17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "libadt/vectset.hpp"
28 #include "memory/allocation.hpp"
29 #include "opto/c2compiler.hpp"
30 #include "opto/callnode.hpp"
31 #include "opto/cfgnode.hpp"
32 #include "opto/compile.hpp"
33 #include "opto/escape.hpp"
34 #include "opto/phaseX.hpp"
35 #include "opto/rootnode.hpp"
36
37 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
38 uint v = (targIdx << EdgeShift) + ((uint) et);
39 if (_edges == NULL) {
40 Arena *a = Compile::current()->comp_arena();
41 _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
42 }
43 _edges->append_if_missing(v);
44 }
45
46 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
47 uint v = (targIdx << EdgeShift) + ((uint) et);
48
49 _edges->remove(v);
50 }
51
52 #ifndef PRODUCT
53 static const char *node_type_names[] = {
54 "UnknownType",
55 "JavaObject",
56 "LocalVar",
57 "Field"
58 };
59
60 static const char *esc_names[] = {
61 "UnknownEscape",
62 "NoEscape",
63 "ArgEscape",
64 "GlobalEscape"
65 };
66
67 static const char *edge_type_suffix[] = {
68 "?", // UnknownEdge
69 "P", // PointsToEdge
70 "D", // DeferredEdge
71 "F" // FieldEdge
72 };
73
74 void PointsToNode::dump(bool print_state) const {
75 NodeType nt = node_type();
76 tty->print("%s ", node_type_names[(int) nt]);
77 if (print_state) {
78 EscapeState es = escape_state();
79 tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
80 }
81 tty->print("[[");
82 for (uint i = 0; i < edge_count(); i++) {
83 tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
84 }
85 tty->print("]] ");
86 if (_node == NULL)
87 tty->print_cr("<null>");
88 else
89 _node->dump();
90 }
91 #endif
92
93 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
94 _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
95 _processed(C->comp_arena()),
96 pt_ptset(C->comp_arena()),
97 pt_visited(C->comp_arena()),
98 pt_worklist(C->comp_arena(), 4, 0, 0),
99 _collecting(true),
100 _progress(false),
101 _compile(C),
102 _igvn(igvn),
103 _node_map(C->comp_arena()) {
104
105 _phantom_object = C->top()->_idx,
106 add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
107
108 // Add ConP(#NULL) and ConN(#NULL) nodes.
109 Node* oop_null = igvn->zerocon(T_OBJECT);
110 _oop_null = oop_null->_idx;
111 assert(_oop_null < nodes_size(), "should be created already");
112 add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
113
114 if (UseCompressedOops) {
115 Node* noop_null = igvn->zerocon(T_NARROWOOP);
116 _noop_null = noop_null->_idx;
117 assert(_noop_null < nodes_size(), "should be created already");
118 add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
119 } else {
120 _noop_null = _oop_null; // Should be initialized
121 }
122 _pcmp_neq = NULL; // Should be initialized
123 _pcmp_eq = NULL;
124 }
125
126 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
127 PointsToNode *f = ptnode_adr(from_i);
128 PointsToNode *t = ptnode_adr(to_i);
129
130 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
131 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
132 assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
133 if (to_i == _phantom_object) { // Quick test for most common object
134 if (f->has_unknown_ptr()) {
135 return;
136 } else {
137 f->set_has_unknown_ptr();
138 }
139 }
140 add_edge(f, to_i, PointsToNode::PointsToEdge);
141 }
142
143 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
144 PointsToNode *f = ptnode_adr(from_i);
145 PointsToNode *t = ptnode_adr(to_i);
146
147 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
148 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
149 assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
150 // don't add a self-referential edge, this can occur during removal of
151 // deferred edges
152 if (from_i != to_i)
153 add_edge(f, to_i, PointsToNode::DeferredEdge);
154 }
155
156 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
157 const Type *adr_type = phase->type(adr);
158 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
159 adr->in(AddPNode::Address)->is_Proj() &&
160 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
161 // We are computing a raw address for a store captured by an Initialize
162 // compute an appropriate address type. AddP cases #3 and #5 (see below).
163 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
164 assert(offs != Type::OffsetBot ||
165 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
166 "offset must be a constant or it is initialization of array");
167 return offs;
168 }
169 const TypePtr *t_ptr = adr_type->isa_ptr();
170 assert(t_ptr != NULL, "must be a pointer type");
171 return t_ptr->offset();
172 }
173
174 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
175 // Don't add fields to NULL pointer.
176 if (is_null_ptr(from_i))
177 return;
178 PointsToNode *f = ptnode_adr(from_i);
179 PointsToNode *t = ptnode_adr(to_i);
180
181 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
182 assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
183 assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
184 assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
185 t->set_offset(offset);
186
187 add_edge(f, to_i, PointsToNode::FieldEdge);
188 }
189
190 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
191 // Don't change non-escaping state of NULL pointer.
192 if (is_null_ptr(ni))
193 return;
194 PointsToNode *npt = ptnode_adr(ni);
195 PointsToNode::EscapeState old_es = npt->escape_state();
196 if (es > old_es)
197 npt->set_escape_state(es);
198 }
199
200 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
201 PointsToNode::EscapeState es, bool done) {
202 PointsToNode* ptadr = ptnode_adr(n->_idx);
203 ptadr->_node = n;
204 ptadr->set_node_type(nt);
205
206 // inline set_escape_state(idx, es);
207 PointsToNode::EscapeState old_es = ptadr->escape_state();
208 if (es > old_es)
209 ptadr->set_escape_state(es);
210
211 if (done)
212 _processed.set(n->_idx);
213 }
214
215 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
216 uint idx = n->_idx;
217 PointsToNode::EscapeState es;
218
219 // If we are still collecting or there were no non-escaping allocations
220 // we don't know the answer yet
221 if (_collecting)
222 return PointsToNode::UnknownEscape;
223
224 // if the node was created after the escape computation, return
225 // UnknownEscape
226 if (idx >= nodes_size())
227 return PointsToNode::UnknownEscape;
228
229 es = ptnode_adr(idx)->escape_state();
230
231 // if we have already computed a value, return it
232 if (es != PointsToNode::UnknownEscape &&
233 ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
234 return es;
235
236 // PointsTo() calls n->uncast() which can return a new ideal node.
237 if (n->uncast()->_idx >= nodes_size())
238 return PointsToNode::UnknownEscape;
239
240 PointsToNode::EscapeState orig_es = es;
241
242 // compute max escape state of anything this node could point to
243 for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
244 uint pt = i.elem;
245 PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
246 if (pes > es)
247 es = pes;
248 }
249 if (orig_es != es) {
250 // cache the computed escape state
251 assert(es > orig_es, "should have computed an escape state");
252 set_escape_state(idx, es);
253 } // orig_es could be PointsToNode::UnknownEscape
254 return es;
255 }
256
257 VectorSet* ConnectionGraph::PointsTo(Node * n) {
258 pt_ptset.Reset();
259 pt_visited.Reset();
260 pt_worklist.clear();
261
262 #ifdef ASSERT
263 Node *orig_n = n;
264 #endif
265
266 n = n->uncast();
267 PointsToNode* npt = ptnode_adr(n->_idx);
268
269 // If we have a JavaObject, return just that object
270 if (npt->node_type() == PointsToNode::JavaObject) {
271 pt_ptset.set(n->_idx);
272 return &pt_ptset;
273 }
274 #ifdef ASSERT
275 if (npt->_node == NULL) {
276 if (orig_n != n)
277 orig_n->dump();
278 n->dump();
279 assert(npt->_node != NULL, "unregistered node");
280 }
281 #endif
282 pt_worklist.push(n->_idx);
283 while(pt_worklist.length() > 0) {
284 int ni = pt_worklist.pop();
285 if (pt_visited.test_set(ni))
286 continue;
287
288 PointsToNode* pn = ptnode_adr(ni);
289 // ensure that all inputs of a Phi have been processed
290 assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
291
292 int edges_processed = 0;
293 uint e_cnt = pn->edge_count();
294 for (uint e = 0; e < e_cnt; e++) {
295 uint etgt = pn->edge_target(e);
296 PointsToNode::EdgeType et = pn->edge_type(e);
297 if (et == PointsToNode::PointsToEdge) {
298 pt_ptset.set(etgt);
299 edges_processed++;
300 } else if (et == PointsToNode::DeferredEdge) {
301 pt_worklist.push(etgt);
302 edges_processed++;
303 } else {
304 assert(false,"neither PointsToEdge or DeferredEdge");
305 }
306 }
307 if (edges_processed == 0) {
308 // no deferred or pointsto edges found. Assume the value was set
309 // outside this method. Add the phantom object to the pointsto set.
310 pt_ptset.set(_phantom_object);
311 }
312 }
313 return &pt_ptset;
314 }
315
316 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
317 // This method is most expensive during ConnectionGraph construction.
318 // Reuse vectorSet and an additional growable array for deferred edges.
319 deferred_edges->clear();
320 visited->Reset();
321
322 visited->set(ni);
323 PointsToNode *ptn = ptnode_adr(ni);
324 assert(ptn->node_type() == PointsToNode::LocalVar ||
325 ptn->node_type() == PointsToNode::Field, "sanity");
326 assert(ptn->edge_count() != 0, "should have at least phantom_object");
327
328 // Mark current edges as visited and move deferred edges to separate array.
329 for (uint i = 0; i < ptn->edge_count(); ) {
330 uint t = ptn->edge_target(i);
331 #ifdef ASSERT
332 assert(!visited->test_set(t), "expecting no duplications");
333 #else
334 visited->set(t);
335 #endif
336 if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
337 ptn->remove_edge(t, PointsToNode::DeferredEdge);
338 deferred_edges->append(t);
339 } else {
340 i++;
341 }
342 }
343 for (int next = 0; next < deferred_edges->length(); ++next) {
344 uint t = deferred_edges->at(next);
345 PointsToNode *ptt = ptnode_adr(t);
346 uint e_cnt = ptt->edge_count();
347 assert(e_cnt != 0, "should have at least phantom_object");
348 for (uint e = 0; e < e_cnt; e++) {
349 uint etgt = ptt->edge_target(e);
350 if (visited->test_set(etgt))
351 continue;
352
353 PointsToNode::EdgeType et = ptt->edge_type(e);
354 if (et == PointsToNode::PointsToEdge) {
355 add_pointsto_edge(ni, etgt);
356 } else if (et == PointsToNode::DeferredEdge) {
357 deferred_edges->append(etgt);
358 } else {
359 assert(false,"invalid connection graph");
360 }
361 }
362 }
363 if (ptn->edge_count() == 0) {
364 // No pointsto edges found after deferred edges are removed.
365 // For example, in the next case where call is replaced
366 // with uncommon trap and as result array's load references
367 // itself through deferred edges:
368 //
369 // A a = b[i];
370 // if (c!=null) a = c.foo();
371 // b[i] = a;
372 //
373 // Assume the value was set outside this method and
374 // add edge to phantom object.
375 add_pointsto_edge(ni, _phantom_object);
376 }
377 }
378
379
380 // Add an edge to node given by "to_i" from any field of adr_i whose offset
381 // matches "offset" A deferred edge is added if to_i is a LocalVar, and
382 // a pointsto edge is added if it is a JavaObject
383
384 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
385 // No fields for NULL pointer.
386 if (is_null_ptr(adr_i)) {
387 return;
388 }
389 PointsToNode* an = ptnode_adr(adr_i);
390 PointsToNode* to = ptnode_adr(to_i);
391 bool deferred = (to->node_type() == PointsToNode::LocalVar);
392 bool escaped = (to_i == _phantom_object) && (offs == Type::OffsetTop);
393 if (escaped) {
394 // Values in fields escaped during call.
395 assert(an->escape_state() >= PointsToNode::ArgEscape, "sanity");
396 offs = Type::OffsetBot;
397 }
398 for (uint fe = 0; fe < an->edge_count(); fe++) {
399 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
400 int fi = an->edge_target(fe);
401 if (escaped) {
402 set_escape_state(fi, PointsToNode::GlobalEscape);
403 }
404 PointsToNode* pf = ptnode_adr(fi);
405 int po = pf->offset();
406 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
407 if (deferred)
408 add_deferred_edge(fi, to_i);
409 else
410 add_pointsto_edge(fi, to_i);
411 }
412 }
413 }
414
415 // Add a deferred edge from node given by "from_i" to any field of adr_i
416 // whose offset matches "offset".
417 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
418 // No fields for NULL pointer.
419 if (is_null_ptr(adr_i)) {
420 return;
421 }
422 if (adr_i == _phantom_object) {
423 // Add only one edge for unknown object.
424 add_pointsto_edge(from_i, _phantom_object);
425 return;
426 }
427 PointsToNode* an = ptnode_adr(adr_i);
428 bool is_alloc = an->_node->is_Allocate();
429 for (uint fe = 0; fe < an->edge_count(); fe++) {
430 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
431 int fi = an->edge_target(fe);
432 PointsToNode* pf = ptnode_adr(fi);
433 int offset = pf->offset();
434 if (!is_alloc) {
435 // Assume the field was set outside this method if it is not Allocation
436 add_pointsto_edge(fi, _phantom_object);
437 }
438 if (offset == offs || offset == Type::OffsetBot || offs == Type::OffsetBot) {
439 add_deferred_edge(from_i, fi);
440 }
441 }
442 // Some fields references (AddP) may still be missing
443 // until Connection Graph construction is complete.
444 // For example, loads from RAW pointers with offset 0
445 // which don't have AddP.
446 // A reference to phantom_object will be added if
447 // a field reference is still missing after completing
448 // Connection Graph (see remove_deferred()).
449 }
450
451 // Helper functions
452
453 static Node* get_addp_base(Node *addp) {
454 assert(addp->is_AddP(), "must be AddP");
455 //
456 // AddP cases for Base and Address inputs:
457 // case #1. Direct object's field reference:
458 // Allocate
459 // |
460 // Proj #5 ( oop result )
461 // |
462 // CheckCastPP (cast to instance type)
463 // | |
464 // AddP ( base == address )
465 //
466 // case #2. Indirect object's field reference:
467 // Phi
468 // |
469 // CastPP (cast to instance type)
470 // | |
471 // AddP ( base == address )
472 //
473 // case #3. Raw object's field reference for Initialize node:
496 //
497 // case #6. Constant Pool, ThreadLocal, CastX2P or
498 // Raw object's field reference:
499 // {ConP, ThreadLocal, CastX2P, raw Load}
500 // top |
501 // \ |
502 // AddP ( base == top )
503 //
504 // case #7. Klass's field reference.
505 // LoadKlass
506 // | |
507 // AddP ( base == address )
508 //
509 // case #8. narrow Klass's field reference.
510 // LoadNKlass
511 // |
512 // DecodeN
513 // | |
514 // AddP ( base == address )
515 //
516 Node *base = addp->in(AddPNode::Base)->uncast();
517 if (base->is_top()) { // The AddP case #3 and #6.
518 base = addp->in(AddPNode::Address)->uncast();
519 while (base->is_AddP()) {
520 // Case #6 (unsafe access) may have several chained AddP nodes.
521 assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
522 base = base->in(AddPNode::Address)->uncast();
523 }
524 assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
525 base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
526 (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
527 (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
528 }
529 return base;
530 }
531
532 static Node* find_second_addp(Node* addp, Node* n) {
533 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
534
535 Node* addp2 = addp->raw_out(0);
536 if (addp->outcnt() == 1 && addp2->is_AddP() &&
537 addp2->in(AddPNode::Base) == n &&
538 addp2->in(AddPNode::Address) == addp) {
539
540 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
541 //
542 // Find array's offset to push it on worklist first and
543 // as result process an array's element offset first (pushed second)
544 // to avoid CastPP for the array's offset.
545 // Otherwise the inserted CastPP (LocalVar) will point to what
546 // the AddP (Field) points to. Which would be wrong since
547 // the algorithm expects the CastPP has the same point as
548 // as AddP's base CheckCastPP (LocalVar).
549 //
550 // ArrayAllocation
551 // |
552 // CheckCastPP
603 //
604 // Or the type 't' could be not related to 'base_t' at all.
605 // It could happened when CHA type is different from MDO type on a dead path
606 // (for example, from instanceof check) which is not collapsed during parsing.
607 //
608 // Do nothing for such AddP node and don't process its users since
609 // this code branch will go away.
610 //
611 if (!t->is_known_instance() &&
612 !base_t->klass()->is_subtype_of(t->klass())) {
613 return false; // bail out
614 }
615
616 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
617 // Do NOT remove the next line: ensure a new alias index is allocated
618 // for the instance type. Note: C++ will not remove it since the call
619 // has side effect.
620 int alias_idx = _compile->get_alias_index(tinst);
621 igvn->set_type(addp, tinst);
622 // record the allocation in the node map
623 assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
624 set_map(addp->_idx, get_map(base->_idx));
625
626 // Set addp's Base and Address to 'base'.
627 Node *abase = addp->in(AddPNode::Base);
628 Node *adr = addp->in(AddPNode::Address);
629 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
630 adr->in(0)->_idx == (uint)inst_id) {
631 // Skip AddP cases #3 and #5.
632 } else {
633 assert(!abase->is_top(), "sanity"); // AddP case #3
634 if (abase != base) {
635 igvn->hash_delete(addp);
636 addp->set_req(AddPNode::Base, base);
637 if (abase == adr) {
638 addp->set_req(AddPNode::Address, base);
639 } else {
640 // AddP case #4 (adr is array's element offset AddP node)
641 #ifdef ASSERT
642 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
643 assert(adr->is_AddP() && atype != NULL &&
644 atype->instance_id() == inst_id, "array's element offset should be processed first");
682 return phi->as_Phi();
683 }
684 }
685 }
686 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
687 if (C->do_escape_analysis() == true && !C->failing()) {
688 // Retry compilation without escape analysis.
689 // If this is the first failure, the sentinel string will "stick"
690 // to the Compile object, and the C2Compiler will see it and retry.
691 C->record_failure(C2Compiler::retry_no_escape_analysis());
692 }
693 return NULL;
694 }
695 orig_phi_worklist.append_if_missing(orig_phi);
696 const TypePtr *atype = C->get_adr_type(alias_idx);
697 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
698 C->copy_node_notes_to(result, orig_phi);
699 igvn->set_type(result, result->bottom_type());
700 record_for_optimizer(result);
701
702 debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
703 assert(pn == NULL || pn == orig_phi, "wrong node");
704 set_map(orig_phi->_idx, result);
705 ptnode_adr(orig_phi->_idx)->_node = orig_phi;
706
707 new_created = true;
708 return result;
709 }
710
711 //
712 // Return a new version of Memory Phi "orig_phi" with the inputs having the
713 // specified alias index.
714 //
715 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
716
717 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
718 Compile *C = _compile;
719 bool new_phi_created;
720 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
721 if (!new_phi_created) {
722 return result;
723 }
724
725 GrowableArray<PhiNode *> phi_list;
762 Node* in = result->in(i);
763 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
764 }
765 // we have finished processing a Phi, see if there are any more to do
766 finished = (phi_list.length() == 0 );
767 if (!finished) {
768 phi = phi_list.pop();
769 idx = cur_input.pop();
770 PhiNode *prev_result = get_map_phi(phi->_idx);
771 prev_result->set_req(idx++, result);
772 result = prev_result;
773 }
774 }
775 return result;
776 }
777
778
779 //
780 // The next methods are derived from methods in MemNode.
781 //
782 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
783 Node *mem = mmem;
784 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
785 // means an array I have not precisely typed yet. Do not do any
786 // alias stuff with it any time soon.
787 if( toop->base() != Type::AnyPtr &&
788 !(toop->klass() != NULL &&
789 toop->klass()->is_java_lang_Object() &&
790 toop->offset() == Type::OffsetBot) ) {
791 mem = mmem->memory_at(alias_idx);
792 // Update input if it is progress over what we have now
793 }
794 return mem;
795 }
796
797 //
798 // Move memory users to their memory slices.
799 //
800 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *igvn) {
801 Compile* C = _compile;
802
803 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
804 assert(tp != NULL, "ptr type");
805 int alias_idx = C->get_alias_index(tp);
806 int general_idx = C->get_general_index(alias_idx);
807
808 // Move users first
809 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
810 Node* use = n->fast_out(i);
1060 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
1061 //
1062 // 40 StoreP 25 7 20 ... alias_index=4
1063 // 50 StoreP 35 7 30 ... alias_index=6
1064 // 60 StoreP 45 40 20 ... alias_index=4
1065 // 70 LoadP _ 50 30 ... alias_index=6
1066 // 80 Phi 75 40 60 Memory alias_index=4
1067 // 120 Phi 75 50 50 Memory alias_index=6
1068 // 90 LoadP _ 120 30 ... alias_index=6
1069 // 100 LoadP _ 80 20 ... alias_index=4
1070 //
1071 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
1072 GrowableArray<Node *> memnode_worklist;
1073 GrowableArray<PhiNode *> orig_phis;
1074
1075 PhaseIterGVN *igvn = _igvn;
1076 uint new_index_start = (uint) _compile->num_alias_types();
1077 Arena* arena = Thread::current()->resource_area();
1078 VectorSet visited(arena);
1079
1080
1081 // Phase 1: Process possible allocations from alloc_worklist.
1082 // Create instance types for the CheckCastPP for allocations where possible.
1083 //
1084 // (Note: don't forget to change the order of the second AddP node on
1085 // the alloc_worklist if the order of the worklist processing is changed,
1086 // see the comment in find_second_addp().)
1087 //
1088 while (alloc_worklist.length() != 0) {
1089 Node *n = alloc_worklist.pop();
1090 uint ni = n->_idx;
1091 const TypeOopPtr* tinst = NULL;
1092 if (n->is_Call()) {
1093 CallNode *alloc = n->as_Call();
1094 // copy escape information to call node
1095 PointsToNode* ptn = ptnode_adr(alloc->_idx);
1096 PointsToNode::EscapeState es = escape_state(alloc);
1097 // We have an allocation or call which returns a Java object,
1098 // see if it is unescaped.
1099 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
1100 continue;
1101
1102 // Find CheckCastPP for the allocate or for the return value of a call
1103 n = alloc->result_cast();
1104 if (n == NULL) { // No uses except Initialize node
1105 if (alloc->is_Allocate()) {
1106 // Set the scalar_replaceable flag for allocation
1107 // so it could be eliminated if it has no uses.
1108 alloc->as_Allocate()->_is_scalar_replaceable = true;
1109 }
1110 continue;
1111 }
1112 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1113 assert(!alloc->is_Allocate(), "allocation should have unique type");
1114 continue;
1115 }
1116
1128 Node *use = n->fast_out(i);
1129 if (use->is_CheckCastPP()) {
1130 cast2 = use;
1131 break;
1132 }
1133 }
1134 if (cast2 != NULL) {
1135 n = cast2;
1136 } else {
1137 // Non-scalar replaceable if the allocation type is unknown statically
1138 // (reflection allocation), the object can't be restored during
1139 // deoptimization without precise type.
1140 continue;
1141 }
1142 }
1143 if (alloc->is_Allocate()) {
1144 // Set the scalar_replaceable flag for allocation
1145 // so it could be eliminated.
1146 alloc->as_Allocate()->_is_scalar_replaceable = true;
1147 }
1148 set_escape_state(n->_idx, es); // CheckCastPP escape state
1149 // in order for an object to be scalar-replaceable, it must be:
1150 // - a direct allocation (not a call returning an object)
1151 // - non-escaping
1152 // - eligible to be a unique type
1153 // - not determined to be ineligible by escape analysis
1154 assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1155 ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1156 set_map(alloc->_idx, n);
1157 set_map(n->_idx, alloc);
1158 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1159 if (t == NULL)
1160 continue; // not a TypeOopPtr
1161 tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1162 igvn->hash_delete(n);
1163 igvn->set_type(n, tinst);
1164 n->raise_bottom_type(tinst);
1165 igvn->hash_insert(n);
1166 record_for_optimizer(n);
1167 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
1168
1169 // First, put on the worklist all Field edges from Connection Graph
1170 // which is more accurate then putting immediate users from Ideal Graph.
1171 for (uint e = 0; e < ptn->edge_count(); e++) {
1172 Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1173 assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
1174 "only AddP nodes are Field edges in CG");
1175 if (use->outcnt() > 0) { // Don't process dead nodes
1176 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1177 if (addp2 != NULL) {
1178 assert(alloc->is_AllocateArray(),"array allocation was expected");
1179 alloc_worklist.append_if_missing(addp2);
1180 }
1181 alloc_worklist.append_if_missing(use);
1182 }
1183 }
1184
1185 // An allocation may have an Initialize which has raw stores. Scan
1186 // the users of the raw allocation result and push AddP users
1187 // on alloc_worklist.
1188 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1189 assert (raw_result != NULL, "must have an allocation result");
1190 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1191 Node *use = raw_result->fast_out(i);
1192 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1193 Node* addp2 = find_second_addp(use, raw_result);
1194 if (addp2 != NULL) {
1195 assert(alloc->is_AllocateArray(),"array allocation was expected");
1196 alloc_worklist.append_if_missing(addp2);
1197 }
1198 alloc_worklist.append_if_missing(use);
1199 } else if (use->is_MemBar()) {
1200 memnode_worklist.append_if_missing(use);
1201 }
1202 }
1203 }
1204 } else if (n->is_AddP()) {
1205 VectorSet* ptset = PointsTo(get_addp_base(n));
1206 assert(ptset->Size() == 1, "AddP address is unique");
1207 uint elem = ptset->getelem(); // Allocation node's index
1208 if (elem == _phantom_object) {
1209 assert(false, "escaped allocation");
1210 continue; // Assume the value was set outside this method.
1211 }
1212 Node *base = get_map(elem); // CheckCastPP node
1213 if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1214 tinst = igvn->type(base)->isa_oopptr();
1215 } else if (n->is_Phi() ||
1216 n->is_CheckCastPP() ||
1217 n->is_EncodeP() ||
1218 n->is_DecodeN() ||
1219 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1220 if (visited.test_set(n->_idx)) {
1221 assert(n->is_Phi(), "loops only through Phi's");
1222 continue; // already processed
1223 }
1224 VectorSet* ptset = PointsTo(n);
1225 if (ptset->Size() == 1) {
1226 uint elem = ptset->getelem(); // Allocation node's index
1227 if (elem == _phantom_object) {
1228 assert(false, "escaped allocation");
1229 continue; // Assume the value was set outside this method.
1230 }
1231 Node *val = get_map(elem); // CheckCastPP node
1232 TypeNode *tn = n->as_Type();
1233 tinst = igvn->type(val)->isa_oopptr();
1234 assert(tinst != NULL && tinst->is_known_instance() &&
1235 (uint)tinst->instance_id() == elem , "instance type expected.");
1236
1237 const Type *tn_type = igvn->type(tn);
1238 const TypeOopPtr *tn_t;
1239 if (tn_type->isa_narrowoop()) {
1240 tn_t = tn_type->make_ptr()->isa_oopptr();
1241 } else {
1242 tn_t = tn_type->isa_oopptr();
1243 }
1244
1245 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1246 if (tn_type->isa_narrowoop()) {
1247 tn_type = tinst->make_narrowoop();
1248 } else {
1249 tn_type = tinst;
1250 }
1251 igvn->hash_delete(tn);
1252 igvn->set_type(tn, tn_type);
1253 tn->set_type(tn_type);
1254 igvn->hash_insert(tn);
1255 record_for_optimizer(n);
1298 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1299 }
1300 } else {
1301 uint op = use->Opcode();
1302 if (!(op == Op_CmpP || op == Op_Conv2B ||
1303 op == Op_CastP2X || op == Op_StoreCM ||
1304 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1305 op == Op_StrEquals || op == Op_StrIndexOf)) {
1306 n->dump();
1307 use->dump();
1308 assert(false, "EA: missing allocation reference path");
1309 }
1310 #endif
1311 }
1312 }
1313
1314 }
1315 // New alias types were created in split_AddP().
1316 uint new_index_end = (uint) _compile->num_alias_types();
1317
1318 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1319 // compute new values for Memory inputs (the Memory inputs are not
1320 // actually updated until phase 4.)
1321 if (memnode_worklist.length() == 0)
1322 return; // nothing to do
1323
1324 while (memnode_worklist.length() != 0) {
1325 Node *n = memnode_worklist.pop();
1326 if (visited.test_set(n->_idx))
1327 continue;
1328 if (n->is_Phi() || n->is_ClearArray()) {
1329 // we don't need to do anything, but the users must be pushed
1330 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1331 // we don't need to do anything, but the users must be pushed
1332 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1333 if (n == NULL)
1334 continue;
1335 } else {
1336 assert(n->is_Mem(), "memory node required.");
1337 Node *addr = n->in(MemNode::Address);
1338 const Type *addr_t = igvn->type(addr);
1339 if (addr_t == Type::TOP)
1340 continue;
1341 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1342 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1343 assert ((uint)alias_idx < new_index_end, "wrong alias index");
1344 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1345 if (_compile->failing()) {
1346 return;
1347 }
1348 if (mem != n->in(MemNode::Memory)) {
1349 // We delay the memory edge update since we need old one in
1350 // MergeMem code below when instances memory slices are separated.
1351 debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1352 assert(pn == NULL || pn == n, "wrong node");
1353 set_map(n->_idx, mem);
1354 ptnode_adr(n->_idx)->_node = n;
1355 }
1356 if (n->is_Load()) {
1357 continue; // don't push users
1358 } else if (n->is_LoadStore()) {
1359 // get the memory projection
1360 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1361 Node *use = n->fast_out(i);
1362 if (use->Opcode() == Op_SCMemProj) {
1363 n = use;
1364 break;
1365 }
1366 }
1367 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1368 }
1369 }
1370 // push user on appropriate worklist
1371 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1372 Node *use = n->fast_out(i);
1373 if (use->is_Phi() || use->is_ClearArray()) {
1374 memnode_worklist.append_if_missing(use);
1486 if (_compile->failing()) {
1487 return;
1488 }
1489 if (mem != new_mem) {
1490 phi->set_req(i, new_mem);
1491 }
1492 }
1493 igvn->hash_insert(phi);
1494 record_for_optimizer(phi);
1495 }
1496
1497 // Update the memory inputs of MemNodes with the value we computed
1498 // in Phase 2 and move stores memory users to corresponding memory slices.
1499
1500 // Disable memory split verification code until the fix for 6984348.
1501 // Currently it produces false negative results since it does not cover all cases.
1502 #if 0 // ifdef ASSERT
1503 visited.Reset();
1504 Node_Stack old_mems(arena, _compile->unique() >> 2);
1505 #endif
1506 for (uint i = 0; i < nodes_size(); i++) {
1507 Node *nmem = get_map(i);
1508 if (nmem != NULL) {
1509 Node *n = ptnode_adr(i)->_node;
1510 assert(n != NULL, "sanity");
1511 if (n->is_Mem()) {
1512 #if 0 // ifdef ASSERT
1513 Node* old_mem = n->in(MemNode::Memory);
1514 if (!visited.test_set(old_mem->_idx)) {
1515 old_mems.push(old_mem, old_mem->outcnt());
1516 }
1517 #endif
1518 assert(n->in(MemNode::Memory) != nmem, "sanity");
1519 if (!n->is_Load()) {
1520 // Move memory users of a store first.
1521 move_inst_mem(n, orig_phis, igvn);
1522 }
1523 // Now update memory input
1524 igvn->hash_delete(n);
1525 n->set_req(MemNode::Memory, nmem);
1526 igvn->hash_insert(n);
1527 record_for_optimizer(n);
1528 } else {
1529 assert(n->is_Allocate() || n->is_CheckCastPP() ||
1530 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1531 }
1532 }
1533 }
1534 #if 0 // ifdef ASSERT
1535 // Verify that memory was split correctly
1536 while (old_mems.is_nonempty()) {
1537 Node* old_mem = old_mems.node();
1538 uint old_cnt = old_mems.index();
1539 old_mems.pop();
1540 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
1541 }
1542 #endif
1543 }
1544
1545 bool ConnectionGraph::has_candidates(Compile *C) {
1546 // EA brings benefits only when the code has allocations and/or locks which
1547 // are represented by ideal Macro nodes.
1548 int cnt = C->macro_count();
1549 for( int i=0; i < cnt; i++ ) {
1550 Node *n = C->macro_node(i);
1551 if ( n->is_Allocate() )
1552 return true;
1553 if( n->is_Lock() ) {
1554 Node* obj = n->as_Lock()->obj_node()->uncast();
1555 if( !(obj->is_Parm() || obj->is_Con()) )
1556 return true;
1557 }
1558 }
1559 return false;
1560 }
1561
1562 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1563 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1564 // to create space for them in ConnectionGraph::_nodes[].
1565 Node* oop_null = igvn->zerocon(T_OBJECT);
1566 Node* noop_null = igvn->zerocon(T_NARROWOOP);
1567
1568 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1569 // Perform escape analysis
1570 if (congraph->compute_escape()) {
1571 // There are non escaping objects.
1572 C->set_congraph(congraph);
1573 }
1574
1575 // Cleanup.
1576 if (oop_null->outcnt() == 0)
1577 igvn->hash_delete(oop_null);
1578 if (noop_null->outcnt() == 0)
1579 igvn->hash_delete(noop_null);
1580 }
1581
1582 bool ConnectionGraph::compute_escape() {
1583 Compile* C = _compile;
1584
1585 // 1. Populate Connection Graph (CG) with Ideal nodes.
1586
1587 Unique_Node_List worklist_init;
1588 worklist_init.map(C->unique(), NULL); // preallocate space
1589
1590 // Initialize worklist
1591 if (C->root() != NULL) {
1592 worklist_init.push(C->root());
1593 }
1594
1595 GrowableArray<Node*> alloc_worklist;
1596 GrowableArray<Node*> addp_worklist;
1597 GrowableArray<Node*> ptr_cmp_worklist;
1598 GrowableArray<Node*> storestore_worklist;
1599 PhaseGVN* igvn = _igvn;
1600
1601 // Push all useful nodes onto CG list and set their type.
1602 for( uint next = 0; next < worklist_init.size(); ++next ) {
1603 Node* n = worklist_init.at(next);
1604 record_for_escape_analysis(n, igvn);
1605 // Only allocations and java static calls results are checked
1606 // for an escape status. See process_call_result() below.
1607 if (n->is_Allocate() || n->is_CallStaticJava() &&
1608 ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1609 alloc_worklist.append(n);
1610 } else if(n->is_AddP()) {
1611 // Collect address nodes. Use them during stage 3 below
1612 // to build initial connection graph field edges.
1613 addp_worklist.append(n);
1614 } else if (n->is_MergeMem()) {
1615 // Collect all MergeMem nodes to add memory slices for
1616 // scalar replaceable objects in split_unique_types().
1617 _mergemem_worklist.append(n->as_MergeMem());
1618 } else if (OptimizePtrCompare && n->is_Cmp() &&
1619 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
1620 // Compare pointers nodes
1621 ptr_cmp_worklist.append(n);
1622 } else if (n->is_MemBarStoreStore()) {
1623 // Collect all MemBarStoreStore nodes so that depending on the
1624 // escape status of the associated Allocate node some of them
1625 // may be eliminated.
1626 storestore_worklist.append(n);
1627 }
1628 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1629 Node* m = n->fast_out(i); // Get user
1630 worklist_init.push(m);
1631 }
1632 }
1633
1634 if (alloc_worklist.length() == 0) {
1635 _collecting = false;
1636 return false; // Nothing to do.
1637 }
1638
1639 // 2. First pass to create simple CG edges (doesn't require to walk CG).
1640 uint delayed_size = _delayed_worklist.size();
1641 for( uint next = 0; next < delayed_size; ++next ) {
1642 Node* n = _delayed_worklist.at(next);
1643 build_connection_graph(n, igvn);
1644 }
1645
1646 // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
1647 // to reduce number of iterations during stage 4 below.
1648 uint addp_length = addp_worklist.length();
1649 for( uint next = 0; next < addp_length; ++next ) {
1650 Node* n = addp_worklist.at(next);
1651 Node* base = get_addp_base(n);
1652 if (base->is_Proj() && base->in(0)->is_Call())
1653 base = base->in(0);
1654 PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
1655 if (nt == PointsToNode::JavaObject) {
1656 build_connection_graph(n, igvn);
1657 }
1658 }
1659
1660 GrowableArray<int> cg_worklist;
1661 cg_worklist.append(_phantom_object);
1662 GrowableArray<uint> worklist;
1663
1664 // 4. Build Connection Graph which need
1665 // to walk the connection graph.
1666 _progress = false;
1667 for (uint ni = 0; ni < nodes_size(); ni++) {
1668 PointsToNode* ptn = ptnode_adr(ni);
1669 Node *n = ptn->_node;
1670 if (n != NULL) { // Call, AddP, LoadP, StoreP
1671 build_connection_graph(n, igvn);
1672 if (ptn->node_type() != PointsToNode::UnknownType)
1673 cg_worklist.append(n->_idx); // Collect CG nodes
1674 if (!_processed.test(n->_idx))
1675 worklist.append(n->_idx); // Collect C/A/L/S nodes
1676 }
1677 }
1678
1679 // After IGVN user nodes may have smaller _idx than
1680 // their inputs so they will be processed first in
1681 // previous loop. Because of that not all Graph
1682 // edges will be created. Walk over interesting
1683 // nodes again until no new edges are created.
1684 //
1685 // Normally only 1-3 passes needed to build
1686 // Connection Graph depending on graph complexity.
1687 // Observed 8 passes in jvm2008 compiler.compiler.
1688 // Set limit to 20 to catch situation when something
1689 // did go wrong and recompile the method without EA.
1690 // Also limit build time to 30 sec (60 in debug VM).
1691
1692 #define CG_BUILD_ITER_LIMIT 20
1693
1694 #ifdef ASSERT
1695 #define CG_BUILD_TIME_LIMIT 60.0
1696 #else
1697 #define CG_BUILD_TIME_LIMIT 30.0
1698 #endif
1699
1700 uint length = worklist.length();
1701 int iterations = 0;
1702 elapsedTimer time;
1703 while(_progress &&
1704 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1705 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1706 time.start();
1707 _progress = false;
1708 for( uint next = 0; next < length; ++next ) {
1709 int ni = worklist.at(next);
1710 PointsToNode* ptn = ptnode_adr(ni);
1711 Node* n = ptn->_node;
1712 assert(n != NULL, "should be known node");
1713 build_connection_graph(n, igvn);
1714 }
1715 time.stop();
1716 }
1717 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1718 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1719 assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1720 time.seconds(), iterations, nodes_size(), length));
1721 // Possible infinite build_connection_graph loop,
1722 // bailout (no changes to ideal graph were made).
1723 _collecting = false;
1724 return false;
1725 }
1726 #undef CG_BUILD_ITER_LIMIT
1727 #undef CG_BUILD_TIME_LIMIT
1728
1729 // 5. Propagate escaped states.
1730 worklist.clear();
1731
1732 // mark all nodes reachable from GlobalEscape nodes
1733 (void)propagate_escape_state(&cg_worklist, &worklist, PointsToNode::GlobalEscape);
1734
1735 // mark all nodes reachable from ArgEscape nodes
1736 bool has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ArgEscape);
1737
1738 Arena* arena = Thread::current()->resource_area();
1739 VectorSet visited(arena);
1740
1741 // 6. Find fields initializing values for not escaped allocations
1742 uint alloc_length = alloc_worklist.length();
1743 for (uint next = 0; next < alloc_length; ++next) {
1744 Node* n = alloc_worklist.at(next);
1745 PointsToNode::EscapeState es = ptnode_adr(n->_idx)->escape_state();
1746 if (es == PointsToNode::NoEscape) {
1747 has_non_escaping_obj = true;
1748 if (n->is_Allocate()) {
1749 find_init_values(n, &visited, igvn);
1750 // The object allocated by this Allocate node will never be
1751 // seen by an other thread. Mark it so that when it is
1752 // expanded no MemBarStoreStore is added.
1753 n->as_Allocate()->initialization()->set_does_not_escape();
1754 }
1755 } else if ((es == PointsToNode::ArgEscape) && n->is_Allocate()) {
1756 // Same as above. Mark this Allocate node so that when it is
1757 // expanded no MemBarStoreStore is added.
1758 n->as_Allocate()->initialization()->set_does_not_escape();
1759 }
1760 }
1761
1762 uint cg_length = cg_worklist.length();
1763
1764 // Skip the rest of code if all objects escaped.
1765 if (!has_non_escaping_obj) {
1766 cg_length = 0;
1767 addp_length = 0;
1768 }
1769
1770 for (uint next = 0; next < cg_length; ++next) {
1771 int ni = cg_worklist.at(next);
1772 PointsToNode* ptn = ptnode_adr(ni);
1773 PointsToNode::NodeType nt = ptn->node_type();
1774 if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1775 if (ptn->edge_count() == 0) {
1776 // No values were found. Assume the value was set
1777 // outside this method - add edge to phantom object.
1778 add_pointsto_edge(ni, _phantom_object);
1779 }
1780 }
1781 }
1782
1783 // 7. Remove deferred edges from the graph.
1784 for (uint next = 0; next < cg_length; ++next) {
1785 int ni = cg_worklist.at(next);
1786 PointsToNode* ptn = ptnode_adr(ni);
1787 PointsToNode::NodeType nt = ptn->node_type();
1788 if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1789 remove_deferred(ni, &worklist, &visited);
1790 }
1791 }
1792
1793 // 8. Adjust escape state of nonescaping objects.
1794 for (uint next = 0; next < addp_length; ++next) {
1795 Node* n = addp_worklist.at(next);
1796 adjust_escape_state(n);
1797 }
1798
1799 // push all NoEscape nodes on the worklist
1800 worklist.clear();
1801 for( uint next = 0; next < cg_length; ++next ) {
1802 int nk = cg_worklist.at(next);
1803 if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape &&
1804 !is_null_ptr(nk))
1805 worklist.push(nk);
1806 }
1807
1808 alloc_worklist.clear();
1809 // Propagate scalar_replaceable value.
1810 while(worklist.length() > 0) {
1811 uint nk = worklist.pop();
1812 PointsToNode* ptn = ptnode_adr(nk);
1813 Node* n = ptn->_node;
1814 bool scalar_replaceable = ptn->scalar_replaceable();
1815 if (n->is_Allocate() && scalar_replaceable) {
1816 // Push scalar replaceable allocations on alloc_worklist
1817 // for processing in split_unique_types(). Note,
1818 // following code may change scalar_replaceable value.
1819 alloc_worklist.append(n);
1820 }
1821 uint e_cnt = ptn->edge_count();
1822 for (uint ei = 0; ei < e_cnt; ei++) {
1823 uint npi = ptn->edge_target(ei);
1824 if (is_null_ptr(npi))
1825 continue;
1826 PointsToNode *np = ptnode_adr(npi);
1827 if (np->escape_state() < PointsToNode::NoEscape) {
1828 set_escape_state(npi, PointsToNode::NoEscape);
1829 if (!scalar_replaceable) {
1830 np->set_scalar_replaceable(false);
1831 }
1832 worklist.push(npi);
1833 } else if (np->scalar_replaceable() && !scalar_replaceable) {
1834 np->set_scalar_replaceable(false);
1835 worklist.push(npi);
1836 }
1837 }
1838 }
1839
1840 _collecting = false;
1841 assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1842
1843 assert(ptnode_adr(_oop_null)->escape_state() == PointsToNode::NoEscape &&
1844 ptnode_adr(_oop_null)->edge_count() == 0, "sanity");
1845 if (UseCompressedOops) {
1846 assert(ptnode_adr(_noop_null)->escape_state() == PointsToNode::NoEscape &&
1847 ptnode_adr(_noop_null)->edge_count() == 0, "sanity");
1848 }
1849
1850 if (EliminateLocks && has_non_escaping_obj) {
1851 // Mark locks before changing ideal graph.
1852 int cnt = C->macro_count();
1853 for( int i=0; i < cnt; i++ ) {
1854 Node *n = C->macro_node(i);
1855 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1856 AbstractLockNode* alock = n->as_AbstractLock();
1857 if (!alock->is_non_esc_obj()) {
1858 PointsToNode::EscapeState es = escape_state(alock->obj_node());
1859 assert(es != PointsToNode::UnknownEscape, "should know");
1860 if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
1861 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1862 // The lock could be marked eliminated by lock coarsening
1863 // code during first IGVN before EA. Replace coarsened flag
1864 // to eliminate all associated locks/unlocks.
1865 alock->set_non_esc_obj();
1866 }
1867 }
1868 }
1869 }
1870 }
1871
1872 if (OptimizePtrCompare && has_non_escaping_obj) {
1873 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1874 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1875 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1876 // Optimize objects compare.
1877 while (ptr_cmp_worklist.length() != 0) {
1878 Node *n = ptr_cmp_worklist.pop();
1879 Node *res = optimize_ptr_compare(n);
1880 if (res != NULL) {
1900 // escape status of associated AllocateNode and optimize out
1901 // MemBarStoreStore node if the allocated object never escapes.
1902 while (storestore_worklist.length() != 0) {
1903 Node *n = storestore_worklist.pop();
1904 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1905 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1906 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1907 PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
1908 if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
1909 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1910 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1911 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1912
1913 _igvn->register_new_node_with_optimizer(mb);
1914 _igvn->replace_node(storestore, mb);
1915 }
1916 }
1917
1918 #ifndef PRODUCT
1919 if (PrintEscapeAnalysis) {
1920 dump(); // Dump ConnectionGraph
1921 }
1922 #endif
1923
1924 bool has_scalar_replaceable_candidates = false;
1925 alloc_length = alloc_worklist.length();
1926 for (uint next = 0; next < alloc_length; ++next) {
1927 Node* n = alloc_worklist.at(next);
1928 PointsToNode* ptn = ptnode_adr(n->_idx);
1929 assert(ptn->escape_state() == PointsToNode::NoEscape, "sanity");
1930 if (ptn->scalar_replaceable()) {
1931 has_scalar_replaceable_candidates = true;
1932 break;
1933 }
1934 }
1935
1936 if ( has_scalar_replaceable_candidates &&
1937 C->AliasLevel() >= 3 && EliminateAllocations ) {
1938
1939 // Now use the escape information to create unique types for
1940 // scalar replaceable objects.
1941 split_unique_types(alloc_worklist);
1942
1943 if (C->failing()) return false;
1944
1945 C->print_method("After Escape Analysis", 2);
1946
1947 #ifdef ASSERT
1948 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1949 tty->print("=== No allocations eliminated for ");
1950 C->method()->print_short_name();
1951 if(!EliminateAllocations) {
1952 tty->print(" since EliminateAllocations is off ===");
1953 } else if(!has_scalar_replaceable_candidates) {
1954 tty->print(" since there are no scalar replaceable candidates ===");
1955 } else if(C->AliasLevel() < 3) {
1956 tty->print(" since AliasLevel < 3 ===");
1957 }
1958 tty->cr();
1959 #endif
1960 }
1961 return has_non_escaping_obj;
1962 }
1963
1964 // Find fields initializing values for allocations.
1965 void ConnectionGraph::find_init_values(Node* alloc, VectorSet* visited, PhaseTransform* phase) {
1966 assert(alloc->is_Allocate(), "Should be called for Allocate nodes only");
1967 PointsToNode* pta = ptnode_adr(alloc->_idx);
1968 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1969 InitializeNode* ini = alloc->as_Allocate()->initialization();
1970
1971 Compile* C = _compile;
1972 visited->Reset();
1973 // Check if a oop field's initializing value is recorded and add
1974 // a corresponding NULL field's value if it is not recorded.
1975 // Connection Graph does not record a default initialization by NULL
1976 // captured by Initialize node.
1977 //
1978 uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1979 uint ae_cnt = pta->edge_count();
1980 bool visited_bottom_offset = false;
1981 for (uint ei = 0; ei < ae_cnt; ei++) {
1982 uint nidx = pta->edge_target(ei); // Field (AddP)
1983 PointsToNode* ptn = ptnode_adr(nidx);
1984 assert(ptn->_node->is_AddP(), "Should be AddP nodes only");
1985 int offset = ptn->offset();
1986 if (offset == Type::OffsetBot) {
1987 if (!visited_bottom_offset) {
1988 visited_bottom_offset = true;
1989 // Check only oop fields.
1990 const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
1991 if (!adr_type->isa_aryptr() ||
1992 (adr_type->isa_aryptr()->klass() == NULL) ||
1993 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1994 // OffsetBot is used to reference array's element,
1995 // always add reference to NULL since we don't
1996 // known which element is referenced.
1997 add_edge_from_fields(alloc->_idx, null_idx, offset);
1998 }
1999 }
2000 } else if (offset != oopDesc::klass_offset_in_bytes() &&
2001 !visited->test_set(offset)) {
2002
2003 // Check only oop fields.
2004 const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
2005 BasicType basic_field_type = T_INT;
2006 if (adr_type->isa_instptr()) {
2007 ciField* field = C->alias_type(adr_type->isa_instptr())->field();
2008 if (field != NULL) {
2009 basic_field_type = field->layout_type();
2010 } else {
2011 // Ignore non field load (for example, klass load)
2012 }
2013 } else if (adr_type->isa_aryptr()) {
2014 if (offset != arrayOopDesc::length_offset_in_bytes()) {
2015 const Type* elemtype = adr_type->isa_aryptr()->elem();
2016 basic_field_type = elemtype->array_element_basic_type();
2017 } else {
2018 // Ignore array length load
2019 }
2020 #ifdef ASSERT
2021 } else {
2022 // Raw pointers are used for initializing stores so skip it
2023 // since it should be recorded already
2024 Node* base = get_addp_base(ptn->_node);
2025 assert(adr_type->isa_rawptr() && base->is_Proj() &&
2026 (base->in(0) == alloc),"unexpected pointer type");
2027 #endif
2028 }
2029 if (basic_field_type == T_OBJECT ||
2030 basic_field_type == T_NARROWOOP ||
2031 basic_field_type == T_ARRAY) {
2032 Node* value = NULL;
2033 if (ini != NULL) {
2034 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
2035 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
2036 if (store != NULL && store->is_Store()) {
2037 value = store->in(MemNode::ValueIn);
2038 } else {
2039 // There could be initializing stores which follow allocation.
2040 // For example, a volatile field store is not collected
2041 // by Initialize node.
2042 //
2043 // Need to check for dependent loads to separate such stores from
2044 // stores which follow loads. For now, add initial value NULL so
2045 // that compare pointers optimization works correctly.
2046 }
2047 }
2048 if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
2049 // A field's initializing value was not recorded. Add NULL.
2050 add_edge_from_fields(alloc->_idx, null_idx, offset);
2051 }
2052 }
2053 }
2054 }
2055 }
2056
2057 // Adjust escape state after Connection Graph is built.
2058 void ConnectionGraph::adjust_escape_state(Node* n) {
2059 PointsToNode* ptn = ptnode_adr(n->_idx);
2060 assert(n->is_AddP(), "Should be called for AddP nodes only");
2061 // Search for objects which are not scalar replaceable
2062 // and mark them to propagate the state to referenced objects.
2063 //
2064
2065 int offset = ptn->offset();
2066 Node* base = get_addp_base(n);
2067 VectorSet* ptset = PointsTo(base);
2068 int ptset_size = ptset->Size();
2069
2070 // An object is not scalar replaceable if the field which may point
2071 // to it has unknown offset (unknown element of an array of objects).
2072 //
2073
2074 if (offset == Type::OffsetBot) {
2075 uint e_cnt = ptn->edge_count();
2076 for (uint ei = 0; ei < e_cnt; ei++) {
2077 uint npi = ptn->edge_target(ei);
2078 ptnode_adr(npi)->set_scalar_replaceable(false);
2079 }
2080 }
2081
2082 // Currently an object is not scalar replaceable if a LoadStore node
2083 // access its field since the field value is unknown after it.
2084 //
2085 bool has_LoadStore = false;
2086 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2087 Node *use = n->fast_out(i);
2088 if (use->is_LoadStore()) {
2089 has_LoadStore = true;
2090 break;
2091 }
2092 }
2093 // An object is not scalar replaceable if the address points
2094 // to unknown field (unknown element for arrays, offset is OffsetBot).
2095 //
2096 // Or the address may point to more then one object. This may produce
2097 // the false positive result (set not scalar replaceable)
2098 // since the flow-insensitive escape analysis can't separate
2099 // the case when stores overwrite the field's value from the case
2100 // when stores happened on different control branches.
2101 //
2102 // Note: it will disable scalar replacement in some cases:
2103 //
2104 // Point p[] = new Point[1];
2105 // p[0] = new Point(); // Will be not scalar replaced
2106 //
2107 // but it will save us from incorrect optimizations in next cases:
2108 //
2109 // Point p[] = new Point[1];
2110 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
2111 //
2112 if (ptset_size > 1 || ptset_size != 0 &&
2113 (has_LoadStore || offset == Type::OffsetBot)) {
2114 for( VectorSetI j(ptset); j.test(); ++j ) {
2115 ptnode_adr(j.elem)->set_scalar_replaceable(false);
2116 }
2117 }
2118 }
2119
2120 // Propagate escape states to referenced nodes.
2121 bool ConnectionGraph::propagate_escape_state(GrowableArray<int>* cg_worklist,
2122 GrowableArray<uint>* worklist,
2123 PointsToNode::EscapeState esc_state) {
2124 bool has_java_obj = false;
2125
2126 // push all nodes with the same escape state on the worklist
2127 uint cg_length = cg_worklist->length();
2128 for (uint next = 0; next < cg_length; ++next) {
2129 int nk = cg_worklist->at(next);
2130 if (ptnode_adr(nk)->escape_state() == esc_state)
2131 worklist->push(nk);
2132 }
2133 // mark all reachable nodes
2134 while (worklist->length() > 0) {
2135 int pt = worklist->pop();
2136 PointsToNode* ptn = ptnode_adr(pt);
2137 if (ptn->node_type() == PointsToNode::JavaObject &&
2138 !is_null_ptr(pt)) {
2139 has_java_obj = true;
2140 if (esc_state > PointsToNode::NoEscape) {
2141 // fields values are unknown if object escapes
2142 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2143 }
2144 }
2145 uint e_cnt = ptn->edge_count();
2146 for (uint ei = 0; ei < e_cnt; ei++) {
2147 uint npi = ptn->edge_target(ei);
2148 if (is_null_ptr(npi))
2149 continue;
2150 PointsToNode *np = ptnode_adr(npi);
2151 if (np->escape_state() < esc_state) {
2152 set_escape_state(npi, esc_state);
2153 worklist->push(npi);
2154 }
2155 }
2156 }
2157 // Has not escaping java objects
2158 return has_java_obj && (esc_state < PointsToNode::GlobalEscape);
2159 }
2160
2161 // Optimize objects compare.
2162 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
2163 assert(OptimizePtrCompare, "sanity");
2164 // Clone returned Set since PointsTo() returns pointer
2165 // to the same structure ConnectionGraph.pt_ptset.
2166 VectorSet ptset1 = *PointsTo(n->in(1));
2167 VectorSet ptset2 = *PointsTo(n->in(2));
2168
2169 // Check simple cases first.
2170 if (ptset1.Size() == 1) {
2171 uint pt1 = ptset1.getelem();
2172 PointsToNode* ptn1 = ptnode_adr(pt1);
2173 if (ptn1->escape_state() == PointsToNode::NoEscape) {
2174 if (ptset2.Size() == 1 && ptset2.getelem() == pt1) {
2175 // Comparing the same not escaping object.
2176 return _pcmp_eq;
2177 }
2178 Node* obj = ptn1->_node;
2179 // Comparing not escaping allocation.
2180 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2181 !ptset2.test(pt1)) {
2182 return _pcmp_neq; // This includes nullness check.
2183 }
2184 }
2185 } else if (ptset2.Size() == 1) {
2186 uint pt2 = ptset2.getelem();
2187 PointsToNode* ptn2 = ptnode_adr(pt2);
2188 if (ptn2->escape_state() == PointsToNode::NoEscape) {
2189 Node* obj = ptn2->_node;
2190 // Comparing not escaping allocation.
2191 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2192 !ptset1.test(pt2)) {
2193 return _pcmp_neq; // This includes nullness check.
2194 }
2195 }
2196 }
2197
2198 if (!ptset1.disjoint(ptset2)) {
2199 return NULL; // Sets are not disjoint
2200 }
2201
2202 // Sets are disjoint.
2203 bool set1_has_unknown_ptr = ptset1.test(_phantom_object) != 0;
2204 bool set2_has_unknown_ptr = ptset2.test(_phantom_object) != 0;
2205 bool set1_has_null_ptr = (ptset1.test(_oop_null) | ptset1.test(_noop_null)) != 0;
2206 bool set2_has_null_ptr = (ptset2.test(_oop_null) | ptset2.test(_noop_null)) != 0;
2207
2208 if (set1_has_unknown_ptr && set2_has_null_ptr ||
2209 set2_has_unknown_ptr && set1_has_null_ptr) {
2210 // Check nullness of unknown object.
2211 return NULL;
2212 }
2213
2214 // Disjointness by itself is not sufficient since
2215 // alias analysis is not complete for escaped objects.
2216 // Disjoint sets are definitely unrelated only when
2217 // at least one set has only not escaping objects.
2218 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2219 bool has_only_non_escaping_alloc = true;
2220 for (VectorSetI i(&ptset1); i.test(); ++i) {
2221 uint pt = i.elem;
2222 PointsToNode* ptn = ptnode_adr(pt);
2223 Node* obj = ptn->_node;
2224 if (ptn->escape_state() != PointsToNode::NoEscape ||
2225 !(obj->is_Allocate() || obj->is_CallStaticJava())) {
2226 has_only_non_escaping_alloc = false;
2227 break;
2228 }
2229 }
2230 if (has_only_non_escaping_alloc) {
2231 return _pcmp_neq;
2232 }
2233 }
2234 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2235 bool has_only_non_escaping_alloc = true;
2236 for (VectorSetI i(&ptset2); i.test(); ++i) {
2237 uint pt = i.elem;
2238 PointsToNode* ptn = ptnode_adr(pt);
2239 Node* obj = ptn->_node;
2240 if (ptn->escape_state() != PointsToNode::NoEscape ||
2241 !(obj->is_Allocate() || obj->is_CallStaticJava())) {
2242 has_only_non_escaping_alloc = false;
2243 break;
2244 }
2245 }
2246 if (has_only_non_escaping_alloc) {
2247 return _pcmp_neq;
2248 }
2249 }
2250 return NULL;
2251 }
2252
2253 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
2254 bool is_arraycopy = false;
2255 switch (call->Opcode()) {
2256 #ifdef ASSERT
2257 case Op_Allocate:
2258 case Op_AllocateArray:
2259 case Op_Lock:
2260 case Op_Unlock:
2261 assert(false, "should be done already");
2262 break;
2263 #endif
2264 case Op_CallLeafNoFP:
2265 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
2266 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
2267 // fall through
2268 case Op_CallLeaf:
2269 {
2270 // Stub calls, objects do not escape but they are not scale replaceable.
2271 // Adjust escape state for outgoing arguments.
2272 const TypeTuple * d = call->tf()->domain();
2273 bool src_has_oops = false;
2274 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2275 const Type* at = d->field_at(i);
2276 Node *arg = call->in(i)->uncast();
2277 const Type *aat = phase->type(arg);
2278 PointsToNode::EscapeState arg_esc = ptnode_adr(arg->_idx)->escape_state();
2279 if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
2280 (is_arraycopy || arg_esc < PointsToNode::ArgEscape)) {
2281 #ifdef ASSERT
2282 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2283 aat->isa_ptr() != NULL, "expecting an Ptr");
2284 if (!(is_arraycopy ||
2285 call->as_CallLeaf()->_name != NULL &&
2286 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
2287 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
2288 ) {
2289 call->dump();
2290 assert(false, "EA: unexpected CallLeaf");
2291 }
2292 #endif
2293 if (arg_esc < PointsToNode::ArgEscape) {
2294 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
2295 Node* arg_base = arg;
2296 if (arg->is_AddP()) {
2297 //
2298 // The inline_native_clone() case when the arraycopy stub is called
2299 // after the allocation before Initialize and CheckCastPP nodes.
2300 // Or normal arraycopy for object arrays case.
2301 //
2302 // Set AddP's base (Allocate) as not scalar replaceable since
2303 // pointer to the base (with offset) is passed as argument.
2304 //
2305 arg_base = get_addp_base(arg);
2306 set_escape_state(arg_base->_idx, PointsToNode::ArgEscape);
2307 }
2308 }
2309
2310 bool arg_has_oops = aat->isa_oopptr() &&
2311 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
2312 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
2313 if (i == TypeFunc::Parms) {
2314 src_has_oops = arg_has_oops;
2315 }
2316 //
2317 // src or dst could be j.l.Object when other is basic type array:
2318 //
2319 // arraycopy(char[],0,Object*,0,size);
2320 // arraycopy(Object*,0,char[],0,size);
2321 //
2322 // Do nothing special in such cases.
2323 //
2324 if (is_arraycopy && (i > TypeFunc::Parms) &&
2325 src_has_oops && arg_has_oops) {
2326 // Destination object's fields reference an unknown object.
2327 Node* arg_base = arg;
2328 if (arg->is_AddP()) {
2329 arg_base = get_addp_base(arg);
2330 }
2331 for (VectorSetI s(PointsTo(arg_base)); s.test(); ++s) {
2332 uint ps = s.elem;
2333 set_escape_state(ps, PointsToNode::ArgEscape);
2334 add_edge_from_fields(ps, _phantom_object, Type::OffsetBot);
2335 }
2336 // Conservatively all values in source object fields globally escape
2337 // since we don't know if values in destination object fields
2338 // escape (it could be traced but it is too expensive).
2339 Node* src = call->in(TypeFunc::Parms)->uncast();
2340 Node* src_base = src;
2341 if (src->is_AddP()) {
2342 src_base = get_addp_base(src);
2343 }
2344 for (VectorSetI s(PointsTo(src_base)); s.test(); ++s) {
2345 uint ps = s.elem;
2346 set_escape_state(ps, PointsToNode::ArgEscape);
2347 // Use OffsetTop to indicate fields global escape.
2348 add_edge_from_fields(ps, _phantom_object, Type::OffsetTop);
2349 }
2350 }
2351 }
2352 }
2353 break;
2354 }
2355
2356 case Op_CallStaticJava:
2357 // For a static call, we know exactly what method is being called.
2358 // Use bytecode estimator to record the call's escape affects
2359 {
2360 ciMethod *meth = call->as_CallJava()->method();
2361 BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
2362 // fall-through if not a Java method or no analyzer information
2363 if (call_analyzer != NULL) {
2364 const TypeTuple * d = call->tf()->domain();
2365 bool copy_dependencies = false;
2366 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2367 const Type* at = d->field_at(i);
2368 int k = i - TypeFunc::Parms;
2369 Node *arg = call->in(i)->uncast();
2370
2371 if (at->isa_oopptr() != NULL &&
2372 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
2373
2374 bool global_escapes = false;
2375 bool fields_escapes = false;
2376 if (!call_analyzer->is_arg_stack(k)) {
2377 // The argument global escapes, mark everything it could point to
2378 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2379 global_escapes = true;
2380 } else {
2381 if (!call_analyzer->is_arg_local(k)) {
2382 // The argument itself doesn't escape, but any fields might
2383 fields_escapes = true;
2384 }
2385 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
2386 copy_dependencies = true;
2387 }
2388
2389 for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2390 uint pt = j.elem;
2391 if (global_escapes) {
2392 // The argument global escapes, mark everything it could point to
2393 set_escape_state(pt, PointsToNode::GlobalEscape);
2394 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2395 } else {
2396 set_escape_state(pt, PointsToNode::ArgEscape);
2397 if (fields_escapes) {
2398 // The argument itself doesn't escape, but any fields might.
2399 // Use OffsetTop to indicate such case.
2400 add_edge_from_fields(pt, _phantom_object, Type::OffsetTop);
2401 }
2402 }
2403 }
2404 }
2405 }
2406 if (copy_dependencies)
2407 call_analyzer->copy_dependencies(_compile->dependencies());
2408 break;
2409 }
2410 }
2411
2412 default:
2413 // Fall-through here if not a Java method or no analyzer information
2414 // or some other type of call, assume the worst case: all arguments
2415 // globally escape.
2416 {
2417 // adjust escape state for outgoing arguments
2418 const TypeTuple * d = call->tf()->domain();
2419 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2420 const Type* at = d->field_at(i);
2421 if (at->isa_oopptr() != NULL) {
2422 Node *arg = call->in(i)->uncast();
2423 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2424 for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2425 uint pt = j.elem;
2426 set_escape_state(pt, PointsToNode::GlobalEscape);
2427 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2428 }
2429 }
2430 }
2431 }
2432 }
2433 }
2434 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
2435 CallNode *call = resproj->in(0)->as_Call();
2436 uint call_idx = call->_idx;
2437 uint resproj_idx = resproj->_idx;
2438
2439 switch (call->Opcode()) {
2440 case Op_Allocate:
2441 {
2442 Node *k = call->in(AllocateNode::KlassNode);
2443 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2444 assert(kt != NULL, "TypeKlassPtr required.");
2445 ciKlass* cik = kt->klass();
2446
2447 PointsToNode::EscapeState es;
2448 uint edge_to;
2449 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2450 !cik->is_instance_klass() || // StressReflectiveCode
2451 cik->as_instance_klass()->has_finalizer()) {
2452 es = PointsToNode::GlobalEscape;
2453 edge_to = _phantom_object; // Could not be worse
2454 } else {
2455 es = PointsToNode::NoEscape;
2456 edge_to = call_idx;
2457 assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
2458 }
2459 set_escape_state(call_idx, es);
2460 add_pointsto_edge(resproj_idx, edge_to);
2461 _processed.set(resproj_idx);
2462 break;
2463 }
2464
2465 case Op_AllocateArray:
2466 {
2467
2468 Node *k = call->in(AllocateNode::KlassNode);
2469 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2470 assert(kt != NULL, "TypeKlassPtr required.");
2471 ciKlass* cik = kt->klass();
2472
2473 PointsToNode::EscapeState es;
2474 uint edge_to;
2475 if (!cik->is_array_klass()) { // StressReflectiveCode
2476 es = PointsToNode::GlobalEscape;
2477 edge_to = _phantom_object;
2478 } else {
2479 es = PointsToNode::NoEscape;
2480 edge_to = call_idx;
2481 assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
2482 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2483 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2484 // Not scalar replaceable if the length is not constant or too big.
2485 ptnode_adr(call_idx)->set_scalar_replaceable(false);
2486 }
2487 }
2488 set_escape_state(call_idx, es);
2489 add_pointsto_edge(resproj_idx, edge_to);
2490 _processed.set(resproj_idx);
2491 break;
2492 }
2493
2494 case Op_CallStaticJava:
2495 // For a static call, we know exactly what method is being called.
2496 // Use bytecode estimator to record whether the call's return value escapes
2497 {
2498 bool done = true;
2499 const TypeTuple *r = call->tf()->range();
2500 const Type* ret_type = NULL;
2501
2502 if (r->cnt() > TypeFunc::Parms)
2503 ret_type = r->field_at(TypeFunc::Parms);
2504
2505 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2506 // _multianewarray functions return a TypeRawPtr.
2507 if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2508 _processed.set(resproj_idx);
2509 break; // doesn't return a pointer type
2510 }
2511 ciMethod *meth = call->as_CallJava()->method();
2512 const TypeTuple * d = call->tf()->domain();
2513 if (meth == NULL) {
2514 // not a Java method, assume global escape
2515 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2516 add_pointsto_edge(resproj_idx, _phantom_object);
2517 } else {
2518 BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2519 bool copy_dependencies = false;
2520
2521 if (call_analyzer->is_return_allocated()) {
2522 // Returns a newly allocated unescaped object, simply
2523 // update dependency information.
2524 // Mark it as NoEscape so that objects referenced by
2525 // it's fields will be marked as NoEscape at least.
2526 set_escape_state(call_idx, PointsToNode::NoEscape);
2527 ptnode_adr(call_idx)->set_scalar_replaceable(false);
2528 // Fields values are unknown
2529 add_edge_from_fields(call_idx, _phantom_object, Type::OffsetBot);
2530 add_pointsto_edge(resproj_idx, call_idx);
2531 copy_dependencies = true;
2532 } else {
2533 // determine whether any arguments are returned
2534 set_escape_state(call_idx, PointsToNode::ArgEscape);
2535 bool ret_arg = false;
2536 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2537 const Type* at = d->field_at(i);
2538 if (at->isa_oopptr() != NULL) {
2539 Node *arg = call->in(i)->uncast();
2540
2541 if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2542 ret_arg = true;
2543 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2544 if (arg_esp->node_type() == PointsToNode::UnknownType)
2545 done = false;
2546 else if (arg_esp->node_type() == PointsToNode::JavaObject)
2547 add_pointsto_edge(resproj_idx, arg->_idx);
2548 else
2549 add_deferred_edge(resproj_idx, arg->_idx);
2550 }
2551 }
2552 }
2553 if (done) {
2554 copy_dependencies = true;
2555 // is_return_local() is true when only arguments are returned.
2556 if (!ret_arg || !call_analyzer->is_return_local()) {
2557 // Returns unknown object.
2558 add_pointsto_edge(resproj_idx, _phantom_object);
2559 }
2560 }
2561 }
2562 if (copy_dependencies)
2563 call_analyzer->copy_dependencies(_compile->dependencies());
2564 }
2565 if (done)
2566 _processed.set(resproj_idx);
2567 break;
2568 }
2569
2570 default:
2571 // Some other type of call, assume the worst case that the
2572 // returned value, if any, globally escapes.
2573 {
2574 const TypeTuple *r = call->tf()->range();
2575 if (r->cnt() > TypeFunc::Parms) {
2576 const Type* ret_type = r->field_at(TypeFunc::Parms);
2577
2578 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2579 // _multianewarray functions return a TypeRawPtr.
2580 if (ret_type->isa_ptr() != NULL) {
2581 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2582 add_pointsto_edge(resproj_idx, _phantom_object);
2583 }
2584 }
2585 _processed.set(resproj_idx);
2586 }
2587 }
2588 }
2589
2590 // Populate Connection Graph with Ideal nodes and create simple
2591 // connection graph edges (do not need to check the node_type of inputs
2592 // or to call PointsTo() to walk the connection graph).
2593 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2594 if (_processed.test(n->_idx))
2595 return; // No need to redefine node's state.
2596
2597 if (n->is_Call()) {
2598 // Arguments to allocation and locking don't escape.
2599 if (n->is_Allocate()) {
2600 add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2601 record_for_optimizer(n);
2602 } else if (n->is_Lock() || n->is_Unlock()) {
2603 // Put Lock and Unlock nodes on IGVN worklist to process them during
2604 // the first IGVN optimization when escape information is still available.
2605 record_for_optimizer(n);
2606 _processed.set(n->_idx);
2607 } else {
2608 // Don't mark as processed since call's arguments have to be processed.
2609 PointsToNode::NodeType nt = PointsToNode::UnknownType;
2610 PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2611
2612 // Check if a call returns an object.
2613 const TypeTuple *r = n->as_Call()->tf()->range();
2614 if (r->cnt() > TypeFunc::Parms &&
2615 r->field_at(TypeFunc::Parms)->isa_ptr() &&
2616 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2617 nt = PointsToNode::JavaObject;
2618 if (!n->is_CallStaticJava()) {
2619 // Since the called mathod is statically unknown assume
2620 // the worst case that the returned value globally escapes.
2621 es = PointsToNode::GlobalEscape;
2622 }
2623 }
2624 add_node(n, nt, es, false);
2625 }
2626 return;
2627 }
2628
2629 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2630 // ThreadLocal has RawPrt type.
2631 switch (n->Opcode()) {
2632 case Op_AddP:
2633 {
2634 add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
2635 break;
2636 }
2637 case Op_CastX2P:
2638 { // "Unsafe" memory access.
2639 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2640 break;
2641 }
2642 case Op_CastPP:
2643 case Op_CheckCastPP:
2644 case Op_EncodeP:
2645 case Op_DecodeN:
2646 {
2647 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2648 int ti = n->in(1)->_idx;
2649 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2650 if (nt == PointsToNode::UnknownType) {
2651 _delayed_worklist.push(n); // Process it later.
2652 break;
2653 } else if (nt == PointsToNode::JavaObject) {
2654 add_pointsto_edge(n->_idx, ti);
2655 } else {
2656 add_deferred_edge(n->_idx, ti);
2657 }
2658 _processed.set(n->_idx);
2659 break;
2660 }
2661 case Op_ConP:
2662 {
2663 // assume all pointer constants globally escape except for null
2664 PointsToNode::EscapeState es;
2665 if (phase->type(n) == TypePtr::NULL_PTR)
2666 es = PointsToNode::NoEscape;
2667 else
2668 es = PointsToNode::GlobalEscape;
2669
2670 add_node(n, PointsToNode::JavaObject, es, true);
2671 break;
2672 }
2673 case Op_ConN:
2674 {
2675 // assume all narrow oop constants globally escape except for null
2676 PointsToNode::EscapeState es;
2677 if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2678 es = PointsToNode::NoEscape;
2679 else
2680 es = PointsToNode::GlobalEscape;
2681
2682 add_node(n, PointsToNode::JavaObject, es, true);
2683 break;
2684 }
2685 case Op_CreateEx:
2686 {
2687 // assume that all exception objects globally escape
2688 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2689 break;
2690 }
2691 case Op_LoadKlass:
2692 case Op_LoadNKlass:
2693 {
2694 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2695 break;
2696 }
2697 case Op_LoadP:
2698 case Op_LoadN:
2699 {
2700 const Type *t = phase->type(n);
2701 if (t->make_ptr() == NULL) {
2702 _processed.set(n->_idx);
2703 return;
2704 }
2705 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2706 break;
2707 }
2708 case Op_Parm:
2709 {
2710 _processed.set(n->_idx); // No need to redefine it state.
2711 uint con = n->as_Proj()->_con;
2712 if (con < TypeFunc::Parms)
2713 return;
2714 const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2715 if (t->isa_ptr() == NULL)
2716 return;
2717 // We have to assume all input parameters globally escape
2718 // (Note: passing 'false' since _processed is already set).
2719 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2720 break;
2721 }
2722 case Op_PartialSubtypeCheck:
2723 { // Produces Null or notNull and is used in CmpP.
2724 add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2725 break;
2726 }
2727 case Op_Phi:
2728 {
2729 const Type *t = n->as_Phi()->type();
2730 if (t->make_ptr() == NULL) {
2731 // nothing to do if not an oop or narrow oop
2732 _processed.set(n->_idx);
2733 return;
2734 }
2735 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2736 uint i;
2737 for (i = 1; i < n->req() ; i++) {
2738 Node* in = n->in(i);
2739 if (in == NULL)
2740 continue; // ignore NULL
2741 in = in->uncast();
2742 if (in->is_top() || in == n)
2743 continue; // ignore top or inputs which go back this node
2744 int ti = in->_idx;
2745 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2746 if (nt == PointsToNode::UnknownType) {
2747 break;
2748 } else if (nt == PointsToNode::JavaObject) {
2749 add_pointsto_edge(n->_idx, ti);
2750 } else {
2751 add_deferred_edge(n->_idx, ti);
2752 }
2753 }
2754 if (i >= n->req())
2755 _processed.set(n->_idx);
2756 else
2757 _delayed_worklist.push(n);
2758 break;
2759 }
2760 case Op_Proj:
2761 {
2762 // we are only interested in the oop result projection from a call
2763 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2764 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2765 assert(r->cnt() > TypeFunc::Parms, "sanity");
2766 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2767 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2768 int ti = n->in(0)->_idx;
2769 // The call may not be registered yet (since not all its inputs are registered)
2770 // if this is the projection from backbranch edge of Phi.
2771 if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2772 process_call_result(n->as_Proj(), phase);
2773 }
2774 if (!_processed.test(n->_idx)) {
2775 // The call's result may need to be processed later if the call
2776 // returns it's argument and the argument is not processed yet.
2777 _delayed_worklist.push(n);
2778 }
2779 break;
2780 }
2781 }
2782 _processed.set(n->_idx);
2783 break;
2784 }
2785 case Op_Return:
2786 {
2787 if( n->req() > TypeFunc::Parms &&
2788 phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2789 // Treat Return value as LocalVar with GlobalEscape escape state.
2790 add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2791 int ti = n->in(TypeFunc::Parms)->_idx;
2792 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2793 if (nt == PointsToNode::UnknownType) {
2794 _delayed_worklist.push(n); // Process it later.
2795 break;
2796 } else if (nt == PointsToNode::JavaObject) {
2797 add_pointsto_edge(n->_idx, ti);
2798 } else {
2799 add_deferred_edge(n->_idx, ti);
2800 }
2801 }
2802 _processed.set(n->_idx);
2803 break;
2804 }
2805 case Op_StoreP:
2806 case Op_StoreN:
2807 {
2808 const Type *adr_type = phase->type(n->in(MemNode::Address));
2809 adr_type = adr_type->make_ptr();
2810 if (adr_type->isa_oopptr()) {
2811 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2812 } else {
2813 Node* adr = n->in(MemNode::Address);
2814 if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2815 adr->in(AddPNode::Address)->is_Proj() &&
2816 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2817 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2818 // We are computing a raw address for a store captured
2819 // by an Initialize compute an appropriate address type.
2820 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2821 assert(offs != Type::OffsetBot, "offset must be a constant");
2822 } else {
2823 _processed.set(n->_idx);
2824 return;
2825 }
2826 }
2827 break;
2828 }
2829 case Op_StorePConditional:
2830 case Op_CompareAndSwapP:
2831 case Op_CompareAndSwapN:
2832 {
2833 const Type *adr_type = phase->type(n->in(MemNode::Address));
2834 adr_type = adr_type->make_ptr();
2835 if (adr_type->isa_oopptr()) {
2836 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2837 } else {
2838 _processed.set(n->_idx);
2839 return;
2840 }
2841 break;
2842 }
2843 case Op_AryEq:
2844 case Op_StrComp:
2845 case Op_StrEquals:
2846 case Op_StrIndexOf:
2847 {
2848 // char[] arrays passed to string intrinsics are not scalar replaceable.
2849 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2850 break;
2851 }
2852 case Op_ThreadLocal:
2853 {
2854 add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2855 break;
2856 }
2857 default:
2858 ;
2859 // nothing to do
2860 }
2861 return;
2862 }
2863
2864 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2865 uint n_idx = n->_idx;
2866 assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2867
2868 // Don't set processed bit for AddP, LoadP, StoreP since
2869 // they may need more then one pass to process.
2870 // Also don't mark as processed Call nodes since their
2871 // arguments may need more then one pass to process.
2872 if (_processed.test(n_idx))
2873 return; // No need to redefine node's state.
2874
2875 if (n->is_Call()) {
2876 CallNode *call = n->as_Call();
2877 process_call_arguments(call, phase);
2878 return;
2879 }
2880
2881 switch (n->Opcode()) {
2882 case Op_AddP:
2883 {
2884 Node *base = get_addp_base(n);
2885 int offset = address_offset(n, phase);
2886 // Create a field edge to this node from everything base could point to.
2887 for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
2888 uint pt = i.elem;
2889 add_field_edge(pt, n_idx, offset);
2890 }
2891 break;
2892 }
2893 case Op_CastX2P:
2894 {
2895 assert(false, "Op_CastX2P");
2896 break;
2897 }
2898 case Op_CastPP:
2899 case Op_CheckCastPP:
2900 case Op_EncodeP:
2901 case Op_DecodeN:
2902 {
2903 int ti = n->in(1)->_idx;
2904 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2905 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2906 add_pointsto_edge(n_idx, ti);
2907 } else {
2908 add_deferred_edge(n_idx, ti);
2909 }
2910 _processed.set(n_idx);
2911 break;
2912 }
2913 case Op_ConP:
2914 {
2915 assert(false, "Op_ConP");
2916 break;
2917 }
2918 case Op_ConN:
2919 {
2920 assert(false, "Op_ConN");
2921 break;
2922 }
2923 case Op_CreateEx:
2924 {
2925 assert(false, "Op_CreateEx");
2926 break;
2927 }
2928 case Op_LoadKlass:
2929 case Op_LoadNKlass:
2930 {
2931 assert(false, "Op_LoadKlass");
2932 break;
2933 }
2934 case Op_LoadP:
2935 case Op_LoadN:
2936 {
2937 const Type *t = phase->type(n);
2938 #ifdef ASSERT
2939 if (t->make_ptr() == NULL)
2940 assert(false, "Op_LoadP");
2941 #endif
2942
2943 Node* adr = n->in(MemNode::Address)->uncast();
2944 Node* adr_base;
2945 if (adr->is_AddP()) {
2946 adr_base = get_addp_base(adr);
2947 } else {
2948 adr_base = adr;
2949 }
2950
2951 // For everything "adr_base" could point to, create a deferred edge from
2952 // this node to each field with the same offset.
2953 int offset = address_offset(adr, phase);
2954 for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
2955 uint pt = i.elem;
2956 if (adr->is_AddP()) {
2957 // Add field edge if it is missing.
2958 add_field_edge(pt, adr->_idx, offset);
2959 }
2960 add_deferred_edge_to_fields(n_idx, pt, offset);
2961 }
2962 break;
2963 }
2964 case Op_Parm:
2965 {
2966 assert(false, "Op_Parm");
2967 break;
2968 }
2969 case Op_PartialSubtypeCheck:
2970 {
2971 assert(false, "Op_PartialSubtypeCheck");
2972 break;
2973 }
2974 case Op_Phi:
2975 {
2976 #ifdef ASSERT
2977 const Type *t = n->as_Phi()->type();
2978 if (t->make_ptr() == NULL)
2979 assert(false, "Op_Phi");
2980 #endif
2981 for (uint i = 1; i < n->req() ; i++) {
2982 Node* in = n->in(i);
2983 if (in == NULL)
2984 continue; // ignore NULL
2985 in = in->uncast();
2986 if (in->is_top() || in == n)
2987 continue; // ignore top or inputs which go back this node
2988 int ti = in->_idx;
2989 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2990 assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2991 if (nt == PointsToNode::JavaObject) {
2992 add_pointsto_edge(n_idx, ti);
2993 } else {
2994 add_deferred_edge(n_idx, ti);
2995 }
2996 }
2997 _processed.set(n_idx);
2998 break;
2999 }
3000 case Op_Proj:
3001 {
3002 // we are only interested in the oop result projection from a call
3003 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
3004 assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
3005 "all nodes should be registered");
3006 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
3007 assert(r->cnt() > TypeFunc::Parms, "sanity");
3008 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
3009 process_call_result(n->as_Proj(), phase);
3010 assert(_processed.test(n_idx), "all call results should be processed");
3011 break;
3012 }
3013 }
3014 assert(false, "Op_Proj");
3015 break;
3016 }
3017 case Op_Return:
3018 {
3019 #ifdef ASSERT
3020 if( n->req() <= TypeFunc::Parms ||
3021 !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
3022 assert(false, "Op_Return");
3023 }
3024 #endif
3025 int ti = n->in(TypeFunc::Parms)->_idx;
3026 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
3027 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
3028 add_pointsto_edge(n_idx, ti);
3029 } else {
3030 add_deferred_edge(n_idx, ti);
3031 }
3032 _processed.set(n_idx);
3033 break;
3034 }
3035 case Op_StoreP:
3036 case Op_StoreN:
3037 case Op_StorePConditional:
3038 case Op_CompareAndSwapP:
3039 case Op_CompareAndSwapN:
3040 {
3041 Node *adr = n->in(MemNode::Address);
3042 const Type *adr_type = phase->type(adr)->make_ptr();
3043 #ifdef ASSERT
3044 if (!adr_type->isa_oopptr())
3045 assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
3046 #endif
3047
3048 assert(adr->is_AddP(), "expecting an AddP");
3049 Node *adr_base = get_addp_base(adr);
3050 Node *val = n->in(MemNode::ValueIn)->uncast();
3051 int offset = address_offset(adr, phase);
3052 // For everything "adr_base" could point to, create a deferred edge
3053 // to "val" from each field with the same offset.
3054 for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
3055 uint pt = i.elem;
3056 // Add field edge if it is missing.
3057 add_field_edge(pt, adr->_idx, offset);
3058 add_edge_from_fields(pt, val->_idx, offset);
3059 }
3060 break;
3061 }
3062 case Op_AryEq:
3063 case Op_StrComp:
3064 case Op_StrEquals:
3065 case Op_StrIndexOf:
3066 {
3067 // char[] arrays passed to string intrinsic do not escape but
3068 // they are not scalar replaceable. Adjust escape state for them.
3069 // Start from in(2) edge since in(1) is memory edge.
3070 for (uint i = 2; i < n->req(); i++) {
3071 Node* adr = n->in(i)->uncast();
3072 const Type *at = phase->type(adr);
3073 if (!adr->is_top() && at->isa_ptr()) {
3074 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
3075 at->isa_ptr() != NULL, "expecting an Ptr");
3076 if (adr->is_AddP()) {
3077 adr = get_addp_base(adr);
3078 }
3079 // Mark as ArgEscape everything "adr" could point to.
3080 set_escape_state(adr->_idx, PointsToNode::ArgEscape);
3081 }
3082 }
3083 _processed.set(n_idx);
3084 break;
3085 }
3086 case Op_ThreadLocal:
3087 {
3088 assert(false, "Op_ThreadLocal");
3089 break;
3090 }
3091 default:
3092 // This method should be called only for EA specific nodes.
3093 ShouldNotReachHere();
3094 }
3095 }
3096
3097 #ifndef PRODUCT
3098 void ConnectionGraph::dump() {
3099 bool first = true;
3100
3101 uint size = nodes_size();
3102 for (uint ni = 0; ni < size; ni++) {
3103 PointsToNode *ptn = ptnode_adr(ni);
3104 PointsToNode::NodeType ptn_type = ptn->node_type();
3105
3106 if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
3107 continue;
3108 PointsToNode::EscapeState es = escape_state(ptn->_node);
3109 if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3110 if (first) {
3111 tty->cr();
3112 tty->print("======== Connection graph for ");
3113 _compile->method()->print_short_name();
3114 tty->cr();
3115 first = false;
3116 }
3117 tty->print("%6d ", ni);
3118 ptn->dump();
3119 // Print all locals which reference this allocation
3120 for (uint li = ni; li < size; li++) {
3121 PointsToNode *ptn_loc = ptnode_adr(li);
3122 PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
3123 if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
3124 ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
3125 ptnode_adr(li)->dump(false);
3126 }
3127 }
3128 if (Verbose) {
3129 // Print all fields which reference this allocation
3130 for (uint i = 0; i < ptn->edge_count(); i++) {
3131 uint ei = ptn->edge_target(i);
3132 ptnode_adr(ei)->dump(false);
3133 }
3134 }
3135 tty->cr();
3136 }
3137 }
3138 }
3139 #endif
|
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:
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
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");
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;
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);
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
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);
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);
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) {
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
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