1 /*
2 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "opto/c2compiler.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/compile.hpp"
34 #include "opto/escape.hpp"
35 #include "opto/phaseX.hpp"
36 #include "opto/rootnode.hpp"
37
38 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
39 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
40 _collecting(true),
41 _verify(false),
42 _compile(C),
43 _igvn(igvn),
44 _node_map(C->comp_arena()) {
45 // Add unknown java object.
46 add_java_object(C->top(), PointsToNode::GlobalEscape);
47 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
48 // Add ConP(#NULL) and ConN(#NULL) nodes.
49 Node* oop_null = igvn->zerocon(T_OBJECT);
50 assert(oop_null->_idx < nodes_size(), "should be created already");
51 add_java_object(oop_null, PointsToNode::NoEscape);
52 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
53 if (UseCompressedOops) {
54 Node* noop_null = igvn->zerocon(T_NARROWOOP);
55 assert(noop_null->_idx < nodes_size(), "should be created already");
56 map_ideal_node(noop_null, null_obj);
57 }
58 _pcmp_neq = NULL; // Should be initialized
59 _pcmp_eq = NULL;
60 }
61
62 bool ConnectionGraph::has_candidates(Compile *C) {
63 // EA brings benefits only when the code has allocations and/or locks which
64 // are represented by ideal Macro nodes.
65 int cnt = C->macro_count();
66 for( int i=0; i < cnt; i++ ) {
67 Node *n = C->macro_node(i);
68 if ( n->is_Allocate() )
69 return true;
70 if( n->is_Lock() ) {
71 Node* obj = n->as_Lock()->obj_node()->uncast();
72 if( !(obj->is_Parm() || obj->is_Con()) )
73 return true;
74 }
75 }
76 return false;
77 }
78
79 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
80 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
81 ResourceMark rm;
82
83 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
84 // to create space for them in ConnectionGraph::_nodes[].
85 Node* oop_null = igvn->zerocon(T_OBJECT);
86 Node* noop_null = igvn->zerocon(T_NARROWOOP);
87 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
88 // Perform escape analysis
89 if (congraph->compute_escape()) {
90 // There are non escaping objects.
91 C->set_congraph(congraph);
92 }
93 // Cleanup.
94 if (oop_null->outcnt() == 0)
95 igvn->hash_delete(oop_null);
96 if (noop_null->outcnt() == 0)
97 igvn->hash_delete(noop_null);
98 }
99
100 bool ConnectionGraph::compute_escape() {
101 Compile* C = _compile;
102 PhaseGVN* igvn = _igvn;
103
104 // Worklists used by EA.
105 Unique_Node_List delayed_worklist;
106 GrowableArray<Node*> alloc_worklist;
107 GrowableArray<Node*> ptr_cmp_worklist;
108 GrowableArray<Node*> storestore_worklist;
109 GrowableArray<PointsToNode*> ptnodes_worklist;
110 GrowableArray<JavaObjectNode*> java_objects_worklist;
111 GrowableArray<JavaObjectNode*> non_escaped_worklist;
112 GrowableArray<FieldNode*> oop_fields_worklist;
113 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
114
115 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
116
117 // 1. Populate Connection Graph (CG) with PointsTo nodes.
118 ideal_nodes.map(C->unique(), NULL); // preallocate space
119 // Initialize worklist
120 if (C->root() != NULL) {
121 ideal_nodes.push(C->root());
122 }
123 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
124 Node* n = ideal_nodes.at(next);
125 // Create PointsTo nodes and add them to Connection Graph. Called
126 // only once per ideal node since ideal_nodes is Unique_Node list.
127 add_node_to_connection_graph(n, &delayed_worklist);
128 PointsToNode* ptn = ptnode_adr(n->_idx);
129 if (ptn != NULL) {
130 ptnodes_worklist.append(ptn);
131 if (ptn->is_JavaObject()) {
132 java_objects_worklist.append(ptn->as_JavaObject());
133 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
134 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
135 // Only allocations and java static calls results are interesting.
136 non_escaped_worklist.append(ptn->as_JavaObject());
137 }
138 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
139 oop_fields_worklist.append(ptn->as_Field());
140 }
141 }
142 if (n->is_MergeMem()) {
143 // Collect all MergeMem nodes to add memory slices for
144 // scalar replaceable objects in split_unique_types().
145 _mergemem_worklist.append(n->as_MergeMem());
146 } else if (OptimizePtrCompare && n->is_Cmp() &&
147 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
148 // Collect compare pointers nodes.
149 ptr_cmp_worklist.append(n);
150 } else if (n->is_MemBarStoreStore()) {
151 // Collect all MemBarStoreStore nodes so that depending on the
152 // escape status of the associated Allocate node some of them
153 // may be eliminated.
154 storestore_worklist.append(n);
155 #ifdef ASSERT
156 } else if(n->is_AddP()) {
157 // Collect address nodes for graph verification.
158 addp_worklist.append(n);
159 #endif
160 }
161 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
162 Node* m = n->fast_out(i); // Get user
163 ideal_nodes.push(m);
164 }
165 }
166 if (non_escaped_worklist.length() == 0) {
167 _collecting = false;
168 return false; // Nothing to do.
169 }
170 // Add final simple edges to graph.
171 while(delayed_worklist.size() > 0) {
172 Node* n = delayed_worklist.pop();
173 add_final_edges(n);
174 }
175 int ptnodes_length = ptnodes_worklist.length();
176
177 #ifdef ASSERT
178 if (VerifyConnectionGraph) {
179 // Verify that no new simple edges could be created and all
180 // local vars has edges.
181 _verify = true;
182 for (int next = 0; next < ptnodes_length; ++next) {
183 PointsToNode* ptn = ptnodes_worklist.at(next);
184 add_final_edges(ptn->ideal_node());
185 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
186 ptn->dump();
187 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
188 }
189 }
190 _verify = false;
191 }
192 #endif
193
194 // 2. Finish Graph construction by propagating references to all
195 // java objects through graph.
196 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
197 java_objects_worklist, oop_fields_worklist)) {
198 // All objects escaped or hit time or iterations limits.
199 _collecting = false;
200 return false;
201 }
202
203 // 3. Adjust scalar_replaceable state of nonescaping objects and push
204 // scalar replaceable allocations on alloc_worklist for processing
205 // in split_unique_types().
206 int non_escaped_length = non_escaped_worklist.length();
207 for (int next = 0; next < non_escaped_length; next++) {
208 JavaObjectNode* ptn = non_escaped_worklist.at(next);
209 if (ptn->escape_state() == PointsToNode::NoEscape &&
210 ptn->scalar_replaceable()) {
211 adjust_scalar_replaceable_state(ptn);
212 if (ptn->scalar_replaceable()) {
213 alloc_worklist.append(ptn->ideal_node());
214 }
215 }
216 }
217
218 #ifdef ASSERT
219 if (VerifyConnectionGraph) {
220 // Verify that graph is complete - no new edges could be added or needed.
221 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
222 java_objects_worklist, addp_worklist);
223 }
224 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
225 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
226 null_obj->edge_count() == 0 &&
227 !null_obj->arraycopy_src() &&
228 !null_obj->arraycopy_dst(), "sanity");
229 #endif
230
231 _collecting = false;
232
233 } // TracePhase t3("connectionGraph")
234
235 // 4. Optimize ideal graph based on EA information.
236 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
237 if (has_non_escaping_obj) {
238 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
239 }
240
241 #ifndef PRODUCT
242 if (PrintEscapeAnalysis) {
243 dump(ptnodes_worklist); // Dump ConnectionGraph
244 }
245 #endif
246
247 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
248 #ifdef ASSERT
249 if (VerifyConnectionGraph) {
250 int alloc_length = alloc_worklist.length();
251 for (int next = 0; next < alloc_length; ++next) {
252 Node* n = alloc_worklist.at(next);
253 PointsToNode* ptn = ptnode_adr(n->_idx);
254 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
255 }
256 }
257 #endif
258
259 // 5. Separate memory graph for scalar replaceable allcations.
260 if (has_scalar_replaceable_candidates &&
261 C->AliasLevel() >= 3 && EliminateAllocations) {
262 // Now use the escape information to create unique types for
263 // scalar replaceable objects.
264 split_unique_types(alloc_worklist);
265 if (C->failing()) return false;
266 C->print_method(PHASE_AFTER_EA, 2);
267
268 #ifdef ASSERT
269 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
270 tty->print("=== No allocations eliminated for ");
271 C->method()->print_short_name();
272 if(!EliminateAllocations) {
273 tty->print(" since EliminateAllocations is off ===");
274 } else if(!has_scalar_replaceable_candidates) {
275 tty->print(" since there are no scalar replaceable candidates ===");
276 } else if(C->AliasLevel() < 3) {
277 tty->print(" since AliasLevel < 3 ===");
278 }
279 tty->cr();
280 #endif
281 }
282 return has_non_escaping_obj;
283 }
284
285 // Utility function for nodes that load an object
286 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
287 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
288 // ThreadLocal has RawPtr type.
289 const Type* t = _igvn->type(n);
290 if (t->make_ptr() != NULL) {
291 Node* adr = n->in(MemNode::Address);
292 #ifdef ASSERT
293 if (!adr->is_AddP()) {
294 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
295 } else {
296 assert((ptnode_adr(adr->_idx) == NULL ||
297 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
298 }
299 #endif
300 add_local_var_and_edge(n, PointsToNode::NoEscape,
301 adr, delayed_worklist);
302 }
303 }
304
305 // Populate Connection Graph with PointsTo nodes and create simple
306 // connection graph edges.
307 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
308 assert(!_verify, "this method sould not be called for verification");
309 PhaseGVN* igvn = _igvn;
310 uint n_idx = n->_idx;
311 PointsToNode* n_ptn = ptnode_adr(n_idx);
312 if (n_ptn != NULL)
313 return; // No need to redefine PointsTo node during first iteration.
314
315 if (n->is_Call()) {
316 // Arguments to allocation and locking don't escape.
317 if (n->is_AbstractLock()) {
318 // Put Lock and Unlock nodes on IGVN worklist to process them during
319 // first IGVN optimization when escape information is still available.
320 record_for_optimizer(n);
321 } else if (n->is_Allocate()) {
322 add_call_node(n->as_Call());
323 record_for_optimizer(n);
324 } else {
325 if (n->is_CallStaticJava()) {
326 const char* name = n->as_CallStaticJava()->_name;
327 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
328 return; // Skip uncommon traps
329 }
330 // Don't mark as processed since call's arguments have to be processed.
331 delayed_worklist->push(n);
332 // Check if a call returns an object.
333 if (n->as_Call()->returns_pointer() &&
334 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
335 add_call_node(n->as_Call());
336 }
337 }
338 return;
339 }
340 // Put this check here to process call arguments since some call nodes
341 // point to phantom_obj.
342 if (n_ptn == phantom_obj || n_ptn == null_obj)
343 return; // Skip predefined nodes.
344
345 int opcode = n->Opcode();
346 switch (opcode) {
347 case Op_AddP: {
348 Node* base = get_addp_base(n);
349 PointsToNode* ptn_base = ptnode_adr(base->_idx);
350 // Field nodes are created for all field types. They are used in
351 // adjust_scalar_replaceable_state() and split_unique_types().
352 // Note, non-oop fields will have only base edges in Connection
353 // Graph because such fields are not used for oop loads and stores.
354 int offset = address_offset(n, igvn);
355 add_field(n, PointsToNode::NoEscape, offset);
356 if (ptn_base == NULL) {
357 delayed_worklist->push(n); // Process it later.
358 } else {
359 n_ptn = ptnode_adr(n_idx);
360 add_base(n_ptn->as_Field(), ptn_base);
361 }
362 break;
363 }
364 case Op_CastX2P: {
365 map_ideal_node(n, phantom_obj);
366 break;
367 }
368 case Op_CastPP:
369 case Op_CheckCastPP:
370 case Op_EncodeP:
371 case Op_DecodeN: {
372 add_local_var_and_edge(n, PointsToNode::NoEscape,
373 n->in(1), delayed_worklist);
374 break;
375 }
376 case Op_CMoveP: {
377 add_local_var(n, PointsToNode::NoEscape);
378 // Do not add edges during first iteration because some could be
379 // not defined yet.
380 delayed_worklist->push(n);
381 break;
382 }
383 case Op_ConP:
384 case Op_ConN: {
385 // assume all oop constants globally escape except for null
386 PointsToNode::EscapeState es;
387 if (igvn->type(n) == TypePtr::NULL_PTR ||
388 igvn->type(n) == TypeNarrowOop::NULL_PTR) {
389 es = PointsToNode::NoEscape;
390 } else {
391 es = PointsToNode::GlobalEscape;
392 }
393 add_java_object(n, es);
394 break;
395 }
396 case Op_CreateEx: {
397 // assume that all exception objects globally escape
398 add_java_object(n, PointsToNode::GlobalEscape);
399 break;
400 }
401 case Op_LoadKlass:
402 case Op_LoadNKlass: {
403 // Unknown class is loaded
404 map_ideal_node(n, phantom_obj);
405 break;
406 }
407 case Op_LoadP:
408 case Op_LoadN:
409 case Op_LoadPLocked: {
410 add_objload_to_connection_graph(n, delayed_worklist);
411 break;
412 }
413 case Op_Parm: {
414 map_ideal_node(n, phantom_obj);
415 break;
416 }
417 case Op_PartialSubtypeCheck: {
418 // Produces Null or notNull and is used in only in CmpP so
419 // phantom_obj could be used.
420 map_ideal_node(n, phantom_obj); // Result is unknown
421 break;
422 }
423 case Op_Phi: {
424 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
425 // ThreadLocal has RawPtr type.
426 const Type* t = n->as_Phi()->type();
427 if (t->make_ptr() != NULL) {
428 add_local_var(n, PointsToNode::NoEscape);
429 // Do not add edges during first iteration because some could be
430 // not defined yet.
431 delayed_worklist->push(n);
432 }
433 break;
434 }
435 case Op_Proj: {
436 // we are only interested in the oop result projection from a call
437 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
438 n->in(0)->as_Call()->returns_pointer()) {
439 add_local_var_and_edge(n, PointsToNode::NoEscape,
440 n->in(0), delayed_worklist);
441 }
442 break;
443 }
444 case Op_Rethrow: // Exception object escapes
445 case Op_Return: {
446 if (n->req() > TypeFunc::Parms &&
447 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
448 // Treat Return value as LocalVar with GlobalEscape escape state.
449 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
450 n->in(TypeFunc::Parms), delayed_worklist);
451 }
452 break;
453 }
454 case Op_GetAndSetP:
455 case Op_GetAndSetN: {
456 add_objload_to_connection_graph(n, delayed_worklist);
457 // fallthrough
458 }
459 case Op_StoreP:
460 case Op_StoreN:
461 case Op_StorePConditional:
462 case Op_CompareAndSwapP:
463 case Op_CompareAndSwapN: {
464 Node* adr = n->in(MemNode::Address);
465 const Type *adr_type = igvn->type(adr);
466 adr_type = adr_type->make_ptr();
467 if (adr_type->isa_oopptr() ||
468 (opcode == Op_StoreP || opcode == Op_StoreN) &&
469 (adr_type == TypeRawPtr::NOTNULL &&
470 adr->in(AddPNode::Address)->is_Proj() &&
471 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
472 delayed_worklist->push(n); // Process it later.
473 #ifdef ASSERT
474 assert(adr->is_AddP(), "expecting an AddP");
475 if (adr_type == TypeRawPtr::NOTNULL) {
476 // Verify a raw address for a store captured by Initialize node.
477 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
478 assert(offs != Type::OffsetBot, "offset must be a constant");
479 }
480 #endif
481 } else {
482 // Ignore copy the displaced header to the BoxNode (OSR compilation).
483 if (adr->is_BoxLock())
484 break;
485 // Stored value escapes in unsafe access.
486 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
487 // Pointer stores in G1 barriers looks like unsafe access.
488 // Ignore such stores to be able scalar replace non-escaping
489 // allocations.
490 if (UseG1GC && adr->is_AddP()) {
491 Node* base = get_addp_base(adr);
492 if (base->Opcode() == Op_LoadP &&
493 base->in(MemNode::Address)->is_AddP()) {
494 adr = base->in(MemNode::Address);
495 Node* tls = get_addp_base(adr);
496 if (tls->Opcode() == Op_ThreadLocal) {
497 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
498 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
499 PtrQueue::byte_offset_of_buf())) {
500 break; // G1 pre barier previous oop value store.
501 }
502 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
503 PtrQueue::byte_offset_of_buf())) {
504 break; // G1 post barier card address store.
505 }
506 }
507 }
508 }
509 delayed_worklist->push(n); // Process unsafe access later.
510 break;
511 }
512 #ifdef ASSERT
513 n->dump(1);
514 assert(false, "not unsafe or G1 barrier raw StoreP");
515 #endif
516 }
517 break;
518 }
519 case Op_AryEq:
520 case Op_StrComp:
521 case Op_StrEquals:
522 case Op_StrIndexOf: {
523 add_local_var(n, PointsToNode::ArgEscape);
524 delayed_worklist->push(n); // Process it later.
525 break;
526 }
527 case Op_ThreadLocal: {
528 add_java_object(n, PointsToNode::ArgEscape);
529 break;
530 }
531 default:
532 ; // Do nothing for nodes not related to EA.
533 }
534 return;
535 }
536
537 #ifdef ASSERT
538 #define ELSE_FAIL(name) \
539 /* Should not be called for not pointer type. */ \
540 n->dump(1); \
541 assert(false, name); \
542 break;
543 #else
544 #define ELSE_FAIL(name) \
545 break;
546 #endif
547
548 // Add final simple edges to graph.
549 void ConnectionGraph::add_final_edges(Node *n) {
550 PointsToNode* n_ptn = ptnode_adr(n->_idx);
551 #ifdef ASSERT
552 if (_verify && n_ptn->is_JavaObject())
553 return; // This method does not change graph for JavaObject.
554 #endif
555
556 if (n->is_Call()) {
557 process_call_arguments(n->as_Call());
558 return;
559 }
560 assert(n->is_Store() || n->is_LoadStore() ||
561 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
562 "node should be registered already");
563 int opcode = n->Opcode();
564 switch (opcode) {
565 case Op_AddP: {
566 Node* base = get_addp_base(n);
567 PointsToNode* ptn_base = ptnode_adr(base->_idx);
568 assert(ptn_base != NULL, "field's base should be registered");
569 add_base(n_ptn->as_Field(), ptn_base);
570 break;
571 }
572 case Op_CastPP:
573 case Op_CheckCastPP:
574 case Op_EncodeP:
575 case Op_DecodeN: {
576 add_local_var_and_edge(n, PointsToNode::NoEscape,
577 n->in(1), NULL);
578 break;
579 }
580 case Op_CMoveP: {
581 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
582 Node* in = n->in(i);
583 if (in == NULL)
584 continue; // ignore NULL
585 Node* uncast_in = in->uncast();
586 if (uncast_in->is_top() || uncast_in == n)
587 continue; // ignore top or inputs which go back this node
588 PointsToNode* ptn = ptnode_adr(in->_idx);
589 assert(ptn != NULL, "node should be registered");
590 add_edge(n_ptn, ptn);
591 }
592 break;
593 }
594 case Op_LoadP:
595 case Op_LoadN:
596 case Op_LoadPLocked: {
597 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
598 // ThreadLocal has RawPtr type.
599 const Type* t = _igvn->type(n);
600 if (t->make_ptr() != NULL) {
601 Node* adr = n->in(MemNode::Address);
602 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
603 break;
604 }
605 ELSE_FAIL("Op_LoadP");
606 }
607 case Op_Phi: {
608 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
609 // ThreadLocal has RawPtr type.
610 const Type* t = n->as_Phi()->type();
611 if (t->make_ptr() != NULL) {
612 for (uint i = 1; i < n->req(); i++) {
613 Node* in = n->in(i);
614 if (in == NULL)
615 continue; // ignore NULL
616 Node* uncast_in = in->uncast();
617 if (uncast_in->is_top() || uncast_in == n)
618 continue; // ignore top or inputs which go back this node
619 PointsToNode* ptn = ptnode_adr(in->_idx);
620 assert(ptn != NULL, "node should be registered");
621 add_edge(n_ptn, ptn);
622 }
623 break;
624 }
625 ELSE_FAIL("Op_Phi");
626 }
627 case Op_Proj: {
628 // we are only interested in the oop result projection from a call
629 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
630 n->in(0)->as_Call()->returns_pointer()) {
631 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
632 break;
633 }
634 ELSE_FAIL("Op_Proj");
635 }
636 case Op_Rethrow: // Exception object escapes
637 case Op_Return: {
638 if (n->req() > TypeFunc::Parms &&
639 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
640 // Treat Return value as LocalVar with GlobalEscape escape state.
641 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
642 n->in(TypeFunc::Parms), NULL);
643 break;
644 }
645 ELSE_FAIL("Op_Return");
646 }
647 case Op_StoreP:
648 case Op_StoreN:
649 case Op_StorePConditional:
650 case Op_CompareAndSwapP:
651 case Op_CompareAndSwapN:
652 case Op_GetAndSetP:
653 case Op_GetAndSetN: {
654 Node* adr = n->in(MemNode::Address);
655 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
656 const Type* t = _igvn->type(n);
657 if (t->make_ptr() != NULL) {
658 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
659 }
660 }
661 const Type *adr_type = _igvn->type(adr);
662 adr_type = adr_type->make_ptr();
663 if (adr_type->isa_oopptr() ||
664 (opcode == Op_StoreP || opcode == Op_StoreN) &&
665 (adr_type == TypeRawPtr::NOTNULL &&
666 adr->in(AddPNode::Address)->is_Proj() &&
667 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
668 // Point Address to Value
669 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
670 assert(adr_ptn != NULL &&
671 adr_ptn->as_Field()->is_oop(), "node should be registered");
672 Node *val = n->in(MemNode::ValueIn);
673 PointsToNode* ptn = ptnode_adr(val->_idx);
674 assert(ptn != NULL, "node should be registered");
675 add_edge(adr_ptn, ptn);
676 break;
677 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
678 // Stored value escapes in unsafe access.
679 Node *val = n->in(MemNode::ValueIn);
680 PointsToNode* ptn = ptnode_adr(val->_idx);
681 assert(ptn != NULL, "node should be registered");
682 ptn->set_escape_state(PointsToNode::GlobalEscape);
683 // Add edge to object for unsafe access with offset.
684 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
685 assert(adr_ptn != NULL, "node should be registered");
686 if (adr_ptn->is_Field()) {
687 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
688 add_edge(adr_ptn, ptn);
689 }
690 break;
691 }
692 ELSE_FAIL("Op_StoreP");
693 }
694 case Op_AryEq:
695 case Op_StrComp:
696 case Op_StrEquals:
697 case Op_StrIndexOf: {
698 // char[] arrays passed to string intrinsic do not escape but
699 // they are not scalar replaceable. Adjust escape state for them.
700 // Start from in(2) edge since in(1) is memory edge.
701 for (uint i = 2; i < n->req(); i++) {
702 Node* adr = n->in(i);
703 const Type* at = _igvn->type(adr);
704 if (!adr->is_top() && at->isa_ptr()) {
705 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
706 at->isa_ptr() != NULL, "expecting a pointer");
707 if (adr->is_AddP()) {
708 adr = get_addp_base(adr);
709 }
710 PointsToNode* ptn = ptnode_adr(adr->_idx);
711 assert(ptn != NULL, "node should be registered");
712 add_edge(n_ptn, ptn);
713 }
714 }
715 break;
716 }
717 default: {
718 // This method should be called only for EA specific nodes which may
719 // miss some edges when they were created.
720 #ifdef ASSERT
721 n->dump(1);
722 #endif
723 guarantee(false, "unknown node");
724 }
725 }
726 return;
727 }
728
729 void ConnectionGraph::add_call_node(CallNode* call) {
730 assert(call->returns_pointer(), "only for call which returns pointer");
731 uint call_idx = call->_idx;
732 if (call->is_Allocate()) {
733 Node* k = call->in(AllocateNode::KlassNode);
734 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
735 assert(kt != NULL, "TypeKlassPtr required.");
736 ciKlass* cik = kt->klass();
737 PointsToNode::EscapeState es = PointsToNode::NoEscape;
738 bool scalar_replaceable = true;
739 if (call->is_AllocateArray()) {
740 if (!cik->is_array_klass()) { // StressReflectiveCode
741 es = PointsToNode::GlobalEscape;
742 } else {
743 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
744 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
745 // Not scalar replaceable if the length is not constant or too big.
746 scalar_replaceable = false;
747 }
748 }
749 } else { // Allocate instance
750 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
751 !cik->is_instance_klass() || // StressReflectiveCode
752 cik->as_instance_klass()->has_finalizer()) {
753 es = PointsToNode::GlobalEscape;
754 }
755 }
756 add_java_object(call, es);
757 PointsToNode* ptn = ptnode_adr(call_idx);
758 if (!scalar_replaceable && ptn->scalar_replaceable()) {
759 ptn->set_scalar_replaceable(false);
760 }
761 } else if (call->is_CallStaticJava()) {
762 // Call nodes could be different types:
763 //
764 // 1. CallDynamicJavaNode (what happened during call is unknown):
765 //
766 // - mapped to GlobalEscape JavaObject node if oop is returned;
767 //
768 // - all oop arguments are escaping globally;
769 //
770 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
771 //
772 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
773 //
774 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
775 // - mapped to NoEscape JavaObject node if non-escaping object allocated
776 // during call is returned;
777 // - mapped to ArgEscape LocalVar node pointed to object arguments
778 // which are returned and does not escape during call;
779 //
780 // - oop arguments escaping status is defined by bytecode analysis;
781 //
782 // For a static call, we know exactly what method is being called.
783 // Use bytecode estimator to record whether the call's return value escapes.
784 ciMethod* meth = call->as_CallJava()->method();
785 if (meth == NULL) {
786 const char* name = call->as_CallStaticJava()->_name;
787 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
788 // Returns a newly allocated unescaped object.
789 add_java_object(call, PointsToNode::NoEscape);
790 ptnode_adr(call_idx)->set_scalar_replaceable(false);
791 } else {
792 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
793 call_analyzer->copy_dependencies(_compile->dependencies());
794 if (call_analyzer->is_return_allocated()) {
795 // Returns a newly allocated unescaped object, simply
796 // update dependency information.
797 // Mark it as NoEscape so that objects referenced by
798 // it's fields will be marked as NoEscape at least.
799 add_java_object(call, PointsToNode::NoEscape);
800 ptnode_adr(call_idx)->set_scalar_replaceable(false);
801 } else {
802 // Determine whether any arguments are returned.
803 const TypeTuple* d = call->tf()->domain();
804 bool ret_arg = false;
805 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
806 if (d->field_at(i)->isa_ptr() != NULL &&
807 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
808 ret_arg = true;
809 break;
810 }
811 }
812 if (ret_arg) {
813 add_local_var(call, PointsToNode::ArgEscape);
814 } else {
815 // Returns unknown object.
816 map_ideal_node(call, phantom_obj);
817 }
818 }
819 }
820 } else {
821 // An other type of call, assume the worst case:
822 // returned value is unknown and globally escapes.
823 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
824 map_ideal_node(call, phantom_obj);
825 }
826 }
827
828 void ConnectionGraph::process_call_arguments(CallNode *call) {
829 bool is_arraycopy = false;
830 switch (call->Opcode()) {
831 #ifdef ASSERT
832 case Op_Allocate:
833 case Op_AllocateArray:
834 case Op_Lock:
835 case Op_Unlock:
836 assert(false, "should be done already");
837 break;
838 #endif
839 case Op_CallLeafNoFP:
840 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
841 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
842 // fall through
843 case Op_CallLeaf: {
844 // Stub calls, objects do not escape but they are not scale replaceable.
845 // Adjust escape state for outgoing arguments.
846 const TypeTuple * d = call->tf()->domain();
847 bool src_has_oops = false;
848 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
849 const Type* at = d->field_at(i);
850 Node *arg = call->in(i);
851 const Type *aat = _igvn->type(arg);
852 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
853 continue;
854 if (arg->is_AddP()) {
855 //
856 // The inline_native_clone() case when the arraycopy stub is called
857 // after the allocation before Initialize and CheckCastPP nodes.
858 // Or normal arraycopy for object arrays case.
859 //
860 // Set AddP's base (Allocate) as not scalar replaceable since
861 // pointer to the base (with offset) is passed as argument.
862 //
863 arg = get_addp_base(arg);
864 }
865 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
866 assert(arg_ptn != NULL, "should be registered");
867 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
868 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
869 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
870 aat->isa_ptr() != NULL, "expecting an Ptr");
871 bool arg_has_oops = aat->isa_oopptr() &&
872 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
873 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
874 if (i == TypeFunc::Parms) {
875 src_has_oops = arg_has_oops;
876 }
877 //
878 // src or dst could be j.l.Object when other is basic type array:
879 //
880 // arraycopy(char[],0,Object*,0,size);
881 // arraycopy(Object*,0,char[],0,size);
882 //
883 // Don't add edges in such cases.
884 //
885 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
886 arg_has_oops && (i > TypeFunc::Parms);
887 #ifdef ASSERT
888 if (!(is_arraycopy ||
889 (call->as_CallLeaf()->_name != NULL &&
890 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
891 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
892 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
893 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
894 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
895 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0)
896 ))) {
897 call->dump();
898 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
899 }
900 #endif
901 // Always process arraycopy's destination object since
902 // we need to add all possible edges to references in
903 // source object.
904 if (arg_esc >= PointsToNode::ArgEscape &&
905 !arg_is_arraycopy_dest) {
906 continue;
907 }
908 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
909 if (arg_is_arraycopy_dest) {
910 Node* src = call->in(TypeFunc::Parms);
911 if (src->is_AddP()) {
912 src = get_addp_base(src);
913 }
914 PointsToNode* src_ptn = ptnode_adr(src->_idx);
915 assert(src_ptn != NULL, "should be registered");
916 if (arg_ptn != src_ptn) {
917 // Special arraycopy edge:
918 // A destination object's field can't have the source object
919 // as base since objects escape states are not related.
920 // Only escape state of destination object's fields affects
921 // escape state of fields in source object.
922 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
923 }
924 }
925 }
926 }
927 break;
928 }
929 case Op_CallStaticJava: {
930 // For a static call, we know exactly what method is being called.
931 // Use bytecode estimator to record the call's escape affects
932 #ifdef ASSERT
933 const char* name = call->as_CallStaticJava()->_name;
934 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
935 #endif
936 ciMethod* meth = call->as_CallJava()->method();
937 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
938 // fall-through if not a Java method or no analyzer information
939 if (call_analyzer != NULL) {
940 PointsToNode* call_ptn = ptnode_adr(call->_idx);
941 const TypeTuple* d = call->tf()->domain();
942 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
943 const Type* at = d->field_at(i);
944 int k = i - TypeFunc::Parms;
945 Node* arg = call->in(i);
946 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
947 if (at->isa_ptr() != NULL &&
948 call_analyzer->is_arg_returned(k)) {
949 // The call returns arguments.
950 if (call_ptn != NULL) { // Is call's result used?
951 assert(call_ptn->is_LocalVar(), "node should be registered");
952 assert(arg_ptn != NULL, "node should be registered");
953 add_edge(call_ptn, arg_ptn);
954 }
955 }
956 if (at->isa_oopptr() != NULL &&
957 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
958 if (!call_analyzer->is_arg_stack(k)) {
959 // The argument global escapes
960 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
961 } else {
962 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
963 if (!call_analyzer->is_arg_local(k)) {
964 // The argument itself doesn't escape, but any fields might
965 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
966 }
967 }
968 }
969 }
970 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
971 // The call returns arguments.
972 assert(call_ptn->edge_count() > 0, "sanity");
973 if (!call_analyzer->is_return_local()) {
974 // Returns also unknown object.
975 add_edge(call_ptn, phantom_obj);
976 }
977 }
978 break;
979 }
980 }
981 default: {
982 // Fall-through here if not a Java method or no analyzer information
983 // or some other type of call, assume the worst case: all arguments
984 // globally escape.
985 const TypeTuple* d = call->tf()->domain();
986 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
987 const Type* at = d->field_at(i);
988 if (at->isa_oopptr() != NULL) {
989 Node* arg = call->in(i);
990 if (arg->is_AddP()) {
991 arg = get_addp_base(arg);
992 }
993 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
994 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
995 }
996 }
997 }
998 }
999 }
1000
1001
1002 // Finish Graph construction.
1003 bool ConnectionGraph::complete_connection_graph(
1004 GrowableArray<PointsToNode*>& ptnodes_worklist,
1005 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1006 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1007 GrowableArray<FieldNode*>& oop_fields_worklist) {
1008 // Normally only 1-3 passes needed to build Connection Graph depending
1009 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1010 // Set limit to 20 to catch situation when something did go wrong and
1011 // bailout Escape Analysis.
1012 // Also limit build time to 30 sec (60 in debug VM).
1013 #define CG_BUILD_ITER_LIMIT 20
1014 #ifdef ASSERT
1015 #define CG_BUILD_TIME_LIMIT 60.0
1016 #else
1017 #define CG_BUILD_TIME_LIMIT 30.0
1018 #endif
1019
1020 // Propagate GlobalEscape and ArgEscape escape states and check that
1021 // we still have non-escaping objects. The method pushs on _worklist
1022 // Field nodes which reference phantom_object.
1023 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1024 return false; // Nothing to do.
1025 }
1026 // Now propagate references to all JavaObject nodes.
1027 int java_objects_length = java_objects_worklist.length();
1028 elapsedTimer time;
1029 int new_edges = 1;
1030 int iterations = 0;
1031 do {
1032 while ((new_edges > 0) &&
1033 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1034 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1035 time.start();
1036 new_edges = 0;
1037 // Propagate references to phantom_object for nodes pushed on _worklist
1038 // by find_non_escaped_objects() and find_field_value().
1039 new_edges += add_java_object_edges(phantom_obj, false);
1040 for (int next = 0; next < java_objects_length; ++next) {
1041 JavaObjectNode* ptn = java_objects_worklist.at(next);
1042 new_edges += add_java_object_edges(ptn, true);
1043 }
1044 if (new_edges > 0) {
1045 // Update escape states on each iteration if graph was updated.
1046 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1047 return false; // Nothing to do.
1048 }
1049 }
1050 time.stop();
1051 }
1052 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1053 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1054 time.start();
1055 // Find fields which have unknown value.
1056 int fields_length = oop_fields_worklist.length();
1057 for (int next = 0; next < fields_length; next++) {
1058 FieldNode* field = oop_fields_worklist.at(next);
1059 if (field->edge_count() == 0) {
1060 new_edges += find_field_value(field);
1061 // This code may added new edges to phantom_object.
1062 // Need an other cycle to propagate references to phantom_object.
1063 }
1064 }
1065 time.stop();
1066 } else {
1067 new_edges = 0; // Bailout
1068 }
1069 } while (new_edges > 0);
1070
1071 // Bailout if passed limits.
1072 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1073 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1074 Compile* C = _compile;
1075 if (C->log() != NULL) {
1076 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1077 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1078 C->log()->end_elem(" limit'");
1079 }
1080 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1081 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1082 // Possible infinite build_connection_graph loop,
1083 // bailout (no changes to ideal graph were made).
1084 return false;
1085 }
1086 #ifdef ASSERT
1087 if (Verbose && PrintEscapeAnalysis) {
1088 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1089 iterations, nodes_size(), ptnodes_worklist.length());
1090 }
1091 #endif
1092
1093 #undef CG_BUILD_ITER_LIMIT
1094 #undef CG_BUILD_TIME_LIMIT
1095
1096 // Find fields initialized by NULL for non-escaping Allocations.
1097 int non_escaped_length = non_escaped_worklist.length();
1098 for (int next = 0; next < non_escaped_length; next++) {
1099 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1100 PointsToNode::EscapeState es = ptn->escape_state();
1101 assert(es <= PointsToNode::ArgEscape, "sanity");
1102 if (es == PointsToNode::NoEscape) {
1103 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1104 // Adding references to NULL object does not change escape states
1105 // since it does not escape. Also no fields are added to NULL object.
1106 add_java_object_edges(null_obj, false);
1107 }
1108 }
1109 Node* n = ptn->ideal_node();
1110 if (n->is_Allocate()) {
1111 // The object allocated by this Allocate node will never be
1112 // seen by an other thread. Mark it so that when it is
1113 // expanded no MemBarStoreStore is added.
1114 InitializeNode* ini = n->as_Allocate()->initialization();
1115 if (ini != NULL)
1116 ini->set_does_not_escape();
1117 }
1118 }
1119 return true; // Finished graph construction.
1120 }
1121
1122 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1123 // and check that we still have non-escaping java objects.
1124 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1125 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1126 GrowableArray<PointsToNode*> escape_worklist;
1127 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1128 int ptnodes_length = ptnodes_worklist.length();
1129 for (int next = 0; next < ptnodes_length; ++next) {
1130 PointsToNode* ptn = ptnodes_worklist.at(next);
1131 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1132 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1133 escape_worklist.push(ptn);
1134 }
1135 }
1136 // Set escape states to referenced nodes (edges list).
1137 while (escape_worklist.length() > 0) {
1138 PointsToNode* ptn = escape_worklist.pop();
1139 PointsToNode::EscapeState es = ptn->escape_state();
1140 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1141 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1142 es >= PointsToNode::ArgEscape) {
1143 // GlobalEscape or ArgEscape state of field means it has unknown value.
1144 if (add_edge(ptn, phantom_obj)) {
1145 // New edge was added
1146 add_field_uses_to_worklist(ptn->as_Field());
1147 }
1148 }
1149 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1150 PointsToNode* e = i.get();
1151 if (e->is_Arraycopy()) {
1152 assert(ptn->arraycopy_dst(), "sanity");
1153 // Propagate only fields escape state through arraycopy edge.
1154 if (e->fields_escape_state() < field_es) {
1155 set_fields_escape_state(e, field_es);
1156 escape_worklist.push(e);
1157 }
1158 } else if (es >= field_es) {
1159 // fields_escape_state is also set to 'es' if it is less than 'es'.
1160 if (e->escape_state() < es) {
1161 set_escape_state(e, es);
1162 escape_worklist.push(e);
1163 }
1164 } else {
1165 // Propagate field escape state.
1166 bool es_changed = false;
1167 if (e->fields_escape_state() < field_es) {
1168 set_fields_escape_state(e, field_es);
1169 es_changed = true;
1170 }
1171 if ((e->escape_state() < field_es) &&
1172 e->is_Field() && ptn->is_JavaObject() &&
1173 e->as_Field()->is_oop()) {
1174 // Change escape state of referenced fileds.
1175 set_escape_state(e, field_es);
1176 es_changed = true;;
1177 } else if (e->escape_state() < es) {
1178 set_escape_state(e, es);
1179 es_changed = true;;
1180 }
1181 if (es_changed) {
1182 escape_worklist.push(e);
1183 }
1184 }
1185 }
1186 }
1187 // Remove escaped objects from non_escaped list.
1188 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1189 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1190 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1191 non_escaped_worklist.delete_at(next);
1192 }
1193 if (ptn->escape_state() == PointsToNode::NoEscape) {
1194 // Find fields in non-escaped allocations which have unknown value.
1195 find_init_values(ptn, phantom_obj, NULL);
1196 }
1197 }
1198 return (non_escaped_worklist.length() > 0);
1199 }
1200
1201 // Add all references to JavaObject node by walking over all uses.
1202 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1203 int new_edges = 0;
1204 if (populate_worklist) {
1205 // Populate _worklist by uses of jobj's uses.
1206 for (UseIterator i(jobj); i.has_next(); i.next()) {
1207 PointsToNode* use = i.get();
1208 if (use->is_Arraycopy())
1209 continue;
1210 add_uses_to_worklist(use);
1211 if (use->is_Field() && use->as_Field()->is_oop()) {
1212 // Put on worklist all field's uses (loads) and
1213 // related field nodes (same base and offset).
1214 add_field_uses_to_worklist(use->as_Field());
1215 }
1216 }
1217 }
1218 while(_worklist.length() > 0) {
1219 PointsToNode* use = _worklist.pop();
1220 if (PointsToNode::is_base_use(use)) {
1221 // Add reference from jobj to field and from field to jobj (field's base).
1222 use = PointsToNode::get_use_node(use)->as_Field();
1223 if (add_base(use->as_Field(), jobj)) {
1224 new_edges++;
1225 }
1226 continue;
1227 }
1228 assert(!use->is_JavaObject(), "sanity");
1229 if (use->is_Arraycopy()) {
1230 if (jobj == null_obj) // NULL object does not have field edges
1231 continue;
1232 // Added edge from Arraycopy node to arraycopy's source java object
1233 if (add_edge(use, jobj)) {
1234 jobj->set_arraycopy_src();
1235 new_edges++;
1236 }
1237 // and stop here.
1238 continue;
1239 }
1240 if (!add_edge(use, jobj))
1241 continue; // No new edge added, there was such edge already.
1242 new_edges++;
1243 if (use->is_LocalVar()) {
1244 add_uses_to_worklist(use);
1245 if (use->arraycopy_dst()) {
1246 for (EdgeIterator i(use); i.has_next(); i.next()) {
1247 PointsToNode* e = i.get();
1248 if (e->is_Arraycopy()) {
1249 if (jobj == null_obj) // NULL object does not have field edges
1250 continue;
1251 // Add edge from arraycopy's destination java object to Arraycopy node.
1252 if (add_edge(jobj, e)) {
1253 new_edges++;
1254 jobj->set_arraycopy_dst();
1255 }
1256 }
1257 }
1258 }
1259 } else {
1260 // Added new edge to stored in field values.
1261 // Put on worklist all field's uses (loads) and
1262 // related field nodes (same base and offset).
1263 add_field_uses_to_worklist(use->as_Field());
1264 }
1265 }
1266 return new_edges;
1267 }
1268
1269 // Put on worklist all related field nodes.
1270 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1271 assert(field->is_oop(), "sanity");
1272 int offset = field->offset();
1273 add_uses_to_worklist(field);
1274 // Loop over all bases of this field and push on worklist Field nodes
1275 // with the same offset and base (since they may reference the same field).
1276 for (BaseIterator i(field); i.has_next(); i.next()) {
1277 PointsToNode* base = i.get();
1278 add_fields_to_worklist(field, base);
1279 // Check if the base was source object of arraycopy and go over arraycopy's
1280 // destination objects since values stored to a field of source object are
1281 // accessable by uses (loads) of fields of destination objects.
1282 if (base->arraycopy_src()) {
1283 for (UseIterator j(base); j.has_next(); j.next()) {
1284 PointsToNode* arycp = j.get();
1285 if (arycp->is_Arraycopy()) {
1286 for (UseIterator k(arycp); k.has_next(); k.next()) {
1287 PointsToNode* abase = k.get();
1288 if (abase->arraycopy_dst() && abase != base) {
1289 // Look for the same arracopy reference.
1290 add_fields_to_worklist(field, abase);
1291 }
1292 }
1293 }
1294 }
1295 }
1296 }
1297 }
1298
1299 // Put on worklist all related field nodes.
1300 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1301 int offset = field->offset();
1302 if (base->is_LocalVar()) {
1303 for (UseIterator j(base); j.has_next(); j.next()) {
1304 PointsToNode* f = j.get();
1305 if (PointsToNode::is_base_use(f)) { // Field
1306 f = PointsToNode::get_use_node(f);
1307 if (f == field || !f->as_Field()->is_oop())
1308 continue;
1309 int offs = f->as_Field()->offset();
1310 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1311 add_to_worklist(f);
1312 }
1313 }
1314 }
1315 } else {
1316 assert(base->is_JavaObject(), "sanity");
1317 if (// Skip phantom_object since it is only used to indicate that
1318 // this field's content globally escapes.
1319 (base != phantom_obj) &&
1320 // NULL object node does not have fields.
1321 (base != null_obj)) {
1322 for (EdgeIterator i(base); i.has_next(); i.next()) {
1323 PointsToNode* f = i.get();
1324 // Skip arraycopy edge since store to destination object field
1325 // does not update value in source object field.
1326 if (f->is_Arraycopy()) {
1327 assert(base->arraycopy_dst(), "sanity");
1328 continue;
1329 }
1330 if (f == field || !f->as_Field()->is_oop())
1331 continue;
1332 int offs = f->as_Field()->offset();
1333 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1334 add_to_worklist(f);
1335 }
1336 }
1337 }
1338 }
1339 }
1340
1341 // Find fields which have unknown value.
1342 int ConnectionGraph::find_field_value(FieldNode* field) {
1343 // Escaped fields should have init value already.
1344 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1345 int new_edges = 0;
1346 for (BaseIterator i(field); i.has_next(); i.next()) {
1347 PointsToNode* base = i.get();
1348 if (base->is_JavaObject()) {
1349 // Skip Allocate's fields which will be processed later.
1350 if (base->ideal_node()->is_Allocate())
1351 return 0;
1352 assert(base == null_obj, "only NULL ptr base expected here");
1353 }
1354 }
1355 if (add_edge(field, phantom_obj)) {
1356 // New edge was added
1357 new_edges++;
1358 add_field_uses_to_worklist(field);
1359 }
1360 return new_edges;
1361 }
1362
1363 // Find fields initializing values for allocations.
1364 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1365 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1366 int new_edges = 0;
1367 Node* alloc = pta->ideal_node();
1368 if (init_val == phantom_obj) {
1369 // Do nothing for Allocate nodes since its fields values are "known".
1370 if (alloc->is_Allocate())
1371 return 0;
1372 assert(alloc->as_CallStaticJava(), "sanity");
1373 #ifdef ASSERT
1374 if (alloc->as_CallStaticJava()->method() == NULL) {
1375 const char* name = alloc->as_CallStaticJava()->_name;
1376 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1377 }
1378 #endif
1379 // Non-escaped allocation returned from Java or runtime call have
1380 // unknown values in fields.
1381 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1382 PointsToNode* field = i.get();
1383 if (field->is_Field() && field->as_Field()->is_oop()) {
1384 if (add_edge(field, phantom_obj)) {
1385 // New edge was added
1386 new_edges++;
1387 add_field_uses_to_worklist(field->as_Field());
1388 }
1389 }
1390 }
1391 return new_edges;
1392 }
1393 assert(init_val == null_obj, "sanity");
1394 // Do nothing for Call nodes since its fields values are unknown.
1395 if (!alloc->is_Allocate())
1396 return 0;
1397
1398 InitializeNode* ini = alloc->as_Allocate()->initialization();
1399 Compile* C = _compile;
1400 bool visited_bottom_offset = false;
1401 GrowableArray<int> offsets_worklist;
1402
1403 // Check if an oop field's initializing value is recorded and add
1404 // a corresponding NULL if field's value if it is not recorded.
1405 // Connection Graph does not record a default initialization by NULL
1406 // captured by Initialize node.
1407 //
1408 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1409 PointsToNode* field = i.get(); // Field (AddP)
1410 if (!field->is_Field() || !field->as_Field()->is_oop())
1411 continue; // Not oop field
1412 int offset = field->as_Field()->offset();
1413 if (offset == Type::OffsetBot) {
1414 if (!visited_bottom_offset) {
1415 // OffsetBot is used to reference array's element,
1416 // always add reference to NULL to all Field nodes since we don't
1417 // known which element is referenced.
1418 if (add_edge(field, null_obj)) {
1419 // New edge was added
1420 new_edges++;
1421 add_field_uses_to_worklist(field->as_Field());
1422 visited_bottom_offset = true;
1423 }
1424 }
1425 } else {
1426 // Check only oop fields.
1427 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1428 if (adr_type->isa_rawptr()) {
1429 #ifdef ASSERT
1430 // Raw pointers are used for initializing stores so skip it
1431 // since it should be recorded already
1432 Node* base = get_addp_base(field->ideal_node());
1433 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1434 (base->in(0) == alloc),"unexpected pointer type");
1435 #endif
1436 continue;
1437 }
1438 if (!offsets_worklist.contains(offset)) {
1439 offsets_worklist.append(offset);
1440 Node* value = NULL;
1441 if (ini != NULL) {
1442 // StoreP::memory_type() == T_ADDRESS
1443 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1444 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1445 // Make sure initializing store has the same type as this AddP.
1446 // This AddP may reference non existing field because it is on a
1447 // dead branch of bimorphic call which is not eliminated yet.
1448 if (store != NULL && store->is_Store() &&
1449 store->as_Store()->memory_type() == ft) {
1450 value = store->in(MemNode::ValueIn);
1451 #ifdef ASSERT
1452 if (VerifyConnectionGraph) {
1453 // Verify that AddP already points to all objects the value points to.
1454 PointsToNode* val = ptnode_adr(value->_idx);
1455 assert((val != NULL), "should be processed already");
1456 PointsToNode* missed_obj = NULL;
1457 if (val->is_JavaObject()) {
1458 if (!field->points_to(val->as_JavaObject())) {
1459 missed_obj = val;
1460 }
1461 } else {
1462 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1463 tty->print_cr("----------init store has invalid value -----");
1464 store->dump();
1465 val->dump();
1466 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1467 }
1468 for (EdgeIterator j(val); j.has_next(); j.next()) {
1469 PointsToNode* obj = j.get();
1470 if (obj->is_JavaObject()) {
1471 if (!field->points_to(obj->as_JavaObject())) {
1472 missed_obj = obj;
1473 break;
1474 }
1475 }
1476 }
1477 }
1478 if (missed_obj != NULL) {
1479 tty->print_cr("----------field---------------------------------");
1480 field->dump();
1481 tty->print_cr("----------missed referernce to object-----------");
1482 missed_obj->dump();
1483 tty->print_cr("----------object referernced by init store -----");
1484 store->dump();
1485 val->dump();
1486 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1487 }
1488 }
1489 #endif
1490 } else {
1491 // There could be initializing stores which follow allocation.
1492 // For example, a volatile field store is not collected
1493 // by Initialize node.
1494 //
1495 // Need to check for dependent loads to separate such stores from
1496 // stores which follow loads. For now, add initial value NULL so
1497 // that compare pointers optimization works correctly.
1498 }
1499 }
1500 if (value == NULL) {
1501 // A field's initializing value was not recorded. Add NULL.
1502 if (add_edge(field, null_obj)) {
1503 // New edge was added
1504 new_edges++;
1505 add_field_uses_to_worklist(field->as_Field());
1506 }
1507 }
1508 }
1509 }
1510 }
1511 return new_edges;
1512 }
1513
1514 // Adjust scalar_replaceable state after Connection Graph is built.
1515 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1516 // Search for non-escaping objects which are not scalar replaceable
1517 // and mark them to propagate the state to referenced objects.
1518
1519 // 1. An object is not scalar replaceable if the field into which it is
1520 // stored has unknown offset (stored into unknown element of an array).
1521 //
1522 for (UseIterator i(jobj); i.has_next(); i.next()) {
1523 PointsToNode* use = i.get();
1524 assert(!use->is_Arraycopy(), "sanity");
1525 if (use->is_Field()) {
1526 FieldNode* field = use->as_Field();
1527 assert(field->is_oop() && field->scalar_replaceable() &&
1528 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1529 if (field->offset() == Type::OffsetBot) {
1530 jobj->set_scalar_replaceable(false);
1531 return;
1532 }
1533 }
1534 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1535 // 2. An object is not scalar replaceable if it is merged with other objects.
1536 for (EdgeIterator j(use); j.has_next(); j.next()) {
1537 PointsToNode* ptn = j.get();
1538 if (ptn->is_JavaObject() && ptn != jobj) {
1539 // Mark all objects.
1540 jobj->set_scalar_replaceable(false);
1541 ptn->set_scalar_replaceable(false);
1542 }
1543 }
1544 if (!jobj->scalar_replaceable()) {
1545 return;
1546 }
1547 }
1548
1549 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1550 // Non-escaping object node should point only to field nodes.
1551 FieldNode* field = j.get()->as_Field();
1552 int offset = field->as_Field()->offset();
1553
1554 // 3. An object is not scalar replaceable if it has a field with unknown
1555 // offset (array's element is accessed in loop).
1556 if (offset == Type::OffsetBot) {
1557 jobj->set_scalar_replaceable(false);
1558 return;
1559 }
1560 // 4. Currently an object is not scalar replaceable if a LoadStore node
1561 // access its field since the field value is unknown after it.
1562 //
1563 Node* n = field->ideal_node();
1564 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1565 if (n->fast_out(i)->is_LoadStore()) {
1566 jobj->set_scalar_replaceable(false);
1567 return;
1568 }
1569 }
1570
1571 // 5. Or the address may point to more then one object. This may produce
1572 // the false positive result (set not scalar replaceable)
1573 // since the flow-insensitive escape analysis can't separate
1574 // the case when stores overwrite the field's value from the case
1575 // when stores happened on different control branches.
1576 //
1577 // Note: it will disable scalar replacement in some cases:
1578 //
1579 // Point p[] = new Point[1];
1580 // p[0] = new Point(); // Will be not scalar replaced
1581 //
1582 // but it will save us from incorrect optimizations in next cases:
1583 //
1584 // Point p[] = new Point[1];
1585 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1586 //
1587 if (field->base_count() > 1) {
1588 for (BaseIterator i(field); i.has_next(); i.next()) {
1589 PointsToNode* base = i.get();
1590 // Don't take into account LocalVar nodes which
1591 // may point to only one object which should be also
1592 // this field's base by now.
1593 if (base->is_JavaObject() && base != jobj) {
1594 // Mark all bases.
1595 jobj->set_scalar_replaceable(false);
1596 base->set_scalar_replaceable(false);
1597 }
1598 }
1599 }
1600 }
1601 }
1602
1603 #ifdef ASSERT
1604 void ConnectionGraph::verify_connection_graph(
1605 GrowableArray<PointsToNode*>& ptnodes_worklist,
1606 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1607 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1608 GrowableArray<Node*>& addp_worklist) {
1609 // Verify that graph is complete - no new edges could be added.
1610 int java_objects_length = java_objects_worklist.length();
1611 int non_escaped_length = non_escaped_worklist.length();
1612 int new_edges = 0;
1613 for (int next = 0; next < java_objects_length; ++next) {
1614 JavaObjectNode* ptn = java_objects_worklist.at(next);
1615 new_edges += add_java_object_edges(ptn, true);
1616 }
1617 assert(new_edges == 0, "graph was not complete");
1618 // Verify that escape state is final.
1619 int length = non_escaped_worklist.length();
1620 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1621 assert((non_escaped_length == non_escaped_worklist.length()) &&
1622 (non_escaped_length == length) &&
1623 (_worklist.length() == 0), "escape state was not final");
1624
1625 // Verify fields information.
1626 int addp_length = addp_worklist.length();
1627 for (int next = 0; next < addp_length; ++next ) {
1628 Node* n = addp_worklist.at(next);
1629 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1630 if (field->is_oop()) {
1631 // Verify that field has all bases
1632 Node* base = get_addp_base(n);
1633 PointsToNode* ptn = ptnode_adr(base->_idx);
1634 if (ptn->is_JavaObject()) {
1635 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1636 } else {
1637 assert(ptn->is_LocalVar(), "sanity");
1638 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1639 PointsToNode* e = i.get();
1640 if (e->is_JavaObject()) {
1641 assert(field->has_base(e->as_JavaObject()), "sanity");
1642 }
1643 }
1644 }
1645 // Verify that all fields have initializing values.
1646 if (field->edge_count() == 0) {
1647 tty->print_cr("----------field does not have references----------");
1648 field->dump();
1649 for (BaseIterator i(field); i.has_next(); i.next()) {
1650 PointsToNode* base = i.get();
1651 tty->print_cr("----------field has next base---------------------");
1652 base->dump();
1653 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1654 tty->print_cr("----------base has fields-------------------------");
1655 for (EdgeIterator j(base); j.has_next(); j.next()) {
1656 j.get()->dump();
1657 }
1658 tty->print_cr("----------base has references---------------------");
1659 for (UseIterator j(base); j.has_next(); j.next()) {
1660 j.get()->dump();
1661 }
1662 }
1663 }
1664 for (UseIterator i(field); i.has_next(); i.next()) {
1665 i.get()->dump();
1666 }
1667 assert(field->edge_count() > 0, "sanity");
1668 }
1669 }
1670 }
1671 }
1672 #endif
1673
1674 // Optimize ideal graph.
1675 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1676 GrowableArray<Node*>& storestore_worklist) {
1677 Compile* C = _compile;
1678 PhaseIterGVN* igvn = _igvn;
1679 if (EliminateLocks) {
1680 // Mark locks before changing ideal graph.
1681 int cnt = C->macro_count();
1682 for( int i=0; i < cnt; i++ ) {
1683 Node *n = C->macro_node(i);
1684 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1685 AbstractLockNode* alock = n->as_AbstractLock();
1686 if (!alock->is_non_esc_obj()) {
1687 if (not_global_escape(alock->obj_node())) {
1688 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1689 // The lock could be marked eliminated by lock coarsening
1690 // code during first IGVN before EA. Replace coarsened flag
1691 // to eliminate all associated locks/unlocks.
1692 alock->set_non_esc_obj();
1693 }
1694 }
1695 }
1696 }
1697 }
1698
1699 if (OptimizePtrCompare) {
1700 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1701 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1702 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1703 // Optimize objects compare.
1704 while (ptr_cmp_worklist.length() != 0) {
1705 Node *n = ptr_cmp_worklist.pop();
1706 Node *res = optimize_ptr_compare(n);
1707 if (res != NULL) {
1708 #ifndef PRODUCT
1709 if (PrintOptimizePtrCompare) {
1710 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"));
1711 if (Verbose) {
1712 n->dump(1);
1713 }
1714 }
1715 #endif
1716 igvn->replace_node(n, res);
1717 }
1718 }
1719 // cleanup
1720 if (_pcmp_neq->outcnt() == 0)
1721 igvn->hash_delete(_pcmp_neq);
1722 if (_pcmp_eq->outcnt() == 0)
1723 igvn->hash_delete(_pcmp_eq);
1724 }
1725
1726 // For MemBarStoreStore nodes added in library_call.cpp, check
1727 // escape status of associated AllocateNode and optimize out
1728 // MemBarStoreStore node if the allocated object never escapes.
1729 while (storestore_worklist.length() != 0) {
1730 Node *n = storestore_worklist.pop();
1731 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1732 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1733 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1734 if (not_global_escape(alloc)) {
1735 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1736 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1737 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1738 igvn->register_new_node_with_optimizer(mb);
1739 igvn->replace_node(storestore, mb);
1740 }
1741 }
1742 }
1743
1744 // Optimize objects compare.
1745 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1746 assert(OptimizePtrCompare, "sanity");
1747 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1748 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1749 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1750 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1751 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1752 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1753
1754 // Check simple cases first.
1755 if (jobj1 != NULL) {
1756 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1757 if (jobj1 == jobj2) {
1758 // Comparing the same not escaping object.
1759 return _pcmp_eq;
1760 }
1761 Node* obj = jobj1->ideal_node();
1762 // Comparing not escaping allocation.
1763 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1764 !ptn2->points_to(jobj1)) {
1765 return _pcmp_neq; // This includes nullness check.
1766 }
1767 }
1768 }
1769 if (jobj2 != NULL) {
1770 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1771 Node* obj = jobj2->ideal_node();
1772 // Comparing not escaping allocation.
1773 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1774 !ptn1->points_to(jobj2)) {
1775 return _pcmp_neq; // This includes nullness check.
1776 }
1777 }
1778 }
1779 if (jobj1 != NULL && jobj1 != phantom_obj &&
1780 jobj2 != NULL && jobj2 != phantom_obj &&
1781 jobj1->ideal_node()->is_Con() &&
1782 jobj2->ideal_node()->is_Con()) {
1783 // Klass or String constants compare. Need to be careful with
1784 // compressed pointers - compare types of ConN and ConP instead of nodes.
1785 const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr();
1786 const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr();
1787 assert(t1 != NULL && t2 != NULL, "sanity");
1788 if (t1->make_ptr() == t2->make_ptr()) {
1789 return _pcmp_eq;
1790 } else {
1791 return _pcmp_neq;
1792 }
1793 }
1794 if (ptn1->meet(ptn2)) {
1795 return NULL; // Sets are not disjoint
1796 }
1797
1798 // Sets are disjoint.
1799 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1800 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1801 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1802 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1803 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1804 set2_has_unknown_ptr && set1_has_null_ptr) {
1805 // Check nullness of unknown object.
1806 return NULL;
1807 }
1808
1809 // Disjointness by itself is not sufficient since
1810 // alias analysis is not complete for escaped objects.
1811 // Disjoint sets are definitely unrelated only when
1812 // at least one set has only not escaping allocations.
1813 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1814 if (ptn1->non_escaping_allocation()) {
1815 return _pcmp_neq;
1816 }
1817 }
1818 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1819 if (ptn2->non_escaping_allocation()) {
1820 return _pcmp_neq;
1821 }
1822 }
1823 return NULL;
1824 }
1825
1826 // Connection Graph constuction functions.
1827
1828 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1829 PointsToNode* ptadr = _nodes.at(n->_idx);
1830 if (ptadr != NULL) {
1831 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1832 return;
1833 }
1834 Compile* C = _compile;
1835 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1836 _nodes.at_put(n->_idx, ptadr);
1837 }
1838
1839 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1840 PointsToNode* ptadr = _nodes.at(n->_idx);
1841 if (ptadr != NULL) {
1842 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1843 return;
1844 }
1845 Compile* C = _compile;
1846 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1847 _nodes.at_put(n->_idx, ptadr);
1848 }
1849
1850 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1851 PointsToNode* ptadr = _nodes.at(n->_idx);
1852 if (ptadr != NULL) {
1853 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1854 return;
1855 }
1856 bool unsafe = false;
1857 bool is_oop = is_oop_field(n, offset, &unsafe);
1858 if (unsafe) {
1859 es = PointsToNode::GlobalEscape;
1860 }
1861 Compile* C = _compile;
1862 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1863 _nodes.at_put(n->_idx, field);
1864 }
1865
1866 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1867 PointsToNode* src, PointsToNode* dst) {
1868 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1869 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1870 PointsToNode* ptadr = _nodes.at(n->_idx);
1871 if (ptadr != NULL) {
1872 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1873 return;
1874 }
1875 Compile* C = _compile;
1876 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1877 _nodes.at_put(n->_idx, ptadr);
1878 // Add edge from arraycopy node to source object.
1879 (void)add_edge(ptadr, src);
1880 src->set_arraycopy_src();
1881 // Add edge from destination object to arraycopy node.
1882 (void)add_edge(dst, ptadr);
1883 dst->set_arraycopy_dst();
1884 }
1885
1886 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1887 const Type* adr_type = n->as_AddP()->bottom_type();
1888 BasicType bt = T_INT;
1889 if (offset == Type::OffsetBot) {
1890 // Check only oop fields.
1891 if (!adr_type->isa_aryptr() ||
1892 (adr_type->isa_aryptr()->klass() == NULL) ||
1893 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1894 // OffsetBot is used to reference array's element. Ignore first AddP.
1895 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1896 bt = T_OBJECT;
1897 }
1898 }
1899 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1900 if (adr_type->isa_instptr()) {
1901 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1902 if (field != NULL) {
1903 bt = field->layout_type();
1904 } else {
1905 // Check for unsafe oop field access
1906 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1907 int opcode = n->fast_out(i)->Opcode();
1908 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1909 opcode == Op_StoreN || opcode == Op_LoadN) {
1910 bt = T_OBJECT;
1911 (*unsafe) = true;
1912 break;
1913 }
1914 }
1915 }
1916 } else if (adr_type->isa_aryptr()) {
1917 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1918 // Ignore array length load.
1919 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1920 // Ignore first AddP.
1921 } else {
1922 const Type* elemtype = adr_type->isa_aryptr()->elem();
1923 bt = elemtype->array_element_basic_type();
1924 }
1925 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1926 // Allocation initialization, ThreadLocal field access, unsafe access
1927 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1928 int opcode = n->fast_out(i)->Opcode();
1929 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1930 opcode == Op_StoreN || opcode == Op_LoadN) {
1931 bt = T_OBJECT;
1932 break;
1933 }
1934 }
1935 }
1936 }
1937 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1938 }
1939
1940 // Returns unique pointed java object or NULL.
1941 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1942 assert(!_collecting, "should not call when contructed graph");
1943 // If the node was created after the escape computation we can't answer.
1944 uint idx = n->_idx;
1945 if (idx >= nodes_size()) {
1946 return NULL;
1947 }
1948 PointsToNode* ptn = ptnode_adr(idx);
1949 if (ptn->is_JavaObject()) {
1950 return ptn->as_JavaObject();
1951 }
1952 assert(ptn->is_LocalVar(), "sanity");
1953 // Check all java objects it points to.
1954 JavaObjectNode* jobj = NULL;
1955 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1956 PointsToNode* e = i.get();
1957 if (e->is_JavaObject()) {
1958 if (jobj == NULL) {
1959 jobj = e->as_JavaObject();
1960 } else if (jobj != e) {
1961 return NULL;
1962 }
1963 }
1964 }
1965 return jobj;
1966 }
1967
1968 // Return true if this node points only to non-escaping allocations.
1969 bool PointsToNode::non_escaping_allocation() {
1970 if (is_JavaObject()) {
1971 Node* n = ideal_node();
1972 if (n->is_Allocate() || n->is_CallStaticJava()) {
1973 return (escape_state() == PointsToNode::NoEscape);
1974 } else {
1975 return false;
1976 }
1977 }
1978 assert(is_LocalVar(), "sanity");
1979 // Check all java objects it points to.
1980 for (EdgeIterator i(this); i.has_next(); i.next()) {
1981 PointsToNode* e = i.get();
1982 if (e->is_JavaObject()) {
1983 Node* n = e->ideal_node();
1984 if ((e->escape_state() != PointsToNode::NoEscape) ||
1985 !(n->is_Allocate() || n->is_CallStaticJava())) {
1986 return false;
1987 }
1988 }
1989 }
1990 return true;
1991 }
1992
1993 // Return true if we know the node does not escape globally.
1994 bool ConnectionGraph::not_global_escape(Node *n) {
1995 assert(!_collecting, "should not call during graph construction");
1996 // If the node was created after the escape computation we can't answer.
1997 uint idx = n->_idx;
1998 if (idx >= nodes_size()) {
1999 return false;
2000 }
2001 PointsToNode* ptn = ptnode_adr(idx);
2002 PointsToNode::EscapeState es = ptn->escape_state();
2003 // If we have already computed a value, return it.
2004 if (es >= PointsToNode::GlobalEscape)
2005 return false;
2006 if (ptn->is_JavaObject()) {
2007 return true; // (es < PointsToNode::GlobalEscape);
2008 }
2009 assert(ptn->is_LocalVar(), "sanity");
2010 // Check all java objects it points to.
2011 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2012 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2013 return false;
2014 }
2015 return true;
2016 }
2017
2018
2019 // Helper functions
2020
2021 // Return true if this node points to specified node or nodes it points to.
2022 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2023 if (is_JavaObject()) {
2024 return (this == ptn);
2025 }
2026 assert(is_LocalVar() || is_Field(), "sanity");
2027 for (EdgeIterator i(this); i.has_next(); i.next()) {
2028 if (i.get() == ptn)
2029 return true;
2030 }
2031 return false;
2032 }
2033
2034 // Return true if one node points to an other.
2035 bool PointsToNode::meet(PointsToNode* ptn) {
2036 if (this == ptn) {
2037 return true;
2038 } else if (ptn->is_JavaObject()) {
2039 return this->points_to(ptn->as_JavaObject());
2040 } else if (this->is_JavaObject()) {
2041 return ptn->points_to(this->as_JavaObject());
2042 }
2043 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2044 int ptn_count = ptn->edge_count();
2045 for (EdgeIterator i(this); i.has_next(); i.next()) {
2046 PointsToNode* this_e = i.get();
2047 for (int j = 0; j < ptn_count; j++) {
2048 if (this_e == ptn->edge(j))
2049 return true;
2050 }
2051 }
2052 return false;
2053 }
2054
2055 #ifdef ASSERT
2056 // Return true if bases point to this java object.
2057 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2058 for (BaseIterator i(this); i.has_next(); i.next()) {
2059 if (i.get() == jobj)
2060 return true;
2061 }
2062 return false;
2063 }
2064 #endif
2065
2066 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2067 const Type *adr_type = phase->type(adr);
2068 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2069 adr->in(AddPNode::Address)->is_Proj() &&
2070 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2071 // We are computing a raw address for a store captured by an Initialize
2072 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2073 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2074 assert(offs != Type::OffsetBot ||
2075 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2076 "offset must be a constant or it is initialization of array");
2077 return offs;
2078 }
2079 const TypePtr *t_ptr = adr_type->isa_ptr();
2080 assert(t_ptr != NULL, "must be a pointer type");
2081 return t_ptr->offset();
2082 }
2083
2084 Node* ConnectionGraph::get_addp_base(Node *addp) {
2085 assert(addp->is_AddP(), "must be AddP");
2086 //
2087 // AddP cases for Base and Address inputs:
2088 // case #1. Direct object's field reference:
2089 // Allocate
2090 // |
2091 // Proj #5 ( oop result )
2092 // |
2093 // CheckCastPP (cast to instance type)
2094 // | |
2095 // AddP ( base == address )
2096 //
2097 // case #2. Indirect object's field reference:
2098 // Phi
2099 // |
2100 // CastPP (cast to instance type)
2101 // | |
2102 // AddP ( base == address )
2103 //
2104 // case #3. Raw object's field reference for Initialize node:
2105 // Allocate
2106 // |
2107 // Proj #5 ( oop result )
2108 // top |
2109 // \ |
2110 // AddP ( base == top )
2111 //
2112 // case #4. Array's element reference:
2113 // {CheckCastPP | CastPP}
2114 // | | |
2115 // | AddP ( array's element offset )
2116 // | |
2117 // AddP ( array's offset )
2118 //
2119 // case #5. Raw object's field reference for arraycopy stub call:
2120 // The inline_native_clone() case when the arraycopy stub is called
2121 // after the allocation before Initialize and CheckCastPP nodes.
2122 // Allocate
2123 // |
2124 // Proj #5 ( oop result )
2125 // | |
2126 // AddP ( base == address )
2127 //
2128 // case #6. Constant Pool, ThreadLocal, CastX2P or
2129 // Raw object's field reference:
2130 // {ConP, ThreadLocal, CastX2P, raw Load}
2131 // top |
2132 // \ |
2133 // AddP ( base == top )
2134 //
2135 // case #7. Klass's field reference.
2136 // LoadKlass
2137 // | |
2138 // AddP ( base == address )
2139 //
2140 // case #8. narrow Klass's field reference.
2141 // LoadNKlass
2142 // |
2143 // DecodeN
2144 // | |
2145 // AddP ( base == address )
2146 //
2147 Node *base = addp->in(AddPNode::Base);
2148 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2149 base = addp->in(AddPNode::Address);
2150 while (base->is_AddP()) {
2151 // Case #6 (unsafe access) may have several chained AddP nodes.
2152 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2153 base = base->in(AddPNode::Address);
2154 }
2155 Node* uncast_base = base->uncast();
2156 int opcode = uncast_base->Opcode();
2157 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2158 opcode == Op_CastX2P || uncast_base->is_DecodeN() ||
2159 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
2160 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2161 }
2162 return base;
2163 }
2164
2165 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2166 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2167 Node* addp2 = addp->raw_out(0);
2168 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2169 addp2->in(AddPNode::Base) == n &&
2170 addp2->in(AddPNode::Address) == addp) {
2171 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2172 //
2173 // Find array's offset to push it on worklist first and
2174 // as result process an array's element offset first (pushed second)
2175 // to avoid CastPP for the array's offset.
2176 // Otherwise the inserted CastPP (LocalVar) will point to what
2177 // the AddP (Field) points to. Which would be wrong since
2178 // the algorithm expects the CastPP has the same point as
2179 // as AddP's base CheckCastPP (LocalVar).
2180 //
2181 // ArrayAllocation
2182 // |
2183 // CheckCastPP
2184 // |
2185 // memProj (from ArrayAllocation CheckCastPP)
2186 // | ||
2187 // | || Int (element index)
2188 // | || | ConI (log(element size))
2189 // | || | /
2190 // | || LShift
2191 // | || /
2192 // | AddP (array's element offset)
2193 // | |
2194 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2195 // | / /
2196 // AddP (array's offset)
2197 // |
2198 // Load/Store (memory operation on array's element)
2199 //
2200 return addp2;
2201 }
2202 return NULL;
2203 }
2204
2205 //
2206 // Adjust the type and inputs of an AddP which computes the
2207 // address of a field of an instance
2208 //
2209 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2210 PhaseGVN* igvn = _igvn;
2211 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2212 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2213 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2214 if (t == NULL) {
2215 // We are computing a raw address for a store captured by an Initialize
2216 // compute an appropriate address type (cases #3 and #5).
2217 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2218 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2219 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2220 assert(offs != Type::OffsetBot, "offset must be a constant");
2221 t = base_t->add_offset(offs)->is_oopptr();
2222 }
2223 int inst_id = base_t->instance_id();
2224 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2225 "old type must be non-instance or match new type");
2226
2227 // The type 't' could be subclass of 'base_t'.
2228 // As result t->offset() could be large then base_t's size and it will
2229 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2230 // constructor verifies correctness of the offset.
2231 //
2232 // It could happened on subclass's branch (from the type profiling
2233 // inlining) which was not eliminated during parsing since the exactness
2234 // of the allocation type was not propagated to the subclass type check.
2235 //
2236 // Or the type 't' could be not related to 'base_t' at all.
2237 // It could happened when CHA type is different from MDO type on a dead path
2238 // (for example, from instanceof check) which is not collapsed during parsing.
2239 //
2240 // Do nothing for such AddP node and don't process its users since
2241 // this code branch will go away.
2242 //
2243 if (!t->is_known_instance() &&
2244 !base_t->klass()->is_subtype_of(t->klass())) {
2245 return false; // bail out
2246 }
2247 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2248 // Do NOT remove the next line: ensure a new alias index is allocated
2249 // for the instance type. Note: C++ will not remove it since the call
2250 // has side effect.
2251 int alias_idx = _compile->get_alias_index(tinst);
2252 igvn->set_type(addp, tinst);
2253 // record the allocation in the node map
2254 set_map(addp, get_map(base->_idx));
2255 // Set addp's Base and Address to 'base'.
2256 Node *abase = addp->in(AddPNode::Base);
2257 Node *adr = addp->in(AddPNode::Address);
2258 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2259 adr->in(0)->_idx == (uint)inst_id) {
2260 // Skip AddP cases #3 and #5.
2261 } else {
2262 assert(!abase->is_top(), "sanity"); // AddP case #3
2263 if (abase != base) {
2264 igvn->hash_delete(addp);
2265 addp->set_req(AddPNode::Base, base);
2266 if (abase == adr) {
2267 addp->set_req(AddPNode::Address, base);
2268 } else {
2269 // AddP case #4 (adr is array's element offset AddP node)
2270 #ifdef ASSERT
2271 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2272 assert(adr->is_AddP() && atype != NULL &&
2273 atype->instance_id() == inst_id, "array's element offset should be processed first");
2274 #endif
2275 }
2276 igvn->hash_insert(addp);
2277 }
2278 }
2279 // Put on IGVN worklist since at least addp's type was changed above.
2280 record_for_optimizer(addp);
2281 return true;
2282 }
2283
2284 //
2285 // Create a new version of orig_phi if necessary. Returns either the newly
2286 // created phi or an existing phi. Sets create_new to indicate whether a new
2287 // phi was created. Cache the last newly created phi in the node map.
2288 //
2289 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2290 Compile *C = _compile;
2291 PhaseGVN* igvn = _igvn;
2292 new_created = false;
2293 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2294 // nothing to do if orig_phi is bottom memory or matches alias_idx
2295 if (phi_alias_idx == alias_idx) {
2296 return orig_phi;
2297 }
2298 // Have we recently created a Phi for this alias index?
2299 PhiNode *result = get_map_phi(orig_phi->_idx);
2300 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2301 return result;
2302 }
2303 // Previous check may fail when the same wide memory Phi was split into Phis
2304 // for different memory slices. Search all Phis for this region.
2305 if (result != NULL) {
2306 Node* region = orig_phi->in(0);
2307 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2308 Node* phi = region->fast_out(i);
2309 if (phi->is_Phi() &&
2310 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2311 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2312 return phi->as_Phi();
2313 }
2314 }
2315 }
2316 if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2317 if (C->do_escape_analysis() == true && !C->failing()) {
2318 // Retry compilation without escape analysis.
2319 // If this is the first failure, the sentinel string will "stick"
2320 // to the Compile object, and the C2Compiler will see it and retry.
2321 C->record_failure(C2Compiler::retry_no_escape_analysis());
2322 }
2323 return NULL;
2324 }
2325 orig_phi_worklist.append_if_missing(orig_phi);
2326 const TypePtr *atype = C->get_adr_type(alias_idx);
2327 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2328 C->copy_node_notes_to(result, orig_phi);
2329 igvn->set_type(result, result->bottom_type());
2330 record_for_optimizer(result);
2331 set_map(orig_phi, result);
2332 new_created = true;
2333 return result;
2334 }
2335
2336 //
2337 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2338 // specified alias index.
2339 //
2340 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2341 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2342 Compile *C = _compile;
2343 PhaseGVN* igvn = _igvn;
2344 bool new_phi_created;
2345 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2346 if (!new_phi_created) {
2347 return result;
2348 }
2349 GrowableArray<PhiNode *> phi_list;
2350 GrowableArray<uint> cur_input;
2351 PhiNode *phi = orig_phi;
2352 uint idx = 1;
2353 bool finished = false;
2354 while(!finished) {
2355 while (idx < phi->req()) {
2356 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2357 if (mem != NULL && mem->is_Phi()) {
2358 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2359 if (new_phi_created) {
2360 // found an phi for which we created a new split, push current one on worklist and begin
2361 // processing new one
2362 phi_list.push(phi);
2363 cur_input.push(idx);
2364 phi = mem->as_Phi();
2365 result = newphi;
2366 idx = 1;
2367 continue;
2368 } else {
2369 mem = newphi;
2370 }
2371 }
2372 if (C->failing()) {
2373 return NULL;
2374 }
2375 result->set_req(idx++, mem);
2376 }
2377 #ifdef ASSERT
2378 // verify that the new Phi has an input for each input of the original
2379 assert( phi->req() == result->req(), "must have same number of inputs.");
2380 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2381 #endif
2382 // Check if all new phi's inputs have specified alias index.
2383 // Otherwise use old phi.
2384 for (uint i = 1; i < phi->req(); i++) {
2385 Node* in = result->in(i);
2386 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2387 }
2388 // we have finished processing a Phi, see if there are any more to do
2389 finished = (phi_list.length() == 0 );
2390 if (!finished) {
2391 phi = phi_list.pop();
2392 idx = cur_input.pop();
2393 PhiNode *prev_result = get_map_phi(phi->_idx);
2394 prev_result->set_req(idx++, result);
2395 result = prev_result;
2396 }
2397 }
2398 return result;
2399 }
2400
2401 //
2402 // The next methods are derived from methods in MemNode.
2403 //
2404 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2405 Node *mem = mmem;
2406 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2407 // means an array I have not precisely typed yet. Do not do any
2408 // alias stuff with it any time soon.
2409 if (toop->base() != Type::AnyPtr &&
2410 !(toop->klass() != NULL &&
2411 toop->klass()->is_java_lang_Object() &&
2412 toop->offset() == Type::OffsetBot)) {
2413 mem = mmem->memory_at(alias_idx);
2414 // Update input if it is progress over what we have now
2415 }
2416 return mem;
2417 }
2418
2419 //
2420 // Move memory users to their memory slices.
2421 //
2422 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2423 Compile* C = _compile;
2424 PhaseGVN* igvn = _igvn;
2425 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2426 assert(tp != NULL, "ptr type");
2427 int alias_idx = C->get_alias_index(tp);
2428 int general_idx = C->get_general_index(alias_idx);
2429
2430 // Move users first
2431 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2432 Node* use = n->fast_out(i);
2433 if (use->is_MergeMem()) {
2434 MergeMemNode* mmem = use->as_MergeMem();
2435 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2436 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2437 continue; // Nothing to do
2438 }
2439 // Replace previous general reference to mem node.
2440 uint orig_uniq = C->unique();
2441 Node* m = find_inst_mem(n, general_idx, orig_phis);
2442 assert(orig_uniq == C->unique(), "no new nodes");
2443 mmem->set_memory_at(general_idx, m);
2444 --imax;
2445 --i;
2446 } else if (use->is_MemBar()) {
2447 assert(!use->is_Initialize(), "initializing stores should not be moved");
2448 if (use->req() > MemBarNode::Precedent &&
2449 use->in(MemBarNode::Precedent) == n) {
2450 // Don't move related membars.
2451 record_for_optimizer(use);
2452 continue;
2453 }
2454 tp = use->as_MemBar()->adr_type()->isa_ptr();
2455 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2456 alias_idx == general_idx) {
2457 continue; // Nothing to do
2458 }
2459 // Move to general memory slice.
2460 uint orig_uniq = C->unique();
2461 Node* m = find_inst_mem(n, general_idx, orig_phis);
2462 assert(orig_uniq == C->unique(), "no new nodes");
2463 igvn->hash_delete(use);
2464 imax -= use->replace_edge(n, m);
2465 igvn->hash_insert(use);
2466 record_for_optimizer(use);
2467 --i;
2468 #ifdef ASSERT
2469 } else if (use->is_Mem()) {
2470 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2471 // Don't move related cardmark.
2472 continue;
2473 }
2474 // Memory nodes should have new memory input.
2475 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2476 assert(tp != NULL, "ptr type");
2477 int idx = C->get_alias_index(tp);
2478 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2479 "Following memory nodes should have new memory input or be on the same memory slice");
2480 } else if (use->is_Phi()) {
2481 // Phi nodes should be split and moved already.
2482 tp = use->as_Phi()->adr_type()->isa_ptr();
2483 assert(tp != NULL, "ptr type");
2484 int idx = C->get_alias_index(tp);
2485 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2486 } else {
2487 use->dump();
2488 assert(false, "should not be here");
2489 #endif
2490 }
2491 }
2492 }
2493
2494 //
2495 // Search memory chain of "mem" to find a MemNode whose address
2496 // is the specified alias index.
2497 //
2498 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2499 if (orig_mem == NULL)
2500 return orig_mem;
2501 Compile* C = _compile;
2502 PhaseGVN* igvn = _igvn;
2503 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2504 bool is_instance = (toop != NULL) && toop->is_known_instance();
2505 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2506 Node *prev = NULL;
2507 Node *result = orig_mem;
2508 while (prev != result) {
2509 prev = result;
2510 if (result == start_mem)
2511 break; // hit one of our sentinels
2512 if (result->is_Mem()) {
2513 const Type *at = igvn->type(result->in(MemNode::Address));
2514 if (at == Type::TOP)
2515 break; // Dead
2516 assert (at->isa_ptr() != NULL, "pointer type required.");
2517 int idx = C->get_alias_index(at->is_ptr());
2518 if (idx == alias_idx)
2519 break; // Found
2520 if (!is_instance && (at->isa_oopptr() == NULL ||
2521 !at->is_oopptr()->is_known_instance())) {
2522 break; // Do not skip store to general memory slice.
2523 }
2524 result = result->in(MemNode::Memory);
2525 }
2526 if (!is_instance)
2527 continue; // don't search further for non-instance types
2528 // skip over a call which does not affect this memory slice
2529 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2530 Node *proj_in = result->in(0);
2531 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2532 break; // hit one of our sentinels
2533 } else if (proj_in->is_Call()) {
2534 CallNode *call = proj_in->as_Call();
2535 if (!call->may_modify(toop, igvn)) {
2536 result = call->in(TypeFunc::Memory);
2537 }
2538 } else if (proj_in->is_Initialize()) {
2539 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2540 // Stop if this is the initialization for the object instance which
2541 // which contains this memory slice, otherwise skip over it.
2542 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2543 result = proj_in->in(TypeFunc::Memory);
2544 }
2545 } else if (proj_in->is_MemBar()) {
2546 result = proj_in->in(TypeFunc::Memory);
2547 }
2548 } else if (result->is_MergeMem()) {
2549 MergeMemNode *mmem = result->as_MergeMem();
2550 result = step_through_mergemem(mmem, alias_idx, toop);
2551 if (result == mmem->base_memory()) {
2552 // Didn't find instance memory, search through general slice recursively.
2553 result = mmem->memory_at(C->get_general_index(alias_idx));
2554 result = find_inst_mem(result, alias_idx, orig_phis);
2555 if (C->failing()) {
2556 return NULL;
2557 }
2558 mmem->set_memory_at(alias_idx, result);
2559 }
2560 } else if (result->is_Phi() &&
2561 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2562 Node *un = result->as_Phi()->unique_input(igvn);
2563 if (un != NULL) {
2564 orig_phis.append_if_missing(result->as_Phi());
2565 result = un;
2566 } else {
2567 break;
2568 }
2569 } else if (result->is_ClearArray()) {
2570 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2571 // Can not bypass initialization of the instance
2572 // we are looking for.
2573 break;
2574 }
2575 // Otherwise skip it (the call updated 'result' value).
2576 } else if (result->Opcode() == Op_SCMemProj) {
2577 assert(result->in(0)->is_LoadStore(), "sanity");
2578 const Type *at = igvn->type(result->in(0)->in(MemNode::Address));
2579 if (at != Type::TOP) {
2580 assert (at->isa_ptr() != NULL, "pointer type required.");
2581 int idx = C->get_alias_index(at->is_ptr());
2582 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2583 break;
2584 }
2585 result = result->in(0)->in(MemNode::Memory);
2586 }
2587 }
2588 if (result->is_Phi()) {
2589 PhiNode *mphi = result->as_Phi();
2590 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2591 const TypePtr *t = mphi->adr_type();
2592 if (!is_instance) {
2593 // Push all non-instance Phis on the orig_phis worklist to update inputs
2594 // during Phase 4 if needed.
2595 orig_phis.append_if_missing(mphi);
2596 } else if (C->get_alias_index(t) != alias_idx) {
2597 // Create a new Phi with the specified alias index type.
2598 result = split_memory_phi(mphi, alias_idx, orig_phis);
2599 }
2600 }
2601 // the result is either MemNode, PhiNode, InitializeNode.
2602 return result;
2603 }
2604
2605 //
2606 // Convert the types of unescaped object to instance types where possible,
2607 // propagate the new type information through the graph, and update memory
2608 // edges and MergeMem inputs to reflect the new type.
2609 //
2610 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2611 // The processing is done in 4 phases:
2612 //
2613 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2614 // types for the CheckCastPP for allocations where possible.
2615 // Propagate the the new types through users as follows:
2616 // casts and Phi: push users on alloc_worklist
2617 // AddP: cast Base and Address inputs to the instance type
2618 // push any AddP users on alloc_worklist and push any memnode
2619 // users onto memnode_worklist.
2620 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2621 // search the Memory chain for a store with the appropriate type
2622 // address type. If a Phi is found, create a new version with
2623 // the appropriate memory slices from each of the Phi inputs.
2624 // For stores, process the users as follows:
2625 // MemNode: push on memnode_worklist
2626 // MergeMem: push on mergemem_worklist
2627 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2628 // moving the first node encountered of each instance type to the
2629 // the input corresponding to its alias index.
2630 // appropriate memory slice.
2631 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2632 //
2633 // In the following example, the CheckCastPP nodes are the cast of allocation
2634 // results and the allocation of node 29 is unescaped and eligible to be an
2635 // instance type.
2636 //
2637 // We start with:
2638 //
2639 // 7 Parm #memory
2640 // 10 ConI "12"
2641 // 19 CheckCastPP "Foo"
2642 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2643 // 29 CheckCastPP "Foo"
2644 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2645 //
2646 // 40 StoreP 25 7 20 ... alias_index=4
2647 // 50 StoreP 35 40 30 ... alias_index=4
2648 // 60 StoreP 45 50 20 ... alias_index=4
2649 // 70 LoadP _ 60 30 ... alias_index=4
2650 // 80 Phi 75 50 60 Memory alias_index=4
2651 // 90 LoadP _ 80 30 ... alias_index=4
2652 // 100 LoadP _ 80 20 ... alias_index=4
2653 //
2654 //
2655 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2656 // and creating a new alias index for node 30. This gives:
2657 //
2658 // 7 Parm #memory
2659 // 10 ConI "12"
2660 // 19 CheckCastPP "Foo"
2661 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2662 // 29 CheckCastPP "Foo" iid=24
2663 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2664 //
2665 // 40 StoreP 25 7 20 ... alias_index=4
2666 // 50 StoreP 35 40 30 ... alias_index=6
2667 // 60 StoreP 45 50 20 ... alias_index=4
2668 // 70 LoadP _ 60 30 ... alias_index=6
2669 // 80 Phi 75 50 60 Memory alias_index=4
2670 // 90 LoadP _ 80 30 ... alias_index=6
2671 // 100 LoadP _ 80 20 ... alias_index=4
2672 //
2673 // In phase 2, new memory inputs are computed for the loads and stores,
2674 // And a new version of the phi is created. In phase 4, the inputs to
2675 // node 80 are updated and then the memory nodes are updated with the
2676 // values computed in phase 2. This results in:
2677 //
2678 // 7 Parm #memory
2679 // 10 ConI "12"
2680 // 19 CheckCastPP "Foo"
2681 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2682 // 29 CheckCastPP "Foo" iid=24
2683 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2684 //
2685 // 40 StoreP 25 7 20 ... alias_index=4
2686 // 50 StoreP 35 7 30 ... alias_index=6
2687 // 60 StoreP 45 40 20 ... alias_index=4
2688 // 70 LoadP _ 50 30 ... alias_index=6
2689 // 80 Phi 75 40 60 Memory alias_index=4
2690 // 120 Phi 75 50 50 Memory alias_index=6
2691 // 90 LoadP _ 120 30 ... alias_index=6
2692 // 100 LoadP _ 80 20 ... alias_index=4
2693 //
2694 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2695 GrowableArray<Node *> memnode_worklist;
2696 GrowableArray<PhiNode *> orig_phis;
2697 PhaseIterGVN *igvn = _igvn;
2698 uint new_index_start = (uint) _compile->num_alias_types();
2699 Arena* arena = Thread::current()->resource_area();
2700 VectorSet visited(arena);
2701 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2702 uint unique_old = _compile->unique();
2703
2704 // Phase 1: Process possible allocations from alloc_worklist.
2705 // Create instance types for the CheckCastPP for allocations where possible.
2706 //
2707 // (Note: don't forget to change the order of the second AddP node on
2708 // the alloc_worklist if the order of the worklist processing is changed,
2709 // see the comment in find_second_addp().)
2710 //
2711 while (alloc_worklist.length() != 0) {
2712 Node *n = alloc_worklist.pop();
2713 uint ni = n->_idx;
2714 if (n->is_Call()) {
2715 CallNode *alloc = n->as_Call();
2716 // copy escape information to call node
2717 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2718 PointsToNode::EscapeState es = ptn->escape_state();
2719 // We have an allocation or call which returns a Java object,
2720 // see if it is unescaped.
2721 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2722 continue;
2723 // Find CheckCastPP for the allocate or for the return value of a call
2724 n = alloc->result_cast();
2725 if (n == NULL) { // No uses except Initialize node
2726 if (alloc->is_Allocate()) {
2727 // Set the scalar_replaceable flag for allocation
2728 // so it could be eliminated if it has no uses.
2729 alloc->as_Allocate()->_is_scalar_replaceable = true;
2730 }
2731 continue;
2732 }
2733 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2734 assert(!alloc->is_Allocate(), "allocation should have unique type");
2735 continue;
2736 }
2737
2738 // The inline code for Object.clone() casts the allocation result to
2739 // java.lang.Object and then to the actual type of the allocated
2740 // object. Detect this case and use the second cast.
2741 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2742 // the allocation result is cast to java.lang.Object and then
2743 // to the actual Array type.
2744 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2745 && (alloc->is_AllocateArray() ||
2746 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2747 Node *cast2 = NULL;
2748 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2749 Node *use = n->fast_out(i);
2750 if (use->is_CheckCastPP()) {
2751 cast2 = use;
2752 break;
2753 }
2754 }
2755 if (cast2 != NULL) {
2756 n = cast2;
2757 } else {
2758 // Non-scalar replaceable if the allocation type is unknown statically
2759 // (reflection allocation), the object can't be restored during
2760 // deoptimization without precise type.
2761 continue;
2762 }
2763 }
2764 if (alloc->is_Allocate()) {
2765 // Set the scalar_replaceable flag for allocation
2766 // so it could be eliminated.
2767 alloc->as_Allocate()->_is_scalar_replaceable = true;
2768 }
2769 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2770 // in order for an object to be scalar-replaceable, it must be:
2771 // - a direct allocation (not a call returning an object)
2772 // - non-escaping
2773 // - eligible to be a unique type
2774 // - not determined to be ineligible by escape analysis
2775 set_map(alloc, n);
2776 set_map(n, alloc);
2777 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2778 if (t == NULL)
2779 continue; // not a TypeOopPtr
2780 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2781 igvn->hash_delete(n);
2782 igvn->set_type(n, tinst);
2783 n->raise_bottom_type(tinst);
2784 igvn->hash_insert(n);
2785 record_for_optimizer(n);
2786 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2787
2788 // First, put on the worklist all Field edges from Connection Graph
2789 // which is more accurate then putting immediate users from Ideal Graph.
2790 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2791 PointsToNode* tgt = e.get();
2792 Node* use = tgt->ideal_node();
2793 assert(tgt->is_Field() && use->is_AddP(),
2794 "only AddP nodes are Field edges in CG");
2795 if (use->outcnt() > 0) { // Don't process dead nodes
2796 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2797 if (addp2 != NULL) {
2798 assert(alloc->is_AllocateArray(),"array allocation was expected");
2799 alloc_worklist.append_if_missing(addp2);
2800 }
2801 alloc_worklist.append_if_missing(use);
2802 }
2803 }
2804
2805 // An allocation may have an Initialize which has raw stores. Scan
2806 // the users of the raw allocation result and push AddP users
2807 // on alloc_worklist.
2808 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2809 assert (raw_result != NULL, "must have an allocation result");
2810 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2811 Node *use = raw_result->fast_out(i);
2812 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2813 Node* addp2 = find_second_addp(use, raw_result);
2814 if (addp2 != NULL) {
2815 assert(alloc->is_AllocateArray(),"array allocation was expected");
2816 alloc_worklist.append_if_missing(addp2);
2817 }
2818 alloc_worklist.append_if_missing(use);
2819 } else if (use->is_MemBar()) {
2820 memnode_worklist.append_if_missing(use);
2821 }
2822 }
2823 }
2824 } else if (n->is_AddP()) {
2825 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2826 if (jobj == NULL || jobj == phantom_obj) {
2827 #ifdef ASSERT
2828 ptnode_adr(get_addp_base(n)->_idx)->dump();
2829 ptnode_adr(n->_idx)->dump();
2830 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2831 #endif
2832 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2833 return;
2834 }
2835 Node *base = get_map(jobj->idx()); // CheckCastPP node
2836 if (!split_AddP(n, base)) continue; // wrong type from dead path
2837 } else if (n->is_Phi() ||
2838 n->is_CheckCastPP() ||
2839 n->is_EncodeP() ||
2840 n->is_DecodeN() ||
2841 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2842 if (visited.test_set(n->_idx)) {
2843 assert(n->is_Phi(), "loops only through Phi's");
2844 continue; // already processed
2845 }
2846 JavaObjectNode* jobj = unique_java_object(n);
2847 if (jobj == NULL || jobj == phantom_obj) {
2848 #ifdef ASSERT
2849 ptnode_adr(n->_idx)->dump();
2850 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2851 #endif
2852 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2853 return;
2854 } else {
2855 Node *val = get_map(jobj->idx()); // CheckCastPP node
2856 TypeNode *tn = n->as_Type();
2857 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2858 assert(tinst != NULL && tinst->is_known_instance() &&
2859 tinst->instance_id() == jobj->idx() , "instance type expected.");
2860
2861 const Type *tn_type = igvn->type(tn);
2862 const TypeOopPtr *tn_t;
2863 if (tn_type->isa_narrowoop()) {
2864 tn_t = tn_type->make_ptr()->isa_oopptr();
2865 } else {
2866 tn_t = tn_type->isa_oopptr();
2867 }
2868 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2869 if (tn_type->isa_narrowoop()) {
2870 tn_type = tinst->make_narrowoop();
2871 } else {
2872 tn_type = tinst;
2873 }
2874 igvn->hash_delete(tn);
2875 igvn->set_type(tn, tn_type);
2876 tn->set_type(tn_type);
2877 igvn->hash_insert(tn);
2878 record_for_optimizer(n);
2879 } else {
2880 assert(tn_type == TypePtr::NULL_PTR ||
2881 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2882 "unexpected type");
2883 continue; // Skip dead path with different type
2884 }
2885 }
2886 } else {
2887 debug_only(n->dump();)
2888 assert(false, "EA: unexpected node");
2889 continue;
2890 }
2891 // push allocation's users on appropriate worklist
2892 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2893 Node *use = n->fast_out(i);
2894 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2895 // Load/store to instance's field
2896 memnode_worklist.append_if_missing(use);
2897 } else if (use->is_MemBar()) {
2898 memnode_worklist.append_if_missing(use);
2899 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2900 Node* addp2 = find_second_addp(use, n);
2901 if (addp2 != NULL) {
2902 alloc_worklist.append_if_missing(addp2);
2903 }
2904 alloc_worklist.append_if_missing(use);
2905 } else if (use->is_Phi() ||
2906 use->is_CheckCastPP() ||
2907 use->is_EncodeP() ||
2908 use->is_DecodeN() ||
2909 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2910 alloc_worklist.append_if_missing(use);
2911 #ifdef ASSERT
2912 } else if (use->is_Mem()) {
2913 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2914 } else if (use->is_MergeMem()) {
2915 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2916 } else if (use->is_SafePoint()) {
2917 // Look for MergeMem nodes for calls which reference unique allocation
2918 // (through CheckCastPP nodes) even for debug info.
2919 Node* m = use->in(TypeFunc::Memory);
2920 if (m->is_MergeMem()) {
2921 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2922 }
2923 } else {
2924 uint op = use->Opcode();
2925 if (!(op == Op_CmpP || op == Op_Conv2B ||
2926 op == Op_CastP2X || op == Op_StoreCM ||
2927 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
2928 op == Op_StrEquals || op == Op_StrIndexOf)) {
2929 n->dump();
2930 use->dump();
2931 assert(false, "EA: missing allocation reference path");
2932 }
2933 #endif
2934 }
2935 }
2936
2937 }
2938 // New alias types were created in split_AddP().
2939 uint new_index_end = (uint) _compile->num_alias_types();
2940 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
2941
2942 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2943 // compute new values for Memory inputs (the Memory inputs are not
2944 // actually updated until phase 4.)
2945 if (memnode_worklist.length() == 0)
2946 return; // nothing to do
2947 while (memnode_worklist.length() != 0) {
2948 Node *n = memnode_worklist.pop();
2949 if (visited.test_set(n->_idx))
2950 continue;
2951 if (n->is_Phi() || n->is_ClearArray()) {
2952 // we don't need to do anything, but the users must be pushed
2953 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
2954 // we don't need to do anything, but the users must be pushed
2955 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
2956 if (n == NULL)
2957 continue;
2958 } else {
2959 assert(n->is_Mem(), "memory node required.");
2960 Node *addr = n->in(MemNode::Address);
2961 const Type *addr_t = igvn->type(addr);
2962 if (addr_t == Type::TOP)
2963 continue;
2964 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
2965 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
2966 assert ((uint)alias_idx < new_index_end, "wrong alias index");
2967 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
2968 if (_compile->failing()) {
2969 return;
2970 }
2971 if (mem != n->in(MemNode::Memory)) {
2972 // We delay the memory edge update since we need old one in
2973 // MergeMem code below when instances memory slices are separated.
2974 set_map(n, mem);
2975 }
2976 if (n->is_Load()) {
2977 continue; // don't push users
2978 } else if (n->is_LoadStore()) {
2979 // get the memory projection
2980 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2981 Node *use = n->fast_out(i);
2982 if (use->Opcode() == Op_SCMemProj) {
2983 n = use;
2984 break;
2985 }
2986 }
2987 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
2988 }
2989 }
2990 // push user on appropriate worklist
2991 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2992 Node *use = n->fast_out(i);
2993 if (use->is_Phi() || use->is_ClearArray()) {
2994 memnode_worklist.append_if_missing(use);
2995 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
2996 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
2997 continue;
2998 memnode_worklist.append_if_missing(use);
2999 } else if (use->is_MemBar()) {
3000 memnode_worklist.append_if_missing(use);
3001 #ifdef ASSERT
3002 } else if(use->is_Mem()) {
3003 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3004 } else if (use->is_MergeMem()) {
3005 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3006 } else {
3007 uint op = use->Opcode();
3008 if (!(op == Op_StoreCM ||
3009 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3010 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3011 op == Op_AryEq || op == Op_StrComp ||
3012 op == Op_StrEquals || op == Op_StrIndexOf)) {
3013 n->dump();
3014 use->dump();
3015 assert(false, "EA: missing memory path");
3016 }
3017 #endif
3018 }
3019 }
3020 }
3021
3022 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3023 // Walk each memory slice moving the first node encountered of each
3024 // instance type to the the input corresponding to its alias index.
3025 uint length = _mergemem_worklist.length();
3026 for( uint next = 0; next < length; ++next ) {
3027 MergeMemNode* nmm = _mergemem_worklist.at(next);
3028 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3029 // Note: we don't want to use MergeMemStream here because we only want to
3030 // scan inputs which exist at the start, not ones we add during processing.
3031 // Note 2: MergeMem may already contains instance memory slices added
3032 // during find_inst_mem() call when memory nodes were processed above.
3033 igvn->hash_delete(nmm);
3034 uint nslices = nmm->req();
3035 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3036 Node* mem = nmm->in(i);
3037 Node* cur = NULL;
3038 if (mem == NULL || mem->is_top())
3039 continue;
3040 // First, update mergemem by moving memory nodes to corresponding slices
3041 // if their type became more precise since this mergemem was created.
3042 while (mem->is_Mem()) {
3043 const Type *at = igvn->type(mem->in(MemNode::Address));
3044 if (at != Type::TOP) {
3045 assert (at->isa_ptr() != NULL, "pointer type required.");
3046 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3047 if (idx == i) {
3048 if (cur == NULL)
3049 cur = mem;
3050 } else {
3051 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3052 nmm->set_memory_at(idx, mem);
3053 }
3054 }
3055 }
3056 mem = mem->in(MemNode::Memory);
3057 }
3058 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3059 // Find any instance of the current type if we haven't encountered
3060 // already a memory slice of the instance along the memory chain.
3061 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3062 if((uint)_compile->get_general_index(ni) == i) {
3063 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3064 if (nmm->is_empty_memory(m)) {
3065 Node* result = find_inst_mem(mem, ni, orig_phis);
3066 if (_compile->failing()) {
3067 return;
3068 }
3069 nmm->set_memory_at(ni, result);
3070 }
3071 }
3072 }
3073 }
3074 // Find the rest of instances values
3075 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3076 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3077 Node* result = step_through_mergemem(nmm, ni, tinst);
3078 if (result == nmm->base_memory()) {
3079 // Didn't find instance memory, search through general slice recursively.
3080 result = nmm->memory_at(_compile->get_general_index(ni));
3081 result = find_inst_mem(result, ni, orig_phis);
3082 if (_compile->failing()) {
3083 return;
3084 }
3085 nmm->set_memory_at(ni, result);
3086 }
3087 }
3088 igvn->hash_insert(nmm);
3089 record_for_optimizer(nmm);
3090 }
3091
3092 // Phase 4: Update the inputs of non-instance memory Phis and
3093 // the Memory input of memnodes
3094 // First update the inputs of any non-instance Phi's from
3095 // which we split out an instance Phi. Note we don't have
3096 // to recursively process Phi's encounted on the input memory
3097 // chains as is done in split_memory_phi() since they will
3098 // also be processed here.
3099 for (int j = 0; j < orig_phis.length(); j++) {
3100 PhiNode *phi = orig_phis.at(j);
3101 int alias_idx = _compile->get_alias_index(phi->adr_type());
3102 igvn->hash_delete(phi);
3103 for (uint i = 1; i < phi->req(); i++) {
3104 Node *mem = phi->in(i);
3105 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3106 if (_compile->failing()) {
3107 return;
3108 }
3109 if (mem != new_mem) {
3110 phi->set_req(i, new_mem);
3111 }
3112 }
3113 igvn->hash_insert(phi);
3114 record_for_optimizer(phi);
3115 }
3116
3117 // Update the memory inputs of MemNodes with the value we computed
3118 // in Phase 2 and move stores memory users to corresponding memory slices.
3119 // Disable memory split verification code until the fix for 6984348.
3120 // Currently it produces false negative results since it does not cover all cases.
3121 #if 0 // ifdef ASSERT
3122 visited.Reset();
3123 Node_Stack old_mems(arena, _compile->unique() >> 2);
3124 #endif
3125 for (uint i = 0; i < ideal_nodes.size(); i++) {
3126 Node* n = ideal_nodes.at(i);
3127 Node* nmem = get_map(n->_idx);
3128 assert(nmem != NULL, "sanity");
3129 if (n->is_Mem()) {
3130 #if 0 // ifdef ASSERT
3131 Node* old_mem = n->in(MemNode::Memory);
3132 if (!visited.test_set(old_mem->_idx)) {
3133 old_mems.push(old_mem, old_mem->outcnt());
3134 }
3135 #endif
3136 assert(n->in(MemNode::Memory) != nmem, "sanity");
3137 if (!n->is_Load()) {
3138 // Move memory users of a store first.
3139 move_inst_mem(n, orig_phis);
3140 }
3141 // Now update memory input
3142 igvn->hash_delete(n);
3143 n->set_req(MemNode::Memory, nmem);
3144 igvn->hash_insert(n);
3145 record_for_optimizer(n);
3146 } else {
3147 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3148 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3149 }
3150 }
3151 #if 0 // ifdef ASSERT
3152 // Verify that memory was split correctly
3153 while (old_mems.is_nonempty()) {
3154 Node* old_mem = old_mems.node();
3155 uint old_cnt = old_mems.index();
3156 old_mems.pop();
3157 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3158 }
3159 #endif
3160 }
3161
3162 #ifndef PRODUCT
3163 static const char *node_type_names[] = {
3164 "UnknownType",
3165 "JavaObject",
3166 "LocalVar",
3167 "Field",
3168 "Arraycopy"
3169 };
3170
3171 static const char *esc_names[] = {
3172 "UnknownEscape",
3173 "NoEscape",
3174 "ArgEscape",
3175 "GlobalEscape"
3176 };
3177
3178 void PointsToNode::dump(bool print_state) const {
3179 NodeType nt = node_type();
3180 tty->print("%s ", node_type_names[(int) nt]);
3181 if (print_state) {
3182 EscapeState es = escape_state();
3183 EscapeState fields_es = fields_escape_state();
3184 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3185 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3186 tty->print("NSR ");
3187 }
3188 if (is_Field()) {
3189 FieldNode* f = (FieldNode*)this;
3190 if (f->is_oop())
3191 tty->print("oop ");
3192 if (f->offset() > 0)
3193 tty->print("+%d ", f->offset());
3194 tty->print("(");
3195 for (BaseIterator i(f); i.has_next(); i.next()) {
3196 PointsToNode* b = i.get();
3197 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3198 }
3199 tty->print(" )");
3200 }
3201 tty->print("[");
3202 for (EdgeIterator i(this); i.has_next(); i.next()) {
3203 PointsToNode* e = i.get();
3204 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3205 }
3206 tty->print(" [");
3207 for (UseIterator i(this); i.has_next(); i.next()) {
3208 PointsToNode* u = i.get();
3209 bool is_base = false;
3210 if (PointsToNode::is_base_use(u)) {
3211 is_base = true;
3212 u = PointsToNode::get_use_node(u)->as_Field();
3213 }
3214 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3215 }
3216 tty->print(" ]] ");
3217 if (_node == NULL)
3218 tty->print_cr("<null>");
3219 else
3220 _node->dump();
3221 }
3222
3223 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3224 bool first = true;
3225 int ptnodes_length = ptnodes_worklist.length();
3226 for (int i = 0; i < ptnodes_length; i++) {
3227 PointsToNode *ptn = ptnodes_worklist.at(i);
3228 if (ptn == NULL || !ptn->is_JavaObject())
3229 continue;
3230 PointsToNode::EscapeState es = ptn->escape_state();
3231 if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3232 if (first) {
3233 tty->cr();
3234 tty->print("======== Connection graph for ");
3235 _compile->method()->print_short_name();
3236 tty->cr();
3237 first = false;
3238 }
3239 ptn->dump();
3240 // Print all locals and fields which reference this allocation
3241 for (UseIterator j(ptn); j.has_next(); j.next()) {
3242 PointsToNode* use = j.get();
3243 if (use->is_LocalVar()) {
3244 use->dump(Verbose);
3245 } else if (Verbose) {
3246 use->dump();
3247 }
3248 }
3249 tty->cr();
3250 }
3251 }
3252 }
3253 #endif