1 /*
2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "libadt/vectset.hpp"
28 #include "memory/allocation.hpp"
29 #include "opto/c2compiler.hpp"
30 #include "opto/callnode.hpp"
31 #include "opto/cfgnode.hpp"
32 #include "opto/compile.hpp"
33 #include "opto/escape.hpp"
34 #include "opto/phaseX.hpp"
35 #include "opto/rootnode.hpp"
36
37 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
38 uint v = (targIdx << EdgeShift) + ((uint) et);
39 if (_edges == NULL) {
40 Arena *a = Compile::current()->comp_arena();
41 _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
42 }
43 _edges->append_if_missing(v);
44 }
45
46 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
47 uint v = (targIdx << EdgeShift) + ((uint) et);
48
49 _edges->remove(v);
50 }
51
52 #ifndef PRODUCT
53 static const char *node_type_names[] = {
54 "UnknownType",
55 "JavaObject",
56 "LocalVar",
57 "Field"
58 };
59
60 static const char *esc_names[] = {
61 "UnknownEscape",
62 "NoEscape",
63 "ArgEscape",
64 "GlobalEscape"
65 };
66
67 static const char *edge_type_suffix[] = {
68 "?", // UnknownEdge
69 "P", // PointsToEdge
70 "D", // DeferredEdge
71 "F" // FieldEdge
72 };
73
74 void PointsToNode::dump(bool print_state) const {
75 NodeType nt = node_type();
76 tty->print("%s ", node_type_names[(int) nt]);
77 if (print_state) {
78 EscapeState es = escape_state();
79 tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
80 }
81 tty->print("[[");
82 for (uint i = 0; i < edge_count(); i++) {
83 tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
84 }
85 tty->print("]] ");
86 if (_node == NULL)
87 tty->print_cr("<null>");
88 else
89 _node->dump();
90 }
91 #endif
92
93 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
94 _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
95 _processed(C->comp_arena()),
96 _collecting(true),
97 _compile(C),
98 _igvn(igvn),
99 _node_map(C->comp_arena()) {
100
101 _phantom_object = C->top()->_idx,
102 add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
103
104 // Add ConP(#NULL) and ConN(#NULL) nodes.
105 Node* oop_null = igvn->zerocon(T_OBJECT);
106 _oop_null = oop_null->_idx;
107 assert(_oop_null < C->unique(), "should be created already");
108 add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
109
110 if (UseCompressedOops) {
111 Node* noop_null = igvn->zerocon(T_NARROWOOP);
112 _noop_null = noop_null->_idx;
113 assert(_noop_null < C->unique(), "should be created already");
114 add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
115 }
116 }
117
118 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
119 PointsToNode *f = ptnode_adr(from_i);
120 PointsToNode *t = ptnode_adr(to_i);
121
122 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
123 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
124 assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
125 f->add_edge(to_i, PointsToNode::PointsToEdge);
126 }
127
128 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
129 PointsToNode *f = ptnode_adr(from_i);
130 PointsToNode *t = ptnode_adr(to_i);
131
132 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
133 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
134 assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
135 // don't add a self-referential edge, this can occur during removal of
136 // deferred edges
137 if (from_i != to_i)
138 f->add_edge(to_i, PointsToNode::DeferredEdge);
139 }
140
141 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
142 const Type *adr_type = phase->type(adr);
143 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
144 adr->in(AddPNode::Address)->is_Proj() &&
145 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
146 // We are computing a raw address for a store captured by an Initialize
147 // compute an appropriate address type. AddP cases #3 and #5 (see below).
148 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
149 assert(offs != Type::OffsetBot ||
150 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
151 "offset must be a constant or it is initialization of array");
152 return offs;
153 }
154 const TypePtr *t_ptr = adr_type->isa_ptr();
155 assert(t_ptr != NULL, "must be a pointer type");
156 return t_ptr->offset();
157 }
158
159 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
160 PointsToNode *f = ptnode_adr(from_i);
161 PointsToNode *t = ptnode_adr(to_i);
162
163 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
164 assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
165 assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
166 assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
167 t->set_offset(offset);
168
169 f->add_edge(to_i, PointsToNode::FieldEdge);
170 }
171
172 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
173 PointsToNode *npt = ptnode_adr(ni);
174 PointsToNode::EscapeState old_es = npt->escape_state();
175 if (es > old_es)
176 npt->set_escape_state(es);
177 }
178
179 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
180 PointsToNode::EscapeState es, bool done) {
181 PointsToNode* ptadr = ptnode_adr(n->_idx);
182 ptadr->_node = n;
183 ptadr->set_node_type(nt);
184
185 // inline set_escape_state(idx, es);
186 PointsToNode::EscapeState old_es = ptadr->escape_state();
187 if (es > old_es)
188 ptadr->set_escape_state(es);
189
190 if (done)
191 _processed.set(n->_idx);
192 }
193
194 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
195 uint idx = n->_idx;
196 PointsToNode::EscapeState es;
197
198 // If we are still collecting or there were no non-escaping allocations
199 // we don't know the answer yet
200 if (_collecting)
201 return PointsToNode::UnknownEscape;
202
203 // if the node was created after the escape computation, return
204 // UnknownEscape
205 if (idx >= nodes_size())
206 return PointsToNode::UnknownEscape;
207
208 es = ptnode_adr(idx)->escape_state();
209
210 // if we have already computed a value, return it
211 if (es != PointsToNode::UnknownEscape &&
212 ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
213 return es;
214
215 // PointsTo() calls n->uncast() which can return a new ideal node.
216 if (n->uncast()->_idx >= nodes_size())
217 return PointsToNode::UnknownEscape;
218
219 PointsToNode::EscapeState orig_es = es;
220
221 // compute max escape state of anything this node could point to
222 VectorSet ptset(Thread::current()->resource_area());
223 PointsTo(ptset, n);
224 for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
225 uint pt = i.elem;
226 PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
227 if (pes > es)
228 es = pes;
229 }
230 if (orig_es != es) {
231 // cache the computed escape state
232 assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
233 ptnode_adr(idx)->set_escape_state(es);
234 } // orig_es could be PointsToNode::UnknownEscape
235 return es;
236 }
237
238 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n) {
239 VectorSet visited(Thread::current()->resource_area());
240 GrowableArray<uint> worklist;
241
242 #ifdef ASSERT
243 Node *orig_n = n;
244 #endif
245
246 n = n->uncast();
247 PointsToNode* npt = ptnode_adr(n->_idx);
248
249 // If we have a JavaObject, return just that object
250 if (npt->node_type() == PointsToNode::JavaObject) {
251 ptset.set(n->_idx);
252 return;
253 }
254 #ifdef ASSERT
255 if (npt->_node == NULL) {
256 if (orig_n != n)
257 orig_n->dump();
258 n->dump();
259 assert(npt->_node != NULL, "unregistered node");
260 }
261 #endif
262 worklist.push(n->_idx);
263 while(worklist.length() > 0) {
264 int ni = worklist.pop();
265 if (visited.test_set(ni))
266 continue;
267
268 PointsToNode* pn = ptnode_adr(ni);
269 // ensure that all inputs of a Phi have been processed
270 assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
271
272 int edges_processed = 0;
273 uint e_cnt = pn->edge_count();
274 for (uint e = 0; e < e_cnt; e++) {
275 uint etgt = pn->edge_target(e);
276 PointsToNode::EdgeType et = pn->edge_type(e);
277 if (et == PointsToNode::PointsToEdge) {
278 ptset.set(etgt);
279 edges_processed++;
280 } else if (et == PointsToNode::DeferredEdge) {
281 worklist.push(etgt);
282 edges_processed++;
283 } else {
284 assert(false,"neither PointsToEdge or DeferredEdge");
285 }
286 }
287 if (edges_processed == 0) {
288 // no deferred or pointsto edges found. Assume the value was set
289 // outside this method. Add the phantom object to the pointsto set.
290 ptset.set(_phantom_object);
291 }
292 }
293 }
294
295 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
296 // This method is most expensive during ConnectionGraph construction.
297 // Reuse vectorSet and an additional growable array for deferred edges.
298 deferred_edges->clear();
299 visited->Clear();
300
301 visited->set(ni);
302 PointsToNode *ptn = ptnode_adr(ni);
303
304 // Mark current edges as visited and move deferred edges to separate array.
305 for (uint i = 0; i < ptn->edge_count(); ) {
306 uint t = ptn->edge_target(i);
307 #ifdef ASSERT
308 assert(!visited->test_set(t), "expecting no duplications");
309 #else
310 visited->set(t);
311 #endif
312 if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
313 ptn->remove_edge(t, PointsToNode::DeferredEdge);
314 deferred_edges->append(t);
315 } else {
316 i++;
317 }
318 }
319 for (int next = 0; next < deferred_edges->length(); ++next) {
320 uint t = deferred_edges->at(next);
321 PointsToNode *ptt = ptnode_adr(t);
322 uint e_cnt = ptt->edge_count();
323 for (uint e = 0; e < e_cnt; e++) {
324 uint etgt = ptt->edge_target(e);
325 if (visited->test_set(etgt))
326 continue;
327
328 PointsToNode::EdgeType et = ptt->edge_type(e);
329 if (et == PointsToNode::PointsToEdge) {
330 add_pointsto_edge(ni, etgt);
331 if(etgt == _phantom_object) {
332 // Special case - field set outside (globally escaping).
333 ptn->set_escape_state(PointsToNode::GlobalEscape);
334 }
335 } else if (et == PointsToNode::DeferredEdge) {
336 deferred_edges->append(etgt);
337 } else {
338 assert(false,"invalid connection graph");
339 }
340 }
341 }
342 }
343
344
345 // Add an edge to node given by "to_i" from any field of adr_i whose offset
346 // matches "offset" A deferred edge is added if to_i is a LocalVar, and
347 // a pointsto edge is added if it is a JavaObject
348
349 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
350 PointsToNode* an = ptnode_adr(adr_i);
351 PointsToNode* to = ptnode_adr(to_i);
352 bool deferred = (to->node_type() == PointsToNode::LocalVar);
353
354 for (uint fe = 0; fe < an->edge_count(); fe++) {
355 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
356 int fi = an->edge_target(fe);
357 PointsToNode* pf = ptnode_adr(fi);
358 int po = pf->offset();
359 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
360 if (deferred)
361 add_deferred_edge(fi, to_i);
362 else
363 add_pointsto_edge(fi, to_i);
364 }
365 }
366 }
367
368 // Add a deferred edge from node given by "from_i" to any field of adr_i
369 // whose offset matches "offset".
370 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
371 PointsToNode* an = ptnode_adr(adr_i);
372 for (uint fe = 0; fe < an->edge_count(); fe++) {
373 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
374 int fi = an->edge_target(fe);
375 PointsToNode* pf = ptnode_adr(fi);
376 int po = pf->offset();
377 if (pf->edge_count() == 0) {
378 // we have not seen any stores to this field, assume it was set outside this method
379 add_pointsto_edge(fi, _phantom_object);
380 }
381 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
382 add_deferred_edge(from_i, fi);
383 }
384 }
385 }
386
387 // Helper functions
388
389 static Node* get_addp_base(Node *addp) {
390 assert(addp->is_AddP(), "must be AddP");
391 //
392 // AddP cases for Base and Address inputs:
393 // case #1. Direct object's field reference:
394 // Allocate
395 // |
396 // Proj #5 ( oop result )
397 // |
398 // CheckCastPP (cast to instance type)
399 // | |
400 // AddP ( base == address )
401 //
402 // case #2. Indirect object's field reference:
403 // Phi
404 // |
405 // CastPP (cast to instance type)
406 // | |
407 // AddP ( base == address )
408 //
409 // case #3. Raw object's field reference for Initialize node:
410 // Allocate
411 // |
412 // Proj #5 ( oop result )
413 // top |
414 // \ |
415 // AddP ( base == top )
416 //
417 // case #4. Array's element reference:
418 // {CheckCastPP | CastPP}
419 // | | |
420 // | AddP ( array's element offset )
421 // | |
422 // AddP ( array's offset )
423 //
424 // case #5. Raw object's field reference for arraycopy stub call:
425 // The inline_native_clone() case when the arraycopy stub is called
426 // after the allocation before Initialize and CheckCastPP nodes.
427 // Allocate
428 // |
429 // Proj #5 ( oop result )
430 // | |
431 // AddP ( base == address )
432 //
433 // case #6. Constant Pool, ThreadLocal, CastX2P or
434 // Raw object's field reference:
435 // {ConP, ThreadLocal, CastX2P, raw Load}
436 // top |
437 // \ |
438 // AddP ( base == top )
439 //
440 // case #7. Klass's field reference.
441 // LoadKlass
442 // | |
443 // AddP ( base == address )
444 //
445 // case #8. narrow Klass's field reference.
446 // LoadNKlass
447 // |
448 // DecodeN
449 // | |
450 // AddP ( base == address )
451 //
452 Node *base = addp->in(AddPNode::Base)->uncast();
453 if (base->is_top()) { // The AddP case #3 and #6.
454 base = addp->in(AddPNode::Address)->uncast();
455 while (base->is_AddP()) {
456 // Case #6 (unsafe access) may have several chained AddP nodes.
457 assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
458 base = base->in(AddPNode::Address)->uncast();
459 }
460 assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
461 base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
462 (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
463 (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
464 }
465 return base;
466 }
467
468 static Node* find_second_addp(Node* addp, Node* n) {
469 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
470
471 Node* addp2 = addp->raw_out(0);
472 if (addp->outcnt() == 1 && addp2->is_AddP() &&
473 addp2->in(AddPNode::Base) == n &&
474 addp2->in(AddPNode::Address) == addp) {
475
476 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
477 //
478 // Find array's offset to push it on worklist first and
479 // as result process an array's element offset first (pushed second)
480 // to avoid CastPP for the array's offset.
481 // Otherwise the inserted CastPP (LocalVar) will point to what
482 // the AddP (Field) points to. Which would be wrong since
483 // the algorithm expects the CastPP has the same point as
484 // as AddP's base CheckCastPP (LocalVar).
485 //
486 // ArrayAllocation
487 // |
488 // CheckCastPP
489 // |
490 // memProj (from ArrayAllocation CheckCastPP)
491 // | ||
492 // | || Int (element index)
493 // | || | ConI (log(element size))
494 // | || | /
495 // | || LShift
496 // | || /
497 // | AddP (array's element offset)
498 // | |
499 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
500 // | / /
501 // AddP (array's offset)
502 // |
503 // Load/Store (memory operation on array's element)
504 //
505 return addp2;
506 }
507 return NULL;
508 }
509
510 //
511 // Adjust the type and inputs of an AddP which computes the
512 // address of a field of an instance
513 //
514 bool ConnectionGraph::split_AddP(Node *addp, Node *base, PhaseGVN *igvn) {
515 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
516 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
517 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
518 if (t == NULL) {
519 // We are computing a raw address for a store captured by an Initialize
520 // compute an appropriate address type (cases #3 and #5).
521 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
522 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
523 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
524 assert(offs != Type::OffsetBot, "offset must be a constant");
525 t = base_t->add_offset(offs)->is_oopptr();
526 }
527 int inst_id = base_t->instance_id();
528 assert(!t->is_known_instance() || t->instance_id() == inst_id,
529 "old type must be non-instance or match new type");
530
531 // The type 't' could be subclass of 'base_t'.
532 // As result t->offset() could be large then base_t's size and it will
533 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
534 // constructor verifies correctness of the offset.
535 //
536 // It could happened on subclass's branch (from the type profiling
537 // inlining) which was not eliminated during parsing since the exactness
538 // of the allocation type was not propagated to the subclass type check.
539 //
540 // Or the type 't' could be not related to 'base_t' at all.
541 // It could happened when CHA type is different from MDO type on a dead path
542 // (for example, from instanceof check) which is not collapsed during parsing.
543 //
544 // Do nothing for such AddP node and don't process its users since
545 // this code branch will go away.
546 //
547 if (!t->is_known_instance() &&
548 !base_t->klass()->is_subtype_of(t->klass())) {
549 return false; // bail out
550 }
551
552 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
553 // Do NOT remove the next line: ensure a new alias index is allocated
554 // for the instance type. Note: C++ will not remove it since the call
555 // has side effect.
556 int alias_idx = _compile->get_alias_index(tinst);
557 igvn->set_type(addp, tinst);
558 // record the allocation in the node map
559 assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
560 set_map(addp->_idx, get_map(base->_idx));
561
562 // Set addp's Base and Address to 'base'.
563 Node *abase = addp->in(AddPNode::Base);
564 Node *adr = addp->in(AddPNode::Address);
565 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
566 adr->in(0)->_idx == (uint)inst_id) {
567 // Skip AddP cases #3 and #5.
568 } else {
569 assert(!abase->is_top(), "sanity"); // AddP case #3
570 if (abase != base) {
571 igvn->hash_delete(addp);
572 addp->set_req(AddPNode::Base, base);
573 if (abase == adr) {
574 addp->set_req(AddPNode::Address, base);
575 } else {
576 // AddP case #4 (adr is array's element offset AddP node)
577 #ifdef ASSERT
578 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
579 assert(adr->is_AddP() && atype != NULL &&
580 atype->instance_id() == inst_id, "array's element offset should be processed first");
581 #endif
582 }
583 igvn->hash_insert(addp);
584 }
585 }
586 // Put on IGVN worklist since at least addp's type was changed above.
587 record_for_optimizer(addp);
588 return true;
589 }
590
591 //
592 // Create a new version of orig_phi if necessary. Returns either the newly
593 // created phi or an existing phi. Sets create_new to indicate wheter a new
594 // phi was created. Cache the last newly created phi in the node map.
595 //
596 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created) {
597 Compile *C = _compile;
598 new_created = false;
599 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
600 // nothing to do if orig_phi is bottom memory or matches alias_idx
601 if (phi_alias_idx == alias_idx) {
602 return orig_phi;
603 }
604 // Have we recently created a Phi for this alias index?
605 PhiNode *result = get_map_phi(orig_phi->_idx);
606 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
607 return result;
608 }
609 // Previous check may fail when the same wide memory Phi was split into Phis
610 // for different memory slices. Search all Phis for this region.
611 if (result != NULL) {
612 Node* region = orig_phi->in(0);
613 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
614 Node* phi = region->fast_out(i);
615 if (phi->is_Phi() &&
616 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
617 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
618 return phi->as_Phi();
619 }
620 }
621 }
622 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
623 if (C->do_escape_analysis() == true && !C->failing()) {
624 // Retry compilation without escape analysis.
625 // If this is the first failure, the sentinel string will "stick"
626 // to the Compile object, and the C2Compiler will see it and retry.
627 C->record_failure(C2Compiler::retry_no_escape_analysis());
628 }
629 return NULL;
630 }
631 orig_phi_worklist.append_if_missing(orig_phi);
632 const TypePtr *atype = C->get_adr_type(alias_idx);
633 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
634 C->copy_node_notes_to(result, orig_phi);
635 igvn->set_type(result, result->bottom_type());
636 record_for_optimizer(result);
637
638 debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
639 assert(pn == NULL || pn == orig_phi, "wrong node");
640 set_map(orig_phi->_idx, result);
641 ptnode_adr(orig_phi->_idx)->_node = orig_phi;
642
643 new_created = true;
644 return result;
645 }
646
647 //
648 // Return a new version of Memory Phi "orig_phi" with the inputs having the
649 // specified alias index.
650 //
651 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
652
653 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
654 Compile *C = _compile;
655 bool new_phi_created;
656 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
657 if (!new_phi_created) {
658 return result;
659 }
660
661 GrowableArray<PhiNode *> phi_list;
662 GrowableArray<uint> cur_input;
663
664 PhiNode *phi = orig_phi;
665 uint idx = 1;
666 bool finished = false;
667 while(!finished) {
668 while (idx < phi->req()) {
669 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
670 if (mem != NULL && mem->is_Phi()) {
671 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
672 if (new_phi_created) {
673 // found an phi for which we created a new split, push current one on worklist and begin
674 // processing new one
675 phi_list.push(phi);
676 cur_input.push(idx);
677 phi = mem->as_Phi();
678 result = newphi;
679 idx = 1;
680 continue;
681 } else {
682 mem = newphi;
683 }
684 }
685 if (C->failing()) {
686 return NULL;
687 }
688 result->set_req(idx++, mem);
689 }
690 #ifdef ASSERT
691 // verify that the new Phi has an input for each input of the original
692 assert( phi->req() == result->req(), "must have same number of inputs.");
693 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
694 #endif
695 // Check if all new phi's inputs have specified alias index.
696 // Otherwise use old phi.
697 for (uint i = 1; i < phi->req(); i++) {
698 Node* in = result->in(i);
699 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
700 }
701 // we have finished processing a Phi, see if there are any more to do
702 finished = (phi_list.length() == 0 );
703 if (!finished) {
704 phi = phi_list.pop();
705 idx = cur_input.pop();
706 PhiNode *prev_result = get_map_phi(phi->_idx);
707 prev_result->set_req(idx++, result);
708 result = prev_result;
709 }
710 }
711 return result;
712 }
713
714
715 //
716 // The next methods are derived from methods in MemNode.
717 //
718 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
719 Node *mem = mmem;
720 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
721 // means an array I have not precisely typed yet. Do not do any
722 // alias stuff with it any time soon.
723 if( toop->base() != Type::AnyPtr &&
724 !(toop->klass() != NULL &&
725 toop->klass()->is_java_lang_Object() &&
726 toop->offset() == Type::OffsetBot) ) {
727 mem = mmem->memory_at(alias_idx);
728 // Update input if it is progress over what we have now
729 }
730 return mem;
731 }
732
733 //
734 // Move memory users to their memory slices.
735 //
736 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *igvn) {
737 Compile* C = _compile;
738
739 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
740 assert(tp != NULL, "ptr type");
741 int alias_idx = C->get_alias_index(tp);
742 int general_idx = C->get_general_index(alias_idx);
743
744 // Move users first
745 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
746 Node* use = n->fast_out(i);
747 if (use->is_MergeMem()) {
748 MergeMemNode* mmem = use->as_MergeMem();
749 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
750 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
751 continue; // Nothing to do
752 }
753 // Replace previous general reference to mem node.
754 uint orig_uniq = C->unique();
755 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
756 assert(orig_uniq == C->unique(), "no new nodes");
757 mmem->set_memory_at(general_idx, m);
758 --imax;
759 --i;
760 } else if (use->is_MemBar()) {
761 assert(!use->is_Initialize(), "initializing stores should not be moved");
762 if (use->req() > MemBarNode::Precedent &&
763 use->in(MemBarNode::Precedent) == n) {
764 // Don't move related membars.
765 record_for_optimizer(use);
766 continue;
767 }
768 tp = use->as_MemBar()->adr_type()->isa_ptr();
769 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
770 alias_idx == general_idx) {
771 continue; // Nothing to do
772 }
773 // Move to general memory slice.
774 uint orig_uniq = C->unique();
775 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
776 assert(orig_uniq == C->unique(), "no new nodes");
777 igvn->hash_delete(use);
778 imax -= use->replace_edge(n, m);
779 igvn->hash_insert(use);
780 record_for_optimizer(use);
781 --i;
782 #ifdef ASSERT
783 } else if (use->is_Mem()) {
784 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
785 // Don't move related cardmark.
786 continue;
787 }
788 // Memory nodes should have new memory input.
789 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
790 assert(tp != NULL, "ptr type");
791 int idx = C->get_alias_index(tp);
792 assert(get_map(use->_idx) != NULL || idx == alias_idx,
793 "Following memory nodes should have new memory input or be on the same memory slice");
794 } else if (use->is_Phi()) {
795 // Phi nodes should be split and moved already.
796 tp = use->as_Phi()->adr_type()->isa_ptr();
797 assert(tp != NULL, "ptr type");
798 int idx = C->get_alias_index(tp);
799 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
800 } else {
801 use->dump();
802 assert(false, "should not be here");
803 #endif
804 }
805 }
806 }
807
808 //
809 // Search memory chain of "mem" to find a MemNode whose address
810 // is the specified alias index.
811 //
812 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *phase) {
813 if (orig_mem == NULL)
814 return orig_mem;
815 Compile* C = phase->C;
816 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
817 bool is_instance = (toop != NULL) && toop->is_known_instance();
818 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
819 Node *prev = NULL;
820 Node *result = orig_mem;
821 while (prev != result) {
822 prev = result;
823 if (result == start_mem)
824 break; // hit one of our sentinels
825 if (result->is_Mem()) {
826 const Type *at = phase->type(result->in(MemNode::Address));
827 if (at != Type::TOP) {
828 assert (at->isa_ptr() != NULL, "pointer type required.");
829 int idx = C->get_alias_index(at->is_ptr());
830 if (idx == alias_idx)
831 break;
832 }
833 result = result->in(MemNode::Memory);
834 }
835 if (!is_instance)
836 continue; // don't search further for non-instance types
837 // skip over a call which does not affect this memory slice
838 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
839 Node *proj_in = result->in(0);
840 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
841 break; // hit one of our sentinels
842 } else if (proj_in->is_Call()) {
843 CallNode *call = proj_in->as_Call();
844 if (!call->may_modify(toop, phase)) {
845 result = call->in(TypeFunc::Memory);
846 }
847 } else if (proj_in->is_Initialize()) {
848 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
849 // Stop if this is the initialization for the object instance which
850 // which contains this memory slice, otherwise skip over it.
851 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
852 result = proj_in->in(TypeFunc::Memory);
853 }
854 } else if (proj_in->is_MemBar()) {
855 result = proj_in->in(TypeFunc::Memory);
856 }
857 } else if (result->is_MergeMem()) {
858 MergeMemNode *mmem = result->as_MergeMem();
859 result = step_through_mergemem(mmem, alias_idx, toop);
860 if (result == mmem->base_memory()) {
861 // Didn't find instance memory, search through general slice recursively.
862 result = mmem->memory_at(C->get_general_index(alias_idx));
863 result = find_inst_mem(result, alias_idx, orig_phis, phase);
864 if (C->failing()) {
865 return NULL;
866 }
867 mmem->set_memory_at(alias_idx, result);
868 }
869 } else if (result->is_Phi() &&
870 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
871 Node *un = result->as_Phi()->unique_input(phase);
872 if (un != NULL) {
873 orig_phis.append_if_missing(result->as_Phi());
874 result = un;
875 } else {
876 break;
877 }
878 } else if (result->is_ClearArray()) {
879 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
880 // Can not bypass initialization of the instance
881 // we are looking for.
882 break;
883 }
884 // Otherwise skip it (the call updated 'result' value).
885 } else if (result->Opcode() == Op_SCMemProj) {
886 assert(result->in(0)->is_LoadStore(), "sanity");
887 const Type *at = phase->type(result->in(0)->in(MemNode::Address));
888 if (at != Type::TOP) {
889 assert (at->isa_ptr() != NULL, "pointer type required.");
890 int idx = C->get_alias_index(at->is_ptr());
891 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
892 break;
893 }
894 result = result->in(0)->in(MemNode::Memory);
895 }
896 }
897 if (result->is_Phi()) {
898 PhiNode *mphi = result->as_Phi();
899 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
900 const TypePtr *t = mphi->adr_type();
901 if (C->get_alias_index(t) != alias_idx) {
902 // Create a new Phi with the specified alias index type.
903 result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
904 } else if (!is_instance) {
905 // Push all non-instance Phis on the orig_phis worklist to update inputs
906 // during Phase 4 if needed.
907 orig_phis.append_if_missing(mphi);
908 }
909 }
910 // the result is either MemNode, PhiNode, InitializeNode.
911 return result;
912 }
913
914 //
915 // Convert the types of unescaped object to instance types where possible,
916 // propagate the new type information through the graph, and update memory
917 // edges and MergeMem inputs to reflect the new type.
918 //
919 // We start with allocations (and calls which may be allocations) on alloc_worklist.
920 // The processing is done in 4 phases:
921 //
922 // Phase 1: Process possible allocations from alloc_worklist. Create instance
923 // types for the CheckCastPP for allocations where possible.
924 // Propagate the the new types through users as follows:
925 // casts and Phi: push users on alloc_worklist
926 // AddP: cast Base and Address inputs to the instance type
927 // push any AddP users on alloc_worklist and push any memnode
928 // users onto memnode_worklist.
929 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
930 // search the Memory chain for a store with the appropriate type
931 // address type. If a Phi is found, create a new version with
932 // the appropriate memory slices from each of the Phi inputs.
933 // For stores, process the users as follows:
934 // MemNode: push on memnode_worklist
935 // MergeMem: push on mergemem_worklist
936 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
937 // moving the first node encountered of each instance type to the
938 // the input corresponding to its alias index.
939 // appropriate memory slice.
940 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
941 //
942 // In the following example, the CheckCastPP nodes are the cast of allocation
943 // results and the allocation of node 29 is unescaped and eligible to be an
944 // instance type.
945 //
946 // We start with:
947 //
948 // 7 Parm #memory
949 // 10 ConI "12"
950 // 19 CheckCastPP "Foo"
951 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
952 // 29 CheckCastPP "Foo"
953 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
954 //
955 // 40 StoreP 25 7 20 ... alias_index=4
956 // 50 StoreP 35 40 30 ... alias_index=4
957 // 60 StoreP 45 50 20 ... alias_index=4
958 // 70 LoadP _ 60 30 ... alias_index=4
959 // 80 Phi 75 50 60 Memory alias_index=4
960 // 90 LoadP _ 80 30 ... alias_index=4
961 // 100 LoadP _ 80 20 ... alias_index=4
962 //
963 //
964 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
965 // and creating a new alias index for node 30. This gives:
966 //
967 // 7 Parm #memory
968 // 10 ConI "12"
969 // 19 CheckCastPP "Foo"
970 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
971 // 29 CheckCastPP "Foo" iid=24
972 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
973 //
974 // 40 StoreP 25 7 20 ... alias_index=4
975 // 50 StoreP 35 40 30 ... alias_index=6
976 // 60 StoreP 45 50 20 ... alias_index=4
977 // 70 LoadP _ 60 30 ... alias_index=6
978 // 80 Phi 75 50 60 Memory alias_index=4
979 // 90 LoadP _ 80 30 ... alias_index=6
980 // 100 LoadP _ 80 20 ... alias_index=4
981 //
982 // In phase 2, new memory inputs are computed for the loads and stores,
983 // And a new version of the phi is created. In phase 4, the inputs to
984 // node 80 are updated and then the memory nodes are updated with the
985 // values computed in phase 2. This results in:
986 //
987 // 7 Parm #memory
988 // 10 ConI "12"
989 // 19 CheckCastPP "Foo"
990 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
991 // 29 CheckCastPP "Foo" iid=24
992 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
993 //
994 // 40 StoreP 25 7 20 ... alias_index=4
995 // 50 StoreP 35 7 30 ... alias_index=6
996 // 60 StoreP 45 40 20 ... alias_index=4
997 // 70 LoadP _ 50 30 ... alias_index=6
998 // 80 Phi 75 40 60 Memory alias_index=4
999 // 120 Phi 75 50 50 Memory alias_index=6
1000 // 90 LoadP _ 120 30 ... alias_index=6
1001 // 100 LoadP _ 80 20 ... alias_index=4
1002 //
1003 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
1004 GrowableArray<Node *> memnode_worklist;
1005 GrowableArray<PhiNode *> orig_phis;
1006
1007 PhaseGVN *igvn = _igvn;
1008 uint new_index_start = (uint) _compile->num_alias_types();
1009 Arena* arena = Thread::current()->resource_area();
1010 VectorSet visited(arena);
1011 VectorSet ptset(arena);
1012
1013
1014 // Phase 1: Process possible allocations from alloc_worklist.
1015 // Create instance types for the CheckCastPP for allocations where possible.
1016 //
1017 // (Note: don't forget to change the order of the second AddP node on
1018 // the alloc_worklist if the order of the worklist processing is changed,
1019 // see the comment in find_second_addp().)
1020 //
1021 while (alloc_worklist.length() != 0) {
1022 Node *n = alloc_worklist.pop();
1023 uint ni = n->_idx;
1024 const TypeOopPtr* tinst = NULL;
1025 if (n->is_Call()) {
1026 CallNode *alloc = n->as_Call();
1027 // copy escape information to call node
1028 PointsToNode* ptn = ptnode_adr(alloc->_idx);
1029 PointsToNode::EscapeState es = escape_state(alloc);
1030 // We have an allocation or call which returns a Java object,
1031 // see if it is unescaped.
1032 if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
1033 continue;
1034
1035 // Find CheckCastPP for the allocate or for the return value of a call
1036 n = alloc->result_cast();
1037 if (n == NULL) { // No uses except Initialize node
1038 if (alloc->is_Allocate()) {
1039 // Set the scalar_replaceable flag for allocation
1040 // so it could be eliminated if it has no uses.
1041 alloc->as_Allocate()->_is_scalar_replaceable = true;
1042 }
1043 continue;
1044 }
1045 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1046 assert(!alloc->is_Allocate(), "allocation should have unique type");
1047 continue;
1048 }
1049
1050 // The inline code for Object.clone() casts the allocation result to
1051 // java.lang.Object and then to the actual type of the allocated
1052 // object. Detect this case and use the second cast.
1053 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
1054 // the allocation result is cast to java.lang.Object and then
1055 // to the actual Array type.
1056 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
1057 && (alloc->is_AllocateArray() ||
1058 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
1059 Node *cast2 = NULL;
1060 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1061 Node *use = n->fast_out(i);
1062 if (use->is_CheckCastPP()) {
1063 cast2 = use;
1064 break;
1065 }
1066 }
1067 if (cast2 != NULL) {
1068 n = cast2;
1069 } else {
1070 // Non-scalar replaceable if the allocation type is unknown statically
1071 // (reflection allocation), the object can't be restored during
1072 // deoptimization without precise type.
1073 continue;
1074 }
1075 }
1076 if (alloc->is_Allocate()) {
1077 // Set the scalar_replaceable flag for allocation
1078 // so it could be eliminated.
1079 alloc->as_Allocate()->_is_scalar_replaceable = true;
1080 }
1081 set_escape_state(n->_idx, es);
1082 // in order for an object to be scalar-replaceable, it must be:
1083 // - a direct allocation (not a call returning an object)
1084 // - non-escaping
1085 // - eligible to be a unique type
1086 // - not determined to be ineligible by escape analysis
1087 assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1088 ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1089 set_map(alloc->_idx, n);
1090 set_map(n->_idx, alloc);
1091 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1092 if (t == NULL)
1093 continue; // not a TypeInstPtr
1094 tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1095 igvn->hash_delete(n);
1096 igvn->set_type(n, tinst);
1097 n->raise_bottom_type(tinst);
1098 igvn->hash_insert(n);
1099 record_for_optimizer(n);
1100 if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
1101 (t->isa_instptr() || t->isa_aryptr())) {
1102
1103 // First, put on the worklist all Field edges from Connection Graph
1104 // which is more accurate then putting immediate users from Ideal Graph.
1105 for (uint e = 0; e < ptn->edge_count(); e++) {
1106 Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1107 assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
1108 "only AddP nodes are Field edges in CG");
1109 if (use->outcnt() > 0) { // Don't process dead nodes
1110 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1111 if (addp2 != NULL) {
1112 assert(alloc->is_AllocateArray(),"array allocation was expected");
1113 alloc_worklist.append_if_missing(addp2);
1114 }
1115 alloc_worklist.append_if_missing(use);
1116 }
1117 }
1118
1119 // An allocation may have an Initialize which has raw stores. Scan
1120 // the users of the raw allocation result and push AddP users
1121 // on alloc_worklist.
1122 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1123 assert (raw_result != NULL, "must have an allocation result");
1124 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1125 Node *use = raw_result->fast_out(i);
1126 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1127 Node* addp2 = find_second_addp(use, raw_result);
1128 if (addp2 != NULL) {
1129 assert(alloc->is_AllocateArray(),"array allocation was expected");
1130 alloc_worklist.append_if_missing(addp2);
1131 }
1132 alloc_worklist.append_if_missing(use);
1133 } else if (use->is_MemBar()) {
1134 memnode_worklist.append_if_missing(use);
1135 }
1136 }
1137 }
1138 } else if (n->is_AddP()) {
1139 ptset.Clear();
1140 PointsTo(ptset, get_addp_base(n));
1141 assert(ptset.Size() == 1, "AddP address is unique");
1142 uint elem = ptset.getelem(); // Allocation node's index
1143 if (elem == _phantom_object) {
1144 assert(false, "escaped allocation");
1145 continue; // Assume the value was set outside this method.
1146 }
1147 Node *base = get_map(elem); // CheckCastPP node
1148 if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1149 tinst = igvn->type(base)->isa_oopptr();
1150 } else if (n->is_Phi() ||
1151 n->is_CheckCastPP() ||
1152 n->is_EncodeP() ||
1153 n->is_DecodeN() ||
1154 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1155 if (visited.test_set(n->_idx)) {
1156 assert(n->is_Phi(), "loops only through Phi's");
1157 continue; // already processed
1158 }
1159 ptset.Clear();
1160 PointsTo(ptset, n);
1161 if (ptset.Size() == 1) {
1162 uint elem = ptset.getelem(); // Allocation node's index
1163 if (elem == _phantom_object) {
1164 assert(false, "escaped allocation");
1165 continue; // Assume the value was set outside this method.
1166 }
1167 Node *val = get_map(elem); // CheckCastPP node
1168 TypeNode *tn = n->as_Type();
1169 tinst = igvn->type(val)->isa_oopptr();
1170 assert(tinst != NULL && tinst->is_known_instance() &&
1171 (uint)tinst->instance_id() == elem , "instance type expected.");
1172
1173 const Type *tn_type = igvn->type(tn);
1174 const TypeOopPtr *tn_t;
1175 if (tn_type->isa_narrowoop()) {
1176 tn_t = tn_type->make_ptr()->isa_oopptr();
1177 } else {
1178 tn_t = tn_type->isa_oopptr();
1179 }
1180
1181 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1182 if (tn_type->isa_narrowoop()) {
1183 tn_type = tinst->make_narrowoop();
1184 } else {
1185 tn_type = tinst;
1186 }
1187 igvn->hash_delete(tn);
1188 igvn->set_type(tn, tn_type);
1189 tn->set_type(tn_type);
1190 igvn->hash_insert(tn);
1191 record_for_optimizer(n);
1192 } else {
1193 assert(tn_type == TypePtr::NULL_PTR ||
1194 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
1195 "unexpected type");
1196 continue; // Skip dead path with different type
1197 }
1198 }
1199 } else {
1200 debug_only(n->dump();)
1201 assert(false, "EA: unexpected node");
1202 continue;
1203 }
1204 // push allocation's users on appropriate worklist
1205 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1206 Node *use = n->fast_out(i);
1207 if(use->is_Mem() && use->in(MemNode::Address) == n) {
1208 // Load/store to instance's field
1209 memnode_worklist.append_if_missing(use);
1210 } else if (use->is_MemBar()) {
1211 memnode_worklist.append_if_missing(use);
1212 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1213 Node* addp2 = find_second_addp(use, n);
1214 if (addp2 != NULL) {
1215 alloc_worklist.append_if_missing(addp2);
1216 }
1217 alloc_worklist.append_if_missing(use);
1218 } else if (use->is_Phi() ||
1219 use->is_CheckCastPP() ||
1220 use->is_EncodeP() ||
1221 use->is_DecodeN() ||
1222 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1223 alloc_worklist.append_if_missing(use);
1224 #ifdef ASSERT
1225 } else if (use->is_Mem()) {
1226 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
1227 } else if (use->is_MergeMem()) {
1228 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1229 } else if (use->is_SafePoint()) {
1230 // Look for MergeMem nodes for calls which reference unique allocation
1231 // (through CheckCastPP nodes) even for debug info.
1232 Node* m = use->in(TypeFunc::Memory);
1233 if (m->is_MergeMem()) {
1234 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1235 }
1236 } else {
1237 uint op = use->Opcode();
1238 if (!(op == Op_CmpP || op == Op_Conv2B ||
1239 op == Op_CastP2X || op == Op_StoreCM ||
1240 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1241 op == Op_StrEquals || op == Op_StrIndexOf)) {
1242 n->dump();
1243 use->dump();
1244 assert(false, "EA: missing allocation reference path");
1245 }
1246 #endif
1247 }
1248 }
1249
1250 }
1251 // New alias types were created in split_AddP().
1252 uint new_index_end = (uint) _compile->num_alias_types();
1253
1254 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1255 // compute new values for Memory inputs (the Memory inputs are not
1256 // actually updated until phase 4.)
1257 if (memnode_worklist.length() == 0)
1258 return; // nothing to do
1259
1260 while (memnode_worklist.length() != 0) {
1261 Node *n = memnode_worklist.pop();
1262 if (visited.test_set(n->_idx))
1263 continue;
1264 if (n->is_Phi() || n->is_ClearArray()) {
1265 // we don't need to do anything, but the users must be pushed
1266 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1267 // we don't need to do anything, but the users must be pushed
1268 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1269 if (n == NULL)
1270 continue;
1271 } else {
1272 assert(n->is_Mem(), "memory node required.");
1273 Node *addr = n->in(MemNode::Address);
1274 const Type *addr_t = igvn->type(addr);
1275 if (addr_t == Type::TOP)
1276 continue;
1277 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1278 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1279 assert ((uint)alias_idx < new_index_end, "wrong alias index");
1280 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1281 if (_compile->failing()) {
1282 return;
1283 }
1284 if (mem != n->in(MemNode::Memory)) {
1285 // We delay the memory edge update since we need old one in
1286 // MergeMem code below when instances memory slices are separated.
1287 debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1288 assert(pn == NULL || pn == n, "wrong node");
1289 set_map(n->_idx, mem);
1290 ptnode_adr(n->_idx)->_node = n;
1291 }
1292 if (n->is_Load()) {
1293 continue; // don't push users
1294 } else if (n->is_LoadStore()) {
1295 // get the memory projection
1296 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1297 Node *use = n->fast_out(i);
1298 if (use->Opcode() == Op_SCMemProj) {
1299 n = use;
1300 break;
1301 }
1302 }
1303 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1304 }
1305 }
1306 // push user on appropriate worklist
1307 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1308 Node *use = n->fast_out(i);
1309 if (use->is_Phi() || use->is_ClearArray()) {
1310 memnode_worklist.append_if_missing(use);
1311 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1312 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
1313 continue;
1314 memnode_worklist.append_if_missing(use);
1315 } else if (use->is_MemBar()) {
1316 memnode_worklist.append_if_missing(use);
1317 #ifdef ASSERT
1318 } else if(use->is_Mem()) {
1319 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
1320 } else if (use->is_MergeMem()) {
1321 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1322 } else {
1323 uint op = use->Opcode();
1324 if (!(op == Op_StoreCM ||
1325 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
1326 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
1327 op == Op_AryEq || op == Op_StrComp ||
1328 op == Op_StrEquals || op == Op_StrIndexOf)) {
1329 n->dump();
1330 use->dump();
1331 assert(false, "EA: missing memory path");
1332 }
1333 #endif
1334 }
1335 }
1336 }
1337
1338 // Phase 3: Process MergeMem nodes from mergemem_worklist.
1339 // Walk each memory slice moving the first node encountered of each
1340 // instance type to the the input corresponding to its alias index.
1341 uint length = _mergemem_worklist.length();
1342 for( uint next = 0; next < length; ++next ) {
1343 MergeMemNode* nmm = _mergemem_worklist.at(next);
1344 assert(!visited.test_set(nmm->_idx), "should not be visited before");
1345 // Note: we don't want to use MergeMemStream here because we only want to
1346 // scan inputs which exist at the start, not ones we add during processing.
1347 // Note 2: MergeMem may already contains instance memory slices added
1348 // during find_inst_mem() call when memory nodes were processed above.
1349 igvn->hash_delete(nmm);
1350 uint nslices = nmm->req();
1351 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1352 Node* mem = nmm->in(i);
1353 Node* cur = NULL;
1354 if (mem == NULL || mem->is_top())
1355 continue;
1356 // First, update mergemem by moving memory nodes to corresponding slices
1357 // if their type became more precise since this mergemem was created.
1358 while (mem->is_Mem()) {
1359 const Type *at = igvn->type(mem->in(MemNode::Address));
1360 if (at != Type::TOP) {
1361 assert (at->isa_ptr() != NULL, "pointer type required.");
1362 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1363 if (idx == i) {
1364 if (cur == NULL)
1365 cur = mem;
1366 } else {
1367 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1368 nmm->set_memory_at(idx, mem);
1369 }
1370 }
1371 }
1372 mem = mem->in(MemNode::Memory);
1373 }
1374 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1375 // Find any instance of the current type if we haven't encountered
1376 // already a memory slice of the instance along the memory chain.
1377 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1378 if((uint)_compile->get_general_index(ni) == i) {
1379 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1380 if (nmm->is_empty_memory(m)) {
1381 Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1382 if (_compile->failing()) {
1383 return;
1384 }
1385 nmm->set_memory_at(ni, result);
1386 }
1387 }
1388 }
1389 }
1390 // Find the rest of instances values
1391 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1392 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
1393 Node* result = step_through_mergemem(nmm, ni, tinst);
1394 if (result == nmm->base_memory()) {
1395 // Didn't find instance memory, search through general slice recursively.
1396 result = nmm->memory_at(_compile->get_general_index(ni));
1397 result = find_inst_mem(result, ni, orig_phis, igvn);
1398 if (_compile->failing()) {
1399 return;
1400 }
1401 nmm->set_memory_at(ni, result);
1402 }
1403 }
1404 igvn->hash_insert(nmm);
1405 record_for_optimizer(nmm);
1406 }
1407
1408 // Phase 4: Update the inputs of non-instance memory Phis and
1409 // the Memory input of memnodes
1410 // First update the inputs of any non-instance Phi's from
1411 // which we split out an instance Phi. Note we don't have
1412 // to recursively process Phi's encounted on the input memory
1413 // chains as is done in split_memory_phi() since they will
1414 // also be processed here.
1415 for (int j = 0; j < orig_phis.length(); j++) {
1416 PhiNode *phi = orig_phis.at(j);
1417 int alias_idx = _compile->get_alias_index(phi->adr_type());
1418 igvn->hash_delete(phi);
1419 for (uint i = 1; i < phi->req(); i++) {
1420 Node *mem = phi->in(i);
1421 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1422 if (_compile->failing()) {
1423 return;
1424 }
1425 if (mem != new_mem) {
1426 phi->set_req(i, new_mem);
1427 }
1428 }
1429 igvn->hash_insert(phi);
1430 record_for_optimizer(phi);
1431 }
1432
1433 // Update the memory inputs of MemNodes with the value we computed
1434 // in Phase 2 and move stores memory users to corresponding memory slices.
1435 #ifdef ASSERT
1436 visited.Clear();
1437 Node_Stack old_mems(arena, _compile->unique() >> 2);
1438 #endif
1439 for (uint i = 0; i < nodes_size(); i++) {
1440 Node *nmem = get_map(i);
1441 if (nmem != NULL) {
1442 Node *n = ptnode_adr(i)->_node;
1443 assert(n != NULL, "sanity");
1444 if (n->is_Mem()) {
1445 #ifdef ASSERT
1446 Node* old_mem = n->in(MemNode::Memory);
1447 if (!visited.test_set(old_mem->_idx)) {
1448 old_mems.push(old_mem, old_mem->outcnt());
1449 }
1450 #endif
1451 assert(n->in(MemNode::Memory) != nmem, "sanity");
1452 if (!n->is_Load()) {
1453 // Move memory users of a store first.
1454 move_inst_mem(n, orig_phis, igvn);
1455 }
1456 // Now update memory input
1457 igvn->hash_delete(n);
1458 n->set_req(MemNode::Memory, nmem);
1459 igvn->hash_insert(n);
1460 record_for_optimizer(n);
1461 } else {
1462 assert(n->is_Allocate() || n->is_CheckCastPP() ||
1463 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1464 }
1465 }
1466 }
1467 #ifdef ASSERT
1468 // Verify that memory was split correctly
1469 while (old_mems.is_nonempty()) {
1470 Node* old_mem = old_mems.node();
1471 uint old_cnt = old_mems.index();
1472 old_mems.pop();
1473 assert(old_cnt = old_mem->outcnt(), "old mem could be lost");
1474 }
1475 #endif
1476 }
1477
1478 bool ConnectionGraph::has_candidates(Compile *C) {
1479 // EA brings benefits only when the code has allocations and/or locks which
1480 // are represented by ideal Macro nodes.
1481 int cnt = C->macro_count();
1482 for( int i=0; i < cnt; i++ ) {
1483 Node *n = C->macro_node(i);
1484 if ( n->is_Allocate() )
1485 return true;
1486 if( n->is_Lock() ) {
1487 Node* obj = n->as_Lock()->obj_node()->uncast();
1488 if( !(obj->is_Parm() || obj->is_Con()) )
1489 return true;
1490 }
1491 }
1492 return false;
1493 }
1494
1495 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1496 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1497 // to create space for them in ConnectionGraph::_nodes[].
1498 Node* oop_null = igvn->zerocon(T_OBJECT);
1499 Node* noop_null = igvn->zerocon(T_NARROWOOP);
1500
1501 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1502 // Perform escape analysis
1503 if (congraph->compute_escape()) {
1504 // There are non escaping objects.
1505 C->set_congraph(congraph);
1506 }
1507
1508 // Cleanup.
1509 if (oop_null->outcnt() == 0)
1510 igvn->hash_delete(oop_null);
1511 if (noop_null->outcnt() == 0)
1512 igvn->hash_delete(noop_null);
1513 }
1514
1515 bool ConnectionGraph::compute_escape() {
1516 Compile* C = _compile;
1517
1518 // 1. Populate Connection Graph (CG) with Ideal nodes.
1519
1520 Unique_Node_List worklist_init;
1521 worklist_init.map(C->unique(), NULL); // preallocate space
1522
1523 // Initialize worklist
1524 if (C->root() != NULL) {
1525 worklist_init.push(C->root());
1526 }
1527
1528 GrowableArray<int> cg_worklist;
1529 PhaseGVN* igvn = _igvn;
1530 bool has_allocations = false;
1531
1532 // Push all useful nodes onto CG list and set their type.
1533 for( uint next = 0; next < worklist_init.size(); ++next ) {
1534 Node* n = worklist_init.at(next);
1535 record_for_escape_analysis(n, igvn);
1536 // Only allocations and java static calls results are checked
1537 // for an escape status. See process_call_result() below.
1538 if (n->is_Allocate() || n->is_CallStaticJava() &&
1539 ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1540 has_allocations = true;
1541 }
1542 if(n->is_AddP()) {
1543 // Collect address nodes which directly reference an allocation.
1544 // Use them during stage 3 below to build initial connection graph
1545 // field edges. Other field edges could be added after StoreP/LoadP
1546 // nodes are processed during stage 4 below.
1547 Node* base = get_addp_base(n);
1548 if(base->is_Proj() && base->in(0)->is_Allocate()) {
1549 cg_worklist.append(n->_idx);
1550 }
1551 } else if (n->is_MergeMem()) {
1552 // Collect all MergeMem nodes to add memory slices for
1553 // scalar replaceable objects in split_unique_types().
1554 _mergemem_worklist.append(n->as_MergeMem());
1555 }
1556 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1557 Node* m = n->fast_out(i); // Get user
1558 worklist_init.push(m);
1559 }
1560 }
1561
1562 if (!has_allocations) {
1563 _collecting = false;
1564 return false; // Nothing to do.
1565 }
1566
1567 // 2. First pass to create simple CG edges (doesn't require to walk CG).
1568 uint delayed_size = _delayed_worklist.size();
1569 for( uint next = 0; next < delayed_size; ++next ) {
1570 Node* n = _delayed_worklist.at(next);
1571 build_connection_graph(n, igvn);
1572 }
1573
1574 // 3. Pass to create fields edges (Allocate -F-> AddP).
1575 uint cg_length = cg_worklist.length();
1576 for( uint next = 0; next < cg_length; ++next ) {
1577 int ni = cg_worklist.at(next);
1578 build_connection_graph(ptnode_adr(ni)->_node, igvn);
1579 }
1580
1581 cg_worklist.clear();
1582 cg_worklist.append(_phantom_object);
1583
1584 // 4. Build Connection Graph which need
1585 // to walk the connection graph.
1586 for (uint ni = 0; ni < nodes_size(); ni++) {
1587 PointsToNode* ptn = ptnode_adr(ni);
1588 Node *n = ptn->_node;
1589 if (n != NULL) { // Call, AddP, LoadP, StoreP
1590 build_connection_graph(n, igvn);
1591 if (ptn->node_type() != PointsToNode::UnknownType)
1592 cg_worklist.append(n->_idx); // Collect CG nodes
1593 }
1594 }
1595
1596 Arena* arena = Thread::current()->resource_area();
1597 VectorSet ptset(arena);
1598 GrowableArray<uint> deferred_edges;
1599 VectorSet visited(arena);
1600
1601 // 5. Remove deferred edges from the graph and adjust
1602 // escape state of nonescaping objects.
1603 cg_length = cg_worklist.length();
1604 for( uint next = 0; next < cg_length; ++next ) {
1605 int ni = cg_worklist.at(next);
1606 PointsToNode* ptn = ptnode_adr(ni);
1607 PointsToNode::NodeType nt = ptn->node_type();
1608 if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1609 remove_deferred(ni, &deferred_edges, &visited);
1610 Node *n = ptn->_node;
1611 if (n->is_AddP()) {
1612 // Search for objects which are not scalar replaceable
1613 // and adjust their escape state.
1614 verify_escape_state(ni, ptset, igvn);
1615 }
1616 }
1617 }
1618
1619 // 6. Propagate escape states.
1620 GrowableArray<int> worklist;
1621 bool has_non_escaping_obj = false;
1622
1623 // push all GlobalEscape nodes on the worklist
1624 for( uint next = 0; next < cg_length; ++next ) {
1625 int nk = cg_worklist.at(next);
1626 if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
1627 worklist.push(nk);
1628 }
1629 // mark all nodes reachable from GlobalEscape nodes
1630 while(worklist.length() > 0) {
1631 PointsToNode* ptn = ptnode_adr(worklist.pop());
1632 uint e_cnt = ptn->edge_count();
1633 for (uint ei = 0; ei < e_cnt; ei++) {
1634 uint npi = ptn->edge_target(ei);
1635 PointsToNode *np = ptnode_adr(npi);
1636 if (np->escape_state() < PointsToNode::GlobalEscape) {
1637 np->set_escape_state(PointsToNode::GlobalEscape);
1638 worklist.push(npi);
1639 }
1640 }
1641 }
1642
1643 // push all ArgEscape nodes on the worklist
1644 for( uint next = 0; next < cg_length; ++next ) {
1645 int nk = cg_worklist.at(next);
1646 if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
1647 worklist.push(nk);
1648 }
1649 // mark all nodes reachable from ArgEscape nodes
1650 while(worklist.length() > 0) {
1651 PointsToNode* ptn = ptnode_adr(worklist.pop());
1652 if (ptn->node_type() == PointsToNode::JavaObject)
1653 has_non_escaping_obj = true; // Non GlobalEscape
1654 uint e_cnt = ptn->edge_count();
1655 for (uint ei = 0; ei < e_cnt; ei++) {
1656 uint npi = ptn->edge_target(ei);
1657 PointsToNode *np = ptnode_adr(npi);
1658 if (np->escape_state() < PointsToNode::ArgEscape) {
1659 np->set_escape_state(PointsToNode::ArgEscape);
1660 worklist.push(npi);
1661 }
1662 }
1663 }
1664
1665 GrowableArray<Node*> alloc_worklist;
1666
1667 // push all NoEscape nodes on the worklist
1668 for( uint next = 0; next < cg_length; ++next ) {
1669 int nk = cg_worklist.at(next);
1670 if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1671 worklist.push(nk);
1672 }
1673 // mark all nodes reachable from NoEscape nodes
1674 while(worklist.length() > 0) {
1675 PointsToNode* ptn = ptnode_adr(worklist.pop());
1676 if (ptn->node_type() == PointsToNode::JavaObject)
1677 has_non_escaping_obj = true; // Non GlobalEscape
1678 Node* n = ptn->_node;
1679 if (n->is_Allocate() && ptn->_scalar_replaceable ) {
1680 // Push scalar replaceable allocations on alloc_worklist
1681 // for processing in split_unique_types().
1682 alloc_worklist.append(n);
1683 }
1684 uint e_cnt = ptn->edge_count();
1685 for (uint ei = 0; ei < e_cnt; ei++) {
1686 uint npi = ptn->edge_target(ei);
1687 PointsToNode *np = ptnode_adr(npi);
1688 if (np->escape_state() < PointsToNode::NoEscape) {
1689 np->set_escape_state(PointsToNode::NoEscape);
1690 worklist.push(npi);
1691 }
1692 }
1693 }
1694
1695 _collecting = false;
1696 assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1697
1698 #ifndef PRODUCT
1699 if (PrintEscapeAnalysis) {
1700 dump(); // Dump ConnectionGraph
1701 }
1702 #endif
1703
1704 bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1705 if ( has_scalar_replaceable_candidates &&
1706 C->AliasLevel() >= 3 && EliminateAllocations ) {
1707
1708 // Now use the escape information to create unique types for
1709 // scalar replaceable objects.
1710 split_unique_types(alloc_worklist);
1711
1712 if (C->failing()) return false;
1713
1714 C->print_method("After Escape Analysis", 2);
1715
1716 #ifdef ASSERT
1717 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1718 tty->print("=== No allocations eliminated for ");
1719 C->method()->print_short_name();
1720 if(!EliminateAllocations) {
1721 tty->print(" since EliminateAllocations is off ===");
1722 } else if(!has_scalar_replaceable_candidates) {
1723 tty->print(" since there are no scalar replaceable candidates ===");
1724 } else if(C->AliasLevel() < 3) {
1725 tty->print(" since AliasLevel < 3 ===");
1726 }
1727 tty->cr();
1728 #endif
1729 }
1730 return has_non_escaping_obj;
1731 }
1732
1733 // Search for objects which are not scalar replaceable.
1734 void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
1735 PointsToNode* ptn = ptnode_adr(nidx);
1736 Node* n = ptn->_node;
1737 assert(n->is_AddP(), "Should be called for AddP nodes only");
1738 // Search for objects which are not scalar replaceable.
1739 // Mark their escape state as ArgEscape to propagate the state
1740 // to referenced objects.
1741 // Note: currently there are no difference in compiler optimizations
1742 // for ArgEscape objects and NoEscape objects which are not
1743 // scalar replaceable.
1744
1745 Compile* C = _compile;
1746
1747 int offset = ptn->offset();
1748 Node* base = get_addp_base(n);
1749 ptset.Clear();
1750 PointsTo(ptset, base);
1751 int ptset_size = ptset.Size();
1752
1753 // Check if a oop field's initializing value is recorded and add
1754 // a corresponding NULL field's value if it is not recorded.
1755 // Connection Graph does not record a default initialization by NULL
1756 // captured by Initialize node.
1757 //
1758 // Note: it will disable scalar replacement in some cases:
1759 //
1760 // Point p[] = new Point[1];
1761 // p[0] = new Point(); // Will be not scalar replaced
1762 //
1763 // but it will save us from incorrect optimizations in next cases:
1764 //
1765 // Point p[] = new Point[1];
1766 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1767 //
1768 // Do a simple control flow analysis to distinguish above cases.
1769 //
1770 if (offset != Type::OffsetBot && ptset_size == 1) {
1771 uint elem = ptset.getelem(); // Allocation node's index
1772 // It does not matter if it is not Allocation node since
1773 // only non-escaping allocations are scalar replaced.
1774 if (ptnode_adr(elem)->_node->is_Allocate() &&
1775 ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
1776 AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
1777 InitializeNode* ini = alloc->initialization();
1778
1779 // Check only oop fields.
1780 const Type* adr_type = n->as_AddP()->bottom_type();
1781 BasicType basic_field_type = T_INT;
1782 if (adr_type->isa_instptr()) {
1783 ciField* field = C->alias_type(adr_type->isa_instptr())->field();
1784 if (field != NULL) {
1785 basic_field_type = field->layout_type();
1786 } else {
1787 // Ignore non field load (for example, klass load)
1788 }
1789 } else if (adr_type->isa_aryptr()) {
1790 const Type* elemtype = adr_type->isa_aryptr()->elem();
1791 basic_field_type = elemtype->array_element_basic_type();
1792 } else {
1793 // Raw pointers are used for initializing stores so skip it.
1794 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1795 (base->in(0) == alloc),"unexpected pointer type");
1796 }
1797 if (basic_field_type == T_OBJECT ||
1798 basic_field_type == T_NARROWOOP ||
1799 basic_field_type == T_ARRAY) {
1800 Node* value = NULL;
1801 if (ini != NULL) {
1802 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1803 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1804 if (store != NULL && store->is_Store()) {
1805 value = store->in(MemNode::ValueIn);
1806 } else if (ptn->edge_count() > 0) { // Are there oop stores?
1807 // Check for a store which follows allocation without branches.
1808 // For example, a volatile field store is not collected
1809 // by Initialize node. TODO: it would be nice to use idom() here.
1810 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1811 store = n->fast_out(i);
1812 if (store->is_Store() && store->in(0) != NULL) {
1813 Node* ctrl = store->in(0);
1814 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
1815 ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
1816 ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
1817 ctrl = ctrl->in(0);
1818 }
1819 if (ctrl == ini || ctrl == alloc) {
1820 value = store->in(MemNode::ValueIn);
1821 break;
1822 }
1823 }
1824 }
1825 }
1826 }
1827 if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1828 // A field's initializing value was not recorded. Add NULL.
1829 uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1830 add_pointsto_edge(nidx, null_idx);
1831 }
1832 }
1833 }
1834 }
1835
1836 // An object is not scalar replaceable if the field which may point
1837 // to it has unknown offset (unknown element of an array of objects).
1838 //
1839 if (offset == Type::OffsetBot) {
1840 uint e_cnt = ptn->edge_count();
1841 for (uint ei = 0; ei < e_cnt; ei++) {
1842 uint npi = ptn->edge_target(ei);
1843 set_escape_state(npi, PointsToNode::ArgEscape);
1844 ptnode_adr(npi)->_scalar_replaceable = false;
1845 }
1846 }
1847
1848 // Currently an object is not scalar replaceable if a LoadStore node
1849 // access its field since the field value is unknown after it.
1850 //
1851 bool has_LoadStore = false;
1852 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1853 Node *use = n->fast_out(i);
1854 if (use->is_LoadStore()) {
1855 has_LoadStore = true;
1856 break;
1857 }
1858 }
1859 // An object is not scalar replaceable if the address points
1860 // to unknown field (unknown element for arrays, offset is OffsetBot).
1861 //
1862 // Or the address may point to more then one object. This may produce
1863 // the false positive result (set scalar_replaceable to false)
1864 // since the flow-insensitive escape analysis can't separate
1865 // the case when stores overwrite the field's value from the case
1866 // when stores happened on different control branches.
1867 //
1868 if (ptset_size > 1 || ptset_size != 0 &&
1869 (has_LoadStore || offset == Type::OffsetBot)) {
1870 for( VectorSetI j(&ptset); j.test(); ++j ) {
1871 set_escape_state(j.elem, PointsToNode::ArgEscape);
1872 ptnode_adr(j.elem)->_scalar_replaceable = false;
1873 }
1874 }
1875 }
1876
1877 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1878
1879 switch (call->Opcode()) {
1880 #ifdef ASSERT
1881 case Op_Allocate:
1882 case Op_AllocateArray:
1883 case Op_Lock:
1884 case Op_Unlock:
1885 assert(false, "should be done already");
1886 break;
1887 #endif
1888 case Op_CallLeaf:
1889 case Op_CallLeafNoFP:
1890 {
1891 // Stub calls, objects do not escape but they are not scale replaceable.
1892 // Adjust escape state for outgoing arguments.
1893 const TypeTuple * d = call->tf()->domain();
1894 VectorSet ptset(Thread::current()->resource_area());
1895 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1896 const Type* at = d->field_at(i);
1897 Node *arg = call->in(i)->uncast();
1898 const Type *aat = phase->type(arg);
1899 if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
1900 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
1901
1902 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1903 aat->isa_ptr() != NULL, "expecting an Ptr");
1904 #ifdef ASSERT
1905 if (!(call->Opcode() == Op_CallLeafNoFP &&
1906 call->as_CallLeaf()->_name != NULL &&
1907 (strstr(call->as_CallLeaf()->_name, "arraycopy") != 0) ||
1908 call->as_CallLeaf()->_name != NULL &&
1909 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
1910 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
1911 ) {
1912 call->dump();
1913 assert(false, "EA: unexpected CallLeaf");
1914 }
1915 #endif
1916 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1917 if (arg->is_AddP()) {
1918 //
1919 // The inline_native_clone() case when the arraycopy stub is called
1920 // after the allocation before Initialize and CheckCastPP nodes.
1921 //
1922 // Set AddP's base (Allocate) as not scalar replaceable since
1923 // pointer to the base (with offset) is passed as argument.
1924 //
1925 arg = get_addp_base(arg);
1926 }
1927 ptset.Clear();
1928 PointsTo(ptset, arg);
1929 for( VectorSetI j(&ptset); j.test(); ++j ) {
1930 uint pt = j.elem;
1931 set_escape_state(pt, PointsToNode::ArgEscape);
1932 }
1933 }
1934 }
1935 break;
1936 }
1937
1938 case Op_CallStaticJava:
1939 // For a static call, we know exactly what method is being called.
1940 // Use bytecode estimator to record the call's escape affects
1941 {
1942 ciMethod *meth = call->as_CallJava()->method();
1943 BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1944 // fall-through if not a Java method or no analyzer information
1945 if (call_analyzer != NULL) {
1946 const TypeTuple * d = call->tf()->domain();
1947 VectorSet ptset(Thread::current()->resource_area());
1948 bool copy_dependencies = false;
1949 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1950 const Type* at = d->field_at(i);
1951 int k = i - TypeFunc::Parms;
1952 Node *arg = call->in(i)->uncast();
1953
1954 if (at->isa_oopptr() != NULL &&
1955 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
1956
1957 bool global_escapes = false;
1958 bool fields_escapes = false;
1959 if (!call_analyzer->is_arg_stack(k)) {
1960 // The argument global escapes, mark everything it could point to
1961 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1962 global_escapes = true;
1963 } else {
1964 if (!call_analyzer->is_arg_local(k)) {
1965 // The argument itself doesn't escape, but any fields might
1966 fields_escapes = true;
1967 }
1968 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1969 copy_dependencies = true;
1970 }
1971
1972 ptset.Clear();
1973 PointsTo(ptset, arg);
1974 for( VectorSetI j(&ptset); j.test(); ++j ) {
1975 uint pt = j.elem;
1976 if (global_escapes) {
1977 //The argument global escapes, mark everything it could point to
1978 set_escape_state(pt, PointsToNode::GlobalEscape);
1979 } else {
1980 if (fields_escapes) {
1981 // The argument itself doesn't escape, but any fields might
1982 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
1983 }
1984 set_escape_state(pt, PointsToNode::ArgEscape);
1985 }
1986 }
1987 }
1988 }
1989 if (copy_dependencies)
1990 call_analyzer->copy_dependencies(_compile->dependencies());
1991 break;
1992 }
1993 }
1994
1995 default:
1996 // Fall-through here if not a Java method or no analyzer information
1997 // or some other type of call, assume the worst case: all arguments
1998 // globally escape.
1999 {
2000 // adjust escape state for outgoing arguments
2001 const TypeTuple * d = call->tf()->domain();
2002 VectorSet ptset(Thread::current()->resource_area());
2003 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2004 const Type* at = d->field_at(i);
2005 if (at->isa_oopptr() != NULL) {
2006 Node *arg = call->in(i)->uncast();
2007 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2008 ptset.Clear();
2009 PointsTo(ptset, arg);
2010 for( VectorSetI j(&ptset); j.test(); ++j ) {
2011 uint pt = j.elem;
2012 set_escape_state(pt, PointsToNode::GlobalEscape);
2013 }
2014 }
2015 }
2016 }
2017 }
2018 }
2019 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
2020 CallNode *call = resproj->in(0)->as_Call();
2021 uint call_idx = call->_idx;
2022 uint resproj_idx = resproj->_idx;
2023
2024 switch (call->Opcode()) {
2025 case Op_Allocate:
2026 {
2027 Node *k = call->in(AllocateNode::KlassNode);
2028 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2029 assert(kt != NULL, "TypeKlassPtr required.");
2030 ciKlass* cik = kt->klass();
2031
2032 PointsToNode::EscapeState es;
2033 uint edge_to;
2034 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2035 !cik->is_instance_klass() || // StressReflectiveCode
2036 cik->as_instance_klass()->has_finalizer()) {
2037 es = PointsToNode::GlobalEscape;
2038 edge_to = _phantom_object; // Could not be worse
2039 } else {
2040 es = PointsToNode::NoEscape;
2041 edge_to = call_idx;
2042 }
2043 set_escape_state(call_idx, es);
2044 add_pointsto_edge(resproj_idx, edge_to);
2045 _processed.set(resproj_idx);
2046 break;
2047 }
2048
2049 case Op_AllocateArray:
2050 {
2051
2052 Node *k = call->in(AllocateNode::KlassNode);
2053 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2054 assert(kt != NULL, "TypeKlassPtr required.");
2055 ciKlass* cik = kt->klass();
2056
2057 PointsToNode::EscapeState es;
2058 uint edge_to;
2059 if (!cik->is_array_klass()) { // StressReflectiveCode
2060 es = PointsToNode::GlobalEscape;
2061 edge_to = _phantom_object;
2062 } else {
2063 es = PointsToNode::NoEscape;
2064 edge_to = call_idx;
2065 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2066 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2067 // Not scalar replaceable if the length is not constant or too big.
2068 ptnode_adr(call_idx)->_scalar_replaceable = false;
2069 }
2070 }
2071 set_escape_state(call_idx, es);
2072 add_pointsto_edge(resproj_idx, edge_to);
2073 _processed.set(resproj_idx);
2074 break;
2075 }
2076
2077 case Op_CallStaticJava:
2078 // For a static call, we know exactly what method is being called.
2079 // Use bytecode estimator to record whether the call's return value escapes
2080 {
2081 bool done = true;
2082 const TypeTuple *r = call->tf()->range();
2083 const Type* ret_type = NULL;
2084
2085 if (r->cnt() > TypeFunc::Parms)
2086 ret_type = r->field_at(TypeFunc::Parms);
2087
2088 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2089 // _multianewarray functions return a TypeRawPtr.
2090 if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2091 _processed.set(resproj_idx);
2092 break; // doesn't return a pointer type
2093 }
2094 ciMethod *meth = call->as_CallJava()->method();
2095 const TypeTuple * d = call->tf()->domain();
2096 if (meth == NULL) {
2097 // not a Java method, assume global escape
2098 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2099 add_pointsto_edge(resproj_idx, _phantom_object);
2100 } else {
2101 BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2102 bool copy_dependencies = false;
2103
2104 if (call_analyzer->is_return_allocated()) {
2105 // Returns a newly allocated unescaped object, simply
2106 // update dependency information.
2107 // Mark it as NoEscape so that objects referenced by
2108 // it's fields will be marked as NoEscape at least.
2109 set_escape_state(call_idx, PointsToNode::NoEscape);
2110 add_pointsto_edge(resproj_idx, call_idx);
2111 copy_dependencies = true;
2112 } else if (call_analyzer->is_return_local()) {
2113 // determine whether any arguments are returned
2114 set_escape_state(call_idx, PointsToNode::NoEscape);
2115 bool ret_arg = false;
2116 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2117 const Type* at = d->field_at(i);
2118
2119 if (at->isa_oopptr() != NULL) {
2120 Node *arg = call->in(i)->uncast();
2121
2122 if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2123 ret_arg = true;
2124 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2125 if (arg_esp->node_type() == PointsToNode::UnknownType)
2126 done = false;
2127 else if (arg_esp->node_type() == PointsToNode::JavaObject)
2128 add_pointsto_edge(resproj_idx, arg->_idx);
2129 else
2130 add_deferred_edge(resproj_idx, arg->_idx);
2131 arg_esp->_hidden_alias = true;
2132 }
2133 }
2134 }
2135 if (done && !ret_arg) {
2136 // Returns unknown object.
2137 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2138 add_pointsto_edge(resproj_idx, _phantom_object);
2139 }
2140 copy_dependencies = true;
2141 } else {
2142 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2143 add_pointsto_edge(resproj_idx, _phantom_object);
2144 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2145 const Type* at = d->field_at(i);
2146 if (at->isa_oopptr() != NULL) {
2147 Node *arg = call->in(i)->uncast();
2148 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2149 arg_esp->_hidden_alias = true;
2150 }
2151 }
2152 }
2153 if (copy_dependencies)
2154 call_analyzer->copy_dependencies(_compile->dependencies());
2155 }
2156 if (done)
2157 _processed.set(resproj_idx);
2158 break;
2159 }
2160
2161 default:
2162 // Some other type of call, assume the worst case that the
2163 // returned value, if any, globally escapes.
2164 {
2165 const TypeTuple *r = call->tf()->range();
2166 if (r->cnt() > TypeFunc::Parms) {
2167 const Type* ret_type = r->field_at(TypeFunc::Parms);
2168
2169 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2170 // _multianewarray functions return a TypeRawPtr.
2171 if (ret_type->isa_ptr() != NULL) {
2172 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2173 add_pointsto_edge(resproj_idx, _phantom_object);
2174 }
2175 }
2176 _processed.set(resproj_idx);
2177 }
2178 }
2179 }
2180
2181 // Populate Connection Graph with Ideal nodes and create simple
2182 // connection graph edges (do not need to check the node_type of inputs
2183 // or to call PointsTo() to walk the connection graph).
2184 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2185 if (_processed.test(n->_idx))
2186 return; // No need to redefine node's state.
2187
2188 if (n->is_Call()) {
2189 // Arguments to allocation and locking don't escape.
2190 if (n->is_Allocate()) {
2191 add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2192 record_for_optimizer(n);
2193 } else if (n->is_Lock() || n->is_Unlock()) {
2194 // Put Lock and Unlock nodes on IGVN worklist to process them during
2195 // the first IGVN optimization when escape information is still available.
2196 record_for_optimizer(n);
2197 _processed.set(n->_idx);
2198 } else {
2199 // Don't mark as processed since call's arguments have to be processed.
2200 PointsToNode::NodeType nt = PointsToNode::UnknownType;
2201 PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2202
2203 // Check if a call returns an object.
2204 const TypeTuple *r = n->as_Call()->tf()->range();
2205 if (r->cnt() > TypeFunc::Parms &&
2206 r->field_at(TypeFunc::Parms)->isa_ptr() &&
2207 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2208 nt = PointsToNode::JavaObject;
2209 if (!n->is_CallStaticJava()) {
2210 // Since the called mathod is statically unknown assume
2211 // the worst case that the returned value globally escapes.
2212 es = PointsToNode::GlobalEscape;
2213 }
2214 }
2215 add_node(n, nt, es, false);
2216 }
2217 return;
2218 }
2219
2220 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2221 // ThreadLocal has RawPrt type.
2222 switch (n->Opcode()) {
2223 case Op_AddP:
2224 {
2225 add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
2226 break;
2227 }
2228 case Op_CastX2P:
2229 { // "Unsafe" memory access.
2230 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2231 break;
2232 }
2233 case Op_CastPP:
2234 case Op_CheckCastPP:
2235 case Op_EncodeP:
2236 case Op_DecodeN:
2237 {
2238 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2239 int ti = n->in(1)->_idx;
2240 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2241 if (nt == PointsToNode::UnknownType) {
2242 _delayed_worklist.push(n); // Process it later.
2243 break;
2244 } else if (nt == PointsToNode::JavaObject) {
2245 add_pointsto_edge(n->_idx, ti);
2246 } else {
2247 add_deferred_edge(n->_idx, ti);
2248 }
2249 _processed.set(n->_idx);
2250 break;
2251 }
2252 case Op_ConP:
2253 {
2254 // assume all pointer constants globally escape except for null
2255 PointsToNode::EscapeState es;
2256 if (phase->type(n) == TypePtr::NULL_PTR)
2257 es = PointsToNode::NoEscape;
2258 else
2259 es = PointsToNode::GlobalEscape;
2260
2261 add_node(n, PointsToNode::JavaObject, es, true);
2262 break;
2263 }
2264 case Op_ConN:
2265 {
2266 // assume all narrow oop constants globally escape except for null
2267 PointsToNode::EscapeState es;
2268 if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2269 es = PointsToNode::NoEscape;
2270 else
2271 es = PointsToNode::GlobalEscape;
2272
2273 add_node(n, PointsToNode::JavaObject, es, true);
2274 break;
2275 }
2276 case Op_CreateEx:
2277 {
2278 // assume that all exception objects globally escape
2279 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2280 break;
2281 }
2282 case Op_LoadKlass:
2283 case Op_LoadNKlass:
2284 {
2285 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2286 break;
2287 }
2288 case Op_LoadP:
2289 case Op_LoadN:
2290 {
2291 const Type *t = phase->type(n);
2292 if (t->make_ptr() == NULL) {
2293 _processed.set(n->_idx);
2294 return;
2295 }
2296 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2297 break;
2298 }
2299 case Op_Parm:
2300 {
2301 _processed.set(n->_idx); // No need to redefine it state.
2302 uint con = n->as_Proj()->_con;
2303 if (con < TypeFunc::Parms)
2304 return;
2305 const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2306 if (t->isa_ptr() == NULL)
2307 return;
2308 // We have to assume all input parameters globally escape
2309 // (Note: passing 'false' since _processed is already set).
2310 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2311 break;
2312 }
2313 case Op_Phi:
2314 {
2315 const Type *t = n->as_Phi()->type();
2316 if (t->make_ptr() == NULL) {
2317 // nothing to do if not an oop or narrow oop
2318 _processed.set(n->_idx);
2319 return;
2320 }
2321 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2322 uint i;
2323 for (i = 1; i < n->req() ; i++) {
2324 Node* in = n->in(i);
2325 if (in == NULL)
2326 continue; // ignore NULL
2327 in = in->uncast();
2328 if (in->is_top() || in == n)
2329 continue; // ignore top or inputs which go back this node
2330 int ti = in->_idx;
2331 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2332 if (nt == PointsToNode::UnknownType) {
2333 break;
2334 } else if (nt == PointsToNode::JavaObject) {
2335 add_pointsto_edge(n->_idx, ti);
2336 } else {
2337 add_deferred_edge(n->_idx, ti);
2338 }
2339 }
2340 if (i >= n->req())
2341 _processed.set(n->_idx);
2342 else
2343 _delayed_worklist.push(n);
2344 break;
2345 }
2346 case Op_Proj:
2347 {
2348 // we are only interested in the oop result projection from a call
2349 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2350 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2351 assert(r->cnt() > TypeFunc::Parms, "sanity");
2352 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2353 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2354 int ti = n->in(0)->_idx;
2355 // The call may not be registered yet (since not all its inputs are registered)
2356 // if this is the projection from backbranch edge of Phi.
2357 if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2358 process_call_result(n->as_Proj(), phase);
2359 }
2360 if (!_processed.test(n->_idx)) {
2361 // The call's result may need to be processed later if the call
2362 // returns it's argument and the argument is not processed yet.
2363 _delayed_worklist.push(n);
2364 }
2365 break;
2366 }
2367 }
2368 _processed.set(n->_idx);
2369 break;
2370 }
2371 case Op_Return:
2372 {
2373 if( n->req() > TypeFunc::Parms &&
2374 phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2375 // Treat Return value as LocalVar with GlobalEscape escape state.
2376 add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2377 int ti = n->in(TypeFunc::Parms)->_idx;
2378 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2379 if (nt == PointsToNode::UnknownType) {
2380 _delayed_worklist.push(n); // Process it later.
2381 break;
2382 } else if (nt == PointsToNode::JavaObject) {
2383 add_pointsto_edge(n->_idx, ti);
2384 } else {
2385 add_deferred_edge(n->_idx, ti);
2386 }
2387 }
2388 _processed.set(n->_idx);
2389 break;
2390 }
2391 case Op_StoreP:
2392 case Op_StoreN:
2393 {
2394 const Type *adr_type = phase->type(n->in(MemNode::Address));
2395 adr_type = adr_type->make_ptr();
2396 if (adr_type->isa_oopptr()) {
2397 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2398 } else {
2399 Node* adr = n->in(MemNode::Address);
2400 if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2401 adr->in(AddPNode::Address)->is_Proj() &&
2402 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2403 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2404 // We are computing a raw address for a store captured
2405 // by an Initialize compute an appropriate address type.
2406 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2407 assert(offs != Type::OffsetBot, "offset must be a constant");
2408 } else {
2409 _processed.set(n->_idx);
2410 return;
2411 }
2412 }
2413 break;
2414 }
2415 case Op_StorePConditional:
2416 case Op_CompareAndSwapP:
2417 case Op_CompareAndSwapN:
2418 {
2419 const Type *adr_type = phase->type(n->in(MemNode::Address));
2420 adr_type = adr_type->make_ptr();
2421 if (adr_type->isa_oopptr()) {
2422 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2423 } else {
2424 _processed.set(n->_idx);
2425 return;
2426 }
2427 break;
2428 }
2429 case Op_AryEq:
2430 case Op_StrComp:
2431 case Op_StrEquals:
2432 case Op_StrIndexOf:
2433 {
2434 // char[] arrays passed to string intrinsics are not scalar replaceable.
2435 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2436 break;
2437 }
2438 case Op_ThreadLocal:
2439 {
2440 add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2441 break;
2442 }
2443 default:
2444 ;
2445 // nothing to do
2446 }
2447 return;
2448 }
2449
2450 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2451 uint n_idx = n->_idx;
2452 assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2453
2454 // Don't set processed bit for AddP, LoadP, StoreP since
2455 // they may need more then one pass to process.
2456 if (_processed.test(n_idx))
2457 return; // No need to redefine node's state.
2458
2459 if (n->is_Call()) {
2460 CallNode *call = n->as_Call();
2461 process_call_arguments(call, phase);
2462 _processed.set(n_idx);
2463 return;
2464 }
2465
2466 switch (n->Opcode()) {
2467 case Op_AddP:
2468 {
2469 Node *base = get_addp_base(n);
2470 // Create a field edge to this node from everything base could point to.
2471 VectorSet ptset(Thread::current()->resource_area());
2472 PointsTo(ptset, base);
2473 for( VectorSetI i(&ptset); i.test(); ++i ) {
2474 uint pt = i.elem;
2475 add_field_edge(pt, n_idx, address_offset(n, phase));
2476 }
2477 break;
2478 }
2479 case Op_CastX2P:
2480 {
2481 assert(false, "Op_CastX2P");
2482 break;
2483 }
2484 case Op_CastPP:
2485 case Op_CheckCastPP:
2486 case Op_EncodeP:
2487 case Op_DecodeN:
2488 {
2489 int ti = n->in(1)->_idx;
2490 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2491 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2492 add_pointsto_edge(n_idx, ti);
2493 } else {
2494 add_deferred_edge(n_idx, ti);
2495 }
2496 _processed.set(n_idx);
2497 break;
2498 }
2499 case Op_ConP:
2500 {
2501 assert(false, "Op_ConP");
2502 break;
2503 }
2504 case Op_ConN:
2505 {
2506 assert(false, "Op_ConN");
2507 break;
2508 }
2509 case Op_CreateEx:
2510 {
2511 assert(false, "Op_CreateEx");
2512 break;
2513 }
2514 case Op_LoadKlass:
2515 case Op_LoadNKlass:
2516 {
2517 assert(false, "Op_LoadKlass");
2518 break;
2519 }
2520 case Op_LoadP:
2521 case Op_LoadN:
2522 {
2523 const Type *t = phase->type(n);
2524 #ifdef ASSERT
2525 if (t->make_ptr() == NULL)
2526 assert(false, "Op_LoadP");
2527 #endif
2528
2529 Node* adr = n->in(MemNode::Address)->uncast();
2530 Node* adr_base;
2531 if (adr->is_AddP()) {
2532 adr_base = get_addp_base(adr);
2533 } else {
2534 adr_base = adr;
2535 }
2536
2537 // For everything "adr_base" could point to, create a deferred edge from
2538 // this node to each field with the same offset.
2539 VectorSet ptset(Thread::current()->resource_area());
2540 PointsTo(ptset, adr_base);
2541 int offset = address_offset(adr, phase);
2542 for( VectorSetI i(&ptset); i.test(); ++i ) {
2543 uint pt = i.elem;
2544 add_deferred_edge_to_fields(n_idx, pt, offset);
2545 }
2546 break;
2547 }
2548 case Op_Parm:
2549 {
2550 assert(false, "Op_Parm");
2551 break;
2552 }
2553 case Op_Phi:
2554 {
2555 #ifdef ASSERT
2556 const Type *t = n->as_Phi()->type();
2557 if (t->make_ptr() == NULL)
2558 assert(false, "Op_Phi");
2559 #endif
2560 for (uint i = 1; i < n->req() ; i++) {
2561 Node* in = n->in(i);
2562 if (in == NULL)
2563 continue; // ignore NULL
2564 in = in->uncast();
2565 if (in->is_top() || in == n)
2566 continue; // ignore top or inputs which go back this node
2567 int ti = in->_idx;
2568 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2569 assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2570 if (nt == PointsToNode::JavaObject) {
2571 add_pointsto_edge(n_idx, ti);
2572 } else {
2573 add_deferred_edge(n_idx, ti);
2574 }
2575 }
2576 _processed.set(n_idx);
2577 break;
2578 }
2579 case Op_Proj:
2580 {
2581 // we are only interested in the oop result projection from a call
2582 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2583 assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
2584 "all nodes should be registered");
2585 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2586 assert(r->cnt() > TypeFunc::Parms, "sanity");
2587 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2588 process_call_result(n->as_Proj(), phase);
2589 assert(_processed.test(n_idx), "all call results should be processed");
2590 break;
2591 }
2592 }
2593 assert(false, "Op_Proj");
2594 break;
2595 }
2596 case Op_Return:
2597 {
2598 #ifdef ASSERT
2599 if( n->req() <= TypeFunc::Parms ||
2600 !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2601 assert(false, "Op_Return");
2602 }
2603 #endif
2604 int ti = n->in(TypeFunc::Parms)->_idx;
2605 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
2606 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2607 add_pointsto_edge(n_idx, ti);
2608 } else {
2609 add_deferred_edge(n_idx, ti);
2610 }
2611 _processed.set(n_idx);
2612 break;
2613 }
2614 case Op_StoreP:
2615 case Op_StoreN:
2616 case Op_StorePConditional:
2617 case Op_CompareAndSwapP:
2618 case Op_CompareAndSwapN:
2619 {
2620 Node *adr = n->in(MemNode::Address);
2621 const Type *adr_type = phase->type(adr)->make_ptr();
2622 #ifdef ASSERT
2623 if (!adr_type->isa_oopptr())
2624 assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2625 #endif
2626
2627 assert(adr->is_AddP(), "expecting an AddP");
2628 Node *adr_base = get_addp_base(adr);
2629 Node *val = n->in(MemNode::ValueIn)->uncast();
2630 // For everything "adr_base" could point to, create a deferred edge
2631 // to "val" from each field with the same offset.
2632 VectorSet ptset(Thread::current()->resource_area());
2633 PointsTo(ptset, adr_base);
2634 for( VectorSetI i(&ptset); i.test(); ++i ) {
2635 uint pt = i.elem;
2636 add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2637 }
2638 break;
2639 }
2640 case Op_AryEq:
2641 case Op_StrComp:
2642 case Op_StrEquals:
2643 case Op_StrIndexOf:
2644 {
2645 // char[] arrays passed to string intrinsic do not escape but
2646 // they are not scalar replaceable. Adjust escape state for them.
2647 // Start from in(2) edge since in(1) is memory edge.
2648 for (uint i = 2; i < n->req(); i++) {
2649 Node* adr = n->in(i)->uncast();
2650 const Type *at = phase->type(adr);
2651 if (!adr->is_top() && at->isa_ptr()) {
2652 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
2653 at->isa_ptr() != NULL, "expecting an Ptr");
2654 if (adr->is_AddP()) {
2655 adr = get_addp_base(adr);
2656 }
2657 // Mark as ArgEscape everything "adr" could point to.
2658 set_escape_state(adr->_idx, PointsToNode::ArgEscape);
2659 }
2660 }
2661 _processed.set(n_idx);
2662 break;
2663 }
2664 case Op_ThreadLocal:
2665 {
2666 assert(false, "Op_ThreadLocal");
2667 break;
2668 }
2669 default:
2670 // This method should be called only for EA specific nodes.
2671 ShouldNotReachHere();
2672 }
2673 }
2674
2675 #ifndef PRODUCT
2676 void ConnectionGraph::dump() {
2677 bool first = true;
2678
2679 uint size = nodes_size();
2680 for (uint ni = 0; ni < size; ni++) {
2681 PointsToNode *ptn = ptnode_adr(ni);
2682 PointsToNode::NodeType ptn_type = ptn->node_type();
2683
2684 if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2685 continue;
2686 PointsToNode::EscapeState es = escape_state(ptn->_node);
2687 if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2688 if (first) {
2689 tty->cr();
2690 tty->print("======== Connection graph for ");
2691 _compile->method()->print_short_name();
2692 tty->cr();
2693 first = false;
2694 }
2695 tty->print("%6d ", ni);
2696 ptn->dump();
2697 // Print all locals which reference this allocation
2698 for (uint li = ni; li < size; li++) {
2699 PointsToNode *ptn_loc = ptnode_adr(li);
2700 PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2701 if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2702 ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2703 ptnode_adr(li)->dump(false);
2704 }
2705 }
2706 if (Verbose) {
2707 // Print all fields which reference this allocation
2708 for (uint i = 0; i < ptn->edge_count(); i++) {
2709 uint ei = ptn->edge_target(i);
2710 ptnode_adr(ei)->dump(false);
2711 }
2712 }
2713 tty->cr();
2714 }
2715 }
2716 }
2717 #endif