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