1 /*
2 * Copyright (c) 1997, 2016, 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 "memory/resourceArea.hpp"
29 #include "opto/castnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/connode.hpp"
32 #include "opto/loopnode.hpp"
33 #include "opto/machnode.hpp"
34 #include "opto/matcher.hpp"
35 #include "opto/node.hpp"
36 #include "opto/opcodes.hpp"
37 #include "opto/regmask.hpp"
38 #include "opto/type.hpp"
39 #include "utilities/copy.hpp"
40
41 class RegMask;
42 // #include "phase.hpp"
43 class PhaseTransform;
44 class PhaseGVN;
45
46 // Arena we are currently building Nodes in
47 const uint Node::NotAMachineReg = 0xffff0000;
48
49 #ifndef PRODUCT
50 extern int nodes_created;
51 #endif
52 #ifdef __clang__
53 #pragma clang diagnostic push
54 #pragma GCC diagnostic ignored "-Wuninitialized"
55 #endif
56
57 #ifdef ASSERT
58
59 //-------------------------- construct_node------------------------------------
60 // Set a breakpoint here to identify where a particular node index is built.
61 void Node::verify_construction() {
62 _debug_orig = NULL;
63 int old_debug_idx = Compile::debug_idx();
64 int new_debug_idx = old_debug_idx+1;
65 if (new_debug_idx > 0) {
66 // Arrange that the lowest five decimal digits of _debug_idx
67 // will repeat those of _idx. In case this is somehow pathological,
68 // we continue to assign negative numbers (!) consecutively.
69 const int mod = 100000;
70 int bump = (int)(_idx - new_debug_idx) % mod;
71 if (bump < 0) bump += mod;
72 assert(bump >= 0 && bump < mod, "");
73 new_debug_idx += bump;
74 }
75 Compile::set_debug_idx(new_debug_idx);
76 set_debug_idx( new_debug_idx );
77 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
78 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
79 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
80 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
81 BREAKPOINT;
82 }
83 #if OPTO_DU_ITERATOR_ASSERT
84 _last_del = NULL;
85 _del_tick = 0;
86 #endif
87 _hash_lock = 0;
88 }
89
90
91 // #ifdef ASSERT ...
92
93 #if OPTO_DU_ITERATOR_ASSERT
94 void DUIterator_Common::sample(const Node* node) {
95 _vdui = VerifyDUIterators;
96 _node = node;
97 _outcnt = node->_outcnt;
98 _del_tick = node->_del_tick;
99 _last = NULL;
100 }
101
102 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
103 assert(_node == node, "consistent iterator source");
104 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
105 }
106
107 void DUIterator_Common::verify_resync() {
108 // Ensure that the loop body has just deleted the last guy produced.
109 const Node* node = _node;
110 // Ensure that at least one copy of the last-seen edge was deleted.
111 // Note: It is OK to delete multiple copies of the last-seen edge.
112 // Unfortunately, we have no way to verify that all the deletions delete
113 // that same edge. On this point we must use the Honor System.
114 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
115 assert(node->_last_del == _last, "must have deleted the edge just produced");
116 // We liked this deletion, so accept the resulting outcnt and tick.
117 _outcnt = node->_outcnt;
118 _del_tick = node->_del_tick;
119 }
120
121 void DUIterator_Common::reset(const DUIterator_Common& that) {
122 if (this == &that) return; // ignore assignment to self
123 if (!_vdui) {
124 // We need to initialize everything, overwriting garbage values.
125 _last = that._last;
126 _vdui = that._vdui;
127 }
128 // Note: It is legal (though odd) for an iterator over some node x
129 // to be reassigned to iterate over another node y. Some doubly-nested
130 // progress loops depend on being able to do this.
131 const Node* node = that._node;
132 // Re-initialize everything, except _last.
133 _node = node;
134 _outcnt = node->_outcnt;
135 _del_tick = node->_del_tick;
136 }
137
138 void DUIterator::sample(const Node* node) {
139 DUIterator_Common::sample(node); // Initialize the assertion data.
140 _refresh_tick = 0; // No refreshes have happened, as yet.
141 }
142
143 void DUIterator::verify(const Node* node, bool at_end_ok) {
144 DUIterator_Common::verify(node, at_end_ok);
145 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
146 }
147
148 void DUIterator::verify_increment() {
149 if (_refresh_tick & 1) {
150 // We have refreshed the index during this loop.
151 // Fix up _idx to meet asserts.
152 if (_idx > _outcnt) _idx = _outcnt;
153 }
154 verify(_node, true);
155 }
156
157 void DUIterator::verify_resync() {
158 // Note: We do not assert on _outcnt, because insertions are OK here.
159 DUIterator_Common::verify_resync();
160 // Make sure we are still in sync, possibly with no more out-edges:
161 verify(_node, true);
162 }
163
164 void DUIterator::reset(const DUIterator& that) {
165 if (this == &that) return; // self assignment is always a no-op
166 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
167 assert(that._idx == 0, "assign only the result of Node::outs()");
168 assert(_idx == that._idx, "already assigned _idx");
169 if (!_vdui) {
170 // We need to initialize everything, overwriting garbage values.
171 sample(that._node);
172 } else {
173 DUIterator_Common::reset(that);
174 if (_refresh_tick & 1) {
175 _refresh_tick++; // Clear the "was refreshed" flag.
176 }
177 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
178 }
179 }
180
181 void DUIterator::refresh() {
182 DUIterator_Common::sample(_node); // Re-fetch assertion data.
183 _refresh_tick |= 1; // Set the "was refreshed" flag.
184 }
185
186 void DUIterator::verify_finish() {
187 // If the loop has killed the node, do not require it to re-run.
188 if (_node->_outcnt == 0) _refresh_tick &= ~1;
189 // If this assert triggers, it means that a loop used refresh_out_pos
190 // to re-synch an iteration index, but the loop did not correctly
191 // re-run itself, using a "while (progress)" construct.
192 // This iterator enforces the rule that you must keep trying the loop
193 // until it "runs clean" without any need for refreshing.
194 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
195 }
196
197
198 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
199 DUIterator_Common::verify(node, at_end_ok);
200 Node** out = node->_out;
201 uint cnt = node->_outcnt;
202 assert(cnt == _outcnt, "no insertions allowed");
203 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
204 // This last check is carefully designed to work for NO_OUT_ARRAY.
205 }
206
207 void DUIterator_Fast::verify_limit() {
208 const Node* node = _node;
209 verify(node, true);
210 assert(_outp == node->_out + node->_outcnt, "limit still correct");
211 }
212
213 void DUIterator_Fast::verify_resync() {
214 const Node* node = _node;
215 if (_outp == node->_out + _outcnt) {
216 // Note that the limit imax, not the pointer i, gets updated with the
217 // exact count of deletions. (For the pointer it's always "--i".)
218 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
219 // This is a limit pointer, with a name like "imax".
220 // Fudge the _last field so that the common assert will be happy.
221 _last = (Node*) node->_last_del;
222 DUIterator_Common::verify_resync();
223 } else {
224 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
225 // A normal internal pointer.
226 DUIterator_Common::verify_resync();
227 // Make sure we are still in sync, possibly with no more out-edges:
228 verify(node, true);
229 }
230 }
231
232 void DUIterator_Fast::verify_relimit(uint n) {
233 const Node* node = _node;
234 assert((int)n > 0, "use imax -= n only with a positive count");
235 // This must be a limit pointer, with a name like "imax".
236 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
237 // The reported number of deletions must match what the node saw.
238 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
239 // Fudge the _last field so that the common assert will be happy.
240 _last = (Node*) node->_last_del;
241 DUIterator_Common::verify_resync();
242 }
243
244 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
245 assert(_outp == that._outp, "already assigned _outp");
246 DUIterator_Common::reset(that);
247 }
248
249 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
250 // at_end_ok means the _outp is allowed to underflow by 1
251 _outp += at_end_ok;
252 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
253 _outp -= at_end_ok;
254 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
255 }
256
257 void DUIterator_Last::verify_limit() {
258 // Do not require the limit address to be resynched.
259 //verify(node, true);
260 assert(_outp == _node->_out, "limit still correct");
261 }
262
263 void DUIterator_Last::verify_step(uint num_edges) {
264 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
265 _outcnt -= num_edges;
266 _del_tick += num_edges;
267 // Make sure we are still in sync, possibly with no more out-edges:
268 const Node* node = _node;
269 verify(node, true);
270 assert(node->_last_del == _last, "must have deleted the edge just produced");
271 }
272
273 #endif //OPTO_DU_ITERATOR_ASSERT
274
275
276 #endif //ASSERT
277
278
279 // This constant used to initialize _out may be any non-null value.
280 // The value NULL is reserved for the top node only.
281 #define NO_OUT_ARRAY ((Node**)-1)
282
283 // Out-of-line code from node constructors.
284 // Executed only when extra debug info. is being passed around.
285 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
286 C->set_node_notes_at(idx, nn);
287 }
288
289 // Shared initialization code.
290 inline int Node::Init(int req) {
291 Compile* C = Compile::current();
292 int idx = C->next_unique();
293
294 // Allocate memory for the necessary number of edges.
295 if (req > 0) {
296 // Allocate space for _in array to have double alignment.
297 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
298 }
299 // If there are default notes floating around, capture them:
300 Node_Notes* nn = C->default_node_notes();
301 if (nn != NULL) init_node_notes(C, idx, nn);
302
303 // Note: At this point, C is dead,
304 // and we begin to initialize the new Node.
305
306 _cnt = _max = req;
307 _outcnt = _outmax = 0;
308 _class_id = Class_Node;
309 _flags = 0;
310 _out = NO_OUT_ARRAY;
311 return idx;
312 }
313
314 //------------------------------Node-------------------------------------------
315 // Create a Node, with a given number of required edges.
316 Node::Node(uint req)
317 : _idx(Init(req))
318 #ifdef ASSERT
319 , _parse_idx(_idx)
320 #endif
321 {
322 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
323 debug_only( verify_construction() );
324 NOT_PRODUCT(nodes_created++);
325 if (req == 0) {
326 _in = NULL;
327 } else {
328 Node** to = _in;
329 for(uint i = 0; i < req; i++) {
330 to[i] = NULL;
331 }
332 }
333 }
334
335 //------------------------------Node-------------------------------------------
336 Node::Node(Node *n0)
337 : _idx(Init(1))
338 #ifdef ASSERT
339 , _parse_idx(_idx)
340 #endif
341 {
342 debug_only( verify_construction() );
343 NOT_PRODUCT(nodes_created++);
344 assert( is_not_dead(n0), "can not use dead node");
345 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
346 }
347
348 //------------------------------Node-------------------------------------------
349 Node::Node(Node *n0, Node *n1)
350 : _idx(Init(2))
351 #ifdef ASSERT
352 , _parse_idx(_idx)
353 #endif
354 {
355 debug_only( verify_construction() );
356 NOT_PRODUCT(nodes_created++);
357 assert( is_not_dead(n0), "can not use dead node");
358 assert( is_not_dead(n1), "can not use dead node");
359 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
360 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
361 }
362
363 //------------------------------Node-------------------------------------------
364 Node::Node(Node *n0, Node *n1, Node *n2)
365 : _idx(Init(3))
366 #ifdef ASSERT
367 , _parse_idx(_idx)
368 #endif
369 {
370 debug_only( verify_construction() );
371 NOT_PRODUCT(nodes_created++);
372 assert( is_not_dead(n0), "can not use dead node");
373 assert( is_not_dead(n1), "can not use dead node");
374 assert( is_not_dead(n2), "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 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
378 }
379
380 //------------------------------Node-------------------------------------------
381 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
382 : _idx(Init(4))
383 #ifdef ASSERT
384 , _parse_idx(_idx)
385 #endif
386 {
387 debug_only( verify_construction() );
388 NOT_PRODUCT(nodes_created++);
389 assert( is_not_dead(n0), "can not use dead node");
390 assert( is_not_dead(n1), "can not use dead node");
391 assert( is_not_dead(n2), "can not use dead node");
392 assert( is_not_dead(n3), "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 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
397 }
398
399 //------------------------------Node-------------------------------------------
400 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
401 : _idx(Init(5))
402 #ifdef ASSERT
403 , _parse_idx(_idx)
404 #endif
405 {
406 debug_only( verify_construction() );
407 NOT_PRODUCT(nodes_created++);
408 assert( is_not_dead(n0), "can not use dead node");
409 assert( is_not_dead(n1), "can not use dead node");
410 assert( is_not_dead(n2), "can not use dead node");
411 assert( is_not_dead(n3), "can not use dead node");
412 assert( is_not_dead(n4), "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 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
418 }
419
420 //------------------------------Node-------------------------------------------
421 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
422 Node *n4, Node *n5)
423 : _idx(Init(6))
424 #ifdef ASSERT
425 , _parse_idx(_idx)
426 #endif
427 {
428 debug_only( verify_construction() );
429 NOT_PRODUCT(nodes_created++);
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 assert( is_not_dead(n5), "can not use dead node");
436 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
437 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
438 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
439 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
440 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
441 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
442 }
443
444 //------------------------------Node-------------------------------------------
445 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
446 Node *n4, Node *n5, Node *n6)
447 : _idx(Init(7))
448 #ifdef ASSERT
449 , _parse_idx(_idx)
450 #endif
451 {
452 debug_only( verify_construction() );
453 NOT_PRODUCT(nodes_created++);
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 assert( is_not_dead(n6), "can not use dead node");
461 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
462 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
463 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
464 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
465 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
466 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
467 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
468 }
469
470 #ifdef __clang__
471 #pragma clang diagnostic pop
472 #endif
473
474
475 //------------------------------clone------------------------------------------
476 // Clone a Node.
477 Node *Node::clone() const {
478 Compile* C = Compile::current();
479 uint s = size_of(); // Size of inherited Node
480 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
481 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
482 // Set the new input pointer array
483 n->_in = (Node**)(((char*)n)+s);
484 // Cannot share the old output pointer array, so kill it
485 n->_out = NO_OUT_ARRAY;
486 // And reset the counters to 0
487 n->_outcnt = 0;
488 n->_outmax = 0;
489 // Unlock this guy, since he is not in any hash table.
490 debug_only(n->_hash_lock = 0);
491 // Walk the old node's input list to duplicate its edges
492 uint i;
493 for( i = 0; i < len(); i++ ) {
494 Node *x = in(i);
495 n->_in[i] = x;
496 if (x != NULL) x->add_out(n);
497 }
498 if (is_macro())
499 C->add_macro_node(n);
500 if (is_expensive())
501 C->add_expensive_node(n);
502 // If the cloned node is a range check dependent CastII, add it to the list.
503 CastIINode* cast = n->isa_CastII();
504 if (cast != NULL && cast->has_range_check()) {
505 C->add_range_check_cast(cast);
506 }
507
508 n->set_idx(C->next_unique()); // Get new unique index as well
509 debug_only( n->verify_construction() );
510 NOT_PRODUCT(nodes_created++);
511 // Do not patch over the debug_idx of a clone, because it makes it
512 // impossible to break on the clone's moment of creation.
513 //debug_only( n->set_debug_idx( debug_idx() ) );
514
515 C->copy_node_notes_to(n, (Node*) this);
516
517 // MachNode clone
518 uint nopnds;
519 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
520 MachNode *mach = n->as_Mach();
521 MachNode *mthis = this->as_Mach();
522 // Get address of _opnd_array.
523 // It should be the same offset since it is the clone of this node.
524 MachOper **from = mthis->_opnds;
525 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
526 pointer_delta((const void*)from,
527 (const void*)(&mthis->_opnds), 1));
528 mach->_opnds = to;
529 for ( uint i = 0; i < nopnds; ++i ) {
530 to[i] = from[i]->clone();
531 }
532 }
533 // cloning CallNode may need to clone JVMState
534 if (n->is_Call()) {
535 n->as_Call()->clone_jvms(C);
536 }
537 if (n->is_SafePoint()) {
538 n->as_SafePoint()->clone_replaced_nodes();
539 }
540 return n; // Return the clone
541 }
542
543 //---------------------------setup_is_top--------------------------------------
544 // Call this when changing the top node, to reassert the invariants
545 // required by Node::is_top. See Compile::set_cached_top_node.
546 void Node::setup_is_top() {
547 if (this == (Node*)Compile::current()->top()) {
548 // This node has just become top. Kill its out array.
549 _outcnt = _outmax = 0;
550 _out = NULL; // marker value for top
551 assert(is_top(), "must be top");
552 } else {
553 if (_out == NULL) _out = NO_OUT_ARRAY;
554 assert(!is_top(), "must not be top");
555 }
556 }
557
558
559 //------------------------------~Node------------------------------------------
560 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
561 void Node::destruct() {
562 // Eagerly reclaim unique Node numberings
563 Compile* compile = Compile::current();
564 if ((uint)_idx+1 == compile->unique()) {
565 compile->set_unique(compile->unique()-1);
566 }
567 // Clear debug info:
568 Node_Notes* nn = compile->node_notes_at(_idx);
569 if (nn != NULL) nn->clear();
570 // Walk the input array, freeing the corresponding output edges
571 _cnt = _max; // forget req/prec distinction
572 uint i;
573 for( i = 0; i < _max; i++ ) {
574 set_req(i, NULL);
575 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
576 }
577 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
578 // See if the input array was allocated just prior to the object
579 int edge_size = _max*sizeof(void*);
580 int out_edge_size = _outmax*sizeof(void*);
581 char *edge_end = ((char*)_in) + edge_size;
582 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
583 int node_size = size_of();
584
585 // Free the output edge array
586 if (out_edge_size > 0) {
587 compile->node_arena()->Afree(out_array, out_edge_size);
588 }
589
590 // Free the input edge array and the node itself
591 if( edge_end == (char*)this ) {
592 // It was; free the input array and object all in one hit
593 #ifndef ASSERT
594 compile->node_arena()->Afree(_in,edge_size+node_size);
595 #endif
596 } else {
597 // Free just the input array
598 compile->node_arena()->Afree(_in,edge_size);
599
600 // Free just the object
601 #ifndef ASSERT
602 compile->node_arena()->Afree(this,node_size);
603 #endif
604 }
605 if (is_macro()) {
606 compile->remove_macro_node(this);
607 }
608 if (is_expensive()) {
609 compile->remove_expensive_node(this);
610 }
611 CastIINode* cast = isa_CastII();
612 if (cast != NULL && cast->has_range_check()) {
613 compile->remove_range_check_cast(cast);
614 }
615
616 if (is_SafePoint()) {
617 as_SafePoint()->delete_replaced_nodes();
618 }
619 #ifdef ASSERT
620 // We will not actually delete the storage, but we'll make the node unusable.
621 *(address*)this = badAddress; // smash the C++ vtbl, probably
622 _in = _out = (Node**) badAddress;
623 _max = _cnt = _outmax = _outcnt = 0;
624 compile->remove_modified_node(this);
625 #endif
626 }
627
628 //------------------------------grow-------------------------------------------
629 // Grow the input array, making space for more edges
630 void Node::grow( uint len ) {
631 Arena* arena = Compile::current()->node_arena();
632 uint new_max = _max;
633 if( new_max == 0 ) {
634 _max = 4;
635 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
636 Node** to = _in;
637 to[0] = NULL;
638 to[1] = NULL;
639 to[2] = NULL;
640 to[3] = NULL;
641 return;
642 }
643 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
644 // Trimming to limit allows a uint8 to handle up to 255 edges.
645 // Previously I was using only powers-of-2 which peaked at 128 edges.
646 //if( new_max >= limit ) new_max = limit-1;
647 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
648 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
649 _max = new_max; // Record new max length
650 // This assertion makes sure that Node::_max is wide enough to
651 // represent the numerical value of new_max.
652 assert(_max == new_max && _max > len, "int width of _max is too small");
653 }
654
655 //-----------------------------out_grow----------------------------------------
656 // Grow the input array, making space for more edges
657 void Node::out_grow( uint len ) {
658 assert(!is_top(), "cannot grow a top node's out array");
659 Arena* arena = Compile::current()->node_arena();
660 uint new_max = _outmax;
661 if( new_max == 0 ) {
662 _outmax = 4;
663 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
664 return;
665 }
666 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
667 // Trimming to limit allows a uint8 to handle up to 255 edges.
668 // Previously I was using only powers-of-2 which peaked at 128 edges.
669 //if( new_max >= limit ) new_max = limit-1;
670 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
671 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
672 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
673 _outmax = new_max; // Record new max length
674 // This assertion makes sure that Node::_max is wide enough to
675 // represent the numerical value of new_max.
676 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
677 }
678
679 #ifdef ASSERT
680 //------------------------------is_dead----------------------------------------
681 bool Node::is_dead() const {
682 // Mach and pinch point nodes may look like dead.
683 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
684 return false;
685 for( uint i = 0; i < _max; i++ )
686 if( _in[i] != NULL )
687 return false;
688 dump();
689 return true;
690 }
691 #endif
692
693
694 //------------------------------is_unreachable---------------------------------
695 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
696 assert(!is_Mach(), "doesn't work with MachNodes");
697 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
698 }
699
700 //------------------------------add_req----------------------------------------
701 // Add a new required input at the end
702 void Node::add_req( Node *n ) {
703 assert( is_not_dead(n), "can not use dead node");
704
705 // Look to see if I can move precedence down one without reallocating
706 if( (_cnt >= _max) || (in(_max-1) != NULL) )
707 grow( _max+1 );
708
709 // Find a precedence edge to move
710 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
711 uint i;
712 for( i=_cnt; i<_max; i++ )
713 if( in(i) == NULL ) // Find the NULL at end of prec edge list
714 break; // There must be one, since we grew the array
715 _in[i] = in(_cnt); // Move prec over, making space for req edge
716 }
717 _in[_cnt++] = n; // Stuff over old prec edge
718 if (n != NULL) n->add_out((Node *)this);
719 }
720
721 //---------------------------add_req_batch-------------------------------------
722 // Add a new required input at the end
723 void Node::add_req_batch( Node *n, uint m ) {
724 assert( is_not_dead(n), "can not use dead node");
725 // check various edge cases
726 if ((int)m <= 1) {
727 assert((int)m >= 0, "oob");
728 if (m != 0) add_req(n);
729 return;
730 }
731
732 // Look to see if I can move precedence down one without reallocating
733 if( (_cnt+m) > _max || _in[_max-m] )
734 grow( _max+m );
735
736 // Find a precedence edge to move
737 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
738 uint i;
739 for( i=_cnt; i<_max; i++ )
740 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
741 break; // There must be one, since we grew the array
742 // Slide all the precs over by m positions (assume #prec << m).
743 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
744 }
745
746 // Stuff over the old prec edges
747 for(uint i=0; i<m; i++ ) {
748 _in[_cnt++] = n;
749 }
750
751 // Insert multiple out edges on the node.
752 if (n != NULL && !n->is_top()) {
753 for(uint i=0; i<m; i++ ) {
754 n->add_out((Node *)this);
755 }
756 }
757 }
758
759 //------------------------------del_req----------------------------------------
760 // Delete the required edge and compact the edge array
761 void Node::del_req( uint idx ) {
762 assert( idx < _cnt, "oob");
763 assert( !VerifyHashTableKeys || _hash_lock == 0,
764 "remove node from hash table before modifying it");
765 // First remove corresponding def-use edge
766 Node *n = in(idx);
767 if (n != NULL) n->del_out((Node *)this);
768 _in[idx] = in(--_cnt); // Compact the array
769 // Avoid spec violation: Gap in prec edges.
770 close_prec_gap_at(_cnt);
771 Compile::current()->record_modified_node(this);
772 }
773
774 //------------------------------del_req_ordered--------------------------------
775 // Delete the required edge and compact the edge array with preserved order
776 void Node::del_req_ordered( uint idx ) {
777 assert( idx < _cnt, "oob");
778 assert( !VerifyHashTableKeys || _hash_lock == 0,
779 "remove node from hash table before modifying it");
780 // First remove corresponding def-use edge
781 Node *n = in(idx);
782 if (n != NULL) n->del_out((Node *)this);
783 if (idx < --_cnt) { // Not last edge ?
784 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
785 }
786 // Avoid spec violation: Gap in prec edges.
787 close_prec_gap_at(_cnt);
788 Compile::current()->record_modified_node(this);
789 }
790
791 //------------------------------ins_req----------------------------------------
792 // Insert a new required input at the end
793 void Node::ins_req( uint idx, Node *n ) {
794 assert( is_not_dead(n), "can not use dead node");
795 add_req(NULL); // Make space
796 assert( idx < _max, "Must have allocated enough space");
797 // Slide over
798 if(_cnt-idx-1 > 0) {
799 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
800 }
801 _in[idx] = n; // Stuff over old required edge
802 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
803 }
804
805 //-----------------------------find_edge---------------------------------------
806 int Node::find_edge(Node* n) {
807 for (uint i = 0; i < len(); i++) {
808 if (_in[i] == n) return i;
809 }
810 return -1;
811 }
812
813 //----------------------------replace_edge-------------------------------------
814 int Node::replace_edge(Node* old, Node* neww) {
815 if (old == neww) return 0; // nothing to do
816 uint nrep = 0;
817 for (uint i = 0; i < len(); i++) {
818 if (in(i) == old) {
819 if (i < req()) {
820 set_req(i, neww);
821 } else {
822 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
823 set_prec(i, neww);
824 }
825 nrep++;
826 }
827 }
828 return nrep;
829 }
830
831 /**
832 * Replace input edges in the range pointing to 'old' node.
833 */
834 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
835 if (old == neww) return 0; // nothing to do
836 uint nrep = 0;
837 for (int i = start; i < end; i++) {
838 if (in(i) == old) {
839 set_req(i, neww);
840 nrep++;
841 }
842 }
843 return nrep;
844 }
845
846 //-------------------------disconnect_inputs-----------------------------------
847 // NULL out all inputs to eliminate incoming Def-Use edges.
848 // Return the number of edges between 'n' and 'this'
849 int Node::disconnect_inputs(Node *n, Compile* C) {
850 int edges_to_n = 0;
851
852 uint cnt = req();
853 for( uint i = 0; i < cnt; ++i ) {
854 if( in(i) == 0 ) continue;
855 if( in(i) == n ) ++edges_to_n;
856 set_req(i, NULL);
857 }
858 // Remove precedence edges if any exist
859 // Note: Safepoints may have precedence edges, even during parsing
860 if( (req() != len()) && (in(req()) != NULL) ) {
861 uint max = len();
862 for( uint i = 0; i < max; ++i ) {
863 if( in(i) == 0 ) continue;
864 if( in(i) == n ) ++edges_to_n;
865 set_prec(i, NULL);
866 }
867 }
868
869 // Node::destruct requires all out edges be deleted first
870 // debug_only(destruct();) // no reuse benefit expected
871 if (edges_to_n == 0) {
872 C->record_dead_node(_idx);
873 }
874 return edges_to_n;
875 }
876
877 //-----------------------------uncast---------------------------------------
878 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
879 // Strip away casting. (It is depth-limited.)
880 Node* Node::uncast() const {
881 // Should be inline:
882 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
883 if (is_ConstraintCast())
884 return uncast_helper(this);
885 else
886 return (Node*) this;
887 }
888
889 // Find out of current node that matches opcode.
890 Node* Node::find_out_with(int opcode) {
891 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
892 Node* use = fast_out(i);
893 if (use->Opcode() == opcode) {
894 return use;
895 }
896 }
897 return NULL;
898 }
899
900 // Return true if the current node has an out that matches opcode.
901 bool Node::has_out_with(int opcode) {
902 return (find_out_with(opcode) != NULL);
903 }
904
905 // Return true if the current node has an out that matches any of the opcodes.
906 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
907 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
908 int opcode = fast_out(i)->Opcode();
909 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
910 return true;
911 }
912 }
913 return false;
914 }
915
916
917 //---------------------------uncast_helper-------------------------------------
918 Node* Node::uncast_helper(const Node* p) {
919 #ifdef ASSERT
920 uint depth_count = 0;
921 const Node* orig_p = p;
922 #endif
923
924 while (true) {
925 #ifdef ASSERT
926 if (depth_count >= K) {
927 orig_p->dump(4);
928 if (p != orig_p)
929 p->dump(1);
930 }
931 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
932 #endif
933 if (p == NULL || p->req() != 2) {
934 break;
935 } else if (p->is_ConstraintCast()) {
936 p = p->in(1);
937 } else {
938 break;
939 }
940 }
941 return (Node*) p;
942 }
943
944 //------------------------------add_prec---------------------------------------
945 // Add a new precedence input. Precedence inputs are unordered, with
946 // duplicates removed and NULLs packed down at the end.
947 void Node::add_prec( Node *n ) {
948 assert( is_not_dead(n), "can not use dead node");
949
950 // Check for NULL at end
951 if( _cnt >= _max || in(_max-1) )
952 grow( _max+1 );
953
954 // Find a precedence edge to move
955 uint i = _cnt;
956 while( in(i) != NULL ) {
957 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
958 i++;
959 }
960 _in[i] = n; // Stuff prec edge over NULL
961 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
962
963 #ifdef ASSERT
964 while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
965 #endif
966 }
967
968 //------------------------------rm_prec----------------------------------------
969 // Remove a precedence input. Precedence inputs are unordered, with
970 // duplicates removed and NULLs packed down at the end.
971 void Node::rm_prec( uint j ) {
972 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
973 assert(j >= _cnt, "not a precedence edge");
974 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
975 _in[j]->del_out((Node *)this);
976 close_prec_gap_at(j);
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(PhaseGVN* phase) {
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(PhaseGVN* phase) 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 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 LShiftINode(in(1),phase->intcon(5)));
1096 // return new 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 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 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1130 // See IfProjNode::Identity()
1131 return true;
1132 }
1133 return false;
1134 };
1135
1136 //--------------------------find_exact_control---------------------------------
1137 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1138 Node* Node::find_exact_control(Node* ctrl) {
1139 if (ctrl == NULL && this->is_Region())
1140 ctrl = this->as_Region()->is_copy();
1141
1142 if (ctrl != NULL && ctrl->is_CatchProj()) {
1143 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1144 ctrl = ctrl->in(0);
1145 if (ctrl != NULL && !ctrl->is_top())
1146 ctrl = ctrl->in(0);
1147 }
1148
1149 if (ctrl != NULL && ctrl->is_Proj())
1150 ctrl = ctrl->in(0);
1151
1152 return ctrl;
1153 }
1154
1155 //--------------------------dominates------------------------------------------
1156 // Helper function for MemNode::all_controls_dominate().
1157 // Check if 'this' control node dominates or equal to 'sub' control node.
1158 // We already know that if any path back to Root or Start reaches 'this',
1159 // then all paths so, so this is a simple search for one example,
1160 // not an exhaustive search for a counterexample.
1161 bool Node::dominates(Node* sub, Node_List &nlist) {
1162 assert(this->is_CFG(), "expecting control");
1163 assert(sub != NULL && sub->is_CFG(), "expecting control");
1164
1165 // detect dead cycle without regions
1166 int iterations_without_region_limit = DominatorSearchLimit;
1167
1168 Node* orig_sub = sub;
1169 Node* dom = this;
1170 bool met_dom = false;
1171 nlist.clear();
1172
1173 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1174 // After seeing 'dom', continue up to Root or Start.
1175 // If we hit a region (backward split point), it may be a loop head.
1176 // Keep going through one of the region's inputs. If we reach the
1177 // same region again, go through a different input. Eventually we
1178 // will either exit through the loop head, or give up.
1179 // (If we get confused, break out and return a conservative 'false'.)
1180 while (sub != NULL) {
1181 if (sub->is_top()) break; // Conservative answer for dead code.
1182 if (sub == dom) {
1183 if (nlist.size() == 0) {
1184 // No Region nodes except loops were visited before and the EntryControl
1185 // path was taken for loops: it did not walk in a cycle.
1186 return true;
1187 } else if (met_dom) {
1188 break; // already met before: walk in a cycle
1189 } else {
1190 // Region nodes were visited. Continue walk up to Start or Root
1191 // to make sure that it did not walk in a cycle.
1192 met_dom = true; // first time meet
1193 iterations_without_region_limit = DominatorSearchLimit; // Reset
1194 }
1195 }
1196 if (sub->is_Start() || sub->is_Root()) {
1197 // Success if we met 'dom' along a path to Start or Root.
1198 // We assume there are no alternative paths that avoid 'dom'.
1199 // (This assumption is up to the caller to ensure!)
1200 return met_dom;
1201 }
1202 Node* up = sub->in(0);
1203 // Normalize simple pass-through regions and projections:
1204 up = sub->find_exact_control(up);
1205 // If sub == up, we found a self-loop. Try to push past it.
1206 if (sub == up && sub->is_Loop()) {
1207 // Take loop entry path on the way up to 'dom'.
1208 up = sub->in(1); // in(LoopNode::EntryControl);
1209 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1210 // Always take in(1) path on the way up to 'dom' for clone regions
1211 // (with only one input) or regions which merge > 2 paths
1212 // (usually used to merge fast/slow paths).
1213 up = sub->in(1);
1214 } else if (sub == up && sub->is_Region()) {
1215 // Try both paths for Regions with 2 input paths (it may be a loop head).
1216 // It could give conservative 'false' answer without information
1217 // which region's input is the entry path.
1218 iterations_without_region_limit = DominatorSearchLimit; // Reset
1219
1220 bool region_was_visited_before = false;
1221 // Was this Region node visited before?
1222 // If so, we have reached it because we accidentally took a
1223 // loop-back edge from 'sub' back into the body of the loop,
1224 // and worked our way up again to the loop header 'sub'.
1225 // So, take the first unexplored path on the way up to 'dom'.
1226 for (int j = nlist.size() - 1; j >= 0; j--) {
1227 intptr_t ni = (intptr_t)nlist.at(j);
1228 Node* visited = (Node*)(ni & ~1);
1229 bool visited_twice_already = ((ni & 1) != 0);
1230 if (visited == sub) {
1231 if (visited_twice_already) {
1232 // Visited 2 paths, but still stuck in loop body. Give up.
1233 return false;
1234 }
1235 // The Region node was visited before only once.
1236 // (We will repush with the low bit set, below.)
1237 nlist.remove(j);
1238 // We will find a new edge and re-insert.
1239 region_was_visited_before = true;
1240 break;
1241 }
1242 }
1243
1244 // Find an incoming edge which has not been seen yet; walk through it.
1245 assert(up == sub, "");
1246 uint skip = region_was_visited_before ? 1 : 0;
1247 for (uint i = 1; i < sub->req(); i++) {
1248 Node* in = sub->in(i);
1249 if (in != NULL && !in->is_top() && in != sub) {
1250 if (skip == 0) {
1251 up = in;
1252 break;
1253 }
1254 --skip; // skip this nontrivial input
1255 }
1256 }
1257
1258 // Set 0 bit to indicate that both paths were taken.
1259 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1260 }
1261
1262 if (up == sub) {
1263 break; // some kind of tight cycle
1264 }
1265 if (up == orig_sub && met_dom) {
1266 // returned back after visiting 'dom'
1267 break; // some kind of cycle
1268 }
1269 if (--iterations_without_region_limit < 0) {
1270 break; // dead cycle
1271 }
1272 sub = up;
1273 }
1274
1275 // Did not meet Root or Start node in pred. chain.
1276 // Conservative answer for dead code.
1277 return false;
1278 }
1279
1280 //------------------------------remove_dead_region-----------------------------
1281 // This control node is dead. Follow the subgraph below it making everything
1282 // using it dead as well. This will happen normally via the usual IterGVN
1283 // worklist but this call is more efficient. Do not update use-def info
1284 // inside the dead region, just at the borders.
1285 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1286 // Con's are a popular node to re-hit in the hash table again.
1287 if( dead->is_Con() ) return;
1288
1289 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1290 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1291 Node_List nstack(Thread::current()->resource_area());
1292
1293 Node *top = igvn->C->top();
1294 nstack.push(dead);
1295 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1296
1297 while (nstack.size() > 0) {
1298 dead = nstack.pop();
1299 if (dead->outcnt() > 0) {
1300 // Keep dead node on stack until all uses are processed.
1301 nstack.push(dead);
1302 // For all Users of the Dead... ;-)
1303 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1304 Node* use = dead->last_out(k);
1305 igvn->hash_delete(use); // Yank from hash table prior to mod
1306 if (use->in(0) == dead) { // Found another dead node
1307 assert (!use->is_Con(), "Control for Con node should be Root node.");
1308 use->set_req(0, top); // Cut dead edge to prevent processing
1309 nstack.push(use); // the dead node again.
1310 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1311 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1312 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1313 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1314 use->set_req(0, top); // Cut self edge
1315 nstack.push(use);
1316 } else { // Else found a not-dead user
1317 // Dead if all inputs are top or null
1318 bool dead_use = !use->is_Root(); // Keep empty graph alive
1319 for (uint j = 1; j < use->req(); j++) {
1320 Node* in = use->in(j);
1321 if (in == dead) { // Turn all dead inputs into TOP
1322 use->set_req(j, top);
1323 } else if (in != NULL && !in->is_top()) {
1324 dead_use = false;
1325 }
1326 }
1327 if (dead_use) {
1328 if (use->is_Region()) {
1329 use->set_req(0, top); // Cut self edge
1330 }
1331 nstack.push(use);
1332 } else {
1333 igvn->_worklist.push(use);
1334 }
1335 }
1336 // Refresh the iterator, since any number of kills might have happened.
1337 k = dead->last_outs(kmin);
1338 }
1339 } else { // (dead->outcnt() == 0)
1340 // Done with outputs.
1341 igvn->hash_delete(dead);
1342 igvn->_worklist.remove(dead);
1343 igvn->C->remove_modified_node(dead);
1344 igvn->set_type(dead, Type::TOP);
1345 if (dead->is_macro()) {
1346 igvn->C->remove_macro_node(dead);
1347 }
1348 if (dead->is_expensive()) {
1349 igvn->C->remove_expensive_node(dead);
1350 }
1351 CastIINode* cast = dead->isa_CastII();
1352 if (cast != NULL && cast->has_range_check()) {
1353 igvn->C->remove_range_check_cast(cast);
1354 }
1355 igvn->C->record_dead_node(dead->_idx);
1356 // Kill all inputs to the dead guy
1357 for (uint i=0; i < dead->req(); i++) {
1358 Node *n = dead->in(i); // Get input to dead guy
1359 if (n != NULL && !n->is_top()) { // Input is valid?
1360 dead->set_req(i, top); // Smash input away
1361 if (n->outcnt() == 0) { // Input also goes dead?
1362 if (!n->is_Con())
1363 nstack.push(n); // Clear it out as well
1364 } else if (n->outcnt() == 1 &&
1365 n->has_special_unique_user()) {
1366 igvn->add_users_to_worklist( n );
1367 } else if (n->outcnt() <= 2 && n->is_Store()) {
1368 // Push store's uses on worklist to enable folding optimization for
1369 // store/store and store/load to the same address.
1370 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1371 // and remove_globally_dead_node().
1372 igvn->add_users_to_worklist( n );
1373 }
1374 }
1375 }
1376 } // (dead->outcnt() == 0)
1377 } // while (nstack.size() > 0) for outputs
1378 return;
1379 }
1380
1381 //------------------------------remove_dead_region-----------------------------
1382 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1383 Node *n = in(0);
1384 if( !n ) return false;
1385 // Lost control into this guy? I.e., it became unreachable?
1386 // Aggressively kill all unreachable code.
1387 if (can_reshape && n->is_top()) {
1388 kill_dead_code(this, phase->is_IterGVN());
1389 return false; // Node is dead.
1390 }
1391
1392 if( n->is_Region() && n->as_Region()->is_copy() ) {
1393 Node *m = n->nonnull_req();
1394 set_req(0, m);
1395 return true;
1396 }
1397 return false;
1398 }
1399
1400 //------------------------------hash-------------------------------------------
1401 // Hash function over Nodes.
1402 uint Node::hash() const {
1403 uint sum = 0;
1404 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1405 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1406 return (sum>>2) + _cnt + Opcode();
1407 }
1408
1409 //------------------------------cmp--------------------------------------------
1410 // Compare special parts of simple Nodes
1411 uint Node::cmp( const Node &n ) const {
1412 return 1; // Must be same
1413 }
1414
1415 //------------------------------rematerialize-----------------------------------
1416 // Should we clone rather than spill this instruction?
1417 bool Node::rematerialize() const {
1418 if ( is_Mach() )
1419 return this->as_Mach()->rematerialize();
1420 else
1421 return (_flags & Flag_rematerialize) != 0;
1422 }
1423
1424 //------------------------------needs_anti_dependence_check---------------------
1425 // Nodes which use memory without consuming it, hence need antidependences.
1426 bool Node::needs_anti_dependence_check() const {
1427 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1428 return false;
1429 else
1430 return in(1)->bottom_type()->has_memory();
1431 }
1432
1433
1434 // Get an integer constant from a ConNode (or CastIINode).
1435 // Return a default value if there is no apparent constant here.
1436 const TypeInt* Node::find_int_type() const {
1437 if (this->is_Type()) {
1438 return this->as_Type()->type()->isa_int();
1439 } else if (this->is_Con()) {
1440 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1441 return this->bottom_type()->isa_int();
1442 }
1443 return NULL;
1444 }
1445
1446 // Get a pointer constant from a ConstNode.
1447 // Returns the constant if it is a pointer ConstNode
1448 intptr_t Node::get_ptr() const {
1449 assert( Opcode() == Op_ConP, "" );
1450 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1451 }
1452
1453 // Get a narrow oop constant from a ConNNode.
1454 intptr_t Node::get_narrowcon() const {
1455 assert( Opcode() == Op_ConN, "" );
1456 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1457 }
1458
1459 // Get a long constant from a ConNode.
1460 // Return a default value if there is no apparent constant here.
1461 const TypeLong* Node::find_long_type() const {
1462 if (this->is_Type()) {
1463 return this->as_Type()->type()->isa_long();
1464 } else if (this->is_Con()) {
1465 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1466 return this->bottom_type()->isa_long();
1467 }
1468 return NULL;
1469 }
1470
1471
1472 /**
1473 * Return a ptr type for nodes which should have it.
1474 */
1475 const TypePtr* Node::get_ptr_type() const {
1476 const TypePtr* tp = this->bottom_type()->make_ptr();
1477 #ifdef ASSERT
1478 if (tp == NULL) {
1479 this->dump(1);
1480 assert((tp != NULL), "unexpected node type");
1481 }
1482 #endif
1483 return tp;
1484 }
1485
1486 // Get a double constant from a ConstNode.
1487 // Returns the constant if it is a double ConstNode
1488 jdouble Node::getd() const {
1489 assert( Opcode() == Op_ConD, "" );
1490 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1491 }
1492
1493 // Get a float constant from a ConstNode.
1494 // Returns the constant if it is a float ConstNode
1495 jfloat Node::getf() const {
1496 assert( Opcode() == Op_ConF, "" );
1497 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1498 }
1499
1500 #ifndef PRODUCT
1501
1502 //------------------------------find------------------------------------------
1503 // Find a neighbor of this Node with the given _idx
1504 // If idx is negative, find its absolute value, following both _in and _out.
1505 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1506 VectorSet* old_space, VectorSet* new_space ) {
1507 int node_idx = (idx >= 0) ? idx : -idx;
1508 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1509 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1510 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1511 if( v->test(n->_idx) ) return;
1512 if( (int)n->_idx == node_idx
1513 debug_only(|| n->debug_idx() == node_idx) ) {
1514 if (result != NULL)
1515 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1516 (uintptr_t)result, (uintptr_t)n, node_idx);
1517 result = n;
1518 }
1519 v->set(n->_idx);
1520 for( uint i=0; i<n->len(); i++ ) {
1521 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1522 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1523 }
1524 // Search along forward edges also:
1525 if (idx < 0 && !only_ctrl) {
1526 for( uint j=0; j<n->outcnt(); j++ ) {
1527 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1528 }
1529 }
1530 #ifdef ASSERT
1531 // Search along debug_orig edges last, checking for cycles
1532 Node* orig = n->debug_orig();
1533 if (orig != NULL) {
1534 do {
1535 if (NotANode(orig)) break;
1536 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1537 orig = orig->debug_orig();
1538 } while (orig != NULL && orig != n->debug_orig());
1539 }
1540 #endif //ASSERT
1541 }
1542
1543 // call this from debugger:
1544 Node* find_node(Node* n, int idx) {
1545 return n->find(idx);
1546 }
1547
1548 //------------------------------find-------------------------------------------
1549 Node* Node::find(int idx) const {
1550 ResourceArea *area = Thread::current()->resource_area();
1551 VectorSet old_space(area), new_space(area);
1552 Node* result = NULL;
1553 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1554 return result;
1555 }
1556
1557 //------------------------------find_ctrl--------------------------------------
1558 // Find an ancestor to this node in the control history with given _idx
1559 Node* Node::find_ctrl(int idx) const {
1560 ResourceArea *area = Thread::current()->resource_area();
1561 VectorSet old_space(area), new_space(area);
1562 Node* result = NULL;
1563 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1564 return result;
1565 }
1566 #endif
1567
1568
1569
1570 #ifndef PRODUCT
1571
1572 // -----------------------------Name-------------------------------------------
1573 extern const char *NodeClassNames[];
1574 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1575
1576 static bool is_disconnected(const Node* n) {
1577 for (uint i = 0; i < n->req(); i++) {
1578 if (n->in(i) != NULL) return false;
1579 }
1580 return true;
1581 }
1582
1583 #ifdef ASSERT
1584 static void dump_orig(Node* orig, outputStream *st) {
1585 Compile* C = Compile::current();
1586 if (NotANode(orig)) orig = NULL;
1587 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1588 if (orig == NULL) return;
1589 st->print(" !orig=");
1590 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1591 if (NotANode(fast)) fast = NULL;
1592 while (orig != NULL) {
1593 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1594 if (discon) st->print("[");
1595 if (!Compile::current()->node_arena()->contains(orig))
1596 st->print("o");
1597 st->print("%d", orig->_idx);
1598 if (discon) st->print("]");
1599 orig = orig->debug_orig();
1600 if (NotANode(orig)) orig = NULL;
1601 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1602 if (orig != NULL) st->print(",");
1603 if (fast != NULL) {
1604 // Step fast twice for each single step of orig:
1605 fast = fast->debug_orig();
1606 if (NotANode(fast)) fast = NULL;
1607 if (fast != NULL && fast != orig) {
1608 fast = fast->debug_orig();
1609 if (NotANode(fast)) fast = NULL;
1610 }
1611 if (fast == orig) {
1612 st->print("...");
1613 break;
1614 }
1615 }
1616 }
1617 }
1618
1619 void Node::set_debug_orig(Node* orig) {
1620 _debug_orig = orig;
1621 if (BreakAtNode == 0) return;
1622 if (NotANode(orig)) orig = NULL;
1623 int trip = 10;
1624 while (orig != NULL) {
1625 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1626 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1627 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1628 BREAKPOINT;
1629 }
1630 orig = orig->debug_orig();
1631 if (NotANode(orig)) orig = NULL;
1632 if (trip-- <= 0) break;
1633 }
1634 }
1635 #endif //ASSERT
1636
1637 //------------------------------dump------------------------------------------
1638 // Dump a Node
1639 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1640 Compile* C = Compile::current();
1641 bool is_new = C->node_arena()->contains(this);
1642 C->_in_dump_cnt++;
1643 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1644
1645 // Dump the required and precedence inputs
1646 dump_req(st);
1647 dump_prec(st);
1648 // Dump the outputs
1649 dump_out(st);
1650
1651 if (is_disconnected(this)) {
1652 #ifdef ASSERT
1653 st->print(" [%d]",debug_idx());
1654 dump_orig(debug_orig(), st);
1655 #endif
1656 st->cr();
1657 C->_in_dump_cnt--;
1658 return; // don't process dead nodes
1659 }
1660
1661 if (C->clone_map().value(_idx) != 0) {
1662 C->clone_map().dump(_idx);
1663 }
1664 // Dump node-specific info
1665 dump_spec(st);
1666 #ifdef ASSERT
1667 // Dump the non-reset _debug_idx
1668 if (Verbose && WizardMode) {
1669 st->print(" [%d]",debug_idx());
1670 }
1671 #endif
1672
1673 const Type *t = bottom_type();
1674
1675 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1676 const TypeInstPtr *toop = t->isa_instptr();
1677 const TypeKlassPtr *tkls = t->isa_klassptr();
1678 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1679 if (klass && klass->is_loaded() && klass->is_interface()) {
1680 st->print(" Interface:");
1681 } else if (toop) {
1682 st->print(" Oop:");
1683 } else if (tkls) {
1684 st->print(" Klass:");
1685 }
1686 t->dump_on(st);
1687 } else if (t == Type::MEMORY) {
1688 st->print(" Memory:");
1689 MemNode::dump_adr_type(this, adr_type(), st);
1690 } else if (Verbose || WizardMode) {
1691 st->print(" Type:");
1692 if (t) {
1693 t->dump_on(st);
1694 } else {
1695 st->print("no type");
1696 }
1697 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1698 // Dump MachSpillcopy vector type.
1699 t->dump_on(st);
1700 }
1701 if (is_new) {
1702 debug_only(dump_orig(debug_orig(), st));
1703 Node_Notes* nn = C->node_notes_at(_idx);
1704 if (nn != NULL && !nn->is_clear()) {
1705 if (nn->jvms() != NULL) {
1706 st->print(" !jvms:");
1707 nn->jvms()->dump_spec(st);
1708 }
1709 }
1710 }
1711 if (suffix) st->print("%s", suffix);
1712 C->_in_dump_cnt--;
1713 }
1714
1715 //------------------------------dump_req--------------------------------------
1716 void Node::dump_req(outputStream *st) const {
1717 // Dump the required input edges
1718 for (uint i = 0; i < req(); i++) { // For all required inputs
1719 Node* d = in(i);
1720 if (d == NULL) {
1721 st->print("_ ");
1722 } else if (NotANode(d)) {
1723 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1724 } else {
1725 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1726 }
1727 }
1728 }
1729
1730
1731 //------------------------------dump_prec-------------------------------------
1732 void Node::dump_prec(outputStream *st) const {
1733 // Dump the precedence edges
1734 int any_prec = 0;
1735 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1736 Node* p = in(i);
1737 if (p != NULL) {
1738 if (!any_prec++) st->print(" |");
1739 if (NotANode(p)) { st->print("NotANode "); continue; }
1740 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1741 }
1742 }
1743 }
1744
1745 //------------------------------dump_out--------------------------------------
1746 void Node::dump_out(outputStream *st) const {
1747 // Delimit the output edges
1748 st->print(" [[");
1749 // Dump the output edges
1750 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1751 Node* u = _out[i];
1752 if (u == NULL) {
1753 st->print("_ ");
1754 } else if (NotANode(u)) {
1755 st->print("NotANode ");
1756 } else {
1757 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1758 }
1759 }
1760 st->print("]] ");
1761 }
1762
1763 //----------------------------collect_nodes_i----------------------------------
1764 // Collects nodes from an Ideal graph, starting from a given start node and
1765 // moving in a given direction until a certain depth (distance from the start
1766 // node) is reached. Duplicates are ignored.
1767 // Arguments:
1768 // nstack: the nodes are collected into this array.
1769 // start: the node at which to start collecting.
1770 // direction: if this is a positive number, collect input nodes; if it is
1771 // a negative number, collect output nodes.
1772 // depth: collect nodes up to this distance from the start node.
1773 // include_start: whether to include the start node in the result collection.
1774 // only_ctrl: whether to regard control edges only during traversal.
1775 // only_data: whether to regard data edges only during traversal.
1776 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1777 Node* s = (Node*) start; // remove const
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 if (only_data && n->is_CFG()) continue;
1794
1795 bool on_stack = nstack->contains(n);
1796 if (!on_stack) {
1797 nstack->append(n);
1798 }
1799 }
1800 }
1801 begin = end;
1802 }
1803 if (!include_start) {
1804 nstack->remove(s);
1805 }
1806 }
1807
1808 //------------------------------dump_nodes-------------------------------------
1809 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1810 if (NotANode(start)) return;
1811
1812 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1813 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1814
1815 int end = nstack.length();
1816 if (d > 0) {
1817 for(int j = end-1; j >= 0; j--) {
1818 nstack.at(j)->dump();
1819 }
1820 } else {
1821 for(int j = 0; j < end; j++) {
1822 nstack.at(j)->dump();
1823 }
1824 }
1825 }
1826
1827 //------------------------------dump-------------------------------------------
1828 void Node::dump(int d) const {
1829 dump_nodes(this, d, false);
1830 }
1831
1832 //------------------------------dump_ctrl--------------------------------------
1833 // Dump a Node's control history to depth
1834 void Node::dump_ctrl(int d) const {
1835 dump_nodes(this, d, true);
1836 }
1837
1838 //-----------------------------dump_compact------------------------------------
1839 void Node::dump_comp() const {
1840 this->dump_comp("\n");
1841 }
1842
1843 //-----------------------------dump_compact------------------------------------
1844 // Dump a Node in compact representation, i.e., just print its name and index.
1845 // Nodes can specify additional specifics to print in compact representation by
1846 // implementing dump_compact_spec.
1847 void Node::dump_comp(const char* suffix, outputStream *st) const {
1848 Compile* C = Compile::current();
1849 C->_in_dump_cnt++;
1850 st->print("%s(%d)", Name(), _idx);
1851 this->dump_compact_spec(st);
1852 if (suffix) {
1853 st->print("%s", suffix);
1854 }
1855 C->_in_dump_cnt--;
1856 }
1857
1858 //----------------------------dump_related-------------------------------------
1859 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1860 // hand and is determined by the implementation of the virtual method rel.
1861 void Node::dump_related() const {
1862 Compile* C = Compile::current();
1863 GrowableArray <Node *> in_rel(C->unique());
1864 GrowableArray <Node *> out_rel(C->unique());
1865 this->related(&in_rel, &out_rel, false);
1866 for (int i = in_rel.length() - 1; i >= 0; i--) {
1867 in_rel.at(i)->dump();
1868 }
1869 this->dump("\n", true);
1870 for (int i = 0; i < out_rel.length(); i++) {
1871 out_rel.at(i)->dump();
1872 }
1873 }
1874
1875 //----------------------------dump_related-------------------------------------
1876 // Dump a Node's related nodes up to a given depth (distance from the start
1877 // node).
1878 // Arguments:
1879 // d_in: depth for input nodes.
1880 // d_out: depth for output nodes (note: this also is a positive number).
1881 void Node::dump_related(uint d_in, uint d_out) const {
1882 Compile* C = Compile::current();
1883 GrowableArray <Node *> in_rel(C->unique());
1884 GrowableArray <Node *> out_rel(C->unique());
1885
1886 // call collect_nodes_i directly
1887 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1888 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1889
1890 for (int i = in_rel.length() - 1; i >= 0; i--) {
1891 in_rel.at(i)->dump();
1892 }
1893 this->dump("\n", true);
1894 for (int i = 0; i < out_rel.length(); i++) {
1895 out_rel.at(i)->dump();
1896 }
1897 }
1898
1899 //------------------------dump_related_compact---------------------------------
1900 // Dump a Node's related nodes in compact representation. The notion of
1901 // "related" depends on the Node at hand and is determined by the implementation
1902 // of the virtual method rel.
1903 void Node::dump_related_compact() const {
1904 Compile* C = Compile::current();
1905 GrowableArray <Node *> in_rel(C->unique());
1906 GrowableArray <Node *> out_rel(C->unique());
1907 this->related(&in_rel, &out_rel, true);
1908 int n_in = in_rel.length();
1909 int n_out = out_rel.length();
1910
1911 this->dump_comp(n_in == 0 ? "\n" : " ");
1912 for (int i = 0; i < n_in; i++) {
1913 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1914 }
1915 for (int i = 0; i < n_out; i++) {
1916 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1917 }
1918 }
1919
1920 //------------------------------related----------------------------------------
1921 // Collect a Node's related nodes. The default behaviour just collects the
1922 // inputs and outputs at depth 1, including both control and data flow edges,
1923 // regardless of whether the presentation is compact or not. For data nodes,
1924 // the default is to collect all data inputs (till level 1 if compact), and
1925 // outputs till level 1.
1926 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1927 if (this->is_CFG()) {
1928 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1929 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1930 } else {
1931 if (compact) {
1932 this->collect_nodes(in_rel, 1, false, true);
1933 } else {
1934 this->collect_nodes_in_all_data(in_rel, false);
1935 }
1936 this->collect_nodes(out_rel, -1, false, false);
1937 }
1938 }
1939
1940 //---------------------------collect_nodes-------------------------------------
1941 // An entry point to the low-level node collection facility, to start from a
1942 // given node in the graph. The start node is by default not included in the
1943 // result.
1944 // Arguments:
1945 // ns: collect the nodes into this data structure.
1946 // d: the depth (distance from start node) to which nodes should be
1947 // collected. A value >0 indicates input nodes, a value <0, output
1948 // nodes.
1949 // ctrl: include only control nodes.
1950 // data: include only data nodes.
1951 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
1952 if (ctrl && data) {
1953 // ignore nonsensical combination
1954 return;
1955 }
1956 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
1957 }
1958
1959 //--------------------------collect_nodes_in-----------------------------------
1960 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
1961 // The maximum depth is determined using a BFS that visits all primary (data
1962 // or control) inputs and increments the depth at each level.
1963 uint d_in = 0;
1964 GrowableArray<Node*> nodes(Compile::current()->unique());
1965 nodes.push(start);
1966 int nodes_at_current_level = 1;
1967 int n_idx = 0;
1968 while (nodes_at_current_level > 0) {
1969 // Add all primary inputs reachable from the current level to the list, and
1970 // increase the depth if there were any.
1971 int nodes_at_next_level = 0;
1972 bool nodes_added = false;
1973 while (nodes_at_current_level > 0) {
1974 nodes_at_current_level--;
1975 Node* current = nodes.at(n_idx++);
1976 for (uint i = 0; i < current->len(); i++) {
1977 Node* n = current->in(i);
1978 if (NotANode(n)) {
1979 continue;
1980 }
1981 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
1982 continue;
1983 }
1984 if (!nodes.contains(n)) {
1985 nodes.push(n);
1986 nodes_added = true;
1987 nodes_at_next_level++;
1988 }
1989 }
1990 }
1991 if (nodes_added) {
1992 d_in++;
1993 }
1994 nodes_at_current_level = nodes_at_next_level;
1995 }
1996 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
1997 if (collect_secondary) {
1998 // Now, iterate over the secondary nodes in ns and add the respective
1999 // boundary reachable from them.
2000 GrowableArray<Node*> sns(Compile::current()->unique());
2001 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2002 Node* n = *it;
2003 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2004 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2005 ns->append_if_missing(*d);
2006 }
2007 sns.clear();
2008 }
2009 }
2010 }
2011
2012 //---------------------collect_nodes_in_all_data-------------------------------
2013 // Collect the entire data input graph. Include the control boundary if
2014 // requested.
2015 // Arguments:
2016 // ns: collect the nodes into this data structure.
2017 // ctrl: if true, include the control boundary.
2018 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2019 collect_nodes_in((Node*) this, ns, true, ctrl);
2020 }
2021
2022 //--------------------------collect_nodes_in_all_ctrl--------------------------
2023 // Collect the entire control input graph. Include the data boundary if
2024 // requested.
2025 // ns: collect the nodes into this data structure.
2026 // data: if true, include the control boundary.
2027 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2028 collect_nodes_in((Node*) this, ns, false, data);
2029 }
2030
2031 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2032 // Collect the entire output graph until hitting control node boundaries, and
2033 // include those.
2034 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2035 // Perform a BFS and stop at control nodes.
2036 GrowableArray<Node*> nodes(Compile::current()->unique());
2037 nodes.push((Node*) this);
2038 while (nodes.length() > 0) {
2039 Node* current = nodes.pop();
2040 if (NotANode(current)) {
2041 continue;
2042 }
2043 ns->append_if_missing(current);
2044 if (!current->is_CFG()) {
2045 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2046 nodes.push(current->out(i));
2047 }
2048 }
2049 }
2050 ns->remove((Node*) this);
2051 }
2052
2053 // VERIFICATION CODE
2054 // For each input edge to a node (ie - for each Use-Def edge), verify that
2055 // there is a corresponding Def-Use edge.
2056 //------------------------------verify_edges-----------------------------------
2057 void Node::verify_edges(Unique_Node_List &visited) {
2058 uint i, j, idx;
2059 int cnt;
2060 Node *n;
2061
2062 // Recursive termination test
2063 if (visited.member(this)) return;
2064 visited.push(this);
2065
2066 // Walk over all input edges, checking for correspondence
2067 for( i = 0; i < len(); i++ ) {
2068 n = in(i);
2069 if (n != NULL && !n->is_top()) {
2070 // Count instances of (Node *)this
2071 cnt = 0;
2072 for (idx = 0; idx < n->_outcnt; idx++ ) {
2073 if (n->_out[idx] == (Node *)this) cnt++;
2074 }
2075 assert( cnt > 0,"Failed to find Def-Use edge." );
2076 // Check for duplicate edges
2077 // walk the input array downcounting the input edges to n
2078 for( j = 0; j < len(); j++ ) {
2079 if( in(j) == n ) cnt--;
2080 }
2081 assert( cnt == 0,"Mismatched edge count.");
2082 } else if (n == NULL) {
2083 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
2084 } else {
2085 assert(n->is_top(), "sanity");
2086 // Nothing to check.
2087 }
2088 }
2089 // Recursive walk over all input edges
2090 for( i = 0; i < len(); i++ ) {
2091 n = in(i);
2092 if( n != NULL )
2093 in(i)->verify_edges(visited);
2094 }
2095 }
2096
2097 //------------------------------verify_recur-----------------------------------
2098 static const Node *unique_top = NULL;
2099
2100 void Node::verify_recur(const Node *n, int verify_depth,
2101 VectorSet &old_space, VectorSet &new_space) {
2102 if ( verify_depth == 0 ) return;
2103 if (verify_depth > 0) --verify_depth;
2104
2105 Compile* C = Compile::current();
2106
2107 // Contained in new_space or old_space?
2108 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2109 // Check for visited in the proper space. Numberings are not unique
2110 // across spaces so we need a separate VectorSet for each space.
2111 if( v->test_set(n->_idx) ) return;
2112
2113 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2114 if (C->cached_top_node() == NULL)
2115 C->set_cached_top_node((Node*)n);
2116 assert(C->cached_top_node() == n, "TOP node must be unique");
2117 }
2118
2119 for( uint i = 0; i < n->len(); i++ ) {
2120 Node *x = n->in(i);
2121 if (!x || x->is_top()) continue;
2122
2123 // Verify my input has a def-use edge to me
2124 if (true /*VerifyDefUse*/) {
2125 // Count use-def edges from n to x
2126 int cnt = 0;
2127 for( uint j = 0; j < n->len(); j++ )
2128 if( n->in(j) == x )
2129 cnt++;
2130 // Count def-use edges from x to n
2131 uint max = x->_outcnt;
2132 for( uint k = 0; k < max; k++ )
2133 if (x->_out[k] == n)
2134 cnt--;
2135 assert( cnt == 0, "mismatched def-use edge counts" );
2136 }
2137
2138 verify_recur(x, verify_depth, old_space, new_space);
2139 }
2140
2141 }
2142
2143 //------------------------------verify-----------------------------------------
2144 // Check Def-Use info for my subgraph
2145 void Node::verify() const {
2146 Compile* C = Compile::current();
2147 Node* old_top = C->cached_top_node();
2148 ResourceMark rm;
2149 ResourceArea *area = Thread::current()->resource_area();
2150 VectorSet old_space(area), new_space(area);
2151 verify_recur(this, -1, old_space, new_space);
2152 C->set_cached_top_node(old_top);
2153 }
2154 #endif
2155
2156
2157 //------------------------------walk-------------------------------------------
2158 // Graph walk, with both pre-order and post-order functions
2159 void Node::walk(NFunc pre, NFunc post, void *env) {
2160 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2161 walk_(pre, post, env, visited);
2162 }
2163
2164 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2165 if( visited.test_set(_idx) ) return;
2166 pre(*this,env); // Call the pre-order walk function
2167 for( uint i=0; i<_max; i++ )
2168 if( in(i) ) // Input exists and is not walked?
2169 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2170 post(*this,env); // Call the post-order walk function
2171 }
2172
2173 void Node::nop(Node &, void*) {}
2174
2175 //------------------------------Registers--------------------------------------
2176 // Do we Match on this edge index or not? Generally false for Control
2177 // and true for everything else. Weird for calls & returns.
2178 uint Node::match_edge(uint idx) const {
2179 return idx; // True for other than index 0 (control)
2180 }
2181
2182 static RegMask _not_used_at_all;
2183 // Register classes are defined for specific machines
2184 const RegMask &Node::out_RegMask() const {
2185 ShouldNotCallThis();
2186 return _not_used_at_all;
2187 }
2188
2189 const RegMask &Node::in_RegMask(uint) const {
2190 ShouldNotCallThis();
2191 return _not_used_at_all;
2192 }
2193
2194 //=============================================================================
2195 //-----------------------------------------------------------------------------
2196 void Node_Array::reset( Arena *new_arena ) {
2197 _a->Afree(_nodes,_max*sizeof(Node*));
2198 _max = 0;
2199 _nodes = NULL;
2200 _a = new_arena;
2201 }
2202
2203 //------------------------------clear------------------------------------------
2204 // Clear all entries in _nodes to NULL but keep storage
2205 void Node_Array::clear() {
2206 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2207 }
2208
2209 //-----------------------------------------------------------------------------
2210 void Node_Array::grow( uint i ) {
2211 if( !_max ) {
2212 _max = 1;
2213 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2214 _nodes[0] = NULL;
2215 }
2216 uint old = _max;
2217 while( i >= _max ) _max <<= 1; // Double to fit
2218 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2219 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2220 }
2221
2222 //-----------------------------------------------------------------------------
2223 void Node_Array::insert( uint i, Node *n ) {
2224 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2225 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2226 _nodes[i] = n;
2227 }
2228
2229 //-----------------------------------------------------------------------------
2230 void Node_Array::remove( uint i ) {
2231 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2232 _nodes[_max-1] = NULL;
2233 }
2234
2235 //-----------------------------------------------------------------------------
2236 void Node_Array::sort( C_sort_func_t func) {
2237 qsort( _nodes, _max, sizeof( Node* ), func );
2238 }
2239
2240 //-----------------------------------------------------------------------------
2241 void Node_Array::dump() const {
2242 #ifndef PRODUCT
2243 for( uint i = 0; i < _max; i++ ) {
2244 Node *nn = _nodes[i];
2245 if( nn != NULL ) {
2246 tty->print("%5d--> ",i); nn->dump();
2247 }
2248 }
2249 #endif
2250 }
2251
2252 //--------------------------is_iteratively_computed------------------------------
2253 // Operation appears to be iteratively computed (such as an induction variable)
2254 // It is possible for this operation to return false for a loop-varying
2255 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2256 bool Node::is_iteratively_computed() {
2257 if (ideal_reg()) { // does operation have a result register?
2258 for (uint i = 1; i < req(); i++) {
2259 Node* n = in(i);
2260 if (n != NULL && n->is_Phi()) {
2261 for (uint j = 1; j < n->req(); j++) {
2262 if (n->in(j) == this) {
2263 return true;
2264 }
2265 }
2266 }
2267 }
2268 }
2269 return false;
2270 }
2271
2272 //--------------------------find_similar------------------------------
2273 // Return a node with opcode "opc" and same inputs as "this" if one can
2274 // be found; Otherwise return NULL;
2275 Node* Node::find_similar(int opc) {
2276 if (req() >= 2) {
2277 Node* def = in(1);
2278 if (def && def->outcnt() >= 2) {
2279 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2280 Node* use = def->fast_out(i);
2281 if (use != this &&
2282 use->Opcode() == opc &&
2283 use->req() == req()) {
2284 uint j;
2285 for (j = 0; j < use->req(); j++) {
2286 if (use->in(j) != in(j)) {
2287 break;
2288 }
2289 }
2290 if (j == use->req()) {
2291 return use;
2292 }
2293 }
2294 }
2295 }
2296 }
2297 return NULL;
2298 }
2299
2300
2301 //--------------------------unique_ctrl_out------------------------------
2302 // Return the unique control out if only one. Null if none or more than one.
2303 Node* Node::unique_ctrl_out() const {
2304 Node* found = NULL;
2305 for (uint i = 0; i < outcnt(); i++) {
2306 Node* use = raw_out(i);
2307 if (use->is_CFG() && use != this) {
2308 if (found != NULL) return NULL;
2309 found = use;
2310 }
2311 }
2312 return found;
2313 }
2314
2315 void Node::ensure_control_or_add_prec(Node* c) {
2316 if (in(0) == NULL) {
2317 set_req(0, c);
2318 } else if (in(0) != c) {
2319 add_prec(c);
2320 }
2321 }
2322
2323 //=============================================================================
2324 //------------------------------yank-------------------------------------------
2325 // Find and remove
2326 void Node_List::yank( Node *n ) {
2327 uint i;
2328 for( i = 0; i < _cnt; i++ )
2329 if( _nodes[i] == n )
2330 break;
2331
2332 if( i < _cnt )
2333 _nodes[i] = _nodes[--_cnt];
2334 }
2335
2336 //------------------------------dump-------------------------------------------
2337 void Node_List::dump() const {
2338 #ifndef PRODUCT
2339 for( uint i = 0; i < _cnt; i++ )
2340 if( _nodes[i] ) {
2341 tty->print("%5d--> ",i);
2342 _nodes[i]->dump();
2343 }
2344 #endif
2345 }
2346
2347 void Node_List::dump_simple() const {
2348 #ifndef PRODUCT
2349 for( uint i = 0; i < _cnt; i++ )
2350 if( _nodes[i] ) {
2351 tty->print(" %d", _nodes[i]->_idx);
2352 } else {
2353 tty->print(" NULL");
2354 }
2355 #endif
2356 }
2357
2358 //=============================================================================
2359 //------------------------------remove-----------------------------------------
2360 void Unique_Node_List::remove( Node *n ) {
2361 if( _in_worklist[n->_idx] ) {
2362 for( uint i = 0; i < size(); i++ )
2363 if( _nodes[i] == n ) {
2364 map(i,Node_List::pop());
2365 _in_worklist >>= n->_idx;
2366 return;
2367 }
2368 ShouldNotReachHere();
2369 }
2370 }
2371
2372 //-----------------------remove_useless_nodes----------------------------------
2373 // Remove useless nodes from worklist
2374 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2375
2376 for( uint i = 0; i < size(); ++i ) {
2377 Node *n = at(i);
2378 assert( n != NULL, "Did not expect null entries in worklist");
2379 if( ! useful.test(n->_idx) ) {
2380 _in_worklist >>= n->_idx;
2381 map(i,Node_List::pop());
2382 // Node *replacement = Node_List::pop();
2383 // if( i != size() ) { // Check if removing last entry
2384 // _nodes[i] = replacement;
2385 // }
2386 --i; // Visit popped node
2387 // If it was last entry, loop terminates since size() was also reduced
2388 }
2389 }
2390 }
2391
2392 //=============================================================================
2393 void Node_Stack::grow() {
2394 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2395 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2396 size_t max = old_max << 1; // max * 2
2397 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2398 _inode_max = _inodes + max;
2399 _inode_top = _inodes + old_top; // restore _top
2400 }
2401
2402 // Node_Stack is used to map nodes.
2403 Node* Node_Stack::find(uint idx) const {
2404 uint sz = size();
2405 for (uint i=0; i < sz; i++) {
2406 if (idx == index_at(i) )
2407 return node_at(i);
2408 }
2409 return NULL;
2410 }
2411
2412 //=============================================================================
2413 uint TypeNode::size_of() const { return sizeof(*this); }
2414 #ifndef PRODUCT
2415 void TypeNode::dump_spec(outputStream *st) const {
2416 if( !Verbose && !WizardMode ) {
2417 // standard dump does this in Verbose and WizardMode
2418 st->print(" #"); _type->dump_on(st);
2419 }
2420 }
2421
2422 void TypeNode::dump_compact_spec(outputStream *st) const {
2423 st->print("#");
2424 _type->dump_on(st);
2425 }
2426 #endif
2427 uint TypeNode::hash() const {
2428 return Node::hash() + _type->hash();
2429 }
2430 uint TypeNode::cmp( const Node &n ) const
2431 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2432 const Type *TypeNode::bottom_type() const { return _type; }
2433 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
2434
2435 //------------------------------ideal_reg--------------------------------------
2436 uint TypeNode::ideal_reg() const {
2437 return _type->ideal_reg();
2438 }