1 /*
2 * Copyright (c) 1997, 2014, 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
290 // Out-of-line code from node constructors.
291 // Executed only when extra debug info. is being passed around.
292 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
293 C->set_node_notes_at(idx, nn);
294 }
295
296 // Shared initialization code.
297 inline int Node::Init(int req, Compile* C) {
298 assert(Compile::current() == C, "must use operator new(Compile*)");
299 int idx = C->next_unique();
300
301 // Allocate memory for the necessary number of edges.
302 if (req > 0) {
303 // Allocate space for _in array to have double alignment.
304 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
305 #ifdef ASSERT
306 _in[req-1] = this; // magic cookie for assertion check
307 #endif
308 }
309 // If there are default notes floating around, capture them:
310 Node_Notes* nn = C->default_node_notes();
311 if (nn != NULL) init_node_notes(C, idx, nn);
312
313 // Note: At this point, C is dead,
314 // and we begin to initialize the new Node.
315
316 _cnt = _max = req;
317 _outcnt = _outmax = 0;
318 _class_id = Class_Node;
319 _flags = 0;
320 _out = NO_OUT_ARRAY;
321 return idx;
322 }
323
324 //------------------------------Node-------------------------------------------
325 // Create a Node, with a given number of required edges.
326 Node::Node(uint req)
327 : _idx(IDX_INIT(req))
328 #ifdef ASSERT
329 , _parse_idx(_idx)
330 #endif
331 {
332 assert( req < Compile::current()->max_node_limit() - 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 #ifdef ASSERT
351 , _parse_idx(_idx)
352 #endif
353 {
354 debug_only( verify_construction() );
355 NOT_PRODUCT(nodes_created++);
356 // Assert we allocated space for input array already
357 assert( _in[0] == this, "Must pass arg count to 'new'" );
358 assert( is_not_dead(n0), "can not use dead node");
359 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
360 }
361
362 //------------------------------Node-------------------------------------------
363 Node::Node(Node *n0, Node *n1)
364 : _idx(IDX_INIT(2))
365 #ifdef ASSERT
366 , _parse_idx(_idx)
367 #endif
368 {
369 debug_only( verify_construction() );
370 NOT_PRODUCT(nodes_created++);
371 // Assert we allocated space for input array already
372 assert( _in[1] == this, "Must pass arg count to 'new'" );
373 assert( is_not_dead(n0), "can not use dead node");
374 assert( is_not_dead(n1), "can not use dead node");
375 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
376 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
377 }
378
379 //------------------------------Node-------------------------------------------
380 Node::Node(Node *n0, Node *n1, Node *n2)
381 : _idx(IDX_INIT(3))
382 #ifdef ASSERT
383 , _parse_idx(_idx)
384 #endif
385 {
386 debug_only( verify_construction() );
387 NOT_PRODUCT(nodes_created++);
388 // Assert we allocated space for input array already
389 assert( _in[2] == this, "Must pass arg count to 'new'" );
390 assert( is_not_dead(n0), "can not use dead node");
391 assert( is_not_dead(n1), "can not use dead node");
392 assert( is_not_dead(n2), "can not use dead node");
393 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
394 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
395 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
396 }
397
398 //------------------------------Node-------------------------------------------
399 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
400 : _idx(IDX_INIT(4))
401 #ifdef ASSERT
402 , _parse_idx(_idx)
403 #endif
404 {
405 debug_only( verify_construction() );
406 NOT_PRODUCT(nodes_created++);
407 // Assert we allocated space for input array already
408 assert( _in[3] == this, "Must pass arg count to 'new'" );
409 assert( is_not_dead(n0), "can not use dead node");
410 assert( is_not_dead(n1), "can not use dead node");
411 assert( is_not_dead(n2), "can not use dead node");
412 assert( is_not_dead(n3), "can not use dead node");
413 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
414 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
415 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
416 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
417 }
418
419 //------------------------------Node-------------------------------------------
420 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
421 : _idx(IDX_INIT(5))
422 #ifdef ASSERT
423 , _parse_idx(_idx)
424 #endif
425 {
426 debug_only( verify_construction() );
427 NOT_PRODUCT(nodes_created++);
428 // Assert we allocated space for input array already
429 assert( _in[4] == this, "Must pass arg count to 'new'" );
430 assert( is_not_dead(n0), "can not use dead node");
431 assert( is_not_dead(n1), "can not use dead node");
432 assert( is_not_dead(n2), "can not use dead node");
433 assert( is_not_dead(n3), "can not use dead node");
434 assert( is_not_dead(n4), "can not use dead node");
435 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
436 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
437 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
438 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
439 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
440 }
441
442 //------------------------------Node-------------------------------------------
443 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
444 Node *n4, Node *n5)
445 : _idx(IDX_INIT(6))
446 #ifdef ASSERT
447 , _parse_idx(_idx)
448 #endif
449 {
450 debug_only( verify_construction() );
451 NOT_PRODUCT(nodes_created++);
452 // Assert we allocated space for input array already
453 assert( _in[5] == this, "Must pass arg count to 'new'" );
454 assert( is_not_dead(n0), "can not use dead node");
455 assert( is_not_dead(n1), "can not use dead node");
456 assert( is_not_dead(n2), "can not use dead node");
457 assert( is_not_dead(n3), "can not use dead node");
458 assert( is_not_dead(n4), "can not use dead node");
459 assert( is_not_dead(n5), "can not use dead node");
460 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
461 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
462 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
463 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
464 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
465 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
466 }
467
468 //------------------------------Node-------------------------------------------
469 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
470 Node *n4, Node *n5, Node *n6)
471 : _idx(IDX_INIT(7))
472 #ifdef ASSERT
473 , _parse_idx(_idx)
474 #endif
475 {
476 debug_only( verify_construction() );
477 NOT_PRODUCT(nodes_created++);
478 // Assert we allocated space for input array already
479 assert( _in[6] == this, "Must pass arg count to 'new'" );
480 assert( is_not_dead(n0), "can not use dead node");
481 assert( is_not_dead(n1), "can not use dead node");
482 assert( is_not_dead(n2), "can not use dead node");
483 assert( is_not_dead(n3), "can not use dead node");
484 assert( is_not_dead(n4), "can not use dead node");
485 assert( is_not_dead(n5), "can not use dead node");
486 assert( is_not_dead(n6), "can not use dead node");
487 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
488 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
489 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
490 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
491 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
492 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
493 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
494 }
495
496
497 //------------------------------clone------------------------------------------
498 // Clone a Node.
499 Node *Node::clone() const {
500 Compile* C = Compile::current();
501 uint s = size_of(); // Size of inherited Node
502 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
503 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
504 // Set the new input pointer array
505 n->_in = (Node**)(((char*)n)+s);
506 // Cannot share the old output pointer array, so kill it
507 n->_out = NO_OUT_ARRAY;
508 // And reset the counters to 0
509 n->_outcnt = 0;
510 n->_outmax = 0;
511 // Unlock this guy, since he is not in any hash table.
512 debug_only(n->_hash_lock = 0);
513 // Walk the old node's input list to duplicate its edges
514 uint i;
515 for( i = 0; i < len(); i++ ) {
516 Node *x = in(i);
517 n->_in[i] = x;
518 if (x != NULL) x->add_out(n);
519 }
520 if (is_macro())
521 C->add_macro_node(n);
522 if (is_expensive())
523 C->add_expensive_node(n);
524
525 if (Opcode() == Op_ShenandoahWriteBarrier) {
526 C->add_shenandoah_barrier(n->as_ShenandoahBarrier());
527 }
528 // If the cloned node is a range check dependent CastII, add it to the list.
529 CastIINode* cast = n->isa_CastII();
530 if (cast != NULL && cast->has_range_check()) {
531 C->add_range_check_cast(cast);
532 }
533
534 n->set_idx(C->next_unique()); // Get new unique index as well
535 debug_only( n->verify_construction() );
536 NOT_PRODUCT(nodes_created++);
537 // Do not patch over the debug_idx of a clone, because it makes it
538 // impossible to break on the clone's moment of creation.
539 //debug_only( n->set_debug_idx( debug_idx() ) );
540
541 C->copy_node_notes_to(n, (Node*) this);
542
543 // MachNode clone
544 uint nopnds;
545 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
546 MachNode *mach = n->as_Mach();
547 MachNode *mthis = this->as_Mach();
548 // Get address of _opnd_array.
549 // It should be the same offset since it is the clone of this node.
550 MachOper **from = mthis->_opnds;
551 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
552 pointer_delta((const void*)from,
553 (const void*)(&mthis->_opnds), 1));
554 mach->_opnds = to;
555 for ( uint i = 0; i < nopnds; ++i ) {
556 to[i] = from[i]->clone(C);
557 }
558 }
559 // cloning CallNode may need to clone JVMState
560 if (n->is_Call()) {
561 n->as_Call()->clone_jvms(C);
562 }
563 if (n->is_SafePoint()) {
564 n->as_SafePoint()->clone_replaced_nodes();
565 }
566 return n; // Return the clone
567 }
568
569 //---------------------------setup_is_top--------------------------------------
570 // Call this when changing the top node, to reassert the invariants
571 // required by Node::is_top. See Compile::set_cached_top_node.
572 void Node::setup_is_top() {
573 if (this == (Node*)Compile::current()->top()) {
574 // This node has just become top. Kill its out array.
575 _outcnt = _outmax = 0;
576 _out = NULL; // marker value for top
577 assert(is_top(), "must be top");
578 } else {
579 if (_out == NULL) _out = NO_OUT_ARRAY;
580 assert(!is_top(), "must not be top");
581 }
582 }
583
584
585 //------------------------------~Node------------------------------------------
586 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
587 extern int reclaim_idx ;
588 extern int reclaim_in ;
589 extern int reclaim_node;
590 void Node::destruct() {
591 // Eagerly reclaim unique Node numberings
592 Compile* compile = Compile::current();
593 if ((uint)_idx+1 == compile->unique()) {
594 compile->set_unique(compile->unique()-1);
595 #ifdef ASSERT
596 reclaim_idx++;
597 #endif
598 }
599 // Clear debug info:
600 Node_Notes* nn = compile->node_notes_at(_idx);
601 if (nn != NULL) nn->clear();
602 // Walk the input array, freeing the corresponding output edges
603 _cnt = _max; // forget req/prec distinction
604 uint i;
605 for( i = 0; i < _max; i++ ) {
606 set_req(i, NULL);
607 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
608 }
609 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
610 // See if the input array was allocated just prior to the object
611 int edge_size = _max*sizeof(void*);
612 int out_edge_size = _outmax*sizeof(void*);
613 char *edge_end = ((char*)_in) + edge_size;
614 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
615 char *out_edge_end = out_array + out_edge_size;
616 int node_size = size_of();
617
618 // Free the output edge array
619 if (out_edge_size > 0) {
620 #ifdef ASSERT
621 if( out_edge_end == compile->node_arena()->hwm() )
622 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
623 #endif
624 compile->node_arena()->Afree(out_array, out_edge_size);
625 }
626
627 // Free the input edge array and the node itself
628 if( edge_end == (char*)this ) {
629 #ifdef ASSERT
630 if( edge_end+node_size == compile->node_arena()->hwm() ) {
631 reclaim_in += edge_size;
632 reclaim_node+= node_size;
633 }
634 #else
635 // It was; free the input array and object all in one hit
636 compile->node_arena()->Afree(_in,edge_size+node_size);
637 #endif
638 } else {
639
640 // Free just the input array
641 #ifdef ASSERT
642 if( edge_end == compile->node_arena()->hwm() )
643 reclaim_in += edge_size;
644 #endif
645 compile->node_arena()->Afree(_in,edge_size);
646
647 // Free just the object
648 #ifdef ASSERT
649 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
650 reclaim_node+= node_size;
651 #else
652 compile->node_arena()->Afree(this,node_size);
653 #endif
654 }
655 if (is_macro()) {
656 compile->remove_macro_node(this);
657 }
658 if (is_expensive()) {
659 compile->remove_expensive_node(this);
660 }
661 if (is_ShenandoahBarrier()) {
662 compile->remove_shenandoah_barrier(this->as_ShenandoahBarrier());
663 }
664 CastIINode* cast = isa_CastII();
665 if (cast != NULL && cast->has_range_check()) {
666 compile->remove_range_check_cast(cast);
667 }
668
669 if (is_SafePoint()) {
670 as_SafePoint()->delete_replaced_nodes();
671 }
672 #ifdef ASSERT
673 // We will not actually delete the storage, but we'll make the node unusable.
674 *(address*)this = badAddress; // smash the C++ vtbl, probably
675 _in = _out = (Node**) badAddress;
676 _max = _cnt = _outmax = _outcnt = 0;
677 #endif
678 }
679
680 //------------------------------grow-------------------------------------------
681 // Grow the input array, making space for more edges
682 void Node::grow( uint len ) {
683 Arena* arena = Compile::current()->node_arena();
684 uint new_max = _max;
685 if( new_max == 0 ) {
686 _max = 4;
687 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
688 Node** to = _in;
689 to[0] = NULL;
690 to[1] = NULL;
691 to[2] = NULL;
692 to[3] = NULL;
693 return;
694 }
695 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
696 // Trimming to limit allows a uint8 to handle up to 255 edges.
697 // Previously I was using only powers-of-2 which peaked at 128 edges.
698 //if( new_max >= limit ) new_max = limit-1;
699 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
700 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
701 _max = new_max; // Record new max length
702 // This assertion makes sure that Node::_max is wide enough to
703 // represent the numerical value of new_max.
704 assert(_max == new_max && _max > len, "int width of _max is too small");
705 }
706
707 //-----------------------------out_grow----------------------------------------
708 // Grow the input array, making space for more edges
709 void Node::out_grow( uint len ) {
710 assert(!is_top(), "cannot grow a top node's out array");
711 Arena* arena = Compile::current()->node_arena();
712 uint new_max = _outmax;
713 if( new_max == 0 ) {
714 _outmax = 4;
715 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
716 return;
717 }
718 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
719 // Trimming to limit allows a uint8 to handle up to 255 edges.
720 // Previously I was using only powers-of-2 which peaked at 128 edges.
721 //if( new_max >= limit ) new_max = limit-1;
722 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
723 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
724 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
725 _outmax = new_max; // Record new max length
726 // This assertion makes sure that Node::_max is wide enough to
727 // represent the numerical value of new_max.
728 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
729 }
730
731 #ifdef ASSERT
732 //------------------------------is_dead----------------------------------------
733 bool Node::is_dead() const {
734 // Mach and pinch point nodes may look like dead.
735 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
736 return false;
737 for( uint i = 0; i < _max; i++ )
738 if( _in[i] != NULL )
739 return false;
740 dump();
741 return true;
742 }
743 #endif
744
745
746 //------------------------------is_unreachable---------------------------------
747 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
748 assert(!is_Mach(), "doesn't work with MachNodes");
749 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
750 }
751
752 //------------------------------add_req----------------------------------------
753 // Add a new required input at the end
754 void Node::add_req( Node *n ) {
755 assert( is_not_dead(n), "can not use dead node");
756
757 // Look to see if I can move precedence down one without reallocating
758 if( (_cnt >= _max) || (in(_max-1) != NULL) )
759 grow( _max+1 );
760
761 // Find a precedence edge to move
762 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
763 uint i;
764 for( i=_cnt; i<_max; i++ )
765 if( in(i) == NULL ) // Find the NULL at end of prec edge list
766 break; // There must be one, since we grew the array
767 _in[i] = in(_cnt); // Move prec over, making space for req edge
768 }
769 _in[_cnt++] = n; // Stuff over old prec edge
770 if (n != NULL) n->add_out((Node *)this);
771 }
772
773 //---------------------------add_req_batch-------------------------------------
774 // Add a new required input at the end
775 void Node::add_req_batch( Node *n, uint m ) {
776 assert( is_not_dead(n), "can not use dead node");
777 // check various edge cases
778 if ((int)m <= 1) {
779 assert((int)m >= 0, "oob");
780 if (m != 0) add_req(n);
781 return;
782 }
783
784 // Look to see if I can move precedence down one without reallocating
785 if( (_cnt+m) > _max || _in[_max-m] )
786 grow( _max+m );
787
788 // Find a precedence edge to move
789 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
790 uint i;
791 for( i=_cnt; i<_max; i++ )
792 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
793 break; // There must be one, since we grew the array
794 // Slide all the precs over by m positions (assume #prec << m).
795 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
796 }
797
798 // Stuff over the old prec edges
799 for(uint i=0; i<m; i++ ) {
800 _in[_cnt++] = n;
801 }
802
803 // Insert multiple out edges on the node.
804 if (n != NULL && !n->is_top()) {
805 for(uint i=0; i<m; i++ ) {
806 n->add_out((Node *)this);
807 }
808 }
809 }
810
811 //------------------------------del_req----------------------------------------
812 // Delete the required edge and compact the edge array
813 void Node::del_req( uint idx ) {
814 assert( idx < _cnt, "oob");
815 assert( !VerifyHashTableKeys || _hash_lock == 0,
816 "remove node from hash table before modifying it");
817 // First remove corresponding def-use edge
818 Node *n = in(idx);
819 if (n != NULL) n->del_out((Node *)this);
820 _in[idx] = in(--_cnt); // Compact the array
821 _in[_cnt] = NULL; // NULL out emptied slot
822 }
823
824 //------------------------------del_req_ordered--------------------------------
825 // Delete the required edge and compact the edge array with preserved order
826 void Node::del_req_ordered( uint idx ) {
827 assert( idx < _cnt, "oob");
828 assert( !VerifyHashTableKeys || _hash_lock == 0,
829 "remove node from hash table before modifying it");
830 // First remove corresponding def-use edge
831 Node *n = in(idx);
832 if (n != NULL) n->del_out((Node *)this);
833 if (idx < _cnt - 1) { // Not last edge ?
834 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
835 }
836 _in[--_cnt] = NULL; // NULL out emptied slot
837 }
838
839 //------------------------------ins_req----------------------------------------
840 // Insert a new required input at the end
841 void Node::ins_req( uint idx, Node *n ) {
842 assert( is_not_dead(n), "can not use dead node");
843 add_req(NULL); // Make space
844 assert( idx < _max, "Must have allocated enough space");
845 // Slide over
846 if(_cnt-idx-1 > 0) {
847 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
848 }
849 _in[idx] = n; // Stuff over old required edge
850 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
851 }
852
853 //-----------------------------find_edge---------------------------------------
854 int Node::find_edge(Node* n) {
855 for (uint i = 0; i < len(); i++) {
856 if (_in[i] == n) return i;
857 }
858 return -1;
859 }
860
861 //----------------------------replace_edge-------------------------------------
862 int Node::replace_edge(Node* old, Node* neww) {
863 if (old == neww) return 0; // nothing to do
864 uint nrep = 0;
865 for (uint i = 0; i < len(); i++) {
866 if (in(i) == old) {
867 if (i < req())
868 set_req(i, neww);
869 else
870 set_prec(i, neww);
871 nrep++;
872 }
873 }
874 return nrep;
875 }
876
877 /**
878 * Replace input edges in the range pointing to 'old' node.
879 */
880 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
881 if (old == neww) return 0; // nothing to do
882 uint nrep = 0;
883 for (int i = start; i < end; i++) {
884 if (in(i) == old) {
885 set_req(i, neww);
886 nrep++;
887 }
888 }
889 return nrep;
890 }
891
892 //-------------------------disconnect_inputs-----------------------------------
893 // NULL out all inputs to eliminate incoming Def-Use edges.
894 // Return the number of edges between 'n' and 'this'
895 int Node::disconnect_inputs(Node *n, Compile* C) {
896 int edges_to_n = 0;
897
898 uint cnt = req();
899 for( uint i = 0; i < cnt; ++i ) {
900 if( in(i) == 0 ) continue;
901 if( in(i) == n ) ++edges_to_n;
902 set_req(i, NULL);
903 }
904 // Remove precedence edges if any exist
905 // Note: Safepoints may have precedence edges, even during parsing
906 if( (req() != len()) && (in(req()) != NULL) ) {
907 uint max = len();
908 for( uint i = 0; i < max; ++i ) {
909 if( in(i) == 0 ) continue;
910 if( in(i) == n ) ++edges_to_n;
911 set_prec(i, NULL);
912 }
913 }
914
915 // Node::destruct requires all out edges be deleted first
916 // debug_only(destruct();) // no reuse benefit expected
917 if (edges_to_n == 0) {
918 C->record_dead_node(_idx);
919 }
920 return edges_to_n;
921 }
922
923 //-----------------------------uncast---------------------------------------
924 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
925 // Strip away casting. (It is depth-limited.)
926 Node* Node::uncast() const {
927 // Should be inline:
928 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
929 if (is_ConstraintCast() || is_CheckCastPP())
930 return uncast_helper(this);
931 else
932 return (Node*) this;
933 }
934
935 //---------------------------uncast_helper-------------------------------------
936 Node* Node::uncast_helper(const Node* p) {
937 #ifdef ASSERT
938 uint depth_count = 0;
939 const Node* orig_p = p;
940 #endif
941
942 while (true) {
943 #ifdef ASSERT
944 if (depth_count >= K) {
945 orig_p->dump(4);
946 if (p != orig_p)
947 p->dump(1);
948 }
949 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
950 #endif
951 if (p == NULL || p->req() != 2) {
952 break;
953 } else if (p->is_ConstraintCast()) {
954 p = p->in(1);
955 } else if (p->is_CheckCastPP()) {
956 p = p->in(1);
957 } else {
958 break;
959 }
960 }
961 return (Node*) p;
962 }
963
964 // Find out of current node that matches opcode.
965 Node* Node::find_out_with(int opcode) {
966 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
967 Node* use = fast_out(i);
968 if (use->Opcode() == opcode) {
969 return use;
970 }
971 }
972 return NULL;
973 }
974
975 // Return true if the current node has an out that matches opcode.
976 bool Node::has_out_with(int opcode) {
977 return (find_out_with(opcode) != NULL);
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 ) i++;
993 _in[i] = n; // Stuff prec edge over NULL
994 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
995 }
996
997 //------------------------------rm_prec----------------------------------------
998 // Remove a precedence input. Precedence inputs are unordered, with
999 // duplicates removed and NULLs packed down at the end.
1000 void Node::rm_prec( uint j ) {
1001
1002 // Find end of precedence list to pack NULLs
1003 uint i;
1004 for( i=j; i<_max; i++ )
1005 if( !_in[i] ) // Find the NULL at end of prec edge list
1006 break;
1007 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
1008 _in[j] = _in[--i]; // Move last element over removed guy
1009 _in[i] = NULL; // NULL out last element
1010 }
1011
1012 //------------------------------size_of----------------------------------------
1013 uint Node::size_of() const { return sizeof(*this); }
1014
1015 //------------------------------ideal_reg--------------------------------------
1016 uint Node::ideal_reg() const { return 0; }
1017
1018 //------------------------------jvms-------------------------------------------
1019 JVMState* Node::jvms() const { return NULL; }
1020
1021 #ifdef ASSERT
1022 //------------------------------jvms-------------------------------------------
1023 bool Node::verify_jvms(const JVMState* using_jvms) const {
1024 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1025 if (jvms == using_jvms) return true;
1026 }
1027 return false;
1028 }
1029
1030 //------------------------------init_NodeProperty------------------------------
1031 void Node::init_NodeProperty() {
1032 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1033 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1034 }
1035 #endif
1036
1037 //------------------------------format-----------------------------------------
1038 // Print as assembly
1039 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1040 //------------------------------emit-------------------------------------------
1041 // Emit bytes starting at parameter 'ptr'.
1042 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1043 //------------------------------size-------------------------------------------
1044 // Size of instruction in bytes
1045 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1046
1047 //------------------------------CFG Construction-------------------------------
1048 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1049 // Goto and Return.
1050 const Node *Node::is_block_proj() const { return 0; }
1051
1052 // Minimum guaranteed type
1053 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1054
1055
1056 //------------------------------raise_bottom_type------------------------------
1057 // Get the worst-case Type output for this Node.
1058 void Node::raise_bottom_type(const Type* new_type) {
1059 if (is_Type()) {
1060 TypeNode *n = this->as_Type();
1061 if (VerifyAliases) {
1062 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1063 }
1064 n->set_type(new_type);
1065 } else if (is_Load()) {
1066 LoadNode *n = this->as_Load();
1067 if (VerifyAliases) {
1068 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1069 }
1070 n->set_type(new_type);
1071 }
1072 }
1073
1074 //------------------------------Identity---------------------------------------
1075 // Return a node that the given node is equivalent to.
1076 Node *Node::Identity( PhaseTransform * ) {
1077 return this; // Default to no identities
1078 }
1079
1080 //------------------------------Value------------------------------------------
1081 // Compute a new Type for a node using the Type of the inputs.
1082 const Type *Node::Value( PhaseTransform * ) const {
1083 return bottom_type(); // Default to worst-case Type
1084 }
1085
1086 //------------------------------Ideal------------------------------------------
1087 //
1088 // 'Idealize' the graph rooted at this Node.
1089 //
1090 // In order to be efficient and flexible there are some subtle invariants
1091 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1092 // these invariants, although its too slow to have on by default. If you are
1093 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1094 //
1095 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1096 // pointer. If ANY change is made, it must return the root of the reshaped
1097 // graph - even if the root is the same Node. Example: swapping the inputs
1098 // to an AddINode gives the same answer and same root, but you still have to
1099 // return the 'this' pointer instead of NULL.
1100 //
1101 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1102 // Identity call to return an old Node; basically if Identity can find
1103 // another Node have the Ideal call make no change and return NULL.
1104 // Example: AddINode::Ideal must check for add of zero; in this case it
1105 // returns NULL instead of doing any graph reshaping.
1106 //
1107 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1108 // sharing there may be other users of the old Nodes relying on their current
1109 // semantics. Modifying them will break the other users.
1110 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1111 // "X+3" unchanged in case it is shared.
1112 //
1113 // If you modify the 'this' pointer's inputs, you should use
1114 // 'set_req'. If you are making a new Node (either as the new root or
1115 // some new internal piece) you may use 'init_req' to set the initial
1116 // value. You can make a new Node with either 'new' or 'clone'. In
1117 // either case, def-use info is correctly maintained.
1118 //
1119 // Example: reshape "(X+3)+4" into "X+7":
1120 // set_req(1, in(1)->in(1));
1121 // set_req(2, phase->intcon(7));
1122 // return this;
1123 // Example: reshape "X*4" into "X<<2"
1124 // return new (C) LShiftINode(in(1), phase->intcon(2));
1125 //
1126 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1127 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1128 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1129 // return new (C) AddINode(shift, in(1));
1130 //
1131 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1132 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1133 // The Right Thing with def-use info.
1134 //
1135 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1136 // graph uses the 'this' Node it must be the root. If you want a Node with
1137 // the same Opcode as the 'this' pointer use 'clone'.
1138 //
1139 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1140 return NULL; // Default to being Ideal already
1141 }
1142
1143 // Some nodes have specific Ideal subgraph transformations only if they are
1144 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1145 // for the transformations to happen.
1146 bool Node::has_special_unique_user() const {
1147 assert(outcnt() == 1, "match only for unique out");
1148 Node* n = unique_out();
1149 int op = Opcode();
1150 if( this->is_Store() ) {
1151 // Condition for back-to-back stores folding.
1152 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1153 } else if (this->is_Load()) {
1154 // Condition for removing an unused LoadNode from the MemBarAcquire precedence input
1155 return n->Opcode() == Op_MemBarAcquire;
1156 } else if( op == Op_AddL ) {
1157 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1158 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1159 } else if( op == Op_SubI || op == Op_SubL ) {
1160 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1161 return n->Opcode() == op && n->in(2) == this;
1162 } else if (op == Op_ShenandoahWriteBarrier) {
1163 return n->Opcode() == Op_ShenandoahWBMemProj;
1164 }
1165 return false;
1166 };
1167
1168 //--------------------------find_exact_control---------------------------------
1169 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1170 Node* Node::find_exact_control(Node* ctrl) {
1171 if (ctrl == NULL && this->is_Region())
1172 ctrl = this->as_Region()->is_copy();
1173
1174 if (ctrl != NULL && ctrl->is_CatchProj()) {
1175 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1176 ctrl = ctrl->in(0);
1177 if (ctrl != NULL && !ctrl->is_top())
1178 ctrl = ctrl->in(0);
1179 }
1180
1181 if (ctrl != NULL && ctrl->is_Proj())
1182 ctrl = ctrl->in(0);
1183
1184 return ctrl;
1185 }
1186
1187 //--------------------------dominates------------------------------------------
1188 // Helper function for MemNode::all_controls_dominate().
1189 // Check if 'this' control node dominates or equal to 'sub' control node.
1190 // We already know that if any path back to Root or Start reaches 'this',
1191 // then all paths so, so this is a simple search for one example,
1192 // not an exhaustive search for a counterexample.
1193 bool Node::dominates(Node* sub, Node_List &nlist) {
1194 assert(this->is_CFG(), "expecting control");
1195 assert(sub != NULL && sub->is_CFG(), "expecting control");
1196
1197 // detect dead cycle without regions
1198 int iterations_without_region_limit = DominatorSearchLimit;
1199
1200 Node* orig_sub = sub;
1201 Node* dom = this;
1202 bool met_dom = false;
1203 nlist.clear();
1204
1205 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1206 // After seeing 'dom', continue up to Root or Start.
1207 // If we hit a region (backward split point), it may be a loop head.
1208 // Keep going through one of the region's inputs. If we reach the
1209 // same region again, go through a different input. Eventually we
1210 // will either exit through the loop head, or give up.
1211 // (If we get confused, break out and return a conservative 'false'.)
1212 while (sub != NULL) {
1213 if (sub->is_top()) break; // Conservative answer for dead code.
1214 if (sub == dom) {
1215 if (nlist.size() == 0) {
1216 // No Region nodes except loops were visited before and the EntryControl
1217 // path was taken for loops: it did not walk in a cycle.
1218 return true;
1219 } else if (met_dom) {
1220 break; // already met before: walk in a cycle
1221 } else {
1222 // Region nodes were visited. Continue walk up to Start or Root
1223 // to make sure that it did not walk in a cycle.
1224 met_dom = true; // first time meet
1225 iterations_without_region_limit = DominatorSearchLimit; // Reset
1226 }
1227 }
1228 if (sub->is_Start() || sub->is_Root()) {
1229 // Success if we met 'dom' along a path to Start or Root.
1230 // We assume there are no alternative paths that avoid 'dom'.
1231 // (This assumption is up to the caller to ensure!)
1232 return met_dom;
1233 }
1234 Node* up = sub->in(0);
1235 // Normalize simple pass-through regions and projections:
1236 up = sub->find_exact_control(up);
1237 // If sub == up, we found a self-loop. Try to push past it.
1238 if (sub == up && sub->is_Loop()) {
1239 // Take loop entry path on the way up to 'dom'.
1240 up = sub->in(1); // in(LoopNode::EntryControl);
1241 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1242 // Always take in(1) path on the way up to 'dom' for clone regions
1243 // (with only one input) or regions which merge > 2 paths
1244 // (usually used to merge fast/slow paths).
1245 up = sub->in(1);
1246 } else if (sub == up && sub->is_Region()) {
1247 // Try both paths for Regions with 2 input paths (it may be a loop head).
1248 // It could give conservative 'false' answer without information
1249 // which region's input is the entry path.
1250 iterations_without_region_limit = DominatorSearchLimit; // Reset
1251
1252 bool region_was_visited_before = false;
1253 // Was this Region node visited before?
1254 // If so, we have reached it because we accidentally took a
1255 // loop-back edge from 'sub' back into the body of the loop,
1256 // and worked our way up again to the loop header 'sub'.
1257 // So, take the first unexplored path on the way up to 'dom'.
1258 for (int j = nlist.size() - 1; j >= 0; j--) {
1259 intptr_t ni = (intptr_t)nlist.at(j);
1260 Node* visited = (Node*)(ni & ~1);
1261 bool visited_twice_already = ((ni & 1) != 0);
1262 if (visited == sub) {
1263 if (visited_twice_already) {
1264 // Visited 2 paths, but still stuck in loop body. Give up.
1265 return false;
1266 }
1267 // The Region node was visited before only once.
1268 // (We will repush with the low bit set, below.)
1269 nlist.remove(j);
1270 // We will find a new edge and re-insert.
1271 region_was_visited_before = true;
1272 break;
1273 }
1274 }
1275
1276 // Find an incoming edge which has not been seen yet; walk through it.
1277 assert(up == sub, "");
1278 uint skip = region_was_visited_before ? 1 : 0;
1279 for (uint i = 1; i < sub->req(); i++) {
1280 Node* in = sub->in(i);
1281 if (in != NULL && !in->is_top() && in != sub) {
1282 if (skip == 0) {
1283 up = in;
1284 break;
1285 }
1286 --skip; // skip this nontrivial input
1287 }
1288 }
1289
1290 // Set 0 bit to indicate that both paths were taken.
1291 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1292 }
1293
1294 if (up == sub) {
1295 break; // some kind of tight cycle
1296 }
1297 if (up == orig_sub && met_dom) {
1298 // returned back after visiting 'dom'
1299 break; // some kind of cycle
1300 }
1301 if (--iterations_without_region_limit < 0) {
1302 break; // dead cycle
1303 }
1304 sub = up;
1305 }
1306
1307 // Did not meet Root or Start node in pred. chain.
1308 // Conservative answer for dead code.
1309 return false;
1310 }
1311
1312 //------------------------------remove_dead_region-----------------------------
1313 // This control node is dead. Follow the subgraph below it making everything
1314 // using it dead as well. This will happen normally via the usual IterGVN
1315 // worklist but this call is more efficient. Do not update use-def info
1316 // inside the dead region, just at the borders.
1317 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1318 // Con's are a popular node to re-hit in the hash table again.
1319 if( dead->is_Con() ) return;
1320
1321 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1322 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1323 Node_List nstack(Thread::current()->resource_area());
1324
1325 Node *top = igvn->C->top();
1326 nstack.push(dead);
1327 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1328
1329 while (nstack.size() > 0) {
1330 dead = nstack.pop();
1331 if (dead->outcnt() > 0) {
1332 // Keep dead node on stack until all uses are processed.
1333 nstack.push(dead);
1334 // For all Users of the Dead... ;-)
1335 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1336 Node* use = dead->last_out(k);
1337 igvn->hash_delete(use); // Yank from hash table prior to mod
1338 if (use->in(0) == dead) { // Found another dead node
1339 assert (!use->is_Con(), "Control for Con node should be Root node.");
1340 use->set_req(0, top); // Cut dead edge to prevent processing
1341 nstack.push(use); // the dead node again.
1342 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1343 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1344 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1345 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1346 use->set_req(0, top); // Cut self edge
1347 nstack.push(use);
1348 } else { // Else found a not-dead user
1349 // Dead if all inputs are top or null
1350 bool dead_use = !use->is_Root(); // Keep empty graph alive
1351 for (uint j = 1; j < use->req(); j++) {
1352 Node* in = use->in(j);
1353 if (in == dead) { // Turn all dead inputs into TOP
1354 use->set_req(j, top);
1355 } else if (in != NULL && !in->is_top()) {
1356 dead_use = false;
1357 }
1358 }
1359 if (dead_use) {
1360 if (use->is_Region()) {
1361 use->set_req(0, top); // Cut self edge
1362 }
1363 nstack.push(use);
1364 } else {
1365 igvn->_worklist.push(use);
1366 }
1367 }
1368 // Refresh the iterator, since any number of kills might have happened.
1369 k = dead->last_outs(kmin);
1370 }
1371 } else { // (dead->outcnt() == 0)
1372 // Done with outputs.
1373 igvn->hash_delete(dead);
1374 igvn->_worklist.remove(dead);
1375 igvn->set_type(dead, Type::TOP);
1376 if (dead->is_macro()) {
1377 igvn->C->remove_macro_node(dead);
1378 }
1379 if (dead->is_expensive()) {
1380 igvn->C->remove_expensive_node(dead);
1381 }
1382 if (dead->is_ShenandoahBarrier()) {
1383 igvn->C->remove_shenandoah_barrier(dead->as_ShenandoahBarrier());
1384 }
1385 CastIINode* cast = dead->isa_CastII();
1386 if (cast != NULL && cast->has_range_check()) {
1387 igvn->C->remove_range_check_cast(cast);
1388 }
1389 igvn->C->record_dead_node(dead->_idx);
1390 // Kill all inputs to the dead guy
1391 for (uint i=0; i < dead->req(); i++) {
1392 Node *n = dead->in(i); // Get input to dead guy
1393 if (n != NULL && !n->is_top()) { // Input is valid?
1394 dead->set_req(i, top); // Smash input away
1395 if (n->outcnt() == 0) { // Input also goes dead?
1396 if (!n->is_Con())
1397 nstack.push(n); // Clear it out as well
1398 } else if (n->outcnt() == 1 &&
1399 n->has_special_unique_user()) {
1400 igvn->add_users_to_worklist( n );
1401 } else if (n->outcnt() <= 2 && n->is_Store()) {
1402 // Push store's uses on worklist to enable folding optimization for
1403 // store/store and store/load to the same address.
1404 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1405 // and remove_globally_dead_node().
1406 igvn->add_users_to_worklist( n );
1407 } else if (n->Opcode() == Op_AddP && CallLeafNode::has_only_g1_wb_pre_uses(n)) {
1408 igvn->add_users_to_worklist(n);
1409 }
1410 }
1411 }
1412 } // (dead->outcnt() == 0)
1413 } // while (nstack.size() > 0) for outputs
1414 return;
1415 }
1416
1417 //------------------------------remove_dead_region-----------------------------
1418 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1419 Node *n = in(0);
1420 if( !n ) return false;
1421 // Lost control into this guy? I.e., it became unreachable?
1422 // Aggressively kill all unreachable code.
1423 if (can_reshape && n->is_top()) {
1424 kill_dead_code(this, phase->is_IterGVN());
1425 return false; // Node is dead.
1426 }
1427
1428 if( n->is_Region() && n->as_Region()->is_copy() ) {
1429 Node *m = n->nonnull_req();
1430 set_req(0, m);
1431 return true;
1432 }
1433 return false;
1434 }
1435
1436 //------------------------------hash-------------------------------------------
1437 // Hash function over Nodes.
1438 uint Node::hash() const {
1439 uint sum = 0;
1440 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1441 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1442 return (sum>>2) + _cnt + Opcode();
1443 }
1444
1445 //------------------------------cmp--------------------------------------------
1446 // Compare special parts of simple Nodes
1447 uint Node::cmp( const Node &n ) const {
1448 return 1; // Must be same
1449 }
1450
1451 //------------------------------rematerialize-----------------------------------
1452 // Should we clone rather than spill this instruction?
1453 bool Node::rematerialize() const {
1454 if ( is_Mach() )
1455 return this->as_Mach()->rematerialize();
1456 else
1457 return (_flags & Flag_rematerialize) != 0;
1458 }
1459
1460 //------------------------------needs_anti_dependence_check---------------------
1461 // Nodes which use memory without consuming it, hence need antidependences.
1462 bool Node::needs_anti_dependence_check() const {
1463 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1464 return false;
1465 else
1466 return in(1)->bottom_type()->has_memory();
1467 }
1468
1469
1470 // Get an integer constant from a ConNode (or CastIINode).
1471 // Return a default value if there is no apparent constant here.
1472 const TypeInt* Node::find_int_type() const {
1473 if (this->is_Type()) {
1474 return this->as_Type()->type()->isa_int();
1475 } else if (this->is_Con()) {
1476 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1477 return this->bottom_type()->isa_int();
1478 }
1479 return NULL;
1480 }
1481
1482 // Get a pointer constant from a ConstNode.
1483 // Returns the constant if it is a pointer ConstNode
1484 intptr_t Node::get_ptr() const {
1485 assert( Opcode() == Op_ConP, "" );
1486 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1487 }
1488
1489 // Get a narrow oop constant from a ConNNode.
1490 intptr_t Node::get_narrowcon() const {
1491 assert( Opcode() == Op_ConN, "" );
1492 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1493 }
1494
1495 // Get a long constant from a ConNode.
1496 // Return a default value if there is no apparent constant here.
1497 const TypeLong* Node::find_long_type() const {
1498 if (this->is_Type()) {
1499 return this->as_Type()->type()->isa_long();
1500 } else if (this->is_Con()) {
1501 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1502 return this->bottom_type()->isa_long();
1503 }
1504 return NULL;
1505 }
1506
1507
1508 /**
1509 * Return a ptr type for nodes which should have it.
1510 */
1511 const TypePtr* Node::get_ptr_type() const {
1512 const TypePtr* tp = this->bottom_type()->make_ptr();
1513 #ifdef ASSERT
1514 if (tp == NULL) {
1515 this->dump(1);
1516 assert((tp != NULL), "unexpected node type");
1517 }
1518 #endif
1519 return tp;
1520 }
1521
1522 // Get a double constant from a ConstNode.
1523 // Returns the constant if it is a double ConstNode
1524 jdouble Node::getd() const {
1525 assert( Opcode() == Op_ConD, "" );
1526 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1527 }
1528
1529 // Get a float constant from a ConstNode.
1530 // Returns the constant if it is a float ConstNode
1531 jfloat Node::getf() const {
1532 assert( Opcode() == Op_ConF, "" );
1533 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1534 }
1535
1536 #ifndef PRODUCT
1537
1538 //----------------------------NotANode----------------------------------------
1539 // Used in debugging code to avoid walking across dead or uninitialized edges.
1540 static inline bool NotANode(const Node* n) {
1541 if (n == NULL) return true;
1542 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1543 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1544 return false;
1545 }
1546
1547
1548 //------------------------------find------------------------------------------
1549 // Find a neighbor of this Node with the given _idx
1550 // If idx is negative, find its absolute value, following both _in and _out.
1551 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1552 VectorSet* old_space, VectorSet* new_space ) {
1553 int node_idx = (idx >= 0) ? idx : -idx;
1554 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1555 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1556 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1557 if( v->test(n->_idx) ) return;
1558 if( (int)n->_idx == node_idx
1559 debug_only(|| n->debug_idx() == node_idx) ) {
1560 if (result != NULL)
1561 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1562 (uintptr_t)result, (uintptr_t)n, node_idx);
1563 result = n;
1564 }
1565 v->set(n->_idx);
1566 for( uint i=0; i<n->len(); i++ ) {
1567 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1568 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1569 }
1570 // Search along forward edges also:
1571 if (idx < 0 && !only_ctrl) {
1572 for( uint j=0; j<n->outcnt(); j++ ) {
1573 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1574 }
1575 }
1576 #ifdef ASSERT
1577 // Search along debug_orig edges last, checking for cycles
1578 Node* orig = n->debug_orig();
1579 if (orig != NULL) {
1580 do {
1581 if (NotANode(orig)) break;
1582 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1583 orig = orig->debug_orig();
1584 } while (orig != NULL && orig != n->debug_orig());
1585 }
1586 #endif //ASSERT
1587 }
1588
1589 // call this from debugger:
1590 Node* find_node(Node* n, int idx) {
1591 return n->find(idx);
1592 }
1593
1594 //------------------------------find-------------------------------------------
1595 Node* Node::find(int idx) const {
1596 ResourceArea *area = Thread::current()->resource_area();
1597 VectorSet old_space(area), new_space(area);
1598 Node* result = NULL;
1599 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1600 return result;
1601 }
1602
1603 //------------------------------find_ctrl--------------------------------------
1604 // Find an ancestor to this node in the control history with given _idx
1605 Node* Node::find_ctrl(int idx) const {
1606 ResourceArea *area = Thread::current()->resource_area();
1607 VectorSet old_space(area), new_space(area);
1608 Node* result = NULL;
1609 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1610 return result;
1611 }
1612 #endif
1613
1614
1615
1616 #ifndef PRODUCT
1617
1618 // -----------------------------Name-------------------------------------------
1619 extern const char *NodeClassNames[];
1620 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1621
1622 static bool is_disconnected(const Node* n) {
1623 for (uint i = 0; i < n->req(); i++) {
1624 if (n->in(i) != NULL) return false;
1625 }
1626 return true;
1627 }
1628
1629 #ifdef ASSERT
1630 static void dump_orig(Node* orig, outputStream *st) {
1631 Compile* C = Compile::current();
1632 if (NotANode(orig)) orig = NULL;
1633 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1634 if (orig == NULL) return;
1635 st->print(" !orig=");
1636 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1637 if (NotANode(fast)) fast = NULL;
1638 while (orig != NULL) {
1639 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1640 if (discon) st->print("[");
1641 if (!Compile::current()->node_arena()->contains(orig))
1642 st->print("o");
1643 st->print("%d", orig->_idx);
1644 if (discon) st->print("]");
1645 orig = orig->debug_orig();
1646 if (NotANode(orig)) orig = NULL;
1647 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1648 if (orig != NULL) st->print(",");
1649 if (fast != NULL) {
1650 // Step fast twice for each single step of orig:
1651 fast = fast->debug_orig();
1652 if (NotANode(fast)) fast = NULL;
1653 if (fast != NULL && fast != orig) {
1654 fast = fast->debug_orig();
1655 if (NotANode(fast)) fast = NULL;
1656 }
1657 if (fast == orig) {
1658 st->print("...");
1659 break;
1660 }
1661 }
1662 }
1663 }
1664
1665 void Node::set_debug_orig(Node* orig) {
1666 _debug_orig = orig;
1667 if (BreakAtNode == 0) return;
1668 if (NotANode(orig)) orig = NULL;
1669 int trip = 10;
1670 while (orig != NULL) {
1671 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1672 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1673 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1674 BREAKPOINT;
1675 }
1676 orig = orig->debug_orig();
1677 if (NotANode(orig)) orig = NULL;
1678 if (trip-- <= 0) break;
1679 }
1680 }
1681 #endif //ASSERT
1682
1683 //------------------------------dump------------------------------------------
1684 // Dump a Node
1685 void Node::dump(const char* suffix, outputStream *st) const {
1686 Compile* C = Compile::current();
1687 bool is_new = C->node_arena()->contains(this);
1688 C->_in_dump_cnt++;
1689 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1690
1691 // Dump the required and precedence inputs
1692 dump_req(st);
1693 dump_prec(st);
1694 // Dump the outputs
1695 dump_out(st);
1696
1697 if (is_disconnected(this)) {
1698 #ifdef ASSERT
1699 st->print(" [%d]",debug_idx());
1700 dump_orig(debug_orig(), st);
1701 #endif
1702 st->cr();
1703 C->_in_dump_cnt--;
1704 return; // don't process dead nodes
1705 }
1706
1707 // Dump node-specific info
1708 dump_spec(st);
1709 #ifdef ASSERT
1710 // Dump the non-reset _debug_idx
1711 if (Verbose && WizardMode) {
1712 st->print(" [%d]",debug_idx());
1713 }
1714 #endif
1715
1716 const Type *t = bottom_type();
1717
1718 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1719 const TypeInstPtr *toop = t->isa_instptr();
1720 const TypeKlassPtr *tkls = t->isa_klassptr();
1721 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1722 if (klass && klass->is_loaded() && klass->is_interface()) {
1723 st->print(" Interface:");
1724 } else if (toop) {
1725 st->print(" Oop:");
1726 } else if (tkls) {
1727 st->print(" Klass:");
1728 }
1729 t->dump_on(st);
1730 } else if (t == Type::MEMORY) {
1731 st->print(" Memory:");
1732 MemNode::dump_adr_type(this, adr_type(), st);
1733 } else if (Verbose || WizardMode) {
1734 st->print(" Type:");
1735 if (t) {
1736 t->dump_on(st);
1737 } else {
1738 st->print("no type");
1739 }
1740 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1741 // Dump MachSpillcopy vector type.
1742 t->dump_on(st);
1743 }
1744 if (is_new) {
1745 debug_only(dump_orig(debug_orig(), st));
1746 Node_Notes* nn = C->node_notes_at(_idx);
1747 if (nn != NULL && !nn->is_clear()) {
1748 if (nn->jvms() != NULL) {
1749 st->print(" !jvms:");
1750 nn->jvms()->dump_spec(st);
1751 }
1752 }
1753 }
1754 if (suffix) st->print("%s", suffix);
1755 C->_in_dump_cnt--;
1756 }
1757
1758 //------------------------------dump_req--------------------------------------
1759 void Node::dump_req(outputStream *st) const {
1760 // Dump the required input edges
1761 for (uint i = 0; i < req(); i++) { // For all required inputs
1762 Node* d = in(i);
1763 if (d == NULL) {
1764 st->print("_ ");
1765 } else if (NotANode(d)) {
1766 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1767 } else {
1768 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1769 }
1770 }
1771 }
1772
1773
1774 //------------------------------dump_prec-------------------------------------
1775 void Node::dump_prec(outputStream *st) const {
1776 // Dump the precedence edges
1777 int any_prec = 0;
1778 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1779 Node* p = in(i);
1780 if (p != NULL) {
1781 if (!any_prec++) st->print(" |");
1782 if (NotANode(p)) { st->print("NotANode "); continue; }
1783 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1784 }
1785 }
1786 }
1787
1788 //------------------------------dump_out--------------------------------------
1789 void Node::dump_out(outputStream *st) const {
1790 // Delimit the output edges
1791 st->print(" [[");
1792 // Dump the output edges
1793 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1794 Node* u = _out[i];
1795 if (u == NULL) {
1796 st->print("_ ");
1797 } else if (NotANode(u)) {
1798 st->print("NotANode ");
1799 } else {
1800 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1801 }
1802 }
1803 st->print("]] ");
1804 }
1805
1806 //------------------------------dump_nodes-------------------------------------
1807 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1808 Node* s = (Node*)start; // remove const
1809 if (NotANode(s)) return;
1810
1811 uint depth = (uint)ABS(d);
1812 int direction = d;
1813 Compile* C = Compile::current();
1814 GrowableArray <Node *> nstack(C->live_nodes());
1815
1816 nstack.append(s);
1817 int begin = 0;
1818 int end = 0;
1819 for(uint i = 0; i < depth; i++) {
1820 end = nstack.length();
1821 for(int j = begin; j < end; j++) {
1822 Node* tp = nstack.at(j);
1823 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1824 for(uint k = 0; k < limit; k++) {
1825 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1826
1827 if (NotANode(n)) continue;
1828 // do not recurse through top or the root (would reach unrelated stuff)
1829 if (n->is_Root() || n->is_top()) continue;
1830 if (only_ctrl && !n->is_CFG()) continue;
1831
1832 bool on_stack = nstack.contains(n);
1833 if (!on_stack) {
1834 nstack.append(n);
1835 }
1836 }
1837 }
1838 begin = end;
1839 }
1840 end = nstack.length();
1841 if (direction > 0) {
1842 for(int j = end-1; j >= 0; j--) {
1843 nstack.at(j)->dump();
1844 }
1845 } else {
1846 for(int j = 0; j < end; j++) {
1847 nstack.at(j)->dump();
1848 }
1849 }
1850 }
1851
1852 //------------------------------dump-------------------------------------------
1853 void Node::dump(int d) const {
1854 dump_nodes(this, d, false);
1855 }
1856
1857 //------------------------------dump_ctrl--------------------------------------
1858 // Dump a Node's control history to depth
1859 void Node::dump_ctrl(int d) const {
1860 dump_nodes(this, d, true);
1861 }
1862
1863 // VERIFICATION CODE
1864 // For each input edge to a node (ie - for each Use-Def edge), verify that
1865 // there is a corresponding Def-Use edge.
1866 //------------------------------verify_edges-----------------------------------
1867 void Node::verify_edges(Unique_Node_List &visited) {
1868 uint i, j, idx;
1869 int cnt;
1870 Node *n;
1871
1872 // Recursive termination test
1873 if (visited.member(this)) return;
1874 visited.push(this);
1875
1876 // Walk over all input edges, checking for correspondence
1877 for( i = 0; i < len(); i++ ) {
1878 n = in(i);
1879 if (n != NULL && !n->is_top()) {
1880 // Count instances of (Node *)this
1881 cnt = 0;
1882 for (idx = 0; idx < n->_outcnt; idx++ ) {
1883 if (n->_out[idx] == (Node *)this) cnt++;
1884 }
1885 assert( cnt > 0,"Failed to find Def-Use edge." );
1886 // Check for duplicate edges
1887 // walk the input array downcounting the input edges to n
1888 for( j = 0; j < len(); j++ ) {
1889 if( in(j) == n ) cnt--;
1890 }
1891 assert( cnt == 0,"Mismatched edge count.");
1892 } else if (n == NULL) {
1893 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1894 } else {
1895 assert(n->is_top(), "sanity");
1896 // Nothing to check.
1897 }
1898 }
1899 // Recursive walk over all input edges
1900 for( i = 0; i < len(); i++ ) {
1901 n = in(i);
1902 if( n != NULL )
1903 in(i)->verify_edges(visited);
1904 }
1905 }
1906
1907 //------------------------------verify_recur-----------------------------------
1908 static const Node *unique_top = NULL;
1909
1910 void Node::verify_recur(const Node *n, int verify_depth,
1911 VectorSet &old_space, VectorSet &new_space) {
1912 if ( verify_depth == 0 ) return;
1913 if (verify_depth > 0) --verify_depth;
1914
1915 Compile* C = Compile::current();
1916
1917 // Contained in new_space or old_space?
1918 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1919 // Check for visited in the proper space. Numberings are not unique
1920 // across spaces so we need a separate VectorSet for each space.
1921 if( v->test_set(n->_idx) ) return;
1922
1923 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1924 if (C->cached_top_node() == NULL)
1925 C->set_cached_top_node((Node*)n);
1926 assert(C->cached_top_node() == n, "TOP node must be unique");
1927 }
1928
1929 for( uint i = 0; i < n->len(); i++ ) {
1930 Node *x = n->in(i);
1931 if (!x || x->is_top()) continue;
1932
1933 // Verify my input has a def-use edge to me
1934 if (true /*VerifyDefUse*/) {
1935 // Count use-def edges from n to x
1936 int cnt = 0;
1937 for( uint j = 0; j < n->len(); j++ )
1938 if( n->in(j) == x )
1939 cnt++;
1940 // Count def-use edges from x to n
1941 uint max = x->_outcnt;
1942 for( uint k = 0; k < max; k++ )
1943 if (x->_out[k] == n)
1944 cnt--;
1945 assert( cnt == 0, "mismatched def-use edge counts" );
1946 }
1947
1948 verify_recur(x, verify_depth, old_space, new_space);
1949 }
1950
1951 }
1952
1953 //------------------------------verify-----------------------------------------
1954 // Check Def-Use info for my subgraph
1955 void Node::verify() const {
1956 Compile* C = Compile::current();
1957 Node* old_top = C->cached_top_node();
1958 ResourceMark rm;
1959 ResourceArea *area = Thread::current()->resource_area();
1960 VectorSet old_space(area), new_space(area);
1961 verify_recur(this, -1, old_space, new_space);
1962 C->set_cached_top_node(old_top);
1963 }
1964 #endif
1965
1966
1967 //------------------------------walk-------------------------------------------
1968 // Graph walk, with both pre-order and post-order functions
1969 void Node::walk(NFunc pre, NFunc post, void *env) {
1970 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1971 walk_(pre, post, env, visited);
1972 }
1973
1974 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1975 if( visited.test_set(_idx) ) return;
1976 pre(*this,env); // Call the pre-order walk function
1977 for( uint i=0; i<_max; i++ )
1978 if( in(i) ) // Input exists and is not walked?
1979 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1980 post(*this,env); // Call the post-order walk function
1981 }
1982
1983 void Node::nop(Node &, void*) {}
1984
1985 //------------------------------Registers--------------------------------------
1986 // Do we Match on this edge index or not? Generally false for Control
1987 // and true for everything else. Weird for calls & returns.
1988 uint Node::match_edge(uint idx) const {
1989 return idx; // True for other than index 0 (control)
1990 }
1991
1992 static RegMask _not_used_at_all;
1993 // Register classes are defined for specific machines
1994 const RegMask &Node::out_RegMask() const {
1995 ShouldNotCallThis();
1996 return _not_used_at_all;
1997 }
1998
1999 const RegMask &Node::in_RegMask(uint) const {
2000 ShouldNotCallThis();
2001 return _not_used_at_all;
2002 }
2003
2004 //=============================================================================
2005 //-----------------------------------------------------------------------------
2006 void Node_Array::reset( Arena *new_arena ) {
2007 _a->Afree(_nodes,_max*sizeof(Node*));
2008 _max = 0;
2009 _nodes = NULL;
2010 _a = new_arena;
2011 }
2012
2013 //------------------------------clear------------------------------------------
2014 // Clear all entries in _nodes to NULL but keep storage
2015 void Node_Array::clear() {
2016 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2017 }
2018
2019 //-----------------------------------------------------------------------------
2020 void Node_Array::grow( uint i ) {
2021 if( !_max ) {
2022 _max = 1;
2023 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2024 _nodes[0] = NULL;
2025 }
2026 uint old = _max;
2027 while( i >= _max ) _max <<= 1; // Double to fit
2028 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2029 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2030 }
2031
2032 //-----------------------------------------------------------------------------
2033 void Node_Array::insert( uint i, Node *n ) {
2034 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2035 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2036 _nodes[i] = n;
2037 }
2038
2039 //-----------------------------------------------------------------------------
2040 void Node_Array::remove( uint i ) {
2041 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2042 _nodes[_max-1] = NULL;
2043 }
2044
2045 //-----------------------------------------------------------------------------
2046 void Node_Array::sort( C_sort_func_t func) {
2047 qsort( _nodes, _max, sizeof( Node* ), func );
2048 }
2049
2050 //-----------------------------------------------------------------------------
2051 void Node_Array::dump() const {
2052 #ifndef PRODUCT
2053 for( uint i = 0; i < _max; i++ ) {
2054 Node *nn = _nodes[i];
2055 if( nn != NULL ) {
2056 tty->print("%5d--> ",i); nn->dump();
2057 }
2058 }
2059 #endif
2060 }
2061
2062 //--------------------------is_iteratively_computed------------------------------
2063 // Operation appears to be iteratively computed (such as an induction variable)
2064 // It is possible for this operation to return false for a loop-varying
2065 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2066 bool Node::is_iteratively_computed() {
2067 if (ideal_reg()) { // does operation have a result register?
2068 for (uint i = 1; i < req(); i++) {
2069 Node* n = in(i);
2070 if (n != NULL && n->is_Phi()) {
2071 for (uint j = 1; j < n->req(); j++) {
2072 if (n->in(j) == this) {
2073 return true;
2074 }
2075 }
2076 }
2077 }
2078 }
2079 return false;
2080 }
2081
2082 //--------------------------find_similar------------------------------
2083 // Return a node with opcode "opc" and same inputs as "this" if one can
2084 // be found; Otherwise return NULL;
2085 Node* Node::find_similar(int opc) {
2086 if (req() >= 2) {
2087 Node* def = in(1);
2088 if (def && def->outcnt() >= 2) {
2089 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2090 Node* use = def->fast_out(i);
2091 if (use->Opcode() == opc &&
2092 use->req() == req()) {
2093 uint j;
2094 for (j = 0; j < use->req(); j++) {
2095 if (use->in(j) != in(j)) {
2096 break;
2097 }
2098 }
2099 if (j == use->req()) {
2100 return use;
2101 }
2102 }
2103 }
2104 }
2105 }
2106 return NULL;
2107 }
2108
2109
2110 //--------------------------unique_ctrl_out------------------------------
2111 // Return the unique control out if only one. Null if none or more than one.
2112 Node* Node::unique_ctrl_out() {
2113 Node* found = NULL;
2114 for (uint i = 0; i < outcnt(); i++) {
2115 Node* use = raw_out(i);
2116 if (use->is_CFG() && use != this) {
2117 if (found != NULL) return NULL;
2118 found = use;
2119 }
2120 }
2121 return found;
2122 }
2123
2124 void Node::ensure_control_or_add_prec(Node* c) {
2125 if (in(0) == NULL) {
2126 set_req(0, c);
2127 } else if (in(0) != c) {
2128 add_prec(c);
2129 }
2130 }
2131
2132 //=============================================================================
2133 //------------------------------yank-------------------------------------------
2134 // Find and remove
2135 void Node_List::yank( Node *n ) {
2136 uint i;
2137 for( i = 0; i < _cnt; i++ )
2138 if( _nodes[i] == n )
2139 break;
2140
2141 if( i < _cnt )
2142 _nodes[i] = _nodes[--_cnt];
2143 }
2144
2145 //------------------------------dump-------------------------------------------
2146 void Node_List::dump() const {
2147 #ifndef PRODUCT
2148 for( uint i = 0; i < _cnt; i++ )
2149 if( _nodes[i] ) {
2150 tty->print("%5d--> ",i);
2151 _nodes[i]->dump();
2152 }
2153 #endif
2154 }
2155
2156 void Node_List::dump_simple() const {
2157 #ifndef PRODUCT
2158 for( uint i = 0; i < _cnt; i++ )
2159 if( _nodes[i] ) {
2160 tty->print(" %d", _nodes[i]->_idx);
2161 } else {
2162 tty->print(" NULL");
2163 }
2164 #endif
2165 }
2166
2167 //=============================================================================
2168 //------------------------------remove-----------------------------------------
2169 void Unique_Node_List::remove( Node *n ) {
2170 if( _in_worklist[n->_idx] ) {
2171 for( uint i = 0; i < size(); i++ )
2172 if( _nodes[i] == n ) {
2173 map(i,Node_List::pop());
2174 _in_worklist >>= n->_idx;
2175 return;
2176 }
2177 ShouldNotReachHere();
2178 }
2179 }
2180
2181 //-----------------------remove_useless_nodes----------------------------------
2182 // Remove useless nodes from worklist
2183 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2184
2185 for( uint i = 0; i < size(); ++i ) {
2186 Node *n = at(i);
2187 assert( n != NULL, "Did not expect null entries in worklist");
2188 if( ! useful.test(n->_idx) ) {
2189 _in_worklist >>= n->_idx;
2190 map(i,Node_List::pop());
2191 // Node *replacement = Node_List::pop();
2192 // if( i != size() ) { // Check if removing last entry
2193 // _nodes[i] = replacement;
2194 // }
2195 --i; // Visit popped node
2196 // If it was last entry, loop terminates since size() was also reduced
2197 }
2198 }
2199 }
2200
2201 //=============================================================================
2202 void Node_Stack::grow() {
2203 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2204 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2205 size_t max = old_max << 1; // max * 2
2206 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2207 _inode_max = _inodes + max;
2208 _inode_top = _inodes + old_top; // restore _top
2209 }
2210
2211 // Node_Stack is used to map nodes.
2212 Node* Node_Stack::find(uint idx) const {
2213 uint sz = size();
2214 for (uint i=0; i < sz; i++) {
2215 if (idx == index_at(i) )
2216 return node_at(i);
2217 }
2218 return NULL;
2219 }
2220
2221 //=============================================================================
2222 uint TypeNode::size_of() const { return sizeof(*this); }
2223 #ifndef PRODUCT
2224 void TypeNode::dump_spec(outputStream *st) const {
2225 if( !Verbose && !WizardMode ) {
2226 // standard dump does this in Verbose and WizardMode
2227 st->print(" #"); _type->dump_on(st);
2228 }
2229 }
2230 #endif
2231 uint TypeNode::hash() const {
2232 return Node::hash() + _type->hash();
2233 }
2234 uint TypeNode::cmp( const Node &n ) const
2235 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2236 const Type *TypeNode::bottom_type() const { return _type; }
2237 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2238
2239 //------------------------------ideal_reg--------------------------------------
2240 uint TypeNode::ideal_reg() const {
2241 return _type->ideal_reg();
2242 }