1 /*
2 * Copyright (c) 2005, 2012, 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 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
38 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
39 _collecting(true),
40 _verify(false),
41 _compile(C),
42 _igvn(igvn),
43 _node_map(C->comp_arena()) {
44
45 add_java_object(C->top(), PointsToNode::GlobalEscape);
46 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
47
48 // Add ConP(#NULL) and ConN(#NULL) nodes.
49 Node* oop_null = igvn->zerocon(T_OBJECT);
50 assert(oop_null->_idx < nodes_size(), "should be created already");
51 add_java_object(oop_null, PointsToNode::NoEscape);
52 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
53
54 if (UseCompressedOops) {
55 Node* noop_null = igvn->zerocon(T_NARROWOOP);
56 assert(noop_null->_idx < nodes_size(), "should be created already");
57 map_ideal_node(noop_null, null_obj);
58 }
59 _pcmp_neq = NULL; // Should be initialized
60 _pcmp_eq = NULL;
61 }
62
63 // Connection Graph constuction functions.
64
65 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
66 PointsToNode* ptadr = _nodes.at(n->_idx);
67 if (ptadr != NULL) {
68 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
69 return;
70 }
71 ptadr = new LocalVarNode(n, es);
72 _nodes.at_put(n->_idx, ptadr);
73 }
74
75 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
76 PointsToNode* ptadr = _nodes.at(n->_idx);
77 if (ptadr != NULL) {
78 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
79 return;
80 }
81 ptadr = new JavaObjectNode(n, es);
82 _nodes.at_put(n->_idx, ptadr);
83 }
84
85 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
86 PointsToNode* ptadr = _nodes.at(n->_idx);
87 if (ptadr != NULL) {
88 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
89 return;
90 }
91 bool is_oop = is_oop_field(n, offset);
92 FieldNode* field = new FieldNode(n, es, offset, is_oop);
93 _nodes.at_put(n->_idx, field);
94 }
95
96 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
97 PointsToNode* src, PointsToNode* dst) {
98 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
99 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
100 PointsToNode* ptadr = _nodes.at(n->_idx);
101 if (ptadr != NULL) {
102 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
103 return;
104 }
105 ptadr = new ArraycopyNode(n, es);
106 _nodes.at_put(n->_idx, ptadr);
107 // Add edge from arraycopy node to source object.
108 (void)add_edge(ptadr, src);
109 src->set_arraycopy_src();
110 // Add edge from destination object to arraycopy node.
111 (void)add_edge(dst, ptadr);
112 dst->set_arraycopy_dst();
113 }
114
115 bool ConnectionGraph::is_oop_field(Node* n, int offset) {
116 const Type* adr_type = n->as_AddP()->bottom_type();
117 BasicType bt = T_INT;
118 if (offset == Type::OffsetBot) {
119 // Check only oop fields.
120 if (!adr_type->isa_aryptr() ||
121 (adr_type->isa_aryptr()->klass() == NULL) ||
122 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
123 // OffsetBot is used to reference array's element. Ignore first AddP.
124 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
125 bt = T_OBJECT;
126 }
127 }
128 } else if (offset != oopDesc::klass_offset_in_bytes()) {
129 if (adr_type->isa_instptr()) {
130 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
131 if (field != NULL) {
132 bt = field->layout_type();
133 } else {
134 // Ignore non field load (for example, klass load)
135 }
136 } else if (adr_type->isa_aryptr()) {
137 if (offset == arrayOopDesc::length_offset_in_bytes()) {
138 // Ignore array length load.
139 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
140 // Ignore first AddP.
141 } else {
142 const Type* elemtype = adr_type->isa_aryptr()->elem();
143 bt = elemtype->array_element_basic_type();
144 }
145 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
146 // Allocation initialization, ThreadLocal field access, unsafe access
147 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
148 int opcode = n->fast_out(i)->Opcode();
149 if (opcode == Op_StoreP || opcode == Op_LoadP ||
150 opcode == Op_StoreN || opcode == Op_LoadN) {
151 bt = T_OBJECT;
152 }
153 }
154 }
155 }
156 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
157 }
158
159 // Add all references to JavaObject node by walking over all uses.
160 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj,
161 bool populate_worklist) {
162 int new_edges = 0;
163 if (populate_worklist) {
164 // Populate _worklist by uses of jobj's uses.
165 uint count = jobj->use_count();
166 for (uint i = 0; i < count; i++) {
167 PointsToNode* use = jobj->use(i);
168 if (use->is_Arraycopy())
169 continue;
170
171 add_uses_to_worklist(use);
172 if (use->is_Field() && use->as_Field()->is_oop()) {
173 // Put on worklist all field's uses (loads) and
174 // related field nodes (same base and offset).
175 add_field_uses_to_worklist(use->as_Field());
176 }
177 }
178 }
179
180 while(_worklist.length() > 0) {
181 PointsToNode* use = _worklist.pop();
182
183 if (PointsToNode::is_base_use(use)) {
184 // Add reference from jobj to field and from field to jobj (field's base).
185 use = PointsToNode::get_use_node(use)->as_Field();
186 if (add_base(use->as_Field(), jobj))
187 new_edges++;
188 continue;
189 }
190 assert(!use->is_JavaObject(), "sanity");
191
192 if (use->is_Arraycopy()) {
193 if (jobj == null_obj) // NULL object does not have field edges
194 continue;
195
196 // Added edge from Arraycopy node to arraycopy's source java object
197 if (add_edge(use, jobj)) {
198 jobj->set_arraycopy_src();
199 new_edges++;
200 }
201 // and stop here.
202 continue;
203 }
204
205 if (!add_edge(use, jobj))
206 continue; // No new edge added, there was such edge already.
207
208 new_edges++;
209
210 if (use->is_LocalVar()) {
211 add_uses_to_worklist(use);
212 if (use->arraycopy_dst()) {
213 uint ecnt = use->edge_count();
214 for (uint j = 0; j < ecnt; j++) {
215 PointsToNode* e = use->edge(j);
216 if (e->is_Arraycopy()) {
217 if (jobj == null_obj) // NULL object does not have field edges
218 continue;
219 // Add edge from arraycopy's destination java object to Arraycopy node.
220 if (add_edge(jobj, e)) {
221 new_edges++;
222 jobj->set_arraycopy_dst();
223 }
224 }
225 }
226 }
227 } else {
228 // Added new edge to stored in field values.
229 // Put on worklist all field's uses (loads) and
230 // related field nodes (same base and offset).
231 add_field_uses_to_worklist(use->as_Field());
232 }
233 }
234 return new_edges;
235 }
236
237 // Put on worklist all related field nodes.
238 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
239 assert(field->is_oop(), "sanity");
240 int offset = field->offset();
241 add_uses_to_worklist(field);
242
243 // Loop over all bases of this field and push on worklist Field nodes
244 // with the same offset and base (since they may reference the same field).
245 uint bcnt = field->base_count();
246 for (uint i = 0; i < bcnt; i++) {
247 PointsToNode* base = field->base(i);
248 add_fields_to_worklist(field, base);
249
250 // Check if the base was source object of arraycopy and go over arraycopy's
251 // destination objects since values stored to a field of source object are
252 // accessable by uses (loads) of fields of destination objects.
253 if (base->arraycopy_src()) {
254 uint ucnt = base->use_count();
255 for (uint j = 0; j < ucnt; j++) {
256 PointsToNode* arycp = base->use(j);
257 if (arycp->is_Arraycopy()) {
258 uint acnt = arycp->use_count();
259 for (uint j = 0; j < acnt; j++) {
260 PointsToNode* abase = arycp->use(j);
261 if (abase->arraycopy_dst() && abase != base) {
262 // Look for the same arracopy reference.
263 add_fields_to_worklist(field, abase);
264 }
265 }
266 }
267 }
268 }
269 }
270 }
271
272 // Put on worklist all related field nodes.
273 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
274 int offset = field->offset();
275 if (base->is_LocalVar()) {
276 uint fcnt = base->use_count();
277 for (uint j = 0; j < fcnt; j++) {
278 PointsToNode* f = base->use(j);
279 if (PointsToNode::is_base_use(f)) { // Field
280 f = PointsToNode::get_use_node(f);
281 if (f == field || !f->as_Field()->is_oop())
282 continue;
283 int offs = f->as_Field()->offset();
284 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
285 add_to_worklist(f);
286 }
287 }
288 }
289 } else {
290 assert(base->is_JavaObject(), "sanity");
291 if (// Skip phantom_object since it is only used to indicate that
292 // this field's content globally escapes.
293 (base != phantom_obj) &&
294 // NULL object node does not have fields.
295 (base != null_obj)) {
296 uint fcnt = base->edge_count();
297 for (uint j = 0; j < fcnt; j++) {
298 PointsToNode* f = base->edge(j);
299 // Skip arraycopy edge since store to destination object field
300 // does not update value in source object field.
301 if (f->is_Arraycopy()) {
302 assert(base->arraycopy_dst(), "sanity");
303 continue;
304 }
305 if (f == field || !f->as_Field()->is_oop())
306 continue;
307 int offs = f->as_Field()->offset();
308 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
309 add_to_worklist(f);
310 }
311 }
312 }
313 }
314 }
315
316 // Returns unique pointed java object or NULL.
317 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
318 assert(!_collecting, "should not call when contructed graph");
319
320 // If the node was created after the escape computation we can't answer.
321 uint idx = n->_idx;
322 if (idx >= nodes_size())
323 return NULL;
324
325 PointsToNode* ptn = ptnode_adr(idx);
326 if (ptn->is_JavaObject()) {
327 return ptn->as_JavaObject();
328 }
329
330 assert(ptn->is_LocalVar(), "sanity");
331 // Check all java objects it points to.
332 uint count = ptn->edge_count();
333 JavaObjectNode* jobj = NULL;
334 for (uint i = 0; i < count; i++) {
335 PointsToNode* e = ptn->edge(i);
336 if (e->is_JavaObject()) {
337 if (jobj == NULL) {
338 jobj = e->as_JavaObject();
339 } else if (jobj != e) {
340 return NULL;
341 }
342 }
343 }
344 return jobj;
345 }
346
347 // Return true if nodes points only to non-escaped allocations.
348 bool PointsToNode::not_escaped_allocation() {
349 if (is_JavaObject()) {
350 Node* n = ideal_node();
351 if (n->is_Allocate() || n->is_CallStaticJava()) {
352 return (escape_state() == PointsToNode::NoEscape);
353 } else {
354 return false;
355 }
356 }
357 assert(is_LocalVar(), "sanity");
358 // Check all java objects it points to.
359 uint count = edge_count();
360 for (uint i = 0; i < count; i++) {
361 PointsToNode* e = edge(i);
362 if (e->is_JavaObject()) {
363 Node* n = e->ideal_node();
364 if ((e->escape_state() != PointsToNode::NoEscape) ||
365 !(n->is_Allocate() || n->is_CallStaticJava())) {
366 return false;
367 }
368 }
369 }
370 return true;
371 }
372
373 // Return true if we know the node does not escape globally.
374 bool ConnectionGraph::not_global_escape(Node *n) {
375 assert(!_collecting, "should not call when contructed graph");
376
377 // If the node was created after the escape computation we can't answer.
378 uint idx = n->_idx;
379 if (idx >= nodes_size())
380 return false;
381
382 PointsToNode* ptn = ptnode_adr(idx);
383 PointsToNode::EscapeState es = ptn->escape_state();
384
385 // If we have already computed a value, return it.
386 if (es >= PointsToNode::GlobalEscape)
387 return false;
388
389 if (ptn->is_JavaObject()) {
390 return (es < PointsToNode::GlobalEscape);
391 }
392
393 assert(ptn->is_LocalVar(), "sanity");
394 // Check all java objects it points to.
395 uint count = ptn->edge_count();
396 for (uint i = 0; i < count; i++) {
397 if (ptn->edge(i)->escape_state() >= PointsToNode::GlobalEscape)
398 return false;
399 }
400 return true;
401 }
402
403
404 // Helper functions
405
406 // Return true if this node points to specified node or nodes it points to.
407 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
408 if (this->is_JavaObject())
409 return (this == ptn);
410
411 assert(this->is_LocalVar(), "sanity");
412
413 uint count = this->edge_count();
414 for (uint i = 0; i < count; i++) {
415 PointsToNode* e = this->edge(i);
416 if (e == ptn)
417 return true;
418 }
419 return false;
420 }
421
422 // Return true if one node points to an other.
423 bool PointsToNode::meet(PointsToNode* ptn) {
424 if (this == ptn)
425 return true;
426
427 if (ptn->is_JavaObject())
428 return this->points_to(ptn->as_JavaObject());
429
430 if (this->is_JavaObject())
431 return ptn->points_to(this->as_JavaObject());
432
433 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
434
435 uint this_count = this->edge_count();
436 uint ptn_count = ptn->edge_count();
437 for (uint i = 0; i < this_count; i++) {
438 PointsToNode* this_e = this->edge(i);
439 for (uint j = 0; j < ptn_count; j++) {
440 PointsToNode* ptn_e = ptn->edge(j);
441 if (this_e == ptn_e)
442 return true;
443 }
444 }
445 return false;
446 }
447
448 #ifdef ASSERT
449 // Return true if bases points to this java object.
450 bool FieldNode::has_base(JavaObjectNode* jobj) const {
451 uint count = this->base_count();
452 for (uint i = 0; i < count; i++) {
453 PointsToNode* b = this->base(i);
454 if (b == jobj)
455 return true;
456 }
457 return false;
458 }
459 #endif
460
461 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
462 const Type *adr_type = phase->type(adr);
463 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
464 adr->in(AddPNode::Address)->is_Proj() &&
465 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
466 // We are computing a raw address for a store captured by an Initialize
467 // compute an appropriate address type. AddP cases #3 and #5 (see below).
468 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
469 assert(offs != Type::OffsetBot ||
470 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
471 "offset must be a constant or it is initialization of array");
472 return offs;
473 }
474 const TypePtr *t_ptr = adr_type->isa_ptr();
475 assert(t_ptr != NULL, "must be a pointer type");
476 return t_ptr->offset();
477 }
478
479 Node* ConnectionGraph::get_addp_base(Node *addp) {
480 assert(addp->is_AddP(), "must be AddP");
481 //
482 // AddP cases for Base and Address inputs:
483 // case #1. Direct object's field reference:
484 // Allocate
485 // |
486 // Proj #5 ( oop result )
487 // |
488 // CheckCastPP (cast to instance type)
489 // | |
490 // AddP ( base == address )
491 //
492 // case #2. Indirect object's field reference:
493 // Phi
494 // |
495 // CastPP (cast to instance type)
496 // | |
497 // AddP ( base == address )
498 //
499 // case #3. Raw object's field reference for Initialize node:
500 // Allocate
501 // |
502 // Proj #5 ( oop result )
503 // top |
504 // \ |
505 // AddP ( base == top )
506 //
507 // case #4. Array's element reference:
508 // {CheckCastPP | CastPP}
509 // | | |
510 // | AddP ( array's element offset )
511 // | |
512 // AddP ( array's offset )
513 //
514 // case #5. Raw object's field reference for arraycopy stub call:
515 // The inline_native_clone() case when the arraycopy stub is called
516 // after the allocation before Initialize and CheckCastPP nodes.
517 // Allocate
518 // |
519 // Proj #5 ( oop result )
520 // | |
521 // AddP ( base == address )
522 //
523 // case #6. Constant Pool, ThreadLocal, CastX2P or
524 // Raw object's field reference:
525 // {ConP, ThreadLocal, CastX2P, raw Load}
526 // top |
527 // \ |
528 // AddP ( base == top )
529 //
530 // case #7. Klass's field reference.
531 // LoadKlass
532 // | |
533 // AddP ( base == address )
534 //
535 // case #8. narrow Klass's field reference.
536 // LoadNKlass
537 // |
538 // DecodeN
539 // | |
540 // AddP ( base == address )
541 //
542 Node *base = addp->in(AddPNode::Base);
543 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
544 base = addp->in(AddPNode::Address);
545 while (base->is_AddP()) {
546 // Case #6 (unsafe access) may have several chained AddP nodes.
547 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
548 base = base->in(AddPNode::Address);
549 }
550 Node* uncast_base = base->uncast();
551 int opcode = uncast_base->Opcode();
552 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
553 opcode == Op_CastX2P || uncast_base->is_DecodeN() ||
554 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
555 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
556 }
557 return base;
558 }
559
560 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
561 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
562
563 Node* addp2 = addp->raw_out(0);
564 if (addp->outcnt() == 1 && addp2->is_AddP() &&
565 addp2->in(AddPNode::Base) == n &&
566 addp2->in(AddPNode::Address) == addp) {
567
568 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
569 //
570 // Find array's offset to push it on worklist first and
571 // as result process an array's element offset first (pushed second)
572 // to avoid CastPP for the array's offset.
573 // Otherwise the inserted CastPP (LocalVar) will point to what
574 // the AddP (Field) points to. Which would be wrong since
575 // the algorithm expects the CastPP has the same point as
576 // as AddP's base CheckCastPP (LocalVar).
577 //
578 // ArrayAllocation
579 // |
580 // CheckCastPP
581 // |
582 // memProj (from ArrayAllocation CheckCastPP)
583 // | ||
584 // | || Int (element index)
585 // | || | ConI (log(element size))
586 // | || | /
587 // | || LShift
588 // | || /
589 // | AddP (array's element offset)
590 // | |
591 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
592 // | / /
593 // AddP (array's offset)
594 // |
595 // Load/Store (memory operation on array's element)
596 //
597 return addp2;
598 }
599 return NULL;
600 }
601
602 //
603 // Adjust the type and inputs of an AddP which computes the
604 // address of a field of an instance
605 //
606 bool ConnectionGraph::split_AddP(Node *addp, Node *base, PhaseGVN *igvn) {
607 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
608 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
609 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
610 if (t == NULL) {
611 // We are computing a raw address for a store captured by an Initialize
612 // compute an appropriate address type (cases #3 and #5).
613 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
614 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
615 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
616 assert(offs != Type::OffsetBot, "offset must be a constant");
617 t = base_t->add_offset(offs)->is_oopptr();
618 }
619 int inst_id = base_t->instance_id();
620 assert(!t->is_known_instance() || t->instance_id() == inst_id,
621 "old type must be non-instance or match new type");
622
623 // The type 't' could be subclass of 'base_t'.
624 // As result t->offset() could be large then base_t's size and it will
625 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
626 // constructor verifies correctness of the offset.
627 //
628 // It could happened on subclass's branch (from the type profiling
629 // inlining) which was not eliminated during parsing since the exactness
630 // of the allocation type was not propagated to the subclass type check.
631 //
632 // Or the type 't' could be not related to 'base_t' at all.
633 // It could happened when CHA type is different from MDO type on a dead path
634 // (for example, from instanceof check) which is not collapsed during parsing.
635 //
636 // Do nothing for such AddP node and don't process its users since
637 // this code branch will go away.
638 //
639 if (!t->is_known_instance() &&
640 !base_t->klass()->is_subtype_of(t->klass())) {
641 return false; // bail out
642 }
643
644 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
645 // Do NOT remove the next line: ensure a new alias index is allocated
646 // for the instance type. Note: C++ will not remove it since the call
647 // has side effect.
648 int alias_idx = _compile->get_alias_index(tinst);
649 igvn->set_type(addp, tinst);
650 // record the allocation in the node map
651 set_map(addp, get_map(base->_idx));
652
653 // Set addp's Base and Address to 'base'.
654 Node *abase = addp->in(AddPNode::Base);
655 Node *adr = addp->in(AddPNode::Address);
656 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
657 adr->in(0)->_idx == (uint)inst_id) {
658 // Skip AddP cases #3 and #5.
659 } else {
660 assert(!abase->is_top(), "sanity"); // AddP case #3
661 if (abase != base) {
662 igvn->hash_delete(addp);
663 addp->set_req(AddPNode::Base, base);
664 if (abase == adr) {
665 addp->set_req(AddPNode::Address, base);
666 } else {
667 // AddP case #4 (adr is array's element offset AddP node)
668 #ifdef ASSERT
669 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
670 assert(adr->is_AddP() && atype != NULL &&
671 atype->instance_id() == inst_id, "array's element offset should be processed first");
672 #endif
673 }
674 igvn->hash_insert(addp);
675 }
676 }
677 // Put on IGVN worklist since at least addp's type was changed above.
678 record_for_optimizer(addp);
679 return true;
680 }
681
682 //
683 // Create a new version of orig_phi if necessary. Returns either the newly
684 // created phi or an existing phi. Sets create_new to indicate whether a new
685 // phi was created. Cache the last newly created phi in the node map.
686 //
687 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created) {
688 Compile *C = _compile;
689 new_created = false;
690 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
691 // nothing to do if orig_phi is bottom memory or matches alias_idx
692 if (phi_alias_idx == alias_idx) {
693 return orig_phi;
694 }
695 // Have we recently created a Phi for this alias index?
696 PhiNode *result = get_map_phi(orig_phi->_idx);
697 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
698 return result;
699 }
700 // Previous check may fail when the same wide memory Phi was split into Phis
701 // for different memory slices. Search all Phis for this region.
702 if (result != NULL) {
703 Node* region = orig_phi->in(0);
704 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
705 Node* phi = region->fast_out(i);
706 if (phi->is_Phi() &&
707 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
708 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
709 return phi->as_Phi();
710 }
711 }
712 }
713 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
714 if (C->do_escape_analysis() == true && !C->failing()) {
715 // Retry compilation without escape analysis.
716 // If this is the first failure, the sentinel string will "stick"
717 // to the Compile object, and the C2Compiler will see it and retry.
718 C->record_failure(C2Compiler::retry_no_escape_analysis());
719 }
720 return NULL;
721 }
722 orig_phi_worklist.append_if_missing(orig_phi);
723 const TypePtr *atype = C->get_adr_type(alias_idx);
724 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
725 C->copy_node_notes_to(result, orig_phi);
726 igvn->set_type(result, result->bottom_type());
727 record_for_optimizer(result);
728
729 set_map(orig_phi, result);
730
731 new_created = true;
732 return result;
733 }
734
735 //
736 // Return a new version of Memory Phi "orig_phi" with the inputs having the
737 // specified alias index.
738 //
739 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
740
741 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
742 Compile *C = _compile;
743 bool new_phi_created;
744 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
745 if (!new_phi_created) {
746 return result;
747 }
748
749 GrowableArray<PhiNode *> phi_list;
750 GrowableArray<uint> cur_input;
751
752 PhiNode *phi = orig_phi;
753 uint idx = 1;
754 bool finished = false;
755 while(!finished) {
756 while (idx < phi->req()) {
757 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
758 if (mem != NULL && mem->is_Phi()) {
759 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
760 if (new_phi_created) {
761 // found an phi for which we created a new split, push current one on worklist and begin
762 // processing new one
763 phi_list.push(phi);
764 cur_input.push(idx);
765 phi = mem->as_Phi();
766 result = newphi;
767 idx = 1;
768 continue;
769 } else {
770 mem = newphi;
771 }
772 }
773 if (C->failing()) {
774 return NULL;
775 }
776 result->set_req(idx++, mem);
777 }
778 #ifdef ASSERT
779 // verify that the new Phi has an input for each input of the original
780 assert( phi->req() == result->req(), "must have same number of inputs.");
781 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
782 #endif
783 // Check if all new phi's inputs have specified alias index.
784 // Otherwise use old phi.
785 for (uint i = 1; i < phi->req(); i++) {
786 Node* in = result->in(i);
787 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
788 }
789 // we have finished processing a Phi, see if there are any more to do
790 finished = (phi_list.length() == 0 );
791 if (!finished) {
792 phi = phi_list.pop();
793 idx = cur_input.pop();
794 PhiNode *prev_result = get_map_phi(phi->_idx);
795 prev_result->set_req(idx++, result);
796 result = prev_result;
797 }
798 }
799 return result;
800 }
801
802
803 //
804 // The next methods are derived from methods in MemNode.
805 //
806 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
807 Node *mem = mmem;
808 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
809 // means an array I have not precisely typed yet. Do not do any
810 // alias stuff with it any time soon.
811 if (toop->base() != Type::AnyPtr &&
812 !(toop->klass() != NULL &&
813 toop->klass()->is_java_lang_Object() &&
814 toop->offset() == Type::OffsetBot)) {
815 mem = mmem->memory_at(alias_idx);
816 // Update input if it is progress over what we have now
817 }
818 return mem;
819 }
820
821 //
822 // Move memory users to their memory slices.
823 //
824 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *igvn) {
825 Compile* C = _compile;
826
827 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
828 assert(tp != NULL, "ptr type");
829 int alias_idx = C->get_alias_index(tp);
830 int general_idx = C->get_general_index(alias_idx);
831
832 // Move users first
833 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
834 Node* use = n->fast_out(i);
835 if (use->is_MergeMem()) {
836 MergeMemNode* mmem = use->as_MergeMem();
837 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
838 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
839 continue; // Nothing to do
840 }
841 // Replace previous general reference to mem node.
842 uint orig_uniq = C->unique();
843 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
844 assert(orig_uniq == C->unique(), "no new nodes");
845 mmem->set_memory_at(general_idx, m);
846 --imax;
847 --i;
848 } else if (use->is_MemBar()) {
849 assert(!use->is_Initialize(), "initializing stores should not be moved");
850 if (use->req() > MemBarNode::Precedent &&
851 use->in(MemBarNode::Precedent) == n) {
852 // Don't move related membars.
853 record_for_optimizer(use);
854 continue;
855 }
856 tp = use->as_MemBar()->adr_type()->isa_ptr();
857 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
858 alias_idx == general_idx) {
859 continue; // Nothing to do
860 }
861 // Move to general memory slice.
862 uint orig_uniq = C->unique();
863 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
864 assert(orig_uniq == C->unique(), "no new nodes");
865 igvn->hash_delete(use);
866 imax -= use->replace_edge(n, m);
867 igvn->hash_insert(use);
868 record_for_optimizer(use);
869 --i;
870 #ifdef ASSERT
871 } else if (use->is_Mem()) {
872 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
873 // Don't move related cardmark.
874 continue;
875 }
876 // Memory nodes should have new memory input.
877 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
878 assert(tp != NULL, "ptr type");
879 int idx = C->get_alias_index(tp);
880 assert(get_map(use->_idx) != NULL || idx == alias_idx,
881 "Following memory nodes should have new memory input or be on the same memory slice");
882 } else if (use->is_Phi()) {
883 // Phi nodes should be split and moved already.
884 tp = use->as_Phi()->adr_type()->isa_ptr();
885 assert(tp != NULL, "ptr type");
886 int idx = C->get_alias_index(tp);
887 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
888 } else {
889 use->dump();
890 assert(false, "should not be here");
891 #endif
892 }
893 }
894 }
895
896 //
897 // Search memory chain of "mem" to find a MemNode whose address
898 // is the specified alias index.
899 //
900 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *phase) {
901 if (orig_mem == NULL)
902 return orig_mem;
903 Compile* C = phase->C;
904 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
905 bool is_instance = (toop != NULL) && toop->is_known_instance();
906 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
907 Node *prev = NULL;
908 Node *result = orig_mem;
909 while (prev != result) {
910 prev = result;
911 if (result == start_mem)
912 break; // hit one of our sentinels
913 if (result->is_Mem()) {
914 const Type *at = phase->type(result->in(MemNode::Address));
915 if (at == Type::TOP)
916 break; // Dead
917 assert (at->isa_ptr() != NULL, "pointer type required.");
918 int idx = C->get_alias_index(at->is_ptr());
919 if (idx == alias_idx)
920 break; // Found
921 if (!is_instance && (at->isa_oopptr() == NULL ||
922 !at->is_oopptr()->is_known_instance())) {
923 break; // Do not skip store to general memory slice.
924 }
925 result = result->in(MemNode::Memory);
926 }
927 if (!is_instance)
928 continue; // don't search further for non-instance types
929 // skip over a call which does not affect this memory slice
930 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
931 Node *proj_in = result->in(0);
932 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
933 break; // hit one of our sentinels
934 } else if (proj_in->is_Call()) {
935 CallNode *call = proj_in->as_Call();
936 if (!call->may_modify(toop, phase)) {
937 result = call->in(TypeFunc::Memory);
938 }
939 } else if (proj_in->is_Initialize()) {
940 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
941 // Stop if this is the initialization for the object instance which
942 // which contains this memory slice, otherwise skip over it.
943 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
944 result = proj_in->in(TypeFunc::Memory);
945 }
946 } else if (proj_in->is_MemBar()) {
947 result = proj_in->in(TypeFunc::Memory);
948 }
949 } else if (result->is_MergeMem()) {
950 MergeMemNode *mmem = result->as_MergeMem();
951 result = step_through_mergemem(mmem, alias_idx, toop);
952 if (result == mmem->base_memory()) {
953 // Didn't find instance memory, search through general slice recursively.
954 result = mmem->memory_at(C->get_general_index(alias_idx));
955 result = find_inst_mem(result, alias_idx, orig_phis, phase);
956 if (C->failing()) {
957 return NULL;
958 }
959 mmem->set_memory_at(alias_idx, result);
960 }
961 } else if (result->is_Phi() &&
962 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
963 Node *un = result->as_Phi()->unique_input(phase);
964 if (un != NULL) {
965 orig_phis.append_if_missing(result->as_Phi());
966 result = un;
967 } else {
968 break;
969 }
970 } else if (result->is_ClearArray()) {
971 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
972 // Can not bypass initialization of the instance
973 // we are looking for.
974 break;
975 }
976 // Otherwise skip it (the call updated 'result' value).
977 } else if (result->Opcode() == Op_SCMemProj) {
978 assert(result->in(0)->is_LoadStore(), "sanity");
979 const Type *at = phase->type(result->in(0)->in(MemNode::Address));
980 if (at != Type::TOP) {
981 assert (at->isa_ptr() != NULL, "pointer type required.");
982 int idx = C->get_alias_index(at->is_ptr());
983 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
984 break;
985 }
986 result = result->in(0)->in(MemNode::Memory);
987 }
988 }
989 if (result->is_Phi()) {
990 PhiNode *mphi = result->as_Phi();
991 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
992 const TypePtr *t = mphi->adr_type();
993 if (!is_instance) {
994 // Push all non-instance Phis on the orig_phis worklist to update inputs
995 // during Phase 4 if needed.
996 orig_phis.append_if_missing(mphi);
997 } else if (C->get_alias_index(t) != alias_idx) {
998 // Create a new Phi with the specified alias index type.
999 result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
1000 }
1001 }
1002 // the result is either MemNode, PhiNode, InitializeNode.
1003 return result;
1004 }
1005
1006 //
1007 // Convert the types of unescaped object to instance types where possible,
1008 // propagate the new type information through the graph, and update memory
1009 // edges and MergeMem inputs to reflect the new type.
1010 //
1011 // We start with allocations (and calls which may be allocations) on alloc_worklist.
1012 // The processing is done in 4 phases:
1013 //
1014 // Phase 1: Process possible allocations from alloc_worklist. Create instance
1015 // types for the CheckCastPP for allocations where possible.
1016 // Propagate the the new types through users as follows:
1017 // casts and Phi: push users on alloc_worklist
1018 // AddP: cast Base and Address inputs to the instance type
1019 // push any AddP users on alloc_worklist and push any memnode
1020 // users onto memnode_worklist.
1021 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1022 // search the Memory chain for a store with the appropriate type
1023 // address type. If a Phi is found, create a new version with
1024 // the appropriate memory slices from each of the Phi inputs.
1025 // For stores, process the users as follows:
1026 // MemNode: push on memnode_worklist
1027 // MergeMem: push on mergemem_worklist
1028 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
1029 // moving the first node encountered of each instance type to the
1030 // the input corresponding to its alias index.
1031 // appropriate memory slice.
1032 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
1033 //
1034 // In the following example, the CheckCastPP nodes are the cast of allocation
1035 // results and the allocation of node 29 is unescaped and eligible to be an
1036 // instance type.
1037 //
1038 // We start with:
1039 //
1040 // 7 Parm #memory
1041 // 10 ConI "12"
1042 // 19 CheckCastPP "Foo"
1043 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
1044 // 29 CheckCastPP "Foo"
1045 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
1046 //
1047 // 40 StoreP 25 7 20 ... alias_index=4
1048 // 50 StoreP 35 40 30 ... alias_index=4
1049 // 60 StoreP 45 50 20 ... alias_index=4
1050 // 70 LoadP _ 60 30 ... alias_index=4
1051 // 80 Phi 75 50 60 Memory alias_index=4
1052 // 90 LoadP _ 80 30 ... alias_index=4
1053 // 100 LoadP _ 80 20 ... alias_index=4
1054 //
1055 //
1056 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
1057 // and creating a new alias index for node 30. This gives:
1058 //
1059 // 7 Parm #memory
1060 // 10 ConI "12"
1061 // 19 CheckCastPP "Foo"
1062 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
1063 // 29 CheckCastPP "Foo" iid=24
1064 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
1065 //
1066 // 40 StoreP 25 7 20 ... alias_index=4
1067 // 50 StoreP 35 40 30 ... alias_index=6
1068 // 60 StoreP 45 50 20 ... alias_index=4
1069 // 70 LoadP _ 60 30 ... alias_index=6
1070 // 80 Phi 75 50 60 Memory alias_index=4
1071 // 90 LoadP _ 80 30 ... alias_index=6
1072 // 100 LoadP _ 80 20 ... alias_index=4
1073 //
1074 // In phase 2, new memory inputs are computed for the loads and stores,
1075 // And a new version of the phi is created. In phase 4, the inputs to
1076 // node 80 are updated and then the memory nodes are updated with the
1077 // values computed in phase 2. This results in:
1078 //
1079 // 7 Parm #memory
1080 // 10 ConI "12"
1081 // 19 CheckCastPP "Foo"
1082 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
1083 // 29 CheckCastPP "Foo" iid=24
1084 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
1085 //
1086 // 40 StoreP 25 7 20 ... alias_index=4
1087 // 50 StoreP 35 7 30 ... alias_index=6
1088 // 60 StoreP 45 40 20 ... alias_index=4
1089 // 70 LoadP _ 50 30 ... alias_index=6
1090 // 80 Phi 75 40 60 Memory alias_index=4
1091 // 120 Phi 75 50 50 Memory alias_index=6
1092 // 90 LoadP _ 120 30 ... alias_index=6
1093 // 100 LoadP _ 80 20 ... alias_index=4
1094 //
1095 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
1096 GrowableArray<Node *> memnode_worklist;
1097 GrowableArray<PhiNode *> orig_phis;
1098
1099 PhaseIterGVN *igvn = _igvn;
1100 uint new_index_start = (uint) _compile->num_alias_types();
1101 Arena* arena = Thread::current()->resource_area();
1102 VectorSet visited(arena);
1103
1104 ideal_nodes.clear(); // Reset for use with set_map/get_map.
1105
1106 uint unique_old = _compile->unique();
1107
1108 // Phase 1: Process possible allocations from alloc_worklist.
1109 // Create instance types for the CheckCastPP for allocations where possible.
1110 //
1111 // (Note: don't forget to change the order of the second AddP node on
1112 // the alloc_worklist if the order of the worklist processing is changed,
1113 // see the comment in find_second_addp().)
1114 //
1115 while (alloc_worklist.length() != 0) {
1116 Node *n = alloc_worklist.pop();
1117 uint ni = n->_idx;
1118 if (n->is_Call()) {
1119 CallNode *alloc = n->as_Call();
1120 // copy escape information to call node
1121 PointsToNode* ptn = ptnode_adr(alloc->_idx);
1122 PointsToNode::EscapeState es = ptn->escape_state();
1123 // We have an allocation or call which returns a Java object,
1124 // see if it is unescaped.
1125 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
1126 continue;
1127
1128 // Find CheckCastPP for the allocate or for the return value of a call
1129 n = alloc->result_cast();
1130 if (n == NULL) { // No uses except Initialize node
1131 if (alloc->is_Allocate()) {
1132 // Set the scalar_replaceable flag for allocation
1133 // so it could be eliminated if it has no uses.
1134 alloc->as_Allocate()->_is_scalar_replaceable = true;
1135 }
1136 continue;
1137 }
1138 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1139 assert(!alloc->is_Allocate(), "allocation should have unique type");
1140 continue;
1141 }
1142
1143 // The inline code for Object.clone() casts the allocation result to
1144 // java.lang.Object and then to the actual type of the allocated
1145 // object. Detect this case and use the second cast.
1146 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
1147 // the allocation result is cast to java.lang.Object and then
1148 // to the actual Array type.
1149 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
1150 && (alloc->is_AllocateArray() ||
1151 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
1152 Node *cast2 = NULL;
1153 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1154 Node *use = n->fast_out(i);
1155 if (use->is_CheckCastPP()) {
1156 cast2 = use;
1157 break;
1158 }
1159 }
1160 if (cast2 != NULL) {
1161 n = cast2;
1162 } else {
1163 // Non-scalar replaceable if the allocation type is unknown statically
1164 // (reflection allocation), the object can't be restored during
1165 // deoptimization without precise type.
1166 continue;
1167 }
1168 }
1169 if (alloc->is_Allocate()) {
1170 // Set the scalar_replaceable flag for allocation
1171 // so it could be eliminated.
1172 alloc->as_Allocate()->_is_scalar_replaceable = true;
1173 }
1174 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
1175 // in order for an object to be scalar-replaceable, it must be:
1176 // - a direct allocation (not a call returning an object)
1177 // - non-escaping
1178 // - eligible to be a unique type
1179 // - not determined to be ineligible by escape analysis
1180 set_map(alloc, n);
1181 set_map(n, alloc);
1182 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1183 if (t == NULL)
1184 continue; // not a TypeOopPtr
1185 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1186 igvn->hash_delete(n);
1187 igvn->set_type(n, tinst);
1188 n->raise_bottom_type(tinst);
1189 igvn->hash_insert(n);
1190 record_for_optimizer(n);
1191 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
1192
1193 // First, put on the worklist all Field edges from Connection Graph
1194 // which is more accurate then putting immediate users from Ideal Graph.
1195 for (uint e = 0; e < ptn->edge_count(); e++) {
1196 PointsToNode* tgt = ptn->edge(e);
1197 Node* use = tgt->ideal_node();
1198 assert(tgt->is_Field() && use->is_AddP(),
1199 "only AddP nodes are Field edges in CG");
1200 if (use->outcnt() > 0) { // Don't process dead nodes
1201 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1202 if (addp2 != NULL) {
1203 assert(alloc->is_AllocateArray(),"array allocation was expected");
1204 alloc_worklist.append_if_missing(addp2);
1205 }
1206 alloc_worklist.append_if_missing(use);
1207 }
1208 }
1209
1210 // An allocation may have an Initialize which has raw stores. Scan
1211 // the users of the raw allocation result and push AddP users
1212 // on alloc_worklist.
1213 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1214 assert (raw_result != NULL, "must have an allocation result");
1215 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1216 Node *use = raw_result->fast_out(i);
1217 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1218 Node* addp2 = find_second_addp(use, raw_result);
1219 if (addp2 != NULL) {
1220 assert(alloc->is_AllocateArray(),"array allocation was expected");
1221 alloc_worklist.append_if_missing(addp2);
1222 }
1223 alloc_worklist.append_if_missing(use);
1224 } else if (use->is_MemBar()) {
1225 memnode_worklist.append_if_missing(use);
1226 }
1227 }
1228 }
1229 } else if (n->is_AddP()) {
1230 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
1231 if (jobj == NULL || jobj == phantom_obj) {
1232 #ifdef ASSERT
1233 ptnode_adr(get_addp_base(n)->_idx)->dump();
1234 ptnode_adr(n->_idx)->dump();
1235 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
1236 #endif
1237 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
1238 return;
1239 }
1240 Node *base = get_map(jobj->idx()); // CheckCastPP node
1241 if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1242 } else if (n->is_Phi() ||
1243 n->is_CheckCastPP() ||
1244 n->is_EncodeP() ||
1245 n->is_DecodeN() ||
1246 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1247 if (visited.test_set(n->_idx)) {
1248 assert(n->is_Phi(), "loops only through Phi's");
1249 continue; // already processed
1250 }
1251 JavaObjectNode* jobj = unique_java_object(n);
1252 if (jobj == NULL || jobj == phantom_obj) {
1253 #ifdef ASSERT
1254 ptnode_adr(n->_idx)->dump();
1255 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
1256 #endif
1257 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
1258 return;
1259 } else {
1260 Node *val = get_map(jobj->idx()); // CheckCastPP node
1261 TypeNode *tn = n->as_Type();
1262 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
1263 assert(tinst != NULL && tinst->is_known_instance() &&
1264 tinst->instance_id() == jobj->idx() , "instance type expected.");
1265
1266 const Type *tn_type = igvn->type(tn);
1267 const TypeOopPtr *tn_t;
1268 if (tn_type->isa_narrowoop()) {
1269 tn_t = tn_type->make_ptr()->isa_oopptr();
1270 } else {
1271 tn_t = tn_type->isa_oopptr();
1272 }
1273
1274 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1275 if (tn_type->isa_narrowoop()) {
1276 tn_type = tinst->make_narrowoop();
1277 } else {
1278 tn_type = tinst;
1279 }
1280 igvn->hash_delete(tn);
1281 igvn->set_type(tn, tn_type);
1282 tn->set_type(tn_type);
1283 igvn->hash_insert(tn);
1284 record_for_optimizer(n);
1285 } else {
1286 assert(tn_type == TypePtr::NULL_PTR ||
1287 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
1288 "unexpected type");
1289 continue; // Skip dead path with different type
1290 }
1291 }
1292 } else {
1293 debug_only(n->dump();)
1294 assert(false, "EA: unexpected node");
1295 continue;
1296 }
1297 // push allocation's users on appropriate worklist
1298 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1299 Node *use = n->fast_out(i);
1300 if(use->is_Mem() && use->in(MemNode::Address) == n) {
1301 // Load/store to instance's field
1302 memnode_worklist.append_if_missing(use);
1303 } else if (use->is_MemBar()) {
1304 memnode_worklist.append_if_missing(use);
1305 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1306 Node* addp2 = find_second_addp(use, n);
1307 if (addp2 != NULL) {
1308 alloc_worklist.append_if_missing(addp2);
1309 }
1310 alloc_worklist.append_if_missing(use);
1311 } else if (use->is_Phi() ||
1312 use->is_CheckCastPP() ||
1313 use->is_EncodeP() ||
1314 use->is_DecodeN() ||
1315 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1316 alloc_worklist.append_if_missing(use);
1317 #ifdef ASSERT
1318 } else if (use->is_Mem()) {
1319 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
1320 } else if (use->is_MergeMem()) {
1321 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1322 } else if (use->is_SafePoint()) {
1323 // Look for MergeMem nodes for calls which reference unique allocation
1324 // (through CheckCastPP nodes) even for debug info.
1325 Node* m = use->in(TypeFunc::Memory);
1326 if (m->is_MergeMem()) {
1327 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1328 }
1329 } else {
1330 uint op = use->Opcode();
1331 if (!(op == Op_CmpP || op == Op_Conv2B ||
1332 op == Op_CastP2X || op == Op_StoreCM ||
1333 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1334 op == Op_StrEquals || op == Op_StrIndexOf)) {
1335 n->dump();
1336 use->dump();
1337 assert(false, "EA: missing allocation reference path");
1338 }
1339 #endif
1340 }
1341 }
1342
1343 }
1344 // New alias types were created in split_AddP().
1345 uint new_index_end = (uint) _compile->num_alias_types();
1346
1347 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
1348
1349 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1350 // compute new values for Memory inputs (the Memory inputs are not
1351 // actually updated until phase 4.)
1352 if (memnode_worklist.length() == 0)
1353 return; // nothing to do
1354
1355 while (memnode_worklist.length() != 0) {
1356 Node *n = memnode_worklist.pop();
1357 if (visited.test_set(n->_idx))
1358 continue;
1359 if (n->is_Phi() || n->is_ClearArray()) {
1360 // we don't need to do anything, but the users must be pushed
1361 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1362 // we don't need to do anything, but the users must be pushed
1363 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1364 if (n == NULL)
1365 continue;
1366 } else {
1367 assert(n->is_Mem(), "memory node required.");
1368 Node *addr = n->in(MemNode::Address);
1369 const Type *addr_t = igvn->type(addr);
1370 if (addr_t == Type::TOP)
1371 continue;
1372 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1373 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1374 assert ((uint)alias_idx < new_index_end, "wrong alias index");
1375 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1376 if (_compile->failing()) {
1377 return;
1378 }
1379 if (mem != n->in(MemNode::Memory)) {
1380 // We delay the memory edge update since we need old one in
1381 // MergeMem code below when instances memory slices are separated.
1382 set_map(n, mem);
1383 }
1384 if (n->is_Load()) {
1385 continue; // don't push users
1386 } else if (n->is_LoadStore()) {
1387 // get the memory projection
1388 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1389 Node *use = n->fast_out(i);
1390 if (use->Opcode() == Op_SCMemProj) {
1391 n = use;
1392 break;
1393 }
1394 }
1395 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1396 }
1397 }
1398 // push user on appropriate worklist
1399 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1400 Node *use = n->fast_out(i);
1401 if (use->is_Phi() || use->is_ClearArray()) {
1402 memnode_worklist.append_if_missing(use);
1403 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1404 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
1405 continue;
1406 memnode_worklist.append_if_missing(use);
1407 } else if (use->is_MemBar()) {
1408 memnode_worklist.append_if_missing(use);
1409 #ifdef ASSERT
1410 } else if(use->is_Mem()) {
1411 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
1412 } else if (use->is_MergeMem()) {
1413 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1414 } else {
1415 uint op = use->Opcode();
1416 if (!(op == Op_StoreCM ||
1417 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
1418 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
1419 op == Op_AryEq || op == Op_StrComp ||
1420 op == Op_StrEquals || op == Op_StrIndexOf)) {
1421 n->dump();
1422 use->dump();
1423 assert(false, "EA: missing memory path");
1424 }
1425 #endif
1426 }
1427 }
1428 }
1429
1430 // Phase 3: Process MergeMem nodes from mergemem_worklist.
1431 // Walk each memory slice moving the first node encountered of each
1432 // instance type to the the input corresponding to its alias index.
1433 uint length = _mergemem_worklist.length();
1434 for( uint next = 0; next < length; ++next ) {
1435 MergeMemNode* nmm = _mergemem_worklist.at(next);
1436 assert(!visited.test_set(nmm->_idx), "should not be visited before");
1437 // Note: we don't want to use MergeMemStream here because we only want to
1438 // scan inputs which exist at the start, not ones we add during processing.
1439 // Note 2: MergeMem may already contains instance memory slices added
1440 // during find_inst_mem() call when memory nodes were processed above.
1441 igvn->hash_delete(nmm);
1442 uint nslices = nmm->req();
1443 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1444 Node* mem = nmm->in(i);
1445 Node* cur = NULL;
1446 if (mem == NULL || mem->is_top())
1447 continue;
1448 // First, update mergemem by moving memory nodes to corresponding slices
1449 // if their type became more precise since this mergemem was created.
1450 while (mem->is_Mem()) {
1451 const Type *at = igvn->type(mem->in(MemNode::Address));
1452 if (at != Type::TOP) {
1453 assert (at->isa_ptr() != NULL, "pointer type required.");
1454 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1455 if (idx == i) {
1456 if (cur == NULL)
1457 cur = mem;
1458 } else {
1459 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1460 nmm->set_memory_at(idx, mem);
1461 }
1462 }
1463 }
1464 mem = mem->in(MemNode::Memory);
1465 }
1466 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1467 // Find any instance of the current type if we haven't encountered
1468 // already a memory slice of the instance along the memory chain.
1469 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1470 if((uint)_compile->get_general_index(ni) == i) {
1471 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1472 if (nmm->is_empty_memory(m)) {
1473 Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1474 if (_compile->failing()) {
1475 return;
1476 }
1477 nmm->set_memory_at(ni, result);
1478 }
1479 }
1480 }
1481 }
1482 // Find the rest of instances values
1483 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1484 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
1485 Node* result = step_through_mergemem(nmm, ni, tinst);
1486 if (result == nmm->base_memory()) {
1487 // Didn't find instance memory, search through general slice recursively.
1488 result = nmm->memory_at(_compile->get_general_index(ni));
1489 result = find_inst_mem(result, ni, orig_phis, igvn);
1490 if (_compile->failing()) {
1491 return;
1492 }
1493 nmm->set_memory_at(ni, result);
1494 }
1495 }
1496 igvn->hash_insert(nmm);
1497 record_for_optimizer(nmm);
1498 }
1499
1500 // Phase 4: Update the inputs of non-instance memory Phis and
1501 // the Memory input of memnodes
1502 // First update the inputs of any non-instance Phi's from
1503 // which we split out an instance Phi. Note we don't have
1504 // to recursively process Phi's encounted on the input memory
1505 // chains as is done in split_memory_phi() since they will
1506 // also be processed here.
1507 for (int j = 0; j < orig_phis.length(); j++) {
1508 PhiNode *phi = orig_phis.at(j);
1509 int alias_idx = _compile->get_alias_index(phi->adr_type());
1510 igvn->hash_delete(phi);
1511 for (uint i = 1; i < phi->req(); i++) {
1512 Node *mem = phi->in(i);
1513 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1514 if (_compile->failing()) {
1515 return;
1516 }
1517 if (mem != new_mem) {
1518 phi->set_req(i, new_mem);
1519 }
1520 }
1521 igvn->hash_insert(phi);
1522 record_for_optimizer(phi);
1523 }
1524
1525 // Update the memory inputs of MemNodes with the value we computed
1526 // in Phase 2 and move stores memory users to corresponding memory slices.
1527
1528 // Disable memory split verification code until the fix for 6984348.
1529 // Currently it produces false negative results since it does not cover all cases.
1530 #if 0 // ifdef ASSERT
1531 visited.Reset();
1532 Node_Stack old_mems(arena, _compile->unique() >> 2);
1533 #endif
1534 for (uint i = 0; i < ideal_nodes.size(); i++) {
1535 Node* n = ideal_nodes.at(i);
1536 Node* nmem = get_map(n->_idx);
1537 assert(nmem != NULL, "sanity");
1538 if (n->is_Mem()) {
1539 #if 0 // ifdef ASSERT
1540 Node* old_mem = n->in(MemNode::Memory);
1541 if (!visited.test_set(old_mem->_idx)) {
1542 old_mems.push(old_mem, old_mem->outcnt());
1543 }
1544 #endif
1545 assert(n->in(MemNode::Memory) != nmem, "sanity");
1546 if (!n->is_Load()) {
1547 // Move memory users of a store first.
1548 move_inst_mem(n, orig_phis, igvn);
1549 }
1550 // Now update memory input
1551 igvn->hash_delete(n);
1552 n->set_req(MemNode::Memory, nmem);
1553 igvn->hash_insert(n);
1554 record_for_optimizer(n);
1555 } else {
1556 assert(n->is_Allocate() || n->is_CheckCastPP() ||
1557 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1558 }
1559 }
1560 #if 0 // ifdef ASSERT
1561 // Verify that memory was split correctly
1562 while (old_mems.is_nonempty()) {
1563 Node* old_mem = old_mems.node();
1564 uint old_cnt = old_mems.index();
1565 old_mems.pop();
1566 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
1567 }
1568 #endif
1569 }
1570
1571 bool ConnectionGraph::has_candidates(Compile *C) {
1572 // EA brings benefits only when the code has allocations and/or locks which
1573 // are represented by ideal Macro nodes.
1574 int cnt = C->macro_count();
1575 for( int i=0; i < cnt; i++ ) {
1576 Node *n = C->macro_node(i);
1577 if ( n->is_Allocate() )
1578 return true;
1579 if( n->is_Lock() ) {
1580 Node* obj = n->as_Lock()->obj_node()->uncast();
1581 if( !(obj->is_Parm() || obj->is_Con()) )
1582 return true;
1583 }
1584 }
1585 return false;
1586 }
1587
1588 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1589 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
1590
1591 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1592 // to create space for them in ConnectionGraph::_nodes[].
1593 Node* oop_null = igvn->zerocon(T_OBJECT);
1594 Node* noop_null = igvn->zerocon(T_NARROWOOP);
1595
1596 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1597 // Perform escape analysis
1598 if (congraph->compute_escape()) {
1599 // There are non escaping objects.
1600 C->set_congraph(congraph);
1601 }
1602
1603 // Cleanup.
1604 if (oop_null->outcnt() == 0)
1605 igvn->hash_delete(oop_null);
1606 if (noop_null->outcnt() == 0)
1607 igvn->hash_delete(noop_null);
1608 }
1609
1610 bool ConnectionGraph::compute_escape() {
1611 Compile* C = _compile;
1612 PhaseGVN* igvn = _igvn;
1613
1614 // 1. Populate Connection Graph (CG) with PointsTo nodes.
1615
1616 ideal_nodes.map(C->unique(), NULL); // preallocate space
1617
1618 // Initialize worklist
1619 if (C->root() != NULL) {
1620 ideal_nodes.push(C->root());
1621 }
1622
1623 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
1624
1625 Unique_Node_List delayed_worklist;
1626 GrowableArray<Node*> alloc_worklist;
1627 GrowableArray<Node*> ptr_cmp_worklist;
1628 GrowableArray<Node*> storestore_worklist;
1629
1630 GrowableArray<PointsToNode*> ptnodes_worklist;
1631 GrowableArray<JavaObjectNode*> java_objects_worklist;
1632 GrowableArray<JavaObjectNode*> non_escaped_worklist;
1633 GrowableArray<FieldNode*> oop_fields_worklist;
1634
1635 { Compile::TracePhase t3("buildConnectionGraph", &Phase::_t_buildConnectionGraph, true);
1636
1637 // Push all useful nodes onto CG list and set their type.
1638 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
1639 Node* n = ideal_nodes.at(next);
1640
1641 // It is called only once per node since ideal_nodes is Unique_Node list.
1642 build_connection_graph(n, &delayed_worklist, igvn);
1643
1644 PointsToNode* ptn = ptnode_adr(n->_idx);
1645 if (ptn != NULL) {
1646 ptnodes_worklist.append(ptn);
1647 if (ptn->is_JavaObject()) {
1648 java_objects_worklist.append(ptn->as_JavaObject());
1649 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
1650 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
1651 // Only allocations and java static calls results are interesting.
1652 non_escaped_worklist.append(ptn->as_JavaObject());
1653 }
1654 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
1655 oop_fields_worklist.append(ptn->as_Field());
1656 }
1657 }
1658 if (n->is_MergeMem()) {
1659 // Collect all MergeMem nodes to add memory slices for
1660 // scalar replaceable objects in split_unique_types().
1661 _mergemem_worklist.append(n->as_MergeMem());
1662 } else if (OptimizePtrCompare && n->is_Cmp() &&
1663 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
1664 // Compare pointers nodes
1665 ptr_cmp_worklist.append(n);
1666 } else if (n->is_MemBarStoreStore()) {
1667 // Collect all MemBarStoreStore nodes so that depending on the
1668 // escape status of the associated Allocate node some of them
1669 // may be eliminated.
1670 storestore_worklist.append(n);
1671 #ifdef ASSERT
1672 } else if(n->is_AddP()) {
1673 // Collect address nodes. Use them during stage 3 below
1674 // to build initial connection graph field edges.
1675 addp_worklist.append(n);
1676 #endif
1677 }
1678 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1679 Node* m = n->fast_out(i); // Get user
1680 ideal_nodes.push(m);
1681 }
1682 }
1683
1684 if (non_escaped_worklist.length() == 0) {
1685 _collecting = false;
1686 return false; // Nothing to do.
1687 }
1688
1689 // Add final simple edges.
1690 while(delayed_worklist.size() > 0) {
1691 Node* n = delayed_worklist.pop();
1692 build_connection_graph(n, NULL, igvn);
1693 }
1694
1695 uint ptnodes_length = ptnodes_worklist.length();
1696
1697 #ifdef ASSERT
1698 if (VerifyConnectionGraph) {
1699 // Verify that no new simple edges could be created and all
1700 // local vars has edges.
1701 _verify = true;
1702 for (uint next = 0; next < ptnodes_length; ++next) {
1703 PointsToNode* ptn = ptnodes_worklist.at(next);
1704 build_connection_graph(ptn->ideal_node(), NULL, igvn);
1705 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
1706 ptn->dump();
1707 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
1708 }
1709 }
1710 _verify = false;
1711 }
1712 #endif
1713
1714 // 2. Finish Graph construction.
1715
1716 // Normally only 1-3 passes needed to build
1717 // Connection Graph depending on graph complexity.
1718 // Observed 8 passes in jvm2008 compiler.compiler.
1719 // Set limit to 20 to catch situation when something
1720 // did go wrong and recompile the method without EA.
1721 // Also limit build time to 30 sec (60 in debug VM).
1722
1723 #define CG_BUILD_ITER_LIMIT 20
1724
1725 #ifdef ASSERT
1726 #define CG_BUILD_TIME_LIMIT 60.0
1727 #else
1728 #define CG_BUILD_TIME_LIMIT 30.0
1729 #endif
1730
1731 int iterations = 0;
1732
1733 // Propagate GlobalEscape and ArgEscape escape states
1734 // and check that we still have non escaped objects.
1735 // The method pushs on _worklist Field nodes which reference phantom_object.
1736 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1737 _collecting = false;
1738 return false; // Nothing to do.
1739 }
1740
1741 // Propagate references to all JavaObject nodes.
1742 uint java_objects_length = java_objects_worklist.length();
1743
1744 elapsedTimer time;
1745 int new_edges = 1;
1746 while ((new_edges > 0) &&
1747 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1748 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1749 time.start();
1750 new_edges = 0;
1751 // Propagate references to phantom_object for nodes pushed on _worklist
1752 // by find_non_escaped_objects().
1753 new_edges += add_java_object_edges(phantom_obj, false);
1754 for (uint next = 0; next < java_objects_length; ++next) {
1755 JavaObjectNode* ptn = java_objects_worklist.at(next);
1756 new_edges += add_java_object_edges(ptn, true);
1757 }
1758 if (new_edges > 0) {
1759 // Update escape states on each iteration if graph was updated.
1760 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1761 _collecting = false;
1762 return false; // Nothing to do.
1763 }
1764 }
1765 time.stop();
1766 }
1767
1768 time.start();
1769 // Find fields which have unknown value.
1770 uint fields_length = oop_fields_worklist.length();
1771 for (uint next = 0; next < fields_length; next++) {
1772 FieldNode* field = oop_fields_worklist.at(next);
1773 if (field->edge_count() == 0) {
1774 new_edges += find_field_value(field);
1775 }
1776 }
1777 time.stop();
1778
1779 while ((new_edges > 0) &&
1780 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1781 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1782 time.start();
1783 new_edges = 0;
1784 // Propagate references to phantom_object for nodes pushed on _worklist
1785 // by previous code.
1786 new_edges += add_java_object_edges(phantom_obj, false);
1787 if (new_edges > 0) {
1788 // Update escape states on each iteration if graph was updated.
1789 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1790 _collecting = false;
1791 return false; // Nothing to do.
1792 }
1793 }
1794 time.stop();
1795 }
1796
1797 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1798 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1799 assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1800 time.seconds(), iterations, nodes_size(), ptnodes_length));
1801 // Possible infinite build_connection_graph loop,
1802 // bailout (no changes to ideal graph were made).
1803 _collecting = false;
1804 return false;
1805 }
1806
1807 #ifdef ASSERT
1808 if (Verbose && PrintEscapeAnalysis) {
1809 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1810 iterations, nodes_size(), ptnodes_length);
1811 }
1812 #endif
1813
1814 #undef CG_BUILD_ITER_LIMIT
1815 #undef CG_BUILD_TIME_LIMIT
1816
1817
1818 // 3. Find fields initialized by NULL for non escaped Allocations.
1819
1820 uint non_escaped_length = non_escaped_worklist.length();
1821 for (uint next = 0; next < non_escaped_length; next++) {
1822 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1823 PointsToNode::EscapeState es = ptn->escape_state();
1824 assert(es <= PointsToNode::ArgEscape, "sanity");
1825
1826 if (es == PointsToNode::NoEscape) {
1827 if (find_init_values(ptn, null_obj, igvn) > 0) {
1828 // Adding references to NULL object does not change escape states
1829 // since it does not escape. Also no fields are added to NULL object.
1830 add_java_object_edges(null_obj, false);
1831 }
1832 }
1833 Node* n = ptn->ideal_node();
1834 if (n->is_Allocate()) {
1835 // The object allocated by this Allocate node will never be
1836 // seen by an other thread. Mark it so that when it is
1837 // expanded no MemBarStoreStore is added.
1838 InitializeNode* ini = n->as_Allocate()->initialization();
1839 if (ini != NULL)
1840 ini->set_does_not_escape();
1841 }
1842 }
1843
1844 #ifdef ASSERT
1845 if (VerifyConnectionGraph) {
1846 uint addp_length = addp_worklist.length();
1847 for (uint next = 0; next < addp_length; ++next ) {
1848 Node* n = addp_worklist.at(next);
1849 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1850 if (field->is_oop()) {
1851 // Verify that field has all bases
1852 Node* base = get_addp_base(n);
1853 PointsToNode* ptn = ptnode_adr(base->_idx);
1854 if (ptn->is_JavaObject()) {
1855 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1856 } else {
1857 assert(ptn->is_LocalVar(), "sanity");
1858 uint count = ptn->edge_count();
1859 for (uint i = 0; i < count; i++) {
1860 PointsToNode* e = ptn->edge(i);
1861 if (e->is_JavaObject()) {
1862 assert(field->has_base(e->as_JavaObject()), "sanity");
1863 }
1864 }
1865 }
1866 // Verify that all fields have initializing values.
1867 if (field->edge_count() == 0) {
1868 field->dump();
1869 assert(field->edge_count() > 0, "sanity");
1870 }
1871 }
1872 }
1873 }
1874 #endif
1875
1876 // 4. Adjust scalar_replaceable state of nonescaping objects.
1877
1878 for (uint next = 0; next < non_escaped_length; next++) {
1879 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1880 if (ptn->escape_state() == PointsToNode::NoEscape &&
1881 ptn->scalar_replaceable()) {
1882 adjust_scalar_replaceable_state(ptn);
1883
1884 if (ptn->scalar_replaceable()) {
1885 // Push scalar replaceable allocations on alloc_worklist
1886 // for processing in split_unique_types().
1887 alloc_worklist.append(ptn->ideal_node());
1888 }
1889 }
1890 }
1891
1892 #ifdef ASSERT
1893 if (VerifyConnectionGraph) {
1894 // Verify that graph is complete - no new edges could be added.
1895 new_edges = 0;
1896 for (uint next = 0; next < java_objects_length; ++next) {
1897 JavaObjectNode* ptn = java_objects_worklist.at(next);
1898 new_edges += add_java_object_edges(ptn, true);
1899 }
1900 assert(new_edges == 0, "graph was not complete");
1901
1902 // Verify that escape state is final.
1903 uint length = non_escaped_worklist.length();
1904 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1905 assert((non_escaped_length == (uint)non_escaped_worklist.length()) &&
1906 (non_escaped_length == length) &&
1907 (_worklist.length() == 0), "escape state was not final");
1908 }
1909 #endif
1910
1911 _collecting = false;
1912 assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1913
1914 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
1915 null_obj->edge_count() == 0 &&
1916 !null_obj->arraycopy_src() &&
1917 !null_obj->arraycopy_dst(), "sanity");
1918
1919 } // TracePhase t3("buildConnectionGraph")
1920
1921 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
1922
1923 if (EliminateLocks && has_non_escaping_obj) {
1924 // Mark locks before changing ideal graph.
1925 int cnt = C->macro_count();
1926 for( int i=0; i < cnt; i++ ) {
1927 Node *n = C->macro_node(i);
1928 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1929 AbstractLockNode* alock = n->as_AbstractLock();
1930 if (!alock->is_non_esc_obj()) {
1931 if (not_global_escape(alock->obj_node())) {
1932 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1933 // The lock could be marked eliminated by lock coarsening
1934 // code during first IGVN before EA. Replace coarsened flag
1935 // to eliminate all associated locks/unlocks.
1936 alock->set_non_esc_obj();
1937 }
1938 }
1939 }
1940 }
1941 }
1942
1943 if (OptimizePtrCompare && has_non_escaping_obj) {
1944 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1945 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1946 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1947 // Optimize objects compare.
1948 while (ptr_cmp_worklist.length() != 0) {
1949 Node *n = ptr_cmp_worklist.pop();
1950 Node *res = optimize_ptr_compare(n);
1951 if (res != NULL) {
1952 #ifndef PRODUCT
1953 if (PrintOptimizePtrCompare) {
1954 tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ"));
1955 if (Verbose) {
1956 n->dump(1);
1957 }
1958 }
1959 #endif
1960 _igvn->replace_node(n, res);
1961 }
1962 }
1963 // cleanup
1964 if (_pcmp_neq->outcnt() == 0)
1965 igvn->hash_delete(_pcmp_neq);
1966 if (_pcmp_eq->outcnt() == 0)
1967 igvn->hash_delete(_pcmp_eq);
1968 }
1969
1970 // For MemBarStoreStore nodes added in library_call.cpp, check
1971 // escape status of associated AllocateNode and optimize out
1972 // MemBarStoreStore node if the allocated object never escapes.
1973 while (storestore_worklist.length() != 0) {
1974 Node *n = storestore_worklist.pop();
1975 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1976 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1977 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1978 PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
1979 if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
1980 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1981 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1982 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1983
1984 _igvn->register_new_node_with_optimizer(mb);
1985 _igvn->replace_node(storestore, mb);
1986 }
1987 }
1988
1989 #ifndef PRODUCT
1990 if (PrintEscapeAnalysis) {
1991 dump(ptnodes_worklist); // Dump ConnectionGraph
1992 }
1993 #endif
1994
1995 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
1996 #ifdef ASSERT
1997 if (VerifyConnectionGraph) {
1998 uint alloc_length = alloc_worklist.length();
1999 for (uint next = 0; next < alloc_length; ++next) {
2000 Node* n = alloc_worklist.at(next);
2001 PointsToNode* ptn = ptnode_adr(n->_idx);
2002 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
2003 }
2004 }
2005 #endif
2006
2007 if (has_scalar_replaceable_candidates &&
2008 C->AliasLevel() >= 3 && EliminateAllocations) {
2009
2010 // Now use the escape information to create unique types for
2011 // scalar replaceable objects.
2012 split_unique_types(alloc_worklist);
2013
2014 if (C->failing()) return false;
2015
2016 C->print_method("After Escape Analysis", 2);
2017
2018 #ifdef ASSERT
2019 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
2020 tty->print("=== No allocations eliminated for ");
2021 C->method()->print_short_name();
2022 if(!EliminateAllocations) {
2023 tty->print(" since EliminateAllocations is off ===");
2024 } else if(!has_scalar_replaceable_candidates) {
2025 tty->print(" since there are no scalar replaceable candidates ===");
2026 } else if(C->AliasLevel() < 3) {
2027 tty->print(" since AliasLevel < 3 ===");
2028 }
2029 tty->cr();
2030 #endif
2031 }
2032 return has_non_escaping_obj;
2033 }
2034
2035 // Find fields which have unknown value.
2036 int ConnectionGraph::find_field_value(FieldNode* field) {
2037 // Escaped fields should have init value already.
2038 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
2039
2040 int new_edges = 0;
2041
2042 uint bcnt = field->base_count();
2043 for (uint i = 0; i < bcnt; i++) {
2044 PointsToNode* base = field->base(i);
2045 if (base->is_JavaObject()) {
2046 // Skip Allocate's fields which will be processed later.
2047 if (base->ideal_node()->is_Allocate())
2048 return 0;
2049 assert(base == null_obj, "only NULL ptr base expected here");
2050 }
2051 }
2052 if (add_edge(field, phantom_obj)) {
2053 // New edge was added
2054 new_edges++;
2055 add_field_uses_to_worklist(field);
2056 }
2057 return new_edges;
2058 }
2059
2060 // Find fields initializing values for allocations.
2061 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
2062 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
2063
2064 int new_edges = 0;
2065
2066 Node* alloc = pta->ideal_node();
2067
2068 if (init_val == phantom_obj) {
2069 // Do nothing for Allocate nodes since its fields values are "known".
2070 if (alloc->is_Allocate())
2071 return 0;
2072
2073 assert(alloc->as_CallStaticJava(), "sanity");
2074 #ifdef ASSERT
2075 if (alloc->as_CallStaticJava()->method() == NULL) {
2076 const char* name = alloc->as_CallStaticJava()->_name;
2077 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
2078 }
2079 #endif
2080
2081 // Non-escaped allocation returned from Java or runtime call have
2082 // unknown values in fields.
2083 uint cnt = pta->edge_count();
2084 for (uint i = 0; i < cnt; i++) {
2085 PointsToNode* ptn = pta->edge(i);
2086 if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
2087 if (add_edge(ptn, phantom_obj)) {
2088 // New edge was added
2089 new_edges++;
2090 add_field_uses_to_worklist(ptn->as_Field());
2091 }
2092 }
2093 }
2094 return new_edges;
2095 }
2096
2097 assert(init_val == null_obj, "sanity");
2098 // Do nothing for Call nodes since its fields values are unknown.
2099 if (!alloc->is_Allocate())
2100 return 0;
2101
2102 InitializeNode* ini = alloc->as_Allocate()->initialization();
2103
2104 Compile* C = _compile;
2105 bool visited_bottom_offset = false;
2106 GrowableArray<int> offsets_worklist;
2107
2108 // Check if a oop field's initializing value is recorded and add
2109 // a corresponding NULL if field's value if it is not recorded.
2110 // Connection Graph does not record a default initialization by NULL
2111 // captured by Initialize node.
2112 //
2113 uint ae_cnt = pta->edge_count();
2114 for (uint ei = 0; ei < ae_cnt; ei++) {
2115
2116 PointsToNode* ptn = pta->edge(ei); // Field (AddP)
2117 if (!ptn->is_Field() || !ptn->as_Field()->is_oop())
2118 continue; // Not oop field
2119
2120 int offset = ptn->as_Field()->offset();
2121 if (offset == Type::OffsetBot) {
2122 if (!visited_bottom_offset) {
2123 // OffsetBot is used to reference array's element,
2124 // always add reference to NULL to all Field nodes since we don't
2125 // known which element is referenced.
2126 if (add_edge(ptn, null_obj)) {
2127 // New edge was added
2128 new_edges++;
2129 add_field_uses_to_worklist(ptn->as_Field());
2130 visited_bottom_offset = true;
2131 }
2132 }
2133 } else {
2134 // Check only oop fields.
2135 const Type* adr_type = ptn->ideal_node()->as_AddP()->bottom_type();
2136 if (adr_type->isa_rawptr()) {
2137 #ifdef ASSERT
2138 // Raw pointers are used for initializing stores so skip it
2139 // since it should be recorded already
2140 Node* base = get_addp_base(ptn->ideal_node());
2141 assert(adr_type->isa_rawptr() && base->is_Proj() &&
2142 (base->in(0) == alloc),"unexpected pointer type");
2143 #endif
2144 continue;
2145 }
2146 if (!offsets_worklist.contains(offset)) {
2147 offsets_worklist.append(offset);
2148 Node* value = NULL;
2149 if (ini != NULL) {
2150 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
2151 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
2152 if (store != NULL && store->is_Store()) {
2153 value = store->in(MemNode::ValueIn);
2154 } else {
2155 // There could be initializing stores which follow allocation.
2156 // For example, a volatile field store is not collected
2157 // by Initialize node.
2158 //
2159 // Need to check for dependent loads to separate such stores from
2160 // stores which follow loads. For now, add initial value NULL so
2161 // that compare pointers optimization works correctly.
2162 }
2163 }
2164 if (value == NULL) {
2165 // A field's initializing value was not recorded. Add NULL.
2166 if (add_edge(ptn, null_obj)) {
2167 // New edge was added
2168 new_edges++;
2169 add_field_uses_to_worklist(ptn->as_Field());
2170 }
2171 }
2172 }
2173 }
2174 }
2175 return new_edges;
2176 }
2177
2178 // Adjust scalar_replaceable state after Connection Graph is built.
2179 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
2180 // Search for non escaped objects which are not scalar replaceable
2181 // and mark them to propagate the state to referenced objects.
2182
2183 // 1. An object is not scalar replaceable if the field into which it is
2184 // stored has unknown offset (stored into unknown element of an array).
2185 //
2186 uint count = jobj->use_count();
2187 for (uint i = 0; i < count; i++) {
2188 PointsToNode* use = jobj->use(i);
2189 assert(!use->is_Arraycopy(), "sanity");
2190 if (use->is_Field()) {
2191 FieldNode* field = use->as_Field();
2192 assert(field->is_oop() && field->scalar_replaceable() &&
2193 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
2194 if (field->offset() == Type::OffsetBot) {
2195 jobj->set_scalar_replaceable(false);
2196 return;
2197 }
2198 }
2199 assert(use->is_Field() || use->is_LocalVar(), "sanity");
2200
2201 // 2. An object is not scalar replaceable if it is merged with other objects.
2202 uint e_count = use->edge_count();
2203 for (uint j = 0; j < e_count; j++) {
2204 PointsToNode* ptn = use->edge(j);
2205 if (ptn->is_JavaObject() && ptn != jobj) {
2206 // Mark all objects.
2207 jobj->set_scalar_replaceable(false);
2208 ptn->set_scalar_replaceable(false);
2209 }
2210 }
2211 if (!jobj->scalar_replaceable()) {
2212 return;
2213 }
2214 }
2215
2216 count = jobj->edge_count();
2217 for (uint i = 0; i < count; i++) {
2218 // Non escaped object should points only to fields.
2219 FieldNode* field = jobj->edge(i)->as_Field();
2220 int offset = field->as_Field()->offset();
2221
2222 // 3. An object is not scalar replaceable if it has a field with unknown
2223 // offset (array's element is accessed in loop).
2224 if (offset == Type::OffsetBot) {
2225 jobj->set_scalar_replaceable(false);
2226 return;
2227 }
2228
2229 // 4. Currently an object is not scalar replaceable if a LoadStore node
2230 // access its field since the field value is unknown after it.
2231 //
2232 Node* n = field->ideal_node();
2233 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2234 if (n->fast_out(i)->is_LoadStore()) {
2235 jobj->set_scalar_replaceable(false);
2236 return;
2237 }
2238 }
2239
2240 // 5. Or the address may point to more then one object. This may produce
2241 // the false positive result (set not scalar replaceable)
2242 // since the flow-insensitive escape analysis can't separate
2243 // the case when stores overwrite the field's value from the case
2244 // when stores happened on different control branches.
2245 //
2246 // Note: it will disable scalar replacement in some cases:
2247 //
2248 // Point p[] = new Point[1];
2249 // p[0] = new Point(); // Will be not scalar replaced
2250 //
2251 // but it will save us from incorrect optimizations in next cases:
2252 //
2253 // Point p[] = new Point[1];
2254 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
2255 //
2256 uint bcnt = field->base_count();
2257 if (bcnt > 1) {
2258 for (uint i = 0; i < bcnt; i++) {
2259 PointsToNode* base = field->base(i);
2260 // Don't take into account LocalVar nodes which
2261 // may point to only one object which should be also
2262 // this field's base by now.
2263 if (base->is_JavaObject() && base != jobj) {
2264 // Mark all bases.
2265 jobj->set_scalar_replaceable(false);
2266 base->set_scalar_replaceable(false);
2267 }
2268 }
2269 }
2270 }
2271 }
2272
2273
2274 // Propagate GlobalEscape and ArgEscape escape states to all nodes
2275 // and check that we still have non escaped java objects.
2276 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
2277 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
2278 GrowableArray<PointsToNode*> escape_worklist;
2279
2280 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
2281 uint ptnodes_length = ptnodes_worklist.length();
2282 for (uint next = 0; next < ptnodes_length; ++next) {
2283 PointsToNode* ptn = ptnodes_worklist.at(next);
2284 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
2285 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
2286 escape_worklist.push(ptn);
2287 }
2288 }
2289 // Set escape states to referenced nodes (edges list).
2290 while (escape_worklist.length() > 0) {
2291 PointsToNode* ptn = escape_worklist.pop();
2292 PointsToNode::EscapeState es = ptn->escape_state();
2293 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
2294 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
2295 es >= PointsToNode::ArgEscape) {
2296 // GlobalEscape or ArgEscape state of field means it has unknown value.
2297 if (add_edge(ptn, phantom_obj)) {
2298 // New edge was added
2299 add_field_uses_to_worklist(ptn->as_Field());
2300 }
2301 }
2302 uint cnt = ptn->edge_count();
2303 for (uint i = 0; i < cnt; i++) {
2304 PointsToNode* e = ptn->edge(i);
2305 if (e->is_Arraycopy()) {
2306 assert(ptn->arraycopy_dst(), "sanity");
2307 // Propagate only fields escape state through arraycopy edge.
2308 if (e->fields_escape_state() < field_es) {
2309 set_fields_escape_state(e, field_es);
2310 escape_worklist.push(e);
2311 }
2312 } else if (es >= field_es) {
2313 // fields_escape_state is also set to 'es' if it is less than 'es'.
2314 if (e->escape_state() < es) {
2315 set_escape_state(e, es);
2316 escape_worklist.push(e);
2317 }
2318 } else {
2319 // Propagate field escape state.
2320 bool es_changed = false;
2321 if (e->fields_escape_state() < field_es) {
2322 set_fields_escape_state(e, field_es);
2323 es_changed = true;
2324 }
2325 if ((e->escape_state() < field_es) &&
2326 e->is_Field() && ptn->is_JavaObject() &&
2327 e->as_Field()->is_oop()) {
2328 // Change escape state of referenced fileds.
2329 set_escape_state(e, field_es);
2330 es_changed = true;;
2331 } else if (e->escape_state() < es) {
2332 set_escape_state(e, es);
2333 es_changed = true;;
2334 }
2335 if (es_changed) {
2336 escape_worklist.push(e);
2337 }
2338 }
2339 }
2340 }
2341
2342 // Remove escaped objects from non_escaped list.
2343 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
2344 JavaObjectNode* ptn = non_escaped_worklist.at(next);
2345 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
2346 non_escaped_worklist.delete_at(next);
2347 }
2348 if (ptn->escape_state() == PointsToNode::NoEscape) {
2349 // Find fields in non-escaped allocations which have unknown value.
2350 find_init_values(ptn, phantom_obj, NULL);
2351 }
2352 }
2353
2354 return (non_escaped_worklist.length() > 0);
2355 }
2356
2357 // Optimize objects compare.
2358 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
2359 assert(OptimizePtrCompare, "sanity");
2360
2361 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
2362 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
2363 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
2364 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
2365
2366 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
2367 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
2368
2369 // Check simple cases first.
2370 if (jobj1 != NULL) {
2371 if (jobj1->escape_state() == PointsToNode::NoEscape) {
2372 if (jobj1 == jobj2) {
2373 // Comparing the same not escaping object.
2374 return _pcmp_eq;
2375 }
2376 Node* obj = jobj1->ideal_node();
2377 // Comparing not escaping allocation.
2378 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2379 !ptn2->points_to(jobj1)) {
2380 return _pcmp_neq; // This includes nullness check.
2381 }
2382 }
2383 }
2384 if (jobj2 != NULL) {
2385 if (jobj2->escape_state() == PointsToNode::NoEscape) {
2386 Node* obj = jobj2->ideal_node();
2387 // Comparing not escaping allocation.
2388 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2389 !ptn1->points_to(jobj2)) {
2390 return _pcmp_neq; // This includes nullness check.
2391 }
2392 }
2393 }
2394
2395 if (jobj1 != NULL && jobj1 != phantom_obj &&
2396 jobj2 != NULL && jobj2 != phantom_obj &&
2397 jobj1->ideal_node()->is_Con() &&
2398 jobj2->ideal_node()->is_Con()) {
2399 // Klass or String constants compare. Need to be careful with
2400 // compressed pointers - compare types of ConN and ConP instead of nodes.
2401 const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr();
2402 const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr();
2403 assert(t1 != NULL && t2 != NULL, "sanity");
2404 if (t1->make_ptr() == t2->make_ptr()) {
2405 return _pcmp_eq;
2406 } else {
2407 return _pcmp_neq;
2408 }
2409 }
2410
2411 if (ptn1->meet(ptn2)) {
2412 return NULL; // Sets are not disjoint
2413 }
2414
2415 // Sets are disjoint.
2416 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
2417 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
2418 bool set1_has_null_ptr = ptn1->points_to(null_obj);
2419 bool set2_has_null_ptr = ptn2->points_to(null_obj);
2420
2421 if (set1_has_unknown_ptr && set2_has_null_ptr ||
2422 set2_has_unknown_ptr && set1_has_null_ptr) {
2423 // Check nullness of unknown object.
2424 return NULL;
2425 }
2426
2427 // Disjointness by itself is not sufficient since
2428 // alias analysis is not complete for escaped objects.
2429 // Disjoint sets are definitely unrelated only when
2430 // at least one set has only not escaping allocations.
2431 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2432 if (ptn1->not_escaped_allocation()) {
2433 return _pcmp_neq;
2434 }
2435 }
2436 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2437 if (ptn2->not_escaped_allocation()) {
2438 return _pcmp_neq;
2439 }
2440 }
2441 return NULL;
2442 }
2443
2444 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
2445 bool is_arraycopy = false;
2446 switch (call->Opcode()) {
2447 #ifdef ASSERT
2448 case Op_Allocate:
2449 case Op_AllocateArray:
2450 case Op_Lock:
2451 case Op_Unlock:
2452 assert(false, "should be done already");
2453 break;
2454 #endif
2455 case Op_CallLeafNoFP:
2456 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
2457 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
2458 // fall through
2459 case Op_CallLeaf:
2460 {
2461 // Stub calls, objects do not escape but they are not scale replaceable.
2462 // Adjust escape state for outgoing arguments.
2463 const TypeTuple * d = call->tf()->domain();
2464 bool src_has_oops = false;
2465 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2466 const Type* at = d->field_at(i);
2467 Node *arg = call->in(i);
2468 const Type *aat = phase->type(arg);
2469 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
2470 continue;
2471 if (arg->is_AddP()) {
2472 //
2473 // The inline_native_clone() case when the arraycopy stub is called
2474 // after the allocation before Initialize and CheckCastPP nodes.
2475 // Or normal arraycopy for object arrays case.
2476 //
2477 // Set AddP's base (Allocate) as not scalar replaceable since
2478 // pointer to the base (with offset) is passed as argument.
2479 //
2480 arg = get_addp_base(arg);
2481 }
2482 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2483 assert(arg_ptn != NULL, "should be registered");
2484 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
2485 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
2486 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2487 aat->isa_ptr() != NULL, "expecting an Ptr");
2488 bool arg_has_oops = aat->isa_oopptr() &&
2489 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
2490 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
2491 if (i == TypeFunc::Parms) {
2492 src_has_oops = arg_has_oops;
2493 }
2494 //
2495 // src or dst could be j.l.Object when other is basic type array:
2496 //
2497 // arraycopy(char[],0,Object*,0,size);
2498 // arraycopy(Object*,0,char[],0,size);
2499 //
2500 // Don't add edges in such cases.
2501 //
2502 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
2503 arg_has_oops && (i > TypeFunc::Parms);
2504 #ifdef ASSERT
2505 if (!(is_arraycopy ||
2506 call->as_CallLeaf()->_name != NULL &&
2507 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
2508 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
2509 ) {
2510 call->dump();
2511 assert(false, "EA: unexpected CallLeaf");
2512 }
2513 #endif
2514 // Always process arraycopy's destination object since
2515 // we need to add all possible edges to references in
2516 // source object.
2517 if (arg_esc >= PointsToNode::ArgEscape &&
2518 !arg_is_arraycopy_dest) {
2519 continue;
2520 }
2521 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
2522 if (arg_is_arraycopy_dest) {
2523 Node* src = call->in(TypeFunc::Parms);
2524 if (src->is_AddP()) {
2525 src = get_addp_base(src);
2526 }
2527 PointsToNode* src_ptn = ptnode_adr(src->_idx);
2528 assert(src_ptn != NULL, "should be registered");
2529 if (arg_ptn != src_ptn) {
2530 // Special arraycopy edge:
2531 // A destination object's field can't have the source object
2532 // as base since objects escape states are not related.
2533 // Only escape state of destination object's fields affects
2534 // escape state of fields in source object.
2535 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
2536 }
2537 }
2538 }
2539 }
2540 break;
2541 }
2542
2543 case Op_CallStaticJava:
2544 // For a static call, we know exactly what method is being called.
2545 // Use bytecode estimator to record the call's escape affects
2546 {
2547 #ifdef ASSERT
2548 const char* name = call->as_CallStaticJava()->_name;
2549 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
2550 #endif
2551
2552 ciMethod* meth = call->as_CallJava()->method();
2553 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
2554 // fall-through if not a Java method or no analyzer information
2555 if (call_analyzer != NULL) {
2556 PointsToNode* call_ptn = ptnode_adr(call->_idx);
2557 const TypeTuple* d = call->tf()->domain();
2558 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2559 const Type* at = d->field_at(i);
2560 int k = i - TypeFunc::Parms;
2561 Node* arg = call->in(i);
2562 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2563 if (at->isa_ptr() != NULL &&
2564 call_analyzer->is_arg_returned(k)) {
2565 // The call returns arguments.
2566 if (call_ptn != NULL) { // Is call's result used?
2567 assert(call_ptn->is_LocalVar(), "node should be registered");
2568 assert(arg_ptn != NULL, "node should be registered");
2569 add_edge(call_ptn, arg_ptn);
2570 }
2571 }
2572 if (at->isa_oopptr() != NULL &&
2573 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
2574 bool global_escapes = false;
2575 bool fields_escapes = false;
2576 if (!call_analyzer->is_arg_stack(k)) {
2577 // The argument global escapes
2578 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
2579 } else {
2580 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
2581 if (!call_analyzer->is_arg_local(k)) {
2582 // The argument itself doesn't escape, but any fields might
2583 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
2584 }
2585 }
2586 }
2587 }
2588 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
2589 // The call returns arguments.
2590 assert(call_ptn->edge_count() > 0, "sanity");
2591 if (!call_analyzer->is_return_local()) {
2592 // Returns also unknown object.
2593 add_edge(call_ptn, phantom_obj);
2594 }
2595 }
2596 break;
2597 }
2598 }
2599
2600 default:
2601 // Fall-through here if not a Java method or no analyzer information
2602 // or some other type of call, assume the worst case: all arguments
2603 // globally escape.
2604 {
2605 const TypeTuple* d = call->tf()->domain();
2606 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2607 const Type* at = d->field_at(i);
2608 if (at->isa_oopptr() != NULL) {
2609 Node* arg = call->in(i);
2610 if (arg->is_AddP()) {
2611 arg = get_addp_base(arg);
2612 }
2613 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
2614 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
2615 }
2616 }
2617 }
2618 }
2619 }
2620
2621 void ConnectionGraph::add_call_node(CallNode* call) {
2622 assert(call->returns_pointer(), "only for call which returns pointer");
2623 uint call_idx = call->_idx;
2624 if (call->is_Allocate()) {
2625 Node* k = call->in(AllocateNode::KlassNode);
2626 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
2627 assert(kt != NULL, "TypeKlassPtr required.");
2628 ciKlass* cik = kt->klass();
2629
2630 PointsToNode::EscapeState es = PointsToNode::NoEscape;
2631 bool scalar_replaceable = true;
2632 if (call->is_AllocateArray()) {
2633 if (!cik->is_array_klass()) { // StressReflectiveCode
2634 es = PointsToNode::GlobalEscape;
2635 } else {
2636 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2637 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2638 // Not scalar replaceable if the length is not constant or too big.
2639 scalar_replaceable = false;
2640 }
2641 }
2642 } else { // Allocate instance
2643 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2644 !cik->is_instance_klass() || // StressReflectiveCode
2645 cik->as_instance_klass()->has_finalizer()) {
2646 es = PointsToNode::GlobalEscape;
2647 }
2648 }
2649 add_java_object(call, es);
2650 PointsToNode* ptn = ptnode_adr(call_idx);
2651 if (!scalar_replaceable && ptn->scalar_replaceable())
2652 ptn->set_scalar_replaceable(false);
2653
2654 } else if (call->is_CallStaticJava()) {
2655 // Call nodes could be different types:
2656 //
2657 // 1. CallDynamicJavaNode (what happened during call is unknown):
2658 //
2659 // - mapped to GlobalEscape JavaObject node if oop is returned;
2660 //
2661 // - all oop arguments are escaping globally;
2662 //
2663 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
2664 //
2665 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
2666 //
2667 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
2668 // - mapped to NoEscape JavaObject node if non escaped object allocated
2669 // during call is returned;
2670 // - mapped to ArgEscape LocalVar node pointed to object arguments
2671 // which are returned and does not escape during call;
2672 //
2673 // - oop arguments escaping status is defined by bytecode analysis;
2674 //
2675
2676 // For a static call, we know exactly what method is being called.
2677 // Use bytecode estimator to record whether the call's return value escapes.
2678 ciMethod* meth = call->as_CallJava()->method();
2679 if (meth == NULL) {
2680 const char* name = call->as_CallStaticJava()->_name;
2681 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
2682 // Returns a newly allocated unescaped object.
2683 add_java_object(call, PointsToNode::NoEscape);
2684 ptnode_adr(call_idx)->set_scalar_replaceable(false);
2685 } else {
2686 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2687 call_analyzer->copy_dependencies(_compile->dependencies());
2688 if (call_analyzer->is_return_allocated()) {
2689 // Returns a newly allocated unescaped object, simply
2690 // update dependency information.
2691 // Mark it as NoEscape so that objects referenced by
2692 // it's fields will be marked as NoEscape at least.
2693 add_java_object(call, PointsToNode::NoEscape);
2694 ptnode_adr(call_idx)->set_scalar_replaceable(false);
2695 } else {
2696 // Determine whether any arguments are returned.
2697 const TypeTuple* d = call->tf()->domain();
2698 bool ret_arg = false;
2699 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2700 if (d->field_at(i)->isa_ptr() != NULL &&
2701 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2702 ret_arg = true;
2703 break;
2704 }
2705 }
2706 if (ret_arg) {
2707 add_local_var(call, PointsToNode::ArgEscape);
2708 } else {
2709 // Returns unknown object.
2710 map_ideal_node(call, phantom_obj);
2711 }
2712 }
2713 }
2714 } else {
2715 // An other type of call, assume the worst case:
2716 // returned value is unknown and globally escapes.
2717 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
2718 map_ideal_node(call, phantom_obj);
2719 }
2720 }
2721
2722 // Populate Connection Graph with PointsTo nodes and create simple
2723 // connection graph edges.
2724 void ConnectionGraph::build_connection_graph(Node *n,
2725 Unique_Node_List *delayed_worklist,
2726 PhaseTransform *phase) {
2727 // During first iteration create PointsTo nodes and simple edges.
2728 // During second iteration create the rest of edges.
2729 bool first_iteration = (delayed_worklist != NULL);
2730
2731 uint n_idx = n->_idx;
2732 PointsToNode* n_ptn = ptnode_adr(n_idx);
2733 if (first_iteration && n_ptn != NULL)
2734 return; // No need to redefine PointsTo node during first iteration.
2735
2736 #ifdef ASSERT
2737 if (_verify && n_ptn->is_JavaObject())
2738 return; // Following code for JavaObject does not change graph.
2739 #endif
2740
2741 if (n->is_Call()) {
2742 if (!first_iteration) {
2743 process_call_arguments(n->as_Call(), phase);
2744 return;
2745 }
2746 // Arguments to allocation and locking don't escape.
2747 if (n->is_AbstractLock()) {
2748 // Put Lock and Unlock nodes on IGVN worklist to process them during
2749 // first IGVN optimization when escape information is still available.
2750 record_for_optimizer(n);
2751 } else if (n->is_Allocate()) {
2752 add_call_node(n->as_Call());
2753 record_for_optimizer(n);
2754 } else {
2755 if (n->is_CallStaticJava()) {
2756 const char* name = n->as_CallStaticJava()->_name;
2757 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
2758 return; // Skip uncommon traps
2759 }
2760 // Don't mark as processed since call's arguments have to be processed.
2761 delayed_worklist->push(n);
2762
2763 // Check if a call returns an object.
2764 if (n->as_Call()->returns_pointer() &&
2765 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2766 add_call_node(n->as_Call());
2767 }
2768 }
2769 return;
2770 }
2771
2772 // Put this check here to process call arguments since some call nodes
2773 // point to phantom_obj.
2774 if (n_ptn == phantom_obj || n_ptn == null_obj)
2775 return; // Skip predefined nodes.
2776
2777 assert(first_iteration || n->is_Store() || n->is_LoadStore() ||
2778 n_ptn != NULL && n_ptn->ideal_node() != NULL,
2779 "node should be registered during second iteration");
2780
2781 int opcode = n->Opcode();
2782 switch (opcode) {
2783 case Op_AddP:
2784 {
2785 Node* base = get_addp_base(n);
2786 PointsToNode* ptn = ptnode_adr(base->_idx);
2787 if (first_iteration) {
2788 // Field node is created for all field types. It will help in
2789 // split_unique_types(). Note, there will be no uses of non oop fields
2790 // in Connection Graph.
2791 int offset = address_offset(n, phase);
2792 add_field(n, PointsToNode::NoEscape, offset);
2793 if (ptn == NULL) {
2794 delayed_worklist->push(n);
2795 return; // Process it later.
2796 }
2797 n_ptn = ptnode_adr(n_idx);
2798 } else {
2799 assert(ptn != NULL, "node should be registered");
2800 }
2801 add_base(n_ptn->as_Field(), ptn);
2802 break;
2803 }
2804 case Op_CastX2P:
2805 {
2806 if (first_iteration) {
2807 // "Unsafe" memory access to unknown object.
2808 map_ideal_node(n, phantom_obj);
2809 } else {
2810 assert(false, "Op_CastX2P");
2811 }
2812 break;
2813 }
2814 case Op_CastPP:
2815 case Op_CheckCastPP:
2816 case Op_EncodeP:
2817 case Op_DecodeN:
2818 {
2819 add_local_var_and_edge(n, PointsToNode::NoEscape,
2820 n->in(1), delayed_worklist);
2821 break;
2822 }
2823 case Op_CMoveP:
2824 {
2825 if (first_iteration) {
2826 add_local_var(n, PointsToNode::NoEscape);
2827 // Do not add edges during first iteration because some could be
2828 // not defined yet.
2829 delayed_worklist->push(n);
2830 return; // Process it later.
2831 } else {
2832 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
2833 Node* in = n->in(i);
2834 if (in == NULL)
2835 continue; // ignore NULL
2836 Node* uncast_in = in->uncast();
2837 if (uncast_in->is_top() || uncast_in == n)
2838 continue; // ignore top or inputs which go back this node
2839
2840 PointsToNode* ptn = ptnode_adr(in->_idx);
2841 assert(ptn != NULL, "node should be registered");
2842 add_edge(n_ptn, ptn);
2843 }
2844 }
2845 break;
2846 }
2847 case Op_ConP:
2848 case Op_ConN:
2849 {
2850 // assume all oop constants globally escape except for null
2851 if (first_iteration) {
2852 PointsToNode::EscapeState es;
2853 if (phase->type(n) == TypePtr::NULL_PTR ||
2854 phase->type(n) == TypeNarrowOop::NULL_PTR) {
2855 es = PointsToNode::NoEscape;
2856 } else {
2857 es = PointsToNode::GlobalEscape;
2858 }
2859 add_java_object(n, es);
2860 } else {
2861 assert(false, "Op_ConP");
2862 }
2863 break;
2864 }
2865 case Op_CreateEx:
2866 {
2867 if (first_iteration) {
2868 // assume that all exception objects globally escape
2869 add_java_object(n, PointsToNode::GlobalEscape);
2870 } else {
2871 assert(false, "Op_CreateEx");
2872 }
2873 break;
2874 }
2875 case Op_LoadKlass:
2876 case Op_LoadNKlass:
2877 {
2878 if (first_iteration) {
2879 // Unknown class is loaded
2880 map_ideal_node(n, phantom_obj);
2881 } else {
2882 assert(false, "Op_LoadKlass");
2883 }
2884 break;
2885 }
2886 case Op_LoadP:
2887 case Op_LoadN:
2888 case Op_LoadPLocked:
2889 {
2890 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2891 // ThreadLocal has RawPrt type.
2892 const Type* t = phase->type(n);
2893 if (t->make_ptr() != NULL) {
2894 Node* adr = n->in(MemNode::Address);
2895 if (!adr->is_AddP()) {
2896 assert(phase->type(adr)->isa_rawptr(), "sanity");
2897 } else {
2898 assert((ptnode_adr(adr->_idx) == NULL ||
2899 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
2900 }
2901 add_local_var_and_edge(n, PointsToNode::NoEscape,
2902 adr, delayed_worklist);
2903 #ifdef ASSERT
2904 } else if (!first_iteration) {
2905 n->dump(1);
2906 assert(false, "Op_LoadP");
2907 #endif
2908 }
2909 break;
2910 }
2911 case Op_Parm:
2912 {
2913 if (first_iteration) {
2914 // We have to assume all input parameters globally escape
2915 map_ideal_node(n, phantom_obj);
2916 } else {
2917 assert(false, "Op_Parm");
2918 }
2919 break;
2920 }
2921 case Op_PartialSubtypeCheck:
2922 {
2923 if (first_iteration) {
2924 // Produces Null or notNull and is used in only in CmpP so
2925 // phantom_obj could be used.
2926 map_ideal_node(n, phantom_obj); // Result is unknown
2927 } else {
2928 // Arguments are klasses which globally escape so do not need
2929 // to point to them.
2930 assert(false, "Op_PartialSubtypeCheck");
2931 }
2932 break;
2933 }
2934 case Op_Phi:
2935 {
2936 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2937 // ThreadLocal has RawPrt type.
2938 const Type* t = n->as_Phi()->type();
2939 if (t->make_ptr() != NULL) {
2940 if (first_iteration) {
2941 add_local_var(n, PointsToNode::NoEscape);
2942 // Do not add edges during first iteration because some could be
2943 // not defined yet.
2944 delayed_worklist->push(n);
2945 return; // Process it later.
2946 } else {
2947 for (uint i = 1; i < n->req(); i++) {
2948 Node* in = n->in(i);
2949 if (in == NULL)
2950 continue; // ignore NULL
2951 Node* uncast_in = in->uncast();
2952 if (uncast_in->is_top() || uncast_in == n)
2953 continue; // ignore top or inputs which go back this node
2954
2955 PointsToNode* ptn = ptnode_adr(in->_idx);
2956 assert(ptn != NULL, "node should be registered");
2957 add_edge(n_ptn, ptn);
2958 }
2959 }
2960 #ifdef ASSERT
2961 } else if (!first_iteration) {
2962 n->dump(1);
2963 assert(false, "Op_Phi");
2964 #endif
2965 }
2966 break;
2967 }
2968 case Op_Proj:
2969 {
2970 // we are only interested in the oop result projection from a call
2971 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
2972 n->in(0)->as_Call()->returns_pointer()) {
2973 add_local_var_and_edge(n, PointsToNode::NoEscape,
2974 n->in(0), delayed_worklist);
2975 #ifdef ASSERT
2976 } else if (!first_iteration) {
2977 n->dump(1);
2978 assert(false, "Op_Proj");
2979 #endif
2980 }
2981 break;
2982 }
2983 case Op_Rethrow: // Exception object escapes
2984 case Op_Return:
2985 {
2986 if (n->req() > TypeFunc::Parms &&
2987 phase->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
2988 // Treat Return value as LocalVar with GlobalEscape escape state.
2989 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
2990 n->in(TypeFunc::Parms), delayed_worklist);
2991 #ifdef ASSERT
2992 } else if (!first_iteration) {
2993 assert(false, "Op_Return");
2994 #endif
2995 }
2996 break;
2997 }
2998 case Op_StoreP:
2999 case Op_StoreN:
3000 case Op_StorePConditional:
3001 case Op_CompareAndSwapP:
3002 case Op_CompareAndSwapN:
3003 {
3004 Node* adr = n->in(MemNode::Address);
3005 const Type *adr_type = phase->type(adr);
3006 adr_type = adr_type->make_ptr();
3007 if (adr_type->isa_oopptr() ||
3008 (opcode == Op_StoreP || opcode == Op_StoreN) &&
3009 (adr_type == TypeRawPtr::NOTNULL &&
3010 adr->in(AddPNode::Address)->is_Proj() &&
3011 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
3012 #ifdef ASSERT
3013 assert(adr->is_AddP(), "expecting an AddP");
3014 if (adr_type == TypeRawPtr::NOTNULL) {
3015 // Verify a raw address for a store captured by Initialize node.
3016 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
3017 assert(offs != Type::OffsetBot, "offset must be a constant");
3018 }
3019 #endif
3020 if (first_iteration) {
3021 delayed_worklist->push(n);
3022 return; // Process it later.
3023 } else {
3024 // Point Address to Value
3025 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
3026 assert(adr_ptn != NULL &&
3027 adr_ptn->as_Field()->is_oop(), "node should be registered");
3028 Node *val = n->in(MemNode::ValueIn);
3029 PointsToNode* ptn = ptnode_adr(val->_idx);
3030 assert(ptn != NULL, "node should be registered");
3031 add_edge(adr_ptn, ptn);
3032 }
3033 #ifdef ASSERT
3034 } else {
3035 // Ignore copy the displaced header to the BoxNode (OSR compilation).
3036 if (adr->is_BoxLock())
3037 break;
3038
3039 if (!adr->is_AddP()) {
3040 n->dump(1);
3041 assert(adr->is_AddP(), "expecting an AddP");
3042 }
3043 // Ignore G1 barrier's stores.
3044 if (!UseG1GC || (opcode != Op_StoreP) ||
3045 (adr_type != TypeRawPtr::BOTTOM)) {
3046 n->dump(1);
3047 assert(false, "not G1 barrier raw StoreP");
3048 }
3049 #endif
3050 }
3051 break;
3052 }
3053 case Op_AryEq:
3054 case Op_StrComp:
3055 case Op_StrEquals:
3056 case Op_StrIndexOf:
3057 {
3058 if (first_iteration) {
3059 add_local_var(n, PointsToNode::ArgEscape);
3060 delayed_worklist->push(n);
3061 return; // Process it later.
3062 } else {
3063 // char[] arrays passed to string intrinsic do not escape but
3064 // they are not scalar replaceable. Adjust escape state for them.
3065 // Start from in(2) edge since in(1) is memory edge.
3066 for (uint i = 2; i < n->req(); i++) {
3067 Node* adr = n->in(i);
3068 const Type* at = phase->type(adr);
3069 if (!adr->is_top() && at->isa_ptr()) {
3070 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
3071 at->isa_ptr() != NULL, "expecting a pointer");
3072 if (adr->is_AddP()) {
3073 adr = get_addp_base(adr);
3074 }
3075 PointsToNode* ptn = ptnode_adr(adr->_idx);
3076 assert(ptn != NULL, "node should be registered");
3077 add_edge(n_ptn, ptn);
3078 }
3079 }
3080 }
3081 break;
3082 }
3083 case Op_ThreadLocal:
3084 {
3085 if (first_iteration) {
3086 add_java_object(n, PointsToNode::ArgEscape);
3087 } else {
3088 assert(false, "Op_ThreadLocal");
3089 }
3090 break;
3091 }
3092 default:
3093 if (first_iteration) {
3094 ; // nothing to do
3095 } else {
3096 // This method should be called only for EA specific nodes during second iteration.
3097 ShouldNotReachHere();
3098 }
3099 }
3100 return;
3101 }
3102
3103 #ifndef PRODUCT
3104 static const char *node_type_names[] = {
3105 "UnknownType",
3106 "JavaObject",
3107 "LocalVar",
3108 "Field",
3109 "Arraycopy"
3110 };
3111
3112 static const char *esc_names[] = {
3113 "UnknownEscape",
3114 "NoEscape",
3115 "ArgEscape",
3116 "GlobalEscape"
3117 };
3118
3119 void PointsToNode::dump(bool print_state) const {
3120 NodeType nt = node_type();
3121 tty->print("%s ", node_type_names[(int) nt]);
3122 if (print_state) {
3123 EscapeState es = escape_state();
3124 EscapeState fields_es = fields_escape_state();
3125 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3126 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3127 tty->print("NSR");
3128 }
3129 if (is_Field()) {
3130 FieldNode* f = (FieldNode*)this;
3131 tty->print("(");
3132 for (uint i = 0; i < f->base_count(); i++) {
3133 PointsToNode* b = f->base(i);
3134 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3135 }
3136 tty->print(" )");
3137 }
3138 tty->print("[");
3139 for (uint i = 0; i < edge_count(); i++) {
3140 PointsToNode* e = edge(i);
3141 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3142 }
3143 tty->print(" [");
3144 for (uint i = 0; i < use_count(); i++) {
3145 PointsToNode* u = use(i);
3146 bool is_base = false;
3147 if (PointsToNode::is_base_use(u)) {
3148 is_base = true;
3149 u = PointsToNode::get_use_node(u)->as_Field();
3150 }
3151 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3152 }
3153 tty->print(" ]] ");
3154 if (_node == NULL)
3155 tty->print_cr("<null>");
3156 else
3157 _node->dump();
3158 }
3159
3160 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3161 bool first = true;
3162
3163 uint ptnodes_length = ptnodes_worklist.length();
3164 for (uint i = 0; i < ptnodes_length; i++) {
3165 PointsToNode *ptn = ptnodes_worklist.at(i);
3166 if (ptn == NULL || !ptn->is_JavaObject())
3167 continue;
3168 PointsToNode::EscapeState es = ptn->escape_state();
3169 if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3170 if (first) {
3171 tty->cr();
3172 tty->print("======== Connection graph for ");
3173 _compile->method()->print_short_name();
3174 tty->cr();
3175 first = false;
3176 }
3177 ptn->dump();
3178 // Print all locals and fields which reference this allocation
3179 uint count = ptn->use_count();
3180 for (uint i = 0; i < count; i++) {
3181 PointsToNode* use = ptn->use(i);
3182 if (use->is_LocalVar()) {
3183 use->dump(Verbose);
3184 } else if (Verbose) {
3185 use->dump();
3186 }
3187 }
3188 tty->cr();
3189 }
3190 }
3191 }
3192 #endif