1 /*
2 * Copyright (c) 2005, 2018, 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 "gc/shared/c2/barrierSetC2.hpp"
29 #include "libadt/vectset.hpp"
30 #include "memory/allocation.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "opto/c2compiler.hpp"
33 #include "opto/arraycopynode.hpp"
34 #include "opto/callnode.hpp"
35 #include "opto/cfgnode.hpp"
36 #include "opto/compile.hpp"
37 #include "opto/escape.hpp"
38 #include "opto/phaseX.hpp"
39 #include "opto/movenode.hpp"
40 #include "opto/rootnode.hpp"
41 #if INCLUDE_G1GC
42 #include "gc/g1/g1ThreadLocalData.hpp"
43 #endif // INCLUDE_G1GC
44
45 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
46 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
47 _in_worklist(C->comp_arena()),
48 _next_pidx(0),
49 _collecting(true),
50 _verify(false),
51 _compile(C),
52 _igvn(igvn),
53 _node_map(C->comp_arena()) {
54 // Add unknown java object.
55 add_java_object(C->top(), PointsToNode::GlobalEscape);
56 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
57 // Add ConP(#NULL) and ConN(#NULL) nodes.
58 Node* oop_null = igvn->zerocon(T_OBJECT);
59 assert(oop_null->_idx < nodes_size(), "should be created already");
60 add_java_object(oop_null, PointsToNode::NoEscape);
61 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
62 if (UseCompressedOops) {
63 Node* noop_null = igvn->zerocon(T_NARROWOOP);
64 assert(noop_null->_idx < nodes_size(), "should be created already");
65 map_ideal_node(noop_null, null_obj);
66 }
67 _pcmp_neq = NULL; // Should be initialized
68 _pcmp_eq = NULL;
69 }
70
71 bool ConnectionGraph::has_candidates(Compile *C) {
72 // EA brings benefits only when the code has allocations and/or locks which
73 // are represented by ideal Macro nodes.
74 int cnt = C->macro_count();
75 for (int i = 0; i < cnt; i++) {
76 Node *n = C->macro_node(i);
77 if (n->is_Allocate())
78 return true;
79 if (n->is_Lock()) {
80 Node* obj = n->as_Lock()->obj_node()->uncast();
81 if (!(obj->is_Parm() || obj->is_Con()))
82 return true;
83 }
84 if (n->is_CallStaticJava() &&
85 n->as_CallStaticJava()->is_boxing_method()) {
86 return true;
87 }
88 }
89 return false;
90 }
91
92 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
93 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
94 ResourceMark rm;
95
96 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
97 // to create space for them in ConnectionGraph::_nodes[].
98 Node* oop_null = igvn->zerocon(T_OBJECT);
99 Node* noop_null = igvn->zerocon(T_NARROWOOP);
100 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
101 // Perform escape analysis
102 if (congraph->compute_escape()) {
103 // There are non escaping objects.
104 C->set_congraph(congraph);
105 }
106 // Cleanup.
107 if (oop_null->outcnt() == 0)
108 igvn->hash_delete(oop_null);
109 if (noop_null->outcnt() == 0)
110 igvn->hash_delete(noop_null);
111 }
112
113 bool ConnectionGraph::compute_escape() {
114 Compile* C = _compile;
115 PhaseGVN* igvn = _igvn;
116
117 // Worklists used by EA.
118 Unique_Node_List delayed_worklist;
119 GrowableArray<Node*> alloc_worklist;
120 GrowableArray<Node*> ptr_cmp_worklist;
121 GrowableArray<Node*> storestore_worklist;
122 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
123 GrowableArray<PointsToNode*> ptnodes_worklist;
124 GrowableArray<JavaObjectNode*> java_objects_worklist;
125 GrowableArray<JavaObjectNode*> non_escaped_worklist;
126 GrowableArray<FieldNode*> oop_fields_worklist;
127 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
128
129 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
130
131 // 1. Populate Connection Graph (CG) with PointsTo nodes.
132 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
133 // Initialize worklist
134 if (C->root() != NULL) {
135 ideal_nodes.push(C->root());
136 }
137 // Processed ideal nodes are unique on ideal_nodes list
138 // but several ideal nodes are mapped to the phantom_obj.
139 // To avoid duplicated entries on the following worklists
140 // add the phantom_obj only once to them.
141 ptnodes_worklist.append(phantom_obj);
142 java_objects_worklist.append(phantom_obj);
143 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
144 Node* n = ideal_nodes.at(next);
145 // Create PointsTo nodes and add them to Connection Graph. Called
146 // only once per ideal node since ideal_nodes is Unique_Node list.
147 add_node_to_connection_graph(n, &delayed_worklist);
148 PointsToNode* ptn = ptnode_adr(n->_idx);
149 if (ptn != NULL && ptn != phantom_obj) {
150 ptnodes_worklist.append(ptn);
151 if (ptn->is_JavaObject()) {
152 java_objects_worklist.append(ptn->as_JavaObject());
153 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
154 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
155 // Only allocations and java static calls results are interesting.
156 non_escaped_worklist.append(ptn->as_JavaObject());
157 }
158 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
159 oop_fields_worklist.append(ptn->as_Field());
160 }
161 }
162 if (n->is_MergeMem()) {
163 // Collect all MergeMem nodes to add memory slices for
164 // scalar replaceable objects in split_unique_types().
165 _mergemem_worklist.append(n->as_MergeMem());
166 } else if (OptimizePtrCompare && n->is_Cmp() &&
167 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
168 // Collect compare pointers nodes.
169 ptr_cmp_worklist.append(n);
170 } else if (n->is_MemBarStoreStore()) {
171 // Collect all MemBarStoreStore nodes so that depending on the
172 // escape status of the associated Allocate node some of them
173 // may be eliminated.
174 storestore_worklist.append(n);
175 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
176 (n->req() > MemBarNode::Precedent)) {
177 record_for_optimizer(n);
178 #ifdef ASSERT
179 } else if (n->is_AddP()) {
180 // Collect address nodes for graph verification.
181 addp_worklist.append(n);
182 #endif
183 } else if (n->is_ArrayCopy()) {
184 // Keep a list of ArrayCopy nodes so if one of its input is non
185 // escaping, we can record a unique type
186 arraycopy_worklist.append(n->as_ArrayCopy());
187 }
188 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
189 Node* m = n->fast_out(i); // Get user
190 ideal_nodes.push(m);
191 }
192 }
193 if (non_escaped_worklist.length() == 0) {
194 _collecting = false;
195 return false; // Nothing to do.
196 }
197 // Add final simple edges to graph.
198 while(delayed_worklist.size() > 0) {
199 Node* n = delayed_worklist.pop();
200 add_final_edges(n);
201 }
202 int ptnodes_length = ptnodes_worklist.length();
203
204 #ifdef ASSERT
205 if (VerifyConnectionGraph) {
206 // Verify that no new simple edges could be created and all
207 // local vars has edges.
208 _verify = true;
209 for (int next = 0; next < ptnodes_length; ++next) {
210 PointsToNode* ptn = ptnodes_worklist.at(next);
211 add_final_edges(ptn->ideal_node());
212 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
213 ptn->dump();
214 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
215 }
216 }
217 _verify = false;
218 }
219 #endif
220 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
221 // processing, calls to CI to resolve symbols (types, fields, methods)
222 // referenced in bytecode. During symbol resolution VM may throw
223 // an exception which CI cleans and converts to compilation failure.
224 if (C->failing()) return false;
225
226 // 2. Finish Graph construction by propagating references to all
227 // java objects through graph.
228 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
229 java_objects_worklist, oop_fields_worklist)) {
230 // All objects escaped or hit time or iterations limits.
231 _collecting = false;
232 return false;
233 }
234
235 // 3. Adjust scalar_replaceable state of nonescaping objects and push
236 // scalar replaceable allocations on alloc_worklist for processing
237 // in split_unique_types().
238 int non_escaped_length = non_escaped_worklist.length();
239 for (int next = 0; next < non_escaped_length; next++) {
240 JavaObjectNode* ptn = non_escaped_worklist.at(next);
241 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
242 Node* n = ptn->ideal_node();
243 if (n->is_Allocate()) {
244 n->as_Allocate()->_is_non_escaping = noescape;
245 }
246 if (n->is_CallStaticJava()) {
247 n->as_CallStaticJava()->_is_non_escaping = noescape;
248 }
249 if (noescape && ptn->scalar_replaceable()) {
250 adjust_scalar_replaceable_state(ptn);
251 if (ptn->scalar_replaceable()) {
252 alloc_worklist.append(ptn->ideal_node());
253 }
254 }
255 }
256
257 #ifdef ASSERT
258 if (VerifyConnectionGraph) {
259 // Verify that graph is complete - no new edges could be added or needed.
260 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
261 java_objects_worklist, addp_worklist);
262 }
263 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
264 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
265 null_obj->edge_count() == 0 &&
266 !null_obj->arraycopy_src() &&
267 !null_obj->arraycopy_dst(), "sanity");
268 #endif
269
270 _collecting = false;
271
272 } // TracePhase t3("connectionGraph")
273
274 // 4. Optimize ideal graph based on EA information.
275 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
276 if (has_non_escaping_obj) {
277 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
278 }
279
280 #ifndef PRODUCT
281 if (PrintEscapeAnalysis) {
282 dump(ptnodes_worklist); // Dump ConnectionGraph
283 }
284 #endif
285
286 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
287 #ifdef ASSERT
288 if (VerifyConnectionGraph) {
289 int alloc_length = alloc_worklist.length();
290 for (int next = 0; next < alloc_length; ++next) {
291 Node* n = alloc_worklist.at(next);
292 PointsToNode* ptn = ptnode_adr(n->_idx);
293 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
294 }
295 }
296 #endif
297
298 // 5. Separate memory graph for scalar replaceable allcations.
299 if (has_scalar_replaceable_candidates &&
300 C->AliasLevel() >= 3 && EliminateAllocations) {
301 // Now use the escape information to create unique types for
302 // scalar replaceable objects.
303 split_unique_types(alloc_worklist, arraycopy_worklist);
304 if (C->failing()) return false;
305 C->print_method(PHASE_AFTER_EA, 2);
306
307 #ifdef ASSERT
308 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
309 tty->print("=== No allocations eliminated for ");
310 C->method()->print_short_name();
311 if(!EliminateAllocations) {
312 tty->print(" since EliminateAllocations is off ===");
313 } else if(!has_scalar_replaceable_candidates) {
314 tty->print(" since there are no scalar replaceable candidates ===");
315 } else if(C->AliasLevel() < 3) {
316 tty->print(" since AliasLevel < 3 ===");
317 }
318 tty->cr();
319 #endif
320 }
321 return has_non_escaping_obj;
322 }
323
324 // Utility function for nodes that load an object
325 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
326 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
327 // ThreadLocal has RawPtr type.
328 const Type* t = _igvn->type(n);
329 if (t->make_ptr() != NULL) {
330 Node* adr = n->in(MemNode::Address);
331 #ifdef ASSERT
332 if (!adr->is_AddP()) {
333 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
334 } else {
335 assert((ptnode_adr(adr->_idx) == NULL ||
336 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
337 }
338 #endif
339 add_local_var_and_edge(n, PointsToNode::NoEscape,
340 adr, delayed_worklist);
341 }
342 }
343
344 // Populate Connection Graph with PointsTo nodes and create simple
345 // connection graph edges.
346 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
347 assert(!_verify, "this method should not be called for verification");
348 PhaseGVN* igvn = _igvn;
349 uint n_idx = n->_idx;
350 PointsToNode* n_ptn = ptnode_adr(n_idx);
351 if (n_ptn != NULL)
352 return; // No need to redefine PointsTo node during first iteration.
353
354 if (n->is_Call()) {
355 // Arguments to allocation and locking don't escape.
356 if (n->is_AbstractLock()) {
357 // Put Lock and Unlock nodes on IGVN worklist to process them during
358 // first IGVN optimization when escape information is still available.
359 record_for_optimizer(n);
360 } else if (n->is_Allocate()) {
361 add_call_node(n->as_Call());
362 record_for_optimizer(n);
363 } else {
364 if (n->is_CallStaticJava()) {
365 const char* name = n->as_CallStaticJava()->_name;
366 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
367 return; // Skip uncommon traps
368 }
369 // Don't mark as processed since call's arguments have to be processed.
370 delayed_worklist->push(n);
371 // Check if a call returns an object.
372 if ((n->as_Call()->returns_pointer() &&
373 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
374 (n->is_CallStaticJava() &&
375 n->as_CallStaticJava()->is_boxing_method())) {
376 add_call_node(n->as_Call());
377 }
378 }
379 return;
380 }
381 // Put this check here to process call arguments since some call nodes
382 // point to phantom_obj.
383 if (n_ptn == phantom_obj || n_ptn == null_obj)
384 return; // Skip predefined nodes.
385
386 int opcode = n->Opcode();
387 switch (opcode) {
388 case Op_AddP: {
389 Node* base = get_addp_base(n);
390 PointsToNode* ptn_base = ptnode_adr(base->_idx);
391 // Field nodes are created for all field types. They are used in
392 // adjust_scalar_replaceable_state() and split_unique_types().
393 // Note, non-oop fields will have only base edges in Connection
394 // Graph because such fields are not used for oop loads and stores.
395 int offset = address_offset(n, igvn);
396 add_field(n, PointsToNode::NoEscape, offset);
397 if (ptn_base == NULL) {
398 delayed_worklist->push(n); // Process it later.
399 } else {
400 n_ptn = ptnode_adr(n_idx);
401 add_base(n_ptn->as_Field(), ptn_base);
402 }
403 break;
404 }
405 case Op_CastX2P: {
406 map_ideal_node(n, phantom_obj);
407 break;
408 }
409 case Op_CastPP:
410 case Op_CheckCastPP:
411 case Op_EncodeP:
412 case Op_DecodeN:
413 case Op_EncodePKlass:
414 case Op_DecodeNKlass: {
415 add_local_var_and_edge(n, PointsToNode::NoEscape,
416 n->in(1), delayed_worklist);
417 break;
418 }
419 case Op_CMoveP: {
420 add_local_var(n, PointsToNode::NoEscape);
421 // Do not add edges during first iteration because some could be
422 // not defined yet.
423 delayed_worklist->push(n);
424 break;
425 }
426 case Op_ConP:
427 case Op_ConN:
428 case Op_ConNKlass: {
429 // assume all oop constants globally escape except for null
430 PointsToNode::EscapeState es;
431 const Type* t = igvn->type(n);
432 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
433 es = PointsToNode::NoEscape;
434 } else {
435 es = PointsToNode::GlobalEscape;
436 }
437 add_java_object(n, es);
438 break;
439 }
440 case Op_CreateEx: {
441 // assume that all exception objects globally escape
442 map_ideal_node(n, phantom_obj);
443 break;
444 }
445 case Op_LoadKlass:
446 case Op_LoadNKlass: {
447 // Unknown class is loaded
448 map_ideal_node(n, phantom_obj);
449 break;
450 }
451 case Op_LoadP:
452 case Op_LoadN:
453 case Op_LoadPLocked: {
454 add_objload_to_connection_graph(n, delayed_worklist);
455 break;
456 }
457 case Op_Parm: {
458 map_ideal_node(n, phantom_obj);
459 break;
460 }
461 case Op_PartialSubtypeCheck: {
462 // Produces Null or notNull and is used in only in CmpP so
463 // phantom_obj could be used.
464 map_ideal_node(n, phantom_obj); // Result is unknown
465 break;
466 }
467 case Op_Phi: {
468 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
469 // ThreadLocal has RawPtr type.
470 const Type* t = n->as_Phi()->type();
471 if (t->make_ptr() != NULL) {
472 add_local_var(n, PointsToNode::NoEscape);
473 // Do not add edges during first iteration because some could be
474 // not defined yet.
475 delayed_worklist->push(n);
476 }
477 break;
478 }
479 case Op_Proj: {
480 // we are only interested in the oop result projection from a call
481 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
482 n->in(0)->as_Call()->returns_pointer()) {
483 add_local_var_and_edge(n, PointsToNode::NoEscape,
484 n->in(0), delayed_worklist);
485 }
486 break;
487 }
488 case Op_Rethrow: // Exception object escapes
489 case Op_Return: {
490 if (n->req() > TypeFunc::Parms &&
491 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
492 // Treat Return value as LocalVar with GlobalEscape escape state.
493 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
494 n->in(TypeFunc::Parms), delayed_worklist);
495 }
496 break;
497 }
498 case Op_CompareAndExchangeP:
499 case Op_CompareAndExchangeN:
500 case Op_GetAndSetP:
501 case Op_GetAndSetN: {
502 add_objload_to_connection_graph(n, delayed_worklist);
503 // fallthrough
504 }
505 case Op_StoreP:
506 case Op_StoreN:
507 case Op_StoreNKlass:
508 case Op_StorePConditional:
509 case Op_WeakCompareAndSwapP:
510 case Op_WeakCompareAndSwapN:
511 case Op_CompareAndSwapP:
512 case Op_CompareAndSwapN: {
513 Node* adr = n->in(MemNode::Address);
514 const Type *adr_type = igvn->type(adr);
515 adr_type = adr_type->make_ptr();
516 if (adr_type == NULL) {
517 break; // skip dead nodes
518 }
519 if ( adr_type->isa_oopptr()
520 || ( (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
521 && adr_type == TypeRawPtr::NOTNULL
522 && adr->in(AddPNode::Address)->is_Proj()
523 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
524 delayed_worklist->push(n); // Process it later.
525 #ifdef ASSERT
526 assert(adr->is_AddP(), "expecting an AddP");
527 if (adr_type == TypeRawPtr::NOTNULL) {
528 // Verify a raw address for a store captured by Initialize node.
529 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
530 assert(offs != Type::OffsetBot, "offset must be a constant");
531 }
532 #endif
533 } else {
534 // Ignore copy the displaced header to the BoxNode (OSR compilation).
535 if (adr->is_BoxLock())
536 break;
537 // Stored value escapes in unsafe access.
538 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
539 // Pointer stores in G1 barriers looks like unsafe access.
540 // Ignore such stores to be able scalar replace non-escaping
541 // allocations.
542 #if INCLUDE_G1GC
543 if (UseG1GC && adr->is_AddP()) {
544 Node* base = get_addp_base(adr);
545 if (base->Opcode() == Op_LoadP &&
546 base->in(MemNode::Address)->is_AddP()) {
547 adr = base->in(MemNode::Address);
548 Node* tls = get_addp_base(adr);
549 if (tls->Opcode() == Op_ThreadLocal) {
550 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
551 if (offs == in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset())) {
552 break; // G1 pre barrier previous oop value store.
553 }
554 if (offs == in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset())) {
555 break; // G1 post barrier card address store.
556 }
557 }
558 }
559 }
560 #endif
561 delayed_worklist->push(n); // Process unsafe access later.
562 break;
563 }
564 #ifdef ASSERT
565 n->dump(1);
566 assert(false, "not unsafe or G1 barrier raw StoreP");
567 #endif
568 }
569 break;
570 }
571 case Op_AryEq:
572 case Op_HasNegatives:
573 case Op_StrComp:
574 case Op_StrEquals:
575 case Op_StrIndexOf:
576 case Op_StrIndexOfChar:
577 case Op_StrInflatedCopy:
578 case Op_StrCompressedCopy:
579 case Op_EncodeISOArray: {
580 add_local_var(n, PointsToNode::ArgEscape);
581 delayed_worklist->push(n); // Process it later.
582 break;
583 }
584 case Op_ThreadLocal: {
585 add_java_object(n, PointsToNode::ArgEscape);
586 break;
587 }
588 default:
589 ; // Do nothing for nodes not related to EA.
590 }
591 return;
592 }
593
594 #ifdef ASSERT
595 #define ELSE_FAIL(name) \
596 /* Should not be called for not pointer type. */ \
597 n->dump(1); \
598 assert(false, name); \
599 break;
600 #else
601 #define ELSE_FAIL(name) \
602 break;
603 #endif
604
605 // Add final simple edges to graph.
606 void ConnectionGraph::add_final_edges(Node *n) {
607 PointsToNode* n_ptn = ptnode_adr(n->_idx);
608 #ifdef ASSERT
609 if (_verify && n_ptn->is_JavaObject())
610 return; // This method does not change graph for JavaObject.
611 #endif
612
613 if (n->is_Call()) {
614 process_call_arguments(n->as_Call());
615 return;
616 }
617 assert(n->is_Store() || n->is_LoadStore() ||
618 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
619 "node should be registered already");
620 int opcode = n->Opcode();
621 switch (opcode) {
622 case Op_AddP: {
623 Node* base = get_addp_base(n);
624 PointsToNode* ptn_base = ptnode_adr(base->_idx);
625 assert(ptn_base != NULL, "field's base should be registered");
626 add_base(n_ptn->as_Field(), ptn_base);
627 break;
628 }
629 case Op_CastPP:
630 case Op_CheckCastPP:
631 case Op_EncodeP:
632 case Op_DecodeN:
633 case Op_EncodePKlass:
634 case Op_DecodeNKlass: {
635 add_local_var_and_edge(n, PointsToNode::NoEscape,
636 n->in(1), NULL);
637 break;
638 }
639 case Op_CMoveP: {
640 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
641 Node* in = n->in(i);
642 if (in == NULL)
643 continue; // ignore NULL
644 Node* uncast_in = in->uncast();
645 if (uncast_in->is_top() || uncast_in == n)
646 continue; // ignore top or inputs which go back this node
647 PointsToNode* ptn = ptnode_adr(in->_idx);
648 assert(ptn != NULL, "node should be registered");
649 add_edge(n_ptn, ptn);
650 }
651 break;
652 }
653 case Op_LoadP:
654 case Op_LoadN:
655 case Op_LoadPLocked: {
656 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
657 // ThreadLocal has RawPtr type.
658 const Type* t = _igvn->type(n);
659 if (t->make_ptr() != NULL) {
660 Node* adr = n->in(MemNode::Address);
661 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
662 break;
663 }
664 ELSE_FAIL("Op_LoadP");
665 }
666 case Op_Phi: {
667 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
668 // ThreadLocal has RawPtr type.
669 const Type* t = n->as_Phi()->type();
670 if (t->make_ptr() != NULL) {
671 for (uint i = 1; i < n->req(); i++) {
672 Node* in = n->in(i);
673 if (in == NULL)
674 continue; // ignore NULL
675 Node* uncast_in = in->uncast();
676 if (uncast_in->is_top() || uncast_in == n)
677 continue; // ignore top or inputs which go back this node
678 PointsToNode* ptn = ptnode_adr(in->_idx);
679 assert(ptn != NULL, "node should be registered");
680 add_edge(n_ptn, ptn);
681 }
682 break;
683 }
684 ELSE_FAIL("Op_Phi");
685 }
686 case Op_Proj: {
687 // we are only interested in the oop result projection from a call
688 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
689 n->in(0)->as_Call()->returns_pointer()) {
690 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
691 break;
692 }
693 ELSE_FAIL("Op_Proj");
694 }
695 case Op_Rethrow: // Exception object escapes
696 case Op_Return: {
697 if (n->req() > TypeFunc::Parms &&
698 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
699 // Treat Return value as LocalVar with GlobalEscape escape state.
700 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
701 n->in(TypeFunc::Parms), NULL);
702 break;
703 }
704 ELSE_FAIL("Op_Return");
705 }
706 case Op_StoreP:
707 case Op_StoreN:
708 case Op_StoreNKlass:
709 case Op_StorePConditional:
710 case Op_CompareAndExchangeP:
711 case Op_CompareAndExchangeN:
712 case Op_CompareAndSwapP:
713 case Op_CompareAndSwapN:
714 case Op_WeakCompareAndSwapP:
715 case Op_WeakCompareAndSwapN:
716 case Op_GetAndSetP:
717 case Op_GetAndSetN: {
718 Node* adr = n->in(MemNode::Address);
719 const Type *adr_type = _igvn->type(adr);
720 adr_type = adr_type->make_ptr();
721 #ifdef ASSERT
722 if (adr_type == NULL) {
723 n->dump(1);
724 assert(adr_type != NULL, "dead node should not be on list");
725 break;
726 }
727 #endif
728 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
729 opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
730 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
731 }
732 if ( adr_type->isa_oopptr()
733 || ( (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
734 && adr_type == TypeRawPtr::NOTNULL
735 && adr->in(AddPNode::Address)->is_Proj()
736 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
737 // Point Address to Value
738 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
739 assert(adr_ptn != NULL &&
740 adr_ptn->as_Field()->is_oop(), "node should be registered");
741 Node *val = n->in(MemNode::ValueIn);
742 PointsToNode* ptn = ptnode_adr(val->_idx);
743 assert(ptn != NULL, "node should be registered");
744 add_edge(adr_ptn, ptn);
745 break;
746 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
747 // Stored value escapes in unsafe access.
748 Node *val = n->in(MemNode::ValueIn);
749 PointsToNode* ptn = ptnode_adr(val->_idx);
750 assert(ptn != NULL, "node should be registered");
751 set_escape_state(ptn, PointsToNode::GlobalEscape);
752 // Add edge to object for unsafe access with offset.
753 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
754 assert(adr_ptn != NULL, "node should be registered");
755 if (adr_ptn->is_Field()) {
756 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
757 add_edge(adr_ptn, ptn);
758 }
759 break;
760 }
761 ELSE_FAIL("Op_StoreP");
762 }
763 case Op_AryEq:
764 case Op_HasNegatives:
765 case Op_StrComp:
766 case Op_StrEquals:
767 case Op_StrIndexOf:
768 case Op_StrIndexOfChar:
769 case Op_StrInflatedCopy:
770 case Op_StrCompressedCopy:
771 case Op_EncodeISOArray: {
772 // char[]/byte[] arrays passed to string intrinsic do not escape but
773 // they are not scalar replaceable. Adjust escape state for them.
774 // Start from in(2) edge since in(1) is memory edge.
775 for (uint i = 2; i < n->req(); i++) {
776 Node* adr = n->in(i);
777 const Type* at = _igvn->type(adr);
778 if (!adr->is_top() && at->isa_ptr()) {
779 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
780 at->isa_ptr() != NULL, "expecting a pointer");
781 if (adr->is_AddP()) {
782 adr = get_addp_base(adr);
783 }
784 PointsToNode* ptn = ptnode_adr(adr->_idx);
785 assert(ptn != NULL, "node should be registered");
786 add_edge(n_ptn, ptn);
787 }
788 }
789 break;
790 }
791 default: {
792 // This method should be called only for EA specific nodes which may
793 // miss some edges when they were created.
794 #ifdef ASSERT
795 n->dump(1);
796 #endif
797 guarantee(false, "unknown node");
798 }
799 }
800 return;
801 }
802
803 void ConnectionGraph::add_call_node(CallNode* call) {
804 assert(call->returns_pointer(), "only for call which returns pointer");
805 uint call_idx = call->_idx;
806 if (call->is_Allocate()) {
807 Node* k = call->in(AllocateNode::KlassNode);
808 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
809 assert(kt != NULL, "TypeKlassPtr required.");
810 ciKlass* cik = kt->klass();
811 PointsToNode::EscapeState es = PointsToNode::NoEscape;
812 bool scalar_replaceable = true;
813 if (call->is_AllocateArray()) {
814 if (!cik->is_array_klass()) { // StressReflectiveCode
815 es = PointsToNode::GlobalEscape;
816 } else {
817 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
818 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
819 // Not scalar replaceable if the length is not constant or too big.
820 scalar_replaceable = false;
821 }
822 }
823 } else { // Allocate instance
824 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
825 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
826 !cik->is_instance_klass() || // StressReflectiveCode
827 !cik->as_instance_klass()->can_be_instantiated() ||
828 cik->as_instance_klass()->has_finalizer()) {
829 es = PointsToNode::GlobalEscape;
830 }
831 }
832 add_java_object(call, es);
833 PointsToNode* ptn = ptnode_adr(call_idx);
834 if (!scalar_replaceable && ptn->scalar_replaceable()) {
835 ptn->set_scalar_replaceable(false);
836 }
837 } else if (call->is_CallStaticJava()) {
838 // Call nodes could be different types:
839 //
840 // 1. CallDynamicJavaNode (what happened during call is unknown):
841 //
842 // - mapped to GlobalEscape JavaObject node if oop is returned;
843 //
844 // - all oop arguments are escaping globally;
845 //
846 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
847 //
848 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
849 //
850 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
851 // - mapped to NoEscape JavaObject node if non-escaping object allocated
852 // during call is returned;
853 // - mapped to ArgEscape LocalVar node pointed to object arguments
854 // which are returned and does not escape during call;
855 //
856 // - oop arguments escaping status is defined by bytecode analysis;
857 //
858 // For a static call, we know exactly what method is being called.
859 // Use bytecode estimator to record whether the call's return value escapes.
860 ciMethod* meth = call->as_CallJava()->method();
861 if (meth == NULL) {
862 const char* name = call->as_CallStaticJava()->_name;
863 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
864 // Returns a newly allocated unescaped object.
865 add_java_object(call, PointsToNode::NoEscape);
866 ptnode_adr(call_idx)->set_scalar_replaceable(false);
867 } else if (meth->is_boxing_method()) {
868 // Returns boxing object
869 PointsToNode::EscapeState es;
870 vmIntrinsics::ID intr = meth->intrinsic_id();
871 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
872 // It does not escape if object is always allocated.
873 es = PointsToNode::NoEscape;
874 } else {
875 // It escapes globally if object could be loaded from cache.
876 es = PointsToNode::GlobalEscape;
877 }
878 add_java_object(call, es);
879 } else {
880 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
881 call_analyzer->copy_dependencies(_compile->dependencies());
882 if (call_analyzer->is_return_allocated()) {
883 // Returns a newly allocated unescaped object, simply
884 // update dependency information.
885 // Mark it as NoEscape so that objects referenced by
886 // it's fields will be marked as NoEscape at least.
887 add_java_object(call, PointsToNode::NoEscape);
888 ptnode_adr(call_idx)->set_scalar_replaceable(false);
889 } else {
890 // Determine whether any arguments are returned.
891 const TypeTuple* d = call->tf()->domain();
892 bool ret_arg = false;
893 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
894 if (d->field_at(i)->isa_ptr() != NULL &&
895 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
896 ret_arg = true;
897 break;
898 }
899 }
900 if (ret_arg) {
901 add_local_var(call, PointsToNode::ArgEscape);
902 } else {
903 // Returns unknown object.
904 map_ideal_node(call, phantom_obj);
905 }
906 }
907 }
908 } else {
909 // An other type of call, assume the worst case:
910 // returned value is unknown and globally escapes.
911 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
912 map_ideal_node(call, phantom_obj);
913 }
914 }
915
916 void ConnectionGraph::process_call_arguments(CallNode *call) {
917 bool is_arraycopy = false;
918 switch (call->Opcode()) {
919 #ifdef ASSERT
920 case Op_Allocate:
921 case Op_AllocateArray:
922 case Op_Lock:
923 case Op_Unlock:
924 assert(false, "should be done already");
925 break;
926 #endif
927 case Op_ArrayCopy:
928 case Op_CallLeafNoFP:
929 // Most array copies are ArrayCopy nodes at this point but there
930 // are still a few direct calls to the copy subroutines (See
931 // PhaseStringOpts::copy_string())
932 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
933 call->as_CallLeaf()->is_call_to_arraycopystub();
934 // fall through
935 case Op_CallLeaf: {
936 // Stub calls, objects do not escape but they are not scale replaceable.
937 // Adjust escape state for outgoing arguments.
938 const TypeTuple * d = call->tf()->domain();
939 bool src_has_oops = false;
940 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
941 const Type* at = d->field_at(i);
942 Node *arg = call->in(i);
943 if (arg == NULL) {
944 continue;
945 }
946 const Type *aat = _igvn->type(arg);
947 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
948 continue;
949 if (arg->is_AddP()) {
950 //
951 // The inline_native_clone() case when the arraycopy stub is called
952 // after the allocation before Initialize and CheckCastPP nodes.
953 // Or normal arraycopy for object arrays case.
954 //
955 // Set AddP's base (Allocate) as not scalar replaceable since
956 // pointer to the base (with offset) is passed as argument.
957 //
958 arg = get_addp_base(arg);
959 }
960 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
961 assert(arg_ptn != NULL, "should be registered");
962 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
963 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
964 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
965 aat->isa_ptr() != NULL, "expecting an Ptr");
966 bool arg_has_oops = aat->isa_oopptr() &&
967 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
968 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
969 if (i == TypeFunc::Parms) {
970 src_has_oops = arg_has_oops;
971 }
972 //
973 // src or dst could be j.l.Object when other is basic type array:
974 //
975 // arraycopy(char[],0,Object*,0,size);
976 // arraycopy(Object*,0,char[],0,size);
977 //
978 // Don't add edges in such cases.
979 //
980 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
981 arg_has_oops && (i > TypeFunc::Parms);
982 #ifdef ASSERT
983 if (!(is_arraycopy ||
984 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
985 (call->as_CallLeaf()->_name != NULL &&
986 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
993 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1002 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1003 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1004 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1005 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1006 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1007 ))) {
1008 call->dump();
1009 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1010 }
1011 #endif
1012 // Always process arraycopy's destination object since
1013 // we need to add all possible edges to references in
1014 // source object.
1015 if (arg_esc >= PointsToNode::ArgEscape &&
1016 !arg_is_arraycopy_dest) {
1017 continue;
1018 }
1019 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1020 if (call->is_ArrayCopy()) {
1021 ArrayCopyNode* ac = call->as_ArrayCopy();
1022 if (ac->is_clonebasic() ||
1023 ac->is_arraycopy_validated() ||
1024 ac->is_copyof_validated() ||
1025 ac->is_copyofrange_validated()) {
1026 es = PointsToNode::NoEscape;
1027 }
1028 }
1029 set_escape_state(arg_ptn, es);
1030 if (arg_is_arraycopy_dest) {
1031 Node* src = call->in(TypeFunc::Parms);
1032 if (src->is_AddP()) {
1033 src = get_addp_base(src);
1034 }
1035 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1036 assert(src_ptn != NULL, "should be registered");
1037 if (arg_ptn != src_ptn) {
1038 // Special arraycopy edge:
1039 // A destination object's field can't have the source object
1040 // as base since objects escape states are not related.
1041 // Only escape state of destination object's fields affects
1042 // escape state of fields in source object.
1043 add_arraycopy(call, es, src_ptn, arg_ptn);
1044 }
1045 }
1046 }
1047 }
1048 break;
1049 }
1050 case Op_CallStaticJava: {
1051 // For a static call, we know exactly what method is being called.
1052 // Use bytecode estimator to record the call's escape affects
1053 #ifdef ASSERT
1054 const char* name = call->as_CallStaticJava()->_name;
1055 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1056 #endif
1057 ciMethod* meth = call->as_CallJava()->method();
1058 if ((meth != NULL) && meth->is_boxing_method()) {
1059 break; // Boxing methods do not modify any oops.
1060 }
1061 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1062 // fall-through if not a Java method or no analyzer information
1063 if (call_analyzer != NULL) {
1064 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1065 const TypeTuple* d = call->tf()->domain();
1066 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1067 const Type* at = d->field_at(i);
1068 int k = i - TypeFunc::Parms;
1069 Node* arg = call->in(i);
1070 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1071 if (at->isa_ptr() != NULL &&
1072 call_analyzer->is_arg_returned(k)) {
1073 // The call returns arguments.
1074 if (call_ptn != NULL) { // Is call's result used?
1075 assert(call_ptn->is_LocalVar(), "node should be registered");
1076 assert(arg_ptn != NULL, "node should be registered");
1077 add_edge(call_ptn, arg_ptn);
1078 }
1079 }
1080 if (at->isa_oopptr() != NULL &&
1081 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1082 if (!call_analyzer->is_arg_stack(k)) {
1083 // The argument global escapes
1084 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1085 } else {
1086 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1087 if (!call_analyzer->is_arg_local(k)) {
1088 // The argument itself doesn't escape, but any fields might
1089 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1090 }
1091 }
1092 }
1093 }
1094 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1095 // The call returns arguments.
1096 assert(call_ptn->edge_count() > 0, "sanity");
1097 if (!call_analyzer->is_return_local()) {
1098 // Returns also unknown object.
1099 add_edge(call_ptn, phantom_obj);
1100 }
1101 }
1102 break;
1103 }
1104 }
1105 default: {
1106 // Fall-through here if not a Java method or no analyzer information
1107 // or some other type of call, assume the worst case: all arguments
1108 // globally escape.
1109 const TypeTuple* d = call->tf()->domain();
1110 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1111 const Type* at = d->field_at(i);
1112 if (at->isa_oopptr() != NULL) {
1113 Node* arg = call->in(i);
1114 if (arg->is_AddP()) {
1115 arg = get_addp_base(arg);
1116 }
1117 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1118 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1119 }
1120 }
1121 }
1122 }
1123 }
1124
1125
1126 // Finish Graph construction.
1127 bool ConnectionGraph::complete_connection_graph(
1128 GrowableArray<PointsToNode*>& ptnodes_worklist,
1129 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1130 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1131 GrowableArray<FieldNode*>& oop_fields_worklist) {
1132 // Normally only 1-3 passes needed to build Connection Graph depending
1133 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1134 // Set limit to 20 to catch situation when something did go wrong and
1135 // bailout Escape Analysis.
1136 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1137 #define CG_BUILD_ITER_LIMIT 20
1138
1139 // Propagate GlobalEscape and ArgEscape escape states and check that
1140 // we still have non-escaping objects. The method pushs on _worklist
1141 // Field nodes which reference phantom_object.
1142 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1143 return false; // Nothing to do.
1144 }
1145 // Now propagate references to all JavaObject nodes.
1146 int java_objects_length = java_objects_worklist.length();
1147 elapsedTimer time;
1148 bool timeout = false;
1149 int new_edges = 1;
1150 int iterations = 0;
1151 do {
1152 while ((new_edges > 0) &&
1153 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1154 double start_time = time.seconds();
1155 time.start();
1156 new_edges = 0;
1157 // Propagate references to phantom_object for nodes pushed on _worklist
1158 // by find_non_escaped_objects() and find_field_value().
1159 new_edges += add_java_object_edges(phantom_obj, false);
1160 for (int next = 0; next < java_objects_length; ++next) {
1161 JavaObjectNode* ptn = java_objects_worklist.at(next);
1162 new_edges += add_java_object_edges(ptn, true);
1163
1164 #define SAMPLE_SIZE 4
1165 if ((next % SAMPLE_SIZE) == 0) {
1166 // Each 4 iterations calculate how much time it will take
1167 // to complete graph construction.
1168 time.stop();
1169 // Poll for requests from shutdown mechanism to quiesce compiler
1170 // because Connection graph construction may take long time.
1171 CompileBroker::maybe_block();
1172 double stop_time = time.seconds();
1173 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1174 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1175 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1176 timeout = true;
1177 break; // Timeout
1178 }
1179 start_time = stop_time;
1180 time.start();
1181 }
1182 #undef SAMPLE_SIZE
1183
1184 }
1185 if (timeout) break;
1186 if (new_edges > 0) {
1187 // Update escape states on each iteration if graph was updated.
1188 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1189 return false; // Nothing to do.
1190 }
1191 }
1192 time.stop();
1193 if (time.seconds() >= EscapeAnalysisTimeout) {
1194 timeout = true;
1195 break;
1196 }
1197 }
1198 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1199 time.start();
1200 // Find fields which have unknown value.
1201 int fields_length = oop_fields_worklist.length();
1202 for (int next = 0; next < fields_length; next++) {
1203 FieldNode* field = oop_fields_worklist.at(next);
1204 if (field->edge_count() == 0) {
1205 new_edges += find_field_value(field);
1206 // This code may added new edges to phantom_object.
1207 // Need an other cycle to propagate references to phantom_object.
1208 }
1209 }
1210 time.stop();
1211 if (time.seconds() >= EscapeAnalysisTimeout) {
1212 timeout = true;
1213 break;
1214 }
1215 } else {
1216 new_edges = 0; // Bailout
1217 }
1218 } while (new_edges > 0);
1219
1220 // Bailout if passed limits.
1221 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1222 Compile* C = _compile;
1223 if (C->log() != NULL) {
1224 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1225 C->log()->text("%s", timeout ? "time" : "iterations");
1226 C->log()->end_elem(" limit'");
1227 }
1228 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1229 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1230 // Possible infinite build_connection_graph loop,
1231 // bailout (no changes to ideal graph were made).
1232 return false;
1233 }
1234 #ifdef ASSERT
1235 if (Verbose && PrintEscapeAnalysis) {
1236 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1237 iterations, nodes_size(), ptnodes_worklist.length());
1238 }
1239 #endif
1240
1241 #undef CG_BUILD_ITER_LIMIT
1242
1243 // Find fields initialized by NULL for non-escaping Allocations.
1244 int non_escaped_length = non_escaped_worklist.length();
1245 for (int next = 0; next < non_escaped_length; next++) {
1246 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1247 PointsToNode::EscapeState es = ptn->escape_state();
1248 assert(es <= PointsToNode::ArgEscape, "sanity");
1249 if (es == PointsToNode::NoEscape) {
1250 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1251 // Adding references to NULL object does not change escape states
1252 // since it does not escape. Also no fields are added to NULL object.
1253 add_java_object_edges(null_obj, false);
1254 }
1255 }
1256 Node* n = ptn->ideal_node();
1257 if (n->is_Allocate()) {
1258 // The object allocated by this Allocate node will never be
1259 // seen by an other thread. Mark it so that when it is
1260 // expanded no MemBarStoreStore is added.
1261 InitializeNode* ini = n->as_Allocate()->initialization();
1262 if (ini != NULL)
1263 ini->set_does_not_escape();
1264 }
1265 }
1266 return true; // Finished graph construction.
1267 }
1268
1269 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1270 // and check that we still have non-escaping java objects.
1271 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1272 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1273 GrowableArray<PointsToNode*> escape_worklist;
1274 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1275 int ptnodes_length = ptnodes_worklist.length();
1276 for (int next = 0; next < ptnodes_length; ++next) {
1277 PointsToNode* ptn = ptnodes_worklist.at(next);
1278 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1279 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1280 escape_worklist.push(ptn);
1281 }
1282 }
1283 // Set escape states to referenced nodes (edges list).
1284 while (escape_worklist.length() > 0) {
1285 PointsToNode* ptn = escape_worklist.pop();
1286 PointsToNode::EscapeState es = ptn->escape_state();
1287 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1288 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1289 es >= PointsToNode::ArgEscape) {
1290 // GlobalEscape or ArgEscape state of field means it has unknown value.
1291 if (add_edge(ptn, phantom_obj)) {
1292 // New edge was added
1293 add_field_uses_to_worklist(ptn->as_Field());
1294 }
1295 }
1296 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1297 PointsToNode* e = i.get();
1298 if (e->is_Arraycopy()) {
1299 assert(ptn->arraycopy_dst(), "sanity");
1300 // Propagate only fields escape state through arraycopy edge.
1301 if (e->fields_escape_state() < field_es) {
1302 set_fields_escape_state(e, field_es);
1303 escape_worklist.push(e);
1304 }
1305 } else if (es >= field_es) {
1306 // fields_escape_state is also set to 'es' if it is less than 'es'.
1307 if (e->escape_state() < es) {
1308 set_escape_state(e, es);
1309 escape_worklist.push(e);
1310 }
1311 } else {
1312 // Propagate field escape state.
1313 bool es_changed = false;
1314 if (e->fields_escape_state() < field_es) {
1315 set_fields_escape_state(e, field_es);
1316 es_changed = true;
1317 }
1318 if ((e->escape_state() < field_es) &&
1319 e->is_Field() && ptn->is_JavaObject() &&
1320 e->as_Field()->is_oop()) {
1321 // Change escape state of referenced fields.
1322 set_escape_state(e, field_es);
1323 es_changed = true;
1324 } else if (e->escape_state() < es) {
1325 set_escape_state(e, es);
1326 es_changed = true;
1327 }
1328 if (es_changed) {
1329 escape_worklist.push(e);
1330 }
1331 }
1332 }
1333 }
1334 // Remove escaped objects from non_escaped list.
1335 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1336 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1337 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1338 non_escaped_worklist.delete_at(next);
1339 }
1340 if (ptn->escape_state() == PointsToNode::NoEscape) {
1341 // Find fields in non-escaped allocations which have unknown value.
1342 find_init_values(ptn, phantom_obj, NULL);
1343 }
1344 }
1345 return (non_escaped_worklist.length() > 0);
1346 }
1347
1348 // Add all references to JavaObject node by walking over all uses.
1349 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1350 int new_edges = 0;
1351 if (populate_worklist) {
1352 // Populate _worklist by uses of jobj's uses.
1353 for (UseIterator i(jobj); i.has_next(); i.next()) {
1354 PointsToNode* use = i.get();
1355 if (use->is_Arraycopy())
1356 continue;
1357 add_uses_to_worklist(use);
1358 if (use->is_Field() && use->as_Field()->is_oop()) {
1359 // Put on worklist all field's uses (loads) and
1360 // related field nodes (same base and offset).
1361 add_field_uses_to_worklist(use->as_Field());
1362 }
1363 }
1364 }
1365 for (int l = 0; l < _worklist.length(); l++) {
1366 PointsToNode* use = _worklist.at(l);
1367 if (PointsToNode::is_base_use(use)) {
1368 // Add reference from jobj to field and from field to jobj (field's base).
1369 use = PointsToNode::get_use_node(use)->as_Field();
1370 if (add_base(use->as_Field(), jobj)) {
1371 new_edges++;
1372 }
1373 continue;
1374 }
1375 assert(!use->is_JavaObject(), "sanity");
1376 if (use->is_Arraycopy()) {
1377 if (jobj == null_obj) // NULL object does not have field edges
1378 continue;
1379 // Added edge from Arraycopy node to arraycopy's source java object
1380 if (add_edge(use, jobj)) {
1381 jobj->set_arraycopy_src();
1382 new_edges++;
1383 }
1384 // and stop here.
1385 continue;
1386 }
1387 if (!add_edge(use, jobj))
1388 continue; // No new edge added, there was such edge already.
1389 new_edges++;
1390 if (use->is_LocalVar()) {
1391 add_uses_to_worklist(use);
1392 if (use->arraycopy_dst()) {
1393 for (EdgeIterator i(use); i.has_next(); i.next()) {
1394 PointsToNode* e = i.get();
1395 if (e->is_Arraycopy()) {
1396 if (jobj == null_obj) // NULL object does not have field edges
1397 continue;
1398 // Add edge from arraycopy's destination java object to Arraycopy node.
1399 if (add_edge(jobj, e)) {
1400 new_edges++;
1401 jobj->set_arraycopy_dst();
1402 }
1403 }
1404 }
1405 }
1406 } else {
1407 // Added new edge to stored in field values.
1408 // Put on worklist all field's uses (loads) and
1409 // related field nodes (same base and offset).
1410 add_field_uses_to_worklist(use->as_Field());
1411 }
1412 }
1413 _worklist.clear();
1414 _in_worklist.Reset();
1415 return new_edges;
1416 }
1417
1418 // Put on worklist all related field nodes.
1419 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1420 assert(field->is_oop(), "sanity");
1421 int offset = field->offset();
1422 add_uses_to_worklist(field);
1423 // Loop over all bases of this field and push on worklist Field nodes
1424 // with the same offset and base (since they may reference the same field).
1425 for (BaseIterator i(field); i.has_next(); i.next()) {
1426 PointsToNode* base = i.get();
1427 add_fields_to_worklist(field, base);
1428 // Check if the base was source object of arraycopy and go over arraycopy's
1429 // destination objects since values stored to a field of source object are
1430 // accessable by uses (loads) of fields of destination objects.
1431 if (base->arraycopy_src()) {
1432 for (UseIterator j(base); j.has_next(); j.next()) {
1433 PointsToNode* arycp = j.get();
1434 if (arycp->is_Arraycopy()) {
1435 for (UseIterator k(arycp); k.has_next(); k.next()) {
1436 PointsToNode* abase = k.get();
1437 if (abase->arraycopy_dst() && abase != base) {
1438 // Look for the same arraycopy reference.
1439 add_fields_to_worklist(field, abase);
1440 }
1441 }
1442 }
1443 }
1444 }
1445 }
1446 }
1447
1448 // Put on worklist all related field nodes.
1449 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1450 int offset = field->offset();
1451 if (base->is_LocalVar()) {
1452 for (UseIterator j(base); j.has_next(); j.next()) {
1453 PointsToNode* f = j.get();
1454 if (PointsToNode::is_base_use(f)) { // Field
1455 f = PointsToNode::get_use_node(f);
1456 if (f == field || !f->as_Field()->is_oop())
1457 continue;
1458 int offs = f->as_Field()->offset();
1459 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1460 add_to_worklist(f);
1461 }
1462 }
1463 }
1464 } else {
1465 assert(base->is_JavaObject(), "sanity");
1466 if (// Skip phantom_object since it is only used to indicate that
1467 // this field's content globally escapes.
1468 (base != phantom_obj) &&
1469 // NULL object node does not have fields.
1470 (base != null_obj)) {
1471 for (EdgeIterator i(base); i.has_next(); i.next()) {
1472 PointsToNode* f = i.get();
1473 // Skip arraycopy edge since store to destination object field
1474 // does not update value in source object field.
1475 if (f->is_Arraycopy()) {
1476 assert(base->arraycopy_dst(), "sanity");
1477 continue;
1478 }
1479 if (f == field || !f->as_Field()->is_oop())
1480 continue;
1481 int offs = f->as_Field()->offset();
1482 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1483 add_to_worklist(f);
1484 }
1485 }
1486 }
1487 }
1488 }
1489
1490 // Find fields which have unknown value.
1491 int ConnectionGraph::find_field_value(FieldNode* field) {
1492 // Escaped fields should have init value already.
1493 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1494 int new_edges = 0;
1495 for (BaseIterator i(field); i.has_next(); i.next()) {
1496 PointsToNode* base = i.get();
1497 if (base->is_JavaObject()) {
1498 // Skip Allocate's fields which will be processed later.
1499 if (base->ideal_node()->is_Allocate())
1500 return 0;
1501 assert(base == null_obj, "only NULL ptr base expected here");
1502 }
1503 }
1504 if (add_edge(field, phantom_obj)) {
1505 // New edge was added
1506 new_edges++;
1507 add_field_uses_to_worklist(field);
1508 }
1509 return new_edges;
1510 }
1511
1512 // Find fields initializing values for allocations.
1513 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1514 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1515 int new_edges = 0;
1516 Node* alloc = pta->ideal_node();
1517 if (init_val == phantom_obj) {
1518 // Do nothing for Allocate nodes since its fields values are
1519 // "known" unless they are initialized by arraycopy/clone.
1520 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1521 return 0;
1522 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1523 #ifdef ASSERT
1524 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1525 const char* name = alloc->as_CallStaticJava()->_name;
1526 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1527 }
1528 #endif
1529 // Non-escaped allocation returned from Java or runtime call have
1530 // unknown values in fields.
1531 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1532 PointsToNode* field = i.get();
1533 if (field->is_Field() && field->as_Field()->is_oop()) {
1534 if (add_edge(field, phantom_obj)) {
1535 // New edge was added
1536 new_edges++;
1537 add_field_uses_to_worklist(field->as_Field());
1538 }
1539 }
1540 }
1541 return new_edges;
1542 }
1543 assert(init_val == null_obj, "sanity");
1544 // Do nothing for Call nodes since its fields values are unknown.
1545 if (!alloc->is_Allocate())
1546 return 0;
1547
1548 InitializeNode* ini = alloc->as_Allocate()->initialization();
1549 bool visited_bottom_offset = false;
1550 GrowableArray<int> offsets_worklist;
1551
1552 // Check if an oop field's initializing value is recorded and add
1553 // a corresponding NULL if field's value if it is not recorded.
1554 // Connection Graph does not record a default initialization by NULL
1555 // captured by Initialize node.
1556 //
1557 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1558 PointsToNode* field = i.get(); // Field (AddP)
1559 if (!field->is_Field() || !field->as_Field()->is_oop())
1560 continue; // Not oop field
1561 int offset = field->as_Field()->offset();
1562 if (offset == Type::OffsetBot) {
1563 if (!visited_bottom_offset) {
1564 // OffsetBot is used to reference array's element,
1565 // always add reference to NULL to all Field nodes since we don't
1566 // known which element is referenced.
1567 if (add_edge(field, null_obj)) {
1568 // New edge was added
1569 new_edges++;
1570 add_field_uses_to_worklist(field->as_Field());
1571 visited_bottom_offset = true;
1572 }
1573 }
1574 } else {
1575 // Check only oop fields.
1576 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1577 if (adr_type->isa_rawptr()) {
1578 #ifdef ASSERT
1579 // Raw pointers are used for initializing stores so skip it
1580 // since it should be recorded already
1581 Node* base = get_addp_base(field->ideal_node());
1582 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1583 (base->in(0) == alloc),"unexpected pointer type");
1584 #endif
1585 continue;
1586 }
1587 if (!offsets_worklist.contains(offset)) {
1588 offsets_worklist.append(offset);
1589 Node* value = NULL;
1590 if (ini != NULL) {
1591 // StoreP::memory_type() == T_ADDRESS
1592 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1593 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1594 // Make sure initializing store has the same type as this AddP.
1595 // This AddP may reference non existing field because it is on a
1596 // dead branch of bimorphic call which is not eliminated yet.
1597 if (store != NULL && store->is_Store() &&
1598 store->as_Store()->memory_type() == ft) {
1599 value = store->in(MemNode::ValueIn);
1600 #ifdef ASSERT
1601 if (VerifyConnectionGraph) {
1602 // Verify that AddP already points to all objects the value points to.
1603 PointsToNode* val = ptnode_adr(value->_idx);
1604 assert((val != NULL), "should be processed already");
1605 PointsToNode* missed_obj = NULL;
1606 if (val->is_JavaObject()) {
1607 if (!field->points_to(val->as_JavaObject())) {
1608 missed_obj = val;
1609 }
1610 } else {
1611 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1612 tty->print_cr("----------init store has invalid value -----");
1613 store->dump();
1614 val->dump();
1615 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1616 }
1617 for (EdgeIterator j(val); j.has_next(); j.next()) {
1618 PointsToNode* obj = j.get();
1619 if (obj->is_JavaObject()) {
1620 if (!field->points_to(obj->as_JavaObject())) {
1621 missed_obj = obj;
1622 break;
1623 }
1624 }
1625 }
1626 }
1627 if (missed_obj != NULL) {
1628 tty->print_cr("----------field---------------------------------");
1629 field->dump();
1630 tty->print_cr("----------missed referernce to object-----------");
1631 missed_obj->dump();
1632 tty->print_cr("----------object referernced by init store -----");
1633 store->dump();
1634 val->dump();
1635 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1636 }
1637 }
1638 #endif
1639 } else {
1640 // There could be initializing stores which follow allocation.
1641 // For example, a volatile field store is not collected
1642 // by Initialize node.
1643 //
1644 // Need to check for dependent loads to separate such stores from
1645 // stores which follow loads. For now, add initial value NULL so
1646 // that compare pointers optimization works correctly.
1647 }
1648 }
1649 if (value == NULL) {
1650 // A field's initializing value was not recorded. Add NULL.
1651 if (add_edge(field, null_obj)) {
1652 // New edge was added
1653 new_edges++;
1654 add_field_uses_to_worklist(field->as_Field());
1655 }
1656 }
1657 }
1658 }
1659 }
1660 return new_edges;
1661 }
1662
1663 // Adjust scalar_replaceable state after Connection Graph is built.
1664 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1665 // Search for non-escaping objects which are not scalar replaceable
1666 // and mark them to propagate the state to referenced objects.
1667
1668 // 1. An object is not scalar replaceable if the field into which it is
1669 // stored has unknown offset (stored into unknown element of an array).
1670 //
1671 for (UseIterator i(jobj); i.has_next(); i.next()) {
1672 PointsToNode* use = i.get();
1673 if (use->is_Arraycopy()) {
1674 continue;
1675 }
1676 if (use->is_Field()) {
1677 FieldNode* field = use->as_Field();
1678 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1679 if (field->offset() == Type::OffsetBot) {
1680 jobj->set_scalar_replaceable(false);
1681 return;
1682 }
1683 // 2. An object is not scalar replaceable if the field into which it is
1684 // stored has multiple bases one of which is null.
1685 if (field->base_count() > 1) {
1686 for (BaseIterator i(field); i.has_next(); i.next()) {
1687 PointsToNode* base = i.get();
1688 if (base == null_obj) {
1689 jobj->set_scalar_replaceable(false);
1690 return;
1691 }
1692 }
1693 }
1694 }
1695 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1696 // 3. An object is not scalar replaceable if it is merged with other objects.
1697 for (EdgeIterator j(use); j.has_next(); j.next()) {
1698 PointsToNode* ptn = j.get();
1699 if (ptn->is_JavaObject() && ptn != jobj) {
1700 // Mark all objects.
1701 jobj->set_scalar_replaceable(false);
1702 ptn->set_scalar_replaceable(false);
1703 }
1704 }
1705 if (!jobj->scalar_replaceable()) {
1706 return;
1707 }
1708 }
1709
1710 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1711 if (j.get()->is_Arraycopy()) {
1712 continue;
1713 }
1714
1715 // Non-escaping object node should point only to field nodes.
1716 FieldNode* field = j.get()->as_Field();
1717 int offset = field->as_Field()->offset();
1718
1719 // 4. An object is not scalar replaceable if it has a field with unknown
1720 // offset (array's element is accessed in loop).
1721 if (offset == Type::OffsetBot) {
1722 jobj->set_scalar_replaceable(false);
1723 return;
1724 }
1725 // 5. Currently an object is not scalar replaceable if a LoadStore node
1726 // access its field since the field value is unknown after it.
1727 //
1728 Node* n = field->ideal_node();
1729 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1730 if (n->fast_out(i)->is_LoadStore()) {
1731 jobj->set_scalar_replaceable(false);
1732 return;
1733 }
1734 }
1735
1736 // 6. Or the address may point to more then one object. This may produce
1737 // the false positive result (set not scalar replaceable)
1738 // since the flow-insensitive escape analysis can't separate
1739 // the case when stores overwrite the field's value from the case
1740 // when stores happened on different control branches.
1741 //
1742 // Note: it will disable scalar replacement in some cases:
1743 //
1744 // Point p[] = new Point[1];
1745 // p[0] = new Point(); // Will be not scalar replaced
1746 //
1747 // but it will save us from incorrect optimizations in next cases:
1748 //
1749 // Point p[] = new Point[1];
1750 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1751 //
1752 if (field->base_count() > 1) {
1753 for (BaseIterator i(field); i.has_next(); i.next()) {
1754 PointsToNode* base = i.get();
1755 // Don't take into account LocalVar nodes which
1756 // may point to only one object which should be also
1757 // this field's base by now.
1758 if (base->is_JavaObject() && base != jobj) {
1759 // Mark all bases.
1760 jobj->set_scalar_replaceable(false);
1761 base->set_scalar_replaceable(false);
1762 }
1763 }
1764 }
1765 }
1766 }
1767
1768 #ifdef ASSERT
1769 void ConnectionGraph::verify_connection_graph(
1770 GrowableArray<PointsToNode*>& ptnodes_worklist,
1771 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1772 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1773 GrowableArray<Node*>& addp_worklist) {
1774 // Verify that graph is complete - no new edges could be added.
1775 int java_objects_length = java_objects_worklist.length();
1776 int non_escaped_length = non_escaped_worklist.length();
1777 int new_edges = 0;
1778 for (int next = 0; next < java_objects_length; ++next) {
1779 JavaObjectNode* ptn = java_objects_worklist.at(next);
1780 new_edges += add_java_object_edges(ptn, true);
1781 }
1782 assert(new_edges == 0, "graph was not complete");
1783 // Verify that escape state is final.
1784 int length = non_escaped_worklist.length();
1785 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1786 assert((non_escaped_length == non_escaped_worklist.length()) &&
1787 (non_escaped_length == length) &&
1788 (_worklist.length() == 0), "escape state was not final");
1789
1790 // Verify fields information.
1791 int addp_length = addp_worklist.length();
1792 for (int next = 0; next < addp_length; ++next ) {
1793 Node* n = addp_worklist.at(next);
1794 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1795 if (field->is_oop()) {
1796 // Verify that field has all bases
1797 Node* base = get_addp_base(n);
1798 PointsToNode* ptn = ptnode_adr(base->_idx);
1799 if (ptn->is_JavaObject()) {
1800 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1801 } else {
1802 assert(ptn->is_LocalVar(), "sanity");
1803 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1804 PointsToNode* e = i.get();
1805 if (e->is_JavaObject()) {
1806 assert(field->has_base(e->as_JavaObject()), "sanity");
1807 }
1808 }
1809 }
1810 // Verify that all fields have initializing values.
1811 if (field->edge_count() == 0) {
1812 tty->print_cr("----------field does not have references----------");
1813 field->dump();
1814 for (BaseIterator i(field); i.has_next(); i.next()) {
1815 PointsToNode* base = i.get();
1816 tty->print_cr("----------field has next base---------------------");
1817 base->dump();
1818 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1819 tty->print_cr("----------base has fields-------------------------");
1820 for (EdgeIterator j(base); j.has_next(); j.next()) {
1821 j.get()->dump();
1822 }
1823 tty->print_cr("----------base has references---------------------");
1824 for (UseIterator j(base); j.has_next(); j.next()) {
1825 j.get()->dump();
1826 }
1827 }
1828 }
1829 for (UseIterator i(field); i.has_next(); i.next()) {
1830 i.get()->dump();
1831 }
1832 assert(field->edge_count() > 0, "sanity");
1833 }
1834 }
1835 }
1836 }
1837 #endif
1838
1839 // Optimize ideal graph.
1840 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1841 GrowableArray<Node*>& storestore_worklist) {
1842 Compile* C = _compile;
1843 PhaseIterGVN* igvn = _igvn;
1844 if (EliminateLocks) {
1845 // Mark locks before changing ideal graph.
1846 int cnt = C->macro_count();
1847 for( int i=0; i < cnt; i++ ) {
1848 Node *n = C->macro_node(i);
1849 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1850 AbstractLockNode* alock = n->as_AbstractLock();
1851 if (!alock->is_non_esc_obj()) {
1852 if (not_global_escape(alock->obj_node())) {
1853 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1854 // The lock could be marked eliminated by lock coarsening
1855 // code during first IGVN before EA. Replace coarsened flag
1856 // to eliminate all associated locks/unlocks.
1857 #ifdef ASSERT
1858 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1859 #endif
1860 alock->set_non_esc_obj();
1861 }
1862 }
1863 }
1864 }
1865 }
1866
1867 if (OptimizePtrCompare) {
1868 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1869 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1870 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1871 // Optimize objects compare.
1872 while (ptr_cmp_worklist.length() != 0) {
1873 Node *n = ptr_cmp_worklist.pop();
1874 Node *res = optimize_ptr_compare(n);
1875 if (res != NULL) {
1876 #ifndef PRODUCT
1877 if (PrintOptimizePtrCompare) {
1878 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"));
1879 if (Verbose) {
1880 n->dump(1);
1881 }
1882 }
1883 #endif
1884 igvn->replace_node(n, res);
1885 }
1886 }
1887 // cleanup
1888 if (_pcmp_neq->outcnt() == 0)
1889 igvn->hash_delete(_pcmp_neq);
1890 if (_pcmp_eq->outcnt() == 0)
1891 igvn->hash_delete(_pcmp_eq);
1892 }
1893
1894 // For MemBarStoreStore nodes added in library_call.cpp, check
1895 // escape status of associated AllocateNode and optimize out
1896 // MemBarStoreStore node if the allocated object never escapes.
1897 while (storestore_worklist.length() != 0) {
1898 Node *n = storestore_worklist.pop();
1899 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1900 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1901 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1902 if (not_global_escape(alloc)) {
1903 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1904 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1905 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1906 igvn->register_new_node_with_optimizer(mb);
1907 igvn->replace_node(storestore, mb);
1908 }
1909 }
1910 }
1911
1912 // Optimize objects compare.
1913 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1914 assert(OptimizePtrCompare, "sanity");
1915 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1916 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1917 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1918 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1919 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1920 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1921
1922 // Check simple cases first.
1923 if (jobj1 != NULL) {
1924 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1925 if (jobj1 == jobj2) {
1926 // Comparing the same not escaping object.
1927 return _pcmp_eq;
1928 }
1929 Node* obj = jobj1->ideal_node();
1930 // Comparing not escaping allocation.
1931 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1932 !ptn2->points_to(jobj1)) {
1933 return _pcmp_neq; // This includes nullness check.
1934 }
1935 }
1936 }
1937 if (jobj2 != NULL) {
1938 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1939 Node* obj = jobj2->ideal_node();
1940 // Comparing not escaping allocation.
1941 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1942 !ptn1->points_to(jobj2)) {
1943 return _pcmp_neq; // This includes nullness check.
1944 }
1945 }
1946 }
1947 if (jobj1 != NULL && jobj1 != phantom_obj &&
1948 jobj2 != NULL && jobj2 != phantom_obj &&
1949 jobj1->ideal_node()->is_Con() &&
1950 jobj2->ideal_node()->is_Con()) {
1951 // Klass or String constants compare. Need to be careful with
1952 // compressed pointers - compare types of ConN and ConP instead of nodes.
1953 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1954 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1955 if (t1->make_ptr() == t2->make_ptr()) {
1956 return _pcmp_eq;
1957 } else {
1958 return _pcmp_neq;
1959 }
1960 }
1961 if (ptn1->meet(ptn2)) {
1962 return NULL; // Sets are not disjoint
1963 }
1964
1965 // Sets are disjoint.
1966 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1967 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1968 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1969 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1970 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
1971 (set2_has_unknown_ptr && set1_has_null_ptr)) {
1972 // Check nullness of unknown object.
1973 return NULL;
1974 }
1975
1976 // Disjointness by itself is not sufficient since
1977 // alias analysis is not complete for escaped objects.
1978 // Disjoint sets are definitely unrelated only when
1979 // at least one set has only not escaping allocations.
1980 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1981 if (ptn1->non_escaping_allocation()) {
1982 return _pcmp_neq;
1983 }
1984 }
1985 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1986 if (ptn2->non_escaping_allocation()) {
1987 return _pcmp_neq;
1988 }
1989 }
1990 return NULL;
1991 }
1992
1993 // Connection Graph constuction functions.
1994
1995 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1996 PointsToNode* ptadr = _nodes.at(n->_idx);
1997 if (ptadr != NULL) {
1998 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1999 return;
2000 }
2001 Compile* C = _compile;
2002 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2003 _nodes.at_put(n->_idx, ptadr);
2004 }
2005
2006 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2007 PointsToNode* ptadr = _nodes.at(n->_idx);
2008 if (ptadr != NULL) {
2009 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2010 return;
2011 }
2012 Compile* C = _compile;
2013 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2014 _nodes.at_put(n->_idx, ptadr);
2015 }
2016
2017 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2018 PointsToNode* ptadr = _nodes.at(n->_idx);
2019 if (ptadr != NULL) {
2020 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2021 return;
2022 }
2023 bool unsafe = false;
2024 bool is_oop = is_oop_field(n, offset, &unsafe);
2025 if (unsafe) {
2026 es = PointsToNode::GlobalEscape;
2027 }
2028 Compile* C = _compile;
2029 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2030 _nodes.at_put(n->_idx, field);
2031 }
2032
2033 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2034 PointsToNode* src, PointsToNode* dst) {
2035 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2036 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2037 PointsToNode* ptadr = _nodes.at(n->_idx);
2038 if (ptadr != NULL) {
2039 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2040 return;
2041 }
2042 Compile* C = _compile;
2043 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2044 _nodes.at_put(n->_idx, ptadr);
2045 // Add edge from arraycopy node to source object.
2046 (void)add_edge(ptadr, src);
2047 src->set_arraycopy_src();
2048 // Add edge from destination object to arraycopy node.
2049 (void)add_edge(dst, ptadr);
2050 dst->set_arraycopy_dst();
2051 }
2052
2053 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2054 const Type* adr_type = n->as_AddP()->bottom_type();
2055 BasicType bt = T_INT;
2056 if (offset == Type::OffsetBot) {
2057 // Check only oop fields.
2058 if (!adr_type->isa_aryptr() ||
2059 (adr_type->isa_aryptr()->klass() == NULL) ||
2060 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2061 // OffsetBot is used to reference array's element. Ignore first AddP.
2062 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2063 bt = T_OBJECT;
2064 }
2065 }
2066 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2067 if (adr_type->isa_instptr()) {
2068 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2069 if (field != NULL) {
2070 bt = field->layout_type();
2071 } else {
2072 // Check for unsafe oop field access
2073 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2074 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2075 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2076 bt = T_OBJECT;
2077 (*unsafe) = true;
2078 }
2079 }
2080 } else if (adr_type->isa_aryptr()) {
2081 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2082 // Ignore array length load.
2083 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2084 // Ignore first AddP.
2085 } else {
2086 const Type* elemtype = adr_type->isa_aryptr()->elem();
2087 bt = elemtype->array_element_basic_type();
2088 }
2089 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2090 // Allocation initialization, ThreadLocal field access, unsafe access
2091 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2092 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2093 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2094 bt = T_OBJECT;
2095 }
2096 }
2097 }
2098 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2099 }
2100
2101 // Returns unique pointed java object or NULL.
2102 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2103 assert(!_collecting, "should not call when contructed graph");
2104 // If the node was created after the escape computation we can't answer.
2105 uint idx = n->_idx;
2106 if (idx >= nodes_size()) {
2107 return NULL;
2108 }
2109 PointsToNode* ptn = ptnode_adr(idx);
2110 if (ptn->is_JavaObject()) {
2111 return ptn->as_JavaObject();
2112 }
2113 assert(ptn->is_LocalVar(), "sanity");
2114 // Check all java objects it points to.
2115 JavaObjectNode* jobj = NULL;
2116 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2117 PointsToNode* e = i.get();
2118 if (e->is_JavaObject()) {
2119 if (jobj == NULL) {
2120 jobj = e->as_JavaObject();
2121 } else if (jobj != e) {
2122 return NULL;
2123 }
2124 }
2125 }
2126 return jobj;
2127 }
2128
2129 // Return true if this node points only to non-escaping allocations.
2130 bool PointsToNode::non_escaping_allocation() {
2131 if (is_JavaObject()) {
2132 Node* n = ideal_node();
2133 if (n->is_Allocate() || n->is_CallStaticJava()) {
2134 return (escape_state() == PointsToNode::NoEscape);
2135 } else {
2136 return false;
2137 }
2138 }
2139 assert(is_LocalVar(), "sanity");
2140 // Check all java objects it points to.
2141 for (EdgeIterator i(this); i.has_next(); i.next()) {
2142 PointsToNode* e = i.get();
2143 if (e->is_JavaObject()) {
2144 Node* n = e->ideal_node();
2145 if ((e->escape_state() != PointsToNode::NoEscape) ||
2146 !(n->is_Allocate() || n->is_CallStaticJava())) {
2147 return false;
2148 }
2149 }
2150 }
2151 return true;
2152 }
2153
2154 // Return true if we know the node does not escape globally.
2155 bool ConnectionGraph::not_global_escape(Node *n) {
2156 assert(!_collecting, "should not call during graph construction");
2157 // If the node was created after the escape computation we can't answer.
2158 uint idx = n->_idx;
2159 if (idx >= nodes_size()) {
2160 return false;
2161 }
2162 PointsToNode* ptn = ptnode_adr(idx);
2163 PointsToNode::EscapeState es = ptn->escape_state();
2164 // If we have already computed a value, return it.
2165 if (es >= PointsToNode::GlobalEscape)
2166 return false;
2167 if (ptn->is_JavaObject()) {
2168 return true; // (es < PointsToNode::GlobalEscape);
2169 }
2170 assert(ptn->is_LocalVar(), "sanity");
2171 // Check all java objects it points to.
2172 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2173 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2174 return false;
2175 }
2176 return true;
2177 }
2178
2179
2180 // Helper functions
2181
2182 // Return true if this node points to specified node or nodes it points to.
2183 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2184 if (is_JavaObject()) {
2185 return (this == ptn);
2186 }
2187 assert(is_LocalVar() || is_Field(), "sanity");
2188 for (EdgeIterator i(this); i.has_next(); i.next()) {
2189 if (i.get() == ptn)
2190 return true;
2191 }
2192 return false;
2193 }
2194
2195 // Return true if one node points to an other.
2196 bool PointsToNode::meet(PointsToNode* ptn) {
2197 if (this == ptn) {
2198 return true;
2199 } else if (ptn->is_JavaObject()) {
2200 return this->points_to(ptn->as_JavaObject());
2201 } else if (this->is_JavaObject()) {
2202 return ptn->points_to(this->as_JavaObject());
2203 }
2204 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2205 int ptn_count = ptn->edge_count();
2206 for (EdgeIterator i(this); i.has_next(); i.next()) {
2207 PointsToNode* this_e = i.get();
2208 for (int j = 0; j < ptn_count; j++) {
2209 if (this_e == ptn->edge(j))
2210 return true;
2211 }
2212 }
2213 return false;
2214 }
2215
2216 #ifdef ASSERT
2217 // Return true if bases point to this java object.
2218 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2219 for (BaseIterator i(this); i.has_next(); i.next()) {
2220 if (i.get() == jobj)
2221 return true;
2222 }
2223 return false;
2224 }
2225 #endif
2226
2227 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2228 const Type *adr_type = phase->type(adr);
2229 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2230 adr->in(AddPNode::Address)->is_Proj() &&
2231 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2232 // We are computing a raw address for a store captured by an Initialize
2233 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2234 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2235 assert(offs != Type::OffsetBot ||
2236 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2237 "offset must be a constant or it is initialization of array");
2238 return offs;
2239 }
2240 const TypePtr *t_ptr = adr_type->isa_ptr();
2241 assert(t_ptr != NULL, "must be a pointer type");
2242 return t_ptr->offset();
2243 }
2244
2245 Node* ConnectionGraph::get_addp_base(Node *addp) {
2246 assert(addp->is_AddP(), "must be AddP");
2247 //
2248 // AddP cases for Base and Address inputs:
2249 // case #1. Direct object's field reference:
2250 // Allocate
2251 // |
2252 // Proj #5 ( oop result )
2253 // |
2254 // CheckCastPP (cast to instance type)
2255 // | |
2256 // AddP ( base == address )
2257 //
2258 // case #2. Indirect object's field reference:
2259 // Phi
2260 // |
2261 // CastPP (cast to instance type)
2262 // | |
2263 // AddP ( base == address )
2264 //
2265 // case #3. Raw object's field reference for Initialize node:
2266 // Allocate
2267 // |
2268 // Proj #5 ( oop result )
2269 // top |
2270 // \ |
2271 // AddP ( base == top )
2272 //
2273 // case #4. Array's element reference:
2274 // {CheckCastPP | CastPP}
2275 // | | |
2276 // | AddP ( array's element offset )
2277 // | |
2278 // AddP ( array's offset )
2279 //
2280 // case #5. Raw object's field reference for arraycopy stub call:
2281 // The inline_native_clone() case when the arraycopy stub is called
2282 // after the allocation before Initialize and CheckCastPP nodes.
2283 // Allocate
2284 // |
2285 // Proj #5 ( oop result )
2286 // | |
2287 // AddP ( base == address )
2288 //
2289 // case #6. Constant Pool, ThreadLocal, CastX2P or
2290 // Raw object's field reference:
2291 // {ConP, ThreadLocal, CastX2P, raw Load}
2292 // top |
2293 // \ |
2294 // AddP ( base == top )
2295 //
2296 // case #7. Klass's field reference.
2297 // LoadKlass
2298 // | |
2299 // AddP ( base == address )
2300 //
2301 // case #8. narrow Klass's field reference.
2302 // LoadNKlass
2303 // |
2304 // DecodeN
2305 // | |
2306 // AddP ( base == address )
2307 //
2308 // case #9. Mixed unsafe access
2309 // {instance}
2310 // |
2311 // CheckCastPP (raw)
2312 // top |
2313 // \ |
2314 // AddP ( base == top )
2315 //
2316 Node *base = addp->in(AddPNode::Base);
2317 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2318 base = addp->in(AddPNode::Address);
2319 while (base->is_AddP()) {
2320 // Case #6 (unsafe access) may have several chained AddP nodes.
2321 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2322 base = base->in(AddPNode::Address);
2323 }
2324 if (base->Opcode() == Op_CheckCastPP &&
2325 base->bottom_type()->isa_rawptr() &&
2326 _igvn->type(base->in(1))->isa_oopptr()) {
2327 base = base->in(1); // Case #9
2328 } else {
2329 Node* uncast_base = base->uncast();
2330 int opcode = uncast_base->Opcode();
2331 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2332 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2333 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2334 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2335 }
2336 }
2337 return base;
2338 }
2339
2340 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2341 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2342 Node* addp2 = addp->raw_out(0);
2343 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2344 addp2->in(AddPNode::Base) == n &&
2345 addp2->in(AddPNode::Address) == addp) {
2346 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2347 //
2348 // Find array's offset to push it on worklist first and
2349 // as result process an array's element offset first (pushed second)
2350 // to avoid CastPP for the array's offset.
2351 // Otherwise the inserted CastPP (LocalVar) will point to what
2352 // the AddP (Field) points to. Which would be wrong since
2353 // the algorithm expects the CastPP has the same point as
2354 // as AddP's base CheckCastPP (LocalVar).
2355 //
2356 // ArrayAllocation
2357 // |
2358 // CheckCastPP
2359 // |
2360 // memProj (from ArrayAllocation CheckCastPP)
2361 // | ||
2362 // | || Int (element index)
2363 // | || | ConI (log(element size))
2364 // | || | /
2365 // | || LShift
2366 // | || /
2367 // | AddP (array's element offset)
2368 // | |
2369 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2370 // | / /
2371 // AddP (array's offset)
2372 // |
2373 // Load/Store (memory operation on array's element)
2374 //
2375 return addp2;
2376 }
2377 return NULL;
2378 }
2379
2380 //
2381 // Adjust the type and inputs of an AddP which computes the
2382 // address of a field of an instance
2383 //
2384 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2385 PhaseGVN* igvn = _igvn;
2386 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2387 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2388 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2389 if (t == NULL) {
2390 // We are computing a raw address for a store captured by an Initialize
2391 // compute an appropriate address type (cases #3 and #5).
2392 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2393 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2394 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2395 assert(offs != Type::OffsetBot, "offset must be a constant");
2396 t = base_t->add_offset(offs)->is_oopptr();
2397 }
2398 int inst_id = base_t->instance_id();
2399 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2400 "old type must be non-instance or match new type");
2401
2402 // The type 't' could be subclass of 'base_t'.
2403 // As result t->offset() could be large then base_t's size and it will
2404 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2405 // constructor verifies correctness of the offset.
2406 //
2407 // It could happened on subclass's branch (from the type profiling
2408 // inlining) which was not eliminated during parsing since the exactness
2409 // of the allocation type was not propagated to the subclass type check.
2410 //
2411 // Or the type 't' could be not related to 'base_t' at all.
2412 // It could happened when CHA type is different from MDO type on a dead path
2413 // (for example, from instanceof check) which is not collapsed during parsing.
2414 //
2415 // Do nothing for such AddP node and don't process its users since
2416 // this code branch will go away.
2417 //
2418 if (!t->is_known_instance() &&
2419 !base_t->klass()->is_subtype_of(t->klass())) {
2420 return false; // bail out
2421 }
2422 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2423 // Do NOT remove the next line: ensure a new alias index is allocated
2424 // for the instance type. Note: C++ will not remove it since the call
2425 // has side effect.
2426 int alias_idx = _compile->get_alias_index(tinst);
2427 igvn->set_type(addp, tinst);
2428 // record the allocation in the node map
2429 set_map(addp, get_map(base->_idx));
2430 // Set addp's Base and Address to 'base'.
2431 Node *abase = addp->in(AddPNode::Base);
2432 Node *adr = addp->in(AddPNode::Address);
2433 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2434 adr->in(0)->_idx == (uint)inst_id) {
2435 // Skip AddP cases #3 and #5.
2436 } else {
2437 assert(!abase->is_top(), "sanity"); // AddP case #3
2438 if (abase != base) {
2439 igvn->hash_delete(addp);
2440 addp->set_req(AddPNode::Base, base);
2441 if (abase == adr) {
2442 addp->set_req(AddPNode::Address, base);
2443 } else {
2444 // AddP case #4 (adr is array's element offset AddP node)
2445 #ifdef ASSERT
2446 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2447 assert(adr->is_AddP() && atype != NULL &&
2448 atype->instance_id() == inst_id, "array's element offset should be processed first");
2449 #endif
2450 }
2451 igvn->hash_insert(addp);
2452 }
2453 }
2454 // Put on IGVN worklist since at least addp's type was changed above.
2455 record_for_optimizer(addp);
2456 return true;
2457 }
2458
2459 //
2460 // Create a new version of orig_phi if necessary. Returns either the newly
2461 // created phi or an existing phi. Sets create_new to indicate whether a new
2462 // phi was created. Cache the last newly created phi in the node map.
2463 //
2464 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2465 Compile *C = _compile;
2466 PhaseGVN* igvn = _igvn;
2467 new_created = false;
2468 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2469 // nothing to do if orig_phi is bottom memory or matches alias_idx
2470 if (phi_alias_idx == alias_idx) {
2471 return orig_phi;
2472 }
2473 // Have we recently created a Phi for this alias index?
2474 PhiNode *result = get_map_phi(orig_phi->_idx);
2475 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2476 return result;
2477 }
2478 // Previous check may fail when the same wide memory Phi was split into Phis
2479 // for different memory slices. Search all Phis for this region.
2480 if (result != NULL) {
2481 Node* region = orig_phi->in(0);
2482 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2483 Node* phi = region->fast_out(i);
2484 if (phi->is_Phi() &&
2485 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2486 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2487 return phi->as_Phi();
2488 }
2489 }
2490 }
2491 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2492 if (C->do_escape_analysis() == true && !C->failing()) {
2493 // Retry compilation without escape analysis.
2494 // If this is the first failure, the sentinel string will "stick"
2495 // to the Compile object, and the C2Compiler will see it and retry.
2496 C->record_failure(C2Compiler::retry_no_escape_analysis());
2497 }
2498 return NULL;
2499 }
2500 orig_phi_worklist.append_if_missing(orig_phi);
2501 const TypePtr *atype = C->get_adr_type(alias_idx);
2502 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2503 C->copy_node_notes_to(result, orig_phi);
2504 igvn->set_type(result, result->bottom_type());
2505 record_for_optimizer(result);
2506 set_map(orig_phi, result);
2507 new_created = true;
2508 return result;
2509 }
2510
2511 //
2512 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2513 // specified alias index.
2514 //
2515 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2516 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2517 Compile *C = _compile;
2518 PhaseGVN* igvn = _igvn;
2519 bool new_phi_created;
2520 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2521 if (!new_phi_created) {
2522 return result;
2523 }
2524 GrowableArray<PhiNode *> phi_list;
2525 GrowableArray<uint> cur_input;
2526 PhiNode *phi = orig_phi;
2527 uint idx = 1;
2528 bool finished = false;
2529 while(!finished) {
2530 while (idx < phi->req()) {
2531 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2532 if (mem != NULL && mem->is_Phi()) {
2533 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2534 if (new_phi_created) {
2535 // found an phi for which we created a new split, push current one on worklist and begin
2536 // processing new one
2537 phi_list.push(phi);
2538 cur_input.push(idx);
2539 phi = mem->as_Phi();
2540 result = newphi;
2541 idx = 1;
2542 continue;
2543 } else {
2544 mem = newphi;
2545 }
2546 }
2547 if (C->failing()) {
2548 return NULL;
2549 }
2550 result->set_req(idx++, mem);
2551 }
2552 #ifdef ASSERT
2553 // verify that the new Phi has an input for each input of the original
2554 assert( phi->req() == result->req(), "must have same number of inputs.");
2555 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2556 #endif
2557 // Check if all new phi's inputs have specified alias index.
2558 // Otherwise use old phi.
2559 for (uint i = 1; i < phi->req(); i++) {
2560 Node* in = result->in(i);
2561 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2562 }
2563 // we have finished processing a Phi, see if there are any more to do
2564 finished = (phi_list.length() == 0 );
2565 if (!finished) {
2566 phi = phi_list.pop();
2567 idx = cur_input.pop();
2568 PhiNode *prev_result = get_map_phi(phi->_idx);
2569 prev_result->set_req(idx++, result);
2570 result = prev_result;
2571 }
2572 }
2573 return result;
2574 }
2575
2576 //
2577 // The next methods are derived from methods in MemNode.
2578 //
2579 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2580 Node *mem = mmem;
2581 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2582 // means an array I have not precisely typed yet. Do not do any
2583 // alias stuff with it any time soon.
2584 if (toop->base() != Type::AnyPtr &&
2585 !(toop->klass() != NULL &&
2586 toop->klass()->is_java_lang_Object() &&
2587 toop->offset() == Type::OffsetBot)) {
2588 mem = mmem->memory_at(alias_idx);
2589 // Update input if it is progress over what we have now
2590 }
2591 return mem;
2592 }
2593
2594 //
2595 // Move memory users to their memory slices.
2596 //
2597 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2598 Compile* C = _compile;
2599 PhaseGVN* igvn = _igvn;
2600 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2601 assert(tp != NULL, "ptr type");
2602 int alias_idx = C->get_alias_index(tp);
2603 int general_idx = C->get_general_index(alias_idx);
2604
2605 // Move users first
2606 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2607 Node* use = n->fast_out(i);
2608 if (use->is_MergeMem()) {
2609 MergeMemNode* mmem = use->as_MergeMem();
2610 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2611 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2612 continue; // Nothing to do
2613 }
2614 // Replace previous general reference to mem node.
2615 uint orig_uniq = C->unique();
2616 Node* m = find_inst_mem(n, general_idx, orig_phis);
2617 assert(orig_uniq == C->unique(), "no new nodes");
2618 mmem->set_memory_at(general_idx, m);
2619 --imax;
2620 --i;
2621 } else if (use->is_MemBar()) {
2622 assert(!use->is_Initialize(), "initializing stores should not be moved");
2623 if (use->req() > MemBarNode::Precedent &&
2624 use->in(MemBarNode::Precedent) == n) {
2625 // Don't move related membars.
2626 record_for_optimizer(use);
2627 continue;
2628 }
2629 tp = use->as_MemBar()->adr_type()->isa_ptr();
2630 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2631 alias_idx == general_idx) {
2632 continue; // Nothing to do
2633 }
2634 // Move to general memory slice.
2635 uint orig_uniq = C->unique();
2636 Node* m = find_inst_mem(n, general_idx, orig_phis);
2637 assert(orig_uniq == C->unique(), "no new nodes");
2638 igvn->hash_delete(use);
2639 imax -= use->replace_edge(n, m);
2640 igvn->hash_insert(use);
2641 record_for_optimizer(use);
2642 --i;
2643 #ifdef ASSERT
2644 } else if (use->is_Mem()) {
2645 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2646 // Don't move related cardmark.
2647 continue;
2648 }
2649 // Memory nodes should have new memory input.
2650 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2651 assert(tp != NULL, "ptr type");
2652 int idx = C->get_alias_index(tp);
2653 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2654 "Following memory nodes should have new memory input or be on the same memory slice");
2655 } else if (use->is_Phi()) {
2656 // Phi nodes should be split and moved already.
2657 tp = use->as_Phi()->adr_type()->isa_ptr();
2658 assert(tp != NULL, "ptr type");
2659 int idx = C->get_alias_index(tp);
2660 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2661 } else {
2662 use->dump();
2663 assert(false, "should not be here");
2664 #endif
2665 }
2666 }
2667 }
2668
2669 //
2670 // Search memory chain of "mem" to find a MemNode whose address
2671 // is the specified alias index.
2672 //
2673 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2674 if (orig_mem == NULL)
2675 return orig_mem;
2676 Compile* C = _compile;
2677 PhaseGVN* igvn = _igvn;
2678 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2679 bool is_instance = (toop != NULL) && toop->is_known_instance();
2680 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2681 Node *prev = NULL;
2682 Node *result = orig_mem;
2683 while (prev != result) {
2684 prev = result;
2685 if (result == start_mem)
2686 break; // hit one of our sentinels
2687 if (result->is_Mem()) {
2688 const Type *at = igvn->type(result->in(MemNode::Address));
2689 if (at == Type::TOP)
2690 break; // Dead
2691 assert (at->isa_ptr() != NULL, "pointer type required.");
2692 int idx = C->get_alias_index(at->is_ptr());
2693 if (idx == alias_idx)
2694 break; // Found
2695 if (!is_instance && (at->isa_oopptr() == NULL ||
2696 !at->is_oopptr()->is_known_instance())) {
2697 break; // Do not skip store to general memory slice.
2698 }
2699 result = result->in(MemNode::Memory);
2700 }
2701 if (!is_instance)
2702 continue; // don't search further for non-instance types
2703 // skip over a call which does not affect this memory slice
2704 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2705 Node *proj_in = result->in(0);
2706 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2707 break; // hit one of our sentinels
2708 } else if (proj_in->is_Call()) {
2709 // ArrayCopy node processed here as well
2710 CallNode *call = proj_in->as_Call();
2711 if (!call->may_modify(toop, igvn)) {
2712 result = call->in(TypeFunc::Memory);
2713 }
2714 } else if (proj_in->is_Initialize()) {
2715 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2716 // Stop if this is the initialization for the object instance which
2717 // which contains this memory slice, otherwise skip over it.
2718 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2719 result = proj_in->in(TypeFunc::Memory);
2720 }
2721 } else if (proj_in->is_MemBar()) {
2722 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2723 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2724 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2725 // clone
2726 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2727 if (ac->may_modify(toop, igvn)) {
2728 break;
2729 }
2730 }
2731 result = proj_in->in(TypeFunc::Memory);
2732 }
2733 } else if (result->is_MergeMem()) {
2734 MergeMemNode *mmem = result->as_MergeMem();
2735 result = step_through_mergemem(mmem, alias_idx, toop);
2736 if (result == mmem->base_memory()) {
2737 // Didn't find instance memory, search through general slice recursively.
2738 result = mmem->memory_at(C->get_general_index(alias_idx));
2739 result = find_inst_mem(result, alias_idx, orig_phis);
2740 if (C->failing()) {
2741 return NULL;
2742 }
2743 mmem->set_memory_at(alias_idx, result);
2744 }
2745 } else if (result->is_Phi() &&
2746 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2747 Node *un = result->as_Phi()->unique_input(igvn);
2748 if (un != NULL) {
2749 orig_phis.append_if_missing(result->as_Phi());
2750 result = un;
2751 } else {
2752 break;
2753 }
2754 } else if (result->is_ClearArray()) {
2755 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2756 // Can not bypass initialization of the instance
2757 // we are looking for.
2758 break;
2759 }
2760 // Otherwise skip it (the call updated 'result' value).
2761 } else if (result->Opcode() == Op_SCMemProj) {
2762 Node* mem = result->in(0);
2763 Node* adr = NULL;
2764 if (mem->is_LoadStore()) {
2765 adr = mem->in(MemNode::Address);
2766 } else {
2767 assert(mem->Opcode() == Op_EncodeISOArray ||
2768 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2769 adr = mem->in(3); // Memory edge corresponds to destination array
2770 }
2771 const Type *at = igvn->type(adr);
2772 if (at != Type::TOP) {
2773 assert(at->isa_ptr() != NULL, "pointer type required.");
2774 int idx = C->get_alias_index(at->is_ptr());
2775 if (idx == alias_idx) {
2776 // Assert in debug mode
2777 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2778 break; // In product mode return SCMemProj node
2779 }
2780 }
2781 result = mem->in(MemNode::Memory);
2782 } else if (result->Opcode() == Op_StrInflatedCopy) {
2783 Node* adr = result->in(3); // Memory edge corresponds to destination array
2784 const Type *at = igvn->type(adr);
2785 if (at != Type::TOP) {
2786 assert(at->isa_ptr() != NULL, "pointer type required.");
2787 int idx = C->get_alias_index(at->is_ptr());
2788 if (idx == alias_idx) {
2789 // Assert in debug mode
2790 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2791 break; // In product mode return SCMemProj node
2792 }
2793 }
2794 result = result->in(MemNode::Memory);
2795 }
2796 }
2797 if (result->is_Phi()) {
2798 PhiNode *mphi = result->as_Phi();
2799 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2800 const TypePtr *t = mphi->adr_type();
2801 if (!is_instance) {
2802 // Push all non-instance Phis on the orig_phis worklist to update inputs
2803 // during Phase 4 if needed.
2804 orig_phis.append_if_missing(mphi);
2805 } else if (C->get_alias_index(t) != alias_idx) {
2806 // Create a new Phi with the specified alias index type.
2807 result = split_memory_phi(mphi, alias_idx, orig_phis);
2808 }
2809 }
2810 // the result is either MemNode, PhiNode, InitializeNode.
2811 return result;
2812 }
2813
2814 //
2815 // Convert the types of unescaped object to instance types where possible,
2816 // propagate the new type information through the graph, and update memory
2817 // edges and MergeMem inputs to reflect the new type.
2818 //
2819 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2820 // The processing is done in 4 phases:
2821 //
2822 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2823 // types for the CheckCastPP for allocations where possible.
2824 // Propagate the new types through users as follows:
2825 // casts and Phi: push users on alloc_worklist
2826 // AddP: cast Base and Address inputs to the instance type
2827 // push any AddP users on alloc_worklist and push any memnode
2828 // users onto memnode_worklist.
2829 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2830 // search the Memory chain for a store with the appropriate type
2831 // address type. If a Phi is found, create a new version with
2832 // the appropriate memory slices from each of the Phi inputs.
2833 // For stores, process the users as follows:
2834 // MemNode: push on memnode_worklist
2835 // MergeMem: push on mergemem_worklist
2836 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2837 // moving the first node encountered of each instance type to the
2838 // the input corresponding to its alias index.
2839 // appropriate memory slice.
2840 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2841 //
2842 // In the following example, the CheckCastPP nodes are the cast of allocation
2843 // results and the allocation of node 29 is unescaped and eligible to be an
2844 // instance type.
2845 //
2846 // We start with:
2847 //
2848 // 7 Parm #memory
2849 // 10 ConI "12"
2850 // 19 CheckCastPP "Foo"
2851 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2852 // 29 CheckCastPP "Foo"
2853 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2854 //
2855 // 40 StoreP 25 7 20 ... alias_index=4
2856 // 50 StoreP 35 40 30 ... alias_index=4
2857 // 60 StoreP 45 50 20 ... alias_index=4
2858 // 70 LoadP _ 60 30 ... alias_index=4
2859 // 80 Phi 75 50 60 Memory alias_index=4
2860 // 90 LoadP _ 80 30 ... alias_index=4
2861 // 100 LoadP _ 80 20 ... alias_index=4
2862 //
2863 //
2864 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2865 // and creating a new alias index for node 30. This gives:
2866 //
2867 // 7 Parm #memory
2868 // 10 ConI "12"
2869 // 19 CheckCastPP "Foo"
2870 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2871 // 29 CheckCastPP "Foo" iid=24
2872 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2873 //
2874 // 40 StoreP 25 7 20 ... alias_index=4
2875 // 50 StoreP 35 40 30 ... alias_index=6
2876 // 60 StoreP 45 50 20 ... alias_index=4
2877 // 70 LoadP _ 60 30 ... alias_index=6
2878 // 80 Phi 75 50 60 Memory alias_index=4
2879 // 90 LoadP _ 80 30 ... alias_index=6
2880 // 100 LoadP _ 80 20 ... alias_index=4
2881 //
2882 // In phase 2, new memory inputs are computed for the loads and stores,
2883 // And a new version of the phi is created. In phase 4, the inputs to
2884 // node 80 are updated and then the memory nodes are updated with the
2885 // values computed in phase 2. This results in:
2886 //
2887 // 7 Parm #memory
2888 // 10 ConI "12"
2889 // 19 CheckCastPP "Foo"
2890 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2891 // 29 CheckCastPP "Foo" iid=24
2892 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2893 //
2894 // 40 StoreP 25 7 20 ... alias_index=4
2895 // 50 StoreP 35 7 30 ... alias_index=6
2896 // 60 StoreP 45 40 20 ... alias_index=4
2897 // 70 LoadP _ 50 30 ... alias_index=6
2898 // 80 Phi 75 40 60 Memory alias_index=4
2899 // 120 Phi 75 50 50 Memory alias_index=6
2900 // 90 LoadP _ 120 30 ... alias_index=6
2901 // 100 LoadP _ 80 20 ... alias_index=4
2902 //
2903 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2904 GrowableArray<Node *> memnode_worklist;
2905 GrowableArray<PhiNode *> orig_phis;
2906 PhaseIterGVN *igvn = _igvn;
2907 uint new_index_start = (uint) _compile->num_alias_types();
2908 Arena* arena = Thread::current()->resource_area();
2909 VectorSet visited(arena);
2910 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2911 uint unique_old = _compile->unique();
2912
2913 // Phase 1: Process possible allocations from alloc_worklist.
2914 // Create instance types for the CheckCastPP for allocations where possible.
2915 //
2916 // (Note: don't forget to change the order of the second AddP node on
2917 // the alloc_worklist if the order of the worklist processing is changed,
2918 // see the comment in find_second_addp().)
2919 //
2920 while (alloc_worklist.length() != 0) {
2921 Node *n = alloc_worklist.pop();
2922 uint ni = n->_idx;
2923 if (n->is_Call()) {
2924 CallNode *alloc = n->as_Call();
2925 // copy escape information to call node
2926 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2927 PointsToNode::EscapeState es = ptn->escape_state();
2928 // We have an allocation or call which returns a Java object,
2929 // see if it is unescaped.
2930 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2931 continue;
2932 // Find CheckCastPP for the allocate or for the return value of a call
2933 n = alloc->result_cast();
2934 if (n == NULL) { // No uses except Initialize node
2935 if (alloc->is_Allocate()) {
2936 // Set the scalar_replaceable flag for allocation
2937 // so it could be eliminated if it has no uses.
2938 alloc->as_Allocate()->_is_scalar_replaceable = true;
2939 }
2940 if (alloc->is_CallStaticJava()) {
2941 // Set the scalar_replaceable flag for boxing method
2942 // so it could be eliminated if it has no uses.
2943 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2944 }
2945 continue;
2946 }
2947 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2948 assert(!alloc->is_Allocate(), "allocation should have unique type");
2949 continue;
2950 }
2951
2952 // The inline code for Object.clone() casts the allocation result to
2953 // java.lang.Object and then to the actual type of the allocated
2954 // object. Detect this case and use the second cast.
2955 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2956 // the allocation result is cast to java.lang.Object and then
2957 // to the actual Array type.
2958 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2959 && (alloc->is_AllocateArray() ||
2960 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2961 Node *cast2 = NULL;
2962 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2963 Node *use = n->fast_out(i);
2964 if (use->is_CheckCastPP()) {
2965 cast2 = use;
2966 break;
2967 }
2968 }
2969 if (cast2 != NULL) {
2970 n = cast2;
2971 } else {
2972 // Non-scalar replaceable if the allocation type is unknown statically
2973 // (reflection allocation), the object can't be restored during
2974 // deoptimization without precise type.
2975 continue;
2976 }
2977 }
2978
2979 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2980 if (t == NULL)
2981 continue; // not a TypeOopPtr
2982 if (!t->klass_is_exact())
2983 continue; // not an unique type
2984
2985 if (alloc->is_Allocate()) {
2986 // Set the scalar_replaceable flag for allocation
2987 // so it could be eliminated.
2988 alloc->as_Allocate()->_is_scalar_replaceable = true;
2989 }
2990 if (alloc->is_CallStaticJava()) {
2991 // Set the scalar_replaceable flag for boxing method
2992 // so it could be eliminated.
2993 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2994 }
2995 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2996 // in order for an object to be scalar-replaceable, it must be:
2997 // - a direct allocation (not a call returning an object)
2998 // - non-escaping
2999 // - eligible to be a unique type
3000 // - not determined to be ineligible by escape analysis
3001 set_map(alloc, n);
3002 set_map(n, alloc);
3003 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3004 igvn->hash_delete(n);
3005 igvn->set_type(n, tinst);
3006 n->raise_bottom_type(tinst);
3007 igvn->hash_insert(n);
3008 record_for_optimizer(n);
3009 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3010
3011 // First, put on the worklist all Field edges from Connection Graph
3012 // which is more accurate than putting immediate users from Ideal Graph.
3013 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3014 PointsToNode* tgt = e.get();
3015 if (tgt->is_Arraycopy()) {
3016 continue;
3017 }
3018 Node* use = tgt->ideal_node();
3019 assert(tgt->is_Field() && use->is_AddP(),
3020 "only AddP nodes are Field edges in CG");
3021 if (use->outcnt() > 0) { // Don't process dead nodes
3022 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3023 if (addp2 != NULL) {
3024 assert(alloc->is_AllocateArray(),"array allocation was expected");
3025 alloc_worklist.append_if_missing(addp2);
3026 }
3027 alloc_worklist.append_if_missing(use);
3028 }
3029 }
3030
3031 // An allocation may have an Initialize which has raw stores. Scan
3032 // the users of the raw allocation result and push AddP users
3033 // on alloc_worklist.
3034 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3035 assert (raw_result != NULL, "must have an allocation result");
3036 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3037 Node *use = raw_result->fast_out(i);
3038 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3039 Node* addp2 = find_second_addp(use, raw_result);
3040 if (addp2 != NULL) {
3041 assert(alloc->is_AllocateArray(),"array allocation was expected");
3042 alloc_worklist.append_if_missing(addp2);
3043 }
3044 alloc_worklist.append_if_missing(use);
3045 } else if (use->is_MemBar()) {
3046 memnode_worklist.append_if_missing(use);
3047 }
3048 }
3049 }
3050 } else if (n->is_AddP()) {
3051 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3052 if (jobj == NULL || jobj == phantom_obj) {
3053 #ifdef ASSERT
3054 ptnode_adr(get_addp_base(n)->_idx)->dump();
3055 ptnode_adr(n->_idx)->dump();
3056 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3057 #endif
3058 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3059 return;
3060 }
3061 Node *base = get_map(jobj->idx()); // CheckCastPP node
3062 if (!split_AddP(n, base)) continue; // wrong type from dead path
3063 } else if (n->is_Phi() ||
3064 n->is_CheckCastPP() ||
3065 n->is_EncodeP() ||
3066 n->is_DecodeN() ||
3067 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3068 if (visited.test_set(n->_idx)) {
3069 assert(n->is_Phi(), "loops only through Phi's");
3070 continue; // already processed
3071 }
3072 JavaObjectNode* jobj = unique_java_object(n);
3073 if (jobj == NULL || jobj == phantom_obj) {
3074 #ifdef ASSERT
3075 ptnode_adr(n->_idx)->dump();
3076 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3077 #endif
3078 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3079 return;
3080 } else {
3081 Node *val = get_map(jobj->idx()); // CheckCastPP node
3082 TypeNode *tn = n->as_Type();
3083 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3084 assert(tinst != NULL && tinst->is_known_instance() &&
3085 tinst->instance_id() == jobj->idx() , "instance type expected.");
3086
3087 const Type *tn_type = igvn->type(tn);
3088 const TypeOopPtr *tn_t;
3089 if (tn_type->isa_narrowoop()) {
3090 tn_t = tn_type->make_ptr()->isa_oopptr();
3091 } else {
3092 tn_t = tn_type->isa_oopptr();
3093 }
3094 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3095 if (tn_type->isa_narrowoop()) {
3096 tn_type = tinst->make_narrowoop();
3097 } else {
3098 tn_type = tinst;
3099 }
3100 igvn->hash_delete(tn);
3101 igvn->set_type(tn, tn_type);
3102 tn->set_type(tn_type);
3103 igvn->hash_insert(tn);
3104 record_for_optimizer(n);
3105 } else {
3106 assert(tn_type == TypePtr::NULL_PTR ||
3107 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3108 "unexpected type");
3109 continue; // Skip dead path with different type
3110 }
3111 }
3112 } else {
3113 debug_only(n->dump();)
3114 assert(false, "EA: unexpected node");
3115 continue;
3116 }
3117 // push allocation's users on appropriate worklist
3118 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3119 Node *use = n->fast_out(i);
3120 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3121 // Load/store to instance's field
3122 memnode_worklist.append_if_missing(use);
3123 } else if (use->is_MemBar()) {
3124 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3125 memnode_worklist.append_if_missing(use);
3126 }
3127 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3128 Node* addp2 = find_second_addp(use, n);
3129 if (addp2 != NULL) {
3130 alloc_worklist.append_if_missing(addp2);
3131 }
3132 alloc_worklist.append_if_missing(use);
3133 } else if (use->is_Phi() ||
3134 use->is_CheckCastPP() ||
3135 use->is_EncodeNarrowPtr() ||
3136 use->is_DecodeNarrowPtr() ||
3137 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3138 alloc_worklist.append_if_missing(use);
3139 #ifdef ASSERT
3140 } else if (use->is_Mem()) {
3141 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3142 } else if (use->is_MergeMem()) {
3143 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3144 } else if (use->is_SafePoint()) {
3145 // Look for MergeMem nodes for calls which reference unique allocation
3146 // (through CheckCastPP nodes) even for debug info.
3147 Node* m = use->in(TypeFunc::Memory);
3148 if (m->is_MergeMem()) {
3149 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3150 }
3151 } else if (use->Opcode() == Op_EncodeISOArray) {
3152 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3153 // EncodeISOArray overwrites destination array
3154 memnode_worklist.append_if_missing(use);
3155 }
3156 } else {
3157 uint op = use->Opcode();
3158 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3159 (use->in(MemNode::Memory) == n)) {
3160 // They overwrite memory edge corresponding to destination array,
3161 memnode_worklist.append_if_missing(use);
3162 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3163 op == Op_CastP2X || op == Op_StoreCM ||
3164 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3165 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3166 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3167 n->dump();
3168 use->dump();
3169 assert(false, "EA: missing allocation reference path");
3170 }
3171 #endif
3172 }
3173 }
3174
3175 }
3176
3177 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3178 // type, record it in the ArrayCopy node so we know what memory this
3179 // node uses/modified.
3180 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3181 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3182 Node* dest = ac->in(ArrayCopyNode::Dest);
3183 if (dest->is_AddP()) {
3184 dest = get_addp_base(dest);
3185 }
3186 JavaObjectNode* jobj = unique_java_object(dest);
3187 if (jobj != NULL) {
3188 Node *base = get_map(jobj->idx());
3189 if (base != NULL) {
3190 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3191 ac->_dest_type = base_t;
3192 }
3193 }
3194 Node* src = ac->in(ArrayCopyNode::Src);
3195 if (src->is_AddP()) {
3196 src = get_addp_base(src);
3197 }
3198 jobj = unique_java_object(src);
3199 if (jobj != NULL) {
3200 Node* base = get_map(jobj->idx());
3201 if (base != NULL) {
3202 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3203 ac->_src_type = base_t;
3204 }
3205 }
3206 }
3207
3208 // New alias types were created in split_AddP().
3209 uint new_index_end = (uint) _compile->num_alias_types();
3210 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3211
3212 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3213 // compute new values for Memory inputs (the Memory inputs are not
3214 // actually updated until phase 4.)
3215 if (memnode_worklist.length() == 0)
3216 return; // nothing to do
3217 while (memnode_worklist.length() != 0) {
3218 Node *n = memnode_worklist.pop();
3219 if (visited.test_set(n->_idx))
3220 continue;
3221 if (n->is_Phi() || n->is_ClearArray()) {
3222 // we don't need to do anything, but the users must be pushed
3223 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3224 // we don't need to do anything, but the users must be pushed
3225 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3226 if (n == NULL)
3227 continue;
3228 } else if (n->Opcode() == Op_StrCompressedCopy ||
3229 n->Opcode() == Op_EncodeISOArray) {
3230 // get the memory projection
3231 n = n->find_out_with(Op_SCMemProj);
3232 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3233 } else {
3234 assert(n->is_Mem(), "memory node required.");
3235 Node *addr = n->in(MemNode::Address);
3236 const Type *addr_t = igvn->type(addr);
3237 if (addr_t == Type::TOP)
3238 continue;
3239 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3240 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3241 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3242 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3243 if (_compile->failing()) {
3244 return;
3245 }
3246 if (mem != n->in(MemNode::Memory)) {
3247 // We delay the memory edge update since we need old one in
3248 // MergeMem code below when instances memory slices are separated.
3249 set_map(n, mem);
3250 }
3251 if (n->is_Load()) {
3252 continue; // don't push users
3253 } else if (n->is_LoadStore()) {
3254 // get the memory projection
3255 n = n->find_out_with(Op_SCMemProj);
3256 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3257 }
3258 }
3259 // push user on appropriate worklist
3260 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3261 Node *use = n->fast_out(i);
3262 if (use->is_Phi() || use->is_ClearArray()) {
3263 memnode_worklist.append_if_missing(use);
3264 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3265 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3266 continue;
3267 memnode_worklist.append_if_missing(use);
3268 } else if (use->is_MemBar()) {
3269 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3270 memnode_worklist.append_if_missing(use);
3271 }
3272 #ifdef ASSERT
3273 } else if(use->is_Mem()) {
3274 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3275 } else if (use->is_MergeMem()) {
3276 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3277 } else if (use->Opcode() == Op_EncodeISOArray) {
3278 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3279 // EncodeISOArray overwrites destination array
3280 memnode_worklist.append_if_missing(use);
3281 }
3282 } else {
3283 uint op = use->Opcode();
3284 if ((use->in(MemNode::Memory) == n) &&
3285 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3286 // They overwrite memory edge corresponding to destination array,
3287 memnode_worklist.append_if_missing(use);
3288 } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
3289 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3290 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3291 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3292 n->dump();
3293 use->dump();
3294 assert(false, "EA: missing memory path");
3295 }
3296 #endif
3297 }
3298 }
3299 }
3300
3301 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3302 // Walk each memory slice moving the first node encountered of each
3303 // instance type to the the input corresponding to its alias index.
3304 uint length = _mergemem_worklist.length();
3305 for( uint next = 0; next < length; ++next ) {
3306 MergeMemNode* nmm = _mergemem_worklist.at(next);
3307 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3308 // Note: we don't want to use MergeMemStream here because we only want to
3309 // scan inputs which exist at the start, not ones we add during processing.
3310 // Note 2: MergeMem may already contains instance memory slices added
3311 // during find_inst_mem() call when memory nodes were processed above.
3312 igvn->hash_delete(nmm);
3313 uint nslices = MIN2(nmm->req(), new_index_start);
3314 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3315 Node* mem = nmm->in(i);
3316 Node* cur = NULL;
3317 if (mem == NULL || mem->is_top())
3318 continue;
3319 // First, update mergemem by moving memory nodes to corresponding slices
3320 // if their type became more precise since this mergemem was created.
3321 while (mem->is_Mem()) {
3322 const Type *at = igvn->type(mem->in(MemNode::Address));
3323 if (at != Type::TOP) {
3324 assert (at->isa_ptr() != NULL, "pointer type required.");
3325 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3326 if (idx == i) {
3327 if (cur == NULL)
3328 cur = mem;
3329 } else {
3330 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3331 nmm->set_memory_at(idx, mem);
3332 }
3333 }
3334 }
3335 mem = mem->in(MemNode::Memory);
3336 }
3337 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3338 // Find any instance of the current type if we haven't encountered
3339 // already a memory slice of the instance along the memory chain.
3340 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3341 if((uint)_compile->get_general_index(ni) == i) {
3342 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3343 if (nmm->is_empty_memory(m)) {
3344 Node* result = find_inst_mem(mem, ni, orig_phis);
3345 if (_compile->failing()) {
3346 return;
3347 }
3348 nmm->set_memory_at(ni, result);
3349 }
3350 }
3351 }
3352 }
3353 // Find the rest of instances values
3354 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3355 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3356 Node* result = step_through_mergemem(nmm, ni, tinst);
3357 if (result == nmm->base_memory()) {
3358 // Didn't find instance memory, search through general slice recursively.
3359 result = nmm->memory_at(_compile->get_general_index(ni));
3360 result = find_inst_mem(result, ni, orig_phis);
3361 if (_compile->failing()) {
3362 return;
3363 }
3364 nmm->set_memory_at(ni, result);
3365 }
3366 }
3367 igvn->hash_insert(nmm);
3368 record_for_optimizer(nmm);
3369 }
3370
3371 // Phase 4: Update the inputs of non-instance memory Phis and
3372 // the Memory input of memnodes
3373 // First update the inputs of any non-instance Phi's from
3374 // which we split out an instance Phi. Note we don't have
3375 // to recursively process Phi's encounted on the input memory
3376 // chains as is done in split_memory_phi() since they will
3377 // also be processed here.
3378 for (int j = 0; j < orig_phis.length(); j++) {
3379 PhiNode *phi = orig_phis.at(j);
3380 int alias_idx = _compile->get_alias_index(phi->adr_type());
3381 igvn->hash_delete(phi);
3382 for (uint i = 1; i < phi->req(); i++) {
3383 Node *mem = phi->in(i);
3384 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3385 if (_compile->failing()) {
3386 return;
3387 }
3388 if (mem != new_mem) {
3389 phi->set_req(i, new_mem);
3390 }
3391 }
3392 igvn->hash_insert(phi);
3393 record_for_optimizer(phi);
3394 }
3395
3396 // Update the memory inputs of MemNodes with the value we computed
3397 // in Phase 2 and move stores memory users to corresponding memory slices.
3398 // Disable memory split verification code until the fix for 6984348.
3399 // Currently it produces false negative results since it does not cover all cases.
3400 #if 0 // ifdef ASSERT
3401 visited.Reset();
3402 Node_Stack old_mems(arena, _compile->unique() >> 2);
3403 #endif
3404 for (uint i = 0; i < ideal_nodes.size(); i++) {
3405 Node* n = ideal_nodes.at(i);
3406 Node* nmem = get_map(n->_idx);
3407 assert(nmem != NULL, "sanity");
3408 if (n->is_Mem()) {
3409 #if 0 // ifdef ASSERT
3410 Node* old_mem = n->in(MemNode::Memory);
3411 if (!visited.test_set(old_mem->_idx)) {
3412 old_mems.push(old_mem, old_mem->outcnt());
3413 }
3414 #endif
3415 assert(n->in(MemNode::Memory) != nmem, "sanity");
3416 if (!n->is_Load()) {
3417 // Move memory users of a store first.
3418 move_inst_mem(n, orig_phis);
3419 }
3420 // Now update memory input
3421 igvn->hash_delete(n);
3422 n->set_req(MemNode::Memory, nmem);
3423 igvn->hash_insert(n);
3424 record_for_optimizer(n);
3425 } else {
3426 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3427 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3428 }
3429 }
3430 #if 0 // ifdef ASSERT
3431 // Verify that memory was split correctly
3432 while (old_mems.is_nonempty()) {
3433 Node* old_mem = old_mems.node();
3434 uint old_cnt = old_mems.index();
3435 old_mems.pop();
3436 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3437 }
3438 #endif
3439 }
3440
3441 #ifndef PRODUCT
3442 static const char *node_type_names[] = {
3443 "UnknownType",
3444 "JavaObject",
3445 "LocalVar",
3446 "Field",
3447 "Arraycopy"
3448 };
3449
3450 static const char *esc_names[] = {
3451 "UnknownEscape",
3452 "NoEscape",
3453 "ArgEscape",
3454 "GlobalEscape"
3455 };
3456
3457 void PointsToNode::dump(bool print_state) const {
3458 NodeType nt = node_type();
3459 tty->print("%s ", node_type_names[(int) nt]);
3460 if (print_state) {
3461 EscapeState es = escape_state();
3462 EscapeState fields_es = fields_escape_state();
3463 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3464 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3465 tty->print("NSR ");
3466 }
3467 if (is_Field()) {
3468 FieldNode* f = (FieldNode*)this;
3469 if (f->is_oop())
3470 tty->print("oop ");
3471 if (f->offset() > 0)
3472 tty->print("+%d ", f->offset());
3473 tty->print("(");
3474 for (BaseIterator i(f); i.has_next(); i.next()) {
3475 PointsToNode* b = i.get();
3476 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3477 }
3478 tty->print(" )");
3479 }
3480 tty->print("[");
3481 for (EdgeIterator i(this); i.has_next(); i.next()) {
3482 PointsToNode* e = i.get();
3483 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3484 }
3485 tty->print(" [");
3486 for (UseIterator i(this); i.has_next(); i.next()) {
3487 PointsToNode* u = i.get();
3488 bool is_base = false;
3489 if (PointsToNode::is_base_use(u)) {
3490 is_base = true;
3491 u = PointsToNode::get_use_node(u)->as_Field();
3492 }
3493 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3494 }
3495 tty->print(" ]] ");
3496 if (_node == NULL)
3497 tty->print_cr("<null>");
3498 else
3499 _node->dump();
3500 }
3501
3502 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3503 bool first = true;
3504 int ptnodes_length = ptnodes_worklist.length();
3505 for (int i = 0; i < ptnodes_length; i++) {
3506 PointsToNode *ptn = ptnodes_worklist.at(i);
3507 if (ptn == NULL || !ptn->is_JavaObject())
3508 continue;
3509 PointsToNode::EscapeState es = ptn->escape_state();
3510 if ((es != PointsToNode::NoEscape) && !Verbose) {
3511 continue;
3512 }
3513 Node* n = ptn->ideal_node();
3514 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3515 n->as_CallStaticJava()->is_boxing_method())) {
3516 if (first) {
3517 tty->cr();
3518 tty->print("======== Connection graph for ");
3519 _compile->method()->print_short_name();
3520 tty->cr();
3521 first = false;
3522 }
3523 ptn->dump();
3524 // Print all locals and fields which reference this allocation
3525 for (UseIterator j(ptn); j.has_next(); j.next()) {
3526 PointsToNode* use = j.get();
3527 if (use->is_LocalVar()) {
3528 use->dump(Verbose);
3529 } else if (Verbose) {
3530 use->dump();
3531 }
3532 }
3533 tty->cr();
3534 }
3535 }
3536 }
3537 #endif