1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/ad.hpp"
32 #include "opto/callGenerator.hpp"
33 #include "opto/castnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/connode.hpp"
36 #include "opto/inlinetypenode.hpp"
37 #include "opto/loopnode.hpp"
38 #include "opto/machnode.hpp"
39 #include "opto/matcher.hpp"
40 #include "opto/node.hpp"
41 #include "opto/opcodes.hpp"
42 #include "opto/regmask.hpp"
43 #include "opto/rootnode.hpp"
44 #include "opto/type.hpp"
45 #include "utilities/copy.hpp"
46 #include "utilities/macros.hpp"
47 #include "utilities/powerOfTwo.hpp"
48 #include "utilities/stringUtils.hpp"
49
50 class RegMask;
51 // #include "phase.hpp"
52 class PhaseTransform;
53 class PhaseGVN;
54
55 // Arena we are currently building Nodes in
56 const uint Node::NotAMachineReg = 0xffff0000;
57
58 #ifndef PRODUCT
59 extern uint nodes_created;
60 #endif
61 #ifdef __clang__
62 #pragma clang diagnostic push
63 #pragma GCC diagnostic ignored "-Wuninitialized"
64 #endif
65
66 #ifdef ASSERT
67
68 //-------------------------- construct_node------------------------------------
69 // Set a breakpoint here to identify where a particular node index is built.
70 void Node::verify_construction() {
71 _debug_orig = nullptr;
72 // The decimal digits of _debug_idx are <compile_id> followed by 10 digits of <_idx>
73 Compile* C = Compile::current();
74 assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
75 uint64_t new_debug_idx = (uint64_t)C->compile_id() * 10000000000 + _idx;
76 set_debug_idx(new_debug_idx);
77 if (!C->phase_optimize_finished()) {
78 // Only check assert during parsing and optimization phase. Skip it while generating code.
79 assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
80 }
81 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (uint64_t)_idx == BreakAtNode)) {
82 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT, _idx, _debug_idx);
83 BREAKPOINT;
84 }
85 #if OPTO_DU_ITERATOR_ASSERT
86 _last_del = nullptr;
87 _del_tick = 0;
88 #endif
89 _hash_lock = 0;
90 }
91
92
93 // #ifdef ASSERT ...
94
95 #if OPTO_DU_ITERATOR_ASSERT
96 void DUIterator_Common::sample(const Node* node) {
97 _vdui = VerifyDUIterators;
98 _node = node;
99 _outcnt = node->_outcnt;
100 _del_tick = node->_del_tick;
101 _last = nullptr;
102 }
103
104 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
105 assert(_node == node, "consistent iterator source");
106 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
107 }
108
109 void DUIterator_Common::verify_resync() {
110 // Ensure that the loop body has just deleted the last guy produced.
111 const Node* node = _node;
112 // Ensure that at least one copy of the last-seen edge was deleted.
113 // Note: It is OK to delete multiple copies of the last-seen edge.
114 // Unfortunately, we have no way to verify that all the deletions delete
115 // that same edge. On this point we must use the Honor System.
116 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
117 assert(node->_last_del == _last, "must have deleted the edge just produced");
118 // We liked this deletion, so accept the resulting outcnt and tick.
119 _outcnt = node->_outcnt;
120 _del_tick = node->_del_tick;
121 }
122
123 void DUIterator_Common::reset(const DUIterator_Common& that) {
124 if (this == &that) return; // ignore assignment to self
125 if (!_vdui) {
126 // We need to initialize everything, overwriting garbage values.
127 _last = that._last;
128 _vdui = that._vdui;
129 }
130 // Note: It is legal (though odd) for an iterator over some node x
131 // to be reassigned to iterate over another node y. Some doubly-nested
132 // progress loops depend on being able to do this.
133 const Node* node = that._node;
134 // Re-initialize everything, except _last.
135 _node = node;
136 _outcnt = node->_outcnt;
137 _del_tick = node->_del_tick;
138 }
139
140 void DUIterator::sample(const Node* node) {
141 DUIterator_Common::sample(node); // Initialize the assertion data.
142 _refresh_tick = 0; // No refreshes have happened, as yet.
143 }
144
145 void DUIterator::verify(const Node* node, bool at_end_ok) {
146 DUIterator_Common::verify(node, at_end_ok);
147 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
148 }
149
150 void DUIterator::verify_increment() {
151 if (_refresh_tick & 1) {
152 // We have refreshed the index during this loop.
153 // Fix up _idx to meet asserts.
154 if (_idx > _outcnt) _idx = _outcnt;
155 }
156 verify(_node, true);
157 }
158
159 void DUIterator::verify_resync() {
160 // Note: We do not assert on _outcnt, because insertions are OK here.
161 DUIterator_Common::verify_resync();
162 // Make sure we are still in sync, possibly with no more out-edges:
163 verify(_node, true);
164 }
165
166 void DUIterator::reset(const DUIterator& that) {
167 if (this == &that) return; // self assignment is always a no-op
168 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
169 assert(that._idx == 0, "assign only the result of Node::outs()");
170 assert(_idx == that._idx, "already assigned _idx");
171 if (!_vdui) {
172 // We need to initialize everything, overwriting garbage values.
173 sample(that._node);
174 } else {
175 DUIterator_Common::reset(that);
176 if (_refresh_tick & 1) {
177 _refresh_tick++; // Clear the "was refreshed" flag.
178 }
179 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
180 }
181 }
182
183 void DUIterator::refresh() {
184 DUIterator_Common::sample(_node); // Re-fetch assertion data.
185 _refresh_tick |= 1; // Set the "was refreshed" flag.
186 }
187
188 void DUIterator::verify_finish() {
189 // If the loop has killed the node, do not require it to re-run.
190 if (_node->_outcnt == 0) _refresh_tick &= ~1;
191 // If this assert triggers, it means that a loop used refresh_out_pos
192 // to re-synch an iteration index, but the loop did not correctly
193 // re-run itself, using a "while (progress)" construct.
194 // This iterator enforces the rule that you must keep trying the loop
195 // until it "runs clean" without any need for refreshing.
196 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
197 }
198
199
200 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
201 DUIterator_Common::verify(node, at_end_ok);
202 Node** out = node->_out;
203 uint cnt = node->_outcnt;
204 assert(cnt == _outcnt, "no insertions allowed");
205 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
206 // This last check is carefully designed to work for NO_OUT_ARRAY.
207 }
208
209 void DUIterator_Fast::verify_limit() {
210 const Node* node = _node;
211 verify(node, true);
212 assert(_outp == node->_out + node->_outcnt, "limit still correct");
213 }
214
215 void DUIterator_Fast::verify_resync() {
216 const Node* node = _node;
217 if (_outp == node->_out + _outcnt) {
218 // Note that the limit imax, not the pointer i, gets updated with the
219 // exact count of deletions. (For the pointer it's always "--i".)
220 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
221 // This is a limit pointer, with a name like "imax".
222 // Fudge the _last field so that the common assert will be happy.
223 _last = (Node*) node->_last_del;
224 DUIterator_Common::verify_resync();
225 } else {
226 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
227 // A normal internal pointer.
228 DUIterator_Common::verify_resync();
229 // Make sure we are still in sync, possibly with no more out-edges:
230 verify(node, true);
231 }
232 }
233
234 void DUIterator_Fast::verify_relimit(uint n) {
235 const Node* node = _node;
236 assert((int)n > 0, "use imax -= n only with a positive count");
237 // This must be a limit pointer, with a name like "imax".
238 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
239 // The reported number of deletions must match what the node saw.
240 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
241 // Fudge the _last field so that the common assert will be happy.
242 _last = (Node*) node->_last_del;
243 DUIterator_Common::verify_resync();
244 }
245
246 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
247 assert(_outp == that._outp, "already assigned _outp");
248 DUIterator_Common::reset(that);
249 }
250
251 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
252 // at_end_ok means the _outp is allowed to underflow by 1
253 _outp += at_end_ok;
254 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
255 _outp -= at_end_ok;
256 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
257 }
258
259 void DUIterator_Last::verify_limit() {
260 // Do not require the limit address to be resynched.
261 //verify(node, true);
262 assert(_outp == _node->_out, "limit still correct");
263 }
264
265 void DUIterator_Last::verify_step(uint num_edges) {
266 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
267 _outcnt -= num_edges;
268 _del_tick += num_edges;
269 // Make sure we are still in sync, possibly with no more out-edges:
270 const Node* node = _node;
271 verify(node, true);
272 assert(node->_last_del == _last, "must have deleted the edge just produced");
273 }
274
275 #endif //OPTO_DU_ITERATOR_ASSERT
276
277
278 #endif //ASSERT
279
280
281 // This constant used to initialize _out may be any non-null value.
282 // The value null is reserved for the top node only.
283 #define NO_OUT_ARRAY ((Node**)-1)
284
285 // Out-of-line code from node constructors.
286 // Executed only when extra debug info. is being passed around.
287 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
288 C->set_node_notes_at(idx, nn);
289 }
290
291 // Shared initialization code.
292 inline int Node::Init(int req) {
293 Compile* C = Compile::current();
294 int idx = C->next_unique();
295 NOT_PRODUCT(_igv_idx = C->next_igv_idx());
296
297 // Allocate memory for the necessary number of edges.
298 if (req > 0) {
299 // Allocate space for _in array to have double alignment.
300 _in = (Node **) ((char *) (C->node_arena()->AmallocWords(req * sizeof(void*))));
301 }
302 // If there are default notes floating around, capture them:
303 Node_Notes* nn = C->default_node_notes();
304 if (nn != nullptr) init_node_notes(C, idx, nn);
305
306 // Note: At this point, C is dead,
307 // and we begin to initialize the new Node.
308
309 _cnt = _max = req;
310 _outcnt = _outmax = 0;
311 _class_id = Class_Node;
312 _flags = 0;
313 _out = NO_OUT_ARRAY;
314 return idx;
315 }
316
317 //------------------------------Node-------------------------------------------
318 // Create a Node, with a given number of required edges.
319 Node::Node(uint req)
320 : _idx(Init(req))
321 #ifdef ASSERT
322 , _parse_idx(_idx)
323 #endif
324 {
325 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
326 debug_only( verify_construction() );
327 NOT_PRODUCT(nodes_created++);
328 if (req == 0) {
329 _in = nullptr;
330 } else {
331 Node** to = _in;
332 for(uint i = 0; i < req; i++) {
333 to[i] = nullptr;
334 }
335 }
336 }
337
338 //------------------------------Node-------------------------------------------
339 Node::Node(Node *n0)
340 : _idx(Init(1))
341 #ifdef ASSERT
342 , _parse_idx(_idx)
343 #endif
344 {
345 debug_only( verify_construction() );
346 NOT_PRODUCT(nodes_created++);
347 assert( is_not_dead(n0), "can not use dead node");
348 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
349 }
350
351 //------------------------------Node-------------------------------------------
352 Node::Node(Node *n0, Node *n1)
353 : _idx(Init(2))
354 #ifdef ASSERT
355 , _parse_idx(_idx)
356 #endif
357 {
358 debug_only( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 assert( is_not_dead(n0), "can not use dead node");
361 assert( is_not_dead(n1), "can not use dead node");
362 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
363 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
364 }
365
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1, Node *n2)
368 : _idx(Init(3))
369 #ifdef ASSERT
370 , _parse_idx(_idx)
371 #endif
372 {
373 debug_only( verify_construction() );
374 NOT_PRODUCT(nodes_created++);
375 assert( is_not_dead(n0), "can not use dead node");
376 assert( is_not_dead(n1), "can not use dead node");
377 assert( is_not_dead(n2), "can not use dead node");
378 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
379 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
380 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
381 }
382
383 //------------------------------Node-------------------------------------------
384 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
385 : _idx(Init(4))
386 #ifdef ASSERT
387 , _parse_idx(_idx)
388 #endif
389 {
390 debug_only( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
392 assert( is_not_dead(n0), "can not use dead node");
393 assert( is_not_dead(n1), "can not use dead node");
394 assert( is_not_dead(n2), "can not use dead node");
395 assert( is_not_dead(n3), "can not use dead node");
396 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
397 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
398 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
399 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
400 }
401
402 //------------------------------Node-------------------------------------------
403 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
404 : _idx(Init(5))
405 #ifdef ASSERT
406 , _parse_idx(_idx)
407 #endif
408 {
409 debug_only( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 assert( is_not_dead(n0), "can not use dead node");
412 assert( is_not_dead(n1), "can not use dead node");
413 assert( is_not_dead(n2), "can not use dead node");
414 assert( is_not_dead(n3), "can not use dead node");
415 assert( is_not_dead(n4), "can not use dead node");
416 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
417 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
418 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
419 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
420 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
421 }
422
423 //------------------------------Node-------------------------------------------
424 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
425 Node *n4, Node *n5)
426 : _idx(Init(6))
427 #ifdef ASSERT
428 , _parse_idx(_idx)
429 #endif
430 {
431 debug_only( verify_construction() );
432 NOT_PRODUCT(nodes_created++);
433 assert( is_not_dead(n0), "can not use dead node");
434 assert( is_not_dead(n1), "can not use dead node");
435 assert( is_not_dead(n2), "can not use dead node");
436 assert( is_not_dead(n3), "can not use dead node");
437 assert( is_not_dead(n4), "can not use dead node");
438 assert( is_not_dead(n5), "can not use dead node");
439 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
444 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
445 }
446
447 //------------------------------Node-------------------------------------------
448 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
449 Node *n4, Node *n5, Node *n6)
450 : _idx(Init(7))
451 #ifdef ASSERT
452 , _parse_idx(_idx)
453 #endif
454 {
455 debug_only( verify_construction() );
456 NOT_PRODUCT(nodes_created++);
457 assert( is_not_dead(n0), "can not use dead node");
458 assert( is_not_dead(n1), "can not use dead node");
459 assert( is_not_dead(n2), "can not use dead node");
460 assert( is_not_dead(n3), "can not use dead node");
461 assert( is_not_dead(n4), "can not use dead node");
462 assert( is_not_dead(n5), "can not use dead node");
463 assert( is_not_dead(n6), "can not use dead node");
464 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
465 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
466 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
467 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
468 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
469 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
470 _in[6] = n6; if (n6 != nullptr) n6->add_out((Node *)this);
471 }
472
473 #ifdef __clang__
474 #pragma clang diagnostic pop
475 #endif
476
477
478 //------------------------------clone------------------------------------------
479 // Clone a Node.
480 Node *Node::clone() const {
481 Compile* C = Compile::current();
482 uint s = size_of(); // Size of inherited Node
483 Node *n = (Node*)C->node_arena()->AmallocWords(size_of() + _max*sizeof(Node*));
484 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
485 // Set the new input pointer array
486 n->_in = (Node**)(((char*)n)+s);
487 // Cannot share the old output pointer array, so kill it
488 n->_out = NO_OUT_ARRAY;
489 // And reset the counters to 0
490 n->_outcnt = 0;
491 n->_outmax = 0;
492 // Unlock this guy, since he is not in any hash table.
493 debug_only(n->_hash_lock = 0);
494 // Walk the old node's input list to duplicate its edges
495 uint i;
496 for( i = 0; i < len(); i++ ) {
497 Node *x = in(i);
498 n->_in[i] = x;
499 if (x != nullptr) x->add_out(n);
500 }
501 if (is_macro()) {
502 C->add_macro_node(n);
503 }
504 if (is_expensive()) {
505 C->add_expensive_node(n);
506 }
507 if (for_post_loop_opts_igvn()) {
508 // Don't add cloned node to Compile::_for_post_loop_opts_igvn list automatically.
509 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
510 n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
511 }
512 if (n->is_ParsePredicate()) {
513 C->add_parse_predicate(n->as_ParsePredicate());
514 }
515
516 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
517 bs->register_potential_barrier_node(n);
518
519 n->set_idx(C->next_unique()); // Get new unique index as well
520 NOT_PRODUCT(n->_igv_idx = C->next_igv_idx());
521 debug_only( n->verify_construction() );
522 NOT_PRODUCT(nodes_created++);
523 // Do not patch over the debug_idx of a clone, because it makes it
524 // impossible to break on the clone's moment of creation.
525 //debug_only( n->set_debug_idx( debug_idx() ) );
526
527 C->copy_node_notes_to(n, (Node*) this);
528
529 // MachNode clone
530 uint nopnds;
531 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
532 MachNode *mach = n->as_Mach();
533 MachNode *mthis = this->as_Mach();
534 // Get address of _opnd_array.
535 // It should be the same offset since it is the clone of this node.
536 MachOper **from = mthis->_opnds;
537 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
538 pointer_delta((const void*)from,
539 (const void*)(&mthis->_opnds), 1));
540 mach->_opnds = to;
541 for ( uint i = 0; i < nopnds; ++i ) {
542 to[i] = from[i]->clone();
543 }
544 }
545 if (n->is_Call()) {
546 // CallGenerator is linked to the original node.
547 CallGenerator* cg = n->as_Call()->generator();
548 if (cg != nullptr) {
549 CallGenerator* cloned_cg = cg->with_call_node(n->as_Call());
550 n->as_Call()->set_generator(cloned_cg);
551
552 C->print_inlining_assert_ready();
553 C->print_inlining_move_to(cg);
554 C->print_inlining_update(cloned_cg);
555 }
556 }
557 if (n->is_SafePoint()) {
558 // Scalar replacement and macro expansion might modify the JVMState.
559 // Clone it to make sure it's not shared between SafePointNodes.
560 n->as_SafePoint()->clone_jvms(C);
561 n->as_SafePoint()->clone_replaced_nodes();
562 }
563 if (n->is_InlineType()) {
564 C->add_inline_type(n);
565 }
566 Compile::current()->record_modified_node(n);
567 return n; // Return the clone
568 }
569
570 //---------------------------setup_is_top--------------------------------------
571 // Call this when changing the top node, to reassert the invariants
572 // required by Node::is_top. See Compile::set_cached_top_node.
573 void Node::setup_is_top() {
574 if (this == (Node*)Compile::current()->top()) {
575 // This node has just become top. Kill its out array.
576 _outcnt = _outmax = 0;
577 _out = nullptr; // marker value for top
578 assert(is_top(), "must be top");
579 } else {
580 if (_out == nullptr) _out = NO_OUT_ARRAY;
581 assert(!is_top(), "must not be top");
582 }
583 }
584
585 //------------------------------~Node------------------------------------------
586 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
587 void Node::destruct(PhaseValues* phase) {
588 Compile* compile = (phase != nullptr) ? phase->C : Compile::current();
589 if (phase != nullptr && phase->is_IterGVN()) {
590 phase->is_IterGVN()->_worklist.remove(this);
591 }
592 // If this is the most recently created node, reclaim its index. Otherwise,
593 // record the node as dead to keep liveness information accurate.
594 if ((uint)_idx+1 == compile->unique()) {
595 compile->set_unique(compile->unique()-1);
596 } else {
597 compile->record_dead_node(_idx);
598 }
599 // Clear debug info:
600 Node_Notes* nn = compile->node_notes_at(_idx);
601 if (nn != nullptr) 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, nullptr);
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
611 if (is_macro()) {
612 compile->remove_macro_node(this);
613 }
614 if (is_expensive()) {
615 compile->remove_expensive_node(this);
616 }
617 if (is_Opaque4()) {
618 compile->remove_template_assertion_predicate_opaq(this);
619 }
620 if (is_ParsePredicate()) {
621 compile->remove_parse_predicate(as_ParsePredicate());
622 }
623 if (for_post_loop_opts_igvn()) {
624 compile->remove_from_post_loop_opts_igvn(this);
625 }
626 if (is_InlineType()) {
627 compile->remove_inline_type(this);
628 }
629
630 if (is_SafePoint()) {
631 as_SafePoint()->delete_replaced_nodes();
632
633 if (is_CallStaticJava()) {
634 compile->remove_unstable_if_trap(as_CallStaticJava(), false);
635 }
636 }
637 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
638 bs->unregister_potential_barrier_node(this);
639
640 // See if the input array was allocated just prior to the object
641 int edge_size = _max*sizeof(void*);
642 int out_edge_size = _outmax*sizeof(void*);
643 char *in_array = ((char*)_in);
644 char *edge_end = in_array + edge_size;
645 char *out_array = (char*)(_out == NO_OUT_ARRAY? nullptr: _out);
646 int node_size = size_of();
647
648 #ifdef ASSERT
649 // We will not actually delete the storage, but we'll make the node unusable.
650 compile->remove_modified_node(this);
651 *(address*)this = badAddress; // smash the C++ vtbl, probably
652 _in = _out = (Node**) badAddress;
653 _max = _cnt = _outmax = _outcnt = 0;
654 #endif
655
656 // Free the output edge array
657 if (out_edge_size > 0) {
658 compile->node_arena()->Afree(out_array, out_edge_size);
659 }
660
661 // Free the input edge array and the node itself
662 if( edge_end == (char*)this ) {
663 // It was; free the input array and object all in one hit
664 #ifndef ASSERT
665 compile->node_arena()->Afree(in_array, edge_size+node_size);
666 #endif
667 } else {
668 // Free just the input array
669 compile->node_arena()->Afree(in_array, edge_size);
670
671 // Free just the object
672 #ifndef ASSERT
673 compile->node_arena()->Afree(this, node_size);
674 #endif
675 }
676 }
677
678 //------------------------------grow-------------------------------------------
679 // Grow the input array, making space for more edges
680 void Node::grow(uint len) {
681 Arena* arena = Compile::current()->node_arena();
682 uint new_max = _max;
683 if( new_max == 0 ) {
684 _max = 4;
685 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
686 Node** to = _in;
687 to[0] = nullptr;
688 to[1] = nullptr;
689 to[2] = nullptr;
690 to[3] = nullptr;
691 return;
692 }
693 new_max = next_power_of_2(len);
694 // Trimming to limit allows a uint8 to handle up to 255 edges.
695 // Previously I was using only powers-of-2 which peaked at 128 edges.
696 //if( new_max >= limit ) new_max = limit-1;
697 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
698 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // null all new space
699 _max = new_max; // Record new max length
700 // This assertion makes sure that Node::_max is wide enough to
701 // represent the numerical value of new_max.
702 assert(_max == new_max && _max > len, "int width of _max is too small");
703 }
704
705 //-----------------------------out_grow----------------------------------------
706 // Grow the input array, making space for more edges
707 void Node::out_grow( uint len ) {
708 assert(!is_top(), "cannot grow a top node's out array");
709 Arena* arena = Compile::current()->node_arena();
710 uint new_max = _outmax;
711 if( new_max == 0 ) {
712 _outmax = 4;
713 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
714 return;
715 }
716 new_max = next_power_of_2(len);
717 // Trimming to limit allows a uint8 to handle up to 255 edges.
718 // Previously I was using only powers-of-2 which peaked at 128 edges.
719 //if( new_max >= limit ) new_max = limit-1;
720 assert(_out != nullptr && _out != NO_OUT_ARRAY, "out must have sensible value");
721 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
722 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // null all new space
723 _outmax = new_max; // Record new max length
724 // This assertion makes sure that Node::_max is wide enough to
725 // represent the numerical value of new_max.
726 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
727 }
728
729 #ifdef ASSERT
730 //------------------------------is_dead----------------------------------------
731 bool Node::is_dead() const {
732 // Mach and pinch point nodes may look like dead.
733 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
734 return false;
735 for( uint i = 0; i < _max; i++ )
736 if( _in[i] != nullptr )
737 return false;
738 return true;
739 }
740
741 bool Node::is_not_dead(const Node* n) {
742 return n == nullptr || !PhaseIterGVN::is_verify_def_use() || !(n->is_dead());
743 }
744
745 bool Node::is_reachable_from_root() const {
746 ResourceMark rm;
747 Unique_Node_List wq;
748 wq.push((Node*)this);
749 RootNode* root = Compile::current()->root();
750 for (uint i = 0; i < wq.size(); i++) {
751 Node* m = wq.at(i);
752 if (m == root) {
753 return true;
754 }
755 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
756 Node* u = m->fast_out(j);
757 wq.push(u);
758 }
759 }
760 return false;
761 }
762 #endif
763
764 //------------------------------is_unreachable---------------------------------
765 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
766 assert(!is_Mach(), "doesn't work with MachNodes");
767 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != nullptr && in(0)->is_top());
768 }
769
770 //------------------------------add_req----------------------------------------
771 // Add a new required input at the end
772 void Node::add_req( Node *n ) {
773 assert( is_not_dead(n), "can not use dead node");
774
775 // Look to see if I can move precedence down one without reallocating
776 if( (_cnt >= _max) || (in(_max-1) != nullptr) )
777 grow( _max+1 );
778
779 // Find a precedence edge to move
780 if( in(_cnt) != nullptr ) { // Next precedence edge is busy?
781 uint i;
782 for( i=_cnt; i<_max; i++ )
783 if( in(i) == nullptr ) // Find the null at end of prec edge list
784 break; // There must be one, since we grew the array
785 _in[i] = in(_cnt); // Move prec over, making space for req edge
786 }
787 _in[_cnt++] = n; // Stuff over old prec edge
788 if (n != nullptr) n->add_out((Node *)this);
789 Compile::current()->record_modified_node(this);
790 }
791
792 //---------------------------add_req_batch-------------------------------------
793 // Add a new required input at the end
794 void Node::add_req_batch( Node *n, uint m ) {
795 assert( is_not_dead(n), "can not use dead node");
796 // check various edge cases
797 if ((int)m <= 1) {
798 assert((int)m >= 0, "oob");
799 if (m != 0) add_req(n);
800 return;
801 }
802
803 // Look to see if I can move precedence down one without reallocating
804 if( (_cnt+m) > _max || _in[_max-m] )
805 grow( _max+m );
806
807 // Find a precedence edge to move
808 if( _in[_cnt] != nullptr ) { // Next precedence edge is busy?
809 uint i;
810 for( i=_cnt; i<_max; i++ )
811 if( _in[i] == nullptr ) // Find the null at end of prec edge list
812 break; // There must be one, since we grew the array
813 // Slide all the precs over by m positions (assume #prec << m).
814 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
815 }
816
817 // Stuff over the old prec edges
818 for(uint i=0; i<m; i++ ) {
819 _in[_cnt++] = n;
820 }
821
822 // Insert multiple out edges on the node.
823 if (n != nullptr && !n->is_top()) {
824 for(uint i=0; i<m; i++ ) {
825 n->add_out((Node *)this);
826 }
827 }
828 Compile::current()->record_modified_node(this);
829 }
830
831 //------------------------------del_req----------------------------------------
832 // Delete the required edge and compact the edge array
833 void Node::del_req( uint idx ) {
834 assert( idx < _cnt, "oob");
835 assert( !VerifyHashTableKeys || _hash_lock == 0,
836 "remove node from hash table before modifying it");
837 // First remove corresponding def-use edge
838 Node *n = in(idx);
839 if (n != nullptr) n->del_out((Node *)this);
840 _in[idx] = in(--_cnt); // Compact the array
841 // Avoid spec violation: Gap in prec edges.
842 close_prec_gap_at(_cnt);
843 Compile::current()->record_modified_node(this);
844 }
845
846 //------------------------------del_req_ordered--------------------------------
847 // Delete the required edge and compact the edge array with preserved order
848 void Node::del_req_ordered( uint idx ) {
849 assert( idx < _cnt, "oob");
850 assert( !VerifyHashTableKeys || _hash_lock == 0,
851 "remove node from hash table before modifying it");
852 // First remove corresponding def-use edge
853 Node *n = in(idx);
854 if (n != nullptr) n->del_out((Node *)this);
855 if (idx < --_cnt) { // Not last edge ?
856 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
857 }
858 // Avoid spec violation: Gap in prec edges.
859 close_prec_gap_at(_cnt);
860 Compile::current()->record_modified_node(this);
861 }
862
863 //------------------------------ins_req----------------------------------------
864 // Insert a new required input at the end
865 void Node::ins_req( uint idx, Node *n ) {
866 assert( is_not_dead(n), "can not use dead node");
867 add_req(nullptr); // Make space
868 assert( idx < _max, "Must have allocated enough space");
869 // Slide over
870 if(_cnt-idx-1 > 0) {
871 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
872 }
873 _in[idx] = n; // Stuff over old required edge
874 if (n != nullptr) n->add_out((Node *)this); // Add reciprocal def-use edge
875 Compile::current()->record_modified_node(this);
876 }
877
878 //-----------------------------find_edge---------------------------------------
879 int Node::find_edge(Node* n) {
880 for (uint i = 0; i < len(); i++) {
881 if (_in[i] == n) return i;
882 }
883 return -1;
884 }
885
886 //----------------------------replace_edge-------------------------------------
887 int Node::replace_edge(Node* old, Node* neww, PhaseGVN* gvn) {
888 if (old == neww) return 0; // nothing to do
889 uint nrep = 0;
890 for (uint i = 0; i < len(); i++) {
891 if (in(i) == old) {
892 if (i < req()) {
893 if (gvn != nullptr) {
894 set_req_X(i, neww, gvn);
895 } else {
896 set_req(i, neww);
897 }
898 } else {
899 assert(gvn == nullptr || gvn->is_IterGVN() == nullptr, "no support for igvn here");
900 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
901 set_prec(i, neww);
902 }
903 nrep++;
904 }
905 }
906 return nrep;
907 }
908
909 /**
910 * Replace input edges in the range pointing to 'old' node.
911 */
912 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn) {
913 if (old == neww) return 0; // nothing to do
914 uint nrep = 0;
915 for (int i = start; i < end; i++) {
916 if (in(i) == old) {
917 set_req_X(i, neww, gvn);
918 nrep++;
919 }
920 }
921 return nrep;
922 }
923
924 //-------------------------disconnect_inputs-----------------------------------
925 // null out all inputs to eliminate incoming Def-Use edges.
926 void Node::disconnect_inputs(Compile* C) {
927 // the layout of Node::_in
928 // r: a required input, null is allowed
929 // p: a precedence, null values are all at the end
930 // -----------------------------------
931 // |r|...|r|p|...|p|null|...|null|
932 // | |
933 // req() len()
934 // -----------------------------------
935 for (uint i = 0; i < req(); ++i) {
936 if (in(i) != nullptr) {
937 set_req(i, nullptr);
938 }
939 }
940
941 // Remove precedence edges if any exist
942 // Note: Safepoints may have precedence edges, even during parsing
943 for (uint i = len(); i > req(); ) {
944 rm_prec(--i); // no-op if _in[i] is null
945 }
946
947 #ifdef ASSERT
948 // sanity check
949 for (uint i = 0; i < len(); ++i) {
950 assert(_in[i] == nullptr, "disconnect_inputs() failed!");
951 }
952 #endif
953
954 // Node::destruct requires all out edges be deleted first
955 // debug_only(destruct();) // no reuse benefit expected
956 C->record_dead_node(_idx);
957 }
958
959 //-----------------------------uncast---------------------------------------
960 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
961 // Strip away casting. (It is depth-limited.)
962 // Optionally, keep casts with dependencies.
963 Node* Node::uncast(bool keep_deps) const {
964 // Should be inline:
965 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
966 if (is_ConstraintCast()) {
967 return uncast_helper(this, keep_deps);
968 } else {
969 return (Node*) this;
970 }
971 }
972
973 // Find out of current node that matches opcode.
974 Node* Node::find_out_with(int opcode) {
975 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
976 Node* use = fast_out(i);
977 if (use->Opcode() == opcode) {
978 return use;
979 }
980 }
981 return nullptr;
982 }
983
984 // Return true if the current node has an out that matches opcode.
985 bool Node::has_out_with(int opcode) {
986 return (find_out_with(opcode) != nullptr);
987 }
988
989 // Return true if the current node has an out that matches any of the opcodes.
990 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
991 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
992 int opcode = fast_out(i)->Opcode();
993 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
994 return true;
995 }
996 }
997 return false;
998 }
999
1000
1001 //---------------------------uncast_helper-------------------------------------
1002 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
1003 #ifdef ASSERT
1004 uint depth_count = 0;
1005 const Node* orig_p = p;
1006 #endif
1007
1008 while (true) {
1009 #ifdef ASSERT
1010 if (depth_count >= K) {
1011 orig_p->dump(4);
1012 if (p != orig_p)
1013 p->dump(1);
1014 }
1015 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
1016 #endif
1017 if (p == nullptr || p->req() != 2) {
1018 break;
1019 } else if (p->is_ConstraintCast()) {
1020 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
1021 break; // stop at casts with dependencies
1022 }
1023 p = p->in(1);
1024 } else {
1025 break;
1026 }
1027 }
1028 return (Node*) p;
1029 }
1030
1031 //------------------------------add_prec---------------------------------------
1032 // Add a new precedence input. Precedence inputs are unordered, with
1033 // duplicates removed and nulls packed down at the end.
1034 void Node::add_prec( Node *n ) {
1035 assert( is_not_dead(n), "can not use dead node");
1036
1037 // Check for null at end
1038 if( _cnt >= _max || in(_max-1) )
1039 grow( _max+1 );
1040
1041 // Find a precedence edge to move
1042 uint i = _cnt;
1043 while( in(i) != nullptr ) {
1044 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1045 i++;
1046 }
1047 _in[i] = n; // Stuff prec edge over null
1048 if ( n != nullptr) n->add_out((Node *)this); // Add mirror edge
1049
1050 #ifdef ASSERT
1051 while ((++i)<_max) { assert(_in[i] == nullptr, "spec violation: Gap in prec edges (node %d)", _idx); }
1052 #endif
1053 Compile::current()->record_modified_node(this);
1054 }
1055
1056 //------------------------------rm_prec----------------------------------------
1057 // Remove a precedence input. Precedence inputs are unordered, with
1058 // duplicates removed and nulls packed down at the end.
1059 void Node::rm_prec( uint j ) {
1060 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1061 assert(j >= _cnt, "not a precedence edge");
1062 if (_in[j] == nullptr) return; // Avoid spec violation: Gap in prec edges.
1063 _in[j]->del_out((Node *)this);
1064 close_prec_gap_at(j);
1065 Compile::current()->record_modified_node(this);
1066 }
1067
1068 //------------------------------size_of----------------------------------------
1069 uint Node::size_of() const { return sizeof(*this); }
1070
1071 //------------------------------ideal_reg--------------------------------------
1072 uint Node::ideal_reg() const { return 0; }
1073
1074 //------------------------------jvms-------------------------------------------
1075 JVMState* Node::jvms() const { return nullptr; }
1076
1077 #ifdef ASSERT
1078 //------------------------------jvms-------------------------------------------
1079 bool Node::verify_jvms(const JVMState* using_jvms) const {
1080 for (JVMState* jvms = this->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1081 if (jvms == using_jvms) return true;
1082 }
1083 return false;
1084 }
1085
1086 //------------------------------init_NodeProperty------------------------------
1087 void Node::init_NodeProperty() {
1088 assert(_max_classes <= max_juint, "too many NodeProperty classes");
1089 assert(max_flags() <= max_juint, "too many NodeProperty flags");
1090 }
1091
1092 //-----------------------------max_flags---------------------------------------
1093 juint Node::max_flags() {
1094 return (PD::_last_flag << 1) - 1; // allow flags combination
1095 }
1096 #endif
1097
1098 //------------------------------format-----------------------------------------
1099 // Print as assembly
1100 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1101 //------------------------------emit-------------------------------------------
1102 // Emit bytes using C2_MacroAssembler
1103 void Node::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {}
1104 //------------------------------size-------------------------------------------
1105 // Size of instruction in bytes
1106 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1107
1108 //------------------------------CFG Construction-------------------------------
1109 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1110 // Goto and Return.
1111 const Node *Node::is_block_proj() const { return 0; }
1112
1113 // Minimum guaranteed type
1114 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1115
1116
1117 //------------------------------raise_bottom_type------------------------------
1118 // Get the worst-case Type output for this Node.
1119 void Node::raise_bottom_type(const Type* new_type) {
1120 if (is_Type()) {
1121 TypeNode *n = this->as_Type();
1122 if (VerifyAliases) {
1123 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1124 }
1125 n->set_type(new_type);
1126 } else if (is_Load()) {
1127 LoadNode *n = this->as_Load();
1128 if (VerifyAliases) {
1129 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1130 }
1131 n->set_type(new_type);
1132 }
1133 }
1134
1135 //------------------------------Identity---------------------------------------
1136 // Return a node that the given node is equivalent to.
1137 Node* Node::Identity(PhaseGVN* phase) {
1138 return this; // Default to no identities
1139 }
1140
1141 //------------------------------Value------------------------------------------
1142 // Compute a new Type for a node using the Type of the inputs.
1143 const Type* Node::Value(PhaseGVN* phase) const {
1144 return bottom_type(); // Default to worst-case Type
1145 }
1146
1147 //------------------------------Ideal------------------------------------------
1148 //
1149 // 'Idealize' the graph rooted at this Node.
1150 //
1151 // In order to be efficient and flexible there are some subtle invariants
1152 // these Ideal calls need to hold. Running with '-XX:VerifyIterativeGVN=1' checks
1153 // these invariants, although its too slow to have on by default. If you are
1154 // hacking an Ideal call, be sure to test with '-XX:VerifyIterativeGVN=1'
1155 //
1156 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1157 // pointer. If ANY change is made, it must return the root of the reshaped
1158 // graph - even if the root is the same Node. Example: swapping the inputs
1159 // to an AddINode gives the same answer and same root, but you still have to
1160 // return the 'this' pointer instead of null.
1161 //
1162 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1163 // Identity call to return an old Node; basically if Identity can find
1164 // another Node have the Ideal call make no change and return null.
1165 // Example: AddINode::Ideal must check for add of zero; in this case it
1166 // returns null instead of doing any graph reshaping.
1167 //
1168 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1169 // sharing there may be other users of the old Nodes relying on their current
1170 // semantics. Modifying them will break the other users.
1171 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1172 // "X+3" unchanged in case it is shared.
1173 //
1174 // If you modify the 'this' pointer's inputs, you should use
1175 // 'set_req'. If you are making a new Node (either as the new root or
1176 // some new internal piece) you may use 'init_req' to set the initial
1177 // value. You can make a new Node with either 'new' or 'clone'. In
1178 // either case, def-use info is correctly maintained.
1179 //
1180 // Example: reshape "(X+3)+4" into "X+7":
1181 // set_req(1, in(1)->in(1));
1182 // set_req(2, phase->intcon(7));
1183 // return this;
1184 // Example: reshape "X*4" into "X<<2"
1185 // return new LShiftINode(in(1), phase->intcon(2));
1186 //
1187 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1188 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1189 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1190 // return new AddINode(shift, in(1));
1191 //
1192 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1193 // These forms are faster than 'phase->transform(new ConNode())' and Do
1194 // The Right Thing with def-use info.
1195 //
1196 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1197 // graph uses the 'this' Node it must be the root. If you want a Node with
1198 // the same Opcode as the 'this' pointer use 'clone'.
1199 //
1200 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1201 return nullptr; // Default to being Ideal already
1202 }
1203
1204 // Some nodes have specific Ideal subgraph transformations only if they are
1205 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1206 // for the transformations to happen.
1207 bool Node::has_special_unique_user() const {
1208 assert(outcnt() == 1, "match only for unique out");
1209 Node* n = unique_out();
1210 int op = Opcode();
1211 if (this->is_Store()) {
1212 // Condition for back-to-back stores folding.
1213 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1214 } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1215 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1216 return n->Opcode() == Op_MemBarAcquire;
1217 } else if (op == Op_AddL) {
1218 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1219 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1220 } else if (op == Op_SubI || op == Op_SubL) {
1221 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1222 return n->Opcode() == op && n->in(2) == this;
1223 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1224 // See IfProjNode::Identity()
1225 return true;
1226 } else if ((is_IfFalse() || is_IfTrue()) && n->is_If()) {
1227 // See IfNode::fold_compares
1228 return true;
1229 } else {
1230 return false;
1231 }
1232 };
1233
1234 //--------------------------find_exact_control---------------------------------
1235 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1236 Node* Node::find_exact_control(Node* ctrl) {
1237 if (ctrl == nullptr && this->is_Region())
1238 ctrl = this->as_Region()->is_copy();
1239
1240 if (ctrl != nullptr && ctrl->is_CatchProj()) {
1241 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1242 ctrl = ctrl->in(0);
1243 if (ctrl != nullptr && !ctrl->is_top())
1244 ctrl = ctrl->in(0);
1245 }
1246
1247 if (ctrl != nullptr && ctrl->is_Proj())
1248 ctrl = ctrl->in(0);
1249
1250 return ctrl;
1251 }
1252
1253 //--------------------------dominates------------------------------------------
1254 // Helper function for MemNode::all_controls_dominate().
1255 // Check if 'this' control node dominates or equal to 'sub' control node.
1256 // We already know that if any path back to Root or Start reaches 'this',
1257 // then all paths so, so this is a simple search for one example,
1258 // not an exhaustive search for a counterexample.
1259 bool Node::dominates(Node* sub, Node_List &nlist) {
1260 assert(this->is_CFG(), "expecting control");
1261 assert(sub != nullptr && sub->is_CFG(), "expecting control");
1262
1263 // detect dead cycle without regions
1264 int iterations_without_region_limit = DominatorSearchLimit;
1265
1266 Node* orig_sub = sub;
1267 Node* dom = this;
1268 bool met_dom = false;
1269 nlist.clear();
1270
1271 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1272 // After seeing 'dom', continue up to Root or Start.
1273 // If we hit a region (backward split point), it may be a loop head.
1274 // Keep going through one of the region's inputs. If we reach the
1275 // same region again, go through a different input. Eventually we
1276 // will either exit through the loop head, or give up.
1277 // (If we get confused, break out and return a conservative 'false'.)
1278 while (sub != nullptr) {
1279 if (sub->is_top()) break; // Conservative answer for dead code.
1280 if (sub == dom) {
1281 if (nlist.size() == 0) {
1282 // No Region nodes except loops were visited before and the EntryControl
1283 // path was taken for loops: it did not walk in a cycle.
1284 return true;
1285 } else if (met_dom) {
1286 break; // already met before: walk in a cycle
1287 } else {
1288 // Region nodes were visited. Continue walk up to Start or Root
1289 // to make sure that it did not walk in a cycle.
1290 met_dom = true; // first time meet
1291 iterations_without_region_limit = DominatorSearchLimit; // Reset
1292 }
1293 }
1294 if (sub->is_Start() || sub->is_Root()) {
1295 // Success if we met 'dom' along a path to Start or Root.
1296 // We assume there are no alternative paths that avoid 'dom'.
1297 // (This assumption is up to the caller to ensure!)
1298 return met_dom;
1299 }
1300 Node* up = sub->in(0);
1301 // Normalize simple pass-through regions and projections:
1302 up = sub->find_exact_control(up);
1303 // If sub == up, we found a self-loop. Try to push past it.
1304 if (sub == up && sub->is_Loop()) {
1305 // Take loop entry path on the way up to 'dom'.
1306 up = sub->in(1); // in(LoopNode::EntryControl);
1307 } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1308 // Take in(1) path on the way up to 'dom' for regions with only one input
1309 up = sub->in(1);
1310 } else if (sub == up && sub->is_Region()) {
1311 // Try both paths for Regions with 2 input paths (it may be a loop head).
1312 // It could give conservative 'false' answer without information
1313 // which region's input is the entry path.
1314 iterations_without_region_limit = DominatorSearchLimit; // Reset
1315
1316 bool region_was_visited_before = false;
1317 // Was this Region node visited before?
1318 // If so, we have reached it because we accidentally took a
1319 // loop-back edge from 'sub' back into the body of the loop,
1320 // and worked our way up again to the loop header 'sub'.
1321 // So, take the first unexplored path on the way up to 'dom'.
1322 for (int j = nlist.size() - 1; j >= 0; j--) {
1323 intptr_t ni = (intptr_t)nlist.at(j);
1324 Node* visited = (Node*)(ni & ~1);
1325 bool visited_twice_already = ((ni & 1) != 0);
1326 if (visited == sub) {
1327 if (visited_twice_already) {
1328 // Visited 2 paths, but still stuck in loop body. Give up.
1329 return false;
1330 }
1331 // The Region node was visited before only once.
1332 // (We will repush with the low bit set, below.)
1333 nlist.remove(j);
1334 // We will find a new edge and re-insert.
1335 region_was_visited_before = true;
1336 break;
1337 }
1338 }
1339
1340 // Find an incoming edge which has not been seen yet; walk through it.
1341 assert(up == sub, "");
1342 uint skip = region_was_visited_before ? 1 : 0;
1343 for (uint i = 1; i < sub->req(); i++) {
1344 Node* in = sub->in(i);
1345 if (in != nullptr && !in->is_top() && in != sub) {
1346 if (skip == 0) {
1347 up = in;
1348 break;
1349 }
1350 --skip; // skip this nontrivial input
1351 }
1352 }
1353
1354 // Set 0 bit to indicate that both paths were taken.
1355 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1356 }
1357
1358 if (up == sub) {
1359 break; // some kind of tight cycle
1360 }
1361 if (up == orig_sub && met_dom) {
1362 // returned back after visiting 'dom'
1363 break; // some kind of cycle
1364 }
1365 if (--iterations_without_region_limit < 0) {
1366 break; // dead cycle
1367 }
1368 sub = up;
1369 }
1370
1371 // Did not meet Root or Start node in pred. chain.
1372 // Conservative answer for dead code.
1373 return false;
1374 }
1375
1376 //------------------------------remove_dead_region-----------------------------
1377 // This control node is dead. Follow the subgraph below it making everything
1378 // using it dead as well. This will happen normally via the usual IterGVN
1379 // worklist but this call is more efficient. Do not update use-def info
1380 // inside the dead region, just at the borders.
1381 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1382 // Con's are a popular node to re-hit in the hash table again.
1383 if( dead->is_Con() ) return;
1384
1385 ResourceMark rm;
1386 Node_List nstack;
1387 VectorSet dead_set; // notify uses only once
1388
1389 Node *top = igvn->C->top();
1390 nstack.push(dead);
1391 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1392
1393 while (nstack.size() > 0) {
1394 dead = nstack.pop();
1395 if (!dead_set.test_set(dead->_idx)) {
1396 // If dead has any live uses, those are now still attached. Notify them before we lose them.
1397 igvn->add_users_to_worklist(dead);
1398 }
1399 if (dead->Opcode() == Op_SafePoint) {
1400 dead->as_SafePoint()->disconnect_from_root(igvn);
1401 }
1402 if (dead->outcnt() > 0) {
1403 // Keep dead node on stack until all uses are processed.
1404 nstack.push(dead);
1405 // For all Users of the Dead... ;-)
1406 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1407 Node* use = dead->last_out(k);
1408 igvn->hash_delete(use); // Yank from hash table prior to mod
1409 if (use->in(0) == dead) { // Found another dead node
1410 assert (!use->is_Con(), "Control for Con node should be Root node.");
1411 use->set_req(0, top); // Cut dead edge to prevent processing
1412 nstack.push(use); // the dead node again.
1413 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1414 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1415 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1416 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1417 use->set_req(0, top); // Cut self edge
1418 nstack.push(use);
1419 } else { // Else found a not-dead user
1420 // Dead if all inputs are top or null
1421 bool dead_use = !use->is_Root(); // Keep empty graph alive
1422 for (uint j = 1; j < use->req(); j++) {
1423 Node* in = use->in(j);
1424 if (in == dead) { // Turn all dead inputs into TOP
1425 use->set_req(j, top);
1426 } else if (in != nullptr && !in->is_top()) {
1427 dead_use = false;
1428 }
1429 }
1430 if (dead_use) {
1431 if (use->is_Region()) {
1432 use->set_req(0, top); // Cut self edge
1433 }
1434 nstack.push(use);
1435 } else {
1436 igvn->_worklist.push(use);
1437 }
1438 }
1439 // Refresh the iterator, since any number of kills might have happened.
1440 k = dead->last_outs(kmin);
1441 }
1442 } else { // (dead->outcnt() == 0)
1443 // Done with outputs.
1444 igvn->hash_delete(dead);
1445 igvn->_worklist.remove(dead);
1446 igvn->set_type(dead, Type::TOP);
1447 // Kill all inputs to the dead guy
1448 for (uint i=0; i < dead->req(); i++) {
1449 Node *n = dead->in(i); // Get input to dead guy
1450 if (n != nullptr && !n->is_top()) { // Input is valid?
1451 dead->set_req(i, top); // Smash input away
1452 if (n->outcnt() == 0) { // Input also goes dead?
1453 if (!n->is_Con())
1454 nstack.push(n); // Clear it out as well
1455 } else if (n->outcnt() == 1 &&
1456 n->has_special_unique_user()) {
1457 igvn->add_users_to_worklist( n );
1458 } else if (n->outcnt() <= 2 && n->is_Store()) {
1459 // Push store's uses on worklist to enable folding optimization for
1460 // store/store and store/load to the same address.
1461 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1462 // and remove_globally_dead_node().
1463 igvn->add_users_to_worklist( n );
1464 } else {
1465 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1466 }
1467 }
1468 }
1469 igvn->C->remove_useless_node(dead);
1470 } // (dead->outcnt() == 0)
1471 } // while (nstack.size() > 0) for outputs
1472 return;
1473 }
1474
1475 //------------------------------remove_dead_region-----------------------------
1476 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1477 Node *n = in(0);
1478 if( !n ) return false;
1479 // Lost control into this guy? I.e., it became unreachable?
1480 // Aggressively kill all unreachable code.
1481 if (can_reshape && n->is_top()) {
1482 kill_dead_code(this, phase->is_IterGVN());
1483 return false; // Node is dead.
1484 }
1485
1486 if( n->is_Region() && n->as_Region()->is_copy() ) {
1487 Node *m = n->nonnull_req();
1488 set_req(0, m);
1489 return true;
1490 }
1491 return false;
1492 }
1493
1494 //------------------------------hash-------------------------------------------
1495 // Hash function over Nodes.
1496 uint Node::hash() const {
1497 uint sum = 0;
1498 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1499 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded nulls
1500 return (sum>>2) + _cnt + Opcode();
1501 }
1502
1503 //------------------------------cmp--------------------------------------------
1504 // Compare special parts of simple Nodes
1505 bool Node::cmp( const Node &n ) const {
1506 return true; // Must be same
1507 }
1508
1509 //------------------------------rematerialize-----------------------------------
1510 // Should we clone rather than spill this instruction?
1511 bool Node::rematerialize() const {
1512 if ( is_Mach() )
1513 return this->as_Mach()->rematerialize();
1514 else
1515 return (_flags & Flag_rematerialize) != 0;
1516 }
1517
1518 //------------------------------needs_anti_dependence_check---------------------
1519 // Nodes which use memory without consuming it, hence need antidependences.
1520 bool Node::needs_anti_dependence_check() const {
1521 if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1522 return false;
1523 }
1524 return in(1)->bottom_type()->has_memory();
1525 }
1526
1527 // Get an integer constant from a ConNode (or CastIINode).
1528 // Return a default value if there is no apparent constant here.
1529 const TypeInt* Node::find_int_type() const {
1530 if (this->is_Type()) {
1531 return this->as_Type()->type()->isa_int();
1532 } else if (this->is_Con()) {
1533 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1534 return this->bottom_type()->isa_int();
1535 }
1536 return nullptr;
1537 }
1538
1539 const TypeInteger* Node::find_integer_type(BasicType bt) const {
1540 if (this->is_Type()) {
1541 return this->as_Type()->type()->isa_integer(bt);
1542 } else if (this->is_Con()) {
1543 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1544 return this->bottom_type()->isa_integer(bt);
1545 }
1546 return nullptr;
1547 }
1548
1549 // Get a pointer constant from a ConstNode.
1550 // Returns the constant if it is a pointer ConstNode
1551 intptr_t Node::get_ptr() const {
1552 assert( Opcode() == Op_ConP, "" );
1553 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1554 }
1555
1556 // Get a narrow oop constant from a ConNNode.
1557 intptr_t Node::get_narrowcon() const {
1558 assert( Opcode() == Op_ConN, "" );
1559 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1560 }
1561
1562 // Get a long constant from a ConNode.
1563 // Return a default value if there is no apparent constant here.
1564 const TypeLong* Node::find_long_type() const {
1565 if (this->is_Type()) {
1566 return this->as_Type()->type()->isa_long();
1567 } else if (this->is_Con()) {
1568 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1569 return this->bottom_type()->isa_long();
1570 }
1571 return nullptr;
1572 }
1573
1574
1575 /**
1576 * Return a ptr type for nodes which should have it.
1577 */
1578 const TypePtr* Node::get_ptr_type() const {
1579 const TypePtr* tp = this->bottom_type()->make_ptr();
1580 #ifdef ASSERT
1581 if (tp == nullptr) {
1582 this->dump(1);
1583 assert((tp != nullptr), "unexpected node type");
1584 }
1585 #endif
1586 return tp;
1587 }
1588
1589 // Get a double constant from a ConstNode.
1590 // Returns the constant if it is a double ConstNode
1591 jdouble Node::getd() const {
1592 assert( Opcode() == Op_ConD, "" );
1593 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1594 }
1595
1596 // Get a float constant from a ConstNode.
1597 // Returns the constant if it is a float ConstNode
1598 jfloat Node::getf() const {
1599 assert( Opcode() == Op_ConF, "" );
1600 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1601 }
1602
1603 #ifndef PRODUCT
1604
1605 // Call this from debugger:
1606 Node* old_root() {
1607 Matcher* matcher = Compile::current()->matcher();
1608 if (matcher != nullptr) {
1609 Node* new_root = Compile::current()->root();
1610 Node* old_root = matcher->find_old_node(new_root);
1611 if (old_root != nullptr) {
1612 return old_root;
1613 }
1614 }
1615 tty->print("old_root: not found.\n");
1616 return nullptr;
1617 }
1618
1619 // BFS traverse all reachable nodes from start, call callback on them
1620 template <typename Callback>
1621 void visit_nodes(Node* start, Callback callback, bool traverse_output, bool only_ctrl) {
1622 Unique_Mixed_Node_List worklist;
1623 worklist.add(start);
1624 for (uint i = 0; i < worklist.size(); i++) {
1625 Node* n = worklist[i];
1626 callback(n);
1627 for (uint i = 0; i < n->len(); i++) {
1628 if (!only_ctrl || n->is_Region() || (n->Opcode() == Op_Root) || (i == TypeFunc::Control)) {
1629 // If only_ctrl is set: Add regions, the root node, or control inputs only
1630 worklist.add(n->in(i));
1631 }
1632 }
1633 if (traverse_output && !only_ctrl) {
1634 for (uint i = 0; i < n->outcnt(); i++) {
1635 worklist.add(n->raw_out(i));
1636 }
1637 }
1638 }
1639 }
1640
1641 // BFS traverse from start, return node with idx
1642 static Node* find_node_by_idx(Node* start, uint idx, bool traverse_output, bool only_ctrl) {
1643 ResourceMark rm;
1644 Node* result = nullptr;
1645 auto callback = [&] (Node* n) {
1646 if (n->_idx == idx) {
1647 if (result != nullptr) {
1648 tty->print("find_node_by_idx: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1649 (uintptr_t)result, (uintptr_t)n, idx);
1650 }
1651 result = n;
1652 }
1653 };
1654 visit_nodes(start, callback, traverse_output, only_ctrl);
1655 return result;
1656 }
1657
1658 static int node_idx_cmp(const Node** n1, const Node** n2) {
1659 return (*n1)->_idx - (*n2)->_idx;
1660 }
1661
1662 static void find_nodes_by_name(Node* start, const char* name) {
1663 ResourceMark rm;
1664 GrowableArray<const Node*> ns;
1665 auto callback = [&] (const Node* n) {
1666 if (StringUtils::is_star_match(name, n->Name())) {
1667 ns.push(n);
1668 }
1669 };
1670 visit_nodes(start, callback, true, false);
1671 ns.sort(node_idx_cmp);
1672 for (int i = 0; i < ns.length(); i++) {
1673 ns.at(i)->dump();
1674 }
1675 }
1676
1677 static void find_nodes_by_dump(Node* start, const char* pattern) {
1678 ResourceMark rm;
1679 GrowableArray<const Node*> ns;
1680 auto callback = [&] (const Node* n) {
1681 stringStream stream;
1682 n->dump("", false, &stream);
1683 if (StringUtils::is_star_match(pattern, stream.base())) {
1684 ns.push(n);
1685 }
1686 };
1687 visit_nodes(start, callback, true, false);
1688 ns.sort(node_idx_cmp);
1689 for (int i = 0; i < ns.length(); i++) {
1690 ns.at(i)->dump();
1691 }
1692 }
1693
1694 // call from debugger: find node with name pattern in new/current graph
1695 // name can contain "*" in match pattern to match any characters
1696 // the matching is case insensitive
1697 void find_nodes_by_name(const char* name) {
1698 Node* root = Compile::current()->root();
1699 find_nodes_by_name(root, name);
1700 }
1701
1702 // call from debugger: find node with name pattern in old graph
1703 // name can contain "*" in match pattern to match any characters
1704 // the matching is case insensitive
1705 void find_old_nodes_by_name(const char* name) {
1706 Node* root = old_root();
1707 find_nodes_by_name(root, name);
1708 }
1709
1710 // call from debugger: find node with dump pattern in new/current graph
1711 // can contain "*" in match pattern to match any characters
1712 // the matching is case insensitive
1713 void find_nodes_by_dump(const char* pattern) {
1714 Node* root = Compile::current()->root();
1715 find_nodes_by_dump(root, pattern);
1716 }
1717
1718 // call from debugger: find node with name pattern in old graph
1719 // can contain "*" in match pattern to match any characters
1720 // the matching is case insensitive
1721 void find_old_nodes_by_dump(const char* pattern) {
1722 Node* root = old_root();
1723 find_nodes_by_dump(root, pattern);
1724 }
1725
1726 // Call this from debugger, search in same graph as n:
1727 Node* find_node(Node* n, const int idx) {
1728 return n->find(idx);
1729 }
1730
1731 // Call this from debugger, search in new nodes:
1732 Node* find_node(const int idx) {
1733 return Compile::current()->root()->find(idx);
1734 }
1735
1736 // Call this from debugger, search in old nodes:
1737 Node* find_old_node(const int idx) {
1738 Node* root = old_root();
1739 return (root == nullptr) ? nullptr : root->find(idx);
1740 }
1741
1742 // Call this from debugger, search in same graph as n:
1743 Node* find_ctrl(Node* n, const int idx) {
1744 return n->find_ctrl(idx);
1745 }
1746
1747 // Call this from debugger, search in new nodes:
1748 Node* find_ctrl(const int idx) {
1749 return Compile::current()->root()->find_ctrl(idx);
1750 }
1751
1752 // Call this from debugger, search in old nodes:
1753 Node* find_old_ctrl(const int idx) {
1754 Node* root = old_root();
1755 return (root == nullptr) ? nullptr : root->find_ctrl(idx);
1756 }
1757
1758 //------------------------------find_ctrl--------------------------------------
1759 // Find an ancestor to this node in the control history with given _idx
1760 Node* Node::find_ctrl(int idx) {
1761 return find(idx, true);
1762 }
1763
1764 //------------------------------find-------------------------------------------
1765 // Tries to find the node with the index |idx| starting from this node. If idx is negative,
1766 // the search also includes forward (out) edges. Returns null if not found.
1767 // If only_ctrl is set, the search will only be done on control nodes. Returns null if
1768 // not found or if the node to be found is not a control node (search will not find it).
1769 Node* Node::find(const int idx, bool only_ctrl) {
1770 ResourceMark rm;
1771 return find_node_by_idx(this, abs(idx), (idx < 0), only_ctrl);
1772 }
1773
1774 class PrintBFS {
1775 public:
1776 PrintBFS(const Node* start, const int max_distance, const Node* target, const char* options, outputStream* st)
1777 : _start(start), _max_distance(max_distance), _target(target), _options(options), _output(st),
1778 _dcc(this), _info_uid(cmpkey, hashkey) {}
1779
1780 void run();
1781 private:
1782 // pipeline steps
1783 bool configure();
1784 void collect();
1785 void select();
1786 void select_all();
1787 void select_all_paths();
1788 void select_shortest_path();
1789 void sort();
1790 void print();
1791
1792 // inputs
1793 const Node* _start;
1794 const int _max_distance;
1795 const Node* _target;
1796 const char* _options;
1797 outputStream* _output;
1798
1799 // options
1800 bool _traverse_inputs = false;
1801 bool _traverse_outputs = false;
1802 struct Filter {
1803 bool _control = false;
1804 bool _memory = false;
1805 bool _data = false;
1806 bool _mixed = false;
1807 bool _other = false;
1808 bool is_empty() const {
1809 return !(_control || _memory || _data || _mixed || _other);
1810 }
1811 void set_all() {
1812 _control = true;
1813 _memory = true;
1814 _data = true;
1815 _mixed = true;
1816 _other = true;
1817 }
1818 // Check if the filter accepts the node. Go by the type categories, but also all CFG nodes
1819 // are considered to have control.
1820 bool accepts(const Node* n) {
1821 const Type* t = n->bottom_type();
1822 return ( _data && t->has_category(Type::Category::Data) ) ||
1823 ( _memory && t->has_category(Type::Category::Memory) ) ||
1824 ( _mixed && t->has_category(Type::Category::Mixed) ) ||
1825 ( _control && (t->has_category(Type::Category::Control) || n->is_CFG()) ) ||
1826 ( _other && t->has_category(Type::Category::Other) );
1827 }
1828 };
1829 Filter _filter_visit;
1830 Filter _filter_boundary;
1831 bool _sort_idx = false;
1832 bool _all_paths = false;
1833 bool _use_color = false;
1834 bool _print_blocks = false;
1835 bool _print_old = false;
1836 bool _dump_only = false;
1837 void print_options_help(bool print_examples);
1838 bool parse_options();
1839
1840 public:
1841 class DumpConfigColored : public Node::DumpConfig {
1842 public:
1843 DumpConfigColored(PrintBFS* bfs) : _bfs(bfs) {};
1844 virtual void pre_dump(outputStream* st, const Node* n);
1845 virtual void post_dump(outputStream* st);
1846 private:
1847 PrintBFS* _bfs;
1848 };
1849 private:
1850 DumpConfigColored _dcc;
1851
1852 // node info
1853 static Node* old_node(const Node* n); // mach node -> prior IR node
1854 void print_node_idx(const Node* n);
1855 void print_block_id(const Block* b);
1856 void print_node_block(const Node* n); // _pre_order, head idx, _idom, _dom_depth
1857
1858 // traversal data structures
1859 GrowableArray<const Node*> _worklist; // BFS queue
1860 void maybe_traverse(const Node* src, const Node* dst);
1861
1862 // node info annotation
1863 class Info {
1864 public:
1865 Info() : Info(nullptr, 0) {};
1866 Info(const Node* node, int distance)
1867 : _node(node), _distance_from_start(distance) {};
1868 const Node* node() const { return _node; };
1869 int distance() const { return _distance_from_start; };
1870 int distance_from_target() const { return _distance_from_target; }
1871 void set_distance_from_target(int d) { _distance_from_target = d; }
1872 GrowableArray<const Node*> edge_bwd; // pointing toward _start
1873 bool is_marked() const { return _mark; } // marked to keep during select
1874 void set_mark() { _mark = true; }
1875 private:
1876 const Node* _node;
1877 int _distance_from_start; // distance from _start
1878 int _distance_from_target = 0; // distance from _target if _all_paths
1879 bool _mark = false;
1880 };
1881 Dict _info_uid; // Node -> uid
1882 GrowableArray<Info> _info; // uid -> info
1883
1884 Info* find_info(const Node* n) {
1885 size_t uid = (size_t)_info_uid[n];
1886 if (uid == 0) {
1887 return nullptr;
1888 }
1889 return &_info.at((int)uid);
1890 }
1891
1892 void make_info(const Node* node, const int distance) {
1893 assert(find_info(node) == nullptr, "node does not yet have info");
1894 size_t uid = _info.length() + 1;
1895 _info_uid.Insert((void*)node, (void*)uid);
1896 _info.at_put_grow((int)uid, Info(node, distance));
1897 assert(find_info(node)->node() == node, "stored correct node");
1898 };
1899
1900 // filled by sort, printed by print
1901 GrowableArray<const Node*> _print_list;
1902
1903 // print header + node table
1904 void print_header() const;
1905 void print_node(const Node* n);
1906 };
1907
1908 void PrintBFS::run() {
1909 if (!configure()) {
1910 return;
1911 }
1912 collect();
1913 select();
1914 sort();
1915 print();
1916 }
1917
1918 // set up configuration for BFS and print
1919 bool PrintBFS::configure() {
1920 if (_max_distance < 0) {
1921 _output->print_cr("dump_bfs: max_distance must be non-negative!");
1922 return false;
1923 }
1924 return parse_options();
1925 }
1926
1927 // BFS traverse according to configuration, fill worklist and info
1928 void PrintBFS::collect() {
1929 maybe_traverse(_start, _start);
1930 int pos = 0;
1931 while (pos < _worklist.length()) {
1932 const Node* n = _worklist.at(pos++); // next node to traverse
1933 Info* info = find_info(n);
1934 if (!_filter_visit.accepts(n) && n != _start) {
1935 continue; // we hit boundary, do not traverse further
1936 }
1937 if (n != _start && n->is_Root()) {
1938 continue; // traversing through root node would lead to unrelated nodes
1939 }
1940 if (_traverse_inputs && _max_distance > info->distance()) {
1941 for (uint i = 0; i < n->req(); i++) {
1942 maybe_traverse(n, n->in(i));
1943 }
1944 }
1945 if (_traverse_outputs && _max_distance > info->distance()) {
1946 for (uint i = 0; i < n->outcnt(); i++) {
1947 maybe_traverse(n, n->raw_out(i));
1948 }
1949 }
1950 }
1951 }
1952
1953 // go through work list, mark those that we want to print
1954 void PrintBFS::select() {
1955 if (_target == nullptr ) {
1956 select_all();
1957 } else {
1958 if (find_info(_target) == nullptr) {
1959 _output->print_cr("Could not find target in BFS.");
1960 return;
1961 }
1962 if (_all_paths) {
1963 select_all_paths();
1964 } else {
1965 select_shortest_path();
1966 }
1967 }
1968 }
1969
1970 // take all nodes from BFS
1971 void PrintBFS::select_all() {
1972 for (int i = 0; i < _worklist.length(); i++) {
1973 const Node* n = _worklist.at(i);
1974 Info* info = find_info(n);
1975 info->set_mark();
1976 }
1977 }
1978
1979 // traverse backward from target, along edges found in BFS
1980 void PrintBFS::select_all_paths() {
1981 int pos = 0;
1982 GrowableArray<const Node*> backtrace;
1983 // start from target
1984 backtrace.push(_target);
1985 find_info(_target)->set_mark();
1986 // traverse backward
1987 while (pos < backtrace.length()) {
1988 const Node* n = backtrace.at(pos++);
1989 Info* info = find_info(n);
1990 for (int i = 0; i < info->edge_bwd.length(); i++) {
1991 // all backward edges
1992 const Node* back = info->edge_bwd.at(i);
1993 Info* back_info = find_info(back);
1994 if (!back_info->is_marked()) {
1995 // not yet found this on way back.
1996 back_info->set_distance_from_target(info->distance_from_target() + 1);
1997 if (back_info->distance_from_target() + back_info->distance() <= _max_distance) {
1998 // total distance is small enough
1999 back_info->set_mark();
2000 backtrace.push(back);
2001 }
2002 }
2003 }
2004 }
2005 }
2006
2007 void PrintBFS::select_shortest_path() {
2008 const Node* current = _target;
2009 while (true) {
2010 Info* info = find_info(current);
2011 info->set_mark();
2012 if (current == _start) {
2013 break;
2014 }
2015 // first edge -> leads us one step closer to _start
2016 current = info->edge_bwd.at(0);
2017 }
2018 }
2019
2020 // go through worklist in desired order, put the marked ones in print list
2021 void PrintBFS::sort() {
2022 if (_traverse_inputs && !_traverse_outputs) {
2023 // reverse order
2024 for (int i = _worklist.length() - 1; i >= 0; i--) {
2025 const Node* n = _worklist.at(i);
2026 Info* info = find_info(n);
2027 if (info->is_marked()) {
2028 _print_list.push(n);
2029 }
2030 }
2031 } else {
2032 // same order as worklist
2033 for (int i = 0; i < _worklist.length(); i++) {
2034 const Node* n = _worklist.at(i);
2035 Info* info = find_info(n);
2036 if (info->is_marked()) {
2037 _print_list.push(n);
2038 }
2039 }
2040 }
2041 if (_sort_idx) {
2042 _print_list.sort(node_idx_cmp);
2043 }
2044 }
2045
2046 // go through printlist and print
2047 void PrintBFS::print() {
2048 if (_print_list.length() > 0 ) {
2049 print_header();
2050 for (int i = 0; i < _print_list.length(); i++) {
2051 const Node* n = _print_list.at(i);
2052 print_node(n);
2053 }
2054 } else {
2055 _output->print_cr("No nodes to print.");
2056 }
2057 }
2058
2059 void PrintBFS::print_options_help(bool print_examples) {
2060 _output->print_cr("Usage: node->dump_bfs(int max_distance, Node* target, char* options)");
2061 _output->print_cr("");
2062 _output->print_cr("Use cases:");
2063 _output->print_cr(" BFS traversal: no target required");
2064 _output->print_cr(" shortest path: set target");
2065 _output->print_cr(" all paths: set target and put 'A' in options");
2066 _output->print_cr(" detect loop: subcase of all paths, have start==target");
2067 _output->print_cr("");
2068 _output->print_cr("Arguments:");
2069 _output->print_cr(" this/start: staring point of BFS");
2070 _output->print_cr(" target:");
2071 _output->print_cr(" if null: simple BFS");
2072 _output->print_cr(" else: shortest path or all paths between this/start and target");
2073 _output->print_cr(" options:");
2074 _output->print_cr(" if null: same as \"cdmox@B\"");
2075 _output->print_cr(" else: use combination of following characters");
2076 _output->print_cr(" h: display this help info");
2077 _output->print_cr(" H: display this help info, with examples");
2078 _output->print_cr(" +: traverse in-edges (on if neither + nor -)");
2079 _output->print_cr(" -: traverse out-edges");
2080 _output->print_cr(" c: visit control nodes");
2081 _output->print_cr(" d: visit data nodes");
2082 _output->print_cr(" m: visit memory nodes");
2083 _output->print_cr(" o: visit other nodes");
2084 _output->print_cr(" x: visit mixed nodes");
2085 _output->print_cr(" C: boundary control nodes");
2086 _output->print_cr(" D: boundary data nodes");
2087 _output->print_cr(" M: boundary memory nodes");
2088 _output->print_cr(" O: boundary other nodes");
2089 _output->print_cr(" X: boundary mixed nodes");
2090 _output->print_cr(" #: display node category in color (not supported in all terminals)");
2091 _output->print_cr(" S: sort displayed nodes by node idx");
2092 _output->print_cr(" A: all paths (not just shortest path to target)");
2093 _output->print_cr(" @: print old nodes - before matching (if available)");
2094 _output->print_cr(" B: print scheduling blocks (if available)");
2095 _output->print_cr(" $: dump only, no header, no other columns");
2096 _output->print_cr("");
2097 _output->print_cr("recursively follow edges to nodes with permitted visit types,");
2098 _output->print_cr("on the boundary additionally display nodes allowed in boundary types");
2099 _output->print_cr("Note: the categories can be overlapping. For example a mixed node");
2100 _output->print_cr(" can contain control and memory output. Some from the other");
2101 _output->print_cr(" category are also control (Halt, Return, etc).");
2102 _output->print_cr("");
2103 _output->print_cr("output columns:");
2104 _output->print_cr(" dist: BFS distance to this/start");
2105 _output->print_cr(" apd: all paths distance (d_outputart + d_target)");
2106 _output->print_cr(" block: block identifier, based on _pre_order");
2107 _output->print_cr(" head: first node in block");
2108 _output->print_cr(" idom: head node of idom block");
2109 _output->print_cr(" depth: depth of block (_dom_depth)");
2110 _output->print_cr(" old: old IR node - before matching");
2111 _output->print_cr(" dump: node->dump()");
2112 _output->print_cr("");
2113 _output->print_cr("Note: if none of the \"cmdxo\" characters are in the options string");
2114 _output->print_cr(" then we set all of them.");
2115 _output->print_cr(" This allows for short strings like \"#\" for colored input traversal");
2116 _output->print_cr(" or \"-#\" for colored output traversal.");
2117 if (print_examples) {
2118 _output->print_cr("");
2119 _output->print_cr("Examples:");
2120 _output->print_cr(" if->dump_bfs(10, 0, \"+cxo\")");
2121 _output->print_cr(" starting at some if node, traverse inputs recursively");
2122 _output->print_cr(" only along control (mixed and other can also be control)");
2123 _output->print_cr(" phi->dump_bfs(5, 0, \"-dxo\")");
2124 _output->print_cr(" starting at phi node, traverse outputs recursively");
2125 _output->print_cr(" only along data (mixed and other can also have data flow)");
2126 _output->print_cr(" find_node(385)->dump_bfs(3, 0, \"cdmox+#@B\")");
2127 _output->print_cr(" find inputs of node 385, up to 3 nodes up (+)");
2128 _output->print_cr(" traverse all nodes (cdmox), use colors (#)");
2129 _output->print_cr(" display old nodes and blocks, if they exist");
2130 _output->print_cr(" useful call to start with");
2131 _output->print_cr(" find_node(102)->dump_bfs(10, 0, \"dCDMOX-\")");
2132 _output->print_cr(" find non-data dependencies of a data node");
2133 _output->print_cr(" follow data node outputs until we find another category");
2134 _output->print_cr(" node as the boundary");
2135 _output->print_cr(" x->dump_bfs(10, y, 0)");
2136 _output->print_cr(" find shortest path from x to y, along any edge or node");
2137 _output->print_cr(" will not find a path if it is longer than 10");
2138 _output->print_cr(" useful to find how x and y are related");
2139 _output->print_cr(" find_node(741)->dump_bfs(20, find_node(746), \"c+\")");
2140 _output->print_cr(" find shortest control path between two nodes");
2141 _output->print_cr(" find_node(741)->dump_bfs(8, find_node(746), \"cdmox+A\")");
2142 _output->print_cr(" find all paths (A) between two nodes of length at most 8");
2143 _output->print_cr(" find_node(741)->dump_bfs(7, find_node(741), \"c+A\")");
2144 _output->print_cr(" find all control loops for this node");
2145 }
2146 }
2147
2148 bool PrintBFS::parse_options() {
2149 if (_options == nullptr) {
2150 _options = "cdmox@B"; // default options
2151 }
2152 size_t len = strlen(_options);
2153 for (size_t i = 0; i < len; i++) {
2154 switch (_options[i]) {
2155 case '+':
2156 _traverse_inputs = true;
2157 break;
2158 case '-':
2159 _traverse_outputs = true;
2160 break;
2161 case 'c':
2162 _filter_visit._control = true;
2163 break;
2164 case 'm':
2165 _filter_visit._memory = true;
2166 break;
2167 case 'd':
2168 _filter_visit._data = true;
2169 break;
2170 case 'x':
2171 _filter_visit._mixed = true;
2172 break;
2173 case 'o':
2174 _filter_visit._other = true;
2175 break;
2176 case 'C':
2177 _filter_boundary._control = true;
2178 break;
2179 case 'M':
2180 _filter_boundary._memory = true;
2181 break;
2182 case 'D':
2183 _filter_boundary._data = true;
2184 break;
2185 case 'X':
2186 _filter_boundary._mixed = true;
2187 break;
2188 case 'O':
2189 _filter_boundary._other = true;
2190 break;
2191 case 'S':
2192 _sort_idx = true;
2193 break;
2194 case 'A':
2195 _all_paths = true;
2196 break;
2197 case '#':
2198 _use_color = true;
2199 break;
2200 case 'B':
2201 _print_blocks = true;
2202 break;
2203 case '@':
2204 _print_old = true;
2205 break;
2206 case '$':
2207 _dump_only = true;
2208 break;
2209 case 'h':
2210 print_options_help(false);
2211 return false;
2212 case 'H':
2213 print_options_help(true);
2214 return false;
2215 default:
2216 _output->print_cr("dump_bfs: Unrecognized option \'%c\'", _options[i]);
2217 _output->print_cr("for help, run: find_node(0)->dump_bfs(0,0,\"H\")");
2218 return false;
2219 }
2220 }
2221 if (!_traverse_inputs && !_traverse_outputs) {
2222 _traverse_inputs = true;
2223 }
2224 if (_filter_visit.is_empty()) {
2225 _filter_visit.set_all();
2226 }
2227 Compile* C = Compile::current();
2228 _print_old &= (C->matcher() != nullptr); // only show old if there are new
2229 _print_blocks &= (C->cfg() != nullptr); // only show blocks if available
2230 return true;
2231 }
2232
2233 void PrintBFS::DumpConfigColored::pre_dump(outputStream* st, const Node* n) {
2234 if (!_bfs->_use_color) {
2235 return;
2236 }
2237 Info* info = _bfs->find_info(n);
2238 if (info == nullptr || !info->is_marked()) {
2239 return;
2240 }
2241
2242 const Type* t = n->bottom_type();
2243 switch (t->category()) {
2244 case Type::Category::Data:
2245 st->print("\u001b[34m");
2246 break;
2247 case Type::Category::Memory:
2248 st->print("\u001b[32m");
2249 break;
2250 case Type::Category::Mixed:
2251 st->print("\u001b[35m");
2252 break;
2253 case Type::Category::Control:
2254 st->print("\u001b[31m");
2255 break;
2256 case Type::Category::Other:
2257 st->print("\u001b[33m");
2258 break;
2259 case Type::Category::Undef:
2260 n->dump();
2261 assert(false, "category undef ??");
2262 break;
2263 default:
2264 n->dump();
2265 assert(false, "not covered");
2266 break;
2267 }
2268 }
2269
2270 void PrintBFS::DumpConfigColored::post_dump(outputStream* st) {
2271 if (!_bfs->_use_color) {
2272 return;
2273 }
2274 st->print("\u001b[0m"); // white
2275 }
2276
2277 Node* PrintBFS::old_node(const Node* n) {
2278 Compile* C = Compile::current();
2279 if (C->matcher() == nullptr || !C->node_arena()->contains(n)) {
2280 return (Node*)nullptr;
2281 } else {
2282 return C->matcher()->find_old_node(n);
2283 }
2284 }
2285
2286 void PrintBFS::print_node_idx(const Node* n) {
2287 Compile* C = Compile::current();
2288 char buf[30];
2289 if (n == nullptr) {
2290 os::snprintf_checked(buf, sizeof(buf), "_"); // null
2291 } else if (C->node_arena()->contains(n)) {
2292 os::snprintf_checked(buf, sizeof(buf), "%d", n->_idx); // new node
2293 } else {
2294 os::snprintf_checked(buf, sizeof(buf), "o%d", n->_idx); // old node
2295 }
2296 _output->print("%6s", buf);
2297 }
2298
2299 void PrintBFS::print_block_id(const Block* b) {
2300 Compile* C = Compile::current();
2301 char buf[30];
2302 os::snprintf_checked(buf, sizeof(buf), "B%d", b->_pre_order);
2303 _output->print("%7s", buf);
2304 }
2305
2306 void PrintBFS::print_node_block(const Node* n) {
2307 Compile* C = Compile::current();
2308 Block* b = C->node_arena()->contains(n)
2309 ? C->cfg()->get_block_for_node(n)
2310 : nullptr; // guard against old nodes
2311 if (b == nullptr) {
2312 _output->print(" _"); // Block
2313 _output->print(" _"); // head
2314 _output->print(" _"); // idom
2315 _output->print(" _"); // depth
2316 } else {
2317 print_block_id(b);
2318 print_node_idx(b->head());
2319 if (b->_idom) {
2320 print_node_idx(b->_idom->head());
2321 } else {
2322 _output->print(" _"); // idom
2323 }
2324 _output->print("%6d ", b->_dom_depth);
2325 }
2326 }
2327
2328 // filter, and add to worklist, add info, note traversal edges
2329 void PrintBFS::maybe_traverse(const Node* src, const Node* dst) {
2330 if (dst != nullptr &&
2331 (_filter_visit.accepts(dst) ||
2332 _filter_boundary.accepts(dst) ||
2333 dst == _start)) { // correct category or start?
2334 if (find_info(dst) == nullptr) {
2335 // never visited - set up info
2336 _worklist.push(dst);
2337 int d = 0;
2338 if (dst != _start) {
2339 d = find_info(src)->distance() + 1;
2340 }
2341 make_info(dst, d);
2342 }
2343 if (src != dst) {
2344 // traversal edges useful during select
2345 find_info(dst)->edge_bwd.push(src);
2346 }
2347 }
2348 }
2349
2350 void PrintBFS::print_header() const {
2351 if (_dump_only) {
2352 return; // no header in dump only mode
2353 }
2354 _output->print("dist"); // distance
2355 if (_all_paths) {
2356 _output->print(" apd"); // all paths distance
2357 }
2358 if (_print_blocks) {
2359 _output->print(" [block head idom depth]"); // block
2360 }
2361 if (_print_old) {
2362 _output->print(" old"); // old node
2363 }
2364 _output->print(" dump\n"); // node dump
2365 _output->print_cr("---------------------------------------------");
2366 }
2367
2368 void PrintBFS::print_node(const Node* n) {
2369 if (_dump_only) {
2370 n->dump("\n", false, _output, &_dcc);
2371 return;
2372 }
2373 _output->print("%4d", find_info(n)->distance());// distance
2374 if (_all_paths) {
2375 Info* info = find_info(n);
2376 int apd = info->distance() + info->distance_from_target();
2377 _output->print("%4d", apd); // all paths distance
2378 }
2379 if (_print_blocks) {
2380 print_node_block(n); // block
2381 }
2382 if (_print_old) {
2383 print_node_idx(old_node(n)); // old node
2384 }
2385 _output->print(" ");
2386 n->dump("\n", false, _output, &_dcc); // node dump
2387 }
2388
2389 //------------------------------dump_bfs--------------------------------------
2390 // Call this from debugger
2391 // Useful for BFS traversal, shortest path, all path, loop detection, etc
2392 // Designed to be more readable, and provide additional info
2393 // To find all options, run:
2394 // find_node(0)->dump_bfs(0,0,"H")
2395 void Node::dump_bfs(const int max_distance, Node* target, const char* options) const {
2396 dump_bfs(max_distance, target, options, tty);
2397 }
2398
2399 // Used to dump to stream.
2400 void Node::dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st) const {
2401 PrintBFS bfs(this, max_distance, target, options, st);
2402 bfs.run();
2403 }
2404
2405 // Call this from debugger, with default arguments
2406 void Node::dump_bfs(const int max_distance) const {
2407 dump_bfs(max_distance, nullptr, nullptr);
2408 }
2409
2410 // -----------------------------dump_idx---------------------------------------
2411 void Node::dump_idx(bool align, outputStream* st, DumpConfig* dc) const {
2412 if (dc != nullptr) {
2413 dc->pre_dump(st, this);
2414 }
2415 Compile* C = Compile::current();
2416 bool is_new = C->node_arena()->contains(this);
2417 if (align) { // print prefix empty spaces$
2418 // +1 for leading digit, +1 for "o"
2419 uint max_width = static_cast<uint>(log10(static_cast<double>(C->unique()))) + 2;
2420 // +1 for leading digit, maybe +1 for "o"
2421 uint width = static_cast<uint>(log10(static_cast<double>(_idx))) + 1 + (is_new ? 0 : 1);
2422 while (max_width > width) {
2423 st->print(" ");
2424 width++;
2425 }
2426 }
2427 if (!is_new) {
2428 st->print("o");
2429 }
2430 st->print("%d", _idx);
2431 if (dc != nullptr) {
2432 dc->post_dump(st);
2433 }
2434 }
2435
2436 // -----------------------------dump_name--------------------------------------
2437 void Node::dump_name(outputStream* st, DumpConfig* dc) const {
2438 if (dc != nullptr) {
2439 dc->pre_dump(st, this);
2440 }
2441 st->print("%s", Name());
2442 if (dc != nullptr) {
2443 dc->post_dump(st);
2444 }
2445 }
2446
2447 // -----------------------------Name-------------------------------------------
2448 extern const char *NodeClassNames[];
2449 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
2450
2451 static bool is_disconnected(const Node* n) {
2452 for (uint i = 0; i < n->req(); i++) {
2453 if (n->in(i) != nullptr) return false;
2454 }
2455 return true;
2456 }
2457
2458 #ifdef ASSERT
2459 void Node::dump_orig(outputStream *st, bool print_key) const {
2460 Compile* C = Compile::current();
2461 Node* orig = _debug_orig;
2462 if (not_a_node(orig)) orig = nullptr;
2463 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2464 if (orig == nullptr) return;
2465 if (print_key) {
2466 st->print(" !orig=");
2467 }
2468 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
2469 if (not_a_node(fast)) fast = nullptr;
2470 while (orig != nullptr) {
2471 bool discon = is_disconnected(orig); // if discon, print [123] else 123
2472 if (discon) st->print("[");
2473 if (!Compile::current()->node_arena()->contains(orig))
2474 st->print("o");
2475 st->print("%d", orig->_idx);
2476 if (discon) st->print("]");
2477 orig = orig->debug_orig();
2478 if (not_a_node(orig)) orig = nullptr;
2479 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2480 if (orig != nullptr) st->print(",");
2481 if (fast != nullptr) {
2482 // Step fast twice for each single step of orig:
2483 fast = fast->debug_orig();
2484 if (not_a_node(fast)) fast = nullptr;
2485 if (fast != nullptr && fast != orig) {
2486 fast = fast->debug_orig();
2487 if (not_a_node(fast)) fast = nullptr;
2488 }
2489 if (fast == orig) {
2490 st->print("...");
2491 break;
2492 }
2493 }
2494 }
2495 }
2496
2497 void Node::set_debug_orig(Node* orig) {
2498 _debug_orig = orig;
2499 if (BreakAtNode == 0) return;
2500 if (not_a_node(orig)) orig = nullptr;
2501 int trip = 10;
2502 while (orig != nullptr) {
2503 if (orig->debug_idx() == BreakAtNode || (uintx)orig->_idx == BreakAtNode) {
2504 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT " orig._idx=%d orig._debug_idx=" UINT64_FORMAT,
2505 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
2506 BREAKPOINT;
2507 }
2508 orig = orig->debug_orig();
2509 if (not_a_node(orig)) orig = nullptr;
2510 if (trip-- <= 0) break;
2511 }
2512 }
2513 #endif //ASSERT
2514
2515 //------------------------------dump------------------------------------------
2516 // Dump a Node
2517 void Node::dump(const char* suffix, bool mark, outputStream* st, DumpConfig* dc) const {
2518 Compile* C = Compile::current();
2519 bool is_new = C->node_arena()->contains(this);
2520 C->_in_dump_cnt++;
2521
2522 // idx mark name ===
2523 dump_idx(true, st, dc);
2524 st->print(mark ? " >" : " ");
2525 dump_name(st, dc);
2526 st->print(" === ");
2527
2528 // Dump the required and precedence inputs
2529 dump_req(st, dc);
2530 dump_prec(st, dc);
2531 // Dump the outputs
2532 dump_out(st, dc);
2533
2534 if (is_disconnected(this)) {
2535 #ifdef ASSERT
2536 st->print(" [" UINT64_FORMAT "]", debug_idx());
2537 dump_orig(st);
2538 #endif
2539 st->cr();
2540 C->_in_dump_cnt--;
2541 return; // don't process dead nodes
2542 }
2543
2544 if (C->clone_map().value(_idx) != 0) {
2545 C->clone_map().dump(_idx, st);
2546 }
2547 // Dump node-specific info
2548 dump_spec(st);
2549 #ifdef ASSERT
2550 // Dump the non-reset _debug_idx
2551 if (Verbose && WizardMode) {
2552 st->print(" [" UINT64_FORMAT "]", debug_idx());
2553 }
2554 #endif
2555
2556 const Type *t = bottom_type();
2557
2558 if (t != nullptr && (t->isa_instptr() || t->isa_instklassptr())) {
2559 const TypeInstPtr *toop = t->isa_instptr();
2560 const TypeInstKlassPtr *tkls = t->isa_instklassptr();
2561 if (toop) {
2562 st->print(" Oop:");
2563 } else if (tkls) {
2564 st->print(" Klass:");
2565 }
2566 t->dump_on(st);
2567 } else if (t == Type::MEMORY) {
2568 st->print(" Memory:");
2569 MemNode::dump_adr_type(this, adr_type(), st);
2570 } else if (Verbose || WizardMode) {
2571 st->print(" Type:");
2572 if (t) {
2573 t->dump_on(st);
2574 } else {
2575 st->print("no type");
2576 }
2577 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
2578 // Dump MachSpillcopy vector type.
2579 t->dump_on(st);
2580 }
2581 if (is_new) {
2582 DEBUG_ONLY(dump_orig(st));
2583 Node_Notes* nn = C->node_notes_at(_idx);
2584 if (nn != nullptr && !nn->is_clear()) {
2585 if (nn->jvms() != nullptr) {
2586 st->print(" !jvms:");
2587 nn->jvms()->dump_spec(st);
2588 }
2589 }
2590 }
2591 if (suffix) st->print("%s", suffix);
2592 C->_in_dump_cnt--;
2593 }
2594
2595 // call from debugger: dump node to tty with newline
2596 void Node::dump() const {
2597 dump("\n");
2598 }
2599
2600 //------------------------------dump_req--------------------------------------
2601 void Node::dump_req(outputStream* st, DumpConfig* dc) const {
2602 // Dump the required input edges
2603 for (uint i = 0; i < req(); i++) { // For all required inputs
2604 Node* d = in(i);
2605 if (d == nullptr) {
2606 st->print("_ ");
2607 } else if (not_a_node(d)) {
2608 st->print("not_a_node "); // uninitialized, sentinel, garbage, etc.
2609 } else {
2610 d->dump_idx(false, st, dc);
2611 st->print(" ");
2612 }
2613 }
2614 }
2615
2616
2617 //------------------------------dump_prec-------------------------------------
2618 void Node::dump_prec(outputStream* st, DumpConfig* dc) const {
2619 // Dump the precedence edges
2620 int any_prec = 0;
2621 for (uint i = req(); i < len(); i++) { // For all precedence inputs
2622 Node* p = in(i);
2623 if (p != nullptr) {
2624 if (!any_prec++) st->print(" |");
2625 if (not_a_node(p)) { st->print("not_a_node "); continue; }
2626 p->dump_idx(false, st, dc);
2627 st->print(" ");
2628 }
2629 }
2630 }
2631
2632 //------------------------------dump_out--------------------------------------
2633 void Node::dump_out(outputStream* st, DumpConfig* dc) const {
2634 // Delimit the output edges
2635 st->print(" [[ ");
2636 // Dump the output edges
2637 for (uint i = 0; i < _outcnt; i++) { // For all outputs
2638 Node* u = _out[i];
2639 if (u == nullptr) {
2640 st->print("_ ");
2641 } else if (not_a_node(u)) {
2642 st->print("not_a_node ");
2643 } else {
2644 u->dump_idx(false, st, dc);
2645 st->print(" ");
2646 }
2647 }
2648 st->print("]] ");
2649 }
2650
2651 //------------------------------dump-------------------------------------------
2652 // call from debugger: dump Node's inputs (or outputs if d negative)
2653 void Node::dump(int d) const {
2654 dump_bfs(abs(d), nullptr, (d > 0) ? "+$" : "-$");
2655 }
2656
2657 //------------------------------dump_ctrl--------------------------------------
2658 // call from debugger: dump Node's control inputs (or outputs if d negative)
2659 void Node::dump_ctrl(int d) const {
2660 dump_bfs(abs(d), nullptr, (d > 0) ? "+$c" : "-$c");
2661 }
2662
2663 //-----------------------------dump_compact------------------------------------
2664 void Node::dump_comp() const {
2665 this->dump_comp("\n");
2666 }
2667
2668 //-----------------------------dump_compact------------------------------------
2669 // Dump a Node in compact representation, i.e., just print its name and index.
2670 // Nodes can specify additional specifics to print in compact representation by
2671 // implementing dump_compact_spec.
2672 void Node::dump_comp(const char* suffix, outputStream *st) const {
2673 Compile* C = Compile::current();
2674 C->_in_dump_cnt++;
2675 st->print("%s(%d)", Name(), _idx);
2676 this->dump_compact_spec(st);
2677 if (suffix) {
2678 st->print("%s", suffix);
2679 }
2680 C->_in_dump_cnt--;
2681 }
2682
2683 // VERIFICATION CODE
2684 // Verify all nodes if verify_depth is negative
2685 void Node::verify(int verify_depth, VectorSet& visited, Node_List& worklist) {
2686 assert(verify_depth != 0, "depth should not be 0");
2687 Compile* C = Compile::current();
2688 uint last_index_on_current_depth = worklist.size() - 1;
2689 verify_depth--; // Visiting the first node on depth 1
2690 // Only add nodes to worklist if verify_depth is negative (visit all nodes) or greater than 0
2691 bool add_to_worklist = verify_depth != 0;
2692
2693 for (uint list_index = 0; list_index < worklist.size(); list_index++) {
2694 Node* n = worklist[list_index];
2695
2696 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2697 if (C->cached_top_node() == nullptr) {
2698 C->set_cached_top_node((Node*)n);
2699 }
2700 assert(C->cached_top_node() == n, "TOP node must be unique");
2701 }
2702
2703 uint in_len = n->len();
2704 for (uint i = 0; i < in_len; i++) {
2705 Node* x = n->_in[i];
2706 if (!x || x->is_top()) {
2707 continue;
2708 }
2709
2710 // Verify my input has a def-use edge to me
2711 // Count use-def edges from n to x
2712 int cnt = 1;
2713 for (uint j = 0; j < i; j++) {
2714 if (n->_in[j] == x) {
2715 cnt++;
2716 break;
2717 }
2718 }
2719 if (cnt == 2) {
2720 // x is already checked as n's previous input, skip its duplicated def-use count checking
2721 continue;
2722 }
2723 for (uint j = i + 1; j < in_len; j++) {
2724 if (n->_in[j] == x) {
2725 cnt++;
2726 }
2727 }
2728
2729 // Count def-use edges from x to n
2730 uint max = x->_outcnt;
2731 for (uint k = 0; k < max; k++) {
2732 if (x->_out[k] == n) {
2733 cnt--;
2734 }
2735 }
2736 assert(cnt == 0, "mismatched def-use edge counts");
2737
2738 if (add_to_worklist && !visited.test_set(x->_idx)) {
2739 worklist.push(x);
2740 }
2741 }
2742
2743 if (verify_depth > 0 && list_index == last_index_on_current_depth) {
2744 // All nodes on this depth were processed and its inputs are on the worklist. Decrement verify_depth and
2745 // store the current last list index which is the last node in the list with the new depth. All nodes
2746 // added afterwards will have a new depth again. Stop adding new nodes if depth limit is reached (=0).
2747 verify_depth--;
2748 if (verify_depth == 0) {
2749 add_to_worklist = false;
2750 }
2751 last_index_on_current_depth = worklist.size() - 1;
2752 }
2753 }
2754 }
2755 #endif // not PRODUCT
2756
2757 //------------------------------Registers--------------------------------------
2758 // Do we Match on this edge index or not? Generally false for Control
2759 // and true for everything else. Weird for calls & returns.
2760 uint Node::match_edge(uint idx) const {
2761 return idx; // True for other than index 0 (control)
2762 }
2763
2764 // Register classes are defined for specific machines
2765 const RegMask &Node::out_RegMask() const {
2766 ShouldNotCallThis();
2767 return RegMask::Empty;
2768 }
2769
2770 const RegMask &Node::in_RegMask(uint) const {
2771 ShouldNotCallThis();
2772 return RegMask::Empty;
2773 }
2774
2775 void Node_Array::grow(uint i) {
2776 assert(_max > 0, "invariant");
2777 uint old = _max;
2778 _max = next_power_of_2(i);
2779 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2780 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2781 }
2782
2783 void Node_Array::insert(uint i, Node* n) {
2784 if (_nodes[_max - 1]) {
2785 grow(_max);
2786 }
2787 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i + 1], ((_max - i - 1) * sizeof(Node*)));
2788 _nodes[i] = n;
2789 }
2790
2791 void Node_Array::remove(uint i) {
2792 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i + 1], (HeapWord*)&_nodes[i], ((_max - i - 1) * sizeof(Node*)));
2793 _nodes[_max - 1] = nullptr;
2794 }
2795
2796 void Node_Array::dump() const {
2797 #ifndef PRODUCT
2798 for (uint i = 0; i < _max; i++) {
2799 Node* nn = _nodes[i];
2800 if (nn != nullptr) {
2801 tty->print("%5d--> ",i); nn->dump();
2802 }
2803 }
2804 #endif
2805 }
2806
2807 //--------------------------is_iteratively_computed------------------------------
2808 // Operation appears to be iteratively computed (such as an induction variable)
2809 // It is possible for this operation to return false for a loop-varying
2810 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2811 bool Node::is_iteratively_computed() {
2812 if (ideal_reg()) { // does operation have a result register?
2813 for (uint i = 1; i < req(); i++) {
2814 Node* n = in(i);
2815 if (n != nullptr && n->is_Phi()) {
2816 for (uint j = 1; j < n->req(); j++) {
2817 if (n->in(j) == this) {
2818 return true;
2819 }
2820 }
2821 }
2822 }
2823 }
2824 return false;
2825 }
2826
2827 //--------------------------find_similar------------------------------
2828 // Return a node with opcode "opc" and same inputs as "this" if one can
2829 // be found; Otherwise return null;
2830 Node* Node::find_similar(int opc) {
2831 if (req() >= 2) {
2832 Node* def = in(1);
2833 if (def && def->outcnt() >= 2) {
2834 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2835 Node* use = def->fast_out(i);
2836 if (use != this &&
2837 use->Opcode() == opc &&
2838 use->req() == req()) {
2839 uint j;
2840 for (j = 0; j < use->req(); j++) {
2841 if (use->in(j) != in(j)) {
2842 break;
2843 }
2844 }
2845 if (j == use->req()) {
2846 return use;
2847 }
2848 }
2849 }
2850 }
2851 }
2852 return nullptr;
2853 }
2854
2855
2856 //--------------------------unique_ctrl_out_or_null-------------------------
2857 // Return the unique control out if only one. Null if none or more than one.
2858 Node* Node::unique_ctrl_out_or_null() const {
2859 Node* found = nullptr;
2860 for (uint i = 0; i < outcnt(); i++) {
2861 Node* use = raw_out(i);
2862 if (use->is_CFG() && use != this) {
2863 if (found != nullptr) {
2864 return nullptr;
2865 }
2866 found = use;
2867 }
2868 }
2869 return found;
2870 }
2871
2872 //--------------------------unique_ctrl_out------------------------------
2873 // Return the unique control out. Asserts if none or more than one control out.
2874 Node* Node::unique_ctrl_out() const {
2875 Node* ctrl = unique_ctrl_out_or_null();
2876 assert(ctrl != nullptr, "control out is assumed to be unique");
2877 return ctrl;
2878 }
2879
2880 void Node::ensure_control_or_add_prec(Node* c) {
2881 if (in(0) == nullptr) {
2882 set_req(0, c);
2883 } else if (in(0) != c) {
2884 add_prec(c);
2885 }
2886 }
2887
2888 bool Node::is_dead_loop_safe() const {
2889 if (is_Phi()) {
2890 return true;
2891 }
2892 if (is_Proj() && in(0) == nullptr) {
2893 return true;
2894 }
2895 if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
2896 if (!is_Proj()) {
2897 return true;
2898 }
2899 if (in(0)->is_Allocate()) {
2900 return false;
2901 }
2902 // MemNode::can_see_stored_value() peeks through the boxing call
2903 if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
2904 return false;
2905 }
2906 return true;
2907 }
2908 return false;
2909 }
2910
2911 //=============================================================================
2912 //------------------------------yank-------------------------------------------
2913 // Find and remove
2914 void Node_List::yank( Node *n ) {
2915 uint i;
2916 for (i = 0; i < _cnt; i++) {
2917 if (_nodes[i] == n) {
2918 break;
2919 }
2920 }
2921
2922 if (i < _cnt) {
2923 _nodes[i] = _nodes[--_cnt];
2924 }
2925 }
2926
2927 //------------------------------dump-------------------------------------------
2928 void Node_List::dump() const {
2929 #ifndef PRODUCT
2930 for (uint i = 0; i < _cnt; i++) {
2931 if (_nodes[i]) {
2932 tty->print("%5d--> ", i);
2933 _nodes[i]->dump();
2934 }
2935 }
2936 #endif
2937 }
2938
2939 void Node_List::dump_simple() const {
2940 #ifndef PRODUCT
2941 for (uint i = 0; i < _cnt; i++) {
2942 if( _nodes[i] ) {
2943 tty->print(" %d", _nodes[i]->_idx);
2944 } else {
2945 tty->print(" null");
2946 }
2947 }
2948 #endif
2949 }
2950
2951 //=============================================================================
2952 //------------------------------remove-----------------------------------------
2953 void Unique_Node_List::remove(Node* n) {
2954 if (_in_worklist.test(n->_idx)) {
2955 for (uint i = 0; i < size(); i++) {
2956 if (_nodes[i] == n) {
2957 map(i, Node_List::pop());
2958 _in_worklist.remove(n->_idx);
2959 return;
2960 }
2961 }
2962 ShouldNotReachHere();
2963 }
2964 }
2965
2966 //-----------------------remove_useless_nodes----------------------------------
2967 // Remove useless nodes from worklist
2968 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2969 for (uint i = 0; i < size(); ++i) {
2970 Node *n = at(i);
2971 assert( n != nullptr, "Did not expect null entries in worklist");
2972 if (!useful.test(n->_idx)) {
2973 _in_worklist.remove(n->_idx);
2974 map(i, Node_List::pop());
2975 --i; // Visit popped node
2976 // If it was last entry, loop terminates since size() was also reduced
2977 }
2978 }
2979 }
2980
2981 //=============================================================================
2982 void Node_Stack::grow() {
2983 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2984 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2985 size_t max = old_max << 1; // max * 2
2986 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2987 _inode_max = _inodes + max;
2988 _inode_top = _inodes + old_top; // restore _top
2989 }
2990
2991 // Node_Stack is used to map nodes.
2992 Node* Node_Stack::find(uint idx) const {
2993 uint sz = size();
2994 for (uint i = 0; i < sz; i++) {
2995 if (idx == index_at(i)) {
2996 return node_at(i);
2997 }
2998 }
2999 return nullptr;
3000 }
3001
3002 //=============================================================================
3003 uint TypeNode::size_of() const { return sizeof(*this); }
3004 #ifndef PRODUCT
3005 void TypeNode::dump_spec(outputStream *st) const {
3006 if (!Verbose && !WizardMode) {
3007 // standard dump does this in Verbose and WizardMode
3008 st->print(" #"); _type->dump_on(st);
3009 }
3010 }
3011
3012 void TypeNode::dump_compact_spec(outputStream *st) const {
3013 st->print("#");
3014 _type->dump_on(st);
3015 }
3016 #endif
3017 uint TypeNode::hash() const {
3018 return Node::hash() + _type->hash();
3019 }
3020 bool TypeNode::cmp(const Node& n) const {
3021 return Type::equals(_type, n.as_Type()->_type);
3022 }
3023 const Type* TypeNode::bottom_type() const { return _type; }
3024 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
3025
3026 //------------------------------ideal_reg--------------------------------------
3027 uint TypeNode::ideal_reg() const {
3028 return _type->ideal_reg();
3029 }