1 /*
2 * Copyright (c) 2005, 2009, 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 "incls/_precompiled.incl"
26 #include "incls/_escape.cpp.incl"
27
28 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
29 uint v = (targIdx << EdgeShift) + ((uint) et);
30 if (_edges == NULL) {
31 Arena *a = Compile::current()->comp_arena();
32 _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
33 }
34 _edges->append_if_missing(v);
35 }
36
37 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
38 uint v = (targIdx << EdgeShift) + ((uint) et);
39
40 _edges->remove(v);
41 }
42
43 #ifndef PRODUCT
44 static const char *node_type_names[] = {
45 "UnknownType",
46 "JavaObject",
47 "LocalVar",
48 "Field"
49 };
50
51 static const char *esc_names[] = {
52 "UnknownEscape",
53 "NoEscape",
54 "ArgEscape",
55 "GlobalEscape"
56 };
57
58 static const char *edge_type_suffix[] = {
59 "?", // UnknownEdge
60 "P", // PointsToEdge
61 "D", // DeferredEdge
62 "F" // FieldEdge
63 };
64
65 void PointsToNode::dump(bool print_state) const {
66 NodeType nt = node_type();
67 tty->print("%s ", node_type_names[(int) nt]);
68 if (print_state) {
69 EscapeState es = escape_state();
70 tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
71 }
72 tty->print("[[");
73 for (uint i = 0; i < edge_count(); i++) {
74 tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
75 }
76 tty->print("]] ");
77 if (_node == NULL)
78 tty->print_cr("<null>");
79 else
80 _node->dump();
81 }
82 #endif
83
84 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
85 _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
86 _processed(C->comp_arena()),
87 _collecting(true),
88 _compile(C),
89 _igvn(igvn),
90 _node_map(C->comp_arena()) {
91
92 _phantom_object = C->top()->_idx,
93 add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
94
95 // Add ConP(#NULL) and ConN(#NULL) nodes.
96 Node* oop_null = igvn->zerocon(T_OBJECT);
97 _oop_null = oop_null->_idx;
98 assert(_oop_null < C->unique(), "should be created already");
99 add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
100
101 if (UseCompressedOops) {
102 Node* noop_null = igvn->zerocon(T_NARROWOOP);
103 _noop_null = noop_null->_idx;
104 assert(_noop_null < C->unique(), "should be created already");
105 add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
106 }
107 }
108
109 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
110 PointsToNode *f = ptnode_adr(from_i);
111 PointsToNode *t = ptnode_adr(to_i);
112
113 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
114 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
115 assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
116 f->add_edge(to_i, PointsToNode::PointsToEdge);
117 }
118
119 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
120 PointsToNode *f = ptnode_adr(from_i);
121 PointsToNode *t = ptnode_adr(to_i);
122
123 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
124 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
125 assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
126 // don't add a self-referential edge, this can occur during removal of
127 // deferred edges
128 if (from_i != to_i)
129 f->add_edge(to_i, PointsToNode::DeferredEdge);
130 }
131
132 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
133 const Type *adr_type = phase->type(adr);
134 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
135 adr->in(AddPNode::Address)->is_Proj() &&
136 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
137 // We are computing a raw address for a store captured by an Initialize
138 // compute an appropriate address type. AddP cases #3 and #5 (see below).
139 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
140 assert(offs != Type::OffsetBot ||
141 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
142 "offset must be a constant or it is initialization of array");
143 return offs;
144 }
145 const TypePtr *t_ptr = adr_type->isa_ptr();
146 assert(t_ptr != NULL, "must be a pointer type");
147 return t_ptr->offset();
148 }
149
150 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
151 PointsToNode *f = ptnode_adr(from_i);
152 PointsToNode *t = ptnode_adr(to_i);
153
154 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
155 assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
156 assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
157 assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
158 t->set_offset(offset);
159
160 f->add_edge(to_i, PointsToNode::FieldEdge);
161 }
162
163 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
164 PointsToNode *npt = ptnode_adr(ni);
165 PointsToNode::EscapeState old_es = npt->escape_state();
166 if (es > old_es)
167 npt->set_escape_state(es);
168 }
169
170 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
171 PointsToNode::EscapeState es, bool done) {
172 PointsToNode* ptadr = ptnode_adr(n->_idx);
173 ptadr->_node = n;
174 ptadr->set_node_type(nt);
175
176 // inline set_escape_state(idx, es);
177 PointsToNode::EscapeState old_es = ptadr->escape_state();
178 if (es > old_es)
179 ptadr->set_escape_state(es);
180
181 if (done)
182 _processed.set(n->_idx);
183 }
184
185 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
186 uint idx = n->_idx;
187 PointsToNode::EscapeState es;
188
189 // If we are still collecting or there were no non-escaping allocations
190 // we don't know the answer yet
191 if (_collecting)
192 return PointsToNode::UnknownEscape;
193
194 // if the node was created after the escape computation, return
195 // UnknownEscape
196 if (idx >= nodes_size())
197 return PointsToNode::UnknownEscape;
198
199 es = ptnode_adr(idx)->escape_state();
200
201 // if we have already computed a value, return it
202 if (es != PointsToNode::UnknownEscape &&
203 ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
204 return es;
205
206 // PointsTo() calls n->uncast() which can return a new ideal node.
207 if (n->uncast()->_idx >= nodes_size())
208 return PointsToNode::UnknownEscape;
209
210 PointsToNode::EscapeState orig_es = es;
211
212 // compute max escape state of anything this node could point to
213 VectorSet ptset(Thread::current()->resource_area());
214 PointsTo(ptset, n);
215 for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
216 uint pt = i.elem;
217 PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
218 if (pes > es)
219 es = pes;
220 }
221 if (orig_es != es) {
222 // cache the computed escape state
223 assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
224 ptnode_adr(idx)->set_escape_state(es);
225 } // orig_es could be PointsToNode::UnknownEscape
226 return es;
227 }
228
229 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n) {
230 VectorSet visited(Thread::current()->resource_area());
231 GrowableArray<uint> worklist;
232
233 #ifdef ASSERT
234 Node *orig_n = n;
235 #endif
236
237 n = n->uncast();
238 PointsToNode* npt = ptnode_adr(n->_idx);
239
240 // If we have a JavaObject, return just that object
241 if (npt->node_type() == PointsToNode::JavaObject) {
242 ptset.set(n->_idx);
243 return;
244 }
245 #ifdef ASSERT
246 if (npt->_node == NULL) {
247 if (orig_n != n)
248 orig_n->dump();
249 n->dump();
250 assert(npt->_node != NULL, "unregistered node");
251 }
252 #endif
253 worklist.push(n->_idx);
254 while(worklist.length() > 0) {
255 int ni = worklist.pop();
256 if (visited.test_set(ni))
257 continue;
258
259 PointsToNode* pn = ptnode_adr(ni);
260 // ensure that all inputs of a Phi have been processed
261 assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
262
263 int edges_processed = 0;
264 uint e_cnt = pn->edge_count();
265 for (uint e = 0; e < e_cnt; e++) {
266 uint etgt = pn->edge_target(e);
267 PointsToNode::EdgeType et = pn->edge_type(e);
268 if (et == PointsToNode::PointsToEdge) {
269 ptset.set(etgt);
270 edges_processed++;
271 } else if (et == PointsToNode::DeferredEdge) {
272 worklist.push(etgt);
273 edges_processed++;
274 } else {
275 assert(false,"neither PointsToEdge or DeferredEdge");
276 }
277 }
278 if (edges_processed == 0) {
279 // no deferred or pointsto edges found. Assume the value was set
280 // outside this method. Add the phantom object to the pointsto set.
281 ptset.set(_phantom_object);
282 }
283 }
284 }
285
286 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
287 // This method is most expensive during ConnectionGraph construction.
288 // Reuse vectorSet and an additional growable array for deferred edges.
289 deferred_edges->clear();
290 visited->Clear();
291
292 visited->set(ni);
293 PointsToNode *ptn = ptnode_adr(ni);
294
295 // Mark current edges as visited and move deferred edges to separate array.
296 for (uint i = 0; i < ptn->edge_count(); ) {
297 uint t = ptn->edge_target(i);
298 #ifdef ASSERT
299 assert(!visited->test_set(t), "expecting no duplications");
300 #else
301 visited->set(t);
302 #endif
303 if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
304 ptn->remove_edge(t, PointsToNode::DeferredEdge);
305 deferred_edges->append(t);
306 } else {
307 i++;
308 }
309 }
310 for (int next = 0; next < deferred_edges->length(); ++next) {
311 uint t = deferred_edges->at(next);
312 PointsToNode *ptt = ptnode_adr(t);
313 uint e_cnt = ptt->edge_count();
314 for (uint e = 0; e < e_cnt; e++) {
315 uint etgt = ptt->edge_target(e);
316 if (visited->test_set(etgt))
317 continue;
318
319 PointsToNode::EdgeType et = ptt->edge_type(e);
320 if (et == PointsToNode::PointsToEdge) {
321 add_pointsto_edge(ni, etgt);
322 if(etgt == _phantom_object) {
323 // Special case - field set outside (globally escaping).
324 ptn->set_escape_state(PointsToNode::GlobalEscape);
325 }
326 } else if (et == PointsToNode::DeferredEdge) {
327 deferred_edges->append(etgt);
328 } else {
329 assert(false,"invalid connection graph");
330 }
331 }
332 }
333 }
334
335
336 // Add an edge to node given by "to_i" from any field of adr_i whose offset
337 // matches "offset" A deferred edge is added if to_i is a LocalVar, and
338 // a pointsto edge is added if it is a JavaObject
339
340 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
341 PointsToNode* an = ptnode_adr(adr_i);
342 PointsToNode* to = ptnode_adr(to_i);
343 bool deferred = (to->node_type() == PointsToNode::LocalVar);
344
345 for (uint fe = 0; fe < an->edge_count(); fe++) {
346 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
347 int fi = an->edge_target(fe);
348 PointsToNode* pf = ptnode_adr(fi);
349 int po = pf->offset();
350 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
351 if (deferred)
352 add_deferred_edge(fi, to_i);
353 else
354 add_pointsto_edge(fi, to_i);
355 }
356 }
357 }
358
359 // Add a deferred edge from node given by "from_i" to any field of adr_i
360 // whose offset matches "offset".
361 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
362 PointsToNode* an = ptnode_adr(adr_i);
363 for (uint fe = 0; fe < an->edge_count(); fe++) {
364 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
365 int fi = an->edge_target(fe);
366 PointsToNode* pf = ptnode_adr(fi);
367 int po = pf->offset();
368 if (pf->edge_count() == 0) {
369 // we have not seen any stores to this field, assume it was set outside this method
370 add_pointsto_edge(fi, _phantom_object);
371 }
372 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
373 add_deferred_edge(from_i, fi);
374 }
375 }
376 }
377
378 // Helper functions
379
380 static Node* get_addp_base(Node *addp) {
381 assert(addp->is_AddP(), "must be AddP");
382 //
383 // AddP cases for Base and Address inputs:
384 // case #1. Direct object's field reference:
385 // Allocate
386 // |
387 // Proj #5 ( oop result )
388 // |
389 // CheckCastPP (cast to instance type)
390 // | |
391 // AddP ( base == address )
392 //
393 // case #2. Indirect object's field reference:
394 // Phi
395 // |
396 // CastPP (cast to instance type)
397 // | |
398 // AddP ( base == address )
399 //
400 // case #3. Raw object's field reference for Initialize node:
401 // Allocate
402 // |
403 // Proj #5 ( oop result )
404 // top |
405 // \ |
406 // AddP ( base == top )
407 //
408 // case #4. Array's element reference:
409 // {CheckCastPP | CastPP}
410 // | | |
411 // | AddP ( array's element offset )
412 // | |
413 // AddP ( array's offset )
414 //
415 // case #5. Raw object's field reference for arraycopy stub call:
416 // The inline_native_clone() case when the arraycopy stub is called
417 // after the allocation before Initialize and CheckCastPP nodes.
418 // Allocate
419 // |
420 // Proj #5 ( oop result )
421 // | |
422 // AddP ( base == address )
423 //
424 // case #6. Constant Pool, ThreadLocal, CastX2P or
425 // Raw object's field reference:
426 // {ConP, ThreadLocal, CastX2P, raw Load}
427 // top |
428 // \ |
429 // AddP ( base == top )
430 //
431 // case #7. Klass's field reference.
432 // LoadKlass
433 // | |
434 // AddP ( base == address )
435 //
436 // case #8. narrow Klass's field reference.
437 // LoadNKlass
438 // |
439 // DecodeN
440 // | |
441 // AddP ( base == address )
442 //
443 Node *base = addp->in(AddPNode::Base)->uncast();
444 if (base->is_top()) { // The AddP case #3 and #6.
445 base = addp->in(AddPNode::Address)->uncast();
446 while (base->is_AddP()) {
447 // Case #6 (unsafe access) may have several chained AddP nodes.
448 assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
449 base = base->in(AddPNode::Address)->uncast();
450 }
451 assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
452 base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
453 (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
454 (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
455 }
456 return base;
457 }
458
459 static Node* find_second_addp(Node* addp, Node* n) {
460 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
461
462 Node* addp2 = addp->raw_out(0);
463 if (addp->outcnt() == 1 && addp2->is_AddP() &&
464 addp2->in(AddPNode::Base) == n &&
465 addp2->in(AddPNode::Address) == addp) {
466
467 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
468 //
469 // Find array's offset to push it on worklist first and
470 // as result process an array's element offset first (pushed second)
471 // to avoid CastPP for the array's offset.
472 // Otherwise the inserted CastPP (LocalVar) will point to what
473 // the AddP (Field) points to. Which would be wrong since
474 // the algorithm expects the CastPP has the same point as
475 // as AddP's base CheckCastPP (LocalVar).
476 //
477 // ArrayAllocation
478 // |
479 // CheckCastPP
480 // |
481 // memProj (from ArrayAllocation CheckCastPP)
482 // | ||
483 // | || Int (element index)
484 // | || | ConI (log(element size))
485 // | || | /
486 // | || LShift
487 // | || /
488 // | AddP (array's element offset)
489 // | |
490 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
491 // | / /
492 // AddP (array's offset)
493 // |
494 // Load/Store (memory operation on array's element)
495 //
496 return addp2;
497 }
498 return NULL;
499 }
500
501 //
502 // Adjust the type and inputs of an AddP which computes the
503 // address of a field of an instance
504 //
505 bool ConnectionGraph::split_AddP(Node *addp, Node *base, PhaseGVN *igvn) {
506 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
507 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
508 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
509 if (t == NULL) {
510 // We are computing a raw address for a store captured by an Initialize
511 // compute an appropriate address type (cases #3 and #5).
512 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
513 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
514 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
515 assert(offs != Type::OffsetBot, "offset must be a constant");
516 t = base_t->add_offset(offs)->is_oopptr();
517 }
518 int inst_id = base_t->instance_id();
519 assert(!t->is_known_instance() || t->instance_id() == inst_id,
520 "old type must be non-instance or match new type");
521
522 // The type 't' could be subclass of 'base_t'.
523 // As result t->offset() could be large then base_t's size and it will
524 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
525 // constructor verifies correctness of the offset.
526 //
527 // It could happened on subclass's branch (from the type profiling
528 // inlining) which was not eliminated during parsing since the exactness
529 // of the allocation type was not propagated to the subclass type check.
530 //
531 // Or the type 't' could be not related to 'base_t' at all.
532 // It could happened when CHA type is different from MDO type on a dead path
533 // (for example, from instanceof check) which is not collapsed during parsing.
534 //
535 // Do nothing for such AddP node and don't process its users since
536 // this code branch will go away.
537 //
538 if (!t->is_known_instance() &&
539 !base_t->klass()->is_subtype_of(t->klass())) {
540 return false; // bail out
541 }
542
543 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
544 // Do NOT remove the next line: ensure a new alias index is allocated
545 // for the instance type. Note: C++ will not remove it since the call
546 // has side effect.
547 int alias_idx = _compile->get_alias_index(tinst);
548 igvn->set_type(addp, tinst);
549 // record the allocation in the node map
550 assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
551 set_map(addp->_idx, get_map(base->_idx));
552
553 // Set addp's Base and Address to 'base'.
554 Node *abase = addp->in(AddPNode::Base);
555 Node *adr = addp->in(AddPNode::Address);
556 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
557 adr->in(0)->_idx == (uint)inst_id) {
558 // Skip AddP cases #3 and #5.
559 } else {
560 assert(!abase->is_top(), "sanity"); // AddP case #3
561 if (abase != base) {
562 igvn->hash_delete(addp);
563 addp->set_req(AddPNode::Base, base);
564 if (abase == adr) {
565 addp->set_req(AddPNode::Address, base);
566 } else {
567 // AddP case #4 (adr is array's element offset AddP node)
568 #ifdef ASSERT
569 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
570 assert(adr->is_AddP() && atype != NULL &&
571 atype->instance_id() == inst_id, "array's element offset should be processed first");
572 #endif
573 }
574 igvn->hash_insert(addp);
575 }
576 }
577 // Put on IGVN worklist since at least addp's type was changed above.
578 record_for_optimizer(addp);
579 return true;
580 }
581
582 //
583 // Create a new version of orig_phi if necessary. Returns either the newly
584 // created phi or an existing phi. Sets create_new to indicate wheter a new
585 // phi was created. Cache the last newly created phi in the node map.
586 //
587 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created) {
588 Compile *C = _compile;
589 new_created = false;
590 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
591 // nothing to do if orig_phi is bottom memory or matches alias_idx
592 if (phi_alias_idx == alias_idx) {
593 return orig_phi;
594 }
595 // Have we recently created a Phi for this alias index?
596 PhiNode *result = get_map_phi(orig_phi->_idx);
597 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
598 return result;
599 }
600 // Previous check may fail when the same wide memory Phi was split into Phis
601 // for different memory slices. Search all Phis for this region.
602 if (result != NULL) {
603 Node* region = orig_phi->in(0);
604 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
605 Node* phi = region->fast_out(i);
606 if (phi->is_Phi() &&
607 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
608 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
609 return phi->as_Phi();
610 }
611 }
612 }
613 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
614 if (C->do_escape_analysis() == true && !C->failing()) {
615 // Retry compilation without escape analysis.
616 // If this is the first failure, the sentinel string will "stick"
617 // to the Compile object, and the C2Compiler will see it and retry.
618 C->record_failure(C2Compiler::retry_no_escape_analysis());
619 }
620 return NULL;
621 }
622 orig_phi_worklist.append_if_missing(orig_phi);
623 const TypePtr *atype = C->get_adr_type(alias_idx);
624 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
625 C->copy_node_notes_to(result, orig_phi);
626 igvn->set_type(result, result->bottom_type());
627 record_for_optimizer(result);
628
629 debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
630 assert(pn == NULL || pn == orig_phi, "wrong node");
631 set_map(orig_phi->_idx, result);
632 ptnode_adr(orig_phi->_idx)->_node = orig_phi;
633
634 new_created = true;
635 return result;
636 }
637
638 //
639 // Return a new version of Memory Phi "orig_phi" with the inputs having the
640 // specified alias index.
641 //
642 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
643
644 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
645 Compile *C = _compile;
646 bool new_phi_created;
647 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
648 if (!new_phi_created) {
649 return result;
650 }
651
652 GrowableArray<PhiNode *> phi_list;
653 GrowableArray<uint> cur_input;
654
655 PhiNode *phi = orig_phi;
656 uint idx = 1;
657 bool finished = false;
658 while(!finished) {
659 while (idx < phi->req()) {
660 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
661 if (mem != NULL && mem->is_Phi()) {
662 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
663 if (new_phi_created) {
664 // found an phi for which we created a new split, push current one on worklist and begin
665 // processing new one
666 phi_list.push(phi);
667 cur_input.push(idx);
668 phi = mem->as_Phi();
669 result = newphi;
670 idx = 1;
671 continue;
672 } else {
673 mem = newphi;
674 }
675 }
676 if (C->failing()) {
677 return NULL;
678 }
679 result->set_req(idx++, mem);
680 }
681 #ifdef ASSERT
682 // verify that the new Phi has an input for each input of the original
683 assert( phi->req() == result->req(), "must have same number of inputs.");
684 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
685 #endif
686 // Check if all new phi's inputs have specified alias index.
687 // Otherwise use old phi.
688 for (uint i = 1; i < phi->req(); i++) {
689 Node* in = result->in(i);
690 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
691 }
692 // we have finished processing a Phi, see if there are any more to do
693 finished = (phi_list.length() == 0 );
694 if (!finished) {
695 phi = phi_list.pop();
696 idx = cur_input.pop();
697 PhiNode *prev_result = get_map_phi(phi->_idx);
698 prev_result->set_req(idx++, result);
699 result = prev_result;
700 }
701 }
702 return result;
703 }
704
705
706 //
707 // The next methods are derived from methods in MemNode.
708 //
709 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
710 Node *mem = mmem;
711 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
712 // means an array I have not precisely typed yet. Do not do any
713 // alias stuff with it any time soon.
714 if( toop->base() != Type::AnyPtr &&
715 !(toop->klass() != NULL &&
716 toop->klass()->is_java_lang_Object() &&
717 toop->offset() == Type::OffsetBot) ) {
718 mem = mmem->memory_at(alias_idx);
719 // Update input if it is progress over what we have now
720 }
721 return mem;
722 }
723
724 //
725 // Move memory users to their memory slices.
726 //
727 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *igvn) {
728 Compile* C = _compile;
729
730 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
731 assert(tp != NULL, "ptr type");
732 int alias_idx = C->get_alias_index(tp);
733 int general_idx = C->get_general_index(alias_idx);
734
735 // Move users first
736 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
737 Node* use = n->fast_out(i);
738 if (use->is_MergeMem()) {
739 MergeMemNode* mmem = use->as_MergeMem();
740 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
741 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
742 continue; // Nothing to do
743 }
744 // Replace previous general reference to mem node.
745 uint orig_uniq = C->unique();
746 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
747 assert(orig_uniq == C->unique(), "no new nodes");
748 mmem->set_memory_at(general_idx, m);
749 --imax;
750 --i;
751 } else if (use->is_MemBar()) {
752 assert(!use->is_Initialize(), "initializing stores should not be moved");
753 if (use->req() > MemBarNode::Precedent &&
754 use->in(MemBarNode::Precedent) == n) {
755 // Don't move related membars.
756 record_for_optimizer(use);
757 continue;
758 }
759 tp = use->as_MemBar()->adr_type()->isa_ptr();
760 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
761 alias_idx == general_idx) {
762 continue; // Nothing to do
763 }
764 // Move to general memory slice.
765 uint orig_uniq = C->unique();
766 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
767 assert(orig_uniq == C->unique(), "no new nodes");
768 igvn->hash_delete(use);
769 imax -= use->replace_edge(n, m);
770 igvn->hash_insert(use);
771 record_for_optimizer(use);
772 --i;
773 #ifdef ASSERT
774 } else if (use->is_Mem()) {
775 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
776 // Don't move related cardmark.
777 continue;
778 }
779 // Memory nodes should have new memory input.
780 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
781 assert(tp != NULL, "ptr type");
782 int idx = C->get_alias_index(tp);
783 assert(get_map(use->_idx) != NULL || idx == alias_idx,
784 "Following memory nodes should have new memory input or be on the same memory slice");
785 } else if (use->is_Phi()) {
786 // Phi nodes should be split and moved already.
787 tp = use->as_Phi()->adr_type()->isa_ptr();
788 assert(tp != NULL, "ptr type");
789 int idx = C->get_alias_index(tp);
790 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
791 } else {
792 use->dump();
793 assert(false, "should not be here");
794 #endif
795 }
796 }
797 }
798
799 //
800 // Search memory chain of "mem" to find a MemNode whose address
801 // is the specified alias index.
802 //
803 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *phase) {
804 if (orig_mem == NULL)
805 return orig_mem;
806 Compile* C = phase->C;
807 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
808 bool is_instance = (toop != NULL) && toop->is_known_instance();
809 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
810 Node *prev = NULL;
811 Node *result = orig_mem;
812 while (prev != result) {
813 prev = result;
814 if (result == start_mem)
815 break; // hit one of our sentinels
816 if (result->is_Mem()) {
817 const Type *at = phase->type(result->in(MemNode::Address));
818 if (at != Type::TOP) {
819 assert (at->isa_ptr() != NULL, "pointer type required.");
820 int idx = C->get_alias_index(at->is_ptr());
821 if (idx == alias_idx)
822 break;
823 }
824 result = result->in(MemNode::Memory);
825 }
826 if (!is_instance)
827 continue; // don't search further for non-instance types
828 // skip over a call which does not affect this memory slice
829 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
830 Node *proj_in = result->in(0);
831 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
832 break; // hit one of our sentinels
833 } else if (proj_in->is_Call()) {
834 CallNode *call = proj_in->as_Call();
835 if (!call->may_modify(toop, phase)) {
836 result = call->in(TypeFunc::Memory);
837 }
838 } else if (proj_in->is_Initialize()) {
839 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
840 // Stop if this is the initialization for the object instance which
841 // which contains this memory slice, otherwise skip over it.
842 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
843 result = proj_in->in(TypeFunc::Memory);
844 }
845 } else if (proj_in->is_MemBar()) {
846 result = proj_in->in(TypeFunc::Memory);
847 }
848 } else if (result->is_MergeMem()) {
849 MergeMemNode *mmem = result->as_MergeMem();
850 result = step_through_mergemem(mmem, alias_idx, toop);
851 if (result == mmem->base_memory()) {
852 // Didn't find instance memory, search through general slice recursively.
853 result = mmem->memory_at(C->get_general_index(alias_idx));
854 result = find_inst_mem(result, alias_idx, orig_phis, phase);
855 if (C->failing()) {
856 return NULL;
857 }
858 mmem->set_memory_at(alias_idx, result);
859 }
860 } else if (result->is_Phi() &&
861 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
862 Node *un = result->as_Phi()->unique_input(phase);
863 if (un != NULL) {
864 orig_phis.append_if_missing(result->as_Phi());
865 result = un;
866 } else {
867 break;
868 }
869 } else if (result->is_ClearArray()) {
870 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
871 // Can not bypass initialization of the instance
872 // we are looking for.
873 break;
874 }
875 // Otherwise skip it (the call updated 'result' value).
876 } else if (result->Opcode() == Op_SCMemProj) {
877 assert(result->in(0)->is_LoadStore(), "sanity");
878 const Type *at = phase->type(result->in(0)->in(MemNode::Address));
879 if (at != Type::TOP) {
880 assert (at->isa_ptr() != NULL, "pointer type required.");
881 int idx = C->get_alias_index(at->is_ptr());
882 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
883 break;
884 }
885 result = result->in(0)->in(MemNode::Memory);
886 }
887 }
888 if (result->is_Phi()) {
889 PhiNode *mphi = result->as_Phi();
890 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
891 const TypePtr *t = mphi->adr_type();
892 if (C->get_alias_index(t) != alias_idx) {
893 // Create a new Phi with the specified alias index type.
894 result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
895 } else if (!is_instance) {
896 // Push all non-instance Phis on the orig_phis worklist to update inputs
897 // during Phase 4 if needed.
898 orig_phis.append_if_missing(mphi);
899 }
900 }
901 // the result is either MemNode, PhiNode, InitializeNode.
902 return result;
903 }
904
905 //
906 // Convert the types of unescaped object to instance types where possible,
907 // propagate the new type information through the graph, and update memory
908 // edges and MergeMem inputs to reflect the new type.
909 //
910 // We start with allocations (and calls which may be allocations) on alloc_worklist.
911 // The processing is done in 4 phases:
912 //
913 // Phase 1: Process possible allocations from alloc_worklist. Create instance
914 // types for the CheckCastPP for allocations where possible.
915 // Propagate the the new types through users as follows:
916 // casts and Phi: push users on alloc_worklist
917 // AddP: cast Base and Address inputs to the instance type
918 // push any AddP users on alloc_worklist and push any memnode
919 // users onto memnode_worklist.
920 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
921 // search the Memory chain for a store with the appropriate type
922 // address type. If a Phi is found, create a new version with
923 // the appropriate memory slices from each of the Phi inputs.
924 // For stores, process the users as follows:
925 // MemNode: push on memnode_worklist
926 // MergeMem: push on mergemem_worklist
927 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
928 // moving the first node encountered of each instance type to the
929 // the input corresponding to its alias index.
930 // appropriate memory slice.
931 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
932 //
933 // In the following example, the CheckCastPP nodes are the cast of allocation
934 // results and the allocation of node 29 is unescaped and eligible to be an
935 // instance type.
936 //
937 // We start with:
938 //
939 // 7 Parm #memory
940 // 10 ConI "12"
941 // 19 CheckCastPP "Foo"
942 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
943 // 29 CheckCastPP "Foo"
944 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
945 //
946 // 40 StoreP 25 7 20 ... alias_index=4
947 // 50 StoreP 35 40 30 ... alias_index=4
948 // 60 StoreP 45 50 20 ... alias_index=4
949 // 70 LoadP _ 60 30 ... alias_index=4
950 // 80 Phi 75 50 60 Memory alias_index=4
951 // 90 LoadP _ 80 30 ... alias_index=4
952 // 100 LoadP _ 80 20 ... alias_index=4
953 //
954 //
955 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
956 // and creating a new alias index for node 30. This gives:
957 //
958 // 7 Parm #memory
959 // 10 ConI "12"
960 // 19 CheckCastPP "Foo"
961 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
962 // 29 CheckCastPP "Foo" iid=24
963 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
964 //
965 // 40 StoreP 25 7 20 ... alias_index=4
966 // 50 StoreP 35 40 30 ... alias_index=6
967 // 60 StoreP 45 50 20 ... alias_index=4
968 // 70 LoadP _ 60 30 ... alias_index=6
969 // 80 Phi 75 50 60 Memory alias_index=4
970 // 90 LoadP _ 80 30 ... alias_index=6
971 // 100 LoadP _ 80 20 ... alias_index=4
972 //
973 // In phase 2, new memory inputs are computed for the loads and stores,
974 // And a new version of the phi is created. In phase 4, the inputs to
975 // node 80 are updated and then the memory nodes are updated with the
976 // values computed in phase 2. This results in:
977 //
978 // 7 Parm #memory
979 // 10 ConI "12"
980 // 19 CheckCastPP "Foo"
981 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
982 // 29 CheckCastPP "Foo" iid=24
983 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
984 //
985 // 40 StoreP 25 7 20 ... alias_index=4
986 // 50 StoreP 35 7 30 ... alias_index=6
987 // 60 StoreP 45 40 20 ... alias_index=4
988 // 70 LoadP _ 50 30 ... alias_index=6
989 // 80 Phi 75 40 60 Memory alias_index=4
990 // 120 Phi 75 50 50 Memory alias_index=6
991 // 90 LoadP _ 120 30 ... alias_index=6
992 // 100 LoadP _ 80 20 ... alias_index=4
993 //
994 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
995 GrowableArray<Node *> memnode_worklist;
996 GrowableArray<PhiNode *> orig_phis;
997
998 PhaseGVN *igvn = _igvn;
999 uint new_index_start = (uint) _compile->num_alias_types();
1000 Arena* arena = Thread::current()->resource_area();
1001 VectorSet visited(arena);
1002 VectorSet ptset(arena);
1003
1004
1005 // Phase 1: Process possible allocations from alloc_worklist.
1006 // Create instance types for the CheckCastPP for allocations where possible.
1007 //
1008 // (Note: don't forget to change the order of the second AddP node on
1009 // the alloc_worklist if the order of the worklist processing is changed,
1010 // see the comment in find_second_addp().)
1011 //
1012 while (alloc_worklist.length() != 0) {
1013 Node *n = alloc_worklist.pop();
1014 uint ni = n->_idx;
1015 const TypeOopPtr* tinst = NULL;
1016 if (n->is_Call()) {
1017 CallNode *alloc = n->as_Call();
1018 // copy escape information to call node
1019 PointsToNode* ptn = ptnode_adr(alloc->_idx);
1020 PointsToNode::EscapeState es = escape_state(alloc);
1021 // We have an allocation or call which returns a Java object,
1022 // see if it is unescaped.
1023 if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
1024 continue;
1025
1026 // Find CheckCastPP for the allocate or for the return value of a call
1027 n = alloc->result_cast();
1028 if (n == NULL) { // No uses except Initialize node
1029 if (alloc->is_Allocate()) {
1030 // Set the scalar_replaceable flag for allocation
1031 // so it could be eliminated if it has no uses.
1032 alloc->as_Allocate()->_is_scalar_replaceable = true;
1033 }
1034 continue;
1035 }
1036 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1037 assert(!alloc->is_Allocate(), "allocation should have unique type");
1038 continue;
1039 }
1040
1041 // The inline code for Object.clone() casts the allocation result to
1042 // java.lang.Object and then to the actual type of the allocated
1043 // object. Detect this case and use the second cast.
1044 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
1045 // the allocation result is cast to java.lang.Object and then
1046 // to the actual Array type.
1047 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
1048 && (alloc->is_AllocateArray() ||
1049 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
1050 Node *cast2 = NULL;
1051 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1052 Node *use = n->fast_out(i);
1053 if (use->is_CheckCastPP()) {
1054 cast2 = use;
1055 break;
1056 }
1057 }
1058 if (cast2 != NULL) {
1059 n = cast2;
1060 } else {
1061 // Non-scalar replaceable if the allocation type is unknown statically
1062 // (reflection allocation), the object can't be restored during
1063 // deoptimization without precise type.
1064 continue;
1065 }
1066 }
1067 if (alloc->is_Allocate()) {
1068 // Set the scalar_replaceable flag for allocation
1069 // so it could be eliminated.
1070 alloc->as_Allocate()->_is_scalar_replaceable = true;
1071 }
1072 set_escape_state(n->_idx, es);
1073 // in order for an object to be scalar-replaceable, it must be:
1074 // - a direct allocation (not a call returning an object)
1075 // - non-escaping
1076 // - eligible to be a unique type
1077 // - not determined to be ineligible by escape analysis
1078 assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1079 ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1080 set_map(alloc->_idx, n);
1081 set_map(n->_idx, alloc);
1082 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1083 if (t == NULL)
1084 continue; // not a TypeInstPtr
1085 tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1086 igvn->hash_delete(n);
1087 igvn->set_type(n, tinst);
1088 n->raise_bottom_type(tinst);
1089 igvn->hash_insert(n);
1090 record_for_optimizer(n);
1091 if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
1092 (t->isa_instptr() || t->isa_aryptr())) {
1093
1094 // First, put on the worklist all Field edges from Connection Graph
1095 // which is more accurate then putting immediate users from Ideal Graph.
1096 for (uint e = 0; e < ptn->edge_count(); e++) {
1097 Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1098 assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
1099 "only AddP nodes are Field edges in CG");
1100 if (use->outcnt() > 0) { // Don't process dead nodes
1101 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1102 if (addp2 != NULL) {
1103 assert(alloc->is_AllocateArray(),"array allocation was expected");
1104 alloc_worklist.append_if_missing(addp2);
1105 }
1106 alloc_worklist.append_if_missing(use);
1107 }
1108 }
1109
1110 // An allocation may have an Initialize which has raw stores. Scan
1111 // the users of the raw allocation result and push AddP users
1112 // on alloc_worklist.
1113 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1114 assert (raw_result != NULL, "must have an allocation result");
1115 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1116 Node *use = raw_result->fast_out(i);
1117 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1118 Node* addp2 = find_second_addp(use, raw_result);
1119 if (addp2 != NULL) {
1120 assert(alloc->is_AllocateArray(),"array allocation was expected");
1121 alloc_worklist.append_if_missing(addp2);
1122 }
1123 alloc_worklist.append_if_missing(use);
1124 } else if (use->is_MemBar()) {
1125 memnode_worklist.append_if_missing(use);
1126 }
1127 }
1128 }
1129 } else if (n->is_AddP()) {
1130 ptset.Clear();
1131 PointsTo(ptset, get_addp_base(n));
1132 assert(ptset.Size() == 1, "AddP address is unique");
1133 uint elem = ptset.getelem(); // Allocation node's index
1134 if (elem == _phantom_object) {
1135 assert(false, "escaped allocation");
1136 continue; // Assume the value was set outside this method.
1137 }
1138 Node *base = get_map(elem); // CheckCastPP node
1139 if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1140 tinst = igvn->type(base)->isa_oopptr();
1141 } else if (n->is_Phi() ||
1142 n->is_CheckCastPP() ||
1143 n->is_EncodeP() ||
1144 n->is_DecodeN() ||
1145 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1146 if (visited.test_set(n->_idx)) {
1147 assert(n->is_Phi(), "loops only through Phi's");
1148 continue; // already processed
1149 }
1150 ptset.Clear();
1151 PointsTo(ptset, n);
1152 if (ptset.Size() == 1) {
1153 uint elem = ptset.getelem(); // Allocation node's index
1154 if (elem == _phantom_object) {
1155 assert(false, "escaped allocation");
1156 continue; // Assume the value was set outside this method.
1157 }
1158 Node *val = get_map(elem); // CheckCastPP node
1159 TypeNode *tn = n->as_Type();
1160 tinst = igvn->type(val)->isa_oopptr();
1161 assert(tinst != NULL && tinst->is_known_instance() &&
1162 (uint)tinst->instance_id() == elem , "instance type expected.");
1163
1164 const Type *tn_type = igvn->type(tn);
1165 const TypeOopPtr *tn_t;
1166 if (tn_type->isa_narrowoop()) {
1167 tn_t = tn_type->make_ptr()->isa_oopptr();
1168 } else {
1169 tn_t = tn_type->isa_oopptr();
1170 }
1171
1172 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1173 if (tn_type->isa_narrowoop()) {
1174 tn_type = tinst->make_narrowoop();
1175 } else {
1176 tn_type = tinst;
1177 }
1178 igvn->hash_delete(tn);
1179 igvn->set_type(tn, tn_type);
1180 tn->set_type(tn_type);
1181 igvn->hash_insert(tn);
1182 record_for_optimizer(n);
1183 } else {
1184 assert(tn_type == TypePtr::NULL_PTR ||
1185 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
1186 "unexpected type");
1187 continue; // Skip dead path with different type
1188 }
1189 }
1190 } else {
1191 debug_only(n->dump();)
1192 assert(false, "EA: unexpected node");
1193 continue;
1194 }
1195 // push allocation's users on appropriate worklist
1196 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1197 Node *use = n->fast_out(i);
1198 if(use->is_Mem() && use->in(MemNode::Address) == n) {
1199 // Load/store to instance's field
1200 memnode_worklist.append_if_missing(use);
1201 } else if (use->is_MemBar()) {
1202 memnode_worklist.append_if_missing(use);
1203 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1204 Node* addp2 = find_second_addp(use, n);
1205 if (addp2 != NULL) {
1206 alloc_worklist.append_if_missing(addp2);
1207 }
1208 alloc_worklist.append_if_missing(use);
1209 } else if (use->is_Phi() ||
1210 use->is_CheckCastPP() ||
1211 use->is_EncodeP() ||
1212 use->is_DecodeN() ||
1213 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1214 alloc_worklist.append_if_missing(use);
1215 #ifdef ASSERT
1216 } else if (use->is_Mem()) {
1217 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
1218 } else if (use->is_MergeMem()) {
1219 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1220 } else if (use->is_SafePoint()) {
1221 // Look for MergeMem nodes for calls which reference unique allocation
1222 // (through CheckCastPP nodes) even for debug info.
1223 Node* m = use->in(TypeFunc::Memory);
1224 if (m->is_MergeMem()) {
1225 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1226 }
1227 } else {
1228 uint op = use->Opcode();
1229 if (!(op == Op_CmpP || op == Op_Conv2B ||
1230 op == Op_CastP2X || op == Op_StoreCM ||
1231 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1232 op == Op_StrEquals || op == Op_StrIndexOf)) {
1233 n->dump();
1234 use->dump();
1235 assert(false, "EA: missing allocation reference path");
1236 }
1237 #endif
1238 }
1239 }
1240
1241 }
1242 // New alias types were created in split_AddP().
1243 uint new_index_end = (uint) _compile->num_alias_types();
1244
1245 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1246 // compute new values for Memory inputs (the Memory inputs are not
1247 // actually updated until phase 4.)
1248 if (memnode_worklist.length() == 0)
1249 return; // nothing to do
1250
1251 while (memnode_worklist.length() != 0) {
1252 Node *n = memnode_worklist.pop();
1253 if (visited.test_set(n->_idx))
1254 continue;
1255 if (n->is_Phi() || n->is_ClearArray()) {
1256 // we don't need to do anything, but the users must be pushed
1257 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1258 // we don't need to do anything, but the users must be pushed
1259 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1260 if (n == NULL)
1261 continue;
1262 } else {
1263 assert(n->is_Mem(), "memory node required.");
1264 Node *addr = n->in(MemNode::Address);
1265 const Type *addr_t = igvn->type(addr);
1266 if (addr_t == Type::TOP)
1267 continue;
1268 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1269 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1270 assert ((uint)alias_idx < new_index_end, "wrong alias index");
1271 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1272 if (_compile->failing()) {
1273 return;
1274 }
1275 if (mem != n->in(MemNode::Memory)) {
1276 // We delay the memory edge update since we need old one in
1277 // MergeMem code below when instances memory slices are separated.
1278 debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1279 assert(pn == NULL || pn == n, "wrong node");
1280 set_map(n->_idx, mem);
1281 ptnode_adr(n->_idx)->_node = n;
1282 }
1283 if (n->is_Load()) {
1284 continue; // don't push users
1285 } else if (n->is_LoadStore()) {
1286 // get the memory projection
1287 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1288 Node *use = n->fast_out(i);
1289 if (use->Opcode() == Op_SCMemProj) {
1290 n = use;
1291 break;
1292 }
1293 }
1294 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1295 }
1296 }
1297 // push user on appropriate worklist
1298 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1299 Node *use = n->fast_out(i);
1300 if (use->is_Phi() || use->is_ClearArray()) {
1301 memnode_worklist.append_if_missing(use);
1302 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1303 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
1304 continue;
1305 memnode_worklist.append_if_missing(use);
1306 } else if (use->is_MemBar()) {
1307 memnode_worklist.append_if_missing(use);
1308 #ifdef ASSERT
1309 } else if(use->is_Mem()) {
1310 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
1311 } else if (use->is_MergeMem()) {
1312 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1313 } else {
1314 uint op = use->Opcode();
1315 if (!(op == Op_StoreCM ||
1316 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
1317 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
1318 op == Op_AryEq || op == Op_StrComp ||
1319 op == Op_StrEquals || op == Op_StrIndexOf)) {
1320 n->dump();
1321 use->dump();
1322 assert(false, "EA: missing memory path");
1323 }
1324 #endif
1325 }
1326 }
1327 }
1328
1329 // Phase 3: Process MergeMem nodes from mergemem_worklist.
1330 // Walk each memory slice moving the first node encountered of each
1331 // instance type to the the input corresponding to its alias index.
1332 uint length = _mergemem_worklist.length();
1333 for( uint next = 0; next < length; ++next ) {
1334 MergeMemNode* nmm = _mergemem_worklist.at(next);
1335 assert(!visited.test_set(nmm->_idx), "should not be visited before");
1336 // Note: we don't want to use MergeMemStream here because we only want to
1337 // scan inputs which exist at the start, not ones we add during processing.
1338 // Note 2: MergeMem may already contains instance memory slices added
1339 // during find_inst_mem() call when memory nodes were processed above.
1340 igvn->hash_delete(nmm);
1341 uint nslices = nmm->req();
1342 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1343 Node* mem = nmm->in(i);
1344 Node* cur = NULL;
1345 if (mem == NULL || mem->is_top())
1346 continue;
1347 // First, update mergemem by moving memory nodes to corresponding slices
1348 // if their type became more precise since this mergemem was created.
1349 while (mem->is_Mem()) {
1350 const Type *at = igvn->type(mem->in(MemNode::Address));
1351 if (at != Type::TOP) {
1352 assert (at->isa_ptr() != NULL, "pointer type required.");
1353 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1354 if (idx == i) {
1355 if (cur == NULL)
1356 cur = mem;
1357 } else {
1358 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1359 nmm->set_memory_at(idx, mem);
1360 }
1361 }
1362 }
1363 mem = mem->in(MemNode::Memory);
1364 }
1365 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1366 // Find any instance of the current type if we haven't encountered
1367 // already a memory slice of the instance along the memory chain.
1368 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1369 if((uint)_compile->get_general_index(ni) == i) {
1370 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1371 if (nmm->is_empty_memory(m)) {
1372 Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1373 if (_compile->failing()) {
1374 return;
1375 }
1376 nmm->set_memory_at(ni, result);
1377 }
1378 }
1379 }
1380 }
1381 // Find the rest of instances values
1382 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1383 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
1384 Node* result = step_through_mergemem(nmm, ni, tinst);
1385 if (result == nmm->base_memory()) {
1386 // Didn't find instance memory, search through general slice recursively.
1387 result = nmm->memory_at(_compile->get_general_index(ni));
1388 result = find_inst_mem(result, ni, orig_phis, igvn);
1389 if (_compile->failing()) {
1390 return;
1391 }
1392 nmm->set_memory_at(ni, result);
1393 }
1394 }
1395 igvn->hash_insert(nmm);
1396 record_for_optimizer(nmm);
1397 }
1398
1399 // Phase 4: Update the inputs of non-instance memory Phis and
1400 // the Memory input of memnodes
1401 // First update the inputs of any non-instance Phi's from
1402 // which we split out an instance Phi. Note we don't have
1403 // to recursively process Phi's encounted on the input memory
1404 // chains as is done in split_memory_phi() since they will
1405 // also be processed here.
1406 for (int j = 0; j < orig_phis.length(); j++) {
1407 PhiNode *phi = orig_phis.at(j);
1408 int alias_idx = _compile->get_alias_index(phi->adr_type());
1409 igvn->hash_delete(phi);
1410 for (uint i = 1; i < phi->req(); i++) {
1411 Node *mem = phi->in(i);
1412 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1413 if (_compile->failing()) {
1414 return;
1415 }
1416 if (mem != new_mem) {
1417 phi->set_req(i, new_mem);
1418 }
1419 }
1420 igvn->hash_insert(phi);
1421 record_for_optimizer(phi);
1422 }
1423
1424 // Update the memory inputs of MemNodes with the value we computed
1425 // in Phase 2 and move stores memory users to corresponding memory slices.
1426 #ifdef ASSERT
1427 visited.Clear();
1428 Node_Stack old_mems(arena, _compile->unique() >> 2);
1429 #endif
1430 for (uint i = 0; i < nodes_size(); i++) {
1431 Node *nmem = get_map(i);
1432 if (nmem != NULL) {
1433 Node *n = ptnode_adr(i)->_node;
1434 assert(n != NULL, "sanity");
1435 if (n->is_Mem()) {
1436 #ifdef ASSERT
1437 Node* old_mem = n->in(MemNode::Memory);
1438 if (!visited.test_set(old_mem->_idx)) {
1439 old_mems.push(old_mem, old_mem->outcnt());
1440 }
1441 #endif
1442 assert(n->in(MemNode::Memory) != nmem, "sanity");
1443 if (!n->is_Load()) {
1444 // Move memory users of a store first.
1445 move_inst_mem(n, orig_phis, igvn);
1446 }
1447 // Now update memory input
1448 igvn->hash_delete(n);
1449 n->set_req(MemNode::Memory, nmem);
1450 igvn->hash_insert(n);
1451 record_for_optimizer(n);
1452 } else {
1453 assert(n->is_Allocate() || n->is_CheckCastPP() ||
1454 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1455 }
1456 }
1457 }
1458 #ifdef ASSERT
1459 // Verify that memory was split correctly
1460 while (old_mems.is_nonempty()) {
1461 Node* old_mem = old_mems.node();
1462 uint old_cnt = old_mems.index();
1463 old_mems.pop();
1464 assert(old_cnt = old_mem->outcnt(), "old mem could be lost");
1465 }
1466 #endif
1467 }
1468
1469 bool ConnectionGraph::has_candidates(Compile *C) {
1470 // EA brings benefits only when the code has allocations and/or locks which
1471 // are represented by ideal Macro nodes.
1472 int cnt = C->macro_count();
1473 for( int i=0; i < cnt; i++ ) {
1474 Node *n = C->macro_node(i);
1475 if ( n->is_Allocate() )
1476 return true;
1477 if( n->is_Lock() ) {
1478 Node* obj = n->as_Lock()->obj_node()->uncast();
1479 if( !(obj->is_Parm() || obj->is_Con()) )
1480 return true;
1481 }
1482 }
1483 return false;
1484 }
1485
1486 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1487 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1488 // to create space for them in ConnectionGraph::_nodes[].
1489 Node* oop_null = igvn->zerocon(T_OBJECT);
1490 Node* noop_null = igvn->zerocon(T_NARROWOOP);
1491
1492 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1493 // Perform escape analysis
1494 if (congraph->compute_escape()) {
1495 // There are non escaping objects.
1496 C->set_congraph(congraph);
1497 }
1498
1499 // Cleanup.
1500 if (oop_null->outcnt() == 0)
1501 igvn->hash_delete(oop_null);
1502 if (noop_null->outcnt() == 0)
1503 igvn->hash_delete(noop_null);
1504 }
1505
1506 bool ConnectionGraph::compute_escape() {
1507 Compile* C = _compile;
1508
1509 // 1. Populate Connection Graph (CG) with Ideal nodes.
1510
1511 Unique_Node_List worklist_init;
1512 worklist_init.map(C->unique(), NULL); // preallocate space
1513
1514 // Initialize worklist
1515 if (C->root() != NULL) {
1516 worklist_init.push(C->root());
1517 }
1518
1519 GrowableArray<int> cg_worklist;
1520 PhaseGVN* igvn = _igvn;
1521 bool has_allocations = false;
1522
1523 // Push all useful nodes onto CG list and set their type.
1524 for( uint next = 0; next < worklist_init.size(); ++next ) {
1525 Node* n = worklist_init.at(next);
1526 record_for_escape_analysis(n, igvn);
1527 // Only allocations and java static calls results are checked
1528 // for an escape status. See process_call_result() below.
1529 if (n->is_Allocate() || n->is_CallStaticJava() &&
1530 ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1531 has_allocations = true;
1532 }
1533 if(n->is_AddP()) {
1534 // Collect address nodes which directly reference an allocation.
1535 // Use them during stage 3 below to build initial connection graph
1536 // field edges. Other field edges could be added after StoreP/LoadP
1537 // nodes are processed during stage 4 below.
1538 Node* base = get_addp_base(n);
1539 if(base->is_Proj() && base->in(0)->is_Allocate()) {
1540 cg_worklist.append(n->_idx);
1541 }
1542 } else if (n->is_MergeMem()) {
1543 // Collect all MergeMem nodes to add memory slices for
1544 // scalar replaceable objects in split_unique_types().
1545 _mergemem_worklist.append(n->as_MergeMem());
1546 }
1547 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1548 Node* m = n->fast_out(i); // Get user
1549 worklist_init.push(m);
1550 }
1551 }
1552
1553 if (!has_allocations) {
1554 _collecting = false;
1555 return false; // Nothing to do.
1556 }
1557
1558 // 2. First pass to create simple CG edges (doesn't require to walk CG).
1559 uint delayed_size = _delayed_worklist.size();
1560 for( uint next = 0; next < delayed_size; ++next ) {
1561 Node* n = _delayed_worklist.at(next);
1562 build_connection_graph(n, igvn);
1563 }
1564
1565 // 3. Pass to create fields edges (Allocate -F-> AddP).
1566 uint cg_length = cg_worklist.length();
1567 for( uint next = 0; next < cg_length; ++next ) {
1568 int ni = cg_worklist.at(next);
1569 build_connection_graph(ptnode_adr(ni)->_node, igvn);
1570 }
1571
1572 cg_worklist.clear();
1573 cg_worklist.append(_phantom_object);
1574
1575 // 4. Build Connection Graph which need
1576 // to walk the connection graph.
1577 for (uint ni = 0; ni < nodes_size(); ni++) {
1578 PointsToNode* ptn = ptnode_adr(ni);
1579 Node *n = ptn->_node;
1580 if (n != NULL) { // Call, AddP, LoadP, StoreP
1581 build_connection_graph(n, igvn);
1582 if (ptn->node_type() != PointsToNode::UnknownType)
1583 cg_worklist.append(n->_idx); // Collect CG nodes
1584 }
1585 }
1586
1587 Arena* arena = Thread::current()->resource_area();
1588 VectorSet ptset(arena);
1589 GrowableArray<uint> deferred_edges;
1590 VectorSet visited(arena);
1591
1592 // 5. Remove deferred edges from the graph and adjust
1593 // escape state of nonescaping objects.
1594 cg_length = cg_worklist.length();
1595 for( uint next = 0; next < cg_length; ++next ) {
1596 int ni = cg_worklist.at(next);
1597 PointsToNode* ptn = ptnode_adr(ni);
1598 PointsToNode::NodeType nt = ptn->node_type();
1599 if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1600 remove_deferred(ni, &deferred_edges, &visited);
1601 Node *n = ptn->_node;
1602 if (n->is_AddP()) {
1603 // Search for objects which are not scalar replaceable
1604 // and adjust their escape state.
1605 verify_escape_state(ni, ptset, igvn);
1606 }
1607 }
1608 }
1609
1610 // 6. Propagate escape states.
1611 GrowableArray<int> worklist;
1612 bool has_non_escaping_obj = false;
1613
1614 // push all GlobalEscape nodes on the worklist
1615 for( uint next = 0; next < cg_length; ++next ) {
1616 int nk = cg_worklist.at(next);
1617 if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
1618 worklist.push(nk);
1619 }
1620 // mark all nodes reachable from GlobalEscape nodes
1621 while(worklist.length() > 0) {
1622 PointsToNode* ptn = ptnode_adr(worklist.pop());
1623 uint e_cnt = ptn->edge_count();
1624 for (uint ei = 0; ei < e_cnt; ei++) {
1625 uint npi = ptn->edge_target(ei);
1626 PointsToNode *np = ptnode_adr(npi);
1627 if (np->escape_state() < PointsToNode::GlobalEscape) {
1628 np->set_escape_state(PointsToNode::GlobalEscape);
1629 worklist.push(npi);
1630 }
1631 }
1632 }
1633
1634 // push all ArgEscape nodes on the worklist
1635 for( uint next = 0; next < cg_length; ++next ) {
1636 int nk = cg_worklist.at(next);
1637 if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
1638 worklist.push(nk);
1639 }
1640 // mark all nodes reachable from ArgEscape nodes
1641 while(worklist.length() > 0) {
1642 PointsToNode* ptn = ptnode_adr(worklist.pop());
1643 if (ptn->node_type() == PointsToNode::JavaObject)
1644 has_non_escaping_obj = true; // Non GlobalEscape
1645 uint e_cnt = ptn->edge_count();
1646 for (uint ei = 0; ei < e_cnt; ei++) {
1647 uint npi = ptn->edge_target(ei);
1648 PointsToNode *np = ptnode_adr(npi);
1649 if (np->escape_state() < PointsToNode::ArgEscape) {
1650 np->set_escape_state(PointsToNode::ArgEscape);
1651 worklist.push(npi);
1652 }
1653 }
1654 }
1655
1656 GrowableArray<Node*> alloc_worklist;
1657
1658 // push all NoEscape nodes on the worklist
1659 for( uint next = 0; next < cg_length; ++next ) {
1660 int nk = cg_worklist.at(next);
1661 if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1662 worklist.push(nk);
1663 }
1664 // mark all nodes reachable from NoEscape nodes
1665 while(worklist.length() > 0) {
1666 PointsToNode* ptn = ptnode_adr(worklist.pop());
1667 if (ptn->node_type() == PointsToNode::JavaObject)
1668 has_non_escaping_obj = true; // Non GlobalEscape
1669 Node* n = ptn->_node;
1670 if (n->is_Allocate() && ptn->_scalar_replaceable ) {
1671 // Push scalar replaceable allocations on alloc_worklist
1672 // for processing in split_unique_types().
1673 alloc_worklist.append(n);
1674 }
1675 uint e_cnt = ptn->edge_count();
1676 for (uint ei = 0; ei < e_cnt; ei++) {
1677 uint npi = ptn->edge_target(ei);
1678 PointsToNode *np = ptnode_adr(npi);
1679 if (np->escape_state() < PointsToNode::NoEscape) {
1680 np->set_escape_state(PointsToNode::NoEscape);
1681 worklist.push(npi);
1682 }
1683 }
1684 }
1685
1686 _collecting = false;
1687 assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1688
1689 #ifndef PRODUCT
1690 if (PrintEscapeAnalysis) {
1691 dump(); // Dump ConnectionGraph
1692 }
1693 #endif
1694
1695 bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1696 if ( has_scalar_replaceable_candidates &&
1697 C->AliasLevel() >= 3 && EliminateAllocations ) {
1698
1699 // Now use the escape information to create unique types for
1700 // scalar replaceable objects.
1701 split_unique_types(alloc_worklist);
1702
1703 if (C->failing()) return false;
1704
1705 C->print_method("After Escape Analysis", 2);
1706
1707 #ifdef ASSERT
1708 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1709 tty->print("=== No allocations eliminated for ");
1710 C->method()->print_short_name();
1711 if(!EliminateAllocations) {
1712 tty->print(" since EliminateAllocations is off ===");
1713 } else if(!has_scalar_replaceable_candidates) {
1714 tty->print(" since there are no scalar replaceable candidates ===");
1715 } else if(C->AliasLevel() < 3) {
1716 tty->print(" since AliasLevel < 3 ===");
1717 }
1718 tty->cr();
1719 #endif
1720 }
1721 return has_non_escaping_obj;
1722 }
1723
1724 // Search for objects which are not scalar replaceable.
1725 void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
1726 PointsToNode* ptn = ptnode_adr(nidx);
1727 Node* n = ptn->_node;
1728 assert(n->is_AddP(), "Should be called for AddP nodes only");
1729 // Search for objects which are not scalar replaceable.
1730 // Mark their escape state as ArgEscape to propagate the state
1731 // to referenced objects.
1732 // Note: currently there are no difference in compiler optimizations
1733 // for ArgEscape objects and NoEscape objects which are not
1734 // scalar replaceable.
1735
1736 Compile* C = _compile;
1737
1738 int offset = ptn->offset();
1739 Node* base = get_addp_base(n);
1740 ptset.Clear();
1741 PointsTo(ptset, base);
1742 int ptset_size = ptset.Size();
1743
1744 // Check if a oop field's initializing value is recorded and add
1745 // a corresponding NULL field's value if it is not recorded.
1746 // Connection Graph does not record a default initialization by NULL
1747 // captured by Initialize node.
1748 //
1749 // Note: it will disable scalar replacement in some cases:
1750 //
1751 // Point p[] = new Point[1];
1752 // p[0] = new Point(); // Will be not scalar replaced
1753 //
1754 // but it will save us from incorrect optimizations in next cases:
1755 //
1756 // Point p[] = new Point[1];
1757 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1758 //
1759 // Do a simple control flow analysis to distinguish above cases.
1760 //
1761 if (offset != Type::OffsetBot && ptset_size == 1) {
1762 uint elem = ptset.getelem(); // Allocation node's index
1763 // It does not matter if it is not Allocation node since
1764 // only non-escaping allocations are scalar replaced.
1765 if (ptnode_adr(elem)->_node->is_Allocate() &&
1766 ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
1767 AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
1768 InitializeNode* ini = alloc->initialization();
1769
1770 // Check only oop fields.
1771 const Type* adr_type = n->as_AddP()->bottom_type();
1772 BasicType basic_field_type = T_INT;
1773 if (adr_type->isa_instptr()) {
1774 ciField* field = C->alias_type(adr_type->isa_instptr())->field();
1775 if (field != NULL) {
1776 basic_field_type = field->layout_type();
1777 } else {
1778 // Ignore non field load (for example, klass load)
1779 }
1780 } else if (adr_type->isa_aryptr()) {
1781 const Type* elemtype = adr_type->isa_aryptr()->elem();
1782 basic_field_type = elemtype->array_element_basic_type();
1783 } else {
1784 // Raw pointers are used for initializing stores so skip it.
1785 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1786 (base->in(0) == alloc),"unexpected pointer type");
1787 }
1788 if (basic_field_type == T_OBJECT ||
1789 basic_field_type == T_NARROWOOP ||
1790 basic_field_type == T_ARRAY) {
1791 Node* value = NULL;
1792 if (ini != NULL) {
1793 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1794 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1795 if (store != NULL && store->is_Store()) {
1796 value = store->in(MemNode::ValueIn);
1797 } else if (ptn->edge_count() > 0) { // Are there oop stores?
1798 // Check for a store which follows allocation without branches.
1799 // For example, a volatile field store is not collected
1800 // by Initialize node. TODO: it would be nice to use idom() here.
1801 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1802 store = n->fast_out(i);
1803 if (store->is_Store() && store->in(0) != NULL) {
1804 Node* ctrl = store->in(0);
1805 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
1806 ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
1807 ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
1808 ctrl = ctrl->in(0);
1809 }
1810 if (ctrl == ini || ctrl == alloc) {
1811 value = store->in(MemNode::ValueIn);
1812 break;
1813 }
1814 }
1815 }
1816 }
1817 }
1818 if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1819 // A field's initializing value was not recorded. Add NULL.
1820 uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1821 add_pointsto_edge(nidx, null_idx);
1822 }
1823 }
1824 }
1825 }
1826
1827 // An object is not scalar replaceable if the field which may point
1828 // to it has unknown offset (unknown element of an array of objects).
1829 //
1830 if (offset == Type::OffsetBot) {
1831 uint e_cnt = ptn->edge_count();
1832 for (uint ei = 0; ei < e_cnt; ei++) {
1833 uint npi = ptn->edge_target(ei);
1834 set_escape_state(npi, PointsToNode::ArgEscape);
1835 ptnode_adr(npi)->_scalar_replaceable = false;
1836 }
1837 }
1838
1839 // Currently an object is not scalar replaceable if a LoadStore node
1840 // access its field since the field value is unknown after it.
1841 //
1842 bool has_LoadStore = false;
1843 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1844 Node *use = n->fast_out(i);
1845 if (use->is_LoadStore()) {
1846 has_LoadStore = true;
1847 break;
1848 }
1849 }
1850 // An object is not scalar replaceable if the address points
1851 // to unknown field (unknown element for arrays, offset is OffsetBot).
1852 //
1853 // Or the address may point to more then one object. This may produce
1854 // the false positive result (set scalar_replaceable to false)
1855 // since the flow-insensitive escape analysis can't separate
1856 // the case when stores overwrite the field's value from the case
1857 // when stores happened on different control branches.
1858 //
1859 if (ptset_size > 1 || ptset_size != 0 &&
1860 (has_LoadStore || offset == Type::OffsetBot)) {
1861 for( VectorSetI j(&ptset); j.test(); ++j ) {
1862 set_escape_state(j.elem, PointsToNode::ArgEscape);
1863 ptnode_adr(j.elem)->_scalar_replaceable = false;
1864 }
1865 }
1866 }
1867
1868 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1869
1870 switch (call->Opcode()) {
1871 #ifdef ASSERT
1872 case Op_Allocate:
1873 case Op_AllocateArray:
1874 case Op_Lock:
1875 case Op_Unlock:
1876 assert(false, "should be done already");
1877 break;
1878 #endif
1879 case Op_CallLeaf:
1880 case Op_CallLeafNoFP:
1881 {
1882 // Stub calls, objects do not escape but they are not scale replaceable.
1883 // Adjust escape state for outgoing arguments.
1884 const TypeTuple * d = call->tf()->domain();
1885 VectorSet ptset(Thread::current()->resource_area());
1886 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1887 const Type* at = d->field_at(i);
1888 Node *arg = call->in(i)->uncast();
1889 const Type *aat = phase->type(arg);
1890 if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
1891 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
1892
1893 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1894 aat->isa_ptr() != NULL, "expecting an Ptr");
1895 #ifdef ASSERT
1896 if (!(call->Opcode() == Op_CallLeafNoFP &&
1897 call->as_CallLeaf()->_name != NULL &&
1898 (strstr(call->as_CallLeaf()->_name, "arraycopy") != 0) ||
1899 call->as_CallLeaf()->_name != NULL &&
1900 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
1901 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
1902 ) {
1903 call->dump();
1904 assert(false, "EA: unexpected CallLeaf");
1905 }
1906 #endif
1907 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1908 if (arg->is_AddP()) {
1909 //
1910 // The inline_native_clone() case when the arraycopy stub is called
1911 // after the allocation before Initialize and CheckCastPP nodes.
1912 //
1913 // Set AddP's base (Allocate) as not scalar replaceable since
1914 // pointer to the base (with offset) is passed as argument.
1915 //
1916 arg = get_addp_base(arg);
1917 }
1918 ptset.Clear();
1919 PointsTo(ptset, arg);
1920 for( VectorSetI j(&ptset); j.test(); ++j ) {
1921 uint pt = j.elem;
1922 set_escape_state(pt, PointsToNode::ArgEscape);
1923 }
1924 }
1925 }
1926 break;
1927 }
1928
1929 case Op_CallStaticJava:
1930 // For a static call, we know exactly what method is being called.
1931 // Use bytecode estimator to record the call's escape affects
1932 {
1933 ciMethod *meth = call->as_CallJava()->method();
1934 BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1935 // fall-through if not a Java method or no analyzer information
1936 if (call_analyzer != NULL) {
1937 const TypeTuple * d = call->tf()->domain();
1938 VectorSet ptset(Thread::current()->resource_area());
1939 bool copy_dependencies = false;
1940 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1941 const Type* at = d->field_at(i);
1942 int k = i - TypeFunc::Parms;
1943 Node *arg = call->in(i)->uncast();
1944
1945 if (at->isa_oopptr() != NULL &&
1946 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
1947
1948 bool global_escapes = false;
1949 bool fields_escapes = false;
1950 if (!call_analyzer->is_arg_stack(k)) {
1951 // The argument global escapes, mark everything it could point to
1952 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1953 global_escapes = true;
1954 } else {
1955 if (!call_analyzer->is_arg_local(k)) {
1956 // The argument itself doesn't escape, but any fields might
1957 fields_escapes = true;
1958 }
1959 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1960 copy_dependencies = true;
1961 }
1962
1963 ptset.Clear();
1964 PointsTo(ptset, arg);
1965 for( VectorSetI j(&ptset); j.test(); ++j ) {
1966 uint pt = j.elem;
1967 if (global_escapes) {
1968 //The argument global escapes, mark everything it could point to
1969 set_escape_state(pt, PointsToNode::GlobalEscape);
1970 } else {
1971 if (fields_escapes) {
1972 // The argument itself doesn't escape, but any fields might
1973 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
1974 }
1975 set_escape_state(pt, PointsToNode::ArgEscape);
1976 }
1977 }
1978 }
1979 }
1980 if (copy_dependencies)
1981 call_analyzer->copy_dependencies(_compile->dependencies());
1982 break;
1983 }
1984 }
1985
1986 default:
1987 // Fall-through here if not a Java method or no analyzer information
1988 // or some other type of call, assume the worst case: all arguments
1989 // globally escape.
1990 {
1991 // adjust escape state for outgoing arguments
1992 const TypeTuple * d = call->tf()->domain();
1993 VectorSet ptset(Thread::current()->resource_area());
1994 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1995 const Type* at = d->field_at(i);
1996 if (at->isa_oopptr() != NULL) {
1997 Node *arg = call->in(i)->uncast();
1998 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1999 ptset.Clear();
2000 PointsTo(ptset, arg);
2001 for( VectorSetI j(&ptset); j.test(); ++j ) {
2002 uint pt = j.elem;
2003 set_escape_state(pt, PointsToNode::GlobalEscape);
2004 }
2005 }
2006 }
2007 }
2008 }
2009 }
2010 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
2011 CallNode *call = resproj->in(0)->as_Call();
2012 uint call_idx = call->_idx;
2013 uint resproj_idx = resproj->_idx;
2014
2015 switch (call->Opcode()) {
2016 case Op_Allocate:
2017 {
2018 Node *k = call->in(AllocateNode::KlassNode);
2019 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2020 assert(kt != NULL, "TypeKlassPtr required.");
2021 ciKlass* cik = kt->klass();
2022
2023 PointsToNode::EscapeState es;
2024 uint edge_to;
2025 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2026 !cik->is_instance_klass() || // StressReflectiveCode
2027 cik->as_instance_klass()->has_finalizer()) {
2028 es = PointsToNode::GlobalEscape;
2029 edge_to = _phantom_object; // Could not be worse
2030 } else {
2031 es = PointsToNode::NoEscape;
2032 edge_to = call_idx;
2033 }
2034 set_escape_state(call_idx, es);
2035 add_pointsto_edge(resproj_idx, edge_to);
2036 _processed.set(resproj_idx);
2037 break;
2038 }
2039
2040 case Op_AllocateArray:
2041 {
2042
2043 Node *k = call->in(AllocateNode::KlassNode);
2044 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2045 assert(kt != NULL, "TypeKlassPtr required.");
2046 ciKlass* cik = kt->klass();
2047
2048 PointsToNode::EscapeState es;
2049 uint edge_to;
2050 if (!cik->is_array_klass()) { // StressReflectiveCode
2051 es = PointsToNode::GlobalEscape;
2052 edge_to = _phantom_object;
2053 } else {
2054 es = PointsToNode::NoEscape;
2055 edge_to = call_idx;
2056 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2057 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2058 // Not scalar replaceable if the length is not constant or too big.
2059 ptnode_adr(call_idx)->_scalar_replaceable = false;
2060 }
2061 }
2062 set_escape_state(call_idx, es);
2063 add_pointsto_edge(resproj_idx, edge_to);
2064 _processed.set(resproj_idx);
2065 break;
2066 }
2067
2068 case Op_CallStaticJava:
2069 // For a static call, we know exactly what method is being called.
2070 // Use bytecode estimator to record whether the call's return value escapes
2071 {
2072 bool done = true;
2073 const TypeTuple *r = call->tf()->range();
2074 const Type* ret_type = NULL;
2075
2076 if (r->cnt() > TypeFunc::Parms)
2077 ret_type = r->field_at(TypeFunc::Parms);
2078
2079 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2080 // _multianewarray functions return a TypeRawPtr.
2081 if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2082 _processed.set(resproj_idx);
2083 break; // doesn't return a pointer type
2084 }
2085 ciMethod *meth = call->as_CallJava()->method();
2086 const TypeTuple * d = call->tf()->domain();
2087 if (meth == NULL) {
2088 // not a Java method, assume global escape
2089 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2090 add_pointsto_edge(resproj_idx, _phantom_object);
2091 } else {
2092 BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2093 bool copy_dependencies = false;
2094
2095 if (call_analyzer->is_return_allocated()) {
2096 // Returns a newly allocated unescaped object, simply
2097 // update dependency information.
2098 // Mark it as NoEscape so that objects referenced by
2099 // it's fields will be marked as NoEscape at least.
2100 set_escape_state(call_idx, PointsToNode::NoEscape);
2101 add_pointsto_edge(resproj_idx, call_idx);
2102 copy_dependencies = true;
2103 } else if (call_analyzer->is_return_local()) {
2104 // determine whether any arguments are returned
2105 set_escape_state(call_idx, PointsToNode::NoEscape);
2106 bool ret_arg = false;
2107 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2108 const Type* at = d->field_at(i);
2109
2110 if (at->isa_oopptr() != NULL) {
2111 Node *arg = call->in(i)->uncast();
2112
2113 if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2114 ret_arg = true;
2115 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2116 if (arg_esp->node_type() == PointsToNode::UnknownType)
2117 done = false;
2118 else if (arg_esp->node_type() == PointsToNode::JavaObject)
2119 add_pointsto_edge(resproj_idx, arg->_idx);
2120 else
2121 add_deferred_edge(resproj_idx, arg->_idx);
2122 arg_esp->_hidden_alias = true;
2123 }
2124 }
2125 }
2126 if (done && !ret_arg) {
2127 // Returns unknown object.
2128 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2129 add_pointsto_edge(resproj_idx, _phantom_object);
2130 }
2131 copy_dependencies = true;
2132 } else {
2133 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2134 add_pointsto_edge(resproj_idx, _phantom_object);
2135 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2136 const Type* at = d->field_at(i);
2137 if (at->isa_oopptr() != NULL) {
2138 Node *arg = call->in(i)->uncast();
2139 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2140 arg_esp->_hidden_alias = true;
2141 }
2142 }
2143 }
2144 if (copy_dependencies)
2145 call_analyzer->copy_dependencies(_compile->dependencies());
2146 }
2147 if (done)
2148 _processed.set(resproj_idx);
2149 break;
2150 }
2151
2152 default:
2153 // Some other type of call, assume the worst case that the
2154 // returned value, if any, globally escapes.
2155 {
2156 const TypeTuple *r = call->tf()->range();
2157 if (r->cnt() > TypeFunc::Parms) {
2158 const Type* ret_type = r->field_at(TypeFunc::Parms);
2159
2160 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2161 // _multianewarray functions return a TypeRawPtr.
2162 if (ret_type->isa_ptr() != NULL) {
2163 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2164 add_pointsto_edge(resproj_idx, _phantom_object);
2165 }
2166 }
2167 _processed.set(resproj_idx);
2168 }
2169 }
2170 }
2171
2172 // Populate Connection Graph with Ideal nodes and create simple
2173 // connection graph edges (do not need to check the node_type of inputs
2174 // or to call PointsTo() to walk the connection graph).
2175 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2176 if (_processed.test(n->_idx))
2177 return; // No need to redefine node's state.
2178
2179 if (n->is_Call()) {
2180 // Arguments to allocation and locking don't escape.
2181 if (n->is_Allocate()) {
2182 add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2183 record_for_optimizer(n);
2184 } else if (n->is_Lock() || n->is_Unlock()) {
2185 // Put Lock and Unlock nodes on IGVN worklist to process them during
2186 // the first IGVN optimization when escape information is still available.
2187 record_for_optimizer(n);
2188 _processed.set(n->_idx);
2189 } else {
2190 // Don't mark as processed since call's arguments have to be processed.
2191 PointsToNode::NodeType nt = PointsToNode::UnknownType;
2192 PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2193
2194 // Check if a call returns an object.
2195 const TypeTuple *r = n->as_Call()->tf()->range();
2196 if (r->cnt() > TypeFunc::Parms &&
2197 r->field_at(TypeFunc::Parms)->isa_ptr() &&
2198 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2199 nt = PointsToNode::JavaObject;
2200 if (!n->is_CallStaticJava()) {
2201 // Since the called mathod is statically unknown assume
2202 // the worst case that the returned value globally escapes.
2203 es = PointsToNode::GlobalEscape;
2204 }
2205 }
2206 add_node(n, nt, es, false);
2207 }
2208 return;
2209 }
2210
2211 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2212 // ThreadLocal has RawPrt type.
2213 switch (n->Opcode()) {
2214 case Op_AddP:
2215 {
2216 add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
2217 break;
2218 }
2219 case Op_CastX2P:
2220 { // "Unsafe" memory access.
2221 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2222 break;
2223 }
2224 case Op_CastPP:
2225 case Op_CheckCastPP:
2226 case Op_EncodeP:
2227 case Op_DecodeN:
2228 {
2229 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2230 int ti = n->in(1)->_idx;
2231 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2232 if (nt == PointsToNode::UnknownType) {
2233 _delayed_worklist.push(n); // Process it later.
2234 break;
2235 } else if (nt == PointsToNode::JavaObject) {
2236 add_pointsto_edge(n->_idx, ti);
2237 } else {
2238 add_deferred_edge(n->_idx, ti);
2239 }
2240 _processed.set(n->_idx);
2241 break;
2242 }
2243 case Op_ConP:
2244 {
2245 // assume all pointer constants globally escape except for null
2246 PointsToNode::EscapeState es;
2247 if (phase->type(n) == TypePtr::NULL_PTR)
2248 es = PointsToNode::NoEscape;
2249 else
2250 es = PointsToNode::GlobalEscape;
2251
2252 add_node(n, PointsToNode::JavaObject, es, true);
2253 break;
2254 }
2255 case Op_ConN:
2256 {
2257 // assume all narrow oop constants globally escape except for null
2258 PointsToNode::EscapeState es;
2259 if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2260 es = PointsToNode::NoEscape;
2261 else
2262 es = PointsToNode::GlobalEscape;
2263
2264 add_node(n, PointsToNode::JavaObject, es, true);
2265 break;
2266 }
2267 case Op_CreateEx:
2268 {
2269 // assume that all exception objects globally escape
2270 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2271 break;
2272 }
2273 case Op_LoadKlass:
2274 case Op_LoadNKlass:
2275 {
2276 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2277 break;
2278 }
2279 case Op_LoadP:
2280 case Op_LoadN:
2281 {
2282 const Type *t = phase->type(n);
2283 if (t->make_ptr() == NULL) {
2284 _processed.set(n->_idx);
2285 return;
2286 }
2287 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2288 break;
2289 }
2290 case Op_Parm:
2291 {
2292 _processed.set(n->_idx); // No need to redefine it state.
2293 uint con = n->as_Proj()->_con;
2294 if (con < TypeFunc::Parms)
2295 return;
2296 const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2297 if (t->isa_ptr() == NULL)
2298 return;
2299 // We have to assume all input parameters globally escape
2300 // (Note: passing 'false' since _processed is already set).
2301 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2302 break;
2303 }
2304 case Op_Phi:
2305 {
2306 const Type *t = n->as_Phi()->type();
2307 if (t->make_ptr() == NULL) {
2308 // nothing to do if not an oop or narrow oop
2309 _processed.set(n->_idx);
2310 return;
2311 }
2312 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2313 uint i;
2314 for (i = 1; i < n->req() ; i++) {
2315 Node* in = n->in(i);
2316 if (in == NULL)
2317 continue; // ignore NULL
2318 in = in->uncast();
2319 if (in->is_top() || in == n)
2320 continue; // ignore top or inputs which go back this node
2321 int ti = in->_idx;
2322 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2323 if (nt == PointsToNode::UnknownType) {
2324 break;
2325 } else if (nt == PointsToNode::JavaObject) {
2326 add_pointsto_edge(n->_idx, ti);
2327 } else {
2328 add_deferred_edge(n->_idx, ti);
2329 }
2330 }
2331 if (i >= n->req())
2332 _processed.set(n->_idx);
2333 else
2334 _delayed_worklist.push(n);
2335 break;
2336 }
2337 case Op_Proj:
2338 {
2339 // we are only interested in the oop result projection from a call
2340 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2341 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2342 assert(r->cnt() > TypeFunc::Parms, "sanity");
2343 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2344 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2345 int ti = n->in(0)->_idx;
2346 // The call may not be registered yet (since not all its inputs are registered)
2347 // if this is the projection from backbranch edge of Phi.
2348 if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2349 process_call_result(n->as_Proj(), phase);
2350 }
2351 if (!_processed.test(n->_idx)) {
2352 // The call's result may need to be processed later if the call
2353 // returns it's argument and the argument is not processed yet.
2354 _delayed_worklist.push(n);
2355 }
2356 break;
2357 }
2358 }
2359 _processed.set(n->_idx);
2360 break;
2361 }
2362 case Op_Return:
2363 {
2364 if( n->req() > TypeFunc::Parms &&
2365 phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2366 // Treat Return value as LocalVar with GlobalEscape escape state.
2367 add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2368 int ti = n->in(TypeFunc::Parms)->_idx;
2369 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2370 if (nt == PointsToNode::UnknownType) {
2371 _delayed_worklist.push(n); // Process it later.
2372 break;
2373 } else if (nt == PointsToNode::JavaObject) {
2374 add_pointsto_edge(n->_idx, ti);
2375 } else {
2376 add_deferred_edge(n->_idx, ti);
2377 }
2378 }
2379 _processed.set(n->_idx);
2380 break;
2381 }
2382 case Op_StoreP:
2383 case Op_StoreN:
2384 {
2385 const Type *adr_type = phase->type(n->in(MemNode::Address));
2386 adr_type = adr_type->make_ptr();
2387 if (adr_type->isa_oopptr()) {
2388 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2389 } else {
2390 Node* adr = n->in(MemNode::Address);
2391 if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2392 adr->in(AddPNode::Address)->is_Proj() &&
2393 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2394 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2395 // We are computing a raw address for a store captured
2396 // by an Initialize compute an appropriate address type.
2397 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2398 assert(offs != Type::OffsetBot, "offset must be a constant");
2399 } else {
2400 _processed.set(n->_idx);
2401 return;
2402 }
2403 }
2404 break;
2405 }
2406 case Op_StorePConditional:
2407 case Op_CompareAndSwapP:
2408 case Op_CompareAndSwapN:
2409 {
2410 const Type *adr_type = phase->type(n->in(MemNode::Address));
2411 adr_type = adr_type->make_ptr();
2412 if (adr_type->isa_oopptr()) {
2413 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2414 } else {
2415 _processed.set(n->_idx);
2416 return;
2417 }
2418 break;
2419 }
2420 case Op_AryEq:
2421 case Op_StrComp:
2422 case Op_StrEquals:
2423 case Op_StrIndexOf:
2424 {
2425 // char[] arrays passed to string intrinsics are not scalar replaceable.
2426 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2427 break;
2428 }
2429 case Op_ThreadLocal:
2430 {
2431 add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2432 break;
2433 }
2434 default:
2435 ;
2436 // nothing to do
2437 }
2438 return;
2439 }
2440
2441 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2442 uint n_idx = n->_idx;
2443 assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2444
2445 // Don't set processed bit for AddP, LoadP, StoreP since
2446 // they may need more then one pass to process.
2447 if (_processed.test(n_idx))
2448 return; // No need to redefine node's state.
2449
2450 if (n->is_Call()) {
2451 CallNode *call = n->as_Call();
2452 process_call_arguments(call, phase);
2453 _processed.set(n_idx);
2454 return;
2455 }
2456
2457 switch (n->Opcode()) {
2458 case Op_AddP:
2459 {
2460 Node *base = get_addp_base(n);
2461 // Create a field edge to this node from everything base could point to.
2462 VectorSet ptset(Thread::current()->resource_area());
2463 PointsTo(ptset, base);
2464 for( VectorSetI i(&ptset); i.test(); ++i ) {
2465 uint pt = i.elem;
2466 add_field_edge(pt, n_idx, address_offset(n, phase));
2467 }
2468 break;
2469 }
2470 case Op_CastX2P:
2471 {
2472 assert(false, "Op_CastX2P");
2473 break;
2474 }
2475 case Op_CastPP:
2476 case Op_CheckCastPP:
2477 case Op_EncodeP:
2478 case Op_DecodeN:
2479 {
2480 int ti = n->in(1)->_idx;
2481 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2482 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2483 add_pointsto_edge(n_idx, ti);
2484 } else {
2485 add_deferred_edge(n_idx, ti);
2486 }
2487 _processed.set(n_idx);
2488 break;
2489 }
2490 case Op_ConP:
2491 {
2492 assert(false, "Op_ConP");
2493 break;
2494 }
2495 case Op_ConN:
2496 {
2497 assert(false, "Op_ConN");
2498 break;
2499 }
2500 case Op_CreateEx:
2501 {
2502 assert(false, "Op_CreateEx");
2503 break;
2504 }
2505 case Op_LoadKlass:
2506 case Op_LoadNKlass:
2507 {
2508 assert(false, "Op_LoadKlass");
2509 break;
2510 }
2511 case Op_LoadP:
2512 case Op_LoadN:
2513 {
2514 const Type *t = phase->type(n);
2515 #ifdef ASSERT
2516 if (t->make_ptr() == NULL)
2517 assert(false, "Op_LoadP");
2518 #endif
2519
2520 Node* adr = n->in(MemNode::Address)->uncast();
2521 Node* adr_base;
2522 if (adr->is_AddP()) {
2523 adr_base = get_addp_base(adr);
2524 } else {
2525 adr_base = adr;
2526 }
2527
2528 // For everything "adr_base" could point to, create a deferred edge from
2529 // this node to each field with the same offset.
2530 VectorSet ptset(Thread::current()->resource_area());
2531 PointsTo(ptset, adr_base);
2532 int offset = address_offset(adr, phase);
2533 for( VectorSetI i(&ptset); i.test(); ++i ) {
2534 uint pt = i.elem;
2535 add_deferred_edge_to_fields(n_idx, pt, offset);
2536 }
2537 break;
2538 }
2539 case Op_Parm:
2540 {
2541 assert(false, "Op_Parm");
2542 break;
2543 }
2544 case Op_Phi:
2545 {
2546 #ifdef ASSERT
2547 const Type *t = n->as_Phi()->type();
2548 if (t->make_ptr() == NULL)
2549 assert(false, "Op_Phi");
2550 #endif
2551 for (uint i = 1; i < n->req() ; i++) {
2552 Node* in = n->in(i);
2553 if (in == NULL)
2554 continue; // ignore NULL
2555 in = in->uncast();
2556 if (in->is_top() || in == n)
2557 continue; // ignore top or inputs which go back this node
2558 int ti = in->_idx;
2559 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2560 assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2561 if (nt == PointsToNode::JavaObject) {
2562 add_pointsto_edge(n_idx, ti);
2563 } else {
2564 add_deferred_edge(n_idx, ti);
2565 }
2566 }
2567 _processed.set(n_idx);
2568 break;
2569 }
2570 case Op_Proj:
2571 {
2572 // we are only interested in the oop result projection from a call
2573 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2574 assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
2575 "all nodes should be registered");
2576 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2577 assert(r->cnt() > TypeFunc::Parms, "sanity");
2578 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2579 process_call_result(n->as_Proj(), phase);
2580 assert(_processed.test(n_idx), "all call results should be processed");
2581 break;
2582 }
2583 }
2584 assert(false, "Op_Proj");
2585 break;
2586 }
2587 case Op_Return:
2588 {
2589 #ifdef ASSERT
2590 if( n->req() <= TypeFunc::Parms ||
2591 !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2592 assert(false, "Op_Return");
2593 }
2594 #endif
2595 int ti = n->in(TypeFunc::Parms)->_idx;
2596 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
2597 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2598 add_pointsto_edge(n_idx, ti);
2599 } else {
2600 add_deferred_edge(n_idx, ti);
2601 }
2602 _processed.set(n_idx);
2603 break;
2604 }
2605 case Op_StoreP:
2606 case Op_StoreN:
2607 case Op_StorePConditional:
2608 case Op_CompareAndSwapP:
2609 case Op_CompareAndSwapN:
2610 {
2611 Node *adr = n->in(MemNode::Address);
2612 const Type *adr_type = phase->type(adr)->make_ptr();
2613 #ifdef ASSERT
2614 if (!adr_type->isa_oopptr())
2615 assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2616 #endif
2617
2618 assert(adr->is_AddP(), "expecting an AddP");
2619 Node *adr_base = get_addp_base(adr);
2620 Node *val = n->in(MemNode::ValueIn)->uncast();
2621 // For everything "adr_base" could point to, create a deferred edge
2622 // to "val" from each field with the same offset.
2623 VectorSet ptset(Thread::current()->resource_area());
2624 PointsTo(ptset, adr_base);
2625 for( VectorSetI i(&ptset); i.test(); ++i ) {
2626 uint pt = i.elem;
2627 add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2628 }
2629 break;
2630 }
2631 case Op_AryEq:
2632 case Op_StrComp:
2633 case Op_StrEquals:
2634 case Op_StrIndexOf:
2635 {
2636 // char[] arrays passed to string intrinsic do not escape but
2637 // they are not scalar replaceable. Adjust escape state for them.
2638 // Start from in(2) edge since in(1) is memory edge.
2639 for (uint i = 2; i < n->req(); i++) {
2640 Node* adr = n->in(i)->uncast();
2641 const Type *at = phase->type(adr);
2642 if (!adr->is_top() && at->isa_ptr()) {
2643 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
2644 at->isa_ptr() != NULL, "expecting an Ptr");
2645 if (adr->is_AddP()) {
2646 adr = get_addp_base(adr);
2647 }
2648 // Mark as ArgEscape everything "adr" could point to.
2649 set_escape_state(adr->_idx, PointsToNode::ArgEscape);
2650 }
2651 }
2652 _processed.set(n_idx);
2653 break;
2654 }
2655 case Op_ThreadLocal:
2656 {
2657 assert(false, "Op_ThreadLocal");
2658 break;
2659 }
2660 default:
2661 // This method should be called only for EA specific nodes.
2662 ShouldNotReachHere();
2663 }
2664 }
2665
2666 #ifndef PRODUCT
2667 void ConnectionGraph::dump() {
2668 bool first = true;
2669
2670 uint size = nodes_size();
2671 for (uint ni = 0; ni < size; ni++) {
2672 PointsToNode *ptn = ptnode_adr(ni);
2673 PointsToNode::NodeType ptn_type = ptn->node_type();
2674
2675 if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2676 continue;
2677 PointsToNode::EscapeState es = escape_state(ptn->_node);
2678 if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2679 if (first) {
2680 tty->cr();
2681 tty->print("======== Connection graph for ");
2682 _compile->method()->print_short_name();
2683 tty->cr();
2684 first = false;
2685 }
2686 tty->print("%6d ", ni);
2687 ptn->dump();
2688 // Print all locals which reference this allocation
2689 for (uint li = ni; li < size; li++) {
2690 PointsToNode *ptn_loc = ptnode_adr(li);
2691 PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2692 if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2693 ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2694 ptnode_adr(li)->dump(false);
2695 }
2696 }
2697 if (Verbose) {
2698 // Print all fields which reference this allocation
2699 for (uint i = 0; i < ptn->edge_count(); i++) {
2700 uint ei = ptn->edge_target(i);
2701 ptnode_adr(ei)->dump(false);
2702 }
2703 }
2704 tty->cr();
2705 }
2706 }
2707 }
2708 #endif