1 /*
2 * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "opto/c2compiler.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/compile.hpp"
34 #include "opto/escape.hpp"
35 #include "opto/phaseX.hpp"
36 #include "opto/rootnode.hpp"
37
38 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
39 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
40 _in_worklist(C->comp_arena()),
41 _next_pidx(0),
42 _collecting(true),
43 _verify(false),
44 _compile(C),
45 _igvn(igvn),
46 _node_map(C->comp_arena()) {
47 // Add unknown java object.
48 add_java_object(C->top(), PointsToNode::GlobalEscape);
49 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
50 // Add ConP(#NULL) and ConN(#NULL) nodes.
51 Node* oop_null = igvn->zerocon(T_OBJECT);
52 assert(oop_null->_idx < nodes_size(), "should be created already");
53 add_java_object(oop_null, PointsToNode::NoEscape);
54 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
55 if (UseCompressedOops) {
56 Node* noop_null = igvn->zerocon(T_NARROWOOP);
57 assert(noop_null->_idx < nodes_size(), "should be created already");
58 map_ideal_node(noop_null, null_obj);
59 }
60 _pcmp_neq = NULL; // Should be initialized
61 _pcmp_eq = NULL;
62 }
63
64 bool ConnectionGraph::has_candidates(Compile *C) {
65 // EA brings benefits only when the code has allocations and/or locks which
66 // are represented by ideal Macro nodes.
67 int cnt = C->macro_count();
68 for (int i = 0; i < cnt; i++) {
69 Node *n = C->macro_node(i);
70 if (n->is_Allocate())
71 return true;
72 if (n->is_Lock()) {
73 Node* obj = n->as_Lock()->obj_node()->uncast();
74 if (!(obj->is_Parm() || obj->is_Con()))
75 return true;
76 }
77 if (n->is_CallStaticJava() &&
78 n->as_CallStaticJava()->is_boxing_method()) {
79 return true;
80 }
81 }
82 return false;
83 }
84
85 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
86 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
87 ResourceMark rm;
88
89 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
90 // to create space for them in ConnectionGraph::_nodes[].
91 Node* oop_null = igvn->zerocon(T_OBJECT);
92 Node* noop_null = igvn->zerocon(T_NARROWOOP);
93 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
94 // Perform escape analysis
95 if (congraph->compute_escape()) {
96 // There are non escaping objects.
97 C->set_congraph(congraph);
98 }
99 // Cleanup.
100 if (oop_null->outcnt() == 0)
101 igvn->hash_delete(oop_null);
102 if (noop_null->outcnt() == 0)
103 igvn->hash_delete(noop_null);
104 }
105
106 bool ConnectionGraph::compute_escape() {
107 Compile* C = _compile;
108 PhaseGVN* igvn = _igvn;
109
110 // Worklists used by EA.
111 Unique_Node_List delayed_worklist;
112 GrowableArray<Node*> alloc_worklist;
113 GrowableArray<Node*> ptr_cmp_worklist;
114 GrowableArray<Node*> storestore_worklist;
115 GrowableArray<PointsToNode*> ptnodes_worklist;
116 GrowableArray<JavaObjectNode*> java_objects_worklist;
117 GrowableArray<JavaObjectNode*> non_escaped_worklist;
118 GrowableArray<FieldNode*> oop_fields_worklist;
119 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
120
121 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
122
123 // 1. Populate Connection Graph (CG) with PointsTo nodes.
124 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
125 // Initialize worklist
126 if (C->root() != NULL) {
127 ideal_nodes.push(C->root());
128 }
129 // Processed ideal nodes are unique on ideal_nodes list
130 // but several ideal nodes are mapped to the phantom_obj.
131 // To avoid duplicated entries on the following worklists
132 // add the phantom_obj only once to them.
133 ptnodes_worklist.append(phantom_obj);
134 java_objects_worklist.append(phantom_obj);
135 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
136 Node* n = ideal_nodes.at(next);
137 // Create PointsTo nodes and add them to Connection Graph. Called
138 // only once per ideal node since ideal_nodes is Unique_Node list.
139 add_node_to_connection_graph(n, &delayed_worklist);
140 PointsToNode* ptn = ptnode_adr(n->_idx);
141 if (ptn != NULL && ptn != phantom_obj) {
142 ptnodes_worklist.append(ptn);
143 if (ptn->is_JavaObject()) {
144 java_objects_worklist.append(ptn->as_JavaObject());
145 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
146 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
147 // Only allocations and java static calls results are interesting.
148 non_escaped_worklist.append(ptn->as_JavaObject());
149 }
150 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
151 oop_fields_worklist.append(ptn->as_Field());
152 }
153 }
154 if (n->is_MergeMem()) {
155 // Collect all MergeMem nodes to add memory slices for
156 // scalar replaceable objects in split_unique_types().
157 _mergemem_worklist.append(n->as_MergeMem());
158 } else if (OptimizePtrCompare && n->is_Cmp() &&
159 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
160 // Collect compare pointers nodes.
161 ptr_cmp_worklist.append(n);
162 } else if (n->is_MemBarStoreStore()) {
163 // Collect all MemBarStoreStore nodes so that depending on the
164 // escape status of the associated Allocate node some of them
165 // may be eliminated.
166 storestore_worklist.append(n);
167 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
168 (n->req() > MemBarNode::Precedent)) {
169 record_for_optimizer(n);
170 #ifdef ASSERT
171 } else if (n->is_AddP()) {
172 // Collect address nodes for graph verification.
173 addp_worklist.append(n);
174 #endif
175 }
176 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
177 Node* m = n->fast_out(i); // Get user
178 ideal_nodes.push(m);
179 }
180 }
181 if (non_escaped_worklist.length() == 0) {
182 _collecting = false;
183 return false; // Nothing to do.
184 }
185 // Add final simple edges to graph.
186 while(delayed_worklist.size() > 0) {
187 Node* n = delayed_worklist.pop();
188 add_final_edges(n);
189 }
190 int ptnodes_length = ptnodes_worklist.length();
191
192 #ifdef ASSERT
193 if (VerifyConnectionGraph) {
194 // Verify that no new simple edges could be created and all
195 // local vars has edges.
196 _verify = true;
197 for (int next = 0; next < ptnodes_length; ++next) {
198 PointsToNode* ptn = ptnodes_worklist.at(next);
199 add_final_edges(ptn->ideal_node());
200 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
201 ptn->dump();
202 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
203 }
204 }
205 _verify = false;
206 }
207 #endif
208 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
209 // processing, calls to CI to resolve symbols (types, fields, methods)
210 // referenced in bytecode. During symbol resolution VM may throw
211 // an exception which CI cleans and converts to compilation failure.
212 if (C->failing()) return false;
213
214 // 2. Finish Graph construction by propagating references to all
215 // java objects through graph.
216 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
217 java_objects_worklist, oop_fields_worklist)) {
218 // All objects escaped or hit time or iterations limits.
219 _collecting = false;
220 return false;
221 }
222
223 // 3. Adjust scalar_replaceable state of nonescaping objects and push
224 // scalar replaceable allocations on alloc_worklist for processing
225 // in split_unique_types().
226 int non_escaped_length = non_escaped_worklist.length();
227 for (int next = 0; next < non_escaped_length; next++) {
228 JavaObjectNode* ptn = non_escaped_worklist.at(next);
229 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
230 Node* n = ptn->ideal_node();
231 if (n->is_Allocate()) {
232 n->as_Allocate()->_is_non_escaping = noescape;
233 }
234 if (n->is_CallStaticJava()) {
235 n->as_CallStaticJava()->_is_non_escaping = noescape;
236 }
237 if (noescape && ptn->scalar_replaceable()) {
238 adjust_scalar_replaceable_state(ptn);
239 if (ptn->scalar_replaceable()) {
240 alloc_worklist.append(ptn->ideal_node());
241 }
242 }
243 }
244
245 #ifdef ASSERT
246 if (VerifyConnectionGraph) {
247 // Verify that graph is complete - no new edges could be added or needed.
248 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
249 java_objects_worklist, addp_worklist);
250 }
251 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
252 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
253 null_obj->edge_count() == 0 &&
254 !null_obj->arraycopy_src() &&
255 !null_obj->arraycopy_dst(), "sanity");
256 #endif
257
258 _collecting = false;
259
260 } // TracePhase t3("connectionGraph")
261
262 // 4. Optimize ideal graph based on EA information.
263 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
264 if (has_non_escaping_obj) {
265 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
266 }
267
268 #ifndef PRODUCT
269 if (PrintEscapeAnalysis) {
270 dump(ptnodes_worklist); // Dump ConnectionGraph
271 }
272 #endif
273
274 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
275 #ifdef ASSERT
276 if (VerifyConnectionGraph) {
277 int alloc_length = alloc_worklist.length();
278 for (int next = 0; next < alloc_length; ++next) {
279 Node* n = alloc_worklist.at(next);
280 PointsToNode* ptn = ptnode_adr(n->_idx);
281 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
282 }
283 }
284 #endif
285
286 // 5. Separate memory graph for scalar replaceable allcations.
287 if (has_scalar_replaceable_candidates &&
288 C->AliasLevel() >= 3 && EliminateAllocations) {
289 // Now use the escape information to create unique types for
290 // scalar replaceable objects.
291 split_unique_types(alloc_worklist);
292 if (C->failing()) return false;
293 C->print_method(PHASE_AFTER_EA, 2);
294
295 #ifdef ASSERT
296 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
297 tty->print("=== No allocations eliminated for ");
298 C->method()->print_short_name();
299 if(!EliminateAllocations) {
300 tty->print(" since EliminateAllocations is off ===");
301 } else if(!has_scalar_replaceable_candidates) {
302 tty->print(" since there are no scalar replaceable candidates ===");
303 } else if(C->AliasLevel() < 3) {
304 tty->print(" since AliasLevel < 3 ===");
305 }
306 tty->cr();
307 #endif
308 }
309 return has_non_escaping_obj;
310 }
311
312 // Utility function for nodes that load an object
313 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
314 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
315 // ThreadLocal has RawPtr type.
316 const Type* t = _igvn->type(n);
317 if (t->make_ptr() != NULL) {
318 Node* adr = n->in(MemNode::Address);
319 #ifdef ASSERT
320 if (!adr->is_AddP()) {
321 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
322 } else {
323 assert((ptnode_adr(adr->_idx) == NULL ||
324 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
325 }
326 #endif
327 add_local_var_and_edge(n, PointsToNode::NoEscape,
328 adr, delayed_worklist);
329 }
330 }
331
332 // Populate Connection Graph with PointsTo nodes and create simple
333 // connection graph edges.
334 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
335 assert(!_verify, "this method sould not be called for verification");
336 PhaseGVN* igvn = _igvn;
337 uint n_idx = n->_idx;
338 PointsToNode* n_ptn = ptnode_adr(n_idx);
339 if (n_ptn != NULL)
340 return; // No need to redefine PointsTo node during first iteration.
341
342 if (n->is_Call()) {
343 // Arguments to allocation and locking don't escape.
344 if (n->is_AbstractLock()) {
345 // Put Lock and Unlock nodes on IGVN worklist to process them during
346 // first IGVN optimization when escape information is still available.
347 record_for_optimizer(n);
348 } else if (n->is_Allocate()) {
349 add_call_node(n->as_Call());
350 record_for_optimizer(n);
351 } else {
352 if (n->is_CallStaticJava()) {
353 const char* name = n->as_CallStaticJava()->_name;
354 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
355 return; // Skip uncommon traps
356 }
357 // Don't mark as processed since call's arguments have to be processed.
358 delayed_worklist->push(n);
359 // Check if a call returns an object.
360 if ((n->as_Call()->returns_pointer() &&
361 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
362 (n->is_CallStaticJava() &&
363 n->as_CallStaticJava()->is_boxing_method())) {
364 add_call_node(n->as_Call());
365 }
366 }
367 return;
368 }
369 // Put this check here to process call arguments since some call nodes
370 // point to phantom_obj.
371 if (n_ptn == phantom_obj || n_ptn == null_obj)
372 return; // Skip predefined nodes.
373
374 int opcode = n->Opcode();
375 switch (opcode) {
376 case Op_AddP: {
377 Node* base = get_addp_base(n);
378 PointsToNode* ptn_base = ptnode_adr(base->_idx);
379 // Field nodes are created for all field types. They are used in
380 // adjust_scalar_replaceable_state() and split_unique_types().
381 // Note, non-oop fields will have only base edges in Connection
382 // Graph because such fields are not used for oop loads and stores.
383 int offset = address_offset(n, igvn);
384 add_field(n, PointsToNode::NoEscape, offset);
385 if (ptn_base == NULL) {
386 delayed_worklist->push(n); // Process it later.
387 } else {
388 n_ptn = ptnode_adr(n_idx);
389 add_base(n_ptn->as_Field(), ptn_base);
390 }
391 break;
392 }
393 case Op_CastX2P: {
394 map_ideal_node(n, phantom_obj);
395 break;
396 }
397 case Op_CastPP:
398 case Op_CheckCastPP:
399 case Op_EncodeP:
400 case Op_DecodeN:
401 case Op_EncodePKlass:
402 case Op_DecodeNKlass: {
403 add_local_var_and_edge(n, PointsToNode::NoEscape,
404 n->in(1), delayed_worklist);
405 break;
406 }
407 case Op_CMoveP: {
408 add_local_var(n, PointsToNode::NoEscape);
409 // Do not add edges during first iteration because some could be
410 // not defined yet.
411 delayed_worklist->push(n);
412 break;
413 }
414 case Op_ConP:
415 case Op_ConN:
416 case Op_ConNKlass: {
417 // assume all oop constants globally escape except for null
418 PointsToNode::EscapeState es;
419 const Type* t = igvn->type(n);
420 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
421 es = PointsToNode::NoEscape;
422 } else {
423 es = PointsToNode::GlobalEscape;
424 }
425 add_java_object(n, es);
426 break;
427 }
428 case Op_CreateEx: {
429 // assume that all exception objects globally escape
430 map_ideal_node(n, phantom_obj);
431 break;
432 }
433 case Op_LoadKlass:
434 case Op_LoadNKlass: {
435 // Unknown class is loaded
436 map_ideal_node(n, phantom_obj);
437 break;
438 }
439 case Op_LoadP:
440 case Op_LoadN:
441 case Op_LoadPLocked: {
442 add_objload_to_connection_graph(n, delayed_worklist);
443 break;
444 }
445 case Op_Parm: {
446 map_ideal_node(n, phantom_obj);
447 break;
448 }
449 case Op_PartialSubtypeCheck: {
450 // Produces Null or notNull and is used in only in CmpP so
451 // phantom_obj could be used.
452 map_ideal_node(n, phantom_obj); // Result is unknown
453 break;
454 }
455 case Op_Phi: {
456 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
457 // ThreadLocal has RawPtr type.
458 const Type* t = n->as_Phi()->type();
459 if (t->make_ptr() != NULL) {
460 add_local_var(n, PointsToNode::NoEscape);
461 // Do not add edges during first iteration because some could be
462 // not defined yet.
463 delayed_worklist->push(n);
464 }
465 break;
466 }
467 case Op_Proj: {
468 // we are only interested in the oop result projection from a call
469 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
470 n->in(0)->as_Call()->returns_pointer()) {
471 add_local_var_and_edge(n, PointsToNode::NoEscape,
472 n->in(0), delayed_worklist);
473 }
474 break;
475 }
476 case Op_Rethrow: // Exception object escapes
477 case Op_Return: {
478 if (n->req() > TypeFunc::Parms &&
479 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
480 // Treat Return value as LocalVar with GlobalEscape escape state.
481 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
482 n->in(TypeFunc::Parms), delayed_worklist);
483 }
484 break;
485 }
486 case Op_GetAndSetP:
487 case Op_GetAndSetN: {
488 add_objload_to_connection_graph(n, delayed_worklist);
489 // fallthrough
490 }
491 case Op_StoreP:
492 case Op_StoreN:
493 case Op_StoreNKlass:
494 case Op_StorePConditional:
495 case Op_CompareAndSwapP:
496 case Op_CompareAndSwapN: {
497 Node* adr = n->in(MemNode::Address);
498 const Type *adr_type = igvn->type(adr);
499 adr_type = adr_type->make_ptr();
500 if (adr_type == NULL) {
501 break; // skip dead nodes
502 }
503 if (adr_type->isa_oopptr() ||
504 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
505 (adr_type == TypeRawPtr::NOTNULL &&
506 adr->in(AddPNode::Address)->is_Proj() &&
507 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
508 delayed_worklist->push(n); // Process it later.
509 #ifdef ASSERT
510 assert(adr->is_AddP(), "expecting an AddP");
511 if (adr_type == TypeRawPtr::NOTNULL) {
512 // Verify a raw address for a store captured by Initialize node.
513 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
514 assert(offs != Type::OffsetBot, "offset must be a constant");
515 }
516 #endif
517 } else {
518 // Ignore copy the displaced header to the BoxNode (OSR compilation).
519 if (adr->is_BoxLock())
520 break;
521 // Stored value escapes in unsafe access.
522 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
523 // Pointer stores in G1 barriers looks like unsafe access.
524 // Ignore such stores to be able scalar replace non-escaping
525 // allocations.
526 if (UseG1GC && adr->is_AddP()) {
527 Node* base = get_addp_base(adr);
528 if (base->Opcode() == Op_LoadP &&
529 base->in(MemNode::Address)->is_AddP()) {
530 adr = base->in(MemNode::Address);
531 Node* tls = get_addp_base(adr);
532 if (tls->Opcode() == Op_ThreadLocal) {
533 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
534 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
535 PtrQueue::byte_offset_of_buf())) {
536 break; // G1 pre barier previous oop value store.
537 }
538 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
539 PtrQueue::byte_offset_of_buf())) {
540 break; // G1 post barier card address store.
541 }
542 }
543 }
544 }
545 delayed_worklist->push(n); // Process unsafe access later.
546 break;
547 }
548 #ifdef ASSERT
549 n->dump(1);
550 assert(false, "not unsafe or G1 barrier raw StoreP");
551 #endif
552 }
553 break;
554 }
555 case Op_AryEq:
556 case Op_StrComp:
557 case Op_StrEquals:
558 case Op_StrIndexOf:
559 case Op_EncodeISOArray: {
560 add_local_var(n, PointsToNode::ArgEscape);
561 delayed_worklist->push(n); // Process it later.
562 break;
563 }
564 case Op_ThreadLocal: {
565 add_java_object(n, PointsToNode::ArgEscape);
566 break;
567 }
568 default:
569 ; // Do nothing for nodes not related to EA.
570 }
571 return;
572 }
573
574 #ifdef ASSERT
575 #define ELSE_FAIL(name) \
576 /* Should not be called for not pointer type. */ \
577 n->dump(1); \
578 assert(false, name); \
579 break;
580 #else
581 #define ELSE_FAIL(name) \
582 break;
583 #endif
584
585 // Add final simple edges to graph.
586 void ConnectionGraph::add_final_edges(Node *n) {
587 PointsToNode* n_ptn = ptnode_adr(n->_idx);
588 #ifdef ASSERT
589 if (_verify && n_ptn->is_JavaObject())
590 return; // This method does not change graph for JavaObject.
591 #endif
592
593 if (n->is_Call()) {
594 process_call_arguments(n->as_Call());
595 return;
596 }
597 assert(n->is_Store() || n->is_LoadStore() ||
598 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
599 "node should be registered already");
600 int opcode = n->Opcode();
601 switch (opcode) {
602 case Op_AddP: {
603 Node* base = get_addp_base(n);
604 PointsToNode* ptn_base = ptnode_adr(base->_idx);
605 assert(ptn_base != NULL, "field's base should be registered");
606 add_base(n_ptn->as_Field(), ptn_base);
607 break;
608 }
609 case Op_CastPP:
610 case Op_CheckCastPP:
611 case Op_EncodeP:
612 case Op_DecodeN:
613 case Op_EncodePKlass:
614 case Op_DecodeNKlass: {
615 add_local_var_and_edge(n, PointsToNode::NoEscape,
616 n->in(1), NULL);
617 break;
618 }
619 case Op_CMoveP: {
620 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
621 Node* in = n->in(i);
622 if (in == NULL)
623 continue; // ignore NULL
624 Node* uncast_in = in->uncast();
625 if (uncast_in->is_top() || uncast_in == n)
626 continue; // ignore top or inputs which go back this node
627 PointsToNode* ptn = ptnode_adr(in->_idx);
628 assert(ptn != NULL, "node should be registered");
629 add_edge(n_ptn, ptn);
630 }
631 break;
632 }
633 case Op_LoadP:
634 case Op_LoadN:
635 case Op_LoadPLocked: {
636 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
637 // ThreadLocal has RawPtr type.
638 const Type* t = _igvn->type(n);
639 if (t->make_ptr() != NULL) {
640 Node* adr = n->in(MemNode::Address);
641 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
642 break;
643 }
644 ELSE_FAIL("Op_LoadP");
645 }
646 case Op_Phi: {
647 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
648 // ThreadLocal has RawPtr type.
649 const Type* t = n->as_Phi()->type();
650 if (t->make_ptr() != NULL) {
651 for (uint i = 1; i < n->req(); i++) {
652 Node* in = n->in(i);
653 if (in == NULL)
654 continue; // ignore NULL
655 Node* uncast_in = in->uncast();
656 if (uncast_in->is_top() || uncast_in == n)
657 continue; // ignore top or inputs which go back this node
658 PointsToNode* ptn = ptnode_adr(in->_idx);
659 assert(ptn != NULL, "node should be registered");
660 add_edge(n_ptn, ptn);
661 }
662 break;
663 }
664 ELSE_FAIL("Op_Phi");
665 }
666 case Op_Proj: {
667 // we are only interested in the oop result projection from a call
668 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
669 n->in(0)->as_Call()->returns_pointer()) {
670 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
671 break;
672 }
673 ELSE_FAIL("Op_Proj");
674 }
675 case Op_Rethrow: // Exception object escapes
676 case Op_Return: {
677 if (n->req() > TypeFunc::Parms &&
678 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
679 // Treat Return value as LocalVar with GlobalEscape escape state.
680 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
681 n->in(TypeFunc::Parms), NULL);
682 break;
683 }
684 ELSE_FAIL("Op_Return");
685 }
686 case Op_StoreP:
687 case Op_StoreN:
688 case Op_StoreNKlass:
689 case Op_StorePConditional:
690 case Op_CompareAndSwapP:
691 case Op_CompareAndSwapN:
692 case Op_GetAndSetP:
693 case Op_GetAndSetN: {
694 Node* adr = n->in(MemNode::Address);
695 const Type *adr_type = _igvn->type(adr);
696 adr_type = adr_type->make_ptr();
697 #ifdef ASSERT
698 if (adr_type == NULL) {
699 n->dump(1);
700 assert(adr_type != NULL, "dead node should not be on list");
701 break;
702 }
703 #endif
704 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
705 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
706 }
707 if (adr_type->isa_oopptr() ||
708 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
709 (adr_type == TypeRawPtr::NOTNULL &&
710 adr->in(AddPNode::Address)->is_Proj() &&
711 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
712 // Point Address to Value
713 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
714 assert(adr_ptn != NULL &&
715 adr_ptn->as_Field()->is_oop(), "node should be registered");
716 Node *val = n->in(MemNode::ValueIn);
717 PointsToNode* ptn = ptnode_adr(val->_idx);
718 assert(ptn != NULL, "node should be registered");
719 add_edge(adr_ptn, ptn);
720 break;
721 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
722 // Stored value escapes in unsafe access.
723 Node *val = n->in(MemNode::ValueIn);
724 PointsToNode* ptn = ptnode_adr(val->_idx);
725 assert(ptn != NULL, "node should be registered");
726 set_escape_state(ptn, PointsToNode::GlobalEscape);
727 // Add edge to object for unsafe access with offset.
728 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
729 assert(adr_ptn != NULL, "node should be registered");
730 if (adr_ptn->is_Field()) {
731 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
732 add_edge(adr_ptn, ptn);
733 }
734 break;
735 }
736 ELSE_FAIL("Op_StoreP");
737 }
738 case Op_AryEq:
739 case Op_StrComp:
740 case Op_StrEquals:
741 case Op_StrIndexOf:
742 case Op_EncodeISOArray: {
743 // char[] arrays passed to string intrinsic do not escape but
744 // they are not scalar replaceable. Adjust escape state for them.
745 // Start from in(2) edge since in(1) is memory edge.
746 for (uint i = 2; i < n->req(); i++) {
747 Node* adr = n->in(i);
748 const Type* at = _igvn->type(adr);
749 if (!adr->is_top() && at->isa_ptr()) {
750 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
751 at->isa_ptr() != NULL, "expecting a pointer");
752 if (adr->is_AddP()) {
753 adr = get_addp_base(adr);
754 }
755 PointsToNode* ptn = ptnode_adr(adr->_idx);
756 assert(ptn != NULL, "node should be registered");
757 add_edge(n_ptn, ptn);
758 }
759 }
760 break;
761 }
762 default: {
763 // This method should be called only for EA specific nodes which may
764 // miss some edges when they were created.
765 #ifdef ASSERT
766 n->dump(1);
767 #endif
768 guarantee(false, "unknown node");
769 }
770 }
771 return;
772 }
773
774 void ConnectionGraph::add_call_node(CallNode* call) {
775 assert(call->returns_pointer(), "only for call which returns pointer");
776 uint call_idx = call->_idx;
777 if (call->is_Allocate()) {
778 Node* k = call->in(AllocateNode::KlassNode);
779 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
780 assert(kt != NULL, "TypeKlassPtr required.");
781 ciKlass* cik = kt->klass();
782 PointsToNode::EscapeState es = PointsToNode::NoEscape;
783 bool scalar_replaceable = true;
784 if (call->is_AllocateArray()) {
785 if (!cik->is_array_klass()) { // StressReflectiveCode
786 es = PointsToNode::GlobalEscape;
787 } else {
788 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
789 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
790 // Not scalar replaceable if the length is not constant or too big.
791 scalar_replaceable = false;
792 }
793 }
794 } else { // Allocate instance
795 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
796 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
797 !cik->is_instance_klass() || // StressReflectiveCode
798 cik->as_instance_klass()->has_finalizer()) {
799 es = PointsToNode::GlobalEscape;
800 }
801 }
802 add_java_object(call, es);
803 PointsToNode* ptn = ptnode_adr(call_idx);
804 if (!scalar_replaceable && ptn->scalar_replaceable()) {
805 ptn->set_scalar_replaceable(false);
806 }
807 } else if (call->is_CallStaticJava()) {
808 // Call nodes could be different types:
809 //
810 // 1. CallDynamicJavaNode (what happened during call is unknown):
811 //
812 // - mapped to GlobalEscape JavaObject node if oop is returned;
813 //
814 // - all oop arguments are escaping globally;
815 //
816 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
817 //
818 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
819 //
820 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
821 // - mapped to NoEscape JavaObject node if non-escaping object allocated
822 // during call is returned;
823 // - mapped to ArgEscape LocalVar node pointed to object arguments
824 // which are returned and does not escape during call;
825 //
826 // - oop arguments escaping status is defined by bytecode analysis;
827 //
828 // For a static call, we know exactly what method is being called.
829 // Use bytecode estimator to record whether the call's return value escapes.
830 ciMethod* meth = call->as_CallJava()->method();
831 if (meth == NULL) {
832 const char* name = call->as_CallStaticJava()->_name;
833 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
834 // Returns a newly allocated unescaped object.
835 add_java_object(call, PointsToNode::NoEscape);
836 ptnode_adr(call_idx)->set_scalar_replaceable(false);
837 } else if (meth->is_boxing_method()) {
838 // Returns boxing object
839 PointsToNode::EscapeState es;
840 vmIntrinsics::ID intr = meth->intrinsic_id();
841 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
842 // It does not escape if object is always allocated.
843 es = PointsToNode::NoEscape;
844 } else {
845 // It escapes globally if object could be loaded from cache.
846 es = PointsToNode::GlobalEscape;
847 }
848 add_java_object(call, es);
849 } else {
850 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
851 call_analyzer->copy_dependencies(_compile->dependencies());
852 if (call_analyzer->is_return_allocated()) {
853 // Returns a newly allocated unescaped object, simply
854 // update dependency information.
855 // Mark it as NoEscape so that objects referenced by
856 // it's fields will be marked as NoEscape at least.
857 add_java_object(call, PointsToNode::NoEscape);
858 ptnode_adr(call_idx)->set_scalar_replaceable(false);
859 } else {
860 // Determine whether any arguments are returned.
861 const TypeTuple* d = call->tf()->domain();
862 bool ret_arg = false;
863 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
864 if (d->field_at(i)->isa_ptr() != NULL &&
865 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
866 ret_arg = true;
867 break;
868 }
869 }
870 if (ret_arg) {
871 add_local_var(call, PointsToNode::ArgEscape);
872 } else {
873 // Returns unknown object.
874 map_ideal_node(call, phantom_obj);
875 }
876 }
877 }
878 } else {
879 // An other type of call, assume the worst case:
880 // returned value is unknown and globally escapes.
881 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
882 map_ideal_node(call, phantom_obj);
883 }
884 }
885
886 void ConnectionGraph::process_call_arguments(CallNode *call) {
887 bool is_arraycopy = false;
888 switch (call->Opcode()) {
889 #ifdef ASSERT
890 case Op_Allocate:
891 case Op_AllocateArray:
892 case Op_Lock:
893 case Op_Unlock:
894 assert(false, "should be done already");
895 break;
896 #endif
897 case Op_CallLeafNoFP:
898 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
899 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
900 // fall through
901 case Op_CallLeaf: {
902 // Stub calls, objects do not escape but they are not scale replaceable.
903 // Adjust escape state for outgoing arguments.
904 const TypeTuple * d = call->tf()->domain();
905 bool src_has_oops = false;
906 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
907 const Type* at = d->field_at(i);
908 Node *arg = call->in(i);
909 const Type *aat = _igvn->type(arg);
910 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
911 continue;
912 if (arg->is_AddP()) {
913 //
914 // The inline_native_clone() case when the arraycopy stub is called
915 // after the allocation before Initialize and CheckCastPP nodes.
916 // Or normal arraycopy for object arrays case.
917 //
918 // Set AddP's base (Allocate) as not scalar replaceable since
919 // pointer to the base (with offset) is passed as argument.
920 //
921 arg = get_addp_base(arg);
922 }
923 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
924 assert(arg_ptn != NULL, "should be registered");
925 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
926 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
927 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
928 aat->isa_ptr() != NULL, "expecting an Ptr");
929 bool arg_has_oops = aat->isa_oopptr() &&
930 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
931 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
932 if (i == TypeFunc::Parms) {
933 src_has_oops = arg_has_oops;
934 }
935 //
936 // src or dst could be j.l.Object when other is basic type array:
937 //
938 // arraycopy(char[],0,Object*,0,size);
939 // arraycopy(Object*,0,char[],0,size);
940 //
941 // Don't add edges in such cases.
942 //
943 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
944 arg_has_oops && (i > TypeFunc::Parms);
945 #ifdef ASSERT
946 if (!(is_arraycopy ||
947 (call->as_CallLeaf()->_name != NULL &&
948 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
949 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
950 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
951 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
952 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
953 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
954 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
955 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
956 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
957 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
958 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
959 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
960 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
961 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
962 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
963 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
964 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
965 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0)
966 ))) {
967 call->dump();
968 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
969 }
970 #endif
971 // Always process arraycopy's destination object since
972 // we need to add all possible edges to references in
973 // source object.
974 if (arg_esc >= PointsToNode::ArgEscape &&
975 !arg_is_arraycopy_dest) {
976 continue;
977 }
978 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
979 if (arg_is_arraycopy_dest) {
980 Node* src = call->in(TypeFunc::Parms);
981 if (src->is_AddP()) {
982 src = get_addp_base(src);
983 }
984 PointsToNode* src_ptn = ptnode_adr(src->_idx);
985 assert(src_ptn != NULL, "should be registered");
986 if (arg_ptn != src_ptn) {
987 // Special arraycopy edge:
988 // A destination object's field can't have the source object
989 // as base since objects escape states are not related.
990 // Only escape state of destination object's fields affects
991 // escape state of fields in source object.
992 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
993 }
994 }
995 }
996 }
997 break;
998 }
999 case Op_CallStaticJava: {
1000 // For a static call, we know exactly what method is being called.
1001 // Use bytecode estimator to record the call's escape affects
1002 #ifdef ASSERT
1003 const char* name = call->as_CallStaticJava()->_name;
1004 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1005 #endif
1006 ciMethod* meth = call->as_CallJava()->method();
1007 if ((meth != NULL) && meth->is_boxing_method()) {
1008 break; // Boxing methods do not modify any oops.
1009 }
1010 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1011 // fall-through if not a Java method or no analyzer information
1012 if (call_analyzer != NULL) {
1013 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1014 const TypeTuple* d = call->tf()->domain();
1015 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1016 const Type* at = d->field_at(i);
1017 int k = i - TypeFunc::Parms;
1018 Node* arg = call->in(i);
1019 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1020 if (at->isa_ptr() != NULL &&
1021 call_analyzer->is_arg_returned(k)) {
1022 // The call returns arguments.
1023 if (call_ptn != NULL) { // Is call's result used?
1024 assert(call_ptn->is_LocalVar(), "node should be registered");
1025 assert(arg_ptn != NULL, "node should be registered");
1026 add_edge(call_ptn, arg_ptn);
1027 }
1028 }
1029 if (at->isa_oopptr() != NULL &&
1030 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1031 if (!call_analyzer->is_arg_stack(k)) {
1032 // The argument global escapes
1033 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1034 } else {
1035 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1036 if (!call_analyzer->is_arg_local(k)) {
1037 // The argument itself doesn't escape, but any fields might
1038 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1039 }
1040 }
1041 }
1042 }
1043 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1044 // The call returns arguments.
1045 assert(call_ptn->edge_count() > 0, "sanity");
1046 if (!call_analyzer->is_return_local()) {
1047 // Returns also unknown object.
1048 add_edge(call_ptn, phantom_obj);
1049 }
1050 }
1051 break;
1052 }
1053 }
1054 default: {
1055 // Fall-through here if not a Java method or no analyzer information
1056 // or some other type of call, assume the worst case: all arguments
1057 // globally escape.
1058 const TypeTuple* d = call->tf()->domain();
1059 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1060 const Type* at = d->field_at(i);
1061 if (at->isa_oopptr() != NULL) {
1062 Node* arg = call->in(i);
1063 if (arg->is_AddP()) {
1064 arg = get_addp_base(arg);
1065 }
1066 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1067 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1068 }
1069 }
1070 }
1071 }
1072 }
1073
1074
1075 // Finish Graph construction.
1076 bool ConnectionGraph::complete_connection_graph(
1077 GrowableArray<PointsToNode*>& ptnodes_worklist,
1078 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1079 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1080 GrowableArray<FieldNode*>& oop_fields_worklist) {
1081 // Normally only 1-3 passes needed to build Connection Graph depending
1082 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1083 // Set limit to 20 to catch situation when something did go wrong and
1084 // bailout Escape Analysis.
1085 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1086 #define CG_BUILD_ITER_LIMIT 20
1087
1088 // Propagate GlobalEscape and ArgEscape escape states and check that
1089 // we still have non-escaping objects. The method pushs on _worklist
1090 // Field nodes which reference phantom_object.
1091 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1092 return false; // Nothing to do.
1093 }
1094 // Now propagate references to all JavaObject nodes.
1095 int java_objects_length = java_objects_worklist.length();
1096 elapsedTimer time;
1097 bool timeout = false;
1098 int new_edges = 1;
1099 int iterations = 0;
1100 do {
1101 while ((new_edges > 0) &&
1102 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1103 double start_time = time.seconds();
1104 time.start();
1105 new_edges = 0;
1106 // Propagate references to phantom_object for nodes pushed on _worklist
1107 // by find_non_escaped_objects() and find_field_value().
1108 new_edges += add_java_object_edges(phantom_obj, false);
1109 for (int next = 0; next < java_objects_length; ++next) {
1110 JavaObjectNode* ptn = java_objects_worklist.at(next);
1111 new_edges += add_java_object_edges(ptn, true);
1112
1113 #define SAMPLE_SIZE 4
1114 if ((next % SAMPLE_SIZE) == 0) {
1115 // Each 4 iterations calculate how much time it will take
1116 // to complete graph construction.
1117 time.stop();
1118 // Poll for requests from shutdown mechanism to quiesce compiler
1119 // because Connection graph construction may take long time.
1120 CompileBroker::maybe_block();
1121 double stop_time = time.seconds();
1122 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1123 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1124 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1125 timeout = true;
1126 break; // Timeout
1127 }
1128 start_time = stop_time;
1129 time.start();
1130 }
1131 #undef SAMPLE_SIZE
1132
1133 }
1134 if (timeout) break;
1135 if (new_edges > 0) {
1136 // Update escape states on each iteration if graph was updated.
1137 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1138 return false; // Nothing to do.
1139 }
1140 }
1141 time.stop();
1142 if (time.seconds() >= EscapeAnalysisTimeout) {
1143 timeout = true;
1144 break;
1145 }
1146 }
1147 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1148 time.start();
1149 // Find fields which have unknown value.
1150 int fields_length = oop_fields_worklist.length();
1151 for (int next = 0; next < fields_length; next++) {
1152 FieldNode* field = oop_fields_worklist.at(next);
1153 if (field->edge_count() == 0) {
1154 new_edges += find_field_value(field);
1155 // This code may added new edges to phantom_object.
1156 // Need an other cycle to propagate references to phantom_object.
1157 }
1158 }
1159 time.stop();
1160 if (time.seconds() >= EscapeAnalysisTimeout) {
1161 timeout = true;
1162 break;
1163 }
1164 } else {
1165 new_edges = 0; // Bailout
1166 }
1167 } while (new_edges > 0);
1168
1169 // Bailout if passed limits.
1170 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1171 Compile* C = _compile;
1172 if (C->log() != NULL) {
1173 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1174 C->log()->text("%s", timeout ? "time" : "iterations");
1175 C->log()->end_elem(" limit'");
1176 }
1177 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1178 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1179 // Possible infinite build_connection_graph loop,
1180 // bailout (no changes to ideal graph were made).
1181 return false;
1182 }
1183 #ifdef ASSERT
1184 if (Verbose && PrintEscapeAnalysis) {
1185 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1186 iterations, nodes_size(), ptnodes_worklist.length());
1187 }
1188 #endif
1189
1190 #undef CG_BUILD_ITER_LIMIT
1191
1192 // Find fields initialized by NULL for non-escaping Allocations.
1193 int non_escaped_length = non_escaped_worklist.length();
1194 for (int next = 0; next < non_escaped_length; next++) {
1195 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1196 PointsToNode::EscapeState es = ptn->escape_state();
1197 assert(es <= PointsToNode::ArgEscape, "sanity");
1198 if (es == PointsToNode::NoEscape) {
1199 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1200 // Adding references to NULL object does not change escape states
1201 // since it does not escape. Also no fields are added to NULL object.
1202 add_java_object_edges(null_obj, false);
1203 }
1204 }
1205 Node* n = ptn->ideal_node();
1206 if (n->is_Allocate()) {
1207 // The object allocated by this Allocate node will never be
1208 // seen by an other thread. Mark it so that when it is
1209 // expanded no MemBarStoreStore is added.
1210 InitializeNode* ini = n->as_Allocate()->initialization();
1211 if (ini != NULL)
1212 ini->set_does_not_escape();
1213 }
1214 }
1215 return true; // Finished graph construction.
1216 }
1217
1218 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1219 // and check that we still have non-escaping java objects.
1220 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1221 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1222 GrowableArray<PointsToNode*> escape_worklist;
1223 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1224 int ptnodes_length = ptnodes_worklist.length();
1225 for (int next = 0; next < ptnodes_length; ++next) {
1226 PointsToNode* ptn = ptnodes_worklist.at(next);
1227 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1228 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1229 escape_worklist.push(ptn);
1230 }
1231 }
1232 // Set escape states to referenced nodes (edges list).
1233 while (escape_worklist.length() > 0) {
1234 PointsToNode* ptn = escape_worklist.pop();
1235 PointsToNode::EscapeState es = ptn->escape_state();
1236 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1237 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1238 es >= PointsToNode::ArgEscape) {
1239 // GlobalEscape or ArgEscape state of field means it has unknown value.
1240 if (add_edge(ptn, phantom_obj)) {
1241 // New edge was added
1242 add_field_uses_to_worklist(ptn->as_Field());
1243 }
1244 }
1245 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1246 PointsToNode* e = i.get();
1247 if (e->is_Arraycopy()) {
1248 assert(ptn->arraycopy_dst(), "sanity");
1249 // Propagate only fields escape state through arraycopy edge.
1250 if (e->fields_escape_state() < field_es) {
1251 set_fields_escape_state(e, field_es);
1252 escape_worklist.push(e);
1253 }
1254 } else if (es >= field_es) {
1255 // fields_escape_state is also set to 'es' if it is less than 'es'.
1256 if (e->escape_state() < es) {
1257 set_escape_state(e, es);
1258 escape_worklist.push(e);
1259 }
1260 } else {
1261 // Propagate field escape state.
1262 bool es_changed = false;
1263 if (e->fields_escape_state() < field_es) {
1264 set_fields_escape_state(e, field_es);
1265 es_changed = true;
1266 }
1267 if ((e->escape_state() < field_es) &&
1268 e->is_Field() && ptn->is_JavaObject() &&
1269 e->as_Field()->is_oop()) {
1270 // Change escape state of referenced fileds.
1271 set_escape_state(e, field_es);
1272 es_changed = true;;
1273 } else if (e->escape_state() < es) {
1274 set_escape_state(e, es);
1275 es_changed = true;;
1276 }
1277 if (es_changed) {
1278 escape_worklist.push(e);
1279 }
1280 }
1281 }
1282 }
1283 // Remove escaped objects from non_escaped list.
1284 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1285 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1286 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1287 non_escaped_worklist.delete_at(next);
1288 }
1289 if (ptn->escape_state() == PointsToNode::NoEscape) {
1290 // Find fields in non-escaped allocations which have unknown value.
1291 find_init_values(ptn, phantom_obj, NULL);
1292 }
1293 }
1294 return (non_escaped_worklist.length() > 0);
1295 }
1296
1297 // Add all references to JavaObject node by walking over all uses.
1298 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1299 int new_edges = 0;
1300 if (populate_worklist) {
1301 // Populate _worklist by uses of jobj's uses.
1302 for (UseIterator i(jobj); i.has_next(); i.next()) {
1303 PointsToNode* use = i.get();
1304 if (use->is_Arraycopy())
1305 continue;
1306 add_uses_to_worklist(use);
1307 if (use->is_Field() && use->as_Field()->is_oop()) {
1308 // Put on worklist all field's uses (loads) and
1309 // related field nodes (same base and offset).
1310 add_field_uses_to_worklist(use->as_Field());
1311 }
1312 }
1313 }
1314 for (int l = 0; l < _worklist.length(); l++) {
1315 PointsToNode* use = _worklist.at(l);
1316 if (PointsToNode::is_base_use(use)) {
1317 // Add reference from jobj to field and from field to jobj (field's base).
1318 use = PointsToNode::get_use_node(use)->as_Field();
1319 if (add_base(use->as_Field(), jobj)) {
1320 new_edges++;
1321 }
1322 continue;
1323 }
1324 assert(!use->is_JavaObject(), "sanity");
1325 if (use->is_Arraycopy()) {
1326 if (jobj == null_obj) // NULL object does not have field edges
1327 continue;
1328 // Added edge from Arraycopy node to arraycopy's source java object
1329 if (add_edge(use, jobj)) {
1330 jobj->set_arraycopy_src();
1331 new_edges++;
1332 }
1333 // and stop here.
1334 continue;
1335 }
1336 if (!add_edge(use, jobj))
1337 continue; // No new edge added, there was such edge already.
1338 new_edges++;
1339 if (use->is_LocalVar()) {
1340 add_uses_to_worklist(use);
1341 if (use->arraycopy_dst()) {
1342 for (EdgeIterator i(use); i.has_next(); i.next()) {
1343 PointsToNode* e = i.get();
1344 if (e->is_Arraycopy()) {
1345 if (jobj == null_obj) // NULL object does not have field edges
1346 continue;
1347 // Add edge from arraycopy's destination java object to Arraycopy node.
1348 if (add_edge(jobj, e)) {
1349 new_edges++;
1350 jobj->set_arraycopy_dst();
1351 }
1352 }
1353 }
1354 }
1355 } else {
1356 // Added new edge to stored in field values.
1357 // Put on worklist all field's uses (loads) and
1358 // related field nodes (same base and offset).
1359 add_field_uses_to_worklist(use->as_Field());
1360 }
1361 }
1362 _worklist.clear();
1363 _in_worklist.Reset();
1364 return new_edges;
1365 }
1366
1367 // Put on worklist all related field nodes.
1368 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1369 assert(field->is_oop(), "sanity");
1370 int offset = field->offset();
1371 add_uses_to_worklist(field);
1372 // Loop over all bases of this field and push on worklist Field nodes
1373 // with the same offset and base (since they may reference the same field).
1374 for (BaseIterator i(field); i.has_next(); i.next()) {
1375 PointsToNode* base = i.get();
1376 add_fields_to_worklist(field, base);
1377 // Check if the base was source object of arraycopy and go over arraycopy's
1378 // destination objects since values stored to a field of source object are
1379 // accessable by uses (loads) of fields of destination objects.
1380 if (base->arraycopy_src()) {
1381 for (UseIterator j(base); j.has_next(); j.next()) {
1382 PointsToNode* arycp = j.get();
1383 if (arycp->is_Arraycopy()) {
1384 for (UseIterator k(arycp); k.has_next(); k.next()) {
1385 PointsToNode* abase = k.get();
1386 if (abase->arraycopy_dst() && abase != base) {
1387 // Look for the same arracopy reference.
1388 add_fields_to_worklist(field, abase);
1389 }
1390 }
1391 }
1392 }
1393 }
1394 }
1395 }
1396
1397 // Put on worklist all related field nodes.
1398 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1399 int offset = field->offset();
1400 if (base->is_LocalVar()) {
1401 for (UseIterator j(base); j.has_next(); j.next()) {
1402 PointsToNode* f = j.get();
1403 if (PointsToNode::is_base_use(f)) { // Field
1404 f = PointsToNode::get_use_node(f);
1405 if (f == field || !f->as_Field()->is_oop())
1406 continue;
1407 int offs = f->as_Field()->offset();
1408 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1409 add_to_worklist(f);
1410 }
1411 }
1412 }
1413 } else {
1414 assert(base->is_JavaObject(), "sanity");
1415 if (// Skip phantom_object since it is only used to indicate that
1416 // this field's content globally escapes.
1417 (base != phantom_obj) &&
1418 // NULL object node does not have fields.
1419 (base != null_obj)) {
1420 for (EdgeIterator i(base); i.has_next(); i.next()) {
1421 PointsToNode* f = i.get();
1422 // Skip arraycopy edge since store to destination object field
1423 // does not update value in source object field.
1424 if (f->is_Arraycopy()) {
1425 assert(base->arraycopy_dst(), "sanity");
1426 continue;
1427 }
1428 if (f == field || !f->as_Field()->is_oop())
1429 continue;
1430 int offs = f->as_Field()->offset();
1431 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1432 add_to_worklist(f);
1433 }
1434 }
1435 }
1436 }
1437 }
1438
1439 // Find fields which have unknown value.
1440 int ConnectionGraph::find_field_value(FieldNode* field) {
1441 // Escaped fields should have init value already.
1442 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1443 int new_edges = 0;
1444 for (BaseIterator i(field); i.has_next(); i.next()) {
1445 PointsToNode* base = i.get();
1446 if (base->is_JavaObject()) {
1447 // Skip Allocate's fields which will be processed later.
1448 if (base->ideal_node()->is_Allocate())
1449 return 0;
1450 assert(base == null_obj, "only NULL ptr base expected here");
1451 }
1452 }
1453 if (add_edge(field, phantom_obj)) {
1454 // New edge was added
1455 new_edges++;
1456 add_field_uses_to_worklist(field);
1457 }
1458 return new_edges;
1459 }
1460
1461 // Find fields initializing values for allocations.
1462 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1463 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1464 int new_edges = 0;
1465 Node* alloc = pta->ideal_node();
1466 if (init_val == phantom_obj) {
1467 // Do nothing for Allocate nodes since its fields values are "known".
1468 if (alloc->is_Allocate())
1469 return 0;
1470 assert(alloc->as_CallStaticJava(), "sanity");
1471 #ifdef ASSERT
1472 if (alloc->as_CallStaticJava()->method() == NULL) {
1473 const char* name = alloc->as_CallStaticJava()->_name;
1474 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1475 }
1476 #endif
1477 // Non-escaped allocation returned from Java or runtime call have
1478 // unknown values in fields.
1479 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1480 PointsToNode* field = i.get();
1481 if (field->is_Field() && field->as_Field()->is_oop()) {
1482 if (add_edge(field, phantom_obj)) {
1483 // New edge was added
1484 new_edges++;
1485 add_field_uses_to_worklist(field->as_Field());
1486 }
1487 }
1488 }
1489 return new_edges;
1490 }
1491 assert(init_val == null_obj, "sanity");
1492 // Do nothing for Call nodes since its fields values are unknown.
1493 if (!alloc->is_Allocate())
1494 return 0;
1495
1496 InitializeNode* ini = alloc->as_Allocate()->initialization();
1497 Compile* C = _compile;
1498 bool visited_bottom_offset = false;
1499 GrowableArray<int> offsets_worklist;
1500
1501 // Check if an oop field's initializing value is recorded and add
1502 // a corresponding NULL if field's value if it is not recorded.
1503 // Connection Graph does not record a default initialization by NULL
1504 // captured by Initialize node.
1505 //
1506 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1507 PointsToNode* field = i.get(); // Field (AddP)
1508 if (!field->is_Field() || !field->as_Field()->is_oop())
1509 continue; // Not oop field
1510 int offset = field->as_Field()->offset();
1511 if (offset == Type::OffsetBot) {
1512 if (!visited_bottom_offset) {
1513 // OffsetBot is used to reference array's element,
1514 // always add reference to NULL to all Field nodes since we don't
1515 // known which element is referenced.
1516 if (add_edge(field, null_obj)) {
1517 // New edge was added
1518 new_edges++;
1519 add_field_uses_to_worklist(field->as_Field());
1520 visited_bottom_offset = true;
1521 }
1522 }
1523 } else {
1524 // Check only oop fields.
1525 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1526 if (adr_type->isa_rawptr()) {
1527 #ifdef ASSERT
1528 // Raw pointers are used for initializing stores so skip it
1529 // since it should be recorded already
1530 Node* base = get_addp_base(field->ideal_node());
1531 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1532 (base->in(0) == alloc),"unexpected pointer type");
1533 #endif
1534 continue;
1535 }
1536 if (!offsets_worklist.contains(offset)) {
1537 offsets_worklist.append(offset);
1538 Node* value = NULL;
1539 if (ini != NULL) {
1540 // StoreP::memory_type() == T_ADDRESS
1541 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1542 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1543 // Make sure initializing store has the same type as this AddP.
1544 // This AddP may reference non existing field because it is on a
1545 // dead branch of bimorphic call which is not eliminated yet.
1546 if (store != NULL && store->is_Store() &&
1547 store->as_Store()->memory_type() == ft) {
1548 value = store->in(MemNode::ValueIn);
1549 #ifdef ASSERT
1550 if (VerifyConnectionGraph) {
1551 // Verify that AddP already points to all objects the value points to.
1552 PointsToNode* val = ptnode_adr(value->_idx);
1553 assert((val != NULL), "should be processed already");
1554 PointsToNode* missed_obj = NULL;
1555 if (val->is_JavaObject()) {
1556 if (!field->points_to(val->as_JavaObject())) {
1557 missed_obj = val;
1558 }
1559 } else {
1560 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1561 tty->print_cr("----------init store has invalid value -----");
1562 store->dump();
1563 val->dump();
1564 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1565 }
1566 for (EdgeIterator j(val); j.has_next(); j.next()) {
1567 PointsToNode* obj = j.get();
1568 if (obj->is_JavaObject()) {
1569 if (!field->points_to(obj->as_JavaObject())) {
1570 missed_obj = obj;
1571 break;
1572 }
1573 }
1574 }
1575 }
1576 if (missed_obj != NULL) {
1577 tty->print_cr("----------field---------------------------------");
1578 field->dump();
1579 tty->print_cr("----------missed referernce to object-----------");
1580 missed_obj->dump();
1581 tty->print_cr("----------object referernced by init store -----");
1582 store->dump();
1583 val->dump();
1584 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1585 }
1586 }
1587 #endif
1588 } else {
1589 // There could be initializing stores which follow allocation.
1590 // For example, a volatile field store is not collected
1591 // by Initialize node.
1592 //
1593 // Need to check for dependent loads to separate such stores from
1594 // stores which follow loads. For now, add initial value NULL so
1595 // that compare pointers optimization works correctly.
1596 }
1597 }
1598 if (value == NULL) {
1599 // A field's initializing value was not recorded. Add NULL.
1600 if (add_edge(field, null_obj)) {
1601 // New edge was added
1602 new_edges++;
1603 add_field_uses_to_worklist(field->as_Field());
1604 }
1605 }
1606 }
1607 }
1608 }
1609 return new_edges;
1610 }
1611
1612 // Adjust scalar_replaceable state after Connection Graph is built.
1613 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1614 // Search for non-escaping objects which are not scalar replaceable
1615 // and mark them to propagate the state to referenced objects.
1616
1617 // 1. An object is not scalar replaceable if the field into which it is
1618 // stored has unknown offset (stored into unknown element of an array).
1619 //
1620 for (UseIterator i(jobj); i.has_next(); i.next()) {
1621 PointsToNode* use = i.get();
1622 assert(!use->is_Arraycopy(), "sanity");
1623 if (use->is_Field()) {
1624 FieldNode* field = use->as_Field();
1625 assert(field->is_oop() && field->scalar_replaceable() &&
1626 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1627 if (field->offset() == Type::OffsetBot) {
1628 jobj->set_scalar_replaceable(false);
1629 return;
1630 }
1631 // 2. An object is not scalar replaceable if the field into which it is
1632 // stored has multiple bases one of which is null.
1633 if (field->base_count() > 1) {
1634 for (BaseIterator i(field); i.has_next(); i.next()) {
1635 PointsToNode* base = i.get();
1636 if (base == null_obj) {
1637 jobj->set_scalar_replaceable(false);
1638 return;
1639 }
1640 }
1641 }
1642 }
1643 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1644 // 3. An object is not scalar replaceable if it is merged with other objects.
1645 for (EdgeIterator j(use); j.has_next(); j.next()) {
1646 PointsToNode* ptn = j.get();
1647 if (ptn->is_JavaObject() && ptn != jobj) {
1648 // Mark all objects.
1649 jobj->set_scalar_replaceable(false);
1650 ptn->set_scalar_replaceable(false);
1651 }
1652 }
1653 if (!jobj->scalar_replaceable()) {
1654 return;
1655 }
1656 }
1657
1658 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1659 // Non-escaping object node should point only to field nodes.
1660 FieldNode* field = j.get()->as_Field();
1661 int offset = field->as_Field()->offset();
1662
1663 // 4. An object is not scalar replaceable if it has a field with unknown
1664 // offset (array's element is accessed in loop).
1665 if (offset == Type::OffsetBot) {
1666 jobj->set_scalar_replaceable(false);
1667 return;
1668 }
1669 // 5. Currently an object is not scalar replaceable if a LoadStore node
1670 // access its field since the field value is unknown after it.
1671 //
1672 Node* n = field->ideal_node();
1673 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1674 if (n->fast_out(i)->is_LoadStore()) {
1675 jobj->set_scalar_replaceable(false);
1676 return;
1677 }
1678 }
1679
1680 // 6. Or the address may point to more then one object. This may produce
1681 // the false positive result (set not scalar replaceable)
1682 // since the flow-insensitive escape analysis can't separate
1683 // the case when stores overwrite the field's value from the case
1684 // when stores happened on different control branches.
1685 //
1686 // Note: it will disable scalar replacement in some cases:
1687 //
1688 // Point p[] = new Point[1];
1689 // p[0] = new Point(); // Will be not scalar replaced
1690 //
1691 // but it will save us from incorrect optimizations in next cases:
1692 //
1693 // Point p[] = new Point[1];
1694 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1695 //
1696 if (field->base_count() > 1) {
1697 for (BaseIterator i(field); i.has_next(); i.next()) {
1698 PointsToNode* base = i.get();
1699 // Don't take into account LocalVar nodes which
1700 // may point to only one object which should be also
1701 // this field's base by now.
1702 if (base->is_JavaObject() && base != jobj) {
1703 // Mark all bases.
1704 jobj->set_scalar_replaceable(false);
1705 base->set_scalar_replaceable(false);
1706 }
1707 }
1708 }
1709 }
1710 }
1711
1712 #ifdef ASSERT
1713 void ConnectionGraph::verify_connection_graph(
1714 GrowableArray<PointsToNode*>& ptnodes_worklist,
1715 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1716 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1717 GrowableArray<Node*>& addp_worklist) {
1718 // Verify that graph is complete - no new edges could be added.
1719 int java_objects_length = java_objects_worklist.length();
1720 int non_escaped_length = non_escaped_worklist.length();
1721 int new_edges = 0;
1722 for (int next = 0; next < java_objects_length; ++next) {
1723 JavaObjectNode* ptn = java_objects_worklist.at(next);
1724 new_edges += add_java_object_edges(ptn, true);
1725 }
1726 assert(new_edges == 0, "graph was not complete");
1727 // Verify that escape state is final.
1728 int length = non_escaped_worklist.length();
1729 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1730 assert((non_escaped_length == non_escaped_worklist.length()) &&
1731 (non_escaped_length == length) &&
1732 (_worklist.length() == 0), "escape state was not final");
1733
1734 // Verify fields information.
1735 int addp_length = addp_worklist.length();
1736 for (int next = 0; next < addp_length; ++next ) {
1737 Node* n = addp_worklist.at(next);
1738 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1739 if (field->is_oop()) {
1740 // Verify that field has all bases
1741 Node* base = get_addp_base(n);
1742 PointsToNode* ptn = ptnode_adr(base->_idx);
1743 if (ptn->is_JavaObject()) {
1744 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1745 } else {
1746 assert(ptn->is_LocalVar(), "sanity");
1747 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1748 PointsToNode* e = i.get();
1749 if (e->is_JavaObject()) {
1750 assert(field->has_base(e->as_JavaObject()), "sanity");
1751 }
1752 }
1753 }
1754 // Verify that all fields have initializing values.
1755 if (field->edge_count() == 0) {
1756 tty->print_cr("----------field does not have references----------");
1757 field->dump();
1758 for (BaseIterator i(field); i.has_next(); i.next()) {
1759 PointsToNode* base = i.get();
1760 tty->print_cr("----------field has next base---------------------");
1761 base->dump();
1762 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1763 tty->print_cr("----------base has fields-------------------------");
1764 for (EdgeIterator j(base); j.has_next(); j.next()) {
1765 j.get()->dump();
1766 }
1767 tty->print_cr("----------base has references---------------------");
1768 for (UseIterator j(base); j.has_next(); j.next()) {
1769 j.get()->dump();
1770 }
1771 }
1772 }
1773 for (UseIterator i(field); i.has_next(); i.next()) {
1774 i.get()->dump();
1775 }
1776 assert(field->edge_count() > 0, "sanity");
1777 }
1778 }
1779 }
1780 }
1781 #endif
1782
1783 // Optimize ideal graph.
1784 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1785 GrowableArray<Node*>& storestore_worklist) {
1786 Compile* C = _compile;
1787 PhaseIterGVN* igvn = _igvn;
1788 if (EliminateLocks) {
1789 // Mark locks before changing ideal graph.
1790 int cnt = C->macro_count();
1791 for( int i=0; i < cnt; i++ ) {
1792 Node *n = C->macro_node(i);
1793 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1794 AbstractLockNode* alock = n->as_AbstractLock();
1795 if (!alock->is_non_esc_obj()) {
1796 if (not_global_escape(alock->obj_node())) {
1797 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1798 // The lock could be marked eliminated by lock coarsening
1799 // code during first IGVN before EA. Replace coarsened flag
1800 // to eliminate all associated locks/unlocks.
1801 #ifdef ASSERT
1802 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1803 #endif
1804 alock->set_non_esc_obj();
1805 }
1806 }
1807 }
1808 }
1809 }
1810
1811 if (OptimizePtrCompare) {
1812 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1813 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1814 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1815 // Optimize objects compare.
1816 while (ptr_cmp_worklist.length() != 0) {
1817 Node *n = ptr_cmp_worklist.pop();
1818 Node *res = optimize_ptr_compare(n);
1819 if (res != NULL) {
1820 #ifndef PRODUCT
1821 if (PrintOptimizePtrCompare) {
1822 tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ"));
1823 if (Verbose) {
1824 n->dump(1);
1825 }
1826 }
1827 #endif
1828 igvn->replace_node(n, res);
1829 }
1830 }
1831 // cleanup
1832 if (_pcmp_neq->outcnt() == 0)
1833 igvn->hash_delete(_pcmp_neq);
1834 if (_pcmp_eq->outcnt() == 0)
1835 igvn->hash_delete(_pcmp_eq);
1836 }
1837
1838 // For MemBarStoreStore nodes added in library_call.cpp, check
1839 // escape status of associated AllocateNode and optimize out
1840 // MemBarStoreStore node if the allocated object never escapes.
1841 while (storestore_worklist.length() != 0) {
1842 Node *n = storestore_worklist.pop();
1843 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1844 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1845 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1846 if (not_global_escape(alloc)) {
1847 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1848 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1849 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1850 igvn->register_new_node_with_optimizer(mb);
1851 igvn->replace_node(storestore, mb);
1852 }
1853 }
1854 }
1855
1856 // Optimize objects compare.
1857 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1858 assert(OptimizePtrCompare, "sanity");
1859 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1860 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1861 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1862 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1863 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1864 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1865
1866 // Check simple cases first.
1867 if (jobj1 != NULL) {
1868 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1869 if (jobj1 == jobj2) {
1870 // Comparing the same not escaping object.
1871 return _pcmp_eq;
1872 }
1873 Node* obj = jobj1->ideal_node();
1874 // Comparing not escaping allocation.
1875 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1876 !ptn2->points_to(jobj1)) {
1877 return _pcmp_neq; // This includes nullness check.
1878 }
1879 }
1880 }
1881 if (jobj2 != NULL) {
1882 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1883 Node* obj = jobj2->ideal_node();
1884 // Comparing not escaping allocation.
1885 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1886 !ptn1->points_to(jobj2)) {
1887 return _pcmp_neq; // This includes nullness check.
1888 }
1889 }
1890 }
1891 if (jobj1 != NULL && jobj1 != phantom_obj &&
1892 jobj2 != NULL && jobj2 != phantom_obj &&
1893 jobj1->ideal_node()->is_Con() &&
1894 jobj2->ideal_node()->is_Con()) {
1895 // Klass or String constants compare. Need to be careful with
1896 // compressed pointers - compare types of ConN and ConP instead of nodes.
1897 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1898 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1899 if (t1->make_ptr() == t2->make_ptr()) {
1900 return _pcmp_eq;
1901 } else {
1902 return _pcmp_neq;
1903 }
1904 }
1905 if (ptn1->meet(ptn2)) {
1906 return NULL; // Sets are not disjoint
1907 }
1908
1909 // Sets are disjoint.
1910 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1911 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1912 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1913 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1914 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1915 set2_has_unknown_ptr && set1_has_null_ptr) {
1916 // Check nullness of unknown object.
1917 return NULL;
1918 }
1919
1920 // Disjointness by itself is not sufficient since
1921 // alias analysis is not complete for escaped objects.
1922 // Disjoint sets are definitely unrelated only when
1923 // at least one set has only not escaping allocations.
1924 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1925 if (ptn1->non_escaping_allocation()) {
1926 return _pcmp_neq;
1927 }
1928 }
1929 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1930 if (ptn2->non_escaping_allocation()) {
1931 return _pcmp_neq;
1932 }
1933 }
1934 return NULL;
1935 }
1936
1937 // Connection Graph constuction functions.
1938
1939 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1940 PointsToNode* ptadr = _nodes.at(n->_idx);
1941 if (ptadr != NULL) {
1942 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1943 return;
1944 }
1945 Compile* C = _compile;
1946 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
1947 _nodes.at_put(n->_idx, ptadr);
1948 }
1949
1950 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1951 PointsToNode* ptadr = _nodes.at(n->_idx);
1952 if (ptadr != NULL) {
1953 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1954 return;
1955 }
1956 Compile* C = _compile;
1957 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
1958 _nodes.at_put(n->_idx, ptadr);
1959 }
1960
1961 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1962 PointsToNode* ptadr = _nodes.at(n->_idx);
1963 if (ptadr != NULL) {
1964 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1965 return;
1966 }
1967 bool unsafe = false;
1968 bool is_oop = is_oop_field(n, offset, &unsafe);
1969 if (unsafe) {
1970 es = PointsToNode::GlobalEscape;
1971 }
1972 Compile* C = _compile;
1973 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
1974 _nodes.at_put(n->_idx, field);
1975 }
1976
1977 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1978 PointsToNode* src, PointsToNode* dst) {
1979 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1980 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1981 PointsToNode* ptadr = _nodes.at(n->_idx);
1982 if (ptadr != NULL) {
1983 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1984 return;
1985 }
1986 Compile* C = _compile;
1987 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
1988 _nodes.at_put(n->_idx, ptadr);
1989 // Add edge from arraycopy node to source object.
1990 (void)add_edge(ptadr, src);
1991 src->set_arraycopy_src();
1992 // Add edge from destination object to arraycopy node.
1993 (void)add_edge(dst, ptadr);
1994 dst->set_arraycopy_dst();
1995 }
1996
1997 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1998 const Type* adr_type = n->as_AddP()->bottom_type();
1999 BasicType bt = T_INT;
2000 if (offset == Type::OffsetBot) {
2001 // Check only oop fields.
2002 if (!adr_type->isa_aryptr() ||
2003 (adr_type->isa_aryptr()->klass() == NULL) ||
2004 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2005 // OffsetBot is used to reference array's element. Ignore first AddP.
2006 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2007 bt = T_OBJECT;
2008 }
2009 }
2010 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2011 if (adr_type->isa_instptr()) {
2012 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2013 if (field != NULL) {
2014 bt = field->layout_type();
2015 } else {
2016 // Check for unsafe oop field access
2017 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2018 int opcode = n->fast_out(i)->Opcode();
2019 if (opcode == Op_StoreP || opcode == Op_StoreN ||
2020 opcode == Op_LoadP || opcode == Op_LoadN ||
2021 opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
2022 opcode == Op_CompareAndSwapP || opcode == Op_CompareAndSwapN) {
2023 bt = T_OBJECT;
2024 (*unsafe) = true;
2025 break;
2026 }
2027 }
2028 }
2029 } else if (adr_type->isa_aryptr()) {
2030 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2031 // Ignore array length load.
2032 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2033 // Ignore first AddP.
2034 } else {
2035 const Type* elemtype = adr_type->isa_aryptr()->elem();
2036 bt = elemtype->array_element_basic_type();
2037 }
2038 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2039 // Allocation initialization, ThreadLocal field access, unsafe access
2040 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2041 int opcode = n->fast_out(i)->Opcode();
2042 if (opcode == Op_StoreP || opcode == Op_StoreN ||
2043 opcode == Op_LoadP || opcode == Op_LoadN ||
2044 opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
2045 opcode == Op_CompareAndSwapP || opcode == Op_CompareAndSwapN) {
2046 bt = T_OBJECT;
2047 break;
2048 }
2049 }
2050 }
2051 }
2052 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2053 }
2054
2055 // Returns unique pointed java object or NULL.
2056 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2057 assert(!_collecting, "should not call when contructed graph");
2058 // If the node was created after the escape computation we can't answer.
2059 uint idx = n->_idx;
2060 if (idx >= nodes_size()) {
2061 return NULL;
2062 }
2063 PointsToNode* ptn = ptnode_adr(idx);
2064 if (ptn->is_JavaObject()) {
2065 return ptn->as_JavaObject();
2066 }
2067 assert(ptn->is_LocalVar(), "sanity");
2068 // Check all java objects it points to.
2069 JavaObjectNode* jobj = NULL;
2070 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2071 PointsToNode* e = i.get();
2072 if (e->is_JavaObject()) {
2073 if (jobj == NULL) {
2074 jobj = e->as_JavaObject();
2075 } else if (jobj != e) {
2076 return NULL;
2077 }
2078 }
2079 }
2080 return jobj;
2081 }
2082
2083 // Return true if this node points only to non-escaping allocations.
2084 bool PointsToNode::non_escaping_allocation() {
2085 if (is_JavaObject()) {
2086 Node* n = ideal_node();
2087 if (n->is_Allocate() || n->is_CallStaticJava()) {
2088 return (escape_state() == PointsToNode::NoEscape);
2089 } else {
2090 return false;
2091 }
2092 }
2093 assert(is_LocalVar(), "sanity");
2094 // Check all java objects it points to.
2095 for (EdgeIterator i(this); i.has_next(); i.next()) {
2096 PointsToNode* e = i.get();
2097 if (e->is_JavaObject()) {
2098 Node* n = e->ideal_node();
2099 if ((e->escape_state() != PointsToNode::NoEscape) ||
2100 !(n->is_Allocate() || n->is_CallStaticJava())) {
2101 return false;
2102 }
2103 }
2104 }
2105 return true;
2106 }
2107
2108 // Return true if we know the node does not escape globally.
2109 bool ConnectionGraph::not_global_escape(Node *n) {
2110 assert(!_collecting, "should not call during graph construction");
2111 // If the node was created after the escape computation we can't answer.
2112 uint idx = n->_idx;
2113 if (idx >= nodes_size()) {
2114 return false;
2115 }
2116 PointsToNode* ptn = ptnode_adr(idx);
2117 PointsToNode::EscapeState es = ptn->escape_state();
2118 // If we have already computed a value, return it.
2119 if (es >= PointsToNode::GlobalEscape)
2120 return false;
2121 if (ptn->is_JavaObject()) {
2122 return true; // (es < PointsToNode::GlobalEscape);
2123 }
2124 assert(ptn->is_LocalVar(), "sanity");
2125 // Check all java objects it points to.
2126 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2127 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2128 return false;
2129 }
2130 return true;
2131 }
2132
2133
2134 // Helper functions
2135
2136 // Return true if this node points to specified node or nodes it points to.
2137 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2138 if (is_JavaObject()) {
2139 return (this == ptn);
2140 }
2141 assert(is_LocalVar() || is_Field(), "sanity");
2142 for (EdgeIterator i(this); i.has_next(); i.next()) {
2143 if (i.get() == ptn)
2144 return true;
2145 }
2146 return false;
2147 }
2148
2149 // Return true if one node points to an other.
2150 bool PointsToNode::meet(PointsToNode* ptn) {
2151 if (this == ptn) {
2152 return true;
2153 } else if (ptn->is_JavaObject()) {
2154 return this->points_to(ptn->as_JavaObject());
2155 } else if (this->is_JavaObject()) {
2156 return ptn->points_to(this->as_JavaObject());
2157 }
2158 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2159 int ptn_count = ptn->edge_count();
2160 for (EdgeIterator i(this); i.has_next(); i.next()) {
2161 PointsToNode* this_e = i.get();
2162 for (int j = 0; j < ptn_count; j++) {
2163 if (this_e == ptn->edge(j))
2164 return true;
2165 }
2166 }
2167 return false;
2168 }
2169
2170 #ifdef ASSERT
2171 // Return true if bases point to this java object.
2172 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2173 for (BaseIterator i(this); i.has_next(); i.next()) {
2174 if (i.get() == jobj)
2175 return true;
2176 }
2177 return false;
2178 }
2179 #endif
2180
2181 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2182 const Type *adr_type = phase->type(adr);
2183 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2184 adr->in(AddPNode::Address)->is_Proj() &&
2185 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2186 // We are computing a raw address for a store captured by an Initialize
2187 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2188 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2189 assert(offs != Type::OffsetBot ||
2190 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2191 "offset must be a constant or it is initialization of array");
2192 return offs;
2193 }
2194 const TypePtr *t_ptr = adr_type->isa_ptr();
2195 assert(t_ptr != NULL, "must be a pointer type");
2196 return t_ptr->offset();
2197 }
2198
2199 Node* ConnectionGraph::get_addp_base(Node *addp) {
2200 assert(addp->is_AddP(), "must be AddP");
2201 //
2202 // AddP cases for Base and Address inputs:
2203 // case #1. Direct object's field reference:
2204 // Allocate
2205 // |
2206 // Proj #5 ( oop result )
2207 // |
2208 // CheckCastPP (cast to instance type)
2209 // | |
2210 // AddP ( base == address )
2211 //
2212 // case #2. Indirect object's field reference:
2213 // Phi
2214 // |
2215 // CastPP (cast to instance type)
2216 // | |
2217 // AddP ( base == address )
2218 //
2219 // case #3. Raw object's field reference for Initialize node:
2220 // Allocate
2221 // |
2222 // Proj #5 ( oop result )
2223 // top |
2224 // \ |
2225 // AddP ( base == top )
2226 //
2227 // case #4. Array's element reference:
2228 // {CheckCastPP | CastPP}
2229 // | | |
2230 // | AddP ( array's element offset )
2231 // | |
2232 // AddP ( array's offset )
2233 //
2234 // case #5. Raw object's field reference for arraycopy stub call:
2235 // The inline_native_clone() case when the arraycopy stub is called
2236 // after the allocation before Initialize and CheckCastPP nodes.
2237 // Allocate
2238 // |
2239 // Proj #5 ( oop result )
2240 // | |
2241 // AddP ( base == address )
2242 //
2243 // case #6. Constant Pool, ThreadLocal, CastX2P or
2244 // Raw object's field reference:
2245 // {ConP, ThreadLocal, CastX2P, raw Load}
2246 // top |
2247 // \ |
2248 // AddP ( base == top )
2249 //
2250 // case #7. Klass's field reference.
2251 // LoadKlass
2252 // | |
2253 // AddP ( base == address )
2254 //
2255 // case #8. narrow Klass's field reference.
2256 // LoadNKlass
2257 // |
2258 // DecodeN
2259 // | |
2260 // AddP ( base == address )
2261 //
2262 Node *base = addp->in(AddPNode::Base);
2263 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2264 base = addp->in(AddPNode::Address);
2265 while (base->is_AddP()) {
2266 // Case #6 (unsafe access) may have several chained AddP nodes.
2267 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2268 base = base->in(AddPNode::Address);
2269 }
2270 Node* uncast_base = base->uncast();
2271 int opcode = uncast_base->Opcode();
2272 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2273 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2274 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2275 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2276 }
2277 return base;
2278 }
2279
2280 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2281 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2282 Node* addp2 = addp->raw_out(0);
2283 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2284 addp2->in(AddPNode::Base) == n &&
2285 addp2->in(AddPNode::Address) == addp) {
2286 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2287 //
2288 // Find array's offset to push it on worklist first and
2289 // as result process an array's element offset first (pushed second)
2290 // to avoid CastPP for the array's offset.
2291 // Otherwise the inserted CastPP (LocalVar) will point to what
2292 // the AddP (Field) points to. Which would be wrong since
2293 // the algorithm expects the CastPP has the same point as
2294 // as AddP's base CheckCastPP (LocalVar).
2295 //
2296 // ArrayAllocation
2297 // |
2298 // CheckCastPP
2299 // |
2300 // memProj (from ArrayAllocation CheckCastPP)
2301 // | ||
2302 // | || Int (element index)
2303 // | || | ConI (log(element size))
2304 // | || | /
2305 // | || LShift
2306 // | || /
2307 // | AddP (array's element offset)
2308 // | |
2309 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2310 // | / /
2311 // AddP (array's offset)
2312 // |
2313 // Load/Store (memory operation on array's element)
2314 //
2315 return addp2;
2316 }
2317 return NULL;
2318 }
2319
2320 //
2321 // Adjust the type and inputs of an AddP which computes the
2322 // address of a field of an instance
2323 //
2324 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2325 PhaseGVN* igvn = _igvn;
2326 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2327 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2328 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2329 if (t == NULL) {
2330 // We are computing a raw address for a store captured by an Initialize
2331 // compute an appropriate address type (cases #3 and #5).
2332 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2333 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2334 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2335 assert(offs != Type::OffsetBot, "offset must be a constant");
2336 t = base_t->add_offset(offs)->is_oopptr();
2337 }
2338 int inst_id = base_t->instance_id();
2339 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2340 "old type must be non-instance or match new type");
2341
2342 // The type 't' could be subclass of 'base_t'.
2343 // As result t->offset() could be large then base_t's size and it will
2344 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2345 // constructor verifies correctness of the offset.
2346 //
2347 // It could happened on subclass's branch (from the type profiling
2348 // inlining) which was not eliminated during parsing since the exactness
2349 // of the allocation type was not propagated to the subclass type check.
2350 //
2351 // Or the type 't' could be not related to 'base_t' at all.
2352 // It could happened when CHA type is different from MDO type on a dead path
2353 // (for example, from instanceof check) which is not collapsed during parsing.
2354 //
2355 // Do nothing for such AddP node and don't process its users since
2356 // this code branch will go away.
2357 //
2358 if (!t->is_known_instance() &&
2359 !base_t->klass()->is_subtype_of(t->klass())) {
2360 return false; // bail out
2361 }
2362 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2363 // Do NOT remove the next line: ensure a new alias index is allocated
2364 // for the instance type. Note: C++ will not remove it since the call
2365 // has side effect.
2366 int alias_idx = _compile->get_alias_index(tinst);
2367 igvn->set_type(addp, tinst);
2368 // record the allocation in the node map
2369 set_map(addp, get_map(base->_idx));
2370 // Set addp's Base and Address to 'base'.
2371 Node *abase = addp->in(AddPNode::Base);
2372 Node *adr = addp->in(AddPNode::Address);
2373 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2374 adr->in(0)->_idx == (uint)inst_id) {
2375 // Skip AddP cases #3 and #5.
2376 } else {
2377 assert(!abase->is_top(), "sanity"); // AddP case #3
2378 if (abase != base) {
2379 igvn->hash_delete(addp);
2380 addp->set_req(AddPNode::Base, base);
2381 if (abase == adr) {
2382 addp->set_req(AddPNode::Address, base);
2383 } else {
2384 // AddP case #4 (adr is array's element offset AddP node)
2385 #ifdef ASSERT
2386 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2387 assert(adr->is_AddP() && atype != NULL &&
2388 atype->instance_id() == inst_id, "array's element offset should be processed first");
2389 #endif
2390 }
2391 igvn->hash_insert(addp);
2392 }
2393 }
2394 // Put on IGVN worklist since at least addp's type was changed above.
2395 record_for_optimizer(addp);
2396 return true;
2397 }
2398
2399 //
2400 // Create a new version of orig_phi if necessary. Returns either the newly
2401 // created phi or an existing phi. Sets create_new to indicate whether a new
2402 // phi was created. Cache the last newly created phi in the node map.
2403 //
2404 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2405 Compile *C = _compile;
2406 PhaseGVN* igvn = _igvn;
2407 new_created = false;
2408 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2409 // nothing to do if orig_phi is bottom memory or matches alias_idx
2410 if (phi_alias_idx == alias_idx) {
2411 return orig_phi;
2412 }
2413 // Have we recently created a Phi for this alias index?
2414 PhiNode *result = get_map_phi(orig_phi->_idx);
2415 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2416 return result;
2417 }
2418 // Previous check may fail when the same wide memory Phi was split into Phis
2419 // for different memory slices. Search all Phis for this region.
2420 if (result != NULL) {
2421 Node* region = orig_phi->in(0);
2422 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2423 Node* phi = region->fast_out(i);
2424 if (phi->is_Phi() &&
2425 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2426 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2427 return phi->as_Phi();
2428 }
2429 }
2430 }
2431 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2432 if (C->do_escape_analysis() == true && !C->failing()) {
2433 // Retry compilation without escape analysis.
2434 // If this is the first failure, the sentinel string will "stick"
2435 // to the Compile object, and the C2Compiler will see it and retry.
2436 C->record_failure(C2Compiler::retry_no_escape_analysis());
2437 }
2438 return NULL;
2439 }
2440 orig_phi_worklist.append_if_missing(orig_phi);
2441 const TypePtr *atype = C->get_adr_type(alias_idx);
2442 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2443 C->copy_node_notes_to(result, orig_phi);
2444 igvn->set_type(result, result->bottom_type());
2445 record_for_optimizer(result);
2446 set_map(orig_phi, result);
2447 new_created = true;
2448 return result;
2449 }
2450
2451 //
2452 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2453 // specified alias index.
2454 //
2455 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2456 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2457 Compile *C = _compile;
2458 PhaseGVN* igvn = _igvn;
2459 bool new_phi_created;
2460 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2461 if (!new_phi_created) {
2462 return result;
2463 }
2464 GrowableArray<PhiNode *> phi_list;
2465 GrowableArray<uint> cur_input;
2466 PhiNode *phi = orig_phi;
2467 uint idx = 1;
2468 bool finished = false;
2469 while(!finished) {
2470 while (idx < phi->req()) {
2471 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2472 if (mem != NULL && mem->is_Phi()) {
2473 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2474 if (new_phi_created) {
2475 // found an phi for which we created a new split, push current one on worklist and begin
2476 // processing new one
2477 phi_list.push(phi);
2478 cur_input.push(idx);
2479 phi = mem->as_Phi();
2480 result = newphi;
2481 idx = 1;
2482 continue;
2483 } else {
2484 mem = newphi;
2485 }
2486 }
2487 if (C->failing()) {
2488 return NULL;
2489 }
2490 result->set_req(idx++, mem);
2491 }
2492 #ifdef ASSERT
2493 // verify that the new Phi has an input for each input of the original
2494 assert( phi->req() == result->req(), "must have same number of inputs.");
2495 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2496 #endif
2497 // Check if all new phi's inputs have specified alias index.
2498 // Otherwise use old phi.
2499 for (uint i = 1; i < phi->req(); i++) {
2500 Node* in = result->in(i);
2501 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2502 }
2503 // we have finished processing a Phi, see if there are any more to do
2504 finished = (phi_list.length() == 0 );
2505 if (!finished) {
2506 phi = phi_list.pop();
2507 idx = cur_input.pop();
2508 PhiNode *prev_result = get_map_phi(phi->_idx);
2509 prev_result->set_req(idx++, result);
2510 result = prev_result;
2511 }
2512 }
2513 return result;
2514 }
2515
2516 //
2517 // The next methods are derived from methods in MemNode.
2518 //
2519 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2520 Node *mem = mmem;
2521 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2522 // means an array I have not precisely typed yet. Do not do any
2523 // alias stuff with it any time soon.
2524 if (toop->base() != Type::AnyPtr &&
2525 !(toop->klass() != NULL &&
2526 toop->klass()->is_java_lang_Object() &&
2527 toop->offset() == Type::OffsetBot)) {
2528 mem = mmem->memory_at(alias_idx);
2529 // Update input if it is progress over what we have now
2530 }
2531 return mem;
2532 }
2533
2534 //
2535 // Move memory users to their memory slices.
2536 //
2537 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2538 Compile* C = _compile;
2539 PhaseGVN* igvn = _igvn;
2540 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2541 assert(tp != NULL, "ptr type");
2542 int alias_idx = C->get_alias_index(tp);
2543 int general_idx = C->get_general_index(alias_idx);
2544
2545 // Move users first
2546 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2547 Node* use = n->fast_out(i);
2548 if (use->is_MergeMem()) {
2549 MergeMemNode* mmem = use->as_MergeMem();
2550 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2551 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2552 continue; // Nothing to do
2553 }
2554 // Replace previous general reference to mem node.
2555 uint orig_uniq = C->unique();
2556 Node* m = find_inst_mem(n, general_idx, orig_phis);
2557 assert(orig_uniq == C->unique(), "no new nodes");
2558 mmem->set_memory_at(general_idx, m);
2559 --imax;
2560 --i;
2561 } else if (use->is_MemBar()) {
2562 assert(!use->is_Initialize(), "initializing stores should not be moved");
2563 if (use->req() > MemBarNode::Precedent &&
2564 use->in(MemBarNode::Precedent) == n) {
2565 // Don't move related membars.
2566 record_for_optimizer(use);
2567 continue;
2568 }
2569 tp = use->as_MemBar()->adr_type()->isa_ptr();
2570 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2571 alias_idx == general_idx) {
2572 continue; // Nothing to do
2573 }
2574 // Move to general memory slice.
2575 uint orig_uniq = C->unique();
2576 Node* m = find_inst_mem(n, general_idx, orig_phis);
2577 assert(orig_uniq == C->unique(), "no new nodes");
2578 igvn->hash_delete(use);
2579 imax -= use->replace_edge(n, m);
2580 igvn->hash_insert(use);
2581 record_for_optimizer(use);
2582 --i;
2583 #ifdef ASSERT
2584 } else if (use->is_Mem()) {
2585 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2586 // Don't move related cardmark.
2587 continue;
2588 }
2589 // Memory nodes should have new memory input.
2590 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2591 assert(tp != NULL, "ptr type");
2592 int idx = C->get_alias_index(tp);
2593 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2594 "Following memory nodes should have new memory input or be on the same memory slice");
2595 } else if (use->is_Phi()) {
2596 // Phi nodes should be split and moved already.
2597 tp = use->as_Phi()->adr_type()->isa_ptr();
2598 assert(tp != NULL, "ptr type");
2599 int idx = C->get_alias_index(tp);
2600 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2601 } else {
2602 use->dump();
2603 assert(false, "should not be here");
2604 #endif
2605 }
2606 }
2607 }
2608
2609 //
2610 // Search memory chain of "mem" to find a MemNode whose address
2611 // is the specified alias index.
2612 //
2613 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2614 if (orig_mem == NULL)
2615 return orig_mem;
2616 Compile* C = _compile;
2617 PhaseGVN* igvn = _igvn;
2618 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2619 bool is_instance = (toop != NULL) && toop->is_known_instance();
2620 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2621 Node *prev = NULL;
2622 Node *result = orig_mem;
2623 while (prev != result) {
2624 prev = result;
2625 if (result == start_mem)
2626 break; // hit one of our sentinels
2627 if (result->is_Mem()) {
2628 const Type *at = igvn->type(result->in(MemNode::Address));
2629 if (at == Type::TOP)
2630 break; // Dead
2631 assert (at->isa_ptr() != NULL, "pointer type required.");
2632 int idx = C->get_alias_index(at->is_ptr());
2633 if (idx == alias_idx)
2634 break; // Found
2635 if (!is_instance && (at->isa_oopptr() == NULL ||
2636 !at->is_oopptr()->is_known_instance())) {
2637 break; // Do not skip store to general memory slice.
2638 }
2639 result = result->in(MemNode::Memory);
2640 }
2641 if (!is_instance)
2642 continue; // don't search further for non-instance types
2643 // skip over a call which does not affect this memory slice
2644 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2645 Node *proj_in = result->in(0);
2646 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2647 break; // hit one of our sentinels
2648 } else if (proj_in->is_Call()) {
2649 CallNode *call = proj_in->as_Call();
2650 if (!call->may_modify(toop, igvn)) {
2651 result = call->in(TypeFunc::Memory);
2652 }
2653 } else if (proj_in->is_Initialize()) {
2654 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2655 // Stop if this is the initialization for the object instance which
2656 // which contains this memory slice, otherwise skip over it.
2657 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2658 result = proj_in->in(TypeFunc::Memory);
2659 }
2660 } else if (proj_in->is_MemBar()) {
2661 result = proj_in->in(TypeFunc::Memory);
2662 }
2663 } else if (result->is_MergeMem()) {
2664 MergeMemNode *mmem = result->as_MergeMem();
2665 result = step_through_mergemem(mmem, alias_idx, toop);
2666 if (result == mmem->base_memory()) {
2667 // Didn't find instance memory, search through general slice recursively.
2668 result = mmem->memory_at(C->get_general_index(alias_idx));
2669 result = find_inst_mem(result, alias_idx, orig_phis);
2670 if (C->failing()) {
2671 return NULL;
2672 }
2673 mmem->set_memory_at(alias_idx, result);
2674 }
2675 } else if (result->is_Phi() &&
2676 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2677 Node *un = result->as_Phi()->unique_input(igvn);
2678 if (un != NULL) {
2679 orig_phis.append_if_missing(result->as_Phi());
2680 result = un;
2681 } else {
2682 break;
2683 }
2684 } else if (result->is_ClearArray()) {
2685 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2686 // Can not bypass initialization of the instance
2687 // we are looking for.
2688 break;
2689 }
2690 // Otherwise skip it (the call updated 'result' value).
2691 } else if (result->Opcode() == Op_SCMemProj) {
2692 Node* mem = result->in(0);
2693 Node* adr = NULL;
2694 if (mem->is_LoadStore()) {
2695 adr = mem->in(MemNode::Address);
2696 } else {
2697 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2698 adr = mem->in(3); // Memory edge corresponds to destination array
2699 }
2700 const Type *at = igvn->type(adr);
2701 if (at != Type::TOP) {
2702 assert (at->isa_ptr() != NULL, "pointer type required.");
2703 int idx = C->get_alias_index(at->is_ptr());
2704 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2705 break;
2706 }
2707 result = mem->in(MemNode::Memory);
2708 }
2709 }
2710 if (result->is_Phi()) {
2711 PhiNode *mphi = result->as_Phi();
2712 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2713 const TypePtr *t = mphi->adr_type();
2714 if (!is_instance) {
2715 // Push all non-instance Phis on the orig_phis worklist to update inputs
2716 // during Phase 4 if needed.
2717 orig_phis.append_if_missing(mphi);
2718 } else if (C->get_alias_index(t) != alias_idx) {
2719 // Create a new Phi with the specified alias index type.
2720 result = split_memory_phi(mphi, alias_idx, orig_phis);
2721 }
2722 }
2723 // the result is either MemNode, PhiNode, InitializeNode.
2724 return result;
2725 }
2726
2727 //
2728 // Convert the types of unescaped object to instance types where possible,
2729 // propagate the new type information through the graph, and update memory
2730 // edges and MergeMem inputs to reflect the new type.
2731 //
2732 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2733 // The processing is done in 4 phases:
2734 //
2735 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2736 // types for the CheckCastPP for allocations where possible.
2737 // Propagate the the new types through users as follows:
2738 // casts and Phi: push users on alloc_worklist
2739 // AddP: cast Base and Address inputs to the instance type
2740 // push any AddP users on alloc_worklist and push any memnode
2741 // users onto memnode_worklist.
2742 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2743 // search the Memory chain for a store with the appropriate type
2744 // address type. If a Phi is found, create a new version with
2745 // the appropriate memory slices from each of the Phi inputs.
2746 // For stores, process the users as follows:
2747 // MemNode: push on memnode_worklist
2748 // MergeMem: push on mergemem_worklist
2749 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2750 // moving the first node encountered of each instance type to the
2751 // the input corresponding to its alias index.
2752 // appropriate memory slice.
2753 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2754 //
2755 // In the following example, the CheckCastPP nodes are the cast of allocation
2756 // results and the allocation of node 29 is unescaped and eligible to be an
2757 // instance type.
2758 //
2759 // We start with:
2760 //
2761 // 7 Parm #memory
2762 // 10 ConI "12"
2763 // 19 CheckCastPP "Foo"
2764 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2765 // 29 CheckCastPP "Foo"
2766 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2767 //
2768 // 40 StoreP 25 7 20 ... alias_index=4
2769 // 50 StoreP 35 40 30 ... alias_index=4
2770 // 60 StoreP 45 50 20 ... alias_index=4
2771 // 70 LoadP _ 60 30 ... alias_index=4
2772 // 80 Phi 75 50 60 Memory alias_index=4
2773 // 90 LoadP _ 80 30 ... alias_index=4
2774 // 100 LoadP _ 80 20 ... alias_index=4
2775 //
2776 //
2777 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2778 // and creating a new alias index for node 30. This gives:
2779 //
2780 // 7 Parm #memory
2781 // 10 ConI "12"
2782 // 19 CheckCastPP "Foo"
2783 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2784 // 29 CheckCastPP "Foo" iid=24
2785 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2786 //
2787 // 40 StoreP 25 7 20 ... alias_index=4
2788 // 50 StoreP 35 40 30 ... alias_index=6
2789 // 60 StoreP 45 50 20 ... alias_index=4
2790 // 70 LoadP _ 60 30 ... alias_index=6
2791 // 80 Phi 75 50 60 Memory alias_index=4
2792 // 90 LoadP _ 80 30 ... alias_index=6
2793 // 100 LoadP _ 80 20 ... alias_index=4
2794 //
2795 // In phase 2, new memory inputs are computed for the loads and stores,
2796 // And a new version of the phi is created. In phase 4, the inputs to
2797 // node 80 are updated and then the memory nodes are updated with the
2798 // values computed in phase 2. This results in:
2799 //
2800 // 7 Parm #memory
2801 // 10 ConI "12"
2802 // 19 CheckCastPP "Foo"
2803 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2804 // 29 CheckCastPP "Foo" iid=24
2805 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2806 //
2807 // 40 StoreP 25 7 20 ... alias_index=4
2808 // 50 StoreP 35 7 30 ... alias_index=6
2809 // 60 StoreP 45 40 20 ... alias_index=4
2810 // 70 LoadP _ 50 30 ... alias_index=6
2811 // 80 Phi 75 40 60 Memory alias_index=4
2812 // 120 Phi 75 50 50 Memory alias_index=6
2813 // 90 LoadP _ 120 30 ... alias_index=6
2814 // 100 LoadP _ 80 20 ... alias_index=4
2815 //
2816 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2817 GrowableArray<Node *> memnode_worklist;
2818 GrowableArray<PhiNode *> orig_phis;
2819 PhaseIterGVN *igvn = _igvn;
2820 uint new_index_start = (uint) _compile->num_alias_types();
2821 Arena* arena = Thread::current()->resource_area();
2822 VectorSet visited(arena);
2823 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2824 uint unique_old = _compile->unique();
2825
2826 // Phase 1: Process possible allocations from alloc_worklist.
2827 // Create instance types for the CheckCastPP for allocations where possible.
2828 //
2829 // (Note: don't forget to change the order of the second AddP node on
2830 // the alloc_worklist if the order of the worklist processing is changed,
2831 // see the comment in find_second_addp().)
2832 //
2833 while (alloc_worklist.length() != 0) {
2834 Node *n = alloc_worklist.pop();
2835 uint ni = n->_idx;
2836 if (n->is_Call()) {
2837 CallNode *alloc = n->as_Call();
2838 // copy escape information to call node
2839 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2840 PointsToNode::EscapeState es = ptn->escape_state();
2841 // We have an allocation or call which returns a Java object,
2842 // see if it is unescaped.
2843 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2844 continue;
2845 // Find CheckCastPP for the allocate or for the return value of a call
2846 n = alloc->result_cast();
2847 if (n == NULL) { // No uses except Initialize node
2848 if (alloc->is_Allocate()) {
2849 // Set the scalar_replaceable flag for allocation
2850 // so it could be eliminated if it has no uses.
2851 alloc->as_Allocate()->_is_scalar_replaceable = true;
2852 }
2853 if (alloc->is_CallStaticJava()) {
2854 // Set the scalar_replaceable flag for boxing method
2855 // so it could be eliminated if it has no uses.
2856 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2857 }
2858 continue;
2859 }
2860 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2861 assert(!alloc->is_Allocate(), "allocation should have unique type");
2862 continue;
2863 }
2864
2865 // The inline code for Object.clone() casts the allocation result to
2866 // java.lang.Object and then to the actual type of the allocated
2867 // object. Detect this case and use the second cast.
2868 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2869 // the allocation result is cast to java.lang.Object and then
2870 // to the actual Array type.
2871 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2872 && (alloc->is_AllocateArray() ||
2873 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2874 Node *cast2 = NULL;
2875 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2876 Node *use = n->fast_out(i);
2877 if (use->is_CheckCastPP()) {
2878 cast2 = use;
2879 break;
2880 }
2881 }
2882 if (cast2 != NULL) {
2883 n = cast2;
2884 } else {
2885 // Non-scalar replaceable if the allocation type is unknown statically
2886 // (reflection allocation), the object can't be restored during
2887 // deoptimization without precise type.
2888 continue;
2889 }
2890 }
2891
2892 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2893 if (t == NULL)
2894 continue; // not a TypeOopPtr
2895 if (!t->klass_is_exact())
2896 continue; // not an unique type
2897
2898 if (alloc->is_Allocate()) {
2899 // Set the scalar_replaceable flag for allocation
2900 // so it could be eliminated.
2901 alloc->as_Allocate()->_is_scalar_replaceable = true;
2902 }
2903 if (alloc->is_CallStaticJava()) {
2904 // Set the scalar_replaceable flag for boxing method
2905 // so it could be eliminated.
2906 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2907 }
2908 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2909 // in order for an object to be scalar-replaceable, it must be:
2910 // - a direct allocation (not a call returning an object)
2911 // - non-escaping
2912 // - eligible to be a unique type
2913 // - not determined to be ineligible by escape analysis
2914 set_map(alloc, n);
2915 set_map(n, alloc);
2916 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2917 igvn->hash_delete(n);
2918 igvn->set_type(n, tinst);
2919 n->raise_bottom_type(tinst);
2920 igvn->hash_insert(n);
2921 record_for_optimizer(n);
2922 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2923
2924 // First, put on the worklist all Field edges from Connection Graph
2925 // which is more accurate then putting immediate users from Ideal Graph.
2926 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2927 PointsToNode* tgt = e.get();
2928 Node* use = tgt->ideal_node();
2929 assert(tgt->is_Field() && use->is_AddP(),
2930 "only AddP nodes are Field edges in CG");
2931 if (use->outcnt() > 0) { // Don't process dead nodes
2932 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2933 if (addp2 != NULL) {
2934 assert(alloc->is_AllocateArray(),"array allocation was expected");
2935 alloc_worklist.append_if_missing(addp2);
2936 }
2937 alloc_worklist.append_if_missing(use);
2938 }
2939 }
2940
2941 // An allocation may have an Initialize which has raw stores. Scan
2942 // the users of the raw allocation result and push AddP users
2943 // on alloc_worklist.
2944 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2945 assert (raw_result != NULL, "must have an allocation result");
2946 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2947 Node *use = raw_result->fast_out(i);
2948 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2949 Node* addp2 = find_second_addp(use, raw_result);
2950 if (addp2 != NULL) {
2951 assert(alloc->is_AllocateArray(),"array allocation was expected");
2952 alloc_worklist.append_if_missing(addp2);
2953 }
2954 alloc_worklist.append_if_missing(use);
2955 } else if (use->is_MemBar()) {
2956 memnode_worklist.append_if_missing(use);
2957 }
2958 }
2959 }
2960 } else if (n->is_AddP()) {
2961 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2962 if (jobj == NULL || jobj == phantom_obj) {
2963 #ifdef ASSERT
2964 ptnode_adr(get_addp_base(n)->_idx)->dump();
2965 ptnode_adr(n->_idx)->dump();
2966 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2967 #endif
2968 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2969 return;
2970 }
2971 Node *base = get_map(jobj->idx()); // CheckCastPP node
2972 if (!split_AddP(n, base)) continue; // wrong type from dead path
2973 } else if (n->is_Phi() ||
2974 n->is_CheckCastPP() ||
2975 n->is_EncodeP() ||
2976 n->is_DecodeN() ||
2977 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2978 if (visited.test_set(n->_idx)) {
2979 assert(n->is_Phi(), "loops only through Phi's");
2980 continue; // already processed
2981 }
2982 JavaObjectNode* jobj = unique_java_object(n);
2983 if (jobj == NULL || jobj == phantom_obj) {
2984 #ifdef ASSERT
2985 ptnode_adr(n->_idx)->dump();
2986 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2987 #endif
2988 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2989 return;
2990 } else {
2991 Node *val = get_map(jobj->idx()); // CheckCastPP node
2992 TypeNode *tn = n->as_Type();
2993 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2994 assert(tinst != NULL && tinst->is_known_instance() &&
2995 tinst->instance_id() == jobj->idx() , "instance type expected.");
2996
2997 const Type *tn_type = igvn->type(tn);
2998 const TypeOopPtr *tn_t;
2999 if (tn_type->isa_narrowoop()) {
3000 tn_t = tn_type->make_ptr()->isa_oopptr();
3001 } else {
3002 tn_t = tn_type->isa_oopptr();
3003 }
3004 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3005 if (tn_type->isa_narrowoop()) {
3006 tn_type = tinst->make_narrowoop();
3007 } else {
3008 tn_type = tinst;
3009 }
3010 igvn->hash_delete(tn);
3011 igvn->set_type(tn, tn_type);
3012 tn->set_type(tn_type);
3013 igvn->hash_insert(tn);
3014 record_for_optimizer(n);
3015 } else {
3016 assert(tn_type == TypePtr::NULL_PTR ||
3017 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3018 "unexpected type");
3019 continue; // Skip dead path with different type
3020 }
3021 }
3022 } else {
3023 debug_only(n->dump();)
3024 assert(false, "EA: unexpected node");
3025 continue;
3026 }
3027 // push allocation's users on appropriate worklist
3028 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3029 Node *use = n->fast_out(i);
3030 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3031 // Load/store to instance's field
3032 memnode_worklist.append_if_missing(use);
3033 } else if (use->is_MemBar()) {
3034 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3035 memnode_worklist.append_if_missing(use);
3036 }
3037 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3038 Node* addp2 = find_second_addp(use, n);
3039 if (addp2 != NULL) {
3040 alloc_worklist.append_if_missing(addp2);
3041 }
3042 alloc_worklist.append_if_missing(use);
3043 } else if (use->is_Phi() ||
3044 use->is_CheckCastPP() ||
3045 use->is_EncodeNarrowPtr() ||
3046 use->is_DecodeNarrowPtr() ||
3047 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3048 alloc_worklist.append_if_missing(use);
3049 #ifdef ASSERT
3050 } else if (use->is_Mem()) {
3051 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3052 } else if (use->is_MergeMem()) {
3053 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3054 } else if (use->is_SafePoint()) {
3055 // Look for MergeMem nodes for calls which reference unique allocation
3056 // (through CheckCastPP nodes) even for debug info.
3057 Node* m = use->in(TypeFunc::Memory);
3058 if (m->is_MergeMem()) {
3059 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3060 }
3061 } else if (use->Opcode() == Op_EncodeISOArray) {
3062 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3063 // EncodeISOArray overwrites destination array
3064 memnode_worklist.append_if_missing(use);
3065 }
3066 } else {
3067 uint op = use->Opcode();
3068 if (!(op == Op_CmpP || op == Op_Conv2B ||
3069 op == Op_CastP2X || op == Op_StoreCM ||
3070 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3071 op == Op_StrEquals || op == Op_StrIndexOf)) {
3072 n->dump();
3073 use->dump();
3074 assert(false, "EA: missing allocation reference path");
3075 }
3076 #endif
3077 }
3078 }
3079
3080 }
3081 // New alias types were created in split_AddP().
3082 uint new_index_end = (uint) _compile->num_alias_types();
3083 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3084
3085 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3086 // compute new values for Memory inputs (the Memory inputs are not
3087 // actually updated until phase 4.)
3088 if (memnode_worklist.length() == 0)
3089 return; // nothing to do
3090 while (memnode_worklist.length() != 0) {
3091 Node *n = memnode_worklist.pop();
3092 if (visited.test_set(n->_idx))
3093 continue;
3094 if (n->is_Phi() || n->is_ClearArray()) {
3095 // we don't need to do anything, but the users must be pushed
3096 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3097 // we don't need to do anything, but the users must be pushed
3098 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3099 if (n == NULL)
3100 continue;
3101 } else if (n->Opcode() == Op_EncodeISOArray) {
3102 // get the memory projection
3103 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3104 Node *use = n->fast_out(i);
3105 if (use->Opcode() == Op_SCMemProj) {
3106 n = use;
3107 break;
3108 }
3109 }
3110 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3111 } else {
3112 assert(n->is_Mem(), "memory node required.");
3113 Node *addr = n->in(MemNode::Address);
3114 const Type *addr_t = igvn->type(addr);
3115 if (addr_t == Type::TOP)
3116 continue;
3117 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3118 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3119 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3120 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3121 if (_compile->failing()) {
3122 return;
3123 }
3124 if (mem != n->in(MemNode::Memory)) {
3125 // We delay the memory edge update since we need old one in
3126 // MergeMem code below when instances memory slices are separated.
3127 set_map(n, mem);
3128 }
3129 if (n->is_Load()) {
3130 continue; // don't push users
3131 } else if (n->is_LoadStore()) {
3132 // get the memory projection
3133 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3134 Node *use = n->fast_out(i);
3135 if (use->Opcode() == Op_SCMemProj) {
3136 n = use;
3137 break;
3138 }
3139 }
3140 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3141 }
3142 }
3143 // push user on appropriate worklist
3144 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3145 Node *use = n->fast_out(i);
3146 if (use->is_Phi() || use->is_ClearArray()) {
3147 memnode_worklist.append_if_missing(use);
3148 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3149 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3150 continue;
3151 memnode_worklist.append_if_missing(use);
3152 } else if (use->is_MemBar()) {
3153 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3154 memnode_worklist.append_if_missing(use);
3155 }
3156 #ifdef ASSERT
3157 } else if(use->is_Mem()) {
3158 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3159 } else if (use->is_MergeMem()) {
3160 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3161 } else if (use->Opcode() == Op_EncodeISOArray) {
3162 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3163 // EncodeISOArray overwrites destination array
3164 memnode_worklist.append_if_missing(use);
3165 }
3166 } else {
3167 uint op = use->Opcode();
3168 if (!(op == Op_StoreCM ||
3169 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3170 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3171 op == Op_AryEq || op == Op_StrComp ||
3172 op == Op_StrEquals || op == Op_StrIndexOf)) {
3173 n->dump();
3174 use->dump();
3175 assert(false, "EA: missing memory path");
3176 }
3177 #endif
3178 }
3179 }
3180 }
3181
3182 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3183 // Walk each memory slice moving the first node encountered of each
3184 // instance type to the the input corresponding to its alias index.
3185 uint length = _mergemem_worklist.length();
3186 for( uint next = 0; next < length; ++next ) {
3187 MergeMemNode* nmm = _mergemem_worklist.at(next);
3188 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3189 // Note: we don't want to use MergeMemStream here because we only want to
3190 // scan inputs which exist at the start, not ones we add during processing.
3191 // Note 2: MergeMem may already contains instance memory slices added
3192 // during find_inst_mem() call when memory nodes were processed above.
3193 igvn->hash_delete(nmm);
3194 uint nslices = MIN2(nmm->req(), new_index_start);
3195 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3196 Node* mem = nmm->in(i);
3197 Node* cur = NULL;
3198 if (mem == NULL || mem->is_top())
3199 continue;
3200 // First, update mergemem by moving memory nodes to corresponding slices
3201 // if their type became more precise since this mergemem was created.
3202 while (mem->is_Mem()) {
3203 const Type *at = igvn->type(mem->in(MemNode::Address));
3204 if (at != Type::TOP) {
3205 assert (at->isa_ptr() != NULL, "pointer type required.");
3206 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3207 if (idx == i) {
3208 if (cur == NULL)
3209 cur = mem;
3210 } else {
3211 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3212 nmm->set_memory_at(idx, mem);
3213 }
3214 }
3215 }
3216 mem = mem->in(MemNode::Memory);
3217 }
3218 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3219 // Find any instance of the current type if we haven't encountered
3220 // already a memory slice of the instance along the memory chain.
3221 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3222 if((uint)_compile->get_general_index(ni) == i) {
3223 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3224 if (nmm->is_empty_memory(m)) {
3225 Node* result = find_inst_mem(mem, ni, orig_phis);
3226 if (_compile->failing()) {
3227 return;
3228 }
3229 nmm->set_memory_at(ni, result);
3230 }
3231 }
3232 }
3233 }
3234 // Find the rest of instances values
3235 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3236 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3237 Node* result = step_through_mergemem(nmm, ni, tinst);
3238 if (result == nmm->base_memory()) {
3239 // Didn't find instance memory, search through general slice recursively.
3240 result = nmm->memory_at(_compile->get_general_index(ni));
3241 result = find_inst_mem(result, ni, orig_phis);
3242 if (_compile->failing()) {
3243 return;
3244 }
3245 nmm->set_memory_at(ni, result);
3246 }
3247 }
3248 igvn->hash_insert(nmm);
3249 record_for_optimizer(nmm);
3250 }
3251
3252 // Phase 4: Update the inputs of non-instance memory Phis and
3253 // the Memory input of memnodes
3254 // First update the inputs of any non-instance Phi's from
3255 // which we split out an instance Phi. Note we don't have
3256 // to recursively process Phi's encounted on the input memory
3257 // chains as is done in split_memory_phi() since they will
3258 // also be processed here.
3259 for (int j = 0; j < orig_phis.length(); j++) {
3260 PhiNode *phi = orig_phis.at(j);
3261 int alias_idx = _compile->get_alias_index(phi->adr_type());
3262 igvn->hash_delete(phi);
3263 for (uint i = 1; i < phi->req(); i++) {
3264 Node *mem = phi->in(i);
3265 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3266 if (_compile->failing()) {
3267 return;
3268 }
3269 if (mem != new_mem) {
3270 phi->set_req(i, new_mem);
3271 }
3272 }
3273 igvn->hash_insert(phi);
3274 record_for_optimizer(phi);
3275 }
3276
3277 // Update the memory inputs of MemNodes with the value we computed
3278 // in Phase 2 and move stores memory users to corresponding memory slices.
3279 // Disable memory split verification code until the fix for 6984348.
3280 // Currently it produces false negative results since it does not cover all cases.
3281 #if 0 // ifdef ASSERT
3282 visited.Reset();
3283 Node_Stack old_mems(arena, _compile->unique() >> 2);
3284 #endif
3285 for (uint i = 0; i < ideal_nodes.size(); i++) {
3286 Node* n = ideal_nodes.at(i);
3287 Node* nmem = get_map(n->_idx);
3288 assert(nmem != NULL, "sanity");
3289 if (n->is_Mem()) {
3290 #if 0 // ifdef ASSERT
3291 Node* old_mem = n->in(MemNode::Memory);
3292 if (!visited.test_set(old_mem->_idx)) {
3293 old_mems.push(old_mem, old_mem->outcnt());
3294 }
3295 #endif
3296 assert(n->in(MemNode::Memory) != nmem, "sanity");
3297 if (!n->is_Load()) {
3298 // Move memory users of a store first.
3299 move_inst_mem(n, orig_phis);
3300 }
3301 // Now update memory input
3302 igvn->hash_delete(n);
3303 n->set_req(MemNode::Memory, nmem);
3304 igvn->hash_insert(n);
3305 record_for_optimizer(n);
3306 } else {
3307 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3308 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3309 }
3310 }
3311 #if 0 // ifdef ASSERT
3312 // Verify that memory was split correctly
3313 while (old_mems.is_nonempty()) {
3314 Node* old_mem = old_mems.node();
3315 uint old_cnt = old_mems.index();
3316 old_mems.pop();
3317 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3318 }
3319 #endif
3320 }
3321
3322 #ifndef PRODUCT
3323 static const char *node_type_names[] = {
3324 "UnknownType",
3325 "JavaObject",
3326 "LocalVar",
3327 "Field",
3328 "Arraycopy"
3329 };
3330
3331 static const char *esc_names[] = {
3332 "UnknownEscape",
3333 "NoEscape",
3334 "ArgEscape",
3335 "GlobalEscape"
3336 };
3337
3338 void PointsToNode::dump(bool print_state) const {
3339 NodeType nt = node_type();
3340 tty->print("%s ", node_type_names[(int) nt]);
3341 if (print_state) {
3342 EscapeState es = escape_state();
3343 EscapeState fields_es = fields_escape_state();
3344 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3345 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3346 tty->print("NSR ");
3347 }
3348 if (is_Field()) {
3349 FieldNode* f = (FieldNode*)this;
3350 if (f->is_oop())
3351 tty->print("oop ");
3352 if (f->offset() > 0)
3353 tty->print("+%d ", f->offset());
3354 tty->print("(");
3355 for (BaseIterator i(f); i.has_next(); i.next()) {
3356 PointsToNode* b = i.get();
3357 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3358 }
3359 tty->print(" )");
3360 }
3361 tty->print("[");
3362 for (EdgeIterator i(this); i.has_next(); i.next()) {
3363 PointsToNode* e = i.get();
3364 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3365 }
3366 tty->print(" [");
3367 for (UseIterator i(this); i.has_next(); i.next()) {
3368 PointsToNode* u = i.get();
3369 bool is_base = false;
3370 if (PointsToNode::is_base_use(u)) {
3371 is_base = true;
3372 u = PointsToNode::get_use_node(u)->as_Field();
3373 }
3374 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3375 }
3376 tty->print(" ]] ");
3377 if (_node == NULL)
3378 tty->print_cr("<null>");
3379 else
3380 _node->dump();
3381 }
3382
3383 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3384 bool first = true;
3385 int ptnodes_length = ptnodes_worklist.length();
3386 for (int i = 0; i < ptnodes_length; i++) {
3387 PointsToNode *ptn = ptnodes_worklist.at(i);
3388 if (ptn == NULL || !ptn->is_JavaObject())
3389 continue;
3390 PointsToNode::EscapeState es = ptn->escape_state();
3391 if ((es != PointsToNode::NoEscape) && !Verbose) {
3392 continue;
3393 }
3394 Node* n = ptn->ideal_node();
3395 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3396 n->as_CallStaticJava()->is_boxing_method())) {
3397 if (first) {
3398 tty->cr();
3399 tty->print("======== Connection graph for ");
3400 _compile->method()->print_short_name();
3401 tty->cr();
3402 first = false;
3403 }
3404 ptn->dump();
3405 // Print all locals and fields which reference this allocation
3406 for (UseIterator j(ptn); j.has_next(); j.next()) {
3407 PointsToNode* use = j.get();
3408 if (use->is_LocalVar()) {
3409 use->dump(Verbose);
3410 } else if (Verbose) {
3411 use->dump();
3412 }
3413 }
3414 tty->cr();
3415 }
3416 }
3417 }
3418 #endif