1 /*
2 * Copyright (c) 1997, 2013, 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/constnode.hpp"
30 #include "opto/machnode.hpp"
31 #include "opto/matcher.hpp"
32 #include "opto/node.hpp"
33 #include "opto/opcodes.hpp"
34 #include "opto/regmask.hpp"
35 #include "opto/type.hpp"
36 #include "utilities/copy.hpp"
37
38 class RegMask;
39 // #include "phase.hpp"
40 class PhaseTransform;
41 class PhaseGVN;
42
43 // Arena we are currently building Nodes in
44 const uint Node::NotAMachineReg = 0xffff0000;
45
46 #ifndef PRODUCT
47 extern int nodes_created;
48 #endif
49
50 #ifdef ASSERT
51
52 //-------------------------- construct_node------------------------------------
53 // Set a breakpoint here to identify where a particular node index is built.
54 void Node::verify_construction() {
55 _debug_orig = NULL;
56 int old_debug_idx = Compile::debug_idx();
57 int new_debug_idx = old_debug_idx+1;
58 if (new_debug_idx > 0) {
59 // Arrange that the lowest five decimal digits of _debug_idx
60 // will repeat those of _idx. In case this is somehow pathological,
61 // we continue to assign negative numbers (!) consecutively.
62 const int mod = 100000;
63 int bump = (int)(_idx - new_debug_idx) % mod;
64 if (bump < 0) bump += mod;
65 assert(bump >= 0 && bump < mod, "");
66 new_debug_idx += bump;
67 }
68 Compile::set_debug_idx(new_debug_idx);
69 set_debug_idx( new_debug_idx );
70 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
71 assert(Compile::current()->live_nodes() < (uint)MaxNodeLimit, "Live Node limit exceeded limit");
72 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
73 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
74 BREAKPOINT;
75 }
76 #if OPTO_DU_ITERATOR_ASSERT
77 _last_del = NULL;
78 _del_tick = 0;
79 #endif
80 _hash_lock = 0;
81 }
82
83
84 // #ifdef ASSERT ...
85
86 #if OPTO_DU_ITERATOR_ASSERT
87 void DUIterator_Common::sample(const Node* node) {
88 _vdui = VerifyDUIterators;
89 _node = node;
90 _outcnt = node->_outcnt;
91 _del_tick = node->_del_tick;
92 _last = NULL;
93 }
94
95 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
96 assert(_node == node, "consistent iterator source");
97 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
98 }
99
100 void DUIterator_Common::verify_resync() {
101 // Ensure that the loop body has just deleted the last guy produced.
102 const Node* node = _node;
103 // Ensure that at least one copy of the last-seen edge was deleted.
104 // Note: It is OK to delete multiple copies of the last-seen edge.
105 // Unfortunately, we have no way to verify that all the deletions delete
106 // that same edge. On this point we must use the Honor System.
107 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
108 assert(node->_last_del == _last, "must have deleted the edge just produced");
109 // We liked this deletion, so accept the resulting outcnt and tick.
110 _outcnt = node->_outcnt;
111 _del_tick = node->_del_tick;
112 }
113
114 void DUIterator_Common::reset(const DUIterator_Common& that) {
115 if (this == &that) return; // ignore assignment to self
116 if (!_vdui) {
117 // We need to initialize everything, overwriting garbage values.
118 _last = that._last;
119 _vdui = that._vdui;
120 }
121 // Note: It is legal (though odd) for an iterator over some node x
122 // to be reassigned to iterate over another node y. Some doubly-nested
123 // progress loops depend on being able to do this.
124 const Node* node = that._node;
125 // Re-initialize everything, except _last.
126 _node = node;
127 _outcnt = node->_outcnt;
128 _del_tick = node->_del_tick;
129 }
130
131 void DUIterator::sample(const Node* node) {
132 DUIterator_Common::sample(node); // Initialize the assertion data.
133 _refresh_tick = 0; // No refreshes have happened, as yet.
134 }
135
136 void DUIterator::verify(const Node* node, bool at_end_ok) {
137 DUIterator_Common::verify(node, at_end_ok);
138 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
139 }
140
141 void DUIterator::verify_increment() {
142 if (_refresh_tick & 1) {
143 // We have refreshed the index during this loop.
144 // Fix up _idx to meet asserts.
145 if (_idx > _outcnt) _idx = _outcnt;
146 }
147 verify(_node, true);
148 }
149
150 void DUIterator::verify_resync() {
151 // Note: We do not assert on _outcnt, because insertions are OK here.
152 DUIterator_Common::verify_resync();
153 // Make sure we are still in sync, possibly with no more out-edges:
154 verify(_node, true);
155 }
156
157 void DUIterator::reset(const DUIterator& that) {
158 if (this == &that) return; // self assignment is always a no-op
159 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
160 assert(that._idx == 0, "assign only the result of Node::outs()");
161 assert(_idx == that._idx, "already assigned _idx");
162 if (!_vdui) {
163 // We need to initialize everything, overwriting garbage values.
164 sample(that._node);
165 } else {
166 DUIterator_Common::reset(that);
167 if (_refresh_tick & 1) {
168 _refresh_tick++; // Clear the "was refreshed" flag.
169 }
170 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
171 }
172 }
173
174 void DUIterator::refresh() {
175 DUIterator_Common::sample(_node); // Re-fetch assertion data.
176 _refresh_tick |= 1; // Set the "was refreshed" flag.
177 }
178
179 void DUIterator::verify_finish() {
180 // If the loop has killed the node, do not require it to re-run.
181 if (_node->_outcnt == 0) _refresh_tick &= ~1;
182 // If this assert triggers, it means that a loop used refresh_out_pos
183 // to re-synch an iteration index, but the loop did not correctly
184 // re-run itself, using a "while (progress)" construct.
185 // This iterator enforces the rule that you must keep trying the loop
186 // until it "runs clean" without any need for refreshing.
187 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
188 }
189
190
191 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
192 DUIterator_Common::verify(node, at_end_ok);
193 Node** out = node->_out;
194 uint cnt = node->_outcnt;
195 assert(cnt == _outcnt, "no insertions allowed");
196 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
197 // This last check is carefully designed to work for NO_OUT_ARRAY.
198 }
199
200 void DUIterator_Fast::verify_limit() {
201 const Node* node = _node;
202 verify(node, true);
203 assert(_outp == node->_out + node->_outcnt, "limit still correct");
204 }
205
206 void DUIterator_Fast::verify_resync() {
207 const Node* node = _node;
208 if (_outp == node->_out + _outcnt) {
209 // Note that the limit imax, not the pointer i, gets updated with the
210 // exact count of deletions. (For the pointer it's always "--i".)
211 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
212 // This is a limit pointer, with a name like "imax".
213 // Fudge the _last field so that the common assert will be happy.
214 _last = (Node*) node->_last_del;
215 DUIterator_Common::verify_resync();
216 } else {
217 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
218 // A normal internal pointer.
219 DUIterator_Common::verify_resync();
220 // Make sure we are still in sync, possibly with no more out-edges:
221 verify(node, true);
222 }
223 }
224
225 void DUIterator_Fast::verify_relimit(uint n) {
226 const Node* node = _node;
227 assert((int)n > 0, "use imax -= n only with a positive count");
228 // This must be a limit pointer, with a name like "imax".
229 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
230 // The reported number of deletions must match what the node saw.
231 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
232 // Fudge the _last field so that the common assert will be happy.
233 _last = (Node*) node->_last_del;
234 DUIterator_Common::verify_resync();
235 }
236
237 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
238 assert(_outp == that._outp, "already assigned _outp");
239 DUIterator_Common::reset(that);
240 }
241
242 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
243 // at_end_ok means the _outp is allowed to underflow by 1
244 _outp += at_end_ok;
245 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
246 _outp -= at_end_ok;
247 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
248 }
249
250 void DUIterator_Last::verify_limit() {
251 // Do not require the limit address to be resynched.
252 //verify(node, true);
253 assert(_outp == _node->_out, "limit still correct");
254 }
255
256 void DUIterator_Last::verify_step(uint num_edges) {
257 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
258 _outcnt -= num_edges;
259 _del_tick += num_edges;
260 // Make sure we are still in sync, possibly with no more out-edges:
261 const Node* node = _node;
262 verify(node, true);
263 assert(node->_last_del == _last, "must have deleted the edge just produced");
264 }
265
266 #endif //OPTO_DU_ITERATOR_ASSERT
267
268
269 #endif //ASSERT
270
271
272 // This constant used to initialize _out may be any non-null value.
273 // The value NULL is reserved for the top node only.
274 #define NO_OUT_ARRAY ((Node**)-1)
275
276 // This funny expression handshakes with Node::operator new
277 // to pull Compile::current out of the new node's _out field,
278 // and then calls a subroutine which manages most field
279 // initializations. The only one which is tricky is the
280 // _idx field, which is const, and so must be initialized
281 // by a return value, not an assignment.
282 //
283 // (Aren't you thankful that Java finals don't require so many tricks?)
284 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
285 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
286 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
287 #endif
288 #ifdef __clang__
289 #pragma clang diagnostic push
290 #pragma GCC diagnostic ignored "-Wuninitialized"
291 #endif
292
293 // Out-of-line code from node constructors.
294 // Executed only when extra debug info. is being passed around.
295 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
296 C->set_node_notes_at(idx, nn);
297 }
298
299 // Shared initialization code.
300 inline int Node::Init(int req, Compile* C) {
301 assert(Compile::current() == C, "must use operator new(Compile*)");
302 int idx = C->next_unique();
303
304 // Allocate memory for the necessary number of edges.
305 if (req > 0) {
306 // Allocate space for _in array to have double alignment.
307 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
308 #ifdef ASSERT
309 _in[req-1] = this; // magic cookie for assertion check
310 #endif
311 }
312 // If there are default notes floating around, capture them:
313 Node_Notes* nn = C->default_node_notes();
314 if (nn != NULL) init_node_notes(C, idx, nn);
315
316 // Note: At this point, C is dead,
317 // and we begin to initialize the new Node.
318
319 _cnt = _max = req;
320 _outcnt = _outmax = 0;
321 _class_id = Class_Node;
322 _flags = 0;
323 _out = NO_OUT_ARRAY;
324 return idx;
325 }
326
327 //------------------------------Node-------------------------------------------
328 // Create a Node, with a given number of required edges.
329 Node::Node(uint req)
330 : _idx(IDX_INIT(req))
331 {
332 assert( req < (uint)(MaxNodeLimit - NodeLimitFudgeFactor), "Input limit exceeded" );
333 debug_only( verify_construction() );
334 NOT_PRODUCT(nodes_created++);
335 if (req == 0) {
336 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
337 _in = NULL;
338 } else {
339 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
340 Node** to = _in;
341 for(uint i = 0; i < req; i++) {
342 to[i] = NULL;
343 }
344 }
345 }
346
347 //------------------------------Node-------------------------------------------
348 Node::Node(Node *n0)
349 : _idx(IDX_INIT(1))
350 {
351 debug_only( verify_construction() );
352 NOT_PRODUCT(nodes_created++);
353 // Assert we allocated space for input array already
354 assert( _in[0] == this, "Must pass arg count to 'new'" );
355 assert( is_not_dead(n0), "can not use dead node");
356 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
357 }
358
359 //------------------------------Node-------------------------------------------
360 Node::Node(Node *n0, Node *n1)
361 : _idx(IDX_INIT(2))
362 {
363 debug_only( verify_construction() );
364 NOT_PRODUCT(nodes_created++);
365 // Assert we allocated space for input array already
366 assert( _in[1] == this, "Must pass arg count to 'new'" );
367 assert( is_not_dead(n0), "can not use dead node");
368 assert( is_not_dead(n1), "can not use dead node");
369 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
370 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
371 }
372
373 //------------------------------Node-------------------------------------------
374 Node::Node(Node *n0, Node *n1, Node *n2)
375 : _idx(IDX_INIT(3))
376 {
377 debug_only( verify_construction() );
378 NOT_PRODUCT(nodes_created++);
379 // Assert we allocated space for input array already
380 assert( _in[2] == this, "Must pass arg count to 'new'" );
381 assert( is_not_dead(n0), "can not use dead node");
382 assert( is_not_dead(n1), "can not use dead node");
383 assert( is_not_dead(n2), "can not use dead node");
384 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
385 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
386 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
387 }
388
389 //------------------------------Node-------------------------------------------
390 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
391 : _idx(IDX_INIT(4))
392 {
393 debug_only( verify_construction() );
394 NOT_PRODUCT(nodes_created++);
395 // Assert we allocated space for input array already
396 assert( _in[3] == this, "Must pass arg count to 'new'" );
397 assert( is_not_dead(n0), "can not use dead node");
398 assert( is_not_dead(n1), "can not use dead node");
399 assert( is_not_dead(n2), "can not use dead node");
400 assert( is_not_dead(n3), "can not use dead node");
401 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
402 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
403 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
404 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
405 }
406
407 //------------------------------Node-------------------------------------------
408 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
409 : _idx(IDX_INIT(5))
410 {
411 debug_only( verify_construction() );
412 NOT_PRODUCT(nodes_created++);
413 // Assert we allocated space for input array already
414 assert( _in[4] == this, "Must pass arg count to 'new'" );
415 assert( is_not_dead(n0), "can not use dead node");
416 assert( is_not_dead(n1), "can not use dead node");
417 assert( is_not_dead(n2), "can not use dead node");
418 assert( is_not_dead(n3), "can not use dead node");
419 assert( is_not_dead(n4), "can not use dead node");
420 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
421 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
422 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
423 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
424 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
425 }
426
427 //------------------------------Node-------------------------------------------
428 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
429 Node *n4, Node *n5)
430 : _idx(IDX_INIT(6))
431 {
432 debug_only( verify_construction() );
433 NOT_PRODUCT(nodes_created++);
434 // Assert we allocated space for input array already
435 assert( _in[5] == this, "Must pass arg count to 'new'" );
436 assert( is_not_dead(n0), "can not use dead node");
437 assert( is_not_dead(n1), "can not use dead node");
438 assert( is_not_dead(n2), "can not use dead node");
439 assert( is_not_dead(n3), "can not use dead node");
440 assert( is_not_dead(n4), "can not use dead node");
441 assert( is_not_dead(n5), "can not use dead node");
442 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
443 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
444 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
445 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
446 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
447 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
448 }
449
450 //------------------------------Node-------------------------------------------
451 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
452 Node *n4, Node *n5, Node *n6)
453 : _idx(IDX_INIT(7))
454 {
455 debug_only( verify_construction() );
456 NOT_PRODUCT(nodes_created++);
457 // Assert we allocated space for input array already
458 assert( _in[6] == this, "Must pass arg count to 'new'" );
459 assert( is_not_dead(n0), "can not use dead node");
460 assert( is_not_dead(n1), "can not use dead node");
461 assert( is_not_dead(n2), "can not use dead node");
462 assert( is_not_dead(n3), "can not use dead node");
463 assert( is_not_dead(n4), "can not use dead node");
464 assert( is_not_dead(n5), "can not use dead node");
465 assert( is_not_dead(n6), "can not use dead node");
466 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
467 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
468 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
469 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
470 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
471 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
472 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
473 }
474
475 #ifdef __clang__
476 #pragma clang diagnostic pop
477 #endif
478
479
480 //------------------------------clone------------------------------------------
481 // Clone a Node.
482 Node *Node::clone() const {
483 Compile* C = Compile::current();
484 uint s = size_of(); // Size of inherited Node
485 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
486 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
487 // Set the new input pointer array
488 n->_in = (Node**)(((char*)n)+s);
489 // Cannot share the old output pointer array, so kill it
490 n->_out = NO_OUT_ARRAY;
491 // And reset the counters to 0
492 n->_outcnt = 0;
493 n->_outmax = 0;
494 // Unlock this guy, since he is not in any hash table.
495 debug_only(n->_hash_lock = 0);
496 // Walk the old node's input list to duplicate its edges
497 uint i;
498 for( i = 0; i < len(); i++ ) {
499 Node *x = in(i);
500 n->_in[i] = x;
501 if (x != NULL) x->add_out(n);
502 }
503 if (is_macro())
504 C->add_macro_node(n);
505 if (is_expensive())
506 C->add_expensive_node(n);
507
508 n->set_idx(C->next_unique()); // Get new unique index as well
509 debug_only( n->verify_construction() );
510 NOT_PRODUCT(nodes_created++);
511 // Do not patch over the debug_idx of a clone, because it makes it
512 // impossible to break on the clone's moment of creation.
513 //debug_only( n->set_debug_idx( debug_idx() ) );
514
515 C->copy_node_notes_to(n, (Node*) this);
516
517 // MachNode clone
518 uint nopnds;
519 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
520 MachNode *mach = n->as_Mach();
521 MachNode *mthis = this->as_Mach();
522 // Get address of _opnd_array.
523 // It should be the same offset since it is the clone of this node.
524 MachOper **from = mthis->_opnds;
525 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
526 pointer_delta((const void*)from,
527 (const void*)(&mthis->_opnds), 1));
528 mach->_opnds = to;
529 for ( uint i = 0; i < nopnds; ++i ) {
530 to[i] = from[i]->clone(C);
531 }
532 }
533 // cloning CallNode may need to clone JVMState
534 if (n->is_Call()) {
535 n->as_Call()->clone_jvms(C);
536 }
537 return n; // Return the clone
538 }
539
540 //---------------------------setup_is_top--------------------------------------
541 // Call this when changing the top node, to reassert the invariants
542 // required by Node::is_top. See Compile::set_cached_top_node.
543 void Node::setup_is_top() {
544 if (this == (Node*)Compile::current()->top()) {
545 // This node has just become top. Kill its out array.
546 _outcnt = _outmax = 0;
547 _out = NULL; // marker value for top
548 assert(is_top(), "must be top");
549 } else {
550 if (_out == NULL) _out = NO_OUT_ARRAY;
551 assert(!is_top(), "must not be top");
552 }
553 }
554
555
556 //------------------------------~Node------------------------------------------
557 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
558 extern int reclaim_idx ;
559 extern int reclaim_in ;
560 extern int reclaim_node;
561 void Node::destruct() {
562 // Eagerly reclaim unique Node numberings
563 Compile* compile = Compile::current();
564 if ((uint)_idx+1 == compile->unique()) {
565 compile->set_unique(compile->unique()-1);
566 #ifdef ASSERT
567 reclaim_idx++;
568 #endif
569 }
570 // Clear debug info:
571 Node_Notes* nn = compile->node_notes_at(_idx);
572 if (nn != NULL) nn->clear();
573 // Walk the input array, freeing the corresponding output edges
574 _cnt = _max; // forget req/prec distinction
575 uint i;
576 for( i = 0; i < _max; i++ ) {
577 set_req(i, NULL);
578 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
579 }
580 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
581 // See if the input array was allocated just prior to the object
582 int edge_size = _max*sizeof(void*);
583 int out_edge_size = _outmax*sizeof(void*);
584 char *edge_end = ((char*)_in) + edge_size;
585 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
586 char *out_edge_end = out_array + out_edge_size;
587 int node_size = size_of();
588
589 // Free the output edge array
590 if (out_edge_size > 0) {
591 #ifdef ASSERT
592 if( out_edge_end == compile->node_arena()->hwm() )
593 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
594 #endif
595 compile->node_arena()->Afree(out_array, out_edge_size);
596 }
597
598 // Free the input edge array and the node itself
599 if( edge_end == (char*)this ) {
600 #ifdef ASSERT
601 if( edge_end+node_size == compile->node_arena()->hwm() ) {
602 reclaim_in += edge_size;
603 reclaim_node+= node_size;
604 }
605 #else
606 // It was; free the input array and object all in one hit
607 compile->node_arena()->Afree(_in,edge_size+node_size);
608 #endif
609 } else {
610
611 // Free just the input array
612 #ifdef ASSERT
613 if( edge_end == compile->node_arena()->hwm() )
614 reclaim_in += edge_size;
615 #endif
616 compile->node_arena()->Afree(_in,edge_size);
617
618 // Free just the object
619 #ifdef ASSERT
620 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
621 reclaim_node+= node_size;
622 #else
623 compile->node_arena()->Afree(this,node_size);
624 #endif
625 }
626 if (is_macro()) {
627 compile->remove_macro_node(this);
628 }
629 if (is_expensive()) {
630 compile->remove_expensive_node(this);
631 }
632 #ifdef ASSERT
633 // We will not actually delete the storage, but we'll make the node unusable.
634 *(address*)this = badAddress; // smash the C++ vtbl, probably
635 _in = _out = (Node**) badAddress;
636 _max = _cnt = _outmax = _outcnt = 0;
637 #endif
638 }
639
640 //------------------------------grow-------------------------------------------
641 // Grow the input array, making space for more edges
642 void Node::grow( uint len ) {
643 Arena* arena = Compile::current()->node_arena();
644 uint new_max = _max;
645 if( new_max == 0 ) {
646 _max = 4;
647 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
648 Node** to = _in;
649 to[0] = NULL;
650 to[1] = NULL;
651 to[2] = NULL;
652 to[3] = NULL;
653 return;
654 }
655 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
656 // Trimming to limit allows a uint8 to handle up to 255 edges.
657 // Previously I was using only powers-of-2 which peaked at 128 edges.
658 //if( new_max >= limit ) new_max = limit-1;
659 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
660 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
661 _max = new_max; // Record new max length
662 // This assertion makes sure that Node::_max is wide enough to
663 // represent the numerical value of new_max.
664 assert(_max == new_max && _max > len, "int width of _max is too small");
665 }
666
667 //-----------------------------out_grow----------------------------------------
668 // Grow the input array, making space for more edges
669 void Node::out_grow( uint len ) {
670 assert(!is_top(), "cannot grow a top node's out array");
671 Arena* arena = Compile::current()->node_arena();
672 uint new_max = _outmax;
673 if( new_max == 0 ) {
674 _outmax = 4;
675 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
676 return;
677 }
678 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
679 // Trimming to limit allows a uint8 to handle up to 255 edges.
680 // Previously I was using only powers-of-2 which peaked at 128 edges.
681 //if( new_max >= limit ) new_max = limit-1;
682 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
683 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
684 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
685 _outmax = new_max; // Record new max length
686 // This assertion makes sure that Node::_max is wide enough to
687 // represent the numerical value of new_max.
688 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
689 }
690
691 #ifdef ASSERT
692 //------------------------------is_dead----------------------------------------
693 bool Node::is_dead() const {
694 // Mach and pinch point nodes may look like dead.
695 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
696 return false;
697 for( uint i = 0; i < _max; i++ )
698 if( _in[i] != NULL )
699 return false;
700 dump();
701 return true;
702 }
703 #endif
704
705
706 //------------------------------is_unreachable---------------------------------
707 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
708 assert(!is_Mach(), "doesn't work with MachNodes");
709 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
710 }
711
712 //------------------------------add_req----------------------------------------
713 // Add a new required input at the end
714 void Node::add_req( Node *n ) {
715 assert( is_not_dead(n), "can not use dead node");
716
717 // Look to see if I can move precedence down one without reallocating
718 if( (_cnt >= _max) || (in(_max-1) != NULL) )
719 grow( _max+1 );
720
721 // Find a precedence edge to move
722 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
723 uint i;
724 for( i=_cnt; i<_max; i++ )
725 if( in(i) == NULL ) // Find the NULL at end of prec edge list
726 break; // There must be one, since we grew the array
727 _in[i] = in(_cnt); // Move prec over, making space for req edge
728 }
729 _in[_cnt++] = n; // Stuff over old prec edge
730 if (n != NULL) n->add_out((Node *)this);
731 }
732
733 //---------------------------add_req_batch-------------------------------------
734 // Add a new required input at the end
735 void Node::add_req_batch( Node *n, uint m ) {
736 assert( is_not_dead(n), "can not use dead node");
737 // check various edge cases
738 if ((int)m <= 1) {
739 assert((int)m >= 0, "oob");
740 if (m != 0) add_req(n);
741 return;
742 }
743
744 // Look to see if I can move precedence down one without reallocating
745 if( (_cnt+m) > _max || _in[_max-m] )
746 grow( _max+m );
747
748 // Find a precedence edge to move
749 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
750 uint i;
751 for( i=_cnt; i<_max; i++ )
752 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
753 break; // There must be one, since we grew the array
754 // Slide all the precs over by m positions (assume #prec << m).
755 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
756 }
757
758 // Stuff over the old prec edges
759 for(uint i=0; i<m; i++ ) {
760 _in[_cnt++] = n;
761 }
762
763 // Insert multiple out edges on the node.
764 if (n != NULL && !n->is_top()) {
765 for(uint i=0; i<m; i++ ) {
766 n->add_out((Node *)this);
767 }
768 }
769 }
770
771 //------------------------------del_req----------------------------------------
772 // Delete the required edge and compact the edge array
773 void Node::del_req( uint idx ) {
774 assert( idx < _cnt, "oob");
775 assert( !VerifyHashTableKeys || _hash_lock == 0,
776 "remove node from hash table before modifying it");
777 // First remove corresponding def-use edge
778 Node *n = in(idx);
779 if (n != NULL) n->del_out((Node *)this);
780 _in[idx] = in(--_cnt); // Compact the array
781 _in[_cnt] = NULL; // NULL out emptied slot
782 }
783
784 //------------------------------del_req_ordered--------------------------------
785 // Delete the required edge and compact the edge array with preserved order
786 void Node::del_req_ordered( uint idx ) {
787 assert( idx < _cnt, "oob");
788 assert( !VerifyHashTableKeys || _hash_lock == 0,
789 "remove node from hash table before modifying it");
790 // First remove corresponding def-use edge
791 Node *n = in(idx);
792 if (n != NULL) n->del_out((Node *)this);
793 if (idx < _cnt - 1) { // Not last edge ?
794 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
795 }
796 _in[--_cnt] = NULL; // NULL out emptied slot
797 }
798
799 //------------------------------ins_req----------------------------------------
800 // Insert a new required input at the end
801 void Node::ins_req( uint idx, Node *n ) {
802 assert( is_not_dead(n), "can not use dead node");
803 add_req(NULL); // Make space
804 assert( idx < _max, "Must have allocated enough space");
805 // Slide over
806 if(_cnt-idx-1 > 0) {
807 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
808 }
809 _in[idx] = n; // Stuff over old required edge
810 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
811 }
812
813 //-----------------------------find_edge---------------------------------------
814 int Node::find_edge(Node* n) {
815 for (uint i = 0; i < len(); i++) {
816 if (_in[i] == n) return i;
817 }
818 return -1;
819 }
820
821 //----------------------------replace_edge-------------------------------------
822 int Node::replace_edge(Node* old, Node* neww) {
823 if (old == neww) return 0; // nothing to do
824 uint nrep = 0;
825 for (uint i = 0; i < len(); i++) {
826 if (in(i) == old) {
827 if (i < req())
828 set_req(i, neww);
829 else
830 set_prec(i, neww);
831 nrep++;
832 }
833 }
834 return nrep;
835 }
836
837 /**
838 * Replace input edges in the range pointing to 'old' node.
839 */
840 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
841 if (old == neww) return 0; // nothing to do
842 uint nrep = 0;
843 for (int i = start; i < end; i++) {
844 if (in(i) == old) {
845 set_req(i, neww);
846 nrep++;
847 }
848 }
849 return nrep;
850 }
851
852 //-------------------------disconnect_inputs-----------------------------------
853 // NULL out all inputs to eliminate incoming Def-Use edges.
854 // Return the number of edges between 'n' and 'this'
855 int Node::disconnect_inputs(Node *n, Compile* C) {
856 int edges_to_n = 0;
857
858 uint cnt = req();
859 for( uint i = 0; i < cnt; ++i ) {
860 if( in(i) == 0 ) continue;
861 if( in(i) == n ) ++edges_to_n;
862 set_req(i, NULL);
863 }
864 // Remove precedence edges if any exist
865 // Note: Safepoints may have precedence edges, even during parsing
866 if( (req() != len()) && (in(req()) != NULL) ) {
867 uint max = len();
868 for( uint i = 0; i < max; ++i ) {
869 if( in(i) == 0 ) continue;
870 if( in(i) == n ) ++edges_to_n;
871 set_prec(i, NULL);
872 }
873 }
874
875 // Node::destruct requires all out edges be deleted first
876 // debug_only(destruct();) // no reuse benefit expected
877 if (edges_to_n == 0) {
878 C->record_dead_node(_idx);
879 }
880 return edges_to_n;
881 }
882
883 //-----------------------------uncast---------------------------------------
884 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
885 // Strip away casting. (It is depth-limited.)
886 Node* Node::uncast() const {
887 // Should be inline:
888 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
889 if (is_ConstraintCast() || is_CheckCastPP())
890 return uncast_helper(this);
891 else
892 return (Node*) this;
893 }
894
895 //---------------------------uncast_helper-------------------------------------
896 Node* Node::uncast_helper(const Node* p) {
897 #ifdef ASSERT
898 uint depth_count = 0;
899 const Node* orig_p = p;
900 #endif
901
902 while (true) {
903 #ifdef ASSERT
904 if (depth_count >= K) {
905 orig_p->dump(4);
906 if (p != orig_p)
907 p->dump(1);
908 }
909 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
910 #endif
911 if (p == NULL || p->req() != 2) {
912 break;
913 } else if (p->is_ConstraintCast()) {
914 p = p->in(1);
915 } else if (p->is_CheckCastPP()) {
916 p = p->in(1);
917 } else {
918 break;
919 }
920 }
921 return (Node*) p;
922 }
923
924 //------------------------------add_prec---------------------------------------
925 // Add a new precedence input. Precedence inputs are unordered, with
926 // duplicates removed and NULLs packed down at the end.
927 void Node::add_prec( Node *n ) {
928 assert( is_not_dead(n), "can not use dead node");
929
930 // Check for NULL at end
931 if( _cnt >= _max || in(_max-1) )
932 grow( _max+1 );
933
934 // Find a precedence edge to move
935 uint i = _cnt;
936 while( in(i) != NULL ) i++;
937 _in[i] = n; // Stuff prec edge over NULL
938 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
939 }
940
941 //------------------------------rm_prec----------------------------------------
942 // Remove a precedence input. Precedence inputs are unordered, with
943 // duplicates removed and NULLs packed down at the end.
944 void Node::rm_prec( uint j ) {
945
946 // Find end of precedence list to pack NULLs
947 uint i;
948 for( i=j; i<_max; i++ )
949 if( !_in[i] ) // Find the NULL at end of prec edge list
950 break;
951 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
952 _in[j] = _in[--i]; // Move last element over removed guy
953 _in[i] = NULL; // NULL out last element
954 }
955
956 //------------------------------size_of----------------------------------------
957 uint Node::size_of() const { return sizeof(*this); }
958
959 //------------------------------ideal_reg--------------------------------------
960 uint Node::ideal_reg() const { return 0; }
961
962 //------------------------------jvms-------------------------------------------
963 JVMState* Node::jvms() const { return NULL; }
964
965 #ifdef ASSERT
966 //------------------------------jvms-------------------------------------------
967 bool Node::verify_jvms(const JVMState* using_jvms) const {
968 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
969 if (jvms == using_jvms) return true;
970 }
971 return false;
972 }
973
974 //------------------------------init_NodeProperty------------------------------
975 void Node::init_NodeProperty() {
976 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
977 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
978 }
979 #endif
980
981 //------------------------------format-----------------------------------------
982 // Print as assembly
983 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
984 //------------------------------emit-------------------------------------------
985 // Emit bytes starting at parameter 'ptr'.
986 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
987 //------------------------------size-------------------------------------------
988 // Size of instruction in bytes
989 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
990
991 //------------------------------CFG Construction-------------------------------
992 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
993 // Goto and Return.
994 const Node *Node::is_block_proj() const { return 0; }
995
996 // Minimum guaranteed type
997 const Type *Node::bottom_type() const { return Type::BOTTOM; }
998
999
1000 //------------------------------raise_bottom_type------------------------------
1001 // Get the worst-case Type output for this Node.
1002 void Node::raise_bottom_type(const Type* new_type) {
1003 if (is_Type()) {
1004 TypeNode *n = this->as_Type();
1005 if (VerifyAliases) {
1006 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1007 }
1008 n->set_type(new_type);
1009 } else if (is_Load()) {
1010 LoadNode *n = this->as_Load();
1011 if (VerifyAliases) {
1012 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1013 }
1014 n->set_type(new_type);
1015 }
1016 }
1017
1018 //------------------------------Identity---------------------------------------
1019 // Return a node that the given node is equivalent to.
1020 Node *Node::Identity( PhaseTransform * ) {
1021 return this; // Default to no identities
1022 }
1023
1024 //------------------------------Value------------------------------------------
1025 // Compute a new Type for a node using the Type of the inputs.
1026 const Type *Node::Value( PhaseTransform * ) const {
1027 return bottom_type(); // Default to worst-case Type
1028 }
1029
1030 //------------------------------Ideal------------------------------------------
1031 //
1032 // 'Idealize' the graph rooted at this Node.
1033 //
1034 // In order to be efficient and flexible there are some subtle invariants
1035 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1036 // these invariants, although its too slow to have on by default. If you are
1037 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1038 //
1039 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1040 // pointer. If ANY change is made, it must return the root of the reshaped
1041 // graph - even if the root is the same Node. Example: swapping the inputs
1042 // to an AddINode gives the same answer and same root, but you still have to
1043 // return the 'this' pointer instead of NULL.
1044 //
1045 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1046 // Identity call to return an old Node; basically if Identity can find
1047 // another Node have the Ideal call make no change and return NULL.
1048 // Example: AddINode::Ideal must check for add of zero; in this case it
1049 // returns NULL instead of doing any graph reshaping.
1050 //
1051 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1052 // sharing there may be other users of the old Nodes relying on their current
1053 // semantics. Modifying them will break the other users.
1054 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1055 // "X+3" unchanged in case it is shared.
1056 //
1057 // If you modify the 'this' pointer's inputs, you should use
1058 // 'set_req'. If you are making a new Node (either as the new root or
1059 // some new internal piece) you may use 'init_req' to set the initial
1060 // value. You can make a new Node with either 'new' or 'clone'. In
1061 // either case, def-use info is correctly maintained.
1062 //
1063 // Example: reshape "(X+3)+4" into "X+7":
1064 // set_req(1, in(1)->in(1));
1065 // set_req(2, phase->intcon(7));
1066 // return this;
1067 // Example: reshape "X*4" into "X<<2"
1068 // return new (C) LShiftINode(in(1), phase->intcon(2));
1069 //
1070 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1071 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1072 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1073 // return new (C) AddINode(shift, in(1));
1074 //
1075 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1076 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1077 // The Right Thing with def-use info.
1078 //
1079 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1080 // graph uses the 'this' Node it must be the root. If you want a Node with
1081 // the same Opcode as the 'this' pointer use 'clone'.
1082 //
1083 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1084 return NULL; // Default to being Ideal already
1085 }
1086
1087 // Some nodes have specific Ideal subgraph transformations only if they are
1088 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1089 // for the transformations to happen.
1090 bool Node::has_special_unique_user() const {
1091 assert(outcnt() == 1, "match only for unique out");
1092 Node* n = unique_out();
1093 int op = Opcode();
1094 if( this->is_Store() ) {
1095 // Condition for back-to-back stores folding.
1096 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1097 } else if( op == Op_AddL ) {
1098 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1099 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1100 } else if( op == Op_SubI || op == Op_SubL ) {
1101 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1102 return n->Opcode() == op && n->in(2) == this;
1103 }
1104 return false;
1105 };
1106
1107 //--------------------------find_exact_control---------------------------------
1108 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1109 Node* Node::find_exact_control(Node* ctrl) {
1110 if (ctrl == NULL && this->is_Region())
1111 ctrl = this->as_Region()->is_copy();
1112
1113 if (ctrl != NULL && ctrl->is_CatchProj()) {
1114 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1115 ctrl = ctrl->in(0);
1116 if (ctrl != NULL && !ctrl->is_top())
1117 ctrl = ctrl->in(0);
1118 }
1119
1120 if (ctrl != NULL && ctrl->is_Proj())
1121 ctrl = ctrl->in(0);
1122
1123 return ctrl;
1124 }
1125
1126 //--------------------------dominates------------------------------------------
1127 // Helper function for MemNode::all_controls_dominate().
1128 // Check if 'this' control node dominates or equal to 'sub' control node.
1129 // We already know that if any path back to Root or Start reaches 'this',
1130 // then all paths so, so this is a simple search for one example,
1131 // not an exhaustive search for a counterexample.
1132 bool Node::dominates(Node* sub, Node_List &nlist) {
1133 assert(this->is_CFG(), "expecting control");
1134 assert(sub != NULL && sub->is_CFG(), "expecting control");
1135
1136 // detect dead cycle without regions
1137 int iterations_without_region_limit = DominatorSearchLimit;
1138
1139 Node* orig_sub = sub;
1140 Node* dom = this;
1141 bool met_dom = false;
1142 nlist.clear();
1143
1144 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1145 // After seeing 'dom', continue up to Root or Start.
1146 // If we hit a region (backward split point), it may be a loop head.
1147 // Keep going through one of the region's inputs. If we reach the
1148 // same region again, go through a different input. Eventually we
1149 // will either exit through the loop head, or give up.
1150 // (If we get confused, break out and return a conservative 'false'.)
1151 while (sub != NULL) {
1152 if (sub->is_top()) break; // Conservative answer for dead code.
1153 if (sub == dom) {
1154 if (nlist.size() == 0) {
1155 // No Region nodes except loops were visited before and the EntryControl
1156 // path was taken for loops: it did not walk in a cycle.
1157 return true;
1158 } else if (met_dom) {
1159 break; // already met before: walk in a cycle
1160 } else {
1161 // Region nodes were visited. Continue walk up to Start or Root
1162 // to make sure that it did not walk in a cycle.
1163 met_dom = true; // first time meet
1164 iterations_without_region_limit = DominatorSearchLimit; // Reset
1165 }
1166 }
1167 if (sub->is_Start() || sub->is_Root()) {
1168 // Success if we met 'dom' along a path to Start or Root.
1169 // We assume there are no alternative paths that avoid 'dom'.
1170 // (This assumption is up to the caller to ensure!)
1171 return met_dom;
1172 }
1173 Node* up = sub->in(0);
1174 // Normalize simple pass-through regions and projections:
1175 up = sub->find_exact_control(up);
1176 // If sub == up, we found a self-loop. Try to push past it.
1177 if (sub == up && sub->is_Loop()) {
1178 // Take loop entry path on the way up to 'dom'.
1179 up = sub->in(1); // in(LoopNode::EntryControl);
1180 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1181 // Always take in(1) path on the way up to 'dom' for clone regions
1182 // (with only one input) or regions which merge > 2 paths
1183 // (usually used to merge fast/slow paths).
1184 up = sub->in(1);
1185 } else if (sub == up && sub->is_Region()) {
1186 // Try both paths for Regions with 2 input paths (it may be a loop head).
1187 // It could give conservative 'false' answer without information
1188 // which region's input is the entry path.
1189 iterations_without_region_limit = DominatorSearchLimit; // Reset
1190
1191 bool region_was_visited_before = false;
1192 // Was this Region node visited before?
1193 // If so, we have reached it because we accidentally took a
1194 // loop-back edge from 'sub' back into the body of the loop,
1195 // and worked our way up again to the loop header 'sub'.
1196 // So, take the first unexplored path on the way up to 'dom'.
1197 for (int j = nlist.size() - 1; j >= 0; j--) {
1198 intptr_t ni = (intptr_t)nlist.at(j);
1199 Node* visited = (Node*)(ni & ~1);
1200 bool visited_twice_already = ((ni & 1) != 0);
1201 if (visited == sub) {
1202 if (visited_twice_already) {
1203 // Visited 2 paths, but still stuck in loop body. Give up.
1204 return false;
1205 }
1206 // The Region node was visited before only once.
1207 // (We will repush with the low bit set, below.)
1208 nlist.remove(j);
1209 // We will find a new edge and re-insert.
1210 region_was_visited_before = true;
1211 break;
1212 }
1213 }
1214
1215 // Find an incoming edge which has not been seen yet; walk through it.
1216 assert(up == sub, "");
1217 uint skip = region_was_visited_before ? 1 : 0;
1218 for (uint i = 1; i < sub->req(); i++) {
1219 Node* in = sub->in(i);
1220 if (in != NULL && !in->is_top() && in != sub) {
1221 if (skip == 0) {
1222 up = in;
1223 break;
1224 }
1225 --skip; // skip this nontrivial input
1226 }
1227 }
1228
1229 // Set 0 bit to indicate that both paths were taken.
1230 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1231 }
1232
1233 if (up == sub) {
1234 break; // some kind of tight cycle
1235 }
1236 if (up == orig_sub && met_dom) {
1237 // returned back after visiting 'dom'
1238 break; // some kind of cycle
1239 }
1240 if (--iterations_without_region_limit < 0) {
1241 break; // dead cycle
1242 }
1243 sub = up;
1244 }
1245
1246 // Did not meet Root or Start node in pred. chain.
1247 // Conservative answer for dead code.
1248 return false;
1249 }
1250
1251 //------------------------------remove_dead_region-----------------------------
1252 // This control node is dead. Follow the subgraph below it making everything
1253 // using it dead as well. This will happen normally via the usual IterGVN
1254 // worklist but this call is more efficient. Do not update use-def info
1255 // inside the dead region, just at the borders.
1256 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1257 // Con's are a popular node to re-hit in the hash table again.
1258 if( dead->is_Con() ) return;
1259
1260 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1261 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1262 Node_List nstack(Thread::current()->resource_area());
1263
1264 Node *top = igvn->C->top();
1265 nstack.push(dead);
1266
1267 while (nstack.size() > 0) {
1268 dead = nstack.pop();
1269 if (dead->outcnt() > 0) {
1270 // Keep dead node on stack until all uses are processed.
1271 nstack.push(dead);
1272 // For all Users of the Dead... ;-)
1273 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1274 Node* use = dead->last_out(k);
1275 igvn->hash_delete(use); // Yank from hash table prior to mod
1276 if (use->in(0) == dead) { // Found another dead node
1277 assert (!use->is_Con(), "Control for Con node should be Root node.");
1278 use->set_req(0, top); // Cut dead edge to prevent processing
1279 nstack.push(use); // the dead node again.
1280 } else { // Else found a not-dead user
1281 for (uint j = 1; j < use->req(); j++) {
1282 if (use->in(j) == dead) { // Turn all dead inputs into TOP
1283 use->set_req(j, top);
1284 }
1285 }
1286 igvn->_worklist.push(use);
1287 }
1288 // Refresh the iterator, since any number of kills might have happened.
1289 k = dead->last_outs(kmin);
1290 }
1291 } else { // (dead->outcnt() == 0)
1292 // Done with outputs.
1293 igvn->hash_delete(dead);
1294 igvn->_worklist.remove(dead);
1295 igvn->set_type(dead, Type::TOP);
1296 if (dead->is_macro()) {
1297 igvn->C->remove_macro_node(dead);
1298 }
1299 if (dead->is_expensive()) {
1300 igvn->C->remove_expensive_node(dead);
1301 }
1302 igvn->C->record_dead_node(dead->_idx);
1303 // Kill all inputs to the dead guy
1304 for (uint i=0; i < dead->req(); i++) {
1305 Node *n = dead->in(i); // Get input to dead guy
1306 if (n != NULL && !n->is_top()) { // Input is valid?
1307 dead->set_req(i, top); // Smash input away
1308 if (n->outcnt() == 0) { // Input also goes dead?
1309 if (!n->is_Con())
1310 nstack.push(n); // Clear it out as well
1311 } else if (n->outcnt() == 1 &&
1312 n->has_special_unique_user()) {
1313 igvn->add_users_to_worklist( n );
1314 } else if (n->outcnt() <= 2 && n->is_Store()) {
1315 // Push store's uses on worklist to enable folding optimization for
1316 // store/store and store/load to the same address.
1317 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1318 // and remove_globally_dead_node().
1319 igvn->add_users_to_worklist( n );
1320 }
1321 }
1322 }
1323 } // (dead->outcnt() == 0)
1324 } // while (nstack.size() > 0) for outputs
1325 return;
1326 }
1327
1328 //------------------------------remove_dead_region-----------------------------
1329 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1330 Node *n = in(0);
1331 if( !n ) return false;
1332 // Lost control into this guy? I.e., it became unreachable?
1333 // Aggressively kill all unreachable code.
1334 if (can_reshape && n->is_top()) {
1335 kill_dead_code(this, phase->is_IterGVN());
1336 return false; // Node is dead.
1337 }
1338
1339 if( n->is_Region() && n->as_Region()->is_copy() ) {
1340 Node *m = n->nonnull_req();
1341 set_req(0, m);
1342 return true;
1343 }
1344 return false;
1345 }
1346
1347 //------------------------------Ideal_DU_postCCP-------------------------------
1348 // Idealize graph, using DU info. Must clone result into new-space
1349 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1350 return NULL; // Default to no change
1351 }
1352
1353 //------------------------------hash-------------------------------------------
1354 // Hash function over Nodes.
1355 uint Node::hash() const {
1356 uint sum = 0;
1357 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1358 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1359 return (sum>>2) + _cnt + Opcode();
1360 }
1361
1362 //------------------------------cmp--------------------------------------------
1363 // Compare special parts of simple Nodes
1364 uint Node::cmp( const Node &n ) const {
1365 return 1; // Must be same
1366 }
1367
1368 //------------------------------rematerialize-----------------------------------
1369 // Should we clone rather than spill this instruction?
1370 bool Node::rematerialize() const {
1371 if ( is_Mach() )
1372 return this->as_Mach()->rematerialize();
1373 else
1374 return (_flags & Flag_rematerialize) != 0;
1375 }
1376
1377 //------------------------------needs_anti_dependence_check---------------------
1378 // Nodes which use memory without consuming it, hence need antidependences.
1379 bool Node::needs_anti_dependence_check() const {
1380 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1381 return false;
1382 else
1383 return in(1)->bottom_type()->has_memory();
1384 }
1385
1386
1387 // Get an integer constant from a ConNode (or CastIINode).
1388 // Return a default value if there is no apparent constant here.
1389 const TypeInt* Node::find_int_type() const {
1390 if (this->is_Type()) {
1391 return this->as_Type()->type()->isa_int();
1392 } else if (this->is_Con()) {
1393 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1394 return this->bottom_type()->isa_int();
1395 }
1396 return NULL;
1397 }
1398
1399 // Get a pointer constant from a ConstNode.
1400 // Returns the constant if it is a pointer ConstNode
1401 intptr_t Node::get_ptr() const {
1402 assert( Opcode() == Op_ConP, "" );
1403 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1404 }
1405
1406 // Get a narrow oop constant from a ConNNode.
1407 intptr_t Node::get_narrowcon() const {
1408 assert( Opcode() == Op_ConN, "" );
1409 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1410 }
1411
1412 // Get a long constant from a ConNode.
1413 // Return a default value if there is no apparent constant here.
1414 const TypeLong* Node::find_long_type() const {
1415 if (this->is_Type()) {
1416 return this->as_Type()->type()->isa_long();
1417 } else if (this->is_Con()) {
1418 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1419 return this->bottom_type()->isa_long();
1420 }
1421 return NULL;
1422 }
1423
1424
1425 /**
1426 * Return a ptr type for nodes which should have it.
1427 */
1428 const TypePtr* Node::get_ptr_type() const {
1429 const TypePtr* tp = this->bottom_type()->make_ptr();
1430 #ifdef ASSERT
1431 if (tp == NULL) {
1432 this->dump(1);
1433 assert((tp != NULL), "unexpected node type");
1434 }
1435 #endif
1436 return tp;
1437 }
1438
1439 // Get a double constant from a ConstNode.
1440 // Returns the constant if it is a double ConstNode
1441 jdouble Node::getd() const {
1442 assert( Opcode() == Op_ConD, "" );
1443 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1444 }
1445
1446 // Get a float constant from a ConstNode.
1447 // Returns the constant if it is a float ConstNode
1448 jfloat Node::getf() const {
1449 assert( Opcode() == Op_ConF, "" );
1450 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1451 }
1452
1453 #ifndef PRODUCT
1454
1455 //----------------------------NotANode----------------------------------------
1456 // Used in debugging code to avoid walking across dead or uninitialized edges.
1457 static inline bool NotANode(const Node* n) {
1458 if (n == NULL) return true;
1459 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1460 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1461 return false;
1462 }
1463
1464
1465 //------------------------------find------------------------------------------
1466 // Find a neighbor of this Node with the given _idx
1467 // If idx is negative, find its absolute value, following both _in and _out.
1468 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1469 VectorSet* old_space, VectorSet* new_space ) {
1470 int node_idx = (idx >= 0) ? idx : -idx;
1471 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1472 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1473 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1474 if( v->test(n->_idx) ) return;
1475 if( (int)n->_idx == node_idx
1476 debug_only(|| n->debug_idx() == node_idx) ) {
1477 if (result != NULL)
1478 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1479 (uintptr_t)result, (uintptr_t)n, node_idx);
1480 result = n;
1481 }
1482 v->set(n->_idx);
1483 for( uint i=0; i<n->len(); i++ ) {
1484 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1485 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1486 }
1487 // Search along forward edges also:
1488 if (idx < 0 && !only_ctrl) {
1489 for( uint j=0; j<n->outcnt(); j++ ) {
1490 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1491 }
1492 }
1493 #ifdef ASSERT
1494 // Search along debug_orig edges last, checking for cycles
1495 Node* orig = n->debug_orig();
1496 if (orig != NULL) {
1497 do {
1498 if (NotANode(orig)) break;
1499 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1500 orig = orig->debug_orig();
1501 } while (orig != NULL && orig != n->debug_orig());
1502 }
1503 #endif //ASSERT
1504 }
1505
1506 // call this from debugger:
1507 Node* find_node(Node* n, int idx) {
1508 return n->find(idx);
1509 }
1510
1511 //------------------------------find-------------------------------------------
1512 Node* Node::find(int idx) const {
1513 ResourceArea *area = Thread::current()->resource_area();
1514 VectorSet old_space(area), new_space(area);
1515 Node* result = NULL;
1516 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1517 return result;
1518 }
1519
1520 //------------------------------find_ctrl--------------------------------------
1521 // Find an ancestor to this node in the control history with given _idx
1522 Node* Node::find_ctrl(int idx) const {
1523 ResourceArea *area = Thread::current()->resource_area();
1524 VectorSet old_space(area), new_space(area);
1525 Node* result = NULL;
1526 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1527 return result;
1528 }
1529 #endif
1530
1531
1532
1533 #ifndef PRODUCT
1534
1535 // -----------------------------Name-------------------------------------------
1536 extern const char *NodeClassNames[];
1537 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1538
1539 static bool is_disconnected(const Node* n) {
1540 for (uint i = 0; i < n->req(); i++) {
1541 if (n->in(i) != NULL) return false;
1542 }
1543 return true;
1544 }
1545
1546 #ifdef ASSERT
1547 static void dump_orig(Node* orig, outputStream *st) {
1548 Compile* C = Compile::current();
1549 if (NotANode(orig)) orig = NULL;
1550 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1551 if (orig == NULL) return;
1552 st->print(" !orig=");
1553 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1554 if (NotANode(fast)) fast = NULL;
1555 while (orig != NULL) {
1556 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1557 if (discon) st->print("[");
1558 if (!Compile::current()->node_arena()->contains(orig))
1559 st->print("o");
1560 st->print("%d", orig->_idx);
1561 if (discon) st->print("]");
1562 orig = orig->debug_orig();
1563 if (NotANode(orig)) orig = NULL;
1564 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1565 if (orig != NULL) st->print(",");
1566 if (fast != NULL) {
1567 // Step fast twice for each single step of orig:
1568 fast = fast->debug_orig();
1569 if (NotANode(fast)) fast = NULL;
1570 if (fast != NULL && fast != orig) {
1571 fast = fast->debug_orig();
1572 if (NotANode(fast)) fast = NULL;
1573 }
1574 if (fast == orig) {
1575 st->print("...");
1576 break;
1577 }
1578 }
1579 }
1580 }
1581
1582 void Node::set_debug_orig(Node* orig) {
1583 _debug_orig = orig;
1584 if (BreakAtNode == 0) return;
1585 if (NotANode(orig)) orig = NULL;
1586 int trip = 10;
1587 while (orig != NULL) {
1588 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1589 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1590 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1591 BREAKPOINT;
1592 }
1593 orig = orig->debug_orig();
1594 if (NotANode(orig)) orig = NULL;
1595 if (trip-- <= 0) break;
1596 }
1597 }
1598 #endif //ASSERT
1599
1600 //------------------------------dump------------------------------------------
1601 // Dump a Node
1602 void Node::dump(const char* suffix, outputStream *st) const {
1603 Compile* C = Compile::current();
1604 bool is_new = C->node_arena()->contains(this);
1605 C->_in_dump_cnt++;
1606 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1607
1608 // Dump the required and precedence inputs
1609 dump_req(st);
1610 dump_prec(st);
1611 // Dump the outputs
1612 dump_out(st);
1613
1614 if (is_disconnected(this)) {
1615 #ifdef ASSERT
1616 st->print(" [%d]",debug_idx());
1617 dump_orig(debug_orig(), st);
1618 #endif
1619 st->cr();
1620 C->_in_dump_cnt--;
1621 return; // don't process dead nodes
1622 }
1623
1624 // Dump node-specific info
1625 dump_spec(st);
1626 #ifdef ASSERT
1627 // Dump the non-reset _debug_idx
1628 if (Verbose && WizardMode) {
1629 st->print(" [%d]",debug_idx());
1630 }
1631 #endif
1632
1633 const Type *t = bottom_type();
1634
1635 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1636 const TypeInstPtr *toop = t->isa_instptr();
1637 const TypeKlassPtr *tkls = t->isa_klassptr();
1638 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1639 if (klass && klass->is_loaded() && klass->is_interface()) {
1640 st->print(" Interface:");
1641 } else if (toop) {
1642 st->print(" Oop:");
1643 } else if (tkls) {
1644 st->print(" Klass:");
1645 }
1646 t->dump_on(st);
1647 } else if (t == Type::MEMORY) {
1648 st->print(" Memory:");
1649 MemNode::dump_adr_type(this, adr_type(), st);
1650 } else if (Verbose || WizardMode) {
1651 st->print(" Type:");
1652 if (t) {
1653 t->dump_on(st);
1654 } else {
1655 st->print("no type");
1656 }
1657 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1658 // Dump MachSpillcopy vector type.
1659 t->dump_on(st);
1660 }
1661 if (is_new) {
1662 debug_only(dump_orig(debug_orig(), st));
1663 Node_Notes* nn = C->node_notes_at(_idx);
1664 if (nn != NULL && !nn->is_clear()) {
1665 if (nn->jvms() != NULL) {
1666 st->print(" !jvms:");
1667 nn->jvms()->dump_spec(st);
1668 }
1669 }
1670 }
1671 if (suffix) st->print(suffix);
1672 C->_in_dump_cnt--;
1673 }
1674
1675 //------------------------------dump_req--------------------------------------
1676 void Node::dump_req(outputStream *st) const {
1677 // Dump the required input edges
1678 for (uint i = 0; i < req(); i++) { // For all required inputs
1679 Node* d = in(i);
1680 if (d == NULL) {
1681 st->print("_ ");
1682 } else if (NotANode(d)) {
1683 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1684 } else {
1685 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1686 }
1687 }
1688 }
1689
1690
1691 //------------------------------dump_prec-------------------------------------
1692 void Node::dump_prec(outputStream *st) const {
1693 // Dump the precedence edges
1694 int any_prec = 0;
1695 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1696 Node* p = in(i);
1697 if (p != NULL) {
1698 if (!any_prec++) st->print(" |");
1699 if (NotANode(p)) { st->print("NotANode "); continue; }
1700 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1701 }
1702 }
1703 }
1704
1705 //------------------------------dump_out--------------------------------------
1706 void Node::dump_out(outputStream *st) const {
1707 // Delimit the output edges
1708 st->print(" [[");
1709 // Dump the output edges
1710 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1711 Node* u = _out[i];
1712 if (u == NULL) {
1713 st->print("_ ");
1714 } else if (NotANode(u)) {
1715 st->print("NotANode ");
1716 } else {
1717 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1718 }
1719 }
1720 st->print("]] ");
1721 }
1722
1723 //------------------------------dump_nodes-------------------------------------
1724 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1725 Node* s = (Node*)start; // remove const
1726 if (NotANode(s)) return;
1727
1728 uint depth = (uint)ABS(d);
1729 int direction = d;
1730 Compile* C = Compile::current();
1731 GrowableArray <Node *> nstack(C->unique());
1732
1733 nstack.append(s);
1734 int begin = 0;
1735 int end = 0;
1736 for(uint i = 0; i < depth; i++) {
1737 end = nstack.length();
1738 for(int j = begin; j < end; j++) {
1739 Node* tp = nstack.at(j);
1740 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1741 for(uint k = 0; k < limit; k++) {
1742 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1743
1744 if (NotANode(n)) continue;
1745 // do not recurse through top or the root (would reach unrelated stuff)
1746 if (n->is_Root() || n->is_top()) continue;
1747 if (only_ctrl && !n->is_CFG()) continue;
1748
1749 bool on_stack = nstack.contains(n);
1750 if (!on_stack) {
1751 nstack.append(n);
1752 }
1753 }
1754 }
1755 begin = end;
1756 }
1757 end = nstack.length();
1758 if (direction > 0) {
1759 for(int j = end-1; j >= 0; j--) {
1760 nstack.at(j)->dump();
1761 }
1762 } else {
1763 for(int j = 0; j < end; j++) {
1764 nstack.at(j)->dump();
1765 }
1766 }
1767 }
1768
1769 //------------------------------dump-------------------------------------------
1770 void Node::dump(int d) const {
1771 dump_nodes(this, d, false);
1772 }
1773
1774 //------------------------------dump_ctrl--------------------------------------
1775 // Dump a Node's control history to depth
1776 void Node::dump_ctrl(int d) const {
1777 dump_nodes(this, d, true);
1778 }
1779
1780 // VERIFICATION CODE
1781 // For each input edge to a node (ie - for each Use-Def edge), verify that
1782 // there is a corresponding Def-Use edge.
1783 //------------------------------verify_edges-----------------------------------
1784 void Node::verify_edges(Unique_Node_List &visited) {
1785 uint i, j, idx;
1786 int cnt;
1787 Node *n;
1788
1789 // Recursive termination test
1790 if (visited.member(this)) return;
1791 visited.push(this);
1792
1793 // Walk over all input edges, checking for correspondence
1794 for( i = 0; i < len(); i++ ) {
1795 n = in(i);
1796 if (n != NULL && !n->is_top()) {
1797 // Count instances of (Node *)this
1798 cnt = 0;
1799 for (idx = 0; idx < n->_outcnt; idx++ ) {
1800 if (n->_out[idx] == (Node *)this) cnt++;
1801 }
1802 assert( cnt > 0,"Failed to find Def-Use edge." );
1803 // Check for duplicate edges
1804 // walk the input array downcounting the input edges to n
1805 for( j = 0; j < len(); j++ ) {
1806 if( in(j) == n ) cnt--;
1807 }
1808 assert( cnt == 0,"Mismatched edge count.");
1809 } else if (n == NULL) {
1810 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1811 } else {
1812 assert(n->is_top(), "sanity");
1813 // Nothing to check.
1814 }
1815 }
1816 // Recursive walk over all input edges
1817 for( i = 0; i < len(); i++ ) {
1818 n = in(i);
1819 if( n != NULL )
1820 in(i)->verify_edges(visited);
1821 }
1822 }
1823
1824 //------------------------------verify_recur-----------------------------------
1825 static const Node *unique_top = NULL;
1826
1827 void Node::verify_recur(const Node *n, int verify_depth,
1828 VectorSet &old_space, VectorSet &new_space) {
1829 if ( verify_depth == 0 ) return;
1830 if (verify_depth > 0) --verify_depth;
1831
1832 Compile* C = Compile::current();
1833
1834 // Contained in new_space or old_space?
1835 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1836 // Check for visited in the proper space. Numberings are not unique
1837 // across spaces so we need a separate VectorSet for each space.
1838 if( v->test_set(n->_idx) ) return;
1839
1840 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1841 if (C->cached_top_node() == NULL)
1842 C->set_cached_top_node((Node*)n);
1843 assert(C->cached_top_node() == n, "TOP node must be unique");
1844 }
1845
1846 for( uint i = 0; i < n->len(); i++ ) {
1847 Node *x = n->in(i);
1848 if (!x || x->is_top()) continue;
1849
1850 // Verify my input has a def-use edge to me
1851 if (true /*VerifyDefUse*/) {
1852 // Count use-def edges from n to x
1853 int cnt = 0;
1854 for( uint j = 0; j < n->len(); j++ )
1855 if( n->in(j) == x )
1856 cnt++;
1857 // Count def-use edges from x to n
1858 uint max = x->_outcnt;
1859 for( uint k = 0; k < max; k++ )
1860 if (x->_out[k] == n)
1861 cnt--;
1862 assert( cnt == 0, "mismatched def-use edge counts" );
1863 }
1864
1865 verify_recur(x, verify_depth, old_space, new_space);
1866 }
1867
1868 }
1869
1870 //------------------------------verify-----------------------------------------
1871 // Check Def-Use info for my subgraph
1872 void Node::verify() const {
1873 Compile* C = Compile::current();
1874 Node* old_top = C->cached_top_node();
1875 ResourceMark rm;
1876 ResourceArea *area = Thread::current()->resource_area();
1877 VectorSet old_space(area), new_space(area);
1878 verify_recur(this, -1, old_space, new_space);
1879 C->set_cached_top_node(old_top);
1880 }
1881 #endif
1882
1883
1884 //------------------------------walk-------------------------------------------
1885 // Graph walk, with both pre-order and post-order functions
1886 void Node::walk(NFunc pre, NFunc post, void *env) {
1887 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1888 walk_(pre, post, env, visited);
1889 }
1890
1891 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1892 if( visited.test_set(_idx) ) return;
1893 pre(*this,env); // Call the pre-order walk function
1894 for( uint i=0; i<_max; i++ )
1895 if( in(i) ) // Input exists and is not walked?
1896 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1897 post(*this,env); // Call the post-order walk function
1898 }
1899
1900 void Node::nop(Node &, void*) {}
1901
1902 //------------------------------Registers--------------------------------------
1903 // Do we Match on this edge index or not? Generally false for Control
1904 // and true for everything else. Weird for calls & returns.
1905 uint Node::match_edge(uint idx) const {
1906 return idx; // True for other than index 0 (control)
1907 }
1908
1909 static RegMask _not_used_at_all;
1910 // Register classes are defined for specific machines
1911 const RegMask &Node::out_RegMask() const {
1912 ShouldNotCallThis();
1913 return _not_used_at_all;
1914 }
1915
1916 const RegMask &Node::in_RegMask(uint) const {
1917 ShouldNotCallThis();
1918 return _not_used_at_all;
1919 }
1920
1921 //=============================================================================
1922 //-----------------------------------------------------------------------------
1923 void Node_Array::reset( Arena *new_arena ) {
1924 _a->Afree(_nodes,_max*sizeof(Node*));
1925 _max = 0;
1926 _nodes = NULL;
1927 _a = new_arena;
1928 }
1929
1930 //------------------------------clear------------------------------------------
1931 // Clear all entries in _nodes to NULL but keep storage
1932 void Node_Array::clear() {
1933 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1934 }
1935
1936 //-----------------------------------------------------------------------------
1937 void Node_Array::grow( uint i ) {
1938 if( !_max ) {
1939 _max = 1;
1940 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1941 _nodes[0] = NULL;
1942 }
1943 uint old = _max;
1944 while( i >= _max ) _max <<= 1; // Double to fit
1945 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1946 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1947 }
1948
1949 //-----------------------------------------------------------------------------
1950 void Node_Array::insert( uint i, Node *n ) {
1951 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1952 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1953 _nodes[i] = n;
1954 }
1955
1956 //-----------------------------------------------------------------------------
1957 void Node_Array::remove( uint i ) {
1958 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1959 _nodes[_max-1] = NULL;
1960 }
1961
1962 //-----------------------------------------------------------------------------
1963 void Node_Array::sort( C_sort_func_t func) {
1964 qsort( _nodes, _max, sizeof( Node* ), func );
1965 }
1966
1967 //-----------------------------------------------------------------------------
1968 void Node_Array::dump() const {
1969 #ifndef PRODUCT
1970 for( uint i = 0; i < _max; i++ ) {
1971 Node *nn = _nodes[i];
1972 if( nn != NULL ) {
1973 tty->print("%5d--> ",i); nn->dump();
1974 }
1975 }
1976 #endif
1977 }
1978
1979 //--------------------------is_iteratively_computed------------------------------
1980 // Operation appears to be iteratively computed (such as an induction variable)
1981 // It is possible for this operation to return false for a loop-varying
1982 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
1983 bool Node::is_iteratively_computed() {
1984 if (ideal_reg()) { // does operation have a result register?
1985 for (uint i = 1; i < req(); i++) {
1986 Node* n = in(i);
1987 if (n != NULL && n->is_Phi()) {
1988 for (uint j = 1; j < n->req(); j++) {
1989 if (n->in(j) == this) {
1990 return true;
1991 }
1992 }
1993 }
1994 }
1995 }
1996 return false;
1997 }
1998
1999 //--------------------------find_similar------------------------------
2000 // Return a node with opcode "opc" and same inputs as "this" if one can
2001 // be found; Otherwise return NULL;
2002 Node* Node::find_similar(int opc) {
2003 if (req() >= 2) {
2004 Node* def = in(1);
2005 if (def && def->outcnt() >= 2) {
2006 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2007 Node* use = def->fast_out(i);
2008 if (use->Opcode() == opc &&
2009 use->req() == req()) {
2010 uint j;
2011 for (j = 0; j < use->req(); j++) {
2012 if (use->in(j) != in(j)) {
2013 break;
2014 }
2015 }
2016 if (j == use->req()) {
2017 return use;
2018 }
2019 }
2020 }
2021 }
2022 }
2023 return NULL;
2024 }
2025
2026
2027 //--------------------------unique_ctrl_out------------------------------
2028 // Return the unique control out if only one. Null if none or more than one.
2029 Node* Node::unique_ctrl_out() {
2030 Node* found = NULL;
2031 for (uint i = 0; i < outcnt(); i++) {
2032 Node* use = raw_out(i);
2033 if (use->is_CFG() && use != this) {
2034 if (found != NULL) return NULL;
2035 found = use;
2036 }
2037 }
2038 return found;
2039 }
2040
2041 //=============================================================================
2042 //------------------------------yank-------------------------------------------
2043 // Find and remove
2044 void Node_List::yank( Node *n ) {
2045 uint i;
2046 for( i = 0; i < _cnt; i++ )
2047 if( _nodes[i] == n )
2048 break;
2049
2050 if( i < _cnt )
2051 _nodes[i] = _nodes[--_cnt];
2052 }
2053
2054 //------------------------------dump-------------------------------------------
2055 void Node_List::dump() const {
2056 #ifndef PRODUCT
2057 for( uint i = 0; i < _cnt; i++ )
2058 if( _nodes[i] ) {
2059 tty->print("%5d--> ",i);
2060 _nodes[i]->dump();
2061 }
2062 #endif
2063 }
2064
2065 //=============================================================================
2066 //------------------------------remove-----------------------------------------
2067 void Unique_Node_List::remove( Node *n ) {
2068 if( _in_worklist[n->_idx] ) {
2069 for( uint i = 0; i < size(); i++ )
2070 if( _nodes[i] == n ) {
2071 map(i,Node_List::pop());
2072 _in_worklist >>= n->_idx;
2073 return;
2074 }
2075 ShouldNotReachHere();
2076 }
2077 }
2078
2079 //-----------------------remove_useless_nodes----------------------------------
2080 // Remove useless nodes from worklist
2081 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2082
2083 for( uint i = 0; i < size(); ++i ) {
2084 Node *n = at(i);
2085 assert( n != NULL, "Did not expect null entries in worklist");
2086 if( ! useful.test(n->_idx) ) {
2087 _in_worklist >>= n->_idx;
2088 map(i,Node_List::pop());
2089 // Node *replacement = Node_List::pop();
2090 // if( i != size() ) { // Check if removing last entry
2091 // _nodes[i] = replacement;
2092 // }
2093 --i; // Visit popped node
2094 // If it was last entry, loop terminates since size() was also reduced
2095 }
2096 }
2097 }
2098
2099 //=============================================================================
2100 void Node_Stack::grow() {
2101 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2102 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2103 size_t max = old_max << 1; // max * 2
2104 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2105 _inode_max = _inodes + max;
2106 _inode_top = _inodes + old_top; // restore _top
2107 }
2108
2109 // Node_Stack is used to map nodes.
2110 Node* Node_Stack::find(uint idx) const {
2111 uint sz = size();
2112 for (uint i=0; i < sz; i++) {
2113 if (idx == index_at(i) )
2114 return node_at(i);
2115 }
2116 return NULL;
2117 }
2118
2119 //=============================================================================
2120 uint TypeNode::size_of() const { return sizeof(*this); }
2121 #ifndef PRODUCT
2122 void TypeNode::dump_spec(outputStream *st) const {
2123 if( !Verbose && !WizardMode ) {
2124 // standard dump does this in Verbose and WizardMode
2125 st->print(" #"); _type->dump_on(st);
2126 }
2127 }
2128 #endif
2129 uint TypeNode::hash() const {
2130 return Node::hash() + _type->hash();
2131 }
2132 uint TypeNode::cmp( const Node &n ) const
2133 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2134 const Type *TypeNode::bottom_type() const { return _type; }
2135 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2136
2137 //------------------------------ideal_reg--------------------------------------
2138 uint TypeNode::ideal_reg() const {
2139 return _type->ideal_reg();
2140 }