Wed, 27 Jan 2016 09:02:51 +0100
6675699: need comprehensive fix for unconstrained ConvI2L with narrowed type
Summary: Emit CastII to make narrow ConvI2L dependent on the corresponding range check.
Reviewed-by: kvn, roland
1 /*
2 * Copyright (c) 1997, 2014, 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.
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20 * or visit www.oracle.com if you need additional information or have any
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23 */
25 #include "precompiled.hpp"
26 #include "libadt/vectset.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "opto/cfgnode.hpp"
29 #include "opto/connode.hpp"
30 #include "opto/loopnode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/node.hpp"
34 #include "opto/opcodes.hpp"
35 #include "opto/regmask.hpp"
36 #include "opto/type.hpp"
37 #include "utilities/copy.hpp"
39 class RegMask;
40 // #include "phase.hpp"
41 class PhaseTransform;
42 class PhaseGVN;
44 // Arena we are currently building Nodes in
45 const uint Node::NotAMachineReg = 0xffff0000;
47 #ifndef PRODUCT
48 extern int nodes_created;
49 #endif
51 #ifdef ASSERT
53 //-------------------------- construct_node------------------------------------
54 // Set a breakpoint here to identify where a particular node index is built.
55 void Node::verify_construction() {
56 _debug_orig = NULL;
57 int old_debug_idx = Compile::debug_idx();
58 int new_debug_idx = old_debug_idx+1;
59 if (new_debug_idx > 0) {
60 // Arrange that the lowest five decimal digits of _debug_idx
61 // will repeat those of _idx. In case this is somehow pathological,
62 // we continue to assign negative numbers (!) consecutively.
63 const int mod = 100000;
64 int bump = (int)(_idx - new_debug_idx) % mod;
65 if (bump < 0) bump += mod;
66 assert(bump >= 0 && bump < mod, "");
67 new_debug_idx += bump;
68 }
69 Compile::set_debug_idx(new_debug_idx);
70 set_debug_idx( new_debug_idx );
71 assert(Compile::current()->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
72 assert(Compile::current()->live_nodes() < Compile::current()->max_node_limit(), "Live Node limit exceeded limit");
73 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (int)_idx == BreakAtNode)) {
74 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d", _idx, _debug_idx);
75 BREAKPOINT;
76 }
77 #if OPTO_DU_ITERATOR_ASSERT
78 _last_del = NULL;
79 _del_tick = 0;
80 #endif
81 _hash_lock = 0;
82 }
85 // #ifdef ASSERT ...
87 #if OPTO_DU_ITERATOR_ASSERT
88 void DUIterator_Common::sample(const Node* node) {
89 _vdui = VerifyDUIterators;
90 _node = node;
91 _outcnt = node->_outcnt;
92 _del_tick = node->_del_tick;
93 _last = NULL;
94 }
96 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
97 assert(_node == node, "consistent iterator source");
98 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
99 }
101 void DUIterator_Common::verify_resync() {
102 // Ensure that the loop body has just deleted the last guy produced.
103 const Node* node = _node;
104 // Ensure that at least one copy of the last-seen edge was deleted.
105 // Note: It is OK to delete multiple copies of the last-seen edge.
106 // Unfortunately, we have no way to verify that all the deletions delete
107 // that same edge. On this point we must use the Honor System.
108 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
109 assert(node->_last_del == _last, "must have deleted the edge just produced");
110 // We liked this deletion, so accept the resulting outcnt and tick.
111 _outcnt = node->_outcnt;
112 _del_tick = node->_del_tick;
113 }
115 void DUIterator_Common::reset(const DUIterator_Common& that) {
116 if (this == &that) return; // ignore assignment to self
117 if (!_vdui) {
118 // We need to initialize everything, overwriting garbage values.
119 _last = that._last;
120 _vdui = that._vdui;
121 }
122 // Note: It is legal (though odd) for an iterator over some node x
123 // to be reassigned to iterate over another node y. Some doubly-nested
124 // progress loops depend on being able to do this.
125 const Node* node = that._node;
126 // Re-initialize everything, except _last.
127 _node = node;
128 _outcnt = node->_outcnt;
129 _del_tick = node->_del_tick;
130 }
132 void DUIterator::sample(const Node* node) {
133 DUIterator_Common::sample(node); // Initialize the assertion data.
134 _refresh_tick = 0; // No refreshes have happened, as yet.
135 }
137 void DUIterator::verify(const Node* node, bool at_end_ok) {
138 DUIterator_Common::verify(node, at_end_ok);
139 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
140 }
142 void DUIterator::verify_increment() {
143 if (_refresh_tick & 1) {
144 // We have refreshed the index during this loop.
145 // Fix up _idx to meet asserts.
146 if (_idx > _outcnt) _idx = _outcnt;
147 }
148 verify(_node, true);
149 }
151 void DUIterator::verify_resync() {
152 // Note: We do not assert on _outcnt, because insertions are OK here.
153 DUIterator_Common::verify_resync();
154 // Make sure we are still in sync, possibly with no more out-edges:
155 verify(_node, true);
156 }
158 void DUIterator::reset(const DUIterator& that) {
159 if (this == &that) return; // self assignment is always a no-op
160 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
161 assert(that._idx == 0, "assign only the result of Node::outs()");
162 assert(_idx == that._idx, "already assigned _idx");
163 if (!_vdui) {
164 // We need to initialize everything, overwriting garbage values.
165 sample(that._node);
166 } else {
167 DUIterator_Common::reset(that);
168 if (_refresh_tick & 1) {
169 _refresh_tick++; // Clear the "was refreshed" flag.
170 }
171 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
172 }
173 }
175 void DUIterator::refresh() {
176 DUIterator_Common::sample(_node); // Re-fetch assertion data.
177 _refresh_tick |= 1; // Set the "was refreshed" flag.
178 }
180 void DUIterator::verify_finish() {
181 // If the loop has killed the node, do not require it to re-run.
182 if (_node->_outcnt == 0) _refresh_tick &= ~1;
183 // If this assert triggers, it means that a loop used refresh_out_pos
184 // to re-synch an iteration index, but the loop did not correctly
185 // re-run itself, using a "while (progress)" construct.
186 // This iterator enforces the rule that you must keep trying the loop
187 // until it "runs clean" without any need for refreshing.
188 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
189 }
192 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
193 DUIterator_Common::verify(node, at_end_ok);
194 Node** out = node->_out;
195 uint cnt = node->_outcnt;
196 assert(cnt == _outcnt, "no insertions allowed");
197 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
198 // This last check is carefully designed to work for NO_OUT_ARRAY.
199 }
201 void DUIterator_Fast::verify_limit() {
202 const Node* node = _node;
203 verify(node, true);
204 assert(_outp == node->_out + node->_outcnt, "limit still correct");
205 }
207 void DUIterator_Fast::verify_resync() {
208 const Node* node = _node;
209 if (_outp == node->_out + _outcnt) {
210 // Note that the limit imax, not the pointer i, gets updated with the
211 // exact count of deletions. (For the pointer it's always "--i".)
212 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
213 // This is a limit pointer, with a name like "imax".
214 // Fudge the _last field so that the common assert will be happy.
215 _last = (Node*) node->_last_del;
216 DUIterator_Common::verify_resync();
217 } else {
218 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
219 // A normal internal pointer.
220 DUIterator_Common::verify_resync();
221 // Make sure we are still in sync, possibly with no more out-edges:
222 verify(node, true);
223 }
224 }
226 void DUIterator_Fast::verify_relimit(uint n) {
227 const Node* node = _node;
228 assert((int)n > 0, "use imax -= n only with a positive count");
229 // This must be a limit pointer, with a name like "imax".
230 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
231 // The reported number of deletions must match what the node saw.
232 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
233 // Fudge the _last field so that the common assert will be happy.
234 _last = (Node*) node->_last_del;
235 DUIterator_Common::verify_resync();
236 }
238 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
239 assert(_outp == that._outp, "already assigned _outp");
240 DUIterator_Common::reset(that);
241 }
243 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
244 // at_end_ok means the _outp is allowed to underflow by 1
245 _outp += at_end_ok;
246 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
247 _outp -= at_end_ok;
248 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
249 }
251 void DUIterator_Last::verify_limit() {
252 // Do not require the limit address to be resynched.
253 //verify(node, true);
254 assert(_outp == _node->_out, "limit still correct");
255 }
257 void DUIterator_Last::verify_step(uint num_edges) {
258 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
259 _outcnt -= num_edges;
260 _del_tick += num_edges;
261 // Make sure we are still in sync, possibly with no more out-edges:
262 const Node* node = _node;
263 verify(node, true);
264 assert(node->_last_del == _last, "must have deleted the edge just produced");
265 }
267 #endif //OPTO_DU_ITERATOR_ASSERT
270 #endif //ASSERT
273 // This constant used to initialize _out may be any non-null value.
274 // The value NULL is reserved for the top node only.
275 #define NO_OUT_ARRAY ((Node**)-1)
277 // This funny expression handshakes with Node::operator new
278 // to pull Compile::current out of the new node's _out field,
279 // and then calls a subroutine which manages most field
280 // initializations. The only one which is tricky is the
281 // _idx field, which is const, and so must be initialized
282 // by a return value, not an assignment.
283 //
284 // (Aren't you thankful that Java finals don't require so many tricks?)
285 #define IDX_INIT(req) this->Init((req), (Compile*) this->_out)
286 #ifdef _MSC_VER // the IDX_INIT hack falls foul of warning C4355
287 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
288 #endif
290 // Out-of-line code from node constructors.
291 // Executed only when extra debug info. is being passed around.
292 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
293 C->set_node_notes_at(idx, nn);
294 }
296 // Shared initialization code.
297 inline int Node::Init(int req, Compile* C) {
298 assert(Compile::current() == C, "must use operator new(Compile*)");
299 int idx = C->next_unique();
301 // Allocate memory for the necessary number of edges.
302 if (req > 0) {
303 // Allocate space for _in array to have double alignment.
304 _in = (Node **) ((char *) (C->node_arena()->Amalloc_D(req * sizeof(void*))));
305 #ifdef ASSERT
306 _in[req-1] = this; // magic cookie for assertion check
307 #endif
308 }
309 // If there are default notes floating around, capture them:
310 Node_Notes* nn = C->default_node_notes();
311 if (nn != NULL) init_node_notes(C, idx, nn);
313 // Note: At this point, C is dead,
314 // and we begin to initialize the new Node.
316 _cnt = _max = req;
317 _outcnt = _outmax = 0;
318 _class_id = Class_Node;
319 _flags = 0;
320 _out = NO_OUT_ARRAY;
321 return idx;
322 }
324 //------------------------------Node-------------------------------------------
325 // Create a Node, with a given number of required edges.
326 Node::Node(uint req)
327 : _idx(IDX_INIT(req))
328 {
329 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
330 debug_only( verify_construction() );
331 NOT_PRODUCT(nodes_created++);
332 if (req == 0) {
333 assert( _in == (Node**)this, "Must not pass arg count to 'new'" );
334 _in = NULL;
335 } else {
336 assert( _in[req-1] == this, "Must pass arg count to 'new'" );
337 Node** to = _in;
338 for(uint i = 0; i < req; i++) {
339 to[i] = NULL;
340 }
341 }
342 }
344 //------------------------------Node-------------------------------------------
345 Node::Node(Node *n0)
346 : _idx(IDX_INIT(1))
347 {
348 debug_only( verify_construction() );
349 NOT_PRODUCT(nodes_created++);
350 // Assert we allocated space for input array already
351 assert( _in[0] == this, "Must pass arg count to 'new'" );
352 assert( is_not_dead(n0), "can not use dead node");
353 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
354 }
356 //------------------------------Node-------------------------------------------
357 Node::Node(Node *n0, Node *n1)
358 : _idx(IDX_INIT(2))
359 {
360 debug_only( verify_construction() );
361 NOT_PRODUCT(nodes_created++);
362 // Assert we allocated space for input array already
363 assert( _in[1] == this, "Must pass arg count to 'new'" );
364 assert( is_not_dead(n0), "can not use dead node");
365 assert( is_not_dead(n1), "can not use dead node");
366 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
367 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
368 }
370 //------------------------------Node-------------------------------------------
371 Node::Node(Node *n0, Node *n1, Node *n2)
372 : _idx(IDX_INIT(3))
373 {
374 debug_only( verify_construction() );
375 NOT_PRODUCT(nodes_created++);
376 // Assert we allocated space for input array already
377 assert( _in[2] == this, "Must pass arg count to 'new'" );
378 assert( is_not_dead(n0), "can not use dead node");
379 assert( is_not_dead(n1), "can not use dead node");
380 assert( is_not_dead(n2), "can not use dead node");
381 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
382 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
383 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
384 }
386 //------------------------------Node-------------------------------------------
387 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
388 : _idx(IDX_INIT(4))
389 {
390 debug_only( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
392 // Assert we allocated space for input array already
393 assert( _in[3] == this, "Must pass arg count to 'new'" );
394 assert( is_not_dead(n0), "can not use dead node");
395 assert( is_not_dead(n1), "can not use dead node");
396 assert( is_not_dead(n2), "can not use dead node");
397 assert( is_not_dead(n3), "can not use dead node");
398 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
399 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
400 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
401 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
402 }
404 //------------------------------Node-------------------------------------------
405 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
406 : _idx(IDX_INIT(5))
407 {
408 debug_only( verify_construction() );
409 NOT_PRODUCT(nodes_created++);
410 // Assert we allocated space for input array already
411 assert( _in[4] == this, "Must pass arg count to 'new'" );
412 assert( is_not_dead(n0), "can not use dead node");
413 assert( is_not_dead(n1), "can not use dead node");
414 assert( is_not_dead(n2), "can not use dead node");
415 assert( is_not_dead(n3), "can not use dead node");
416 assert( is_not_dead(n4), "can not use dead node");
417 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
418 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
419 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
420 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
421 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
422 }
424 //------------------------------Node-------------------------------------------
425 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
426 Node *n4, Node *n5)
427 : _idx(IDX_INIT(6))
428 {
429 debug_only( verify_construction() );
430 NOT_PRODUCT(nodes_created++);
431 // Assert we allocated space for input array already
432 assert( _in[5] == this, "Must pass arg count to 'new'" );
433 assert( is_not_dead(n0), "can not use dead node");
434 assert( is_not_dead(n1), "can not use dead node");
435 assert( is_not_dead(n2), "can not use dead node");
436 assert( is_not_dead(n3), "can not use dead node");
437 assert( is_not_dead(n4), "can not use dead node");
438 assert( is_not_dead(n5), "can not use dead node");
439 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
444 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
445 }
447 //------------------------------Node-------------------------------------------
448 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
449 Node *n4, Node *n5, Node *n6)
450 : _idx(IDX_INIT(7))
451 {
452 debug_only( verify_construction() );
453 NOT_PRODUCT(nodes_created++);
454 // Assert we allocated space for input array already
455 assert( _in[6] == this, "Must pass arg count to 'new'" );
456 assert( is_not_dead(n0), "can not use dead node");
457 assert( is_not_dead(n1), "can not use dead node");
458 assert( is_not_dead(n2), "can not use dead node");
459 assert( is_not_dead(n3), "can not use dead node");
460 assert( is_not_dead(n4), "can not use dead node");
461 assert( is_not_dead(n5), "can not use dead node");
462 assert( is_not_dead(n6), "can not use dead node");
463 _in[0] = n0; if (n0 != NULL) n0->add_out((Node *)this);
464 _in[1] = n1; if (n1 != NULL) n1->add_out((Node *)this);
465 _in[2] = n2; if (n2 != NULL) n2->add_out((Node *)this);
466 _in[3] = n3; if (n3 != NULL) n3->add_out((Node *)this);
467 _in[4] = n4; if (n4 != NULL) n4->add_out((Node *)this);
468 _in[5] = n5; if (n5 != NULL) n5->add_out((Node *)this);
469 _in[6] = n6; if (n6 != NULL) n6->add_out((Node *)this);
470 }
473 //------------------------------clone------------------------------------------
474 // Clone a Node.
475 Node *Node::clone() const {
476 Compile* C = Compile::current();
477 uint s = size_of(); // Size of inherited Node
478 Node *n = (Node*)C->node_arena()->Amalloc_D(size_of() + _max*sizeof(Node*));
479 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
480 // Set the new input pointer array
481 n->_in = (Node**)(((char*)n)+s);
482 // Cannot share the old output pointer array, so kill it
483 n->_out = NO_OUT_ARRAY;
484 // And reset the counters to 0
485 n->_outcnt = 0;
486 n->_outmax = 0;
487 // Unlock this guy, since he is not in any hash table.
488 debug_only(n->_hash_lock = 0);
489 // Walk the old node's input list to duplicate its edges
490 uint i;
491 for( i = 0; i < len(); i++ ) {
492 Node *x = in(i);
493 n->_in[i] = x;
494 if (x != NULL) x->add_out(n);
495 }
496 if (is_macro())
497 C->add_macro_node(n);
498 if (is_expensive())
499 C->add_expensive_node(n);
500 // If the cloned node is a range check dependent CastII, add it to the list.
501 CastIINode* cast = n->isa_CastII();
502 if (cast != NULL && cast->has_range_check()) {
503 C->add_range_check_cast(cast);
504 }
506 n->set_idx(C->next_unique()); // Get new unique index as well
507 debug_only( n->verify_construction() );
508 NOT_PRODUCT(nodes_created++);
509 // Do not patch over the debug_idx of a clone, because it makes it
510 // impossible to break on the clone's moment of creation.
511 //debug_only( n->set_debug_idx( debug_idx() ) );
513 C->copy_node_notes_to(n, (Node*) this);
515 // MachNode clone
516 uint nopnds;
517 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
518 MachNode *mach = n->as_Mach();
519 MachNode *mthis = this->as_Mach();
520 // Get address of _opnd_array.
521 // It should be the same offset since it is the clone of this node.
522 MachOper **from = mthis->_opnds;
523 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
524 pointer_delta((const void*)from,
525 (const void*)(&mthis->_opnds), 1));
526 mach->_opnds = to;
527 for ( uint i = 0; i < nopnds; ++i ) {
528 to[i] = from[i]->clone(C);
529 }
530 }
531 // cloning CallNode may need to clone JVMState
532 if (n->is_Call()) {
533 n->as_Call()->clone_jvms(C);
534 }
535 if (n->is_SafePoint()) {
536 n->as_SafePoint()->clone_replaced_nodes();
537 }
538 return n; // Return the clone
539 }
541 //---------------------------setup_is_top--------------------------------------
542 // Call this when changing the top node, to reassert the invariants
543 // required by Node::is_top. See Compile::set_cached_top_node.
544 void Node::setup_is_top() {
545 if (this == (Node*)Compile::current()->top()) {
546 // This node has just become top. Kill its out array.
547 _outcnt = _outmax = 0;
548 _out = NULL; // marker value for top
549 assert(is_top(), "must be top");
550 } else {
551 if (_out == NULL) _out = NO_OUT_ARRAY;
552 assert(!is_top(), "must not be top");
553 }
554 }
557 //------------------------------~Node------------------------------------------
558 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
559 extern int reclaim_idx ;
560 extern int reclaim_in ;
561 extern int reclaim_node;
562 void Node::destruct() {
563 // Eagerly reclaim unique Node numberings
564 Compile* compile = Compile::current();
565 if ((uint)_idx+1 == compile->unique()) {
566 compile->set_unique(compile->unique()-1);
567 #ifdef ASSERT
568 reclaim_idx++;
569 #endif
570 }
571 // Clear debug info:
572 Node_Notes* nn = compile->node_notes_at(_idx);
573 if (nn != NULL) nn->clear();
574 // Walk the input array, freeing the corresponding output edges
575 _cnt = _max; // forget req/prec distinction
576 uint i;
577 for( i = 0; i < _max; i++ ) {
578 set_req(i, NULL);
579 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
580 }
581 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
582 // See if the input array was allocated just prior to the object
583 int edge_size = _max*sizeof(void*);
584 int out_edge_size = _outmax*sizeof(void*);
585 char *edge_end = ((char*)_in) + edge_size;
586 char *out_array = (char*)(_out == NO_OUT_ARRAY? NULL: _out);
587 char *out_edge_end = out_array + out_edge_size;
588 int node_size = size_of();
590 // Free the output edge array
591 if (out_edge_size > 0) {
592 #ifdef ASSERT
593 if( out_edge_end == compile->node_arena()->hwm() )
594 reclaim_in += out_edge_size; // count reclaimed out edges with in edges
595 #endif
596 compile->node_arena()->Afree(out_array, out_edge_size);
597 }
599 // Free the input edge array and the node itself
600 if( edge_end == (char*)this ) {
601 #ifdef ASSERT
602 if( edge_end+node_size == compile->node_arena()->hwm() ) {
603 reclaim_in += edge_size;
604 reclaim_node+= node_size;
605 }
606 #else
607 // It was; free the input array and object all in one hit
608 compile->node_arena()->Afree(_in,edge_size+node_size);
609 #endif
610 } else {
612 // Free just the input array
613 #ifdef ASSERT
614 if( edge_end == compile->node_arena()->hwm() )
615 reclaim_in += edge_size;
616 #endif
617 compile->node_arena()->Afree(_in,edge_size);
619 // Free just the object
620 #ifdef ASSERT
621 if( ((char*)this) + node_size == compile->node_arena()->hwm() )
622 reclaim_node+= node_size;
623 #else
624 compile->node_arena()->Afree(this,node_size);
625 #endif
626 }
627 if (is_macro()) {
628 compile->remove_macro_node(this);
629 }
630 if (is_expensive()) {
631 compile->remove_expensive_node(this);
632 }
633 CastIINode* cast = isa_CastII();
634 if (cast != NULL && cast->has_range_check()) {
635 compile->remove_range_check_cast(cast);
636 }
638 if (is_SafePoint()) {
639 as_SafePoint()->delete_replaced_nodes();
640 }
641 #ifdef ASSERT
642 // We will not actually delete the storage, but we'll make the node unusable.
643 *(address*)this = badAddress; // smash the C++ vtbl, probably
644 _in = _out = (Node**) badAddress;
645 _max = _cnt = _outmax = _outcnt = 0;
646 #endif
647 }
649 //------------------------------grow-------------------------------------------
650 // Grow the input array, making space for more edges
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 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
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 }
676 //-----------------------------out_grow----------------------------------------
677 // Grow the input array, making space for more edges
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 while( new_max <= len ) new_max <<= 1; // Find next power-of-2
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 }
700 #ifdef ASSERT
701 //------------------------------is_dead----------------------------------------
702 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 #endif
715 //------------------------------is_unreachable---------------------------------
716 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
717 assert(!is_Mach(), "doesn't work with MachNodes");
718 return outcnt() == 0 || igvn.type(this) == Type::TOP || in(0)->is_top();
719 }
721 //------------------------------add_req----------------------------------------
722 // Add a new required input at the end
723 void Node::add_req( Node *n ) {
724 assert( is_not_dead(n), "can not use dead node");
726 // Look to see if I can move precedence down one without reallocating
727 if( (_cnt >= _max) || (in(_max-1) != NULL) )
728 grow( _max+1 );
730 // Find a precedence edge to move
731 if( in(_cnt) != NULL ) { // Next precedence edge is busy?
732 uint i;
733 for( i=_cnt; i<_max; i++ )
734 if( in(i) == NULL ) // Find the NULL at end of prec edge list
735 break; // There must be one, since we grew the array
736 _in[i] = in(_cnt); // Move prec over, making space for req edge
737 }
738 _in[_cnt++] = n; // Stuff over old prec edge
739 if (n != NULL) n->add_out((Node *)this);
740 }
742 //---------------------------add_req_batch-------------------------------------
743 // Add a new required input at the end
744 void Node::add_req_batch( Node *n, uint m ) {
745 assert( is_not_dead(n), "can not use dead node");
746 // check various edge cases
747 if ((int)m <= 1) {
748 assert((int)m >= 0, "oob");
749 if (m != 0) add_req(n);
750 return;
751 }
753 // Look to see if I can move precedence down one without reallocating
754 if( (_cnt+m) > _max || _in[_max-m] )
755 grow( _max+m );
757 // Find a precedence edge to move
758 if( _in[_cnt] != NULL ) { // Next precedence edge is busy?
759 uint i;
760 for( i=_cnt; i<_max; i++ )
761 if( _in[i] == NULL ) // Find the NULL at end of prec edge list
762 break; // There must be one, since we grew the array
763 // Slide all the precs over by m positions (assume #prec << m).
764 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
765 }
767 // Stuff over the old prec edges
768 for(uint i=0; i<m; i++ ) {
769 _in[_cnt++] = n;
770 }
772 // Insert multiple out edges on the node.
773 if (n != NULL && !n->is_top()) {
774 for(uint i=0; i<m; i++ ) {
775 n->add_out((Node *)this);
776 }
777 }
778 }
780 //------------------------------del_req----------------------------------------
781 // Delete the required edge and compact the edge array
782 void Node::del_req( uint idx ) {
783 assert( idx < _cnt, "oob");
784 assert( !VerifyHashTableKeys || _hash_lock == 0,
785 "remove node from hash table before modifying it");
786 // First remove corresponding def-use edge
787 Node *n = in(idx);
788 if (n != NULL) n->del_out((Node *)this);
789 _in[idx] = in(--_cnt); // Compact the array
790 _in[_cnt] = NULL; // NULL out emptied slot
791 }
793 //------------------------------del_req_ordered--------------------------------
794 // Delete the required edge and compact the edge array with preserved order
795 void Node::del_req_ordered( uint idx ) {
796 assert( idx < _cnt, "oob");
797 assert( !VerifyHashTableKeys || _hash_lock == 0,
798 "remove node from hash table before modifying it");
799 // First remove corresponding def-use edge
800 Node *n = in(idx);
801 if (n != NULL) n->del_out((Node *)this);
802 if (idx < _cnt - 1) { // Not last edge ?
803 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx-1)*sizeof(Node*)));
804 }
805 _in[--_cnt] = NULL; // NULL out emptied slot
806 }
808 //------------------------------ins_req----------------------------------------
809 // Insert a new required input at the end
810 void Node::ins_req( uint idx, Node *n ) {
811 assert( is_not_dead(n), "can not use dead node");
812 add_req(NULL); // Make space
813 assert( idx < _max, "Must have allocated enough space");
814 // Slide over
815 if(_cnt-idx-1 > 0) {
816 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
817 }
818 _in[idx] = n; // Stuff over old required edge
819 if (n != NULL) n->add_out((Node *)this); // Add reciprocal def-use edge
820 }
822 //-----------------------------find_edge---------------------------------------
823 int Node::find_edge(Node* n) {
824 for (uint i = 0; i < len(); i++) {
825 if (_in[i] == n) return i;
826 }
827 return -1;
828 }
830 //----------------------------replace_edge-------------------------------------
831 int Node::replace_edge(Node* old, Node* neww) {
832 if (old == neww) return 0; // nothing to do
833 uint nrep = 0;
834 for (uint i = 0; i < len(); i++) {
835 if (in(i) == old) {
836 if (i < req())
837 set_req(i, neww);
838 else
839 set_prec(i, neww);
840 nrep++;
841 }
842 }
843 return nrep;
844 }
846 /**
847 * Replace input edges in the range pointing to 'old' node.
848 */
849 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end) {
850 if (old == neww) return 0; // nothing to do
851 uint nrep = 0;
852 for (int i = start; i < end; i++) {
853 if (in(i) == old) {
854 set_req(i, neww);
855 nrep++;
856 }
857 }
858 return nrep;
859 }
861 //-------------------------disconnect_inputs-----------------------------------
862 // NULL out all inputs to eliminate incoming Def-Use edges.
863 // Return the number of edges between 'n' and 'this'
864 int Node::disconnect_inputs(Node *n, Compile* C) {
865 int edges_to_n = 0;
867 uint cnt = req();
868 for( uint i = 0; i < cnt; ++i ) {
869 if( in(i) == 0 ) continue;
870 if( in(i) == n ) ++edges_to_n;
871 set_req(i, NULL);
872 }
873 // Remove precedence edges if any exist
874 // Note: Safepoints may have precedence edges, even during parsing
875 if( (req() != len()) && (in(req()) != NULL) ) {
876 uint max = len();
877 for( uint i = 0; i < max; ++i ) {
878 if( in(i) == 0 ) continue;
879 if( in(i) == n ) ++edges_to_n;
880 set_prec(i, NULL);
881 }
882 }
884 // Node::destruct requires all out edges be deleted first
885 // debug_only(destruct();) // no reuse benefit expected
886 if (edges_to_n == 0) {
887 C->record_dead_node(_idx);
888 }
889 return edges_to_n;
890 }
892 //-----------------------------uncast---------------------------------------
893 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
894 // Strip away casting. (It is depth-limited.)
895 Node* Node::uncast() const {
896 // Should be inline:
897 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
898 if (is_ConstraintCast() || is_CheckCastPP())
899 return uncast_helper(this);
900 else
901 return (Node*) this;
902 }
904 //---------------------------uncast_helper-------------------------------------
905 Node* Node::uncast_helper(const Node* p) {
906 #ifdef ASSERT
907 uint depth_count = 0;
908 const Node* orig_p = p;
909 #endif
911 while (true) {
912 #ifdef ASSERT
913 if (depth_count >= K) {
914 orig_p->dump(4);
915 if (p != orig_p)
916 p->dump(1);
917 }
918 assert(depth_count++ < K, "infinite loop in Node::uncast_helper");
919 #endif
920 if (p == NULL || p->req() != 2) {
921 break;
922 } else if (p->is_ConstraintCast()) {
923 p = p->in(1);
924 } else if (p->is_CheckCastPP()) {
925 p = p->in(1);
926 } else {
927 break;
928 }
929 }
930 return (Node*) p;
931 }
933 //------------------------------add_prec---------------------------------------
934 // Add a new precedence input. Precedence inputs are unordered, with
935 // duplicates removed and NULLs packed down at the end.
936 void Node::add_prec( Node *n ) {
937 assert( is_not_dead(n), "can not use dead node");
939 // Check for NULL at end
940 if( _cnt >= _max || in(_max-1) )
941 grow( _max+1 );
943 // Find a precedence edge to move
944 uint i = _cnt;
945 while( in(i) != NULL ) i++;
946 _in[i] = n; // Stuff prec edge over NULL
947 if ( n != NULL) n->add_out((Node *)this); // Add mirror edge
948 }
950 //------------------------------rm_prec----------------------------------------
951 // Remove a precedence input. Precedence inputs are unordered, with
952 // duplicates removed and NULLs packed down at the end.
953 void Node::rm_prec( uint j ) {
955 // Find end of precedence list to pack NULLs
956 uint i;
957 for( i=j; i<_max; i++ )
958 if( !_in[i] ) // Find the NULL at end of prec edge list
959 break;
960 if (_in[j] != NULL) _in[j]->del_out((Node *)this);
961 _in[j] = _in[--i]; // Move last element over removed guy
962 _in[i] = NULL; // NULL out last element
963 }
965 //------------------------------size_of----------------------------------------
966 uint Node::size_of() const { return sizeof(*this); }
968 //------------------------------ideal_reg--------------------------------------
969 uint Node::ideal_reg() const { return 0; }
971 //------------------------------jvms-------------------------------------------
972 JVMState* Node::jvms() const { return NULL; }
974 #ifdef ASSERT
975 //------------------------------jvms-------------------------------------------
976 bool Node::verify_jvms(const JVMState* using_jvms) const {
977 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
978 if (jvms == using_jvms) return true;
979 }
980 return false;
981 }
983 //------------------------------init_NodeProperty------------------------------
984 void Node::init_NodeProperty() {
985 assert(_max_classes <= max_jushort, "too many NodeProperty classes");
986 assert(_max_flags <= max_jushort, "too many NodeProperty flags");
987 }
988 #endif
990 //------------------------------format-----------------------------------------
991 // Print as assembly
992 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
993 //------------------------------emit-------------------------------------------
994 // Emit bytes starting at parameter 'ptr'.
995 void Node::emit(CodeBuffer &cbuf, PhaseRegAlloc *ra_) const {}
996 //------------------------------size-------------------------------------------
997 // Size of instruction in bytes
998 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1000 //------------------------------CFG Construction-------------------------------
1001 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1002 // Goto and Return.
1003 const Node *Node::is_block_proj() const { return 0; }
1005 // Minimum guaranteed type
1006 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1009 //------------------------------raise_bottom_type------------------------------
1010 // Get the worst-case Type output for this Node.
1011 void Node::raise_bottom_type(const Type* new_type) {
1012 if (is_Type()) {
1013 TypeNode *n = this->as_Type();
1014 if (VerifyAliases) {
1015 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1016 }
1017 n->set_type(new_type);
1018 } else if (is_Load()) {
1019 LoadNode *n = this->as_Load();
1020 if (VerifyAliases) {
1021 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1022 }
1023 n->set_type(new_type);
1024 }
1025 }
1027 //------------------------------Identity---------------------------------------
1028 // Return a node that the given node is equivalent to.
1029 Node *Node::Identity( PhaseTransform * ) {
1030 return this; // Default to no identities
1031 }
1033 //------------------------------Value------------------------------------------
1034 // Compute a new Type for a node using the Type of the inputs.
1035 const Type *Node::Value( PhaseTransform * ) const {
1036 return bottom_type(); // Default to worst-case Type
1037 }
1039 //------------------------------Ideal------------------------------------------
1040 //
1041 // 'Idealize' the graph rooted at this Node.
1042 //
1043 // In order to be efficient and flexible there are some subtle invariants
1044 // these Ideal calls need to hold. Running with '+VerifyIterativeGVN' checks
1045 // these invariants, although its too slow to have on by default. If you are
1046 // hacking an Ideal call, be sure to test with +VerifyIterativeGVN!
1047 //
1048 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1049 // pointer. If ANY change is made, it must return the root of the reshaped
1050 // graph - even if the root is the same Node. Example: swapping the inputs
1051 // to an AddINode gives the same answer and same root, but you still have to
1052 // return the 'this' pointer instead of NULL.
1053 //
1054 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1055 // Identity call to return an old Node; basically if Identity can find
1056 // another Node have the Ideal call make no change and return NULL.
1057 // Example: AddINode::Ideal must check for add of zero; in this case it
1058 // returns NULL instead of doing any graph reshaping.
1059 //
1060 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1061 // sharing there may be other users of the old Nodes relying on their current
1062 // semantics. Modifying them will break the other users.
1063 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1064 // "X+3" unchanged in case it is shared.
1065 //
1066 // If you modify the 'this' pointer's inputs, you should use
1067 // 'set_req'. If you are making a new Node (either as the new root or
1068 // some new internal piece) you may use 'init_req' to set the initial
1069 // value. You can make a new Node with either 'new' or 'clone'. In
1070 // either case, def-use info is correctly maintained.
1071 //
1072 // Example: reshape "(X+3)+4" into "X+7":
1073 // set_req(1, in(1)->in(1));
1074 // set_req(2, phase->intcon(7));
1075 // return this;
1076 // Example: reshape "X*4" into "X<<2"
1077 // return new (C) LShiftINode(in(1), phase->intcon(2));
1078 //
1079 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1080 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1081 // Node *shift=phase->transform(new(C)LShiftINode(in(1),phase->intcon(5)));
1082 // return new (C) AddINode(shift, in(1));
1083 //
1084 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1085 // These forms are faster than 'phase->transform(new (C) ConNode())' and Do
1086 // The Right Thing with def-use info.
1087 //
1088 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1089 // graph uses the 'this' Node it must be the root. If you want a Node with
1090 // the same Opcode as the 'this' pointer use 'clone'.
1091 //
1092 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1093 return NULL; // Default to being Ideal already
1094 }
1096 // Some nodes have specific Ideal subgraph transformations only if they are
1097 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1098 // for the transformations to happen.
1099 bool Node::has_special_unique_user() const {
1100 assert(outcnt() == 1, "match only for unique out");
1101 Node* n = unique_out();
1102 int op = Opcode();
1103 if( this->is_Store() ) {
1104 // Condition for back-to-back stores folding.
1105 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1106 } else if (this->is_Load()) {
1107 // Condition for removing an unused LoadNode from the MemBarAcquire precedence input
1108 return n->Opcode() == Op_MemBarAcquire;
1109 } else if( op == Op_AddL ) {
1110 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1111 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1112 } else if( op == Op_SubI || op == Op_SubL ) {
1113 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1114 return n->Opcode() == op && n->in(2) == this;
1115 }
1116 return false;
1117 };
1119 //--------------------------find_exact_control---------------------------------
1120 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1121 Node* Node::find_exact_control(Node* ctrl) {
1122 if (ctrl == NULL && this->is_Region())
1123 ctrl = this->as_Region()->is_copy();
1125 if (ctrl != NULL && ctrl->is_CatchProj()) {
1126 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1127 ctrl = ctrl->in(0);
1128 if (ctrl != NULL && !ctrl->is_top())
1129 ctrl = ctrl->in(0);
1130 }
1132 if (ctrl != NULL && ctrl->is_Proj())
1133 ctrl = ctrl->in(0);
1135 return ctrl;
1136 }
1138 //--------------------------dominates------------------------------------------
1139 // Helper function for MemNode::all_controls_dominate().
1140 // Check if 'this' control node dominates or equal to 'sub' control node.
1141 // We already know that if any path back to Root or Start reaches 'this',
1142 // then all paths so, so this is a simple search for one example,
1143 // not an exhaustive search for a counterexample.
1144 bool Node::dominates(Node* sub, Node_List &nlist) {
1145 assert(this->is_CFG(), "expecting control");
1146 assert(sub != NULL && sub->is_CFG(), "expecting control");
1148 // detect dead cycle without regions
1149 int iterations_without_region_limit = DominatorSearchLimit;
1151 Node* orig_sub = sub;
1152 Node* dom = this;
1153 bool met_dom = false;
1154 nlist.clear();
1156 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1157 // After seeing 'dom', continue up to Root or Start.
1158 // If we hit a region (backward split point), it may be a loop head.
1159 // Keep going through one of the region's inputs. If we reach the
1160 // same region again, go through a different input. Eventually we
1161 // will either exit through the loop head, or give up.
1162 // (If we get confused, break out and return a conservative 'false'.)
1163 while (sub != NULL) {
1164 if (sub->is_top()) break; // Conservative answer for dead code.
1165 if (sub == dom) {
1166 if (nlist.size() == 0) {
1167 // No Region nodes except loops were visited before and the EntryControl
1168 // path was taken for loops: it did not walk in a cycle.
1169 return true;
1170 } else if (met_dom) {
1171 break; // already met before: walk in a cycle
1172 } else {
1173 // Region nodes were visited. Continue walk up to Start or Root
1174 // to make sure that it did not walk in a cycle.
1175 met_dom = true; // first time meet
1176 iterations_without_region_limit = DominatorSearchLimit; // Reset
1177 }
1178 }
1179 if (sub->is_Start() || sub->is_Root()) {
1180 // Success if we met 'dom' along a path to Start or Root.
1181 // We assume there are no alternative paths that avoid 'dom'.
1182 // (This assumption is up to the caller to ensure!)
1183 return met_dom;
1184 }
1185 Node* up = sub->in(0);
1186 // Normalize simple pass-through regions and projections:
1187 up = sub->find_exact_control(up);
1188 // If sub == up, we found a self-loop. Try to push past it.
1189 if (sub == up && sub->is_Loop()) {
1190 // Take loop entry path on the way up to 'dom'.
1191 up = sub->in(1); // in(LoopNode::EntryControl);
1192 } else if (sub == up && sub->is_Region() && sub->req() != 3) {
1193 // Always take in(1) path on the way up to 'dom' for clone regions
1194 // (with only one input) or regions which merge > 2 paths
1195 // (usually used to merge fast/slow paths).
1196 up = sub->in(1);
1197 } else if (sub == up && sub->is_Region()) {
1198 // Try both paths for Regions with 2 input paths (it may be a loop head).
1199 // It could give conservative 'false' answer without information
1200 // which region's input is the entry path.
1201 iterations_without_region_limit = DominatorSearchLimit; // Reset
1203 bool region_was_visited_before = false;
1204 // Was this Region node visited before?
1205 // If so, we have reached it because we accidentally took a
1206 // loop-back edge from 'sub' back into the body of the loop,
1207 // and worked our way up again to the loop header 'sub'.
1208 // So, take the first unexplored path on the way up to 'dom'.
1209 for (int j = nlist.size() - 1; j >= 0; j--) {
1210 intptr_t ni = (intptr_t)nlist.at(j);
1211 Node* visited = (Node*)(ni & ~1);
1212 bool visited_twice_already = ((ni & 1) != 0);
1213 if (visited == sub) {
1214 if (visited_twice_already) {
1215 // Visited 2 paths, but still stuck in loop body. Give up.
1216 return false;
1217 }
1218 // The Region node was visited before only once.
1219 // (We will repush with the low bit set, below.)
1220 nlist.remove(j);
1221 // We will find a new edge and re-insert.
1222 region_was_visited_before = true;
1223 break;
1224 }
1225 }
1227 // Find an incoming edge which has not been seen yet; walk through it.
1228 assert(up == sub, "");
1229 uint skip = region_was_visited_before ? 1 : 0;
1230 for (uint i = 1; i < sub->req(); i++) {
1231 Node* in = sub->in(i);
1232 if (in != NULL && !in->is_top() && in != sub) {
1233 if (skip == 0) {
1234 up = in;
1235 break;
1236 }
1237 --skip; // skip this nontrivial input
1238 }
1239 }
1241 // Set 0 bit to indicate that both paths were taken.
1242 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1243 }
1245 if (up == sub) {
1246 break; // some kind of tight cycle
1247 }
1248 if (up == orig_sub && met_dom) {
1249 // returned back after visiting 'dom'
1250 break; // some kind of cycle
1251 }
1252 if (--iterations_without_region_limit < 0) {
1253 break; // dead cycle
1254 }
1255 sub = up;
1256 }
1258 // Did not meet Root or Start node in pred. chain.
1259 // Conservative answer for dead code.
1260 return false;
1261 }
1263 //------------------------------remove_dead_region-----------------------------
1264 // This control node is dead. Follow the subgraph below it making everything
1265 // using it dead as well. This will happen normally via the usual IterGVN
1266 // worklist but this call is more efficient. Do not update use-def info
1267 // inside the dead region, just at the borders.
1268 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1269 // Con's are a popular node to re-hit in the hash table again.
1270 if( dead->is_Con() ) return;
1272 // Can't put ResourceMark here since igvn->_worklist uses the same arena
1273 // for verify pass with +VerifyOpto and we add/remove elements in it here.
1274 Node_List nstack(Thread::current()->resource_area());
1276 Node *top = igvn->C->top();
1277 nstack.push(dead);
1278 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1280 while (nstack.size() > 0) {
1281 dead = nstack.pop();
1282 if (dead->outcnt() > 0) {
1283 // Keep dead node on stack until all uses are processed.
1284 nstack.push(dead);
1285 // For all Users of the Dead... ;-)
1286 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1287 Node* use = dead->last_out(k);
1288 igvn->hash_delete(use); // Yank from hash table prior to mod
1289 if (use->in(0) == dead) { // Found another dead node
1290 assert (!use->is_Con(), "Control for Con node should be Root node.");
1291 use->set_req(0, top); // Cut dead edge to prevent processing
1292 nstack.push(use); // the dead node again.
1293 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1294 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1295 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1296 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1297 use->set_req(0, top); // Cut self edge
1298 nstack.push(use);
1299 } else { // Else found a not-dead user
1300 // Dead if all inputs are top or null
1301 bool dead_use = !use->is_Root(); // Keep empty graph alive
1302 for (uint j = 1; j < use->req(); j++) {
1303 Node* in = use->in(j);
1304 if (in == dead) { // Turn all dead inputs into TOP
1305 use->set_req(j, top);
1306 } else if (in != NULL && !in->is_top()) {
1307 dead_use = false;
1308 }
1309 }
1310 if (dead_use) {
1311 if (use->is_Region()) {
1312 use->set_req(0, top); // Cut self edge
1313 }
1314 nstack.push(use);
1315 } else {
1316 igvn->_worklist.push(use);
1317 }
1318 }
1319 // Refresh the iterator, since any number of kills might have happened.
1320 k = dead->last_outs(kmin);
1321 }
1322 } else { // (dead->outcnt() == 0)
1323 // Done with outputs.
1324 igvn->hash_delete(dead);
1325 igvn->_worklist.remove(dead);
1326 igvn->set_type(dead, Type::TOP);
1327 if (dead->is_macro()) {
1328 igvn->C->remove_macro_node(dead);
1329 }
1330 if (dead->is_expensive()) {
1331 igvn->C->remove_expensive_node(dead);
1332 }
1333 CastIINode* cast = dead->isa_CastII();
1334 if (cast != NULL && cast->has_range_check()) {
1335 igvn->C->remove_range_check_cast(cast);
1336 }
1337 igvn->C->record_dead_node(dead->_idx);
1338 // Kill all inputs to the dead guy
1339 for (uint i=0; i < dead->req(); i++) {
1340 Node *n = dead->in(i); // Get input to dead guy
1341 if (n != NULL && !n->is_top()) { // Input is valid?
1342 dead->set_req(i, top); // Smash input away
1343 if (n->outcnt() == 0) { // Input also goes dead?
1344 if (!n->is_Con())
1345 nstack.push(n); // Clear it out as well
1346 } else if (n->outcnt() == 1 &&
1347 n->has_special_unique_user()) {
1348 igvn->add_users_to_worklist( n );
1349 } else if (n->outcnt() <= 2 && n->is_Store()) {
1350 // Push store's uses on worklist to enable folding optimization for
1351 // store/store and store/load to the same address.
1352 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1353 // and remove_globally_dead_node().
1354 igvn->add_users_to_worklist( n );
1355 }
1356 }
1357 }
1358 } // (dead->outcnt() == 0)
1359 } // while (nstack.size() > 0) for outputs
1360 return;
1361 }
1363 //------------------------------remove_dead_region-----------------------------
1364 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1365 Node *n = in(0);
1366 if( !n ) return false;
1367 // Lost control into this guy? I.e., it became unreachable?
1368 // Aggressively kill all unreachable code.
1369 if (can_reshape && n->is_top()) {
1370 kill_dead_code(this, phase->is_IterGVN());
1371 return false; // Node is dead.
1372 }
1374 if( n->is_Region() && n->as_Region()->is_copy() ) {
1375 Node *m = n->nonnull_req();
1376 set_req(0, m);
1377 return true;
1378 }
1379 return false;
1380 }
1382 //------------------------------Ideal_DU_postCCP-------------------------------
1383 // Idealize graph, using DU info. Must clone result into new-space
1384 Node *Node::Ideal_DU_postCCP( PhaseCCP * ) {
1385 return NULL; // Default to no change
1386 }
1388 //------------------------------hash-------------------------------------------
1389 // Hash function over Nodes.
1390 uint Node::hash() const {
1391 uint sum = 0;
1392 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1393 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded NULLs
1394 return (sum>>2) + _cnt + Opcode();
1395 }
1397 //------------------------------cmp--------------------------------------------
1398 // Compare special parts of simple Nodes
1399 uint Node::cmp( const Node &n ) const {
1400 return 1; // Must be same
1401 }
1403 //------------------------------rematerialize-----------------------------------
1404 // Should we clone rather than spill this instruction?
1405 bool Node::rematerialize() const {
1406 if ( is_Mach() )
1407 return this->as_Mach()->rematerialize();
1408 else
1409 return (_flags & Flag_rematerialize) != 0;
1410 }
1412 //------------------------------needs_anti_dependence_check---------------------
1413 // Nodes which use memory without consuming it, hence need antidependences.
1414 bool Node::needs_anti_dependence_check() const {
1415 if( req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0 )
1416 return false;
1417 else
1418 return in(1)->bottom_type()->has_memory();
1419 }
1422 // Get an integer constant from a ConNode (or CastIINode).
1423 // Return a default value if there is no apparent constant here.
1424 const TypeInt* Node::find_int_type() const {
1425 if (this->is_Type()) {
1426 return this->as_Type()->type()->isa_int();
1427 } else if (this->is_Con()) {
1428 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1429 return this->bottom_type()->isa_int();
1430 }
1431 return NULL;
1432 }
1434 // Get a pointer constant from a ConstNode.
1435 // Returns the constant if it is a pointer ConstNode
1436 intptr_t Node::get_ptr() const {
1437 assert( Opcode() == Op_ConP, "" );
1438 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1439 }
1441 // Get a narrow oop constant from a ConNNode.
1442 intptr_t Node::get_narrowcon() const {
1443 assert( Opcode() == Op_ConN, "" );
1444 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1445 }
1447 // Get a long constant from a ConNode.
1448 // Return a default value if there is no apparent constant here.
1449 const TypeLong* Node::find_long_type() const {
1450 if (this->is_Type()) {
1451 return this->as_Type()->type()->isa_long();
1452 } else if (this->is_Con()) {
1453 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1454 return this->bottom_type()->isa_long();
1455 }
1456 return NULL;
1457 }
1460 /**
1461 * Return a ptr type for nodes which should have it.
1462 */
1463 const TypePtr* Node::get_ptr_type() const {
1464 const TypePtr* tp = this->bottom_type()->make_ptr();
1465 #ifdef ASSERT
1466 if (tp == NULL) {
1467 this->dump(1);
1468 assert((tp != NULL), "unexpected node type");
1469 }
1470 #endif
1471 return tp;
1472 }
1474 // Get a double constant from a ConstNode.
1475 // Returns the constant if it is a double ConstNode
1476 jdouble Node::getd() const {
1477 assert( Opcode() == Op_ConD, "" );
1478 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1479 }
1481 // Get a float constant from a ConstNode.
1482 // Returns the constant if it is a float ConstNode
1483 jfloat Node::getf() const {
1484 assert( Opcode() == Op_ConF, "" );
1485 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1486 }
1488 #ifndef PRODUCT
1490 //----------------------------NotANode----------------------------------------
1491 // Used in debugging code to avoid walking across dead or uninitialized edges.
1492 static inline bool NotANode(const Node* n) {
1493 if (n == NULL) return true;
1494 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
1495 if (*(address*)n == badAddress) return true; // kill by Node::destruct
1496 return false;
1497 }
1500 //------------------------------find------------------------------------------
1501 // Find a neighbor of this Node with the given _idx
1502 // If idx is negative, find its absolute value, following both _in and _out.
1503 static void find_recur(Compile* C, Node* &result, Node *n, int idx, bool only_ctrl,
1504 VectorSet* old_space, VectorSet* new_space ) {
1505 int node_idx = (idx >= 0) ? idx : -idx;
1506 if (NotANode(n)) return; // Gracefully handle NULL, -1, 0xabababab, etc.
1507 // Contained in new_space or old_space? Check old_arena first since it's mostly empty.
1508 VectorSet *v = C->old_arena()->contains(n) ? old_space : new_space;
1509 if( v->test(n->_idx) ) return;
1510 if( (int)n->_idx == node_idx
1511 debug_only(|| n->debug_idx() == node_idx) ) {
1512 if (result != NULL)
1513 tty->print("find: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1514 (uintptr_t)result, (uintptr_t)n, node_idx);
1515 result = n;
1516 }
1517 v->set(n->_idx);
1518 for( uint i=0; i<n->len(); i++ ) {
1519 if( only_ctrl && !(n->is_Region()) && (n->Opcode() != Op_Root) && (i != TypeFunc::Control) ) continue;
1520 find_recur(C, result, n->in(i), idx, only_ctrl, old_space, new_space );
1521 }
1522 // Search along forward edges also:
1523 if (idx < 0 && !only_ctrl) {
1524 for( uint j=0; j<n->outcnt(); j++ ) {
1525 find_recur(C, result, n->raw_out(j), idx, only_ctrl, old_space, new_space );
1526 }
1527 }
1528 #ifdef ASSERT
1529 // Search along debug_orig edges last, checking for cycles
1530 Node* orig = n->debug_orig();
1531 if (orig != NULL) {
1532 do {
1533 if (NotANode(orig)) break;
1534 find_recur(C, result, orig, idx, only_ctrl, old_space, new_space );
1535 orig = orig->debug_orig();
1536 } while (orig != NULL && orig != n->debug_orig());
1537 }
1538 #endif //ASSERT
1539 }
1541 // call this from debugger:
1542 Node* find_node(Node* n, int idx) {
1543 return n->find(idx);
1544 }
1546 //------------------------------find-------------------------------------------
1547 Node* Node::find(int idx) const {
1548 ResourceArea *area = Thread::current()->resource_area();
1549 VectorSet old_space(area), new_space(area);
1550 Node* result = NULL;
1551 find_recur(Compile::current(), result, (Node*) this, idx, false, &old_space, &new_space );
1552 return result;
1553 }
1555 //------------------------------find_ctrl--------------------------------------
1556 // Find an ancestor to this node in the control history with given _idx
1557 Node* Node::find_ctrl(int idx) const {
1558 ResourceArea *area = Thread::current()->resource_area();
1559 VectorSet old_space(area), new_space(area);
1560 Node* result = NULL;
1561 find_recur(Compile::current(), result, (Node*) this, idx, true, &old_space, &new_space );
1562 return result;
1563 }
1564 #endif
1568 #ifndef PRODUCT
1570 // -----------------------------Name-------------------------------------------
1571 extern const char *NodeClassNames[];
1572 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
1574 static bool is_disconnected(const Node* n) {
1575 for (uint i = 0; i < n->req(); i++) {
1576 if (n->in(i) != NULL) return false;
1577 }
1578 return true;
1579 }
1581 #ifdef ASSERT
1582 static void dump_orig(Node* orig, outputStream *st) {
1583 Compile* C = Compile::current();
1584 if (NotANode(orig)) orig = NULL;
1585 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1586 if (orig == NULL) return;
1587 st->print(" !orig=");
1588 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
1589 if (NotANode(fast)) fast = NULL;
1590 while (orig != NULL) {
1591 bool discon = is_disconnected(orig); // if discon, print [123] else 123
1592 if (discon) st->print("[");
1593 if (!Compile::current()->node_arena()->contains(orig))
1594 st->print("o");
1595 st->print("%d", orig->_idx);
1596 if (discon) st->print("]");
1597 orig = orig->debug_orig();
1598 if (NotANode(orig)) orig = NULL;
1599 if (orig != NULL && !C->node_arena()->contains(orig)) orig = NULL;
1600 if (orig != NULL) st->print(",");
1601 if (fast != NULL) {
1602 // Step fast twice for each single step of orig:
1603 fast = fast->debug_orig();
1604 if (NotANode(fast)) fast = NULL;
1605 if (fast != NULL && fast != orig) {
1606 fast = fast->debug_orig();
1607 if (NotANode(fast)) fast = NULL;
1608 }
1609 if (fast == orig) {
1610 st->print("...");
1611 break;
1612 }
1613 }
1614 }
1615 }
1617 void Node::set_debug_orig(Node* orig) {
1618 _debug_orig = orig;
1619 if (BreakAtNode == 0) return;
1620 if (NotANode(orig)) orig = NULL;
1621 int trip = 10;
1622 while (orig != NULL) {
1623 if (orig->debug_idx() == BreakAtNode || (int)orig->_idx == BreakAtNode) {
1624 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=%d orig._idx=%d orig._debug_idx=%d",
1625 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
1626 BREAKPOINT;
1627 }
1628 orig = orig->debug_orig();
1629 if (NotANode(orig)) orig = NULL;
1630 if (trip-- <= 0) break;
1631 }
1632 }
1633 #endif //ASSERT
1635 //------------------------------dump------------------------------------------
1636 // Dump a Node
1637 void Node::dump(const char* suffix, outputStream *st) const {
1638 Compile* C = Compile::current();
1639 bool is_new = C->node_arena()->contains(this);
1640 C->_in_dump_cnt++;
1641 st->print("%c%d\t%s\t=== ", is_new ? ' ' : 'o', _idx, Name());
1643 // Dump the required and precedence inputs
1644 dump_req(st);
1645 dump_prec(st);
1646 // Dump the outputs
1647 dump_out(st);
1649 if (is_disconnected(this)) {
1650 #ifdef ASSERT
1651 st->print(" [%d]",debug_idx());
1652 dump_orig(debug_orig(), st);
1653 #endif
1654 st->cr();
1655 C->_in_dump_cnt--;
1656 return; // don't process dead nodes
1657 }
1659 // Dump node-specific info
1660 dump_spec(st);
1661 #ifdef ASSERT
1662 // Dump the non-reset _debug_idx
1663 if (Verbose && WizardMode) {
1664 st->print(" [%d]",debug_idx());
1665 }
1666 #endif
1668 const Type *t = bottom_type();
1670 if (t != NULL && (t->isa_instptr() || t->isa_klassptr())) {
1671 const TypeInstPtr *toop = t->isa_instptr();
1672 const TypeKlassPtr *tkls = t->isa_klassptr();
1673 ciKlass* klass = toop ? toop->klass() : (tkls ? tkls->klass() : NULL );
1674 if (klass && klass->is_loaded() && klass->is_interface()) {
1675 st->print(" Interface:");
1676 } else if (toop) {
1677 st->print(" Oop:");
1678 } else if (tkls) {
1679 st->print(" Klass:");
1680 }
1681 t->dump_on(st);
1682 } else if (t == Type::MEMORY) {
1683 st->print(" Memory:");
1684 MemNode::dump_adr_type(this, adr_type(), st);
1685 } else if (Verbose || WizardMode) {
1686 st->print(" Type:");
1687 if (t) {
1688 t->dump_on(st);
1689 } else {
1690 st->print("no type");
1691 }
1692 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
1693 // Dump MachSpillcopy vector type.
1694 t->dump_on(st);
1695 }
1696 if (is_new) {
1697 debug_only(dump_orig(debug_orig(), st));
1698 Node_Notes* nn = C->node_notes_at(_idx);
1699 if (nn != NULL && !nn->is_clear()) {
1700 if (nn->jvms() != NULL) {
1701 st->print(" !jvms:");
1702 nn->jvms()->dump_spec(st);
1703 }
1704 }
1705 }
1706 if (suffix) st->print("%s", suffix);
1707 C->_in_dump_cnt--;
1708 }
1710 //------------------------------dump_req--------------------------------------
1711 void Node::dump_req(outputStream *st) const {
1712 // Dump the required input edges
1713 for (uint i = 0; i < req(); i++) { // For all required inputs
1714 Node* d = in(i);
1715 if (d == NULL) {
1716 st->print("_ ");
1717 } else if (NotANode(d)) {
1718 st->print("NotANode "); // uninitialized, sentinel, garbage, etc.
1719 } else {
1720 st->print("%c%d ", Compile::current()->node_arena()->contains(d) ? ' ' : 'o', d->_idx);
1721 }
1722 }
1723 }
1726 //------------------------------dump_prec-------------------------------------
1727 void Node::dump_prec(outputStream *st) const {
1728 // Dump the precedence edges
1729 int any_prec = 0;
1730 for (uint i = req(); i < len(); i++) { // For all precedence inputs
1731 Node* p = in(i);
1732 if (p != NULL) {
1733 if (!any_prec++) st->print(" |");
1734 if (NotANode(p)) { st->print("NotANode "); continue; }
1735 st->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
1736 }
1737 }
1738 }
1740 //------------------------------dump_out--------------------------------------
1741 void Node::dump_out(outputStream *st) const {
1742 // Delimit the output edges
1743 st->print(" [[");
1744 // Dump the output edges
1745 for (uint i = 0; i < _outcnt; i++) { // For all outputs
1746 Node* u = _out[i];
1747 if (u == NULL) {
1748 st->print("_ ");
1749 } else if (NotANode(u)) {
1750 st->print("NotANode ");
1751 } else {
1752 st->print("%c%d ", Compile::current()->node_arena()->contains(u) ? ' ' : 'o', u->_idx);
1753 }
1754 }
1755 st->print("]] ");
1756 }
1758 //------------------------------dump_nodes-------------------------------------
1759 static void dump_nodes(const Node* start, int d, bool only_ctrl) {
1760 Node* s = (Node*)start; // remove const
1761 if (NotANode(s)) return;
1763 uint depth = (uint)ABS(d);
1764 int direction = d;
1765 Compile* C = Compile::current();
1766 GrowableArray <Node *> nstack(C->live_nodes());
1768 nstack.append(s);
1769 int begin = 0;
1770 int end = 0;
1771 for(uint i = 0; i < depth; i++) {
1772 end = nstack.length();
1773 for(int j = begin; j < end; j++) {
1774 Node* tp = nstack.at(j);
1775 uint limit = direction > 0 ? tp->len() : tp->outcnt();
1776 for(uint k = 0; k < limit; k++) {
1777 Node* n = direction > 0 ? tp->in(k) : tp->raw_out(k);
1779 if (NotANode(n)) continue;
1780 // do not recurse through top or the root (would reach unrelated stuff)
1781 if (n->is_Root() || n->is_top()) continue;
1782 if (only_ctrl && !n->is_CFG()) continue;
1784 bool on_stack = nstack.contains(n);
1785 if (!on_stack) {
1786 nstack.append(n);
1787 }
1788 }
1789 }
1790 begin = end;
1791 }
1792 end = nstack.length();
1793 if (direction > 0) {
1794 for(int j = end-1; j >= 0; j--) {
1795 nstack.at(j)->dump();
1796 }
1797 } else {
1798 for(int j = 0; j < end; j++) {
1799 nstack.at(j)->dump();
1800 }
1801 }
1802 }
1804 //------------------------------dump-------------------------------------------
1805 void Node::dump(int d) const {
1806 dump_nodes(this, d, false);
1807 }
1809 //------------------------------dump_ctrl--------------------------------------
1810 // Dump a Node's control history to depth
1811 void Node::dump_ctrl(int d) const {
1812 dump_nodes(this, d, true);
1813 }
1815 // VERIFICATION CODE
1816 // For each input edge to a node (ie - for each Use-Def edge), verify that
1817 // there is a corresponding Def-Use edge.
1818 //------------------------------verify_edges-----------------------------------
1819 void Node::verify_edges(Unique_Node_List &visited) {
1820 uint i, j, idx;
1821 int cnt;
1822 Node *n;
1824 // Recursive termination test
1825 if (visited.member(this)) return;
1826 visited.push(this);
1828 // Walk over all input edges, checking for correspondence
1829 for( i = 0; i < len(); i++ ) {
1830 n = in(i);
1831 if (n != NULL && !n->is_top()) {
1832 // Count instances of (Node *)this
1833 cnt = 0;
1834 for (idx = 0; idx < n->_outcnt; idx++ ) {
1835 if (n->_out[idx] == (Node *)this) cnt++;
1836 }
1837 assert( cnt > 0,"Failed to find Def-Use edge." );
1838 // Check for duplicate edges
1839 // walk the input array downcounting the input edges to n
1840 for( j = 0; j < len(); j++ ) {
1841 if( in(j) == n ) cnt--;
1842 }
1843 assert( cnt == 0,"Mismatched edge count.");
1844 } else if (n == NULL) {
1845 assert(i >= req() || i == 0 || is_Region() || is_Phi(), "only regions or phis have null data edges");
1846 } else {
1847 assert(n->is_top(), "sanity");
1848 // Nothing to check.
1849 }
1850 }
1851 // Recursive walk over all input edges
1852 for( i = 0; i < len(); i++ ) {
1853 n = in(i);
1854 if( n != NULL )
1855 in(i)->verify_edges(visited);
1856 }
1857 }
1859 //------------------------------verify_recur-----------------------------------
1860 static const Node *unique_top = NULL;
1862 void Node::verify_recur(const Node *n, int verify_depth,
1863 VectorSet &old_space, VectorSet &new_space) {
1864 if ( verify_depth == 0 ) return;
1865 if (verify_depth > 0) --verify_depth;
1867 Compile* C = Compile::current();
1869 // Contained in new_space or old_space?
1870 VectorSet *v = C->node_arena()->contains(n) ? &new_space : &old_space;
1871 // Check for visited in the proper space. Numberings are not unique
1872 // across spaces so we need a separate VectorSet for each space.
1873 if( v->test_set(n->_idx) ) return;
1875 if (n->is_Con() && n->bottom_type() == Type::TOP) {
1876 if (C->cached_top_node() == NULL)
1877 C->set_cached_top_node((Node*)n);
1878 assert(C->cached_top_node() == n, "TOP node must be unique");
1879 }
1881 for( uint i = 0; i < n->len(); i++ ) {
1882 Node *x = n->in(i);
1883 if (!x || x->is_top()) continue;
1885 // Verify my input has a def-use edge to me
1886 if (true /*VerifyDefUse*/) {
1887 // Count use-def edges from n to x
1888 int cnt = 0;
1889 for( uint j = 0; j < n->len(); j++ )
1890 if( n->in(j) == x )
1891 cnt++;
1892 // Count def-use edges from x to n
1893 uint max = x->_outcnt;
1894 for( uint k = 0; k < max; k++ )
1895 if (x->_out[k] == n)
1896 cnt--;
1897 assert( cnt == 0, "mismatched def-use edge counts" );
1898 }
1900 verify_recur(x, verify_depth, old_space, new_space);
1901 }
1903 }
1905 //------------------------------verify-----------------------------------------
1906 // Check Def-Use info for my subgraph
1907 void Node::verify() const {
1908 Compile* C = Compile::current();
1909 Node* old_top = C->cached_top_node();
1910 ResourceMark rm;
1911 ResourceArea *area = Thread::current()->resource_area();
1912 VectorSet old_space(area), new_space(area);
1913 verify_recur(this, -1, old_space, new_space);
1914 C->set_cached_top_node(old_top);
1915 }
1916 #endif
1919 //------------------------------walk-------------------------------------------
1920 // Graph walk, with both pre-order and post-order functions
1921 void Node::walk(NFunc pre, NFunc post, void *env) {
1922 VectorSet visited(Thread::current()->resource_area()); // Setup for local walk
1923 walk_(pre, post, env, visited);
1924 }
1926 void Node::walk_(NFunc pre, NFunc post, void *env, VectorSet &visited) {
1927 if( visited.test_set(_idx) ) return;
1928 pre(*this,env); // Call the pre-order walk function
1929 for( uint i=0; i<_max; i++ )
1930 if( in(i) ) // Input exists and is not walked?
1931 in(i)->walk_(pre,post,env,visited); // Walk it with pre & post functions
1932 post(*this,env); // Call the post-order walk function
1933 }
1935 void Node::nop(Node &, void*) {}
1937 //------------------------------Registers--------------------------------------
1938 // Do we Match on this edge index or not? Generally false for Control
1939 // and true for everything else. Weird for calls & returns.
1940 uint Node::match_edge(uint idx) const {
1941 return idx; // True for other than index 0 (control)
1942 }
1944 static RegMask _not_used_at_all;
1945 // Register classes are defined for specific machines
1946 const RegMask &Node::out_RegMask() const {
1947 ShouldNotCallThis();
1948 return _not_used_at_all;
1949 }
1951 const RegMask &Node::in_RegMask(uint) const {
1952 ShouldNotCallThis();
1953 return _not_used_at_all;
1954 }
1956 //=============================================================================
1957 //-----------------------------------------------------------------------------
1958 void Node_Array::reset( Arena *new_arena ) {
1959 _a->Afree(_nodes,_max*sizeof(Node*));
1960 _max = 0;
1961 _nodes = NULL;
1962 _a = new_arena;
1963 }
1965 //------------------------------clear------------------------------------------
1966 // Clear all entries in _nodes to NULL but keep storage
1967 void Node_Array::clear() {
1968 Copy::zero_to_bytes( _nodes, _max*sizeof(Node*) );
1969 }
1971 //-----------------------------------------------------------------------------
1972 void Node_Array::grow( uint i ) {
1973 if( !_max ) {
1974 _max = 1;
1975 _nodes = (Node**)_a->Amalloc( _max * sizeof(Node*) );
1976 _nodes[0] = NULL;
1977 }
1978 uint old = _max;
1979 while( i >= _max ) _max <<= 1; // Double to fit
1980 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
1981 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
1982 }
1984 //-----------------------------------------------------------------------------
1985 void Node_Array::insert( uint i, Node *n ) {
1986 if( _nodes[_max-1] ) grow(_max); // Get more space if full
1987 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i+1], ((_max-i-1)*sizeof(Node*)));
1988 _nodes[i] = n;
1989 }
1991 //-----------------------------------------------------------------------------
1992 void Node_Array::remove( uint i ) {
1993 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i+1], (HeapWord*)&_nodes[i], ((_max-i-1)*sizeof(Node*)));
1994 _nodes[_max-1] = NULL;
1995 }
1997 //-----------------------------------------------------------------------------
1998 void Node_Array::sort( C_sort_func_t func) {
1999 qsort( _nodes, _max, sizeof( Node* ), func );
2000 }
2002 //-----------------------------------------------------------------------------
2003 void Node_Array::dump() const {
2004 #ifndef PRODUCT
2005 for( uint i = 0; i < _max; i++ ) {
2006 Node *nn = _nodes[i];
2007 if( nn != NULL ) {
2008 tty->print("%5d--> ",i); nn->dump();
2009 }
2010 }
2011 #endif
2012 }
2014 //--------------------------is_iteratively_computed------------------------------
2015 // Operation appears to be iteratively computed (such as an induction variable)
2016 // It is possible for this operation to return false for a loop-varying
2017 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2018 bool Node::is_iteratively_computed() {
2019 if (ideal_reg()) { // does operation have a result register?
2020 for (uint i = 1; i < req(); i++) {
2021 Node* n = in(i);
2022 if (n != NULL && n->is_Phi()) {
2023 for (uint j = 1; j < n->req(); j++) {
2024 if (n->in(j) == this) {
2025 return true;
2026 }
2027 }
2028 }
2029 }
2030 }
2031 return false;
2032 }
2034 //--------------------------find_similar------------------------------
2035 // Return a node with opcode "opc" and same inputs as "this" if one can
2036 // be found; Otherwise return NULL;
2037 Node* Node::find_similar(int opc) {
2038 if (req() >= 2) {
2039 Node* def = in(1);
2040 if (def && def->outcnt() >= 2) {
2041 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2042 Node* use = def->fast_out(i);
2043 if (use->Opcode() == opc &&
2044 use->req() == req()) {
2045 uint j;
2046 for (j = 0; j < use->req(); j++) {
2047 if (use->in(j) != in(j)) {
2048 break;
2049 }
2050 }
2051 if (j == use->req()) {
2052 return use;
2053 }
2054 }
2055 }
2056 }
2057 }
2058 return NULL;
2059 }
2062 //--------------------------unique_ctrl_out------------------------------
2063 // Return the unique control out if only one. Null if none or more than one.
2064 Node* Node::unique_ctrl_out() {
2065 Node* found = NULL;
2066 for (uint i = 0; i < outcnt(); i++) {
2067 Node* use = raw_out(i);
2068 if (use->is_CFG() && use != this) {
2069 if (found != NULL) return NULL;
2070 found = use;
2071 }
2072 }
2073 return found;
2074 }
2076 //=============================================================================
2077 //------------------------------yank-------------------------------------------
2078 // Find and remove
2079 void Node_List::yank( Node *n ) {
2080 uint i;
2081 for( i = 0; i < _cnt; i++ )
2082 if( _nodes[i] == n )
2083 break;
2085 if( i < _cnt )
2086 _nodes[i] = _nodes[--_cnt];
2087 }
2089 //------------------------------dump-------------------------------------------
2090 void Node_List::dump() const {
2091 #ifndef PRODUCT
2092 for( uint i = 0; i < _cnt; i++ )
2093 if( _nodes[i] ) {
2094 tty->print("%5d--> ",i);
2095 _nodes[i]->dump();
2096 }
2097 #endif
2098 }
2100 //=============================================================================
2101 //------------------------------remove-----------------------------------------
2102 void Unique_Node_List::remove( Node *n ) {
2103 if( _in_worklist[n->_idx] ) {
2104 for( uint i = 0; i < size(); i++ )
2105 if( _nodes[i] == n ) {
2106 map(i,Node_List::pop());
2107 _in_worklist >>= n->_idx;
2108 return;
2109 }
2110 ShouldNotReachHere();
2111 }
2112 }
2114 //-----------------------remove_useless_nodes----------------------------------
2115 // Remove useless nodes from worklist
2116 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
2118 for( uint i = 0; i < size(); ++i ) {
2119 Node *n = at(i);
2120 assert( n != NULL, "Did not expect null entries in worklist");
2121 if( ! useful.test(n->_idx) ) {
2122 _in_worklist >>= n->_idx;
2123 map(i,Node_List::pop());
2124 // Node *replacement = Node_List::pop();
2125 // if( i != size() ) { // Check if removing last entry
2126 // _nodes[i] = replacement;
2127 // }
2128 --i; // Visit popped node
2129 // If it was last entry, loop terminates since size() was also reduced
2130 }
2131 }
2132 }
2134 //=============================================================================
2135 void Node_Stack::grow() {
2136 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
2137 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
2138 size_t max = old_max << 1; // max * 2
2139 _inodes = REALLOC_ARENA_ARRAY(_a, INode, _inodes, old_max, max);
2140 _inode_max = _inodes + max;
2141 _inode_top = _inodes + old_top; // restore _top
2142 }
2144 // Node_Stack is used to map nodes.
2145 Node* Node_Stack::find(uint idx) const {
2146 uint sz = size();
2147 for (uint i=0; i < sz; i++) {
2148 if (idx == index_at(i) )
2149 return node_at(i);
2150 }
2151 return NULL;
2152 }
2154 //=============================================================================
2155 uint TypeNode::size_of() const { return sizeof(*this); }
2156 #ifndef PRODUCT
2157 void TypeNode::dump_spec(outputStream *st) const {
2158 if( !Verbose && !WizardMode ) {
2159 // standard dump does this in Verbose and WizardMode
2160 st->print(" #"); _type->dump_on(st);
2161 }
2162 }
2163 #endif
2164 uint TypeNode::hash() const {
2165 return Node::hash() + _type->hash();
2166 }
2167 uint TypeNode::cmp( const Node &n ) const
2168 { return !Type::cmp( _type, ((TypeNode&)n)._type ); }
2169 const Type *TypeNode::bottom_type() const { return _type; }
2170 const Type *TypeNode::Value( PhaseTransform * ) const { return _type; }
2172 //------------------------------ideal_reg--------------------------------------
2173 uint TypeNode::ideal_reg() const {
2174 return _type->ideal_reg();
2175 }