1 /*
2 * Copyright (c) 1997, 2021, 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 "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/ad.hpp"
32 #include "opto/callGenerator.hpp"
33 #include "opto/castnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/connode.hpp"
36 #include "opto/loopnode.hpp"
37 #include "opto/machnode.hpp"
38 #include "opto/matcher.hpp"
39 #include "opto/node.hpp"
40 #include "opto/opcodes.hpp"
41 #include "opto/regmask.hpp"
42 #include "opto/rootnode.hpp"
43 #include "opto/type.hpp"
44 #include "utilities/copy.hpp"
45 #include "utilities/macros.hpp"
46 #include "utilities/powerOfTwo.hpp"
47
48 class RegMask;
49 // #include "phase.hpp"
50 class PhaseTransform;
51 class PhaseGVN;
52
53 // Arena we are currently building Nodes in
54 const uint Node::NotAMachineReg = 0xffff0000;
55
56 #ifndef PRODUCT
57 extern int nodes_created;
58 #endif
59 #ifdef __clang__
60 #pragma clang diagnostic push
61 #pragma GCC diagnostic ignored "-Wuninitialized"
62 #endif
63
64 #ifdef ASSERT
65
66 //-------------------------- construct_node------------------------------------
67 // Set a breakpoint here to identify where a particular node index is built.
verify_construction()68 void Node::verify_construction() {
69 _debug_orig = NULL;
70 int old_debug_idx = Compile::debug_idx();
71 int new_debug_idx = old_debug_idx + 1;
72 if (new_debug_idx > 0) {
73 // Arrange that the lowest five decimal digits of _debug_idx
74 // will repeat those of _idx. In case this is somehow pathological,
75 // we continue to assign negative numbers (!) consecutively.
76 const int mod = 100000;
77 int bump = (int)(_idx - new_debug_idx) % mod;
78 if (bump < 0) {
79 bump += mod;
80 }
81 assert(bump >= 0 && bump < mod, "");
82 new_debug_idx += bump;
83 }
84 Compile::set_debug_idx(new_debug_idx);
85 set_debug_idx(new_debug_idx);
86 Compile* C = Compile::current();
87 assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
88 if (!C->phase_optimize_finished()) {
89 // Only check assert during parsing and optimization phase. Skip it while generating code.
90 assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
91 }
92 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
93 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
94 BREAKPOINT;
95 }
96 #if OPTO_DU_ITERATOR_ASSERT
97 _last_del = NULL;
98 _del_tick = 0;
99 #endif
100 _hash_lock = 0;
101 }
102
103
104 // #ifdef ASSERT ...
105
106 #if OPTO_DU_ITERATOR_ASSERT
sample(const Node * node)107 void DUIterator_Common::sample(const Node* node) {
108 _vdui = VerifyDUIterators;
109 _node = node;
110 _outcnt = node->_outcnt;
111 _del_tick = node->_del_tick;
112 _last = NULL;
113 }
114
verify(const Node * node,bool at_end_ok)115 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
116 assert(_node == node, "consistent iterator source");
117 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
118 }
119
verify_resync()120 void DUIterator_Common::verify_resync() {
121 // Ensure that the loop body has just deleted the last guy produced.
122 const Node* node = _node;
123 // Ensure that at least one copy of the last-seen edge was deleted.
124 // Note: It is OK to delete multiple copies of the last-seen edge.
125 // Unfortunately, we have no way to verify that all the deletions delete
126 // that same edge. On this point we must use the Honor System.
127 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
128 assert(node->_last_del == _last, "must have deleted the edge just produced");
129 // We liked this deletion, so accept the resulting outcnt and tick.
130 _outcnt = node->_outcnt;
131 _del_tick = node->_del_tick;
132 }
133
reset(const DUIterator_Common & that)134 void DUIterator_Common::reset(const DUIterator_Common& that) {
135 if (this == &that) return; // ignore assignment to self
136 if (!_vdui) {
137 // We need to initialize everything, overwriting garbage values.
138 _last = that._last;
139 _vdui = that._vdui;
140 }
141 // Note: It is legal (though odd) for an iterator over some node x
142 // to be reassigned to iterate over another node y. Some doubly-nested
143 // progress loops depend on being able to do this.
144 const Node* node = that._node;
145 // Re-initialize everything, except _last.
146 _node = node;
147 _outcnt = node->_outcnt;
148 _del_tick = node->_del_tick;
149 }
150
sample(const Node * node)151 void DUIterator::sample(const Node* node) {
152 DUIterator_Common::sample(node); // Initialize the assertion data.
153 _refresh_tick = 0; // No refreshes have happened, as yet.
154 }
155
verify(const Node * node,bool at_end_ok)156 void DUIterator::verify(const Node* node, bool at_end_ok) {
157 DUIterator_Common::verify(node, at_end_ok);
158 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
159 }
160
verify_increment()161 void DUIterator::verify_increment() {
162 if (_refresh_tick & 1) {
163 // We have refreshed the index during this loop.
164 // Fix up _idx to meet asserts.
165 if (_idx > _outcnt) _idx = _outcnt;
166 }
167 verify(_node, true);
168 }
169
verify_resync()170 void DUIterator::verify_resync() {
171 // Note: We do not assert on _outcnt, because insertions are OK here.
172 DUIterator_Common::verify_resync();
173 // Make sure we are still in sync, possibly with no more out-edges:
174 verify(_node, true);
175 }
176
reset(const DUIterator & that)177 void DUIterator::reset(const DUIterator& that) {
178 if (this == &that) return; // self assignment is always a no-op
179 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
180 assert(that._idx == 0, "assign only the result of Node::outs()");
181 assert(_idx == that._idx, "already assigned _idx");
182 if (!_vdui) {
183 // We need to initialize everything, overwriting garbage values.
184 sample(that._node);
185 } else {
186 DUIterator_Common::reset(that);
187 if (_refresh_tick & 1) {
188 _refresh_tick++; // Clear the "was refreshed" flag.
189 }
190 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
191 }
192 }
193
refresh()194 void DUIterator::refresh() {
195 DUIterator_Common::sample(_node); // Re-fetch assertion data.
196 _refresh_tick |= 1; // Set the "was refreshed" flag.
197 }
198
verify_finish()199 void DUIterator::verify_finish() {
200 // If the loop has killed the node, do not require it to re-run.
201 if (_node->_outcnt == 0) _refresh_tick &= ~1;
202 // If this assert triggers, it means that a loop used refresh_out_pos
203 // to re-synch an iteration index, but the loop did not correctly
204 // re-run itself, using a "while (progress)" construct.
205 // This iterator enforces the rule that you must keep trying the loop
206 // until it "runs clean" without any need for refreshing.
207 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
208 }
209
210
verify(const Node * node,bool at_end_ok)211 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
212 DUIterator_Common::verify(node, at_end_ok);
213 Node** out = node->_out;
214 uint cnt = node->_outcnt;
215 assert(cnt == _outcnt, "no insertions allowed");
216 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
217 // This last check is carefully designed to work for NO_OUT_ARRAY.
218 }
219
verify_limit()220 void DUIterator_Fast::verify_limit() {
221 const Node* node = _node;
222 verify(node, true);
223 assert(_outp == node->_out + node->_outcnt, "limit still correct");
224 }
225
verify_resync()226 void DUIterator_Fast::verify_resync() {
227 const Node* node = _node;
228 if (_outp == node->_out + _outcnt) {
229 // Note that the limit imax, not the pointer i, gets updated with the
230 // exact count of deletions. (For the pointer it's always "--i".)
231 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
232 // This is a limit pointer, with a name like "imax".
233 // Fudge the _last field so that the common assert will be happy.
234 _last = (Node*) node->_last_del;
235 DUIterator_Common::verify_resync();
236 } else {
237 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
238 // A normal internal pointer.
239 DUIterator_Common::verify_resync();
240 // Make sure we are still in sync, possibly with no more out-edges:
241 verify(node, true);
242 }
243 }
244
verify_relimit(uint n)245 void DUIterator_Fast::verify_relimit(uint n) {
246 const Node* node = _node;
247 assert((int)n > 0, "use imax -= n only with a positive count");
248 // This must be a limit pointer, with a name like "imax".
249 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
250 // The reported number of deletions must match what the node saw.
251 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
252 // Fudge the _last field so that the common assert will be happy.
253 _last = (Node*) node->_last_del;
254 DUIterator_Common::verify_resync();
255 }
256
reset(const DUIterator_Fast & that)257 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
258 assert(_outp == that._outp, "already assigned _outp");
259 DUIterator_Common::reset(that);
260 }
261
verify(const Node * node,bool at_end_ok)262 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
263 // at_end_ok means the _outp is allowed to underflow by 1
264 _outp += at_end_ok;
265 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
266 _outp -= at_end_ok;
267 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
268 }
269
verify_limit()270 void DUIterator_Last::verify_limit() {
271 // Do not require the limit address to be resynched.
272 //verify(node, true);
273 assert(_outp == _node->_out, "limit still correct");
274 }
275
verify_step(uint num_edges)276 void DUIterator_Last::verify_step(uint num_edges) {
277 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
278 _outcnt -= num_edges;
279 _del_tick += num_edges;
280 // Make sure we are still in sync, possibly with no more out-edges:
281 const Node* node = _node;
282 verify(node, true);
283 assert(node->_last_del == _last, "must have deleted the edge just produced");
284 }
285
286 #endif //OPTO_DU_ITERATOR_ASSERT
287
288
289 #endif //ASSERT
290
291
292 // This constant used to initialize _out may be any non-null value.
293 // The value NULL is reserved for the top node only.
294 #define NO_OUT_ARRAY ((Node**)-1)
295
296 // Out-of-line code from node constructors.
297 // Executed only when extra debug info. is being passed around.
init_node_notes(Compile * C,int idx,Node_Notes * nn)298 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
299 C->set_node_notes_at(idx, nn);
300 }
301
302 // Shared initialization code.
Init(int req)303 inline int Node::Init(int req) {
304 Compile* C = Compile::current();
305 int idx = C->next_unique();
306 NOT_PRODUCT(_igv_idx = C->next_igv_idx());
307
308 // Allocate memory for the necessary number of edges.
309 if (req > 0) {
310 // Allocate space for _in array to have double alignment.
311 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
312 }
313 // If there are default notes floating around, capture them:
314 Node_Notes* nn = C->default_node_notes();
315 if (nn != NULL) init_node_notes(C, idx, nn);
316
317 // Note: At this point, C is dead,
318 // and we begin to initialize the new Node.
319
320 _cnt = _max = req;
321 _outcnt = _outmax = 0;
322 _class_id = Class_Node;
323 _flags = 0;
324 _out = NO_OUT_ARRAY;
325 return idx;
326 }
327
328 //------------------------------Node-------------------------------------------
329 // Create a Node, with a given number of required edges.
Node(uint req)330 Node::Node(uint req)
331 : _idx(Init(req))
332 #ifdef ASSERT
333 , _parse_idx(_idx)
334 , _indent(0)
335 #endif
336 {
337 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
338 debug_only( verify_construction() );
339 NOT_PRODUCT(nodes_created++);
340 if (req == 0) {
341 _in = NULL;
342 } else {
343 Node** to = _in;
344 for(uint i = 0; i < req; i++) {
345 to[i] = NULL;
346 }
347 }
348 }
349
350 //------------------------------Node-------------------------------------------
Node(Node * n0)351 Node::Node(Node *n0)
352 : _idx(Init(1))
353 #ifdef ASSERT
354 , _parse_idx(_idx)
355 , _indent(0)
356 #endif
357 {
358 debug_only( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 assert( is_not_dead(n0), "can not use dead node");
361 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
362 }
363
364 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1)365 Node::Node(Node *n0, Node *n1)
366 : _idx(Init(2))
367 #ifdef ASSERT
368 , _parse_idx(_idx)
369 , _indent(0)
370 #endif
371 {
372 debug_only( verify_construction() );
373 NOT_PRODUCT(nodes_created++);
374 assert( is_not_dead(n0), "can not use dead node");
375 assert( is_not_dead(n1), "can not use dead node");
376 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
377 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
378 }
379
380 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2)381 Node::Node(Node *n0, Node *n1, Node *n2)
382 : _idx(Init(3))
383 #ifdef ASSERT
384 , _parse_idx(_idx)
385 , _indent(0)
386 #endif
387 {
388 debug_only( verify_construction() );
389 NOT_PRODUCT(nodes_created++);
390 assert( is_not_dead(n0), "can not use dead node");
391 assert( is_not_dead(n1), "can not use dead node");
392 assert( is_not_dead(n2), "can not use dead node");
393 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
394 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
395 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
396 }
397
398 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3)399 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
400 : _idx(Init(4))
401 #ifdef ASSERT
402 , _parse_idx(_idx)
403 , _indent(0)
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 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
413 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
414 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
415 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
416 }
417
418 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3,Node * n4)419 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
420 : _idx(Init(5))
421 #ifdef ASSERT
422 , _parse_idx(_idx)
423 , _indent(0)
424 #endif
425 {
426 debug_only( verify_construction() );
427 NOT_PRODUCT(nodes_created++);
428 assert( is_not_dead(n0), "can not use dead node");
429 assert( is_not_dead(n1), "can not use dead node");
430 assert( is_not_dead(n2), "can not use dead node");
431 assert( is_not_dead(n3), "can not use dead node");
432 assert( is_not_dead(n4), "can not use dead node");
433 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
434 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
435 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
436 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
437 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
438 }
439
440 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3,Node * n4,Node * n5)441 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
442 Node *n4, Node *n5)
443 : _idx(Init(6))
444 #ifdef ASSERT
445 , _parse_idx(_idx)
446 , _indent(0)
447 #endif
448 {
449 debug_only( verify_construction() );
450 NOT_PRODUCT(nodes_created++);
451 assert( is_not_dead(n0), "can not use dead node");
452 assert( is_not_dead(n1), "can not use dead node");
453 assert( is_not_dead(n2), "can not use dead node");
454 assert( is_not_dead(n3), "can not use dead node");
455 assert( is_not_dead(n4), "can not use dead node");
456 assert( is_not_dead(n5), "can not use dead node");
457 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
458 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
459 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
460 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
461 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
462 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
463 }
464
465 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3,Node * n4,Node * n5,Node * n6)466 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
467 Node *n4, Node *n5, Node *n6)
468 : _idx(Init(7))
469 #ifdef ASSERT
470 , _parse_idx(_idx)
471 , _indent(0)
472 #endif
473 {
474 debug_only( verify_construction() );
475 NOT_PRODUCT(nodes_created++);
476 assert( is_not_dead(n0), "can not use dead node");
477 assert( is_not_dead(n1), "can not use dead node");
478 assert( is_not_dead(n2), "can not use dead node");
479 assert( is_not_dead(n3), "can not use dead node");
480 assert( is_not_dead(n4), "can not use dead node");
481 assert( is_not_dead(n5), "can not use dead node");
482 assert( is_not_dead(n6), "can not use dead node");
483 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
484 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
485 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
486 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
487 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
488 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
489 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
490 }
491
492 #ifdef __clang__
493 #pragma clang diagnostic pop
494 #endif
495
496
497 //------------------------------clone------------------------------------------
498 // Clone a Node.
clone() const499 Node *Node::clone() const {
500 Compile* C = Compile::current();
501 uint s = size_of(); // Size of inherited Node
502 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
503 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
504 // Set the new input pointer array
505 n->_in = (Node**)(((char*)n)+s);
506 // Cannot share the old output pointer array, so kill it
507 n->_out = NO_OUT_ARRAY;
508 // And reset the counters to 0
509 n->_outcnt = 0;
510 n->_outmax = 0;
511 // Unlock this guy, since he is not in any hash table.
512 debug_only(n->_hash_lock = 0);
513 // Walk the old node's input list to duplicate its edges
514 uint i;
515 for( i = 0; i < len(); i++ ) {
516 Node *x = in(i);
517 n->_in[i] = x;
518 if (x != NULL) x->add_out(n);
519 }
520 if (is_macro()) {
521 C->add_macro_node(n);
522 }
523 if (is_expensive()) {
524 C->add_expensive_node(n);
525 }
526 if (for_post_loop_opts_igvn()) {
527 // Don't add cloned node to Compile::_for_post_loop_opts_igvn list automatically.
528 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
529 n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
530 }
531 if (n->is_reduction()) {
532 // Do not copy reduction information. This must be explicitly set by the calling code.
533 n->remove_flag(Node::Flag_is_reduction);
534 }
535 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
536 bs->register_potential_barrier_node(n);
537
538 n->set_idx(C->next_unique()); // Get new unique index as well
539 NOT_PRODUCT(n->_igv_idx = C->next_igv_idx());
540 debug_only( n->verify_construction() );
541 NOT_PRODUCT(nodes_created++);
542 // Do not patch over the debug_idx of a clone, because it makes it
543 // impossible to break on the clone's moment of creation.
544 //debug_only( n->set_debug_idx( debug_idx() ) );
545
546 C->copy_node_notes_to(n, (Node*) this);
547
548 // MachNode clone
549 uint nopnds;
550 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
551 MachNode *mach = n->as_Mach();
552 MachNode *mthis = this->as_Mach();
553 // Get address of _opnd_array.
554 // It should be the same offset since it is the clone of this node.
555 MachOper **from = mthis->_opnds;
556 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
557 pointer_delta((const void*)from,
558 (const void*)(&mthis->_opnds), 1));
559 mach->_opnds = to;
560 for ( uint i = 0; i < nopnds; ++i ) {
561 to[i] = from[i]->clone();
562 }
563 }
564 if (n->is_Call()) {
565 // CallGenerator is linked to the original node.
566 CallGenerator* cg = n->as_Call()->generator();
567 if (cg != NULL) {
568 CallGenerator* cloned_cg = cg->with_call_node(n->as_Call());
569 n->as_Call()->set_generator(cloned_cg);
570
571 C->print_inlining_assert_ready();
572 C->print_inlining_move_to(cg);
573 C->print_inlining_update(cloned_cg);
574 }
575 }
576 if (n->is_SafePoint()) {
577 // Scalar replacement and macro expansion might modify the JVMState.
578 // Clone it to make sure it's not shared between SafePointNodes.
579 n->as_SafePoint()->clone_jvms(C);
580 n->as_SafePoint()->clone_replaced_nodes();
581 }
582 return n; // Return the clone
583 }
584
585 //---------------------------setup_is_top--------------------------------------
586 // Call this when changing the top node, to reassert the invariants
587 // required by Node::is_top. See Compile::set_cached_top_node.
setup_is_top()588 void Node::setup_is_top() {
589 if (this == (Node*)Compile::current()->top()) {
590 // This node has just become top. Kill its out array.
591 _outcnt = _outmax = 0;
592 _out = NULL; // marker value for top
593 assert(is_top(), "must be top");
594 } else {
595 if (_out == NULL) _out = NO_OUT_ARRAY;
596 assert(!is_top(), "must not be top");
597 }
598 }
599
600 //------------------------------~Node------------------------------------------
601 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
destruct(PhaseValues * phase)602 void Node::destruct(PhaseValues* phase) {
603 Compile* compile = (phase != NULL) ? phase->C : Compile::current();
604 if (phase != NULL && phase->is_IterGVN()) {
605 phase->is_IterGVN()->_worklist.remove(this);
606 }
607 // If this is the most recently created node, reclaim its index. Otherwise,
608 // record the node as dead to keep liveness information accurate.
609 if ((uint)_idx+1 == compile->unique()) {
610 compile->set_unique(compile->unique()-1);
611 } else {
612 compile->record_dead_node(_idx);
613 }
614 // Clear debug info:
615 Node_Notes* nn = compile->node_notes_at(_idx);
616 if (nn != NULL) nn->clear();
617 // Walk the input array, freeing the corresponding output edges
618 _cnt = _max; // forget req/prec distinction
619 uint i;
620 for( i = 0; i < _max; i++ ) {
621 set_req(i, NULL);
622 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
623 }
624 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
625 // See if the input array was allocated just prior to the object
626 int edge_size = _max*sizeof(void*);
627 int out_edge_size = _outmax*sizeof(void*);
628 char *edge_end = ((char*)_in) + edge_size;
629 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
630 int node_size = size_of();
631
632 // Free the output edge array
633 if (out_edge_size > 0) {
634 compile->node_arena()->Afree(out_array, out_edge_size);
635 }
636
637 // Free the input edge array and the node itself
638 if( edge_end == (char*)this ) {
639 // It was; free the input array and object all in one hit
640 #ifndef ASSERT
641 compile->node_arena()->Afree(_in,edge_size+node_size);
642 #endif
643 } else {
644 // Free just the input array
645 compile->node_arena()->Afree(_in,edge_size);
646
647 // Free just the object
648 #ifndef ASSERT
649 compile->node_arena()->Afree(this,node_size);
650 #endif
651 }
652 if (is_macro()) {
653 compile->remove_macro_node(this);
654 }
655 if (is_expensive()) {
656 compile->remove_expensive_node(this);
657 }
658 if (Opcode() == Op_Opaque4) {
659 compile->remove_skeleton_predicate_opaq(this);
660 }
661 if (for_post_loop_opts_igvn()) {
662 compile->remove_from_post_loop_opts_igvn(this);
663 }
664
665 if (is_SafePoint()) {
666 as_SafePoint()->delete_replaced_nodes();
667 }
668 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
669 bs->unregister_potential_barrier_node(this);
670 #ifdef ASSERT
671 // We will not actually delete the storage, but we'll make the node unusable.
672 *(address*)this = badAddress; // smash the C++ vtbl, probably
673 _in = _out = (Node**) badAddress;
674 _max = _cnt = _outmax = _outcnt = 0;
675 compile->remove_modified_node(this);
676 #endif
677 }
678
679 //------------------------------grow-------------------------------------------
680 // Grow the input array, making space for more edges
grow(uint len)681 void Node::grow(uint len) {
682 Arena* arena = Compile::current()->node_arena();
683 uint new_max = _max;
684 if( new_max == 0 ) {
685 _max = 4;
686 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
687 Node** to = _in;
688 to[0] = NULL;
689 to[1] = NULL;
690 to[2] = NULL;
691 to[3] = NULL;
692 return;
693 }
694 new_max = next_power_of_2(len);
695 // Trimming to limit allows a uint8 to handle up to 255 edges.
696 // Previously I was using only powers-of-2 which peaked at 128 edges.
697 //if( new_max >= limit ) new_max = limit-1;
698 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
699 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
700 _max = new_max; // Record new max length
701 // This assertion makes sure that Node::_max is wide enough to
702 // represent the numerical value of new_max.
703 assert(_max == new_max && _max > len, "int width of _max is too small");
704 }
705
706 //-----------------------------out_grow----------------------------------------
707 // Grow the input array, making space for more edges
out_grow(uint len)708 void Node::out_grow( uint len ) {
709 assert(!is_top(), "cannot grow a top node's out array");
710 Arena* arena = Compile::current()->node_arena();
711 uint new_max = _outmax;
712 if( new_max == 0 ) {
713 _outmax = 4;
714 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
715 return;
716 }
717 new_max = next_power_of_2(len);
718 // Trimming to limit allows a uint8 to handle up to 255 edges.
719 // Previously I was using only powers-of-2 which peaked at 128 edges.
720 //if( new_max >= limit ) new_max = limit-1;
721 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
722 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
723 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
724 _outmax = new_max; // Record new max length
725 // This assertion makes sure that Node::_max is wide enough to
726 // represent the numerical value of new_max.
727 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
728 }
729
730 #ifdef ASSERT
731 //------------------------------is_dead----------------------------------------
is_dead() const732 bool Node::is_dead() const {
733 // Mach and pinch point nodes may look like dead.
734 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
735 return false;
736 for( uint i = 0; i < _max; i++ )
737 if( _in[i] != NULL )
738 return false;
739 dump();
740 return true;
741 }
742
is_reachable_from_root() const743 bool Node::is_reachable_from_root() const {
744 ResourceMark rm;
745 Unique_Node_List wq;
746 wq.push((Node*)this);
747 RootNode* root = Compile::current()->root();
748 for (uint i = 0; i < wq.size(); i++) {
749 Node* m = wq.at(i);
750 if (m == root) {
751 return true;
752 }
753 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
754 Node* u = m->fast_out(j);
755 wq.push(u);
756 }
757 }
758 return false;
759 }
760 #endif
761
762 //------------------------------is_unreachable---------------------------------
is_unreachable(PhaseIterGVN & igvn) const763 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
764 assert(!is_Mach(), "doesn't work with MachNodes");
765 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != NULL && in(0)->is_top());
766 }
767
768 //------------------------------add_req----------------------------------------
769 // Add a new required input at the end
add_req(Node * n)770 void Node::add_req( Node *n ) {
771 assert( is_not_dead(n), "can not use dead node");
772
773 // Look to see if I can move precedence down one without reallocating
774 if( (_cnt >= _max) || (in(_max-1) != NULL) )
775 grow( _max+1 );
776
777 // Find a precedence edge to move
778 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
779 uint i;
780 for( i=_cnt; i<_max; i++ )
781 if( in(i) == NULL ) // Find the NULL at end of prec edge list
782 break; // There must be one, since we grew the array
783 _in[i] = in(_cnt); // Move prec over, making space for req edge
784 }
785 _in[_cnt++] = n; // Stuff over old prec edge
786 if (n != NULL) n->add_out((Node *)this);
787 }
788
789 //---------------------------add_req_batch-------------------------------------
790 // Add a new required input at the end
add_req_batch(Node * n,uint m)791 void Node::add_req_batch( Node *n, uint m ) {
792 assert( is_not_dead(n), "can not use dead node");
793 // check various edge cases
794 if ((int)m <= 1) {
795 assert((int)m >= 0, "oob");
796 if (m != 0) add_req(n);
797 return;
798 }
799
800 // Look to see if I can move precedence down one without reallocating
801 if( (_cnt+m) > _max || _in[_max-m] )
802 grow( _max+m );
803
804 // Find a precedence edge to move
805 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
806 uint i;
807 for( i=_cnt; i<_max; i++ )
808 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
809 break; // There must be one, since we grew the array
810 // Slide all the precs over by m positions (assume #prec << m).
811 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
812 }
813
814 // Stuff over the old prec edges
815 for(uint i=0; i<m; i++ ) {
816 _in[_cnt++] = n;
817 }
818
819 // Insert multiple out edges on the node.
820 if (n != NULL && !n->is_top()) {
821 for(uint i=0; i<m; i++ ) {
822 n->add_out((Node *)this);
823 }
824 }
825 }
826
827 //------------------------------del_req----------------------------------------
828 // Delete the required edge and compact the edge array
del_req(uint idx)829 void Node::del_req( uint idx ) {
830 assert( idx < _cnt, "oob");
831 assert( !VerifyHashTableKeys || _hash_lock == 0,
832 "remove node from hash table before modifying it");
833 // First remove corresponding def-use edge
834 Node *n = in(idx);
835 if (n != NULL) n->del_out((Node *)this);
836 _in[idx] = in(--_cnt); // Compact the array
837 // Avoid spec violation: Gap in prec edges.
838 close_prec_gap_at(_cnt);
839 Compile::current()->record_modified_node(this);
840 }
841
842 //------------------------------del_req_ordered--------------------------------
843 // Delete the required edge and compact the edge array with preserved order
del_req_ordered(uint idx)844 void Node::del_req_ordered( uint idx ) {
845 assert( idx < _cnt, "oob");
846 assert( !VerifyHashTableKeys || _hash_lock == 0,
847 "remove node from hash table before modifying it");
848 // First remove corresponding def-use edge
849 Node *n = in(idx);
850 if (n != NULL) n->del_out((Node *)this);
851 if (idx < --_cnt) { // Not last edge ?
852 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
853 }
854 // Avoid spec violation: Gap in prec edges.
855 close_prec_gap_at(_cnt);
856 Compile::current()->record_modified_node(this);
857 }
858
859 //------------------------------ins_req----------------------------------------
860 // Insert a new required input at the end
ins_req(uint idx,Node * n)861 void Node::ins_req( uint idx, Node *n ) {
862 assert( is_not_dead(n), "can not use dead node");
863 add_req(NULL); // Make space
864 assert( idx < _max, "Must have allocated enough space");
865 // Slide over
866 if(_cnt-idx-1 > 0) {
867 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
868 }
869 _in[idx] = n; // Stuff over old required edge
870 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
871 }
872
873 //-----------------------------find_edge---------------------------------------
find_edge(Node * n)874 int Node::find_edge(Node* n) {
875 for (uint i = 0; i < len(); i++) {
876 if (_in[i] == n) return i;
877 }
878 return -1;
879 }
880
881 //----------------------------replace_edge-------------------------------------
replace_edge(Node * old,Node * neww,PhaseGVN * gvn)882 int Node::replace_edge(Node* old, Node* neww, PhaseGVN* gvn) {
883 if (old == neww) return 0; // nothing to do
884 uint nrep = 0;
885 for (uint i = 0; i < len(); i++) {
886 if (in(i) == old) {
887 if (i < req()) {
888 if (gvn != NULL) {
889 set_req_X(i, neww, gvn);
890 } else {
891 set_req(i, neww);
892 }
893 } else {
894 assert(gvn == NULL || gvn->is_IterGVN() == NULL, "no support for igvn here");
895 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
896 set_prec(i, neww);
897 }
898 nrep++;
899 }
900 }
901 return nrep;
902 }
903
904 /**
905 * Replace input edges in the range pointing to 'old' node.
906 */
replace_edges_in_range(Node * old,Node * neww,int start,int end,PhaseGVN * gvn)907 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn) {
908 if (old == neww) return 0; // nothing to do
909 uint nrep = 0;
910 for (int i = start; i < end; i++) {
911 if (in(i) == old) {
912 set_req_X(i, neww, gvn);
913 nrep++;
914 }
915 }
916 return nrep;
917 }
918
919 //-------------------------disconnect_inputs-----------------------------------
920 // NULL out all inputs to eliminate incoming Def-Use edges.
disconnect_inputs(Compile * C)921 void Node::disconnect_inputs(Compile* C) {
922 // the layout of Node::_in
923 // r: a required input, null is allowed
924 // p: a precedence, null values are all at the end
925 // -----------------------------------
926 // |r|...|r|p|...|p|null|...|null|
927 // | |
928 // req() len()
929 // -----------------------------------
930 for (uint i = 0; i < req(); ++i) {
931 if (in(i) != nullptr) {
932 set_req(i, nullptr);
933 }
934 }
935
936 // Remove precedence edges if any exist
937 // Note: Safepoints may have precedence edges, even during parsing
938 for (uint i = len(); i > req(); ) {
939 rm_prec(--i); // no-op if _in[i] is nullptr
940 }
941
942 #ifdef ASSERT
943 // sanity check
944 for (uint i = 0; i < len(); ++i) {
945 assert(_in[i] == nullptr, "disconnect_inputs() failed!");
946 }
947 #endif
948
949 // Node::destruct requires all out edges be deleted first
950 // debug_only(destruct();) // no reuse benefit expected
951 C->record_dead_node(_idx);
952 }
953
954 //-----------------------------uncast---------------------------------------
955 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
956 // Strip away casting. (It is depth-limited.)
957 // Optionally, keep casts with dependencies.
uncast(bool keep_deps) const958 Node* Node::uncast(bool keep_deps) const {
959 // Should be inline:
960 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
961 if (is_ConstraintCast()) {
962 return uncast_helper(this, keep_deps);
963 } else {
964 return (Node*) this;
965 }
966 }
967
968 // Find out of current node that matches opcode.
find_out_with(int opcode)969 Node* Node::find_out_with(int opcode) {
970 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
971 Node* use = fast_out(i);
972 if (use->Opcode() == opcode) {
973 return use;
974 }
975 }
976 return NULL;
977 }
978
979 // Return true if the current node has an out that matches opcode.
has_out_with(int opcode)980 bool Node::has_out_with(int opcode) {
981 return (find_out_with(opcode) != NULL);
982 }
983
984 // Return true if the current node has an out that matches any of the opcodes.
has_out_with(int opcode1,int opcode2,int opcode3,int opcode4)985 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
986 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
987 int opcode = fast_out(i)->Opcode();
988 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
989 return true;
990 }
991 }
992 return false;
993 }
994
995
996 //---------------------------uncast_helper-------------------------------------
uncast_helper(const Node * p,bool keep_deps)997 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
998 #ifdef ASSERT
999 uint depth_count = 0;
1000 const Node* orig_p = p;
1001 #endif
1002
1003 while (true) {
1004 #ifdef ASSERT
1005 if (depth_count >= K) {
1006 orig_p->dump(4);
1007 if (p != orig_p)
1008 p->dump(1);
1009 }
1010 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
1011 #endif
1012 if (p == NULL || p->req() != 2) {
1013 break;
1014 } else if (p->is_ConstraintCast()) {
1015 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
1016 break; // stop at casts with dependencies
1017 }
1018 p = p->in(1);
1019 } else {
1020 break;
1021 }
1022 }
1023 return (Node*) p;
1024 }
1025
1026 //------------------------------add_prec---------------------------------------
1027 // Add a new precedence input. Precedence inputs are unordered, with
1028 // duplicates removed and NULLs packed down at the end.
add_prec(Node * n)1029 void Node::add_prec( Node *n ) {
1030 assert( is_not_dead(n), "can not use dead node");
1031
1032 // Check for NULL at end
1033 if( _cnt >= _max || in(_max-1) )
1034 grow( _max+1 );
1035
1036 // Find a precedence edge to move
1037 uint i = _cnt;
1038 while( in(i) != NULL ) {
1039 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1040 i++;
1041 }
1042 _in[i] = n; // Stuff prec edge over NULL
1043 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
1044
1045 #ifdef ASSERT
1046 while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
1047 #endif
1048 }
1049
1050 //------------------------------rm_prec----------------------------------------
1051 // Remove a precedence input. Precedence inputs are unordered, with
1052 // duplicates removed and NULLs packed down at the end.
rm_prec(uint j)1053 void Node::rm_prec( uint j ) {
1054 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1055 assert(j >= _cnt, "not a precedence edge");
1056 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
1057 _in[j]->del_out((Node *)this);
1058 close_prec_gap_at(j);
1059 }
1060
1061 //------------------------------size_of----------------------------------------
size_of() const1062 uint Node::size_of() const { return sizeof(*this); }
1063
1064 //------------------------------ideal_reg--------------------------------------
ideal_reg() const1065 uint Node::ideal_reg() const { return 0; }
1066
1067 //------------------------------jvms-------------------------------------------
jvms() const1068 JVMState* Node::jvms() const { return NULL; }
1069
1070 #ifdef ASSERT
1071 //------------------------------jvms-------------------------------------------
verify_jvms(const JVMState * using_jvms) const1072 bool Node::verify_jvms(const JVMState* using_jvms) const {
1073 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1074 if (jvms == using_jvms) return true;
1075 }
1076 return false;
1077 }
1078
1079 //------------------------------init_NodeProperty------------------------------
init_NodeProperty()1080 void Node::init_NodeProperty() {
1081 assert(_max_classes <= max_juint, "too many NodeProperty classes");
1082 assert(max_flags() <= max_juint, "too many NodeProperty flags");
1083 }
1084
1085 //-----------------------------max_flags---------------------------------------
max_flags()1086 juint Node::max_flags() {
1087 return (PD::_last_flag << 1) - 1; // allow flags combination
1088 }
1089 #endif
1090
1091 //------------------------------format-----------------------------------------
1092 // Print as assembly
format(PhaseRegAlloc *,outputStream * st) const1093 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1094 //------------------------------emit-------------------------------------------
1095 // Emit bytes starting at parameter 'ptr'.
emit(CodeBuffer & cbuf,PhaseRegAlloc * ra_) const1096 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1097 //------------------------------size-------------------------------------------
1098 // Size of instruction in bytes
size(PhaseRegAlloc * ra_) const1099 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1100
1101 //------------------------------CFG Construction-------------------------------
1102 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1103 // Goto and Return.
is_block_proj() const1104 const Node *Node::is_block_proj() const { return 0; }
1105
1106 // Minimum guaranteed type
bottom_type() const1107 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1108
1109
1110 //------------------------------raise_bottom_type------------------------------
1111 // Get the worst-case Type output for this Node.
raise_bottom_type(const Type * new_type)1112 void Node::raise_bottom_type(const Type* new_type) {
1113 if (is_Type()) {
1114 TypeNode *n = this->as_Type();
1115 if (VerifyAliases) {
1116 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1117 }
1118 n->set_type(new_type);
1119 } else if (is_Load()) {
1120 LoadNode *n = this->as_Load();
1121 if (VerifyAliases) {
1122 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1123 }
1124 n->set_type(new_type);
1125 }
1126 }
1127
1128 //------------------------------Identity---------------------------------------
1129 // Return a node that the given node is equivalent to.
Identity(PhaseGVN * phase)1130 Node* Node::Identity(PhaseGVN* phase) {
1131 return this; // Default to no identities
1132 }
1133
1134 //------------------------------Value------------------------------------------
1135 // Compute a new Type for a node using the Type of the inputs.
Value(PhaseGVN * phase) const1136 const Type* Node::Value(PhaseGVN* phase) const {
1137 return bottom_type(); // Default to worst-case Type
1138 }
1139
1140 //------------------------------Ideal------------------------------------------
1141 //
1142 // 'Idealize' the graph rooted at this Node.
1143 //
1144 // In order to be efficient and flexible there are some subtle invariants
1145 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1146 // these invariants, although its too slow to have on by default. If you are
1147 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1148 //
1149 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1150 // pointer. If ANY change is made, it must return the root of the reshaped
1151 // graph - even if the root is the same Node. Example: swapping the inputs
1152 // to an AddINode gives the same answer and same root, but you still have to
1153 // return the 'this' pointer instead of NULL.
1154 //
1155 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1156 // Identity call to return an old Node; basically if Identity can find
1157 // another Node have the Ideal call make no change and return NULL.
1158 // Example: AddINode::Ideal must check for add of zero; in this case it
1159 // returns NULL instead of doing any graph reshaping.
1160 //
1161 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1162 // sharing there may be other users of the old Nodes relying on their current
1163 // semantics. Modifying them will break the other users.
1164 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1165 // "X+3" unchanged in case it is shared.
1166 //
1167 // If you modify the 'this' pointer's inputs, you should use
1168 // 'set_req'. If you are making a new Node (either as the new root or
1169 // some new internal piece) you may use 'init_req' to set the initial
1170 // value. You can make a new Node with either 'new' or 'clone'. In
1171 // either case, def-use info is correctly maintained.
1172 //
1173 // Example: reshape "(X+3)+4" into "X+7":
1174 // set_req(1, in(1)->in(1));
1175 // set_req(2, phase->intcon(7));
1176 // return this;
1177 // Example: reshape "X*4" into "X<<2"
1178 // return new LShiftINode(in(1), phase->intcon(2));
1179 //
1180 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1181 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1182 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1183 // return new AddINode(shift, in(1));
1184 //
1185 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1186 // These forms are faster than 'phase->transform(new ConNode())' and Do
1187 // The Right Thing with def-use info.
1188 //
1189 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1190 // graph uses the 'this' Node it must be the root. If you want a Node with
1191 // the same Opcode as the 'this' pointer use 'clone'.
1192 //
Ideal(PhaseGVN * phase,bool can_reshape)1193 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1194 return NULL; // Default to being Ideal already
1195 }
1196
1197 // Some nodes have specific Ideal subgraph transformations only if they are
1198 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1199 // for the transformations to happen.
has_special_unique_user() const1200 bool Node::has_special_unique_user() const {
1201 assert(outcnt() == 1, "match only for unique out");
1202 Node* n = unique_out();
1203 int op = Opcode();
1204 if (this->is_Store()) {
1205 // Condition for back-to-back stores folding.
1206 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1207 } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1208 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1209 return n->Opcode() == Op_MemBarAcquire;
1210 } else if (op == Op_AddL) {
1211 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1212 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1213 } else if (op == Op_SubI || op == Op_SubL) {
1214 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1215 return n->Opcode() == op && n->in(2) == this;
1216 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1217 // See IfProjNode::Identity()
1218 return true;
1219 } else {
1220 return false;
1221 }
1222 };
1223
1224 //--------------------------find_exact_control---------------------------------
1225 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
find_exact_control(Node * ctrl)1226 Node* Node::find_exact_control(Node* ctrl) {
1227 if (ctrl == NULL && this->is_Region())
1228 ctrl = this->as_Region()->is_copy();
1229
1230 if (ctrl != NULL && ctrl->is_CatchProj()) {
1231 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1232 ctrl = ctrl->in(0);
1233 if (ctrl != NULL && !ctrl->is_top())
1234 ctrl = ctrl->in(0);
1235 }
1236
1237 if (ctrl != NULL && ctrl->is_Proj())
1238 ctrl = ctrl->in(0);
1239
1240 return ctrl;
1241 }
1242
1243 //--------------------------dominates------------------------------------------
1244 // Helper function for MemNode::all_controls_dominate().
1245 // Check if 'this' control node dominates or equal to 'sub' control node.
1246 // We already know that if any path back to Root or Start reaches 'this',
1247 // then all paths so, so this is a simple search for one example,
1248 // not an exhaustive search for a counterexample.
dominates(Node * sub,Node_List & nlist)1249 bool Node::dominates(Node* sub, Node_List &nlist) {
1250 assert(this->is_CFG(), "expecting control");
1251 assert(sub != NULL && sub->is_CFG(), "expecting control");
1252
1253 // detect dead cycle without regions
1254 int iterations_without_region_limit = DominatorSearchLimit;
1255
1256 Node* orig_sub = sub;
1257 Node* dom = this;
1258 bool met_dom = false;
1259 nlist.clear();
1260
1261 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1262 // After seeing 'dom', continue up to Root or Start.
1263 // If we hit a region (backward split point), it may be a loop head.
1264 // Keep going through one of the region's inputs. If we reach the
1265 // same region again, go through a different input. Eventually we
1266 // will either exit through the loop head, or give up.
1267 // (If we get confused, break out and return a conservative 'false'.)
1268 while (sub != NULL) {
1269 if (sub->is_top()) break; // Conservative answer for dead code.
1270 if (sub == dom) {
1271 if (nlist.size() == 0) {
1272 // No Region nodes except loops were visited before and the EntryControl
1273 // path was taken for loops: it did not walk in a cycle.
1274 return true;
1275 } else if (met_dom) {
1276 break; // already met before: walk in a cycle
1277 } else {
1278 // Region nodes were visited. Continue walk up to Start or Root
1279 // to make sure that it did not walk in a cycle.
1280 met_dom = true; // first time meet
1281 iterations_without_region_limit = DominatorSearchLimit; // Reset
1282 }
1283 }
1284 if (sub->is_Start() || sub->is_Root()) {
1285 // Success if we met 'dom' along a path to Start or Root.
1286 // We assume there are no alternative paths that avoid 'dom'.
1287 // (This assumption is up to the caller to ensure!)
1288 return met_dom;
1289 }
1290 Node* up = sub->in(0);
1291 // Normalize simple pass-through regions and projections:
1292 up = sub->find_exact_control(up);
1293 // If sub == up, we found a self-loop. Try to push past it.
1294 if (sub == up && sub->is_Loop()) {
1295 // Take loop entry path on the way up to 'dom'.
1296 up = sub->in(1); // in(LoopNode::EntryControl);
1297 } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1298 // Take in(1) path on the way up to 'dom' for regions with only one input
1299 up = sub->in(1);
1300 } else if (sub == up && sub->is_Region() && sub->req() == 3) {
1301 // Try both paths for Regions with 2 input paths (it may be a loop head).
1302 // It could give conservative 'false' answer without information
1303 // which region's input is the entry path.
1304 iterations_without_region_limit = DominatorSearchLimit; // Reset
1305
1306 bool region_was_visited_before = false;
1307 // Was this Region node visited before?
1308 // If so, we have reached it because we accidentally took a
1309 // loop-back edge from 'sub' back into the body of the loop,
1310 // and worked our way up again to the loop header 'sub'.
1311 // So, take the first unexplored path on the way up to 'dom'.
1312 for (int j = nlist.size() - 1; j >= 0; j--) {
1313 intptr_t ni = (intptr_t)nlist.at(j);
1314 Node* visited = (Node*)(ni & ~1);
1315 bool visited_twice_already = ((ni & 1) != 0);
1316 if (visited == sub) {
1317 if (visited_twice_already) {
1318 // Visited 2 paths, but still stuck in loop body. Give up.
1319 return false;
1320 }
1321 // The Region node was visited before only once.
1322 // (We will repush with the low bit set, below.)
1323 nlist.remove(j);
1324 // We will find a new edge and re-insert.
1325 region_was_visited_before = true;
1326 break;
1327 }
1328 }
1329
1330 // Find an incoming edge which has not been seen yet; walk through it.
1331 assert(up == sub, "");
1332 uint skip = region_was_visited_before ? 1 : 0;
1333 for (uint i = 1; i < sub->req(); i++) {
1334 Node* in = sub->in(i);
1335 if (in != NULL && !in->is_top() && in != sub) {
1336 if (skip == 0) {
1337 up = in;
1338 break;
1339 }
1340 --skip; // skip this nontrivial input
1341 }
1342 }
1343
1344 // Set 0 bit to indicate that both paths were taken.
1345 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1346 }
1347
1348 if (up == sub) {
1349 break; // some kind of tight cycle
1350 }
1351 if (up == orig_sub && met_dom) {
1352 // returned back after visiting 'dom'
1353 break; // some kind of cycle
1354 }
1355 if (--iterations_without_region_limit < 0) {
1356 break; // dead cycle
1357 }
1358 sub = up;
1359 }
1360
1361 // Did not meet Root or Start node in pred. chain.
1362 // Conservative answer for dead code.
1363 return false;
1364 }
1365
1366 //------------------------------remove_dead_region-----------------------------
1367 // This control node is dead. Follow the subgraph below it making everything
1368 // using it dead as well. This will happen normally via the usual IterGVN
1369 // worklist but this call is more efficient. Do not update use-def info
1370 // inside the dead region, just at the borders.
kill_dead_code(Node * dead,PhaseIterGVN * igvn)1371 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1372 // Con's are a popular node to re-hit in the hash table again.
1373 if( dead->is_Con() ) return;
1374
1375 ResourceMark rm;
1376 Node_List nstack;
1377
1378 Node *top = igvn->C->top();
1379 nstack.push(dead);
1380 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1381
1382 while (nstack.size() > 0) {
1383 dead = nstack.pop();
1384 if (dead->Opcode() == Op_SafePoint) {
1385 dead->as_SafePoint()->disconnect_from_root(igvn);
1386 }
1387 if (dead->outcnt() > 0) {
1388 // Keep dead node on stack until all uses are processed.
1389 nstack.push(dead);
1390 // For all Users of the Dead... ;-)
1391 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1392 Node* use = dead->last_out(k);
1393 igvn->hash_delete(use); // Yank from hash table prior to mod
1394 if (use->in(0) == dead) { // Found another dead node
1395 assert (!use->is_Con(), "Control for Con node should be Root node.");
1396 use->set_req(0, top); // Cut dead edge to prevent processing
1397 nstack.push(use); // the dead node again.
1398 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1399 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1400 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1401 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1402 use->set_req(0, top); // Cut self edge
1403 nstack.push(use);
1404 } else { // Else found a not-dead user
1405 // Dead if all inputs are top or null
1406 bool dead_use = !use->is_Root(); // Keep empty graph alive
1407 for (uint j = 1; j < use->req(); j++) {
1408 Node* in = use->in(j);
1409 if (in == dead) { // Turn all dead inputs into TOP
1410 use->set_req(j, top);
1411 } else if (in != NULL && !in->is_top()) {
1412 dead_use = false;
1413 }
1414 }
1415 if (dead_use) {
1416 if (use->is_Region()) {
1417 use->set_req(0, top); // Cut self edge
1418 }
1419 nstack.push(use);
1420 } else {
1421 igvn->_worklist.push(use);
1422 }
1423 }
1424 // Refresh the iterator, since any number of kills might have happened.
1425 k = dead->last_outs(kmin);
1426 }
1427 } else { // (dead->outcnt() == 0)
1428 // Done with outputs.
1429 igvn->hash_delete(dead);
1430 igvn->_worklist.remove(dead);
1431 igvn->set_type(dead, Type::TOP);
1432 // Kill all inputs to the dead guy
1433 for (uint i=0; i < dead->req(); i++) {
1434 Node *n = dead->in(i); // Get input to dead guy
1435 if (n != NULL && !n->is_top()) { // Input is valid?
1436 dead->set_req(i, top); // Smash input away
1437 if (n->outcnt() == 0) { // Input also goes dead?
1438 if (!n->is_Con())
1439 nstack.push(n); // Clear it out as well
1440 } else if (n->outcnt() == 1 &&
1441 n->has_special_unique_user()) {
1442 igvn->add_users_to_worklist( n );
1443 } else if (n->outcnt() <= 2 && n->is_Store()) {
1444 // Push store's uses on worklist to enable folding optimization for
1445 // store/store and store/load to the same address.
1446 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1447 // and remove_globally_dead_node().
1448 igvn->add_users_to_worklist( n );
1449 } else {
1450 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1451 }
1452 }
1453 }
1454 igvn->C->remove_useless_node(dead);
1455 } // (dead->outcnt() == 0)
1456 } // while (nstack.size() > 0) for outputs
1457 return;
1458 }
1459
1460 //------------------------------remove_dead_region-----------------------------
remove_dead_region(PhaseGVN * phase,bool can_reshape)1461 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1462 Node *n = in(0);
1463 if( !n ) return false;
1464 // Lost control into this guy? I.e., it became unreachable?
1465 // Aggressively kill all unreachable code.
1466 if (can_reshape && n->is_top()) {
1467 kill_dead_code(this, phase->is_IterGVN());
1468 return false; // Node is dead.
1469 }
1470
1471 if( n->is_Region() && n->as_Region()->is_copy() ) {
1472 Node *m = n->nonnull_req();
1473 set_req(0, m);
1474 return true;
1475 }
1476 return false;
1477 }
1478
1479 //------------------------------hash-------------------------------------------
1480 // Hash function over Nodes.
hash() const1481 uint Node::hash() const {
1482 uint sum = 0;
1483 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1484 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1485 return (sum>>2) + _cnt + Opcode();
1486 }
1487
1488 //------------------------------cmp--------------------------------------------
1489 // Compare special parts of simple Nodes
cmp(const Node & n) const1490 bool Node::cmp( const Node &n ) const {
1491 return true; // Must be same
1492 }
1493
1494 //------------------------------rematerialize-----------------------------------
1495 // Should we clone rather than spill this instruction?
rematerialize() const1496 bool Node::rematerialize() const {
1497 if ( is_Mach() )
1498 return this->as_Mach()->rematerialize();
1499 else
1500 return (_flags & Flag_rematerialize) != 0;
1501 }
1502
1503 //------------------------------needs_anti_dependence_check---------------------
1504 // Nodes which use memory without consuming it, hence need antidependences.
needs_anti_dependence_check() const1505 bool Node::needs_anti_dependence_check() const {
1506 if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1507 return false;
1508 }
1509 return in(1)->bottom_type()->has_memory();
1510 }
1511
1512 // Get an integer constant from a ConNode (or CastIINode).
1513 // Return a default value if there is no apparent constant here.
find_int_type() const1514 const TypeInt* Node::find_int_type() const {
1515 if (this->is_Type()) {
1516 return this->as_Type()->type()->isa_int();
1517 } else if (this->is_Con()) {
1518 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1519 return this->bottom_type()->isa_int();
1520 }
1521 return NULL;
1522 }
1523
find_integer_type(BasicType bt) const1524 const TypeInteger* Node::find_integer_type(BasicType bt) const {
1525 if (this->is_Type()) {
1526 return this->as_Type()->type()->isa_integer(bt);
1527 } else if (this->is_Con()) {
1528 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1529 return this->bottom_type()->isa_integer(bt);
1530 }
1531 return NULL;
1532 }
1533
1534 // Get a pointer constant from a ConstNode.
1535 // Returns the constant if it is a pointer ConstNode
get_ptr() const1536 intptr_t Node::get_ptr() const {
1537 assert( Opcode() == Op_ConP, "" );
1538 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1539 }
1540
1541 // Get a narrow oop constant from a ConNNode.
get_narrowcon() const1542 intptr_t Node::get_narrowcon() const {
1543 assert( Opcode() == Op_ConN, "" );
1544 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1545 }
1546
1547 // Get a long constant from a ConNode.
1548 // Return a default value if there is no apparent constant here.
find_long_type() const1549 const TypeLong* Node::find_long_type() const {
1550 if (this->is_Type()) {
1551 return this->as_Type()->type()->isa_long();
1552 } else if (this->is_Con()) {
1553 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1554 return this->bottom_type()->isa_long();
1555 }
1556 return NULL;
1557 }
1558
1559
1560 /**
1561 * Return a ptr type for nodes which should have it.
1562 */
get_ptr_type() const1563 const TypePtr* Node::get_ptr_type() const {
1564 const TypePtr* tp = this->bottom_type()->make_ptr();
1565 #ifdef ASSERT
1566 if (tp == NULL) {
1567 this->dump(1);
1568 assert((tp != NULL), "unexpected node type");
1569 }
1570 #endif
1571 return tp;
1572 }
1573
1574 // Get a double constant from a ConstNode.
1575 // Returns the constant if it is a double ConstNode
getd() const1576 jdouble Node::getd() const {
1577 assert( Opcode() == Op_ConD, "" );
1578 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1579 }
1580
1581 // Get a float constant from a ConstNode.
1582 // Returns the constant if it is a float ConstNode
getf() const1583 jfloat Node::getf() const {
1584 assert( Opcode() == Op_ConF, "" );
1585 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1586 }
1587
1588 #ifndef PRODUCT
1589
1590 // Call this from debugger:
find_node(Node * n,const int idx)1591 Node* find_node(Node* n, const int idx) {
1592 return n->find(idx);
1593 }
1594
1595 // Call this from debugger with root node as default:
find_node(const int idx)1596 Node* find_node(const int idx) {
1597 return Compile::current()->root()->find(idx);
1598 }
1599
1600 // Call this from debugger:
find_ctrl(Node * n,const int idx)1601 Node* find_ctrl(Node* n, const int idx) {
1602 return n->find_ctrl(idx);
1603 }
1604
1605 // Call this from debugger with root node as default:
find_ctrl(const int idx)1606 Node* find_ctrl(const int idx) {
1607 return Compile::current()->root()->find_ctrl(idx);
1608 }
1609
1610 //------------------------------find_ctrl--------------------------------------
1611 // Find an ancestor to this node in the control history with given _idx
find_ctrl(int idx)1612 Node* Node::find_ctrl(int idx) {
1613 return find(idx, true);
1614 }
1615
1616 //------------------------------find-------------------------------------------
1617 // Tries to find the node with the index |idx| starting from this node. If idx is negative,
1618 // the search also includes forward (out) edges. Returns NULL if not found.
1619 // If only_ctrl is set, the search will only be done on control nodes. Returns NULL if
1620 // not found or if the node to be found is not a control node (search will not find it).
find(const int idx,bool only_ctrl)1621 Node* Node::find(const int idx, bool only_ctrl) {
1622 ResourceMark rm;
1623 VectorSet old_space;
1624 VectorSet new_space;
1625 Node_List worklist;
1626 Arena* old_arena = Compile::current()->old_arena();
1627 add_to_worklist(this, &worklist, old_arena, &old_space, &new_space);
1628 Node* result = NULL;
1629 int node_idx = (idx >= 0) ? idx : -idx;
1630
1631 for (uint list_index = 0; list_index < worklist.size(); list_index++) {
1632 Node* n = worklist[list_index];
1633
1634 if ((int)n->_idx == node_idx debug_only(|| n->debug_idx() == node_idx)) {
1635 if (result != NULL) {
1636 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1637 (uintptr_t)result, (uintptr_t)n, node_idx);
1638 }
1639 result = n;
1640 }
1641
1642 for (uint i = 0; i < n->len(); i++) {
1643 if (!only_ctrl || n->is_Region() || (n->Opcode() == Op_Root) || (i == TypeFunc::Control)) {
1644 // If only_ctrl is set: Add regions, the root node, or control inputs only
1645 add_to_worklist(n->in(i), &worklist, old_arena, &old_space, &new_space);
1646 }
1647 }
1648
1649 // Also search along forward edges if idx is negative and the search is not done on control nodes only
1650 if (idx < 0 && !only_ctrl) {
1651 for (uint i = 0; i < n->outcnt(); i++) {
1652 add_to_worklist(n->raw_out(i), &worklist, old_arena, &old_space, &new_space);
1653 }
1654 }
1655 #ifdef ASSERT
1656 // Search along debug_orig edges last
1657 Node* orig = n->debug_orig();
1658 while (orig != NULL && add_to_worklist(orig, &worklist, old_arena, &old_space, &new_space)) {
1659 orig = orig->debug_orig();
1660 }
1661 #endif // ASSERT
1662 }
1663 return result;
1664 }
1665
add_to_worklist(Node * n,Node_List * worklist,Arena * old_arena,VectorSet * old_space,VectorSet * new_space)1666 bool Node::add_to_worklist(Node* n, Node_List* worklist, Arena* old_arena, VectorSet* old_space, VectorSet* new_space) {
1667 if (not_a_node(n)) {
1668 return false; // Gracefully handle NULL, -1, 0xabababab, etc.
1669 }
1670
1671 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1672 VectorSet* v = old_arena->contains(n) ? old_space : new_space;
1673 if (!v->test_set(n->_idx)) {
1674 worklist->push(n);
1675 return true;
1676 }
1677 return false;
1678 }
1679
1680 // -----------------------------Name-------------------------------------------
1681 extern const char *NodeClassNames[];
Name() const1682 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1683
is_disconnected(const Node * n)1684 static bool is_disconnected(const Node* n) {
1685 for (uint i = 0; i < n->req(); i++) {
1686 if (n->in(i) != NULL) return false;
1687 }
1688 return true;
1689 }
1690
1691 #ifdef ASSERT
dump_orig(outputStream * st,bool print_key) const1692 void Node::dump_orig(outputStream *st, bool print_key) const {
1693 Compile* C = Compile::current();
1694 Node* orig = _debug_orig;
1695 if (not_a_node(orig)) orig = NULL;
1696 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1697 if (orig == NULL) return;
1698 if (print_key) {
1699 st->print(" !orig=");
1700 }
1701 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1702 if (not_a_node(fast)) fast = NULL;
1703 while (orig != NULL) {
1704 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1705 if (discon) st->print("[");
1706 if (!Compile::current()->node_arena()->contains(orig))
1707 st->print("o");
1708 st->print("%d", orig->_idx);
1709 if (discon) st->print("]");
1710 orig = orig->debug_orig();
1711 if (not_a_node(orig)) orig = NULL;
1712 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1713 if (orig != NULL) st->print(",");
1714 if (fast != NULL) {
1715 // Step fast twice for each single step of orig:
1716 fast = fast->debug_orig();
1717 if (not_a_node(fast)) fast = NULL;
1718 if (fast != NULL && fast != orig) {
1719 fast = fast->debug_orig();
1720 if (not_a_node(fast)) fast = NULL;
1721 }
1722 if (fast == orig) {
1723 st->print("...");
1724 break;
1725 }
1726 }
1727 }
1728 }
1729
set_debug_orig(Node * orig)1730 void Node::set_debug_orig(Node* orig) {
1731 _debug_orig = orig;
1732 if (BreakAtNode == 0) return;
1733 if (not_a_node(orig)) orig = NULL;
1734 int trip = 10;
1735 while (orig != NULL) {
1736 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1737 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1738 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1739 BREAKPOINT;
1740 }
1741 orig = orig->debug_orig();
1742 if (not_a_node(orig)) orig = NULL;
1743 if (trip-- <= 0) break;
1744 }
1745 }
1746 #endif //ASSERT
1747
1748 //------------------------------dump------------------------------------------
1749 // Dump a Node
dump(const char * suffix,bool mark,outputStream * st) const1750 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1751 Compile* C = Compile::current();
1752 bool is_new = C->node_arena()->contains(this);
1753 C->_in_dump_cnt++;
1754
1755 if (_indent > 0) {
1756 st->print("%*s", (_indent << 1), " ");
1757 }
1758
1759 st->print("%c%d%s%s === ", is_new ? ' ' : 'o', _idx, mark ? " >" : " ", Name());
1760
1761 // Dump the required and precedence inputs
1762 dump_req(st);
1763 dump_prec(st);
1764 // Dump the outputs
1765 dump_out(st);
1766
1767 if (is_disconnected(this)) {
1768 #ifdef ASSERT
1769 st->print(" [%d]",debug_idx());
1770 dump_orig(st);
1771 #endif
1772 st->cr();
1773 C->_in_dump_cnt--;
1774 return; // don't process dead nodes
1775 }
1776
1777 if (C->clone_map().value(_idx) != 0) {
1778 C->clone_map().dump(_idx);
1779 }
1780 // Dump node-specific info
1781 dump_spec(st);
1782 #ifdef ASSERT
1783 // Dump the non-reset _debug_idx
1784 if (Verbose && WizardMode) {
1785 st->print(" [%d]",debug_idx());
1786 }
1787 #endif
1788
1789 const Type *t = bottom_type();
1790
1791 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1792 const TypeInstPtr *toop = t->isa_instptr();
1793 const TypeKlassPtr *tkls = t->isa_klassptr();
1794 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1795 if (klass && klass->is_loaded() && klass->is_interface()) {
1796 st->print(" Interface:");
1797 } else if (toop) {
1798 st->print(" Oop:");
1799 } else if (tkls) {
1800 st->print(" Klass:");
1801 }
1802 t->dump_on(st);
1803 } else if (t == Type::MEMORY) {
1804 st->print(" Memory:");
1805 MemNode::dump_adr_type(this, adr_type(), st);
1806 } else if (Verbose || WizardMode) {
1807 st->print(" Type:");
1808 if (t) {
1809 t->dump_on(st);
1810 } else {
1811 st->print("no type");
1812 }
1813 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1814 // Dump MachSpillcopy vector type.
1815 t->dump_on(st);
1816 }
1817 if (is_new) {
1818 DEBUG_ONLY(dump_orig(st));
1819 Node_Notes* nn = C->node_notes_at(_idx);
1820 if (nn != NULL && !nn->is_clear()) {
1821 if (nn->jvms() != NULL) {
1822 st->print(" !jvms:");
1823 nn->jvms()->dump_spec(st);
1824 }
1825 }
1826 }
1827 if (suffix) st->print("%s", suffix);
1828 C->_in_dump_cnt--;
1829 }
1830
1831 //------------------------------dump_req--------------------------------------
dump_req(outputStream * st) const1832 void Node::dump_req(outputStream *st) const {
1833 // Dump the required input edges
1834 for (uint i = 0; i < req(); i++) { // For all required inputs
1835 Node* d = in(i);
1836 if (d == NULL) {
1837 st->print("_ ");
1838 } else if (not_a_node(d)) {
1839 st->print("not_a_node "); // uninitialized, sentinel, garbage, etc.
1840 } else {
1841 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1842 }
1843 }
1844 }
1845
1846
1847 //------------------------------dump_prec-------------------------------------
dump_prec(outputStream * st) const1848 void Node::dump_prec(outputStream *st) const {
1849 // Dump the precedence edges
1850 int any_prec = 0;
1851 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1852 Node* p = in(i);
1853 if (p != NULL) {
1854 if (!any_prec++) st->print(" |");
1855 if (not_a_node(p)) { st->print("not_a_node "); continue; }
1856 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1857 }
1858 }
1859 }
1860
1861 //------------------------------dump_out--------------------------------------
dump_out(outputStream * st) const1862 void Node::dump_out(outputStream *st) const {
1863 // Delimit the output edges
1864 st->print(" [[");
1865 // Dump the output edges
1866 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1867 Node* u = _out[i];
1868 if (u == NULL) {
1869 st->print("_ ");
1870 } else if (not_a_node(u)) {
1871 st->print("not_a_node ");
1872 } else {
1873 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1874 }
1875 }
1876 st->print("]] ");
1877 }
1878
1879 //----------------------------collect_nodes_i----------------------------------
1880 // Collects nodes from an Ideal graph, starting from a given start node and
1881 // moving in a given direction until a certain depth (distance from the start
1882 // node) is reached. Duplicates are ignored.
1883 // Arguments:
1884 // queue: the nodes are collected into this array.
1885 // start: the node at which to start collecting.
1886 // direction: if this is a positive number, collect input nodes; if it is
1887 // a negative number, collect output nodes.
1888 // depth: collect nodes up to this distance from the start node.
1889 // include_start: whether to include the start node in the result collection.
1890 // only_ctrl: whether to regard control edges only during traversal.
1891 // only_data: whether to regard data edges only during traversal.
collect_nodes_i(GrowableArray<Node * > * queue,const Node * start,int direction,uint depth,bool include_start,bool only_ctrl,bool only_data)1892 static void collect_nodes_i(GrowableArray<Node*>* queue, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1893 bool indent = depth <= PrintIdealIndentThreshold;
1894 Node* s = (Node*) start; // remove const
1895 queue->append(s);
1896 int begin = 0;
1897 int end = 0;
1898
1899 s->set_indent(0);
1900 for(uint i = 0; i < depth; i++) {
1901 end = queue->length();
1902 for(int j = begin; j < end; j++) {
1903 Node* tp = queue->at(j);
1904 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1905 for(uint k = 0; k < limit; k++) {
1906 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1907
1908 if (not_a_node(n)) continue;
1909 // do not recurse through top or the root (would reach unrelated stuff)
1910 if (n->is_Root() || n->is_top()) continue;
1911 if (only_ctrl && !n->is_CFG()) continue;
1912 if (only_data && n->is_CFG()) continue;
1913 bool in_queue = queue->contains(n);
1914 if (!in_queue) {
1915 queue->append(n);
1916 n->set_indent(indent ? (i + 1) : 0);
1917 }
1918 }
1919 }
1920 begin = end;
1921 }
1922 if (!include_start) {
1923 queue->remove(s);
1924 }
1925 }
1926
1927 //------------------------------dump_nodes-------------------------------------
dump_nodes(const Node * start,int d,bool only_ctrl)1928 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1929 if (not_a_node(start)) return;
1930
1931 GrowableArray <Node *> queue(Compile::current()->live_nodes());
1932 collect_nodes_i(&queue, start, d, (uint) ABS(d), true, only_ctrl, false);
1933
1934 int end = queue.length();
1935 if (d > 0) {
1936 for(int j = end-1; j >= 0; j--) {
1937 queue.at(j)->dump();
1938 }
1939 } else {
1940 for(int j = 0; j < end; j++) {
1941 queue.at(j)->dump();
1942 }
1943 }
1944 }
1945
1946 //------------------------------dump-------------------------------------------
dump(int d) const1947 void Node::dump(int d) const {
1948 dump_nodes(this, d, false);
1949 }
1950
1951 //------------------------------dump_ctrl--------------------------------------
1952 // Dump a Node's control history to depth
dump_ctrl(int d) const1953 void Node::dump_ctrl(int d) const {
1954 dump_nodes(this, d, true);
1955 }
1956
1957 //-----------------------------dump_compact------------------------------------
dump_comp() const1958 void Node::dump_comp() const {
1959 this->dump_comp("\n");
1960 }
1961
1962 //-----------------------------dump_compact------------------------------------
1963 // Dump a Node in compact representation, i.e., just print its name and index.
1964 // Nodes can specify additional specifics to print in compact representation by
1965 // implementing dump_compact_spec.
dump_comp(const char * suffix,outputStream * st) const1966 void Node::dump_comp(const char* suffix, outputStream *st) const {
1967 Compile* C = Compile::current();
1968 C->_in_dump_cnt++;
1969 st->print("%s(%d)", Name(), _idx);
1970 this->dump_compact_spec(st);
1971 if (suffix) {
1972 st->print("%s", suffix);
1973 }
1974 C->_in_dump_cnt--;
1975 }
1976
1977 //----------------------------dump_related-------------------------------------
1978 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1979 // hand and is determined by the implementation of the virtual method rel.
dump_related() const1980 void Node::dump_related() const {
1981 Compile* C = Compile::current();
1982 GrowableArray <Node *> in_rel(C->unique());
1983 GrowableArray <Node *> out_rel(C->unique());
1984 this->related(&in_rel, &out_rel, false);
1985 for (int i = in_rel.length() - 1; i >= 0; i--) {
1986 in_rel.at(i)->dump();
1987 }
1988 this->dump("\n", true);
1989 for (int i = 0; i < out_rel.length(); i++) {
1990 out_rel.at(i)->dump();
1991 }
1992 }
1993
1994 //----------------------------dump_related-------------------------------------
1995 // Dump a Node's related nodes up to a given depth (distance from the start
1996 // node).
1997 // Arguments:
1998 // d_in: depth for input nodes.
1999 // d_out: depth for output nodes (note: this also is a positive number).
dump_related(uint d_in,uint d_out) const2000 void Node::dump_related(uint d_in, uint d_out) const {
2001 Compile* C = Compile::current();
2002 GrowableArray <Node *> in_rel(C->unique());
2003 GrowableArray <Node *> out_rel(C->unique());
2004
2005 // call collect_nodes_i directly
2006 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
2007 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
2008
2009 for (int i = in_rel.length() - 1; i >= 0; i--) {
2010 in_rel.at(i)->dump();
2011 }
2012 this->dump("\n", true);
2013 for (int i = 0; i < out_rel.length(); i++) {
2014 out_rel.at(i)->dump();
2015 }
2016 }
2017
2018 //------------------------dump_related_compact---------------------------------
2019 // Dump a Node's related nodes in compact representation. The notion of
2020 // "related" depends on the Node at hand and is determined by the implementation
2021 // of the virtual method rel.
dump_related_compact() const2022 void Node::dump_related_compact() const {
2023 Compile* C = Compile::current();
2024 GrowableArray <Node *> in_rel(C->unique());
2025 GrowableArray <Node *> out_rel(C->unique());
2026 this->related(&in_rel, &out_rel, true);
2027 int n_in = in_rel.length();
2028 int n_out = out_rel.length();
2029
2030 this->dump_comp(n_in == 0 ? "\n" : " ");
2031 for (int i = 0; i < n_in; i++) {
2032 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
2033 }
2034 for (int i = 0; i < n_out; i++) {
2035 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
2036 }
2037 }
2038
2039 //------------------------------related----------------------------------------
2040 // Collect a Node's related nodes. The default behaviour just collects the
2041 // inputs and outputs at depth 1, including both control and data flow edges,
2042 // regardless of whether the presentation is compact or not. For data nodes,
2043 // the default is to collect all data inputs (till level 1 if compact), and
2044 // outputs till level 1.
related(GrowableArray<Node * > * in_rel,GrowableArray<Node * > * out_rel,bool compact) const2045 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
2046 if (this->is_CFG()) {
2047 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
2048 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
2049 } else {
2050 if (compact) {
2051 this->collect_nodes(in_rel, 1, false, true);
2052 } else {
2053 this->collect_nodes_in_all_data(in_rel, false);
2054 }
2055 this->collect_nodes(out_rel, -1, false, false);
2056 }
2057 }
2058
2059 //---------------------------collect_nodes-------------------------------------
2060 // An entry point to the low-level node collection facility, to start from a
2061 // given node in the graph. The start node is by default not included in the
2062 // result.
2063 // Arguments:
2064 // ns: collect the nodes into this data structure.
2065 // d: the depth (distance from start node) to which nodes should be
2066 // collected. A value >0 indicates input nodes, a value <0, output
2067 // nodes.
2068 // ctrl: include only control nodes.
2069 // data: include only data nodes.
collect_nodes(GrowableArray<Node * > * ns,int d,bool ctrl,bool data) const2070 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
2071 if (ctrl && data) {
2072 // ignore nonsensical combination
2073 return;
2074 }
2075 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
2076 }
2077
2078 //--------------------------collect_nodes_in-----------------------------------
collect_nodes_in(Node * start,GrowableArray<Node * > * ns,bool primary_is_data,bool collect_secondary)2079 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
2080 // The maximum depth is determined using a BFS that visits all primary (data
2081 // or control) inputs and increments the depth at each level.
2082 uint d_in = 0;
2083 GrowableArray<Node*> nodes(Compile::current()->unique());
2084 nodes.push(start);
2085 int nodes_at_current_level = 1;
2086 int n_idx = 0;
2087 while (nodes_at_current_level > 0) {
2088 // Add all primary inputs reachable from the current level to the list, and
2089 // increase the depth if there were any.
2090 int nodes_at_next_level = 0;
2091 bool nodes_added = false;
2092 while (nodes_at_current_level > 0) {
2093 nodes_at_current_level--;
2094 Node* current = nodes.at(n_idx++);
2095 for (uint i = 0; i < current->len(); i++) {
2096 Node* n = current->in(i);
2097 if (not_a_node(n)) {
2098 continue;
2099 }
2100 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
2101 continue;
2102 }
2103 if (!nodes.contains(n)) {
2104 nodes.push(n);
2105 nodes_added = true;
2106 nodes_at_next_level++;
2107 }
2108 }
2109 }
2110 if (nodes_added) {
2111 d_in++;
2112 }
2113 nodes_at_current_level = nodes_at_next_level;
2114 }
2115 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
2116 if (collect_secondary) {
2117 // Now, iterate over the secondary nodes in ns and add the respective
2118 // boundary reachable from them.
2119 GrowableArray<Node*> sns(Compile::current()->unique());
2120 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2121 Node* n = *it;
2122 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2123 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2124 ns->append_if_missing(*d);
2125 }
2126 sns.clear();
2127 }
2128 }
2129 }
2130
2131 //---------------------collect_nodes_in_all_data-------------------------------
2132 // Collect the entire data input graph. Include the control boundary if
2133 // requested.
2134 // Arguments:
2135 // ns: collect the nodes into this data structure.
2136 // ctrl: if true, include the control boundary.
collect_nodes_in_all_data(GrowableArray<Node * > * ns,bool ctrl) const2137 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2138 collect_nodes_in((Node*) this, ns, true, ctrl);
2139 }
2140
2141 //--------------------------collect_nodes_in_all_ctrl--------------------------
2142 // Collect the entire control input graph. Include the data boundary if
2143 // requested.
2144 // ns: collect the nodes into this data structure.
2145 // data: if true, include the control boundary.
collect_nodes_in_all_ctrl(GrowableArray<Node * > * ns,bool data) const2146 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2147 collect_nodes_in((Node*) this, ns, false, data);
2148 }
2149
2150 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2151 // Collect the entire output graph until hitting control node boundaries, and
2152 // include those.
collect_nodes_out_all_ctrl_boundary(GrowableArray<Node * > * ns) const2153 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2154 // Perform a BFS and stop at control nodes.
2155 GrowableArray<Node*> nodes(Compile::current()->unique());
2156 nodes.push((Node*) this);
2157 while (nodes.length() > 0) {
2158 Node* current = nodes.pop();
2159 if (not_a_node(current)) {
2160 continue;
2161 }
2162 ns->append_if_missing(current);
2163 if (!current->is_CFG()) {
2164 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2165 nodes.push(current->out(i));
2166 }
2167 }
2168 }
2169 ns->remove((Node*) this);
2170 }
2171
2172 // VERIFICATION CODE
2173 // For each input edge to a node (ie - for each Use-Def edge), verify that
2174 // there is a corresponding Def-Use edge.
2175 //------------------------------verify_edges-----------------------------------
verify_edges(Unique_Node_List & visited)2176 void Node::verify_edges(Unique_Node_List &visited) {
2177 uint i, j, idx;
2178 int cnt;
2179 Node *n;
2180
2181 // Recursive termination test
2182 if (visited.member(this)) return;
2183 visited.push(this);
2184
2185 // Walk over all input edges, checking for correspondence
2186 for( i = 0; i < len(); i++ ) {
2187 n = in(i);
2188 if (n != NULL && !n->is_top()) {
2189 // Count instances of (Node *)this
2190 cnt = 0;
2191 for (idx = 0; idx < n->_outcnt; idx++ ) {
2192 if (n->_out[idx] == (Node *)this) cnt++;
2193 }
2194 assert( cnt > 0,"Failed to find Def-Use edge." );
2195 // Check for duplicate edges
2196 // walk the input array downcounting the input edges to n
2197 for( j = 0; j < len(); j++ ) {
2198 if( in(j) == n ) cnt--;
2199 }
2200 assert( cnt == 0,"Mismatched edge count.");
2201 } else if (n == NULL) {
2202 assert(i >= req() || i == 0 || is_Region() || is_Phi() || is_ArrayCopy() || (is_Unlock() && i == req()-1)
2203 || (is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
2204 "only region, phi, arraycopy, unlock or membar nodes have null data edges");
2205 } else {
2206 assert(n->is_top(), "sanity");
2207 // Nothing to check.
2208 }
2209 }
2210 // Recursive walk over all input edges
2211 for( i = 0; i < len(); i++ ) {
2212 n = in(i);
2213 if( n != NULL )
2214 in(i)->verify_edges(visited);
2215 }
2216 }
2217
2218 // Verify all nodes if verify_depth is negative
verify(int verify_depth,VectorSet & visited,Node_List & worklist)2219 void Node::verify(int verify_depth, VectorSet& visited, Node_List& worklist) {
2220 assert(verify_depth != 0, "depth should not be 0");
2221 Compile* C = Compile::current();
2222 uint last_index_on_current_depth = worklist.size() - 1;
2223 verify_depth--; // Visiting the first node on depth 1
2224 // Only add nodes to worklist if verify_depth is negative (visit all nodes) or greater than 0
2225 bool add_to_worklist = verify_depth != 0;
2226
2227 for (uint list_index = 0; list_index < worklist.size(); list_index++) {
2228 Node* n = worklist[list_index];
2229
2230 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2231 if (C->cached_top_node() == NULL) {
2232 C->set_cached_top_node((Node*)n);
2233 }
2234 assert(C->cached_top_node() == n, "TOP node must be unique");
2235 }
2236
2237 uint in_len = n->len();
2238 for (uint i = 0; i < in_len; i++) {
2239 Node* x = n->_in[i];
2240 if (!x || x->is_top()) {
2241 continue;
2242 }
2243
2244 // Verify my input has a def-use edge to me
2245 // Count use-def edges from n to x
2246 int cnt = 1;
2247 for (uint j = 0; j < i; j++) {
2248 if (n->_in[j] == x) {
2249 cnt++;
2250 break;
2251 }
2252 }
2253 if (cnt == 2) {
2254 // x is already checked as n's previous input, skip its duplicated def-use count checking
2255 continue;
2256 }
2257 for (uint j = i + 1; j < in_len; j++) {
2258 if (n->_in[j] == x) {
2259 cnt++;
2260 }
2261 }
2262
2263 // Count def-use edges from x to n
2264 uint max = x->_outcnt;
2265 for (uint k = 0; k < max; k++) {
2266 if (x->_out[k] == n) {
2267 cnt--;
2268 }
2269 }
2270 assert(cnt == 0, "mismatched def-use edge counts");
2271
2272 if (add_to_worklist && !visited.test_set(x->_idx)) {
2273 worklist.push(x);
2274 }
2275 }
2276
2277 if (verify_depth > 0 && list_index == last_index_on_current_depth) {
2278 // All nodes on this depth were processed and its inputs are on the worklist. Decrement verify_depth and
2279 // store the current last list index which is the last node in the list with the new depth. All nodes
2280 // added afterwards will have a new depth again. Stop adding new nodes if depth limit is reached (=0).
2281 verify_depth--;
2282 if (verify_depth == 0) {
2283 add_to_worklist = false;
2284 }
2285 last_index_on_current_depth = worklist.size() - 1;
2286 }
2287 }
2288 }
2289 #endif // not PRODUCT
2290
2291 //------------------------------Registers--------------------------------------
2292 // Do we Match on this edge index or not? Generally false for Control
2293 // and true for everything else. Weird for calls & returns.
match_edge(uint idx) const2294 uint Node::match_edge(uint idx) const {
2295 return idx; // True for other than index 0 (control)
2296 }
2297
2298 // Register classes are defined for specific machines
out_RegMask() const2299 const RegMask &Node::out_RegMask() const {
2300 ShouldNotCallThis();
2301 return RegMask::Empty;
2302 }
2303
in_RegMask(uint) const2304 const RegMask &Node::in_RegMask(uint) const {
2305 ShouldNotCallThis();
2306 return RegMask::Empty;
2307 }
2308
grow(uint i)2309 void Node_Array::grow(uint i) {
2310 assert(_max > 0, "invariant");
2311 uint old = _max;
2312 _max = next_power_of_2(i);
2313 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2314 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2315 }
2316
insert(uint i,Node * n)2317 void Node_Array::insert(uint i, Node* n) {
2318 if (_nodes[_max - 1]) {
2319 grow(_max);
2320 }
2321 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i + 1], ((_max - i - 1) * sizeof(Node*)));
2322 _nodes[i] = n;
2323 }
2324
remove(uint i)2325 void Node_Array::remove(uint i) {
2326 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i + 1], (HeapWord*)&_nodes[i], ((_max - i - 1) * sizeof(Node*)));
2327 _nodes[_max - 1] = NULL;
2328 }
2329
dump() const2330 void Node_Array::dump() const {
2331 #ifndef PRODUCT
2332 for (uint i = 0; i < _max; i++) {
2333 Node* nn = _nodes[i];
2334 if (nn != NULL) {
2335 tty->print("%5d--> ",i); nn->dump();
2336 }
2337 }
2338 #endif
2339 }
2340
2341 //--------------------------is_iteratively_computed------------------------------
2342 // Operation appears to be iteratively computed (such as an induction variable)
2343 // It is possible for this operation to return false for a loop-varying
2344 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
is_iteratively_computed()2345 bool Node::is_iteratively_computed() {
2346 if (ideal_reg()) { // does operation have a result register?
2347 for (uint i = 1; i < req(); i++) {
2348 Node* n = in(i);
2349 if (n != NULL && n->is_Phi()) {
2350 for (uint j = 1; j < n->req(); j++) {
2351 if (n->in(j) == this) {
2352 return true;
2353 }
2354 }
2355 }
2356 }
2357 }
2358 return false;
2359 }
2360
2361 //--------------------------find_similar------------------------------
2362 // Return a node with opcode "opc" and same inputs as "this" if one can
2363 // be found; Otherwise return NULL;
find_similar(int opc)2364 Node* Node::find_similar(int opc) {
2365 if (req() >= 2) {
2366 Node* def = in(1);
2367 if (def && def->outcnt() >= 2) {
2368 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2369 Node* use = def->fast_out(i);
2370 if (use != this &&
2371 use->Opcode() == opc &&
2372 use->req() == req()) {
2373 uint j;
2374 for (j = 0; j < use->req(); j++) {
2375 if (use->in(j) != in(j)) {
2376 break;
2377 }
2378 }
2379 if (j == use->req()) {
2380 return use;
2381 }
2382 }
2383 }
2384 }
2385 }
2386 return NULL;
2387 }
2388
2389
2390 //--------------------------unique_ctrl_out------------------------------
2391 // Return the unique control out if only one. Null if none or more than one.
unique_ctrl_out() const2392 Node* Node::unique_ctrl_out() const {
2393 Node* found = NULL;
2394 for (uint i = 0; i < outcnt(); i++) {
2395 Node* use = raw_out(i);
2396 if (use->is_CFG() && use != this) {
2397 if (found != NULL) {
2398 return NULL;
2399 }
2400 found = use;
2401 }
2402 }
2403 return found;
2404 }
2405
ensure_control_or_add_prec(Node * c)2406 void Node::ensure_control_or_add_prec(Node* c) {
2407 if (in(0) == NULL) {
2408 set_req(0, c);
2409 } else if (in(0) != c) {
2410 add_prec(c);
2411 }
2412 }
2413
is_dead_loop_safe() const2414 bool Node::is_dead_loop_safe() const {
2415 if (is_Phi()) {
2416 return true;
2417 }
2418 if (is_Proj() && in(0) == NULL) {
2419 return true;
2420 }
2421 if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
2422 if (!is_Proj()) {
2423 return true;
2424 }
2425 if (in(0)->is_Allocate()) {
2426 return false;
2427 }
2428 // MemNode::can_see_stored_value() peeks through the boxing call
2429 if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
2430 return false;
2431 }
2432 return true;
2433 }
2434 return false;
2435 }
2436
2437 //=============================================================================
2438 //------------------------------yank-------------------------------------------
2439 // Find and remove
yank(Node * n)2440 void Node_List::yank( Node *n ) {
2441 uint i;
2442 for (i = 0; i < _cnt; i++) {
2443 if (_nodes[i] == n) {
2444 break;
2445 }
2446 }
2447
2448 if (i < _cnt) {
2449 _nodes[i] = _nodes[--_cnt];
2450 }
2451 }
2452
2453 //------------------------------dump-------------------------------------------
dump() const2454 void Node_List::dump() const {
2455 #ifndef PRODUCT
2456 for (uint i = 0; i < _cnt; i++) {
2457 if (_nodes[i]) {
2458 tty->print("%5d--> ", i);
2459 _nodes[i]->dump();
2460 }
2461 }
2462 #endif
2463 }
2464
dump_simple() const2465 void Node_List::dump_simple() const {
2466 #ifndef PRODUCT
2467 for (uint i = 0; i < _cnt; i++) {
2468 if( _nodes[i] ) {
2469 tty->print(" %d", _nodes[i]->_idx);
2470 } else {
2471 tty->print(" NULL");
2472 }
2473 }
2474 #endif
2475 }
2476
2477 //=============================================================================
2478 //------------------------------remove-----------------------------------------
remove(Node * n)2479 void Unique_Node_List::remove(Node* n) {
2480 if (_in_worklist.test(n->_idx)) {
2481 for (uint i = 0; i < size(); i++) {
2482 if (_nodes[i] == n) {
2483 map(i, Node_List::pop());
2484 _in_worklist.remove(n->_idx);
2485 return;
2486 }
2487 }
2488 ShouldNotReachHere();
2489 }
2490 }
2491
2492 //-----------------------remove_useless_nodes----------------------------------
2493 // Remove useless nodes from worklist
remove_useless_nodes(VectorSet & useful)2494 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2495 for (uint i = 0; i < size(); ++i) {
2496 Node *n = at(i);
2497 assert( n != NULL, "Did not expect null entries in worklist");
2498 if (!useful.test(n->_idx)) {
2499 _in_worklist.remove(n->_idx);
2500 map(i, Node_List::pop());
2501 --i; // Visit popped node
2502 // If it was last entry, loop terminates since size() was also reduced
2503 }
2504 }
2505 }
2506
2507 //=============================================================================
grow()2508 void Node_Stack::grow() {
2509 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2510 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2511 size_t max = old_max << 1; // max * 2
2512 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2513 _inode_max = _inodes + max;
2514 _inode_top = _inodes + old_top; // restore _top
2515 }
2516
2517 // Node_Stack is used to map nodes.
find(uint idx) const2518 Node* Node_Stack::find(uint idx) const {
2519 uint sz = size();
2520 for (uint i = 0; i < sz; i++) {
2521 if (idx == index_at(i)) {
2522 return node_at(i);
2523 }
2524 }
2525 return NULL;
2526 }
2527
2528 //=============================================================================
size_of() const2529 uint TypeNode::size_of() const { return sizeof(*this); }
2530 #ifndef PRODUCT
dump_spec(outputStream * st) const2531 void TypeNode::dump_spec(outputStream *st) const {
2532 if (!Verbose && !WizardMode) {
2533 // standard dump does this in Verbose and WizardMode
2534 st->print(" #"); _type->dump_on(st);
2535 }
2536 }
2537
dump_compact_spec(outputStream * st) const2538 void TypeNode::dump_compact_spec(outputStream *st) const {
2539 st->print("#");
2540 _type->dump_on(st);
2541 }
2542 #endif
hash() const2543 uint TypeNode::hash() const {
2544 return Node::hash() + _type->hash();
2545 }
cmp(const Node & n) const2546 bool TypeNode::cmp(const Node& n) const {
2547 return !Type::cmp(_type, ((TypeNode&)n)._type);
2548 }
bottom_type() const2549 const Type* TypeNode::bottom_type() const { return _type; }
Value(PhaseGVN * phase) const2550 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
2551
2552 //------------------------------ideal_reg--------------------------------------
ideal_reg() const2553 uint TypeNode::ideal_reg() const {
2554 return _type->ideal_reg();
2555 }
2556