1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "libadt/vectset.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "opto/cfgnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/loopnode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/node.hpp"
34 #include "opto/opcodes.hpp"
35 #include "opto/regmask.hpp"
36 #include "opto/type.hpp"
37 #include "utilities/copy.hpp"
38 #if INCLUDE_ALL_GCS
39 #include "gc_implementation/shenandoah/c2/shenandoahSupport.hpp"
40 #endif
41
42 class RegMask;
43 // #include "phase.hpp"
44 class PhaseTransform;
45 class PhaseGVN;
46
47 // Arena we are currently building Nodes in
48 const uint Node::NotAMachineReg = 0xffff0000;
49
50 #ifndef PRODUCT
51 extern int nodes_created;
52 #endif
53
54 #ifdef ASSERT
55
56 //-------------------------- construct_node------------------------------------
57 // Set a breakpoint here to identify where a particular node index is built.
58 void Node::verify_construction() {
59 _debug_orig = NULL;
60 int old_debug_idx = Compile::debug_idx();
61 int new_debug_idx = old_debug_idx+1;
62 if (new_debug_idx > 0) {
63 // Arrange that the lowest five decimal digits of _debug_idx
64 // will repeat those of _idx. In case this is somehow pathological,
65 // we continue to assign negative numbers (!) consecutively.
66 const int mod = 100000;
67 int bump = (int)(_idx - new_debug_idx) % mod;
68 if (bump < 0) bump += mod;
69 assert(bump >= 0 && bump < mod, "");
70 new_debug_idx += bump;
71 }
72 Compile::set_debug_idx(new_debug_idx);
73 set_debug_idx( new_debug_idx );
74 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
75 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
76 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
77 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
78 BREAKPOINT;
79 }
80 #if OPTO_DU_ITERATOR_ASSERT
81 _last_del = NULL;
82 _del_tick = 0;
83 #endif
84 _hash_lock = 0;
85 }
86
87
88 // #ifdef ASSERT ...
89
90 #if OPTO_DU_ITERATOR_ASSERT
91 void DUIterator_Common::sample(const Node* node) {
92 _vdui = VerifyDUIterators;
93 _node = node;
94 _outcnt = node->_outcnt;
95 _del_tick = node->_del_tick;
96 _last = NULL;
97 }
98
99 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
100 assert(_node == node, "consistent iterator source");
101 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
102 }
103
104 void DUIterator_Common::verify_resync() {
105 // Ensure that the loop body has just deleted the last guy produced.
106 const Node* node = _node;
107 // Ensure that at least one copy of the last-seen edge was deleted.
108 // Note: It is OK to delete multiple copies of the last-seen edge.
109 // Unfortunately, we have no way to verify that all the deletions delete
110 // that same edge. On this point we must use the Honor System.
111 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
112 assert(node->_last_del == _last, "must have deleted the edge just produced");
113 // We liked this deletion, so accept the resulting outcnt and tick.
114 _outcnt = node->_outcnt;
115 _del_tick = node->_del_tick;
116 }
117
118 void DUIterator_Common::reset(const DUIterator_Common& that) {
119 if (this == &that) return; // ignore assignment to self
120 if (!_vdui) {
121 // We need to initialize everything, overwriting garbage values.
122 _last = that._last;
123 _vdui = that._vdui;
124 }
125 // Note: It is legal (though odd) for an iterator over some node x
126 // to be reassigned to iterate over another node y. Some doubly-nested
127 // progress loops depend on being able to do this.
128 const Node* node = that._node;
129 // Re-initialize everything, except _last.
130 _node = node;
131 _outcnt = node->_outcnt;
132 _del_tick = node->_del_tick;
133 }
134
135 void DUIterator::sample(const Node* node) {
136 DUIterator_Common::sample(node); // Initialize the assertion data.
137 _refresh_tick = 0; // No refreshes have happened, as yet.
138 }
139
140 void DUIterator::verify(const Node* node, bool at_end_ok) {
141 DUIterator_Common::verify(node, at_end_ok);
142 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
143 }
144
145 void DUIterator::verify_increment() {
146 if (_refresh_tick & 1) {
147 // We have refreshed the index during this loop.
148 // Fix up _idx to meet asserts.
149 if (_idx > _outcnt) _idx = _outcnt;
150 }
151 verify(_node, true);
152 }
153
154 void DUIterator::verify_resync() {
155 // Note: We do not assert on _outcnt, because insertions are OK here.
156 DUIterator_Common::verify_resync();
157 // Make sure we are still in sync, possibly with no more out-edges:
158 verify(_node, true);
159 }
160
161 void DUIterator::reset(const DUIterator& that) {
162 if (this == &that) return; // self assignment is always a no-op
163 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
164 assert(that._idx == 0, "assign only the result of Node::outs()");
165 assert(_idx == that._idx, "already assigned _idx");
166 if (!_vdui) {
167 // We need to initialize everything, overwriting garbage values.
168 sample(that._node);
169 } else {
170 DUIterator_Common::reset(that);
171 if (_refresh_tick & 1) {
172 _refresh_tick++; // Clear the "was refreshed" flag.
173 }
174 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
175 }
176 }
177
178 void DUIterator::refresh() {
179 DUIterator_Common::sample(_node); // Re-fetch assertion data.
180 _refresh_tick |= 1; // Set the "was refreshed" flag.
181 }
182
183 void DUIterator::verify_finish() {
184 // If the loop has killed the node, do not require it to re-run.
185 if (_node->_outcnt == 0) _refresh_tick &= ~1;
186 // If this assert triggers, it means that a loop used refresh_out_pos
187 // to re-synch an iteration index, but the loop did not correctly
188 // re-run itself, using a "while (progress)" construct.
189 // This iterator enforces the rule that you must keep trying the loop
190 // until it "runs clean" without any need for refreshing.
191 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
192 }
193
194
195 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
196 DUIterator_Common::verify(node, at_end_ok);
197 Node** out = node->_out;
198 uint cnt = node->_outcnt;
199 assert(cnt == _outcnt, "no insertions allowed");
200 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
201 // This last check is carefully designed to work for NO_OUT_ARRAY.
202 }
203
204 void DUIterator_Fast::verify_limit() {
205 const Node* node = _node;
206 verify(node, true);
207 assert(_outp == node->_out + node->_outcnt, "limit still correct");
208 }
209
210 void DUIterator_Fast::verify_resync() {
211 const Node* node = _node;
212 if (_outp == node->_out + _outcnt) {
213 // Note that the limit imax, not the pointer i, gets updated with the
214 // exact count of deletions. (For the pointer it's always "--i".)
215 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
216 // This is a limit pointer, with a name like "imax".
217 // Fudge the _last field so that the common assert will be happy.
218 _last = (Node*) node->_last_del;
219 DUIterator_Common::verify_resync();
220 } else {
221 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
222 // A normal internal pointer.
223 DUIterator_Common::verify_resync();
224 // Make sure we are still in sync, possibly with no more out-edges:
225 verify(node, true);
226 }
227 }
228
229 void DUIterator_Fast::verify_relimit(uint n) {
230 const Node* node = _node;
231 assert((int)n > 0, "use imax -= n only with a positive count");
232 // This must be a limit pointer, with a name like "imax".
233 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
234 // The reported number of deletions must match what the node saw.
235 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
236 // Fudge the _last field so that the common assert will be happy.
237 _last = (Node*) node->_last_del;
238 DUIterator_Common::verify_resync();
239 }
240
241 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
242 assert(_outp == that._outp, "already assigned _outp");
243 DUIterator_Common::reset(that);
244 }
245
246 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
247 // at_end_ok means the _outp is allowed to underflow by 1
248 _outp += at_end_ok;
249 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
250 _outp -= at_end_ok;
251 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
252 }
253
254 void DUIterator_Last::verify_limit() {
255 // Do not require the limit address to be resynched.
256 //verify(node, true);
257 assert(_outp == _node->_out, "limit still correct");
258 }
259
260 void DUIterator_Last::verify_step(uint num_edges) {
261 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
262 _outcnt -= num_edges;
263 _del_tick += num_edges;
264 // Make sure we are still in sync, possibly with no more out-edges:
265 const Node* node = _node;
266 verify(node, true);
267 assert(node->_last_del == _last, "must have deleted the edge just produced");
268 }
269
270 #endif //OPTO_DU_ITERATOR_ASSERT
271
272
273 #endif //ASSERT
274
275
276 // This constant used to initialize _out may be any non-null value.
277 // The value NULL is reserved for the top node only.
278 #define NO_OUT_ARRAY ((Node**)-1)
279
280 // This funny expression handshakes with Node::operator new
281 // to pull Compile::current out of the new node's _out field,
282 // and then calls a subroutine which manages most field
283 // initializations. The only one which is tricky is the
284 // _idx field, which is const, and so must be initialized
285 // by a return value, not an assignment.
286 //
287 // (Aren't you thankful that Java finals don't require so many tricks?)
288 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
289 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
290 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
291 #endif
292 #ifdef __clang__
293 #pragma clang diagnostic push
294 #pragma GCC diagnostic ignored "-Wuninitialized"
295 #endif
296
297 // Out-of-line code from node constructors.
298 // Executed only when extra debug info. is being passed around.
299 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
300 C->set_node_notes_at(idx, nn);
301 }
302
303 // Shared initialization code.
304 inline int Node::Init(int req, Compile* C) {
305 assert(Compile::current() == C, "must use operator new(Compile*)");
306 int idx = C->next_unique();
307
308 // Allocate memory for the necessary number of edges.
309 if (req > 0) {
310 // Allocate space for _in array to have double alignment.
311 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
312 #ifdef ASSERT
313 _in[req-1] = this; // magic cookie for assertion check
314 #endif
315 }
316 // If there are default notes floating around, capture them:
317 Node_Notes* nn = C->default_node_notes();
318 if (nn != NULL) init_node_notes(C, idx, nn);
319
320 // Note: At this point, C is dead,
321 // and we begin to initialize the new Node.
322
323 _cnt = _max = req;
324 _outcnt = _outmax = 0;
325 _class_id = Class_Node;
326 _flags = 0;
327 _out = NO_OUT_ARRAY;
328 return idx;
329 }
330
331 //------------------------------Node-------------------------------------------
332 // Create a Node, with a given number of required edges.
333 Node::Node(uint req)
334 : _idx(IDX_INIT(req))
335 #ifdef ASSERT
336 , _parse_idx(_idx)
337 #endif
338 {
339 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
340 debug_only( verify_construction() );
341 NOT_PRODUCT(nodes_created++);
342 if (req == 0) {
343 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
344 _in = NULL;
345 } else {
346 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
347 Node** to = _in;
348 for(uint i = 0; i < req; i++) {
349 to[i] = NULL;
350 }
351 }
352 }
353
354 //------------------------------Node-------------------------------------------
355 Node::Node(Node *n0)
356 : _idx(IDX_INIT(1))
357 #ifdef ASSERT
358 , _parse_idx(_idx)
359 #endif
360 {
361 debug_only( verify_construction() );
362 NOT_PRODUCT(nodes_created++);
363 // Assert we allocated space for input array already
364 assert( _in[0] == this, "Must pass arg count to 'new'" );
365 assert( is_not_dead(n0), "can not use dead node");
366 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
367 }
368
369 //------------------------------Node-------------------------------------------
370 Node::Node(Node *n0, Node *n1)
371 : _idx(IDX_INIT(2))
372 #ifdef ASSERT
373 , _parse_idx(_idx)
374 #endif
375 {
376 debug_only( verify_construction() );
377 NOT_PRODUCT(nodes_created++);
378 // Assert we allocated space for input array already
379 assert( _in[1] == this, "Must pass arg count to 'new'" );
380 assert( is_not_dead(n0), "can not use dead node");
381 assert( is_not_dead(n1), "can not use dead node");
382 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
383 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
384 }
385
386 //------------------------------Node-------------------------------------------
387 Node::Node(Node *n0, Node *n1, Node *n2)
388 : _idx(IDX_INIT(3))
389 #ifdef ASSERT
390 , _parse_idx(_idx)
391 #endif
392 {
393 debug_only( verify_construction() );
394 NOT_PRODUCT(nodes_created++);
395 // Assert we allocated space for input array already
396 assert( _in[2] == 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 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
401 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
402 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
403 }
404
405 //------------------------------Node-------------------------------------------
406 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
407 : _idx(IDX_INIT(4))
408 #ifdef ASSERT
409 , _parse_idx(_idx)
410 #endif
411 {
412 debug_only( verify_construction() );
413 NOT_PRODUCT(nodes_created++);
414 // Assert we allocated space for input array already
415 assert( _in[3] == this, "Must pass arg count to 'new'" );
416 assert( is_not_dead(n0), "can not use dead node");
417 assert( is_not_dead(n1), "can not use dead node");
418 assert( is_not_dead(n2), "can not use dead node");
419 assert( is_not_dead(n3), "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 }
425
426 //------------------------------Node-------------------------------------------
427 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
428 : _idx(IDX_INIT(5))
429 #ifdef ASSERT
430 , _parse_idx(_idx)
431 #endif
432 {
433 debug_only( verify_construction() );
434 NOT_PRODUCT(nodes_created++);
435 // Assert we allocated space for input array already
436 assert( _in[4] == this, "Must pass arg count to 'new'" );
437 assert( is_not_dead(n0), "can not use dead node");
438 assert( is_not_dead(n1), "can not use dead node");
439 assert( is_not_dead(n2), "can not use dead node");
440 assert( is_not_dead(n3), "can not use dead node");
441 assert( is_not_dead(n4), "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 }
448
449 //------------------------------Node-------------------------------------------
450 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
451 Node *n4, Node *n5)
452 : _idx(IDX_INIT(6))
453 #ifdef ASSERT
454 , _parse_idx(_idx)
455 #endif
456 {
457 debug_only( verify_construction() );
458 NOT_PRODUCT(nodes_created++);
459 // Assert we allocated space for input array already
460 assert( _in[5] == this, "Must pass arg count to 'new'" );
461 assert( is_not_dead(n0), "can not use dead node");
462 assert( is_not_dead(n1), "can not use dead node");
463 assert( is_not_dead(n2), "can not use dead node");
464 assert( is_not_dead(n3), "can not use dead node");
465 assert( is_not_dead(n4), "can not use dead node");
466 assert( is_not_dead(n5), "can not use dead node");
467 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
468 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
469 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
470 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
471 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
472 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
473 }
474
475 //------------------------------Node-------------------------------------------
476 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
477 Node *n4, Node *n5, Node *n6)
478 : _idx(IDX_INIT(7))
479 #ifdef ASSERT
480 , _parse_idx(_idx)
481 #endif
482 {
483 debug_only( verify_construction() );
484 NOT_PRODUCT(nodes_created++);
485 // Assert we allocated space for input array already
486 assert( _in[6] == this, "Must pass arg count to 'new'" );
487 assert( is_not_dead(n0), "can not use dead node");
488 assert( is_not_dead(n1), "can not use dead node");
489 assert( is_not_dead(n2), "can not use dead node");
490 assert( is_not_dead(n3), "can not use dead node");
491 assert( is_not_dead(n4), "can not use dead node");
492 assert( is_not_dead(n5), "can not use dead node");
493 assert( is_not_dead(n6), "can not use dead node");
494 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
495 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
496 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
497 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
498 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
499 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
500 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
501 }
502
503 #ifdef __clang__
504 #pragma clang diagnostic pop
505 #endif
506
507
508 //------------------------------clone------------------------------------------
509 // Clone a Node.
510 Node *Node::clone() const {
511 Compile* C = Compile::current();
512 uint s = size_of(); // Size of inherited Node
513 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
514 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
515 // Set the new input pointer array
516 n->_in = (Node**)(((char*)n)+s);
517 // Cannot share the old output pointer array, so kill it
518 n->_out = NO_OUT_ARRAY;
519 // And reset the counters to 0
520 n->_outcnt = 0;
521 n->_outmax = 0;
522 // Unlock this guy, since he is not in any hash table.
523 debug_only(n->_hash_lock = 0);
524 // Walk the old node's input list to duplicate its edges
525 uint i;
526 for( i = 0; i < len(); i++ ) {
527 Node *x = in(i);
528 n->_in[i] = x;
529 if (x != NULL) x->add_out(n);
530 }
531 if (is_macro())
532 C->add_macro_node(n);
533 if (is_expensive())
534 C->add_expensive_node(n);
535
536 if (Opcode() == Op_ShenandoahLoadReferenceBarrier) {
537 C->add_shenandoah_barrier(reinterpret_cast<ShenandoahLoadReferenceBarrierNode*>(n));
538 }
539 // If the cloned node is a range check dependent CastII, add it to the list.
540 CastIINode* cast = n->isa_CastII();
541 if (cast != NULL && cast->has_range_check()) {
542 C->add_range_check_cast(cast);
543 }
544
545 n->set_idx(C->next_unique()); // Get new unique index as well
546 debug_only( n->verify_construction() );
547 NOT_PRODUCT(nodes_created++);
548 // Do not patch over the debug_idx of a clone, because it makes it
549 // impossible to break on the clone's moment of creation.
550 //debug_only( n->set_debug_idx( debug_idx() ) );
551
552 C->copy_node_notes_to(n, (Node*) this);
553
554 // MachNode clone
555 uint nopnds;
556 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
557 MachNode *mach = n->as_Mach();
558 MachNode *mthis = this->as_Mach();
559 // Get address of _opnd_array.
560 // It should be the same offset since it is the clone of this node.
561 MachOper **from = mthis->_opnds;
562 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
563 pointer_delta((const void*)from,
564 (const void*)(&mthis->_opnds), 1));
565 mach->_opnds = to;
566 for ( uint i = 0; i < nopnds; ++i ) {
567 to[i] = from[i]->clone(C);
568 }
569 }
570 // cloning CallNode may need to clone JVMState
571 if (n->is_Call()) {
572 n->as_Call()->clone_jvms(C);
573 }
574 if (n->is_SafePoint()) {
575 n->as_SafePoint()->clone_replaced_nodes();
576 }
577 return n; // Return the clone
578 }
579
580 //---------------------------setup_is_top--------------------------------------
581 // Call this when changing the top node, to reassert the invariants
582 // required by Node::is_top. See Compile::set_cached_top_node.
583 void Node::setup_is_top() {
584 if (this == (Node*)Compile::current()->top()) {
585 // This node has just become top. Kill its out array.
586 _outcnt = _outmax = 0;
587 _out = NULL; // marker value for top
588 assert(is_top(), "must be top");
589 } else {
590 if (_out == NULL) _out = NO_OUT_ARRAY;
591 assert(!is_top(), "must not be top");
592 }
593 }
594
595
596 //------------------------------~Node------------------------------------------
597 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
598 extern int reclaim_idx ;
599 extern int reclaim_in ;
600 extern int reclaim_node;
601 void Node::destruct() {
602 // Eagerly reclaim unique Node numberings
603 Compile* compile = Compile::current();
604 if ((uint)_idx+1 == compile->unique()) {
605 compile->set_unique(compile->unique()-1);
606 #ifdef ASSERT
607 reclaim_idx++;
608 #endif
609 }
610 // Clear debug info:
611 Node_Notes* nn = compile->node_notes_at(_idx);
612 if (nn != NULL) nn->clear();
613 // Walk the input array, freeing the corresponding output edges
614 _cnt = _max; // forget req/prec distinction
615 uint i;
616 for( i = 0; i < _max; i++ ) {
617 set_req(i, NULL);
618 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
619 }
620 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
621 // See if the input array was allocated just prior to the object
622 int edge_size = _max*sizeof(void*);
623 int out_edge_size = _outmax*sizeof(void*);
624 char *edge_end = ((char*)_in) + edge_size;
625 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
626 char *out_edge_end = out_array + out_edge_size;
627 int node_size = size_of();
628
629 // Free the output edge array
630 if (out_edge_size > 0) {
631 #ifdef ASSERT
632 if( out_edge_end == compile->node_arena()->hwm() )
633 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
634 #endif
635 compile->node_arena()->Afree(out_array, out_edge_size);
636 }
637
638 // Free the input edge array and the node itself
639 if( edge_end == (char*)this ) {
640 #ifdef ASSERT
641 if( edge_end+node_size == compile->node_arena()->hwm() ) {
642 reclaim_in += edge_size;
643 reclaim_node+= node_size;
644 }
645 #else
646 // It was; free the input array and object all in one hit
647 compile->node_arena()->Afree(_in,edge_size+node_size);
648 #endif
649 } else {
650
651 // Free just the input array
652 #ifdef ASSERT
653 if( edge_end == compile->node_arena()->hwm() )
654 reclaim_in += edge_size;
655 #endif
656 compile->node_arena()->Afree(_in,edge_size);
657
658 // Free just the object
659 #ifdef ASSERT
660 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
661 reclaim_node+= node_size;
662 #else
663 compile->node_arena()->Afree(this,node_size);
664 #endif
665 }
666 if (is_macro()) {
667 compile->remove_macro_node(this);
668 }
669 if (is_expensive()) {
670 compile->remove_expensive_node(this);
671 }
672 if (Opcode() == Op_ShenandoahLoadReferenceBarrier) {
673 compile->remove_shenandoah_barrier(reinterpret_cast<ShenandoahLoadReferenceBarrierNode*>(this));
674 }
675 CastIINode* cast = isa_CastII();
676 if (cast != NULL && cast->has_range_check()) {
677 compile->remove_range_check_cast(cast);
678 }
679
680 if (is_SafePoint()) {
681 as_SafePoint()->delete_replaced_nodes();
682 }
683 #ifdef ASSERT
684 // We will not actually delete the storage, but we'll make the node unusable.
685 *(address*)this = badAddress; // smash the C++ vtbl, probably
686 _in = _out = (Node**) badAddress;
687 _max = _cnt = _outmax = _outcnt = 0;
688 #endif
689 }
690
691 //------------------------------grow-------------------------------------------
692 // Grow the input array, making space for more edges
693 void Node::grow( uint len ) {
694 Arena* arena = Compile::current()->node_arena();
695 uint new_max = _max;
696 if( new_max == 0 ) {
697 _max = 4;
698 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
699 Node** to = _in;
700 to[0] = NULL;
701 to[1] = NULL;
702 to[2] = NULL;
703 to[3] = NULL;
704 return;
705 }
706 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
707 // Trimming to limit allows a uint8 to handle up to 255 edges.
708 // Previously I was using only powers-of-2 which peaked at 128 edges.
709 //if( new_max >= limit ) new_max = limit-1;
710 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
711 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
712 _max = new_max; // Record new max length
713 // This assertion makes sure that Node::_max is wide enough to
714 // represent the numerical value of new_max.
715 assert(_max == new_max && _max > len, "int width of _max is too small");
716 }
717
718 //-----------------------------out_grow----------------------------------------
719 // Grow the input array, making space for more edges
720 void Node::out_grow( uint len ) {
721 assert(!is_top(), "cannot grow a top node's out array");
722 Arena* arena = Compile::current()->node_arena();
723 uint new_max = _outmax;
724 if( new_max == 0 ) {
725 _outmax = 4;
726 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
727 return;
728 }
729 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
730 // Trimming to limit allows a uint8 to handle up to 255 edges.
731 // Previously I was using only powers-of-2 which peaked at 128 edges.
732 //if( new_max >= limit ) new_max = limit-1;
733 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
734 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
735 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
736 _outmax = new_max; // Record new max length
737 // This assertion makes sure that Node::_max is wide enough to
738 // represent the numerical value of new_max.
739 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
740 }
741
742 #ifdef ASSERT
743 //------------------------------is_dead----------------------------------------
744 bool Node::is_dead() const {
745 // Mach and pinch point nodes may look like dead.
746 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
747 return false;
748 for( uint i = 0; i < _max; i++ )
749 if( _in[i] != NULL )
750 return false;
751 dump();
752 return true;
753 }
754 #endif
755
756
757 //------------------------------is_unreachable---------------------------------
758 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
759 assert(!is_Mach(), "doesn't work with MachNodes");
760 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
761 }
762
763 //------------------------------add_req----------------------------------------
764 // Add a new required input at the end
765 void Node::add_req( Node *n ) {
766 assert( is_not_dead(n), "can not use dead node");
767
768 // Look to see if I can move precedence down one without reallocating
769 if( (_cnt >= _max) || (in(_max-1) != NULL) )
770 grow( _max+1 );
771
772 // Find a precedence edge to move
773 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
774 uint i;
775 for( i=_cnt; i<_max; i++ )
776 if( in(i) == NULL ) // Find the NULL at end of prec edge list
777 break; // There must be one, since we grew the array
778 _in[i] = in(_cnt); // Move prec over, making space for req edge
779 }
780 _in[_cnt++] = n; // Stuff over old prec edge
781 if (n != NULL) n->add_out((Node *)this);
782 }
783
784 //---------------------------add_req_batch-------------------------------------
785 // Add a new required input at the end
786 void Node::add_req_batch( Node *n, uint m ) {
787 assert( is_not_dead(n), "can not use dead node");
788 // check various edge cases
789 if ((int)m <= 1) {
790 assert((int)m >= 0, "oob");
791 if (m != 0) add_req(n);
792 return;
793 }
794
795 // Look to see if I can move precedence down one without reallocating
796 if( (_cnt+m) > _max || _in[_max-m] )
797 grow( _max+m );
798
799 // Find a precedence edge to move
800 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
801 uint i;
802 for( i=_cnt; i<_max; i++ )
803 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
804 break; // There must be one, since we grew the array
805 // Slide all the precs over by m positions (assume #prec << m).
806 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
807 }
808
809 // Stuff over the old prec edges
810 for(uint i=0; i<m; i++ ) {
811 _in[_cnt++] = n;
812 }
813
814 // Insert multiple out edges on the node.
815 if (n != NULL && !n->is_top()) {
816 for(uint i=0; i<m; i++ ) {
817 n->add_out((Node *)this);
818 }
819 }
820 }
821
822 //------------------------------del_req----------------------------------------
823 // Delete the required edge and compact the edge array
824 void Node::del_req( uint idx ) {
825 assert( idx < _cnt, "oob");
826 assert( !VerifyHashTableKeys || _hash_lock == 0,
827 "remove node from hash table before modifying it");
828 // First remove corresponding def-use edge
829 Node *n = in(idx);
830 if (n != NULL) n->del_out((Node *)this);
831 _in[idx] = in(--_cnt); // Compact the array
832 // Avoid spec violation: Gap in prec edges.
833 close_prec_gap_at(_cnt);
834 }
835
836 //------------------------------del_req_ordered--------------------------------
837 // Delete the required edge and compact the edge array with preserved order
838 void Node::del_req_ordered( uint idx ) {
839 assert( idx < _cnt, "oob");
840 assert( !VerifyHashTableKeys || _hash_lock == 0,
841 "remove node from hash table before modifying it");
842 // First remove corresponding def-use edge
843 Node *n = in(idx);
844 if (n != NULL) n->del_out((Node *)this);
845 if (idx < --_cnt) { // Not last edge ?
846 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
847 }
848 // Avoid spec violation: Gap in prec edges.
849 close_prec_gap_at(_cnt);
850 }
851
852 //------------------------------ins_req----------------------------------------
853 // Insert a new required input at the end
854 void Node::ins_req( uint idx, Node *n ) {
855 assert( is_not_dead(n), "can not use dead node");
856 add_req(NULL); // Make space
857 assert( idx < _max, "Must have allocated enough space");
858 // Slide over
859 if(_cnt-idx-1 > 0) {
860 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
861 }
862 _in[idx] = n; // Stuff over old required edge
863 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
864 }
865
866 //-----------------------------find_edge---------------------------------------
867 int Node::find_edge(Node* n) {
868 for (uint i = 0; i < len(); i++) {
869 if (_in[i] == n) return i;
870 }
871 return -1;
872 }
873
874 //----------------------------replace_edge-------------------------------------
875 int Node::replace_edge(Node* old, Node* neww) {
876 if (old == neww) return 0; // nothing to do
877 uint nrep = 0;
878 for (uint i = 0; i < len(); i++) {
879 if (in(i) == old) {
880 if (i < req()) {
881 set_req(i, neww);
882 } else {
883 assert(find_prec_edge(neww) == -1, err_msg("spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx));
884 set_prec(i, neww);
885 }
886 nrep++;
887 }
888 }
889 return nrep;
890 }
891
892 /**
893 * Replace input edges in the range pointing to 'old' node.
894 */
895 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
896 if (old == neww) return 0; // nothing to do
897 uint nrep = 0;
898 for (int i = start; i < end; i++) {
899 if (in(i) == old) {
900 set_req(i, neww);
901 nrep++;
902 }
903 }
904 return nrep;
905 }
906
907 //-------------------------disconnect_inputs-----------------------------------
908 // NULL out all inputs to eliminate incoming Def-Use edges.
909 // Return the number of edges between 'n' and 'this'
910 int Node::disconnect_inputs(Node *n, Compile* C) {
911 int edges_to_n = 0;
912
913 uint cnt = req();
914 for( uint i = 0; i < cnt; ++i ) {
915 if( in(i) == 0 ) continue;
916 if( in(i) == n ) ++edges_to_n;
917 set_req(i, NULL);
918 }
919 // Remove precedence edges if any exist
920 // Note: Safepoints may have precedence edges, even during parsing
921 if( (req() != len()) && (in(req()) != NULL) ) {
922 uint max = len();
923 for( uint i = 0; i < max; ++i ) {
924 if( in(i) == 0 ) continue;
925 if( in(i) == n ) ++edges_to_n;
926 set_prec(i, NULL);
927 }
928 }
929
930 // Node::destruct requires all out edges be deleted first
931 // debug_only(destruct();) // no reuse benefit expected
932 if (edges_to_n == 0) {
933 C->record_dead_node(_idx);
934 }
935 return edges_to_n;
936 }
937
938 //-----------------------------uncast---------------------------------------
939 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
940 // Strip away casting. (It is depth-limited.)
941 Node* Node::uncast() const {
942 // Should be inline:
943 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
944 if (is_ConstraintCast() || is_CheckCastPP())
945 return uncast_helper(this);
946 else
947 return (Node*) this;
948 }
949
950 // Find out of current node that matches opcode.
951 Node* Node::find_out_with(int opcode) {
952 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
953 Node* use = fast_out(i);
954 if (use->Opcode() == opcode) {
955 return use;
956 }
957 }
958 return NULL;
959 }
960
961 //---------------------------uncast_helper-------------------------------------
962 Node* Node::uncast_helper(const Node* p) {
963 #ifdef ASSERT
964 uint depth_count = 0;
965 const Node* orig_p = p;
966 #endif
967
968 while (true) {
969 #ifdef ASSERT
970 if (depth_count >= K) {
971 orig_p->dump(4);
972 if (p != orig_p)
973 p->dump(1);
974 }
975 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
976 #endif
977 if (p == NULL || p->req() != 2) {
978 break;
979 } else if (p->is_ConstraintCast()) {
980 p = p->in(1);
981 } else if (p->is_CheckCastPP()) {
982 p = p->in(1);
983 } else {
984 break;
985 }
986 }
987 return (Node*) p;
988 }
989
990 // Return true if the current node has an out that matches opcode.
991 bool Node::has_out_with(int opcode) {
992 return (find_out_with(opcode) != NULL);
993 }
994
995 //------------------------------add_prec---------------------------------------
996 // Add a new precedence input. Precedence inputs are unordered, with
997 // duplicates removed and NULLs packed down at the end.
998 void Node::add_prec( Node *n ) {
999 assert( is_not_dead(n), "can not use dead node");
1000
1001 // Check for NULL at end
1002 if( _cnt >= _max || in(_max-1) )
1003 grow( _max+1 );
1004
1005 // Find a precedence edge to move
1006 uint i = _cnt;
1007 while( in(i) != NULL ) {
1008 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1009 i++;
1010 }
1011 _in[i] = n; // Stuff prec edge over NULL
1012 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
1013
1014 #ifdef ASSERT
1015 while ((++i)<_max) { assert(_in[i] == NULL, err_msg("spec violation: Gap in prec edges (node %d)", _idx)); }
1016 #endif
1017 }
1018
1019 //------------------------------rm_prec----------------------------------------
1020 // Remove a precedence input. Precedence inputs are unordered, with
1021 // duplicates removed and NULLs packed down at the end.
1022 void Node::rm_prec( uint j ) {
1023 assert(j < _max, err_msg("oob: i=%d, _max=%d", j, _max));
1024 assert(j >= _cnt, "not a precedence edge");
1025 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
1026 _in[j]->del_out((Node *)this);
1027 close_prec_gap_at(j);
1028 }
1029
1030 //------------------------------size_of----------------------------------------
1031 uint Node::size_of() const { return sizeof(*this); }
1032
1033 //------------------------------ideal_reg--------------------------------------
1034 uint Node::ideal_reg() const { return 0; }
1035
1036 //------------------------------jvms-------------------------------------------
1037 JVMState* Node::jvms() const { return NULL; }
1038
1039 #ifdef ASSERT
1040 //------------------------------jvms-------------------------------------------
1041 bool Node::verify_jvms(const JVMState* using_jvms) const {
1042 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1043 if (jvms == using_jvms) return true;
1044 }
1045 return false;
1046 }
1047
1048 //------------------------------init_NodeProperty------------------------------
1049 void Node::init_NodeProperty() {
1050 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1051 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
1052 }
1053 #endif
1054
1055 //------------------------------format-----------------------------------------
1056 // Print as assembly
1057 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1058 //------------------------------emit-------------------------------------------
1059 // Emit bytes starting at parameter 'ptr'.
1060 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1061 //------------------------------size-------------------------------------------
1062 // Size of instruction in bytes
1063 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1064
1065 //------------------------------CFG Construction-------------------------------
1066 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1067 // Goto and Return.
1068 const Node *Node::is_block_proj() const { return 0; }
1069
1070 // Minimum guaranteed type
1071 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1072
1073
1074 //------------------------------raise_bottom_type------------------------------
1075 // Get the worst-case Type output for this Node.
1076 void Node::raise_bottom_type(const Type* new_type) {
1077 if (is_Type()) {
1078 TypeNode *n = this->as_Type();
1079 if (VerifyAliases) {
1080 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1081 }
1082 n->set_type(new_type);
1083 } else if (is_Load()) {
1084 LoadNode *n = this->as_Load();
1085 if (VerifyAliases) {
1086 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1087 }
1088 n->set_type(new_type);
1089 }
1090 }
1091
1092 //------------------------------Identity---------------------------------------
1093 // Return a node that the given node is equivalent to.
1094 Node *Node::Identity( PhaseTransform * ) {
1095 return this; // Default to no identities
1096 }
1097
1098 //------------------------------Value------------------------------------------
1099 // Compute a new Type for a node using the Type of the inputs.
1100 const Type *Node::Value( PhaseTransform * ) const {
1101 return bottom_type(); // Default to worst-case Type
1102 }
1103
1104 //------------------------------Ideal------------------------------------------
1105 //
1106 // 'Idealize' the graph rooted at this Node.
1107 //
1108 // In order to be efficient and flexible there are some subtle invariants
1109 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1110 // these invariants, although its too slow to have on by default. If you are
1111 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1112 //
1113 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1114 // pointer. If ANY change is made, it must return the root of the reshaped
1115 // graph - even if the root is the same Node. Example: swapping the inputs
1116 // to an AddINode gives the same answer and same root, but you still have to
1117 // return the 'this' pointer instead of NULL.
1118 //
1119 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1120 // Identity call to return an old Node; basically if Identity can find
1121 // another Node have the Ideal call make no change and return NULL.
1122 // Example: AddINode::Ideal must check for add of zero; in this case it
1123 // returns NULL instead of doing any graph reshaping.
1124 //
1125 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1126 // sharing there may be other users of the old Nodes relying on their current
1127 // semantics. Modifying them will break the other users.
1128 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1129 // "X+3" unchanged in case it is shared.
1130 //
1131 // If you modify the 'this' pointer's inputs, you should use
1132 // 'set_req'. If you are making a new Node (either as the new root or
1133 // some new internal piece) you may use 'init_req' to set the initial
1134 // value. You can make a new Node with either 'new' or 'clone'. In
1135 // either case, def-use info is correctly maintained.
1136 //
1137 // Example: reshape "(X+3)+4" into "X+7":
1138 // set_req(1, in(1)->in(1));
1139 // set_req(2, phase->intcon(7));
1140 // return this;
1141 // Example: reshape "X*4" into "X<<2"
1142 // return new (C) LShiftINode(in(1), phase->intcon(2));
1143 //
1144 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1145 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1146 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1147 // return new (C) AddINode(shift, in(1));
1148 //
1149 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1150 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1151 // The Right Thing with def-use info.
1152 //
1153 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1154 // graph uses the 'this' Node it must be the root. If you want a Node with
1155 // the same Opcode as the 'this' pointer use 'clone'.
1156 //
1157 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1158 return NULL; // Default to being Ideal already
1159 }
1160
1161 // Some nodes have specific Ideal subgraph transformations only if they are
1162 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1163 // for the transformations to happen.
1164 bool Node::has_special_unique_user() const {
1165 assert(outcnt() == 1, "match only for unique out");
1166 Node* n = unique_out();
1167 int op = Opcode();
1168 if( this->is_Store() ) {
1169 // Condition for back-to-back stores folding.
1170 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1171 } else if (this->is_Load() || this->is_DecodeN()) {
1172 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1173 return n->Opcode() == Op_MemBarAcquire;
1174 } else if( op == Op_AddL ) {
1175 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1176 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1177 } else if( op == Op_SubI || op == Op_SubL ) {
1178 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1179 return n->Opcode() == op && n->in(2) == this;
1180 }
1181 return false;
1182 };
1183
1184 //--------------------------find_exact_control---------------------------------
1185 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1186 Node* Node::find_exact_control(Node* ctrl) {
1187 if (ctrl == NULL && this->is_Region())
1188 ctrl = this->as_Region()->is_copy();
1189
1190 if (ctrl != NULL && ctrl->is_CatchProj()) {
1191 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1192 ctrl = ctrl->in(0);
1193 if (ctrl != NULL && !ctrl->is_top())
1194 ctrl = ctrl->in(0);
1195 }
1196
1197 if (ctrl != NULL && ctrl->is_Proj())
1198 ctrl = ctrl->in(0);
1199
1200 return ctrl;
1201 }
1202
1203 //--------------------------dominates------------------------------------------
1204 // Helper function for MemNode::all_controls_dominate().
1205 // Check if 'this' control node dominates or equal to 'sub' control node.
1206 // We already know that if any path back to Root or Start reaches 'this',
1207 // then all paths so, so this is a simple search for one example,
1208 // not an exhaustive search for a counterexample.
1209 bool Node::dominates(Node* sub, Node_List &nlist) {
1210 assert(this->is_CFG(), "expecting control");
1211 assert(sub != NULL && sub->is_CFG(), "expecting control");
1212
1213 // detect dead cycle without regions
1214 int iterations_without_region_limit = DominatorSearchLimit;
1215
1216 Node* orig_sub = sub;
1217 Node* dom = this;
1218 bool met_dom = false;
1219 nlist.clear();
1220
1221 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1222 // After seeing 'dom', continue up to Root or Start.
1223 // If we hit a region (backward split point), it may be a loop head.
1224 // Keep going through one of the region's inputs. If we reach the
1225 // same region again, go through a different input. Eventually we
1226 // will either exit through the loop head, or give up.
1227 // (If we get confused, break out and return a conservative 'false'.)
1228 while (sub != NULL) {
1229 if (sub->is_top()) break; // Conservative answer for dead code.
1230 if (sub == dom) {
1231 if (nlist.size() == 0) {
1232 // No Region nodes except loops were visited before and the EntryControl
1233 // path was taken for loops: it did not walk in a cycle.
1234 return true;
1235 } else if (met_dom) {
1236 break; // already met before: walk in a cycle
1237 } else {
1238 // Region nodes were visited. Continue walk up to Start or Root
1239 // to make sure that it did not walk in a cycle.
1240 met_dom = true; // first time meet
1241 iterations_without_region_limit = DominatorSearchLimit; // Reset
1242 }
1243 }
1244 if (sub->is_Start() || sub->is_Root()) {
1245 // Success if we met 'dom' along a path to Start or Root.
1246 // We assume there are no alternative paths that avoid 'dom'.
1247 // (This assumption is up to the caller to ensure!)
1248 return met_dom;
1249 }
1250 Node* up = sub->in(0);
1251 // Normalize simple pass-through regions and projections:
1252 up = sub->find_exact_control(up);
1253 // If sub == up, we found a self-loop. Try to push past it.
1254 if (sub == up && sub->is_Loop()) {
1255 // Take loop entry path on the way up to 'dom'.
1256 up = sub->in(1); // in(LoopNode::EntryControl);
1257 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1258 // Always take in(1) path on the way up to 'dom' for clone regions
1259 // (with only one input) or regions which merge > 2 paths
1260 // (usually used to merge fast/slow paths).
1261 up = sub->in(1);
1262 } else if (sub == up && sub->is_Region()) {
1263 // Try both paths for Regions with 2 input paths (it may be a loop head).
1264 // It could give conservative 'false' answer without information
1265 // which region's input is the entry path.
1266 iterations_without_region_limit = DominatorSearchLimit; // Reset
1267
1268 bool region_was_visited_before = false;
1269 // Was this Region node visited before?
1270 // If so, we have reached it because we accidentally took a
1271 // loop-back edge from 'sub' back into the body of the loop,
1272 // and worked our way up again to the loop header 'sub'.
1273 // So, take the first unexplored path on the way up to 'dom'.
1274 for (int j = nlist.size() - 1; j >= 0; j--) {
1275 intptr_t ni = (intptr_t)nlist.at(j);
1276 Node* visited = (Node*)(ni & ~1);
1277 bool visited_twice_already = ((ni & 1) != 0);
1278 if (visited == sub) {
1279 if (visited_twice_already) {
1280 // Visited 2 paths, but still stuck in loop body. Give up.
1281 return false;
1282 }
1283 // The Region node was visited before only once.
1284 // (We will repush with the low bit set, below.)
1285 nlist.remove(j);
1286 // We will find a new edge and re-insert.
1287 region_was_visited_before = true;
1288 break;
1289 }
1290 }
1291
1292 // Find an incoming edge which has not been seen yet; walk through it.
1293 assert(up == sub, "");
1294 uint skip = region_was_visited_before ? 1 : 0;
1295 for (uint i = 1; i < sub->req(); i++) {
1296 Node* in = sub->in(i);
1297 if (in != NULL && !in->is_top() && in != sub) {
1298 if (skip == 0) {
1299 up = in;
1300 break;
1301 }
1302 --skip; // skip this nontrivial input
1303 }
1304 }
1305
1306 // Set 0 bit to indicate that both paths were taken.
1307 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1308 }
1309
1310 if (up == sub) {
1311 break; // some kind of tight cycle
1312 }
1313 if (up == orig_sub && met_dom) {
1314 // returned back after visiting 'dom'
1315 break; // some kind of cycle
1316 }
1317 if (--iterations_without_region_limit < 0) {
1318 break; // dead cycle
1319 }
1320 sub = up;
1321 }
1322
1323 // Did not meet Root or Start node in pred. chain.
1324 // Conservative answer for dead code.
1325 return false;
1326 }
1327
1328 //------------------------------remove_dead_region-----------------------------
1329 // This control node is dead. Follow the subgraph below it making everything
1330 // using it dead as well. This will happen normally via the usual IterGVN
1331 // worklist but this call is more efficient. Do not update use-def info
1332 // inside the dead region, just at the borders.
1333 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1334 // Con's are a popular node to re-hit in the hash table again.
1335 if( dead->is_Con() ) return;
1336
1337 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1338 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1339 Node_List nstack(Thread::current()->resource_area());
1340
1341 Node *top = igvn->C->top();
1342 nstack.push(dead);
1343 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1344
1345 while (nstack.size() > 0) {
1346 dead = nstack.pop();
1347 if (dead->Opcode() == Op_SafePoint) {
1348 dead->as_SafePoint()->disconnect_from_root(igvn);
1349 }
1350 if (dead->outcnt() > 0) {
1351 // Keep dead node on stack until all uses are processed.
1352 nstack.push(dead);
1353 // For all Users of the Dead... ;-)
1354 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1355 Node* use = dead->last_out(k);
1356 igvn->hash_delete(use); // Yank from hash table prior to mod
1357 if (use->in(0) == dead) { // Found another dead node
1358 assert (!use->is_Con(), "Control for Con node should be Root node.");
1359 use->set_req(0, top); // Cut dead edge to prevent processing
1360 nstack.push(use); // the dead node again.
1361 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1362 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1363 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1364 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1365 use->set_req(0, top); // Cut self edge
1366 nstack.push(use);
1367 } else { // Else found a not-dead user
1368 // Dead if all inputs are top or null
1369 bool dead_use = !use->is_Root(); // Keep empty graph alive
1370 for (uint j = 1; j < use->req(); j++) {
1371 Node* in = use->in(j);
1372 if (in == dead) { // Turn all dead inputs into TOP
1373 use->set_req(j, top);
1374 } else if (in != NULL && !in->is_top()) {
1375 dead_use = false;
1376 }
1377 }
1378 if (dead_use) {
1379 if (use->is_Region()) {
1380 use->set_req(0, top); // Cut self edge
1381 }
1382 nstack.push(use);
1383 } else {
1384 igvn->_worklist.push(use);
1385 }
1386 }
1387 // Refresh the iterator, since any number of kills might have happened.
1388 k = dead->last_outs(kmin);
1389 }
1390 } else { // (dead->outcnt() == 0)
1391 // Done with outputs.
1392 igvn->hash_delete(dead);
1393 igvn->_worklist.remove(dead);
1394 igvn->set_type(dead, Type::TOP);
1395 if (dead->is_macro()) {
1396 igvn->C->remove_macro_node(dead);
1397 }
1398 if (dead->is_expensive()) {
1399 igvn->C->remove_expensive_node(dead);
1400 }
1401 if (dead->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
1402 igvn->C->remove_shenandoah_barrier(reinterpret_cast<ShenandoahLoadReferenceBarrierNode*>(dead));
1403 }
1404 CastIINode* cast = dead->isa_CastII();
1405 if (cast != NULL && cast->has_range_check()) {
1406 igvn->C->remove_range_check_cast(cast);
1407 }
1408 igvn->C->record_dead_node(dead->_idx);
1409 // Kill all inputs to the dead guy
1410 for (uint i=0; i < dead->req(); i++) {
1411 Node *n = dead->in(i); // Get input to dead guy
1412 if (n != NULL && !n->is_top()) { // Input is valid?
1413 dead->set_req(i, top); // Smash input away
1414 if (n->outcnt() == 0) { // Input also goes dead?
1415 if (!n->is_Con())
1416 nstack.push(n); // Clear it out as well
1417 } else if (n->outcnt() == 1 &&
1418 n->has_special_unique_user()) {
1419 igvn->add_users_to_worklist( n );
1420 } else if (n->outcnt() <= 2 && n->is_Store()) {
1421 // Push store's uses on worklist to enable folding optimization for
1422 // store/store and store/load to the same address.
1423 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1424 // and remove_globally_dead_node().
1425 igvn->add_users_to_worklist( n );
1426 } else if (n->Opcode() == Op_AddP && CallLeafNode::has_only_g1_wb_pre_uses(n)) {
1427 igvn->add_users_to_worklist(n);
1428 }
1429 }
1430 }
1431 } // (dead->outcnt() == 0)
1432 } // while (nstack.size() > 0) for outputs
1433 return;
1434 }
1435
1436 //------------------------------remove_dead_region-----------------------------
1437 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1438 Node *n = in(0);
1439 if( !n ) return false;
1440 // Lost control into this guy? I.e., it became unreachable?
1441 // Aggressively kill all unreachable code.
1442 if (can_reshape && n->is_top()) {
1443 kill_dead_code(this, phase->is_IterGVN());
1444 return false; // Node is dead.
1445 }
1446
1447 if( n->is_Region() && n->as_Region()->is_copy() ) {
1448 Node *m = n->nonnull_req();
1449 set_req(0, m);
1450 return true;
1451 }
1452 return false;
1453 }
1454
1455 //------------------------------hash-------------------------------------------
1456 // Hash function over Nodes.
1457 uint Node::hash() const {
1458 uint sum = 0;
1459 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1460 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1461 return (sum>>2) + _cnt + Opcode();
1462 }
1463
1464 //------------------------------cmp--------------------------------------------
1465 // Compare special parts of simple Nodes
1466 uint Node::cmp( const Node &n ) const {
1467 return 1; // Must be same
1468 }
1469
1470 //------------------------------rematerialize-----------------------------------
1471 // Should we clone rather than spill this instruction?
1472 bool Node::rematerialize() const {
1473 if ( is_Mach() )
1474 return this->as_Mach()->rematerialize();
1475 else
1476 return (_flags & Flag_rematerialize) != 0;
1477 }
1478
1479 //------------------------------needs_anti_dependence_check---------------------
1480 // Nodes which use memory without consuming it, hence need antidependences.
1481 bool Node::needs_anti_dependence_check() const {
1482 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1483 return false;
1484 else
1485 return in(1)->bottom_type()->has_memory();
1486 }
1487
1488
1489 // Get an integer constant from a ConNode (or CastIINode).
1490 // Return a default value if there is no apparent constant here.
1491 const TypeInt* Node::find_int_type() const {
1492 if (this->is_Type()) {
1493 return this->as_Type()->type()->isa_int();
1494 } else if (this->is_Con()) {
1495 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1496 return this->bottom_type()->isa_int();
1497 }
1498 return NULL;
1499 }
1500
1501 // Get a pointer constant from a ConstNode.
1502 // Returns the constant if it is a pointer ConstNode
1503 intptr_t Node::get_ptr() const {
1504 assert( Opcode() == Op_ConP, "" );
1505 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1506 }
1507
1508 // Get a narrow oop constant from a ConNNode.
1509 intptr_t Node::get_narrowcon() const {
1510 assert( Opcode() == Op_ConN, "" );
1511 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1512 }
1513
1514 // Get a long constant from a ConNode.
1515 // Return a default value if there is no apparent constant here.
1516 const TypeLong* Node::find_long_type() const {
1517 if (this->is_Type()) {
1518 return this->as_Type()->type()->isa_long();
1519 } else if (this->is_Con()) {
1520 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1521 return this->bottom_type()->isa_long();
1522 }
1523 return NULL;
1524 }
1525
1526
1527 /**
1528 * Return a ptr type for nodes which should have it.
1529 */
1530 const TypePtr* Node::get_ptr_type() const {
1531 const TypePtr* tp = this->bottom_type()->make_ptr();
1532 #ifdef ASSERT
1533 if (tp == NULL) {
1534 this->dump(1);
1535 assert((tp != NULL), "unexpected node type");
1536 }
1537 #endif
1538 return tp;
1539 }
1540
1541 // Get a double constant from a ConstNode.
1542 // Returns the constant if it is a double ConstNode
1543 jdouble Node::getd() const {
1544 assert( Opcode() == Op_ConD, "" );
1545 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1546 }
1547
1548 // Get a float constant from a ConstNode.
1549 // Returns the constant if it is a float ConstNode
1550 jfloat Node::getf() const {
1551 assert( Opcode() == Op_ConF, "" );
1552 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1553 }
1554
1555 #ifndef PRODUCT
1556
1557 //----------------------------NotANode----------------------------------------
1558 // Used in debugging code to avoid walking across dead or uninitialized edges.
1559 static inline bool NotANode(const Node* n) {
1560 if (n == NULL) return true;
1561 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1562 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1563 return false;
1564 }
1565
1566
1567 //------------------------------find------------------------------------------
1568 // Find a neighbor of this Node with the given _idx
1569 // If idx is negative, find its absolute value, following both _in and _out.
1570 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1571 VectorSet* old_space, VectorSet* new_space ) {
1572 int node_idx = (idx >= 0) ? idx : -idx;
1573 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1574 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1575 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1576 if( v->test(n->_idx) ) return;
1577 if( (int)n->_idx == node_idx
1578 debug_only(|| n->debug_idx() == node_idx) ) {
1579 if (result != NULL)
1580 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1581 (uintptr_t)result, (uintptr_t)n, node_idx);
1582 result = n;
1583 }
1584 v->set(n->_idx);
1585 for( uint i=0; i<n->len(); i++ ) {
1586 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1587 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1588 }
1589 // Search along forward edges also:
1590 if (idx < 0 && !only_ctrl) {
1591 for( uint j=0; j<n->outcnt(); j++ ) {
1592 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1593 }
1594 }
1595 #ifdef ASSERT
1596 // Search along debug_orig edges last, checking for cycles
1597 Node* orig = n->debug_orig();
1598 if (orig != NULL) {
1599 do {
1600 if (NotANode(orig)) break;
1601 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1602 orig = orig->debug_orig();
1603 } while (orig != NULL && orig != n->debug_orig());
1604 }
1605 #endif //ASSERT
1606 }
1607
1608 // call this from debugger:
1609 Node* find_node(Node* n, int idx) {
1610 return n->find(idx);
1611 }
1612
1613 //------------------------------find-------------------------------------------
1614 Node* Node::find(int idx) const {
1615 ResourceArea *area = Thread::current()->resource_area();
1616 VectorSet old_space(area), new_space(area);
1617 Node* result = NULL;
1618 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1619 return result;
1620 }
1621
1622 //------------------------------find_ctrl--------------------------------------
1623 // Find an ancestor to this node in the control history with given _idx
1624 Node* Node::find_ctrl(int idx) const {
1625 ResourceArea *area = Thread::current()->resource_area();
1626 VectorSet old_space(area), new_space(area);
1627 Node* result = NULL;
1628 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1629 return result;
1630 }
1631 #endif
1632
1633
1634
1635 #ifndef PRODUCT
1636
1637 // -----------------------------Name-------------------------------------------
1638 extern const char *NodeClassNames[];
1639 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1640
1641 static bool is_disconnected(const Node* n) {
1642 for (uint i = 0; i < n->req(); i++) {
1643 if (n->in(i) != NULL) return false;
1644 }
1645 return true;
1646 }
1647
1648 #ifdef ASSERT
1649 static void dump_orig(Node* orig, outputStream *st) {
1650 Compile* C = Compile::current();
1651 if (NotANode(orig)) orig = NULL;
1652 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1653 if (orig == NULL) return;
1654 st->print(" !orig=");
1655 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1656 if (NotANode(fast)) fast = NULL;
1657 while (orig != NULL) {
1658 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1659 if (discon) st->print("[");
1660 if (!Compile::current()->node_arena()->contains(orig))
1661 st->print("o");
1662 st->print("%d", orig->_idx);
1663 if (discon) st->print("]");
1664 orig = orig->debug_orig();
1665 if (NotANode(orig)) orig = NULL;
1666 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1667 if (orig != NULL) st->print(",");
1668 if (fast != NULL) {
1669 // Step fast twice for each single step of orig:
1670 fast = fast->debug_orig();
1671 if (NotANode(fast)) fast = NULL;
1672 if (fast != NULL && fast != orig) {
1673 fast = fast->debug_orig();
1674 if (NotANode(fast)) fast = NULL;
1675 }
1676 if (fast == orig) {
1677 st->print("...");
1678 break;
1679 }
1680 }
1681 }
1682 }
1683
1684 void Node::set_debug_orig(Node* orig) {
1685 _debug_orig = orig;
1686 if (BreakAtNode == 0) return;
1687 if (NotANode(orig)) orig = NULL;
1688 int trip = 10;
1689 while (orig != NULL) {
1690 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1691 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1692 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1693 BREAKPOINT;
1694 }
1695 orig = orig->debug_orig();
1696 if (NotANode(orig)) orig = NULL;
1697 if (trip-- <= 0) break;
1698 }
1699 }
1700 #endif //ASSERT
1701
1702 //------------------------------dump------------------------------------------
1703 // Dump a Node
1704 void Node::dump(const char* suffix, outputStream *st) const {
1705 Compile* C = Compile::current();
1706 bool is_new = C->node_arena()->contains(this);
1707 C->_in_dump_cnt++;
1708 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1709
1710 // Dump the required and precedence inputs
1711 dump_req(st);
1712 dump_prec(st);
1713 // Dump the outputs
1714 dump_out(st);
1715
1716 if (is_disconnected(this)) {
1717 #ifdef ASSERT
1718 st->print(" [%d]",debug_idx());
1719 dump_orig(debug_orig(), st);
1720 #endif
1721 st->cr();
1722 C->_in_dump_cnt--;
1723 return; // don't process dead nodes
1724 }
1725
1726 // Dump node-specific info
1727 dump_spec(st);
1728 #ifdef ASSERT
1729 // Dump the non-reset _debug_idx
1730 if (Verbose && WizardMode) {
1731 st->print(" [%d]",debug_idx());
1732 }
1733 #endif
1734
1735 const Type *t = bottom_type();
1736
1737 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1738 const TypeInstPtr *toop = t->isa_instptr();
1739 const TypeKlassPtr *tkls = t->isa_klassptr();
1740 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1741 if (klass && klass->is_loaded() && klass->is_interface()) {
1742 st->print(" Interface:");
1743 } else if (toop) {
1744 st->print(" Oop:");
1745 } else if (tkls) {
1746 st->print(" Klass:");
1747 }
1748 t->dump_on(st);
1749 } else if (t == Type::MEMORY) {
1750 st->print(" Memory:");
1751 MemNode::dump_adr_type(this, adr_type(), st);
1752 } else if (Verbose || WizardMode) {
1753 st->print(" Type:");
1754 if (t) {
1755 t->dump_on(st);
1756 } else {
1757 st->print("no type");
1758 }
1759 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1760 // Dump MachSpillcopy vector type.
1761 t->dump_on(st);
1762 }
1763 if (is_new) {
1764 debug_only(dump_orig(debug_orig(), st));
1765 Node_Notes* nn = C->node_notes_at(_idx);
1766 if (nn != NULL && !nn->is_clear()) {
1767 if (nn->jvms() != NULL) {
1768 st->print(" !jvms:");
1769 nn->jvms()->dump_spec(st);
1770 }
1771 }
1772 }
1773 if (suffix) st->print("%s", suffix);
1774 C->_in_dump_cnt--;
1775 }
1776
1777 //------------------------------dump_req--------------------------------------
1778 void Node::dump_req(outputStream *st) const {
1779 // Dump the required input edges
1780 for (uint i = 0; i < req(); i++) { // For all required inputs
1781 Node* d = in(i);
1782 if (d == NULL) {
1783 st->print("_ ");
1784 } else if (NotANode(d)) {
1785 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1786 } else {
1787 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1788 }
1789 }
1790 }
1791
1792
1793 //------------------------------dump_prec-------------------------------------
1794 void Node::dump_prec(outputStream *st) const {
1795 // Dump the precedence edges
1796 int any_prec = 0;
1797 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1798 Node* p = in(i);
1799 if (p != NULL) {
1800 if (!any_prec++) st->print(" |");
1801 if (NotANode(p)) { st->print("NotANode "); continue; }
1802 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1803 }
1804 }
1805 }
1806
1807 //------------------------------dump_out--------------------------------------
1808 void Node::dump_out(outputStream *st) const {
1809 // Delimit the output edges
1810 st->print(" [[");
1811 // Dump the output edges
1812 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1813 Node* u = _out[i];
1814 if (u == NULL) {
1815 st->print("_ ");
1816 } else if (NotANode(u)) {
1817 st->print("NotANode ");
1818 } else {
1819 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1820 }
1821 }
1822 st->print("]] ");
1823 }
1824
1825 //------------------------------dump_nodes-------------------------------------
1826 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1827 Node* s = (Node*)start; // remove const
1828 if (NotANode(s)) return;
1829
1830 uint depth = (uint)ABS(d);
1831 int direction = d;
1832 Compile* C = Compile::current();
1833 GrowableArray <Node *> nstack(C->live_nodes());
1834
1835 nstack.append(s);
1836 int begin = 0;
1837 int end = 0;
1838 for(uint i = 0; i < depth; i++) {
1839 end = nstack.length();
1840 for(int j = begin; j < end; j++) {
1841 Node* tp = nstack.at(j);
1842 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1843 for(uint k = 0; k < limit; k++) {
1844 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1845
1846 if (NotANode(n)) continue;
1847 // do not recurse through top or the root (would reach unrelated stuff)
1848 if (n->is_Root() || n->is_top()) continue;
1849 if (only_ctrl && !n->is_CFG()) continue;
1850
1851 bool on_stack = nstack.contains(n);
1852 if (!on_stack) {
1853 nstack.append(n);
1854 }
1855 }
1856 }
1857 begin = end;
1858 }
1859 end = nstack.length();
1860 if (direction > 0) {
1861 for(int j = end-1; j >= 0; j--) {
1862 nstack.at(j)->dump();
1863 }
1864 } else {
1865 for(int j = 0; j < end; j++) {
1866 nstack.at(j)->dump();
1867 }
1868 }
1869 }
1870
1871 //------------------------------dump-------------------------------------------
1872 void Node::dump(int d) const {
1873 dump_nodes(this, d, false);
1874 }
1875
1876 //------------------------------dump_ctrl--------------------------------------
1877 // Dump a Node's control history to depth
1878 void Node::dump_ctrl(int d) const {
1879 dump_nodes(this, d, true);
1880 }
1881
1882 // VERIFICATION CODE
1883 // For each input edge to a node (ie - for each Use-Def edge), verify that
1884 // there is a corresponding Def-Use edge.
1885 //------------------------------verify_edges-----------------------------------
1886 void Node::verify_edges(Unique_Node_List &visited) {
1887 uint i, j, idx;
1888 int cnt;
1889 Node *n;
1890
1891 // Recursive termination test
1892 if (visited.member(this)) return;
1893 visited.push(this);
1894
1895 // Walk over all input edges, checking for correspondence
1896 for( i = 0; i < len(); i++ ) {
1897 n = in(i);
1898 if (n != NULL && !n->is_top()) {
1899 // Count instances of (Node *)this
1900 cnt = 0;
1901 for (idx = 0; idx < n->_outcnt; idx++ ) {
1902 if (n->_out[idx] == (Node *)this) cnt++;
1903 }
1904 assert( cnt > 0,"Failed to find Def-Use edge." );
1905 // Check for duplicate edges
1906 // walk the input array downcounting the input edges to n
1907 for( j = 0; j < len(); j++ ) {
1908 if( in(j) == n ) cnt--;
1909 }
1910 assert( cnt == 0,"Mismatched edge count.");
1911 } else if (n == NULL) {
1912 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1913 } else {
1914 assert(n->is_top(), "sanity");
1915 // Nothing to check.
1916 }
1917 }
1918 // Recursive walk over all input edges
1919 for( i = 0; i < len(); i++ ) {
1920 n = in(i);
1921 if( n != NULL )
1922 in(i)->verify_edges(visited);
1923 }
1924 }
1925
1926 //------------------------------verify_recur-----------------------------------
1927 static const Node *unique_top = NULL;
1928
1929 void Node::verify_recur(const Node *n, int verify_depth,
1930 VectorSet &old_space, VectorSet &new_space) {
1931 if ( verify_depth == 0 ) return;
1932 if (verify_depth > 0) --verify_depth;
1933
1934 Compile* C = Compile::current();
1935
1936 // Contained in new_space or old_space?
1937 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1938 // Check for visited in the proper space. Numberings are not unique
1939 // across spaces so we need a separate VectorSet for each space.
1940 if( v->test_set(n->_idx) ) return;
1941
1942 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1943 if (C->cached_top_node() == NULL)
1944 C->set_cached_top_node((Node*)n);
1945 assert(C->cached_top_node() == n, "TOP node must be unique");
1946 }
1947
1948 for( uint i = 0; i < n->len(); i++ ) {
1949 Node *x = n->in(i);
1950 if (!x || x->is_top()) continue;
1951
1952 // Verify my input has a def-use edge to me
1953 if (true /*VerifyDefUse*/) {
1954 // Count use-def edges from n to x
1955 int cnt = 0;
1956 for( uint j = 0; j < n->len(); j++ )
1957 if( n->in(j) == x )
1958 cnt++;
1959 // Count def-use edges from x to n
1960 uint max = x->_outcnt;
1961 for( uint k = 0; k < max; k++ )
1962 if (x->_out[k] == n)
1963 cnt--;
1964 assert( cnt == 0, "mismatched def-use edge counts" );
1965 }
1966
1967 verify_recur(x, verify_depth, old_space, new_space);
1968 }
1969
1970 }
1971
1972 //------------------------------verify-----------------------------------------
1973 // Check Def-Use info for my subgraph
1974 void Node::verify() const {
1975 Compile* C = Compile::current();
1976 Node* old_top = C->cached_top_node();
1977 ResourceMark rm;
1978 ResourceArea *area = Thread::current()->resource_area();
1979 VectorSet old_space(area), new_space(area);
1980 verify_recur(this, -1, old_space, new_space);
1981 C->set_cached_top_node(old_top);
1982 }
1983 #endif
1984
1985
1986 //------------------------------walk-------------------------------------------
1987 // Graph walk, with both pre-order and post-order functions
1988 void Node::walk(NFunc pre, NFunc post, void *env) {
1989 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1990 walk_(pre, post, env, visited);
1991 }
1992
1993 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1994 if( visited.test_set(_idx) ) return;
1995 pre(*this,env); // Call the pre-order walk function
1996 for( uint i=0; i<_max; i++ )
1997 if( in(i) ) // Input exists and is not walked?
1998 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1999 post(*this,env); // Call the post-order walk function
2000 }
2001
2002 void Node::nop(Node &, void*) {}
2003
2004 //------------------------------Registers--------------------------------------
2005 // Do we Match on this edge index or not? Generally false for Control
2006 // and true for everything else. Weird for calls & returns.
2007 uint Node::match_edge(uint idx) const {
2008 return idx; // True for other than index 0 (control)
2009 }
2010
2011 static RegMask _not_used_at_all;
2012 // Register classes are defined for specific machines
2013 const RegMask &Node::out_RegMask() const {
2014 ShouldNotCallThis();
2015 return _not_used_at_all;
2016 }
2017
2018 const RegMask &Node::in_RegMask(uint) const {
2019 ShouldNotCallThis();
2020 return _not_used_at_all;
2021 }
2022
2023 //=============================================================================
2024 //-----------------------------------------------------------------------------
2025 void Node_Array::reset( Arena *new_arena ) {
2026 _a->Afree(_nodes,_max*sizeof(Node*));
2027 _max = 0;
2028 _nodes = NULL;
2029 _a = new_arena;
2030 }
2031
2032 //------------------------------clear------------------------------------------
2033 // Clear all entries in _nodes to NULL but keep storage
2034 void Node_Array::clear() {
2035 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2036 }
2037
2038 //-----------------------------------------------------------------------------
2039 void Node_Array::grow( uint i ) {
2040 if( !_max ) {
2041 _max = 1;
2042 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2043 _nodes[0] = NULL;
2044 }
2045 uint old = _max;
2046 while( i >= _max ) _max <<= 1; // Double to fit
2047 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2048 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2049 }
2050
2051 //-----------------------------------------------------------------------------
2052 void Node_Array::insert( uint i, Node *n ) {
2053 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2054 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2055 _nodes[i] = n;
2056 }
2057
2058 //-----------------------------------------------------------------------------
2059 void Node_Array::remove( uint i ) {
2060 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2061 _nodes[_max-1] = NULL;
2062 }
2063
2064 //-----------------------------------------------------------------------------
2065 void Node_Array::sort( C_sort_func_t func) {
2066 qsort( _nodes, _max, sizeof( Node* ), func );
2067 }
2068
2069 //-----------------------------------------------------------------------------
2070 void Node_Array::dump() const {
2071 #ifndef PRODUCT
2072 for( uint i = 0; i < _max; i++ ) {
2073 Node *nn = _nodes[i];
2074 if( nn != NULL ) {
2075 tty->print("%5d--> ",i); nn->dump();
2076 }
2077 }
2078 #endif
2079 }
2080
2081 //--------------------------is_iteratively_computed------------------------------
2082 // Operation appears to be iteratively computed (such as an induction variable)
2083 // It is possible for this operation to return false for a loop-varying
2084 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2085 bool Node::is_iteratively_computed() {
2086 if (ideal_reg()) { // does operation have a result register?
2087 for (uint i = 1; i < req(); i++) {
2088 Node* n = in(i);
2089 if (n != NULL && n->is_Phi()) {
2090 for (uint j = 1; j < n->req(); j++) {
2091 if (n->in(j) == this) {
2092 return true;
2093 }
2094 }
2095 }
2096 }
2097 }
2098 return false;
2099 }
2100
2101 //--------------------------find_similar------------------------------
2102 // Return a node with opcode "opc" and same inputs as "this" if one can
2103 // be found; Otherwise return NULL;
2104 Node* Node::find_similar(int opc) {
2105 if (req() >= 2) {
2106 Node* def = in(1);
2107 if (def && def->outcnt() >= 2) {
2108 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2109 Node* use = def->fast_out(i);
2110 if (use->Opcode() == opc &&
2111 use->req() == req()) {
2112 uint j;
2113 for (j = 0; j < use->req(); j++) {
2114 if (use->in(j) != in(j)) {
2115 break;
2116 }
2117 }
2118 if (j == use->req()) {
2119 return use;
2120 }
2121 }
2122 }
2123 }
2124 }
2125 return NULL;
2126 }
2127
2128
2129 //--------------------------unique_ctrl_out------------------------------
2130 // Return the unique control out if only one. Null if none or more than one.
2131 Node* Node::unique_ctrl_out() {
2132 Node* found = NULL;
2133 for (uint i = 0; i < outcnt(); i++) {
2134 Node* use = raw_out(i);
2135 if (use->is_CFG() && use != this) {
2136 if (found != NULL) return NULL;
2137 found = use;
2138 }
2139 }
2140 return found;
2141 }
2142
2143 void Node::ensure_control_or_add_prec(Node* c) {
2144 if (in(0) == NULL) {
2145 set_req(0, c);
2146 } else if (in(0) != c) {
2147 add_prec(c);
2148 }
2149 }
2150
2151 //=============================================================================
2152 //------------------------------yank-------------------------------------------
2153 // Find and remove
2154 void Node_List::yank( Node *n ) {
2155 uint i;
2156 for( i = 0; i < _cnt; i++ )
2157 if( _nodes[i] == n )
2158 break;
2159
2160 if( i < _cnt )
2161 _nodes[i] = _nodes[--_cnt];
2162 }
2163
2164 //------------------------------dump-------------------------------------------
2165 void Node_List::dump() const {
2166 #ifndef PRODUCT
2167 for( uint i = 0; i < _cnt; i++ )
2168 if( _nodes[i] ) {
2169 tty->print("%5d--> ",i);
2170 _nodes[i]->dump();
2171 }
2172 #endif
2173 }
2174
2175 void Node_List::dump_simple() const {
2176 #ifndef PRODUCT
2177 for( uint i = 0; i < _cnt; i++ )
2178 if( _nodes[i] ) {
2179 tty->print(" %d", _nodes[i]->_idx);
2180 } else {
2181 tty->print(" NULL");
2182 }
2183 #endif
2184 }
2185
2186 //=============================================================================
2187 //------------------------------remove-----------------------------------------
2188 void Unique_Node_List::remove( Node *n ) {
2189 if( _in_worklist[n->_idx] ) {
2190 for( uint i = 0; i < size(); i++ )
2191 if( _nodes[i] == n ) {
2192 map(i,Node_List::pop());
2193 _in_worklist >>= n->_idx;
2194 return;
2195 }
2196 ShouldNotReachHere();
2197 }
2198 }
2199
2200 //-----------------------remove_useless_nodes----------------------------------
2201 // Remove useless nodes from worklist
2202 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2203
2204 for( uint i = 0; i < size(); ++i ) {
2205 Node *n = at(i);
2206 assert( n != NULL, "Did not expect null entries in worklist");
2207 if( ! useful.test(n->_idx) ) {
2208 _in_worklist >>= n->_idx;
2209 map(i,Node_List::pop());
2210 // Node *replacement = Node_List::pop();
2211 // if( i != size() ) { // Check if removing last entry
2212 // _nodes[i] = replacement;
2213 // }
2214 --i; // Visit popped node
2215 // If it was last entry, loop terminates since size() was also reduced
2216 }
2217 }
2218 }
2219
2220 //=============================================================================
2221 void Node_Stack::grow() {
2222 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2223 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2224 size_t max = old_max << 1; // max * 2
2225 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2226 _inode_max = _inodes + max;
2227 _inode_top = _inodes + old_top; // restore _top
2228 }
2229
2230 // Node_Stack is used to map nodes.
2231 Node* Node_Stack::find(uint idx) const {
2232 uint sz = size();
2233 for (uint i=0; i < sz; i++) {
2234 if (idx == index_at(i) )
2235 return node_at(i);
2236 }
2237 return NULL;
2238 }
2239
2240 //=============================================================================
2241 uint TypeNode::size_of() const { return sizeof(*this); }
2242 #ifndef PRODUCT
2243 void TypeNode::dump_spec(outputStream *st) const {
2244 if( !Verbose && !WizardMode ) {
2245 // standard dump does this in Verbose and WizardMode
2246 st->print(" #"); _type->dump_on(st);
2247 }
2248 }
2249 #endif
2250 uint TypeNode::hash() const {
2251 return Node::hash() + _type->hash();
2252 }
2253 uint TypeNode::cmp( const Node &n ) const
2254 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2255 const Type *TypeNode::bottom_type() const { return _type; }
2256 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2257
2258 //------------------------------ideal_reg--------------------------------------
2259 uint TypeNode::ideal_reg() const {
2260 return _type->ideal_reg();
2261 }