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