------
1388 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1389 Node *n = in(0);
1390 if( !n ) return false;
1391 // Lost control into this guy? I.e., it became unreachable?
1392 // Aggressively kill all unreachable code.
1393 if (can_reshape && n->is_top()) {
1394 kill_dead_code(this, phase->is_IterGVN());
1395 return false; // Node is dead.
1396 }
1397
1398 if( n->is_Region() && n->as_Region()->is_copy() ) {
1399 Node *m = n->nonnull_req();
1400 set_req(0, m);
1401 return true;
1402 }
1403 return false;
1404 }
1405
1406 //------------------------------Ideal_DU_postCCP-------------------------------
1407 // Idealize graph, using DU info. Must clone result into new-space
1408 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1409 return NULL; // Default to no change
1410 }
1411
1412 //------------------------------hash-------------------------------------------
1413 // Hash function over Nodes.
1414 uint Node::hash() const {
1415 uint sum = 0;
1416 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1417 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1418 return (sum>>2) + _cnt + Opcode();
1419 }
1420
1421 //------------------------------cmp--------------------------------------------
1422 // Compare special parts of simple Nodes
1423 uint Node::cmp( const Node &n ) const {
1424 return 1; // Must be same
1425 }
1426
1427 //------------------------------rematerialize-----------------------------------
1428 // Should we clone rather than spill this instruction?
1429 bool Node::rematerialize() const {
1430 if ( is_Mach() )
1431 return this->as_Mach()->rematerialize();
1432 else
1433 return (_flags & Flag_rematerialize) != 0;
1434 }
1435
1436 //------------------------------needs_anti_dependence_check---------------------
1437 // Nodes which use memory without consuming it, hence need antidependences.
1438 bool Node::needs_anti_dependence_check() const {
1439 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1440 return false;
1441 else
1442 return in(1)->bottom_type()->has_memory();
1443 }
1444
1445
1446 // Get an integer constant from a ConNode (or CastIINode).
1447 // Return a default value if there is no apparent constant here.
1448 const TypeInt* Node::find_int_type() const {
1449 if (this->is_Type()) {
1450 return this->as_Type()->type()->isa_int();
1451 } else if (this->is_Con()) {
1452 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1453 return this->bottom_type()->isa_int();
1454 }
1455 return NULL;
1456 }
1457
1458 // Get a pointer constant from a ConstNode.
1459 // Returns the constant if it is a pointer ConstNode
1460 intptr_t Node::get_ptr() const {
1461 assert( Opcode() == Op_ConP, "" );
1462 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1463 }
1464
1465 // Get a narrow oop constant from a ConNNode.
1466 intptr_t Node::get_narrowcon() const {
1467 assert( Opcode() == Op_ConN, "" );
1468 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1469 }
1470
1471 // Get a long constant from a ConNode.
1472 // Return a default value if there is no apparent constant here.
1473 const TypeLong* Node::find_long_type() const {
1474 if (this->is_Type()) {
1475 return this->as_Type()->type()->isa_long();
1476 } else if (this->is_Con()) {
1477 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1478 return this->bottom_type()->isa_long();
1479 }
1480 return NULL;
1481 }
1482
1483
1484 /**
1485 * Return a ptr type for nodes which should have it.
1486 */
1487 const TypePtr* Node::get_ptr_type() const {
1488 const TypePtr* tp = this->bottom_type()->make_ptr();
1489 #ifdef ASSERT
1490 if (tp == NULL) {
1491 this->dump(1);
1492 assert((tp != NULL), "unexpected node type");
1493 }
1494 #endif
1495 return tp;
1496 }
1497
1498 // Get a double constant from a ConstNode.
1499 // Returns the constant if it is a double ConstNode
1500 jdouble Node::getd() const {
1501 assert( Opcode() == Op_ConD, "" );
1502 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1503 }
1504
1505 // Get a float constant from a ConstNode.
1506 // Returns the constant if it is a float ConstNode
1507 jfloat Node::getf() const {
1508 assert( Opcode() == Op_ConF, "" );
1509 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1510 }
1511
1512 #ifndef PRODUCT
1513
1514 //----------------------------NotANode----------------------------------------
1515 // Used in debugging code to avoid walking across dead or uninitialized edges.
1516 static inline bool NotANode(const Node* n) {
1517 if (n == NULL) return true;
1518 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1519 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1520 return false;
1521 }
1522
1523
1524 //------------------------------find------------------------------------------
1525 // Find a neighbor of this Node with the given _idx
1526 // If idx is negative, find its absolute value, following both _in and _out.
1527 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1528 VectorSet* old_space, VectorSet* new_space ) {
1529 int node_idx = (idx >= 0) ? idx : -idx;
1530 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1531 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1532 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1533 if( v->test(n->_idx) ) return;
1534 if( (int)n->_idx == node_idx
1535 debug_only(|| n->debug_idx() == node_idx) ) {
1536 if (result != NULL)
1537 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1538 (uintptr_t)result, (uintptr_t)n, node_idx);
1539 result = n;
1540 }
1541 v->set(n->_idx);
1542 for( uint i=0; i<n->len(); i++ ) {
1543 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1544 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1545 }
1546 // Search along forward edges also:
1547 if (idx < 0 && !only_ctrl) {
1548 for( uint j=0; j<n->outcnt(); j++ ) {
1549 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1550 }
1551 }
1552 #ifdef ASSERT
1553 // Search along debug_orig edges last, checking for cycles
1554 Node* orig = n->debug_orig();
1555 if (orig != NULL) {
1556 do {
1557 if (NotANode(orig)) break;
1558 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1559 orig = orig->debug_orig();
1560 } while (orig != NULL && orig != n->debug_orig());
1561 }
1562 #endif //ASSERT
1563 }
1564
1565 // call this from debugger:
1566 Node* find_node(Node* n, int idx) {
1567 return n->find(idx);
1568 }
1569
1570 //------------------------------find-------------------------------------------
1571 Node* Node::find(int idx) const {
1572 ResourceArea *area = Thread::current()->resource_area();
1573 VectorSet old_space(area), new_space(area);
1574 Node* result = NULL;
1575 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1576 return result;
1577 }
1578
1579 //------------------------------find_ctrl--------------------------------------
1580 // Find an ancestor to this node in the control history with given _idx
1581 Node* Node::find_ctrl(int idx) const {
1582 ResourceArea *area = Thread::current()->resource_area();
1583 VectorSet old_space(area), new_space(area);
1584 Node* result = NULL;
1585 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1586 return result;
1587 }
1588 #endif
1589
1590
1591
1592 #ifndef PRODUCT
1593
1594 // -----------------------------Name-------------------------------------------
1595 extern const char *NodeClassNames[];
1596 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1597
1598 static bool is_disconnected(const Node* n) {
1599 for (uint i = 0; i < n->req(); i++) {
1600 if (n->in(i) != NULL) return false;
1601 }
1602 return true;
1603 }
1604
1605 #ifdef ASSERT
1606 static void dump_orig(Node* orig, outputStream *st) {
1607 Compile* C = Compile::current();
1608 if (NotANode(orig)) orig = NULL;
1609 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1610 if (orig == NULL) return;
1611 st->print(" !orig=");
1612 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1613 if (NotANode(fast)) fast = NULL;
1614 while (orig != NULL) {
1615 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1616 if (discon) st->print("[");
1617 if (!Compile::current()->node_arena()->contains(orig))
1618 st->print("o");
1619 st->print("%d", orig->_idx);
1620 if (discon) st->print("]");
1621 orig = orig->debug_orig();
1622 if (NotANode(orig)) orig = NULL;
1623 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1624 if (orig != NULL) st->print(",");
1625 if (fast != NULL) {
1626 // Step fast twice for each single step of orig:
1627 fast = fast->debug_orig();
1628 if (NotANode(fast)) fast = NULL;
1629 if (fast != NULL && fast != orig) {
1630 fast = fast->debug_orig();
1631 if (NotANode(fast)) fast = NULL;
1632 }
1633 if (fast == orig) {
1634 st->print("...");
1635 break;
1636 }
1637 }
1638 }
1639 }
1640
1641 void Node::set_debug_orig(Node* orig) {
1642 _debug_orig = orig;
1643 if (BreakAtNode == 0) return;
1644 if (NotANode(orig)) orig = NULL;
1645 int trip = 10;
1646 while (orig != NULL) {
1647 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1648 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1649 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1650 BREAKPOINT;
1651 }
1652 orig = orig->debug_orig();
1653 if (NotANode(orig)) orig = NULL;
1654 if (trip-- <= 0) break;
1655 }
1656 }
1657 #endif //ASSERT
1658
1659 //------------------------------dump------------------------------------------
1660 // Dump a Node
1661 void Node::dump(const char* suffix, outputStream *st) const {
1662 Compile* C = Compile::current();
1663 bool is_new = C->node_arena()->contains(this);
1664 C->_in_dump_cnt++;
1665 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1666
1667 // Dump the required and precedence inputs
1668 dump_req(st);
1669 dump_prec(st);
1670 // Dump the outputs
1671 dump_out(st);
1672
1673 if (is_disconnected(this)) {
1674 #ifdef ASSERT
1675 st->print(" [%d]",debug_idx());
1676 dump_orig(debug_orig(), st);
1677 #endif
1678 st->cr();
1679 C->_in_dump_cnt--;
1680 return; // don't process dead nodes
1681 }
1682
1683 // Dump node-specific info
1684 dump_spec(st);
1685 #ifdef ASSERT
1686 // Dump the non-reset _debug_idx
1687 if (Verbose && WizardMode) {
1688 st->print(" [%d]",debug_idx());
1689 }
1690 #endif
1691
1692 const Type *t = bottom_type();
1693
1694 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1695 const TypeInstPtr *toop = t->isa_instptr();
1696 const TypeKlassPtr *tkls = t->isa_klassptr();
1697 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1698 if (klass && klass->is_loaded() && klass->is_interface()) {
1699 st->print(" Interface:");
1700 } else if (toop) {
1701 st->print(" Oop:");
1702 } else if (tkls) {
1703 st->print(" Klass:");
1704 }
1705 t->dump_on(st);
1706 } else if (t == Type::MEMORY) {
1707 st->print(" Memory:");
1708 MemNode::dump_adr_type(this, adr_type(), st);
1709 } else if (Verbose || WizardMode) {
1710 st->print(" Type:");
1711 if (t) {
1712 t->dump_on(st);
1713 } else {
1714 st->print("no type");
1715 }
1716 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1717 // Dump MachSpillcopy vector type.
1718 t->dump_on(st);
1719 }
1720 if (is_new) {
1721 debug_only(dump_orig(debug_orig(), st));
1722 Node_Notes* nn = C->node_notes_at(_idx);
1723 if (nn != NULL && !nn->is_clear()) {
1724 if (nn->jvms() != NULL) {
1725 st->print(" !jvms:");
1726 nn->jvms()->dump_spec(st);
1727 }
1728 }
1729 }
1730 if (suffix) st->print("%s", suffix);
1731 C->_in_dump_cnt--;
1732 }
1733
1734 //------------------------------dump_req--------------------------------------
1735 void Node::dump_req(outputStream *st) const {
1736 // Dump the required input edges
1737 for (uint i = 0; i < req(); i++) { // For all required inputs
1738 Node* d = in(i);
1739 if (d == NULL) {
1740 st->print("_ ");
1741 } else if (NotANode(d)) {
1742 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1743 } else {
1744 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1745 }
1746 }
1747 }
1748
1749
1750 //------------------------------dump_prec-------------------------------------
1751 void Node::dump_prec(outputStream *st) const {
1752 // Dump the precedence edges
1753 int any_prec = 0;
1754 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1755 Node* p = in(i);
1756 if (p != NULL) {
1757 if (!any_prec++) st->print(" |");
1758 if (NotANode(p)) { st->print("NotANode "); continue; }
1759 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1760 }
1761 }
1762 }
1763
1764 //------------------------------dump_out--------------------------------------
1765 void Node::dump_out(outputStream *st) const {
1766 // Delimit the output edges
1767 st->print(" [[");
1768 // Dump the output edges
1769 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1770 Node* u = _out[i];
1771 if (u == NULL) {
1772 st->print("_ ");
1773 } else if (NotANode(u)) {
1774 st->print("NotANode ");
1775 } else {
1776 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1777 }
1778 }
1779 st->print("]] ");
1780 }
1781
1782 //------------------------------dump_nodes-------------------------------------
1783 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1784 Node* s = (Node*)start; // remove const
1785 if (NotANode(s)) return;
1786
1787 uint depth = (uint)ABS(d);
1788 int direction = d;
1789 Compile* C = Compile::current();
1790 GrowableArray <Node *> nstack(C->live_nodes());
1791
1792 nstack.append(s);
1793 int begin = 0;
1794 int end = 0;
1795 for(uint i = 0; i < depth; i++) {
1796 end = nstack.length();
1797 for(int j = begin; j < end; j++) {
1798 Node* tp = nstack.at(j);
1799 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1800 for(uint k = 0; k < limit; k++) {
1801 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1802
1803 if (NotANode(n)) continue;
1804 // do not recurse through top or the root (would reach unrelated stuff)
1805 if (n->is_Root() || n->is_top()) continue;
1806 if (only_ctrl && !n->is_CFG()) continue;
1807
1808 bool on_stack = nstack.contains(n);
1809 if (!on_stack) {
1810 nstack.append(n);
1811 }
1812 }
1813 }
1814 begin = end;
1815 }
1816 end = nstack.length();
1817 if (direction > 0) {
1818 for(int j = end-1; j >= 0; j--) {
1819 nstack.at(j)->dump();
1820 }
1821 } else {
1822 for(int j = 0; j < end; j++) {
1823 nstack.at(j)->dump();
1824 }
1825 }
1826 }
1827
1828 //------------------------------dump-------------------------------------------
1829 void Node::dump(int d) const {
1830 dump_nodes(this, d, false);
1831 }
1832
1833 //------------------------------dump_ctrl--------------------------------------
1834 // Dump a Node's control history to depth
1835 void Node::dump_ctrl(int d) const {
1836 dump_nodes(this, d, true);
1837 }
1838
1839 // VERIFICATION CODE
1840 // For each input edge to a node (ie - for each Use-Def edge), verify that
1841 // there is a corresponding Def-Use edge.
1842 //------------------------------verify_edges-----------------------------------
1843 void Node::verify_edges(Unique_Node_List &visited) {
1844 uint i, j, idx;
1845 int cnt;
1846 Node *n;
1847
1848 // Recursive termination test
1849 if (visited.member(this)) return;
1850 visited.push(this);
1851
1852 // Walk over all input edges, checking for correspondence
1853 for( i = 0; i < len(); i++ ) {
1854 n = in(i);
1855 if (n != NULL && !n->is_top()) {
1856 // Count instances of (Node *)this
1857 cnt = 0;
1858 for (idx = 0; idx < n->_outcnt; idx++ ) {
1859 if (n->_out[idx] == (Node *)this) cnt++;
1860 }
1861 assert( cnt > 0,"Failed to find Def-Use edge." );
1862 // Check for duplicate edges
1863 // walk the input array downcounting the input edges to n
1864 for( j = 0; j < len(); j++ ) {
1865 if( in(j) == n ) cnt--;
1866 }
1867 assert( cnt == 0,"Mismatched edge count.");
1868 } else if (n == NULL) {
1869 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1870 } else {
1871 assert(n->is_top(), "sanity");
1872 // Nothing to check.
1873 }
1874 }
1875 // Recursive walk over all input edges
1876 for( i = 0; i < len(); i++ ) {
1877 n = in(i);
1878 if( n != NULL )
1879 in(i)->verify_edges(visited);
1880 }
1881 }
1882
1883 //------------------------------verify_recur-----------------------------------
1884 static const Node *unique_top = NULL;
1885
1886 void Node::verify_recur(const Node *n, int verify_depth,
1887 VectorSet &old_space, VectorSet &new_space) {
1888 if ( verify_depth == 0 ) return;
1889 if (verify_depth > 0) --verify_depth;
1890
1891 Compile* C = Compile::current();
1892
1893 // Contained in new_space or old_space?
1894 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1895 // Check for visited in the proper space. Numberings are not unique
1896 // across spaces so we need a separate VectorSet for each space.
1897 if( v->test_set(n->_idx) ) return;
1898
1899 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1900 if (C->cached_top_node() == NULL)
1901 C->set_cached_top_node((Node*)n);
1902 assert(C->cached_top_node() == n, "TOP node must be unique");
1903 }
1904
1905 for( uint i = 0; i < n->len(); i++ ) {
1906 Node *x = n->in(i);
1907 if (!x || x->is_top()) continue;
1908
1909 // Verify my input has a def-use edge to me
1910 if (true /*VerifyDefUse*/) {
1911 // Count use-def edges from n to x
1912 int cnt = 0;
1913 for( uint j = 0; j < n->len(); j++ )
1914 if( n->in(j) == x )
1915 cnt++;
1916 // Count def-use edges from x to n
1917 uint max = x->_outcnt;
1918 for( uint k = 0; k < max; k++ )
1919 if (x->_out[k] == n)
1920 cnt--;
1921 assert( cnt == 0, "mismatched def-use edge counts" );
1922 }
1923
1924 verify_recur(x, verify_depth, old_space, new_space);
1925 }
1926
1927 }
1928
1929 //------------------------------verify-----------------------------------------
1930 // Check Def-Use info for my subgraph
1931 void Node::verify() const {
1932 Compile* C = Compile::current();
1933 Node* old_top = C->cached_top_node();
1934 ResourceMark rm;
1935 ResourceArea *area = Thread::current()->resource_area();
1936 VectorSet old_space(area), new_space(area);
1937 verify_recur(this, -1, old_space, new_space);
1938 C->set_cached_top_node(old_top);
1939 }
1940 #endif
1941
1942
1943 //------------------------------walk-------------------------------------------
1944 // Graph walk, with both pre-order and post-order functions
1945 void Node::walk(NFunc pre, NFunc post, void *env) {
1946 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1947 walk_(pre, post, env, visited);
1948 }
1949
1950 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1951 if( visited.test_set(_idx) ) return;
1952 pre(*this,env); // Call the pre-order walk function
1953 for( uint i=0; i<_max; i++ )
1954 if( in(i) ) // Input exists and is not walked?
1955 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1956 post(*this,env); // Call the post-order walk function
1957 }
1958
1959 void Node::nop(Node &, void*) {}
1960
1961 //------------------------------Registers--------------------------------------
1962 // Do we Match on this edge index or not? Generally false for Control
1963 // and true for everything else. Weird for calls & returns.
1964 uint Node::match_edge(uint idx) const {
1965 return idx; // True for other than index 0 (control)
1966 }
1967
1968 static RegMask _not_used_at_all;
1969 // Register classes are defined for specific machines
1970 const RegMask &Node::out_RegMask() const {
1971 ShouldNotCallThis();
1972 return _not_used_at_all;
1973 }
1974
1975 const RegMask &Node::in_RegMask(uint) const {
1976 ShouldNotCallThis();
1977 return _not_used_at_all;
1978 }
1979
1980 //=============================================================================
1981 //-----------------------------------------------------------------------------
1982 void Node_Array::reset( Arena *new_arena ) {
1983 _a->Afree(_nodes,_max*sizeof(Node*));
1984 _max = 0;
1985 _nodes = NULL;
1986 _a = new_arena;
1987 }
1988
1989 //------------------------------clear------------------------------------------
1990 // Clear all entries in _nodes to NULL but keep storage
1991 void Node_Array::clear() {
1992 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1993 }
1994
1995 //-----------------------------------------------------------------------------
1996 void Node_Array::grow( uint i ) {
1997 if( !_max ) {
1998 _max = 1;
1999 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2000 _nodes[0] = NULL;
2001 }
2002 uint old = _max;
2003 while( i >= _max ) _max <<= 1; // Double to fit
2004 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2005 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2006 }
2007
2008 //-----------------------------------------------------------------------------
2009 void Node_Array::insert( uint i, Node *n ) {
2010 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2011 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2012 _nodes[i] = n;
2013 }
2014
2015 //-----------------------------------------------------------------------------
2016 void Node_Array::remove( uint i ) {
2017 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2018 _nodes[_max-1] = NULL;
2019 }
2020
2021 //-----------------------------------------------------------------------------
2022 void Node_Array::sort( C_sort_func_t func) {
2023 qsort( _nodes, _max, sizeof( Node* ), func );
2024 }
2025
2026 //-----------------------------------------------------------------------------
2027 void Node_Array::dump() const {
2028 #ifndef PRODUCT
2029 for( uint i = 0; i < _max; i++ ) {
2030 Node *nn = _nodes[i];
2031 if( nn != NULL ) {
2032 tty->print("%5d--> ",i); nn->dump();
2033 }
2034 }
2035 #endif
2036 }
2037
2038 //--------------------------is_iteratively_computed------------------------------
2039 // Operation appears to be iteratively computed (such as an induction variable)
2040 // It is possible for this operation to return false for a loop-varying
2041 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2042 bool Node::is_iteratively_computed() {
2043 if (ideal_reg()) { // does operation have a result register?
2044 for (uint i = 1; i < req(); i++) {
2045 Node* n = in(i);
2046 if (n != NULL && n->is_Phi()) {
2047 for (uint j = 1; j < n->req(); j++) {
2048 if (n->in(j) == this) {
2049 return true;
2050 }
2051 }
2052 }
2053 }
2054 }
2055 return false;
2056 }
2057
2058 //--------------------------find_similar------------------------------
2059 // Return a node with opcode "opc" and same inputs as "this" if one can
2060 // be found; Otherwise return NULL;
2061 Node* Node::find_similar(int opc) {
2062 if (req() >= 2) {
2063 Node* def = in(1);
2064 if (def && def->outcnt() >= 2) {
2065 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2066 Node* use = def->fast_out(i);
2067 if (use->Opcode() == opc &&
2068 use->req() == req()) {
2069 uint j;
2070 for (j = 0; j < use->req(); j++) {
2071 if (use->in(j) != in(j)) {
2072 break;
2073 }
2074 }
2075 if (j == use->req()) {
2076 return use;
2077 }
2078 }
2079 }
2080 }
2081 }
2082 return NULL;
2083 }
2084
2085
2086 //--------------------------unique_ctrl_out------------------------------
2087 // Return the unique control out if only one. Null if none or more than one.
2088 Node* Node::unique_ctrl_out() {
2089 Node* found = NULL;
2090 for (uint i = 0; i < outcnt(); i++) {
2091 Node* use = raw_out(i);
2092 if (use->is_CFG() && use != this) {
2093 if (found != NULL) return NULL;
2094 found = use;
2095 }
2096 }
2097 return found;
2098 }
2099
2100 //=============================================================================
2101 //------------------------------yank-------------------------------------------
2102 // Find and remove
2103 void Node_List::yank( Node *n ) {
2104 uint i;
2105 for( i = 0; i < _cnt; i++ )
2106 if( _nodes[i] == n )
2107 break;
2108
2109 if( i < _cnt )
2110 _nodes[i] = _nodes[--_cnt];
2111 }
2112
2113 //------------------------------dump-------------------------------------------
2114 void Node_List::dump() const {
2115 #ifndef PRODUCT
2116 for( uint i = 0; i < _cnt; i++ )
2117 if( _nodes[i] ) {
2118 tty->print("%5d--> ",i);
2119 _nodes[i]->dump();
2120 }
2121 #endif
2122 }
2123
2124 void Node_List::dump_simple() const {
2125 #ifndef PRODUCT
2126 for( uint i = 0; i < _cnt; i++ )
2127 if( _nodes[i] ) {
2128 tty->print(" %d", _nodes[i]->_idx);
2129 } else {
2130 tty->print(" NULL");
2131 }
2132 #endif
2133 }
2134
2135 //=============================================================================
2136 //------------------------------remove-----------------------------------------
2137 void Unique_Node_List::remove( Node *n ) {
2138 if( _in_worklist[n->_idx] ) {
2139 for( uint i = 0; i < size(); i++ )
2140 if( _nodes[i] == n ) {
2141 map(i,Node_List::pop());
2142 _in_worklist >>= n->_idx;
2143 return;
2144 }
2145 ShouldNotReachHere();
2146 }
2147 }
2148
2149 //-----------------------remove_useless_nodes----------------------------------
2150 // Remove useless nodes from worklist
2151 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2152
2153 for( uint i = 0; i < size(); ++i ) {
2154 Node *n = at(i);
2155 assert( n != NULL, "Did not expect null entries in worklist");
2156 if( ! useful.test(n->_idx) ) {
2157 _in_worklist >>= n->_idx;
2158 map(i,Node_List::pop());
2159 // Node *replacement = Node_List::pop();
2160 // if( i != size() ) { // Check if removing last entry
2161 // _nodes[i] = replacement;
2162 // }
2163 --i; // Visit popped node
2164 // If it was last entry, loop terminates since size() was also reduced
2165 }
2166 }
2167 }
2168
2169 //=============================================================================
2170 void Node_Stack::grow() {
2171 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2172 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2173 size_t max = old_max << 1; // max * 2
2174 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2175 _inode_max = _inodes + max;
2176 _inode_top = _inodes + old_top; // restore _top
2177 }
2178
2179 // Node_Stack is used to map nodes.
2180 Node* Node_Stack::find(uint idx) const {
2181 uint sz = size();
2182 for (uint i=0; i < sz; i++) {
2183 if (idx == index_at(i) )
2184 return node_at(i);
2185 }
2186 return NULL;
2187 }
2188
2189 //=============================================================================
2190 uint TypeNode::size_of() const { return sizeof(*this); }
2191 #ifndef PRODUCT
2192 void TypeNode::dump_spec(outputStream *st) const {
2193 if( !Verbose && !WizardMode ) {
2194 // standard dump does this in Verbose and WizardMode
2195 st->print(" #"); _type->dump_on(st);
2196 }
2197 }
2198 #endif
2199 uint TypeNode::hash() const {
2200 return Node::hash() + _type->hash();
2201 }
2202 uint TypeNode::cmp( const Node &n ) const
2203 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2204 const Type *TypeNode::bottom_type() const { return _type; }
2205 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2206
2207 //------------------------------ideal_reg--------------------------------------
2208 uint TypeNode::ideal_reg() const {
2209 return _type->ideal_reg();
2210 }