1 /*
2 * Copyright 2005-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any 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) :
85 _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
86 _processed(C->comp_arena()),
87 _collecting(true),
88 _compile(C),
89 _node_map(C->comp_arena()) {
90
91 _phantom_object = C->top()->_idx,
92 add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
93
94 // Add ConP(#NULL) and ConN(#NULL) nodes.
95 PhaseGVN* igvn = C->initial_gvn();
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, PhaseTransform *phase) {
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 // compute max escape state of anything this node could point to
211 VectorSet ptset(Thread::current()->resource_area());
212 PointsTo(ptset, n, phase);
213 for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
214 uint pt = i.elem;
215 PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
216 if (pes > es)
217 es = pes;
218 }
219 // cache the computed escape state
220 assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
221 ptnode_adr(idx)->set_escape_state(es);
222 return es;
223 }
224
225 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n, PhaseTransform *phase) {
226 VectorSet visited(Thread::current()->resource_area());
227 GrowableArray<uint> worklist;
228
229 #ifdef ASSERT
230 Node *orig_n = n;
231 #endif
232
233 n = n->uncast();
234 PointsToNode* npt = ptnode_adr(n->_idx);
235
236 // If we have a JavaObject, return just that object
237 if (npt->node_type() == PointsToNode::JavaObject) {
238 ptset.set(n->_idx);
239 return;
240 }
241 #ifdef ASSERT
242 if (npt->_node == NULL) {
243 if (orig_n != n)
244 orig_n->dump();
245 n->dump();
246 assert(npt->_node != NULL, "unregistered node");
247 }
248 #endif
249 worklist.push(n->_idx);
250 while(worklist.length() > 0) {
251 int ni = worklist.pop();
252 if (visited.test_set(ni))
253 continue;
254
255 PointsToNode* pn = ptnode_adr(ni);
256 // ensure that all inputs of a Phi have been processed
257 assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
258
259 int edges_processed = 0;
260 uint e_cnt = pn->edge_count();
261 for (uint e = 0; e < e_cnt; e++) {
262 uint etgt = pn->edge_target(e);
263 PointsToNode::EdgeType et = pn->edge_type(e);
264 if (et == PointsToNode::PointsToEdge) {
265 ptset.set(etgt);
266 edges_processed++;
267 } else if (et == PointsToNode::DeferredEdge) {
268 worklist.push(etgt);
269 edges_processed++;
270 } else {
271 assert(false,"neither PointsToEdge or DeferredEdge");
272 }
273 }
274 if (edges_processed == 0) {
275 // no deferred or pointsto edges found. Assume the value was set
276 // outside this method. Add the phantom object to the pointsto set.
277 ptset.set(_phantom_object);
278 }
279 }
280 }
281
282 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
283 // This method is most expensive during ConnectionGraph construction.
284 // Reuse vectorSet and an additional growable array for deferred edges.
285 deferred_edges->clear();
286 visited->Clear();
287
288 visited->set(ni);
289 PointsToNode *ptn = ptnode_adr(ni);
290
291 // Mark current edges as visited and move deferred edges to separate array.
292 for (uint i = 0; i < ptn->edge_count(); ) {
293 uint t = ptn->edge_target(i);
294 #ifdef ASSERT
295 assert(!visited->test_set(t), "expecting no duplications");
296 #else
297 visited->set(t);
298 #endif
299 if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
300 ptn->remove_edge(t, PointsToNode::DeferredEdge);
301 deferred_edges->append(t);
302 } else {
303 i++;
304 }
305 }
306 for (int next = 0; next < deferred_edges->length(); ++next) {
307 uint t = deferred_edges->at(next);
308 PointsToNode *ptt = ptnode_adr(t);
309 uint e_cnt = ptt->edge_count();
310 for (uint e = 0; e < e_cnt; e++) {
311 uint etgt = ptt->edge_target(e);
312 if (visited->test_set(etgt))
313 continue;
314
315 PointsToNode::EdgeType et = ptt->edge_type(e);
316 if (et == PointsToNode::PointsToEdge) {
317 add_pointsto_edge(ni, etgt);
318 if(etgt == _phantom_object) {
319 // Special case - field set outside (globally escaping).
320 ptn->set_escape_state(PointsToNode::GlobalEscape);
321 }
322 } else if (et == PointsToNode::DeferredEdge) {
323 deferred_edges->append(etgt);
324 } else {
325 assert(false,"invalid connection graph");
326 }
327 }
328 }
329 }
330
331
332 // Add an edge to node given by "to_i" from any field of adr_i whose offset
333 // matches "offset" A deferred edge is added if to_i is a LocalVar, and
334 // a pointsto edge is added if it is a JavaObject
335
336 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
337 PointsToNode* an = ptnode_adr(adr_i);
338 PointsToNode* to = ptnode_adr(to_i);
339 bool deferred = (to->node_type() == PointsToNode::LocalVar);
340
341 for (uint fe = 0; fe < an->edge_count(); fe++) {
342 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
343 int fi = an->edge_target(fe);
344 PointsToNode* pf = ptnode_adr(fi);
345 int po = pf->offset();
346 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
347 if (deferred)
348 add_deferred_edge(fi, to_i);
349 else
350 add_pointsto_edge(fi, to_i);
351 }
352 }
353 }
354
355 // Add a deferred edge from node given by "from_i" to any field of adr_i
356 // whose offset matches "offset".
357 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
358 PointsToNode* an = ptnode_adr(adr_i);
359 for (uint fe = 0; fe < an->edge_count(); fe++) {
360 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
361 int fi = an->edge_target(fe);
362 PointsToNode* pf = ptnode_adr(fi);
363 int po = pf->offset();
364 if (pf->edge_count() == 0) {
365 // we have not seen any stores to this field, assume it was set outside this method
366 add_pointsto_edge(fi, _phantom_object);
367 }
368 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
369 add_deferred_edge(from_i, fi);
370 }
371 }
372 }
373
374 // Helper functions
375
376 static Node* get_addp_base(Node *addp) {
377 assert(addp->is_AddP(), "must be AddP");
378 //
379 // AddP cases for Base and Address inputs:
380 // case #1. Direct object's field reference:
381 // Allocate
382 // |
383 // Proj #5 ( oop result )
384 // |
385 // CheckCastPP (cast to instance type)
386 // | |
387 // AddP ( base == address )
388 //
389 // case #2. Indirect object's field reference:
390 // Phi
391 // |
392 // CastPP (cast to instance type)
393 // | |
394 // AddP ( base == address )
395 //
396 // case #3. Raw object's field reference for Initialize node:
397 // Allocate
398 // |
399 // Proj #5 ( oop result )
400 // top |
401 // \ |
402 // AddP ( base == top )
403 //
404 // case #4. Array's element reference:
405 // {CheckCastPP | CastPP}
406 // | | |
407 // | AddP ( array's element offset )
408 // | |
409 // AddP ( array's offset )
410 //
411 // case #5. Raw object's field reference for arraycopy stub call:
412 // The inline_native_clone() case when the arraycopy stub is called
413 // after the allocation before Initialize and CheckCastPP nodes.
414 // Allocate
415 // |
416 // Proj #5 ( oop result )
417 // | |
418 // AddP ( base == address )
419 //
420 // case #6. Constant Pool, ThreadLocal, CastX2P or
421 // Raw object's field reference:
422 // {ConP, ThreadLocal, CastX2P, raw Load}
423 // top |
424 // \ |
425 // AddP ( base == top )
426 //
427 // case #7. Klass's field reference.
428 // LoadKlass
429 // | |
430 // AddP ( base == address )
431 //
432 // case #8. narrow Klass's field reference.
433 // LoadNKlass
434 // |
435 // DecodeN
436 // | |
437 // AddP ( base == address )
438 //
439 Node *base = addp->in(AddPNode::Base)->uncast();
440 if (base->is_top()) { // The AddP case #3 and #6.
441 base = addp->in(AddPNode::Address)->uncast();
442 assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
443 base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
444 (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
445 (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
446 }
447 return base;
448 }
449
450 static Node* find_second_addp(Node* addp, Node* n) {
451 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
452
453 Node* addp2 = addp->raw_out(0);
454 if (addp->outcnt() == 1 && addp2->is_AddP() &&
455 addp2->in(AddPNode::Base) == n &&
456 addp2->in(AddPNode::Address) == addp) {
457
458 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
459 //
460 // Find array's offset to push it on worklist first and
461 // as result process an array's element offset first (pushed second)
462 // to avoid CastPP for the array's offset.
463 // Otherwise the inserted CastPP (LocalVar) will point to what
464 // the AddP (Field) points to. Which would be wrong since
465 // the algorithm expects the CastPP has the same point as
466 // as AddP's base CheckCastPP (LocalVar).
467 //
468 // ArrayAllocation
469 // |
470 // CheckCastPP
471 // |
472 // memProj (from ArrayAllocation CheckCastPP)
473 // | ||
474 // | || Int (element index)
475 // | || | ConI (log(element size))
476 // | || | /
477 // | || LShift
478 // | || /
479 // | AddP (array's element offset)
480 // | |
481 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
482 // | / /
483 // AddP (array's offset)
484 // |
485 // Load/Store (memory operation on array's element)
486 //
487 return addp2;
488 }
489 return NULL;
490 }
491
492 //
493 // Adjust the type and inputs of an AddP which computes the
494 // address of a field of an instance
495 //
496 bool ConnectionGraph::split_AddP(Node *addp, Node *base, PhaseGVN *igvn) {
497 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
498 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
499 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
500 if (t == NULL) {
501 // We are computing a raw address for a store captured by an Initialize
502 // compute an appropriate address type (cases #3 and #5).
503 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
504 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
505 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
506 assert(offs != Type::OffsetBot, "offset must be a constant");
507 t = base_t->add_offset(offs)->is_oopptr();
508 }
509 int inst_id = base_t->instance_id();
510 assert(!t->is_known_instance() || t->instance_id() == inst_id,
511 "old type must be non-instance or match new type");
512
513 // The type 't' could be subclass of 'base_t'.
514 // As result t->offset() could be large then base_t's size and it will
515 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
516 // constructor verifies correctness of the offset.
517 //
518 // It could happened on subclass's branch (from the type profiling
519 // inlining) which was not eliminated during parsing since the exactness
520 // of the allocation type was not propagated to the subclass type check.
521 //
522 // Do nothing for such AddP node and don't process its users since
523 // this code branch will go away.
524 //
525 if (!t->is_known_instance() &&
526 !t->klass()->equals(base_t->klass()) &&
527 t->klass()->is_subtype_of(base_t->klass())) {
528 return false; // bail out
529 }
530
531 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
532 // Do NOT remove the next call: ensure an new alias index is allocated
533 // for the instance type
534 int alias_idx = _compile->get_alias_index(tinst);
535 igvn->set_type(addp, tinst);
536 // record the allocation in the node map
537 set_map(addp->_idx, get_map(base->_idx));
538
539 // Set addp's Base and Address to 'base'.
540 Node *abase = addp->in(AddPNode::Base);
541 Node *adr = addp->in(AddPNode::Address);
542 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
543 adr->in(0)->_idx == (uint)inst_id) {
544 // Skip AddP cases #3 and #5.
545 } else {
546 assert(!abase->is_top(), "sanity"); // AddP case #3
547 if (abase != base) {
548 igvn->hash_delete(addp);
549 addp->set_req(AddPNode::Base, base);
550 if (abase == adr) {
551 addp->set_req(AddPNode::Address, base);
552 } else {
553 // AddP case #4 (adr is array's element offset AddP node)
554 #ifdef ASSERT
555 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
556 assert(adr->is_AddP() && atype != NULL &&
557 atype->instance_id() == inst_id, "array's element offset should be processed first");
558 #endif
559 }
560 igvn->hash_insert(addp);
561 }
562 }
563 // Put on IGVN worklist since at least addp's type was changed above.
564 record_for_optimizer(addp);
565 return true;
566 }
567
568 //
569 // Create a new version of orig_phi if necessary. Returns either the newly
570 // created phi or an existing phi. Sets create_new to indicate wheter a new
571 // phi was created. Cache the last newly created phi in the node map.
572 //
573 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created) {
574 Compile *C = _compile;
575 new_created = false;
576 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
577 // nothing to do if orig_phi is bottom memory or matches alias_idx
578 if (phi_alias_idx == alias_idx) {
579 return orig_phi;
580 }
581 // have we already created a Phi for this alias index?
582 PhiNode *result = get_map_phi(orig_phi->_idx);
583 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
584 return result;
585 }
586 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
587 if (C->do_escape_analysis() == true && !C->failing()) {
588 // Retry compilation without escape analysis.
589 // If this is the first failure, the sentinel string will "stick"
590 // to the Compile object, and the C2Compiler will see it and retry.
591 C->record_failure(C2Compiler::retry_no_escape_analysis());
592 }
593 return NULL;
594 }
595 orig_phi_worklist.append_if_missing(orig_phi);
596 const TypePtr *atype = C->get_adr_type(alias_idx);
597 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
598 set_map_phi(orig_phi->_idx, result);
599 igvn->set_type(result, result->bottom_type());
600 record_for_optimizer(result);
601 new_created = true;
602 return result;
603 }
604
605 //
606 // Return a new version of Memory Phi "orig_phi" with the inputs having the
607 // specified alias index.
608 //
609 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
610
611 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
612 Compile *C = _compile;
613 bool new_phi_created;
614 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
615 if (!new_phi_created) {
616 return result;
617 }
618
619 GrowableArray<PhiNode *> phi_list;
620 GrowableArray<uint> cur_input;
621
622 PhiNode *phi = orig_phi;
623 uint idx = 1;
624 bool finished = false;
625 while(!finished) {
626 while (idx < phi->req()) {
627 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
628 if (mem != NULL && mem->is_Phi()) {
629 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
630 if (new_phi_created) {
631 // found an phi for which we created a new split, push current one on worklist and begin
632 // processing new one
633 phi_list.push(phi);
634 cur_input.push(idx);
635 phi = mem->as_Phi();
636 result = newphi;
637 idx = 1;
638 continue;
639 } else {
640 mem = newphi;
641 }
642 }
643 if (C->failing()) {
644 return NULL;
645 }
646 result->set_req(idx++, mem);
647 }
648 #ifdef ASSERT
649 // verify that the new Phi has an input for each input of the original
650 assert( phi->req() == result->req(), "must have same number of inputs.");
651 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
652 #endif
653 // Check if all new phi's inputs have specified alias index.
654 // Otherwise use old phi.
655 for (uint i = 1; i < phi->req(); i++) {
656 Node* in = result->in(i);
657 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
658 }
659 // we have finished processing a Phi, see if there are any more to do
660 finished = (phi_list.length() == 0 );
661 if (!finished) {
662 phi = phi_list.pop();
663 idx = cur_input.pop();
664 PhiNode *prev_result = get_map_phi(phi->_idx);
665 prev_result->set_req(idx++, result);
666 result = prev_result;
667 }
668 }
669 return result;
670 }
671
672
673 //
674 // The next methods are derived from methods in MemNode.
675 //
676 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *tinst) {
677 Node *mem = mmem;
678 // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally
679 // means an array I have not precisely typed yet. Do not do any
680 // alias stuff with it any time soon.
681 if( tinst->base() != Type::AnyPtr &&
682 !(tinst->klass()->is_java_lang_Object() &&
683 tinst->offset() == Type::OffsetBot) ) {
684 mem = mmem->memory_at(alias_idx);
685 // Update input if it is progress over what we have now
686 }
687 return mem;
688 }
689
690 //
691 // Search memory chain of "mem" to find a MemNode whose address
692 // is the specified alias index.
693 //
694 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *phase) {
695 if (orig_mem == NULL)
696 return orig_mem;
697 Compile* C = phase->C;
698 const TypeOopPtr *tinst = C->get_adr_type(alias_idx)->isa_oopptr();
699 bool is_instance = (tinst != NULL) && tinst->is_known_instance();
700 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
701 Node *prev = NULL;
702 Node *result = orig_mem;
703 while (prev != result) {
704 prev = result;
705 if (result == start_mem)
706 break; // hit one of our sentinels
707 if (result->is_Mem()) {
708 const Type *at = phase->type(result->in(MemNode::Address));
709 if (at != Type::TOP) {
710 assert (at->isa_ptr() != NULL, "pointer type required.");
711 int idx = C->get_alias_index(at->is_ptr());
712 if (idx == alias_idx)
713 break;
714 }
715 result = result->in(MemNode::Memory);
716 }
717 if (!is_instance)
718 continue; // don't search further for non-instance types
719 // skip over a call which does not affect this memory slice
720 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
721 Node *proj_in = result->in(0);
722 if (proj_in->is_Allocate() && proj_in->_idx == (uint)tinst->instance_id()) {
723 break; // hit one of our sentinels
724 } else if (proj_in->is_Call()) {
725 CallNode *call = proj_in->as_Call();
726 if (!call->may_modify(tinst, phase)) {
727 result = call->in(TypeFunc::Memory);
728 }
729 } else if (proj_in->is_Initialize()) {
730 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
731 // Stop if this is the initialization for the object instance which
732 // which contains this memory slice, otherwise skip over it.
733 if (alloc == NULL || alloc->_idx != (uint)tinst->instance_id()) {
734 result = proj_in->in(TypeFunc::Memory);
735 }
736 } else if (proj_in->is_MemBar()) {
737 result = proj_in->in(TypeFunc::Memory);
738 }
739 } else if (result->is_MergeMem()) {
740 MergeMemNode *mmem = result->as_MergeMem();
741 result = step_through_mergemem(mmem, alias_idx, tinst);
742 if (result == mmem->base_memory()) {
743 // Didn't find instance memory, search through general slice recursively.
744 result = mmem->memory_at(C->get_general_index(alias_idx));
745 result = find_inst_mem(result, alias_idx, orig_phis, phase);
746 if (C->failing()) {
747 return NULL;
748 }
749 mmem->set_memory_at(alias_idx, result);
750 }
751 } else if (result->is_Phi() &&
752 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
753 Node *un = result->as_Phi()->unique_input(phase);
754 if (un != NULL) {
755 result = un;
756 } else {
757 break;
758 }
759 } else if (result->Opcode() == Op_SCMemProj) {
760 assert(result->in(0)->is_LoadStore(), "sanity");
761 const Type *at = phase->type(result->in(0)->in(MemNode::Address));
762 if (at != Type::TOP) {
763 assert (at->isa_ptr() != NULL, "pointer type required.");
764 int idx = C->get_alias_index(at->is_ptr());
765 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
766 break;
767 }
768 result = result->in(0)->in(MemNode::Memory);
769 }
770 }
771 if (result->is_Phi()) {
772 PhiNode *mphi = result->as_Phi();
773 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
774 const TypePtr *t = mphi->adr_type();
775 if (C->get_alias_index(t) != alias_idx) {
776 // Create a new Phi with the specified alias index type.
777 result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
778 } else if (!is_instance) {
779 // Push all non-instance Phis on the orig_phis worklist to update inputs
780 // during Phase 4 if needed.
781 orig_phis.append_if_missing(mphi);
782 }
783 }
784 // the result is either MemNode, PhiNode, InitializeNode.
785 return result;
786 }
787
788
789 //
790 // Convert the types of unescaped object to instance types where possible,
791 // propagate the new type information through the graph, and update memory
792 // edges and MergeMem inputs to reflect the new type.
793 //
794 // We start with allocations (and calls which may be allocations) on alloc_worklist.
795 // The processing is done in 4 phases:
796 //
797 // Phase 1: Process possible allocations from alloc_worklist. Create instance
798 // types for the CheckCastPP for allocations where possible.
799 // Propagate the the new types through users as follows:
800 // casts and Phi: push users on alloc_worklist
801 // AddP: cast Base and Address inputs to the instance type
802 // push any AddP users on alloc_worklist and push any memnode
803 // users onto memnode_worklist.
804 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
805 // search the Memory chain for a store with the appropriate type
806 // address type. If a Phi is found, create a new version with
807 // the appropriate memory slices from each of the Phi inputs.
808 // For stores, process the users as follows:
809 // MemNode: push on memnode_worklist
810 // MergeMem: push on mergemem_worklist
811 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
812 // moving the first node encountered of each instance type to the
813 // the input corresponding to its alias index.
814 // appropriate memory slice.
815 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
816 //
817 // In the following example, the CheckCastPP nodes are the cast of allocation
818 // results and the allocation of node 29 is unescaped and eligible to be an
819 // instance type.
820 //
821 // We start with:
822 //
823 // 7 Parm #memory
824 // 10 ConI "12"
825 // 19 CheckCastPP "Foo"
826 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
827 // 29 CheckCastPP "Foo"
828 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
829 //
830 // 40 StoreP 25 7 20 ... alias_index=4
831 // 50 StoreP 35 40 30 ... alias_index=4
832 // 60 StoreP 45 50 20 ... alias_index=4
833 // 70 LoadP _ 60 30 ... alias_index=4
834 // 80 Phi 75 50 60 Memory alias_index=4
835 // 90 LoadP _ 80 30 ... alias_index=4
836 // 100 LoadP _ 80 20 ... alias_index=4
837 //
838 //
839 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
840 // and creating a new alias index for node 30. This gives:
841 //
842 // 7 Parm #memory
843 // 10 ConI "12"
844 // 19 CheckCastPP "Foo"
845 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
846 // 29 CheckCastPP "Foo" iid=24
847 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
848 //
849 // 40 StoreP 25 7 20 ... alias_index=4
850 // 50 StoreP 35 40 30 ... alias_index=6
851 // 60 StoreP 45 50 20 ... alias_index=4
852 // 70 LoadP _ 60 30 ... alias_index=6
853 // 80 Phi 75 50 60 Memory alias_index=4
854 // 90 LoadP _ 80 30 ... alias_index=6
855 // 100 LoadP _ 80 20 ... alias_index=4
856 //
857 // In phase 2, new memory inputs are computed for the loads and stores,
858 // And a new version of the phi is created. In phase 4, the inputs to
859 // node 80 are updated and then the memory nodes are updated with the
860 // values computed in phase 2. This results in:
861 //
862 // 7 Parm #memory
863 // 10 ConI "12"
864 // 19 CheckCastPP "Foo"
865 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
866 // 29 CheckCastPP "Foo" iid=24
867 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
868 //
869 // 40 StoreP 25 7 20 ... alias_index=4
870 // 50 StoreP 35 7 30 ... alias_index=6
871 // 60 StoreP 45 40 20 ... alias_index=4
872 // 70 LoadP _ 50 30 ... alias_index=6
873 // 80 Phi 75 40 60 Memory alias_index=4
874 // 120 Phi 75 50 50 Memory alias_index=6
875 // 90 LoadP _ 120 30 ... alias_index=6
876 // 100 LoadP _ 80 20 ... alias_index=4
877 //
878 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
879 GrowableArray<Node *> memnode_worklist;
880 GrowableArray<Node *> mergemem_worklist;
881 GrowableArray<PhiNode *> orig_phis;
882 PhaseGVN *igvn = _compile->initial_gvn();
883 uint new_index_start = (uint) _compile->num_alias_types();
884 VectorSet visited(Thread::current()->resource_area());
885 VectorSet ptset(Thread::current()->resource_area());
886
887
888 // Phase 1: Process possible allocations from alloc_worklist.
889 // Create instance types for the CheckCastPP for allocations where possible.
890 //
891 // (Note: don't forget to change the order of the second AddP node on
892 // the alloc_worklist if the order of the worklist processing is changed,
893 // see the comment in find_second_addp().)
894 //
895 while (alloc_worklist.length() != 0) {
896 Node *n = alloc_worklist.pop();
897 uint ni = n->_idx;
898 const TypeOopPtr* tinst = NULL;
899 if (n->is_Call()) {
900 CallNode *alloc = n->as_Call();
901 // copy escape information to call node
902 PointsToNode* ptn = ptnode_adr(alloc->_idx);
903 PointsToNode::EscapeState es = escape_state(alloc, igvn);
904 // We have an allocation or call which returns a Java object,
905 // see if it is unescaped.
906 if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
907 continue;
908 if (alloc->is_Allocate()) {
909 // Set the scalar_replaceable flag before the next check.
910 alloc->as_Allocate()->_is_scalar_replaceable = true;
911 }
912 // find CheckCastPP of call return value
913 n = alloc->result_cast();
914 if (n == NULL || // No uses accept Initialize or
915 !n->is_CheckCastPP()) // not unique CheckCastPP.
916 continue;
917 // The inline code for Object.clone() casts the allocation result to
918 // java.lang.Object and then to the actual type of the allocated
919 // object. Detect this case and use the second cast.
920 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
921 // the allocation result is cast to java.lang.Object and then
922 // to the actual Array type.
923 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
924 && (alloc->is_AllocateArray() ||
925 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
926 Node *cast2 = NULL;
927 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
928 Node *use = n->fast_out(i);
929 if (use->is_CheckCastPP()) {
930 cast2 = use;
931 break;
932 }
933 }
934 if (cast2 != NULL) {
935 n = cast2;
936 } else {
937 continue;
938 }
939 }
940 set_escape_state(n->_idx, es);
941 // in order for an object to be scalar-replaceable, it must be:
942 // - a direct allocation (not a call returning an object)
943 // - non-escaping
944 // - eligible to be a unique type
945 // - not determined to be ineligible by escape analysis
946 set_map(alloc->_idx, n);
947 set_map(n->_idx, alloc);
948 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
949 if (t == NULL)
950 continue; // not a TypeInstPtr
951 tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
952 igvn->hash_delete(n);
953 igvn->set_type(n, tinst);
954 n->raise_bottom_type(tinst);
955 igvn->hash_insert(n);
956 record_for_optimizer(n);
957 if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
958 (t->isa_instptr() || t->isa_aryptr())) {
959
960 // First, put on the worklist all Field edges from Connection Graph
961 // which is more accurate then putting immediate users from Ideal Graph.
962 for (uint e = 0; e < ptn->edge_count(); e++) {
963 Node *use = ptnode_adr(ptn->edge_target(e))->_node;
964 assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
965 "only AddP nodes are Field edges in CG");
966 if (use->outcnt() > 0) { // Don't process dead nodes
967 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
968 if (addp2 != NULL) {
969 assert(alloc->is_AllocateArray(),"array allocation was expected");
970 alloc_worklist.append_if_missing(addp2);
971 }
972 alloc_worklist.append_if_missing(use);
973 }
974 }
975
976 // An allocation may have an Initialize which has raw stores. Scan
977 // the users of the raw allocation result and push AddP users
978 // on alloc_worklist.
979 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
980 assert (raw_result != NULL, "must have an allocation result");
981 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
982 Node *use = raw_result->fast_out(i);
983 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
984 Node* addp2 = find_second_addp(use, raw_result);
985 if (addp2 != NULL) {
986 assert(alloc->is_AllocateArray(),"array allocation was expected");
987 alloc_worklist.append_if_missing(addp2);
988 }
989 alloc_worklist.append_if_missing(use);
990 } else if (use->is_Initialize()) {
991 memnode_worklist.append_if_missing(use);
992 }
993 }
994 }
995 } else if (n->is_AddP()) {
996 ptset.Clear();
997 PointsTo(ptset, get_addp_base(n), igvn);
998 assert(ptset.Size() == 1, "AddP address is unique");
999 uint elem = ptset.getelem(); // Allocation node's index
1000 if (elem == _phantom_object)
1001 continue; // Assume the value was set outside this method.
1002 Node *base = get_map(elem); // CheckCastPP node
1003 if (!split_AddP(n, base, igvn)) continue; // wrong type
1004 tinst = igvn->type(base)->isa_oopptr();
1005 } else if (n->is_Phi() ||
1006 n->is_CheckCastPP() ||
1007 n->is_EncodeP() ||
1008 n->is_DecodeN() ||
1009 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1010 if (visited.test_set(n->_idx)) {
1011 assert(n->is_Phi(), "loops only through Phi's");
1012 continue; // already processed
1013 }
1014 ptset.Clear();
1015 PointsTo(ptset, n, igvn);
1016 if (ptset.Size() == 1) {
1017 uint elem = ptset.getelem(); // Allocation node's index
1018 if (elem == _phantom_object)
1019 continue; // Assume the value was set outside this method.
1020 Node *val = get_map(elem); // CheckCastPP node
1021 TypeNode *tn = n->as_Type();
1022 tinst = igvn->type(val)->isa_oopptr();
1023 assert(tinst != NULL && tinst->is_known_instance() &&
1024 (uint)tinst->instance_id() == elem , "instance type expected.");
1025
1026 const Type *tn_type = igvn->type(tn);
1027 const TypeOopPtr *tn_t;
1028 if (tn_type->isa_narrowoop()) {
1029 tn_t = tn_type->make_ptr()->isa_oopptr();
1030 } else {
1031 tn_t = tn_type->isa_oopptr();
1032 }
1033
1034 if (tn_t != NULL &&
1035 tinst->cast_to_instance_id(TypeOopPtr::InstanceBot)->higher_equal(tn_t)) {
1036 if (tn_type->isa_narrowoop()) {
1037 tn_type = tinst->make_narrowoop();
1038 } else {
1039 tn_type = tinst;
1040 }
1041 igvn->hash_delete(tn);
1042 igvn->set_type(tn, tn_type);
1043 tn->set_type(tn_type);
1044 igvn->hash_insert(tn);
1045 record_for_optimizer(n);
1046 } else {
1047 continue; // wrong type
1048 }
1049 }
1050 } else {
1051 continue;
1052 }
1053 // push users on appropriate worklist
1054 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1055 Node *use = n->fast_out(i);
1056 if(use->is_Mem() && use->in(MemNode::Address) == n) {
1057 memnode_worklist.append_if_missing(use);
1058 } else if (use->is_Initialize()) {
1059 memnode_worklist.append_if_missing(use);
1060 } else if (use->is_MergeMem()) {
1061 mergemem_worklist.append_if_missing(use);
1062 } else if (use->is_SafePoint() && tinst != NULL) {
1063 // Look for MergeMem nodes for calls which reference unique allocation
1064 // (through CheckCastPP nodes) even for debug info.
1065 Node* m = use->in(TypeFunc::Memory);
1066 uint iid = tinst->instance_id();
1067 while (m->is_Proj() && m->in(0)->is_SafePoint() &&
1068 m->in(0) != use && !m->in(0)->_idx != iid) {
1069 m = m->in(0)->in(TypeFunc::Memory);
1070 }
1071 if (m->is_MergeMem()) {
1072 mergemem_worklist.append_if_missing(m);
1073 }
1074 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1075 Node* addp2 = find_second_addp(use, n);
1076 if (addp2 != NULL) {
1077 alloc_worklist.append_if_missing(addp2);
1078 }
1079 alloc_worklist.append_if_missing(use);
1080 } else if (use->is_Phi() ||
1081 use->is_CheckCastPP() ||
1082 use->is_EncodeP() ||
1083 use->is_DecodeN() ||
1084 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1085 alloc_worklist.append_if_missing(use);
1086 }
1087 }
1088
1089 }
1090 // New alias types were created in split_AddP().
1091 uint new_index_end = (uint) _compile->num_alias_types();
1092
1093 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1094 // compute new values for Memory inputs (the Memory inputs are not
1095 // actually updated until phase 4.)
1096 if (memnode_worklist.length() == 0)
1097 return; // nothing to do
1098
1099 while (memnode_worklist.length() != 0) {
1100 Node *n = memnode_worklist.pop();
1101 if (visited.test_set(n->_idx))
1102 continue;
1103 if (n->is_Phi()) {
1104 assert(n->as_Phi()->adr_type() != TypePtr::BOTTOM, "narrow memory slice required");
1105 // we don't need to do anything, but the users must be pushed if we haven't processed
1106 // this Phi before
1107 } else if (n->is_Initialize()) {
1108 // we don't need to do anything, but the users of the memory projection must be pushed
1109 n = n->as_Initialize()->proj_out(TypeFunc::Memory);
1110 if (n == NULL)
1111 continue;
1112 } else {
1113 assert(n->is_Mem(), "memory node required.");
1114 Node *addr = n->in(MemNode::Address);
1115 assert(addr->is_AddP(), "AddP required");
1116 const Type *addr_t = igvn->type(addr);
1117 if (addr_t == Type::TOP)
1118 continue;
1119 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1120 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1121 assert ((uint)alias_idx < new_index_end, "wrong alias index");
1122 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1123 if (_compile->failing()) {
1124 return;
1125 }
1126 if (mem != n->in(MemNode::Memory)) {
1127 set_map(n->_idx, mem);
1128 ptnode_adr(n->_idx)->_node = n;
1129 }
1130 if (n->is_Load()) {
1131 continue; // don't push users
1132 } else if (n->is_LoadStore()) {
1133 // get the memory projection
1134 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1135 Node *use = n->fast_out(i);
1136 if (use->Opcode() == Op_SCMemProj) {
1137 n = use;
1138 break;
1139 }
1140 }
1141 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1142 }
1143 }
1144 // push user on appropriate worklist
1145 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1146 Node *use = n->fast_out(i);
1147 if (use->is_Phi()) {
1148 memnode_worklist.append_if_missing(use);
1149 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1150 memnode_worklist.append_if_missing(use);
1151 } else if (use->is_Initialize()) {
1152 memnode_worklist.append_if_missing(use);
1153 } else if (use->is_MergeMem()) {
1154 mergemem_worklist.append_if_missing(use);
1155 }
1156 }
1157 }
1158
1159 // Phase 3: Process MergeMem nodes from mergemem_worklist.
1160 // Walk each memory moving the first node encountered of each
1161 // instance type to the the input corresponding to its alias index.
1162 while (mergemem_worklist.length() != 0) {
1163 Node *n = mergemem_worklist.pop();
1164 assert(n->is_MergeMem(), "MergeMem node required.");
1165 if (visited.test_set(n->_idx))
1166 continue;
1167 MergeMemNode *nmm = n->as_MergeMem();
1168 // Note: we don't want to use MergeMemStream here because we only want to
1169 // scan inputs which exist at the start, not ones we add during processing.
1170 uint nslices = nmm->req();
1171 igvn->hash_delete(nmm);
1172 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1173 Node* mem = nmm->in(i);
1174 Node* cur = NULL;
1175 if (mem == NULL || mem->is_top())
1176 continue;
1177 while (mem->is_Mem()) {
1178 const Type *at = igvn->type(mem->in(MemNode::Address));
1179 if (at != Type::TOP) {
1180 assert (at->isa_ptr() != NULL, "pointer type required.");
1181 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1182 if (idx == i) {
1183 if (cur == NULL)
1184 cur = mem;
1185 } else {
1186 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1187 nmm->set_memory_at(idx, mem);
1188 }
1189 }
1190 }
1191 mem = mem->in(MemNode::Memory);
1192 }
1193 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1194 // Find any instance of the current type if we haven't encountered
1195 // a value of the instance along the chain.
1196 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1197 if((uint)_compile->get_general_index(ni) == i) {
1198 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1199 if (nmm->is_empty_memory(m)) {
1200 Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1201 if (_compile->failing()) {
1202 return;
1203 }
1204 nmm->set_memory_at(ni, result);
1205 }
1206 }
1207 }
1208 }
1209 // Find the rest of instances values
1210 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1211 const TypeOopPtr *tinst = igvn->C->get_adr_type(ni)->isa_oopptr();
1212 Node* result = step_through_mergemem(nmm, ni, tinst);
1213 if (result == nmm->base_memory()) {
1214 // Didn't find instance memory, search through general slice recursively.
1215 result = nmm->memory_at(igvn->C->get_general_index(ni));
1216 result = find_inst_mem(result, ni, orig_phis, igvn);
1217 if (_compile->failing()) {
1218 return;
1219 }
1220 nmm->set_memory_at(ni, result);
1221 }
1222 }
1223 igvn->hash_insert(nmm);
1224 record_for_optimizer(nmm);
1225
1226 // Propagate new memory slices to following MergeMem nodes.
1227 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1228 Node *use = n->fast_out(i);
1229 if (use->is_Call()) {
1230 CallNode* in = use->as_Call();
1231 if (in->proj_out(TypeFunc::Memory) != NULL) {
1232 Node* m = in->proj_out(TypeFunc::Memory);
1233 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
1234 Node* mm = m->fast_out(j);
1235 if (mm->is_MergeMem()) {
1236 mergemem_worklist.append_if_missing(mm);
1237 }
1238 }
1239 }
1240 if (use->is_Allocate()) {
1241 use = use->as_Allocate()->initialization();
1242 if (use == NULL) {
1243 continue;
1244 }
1245 }
1246 }
1247 if (use->is_Initialize()) {
1248 InitializeNode* in = use->as_Initialize();
1249 if (in->proj_out(TypeFunc::Memory) != NULL) {
1250 Node* m = in->proj_out(TypeFunc::Memory);
1251 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
1252 Node* mm = m->fast_out(j);
1253 if (mm->is_MergeMem()) {
1254 mergemem_worklist.append_if_missing(mm);
1255 }
1256 }
1257 }
1258 }
1259 }
1260 }
1261
1262 // Phase 4: Update the inputs of non-instance memory Phis and
1263 // the Memory input of memnodes
1264 // First update the inputs of any non-instance Phi's from
1265 // which we split out an instance Phi. Note we don't have
1266 // to recursively process Phi's encounted on the input memory
1267 // chains as is done in split_memory_phi() since they will
1268 // also be processed here.
1269 for (int j = 0; j < orig_phis.length(); j++) {
1270 PhiNode *phi = orig_phis.at(j);
1271 int alias_idx = _compile->get_alias_index(phi->adr_type());
1272 igvn->hash_delete(phi);
1273 for (uint i = 1; i < phi->req(); i++) {
1274 Node *mem = phi->in(i);
1275 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1276 if (_compile->failing()) {
1277 return;
1278 }
1279 if (mem != new_mem) {
1280 phi->set_req(i, new_mem);
1281 }
1282 }
1283 igvn->hash_insert(phi);
1284 record_for_optimizer(phi);
1285 }
1286
1287 // Update the memory inputs of MemNodes with the value we computed
1288 // in Phase 2.
1289 for (uint i = 0; i < nodes_size(); i++) {
1290 Node *nmem = get_map(i);
1291 if (nmem != NULL) {
1292 Node *n = ptnode_adr(i)->_node;
1293 if (n != NULL && n->is_Mem()) {
1294 igvn->hash_delete(n);
1295 n->set_req(MemNode::Memory, nmem);
1296 igvn->hash_insert(n);
1297 record_for_optimizer(n);
1298 }
1299 }
1300 }
1301 }
1302
1303 bool ConnectionGraph::has_candidates(Compile *C) {
1304 // EA brings benefits only when the code has allocations and/or locks which
1305 // are represented by ideal Macro nodes.
1306 int cnt = C->macro_count();
1307 for( int i=0; i < cnt; i++ ) {
1308 Node *n = C->macro_node(i);
1309 if ( n->is_Allocate() )
1310 return true;
1311 if( n->is_Lock() ) {
1312 Node* obj = n->as_Lock()->obj_node()->uncast();
1313 if( !(obj->is_Parm() || obj->is_Con()) )
1314 return true;
1315 }
1316 }
1317 return false;
1318 }
1319
1320 bool ConnectionGraph::compute_escape() {
1321 Compile* C = _compile;
1322
1323 // 1. Populate Connection Graph (CG) with Ideal nodes.
1324
1325 Unique_Node_List worklist_init;
1326 worklist_init.map(C->unique(), NULL); // preallocate space
1327
1328 // Initialize worklist
1329 if (C->root() != NULL) {
1330 worklist_init.push(C->root());
1331 }
1332
1333 GrowableArray<int> cg_worklist;
1334 PhaseGVN* igvn = C->initial_gvn();
1335 bool has_allocations = false;
1336
1337 // Push all useful nodes onto CG list and set their type.
1338 for( uint next = 0; next < worklist_init.size(); ++next ) {
1339 Node* n = worklist_init.at(next);
1340 record_for_escape_analysis(n, igvn);
1341 // Only allocations and java static calls results are checked
1342 // for an escape status. See process_call_result() below.
1343 if (n->is_Allocate() || n->is_CallStaticJava() &&
1344 ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1345 has_allocations = true;
1346 }
1347 if(n->is_AddP())
1348 cg_worklist.append(n->_idx);
1349 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1350 Node* m = n->fast_out(i); // Get user
1351 worklist_init.push(m);
1352 }
1353 }
1354
1355 if (!has_allocations) {
1356 _collecting = false;
1357 return false; // Nothing to do.
1358 }
1359
1360 // 2. First pass to create simple CG edges (doesn't require to walk CG).
1361 uint delayed_size = _delayed_worklist.size();
1362 for( uint next = 0; next < delayed_size; ++next ) {
1363 Node* n = _delayed_worklist.at(next);
1364 build_connection_graph(n, igvn);
1365 }
1366
1367 // 3. Pass to create fields edges (Allocate -F-> AddP).
1368 uint cg_length = cg_worklist.length();
1369 for( uint next = 0; next < cg_length; ++next ) {
1370 int ni = cg_worklist.at(next);
1371 build_connection_graph(ptnode_adr(ni)->_node, igvn);
1372 }
1373
1374 cg_worklist.clear();
1375 cg_worklist.append(_phantom_object);
1376
1377 // 4. Build Connection Graph which need
1378 // to walk the connection graph.
1379 for (uint ni = 0; ni < nodes_size(); ni++) {
1380 PointsToNode* ptn = ptnode_adr(ni);
1381 Node *n = ptn->_node;
1382 if (n != NULL) { // Call, AddP, LoadP, StoreP
1383 build_connection_graph(n, igvn);
1384 if (ptn->node_type() != PointsToNode::UnknownType)
1385 cg_worklist.append(n->_idx); // Collect CG nodes
1386 }
1387 }
1388
1389 VectorSet ptset(Thread::current()->resource_area());
1390 GrowableArray<uint> deferred_edges;
1391 VectorSet visited(Thread::current()->resource_area());
1392
1393 // 5. Remove deferred edges from the graph and collect
1394 // information needed for type splitting.
1395 cg_length = cg_worklist.length();
1396 for( uint next = 0; next < cg_length; ++next ) {
1397 int ni = cg_worklist.at(next);
1398 PointsToNode* ptn = ptnode_adr(ni);
1399 PointsToNode::NodeType nt = ptn->node_type();
1400 if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1401 remove_deferred(ni, &deferred_edges, &visited);
1402 Node *n = ptn->_node;
1403 if (n->is_AddP()) {
1404 // Search for objects which are not scalar replaceable.
1405 // Mark their escape state as ArgEscape to propagate the state
1406 // to referenced objects.
1407 // Note: currently there are no difference in compiler optimizations
1408 // for ArgEscape objects and NoEscape objects which are not
1409 // scalar replaceable.
1410
1411 int offset = ptn->offset();
1412 Node *base = get_addp_base(n);
1413 ptset.Clear();
1414 PointsTo(ptset, base, igvn);
1415 int ptset_size = ptset.Size();
1416
1417 // Check if a field's initializing value is recorded and add
1418 // a corresponding NULL field's value if it is not recorded.
1419 // Connection Graph does not record a default initialization by NULL
1420 // captured by Initialize node.
1421 //
1422 // Note: it will disable scalar replacement in some cases:
1423 //
1424 // Point p[] = new Point[1];
1425 // p[0] = new Point(); // Will be not scalar replaced
1426 //
1427 // but it will save us from incorrect optimizations in next cases:
1428 //
1429 // Point p[] = new Point[1];
1430 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1431 //
1432 // Without a control flow analysis we can't distinguish above cases.
1433 //
1434 if (offset != Type::OffsetBot && ptset_size == 1) {
1435 uint elem = ptset.getelem(); // Allocation node's index
1436 // It does not matter if it is not Allocation node since
1437 // only non-escaping allocations are scalar replaced.
1438 if (ptnode_adr(elem)->_node->is_Allocate() &&
1439 ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
1440 AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
1441 InitializeNode* ini = alloc->initialization();
1442 Node* value = NULL;
1443 if (ini != NULL) {
1444 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1445 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), igvn);
1446 if (store != NULL && store->is_Store())
1447 value = store->in(MemNode::ValueIn);
1448 }
1449 if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1450 // A field's initializing value was not recorded. Add NULL.
1451 uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1452 add_pointsto_edge(ni, null_idx);
1453 }
1454 }
1455 }
1456
1457 // An object is not scalar replaceable if the field which may point
1458 // to it has unknown offset (unknown element of an array of objects).
1459 //
1460 if (offset == Type::OffsetBot) {
1461 uint e_cnt = ptn->edge_count();
1462 for (uint ei = 0; ei < e_cnt; ei++) {
1463 uint npi = ptn->edge_target(ei);
1464 set_escape_state(npi, PointsToNode::ArgEscape);
1465 ptnode_adr(npi)->_scalar_replaceable = false;
1466 }
1467 }
1468
1469 // Currently an object is not scalar replaceable if a LoadStore node
1470 // access its field since the field value is unknown after it.
1471 //
1472 bool has_LoadStore = false;
1473 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1474 Node *use = n->fast_out(i);
1475 if (use->is_LoadStore()) {
1476 has_LoadStore = true;
1477 break;
1478 }
1479 }
1480 // An object is not scalar replaceable if the address points
1481 // to unknown field (unknown element for arrays, offset is OffsetBot).
1482 //
1483 // Or the address may point to more then one object. This may produce
1484 // the false positive result (set scalar_replaceable to false)
1485 // since the flow-insensitive escape analysis can't separate
1486 // the case when stores overwrite the field's value from the case
1487 // when stores happened on different control branches.
1488 //
1489 if (ptset_size > 1 || ptset_size != 0 &&
1490 (has_LoadStore || offset == Type::OffsetBot)) {
1491 for( VectorSetI j(&ptset); j.test(); ++j ) {
1492 set_escape_state(j.elem, PointsToNode::ArgEscape);
1493 ptnode_adr(j.elem)->_scalar_replaceable = false;
1494 }
1495 }
1496 }
1497 }
1498 }
1499
1500 // 6. Propagate escape states.
1501 GrowableArray<int> worklist;
1502 bool has_non_escaping_obj = false;
1503
1504 // push all GlobalEscape nodes on the worklist
1505 for( uint next = 0; next < cg_length; ++next ) {
1506 int nk = cg_worklist.at(next);
1507 if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
1508 worklist.push(nk);
1509 }
1510 // mark all nodes reachable from GlobalEscape nodes
1511 while(worklist.length() > 0) {
1512 PointsToNode* ptn = ptnode_adr(worklist.pop());
1513 uint e_cnt = ptn->edge_count();
1514 for (uint ei = 0; ei < e_cnt; ei++) {
1515 uint npi = ptn->edge_target(ei);
1516 PointsToNode *np = ptnode_adr(npi);
1517 if (np->escape_state() < PointsToNode::GlobalEscape) {
1518 np->set_escape_state(PointsToNode::GlobalEscape);
1519 worklist.push(npi);
1520 }
1521 }
1522 }
1523
1524 // push all ArgEscape nodes on the worklist
1525 for( uint next = 0; next < cg_length; ++next ) {
1526 int nk = cg_worklist.at(next);
1527 if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
1528 worklist.push(nk);
1529 }
1530 // mark all nodes reachable from ArgEscape nodes
1531 while(worklist.length() > 0) {
1532 PointsToNode* ptn = ptnode_adr(worklist.pop());
1533 if (ptn->node_type() == PointsToNode::JavaObject)
1534 has_non_escaping_obj = true; // Non GlobalEscape
1535 uint e_cnt = ptn->edge_count();
1536 for (uint ei = 0; ei < e_cnt; ei++) {
1537 uint npi = ptn->edge_target(ei);
1538 PointsToNode *np = ptnode_adr(npi);
1539 if (np->escape_state() < PointsToNode::ArgEscape) {
1540 np->set_escape_state(PointsToNode::ArgEscape);
1541 worklist.push(npi);
1542 }
1543 }
1544 }
1545
1546 GrowableArray<Node*> alloc_worklist;
1547
1548 // push all NoEscape nodes on the worklist
1549 for( uint next = 0; next < cg_length; ++next ) {
1550 int nk = cg_worklist.at(next);
1551 if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1552 worklist.push(nk);
1553 }
1554 // mark all nodes reachable from NoEscape nodes
1555 while(worklist.length() > 0) {
1556 PointsToNode* ptn = ptnode_adr(worklist.pop());
1557 if (ptn->node_type() == PointsToNode::JavaObject)
1558 has_non_escaping_obj = true; // Non GlobalEscape
1559 Node* n = ptn->_node;
1560 if (n->is_Allocate() && ptn->_scalar_replaceable ) {
1561 // Push scalar replaceable allocations on alloc_worklist
1562 // for processing in split_unique_types().
1563 alloc_worklist.append(n);
1564 }
1565 uint e_cnt = ptn->edge_count();
1566 for (uint ei = 0; ei < e_cnt; ei++) {
1567 uint npi = ptn->edge_target(ei);
1568 PointsToNode *np = ptnode_adr(npi);
1569 if (np->escape_state() < PointsToNode::NoEscape) {
1570 np->set_escape_state(PointsToNode::NoEscape);
1571 worklist.push(npi);
1572 }
1573 }
1574 }
1575
1576 _collecting = false;
1577 assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1578
1579 bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1580 if ( has_scalar_replaceable_candidates &&
1581 C->AliasLevel() >= 3 && EliminateAllocations ) {
1582
1583 // Now use the escape information to create unique types for
1584 // scalar replaceable objects.
1585 split_unique_types(alloc_worklist);
1586
1587 if (C->failing()) return false;
1588
1589 // Clean up after split unique types.
1590 ResourceMark rm;
1591 PhaseRemoveUseless pru(C->initial_gvn(), C->for_igvn());
1592
1593 C->print_method("After Escape Analysis", 2);
1594
1595 #ifdef ASSERT
1596 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1597 tty->print("=== No allocations eliminated for ");
1598 C->method()->print_short_name();
1599 if(!EliminateAllocations) {
1600 tty->print(" since EliminateAllocations is off ===");
1601 } else if(!has_scalar_replaceable_candidates) {
1602 tty->print(" since there are no scalar replaceable candidates ===");
1603 } else if(C->AliasLevel() < 3) {
1604 tty->print(" since AliasLevel < 3 ===");
1605 }
1606 tty->cr();
1607 #endif
1608 }
1609 return has_non_escaping_obj;
1610 }
1611
1612 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1613
1614 switch (call->Opcode()) {
1615 #ifdef ASSERT
1616 case Op_Allocate:
1617 case Op_AllocateArray:
1618 case Op_Lock:
1619 case Op_Unlock:
1620 assert(false, "should be done already");
1621 break;
1622 #endif
1623 case Op_CallLeafNoFP:
1624 {
1625 // Stub calls, objects do not escape but they are not scale replaceable.
1626 // Adjust escape state for outgoing arguments.
1627 const TypeTuple * d = call->tf()->domain();
1628 VectorSet ptset(Thread::current()->resource_area());
1629 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1630 const Type* at = d->field_at(i);
1631 Node *arg = call->in(i)->uncast();
1632 const Type *aat = phase->type(arg);
1633 if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr()) {
1634 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1635 aat->isa_ptr() != NULL, "expecting an Ptr");
1636 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1637 if (arg->is_AddP()) {
1638 //
1639 // The inline_native_clone() case when the arraycopy stub is called
1640 // after the allocation before Initialize and CheckCastPP nodes.
1641 //
1642 // Set AddP's base (Allocate) as not scalar replaceable since
1643 // pointer to the base (with offset) is passed as argument.
1644 //
1645 arg = get_addp_base(arg);
1646 }
1647 ptset.Clear();
1648 PointsTo(ptset, arg, phase);
1649 for( VectorSetI j(&ptset); j.test(); ++j ) {
1650 uint pt = j.elem;
1651 set_escape_state(pt, PointsToNode::ArgEscape);
1652 }
1653 }
1654 }
1655 break;
1656 }
1657
1658 case Op_CallStaticJava:
1659 // For a static call, we know exactly what method is being called.
1660 // Use bytecode estimator to record the call's escape affects
1661 {
1662 ciMethod *meth = call->as_CallJava()->method();
1663 BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1664 // fall-through if not a Java method or no analyzer information
1665 if (call_analyzer != NULL) {
1666 const TypeTuple * d = call->tf()->domain();
1667 VectorSet ptset(Thread::current()->resource_area());
1668 bool copy_dependencies = false;
1669 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1670 const Type* at = d->field_at(i);
1671 int k = i - TypeFunc::Parms;
1672
1673 if (at->isa_oopptr() != NULL) {
1674 Node *arg = call->in(i)->uncast();
1675
1676 bool global_escapes = false;
1677 bool fields_escapes = false;
1678 if (!call_analyzer->is_arg_stack(k)) {
1679 // The argument global escapes, mark everything it could point to
1680 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1681 global_escapes = true;
1682 } else {
1683 if (!call_analyzer->is_arg_local(k)) {
1684 // The argument itself doesn't escape, but any fields might
1685 fields_escapes = true;
1686 }
1687 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1688 copy_dependencies = true;
1689 }
1690
1691 ptset.Clear();
1692 PointsTo(ptset, arg, phase);
1693 for( VectorSetI j(&ptset); j.test(); ++j ) {
1694 uint pt = j.elem;
1695 if (global_escapes) {
1696 //The argument global escapes, mark everything it could point to
1697 set_escape_state(pt, PointsToNode::GlobalEscape);
1698 } else {
1699 if (fields_escapes) {
1700 // The argument itself doesn't escape, but any fields might
1701 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
1702 }
1703 set_escape_state(pt, PointsToNode::ArgEscape);
1704 }
1705 }
1706 }
1707 }
1708 if (copy_dependencies)
1709 call_analyzer->copy_dependencies(_compile->dependencies());
1710 break;
1711 }
1712 }
1713
1714 default:
1715 // Fall-through here if not a Java method or no analyzer information
1716 // or some other type of call, assume the worst case: all arguments
1717 // globally escape.
1718 {
1719 // adjust escape state for outgoing arguments
1720 const TypeTuple * d = call->tf()->domain();
1721 VectorSet ptset(Thread::current()->resource_area());
1722 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1723 const Type* at = d->field_at(i);
1724 if (at->isa_oopptr() != NULL) {
1725 Node *arg = call->in(i)->uncast();
1726 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1727 ptset.Clear();
1728 PointsTo(ptset, arg, phase);
1729 for( VectorSetI j(&ptset); j.test(); ++j ) {
1730 uint pt = j.elem;
1731 set_escape_state(pt, PointsToNode::GlobalEscape);
1732 }
1733 }
1734 }
1735 }
1736 }
1737 }
1738 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
1739 CallNode *call = resproj->in(0)->as_Call();
1740 uint call_idx = call->_idx;
1741 uint resproj_idx = resproj->_idx;
1742
1743 switch (call->Opcode()) {
1744 case Op_Allocate:
1745 {
1746 Node *k = call->in(AllocateNode::KlassNode);
1747 const TypeKlassPtr *kt;
1748 if (k->Opcode() == Op_LoadKlass) {
1749 kt = k->as_Load()->type()->isa_klassptr();
1750 } else {
1751 // Also works for DecodeN(LoadNKlass).
1752 kt = k->as_Type()->type()->isa_klassptr();
1753 }
1754 assert(kt != NULL, "TypeKlassPtr required.");
1755 ciKlass* cik = kt->klass();
1756 ciInstanceKlass* ciik = cik->as_instance_klass();
1757
1758 PointsToNode::EscapeState es;
1759 uint edge_to;
1760 if (cik->is_subclass_of(_compile->env()->Thread_klass()) || ciik->has_finalizer()) {
1761 es = PointsToNode::GlobalEscape;
1762 edge_to = _phantom_object; // Could not be worse
1763 } else {
1764 es = PointsToNode::NoEscape;
1765 edge_to = call_idx;
1766 }
1767 set_escape_state(call_idx, es);
1768 add_pointsto_edge(resproj_idx, edge_to);
1769 _processed.set(resproj_idx);
1770 break;
1771 }
1772
1773 case Op_AllocateArray:
1774 {
1775 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
1776 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
1777 // Not scalar replaceable if the length is not constant or too big.
1778 ptnode_adr(call_idx)->_scalar_replaceable = false;
1779 }
1780 set_escape_state(call_idx, PointsToNode::NoEscape);
1781 add_pointsto_edge(resproj_idx, call_idx);
1782 _processed.set(resproj_idx);
1783 break;
1784 }
1785
1786 case Op_CallStaticJava:
1787 // For a static call, we know exactly what method is being called.
1788 // Use bytecode estimator to record whether the call's return value escapes
1789 {
1790 bool done = true;
1791 const TypeTuple *r = call->tf()->range();
1792 const Type* ret_type = NULL;
1793
1794 if (r->cnt() > TypeFunc::Parms)
1795 ret_type = r->field_at(TypeFunc::Parms);
1796
1797 // Note: we use isa_ptr() instead of isa_oopptr() here because the
1798 // _multianewarray functions return a TypeRawPtr.
1799 if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
1800 _processed.set(resproj_idx);
1801 break; // doesn't return a pointer type
1802 }
1803 ciMethod *meth = call->as_CallJava()->method();
1804 const TypeTuple * d = call->tf()->domain();
1805 if (meth == NULL) {
1806 // not a Java method, assume global escape
1807 set_escape_state(call_idx, PointsToNode::GlobalEscape);
1808 add_pointsto_edge(resproj_idx, _phantom_object);
1809 } else {
1810 BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
1811 bool copy_dependencies = false;
1812
1813 if (call_analyzer->is_return_allocated()) {
1814 // Returns a newly allocated unescaped object, simply
1815 // update dependency information.
1816 // Mark it as NoEscape so that objects referenced by
1817 // it's fields will be marked as NoEscape at least.
1818 set_escape_state(call_idx, PointsToNode::NoEscape);
1819 add_pointsto_edge(resproj_idx, call_idx);
1820 copy_dependencies = true;
1821 } else if (call_analyzer->is_return_local()) {
1822 // determine whether any arguments are returned
1823 set_escape_state(call_idx, PointsToNode::NoEscape);
1824 bool ret_arg = false;
1825 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1826 const Type* at = d->field_at(i);
1827
1828 if (at->isa_oopptr() != NULL) {
1829 Node *arg = call->in(i)->uncast();
1830
1831 if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
1832 ret_arg = true;
1833 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
1834 if (arg_esp->node_type() == PointsToNode::UnknownType)
1835 done = false;
1836 else if (arg_esp->node_type() == PointsToNode::JavaObject)
1837 add_pointsto_edge(resproj_idx, arg->_idx);
1838 else
1839 add_deferred_edge(resproj_idx, arg->_idx);
1840 arg_esp->_hidden_alias = true;
1841 }
1842 }
1843 }
1844 if (done && !ret_arg) {
1845 // Returns unknown object.
1846 set_escape_state(call_idx, PointsToNode::GlobalEscape);
1847 add_pointsto_edge(resproj_idx, _phantom_object);
1848 }
1849 copy_dependencies = true;
1850 } else {
1851 set_escape_state(call_idx, PointsToNode::GlobalEscape);
1852 add_pointsto_edge(resproj_idx, _phantom_object);
1853 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1854 const Type* at = d->field_at(i);
1855 if (at->isa_oopptr() != NULL) {
1856 Node *arg = call->in(i)->uncast();
1857 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
1858 arg_esp->_hidden_alias = true;
1859 }
1860 }
1861 }
1862 if (copy_dependencies)
1863 call_analyzer->copy_dependencies(_compile->dependencies());
1864 }
1865 if (done)
1866 _processed.set(resproj_idx);
1867 break;
1868 }
1869
1870 default:
1871 // Some other type of call, assume the worst case that the
1872 // returned value, if any, globally escapes.
1873 {
1874 const TypeTuple *r = call->tf()->range();
1875 if (r->cnt() > TypeFunc::Parms) {
1876 const Type* ret_type = r->field_at(TypeFunc::Parms);
1877
1878 // Note: we use isa_ptr() instead of isa_oopptr() here because the
1879 // _multianewarray functions return a TypeRawPtr.
1880 if (ret_type->isa_ptr() != NULL) {
1881 set_escape_state(call_idx, PointsToNode::GlobalEscape);
1882 add_pointsto_edge(resproj_idx, _phantom_object);
1883 }
1884 }
1885 _processed.set(resproj_idx);
1886 }
1887 }
1888 }
1889
1890 // Populate Connection Graph with Ideal nodes and create simple
1891 // connection graph edges (do not need to check the node_type of inputs
1892 // or to call PointsTo() to walk the connection graph).
1893 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
1894 if (_processed.test(n->_idx))
1895 return; // No need to redefine node's state.
1896
1897 if (n->is_Call()) {
1898 // Arguments to allocation and locking don't escape.
1899 if (n->is_Allocate()) {
1900 add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
1901 record_for_optimizer(n);
1902 } else if (n->is_Lock() || n->is_Unlock()) {
1903 // Put Lock and Unlock nodes on IGVN worklist to process them during
1904 // the first IGVN optimization when escape information is still available.
1905 record_for_optimizer(n);
1906 _processed.set(n->_idx);
1907 } else {
1908 // Have to process call's arguments first.
1909 PointsToNode::NodeType nt = PointsToNode::UnknownType;
1910
1911 // Check if a call returns an object.
1912 const TypeTuple *r = n->as_Call()->tf()->range();
1913 if (n->is_CallStaticJava() && r->cnt() > TypeFunc::Parms &&
1914 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
1915 // Note: use isa_ptr() instead of isa_oopptr() here because
1916 // the _multianewarray functions return a TypeRawPtr.
1917 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
1918 nt = PointsToNode::JavaObject;
1919 }
1920 }
1921 add_node(n, nt, PointsToNode::UnknownEscape, false);
1922 }
1923 return;
1924 }
1925
1926 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1927 // ThreadLocal has RawPrt type.
1928 switch (n->Opcode()) {
1929 case Op_AddP:
1930 {
1931 add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
1932 break;
1933 }
1934 case Op_CastX2P:
1935 { // "Unsafe" memory access.
1936 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1937 break;
1938 }
1939 case Op_CastPP:
1940 case Op_CheckCastPP:
1941 case Op_EncodeP:
1942 case Op_DecodeN:
1943 {
1944 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
1945 int ti = n->in(1)->_idx;
1946 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
1947 if (nt == PointsToNode::UnknownType) {
1948 _delayed_worklist.push(n); // Process it later.
1949 break;
1950 } else if (nt == PointsToNode::JavaObject) {
1951 add_pointsto_edge(n->_idx, ti);
1952 } else {
1953 add_deferred_edge(n->_idx, ti);
1954 }
1955 _processed.set(n->_idx);
1956 break;
1957 }
1958 case Op_ConP:
1959 {
1960 // assume all pointer constants globally escape except for null
1961 PointsToNode::EscapeState es;
1962 if (phase->type(n) == TypePtr::NULL_PTR)
1963 es = PointsToNode::NoEscape;
1964 else
1965 es = PointsToNode::GlobalEscape;
1966
1967 add_node(n, PointsToNode::JavaObject, es, true);
1968 break;
1969 }
1970 case Op_ConN:
1971 {
1972 // assume all narrow oop constants globally escape except for null
1973 PointsToNode::EscapeState es;
1974 if (phase->type(n) == TypeNarrowOop::NULL_PTR)
1975 es = PointsToNode::NoEscape;
1976 else
1977 es = PointsToNode::GlobalEscape;
1978
1979 add_node(n, PointsToNode::JavaObject, es, true);
1980 break;
1981 }
1982 case Op_CreateEx:
1983 {
1984 // assume that all exception objects globally escape
1985 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1986 break;
1987 }
1988 case Op_LoadKlass:
1989 case Op_LoadNKlass:
1990 {
1991 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1992 break;
1993 }
1994 case Op_LoadP:
1995 case Op_LoadN:
1996 {
1997 const Type *t = phase->type(n);
1998 if (t->make_ptr() == NULL) {
1999 _processed.set(n->_idx);
2000 return;
2001 }
2002 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2003 break;
2004 }
2005 case Op_Parm:
2006 {
2007 _processed.set(n->_idx); // No need to redefine it state.
2008 uint con = n->as_Proj()->_con;
2009 if (con < TypeFunc::Parms)
2010 return;
2011 const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2012 if (t->isa_ptr() == NULL)
2013 return;
2014 // We have to assume all input parameters globally escape
2015 // (Note: passing 'false' since _processed is already set).
2016 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2017 break;
2018 }
2019 case Op_Phi:
2020 {
2021 const Type *t = n->as_Phi()->type();
2022 if (t->make_ptr() == NULL) {
2023 // nothing to do if not an oop or narrow oop
2024 _processed.set(n->_idx);
2025 return;
2026 }
2027 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2028 uint i;
2029 for (i = 1; i < n->req() ; i++) {
2030 Node* in = n->in(i);
2031 if (in == NULL)
2032 continue; // ignore NULL
2033 in = in->uncast();
2034 if (in->is_top() || in == n)
2035 continue; // ignore top or inputs which go back this node
2036 int ti = in->_idx;
2037 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2038 if (nt == PointsToNode::UnknownType) {
2039 break;
2040 } else if (nt == PointsToNode::JavaObject) {
2041 add_pointsto_edge(n->_idx, ti);
2042 } else {
2043 add_deferred_edge(n->_idx, ti);
2044 }
2045 }
2046 if (i >= n->req())
2047 _processed.set(n->_idx);
2048 else
2049 _delayed_worklist.push(n);
2050 break;
2051 }
2052 case Op_Proj:
2053 {
2054 // we are only interested in the result projection from a call
2055 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2056 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2057 process_call_result(n->as_Proj(), phase);
2058 if (!_processed.test(n->_idx)) {
2059 // The call's result may need to be processed later if the call
2060 // returns it's argument and the argument is not processed yet.
2061 _delayed_worklist.push(n);
2062 }
2063 } else {
2064 _processed.set(n->_idx);
2065 }
2066 break;
2067 }
2068 case Op_Return:
2069 {
2070 if( n->req() > TypeFunc::Parms &&
2071 phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2072 // Treat Return value as LocalVar with GlobalEscape escape state.
2073 add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2074 int ti = n->in(TypeFunc::Parms)->_idx;
2075 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2076 if (nt == PointsToNode::UnknownType) {
2077 _delayed_worklist.push(n); // Process it later.
2078 break;
2079 } else if (nt == PointsToNode::JavaObject) {
2080 add_pointsto_edge(n->_idx, ti);
2081 } else {
2082 add_deferred_edge(n->_idx, ti);
2083 }
2084 }
2085 _processed.set(n->_idx);
2086 break;
2087 }
2088 case Op_StoreP:
2089 case Op_StoreN:
2090 {
2091 const Type *adr_type = phase->type(n->in(MemNode::Address));
2092 adr_type = adr_type->make_ptr();
2093 if (adr_type->isa_oopptr()) {
2094 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2095 } else {
2096 Node* adr = n->in(MemNode::Address);
2097 if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2098 adr->in(AddPNode::Address)->is_Proj() &&
2099 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2100 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2101 // We are computing a raw address for a store captured
2102 // by an Initialize compute an appropriate address type.
2103 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2104 assert(offs != Type::OffsetBot, "offset must be a constant");
2105 } else {
2106 _processed.set(n->_idx);
2107 return;
2108 }
2109 }
2110 break;
2111 }
2112 case Op_StorePConditional:
2113 case Op_CompareAndSwapP:
2114 case Op_CompareAndSwapN:
2115 {
2116 const Type *adr_type = phase->type(n->in(MemNode::Address));
2117 adr_type = adr_type->make_ptr();
2118 if (adr_type->isa_oopptr()) {
2119 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2120 } else {
2121 _processed.set(n->_idx);
2122 return;
2123 }
2124 break;
2125 }
2126 case Op_ThreadLocal:
2127 {
2128 add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2129 break;
2130 }
2131 default:
2132 ;
2133 // nothing to do
2134 }
2135 return;
2136 }
2137
2138 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2139 uint n_idx = n->_idx;
2140
2141 // Don't set processed bit for AddP, LoadP, StoreP since
2142 // they may need more then one pass to process.
2143 if (_processed.test(n_idx))
2144 return; // No need to redefine node's state.
2145
2146 if (n->is_Call()) {
2147 CallNode *call = n->as_Call();
2148 process_call_arguments(call, phase);
2149 _processed.set(n_idx);
2150 return;
2151 }
2152
2153 switch (n->Opcode()) {
2154 case Op_AddP:
2155 {
2156 Node *base = get_addp_base(n);
2157 // Create a field edge to this node from everything base could point to.
2158 VectorSet ptset(Thread::current()->resource_area());
2159 PointsTo(ptset, base, phase);
2160 for( VectorSetI i(&ptset); i.test(); ++i ) {
2161 uint pt = i.elem;
2162 add_field_edge(pt, n_idx, address_offset(n, phase));
2163 }
2164 break;
2165 }
2166 case Op_CastX2P:
2167 {
2168 assert(false, "Op_CastX2P");
2169 break;
2170 }
2171 case Op_CastPP:
2172 case Op_CheckCastPP:
2173 case Op_EncodeP:
2174 case Op_DecodeN:
2175 {
2176 int ti = n->in(1)->_idx;
2177 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2178 add_pointsto_edge(n_idx, ti);
2179 } else {
2180 add_deferred_edge(n_idx, ti);
2181 }
2182 _processed.set(n_idx);
2183 break;
2184 }
2185 case Op_ConP:
2186 {
2187 assert(false, "Op_ConP");
2188 break;
2189 }
2190 case Op_ConN:
2191 {
2192 assert(false, "Op_ConN");
2193 break;
2194 }
2195 case Op_CreateEx:
2196 {
2197 assert(false, "Op_CreateEx");
2198 break;
2199 }
2200 case Op_LoadKlass:
2201 case Op_LoadNKlass:
2202 {
2203 assert(false, "Op_LoadKlass");
2204 break;
2205 }
2206 case Op_LoadP:
2207 case Op_LoadN:
2208 {
2209 const Type *t = phase->type(n);
2210 #ifdef ASSERT
2211 if (t->make_ptr() == NULL)
2212 assert(false, "Op_LoadP");
2213 #endif
2214
2215 Node* adr = n->in(MemNode::Address)->uncast();
2216 const Type *adr_type = phase->type(adr);
2217 Node* adr_base;
2218 if (adr->is_AddP()) {
2219 adr_base = get_addp_base(adr);
2220 } else {
2221 adr_base = adr;
2222 }
2223
2224 // For everything "adr_base" could point to, create a deferred edge from
2225 // this node to each field with the same offset.
2226 VectorSet ptset(Thread::current()->resource_area());
2227 PointsTo(ptset, adr_base, phase);
2228 int offset = address_offset(adr, phase);
2229 for( VectorSetI i(&ptset); i.test(); ++i ) {
2230 uint pt = i.elem;
2231 add_deferred_edge_to_fields(n_idx, pt, offset);
2232 }
2233 break;
2234 }
2235 case Op_Parm:
2236 {
2237 assert(false, "Op_Parm");
2238 break;
2239 }
2240 case Op_Phi:
2241 {
2242 #ifdef ASSERT
2243 const Type *t = n->as_Phi()->type();
2244 if (t->make_ptr() == NULL)
2245 assert(false, "Op_Phi");
2246 #endif
2247 for (uint i = 1; i < n->req() ; i++) {
2248 Node* in = n->in(i);
2249 if (in == NULL)
2250 continue; // ignore NULL
2251 in = in->uncast();
2252 if (in->is_top() || in == n)
2253 continue; // ignore top or inputs which go back this node
2254 int ti = in->_idx;
2255 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2256 assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2257 if (nt == PointsToNode::JavaObject) {
2258 add_pointsto_edge(n_idx, ti);
2259 } else {
2260 add_deferred_edge(n_idx, ti);
2261 }
2262 }
2263 _processed.set(n_idx);
2264 break;
2265 }
2266 case Op_Proj:
2267 {
2268 // we are only interested in the result projection from a call
2269 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2270 process_call_result(n->as_Proj(), phase);
2271 assert(_processed.test(n_idx), "all call results should be processed");
2272 } else {
2273 assert(false, "Op_Proj");
2274 }
2275 break;
2276 }
2277 case Op_Return:
2278 {
2279 #ifdef ASSERT
2280 if( n->req() <= TypeFunc::Parms ||
2281 !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2282 assert(false, "Op_Return");
2283 }
2284 #endif
2285 int ti = n->in(TypeFunc::Parms)->_idx;
2286 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2287 add_pointsto_edge(n_idx, ti);
2288 } else {
2289 add_deferred_edge(n_idx, ti);
2290 }
2291 _processed.set(n_idx);
2292 break;
2293 }
2294 case Op_StoreP:
2295 case Op_StoreN:
2296 case Op_StorePConditional:
2297 case Op_CompareAndSwapP:
2298 case Op_CompareAndSwapN:
2299 {
2300 Node *adr = n->in(MemNode::Address);
2301 const Type *adr_type = phase->type(adr)->make_ptr();
2302 #ifdef ASSERT
2303 if (!adr_type->isa_oopptr())
2304 assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2305 #endif
2306
2307 assert(adr->is_AddP(), "expecting an AddP");
2308 Node *adr_base = get_addp_base(adr);
2309 Node *val = n->in(MemNode::ValueIn)->uncast();
2310 // For everything "adr_base" could point to, create a deferred edge
2311 // to "val" from each field with the same offset.
2312 VectorSet ptset(Thread::current()->resource_area());
2313 PointsTo(ptset, adr_base, phase);
2314 for( VectorSetI i(&ptset); i.test(); ++i ) {
2315 uint pt = i.elem;
2316 add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2317 }
2318 break;
2319 }
2320 case Op_ThreadLocal:
2321 {
2322 assert(false, "Op_ThreadLocal");
2323 break;
2324 }
2325 default:
2326 ;
2327 // nothing to do
2328 }
2329 }
2330
2331 #ifndef PRODUCT
2332 void ConnectionGraph::dump() {
2333 PhaseGVN *igvn = _compile->initial_gvn();
2334 bool first = true;
2335
2336 uint size = nodes_size();
2337 for (uint ni = 0; ni < size; ni++) {
2338 PointsToNode *ptn = ptnode_adr(ni);
2339 PointsToNode::NodeType ptn_type = ptn->node_type();
2340
2341 if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2342 continue;
2343 PointsToNode::EscapeState es = escape_state(ptn->_node, igvn);
2344 if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2345 if (first) {
2346 tty->cr();
2347 tty->print("======== Connection graph for ");
2348 _compile->method()->print_short_name();
2349 tty->cr();
2350 first = false;
2351 }
2352 tty->print("%6d ", ni);
2353 ptn->dump();
2354 // Print all locals which reference this allocation
2355 for (uint li = ni; li < size; li++) {
2356 PointsToNode *ptn_loc = ptnode_adr(li);
2357 PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2358 if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2359 ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2360 ptnode_adr(li)->dump(false);
2361 }
2362 }
2363 if (Verbose) {
2364 // Print all fields which reference this allocation
2365 for (uint i = 0; i < ptn->edge_count(); i++) {
2366 uint ei = ptn->edge_target(i);
2367 ptnode_adr(ei)->dump(false);
2368 }
2369 }
2370 tty->cr();
2371 }
2372 }
2373 }
2374 #endif