1 /*
2 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/ad.hpp"
32 #include "opto/castnode.hpp"
33 #include "opto/cfgnode.hpp"
34 #include "opto/connode.hpp"
35 #include "opto/loopnode.hpp"
36 #include "opto/machnode.hpp"
37 #include "opto/matcher.hpp"
38 #include "opto/node.hpp"
39 #include "opto/opcodes.hpp"
40 #include "opto/regmask.hpp"
41 #include "opto/rootnode.hpp"
42 #include "opto/type.hpp"
43 #include "utilities/copy.hpp"
44 #include "utilities/macros.hpp"
45 #include "utilities/powerOfTwo.hpp"
46
47 class RegMask;
48 // #include "phase.hpp"
49 class PhaseTransform;
50 class PhaseGVN;
51
52 // Arena we are currently building Nodes in
53 const uint Node::NotAMachineReg = 0xffff0000;
54
55 #ifndef PRODUCT
56 extern int nodes_created;
57 #endif
58 #ifdef __clang__
59 #pragma clang diagnostic push
60 #pragma GCC diagnostic ignored "-Wuninitialized"
61 #endif
62
63 #ifdef ASSERT
64
65 //-------------------------- construct_node------------------------------------
66 // Set a breakpoint here to identify where a particular node index is built.
verify_construction()67 void Node::verify_construction() {
68 _debug_orig = NULL;
69 int old_debug_idx = Compile::debug_idx();
70 int new_debug_idx = old_debug_idx + 1;
71 if (new_debug_idx > 0) {
72 // Arrange that the lowest five decimal digits of _debug_idx
73 // will repeat those of _idx. In case this is somehow pathological,
74 // we continue to assign negative numbers (!) consecutively.
75 const int mod = 100000;
76 int bump = (int)(_idx - new_debug_idx) % mod;
77 if (bump < 0) {
78 bump += mod;
79 }
80 assert(bump >= 0 && bump < mod, "");
81 new_debug_idx += bump;
82 }
83 Compile::set_debug_idx(new_debug_idx);
84 set_debug_idx(new_debug_idx);
85 Compile* C = Compile::current();
86 assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
87 if (!C->phase_optimize_finished()) {
88 // Only check assert during parsing and optimization phase. Skip it while generating code.
89 assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
90 }
91 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
92 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
93 BREAKPOINT;
94 }
95 #if OPTO_DU_ITERATOR_ASSERT
96 _last_del = NULL;
97 _del_tick = 0;
98 #endif
99 _hash_lock = 0;
100 }
101
102
103 // #ifdef ASSERT ...
104
105 #if OPTO_DU_ITERATOR_ASSERT
sample(const Node * node)106 void DUIterator_Common::sample(const Node* node) {
107 _vdui = VerifyDUIterators;
108 _node = node;
109 _outcnt = node->_outcnt;
110 _del_tick = node->_del_tick;
111 _last = NULL;
112 }
113
verify(const Node * node,bool at_end_ok)114 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
115 assert(_node == node, "consistent iterator source");
116 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
117 }
118
verify_resync()119 void DUIterator_Common::verify_resync() {
120 // Ensure that the loop body has just deleted the last guy produced.
121 const Node* node = _node;
122 // Ensure that at least one copy of the last-seen edge was deleted.
123 // Note: It is OK to delete multiple copies of the last-seen edge.
124 // Unfortunately, we have no way to verify that all the deletions delete
125 // that same edge. On this point we must use the Honor System.
126 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
127 assert(node->_last_del == _last, "must have deleted the edge just produced");
128 // We liked this deletion, so accept the resulting outcnt and tick.
129 _outcnt = node->_outcnt;
130 _del_tick = node->_del_tick;
131 }
132
reset(const DUIterator_Common & that)133 void DUIterator_Common::reset(const DUIterator_Common& that) {
134 if (this == &that) return; // ignore assignment to self
135 if (!_vdui) {
136 // We need to initialize everything, overwriting garbage values.
137 _last = that._last;
138 _vdui = that._vdui;
139 }
140 // Note: It is legal (though odd) for an iterator over some node x
141 // to be reassigned to iterate over another node y. Some doubly-nested
142 // progress loops depend on being able to do this.
143 const Node* node = that._node;
144 // Re-initialize everything, except _last.
145 _node = node;
146 _outcnt = node->_outcnt;
147 _del_tick = node->_del_tick;
148 }
149
sample(const Node * node)150 void DUIterator::sample(const Node* node) {
151 DUIterator_Common::sample(node); // Initialize the assertion data.
152 _refresh_tick = 0; // No refreshes have happened, as yet.
153 }
154
verify(const Node * node,bool at_end_ok)155 void DUIterator::verify(const Node* node, bool at_end_ok) {
156 DUIterator_Common::verify(node, at_end_ok);
157 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
158 }
159
verify_increment()160 void DUIterator::verify_increment() {
161 if (_refresh_tick & 1) {
162 // We have refreshed the index during this loop.
163 // Fix up _idx to meet asserts.
164 if (_idx > _outcnt) _idx = _outcnt;
165 }
166 verify(_node, true);
167 }
168
verify_resync()169 void DUIterator::verify_resync() {
170 // Note: We do not assert on _outcnt, because insertions are OK here.
171 DUIterator_Common::verify_resync();
172 // Make sure we are still in sync, possibly with no more out-edges:
173 verify(_node, true);
174 }
175
reset(const DUIterator & that)176 void DUIterator::reset(const DUIterator& that) {
177 if (this == &that) return; // self assignment is always a no-op
178 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
179 assert(that._idx == 0, "assign only the result of Node::outs()");
180 assert(_idx == that._idx, "already assigned _idx");
181 if (!_vdui) {
182 // We need to initialize everything, overwriting garbage values.
183 sample(that._node);
184 } else {
185 DUIterator_Common::reset(that);
186 if (_refresh_tick & 1) {
187 _refresh_tick++; // Clear the "was refreshed" flag.
188 }
189 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
190 }
191 }
192
refresh()193 void DUIterator::refresh() {
194 DUIterator_Common::sample(_node); // Re-fetch assertion data.
195 _refresh_tick |= 1; // Set the "was refreshed" flag.
196 }
197
verify_finish()198 void DUIterator::verify_finish() {
199 // If the loop has killed the node, do not require it to re-run.
200 if (_node->_outcnt == 0) _refresh_tick &= ~1;
201 // If this assert triggers, it means that a loop used refresh_out_pos
202 // to re-synch an iteration index, but the loop did not correctly
203 // re-run itself, using a "while (progress)" construct.
204 // This iterator enforces the rule that you must keep trying the loop
205 // until it "runs clean" without any need for refreshing.
206 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
207 }
208
209
verify(const Node * node,bool at_end_ok)210 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
211 DUIterator_Common::verify(node, at_end_ok);
212 Node** out = node->_out;
213 uint cnt = node->_outcnt;
214 assert(cnt == _outcnt, "no insertions allowed");
215 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
216 // This last check is carefully designed to work for NO_OUT_ARRAY.
217 }
218
verify_limit()219 void DUIterator_Fast::verify_limit() {
220 const Node* node = _node;
221 verify(node, true);
222 assert(_outp == node->_out + node->_outcnt, "limit still correct");
223 }
224
verify_resync()225 void DUIterator_Fast::verify_resync() {
226 const Node* node = _node;
227 if (_outp == node->_out + _outcnt) {
228 // Note that the limit imax, not the pointer i, gets updated with the
229 // exact count of deletions. (For the pointer it's always "--i".)
230 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
231 // This is a limit pointer, with a name like "imax".
232 // Fudge the _last field so that the common assert will be happy.
233 _last = (Node*) node->_last_del;
234 DUIterator_Common::verify_resync();
235 } else {
236 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
237 // A normal internal pointer.
238 DUIterator_Common::verify_resync();
239 // Make sure we are still in sync, possibly with no more out-edges:
240 verify(node, true);
241 }
242 }
243
verify_relimit(uint n)244 void DUIterator_Fast::verify_relimit(uint n) {
245 const Node* node = _node;
246 assert((int)n > 0, "use imax -= n only with a positive count");
247 // This must be a limit pointer, with a name like "imax".
248 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
249 // The reported number of deletions must match what the node saw.
250 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
251 // Fudge the _last field so that the common assert will be happy.
252 _last = (Node*) node->_last_del;
253 DUIterator_Common::verify_resync();
254 }
255
reset(const DUIterator_Fast & that)256 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
257 assert(_outp == that._outp, "already assigned _outp");
258 DUIterator_Common::reset(that);
259 }
260
verify(const Node * node,bool at_end_ok)261 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
262 // at_end_ok means the _outp is allowed to underflow by 1
263 _outp += at_end_ok;
264 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
265 _outp -= at_end_ok;
266 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
267 }
268
verify_limit()269 void DUIterator_Last::verify_limit() {
270 // Do not require the limit address to be resynched.
271 //verify(node, true);
272 assert(_outp == _node->_out, "limit still correct");
273 }
274
verify_step(uint num_edges)275 void DUIterator_Last::verify_step(uint num_edges) {
276 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
277 _outcnt -= num_edges;
278 _del_tick += num_edges;
279 // Make sure we are still in sync, possibly with no more out-edges:
280 const Node* node = _node;
281 verify(node, true);
282 assert(node->_last_del == _last, "must have deleted the edge just produced");
283 }
284
285 #endif //OPTO_DU_ITERATOR_ASSERT
286
287
288 #endif //ASSERT
289
290
291 // This constant used to initialize _out may be any non-null value.
292 // The value NULL is reserved for the top node only.
293 #define NO_OUT_ARRAY ((Node**)-1)
294
295 // Out-of-line code from node constructors.
296 // Executed only when extra debug info. is being passed around.
init_node_notes(Compile * C,int idx,Node_Notes * nn)297 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
298 C->set_node_notes_at(idx, nn);
299 }
300
301 // Shared initialization code.
Init(int req)302 inline int Node::Init(int req) {
303 Compile* C = Compile::current();
304 int idx = C->next_unique();
305
306 // Allocate memory for the necessary number of edges.
307 if (req > 0) {
308 // Allocate space for _in array to have double alignment.
309 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
310 }
311 // If there are default notes floating around, capture them:
312 Node_Notes* nn = C->default_node_notes();
313 if (nn != NULL) init_node_notes(C, idx, nn);
314
315 // Note: At this point, C is dead,
316 // and we begin to initialize the new Node.
317
318 _cnt = _max = req;
319 _outcnt = _outmax = 0;
320 _class_id = Class_Node;
321 _flags = 0;
322 _out = NO_OUT_ARRAY;
323 return idx;
324 }
325
326 //------------------------------Node-------------------------------------------
327 // Create a Node, with a given number of required edges.
Node(uint req)328 Node::Node(uint req)
329 : _idx(Init(req))
330 #ifdef ASSERT
331 , _parse_idx(_idx)
332 #endif
333 {
334 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
335 debug_only( verify_construction() );
336 NOT_PRODUCT(nodes_created++);
337 if (req == 0) {
338 _in = NULL;
339 } else {
340 Node** to = _in;
341 for(uint i = 0; i < req; i++) {
342 to[i] = NULL;
343 }
344 }
345 }
346
347 //------------------------------Node-------------------------------------------
Node(Node * n0)348 Node::Node(Node *n0)
349 : _idx(Init(1))
350 #ifdef ASSERT
351 , _parse_idx(_idx)
352 #endif
353 {
354 debug_only( verify_construction() );
355 NOT_PRODUCT(nodes_created++);
356 assert( is_not_dead(n0), "can not use dead node");
357 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
358 }
359
360 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1)361 Node::Node(Node *n0, Node *n1)
362 : _idx(Init(2))
363 #ifdef ASSERT
364 , _parse_idx(_idx)
365 #endif
366 {
367 debug_only( verify_construction() );
368 NOT_PRODUCT(nodes_created++);
369 assert( is_not_dead(n0), "can not use dead node");
370 assert( is_not_dead(n1), "can not use dead node");
371 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
372 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
373 }
374
375 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2)376 Node::Node(Node *n0, Node *n1, Node *n2)
377 : _idx(Init(3))
378 #ifdef ASSERT
379 , _parse_idx(_idx)
380 #endif
381 {
382 debug_only( verify_construction() );
383 NOT_PRODUCT(nodes_created++);
384 assert( is_not_dead(n0), "can not use dead node");
385 assert( is_not_dead(n1), "can not use dead node");
386 assert( is_not_dead(n2), "can not use dead node");
387 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
388 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
389 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
390 }
391
392 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3)393 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
394 : _idx(Init(4))
395 #ifdef ASSERT
396 , _parse_idx(_idx)
397 #endif
398 {
399 debug_only( verify_construction() );
400 NOT_PRODUCT(nodes_created++);
401 assert( is_not_dead(n0), "can not use dead node");
402 assert( is_not_dead(n1), "can not use dead node");
403 assert( is_not_dead(n2), "can not use dead node");
404 assert( is_not_dead(n3), "can not use dead node");
405 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
406 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
407 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
408 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
409 }
410
411 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3,Node * n4)412 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
413 : _idx(Init(5))
414 #ifdef ASSERT
415 , _parse_idx(_idx)
416 #endif
417 {
418 debug_only( verify_construction() );
419 NOT_PRODUCT(nodes_created++);
420 assert( is_not_dead(n0), "can not use dead node");
421 assert( is_not_dead(n1), "can not use dead node");
422 assert( is_not_dead(n2), "can not use dead node");
423 assert( is_not_dead(n3), "can not use dead node");
424 assert( is_not_dead(n4), "can not use dead node");
425 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
426 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
427 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
428 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
429 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
430 }
431
432 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3,Node * n4,Node * n5)433 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
434 Node *n4, Node *n5)
435 : _idx(Init(6))
436 #ifdef ASSERT
437 , _parse_idx(_idx)
438 #endif
439 {
440 debug_only( verify_construction() );
441 NOT_PRODUCT(nodes_created++);
442 assert( is_not_dead(n0), "can not use dead node");
443 assert( is_not_dead(n1), "can not use dead node");
444 assert( is_not_dead(n2), "can not use dead node");
445 assert( is_not_dead(n3), "can not use dead node");
446 assert( is_not_dead(n4), "can not use dead node");
447 assert( is_not_dead(n5), "can not use dead node");
448 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
449 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
450 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
451 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
452 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
453 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
454 }
455
456 //------------------------------Node-------------------------------------------
Node(Node * n0,Node * n1,Node * n2,Node * n3,Node * n4,Node * n5,Node * n6)457 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
458 Node *n4, Node *n5, Node *n6)
459 : _idx(Init(7))
460 #ifdef ASSERT
461 , _parse_idx(_idx)
462 #endif
463 {
464 debug_only( verify_construction() );
465 NOT_PRODUCT(nodes_created++);
466 assert( is_not_dead(n0), "can not use dead node");
467 assert( is_not_dead(n1), "can not use dead node");
468 assert( is_not_dead(n2), "can not use dead node");
469 assert( is_not_dead(n3), "can not use dead node");
470 assert( is_not_dead(n4), "can not use dead node");
471 assert( is_not_dead(n5), "can not use dead node");
472 assert( is_not_dead(n6), "can not use dead node");
473 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
474 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
475 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
476 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
477 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
478 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
479 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
480 }
481
482 #ifdef __clang__
483 #pragma clang diagnostic pop
484 #endif
485
486
487 //------------------------------clone------------------------------------------
488 // Clone a Node.
clone() const489 Node *Node::clone() const {
490 Compile* C = Compile::current();
491 uint s = size_of(); // Size of inherited Node
492 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
493 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
494 // Set the new input pointer array
495 n->_in = (Node**)(((char*)n)+s);
496 // Cannot share the old output pointer array, so kill it
497 n->_out = NO_OUT_ARRAY;
498 // And reset the counters to 0
499 n->_outcnt = 0;
500 n->_outmax = 0;
501 // Unlock this guy, since he is not in any hash table.
502 debug_only(n->_hash_lock = 0);
503 // Walk the old node's input list to duplicate its edges
504 uint i;
505 for( i = 0; i < len(); i++ ) {
506 Node *x = in(i);
507 n->_in[i] = x;
508 if (x != NULL) x->add_out(n);
509 }
510 if (is_macro())
511 C->add_macro_node(n);
512 if (is_expensive())
513 C->add_expensive_node(n);
514 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
515 bs->register_potential_barrier_node(n);
516 // If the cloned node is a range check dependent CastII, add it to the list.
517 CastIINode* cast = n->isa_CastII();
518 if (cast != NULL && cast->has_range_check()) {
519 C->add_range_check_cast(cast);
520 }
521 if (n->Opcode() == Op_Opaque4) {
522 C->add_opaque4_node(n);
523 }
524
525 n->set_idx(C->next_unique()); // Get new unique index as well
526 debug_only( n->verify_construction() );
527 NOT_PRODUCT(nodes_created++);
528 // Do not patch over the debug_idx of a clone, because it makes it
529 // impossible to break on the clone's moment of creation.
530 //debug_only( n->set_debug_idx( debug_idx() ) );
531
532 C->copy_node_notes_to(n, (Node*) this);
533
534 // MachNode clone
535 uint nopnds;
536 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
537 MachNode *mach = n->as_Mach();
538 MachNode *mthis = this->as_Mach();
539 // Get address of _opnd_array.
540 // It should be the same offset since it is the clone of this node.
541 MachOper **from = mthis->_opnds;
542 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
543 pointer_delta((const void*)from,
544 (const void*)(&mthis->_opnds), 1));
545 mach->_opnds = to;
546 for ( uint i = 0; i < nopnds; ++i ) {
547 to[i] = from[i]->clone();
548 }
549 }
550 // cloning CallNode may need to clone JVMState
551 if (n->is_Call()) {
552 n->as_Call()->clone_jvms(C);
553 }
554 if (n->is_SafePoint()) {
555 n->as_SafePoint()->clone_replaced_nodes();
556 }
557 return n; // Return the clone
558 }
559
560 //---------------------------setup_is_top--------------------------------------
561 // Call this when changing the top node, to reassert the invariants
562 // required by Node::is_top. See Compile::set_cached_top_node.
setup_is_top()563 void Node::setup_is_top() {
564 if (this == (Node*)Compile::current()->top()) {
565 // This node has just become top. Kill its out array.
566 _outcnt = _outmax = 0;
567 _out = NULL; // marker value for top
568 assert(is_top(), "must be top");
569 } else {
570 if (_out == NULL) _out = NO_OUT_ARRAY;
571 assert(!is_top(), "must not be top");
572 }
573 }
574
575 //------------------------------~Node------------------------------------------
576 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
destruct()577 void Node::destruct() {
578 // Eagerly reclaim unique Node numberings
579 Compile* compile = Compile::current();
580 if ((uint)_idx+1 == compile->unique()) {
581 compile->set_unique(compile->unique()-1);
582 }
583 // Clear debug info:
584 Node_Notes* nn = compile->node_notes_at(_idx);
585 if (nn != NULL) nn->clear();
586 // Walk the input array, freeing the corresponding output edges
587 _cnt = _max; // forget req/prec distinction
588 uint i;
589 for( i = 0; i < _max; i++ ) {
590 set_req(i, NULL);
591 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
592 }
593 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
594 // See if the input array was allocated just prior to the object
595 int edge_size = _max*sizeof(void*);
596 int out_edge_size = _outmax*sizeof(void*);
597 char *edge_end = ((char*)_in) + edge_size;
598 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
599 int node_size = size_of();
600
601 // Free the output edge array
602 if (out_edge_size > 0) {
603 compile->node_arena()->Afree(out_array, out_edge_size);
604 }
605
606 // Free the input edge array and the node itself
607 if( edge_end == (char*)this ) {
608 // It was; free the input array and object all in one hit
609 #ifndef ASSERT
610 compile->node_arena()->Afree(_in,edge_size+node_size);
611 #endif
612 } else {
613 // Free just the input array
614 compile->node_arena()->Afree(_in,edge_size);
615
616 // Free just the object
617 #ifndef ASSERT
618 compile->node_arena()->Afree(this,node_size);
619 #endif
620 }
621 if (is_macro()) {
622 compile->remove_macro_node(this);
623 }
624 if (is_expensive()) {
625 compile->remove_expensive_node(this);
626 }
627 CastIINode* cast = isa_CastII();
628 if (cast != NULL && cast->has_range_check()) {
629 compile->remove_range_check_cast(cast);
630 }
631 if (Opcode() == Op_Opaque4) {
632 compile->remove_opaque4_node(this);
633 }
634
635 if (is_SafePoint()) {
636 as_SafePoint()->delete_replaced_nodes();
637 }
638 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
639 bs->unregister_potential_barrier_node(this);
640 #ifdef ASSERT
641 // We will not actually delete the storage, but we'll make the node unusable.
642 *(address*)this = badAddress; // smash the C++ vtbl, probably
643 _in = _out = (Node**) badAddress;
644 _max = _cnt = _outmax = _outcnt = 0;
645 compile->remove_modified_node(this);
646 #endif
647 }
648
649 //------------------------------grow-------------------------------------------
650 // Grow the input array, making space for more edges
grow(uint len)651 void Node::grow( uint len ) {
652 Arena* arena = Compile::current()->node_arena();
653 uint new_max = _max;
654 if( new_max == 0 ) {
655 _max = 4;
656 _in = (Node**)arena->Amalloc(4*sizeof(Node*));
657 Node** to = _in;
658 to[0] = NULL;
659 to[1] = NULL;
660 to[2] = NULL;
661 to[3] = NULL;
662 return;
663 }
664 new_max = next_power_of_2(len);
665 // Trimming to limit allows a uint8 to handle up to 255 edges.
666 // Previously I was using only powers-of-2 which peaked at 128 edges.
667 //if( new_max >= limit ) new_max = limit-1;
668 _in = (Node**)arena->Arealloc(_in, _max*sizeof(Node*), new_max*sizeof(Node*));
669 Copy::zero_to_bytes(&_in[_max], (new_max-_max)*sizeof(Node*)); // NULL all new space
670 _max = new_max; // Record new max length
671 // This assertion makes sure that Node::_max is wide enough to
672 // represent the numerical value of new_max.
673 assert(_max == new_max && _max > len, "int width of _max is too small");
674 }
675
676 //-----------------------------out_grow----------------------------------------
677 // Grow the input array, making space for more edges
out_grow(uint len)678 void Node::out_grow( uint len ) {
679 assert(!is_top(), "cannot grow a top node's out array");
680 Arena* arena = Compile::current()->node_arena();
681 uint new_max = _outmax;
682 if( new_max == 0 ) {
683 _outmax = 4;
684 _out = (Node **)arena->Amalloc(4*sizeof(Node*));
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 assert(_out != NULL && _out != NO_OUT_ARRAY, "out must have sensible value");
692 _out = (Node**)arena->Arealloc(_out,_outmax*sizeof(Node*),new_max*sizeof(Node*));
693 //Copy::zero_to_bytes(&_out[_outmax], (new_max-_outmax)*sizeof(Node*)); // NULL all new space
694 _outmax = new_max; // Record new max length
695 // This assertion makes sure that Node::_max is wide enough to
696 // represent the numerical value of new_max.
697 assert(_outmax == new_max && _outmax > len, "int width of _outmax is too small");
698 }
699
700 #ifdef ASSERT
701 //------------------------------is_dead----------------------------------------
is_dead() const702 bool Node::is_dead() const {
703 // Mach and pinch point nodes may look like dead.
704 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
705 return false;
706 for( uint i = 0; i < _max; i++ )
707 if( _in[i] != NULL )
708 return false;
709 dump();
710 return true;
711 }
712
is_reachable_from_root() const713 bool Node::is_reachable_from_root() const {
714 ResourceMark rm;
715 Unique_Node_List wq;
716 wq.push((Node*)this);
717 RootNode* root = Compile::current()->root();
718 for (uint i = 0; i < wq.size(); i++) {
719 Node* m = wq.at(i);
720 if (m == root) {
721 return true;
722 }
723 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
724 Node* u = m->fast_out(j);
725 wq.push(u);
726 }
727 }
728 return false;
729 }
730 #endif
731
732 //------------------------------is_unreachable---------------------------------
is_unreachable(PhaseIterGVN & igvn) const733 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
734 assert(!is_Mach(), "doesn't work with MachNodes");
735 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != NULL && in(0)->is_top());
736 }
737
738 //------------------------------add_req----------------------------------------
739 // Add a new required input at the end
add_req(Node * n)740 void Node::add_req( Node *n ) {
741 assert( is_not_dead(n), "can not use dead node");
742
743 // Look to see if I can move precedence down one without reallocating
744 if( (_cnt >= _max) || (in(_max-1) != NULL) )
745 grow( _max+1 );
746
747 // Find a precedence edge to move
748 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
749 uint i;
750 for( i=_cnt; i<_max; i++ )
751 if( in(i) == NULL ) // Find the NULL at end of prec edge list
752 break; // There must be one, since we grew the array
753 _in[i] = in(_cnt); // Move prec over, making space for req edge
754 }
755 _in[_cnt++] = n; // Stuff over old prec edge
756 if (n != NULL) n->add_out((Node *)this);
757 }
758
759 //---------------------------add_req_batch-------------------------------------
760 // Add a new required input at the end
add_req_batch(Node * n,uint m)761 void Node::add_req_batch( Node *n, uint m ) {
762 assert( is_not_dead(n), "can not use dead node");
763 // check various edge cases
764 if ((int)m <= 1) {
765 assert((int)m >= 0, "oob");
766 if (m != 0) add_req(n);
767 return;
768 }
769
770 // Look to see if I can move precedence down one without reallocating
771 if( (_cnt+m) > _max || _in[_max-m] )
772 grow( _max+m );
773
774 // Find a precedence edge to move
775 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
776 uint i;
777 for( i=_cnt; i<_max; i++ )
778 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
779 break; // There must be one, since we grew the array
780 // Slide all the precs over by m positions (assume #prec << m).
781 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
782 }
783
784 // Stuff over the old prec edges
785 for(uint i=0; i<m; i++ ) {
786 _in[_cnt++] = n;
787 }
788
789 // Insert multiple out edges on the node.
790 if (n != NULL && !n->is_top()) {
791 for(uint i=0; i<m; i++ ) {
792 n->add_out((Node *)this);
793 }
794 }
795 }
796
797 //------------------------------del_req----------------------------------------
798 // Delete the required edge and compact the edge array
del_req(uint idx)799 void Node::del_req( uint idx ) {
800 assert( idx < _cnt, "oob");
801 assert( !VerifyHashTableKeys || _hash_lock == 0,
802 "remove node from hash table before modifying it");
803 // First remove corresponding def-use edge
804 Node *n = in(idx);
805 if (n != NULL) n->del_out((Node *)this);
806 _in[idx] = in(--_cnt); // Compact the array
807 // Avoid spec violation: Gap in prec edges.
808 close_prec_gap_at(_cnt);
809 Compile::current()->record_modified_node(this);
810 }
811
812 //------------------------------del_req_ordered--------------------------------
813 // Delete the required edge and compact the edge array with preserved order
del_req_ordered(uint idx)814 void Node::del_req_ordered( uint idx ) {
815 assert( idx < _cnt, "oob");
816 assert( !VerifyHashTableKeys || _hash_lock == 0,
817 "remove node from hash table before modifying it");
818 // First remove corresponding def-use edge
819 Node *n = in(idx);
820 if (n != NULL) n->del_out((Node *)this);
821 if (idx < --_cnt) { // Not last edge ?
822 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
823 }
824 // Avoid spec violation: Gap in prec edges.
825 close_prec_gap_at(_cnt);
826 Compile::current()->record_modified_node(this);
827 }
828
829 //------------------------------ins_req----------------------------------------
830 // Insert a new required input at the end
ins_req(uint idx,Node * n)831 void Node::ins_req( uint idx, Node *n ) {
832 assert( is_not_dead(n), "can not use dead node");
833 add_req(NULL); // Make space
834 assert( idx < _max, "Must have allocated enough space");
835 // Slide over
836 if(_cnt-idx-1 > 0) {
837 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
838 }
839 _in[idx] = n; // Stuff over old required edge
840 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
841 }
842
843 //-----------------------------find_edge---------------------------------------
find_edge(Node * n)844 int Node::find_edge(Node* n) {
845 for (uint i = 0; i < len(); i++) {
846 if (_in[i] == n) return i;
847 }
848 return -1;
849 }
850
851 //----------------------------replace_edge-------------------------------------
replace_edge(Node * old,Node * neww)852 int Node::replace_edge(Node* old, Node* neww) {
853 if (old == neww) return 0; // nothing to do
854 uint nrep = 0;
855 for (uint i = 0; i < len(); i++) {
856 if (in(i) == old) {
857 if (i < req()) {
858 set_req(i, neww);
859 } else {
860 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
861 set_prec(i, neww);
862 }
863 nrep++;
864 }
865 }
866 return nrep;
867 }
868
869 /**
870 * Replace input edges in the range pointing to 'old' node.
871 */
replace_edges_in_range(Node * old,Node * neww,int start,int end)872 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
873 if (old == neww) return 0; // nothing to do
874 uint nrep = 0;
875 for (int i = start; i < end; i++) {
876 if (in(i) == old) {
877 set_req(i, neww);
878 nrep++;
879 }
880 }
881 return nrep;
882 }
883
884 //-------------------------disconnect_inputs-----------------------------------
885 // NULL out all inputs to eliminate incoming Def-Use edges.
886 // Return the number of edges between 'n' and 'this'
disconnect_inputs(Node * n,Compile * C)887 int Node::disconnect_inputs(Node *n, Compile* C) {
888 int edges_to_n = 0;
889
890 uint cnt = req();
891 for( uint i = 0; i < cnt; ++i ) {
892 if( in(i) == 0 ) continue;
893 if( in(i) == n ) ++edges_to_n;
894 set_req(i, NULL);
895 }
896 // Remove precedence edges if any exist
897 // Note: Safepoints may have precedence edges, even during parsing
898 if( (req() != len()) && (in(req()) != NULL) ) {
899 uint max = len();
900 for( uint i = 0; i < max; ++i ) {
901 if( in(i) == 0 ) continue;
902 if( in(i) == n ) ++edges_to_n;
903 set_prec(i, NULL);
904 }
905 }
906
907 // Node::destruct requires all out edges be deleted first
908 // debug_only(destruct();) // no reuse benefit expected
909 if (edges_to_n == 0) {
910 C->record_dead_node(_idx);
911 }
912 return edges_to_n;
913 }
914
915 //-----------------------------uncast---------------------------------------
916 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
917 // Strip away casting. (It is depth-limited.)
918 // Optionally, keep casts with dependencies.
uncast(bool keep_deps) const919 Node* Node::uncast(bool keep_deps) const {
920 // Should be inline:
921 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
922 if (is_ConstraintCast()) {
923 return uncast_helper(this, keep_deps);
924 } else {
925 return (Node*) this;
926 }
927 }
928
929 // Find out of current node that matches opcode.
find_out_with(int opcode)930 Node* Node::find_out_with(int opcode) {
931 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
932 Node* use = fast_out(i);
933 if (use->Opcode() == opcode) {
934 return use;
935 }
936 }
937 return NULL;
938 }
939
940 // Return true if the current node has an out that matches opcode.
has_out_with(int opcode)941 bool Node::has_out_with(int opcode) {
942 return (find_out_with(opcode) != NULL);
943 }
944
945 // Return true if the current node has an out that matches any of the opcodes.
has_out_with(int opcode1,int opcode2,int opcode3,int opcode4)946 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
947 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
948 int opcode = fast_out(i)->Opcode();
949 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
950 return true;
951 }
952 }
953 return false;
954 }
955
956
957 //---------------------------uncast_helper-------------------------------------
uncast_helper(const Node * p,bool keep_deps)958 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
959 #ifdef ASSERT
960 uint depth_count = 0;
961 const Node* orig_p = p;
962 #endif
963
964 while (true) {
965 #ifdef ASSERT
966 if (depth_count >= K) {
967 orig_p->dump(4);
968 if (p != orig_p)
969 p->dump(1);
970 }
971 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
972 #endif
973 if (p == NULL || p->req() != 2) {
974 break;
975 } else if (p->is_ConstraintCast()) {
976 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
977 break; // stop at casts with dependencies
978 }
979 p = p->in(1);
980 } else {
981 break;
982 }
983 }
984 return (Node*) p;
985 }
986
987 //------------------------------add_prec---------------------------------------
988 // Add a new precedence input. Precedence inputs are unordered, with
989 // duplicates removed and NULLs packed down at the end.
add_prec(Node * n)990 void Node::add_prec( Node *n ) {
991 assert( is_not_dead(n), "can not use dead node");
992
993 // Check for NULL at end
994 if( _cnt >= _max || in(_max-1) )
995 grow( _max+1 );
996
997 // Find a precedence edge to move
998 uint i = _cnt;
999 while( in(i) != NULL ) {
1000 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1001 i++;
1002 }
1003 _in[i] = n; // Stuff prec edge over NULL
1004 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
1005
1006 #ifdef ASSERT
1007 while ((++i)<_max) { assert(_in[i] == NULL, "spec violation: Gap in prec edges (node %d)", _idx); }
1008 #endif
1009 }
1010
1011 //------------------------------rm_prec----------------------------------------
1012 // Remove a precedence input. Precedence inputs are unordered, with
1013 // duplicates removed and NULLs packed down at the end.
rm_prec(uint j)1014 void Node::rm_prec( uint j ) {
1015 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1016 assert(j >= _cnt, "not a precedence edge");
1017 if (_in[j] == NULL) return; // Avoid spec violation: Gap in prec edges.
1018 _in[j]->del_out((Node *)this);
1019 close_prec_gap_at(j);
1020 }
1021
1022 //------------------------------size_of----------------------------------------
size_of() const1023 uint Node::size_of() const { return sizeof(*this); }
1024
1025 //------------------------------ideal_reg--------------------------------------
ideal_reg() const1026 uint Node::ideal_reg() const { return 0; }
1027
1028 //------------------------------jvms-------------------------------------------
jvms() const1029 JVMState* Node::jvms() const { return NULL; }
1030
1031 #ifdef ASSERT
1032 //------------------------------jvms-------------------------------------------
verify_jvms(const JVMState * using_jvms) const1033 bool Node::verify_jvms(const JVMState* using_jvms) const {
1034 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
1035 if (jvms == using_jvms) return true;
1036 }
1037 return false;
1038 }
1039
1040 //------------------------------init_NodeProperty------------------------------
init_NodeProperty()1041 void Node::init_NodeProperty() {
1042 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
1043 assert(max_flags() <= max_jushort, "too many NodeProperty flags");
1044 }
1045
1046 //-----------------------------max_flags---------------------------------------
max_flags()1047 juint Node::max_flags() {
1048 return (PD::_last_flag << 1) - 1; // allow flags combination
1049 }
1050 #endif
1051
1052 //------------------------------format-----------------------------------------
1053 // Print as assembly
format(PhaseRegAlloc *,outputStream * st) const1054 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1055 //------------------------------emit-------------------------------------------
1056 // Emit bytes starting at parameter 'ptr'.
emit(CodeBuffer & cbuf,PhaseRegAlloc * ra_) const1057 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
1058 //------------------------------size-------------------------------------------
1059 // Size of instruction in bytes
size(PhaseRegAlloc * ra_) const1060 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1061
1062 //------------------------------CFG Construction-------------------------------
1063 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1064 // Goto and Return.
is_block_proj() const1065 const Node *Node::is_block_proj() const { return 0; }
1066
1067 // Minimum guaranteed type
bottom_type() const1068 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1069
1070
1071 //------------------------------raise_bottom_type------------------------------
1072 // Get the worst-case Type output for this Node.
raise_bottom_type(const Type * new_type)1073 void Node::raise_bottom_type(const Type* new_type) {
1074 if (is_Type()) {
1075 TypeNode *n = this->as_Type();
1076 if (VerifyAliases) {
1077 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1078 }
1079 n->set_type(new_type);
1080 } else if (is_Load()) {
1081 LoadNode *n = this->as_Load();
1082 if (VerifyAliases) {
1083 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1084 }
1085 n->set_type(new_type);
1086 }
1087 }
1088
1089 //------------------------------Identity---------------------------------------
1090 // Return a node that the given node is equivalent to.
Identity(PhaseGVN * phase)1091 Node* Node::Identity(PhaseGVN* phase) {
1092 return this; // Default to no identities
1093 }
1094
1095 //------------------------------Value------------------------------------------
1096 // Compute a new Type for a node using the Type of the inputs.
Value(PhaseGVN * phase) const1097 const Type* Node::Value(PhaseGVN* phase) const {
1098 return bottom_type(); // Default to worst-case Type
1099 }
1100
1101 //------------------------------Ideal------------------------------------------
1102 //
1103 // 'Idealize' the graph rooted at this Node.
1104 //
1105 // In order to be efficient and flexible there are some subtle invariants
1106 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1107 // these invariants, although its too slow to have on by default. If you are
1108 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1109 //
1110 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1111 // pointer. If ANY change is made, it must return the root of the reshaped
1112 // graph - even if the root is the same Node. Example: swapping the inputs
1113 // to an AddINode gives the same answer and same root, but you still have to
1114 // return the 'this' pointer instead of NULL.
1115 //
1116 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1117 // Identity call to return an old Node; basically if Identity can find
1118 // another Node have the Ideal call make no change and return NULL.
1119 // Example: AddINode::Ideal must check for add of zero; in this case it
1120 // returns NULL instead of doing any graph reshaping.
1121 //
1122 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1123 // sharing there may be other users of the old Nodes relying on their current
1124 // semantics. Modifying them will break the other users.
1125 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1126 // "X+3" unchanged in case it is shared.
1127 //
1128 // If you modify the 'this' pointer's inputs, you should use
1129 // 'set_req'. If you are making a new Node (either as the new root or
1130 // some new internal piece) you may use 'init_req' to set the initial
1131 // value. You can make a new Node with either 'new' or 'clone'. In
1132 // either case, def-use info is correctly maintained.
1133 //
1134 // Example: reshape "(X+3)+4" into "X+7":
1135 // set_req(1, in(1)->in(1));
1136 // set_req(2, phase->intcon(7));
1137 // return this;
1138 // Example: reshape "X*4" into "X<<2"
1139 // return new LShiftINode(in(1), phase->intcon(2));
1140 //
1141 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1142 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1143 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1144 // return new AddINode(shift, in(1));
1145 //
1146 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1147 // These forms are faster than 'phase->transform(new ConNode())' and Do
1148 // The Right Thing with def-use info.
1149 //
1150 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1151 // graph uses the 'this' Node it must be the root. If you want a Node with
1152 // the same Opcode as the 'this' pointer use 'clone'.
1153 //
Ideal(PhaseGVN * phase,bool can_reshape)1154 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1155 return NULL; // Default to being Ideal already
1156 }
1157
1158 // Some nodes have specific Ideal subgraph transformations only if they are
1159 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1160 // for the transformations to happen.
has_special_unique_user() const1161 bool Node::has_special_unique_user() const {
1162 assert(outcnt() == 1, "match only for unique out");
1163 Node* n = unique_out();
1164 int op = Opcode();
1165 if (this->is_Store()) {
1166 // Condition for back-to-back stores folding.
1167 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1168 } else if (this->is_Load() || this->is_DecodeN() || this->is_Phi()) {
1169 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1170 return n->Opcode() == Op_MemBarAcquire;
1171 } else if (op == Op_AddL) {
1172 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1173 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1174 } else if (op == Op_SubI || op == Op_SubL) {
1175 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1176 return n->Opcode() == op && n->in(2) == this;
1177 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1178 // See IfProjNode::Identity()
1179 return true;
1180 } else {
1181 return false;
1182 }
1183 };
1184
1185 //--------------------------find_exact_control---------------------------------
1186 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
find_exact_control(Node * ctrl)1187 Node* Node::find_exact_control(Node* ctrl) {
1188 if (ctrl == NULL && this->is_Region())
1189 ctrl = this->as_Region()->is_copy();
1190
1191 if (ctrl != NULL && ctrl->is_CatchProj()) {
1192 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1193 ctrl = ctrl->in(0);
1194 if (ctrl != NULL && !ctrl->is_top())
1195 ctrl = ctrl->in(0);
1196 }
1197
1198 if (ctrl != NULL && ctrl->is_Proj())
1199 ctrl = ctrl->in(0);
1200
1201 return ctrl;
1202 }
1203
1204 //--------------------------dominates------------------------------------------
1205 // Helper function for MemNode::all_controls_dominate().
1206 // Check if 'this' control node dominates or equal to 'sub' control node.
1207 // We already know that if any path back to Root or Start reaches 'this',
1208 // then all paths so, so this is a simple search for one example,
1209 // not an exhaustive search for a counterexample.
dominates(Node * sub,Node_List & nlist)1210 bool Node::dominates(Node* sub, Node_List &nlist) {
1211 assert(this->is_CFG(), "expecting control");
1212 assert(sub != NULL && sub->is_CFG(), "expecting control");
1213
1214 // detect dead cycle without regions
1215 int iterations_without_region_limit = DominatorSearchLimit;
1216
1217 Node* orig_sub = sub;
1218 Node* dom = this;
1219 bool met_dom = false;
1220 nlist.clear();
1221
1222 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1223 // After seeing 'dom', continue up to Root or Start.
1224 // If we hit a region (backward split point), it may be a loop head.
1225 // Keep going through one of the region's inputs. If we reach the
1226 // same region again, go through a different input. Eventually we
1227 // will either exit through the loop head, or give up.
1228 // (If we get confused, break out and return a conservative 'false'.)
1229 while (sub != NULL) {
1230 if (sub->is_top()) break; // Conservative answer for dead code.
1231 if (sub == dom) {
1232 if (nlist.size() == 0) {
1233 // No Region nodes except loops were visited before and the EntryControl
1234 // path was taken for loops: it did not walk in a cycle.
1235 return true;
1236 } else if (met_dom) {
1237 break; // already met before: walk in a cycle
1238 } else {
1239 // Region nodes were visited. Continue walk up to Start or Root
1240 // to make sure that it did not walk in a cycle.
1241 met_dom = true; // first time meet
1242 iterations_without_region_limit = DominatorSearchLimit; // Reset
1243 }
1244 }
1245 if (sub->is_Start() || sub->is_Root()) {
1246 // Success if we met 'dom' along a path to Start or Root.
1247 // We assume there are no alternative paths that avoid 'dom'.
1248 // (This assumption is up to the caller to ensure!)
1249 return met_dom;
1250 }
1251 Node* up = sub->in(0);
1252 // Normalize simple pass-through regions and projections:
1253 up = sub->find_exact_control(up);
1254 // If sub == up, we found a self-loop. Try to push past it.
1255 if (sub == up && sub->is_Loop()) {
1256 // Take loop entry path on the way up to 'dom'.
1257 up = sub->in(1); // in(LoopNode::EntryControl);
1258 } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1259 // Take in(1) path on the way up to 'dom' for regions with only one input
1260 up = sub->in(1);
1261 } else if (sub == up && sub->is_Region() && sub->req() == 3) {
1262 // Try both paths for Regions with 2 input paths (it may be a loop head).
1263 // It could give conservative 'false' answer without information
1264 // which region's input is the entry path.
1265 iterations_without_region_limit = DominatorSearchLimit; // Reset
1266
1267 bool region_was_visited_before = false;
1268 // Was this Region node visited before?
1269 // If so, we have reached it because we accidentally took a
1270 // loop-back edge from 'sub' back into the body of the loop,
1271 // and worked our way up again to the loop header 'sub'.
1272 // So, take the first unexplored path on the way up to 'dom'.
1273 for (int j = nlist.size() - 1; j >= 0; j--) {
1274 intptr_t ni = (intptr_t)nlist.at(j);
1275 Node* visited = (Node*)(ni & ~1);
1276 bool visited_twice_already = ((ni & 1) != 0);
1277 if (visited == sub) {
1278 if (visited_twice_already) {
1279 // Visited 2 paths, but still stuck in loop body. Give up.
1280 return false;
1281 }
1282 // The Region node was visited before only once.
1283 // (We will repush with the low bit set, below.)
1284 nlist.remove(j);
1285 // We will find a new edge and re-insert.
1286 region_was_visited_before = true;
1287 break;
1288 }
1289 }
1290
1291 // Find an incoming edge which has not been seen yet; walk through it.
1292 assert(up == sub, "");
1293 uint skip = region_was_visited_before ? 1 : 0;
1294 for (uint i = 1; i < sub->req(); i++) {
1295 Node* in = sub->in(i);
1296 if (in != NULL && !in->is_top() && in != sub) {
1297 if (skip == 0) {
1298 up = in;
1299 break;
1300 }
1301 --skip; // skip this nontrivial input
1302 }
1303 }
1304
1305 // Set 0 bit to indicate that both paths were taken.
1306 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1307 }
1308
1309 if (up == sub) {
1310 break; // some kind of tight cycle
1311 }
1312 if (up == orig_sub && met_dom) {
1313 // returned back after visiting 'dom'
1314 break; // some kind of cycle
1315 }
1316 if (--iterations_without_region_limit < 0) {
1317 break; // dead cycle
1318 }
1319 sub = up;
1320 }
1321
1322 // Did not meet Root or Start node in pred. chain.
1323 // Conservative answer for dead code.
1324 return false;
1325 }
1326
1327 //------------------------------remove_dead_region-----------------------------
1328 // This control node is dead. Follow the subgraph below it making everything
1329 // using it dead as well. This will happen normally via the usual IterGVN
1330 // worklist but this call is more efficient. Do not update use-def info
1331 // inside the dead region, just at the borders.
kill_dead_code(Node * dead,PhaseIterGVN * igvn)1332 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1333 // Con's are a popular node to re-hit in the hash table again.
1334 if( dead->is_Con() ) return;
1335
1336 ResourceMark rm;
1337 Node_List nstack(Thread::current()->resource_area());
1338
1339 Node *top = igvn->C->top();
1340 nstack.push(dead);
1341 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1342
1343 while (nstack.size() > 0) {
1344 dead = nstack.pop();
1345 if (dead->Opcode() == Op_SafePoint) {
1346 dead->as_SafePoint()->disconnect_from_root(igvn);
1347 }
1348 if (dead->outcnt() > 0) {
1349 // Keep dead node on stack until all uses are processed.
1350 nstack.push(dead);
1351 // For all Users of the Dead... ;-)
1352 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1353 Node* use = dead->last_out(k);
1354 igvn->hash_delete(use); // Yank from hash table prior to mod
1355 if (use->in(0) == dead) { // Found another dead node
1356 assert (!use->is_Con(), "Control for Con node should be Root node.");
1357 use->set_req(0, top); // Cut dead edge to prevent processing
1358 nstack.push(use); // the dead node again.
1359 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1360 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1361 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1362 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1363 use->set_req(0, top); // Cut self edge
1364 nstack.push(use);
1365 } else { // Else found a not-dead user
1366 // Dead if all inputs are top or null
1367 bool dead_use = !use->is_Root(); // Keep empty graph alive
1368 for (uint j = 1; j < use->req(); j++) {
1369 Node* in = use->in(j);
1370 if (in == dead) { // Turn all dead inputs into TOP
1371 use->set_req(j, top);
1372 } else if (in != NULL && !in->is_top()) {
1373 dead_use = false;
1374 }
1375 }
1376 if (dead_use) {
1377 if (use->is_Region()) {
1378 use->set_req(0, top); // Cut self edge
1379 }
1380 nstack.push(use);
1381 } else {
1382 igvn->_worklist.push(use);
1383 }
1384 }
1385 // Refresh the iterator, since any number of kills might have happened.
1386 k = dead->last_outs(kmin);
1387 }
1388 } else { // (dead->outcnt() == 0)
1389 // Done with outputs.
1390 igvn->hash_delete(dead);
1391 igvn->_worklist.remove(dead);
1392 igvn->C->remove_modified_node(dead);
1393 igvn->set_type(dead, Type::TOP);
1394 if (dead->is_macro()) {
1395 igvn->C->remove_macro_node(dead);
1396 }
1397 if (dead->is_expensive()) {
1398 igvn->C->remove_expensive_node(dead);
1399 }
1400 CastIINode* cast = dead->isa_CastII();
1401 if (cast != NULL && cast->has_range_check()) {
1402 igvn->C->remove_range_check_cast(cast);
1403 }
1404 if (dead->Opcode() == Op_Opaque4) {
1405 igvn->C->remove_opaque4_node(dead);
1406 }
1407 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1408 bs->unregister_potential_barrier_node(dead);
1409 igvn->C->record_dead_node(dead->_idx);
1410 // Kill all inputs to the dead guy
1411 for (uint i=0; i < dead->req(); i++) {
1412 Node *n = dead->in(i); // Get input to dead guy
1413 if (n != NULL && !n->is_top()) { // Input is valid?
1414 dead->set_req(i, top); // Smash input away
1415 if (n->outcnt() == 0) { // Input also goes dead?
1416 if (!n->is_Con())
1417 nstack.push(n); // Clear it out as well
1418 } else if (n->outcnt() == 1 &&
1419 n->has_special_unique_user()) {
1420 igvn->add_users_to_worklist( n );
1421 } else if (n->outcnt() <= 2 && n->is_Store()) {
1422 // Push store's uses on worklist to enable folding optimization for
1423 // store/store and store/load to the same address.
1424 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1425 // and remove_globally_dead_node().
1426 igvn->add_users_to_worklist( n );
1427 } else {
1428 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1429 }
1430 }
1431 }
1432 } // (dead->outcnt() == 0)
1433 } // while (nstack.size() > 0) for outputs
1434 return;
1435 }
1436
1437 //------------------------------remove_dead_region-----------------------------
remove_dead_region(PhaseGVN * phase,bool can_reshape)1438 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1439 Node *n = in(0);
1440 if( !n ) return false;
1441 // Lost control into this guy? I.e., it became unreachable?
1442 // Aggressively kill all unreachable code.
1443 if (can_reshape && n->is_top()) {
1444 kill_dead_code(this, phase->is_IterGVN());
1445 return false; // Node is dead.
1446 }
1447
1448 if( n->is_Region() && n->as_Region()->is_copy() ) {
1449 Node *m = n->nonnull_req();
1450 set_req(0, m);
1451 return true;
1452 }
1453 return false;
1454 }
1455
1456 //------------------------------hash-------------------------------------------
1457 // Hash function over Nodes.
hash() const1458 uint Node::hash() const {
1459 uint sum = 0;
1460 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1461 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1462 return (sum>>2) + _cnt + Opcode();
1463 }
1464
1465 //------------------------------cmp--------------------------------------------
1466 // Compare special parts of simple Nodes
cmp(const Node & n) const1467 bool Node::cmp( const Node &n ) const {
1468 return true; // Must be same
1469 }
1470
1471 //------------------------------rematerialize-----------------------------------
1472 // Should we clone rather than spill this instruction?
rematerialize() const1473 bool Node::rematerialize() const {
1474 if ( is_Mach() )
1475 return this->as_Mach()->rematerialize();
1476 else
1477 return (_flags & Flag_rematerialize) != 0;
1478 }
1479
1480 //------------------------------needs_anti_dependence_check---------------------
1481 // Nodes which use memory without consuming it, hence need antidependences.
needs_anti_dependence_check() const1482 bool Node::needs_anti_dependence_check() const {
1483 if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1484 return false;
1485 }
1486 return in(1)->bottom_type()->has_memory();
1487 }
1488
1489 // Get an integer constant from a ConNode (or CastIINode).
1490 // Return a default value if there is no apparent constant here.
find_int_type() const1491 const TypeInt* Node::find_int_type() const {
1492 if (this->is_Type()) {
1493 return this->as_Type()->type()->isa_int();
1494 } else if (this->is_Con()) {
1495 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1496 return this->bottom_type()->isa_int();
1497 }
1498 return NULL;
1499 }
1500
1501 // Get a pointer constant from a ConstNode.
1502 // Returns the constant if it is a pointer ConstNode
get_ptr() const1503 intptr_t Node::get_ptr() const {
1504 assert( Opcode() == Op_ConP, "" );
1505 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1506 }
1507
1508 // Get a narrow oop constant from a ConNNode.
get_narrowcon() const1509 intptr_t Node::get_narrowcon() const {
1510 assert( Opcode() == Op_ConN, "" );
1511 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1512 }
1513
1514 // Get a long constant from a ConNode.
1515 // Return a default value if there is no apparent constant here.
find_long_type() const1516 const TypeLong* Node::find_long_type() const {
1517 if (this->is_Type()) {
1518 return this->as_Type()->type()->isa_long();
1519 } else if (this->is_Con()) {
1520 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1521 return this->bottom_type()->isa_long();
1522 }
1523 return NULL;
1524 }
1525
1526
1527 /**
1528 * Return a ptr type for nodes which should have it.
1529 */
get_ptr_type() const1530 const TypePtr* Node::get_ptr_type() const {
1531 const TypePtr* tp = this->bottom_type()->make_ptr();
1532 #ifdef ASSERT
1533 if (tp == NULL) {
1534 this->dump(1);
1535 assert((tp != NULL), "unexpected node type");
1536 }
1537 #endif
1538 return tp;
1539 }
1540
1541 // Get a double constant from a ConstNode.
1542 // Returns the constant if it is a double ConstNode
getd() const1543 jdouble Node::getd() const {
1544 assert( Opcode() == Op_ConD, "" );
1545 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1546 }
1547
1548 // Get a float constant from a ConstNode.
1549 // Returns the constant if it is a float ConstNode
getf() const1550 jfloat Node::getf() const {
1551 assert( Opcode() == Op_ConF, "" );
1552 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1553 }
1554
1555 #ifndef PRODUCT
1556
1557 //------------------------------find------------------------------------------
1558 // Find a neighbor of this Node with the given _idx
1559 // If idx is negative, find its absolute value, following both _in and _out.
find_recur(Compile * C,Node * & result,Node * n,int idx,bool only_ctrl,VectorSet * old_space,VectorSet * new_space)1560 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1561 VectorSet* old_space, VectorSet* new_space ) {
1562 int node_idx = (idx >= 0) ? idx : -idx;
1563 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1564 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1565 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1566 if( v->test(n->_idx) ) return;
1567 if( (int)n->_idx == node_idx
1568 debug_only(|| n->debug_idx() == node_idx) ) {
1569 if (result != NULL)
1570 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1571 (uintptr_t)result, (uintptr_t)n, node_idx);
1572 result = n;
1573 }
1574 v->set(n->_idx);
1575 for( uint i=0; i<n->len(); i++ ) {
1576 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1577 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1578 }
1579 // Search along forward edges also:
1580 if (idx < 0 && !only_ctrl) {
1581 for( uint j=0; j<n->outcnt(); j++ ) {
1582 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1583 }
1584 }
1585 #ifdef ASSERT
1586 // Search along debug_orig edges last, checking for cycles
1587 Node* orig = n->debug_orig();
1588 if (orig != NULL) {
1589 do {
1590 if (NotANode(orig)) break;
1591 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1592 orig = orig->debug_orig();
1593 } while (orig != NULL && orig != n->debug_orig());
1594 }
1595 #endif //ASSERT
1596 }
1597
1598 // call this from debugger:
find_node(Node * n,int idx)1599 Node* find_node(Node* n, int idx) {
1600 return n->find(idx);
1601 }
1602
1603 // call this from debugger with root node as default:
find_node(int idx)1604 Node* find_node(int idx) {
1605 return Compile::current()->root()->find(idx);
1606 }
1607
1608 //------------------------------find-------------------------------------------
find(int idx) const1609 Node* Node::find(int idx) const {
1610 ResourceArea *area = Thread::current()->resource_area();
1611 VectorSet old_space(area), new_space(area);
1612 Node* result = NULL;
1613 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1614 return result;
1615 }
1616
1617 //------------------------------find_ctrl--------------------------------------
1618 // Find an ancestor to this node in the control history with given _idx
find_ctrl(int idx) const1619 Node* Node::find_ctrl(int idx) const {
1620 ResourceArea *area = Thread::current()->resource_area();
1621 VectorSet old_space(area), new_space(area);
1622 Node* result = NULL;
1623 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1624 return result;
1625 }
1626 #endif
1627
1628
1629
1630 #ifndef PRODUCT
1631
1632 // -----------------------------Name-------------------------------------------
1633 extern const char *NodeClassNames[];
Name() const1634 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1635
is_disconnected(const Node * n)1636 static bool is_disconnected(const Node* n) {
1637 for (uint i = 0; i < n->req(); i++) {
1638 if (n->in(i) != NULL) return false;
1639 }
1640 return true;
1641 }
1642
1643 #ifdef ASSERT
dump_orig(outputStream * st,bool print_key) const1644 void Node::dump_orig(outputStream *st, bool print_key) const {
1645 Compile* C = Compile::current();
1646 Node* orig = _debug_orig;
1647 if (NotANode(orig)) orig = NULL;
1648 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1649 if (orig == NULL) return;
1650 if (print_key) {
1651 st->print(" !orig=");
1652 }
1653 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1654 if (NotANode(fast)) fast = NULL;
1655 while (orig != NULL) {
1656 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1657 if (discon) st->print("[");
1658 if (!Compile::current()->node_arena()->contains(orig))
1659 st->print("o");
1660 st->print("%d", orig->_idx);
1661 if (discon) st->print("]");
1662 orig = orig->debug_orig();
1663 if (NotANode(orig)) orig = NULL;
1664 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1665 if (orig != NULL) st->print(",");
1666 if (fast != NULL) {
1667 // Step fast twice for each single step of orig:
1668 fast = fast->debug_orig();
1669 if (NotANode(fast)) fast = NULL;
1670 if (fast != NULL && fast != orig) {
1671 fast = fast->debug_orig();
1672 if (NotANode(fast)) fast = NULL;
1673 }
1674 if (fast == orig) {
1675 st->print("...");
1676 break;
1677 }
1678 }
1679 }
1680 }
1681
set_debug_orig(Node * orig)1682 void Node::set_debug_orig(Node* orig) {
1683 _debug_orig = orig;
1684 if (BreakAtNode == 0) return;
1685 if (NotANode(orig)) orig = NULL;
1686 int trip = 10;
1687 while (orig != NULL) {
1688 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1689 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1690 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1691 BREAKPOINT;
1692 }
1693 orig = orig->debug_orig();
1694 if (NotANode(orig)) orig = NULL;
1695 if (trip-- <= 0) break;
1696 }
1697 }
1698 #endif //ASSERT
1699
1700 //------------------------------dump------------------------------------------
1701 // Dump a Node
dump(const char * suffix,bool mark,outputStream * st) const1702 void Node::dump(const char* suffix, bool mark, outputStream *st) const {
1703 Compile* C = Compile::current();
1704 bool is_new = C->node_arena()->contains(this);
1705 C->_in_dump_cnt++;
1706 st->print("%c%d%s\t%s\t=== ", is_new ? ' ' : 'o', _idx, mark ? " >" : "", Name());
1707
1708 // Dump the required and precedence inputs
1709 dump_req(st);
1710 dump_prec(st);
1711 // Dump the outputs
1712 dump_out(st);
1713
1714 if (is_disconnected(this)) {
1715 #ifdef ASSERT
1716 st->print(" [%d]",debug_idx());
1717 dump_orig(st);
1718 #endif
1719 st->cr();
1720 C->_in_dump_cnt--;
1721 return; // don't process dead nodes
1722 }
1723
1724 if (C->clone_map().value(_idx) != 0) {
1725 C->clone_map().dump(_idx);
1726 }
1727 // Dump node-specific info
1728 dump_spec(st);
1729 #ifdef ASSERT
1730 // Dump the non-reset _debug_idx
1731 if (Verbose && WizardMode) {
1732 st->print(" [%d]",debug_idx());
1733 }
1734 #endif
1735
1736 const Type *t = bottom_type();
1737
1738 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1739 const TypeInstPtr *toop = t->isa_instptr();
1740 const TypeKlassPtr *tkls = t->isa_klassptr();
1741 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1742 if (klass && klass->is_loaded() && klass->is_interface()) {
1743 st->print(" Interface:");
1744 } else if (toop) {
1745 st->print(" Oop:");
1746 } else if (tkls) {
1747 st->print(" Klass:");
1748 }
1749 t->dump_on(st);
1750 } else if (t == Type::MEMORY) {
1751 st->print(" Memory:");
1752 MemNode::dump_adr_type(this, adr_type(), st);
1753 } else if (Verbose || WizardMode) {
1754 st->print(" Type:");
1755 if (t) {
1756 t->dump_on(st);
1757 } else {
1758 st->print("no type");
1759 }
1760 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1761 // Dump MachSpillcopy vector type.
1762 t->dump_on(st);
1763 }
1764 if (is_new) {
1765 DEBUG_ONLY(dump_orig(st));
1766 Node_Notes* nn = C->node_notes_at(_idx);
1767 if (nn != NULL && !nn->is_clear()) {
1768 if (nn->jvms() != NULL) {
1769 st->print(" !jvms:");
1770 nn->jvms()->dump_spec(st);
1771 }
1772 }
1773 }
1774 if (suffix) st->print("%s", suffix);
1775 C->_in_dump_cnt--;
1776 }
1777
1778 //------------------------------dump_req--------------------------------------
dump_req(outputStream * st) const1779 void Node::dump_req(outputStream *st) const {
1780 // Dump the required input edges
1781 for (uint i = 0; i < req(); i++) { // For all required inputs
1782 Node* d = in(i);
1783 if (d == NULL) {
1784 st->print("_ ");
1785 } else if (NotANode(d)) {
1786 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1787 } else {
1788 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1789 }
1790 }
1791 }
1792
1793
1794 //------------------------------dump_prec-------------------------------------
dump_prec(outputStream * st) const1795 void Node::dump_prec(outputStream *st) const {
1796 // Dump the precedence edges
1797 int any_prec = 0;
1798 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1799 Node* p = in(i);
1800 if (p != NULL) {
1801 if (!any_prec++) st->print(" |");
1802 if (NotANode(p)) { st->print("NotANode "); continue; }
1803 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1804 }
1805 }
1806 }
1807
1808 //------------------------------dump_out--------------------------------------
dump_out(outputStream * st) const1809 void Node::dump_out(outputStream *st) const {
1810 // Delimit the output edges
1811 st->print(" [[");
1812 // Dump the output edges
1813 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1814 Node* u = _out[i];
1815 if (u == NULL) {
1816 st->print("_ ");
1817 } else if (NotANode(u)) {
1818 st->print("NotANode ");
1819 } else {
1820 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1821 }
1822 }
1823 st->print("]] ");
1824 }
1825
1826 //----------------------------collect_nodes_i----------------------------------
1827 // Collects nodes from an Ideal graph, starting from a given start node and
1828 // moving in a given direction until a certain depth (distance from the start
1829 // node) is reached. Duplicates are ignored.
1830 // Arguments:
1831 // nstack: the nodes are collected into this array.
1832 // start: the node at which to start collecting.
1833 // direction: if this is a positive number, collect input nodes; if it is
1834 // a negative number, collect output nodes.
1835 // depth: collect nodes up to this distance from the start node.
1836 // include_start: whether to include the start node in the result collection.
1837 // only_ctrl: whether to regard control edges only during traversal.
1838 // only_data: whether to regard data edges only during traversal.
collect_nodes_i(GrowableArray<Node * > * nstack,const Node * start,int direction,uint depth,bool include_start,bool only_ctrl,bool only_data)1839 static void collect_nodes_i(GrowableArray<Node*> *nstack, const Node* start, int direction, uint depth, bool include_start, bool only_ctrl, bool only_data) {
1840 Node* s = (Node*) start; // remove const
1841 nstack->append(s);
1842 int begin = 0;
1843 int end = 0;
1844 for(uint i = 0; i < depth; i++) {
1845 end = nstack->length();
1846 for(int j = begin; j < end; j++) {
1847 Node* tp = nstack->at(j);
1848 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1849 for(uint k = 0; k < limit; k++) {
1850 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1851
1852 if (NotANode(n)) continue;
1853 // do not recurse through top or the root (would reach unrelated stuff)
1854 if (n->is_Root() || n->is_top()) continue;
1855 if (only_ctrl && !n->is_CFG()) continue;
1856 if (only_data && n->is_CFG()) continue;
1857
1858 bool on_stack = nstack->contains(n);
1859 if (!on_stack) {
1860 nstack->append(n);
1861 }
1862 }
1863 }
1864 begin = end;
1865 }
1866 if (!include_start) {
1867 nstack->remove(s);
1868 }
1869 }
1870
1871 //------------------------------dump_nodes-------------------------------------
dump_nodes(const Node * start,int d,bool only_ctrl)1872 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1873 if (NotANode(start)) return;
1874
1875 GrowableArray <Node *> nstack(Compile::current()->live_nodes());
1876 collect_nodes_i(&nstack, start, d, (uint) ABS(d), true, only_ctrl, false);
1877
1878 int end = nstack.length();
1879 if (d > 0) {
1880 for(int j = end-1; j >= 0; j--) {
1881 nstack.at(j)->dump();
1882 }
1883 } else {
1884 for(int j = 0; j < end; j++) {
1885 nstack.at(j)->dump();
1886 }
1887 }
1888 }
1889
1890 //------------------------------dump-------------------------------------------
dump(int d) const1891 void Node::dump(int d) const {
1892 dump_nodes(this, d, false);
1893 }
1894
1895 //------------------------------dump_ctrl--------------------------------------
1896 // Dump a Node's control history to depth
dump_ctrl(int d) const1897 void Node::dump_ctrl(int d) const {
1898 dump_nodes(this, d, true);
1899 }
1900
1901 //-----------------------------dump_compact------------------------------------
dump_comp() const1902 void Node::dump_comp() const {
1903 this->dump_comp("\n");
1904 }
1905
1906 //-----------------------------dump_compact------------------------------------
1907 // Dump a Node in compact representation, i.e., just print its name and index.
1908 // Nodes can specify additional specifics to print in compact representation by
1909 // implementing dump_compact_spec.
dump_comp(const char * suffix,outputStream * st) const1910 void Node::dump_comp(const char* suffix, outputStream *st) const {
1911 Compile* C = Compile::current();
1912 C->_in_dump_cnt++;
1913 st->print("%s(%d)", Name(), _idx);
1914 this->dump_compact_spec(st);
1915 if (suffix) {
1916 st->print("%s", suffix);
1917 }
1918 C->_in_dump_cnt--;
1919 }
1920
1921 //----------------------------dump_related-------------------------------------
1922 // Dump a Node's related nodes - the notion of "related" depends on the Node at
1923 // hand and is determined by the implementation of the virtual method rel.
dump_related() const1924 void Node::dump_related() const {
1925 Compile* C = Compile::current();
1926 GrowableArray <Node *> in_rel(C->unique());
1927 GrowableArray <Node *> out_rel(C->unique());
1928 this->related(&in_rel, &out_rel, false);
1929 for (int i = in_rel.length() - 1; i >= 0; i--) {
1930 in_rel.at(i)->dump();
1931 }
1932 this->dump("\n", true);
1933 for (int i = 0; i < out_rel.length(); i++) {
1934 out_rel.at(i)->dump();
1935 }
1936 }
1937
1938 //----------------------------dump_related-------------------------------------
1939 // Dump a Node's related nodes up to a given depth (distance from the start
1940 // node).
1941 // Arguments:
1942 // d_in: depth for input nodes.
1943 // d_out: depth for output nodes (note: this also is a positive number).
dump_related(uint d_in,uint d_out) const1944 void Node::dump_related(uint d_in, uint d_out) const {
1945 Compile* C = Compile::current();
1946 GrowableArray <Node *> in_rel(C->unique());
1947 GrowableArray <Node *> out_rel(C->unique());
1948
1949 // call collect_nodes_i directly
1950 collect_nodes_i(&in_rel, this, 1, d_in, false, false, false);
1951 collect_nodes_i(&out_rel, this, -1, d_out, false, false, false);
1952
1953 for (int i = in_rel.length() - 1; i >= 0; i--) {
1954 in_rel.at(i)->dump();
1955 }
1956 this->dump("\n", true);
1957 for (int i = 0; i < out_rel.length(); i++) {
1958 out_rel.at(i)->dump();
1959 }
1960 }
1961
1962 //------------------------dump_related_compact---------------------------------
1963 // Dump a Node's related nodes in compact representation. The notion of
1964 // "related" depends on the Node at hand and is determined by the implementation
1965 // of the virtual method rel.
dump_related_compact() const1966 void Node::dump_related_compact() const {
1967 Compile* C = Compile::current();
1968 GrowableArray <Node *> in_rel(C->unique());
1969 GrowableArray <Node *> out_rel(C->unique());
1970 this->related(&in_rel, &out_rel, true);
1971 int n_in = in_rel.length();
1972 int n_out = out_rel.length();
1973
1974 this->dump_comp(n_in == 0 ? "\n" : " ");
1975 for (int i = 0; i < n_in; i++) {
1976 in_rel.at(i)->dump_comp(i == n_in - 1 ? "\n" : " ");
1977 }
1978 for (int i = 0; i < n_out; i++) {
1979 out_rel.at(i)->dump_comp(i == n_out - 1 ? "\n" : " ");
1980 }
1981 }
1982
1983 //------------------------------related----------------------------------------
1984 // Collect a Node's related nodes. The default behaviour just collects the
1985 // inputs and outputs at depth 1, including both control and data flow edges,
1986 // regardless of whether the presentation is compact or not. For data nodes,
1987 // the default is to collect all data inputs (till level 1 if compact), and
1988 // outputs till level 1.
related(GrowableArray<Node * > * in_rel,GrowableArray<Node * > * out_rel,bool compact) const1989 void Node::related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const {
1990 if (this->is_CFG()) {
1991 collect_nodes_i(in_rel, this, 1, 1, false, false, false);
1992 collect_nodes_i(out_rel, this, -1, 1, false, false, false);
1993 } else {
1994 if (compact) {
1995 this->collect_nodes(in_rel, 1, false, true);
1996 } else {
1997 this->collect_nodes_in_all_data(in_rel, false);
1998 }
1999 this->collect_nodes(out_rel, -1, false, false);
2000 }
2001 }
2002
2003 //---------------------------collect_nodes-------------------------------------
2004 // An entry point to the low-level node collection facility, to start from a
2005 // given node in the graph. The start node is by default not included in the
2006 // result.
2007 // Arguments:
2008 // ns: collect the nodes into this data structure.
2009 // d: the depth (distance from start node) to which nodes should be
2010 // collected. A value >0 indicates input nodes, a value <0, output
2011 // nodes.
2012 // ctrl: include only control nodes.
2013 // data: include only data nodes.
collect_nodes(GrowableArray<Node * > * ns,int d,bool ctrl,bool data) const2014 void Node::collect_nodes(GrowableArray<Node*> *ns, int d, bool ctrl, bool data) const {
2015 if (ctrl && data) {
2016 // ignore nonsensical combination
2017 return;
2018 }
2019 collect_nodes_i(ns, this, d, (uint) ABS(d), false, ctrl, data);
2020 }
2021
2022 //--------------------------collect_nodes_in-----------------------------------
collect_nodes_in(Node * start,GrowableArray<Node * > * ns,bool primary_is_data,bool collect_secondary)2023 static void collect_nodes_in(Node* start, GrowableArray<Node*> *ns, bool primary_is_data, bool collect_secondary) {
2024 // The maximum depth is determined using a BFS that visits all primary (data
2025 // or control) inputs and increments the depth at each level.
2026 uint d_in = 0;
2027 GrowableArray<Node*> nodes(Compile::current()->unique());
2028 nodes.push(start);
2029 int nodes_at_current_level = 1;
2030 int n_idx = 0;
2031 while (nodes_at_current_level > 0) {
2032 // Add all primary inputs reachable from the current level to the list, and
2033 // increase the depth if there were any.
2034 int nodes_at_next_level = 0;
2035 bool nodes_added = false;
2036 while (nodes_at_current_level > 0) {
2037 nodes_at_current_level--;
2038 Node* current = nodes.at(n_idx++);
2039 for (uint i = 0; i < current->len(); i++) {
2040 Node* n = current->in(i);
2041 if (NotANode(n)) {
2042 continue;
2043 }
2044 if ((primary_is_data && n->is_CFG()) || (!primary_is_data && !n->is_CFG())) {
2045 continue;
2046 }
2047 if (!nodes.contains(n)) {
2048 nodes.push(n);
2049 nodes_added = true;
2050 nodes_at_next_level++;
2051 }
2052 }
2053 }
2054 if (nodes_added) {
2055 d_in++;
2056 }
2057 nodes_at_current_level = nodes_at_next_level;
2058 }
2059 start->collect_nodes(ns, d_in, !primary_is_data, primary_is_data);
2060 if (collect_secondary) {
2061 // Now, iterate over the secondary nodes in ns and add the respective
2062 // boundary reachable from them.
2063 GrowableArray<Node*> sns(Compile::current()->unique());
2064 for (GrowableArrayIterator<Node*> it = ns->begin(); it != ns->end(); ++it) {
2065 Node* n = *it;
2066 n->collect_nodes(&sns, 1, primary_is_data, !primary_is_data);
2067 for (GrowableArrayIterator<Node*> d = sns.begin(); d != sns.end(); ++d) {
2068 ns->append_if_missing(*d);
2069 }
2070 sns.clear();
2071 }
2072 }
2073 }
2074
2075 //---------------------collect_nodes_in_all_data-------------------------------
2076 // Collect the entire data input graph. Include the control boundary if
2077 // requested.
2078 // Arguments:
2079 // ns: collect the nodes into this data structure.
2080 // ctrl: if true, include the control boundary.
collect_nodes_in_all_data(GrowableArray<Node * > * ns,bool ctrl) const2081 void Node::collect_nodes_in_all_data(GrowableArray<Node*> *ns, bool ctrl) const {
2082 collect_nodes_in((Node*) this, ns, true, ctrl);
2083 }
2084
2085 //--------------------------collect_nodes_in_all_ctrl--------------------------
2086 // Collect the entire control input graph. Include the data boundary if
2087 // requested.
2088 // ns: collect the nodes into this data structure.
2089 // data: if true, include the control boundary.
collect_nodes_in_all_ctrl(GrowableArray<Node * > * ns,bool data) const2090 void Node::collect_nodes_in_all_ctrl(GrowableArray<Node*> *ns, bool data) const {
2091 collect_nodes_in((Node*) this, ns, false, data);
2092 }
2093
2094 //------------------collect_nodes_out_all_ctrl_boundary------------------------
2095 // Collect the entire output graph until hitting control node boundaries, and
2096 // include those.
collect_nodes_out_all_ctrl_boundary(GrowableArray<Node * > * ns) const2097 void Node::collect_nodes_out_all_ctrl_boundary(GrowableArray<Node*> *ns) const {
2098 // Perform a BFS and stop at control nodes.
2099 GrowableArray<Node*> nodes(Compile::current()->unique());
2100 nodes.push((Node*) this);
2101 while (nodes.length() > 0) {
2102 Node* current = nodes.pop();
2103 if (NotANode(current)) {
2104 continue;
2105 }
2106 ns->append_if_missing(current);
2107 if (!current->is_CFG()) {
2108 for (DUIterator i = current->outs(); current->has_out(i); i++) {
2109 nodes.push(current->out(i));
2110 }
2111 }
2112 }
2113 ns->remove((Node*) this);
2114 }
2115
2116 // VERIFICATION CODE
2117 // For each input edge to a node (ie - for each Use-Def edge), verify that
2118 // there is a corresponding Def-Use edge.
2119 //------------------------------verify_edges-----------------------------------
verify_edges(Unique_Node_List & visited)2120 void Node::verify_edges(Unique_Node_List &visited) {
2121 uint i, j, idx;
2122 int cnt;
2123 Node *n;
2124
2125 // Recursive termination test
2126 if (visited.member(this)) return;
2127 visited.push(this);
2128
2129 // Walk over all input edges, checking for correspondence
2130 for( i = 0; i < len(); i++ ) {
2131 n = in(i);
2132 if (n != NULL && !n->is_top()) {
2133 // Count instances of (Node *)this
2134 cnt = 0;
2135 for (idx = 0; idx < n->_outcnt; idx++ ) {
2136 if (n->_out[idx] == (Node *)this) cnt++;
2137 }
2138 assert( cnt > 0,"Failed to find Def-Use edge." );
2139 // Check for duplicate edges
2140 // walk the input array downcounting the input edges to n
2141 for( j = 0; j < len(); j++ ) {
2142 if( in(j) == n ) cnt--;
2143 }
2144 assert( cnt == 0,"Mismatched edge count.");
2145 } else if (n == NULL) {
2146 assert(i >= req() || i == 0 || is_Region() || is_Phi() || is_ArrayCopy() || (is_Unlock() && i == req()-1)
2147 || (is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
2148 "only region, phi, arraycopy, unlock or membar nodes have null data edges");
2149 } else {
2150 assert(n->is_top(), "sanity");
2151 // Nothing to check.
2152 }
2153 }
2154 // Recursive walk over all input edges
2155 for( i = 0; i < len(); i++ ) {
2156 n = in(i);
2157 if( n != NULL )
2158 in(i)->verify_edges(visited);
2159 }
2160 }
2161
verify_recur(const Node * n,int verify_depth,VectorSet & old_space,VectorSet & new_space)2162 void Node::verify_recur(const Node *n, int verify_depth,
2163 VectorSet &old_space, VectorSet &new_space) {
2164 if ( verify_depth == 0 ) return;
2165 if (verify_depth > 0) --verify_depth;
2166
2167 Compile* C = Compile::current();
2168
2169 // Contained in new_space or old_space?
2170 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
2171 // Check for visited in the proper space. Numberings are not unique
2172 // across spaces so we need a separate VectorSet for each space.
2173 if( v->test_set(n->_idx) ) return;
2174
2175 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2176 if (C->cached_top_node() == NULL)
2177 C->set_cached_top_node((Node*)n);
2178 assert(C->cached_top_node() == n, "TOP node must be unique");
2179 }
2180
2181 for( uint i = 0; i < n->len(); i++ ) {
2182 Node *x = n->in(i);
2183 if (!x || x->is_top()) continue;
2184
2185 // Verify my input has a def-use edge to me
2186 if (true /*VerifyDefUse*/) {
2187 // Count use-def edges from n to x
2188 int cnt = 0;
2189 for( uint j = 0; j < n->len(); j++ )
2190 if( n->in(j) == x )
2191 cnt++;
2192 // Count def-use edges from x to n
2193 uint max = x->_outcnt;
2194 for( uint k = 0; k < max; k++ )
2195 if (x->_out[k] == n)
2196 cnt--;
2197 assert( cnt == 0, "mismatched def-use edge counts" );
2198 }
2199
2200 verify_recur(x, verify_depth, old_space, new_space);
2201 }
2202
2203 }
2204
2205 //------------------------------verify-----------------------------------------
2206 // Check Def-Use info for my subgraph
verify() const2207 void Node::verify() const {
2208 Compile* C = Compile::current();
2209 Node* old_top = C->cached_top_node();
2210 ResourceMark rm;
2211 ResourceArea *area = Thread::current()->resource_area();
2212 VectorSet old_space(area), new_space(area);
2213 verify_recur(this, -1, old_space, new_space);
2214 C->set_cached_top_node(old_top);
2215 }
2216 #endif
2217
2218
2219 //------------------------------walk-------------------------------------------
2220 // Graph walk, with both pre-order and post-order functions
walk(NFunc pre,NFunc post,void * env)2221 void Node::walk(NFunc pre, NFunc post, void *env) {
2222 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
2223 walk_(pre, post, env, visited);
2224 }
2225
walk_(NFunc pre,NFunc post,void * env,VectorSet & visited)2226 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
2227 if( visited.test_set(_idx) ) return;
2228 pre(*this,env); // Call the pre-order walk function
2229 for( uint i=0; i<_max; i++ )
2230 if( in(i) ) // Input exists and is not walked?
2231 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
2232 post(*this,env); // Call the post-order walk function
2233 }
2234
nop(Node &,void *)2235 void Node::nop(Node &, void*) {}
2236
2237 //------------------------------Registers--------------------------------------
2238 // Do we Match on this edge index or not? Generally false for Control
2239 // and true for everything else. Weird for calls & returns.
match_edge(uint idx) const2240 uint Node::match_edge(uint idx) const {
2241 return idx; // True for other than index 0 (control)
2242 }
2243
2244 static RegMask _not_used_at_all;
2245 // Register classes are defined for specific machines
out_RegMask() const2246 const RegMask &Node::out_RegMask() const {
2247 ShouldNotCallThis();
2248 return _not_used_at_all;
2249 }
2250
in_RegMask(uint) const2251 const RegMask &Node::in_RegMask(uint) const {
2252 ShouldNotCallThis();
2253 return _not_used_at_all;
2254 }
2255
2256 //=============================================================================
2257 //-----------------------------------------------------------------------------
reset(Arena * new_arena)2258 void Node_Array::reset( Arena *new_arena ) {
2259 _a->Afree(_nodes,_max*sizeof(Node*));
2260 _max = 0;
2261 _nodes = NULL;
2262 _a = new_arena;
2263 }
2264
2265 //------------------------------clear------------------------------------------
2266 // Clear all entries in _nodes to NULL but keep storage
clear()2267 void Node_Array::clear() {
2268 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
2269 }
2270
2271 //-----------------------------------------------------------------------------
grow(uint i)2272 void Node_Array::grow( uint i ) {
2273 if( !_max ) {
2274 _max = 1;
2275 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
2276 _nodes[0] = NULL;
2277 }
2278 uint old = _max;
2279 _max = next_power_of_2(i);
2280 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2281 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2282 }
2283
2284 //-----------------------------------------------------------------------------
insert(uint i,Node * n)2285 void Node_Array::insert( uint i, Node *n ) {
2286 if( _nodes[_max-1] ) grow(_max); // Get more space if full
2287 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
2288 _nodes[i] = n;
2289 }
2290
2291 //-----------------------------------------------------------------------------
remove(uint i)2292 void Node_Array::remove( uint i ) {
2293 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
2294 _nodes[_max-1] = NULL;
2295 }
2296
2297 //-----------------------------------------------------------------------------
sort(C_sort_func_t func)2298 void Node_Array::sort( C_sort_func_t func) {
2299 qsort( _nodes, _max, sizeof( Node* ), func );
2300 }
2301
2302 //-----------------------------------------------------------------------------
dump() const2303 void Node_Array::dump() const {
2304 #ifndef PRODUCT
2305 for( uint i = 0; i < _max; i++ ) {
2306 Node *nn = _nodes[i];
2307 if( nn != NULL ) {
2308 tty->print("%5d--> ",i); nn->dump();
2309 }
2310 }
2311 #endif
2312 }
2313
2314 //--------------------------is_iteratively_computed------------------------------
2315 // Operation appears to be iteratively computed (such as an induction variable)
2316 // It is possible for this operation to return false for a loop-varying
2317 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
is_iteratively_computed()2318 bool Node::is_iteratively_computed() {
2319 if (ideal_reg()) { // does operation have a result register?
2320 for (uint i = 1; i < req(); i++) {
2321 Node* n = in(i);
2322 if (n != NULL && n->is_Phi()) {
2323 for (uint j = 1; j < n->req(); j++) {
2324 if (n->in(j) == this) {
2325 return true;
2326 }
2327 }
2328 }
2329 }
2330 }
2331 return false;
2332 }
2333
2334 //--------------------------find_similar------------------------------
2335 // Return a node with opcode "opc" and same inputs as "this" if one can
2336 // be found; Otherwise return NULL;
find_similar(int opc)2337 Node* Node::find_similar(int opc) {
2338 if (req() >= 2) {
2339 Node* def = in(1);
2340 if (def && def->outcnt() >= 2) {
2341 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2342 Node* use = def->fast_out(i);
2343 if (use != this &&
2344 use->Opcode() == opc &&
2345 use->req() == req()) {
2346 uint j;
2347 for (j = 0; j < use->req(); j++) {
2348 if (use->in(j) != in(j)) {
2349 break;
2350 }
2351 }
2352 if (j == use->req()) {
2353 return use;
2354 }
2355 }
2356 }
2357 }
2358 }
2359 return NULL;
2360 }
2361
2362
2363 //--------------------------unique_ctrl_out------------------------------
2364 // Return the unique control out if only one. Null if none or more than one.
unique_ctrl_out() const2365 Node* Node::unique_ctrl_out() const {
2366 Node* found = NULL;
2367 for (uint i = 0; i < outcnt(); i++) {
2368 Node* use = raw_out(i);
2369 if (use->is_CFG() && use != this) {
2370 if (found != NULL) return NULL;
2371 found = use;
2372 }
2373 }
2374 return found;
2375 }
2376
ensure_control_or_add_prec(Node * c)2377 void Node::ensure_control_or_add_prec(Node* c) {
2378 if (in(0) == NULL) {
2379 set_req(0, c);
2380 } else if (in(0) != c) {
2381 add_prec(c);
2382 }
2383 }
2384
2385 //=============================================================================
2386 //------------------------------yank-------------------------------------------
2387 // Find and remove
yank(Node * n)2388 void Node_List::yank( Node *n ) {
2389 uint i;
2390 for( i = 0; i < _cnt; i++ )
2391 if( _nodes[i] == n )
2392 break;
2393
2394 if( i < _cnt )
2395 _nodes[i] = _nodes[--_cnt];
2396 }
2397
2398 //------------------------------dump-------------------------------------------
dump() const2399 void Node_List::dump() const {
2400 #ifndef PRODUCT
2401 for( uint i = 0; i < _cnt; i++ )
2402 if( _nodes[i] ) {
2403 tty->print("%5d--> ",i);
2404 _nodes[i]->dump();
2405 }
2406 #endif
2407 }
2408
dump_simple() const2409 void Node_List::dump_simple() const {
2410 #ifndef PRODUCT
2411 for( uint i = 0; i < _cnt; i++ )
2412 if( _nodes[i] ) {
2413 tty->print(" %d", _nodes[i]->_idx);
2414 } else {
2415 tty->print(" NULL");
2416 }
2417 #endif
2418 }
2419
2420 //=============================================================================
2421 //------------------------------remove-----------------------------------------
remove(Node * n)2422 void Unique_Node_List::remove(Node* n) {
2423 if (_in_worklist.test(n->_idx)) {
2424 for (uint i = 0; i < size(); i++) {
2425 if (_nodes[i] == n) {
2426 map(i, Node_List::pop());
2427 _in_worklist.remove(n->_idx);
2428 return;
2429 }
2430 }
2431 ShouldNotReachHere();
2432 }
2433 }
2434
2435 //-----------------------remove_useless_nodes----------------------------------
2436 // Remove useless nodes from worklist
remove_useless_nodes(VectorSet & useful)2437 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2438
2439 for (uint i = 0; i < size(); ++i) {
2440 Node *n = at(i);
2441 assert( n != NULL, "Did not expect null entries in worklist");
2442 if (!useful.test(n->_idx)) {
2443 _in_worklist.remove(n->_idx);
2444 map(i,Node_List::pop());
2445 // Node *replacement = Node_List::pop();
2446 // if( i != size() ) { // Check if removing last entry
2447 // _nodes[i] = replacement;
2448 // }
2449 --i; // Visit popped node
2450 // If it was last entry, loop terminates since size() was also reduced
2451 }
2452 }
2453 }
2454
2455 //=============================================================================
grow()2456 void Node_Stack::grow() {
2457 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2458 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2459 size_t max = old_max << 1; // max * 2
2460 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2461 _inode_max = _inodes + max;
2462 _inode_top = _inodes + old_top; // restore _top
2463 }
2464
2465 // Node_Stack is used to map nodes.
find(uint idx) const2466 Node* Node_Stack::find(uint idx) const {
2467 uint sz = size();
2468 for (uint i=0; i < sz; i++) {
2469 if (idx == index_at(i) )
2470 return node_at(i);
2471 }
2472 return NULL;
2473 }
2474
2475 //=============================================================================
size_of() const2476 uint TypeNode::size_of() const { return sizeof(*this); }
2477 #ifndef PRODUCT
dump_spec(outputStream * st) const2478 void TypeNode::dump_spec(outputStream *st) const {
2479 if( !Verbose && !WizardMode ) {
2480 // standard dump does this in Verbose and WizardMode
2481 st->print(" #"); _type->dump_on(st);
2482 }
2483 }
2484
dump_compact_spec(outputStream * st) const2485 void TypeNode::dump_compact_spec(outputStream *st) const {
2486 st->print("#");
2487 _type->dump_on(st);
2488 }
2489 #endif
hash() const2490 uint TypeNode::hash() const {
2491 return Node::hash() + _type->hash();
2492 }
cmp(const Node & n) const2493 bool TypeNode::cmp( const Node &n ) const
2494 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
bottom_type() const2495 const Type *TypeNode::bottom_type() const { return _type; }
Value(PhaseGVN * phase) const2496 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
2497
2498 //------------------------------ideal_reg--------------------------------------
ideal_reg() const2499 uint TypeNode::ideal_reg() const {
2500 return _type->ideal_reg();
2501 }
2502