1 /*
2 * Copyright (c) 1997, 2015, 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 #ifdef __clang__
51 #pragma clang diagnostic push
52 #pragma GCC diagnostic ignored "-Wuninitialized"
53 #endif
54
55 #ifdef ASSERT
56
57 //-------------------------- construct_node------------------------------------
58 // Set a breakpoint here to identify where a particular node index is built.
59 void Node::verify_construction() {
60 _debug_orig = NULL;
61 int old_debug_idx = Compile::debug_idx();
62 int new_debug_idx = old_debug_idx+1;
63 if (new_debug_idx > 0) {
64 // Arrange that the lowest five decimal digits of _debug_idx
65 // will repeat those of _idx. In case this is somehow pathological,
66 // we continue to assign negative numbers (!) consecutively.
67 const int mod = 100000;
68 int bump = (int)(_idx - new_debug_idx) % mod;
69 if (bump < 0) bump += mod;
70 assert(bump >= 0 && bump < mod, "");
71 new_debug_idx += bump;
72 }
73 Compile::set_debug_idx(new_debug_idx);
74 set_debug_idx( new_debug_idx );
75 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
76 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
77 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
78 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
79 BREAKPOINT;
80 }
81 #if OPTO_DU_ITERATOR_ASSERT
82 _last_del = NULL;
83 _del_tick = 0;
84 #endif
85 _hash_lock = 0;
86 }
87
88
89 // #ifdef ASSERT ...
90
91 #if OPTO_DU_ITERATOR_ASSERT
92 void DUIterator_Common::sample(const Node* node) {
93 _vdui = VerifyDUIterators;
94 _node = node;
95 _outcnt = node->_outcnt;
96 _del_tick = node->_del_tick;
97 _last = NULL;
98 }
99
100 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
101 assert(_node == node, "consistent iterator source");
102 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
103 }
104
105 void DUIterator_Common::verify_resync() {
106 // Ensure that the loop body has just deleted the last guy produced.
107 const Node* node = _node;
108 // Ensure that at least one copy of the last-seen edge was deleted.
109 // Note: It is OK to delete multiple copies of the last-seen edge.
110 // Unfortunately, we have no way to verify that all the deletions delete
111 // that same edge. On this point we must use the Honor System.
112 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
113 assert(node->_last_del == _last, "must have deleted the edge just produced");
114 // We liked this deletion, so accept the resulting outcnt and tick.
115 _outcnt = node->_outcnt;
116 _del_tick = node->_del_tick;
117 }
118
119 void DUIterator_Common::reset(const DUIterator_Common& that) {
120 if (this == &that) return; // ignore assignment to self
121 if (!_vdui) {
122 // We need to initialize everything, overwriting garbage values.
123 _last = that._last;
124 _vdui = that._vdui;
125 }
126 // Note: It is legal (though odd) for an iterator over some node x
127 // to be reassigned to iterate over another node y. Some doubly-nested
128 // progress loops depend on being able to do this.
129 const Node* node = that._node;
130 // Re-initialize everything, except _last.
131 _node = node;
132 _outcnt = node->_outcnt;
133 _del_tick = node->_del_tick;
134 }
135
136 void DUIterator::sample(const Node* node) {
137 DUIterator_Common::sample(node); // Initialize the assertion data.
138 _refresh_tick = 0; // No refreshes have happened, as yet.
139 }
140
141 void DUIterator::verify(const Node* node, bool at_end_ok) {
142 DUIterator_Common::verify(node, at_end_ok);
143 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
144 }
145
146 void DUIterator::verify_increment() {
147 if (_refresh_tick & 1) {
148 // We have refreshed the index during this loop.
149 // Fix up _idx to meet asserts.
150 if (_idx > _outcnt) _idx = _outcnt;
151 }
152 verify(_node, true);
153 }
154
155 void DUIterator::verify_resync() {
156 // Note: We do not assert on _outcnt, because insertions are OK here.
157 DUIterator_Common::verify_resync();
158 // Make sure we are still in sync, possibly with no more out-edges:
159 verify(_node, true);
160 }
161
162 void DUIterator::reset(const DUIterator& that) {
163 if (this == &that) return; // self assignment is always a no-op
164 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
165 assert(that._idx == 0, "assign only the result of Node::outs()");
166 assert(_idx == that._idx, "already assigned _idx");
167 if (!_vdui) {
168 // We need to initialize everything, overwriting garbage values.
169 sample(that._node);
170 } else {
171 DUIterator_Common::reset(that);
172 if (_refresh_tick & 1) {
173 _refresh_tick++; // Clear the "was refreshed" flag.
174 }
175 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
176 }
177 }
178
179 void DUIterator::refresh() {
180 DUIterator_Common::sample(_node); // Re-fetch assertion data.
181 _refresh_tick |= 1; // Set the "was refreshed" flag.
182 }
183
184 void DUIterator::verify_finish() {
185 // If the loop has killed the node, do not require it to re-run.
186 if (_node->_outcnt == 0) _refresh_tick &= ~1;
187 // If this assert triggers, it means that a loop used refresh_out_pos
188 // to re-synch an iteration index, but the loop did not correctly
189 // re-run itself, using a "while (progress)" construct.
190 // This iterator enforces the rule that you must keep trying the loop
191 // until it "runs clean" without any need for refreshing.
192 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
193 }
194
195
196 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
197 DUIterator_Common::verify(node, at_end_ok);
198 Node** out = node->_out;
199 uint cnt = node->_outcnt;
200 assert(cnt == _outcnt, "no insertions allowed");
201 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
202 // This last check is carefully designed to work for NO_OUT_ARRAY.
203 }
204
205 void DUIterator_Fast::verify_limit() {
206 const Node* node = _node;
207 verify(node, true);
208 assert(_outp == node->_out + node->_outcnt, "limit still correct");
209 }
210
211 void DUIterator_Fast::verify_resync() {
212 const Node* node = _node;
213 if (_outp == node->_out + _outcnt) {
214 // Note that the limit imax, not the pointer i, gets updated with the
215 // exact count of deletions. (For the pointer it's always "--i".)
216 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
217 // This is a limit pointer, with a name like "imax".
218 // Fudge the _last field so that the common assert will be happy.
219 _last = (Node*) node->_last_del;
220 DUIterator_Common::verify_resync();
221 } else {
222 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
223 // A normal internal pointer.
224 DUIterator_Common::verify_resync();
225 // Make sure we are still in sync, possibly with no more out-edges:
226 verify(node, true);
227 }
228 }
229
230 void DUIterator_Fast::verify_relimit(uint n) {
231 const Node* node = _node;
232 assert((int)n > 0, "use imax -= n only with a positive count");
233 // This must be a limit pointer, with a name like "imax".
234 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
235 // The reported number of deletions must match what the node saw.
236 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
237 // Fudge the _last field so that the common assert will be happy.
238 _last = (Node*) node->_last_del;
239 DUIterator_Common::verify_resync();
240 }
241
242 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
243 assert(_outp == that._outp, "already assigned _outp");
244 DUIterator_Common::reset(that);
245 }
246
247 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
248 // at_end_ok means the _outp is allowed to underflow by 1
249 _outp += at_end_ok;
250 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
251 _outp -= at_end_ok;
252 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
253 }
254
255 void DUIterator_Last::verify_limit() {
256 // Do not require the limit address to be resynched.
257 //verify(node, true);
258 assert(_outp == _node->_out, "limit still correct");
259 }
260
261 void DUIterator_Last::verify_step(uint num_edges) {
262 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
263 _outcnt -= num_edges;
264 _del_tick += num_edges;
265 // Make sure we are still in sync, possibly with no more out-edges:
266 const Node* node = _node;
267 verify(node, true);
268 assert(node->_last_del == _last, "must have deleted the edge just produced");
269 }
270
271 #endif //OPTO_DU_ITERATOR_ASSERT
272
273
274 #endif //ASSERT
275
276
277 // This constant used to initialize _out may be any non-null value.
278 // The value NULL is reserved for the top node only.
279 #define NO_OUT_ARRAY ((Node**)-1)
280
281 // Out-of-line code from node constructors.
282 // Executed only when extra debug info. is being passed around.
283 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
284 C->set_node_notes_at(idx, nn);
285 }
286
287 // Shared initialization code.
288 inline int Node::Init(int req) {
289 Compile* C = Compile::current();
290 int idx = C->next_unique();
291
292 // Allocate memory for the necessary number of edges.
293 if (req > 0) {
294 // Allocate space for _in array to have double alignment.
295 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
296 #ifdef ASSERT
297 _in[req-1] = this; // magic cookie for assertion check
298 #endif
299 }
300 // If there are default notes floating around, capture them:
301 Node_Notes* nn = C->default_node_notes();
302 if (nn != NULL) init_node_notes(C, idx, nn);
303
304 // Note: At this point, C is dead,
305 // and we begin to initialize the new Node.
306
307 _cnt = _max = req;
308 _outcnt = _outmax = 0;
309 _class_id = Class_Node;
310 _flags = 0;
311 _out = NO_OUT_ARRAY;
312 return idx;
313 }
314
315 //------------------------------Node-------------------------------------------
316 // Create a Node, with a given number of required edges.
317 Node::Node(uint req)
318 : _idx(Init(req))
319 {
320 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
321 debug_only( verify_construction() );
322 NOT_PRODUCT(nodes_created++);
323 if (req == 0) {
324 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
325 _in = NULL;
326 } else {
327 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
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 {
339 debug_only( verify_construction() );
340 NOT_PRODUCT(nodes_created++);
341 // Assert we allocated space for input array already
342 assert( _in[0] == this, "Must pass arg count to 'new'" );
343 assert( is_not_dead(n0), "can not use dead node");
344 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
345 }
346
347 //------------------------------Node-------------------------------------------
348 Node::Node(Node *n0, Node *n1)
349 : _idx(Init(2))
350 {
351 debug_only( verify_construction() );
352 NOT_PRODUCT(nodes_created++);
353 // Assert we allocated space for input array already
354 assert( _in[1] == this, "Must pass arg count to 'new'" );
355 assert( is_not_dead(n0), "can not use dead node");
356 assert( is_not_dead(n1), "can not use dead node");
357 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
358 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
359 }
360
361 //------------------------------Node-------------------------------------------
362 Node::Node(Node *n0, Node *n1, Node *n2)
363 : _idx(Init(3))
364 {
365 debug_only( verify_construction() );
366 NOT_PRODUCT(nodes_created++);
367 // Assert we allocated space for input array already
368 assert( _in[2] == this, "Must pass arg count to 'new'" );
369 assert( is_not_dead(n0), "can not use dead node");
370 assert( is_not_dead(n1), "can not use dead node");
371 assert( is_not_dead(n2), "can not use dead node");
372 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
373 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
374 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
375 }
376
377 //------------------------------Node-------------------------------------------
378 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
379 : _idx(Init(4))
380 {
381 debug_only( verify_construction() );
382 NOT_PRODUCT(nodes_created++);
383 // Assert we allocated space for input array already
384 assert( _in[3] == this, "Must pass arg count to 'new'" );
385 assert( is_not_dead(n0), "can not use dead node");
386 assert( is_not_dead(n1), "can not use dead node");
387 assert( is_not_dead(n2), "can not use dead node");
388 assert( is_not_dead(n3), "can not use dead node");
389 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
390 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
391 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
392 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
393 }
394
395 //------------------------------Node-------------------------------------------
396 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
397 : _idx(Init(5))
398 {
399 debug_only( verify_construction() );
400 NOT_PRODUCT(nodes_created++);
401 // Assert we allocated space for input array already
402 assert( _in[4] == this, "Must pass arg count to 'new'" );
403 assert( is_not_dead(n0), "can not use dead node");
404 assert( is_not_dead(n1), "can not use dead node");
405 assert( is_not_dead(n2), "can not use dead node");
406 assert( is_not_dead(n3), "can not use dead node");
407 assert( is_not_dead(n4), "can not use dead node");
408 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
409 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
410 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
411 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
412 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
413 }
414
415 //------------------------------Node-------------------------------------------
416 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
417 Node *n4, Node *n5)
418 : _idx(Init(6))
419 {
420 debug_only( verify_construction() );
421 NOT_PRODUCT(nodes_created++);
422 // Assert we allocated space for input array already
423 assert( _in[5] == this, "Must pass arg count to 'new'" );
424 assert( is_not_dead(n0), "can not use dead node");
425 assert( is_not_dead(n1), "can not use dead node");
426 assert( is_not_dead(n2), "can not use dead node");
427 assert( is_not_dead(n3), "can not use dead node");
428 assert( is_not_dead(n4), "can not use dead node");
429 assert( is_not_dead(n5), "can not use dead node");
430 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
431 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
432 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
433 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
434 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
435 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
436 }
437
438 //------------------------------Node-------------------------------------------
439 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
440 Node *n4, Node *n5, Node *n6)
441 : _idx(Init(7))
442 {
443 debug_only( verify_construction() );
444 NOT_PRODUCT(nodes_created++);
445 // Assert we allocated space for input array already
446 assert( _in[6] == this, "Must pass arg count to 'new'" );
447 assert( is_not_dead(n0), "can not use dead node");
448 assert( is_not_dead(n1), "can not use dead node");
449 assert( is_not_dead(n2), "can not use dead node");
450 assert( is_not_dead(n3), "can not use dead node");
451 assert( is_not_dead(n4), "can not use dead node");
452 assert( is_not_dead(n5), "can not use dead node");
453 assert( is_not_dead(n6), "can not use dead node");
454 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
455 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
456 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
457 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
458 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
459 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
460 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
461 }
462
463 #ifdef __clang__
464 #pragma clang diagnostic pop
465 #endif
466
467
468 //------------------------------clone------------------------------------------
469 // Clone a Node.
470 Node *Node::clone() const {
471 Compile* C = Compile::current();
472 uint s = size_of(); // Size of inherited Node
473 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
474 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
475 // Set the new input pointer array
476 n->_in = (Node**)(((char*)n)+s);
477 // Cannot share the old output pointer array, so kill it
478 n->_out = NO_OUT_ARRAY;
479 // And reset the counters to 0
480 n->_outcnt = 0;
481 n->_outmax = 0;
482 // Unlock this guy, since he is not in any hash table.
483 debug_only(n->_hash_lock = 0);
484 // Walk the old node's input list to duplicate its edges
485 uint i;
486 for( i = 0; i < len(); i++ ) {
487 Node *x = in(i);
488 n->_in[i] = x;
489 if (x != NULL) x->add_out(n);
490 }
491 if (is_macro())
492 C->add_macro_node(n);
493 if (is_expensive())
494 C->add_expensive_node(n);
495
496 n->set_idx(C->next_unique()); // Get new unique index as well
497 debug_only( n->verify_construction() );
498 NOT_PRODUCT(nodes_created++);
499 // Do not patch over the debug_idx of a clone, because it makes it
500 // impossible to break on the clone's moment of creation.
501 //debug_only( n->set_debug_idx( debug_idx() ) );
502
503 C->copy_node_notes_to(n, (Node*) this);
504
505 // MachNode clone
506 uint nopnds;
507 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
508 MachNode *mach = n->as_Mach();
509 MachNode *mthis = this->as_Mach();
510 // Get address of _opnd_array.
511 // It should be the same offset since it is the clone of this node.
512 MachOper **from = mthis->_opnds;
513 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
514 pointer_delta((const void*)from,
515 (const void*)(&mthis->_opnds), 1));
516 mach->_opnds = to;
517 for ( uint i = 0; i < nopnds; ++i ) {
518 to[i] = from[i]->clone();
519 }
520 }
521 // cloning CallNode may need to clone JVMState
522 if (n->is_Call()) {
523 n->as_Call()->clone_jvms(C);
524 }
525 if (n->is_SafePoint()) {
526 n->as_SafePoint()->clone_replaced_nodes();
527 }
528 return n; // Return the clone
529 }
530
531 //---------------------------setup_is_top--------------------------------------
532 // Call this when changing the top node, to reassert the invariants
533 // required by Node::is_top. See Compile::set_cached_top_node.
534 void Node::setup_is_top() {
535 if (this == (Node*)Compile::current()->top()) {
536 // This node has just become top. Kill its out array.
537 _outcnt = _outmax = 0;
538 _out = NULL; // marker value for top
539 assert(is_top(), "must be top");
540 } else {
541 if (_out == NULL) _out = NO_OUT_ARRAY;
542 assert(!is_top(), "must not be top");
543 }
544 }
545
546
547 //------------------------------~Node------------------------------------------
548 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
549 extern int reclaim_idx ;
550 extern int reclaim_in ;
551 extern int reclaim_node;
552 void Node::destruct() {
553 // Eagerly reclaim unique Node numberings
554 Compile* compile = Compile::current();
555 if ((uint)_idx+1 == compile->unique()) {
556 compile->set_unique(compile->unique()-1);
557 #ifdef ASSERT
558 reclaim_idx++;
559 #endif
560 }
561 // Clear debug info:
562 Node_Notes* nn = compile->node_notes_at(_idx);
563 if (nn != NULL) nn->clear();
564 // Walk the input array, freeing the corresponding output edges
565 _cnt = _max; // forget req/prec distinction
566 uint i;
567 for( i = 0; i < _max; i++ ) {
568 set_req(i, NULL);
569 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
570 }
571 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
572 // See if the input array was allocated just prior to the object
573 int edge_size = _max*sizeof(void*);
574 int out_edge_size = _outmax*sizeof(void*);
575 char *edge_end = ((char*)_in) + edge_size;
576 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
577 char *out_edge_end = out_array + out_edge_size;
578 int node_size = size_of();
579
580 // Free the output edge array
581 if (out_edge_size > 0) {
582 #ifdef ASSERT
583 if( out_edge_end == compile->node_arena()->hwm() )
584 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
585 #endif
586 compile->node_arena()->Afree(out_array, out_edge_size);
587 }
588
589 // Free the input edge array and the node itself
590 if( edge_end == (char*)this ) {
591 #ifdef ASSERT
592 if( edge_end+node_size == compile->node_arena()->hwm() ) {
593 reclaim_in += edge_size;
594 reclaim_node+= node_size;
595 }
596 #else
597 // It was; free the input array and object all in one hit
598 compile->node_arena()->Afree(_in,edge_size+node_size);
599 #endif
600 } else {
601
602 // Free just the input array
603 #ifdef ASSERT
604 if( edge_end == compile->node_arena()->hwm() )
605 reclaim_in += edge_size;
606 #endif
607 compile->node_arena()->Afree(_in,edge_size);
608
609 // Free just the object
610 #ifdef ASSERT
611 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
612 reclaim_node+= node_size;
613 #else
614 compile->node_arena()->Afree(this,node_size);
615 #endif
616 }
617 if (is_macro()) {
618 compile->remove_macro_node(this);
619 }
620 if (is_expensive()) {
621 compile->remove_expensive_node(this);
622 }
623 if (is_SafePoint()) {
624 as_SafePoint()->delete_replaced_nodes();
625 }
626 #ifdef ASSERT
627 // We will not actually delete the storage, but we'll make the node unusable.
628 *(address*)this = badAddress; // smash the C++ vtbl, probably
629 _in = _out = (Node**) badAddress;
630 _max = _cnt = _outmax = _outcnt = 0;
631 compile->remove_modified_node(this);
632 #endif
633 }
634
635 //------------------------------grow-------------------------------------------
636 // Grow the input array, making space for more edges
637 void Node::grow( uint len ) {
638 Arena* arena = Compile::current()->node_arena();
639 uint new_max = _max;
640 if( new_max == 0 ) {
641 _max = 4;
642 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
643 Node** to = _in;
644 to[0] = NULL;
645 to[1] = NULL;
646 to[2] = NULL;
647 to[3] = NULL;
648 return;
649 }
650 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
651 // Trimming to limit allows a uint8 to handle up to 255 edges.
652 // Previously I was using only powers-of-2 which peaked at 128 edges.
653 //if( new_max >= limit ) new_max = limit-1;
654 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
655 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
656 _max = new_max; // Record new max length
657 // This assertion makes sure that Node::_max is wide enough to
658 // represent the numerical value of new_max.
659 assert(_max == new_max && _max > len, "int width of _max is too small");
660 }
661
662 //-----------------------------out_grow----------------------------------------
663 // Grow the input array, making space for more edges
664 void Node::out_grow( uint len ) {
665 assert(!is_top(), "cannot grow a top node's out array");
666 Arena* arena = Compile::current()->node_arena();
667 uint new_max = _outmax;
668 if( new_max == 0 ) {
669 _outmax = 4;
670 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
671 return;
672 }
673 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
674 // Trimming to limit allows a uint8 to handle up to 255 edges.
675 // Previously I was using only powers-of-2 which peaked at 128 edges.
676 //if( new_max >= limit ) new_max = limit-1;
677 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
678 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
679 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
680 _outmax = new_max; // Record new max length
681 // This assertion makes sure that Node::_max is wide enough to
682 // represent the numerical value of new_max.
683 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
684 }
685
686 #ifdef ASSERT
687 //------------------------------is_dead----------------------------------------
688 bool Node::is_dead() const {
689 // Mach and pinch point nodes may look like dead.
690 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
691 return false;
692 for( uint i = 0; i < _max; i++ )
693 if( _in[i] != NULL )
694 return false;
695 dump();
696 return true;
697 }
698 #endif
699
700
701 //------------------------------is_unreachable---------------------------------
702 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
703 assert(!is_Mach(), "doesn't work with MachNodes");
704 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
705 }
706
707 //------------------------------add_req----------------------------------------
708 // Add a new required input at the end
709 void Node::add_req( Node *n ) {
710 assert( is_not_dead(n), "can not use dead node");
711
712 // Look to see if I can move precedence down one without reallocating
713 if( (_cnt >= _max) || (in(_max-1) != NULL) )
714 grow( _max+1 );
715
716 // Find a precedence edge to move
717 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
718 uint i;
719 for( i=_cnt; i<_max; i++ )
720 if( in(i) == NULL ) // Find the NULL at end of prec edge list
721 break; // There must be one, since we grew the array
722 _in[i] = in(_cnt); // Move prec over, making space for req edge
723 }
724 _in[_cnt++] = n; // Stuff over old prec edge
725 if (n != NULL) n->add_out((Node *)this);
726 }
727
728 //---------------------------add_req_batch-------------------------------------
729 // Add a new required input at the end
730 void Node::add_req_batch( Node *n, uint m ) {
731 assert( is_not_dead(n), "can not use dead node");
732 // check various edge cases
733 if ((int)m <= 1) {
734 assert((int)m >= 0, "oob");
735 if (m != 0) add_req(n);
736 return;
737 }
738
739 // Look to see if I can move precedence down one without reallocating
740 if( (_cnt+m) > _max || _in[_max-m] )
741 grow( _max+m );
742
743 // Find a precedence edge to move
744 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
745 uint i;
746 for( i=_cnt; i<_max; i++ )
747 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
748 break; // There must be one, since we grew the array
749 // Slide all the precs over by m positions (assume #prec << m).
750 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
751 }
752
753 // Stuff over the old prec edges
754 for(uint i=0; i<m; i++ ) {
755 _in[_cnt++] = n;
756 }
757
758 // Insert multiple out edges on the node.
759 if (n != NULL && !n->is_top()) {
760 for(uint i=0; i<m; i++ ) {
761 n->add_out((Node *)this);
762 }
763 }
764 }
765
766 //------------------------------del_req----------------------------------------
767 // Delete the required edge and compact the edge array
768 void Node::del_req( uint idx ) {
769 assert( idx < _cnt, "oob");
770 assert( !VerifyHashTableKeys || _hash_lock == 0,
771 "remove node from hash table before modifying it");
772 // First remove corresponding def-use edge
773 Node *n = in(idx);
774 if (n != NULL) n->del_out((Node *)this);
775 _in[idx] = in(--_cnt); // Compact the array
776 _in[_cnt] = NULL; // NULL out emptied slot
777 Compile::current()->record_modified_node(this);
778 }
779
780 //------------------------------del_req_ordered--------------------------------
781 // Delete the required edge and compact the edge array with preserved order
782 void Node::del_req_ordered( uint idx ) {
783 assert( idx < _cnt, "oob");
784 assert( !VerifyHashTableKeys || _hash_lock == 0,
785 "remove node from hash table before modifying it");
786 // First remove corresponding def-use edge
787 Node *n = in(idx);
788 if (n != NULL) n->del_out((Node *)this);
789 if (idx < _cnt - 1) { // Not last edge ?
790 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
791 }
792 _in[--_cnt] = NULL; // NULL out emptied slot
793 Compile::current()->record_modified_node(this);
794 }
795
796 //------------------------------ins_req----------------------------------------
797 // Insert a new required input at the end
798 void Node::ins_req( uint idx, Node *n ) {
799 assert( is_not_dead(n), "can not use dead node");
800 add_req(NULL); // Make space
801 assert( idx < _max, "Must have allocated enough space");
802 // Slide over
803 if(_cnt-idx-1 > 0) {
804 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
805 }
806 _in[idx] = n; // Stuff over old required edge
807 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
808 }
809
810 //-----------------------------find_edge---------------------------------------
811 int Node::find_edge(Node* n) {
812 for (uint i = 0; i < len(); i++) {
813 if (_in[i] == n) return i;
814 }
815 return -1;
816 }
817
818 //----------------------------replace_edge-------------------------------------
819 int Node::replace_edge(Node* old, Node* neww) {
820 if (old == neww) return 0; // nothing to do
821 uint nrep = 0;
822 for (uint i = 0; i < len(); i++) {
823 if (in(i) == old) {
824 if (i < req())
825 set_req(i, neww);
826 else
827 set_prec(i, neww);
828 nrep++;
829 }
830 }
831 return nrep;
832 }
833
834 /**
835 * Replace input edges in the range pointing to 'old' node.
836 */
837 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
838 if (old == neww) return 0; // nothing to do
839 uint nrep = 0;
840 for (int i = start; i < end; i++) {
841 if (in(i) == old) {
842 set_req(i, neww);
843 nrep++;
844 }
845 }
846 return nrep;
847 }
848
849 //-------------------------disconnect_inputs-----------------------------------
850 // NULL out all inputs to eliminate incoming Def-Use edges.
851 // Return the number of edges between 'n' and 'this'
852 int Node::disconnect_inputs(Node *n, Compile* C) {
853 int edges_to_n = 0;
854
855 uint cnt = req();
856 for( uint i = 0; i < cnt; ++i ) {
857 if( in(i) == 0 ) continue;
858 if( in(i) == n ) ++edges_to_n;
859 set_req(i, NULL);
860 }
861 // Remove precedence edges if any exist
862 // Note: Safepoints may have precedence edges, even during parsing
863 if( (req() != len()) && (in(req()) != NULL) ) {
864 uint max = len();
865 for( uint i = 0; i < max; ++i ) {
866 if( in(i) == 0 ) continue;
867 if( in(i) == n ) ++edges_to_n;
868 set_prec(i, NULL);
869 }
870 }
871
872 // Node::destruct requires all out edges be deleted first
873 // debug_only(destruct();) // no reuse benefit expected
874 if (edges_to_n == 0) {
875 C->record_dead_node(_idx);
876 }
877 return edges_to_n;
878 }
879
880 //-----------------------------uncast---------------------------------------
881 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
882 // Strip away casting. (It is depth-limited.)
883 Node* Node::uncast() const {
884 // Should be inline:
885 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
886 if (is_ConstraintCast() || is_CheckCastPP())
887 return uncast_helper(this);
888 else
889 return (Node*) this;
890 }
891
892 // Find out of current node that matches opcode.
893 Node* Node::find_out_with(int opcode) {
894 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
895 Node* use = fast_out(i);
896 if (use->Opcode() == opcode) {
897 return use;
898 }
899 }
900 return NULL;
901 }
902
903 // Return true if the current node has an out that matches opcode.
904 bool Node::has_out_with(int opcode) {
905 return (find_out_with(opcode) != NULL);
906 }
907
908 // Return true if the current node has an out that matches any of the opcodes.
909 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
910 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
911 int opcode = fast_out(i)->Opcode();
912 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
913 return true;
914 }
915 }
916 return false;
917 }
918
919
920 //---------------------------uncast_helper-------------------------------------
921 Node* Node::uncast_helper(const Node* p) {
922 #ifdef ASSERT
923 uint depth_count = 0;
924 const Node* orig_p = p;
925 #endif
926
927 while (true) {
928 #ifdef ASSERT
929 if (depth_count >= K) {
930 orig_p->dump(4);
931 if (p != orig_p)
932 p->dump(1);
933 }
934 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
935 #endif
936 if (p == NULL || p->req() != 2) {
937 break;
938 } else if (p->is_ConstraintCast()) {
939 p = p->in(1);
940 } else if (p->is_CheckCastPP()) {
941 p = p->in(1);
942 } else {
943 break;
944 }
945 }
946 return (Node*) p;
947 }
948
949 //------------------------------add_prec---------------------------------------
950 // Add a new precedence input. Precedence inputs are unordered, with
951 // duplicates removed and NULLs packed down at the end.
952 void Node::add_prec( Node *n ) {
953 assert( is_not_dead(n), "can not use dead node");
954
955 // Check for NULL at end
956 if( _cnt >= _max || in(_max-1) )
957 grow( _max+1 );
958
959 // Find a precedence edge to move
960 uint i = _cnt;
961 while( in(i) != NULL ) i++;
962 _in[i] = n; // Stuff prec edge over NULL
963 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
964 }
965
966 //------------------------------rm_prec----------------------------------------
967 // Remove a precedence input. Precedence inputs are unordered, with
968 // duplicates removed and NULLs packed down at the end.
969 void Node::rm_prec( uint j ) {
970
971 // Find end of precedence list to pack NULLs
972 uint i;
973 for( i=j; i<_max; i++ )
974 if( !_in[i] ) // Find the NULL at end of prec edge list
975 break;
976 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
977 _in[j] = _in[--i]; // Move last element over removed guy
978 _in[i] = NULL; // NULL out last element
979 }
980
981 //------------------------------size_of----------------------------------------
982 uint Node::size_of() const { return sizeof(*this); }
983
984 //------------------------------ideal_reg--------------------------------------
985 uint Node::ideal_reg() const { return 0; }
986
987 //------------------------------jvms-------------------------------------------
988 JVMState* Node::jvms() const { return NULL; }
989
990 #ifdef ASSERT
991 //------------------------------jvms-------------------------------------------
992 bool Node::verify_jvms(const JVMState* using_jvms) const {
993 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
994 if (jvms == using_jvms) return true;
995 }
996 return false;
997 }
998
999 //------------------------------init_NodeProperty------------------------------
1000 void Node::init_NodeProperty() {
1001 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1002 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1003 }
1004 #endif
1005
1006 //------------------------------format-----------------------------------------
1007 // Print as assembly
1008 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1009 //------------------------------emit-------------------------------------------
1010 // Emit bytes starting at parameter 'ptr'.
1011 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1012 //------------------------------size-------------------------------------------
1013 // Size of instruction in bytes
1014 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1015
1016 //------------------------------CFG Construction-------------------------------
1017 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1018 // Goto and Return.
1019 const Node *Node::is_block_proj() const { return 0; }
1020
1021 // Minimum guaranteed type
1022 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1023
1024
1025 //------------------------------raise_bottom_type------------------------------
1026 // Get the worst-case Type output for this Node.
1027 void Node::raise_bottom_type(const Type* new_type) {
1028 if (is_Type()) {
1029 TypeNode *n = this->as_Type();
1030 if (VerifyAliases) {
1031 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1032 }
1033 n->set_type(new_type);
1034 } else if (is_Load()) {
1035 LoadNode *n = this->as_Load();
1036 if (VerifyAliases) {
1037 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1038 }
1039 n->set_type(new_type);
1040 }
1041 }
1042
1043 //------------------------------Identity---------------------------------------
1044 // Return a node that the given node is equivalent to.
1045 Node *Node::Identity( PhaseTransform * ) {
1046 return this; // Default to no identities
1047 }
1048
1049 //------------------------------Value------------------------------------------
1050 // Compute a new Type for a node using the Type of the inputs.
1051 const Type *Node::Value( PhaseTransform * ) const {
1052 return bottom_type(); // Default to worst-case Type
1053 }
1054
1055 //------------------------------Ideal------------------------------------------
1056 //
1057 // 'Idealize' the graph rooted at this Node.
1058 //
1059 // In order to be efficient and flexible there are some subtle invariants
1060 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1061 // these invariants, although its too slow to have on by default. If you are
1062 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1063 //
1064 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1065 // pointer. If ANY change is made, it must return the root of the reshaped
1066 // graph - even if the root is the same Node. Example: swapping the inputs
1067 // to an AddINode gives the same answer and same root, but you still have to
1068 // return the 'this' pointer instead of NULL.
1069 //
1070 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1071 // Identity call to return an old Node; basically if Identity can find
1072 // another Node have the Ideal call make no change and return NULL.
1073 // Example: AddINode::Ideal must check for add of zero; in this case it
1074 // returns NULL instead of doing any graph reshaping.
1075 //
1076 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1077 // sharing there may be other users of the old Nodes relying on their current
1078 // semantics. Modifying them will break the other users.
1079 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1080 // "X+3" unchanged in case it is shared.
1081 //
1082 // If you modify the 'this' pointer's inputs, you should use
1083 // 'set_req'. If you are making a new Node (either as the new root or
1084 // some new internal piece) you may use 'init_req' to set the initial
1085 // value. You can make a new Node with either 'new' or 'clone'. In
1086 // either case, def-use info is correctly maintained.
1087 //
1088 // Example: reshape "(X+3)+4" into "X+7":
1089 // set_req(1, in(1)->in(1));
1090 // set_req(2, phase->intcon(7));
1091 // return this;
1092 // Example: reshape "X*4" into "X<<2"
1093 // return new LShiftINode(in(1), phase->intcon(2));
1094 //
1095 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1096 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1097 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1098 // return new AddINode(shift, in(1));
1099 //
1100 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1101 // These forms are faster than 'phase->transform(new ConNode())' and Do
1102 // The Right Thing with def-use info.
1103 //
1104 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1105 // graph uses the 'this' Node it must be the root. If you want a Node with
1106 // the same Opcode as the 'this' pointer use 'clone'.
1107 //
1108 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1109 return NULL; // Default to being Ideal already
1110 }
1111
1112 // Some nodes have specific Ideal subgraph transformations only if they are
1113 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1114 // for the transformations to happen.
1115 bool Node::has_special_unique_user() const {
1116 assert(outcnt() == 1, "match only for unique out");
1117 Node* n = unique_out();
1118 int op = Opcode();
1119 if (this->is_Store()) {
1120 // Condition for back-to-back stores folding.
1121 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1122 } else if (this->is_Load()) {
1123 // Condition for removing an unused LoadNode from the MemBarAcquire precedence input
1124 return n->Opcode() == Op_MemBarAcquire;
1125 } else if (op == Op_AddL) {
1126 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1127 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1128 } else if (op == Op_SubI || op == Op_SubL) {
1129 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1130 return n->Opcode() == op && n->in(2) == this;
1131 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1132 // See IfProjNode::Identity()
1133 return true;
1134 }
1135 return false;
1136 };
1137
1138 //--------------------------find_exact_control---------------------------------
1139 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1140 Node* Node::find_exact_control(Node* ctrl) {
1141 if (ctrl == NULL && this->is_Region())
1142 ctrl = this->as_Region()->is_copy();
1143
1144 if (ctrl != NULL && ctrl->is_CatchProj()) {
1145 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1146 ctrl = ctrl->in(0);
1147 if (ctrl != NULL && !ctrl->is_top())
1148 ctrl = ctrl->in(0);
1149 }
1150
1151 if (ctrl != NULL && ctrl->is_Proj())
1152 ctrl = ctrl->in(0);
1153
1154 return ctrl;
1155 }
1156
1157 //--------------------------dominates------------------------------------------
1158 // Helper function for MemNode::all_controls_dominate().
1159 // Check if 'this' control node dominates or equal to 'sub' control node.
1160 // We already know that if any path back to Root or Start reaches 'this',
1161 // then all paths so, so this is a simple search for one example,
1162 // not an exhaustive search for a counterexample.
1163 bool Node::dominates(Node* sub, Node_List &nlist) {
1164 assert(this->is_CFG(), "expecting control");
1165 assert(sub != NULL && sub->is_CFG(), "expecting control");
1166
1167 // detect dead cycle without regions
1168 int iterations_without_region_limit = DominatorSearchLimit;
1169
1170 Node* orig_sub = sub;
1171 Node* dom = this;
1172 bool met_dom = false;
1173 nlist.clear();
1174
1175 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1176 // After seeing 'dom', continue up to Root or Start.
1177 // If we hit a region (backward split point), it may be a loop head.
1178 // Keep going through one of the region's inputs. If we reach the
1179 // same region again, go through a different input. Eventually we
1180 // will either exit through the loop head, or give up.
1181 // (If we get confused, break out and return a conservative 'false'.)
1182 while (sub != NULL) {
1183 if (sub->is_top()) break; // Conservative answer for dead code.
1184 if (sub == dom) {
1185 if (nlist.size() == 0) {
1186 // No Region nodes except loops were visited before and the EntryControl
1187 // path was taken for loops: it did not walk in a cycle.
1188 return true;
1189 } else if (met_dom) {
1190 break; // already met before: walk in a cycle
1191 } else {
1192 // Region nodes were visited. Continue walk up to Start or Root
1193 // to make sure that it did not walk in a cycle.
1194 met_dom = true; // first time meet
1195 iterations_without_region_limit = DominatorSearchLimit; // Reset
1196 }
1197 }
1198 if (sub->is_Start() || sub->is_Root()) {
1199 // Success if we met 'dom' along a path to Start or Root.
1200 // We assume there are no alternative paths that avoid 'dom'.
1201 // (This assumption is up to the caller to ensure!)
1202 return met_dom;
1203 }
1204 Node* up = sub->in(0);
1205 // Normalize simple pass-through regions and projections:
1206 up = sub->find_exact_control(up);
1207 // If sub == up, we found a self-loop. Try to push past it.
1208 if (sub == up && sub->is_Loop()) {
1209 // Take loop entry path on the way up to 'dom'.
1210 up = sub->in(1); // in(LoopNode::EntryControl);
1211 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1212 // Always take in(1) path on the way up to 'dom' for clone regions
1213 // (with only one input) or regions which merge > 2 paths
1214 // (usually used to merge fast/slow paths).
1215 up = sub->in(1);
1216 } else if (sub == up && sub->is_Region()) {
1217 // Try both paths for Regions with 2 input paths (it may be a loop head).
1218 // It could give conservative 'false' answer without information
1219 // which region's input is the entry path.
1220 iterations_without_region_limit = DominatorSearchLimit; // Reset
1221
1222 bool region_was_visited_before = false;
1223 // Was this Region node visited before?
1224 // If so, we have reached it because we accidentally took a
1225 // loop-back edge from 'sub' back into the body of the loop,
1226 // and worked our way up again to the loop header 'sub'.
1227 // So, take the first unexplored path on the way up to 'dom'.
1228 for (int j = nlist.size() - 1; j >= 0; j--) {
1229 intptr_t ni = (intptr_t)nlist.at(j);
1230 Node* visited = (Node*)(ni & ~1);
1231 bool visited_twice_already = ((ni & 1) != 0);
1232 if (visited == sub) {
1233 if (visited_twice_already) {
1234 // Visited 2 paths, but still stuck in loop body. Give up.
1235 return false;
1236 }
1237 // The Region node was visited before only once.
1238 // (We will repush with the low bit set, below.)
1239 nlist.remove(j);
1240 // We will find a new edge and re-insert.
1241 region_was_visited_before = true;
1242 break;
1243 }
1244 }
1245
1246 // Find an incoming edge which has not been seen yet; walk through it.
1247 assert(up == sub, "");
1248 uint skip = region_was_visited_before ? 1 : 0;
1249 for (uint i = 1; i < sub->req(); i++) {
1250 Node* in = sub->in(i);
1251 if (in != NULL && !in->is_top() && in != sub) {
1252 if (skip == 0) {
1253 up = in;
1254 break;
1255 }
1256 --skip; // skip this nontrivial input
1257 }
1258 }
1259
1260 // Set 0 bit to indicate that both paths were taken.
1261 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1262 }
1263
1264 if (up == sub) {
1265 break; // some kind of tight cycle
1266 }
1267 if (up == orig_sub && met_dom) {
1268 // returned back after visiting 'dom'
1269 break; // some kind of cycle
1270 }
1271 if (--iterations_without_region_limit < 0) {
1272 break; // dead cycle
1273 }
1274 sub = up;
1275 }
1276
1277 // Did not meet Root or Start node in pred. chain.
1278 // Conservative answer for dead code.
1279 return false;
1280 }
1281
1282 //------------------------------remove_dead_region-----------------------------
1283 // This control node is dead. Follow the subgraph below it making everything
1284 // using it dead as well. This will happen normally via the usual IterGVN
1285 // worklist but this call is more efficient. Do not update use-def info
1286 // inside the dead region, just at the borders.
1287 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1288 // Con's are a popular node to re-hit in the hash table again.
1289 if( dead->is_Con() ) return;
1290
1291 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1292 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1293 Node_List nstack(Thread::current()->resource_area());
1294
1295 Node *top = igvn->C->top();
1296 nstack.push(dead);
1297 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1298
1299 while (nstack.size() > 0) {
1300 dead = nstack.pop();
1301 if (dead->outcnt() > 0) {
1302 // Keep dead node on stack until all uses are processed.
1303 nstack.push(dead);
1304 // For all Users of the Dead... ;-)
1305 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1306 Node* use = dead->last_out(k);
1307 igvn->hash_delete(use); // Yank from hash table prior to mod
1308 if (use->in(0) == dead) { // Found another dead node
1309 assert (!use->is_Con(), "Control for Con node should be Root node.");
1310 use->set_req(0, top); // Cut dead edge to prevent processing
1311 nstack.push(use); // the dead node again.
1312 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1313 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1314 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1315 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1316 use->set_req(0, top); // Cut self edge
1317 nstack.push(use);
1318 } else { // Else found a not-dead user
1319 // Dead if all inputs are top or null
1320 bool dead_use = !use->is_Root(); // Keep empty graph alive
1321 for (uint j = 1; j < use->req(); j++) {
1322 Node* in = use->in(j);
1323 if (in == dead) { // Turn all dead inputs into TOP
1324 use->set_req(j, top);
1325 } else if (in != NULL && !in->is_top()) {
1326 dead_use = false;
1327 }
1328 }
1329 if (dead_use) {
1330 if (use->is_Region()) {
1331 use->set_req(0, top); // Cut self edge
1332 }
1333 nstack.push(use);
1334 } else {
1335 igvn->_worklist.push(use);
1336 }
1337 }
1338 // Refresh the iterator, since any number of kills might have happened.
1339 k = dead->last_outs(kmin);
1340 }
1341 } else { // (dead->outcnt() == 0)
1342 // Done with outputs.
1343 igvn->hash_delete(dead);
1344 igvn->_worklist.remove(dead);
1345 igvn->C->remove_modified_node(dead);
1346 igvn->set_type(dead, Type::TOP);
1347 if (dead->is_macro()) {
1348 igvn->C->remove_macro_node(dead);
1349 }
1350 if (dead->is_expensive()) {
1351 igvn->C->remove_expensive_node(dead);
1352 }
1353 igvn->C->record_dead_node(dead->_idx);
1354 // Kill all inputs to the dead guy
1355 for (uint i=0; i < dead->req(); i++) {
1356 Node *n = dead->in(i); // Get input to dead guy
1357 if (n != NULL && !n->is_top()) { // Input is valid?
1358 dead->set_req(i, top); // Smash input away
1359 if (n->outcnt() == 0) { // Input also goes dead?
1360 if (!n->is_Con())
1361 nstack.push(n); // Clear it out as well
1362 } else if (n->outcnt() == 1 &&
1363 n->has_special_unique_user()) {
1364 igvn->add_users_to_worklist( n );
1365 } else if (n->outcnt() <= 2 && n->is_Store()) {
1366 // Push store's uses on worklist to enable folding optimization for
1367 // store/store and store/load to the same address.
1368 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1369 // and remove_globally_dead_node().
1370 igvn->add_users_to_worklist( n );
1371 }
1372 }
1373 }
1374 } // (dead->outcnt() == 0)
1375 } // while (nstack.size() > 0) for outputs
1376 return;
1377 }
1378
1379 //------------------------------remove_dead_region-----------------------------
1380 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1381 Node *n = in(0);
1382 if( !n ) return false;
1383 // Lost control into this guy? I.e., it became unreachable?
1384 // Aggressively kill all unreachable code.
1385 if (can_reshape && n->is_top()) {
1386 kill_dead_code(this, phase->is_IterGVN());
1387 return false; // Node is dead.
1388 }
1389
1390 if( n->is_Region() && n->as_Region()->is_copy() ) {
1391 Node *m = n->nonnull_req();
1392 set_req(0, m);
1393 return true;
1394 }
1395 return false;
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 //------------------------------find------------------------------------------
1501 // Find a neighbor of this Node with the given _idx
1502 // If idx is negative, find its absolute value, following both _in and _out.
1503 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1504 VectorSet* old_space, VectorSet* new_space ) {
1505 int node_idx = (idx >= 0) ? idx : -idx;
1506 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1507 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1508 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1509 if( v->test(n->_idx) ) return;
1510 if( (int)n->_idx == node_idx
1511 debug_only(|| n->debug_idx() == node_idx) ) {
1512 if (result != NULL)
1513 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1514 (uintptr_t)result, (uintptr_t)n, node_idx);
1515 result = n;
1516 }
1517 v->set(n->_idx);
1518 for( uint i=0; i<n->len(); i++ ) {
1519 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1520 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1521 }
1522 // Search along forward edges also:
1523 if (idx < 0 && !only_ctrl) {
1524 for( uint j=0; j<n->outcnt(); j++ ) {
1525 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1526 }
1527 }
1528 #ifdef ASSERT
1529 // Search along debug_orig edges last, checking for cycles
1530 Node* orig = n->debug_orig();
1531 if (orig != NULL) {
1532 do {
1533 if (NotANode(orig)) break;
1534 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1535 orig = orig->debug_orig();
1536 } while (orig != NULL && orig != n->debug_orig());
1537 }
1538 #endif //ASSERT
1539 }
1540
1541 // call this from debugger:
1542 Node* find_node(Node* n, int idx) {
1543 return n->find(idx);
1544 }
1545
1546 //------------------------------find-------------------------------------------
1547 Node* Node::find(int idx) const {
1548 ResourceArea *area = Thread::current()->resource_area();
1549 VectorSet old_space(area), new_space(area);
1550 Node* result = NULL;
1551 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1552 return result;
1553 }
1554
1555 //------------------------------find_ctrl--------------------------------------
1556 // Find an ancestor to this node in the control history with given _idx
1557 Node* Node::find_ctrl(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, true, &old_space, &new_space );
1562 return result;
1563 }
1564 #endif
1565
1566
1567
1568 #ifndef PRODUCT
1569
1570 // -----------------------------Name-------------------------------------------
1571 extern const char *NodeClassNames[];
1572 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1573
1574 static bool is_disconnected(const Node* n) {
1575 for (uint i = 0; i < n->req(); i++) {
1576 if (n->in(i) != NULL) return false;
1577 }
1578 return true;
1579 }
1580
1581 #ifdef ASSERT
1582 static void dump_orig(Node* orig, outputStream *st) {
1583 Compile* C = Compile::current();
1584 if (NotANode(orig)) orig = NULL;
1585 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1586 if (orig == NULL) return;
1587 st->print(" !orig=");
1588 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1589 if (NotANode(fast)) fast = NULL;
1590 while (orig != NULL) {
1591 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1592 if (discon) st->print("[");
1593 if (!Compile::current()->node_arena()->contains(orig))
1594 st->print("o");
1595 st->print("%d", orig->_idx);
1596 if (discon) st->print("]");
1597 orig = orig->debug_orig();
1598 if (NotANode(orig)) orig = NULL;
1599 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1600 if (orig != NULL) st->print(",");
1601 if (fast != NULL) {
1602 // Step fast twice for each single step of orig:
1603 fast = fast->debug_orig();
1604 if (NotANode(fast)) fast = NULL;
1605 if (fast != NULL && fast != orig) {
1606 fast = fast->debug_orig();
1607 if (NotANode(fast)) fast = NULL;
1608 }
1609 if (fast == orig) {
1610 st->print("...");
1611 break;
1612 }
1613 }
1614 }
1615 }
1616
1617 void Node::set_debug_orig(Node* orig) {
1618 _debug_orig = orig;
1619 if (BreakAtNode == 0) return;
1620 if (NotANode(orig)) orig = NULL;
1621 int trip = 10;
1622 while (orig != NULL) {
1623 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1624 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1625 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1626 BREAKPOINT;
1627 }
1628 orig = orig->debug_orig();
1629 if (NotANode(orig)) orig = NULL;
1630 if (trip-- <= 0) break;
1631 }
1632 }
1633 #endif //ASSERT
1634
1635 //------------------------------dump------------------------------------------
1636 // Dump a Node
1637 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1638 Compile* C = Compile::current();
1639 bool is_new = C->node_arena()->contains(this);
1640 C->_in_dump_cnt++;
1641 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1642
1643 // Dump the required and precedence inputs
1644 dump_req(st);
1645 dump_prec(st);
1646 // Dump the outputs
1647 dump_out(st);
1648
1649 if (is_disconnected(this)) {
1650 #ifdef ASSERT
1651 st->print(" [%d]",debug_idx());
1652 dump_orig(debug_orig(), st);
1653 #endif
1654 st->cr();
1655 C->_in_dump_cnt--;
1656 return; // don't process dead nodes
1657 }
1658
1659 if (C->clone_map().value(_idx) != 0) {
1660 C->clone_map().dump(_idx);
1661 }
1662 // Dump node-specific info
1663 dump_spec(st);
1664 #ifdef ASSERT
1665 // Dump the non-reset _debug_idx
1666 if (Verbose && WizardMode) {
1667 st->print(" [%d]",debug_idx());
1668 }
1669 #endif
1670
1671 const Type *t = bottom_type();
1672
1673 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1674 const TypeInstPtr *toop = t->isa_instptr();
1675 const TypeKlassPtr *tkls = t->isa_klassptr();
1676 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1677 if (klass && klass->is_loaded() && klass->is_interface()) {
1678 st->print(" Interface:");
1679 } else if (toop) {
1680 st->print(" Oop:");
1681 } else if (tkls) {
1682 st->print(" Klass:");
1683 }
1684 t->dump_on(st);
1685 } else if (t == Type::MEMORY) {
1686 st->print(" Memory:");
1687 MemNode::dump_adr_type(this, adr_type(), st);
1688 } else if (Verbose || WizardMode) {
1689 st->print(" Type:");
1690 if (t) {
1691 t->dump_on(st);
1692 } else {
1693 st->print("no type");
1694 }
1695 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1696 // Dump MachSpillcopy vector type.
1697 t->dump_on(st);
1698 }
1699 if (is_new) {
1700 debug_only(dump_orig(debug_orig(), st));
1701 Node_Notes* nn = C->node_notes_at(_idx);
1702 if (nn != NULL && !nn->is_clear()) {
1703 if (nn->jvms() != NULL) {
1704 st->print(" !jvms:");
1705 nn->jvms()->dump_spec(st);
1706 }
1707 }
1708 }
1709 if (suffix) st->print("%s", suffix);
1710 C->_in_dump_cnt--;
1711 }
1712
1713 //------------------------------dump_req--------------------------------------
1714 void Node::dump_req(outputStream *st) const {
1715 // Dump the required input edges
1716 for (uint i = 0; i < req(); i++) { // For all required inputs
1717 Node* d = in(i);
1718 if (d == NULL) {
1719 st->print("_ ");
1720 } else if (NotANode(d)) {
1721 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1722 } else {
1723 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1724 }
1725 }
1726 }
1727
1728
1729 //------------------------------dump_prec-------------------------------------
1730 void Node::dump_prec(outputStream *st) const {
1731 // Dump the precedence edges
1732 int any_prec = 0;
1733 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1734 Node* p = in(i);
1735 if (p != NULL) {
1736 if (!any_prec++) st->print(" |");
1737 if (NotANode(p)) { st->print("NotANode "); continue; }
1738 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1739 }
1740 }
1741 }
1742
1743 //------------------------------dump_out--------------------------------------
1744 void Node::dump_out(outputStream *st) const {
1745 // Delimit the output edges
1746 st->print(" [[");
1747 // Dump the output edges
1748 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1749 Node* u = _out[i];
1750 if (u == NULL) {
1751 st->print("_ ");
1752 } else if (NotANode(u)) {
1753 st->print("NotANode ");
1754 } else {
1755 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1756 }
1757 }
1758 st->print("]] ");
1759 }
1760
1761 //----------------------------collect_nodes_i----------------------------------
1762 // Collects nodes from an Ideal graph, starting from a given start node and
1763 // moving in a given direction until a certain depth (distance from the start
1764 // node) is reached. Duplicates are ignored.
1765 // Arguments:
1766 // nstack: the nodes are collected into this array.
1767 // start: the node at which to start collecting.
1768 // direction: if this is a positive number, collect input nodes; if it is
1769 // a negative number, collect output nodes.
1770 // depth: collect nodes up to this distance from the start node.
1771 // include_start: whether to include the start node in the result collection.
1772 // only_ctrl: whether to regard control edges only during traversal.
1773 // only_data: whether to regard data edges only during traversal.
1774 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1775 Node* s = (Node*) start; // remove const
1776 nstack->append(s);
1777 int begin = 0;
1778 int end = 0;
1779 for(uint i = 0; i < depth; i++) {
1780 end = nstack->length();
1781 for(int j = begin; j < end; j++) {
1782 Node* tp = nstack->at(j);
1783 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1784 for(uint k = 0; k < limit; k++) {
1785 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1786
1787 if (NotANode(n)) continue;
1788 // do not recurse through top or the root (would reach unrelated stuff)
1789 if (n->is_Root() || n->is_top()) continue;
1790 if (only_ctrl && !n->is_CFG()) continue;
1791 if (only_data && n->is_CFG()) continue;
1792
1793 bool on_stack = nstack->contains(n);
1794 if (!on_stack) {
1795 nstack->append(n);
1796 }
1797 }
1798 }
1799 begin = end;
1800 }
1801 if (!include_start) {
1802 nstack->remove(s);
1803 }
1804 }
1805
1806 //------------------------------dump_nodes-------------------------------------
1807 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1808 if (NotANode(start)) return;
1809
1810 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1811 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1812
1813 int end = nstack.length();
1814 if (d > 0) {
1815 for(int j = end-1; j >= 0; j--) {
1816 nstack.at(j)->dump();
1817 }
1818 } else {
1819 for(int j = 0; j < end; j++) {
1820 nstack.at(j)->dump();
1821 }
1822 }
1823 }
1824
1825 //------------------------------dump-------------------------------------------
1826 void Node::dump(int d) const {
1827 dump_nodes(this, d, false);
1828 }
1829
1830 //------------------------------dump_ctrl--------------------------------------
1831 // Dump a Node's control history to depth
1832 void Node::dump_ctrl(int d) const {
1833 dump_nodes(this, d, true);
1834 }
1835
1836 //-----------------------------dump_compact------------------------------------
1837 void Node::dump_comp() const {
1838 this->dump_comp("\n");
1839 }
1840
1841 //-----------------------------dump_compact------------------------------------
1842 // Dump a Node in compact representation, i.e., just print its name and index.
1843 // Nodes can specify additional specifics to print in compact representation by
1844 // implementing dump_compact_spec.
1845 void Node::dump_comp(const char* suffix, outputStream *st) const {
1846 Compile* C = Compile::current();
1847 C->_in_dump_cnt++;
1848 st->print("%s(%d)", Name(), _idx);
1849 this->dump_compact_spec(st);
1850 if (suffix) {
1851 st->print("%s", suffix);
1852 }
1853 C->_in_dump_cnt--;
1854 }
1855
1856 //----------------------------dump_related-------------------------------------
1857 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1858 // hand and is determined by the implementation of the virtual method rel.
1859 void Node::dump_related() const {
1860 Compile* C = Compile::current();
1861 GrowableArray <Node *> in_rel(C->unique());
1862 GrowableArray <Node *> out_rel(C->unique());
1863 this->related(&in_rel, &out_rel, false);
1864 for (int i = in_rel.length() - 1; i >= 0; i--) {
1865 in_rel.at(i)->dump();
1866 }
1867 this->dump("\n", true);
1868 for (int i = 0; i < out_rel.length(); i++) {
1869 out_rel.at(i)->dump();
1870 }
1871 }
1872
1873 //----------------------------dump_related-------------------------------------
1874 // Dump a Node's related nodes up to a given depth (distance from the start
1875 // node).
1876 // Arguments:
1877 // d_in: depth for input nodes.
1878 // d_out: depth for output nodes (note: this also is a positive number).
1879 void Node::dump_related(uint d_in, uint d_out) const {
1880 Compile* C = Compile::current();
1881 GrowableArray <Node *> in_rel(C->unique());
1882 GrowableArray <Node *> out_rel(C->unique());
1883
1884 // call collect_nodes_i directly
1885 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1886 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1887
1888 for (int i = in_rel.length() - 1; i >= 0; i--) {
1889 in_rel.at(i)->dump();
1890 }
1891 this->dump("\n", true);
1892 for (int i = 0; i < out_rel.length(); i++) {
1893 out_rel.at(i)->dump();
1894 }
1895 }
1896
1897 //------------------------dump_related_compact---------------------------------
1898 // Dump a Node's related nodes in compact representation. The notion of
1899 // "related" depends on the Node at hand and is determined by the implementation
1900 // of the virtual method rel.
1901 void Node::dump_related_compact() const {
1902 Compile* C = Compile::current();
1903 GrowableArray <Node *> in_rel(C->unique());
1904 GrowableArray <Node *> out_rel(C->unique());
1905 this->related(&in_rel, &out_rel, true);
1906 int n_in = in_rel.length();
1907 int n_out = out_rel.length();
1908
1909 this->dump_comp(n_in == 0 ? "\n" : " ");
1910 for (int i = 0; i < n_in; i++) {
1911 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1912 }
1913 for (int i = 0; i < n_out; i++) {
1914 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1915 }
1916 }
1917
1918 //------------------------------related----------------------------------------
1919 // Collect a Node's related nodes. The default behaviour just collects the
1920 // inputs and outputs at depth 1, including both control and data flow edges,
1921 // regardless of whether the presentation is compact or not. For data nodes,
1922 // the default is to collect all data inputs (till level 1 if compact), and
1923 // outputs till level 1.
1924 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1925 if (this->is_CFG()) {
1926 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1927 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1928 } else {
1929 if (compact) {
1930 this->collect_nodes(in_rel, 1, false, true);
1931 } else {
1932 this->collect_nodes_in_all_data(in_rel, false);
1933 }
1934 this->collect_nodes(out_rel, -1, false, false);
1935 }
1936 }
1937
1938 //---------------------------collect_nodes-------------------------------------
1939 // An entry point to the low-level node collection facility, to start from a
1940 // given node in the graph. The start node is by default not included in the
1941 // result.
1942 // Arguments:
1943 // ns: collect the nodes into this data structure.
1944 // d: the depth (distance from start node) to which nodes should be
1945 // collected. A value >0 indicates input nodes, a value <0, output
1946 // nodes.
1947 // ctrl: include only control nodes.
1948 // data: include only data nodes.
1949 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
1950 if (ctrl && data) {
1951 // ignore nonsensical combination
1952 return;
1953 }
1954 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
1955 }
1956
1957 //--------------------------collect_nodes_in-----------------------------------
1958 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
1959 // The maximum depth is determined using a BFS that visits all primary (data
1960 // or control) inputs and increments the depth at each level.
1961 uint d_in = 0;
1962 GrowableArray<Node*> nodes(Compile::current()->unique());
1963 nodes.push(start);
1964 int nodes_at_current_level = 1;
1965 int n_idx = 0;
1966 while (nodes_at_current_level > 0) {
1967 // Add all primary inputs reachable from the current level to the list, and
1968 // increase the depth if there were any.
1969 int nodes_at_next_level = 0;
1970 bool nodes_added = false;
1971 while (nodes_at_current_level > 0) {
1972 nodes_at_current_level--;
1973 Node* current = nodes.at(n_idx++);
1974 for (uint i = 0; i < current->len(); i++) {
1975 Node* n = current->in(i);
1976 if (NotANode(n)) {
1977 continue;
1978 }
1979 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
1980 continue;
1981 }
1982 if (!nodes.contains(n)) {
1983 nodes.push(n);
1984 nodes_added = true;
1985 nodes_at_next_level++;
1986 }
1987 }
1988 }
1989 if (nodes_added) {
1990 d_in++;
1991 }
1992 nodes_at_current_level = nodes_at_next_level;
1993 }
1994 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
1995 if (collect_secondary) {
1996 // Now, iterate over the secondary nodes in ns and add the respective
1997 // boundary reachable from them.
1998 GrowableArray<Node*> sns(Compile::current()->unique());
1999 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2000 Node* n = *it;
2001 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2002 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2003 ns->append_if_missing(*d);
2004 }
2005 sns.clear();
2006 }
2007 }
2008 }
2009
2010 //---------------------collect_nodes_in_all_data-------------------------------
2011 // Collect the entire data input graph. Include the control boundary if
2012 // requested.
2013 // Arguments:
2014 // ns: collect the nodes into this data structure.
2015 // ctrl: if true, include the control boundary.
2016 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2017 collect_nodes_in((Node*) this, ns, true, ctrl);
2018 }
2019
2020 //--------------------------collect_nodes_in_all_ctrl--------------------------
2021 // Collect the entire control input graph. Include the data boundary if
2022 // requested.
2023 // ns: collect the nodes into this data structure.
2024 // data: if true, include the control boundary.
2025 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2026 collect_nodes_in((Node*) this, ns, false, data);
2027 }
2028
2029 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2030 // Collect the entire output graph until hitting control node boundaries, and
2031 // include those.
2032 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2033 // Perform a BFS and stop at control nodes.
2034 GrowableArray<Node*> nodes(Compile::current()->unique());
2035 nodes.push((Node*) this);
2036 while (nodes.length() > 0) {
2037 Node* current = nodes.pop();
2038 if (NotANode(current)) {
2039 continue;
2040 }
2041 ns->append_if_missing(current);
2042 if (!current->is_CFG()) {
2043 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2044 nodes.push(current->out(i));
2045 }
2046 }
2047 }
2048 ns->remove((Node*) this);
2049 }
2050
2051 // VERIFICATION CODE
2052 // For each input edge to a node (ie - for each Use-Def edge), verify that
2053 // there is a corresponding Def-Use edge.
2054 //------------------------------verify_edges-----------------------------------
2055 void Node::verify_edges(Unique_Node_List &visited) {
2056 uint i, j, idx;
2057 int cnt;
2058 Node *n;
2059
2060 // Recursive termination test
2061 if (visited.member(this)) return;
2062 visited.push(this);
2063
2064 // Walk over all input edges, checking for correspondence
2065 for( i = 0; i < len(); i++ ) {
2066 n = in(i);
2067 if (n != NULL && !n->is_top()) {
2068 // Count instances of (Node *)this
2069 cnt = 0;
2070 for (idx = 0; idx < n->_outcnt; idx++ ) {
2071 if (n->_out[idx] == (Node *)this) cnt++;
2072 }
2073 assert( cnt > 0,"Failed to find Def-Use edge." );
2074 // Check for duplicate edges
2075 // walk the input array downcounting the input edges to n
2076 for( j = 0; j < len(); j++ ) {
2077 if( in(j) == n ) cnt--;
2078 }
2079 assert( cnt == 0,"Mismatched edge count.");
2080 } else if (n == NULL) {
2081 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
2082 } else {
2083 assert(n->is_top(), "sanity");
2084 // Nothing to check.
2085 }
2086 }
2087 // Recursive walk over all input edges
2088 for( i = 0; i < len(); i++ ) {
2089 n = in(i);
2090 if( n != NULL )
2091 in(i)->verify_edges(visited);
2092 }
2093 }
2094
2095 //------------------------------verify_recur-----------------------------------
2096 static const Node *unique_top = NULL;
2097
2098 void Node::verify_recur(const Node *n, int verify_depth,
2099 VectorSet &old_space, VectorSet &new_space) {
2100 if ( verify_depth == 0 ) return;
2101 if (verify_depth > 0) --verify_depth;
2102
2103 Compile* C = Compile::current();
2104
2105 // Contained in new_space or old_space?
2106 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2107 // Check for visited in the proper space. Numberings are not unique
2108 // across spaces so we need a separate VectorSet for each space.
2109 if( v->test_set(n->_idx) ) return;
2110
2111 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2112 if (C->cached_top_node() == NULL)
2113 C->set_cached_top_node((Node*)n);
2114 assert(C->cached_top_node() == n, "TOP node must be unique");
2115 }
2116
2117 for( uint i = 0; i < n->len(); i++ ) {
2118 Node *x = n->in(i);
2119 if (!x || x->is_top()) continue;
2120
2121 // Verify my input has a def-use edge to me
2122 if (true /*VerifyDefUse*/) {
2123 // Count use-def edges from n to x
2124 int cnt = 0;
2125 for( uint j = 0; j < n->len(); j++ )
2126 if( n->in(j) == x )
2127 cnt++;
2128 // Count def-use edges from x to n
2129 uint max = x->_outcnt;
2130 for( uint k = 0; k < max; k++ )
2131 if (x->_out[k] == n)
2132 cnt--;
2133 assert( cnt == 0, "mismatched def-use edge counts" );
2134 }
2135
2136 verify_recur(x, verify_depth, old_space, new_space);
2137 }
2138
2139 }
2140
2141 //------------------------------verify-----------------------------------------
2142 // Check Def-Use info for my subgraph
2143 void Node::verify() const {
2144 Compile* C = Compile::current();
2145 Node* old_top = C->cached_top_node();
2146 ResourceMark rm;
2147 ResourceArea *area = Thread::current()->resource_area();
2148 VectorSet old_space(area), new_space(area);
2149 verify_recur(this, -1, old_space, new_space);
2150 C->set_cached_top_node(old_top);
2151 }
2152 #endif
2153
2154
2155 //------------------------------walk-------------------------------------------
2156 // Graph walk, with both pre-order and post-order functions
2157 void Node::walk(NFunc pre, NFunc post, void *env) {
2158 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2159 walk_(pre, post, env, visited);
2160 }
2161
2162 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2163 if( visited.test_set(_idx) ) return;
2164 pre(*this,env); // Call the pre-order walk function
2165 for( uint i=0; i<_max; i++ )
2166 if( in(i) ) // Input exists and is not walked?
2167 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2168 post(*this,env); // Call the post-order walk function
2169 }
2170
2171 void Node::nop(Node &, void*) {}
2172
2173 //------------------------------Registers--------------------------------------
2174 // Do we Match on this edge index or not? Generally false for Control
2175 // and true for everything else. Weird for calls & returns.
2176 uint Node::match_edge(uint idx) const {
2177 return idx; // True for other than index 0 (control)
2178 }
2179
2180 static RegMask _not_used_at_all;
2181 // Register classes are defined for specific machines
2182 const RegMask &Node::out_RegMask() const {
2183 ShouldNotCallThis();
2184 return _not_used_at_all;
2185 }
2186
2187 const RegMask &Node::in_RegMask(uint) const {
2188 ShouldNotCallThis();
2189 return _not_used_at_all;
2190 }
2191
2192 //=============================================================================
2193 //-----------------------------------------------------------------------------
2194 void Node_Array::reset( Arena *new_arena ) {
2195 _a->Afree(_nodes,_max*sizeof(Node*));
2196 _max = 0;
2197 _nodes = NULL;
2198 _a = new_arena;
2199 }
2200
2201 //------------------------------clear------------------------------------------
2202 // Clear all entries in _nodes to NULL but keep storage
2203 void Node_Array::clear() {
2204 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2205 }
2206
2207 //-----------------------------------------------------------------------------
2208 void Node_Array::grow( uint i ) {
2209 if( !_max ) {
2210 _max = 1;
2211 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2212 _nodes[0] = NULL;
2213 }
2214 uint old = _max;
2215 while( i >= _max ) _max <<= 1; // Double to fit
2216 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2217 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2218 }
2219
2220 //-----------------------------------------------------------------------------
2221 void Node_Array::insert( uint i, Node *n ) {
2222 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2223 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2224 _nodes[i] = n;
2225 }
2226
2227 //-----------------------------------------------------------------------------
2228 void Node_Array::remove( uint i ) {
2229 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2230 _nodes[_max-1] = NULL;
2231 }
2232
2233 //-----------------------------------------------------------------------------
2234 void Node_Array::sort( C_sort_func_t func) {
2235 qsort( _nodes, _max, sizeof( Node* ), func );
2236 }
2237
2238 //-----------------------------------------------------------------------------
2239 void Node_Array::dump() const {
2240 #ifndef PRODUCT
2241 for( uint i = 0; i < _max; i++ ) {
2242 Node *nn = _nodes[i];
2243 if( nn != NULL ) {
2244 tty->print("%5d--> ",i); nn->dump();
2245 }
2246 }
2247 #endif
2248 }
2249
2250 //--------------------------is_iteratively_computed------------------------------
2251 // Operation appears to be iteratively computed (such as an induction variable)
2252 // It is possible for this operation to return false for a loop-varying
2253 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2254 bool Node::is_iteratively_computed() {
2255 if (ideal_reg()) { // does operation have a result register?
2256 for (uint i = 1; i < req(); i++) {
2257 Node* n = in(i);
2258 if (n != NULL && n->is_Phi()) {
2259 for (uint j = 1; j < n->req(); j++) {
2260 if (n->in(j) == this) {
2261 return true;
2262 }
2263 }
2264 }
2265 }
2266 }
2267 return false;
2268 }
2269
2270 //--------------------------find_similar------------------------------
2271 // Return a node with opcode "opc" and same inputs as "this" if one can
2272 // be found; Otherwise return NULL;
2273 Node* Node::find_similar(int opc) {
2274 if (req() >= 2) {
2275 Node* def = in(1);
2276 if (def && def->outcnt() >= 2) {
2277 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2278 Node* use = def->fast_out(i);
2279 if (use->Opcode() == opc &&
2280 use->req() == req()) {
2281 uint j;
2282 for (j = 0; j < use->req(); j++) {
2283 if (use->in(j) != in(j)) {
2284 break;
2285 }
2286 }
2287 if (j == use->req()) {
2288 return use;
2289 }
2290 }
2291 }
2292 }
2293 }
2294 return NULL;
2295 }
2296
2297
2298 //--------------------------unique_ctrl_out------------------------------
2299 // Return the unique control out if only one. Null if none or more than one.
2300 Node* Node::unique_ctrl_out() const {
2301 Node* found = NULL;
2302 for (uint i = 0; i < outcnt(); i++) {
2303 Node* use = raw_out(i);
2304 if (use->is_CFG() && use != this) {
2305 if (found != NULL) return NULL;
2306 found = use;
2307 }
2308 }
2309 return found;
2310 }
2311
2312 void Node::ensure_control_or_add_prec(Node* c) {
2313 if (in(0) == NULL) {
2314 set_req(0, c);
2315 } else if (in(0) != c) {
2316 add_prec(c);
2317 }
2318 }
2319
2320 //=============================================================================
2321 //------------------------------yank-------------------------------------------
2322 // Find and remove
2323 void Node_List::yank( Node *n ) {
2324 uint i;
2325 for( i = 0; i < _cnt; i++ )
2326 if( _nodes[i] == n )
2327 break;
2328
2329 if( i < _cnt )
2330 _nodes[i] = _nodes[--_cnt];
2331 }
2332
2333 //------------------------------dump-------------------------------------------
2334 void Node_List::dump() const {
2335 #ifndef PRODUCT
2336 for( uint i = 0; i < _cnt; i++ )
2337 if( _nodes[i] ) {
2338 tty->print("%5d--> ",i);
2339 _nodes[i]->dump();
2340 }
2341 #endif
2342 }
2343
2344 //=============================================================================
2345 //------------------------------remove-----------------------------------------
2346 void Unique_Node_List::remove( Node *n ) {
2347 if( _in_worklist[n->_idx] ) {
2348 for( uint i = 0; i < size(); i++ )
2349 if( _nodes[i] == n ) {
2350 map(i,Node_List::pop());
2351 _in_worklist >>= n->_idx;
2352 return;
2353 }
2354 ShouldNotReachHere();
2355 }
2356 }
2357
2358 //-----------------------remove_useless_nodes----------------------------------
2359 // Remove useless nodes from worklist
2360 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2361
2362 for( uint i = 0; i < size(); ++i ) {
2363 Node *n = at(i);
2364 assert( n != NULL, "Did not expect null entries in worklist");
2365 if( ! useful.test(n->_idx) ) {
2366 _in_worklist >>= n->_idx;
2367 map(i,Node_List::pop());
2368 // Node *replacement = Node_List::pop();
2369 // if( i != size() ) { // Check if removing last entry
2370 // _nodes[i] = replacement;
2371 // }
2372 --i; // Visit popped node
2373 // If it was last entry, loop terminates since size() was also reduced
2374 }
2375 }
2376 }
2377
2378 //=============================================================================
2379 void Node_Stack::grow() {
2380 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2381 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2382 size_t max = old_max << 1; // max * 2
2383 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2384 _inode_max = _inodes + max;
2385 _inode_top = _inodes + old_top; // restore _top
2386 }
2387
2388 // Node_Stack is used to map nodes.
2389 Node* Node_Stack::find(uint idx) const {
2390 uint sz = size();
2391 for (uint i=0; i < sz; i++) {
2392 if (idx == index_at(i) )
2393 return node_at(i);
2394 }
2395 return NULL;
2396 }
2397
2398 //=============================================================================
2399 uint TypeNode::size_of() const { return sizeof(*this); }
2400 #ifndef PRODUCT
2401 void TypeNode::dump_spec(outputStream *st) const {
2402 if( !Verbose && !WizardMode ) {
2403 // standard dump does this in Verbose and WizardMode
2404 st->print(" #"); _type->dump_on(st);
2405 }
2406 }
2407
2408 void TypeNode::dump_compact_spec(outputStream *st) const {
2409 st->print("#");
2410 _type->dump_on(st);
2411 }
2412 #endif
2413 uint TypeNode::hash() const {
2414 return Node::hash() + _type->hash();
2415 }
2416 uint TypeNode::cmp( const Node &n ) const
2417 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2418 const Type *TypeNode::bottom_type() const { return _type; }
2419 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2420
2421 //------------------------------ideal_reg--------------------------------------
2422 uint TypeNode::ideal_reg() const {
2423 return _type->ideal_reg();
2424 }