1 /*
2 * Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "gc/shared/c2BarrierSetCodeGen.hpp"
29 #include "libadt/vectset.hpp"
30 #include "memory/allocation.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "opto/c2compiler.hpp"
33 #include "opto/arraycopynode.hpp"
34 #include "opto/callnode.hpp"
35 #include "opto/cfgnode.hpp"
36 #include "opto/compile.hpp"
37 #include "opto/escape.hpp"
38 #include "opto/phaseX.hpp"
39 #include "opto/movenode.hpp"
40 #include "opto/rootnode.hpp"
41
42 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
43 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
44 _in_worklist(C->comp_arena()),
45 _next_pidx(0),
46 _collecting(true),
47 _verify(false),
48 _compile(C),
49 _igvn(igvn),
50 _node_map(C->comp_arena()) {
51 // Add unknown java object.
52 add_java_object(C->top(), PointsToNode::GlobalEscape);
53 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
54 // Add ConP(#NULL) and ConN(#NULL) nodes.
55 Node* oop_null = igvn->zerocon(T_OBJECT);
56 assert(oop_null->_idx < nodes_size(), "should be created already");
57 add_java_object(oop_null, PointsToNode::NoEscape);
58 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
59 if (UseCompressedOops) {
60 Node* noop_null = igvn->zerocon(T_NARROWOOP);
61 assert(noop_null->_idx < nodes_size(), "should be created already");
62 map_ideal_node(noop_null, null_obj);
63 }
64 _pcmp_neq = NULL; // Should be initialized
65 _pcmp_eq = NULL;
66 }
67
68 bool ConnectionGraph::has_candidates(Compile *C) {
69 // EA brings benefits only when the code has allocations and/or locks which
70 // are represented by ideal Macro nodes.
71 int cnt = C->macro_count();
72 for (int i = 0; i < cnt; i++) {
73 Node *n = C->macro_node(i);
74 if (n->is_Allocate())
75 return true;
76 if (n->is_Lock()) {
77 Node* obj = n->as_Lock()->obj_node()->uncast();
78 if (!(obj->is_Parm() || obj->is_Con()))
79 return true;
80 }
81 if (n->is_CallStaticJava() &&
82 n->as_CallStaticJava()->is_boxing_method()) {
83 return true;
84 }
85 }
86 return false;
87 }
88
89 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
90 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
91 ResourceMark rm;
92
93 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
94 // to create space for them in ConnectionGraph::_nodes[].
95 Node* oop_null = igvn->zerocon(T_OBJECT);
96 Node* noop_null = igvn->zerocon(T_NARROWOOP);
97 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
98 // Perform escape analysis
99 if (congraph->compute_escape()) {
100 // There are non escaping objects.
101 C->set_congraph(congraph);
102 }
103 // Cleanup.
104 if (oop_null->outcnt() == 0)
105 igvn->hash_delete(oop_null);
106 if (noop_null->outcnt() == 0)
107 igvn->hash_delete(noop_null);
108 }
109
110 bool ConnectionGraph::compute_escape() {
111 Compile* C = _compile;
112 PhaseGVN* igvn = _igvn;
113
114 // Worklists used by EA.
115 Unique_Node_List delayed_worklist;
116 GrowableArray<Node*> alloc_worklist;
117 GrowableArray<Node*> ptr_cmp_worklist;
118 GrowableArray<Node*> storestore_worklist;
119 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
120 GrowableArray<PointsToNode*> ptnodes_worklist;
121 GrowableArray<JavaObjectNode*> java_objects_worklist;
122 GrowableArray<JavaObjectNode*> non_escaped_worklist;
123 GrowableArray<FieldNode*> oop_fields_worklist;
124 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
125
126 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
127
128 // 1. Populate Connection Graph (CG) with PointsTo nodes.
129 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
130 // Initialize worklist
131 if (C->root() != NULL) {
132 ideal_nodes.push(C->root());
133 }
134 // Processed ideal nodes are unique on ideal_nodes list
135 // but several ideal nodes are mapped to the phantom_obj.
136 // To avoid duplicated entries on the following worklists
137 // add the phantom_obj only once to them.
138 ptnodes_worklist.append(phantom_obj);
139 java_objects_worklist.append(phantom_obj);
140 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
141 Node* n = ideal_nodes.at(next);
142 // Create PointsTo nodes and add them to Connection Graph. Called
143 // only once per ideal node since ideal_nodes is Unique_Node list.
144 add_node_to_connection_graph(n, &delayed_worklist);
145 PointsToNode* ptn = ptnode_adr(n->_idx);
146 if (ptn != NULL && ptn != phantom_obj) {
147 ptnodes_worklist.append(ptn);
148 if (ptn->is_JavaObject()) {
149 java_objects_worklist.append(ptn->as_JavaObject());
150 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
151 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
152 // Only allocations and java static calls results are interesting.
153 non_escaped_worklist.append(ptn->as_JavaObject());
154 }
155 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
156 oop_fields_worklist.append(ptn->as_Field());
157 }
158 }
159 if (n->is_MergeMem()) {
160 // Collect all MergeMem nodes to add memory slices for
161 // scalar replaceable objects in split_unique_types().
162 _mergemem_worklist.append(n->as_MergeMem());
163 } else if (OptimizePtrCompare && n->is_Cmp() &&
164 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
165 // Collect compare pointers nodes.
166 ptr_cmp_worklist.append(n);
167 } else if (n->is_MemBarStoreStore()) {
168 // Collect all MemBarStoreStore nodes so that depending on the
169 // escape status of the associated Allocate node some of them
170 // may be eliminated.
171 storestore_worklist.append(n);
172 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
173 (n->req() > MemBarNode::Precedent)) {
174 record_for_optimizer(n);
175 #ifdef ASSERT
176 } else if (n->is_AddP()) {
177 // Collect address nodes for graph verification.
178 addp_worklist.append(n);
179 #endif
180 } else if (n->is_ArrayCopy()) {
181 // Keep a list of ArrayCopy nodes so if one of its input is non
182 // escaping, we can record a unique type
183 arraycopy_worklist.append(n->as_ArrayCopy());
184 }
185 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
186 Node* m = n->fast_out(i); // Get user
187 ideal_nodes.push(m);
188 }
189 }
190 if (non_escaped_worklist.length() == 0) {
191 _collecting = false;
192 return false; // Nothing to do.
193 }
194 // Add final simple edges to graph.
195 while(delayed_worklist.size() > 0) {
196 Node* n = delayed_worklist.pop();
197 add_final_edges(n);
198 }
199 int ptnodes_length = ptnodes_worklist.length();
200
201 #ifdef ASSERT
202 if (VerifyConnectionGraph) {
203 // Verify that no new simple edges could be created and all
204 // local vars has edges.
205 _verify = true;
206 for (int next = 0; next < ptnodes_length; ++next) {
207 PointsToNode* ptn = ptnodes_worklist.at(next);
208 add_final_edges(ptn->ideal_node());
209 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
210 ptn->dump();
211 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
212 }
213 }
214 _verify = false;
215 }
216 #endif
217 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
218 // processing, calls to CI to resolve symbols (types, fields, methods)
219 // referenced in bytecode. During symbol resolution VM may throw
220 // an exception which CI cleans and converts to compilation failure.
221 if (C->failing()) return false;
222
223 // 2. Finish Graph construction by propagating references to all
224 // java objects through graph.
225 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
226 java_objects_worklist, oop_fields_worklist)) {
227 // All objects escaped or hit time or iterations limits.
228 _collecting = false;
229 return false;
230 }
231
232 // 3. Adjust scalar_replaceable state of nonescaping objects and push
233 // scalar replaceable allocations on alloc_worklist for processing
234 // in split_unique_types().
235 int non_escaped_length = non_escaped_worklist.length();
236 for (int next = 0; next < non_escaped_length; next++) {
237 JavaObjectNode* ptn = non_escaped_worklist.at(next);
238 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
239 Node* n = ptn->ideal_node();
240 if (n->is_Allocate()) {
241 n->as_Allocate()->_is_non_escaping = noescape;
242 }
243 if (n->is_CallStaticJava()) {
244 n->as_CallStaticJava()->_is_non_escaping = noescape;
245 }
246 if (noescape && ptn->scalar_replaceable()) {
247 adjust_scalar_replaceable_state(ptn);
248 if (ptn->scalar_replaceable()) {
249 alloc_worklist.append(ptn->ideal_node());
250 }
251 }
252 }
253
254 #ifdef ASSERT
255 if (VerifyConnectionGraph) {
256 // Verify that graph is complete - no new edges could be added or needed.
257 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
258 java_objects_worklist, addp_worklist);
259 }
260 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
261 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
262 null_obj->edge_count() == 0 &&
263 !null_obj->arraycopy_src() &&
264 !null_obj->arraycopy_dst(), "sanity");
265 #endif
266
267 _collecting = false;
268
269 } // TracePhase t3("connectionGraph")
270
271 // 4. Optimize ideal graph based on EA information.
272 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
273 if (has_non_escaping_obj) {
274 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
275 }
276
277 #ifndef PRODUCT
278 if (PrintEscapeAnalysis) {
279 dump(ptnodes_worklist); // Dump ConnectionGraph
280 }
281 #endif
282
283 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
284 #ifdef ASSERT
285 if (VerifyConnectionGraph) {
286 int alloc_length = alloc_worklist.length();
287 for (int next = 0; next < alloc_length; ++next) {
288 Node* n = alloc_worklist.at(next);
289 PointsToNode* ptn = ptnode_adr(n->_idx);
290 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
291 }
292 }
293 #endif
294
295 // 5. Separate memory graph for scalar replaceable allcations.
296 if (has_scalar_replaceable_candidates &&
297 C->AliasLevel() >= 3 && EliminateAllocations) {
298 // Now use the escape information to create unique types for
299 // scalar replaceable objects.
300 split_unique_types(alloc_worklist, arraycopy_worklist);
301 if (C->failing()) return false;
302 C->print_method(PHASE_AFTER_EA, 2);
303
304 #ifdef ASSERT
305 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
306 tty->print("=== No allocations eliminated for ");
307 C->method()->print_short_name();
308 if(!EliminateAllocations) {
309 tty->print(" since EliminateAllocations is off ===");
310 } else if(!has_scalar_replaceable_candidates) {
311 tty->print(" since there are no scalar replaceable candidates ===");
312 } else if(C->AliasLevel() < 3) {
313 tty->print(" since AliasLevel < 3 ===");
314 }
315 tty->cr();
316 #endif
317 }
318 return has_non_escaping_obj;
319 }
320
321 // Utility function for nodes that load an object
322 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
323 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
324 // ThreadLocal has RawPtr type.
325 const Type* t = _igvn->type(n);
326 if (t->make_ptr() != NULL) {
327 Node* adr = n->in(MemNode::Address);
328 #ifdef ASSERT
329 if (!adr->is_AddP()) {
330 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
331 } else {
332 assert((ptnode_adr(adr->_idx) == NULL ||
333 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
334 }
335 #endif
336 add_local_var_and_edge(n, PointsToNode::NoEscape,
337 adr, delayed_worklist);
338 }
339 }
340
341 // Populate Connection Graph with PointsTo nodes and create simple
342 // connection graph edges.
343 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
344 assert(!_verify, "this method should not be called for verification");
345 PhaseGVN* igvn = _igvn;
346 uint n_idx = n->_idx;
347 PointsToNode* n_ptn = ptnode_adr(n_idx);
348 if (n_ptn != NULL)
349 return; // No need to redefine PointsTo node during first iteration.
350
351 if (n->is_Call()) {
352 // Arguments to allocation and locking don't escape.
353 if (n->is_AbstractLock()) {
354 // Put Lock and Unlock nodes on IGVN worklist to process them during
355 // first IGVN optimization when escape information is still available.
356 record_for_optimizer(n);
357 } else if (n->is_Allocate()) {
358 add_call_node(n->as_Call());
359 record_for_optimizer(n);
360 } else {
361 if (n->is_CallStaticJava()) {
362 const char* name = n->as_CallStaticJava()->_name;
363 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
364 return; // Skip uncommon traps
365 }
366 // Don't mark as processed since call's arguments have to be processed.
367 delayed_worklist->push(n);
368 // Check if a call returns an object.
369 if ((n->as_Call()->returns_pointer() &&
370 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
371 (n->is_CallStaticJava() &&
372 n->as_CallStaticJava()->is_boxing_method())) {
373 add_call_node(n->as_Call());
374 }
375 }
376 return;
377 }
378 // Put this check here to process call arguments since some call nodes
379 // point to phantom_obj.
380 if (n_ptn == phantom_obj || n_ptn == null_obj)
381 return; // Skip predefined nodes.
382
383 int opcode = n->Opcode();
384 switch (opcode) {
385 case Op_AddP: {
386 Node* base = get_addp_base(n);
387 PointsToNode* ptn_base = ptnode_adr(base->_idx);
388 // Field nodes are created for all field types. They are used in
389 // adjust_scalar_replaceable_state() and split_unique_types().
390 // Note, non-oop fields will have only base edges in Connection
391 // Graph because such fields are not used for oop loads and stores.
392 int offset = address_offset(n, igvn);
393 add_field(n, PointsToNode::NoEscape, offset);
394 if (ptn_base == NULL) {
395 delayed_worklist->push(n); // Process it later.
396 } else {
397 n_ptn = ptnode_adr(n_idx);
398 add_base(n_ptn->as_Field(), ptn_base);
399 }
400 break;
401 }
402 case Op_CastX2P: {
403 map_ideal_node(n, phantom_obj);
404 break;
405 }
406 case Op_CastPP:
407 case Op_CheckCastPP:
408 case Op_EncodeP:
409 case Op_DecodeN:
410 case Op_EncodePKlass:
411 case Op_DecodeNKlass: {
412 add_local_var_and_edge(n, PointsToNode::NoEscape,
413 n->in(1), delayed_worklist);
414 break;
415 }
416 case Op_CMoveP: {
417 add_local_var(n, PointsToNode::NoEscape);
418 // Do not add edges during first iteration because some could be
419 // not defined yet.
420 delayed_worklist->push(n);
421 break;
422 }
423 case Op_ConP:
424 case Op_ConN:
425 case Op_ConNKlass: {
426 // assume all oop constants globally escape except for null
427 PointsToNode::EscapeState es;
428 const Type* t = igvn->type(n);
429 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
430 es = PointsToNode::NoEscape;
431 } else {
432 es = PointsToNode::GlobalEscape;
433 }
434 add_java_object(n, es);
435 break;
436 }
437 case Op_CreateEx: {
438 // assume that all exception objects globally escape
439 map_ideal_node(n, phantom_obj);
440 break;
441 }
442 case Op_LoadKlass:
443 case Op_LoadNKlass: {
444 // Unknown class is loaded
445 map_ideal_node(n, phantom_obj);
446 break;
447 }
448 case Op_LoadP:
449 case Op_LoadN:
450 case Op_LoadPLocked: {
451 add_objload_to_connection_graph(n, delayed_worklist);
452 break;
453 }
454 case Op_Parm: {
455 map_ideal_node(n, phantom_obj);
456 break;
457 }
458 case Op_PartialSubtypeCheck: {
459 // Produces Null or notNull and is used in only in CmpP so
460 // phantom_obj could be used.
461 map_ideal_node(n, phantom_obj); // Result is unknown
462 break;
463 }
464 case Op_Phi: {
465 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
466 // ThreadLocal has RawPtr type.
467 const Type* t = n->as_Phi()->type();
468 if (t->make_ptr() != NULL) {
469 add_local_var(n, PointsToNode::NoEscape);
470 // Do not add edges during first iteration because some could be
471 // not defined yet.
472 delayed_worklist->push(n);
473 }
474 break;
475 }
476 case Op_Proj: {
477 // we are only interested in the oop result projection from a call
478 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
479 n->in(0)->as_Call()->returns_pointer()) {
480 add_local_var_and_edge(n, PointsToNode::NoEscape,
481 n->in(0), delayed_worklist);
482 }
483 break;
484 }
485 case Op_Rethrow: // Exception object escapes
486 case Op_Return: {
487 if (n->req() > TypeFunc::Parms &&
488 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
489 // Treat Return value as LocalVar with GlobalEscape escape state.
490 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
491 n->in(TypeFunc::Parms), delayed_worklist);
492 }
493 break;
494 }
495 case Op_CompareAndExchangeP:
496 case Op_CompareAndExchangeN:
497 case Op_GetAndSetP:
498 case Op_GetAndSetN: {
499 add_objload_to_connection_graph(n, delayed_worklist);
500 // fallthrough
501 }
502 case Op_StoreP:
503 case Op_StoreN:
504 case Op_StoreNKlass:
505 case Op_StorePConditional:
506 case Op_WeakCompareAndSwapP:
507 case Op_WeakCompareAndSwapN:
508 case Op_CompareAndSwapP:
509 case Op_CompareAndSwapN: {
510 Node* adr = n->in(MemNode::Address);
511 const Type *adr_type = igvn->type(adr);
512 adr_type = adr_type->make_ptr();
513 if (adr_type == NULL) {
514 break; // skip dead nodes
515 }
516 if (adr_type->isa_oopptr() ||
517 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
518 (adr_type == TypeRawPtr::NOTNULL &&
519 adr->in(AddPNode::Address)->is_Proj() &&
520 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
521 delayed_worklist->push(n); // Process it later.
522 #ifdef ASSERT
523 assert(adr->is_AddP(), "expecting an AddP");
524 if (adr_type == TypeRawPtr::NOTNULL) {
525 // Verify a raw address for a store captured by Initialize node.
526 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
527 assert(offs != Type::OffsetBot, "offset must be a constant");
528 }
529 #endif
530 } else {
531 // Ignore copy the displaced header to the BoxNode (OSR compilation).
532 if (adr->is_BoxLock())
533 break;
534 // Stored value escapes in unsafe access.
535 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
536 // Pointer stores in G1 barriers looks like unsafe access.
537 // Ignore such stores to be able scalar replace non-escaping
538 // allocations.
539 if (UseG1GC && adr->is_AddP()) {
540 Node* base = get_addp_base(adr);
541 if (base->Opcode() == Op_LoadP &&
542 base->in(MemNode::Address)->is_AddP()) {
543 adr = base->in(MemNode::Address);
544 Node* tls = get_addp_base(adr);
545 if (tls->Opcode() == Op_ThreadLocal) {
546 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
547 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
548 SATBMarkQueue::byte_offset_of_buf())) {
549 break; // G1 pre barrier previous oop value store.
550 }
551 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
552 DirtyCardQueue::byte_offset_of_buf())) {
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 Universe::heap()->barrier_set()->c2_code_gen()->is_gc_barrier_node(call) ||
982 (call->as_CallLeaf()->_name != NULL &&
983 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
984 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
985 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
986 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
993 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1002 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1003 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1004 ))) {
1005 call->dump();
1006 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1007 }
1008 #endif
1009 // Always process arraycopy's destination object since
1010 // we need to add all possible edges to references in
1011 // source object.
1012 if (arg_esc >= PointsToNode::ArgEscape &&
1013 !arg_is_arraycopy_dest) {
1014 continue;
1015 }
1016 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1017 if (call->is_ArrayCopy()) {
1018 ArrayCopyNode* ac = call->as_ArrayCopy();
1019 if (ac->is_clonebasic() ||
1020 ac->is_arraycopy_validated() ||
1021 ac->is_copyof_validated() ||
1022 ac->is_copyofrange_validated()) {
1023 es = PointsToNode::NoEscape;
1024 }
1025 }
1026 set_escape_state(arg_ptn, es);
1027 if (arg_is_arraycopy_dest) {
1028 Node* src = call->in(TypeFunc::Parms);
1029 if (src->is_AddP()) {
1030 src = get_addp_base(src);
1031 }
1032 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1033 assert(src_ptn != NULL, "should be registered");
1034 if (arg_ptn != src_ptn) {
1035 // Special arraycopy edge:
1036 // A destination object's field can't have the source object
1037 // as base since objects escape states are not related.
1038 // Only escape state of destination object's fields affects
1039 // escape state of fields in source object.
1040 add_arraycopy(call, es, src_ptn, arg_ptn);
1041 }
1042 }
1043 }
1044 }
1045 break;
1046 }
1047 case Op_CallStaticJava: {
1048 // For a static call, we know exactly what method is being called.
1049 // Use bytecode estimator to record the call's escape affects
1050 #ifdef ASSERT
1051 const char* name = call->as_CallStaticJava()->_name;
1052 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1053 #endif
1054 ciMethod* meth = call->as_CallJava()->method();
1055 if ((meth != NULL) && meth->is_boxing_method()) {
1056 break; // Boxing methods do not modify any oops.
1057 }
1058 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1059 // fall-through if not a Java method or no analyzer information
1060 if (call_analyzer != NULL) {
1061 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1062 const TypeTuple* d = call->tf()->domain();
1063 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1064 const Type* at = d->field_at(i);
1065 int k = i - TypeFunc::Parms;
1066 Node* arg = call->in(i);
1067 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1068 if (at->isa_ptr() != NULL &&
1069 call_analyzer->is_arg_returned(k)) {
1070 // The call returns arguments.
1071 if (call_ptn != NULL) { // Is call's result used?
1072 assert(call_ptn->is_LocalVar(), "node should be registered");
1073 assert(arg_ptn != NULL, "node should be registered");
1074 add_edge(call_ptn, arg_ptn);
1075 }
1076 }
1077 if (at->isa_oopptr() != NULL &&
1078 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1079 if (!call_analyzer->is_arg_stack(k)) {
1080 // The argument global escapes
1081 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1082 } else {
1083 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1084 if (!call_analyzer->is_arg_local(k)) {
1085 // The argument itself doesn't escape, but any fields might
1086 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1087 }
1088 }
1089 }
1090 }
1091 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1092 // The call returns arguments.
1093 assert(call_ptn->edge_count() > 0, "sanity");
1094 if (!call_analyzer->is_return_local()) {
1095 // Returns also unknown object.
1096 add_edge(call_ptn, phantom_obj);
1097 }
1098 }
1099 break;
1100 }
1101 }
1102 default: {
1103 // Fall-through here if not a Java method or no analyzer information
1104 // or some other type of call, assume the worst case: all arguments
1105 // globally escape.
1106 const TypeTuple* d = call->tf()->domain();
1107 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1108 const Type* at = d->field_at(i);
1109 if (at->isa_oopptr() != NULL) {
1110 Node* arg = call->in(i);
1111 if (arg->is_AddP()) {
1112 arg = get_addp_base(arg);
1113 }
1114 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1115 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1116 }
1117 }
1118 }
1119 }
1120 }
1121
1122
1123 // Finish Graph construction.
1124 bool ConnectionGraph::complete_connection_graph(
1125 GrowableArray<PointsToNode*>& ptnodes_worklist,
1126 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1127 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1128 GrowableArray<FieldNode*>& oop_fields_worklist) {
1129 // Normally only 1-3 passes needed to build Connection Graph depending
1130 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1131 // Set limit to 20 to catch situation when something did go wrong and
1132 // bailout Escape Analysis.
1133 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1134 #define CG_BUILD_ITER_LIMIT 20
1135
1136 // Propagate GlobalEscape and ArgEscape escape states and check that
1137 // we still have non-escaping objects. The method pushs on _worklist
1138 // Field nodes which reference phantom_object.
1139 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1140 return false; // Nothing to do.
1141 }
1142 // Now propagate references to all JavaObject nodes.
1143 int java_objects_length = java_objects_worklist.length();
1144 elapsedTimer time;
1145 bool timeout = false;
1146 int new_edges = 1;
1147 int iterations = 0;
1148 do {
1149 while ((new_edges > 0) &&
1150 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1151 double start_time = time.seconds();
1152 time.start();
1153 new_edges = 0;
1154 // Propagate references to phantom_object for nodes pushed on _worklist
1155 // by find_non_escaped_objects() and find_field_value().
1156 new_edges += add_java_object_edges(phantom_obj, false);
1157 for (int next = 0; next < java_objects_length; ++next) {
1158 JavaObjectNode* ptn = java_objects_worklist.at(next);
1159 new_edges += add_java_object_edges(ptn, true);
1160
1161 #define SAMPLE_SIZE 4
1162 if ((next % SAMPLE_SIZE) == 0) {
1163 // Each 4 iterations calculate how much time it will take
1164 // to complete graph construction.
1165 time.stop();
1166 // Poll for requests from shutdown mechanism to quiesce compiler
1167 // because Connection graph construction may take long time.
1168 CompileBroker::maybe_block();
1169 double stop_time = time.seconds();
1170 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1171 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1172 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1173 timeout = true;
1174 break; // Timeout
1175 }
1176 start_time = stop_time;
1177 time.start();
1178 }
1179 #undef SAMPLE_SIZE
1180
1181 }
1182 if (timeout) break;
1183 if (new_edges > 0) {
1184 // Update escape states on each iteration if graph was updated.
1185 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1186 return false; // Nothing to do.
1187 }
1188 }
1189 time.stop();
1190 if (time.seconds() >= EscapeAnalysisTimeout) {
1191 timeout = true;
1192 break;
1193 }
1194 }
1195 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1196 time.start();
1197 // Find fields which have unknown value.
1198 int fields_length = oop_fields_worklist.length();
1199 for (int next = 0; next < fields_length; next++) {
1200 FieldNode* field = oop_fields_worklist.at(next);
1201 if (field->edge_count() == 0) {
1202 new_edges += find_field_value(field);
1203 // This code may added new edges to phantom_object.
1204 // Need an other cycle to propagate references to phantom_object.
1205 }
1206 }
1207 time.stop();
1208 if (time.seconds() >= EscapeAnalysisTimeout) {
1209 timeout = true;
1210 break;
1211 }
1212 } else {
1213 new_edges = 0; // Bailout
1214 }
1215 } while (new_edges > 0);
1216
1217 // Bailout if passed limits.
1218 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1219 Compile* C = _compile;
1220 if (C->log() != NULL) {
1221 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1222 C->log()->text("%s", timeout ? "time" : "iterations");
1223 C->log()->end_elem(" limit'");
1224 }
1225 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1226 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1227 // Possible infinite build_connection_graph loop,
1228 // bailout (no changes to ideal graph were made).
1229 return false;
1230 }
1231 #ifdef ASSERT
1232 if (Verbose && PrintEscapeAnalysis) {
1233 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1234 iterations, nodes_size(), ptnodes_worklist.length());
1235 }
1236 #endif
1237
1238 #undef CG_BUILD_ITER_LIMIT
1239
1240 // Find fields initialized by NULL for non-escaping Allocations.
1241 int non_escaped_length = non_escaped_worklist.length();
1242 for (int next = 0; next < non_escaped_length; next++) {
1243 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1244 PointsToNode::EscapeState es = ptn->escape_state();
1245 assert(es <= PointsToNode::ArgEscape, "sanity");
1246 if (es == PointsToNode::NoEscape) {
1247 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1248 // Adding references to NULL object does not change escape states
1249 // since it does not escape. Also no fields are added to NULL object.
1250 add_java_object_edges(null_obj, false);
1251 }
1252 }
1253 Node* n = ptn->ideal_node();
1254 if (n->is_Allocate()) {
1255 // The object allocated by this Allocate node will never be
1256 // seen by an other thread. Mark it so that when it is
1257 // expanded no MemBarStoreStore is added.
1258 InitializeNode* ini = n->as_Allocate()->initialization();
1259 if (ini != NULL)
1260 ini->set_does_not_escape();
1261 }
1262 }
1263 return true; // Finished graph construction.
1264 }
1265
1266 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1267 // and check that we still have non-escaping java objects.
1268 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1269 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1270 GrowableArray<PointsToNode*> escape_worklist;
1271 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1272 int ptnodes_length = ptnodes_worklist.length();
1273 for (int next = 0; next < ptnodes_length; ++next) {
1274 PointsToNode* ptn = ptnodes_worklist.at(next);
1275 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1276 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1277 escape_worklist.push(ptn);
1278 }
1279 }
1280 // Set escape states to referenced nodes (edges list).
1281 while (escape_worklist.length() > 0) {
1282 PointsToNode* ptn = escape_worklist.pop();
1283 PointsToNode::EscapeState es = ptn->escape_state();
1284 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1285 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1286 es >= PointsToNode::ArgEscape) {
1287 // GlobalEscape or ArgEscape state of field means it has unknown value.
1288 if (add_edge(ptn, phantom_obj)) {
1289 // New edge was added
1290 add_field_uses_to_worklist(ptn->as_Field());
1291 }
1292 }
1293 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1294 PointsToNode* e = i.get();
1295 if (e->is_Arraycopy()) {
1296 assert(ptn->arraycopy_dst(), "sanity");
1297 // Propagate only fields escape state through arraycopy edge.
1298 if (e->fields_escape_state() < field_es) {
1299 set_fields_escape_state(e, field_es);
1300 escape_worklist.push(e);
1301 }
1302 } else if (es >= field_es) {
1303 // fields_escape_state is also set to 'es' if it is less than 'es'.
1304 if (e->escape_state() < es) {
1305 set_escape_state(e, es);
1306 escape_worklist.push(e);
1307 }
1308 } else {
1309 // Propagate field escape state.
1310 bool es_changed = false;
1311 if (e->fields_escape_state() < field_es) {
1312 set_fields_escape_state(e, field_es);
1313 es_changed = true;
1314 }
1315 if ((e->escape_state() < field_es) &&
1316 e->is_Field() && ptn->is_JavaObject() &&
1317 e->as_Field()->is_oop()) {
1318 // Change escape state of referenced fields.
1319 set_escape_state(e, field_es);
1320 es_changed = true;
1321 } else if (e->escape_state() < es) {
1322 set_escape_state(e, es);
1323 es_changed = true;
1324 }
1325 if (es_changed) {
1326 escape_worklist.push(e);
1327 }
1328 }
1329 }
1330 }
1331 // Remove escaped objects from non_escaped list.
1332 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1333 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1334 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1335 non_escaped_worklist.delete_at(next);
1336 }
1337 if (ptn->escape_state() == PointsToNode::NoEscape) {
1338 // Find fields in non-escaped allocations which have unknown value.
1339 find_init_values(ptn, phantom_obj, NULL);
1340 }
1341 }
1342 return (non_escaped_worklist.length() > 0);
1343 }
1344
1345 // Add all references to JavaObject node by walking over all uses.
1346 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1347 int new_edges = 0;
1348 if (populate_worklist) {
1349 // Populate _worklist by uses of jobj's uses.
1350 for (UseIterator i(jobj); i.has_next(); i.next()) {
1351 PointsToNode* use = i.get();
1352 if (use->is_Arraycopy())
1353 continue;
1354 add_uses_to_worklist(use);
1355 if (use->is_Field() && use->as_Field()->is_oop()) {
1356 // Put on worklist all field's uses (loads) and
1357 // related field nodes (same base and offset).
1358 add_field_uses_to_worklist(use->as_Field());
1359 }
1360 }
1361 }
1362 for (int l = 0; l < _worklist.length(); l++) {
1363 PointsToNode* use = _worklist.at(l);
1364 if (PointsToNode::is_base_use(use)) {
1365 // Add reference from jobj to field and from field to jobj (field's base).
1366 use = PointsToNode::get_use_node(use)->as_Field();
1367 if (add_base(use->as_Field(), jobj)) {
1368 new_edges++;
1369 }
1370 continue;
1371 }
1372 assert(!use->is_JavaObject(), "sanity");
1373 if (use->is_Arraycopy()) {
1374 if (jobj == null_obj) // NULL object does not have field edges
1375 continue;
1376 // Added edge from Arraycopy node to arraycopy's source java object
1377 if (add_edge(use, jobj)) {
1378 jobj->set_arraycopy_src();
1379 new_edges++;
1380 }
1381 // and stop here.
1382 continue;
1383 }
1384 if (!add_edge(use, jobj))
1385 continue; // No new edge added, there was such edge already.
1386 new_edges++;
1387 if (use->is_LocalVar()) {
1388 add_uses_to_worklist(use);
1389 if (use->arraycopy_dst()) {
1390 for (EdgeIterator i(use); i.has_next(); i.next()) {
1391 PointsToNode* e = i.get();
1392 if (e->is_Arraycopy()) {
1393 if (jobj == null_obj) // NULL object does not have field edges
1394 continue;
1395 // Add edge from arraycopy's destination java object to Arraycopy node.
1396 if (add_edge(jobj, e)) {
1397 new_edges++;
1398 jobj->set_arraycopy_dst();
1399 }
1400 }
1401 }
1402 }
1403 } else {
1404 // Added new edge to stored in field values.
1405 // Put on worklist all field's uses (loads) and
1406 // related field nodes (same base and offset).
1407 add_field_uses_to_worklist(use->as_Field());
1408 }
1409 }
1410 _worklist.clear();
1411 _in_worklist.Reset();
1412 return new_edges;
1413 }
1414
1415 // Put on worklist all related field nodes.
1416 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1417 assert(field->is_oop(), "sanity");
1418 int offset = field->offset();
1419 add_uses_to_worklist(field);
1420 // Loop over all bases of this field and push on worklist Field nodes
1421 // with the same offset and base (since they may reference the same field).
1422 for (BaseIterator i(field); i.has_next(); i.next()) {
1423 PointsToNode* base = i.get();
1424 add_fields_to_worklist(field, base);
1425 // Check if the base was source object of arraycopy and go over arraycopy's
1426 // destination objects since values stored to a field of source object are
1427 // accessable by uses (loads) of fields of destination objects.
1428 if (base->arraycopy_src()) {
1429 for (UseIterator j(base); j.has_next(); j.next()) {
1430 PointsToNode* arycp = j.get();
1431 if (arycp->is_Arraycopy()) {
1432 for (UseIterator k(arycp); k.has_next(); k.next()) {
1433 PointsToNode* abase = k.get();
1434 if (abase->arraycopy_dst() && abase != base) {
1435 // Look for the same arraycopy reference.
1436 add_fields_to_worklist(field, abase);
1437 }
1438 }
1439 }
1440 }
1441 }
1442 }
1443 }
1444
1445 // Put on worklist all related field nodes.
1446 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1447 int offset = field->offset();
1448 if (base->is_LocalVar()) {
1449 for (UseIterator j(base); j.has_next(); j.next()) {
1450 PointsToNode* f = j.get();
1451 if (PointsToNode::is_base_use(f)) { // Field
1452 f = PointsToNode::get_use_node(f);
1453 if (f == field || !f->as_Field()->is_oop())
1454 continue;
1455 int offs = f->as_Field()->offset();
1456 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1457 add_to_worklist(f);
1458 }
1459 }
1460 }
1461 } else {
1462 assert(base->is_JavaObject(), "sanity");
1463 if (// Skip phantom_object since it is only used to indicate that
1464 // this field's content globally escapes.
1465 (base != phantom_obj) &&
1466 // NULL object node does not have fields.
1467 (base != null_obj)) {
1468 for (EdgeIterator i(base); i.has_next(); i.next()) {
1469 PointsToNode* f = i.get();
1470 // Skip arraycopy edge since store to destination object field
1471 // does not update value in source object field.
1472 if (f->is_Arraycopy()) {
1473 assert(base->arraycopy_dst(), "sanity");
1474 continue;
1475 }
1476 if (f == field || !f->as_Field()->is_oop())
1477 continue;
1478 int offs = f->as_Field()->offset();
1479 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1480 add_to_worklist(f);
1481 }
1482 }
1483 }
1484 }
1485 }
1486
1487 // Find fields which have unknown value.
1488 int ConnectionGraph::find_field_value(FieldNode* field) {
1489 // Escaped fields should have init value already.
1490 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1491 int new_edges = 0;
1492 for (BaseIterator i(field); i.has_next(); i.next()) {
1493 PointsToNode* base = i.get();
1494 if (base->is_JavaObject()) {
1495 // Skip Allocate's fields which will be processed later.
1496 if (base->ideal_node()->is_Allocate())
1497 return 0;
1498 assert(base == null_obj, "only NULL ptr base expected here");
1499 }
1500 }
1501 if (add_edge(field, phantom_obj)) {
1502 // New edge was added
1503 new_edges++;
1504 add_field_uses_to_worklist(field);
1505 }
1506 return new_edges;
1507 }
1508
1509 // Find fields initializing values for allocations.
1510 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1511 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1512 int new_edges = 0;
1513 Node* alloc = pta->ideal_node();
1514 if (init_val == phantom_obj) {
1515 // Do nothing for Allocate nodes since its fields values are
1516 // "known" unless they are initialized by arraycopy/clone.
1517 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1518 return 0;
1519 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1520 #ifdef ASSERT
1521 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1522 const char* name = alloc->as_CallStaticJava()->_name;
1523 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1524 }
1525 #endif
1526 // Non-escaped allocation returned from Java or runtime call have
1527 // unknown values in fields.
1528 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1529 PointsToNode* field = i.get();
1530 if (field->is_Field() && field->as_Field()->is_oop()) {
1531 if (add_edge(field, phantom_obj)) {
1532 // New edge was added
1533 new_edges++;
1534 add_field_uses_to_worklist(field->as_Field());
1535 }
1536 }
1537 }
1538 return new_edges;
1539 }
1540 assert(init_val == null_obj, "sanity");
1541 // Do nothing for Call nodes since its fields values are unknown.
1542 if (!alloc->is_Allocate())
1543 return 0;
1544
1545 InitializeNode* ini = alloc->as_Allocate()->initialization();
1546 bool visited_bottom_offset = false;
1547 GrowableArray<int> offsets_worklist;
1548
1549 // Check if an oop field's initializing value is recorded and add
1550 // a corresponding NULL if field's value if it is not recorded.
1551 // Connection Graph does not record a default initialization by NULL
1552 // captured by Initialize node.
1553 //
1554 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1555 PointsToNode* field = i.get(); // Field (AddP)
1556 if (!field->is_Field() || !field->as_Field()->is_oop())
1557 continue; // Not oop field
1558 int offset = field->as_Field()->offset();
1559 if (offset == Type::OffsetBot) {
1560 if (!visited_bottom_offset) {
1561 // OffsetBot is used to reference array's element,
1562 // always add reference to NULL to all Field nodes since we don't
1563 // known which element is referenced.
1564 if (add_edge(field, null_obj)) {
1565 // New edge was added
1566 new_edges++;
1567 add_field_uses_to_worklist(field->as_Field());
1568 visited_bottom_offset = true;
1569 }
1570 }
1571 } else {
1572 // Check only oop fields.
1573 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1574 if (adr_type->isa_rawptr()) {
1575 #ifdef ASSERT
1576 // Raw pointers are used for initializing stores so skip it
1577 // since it should be recorded already
1578 Node* base = get_addp_base(field->ideal_node());
1579 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1580 (base->in(0) == alloc),"unexpected pointer type");
1581 #endif
1582 continue;
1583 }
1584 if (!offsets_worklist.contains(offset)) {
1585 offsets_worklist.append(offset);
1586 Node* value = NULL;
1587 if (ini != NULL) {
1588 // StoreP::memory_type() == T_ADDRESS
1589 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1590 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1591 // Make sure initializing store has the same type as this AddP.
1592 // This AddP may reference non existing field because it is on a
1593 // dead branch of bimorphic call which is not eliminated yet.
1594 if (store != NULL && store->is_Store() &&
1595 store->as_Store()->memory_type() == ft) {
1596 value = store->in(MemNode::ValueIn);
1597 #ifdef ASSERT
1598 if (VerifyConnectionGraph) {
1599 // Verify that AddP already points to all objects the value points to.
1600 PointsToNode* val = ptnode_adr(value->_idx);
1601 assert((val != NULL), "should be processed already");
1602 PointsToNode* missed_obj = NULL;
1603 if (val->is_JavaObject()) {
1604 if (!field->points_to(val->as_JavaObject())) {
1605 missed_obj = val;
1606 }
1607 } else {
1608 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1609 tty->print_cr("----------init store has invalid value -----");
1610 store->dump();
1611 val->dump();
1612 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1613 }
1614 for (EdgeIterator j(val); j.has_next(); j.next()) {
1615 PointsToNode* obj = j.get();
1616 if (obj->is_JavaObject()) {
1617 if (!field->points_to(obj->as_JavaObject())) {
1618 missed_obj = obj;
1619 break;
1620 }
1621 }
1622 }
1623 }
1624 if (missed_obj != NULL) {
1625 tty->print_cr("----------field---------------------------------");
1626 field->dump();
1627 tty->print_cr("----------missed referernce to object-----------");
1628 missed_obj->dump();
1629 tty->print_cr("----------object referernced by init store -----");
1630 store->dump();
1631 val->dump();
1632 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1633 }
1634 }
1635 #endif
1636 } else {
1637 // There could be initializing stores which follow allocation.
1638 // For example, a volatile field store is not collected
1639 // by Initialize node.
1640 //
1641 // Need to check for dependent loads to separate such stores from
1642 // stores which follow loads. For now, add initial value NULL so
1643 // that compare pointers optimization works correctly.
1644 }
1645 }
1646 if (value == NULL) {
1647 // A field's initializing value was not recorded. Add NULL.
1648 if (add_edge(field, null_obj)) {
1649 // New edge was added
1650 new_edges++;
1651 add_field_uses_to_worklist(field->as_Field());
1652 }
1653 }
1654 }
1655 }
1656 }
1657 return new_edges;
1658 }
1659
1660 // Adjust scalar_replaceable state after Connection Graph is built.
1661 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1662 // Search for non-escaping objects which are not scalar replaceable
1663 // and mark them to propagate the state to referenced objects.
1664
1665 // 1. An object is not scalar replaceable if the field into which it is
1666 // stored has unknown offset (stored into unknown element of an array).
1667 //
1668 for (UseIterator i(jobj); i.has_next(); i.next()) {
1669 PointsToNode* use = i.get();
1670 if (use->is_Arraycopy()) {
1671 continue;
1672 }
1673 if (use->is_Field()) {
1674 FieldNode* field = use->as_Field();
1675 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1676 if (field->offset() == Type::OffsetBot) {
1677 jobj->set_scalar_replaceable(false);
1678 return;
1679 }
1680 // 2. An object is not scalar replaceable if the field into which it is
1681 // stored has multiple bases one of which is null.
1682 if (field->base_count() > 1) {
1683 for (BaseIterator i(field); i.has_next(); i.next()) {
1684 PointsToNode* base = i.get();
1685 if (base == null_obj) {
1686 jobj->set_scalar_replaceable(false);
1687 return;
1688 }
1689 }
1690 }
1691 }
1692 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1693 // 3. An object is not scalar replaceable if it is merged with other objects.
1694 for (EdgeIterator j(use); j.has_next(); j.next()) {
1695 PointsToNode* ptn = j.get();
1696 if (ptn->is_JavaObject() && ptn != jobj) {
1697 // Mark all objects.
1698 jobj->set_scalar_replaceable(false);
1699 ptn->set_scalar_replaceable(false);
1700 }
1701 }
1702 if (!jobj->scalar_replaceable()) {
1703 return;
1704 }
1705 }
1706
1707 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1708 if (j.get()->is_Arraycopy()) {
1709 continue;
1710 }
1711
1712 // Non-escaping object node should point only to field nodes.
1713 FieldNode* field = j.get()->as_Field();
1714 int offset = field->as_Field()->offset();
1715
1716 // 4. An object is not scalar replaceable if it has a field with unknown
1717 // offset (array's element is accessed in loop).
1718 if (offset == Type::OffsetBot) {
1719 jobj->set_scalar_replaceable(false);
1720 return;
1721 }
1722 // 5. Currently an object is not scalar replaceable if a LoadStore node
1723 // access its field since the field value is unknown after it.
1724 //
1725 Node* n = field->ideal_node();
1726 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1727 if (n->fast_out(i)->is_LoadStore()) {
1728 jobj->set_scalar_replaceable(false);
1729 return;
1730 }
1731 }
1732
1733 // 6. Or the address may point to more then one object. This may produce
1734 // the false positive result (set not scalar replaceable)
1735 // since the flow-insensitive escape analysis can't separate
1736 // the case when stores overwrite the field's value from the case
1737 // when stores happened on different control branches.
1738 //
1739 // Note: it will disable scalar replacement in some cases:
1740 //
1741 // Point p[] = new Point[1];
1742 // p[0] = new Point(); // Will be not scalar replaced
1743 //
1744 // but it will save us from incorrect optimizations in next cases:
1745 //
1746 // Point p[] = new Point[1];
1747 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1748 //
1749 if (field->base_count() > 1) {
1750 for (BaseIterator i(field); i.has_next(); i.next()) {
1751 PointsToNode* base = i.get();
1752 // Don't take into account LocalVar nodes which
1753 // may point to only one object which should be also
1754 // this field's base by now.
1755 if (base->is_JavaObject() && base != jobj) {
1756 // Mark all bases.
1757 jobj->set_scalar_replaceable(false);
1758 base->set_scalar_replaceable(false);
1759 }
1760 }
1761 }
1762 }
1763 }
1764
1765 #ifdef ASSERT
1766 void ConnectionGraph::verify_connection_graph(
1767 GrowableArray<PointsToNode*>& ptnodes_worklist,
1768 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1769 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1770 GrowableArray<Node*>& addp_worklist) {
1771 // Verify that graph is complete - no new edges could be added.
1772 int java_objects_length = java_objects_worklist.length();
1773 int non_escaped_length = non_escaped_worklist.length();
1774 int new_edges = 0;
1775 for (int next = 0; next < java_objects_length; ++next) {
1776 JavaObjectNode* ptn = java_objects_worklist.at(next);
1777 new_edges += add_java_object_edges(ptn, true);
1778 }
1779 assert(new_edges == 0, "graph was not complete");
1780 // Verify that escape state is final.
1781 int length = non_escaped_worklist.length();
1782 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1783 assert((non_escaped_length == non_escaped_worklist.length()) &&
1784 (non_escaped_length == length) &&
1785 (_worklist.length() == 0), "escape state was not final");
1786
1787 // Verify fields information.
1788 int addp_length = addp_worklist.length();
1789 for (int next = 0; next < addp_length; ++next ) {
1790 Node* n = addp_worklist.at(next);
1791 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1792 if (field->is_oop()) {
1793 // Verify that field has all bases
1794 Node* base = get_addp_base(n);
1795 PointsToNode* ptn = ptnode_adr(base->_idx);
1796 if (ptn->is_JavaObject()) {
1797 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1798 } else {
1799 assert(ptn->is_LocalVar(), "sanity");
1800 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1801 PointsToNode* e = i.get();
1802 if (e->is_JavaObject()) {
1803 assert(field->has_base(e->as_JavaObject()), "sanity");
1804 }
1805 }
1806 }
1807 // Verify that all fields have initializing values.
1808 if (field->edge_count() == 0) {
1809 tty->print_cr("----------field does not have references----------");
1810 field->dump();
1811 for (BaseIterator i(field); i.has_next(); i.next()) {
1812 PointsToNode* base = i.get();
1813 tty->print_cr("----------field has next base---------------------");
1814 base->dump();
1815 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1816 tty->print_cr("----------base has fields-------------------------");
1817 for (EdgeIterator j(base); j.has_next(); j.next()) {
1818 j.get()->dump();
1819 }
1820 tty->print_cr("----------base has references---------------------");
1821 for (UseIterator j(base); j.has_next(); j.next()) {
1822 j.get()->dump();
1823 }
1824 }
1825 }
1826 for (UseIterator i(field); i.has_next(); i.next()) {
1827 i.get()->dump();
1828 }
1829 assert(field->edge_count() > 0, "sanity");
1830 }
1831 }
1832 }
1833 }
1834 #endif
1835
1836 // Optimize ideal graph.
1837 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1838 GrowableArray<Node*>& storestore_worklist) {
1839 Compile* C = _compile;
1840 PhaseIterGVN* igvn = _igvn;
1841 if (EliminateLocks) {
1842 // Mark locks before changing ideal graph.
1843 int cnt = C->macro_count();
1844 for( int i=0; i < cnt; i++ ) {
1845 Node *n = C->macro_node(i);
1846 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1847 AbstractLockNode* alock = n->as_AbstractLock();
1848 if (!alock->is_non_esc_obj()) {
1849 if (not_global_escape(alock->obj_node())) {
1850 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1851 // The lock could be marked eliminated by lock coarsening
1852 // code during first IGVN before EA. Replace coarsened flag
1853 // to eliminate all associated locks/unlocks.
1854 #ifdef ASSERT
1855 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1856 #endif
1857 alock->set_non_esc_obj();
1858 }
1859 }
1860 }
1861 }
1862 }
1863
1864 if (OptimizePtrCompare) {
1865 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1866 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1867 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1868 // Optimize objects compare.
1869 while (ptr_cmp_worklist.length() != 0) {
1870 Node *n = ptr_cmp_worklist.pop();
1871 Node *res = optimize_ptr_compare(n);
1872 if (res != NULL) {
1873 #ifndef PRODUCT
1874 if (PrintOptimizePtrCompare) {
1875 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"));
1876 if (Verbose) {
1877 n->dump(1);
1878 }
1879 }
1880 #endif
1881 igvn->replace_node(n, res);
1882 }
1883 }
1884 // cleanup
1885 if (_pcmp_neq->outcnt() == 0)
1886 igvn->hash_delete(_pcmp_neq);
1887 if (_pcmp_eq->outcnt() == 0)
1888 igvn->hash_delete(_pcmp_eq);
1889 }
1890
1891 // For MemBarStoreStore nodes added in library_call.cpp, check
1892 // escape status of associated AllocateNode and optimize out
1893 // MemBarStoreStore node if the allocated object never escapes.
1894 while (storestore_worklist.length() != 0) {
1895 Node *n = storestore_worklist.pop();
1896 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1897 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1898 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1899 if (not_global_escape(alloc)) {
1900 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1901 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1902 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1903 igvn->register_new_node_with_optimizer(mb);
1904 igvn->replace_node(storestore, mb);
1905 }
1906 }
1907 }
1908
1909 // Optimize objects compare.
1910 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1911 assert(OptimizePtrCompare, "sanity");
1912 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1913 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1914 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1915 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1916 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1917 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1918
1919 // Check simple cases first.
1920 if (jobj1 != NULL) {
1921 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1922 if (jobj1 == jobj2) {
1923 // Comparing the same not escaping object.
1924 return _pcmp_eq;
1925 }
1926 Node* obj = jobj1->ideal_node();
1927 // Comparing not escaping allocation.
1928 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1929 !ptn2->points_to(jobj1)) {
1930 return _pcmp_neq; // This includes nullness check.
1931 }
1932 }
1933 }
1934 if (jobj2 != NULL) {
1935 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1936 Node* obj = jobj2->ideal_node();
1937 // Comparing not escaping allocation.
1938 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1939 !ptn1->points_to(jobj2)) {
1940 return _pcmp_neq; // This includes nullness check.
1941 }
1942 }
1943 }
1944 if (jobj1 != NULL && jobj1 != phantom_obj &&
1945 jobj2 != NULL && jobj2 != phantom_obj &&
1946 jobj1->ideal_node()->is_Con() &&
1947 jobj2->ideal_node()->is_Con()) {
1948 // Klass or String constants compare. Need to be careful with
1949 // compressed pointers - compare types of ConN and ConP instead of nodes.
1950 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1951 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1952 if (t1->make_ptr() == t2->make_ptr()) {
1953 return _pcmp_eq;
1954 } else {
1955 return _pcmp_neq;
1956 }
1957 }
1958 if (ptn1->meet(ptn2)) {
1959 return NULL; // Sets are not disjoint
1960 }
1961
1962 // Sets are disjoint.
1963 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1964 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1965 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1966 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1967 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1968 set2_has_unknown_ptr && set1_has_null_ptr) {
1969 // Check nullness of unknown object.
1970 return NULL;
1971 }
1972
1973 // Disjointness by itself is not sufficient since
1974 // alias analysis is not complete for escaped objects.
1975 // Disjoint sets are definitely unrelated only when
1976 // at least one set has only not escaping allocations.
1977 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1978 if (ptn1->non_escaping_allocation()) {
1979 return _pcmp_neq;
1980 }
1981 }
1982 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1983 if (ptn2->non_escaping_allocation()) {
1984 return _pcmp_neq;
1985 }
1986 }
1987 return NULL;
1988 }
1989
1990 // Connection Graph constuction functions.
1991
1992 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1993 PointsToNode* ptadr = _nodes.at(n->_idx);
1994 if (ptadr != NULL) {
1995 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1996 return;
1997 }
1998 Compile* C = _compile;
1999 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2000 _nodes.at_put(n->_idx, ptadr);
2001 }
2002
2003 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2004 PointsToNode* ptadr = _nodes.at(n->_idx);
2005 if (ptadr != NULL) {
2006 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2007 return;
2008 }
2009 Compile* C = _compile;
2010 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2011 _nodes.at_put(n->_idx, ptadr);
2012 }
2013
2014 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2015 PointsToNode* ptadr = _nodes.at(n->_idx);
2016 if (ptadr != NULL) {
2017 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2018 return;
2019 }
2020 bool unsafe = false;
2021 bool is_oop = is_oop_field(n, offset, &unsafe);
2022 if (unsafe) {
2023 es = PointsToNode::GlobalEscape;
2024 }
2025 Compile* C = _compile;
2026 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2027 _nodes.at_put(n->_idx, field);
2028 }
2029
2030 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2031 PointsToNode* src, PointsToNode* dst) {
2032 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2033 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2034 PointsToNode* ptadr = _nodes.at(n->_idx);
2035 if (ptadr != NULL) {
2036 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2037 return;
2038 }
2039 Compile* C = _compile;
2040 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2041 _nodes.at_put(n->_idx, ptadr);
2042 // Add edge from arraycopy node to source object.
2043 (void)add_edge(ptadr, src);
2044 src->set_arraycopy_src();
2045 // Add edge from destination object to arraycopy node.
2046 (void)add_edge(dst, ptadr);
2047 dst->set_arraycopy_dst();
2048 }
2049
2050 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2051 const Type* adr_type = n->as_AddP()->bottom_type();
2052 BasicType bt = T_INT;
2053 if (offset == Type::OffsetBot) {
2054 // Check only oop fields.
2055 if (!adr_type->isa_aryptr() ||
2056 (adr_type->isa_aryptr()->klass() == NULL) ||
2057 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2058 // OffsetBot is used to reference array's element. Ignore first AddP.
2059 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2060 bt = T_OBJECT;
2061 }
2062 }
2063 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2064 if (adr_type->isa_instptr()) {
2065 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2066 if (field != NULL) {
2067 bt = field->layout_type();
2068 } else {
2069 // Check for unsafe oop field access
2070 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2071 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2072 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2073 bt = T_OBJECT;
2074 (*unsafe) = true;
2075 }
2076 }
2077 } else if (adr_type->isa_aryptr()) {
2078 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2079 // Ignore array length load.
2080 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2081 // Ignore first AddP.
2082 } else {
2083 const Type* elemtype = adr_type->isa_aryptr()->elem();
2084 bt = elemtype->array_element_basic_type();
2085 }
2086 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2087 // Allocation initialization, ThreadLocal field access, unsafe access
2088 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2089 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2090 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2091 bt = T_OBJECT;
2092 }
2093 }
2094 }
2095 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2096 }
2097
2098 // Returns unique pointed java object or NULL.
2099 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2100 assert(!_collecting, "should not call when contructed graph");
2101 // If the node was created after the escape computation we can't answer.
2102 uint idx = n->_idx;
2103 if (idx >= nodes_size()) {
2104 return NULL;
2105 }
2106 PointsToNode* ptn = ptnode_adr(idx);
2107 if (ptn->is_JavaObject()) {
2108 return ptn->as_JavaObject();
2109 }
2110 assert(ptn->is_LocalVar(), "sanity");
2111 // Check all java objects it points to.
2112 JavaObjectNode* jobj = NULL;
2113 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2114 PointsToNode* e = i.get();
2115 if (e->is_JavaObject()) {
2116 if (jobj == NULL) {
2117 jobj = e->as_JavaObject();
2118 } else if (jobj != e) {
2119 return NULL;
2120 }
2121 }
2122 }
2123 return jobj;
2124 }
2125
2126 // Return true if this node points only to non-escaping allocations.
2127 bool PointsToNode::non_escaping_allocation() {
2128 if (is_JavaObject()) {
2129 Node* n = ideal_node();
2130 if (n->is_Allocate() || n->is_CallStaticJava()) {
2131 return (escape_state() == PointsToNode::NoEscape);
2132 } else {
2133 return false;
2134 }
2135 }
2136 assert(is_LocalVar(), "sanity");
2137 // Check all java objects it points to.
2138 for (EdgeIterator i(this); i.has_next(); i.next()) {
2139 PointsToNode* e = i.get();
2140 if (e->is_JavaObject()) {
2141 Node* n = e->ideal_node();
2142 if ((e->escape_state() != PointsToNode::NoEscape) ||
2143 !(n->is_Allocate() || n->is_CallStaticJava())) {
2144 return false;
2145 }
2146 }
2147 }
2148 return true;
2149 }
2150
2151 // Return true if we know the node does not escape globally.
2152 bool ConnectionGraph::not_global_escape(Node *n) {
2153 assert(!_collecting, "should not call during graph construction");
2154 // If the node was created after the escape computation we can't answer.
2155 uint idx = n->_idx;
2156 if (idx >= nodes_size()) {
2157 return false;
2158 }
2159 PointsToNode* ptn = ptnode_adr(idx);
2160 PointsToNode::EscapeState es = ptn->escape_state();
2161 // If we have already computed a value, return it.
2162 if (es >= PointsToNode::GlobalEscape)
2163 return false;
2164 if (ptn->is_JavaObject()) {
2165 return true; // (es < PointsToNode::GlobalEscape);
2166 }
2167 assert(ptn->is_LocalVar(), "sanity");
2168 // Check all java objects it points to.
2169 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2170 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2171 return false;
2172 }
2173 return true;
2174 }
2175
2176
2177 // Helper functions
2178
2179 // Return true if this node points to specified node or nodes it points to.
2180 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2181 if (is_JavaObject()) {
2182 return (this == ptn);
2183 }
2184 assert(is_LocalVar() || is_Field(), "sanity");
2185 for (EdgeIterator i(this); i.has_next(); i.next()) {
2186 if (i.get() == ptn)
2187 return true;
2188 }
2189 return false;
2190 }
2191
2192 // Return true if one node points to an other.
2193 bool PointsToNode::meet(PointsToNode* ptn) {
2194 if (this == ptn) {
2195 return true;
2196 } else if (ptn->is_JavaObject()) {
2197 return this->points_to(ptn->as_JavaObject());
2198 } else if (this->is_JavaObject()) {
2199 return ptn->points_to(this->as_JavaObject());
2200 }
2201 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2202 int ptn_count = ptn->edge_count();
2203 for (EdgeIterator i(this); i.has_next(); i.next()) {
2204 PointsToNode* this_e = i.get();
2205 for (int j = 0; j < ptn_count; j++) {
2206 if (this_e == ptn->edge(j))
2207 return true;
2208 }
2209 }
2210 return false;
2211 }
2212
2213 #ifdef ASSERT
2214 // Return true if bases point to this java object.
2215 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2216 for (BaseIterator i(this); i.has_next(); i.next()) {
2217 if (i.get() == jobj)
2218 return true;
2219 }
2220 return false;
2221 }
2222 #endif
2223
2224 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2225 const Type *adr_type = phase->type(adr);
2226 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2227 adr->in(AddPNode::Address)->is_Proj() &&
2228 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2229 // We are computing a raw address for a store captured by an Initialize
2230 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2231 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2232 assert(offs != Type::OffsetBot ||
2233 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2234 "offset must be a constant or it is initialization of array");
2235 return offs;
2236 }
2237 const TypePtr *t_ptr = adr_type->isa_ptr();
2238 assert(t_ptr != NULL, "must be a pointer type");
2239 return t_ptr->offset();
2240 }
2241
2242 Node* ConnectionGraph::get_addp_base(Node *addp) {
2243 assert(addp->is_AddP(), "must be AddP");
2244 //
2245 // AddP cases for Base and Address inputs:
2246 // case #1. Direct object's field reference:
2247 // Allocate
2248 // |
2249 // Proj #5 ( oop result )
2250 // |
2251 // CheckCastPP (cast to instance type)
2252 // | |
2253 // AddP ( base == address )
2254 //
2255 // case #2. Indirect object's field reference:
2256 // Phi
2257 // |
2258 // CastPP (cast to instance type)
2259 // | |
2260 // AddP ( base == address )
2261 //
2262 // case #3. Raw object's field reference for Initialize node:
2263 // Allocate
2264 // |
2265 // Proj #5 ( oop result )
2266 // top |
2267 // \ |
2268 // AddP ( base == top )
2269 //
2270 // case #4. Array's element reference:
2271 // {CheckCastPP | CastPP}
2272 // | | |
2273 // | AddP ( array's element offset )
2274 // | |
2275 // AddP ( array's offset )
2276 //
2277 // case #5. Raw object's field reference for arraycopy stub call:
2278 // The inline_native_clone() case when the arraycopy stub is called
2279 // after the allocation before Initialize and CheckCastPP nodes.
2280 // Allocate
2281 // |
2282 // Proj #5 ( oop result )
2283 // | |
2284 // AddP ( base == address )
2285 //
2286 // case #6. Constant Pool, ThreadLocal, CastX2P or
2287 // Raw object's field reference:
2288 // {ConP, ThreadLocal, CastX2P, raw Load}
2289 // top |
2290 // \ |
2291 // AddP ( base == top )
2292 //
2293 // case #7. Klass's field reference.
2294 // LoadKlass
2295 // | |
2296 // AddP ( base == address )
2297 //
2298 // case #8. narrow Klass's field reference.
2299 // LoadNKlass
2300 // |
2301 // DecodeN
2302 // | |
2303 // AddP ( base == address )
2304 //
2305 Node *base = addp->in(AddPNode::Base);
2306 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2307 base = addp->in(AddPNode::Address);
2308 while (base->is_AddP()) {
2309 // Case #6 (unsafe access) may have several chained AddP nodes.
2310 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2311 base = base->in(AddPNode::Address);
2312 }
2313 Node* uncast_base = base->uncast();
2314 int opcode = uncast_base->Opcode();
2315 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2316 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2317 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2318 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2319 }
2320 return base;
2321 }
2322
2323 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2324 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2325 Node* addp2 = addp->raw_out(0);
2326 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2327 addp2->in(AddPNode::Base) == n &&
2328 addp2->in(AddPNode::Address) == addp) {
2329 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2330 //
2331 // Find array's offset to push it on worklist first and
2332 // as result process an array's element offset first (pushed second)
2333 // to avoid CastPP for the array's offset.
2334 // Otherwise the inserted CastPP (LocalVar) will point to what
2335 // the AddP (Field) points to. Which would be wrong since
2336 // the algorithm expects the CastPP has the same point as
2337 // as AddP's base CheckCastPP (LocalVar).
2338 //
2339 // ArrayAllocation
2340 // |
2341 // CheckCastPP
2342 // |
2343 // memProj (from ArrayAllocation CheckCastPP)
2344 // | ||
2345 // | || Int (element index)
2346 // | || | ConI (log(element size))
2347 // | || | /
2348 // | || LShift
2349 // | || /
2350 // | AddP (array's element offset)
2351 // | |
2352 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2353 // | / /
2354 // AddP (array's offset)
2355 // |
2356 // Load/Store (memory operation on array's element)
2357 //
2358 return addp2;
2359 }
2360 return NULL;
2361 }
2362
2363 //
2364 // Adjust the type and inputs of an AddP which computes the
2365 // address of a field of an instance
2366 //
2367 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2368 PhaseGVN* igvn = _igvn;
2369 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2370 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2371 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2372 if (t == NULL) {
2373 // We are computing a raw address for a store captured by an Initialize
2374 // compute an appropriate address type (cases #3 and #5).
2375 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2376 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2377 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2378 assert(offs != Type::OffsetBot, "offset must be a constant");
2379 t = base_t->add_offset(offs)->is_oopptr();
2380 }
2381 int inst_id = base_t->instance_id();
2382 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2383 "old type must be non-instance or match new type");
2384
2385 // The type 't' could be subclass of 'base_t'.
2386 // As result t->offset() could be large then base_t's size and it will
2387 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2388 // constructor verifies correctness of the offset.
2389 //
2390 // It could happened on subclass's branch (from the type profiling
2391 // inlining) which was not eliminated during parsing since the exactness
2392 // of the allocation type was not propagated to the subclass type check.
2393 //
2394 // Or the type 't' could be not related to 'base_t' at all.
2395 // It could happened when CHA type is different from MDO type on a dead path
2396 // (for example, from instanceof check) which is not collapsed during parsing.
2397 //
2398 // Do nothing for such AddP node and don't process its users since
2399 // this code branch will go away.
2400 //
2401 if (!t->is_known_instance() &&
2402 !base_t->klass()->is_subtype_of(t->klass())) {
2403 return false; // bail out
2404 }
2405 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2406 // Do NOT remove the next line: ensure a new alias index is allocated
2407 // for the instance type. Note: C++ will not remove it since the call
2408 // has side effect.
2409 int alias_idx = _compile->get_alias_index(tinst);
2410 igvn->set_type(addp, tinst);
2411 // record the allocation in the node map
2412 set_map(addp, get_map(base->_idx));
2413 // Set addp's Base and Address to 'base'.
2414 Node *abase = addp->in(AddPNode::Base);
2415 Node *adr = addp->in(AddPNode::Address);
2416 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2417 adr->in(0)->_idx == (uint)inst_id) {
2418 // Skip AddP cases #3 and #5.
2419 } else {
2420 assert(!abase->is_top(), "sanity"); // AddP case #3
2421 if (abase != base) {
2422 igvn->hash_delete(addp);
2423 addp->set_req(AddPNode::Base, base);
2424 if (abase == adr) {
2425 addp->set_req(AddPNode::Address, base);
2426 } else {
2427 // AddP case #4 (adr is array's element offset AddP node)
2428 #ifdef ASSERT
2429 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2430 assert(adr->is_AddP() && atype != NULL &&
2431 atype->instance_id() == inst_id, "array's element offset should be processed first");
2432 #endif
2433 }
2434 igvn->hash_insert(addp);
2435 }
2436 }
2437 // Put on IGVN worklist since at least addp's type was changed above.
2438 record_for_optimizer(addp);
2439 return true;
2440 }
2441
2442 //
2443 // Create a new version of orig_phi if necessary. Returns either the newly
2444 // created phi or an existing phi. Sets create_new to indicate whether a new
2445 // phi was created. Cache the last newly created phi in the node map.
2446 //
2447 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2448 Compile *C = _compile;
2449 PhaseGVN* igvn = _igvn;
2450 new_created = false;
2451 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2452 // nothing to do if orig_phi is bottom memory or matches alias_idx
2453 if (phi_alias_idx == alias_idx) {
2454 return orig_phi;
2455 }
2456 // Have we recently created a Phi for this alias index?
2457 PhiNode *result = get_map_phi(orig_phi->_idx);
2458 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2459 return result;
2460 }
2461 // Previous check may fail when the same wide memory Phi was split into Phis
2462 // for different memory slices. Search all Phis for this region.
2463 if (result != NULL) {
2464 Node* region = orig_phi->in(0);
2465 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2466 Node* phi = region->fast_out(i);
2467 if (phi->is_Phi() &&
2468 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2469 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2470 return phi->as_Phi();
2471 }
2472 }
2473 }
2474 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2475 if (C->do_escape_analysis() == true && !C->failing()) {
2476 // Retry compilation without escape analysis.
2477 // If this is the first failure, the sentinel string will "stick"
2478 // to the Compile object, and the C2Compiler will see it and retry.
2479 C->record_failure(C2Compiler::retry_no_escape_analysis());
2480 }
2481 return NULL;
2482 }
2483 orig_phi_worklist.append_if_missing(orig_phi);
2484 const TypePtr *atype = C->get_adr_type(alias_idx);
2485 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2486 C->copy_node_notes_to(result, orig_phi);
2487 igvn->set_type(result, result->bottom_type());
2488 record_for_optimizer(result);
2489 set_map(orig_phi, result);
2490 new_created = true;
2491 return result;
2492 }
2493
2494 //
2495 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2496 // specified alias index.
2497 //
2498 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2499 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2500 Compile *C = _compile;
2501 PhaseGVN* igvn = _igvn;
2502 bool new_phi_created;
2503 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2504 if (!new_phi_created) {
2505 return result;
2506 }
2507 GrowableArray<PhiNode *> phi_list;
2508 GrowableArray<uint> cur_input;
2509 PhiNode *phi = orig_phi;
2510 uint idx = 1;
2511 bool finished = false;
2512 while(!finished) {
2513 while (idx < phi->req()) {
2514 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2515 if (mem != NULL && mem->is_Phi()) {
2516 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2517 if (new_phi_created) {
2518 // found an phi for which we created a new split, push current one on worklist and begin
2519 // processing new one
2520 phi_list.push(phi);
2521 cur_input.push(idx);
2522 phi = mem->as_Phi();
2523 result = newphi;
2524 idx = 1;
2525 continue;
2526 } else {
2527 mem = newphi;
2528 }
2529 }
2530 if (C->failing()) {
2531 return NULL;
2532 }
2533 result->set_req(idx++, mem);
2534 }
2535 #ifdef ASSERT
2536 // verify that the new Phi has an input for each input of the original
2537 assert( phi->req() == result->req(), "must have same number of inputs.");
2538 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2539 #endif
2540 // Check if all new phi's inputs have specified alias index.
2541 // Otherwise use old phi.
2542 for (uint i = 1; i < phi->req(); i++) {
2543 Node* in = result->in(i);
2544 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2545 }
2546 // we have finished processing a Phi, see if there are any more to do
2547 finished = (phi_list.length() == 0 );
2548 if (!finished) {
2549 phi = phi_list.pop();
2550 idx = cur_input.pop();
2551 PhiNode *prev_result = get_map_phi(phi->_idx);
2552 prev_result->set_req(idx++, result);
2553 result = prev_result;
2554 }
2555 }
2556 return result;
2557 }
2558
2559 //
2560 // The next methods are derived from methods in MemNode.
2561 //
2562 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2563 Node *mem = mmem;
2564 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2565 // means an array I have not precisely typed yet. Do not do any
2566 // alias stuff with it any time soon.
2567 if (toop->base() != Type::AnyPtr &&
2568 !(toop->klass() != NULL &&
2569 toop->klass()->is_java_lang_Object() &&
2570 toop->offset() == Type::OffsetBot)) {
2571 mem = mmem->memory_at(alias_idx);
2572 // Update input if it is progress over what we have now
2573 }
2574 return mem;
2575 }
2576
2577 //
2578 // Move memory users to their memory slices.
2579 //
2580 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2581 Compile* C = _compile;
2582 PhaseGVN* igvn = _igvn;
2583 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2584 assert(tp != NULL, "ptr type");
2585 int alias_idx = C->get_alias_index(tp);
2586 int general_idx = C->get_general_index(alias_idx);
2587
2588 // Move users first
2589 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2590 Node* use = n->fast_out(i);
2591 if (use->is_MergeMem()) {
2592 MergeMemNode* mmem = use->as_MergeMem();
2593 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2594 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2595 continue; // Nothing to do
2596 }
2597 // Replace previous general reference to mem node.
2598 uint orig_uniq = C->unique();
2599 Node* m = find_inst_mem(n, general_idx, orig_phis);
2600 assert(orig_uniq == C->unique(), "no new nodes");
2601 mmem->set_memory_at(general_idx, m);
2602 --imax;
2603 --i;
2604 } else if (use->is_MemBar()) {
2605 assert(!use->is_Initialize(), "initializing stores should not be moved");
2606 if (use->req() > MemBarNode::Precedent &&
2607 use->in(MemBarNode::Precedent) == n) {
2608 // Don't move related membars.
2609 record_for_optimizer(use);
2610 continue;
2611 }
2612 tp = use->as_MemBar()->adr_type()->isa_ptr();
2613 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2614 alias_idx == general_idx) {
2615 continue; // Nothing to do
2616 }
2617 // Move to general memory slice.
2618 uint orig_uniq = C->unique();
2619 Node* m = find_inst_mem(n, general_idx, orig_phis);
2620 assert(orig_uniq == C->unique(), "no new nodes");
2621 igvn->hash_delete(use);
2622 imax -= use->replace_edge(n, m);
2623 igvn->hash_insert(use);
2624 record_for_optimizer(use);
2625 --i;
2626 #ifdef ASSERT
2627 } else if (use->is_Mem()) {
2628 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2629 // Don't move related cardmark.
2630 continue;
2631 }
2632 // Memory nodes should have new memory input.
2633 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2634 assert(tp != NULL, "ptr type");
2635 int idx = C->get_alias_index(tp);
2636 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2637 "Following memory nodes should have new memory input or be on the same memory slice");
2638 } else if (use->is_Phi()) {
2639 // Phi nodes should be split and moved already.
2640 tp = use->as_Phi()->adr_type()->isa_ptr();
2641 assert(tp != NULL, "ptr type");
2642 int idx = C->get_alias_index(tp);
2643 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2644 } else {
2645 use->dump();
2646 assert(false, "should not be here");
2647 #endif
2648 }
2649 }
2650 }
2651
2652 //
2653 // Search memory chain of "mem" to find a MemNode whose address
2654 // is the specified alias index.
2655 //
2656 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2657 if (orig_mem == NULL)
2658 return orig_mem;
2659 Compile* C = _compile;
2660 PhaseGVN* igvn = _igvn;
2661 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2662 bool is_instance = (toop != NULL) && toop->is_known_instance();
2663 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2664 Node *prev = NULL;
2665 Node *result = orig_mem;
2666 while (prev != result) {
2667 prev = result;
2668 if (result == start_mem)
2669 break; // hit one of our sentinels
2670 if (result->is_Mem()) {
2671 const Type *at = igvn->type(result->in(MemNode::Address));
2672 if (at == Type::TOP)
2673 break; // Dead
2674 assert (at->isa_ptr() != NULL, "pointer type required.");
2675 int idx = C->get_alias_index(at->is_ptr());
2676 if (idx == alias_idx)
2677 break; // Found
2678 if (!is_instance && (at->isa_oopptr() == NULL ||
2679 !at->is_oopptr()->is_known_instance())) {
2680 break; // Do not skip store to general memory slice.
2681 }
2682 result = result->in(MemNode::Memory);
2683 }
2684 if (!is_instance)
2685 continue; // don't search further for non-instance types
2686 // skip over a call which does not affect this memory slice
2687 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2688 Node *proj_in = result->in(0);
2689 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2690 break; // hit one of our sentinels
2691 } else if (proj_in->is_Call()) {
2692 // ArrayCopy node processed here as well
2693 CallNode *call = proj_in->as_Call();
2694 if (!call->may_modify(toop, igvn)) {
2695 result = call->in(TypeFunc::Memory);
2696 }
2697 } else if (proj_in->is_Initialize()) {
2698 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2699 // Stop if this is the initialization for the object instance which
2700 // which contains this memory slice, otherwise skip over it.
2701 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2702 result = proj_in->in(TypeFunc::Memory);
2703 }
2704 } else if (proj_in->is_MemBar()) {
2705 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2706 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2707 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2708 // clone
2709 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2710 if (ac->may_modify(toop, igvn)) {
2711 break;
2712 }
2713 }
2714 result = proj_in->in(TypeFunc::Memory);
2715 }
2716 } else if (result->is_MergeMem()) {
2717 MergeMemNode *mmem = result->as_MergeMem();
2718 result = step_through_mergemem(mmem, alias_idx, toop);
2719 if (result == mmem->base_memory()) {
2720 // Didn't find instance memory, search through general slice recursively.
2721 result = mmem->memory_at(C->get_general_index(alias_idx));
2722 result = find_inst_mem(result, alias_idx, orig_phis);
2723 if (C->failing()) {
2724 return NULL;
2725 }
2726 mmem->set_memory_at(alias_idx, result);
2727 }
2728 } else if (result->is_Phi() &&
2729 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2730 Node *un = result->as_Phi()->unique_input(igvn);
2731 if (un != NULL) {
2732 orig_phis.append_if_missing(result->as_Phi());
2733 result = un;
2734 } else {
2735 break;
2736 }
2737 } else if (result->is_ClearArray()) {
2738 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2739 // Can not bypass initialization of the instance
2740 // we are looking for.
2741 break;
2742 }
2743 // Otherwise skip it (the call updated 'result' value).
2744 } else if (result->Opcode() == Op_SCMemProj) {
2745 Node* mem = result->in(0);
2746 Node* adr = NULL;
2747 if (mem->is_LoadStore()) {
2748 adr = mem->in(MemNode::Address);
2749 } else {
2750 assert(mem->Opcode() == Op_EncodeISOArray ||
2751 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2752 adr = mem->in(3); // Memory edge corresponds to destination array
2753 }
2754 const Type *at = igvn->type(adr);
2755 if (at != Type::TOP) {
2756 assert(at->isa_ptr() != NULL, "pointer type required.");
2757 int idx = C->get_alias_index(at->is_ptr());
2758 if (idx == alias_idx) {
2759 // Assert in debug mode
2760 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2761 break; // In product mode return SCMemProj node
2762 }
2763 }
2764 result = mem->in(MemNode::Memory);
2765 } else if (result->Opcode() == Op_StrInflatedCopy) {
2766 Node* adr = result->in(3); // Memory edge corresponds to destination array
2767 const Type *at = igvn->type(adr);
2768 if (at != Type::TOP) {
2769 assert(at->isa_ptr() != NULL, "pointer type required.");
2770 int idx = C->get_alias_index(at->is_ptr());
2771 if (idx == alias_idx) {
2772 // Assert in debug mode
2773 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2774 break; // In product mode return SCMemProj node
2775 }
2776 }
2777 result = result->in(MemNode::Memory);
2778 }
2779 }
2780 if (result->is_Phi()) {
2781 PhiNode *mphi = result->as_Phi();
2782 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2783 const TypePtr *t = mphi->adr_type();
2784 if (!is_instance) {
2785 // Push all non-instance Phis on the orig_phis worklist to update inputs
2786 // during Phase 4 if needed.
2787 orig_phis.append_if_missing(mphi);
2788 } else if (C->get_alias_index(t) != alias_idx) {
2789 // Create a new Phi with the specified alias index type.
2790 result = split_memory_phi(mphi, alias_idx, orig_phis);
2791 }
2792 }
2793 // the result is either MemNode, PhiNode, InitializeNode.
2794 return result;
2795 }
2796
2797 //
2798 // Convert the types of unescaped object to instance types where possible,
2799 // propagate the new type information through the graph, and update memory
2800 // edges and MergeMem inputs to reflect the new type.
2801 //
2802 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2803 // The processing is done in 4 phases:
2804 //
2805 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2806 // types for the CheckCastPP for allocations where possible.
2807 // Propagate the new types through users as follows:
2808 // casts and Phi: push users on alloc_worklist
2809 // AddP: cast Base and Address inputs to the instance type
2810 // push any AddP users on alloc_worklist and push any memnode
2811 // users onto memnode_worklist.
2812 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2813 // search the Memory chain for a store with the appropriate type
2814 // address type. If a Phi is found, create a new version with
2815 // the appropriate memory slices from each of the Phi inputs.
2816 // For stores, process the users as follows:
2817 // MemNode: push on memnode_worklist
2818 // MergeMem: push on mergemem_worklist
2819 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2820 // moving the first node encountered of each instance type to the
2821 // the input corresponding to its alias index.
2822 // appropriate memory slice.
2823 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2824 //
2825 // In the following example, the CheckCastPP nodes are the cast of allocation
2826 // results and the allocation of node 29 is unescaped and eligible to be an
2827 // instance type.
2828 //
2829 // We start with:
2830 //
2831 // 7 Parm #memory
2832 // 10 ConI "12"
2833 // 19 CheckCastPP "Foo"
2834 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2835 // 29 CheckCastPP "Foo"
2836 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2837 //
2838 // 40 StoreP 25 7 20 ... alias_index=4
2839 // 50 StoreP 35 40 30 ... alias_index=4
2840 // 60 StoreP 45 50 20 ... alias_index=4
2841 // 70 LoadP _ 60 30 ... alias_index=4
2842 // 80 Phi 75 50 60 Memory alias_index=4
2843 // 90 LoadP _ 80 30 ... alias_index=4
2844 // 100 LoadP _ 80 20 ... alias_index=4
2845 //
2846 //
2847 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2848 // and creating a new alias index for node 30. This gives:
2849 //
2850 // 7 Parm #memory
2851 // 10 ConI "12"
2852 // 19 CheckCastPP "Foo"
2853 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2854 // 29 CheckCastPP "Foo" iid=24
2855 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2856 //
2857 // 40 StoreP 25 7 20 ... alias_index=4
2858 // 50 StoreP 35 40 30 ... alias_index=6
2859 // 60 StoreP 45 50 20 ... alias_index=4
2860 // 70 LoadP _ 60 30 ... alias_index=6
2861 // 80 Phi 75 50 60 Memory alias_index=4
2862 // 90 LoadP _ 80 30 ... alias_index=6
2863 // 100 LoadP _ 80 20 ... alias_index=4
2864 //
2865 // In phase 2, new memory inputs are computed for the loads and stores,
2866 // And a new version of the phi is created. In phase 4, the inputs to
2867 // node 80 are updated and then the memory nodes are updated with the
2868 // values computed in phase 2. This results in:
2869 //
2870 // 7 Parm #memory
2871 // 10 ConI "12"
2872 // 19 CheckCastPP "Foo"
2873 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2874 // 29 CheckCastPP "Foo" iid=24
2875 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2876 //
2877 // 40 StoreP 25 7 20 ... alias_index=4
2878 // 50 StoreP 35 7 30 ... alias_index=6
2879 // 60 StoreP 45 40 20 ... alias_index=4
2880 // 70 LoadP _ 50 30 ... alias_index=6
2881 // 80 Phi 75 40 60 Memory alias_index=4
2882 // 120 Phi 75 50 50 Memory alias_index=6
2883 // 90 LoadP _ 120 30 ... alias_index=6
2884 // 100 LoadP _ 80 20 ... alias_index=4
2885 //
2886 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2887 GrowableArray<Node *> memnode_worklist;
2888 GrowableArray<PhiNode *> orig_phis;
2889 PhaseIterGVN *igvn = _igvn;
2890 uint new_index_start = (uint) _compile->num_alias_types();
2891 Arena* arena = Thread::current()->resource_area();
2892 VectorSet visited(arena);
2893 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2894 uint unique_old = _compile->unique();
2895
2896 // Phase 1: Process possible allocations from alloc_worklist.
2897 // Create instance types for the CheckCastPP for allocations where possible.
2898 //
2899 // (Note: don't forget to change the order of the second AddP node on
2900 // the alloc_worklist if the order of the worklist processing is changed,
2901 // see the comment in find_second_addp().)
2902 //
2903 while (alloc_worklist.length() != 0) {
2904 Node *n = alloc_worklist.pop();
2905 uint ni = n->_idx;
2906 if (n->is_Call()) {
2907 CallNode *alloc = n->as_Call();
2908 // copy escape information to call node
2909 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2910 PointsToNode::EscapeState es = ptn->escape_state();
2911 // We have an allocation or call which returns a Java object,
2912 // see if it is unescaped.
2913 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2914 continue;
2915 // Find CheckCastPP for the allocate or for the return value of a call
2916 n = alloc->result_cast();
2917 if (n == NULL) { // No uses except Initialize node
2918 if (alloc->is_Allocate()) {
2919 // Set the scalar_replaceable flag for allocation
2920 // so it could be eliminated if it has no uses.
2921 alloc->as_Allocate()->_is_scalar_replaceable = true;
2922 }
2923 if (alloc->is_CallStaticJava()) {
2924 // Set the scalar_replaceable flag for boxing method
2925 // so it could be eliminated if it has no uses.
2926 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2927 }
2928 continue;
2929 }
2930 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2931 assert(!alloc->is_Allocate(), "allocation should have unique type");
2932 continue;
2933 }
2934
2935 // The inline code for Object.clone() casts the allocation result to
2936 // java.lang.Object and then to the actual type of the allocated
2937 // object. Detect this case and use the second cast.
2938 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2939 // the allocation result is cast to java.lang.Object and then
2940 // to the actual Array type.
2941 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2942 && (alloc->is_AllocateArray() ||
2943 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2944 Node *cast2 = NULL;
2945 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2946 Node *use = n->fast_out(i);
2947 if (use->is_CheckCastPP()) {
2948 cast2 = use;
2949 break;
2950 }
2951 }
2952 if (cast2 != NULL) {
2953 n = cast2;
2954 } else {
2955 // Non-scalar replaceable if the allocation type is unknown statically
2956 // (reflection allocation), the object can't be restored during
2957 // deoptimization without precise type.
2958 continue;
2959 }
2960 }
2961
2962 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2963 if (t == NULL)
2964 continue; // not a TypeOopPtr
2965 if (!t->klass_is_exact())
2966 continue; // not an unique type
2967
2968 if (alloc->is_Allocate()) {
2969 // Set the scalar_replaceable flag for allocation
2970 // so it could be eliminated.
2971 alloc->as_Allocate()->_is_scalar_replaceable = true;
2972 }
2973 if (alloc->is_CallStaticJava()) {
2974 // Set the scalar_replaceable flag for boxing method
2975 // so it could be eliminated.
2976 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2977 }
2978 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2979 // in order for an object to be scalar-replaceable, it must be:
2980 // - a direct allocation (not a call returning an object)
2981 // - non-escaping
2982 // - eligible to be a unique type
2983 // - not determined to be ineligible by escape analysis
2984 set_map(alloc, n);
2985 set_map(n, alloc);
2986 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2987 igvn->hash_delete(n);
2988 igvn->set_type(n, tinst);
2989 n->raise_bottom_type(tinst);
2990 igvn->hash_insert(n);
2991 record_for_optimizer(n);
2992 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2993
2994 // First, put on the worklist all Field edges from Connection Graph
2995 // which is more accurate than putting immediate users from Ideal Graph.
2996 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2997 PointsToNode* tgt = e.get();
2998 if (tgt->is_Arraycopy()) {
2999 continue;
3000 }
3001 Node* use = tgt->ideal_node();
3002 assert(tgt->is_Field() && use->is_AddP(),
3003 "only AddP nodes are Field edges in CG");
3004 if (use->outcnt() > 0) { // Don't process dead nodes
3005 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3006 if (addp2 != NULL) {
3007 assert(alloc->is_AllocateArray(),"array allocation was expected");
3008 alloc_worklist.append_if_missing(addp2);
3009 }
3010 alloc_worklist.append_if_missing(use);
3011 }
3012 }
3013
3014 // An allocation may have an Initialize which has raw stores. Scan
3015 // the users of the raw allocation result and push AddP users
3016 // on alloc_worklist.
3017 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
3018 assert (raw_result != NULL, "must have an allocation result");
3019 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3020 Node *use = raw_result->fast_out(i);
3021 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3022 Node* addp2 = find_second_addp(use, raw_result);
3023 if (addp2 != NULL) {
3024 assert(alloc->is_AllocateArray(),"array allocation was expected");
3025 alloc_worklist.append_if_missing(addp2);
3026 }
3027 alloc_worklist.append_if_missing(use);
3028 } else if (use->is_MemBar()) {
3029 memnode_worklist.append_if_missing(use);
3030 }
3031 }
3032 }
3033 } else if (n->is_AddP()) {
3034 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3035 if (jobj == NULL || jobj == phantom_obj) {
3036 #ifdef ASSERT
3037 ptnode_adr(get_addp_base(n)->_idx)->dump();
3038 ptnode_adr(n->_idx)->dump();
3039 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3040 #endif
3041 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3042 return;
3043 }
3044 Node *base = get_map(jobj->idx()); // CheckCastPP node
3045 if (!split_AddP(n, base)) continue; // wrong type from dead path
3046 } else if (n->is_Phi() ||
3047 n->is_CheckCastPP() ||
3048 n->is_EncodeP() ||
3049 n->is_DecodeN() ||
3050 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3051 if (visited.test_set(n->_idx)) {
3052 assert(n->is_Phi(), "loops only through Phi's");
3053 continue; // already processed
3054 }
3055 JavaObjectNode* jobj = unique_java_object(n);
3056 if (jobj == NULL || jobj == phantom_obj) {
3057 #ifdef ASSERT
3058 ptnode_adr(n->_idx)->dump();
3059 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3060 #endif
3061 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3062 return;
3063 } else {
3064 Node *val = get_map(jobj->idx()); // CheckCastPP node
3065 TypeNode *tn = n->as_Type();
3066 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3067 assert(tinst != NULL && tinst->is_known_instance() &&
3068 tinst->instance_id() == jobj->idx() , "instance type expected.");
3069
3070 const Type *tn_type = igvn->type(tn);
3071 const TypeOopPtr *tn_t;
3072 if (tn_type->isa_narrowoop()) {
3073 tn_t = tn_type->make_ptr()->isa_oopptr();
3074 } else {
3075 tn_t = tn_type->isa_oopptr();
3076 }
3077 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3078 if (tn_type->isa_narrowoop()) {
3079 tn_type = tinst->make_narrowoop();
3080 } else {
3081 tn_type = tinst;
3082 }
3083 igvn->hash_delete(tn);
3084 igvn->set_type(tn, tn_type);
3085 tn->set_type(tn_type);
3086 igvn->hash_insert(tn);
3087 record_for_optimizer(n);
3088 } else {
3089 assert(tn_type == TypePtr::NULL_PTR ||
3090 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3091 "unexpected type");
3092 continue; // Skip dead path with different type
3093 }
3094 }
3095 } else {
3096 debug_only(n->dump();)
3097 assert(false, "EA: unexpected node");
3098 continue;
3099 }
3100 // push allocation's users on appropriate worklist
3101 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3102 Node *use = n->fast_out(i);
3103 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3104 // Load/store to instance's field
3105 memnode_worklist.append_if_missing(use);
3106 } else if (use->is_MemBar()) {
3107 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3108 memnode_worklist.append_if_missing(use);
3109 }
3110 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3111 Node* addp2 = find_second_addp(use, n);
3112 if (addp2 != NULL) {
3113 alloc_worklist.append_if_missing(addp2);
3114 }
3115 alloc_worklist.append_if_missing(use);
3116 } else if (use->is_Phi() ||
3117 use->is_CheckCastPP() ||
3118 use->is_EncodeNarrowPtr() ||
3119 use->is_DecodeNarrowPtr() ||
3120 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3121 alloc_worklist.append_if_missing(use);
3122 #ifdef ASSERT
3123 } else if (use->is_Mem()) {
3124 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3125 } else if (use->is_MergeMem()) {
3126 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3127 } else if (use->is_SafePoint()) {
3128 // Look for MergeMem nodes for calls which reference unique allocation
3129 // (through CheckCastPP nodes) even for debug info.
3130 Node* m = use->in(TypeFunc::Memory);
3131 if (m->is_MergeMem()) {
3132 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3133 }
3134 } else if (use->Opcode() == Op_EncodeISOArray) {
3135 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3136 // EncodeISOArray overwrites destination array
3137 memnode_worklist.append_if_missing(use);
3138 }
3139 } else {
3140 uint op = use->Opcode();
3141 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3142 (use->in(MemNode::Memory) == n)) {
3143 // They overwrite memory edge corresponding to destination array,
3144 memnode_worklist.append_if_missing(use);
3145 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3146 op == Op_CastP2X || op == Op_StoreCM ||
3147 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3148 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3149 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3150 n->dump();
3151 use->dump();
3152 assert(false, "EA: missing allocation reference path");
3153 }
3154 #endif
3155 }
3156 }
3157
3158 }
3159
3160 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3161 // type, record it in the ArrayCopy node so we know what memory this
3162 // node uses/modified.
3163 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3164 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3165 Node* dest = ac->in(ArrayCopyNode::Dest);
3166 if (dest->is_AddP()) {
3167 dest = get_addp_base(dest);
3168 }
3169 JavaObjectNode* jobj = unique_java_object(dest);
3170 if (jobj != NULL) {
3171 Node *base = get_map(jobj->idx());
3172 if (base != NULL) {
3173 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3174 ac->_dest_type = base_t;
3175 }
3176 }
3177 Node* src = ac->in(ArrayCopyNode::Src);
3178 if (src->is_AddP()) {
3179 src = get_addp_base(src);
3180 }
3181 jobj = unique_java_object(src);
3182 if (jobj != NULL) {
3183 Node* base = get_map(jobj->idx());
3184 if (base != NULL) {
3185 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3186 ac->_src_type = base_t;
3187 }
3188 }
3189 }
3190
3191 // New alias types were created in split_AddP().
3192 uint new_index_end = (uint) _compile->num_alias_types();
3193 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3194
3195 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3196 // compute new values for Memory inputs (the Memory inputs are not
3197 // actually updated until phase 4.)
3198 if (memnode_worklist.length() == 0)
3199 return; // nothing to do
3200 while (memnode_worklist.length() != 0) {
3201 Node *n = memnode_worklist.pop();
3202 if (visited.test_set(n->_idx))
3203 continue;
3204 if (n->is_Phi() || n->is_ClearArray()) {
3205 // we don't need to do anything, but the users must be pushed
3206 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3207 // we don't need to do anything, but the users must be pushed
3208 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3209 if (n == NULL)
3210 continue;
3211 } else if (n->Opcode() == Op_StrCompressedCopy ||
3212 n->Opcode() == Op_EncodeISOArray) {
3213 // get the memory projection
3214 n = n->find_out_with(Op_SCMemProj);
3215 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3216 } else {
3217 assert(n->is_Mem(), "memory node required.");
3218 Node *addr = n->in(MemNode::Address);
3219 const Type *addr_t = igvn->type(addr);
3220 if (addr_t == Type::TOP)
3221 continue;
3222 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3223 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3224 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3225 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3226 if (_compile->failing()) {
3227 return;
3228 }
3229 if (mem != n->in(MemNode::Memory)) {
3230 // We delay the memory edge update since we need old one in
3231 // MergeMem code below when instances memory slices are separated.
3232 set_map(n, mem);
3233 }
3234 if (n->is_Load()) {
3235 continue; // don't push users
3236 } else if (n->is_LoadStore()) {
3237 // get the memory projection
3238 n = n->find_out_with(Op_SCMemProj);
3239 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3240 }
3241 }
3242 // push user on appropriate worklist
3243 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3244 Node *use = n->fast_out(i);
3245 if (use->is_Phi() || use->is_ClearArray()) {
3246 memnode_worklist.append_if_missing(use);
3247 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3248 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3249 continue;
3250 memnode_worklist.append_if_missing(use);
3251 } else if (use->is_MemBar()) {
3252 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3253 memnode_worklist.append_if_missing(use);
3254 }
3255 #ifdef ASSERT
3256 } else if(use->is_Mem()) {
3257 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3258 } else if (use->is_MergeMem()) {
3259 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3260 } else if (use->Opcode() == Op_EncodeISOArray) {
3261 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3262 // EncodeISOArray overwrites destination array
3263 memnode_worklist.append_if_missing(use);
3264 }
3265 } else {
3266 uint op = use->Opcode();
3267 if ((use->in(MemNode::Memory) == n) &&
3268 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3269 // They overwrite memory edge corresponding to destination array,
3270 memnode_worklist.append_if_missing(use);
3271 } else if (!(Universe::heap()->barrier_set()->c2_code_gen()->is_gc_barrier_node(use) ||
3272 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3273 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3274 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3275 n->dump();
3276 use->dump();
3277 assert(false, "EA: missing memory path");
3278 }
3279 #endif
3280 }
3281 }
3282 }
3283
3284 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3285 // Walk each memory slice moving the first node encountered of each
3286 // instance type to the the input corresponding to its alias index.
3287 uint length = _mergemem_worklist.length();
3288 for( uint next = 0; next < length; ++next ) {
3289 MergeMemNode* nmm = _mergemem_worklist.at(next);
3290 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3291 // Note: we don't want to use MergeMemStream here because we only want to
3292 // scan inputs which exist at the start, not ones we add during processing.
3293 // Note 2: MergeMem may already contains instance memory slices added
3294 // during find_inst_mem() call when memory nodes were processed above.
3295 igvn->hash_delete(nmm);
3296 uint nslices = MIN2(nmm->req(), new_index_start);
3297 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3298 Node* mem = nmm->in(i);
3299 Node* cur = NULL;
3300 if (mem == NULL || mem->is_top())
3301 continue;
3302 // First, update mergemem by moving memory nodes to corresponding slices
3303 // if their type became more precise since this mergemem was created.
3304 while (mem->is_Mem()) {
3305 const Type *at = igvn->type(mem->in(MemNode::Address));
3306 if (at != Type::TOP) {
3307 assert (at->isa_ptr() != NULL, "pointer type required.");
3308 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3309 if (idx == i) {
3310 if (cur == NULL)
3311 cur = mem;
3312 } else {
3313 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3314 nmm->set_memory_at(idx, mem);
3315 }
3316 }
3317 }
3318 mem = mem->in(MemNode::Memory);
3319 }
3320 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3321 // Find any instance of the current type if we haven't encountered
3322 // already a memory slice of the instance along the memory chain.
3323 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3324 if((uint)_compile->get_general_index(ni) == i) {
3325 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3326 if (nmm->is_empty_memory(m)) {
3327 Node* result = find_inst_mem(mem, ni, orig_phis);
3328 if (_compile->failing()) {
3329 return;
3330 }
3331 nmm->set_memory_at(ni, result);
3332 }
3333 }
3334 }
3335 }
3336 // Find the rest of instances values
3337 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3338 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3339 Node* result = step_through_mergemem(nmm, ni, tinst);
3340 if (result == nmm->base_memory()) {
3341 // Didn't find instance memory, search through general slice recursively.
3342 result = nmm->memory_at(_compile->get_general_index(ni));
3343 result = find_inst_mem(result, ni, orig_phis);
3344 if (_compile->failing()) {
3345 return;
3346 }
3347 nmm->set_memory_at(ni, result);
3348 }
3349 }
3350 igvn->hash_insert(nmm);
3351 record_for_optimizer(nmm);
3352 }
3353
3354 // Phase 4: Update the inputs of non-instance memory Phis and
3355 // the Memory input of memnodes
3356 // First update the inputs of any non-instance Phi's from
3357 // which we split out an instance Phi. Note we don't have
3358 // to recursively process Phi's encounted on the input memory
3359 // chains as is done in split_memory_phi() since they will
3360 // also be processed here.
3361 for (int j = 0; j < orig_phis.length(); j++) {
3362 PhiNode *phi = orig_phis.at(j);
3363 int alias_idx = _compile->get_alias_index(phi->adr_type());
3364 igvn->hash_delete(phi);
3365 for (uint i = 1; i < phi->req(); i++) {
3366 Node *mem = phi->in(i);
3367 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3368 if (_compile->failing()) {
3369 return;
3370 }
3371 if (mem != new_mem) {
3372 phi->set_req(i, new_mem);
3373 }
3374 }
3375 igvn->hash_insert(phi);
3376 record_for_optimizer(phi);
3377 }
3378
3379 // Update the memory inputs of MemNodes with the value we computed
3380 // in Phase 2 and move stores memory users to corresponding memory slices.
3381 // Disable memory split verification code until the fix for 6984348.
3382 // Currently it produces false negative results since it does not cover all cases.
3383 #if 0 // ifdef ASSERT
3384 visited.Reset();
3385 Node_Stack old_mems(arena, _compile->unique() >> 2);
3386 #endif
3387 for (uint i = 0; i < ideal_nodes.size(); i++) {
3388 Node* n = ideal_nodes.at(i);
3389 Node* nmem = get_map(n->_idx);
3390 assert(nmem != NULL, "sanity");
3391 if (n->is_Mem()) {
3392 #if 0 // ifdef ASSERT
3393 Node* old_mem = n->in(MemNode::Memory);
3394 if (!visited.test_set(old_mem->_idx)) {
3395 old_mems.push(old_mem, old_mem->outcnt());
3396 }
3397 #endif
3398 assert(n->in(MemNode::Memory) != nmem, "sanity");
3399 if (!n->is_Load()) {
3400 // Move memory users of a store first.
3401 move_inst_mem(n, orig_phis);
3402 }
3403 // Now update memory input
3404 igvn->hash_delete(n);
3405 n->set_req(MemNode::Memory, nmem);
3406 igvn->hash_insert(n);
3407 record_for_optimizer(n);
3408 } else {
3409 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3410 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3411 }
3412 }
3413 #if 0 // ifdef ASSERT
3414 // Verify that memory was split correctly
3415 while (old_mems.is_nonempty()) {
3416 Node* old_mem = old_mems.node();
3417 uint old_cnt = old_mems.index();
3418 old_mems.pop();
3419 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3420 }
3421 #endif
3422 }
3423
3424 #ifndef PRODUCT
3425 static const char *node_type_names[] = {
3426 "UnknownType",
3427 "JavaObject",
3428 "LocalVar",
3429 "Field",
3430 "Arraycopy"
3431 };
3432
3433 static const char *esc_names[] = {
3434 "UnknownEscape",
3435 "NoEscape",
3436 "ArgEscape",
3437 "GlobalEscape"
3438 };
3439
3440 void PointsToNode::dump(bool print_state) const {
3441 NodeType nt = node_type();
3442 tty->print("%s ", node_type_names[(int) nt]);
3443 if (print_state) {
3444 EscapeState es = escape_state();
3445 EscapeState fields_es = fields_escape_state();
3446 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3447 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3448 tty->print("NSR ");
3449 }
3450 if (is_Field()) {
3451 FieldNode* f = (FieldNode*)this;
3452 if (f->is_oop())
3453 tty->print("oop ");
3454 if (f->offset() > 0)
3455 tty->print("+%d ", f->offset());
3456 tty->print("(");
3457 for (BaseIterator i(f); i.has_next(); i.next()) {
3458 PointsToNode* b = i.get();
3459 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3460 }
3461 tty->print(" )");
3462 }
3463 tty->print("[");
3464 for (EdgeIterator i(this); i.has_next(); i.next()) {
3465 PointsToNode* e = i.get();
3466 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3467 }
3468 tty->print(" [");
3469 for (UseIterator i(this); i.has_next(); i.next()) {
3470 PointsToNode* u = i.get();
3471 bool is_base = false;
3472 if (PointsToNode::is_base_use(u)) {
3473 is_base = true;
3474 u = PointsToNode::get_use_node(u)->as_Field();
3475 }
3476 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3477 }
3478 tty->print(" ]] ");
3479 if (_node == NULL)
3480 tty->print_cr("<null>");
3481 else
3482 _node->dump();
3483 }
3484
3485 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3486 bool first = true;
3487 int ptnodes_length = ptnodes_worklist.length();
3488 for (int i = 0; i < ptnodes_length; i++) {
3489 PointsToNode *ptn = ptnodes_worklist.at(i);
3490 if (ptn == NULL || !ptn->is_JavaObject())
3491 continue;
3492 PointsToNode::EscapeState es = ptn->escape_state();
3493 if ((es != PointsToNode::NoEscape) && !Verbose) {
3494 continue;
3495 }
3496 Node* n = ptn->ideal_node();
3497 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3498 n->as_CallStaticJava()->is_boxing_method())) {
3499 if (first) {
3500 tty->cr();
3501 tty->print("======== Connection graph for ");
3502 _compile->method()->print_short_name();
3503 tty->cr();
3504 first = false;
3505 }
3506 ptn->dump();
3507 // Print all locals and fields which reference this allocation
3508 for (UseIterator j(ptn); j.has_next(); j.next()) {
3509 PointsToNode* use = j.get();
3510 if (use->is_LocalVar()) {
3511 use->dump(Verbose);
3512 } else if (Verbose) {
3513 use->dump();
3514 }
3515 }
3516 tty->cr();
3517 }
3518 }
3519 }
3520 #endif