1 /*
2 * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "opto/c2compiler.hpp"
31 #include "opto/arraycopynode.hpp"
32 #include "opto/callnode.hpp"
33 #include "opto/cfgnode.hpp"
34 #include "opto/compile.hpp"
35 #include "opto/escape.hpp"
36 #include "opto/phaseX.hpp"
37 #include "opto/movenode.hpp"
38 #include "opto/rootnode.hpp"
39
40 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
41 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
42 _in_worklist(C->comp_arena()),
43 _next_pidx(0),
44 _collecting(true),
45 _verify(false),
46 _compile(C),
47 _igvn(igvn),
48 _node_map(C->comp_arena()) {
49 // Add unknown java object.
50 add_java_object(C->top(), PointsToNode::GlobalEscape);
51 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
52 // Add ConP(#NULL) and ConN(#NULL) nodes.
53 Node* oop_null = igvn->zerocon(T_OBJECT);
54 assert(oop_null->_idx < nodes_size(), "should be created already");
55 add_java_object(oop_null, PointsToNode::NoEscape);
56 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
57 if (UseCompressedOops) {
58 Node* noop_null = igvn->zerocon(T_NARROWOOP);
59 assert(noop_null->_idx < nodes_size(), "should be created already");
60 map_ideal_node(noop_null, null_obj);
61 }
62 _pcmp_neq = NULL; // Should be initialized
63 _pcmp_eq = NULL;
64 }
65
66 bool ConnectionGraph::has_candidates(Compile *C) {
67 // EA brings benefits only when the code has allocations and/or locks which
68 // are represented by ideal Macro nodes.
69 int cnt = C->macro_count();
70 for (int i = 0; i < cnt; i++) {
71 Node *n = C->macro_node(i);
72 if (n->is_Allocate())
73 return true;
74 if (n->is_Lock()) {
75 Node* obj = n->as_Lock()->obj_node()->uncast();
76 if (!(obj->is_Parm() || obj->is_Con()))
77 return true;
78 }
79 if (n->is_CallStaticJava() &&
80 n->as_CallStaticJava()->is_boxing_method()) {
81 return true;
82 }
83 }
84 return false;
85 }
86
87 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
88 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
89 ResourceMark rm;
90
91 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
92 // to create space for them in ConnectionGraph::_nodes[].
93 Node* oop_null = igvn->zerocon(T_OBJECT);
94 Node* noop_null = igvn->zerocon(T_NARROWOOP);
95 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
96 // Perform escape analysis
97 if (congraph->compute_escape()) {
98 // There are non escaping objects.
99 C->set_congraph(congraph);
100 }
101 // Cleanup.
102 if (oop_null->outcnt() == 0)
103 igvn->hash_delete(oop_null);
104 if (noop_null->outcnt() == 0)
105 igvn->hash_delete(noop_null);
106 }
107
108 bool ConnectionGraph::compute_escape() {
109 Compile* C = _compile;
110 PhaseGVN* igvn = _igvn;
111
112 // Worklists used by EA.
113 Unique_Node_List delayed_worklist;
114 GrowableArray<Node*> alloc_worklist;
115 GrowableArray<Node*> ptr_cmp_worklist;
116 GrowableArray<Node*> storestore_worklist;
117 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
118 GrowableArray<PointsToNode*> ptnodes_worklist;
119 GrowableArray<JavaObjectNode*> java_objects_worklist;
120 GrowableArray<JavaObjectNode*> non_escaped_worklist;
121 GrowableArray<FieldNode*> oop_fields_worklist;
122 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
123
124 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
125
126 // 1. Populate Connection Graph (CG) with PointsTo nodes.
127 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
128 // Initialize worklist
129 if (C->root() != NULL) {
130 ideal_nodes.push(C->root());
131 }
132 // Processed ideal nodes are unique on ideal_nodes list
133 // but several ideal nodes are mapped to the phantom_obj.
134 // To avoid duplicated entries on the following worklists
135 // add the phantom_obj only once to them.
136 ptnodes_worklist.append(phantom_obj);
137 java_objects_worklist.append(phantom_obj);
138 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
139 Node* n = ideal_nodes.at(next);
140 // Create PointsTo nodes and add them to Connection Graph. Called
141 // only once per ideal node since ideal_nodes is Unique_Node list.
142 add_node_to_connection_graph(n, &delayed_worklist);
143 PointsToNode* ptn = ptnode_adr(n->_idx);
144 if (ptn != NULL && ptn != phantom_obj) {
145 ptnodes_worklist.append(ptn);
146 if (ptn->is_JavaObject()) {
147 java_objects_worklist.append(ptn->as_JavaObject());
148 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
149 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
150 // Only allocations and java static calls results are interesting.
151 non_escaped_worklist.append(ptn->as_JavaObject());
152 }
153 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
154 oop_fields_worklist.append(ptn->as_Field());
155 }
156 }
157 if (n->is_MergeMem()) {
158 // Collect all MergeMem nodes to add memory slices for
159 // scalar replaceable objects in split_unique_types().
160 _mergemem_worklist.append(n->as_MergeMem());
161 } else if (OptimizePtrCompare && n->is_Cmp() &&
162 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
163 // Collect compare pointers nodes.
164 ptr_cmp_worklist.append(n);
165 } else if (n->is_MemBarStoreStore()) {
166 // Collect all MemBarStoreStore nodes so that depending on the
167 // escape status of the associated Allocate node some of them
168 // may be eliminated.
169 storestore_worklist.append(n);
170 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
171 (n->req() > MemBarNode::Precedent)) {
172 record_for_optimizer(n);
173 #ifdef ASSERT
174 } else if (n->is_AddP()) {
175 // Collect address nodes for graph verification.
176 addp_worklist.append(n);
177 #endif
178 } else if (n->is_ArrayCopy()) {
179 // Keep a list of ArrayCopy nodes so if one of its input is non
180 // escaping, we can record a unique type
181 arraycopy_worklist.append(n->as_ArrayCopy());
182 }
183 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
184 Node* m = n->fast_out(i); // Get user
185 ideal_nodes.push(m);
186 }
187 }
188 if (non_escaped_worklist.length() == 0) {
189 _collecting = false;
190 return false; // Nothing to do.
191 }
192 // Add final simple edges to graph.
193 while(delayed_worklist.size() > 0) {
194 Node* n = delayed_worklist.pop();
195 add_final_edges(n);
196 }
197 int ptnodes_length = ptnodes_worklist.length();
198
199 #ifdef ASSERT
200 if (VerifyConnectionGraph) {
201 // Verify that no new simple edges could be created and all
202 // local vars has edges.
203 _verify = true;
204 for (int next = 0; next < ptnodes_length; ++next) {
205 PointsToNode* ptn = ptnodes_worklist.at(next);
206 add_final_edges(ptn->ideal_node());
207 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
208 ptn->dump();
209 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
210 }
211 }
212 _verify = false;
213 }
214 #endif
215 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
216 // processing, calls to CI to resolve symbols (types, fields, methods)
217 // referenced in bytecode. During symbol resolution VM may throw
218 // an exception which CI cleans and converts to compilation failure.
219 if (C->failing()) return false;
220
221 // 2. Finish Graph construction by propagating references to all
222 // java objects through graph.
223 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
224 java_objects_worklist, oop_fields_worklist)) {
225 // All objects escaped or hit time or iterations limits.
226 _collecting = false;
227 return false;
228 }
229
230 // 3. Adjust scalar_replaceable state of nonescaping objects and push
231 // scalar replaceable allocations on alloc_worklist for processing
232 // in split_unique_types().
233 int non_escaped_length = non_escaped_worklist.length();
234 for (int next = 0; next < non_escaped_length; next++) {
235 JavaObjectNode* ptn = non_escaped_worklist.at(next);
236 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
237 Node* n = ptn->ideal_node();
238 if (n->is_Allocate()) {
239 n->as_Allocate()->_is_non_escaping = noescape;
240 }
241 if (n->is_CallStaticJava()) {
242 n->as_CallStaticJava()->_is_non_escaping = noescape;
243 }
244 if (noescape && ptn->scalar_replaceable()) {
245 adjust_scalar_replaceable_state(ptn);
246 if (ptn->scalar_replaceable()) {
247 alloc_worklist.append(ptn->ideal_node());
248 }
249 }
250 }
251
252 #ifdef ASSERT
253 if (VerifyConnectionGraph) {
254 // Verify that graph is complete - no new edges could be added or needed.
255 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
256 java_objects_worklist, addp_worklist);
257 }
258 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
259 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
260 null_obj->edge_count() == 0 &&
261 !null_obj->arraycopy_src() &&
262 !null_obj->arraycopy_dst(), "sanity");
263 #endif
264
265 _collecting = false;
266
267 } // TracePhase t3("connectionGraph")
268
269 // 4. Optimize ideal graph based on EA information.
270 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
271 if (has_non_escaping_obj) {
272 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
273 }
274
275 #ifndef PRODUCT
276 if (PrintEscapeAnalysis) {
277 dump(ptnodes_worklist); // Dump ConnectionGraph
278 }
279 #endif
280
281 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
282 #ifdef ASSERT
283 if (VerifyConnectionGraph) {
284 int alloc_length = alloc_worklist.length();
285 for (int next = 0; next < alloc_length; ++next) {
286 Node* n = alloc_worklist.at(next);
287 PointsToNode* ptn = ptnode_adr(n->_idx);
288 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
289 }
290 }
291 #endif
292
293 // 5. Separate memory graph for scalar replaceable allcations.
294 if (has_scalar_replaceable_candidates &&
295 C->AliasLevel() >= 3 && EliminateAllocations) {
296 // Now use the escape information to create unique types for
297 // scalar replaceable objects.
298 split_unique_types(alloc_worklist, arraycopy_worklist);
299 if (C->failing()) return false;
300 C->print_method(PHASE_AFTER_EA, 2);
301
302 #ifdef ASSERT
303 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
304 tty->print("=== No allocations eliminated for ");
305 C->method()->print_short_name();
306 if(!EliminateAllocations) {
307 tty->print(" since EliminateAllocations is off ===");
308 } else if(!has_scalar_replaceable_candidates) {
309 tty->print(" since there are no scalar replaceable candidates ===");
310 } else if(C->AliasLevel() < 3) {
311 tty->print(" since AliasLevel < 3 ===");
312 }
313 tty->cr();
314 #endif
315 }
316 return has_non_escaping_obj;
317 }
318
319 // Utility function for nodes that load an object
320 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
321 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
322 // ThreadLocal has RawPtr type.
323 const Type* t = _igvn->type(n);
324 if (t->make_ptr() != NULL) {
325 Node* adr = n->in(MemNode::Address);
326 #ifdef ASSERT
327 if (!adr->is_AddP()) {
328 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
329 } else {
330 assert((ptnode_adr(adr->_idx) == NULL ||
331 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
332 }
333 #endif
334 add_local_var_and_edge(n, PointsToNode::NoEscape,
335 adr, delayed_worklist);
336 }
337 }
338
339 // Populate Connection Graph with PointsTo nodes and create simple
340 // connection graph edges.
341 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
342 assert(!_verify, "this method should not be called for verification");
343 PhaseGVN* igvn = _igvn;
344 uint n_idx = n->_idx;
345 PointsToNode* n_ptn = ptnode_adr(n_idx);
346 if (n_ptn != NULL)
347 return; // No need to redefine PointsTo node during first iteration.
348
349 if (n->is_Call()) {
350 // Arguments to allocation and locking don't escape.
351 if (n->is_AbstractLock()) {
352 // Put Lock and Unlock nodes on IGVN worklist to process them during
353 // first IGVN optimization when escape information is still available.
354 record_for_optimizer(n);
355 } else if (n->is_Allocate()) {
356 add_call_node(n->as_Call());
357 record_for_optimizer(n);
358 } else {
359 if (n->is_CallStaticJava()) {
360 const char* name = n->as_CallStaticJava()->_name;
361 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
362 return; // Skip uncommon traps
363 }
364 // Don't mark as processed since call's arguments have to be processed.
365 delayed_worklist->push(n);
366 // Check if a call returns an object.
367 if ((n->as_Call()->returns_pointer() &&
368 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
369 (n->is_CallStaticJava() &&
370 n->as_CallStaticJava()->is_boxing_method())) {
371 add_call_node(n->as_Call());
372 }
373 }
374 return;
375 }
376 // Put this check here to process call arguments since some call nodes
377 // point to phantom_obj.
378 if (n_ptn == phantom_obj || n_ptn == null_obj)
379 return; // Skip predefined nodes.
380
381 int opcode = n->Opcode();
382 switch (opcode) {
383 case Op_AddP: {
384 Node* base = get_addp_base(n);
385 PointsToNode* ptn_base = ptnode_adr(base->_idx);
386 // Field nodes are created for all field types. They are used in
387 // adjust_scalar_replaceable_state() and split_unique_types().
388 // Note, non-oop fields will have only base edges in Connection
389 // Graph because such fields are not used for oop loads and stores.
390 int offset = address_offset(n, igvn);
391 add_field(n, PointsToNode::NoEscape, offset);
392 if (ptn_base == NULL) {
393 delayed_worklist->push(n); // Process it later.
394 } else {
395 n_ptn = ptnode_adr(n_idx);
396 add_base(n_ptn->as_Field(), ptn_base);
397 }
398 break;
399 }
400 case Op_CastX2P: {
401 map_ideal_node(n, phantom_obj);
402 break;
403 }
404 case Op_CastPP:
405 case Op_CheckCastPP:
406 case Op_EncodeP:
407 case Op_DecodeN:
408 case Op_EncodePKlass:
409 case Op_DecodeNKlass: {
410 add_local_var_and_edge(n, PointsToNode::NoEscape,
411 n->in(1), delayed_worklist);
412 break;
413 }
414 case Op_CMoveP: {
415 add_local_var(n, PointsToNode::NoEscape);
416 // Do not add edges during first iteration because some could be
417 // not defined yet.
418 delayed_worklist->push(n);
419 break;
420 }
421 case Op_ConP:
422 case Op_ConN:
423 case Op_ConNKlass: {
424 // assume all oop constants globally escape except for null
425 PointsToNode::EscapeState es;
426 const Type* t = igvn->type(n);
427 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
428 es = PointsToNode::NoEscape;
429 } else {
430 es = PointsToNode::GlobalEscape;
431 }
432 add_java_object(n, es);
433 break;
434 }
435 case Op_CreateEx: {
436 // assume that all exception objects globally escape
437 map_ideal_node(n, phantom_obj);
438 break;
439 }
440 case Op_LoadKlass:
441 case Op_LoadNKlass: {
442 // Unknown class is loaded
443 map_ideal_node(n, phantom_obj);
444 break;
445 }
446 case Op_LoadP:
447 case Op_LoadN:
448 case Op_LoadPLocked: {
449 add_objload_to_connection_graph(n, delayed_worklist);
450 break;
451 }
452 case Op_Parm: {
453 map_ideal_node(n, phantom_obj);
454 break;
455 }
456 case Op_PartialSubtypeCheck: {
457 // Produces Null or notNull and is used in only in CmpP so
458 // phantom_obj could be used.
459 map_ideal_node(n, phantom_obj); // Result is unknown
460 break;
461 }
462 case Op_Phi: {
463 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
464 // ThreadLocal has RawPtr type.
465 const Type* t = n->as_Phi()->type();
466 if (t->make_ptr() != NULL) {
467 add_local_var(n, PointsToNode::NoEscape);
468 // Do not add edges during first iteration because some could be
469 // not defined yet.
470 delayed_worklist->push(n);
471 }
472 break;
473 }
474 case Op_Proj: {
475 // we are only interested in the oop result projection from a call
476 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
477 n->in(0)->as_Call()->returns_pointer()) {
478 add_local_var_and_edge(n, PointsToNode::NoEscape,
479 n->in(0), delayed_worklist);
480 }
481 break;
482 }
483 case Op_Rethrow: // Exception object escapes
484 case Op_Return: {
485 if (n->req() > TypeFunc::Parms &&
486 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
487 // Treat Return value as LocalVar with GlobalEscape escape state.
488 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
489 n->in(TypeFunc::Parms), delayed_worklist);
490 }
491 break;
492 }
493 case Op_GetAndSetP:
494 case Op_GetAndSetN: {
495 add_objload_to_connection_graph(n, delayed_worklist);
496 // fallthrough
497 }
498 case Op_StoreP:
499 case Op_StoreN:
500 case Op_StoreNKlass:
501 case Op_StorePConditional:
502 case Op_CompareAndSwapP:
503 case Op_CompareAndSwapN: {
504 Node* adr = n->in(MemNode::Address);
505 const Type *adr_type = igvn->type(adr);
506 adr_type = adr_type->make_ptr();
507 if (adr_type == NULL) {
508 break; // skip dead nodes
509 }
510 if (adr_type->isa_oopptr() ||
511 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
512 (adr_type == TypeRawPtr::NOTNULL &&
513 adr->in(AddPNode::Address)->is_Proj() &&
514 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
515 delayed_worklist->push(n); // Process it later.
516 #ifdef ASSERT
517 assert(adr->is_AddP(), "expecting an AddP");
518 if (adr_type == TypeRawPtr::NOTNULL) {
519 // Verify a raw address for a store captured by Initialize node.
520 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
521 assert(offs != Type::OffsetBot, "offset must be a constant");
522 }
523 #endif
524 } else {
525 // Ignore copy the displaced header to the BoxNode (OSR compilation).
526 if (adr->is_BoxLock())
527 break;
528 // Stored value escapes in unsafe access.
529 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
530 // Pointer stores in G1 barriers looks like unsafe access.
531 // Ignore such stores to be able scalar replace non-escaping
532 // allocations.
533 if (UseG1GC && adr->is_AddP()) {
534 Node* base = get_addp_base(adr);
535 if (base->Opcode() == Op_LoadP &&
536 base->in(MemNode::Address)->is_AddP()) {
537 adr = base->in(MemNode::Address);
538 Node* tls = get_addp_base(adr);
539 if (tls->Opcode() == Op_ThreadLocal) {
540 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
541 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
542 SATBMarkQueue::byte_offset_of_buf())) {
543 break; // G1 pre barrier previous oop value store.
544 }
545 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
546 DirtyCardQueue::byte_offset_of_buf())) {
547 break; // G1 post barrier card address store.
548 }
549 }
550 }
551 }
552 delayed_worklist->push(n); // Process unsafe access later.
553 break;
554 }
555 #ifdef ASSERT
556 n->dump(1);
557 assert(false, "not unsafe or G1 barrier raw StoreP");
558 #endif
559 }
560 break;
561 }
562 case Op_AryEq:
563 case Op_HasNegatives:
564 case Op_StrComp:
565 case Op_StrEquals:
566 case Op_StrIndexOf:
567 case Op_StrIndexOfChar:
568 case Op_StrInflatedCopy:
569 case Op_StrCompressedCopy:
570 case Op_EncodeISOArray: {
571 add_local_var(n, PointsToNode::ArgEscape);
572 delayed_worklist->push(n); // Process it later.
573 break;
574 }
575 case Op_ThreadLocal: {
576 add_java_object(n, PointsToNode::ArgEscape);
577 break;
578 }
579 default:
580 ; // Do nothing for nodes not related to EA.
581 }
582 return;
583 }
584
585 #ifdef ASSERT
586 #define ELSE_FAIL(name) \
587 /* Should not be called for not pointer type. */ \
588 n->dump(1); \
589 assert(false, name); \
590 break;
591 #else
592 #define ELSE_FAIL(name) \
593 break;
594 #endif
595
596 // Add final simple edges to graph.
597 void ConnectionGraph::add_final_edges(Node *n) {
598 PointsToNode* n_ptn = ptnode_adr(n->_idx);
599 #ifdef ASSERT
600 if (_verify && n_ptn->is_JavaObject())
601 return; // This method does not change graph for JavaObject.
602 #endif
603
604 if (n->is_Call()) {
605 process_call_arguments(n->as_Call());
606 return;
607 }
608 assert(n->is_Store() || n->is_LoadStore() ||
609 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
610 "node should be registered already");
611 int opcode = n->Opcode();
612 switch (opcode) {
613 case Op_AddP: {
614 Node* base = get_addp_base(n);
615 PointsToNode* ptn_base = ptnode_adr(base->_idx);
616 assert(ptn_base != NULL, "field's base should be registered");
617 add_base(n_ptn->as_Field(), ptn_base);
618 break;
619 }
620 case Op_CastPP:
621 case Op_CheckCastPP:
622 case Op_EncodeP:
623 case Op_DecodeN:
624 case Op_EncodePKlass:
625 case Op_DecodeNKlass: {
626 add_local_var_and_edge(n, PointsToNode::NoEscape,
627 n->in(1), NULL);
628 break;
629 }
630 case Op_CMoveP: {
631 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
632 Node* in = n->in(i);
633 if (in == NULL)
634 continue; // ignore NULL
635 Node* uncast_in = in->uncast();
636 if (uncast_in->is_top() || uncast_in == n)
637 continue; // ignore top or inputs which go back this node
638 PointsToNode* ptn = ptnode_adr(in->_idx);
639 assert(ptn != NULL, "node should be registered");
640 add_edge(n_ptn, ptn);
641 }
642 break;
643 }
644 case Op_LoadP:
645 case Op_LoadN:
646 case Op_LoadPLocked: {
647 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
648 // ThreadLocal has RawPtr type.
649 const Type* t = _igvn->type(n);
650 if (t->make_ptr() != NULL) {
651 Node* adr = n->in(MemNode::Address);
652 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
653 break;
654 }
655 ELSE_FAIL("Op_LoadP");
656 }
657 case Op_Phi: {
658 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
659 // ThreadLocal has RawPtr type.
660 const Type* t = n->as_Phi()->type();
661 if (t->make_ptr() != NULL) {
662 for (uint i = 1; i < n->req(); i++) {
663 Node* in = n->in(i);
664 if (in == NULL)
665 continue; // ignore NULL
666 Node* uncast_in = in->uncast();
667 if (uncast_in->is_top() || uncast_in == n)
668 continue; // ignore top or inputs which go back this node
669 PointsToNode* ptn = ptnode_adr(in->_idx);
670 assert(ptn != NULL, "node should be registered");
671 add_edge(n_ptn, ptn);
672 }
673 break;
674 }
675 ELSE_FAIL("Op_Phi");
676 }
677 case Op_Proj: {
678 // we are only interested in the oop result projection from a call
679 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
680 n->in(0)->as_Call()->returns_pointer()) {
681 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
682 break;
683 }
684 ELSE_FAIL("Op_Proj");
685 }
686 case Op_Rethrow: // Exception object escapes
687 case Op_Return: {
688 if (n->req() > TypeFunc::Parms &&
689 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
690 // Treat Return value as LocalVar with GlobalEscape escape state.
691 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
692 n->in(TypeFunc::Parms), NULL);
693 break;
694 }
695 ELSE_FAIL("Op_Return");
696 }
697 case Op_StoreP:
698 case Op_StoreN:
699 case Op_StoreNKlass:
700 case Op_StorePConditional:
701 case Op_CompareAndSwapP:
702 case Op_CompareAndSwapN:
703 case Op_GetAndSetP:
704 case Op_GetAndSetN: {
705 Node* adr = n->in(MemNode::Address);
706 const Type *adr_type = _igvn->type(adr);
707 adr_type = adr_type->make_ptr();
708 #ifdef ASSERT
709 if (adr_type == NULL) {
710 n->dump(1);
711 assert(adr_type != NULL, "dead node should not be on list");
712 break;
713 }
714 #endif
715 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
716 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
717 }
718 if (adr_type->isa_oopptr() ||
719 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
720 (adr_type == TypeRawPtr::NOTNULL &&
721 adr->in(AddPNode::Address)->is_Proj() &&
722 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
723 // Point Address to Value
724 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
725 assert(adr_ptn != NULL &&
726 adr_ptn->as_Field()->is_oop(), "node should be registered");
727 Node *val = n->in(MemNode::ValueIn);
728 PointsToNode* ptn = ptnode_adr(val->_idx);
729 assert(ptn != NULL, "node should be registered");
730 add_edge(adr_ptn, ptn);
731 break;
732 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
733 // Stored value escapes in unsafe access.
734 Node *val = n->in(MemNode::ValueIn);
735 PointsToNode* ptn = ptnode_adr(val->_idx);
736 assert(ptn != NULL, "node should be registered");
737 set_escape_state(ptn, PointsToNode::GlobalEscape);
738 // Add edge to object for unsafe access with offset.
739 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
740 assert(adr_ptn != NULL, "node should be registered");
741 if (adr_ptn->is_Field()) {
742 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
743 add_edge(adr_ptn, ptn);
744 }
745 break;
746 }
747 ELSE_FAIL("Op_StoreP");
748 }
749 case Op_AryEq:
750 case Op_HasNegatives:
751 case Op_StrComp:
752 case Op_StrEquals:
753 case Op_StrIndexOf:
754 case Op_StrIndexOfChar:
755 case Op_StrInflatedCopy:
756 case Op_StrCompressedCopy:
757 case Op_EncodeISOArray: {
758 // char[]/byte[] arrays passed to string intrinsic do not escape but
759 // they are not scalar replaceable. Adjust escape state for them.
760 // Start from in(2) edge since in(1) is memory edge.
761 for (uint i = 2; i < n->req(); i++) {
762 Node* adr = n->in(i);
763 const Type* at = _igvn->type(adr);
764 if (!adr->is_top() && at->isa_ptr()) {
765 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
766 at->isa_ptr() != NULL, "expecting a pointer");
767 if (adr->is_AddP()) {
768 adr = get_addp_base(adr);
769 }
770 PointsToNode* ptn = ptnode_adr(adr->_idx);
771 assert(ptn != NULL, "node should be registered");
772 add_edge(n_ptn, ptn);
773 }
774 }
775 break;
776 }
777 default: {
778 // This method should be called only for EA specific nodes which may
779 // miss some edges when they were created.
780 #ifdef ASSERT
781 n->dump(1);
782 #endif
783 guarantee(false, "unknown node");
784 }
785 }
786 return;
787 }
788
789 void ConnectionGraph::add_call_node(CallNode* call) {
790 assert(call->returns_pointer(), "only for call which returns pointer");
791 uint call_idx = call->_idx;
792 if (call->is_Allocate()) {
793 Node* k = call->in(AllocateNode::KlassNode);
794 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
795 assert(kt != NULL, "TypeKlassPtr required.");
796 ciKlass* cik = kt->klass();
797 PointsToNode::EscapeState es = PointsToNode::NoEscape;
798 bool scalar_replaceable = true;
799 if (call->is_AllocateArray()) {
800 if (!cik->is_array_klass()) { // StressReflectiveCode
801 es = PointsToNode::GlobalEscape;
802 } else {
803 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
804 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
805 // Not scalar replaceable if the length is not constant or too big.
806 scalar_replaceable = false;
807 }
808 }
809 } else { // Allocate instance
810 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
811 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
812 !cik->is_instance_klass() || // StressReflectiveCode
813 cik->as_instance_klass()->has_finalizer()) {
814 es = PointsToNode::GlobalEscape;
815 }
816 }
817 add_java_object(call, es);
818 PointsToNode* ptn = ptnode_adr(call_idx);
819 if (!scalar_replaceable && ptn->scalar_replaceable()) {
820 ptn->set_scalar_replaceable(false);
821 }
822 } else if (call->is_CallStaticJava()) {
823 // Call nodes could be different types:
824 //
825 // 1. CallDynamicJavaNode (what happened during call is unknown):
826 //
827 // - mapped to GlobalEscape JavaObject node if oop is returned;
828 //
829 // - all oop arguments are escaping globally;
830 //
831 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
832 //
833 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
834 //
835 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
836 // - mapped to NoEscape JavaObject node if non-escaping object allocated
837 // during call is returned;
838 // - mapped to ArgEscape LocalVar node pointed to object arguments
839 // which are returned and does not escape during call;
840 //
841 // - oop arguments escaping status is defined by bytecode analysis;
842 //
843 // For a static call, we know exactly what method is being called.
844 // Use bytecode estimator to record whether the call's return value escapes.
845 ciMethod* meth = call->as_CallJava()->method();
846 if (meth == NULL) {
847 const char* name = call->as_CallStaticJava()->_name;
848 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
849 // Returns a newly allocated unescaped object.
850 add_java_object(call, PointsToNode::NoEscape);
851 ptnode_adr(call_idx)->set_scalar_replaceable(false);
852 } else if (meth->is_boxing_method()) {
853 // Returns boxing object
854 PointsToNode::EscapeState es;
855 vmIntrinsics::ID intr = meth->intrinsic_id();
856 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
857 // It does not escape if object is always allocated.
858 es = PointsToNode::NoEscape;
859 } else {
860 // It escapes globally if object could be loaded from cache.
861 es = PointsToNode::GlobalEscape;
862 }
863 add_java_object(call, es);
864 } else {
865 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
866 call_analyzer->copy_dependencies(_compile->dependencies());
867 if (call_analyzer->is_return_allocated()) {
868 // Returns a newly allocated unescaped object, simply
869 // update dependency information.
870 // Mark it as NoEscape so that objects referenced by
871 // it's fields will be marked as NoEscape at least.
872 add_java_object(call, PointsToNode::NoEscape);
873 ptnode_adr(call_idx)->set_scalar_replaceable(false);
874 } else {
875 // Determine whether any arguments are returned.
876 const TypeTuple* d = call->tf()->domain();
877 bool ret_arg = false;
878 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
879 if (d->field_at(i)->isa_ptr() != NULL &&
880 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
881 ret_arg = true;
882 break;
883 }
884 }
885 if (ret_arg) {
886 add_local_var(call, PointsToNode::ArgEscape);
887 } else {
888 // Returns unknown object.
889 map_ideal_node(call, phantom_obj);
890 }
891 }
892 }
893 } else {
894 // An other type of call, assume the worst case:
895 // returned value is unknown and globally escapes.
896 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
897 map_ideal_node(call, phantom_obj);
898 }
899 }
900
901 void ConnectionGraph::process_call_arguments(CallNode *call) {
902 bool is_arraycopy = false;
903 switch (call->Opcode()) {
904 #ifdef ASSERT
905 case Op_Allocate:
906 case Op_AllocateArray:
907 case Op_Lock:
908 case Op_Unlock:
909 assert(false, "should be done already");
910 break;
911 #endif
912 case Op_ArrayCopy:
913 case Op_CallLeafNoFP:
914 // Most array copies are ArrayCopy nodes at this point but there
915 // are still a few direct calls to the copy subroutines (See
916 // PhaseStringOpts::copy_string())
917 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
918 call->as_CallLeaf()->is_call_to_arraycopystub();
919 // fall through
920 case Op_CallLeaf: {
921 // Stub calls, objects do not escape but they are not scale replaceable.
922 // Adjust escape state for outgoing arguments.
923 const TypeTuple * d = call->tf()->domain();
924 bool src_has_oops = false;
925 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
926 const Type* at = d->field_at(i);
927 Node *arg = call->in(i);
928 if (arg == NULL) {
929 continue;
930 }
931 const Type *aat = _igvn->type(arg);
932 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
933 continue;
934 if (arg->is_AddP()) {
935 //
936 // The inline_native_clone() case when the arraycopy stub is called
937 // after the allocation before Initialize and CheckCastPP nodes.
938 // Or normal arraycopy for object arrays case.
939 //
940 // Set AddP's base (Allocate) as not scalar replaceable since
941 // pointer to the base (with offset) is passed as argument.
942 //
943 arg = get_addp_base(arg);
944 }
945 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
946 assert(arg_ptn != NULL, "should be registered");
947 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
948 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
949 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
950 aat->isa_ptr() != NULL, "expecting an Ptr");
951 bool arg_has_oops = aat->isa_oopptr() &&
952 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
953 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
954 if (i == TypeFunc::Parms) {
955 src_has_oops = arg_has_oops;
956 }
957 //
958 // src or dst could be j.l.Object when other is basic type array:
959 //
960 // arraycopy(char[],0,Object*,0,size);
961 // arraycopy(Object*,0,char[],0,size);
962 //
963 // Don't add edges in such cases.
964 //
965 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
966 arg_has_oops && (i > TypeFunc::Parms);
967 #ifdef ASSERT
968 if (!(is_arraycopy ||
969 (call->as_CallLeaf()->_name != NULL &&
970 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
971 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
972 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
973 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
974 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
975 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
976 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
977 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
978 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
979 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
980 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
981 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
982 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
983 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
984 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
985 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
986 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
993 ))) {
994 call->dump();
995 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
996 }
997 #endif
998 // Always process arraycopy's destination object since
999 // we need to add all possible edges to references in
1000 // source object.
1001 if (arg_esc >= PointsToNode::ArgEscape &&
1002 !arg_is_arraycopy_dest) {
1003 continue;
1004 }
1005 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1006 if (call->is_ArrayCopy()) {
1007 ArrayCopyNode* ac = call->as_ArrayCopy();
1008 if (ac->is_clonebasic() ||
1009 ac->is_arraycopy_validated() ||
1010 ac->is_copyof_validated() ||
1011 ac->is_copyofrange_validated()) {
1012 es = PointsToNode::NoEscape;
1013 }
1014 }
1015 set_escape_state(arg_ptn, es);
1016 if (arg_is_arraycopy_dest) {
1017 Node* src = call->in(TypeFunc::Parms);
1018 if (src->is_AddP()) {
1019 src = get_addp_base(src);
1020 }
1021 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1022 assert(src_ptn != NULL, "should be registered");
1023 if (arg_ptn != src_ptn) {
1024 // Special arraycopy edge:
1025 // A destination object's field can't have the source object
1026 // as base since objects escape states are not related.
1027 // Only escape state of destination object's fields affects
1028 // escape state of fields in source object.
1029 add_arraycopy(call, es, src_ptn, arg_ptn);
1030 }
1031 }
1032 }
1033 }
1034 break;
1035 }
1036 case Op_CallStaticJava: {
1037 // For a static call, we know exactly what method is being called.
1038 // Use bytecode estimator to record the call's escape affects
1039 #ifdef ASSERT
1040 const char* name = call->as_CallStaticJava()->_name;
1041 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1042 #endif
1043 ciMethod* meth = call->as_CallJava()->method();
1044 if ((meth != NULL) && meth->is_boxing_method()) {
1045 break; // Boxing methods do not modify any oops.
1046 }
1047 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1048 // fall-through if not a Java method or no analyzer information
1049 if (call_analyzer != NULL) {
1050 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1051 const TypeTuple* d = call->tf()->domain();
1052 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1053 const Type* at = d->field_at(i);
1054 int k = i - TypeFunc::Parms;
1055 Node* arg = call->in(i);
1056 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1057 if (at->isa_ptr() != NULL &&
1058 call_analyzer->is_arg_returned(k)) {
1059 // The call returns arguments.
1060 if (call_ptn != NULL) { // Is call's result used?
1061 assert(call_ptn->is_LocalVar(), "node should be registered");
1062 assert(arg_ptn != NULL, "node should be registered");
1063 add_edge(call_ptn, arg_ptn);
1064 }
1065 }
1066 if (at->isa_oopptr() != NULL &&
1067 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1068 if (!call_analyzer->is_arg_stack(k)) {
1069 // The argument global escapes
1070 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1071 } else {
1072 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1073 if (!call_analyzer->is_arg_local(k)) {
1074 // The argument itself doesn't escape, but any fields might
1075 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1076 }
1077 }
1078 }
1079 }
1080 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1081 // The call returns arguments.
1082 assert(call_ptn->edge_count() > 0, "sanity");
1083 if (!call_analyzer->is_return_local()) {
1084 // Returns also unknown object.
1085 add_edge(call_ptn, phantom_obj);
1086 }
1087 }
1088 break;
1089 }
1090 }
1091 default: {
1092 // Fall-through here if not a Java method or no analyzer information
1093 // or some other type of call, assume the worst case: all arguments
1094 // globally escape.
1095 const TypeTuple* d = call->tf()->domain();
1096 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1097 const Type* at = d->field_at(i);
1098 if (at->isa_oopptr() != NULL) {
1099 Node* arg = call->in(i);
1100 if (arg->is_AddP()) {
1101 arg = get_addp_base(arg);
1102 }
1103 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1104 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1105 }
1106 }
1107 }
1108 }
1109 }
1110
1111
1112 // Finish Graph construction.
1113 bool ConnectionGraph::complete_connection_graph(
1114 GrowableArray<PointsToNode*>& ptnodes_worklist,
1115 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1116 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1117 GrowableArray<FieldNode*>& oop_fields_worklist) {
1118 // Normally only 1-3 passes needed to build Connection Graph depending
1119 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1120 // Set limit to 20 to catch situation when something did go wrong and
1121 // bailout Escape Analysis.
1122 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1123 #define CG_BUILD_ITER_LIMIT 20
1124
1125 // Propagate GlobalEscape and ArgEscape escape states and check that
1126 // we still have non-escaping objects. The method pushs on _worklist
1127 // Field nodes which reference phantom_object.
1128 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1129 return false; // Nothing to do.
1130 }
1131 // Now propagate references to all JavaObject nodes.
1132 int java_objects_length = java_objects_worklist.length();
1133 elapsedTimer time;
1134 bool timeout = false;
1135 int new_edges = 1;
1136 int iterations = 0;
1137 do {
1138 while ((new_edges > 0) &&
1139 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1140 double start_time = time.seconds();
1141 time.start();
1142 new_edges = 0;
1143 // Propagate references to phantom_object for nodes pushed on _worklist
1144 // by find_non_escaped_objects() and find_field_value().
1145 new_edges += add_java_object_edges(phantom_obj, false);
1146 for (int next = 0; next < java_objects_length; ++next) {
1147 JavaObjectNode* ptn = java_objects_worklist.at(next);
1148 new_edges += add_java_object_edges(ptn, true);
1149
1150 #define SAMPLE_SIZE 4
1151 if ((next % SAMPLE_SIZE) == 0) {
1152 // Each 4 iterations calculate how much time it will take
1153 // to complete graph construction.
1154 time.stop();
1155 // Poll for requests from shutdown mechanism to quiesce compiler
1156 // because Connection graph construction may take long time.
1157 CompileBroker::maybe_block();
1158 double stop_time = time.seconds();
1159 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1160 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1161 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1162 timeout = true;
1163 break; // Timeout
1164 }
1165 start_time = stop_time;
1166 time.start();
1167 }
1168 #undef SAMPLE_SIZE
1169
1170 }
1171 if (timeout) break;
1172 if (new_edges > 0) {
1173 // Update escape states on each iteration if graph was updated.
1174 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1175 return false; // Nothing to do.
1176 }
1177 }
1178 time.stop();
1179 if (time.seconds() >= EscapeAnalysisTimeout) {
1180 timeout = true;
1181 break;
1182 }
1183 }
1184 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1185 time.start();
1186 // Find fields which have unknown value.
1187 int fields_length = oop_fields_worklist.length();
1188 for (int next = 0; next < fields_length; next++) {
1189 FieldNode* field = oop_fields_worklist.at(next);
1190 if (field->edge_count() == 0) {
1191 new_edges += find_field_value(field);
1192 // This code may added new edges to phantom_object.
1193 // Need an other cycle to propagate references to phantom_object.
1194 }
1195 }
1196 time.stop();
1197 if (time.seconds() >= EscapeAnalysisTimeout) {
1198 timeout = true;
1199 break;
1200 }
1201 } else {
1202 new_edges = 0; // Bailout
1203 }
1204 } while (new_edges > 0);
1205
1206 // Bailout if passed limits.
1207 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1208 Compile* C = _compile;
1209 if (C->log() != NULL) {
1210 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1211 C->log()->text("%s", timeout ? "time" : "iterations");
1212 C->log()->end_elem(" limit'");
1213 }
1214 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1215 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1216 // Possible infinite build_connection_graph loop,
1217 // bailout (no changes to ideal graph were made).
1218 return false;
1219 }
1220 #ifdef ASSERT
1221 if (Verbose && PrintEscapeAnalysis) {
1222 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1223 iterations, nodes_size(), ptnodes_worklist.length());
1224 }
1225 #endif
1226
1227 #undef CG_BUILD_ITER_LIMIT
1228
1229 // Find fields initialized by NULL for non-escaping Allocations.
1230 int non_escaped_length = non_escaped_worklist.length();
1231 for (int next = 0; next < non_escaped_length; next++) {
1232 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1233 PointsToNode::EscapeState es = ptn->escape_state();
1234 assert(es <= PointsToNode::ArgEscape, "sanity");
1235 if (es == PointsToNode::NoEscape) {
1236 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1237 // Adding references to NULL object does not change escape states
1238 // since it does not escape. Also no fields are added to NULL object.
1239 add_java_object_edges(null_obj, false);
1240 }
1241 }
1242 Node* n = ptn->ideal_node();
1243 if (n->is_Allocate()) {
1244 // The object allocated by this Allocate node will never be
1245 // seen by an other thread. Mark it so that when it is
1246 // expanded no MemBarStoreStore is added.
1247 InitializeNode* ini = n->as_Allocate()->initialization();
1248 if (ini != NULL)
1249 ini->set_does_not_escape();
1250 }
1251 }
1252 return true; // Finished graph construction.
1253 }
1254
1255 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1256 // and check that we still have non-escaping java objects.
1257 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1258 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1259 GrowableArray<PointsToNode*> escape_worklist;
1260 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1261 int ptnodes_length = ptnodes_worklist.length();
1262 for (int next = 0; next < ptnodes_length; ++next) {
1263 PointsToNode* ptn = ptnodes_worklist.at(next);
1264 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1265 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1266 escape_worklist.push(ptn);
1267 }
1268 }
1269 // Set escape states to referenced nodes (edges list).
1270 while (escape_worklist.length() > 0) {
1271 PointsToNode* ptn = escape_worklist.pop();
1272 PointsToNode::EscapeState es = ptn->escape_state();
1273 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1274 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1275 es >= PointsToNode::ArgEscape) {
1276 // GlobalEscape or ArgEscape state of field means it has unknown value.
1277 if (add_edge(ptn, phantom_obj)) {
1278 // New edge was added
1279 add_field_uses_to_worklist(ptn->as_Field());
1280 }
1281 }
1282 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1283 PointsToNode* e = i.get();
1284 if (e->is_Arraycopy()) {
1285 assert(ptn->arraycopy_dst(), "sanity");
1286 // Propagate only fields escape state through arraycopy edge.
1287 if (e->fields_escape_state() < field_es) {
1288 set_fields_escape_state(e, field_es);
1289 escape_worklist.push(e);
1290 }
1291 } else if (es >= field_es) {
1292 // fields_escape_state is also set to 'es' if it is less than 'es'.
1293 if (e->escape_state() < es) {
1294 set_escape_state(e, es);
1295 escape_worklist.push(e);
1296 }
1297 } else {
1298 // Propagate field escape state.
1299 bool es_changed = false;
1300 if (e->fields_escape_state() < field_es) {
1301 set_fields_escape_state(e, field_es);
1302 es_changed = true;
1303 }
1304 if ((e->escape_state() < field_es) &&
1305 e->is_Field() && ptn->is_JavaObject() &&
1306 e->as_Field()->is_oop()) {
1307 // Change escape state of referenced fields.
1308 set_escape_state(e, field_es);
1309 es_changed = true;
1310 } else if (e->escape_state() < es) {
1311 set_escape_state(e, es);
1312 es_changed = true;
1313 }
1314 if (es_changed) {
1315 escape_worklist.push(e);
1316 }
1317 }
1318 }
1319 }
1320 // Remove escaped objects from non_escaped list.
1321 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1322 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1323 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1324 non_escaped_worklist.delete_at(next);
1325 }
1326 if (ptn->escape_state() == PointsToNode::NoEscape) {
1327 // Find fields in non-escaped allocations which have unknown value.
1328 find_init_values(ptn, phantom_obj, NULL);
1329 }
1330 }
1331 return (non_escaped_worklist.length() > 0);
1332 }
1333
1334 // Add all references to JavaObject node by walking over all uses.
1335 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1336 int new_edges = 0;
1337 if (populate_worklist) {
1338 // Populate _worklist by uses of jobj's uses.
1339 for (UseIterator i(jobj); i.has_next(); i.next()) {
1340 PointsToNode* use = i.get();
1341 if (use->is_Arraycopy())
1342 continue;
1343 add_uses_to_worklist(use);
1344 if (use->is_Field() && use->as_Field()->is_oop()) {
1345 // Put on worklist all field's uses (loads) and
1346 // related field nodes (same base and offset).
1347 add_field_uses_to_worklist(use->as_Field());
1348 }
1349 }
1350 }
1351 for (int l = 0; l < _worklist.length(); l++) {
1352 PointsToNode* use = _worklist.at(l);
1353 if (PointsToNode::is_base_use(use)) {
1354 // Add reference from jobj to field and from field to jobj (field's base).
1355 use = PointsToNode::get_use_node(use)->as_Field();
1356 if (add_base(use->as_Field(), jobj)) {
1357 new_edges++;
1358 }
1359 continue;
1360 }
1361 assert(!use->is_JavaObject(), "sanity");
1362 if (use->is_Arraycopy()) {
1363 if (jobj == null_obj) // NULL object does not have field edges
1364 continue;
1365 // Added edge from Arraycopy node to arraycopy's source java object
1366 if (add_edge(use, jobj)) {
1367 jobj->set_arraycopy_src();
1368 new_edges++;
1369 }
1370 // and stop here.
1371 continue;
1372 }
1373 if (!add_edge(use, jobj))
1374 continue; // No new edge added, there was such edge already.
1375 new_edges++;
1376 if (use->is_LocalVar()) {
1377 add_uses_to_worklist(use);
1378 if (use->arraycopy_dst()) {
1379 for (EdgeIterator i(use); i.has_next(); i.next()) {
1380 PointsToNode* e = i.get();
1381 if (e->is_Arraycopy()) {
1382 if (jobj == null_obj) // NULL object does not have field edges
1383 continue;
1384 // Add edge from arraycopy's destination java object to Arraycopy node.
1385 if (add_edge(jobj, e)) {
1386 new_edges++;
1387 jobj->set_arraycopy_dst();
1388 }
1389 }
1390 }
1391 }
1392 } else {
1393 // Added new edge to stored in field values.
1394 // Put on worklist all field's uses (loads) and
1395 // related field nodes (same base and offset).
1396 add_field_uses_to_worklist(use->as_Field());
1397 }
1398 }
1399 _worklist.clear();
1400 _in_worklist.Reset();
1401 return new_edges;
1402 }
1403
1404 // Put on worklist all related field nodes.
1405 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1406 assert(field->is_oop(), "sanity");
1407 int offset = field->offset();
1408 add_uses_to_worklist(field);
1409 // Loop over all bases of this field and push on worklist Field nodes
1410 // with the same offset and base (since they may reference the same field).
1411 for (BaseIterator i(field); i.has_next(); i.next()) {
1412 PointsToNode* base = i.get();
1413 add_fields_to_worklist(field, base);
1414 // Check if the base was source object of arraycopy and go over arraycopy's
1415 // destination objects since values stored to a field of source object are
1416 // accessable by uses (loads) of fields of destination objects.
1417 if (base->arraycopy_src()) {
1418 for (UseIterator j(base); j.has_next(); j.next()) {
1419 PointsToNode* arycp = j.get();
1420 if (arycp->is_Arraycopy()) {
1421 for (UseIterator k(arycp); k.has_next(); k.next()) {
1422 PointsToNode* abase = k.get();
1423 if (abase->arraycopy_dst() && abase != base) {
1424 // Look for the same arraycopy reference.
1425 add_fields_to_worklist(field, abase);
1426 }
1427 }
1428 }
1429 }
1430 }
1431 }
1432 }
1433
1434 // Put on worklist all related field nodes.
1435 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1436 int offset = field->offset();
1437 if (base->is_LocalVar()) {
1438 for (UseIterator j(base); j.has_next(); j.next()) {
1439 PointsToNode* f = j.get();
1440 if (PointsToNode::is_base_use(f)) { // Field
1441 f = PointsToNode::get_use_node(f);
1442 if (f == field || !f->as_Field()->is_oop())
1443 continue;
1444 int offs = f->as_Field()->offset();
1445 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1446 add_to_worklist(f);
1447 }
1448 }
1449 }
1450 } else {
1451 assert(base->is_JavaObject(), "sanity");
1452 if (// Skip phantom_object since it is only used to indicate that
1453 // this field's content globally escapes.
1454 (base != phantom_obj) &&
1455 // NULL object node does not have fields.
1456 (base != null_obj)) {
1457 for (EdgeIterator i(base); i.has_next(); i.next()) {
1458 PointsToNode* f = i.get();
1459 // Skip arraycopy edge since store to destination object field
1460 // does not update value in source object field.
1461 if (f->is_Arraycopy()) {
1462 assert(base->arraycopy_dst(), "sanity");
1463 continue;
1464 }
1465 if (f == field || !f->as_Field()->is_oop())
1466 continue;
1467 int offs = f->as_Field()->offset();
1468 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1469 add_to_worklist(f);
1470 }
1471 }
1472 }
1473 }
1474 }
1475
1476 // Find fields which have unknown value.
1477 int ConnectionGraph::find_field_value(FieldNode* field) {
1478 // Escaped fields should have init value already.
1479 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1480 int new_edges = 0;
1481 for (BaseIterator i(field); i.has_next(); i.next()) {
1482 PointsToNode* base = i.get();
1483 if (base->is_JavaObject()) {
1484 // Skip Allocate's fields which will be processed later.
1485 if (base->ideal_node()->is_Allocate())
1486 return 0;
1487 assert(base == null_obj, "only NULL ptr base expected here");
1488 }
1489 }
1490 if (add_edge(field, phantom_obj)) {
1491 // New edge was added
1492 new_edges++;
1493 add_field_uses_to_worklist(field);
1494 }
1495 return new_edges;
1496 }
1497
1498 // Find fields initializing values for allocations.
1499 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1500 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1501 int new_edges = 0;
1502 Node* alloc = pta->ideal_node();
1503 if (init_val == phantom_obj) {
1504 // Do nothing for Allocate nodes since its fields values are
1505 // "known" unless they are initialized by arraycopy/clone.
1506 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1507 return 0;
1508 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1509 #ifdef ASSERT
1510 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1511 const char* name = alloc->as_CallStaticJava()->_name;
1512 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1513 }
1514 #endif
1515 // Non-escaped allocation returned from Java or runtime call have
1516 // unknown values in fields.
1517 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1518 PointsToNode* field = i.get();
1519 if (field->is_Field() && field->as_Field()->is_oop()) {
1520 if (add_edge(field, phantom_obj)) {
1521 // New edge was added
1522 new_edges++;
1523 add_field_uses_to_worklist(field->as_Field());
1524 }
1525 }
1526 }
1527 return new_edges;
1528 }
1529 assert(init_val == null_obj, "sanity");
1530 // Do nothing for Call nodes since its fields values are unknown.
1531 if (!alloc->is_Allocate())
1532 return 0;
1533
1534 InitializeNode* ini = alloc->as_Allocate()->initialization();
1535 bool visited_bottom_offset = false;
1536 GrowableArray<int> offsets_worklist;
1537
1538 // Check if an oop field's initializing value is recorded and add
1539 // a corresponding NULL if field's value if it is not recorded.
1540 // Connection Graph does not record a default initialization by NULL
1541 // captured by Initialize node.
1542 //
1543 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1544 PointsToNode* field = i.get(); // Field (AddP)
1545 if (!field->is_Field() || !field->as_Field()->is_oop())
1546 continue; // Not oop field
1547 int offset = field->as_Field()->offset();
1548 if (offset == Type::OffsetBot) {
1549 if (!visited_bottom_offset) {
1550 // OffsetBot is used to reference array's element,
1551 // always add reference to NULL to all Field nodes since we don't
1552 // known which element is referenced.
1553 if (add_edge(field, null_obj)) {
1554 // New edge was added
1555 new_edges++;
1556 add_field_uses_to_worklist(field->as_Field());
1557 visited_bottom_offset = true;
1558 }
1559 }
1560 } else {
1561 // Check only oop fields.
1562 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1563 if (adr_type->isa_rawptr()) {
1564 #ifdef ASSERT
1565 // Raw pointers are used for initializing stores so skip it
1566 // since it should be recorded already
1567 Node* base = get_addp_base(field->ideal_node());
1568 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1569 (base->in(0) == alloc),"unexpected pointer type");
1570 #endif
1571 continue;
1572 }
1573 if (!offsets_worklist.contains(offset)) {
1574 offsets_worklist.append(offset);
1575 Node* value = NULL;
1576 if (ini != NULL) {
1577 // StoreP::memory_type() == T_ADDRESS
1578 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1579 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1580 // Make sure initializing store has the same type as this AddP.
1581 // This AddP may reference non existing field because it is on a
1582 // dead branch of bimorphic call which is not eliminated yet.
1583 if (store != NULL && store->is_Store() &&
1584 store->as_Store()->memory_type() == ft) {
1585 value = store->in(MemNode::ValueIn);
1586 #ifdef ASSERT
1587 if (VerifyConnectionGraph) {
1588 // Verify that AddP already points to all objects the value points to.
1589 PointsToNode* val = ptnode_adr(value->_idx);
1590 assert((val != NULL), "should be processed already");
1591 PointsToNode* missed_obj = NULL;
1592 if (val->is_JavaObject()) {
1593 if (!field->points_to(val->as_JavaObject())) {
1594 missed_obj = val;
1595 }
1596 } else {
1597 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1598 tty->print_cr("----------init store has invalid value -----");
1599 store->dump();
1600 val->dump();
1601 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1602 }
1603 for (EdgeIterator j(val); j.has_next(); j.next()) {
1604 PointsToNode* obj = j.get();
1605 if (obj->is_JavaObject()) {
1606 if (!field->points_to(obj->as_JavaObject())) {
1607 missed_obj = obj;
1608 break;
1609 }
1610 }
1611 }
1612 }
1613 if (missed_obj != NULL) {
1614 tty->print_cr("----------field---------------------------------");
1615 field->dump();
1616 tty->print_cr("----------missed referernce to object-----------");
1617 missed_obj->dump();
1618 tty->print_cr("----------object referernced by init store -----");
1619 store->dump();
1620 val->dump();
1621 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1622 }
1623 }
1624 #endif
1625 } else {
1626 // There could be initializing stores which follow allocation.
1627 // For example, a volatile field store is not collected
1628 // by Initialize node.
1629 //
1630 // Need to check for dependent loads to separate such stores from
1631 // stores which follow loads. For now, add initial value NULL so
1632 // that compare pointers optimization works correctly.
1633 }
1634 }
1635 if (value == NULL) {
1636 // A field's initializing value was not recorded. Add NULL.
1637 if (add_edge(field, null_obj)) {
1638 // New edge was added
1639 new_edges++;
1640 add_field_uses_to_worklist(field->as_Field());
1641 }
1642 }
1643 }
1644 }
1645 }
1646 return new_edges;
1647 }
1648
1649 // Adjust scalar_replaceable state after Connection Graph is built.
1650 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1651 // Search for non-escaping objects which are not scalar replaceable
1652 // and mark them to propagate the state to referenced objects.
1653
1654 // 1. An object is not scalar replaceable if the field into which it is
1655 // stored has unknown offset (stored into unknown element of an array).
1656 //
1657 for (UseIterator i(jobj); i.has_next(); i.next()) {
1658 PointsToNode* use = i.get();
1659 if (use->is_Arraycopy()) {
1660 continue;
1661 }
1662 if (use->is_Field()) {
1663 FieldNode* field = use->as_Field();
1664 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1665 if (field->offset() == Type::OffsetBot) {
1666 jobj->set_scalar_replaceable(false);
1667 return;
1668 }
1669 // 2. An object is not scalar replaceable if the field into which it is
1670 // stored has multiple bases one of which is null.
1671 if (field->base_count() > 1) {
1672 for (BaseIterator i(field); i.has_next(); i.next()) {
1673 PointsToNode* base = i.get();
1674 if (base == null_obj) {
1675 jobj->set_scalar_replaceable(false);
1676 return;
1677 }
1678 }
1679 }
1680 }
1681 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1682 // 3. An object is not scalar replaceable if it is merged with other objects.
1683 for (EdgeIterator j(use); j.has_next(); j.next()) {
1684 PointsToNode* ptn = j.get();
1685 if (ptn->is_JavaObject() && ptn != jobj) {
1686 // Mark all objects.
1687 jobj->set_scalar_replaceable(false);
1688 ptn->set_scalar_replaceable(false);
1689 }
1690 }
1691 if (!jobj->scalar_replaceable()) {
1692 return;
1693 }
1694 }
1695
1696 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1697 if (j.get()->is_Arraycopy()) {
1698 continue;
1699 }
1700
1701 // Non-escaping object node should point only to field nodes.
1702 FieldNode* field = j.get()->as_Field();
1703 int offset = field->as_Field()->offset();
1704
1705 // 4. An object is not scalar replaceable if it has a field with unknown
1706 // offset (array's element is accessed in loop).
1707 if (offset == Type::OffsetBot) {
1708 jobj->set_scalar_replaceable(false);
1709 return;
1710 }
1711 // 5. Currently an object is not scalar replaceable if a LoadStore node
1712 // access its field since the field value is unknown after it.
1713 //
1714 Node* n = field->ideal_node();
1715 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1716 if (n->fast_out(i)->is_LoadStore()) {
1717 jobj->set_scalar_replaceable(false);
1718 return;
1719 }
1720 }
1721
1722 // 6. Or the address may point to more then one object. This may produce
1723 // the false positive result (set not scalar replaceable)
1724 // since the flow-insensitive escape analysis can't separate
1725 // the case when stores overwrite the field's value from the case
1726 // when stores happened on different control branches.
1727 //
1728 // Note: it will disable scalar replacement in some cases:
1729 //
1730 // Point p[] = new Point[1];
1731 // p[0] = new Point(); // Will be not scalar replaced
1732 //
1733 // but it will save us from incorrect optimizations in next cases:
1734 //
1735 // Point p[] = new Point[1];
1736 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1737 //
1738 if (field->base_count() > 1) {
1739 for (BaseIterator i(field); i.has_next(); i.next()) {
1740 PointsToNode* base = i.get();
1741 // Don't take into account LocalVar nodes which
1742 // may point to only one object which should be also
1743 // this field's base by now.
1744 if (base->is_JavaObject() && base != jobj) {
1745 // Mark all bases.
1746 jobj->set_scalar_replaceable(false);
1747 base->set_scalar_replaceable(false);
1748 }
1749 }
1750 }
1751 }
1752 }
1753
1754 #ifdef ASSERT
1755 void ConnectionGraph::verify_connection_graph(
1756 GrowableArray<PointsToNode*>& ptnodes_worklist,
1757 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1758 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1759 GrowableArray<Node*>& addp_worklist) {
1760 // Verify that graph is complete - no new edges could be added.
1761 int java_objects_length = java_objects_worklist.length();
1762 int non_escaped_length = non_escaped_worklist.length();
1763 int new_edges = 0;
1764 for (int next = 0; next < java_objects_length; ++next) {
1765 JavaObjectNode* ptn = java_objects_worklist.at(next);
1766 new_edges += add_java_object_edges(ptn, true);
1767 }
1768 assert(new_edges == 0, "graph was not complete");
1769 // Verify that escape state is final.
1770 int length = non_escaped_worklist.length();
1771 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1772 assert((non_escaped_length == non_escaped_worklist.length()) &&
1773 (non_escaped_length == length) &&
1774 (_worklist.length() == 0), "escape state was not final");
1775
1776 // Verify fields information.
1777 int addp_length = addp_worklist.length();
1778 for (int next = 0; next < addp_length; ++next ) {
1779 Node* n = addp_worklist.at(next);
1780 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1781 if (field->is_oop()) {
1782 // Verify that field has all bases
1783 Node* base = get_addp_base(n);
1784 PointsToNode* ptn = ptnode_adr(base->_idx);
1785 if (ptn->is_JavaObject()) {
1786 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1787 } else {
1788 assert(ptn->is_LocalVar(), "sanity");
1789 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1790 PointsToNode* e = i.get();
1791 if (e->is_JavaObject()) {
1792 assert(field->has_base(e->as_JavaObject()), "sanity");
1793 }
1794 }
1795 }
1796 // Verify that all fields have initializing values.
1797 if (field->edge_count() == 0) {
1798 tty->print_cr("----------field does not have references----------");
1799 field->dump();
1800 for (BaseIterator i(field); i.has_next(); i.next()) {
1801 PointsToNode* base = i.get();
1802 tty->print_cr("----------field has next base---------------------");
1803 base->dump();
1804 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1805 tty->print_cr("----------base has fields-------------------------");
1806 for (EdgeIterator j(base); j.has_next(); j.next()) {
1807 j.get()->dump();
1808 }
1809 tty->print_cr("----------base has references---------------------");
1810 for (UseIterator j(base); j.has_next(); j.next()) {
1811 j.get()->dump();
1812 }
1813 }
1814 }
1815 for (UseIterator i(field); i.has_next(); i.next()) {
1816 i.get()->dump();
1817 }
1818 assert(field->edge_count() > 0, "sanity");
1819 }
1820 }
1821 }
1822 }
1823 #endif
1824
1825 // Optimize ideal graph.
1826 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1827 GrowableArray<Node*>& storestore_worklist) {
1828 Compile* C = _compile;
1829 PhaseIterGVN* igvn = _igvn;
1830 if (EliminateLocks) {
1831 // Mark locks before changing ideal graph.
1832 int cnt = C->macro_count();
1833 for( int i=0; i < cnt; i++ ) {
1834 Node *n = C->macro_node(i);
1835 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1836 AbstractLockNode* alock = n->as_AbstractLock();
1837 if (!alock->is_non_esc_obj()) {
1838 if (not_global_escape(alock->obj_node())) {
1839 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1840 // The lock could be marked eliminated by lock coarsening
1841 // code during first IGVN before EA. Replace coarsened flag
1842 // to eliminate all associated locks/unlocks.
1843 #ifdef ASSERT
1844 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1845 #endif
1846 alock->set_non_esc_obj();
1847 }
1848 }
1849 }
1850 }
1851 }
1852
1853 if (OptimizePtrCompare) {
1854 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1855 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1856 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1857 // Optimize objects compare.
1858 while (ptr_cmp_worklist.length() != 0) {
1859 Node *n = ptr_cmp_worklist.pop();
1860 Node *res = optimize_ptr_compare(n);
1861 if (res != NULL) {
1862 #ifndef PRODUCT
1863 if (PrintOptimizePtrCompare) {
1864 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"));
1865 if (Verbose) {
1866 n->dump(1);
1867 }
1868 }
1869 #endif
1870 igvn->replace_node(n, res);
1871 }
1872 }
1873 // cleanup
1874 if (_pcmp_neq->outcnt() == 0)
1875 igvn->hash_delete(_pcmp_neq);
1876 if (_pcmp_eq->outcnt() == 0)
1877 igvn->hash_delete(_pcmp_eq);
1878 }
1879
1880 // For MemBarStoreStore nodes added in library_call.cpp, check
1881 // escape status of associated AllocateNode and optimize out
1882 // MemBarStoreStore node if the allocated object never escapes.
1883 while (storestore_worklist.length() != 0) {
1884 Node *n = storestore_worklist.pop();
1885 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1886 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1887 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1888 if (not_global_escape(alloc)) {
1889 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1890 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1891 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1892 igvn->register_new_node_with_optimizer(mb);
1893 igvn->replace_node(storestore, mb);
1894 }
1895 }
1896 }
1897
1898 // Optimize objects compare.
1899 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1900 assert(OptimizePtrCompare, "sanity");
1901 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1902 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1903 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1904 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1905 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1906 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1907
1908 // Check simple cases first.
1909 if (jobj1 != NULL) {
1910 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1911 if (jobj1 == jobj2) {
1912 // Comparing the same not escaping object.
1913 return _pcmp_eq;
1914 }
1915 Node* obj = jobj1->ideal_node();
1916 // Comparing not escaping allocation.
1917 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1918 !ptn2->points_to(jobj1)) {
1919 return _pcmp_neq; // This includes nullness check.
1920 }
1921 }
1922 }
1923 if (jobj2 != NULL) {
1924 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1925 Node* obj = jobj2->ideal_node();
1926 // Comparing not escaping allocation.
1927 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1928 !ptn1->points_to(jobj2)) {
1929 return _pcmp_neq; // This includes nullness check.
1930 }
1931 }
1932 }
1933 if (jobj1 != NULL && jobj1 != phantom_obj &&
1934 jobj2 != NULL && jobj2 != phantom_obj &&
1935 jobj1->ideal_node()->is_Con() &&
1936 jobj2->ideal_node()->is_Con()) {
1937 // Klass or String constants compare. Need to be careful with
1938 // compressed pointers - compare types of ConN and ConP instead of nodes.
1939 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1940 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1941 if (t1->make_ptr() == t2->make_ptr()) {
1942 return _pcmp_eq;
1943 } else {
1944 return _pcmp_neq;
1945 }
1946 }
1947 if (ptn1->meet(ptn2)) {
1948 return NULL; // Sets are not disjoint
1949 }
1950
1951 // Sets are disjoint.
1952 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1953 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1954 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1955 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1956 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1957 set2_has_unknown_ptr && set1_has_null_ptr) {
1958 // Check nullness of unknown object.
1959 return NULL;
1960 }
1961
1962 // Disjointness by itself is not sufficient since
1963 // alias analysis is not complete for escaped objects.
1964 // Disjoint sets are definitely unrelated only when
1965 // at least one set has only not escaping allocations.
1966 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1967 if (ptn1->non_escaping_allocation()) {
1968 return _pcmp_neq;
1969 }
1970 }
1971 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1972 if (ptn2->non_escaping_allocation()) {
1973 return _pcmp_neq;
1974 }
1975 }
1976 return NULL;
1977 }
1978
1979 // Connection Graph constuction functions.
1980
1981 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1982 PointsToNode* ptadr = _nodes.at(n->_idx);
1983 if (ptadr != NULL) {
1984 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1985 return;
1986 }
1987 Compile* C = _compile;
1988 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
1989 _nodes.at_put(n->_idx, ptadr);
1990 }
1991
1992 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1993 PointsToNode* ptadr = _nodes.at(n->_idx);
1994 if (ptadr != NULL) {
1995 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1996 return;
1997 }
1998 Compile* C = _compile;
1999 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2000 _nodes.at_put(n->_idx, ptadr);
2001 }
2002
2003 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2004 PointsToNode* ptadr = _nodes.at(n->_idx);
2005 if (ptadr != NULL) {
2006 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2007 return;
2008 }
2009 bool unsafe = false;
2010 bool is_oop = is_oop_field(n, offset, &unsafe);
2011 if (unsafe) {
2012 es = PointsToNode::GlobalEscape;
2013 }
2014 Compile* C = _compile;
2015 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2016 _nodes.at_put(n->_idx, field);
2017 }
2018
2019 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2020 PointsToNode* src, PointsToNode* dst) {
2021 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2022 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2023 PointsToNode* ptadr = _nodes.at(n->_idx);
2024 if (ptadr != NULL) {
2025 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2026 return;
2027 }
2028 Compile* C = _compile;
2029 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2030 _nodes.at_put(n->_idx, ptadr);
2031 // Add edge from arraycopy node to source object.
2032 (void)add_edge(ptadr, src);
2033 src->set_arraycopy_src();
2034 // Add edge from destination object to arraycopy node.
2035 (void)add_edge(dst, ptadr);
2036 dst->set_arraycopy_dst();
2037 }
2038
2039 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2040 const Type* adr_type = n->as_AddP()->bottom_type();
2041 BasicType bt = T_INT;
2042 if (offset == Type::OffsetBot) {
2043 // Check only oop fields.
2044 if (!adr_type->isa_aryptr() ||
2045 (adr_type->isa_aryptr()->klass() == NULL) ||
2046 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2047 // OffsetBot is used to reference array's element. Ignore first AddP.
2048 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2049 bt = T_OBJECT;
2050 }
2051 }
2052 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2053 if (adr_type->isa_instptr()) {
2054 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2055 if (field != NULL) {
2056 bt = field->layout_type();
2057 } else {
2058 // Check for unsafe oop field access
2059 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2060 bt = T_OBJECT;
2061 (*unsafe) = true;
2062 }
2063 }
2064 } else if (adr_type->isa_aryptr()) {
2065 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2066 // Ignore array length load.
2067 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2068 // Ignore first AddP.
2069 } else {
2070 const Type* elemtype = adr_type->isa_aryptr()->elem();
2071 bt = elemtype->array_element_basic_type();
2072 }
2073 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2074 // Allocation initialization, ThreadLocal field access, unsafe access
2075 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2076 bt = T_OBJECT;
2077 }
2078 }
2079 }
2080 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2081 }
2082
2083 // Returns unique pointed java object or NULL.
2084 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2085 assert(!_collecting, "should not call when contructed graph");
2086 // If the node was created after the escape computation we can't answer.
2087 uint idx = n->_idx;
2088 if (idx >= nodes_size()) {
2089 return NULL;
2090 }
2091 PointsToNode* ptn = ptnode_adr(idx);
2092 if (ptn->is_JavaObject()) {
2093 return ptn->as_JavaObject();
2094 }
2095 assert(ptn->is_LocalVar(), "sanity");
2096 // Check all java objects it points to.
2097 JavaObjectNode* jobj = NULL;
2098 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2099 PointsToNode* e = i.get();
2100 if (e->is_JavaObject()) {
2101 if (jobj == NULL) {
2102 jobj = e->as_JavaObject();
2103 } else if (jobj != e) {
2104 return NULL;
2105 }
2106 }
2107 }
2108 return jobj;
2109 }
2110
2111 // Return true if this node points only to non-escaping allocations.
2112 bool PointsToNode::non_escaping_allocation() {
2113 if (is_JavaObject()) {
2114 Node* n = ideal_node();
2115 if (n->is_Allocate() || n->is_CallStaticJava()) {
2116 return (escape_state() == PointsToNode::NoEscape);
2117 } else {
2118 return false;
2119 }
2120 }
2121 assert(is_LocalVar(), "sanity");
2122 // Check all java objects it points to.
2123 for (EdgeIterator i(this); i.has_next(); i.next()) {
2124 PointsToNode* e = i.get();
2125 if (e->is_JavaObject()) {
2126 Node* n = e->ideal_node();
2127 if ((e->escape_state() != PointsToNode::NoEscape) ||
2128 !(n->is_Allocate() || n->is_CallStaticJava())) {
2129 return false;
2130 }
2131 }
2132 }
2133 return true;
2134 }
2135
2136 // Return true if we know the node does not escape globally.
2137 bool ConnectionGraph::not_global_escape(Node *n) {
2138 assert(!_collecting, "should not call during graph construction");
2139 // If the node was created after the escape computation we can't answer.
2140 uint idx = n->_idx;
2141 if (idx >= nodes_size()) {
2142 return false;
2143 }
2144 PointsToNode* ptn = ptnode_adr(idx);
2145 PointsToNode::EscapeState es = ptn->escape_state();
2146 // If we have already computed a value, return it.
2147 if (es >= PointsToNode::GlobalEscape)
2148 return false;
2149 if (ptn->is_JavaObject()) {
2150 return true; // (es < PointsToNode::GlobalEscape);
2151 }
2152 assert(ptn->is_LocalVar(), "sanity");
2153 // Check all java objects it points to.
2154 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2155 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2156 return false;
2157 }
2158 return true;
2159 }
2160
2161
2162 // Helper functions
2163
2164 // Return true if this node points to specified node or nodes it points to.
2165 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2166 if (is_JavaObject()) {
2167 return (this == ptn);
2168 }
2169 assert(is_LocalVar() || is_Field(), "sanity");
2170 for (EdgeIterator i(this); i.has_next(); i.next()) {
2171 if (i.get() == ptn)
2172 return true;
2173 }
2174 return false;
2175 }
2176
2177 // Return true if one node points to an other.
2178 bool PointsToNode::meet(PointsToNode* ptn) {
2179 if (this == ptn) {
2180 return true;
2181 } else if (ptn->is_JavaObject()) {
2182 return this->points_to(ptn->as_JavaObject());
2183 } else if (this->is_JavaObject()) {
2184 return ptn->points_to(this->as_JavaObject());
2185 }
2186 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2187 int ptn_count = ptn->edge_count();
2188 for (EdgeIterator i(this); i.has_next(); i.next()) {
2189 PointsToNode* this_e = i.get();
2190 for (int j = 0; j < ptn_count; j++) {
2191 if (this_e == ptn->edge(j))
2192 return true;
2193 }
2194 }
2195 return false;
2196 }
2197
2198 #ifdef ASSERT
2199 // Return true if bases point to this java object.
2200 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2201 for (BaseIterator i(this); i.has_next(); i.next()) {
2202 if (i.get() == jobj)
2203 return true;
2204 }
2205 return false;
2206 }
2207 #endif
2208
2209 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2210 const Type *adr_type = phase->type(adr);
2211 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2212 adr->in(AddPNode::Address)->is_Proj() &&
2213 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2214 // We are computing a raw address for a store captured by an Initialize
2215 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2216 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2217 assert(offs != Type::OffsetBot ||
2218 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2219 "offset must be a constant or it is initialization of array");
2220 return offs;
2221 }
2222 const TypePtr *t_ptr = adr_type->isa_ptr();
2223 assert(t_ptr != NULL, "must be a pointer type");
2224 return t_ptr->offset();
2225 }
2226
2227 Node* ConnectionGraph::get_addp_base(Node *addp) {
2228 assert(addp->is_AddP(), "must be AddP");
2229 //
2230 // AddP cases for Base and Address inputs:
2231 // case #1. Direct object's field reference:
2232 // Allocate
2233 // |
2234 // Proj #5 ( oop result )
2235 // |
2236 // CheckCastPP (cast to instance type)
2237 // | |
2238 // AddP ( base == address )
2239 //
2240 // case #2. Indirect object's field reference:
2241 // Phi
2242 // |
2243 // CastPP (cast to instance type)
2244 // | |
2245 // AddP ( base == address )
2246 //
2247 // case #3. Raw object's field reference for Initialize node:
2248 // Allocate
2249 // |
2250 // Proj #5 ( oop result )
2251 // top |
2252 // \ |
2253 // AddP ( base == top )
2254 //
2255 // case #4. Array's element reference:
2256 // {CheckCastPP | CastPP}
2257 // | | |
2258 // | AddP ( array's element offset )
2259 // | |
2260 // AddP ( array's offset )
2261 //
2262 // case #5. Raw object's field reference for arraycopy stub call:
2263 // The inline_native_clone() case when the arraycopy stub is called
2264 // after the allocation before Initialize and CheckCastPP nodes.
2265 // Allocate
2266 // |
2267 // Proj #5 ( oop result )
2268 // | |
2269 // AddP ( base == address )
2270 //
2271 // case #6. Constant Pool, ThreadLocal, CastX2P or
2272 // Raw object's field reference:
2273 // {ConP, ThreadLocal, CastX2P, raw Load}
2274 // top |
2275 // \ |
2276 // AddP ( base == top )
2277 //
2278 // case #7. Klass's field reference.
2279 // LoadKlass
2280 // | |
2281 // AddP ( base == address )
2282 //
2283 // case #8. narrow Klass's field reference.
2284 // LoadNKlass
2285 // |
2286 // DecodeN
2287 // | |
2288 // AddP ( base == address )
2289 //
2290 Node *base = addp->in(AddPNode::Base);
2291 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2292 base = addp->in(AddPNode::Address);
2293 while (base->is_AddP()) {
2294 // Case #6 (unsafe access) may have several chained AddP nodes.
2295 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2296 base = base->in(AddPNode::Address);
2297 }
2298 Node* uncast_base = base->uncast();
2299 int opcode = uncast_base->Opcode();
2300 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2301 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2302 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2303 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2304 }
2305 return base;
2306 }
2307
2308 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2309 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2310 Node* addp2 = addp->raw_out(0);
2311 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2312 addp2->in(AddPNode::Base) == n &&
2313 addp2->in(AddPNode::Address) == addp) {
2314 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2315 //
2316 // Find array's offset to push it on worklist first and
2317 // as result process an array's element offset first (pushed second)
2318 // to avoid CastPP for the array's offset.
2319 // Otherwise the inserted CastPP (LocalVar) will point to what
2320 // the AddP (Field) points to. Which would be wrong since
2321 // the algorithm expects the CastPP has the same point as
2322 // as AddP's base CheckCastPP (LocalVar).
2323 //
2324 // ArrayAllocation
2325 // |
2326 // CheckCastPP
2327 // |
2328 // memProj (from ArrayAllocation CheckCastPP)
2329 // | ||
2330 // | || Int (element index)
2331 // | || | ConI (log(element size))
2332 // | || | /
2333 // | || LShift
2334 // | || /
2335 // | AddP (array's element offset)
2336 // | |
2337 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2338 // | / /
2339 // AddP (array's offset)
2340 // |
2341 // Load/Store (memory operation on array's element)
2342 //
2343 return addp2;
2344 }
2345 return NULL;
2346 }
2347
2348 //
2349 // Adjust the type and inputs of an AddP which computes the
2350 // address of a field of an instance
2351 //
2352 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2353 PhaseGVN* igvn = _igvn;
2354 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2355 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2356 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2357 if (t == NULL) {
2358 // We are computing a raw address for a store captured by an Initialize
2359 // compute an appropriate address type (cases #3 and #5).
2360 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2361 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2362 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2363 assert(offs != Type::OffsetBot, "offset must be a constant");
2364 t = base_t->add_offset(offs)->is_oopptr();
2365 }
2366 int inst_id = base_t->instance_id();
2367 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2368 "old type must be non-instance or match new type");
2369
2370 // The type 't' could be subclass of 'base_t'.
2371 // As result t->offset() could be large then base_t's size and it will
2372 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2373 // constructor verifies correctness of the offset.
2374 //
2375 // It could happened on subclass's branch (from the type profiling
2376 // inlining) which was not eliminated during parsing since the exactness
2377 // of the allocation type was not propagated to the subclass type check.
2378 //
2379 // Or the type 't' could be not related to 'base_t' at all.
2380 // It could happened when CHA type is different from MDO type on a dead path
2381 // (for example, from instanceof check) which is not collapsed during parsing.
2382 //
2383 // Do nothing for such AddP node and don't process its users since
2384 // this code branch will go away.
2385 //
2386 if (!t->is_known_instance() &&
2387 !base_t->klass()->is_subtype_of(t->klass())) {
2388 return false; // bail out
2389 }
2390 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2391 // Do NOT remove the next line: ensure a new alias index is allocated
2392 // for the instance type. Note: C++ will not remove it since the call
2393 // has side effect.
2394 int alias_idx = _compile->get_alias_index(tinst);
2395 igvn->set_type(addp, tinst);
2396 // record the allocation in the node map
2397 set_map(addp, get_map(base->_idx));
2398 // Set addp's Base and Address to 'base'.
2399 Node *abase = addp->in(AddPNode::Base);
2400 Node *adr = addp->in(AddPNode::Address);
2401 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2402 adr->in(0)->_idx == (uint)inst_id) {
2403 // Skip AddP cases #3 and #5.
2404 } else {
2405 assert(!abase->is_top(), "sanity"); // AddP case #3
2406 if (abase != base) {
2407 igvn->hash_delete(addp);
2408 addp->set_req(AddPNode::Base, base);
2409 if (abase == adr) {
2410 addp->set_req(AddPNode::Address, base);
2411 } else {
2412 // AddP case #4 (adr is array's element offset AddP node)
2413 #ifdef ASSERT
2414 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2415 assert(adr->is_AddP() && atype != NULL &&
2416 atype->instance_id() == inst_id, "array's element offset should be processed first");
2417 #endif
2418 }
2419 igvn->hash_insert(addp);
2420 }
2421 }
2422 // Put on IGVN worklist since at least addp's type was changed above.
2423 record_for_optimizer(addp);
2424 return true;
2425 }
2426
2427 //
2428 // Create a new version of orig_phi if necessary. Returns either the newly
2429 // created phi or an existing phi. Sets create_new to indicate whether a new
2430 // phi was created. Cache the last newly created phi in the node map.
2431 //
2432 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2433 Compile *C = _compile;
2434 PhaseGVN* igvn = _igvn;
2435 new_created = false;
2436 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2437 // nothing to do if orig_phi is bottom memory or matches alias_idx
2438 if (phi_alias_idx == alias_idx) {
2439 return orig_phi;
2440 }
2441 // Have we recently created a Phi for this alias index?
2442 PhiNode *result = get_map_phi(orig_phi->_idx);
2443 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2444 return result;
2445 }
2446 // Previous check may fail when the same wide memory Phi was split into Phis
2447 // for different memory slices. Search all Phis for this region.
2448 if (result != NULL) {
2449 Node* region = orig_phi->in(0);
2450 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2451 Node* phi = region->fast_out(i);
2452 if (phi->is_Phi() &&
2453 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2454 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2455 return phi->as_Phi();
2456 }
2457 }
2458 }
2459 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2460 if (C->do_escape_analysis() == true && !C->failing()) {
2461 // Retry compilation without escape analysis.
2462 // If this is the first failure, the sentinel string will "stick"
2463 // to the Compile object, and the C2Compiler will see it and retry.
2464 C->record_failure(C2Compiler::retry_no_escape_analysis());
2465 }
2466 return NULL;
2467 }
2468 orig_phi_worklist.append_if_missing(orig_phi);
2469 const TypePtr *atype = C->get_adr_type(alias_idx);
2470 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2471 C->copy_node_notes_to(result, orig_phi);
2472 igvn->set_type(result, result->bottom_type());
2473 record_for_optimizer(result);
2474 set_map(orig_phi, result);
2475 new_created = true;
2476 return result;
2477 }
2478
2479 //
2480 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2481 // specified alias index.
2482 //
2483 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2484 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2485 Compile *C = _compile;
2486 PhaseGVN* igvn = _igvn;
2487 bool new_phi_created;
2488 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2489 if (!new_phi_created) {
2490 return result;
2491 }
2492 GrowableArray<PhiNode *> phi_list;
2493 GrowableArray<uint> cur_input;
2494 PhiNode *phi = orig_phi;
2495 uint idx = 1;
2496 bool finished = false;
2497 while(!finished) {
2498 while (idx < phi->req()) {
2499 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2500 if (mem != NULL && mem->is_Phi()) {
2501 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2502 if (new_phi_created) {
2503 // found an phi for which we created a new split, push current one on worklist and begin
2504 // processing new one
2505 phi_list.push(phi);
2506 cur_input.push(idx);
2507 phi = mem->as_Phi();
2508 result = newphi;
2509 idx = 1;
2510 continue;
2511 } else {
2512 mem = newphi;
2513 }
2514 }
2515 if (C->failing()) {
2516 return NULL;
2517 }
2518 result->set_req(idx++, mem);
2519 }
2520 #ifdef ASSERT
2521 // verify that the new Phi has an input for each input of the original
2522 assert( phi->req() == result->req(), "must have same number of inputs.");
2523 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2524 #endif
2525 // Check if all new phi's inputs have specified alias index.
2526 // Otherwise use old phi.
2527 for (uint i = 1; i < phi->req(); i++) {
2528 Node* in = result->in(i);
2529 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2530 }
2531 // we have finished processing a Phi, see if there are any more to do
2532 finished = (phi_list.length() == 0 );
2533 if (!finished) {
2534 phi = phi_list.pop();
2535 idx = cur_input.pop();
2536 PhiNode *prev_result = get_map_phi(phi->_idx);
2537 prev_result->set_req(idx++, result);
2538 result = prev_result;
2539 }
2540 }
2541 return result;
2542 }
2543
2544 //
2545 // The next methods are derived from methods in MemNode.
2546 //
2547 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2548 Node *mem = mmem;
2549 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2550 // means an array I have not precisely typed yet. Do not do any
2551 // alias stuff with it any time soon.
2552 if (toop->base() != Type::AnyPtr &&
2553 !(toop->klass() != NULL &&
2554 toop->klass()->is_java_lang_Object() &&
2555 toop->offset() == Type::OffsetBot)) {
2556 mem = mmem->memory_at(alias_idx);
2557 // Update input if it is progress over what we have now
2558 }
2559 return mem;
2560 }
2561
2562 //
2563 // Move memory users to their memory slices.
2564 //
2565 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2566 Compile* C = _compile;
2567 PhaseGVN* igvn = _igvn;
2568 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2569 assert(tp != NULL, "ptr type");
2570 int alias_idx = C->get_alias_index(tp);
2571 int general_idx = C->get_general_index(alias_idx);
2572
2573 // Move users first
2574 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2575 Node* use = n->fast_out(i);
2576 if (use->is_MergeMem()) {
2577 MergeMemNode* mmem = use->as_MergeMem();
2578 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2579 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2580 continue; // Nothing to do
2581 }
2582 // Replace previous general reference to mem node.
2583 uint orig_uniq = C->unique();
2584 Node* m = find_inst_mem(n, general_idx, orig_phis);
2585 assert(orig_uniq == C->unique(), "no new nodes");
2586 mmem->set_memory_at(general_idx, m);
2587 --imax;
2588 --i;
2589 } else if (use->is_MemBar()) {
2590 assert(!use->is_Initialize(), "initializing stores should not be moved");
2591 if (use->req() > MemBarNode::Precedent &&
2592 use->in(MemBarNode::Precedent) == n) {
2593 // Don't move related membars.
2594 record_for_optimizer(use);
2595 continue;
2596 }
2597 tp = use->as_MemBar()->adr_type()->isa_ptr();
2598 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2599 alias_idx == general_idx) {
2600 continue; // Nothing to do
2601 }
2602 // Move to general memory slice.
2603 uint orig_uniq = C->unique();
2604 Node* m = find_inst_mem(n, general_idx, orig_phis);
2605 assert(orig_uniq == C->unique(), "no new nodes");
2606 igvn->hash_delete(use);
2607 imax -= use->replace_edge(n, m);
2608 igvn->hash_insert(use);
2609 record_for_optimizer(use);
2610 --i;
2611 #ifdef ASSERT
2612 } else if (use->is_Mem()) {
2613 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2614 // Don't move related cardmark.
2615 continue;
2616 }
2617 // Memory nodes should have new memory input.
2618 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2619 assert(tp != NULL, "ptr type");
2620 int idx = C->get_alias_index(tp);
2621 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2622 "Following memory nodes should have new memory input or be on the same memory slice");
2623 } else if (use->is_Phi()) {
2624 // Phi nodes should be split and moved already.
2625 tp = use->as_Phi()->adr_type()->isa_ptr();
2626 assert(tp != NULL, "ptr type");
2627 int idx = C->get_alias_index(tp);
2628 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2629 } else {
2630 use->dump();
2631 assert(false, "should not be here");
2632 #endif
2633 }
2634 }
2635 }
2636
2637 //
2638 // Search memory chain of "mem" to find a MemNode whose address
2639 // is the specified alias index.
2640 //
2641 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2642 if (orig_mem == NULL)
2643 return orig_mem;
2644 Compile* C = _compile;
2645 PhaseGVN* igvn = _igvn;
2646 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2647 bool is_instance = (toop != NULL) && toop->is_known_instance();
2648 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2649 Node *prev = NULL;
2650 Node *result = orig_mem;
2651 while (prev != result) {
2652 prev = result;
2653 if (result == start_mem)
2654 break; // hit one of our sentinels
2655 if (result->is_Mem()) {
2656 const Type *at = igvn->type(result->in(MemNode::Address));
2657 if (at == Type::TOP)
2658 break; // Dead
2659 assert (at->isa_ptr() != NULL, "pointer type required.");
2660 int idx = C->get_alias_index(at->is_ptr());
2661 if (idx == alias_idx)
2662 break; // Found
2663 if (!is_instance && (at->isa_oopptr() == NULL ||
2664 !at->is_oopptr()->is_known_instance())) {
2665 break; // Do not skip store to general memory slice.
2666 }
2667 result = result->in(MemNode::Memory);
2668 }
2669 if (!is_instance)
2670 continue; // don't search further for non-instance types
2671 // skip over a call which does not affect this memory slice
2672 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2673 Node *proj_in = result->in(0);
2674 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2675 break; // hit one of our sentinels
2676 } else if (proj_in->is_Call()) {
2677 // ArrayCopy node processed here as well
2678 CallNode *call = proj_in->as_Call();
2679 if (!call->may_modify(toop, igvn)) {
2680 result = call->in(TypeFunc::Memory);
2681 }
2682 } else if (proj_in->is_Initialize()) {
2683 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2684 // Stop if this is the initialization for the object instance which
2685 // which contains this memory slice, otherwise skip over it.
2686 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2687 result = proj_in->in(TypeFunc::Memory);
2688 }
2689 } else if (proj_in->is_MemBar()) {
2690 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2691 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2692 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2693 // clone
2694 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2695 if (ac->may_modify(toop, igvn)) {
2696 break;
2697 }
2698 }
2699 result = proj_in->in(TypeFunc::Memory);
2700 }
2701 } else if (result->is_MergeMem()) {
2702 MergeMemNode *mmem = result->as_MergeMem();
2703 result = step_through_mergemem(mmem, alias_idx, toop);
2704 if (result == mmem->base_memory()) {
2705 // Didn't find instance memory, search through general slice recursively.
2706 result = mmem->memory_at(C->get_general_index(alias_idx));
2707 result = find_inst_mem(result, alias_idx, orig_phis);
2708 if (C->failing()) {
2709 return NULL;
2710 }
2711 mmem->set_memory_at(alias_idx, result);
2712 }
2713 } else if (result->is_Phi() &&
2714 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2715 Node *un = result->as_Phi()->unique_input(igvn);
2716 if (un != NULL) {
2717 orig_phis.append_if_missing(result->as_Phi());
2718 result = un;
2719 } else {
2720 break;
2721 }
2722 } else if (result->is_ClearArray()) {
2723 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2724 // Can not bypass initialization of the instance
2725 // we are looking for.
2726 break;
2727 }
2728 // Otherwise skip it (the call updated 'result' value).
2729 } else if (result->Opcode() == Op_SCMemProj) {
2730 Node* mem = result->in(0);
2731 Node* adr = NULL;
2732 if (mem->is_LoadStore()) {
2733 adr = mem->in(MemNode::Address);
2734 } else {
2735 assert(mem->Opcode() == Op_EncodeISOArray ||
2736 mem->Opcode() == Op_StrInflatedCopy ||
2737 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2738 adr = mem->in(3); // Memory edge corresponds to destination array
2739 }
2740 const Type *at = igvn->type(adr);
2741 if (at != Type::TOP) {
2742 assert(at->isa_ptr() != NULL, "pointer type required.");
2743 int idx = C->get_alias_index(at->is_ptr());
2744 if (idx == alias_idx) {
2745 // Assert in debug mode
2746 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2747 break; // In product mode return SCMemProj node
2748 }
2749 }
2750 result = mem->in(MemNode::Memory);
2751 }
2752 }
2753 if (result->is_Phi()) {
2754 PhiNode *mphi = result->as_Phi();
2755 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2756 const TypePtr *t = mphi->adr_type();
2757 if (!is_instance) {
2758 // Push all non-instance Phis on the orig_phis worklist to update inputs
2759 // during Phase 4 if needed.
2760 orig_phis.append_if_missing(mphi);
2761 } else if (C->get_alias_index(t) != alias_idx) {
2762 // Create a new Phi with the specified alias index type.
2763 result = split_memory_phi(mphi, alias_idx, orig_phis);
2764 }
2765 }
2766 // the result is either MemNode, PhiNode, InitializeNode.
2767 return result;
2768 }
2769
2770 //
2771 // Convert the types of unescaped object to instance types where possible,
2772 // propagate the new type information through the graph, and update memory
2773 // edges and MergeMem inputs to reflect the new type.
2774 //
2775 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2776 // The processing is done in 4 phases:
2777 //
2778 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2779 // types for the CheckCastPP for allocations where possible.
2780 // Propagate the new types through users as follows:
2781 // casts and Phi: push users on alloc_worklist
2782 // AddP: cast Base and Address inputs to the instance type
2783 // push any AddP users on alloc_worklist and push any memnode
2784 // users onto memnode_worklist.
2785 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2786 // search the Memory chain for a store with the appropriate type
2787 // address type. If a Phi is found, create a new version with
2788 // the appropriate memory slices from each of the Phi inputs.
2789 // For stores, process the users as follows:
2790 // MemNode: push on memnode_worklist
2791 // MergeMem: push on mergemem_worklist
2792 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2793 // moving the first node encountered of each instance type to the
2794 // the input corresponding to its alias index.
2795 // appropriate memory slice.
2796 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2797 //
2798 // In the following example, the CheckCastPP nodes are the cast of allocation
2799 // results and the allocation of node 29 is unescaped and eligible to be an
2800 // instance type.
2801 //
2802 // We start with:
2803 //
2804 // 7 Parm #memory
2805 // 10 ConI "12"
2806 // 19 CheckCastPP "Foo"
2807 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2808 // 29 CheckCastPP "Foo"
2809 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2810 //
2811 // 40 StoreP 25 7 20 ... alias_index=4
2812 // 50 StoreP 35 40 30 ... alias_index=4
2813 // 60 StoreP 45 50 20 ... alias_index=4
2814 // 70 LoadP _ 60 30 ... alias_index=4
2815 // 80 Phi 75 50 60 Memory alias_index=4
2816 // 90 LoadP _ 80 30 ... alias_index=4
2817 // 100 LoadP _ 80 20 ... alias_index=4
2818 //
2819 //
2820 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2821 // and creating a new alias index for node 30. This gives:
2822 //
2823 // 7 Parm #memory
2824 // 10 ConI "12"
2825 // 19 CheckCastPP "Foo"
2826 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2827 // 29 CheckCastPP "Foo" iid=24
2828 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2829 //
2830 // 40 StoreP 25 7 20 ... alias_index=4
2831 // 50 StoreP 35 40 30 ... alias_index=6
2832 // 60 StoreP 45 50 20 ... alias_index=4
2833 // 70 LoadP _ 60 30 ... alias_index=6
2834 // 80 Phi 75 50 60 Memory alias_index=4
2835 // 90 LoadP _ 80 30 ... alias_index=6
2836 // 100 LoadP _ 80 20 ... alias_index=4
2837 //
2838 // In phase 2, new memory inputs are computed for the loads and stores,
2839 // And a new version of the phi is created. In phase 4, the inputs to
2840 // node 80 are updated and then the memory nodes are updated with the
2841 // values computed in phase 2. This results in:
2842 //
2843 // 7 Parm #memory
2844 // 10 ConI "12"
2845 // 19 CheckCastPP "Foo"
2846 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2847 // 29 CheckCastPP "Foo" iid=24
2848 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2849 //
2850 // 40 StoreP 25 7 20 ... alias_index=4
2851 // 50 StoreP 35 7 30 ... alias_index=6
2852 // 60 StoreP 45 40 20 ... alias_index=4
2853 // 70 LoadP _ 50 30 ... alias_index=6
2854 // 80 Phi 75 40 60 Memory alias_index=4
2855 // 120 Phi 75 50 50 Memory alias_index=6
2856 // 90 LoadP _ 120 30 ... alias_index=6
2857 // 100 LoadP _ 80 20 ... alias_index=4
2858 //
2859 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2860 GrowableArray<Node *> memnode_worklist;
2861 GrowableArray<PhiNode *> orig_phis;
2862 PhaseIterGVN *igvn = _igvn;
2863 uint new_index_start = (uint) _compile->num_alias_types();
2864 Arena* arena = Thread::current()->resource_area();
2865 VectorSet visited(arena);
2866 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2867 uint unique_old = _compile->unique();
2868
2869 // Phase 1: Process possible allocations from alloc_worklist.
2870 // Create instance types for the CheckCastPP for allocations where possible.
2871 //
2872 // (Note: don't forget to change the order of the second AddP node on
2873 // the alloc_worklist if the order of the worklist processing is changed,
2874 // see the comment in find_second_addp().)
2875 //
2876 while (alloc_worklist.length() != 0) {
2877 Node *n = alloc_worklist.pop();
2878 uint ni = n->_idx;
2879 if (n->is_Call()) {
2880 CallNode *alloc = n->as_Call();
2881 // copy escape information to call node
2882 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2883 PointsToNode::EscapeState es = ptn->escape_state();
2884 // We have an allocation or call which returns a Java object,
2885 // see if it is unescaped.
2886 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2887 continue;
2888 // Find CheckCastPP for the allocate or for the return value of a call
2889 n = alloc->result_cast();
2890 if (n == NULL) { // No uses except Initialize node
2891 if (alloc->is_Allocate()) {
2892 // Set the scalar_replaceable flag for allocation
2893 // so it could be eliminated if it has no uses.
2894 alloc->as_Allocate()->_is_scalar_replaceable = true;
2895 }
2896 if (alloc->is_CallStaticJava()) {
2897 // Set the scalar_replaceable flag for boxing method
2898 // so it could be eliminated if it has no uses.
2899 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2900 }
2901 continue;
2902 }
2903 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2904 assert(!alloc->is_Allocate(), "allocation should have unique type");
2905 continue;
2906 }
2907
2908 // The inline code for Object.clone() casts the allocation result to
2909 // java.lang.Object and then to the actual type of the allocated
2910 // object. Detect this case and use the second cast.
2911 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2912 // the allocation result is cast to java.lang.Object and then
2913 // to the actual Array type.
2914 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2915 && (alloc->is_AllocateArray() ||
2916 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2917 Node *cast2 = NULL;
2918 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2919 Node *use = n->fast_out(i);
2920 if (use->is_CheckCastPP()) {
2921 cast2 = use;
2922 break;
2923 }
2924 }
2925 if (cast2 != NULL) {
2926 n = cast2;
2927 } else {
2928 // Non-scalar replaceable if the allocation type is unknown statically
2929 // (reflection allocation), the object can't be restored during
2930 // deoptimization without precise type.
2931 continue;
2932 }
2933 }
2934
2935 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2936 if (t == NULL)
2937 continue; // not a TypeOopPtr
2938 if (!t->klass_is_exact())
2939 continue; // not an unique type
2940
2941 if (alloc->is_Allocate()) {
2942 // Set the scalar_replaceable flag for allocation
2943 // so it could be eliminated.
2944 alloc->as_Allocate()->_is_scalar_replaceable = true;
2945 }
2946 if (alloc->is_CallStaticJava()) {
2947 // Set the scalar_replaceable flag for boxing method
2948 // so it could be eliminated.
2949 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2950 }
2951 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2952 // in order for an object to be scalar-replaceable, it must be:
2953 // - a direct allocation (not a call returning an object)
2954 // - non-escaping
2955 // - eligible to be a unique type
2956 // - not determined to be ineligible by escape analysis
2957 set_map(alloc, n);
2958 set_map(n, alloc);
2959 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2960 igvn->hash_delete(n);
2961 igvn->set_type(n, tinst);
2962 n->raise_bottom_type(tinst);
2963 igvn->hash_insert(n);
2964 record_for_optimizer(n);
2965 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2966
2967 // First, put on the worklist all Field edges from Connection Graph
2968 // which is more accurate than putting immediate users from Ideal Graph.
2969 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2970 PointsToNode* tgt = e.get();
2971 if (tgt->is_Arraycopy()) {
2972 continue;
2973 }
2974 Node* use = tgt->ideal_node();
2975 assert(tgt->is_Field() && use->is_AddP(),
2976 "only AddP nodes are Field edges in CG");
2977 if (use->outcnt() > 0) { // Don't process dead nodes
2978 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2979 if (addp2 != NULL) {
2980 assert(alloc->is_AllocateArray(),"array allocation was expected");
2981 alloc_worklist.append_if_missing(addp2);
2982 }
2983 alloc_worklist.append_if_missing(use);
2984 }
2985 }
2986
2987 // An allocation may have an Initialize which has raw stores. Scan
2988 // the users of the raw allocation result and push AddP users
2989 // on alloc_worklist.
2990 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2991 assert (raw_result != NULL, "must have an allocation result");
2992 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2993 Node *use = raw_result->fast_out(i);
2994 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2995 Node* addp2 = find_second_addp(use, raw_result);
2996 if (addp2 != NULL) {
2997 assert(alloc->is_AllocateArray(),"array allocation was expected");
2998 alloc_worklist.append_if_missing(addp2);
2999 }
3000 alloc_worklist.append_if_missing(use);
3001 } else if (use->is_MemBar()) {
3002 memnode_worklist.append_if_missing(use);
3003 }
3004 }
3005 }
3006 } else if (n->is_AddP()) {
3007 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3008 if (jobj == NULL || jobj == phantom_obj) {
3009 #ifdef ASSERT
3010 ptnode_adr(get_addp_base(n)->_idx)->dump();
3011 ptnode_adr(n->_idx)->dump();
3012 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3013 #endif
3014 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3015 return;
3016 }
3017 Node *base = get_map(jobj->idx()); // CheckCastPP node
3018 if (!split_AddP(n, base)) continue; // wrong type from dead path
3019 } else if (n->is_Phi() ||
3020 n->is_CheckCastPP() ||
3021 n->is_EncodeP() ||
3022 n->is_DecodeN() ||
3023 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3024 if (visited.test_set(n->_idx)) {
3025 assert(n->is_Phi(), "loops only through Phi's");
3026 continue; // already processed
3027 }
3028 JavaObjectNode* jobj = unique_java_object(n);
3029 if (jobj == NULL || jobj == phantom_obj) {
3030 #ifdef ASSERT
3031 ptnode_adr(n->_idx)->dump();
3032 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3033 #endif
3034 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3035 return;
3036 } else {
3037 Node *val = get_map(jobj->idx()); // CheckCastPP node
3038 TypeNode *tn = n->as_Type();
3039 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3040 assert(tinst != NULL && tinst->is_known_instance() &&
3041 tinst->instance_id() == jobj->idx() , "instance type expected.");
3042
3043 const Type *tn_type = igvn->type(tn);
3044 const TypeOopPtr *tn_t;
3045 if (tn_type->isa_narrowoop()) {
3046 tn_t = tn_type->make_ptr()->isa_oopptr();
3047 } else {
3048 tn_t = tn_type->isa_oopptr();
3049 }
3050 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3051 if (tn_type->isa_narrowoop()) {
3052 tn_type = tinst->make_narrowoop();
3053 } else {
3054 tn_type = tinst;
3055 }
3056 igvn->hash_delete(tn);
3057 igvn->set_type(tn, tn_type);
3058 tn->set_type(tn_type);
3059 igvn->hash_insert(tn);
3060 record_for_optimizer(n);
3061 } else {
3062 assert(tn_type == TypePtr::NULL_PTR ||
3063 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3064 "unexpected type");
3065 continue; // Skip dead path with different type
3066 }
3067 }
3068 } else {
3069 debug_only(n->dump();)
3070 assert(false, "EA: unexpected node");
3071 continue;
3072 }
3073 // push allocation's users on appropriate worklist
3074 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3075 Node *use = n->fast_out(i);
3076 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3077 // Load/store to instance's field
3078 memnode_worklist.append_if_missing(use);
3079 } else if (use->is_MemBar()) {
3080 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3081 memnode_worklist.append_if_missing(use);
3082 }
3083 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3084 Node* addp2 = find_second_addp(use, n);
3085 if (addp2 != NULL) {
3086 alloc_worklist.append_if_missing(addp2);
3087 }
3088 alloc_worklist.append_if_missing(use);
3089 } else if (use->is_Phi() ||
3090 use->is_CheckCastPP() ||
3091 use->is_EncodeNarrowPtr() ||
3092 use->is_DecodeNarrowPtr() ||
3093 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3094 alloc_worklist.append_if_missing(use);
3095 #ifdef ASSERT
3096 } else if (use->is_Mem()) {
3097 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3098 } else if (use->is_MergeMem()) {
3099 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3100 } else if (use->is_SafePoint()) {
3101 // Look for MergeMem nodes for calls which reference unique allocation
3102 // (through CheckCastPP nodes) even for debug info.
3103 Node* m = use->in(TypeFunc::Memory);
3104 if (m->is_MergeMem()) {
3105 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3106 }
3107 } else if (use->Opcode() == Op_EncodeISOArray) {
3108 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3109 // EncodeISOArray overwrites destination array
3110 memnode_worklist.append_if_missing(use);
3111 }
3112 } else {
3113 uint op = use->Opcode();
3114 if ((use->in(MemNode::Memory) == n) &&
3115 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3116 // They overwrite memory edge corresponding to destination array,
3117 memnode_worklist.append_if_missing(use);
3118 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3119 op == Op_CastP2X || op == Op_StoreCM ||
3120 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3121 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3122 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3123 n->dump();
3124 use->dump();
3125 assert(false, "EA: missing allocation reference path");
3126 }
3127 #endif
3128 }
3129 }
3130
3131 }
3132
3133 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3134 // type, record it in the ArrayCopy node so we know what memory this
3135 // node uses/modified.
3136 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3137 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3138 Node* dest = ac->in(ArrayCopyNode::Dest);
3139 if (dest->is_AddP()) {
3140 dest = get_addp_base(dest);
3141 }
3142 JavaObjectNode* jobj = unique_java_object(dest);
3143 if (jobj != NULL) {
3144 Node *base = get_map(jobj->idx());
3145 if (base != NULL) {
3146 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3147 ac->_dest_type = base_t;
3148 }
3149 }
3150 Node* src = ac->in(ArrayCopyNode::Src);
3151 if (src->is_AddP()) {
3152 src = get_addp_base(src);
3153 }
3154 jobj = unique_java_object(src);
3155 if (jobj != NULL) {
3156 Node* base = get_map(jobj->idx());
3157 if (base != NULL) {
3158 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3159 ac->_src_type = base_t;
3160 }
3161 }
3162 }
3163
3164 // New alias types were created in split_AddP().
3165 uint new_index_end = (uint) _compile->num_alias_types();
3166 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3167
3168 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3169 // compute new values for Memory inputs (the Memory inputs are not
3170 // actually updated until phase 4.)
3171 if (memnode_worklist.length() == 0)
3172 return; // nothing to do
3173 while (memnode_worklist.length() != 0) {
3174 Node *n = memnode_worklist.pop();
3175 if (visited.test_set(n->_idx))
3176 continue;
3177 if (n->is_Phi() || n->is_ClearArray()) {
3178 // we don't need to do anything, but the users must be pushed
3179 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3180 // we don't need to do anything, but the users must be pushed
3181 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3182 if (n == NULL)
3183 continue;
3184 } else if (n->Opcode() == Op_StrCompressedCopy ||
3185 n->Opcode() == Op_StrInflatedCopy ||
3186 n->Opcode() == Op_EncodeISOArray) {
3187 // get the memory projection
3188 n = n->find_out_with(Op_SCMemProj);
3189 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3190 } else {
3191 assert(n->is_Mem(), "memory node required.");
3192 Node *addr = n->in(MemNode::Address);
3193 const Type *addr_t = igvn->type(addr);
3194 if (addr_t == Type::TOP)
3195 continue;
3196 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3197 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3198 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3199 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3200 if (_compile->failing()) {
3201 return;
3202 }
3203 if (mem != n->in(MemNode::Memory)) {
3204 // We delay the memory edge update since we need old one in
3205 // MergeMem code below when instances memory slices are separated.
3206 set_map(n, mem);
3207 }
3208 if (n->is_Load()) {
3209 continue; // don't push users
3210 } else if (n->is_LoadStore()) {
3211 // get the memory projection
3212 n = n->find_out_with(Op_SCMemProj);
3213 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3214 }
3215 }
3216 // push user on appropriate worklist
3217 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3218 Node *use = n->fast_out(i);
3219 if (use->is_Phi() || use->is_ClearArray()) {
3220 memnode_worklist.append_if_missing(use);
3221 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3222 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3223 continue;
3224 memnode_worklist.append_if_missing(use);
3225 } else if (use->is_MemBar()) {
3226 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3227 memnode_worklist.append_if_missing(use);
3228 }
3229 #ifdef ASSERT
3230 } else if(use->is_Mem()) {
3231 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3232 } else if (use->is_MergeMem()) {
3233 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3234 } else if (use->Opcode() == Op_EncodeISOArray) {
3235 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3236 // EncodeISOArray overwrites destination array
3237 memnode_worklist.append_if_missing(use);
3238 }
3239 } else {
3240 uint op = use->Opcode();
3241 if ((use->in(MemNode::Memory) == n) &&
3242 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3243 // They overwrite memory edge corresponding to destination array,
3244 memnode_worklist.append_if_missing(use);
3245 } else if (!(op == Op_StoreCM ||
3246 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3247 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3248 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3249 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3250 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3251 n->dump();
3252 use->dump();
3253 assert(false, "EA: missing memory path");
3254 }
3255 #endif
3256 }
3257 }
3258 }
3259
3260 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3261 // Walk each memory slice moving the first node encountered of each
3262 // instance type to the the input corresponding to its alias index.
3263 uint length = _mergemem_worklist.length();
3264 for( uint next = 0; next < length; ++next ) {
3265 MergeMemNode* nmm = _mergemem_worklist.at(next);
3266 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3267 // Note: we don't want to use MergeMemStream here because we only want to
3268 // scan inputs which exist at the start, not ones we add during processing.
3269 // Note 2: MergeMem may already contains instance memory slices added
3270 // during find_inst_mem() call when memory nodes were processed above.
3271 igvn->hash_delete(nmm);
3272 uint nslices = MIN2(nmm->req(), new_index_start);
3273 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3274 Node* mem = nmm->in(i);
3275 Node* cur = NULL;
3276 if (mem == NULL || mem->is_top())
3277 continue;
3278 // First, update mergemem by moving memory nodes to corresponding slices
3279 // if their type became more precise since this mergemem was created.
3280 while (mem->is_Mem()) {
3281 const Type *at = igvn->type(mem->in(MemNode::Address));
3282 if (at != Type::TOP) {
3283 assert (at->isa_ptr() != NULL, "pointer type required.");
3284 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3285 if (idx == i) {
3286 if (cur == NULL)
3287 cur = mem;
3288 } else {
3289 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3290 nmm->set_memory_at(idx, mem);
3291 }
3292 }
3293 }
3294 mem = mem->in(MemNode::Memory);
3295 }
3296 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3297 // Find any instance of the current type if we haven't encountered
3298 // already a memory slice of the instance along the memory chain.
3299 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3300 if((uint)_compile->get_general_index(ni) == i) {
3301 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3302 if (nmm->is_empty_memory(m)) {
3303 Node* result = find_inst_mem(mem, ni, orig_phis);
3304 if (_compile->failing()) {
3305 return;
3306 }
3307 nmm->set_memory_at(ni, result);
3308 }
3309 }
3310 }
3311 }
3312 // Find the rest of instances values
3313 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3314 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3315 Node* result = step_through_mergemem(nmm, ni, tinst);
3316 if (result == nmm->base_memory()) {
3317 // Didn't find instance memory, search through general slice recursively.
3318 result = nmm->memory_at(_compile->get_general_index(ni));
3319 result = find_inst_mem(result, ni, orig_phis);
3320 if (_compile->failing()) {
3321 return;
3322 }
3323 nmm->set_memory_at(ni, result);
3324 }
3325 }
3326 igvn->hash_insert(nmm);
3327 record_for_optimizer(nmm);
3328 }
3329
3330 // Phase 4: Update the inputs of non-instance memory Phis and
3331 // the Memory input of memnodes
3332 // First update the inputs of any non-instance Phi's from
3333 // which we split out an instance Phi. Note we don't have
3334 // to recursively process Phi's encounted on the input memory
3335 // chains as is done in split_memory_phi() since they will
3336 // also be processed here.
3337 for (int j = 0; j < orig_phis.length(); j++) {
3338 PhiNode *phi = orig_phis.at(j);
3339 int alias_idx = _compile->get_alias_index(phi->adr_type());
3340 igvn->hash_delete(phi);
3341 for (uint i = 1; i < phi->req(); i++) {
3342 Node *mem = phi->in(i);
3343 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3344 if (_compile->failing()) {
3345 return;
3346 }
3347 if (mem != new_mem) {
3348 phi->set_req(i, new_mem);
3349 }
3350 }
3351 igvn->hash_insert(phi);
3352 record_for_optimizer(phi);
3353 }
3354
3355 // Update the memory inputs of MemNodes with the value we computed
3356 // in Phase 2 and move stores memory users to corresponding memory slices.
3357 // Disable memory split verification code until the fix for 6984348.
3358 // Currently it produces false negative results since it does not cover all cases.
3359 #if 0 // ifdef ASSERT
3360 visited.Reset();
3361 Node_Stack old_mems(arena, _compile->unique() >> 2);
3362 #endif
3363 for (uint i = 0; i < ideal_nodes.size(); i++) {
3364 Node* n = ideal_nodes.at(i);
3365 Node* nmem = get_map(n->_idx);
3366 assert(nmem != NULL, "sanity");
3367 if (n->is_Mem()) {
3368 #if 0 // ifdef ASSERT
3369 Node* old_mem = n->in(MemNode::Memory);
3370 if (!visited.test_set(old_mem->_idx)) {
3371 old_mems.push(old_mem, old_mem->outcnt());
3372 }
3373 #endif
3374 assert(n->in(MemNode::Memory) != nmem, "sanity");
3375 if (!n->is_Load()) {
3376 // Move memory users of a store first.
3377 move_inst_mem(n, orig_phis);
3378 }
3379 // Now update memory input
3380 igvn->hash_delete(n);
3381 n->set_req(MemNode::Memory, nmem);
3382 igvn->hash_insert(n);
3383 record_for_optimizer(n);
3384 } else {
3385 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3386 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3387 }
3388 }
3389 #if 0 // ifdef ASSERT
3390 // Verify that memory was split correctly
3391 while (old_mems.is_nonempty()) {
3392 Node* old_mem = old_mems.node();
3393 uint old_cnt = old_mems.index();
3394 old_mems.pop();
3395 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3396 }
3397 #endif
3398 }
3399
3400 #ifndef PRODUCT
3401 static const char *node_type_names[] = {
3402 "UnknownType",
3403 "JavaObject",
3404 "LocalVar",
3405 "Field",
3406 "Arraycopy"
3407 };
3408
3409 static const char *esc_names[] = {
3410 "UnknownEscape",
3411 "NoEscape",
3412 "ArgEscape",
3413 "GlobalEscape"
3414 };
3415
3416 void PointsToNode::dump(bool print_state) const {
3417 NodeType nt = node_type();
3418 tty->print("%s ", node_type_names[(int) nt]);
3419 if (print_state) {
3420 EscapeState es = escape_state();
3421 EscapeState fields_es = fields_escape_state();
3422 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3423 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3424 tty->print("NSR ");
3425 }
3426 if (is_Field()) {
3427 FieldNode* f = (FieldNode*)this;
3428 if (f->is_oop())
3429 tty->print("oop ");
3430 if (f->offset() > 0)
3431 tty->print("+%d ", f->offset());
3432 tty->print("(");
3433 for (BaseIterator i(f); i.has_next(); i.next()) {
3434 PointsToNode* b = i.get();
3435 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3436 }
3437 tty->print(" )");
3438 }
3439 tty->print("[");
3440 for (EdgeIterator i(this); i.has_next(); i.next()) {
3441 PointsToNode* e = i.get();
3442 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3443 }
3444 tty->print(" [");
3445 for (UseIterator i(this); i.has_next(); i.next()) {
3446 PointsToNode* u = i.get();
3447 bool is_base = false;
3448 if (PointsToNode::is_base_use(u)) {
3449 is_base = true;
3450 u = PointsToNode::get_use_node(u)->as_Field();
3451 }
3452 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3453 }
3454 tty->print(" ]] ");
3455 if (_node == NULL)
3456 tty->print_cr("<null>");
3457 else
3458 _node->dump();
3459 }
3460
3461 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3462 bool first = true;
3463 int ptnodes_length = ptnodes_worklist.length();
3464 for (int i = 0; i < ptnodes_length; i++) {
3465 PointsToNode *ptn = ptnodes_worklist.at(i);
3466 if (ptn == NULL || !ptn->is_JavaObject())
3467 continue;
3468 PointsToNode::EscapeState es = ptn->escape_state();
3469 if ((es != PointsToNode::NoEscape) && !Verbose) {
3470 continue;
3471 }
3472 Node* n = ptn->ideal_node();
3473 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3474 n->as_CallStaticJava()->is_boxing_method())) {
3475 if (first) {
3476 tty->cr();
3477 tty->print("======== Connection graph for ");
3478 _compile->method()->print_short_name();
3479 tty->cr();
3480 first = false;
3481 }
3482 ptn->dump();
3483 // Print all locals and fields which reference this allocation
3484 for (UseIterator j(ptn); j.has_next(); j.next()) {
3485 PointsToNode* use = j.get();
3486 if (use->is_LocalVar()) {
3487 use->dump(Verbose);
3488 } else if (Verbose) {
3489 use->dump();
3490 }
3491 }
3492 tty->cr();
3493 }
3494 }
3495 }
3496 #endif