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 "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/c2compiler.hpp"
32 #include "opto/arraycopynode.hpp"
33 #include "opto/callnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/compile.hpp"
36 #include "opto/escape.hpp"
37 #include "opto/phaseX.hpp"
38 #include "opto/movenode.hpp"
39 #include "opto/rootnode.hpp"
40 #if INCLUDE_ALL_GCS
41 #include "gc/g1/g1ThreadLocalData.hpp"
42 #endif // INCLUDE_ALL_GCS
43
44 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
45 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
46 _in_worklist(C->comp_arena()),
47 _next_pidx(0),
48 _collecting(true),
49 _verify(false),
50 _compile(C),
51 _igvn(igvn),
52 _node_map(C->comp_arena()) {
53 // Add unknown java object.
54 add_java_object(C->top(), PointsToNode::GlobalEscape);
55 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
56 // Add ConP(#NULL) and ConN(#NULL) nodes.
57 Node* oop_null = igvn->zerocon(T_OBJECT);
58 assert(oop_null->_idx < nodes_size(), "should be created already");
59 add_java_object(oop_null, PointsToNode::NoEscape);
60 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
61 if (UseCompressedOops) {
62 Node* noop_null = igvn->zerocon(T_NARROWOOP);
63 assert(noop_null->_idx < nodes_size(), "should be created already");
64 map_ideal_node(noop_null, null_obj);
65 }
66 _pcmp_neq = NULL; // Should be initialized
67 _pcmp_eq = NULL;
68 }
69
70 bool ConnectionGraph::has_candidates(Compile *C) {
71 // EA brings benefits only when the code has allocations and/or locks which
72 // are represented by ideal Macro nodes.
73 int cnt = C->macro_count();
74 for (int i = 0; i < cnt; i++) {
75 Node *n = C->macro_node(i);
76 if (n->is_Allocate())
77 return true;
78 if (n->is_Lock()) {
79 Node* obj = n->as_Lock()->obj_node()->uncast();
80 if (!(obj->is_Parm() || obj->is_Con()))
81 return true;
82 }
83 if (n->is_CallStaticJava() &&
84 n->as_CallStaticJava()->is_boxing_method()) {
85 return true;
86 }
87 }
88 return false;
89 }
90
91 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
92 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
93 ResourceMark rm;
94
95 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
96 // to create space for them in ConnectionGraph::_nodes[].
97 Node* oop_null = igvn->zerocon(T_OBJECT);
98 Node* noop_null = igvn->zerocon(T_NARROWOOP);
99 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
100 // Perform escape analysis
101 if (congraph->compute_escape()) {
102 // There are non escaping objects.
103 C->set_congraph(congraph);
104 }
105 // Cleanup.
106 if (oop_null->outcnt() == 0)
107 igvn->hash_delete(oop_null);
108 if (noop_null->outcnt() == 0)
109 igvn->hash_delete(noop_null);
110 }
111
112 bool ConnectionGraph::compute_escape() {
113 Compile* C = _compile;
114 PhaseGVN* igvn = _igvn;
115
116 // Worklists used by EA.
117 Unique_Node_List delayed_worklist;
118 GrowableArray<Node*> alloc_worklist;
119 GrowableArray<Node*> ptr_cmp_worklist;
120 GrowableArray<Node*> storestore_worklist;
121 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
122 GrowableArray<PointsToNode*> ptnodes_worklist;
123 GrowableArray<JavaObjectNode*> java_objects_worklist;
124 GrowableArray<JavaObjectNode*> non_escaped_worklist;
125 GrowableArray<FieldNode*> oop_fields_worklist;
126 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
127
128 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
129
130 // 1. Populate Connection Graph (CG) with PointsTo nodes.
131 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
132 // Initialize worklist
133 if (C->root() != NULL) {
134 ideal_nodes.push(C->root());
135 }
136 // Processed ideal nodes are unique on ideal_nodes list
137 // but several ideal nodes are mapped to the phantom_obj.
138 // To avoid duplicated entries on the following worklists
139 // add the phantom_obj only once to them.
140 ptnodes_worklist.append(phantom_obj);
141 java_objects_worklist.append(phantom_obj);
142 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
143 Node* n = ideal_nodes.at(next);
144 // Create PointsTo nodes and add them to Connection Graph. Called
145 // only once per ideal node since ideal_nodes is Unique_Node list.
146 add_node_to_connection_graph(n, &delayed_worklist);
147 PointsToNode* ptn = ptnode_adr(n->_idx);
148 if (ptn != NULL && ptn != phantom_obj) {
149 ptnodes_worklist.append(ptn);
150 if (ptn->is_JavaObject()) {
151 java_objects_worklist.append(ptn->as_JavaObject());
152 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
153 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
154 // Only allocations and java static calls results are interesting.
155 non_escaped_worklist.append(ptn->as_JavaObject());
156 }
157 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
158 oop_fields_worklist.append(ptn->as_Field());
159 }
160 }
161 if (n->is_MergeMem()) {
162 // Collect all MergeMem nodes to add memory slices for
163 // scalar replaceable objects in split_unique_types().
164 _mergemem_worklist.append(n->as_MergeMem());
165 } else if (OptimizePtrCompare && n->is_Cmp() &&
166 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
167 // Collect compare pointers nodes.
168 ptr_cmp_worklist.append(n);
169 } else if (n->is_MemBarStoreStore()) {
170 // Collect all MemBarStoreStore nodes so that depending on the
171 // escape status of the associated Allocate node some of them
172 // may be eliminated.
173 storestore_worklist.append(n);
174 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
175 (n->req() > MemBarNode::Precedent)) {
176 record_for_optimizer(n);
177 #ifdef ASSERT
178 } else if (n->is_AddP()) {
179 // Collect address nodes for graph verification.
180 addp_worklist.append(n);
181 #endif
182 } else if (n->is_ArrayCopy()) {
183 // Keep a list of ArrayCopy nodes so if one of its input is non
184 // escaping, we can record a unique type
185 arraycopy_worklist.append(n->as_ArrayCopy());
186 }
187 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
188 Node* m = n->fast_out(i); // Get user
189 ideal_nodes.push(m);
190 }
191 }
192 if (non_escaped_worklist.length() == 0) {
193 _collecting = false;
194 return false; // Nothing to do.
195 }
196 // Add final simple edges to graph.
197 while(delayed_worklist.size() > 0) {
198 Node* n = delayed_worklist.pop();
199 add_final_edges(n);
200 }
201 int ptnodes_length = ptnodes_worklist.length();
202
203 #ifdef ASSERT
204 if (VerifyConnectionGraph) {
205 // Verify that no new simple edges could be created and all
206 // local vars has edges.
207 _verify = true;
208 for (int next = 0; next < ptnodes_length; ++next) {
209 PointsToNode* ptn = ptnodes_worklist.at(next);
210 add_final_edges(ptn->ideal_node());
211 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
212 ptn->dump();
213 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
214 }
215 }
216 _verify = false;
217 }
218 #endif
219 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
220 // processing, calls to CI to resolve symbols (types, fields, methods)
221 // referenced in bytecode. During symbol resolution VM may throw
222 // an exception which CI cleans and converts to compilation failure.
223 if (C->failing()) return false;
224
225 // 2. Finish Graph construction by propagating references to all
226 // java objects through graph.
227 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
228 java_objects_worklist, oop_fields_worklist)) {
229 // All objects escaped or hit time or iterations limits.
230 _collecting = false;
231 return false;
232 }
233
234 // 3. Adjust scalar_replaceable state of nonescaping objects and push
235 // scalar replaceable allocations on alloc_worklist for processing
236 // in split_unique_types().
237 int non_escaped_length = non_escaped_worklist.length();
238 for (int next = 0; next < non_escaped_length; next++) {
239 JavaObjectNode* ptn = non_escaped_worklist.at(next);
240 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
241 Node* n = ptn->ideal_node();
242 if (n->is_Allocate()) {
243 n->as_Allocate()->_is_non_escaping = noescape;
244 }
245 if (n->is_CallStaticJava()) {
246 n->as_CallStaticJava()->_is_non_escaping = noescape;
247 }
248 if (noescape && ptn->scalar_replaceable()) {
249 adjust_scalar_replaceable_state(ptn);
250 if (ptn->scalar_replaceable()) {
251 alloc_worklist.append(ptn->ideal_node());
252 }
253 }
254 }
255
256 #ifdef ASSERT
257 if (VerifyConnectionGraph) {
258 // Verify that graph is complete - no new edges could be added or needed.
259 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
260 java_objects_worklist, addp_worklist);
261 }
262 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
263 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
264 null_obj->edge_count() == 0 &&
265 !null_obj->arraycopy_src() &&
266 !null_obj->arraycopy_dst(), "sanity");
267 #endif
268
269 _collecting = false;
270
271 } // TracePhase t3("connectionGraph")
272
273 // 4. Optimize ideal graph based on EA information.
274 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
275 if (has_non_escaping_obj) {
276 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
277 }
278
279 #ifndef PRODUCT
280 if (PrintEscapeAnalysis) {
281 dump(ptnodes_worklist); // Dump ConnectionGraph
282 }
283 #endif
284
285 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
286 #ifdef ASSERT
287 if (VerifyConnectionGraph) {
288 int alloc_length = alloc_worklist.length();
289 for (int next = 0; next < alloc_length; ++next) {
290 Node* n = alloc_worklist.at(next);
291 PointsToNode* ptn = ptnode_adr(n->_idx);
292 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
293 }
294 }
295 #endif
296
297 // 5. Separate memory graph for scalar replaceable allcations.
298 if (has_scalar_replaceable_candidates &&
299 C->AliasLevel() >= 3 && EliminateAllocations) {
300 // Now use the escape information to create unique types for
301 // scalar replaceable objects.
302 split_unique_types(alloc_worklist, arraycopy_worklist);
303 if (C->failing()) return false;
304 C->print_method(PHASE_AFTER_EA, 2);
305
306 #ifdef ASSERT
307 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
308 tty->print("=== No allocations eliminated for ");
309 C->method()->print_short_name();
310 if(!EliminateAllocations) {
311 tty->print(" since EliminateAllocations is off ===");
312 } else if(!has_scalar_replaceable_candidates) {
313 tty->print(" since there are no scalar replaceable candidates ===");
314 } else if(C->AliasLevel() < 3) {
315 tty->print(" since AliasLevel < 3 ===");
316 }
317 tty->cr();
318 #endif
319 }
320 return has_non_escaping_obj;
321 }
322
323 // Utility function for nodes that load an object
324 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
325 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
326 // ThreadLocal has RawPtr type.
327 const Type* t = _igvn->type(n);
328 if (t->make_ptr() != NULL) {
329 Node* adr = n->in(MemNode::Address);
330 #ifdef ASSERT
331 if (!adr->is_AddP()) {
332 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
333 } else {
334 assert((ptnode_adr(adr->_idx) == NULL ||
335 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
336 }
337 #endif
338 add_local_var_and_edge(n, PointsToNode::NoEscape,
339 adr, delayed_worklist);
340 }
341 }
342
343 // Populate Connection Graph with PointsTo nodes and create simple
344 // connection graph edges.
345 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
346 assert(!_verify, "this method should not be called for verification");
347 PhaseGVN* igvn = _igvn;
348 uint n_idx = n->_idx;
349 PointsToNode* n_ptn = ptnode_adr(n_idx);
350 if (n_ptn != NULL)
351 return; // No need to redefine PointsTo node during first iteration.
352
353 if (n->is_Call()) {
354 // Arguments to allocation and locking don't escape.
355 if (n->is_AbstractLock()) {
356 // Put Lock and Unlock nodes on IGVN worklist to process them during
357 // first IGVN optimization when escape information is still available.
358 record_for_optimizer(n);
359 } else if (n->is_Allocate()) {
360 add_call_node(n->as_Call());
361 record_for_optimizer(n);
362 } else {
363 if (n->is_CallStaticJava()) {
364 const char* name = n->as_CallStaticJava()->_name;
365 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
366 return; // Skip uncommon traps
367 }
368 // Don't mark as processed since call's arguments have to be processed.
369 delayed_worklist->push(n);
370 // Check if a call returns an object.
371 if ((n->as_Call()->returns_pointer() &&
372 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
373 (n->is_CallStaticJava() &&
374 n->as_CallStaticJava()->is_boxing_method())) {
375 add_call_node(n->as_Call());
376 }
377 }
378 return;
379 }
380 // Put this check here to process call arguments since some call nodes
381 // point to phantom_obj.
382 if (n_ptn == phantom_obj || n_ptn == null_obj)
383 return; // Skip predefined nodes.
384
385 int opcode = n->Opcode();
386 switch (opcode) {
387 case Op_AddP: {
388 Node* base = get_addp_base(n);
389 PointsToNode* ptn_base = ptnode_adr(base->_idx);
390 // Field nodes are created for all field types. They are used in
391 // adjust_scalar_replaceable_state() and split_unique_types().
392 // Note, non-oop fields will have only base edges in Connection
393 // Graph because such fields are not used for oop loads and stores.
394 int offset = address_offset(n, igvn);
395 add_field(n, PointsToNode::NoEscape, offset);
396 if (ptn_base == NULL) {
397 delayed_worklist->push(n); // Process it later.
398 } else {
399 n_ptn = ptnode_adr(n_idx);
400 add_base(n_ptn->as_Field(), ptn_base);
401 }
402 break;
403 }
404 case Op_CastX2P: {
405 map_ideal_node(n, phantom_obj);
406 break;
407 }
408 case Op_CastPP:
409 case Op_CheckCastPP:
410 case Op_EncodeP:
411 case Op_DecodeN:
412 case Op_EncodePKlass:
413 case Op_DecodeNKlass: {
414 add_local_var_and_edge(n, PointsToNode::NoEscape,
415 n->in(1), delayed_worklist);
416 break;
417 }
418 case Op_CMoveP: {
419 add_local_var(n, PointsToNode::NoEscape);
420 // Do not add edges during first iteration because some could be
421 // not defined yet.
422 delayed_worklist->push(n);
423 break;
424 }
425 case Op_ConP:
426 case Op_ConN:
427 case Op_ConNKlass: {
428 // assume all oop constants globally escape except for null
429 PointsToNode::EscapeState es;
430 const Type* t = igvn->type(n);
431 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
432 es = PointsToNode::NoEscape;
433 } else {
434 es = PointsToNode::GlobalEscape;
435 }
436 add_java_object(n, es);
437 break;
438 }
439 case Op_CreateEx: {
440 // assume that all exception objects globally escape
441 map_ideal_node(n, phantom_obj);
442 break;
443 }
444 case Op_LoadKlass:
445 case Op_LoadNKlass: {
446 // Unknown class is loaded
447 map_ideal_node(n, phantom_obj);
448 break;
449 }
450 case Op_LoadP:
451 case Op_LoadN:
452 case Op_LoadPLocked: {
453 add_objload_to_connection_graph(n, delayed_worklist);
454 break;
455 }
456 case Op_Parm: {
457 map_ideal_node(n, phantom_obj);
458 break;
459 }
460 case Op_PartialSubtypeCheck: {
461 // Produces Null or notNull and is used in only in CmpP so
462 // phantom_obj could be used.
463 map_ideal_node(n, phantom_obj); // Result is unknown
464 break;
465 }
466 case Op_Phi: {
467 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
468 // ThreadLocal has RawPtr type.
469 const Type* t = n->as_Phi()->type();
470 if (t->make_ptr() != NULL) {
471 add_local_var(n, PointsToNode::NoEscape);
472 // Do not add edges during first iteration because some could be
473 // not defined yet.
474 delayed_worklist->push(n);
475 }
476 break;
477 }
478 case Op_Proj: {
479 // we are only interested in the oop result projection from a call
480 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
481 n->in(0)->as_Call()->returns_pointer()) {
482 add_local_var_and_edge(n, PointsToNode::NoEscape,
483 n->in(0), delayed_worklist);
484 }
485 break;
486 }
487 case Op_Rethrow: // Exception object escapes
488 case Op_Return: {
489 if (n->req() > TypeFunc::Parms &&
490 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
491 // Treat Return value as LocalVar with GlobalEscape escape state.
492 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
493 n->in(TypeFunc::Parms), delayed_worklist);
494 }
495 break;
496 }
497 case Op_CompareAndExchangeP:
498 case Op_CompareAndExchangeN:
499 case Op_GetAndSetP:
500 case Op_GetAndSetN: {
501 add_objload_to_connection_graph(n, delayed_worklist);
502 // fallthrough
503 }
504 case Op_StoreP:
505 case Op_StoreN:
506 case Op_StoreNKlass:
507 case Op_StorePConditional:
508 case Op_WeakCompareAndSwapP:
509 case Op_WeakCompareAndSwapN:
510 case Op_CompareAndSwapP:
511 case Op_CompareAndSwapN: {
512 Node* adr = n->in(MemNode::Address);
513 const Type *adr_type = igvn->type(adr);
514 adr_type = adr_type->make_ptr();
515 if (adr_type == NULL) {
516 break; // skip dead nodes
517 }
518 if ( adr_type->isa_oopptr()
519 || ( (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
520 && adr_type == TypeRawPtr::NOTNULL
521 && adr->in(AddPNode::Address)->is_Proj()
522 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
523 delayed_worklist->push(n); // Process it later.
524 #ifdef ASSERT
525 assert(adr->is_AddP(), "expecting an AddP");
526 if (adr_type == TypeRawPtr::NOTNULL) {
527 // Verify a raw address for a store captured by Initialize node.
528 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
529 assert(offs != Type::OffsetBot, "offset must be a constant");
530 }
531 #endif
532 } else {
533 // Ignore copy the displaced header to the BoxNode (OSR compilation).
534 if (adr->is_BoxLock())
535 break;
536 // Stored value escapes in unsafe access.
537 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
538 // Pointer stores in G1 barriers looks like unsafe access.
539 // Ignore such stores to be able scalar replace non-escaping
540 // allocations.
541 if (UseG1GC && adr->is_AddP()) {
542 Node* base = get_addp_base(adr);
543 if (base->Opcode() == Op_LoadP &&
544 base->in(MemNode::Address)->is_AddP()) {
545 adr = base->in(MemNode::Address);
546 Node* tls = get_addp_base(adr);
547 if (tls->Opcode() == Op_ThreadLocal) {
548 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
549 if (offs == in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset())) {
550 break; // G1 pre barrier previous oop value store.
551 }
552 if (offs == in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset())) {
553 break; // G1 post barrier card address store.
554 }
555 }
556 }
557 }
558 delayed_worklist->push(n); // Process unsafe access later.
559 break;
560 }
561 #ifdef ASSERT
562 n->dump(1);
563 assert(false, "not unsafe or G1 barrier raw StoreP");
564 #endif
565 }
566 break;
567 }
568 case Op_AryEq:
569 case Op_HasNegatives:
570 case Op_StrComp:
571 case Op_StrEquals:
572 case Op_StrIndexOf:
573 case Op_StrIndexOfChar:
574 case Op_StrInflatedCopy:
575 case Op_StrCompressedCopy:
576 case Op_EncodeISOArray: {
577 add_local_var(n, PointsToNode::ArgEscape);
578 delayed_worklist->push(n); // Process it later.
579 break;
580 }
581 case Op_ThreadLocal: {
582 add_java_object(n, PointsToNode::ArgEscape);
583 break;
584 }
585 default:
586 ; // Do nothing for nodes not related to EA.
587 }
588 return;
589 }
590
591 #ifdef ASSERT
592 #define ELSE_FAIL(name) \
593 /* Should not be called for not pointer type. */ \
594 n->dump(1); \
595 assert(false, name); \
596 break;
597 #else
598 #define ELSE_FAIL(name) \
599 break;
600 #endif
601
602 // Add final simple edges to graph.
603 void ConnectionGraph::add_final_edges(Node *n) {
604 PointsToNode* n_ptn = ptnode_adr(n->_idx);
605 #ifdef ASSERT
606 if (_verify && n_ptn->is_JavaObject())
607 return; // This method does not change graph for JavaObject.
608 #endif
609
610 if (n->is_Call()) {
611 process_call_arguments(n->as_Call());
612 return;
613 }
614 assert(n->is_Store() || n->is_LoadStore() ||
615 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
616 "node should be registered already");
617 int opcode = n->Opcode();
618 switch (opcode) {
619 case Op_AddP: {
620 Node* base = get_addp_base(n);
621 PointsToNode* ptn_base = ptnode_adr(base->_idx);
622 assert(ptn_base != NULL, "field's base should be registered");
623 add_base(n_ptn->as_Field(), ptn_base);
624 break;
625 }
626 case Op_CastPP:
627 case Op_CheckCastPP:
628 case Op_EncodeP:
629 case Op_DecodeN:
630 case Op_EncodePKlass:
631 case Op_DecodeNKlass: {
632 add_local_var_and_edge(n, PointsToNode::NoEscape,
633 n->in(1), NULL);
634 break;
635 }
636 case Op_CMoveP: {
637 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
638 Node* in = n->in(i);
639 if (in == NULL)
640 continue; // ignore NULL
641 Node* uncast_in = in->uncast();
642 if (uncast_in->is_top() || uncast_in == n)
643 continue; // ignore top or inputs which go back this node
644 PointsToNode* ptn = ptnode_adr(in->_idx);
645 assert(ptn != NULL, "node should be registered");
646 add_edge(n_ptn, ptn);
647 }
648 break;
649 }
650 case Op_LoadP:
651 case Op_LoadN:
652 case Op_LoadPLocked: {
653 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
654 // ThreadLocal has RawPtr type.
655 const Type* t = _igvn->type(n);
656 if (t->make_ptr() != NULL) {
657 Node* adr = n->in(MemNode::Address);
658 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
659 break;
660 }
661 ELSE_FAIL("Op_LoadP");
662 }
663 case Op_Phi: {
664 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
665 // ThreadLocal has RawPtr type.
666 const Type* t = n->as_Phi()->type();
667 if (t->make_ptr() != NULL) {
668 for (uint i = 1; i < n->req(); i++) {
669 Node* in = n->in(i);
670 if (in == NULL)
671 continue; // ignore NULL
672 Node* uncast_in = in->uncast();
673 if (uncast_in->is_top() || uncast_in == n)
674 continue; // ignore top or inputs which go back this node
675 PointsToNode* ptn = ptnode_adr(in->_idx);
676 assert(ptn != NULL, "node should be registered");
677 add_edge(n_ptn, ptn);
678 }
679 break;
680 }
681 ELSE_FAIL("Op_Phi");
682 }
683 case Op_Proj: {
684 // we are only interested in the oop result projection from a call
685 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
686 n->in(0)->as_Call()->returns_pointer()) {
687 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
688 break;
689 }
690 ELSE_FAIL("Op_Proj");
691 }
692 case Op_Rethrow: // Exception object escapes
693 case Op_Return: {
694 if (n->req() > TypeFunc::Parms &&
695 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
696 // Treat Return value as LocalVar with GlobalEscape escape state.
697 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
698 n->in(TypeFunc::Parms), NULL);
699 break;
700 }
701 ELSE_FAIL("Op_Return");
702 }
703 case Op_StoreP:
704 case Op_StoreN:
705 case Op_StoreNKlass:
706 case Op_StorePConditional:
707 case Op_CompareAndExchangeP:
708 case Op_CompareAndExchangeN:
709 case Op_CompareAndSwapP:
710 case Op_CompareAndSwapN:
711 case Op_WeakCompareAndSwapP:
712 case Op_WeakCompareAndSwapN:
713 case Op_GetAndSetP:
714 case Op_GetAndSetN: {
715 Node* adr = n->in(MemNode::Address);
716 const Type *adr_type = _igvn->type(adr);
717 adr_type = adr_type->make_ptr();
718 #ifdef ASSERT
719 if (adr_type == NULL) {
720 n->dump(1);
721 assert(adr_type != NULL, "dead node should not be on list");
722 break;
723 }
724 #endif
725 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
726 opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
727 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
728 }
729 if ( adr_type->isa_oopptr()
730 || ( (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
731 && adr_type == TypeRawPtr::NOTNULL
732 && adr->in(AddPNode::Address)->is_Proj()
733 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
734 // Point Address to Value
735 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
736 assert(adr_ptn != NULL &&
737 adr_ptn->as_Field()->is_oop(), "node should be registered");
738 Node *val = n->in(MemNode::ValueIn);
739 PointsToNode* ptn = ptnode_adr(val->_idx);
740 assert(ptn != NULL, "node should be registered");
741 add_edge(adr_ptn, ptn);
742 break;
743 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
744 // Stored value escapes in unsafe access.
745 Node *val = n->in(MemNode::ValueIn);
746 PointsToNode* ptn = ptnode_adr(val->_idx);
747 assert(ptn != NULL, "node should be registered");
748 set_escape_state(ptn, PointsToNode::GlobalEscape);
749 // Add edge to object for unsafe access with offset.
750 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
751 assert(adr_ptn != NULL, "node should be registered");
752 if (adr_ptn->is_Field()) {
753 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
754 add_edge(adr_ptn, ptn);
755 }
756 break;
757 }
758 ELSE_FAIL("Op_StoreP");
759 }
760 case Op_AryEq:
761 case Op_HasNegatives:
762 case Op_StrComp:
763 case Op_StrEquals:
764 case Op_StrIndexOf:
765 case Op_StrIndexOfChar:
766 case Op_StrInflatedCopy:
767 case Op_StrCompressedCopy:
768 case Op_EncodeISOArray: {
769 // char[]/byte[] arrays passed to string intrinsic do not escape but
770 // they are not scalar replaceable. Adjust escape state for them.
771 // Start from in(2) edge since in(1) is memory edge.
772 for (uint i = 2; i < n->req(); i++) {
773 Node* adr = n->in(i);
774 const Type* at = _igvn->type(adr);
775 if (!adr->is_top() && at->isa_ptr()) {
776 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
777 at->isa_ptr() != NULL, "expecting a pointer");
778 if (adr->is_AddP()) {
779 adr = get_addp_base(adr);
780 }
781 PointsToNode* ptn = ptnode_adr(adr->_idx);
782 assert(ptn != NULL, "node should be registered");
783 add_edge(n_ptn, ptn);
784 }
785 }
786 break;
787 }
788 default: {
789 // This method should be called only for EA specific nodes which may
790 // miss some edges when they were created.
791 #ifdef ASSERT
792 n->dump(1);
793 #endif
794 guarantee(false, "unknown node");
795 }
796 }
797 return;
798 }
799
800 void ConnectionGraph::add_call_node(CallNode* call) {
801 assert(call->returns_pointer(), "only for call which returns pointer");
802 uint call_idx = call->_idx;
803 if (call->is_Allocate()) {
804 Node* k = call->in(AllocateNode::KlassNode);
805 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
806 assert(kt != NULL, "TypeKlassPtr required.");
807 ciKlass* cik = kt->klass();
808 PointsToNode::EscapeState es = PointsToNode::NoEscape;
809 bool scalar_replaceable = true;
810 if (call->is_AllocateArray()) {
811 if (!cik->is_array_klass()) { // StressReflectiveCode
812 es = PointsToNode::GlobalEscape;
813 } else {
814 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
815 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
816 // Not scalar replaceable if the length is not constant or too big.
817 scalar_replaceable = false;
818 }
819 }
820 } else { // Allocate instance
821 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
822 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
823 !cik->is_instance_klass() || // StressReflectiveCode
824 !cik->as_instance_klass()->can_be_instantiated() ||
825 cik->as_instance_klass()->has_finalizer()) {
826 es = PointsToNode::GlobalEscape;
827 }
828 }
829 add_java_object(call, es);
830 PointsToNode* ptn = ptnode_adr(call_idx);
831 if (!scalar_replaceable && ptn->scalar_replaceable()) {
832 ptn->set_scalar_replaceable(false);
833 }
834 } else if (call->is_CallStaticJava()) {
835 // Call nodes could be different types:
836 //
837 // 1. CallDynamicJavaNode (what happened during call is unknown):
838 //
839 // - mapped to GlobalEscape JavaObject node if oop is returned;
840 //
841 // - all oop arguments are escaping globally;
842 //
843 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
844 //
845 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
846 //
847 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
848 // - mapped to NoEscape JavaObject node if non-escaping object allocated
849 // during call is returned;
850 // - mapped to ArgEscape LocalVar node pointed to object arguments
851 // which are returned and does not escape during call;
852 //
853 // - oop arguments escaping status is defined by bytecode analysis;
854 //
855 // For a static call, we know exactly what method is being called.
856 // Use bytecode estimator to record whether the call's return value escapes.
857 ciMethod* meth = call->as_CallJava()->method();
858 if (meth == NULL) {
859 const char* name = call->as_CallStaticJava()->_name;
860 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
861 // Returns a newly allocated unescaped object.
862 add_java_object(call, PointsToNode::NoEscape);
863 ptnode_adr(call_idx)->set_scalar_replaceable(false);
864 } else if (meth->is_boxing_method()) {
865 // Returns boxing object
866 PointsToNode::EscapeState es;
867 vmIntrinsics::ID intr = meth->intrinsic_id();
868 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
869 // It does not escape if object is always allocated.
870 es = PointsToNode::NoEscape;
871 } else {
872 // It escapes globally if object could be loaded from cache.
873 es = PointsToNode::GlobalEscape;
874 }
875 add_java_object(call, es);
876 } else {
877 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
878 call_analyzer->copy_dependencies(_compile->dependencies());
879 if (call_analyzer->is_return_allocated()) {
880 // Returns a newly allocated unescaped object, simply
881 // update dependency information.
882 // Mark it as NoEscape so that objects referenced by
883 // it's fields will be marked as NoEscape at least.
884 add_java_object(call, PointsToNode::NoEscape);
885 ptnode_adr(call_idx)->set_scalar_replaceable(false);
886 } else {
887 // Determine whether any arguments are returned.
888 const TypeTuple* d = call->tf()->domain();
889 bool ret_arg = false;
890 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
891 if (d->field_at(i)->isa_ptr() != NULL &&
892 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
893 ret_arg = true;
894 break;
895 }
896 }
897 if (ret_arg) {
898 add_local_var(call, PointsToNode::ArgEscape);
899 } else {
900 // Returns unknown object.
901 map_ideal_node(call, phantom_obj);
902 }
903 }
904 }
905 } else {
906 // An other type of call, assume the worst case:
907 // returned value is unknown and globally escapes.
908 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
909 map_ideal_node(call, phantom_obj);
910 }
911 }
912
913 void ConnectionGraph::process_call_arguments(CallNode *call) {
914 bool is_arraycopy = false;
915 switch (call->Opcode()) {
916 #ifdef ASSERT
917 case Op_Allocate:
918 case Op_AllocateArray:
919 case Op_Lock:
920 case Op_Unlock:
921 assert(false, "should be done already");
922 break;
923 #endif
924 case Op_ArrayCopy:
925 case Op_CallLeafNoFP:
926 // Most array copies are ArrayCopy nodes at this point but there
927 // are still a few direct calls to the copy subroutines (See
928 // PhaseStringOpts::copy_string())
929 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
930 call->as_CallLeaf()->is_call_to_arraycopystub();
931 // fall through
932 case Op_CallLeaf: {
933 // Stub calls, objects do not escape but they are not scale replaceable.
934 // Adjust escape state for outgoing arguments.
935 const TypeTuple * d = call->tf()->domain();
936 bool src_has_oops = false;
937 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
938 const Type* at = d->field_at(i);
939 Node *arg = call->in(i);
940 if (arg == NULL) {
941 continue;
942 }
943 const Type *aat = _igvn->type(arg);
944 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
945 continue;
946 if (arg->is_AddP()) {
947 //
948 // The inline_native_clone() case when the arraycopy stub is called
949 // after the allocation before Initialize and CheckCastPP nodes.
950 // Or normal arraycopy for object arrays case.
951 //
952 // Set AddP's base (Allocate) as not scalar replaceable since
953 // pointer to the base (with offset) is passed as argument.
954 //
955 arg = get_addp_base(arg);
956 }
957 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
958 assert(arg_ptn != NULL, "should be registered");
959 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
960 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
961 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
962 aat->isa_ptr() != NULL, "expecting an Ptr");
963 bool arg_has_oops = aat->isa_oopptr() &&
964 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
965 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
966 if (i == TypeFunc::Parms) {
967 src_has_oops = arg_has_oops;
968 }
969 //
970 // src or dst could be j.l.Object when other is basic type array:
971 //
972 // arraycopy(char[],0,Object*,0,size);
973 // arraycopy(Object*,0,char[],0,size);
974 //
975 // Don't add edges in such cases.
976 //
977 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
978 arg_has_oops && (i > TypeFunc::Parms);
979 #ifdef ASSERT
980 if (!(is_arraycopy ||
981 (call->as_CallLeaf()->_name != NULL &&
982 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
983 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
984 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
985 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
986 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
993 strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1002 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1003 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1004 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1005 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1006 ))) {
1007 call->dump();
1008 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1009 }
1010 #endif
1011 // Always process arraycopy's destination object since
1012 // we need to add all possible edges to references in
1013 // source object.
1014 if (arg_esc >= PointsToNode::ArgEscape &&
1015 !arg_is_arraycopy_dest) {
1016 continue;
1017 }
1018 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1019 if (call->is_ArrayCopy()) {
1020 ArrayCopyNode* ac = call->as_ArrayCopy();
1021 if (ac->is_clonebasic() ||
1022 ac->is_arraycopy_validated() ||
1023 ac->is_copyof_validated() ||
1024 ac->is_copyofrange_validated()) {
1025 es = PointsToNode::NoEscape;
1026 }
1027 }
1028 set_escape_state(arg_ptn, es);
1029 if (arg_is_arraycopy_dest) {
1030 Node* src = call->in(TypeFunc::Parms);
1031 if (src->is_AddP()) {
1032 src = get_addp_base(src);
1033 }
1034 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1035 assert(src_ptn != NULL, "should be registered");
1036 if (arg_ptn != src_ptn) {
1037 // Special arraycopy edge:
1038 // A destination object's field can't have the source object
1039 // as base since objects escape states are not related.
1040 // Only escape state of destination object's fields affects
1041 // escape state of fields in source object.
1042 add_arraycopy(call, es, src_ptn, arg_ptn);
1043 }
1044 }
1045 }
1046 }
1047 break;
1048 }
1049 case Op_CallStaticJava: {
1050 // For a static call, we know exactly what method is being called.
1051 // Use bytecode estimator to record the call's escape affects
1052 #ifdef ASSERT
1053 const char* name = call->as_CallStaticJava()->_name;
1054 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1055 #endif
1056 ciMethod* meth = call->as_CallJava()->method();
1057 if ((meth != NULL) && meth->is_boxing_method()) {
1058 break; // Boxing methods do not modify any oops.
1059 }
1060 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1061 // fall-through if not a Java method or no analyzer information
1062 if (call_analyzer != NULL) {
1063 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1064 const TypeTuple* d = call->tf()->domain();
1065 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1066 const Type* at = d->field_at(i);
1067 int k = i - TypeFunc::Parms;
1068 Node* arg = call->in(i);
1069 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1070 if (at->isa_ptr() != NULL &&
1071 call_analyzer->is_arg_returned(k)) {
1072 // The call returns arguments.
1073 if (call_ptn != NULL) { // Is call's result used?
1074 assert(call_ptn->is_LocalVar(), "node should be registered");
1075 assert(arg_ptn != NULL, "node should be registered");
1076 add_edge(call_ptn, arg_ptn);
1077 }
1078 }
1079 if (at->isa_oopptr() != NULL &&
1080 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1081 if (!call_analyzer->is_arg_stack(k)) {
1082 // The argument global escapes
1083 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1084 } else {
1085 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1086 if (!call_analyzer->is_arg_local(k)) {
1087 // The argument itself doesn't escape, but any fields might
1088 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1089 }
1090 }
1091 }
1092 }
1093 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1094 // The call returns arguments.
1095 assert(call_ptn->edge_count() > 0, "sanity");
1096 if (!call_analyzer->is_return_local()) {
1097 // Returns also unknown object.
1098 add_edge(call_ptn, phantom_obj);
1099 }
1100 }
1101 break;
1102 }
1103 }
1104 default: {
1105 // Fall-through here if not a Java method or no analyzer information
1106 // or some other type of call, assume the worst case: all arguments
1107 // globally escape.
1108 const TypeTuple* d = call->tf()->domain();
1109 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1110 const Type* at = d->field_at(i);
1111 if (at->isa_oopptr() != NULL) {
1112 Node* arg = call->in(i);
1113 if (arg->is_AddP()) {
1114 arg = get_addp_base(arg);
1115 }
1116 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1117 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1118 }
1119 }
1120 }
1121 }
1122 }
1123
1124
1125 // Finish Graph construction.
1126 bool ConnectionGraph::complete_connection_graph(
1127 GrowableArray<PointsToNode*>& ptnodes_worklist,
1128 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1129 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1130 GrowableArray<FieldNode*>& oop_fields_worklist) {
1131 // Normally only 1-3 passes needed to build Connection Graph depending
1132 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1133 // Set limit to 20 to catch situation when something did go wrong and
1134 // bailout Escape Analysis.
1135 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1136 #define CG_BUILD_ITER_LIMIT 20
1137
1138 // Propagate GlobalEscape and ArgEscape escape states and check that
1139 // we still have non-escaping objects. The method pushs on _worklist
1140 // Field nodes which reference phantom_object.
1141 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1142 return false; // Nothing to do.
1143 }
1144 // Now propagate references to all JavaObject nodes.
1145 int java_objects_length = java_objects_worklist.length();
1146 elapsedTimer time;
1147 bool timeout = false;
1148 int new_edges = 1;
1149 int iterations = 0;
1150 do {
1151 while ((new_edges > 0) &&
1152 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1153 double start_time = time.seconds();
1154 time.start();
1155 new_edges = 0;
1156 // Propagate references to phantom_object for nodes pushed on _worklist
1157 // by find_non_escaped_objects() and find_field_value().
1158 new_edges += add_java_object_edges(phantom_obj, false);
1159 for (int next = 0; next < java_objects_length; ++next) {
1160 JavaObjectNode* ptn = java_objects_worklist.at(next);
1161 new_edges += add_java_object_edges(ptn, true);
1162
1163 #define SAMPLE_SIZE 4
1164 if ((next % SAMPLE_SIZE) == 0) {
1165 // Each 4 iterations calculate how much time it will take
1166 // to complete graph construction.
1167 time.stop();
1168 // Poll for requests from shutdown mechanism to quiesce compiler
1169 // because Connection graph construction may take long time.
1170 CompileBroker::maybe_block();
1171 double stop_time = time.seconds();
1172 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1173 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1174 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1175 timeout = true;
1176 break; // Timeout
1177 }
1178 start_time = stop_time;
1179 time.start();
1180 }
1181 #undef SAMPLE_SIZE
1182
1183 }
1184 if (timeout) break;
1185 if (new_edges > 0) {
1186 // Update escape states on each iteration if graph was updated.
1187 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1188 return false; // Nothing to do.
1189 }
1190 }
1191 time.stop();
1192 if (time.seconds() >= EscapeAnalysisTimeout) {
1193 timeout = true;
1194 break;
1195 }
1196 }
1197 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1198 time.start();
1199 // Find fields which have unknown value.
1200 int fields_length = oop_fields_worklist.length();
1201 for (int next = 0; next < fields_length; next++) {
1202 FieldNode* field = oop_fields_worklist.at(next);
1203 if (field->edge_count() == 0) {
1204 new_edges += find_field_value(field);
1205 // This code may added new edges to phantom_object.
1206 // Need an other cycle to propagate references to phantom_object.
1207 }
1208 }
1209 time.stop();
1210 if (time.seconds() >= EscapeAnalysisTimeout) {
1211 timeout = true;
1212 break;
1213 }
1214 } else {
1215 new_edges = 0; // Bailout
1216 }
1217 } while (new_edges > 0);
1218
1219 // Bailout if passed limits.
1220 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1221 Compile* C = _compile;
1222 if (C->log() != NULL) {
1223 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1224 C->log()->text("%s", timeout ? "time" : "iterations");
1225 C->log()->end_elem(" limit'");
1226 }
1227 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1228 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1229 // Possible infinite build_connection_graph loop,
1230 // bailout (no changes to ideal graph were made).
1231 return false;
1232 }
1233 #ifdef ASSERT
1234 if (Verbose && PrintEscapeAnalysis) {
1235 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1236 iterations, nodes_size(), ptnodes_worklist.length());
1237 }
1238 #endif
1239
1240 #undef CG_BUILD_ITER_LIMIT
1241
1242 // Find fields initialized by NULL for non-escaping Allocations.
1243 int non_escaped_length = non_escaped_worklist.length();
1244 for (int next = 0; next < non_escaped_length; next++) {
1245 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1246 PointsToNode::EscapeState es = ptn->escape_state();
1247 assert(es <= PointsToNode::ArgEscape, "sanity");
1248 if (es == PointsToNode::NoEscape) {
1249 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1250 // Adding references to NULL object does not change escape states
1251 // since it does not escape. Also no fields are added to NULL object.
1252 add_java_object_edges(null_obj, false);
1253 }
1254 }
1255 Node* n = ptn->ideal_node();
1256 if (n->is_Allocate()) {
1257 // The object allocated by this Allocate node will never be
1258 // seen by an other thread. Mark it so that when it is
1259 // expanded no MemBarStoreStore is added.
1260 InitializeNode* ini = n->as_Allocate()->initialization();
1261 if (ini != NULL)
1262 ini->set_does_not_escape();
1263 }
1264 }
1265 return true; // Finished graph construction.
1266 }
1267
1268 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1269 // and check that we still have non-escaping java objects.
1270 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1271 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1272 GrowableArray<PointsToNode*> escape_worklist;
1273 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1274 int ptnodes_length = ptnodes_worklist.length();
1275 for (int next = 0; next < ptnodes_length; ++next) {
1276 PointsToNode* ptn = ptnodes_worklist.at(next);
1277 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1278 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1279 escape_worklist.push(ptn);
1280 }
1281 }
1282 // Set escape states to referenced nodes (edges list).
1283 while (escape_worklist.length() > 0) {
1284 PointsToNode* ptn = escape_worklist.pop();
1285 PointsToNode::EscapeState es = ptn->escape_state();
1286 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1287 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1288 es >= PointsToNode::ArgEscape) {
1289 // GlobalEscape or ArgEscape state of field means it has unknown value.
1290 if (add_edge(ptn, phantom_obj)) {
1291 // New edge was added
1292 add_field_uses_to_worklist(ptn->as_Field());
1293 }
1294 }
1295 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1296 PointsToNode* e = i.get();
1297 if (e->is_Arraycopy()) {
1298 assert(ptn->arraycopy_dst(), "sanity");
1299 // Propagate only fields escape state through arraycopy edge.
1300 if (e->fields_escape_state() < field_es) {
1301 set_fields_escape_state(e, field_es);
1302 escape_worklist.push(e);
1303 }
1304 } else if (es >= field_es) {
1305 // fields_escape_state is also set to 'es' if it is less than 'es'.
1306 if (e->escape_state() < es) {
1307 set_escape_state(e, es);
1308 escape_worklist.push(e);
1309 }
1310 } else {
1311 // Propagate field escape state.
1312 bool es_changed = false;
1313 if (e->fields_escape_state() < field_es) {
1314 set_fields_escape_state(e, field_es);
1315 es_changed = true;
1316 }
1317 if ((e->escape_state() < field_es) &&
1318 e->is_Field() && ptn->is_JavaObject() &&
1319 e->as_Field()->is_oop()) {
1320 // Change escape state of referenced fields.
1321 set_escape_state(e, field_es);
1322 es_changed = true;
1323 } else if (e->escape_state() < es) {
1324 set_escape_state(e, es);
1325 es_changed = true;
1326 }
1327 if (es_changed) {
1328 escape_worklist.push(e);
1329 }
1330 }
1331 }
1332 }
1333 // Remove escaped objects from non_escaped list.
1334 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1335 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1336 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1337 non_escaped_worklist.delete_at(next);
1338 }
1339 if (ptn->escape_state() == PointsToNode::NoEscape) {
1340 // Find fields in non-escaped allocations which have unknown value.
1341 find_init_values(ptn, phantom_obj, NULL);
1342 }
1343 }
1344 return (non_escaped_worklist.length() > 0);
1345 }
1346
1347 // Add all references to JavaObject node by walking over all uses.
1348 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1349 int new_edges = 0;
1350 if (populate_worklist) {
1351 // Populate _worklist by uses of jobj's uses.
1352 for (UseIterator i(jobj); i.has_next(); i.next()) {
1353 PointsToNode* use = i.get();
1354 if (use->is_Arraycopy())
1355 continue;
1356 add_uses_to_worklist(use);
1357 if (use->is_Field() && use->as_Field()->is_oop()) {
1358 // Put on worklist all field's uses (loads) and
1359 // related field nodes (same base and offset).
1360 add_field_uses_to_worklist(use->as_Field());
1361 }
1362 }
1363 }
1364 for (int l = 0; l < _worklist.length(); l++) {
1365 PointsToNode* use = _worklist.at(l);
1366 if (PointsToNode::is_base_use(use)) {
1367 // Add reference from jobj to field and from field to jobj (field's base).
1368 use = PointsToNode::get_use_node(use)->as_Field();
1369 if (add_base(use->as_Field(), jobj)) {
1370 new_edges++;
1371 }
1372 continue;
1373 }
1374 assert(!use->is_JavaObject(), "sanity");
1375 if (use->is_Arraycopy()) {
1376 if (jobj == null_obj) // NULL object does not have field edges
1377 continue;
1378 // Added edge from Arraycopy node to arraycopy's source java object
1379 if (add_edge(use, jobj)) {
1380 jobj->set_arraycopy_src();
1381 new_edges++;
1382 }
1383 // and stop here.
1384 continue;
1385 }
1386 if (!add_edge(use, jobj))
1387 continue; // No new edge added, there was such edge already.
1388 new_edges++;
1389 if (use->is_LocalVar()) {
1390 add_uses_to_worklist(use);
1391 if (use->arraycopy_dst()) {
1392 for (EdgeIterator i(use); i.has_next(); i.next()) {
1393 PointsToNode* e = i.get();
1394 if (e->is_Arraycopy()) {
1395 if (jobj == null_obj) // NULL object does not have field edges
1396 continue;
1397 // Add edge from arraycopy's destination java object to Arraycopy node.
1398 if (add_edge(jobj, e)) {
1399 new_edges++;
1400 jobj->set_arraycopy_dst();
1401 }
1402 }
1403 }
1404 }
1405 } else {
1406 // Added new edge to stored in field values.
1407 // Put on worklist all field's uses (loads) and
1408 // related field nodes (same base and offset).
1409 add_field_uses_to_worklist(use->as_Field());
1410 }
1411 }
1412 _worklist.clear();
1413 _in_worklist.Reset();
1414 return new_edges;
1415 }
1416
1417 // Put on worklist all related field nodes.
1418 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1419 assert(field->is_oop(), "sanity");
1420 int offset = field->offset();
1421 add_uses_to_worklist(field);
1422 // Loop over all bases of this field and push on worklist Field nodes
1423 // with the same offset and base (since they may reference the same field).
1424 for (BaseIterator i(field); i.has_next(); i.next()) {
1425 PointsToNode* base = i.get();
1426 add_fields_to_worklist(field, base);
1427 // Check if the base was source object of arraycopy and go over arraycopy's
1428 // destination objects since values stored to a field of source object are
1429 // accessable by uses (loads) of fields of destination objects.
1430 if (base->arraycopy_src()) {
1431 for (UseIterator j(base); j.has_next(); j.next()) {
1432 PointsToNode* arycp = j.get();
1433 if (arycp->is_Arraycopy()) {
1434 for (UseIterator k(arycp); k.has_next(); k.next()) {
1435 PointsToNode* abase = k.get();
1436 if (abase->arraycopy_dst() && abase != base) {
1437 // Look for the same arraycopy reference.
1438 add_fields_to_worklist(field, abase);
1439 }
1440 }
1441 }
1442 }
1443 }
1444 }
1445 }
1446
1447 // Put on worklist all related field nodes.
1448 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1449 int offset = field->offset();
1450 if (base->is_LocalVar()) {
1451 for (UseIterator j(base); j.has_next(); j.next()) {
1452 PointsToNode* f = j.get();
1453 if (PointsToNode::is_base_use(f)) { // Field
1454 f = PointsToNode::get_use_node(f);
1455 if (f == field || !f->as_Field()->is_oop())
1456 continue;
1457 int offs = f->as_Field()->offset();
1458 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1459 add_to_worklist(f);
1460 }
1461 }
1462 }
1463 } else {
1464 assert(base->is_JavaObject(), "sanity");
1465 if (// Skip phantom_object since it is only used to indicate that
1466 // this field's content globally escapes.
1467 (base != phantom_obj) &&
1468 // NULL object node does not have fields.
1469 (base != null_obj)) {
1470 for (EdgeIterator i(base); i.has_next(); i.next()) {
1471 PointsToNode* f = i.get();
1472 // Skip arraycopy edge since store to destination object field
1473 // does not update value in source object field.
1474 if (f->is_Arraycopy()) {
1475 assert(base->arraycopy_dst(), "sanity");
1476 continue;
1477 }
1478 if (f == field || !f->as_Field()->is_oop())
1479 continue;
1480 int offs = f->as_Field()->offset();
1481 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1482 add_to_worklist(f);
1483 }
1484 }
1485 }
1486 }
1487 }
1488
1489 // Find fields which have unknown value.
1490 int ConnectionGraph::find_field_value(FieldNode* field) {
1491 // Escaped fields should have init value already.
1492 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1493 int new_edges = 0;
1494 for (BaseIterator i(field); i.has_next(); i.next()) {
1495 PointsToNode* base = i.get();
1496 if (base->is_JavaObject()) {
1497 // Skip Allocate's fields which will be processed later.
1498 if (base->ideal_node()->is_Allocate())
1499 return 0;
1500 assert(base == null_obj, "only NULL ptr base expected here");
1501 }
1502 }
1503 if (add_edge(field, phantom_obj)) {
1504 // New edge was added
1505 new_edges++;
1506 add_field_uses_to_worklist(field);
1507 }
1508 return new_edges;
1509 }
1510
1511 // Find fields initializing values for allocations.
1512 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1513 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1514 int new_edges = 0;
1515 Node* alloc = pta->ideal_node();
1516 if (init_val == phantom_obj) {
1517 // Do nothing for Allocate nodes since its fields values are
1518 // "known" unless they are initialized by arraycopy/clone.
1519 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1520 return 0;
1521 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1522 #ifdef ASSERT
1523 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1524 const char* name = alloc->as_CallStaticJava()->_name;
1525 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1526 }
1527 #endif
1528 // Non-escaped allocation returned from Java or runtime call have
1529 // unknown values in fields.
1530 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1531 PointsToNode* field = i.get();
1532 if (field->is_Field() && field->as_Field()->is_oop()) {
1533 if (add_edge(field, phantom_obj)) {
1534 // New edge was added
1535 new_edges++;
1536 add_field_uses_to_worklist(field->as_Field());
1537 }
1538 }
1539 }
1540 return new_edges;
1541 }
1542 assert(init_val == null_obj, "sanity");
1543 // Do nothing for Call nodes since its fields values are unknown.
1544 if (!alloc->is_Allocate())
1545 return 0;
1546
1547 InitializeNode* ini = alloc->as_Allocate()->initialization();
1548 bool visited_bottom_offset = false;
1549 GrowableArray<int> offsets_worklist;
1550
1551 // Check if an oop field's initializing value is recorded and add
1552 // a corresponding NULL if field's value if it is not recorded.
1553 // Connection Graph does not record a default initialization by NULL
1554 // captured by Initialize node.
1555 //
1556 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1557 PointsToNode* field = i.get(); // Field (AddP)
1558 if (!field->is_Field() || !field->as_Field()->is_oop())
1559 continue; // Not oop field
1560 int offset = field->as_Field()->offset();
1561 if (offset == Type::OffsetBot) {
1562 if (!visited_bottom_offset) {
1563 // OffsetBot is used to reference array's element,
1564 // always add reference to NULL to all Field nodes since we don't
1565 // known which element is referenced.
1566 if (add_edge(field, null_obj)) {
1567 // New edge was added
1568 new_edges++;
1569 add_field_uses_to_worklist(field->as_Field());
1570 visited_bottom_offset = true;
1571 }
1572 }
1573 } else {
1574 // Check only oop fields.
1575 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1576 if (adr_type->isa_rawptr()) {
1577 #ifdef ASSERT
1578 // Raw pointers are used for initializing stores so skip it
1579 // since it should be recorded already
1580 Node* base = get_addp_base(field->ideal_node());
1581 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1582 (base->in(0) == alloc),"unexpected pointer type");
1583 #endif
1584 continue;
1585 }
1586 if (!offsets_worklist.contains(offset)) {
1587 offsets_worklist.append(offset);
1588 Node* value = NULL;
1589 if (ini != NULL) {
1590 // StoreP::memory_type() == T_ADDRESS
1591 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1592 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1593 // Make sure initializing store has the same type as this AddP.
1594 // This AddP may reference non existing field because it is on a
1595 // dead branch of bimorphic call which is not eliminated yet.
1596 if (store != NULL && store->is_Store() &&
1597 store->as_Store()->memory_type() == ft) {
1598 value = store->in(MemNode::ValueIn);
1599 #ifdef ASSERT
1600 if (VerifyConnectionGraph) {
1601 // Verify that AddP already points to all objects the value points to.
1602 PointsToNode* val = ptnode_adr(value->_idx);
1603 assert((val != NULL), "should be processed already");
1604 PointsToNode* missed_obj = NULL;
1605 if (val->is_JavaObject()) {
1606 if (!field->points_to(val->as_JavaObject())) {
1607 missed_obj = val;
1608 }
1609 } else {
1610 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1611 tty->print_cr("----------init store has invalid value -----");
1612 store->dump();
1613 val->dump();
1614 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1615 }
1616 for (EdgeIterator j(val); j.has_next(); j.next()) {
1617 PointsToNode* obj = j.get();
1618 if (obj->is_JavaObject()) {
1619 if (!field->points_to(obj->as_JavaObject())) {
1620 missed_obj = obj;
1621 break;
1622 }
1623 }
1624 }
1625 }
1626 if (missed_obj != NULL) {
1627 tty->print_cr("----------field---------------------------------");
1628 field->dump();
1629 tty->print_cr("----------missed referernce to object-----------");
1630 missed_obj->dump();
1631 tty->print_cr("----------object referernced by init store -----");
1632 store->dump();
1633 val->dump();
1634 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1635 }
1636 }
1637 #endif
1638 } else {
1639 // There could be initializing stores which follow allocation.
1640 // For example, a volatile field store is not collected
1641 // by Initialize node.
1642 //
1643 // Need to check for dependent loads to separate such stores from
1644 // stores which follow loads. For now, add initial value NULL so
1645 // that compare pointers optimization works correctly.
1646 }
1647 }
1648 if (value == NULL) {
1649 // A field's initializing value was not recorded. Add NULL.
1650 if (add_edge(field, null_obj)) {
1651 // New edge was added
1652 new_edges++;
1653 add_field_uses_to_worklist(field->as_Field());
1654 }
1655 }
1656 }
1657 }
1658 }
1659 return new_edges;
1660 }
1661
1662 // Adjust scalar_replaceable state after Connection Graph is built.
1663 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1664 // Search for non-escaping objects which are not scalar replaceable
1665 // and mark them to propagate the state to referenced objects.
1666
1667 // 1. An object is not scalar replaceable if the field into which it is
1668 // stored has unknown offset (stored into unknown element of an array).
1669 //
1670 for (UseIterator i(jobj); i.has_next(); i.next()) {
1671 PointsToNode* use = i.get();
1672 if (use->is_Arraycopy()) {
1673 continue;
1674 }
1675 if (use->is_Field()) {
1676 FieldNode* field = use->as_Field();
1677 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1678 if (field->offset() == Type::OffsetBot) {
1679 jobj->set_scalar_replaceable(false);
1680 return;
1681 }
1682 // 2. An object is not scalar replaceable if the field into which it is
1683 // stored has multiple bases one of which is null.
1684 if (field->base_count() > 1) {
1685 for (BaseIterator i(field); i.has_next(); i.next()) {
1686 PointsToNode* base = i.get();
1687 if (base == null_obj) {
1688 jobj->set_scalar_replaceable(false);
1689 return;
1690 }
1691 }
1692 }
1693 }
1694 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1695 // 3. An object is not scalar replaceable if it is merged with other objects.
1696 for (EdgeIterator j(use); j.has_next(); j.next()) {
1697 PointsToNode* ptn = j.get();
1698 if (ptn->is_JavaObject() && ptn != jobj) {
1699 // Mark all objects.
1700 jobj->set_scalar_replaceable(false);
1701 ptn->set_scalar_replaceable(false);
1702 }
1703 }
1704 if (!jobj->scalar_replaceable()) {
1705 return;
1706 }
1707 }
1708
1709 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1710 if (j.get()->is_Arraycopy()) {
1711 continue;
1712 }
1713
1714 // Non-escaping object node should point only to field nodes.
1715 FieldNode* field = j.get()->as_Field();
1716 int offset = field->as_Field()->offset();
1717
1718 // 4. An object is not scalar replaceable if it has a field with unknown
1719 // offset (array's element is accessed in loop).
1720 if (offset == Type::OffsetBot) {
1721 jobj->set_scalar_replaceable(false);
1722 return;
1723 }
1724 // 5. Currently an object is not scalar replaceable if a LoadStore node
1725 // access its field since the field value is unknown after it.
1726 //
1727 Node* n = field->ideal_node();
1728 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1729 if (n->fast_out(i)->is_LoadStore()) {
1730 jobj->set_scalar_replaceable(false);
1731 return;
1732 }
1733 }
1734
1735 // 6. Or the address may point to more then one object. This may produce
1736 // the false positive result (set not scalar replaceable)
1737 // since the flow-insensitive escape analysis can't separate
1738 // the case when stores overwrite the field's value from the case
1739 // when stores happened on different control branches.
1740 //
1741 // Note: it will disable scalar replacement in some cases:
1742 //
1743 // Point p[] = new Point[1];
1744 // p[0] = new Point(); // Will be not scalar replaced
1745 //
1746 // but it will save us from incorrect optimizations in next cases:
1747 //
1748 // Point p[] = new Point[1];
1749 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1750 //
1751 if (field->base_count() > 1) {
1752 for (BaseIterator i(field); i.has_next(); i.next()) {
1753 PointsToNode* base = i.get();
1754 // Don't take into account LocalVar nodes which
1755 // may point to only one object which should be also
1756 // this field's base by now.
1757 if (base->is_JavaObject() && base != jobj) {
1758 // Mark all bases.
1759 jobj->set_scalar_replaceable(false);
1760 base->set_scalar_replaceable(false);
1761 }
1762 }
1763 }
1764 }
1765 }
1766
1767 #ifdef ASSERT
1768 void ConnectionGraph::verify_connection_graph(
1769 GrowableArray<PointsToNode*>& ptnodes_worklist,
1770 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1771 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1772 GrowableArray<Node*>& addp_worklist) {
1773 // Verify that graph is complete - no new edges could be added.
1774 int java_objects_length = java_objects_worklist.length();
1775 int non_escaped_length = non_escaped_worklist.length();
1776 int new_edges = 0;
1777 for (int next = 0; next < java_objects_length; ++next) {
1778 JavaObjectNode* ptn = java_objects_worklist.at(next);
1779 new_edges += add_java_object_edges(ptn, true);
1780 }
1781 assert(new_edges == 0, "graph was not complete");
1782 // Verify that escape state is final.
1783 int length = non_escaped_worklist.length();
1784 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1785 assert((non_escaped_length == non_escaped_worklist.length()) &&
1786 (non_escaped_length == length) &&
1787 (_worklist.length() == 0), "escape state was not final");
1788
1789 // Verify fields information.
1790 int addp_length = addp_worklist.length();
1791 for (int next = 0; next < addp_length; ++next ) {
1792 Node* n = addp_worklist.at(next);
1793 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1794 if (field->is_oop()) {
1795 // Verify that field has all bases
1796 Node* base = get_addp_base(n);
1797 PointsToNode* ptn = ptnode_adr(base->_idx);
1798 if (ptn->is_JavaObject()) {
1799 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1800 } else {
1801 assert(ptn->is_LocalVar(), "sanity");
1802 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1803 PointsToNode* e = i.get();
1804 if (e->is_JavaObject()) {
1805 assert(field->has_base(e->as_JavaObject()), "sanity");
1806 }
1807 }
1808 }
1809 // Verify that all fields have initializing values.
1810 if (field->edge_count() == 0) {
1811 tty->print_cr("----------field does not have references----------");
1812 field->dump();
1813 for (BaseIterator i(field); i.has_next(); i.next()) {
1814 PointsToNode* base = i.get();
1815 tty->print_cr("----------field has next base---------------------");
1816 base->dump();
1817 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1818 tty->print_cr("----------base has fields-------------------------");
1819 for (EdgeIterator j(base); j.has_next(); j.next()) {
1820 j.get()->dump();
1821 }
1822 tty->print_cr("----------base has references---------------------");
1823 for (UseIterator j(base); j.has_next(); j.next()) {
1824 j.get()->dump();
1825 }
1826 }
1827 }
1828 for (UseIterator i(field); i.has_next(); i.next()) {
1829 i.get()->dump();
1830 }
1831 assert(field->edge_count() > 0, "sanity");
1832 }
1833 }
1834 }
1835 }
1836 #endif
1837
1838 // Optimize ideal graph.
1839 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1840 GrowableArray<Node*>& storestore_worklist) {
1841 Compile* C = _compile;
1842 PhaseIterGVN* igvn = _igvn;
1843 if (EliminateLocks) {
1844 // Mark locks before changing ideal graph.
1845 int cnt = C->macro_count();
1846 for( int i=0; i < cnt; i++ ) {
1847 Node *n = C->macro_node(i);
1848 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1849 AbstractLockNode* alock = n->as_AbstractLock();
1850 if (!alock->is_non_esc_obj()) {
1851 if (not_global_escape(alock->obj_node())) {
1852 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1853 // The lock could be marked eliminated by lock coarsening
1854 // code during first IGVN before EA. Replace coarsened flag
1855 // to eliminate all associated locks/unlocks.
1856 #ifdef ASSERT
1857 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1858 #endif
1859 alock->set_non_esc_obj();
1860 }
1861 }
1862 }
1863 }
1864 }
1865
1866 if (OptimizePtrCompare) {
1867 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1868 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1869 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1870 // Optimize objects compare.
1871 while (ptr_cmp_worklist.length() != 0) {
1872 Node *n = ptr_cmp_worklist.pop();
1873 Node *res = optimize_ptr_compare(n);
1874 if (res != NULL) {
1875 #ifndef PRODUCT
1876 if (PrintOptimizePtrCompare) {
1877 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"));
1878 if (Verbose) {
1879 n->dump(1);
1880 }
1881 }
1882 #endif
1883 igvn->replace_node(n, res);
1884 }
1885 }
1886 // cleanup
1887 if (_pcmp_neq->outcnt() == 0)
1888 igvn->hash_delete(_pcmp_neq);
1889 if (_pcmp_eq->outcnt() == 0)
1890 igvn->hash_delete(_pcmp_eq);
1891 }
1892
1893 // For MemBarStoreStore nodes added in library_call.cpp, check
1894 // escape status of associated AllocateNode and optimize out
1895 // MemBarStoreStore node if the allocated object never escapes.
1896 while (storestore_worklist.length() != 0) {
1897 Node *n = storestore_worklist.pop();
1898 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1899 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1900 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1901 if (not_global_escape(alloc)) {
1902 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1903 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1904 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1905 igvn->register_new_node_with_optimizer(mb);
1906 igvn->replace_node(storestore, mb);
1907 }
1908 }
1909 }
1910
1911 // Optimize objects compare.
1912 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1913 assert(OptimizePtrCompare, "sanity");
1914 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1915 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1916 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1917 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1918 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1919 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1920
1921 // Check simple cases first.
1922 if (jobj1 != NULL) {
1923 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1924 if (jobj1 == jobj2) {
1925 // Comparing the same not escaping object.
1926 return _pcmp_eq;
1927 }
1928 Node* obj = jobj1->ideal_node();
1929 // Comparing not escaping allocation.
1930 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1931 !ptn2->points_to(jobj1)) {
1932 return _pcmp_neq; // This includes nullness check.
1933 }
1934 }
1935 }
1936 if (jobj2 != NULL) {
1937 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1938 Node* obj = jobj2->ideal_node();
1939 // Comparing not escaping allocation.
1940 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1941 !ptn1->points_to(jobj2)) {
1942 return _pcmp_neq; // This includes nullness check.
1943 }
1944 }
1945 }
1946 if (jobj1 != NULL && jobj1 != phantom_obj &&
1947 jobj2 != NULL && jobj2 != phantom_obj &&
1948 jobj1->ideal_node()->is_Con() &&
1949 jobj2->ideal_node()->is_Con()) {
1950 // Klass or String constants compare. Need to be careful with
1951 // compressed pointers - compare types of ConN and ConP instead of nodes.
1952 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1953 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1954 if (t1->make_ptr() == t2->make_ptr()) {
1955 return _pcmp_eq;
1956 } else {
1957 return _pcmp_neq;
1958 }
1959 }
1960 if (ptn1->meet(ptn2)) {
1961 return NULL; // Sets are not disjoint
1962 }
1963
1964 // Sets are disjoint.
1965 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1966 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1967 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1968 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1969 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
1970 (set2_has_unknown_ptr && set1_has_null_ptr)) {
1971 // Check nullness of unknown object.
1972 return NULL;
1973 }
1974
1975 // Disjointness by itself is not sufficient since
1976 // alias analysis is not complete for escaped objects.
1977 // Disjoint sets are definitely unrelated only when
1978 // at least one set has only not escaping allocations.
1979 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1980 if (ptn1->non_escaping_allocation()) {
1981 return _pcmp_neq;
1982 }
1983 }
1984 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1985 if (ptn2->non_escaping_allocation()) {
1986 return _pcmp_neq;
1987 }
1988 }
1989 return NULL;
1990 }
1991
1992 // Connection Graph constuction functions.
1993
1994 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1995 PointsToNode* ptadr = _nodes.at(n->_idx);
1996 if (ptadr != NULL) {
1997 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1998 return;
1999 }
2000 Compile* C = _compile;
2001 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2002 _nodes.at_put(n->_idx, ptadr);
2003 }
2004
2005 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2006 PointsToNode* ptadr = _nodes.at(n->_idx);
2007 if (ptadr != NULL) {
2008 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2009 return;
2010 }
2011 Compile* C = _compile;
2012 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2013 _nodes.at_put(n->_idx, ptadr);
2014 }
2015
2016 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2017 PointsToNode* ptadr = _nodes.at(n->_idx);
2018 if (ptadr != NULL) {
2019 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2020 return;
2021 }
2022 bool unsafe = false;
2023 bool is_oop = is_oop_field(n, offset, &unsafe);
2024 if (unsafe) {
2025 es = PointsToNode::GlobalEscape;
2026 }
2027 Compile* C = _compile;
2028 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2029 _nodes.at_put(n->_idx, field);
2030 }
2031
2032 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2033 PointsToNode* src, PointsToNode* dst) {
2034 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2035 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2036 PointsToNode* ptadr = _nodes.at(n->_idx);
2037 if (ptadr != NULL) {
2038 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2039 return;
2040 }
2041 Compile* C = _compile;
2042 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2043 _nodes.at_put(n->_idx, ptadr);
2044 // Add edge from arraycopy node to source object.
2045 (void)add_edge(ptadr, src);
2046 src->set_arraycopy_src();
2047 // Add edge from destination object to arraycopy node.
2048 (void)add_edge(dst, ptadr);
2049 dst->set_arraycopy_dst();
2050 }
2051
2052 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2053 const Type* adr_type = n->as_AddP()->bottom_type();
2054 BasicType bt = T_INT;
2055 if (offset == Type::OffsetBot) {
2056 // Check only oop fields.
2057 if (!adr_type->isa_aryptr() ||
2058 (adr_type->isa_aryptr()->klass() == NULL) ||
2059 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2060 // OffsetBot is used to reference array's element. Ignore first AddP.
2061 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2062 bt = T_OBJECT;
2063 }
2064 }
2065 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2066 if (adr_type->isa_instptr()) {
2067 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2068 if (field != NULL) {
2069 bt = field->layout_type();
2070 } else {
2071 // Check for unsafe oop field access
2072 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2073 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2074 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2075 bt = T_OBJECT;
2076 (*unsafe) = true;
2077 }
2078 }
2079 } else if (adr_type->isa_aryptr()) {
2080 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2081 // Ignore array length load.
2082 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2083 // Ignore first AddP.
2084 } else {
2085 const Type* elemtype = adr_type->isa_aryptr()->elem();
2086 bt = elemtype->array_element_basic_type();
2087 }
2088 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2089 // Allocation initialization, ThreadLocal field access, unsafe access
2090 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2091 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2092 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2093 bt = T_OBJECT;
2094 }
2095 }
2096 }
2097 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2098 }
2099
2100 // Returns unique pointed java object or NULL.
2101 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2102 assert(!_collecting, "should not call when contructed graph");
2103 // If the node was created after the escape computation we can't answer.
2104 uint idx = n->_idx;
2105 if (idx >= nodes_size()) {
2106 return NULL;
2107 }
2108 PointsToNode* ptn = ptnode_adr(idx);
2109 if (ptn->is_JavaObject()) {
2110 return ptn->as_JavaObject();
2111 }
2112 assert(ptn->is_LocalVar(), "sanity");
2113 // Check all java objects it points to.
2114 JavaObjectNode* jobj = NULL;
2115 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2116 PointsToNode* e = i.get();
2117 if (e->is_JavaObject()) {
2118 if (jobj == NULL) {
2119 jobj = e->as_JavaObject();
2120 } else if (jobj != e) {
2121 return NULL;
2122 }
2123 }
2124 }
2125 return jobj;
2126 }
2127
2128 // Return true if this node points only to non-escaping allocations.
2129 bool PointsToNode::non_escaping_allocation() {
2130 if (is_JavaObject()) {
2131 Node* n = ideal_node();
2132 if (n->is_Allocate() || n->is_CallStaticJava()) {
2133 return (escape_state() == PointsToNode::NoEscape);
2134 } else {
2135 return false;
2136 }
2137 }
2138 assert(is_LocalVar(), "sanity");
2139 // Check all java objects it points to.
2140 for (EdgeIterator i(this); i.has_next(); i.next()) {
2141 PointsToNode* e = i.get();
2142 if (e->is_JavaObject()) {
2143 Node* n = e->ideal_node();
2144 if ((e->escape_state() != PointsToNode::NoEscape) ||
2145 !(n->is_Allocate() || n->is_CallStaticJava())) {
2146 return false;
2147 }
2148 }
2149 }
2150 return true;
2151 }
2152
2153 // Return true if we know the node does not escape globally.
2154 bool ConnectionGraph::not_global_escape(Node *n) {
2155 assert(!_collecting, "should not call during graph construction");
2156 // If the node was created after the escape computation we can't answer.
2157 uint idx = n->_idx;
2158 if (idx >= nodes_size()) {
2159 return false;
2160 }
2161 PointsToNode* ptn = ptnode_adr(idx);
2162 PointsToNode::EscapeState es = ptn->escape_state();
2163 // If we have already computed a value, return it.
2164 if (es >= PointsToNode::GlobalEscape)
2165 return false;
2166 if (ptn->is_JavaObject()) {
2167 return true; // (es < PointsToNode::GlobalEscape);
2168 }
2169 assert(ptn->is_LocalVar(), "sanity");
2170 // Check all java objects it points to.
2171 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2172 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2173 return false;
2174 }
2175 return true;
2176 }
2177
2178
2179 // Helper functions
2180
2181 // Return true if this node points to specified node or nodes it points to.
2182 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2183 if (is_JavaObject()) {
2184 return (this == ptn);
2185 }
2186 assert(is_LocalVar() || is_Field(), "sanity");
2187 for (EdgeIterator i(this); i.has_next(); i.next()) {
2188 if (i.get() == ptn)
2189 return true;
2190 }
2191 return false;
2192 }
2193
2194 // Return true if one node points to an other.
2195 bool PointsToNode::meet(PointsToNode* ptn) {
2196 if (this == ptn) {
2197 return true;
2198 } else if (ptn->is_JavaObject()) {
2199 return this->points_to(ptn->as_JavaObject());
2200 } else if (this->is_JavaObject()) {
2201 return ptn->points_to(this->as_JavaObject());
2202 }
2203 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2204 int ptn_count = ptn->edge_count();
2205 for (EdgeIterator i(this); i.has_next(); i.next()) {
2206 PointsToNode* this_e = i.get();
2207 for (int j = 0; j < ptn_count; j++) {
2208 if (this_e == ptn->edge(j))
2209 return true;
2210 }
2211 }
2212 return false;
2213 }
2214
2215 #ifdef ASSERT
2216 // Return true if bases point to this java object.
2217 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2218 for (BaseIterator i(this); i.has_next(); i.next()) {
2219 if (i.get() == jobj)
2220 return true;
2221 }
2222 return false;
2223 }
2224 #endif
2225
2226 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2227 const Type *adr_type = phase->type(adr);
2228 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2229 adr->in(AddPNode::Address)->is_Proj() &&
2230 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2231 // We are computing a raw address for a store captured by an Initialize
2232 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2233 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2234 assert(offs != Type::OffsetBot ||
2235 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2236 "offset must be a constant or it is initialization of array");
2237 return offs;
2238 }
2239 const TypePtr *t_ptr = adr_type->isa_ptr();
2240 assert(t_ptr != NULL, "must be a pointer type");
2241 return t_ptr->offset();
2242 }
2243
2244 Node* ConnectionGraph::get_addp_base(Node *addp) {
2245 assert(addp->is_AddP(), "must be AddP");
2246 //
2247 // AddP cases for Base and Address inputs:
2248 // case #1. Direct object's field reference:
2249 // Allocate
2250 // |
2251 // Proj #5 ( oop result )
2252 // |
2253 // CheckCastPP (cast to instance type)
2254 // | |
2255 // AddP ( base == address )
2256 //
2257 // case #2. Indirect object's field reference:
2258 // Phi
2259 // |
2260 // CastPP (cast to instance type)
2261 // | |
2262 // AddP ( base == address )
2263 //
2264 // case #3. Raw object's field reference for Initialize node:
2265 // Allocate
2266 // |
2267 // Proj #5 ( oop result )
2268 // top |
2269 // \ |
2270 // AddP ( base == top )
2271 //
2272 // case #4. Array's element reference:
2273 // {CheckCastPP | CastPP}
2274 // | | |
2275 // | AddP ( array's element offset )
2276 // | |
2277 // AddP ( array's offset )
2278 //
2279 // case #5. Raw object's field reference for arraycopy stub call:
2280 // The inline_native_clone() case when the arraycopy stub is called
2281 // after the allocation before Initialize and CheckCastPP nodes.
2282 // Allocate
2283 // |
2284 // Proj #5 ( oop result )
2285 // | |
2286 // AddP ( base == address )
2287 //
2288 // case #6. Constant Pool, ThreadLocal, CastX2P or
2289 // Raw object's field reference:
2290 // {ConP, ThreadLocal, CastX2P, raw Load}
2291 // top |
2292 // \ |
2293 // AddP ( base == top )
2294 //
2295 // case #7. Klass's field reference.
2296 // LoadKlass
2297 // | |
2298 // AddP ( base == address )
2299 //
2300 // case #8. narrow Klass's field reference.
2301 // LoadNKlass
2302 // |
2303 // DecodeN
2304 // | |
2305 // AddP ( base == address )
2306 //
2307 // case #9. Mixed unsafe access
2308 // {instance}
2309 // |
2310 // CheckCastPP (raw)
2311 // top |
2312 // \ |
2313 // AddP ( base == top )
2314 //
2315 Node *base = addp->in(AddPNode::Base);
2316 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2317 base = addp->in(AddPNode::Address);
2318 while (base->is_AddP()) {
2319 // Case #6 (unsafe access) may have several chained AddP nodes.
2320 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2321 base = base->in(AddPNode::Address);
2322 }
2323 if (base->Opcode() == Op_CheckCastPP &&
2324 base->bottom_type()->isa_rawptr() &&
2325 _igvn->type(base->in(1))->isa_oopptr()) {
2326 base = base->in(1); // Case #9
2327 } else {
2328 Node* uncast_base = base->uncast();
2329 int opcode = uncast_base->Opcode();
2330 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2331 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2332 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2333 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2334 }
2335 }
2336 return base;
2337 }
2338
2339 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2340 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2341 Node* addp2 = addp->raw_out(0);
2342 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2343 addp2->in(AddPNode::Base) == n &&
2344 addp2->in(AddPNode::Address) == addp) {
2345 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2346 //
2347 // Find array's offset to push it on worklist first and
2348 // as result process an array's element offset first (pushed second)
2349 // to avoid CastPP for the array's offset.
2350 // Otherwise the inserted CastPP (LocalVar) will point to what
2351 // the AddP (Field) points to. Which would be wrong since
2352 // the algorithm expects the CastPP has the same point as
2353 // as AddP's base CheckCastPP (LocalVar).
2354 //
2355 // ArrayAllocation
2356 // |
2357 // CheckCastPP
2358 // |
2359 // memProj (from ArrayAllocation CheckCastPP)
2360 // | ||
2361 // | || Int (element index)
2362 // | || | ConI (log(element size))
2363 // | || | /
2364 // | || LShift
2365 // | || /
2366 // | AddP (array's element offset)
2367 // | |
2368 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2369 // | / /
2370 // AddP (array's offset)
2371 // |
2372 // Load/Store (memory operation on array's element)
2373 //
2374 return addp2;
2375 }
2376 return NULL;
2377 }
2378
2379 //
2380 // Adjust the type and inputs of an AddP which computes the
2381 // address of a field of an instance
2382 //
2383 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2384 PhaseGVN* igvn = _igvn;
2385 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2386 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2387 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2388 if (t == NULL) {
2389 // We are computing a raw address for a store captured by an Initialize
2390 // compute an appropriate address type (cases #3 and #5).
2391 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2392 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2393 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2394 assert(offs != Type::OffsetBot, "offset must be a constant");
2395 t = base_t->add_offset(offs)->is_oopptr();
2396 }
2397 int inst_id = base_t->instance_id();
2398 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2399 "old type must be non-instance or match new type");
2400
2401 // The type 't' could be subclass of 'base_t'.
2402 // As result t->offset() could be large then base_t's size and it will
2403 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2404 // constructor verifies correctness of the offset.
2405 //
2406 // It could happened on subclass's branch (from the type profiling
2407 // inlining) which was not eliminated during parsing since the exactness
2408 // of the allocation type was not propagated to the subclass type check.
2409 //
2410 // Or the type 't' could be not related to 'base_t' at all.
2411 // It could happened when CHA type is different from MDO type on a dead path
2412 // (for example, from instanceof check) which is not collapsed during parsing.
2413 //
2414 // Do nothing for such AddP node and don't process its users since
2415 // this code branch will go away.
2416 //
2417 if (!t->is_known_instance() &&
2418 !base_t->klass()->is_subtype_of(t->klass())) {
2419 return false; // bail out
2420 }
2421 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2422 // Do NOT remove the next line: ensure a new alias index is allocated
2423 // for the instance type. Note: C++ will not remove it since the call
2424 // has side effect.
2425 int alias_idx = _compile->get_alias_index(tinst);
2426 igvn->set_type(addp, tinst);
2427 // record the allocation in the node map
2428 set_map(addp, get_map(base->_idx));
2429 // Set addp's Base and Address to 'base'.
2430 Node *abase = addp->in(AddPNode::Base);
2431 Node *adr = addp->in(AddPNode::Address);
2432 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2433 adr->in(0)->_idx == (uint)inst_id) {
2434 // Skip AddP cases #3 and #5.
2435 } else {
2436 assert(!abase->is_top(), "sanity"); // AddP case #3
2437 if (abase != base) {
2438 igvn->hash_delete(addp);
2439 addp->set_req(AddPNode::Base, base);
2440 if (abase == adr) {
2441 addp->set_req(AddPNode::Address, base);
2442 } else {
2443 // AddP case #4 (adr is array's element offset AddP node)
2444 #ifdef ASSERT
2445 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2446 assert(adr->is_AddP() && atype != NULL &&
2447 atype->instance_id() == inst_id, "array's element offset should be processed first");
2448 #endif
2449 }
2450 igvn->hash_insert(addp);
2451 }
2452 }
2453 // Put on IGVN worklist since at least addp's type was changed above.
2454 record_for_optimizer(addp);
2455 return true;
2456 }
2457
2458 //
2459 // Create a new version of orig_phi if necessary. Returns either the newly
2460 // created phi or an existing phi. Sets create_new to indicate whether a new
2461 // phi was created. Cache the last newly created phi in the node map.
2462 //
2463 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2464 Compile *C = _compile;
2465 PhaseGVN* igvn = _igvn;
2466 new_created = false;
2467 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2468 // nothing to do if orig_phi is bottom memory or matches alias_idx
2469 if (phi_alias_idx == alias_idx) {
2470 return orig_phi;
2471 }
2472 // Have we recently created a Phi for this alias index?
2473 PhiNode *result = get_map_phi(orig_phi->_idx);
2474 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2475 return result;
2476 }
2477 // Previous check may fail when the same wide memory Phi was split into Phis
2478 // for different memory slices. Search all Phis for this region.
2479 if (result != NULL) {
2480 Node* region = orig_phi->in(0);
2481 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2482 Node* phi = region->fast_out(i);
2483 if (phi->is_Phi() &&
2484 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2485 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2486 return phi->as_Phi();
2487 }
2488 }
2489 }
2490 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2491 if (C->do_escape_analysis() == true && !C->failing()) {
2492 // Retry compilation without escape analysis.
2493 // If this is the first failure, the sentinel string will "stick"
2494 // to the Compile object, and the C2Compiler will see it and retry.
2495 C->record_failure(C2Compiler::retry_no_escape_analysis());
2496 }
2497 return NULL;
2498 }
2499 orig_phi_worklist.append_if_missing(orig_phi);
2500 const TypePtr *atype = C->get_adr_type(alias_idx);
2501 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2502 C->copy_node_notes_to(result, orig_phi);
2503 igvn->set_type(result, result->bottom_type());
2504 record_for_optimizer(result);
2505 set_map(orig_phi, result);
2506 new_created = true;
2507 return result;
2508 }
2509
2510 //
2511 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2512 // specified alias index.
2513 //
2514 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2515 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2516 Compile *C = _compile;
2517 PhaseGVN* igvn = _igvn;
2518 bool new_phi_created;
2519 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2520 if (!new_phi_created) {
2521 return result;
2522 }
2523 GrowableArray<PhiNode *> phi_list;
2524 GrowableArray<uint> cur_input;
2525 PhiNode *phi = orig_phi;
2526 uint idx = 1;
2527 bool finished = false;
2528 while(!finished) {
2529 while (idx < phi->req()) {
2530 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2531 if (mem != NULL && mem->is_Phi()) {
2532 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2533 if (new_phi_created) {
2534 // found an phi for which we created a new split, push current one on worklist and begin
2535 // processing new one
2536 phi_list.push(phi);
2537 cur_input.push(idx);
2538 phi = mem->as_Phi();
2539 result = newphi;
2540 idx = 1;
2541 continue;
2542 } else {
2543 mem = newphi;
2544 }
2545 }
2546 if (C->failing()) {
2547 return NULL;
2548 }
2549 result->set_req(idx++, mem);
2550 }
2551 #ifdef ASSERT
2552 // verify that the new Phi has an input for each input of the original
2553 assert( phi->req() == result->req(), "must have same number of inputs.");
2554 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2555 #endif
2556 // Check if all new phi's inputs have specified alias index.
2557 // Otherwise use old phi.
2558 for (uint i = 1; i < phi->req(); i++) {
2559 Node* in = result->in(i);
2560 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2561 }
2562 // we have finished processing a Phi, see if there are any more to do
2563 finished = (phi_list.length() == 0 );
2564 if (!finished) {
2565 phi = phi_list.pop();
2566 idx = cur_input.pop();
2567 PhiNode *prev_result = get_map_phi(phi->_idx);
2568 prev_result->set_req(idx++, result);
2569 result = prev_result;
2570 }
2571 }
2572 return result;
2573 }
2574
2575 //
2576 // The next methods are derived from methods in MemNode.
2577 //
2578 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2579 Node *mem = mmem;
2580 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2581 // means an array I have not precisely typed yet. Do not do any
2582 // alias stuff with it any time soon.
2583 if (toop->base() != Type::AnyPtr &&
2584 !(toop->klass() != NULL &&
2585 toop->klass()->is_java_lang_Object() &&
2586 toop->offset() == Type::OffsetBot)) {
2587 mem = mmem->memory_at(alias_idx);
2588 // Update input if it is progress over what we have now
2589 }
2590 return mem;
2591 }
2592
2593 //
2594 // Move memory users to their memory slices.
2595 //
2596 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2597 Compile* C = _compile;
2598 PhaseGVN* igvn = _igvn;
2599 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2600 assert(tp != NULL, "ptr type");
2601 int alias_idx = C->get_alias_index(tp);
2602 int general_idx = C->get_general_index(alias_idx);
2603
2604 // Move users first
2605 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2606 Node* use = n->fast_out(i);
2607 if (use->is_MergeMem()) {
2608 MergeMemNode* mmem = use->as_MergeMem();
2609 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2610 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2611 continue; // Nothing to do
2612 }
2613 // Replace previous general reference to mem node.
2614 uint orig_uniq = C->unique();
2615 Node* m = find_inst_mem(n, general_idx, orig_phis);
2616 assert(orig_uniq == C->unique(), "no new nodes");
2617 mmem->set_memory_at(general_idx, m);
2618 --imax;
2619 --i;
2620 } else if (use->is_MemBar()) {
2621 assert(!use->is_Initialize(), "initializing stores should not be moved");
2622 if (use->req() > MemBarNode::Precedent &&
2623 use->in(MemBarNode::Precedent) == n) {
2624 // Don't move related membars.
2625 record_for_optimizer(use);
2626 continue;
2627 }
2628 tp = use->as_MemBar()->adr_type()->isa_ptr();
2629 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2630 alias_idx == general_idx) {
2631 continue; // Nothing to do
2632 }
2633 // Move to general memory slice.
2634 uint orig_uniq = C->unique();
2635 Node* m = find_inst_mem(n, general_idx, orig_phis);
2636 assert(orig_uniq == C->unique(), "no new nodes");
2637 igvn->hash_delete(use);
2638 imax -= use->replace_edge(n, m);
2639 igvn->hash_insert(use);
2640 record_for_optimizer(use);
2641 --i;
2642 #ifdef ASSERT
2643 } else if (use->is_Mem()) {
2644 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2645 // Don't move related cardmark.
2646 continue;
2647 }
2648 // Memory nodes should have new memory input.
2649 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2650 assert(tp != NULL, "ptr type");
2651 int idx = C->get_alias_index(tp);
2652 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2653 "Following memory nodes should have new memory input or be on the same memory slice");
2654 } else if (use->is_Phi()) {
2655 // Phi nodes should be split and moved already.
2656 tp = use->as_Phi()->adr_type()->isa_ptr();
2657 assert(tp != NULL, "ptr type");
2658 int idx = C->get_alias_index(tp);
2659 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2660 } else {
2661 use->dump();
2662 assert(false, "should not be here");
2663 #endif
2664 }
2665 }
2666 }
2667
2668 //
2669 // Search memory chain of "mem" to find a MemNode whose address
2670 // is the specified alias index.
2671 //
2672 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2673 if (orig_mem == NULL)
2674 return orig_mem;
2675 Compile* C = _compile;
2676 PhaseGVN* igvn = _igvn;
2677 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2678 bool is_instance = (toop != NULL) && toop->is_known_instance();
2679 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2680 Node *prev = NULL;
2681 Node *result = orig_mem;
2682 while (prev != result) {
2683 prev = result;
2684 if (result == start_mem)
2685 break; // hit one of our sentinels
2686 if (result->is_Mem()) {
2687 const Type *at = igvn->type(result->in(MemNode::Address));
2688 if (at == Type::TOP)
2689 break; // Dead
2690 assert (at->isa_ptr() != NULL, "pointer type required.");
2691 int idx = C->get_alias_index(at->is_ptr());
2692 if (idx == alias_idx)
2693 break; // Found
2694 if (!is_instance && (at->isa_oopptr() == NULL ||
2695 !at->is_oopptr()->is_known_instance())) {
2696 break; // Do not skip store to general memory slice.
2697 }
2698 result = result->in(MemNode::Memory);
2699 }
2700 if (!is_instance)
2701 continue; // don't search further for non-instance types
2702 // skip over a call which does not affect this memory slice
2703 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2704 Node *proj_in = result->in(0);
2705 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2706 break; // hit one of our sentinels
2707 } else if (proj_in->is_Call()) {
2708 // ArrayCopy node processed here as well
2709 CallNode *call = proj_in->as_Call();
2710 if (!call->may_modify(toop, igvn)) {
2711 result = call->in(TypeFunc::Memory);
2712 }
2713 } else if (proj_in->is_Initialize()) {
2714 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2715 // Stop if this is the initialization for the object instance which
2716 // which contains this memory slice, otherwise skip over it.
2717 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2718 result = proj_in->in(TypeFunc::Memory);
2719 }
2720 } else if (proj_in->is_MemBar()) {
2721 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2722 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2723 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2724 // clone
2725 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2726 if (ac->may_modify(toop, igvn)) {
2727 break;
2728 }
2729 }
2730 result = proj_in->in(TypeFunc::Memory);
2731 }
2732 } else if (result->is_MergeMem()) {
2733 MergeMemNode *mmem = result->as_MergeMem();
2734 result = step_through_mergemem(mmem, alias_idx, toop);
2735 if (result == mmem->base_memory()) {
2736 // Didn't find instance memory, search through general slice recursively.
2737 result = mmem->memory_at(C->get_general_index(alias_idx));
2738 result = find_inst_mem(result, alias_idx, orig_phis);
2739 if (C->failing()) {
2740 return NULL;
2741 }
2742 mmem->set_memory_at(alias_idx, result);
2743 }
2744 } else if (result->is_Phi() &&
2745 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2746 Node *un = result->as_Phi()->unique_input(igvn);
2747 if (un != NULL) {
2748 orig_phis.append_if_missing(result->as_Phi());
2749 result = un;
2750 } else {
2751 break;
2752 }
2753 } else if (result->is_ClearArray()) {
2754 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2755 // Can not bypass initialization of the instance
2756 // we are looking for.
2757 break;
2758 }
2759 // Otherwise skip it (the call updated 'result' value).
2760 } else if (result->Opcode() == Op_SCMemProj) {
2761 Node* mem = result->in(0);
2762 Node* adr = NULL;
2763 if (mem->is_LoadStore()) {
2764 adr = mem->in(MemNode::Address);
2765 } else {
2766 assert(mem->Opcode() == Op_EncodeISOArray ||
2767 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2768 adr = mem->in(3); // Memory edge corresponds to destination array
2769 }
2770 const Type *at = igvn->type(adr);
2771 if (at != Type::TOP) {
2772 assert(at->isa_ptr() != NULL, "pointer type required.");
2773 int idx = C->get_alias_index(at->is_ptr());
2774 if (idx == alias_idx) {
2775 // Assert in debug mode
2776 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2777 break; // In product mode return SCMemProj node
2778 }
2779 }
2780 result = mem->in(MemNode::Memory);
2781 } else if (result->Opcode() == Op_StrInflatedCopy) {
2782 Node* adr = result->in(3); // Memory edge corresponds to destination array
2783 const Type *at = igvn->type(adr);
2784 if (at != Type::TOP) {
2785 assert(at->isa_ptr() != NULL, "pointer type required.");
2786 int idx = C->get_alias_index(at->is_ptr());
2787 if (idx == alias_idx) {
2788 // Assert in debug mode
2789 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2790 break; // In product mode return SCMemProj node
2791 }
2792 }
2793 result = result->in(MemNode::Memory);
2794 }
2795 }
2796 if (result->is_Phi()) {
2797 PhiNode *mphi = result->as_Phi();
2798 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2799 const TypePtr *t = mphi->adr_type();
2800 if (!is_instance) {
2801 // Push all non-instance Phis on the orig_phis worklist to update inputs
2802 // during Phase 4 if needed.
2803 orig_phis.append_if_missing(mphi);
2804 } else if (C->get_alias_index(t) != alias_idx) {
2805 // Create a new Phi with the specified alias index type.
2806 result = split_memory_phi(mphi, alias_idx, orig_phis);
2807 }
2808 }
2809 // the result is either MemNode, PhiNode, InitializeNode.
2810 return result;
2811 }
2812
2813 //
2814 // Convert the types of unescaped object to instance types where possible,
2815 // propagate the new type information through the graph, and update memory
2816 // edges and MergeMem inputs to reflect the new type.
2817 //
2818 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2819 // The processing is done in 4 phases:
2820 //
2821 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2822 // types for the CheckCastPP for allocations where possible.
2823 // Propagate the new types through users as follows:
2824 // casts and Phi: push users on alloc_worklist
2825 // AddP: cast Base and Address inputs to the instance type
2826 // push any AddP users on alloc_worklist and push any memnode
2827 // users onto memnode_worklist.
2828 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2829 // search the Memory chain for a store with the appropriate type
2830 // address type. If a Phi is found, create a new version with
2831 // the appropriate memory slices from each of the Phi inputs.
2832 // For stores, process the users as follows:
2833 // MemNode: push on memnode_worklist
2834 // MergeMem: push on mergemem_worklist
2835 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2836 // moving the first node encountered of each instance type to the
2837 // the input corresponding to its alias index.
2838 // appropriate memory slice.
2839 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2840 //
2841 // In the following example, the CheckCastPP nodes are the cast of allocation
2842 // results and the allocation of node 29 is unescaped and eligible to be an
2843 // instance type.
2844 //
2845 // We start with:
2846 //
2847 // 7 Parm #memory
2848 // 10 ConI "12"
2849 // 19 CheckCastPP "Foo"
2850 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2851 // 29 CheckCastPP "Foo"
2852 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2853 //
2854 // 40 StoreP 25 7 20 ... alias_index=4
2855 // 50 StoreP 35 40 30 ... alias_index=4
2856 // 60 StoreP 45 50 20 ... alias_index=4
2857 // 70 LoadP _ 60 30 ... alias_index=4
2858 // 80 Phi 75 50 60 Memory alias_index=4
2859 // 90 LoadP _ 80 30 ... alias_index=4
2860 // 100 LoadP _ 80 20 ... alias_index=4
2861 //
2862 //
2863 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2864 // and creating a new alias index for node 30. This gives:
2865 //
2866 // 7 Parm #memory
2867 // 10 ConI "12"
2868 // 19 CheckCastPP "Foo"
2869 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2870 // 29 CheckCastPP "Foo" iid=24
2871 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2872 //
2873 // 40 StoreP 25 7 20 ... alias_index=4
2874 // 50 StoreP 35 40 30 ... alias_index=6
2875 // 60 StoreP 45 50 20 ... alias_index=4
2876 // 70 LoadP _ 60 30 ... alias_index=6
2877 // 80 Phi 75 50 60 Memory alias_index=4
2878 // 90 LoadP _ 80 30 ... alias_index=6
2879 // 100 LoadP _ 80 20 ... alias_index=4
2880 //
2881 // In phase 2, new memory inputs are computed for the loads and stores,
2882 // And a new version of the phi is created. In phase 4, the inputs to
2883 // node 80 are updated and then the memory nodes are updated with the
2884 // values computed in phase 2. This results in:
2885 //
2886 // 7 Parm #memory
2887 // 10 ConI "12"
2888 // 19 CheckCastPP "Foo"
2889 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2890 // 29 CheckCastPP "Foo" iid=24
2891 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2892 //
2893 // 40 StoreP 25 7 20 ... alias_index=4
2894 // 50 StoreP 35 7 30 ... alias_index=6
2895 // 60 StoreP 45 40 20 ... alias_index=4
2896 // 70 LoadP _ 50 30 ... alias_index=6
2897 // 80 Phi 75 40 60 Memory alias_index=4
2898 // 120 Phi 75 50 50 Memory alias_index=6
2899 // 90 LoadP _ 120 30 ... alias_index=6
2900 // 100 LoadP _ 80 20 ... alias_index=4
2901 //
2902 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2903 GrowableArray<Node *> memnode_worklist;
2904 GrowableArray<PhiNode *> orig_phis;
2905 PhaseIterGVN *igvn = _igvn;
2906 uint new_index_start = (uint) _compile->num_alias_types();
2907 Arena* arena = Thread::current()->resource_area();
2908 VectorSet visited(arena);
2909 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2910 uint unique_old = _compile->unique();
2911
2912 // Phase 1: Process possible allocations from alloc_worklist.
2913 // Create instance types for the CheckCastPP for allocations where possible.
2914 //
2915 // (Note: don't forget to change the order of the second AddP node on
2916 // the alloc_worklist if the order of the worklist processing is changed,
2917 // see the comment in find_second_addp().)
2918 //
2919 while (alloc_worklist.length() != 0) {
2920 Node *n = alloc_worklist.pop();
2921 uint ni = n->_idx;
2922 if (n->is_Call()) {
2923 CallNode *alloc = n->as_Call();
2924 // copy escape information to call node
2925 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2926 PointsToNode::EscapeState es = ptn->escape_state();
2927 // We have an allocation or call which returns a Java object,
2928 // see if it is unescaped.
2929 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2930 continue;
2931 // Find CheckCastPP for the allocate or for the return value of a call
2932 n = alloc->result_cast();
2933 if (n == NULL) { // No uses except Initialize node
2934 if (alloc->is_Allocate()) {
2935 // Set the scalar_replaceable flag for allocation
2936 // so it could be eliminated if it has no uses.
2937 alloc->as_Allocate()->_is_scalar_replaceable = true;
2938 }
2939 if (alloc->is_CallStaticJava()) {
2940 // Set the scalar_replaceable flag for boxing method
2941 // so it could be eliminated if it has no uses.
2942 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2943 }
2944 continue;
2945 }
2946 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2947 assert(!alloc->is_Allocate(), "allocation should have unique type");
2948 continue;
2949 }
2950
2951 // The inline code for Object.clone() casts the allocation result to
2952 // java.lang.Object and then to the actual type of the allocated
2953 // object. Detect this case and use the second cast.
2954 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2955 // the allocation result is cast to java.lang.Object and then
2956 // to the actual Array type.
2957 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2958 && (alloc->is_AllocateArray() ||
2959 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2960 Node *cast2 = NULL;
2961 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2962 Node *use = n->fast_out(i);
2963 if (use->is_CheckCastPP()) {
2964 cast2 = use;
2965 break;
2966 }
2967 }
2968 if (cast2 != NULL) {
2969 n = cast2;
2970 } else {
2971 // Non-scalar replaceable if the allocation type is unknown statically
2972 // (reflection allocation), the object can't be restored during
2973 // deoptimization without precise type.
2974 continue;
2975 }
2976 }
2977
2978 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2979 if (t == NULL)
2980 continue; // not a TypeOopPtr
2981 if (!t->klass_is_exact())
2982 continue; // not an unique type
2983
2984 if (alloc->is_Allocate()) {
2985 // Set the scalar_replaceable flag for allocation
2986 // so it could be eliminated.
2987 alloc->as_Allocate()->_is_scalar_replaceable = true;
2988 }
2989 if (alloc->is_CallStaticJava()) {
2990 // Set the scalar_replaceable flag for boxing method
2991 // so it could be eliminated.
2992 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2993 }
2994 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2995 // in order for an object to be scalar-replaceable, it must be:
2996 // - a direct allocation (not a call returning an object)
2997 // - non-escaping
2998 // - eligible to be a unique type
2999 // - not determined to be ineligible by escape analysis
3000 set_map(alloc, n);
3001 set_map(n, alloc);
3002 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3003 igvn->hash_delete(n);
3004 igvn->set_type(n, tinst);
3005 n->raise_bottom_type(tinst);
3006 igvn->hash_insert(n);
3007 record_for_optimizer(n);
3008 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3009
3010 // First, put on the worklist all Field edges from Connection Graph
3011 // which is more accurate than putting immediate users from Ideal Graph.
3012 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3013 PointsToNode* tgt = e.get();
3014 if (tgt->is_Arraycopy()) {
3015 continue;
3016 }
3017 Node* use = tgt->ideal_node();
3018 assert(tgt->is_Field() && use->is_AddP(),
3019 "only AddP nodes are Field edges in CG");
3020 if (use->outcnt() > 0) { // Don't process dead nodes
3021 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3022 if (addp2 != NULL) {
3023 assert(alloc->is_AllocateArray(),"array allocation was expected");
3024 alloc_worklist.append_if_missing(addp2);
3025 }
3026 alloc_worklist.append_if_missing(use);
3027 }
3028 }
3029
3030 // An allocation may have an Initialize which has raw stores. Scan
3031 // the users of the raw allocation result and push AddP users
3032 // on alloc_worklist.
3033 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3034 assert (raw_result != NULL, "must have an allocation result");
3035 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3036 Node *use = raw_result->fast_out(i);
3037 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3038 Node* addp2 = find_second_addp(use, raw_result);
3039 if (addp2 != NULL) {
3040 assert(alloc->is_AllocateArray(),"array allocation was expected");
3041 alloc_worklist.append_if_missing(addp2);
3042 }
3043 alloc_worklist.append_if_missing(use);
3044 } else if (use->is_MemBar()) {
3045 memnode_worklist.append_if_missing(use);
3046 }
3047 }
3048 }
3049 } else if (n->is_AddP()) {
3050 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3051 if (jobj == NULL || jobj == phantom_obj) {
3052 #ifdef ASSERT
3053 ptnode_adr(get_addp_base(n)->_idx)->dump();
3054 ptnode_adr(n->_idx)->dump();
3055 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3056 #endif
3057 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3058 return;
3059 }
3060 Node *base = get_map(jobj->idx()); // CheckCastPP node
3061 if (!split_AddP(n, base)) continue; // wrong type from dead path
3062 } else if (n->is_Phi() ||
3063 n->is_CheckCastPP() ||
3064 n->is_EncodeP() ||
3065 n->is_DecodeN() ||
3066 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3067 if (visited.test_set(n->_idx)) {
3068 assert(n->is_Phi(), "loops only through Phi's");
3069 continue; // already processed
3070 }
3071 JavaObjectNode* jobj = unique_java_object(n);
3072 if (jobj == NULL || jobj == phantom_obj) {
3073 #ifdef ASSERT
3074 ptnode_adr(n->_idx)->dump();
3075 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3076 #endif
3077 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3078 return;
3079 } else {
3080 Node *val = get_map(jobj->idx()); // CheckCastPP node
3081 TypeNode *tn = n->as_Type();
3082 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3083 assert(tinst != NULL && tinst->is_known_instance() &&
3084 tinst->instance_id() == jobj->idx() , "instance type expected.");
3085
3086 const Type *tn_type = igvn->type(tn);
3087 const TypeOopPtr *tn_t;
3088 if (tn_type->isa_narrowoop()) {
3089 tn_t = tn_type->make_ptr()->isa_oopptr();
3090 } else {
3091 tn_t = tn_type->isa_oopptr();
3092 }
3093 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3094 if (tn_type->isa_narrowoop()) {
3095 tn_type = tinst->make_narrowoop();
3096 } else {
3097 tn_type = tinst;
3098 }
3099 igvn->hash_delete(tn);
3100 igvn->set_type(tn, tn_type);
3101 tn->set_type(tn_type);
3102 igvn->hash_insert(tn);
3103 record_for_optimizer(n);
3104 } else {
3105 assert(tn_type == TypePtr::NULL_PTR ||
3106 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3107 "unexpected type");
3108 continue; // Skip dead path with different type
3109 }
3110 }
3111 } else {
3112 debug_only(n->dump();)
3113 assert(false, "EA: unexpected node");
3114 continue;
3115 }
3116 // push allocation's users on appropriate worklist
3117 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3118 Node *use = n->fast_out(i);
3119 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3120 // Load/store to instance's field
3121 memnode_worklist.append_if_missing(use);
3122 } else if (use->is_MemBar()) {
3123 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3124 memnode_worklist.append_if_missing(use);
3125 }
3126 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3127 Node* addp2 = find_second_addp(use, n);
3128 if (addp2 != NULL) {
3129 alloc_worklist.append_if_missing(addp2);
3130 }
3131 alloc_worklist.append_if_missing(use);
3132 } else if (use->is_Phi() ||
3133 use->is_CheckCastPP() ||
3134 use->is_EncodeNarrowPtr() ||
3135 use->is_DecodeNarrowPtr() ||
3136 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3137 alloc_worklist.append_if_missing(use);
3138 #ifdef ASSERT
3139 } else if (use->is_Mem()) {
3140 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3141 } else if (use->is_MergeMem()) {
3142 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3143 } else if (use->is_SafePoint()) {
3144 // Look for MergeMem nodes for calls which reference unique allocation
3145 // (through CheckCastPP nodes) even for debug info.
3146 Node* m = use->in(TypeFunc::Memory);
3147 if (m->is_MergeMem()) {
3148 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3149 }
3150 } else if (use->Opcode() == Op_EncodeISOArray) {
3151 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3152 // EncodeISOArray overwrites destination array
3153 memnode_worklist.append_if_missing(use);
3154 }
3155 } else {
3156 uint op = use->Opcode();
3157 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3158 (use->in(MemNode::Memory) == n)) {
3159 // They overwrite memory edge corresponding to destination array,
3160 memnode_worklist.append_if_missing(use);
3161 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3162 op == Op_CastP2X || op == Op_StoreCM ||
3163 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3164 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3165 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3166 n->dump();
3167 use->dump();
3168 assert(false, "EA: missing allocation reference path");
3169 }
3170 #endif
3171 }
3172 }
3173
3174 }
3175
3176 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3177 // type, record it in the ArrayCopy node so we know what memory this
3178 // node uses/modified.
3179 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3180 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3181 Node* dest = ac->in(ArrayCopyNode::Dest);
3182 if (dest->is_AddP()) {
3183 dest = get_addp_base(dest);
3184 }
3185 JavaObjectNode* jobj = unique_java_object(dest);
3186 if (jobj != NULL) {
3187 Node *base = get_map(jobj->idx());
3188 if (base != NULL) {
3189 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3190 ac->_dest_type = base_t;
3191 }
3192 }
3193 Node* src = ac->in(ArrayCopyNode::Src);
3194 if (src->is_AddP()) {
3195 src = get_addp_base(src);
3196 }
3197 jobj = unique_java_object(src);
3198 if (jobj != NULL) {
3199 Node* base = get_map(jobj->idx());
3200 if (base != NULL) {
3201 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3202 ac->_src_type = base_t;
3203 }
3204 }
3205 }
3206
3207 // New alias types were created in split_AddP().
3208 uint new_index_end = (uint) _compile->num_alias_types();
3209 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3210
3211 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3212 // compute new values for Memory inputs (the Memory inputs are not
3213 // actually updated until phase 4.)
3214 if (memnode_worklist.length() == 0)
3215 return; // nothing to do
3216 while (memnode_worklist.length() != 0) {
3217 Node *n = memnode_worklist.pop();
3218 if (visited.test_set(n->_idx))
3219 continue;
3220 if (n->is_Phi() || n->is_ClearArray()) {
3221 // we don't need to do anything, but the users must be pushed
3222 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3223 // we don't need to do anything, but the users must be pushed
3224 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3225 if (n == NULL)
3226 continue;
3227 } else if (n->Opcode() == Op_StrCompressedCopy ||
3228 n->Opcode() == Op_EncodeISOArray) {
3229 // get the memory projection
3230 n = n->find_out_with(Op_SCMemProj);
3231 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3232 } else {
3233 assert(n->is_Mem(), "memory node required.");
3234 Node *addr = n->in(MemNode::Address);
3235 const Type *addr_t = igvn->type(addr);
3236 if (addr_t == Type::TOP)
3237 continue;
3238 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3239 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3240 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3241 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3242 if (_compile->failing()) {
3243 return;
3244 }
3245 if (mem != n->in(MemNode::Memory)) {
3246 // We delay the memory edge update since we need old one in
3247 // MergeMem code below when instances memory slices are separated.
3248 set_map(n, mem);
3249 }
3250 if (n->is_Load()) {
3251 continue; // don't push users
3252 } else if (n->is_LoadStore()) {
3253 // get the memory projection
3254 n = n->find_out_with(Op_SCMemProj);
3255 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3256 }
3257 }
3258 // push user on appropriate worklist
3259 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3260 Node *use = n->fast_out(i);
3261 if (use->is_Phi() || use->is_ClearArray()) {
3262 memnode_worklist.append_if_missing(use);
3263 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3264 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3265 continue;
3266 memnode_worklist.append_if_missing(use);
3267 } else if (use->is_MemBar()) {
3268 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3269 memnode_worklist.append_if_missing(use);
3270 }
3271 #ifdef ASSERT
3272 } else if(use->is_Mem()) {
3273 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3274 } else if (use->is_MergeMem()) {
3275 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3276 } else if (use->Opcode() == Op_EncodeISOArray) {
3277 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3278 // EncodeISOArray overwrites destination array
3279 memnode_worklist.append_if_missing(use);
3280 }
3281 } else {
3282 uint op = use->Opcode();
3283 if ((use->in(MemNode::Memory) == n) &&
3284 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3285 // They overwrite memory edge corresponding to destination array,
3286 memnode_worklist.append_if_missing(use);
3287 } else if (!(op == Op_StoreCM ||
3288 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3289 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3290 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3291 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3292 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3293 n->dump();
3294 use->dump();
3295 assert(false, "EA: missing memory path");
3296 }
3297 #endif
3298 }
3299 }
3300 }
3301
3302 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3303 // Walk each memory slice moving the first node encountered of each
3304 // instance type to the the input corresponding to its alias index.
3305 uint length = _mergemem_worklist.length();
3306 for( uint next = 0; next < length; ++next ) {
3307 MergeMemNode* nmm = _mergemem_worklist.at(next);
3308 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3309 // Note: we don't want to use MergeMemStream here because we only want to
3310 // scan inputs which exist at the start, not ones we add during processing.
3311 // Note 2: MergeMem may already contains instance memory slices added
3312 // during find_inst_mem() call when memory nodes were processed above.
3313 igvn->hash_delete(nmm);
3314 uint nslices = MIN2(nmm->req(), new_index_start);
3315 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3316 Node* mem = nmm->in(i);
3317 Node* cur = NULL;
3318 if (mem == NULL || mem->is_top())
3319 continue;
3320 // First, update mergemem by moving memory nodes to corresponding slices
3321 // if their type became more precise since this mergemem was created.
3322 while (mem->is_Mem()) {
3323 const Type *at = igvn->type(mem->in(MemNode::Address));
3324 if (at != Type::TOP) {
3325 assert (at->isa_ptr() != NULL, "pointer type required.");
3326 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3327 if (idx == i) {
3328 if (cur == NULL)
3329 cur = mem;
3330 } else {
3331 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3332 nmm->set_memory_at(idx, mem);
3333 }
3334 }
3335 }
3336 mem = mem->in(MemNode::Memory);
3337 }
3338 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3339 // Find any instance of the current type if we haven't encountered
3340 // already a memory slice of the instance along the memory chain.
3341 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3342 if((uint)_compile->get_general_index(ni) == i) {
3343 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3344 if (nmm->is_empty_memory(m)) {
3345 Node* result = find_inst_mem(mem, ni, orig_phis);
3346 if (_compile->failing()) {
3347 return;
3348 }
3349 nmm->set_memory_at(ni, result);
3350 }
3351 }
3352 }
3353 }
3354 // Find the rest of instances values
3355 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3356 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3357 Node* result = step_through_mergemem(nmm, ni, tinst);
3358 if (result == nmm->base_memory()) {
3359 // Didn't find instance memory, search through general slice recursively.
3360 result = nmm->memory_at(_compile->get_general_index(ni));
3361 result = find_inst_mem(result, ni, orig_phis);
3362 if (_compile->failing()) {
3363 return;
3364 }
3365 nmm->set_memory_at(ni, result);
3366 }
3367 }
3368 igvn->hash_insert(nmm);
3369 record_for_optimizer(nmm);
3370 }
3371
3372 // Phase 4: Update the inputs of non-instance memory Phis and
3373 // the Memory input of memnodes
3374 // First update the inputs of any non-instance Phi's from
3375 // which we split out an instance Phi. Note we don't have
3376 // to recursively process Phi's encounted on the input memory
3377 // chains as is done in split_memory_phi() since they will
3378 // also be processed here.
3379 for (int j = 0; j < orig_phis.length(); j++) {
3380 PhiNode *phi = orig_phis.at(j);
3381 int alias_idx = _compile->get_alias_index(phi->adr_type());
3382 igvn->hash_delete(phi);
3383 for (uint i = 1; i < phi->req(); i++) {
3384 Node *mem = phi->in(i);
3385 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3386 if (_compile->failing()) {
3387 return;
3388 }
3389 if (mem != new_mem) {
3390 phi->set_req(i, new_mem);
3391 }
3392 }
3393 igvn->hash_insert(phi);
3394 record_for_optimizer(phi);
3395 }
3396
3397 // Update the memory inputs of MemNodes with the value we computed
3398 // in Phase 2 and move stores memory users to corresponding memory slices.
3399 // Disable memory split verification code until the fix for 6984348.
3400 // Currently it produces false negative results since it does not cover all cases.
3401 #if 0 // ifdef ASSERT
3402 visited.Reset();
3403 Node_Stack old_mems(arena, _compile->unique() >> 2);
3404 #endif
3405 for (uint i = 0; i < ideal_nodes.size(); i++) {
3406 Node* n = ideal_nodes.at(i);
3407 Node* nmem = get_map(n->_idx);
3408 assert(nmem != NULL, "sanity");
3409 if (n->is_Mem()) {
3410 #if 0 // ifdef ASSERT
3411 Node* old_mem = n->in(MemNode::Memory);
3412 if (!visited.test_set(old_mem->_idx)) {
3413 old_mems.push(old_mem, old_mem->outcnt());
3414 }
3415 #endif
3416 assert(n->in(MemNode::Memory) != nmem, "sanity");
3417 if (!n->is_Load()) {
3418 // Move memory users of a store first.
3419 move_inst_mem(n, orig_phis);
3420 }
3421 // Now update memory input
3422 igvn->hash_delete(n);
3423 n->set_req(MemNode::Memory, nmem);
3424 igvn->hash_insert(n);
3425 record_for_optimizer(n);
3426 } else {
3427 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3428 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3429 }
3430 }
3431 #if 0 // ifdef ASSERT
3432 // Verify that memory was split correctly
3433 while (old_mems.is_nonempty()) {
3434 Node* old_mem = old_mems.node();
3435 uint old_cnt = old_mems.index();
3436 old_mems.pop();
3437 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3438 }
3439 #endif
3440 }
3441
3442 #ifndef PRODUCT
3443 static const char *node_type_names[] = {
3444 "UnknownType",
3445 "JavaObject",
3446 "LocalVar",
3447 "Field",
3448 "Arraycopy"
3449 };
3450
3451 static const char *esc_names[] = {
3452 "UnknownEscape",
3453 "NoEscape",
3454 "ArgEscape",
3455 "GlobalEscape"
3456 };
3457
3458 void PointsToNode::dump(bool print_state) const {
3459 NodeType nt = node_type();
3460 tty->print("%s ", node_type_names[(int) nt]);
3461 if (print_state) {
3462 EscapeState es = escape_state();
3463 EscapeState fields_es = fields_escape_state();
3464 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3465 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3466 tty->print("NSR ");
3467 }
3468 if (is_Field()) {
3469 FieldNode* f = (FieldNode*)this;
3470 if (f->is_oop())
3471 tty->print("oop ");
3472 if (f->offset() > 0)
3473 tty->print("+%d ", f->offset());
3474 tty->print("(");
3475 for (BaseIterator i(f); i.has_next(); i.next()) {
3476 PointsToNode* b = i.get();
3477 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3478 }
3479 tty->print(" )");
3480 }
3481 tty->print("[");
3482 for (EdgeIterator i(this); i.has_next(); i.next()) {
3483 PointsToNode* e = i.get();
3484 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3485 }
3486 tty->print(" [");
3487 for (UseIterator i(this); i.has_next(); i.next()) {
3488 PointsToNode* u = i.get();
3489 bool is_base = false;
3490 if (PointsToNode::is_base_use(u)) {
3491 is_base = true;
3492 u = PointsToNode::get_use_node(u)->as_Field();
3493 }
3494 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3495 }
3496 tty->print(" ]] ");
3497 if (_node == NULL)
3498 tty->print_cr("<null>");
3499 else
3500 _node->dump();
3501 }
3502
3503 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3504 bool first = true;
3505 int ptnodes_length = ptnodes_worklist.length();
3506 for (int i = 0; i < ptnodes_length; i++) {
3507 PointsToNode *ptn = ptnodes_worklist.at(i);
3508 if (ptn == NULL || !ptn->is_JavaObject())
3509 continue;
3510 PointsToNode::EscapeState es = ptn->escape_state();
3511 if ((es != PointsToNode::NoEscape) && !Verbose) {
3512 continue;
3513 }
3514 Node* n = ptn->ideal_node();
3515 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3516 n->as_CallStaticJava()->is_boxing_method())) {
3517 if (first) {
3518 tty->cr();
3519 tty->print("======== Connection graph for ");
3520 _compile->method()->print_short_name();
3521 tty->cr();
3522 first = false;
3523 }
3524 ptn->dump();
3525 // Print all locals and fields which reference this allocation
3526 for (UseIterator j(ptn); j.has_next(); j.next()) {
3527 PointsToNode* use = j.get();
3528 if (use->is_LocalVar()) {
3529 use->dump(Verbose);
3530 } else if (Verbose) {
3531 use->dump();
3532 }
3533 }
3534 tty->cr();
3535 }
3536 }
3537 }
3538 #endif