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