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, "sha1_implCompress") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1002 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1003 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1004 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1005 ))) {
1006 call->dump();
1007 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1008 }
1009 #endif
1010 // Always process arraycopy's destination object since
1011 // we need to add all possible edges to references in
1012 // source object.
1013 if (arg_esc >= PointsToNode::ArgEscape &&
1014 !arg_is_arraycopy_dest) {
1015 continue;
1016 }
1017 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1018 if (call->is_ArrayCopy()) {
1019 ArrayCopyNode* ac = call->as_ArrayCopy();
1020 if (ac->is_clonebasic() ||
1021 ac->is_arraycopy_validated() ||
1022 ac->is_copyof_validated() ||
1023 ac->is_copyofrange_validated()) {
1024 es = PointsToNode::NoEscape;
1025 }
1026 }
1027 set_escape_state(arg_ptn, es);
1028 if (arg_is_arraycopy_dest) {
1029 Node* src = call->in(TypeFunc::Parms);
1030 if (src->is_AddP()) {
1031 src = get_addp_base(src);
1032 }
1033 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1034 assert(src_ptn != NULL, "should be registered");
1035 if (arg_ptn != src_ptn) {
1036 // Special arraycopy edge:
1037 // A destination object's field can't have the source object
1038 // as base since objects escape states are not related.
1039 // Only escape state of destination object's fields affects
1040 // escape state of fields in source object.
1041 add_arraycopy(call, es, src_ptn, arg_ptn);
1042 }
1043 }
1044 }
1045 }
1046 break;
1047 }
1048 case Op_CallStaticJava: {
1049 // For a static call, we know exactly what method is being called.
1050 // Use bytecode estimator to record the call's escape affects
1051 #ifdef ASSERT
1052 const char* name = call->as_CallStaticJava()->_name;
1053 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1054 #endif
1055 ciMethod* meth = call->as_CallJava()->method();
1056 if ((meth != NULL) && meth->is_boxing_method()) {
1057 break; // Boxing methods do not modify any oops.
1058 }
1059 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1060 // fall-through if not a Java method or no analyzer information
1061 if (call_analyzer != NULL) {
1062 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1063 const TypeTuple* d = call->tf()->domain();
1064 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1065 const Type* at = d->field_at(i);
1066 int k = i - TypeFunc::Parms;
1067 Node* arg = call->in(i);
1068 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1069 if (at->isa_ptr() != NULL &&
1070 call_analyzer->is_arg_returned(k)) {
1071 // The call returns arguments.
1072 if (call_ptn != NULL) { // Is call's result used?
1073 assert(call_ptn->is_LocalVar(), "node should be registered");
1074 assert(arg_ptn != NULL, "node should be registered");
1075 add_edge(call_ptn, arg_ptn);
1076 }
1077 }
1078 if (at->isa_oopptr() != NULL &&
1079 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1080 if (!call_analyzer->is_arg_stack(k)) {
1081 // The argument global escapes
1082 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1083 } else {
1084 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1085 if (!call_analyzer->is_arg_local(k)) {
1086 // The argument itself doesn't escape, but any fields might
1087 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1088 }
1089 }
1090 }
1091 }
1092 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1093 // The call returns arguments.
1094 assert(call_ptn->edge_count() > 0, "sanity");
1095 if (!call_analyzer->is_return_local()) {
1096 // Returns also unknown object.
1097 add_edge(call_ptn, phantom_obj);
1098 }
1099 }
1100 break;
1101 }
1102 }
1103 default: {
1104 // Fall-through here if not a Java method or no analyzer information
1105 // or some other type of call, assume the worst case: all arguments
1106 // globally escape.
1107 const TypeTuple* d = call->tf()->domain();
1108 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1109 const Type* at = d->field_at(i);
1110 if (at->isa_oopptr() != NULL) {
1111 Node* arg = call->in(i);
1112 if (arg->is_AddP()) {
1113 arg = get_addp_base(arg);
1114 }
1115 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1116 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1117 }
1118 }
1119 }
1120 }
1121 }
1122
1123
1124 // Finish Graph construction.
1125 bool ConnectionGraph::complete_connection_graph(
1126 GrowableArray<PointsToNode*>& ptnodes_worklist,
1127 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1128 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1129 GrowableArray<FieldNode*>& oop_fields_worklist) {
1130 // Normally only 1-3 passes needed to build Connection Graph depending
1131 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1132 // Set limit to 20 to catch situation when something did go wrong and
1133 // bailout Escape Analysis.
1134 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1135 #define CG_BUILD_ITER_LIMIT 20
1136
1137 // Propagate GlobalEscape and ArgEscape escape states and check that
1138 // we still have non-escaping objects. The method pushs on _worklist
1139 // Field nodes which reference phantom_object.
1140 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1141 return false; // Nothing to do.
1142 }
1143 // Now propagate references to all JavaObject nodes.
1144 int java_objects_length = java_objects_worklist.length();
1145 elapsedTimer time;
1146 bool timeout = false;
1147 int new_edges = 1;
1148 int iterations = 0;
1149 do {
1150 while ((new_edges > 0) &&
1151 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1152 double start_time = time.seconds();
1153 time.start();
1154 new_edges = 0;
1155 // Propagate references to phantom_object for nodes pushed on _worklist
1156 // by find_non_escaped_objects() and find_field_value().
1157 new_edges += add_java_object_edges(phantom_obj, false);
1158 for (int next = 0; next < java_objects_length; ++next) {
1159 JavaObjectNode* ptn = java_objects_worklist.at(next);
1160 new_edges += add_java_object_edges(ptn, true);
1161
1162 #define SAMPLE_SIZE 4
1163 if ((next % SAMPLE_SIZE) == 0) {
1164 // Each 4 iterations calculate how much time it will take
1165 // to complete graph construction.
1166 time.stop();
1167 // Poll for requests from shutdown mechanism to quiesce compiler
1168 // because Connection graph construction may take long time.
1169 CompileBroker::maybe_block();
1170 double stop_time = time.seconds();
1171 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1172 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1173 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1174 timeout = true;
1175 break; // Timeout
1176 }
1177 start_time = stop_time;
1178 time.start();
1179 }
1180 #undef SAMPLE_SIZE
1181
1182 }
1183 if (timeout) break;
1184 if (new_edges > 0) {
1185 // Update escape states on each iteration if graph was updated.
1186 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1187 return false; // Nothing to do.
1188 }
1189 }
1190 time.stop();
1191 if (time.seconds() >= EscapeAnalysisTimeout) {
1192 timeout = true;
1193 break;
1194 }
1195 }
1196 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1197 time.start();
1198 // Find fields which have unknown value.
1199 int fields_length = oop_fields_worklist.length();
1200 for (int next = 0; next < fields_length; next++) {
1201 FieldNode* field = oop_fields_worklist.at(next);
1202 if (field->edge_count() == 0) {
1203 new_edges += find_field_value(field);
1204 // This code may added new edges to phantom_object.
1205 // Need an other cycle to propagate references to phantom_object.
1206 }
1207 }
1208 time.stop();
1209 if (time.seconds() >= EscapeAnalysisTimeout) {
1210 timeout = true;
1211 break;
1212 }
1213 } else {
1214 new_edges = 0; // Bailout
1215 }
1216 } while (new_edges > 0);
1217
1218 // Bailout if passed limits.
1219 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1220 Compile* C = _compile;
1221 if (C->log() != NULL) {
1222 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1223 C->log()->text("%s", timeout ? "time" : "iterations");
1224 C->log()->end_elem(" limit'");
1225 }
1226 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1227 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1228 // Possible infinite build_connection_graph loop,
1229 // bailout (no changes to ideal graph were made).
1230 return false;
1231 }
1232 #ifdef ASSERT
1233 if (Verbose && PrintEscapeAnalysis) {
1234 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1235 iterations, nodes_size(), ptnodes_worklist.length());
1236 }
1237 #endif
1238
1239 #undef CG_BUILD_ITER_LIMIT
1240
1241 // Find fields initialized by NULL for non-escaping Allocations.
1242 int non_escaped_length = non_escaped_worklist.length();
1243 for (int next = 0; next < non_escaped_length; next++) {
1244 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1245 PointsToNode::EscapeState es = ptn->escape_state();
1246 assert(es <= PointsToNode::ArgEscape, "sanity");
1247 if (es == PointsToNode::NoEscape) {
1248 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1249 // Adding references to NULL object does not change escape states
1250 // since it does not escape. Also no fields are added to NULL object.
1251 add_java_object_edges(null_obj, false);
1252 }
1253 }
1254 Node* n = ptn->ideal_node();
1255 if (n->is_Allocate()) {
1256 // The object allocated by this Allocate node will never be
1257 // seen by an other thread. Mark it so that when it is
1258 // expanded no MemBarStoreStore is added.
1259 InitializeNode* ini = n->as_Allocate()->initialization();
1260 if (ini != NULL)
1261 ini->set_does_not_escape();
1262 }
1263 }
1264 return true; // Finished graph construction.
1265 }
1266
1267 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1268 // and check that we still have non-escaping java objects.
1269 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1270 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1271 GrowableArray<PointsToNode*> escape_worklist;
1272 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1273 int ptnodes_length = ptnodes_worklist.length();
1274 for (int next = 0; next < ptnodes_length; ++next) {
1275 PointsToNode* ptn = ptnodes_worklist.at(next);
1276 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1277 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1278 escape_worklist.push(ptn);
1279 }
1280 }
1281 // Set escape states to referenced nodes (edges list).
1282 while (escape_worklist.length() > 0) {
1283 PointsToNode* ptn = escape_worklist.pop();
1284 PointsToNode::EscapeState es = ptn->escape_state();
1285 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1286 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1287 es >= PointsToNode::ArgEscape) {
1288 // GlobalEscape or ArgEscape state of field means it has unknown value.
1289 if (add_edge(ptn, phantom_obj)) {
1290 // New edge was added
1291 add_field_uses_to_worklist(ptn->as_Field());
1292 }
1293 }
1294 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1295 PointsToNode* e = i.get();
1296 if (e->is_Arraycopy()) {
1297 assert(ptn->arraycopy_dst(), "sanity");
1298 // Propagate only fields escape state through arraycopy edge.
1299 if (e->fields_escape_state() < field_es) {
1300 set_fields_escape_state(e, field_es);
1301 escape_worklist.push(e);
1302 }
1303 } else if (es >= field_es) {
1304 // fields_escape_state is also set to 'es' if it is less than 'es'.
1305 if (e->escape_state() < es) {
1306 set_escape_state(e, es);
1307 escape_worklist.push(e);
1308 }
1309 } else {
1310 // Propagate field escape state.
1311 bool es_changed = false;
1312 if (e->fields_escape_state() < field_es) {
1313 set_fields_escape_state(e, field_es);
1314 es_changed = true;
1315 }
1316 if ((e->escape_state() < field_es) &&
1317 e->is_Field() && ptn->is_JavaObject() &&
1318 e->as_Field()->is_oop()) {
1319 // Change escape state of referenced fields.
1320 set_escape_state(e, field_es);
1321 es_changed = true;
1322 } else if (e->escape_state() < es) {
1323 set_escape_state(e, es);
1324 es_changed = true;
1325 }
1326 if (es_changed) {
1327 escape_worklist.push(e);
1328 }
1329 }
1330 }
1331 }
1332 // Remove escaped objects from non_escaped list.
1333 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1334 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1335 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1336 non_escaped_worklist.delete_at(next);
1337 }
1338 if (ptn->escape_state() == PointsToNode::NoEscape) {
1339 // Find fields in non-escaped allocations which have unknown value.
1340 find_init_values(ptn, phantom_obj, NULL);
1341 }
1342 }
1343 return (non_escaped_worklist.length() > 0);
1344 }
1345
1346 // Add all references to JavaObject node by walking over all uses.
1347 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1348 int new_edges = 0;
1349 if (populate_worklist) {
1350 // Populate _worklist by uses of jobj's uses.
1351 for (UseIterator i(jobj); i.has_next(); i.next()) {
1352 PointsToNode* use = i.get();
1353 if (use->is_Arraycopy())
1354 continue;
1355 add_uses_to_worklist(use);
1356 if (use->is_Field() && use->as_Field()->is_oop()) {
1357 // Put on worklist all field's uses (loads) and
1358 // related field nodes (same base and offset).
1359 add_field_uses_to_worklist(use->as_Field());
1360 }
1361 }
1362 }
1363 for (int l = 0; l < _worklist.length(); l++) {
1364 PointsToNode* use = _worklist.at(l);
1365 if (PointsToNode::is_base_use(use)) {
1366 // Add reference from jobj to field and from field to jobj (field's base).
1367 use = PointsToNode::get_use_node(use)->as_Field();
1368 if (add_base(use->as_Field(), jobj)) {
1369 new_edges++;
1370 }
1371 continue;
1372 }
1373 assert(!use->is_JavaObject(), "sanity");
1374 if (use->is_Arraycopy()) {
1375 if (jobj == null_obj) // NULL object does not have field edges
1376 continue;
1377 // Added edge from Arraycopy node to arraycopy's source java object
1378 if (add_edge(use, jobj)) {
1379 jobj->set_arraycopy_src();
1380 new_edges++;
1381 }
1382 // and stop here.
1383 continue;
1384 }
1385 if (!add_edge(use, jobj))
1386 continue; // No new edge added, there was such edge already.
1387 new_edges++;
1388 if (use->is_LocalVar()) {
1389 add_uses_to_worklist(use);
1390 if (use->arraycopy_dst()) {
1391 for (EdgeIterator i(use); i.has_next(); i.next()) {
1392 PointsToNode* e = i.get();
1393 if (e->is_Arraycopy()) {
1394 if (jobj == null_obj) // NULL object does not have field edges
1395 continue;
1396 // Add edge from arraycopy's destination java object to Arraycopy node.
1397 if (add_edge(jobj, e)) {
1398 new_edges++;
1399 jobj->set_arraycopy_dst();
1400 }
1401 }
1402 }
1403 }
1404 } else {
1405 // Added new edge to stored in field values.
1406 // Put on worklist all field's uses (loads) and
1407 // related field nodes (same base and offset).
1408 add_field_uses_to_worklist(use->as_Field());
1409 }
1410 }
1411 _worklist.clear();
1412 _in_worklist.Reset();
1413 return new_edges;
1414 }
1415
1416 // Put on worklist all related field nodes.
1417 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1418 assert(field->is_oop(), "sanity");
1419 int offset = field->offset();
1420 add_uses_to_worklist(field);
1421 // Loop over all bases of this field and push on worklist Field nodes
1422 // with the same offset and base (since they may reference the same field).
1423 for (BaseIterator i(field); i.has_next(); i.next()) {
1424 PointsToNode* base = i.get();
1425 add_fields_to_worklist(field, base);
1426 // Check if the base was source object of arraycopy and go over arraycopy's
1427 // destination objects since values stored to a field of source object are
1428 // accessable by uses (loads) of fields of destination objects.
1429 if (base->arraycopy_src()) {
1430 for (UseIterator j(base); j.has_next(); j.next()) {
1431 PointsToNode* arycp = j.get();
1432 if (arycp->is_Arraycopy()) {
1433 for (UseIterator k(arycp); k.has_next(); k.next()) {
1434 PointsToNode* abase = k.get();
1435 if (abase->arraycopy_dst() && abase != base) {
1436 // Look for the same arraycopy reference.
1437 add_fields_to_worklist(field, abase);
1438 }
1439 }
1440 }
1441 }
1442 }
1443 }
1444 }
1445
1446 // Put on worklist all related field nodes.
1447 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1448 int offset = field->offset();
1449 if (base->is_LocalVar()) {
1450 for (UseIterator j(base); j.has_next(); j.next()) {
1451 PointsToNode* f = j.get();
1452 if (PointsToNode::is_base_use(f)) { // Field
1453 f = PointsToNode::get_use_node(f);
1454 if (f == field || !f->as_Field()->is_oop())
1455 continue;
1456 int offs = f->as_Field()->offset();
1457 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1458 add_to_worklist(f);
1459 }
1460 }
1461 }
1462 } else {
1463 assert(base->is_JavaObject(), "sanity");
1464 if (// Skip phantom_object since it is only used to indicate that
1465 // this field's content globally escapes.
1466 (base != phantom_obj) &&
1467 // NULL object node does not have fields.
1468 (base != null_obj)) {
1469 for (EdgeIterator i(base); i.has_next(); i.next()) {
1470 PointsToNode* f = i.get();
1471 // Skip arraycopy edge since store to destination object field
1472 // does not update value in source object field.
1473 if (f->is_Arraycopy()) {
1474 assert(base->arraycopy_dst(), "sanity");
1475 continue;
1476 }
1477 if (f == field || !f->as_Field()->is_oop())
1478 continue;
1479 int offs = f->as_Field()->offset();
1480 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1481 add_to_worklist(f);
1482 }
1483 }
1484 }
1485 }
1486 }
1487
1488 // Find fields which have unknown value.
1489 int ConnectionGraph::find_field_value(FieldNode* field) {
1490 // Escaped fields should have init value already.
1491 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1492 int new_edges = 0;
1493 for (BaseIterator i(field); i.has_next(); i.next()) {
1494 PointsToNode* base = i.get();
1495 if (base->is_JavaObject()) {
1496 // Skip Allocate's fields which will be processed later.
1497 if (base->ideal_node()->is_Allocate())
1498 return 0;
1499 assert(base == null_obj, "only NULL ptr base expected here");
1500 }
1501 }
1502 if (add_edge(field, phantom_obj)) {
1503 // New edge was added
1504 new_edges++;
1505 add_field_uses_to_worklist(field);
1506 }
1507 return new_edges;
1508 }
1509
1510 // Find fields initializing values for allocations.
1511 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1512 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1513 int new_edges = 0;
1514 Node* alloc = pta->ideal_node();
1515 if (init_val == phantom_obj) {
1516 // Do nothing for Allocate nodes since its fields values are
1517 // "known" unless they are initialized by arraycopy/clone.
1518 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1519 return 0;
1520 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1521 #ifdef ASSERT
1522 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1523 const char* name = alloc->as_CallStaticJava()->_name;
1524 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1525 }
1526 #endif
1527 // Non-escaped allocation returned from Java or runtime call have
1528 // unknown values in fields.
1529 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1530 PointsToNode* field = i.get();
1531 if (field->is_Field() && field->as_Field()->is_oop()) {
1532 if (add_edge(field, phantom_obj)) {
1533 // New edge was added
1534 new_edges++;
1535 add_field_uses_to_worklist(field->as_Field());
1536 }
1537 }
1538 }
1539 return new_edges;
1540 }
1541 assert(init_val == null_obj, "sanity");
1542 // Do nothing for Call nodes since its fields values are unknown.
1543 if (!alloc->is_Allocate())
1544 return 0;
1545
1546 InitializeNode* ini = alloc->as_Allocate()->initialization();
1547 bool visited_bottom_offset = false;
1548 GrowableArray<int> offsets_worklist;
1549
1550 // Check if an oop field's initializing value is recorded and add
1551 // a corresponding NULL if field's value if it is not recorded.
1552 // Connection Graph does not record a default initialization by NULL
1553 // captured by Initialize node.
1554 //
1555 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1556 PointsToNode* field = i.get(); // Field (AddP)
1557 if (!field->is_Field() || !field->as_Field()->is_oop())
1558 continue; // Not oop field
1559 int offset = field->as_Field()->offset();
1560 if (offset == Type::OffsetBot) {
1561 if (!visited_bottom_offset) {
1562 // OffsetBot is used to reference array's element,
1563 // always add reference to NULL to all Field nodes since we don't
1564 // known which element is referenced.
1565 if (add_edge(field, null_obj)) {
1566 // New edge was added
1567 new_edges++;
1568 add_field_uses_to_worklist(field->as_Field());
1569 visited_bottom_offset = true;
1570 }
1571 }
1572 } else {
1573 // Check only oop fields.
1574 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1575 if (adr_type->isa_rawptr()) {
1576 #ifdef ASSERT
1577 // Raw pointers are used for initializing stores so skip it
1578 // since it should be recorded already
1579 Node* base = get_addp_base(field->ideal_node());
1580 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1581 (base->in(0) == alloc),"unexpected pointer type");
1582 #endif
1583 continue;
1584 }
1585 if (!offsets_worklist.contains(offset)) {
1586 offsets_worklist.append(offset);
1587 Node* value = NULL;
1588 if (ini != NULL) {
1589 // StoreP::memory_type() == T_ADDRESS
1590 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1591 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1592 // Make sure initializing store has the same type as this AddP.
1593 // This AddP may reference non existing field because it is on a
1594 // dead branch of bimorphic call which is not eliminated yet.
1595 if (store != NULL && store->is_Store() &&
1596 store->as_Store()->memory_type() == ft) {
1597 value = store->in(MemNode::ValueIn);
1598 #ifdef ASSERT
1599 if (VerifyConnectionGraph) {
1600 // Verify that AddP already points to all objects the value points to.
1601 PointsToNode* val = ptnode_adr(value->_idx);
1602 assert((val != NULL), "should be processed already");
1603 PointsToNode* missed_obj = NULL;
1604 if (val->is_JavaObject()) {
1605 if (!field->points_to(val->as_JavaObject())) {
1606 missed_obj = val;
1607 }
1608 } else {
1609 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1610 tty->print_cr("----------init store has invalid value -----");
1611 store->dump();
1612 val->dump();
1613 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1614 }
1615 for (EdgeIterator j(val); j.has_next(); j.next()) {
1616 PointsToNode* obj = j.get();
1617 if (obj->is_JavaObject()) {
1618 if (!field->points_to(obj->as_JavaObject())) {
1619 missed_obj = obj;
1620 break;
1621 }
1622 }
1623 }
1624 }
1625 if (missed_obj != NULL) {
1626 tty->print_cr("----------field---------------------------------");
1627 field->dump();
1628 tty->print_cr("----------missed referernce to object-----------");
1629 missed_obj->dump();
1630 tty->print_cr("----------object referernced by init store -----");
1631 store->dump();
1632 val->dump();
1633 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1634 }
1635 }
1636 #endif
1637 } else {
1638 // There could be initializing stores which follow allocation.
1639 // For example, a volatile field store is not collected
1640 // by Initialize node.
1641 //
1642 // Need to check for dependent loads to separate such stores from
1643 // stores which follow loads. For now, add initial value NULL so
1644 // that compare pointers optimization works correctly.
1645 }
1646 }
1647 if (value == NULL) {
1648 // A field's initializing value was not recorded. Add NULL.
1649 if (add_edge(field, null_obj)) {
1650 // New edge was added
1651 new_edges++;
1652 add_field_uses_to_worklist(field->as_Field());
1653 }
1654 }
1655 }
1656 }
1657 }
1658 return new_edges;
1659 }
1660
1661 // Adjust scalar_replaceable state after Connection Graph is built.
1662 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1663 // Search for non-escaping objects which are not scalar replaceable
1664 // and mark them to propagate the state to referenced objects.
1665
1666 // 1. An object is not scalar replaceable if the field into which it is
1667 // stored has unknown offset (stored into unknown element of an array).
1668 //
1669 for (UseIterator i(jobj); i.has_next(); i.next()) {
1670 PointsToNode* use = i.get();
1671 if (use->is_Arraycopy()) {
1672 continue;
1673 }
1674 if (use->is_Field()) {
1675 FieldNode* field = use->as_Field();
1676 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1677 if (field->offset() == Type::OffsetBot) {
1678 jobj->set_scalar_replaceable(false);
1679 return;
1680 }
1681 // 2. An object is not scalar replaceable if the field into which it is
1682 // stored has multiple bases one of which is null.
1683 if (field->base_count() > 1) {
1684 for (BaseIterator i(field); i.has_next(); i.next()) {
1685 PointsToNode* base = i.get();
1686 if (base == null_obj) {
1687 jobj->set_scalar_replaceable(false);
1688 return;
1689 }
1690 }
1691 }
1692 }
1693 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1694 // 3. An object is not scalar replaceable if it is merged with other objects.
1695 for (EdgeIterator j(use); j.has_next(); j.next()) {
1696 PointsToNode* ptn = j.get();
1697 if (ptn->is_JavaObject() && ptn != jobj) {
1698 // Mark all objects.
1699 jobj->set_scalar_replaceable(false);
1700 ptn->set_scalar_replaceable(false);
1701 }
1702 }
1703 if (!jobj->scalar_replaceable()) {
1704 return;
1705 }
1706 }
1707
1708 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1709 if (j.get()->is_Arraycopy()) {
1710 continue;
1711 }
1712
1713 // Non-escaping object node should point only to field nodes.
1714 FieldNode* field = j.get()->as_Field();
1715 int offset = field->as_Field()->offset();
1716
1717 // 4. An object is not scalar replaceable if it has a field with unknown
1718 // offset (array's element is accessed in loop).
1719 if (offset == Type::OffsetBot) {
1720 jobj->set_scalar_replaceable(false);
1721 return;
1722 }
1723 // 5. Currently an object is not scalar replaceable if a LoadStore node
1724 // access its field since the field value is unknown after it.
1725 //
1726 Node* n = field->ideal_node();
1727 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1728 if (n->fast_out(i)->is_LoadStore()) {
1729 jobj->set_scalar_replaceable(false);
1730 return;
1731 }
1732 }
1733
1734 // 6. Or the address may point to more then one object. This may produce
1735 // the false positive result (set not scalar replaceable)
1736 // since the flow-insensitive escape analysis can't separate
1737 // the case when stores overwrite the field's value from the case
1738 // when stores happened on different control branches.
1739 //
1740 // Note: it will disable scalar replacement in some cases:
1741 //
1742 // Point p[] = new Point[1];
1743 // p[0] = new Point(); // Will be not scalar replaced
1744 //
1745 // but it will save us from incorrect optimizations in next cases:
1746 //
1747 // Point p[] = new Point[1];
1748 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1749 //
1750 if (field->base_count() > 1) {
1751 for (BaseIterator i(field); i.has_next(); i.next()) {
1752 PointsToNode* base = i.get();
1753 // Don't take into account LocalVar nodes which
1754 // may point to only one object which should be also
1755 // this field's base by now.
1756 if (base->is_JavaObject() && base != jobj) {
1757 // Mark all bases.
1758 jobj->set_scalar_replaceable(false);
1759 base->set_scalar_replaceable(false);
1760 }
1761 }
1762 }
1763 }
1764 }
1765
1766 #ifdef ASSERT
1767 void ConnectionGraph::verify_connection_graph(
1768 GrowableArray<PointsToNode*>& ptnodes_worklist,
1769 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1770 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1771 GrowableArray<Node*>& addp_worklist) {
1772 // Verify that graph is complete - no new edges could be added.
1773 int java_objects_length = java_objects_worklist.length();
1774 int non_escaped_length = non_escaped_worklist.length();
1775 int new_edges = 0;
1776 for (int next = 0; next < java_objects_length; ++next) {
1777 JavaObjectNode* ptn = java_objects_worklist.at(next);
1778 new_edges += add_java_object_edges(ptn, true);
1779 }
1780 assert(new_edges == 0, "graph was not complete");
1781 // Verify that escape state is final.
1782 int length = non_escaped_worklist.length();
1783 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1784 assert((non_escaped_length == non_escaped_worklist.length()) &&
1785 (non_escaped_length == length) &&
1786 (_worklist.length() == 0), "escape state was not final");
1787
1788 // Verify fields information.
1789 int addp_length = addp_worklist.length();
1790 for (int next = 0; next < addp_length; ++next ) {
1791 Node* n = addp_worklist.at(next);
1792 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1793 if (field->is_oop()) {
1794 // Verify that field has all bases
1795 Node* base = get_addp_base(n);
1796 PointsToNode* ptn = ptnode_adr(base->_idx);
1797 if (ptn->is_JavaObject()) {
1798 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1799 } else {
1800 assert(ptn->is_LocalVar(), "sanity");
1801 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1802 PointsToNode* e = i.get();
1803 if (e->is_JavaObject()) {
1804 assert(field->has_base(e->as_JavaObject()), "sanity");
1805 }
1806 }
1807 }
1808 // Verify that all fields have initializing values.
1809 if (field->edge_count() == 0) {
1810 tty->print_cr("----------field does not have references----------");
1811 field->dump();
1812 for (BaseIterator i(field); i.has_next(); i.next()) {
1813 PointsToNode* base = i.get();
1814 tty->print_cr("----------field has next base---------------------");
1815 base->dump();
1816 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1817 tty->print_cr("----------base has fields-------------------------");
1818 for (EdgeIterator j(base); j.has_next(); j.next()) {
1819 j.get()->dump();
1820 }
1821 tty->print_cr("----------base has references---------------------");
1822 for (UseIterator j(base); j.has_next(); j.next()) {
1823 j.get()->dump();
1824 }
1825 }
1826 }
1827 for (UseIterator i(field); i.has_next(); i.next()) {
1828 i.get()->dump();
1829 }
1830 assert(field->edge_count() > 0, "sanity");
1831 }
1832 }
1833 }
1834 }
1835 #endif
1836
1837 // Optimize ideal graph.
1838 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1839 GrowableArray<Node*>& storestore_worklist) {
1840 Compile* C = _compile;
1841 PhaseIterGVN* igvn = _igvn;
1842 if (EliminateLocks) {
1843 // Mark locks before changing ideal graph.
1844 int cnt = C->macro_count();
1845 for( int i=0; i < cnt; i++ ) {
1846 Node *n = C->macro_node(i);
1847 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1848 AbstractLockNode* alock = n->as_AbstractLock();
1849 if (!alock->is_non_esc_obj()) {
1850 if (not_global_escape(alock->obj_node())) {
1851 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1852 // The lock could be marked eliminated by lock coarsening
1853 // code during first IGVN before EA. Replace coarsened flag
1854 // to eliminate all associated locks/unlocks.
1855 #ifdef ASSERT
1856 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1857 #endif
1858 alock->set_non_esc_obj();
1859 }
1860 }
1861 }
1862 }
1863 }
1864
1865 if (OptimizePtrCompare) {
1866 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1867 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1868 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1869 // Optimize objects compare.
1870 while (ptr_cmp_worklist.length() != 0) {
1871 Node *n = ptr_cmp_worklist.pop();
1872 Node *res = optimize_ptr_compare(n);
1873 if (res != NULL) {
1874 #ifndef PRODUCT
1875 if (PrintOptimizePtrCompare) {
1876 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"));
1877 if (Verbose) {
1878 n->dump(1);
1879 }
1880 }
1881 #endif
1882 igvn->replace_node(n, res);
1883 }
1884 }
1885 // cleanup
1886 if (_pcmp_neq->outcnt() == 0)
1887 igvn->hash_delete(_pcmp_neq);
1888 if (_pcmp_eq->outcnt() == 0)
1889 igvn->hash_delete(_pcmp_eq);
1890 }
1891
1892 // For MemBarStoreStore nodes added in library_call.cpp, check
1893 // escape status of associated AllocateNode and optimize out
1894 // MemBarStoreStore node if the allocated object never escapes.
1895 while (storestore_worklist.length() != 0) {
1896 Node *n = storestore_worklist.pop();
1897 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1898 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1899 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1900 if (not_global_escape(alloc)) {
1901 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1902 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1903 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1904 igvn->register_new_node_with_optimizer(mb);
1905 igvn->replace_node(storestore, mb);
1906 }
1907 }
1908 }
1909
1910 // Optimize objects compare.
1911 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1912 assert(OptimizePtrCompare, "sanity");
1913 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1914 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1915 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1916 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1917 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1918 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1919
1920 // Check simple cases first.
1921 if (jobj1 != NULL) {
1922 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1923 if (jobj1 == jobj2) {
1924 // Comparing the same not escaping object.
1925 return _pcmp_eq;
1926 }
1927 Node* obj = jobj1->ideal_node();
1928 // Comparing not escaping allocation.
1929 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1930 !ptn2->points_to(jobj1)) {
1931 return _pcmp_neq; // This includes nullness check.
1932 }
1933 }
1934 }
1935 if (jobj2 != NULL) {
1936 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1937 Node* obj = jobj2->ideal_node();
1938 // Comparing not escaping allocation.
1939 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1940 !ptn1->points_to(jobj2)) {
1941 return _pcmp_neq; // This includes nullness check.
1942 }
1943 }
1944 }
1945 if (jobj1 != NULL && jobj1 != phantom_obj &&
1946 jobj2 != NULL && jobj2 != phantom_obj &&
1947 jobj1->ideal_node()->is_Con() &&
1948 jobj2->ideal_node()->is_Con()) {
1949 // Klass or String constants compare. Need to be careful with
1950 // compressed pointers - compare types of ConN and ConP instead of nodes.
1951 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1952 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1953 if (t1->make_ptr() == t2->make_ptr()) {
1954 return _pcmp_eq;
1955 } else {
1956 return _pcmp_neq;
1957 }
1958 }
1959 if (ptn1->meet(ptn2)) {
1960 return NULL; // Sets are not disjoint
1961 }
1962
1963 // Sets are disjoint.
1964 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1965 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1966 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1967 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1968 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
1969 (set2_has_unknown_ptr && set1_has_null_ptr)) {
1970 // Check nullness of unknown object.
1971 return NULL;
1972 }
1973
1974 // Disjointness by itself is not sufficient since
1975 // alias analysis is not complete for escaped objects.
1976 // Disjoint sets are definitely unrelated only when
1977 // at least one set has only not escaping allocations.
1978 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1979 if (ptn1->non_escaping_allocation()) {
1980 return _pcmp_neq;
1981 }
1982 }
1983 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1984 if (ptn2->non_escaping_allocation()) {
1985 return _pcmp_neq;
1986 }
1987 }
1988 return NULL;
1989 }
1990
1991 // Connection Graph constuction functions.
1992
1993 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1994 PointsToNode* ptadr = _nodes.at(n->_idx);
1995 if (ptadr != NULL) {
1996 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1997 return;
1998 }
1999 Compile* C = _compile;
2000 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2001 _nodes.at_put(n->_idx, ptadr);
2002 }
2003
2004 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2005 PointsToNode* ptadr = _nodes.at(n->_idx);
2006 if (ptadr != NULL) {
2007 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2008 return;
2009 }
2010 Compile* C = _compile;
2011 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2012 _nodes.at_put(n->_idx, ptadr);
2013 }
2014
2015 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2016 PointsToNode* ptadr = _nodes.at(n->_idx);
2017 if (ptadr != NULL) {
2018 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2019 return;
2020 }
2021 bool unsafe = false;
2022 bool is_oop = is_oop_field(n, offset, &unsafe);
2023 if (unsafe) {
2024 es = PointsToNode::GlobalEscape;
2025 }
2026 Compile* C = _compile;
2027 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2028 _nodes.at_put(n->_idx, field);
2029 }
2030
2031 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2032 PointsToNode* src, PointsToNode* dst) {
2033 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2034 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2035 PointsToNode* ptadr = _nodes.at(n->_idx);
2036 if (ptadr != NULL) {
2037 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2038 return;
2039 }
2040 Compile* C = _compile;
2041 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2042 _nodes.at_put(n->_idx, ptadr);
2043 // Add edge from arraycopy node to source object.
2044 (void)add_edge(ptadr, src);
2045 src->set_arraycopy_src();
2046 // Add edge from destination object to arraycopy node.
2047 (void)add_edge(dst, ptadr);
2048 dst->set_arraycopy_dst();
2049 }
2050
2051 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2052 const Type* adr_type = n->as_AddP()->bottom_type();
2053 BasicType bt = T_INT;
2054 if (offset == Type::OffsetBot) {
2055 // Check only oop fields.
2056 if (!adr_type->isa_aryptr() ||
2057 (adr_type->isa_aryptr()->klass() == NULL) ||
2058 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2059 // OffsetBot is used to reference array's element. Ignore first AddP.
2060 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2061 bt = T_OBJECT;
2062 }
2063 }
2064 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2065 if (adr_type->isa_instptr()) {
2066 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2067 if (field != NULL) {
2068 bt = field->layout_type();
2069 } else {
2070 // Check for unsafe oop field access
2071 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2072 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2073 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2074 bt = T_OBJECT;
2075 (*unsafe) = true;
2076 }
2077 }
2078 } else if (adr_type->isa_aryptr()) {
2079 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2080 // Ignore array length load.
2081 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2082 // Ignore first AddP.
2083 } else {
2084 const Type* elemtype = adr_type->isa_aryptr()->elem();
2085 bt = elemtype->array_element_basic_type();
2086 }
2087 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2088 // Allocation initialization, ThreadLocal field access, unsafe access
2089 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2090 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2091 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2092 bt = T_OBJECT;
2093 }
2094 }
2095 }
2096 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2097 }
2098
2099 // Returns unique pointed java object or NULL.
2100 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2101 assert(!_collecting, "should not call when contructed graph");
2102 // If the node was created after the escape computation we can't answer.
2103 uint idx = n->_idx;
2104 if (idx >= nodes_size()) {
2105 return NULL;
2106 }
2107 PointsToNode* ptn = ptnode_adr(idx);
2108 if (ptn->is_JavaObject()) {
2109 return ptn->as_JavaObject();
2110 }
2111 assert(ptn->is_LocalVar(), "sanity");
2112 // Check all java objects it points to.
2113 JavaObjectNode* jobj = NULL;
2114 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2115 PointsToNode* e = i.get();
2116 if (e->is_JavaObject()) {
2117 if (jobj == NULL) {
2118 jobj = e->as_JavaObject();
2119 } else if (jobj != e) {
2120 return NULL;
2121 }
2122 }
2123 }
2124 return jobj;
2125 }
2126
2127 // Return true if this node points only to non-escaping allocations.
2128 bool PointsToNode::non_escaping_allocation() {
2129 if (is_JavaObject()) {
2130 Node* n = ideal_node();
2131 if (n->is_Allocate() || n->is_CallStaticJava()) {
2132 return (escape_state() == PointsToNode::NoEscape);
2133 } else {
2134 return false;
2135 }
2136 }
2137 assert(is_LocalVar(), "sanity");
2138 // Check all java objects it points to.
2139 for (EdgeIterator i(this); i.has_next(); i.next()) {
2140 PointsToNode* e = i.get();
2141 if (e->is_JavaObject()) {
2142 Node* n = e->ideal_node();
2143 if ((e->escape_state() != PointsToNode::NoEscape) ||
2144 !(n->is_Allocate() || n->is_CallStaticJava())) {
2145 return false;
2146 }
2147 }
2148 }
2149 return true;
2150 }
2151
2152 // Return true if we know the node does not escape globally.
2153 bool ConnectionGraph::not_global_escape(Node *n) {
2154 assert(!_collecting, "should not call during graph construction");
2155 // If the node was created after the escape computation we can't answer.
2156 uint idx = n->_idx;
2157 if (idx >= nodes_size()) {
2158 return false;
2159 }
2160 PointsToNode* ptn = ptnode_adr(idx);
2161 PointsToNode::EscapeState es = ptn->escape_state();
2162 // If we have already computed a value, return it.
2163 if (es >= PointsToNode::GlobalEscape)
2164 return false;
2165 if (ptn->is_JavaObject()) {
2166 return true; // (es < PointsToNode::GlobalEscape);
2167 }
2168 assert(ptn->is_LocalVar(), "sanity");
2169 // Check all java objects it points to.
2170 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2171 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2172 return false;
2173 }
2174 return true;
2175 }
2176
2177
2178 // Helper functions
2179
2180 // Return true if this node points to specified node or nodes it points to.
2181 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2182 if (is_JavaObject()) {
2183 return (this == ptn);
2184 }
2185 assert(is_LocalVar() || is_Field(), "sanity");
2186 for (EdgeIterator i(this); i.has_next(); i.next()) {
2187 if (i.get() == ptn)
2188 return true;
2189 }
2190 return false;
2191 }
2192
2193 // Return true if one node points to an other.
2194 bool PointsToNode::meet(PointsToNode* ptn) {
2195 if (this == ptn) {
2196 return true;
2197 } else if (ptn->is_JavaObject()) {
2198 return this->points_to(ptn->as_JavaObject());
2199 } else if (this->is_JavaObject()) {
2200 return ptn->points_to(this->as_JavaObject());
2201 }
2202 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2203 int ptn_count = ptn->edge_count();
2204 for (EdgeIterator i(this); i.has_next(); i.next()) {
2205 PointsToNode* this_e = i.get();
2206 for (int j = 0; j < ptn_count; j++) {
2207 if (this_e == ptn->edge(j))
2208 return true;
2209 }
2210 }
2211 return false;
2212 }
2213
2214 #ifdef ASSERT
2215 // Return true if bases point to this java object.
2216 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2217 for (BaseIterator i(this); i.has_next(); i.next()) {
2218 if (i.get() == jobj)
2219 return true;
2220 }
2221 return false;
2222 }
2223 #endif
2224
2225 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2226 const Type *adr_type = phase->type(adr);
2227 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2228 adr->in(AddPNode::Address)->is_Proj() &&
2229 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2230 // We are computing a raw address for a store captured by an Initialize
2231 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2232 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2233 assert(offs != Type::OffsetBot ||
2234 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2235 "offset must be a constant or it is initialization of array");
2236 return offs;
2237 }
2238 const TypePtr *t_ptr = adr_type->isa_ptr();
2239 assert(t_ptr != NULL, "must be a pointer type");
2240 return t_ptr->offset();
2241 }
2242
2243 Node* ConnectionGraph::get_addp_base(Node *addp) {
2244 assert(addp->is_AddP(), "must be AddP");
2245 //
2246 // AddP cases for Base and Address inputs:
2247 // case #1. Direct object's field reference:
2248 // Allocate
2249 // |
2250 // Proj #5 ( oop result )
2251 // |
2252 // CheckCastPP (cast to instance type)
2253 // | |
2254 // AddP ( base == address )
2255 //
2256 // case #2. Indirect object's field reference:
2257 // Phi
2258 // |
2259 // CastPP (cast to instance type)
2260 // | |
2261 // AddP ( base == address )
2262 //
2263 // case #3. Raw object's field reference for Initialize node:
2264 // Allocate
2265 // |
2266 // Proj #5 ( oop result )
2267 // top |
2268 // \ |
2269 // AddP ( base == top )
2270 //
2271 // case #4. Array's element reference:
2272 // {CheckCastPP | CastPP}
2273 // | | |
2274 // | AddP ( array's element offset )
2275 // | |
2276 // AddP ( array's offset )
2277 //
2278 // case #5. Raw object's field reference for arraycopy stub call:
2279 // The inline_native_clone() case when the arraycopy stub is called
2280 // after the allocation before Initialize and CheckCastPP nodes.
2281 // Allocate
2282 // |
2283 // Proj #5 ( oop result )
2284 // | |
2285 // AddP ( base == address )
2286 //
2287 // case #6. Constant Pool, ThreadLocal, CastX2P or
2288 // Raw object's field reference:
2289 // {ConP, ThreadLocal, CastX2P, raw Load}
2290 // top |
2291 // \ |
2292 // AddP ( base == top )
2293 //
2294 // case #7. Klass's field reference.
2295 // LoadKlass
2296 // | |
2297 // AddP ( base == address )
2298 //
2299 // case #8. narrow Klass's field reference.
2300 // LoadNKlass
2301 // |
2302 // DecodeN
2303 // | |
2304 // AddP ( base == address )
2305 //
2306 // case #9. Mixed unsafe access
2307 // {instance}
2308 // |
2309 // CheckCastPP (raw)
2310 // top |
2311 // \ |
2312 // AddP ( base == top )
2313 //
2314 Node *base = addp->in(AddPNode::Base);
2315 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2316 base = addp->in(AddPNode::Address);
2317 while (base->is_AddP()) {
2318 // Case #6 (unsafe access) may have several chained AddP nodes.
2319 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2320 base = base->in(AddPNode::Address);
2321 }
2322 if (base->Opcode() == Op_CheckCastPP &&
2323 base->bottom_type()->isa_rawptr() &&
2324 _igvn->type(base->in(1))->isa_oopptr()) {
2325 base = base->in(1); // Case #9
2326 } else {
2327 Node* uncast_base = base->uncast();
2328 int opcode = uncast_base->Opcode();
2329 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2330 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2331 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2332 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2333 }
2334 }
2335 return base;
2336 }
2337
2338 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2339 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2340 Node* addp2 = addp->raw_out(0);
2341 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2342 addp2->in(AddPNode::Base) == n &&
2343 addp2->in(AddPNode::Address) == addp) {
2344 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2345 //
2346 // Find array's offset to push it on worklist first and
2347 // as result process an array's element offset first (pushed second)
2348 // to avoid CastPP for the array's offset.
2349 // Otherwise the inserted CastPP (LocalVar) will point to what
2350 // the AddP (Field) points to. Which would be wrong since
2351 // the algorithm expects the CastPP has the same point as
2352 // as AddP's base CheckCastPP (LocalVar).
2353 //
2354 // ArrayAllocation
2355 // |
2356 // CheckCastPP
2357 // |
2358 // memProj (from ArrayAllocation CheckCastPP)
2359 // | ||
2360 // | || Int (element index)
2361 // | || | ConI (log(element size))
2362 // | || | /
2363 // | || LShift
2364 // | || /
2365 // | AddP (array's element offset)
2366 // | |
2367 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2368 // | / /
2369 // AddP (array's offset)
2370 // |
2371 // Load/Store (memory operation on array's element)
2372 //
2373 return addp2;
2374 }
2375 return NULL;
2376 }
2377
2378 //
2379 // Adjust the type and inputs of an AddP which computes the
2380 // address of a field of an instance
2381 //
2382 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2383 PhaseGVN* igvn = _igvn;
2384 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2385 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2386 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2387 if (t == NULL) {
2388 // We are computing a raw address for a store captured by an Initialize
2389 // compute an appropriate address type (cases #3 and #5).
2390 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2391 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2392 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2393 assert(offs != Type::OffsetBot, "offset must be a constant");
2394 t = base_t->add_offset(offs)->is_oopptr();
2395 }
2396 int inst_id = base_t->instance_id();
2397 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2398 "old type must be non-instance or match new type");
2399
2400 // The type 't' could be subclass of 'base_t'.
2401 // As result t->offset() could be large then base_t's size and it will
2402 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2403 // constructor verifies correctness of the offset.
2404 //
2405 // It could happened on subclass's branch (from the type profiling
2406 // inlining) which was not eliminated during parsing since the exactness
2407 // of the allocation type was not propagated to the subclass type check.
2408 //
2409 // Or the type 't' could be not related to 'base_t' at all.
2410 // It could happened when CHA type is different from MDO type on a dead path
2411 // (for example, from instanceof check) which is not collapsed during parsing.
2412 //
2413 // Do nothing for such AddP node and don't process its users since
2414 // this code branch will go away.
2415 //
2416 if (!t->is_known_instance() &&
2417 !base_t->klass()->is_subtype_of(t->klass())) {
2418 return false; // bail out
2419 }
2420 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2421 // Do NOT remove the next line: ensure a new alias index is allocated
2422 // for the instance type. Note: C++ will not remove it since the call
2423 // has side effect.
2424 int alias_idx = _compile->get_alias_index(tinst);
2425 igvn->set_type(addp, tinst);
2426 // record the allocation in the node map
2427 set_map(addp, get_map(base->_idx));
2428 // Set addp's Base and Address to 'base'.
2429 Node *abase = addp->in(AddPNode::Base);
2430 Node *adr = addp->in(AddPNode::Address);
2431 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2432 adr->in(0)->_idx == (uint)inst_id) {
2433 // Skip AddP cases #3 and #5.
2434 } else {
2435 assert(!abase->is_top(), "sanity"); // AddP case #3
2436 if (abase != base) {
2437 igvn->hash_delete(addp);
2438 addp->set_req(AddPNode::Base, base);
2439 if (abase == adr) {
2440 addp->set_req(AddPNode::Address, base);
2441 } else {
2442 // AddP case #4 (adr is array's element offset AddP node)
2443 #ifdef ASSERT
2444 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2445 assert(adr->is_AddP() && atype != NULL &&
2446 atype->instance_id() == inst_id, "array's element offset should be processed first");
2447 #endif
2448 }
2449 igvn->hash_insert(addp);
2450 }
2451 }
2452 // Put on IGVN worklist since at least addp's type was changed above.
2453 record_for_optimizer(addp);
2454 return true;
2455 }
2456
2457 //
2458 // Create a new version of orig_phi if necessary. Returns either the newly
2459 // created phi or an existing phi. Sets create_new to indicate whether a new
2460 // phi was created. Cache the last newly created phi in the node map.
2461 //
2462 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2463 Compile *C = _compile;
2464 PhaseGVN* igvn = _igvn;
2465 new_created = false;
2466 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2467 // nothing to do if orig_phi is bottom memory or matches alias_idx
2468 if (phi_alias_idx == alias_idx) {
2469 return orig_phi;
2470 }
2471 // Have we recently created a Phi for this alias index?
2472 PhiNode *result = get_map_phi(orig_phi->_idx);
2473 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2474 return result;
2475 }
2476 // Previous check may fail when the same wide memory Phi was split into Phis
2477 // for different memory slices. Search all Phis for this region.
2478 if (result != NULL) {
2479 Node* region = orig_phi->in(0);
2480 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2481 Node* phi = region->fast_out(i);
2482 if (phi->is_Phi() &&
2483 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2484 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2485 return phi->as_Phi();
2486 }
2487 }
2488 }
2489 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2490 if (C->do_escape_analysis() == true && !C->failing()) {
2491 // Retry compilation without escape analysis.
2492 // If this is the first failure, the sentinel string will "stick"
2493 // to the Compile object, and the C2Compiler will see it and retry.
2494 C->record_failure(C2Compiler::retry_no_escape_analysis());
2495 }
2496 return NULL;
2497 }
2498 orig_phi_worklist.append_if_missing(orig_phi);
2499 const TypePtr *atype = C->get_adr_type(alias_idx);
2500 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2501 C->copy_node_notes_to(result, orig_phi);
2502 igvn->set_type(result, result->bottom_type());
2503 record_for_optimizer(result);
2504 set_map(orig_phi, result);
2505 new_created = true;
2506 return result;
2507 }
2508
2509 //
2510 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2511 // specified alias index.
2512 //
2513 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2514 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2515 Compile *C = _compile;
2516 PhaseGVN* igvn = _igvn;
2517 bool new_phi_created;
2518 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2519 if (!new_phi_created) {
2520 return result;
2521 }
2522 GrowableArray<PhiNode *> phi_list;
2523 GrowableArray<uint> cur_input;
2524 PhiNode *phi = orig_phi;
2525 uint idx = 1;
2526 bool finished = false;
2527 while(!finished) {
2528 while (idx < phi->req()) {
2529 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2530 if (mem != NULL && mem->is_Phi()) {
2531 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2532 if (new_phi_created) {
2533 // found an phi for which we created a new split, push current one on worklist and begin
2534 // processing new one
2535 phi_list.push(phi);
2536 cur_input.push(idx);
2537 phi = mem->as_Phi();
2538 result = newphi;
2539 idx = 1;
2540 continue;
2541 } else {
2542 mem = newphi;
2543 }
2544 }
2545 if (C->failing()) {
2546 return NULL;
2547 }
2548 result->set_req(idx++, mem);
2549 }
2550 #ifdef ASSERT
2551 // verify that the new Phi has an input for each input of the original
2552 assert( phi->req() == result->req(), "must have same number of inputs.");
2553 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2554 #endif
2555 // Check if all new phi's inputs have specified alias index.
2556 // Otherwise use old phi.
2557 for (uint i = 1; i < phi->req(); i++) {
2558 Node* in = result->in(i);
2559 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2560 }
2561 // we have finished processing a Phi, see if there are any more to do
2562 finished = (phi_list.length() == 0 );
2563 if (!finished) {
2564 phi = phi_list.pop();
2565 idx = cur_input.pop();
2566 PhiNode *prev_result = get_map_phi(phi->_idx);
2567 prev_result->set_req(idx++, result);
2568 result = prev_result;
2569 }
2570 }
2571 return result;
2572 }
2573
2574 //
2575 // The next methods are derived from methods in MemNode.
2576 //
2577 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2578 Node *mem = mmem;
2579 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2580 // means an array I have not precisely typed yet. Do not do any
2581 // alias stuff with it any time soon.
2582 if (toop->base() != Type::AnyPtr &&
2583 !(toop->klass() != NULL &&
2584 toop->klass()->is_java_lang_Object() &&
2585 toop->offset() == Type::OffsetBot)) {
2586 mem = mmem->memory_at(alias_idx);
2587 // Update input if it is progress over what we have now
2588 }
2589 return mem;
2590 }
2591
2592 //
2593 // Move memory users to their memory slices.
2594 //
2595 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2596 Compile* C = _compile;
2597 PhaseGVN* igvn = _igvn;
2598 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2599 assert(tp != NULL, "ptr type");
2600 int alias_idx = C->get_alias_index(tp);
2601 int general_idx = C->get_general_index(alias_idx);
2602
2603 // Move users first
2604 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2605 Node* use = n->fast_out(i);
2606 if (use->is_MergeMem()) {
2607 MergeMemNode* mmem = use->as_MergeMem();
2608 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2609 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2610 continue; // Nothing to do
2611 }
2612 // Replace previous general reference to mem node.
2613 uint orig_uniq = C->unique();
2614 Node* m = find_inst_mem(n, general_idx, orig_phis);
2615 assert(orig_uniq == C->unique(), "no new nodes");
2616 mmem->set_memory_at(general_idx, m);
2617 --imax;
2618 --i;
2619 } else if (use->is_MemBar()) {
2620 assert(!use->is_Initialize(), "initializing stores should not be moved");
2621 if (use->req() > MemBarNode::Precedent &&
2622 use->in(MemBarNode::Precedent) == n) {
2623 // Don't move related membars.
2624 record_for_optimizer(use);
2625 continue;
2626 }
2627 tp = use->as_MemBar()->adr_type()->isa_ptr();
2628 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2629 alias_idx == general_idx) {
2630 continue; // Nothing to do
2631 }
2632 // Move to general memory slice.
2633 uint orig_uniq = C->unique();
2634 Node* m = find_inst_mem(n, general_idx, orig_phis);
2635 assert(orig_uniq == C->unique(), "no new nodes");
2636 igvn->hash_delete(use);
2637 imax -= use->replace_edge(n, m);
2638 igvn->hash_insert(use);
2639 record_for_optimizer(use);
2640 --i;
2641 #ifdef ASSERT
2642 } else if (use->is_Mem()) {
2643 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2644 // Don't move related cardmark.
2645 continue;
2646 }
2647 // Memory nodes should have new memory input.
2648 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2649 assert(tp != NULL, "ptr type");
2650 int idx = C->get_alias_index(tp);
2651 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2652 "Following memory nodes should have new memory input or be on the same memory slice");
2653 } else if (use->is_Phi()) {
2654 // Phi nodes should be split and moved already.
2655 tp = use->as_Phi()->adr_type()->isa_ptr();
2656 assert(tp != NULL, "ptr type");
2657 int idx = C->get_alias_index(tp);
2658 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2659 } else {
2660 use->dump();
2661 assert(false, "should not be here");
2662 #endif
2663 }
2664 }
2665 }
2666
2667 //
2668 // Search memory chain of "mem" to find a MemNode whose address
2669 // is the specified alias index.
2670 //
2671 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2672 if (orig_mem == NULL)
2673 return orig_mem;
2674 Compile* C = _compile;
2675 PhaseGVN* igvn = _igvn;
2676 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2677 bool is_instance = (toop != NULL) && toop->is_known_instance();
2678 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2679 Node *prev = NULL;
2680 Node *result = orig_mem;
2681 while (prev != result) {
2682 prev = result;
2683 if (result == start_mem)
2684 break; // hit one of our sentinels
2685 if (result->is_Mem()) {
2686 const Type *at = igvn->type(result->in(MemNode::Address));
2687 if (at == Type::TOP)
2688 break; // Dead
2689 assert (at->isa_ptr() != NULL, "pointer type required.");
2690 int idx = C->get_alias_index(at->is_ptr());
2691 if (idx == alias_idx)
2692 break; // Found
2693 if (!is_instance && (at->isa_oopptr() == NULL ||
2694 !at->is_oopptr()->is_known_instance())) {
2695 break; // Do not skip store to general memory slice.
2696 }
2697 result = result->in(MemNode::Memory);
2698 }
2699 if (!is_instance)
2700 continue; // don't search further for non-instance types
2701 // skip over a call which does not affect this memory slice
2702 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2703 Node *proj_in = result->in(0);
2704 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2705 break; // hit one of our sentinels
2706 } else if (proj_in->is_Call()) {
2707 // ArrayCopy node processed here as well
2708 CallNode *call = proj_in->as_Call();
2709 if (!call->may_modify(toop, igvn)) {
2710 result = call->in(TypeFunc::Memory);
2711 }
2712 } else if (proj_in->is_Initialize()) {
2713 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2714 // Stop if this is the initialization for the object instance which
2715 // which contains this memory slice, otherwise skip over it.
2716 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2717 result = proj_in->in(TypeFunc::Memory);
2718 }
2719 } else if (proj_in->is_MemBar()) {
2720 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2721 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2722 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2723 // clone
2724 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2725 if (ac->may_modify(toop, igvn)) {
2726 break;
2727 }
2728 }
2729 result = proj_in->in(TypeFunc::Memory);
2730 }
2731 } else if (result->is_MergeMem()) {
2732 MergeMemNode *mmem = result->as_MergeMem();
2733 result = step_through_mergemem(mmem, alias_idx, toop);
2734 if (result == mmem->base_memory()) {
2735 // Didn't find instance memory, search through general slice recursively.
2736 result = mmem->memory_at(C->get_general_index(alias_idx));
2737 result = find_inst_mem(result, alias_idx, orig_phis);
2738 if (C->failing()) {
2739 return NULL;
2740 }
2741 mmem->set_memory_at(alias_idx, result);
2742 }
2743 } else if (result->is_Phi() &&
2744 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2745 Node *un = result->as_Phi()->unique_input(igvn);
2746 if (un != NULL) {
2747 orig_phis.append_if_missing(result->as_Phi());
2748 result = un;
2749 } else {
2750 break;
2751 }
2752 } else if (result->is_ClearArray()) {
2753 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2754 // Can not bypass initialization of the instance
2755 // we are looking for.
2756 break;
2757 }
2758 // Otherwise skip it (the call updated 'result' value).
2759 } else if (result->Opcode() == Op_SCMemProj) {
2760 Node* mem = result->in(0);
2761 Node* adr = NULL;
2762 if (mem->is_LoadStore()) {
2763 adr = mem->in(MemNode::Address);
2764 } else {
2765 assert(mem->Opcode() == Op_EncodeISOArray ||
2766 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2767 adr = mem->in(3); // Memory edge corresponds to destination array
2768 }
2769 const Type *at = igvn->type(adr);
2770 if (at != Type::TOP) {
2771 assert(at->isa_ptr() != NULL, "pointer type required.");
2772 int idx = C->get_alias_index(at->is_ptr());
2773 if (idx == alias_idx) {
2774 // Assert in debug mode
2775 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2776 break; // In product mode return SCMemProj node
2777 }
2778 }
2779 result = mem->in(MemNode::Memory);
2780 } else if (result->Opcode() == Op_StrInflatedCopy) {
2781 Node* adr = result->in(3); // Memory edge corresponds to destination array
2782 const Type *at = igvn->type(adr);
2783 if (at != Type::TOP) {
2784 assert(at->isa_ptr() != NULL, "pointer type required.");
2785 int idx = C->get_alias_index(at->is_ptr());
2786 if (idx == alias_idx) {
2787 // Assert in debug mode
2788 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2789 break; // In product mode return SCMemProj node
2790 }
2791 }
2792 result = result->in(MemNode::Memory);
2793 }
2794 }
2795 if (result->is_Phi()) {
2796 PhiNode *mphi = result->as_Phi();
2797 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2798 const TypePtr *t = mphi->adr_type();
2799 if (!is_instance) {
2800 // Push all non-instance Phis on the orig_phis worklist to update inputs
2801 // during Phase 4 if needed.
2802 orig_phis.append_if_missing(mphi);
2803 } else if (C->get_alias_index(t) != alias_idx) {
2804 // Create a new Phi with the specified alias index type.
2805 result = split_memory_phi(mphi, alias_idx, orig_phis);
2806 }
2807 }
2808 // the result is either MemNode, PhiNode, InitializeNode.
2809 return result;
2810 }
2811
2812 //
2813 // Convert the types of unescaped object to instance types where possible,
2814 // propagate the new type information through the graph, and update memory
2815 // edges and MergeMem inputs to reflect the new type.
2816 //
2817 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2818 // The processing is done in 4 phases:
2819 //
2820 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2821 // types for the CheckCastPP for allocations where possible.
2822 // Propagate the new types through users as follows:
2823 // casts and Phi: push users on alloc_worklist
2824 // AddP: cast Base and Address inputs to the instance type
2825 // push any AddP users on alloc_worklist and push any memnode
2826 // users onto memnode_worklist.
2827 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2828 // search the Memory chain for a store with the appropriate type
2829 // address type. If a Phi is found, create a new version with
2830 // the appropriate memory slices from each of the Phi inputs.
2831 // For stores, process the users as follows:
2832 // MemNode: push on memnode_worklist
2833 // MergeMem: push on mergemem_worklist
2834 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2835 // moving the first node encountered of each instance type to the
2836 // the input corresponding to its alias index.
2837 // appropriate memory slice.
2838 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2839 //
2840 // In the following example, the CheckCastPP nodes are the cast of allocation
2841 // results and the allocation of node 29 is unescaped and eligible to be an
2842 // instance type.
2843 //
2844 // We start with:
2845 //
2846 // 7 Parm #memory
2847 // 10 ConI "12"
2848 // 19 CheckCastPP "Foo"
2849 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2850 // 29 CheckCastPP "Foo"
2851 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2852 //
2853 // 40 StoreP 25 7 20 ... alias_index=4
2854 // 50 StoreP 35 40 30 ... alias_index=4
2855 // 60 StoreP 45 50 20 ... alias_index=4
2856 // 70 LoadP _ 60 30 ... alias_index=4
2857 // 80 Phi 75 50 60 Memory alias_index=4
2858 // 90 LoadP _ 80 30 ... alias_index=4
2859 // 100 LoadP _ 80 20 ... alias_index=4
2860 //
2861 //
2862 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2863 // and creating a new alias index for node 30. This gives:
2864 //
2865 // 7 Parm #memory
2866 // 10 ConI "12"
2867 // 19 CheckCastPP "Foo"
2868 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2869 // 29 CheckCastPP "Foo" iid=24
2870 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2871 //
2872 // 40 StoreP 25 7 20 ... alias_index=4
2873 // 50 StoreP 35 40 30 ... alias_index=6
2874 // 60 StoreP 45 50 20 ... alias_index=4
2875 // 70 LoadP _ 60 30 ... alias_index=6
2876 // 80 Phi 75 50 60 Memory alias_index=4
2877 // 90 LoadP _ 80 30 ... alias_index=6
2878 // 100 LoadP _ 80 20 ... alias_index=4
2879 //
2880 // In phase 2, new memory inputs are computed for the loads and stores,
2881 // And a new version of the phi is created. In phase 4, the inputs to
2882 // node 80 are updated and then the memory nodes are updated with the
2883 // values computed in phase 2. This results in:
2884 //
2885 // 7 Parm #memory
2886 // 10 ConI "12"
2887 // 19 CheckCastPP "Foo"
2888 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2889 // 29 CheckCastPP "Foo" iid=24
2890 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2891 //
2892 // 40 StoreP 25 7 20 ... alias_index=4
2893 // 50 StoreP 35 7 30 ... alias_index=6
2894 // 60 StoreP 45 40 20 ... alias_index=4
2895 // 70 LoadP _ 50 30 ... alias_index=6
2896 // 80 Phi 75 40 60 Memory alias_index=4
2897 // 120 Phi 75 50 50 Memory alias_index=6
2898 // 90 LoadP _ 120 30 ... alias_index=6
2899 // 100 LoadP _ 80 20 ... alias_index=4
2900 //
2901 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2902 GrowableArray<Node *> memnode_worklist;
2903 GrowableArray<PhiNode *> orig_phis;
2904 PhaseIterGVN *igvn = _igvn;
2905 uint new_index_start = (uint) _compile->num_alias_types();
2906 Arena* arena = Thread::current()->resource_area();
2907 VectorSet visited(arena);
2908 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2909 uint unique_old = _compile->unique();
2910
2911 // Phase 1: Process possible allocations from alloc_worklist.
2912 // Create instance types for the CheckCastPP for allocations where possible.
2913 //
2914 // (Note: don't forget to change the order of the second AddP node on
2915 // the alloc_worklist if the order of the worklist processing is changed,
2916 // see the comment in find_second_addp().)
2917 //
2918 while (alloc_worklist.length() != 0) {
2919 Node *n = alloc_worklist.pop();
2920 uint ni = n->_idx;
2921 if (n->is_Call()) {
2922 CallNode *alloc = n->as_Call();
2923 // copy escape information to call node
2924 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2925 PointsToNode::EscapeState es = ptn->escape_state();
2926 // We have an allocation or call which returns a Java object,
2927 // see if it is unescaped.
2928 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2929 continue;
2930 // Find CheckCastPP for the allocate or for the return value of a call
2931 n = alloc->result_cast();
2932 if (n == NULL) { // No uses except Initialize node
2933 if (alloc->is_Allocate()) {
2934 // Set the scalar_replaceable flag for allocation
2935 // so it could be eliminated if it has no uses.
2936 alloc->as_Allocate()->_is_scalar_replaceable = true;
2937 }
2938 if (alloc->is_CallStaticJava()) {
2939 // Set the scalar_replaceable flag for boxing method
2940 // so it could be eliminated if it has no uses.
2941 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2942 }
2943 continue;
2944 }
2945 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2946 assert(!alloc->is_Allocate(), "allocation should have unique type");
2947 continue;
2948 }
2949
2950 // The inline code for Object.clone() casts the allocation result to
2951 // java.lang.Object and then to the actual type of the allocated
2952 // object. Detect this case and use the second cast.
2953 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2954 // the allocation result is cast to java.lang.Object and then
2955 // to the actual Array type.
2956 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2957 && (alloc->is_AllocateArray() ||
2958 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2959 Node *cast2 = NULL;
2960 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2961 Node *use = n->fast_out(i);
2962 if (use->is_CheckCastPP()) {
2963 cast2 = use;
2964 break;
2965 }
2966 }
2967 if (cast2 != NULL) {
2968 n = cast2;
2969 } else {
2970 // Non-scalar replaceable if the allocation type is unknown statically
2971 // (reflection allocation), the object can't be restored during
2972 // deoptimization without precise type.
2973 continue;
2974 }
2975 }
2976
2977 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2978 if (t == NULL)
2979 continue; // not a TypeOopPtr
2980 if (!t->klass_is_exact())
2981 continue; // not an unique type
2982
2983 if (alloc->is_Allocate()) {
2984 // Set the scalar_replaceable flag for allocation
2985 // so it could be eliminated.
2986 alloc->as_Allocate()->_is_scalar_replaceable = true;
2987 }
2988 if (alloc->is_CallStaticJava()) {
2989 // Set the scalar_replaceable flag for boxing method
2990 // so it could be eliminated.
2991 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2992 }
2993 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2994 // in order for an object to be scalar-replaceable, it must be:
2995 // - a direct allocation (not a call returning an object)
2996 // - non-escaping
2997 // - eligible to be a unique type
2998 // - not determined to be ineligible by escape analysis
2999 set_map(alloc, n);
3000 set_map(n, alloc);
3001 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3002 igvn->hash_delete(n);
3003 igvn->set_type(n, tinst);
3004 n->raise_bottom_type(tinst);
3005 igvn->hash_insert(n);
3006 record_for_optimizer(n);
3007 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3008
3009 // First, put on the worklist all Field edges from Connection Graph
3010 // which is more accurate than putting immediate users from Ideal Graph.
3011 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3012 PointsToNode* tgt = e.get();
3013 if (tgt->is_Arraycopy()) {
3014 continue;
3015 }
3016 Node* use = tgt->ideal_node();
3017 assert(tgt->is_Field() && use->is_AddP(),
3018 "only AddP nodes are Field edges in CG");
3019 if (use->outcnt() > 0) { // Don't process dead nodes
3020 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3021 if (addp2 != NULL) {
3022 assert(alloc->is_AllocateArray(),"array allocation was expected");
3023 alloc_worklist.append_if_missing(addp2);
3024 }
3025 alloc_worklist.append_if_missing(use);
3026 }
3027 }
3028
3029 // An allocation may have an Initialize which has raw stores. Scan
3030 // the users of the raw allocation result and push AddP users
3031 // on alloc_worklist.
3032 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3033 assert (raw_result != NULL, "must have an allocation result");
3034 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3035 Node *use = raw_result->fast_out(i);
3036 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3037 Node* addp2 = find_second_addp(use, raw_result);
3038 if (addp2 != NULL) {
3039 assert(alloc->is_AllocateArray(),"array allocation was expected");
3040 alloc_worklist.append_if_missing(addp2);
3041 }
3042 alloc_worklist.append_if_missing(use);
3043 } else if (use->is_MemBar()) {
3044 memnode_worklist.append_if_missing(use);
3045 }
3046 }
3047 }
3048 } else if (n->is_AddP()) {
3049 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3050 if (jobj == NULL || jobj == phantom_obj) {
3051 #ifdef ASSERT
3052 ptnode_adr(get_addp_base(n)->_idx)->dump();
3053 ptnode_adr(n->_idx)->dump();
3054 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3055 #endif
3056 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3057 return;
3058 }
3059 Node *base = get_map(jobj->idx()); // CheckCastPP node
3060 if (!split_AddP(n, base)) continue; // wrong type from dead path
3061 } else if (n->is_Phi() ||
3062 n->is_CheckCastPP() ||
3063 n->is_EncodeP() ||
3064 n->is_DecodeN() ||
3065 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3066 if (visited.test_set(n->_idx)) {
3067 assert(n->is_Phi(), "loops only through Phi's");
3068 continue; // already processed
3069 }
3070 JavaObjectNode* jobj = unique_java_object(n);
3071 if (jobj == NULL || jobj == phantom_obj) {
3072 #ifdef ASSERT
3073 ptnode_adr(n->_idx)->dump();
3074 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3075 #endif
3076 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3077 return;
3078 } else {
3079 Node *val = get_map(jobj->idx()); // CheckCastPP node
3080 TypeNode *tn = n->as_Type();
3081 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3082 assert(tinst != NULL && tinst->is_known_instance() &&
3083 tinst->instance_id() == jobj->idx() , "instance type expected.");
3084
3085 const Type *tn_type = igvn->type(tn);
3086 const TypeOopPtr *tn_t;
3087 if (tn_type->isa_narrowoop()) {
3088 tn_t = tn_type->make_ptr()->isa_oopptr();
3089 } else {
3090 tn_t = tn_type->isa_oopptr();
3091 }
3092 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3093 if (tn_type->isa_narrowoop()) {
3094 tn_type = tinst->make_narrowoop();
3095 } else {
3096 tn_type = tinst;
3097 }
3098 igvn->hash_delete(tn);
3099 igvn->set_type(tn, tn_type);
3100 tn->set_type(tn_type);
3101 igvn->hash_insert(tn);
3102 record_for_optimizer(n);
3103 } else {
3104 assert(tn_type == TypePtr::NULL_PTR ||
3105 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3106 "unexpected type");
3107 continue; // Skip dead path with different type
3108 }
3109 }
3110 } else {
3111 debug_only(n->dump();)
3112 assert(false, "EA: unexpected node");
3113 continue;
3114 }
3115 // push allocation's users on appropriate worklist
3116 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3117 Node *use = n->fast_out(i);
3118 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3119 // Load/store to instance's field
3120 memnode_worklist.append_if_missing(use);
3121 } else if (use->is_MemBar()) {
3122 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3123 memnode_worklist.append_if_missing(use);
3124 }
3125 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3126 Node* addp2 = find_second_addp(use, n);
3127 if (addp2 != NULL) {
3128 alloc_worklist.append_if_missing(addp2);
3129 }
3130 alloc_worklist.append_if_missing(use);
3131 } else if (use->is_Phi() ||
3132 use->is_CheckCastPP() ||
3133 use->is_EncodeNarrowPtr() ||
3134 use->is_DecodeNarrowPtr() ||
3135 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3136 alloc_worklist.append_if_missing(use);
3137 #ifdef ASSERT
3138 } else if (use->is_Mem()) {
3139 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3140 } else if (use->is_MergeMem()) {
3141 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3142 } else if (use->is_SafePoint()) {
3143 // Look for MergeMem nodes for calls which reference unique allocation
3144 // (through CheckCastPP nodes) even for debug info.
3145 Node* m = use->in(TypeFunc::Memory);
3146 if (m->is_MergeMem()) {
3147 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3148 }
3149 } else if (use->Opcode() == Op_EncodeISOArray) {
3150 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3151 // EncodeISOArray overwrites destination array
3152 memnode_worklist.append_if_missing(use);
3153 }
3154 } else {
3155 uint op = use->Opcode();
3156 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3157 (use->in(MemNode::Memory) == n)) {
3158 // They overwrite memory edge corresponding to destination array,
3159 memnode_worklist.append_if_missing(use);
3160 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3161 op == Op_CastP2X || op == Op_StoreCM ||
3162 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3163 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3164 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3165 n->dump();
3166 use->dump();
3167 assert(false, "EA: missing allocation reference path");
3168 }
3169 #endif
3170 }
3171 }
3172
3173 }
3174
3175 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3176 // type, record it in the ArrayCopy node so we know what memory this
3177 // node uses/modified.
3178 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3179 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3180 Node* dest = ac->in(ArrayCopyNode::Dest);
3181 if (dest->is_AddP()) {
3182 dest = get_addp_base(dest);
3183 }
3184 JavaObjectNode* jobj = unique_java_object(dest);
3185 if (jobj != NULL) {
3186 Node *base = get_map(jobj->idx());
3187 if (base != NULL) {
3188 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3189 ac->_dest_type = base_t;
3190 }
3191 }
3192 Node* src = ac->in(ArrayCopyNode::Src);
3193 if (src->is_AddP()) {
3194 src = get_addp_base(src);
3195 }
3196 jobj = unique_java_object(src);
3197 if (jobj != NULL) {
3198 Node* base = get_map(jobj->idx());
3199 if (base != NULL) {
3200 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3201 ac->_src_type = base_t;
3202 }
3203 }
3204 }
3205
3206 // New alias types were created in split_AddP().
3207 uint new_index_end = (uint) _compile->num_alias_types();
3208 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3209
3210 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3211 // compute new values for Memory inputs (the Memory inputs are not
3212 // actually updated until phase 4.)
3213 if (memnode_worklist.length() == 0)
3214 return; // nothing to do
3215 while (memnode_worklist.length() != 0) {
3216 Node *n = memnode_worklist.pop();
3217 if (visited.test_set(n->_idx))
3218 continue;
3219 if (n->is_Phi() || n->is_ClearArray()) {
3220 // we don't need to do anything, but the users must be pushed
3221 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3222 // we don't need to do anything, but the users must be pushed
3223 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3224 if (n == NULL)
3225 continue;
3226 } else if (n->Opcode() == Op_StrCompressedCopy ||
3227 n->Opcode() == Op_EncodeISOArray) {
3228 // get the memory projection
3229 n = n->find_out_with(Op_SCMemProj);
3230 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3231 } else {
3232 assert(n->is_Mem(), "memory node required.");
3233 Node *addr = n->in(MemNode::Address);
3234 const Type *addr_t = igvn->type(addr);
3235 if (addr_t == Type::TOP)
3236 continue;
3237 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3238 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3239 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3240 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3241 if (_compile->failing()) {
3242 return;
3243 }
3244 if (mem != n->in(MemNode::Memory)) {
3245 // We delay the memory edge update since we need old one in
3246 // MergeMem code below when instances memory slices are separated.
3247 set_map(n, mem);
3248 }
3249 if (n->is_Load()) {
3250 continue; // don't push users
3251 } else if (n->is_LoadStore()) {
3252 // get the memory projection
3253 n = n->find_out_with(Op_SCMemProj);
3254 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3255 }
3256 }
3257 // push user on appropriate worklist
3258 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3259 Node *use = n->fast_out(i);
3260 if (use->is_Phi() || use->is_ClearArray()) {
3261 memnode_worklist.append_if_missing(use);
3262 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3263 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3264 continue;
3265 memnode_worklist.append_if_missing(use);
3266 } else if (use->is_MemBar()) {
3267 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3268 memnode_worklist.append_if_missing(use);
3269 }
3270 #ifdef ASSERT
3271 } else if(use->is_Mem()) {
3272 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3273 } else if (use->is_MergeMem()) {
3274 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3275 } else if (use->Opcode() == Op_EncodeISOArray) {
3276 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3277 // EncodeISOArray overwrites destination array
3278 memnode_worklist.append_if_missing(use);
3279 }
3280 } else {
3281 uint op = use->Opcode();
3282 if ((use->in(MemNode::Memory) == n) &&
3283 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3284 // They overwrite memory edge corresponding to destination array,
3285 memnode_worklist.append_if_missing(use);
3286 } else if (!(op == Op_StoreCM ||
3287 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3288 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3289 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3290 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3291 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3292 n->dump();
3293 use->dump();
3294 assert(false, "EA: missing memory path");
3295 }
3296 #endif
3297 }
3298 }
3299 }
3300
3301 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3302 // Walk each memory slice moving the first node encountered of each
3303 // instance type to the the input corresponding to its alias index.
3304 uint length = _mergemem_worklist.length();
3305 for( uint next = 0; next < length; ++next ) {
3306 MergeMemNode* nmm = _mergemem_worklist.at(next);
3307 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3308 // Note: we don't want to use MergeMemStream here because we only want to
3309 // scan inputs which exist at the start, not ones we add during processing.
3310 // Note 2: MergeMem may already contains instance memory slices added
3311 // during find_inst_mem() call when memory nodes were processed above.
3312 igvn->hash_delete(nmm);
3313 uint nslices = MIN2(nmm->req(), new_index_start);
3314 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3315 Node* mem = nmm->in(i);
3316 Node* cur = NULL;
3317 if (mem == NULL || mem->is_top())
3318 continue;
3319 // First, update mergemem by moving memory nodes to corresponding slices
3320 // if their type became more precise since this mergemem was created.
3321 while (mem->is_Mem()) {
3322 const Type *at = igvn->type(mem->in(MemNode::Address));
3323 if (at != Type::TOP) {
3324 assert (at->isa_ptr() != NULL, "pointer type required.");
3325 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3326 if (idx == i) {
3327 if (cur == NULL)
3328 cur = mem;
3329 } else {
3330 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3331 nmm->set_memory_at(idx, mem);
3332 }
3333 }
3334 }
3335 mem = mem->in(MemNode::Memory);
3336 }
3337 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3338 // Find any instance of the current type if we haven't encountered
3339 // already a memory slice of the instance along the memory chain.
3340 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3341 if((uint)_compile->get_general_index(ni) == i) {
3342 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3343 if (nmm->is_empty_memory(m)) {
3344 Node* result = find_inst_mem(mem, ni, orig_phis);
3345 if (_compile->failing()) {
3346 return;
3347 }
3348 nmm->set_memory_at(ni, result);
3349 }
3350 }
3351 }
3352 }
3353 // Find the rest of instances values
3354 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3355 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3356 Node* result = step_through_mergemem(nmm, ni, tinst);
3357 if (result == nmm->base_memory()) {
3358 // Didn't find instance memory, search through general slice recursively.
3359 result = nmm->memory_at(_compile->get_general_index(ni));
3360 result = find_inst_mem(result, ni, orig_phis);
3361 if (_compile->failing()) {
3362 return;
3363 }
3364 nmm->set_memory_at(ni, result);
3365 }
3366 }
3367 igvn->hash_insert(nmm);
3368 record_for_optimizer(nmm);
3369 }
3370
3371 // Phase 4: Update the inputs of non-instance memory Phis and
3372 // the Memory input of memnodes
3373 // First update the inputs of any non-instance Phi's from
3374 // which we split out an instance Phi. Note we don't have
3375 // to recursively process Phi's encounted on the input memory
3376 // chains as is done in split_memory_phi() since they will
3377 // also be processed here.
3378 for (int j = 0; j < orig_phis.length(); j++) {
3379 PhiNode *phi = orig_phis.at(j);
3380 int alias_idx = _compile->get_alias_index(phi->adr_type());
3381 igvn->hash_delete(phi);
3382 for (uint i = 1; i < phi->req(); i++) {
3383 Node *mem = phi->in(i);
3384 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3385 if (_compile->failing()) {
3386 return;
3387 }
3388 if (mem != new_mem) {
3389 phi->set_req(i, new_mem);
3390 }
3391 }
3392 igvn->hash_insert(phi);
3393 record_for_optimizer(phi);
3394 }
3395
3396 // Update the memory inputs of MemNodes with the value we computed
3397 // in Phase 2 and move stores memory users to corresponding memory slices.
3398 // Disable memory split verification code until the fix for 6984348.
3399 // Currently it produces false negative results since it does not cover all cases.
3400 #if 0 // ifdef ASSERT
3401 visited.Reset();
3402 Node_Stack old_mems(arena, _compile->unique() >> 2);
3403 #endif
3404 for (uint i = 0; i < ideal_nodes.size(); i++) {
3405 Node* n = ideal_nodes.at(i);
3406 Node* nmem = get_map(n->_idx);
3407 assert(nmem != NULL, "sanity");
3408 if (n->is_Mem()) {
3409 #if 0 // ifdef ASSERT
3410 Node* old_mem = n->in(MemNode::Memory);
3411 if (!visited.test_set(old_mem->_idx)) {
3412 old_mems.push(old_mem, old_mem->outcnt());
3413 }
3414 #endif
3415 assert(n->in(MemNode::Memory) != nmem, "sanity");
3416 if (!n->is_Load()) {
3417 // Move memory users of a store first.
3418 move_inst_mem(n, orig_phis);
3419 }
3420 // Now update memory input
3421 igvn->hash_delete(n);
3422 n->set_req(MemNode::Memory, nmem);
3423 igvn->hash_insert(n);
3424 record_for_optimizer(n);
3425 } else {
3426 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3427 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3428 }
3429 }
3430 #if 0 // ifdef ASSERT
3431 // Verify that memory was split correctly
3432 while (old_mems.is_nonempty()) {
3433 Node* old_mem = old_mems.node();
3434 uint old_cnt = old_mems.index();
3435 old_mems.pop();
3436 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3437 }
3438 #endif
3439 }
3440
3441 #ifndef PRODUCT
3442 static const char *node_type_names[] = {
3443 "UnknownType",
3444 "JavaObject",
3445 "LocalVar",
3446 "Field",
3447 "Arraycopy"
3448 };
3449
3450 static const char *esc_names[] = {
3451 "UnknownEscape",
3452 "NoEscape",
3453 "ArgEscape",
3454 "GlobalEscape"
3455 };
3456
3457 void PointsToNode::dump(bool print_state) const {
3458 NodeType nt = node_type();
3459 tty->print("%s ", node_type_names[(int) nt]);
3460 if (print_state) {
3461 EscapeState es = escape_state();
3462 EscapeState fields_es = fields_escape_state();
3463 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3464 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3465 tty->print("NSR ");
3466 }
3467 if (is_Field()) {
3468 FieldNode* f = (FieldNode*)this;
3469 if (f->is_oop())
3470 tty->print("oop ");
3471 if (f->offset() > 0)
3472 tty->print("+%d ", f->offset());
3473 tty->print("(");
3474 for (BaseIterator i(f); i.has_next(); i.next()) {
3475 PointsToNode* b = i.get();
3476 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3477 }
3478 tty->print(" )");
3479 }
3480 tty->print("[");
3481 for (EdgeIterator i(this); i.has_next(); i.next()) {
3482 PointsToNode* e = i.get();
3483 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3484 }
3485 tty->print(" [");
3486 for (UseIterator i(this); i.has_next(); i.next()) {
3487 PointsToNode* u = i.get();
3488 bool is_base = false;
3489 if (PointsToNode::is_base_use(u)) {
3490 is_base = true;
3491 u = PointsToNode::get_use_node(u)->as_Field();
3492 }
3493 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3494 }
3495 tty->print(" ]] ");
3496 if (_node == NULL)
3497 tty->print_cr("<null>");
3498 else
3499 _node->dump();
3500 }
3501
3502 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3503 bool first = true;
3504 int ptnodes_length = ptnodes_worklist.length();
3505 for (int i = 0; i < ptnodes_length; i++) {
3506 PointsToNode *ptn = ptnodes_worklist.at(i);
3507 if (ptn == NULL || !ptn->is_JavaObject())
3508 continue;
3509 PointsToNode::EscapeState es = ptn->escape_state();
3510 if ((es != PointsToNode::NoEscape) && !Verbose) {
3511 continue;
3512 }
3513 Node* n = ptn->ideal_node();
3514 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3515 n->as_CallStaticJava()->is_boxing_method())) {
3516 if (first) {
3517 tty->cr();
3518 tty->print("======== Connection graph for ");
3519 _compile->method()->print_short_name();
3520 tty->cr();
3521 first = false;
3522 }
3523 ptn->dump();
3524 // Print all locals and fields which reference this allocation
3525 for (UseIterator j(ptn); j.has_next(); j.next()) {
3526 PointsToNode* use = j.get();
3527 if (use->is_LocalVar()) {
3528 use->dump(Verbose);
3529 } else if (Verbose) {
3530 use->dump();
3531 }
3532 }
3533 tty->cr();
3534 }
3535 }
3536 }
3537 #endif