1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "libadt/vectset.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "opto/cfgnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/loopnode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/node.hpp"
34 #include "opto/opcodes.hpp"
35 #include "opto/regmask.hpp"
36 #include "opto/type.hpp"
37 #include "utilities/copy.hpp"
38
39 class RegMask;
40 // #include "phase.hpp"
41 class PhaseTransform;
42 class PhaseGVN;
43
44 // Arena we are currently building Nodes in
45 const uint Node::NotAMachineReg = 0xffff0000;
46
47 #ifndef PRODUCT
48 extern int nodes_created;
49 #endif
50
51 #ifdef ASSERT
52
53 //-------------------------- construct_node------------------------------------
54 // Set a breakpoint here to identify where a particular node index is built.
55 void Node::verify_construction() {
56 _debug_orig = NULL;
57 int old_debug_idx = Compile::debug_idx();
58 int new_debug_idx = old_debug_idx+1;
59 if (new_debug_idx > 0) {
60 // Arrange that the lowest five decimal digits of _debug_idx
61 // will repeat those of _idx. In case this is somehow pathological,
62 // we continue to assign negative numbers (!) consecutively.
63 const int mod = 100000;
64 int bump = (int)(_idx - new_debug_idx) % mod;
65 if (bump < 0) bump += mod;
66 assert(bump >= 0 && bump < mod, "");
67 new_debug_idx += bump;
68 }
69 Compile::set_debug_idx(new_debug_idx);
70 set_debug_idx( new_debug_idx );
71 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
72 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
73 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
74 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
75 BREAKPOINT;
76 }
77 #if OPTO_DU_ITERATOR_ASSERT
78 _last_del = NULL;
79 _del_tick = 0;
80 #endif
81 _hash_lock = 0;
82 }
83
84
85 // #ifdef ASSERT ...
86
87 #if OPTO_DU_ITERATOR_ASSERT
88 void DUIterator_Common::sample(const Node* node) {
89 _vdui = VerifyDUIterators;
90 _node = node;
91 _outcnt = node->_outcnt;
92 _del_tick = node->_del_tick;
93 _last = NULL;
94 }
95
96 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
97 assert(_node == node, "consistent iterator source");
98 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
99 }
100
101 void DUIterator_Common::verify_resync() {
102 // Ensure that the loop body has just deleted the last guy produced.
103 const Node* node = _node;
104 // Ensure that at least one copy of the last-seen edge was deleted.
105 // Note: It is OK to delete multiple copies of the last-seen edge.
106 // Unfortunately, we have no way to verify that all the deletions delete
107 // that same edge. On this point we must use the Honor System.
108 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
109 assert(node->_last_del == _last, "must have deleted the edge just produced");
110 // We liked this deletion, so accept the resulting outcnt and tick.
111 _outcnt = node->_outcnt;
112 _del_tick = node->_del_tick;
113 }
114
115 void DUIterator_Common::reset(const DUIterator_Common& that) {
116 if (this == &that) return; // ignore assignment to self
117 if (!_vdui) {
118 // We need to initialize everything, overwriting garbage values.
119 _last = that._last;
120 _vdui = that._vdui;
121 }
122 // Note: It is legal (though odd) for an iterator over some node x
123 // to be reassigned to iterate over another node y. Some doubly-nested
124 // progress loops depend on being able to do this.
125 const Node* node = that._node;
126 // Re-initialize everything, except _last.
127 _node = node;
128 _outcnt = node->_outcnt;
129 _del_tick = node->_del_tick;
130 }
131
132 void DUIterator::sample(const Node* node) {
133 DUIterator_Common::sample(node); // Initialize the assertion data.
134 _refresh_tick = 0; // No refreshes have happened, as yet.
135 }
136
137 void DUIterator::verify(const Node* node, bool at_end_ok) {
138 DUIterator_Common::verify(node, at_end_ok);
139 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
140 }
141
142 void DUIterator::verify_increment() {
143 if (_refresh_tick & 1) {
144 // We have refreshed the index during this loop.
145 // Fix up _idx to meet asserts.
146 if (_idx > _outcnt) _idx = _outcnt;
147 }
148 verify(_node, true);
149 }
150
151 void DUIterator::verify_resync() {
152 // Note: We do not assert on _outcnt, because insertions are OK here.
153 DUIterator_Common::verify_resync();
154 // Make sure we are still in sync, possibly with no more out-edges:
155 verify(_node, true);
156 }
157
158 void DUIterator::reset(const DUIterator& that) {
159 if (this == &that) return; // self assignment is always a no-op
160 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
161 assert(that._idx == 0, "assign only the result of Node::outs()");
162 assert(_idx == that._idx, "already assigned _idx");
163 if (!_vdui) {
164 // We need to initialize everything, overwriting garbage values.
165 sample(that._node);
166 } else {
167 DUIterator_Common::reset(that);
168 if (_refresh_tick & 1) {
169 _refresh_tick++; // Clear the "was refreshed" flag.
170 }
171 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
172 }
173 }
174
175 void DUIterator::refresh() {
176 DUIterator_Common::sample(_node); // Re-fetch assertion data.
177 _refresh_tick |= 1; // Set the "was refreshed" flag.
178 }
179
180 void DUIterator::verify_finish() {
181 // If the loop has killed the node, do not require it to re-run.
182 if (_node->_outcnt == 0) _refresh_tick &= ~1;
183 // If this assert triggers, it means that a loop used refresh_out_pos
184 // to re-synch an iteration index, but the loop did not correctly
185 // re-run itself, using a "while (progress)" construct.
186 // This iterator enforces the rule that you must keep trying the loop
187 // until it "runs clean" without any need for refreshing.
188 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
189 }
190
191
192 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
193 DUIterator_Common::verify(node, at_end_ok);
194 Node** out = node->_out;
195 uint cnt = node->_outcnt;
196 assert(cnt == _outcnt, "no insertions allowed");
197 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
198 // This last check is carefully designed to work for NO_OUT_ARRAY.
199 }
200
201 void DUIterator_Fast::verify_limit() {
202 const Node* node = _node;
203 verify(node, true);
204 assert(_outp == node->_out + node->_outcnt, "limit still correct");
205 }
206
207 void DUIterator_Fast::verify_resync() {
208 const Node* node = _node;
209 if (_outp == node->_out + _outcnt) {
210 // Note that the limit imax, not the pointer i, gets updated with the
211 // exact count of deletions. (For the pointer it's always "--i".)
212 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
213 // This is a limit pointer, with a name like "imax".
214 // Fudge the _last field so that the common assert will be happy.
215 _last = (Node*) node->_last_del;
216 DUIterator_Common::verify_resync();
217 } else {
218 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
219 // A normal internal pointer.
220 DUIterator_Common::verify_resync();
221 // Make sure we are still in sync, possibly with no more out-edges:
222 verify(node, true);
223 }
224 }
225
226 void DUIterator_Fast::verify_relimit(uint n) {
227 const Node* node = _node;
228 assert((int)n > 0, "use imax -= n only with a positive count");
229 // This must be a limit pointer, with a name like "imax".
230 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
231 // The reported number of deletions must match what the node saw.
232 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
233 // Fudge the _last field so that the common assert will be happy.
234 _last = (Node*) node->_last_del;
235 DUIterator_Common::verify_resync();
236 }
237
238 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
239 assert(_outp == that._outp, "already assigned _outp");
240 DUIterator_Common::reset(that);
241 }
242
243 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
244 // at_end_ok means the _outp is allowed to underflow by 1
245 _outp += at_end_ok;
246 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
247 _outp -= at_end_ok;
248 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
249 }
250
251 void DUIterator_Last::verify_limit() {
252 // Do not require the limit address to be resynched.
253 //verify(node, true);
254 assert(_outp == _node->_out, "limit still correct");
255 }
256
257 void DUIterator_Last::verify_step(uint num_edges) {
258 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
259 _outcnt -= num_edges;
260 _del_tick += num_edges;
261 // Make sure we are still in sync, possibly with no more out-edges:
262 const Node* node = _node;
263 verify(node, true);
264 assert(node->_last_del == _last, "must have deleted the edge just produced");
265 }
266
267 #endif //OPTO_DU_ITERATOR_ASSERT
268
269
270 #endif //ASSERT
271
272
273 // This constant used to initialize _out may be any non-null value.
274 // The value NULL is reserved for the top node only.
275 #define NO_OUT_ARRAY ((Node**)-1)
276
277 // This funny expression handshakes with Node::operator new
278 // to pull Compile::current out of the new node's _out field,
279 // and then calls a subroutine which manages most field
280 // initializations. The only one which is tricky is the
281 // _idx field, which is const, and so must be initialized
282 // by a return value, not an assignment.
283 //
284 // (Aren't you thankful that Java finals don't require so many tricks?)
285 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
286 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
287 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
288 #endif
289 #ifdef __clang__
290 #pragma clang diagnostic push
291 #pragma GCC diagnostic ignored "-Wuninitialized"
292 #endif
293
294 // Out-of-line code from node constructors.
295 // Executed only when extra debug info. is being passed around.
296 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
297 C->set_node_notes_at(idx, nn);
298 }
299
300 // Shared initialization code.
301 inline int Node::Init(int req, Compile* C) {
302 assert(Compile::current() == C, "must use operator new(Compile*)");
303 int idx = C->next_unique();
304
305 // Allocate memory for the necessary number of edges.
306 if (req > 0) {
307 // Allocate space for _in array to have double alignment.
308 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
309 #ifdef ASSERT
310 _in[req-1] = this; // magic cookie for assertion check
311 #endif
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.
330 Node::Node(uint req)
331 : _idx(IDX_INIT(req))
332 #ifdef ASSERT
333 , _parse_idx(_idx)
334 #endif
335 {
336 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
337 debug_only( verify_construction() );
338 NOT_PRODUCT(nodes_created++);
339 if (req == 0) {
340 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
341 _in = NULL;
342 } else {
343 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
344 Node** to = _in;
345 for(uint i = 0; i < req; i++) {
346 to[i] = NULL;
347 }
348 }
349 }
350
351 //------------------------------Node-------------------------------------------
352 Node::Node(Node *n0)
353 : _idx(IDX_INIT(1))
354 #ifdef ASSERT
355 , _parse_idx(_idx)
356 #endif
357 {
358 debug_only( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 // Assert we allocated space for input array already
361 assert( _in[0] == this, "Must pass arg count to 'new'" );
362 assert( is_not_dead(n0), "can not use dead node");
363 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
364 }
365
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1)
368 : _idx(IDX_INIT(2))
369 #ifdef ASSERT
370 , _parse_idx(_idx)
371 #endif
372 {
373 debug_only( verify_construction() );
374 NOT_PRODUCT(nodes_created++);
375 // Assert we allocated space for input array already
376 assert( _in[1] == this, "Must pass arg count to 'new'" );
377 assert( is_not_dead(n0), "can not use dead node");
378 assert( is_not_dead(n1), "can not use dead node");
379 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
380 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
381 }
382
383 //------------------------------Node-------------------------------------------
384 Node::Node(Node *n0, Node *n1, Node *n2)
385 : _idx(IDX_INIT(3))
386 #ifdef ASSERT
387 , _parse_idx(_idx)
388 #endif
389 {
390 debug_only( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
392 // Assert we allocated space for input array already
393 assert( _in[2] == this, "Must pass arg count to 'new'" );
394 assert( is_not_dead(n0), "can not use dead node");
395 assert( is_not_dead(n1), "can not use dead node");
396 assert( is_not_dead(n2), "can not use dead node");
397 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
398 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
399 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
400 }
401
402 //------------------------------Node-------------------------------------------
403 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
404 : _idx(IDX_INIT(4))
405 #ifdef ASSERT
406 , _parse_idx(_idx)
407 #endif
408 {
409 debug_only( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 // Assert we allocated space for input array already
412 assert( _in[3] == this, "Must pass arg count to 'new'" );
413 assert( is_not_dead(n0), "can not use dead node");
414 assert( is_not_dead(n1), "can not use dead node");
415 assert( is_not_dead(n2), "can not use dead node");
416 assert( is_not_dead(n3), "can not use dead node");
417 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
418 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
419 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
420 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
421 }
422
423 //------------------------------Node-------------------------------------------
424 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
425 : _idx(IDX_INIT(5))
426 #ifdef ASSERT
427 , _parse_idx(_idx)
428 #endif
429 {
430 debug_only( verify_construction() );
431 NOT_PRODUCT(nodes_created++);
432 // Assert we allocated space for input array already
433 assert( _in[4] == this, "Must pass arg count to 'new'" );
434 assert( is_not_dead(n0), "can not use dead node");
435 assert( is_not_dead(n1), "can not use dead node");
436 assert( is_not_dead(n2), "can not use dead node");
437 assert( is_not_dead(n3), "can not use dead node");
438 assert( is_not_dead(n4), "can not use dead node");
439 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
444 }
445
446 //------------------------------Node-------------------------------------------
447 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
448 Node *n4, Node *n5)
449 : _idx(IDX_INIT(6))
450 #ifdef ASSERT
451 , _parse_idx(_idx)
452 #endif
453 {
454 debug_only( verify_construction() );
455 NOT_PRODUCT(nodes_created++);
456 // Assert we allocated space for input array already
457 assert( _in[5] == this, "Must pass arg count to 'new'" );
458 assert( is_not_dead(n0), "can not use dead node");
459 assert( is_not_dead(n1), "can not use dead node");
460 assert( is_not_dead(n2), "can not use dead node");
461 assert( is_not_dead(n3), "can not use dead node");
462 assert( is_not_dead(n4), "can not use dead node");
463 assert( is_not_dead(n5), "can not use dead node");
464 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
465 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
466 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
467 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
468 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
469 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
470 }
471
472 //------------------------------Node-------------------------------------------
473 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
474 Node *n4, Node *n5, Node *n6)
475 : _idx(IDX_INIT(7))
476 #ifdef ASSERT
477 , _parse_idx(_idx)
478 #endif
479 {
480 debug_only( verify_construction() );
481 NOT_PRODUCT(nodes_created++);
482 // Assert we allocated space for input array already
483 assert( _in[6] == this, "Must pass arg count to 'new'" );
484 assert( is_not_dead(n0), "can not use dead node");
485 assert( is_not_dead(n1), "can not use dead node");
486 assert( is_not_dead(n2), "can not use dead node");
487 assert( is_not_dead(n3), "can not use dead node");
488 assert( is_not_dead(n4), "can not use dead node");
489 assert( is_not_dead(n5), "can not use dead node");
490 assert( is_not_dead(n6), "can not use dead node");
491 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
492 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
493 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
494 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
495 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
496 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
497 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
498 }
499
500 #ifdef __clang__
501 #pragma clang diagnostic pop
502 #endif
503
504
505 //------------------------------clone------------------------------------------
506 // Clone a Node.
507 Node *Node::clone() const {
508 Compile* C = Compile::current();
509 uint s = size_of(); // Size of inherited Node
510 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
511 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
512 // Set the new input pointer array
513 n->_in = (Node**)(((char*)n)+s);
514 // Cannot share the old output pointer array, so kill it
515 n->_out = NO_OUT_ARRAY;
516 // And reset the counters to 0
517 n->_outcnt = 0;
518 n->_outmax = 0;
519 // Unlock this guy, since he is not in any hash table.
520 debug_only(n->_hash_lock = 0);
521 // Walk the old node's input list to duplicate its edges
522 uint i;
523 for( i = 0; i < len(); i++ ) {
524 Node *x = in(i);
525 n->_in[i] = x;
526 if (x != NULL) x->add_out(n);
527 }
528 if (is_macro())
529 C->add_macro_node(n);
530 if (is_expensive())
531 C->add_expensive_node(n);
532 // If the cloned node is a range check dependent CastII, add it to the list.
533 CastIINode* cast = n->isa_CastII();
534 if (cast != NULL && cast->has_range_check()) {
535 C->add_range_check_cast(cast);
536 }
537
538 n->set_idx(C->next_unique()); // Get new unique index as well
539 debug_only( n->verify_construction() );
540 NOT_PRODUCT(nodes_created++);
541 // Do not patch over the debug_idx of a clone, because it makes it
542 // impossible to break on the clone's moment of creation.
543 //debug_only( n->set_debug_idx( debug_idx() ) );
544
545 C->copy_node_notes_to(n, (Node*) this);
546
547 // MachNode clone
548 uint nopnds;
549 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
550 MachNode *mach = n->as_Mach();
551 MachNode *mthis = this->as_Mach();
552 // Get address of _opnd_array.
553 // It should be the same offset since it is the clone of this node.
554 MachOper **from = mthis->_opnds;
555 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
556 pointer_delta((const void*)from,
557 (const void*)(&mthis->_opnds), 1));
558 mach->_opnds = to;
559 for ( uint i = 0; i < nopnds; ++i ) {
560 to[i] = from[i]->clone(C);
561 }
562 }
563 // cloning CallNode may need to clone JVMState
564 if (n->is_Call()) {
565 n->as_Call()->clone_jvms(C);
566 }
567 if (n->is_SafePoint()) {
568 n->as_SafePoint()->clone_replaced_nodes();
569 }
570 return n; // Return the clone
571 }
572
573 //---------------------------setup_is_top--------------------------------------
574 // Call this when changing the top node, to reassert the invariants
575 // required by Node::is_top. See Compile::set_cached_top_node.
576 void Node::setup_is_top() {
577 if (this == (Node*)Compile::current()->top()) {
578 // This node has just become top. Kill its out array.
579 _outcnt = _outmax = 0;
580 _out = NULL; // marker value for top
581 assert(is_top(), "must be top");
582 } else {
583 if (_out == NULL) _out = NO_OUT_ARRAY;
584 assert(!is_top(), "must not be top");
585 }
586 }
587
588
589 //------------------------------~Node------------------------------------------
590 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
591 extern int reclaim_idx ;
592 extern int reclaim_in ;
593 extern int reclaim_node;
594 void Node::destruct() {
595 // Eagerly reclaim unique Node numberings
596 Compile* compile = Compile::current();
597 if ((uint)_idx+1 == compile->unique()) {
598 compile->set_unique(compile->unique()-1);
599 #ifdef ASSERT
600 reclaim_idx++;
601 #endif
602 }
603 // Clear debug info:
604 Node_Notes* nn = compile->node_notes_at(_idx);
605 if (nn != NULL) nn->clear();
606 // Walk the input array, freeing the corresponding output edges
607 _cnt = _max; // forget req/prec distinction
608 uint i;
609 for( i = 0; i < _max; i++ ) {
610 set_req(i, NULL);
611 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
612 }
613 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
614 // See if the input array was allocated just prior to the object
615 int edge_size = _max*sizeof(void*);
616 int out_edge_size = _outmax*sizeof(void*);
617 char *edge_end = ((char*)_in) + edge_size;
618 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
619 char *out_edge_end = out_array + out_edge_size;
620 int node_size = size_of();
621
622 // Free the output edge array
623 if (out_edge_size > 0) {
624 #ifdef ASSERT
625 if( out_edge_end == compile->node_arena()->hwm() )
626 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
627 #endif
628 compile->node_arena()->Afree(out_array, out_edge_size);
629 }
630
631 // Free the input edge array and the node itself
632 if( edge_end == (char*)this ) {
633 #ifdef ASSERT
634 if( edge_end+node_size == compile->node_arena()->hwm() ) {
635 reclaim_in += edge_size;
636 reclaim_node+= node_size;
637 }
638 #else
639 // It was; free the input array and object all in one hit
640 compile->node_arena()->Afree(_in,edge_size+node_size);
641 #endif
642 } else {
643
644 // Free just the input array
645 #ifdef ASSERT
646 if( edge_end == compile->node_arena()->hwm() )
647 reclaim_in += edge_size;
648 #endif
649 compile->node_arena()->Afree(_in,edge_size);
650
651 // Free just the object
652 #ifdef ASSERT
653 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
654 reclaim_node+= node_size;
655 #else
656 compile->node_arena()->Afree(this,node_size);
657 #endif
658 }
659 if (is_macro()) {
660 compile->remove_macro_node(this);
661 }
662 if (is_expensive()) {
663 compile->remove_expensive_node(this);
664 }
665 CastIINode* cast = isa_CastII();
666 if (cast != NULL && cast->has_range_check()) {
667 compile->remove_range_check_cast(cast);
668 }
669
670 if (is_SafePoint()) {
671 as_SafePoint()->delete_replaced_nodes();
672 }
673 #ifdef ASSERT
674 // We will not actually delete the storage, but we'll make the node unusable.
675 *(address*)this = badAddress; // smash the C++ vtbl, probably
676 _in = _out = (Node**) badAddress;
677 _max = _cnt = _outmax = _outcnt = 0;
678 #endif
679 }
680
681 //------------------------------grow-------------------------------------------
682 // Grow the input array, making space for more edges
683 void Node::grow( uint len ) {
684 Arena* arena = Compile::current()->node_arena();
685 uint new_max = _max;
686 if( new_max == 0 ) {
687 _max = 4;
688 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
689 Node** to = _in;
690 to[0] = NULL;
691 to[1] = NULL;
692 to[2] = NULL;
693 to[3] = NULL;
694 return;
695 }
696 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
697 // Trimming to limit allows a uint8 to handle up to 255 edges.
698 // Previously I was using only powers-of-2 which peaked at 128 edges.
699 //if( new_max >= limit ) new_max = limit-1;
700 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
701 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
702 _max = new_max; // Record new max length
703 // This assertion makes sure that Node::_max is wide enough to
704 // represent the numerical value of new_max.
705 assert(_max == new_max && _max > len, "int width of _max is too small");
706 }
707
708 //-----------------------------out_grow----------------------------------------
709 // Grow the input array, making space for more edges
710 void Node::out_grow( uint len ) {
711 assert(!is_top(), "cannot grow a top node's out array");
712 Arena* arena = Compile::current()->node_arena();
713 uint new_max = _outmax;
714 if( new_max == 0 ) {
715 _outmax = 4;
716 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
717 return;
718 }
719 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
720 // Trimming to limit allows a uint8 to handle up to 255 edges.
721 // Previously I was using only powers-of-2 which peaked at 128 edges.
722 //if( new_max >= limit ) new_max = limit-1;
723 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
724 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
725 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
726 _outmax = new_max; // Record new max length
727 // This assertion makes sure that Node::_max is wide enough to
728 // represent the numerical value of new_max.
729 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
730 }
731
732 #ifdef ASSERT
733 //------------------------------is_dead----------------------------------------
734 bool Node::is_dead() const {
735 // Mach and pinch point nodes may look like dead.
736 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
737 return false;
738 for( uint i = 0; i < _max; i++ )
739 if( _in[i] != NULL )
740 return false;
741 dump();
742 return true;
743 }
744 #endif
745
746
747 //------------------------------is_unreachable---------------------------------
748 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
749 assert(!is_Mach(), "doesn't work with MachNodes");
750 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
751 }
752
753 //------------------------------add_req----------------------------------------
754 // Add a new required input at the end
755 void Node::add_req( Node *n ) {
756 assert( is_not_dead(n), "can not use dead node");
757
758 // Look to see if I can move precedence down one without reallocating
759 if( (_cnt >= _max) || (in(_max-1) != NULL) )
760 grow( _max+1 );
761
762 // Find a precedence edge to move
763 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
764 uint i;
765 for( i=_cnt; i<_max; i++ )
766 if( in(i) == NULL ) // Find the NULL at end of prec edge list
767 break; // There must be one, since we grew the array
768 _in[i] = in(_cnt); // Move prec over, making space for req edge
769 }
770 _in[_cnt++] = n; // Stuff over old prec edge
771 if (n != NULL) n->add_out((Node *)this);
772 }
773
774 //---------------------------add_req_batch-------------------------------------
775 // Add a new required input at the end
776 void Node::add_req_batch( Node *n, uint m ) {
777 assert( is_not_dead(n), "can not use dead node");
778 // check various edge cases
779 if ((int)m <= 1) {
780 assert((int)m >= 0, "oob");
781 if (m != 0) add_req(n);
782 return;
783 }
784
785 // Look to see if I can move precedence down one without reallocating
786 if( (_cnt+m) > _max || _in[_max-m] )
787 grow( _max+m );
788
789 // Find a precedence edge to move
790 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
791 uint i;
792 for( i=_cnt; i<_max; i++ )
793 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
794 break; // There must be one, since we grew the array
795 // Slide all the precs over by m positions (assume #prec << m).
796 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
797 }
798
799 // Stuff over the old prec edges
800 for(uint i=0; i<m; i++ ) {
801 _in[_cnt++] = n;
802 }
803
804 // Insert multiple out edges on the node.
805 if (n != NULL && !n->is_top()) {
806 for(uint i=0; i<m; i++ ) {
807 n->add_out((Node *)this);
808 }
809 }
810 }
811
812 //------------------------------del_req----------------------------------------
813 // Delete the required edge and compact the edge array
814 void Node::del_req( uint idx ) {
815 assert( idx < _cnt, "oob");
816 assert( !VerifyHashTableKeys || _hash_lock == 0,
817 "remove node from hash table before modifying it");
818 // First remove corresponding def-use edge
819 Node *n = in(idx);
820 if (n != NULL) n->del_out((Node *)this);
821 _in[idx] = in(--_cnt); // Compact the array
822 // Avoid spec violation: Gap in prec edges.
823 close_prec_gap_at(_cnt);
824 }
825
826 //------------------------------del_req_ordered--------------------------------
827 // Delete the required edge and compact the edge array with preserved order
828 void Node::del_req_ordered( uint idx ) {
829 assert( idx < _cnt, "oob");
830 assert( !VerifyHashTableKeys || _hash_lock == 0,
831 "remove node from hash table before modifying it");
832 // First remove corresponding def-use edge
833 Node *n = in(idx);
834 if (n != NULL) n->del_out((Node *)this);
835 if (idx < --_cnt) { // Not last edge ?
836 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
837 }
838 // Avoid spec violation: Gap in prec edges.
839 close_prec_gap_at(_cnt);
840 }
841
842 //------------------------------ins_req----------------------------------------
843 // Insert a new required input at the end
844 void Node::ins_req( uint idx, Node *n ) {
845 assert( is_not_dead(n), "can not use dead node");
846 add_req(NULL); // Make space
847 assert( idx < _max, "Must have allocated enough space");
848 // Slide over
849 if(_cnt-idx-1 > 0) {
850 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
851 }
852 _in[idx] = n; // Stuff over old required edge
853 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
854 }
855
856 //-----------------------------find_edge---------------------------------------
857 int Node::find_edge(Node* n) {
858 for (uint i = 0; i < len(); i++) {
859 if (_in[i] == n) return i;
860 }
861 return -1;
862 }
863
864 //----------------------------replace_edge-------------------------------------
865 int Node::replace_edge(Node* old, Node* neww) {
866 if (old == neww) return 0; // nothing to do
867 uint nrep = 0;
868 for (uint i = 0; i < len(); i++) {
869 if (in(i) == old) {
870 if (i < req()) {
871 set_req(i, neww);
872 } else {
873 assert(find_prec_edge(neww) == -1, err_msg("spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx));
874 set_prec(i, neww);
875 }
876 nrep++;
877 }
878 }
879 return nrep;
880 }
881
882 /**
883 * Replace input edges in the range pointing to 'old' node.
884 */
885 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
886 if (old == neww) return 0; // nothing to do
887 uint nrep = 0;
888 for (int i = start; i < end; i++) {
889 if (in(i) == old) {
890 set_req(i, neww);
891 nrep++;
892 }
893 }
894 return nrep;
895 }
896
897 //-------------------------disconnect_inputs-----------------------------------
898 // NULL out all inputs to eliminate incoming Def-Use edges.
899 // Return the number of edges between 'n' and 'this'
900 int Node::disconnect_inputs(Node *n, Compile* C) {
901 int edges_to_n = 0;
902
903 uint cnt = req();
904 for( uint i = 0; i < cnt; ++i ) {
905 if( in(i) == 0 ) continue;
906 if( in(i) == n ) ++edges_to_n;
907 set_req(i, NULL);
908 }
909 // Remove precedence edges if any exist
910 // Note: Safepoints may have precedence edges, even during parsing
911 if( (req() != len()) && (in(req()) != NULL) ) {
912 uint max = len();
913 for( uint i = 0; i < max; ++i ) {
914 if( in(i) == 0 ) continue;
915 if( in(i) == n ) ++edges_to_n;
916 set_prec(i, NULL);
917 }
918 }
919
920 // Node::destruct requires all out edges be deleted first
921 // debug_only(destruct();) // no reuse benefit expected
922 if (edges_to_n == 0) {
923 C->record_dead_node(_idx);
924 }
925 return edges_to_n;
926 }
927
928 //-----------------------------uncast---------------------------------------
929 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
930 // Strip away casting. (It is depth-limited.)
931 Node* Node::uncast() const {
932 // Should be inline:
933 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
934 if (is_ConstraintCast() || is_CheckCastPP())
935 return uncast_helper(this);
936 else
937 return (Node*) this;
938 }
939
940 // Find out of current node that matches opcode.
941 Node* Node::find_out_with(int opcode) {
942 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
943 Node* use = fast_out(i);
944 if (use->Opcode() == opcode) {
945 return use;
946 }
947 }
948 return NULL;
949 }
950
951 //---------------------------uncast_helper-------------------------------------
952 Node* Node::uncast_helper(const Node* p) {
953 #ifdef ASSERT
954 uint depth_count = 0;
955 const Node* orig_p = p;
956 #endif
957
958 while (true) {
959 #ifdef ASSERT
960 if (depth_count >= K) {
961 orig_p->dump(4);
962 if (p != orig_p)
963 p->dump(1);
964 }
965 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
966 #endif
967 if (p == NULL || p->req() != 2) {
968 break;
969 } else if (p->is_ConstraintCast()) {
970 p = p->in(1);
971 } else if (p->is_CheckCastPP()) {
972 p = p->in(1);
973 } else {
974 break;
975 }
976 }
977 return (Node*) p;
978 }
979
980 //------------------------------add_prec---------------------------------------
981 // Add a new precedence input. Precedence inputs are unordered, with
982 // duplicates removed and NULLs packed down at the end.
983 void Node::add_prec( Node *n ) {
984 assert( is_not_dead(n), "can not use dead node");
985
986 // Check for NULL at end
987 if( _cnt >= _max || in(_max-1) )
988 grow( _max+1 );
989
990 // Find a precedence edge to move
991 uint i = _cnt;
992 while( in(i) != NULL ) {
993 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
994 i++;
995 }
996 _in[i] = n; // Stuff prec edge over NULL
997 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
998
999 #ifdef ASSERT
1000 while ((++i)<_max) { assert(_in[i] == NULL, err_msg("spec violation: Gap in prec edges (node %d)", _idx)); }
1001 #endif
1002 }
1003
1004 //------------------------------rm_prec----------------------------------------
1005 // Remove a precedence input. Precedence inputs are unordered, with
1006 // duplicates removed and NULLs packed down at the end.
1007 void Node::rm_prec( uint j ) {
1008 assert(j < _max, err_msg("oob: i=%d, _max=%d", j, _max));
1009 assert(j >= _cnt, "not a precedence edge");
1010 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
1011 _in[j]->del_out((Node *)this);
1012 close_prec_gap_at(j);
1013 }
1014
1015 //------------------------------size_of----------------------------------------
1016 uint Node::size_of() const { return sizeof(*this); }
1017
1018 //------------------------------ideal_reg--------------------------------------
1019 uint Node::ideal_reg() const { return 0; }
1020
1021 //------------------------------jvms-------------------------------------------
1022 JVMState* Node::jvms() const { return NULL; }
1023
1024 #ifdef ASSERT
1025 //------------------------------jvms-------------------------------------------
1026 bool Node::verify_jvms(const JVMState* using_jvms) const {
1027 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1028 if (jvms == using_jvms) return true;
1029 }
1030 return false;
1031 }
1032
1033 //------------------------------init_NodeProperty------------------------------
1034 void Node::init_NodeProperty() {
1035 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1036 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1037 }
1038 #endif
1039
1040 //------------------------------format-----------------------------------------
1041 // Print as assembly
1042 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1043 //------------------------------emit-------------------------------------------
1044 // Emit bytes starting at parameter 'ptr'.
1045 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1046 //------------------------------size-------------------------------------------
1047 // Size of instruction in bytes
1048 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1049
1050 //------------------------------CFG Construction-------------------------------
1051 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1052 // Goto and Return.
1053 const Node *Node::is_block_proj() const { return 0; }
1054
1055 // Minimum guaranteed type
1056 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1057
1058
1059 //------------------------------raise_bottom_type------------------------------
1060 // Get the worst-case Type output for this Node.
1061 void Node::raise_bottom_type(const Type* new_type) {
1062 if (is_Type()) {
1063 TypeNode *n = this->as_Type();
1064 if (VerifyAliases) {
1065 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1066 }
1067 n->set_type(new_type);
1068 } else if (is_Load()) {
1069 LoadNode *n = this->as_Load();
1070 if (VerifyAliases) {
1071 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1072 }
1073 n->set_type(new_type);
1074 }
1075 }
1076
1077 //------------------------------Identity---------------------------------------
1078 // Return a node that the given node is equivalent to.
1079 Node *Node::Identity( PhaseTransform * ) {
1080 return this; // Default to no identities
1081 }
1082
1083 //------------------------------Value------------------------------------------
1084 // Compute a new Type for a node using the Type of the inputs.
1085 const Type *Node::Value( PhaseTransform * ) const {
1086 return bottom_type(); // Default to worst-case Type
1087 }
1088
1089 //------------------------------Ideal------------------------------------------
1090 //
1091 // 'Idealize' the graph rooted at this Node.
1092 //
1093 // In order to be efficient and flexible there are some subtle invariants
1094 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1095 // these invariants, although its too slow to have on by default. If you are
1096 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1097 //
1098 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1099 // pointer. If ANY change is made, it must return the root of the reshaped
1100 // graph - even if the root is the same Node. Example: swapping the inputs
1101 // to an AddINode gives the same answer and same root, but you still have to
1102 // return the 'this' pointer instead of NULL.
1103 //
1104 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1105 // Identity call to return an old Node; basically if Identity can find
1106 // another Node have the Ideal call make no change and return NULL.
1107 // Example: AddINode::Ideal must check for add of zero; in this case it
1108 // returns NULL instead of doing any graph reshaping.
1109 //
1110 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1111 // sharing there may be other users of the old Nodes relying on their current
1112 // semantics. Modifying them will break the other users.
1113 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1114 // "X+3" unchanged in case it is shared.
1115 //
1116 // If you modify the 'this' pointer's inputs, you should use
1117 // 'set_req'. If you are making a new Node (either as the new root or
1118 // some new internal piece) you may use 'init_req' to set the initial
1119 // value. You can make a new Node with either 'new' or 'clone'. In
1120 // either case, def-use info is correctly maintained.
1121 //
1122 // Example: reshape "(X+3)+4" into "X+7":
1123 // set_req(1, in(1)->in(1));
1124 // set_req(2, phase->intcon(7));
1125 // return this;
1126 // Example: reshape "X*4" into "X<<2"
1127 // return new (C) LShiftINode(in(1), phase->intcon(2));
1128 //
1129 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1130 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1131 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1132 // return new (C) AddINode(shift, in(1));
1133 //
1134 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1135 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1136 // The Right Thing with def-use info.
1137 //
1138 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1139 // graph uses the 'this' Node it must be the root. If you want a Node with
1140 // the same Opcode as the 'this' pointer use 'clone'.
1141 //
1142 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1143 return NULL; // Default to being Ideal already
1144 }
1145
1146 // Some nodes have specific Ideal subgraph transformations only if they are
1147 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1148 // for the transformations to happen.
1149 bool Node::has_special_unique_user() const {
1150 assert(outcnt() == 1, "match only for unique out");
1151 Node* n = unique_out();
1152 int op = Opcode();
1153 if( this->is_Store() ) {
1154 // Condition for back-to-back stores folding.
1155 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1156 } else if (this->is_Load() || this->is_DecodeN()) {
1157 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1158 return n->Opcode() == Op_MemBarAcquire;
1159 } else if( op == Op_AddL ) {
1160 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1161 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1162 } else if( op == Op_SubI || op == Op_SubL ) {
1163 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1164 return n->Opcode() == op && n->in(2) == this;
1165 }
1166 return false;
1167 };
1168
1169 //--------------------------find_exact_control---------------------------------
1170 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1171 Node* Node::find_exact_control(Node* ctrl) {
1172 if (ctrl == NULL && this->is_Region())
1173 ctrl = this->as_Region()->is_copy();
1174
1175 if (ctrl != NULL && ctrl->is_CatchProj()) {
1176 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1177 ctrl = ctrl->in(0);
1178 if (ctrl != NULL && !ctrl->is_top())
1179 ctrl = ctrl->in(0);
1180 }
1181
1182 if (ctrl != NULL && ctrl->is_Proj())
1183 ctrl = ctrl->in(0);
1184
1185 return ctrl;
1186 }
1187
1188 //--------------------------dominates------------------------------------------
1189 // Helper function for MemNode::all_controls_dominate().
1190 // Check if 'this' control node dominates or equal to 'sub' control node.
1191 // We already know that if any path back to Root or Start reaches 'this',
1192 // then all paths so, so this is a simple search for one example,
1193 // not an exhaustive search for a counterexample.
1194 bool Node::dominates(Node* sub, Node_List &nlist) {
1195 assert(this->is_CFG(), "expecting control");
1196 assert(sub != NULL && sub->is_CFG(), "expecting control");
1197
1198 // detect dead cycle without regions
1199 int iterations_without_region_limit = DominatorSearchLimit;
1200
1201 Node* orig_sub = sub;
1202 Node* dom = this;
1203 bool met_dom = false;
1204 nlist.clear();
1205
1206 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1207 // After seeing 'dom', continue up to Root or Start.
1208 // If we hit a region (backward split point), it may be a loop head.
1209 // Keep going through one of the region's inputs. If we reach the
1210 // same region again, go through a different input. Eventually we
1211 // will either exit through the loop head, or give up.
1212 // (If we get confused, break out and return a conservative 'false'.)
1213 while (sub != NULL) {
1214 if (sub->is_top()) break; // Conservative answer for dead code.
1215 if (sub == dom) {
1216 if (nlist.size() == 0) {
1217 // No Region nodes except loops were visited before and the EntryControl
1218 // path was taken for loops: it did not walk in a cycle.
1219 return true;
1220 } else if (met_dom) {
1221 break; // already met before: walk in a cycle
1222 } else {
1223 // Region nodes were visited. Continue walk up to Start or Root
1224 // to make sure that it did not walk in a cycle.
1225 met_dom = true; // first time meet
1226 iterations_without_region_limit = DominatorSearchLimit; // Reset
1227 }
1228 }
1229 if (sub->is_Start() || sub->is_Root()) {
1230 // Success if we met 'dom' along a path to Start or Root.
1231 // We assume there are no alternative paths that avoid 'dom'.
1232 // (This assumption is up to the caller to ensure!)
1233 return met_dom;
1234 }
1235 Node* up = sub->in(0);
1236 // Normalize simple pass-through regions and projections:
1237 up = sub->find_exact_control(up);
1238 // If sub == up, we found a self-loop. Try to push past it.
1239 if (sub == up && sub->is_Loop()) {
1240 // Take loop entry path on the way up to 'dom'.
1241 up = sub->in(1); // in(LoopNode::EntryControl);
1242 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1243 // Always take in(1) path on the way up to 'dom' for clone regions
1244 // (with only one input) or regions which merge > 2 paths
1245 // (usually used to merge fast/slow paths).
1246 up = sub->in(1);
1247 } else if (sub == up && sub->is_Region()) {
1248 // Try both paths for Regions with 2 input paths (it may be a loop head).
1249 // It could give conservative 'false' answer without information
1250 // which region's input is the entry path.
1251 iterations_without_region_limit = DominatorSearchLimit; // Reset
1252
1253 bool region_was_visited_before = false;
1254 // Was this Region node visited before?
1255 // If so, we have reached it because we accidentally took a
1256 // loop-back edge from 'sub' back into the body of the loop,
1257 // and worked our way up again to the loop header 'sub'.
1258 // So, take the first unexplored path on the way up to 'dom'.
1259 for (int j = nlist.size() - 1; j >= 0; j--) {
1260 intptr_t ni = (intptr_t)nlist.at(j);
1261 Node* visited = (Node*)(ni & ~1);
1262 bool visited_twice_already = ((ni & 1) != 0);
1263 if (visited == sub) {
1264 if (visited_twice_already) {
1265 // Visited 2 paths, but still stuck in loop body. Give up.
1266 return false;
1267 }
1268 // The Region node was visited before only once.
1269 // (We will repush with the low bit set, below.)
1270 nlist.remove(j);
1271 // We will find a new edge and re-insert.
1272 region_was_visited_before = true;
1273 break;
1274 }
1275 }
1276
1277 // Find an incoming edge which has not been seen yet; walk through it.
1278 assert(up == sub, "");
1279 uint skip = region_was_visited_before ? 1 : 0;
1280 for (uint i = 1; i < sub->req(); i++) {
1281 Node* in = sub->in(i);
1282 if (in != NULL && !in->is_top() && in != sub) {
1283 if (skip == 0) {
1284 up = in;
1285 break;
1286 }
1287 --skip; // skip this nontrivial input
1288 }
1289 }
1290
1291 // Set 0 bit to indicate that both paths were taken.
1292 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1293 }
1294
1295 if (up == sub) {
1296 break; // some kind of tight cycle
1297 }
1298 if (up == orig_sub && met_dom) {
1299 // returned back after visiting 'dom'
1300 break; // some kind of cycle
1301 }
1302 if (--iterations_without_region_limit < 0) {
1303 break; // dead cycle
1304 }
1305 sub = up;
1306 }
1307
1308 // Did not meet Root or Start node in pred. chain.
1309 // Conservative answer for dead code.
1310 return false;
1311 }
1312
1313 //------------------------------remove_dead_region-----------------------------
1314 // This control node is dead. Follow the subgraph below it making everything
1315 // using it dead as well. This will happen normally via the usual IterGVN
1316 // worklist but this call is more efficient. Do not update use-def info
1317 // inside the dead region, just at the borders.
1318 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1319 // Con's are a popular node to re-hit in the hash table again.
1320 if( dead->is_Con() ) return;
1321
1322 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1323 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1324 Node_List nstack(Thread::current()->resource_area());
1325
1326 Node *top = igvn->C->top();
1327 nstack.push(dead);
1328 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1329
1330 while (nstack.size() > 0) {
1331 dead = nstack.pop();
1332 if (dead->Opcode() == Op_SafePoint) {
1333 dead->as_SafePoint()->disconnect_from_root(igvn);
1334 }
1335 if (dead->outcnt() > 0) {
1336 // Keep dead node on stack until all uses are processed.
1337 nstack.push(dead);
1338 // For all Users of the Dead... ;-)
1339 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1340 Node* use = dead->last_out(k);
1341 igvn->hash_delete(use); // Yank from hash table prior to mod
1342 if (use->in(0) == dead) { // Found another dead node
1343 assert (!use->is_Con(), "Control for Con node should be Root node.");
1344 use->set_req(0, top); // Cut dead edge to prevent processing
1345 nstack.push(use); // the dead node again.
1346 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1347 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1348 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1349 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1350 use->set_req(0, top); // Cut self edge
1351 nstack.push(use);
1352 } else { // Else found a not-dead user
1353 // Dead if all inputs are top or null
1354 bool dead_use = !use->is_Root(); // Keep empty graph alive
1355 for (uint j = 1; j < use->req(); j++) {
1356 Node* in = use->in(j);
1357 if (in == dead) { // Turn all dead inputs into TOP
1358 use->set_req(j, top);
1359 } else if (in != NULL && !in->is_top()) {
1360 dead_use = false;
1361 }
1362 }
1363 if (dead_use) {
1364 if (use->is_Region()) {
1365 use->set_req(0, top); // Cut self edge
1366 }
1367 nstack.push(use);
1368 } else {
1369 igvn->_worklist.push(use);
1370 }
1371 }
1372 // Refresh the iterator, since any number of kills might have happened.
1373 k = dead->last_outs(kmin);
1374 }
1375 } else { // (dead->outcnt() == 0)
1376 // Done with outputs.
1377 igvn->hash_delete(dead);
1378 igvn->_worklist.remove(dead);
1379 igvn->set_type(dead, Type::TOP);
1380 if (dead->is_macro()) {
1381 igvn->C->remove_macro_node(dead);
1382 }
1383 if (dead->is_expensive()) {
1384 igvn->C->remove_expensive_node(dead);
1385 }
1386 CastIINode* cast = dead->isa_CastII();
1387 if (cast != NULL && cast->has_range_check()) {
1388 igvn->C->remove_range_check_cast(cast);
1389 }
1390 igvn->C->record_dead_node(dead->_idx);
1391 // Kill all inputs to the dead guy
1392 for (uint i=0; i < dead->req(); i++) {
1393 Node *n = dead->in(i); // Get input to dead guy
1394 if (n != NULL && !n->is_top()) { // Input is valid?
1395 dead->set_req(i, top); // Smash input away
1396 if (n->outcnt() == 0) { // Input also goes dead?
1397 if (!n->is_Con())
1398 nstack.push(n); // Clear it out as well
1399 } else if (n->outcnt() == 1 &&
1400 n->has_special_unique_user()) {
1401 igvn->add_users_to_worklist( n );
1402 } else if (n->outcnt() <= 2 && n->is_Store()) {
1403 // Push store's uses on worklist to enable folding optimization for
1404 // store/store and store/load to the same address.
1405 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1406 // and remove_globally_dead_node().
1407 igvn->add_users_to_worklist( n );
1408 }
1409 }
1410 }
1411 } // (dead->outcnt() == 0)
1412 } // while (nstack.size() > 0) for outputs
1413 return;
1414 }
1415
1416 //------------------------------remove_dead_region-----------------------------
1417 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1418 Node *n = in(0);
1419 if( !n ) return false;
1420 // Lost control into this guy? I.e., it became unreachable?
1421 // Aggressively kill all unreachable code.
1422 if (can_reshape && n->is_top()) {
1423 kill_dead_code(this, phase->is_IterGVN());
1424 return false; // Node is dead.
1425 }
1426
1427 if( n->is_Region() && n->as_Region()->is_copy() ) {
1428 Node *m = n->nonnull_req();
1429 set_req(0, m);
1430 return true;
1431 }
1432 return false;
1433 }
1434
1435 //------------------------------hash-------------------------------------------
1436 // Hash function over Nodes.
1437 uint Node::hash() const {
1438 uint sum = 0;
1439 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1440 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1441 return (sum>>2) + _cnt + Opcode();
1442 }
1443
1444 //------------------------------cmp--------------------------------------------
1445 // Compare special parts of simple Nodes
1446 uint Node::cmp( const Node &n ) const {
1447 return 1; // Must be same
1448 }
1449
1450 //------------------------------rematerialize-----------------------------------
1451 // Should we clone rather than spill this instruction?
1452 bool Node::rematerialize() const {
1453 if ( is_Mach() )
1454 return this->as_Mach()->rematerialize();
1455 else
1456 return (_flags & Flag_rematerialize) != 0;
1457 }
1458
1459 //------------------------------needs_anti_dependence_check---------------------
1460 // Nodes which use memory without consuming it, hence need antidependences.
1461 bool Node::needs_anti_dependence_check() const {
1462 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1463 return false;
1464 else
1465 return in(1)->bottom_type()->has_memory();
1466 }
1467
1468
1469 // Get an integer constant from a ConNode (or CastIINode).
1470 // Return a default value if there is no apparent constant here.
1471 const TypeInt* Node::find_int_type() const {
1472 if (this->is_Type()) {
1473 return this->as_Type()->type()->isa_int();
1474 } else if (this->is_Con()) {
1475 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1476 return this->bottom_type()->isa_int();
1477 }
1478 return NULL;
1479 }
1480
1481 // Get a pointer constant from a ConstNode.
1482 // Returns the constant if it is a pointer ConstNode
1483 intptr_t Node::get_ptr() const {
1484 assert( Opcode() == Op_ConP, "" );
1485 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1486 }
1487
1488 // Get a narrow oop constant from a ConNNode.
1489 intptr_t Node::get_narrowcon() const {
1490 assert( Opcode() == Op_ConN, "" );
1491 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1492 }
1493
1494 // Get a long constant from a ConNode.
1495 // Return a default value if there is no apparent constant here.
1496 const TypeLong* Node::find_long_type() const {
1497 if (this->is_Type()) {
1498 return this->as_Type()->type()->isa_long();
1499 } else if (this->is_Con()) {
1500 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1501 return this->bottom_type()->isa_long();
1502 }
1503 return NULL;
1504 }
1505
1506
1507 /**
1508 * Return a ptr type for nodes which should have it.
1509 */
1510 const TypePtr* Node::get_ptr_type() const {
1511 const TypePtr* tp = this->bottom_type()->make_ptr();
1512 #ifdef ASSERT
1513 if (tp == NULL) {
1514 this->dump(1);
1515 assert((tp != NULL), "unexpected node type");
1516 }
1517 #endif
1518 return tp;
1519 }
1520
1521 // Get a double constant from a ConstNode.
1522 // Returns the constant if it is a double ConstNode
1523 jdouble Node::getd() const {
1524 assert( Opcode() == Op_ConD, "" );
1525 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1526 }
1527
1528 // Get a float constant from a ConstNode.
1529 // Returns the constant if it is a float ConstNode
1530 jfloat Node::getf() const {
1531 assert( Opcode() == Op_ConF, "" );
1532 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1533 }
1534
1535 #ifndef PRODUCT
1536
1537 //----------------------------NotANode----------------------------------------
1538 // Used in debugging code to avoid walking across dead or uninitialized edges.
1539 static inline bool NotANode(const Node* n) {
1540 if (n == NULL) return true;
1541 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1542 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1543 return false;
1544 }
1545
1546
1547 //------------------------------find------------------------------------------
1548 // Find a neighbor of this Node with the given _idx
1549 // If idx is negative, find its absolute value, following both _in and _out.
1550 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1551 VectorSet* old_space, VectorSet* new_space ) {
1552 int node_idx = (idx >= 0) ? idx : -idx;
1553 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1554 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1555 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1556 if( v->test(n->_idx) ) return;
1557 if( (int)n->_idx == node_idx
1558 debug_only(|| n->debug_idx() == node_idx) ) {
1559 if (result != NULL)
1560 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1561 (uintptr_t)result, (uintptr_t)n, node_idx);
1562 result = n;
1563 }
1564 v->set(n->_idx);
1565 for( uint i=0; i<n->len(); i++ ) {
1566 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1567 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1568 }
1569 // Search along forward edges also:
1570 if (idx < 0 && !only_ctrl) {
1571 for( uint j=0; j<n->outcnt(); j++ ) {
1572 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1573 }
1574 }
1575 #ifdef ASSERT
1576 // Search along debug_orig edges last, checking for cycles
1577 Node* orig = n->debug_orig();
1578 if (orig != NULL) {
1579 do {
1580 if (NotANode(orig)) break;
1581 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1582 orig = orig->debug_orig();
1583 } while (orig != NULL && orig != n->debug_orig());
1584 }
1585 #endif //ASSERT
1586 }
1587
1588 // call this from debugger:
1589 Node* find_node(Node* n, int idx) {
1590 return n->find(idx);
1591 }
1592
1593 //------------------------------find-------------------------------------------
1594 Node* Node::find(int idx) const {
1595 ResourceArea *area = Thread::current()->resource_area();
1596 VectorSet old_space(area), new_space(area);
1597 Node* result = NULL;
1598 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1599 return result;
1600 }
1601
1602 //------------------------------find_ctrl--------------------------------------
1603 // Find an ancestor to this node in the control history with given _idx
1604 Node* Node::find_ctrl(int idx) const {
1605 ResourceArea *area = Thread::current()->resource_area();
1606 VectorSet old_space(area), new_space(area);
1607 Node* result = NULL;
1608 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1609 return result;
1610 }
1611 #endif
1612
1613
1614
1615 #ifndef PRODUCT
1616
1617 // -----------------------------Name-------------------------------------------
1618 extern const char *NodeClassNames[];
1619 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1620
1621 static bool is_disconnected(const Node* n) {
1622 for (uint i = 0; i < n->req(); i++) {
1623 if (n->in(i) != NULL) return false;
1624 }
1625 return true;
1626 }
1627
1628 #ifdef ASSERT
1629 static void dump_orig(Node* orig, outputStream *st) {
1630 Compile* C = Compile::current();
1631 if (NotANode(orig)) orig = NULL;
1632 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1633 if (orig == NULL) return;
1634 st->print(" !orig=");
1635 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1636 if (NotANode(fast)) fast = NULL;
1637 while (orig != NULL) {
1638 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1639 if (discon) st->print("[");
1640 if (!Compile::current()->node_arena()->contains(orig))
1641 st->print("o");
1642 st->print("%d", orig->_idx);
1643 if (discon) st->print("]");
1644 orig = orig->debug_orig();
1645 if (NotANode(orig)) orig = NULL;
1646 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1647 if (orig != NULL) st->print(",");
1648 if (fast != NULL) {
1649 // Step fast twice for each single step of orig:
1650 fast = fast->debug_orig();
1651 if (NotANode(fast)) fast = NULL;
1652 if (fast != NULL && fast != orig) {
1653 fast = fast->debug_orig();
1654 if (NotANode(fast)) fast = NULL;
1655 }
1656 if (fast == orig) {
1657 st->print("...");
1658 break;
1659 }
1660 }
1661 }
1662 }
1663
1664 void Node::set_debug_orig(Node* orig) {
1665 _debug_orig = orig;
1666 if (BreakAtNode == 0) return;
1667 if (NotANode(orig)) orig = NULL;
1668 int trip = 10;
1669 while (orig != NULL) {
1670 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1671 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1672 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1673 BREAKPOINT;
1674 }
1675 orig = orig->debug_orig();
1676 if (NotANode(orig)) orig = NULL;
1677 if (trip-- <= 0) break;
1678 }
1679 }
1680 #endif //ASSERT
1681
1682 //------------------------------dump------------------------------------------
1683 // Dump a Node
1684 void Node::dump(const char* suffix, outputStream *st) const {
1685 Compile* C = Compile::current();
1686 bool is_new = C->node_arena()->contains(this);
1687 C->_in_dump_cnt++;
1688 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1689
1690 // Dump the required and precedence inputs
1691 dump_req(st);
1692 dump_prec(st);
1693 // Dump the outputs
1694 dump_out(st);
1695
1696 if (is_disconnected(this)) {
1697 #ifdef ASSERT
1698 st->print(" [%d]",debug_idx());
1699 dump_orig(debug_orig(), st);
1700 #endif
1701 st->cr();
1702 C->_in_dump_cnt--;
1703 return; // don't process dead nodes
1704 }
1705
1706 // Dump node-specific info
1707 dump_spec(st);
1708 #ifdef ASSERT
1709 // Dump the non-reset _debug_idx
1710 if (Verbose && WizardMode) {
1711 st->print(" [%d]",debug_idx());
1712 }
1713 #endif
1714
1715 const Type *t = bottom_type();
1716
1717 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1718 const TypeInstPtr *toop = t->isa_instptr();
1719 const TypeKlassPtr *tkls = t->isa_klassptr();
1720 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1721 if (klass && klass->is_loaded() && klass->is_interface()) {
1722 st->print(" Interface:");
1723 } else if (toop) {
1724 st->print(" Oop:");
1725 } else if (tkls) {
1726 st->print(" Klass:");
1727 }
1728 t->dump_on(st);
1729 } else if (t == Type::MEMORY) {
1730 st->print(" Memory:");
1731 MemNode::dump_adr_type(this, adr_type(), st);
1732 } else if (Verbose || WizardMode) {
1733 st->print(" Type:");
1734 if (t) {
1735 t->dump_on(st);
1736 } else {
1737 st->print("no type");
1738 }
1739 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1740 // Dump MachSpillcopy vector type.
1741 t->dump_on(st);
1742 }
1743 if (is_new) {
1744 debug_only(dump_orig(debug_orig(), st));
1745 Node_Notes* nn = C->node_notes_at(_idx);
1746 if (nn != NULL && !nn->is_clear()) {
1747 if (nn->jvms() != NULL) {
1748 st->print(" !jvms:");
1749 nn->jvms()->dump_spec(st);
1750 }
1751 }
1752 }
1753 if (suffix) st->print("%s", suffix);
1754 C->_in_dump_cnt--;
1755 }
1756
1757 //------------------------------dump_req--------------------------------------
1758 void Node::dump_req(outputStream *st) const {
1759 // Dump the required input edges
1760 for (uint i = 0; i < req(); i++) { // For all required inputs
1761 Node* d = in(i);
1762 if (d == NULL) {
1763 st->print("_ ");
1764 } else if (NotANode(d)) {
1765 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1766 } else {
1767 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1768 }
1769 }
1770 }
1771
1772
1773 //------------------------------dump_prec-------------------------------------
1774 void Node::dump_prec(outputStream *st) const {
1775 // Dump the precedence edges
1776 int any_prec = 0;
1777 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1778 Node* p = in(i);
1779 if (p != NULL) {
1780 if (!any_prec++) st->print(" |");
1781 if (NotANode(p)) { st->print("NotANode "); continue; }
1782 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1783 }
1784 }
1785 }
1786
1787 //------------------------------dump_out--------------------------------------
1788 void Node::dump_out(outputStream *st) const {
1789 // Delimit the output edges
1790 st->print(" [[");
1791 // Dump the output edges
1792 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1793 Node* u = _out[i];
1794 if (u == NULL) {
1795 st->print("_ ");
1796 } else if (NotANode(u)) {
1797 st->print("NotANode ");
1798 } else {
1799 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1800 }
1801 }
1802 st->print("]] ");
1803 }
1804
1805 //------------------------------dump_nodes-------------------------------------
1806 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1807 Node* s = (Node*)start; // remove const
1808 if (NotANode(s)) return;
1809
1810 uint depth = (uint)ABS(d);
1811 int direction = d;
1812 Compile* C = Compile::current();
1813 GrowableArray <Node *> nstack(C->live_nodes());
1814
1815 nstack.append(s);
1816 int begin = 0;
1817 int end = 0;
1818 for(uint i = 0; i < depth; i++) {
1819 end = nstack.length();
1820 for(int j = begin; j < end; j++) {
1821 Node* tp = nstack.at(j);
1822 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1823 for(uint k = 0; k < limit; k++) {
1824 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1825
1826 if (NotANode(n)) continue;
1827 // do not recurse through top or the root (would reach unrelated stuff)
1828 if (n->is_Root() || n->is_top()) continue;
1829 if (only_ctrl && !n->is_CFG()) continue;
1830
1831 bool on_stack = nstack.contains(n);
1832 if (!on_stack) {
1833 nstack.append(n);
1834 }
1835 }
1836 }
1837 begin = end;
1838 }
1839 end = nstack.length();
1840 if (direction > 0) {
1841 for(int j = end-1; j >= 0; j--) {
1842 nstack.at(j)->dump();
1843 }
1844 } else {
1845 for(int j = 0; j < end; j++) {
1846 nstack.at(j)->dump();
1847 }
1848 }
1849 }
1850
1851 //------------------------------dump-------------------------------------------
1852 void Node::dump(int d) const {
1853 dump_nodes(this, d, false);
1854 }
1855
1856 //------------------------------dump_ctrl--------------------------------------
1857 // Dump a Node's control history to depth
1858 void Node::dump_ctrl(int d) const {
1859 dump_nodes(this, d, true);
1860 }
1861
1862 // VERIFICATION CODE
1863 // For each input edge to a node (ie - for each Use-Def edge), verify that
1864 // there is a corresponding Def-Use edge.
1865 //------------------------------verify_edges-----------------------------------
1866 void Node::verify_edges(Unique_Node_List &visited) {
1867 uint i, j, idx;
1868 int cnt;
1869 Node *n;
1870
1871 // Recursive termination test
1872 if (visited.member(this)) return;
1873 visited.push(this);
1874
1875 // Walk over all input edges, checking for correspondence
1876 for( i = 0; i < len(); i++ ) {
1877 n = in(i);
1878 if (n != NULL && !n->is_top()) {
1879 // Count instances of (Node *)this
1880 cnt = 0;
1881 for (idx = 0; idx < n->_outcnt; idx++ ) {
1882 if (n->_out[idx] == (Node *)this) cnt++;
1883 }
1884 assert( cnt > 0,"Failed to find Def-Use edge." );
1885 // Check for duplicate edges
1886 // walk the input array downcounting the input edges to n
1887 for( j = 0; j < len(); j++ ) {
1888 if( in(j) == n ) cnt--;
1889 }
1890 assert( cnt == 0,"Mismatched edge count.");
1891 } else if (n == NULL) {
1892 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1893 } else {
1894 assert(n->is_top(), "sanity");
1895 // Nothing to check.
1896 }
1897 }
1898 // Recursive walk over all input edges
1899 for( i = 0; i < len(); i++ ) {
1900 n = in(i);
1901 if( n != NULL )
1902 in(i)->verify_edges(visited);
1903 }
1904 }
1905
1906 //------------------------------verify_recur-----------------------------------
1907 static const Node *unique_top = NULL;
1908
1909 void Node::verify_recur(const Node *n, int verify_depth,
1910 VectorSet &old_space, VectorSet &new_space) {
1911 if ( verify_depth == 0 ) return;
1912 if (verify_depth > 0) --verify_depth;
1913
1914 Compile* C = Compile::current();
1915
1916 // Contained in new_space or old_space?
1917 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1918 // Check for visited in the proper space. Numberings are not unique
1919 // across spaces so we need a separate VectorSet for each space.
1920 if( v->test_set(n->_idx) ) return;
1921
1922 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1923 if (C->cached_top_node() == NULL)
1924 C->set_cached_top_node((Node*)n);
1925 assert(C->cached_top_node() == n, "TOP node must be unique");
1926 }
1927
1928 for( uint i = 0; i < n->len(); i++ ) {
1929 Node *x = n->in(i);
1930 if (!x || x->is_top()) continue;
1931
1932 // Verify my input has a def-use edge to me
1933 if (true /*VerifyDefUse*/) {
1934 // Count use-def edges from n to x
1935 int cnt = 0;
1936 for( uint j = 0; j < n->len(); j++ )
1937 if( n->in(j) == x )
1938 cnt++;
1939 // Count def-use edges from x to n
1940 uint max = x->_outcnt;
1941 for( uint k = 0; k < max; k++ )
1942 if (x->_out[k] == n)
1943 cnt--;
1944 assert( cnt == 0, "mismatched def-use edge counts" );
1945 }
1946
1947 verify_recur(x, verify_depth, old_space, new_space);
1948 }
1949
1950 }
1951
1952 //------------------------------verify-----------------------------------------
1953 // Check Def-Use info for my subgraph
1954 void Node::verify() const {
1955 Compile* C = Compile::current();
1956 Node* old_top = C->cached_top_node();
1957 ResourceMark rm;
1958 ResourceArea *area = Thread::current()->resource_area();
1959 VectorSet old_space(area), new_space(area);
1960 verify_recur(this, -1, old_space, new_space);
1961 C->set_cached_top_node(old_top);
1962 }
1963 #endif
1964
1965
1966 //------------------------------walk-------------------------------------------
1967 // Graph walk, with both pre-order and post-order functions
1968 void Node::walk(NFunc pre, NFunc post, void *env) {
1969 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1970 walk_(pre, post, env, visited);
1971 }
1972
1973 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1974 if( visited.test_set(_idx) ) return;
1975 pre(*this,env); // Call the pre-order walk function
1976 for( uint i=0; i<_max; i++ )
1977 if( in(i) ) // Input exists and is not walked?
1978 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1979 post(*this,env); // Call the post-order walk function
1980 }
1981
1982 void Node::nop(Node &, void*) {}
1983
1984 //------------------------------Registers--------------------------------------
1985 // Do we Match on this edge index or not? Generally false for Control
1986 // and true for everything else. Weird for calls & returns.
1987 uint Node::match_edge(uint idx) const {
1988 return idx; // True for other than index 0 (control)
1989 }
1990
1991 static RegMask _not_used_at_all;
1992 // Register classes are defined for specific machines
1993 const RegMask &Node::out_RegMask() const {
1994 ShouldNotCallThis();
1995 return _not_used_at_all;
1996 }
1997
1998 const RegMask &Node::in_RegMask(uint) const {
1999 ShouldNotCallThis();
2000 return _not_used_at_all;
2001 }
2002
2003 //=============================================================================
2004 //-----------------------------------------------------------------------------
2005 void Node_Array::reset( Arena *new_arena ) {
2006 _a->Afree(_nodes,_max*sizeof(Node*));
2007 _max = 0;
2008 _nodes = NULL;
2009 _a = new_arena;
2010 }
2011
2012 //------------------------------clear------------------------------------------
2013 // Clear all entries in _nodes to NULL but keep storage
2014 void Node_Array::clear() {
2015 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2016 }
2017
2018 //-----------------------------------------------------------------------------
2019 void Node_Array::grow( uint i ) {
2020 if( !_max ) {
2021 _max = 1;
2022 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2023 _nodes[0] = NULL;
2024 }
2025 uint old = _max;
2026 while( i >= _max ) _max <<= 1; // Double to fit
2027 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2028 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2029 }
2030
2031 //-----------------------------------------------------------------------------
2032 void Node_Array::insert( uint i, Node *n ) {
2033 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2034 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2035 _nodes[i] = n;
2036 }
2037
2038 //-----------------------------------------------------------------------------
2039 void Node_Array::remove( uint i ) {
2040 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2041 _nodes[_max-1] = NULL;
2042 }
2043
2044 //-----------------------------------------------------------------------------
2045 void Node_Array::sort( C_sort_func_t func) {
2046 qsort( _nodes, _max, sizeof( Node* ), func );
2047 }
2048
2049 //-----------------------------------------------------------------------------
2050 void Node_Array::dump() const {
2051 #ifndef PRODUCT
2052 for( uint i = 0; i < _max; i++ ) {
2053 Node *nn = _nodes[i];
2054 if( nn != NULL ) {
2055 tty->print("%5d--> ",i); nn->dump();
2056 }
2057 }
2058 #endif
2059 }
2060
2061 //--------------------------is_iteratively_computed------------------------------
2062 // Operation appears to be iteratively computed (such as an induction variable)
2063 // It is possible for this operation to return false for a loop-varying
2064 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2065 bool Node::is_iteratively_computed() {
2066 if (ideal_reg()) { // does operation have a result register?
2067 for (uint i = 1; i < req(); i++) {
2068 Node* n = in(i);
2069 if (n != NULL && n->is_Phi()) {
2070 for (uint j = 1; j < n->req(); j++) {
2071 if (n->in(j) == this) {
2072 return true;
2073 }
2074 }
2075 }
2076 }
2077 }
2078 return false;
2079 }
2080
2081 //--------------------------find_similar------------------------------
2082 // Return a node with opcode "opc" and same inputs as "this" if one can
2083 // be found; Otherwise return NULL;
2084 Node* Node::find_similar(int opc) {
2085 if (req() >= 2) {
2086 Node* def = in(1);
2087 if (def && def->outcnt() >= 2) {
2088 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2089 Node* use = def->fast_out(i);
2090 if (use->Opcode() == opc &&
2091 use->req() == req()) {
2092 uint j;
2093 for (j = 0; j < use->req(); j++) {
2094 if (use->in(j) != in(j)) {
2095 break;
2096 }
2097 }
2098 if (j == use->req()) {
2099 return use;
2100 }
2101 }
2102 }
2103 }
2104 }
2105 return NULL;
2106 }
2107
2108
2109 //--------------------------unique_ctrl_out------------------------------
2110 // Return the unique control out if only one. Null if none or more than one.
2111 Node* Node::unique_ctrl_out() {
2112 Node* found = NULL;
2113 for (uint i = 0; i < outcnt(); i++) {
2114 Node* use = raw_out(i);
2115 if (use->is_CFG() && use != this) {
2116 if (found != NULL) return NULL;
2117 found = use;
2118 }
2119 }
2120 return found;
2121 }
2122
2123 void Node::ensure_control_or_add_prec(Node* c) {
2124 if (in(0) == NULL) {
2125 set_req(0, c);
2126 } else if (in(0) != c) {
2127 add_prec(c);
2128 }
2129 }
2130
2131 //=============================================================================
2132 //------------------------------yank-------------------------------------------
2133 // Find and remove
2134 void Node_List::yank( Node *n ) {
2135 uint i;
2136 for( i = 0; i < _cnt; i++ )
2137 if( _nodes[i] == n )
2138 break;
2139
2140 if( i < _cnt )
2141 _nodes[i] = _nodes[--_cnt];
2142 }
2143
2144 //------------------------------dump-------------------------------------------
2145 void Node_List::dump() const {
2146 #ifndef PRODUCT
2147 for( uint i = 0; i < _cnt; i++ )
2148 if( _nodes[i] ) {
2149 tty->print("%5d--> ",i);
2150 _nodes[i]->dump();
2151 }
2152 #endif
2153 }
2154
2155 void Node_List::dump_simple() const {
2156 #ifndef PRODUCT
2157 for( uint i = 0; i < _cnt; i++ )
2158 if( _nodes[i] ) {
2159 tty->print(" %d", _nodes[i]->_idx);
2160 } else {
2161 tty->print(" NULL");
2162 }
2163 #endif
2164 }
2165
2166 //=============================================================================
2167 //------------------------------remove-----------------------------------------
2168 void Unique_Node_List::remove( Node *n ) {
2169 if( _in_worklist[n->_idx] ) {
2170 for( uint i = 0; i < size(); i++ )
2171 if( _nodes[i] == n ) {
2172 map(i,Node_List::pop());
2173 _in_worklist >>= n->_idx;
2174 return;
2175 }
2176 ShouldNotReachHere();
2177 }
2178 }
2179
2180 //-----------------------remove_useless_nodes----------------------------------
2181 // Remove useless nodes from worklist
2182 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2183
2184 for( uint i = 0; i < size(); ++i ) {
2185 Node *n = at(i);
2186 assert( n != NULL, "Did not expect null entries in worklist");
2187 if( ! useful.test(n->_idx) ) {
2188 _in_worklist >>= n->_idx;
2189 map(i,Node_List::pop());
2190 // Node *replacement = Node_List::pop();
2191 // if( i != size() ) { // Check if removing last entry
2192 // _nodes[i] = replacement;
2193 // }
2194 --i; // Visit popped node
2195 // If it was last entry, loop terminates since size() was also reduced
2196 }
2197 }
2198 }
2199
2200 //=============================================================================
2201 void Node_Stack::grow() {
2202 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2203 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2204 size_t max = old_max << 1; // max * 2
2205 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2206 _inode_max = _inodes + max;
2207 _inode_top = _inodes + old_top; // restore _top
2208 }
2209
2210 // Node_Stack is used to map nodes.
2211 Node* Node_Stack::find(uint idx) const {
2212 uint sz = size();
2213 for (uint i=0; i < sz; i++) {
2214 if (idx == index_at(i) )
2215 return node_at(i);
2216 }
2217 return NULL;
2218 }
2219
2220 //=============================================================================
2221 uint TypeNode::size_of() const { return sizeof(*this); }
2222 #ifndef PRODUCT
2223 void TypeNode::dump_spec(outputStream *st) const {
2224 if( !Verbose && !WizardMode ) {
2225 // standard dump does this in Verbose and WizardMode
2226 st->print(" #"); _type->dump_on(st);
2227 }
2228 }
2229 #endif
2230 uint TypeNode::hash() const {
2231 return Node::hash() + _type->hash();
2232 }
2233 uint TypeNode::cmp( const Node &n ) const
2234 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2235 const Type *TypeNode::bottom_type() const { return _type; }
2236 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2237
2238 //------------------------------ideal_reg--------------------------------------
2239 uint TypeNode::ideal_reg() const {
2240 return _type->ideal_reg();
2241 }