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