1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2024, Alibaba Group Holding Limited. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/c2/barrierSetC2.hpp"
29 #include "libadt/vectset.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "opto/ad.hpp"
33 #include "opto/callGenerator.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/cfgnode.hpp"
36 #include "opto/connode.hpp"
37 #include "opto/inlinetypenode.hpp"
38 #include "opto/loopnode.hpp"
39 #include "opto/machnode.hpp"
40 #include "opto/matcher.hpp"
41 #include "opto/node.hpp"
42 #include "opto/opcodes.hpp"
43 #include "opto/regmask.hpp"
44 #include "opto/rootnode.hpp"
45 #include "opto/type.hpp"
46 #include "utilities/copy.hpp"
47 #include "utilities/macros.hpp"
48 #include "utilities/powerOfTwo.hpp"
49 #include "utilities/stringUtils.hpp"
50
51 class RegMask;
52 // #include "phase.hpp"
53 class PhaseTransform;
54 class PhaseGVN;
55
56 // Arena we are currently building Nodes in
57 const uint Node::NotAMachineReg = 0xffff0000;
58
59 #ifndef PRODUCT
60 extern uint nodes_created;
61 #endif
62 #ifdef __clang__
63 #pragma clang diagnostic push
64 #pragma GCC diagnostic ignored "-Wuninitialized"
65 #endif
66
67 #ifdef ASSERT
68
69 //-------------------------- construct_node------------------------------------
70 // Set a breakpoint here to identify where a particular node index is built.
71 void Node::verify_construction() {
72 _debug_orig = nullptr;
73 // The decimal digits of _debug_idx are <compile_id> followed by 10 digits of <_idx>
74 Compile* C = Compile::current();
75 assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
76 uint64_t new_debug_idx = (uint64_t)C->compile_id() * 10000000000 + _idx;
77 set_debug_idx(new_debug_idx);
78 if (!C->phase_optimize_finished()) {
79 // Only check assert during parsing and optimization phase. Skip it while generating code.
80 assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
81 }
82 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (uint64_t)_idx == BreakAtNode)) {
83 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT, _idx, _debug_idx);
84 BREAKPOINT;
85 }
86 #if OPTO_DU_ITERATOR_ASSERT
87 _last_del = nullptr;
88 _del_tick = 0;
89 #endif
90 _hash_lock = 0;
91 }
92
93
94 // #ifdef ASSERT ...
95
96 #if OPTO_DU_ITERATOR_ASSERT
97 void DUIterator_Common::sample(const Node* node) {
98 _vdui = VerifyDUIterators;
99 _node = node;
100 _outcnt = node->_outcnt;
101 _del_tick = node->_del_tick;
102 _last = nullptr;
103 }
104
105 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
106 assert(_node == node, "consistent iterator source");
107 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
108 }
109
110 void DUIterator_Common::verify_resync() {
111 // Ensure that the loop body has just deleted the last guy produced.
112 const Node* node = _node;
113 // Ensure that at least one copy of the last-seen edge was deleted.
114 // Note: It is OK to delete multiple copies of the last-seen edge.
115 // Unfortunately, we have no way to verify that all the deletions delete
116 // that same edge. On this point we must use the Honor System.
117 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
118 assert(node->_last_del == _last, "must have deleted the edge just produced");
119 // We liked this deletion, so accept the resulting outcnt and tick.
120 _outcnt = node->_outcnt;
121 _del_tick = node->_del_tick;
122 }
123
124 void DUIterator_Common::reset(const DUIterator_Common& that) {
125 if (this == &that) return; // ignore assignment to self
126 if (!_vdui) {
127 // We need to initialize everything, overwriting garbage values.
128 _last = that._last;
129 _vdui = that._vdui;
130 }
131 // Note: It is legal (though odd) for an iterator over some node x
132 // to be reassigned to iterate over another node y. Some doubly-nested
133 // progress loops depend on being able to do this.
134 const Node* node = that._node;
135 // Re-initialize everything, except _last.
136 _node = node;
137 _outcnt = node->_outcnt;
138 _del_tick = node->_del_tick;
139 }
140
141 void DUIterator::sample(const Node* node) {
142 DUIterator_Common::sample(node); // Initialize the assertion data.
143 _refresh_tick = 0; // No refreshes have happened, as yet.
144 }
145
146 void DUIterator::verify(const Node* node, bool at_end_ok) {
147 DUIterator_Common::verify(node, at_end_ok);
148 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
149 }
150
151 void DUIterator::verify_increment() {
152 if (_refresh_tick & 1) {
153 // We have refreshed the index during this loop.
154 // Fix up _idx to meet asserts.
155 if (_idx > _outcnt) _idx = _outcnt;
156 }
157 verify(_node, true);
158 }
159
160 void DUIterator::verify_resync() {
161 // Note: We do not assert on _outcnt, because insertions are OK here.
162 DUIterator_Common::verify_resync();
163 // Make sure we are still in sync, possibly with no more out-edges:
164 verify(_node, true);
165 }
166
167 void DUIterator::reset(const DUIterator& that) {
168 if (this == &that) return; // self assignment is always a no-op
169 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
170 assert(that._idx == 0, "assign only the result of Node::outs()");
171 assert(_idx == that._idx, "already assigned _idx");
172 if (!_vdui) {
173 // We need to initialize everything, overwriting garbage values.
174 sample(that._node);
175 } else {
176 DUIterator_Common::reset(that);
177 if (_refresh_tick & 1) {
178 _refresh_tick++; // Clear the "was refreshed" flag.
179 }
180 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
181 }
182 }
183
184 void DUIterator::refresh() {
185 DUIterator_Common::sample(_node); // Re-fetch assertion data.
186 _refresh_tick |= 1; // Set the "was refreshed" flag.
187 }
188
189 void DUIterator::verify_finish() {
190 // If the loop has killed the node, do not require it to re-run.
191 if (_node->_outcnt == 0) _refresh_tick &= ~1;
192 // If this assert triggers, it means that a loop used refresh_out_pos
193 // to re-synch an iteration index, but the loop did not correctly
194 // re-run itself, using a "while (progress)" construct.
195 // This iterator enforces the rule that you must keep trying the loop
196 // until it "runs clean" without any need for refreshing.
197 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
198 }
199
200
201 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
202 DUIterator_Common::verify(node, at_end_ok);
203 Node** out = node->_out;
204 uint cnt = node->_outcnt;
205 assert(cnt == _outcnt, "no insertions allowed");
206 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
207 // This last check is carefully designed to work for NO_OUT_ARRAY.
208 }
209
210 void DUIterator_Fast::verify_limit() {
211 const Node* node = _node;
212 verify(node, true);
213 assert(_outp == node->_out + node->_outcnt, "limit still correct");
214 }
215
216 void DUIterator_Fast::verify_resync() {
217 const Node* node = _node;
218 if (_outp == node->_out + _outcnt) {
219 // Note that the limit imax, not the pointer i, gets updated with the
220 // exact count of deletions. (For the pointer it's always "--i".)
221 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
222 // This is a limit pointer, with a name like "imax".
223 // Fudge the _last field so that the common assert will be happy.
224 _last = (Node*) node->_last_del;
225 DUIterator_Common::verify_resync();
226 } else {
227 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
228 // A normal internal pointer.
229 DUIterator_Common::verify_resync();
230 // Make sure we are still in sync, possibly with no more out-edges:
231 verify(node, true);
232 }
233 }
234
235 void DUIterator_Fast::verify_relimit(uint n) {
236 const Node* node = _node;
237 assert((int)n > 0, "use imax -= n only with a positive count");
238 // This must be a limit pointer, with a name like "imax".
239 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
240 // The reported number of deletions must match what the node saw.
241 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
242 // Fudge the _last field so that the common assert will be happy.
243 _last = (Node*) node->_last_del;
244 DUIterator_Common::verify_resync();
245 }
246
247 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
248 assert(_outp == that._outp, "already assigned _outp");
249 DUIterator_Common::reset(that);
250 }
251
252 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
253 // at_end_ok means the _outp is allowed to underflow by 1
254 _outp += at_end_ok;
255 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
256 _outp -= at_end_ok;
257 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
258 }
259
260 void DUIterator_Last::verify_limit() {
261 // Do not require the limit address to be resynched.
262 //verify(node, true);
263 assert(_outp == _node->_out, "limit still correct");
264 }
265
266 void DUIterator_Last::verify_step(uint num_edges) {
267 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
268 _outcnt -= num_edges;
269 _del_tick += num_edges;
270 // Make sure we are still in sync, possibly with no more out-edges:
271 const Node* node = _node;
272 verify(node, true);
273 assert(node->_last_del == _last, "must have deleted the edge just produced");
274 }
275
276 #endif //OPTO_DU_ITERATOR_ASSERT
277
278
279 #endif //ASSERT
280
281
282 // This constant used to initialize _out may be any non-null value.
283 // The value null is reserved for the top node only.
284 #define NO_OUT_ARRAY ((Node**)-1)
285
286 // Out-of-line code from node constructors.
287 // Executed only when extra debug info. is being passed around.
288 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
289 C->set_node_notes_at(idx, nn);
290 }
291
292 // Shared initialization code.
293 inline int Node::Init(int req) {
294 Compile* C = Compile::current();
295 int idx = C->next_unique();
296 NOT_PRODUCT(_igv_idx = C->next_igv_idx());
297
298 // Allocate memory for the necessary number of edges.
299 if (req > 0) {
300 // Allocate space for _in array to have double alignment.
301 _in = (Node **) ((char *) (C->node_arena()->AmallocWords(req * sizeof(void*))));
302 }
303 // If there are default notes floating around, capture them:
304 Node_Notes* nn = C->default_node_notes();
305 if (nn != nullptr) init_node_notes(C, idx, nn);
306
307 // Note: At this point, C is dead,
308 // and we begin to initialize the new Node.
309
310 _cnt = _max = req;
311 _outcnt = _outmax = 0;
312 _class_id = Class_Node;
313 _flags = 0;
314 _out = NO_OUT_ARRAY;
315 return idx;
316 }
317
318 //------------------------------Node-------------------------------------------
319 // Create a Node, with a given number of required edges.
320 Node::Node(uint req)
321 : _idx(Init(req))
322 #ifdef ASSERT
323 , _parse_idx(_idx)
324 #endif
325 {
326 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
327 debug_only( verify_construction() );
328 NOT_PRODUCT(nodes_created++);
329 if (req == 0) {
330 _in = nullptr;
331 } else {
332 Node** to = _in;
333 for(uint i = 0; i < req; i++) {
334 to[i] = nullptr;
335 }
336 }
337 }
338
339 //------------------------------Node-------------------------------------------
340 Node::Node(Node *n0)
341 : _idx(Init(1))
342 #ifdef ASSERT
343 , _parse_idx(_idx)
344 #endif
345 {
346 debug_only( verify_construction() );
347 NOT_PRODUCT(nodes_created++);
348 assert( is_not_dead(n0), "can not use dead node");
349 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
350 }
351
352 //------------------------------Node-------------------------------------------
353 Node::Node(Node *n0, Node *n1)
354 : _idx(Init(2))
355 #ifdef ASSERT
356 , _parse_idx(_idx)
357 #endif
358 {
359 debug_only( verify_construction() );
360 NOT_PRODUCT(nodes_created++);
361 assert( is_not_dead(n0), "can not use dead node");
362 assert( is_not_dead(n1), "can not use dead node");
363 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
364 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
365 }
366
367 //------------------------------Node-------------------------------------------
368 Node::Node(Node *n0, Node *n1, Node *n2)
369 : _idx(Init(3))
370 #ifdef ASSERT
371 , _parse_idx(_idx)
372 #endif
373 {
374 debug_only( verify_construction() );
375 NOT_PRODUCT(nodes_created++);
376 assert( is_not_dead(n0), "can not use dead node");
377 assert( is_not_dead(n1), "can not use dead node");
378 assert( is_not_dead(n2), "can not use dead node");
379 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
380 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
381 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
382 }
383
384 //------------------------------Node-------------------------------------------
385 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
386 : _idx(Init(4))
387 #ifdef ASSERT
388 , _parse_idx(_idx)
389 #endif
390 {
391 debug_only( verify_construction() );
392 NOT_PRODUCT(nodes_created++);
393 assert( is_not_dead(n0), "can not use dead node");
394 assert( is_not_dead(n1), "can not use dead node");
395 assert( is_not_dead(n2), "can not use dead node");
396 assert( is_not_dead(n3), "can not use dead node");
397 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
398 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
399 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
400 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
401 }
402
403 //------------------------------Node-------------------------------------------
404 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
405 : _idx(Init(5))
406 #ifdef ASSERT
407 , _parse_idx(_idx)
408 #endif
409 {
410 debug_only( verify_construction() );
411 NOT_PRODUCT(nodes_created++);
412 assert( is_not_dead(n0), "can not use dead node");
413 assert( is_not_dead(n1), "can not use dead node");
414 assert( is_not_dead(n2), "can not use dead node");
415 assert( is_not_dead(n3), "can not use dead node");
416 assert( is_not_dead(n4), "can not use dead node");
417 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
418 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
419 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
420 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
421 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
422 }
423
424 //------------------------------Node-------------------------------------------
425 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
426 Node *n4, Node *n5)
427 : _idx(Init(6))
428 #ifdef ASSERT
429 , _parse_idx(_idx)
430 #endif
431 {
432 debug_only( verify_construction() );
433 NOT_PRODUCT(nodes_created++);
434 assert( is_not_dead(n0), "can not use dead node");
435 assert( is_not_dead(n1), "can not use dead node");
436 assert( is_not_dead(n2), "can not use dead node");
437 assert( is_not_dead(n3), "can not use dead node");
438 assert( is_not_dead(n4), "can not use dead node");
439 assert( is_not_dead(n5), "can not use dead node");
440 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
441 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
442 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
443 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
444 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
445 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
446 }
447
448 //------------------------------Node-------------------------------------------
449 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
450 Node *n4, Node *n5, Node *n6)
451 : _idx(Init(7))
452 #ifdef ASSERT
453 , _parse_idx(_idx)
454 #endif
455 {
456 debug_only( verify_construction() );
457 NOT_PRODUCT(nodes_created++);
458 assert( is_not_dead(n0), "can not use dead node");
459 assert( is_not_dead(n1), "can not use dead node");
460 assert( is_not_dead(n2), "can not use dead node");
461 assert( is_not_dead(n3), "can not use dead node");
462 assert( is_not_dead(n4), "can not use dead node");
463 assert( is_not_dead(n5), "can not use dead node");
464 assert( is_not_dead(n6), "can not use dead node");
465 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
466 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
467 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
468 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
469 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
470 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
471 _in[6] = n6; if (n6 != nullptr) n6->add_out((Node *)this);
472 }
473
474 #ifdef __clang__
475 #pragma clang diagnostic pop
476 #endif
477
478
479 //------------------------------clone------------------------------------------
480 // Clone a Node.
481 Node *Node::clone() const {
482 Compile* C = Compile::current();
483 uint s = size_of(); // Size of inherited Node
484 Node *n = (Node*)C->node_arena()->AmallocWords(size_of() + _max*sizeof(Node*));
485 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
486 // Set the new input pointer array
487 n->_in = (Node**)(((char*)n)+s);
488 // Cannot share the old output pointer array, so kill it
489 n->_out = NO_OUT_ARRAY;
490 // And reset the counters to 0
491 n->_outcnt = 0;
492 n->_outmax = 0;
493 // Unlock this guy, since he is not in any hash table.
494 debug_only(n->_hash_lock = 0);
495 // Walk the old node's input list to duplicate its edges
496 uint i;
497 for( i = 0; i < len(); i++ ) {
498 Node *x = in(i);
499 n->_in[i] = x;
500 if (x != nullptr) x->add_out(n);
501 }
502 if (is_macro()) {
503 C->add_macro_node(n);
504 }
505 if (is_expensive()) {
506 C->add_expensive_node(n);
507 }
508 if (for_post_loop_opts_igvn()) {
509 // Don't add cloned node to Compile::_for_post_loop_opts_igvn list automatically.
510 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
511 n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
512 }
513 if (n->is_ParsePredicate()) {
514 C->add_parse_predicate(n->as_ParsePredicate());
515 }
516
517 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
518 bs->register_potential_barrier_node(n);
519
520 n->set_idx(C->next_unique()); // Get new unique index as well
521 NOT_PRODUCT(n->_igv_idx = C->next_igv_idx());
522 debug_only( n->verify_construction() );
523 NOT_PRODUCT(nodes_created++);
524 // Do not patch over the debug_idx of a clone, because it makes it
525 // impossible to break on the clone's moment of creation.
526 //debug_only( n->set_debug_idx( debug_idx() ) );
527
528 C->copy_node_notes_to(n, (Node*) this);
529
530 // MachNode clone
531 uint nopnds;
532 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
533 MachNode *mach = n->as_Mach();
534 MachNode *mthis = this->as_Mach();
535 // Get address of _opnd_array.
536 // It should be the same offset since it is the clone of this node.
537 MachOper **from = mthis->_opnds;
538 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
539 pointer_delta((const void*)from,
540 (const void*)(&mthis->_opnds), 1));
541 mach->_opnds = to;
542 for ( uint i = 0; i < nopnds; ++i ) {
543 to[i] = from[i]->clone();
544 }
545 }
546 if (n->is_Call()) {
547 // CallGenerator is linked to the original node.
548 CallGenerator* cg = n->as_Call()->generator();
549 if (cg != nullptr) {
550 CallGenerator* cloned_cg = cg->with_call_node(n->as_Call());
551 n->as_Call()->set_generator(cloned_cg);
552
553 C->print_inlining_assert_ready();
554 C->print_inlining_move_to(cg);
555 C->print_inlining_update(cloned_cg);
556 }
557 }
558 if (n->is_SafePoint()) {
559 // Scalar replacement and macro expansion might modify the JVMState.
560 // Clone it to make sure it's not shared between SafePointNodes.
561 n->as_SafePoint()->clone_jvms(C);
562 n->as_SafePoint()->clone_replaced_nodes();
563 }
564 if (n->is_InlineType()) {
565 C->add_inline_type(n);
566 }
567 Compile::current()->record_modified_node(n);
568 return n; // Return the clone
569 }
570
571 //---------------------------setup_is_top--------------------------------------
572 // Call this when changing the top node, to reassert the invariants
573 // required by Node::is_top. See Compile::set_cached_top_node.
574 void Node::setup_is_top() {
575 if (this == (Node*)Compile::current()->top()) {
576 // This node has just become top. Kill its out array.
577 _outcnt = _outmax = 0;
578 _out = nullptr; // marker value for top
579 assert(is_top(), "must be top");
580 } else {
581 if (_out == nullptr) _out = NO_OUT_ARRAY;
582 assert(!is_top(), "must not be top");
583 }
584 }
585
586 //------------------------------~Node------------------------------------------
587 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
588 void Node::destruct(PhaseValues* phase) {
589 Compile* compile = (phase != nullptr) ? phase->C : Compile::current();
590 if (phase != nullptr && phase->is_IterGVN()) {
591 phase->is_IterGVN()->_worklist.remove(this);
592 }
593 // If this is the most recently created node, reclaim its index. Otherwise,
594 // record the node as dead to keep liveness information accurate.
595 if ((uint)_idx+1 == compile->unique()) {
596 compile->set_unique(compile->unique()-1);
597 } else {
598 compile->record_dead_node(_idx);
599 }
600 // Clear debug info:
601 Node_Notes* nn = compile->node_notes_at(_idx);
602 if (nn != nullptr) nn->clear();
603 // Walk the input array, freeing the corresponding output edges
604 _cnt = _max; // forget req/prec distinction
605 uint i;
606 for( i = 0; i < _max; i++ ) {
607 set_req(i, nullptr);
608 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
609 }
610 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
611
612 if (is_macro()) {
613 compile->remove_macro_node(this);
614 }
615 if (is_expensive()) {
616 compile->remove_expensive_node(this);
617 }
618 if (is_Opaque4()) {
619 compile->remove_template_assertion_predicate_opaq(this);
620 }
621 if (is_ParsePredicate()) {
622 compile->remove_parse_predicate(as_ParsePredicate());
623 }
624 if (for_post_loop_opts_igvn()) {
625 compile->remove_from_post_loop_opts_igvn(this);
626 }
627 if (is_InlineType()) {
628 compile->remove_inline_type(this);
629 }
630
631 if (is_SafePoint()) {
632 as_SafePoint()->delete_replaced_nodes();
633
634 if (is_CallStaticJava()) {
635 compile->remove_unstable_if_trap(as_CallStaticJava(), false);
636 }
637 }
638 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
639 bs->unregister_potential_barrier_node(this);
640
641 // See if the input array was allocated just prior to the object
642 int edge_size = _max*sizeof(void*);
643 int out_edge_size = _outmax*sizeof(void*);
644 char *in_array = ((char*)_in);
645 char *edge_end = in_array + edge_size;
646 char *out_array = (char*)(_out == NO_OUT_ARRAY? nullptr: _out);
647 int node_size = size_of();
648
649 #ifdef ASSERT
650 // We will not actually delete the storage, but we'll make the node unusable.
651 compile->remove_modified_node(this);
652 *(address*)this = badAddress; // smash the C++ vtbl, probably
653 _in = _out = (Node**) badAddress;
654 _max = _cnt = _outmax = _outcnt = 0;
655 #endif
656
657 // Free the output edge array
658 if (out_edge_size > 0) {
659 compile->node_arena()->Afree(out_array, out_edge_size);
660 }
661
662 // Free the input edge array and the node itself
663 if( edge_end == (char*)this ) {
664 // It was; free the input array and object all in one hit
665 #ifndef ASSERT
666 compile->node_arena()->Afree(in_array, edge_size+node_size);
667 #endif
668 } else {
669 // Free just the input array
670 compile->node_arena()->Afree(in_array, edge_size);
671
672 // Free just the object
673 #ifndef ASSERT
674 compile->node_arena()->Afree(this, node_size);
675 #endif
676 }
677 }
678
679 //------------------------------grow-------------------------------------------
680 // Grow the input array, making space for more edges
681 void Node::grow(uint len) {
682 Arena* arena = Compile::current()->node_arena();
683 uint new_max = _max;
684 if( new_max == 0 ) {
685 _max = 4;
686 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
687 Node** to = _in;
688 to[0] = nullptr;
689 to[1] = nullptr;
690 to[2] = nullptr;
691 to[3] = nullptr;
692 return;
693 }
694 new_max = next_power_of_2(len);
695 // Trimming to limit allows a uint8 to handle up to 255 edges.
696 // Previously I was using only powers-of-2 which peaked at 128 edges.
697 //if( new_max >= limit ) new_max = limit-1;
698 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
699 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // null all new space
700 _max = new_max; // Record new max length
701 // This assertion makes sure that Node::_max is wide enough to
702 // represent the numerical value of new_max.
703 assert(_max == new_max && _max > len, "int width of _max is too small");
704 }
705
706 //-----------------------------out_grow----------------------------------------
707 // Grow the input array, making space for more edges
708 void Node::out_grow( uint len ) {
709 assert(!is_top(), "cannot grow a top node's out array");
710 Arena* arena = Compile::current()->node_arena();
711 uint new_max = _outmax;
712 if( new_max == 0 ) {
713 _outmax = 4;
714 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
715 return;
716 }
717 new_max = next_power_of_2(len);
718 // Trimming to limit allows a uint8 to handle up to 255 edges.
719 // Previously I was using only powers-of-2 which peaked at 128 edges.
720 //if( new_max >= limit ) new_max = limit-1;
721 assert(_out != nullptr && _out != NO_OUT_ARRAY, "out must have sensible value");
722 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
723 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // null all new space
724 _outmax = new_max; // Record new max length
725 // This assertion makes sure that Node::_max is wide enough to
726 // represent the numerical value of new_max.
727 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
728 }
729
730 #ifdef ASSERT
731 //------------------------------is_dead----------------------------------------
732 bool Node::is_dead() const {
733 // Mach and pinch point nodes may look like dead.
734 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
735 return false;
736 for( uint i = 0; i < _max; i++ )
737 if( _in[i] != nullptr )
738 return false;
739 return true;
740 }
741
742 bool Node::is_not_dead(const Node* n) {
743 return n == nullptr || !PhaseIterGVN::is_verify_def_use() || !(n->is_dead());
744 }
745
746 bool Node::is_reachable_from_root() const {
747 ResourceMark rm;
748 Unique_Node_List wq;
749 wq.push((Node*)this);
750 RootNode* root = Compile::current()->root();
751 for (uint i = 0; i < wq.size(); i++) {
752 Node* m = wq.at(i);
753 if (m == root) {
754 return true;
755 }
756 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
757 Node* u = m->fast_out(j);
758 wq.push(u);
759 }
760 }
761 return false;
762 }
763 #endif
764
765 //------------------------------is_unreachable---------------------------------
766 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
767 assert(!is_Mach(), "doesn't work with MachNodes");
768 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != nullptr && in(0)->is_top());
769 }
770
771 //------------------------------add_req----------------------------------------
772 // Add a new required input at the end
773 void Node::add_req( Node *n ) {
774 assert( is_not_dead(n), "can not use dead node");
775
776 // Look to see if I can move precedence down one without reallocating
777 if( (_cnt >= _max) || (in(_max-1) != nullptr) )
778 grow( _max+1 );
779
780 // Find a precedence edge to move
781 if( in(_cnt) != nullptr ) { // Next precedence edge is busy?
782 uint i;
783 for( i=_cnt; i<_max; i++ )
784 if( in(i) == nullptr ) // Find the null at end of prec edge list
785 break; // There must be one, since we grew the array
786 _in[i] = in(_cnt); // Move prec over, making space for req edge
787 }
788 _in[_cnt++] = n; // Stuff over old prec edge
789 if (n != nullptr) n->add_out((Node *)this);
790 Compile::current()->record_modified_node(this);
791 }
792
793 //---------------------------add_req_batch-------------------------------------
794 // Add a new required input at the end
795 void Node::add_req_batch( Node *n, uint m ) {
796 assert( is_not_dead(n), "can not use dead node");
797 // check various edge cases
798 if ((int)m <= 1) {
799 assert((int)m >= 0, "oob");
800 if (m != 0) add_req(n);
801 return;
802 }
803
804 // Look to see if I can move precedence down one without reallocating
805 if( (_cnt+m) > _max || _in[_max-m] )
806 grow( _max+m );
807
808 // Find a precedence edge to move
809 if( _in[_cnt] != nullptr ) { // Next precedence edge is busy?
810 uint i;
811 for( i=_cnt; i<_max; i++ )
812 if( _in[i] == nullptr ) // Find the null at end of prec edge list
813 break; // There must be one, since we grew the array
814 // Slide all the precs over by m positions (assume #prec << m).
815 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
816 }
817
818 // Stuff over the old prec edges
819 for(uint i=0; i<m; i++ ) {
820 _in[_cnt++] = n;
821 }
822
823 // Insert multiple out edges on the node.
824 if (n != nullptr && !n->is_top()) {
825 for(uint i=0; i<m; i++ ) {
826 n->add_out((Node *)this);
827 }
828 }
829 Compile::current()->record_modified_node(this);
830 }
831
832 //------------------------------del_req----------------------------------------
833 // Delete the required edge and compact the edge array
834 void Node::del_req( uint idx ) {
835 assert( idx < _cnt, "oob");
836 assert( !VerifyHashTableKeys || _hash_lock == 0,
837 "remove node from hash table before modifying it");
838 // First remove corresponding def-use edge
839 Node *n = in(idx);
840 if (n != nullptr) n->del_out((Node *)this);
841 _in[idx] = in(--_cnt); // Compact the array
842 // Avoid spec violation: Gap in prec edges.
843 close_prec_gap_at(_cnt);
844 Compile::current()->record_modified_node(this);
845 }
846
847 //------------------------------del_req_ordered--------------------------------
848 // Delete the required edge and compact the edge array with preserved order
849 void Node::del_req_ordered( uint idx ) {
850 assert( idx < _cnt, "oob");
851 assert( !VerifyHashTableKeys || _hash_lock == 0,
852 "remove node from hash table before modifying it");
853 // First remove corresponding def-use edge
854 Node *n = in(idx);
855 if (n != nullptr) n->del_out((Node *)this);
856 if (idx < --_cnt) { // Not last edge ?
857 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
858 }
859 // Avoid spec violation: Gap in prec edges.
860 close_prec_gap_at(_cnt);
861 Compile::current()->record_modified_node(this);
862 }
863
864 //------------------------------ins_req----------------------------------------
865 // Insert a new required input at the end
866 void Node::ins_req( uint idx, Node *n ) {
867 assert( is_not_dead(n), "can not use dead node");
868 add_req(nullptr); // Make space
869 assert( idx < _max, "Must have allocated enough space");
870 // Slide over
871 if(_cnt-idx-1 > 0) {
872 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
873 }
874 _in[idx] = n; // Stuff over old required edge
875 if (n != nullptr) n->add_out((Node *)this); // Add reciprocal def-use edge
876 Compile::current()->record_modified_node(this);
877 }
878
879 //-----------------------------find_edge---------------------------------------
880 int Node::find_edge(Node* n) {
881 for (uint i = 0; i < len(); i++) {
882 if (_in[i] == n) return i;
883 }
884 return -1;
885 }
886
887 //----------------------------replace_edge-------------------------------------
888 int Node::replace_edge(Node* old, Node* neww, PhaseGVN* gvn) {
889 if (old == neww) return 0; // nothing to do
890 uint nrep = 0;
891 for (uint i = 0; i < len(); i++) {
892 if (in(i) == old) {
893 if (i < req()) {
894 if (gvn != nullptr) {
895 set_req_X(i, neww, gvn);
896 } else {
897 set_req(i, neww);
898 }
899 } else {
900 assert(gvn == nullptr || gvn->is_IterGVN() == nullptr, "no support for igvn here");
901 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
902 set_prec(i, neww);
903 }
904 nrep++;
905 }
906 }
907 return nrep;
908 }
909
910 /**
911 * Replace input edges in the range pointing to 'old' node.
912 */
913 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn) {
914 if (old == neww) return 0; // nothing to do
915 uint nrep = 0;
916 for (int i = start; i < end; i++) {
917 if (in(i) == old) {
918 set_req_X(i, neww, gvn);
919 nrep++;
920 }
921 }
922 return nrep;
923 }
924
925 //-------------------------disconnect_inputs-----------------------------------
926 // null out all inputs to eliminate incoming Def-Use edges.
927 void Node::disconnect_inputs(Compile* C) {
928 // the layout of Node::_in
929 // r: a required input, null is allowed
930 // p: a precedence, null values are all at the end
931 // -----------------------------------
932 // |r|...|r|p|...|p|null|...|null|
933 // | |
934 // req() len()
935 // -----------------------------------
936 for (uint i = 0; i < req(); ++i) {
937 if (in(i) != nullptr) {
938 set_req(i, nullptr);
939 }
940 }
941
942 // Remove precedence edges if any exist
943 // Note: Safepoints may have precedence edges, even during parsing
944 for (uint i = len(); i > req(); ) {
945 rm_prec(--i); // no-op if _in[i] is null
946 }
947
948 #ifdef ASSERT
949 // sanity check
950 for (uint i = 0; i < len(); ++i) {
951 assert(_in[i] == nullptr, "disconnect_inputs() failed!");
952 }
953 #endif
954
955 // Node::destruct requires all out edges be deleted first
956 // debug_only(destruct();) // no reuse benefit expected
957 C->record_dead_node(_idx);
958 }
959
960 //-----------------------------uncast---------------------------------------
961 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
962 // Strip away casting. (It is depth-limited.)
963 // Optionally, keep casts with dependencies.
964 Node* Node::uncast(bool keep_deps) const {
965 // Should be inline:
966 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
967 if (is_ConstraintCast()) {
968 return uncast_helper(this, keep_deps);
969 } else {
970 return (Node*) this;
971 }
972 }
973
974 // Find out of current node that matches opcode.
975 Node* Node::find_out_with(int opcode) {
976 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
977 Node* use = fast_out(i);
978 if (use->Opcode() == opcode) {
979 return use;
980 }
981 }
982 return nullptr;
983 }
984
985 // Return true if the current node has an out that matches opcode.
986 bool Node::has_out_with(int opcode) {
987 return (find_out_with(opcode) != nullptr);
988 }
989
990 // Return true if the current node has an out that matches any of the opcodes.
991 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
992 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
993 int opcode = fast_out(i)->Opcode();
994 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
995 return true;
996 }
997 }
998 return false;
999 }
1000
1001
1002 //---------------------------uncast_helper-------------------------------------
1003 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
1004 #ifdef ASSERT
1005 uint depth_count = 0;
1006 const Node* orig_p = p;
1007 #endif
1008
1009 while (true) {
1010 #ifdef ASSERT
1011 if (depth_count >= K) {
1012 orig_p->dump(4);
1013 if (p != orig_p)
1014 p->dump(1);
1015 }
1016 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
1017 #endif
1018 if (p == nullptr || p->req() != 2) {
1019 break;
1020 } else if (p->is_ConstraintCast()) {
1021 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
1022 break; // stop at casts with dependencies
1023 }
1024 p = p->in(1);
1025 } else {
1026 break;
1027 }
1028 }
1029 return (Node*) p;
1030 }
1031
1032 //------------------------------add_prec---------------------------------------
1033 // Add a new precedence input. Precedence inputs are unordered, with
1034 // duplicates removed and nulls packed down at the end.
1035 void Node::add_prec( Node *n ) {
1036 assert( is_not_dead(n), "can not use dead node");
1037
1038 // Check for null at end
1039 if( _cnt >= _max || in(_max-1) )
1040 grow( _max+1 );
1041
1042 // Find a precedence edge to move
1043 uint i = _cnt;
1044 while( in(i) != nullptr ) {
1045 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1046 i++;
1047 }
1048 _in[i] = n; // Stuff prec edge over null
1049 if ( n != nullptr) n->add_out((Node *)this); // Add mirror edge
1050
1051 #ifdef ASSERT
1052 while ((++i)<_max) { assert(_in[i] == nullptr, "spec violation: Gap in prec edges (node %d)", _idx); }
1053 #endif
1054 Compile::current()->record_modified_node(this);
1055 }
1056
1057 //------------------------------rm_prec----------------------------------------
1058 // Remove a precedence input. Precedence inputs are unordered, with
1059 // duplicates removed and nulls packed down at the end.
1060 void Node::rm_prec( uint j ) {
1061 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1062 assert(j >= _cnt, "not a precedence edge");
1063 if (_in[j] == nullptr) return; // Avoid spec violation: Gap in prec edges.
1064 _in[j]->del_out((Node *)this);
1065 close_prec_gap_at(j);
1066 Compile::current()->record_modified_node(this);
1067 }
1068
1069 //------------------------------size_of----------------------------------------
1070 uint Node::size_of() const { return sizeof(*this); }
1071
1072 //------------------------------ideal_reg--------------------------------------
1073 uint Node::ideal_reg() const { return 0; }
1074
1075 //------------------------------jvms-------------------------------------------
1076 JVMState* Node::jvms() const { return nullptr; }
1077
1078 #ifdef ASSERT
1079 //------------------------------jvms-------------------------------------------
1080 bool Node::verify_jvms(const JVMState* using_jvms) const {
1081 for (JVMState* jvms = this->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1082 if (jvms == using_jvms) return true;
1083 }
1084 return false;
1085 }
1086
1087 //------------------------------init_NodeProperty------------------------------
1088 void Node::init_NodeProperty() {
1089 assert(_max_classes <= max_juint, "too many NodeProperty classes");
1090 assert(max_flags() <= max_juint, "too many NodeProperty flags");
1091 }
1092
1093 //-----------------------------max_flags---------------------------------------
1094 juint Node::max_flags() {
1095 return (PD::_last_flag << 1) - 1; // allow flags combination
1096 }
1097 #endif
1098
1099 //------------------------------format-----------------------------------------
1100 // Print as assembly
1101 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1102 //------------------------------emit-------------------------------------------
1103 // Emit bytes using C2_MacroAssembler
1104 void Node::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {}
1105 //------------------------------size-------------------------------------------
1106 // Size of instruction in bytes
1107 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1108
1109 //------------------------------CFG Construction-------------------------------
1110 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1111 // Goto and Return.
1112 const Node *Node::is_block_proj() const { return nullptr; }
1113
1114 // Minimum guaranteed type
1115 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1116
1117
1118 //------------------------------raise_bottom_type------------------------------
1119 // Get the worst-case Type output for this Node.
1120 void Node::raise_bottom_type(const Type* new_type) {
1121 if (is_Type()) {
1122 TypeNode *n = this->as_Type();
1123 if (VerifyAliases) {
1124 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1125 }
1126 n->set_type(new_type);
1127 } else if (is_Load()) {
1128 LoadNode *n = this->as_Load();
1129 if (VerifyAliases) {
1130 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1131 }
1132 n->set_type(new_type);
1133 }
1134 }
1135
1136 //------------------------------Identity---------------------------------------
1137 // Return a node that the given node is equivalent to.
1138 Node* Node::Identity(PhaseGVN* phase) {
1139 return this; // Default to no identities
1140 }
1141
1142 //------------------------------Value------------------------------------------
1143 // Compute a new Type for a node using the Type of the inputs.
1144 const Type* Node::Value(PhaseGVN* phase) const {
1145 return bottom_type(); // Default to worst-case Type
1146 }
1147
1148 //------------------------------Ideal------------------------------------------
1149 //
1150 // 'Idealize' the graph rooted at this Node.
1151 //
1152 // In order to be efficient and flexible there are some subtle invariants
1153 // these Ideal calls need to hold. Running with '-XX:VerifyIterativeGVN=1' checks
1154 // these invariants, although its too slow to have on by default. If you are
1155 // hacking an Ideal call, be sure to test with '-XX:VerifyIterativeGVN=1'
1156 //
1157 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1158 // pointer. If ANY change is made, it must return the root of the reshaped
1159 // graph - even if the root is the same Node. Example: swapping the inputs
1160 // to an AddINode gives the same answer and same root, but you still have to
1161 // return the 'this' pointer instead of null.
1162 //
1163 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1164 // Identity call to return an old Node; basically if Identity can find
1165 // another Node have the Ideal call make no change and return null.
1166 // Example: AddINode::Ideal must check for add of zero; in this case it
1167 // returns null instead of doing any graph reshaping.
1168 //
1169 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1170 // sharing there may be other users of the old Nodes relying on their current
1171 // semantics. Modifying them will break the other users.
1172 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1173 // "X+3" unchanged in case it is shared.
1174 //
1175 // If you modify the 'this' pointer's inputs, you should use
1176 // 'set_req'. If you are making a new Node (either as the new root or
1177 // some new internal piece) you may use 'init_req' to set the initial
1178 // value. You can make a new Node with either 'new' or 'clone'. In
1179 // either case, def-use info is correctly maintained.
1180 //
1181 // Example: reshape "(X+3)+4" into "X+7":
1182 // set_req(1, in(1)->in(1));
1183 // set_req(2, phase->intcon(7));
1184 // return this;
1185 // Example: reshape "X*4" into "X<<2"
1186 // return new LShiftINode(in(1), phase->intcon(2));
1187 //
1188 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1189 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1190 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1191 // return new AddINode(shift, in(1));
1192 //
1193 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1194 // These forms are faster than 'phase->transform(new ConNode())' and Do
1195 // The Right Thing with def-use info.
1196 //
1197 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1198 // graph uses the 'this' Node it must be the root. If you want a Node with
1199 // the same Opcode as the 'this' pointer use 'clone'.
1200 //
1201 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1202 return nullptr; // Default to being Ideal already
1203 }
1204
1205 // Some nodes have specific Ideal subgraph transformations only if they are
1206 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1207 // for the transformations to happen.
1208 bool Node::has_special_unique_user() const {
1209 assert(outcnt() == 1, "match only for unique out");
1210 Node* n = unique_out();
1211 int op = Opcode();
1212 if (this->is_Store()) {
1213 // Condition for back-to-back stores folding.
1214 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1215 } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1216 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1217 return n->Opcode() == Op_MemBarAcquire;
1218 } else if (op == Op_AddL) {
1219 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1220 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1221 } else if (op == Op_SubI || op == Op_SubL) {
1222 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1223 return n->Opcode() == op && n->in(2) == this;
1224 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1225 // See IfProjNode::Identity()
1226 return true;
1227 } else if ((is_IfFalse() || is_IfTrue()) && n->is_If()) {
1228 // See IfNode::fold_compares
1229 return true;
1230 } else {
1231 return false;
1232 }
1233 };
1234
1235 //--------------------------find_exact_control---------------------------------
1236 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1237 Node* Node::find_exact_control(Node* ctrl) {
1238 if (ctrl == nullptr && this->is_Region())
1239 ctrl = this->as_Region()->is_copy();
1240
1241 if (ctrl != nullptr && ctrl->is_CatchProj()) {
1242 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1243 ctrl = ctrl->in(0);
1244 if (ctrl != nullptr && !ctrl->is_top())
1245 ctrl = ctrl->in(0);
1246 }
1247
1248 if (ctrl != nullptr && ctrl->is_Proj())
1249 ctrl = ctrl->in(0);
1250
1251 return ctrl;
1252 }
1253
1254 //--------------------------dominates------------------------------------------
1255 // Helper function for MemNode::all_controls_dominate().
1256 // Check if 'this' control node dominates or equal to 'sub' control node.
1257 // We already know that if any path back to Root or Start reaches 'this',
1258 // then all paths so, so this is a simple search for one example,
1259 // not an exhaustive search for a counterexample.
1260 Node::DomResult Node::dominates(Node* sub, Node_List &nlist) {
1261 assert(this->is_CFG(), "expecting control");
1262 assert(sub != nullptr && sub->is_CFG(), "expecting control");
1263
1264 // detect dead cycle without regions
1265 int iterations_without_region_limit = DominatorSearchLimit;
1266
1267 Node* orig_sub = sub;
1268 Node* dom = this;
1269 bool met_dom = false;
1270 nlist.clear();
1271
1272 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1273 // After seeing 'dom', continue up to Root or Start.
1274 // If we hit a region (backward split point), it may be a loop head.
1275 // Keep going through one of the region's inputs. If we reach the
1276 // same region again, go through a different input. Eventually we
1277 // will either exit through the loop head, or give up.
1278 // (If we get confused, break out and return a conservative 'false'.)
1279 while (sub != nullptr) {
1280 if (sub->is_top()) {
1281 // Conservative answer for dead code.
1282 return DomResult::EncounteredDeadCode;
1283 }
1284 if (sub == dom) {
1285 if (nlist.size() == 0) {
1286 // No Region nodes except loops were visited before and the EntryControl
1287 // path was taken for loops: it did not walk in a cycle.
1288 return DomResult::Dominate;
1289 } else if (met_dom) {
1290 break; // already met before: walk in a cycle
1291 } else {
1292 // Region nodes were visited. Continue walk up to Start or Root
1293 // to make sure that it did not walk in a cycle.
1294 met_dom = true; // first time meet
1295 iterations_without_region_limit = DominatorSearchLimit; // Reset
1296 }
1297 }
1298 if (sub->is_Start() || sub->is_Root()) {
1299 // Success if we met 'dom' along a path to Start or Root.
1300 // We assume there are no alternative paths that avoid 'dom'.
1301 // (This assumption is up to the caller to ensure!)
1302 return met_dom ? DomResult::Dominate : DomResult::NotDominate;
1303 }
1304 Node* up = sub->in(0);
1305 // Normalize simple pass-through regions and projections:
1306 up = sub->find_exact_control(up);
1307 // If sub == up, we found a self-loop. Try to push past it.
1308 if (sub == up && sub->is_Loop()) {
1309 // Take loop entry path on the way up to 'dom'.
1310 up = sub->in(1); // in(LoopNode::EntryControl);
1311 } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1312 // Take in(1) path on the way up to 'dom' for regions with only one input
1313 up = sub->in(1);
1314 } else if (sub == up && sub->is_Region()) {
1315 // Try both paths for Regions with 2 input paths (it may be a loop head).
1316 // It could give conservative 'false' answer without information
1317 // which region's input is the entry path.
1318 iterations_without_region_limit = DominatorSearchLimit; // Reset
1319
1320 bool region_was_visited_before = false;
1321 // Was this Region node visited before?
1322 // If so, we have reached it because we accidentally took a
1323 // loop-back edge from 'sub' back into the body of the loop,
1324 // and worked our way up again to the loop header 'sub'.
1325 // So, take the first unexplored path on the way up to 'dom'.
1326 for (int j = nlist.size() - 1; j >= 0; j--) {
1327 intptr_t ni = (intptr_t)nlist.at(j);
1328 Node* visited = (Node*)(ni & ~1);
1329 bool visited_twice_already = ((ni & 1) != 0);
1330 if (visited == sub) {
1331 if (visited_twice_already) {
1332 // Visited 2 paths, but still stuck in loop body. Give up.
1333 return DomResult::NotDominate;
1334 }
1335 // The Region node was visited before only once.
1336 // (We will repush with the low bit set, below.)
1337 nlist.remove(j);
1338 // We will find a new edge and re-insert.
1339 region_was_visited_before = true;
1340 break;
1341 }
1342 }
1343
1344 // Find an incoming edge which has not been seen yet; walk through it.
1345 assert(up == sub, "");
1346 uint skip = region_was_visited_before ? 1 : 0;
1347 for (uint i = 1; i < sub->req(); i++) {
1348 Node* in = sub->in(i);
1349 if (in != nullptr && !in->is_top() && in != sub) {
1350 if (skip == 0) {
1351 up = in;
1352 break;
1353 }
1354 --skip; // skip this nontrivial input
1355 }
1356 }
1357
1358 // Set 0 bit to indicate that both paths were taken.
1359 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1360 }
1361
1362 if (up == sub) {
1363 break; // some kind of tight cycle
1364 }
1365 if (up == orig_sub && met_dom) {
1366 // returned back after visiting 'dom'
1367 break; // some kind of cycle
1368 }
1369 if (--iterations_without_region_limit < 0) {
1370 break; // dead cycle
1371 }
1372 sub = up;
1373 }
1374
1375 // Did not meet Root or Start node in pred. chain.
1376 return DomResult::NotDominate;
1377 }
1378
1379 //------------------------------remove_dead_region-----------------------------
1380 // This control node is dead. Follow the subgraph below it making everything
1381 // using it dead as well. This will happen normally via the usual IterGVN
1382 // worklist but this call is more efficient. Do not update use-def info
1383 // inside the dead region, just at the borders.
1384 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1385 // Con's are a popular node to re-hit in the hash table again.
1386 if( dead->is_Con() ) return;
1387
1388 ResourceMark rm;
1389 Node_List nstack;
1390 VectorSet dead_set; // notify uses only once
1391
1392 Node *top = igvn->C->top();
1393 nstack.push(dead);
1394 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1395
1396 while (nstack.size() > 0) {
1397 dead = nstack.pop();
1398 if (!dead_set.test_set(dead->_idx)) {
1399 // If dead has any live uses, those are now still attached. Notify them before we lose them.
1400 igvn->add_users_to_worklist(dead);
1401 }
1402 if (dead->Opcode() == Op_SafePoint) {
1403 dead->as_SafePoint()->disconnect_from_root(igvn);
1404 }
1405 if (dead->outcnt() > 0) {
1406 // Keep dead node on stack until all uses are processed.
1407 nstack.push(dead);
1408 // For all Users of the Dead... ;-)
1409 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1410 Node* use = dead->last_out(k);
1411 igvn->hash_delete(use); // Yank from hash table prior to mod
1412 if (use->in(0) == dead) { // Found another dead node
1413 assert (!use->is_Con(), "Control for Con node should be Root node.");
1414 use->set_req(0, top); // Cut dead edge to prevent processing
1415 nstack.push(use); // the dead node again.
1416 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1417 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1418 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1419 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1420 use->set_req(0, top); // Cut self edge
1421 nstack.push(use);
1422 } else { // Else found a not-dead user
1423 // Dead if all inputs are top or null
1424 bool dead_use = !use->is_Root(); // Keep empty graph alive
1425 for (uint j = 1; j < use->req(); j++) {
1426 Node* in = use->in(j);
1427 if (in == dead) { // Turn all dead inputs into TOP
1428 use->set_req(j, top);
1429 } else if (in != nullptr && !in->is_top()) {
1430 dead_use = false;
1431 }
1432 }
1433 if (dead_use) {
1434 if (use->is_Region()) {
1435 use->set_req(0, top); // Cut self edge
1436 }
1437 nstack.push(use);
1438 } else {
1439 igvn->_worklist.push(use);
1440 }
1441 }
1442 // Refresh the iterator, since any number of kills might have happened.
1443 k = dead->last_outs(kmin);
1444 }
1445 } else { // (dead->outcnt() == 0)
1446 // Done with outputs.
1447 igvn->hash_delete(dead);
1448 igvn->_worklist.remove(dead);
1449 igvn->set_type(dead, Type::TOP);
1450 // Kill all inputs to the dead guy
1451 for (uint i=0; i < dead->req(); i++) {
1452 Node *n = dead->in(i); // Get input to dead guy
1453 if (n != nullptr && !n->is_top()) { // Input is valid?
1454 dead->set_req(i, top); // Smash input away
1455 if (n->outcnt() == 0) { // Input also goes dead?
1456 if (!n->is_Con())
1457 nstack.push(n); // Clear it out as well
1458 } else if (n->outcnt() == 1 &&
1459 n->has_special_unique_user()) {
1460 igvn->add_users_to_worklist( n );
1461 } else if (n->outcnt() <= 2 && n->is_Store()) {
1462 // Push store's uses on worklist to enable folding optimization for
1463 // store/store and store/load to the same address.
1464 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1465 // and remove_globally_dead_node().
1466 igvn->add_users_to_worklist( n );
1467 } else {
1468 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1469 }
1470 }
1471 }
1472 igvn->C->remove_useless_node(dead);
1473 } // (dead->outcnt() == 0)
1474 } // while (nstack.size() > 0) for outputs
1475 return;
1476 }
1477
1478 //------------------------------remove_dead_region-----------------------------
1479 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1480 Node *n = in(0);
1481 if( !n ) return false;
1482 // Lost control into this guy? I.e., it became unreachable?
1483 // Aggressively kill all unreachable code.
1484 if (can_reshape && n->is_top()) {
1485 kill_dead_code(this, phase->is_IterGVN());
1486 return false; // Node is dead.
1487 }
1488
1489 if( n->is_Region() && n->as_Region()->is_copy() ) {
1490 Node *m = n->nonnull_req();
1491 set_req(0, m);
1492 return true;
1493 }
1494 return false;
1495 }
1496
1497 //------------------------------hash-------------------------------------------
1498 // Hash function over Nodes.
1499 uint Node::hash() const {
1500 uint sum = 0;
1501 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1502 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded nulls
1503 return (sum>>2) + _cnt + Opcode();
1504 }
1505
1506 //------------------------------cmp--------------------------------------------
1507 // Compare special parts of simple Nodes
1508 bool Node::cmp( const Node &n ) const {
1509 return true; // Must be same
1510 }
1511
1512 //------------------------------rematerialize-----------------------------------
1513 // Should we clone rather than spill this instruction?
1514 bool Node::rematerialize() const {
1515 if ( is_Mach() )
1516 return this->as_Mach()->rematerialize();
1517 else
1518 return (_flags & Flag_rematerialize) != 0;
1519 }
1520
1521 //------------------------------needs_anti_dependence_check---------------------
1522 // Nodes which use memory without consuming it, hence need antidependences.
1523 bool Node::needs_anti_dependence_check() const {
1524 if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1525 return false;
1526 }
1527 return in(1)->bottom_type()->has_memory();
1528 }
1529
1530 // Get an integer constant from a ConNode (or CastIINode).
1531 // Return a default value if there is no apparent constant here.
1532 const TypeInt* Node::find_int_type() const {
1533 if (this->is_Type()) {
1534 return this->as_Type()->type()->isa_int();
1535 } else if (this->is_Con()) {
1536 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1537 return this->bottom_type()->isa_int();
1538 }
1539 return nullptr;
1540 }
1541
1542 const TypeInteger* Node::find_integer_type(BasicType bt) const {
1543 if (this->is_Type()) {
1544 return this->as_Type()->type()->isa_integer(bt);
1545 } else if (this->is_Con()) {
1546 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1547 return this->bottom_type()->isa_integer(bt);
1548 }
1549 return nullptr;
1550 }
1551
1552 // Get a pointer constant from a ConstNode.
1553 // Returns the constant if it is a pointer ConstNode
1554 intptr_t Node::get_ptr() const {
1555 assert( Opcode() == Op_ConP, "" );
1556 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1557 }
1558
1559 // Get a narrow oop constant from a ConNNode.
1560 intptr_t Node::get_narrowcon() const {
1561 assert( Opcode() == Op_ConN, "" );
1562 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1563 }
1564
1565 // Get a long constant from a ConNode.
1566 // Return a default value if there is no apparent constant here.
1567 const TypeLong* Node::find_long_type() const {
1568 if (this->is_Type()) {
1569 return this->as_Type()->type()->isa_long();
1570 } else if (this->is_Con()) {
1571 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1572 return this->bottom_type()->isa_long();
1573 }
1574 return nullptr;
1575 }
1576
1577
1578 /**
1579 * Return a ptr type for nodes which should have it.
1580 */
1581 const TypePtr* Node::get_ptr_type() const {
1582 const TypePtr* tp = this->bottom_type()->make_ptr();
1583 #ifdef ASSERT
1584 if (tp == nullptr) {
1585 this->dump(1);
1586 assert((tp != nullptr), "unexpected node type");
1587 }
1588 #endif
1589 return tp;
1590 }
1591
1592 // Get a double constant from a ConstNode.
1593 // Returns the constant if it is a double ConstNode
1594 jdouble Node::getd() const {
1595 assert( Opcode() == Op_ConD, "" );
1596 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1597 }
1598
1599 // Get a float constant from a ConstNode.
1600 // Returns the constant if it is a float ConstNode
1601 jfloat Node::getf() const {
1602 assert( Opcode() == Op_ConF, "" );
1603 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1604 }
1605
1606 #ifndef PRODUCT
1607
1608 // Call this from debugger:
1609 Node* old_root() {
1610 Matcher* matcher = Compile::current()->matcher();
1611 if (matcher != nullptr) {
1612 Node* new_root = Compile::current()->root();
1613 Node* old_root = matcher->find_old_node(new_root);
1614 if (old_root != nullptr) {
1615 return old_root;
1616 }
1617 }
1618 tty->print("old_root: not found.\n");
1619 return nullptr;
1620 }
1621
1622 // BFS traverse all reachable nodes from start, call callback on them
1623 template <typename Callback>
1624 void visit_nodes(Node* start, Callback callback, bool traverse_output, bool only_ctrl) {
1625 Unique_Mixed_Node_List worklist;
1626 worklist.add(start);
1627 for (uint i = 0; i < worklist.size(); i++) {
1628 Node* n = worklist[i];
1629 callback(n);
1630 for (uint i = 0; i < n->len(); i++) {
1631 if (!only_ctrl || n->is_Region() || (n->Opcode() == Op_Root) || (i == TypeFunc::Control)) {
1632 // If only_ctrl is set: Add regions, the root node, or control inputs only
1633 worklist.add(n->in(i));
1634 }
1635 }
1636 if (traverse_output && !only_ctrl) {
1637 for (uint i = 0; i < n->outcnt(); i++) {
1638 worklist.add(n->raw_out(i));
1639 }
1640 }
1641 }
1642 }
1643
1644 // BFS traverse from start, return node with idx
1645 static Node* find_node_by_idx(Node* start, uint idx, bool traverse_output, bool only_ctrl) {
1646 ResourceMark rm;
1647 Node* result = nullptr;
1648 auto callback = [&] (Node* n) {
1649 if (n->_idx == idx) {
1650 if (result != nullptr) {
1651 tty->print("find_node_by_idx: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1652 (uintptr_t)result, (uintptr_t)n, idx);
1653 }
1654 result = n;
1655 }
1656 };
1657 visit_nodes(start, callback, traverse_output, only_ctrl);
1658 return result;
1659 }
1660
1661 static int node_idx_cmp(const Node** n1, const Node** n2) {
1662 return (*n1)->_idx - (*n2)->_idx;
1663 }
1664
1665 static void find_nodes_by_name(Node* start, const char* name) {
1666 ResourceMark rm;
1667 GrowableArray<const Node*> ns;
1668 auto callback = [&] (const Node* n) {
1669 if (StringUtils::is_star_match(name, n->Name())) {
1670 ns.push(n);
1671 }
1672 };
1673 visit_nodes(start, callback, true, false);
1674 ns.sort(node_idx_cmp);
1675 for (int i = 0; i < ns.length(); i++) {
1676 ns.at(i)->dump();
1677 }
1678 }
1679
1680 static void find_nodes_by_dump(Node* start, const char* pattern) {
1681 ResourceMark rm;
1682 GrowableArray<const Node*> ns;
1683 auto callback = [&] (const Node* n) {
1684 stringStream stream;
1685 n->dump("", false, &stream);
1686 if (StringUtils::is_star_match(pattern, stream.base())) {
1687 ns.push(n);
1688 }
1689 };
1690 visit_nodes(start, callback, true, false);
1691 ns.sort(node_idx_cmp);
1692 for (int i = 0; i < ns.length(); i++) {
1693 ns.at(i)->dump();
1694 }
1695 }
1696
1697 // call from debugger: find node with name pattern in new/current graph
1698 // name can contain "*" in match pattern to match any characters
1699 // the matching is case insensitive
1700 void find_nodes_by_name(const char* name) {
1701 Node* root = Compile::current()->root();
1702 find_nodes_by_name(root, name);
1703 }
1704
1705 // call from debugger: find node with name pattern in old graph
1706 // name can contain "*" in match pattern to match any characters
1707 // the matching is case insensitive
1708 void find_old_nodes_by_name(const char* name) {
1709 Node* root = old_root();
1710 find_nodes_by_name(root, name);
1711 }
1712
1713 // call from debugger: find node with dump pattern in new/current graph
1714 // can contain "*" in match pattern to match any characters
1715 // the matching is case insensitive
1716 void find_nodes_by_dump(const char* pattern) {
1717 Node* root = Compile::current()->root();
1718 find_nodes_by_dump(root, pattern);
1719 }
1720
1721 // call from debugger: find node with name pattern in old graph
1722 // can contain "*" in match pattern to match any characters
1723 // the matching is case insensitive
1724 void find_old_nodes_by_dump(const char* pattern) {
1725 Node* root = old_root();
1726 find_nodes_by_dump(root, pattern);
1727 }
1728
1729 // Call this from debugger, search in same graph as n:
1730 Node* find_node(Node* n, const int idx) {
1731 return n->find(idx);
1732 }
1733
1734 // Call this from debugger, search in new nodes:
1735 Node* find_node(const int idx) {
1736 return Compile::current()->root()->find(idx);
1737 }
1738
1739 // Call this from debugger, search in old nodes:
1740 Node* find_old_node(const int idx) {
1741 Node* root = old_root();
1742 return (root == nullptr) ? nullptr : root->find(idx);
1743 }
1744
1745 // Call this from debugger, search in same graph as n:
1746 Node* find_ctrl(Node* n, const int idx) {
1747 return n->find_ctrl(idx);
1748 }
1749
1750 // Call this from debugger, search in new nodes:
1751 Node* find_ctrl(const int idx) {
1752 return Compile::current()->root()->find_ctrl(idx);
1753 }
1754
1755 // Call this from debugger, search in old nodes:
1756 Node* find_old_ctrl(const int idx) {
1757 Node* root = old_root();
1758 return (root == nullptr) ? nullptr : root->find_ctrl(idx);
1759 }
1760
1761 //------------------------------find_ctrl--------------------------------------
1762 // Find an ancestor to this node in the control history with given _idx
1763 Node* Node::find_ctrl(int idx) {
1764 return find(idx, true);
1765 }
1766
1767 //------------------------------find-------------------------------------------
1768 // Tries to find the node with the index |idx| starting from this node. If idx is negative,
1769 // the search also includes forward (out) edges. Returns null if not found.
1770 // If only_ctrl is set, the search will only be done on control nodes. Returns null if
1771 // not found or if the node to be found is not a control node (search will not find it).
1772 Node* Node::find(const int idx, bool only_ctrl) {
1773 ResourceMark rm;
1774 return find_node_by_idx(this, abs(idx), (idx < 0), only_ctrl);
1775 }
1776
1777 class PrintBFS {
1778 public:
1779 PrintBFS(const Node* start, const int max_distance, const Node* target, const char* options, outputStream* st)
1780 : _start(start), _max_distance(max_distance), _target(target), _options(options), _output(st),
1781 _dcc(this), _info_uid(cmpkey, hashkey) {}
1782
1783 void run();
1784 private:
1785 // pipeline steps
1786 bool configure();
1787 void collect();
1788 void select();
1789 void select_all();
1790 void select_all_paths();
1791 void select_shortest_path();
1792 void sort();
1793 void print();
1794
1795 // inputs
1796 const Node* _start;
1797 const int _max_distance;
1798 const Node* _target;
1799 const char* _options;
1800 outputStream* _output;
1801
1802 // options
1803 bool _traverse_inputs = false;
1804 bool _traverse_outputs = false;
1805 struct Filter {
1806 bool _control = false;
1807 bool _memory = false;
1808 bool _data = false;
1809 bool _mixed = false;
1810 bool _other = false;
1811 bool is_empty() const {
1812 return !(_control || _memory || _data || _mixed || _other);
1813 }
1814 void set_all() {
1815 _control = true;
1816 _memory = true;
1817 _data = true;
1818 _mixed = true;
1819 _other = true;
1820 }
1821 // Check if the filter accepts the node. Go by the type categories, but also all CFG nodes
1822 // are considered to have control.
1823 bool accepts(const Node* n) {
1824 const Type* t = n->bottom_type();
1825 return ( _data && t->has_category(Type::Category::Data) ) ||
1826 ( _memory && t->has_category(Type::Category::Memory) ) ||
1827 ( _mixed && t->has_category(Type::Category::Mixed) ) ||
1828 ( _control && (t->has_category(Type::Category::Control) || n->is_CFG()) ) ||
1829 ( _other && t->has_category(Type::Category::Other) );
1830 }
1831 };
1832 Filter _filter_visit;
1833 Filter _filter_boundary;
1834 bool _sort_idx = false;
1835 bool _all_paths = false;
1836 bool _use_color = false;
1837 bool _print_blocks = false;
1838 bool _print_old = false;
1839 bool _dump_only = false;
1840 void print_options_help(bool print_examples);
1841 bool parse_options();
1842
1843 public:
1844 class DumpConfigColored : public Node::DumpConfig {
1845 public:
1846 DumpConfigColored(PrintBFS* bfs) : _bfs(bfs) {};
1847 virtual void pre_dump(outputStream* st, const Node* n);
1848 virtual void post_dump(outputStream* st);
1849 private:
1850 PrintBFS* _bfs;
1851 };
1852 private:
1853 DumpConfigColored _dcc;
1854
1855 // node info
1856 static Node* old_node(const Node* n); // mach node -> prior IR node
1857 void print_node_idx(const Node* n);
1858 void print_block_id(const Block* b);
1859 void print_node_block(const Node* n); // _pre_order, head idx, _idom, _dom_depth
1860
1861 // traversal data structures
1862 GrowableArray<const Node*> _worklist; // BFS queue
1863 void maybe_traverse(const Node* src, const Node* dst);
1864
1865 // node info annotation
1866 class Info {
1867 public:
1868 Info() : Info(nullptr, 0) {};
1869 Info(const Node* node, int distance)
1870 : _node(node), _distance_from_start(distance) {};
1871 const Node* node() const { return _node; };
1872 int distance() const { return _distance_from_start; };
1873 int distance_from_target() const { return _distance_from_target; }
1874 void set_distance_from_target(int d) { _distance_from_target = d; }
1875 GrowableArray<const Node*> edge_bwd; // pointing toward _start
1876 bool is_marked() const { return _mark; } // marked to keep during select
1877 void set_mark() { _mark = true; }
1878 private:
1879 const Node* _node;
1880 int _distance_from_start; // distance from _start
1881 int _distance_from_target = 0; // distance from _target if _all_paths
1882 bool _mark = false;
1883 };
1884 Dict _info_uid; // Node -> uid
1885 GrowableArray<Info> _info; // uid -> info
1886
1887 Info* find_info(const Node* n) {
1888 size_t uid = (size_t)_info_uid[n];
1889 if (uid == 0) {
1890 return nullptr;
1891 }
1892 return &_info.at((int)uid);
1893 }
1894
1895 void make_info(const Node* node, const int distance) {
1896 assert(find_info(node) == nullptr, "node does not yet have info");
1897 size_t uid = _info.length() + 1;
1898 _info_uid.Insert((void*)node, (void*)uid);
1899 _info.at_put_grow((int)uid, Info(node, distance));
1900 assert(find_info(node)->node() == node, "stored correct node");
1901 };
1902
1903 // filled by sort, printed by print
1904 GrowableArray<const Node*> _print_list;
1905
1906 // print header + node table
1907 void print_header() const;
1908 void print_node(const Node* n);
1909 };
1910
1911 void PrintBFS::run() {
1912 if (!configure()) {
1913 return;
1914 }
1915 collect();
1916 select();
1917 sort();
1918 print();
1919 }
1920
1921 // set up configuration for BFS and print
1922 bool PrintBFS::configure() {
1923 if (_max_distance < 0) {
1924 _output->print_cr("dump_bfs: max_distance must be non-negative!");
1925 return false;
1926 }
1927 return parse_options();
1928 }
1929
1930 // BFS traverse according to configuration, fill worklist and info
1931 void PrintBFS::collect() {
1932 maybe_traverse(_start, _start);
1933 int pos = 0;
1934 while (pos < _worklist.length()) {
1935 const Node* n = _worklist.at(pos++); // next node to traverse
1936 Info* info = find_info(n);
1937 if (!_filter_visit.accepts(n) && n != _start) {
1938 continue; // we hit boundary, do not traverse further
1939 }
1940 if (n != _start && n->is_Root()) {
1941 continue; // traversing through root node would lead to unrelated nodes
1942 }
1943 if (_traverse_inputs && _max_distance > info->distance()) {
1944 for (uint i = 0; i < n->req(); i++) {
1945 maybe_traverse(n, n->in(i));
1946 }
1947 }
1948 if (_traverse_outputs && _max_distance > info->distance()) {
1949 for (uint i = 0; i < n->outcnt(); i++) {
1950 maybe_traverse(n, n->raw_out(i));
1951 }
1952 }
1953 }
1954 }
1955
1956 // go through work list, mark those that we want to print
1957 void PrintBFS::select() {
1958 if (_target == nullptr ) {
1959 select_all();
1960 } else {
1961 if (find_info(_target) == nullptr) {
1962 _output->print_cr("Could not find target in BFS.");
1963 return;
1964 }
1965 if (_all_paths) {
1966 select_all_paths();
1967 } else {
1968 select_shortest_path();
1969 }
1970 }
1971 }
1972
1973 // take all nodes from BFS
1974 void PrintBFS::select_all() {
1975 for (int i = 0; i < _worklist.length(); i++) {
1976 const Node* n = _worklist.at(i);
1977 Info* info = find_info(n);
1978 info->set_mark();
1979 }
1980 }
1981
1982 // traverse backward from target, along edges found in BFS
1983 void PrintBFS::select_all_paths() {
1984 int pos = 0;
1985 GrowableArray<const Node*> backtrace;
1986 // start from target
1987 backtrace.push(_target);
1988 find_info(_target)->set_mark();
1989 // traverse backward
1990 while (pos < backtrace.length()) {
1991 const Node* n = backtrace.at(pos++);
1992 Info* info = find_info(n);
1993 for (int i = 0; i < info->edge_bwd.length(); i++) {
1994 // all backward edges
1995 const Node* back = info->edge_bwd.at(i);
1996 Info* back_info = find_info(back);
1997 if (!back_info->is_marked()) {
1998 // not yet found this on way back.
1999 back_info->set_distance_from_target(info->distance_from_target() + 1);
2000 if (back_info->distance_from_target() + back_info->distance() <= _max_distance) {
2001 // total distance is small enough
2002 back_info->set_mark();
2003 backtrace.push(back);
2004 }
2005 }
2006 }
2007 }
2008 }
2009
2010 void PrintBFS::select_shortest_path() {
2011 const Node* current = _target;
2012 while (true) {
2013 Info* info = find_info(current);
2014 info->set_mark();
2015 if (current == _start) {
2016 break;
2017 }
2018 // first edge -> leads us one step closer to _start
2019 current = info->edge_bwd.at(0);
2020 }
2021 }
2022
2023 // go through worklist in desired order, put the marked ones in print list
2024 void PrintBFS::sort() {
2025 if (_traverse_inputs && !_traverse_outputs) {
2026 // reverse order
2027 for (int i = _worklist.length() - 1; i >= 0; i--) {
2028 const Node* n = _worklist.at(i);
2029 Info* info = find_info(n);
2030 if (info->is_marked()) {
2031 _print_list.push(n);
2032 }
2033 }
2034 } else {
2035 // same order as worklist
2036 for (int i = 0; i < _worklist.length(); i++) {
2037 const Node* n = _worklist.at(i);
2038 Info* info = find_info(n);
2039 if (info->is_marked()) {
2040 _print_list.push(n);
2041 }
2042 }
2043 }
2044 if (_sort_idx) {
2045 _print_list.sort(node_idx_cmp);
2046 }
2047 }
2048
2049 // go through printlist and print
2050 void PrintBFS::print() {
2051 if (_print_list.length() > 0 ) {
2052 print_header();
2053 for (int i = 0; i < _print_list.length(); i++) {
2054 const Node* n = _print_list.at(i);
2055 print_node(n);
2056 }
2057 } else {
2058 _output->print_cr("No nodes to print.");
2059 }
2060 }
2061
2062 void PrintBFS::print_options_help(bool print_examples) {
2063 _output->print_cr("Usage: node->dump_bfs(int max_distance, Node* target, char* options)");
2064 _output->print_cr("");
2065 _output->print_cr("Use cases:");
2066 _output->print_cr(" BFS traversal: no target required");
2067 _output->print_cr(" shortest path: set target");
2068 _output->print_cr(" all paths: set target and put 'A' in options");
2069 _output->print_cr(" detect loop: subcase of all paths, have start==target");
2070 _output->print_cr("");
2071 _output->print_cr("Arguments:");
2072 _output->print_cr(" this/start: staring point of BFS");
2073 _output->print_cr(" target:");
2074 _output->print_cr(" if null: simple BFS");
2075 _output->print_cr(" else: shortest path or all paths between this/start and target");
2076 _output->print_cr(" options:");
2077 _output->print_cr(" if null: same as \"cdmox@B\"");
2078 _output->print_cr(" else: use combination of following characters");
2079 _output->print_cr(" h: display this help info");
2080 _output->print_cr(" H: display this help info, with examples");
2081 _output->print_cr(" +: traverse in-edges (on if neither + nor -)");
2082 _output->print_cr(" -: traverse out-edges");
2083 _output->print_cr(" c: visit control nodes");
2084 _output->print_cr(" d: visit data nodes");
2085 _output->print_cr(" m: visit memory nodes");
2086 _output->print_cr(" o: visit other nodes");
2087 _output->print_cr(" x: visit mixed nodes");
2088 _output->print_cr(" C: boundary control nodes");
2089 _output->print_cr(" D: boundary data nodes");
2090 _output->print_cr(" M: boundary memory nodes");
2091 _output->print_cr(" O: boundary other nodes");
2092 _output->print_cr(" X: boundary mixed nodes");
2093 _output->print_cr(" #: display node category in color (not supported in all terminals)");
2094 _output->print_cr(" S: sort displayed nodes by node idx");
2095 _output->print_cr(" A: all paths (not just shortest path to target)");
2096 _output->print_cr(" @: print old nodes - before matching (if available)");
2097 _output->print_cr(" B: print scheduling blocks (if available)");
2098 _output->print_cr(" $: dump only, no header, no other columns");
2099 _output->print_cr("");
2100 _output->print_cr("recursively follow edges to nodes with permitted visit types,");
2101 _output->print_cr("on the boundary additionally display nodes allowed in boundary types");
2102 _output->print_cr("Note: the categories can be overlapping. For example a mixed node");
2103 _output->print_cr(" can contain control and memory output. Some from the other");
2104 _output->print_cr(" category are also control (Halt, Return, etc).");
2105 _output->print_cr("");
2106 _output->print_cr("output columns:");
2107 _output->print_cr(" dist: BFS distance to this/start");
2108 _output->print_cr(" apd: all paths distance (d_outputart + d_target)");
2109 _output->print_cr(" block: block identifier, based on _pre_order");
2110 _output->print_cr(" head: first node in block");
2111 _output->print_cr(" idom: head node of idom block");
2112 _output->print_cr(" depth: depth of block (_dom_depth)");
2113 _output->print_cr(" old: old IR node - before matching");
2114 _output->print_cr(" dump: node->dump()");
2115 _output->print_cr("");
2116 _output->print_cr("Note: if none of the \"cmdxo\" characters are in the options string");
2117 _output->print_cr(" then we set all of them.");
2118 _output->print_cr(" This allows for short strings like \"#\" for colored input traversal");
2119 _output->print_cr(" or \"-#\" for colored output traversal.");
2120 if (print_examples) {
2121 _output->print_cr("");
2122 _output->print_cr("Examples:");
2123 _output->print_cr(" if->dump_bfs(10, 0, \"+cxo\")");
2124 _output->print_cr(" starting at some if node, traverse inputs recursively");
2125 _output->print_cr(" only along control (mixed and other can also be control)");
2126 _output->print_cr(" phi->dump_bfs(5, 0, \"-dxo\")");
2127 _output->print_cr(" starting at phi node, traverse outputs recursively");
2128 _output->print_cr(" only along data (mixed and other can also have data flow)");
2129 _output->print_cr(" find_node(385)->dump_bfs(3, 0, \"cdmox+#@B\")");
2130 _output->print_cr(" find inputs of node 385, up to 3 nodes up (+)");
2131 _output->print_cr(" traverse all nodes (cdmox), use colors (#)");
2132 _output->print_cr(" display old nodes and blocks, if they exist");
2133 _output->print_cr(" useful call to start with");
2134 _output->print_cr(" find_node(102)->dump_bfs(10, 0, \"dCDMOX-\")");
2135 _output->print_cr(" find non-data dependencies of a data node");
2136 _output->print_cr(" follow data node outputs until we find another category");
2137 _output->print_cr(" node as the boundary");
2138 _output->print_cr(" x->dump_bfs(10, y, 0)");
2139 _output->print_cr(" find shortest path from x to y, along any edge or node");
2140 _output->print_cr(" will not find a path if it is longer than 10");
2141 _output->print_cr(" useful to find how x and y are related");
2142 _output->print_cr(" find_node(741)->dump_bfs(20, find_node(746), \"c+\")");
2143 _output->print_cr(" find shortest control path between two nodes");
2144 _output->print_cr(" find_node(741)->dump_bfs(8, find_node(746), \"cdmox+A\")");
2145 _output->print_cr(" find all paths (A) between two nodes of length at most 8");
2146 _output->print_cr(" find_node(741)->dump_bfs(7, find_node(741), \"c+A\")");
2147 _output->print_cr(" find all control loops for this node");
2148 }
2149 }
2150
2151 bool PrintBFS::parse_options() {
2152 if (_options == nullptr) {
2153 _options = "cdmox@B"; // default options
2154 }
2155 size_t len = strlen(_options);
2156 for (size_t i = 0; i < len; i++) {
2157 switch (_options[i]) {
2158 case '+':
2159 _traverse_inputs = true;
2160 break;
2161 case '-':
2162 _traverse_outputs = true;
2163 break;
2164 case 'c':
2165 _filter_visit._control = true;
2166 break;
2167 case 'm':
2168 _filter_visit._memory = true;
2169 break;
2170 case 'd':
2171 _filter_visit._data = true;
2172 break;
2173 case 'x':
2174 _filter_visit._mixed = true;
2175 break;
2176 case 'o':
2177 _filter_visit._other = true;
2178 break;
2179 case 'C':
2180 _filter_boundary._control = true;
2181 break;
2182 case 'M':
2183 _filter_boundary._memory = true;
2184 break;
2185 case 'D':
2186 _filter_boundary._data = true;
2187 break;
2188 case 'X':
2189 _filter_boundary._mixed = true;
2190 break;
2191 case 'O':
2192 _filter_boundary._other = true;
2193 break;
2194 case 'S':
2195 _sort_idx = true;
2196 break;
2197 case 'A':
2198 _all_paths = true;
2199 break;
2200 case '#':
2201 _use_color = true;
2202 break;
2203 case 'B':
2204 _print_blocks = true;
2205 break;
2206 case '@':
2207 _print_old = true;
2208 break;
2209 case '$':
2210 _dump_only = true;
2211 break;
2212 case 'h':
2213 print_options_help(false);
2214 return false;
2215 case 'H':
2216 print_options_help(true);
2217 return false;
2218 default:
2219 _output->print_cr("dump_bfs: Unrecognized option \'%c\'", _options[i]);
2220 _output->print_cr("for help, run: find_node(0)->dump_bfs(0,0,\"H\")");
2221 return false;
2222 }
2223 }
2224 if (!_traverse_inputs && !_traverse_outputs) {
2225 _traverse_inputs = true;
2226 }
2227 if (_filter_visit.is_empty()) {
2228 _filter_visit.set_all();
2229 }
2230 Compile* C = Compile::current();
2231 _print_old &= (C->matcher() != nullptr); // only show old if there are new
2232 _print_blocks &= (C->cfg() != nullptr); // only show blocks if available
2233 return true;
2234 }
2235
2236 void PrintBFS::DumpConfigColored::pre_dump(outputStream* st, const Node* n) {
2237 if (!_bfs->_use_color) {
2238 return;
2239 }
2240 Info* info = _bfs->find_info(n);
2241 if (info == nullptr || !info->is_marked()) {
2242 return;
2243 }
2244
2245 const Type* t = n->bottom_type();
2246 switch (t->category()) {
2247 case Type::Category::Data:
2248 st->print("\u001b[34m");
2249 break;
2250 case Type::Category::Memory:
2251 st->print("\u001b[32m");
2252 break;
2253 case Type::Category::Mixed:
2254 st->print("\u001b[35m");
2255 break;
2256 case Type::Category::Control:
2257 st->print("\u001b[31m");
2258 break;
2259 case Type::Category::Other:
2260 st->print("\u001b[33m");
2261 break;
2262 case Type::Category::Undef:
2263 n->dump();
2264 assert(false, "category undef ??");
2265 break;
2266 default:
2267 n->dump();
2268 assert(false, "not covered");
2269 break;
2270 }
2271 }
2272
2273 void PrintBFS::DumpConfigColored::post_dump(outputStream* st) {
2274 if (!_bfs->_use_color) {
2275 return;
2276 }
2277 st->print("\u001b[0m"); // white
2278 }
2279
2280 Node* PrintBFS::old_node(const Node* n) {
2281 Compile* C = Compile::current();
2282 if (C->matcher() == nullptr || !C->node_arena()->contains(n)) {
2283 return (Node*)nullptr;
2284 } else {
2285 return C->matcher()->find_old_node(n);
2286 }
2287 }
2288
2289 void PrintBFS::print_node_idx(const Node* n) {
2290 Compile* C = Compile::current();
2291 char buf[30];
2292 if (n == nullptr) {
2293 os::snprintf_checked(buf, sizeof(buf), "_"); // null
2294 } else if (C->node_arena()->contains(n)) {
2295 os::snprintf_checked(buf, sizeof(buf), "%d", n->_idx); // new node
2296 } else {
2297 os::snprintf_checked(buf, sizeof(buf), "o%d", n->_idx); // old node
2298 }
2299 _output->print("%6s", buf);
2300 }
2301
2302 void PrintBFS::print_block_id(const Block* b) {
2303 Compile* C = Compile::current();
2304 char buf[30];
2305 os::snprintf_checked(buf, sizeof(buf), "B%d", b->_pre_order);
2306 _output->print("%7s", buf);
2307 }
2308
2309 void PrintBFS::print_node_block(const Node* n) {
2310 Compile* C = Compile::current();
2311 Block* b = C->node_arena()->contains(n)
2312 ? C->cfg()->get_block_for_node(n)
2313 : nullptr; // guard against old nodes
2314 if (b == nullptr) {
2315 _output->print(" _"); // Block
2316 _output->print(" _"); // head
2317 _output->print(" _"); // idom
2318 _output->print(" _"); // depth
2319 } else {
2320 print_block_id(b);
2321 print_node_idx(b->head());
2322 if (b->_idom) {
2323 print_node_idx(b->_idom->head());
2324 } else {
2325 _output->print(" _"); // idom
2326 }
2327 _output->print("%6d ", b->_dom_depth);
2328 }
2329 }
2330
2331 // filter, and add to worklist, add info, note traversal edges
2332 void PrintBFS::maybe_traverse(const Node* src, const Node* dst) {
2333 if (dst != nullptr &&
2334 (_filter_visit.accepts(dst) ||
2335 _filter_boundary.accepts(dst) ||
2336 dst == _start)) { // correct category or start?
2337 if (find_info(dst) == nullptr) {
2338 // never visited - set up info
2339 _worklist.push(dst);
2340 int d = 0;
2341 if (dst != _start) {
2342 d = find_info(src)->distance() + 1;
2343 }
2344 make_info(dst, d);
2345 }
2346 if (src != dst) {
2347 // traversal edges useful during select
2348 find_info(dst)->edge_bwd.push(src);
2349 }
2350 }
2351 }
2352
2353 void PrintBFS::print_header() const {
2354 if (_dump_only) {
2355 return; // no header in dump only mode
2356 }
2357 _output->print("dist"); // distance
2358 if (_all_paths) {
2359 _output->print(" apd"); // all paths distance
2360 }
2361 if (_print_blocks) {
2362 _output->print(" [block head idom depth]"); // block
2363 }
2364 if (_print_old) {
2365 _output->print(" old"); // old node
2366 }
2367 _output->print(" dump\n"); // node dump
2368 _output->print_cr("---------------------------------------------");
2369 }
2370
2371 void PrintBFS::print_node(const Node* n) {
2372 if (_dump_only) {
2373 n->dump("\n", false, _output, &_dcc);
2374 return;
2375 }
2376 _output->print("%4d", find_info(n)->distance());// distance
2377 if (_all_paths) {
2378 Info* info = find_info(n);
2379 int apd = info->distance() + info->distance_from_target();
2380 _output->print("%4d", apd); // all paths distance
2381 }
2382 if (_print_blocks) {
2383 print_node_block(n); // block
2384 }
2385 if (_print_old) {
2386 print_node_idx(old_node(n)); // old node
2387 }
2388 _output->print(" ");
2389 n->dump("\n", false, _output, &_dcc); // node dump
2390 }
2391
2392 //------------------------------dump_bfs--------------------------------------
2393 // Call this from debugger
2394 // Useful for BFS traversal, shortest path, all path, loop detection, etc
2395 // Designed to be more readable, and provide additional info
2396 // To find all options, run:
2397 // find_node(0)->dump_bfs(0,0,"H")
2398 void Node::dump_bfs(const int max_distance, Node* target, const char* options) const {
2399 dump_bfs(max_distance, target, options, tty);
2400 }
2401
2402 // Used to dump to stream.
2403 void Node::dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st) const {
2404 PrintBFS bfs(this, max_distance, target, options, st);
2405 bfs.run();
2406 }
2407
2408 // Call this from debugger, with default arguments
2409 void Node::dump_bfs(const int max_distance) const {
2410 dump_bfs(max_distance, nullptr, nullptr);
2411 }
2412
2413 // -----------------------------dump_idx---------------------------------------
2414 void Node::dump_idx(bool align, outputStream* st, DumpConfig* dc) const {
2415 if (dc != nullptr) {
2416 dc->pre_dump(st, this);
2417 }
2418 Compile* C = Compile::current();
2419 bool is_new = C->node_arena()->contains(this);
2420 if (align) { // print prefix empty spaces$
2421 // +1 for leading digit, +1 for "o"
2422 uint max_width = static_cast<uint>(log10(static_cast<double>(C->unique()))) + 2;
2423 // +1 for leading digit, maybe +1 for "o"
2424 uint width = static_cast<uint>(log10(static_cast<double>(_idx))) + 1 + (is_new ? 0 : 1);
2425 while (max_width > width) {
2426 st->print(" ");
2427 width++;
2428 }
2429 }
2430 if (!is_new) {
2431 st->print("o");
2432 }
2433 st->print("%d", _idx);
2434 if (dc != nullptr) {
2435 dc->post_dump(st);
2436 }
2437 }
2438
2439 // -----------------------------dump_name--------------------------------------
2440 void Node::dump_name(outputStream* st, DumpConfig* dc) const {
2441 if (dc != nullptr) {
2442 dc->pre_dump(st, this);
2443 }
2444 st->print("%s", Name());
2445 if (dc != nullptr) {
2446 dc->post_dump(st);
2447 }
2448 }
2449
2450 // -----------------------------Name-------------------------------------------
2451 extern const char *NodeClassNames[];
2452 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
2453
2454 static bool is_disconnected(const Node* n) {
2455 for (uint i = 0; i < n->req(); i++) {
2456 if (n->in(i) != nullptr) return false;
2457 }
2458 return true;
2459 }
2460
2461 #ifdef ASSERT
2462 void Node::dump_orig(outputStream *st, bool print_key) const {
2463 Compile* C = Compile::current();
2464 Node* orig = _debug_orig;
2465 if (not_a_node(orig)) orig = nullptr;
2466 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2467 if (orig == nullptr) return;
2468 if (print_key) {
2469 st->print(" !orig=");
2470 }
2471 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
2472 if (not_a_node(fast)) fast = nullptr;
2473 while (orig != nullptr) {
2474 bool discon = is_disconnected(orig); // if discon, print [123] else 123
2475 if (discon) st->print("[");
2476 if (!Compile::current()->node_arena()->contains(orig))
2477 st->print("o");
2478 st->print("%d", orig->_idx);
2479 if (discon) st->print("]");
2480 orig = orig->debug_orig();
2481 if (not_a_node(orig)) orig = nullptr;
2482 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2483 if (orig != nullptr) st->print(",");
2484 if (fast != nullptr) {
2485 // Step fast twice for each single step of orig:
2486 fast = fast->debug_orig();
2487 if (not_a_node(fast)) fast = nullptr;
2488 if (fast != nullptr && fast != orig) {
2489 fast = fast->debug_orig();
2490 if (not_a_node(fast)) fast = nullptr;
2491 }
2492 if (fast == orig) {
2493 st->print("...");
2494 break;
2495 }
2496 }
2497 }
2498 }
2499
2500 void Node::set_debug_orig(Node* orig) {
2501 _debug_orig = orig;
2502 if (BreakAtNode == 0) return;
2503 if (not_a_node(orig)) orig = nullptr;
2504 int trip = 10;
2505 while (orig != nullptr) {
2506 if (orig->debug_idx() == BreakAtNode || (uintx)orig->_idx == BreakAtNode) {
2507 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT " orig._idx=%d orig._debug_idx=" UINT64_FORMAT,
2508 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
2509 BREAKPOINT;
2510 }
2511 orig = orig->debug_orig();
2512 if (not_a_node(orig)) orig = nullptr;
2513 if (trip-- <= 0) break;
2514 }
2515 }
2516 #endif //ASSERT
2517
2518 //------------------------------dump------------------------------------------
2519 // Dump a Node
2520 void Node::dump(const char* suffix, bool mark, outputStream* st, DumpConfig* dc) const {
2521 Compile* C = Compile::current();
2522 bool is_new = C->node_arena()->contains(this);
2523 C->_in_dump_cnt++;
2524
2525 // idx mark name ===
2526 dump_idx(true, st, dc);
2527 st->print(mark ? " >" : " ");
2528 dump_name(st, dc);
2529 st->print(" === ");
2530
2531 // Dump the required and precedence inputs
2532 dump_req(st, dc);
2533 dump_prec(st, dc);
2534 // Dump the outputs
2535 dump_out(st, dc);
2536
2537 if (is_disconnected(this)) {
2538 #ifdef ASSERT
2539 st->print(" [" UINT64_FORMAT "]", debug_idx());
2540 dump_orig(st);
2541 #endif
2542 st->cr();
2543 C->_in_dump_cnt--;
2544 return; // don't process dead nodes
2545 }
2546
2547 if (C->clone_map().value(_idx) != 0) {
2548 C->clone_map().dump(_idx, st);
2549 }
2550 // Dump node-specific info
2551 dump_spec(st);
2552 #ifdef ASSERT
2553 // Dump the non-reset _debug_idx
2554 if (Verbose && WizardMode) {
2555 st->print(" [" UINT64_FORMAT "]", debug_idx());
2556 }
2557 #endif
2558
2559 const Type *t = bottom_type();
2560
2561 if (t != nullptr && (t->isa_instptr() || t->isa_instklassptr())) {
2562 const TypeInstPtr *toop = t->isa_instptr();
2563 const TypeInstKlassPtr *tkls = t->isa_instklassptr();
2564 if (toop) {
2565 st->print(" Oop:");
2566 } else if (tkls) {
2567 st->print(" Klass:");
2568 }
2569 t->dump_on(st);
2570 } else if (t == Type::MEMORY) {
2571 st->print(" Memory:");
2572 MemNode::dump_adr_type(this, adr_type(), st);
2573 } else if (Verbose || WizardMode) {
2574 st->print(" Type:");
2575 if (t) {
2576 t->dump_on(st);
2577 } else {
2578 st->print("no type");
2579 }
2580 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
2581 // Dump MachSpillcopy vector type.
2582 t->dump_on(st);
2583 }
2584 if (is_new) {
2585 DEBUG_ONLY(dump_orig(st));
2586 Node_Notes* nn = C->node_notes_at(_idx);
2587 if (nn != nullptr && !nn->is_clear()) {
2588 if (nn->jvms() != nullptr) {
2589 st->print(" !jvms:");
2590 nn->jvms()->dump_spec(st);
2591 }
2592 }
2593 }
2594 if (suffix) st->print("%s", suffix);
2595 C->_in_dump_cnt--;
2596 }
2597
2598 // call from debugger: dump node to tty with newline
2599 void Node::dump() const {
2600 dump("\n");
2601 }
2602
2603 //------------------------------dump_req--------------------------------------
2604 void Node::dump_req(outputStream* st, DumpConfig* dc) const {
2605 // Dump the required input edges
2606 for (uint i = 0; i < req(); i++) { // For all required inputs
2607 Node* d = in(i);
2608 if (d == nullptr) {
2609 st->print("_ ");
2610 } else if (not_a_node(d)) {
2611 st->print("not_a_node "); // uninitialized, sentinel, garbage, etc.
2612 } else {
2613 d->dump_idx(false, st, dc);
2614 st->print(" ");
2615 }
2616 }
2617 }
2618
2619
2620 //------------------------------dump_prec-------------------------------------
2621 void Node::dump_prec(outputStream* st, DumpConfig* dc) const {
2622 // Dump the precedence edges
2623 int any_prec = 0;
2624 for (uint i = req(); i < len(); i++) { // For all precedence inputs
2625 Node* p = in(i);
2626 if (p != nullptr) {
2627 if (!any_prec++) st->print(" |");
2628 if (not_a_node(p)) { st->print("not_a_node "); continue; }
2629 p->dump_idx(false, st, dc);
2630 st->print(" ");
2631 }
2632 }
2633 }
2634
2635 //------------------------------dump_out--------------------------------------
2636 void Node::dump_out(outputStream* st, DumpConfig* dc) const {
2637 // Delimit the output edges
2638 st->print(" [[ ");
2639 // Dump the output edges
2640 for (uint i = 0; i < _outcnt; i++) { // For all outputs
2641 Node* u = _out[i];
2642 if (u == nullptr) {
2643 st->print("_ ");
2644 } else if (not_a_node(u)) {
2645 st->print("not_a_node ");
2646 } else {
2647 u->dump_idx(false, st, dc);
2648 st->print(" ");
2649 }
2650 }
2651 st->print("]] ");
2652 }
2653
2654 //------------------------------dump-------------------------------------------
2655 // call from debugger: dump Node's inputs (or outputs if d negative)
2656 void Node::dump(int d) const {
2657 dump_bfs(abs(d), nullptr, (d > 0) ? "+$" : "-$");
2658 }
2659
2660 //------------------------------dump_ctrl--------------------------------------
2661 // call from debugger: dump Node's control inputs (or outputs if d negative)
2662 void Node::dump_ctrl(int d) const {
2663 dump_bfs(abs(d), nullptr, (d > 0) ? "+$c" : "-$c");
2664 }
2665
2666 //-----------------------------dump_compact------------------------------------
2667 void Node::dump_comp() const {
2668 this->dump_comp("\n");
2669 }
2670
2671 //-----------------------------dump_compact------------------------------------
2672 // Dump a Node in compact representation, i.e., just print its name and index.
2673 // Nodes can specify additional specifics to print in compact representation by
2674 // implementing dump_compact_spec.
2675 void Node::dump_comp(const char* suffix, outputStream *st) const {
2676 Compile* C = Compile::current();
2677 C->_in_dump_cnt++;
2678 st->print("%s(%d)", Name(), _idx);
2679 this->dump_compact_spec(st);
2680 if (suffix) {
2681 st->print("%s", suffix);
2682 }
2683 C->_in_dump_cnt--;
2684 }
2685
2686 // VERIFICATION CODE
2687 // Verify all nodes if verify_depth is negative
2688 void Node::verify(int verify_depth, VectorSet& visited, Node_List& worklist) {
2689 assert(verify_depth != 0, "depth should not be 0");
2690 Compile* C = Compile::current();
2691 uint last_index_on_current_depth = worklist.size() - 1;
2692 verify_depth--; // Visiting the first node on depth 1
2693 // Only add nodes to worklist if verify_depth is negative (visit all nodes) or greater than 0
2694 bool add_to_worklist = verify_depth != 0;
2695
2696 for (uint list_index = 0; list_index < worklist.size(); list_index++) {
2697 Node* n = worklist[list_index];
2698
2699 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2700 if (C->cached_top_node() == nullptr) {
2701 C->set_cached_top_node((Node*)n);
2702 }
2703 assert(C->cached_top_node() == n, "TOP node must be unique");
2704 }
2705
2706 uint in_len = n->len();
2707 for (uint i = 0; i < in_len; i++) {
2708 Node* x = n->_in[i];
2709 if (!x || x->is_top()) {
2710 continue;
2711 }
2712
2713 // Verify my input has a def-use edge to me
2714 // Count use-def edges from n to x
2715 int cnt = 1;
2716 for (uint j = 0; j < i; j++) {
2717 if (n->_in[j] == x) {
2718 cnt++;
2719 break;
2720 }
2721 }
2722 if (cnt == 2) {
2723 // x is already checked as n's previous input, skip its duplicated def-use count checking
2724 continue;
2725 }
2726 for (uint j = i + 1; j < in_len; j++) {
2727 if (n->_in[j] == x) {
2728 cnt++;
2729 }
2730 }
2731
2732 // Count def-use edges from x to n
2733 uint max = x->_outcnt;
2734 for (uint k = 0; k < max; k++) {
2735 if (x->_out[k] == n) {
2736 cnt--;
2737 }
2738 }
2739 assert(cnt == 0, "mismatched def-use edge counts");
2740
2741 if (add_to_worklist && !visited.test_set(x->_idx)) {
2742 worklist.push(x);
2743 }
2744 }
2745
2746 if (verify_depth > 0 && list_index == last_index_on_current_depth) {
2747 // All nodes on this depth were processed and its inputs are on the worklist. Decrement verify_depth and
2748 // store the current last list index which is the last node in the list with the new depth. All nodes
2749 // added afterwards will have a new depth again. Stop adding new nodes if depth limit is reached (=0).
2750 verify_depth--;
2751 if (verify_depth == 0) {
2752 add_to_worklist = false;
2753 }
2754 last_index_on_current_depth = worklist.size() - 1;
2755 }
2756 }
2757 }
2758 #endif // not PRODUCT
2759
2760 //------------------------------Registers--------------------------------------
2761 // Do we Match on this edge index or not? Generally false for Control
2762 // and true for everything else. Weird for calls & returns.
2763 uint Node::match_edge(uint idx) const {
2764 return idx; // True for other than index 0 (control)
2765 }
2766
2767 // Register classes are defined for specific machines
2768 const RegMask &Node::out_RegMask() const {
2769 ShouldNotCallThis();
2770 return RegMask::Empty;
2771 }
2772
2773 const RegMask &Node::in_RegMask(uint) const {
2774 ShouldNotCallThis();
2775 return RegMask::Empty;
2776 }
2777
2778 void Node_Array::grow(uint i) {
2779 _nesting.check(_a); // Check if a potential reallocation in the arena is safe
2780 if (i < _max) {
2781 return; // No need to grow
2782 }
2783 assert(_max > 0, "invariant");
2784 uint old = _max;
2785 _max = next_power_of_2(i);
2786 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2787 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2788 }
2789
2790 void Node_Array::insert(uint i, Node* n) {
2791 if (_nodes[_max - 1]) {
2792 grow(_max);
2793 }
2794 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i + 1], ((_max - i - 1) * sizeof(Node*)));
2795 _nodes[i] = n;
2796 }
2797
2798 void Node_Array::remove(uint i) {
2799 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i + 1], (HeapWord*)&_nodes[i], ((_max - i - 1) * sizeof(Node*)));
2800 _nodes[_max - 1] = nullptr;
2801 }
2802
2803 void Node_Array::dump() const {
2804 #ifndef PRODUCT
2805 for (uint i = 0; i < _max; i++) {
2806 Node* nn = _nodes[i];
2807 if (nn != nullptr) {
2808 tty->print("%5d--> ",i); nn->dump();
2809 }
2810 }
2811 #endif
2812 }
2813
2814 //--------------------------is_iteratively_computed------------------------------
2815 // Operation appears to be iteratively computed (such as an induction variable)
2816 // It is possible for this operation to return false for a loop-varying
2817 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2818 bool Node::is_iteratively_computed() {
2819 if (ideal_reg()) { // does operation have a result register?
2820 for (uint i = 1; i < req(); i++) {
2821 Node* n = in(i);
2822 if (n != nullptr && n->is_Phi()) {
2823 for (uint j = 1; j < n->req(); j++) {
2824 if (n->in(j) == this) {
2825 return true;
2826 }
2827 }
2828 }
2829 }
2830 }
2831 return false;
2832 }
2833
2834 //--------------------------find_similar------------------------------
2835 // Return a node with opcode "opc" and same inputs as "this" if one can
2836 // be found; Otherwise return null;
2837 Node* Node::find_similar(int opc) {
2838 if (req() >= 2) {
2839 Node* def = in(1);
2840 if (def && def->outcnt() >= 2) {
2841 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2842 Node* use = def->fast_out(i);
2843 if (use != this &&
2844 use->Opcode() == opc &&
2845 use->req() == req()) {
2846 uint j;
2847 for (j = 0; j < use->req(); j++) {
2848 if (use->in(j) != in(j)) {
2849 break;
2850 }
2851 }
2852 if (j == use->req()) {
2853 return use;
2854 }
2855 }
2856 }
2857 }
2858 }
2859 return nullptr;
2860 }
2861
2862
2863 //--------------------------unique_ctrl_out_or_null-------------------------
2864 // Return the unique control out if only one. Null if none or more than one.
2865 Node* Node::unique_ctrl_out_or_null() const {
2866 Node* found = nullptr;
2867 for (uint i = 0; i < outcnt(); i++) {
2868 Node* use = raw_out(i);
2869 if (use->is_CFG() && use != this) {
2870 if (found != nullptr) {
2871 return nullptr;
2872 }
2873 found = use;
2874 }
2875 }
2876 return found;
2877 }
2878
2879 //--------------------------unique_ctrl_out------------------------------
2880 // Return the unique control out. Asserts if none or more than one control out.
2881 Node* Node::unique_ctrl_out() const {
2882 Node* ctrl = unique_ctrl_out_or_null();
2883 assert(ctrl != nullptr, "control out is assumed to be unique");
2884 return ctrl;
2885 }
2886
2887 void Node::ensure_control_or_add_prec(Node* c) {
2888 if (in(0) == nullptr) {
2889 set_req(0, c);
2890 } else if (in(0) != c) {
2891 add_prec(c);
2892 }
2893 }
2894
2895 bool Node::is_dead_loop_safe() const {
2896 if (is_Phi()) {
2897 return true;
2898 }
2899 if (is_Proj() && in(0) == nullptr) {
2900 return true;
2901 }
2902 if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
2903 if (!is_Proj()) {
2904 return true;
2905 }
2906 if (in(0)->is_Allocate()) {
2907 return false;
2908 }
2909 // MemNode::can_see_stored_value() peeks through the boxing call
2910 if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
2911 return false;
2912 }
2913 return true;
2914 }
2915 return false;
2916 }
2917
2918 //=============================================================================
2919 //------------------------------yank-------------------------------------------
2920 // Find and remove
2921 void Node_List::yank( Node *n ) {
2922 uint i;
2923 for (i = 0; i < _cnt; i++) {
2924 if (_nodes[i] == n) {
2925 break;
2926 }
2927 }
2928
2929 if (i < _cnt) {
2930 _nodes[i] = _nodes[--_cnt];
2931 }
2932 }
2933
2934 //------------------------------dump-------------------------------------------
2935 void Node_List::dump() const {
2936 #ifndef PRODUCT
2937 for (uint i = 0; i < _cnt; i++) {
2938 if (_nodes[i]) {
2939 tty->print("%5d--> ", i);
2940 _nodes[i]->dump();
2941 }
2942 }
2943 #endif
2944 }
2945
2946 void Node_List::dump_simple() const {
2947 #ifndef PRODUCT
2948 for (uint i = 0; i < _cnt; i++) {
2949 if( _nodes[i] ) {
2950 tty->print(" %d", _nodes[i]->_idx);
2951 } else {
2952 tty->print(" null");
2953 }
2954 }
2955 #endif
2956 }
2957
2958 //=============================================================================
2959 //------------------------------remove-----------------------------------------
2960 void Unique_Node_List::remove(Node* n) {
2961 if (_in_worklist.test(n->_idx)) {
2962 for (uint i = 0; i < size(); i++) {
2963 if (_nodes[i] == n) {
2964 map(i, Node_List::pop());
2965 _in_worklist.remove(n->_idx);
2966 return;
2967 }
2968 }
2969 ShouldNotReachHere();
2970 }
2971 }
2972
2973 //-----------------------remove_useless_nodes----------------------------------
2974 // Remove useless nodes from worklist
2975 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2976 for (uint i = 0; i < size(); ++i) {
2977 Node *n = at(i);
2978 assert( n != nullptr, "Did not expect null entries in worklist");
2979 if (!useful.test(n->_idx)) {
2980 _in_worklist.remove(n->_idx);
2981 map(i, Node_List::pop());
2982 --i; // Visit popped node
2983 // If it was last entry, loop terminates since size() was also reduced
2984 }
2985 }
2986 }
2987
2988 //=============================================================================
2989 void Node_Stack::grow() {
2990 _nesting.check(_a); // Check if a potential reallocation in the arena is safe
2991 if (_inode_top < _inode_max) {
2992 return; // No need to grow
2993 }
2994 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2995 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2996 size_t max = old_max << 1; // max * 2
2997 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2998 _inode_max = _inodes + max;
2999 _inode_top = _inodes + old_top; // restore _top
3000 }
3001
3002 // Node_Stack is used to map nodes.
3003 Node* Node_Stack::find(uint idx) const {
3004 uint sz = size();
3005 for (uint i = 0; i < sz; i++) {
3006 if (idx == index_at(i)) {
3007 return node_at(i);
3008 }
3009 }
3010 return nullptr;
3011 }
3012
3013 //=============================================================================
3014 uint TypeNode::size_of() const { return sizeof(*this); }
3015 #ifndef PRODUCT
3016 void TypeNode::dump_spec(outputStream *st) const {
3017 if (!Verbose && !WizardMode) {
3018 // standard dump does this in Verbose and WizardMode
3019 st->print(" #"); _type->dump_on(st);
3020 }
3021 }
3022
3023 void TypeNode::dump_compact_spec(outputStream *st) const {
3024 st->print("#");
3025 _type->dump_on(st);
3026 }
3027 #endif
3028 uint TypeNode::hash() const {
3029 return Node::hash() + _type->hash();
3030 }
3031 bool TypeNode::cmp(const Node& n) const {
3032 return Type::equals(_type, n.as_Type()->_type);
3033 }
3034 const Type* TypeNode::bottom_type() const { return _type; }
3035 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
3036
3037 //------------------------------ideal_reg--------------------------------------
3038 uint TypeNode::ideal_reg() const {
3039 return _type->ideal_reg();
3040 }