1 /*
2 * Copyright (c) 2005, 2014, 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 _collecting(true),
42 _verify(false),
43 _compile(C),
44 _igvn(igvn),
45 _node_map(C->comp_arena()) {
46 // Add unknown java object.
47 add_java_object(C->top(), PointsToNode::GlobalEscape);
48 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
49 // Add ConP(#NULL) and ConN(#NULL) nodes.
50 Node* oop_null = igvn->zerocon(T_OBJECT);
51 assert(oop_null->_idx < nodes_size(), "should be created already");
52 add_java_object(oop_null, PointsToNode::NoEscape);
53 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
54 if (UseCompressedOops) {
55 Node* noop_null = igvn->zerocon(T_NARROWOOP);
56 assert(noop_null->_idx < nodes_size(), "should be created already");
57 map_ideal_node(noop_null, null_obj);
58 }
59 _pcmp_neq = NULL; // Should be initialized
60 _pcmp_eq = NULL;
61 }
62
63 bool ConnectionGraph::has_candidates(Compile *C) {
64 // EA brings benefits only when the code has allocations and/or locks which
65 // are represented by ideal Macro nodes.
66 int cnt = C->macro_count();
67 for (int i = 0; i < cnt; i++) {
68 Node *n = C->macro_node(i);
69 if (n->is_Allocate())
70 return true;
71 if (n->is_Lock()) {
72 Node* obj = n->as_Lock()->obj_node()->uncast();
73 if (!(obj->is_Parm() || obj->is_Con()))
74 return true;
75 }
76 if (n->is_CallStaticJava() &&
77 n->as_CallStaticJava()->is_boxing_method()) {
78 return true;
79 }
80 }
81 return false;
82 }
83
84 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
85 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
86 ResourceMark rm;
87
88 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
89 // to create space for them in ConnectionGraph::_nodes[].
90 Node* oop_null = igvn->zerocon(T_OBJECT);
91 Node* noop_null = igvn->zerocon(T_NARROWOOP);
92 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
93 // Perform escape analysis
94 if (congraph->compute_escape()) {
95 // There are non escaping objects.
96 C->set_congraph(congraph);
97 }
98 // Cleanup.
99 if (oop_null->outcnt() == 0)
100 igvn->hash_delete(oop_null);
101 if (noop_null->outcnt() == 0)
102 igvn->hash_delete(noop_null);
103 }
104
105 bool ConnectionGraph::compute_escape() {
106 Compile* C = _compile;
107 PhaseGVN* igvn = _igvn;
108
109 // Worklists used by EA.
110 Unique_Node_List delayed_worklist;
111 GrowableArray<Node*> alloc_worklist;
112 GrowableArray<Node*> ptr_cmp_worklist;
113 GrowableArray<Node*> storestore_worklist;
114 GrowableArray<PointsToNode*> ptnodes_worklist;
115 GrowableArray<JavaObjectNode*> java_objects_worklist;
116 GrowableArray<JavaObjectNode*> non_escaped_worklist;
117 GrowableArray<FieldNode*> oop_fields_worklist;
118 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
119
120 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
121
122 // 1. Populate Connection Graph (CG) with PointsTo nodes.
123 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
124 // Initialize worklist
125 if (C->root() != NULL) {
126 ideal_nodes.push(C->root());
127 }
128 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
129 Node* n = ideal_nodes.at(next);
130 // Create PointsTo nodes and add them to Connection Graph. Called
131 // only once per ideal node since ideal_nodes is Unique_Node list.
132 add_node_to_connection_graph(n, &delayed_worklist);
133 PointsToNode* ptn = ptnode_adr(n->_idx);
134 if (ptn != NULL) {
135 ptnodes_worklist.append(ptn);
136 if (ptn->is_JavaObject()) {
137 java_objects_worklist.append(ptn->as_JavaObject());
138 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
139 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
140 // Only allocations and java static calls results are interesting.
141 non_escaped_worklist.append(ptn->as_JavaObject());
142 }
143 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
144 oop_fields_worklist.append(ptn->as_Field());
145 }
146 }
147 if (n->is_MergeMem()) {
148 // Collect all MergeMem nodes to add memory slices for
149 // scalar replaceable objects in split_unique_types().
150 _mergemem_worklist.append(n->as_MergeMem());
151 } else if (OptimizePtrCompare && n->is_Cmp() &&
152 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
153 // Collect compare pointers nodes.
154 ptr_cmp_worklist.append(n);
155 } else if (n->is_MemBarStoreStore()) {
156 // Collect all MemBarStoreStore nodes so that depending on the
157 // escape status of the associated Allocate node some of them
158 // may be eliminated.
159 storestore_worklist.append(n);
160 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
161 (n->req() > MemBarNode::Precedent)) {
162 record_for_optimizer(n);
163 #ifdef ASSERT
164 } else if (n->is_AddP()) {
165 // Collect address nodes for graph verification.
166 addp_worklist.append(n);
167 #endif
168 }
169 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
170 Node* m = n->fast_out(i); // Get user
171 ideal_nodes.push(m);
172 }
173 }
174 if (non_escaped_worklist.length() == 0) {
175 _collecting = false;
176 return false; // Nothing to do.
177 }
178 // Add final simple edges to graph.
179 while(delayed_worklist.size() > 0) {
180 Node* n = delayed_worklist.pop();
181 add_final_edges(n);
182 }
183 int ptnodes_length = ptnodes_worklist.length();
184
185 #ifdef ASSERT
186 if (VerifyConnectionGraph) {
187 // Verify that no new simple edges could be created and all
188 // local vars has edges.
189 _verify = true;
190 for (int next = 0; next < ptnodes_length; ++next) {
191 PointsToNode* ptn = ptnodes_worklist.at(next);
192 add_final_edges(ptn->ideal_node());
193 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
194 ptn->dump();
195 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
196 }
197 }
198 _verify = false;
199 }
200 #endif
201
202 // 2. Finish Graph construction by propagating references to all
203 // java objects through graph.
204 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
205 java_objects_worklist, oop_fields_worklist)) {
206 // All objects escaped or hit time or iterations limits.
207 _collecting = false;
208 return false;
209 }
210
211 // 3. Adjust scalar_replaceable state of nonescaping objects and push
212 // scalar replaceable allocations on alloc_worklist for processing
213 // in split_unique_types().
214 int non_escaped_length = non_escaped_worklist.length();
215 for (int next = 0; next < non_escaped_length; next++) {
216 JavaObjectNode* ptn = non_escaped_worklist.at(next);
217 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
218 Node* n = ptn->ideal_node();
219 if (n->is_Allocate()) {
220 n->as_Allocate()->_is_non_escaping = noescape;
221 }
222 if (n->is_CallStaticJava()) {
223 n->as_CallStaticJava()->_is_non_escaping = noescape;
224 }
225 if (noescape && ptn->scalar_replaceable()) {
226 adjust_scalar_replaceable_state(ptn);
227 if (ptn->scalar_replaceable()) {
228 alloc_worklist.append(ptn->ideal_node());
229 }
230 }
231 }
232
233 #ifdef ASSERT
234 if (VerifyConnectionGraph) {
235 // Verify that graph is complete - no new edges could be added or needed.
236 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
237 java_objects_worklist, addp_worklist);
238 }
239 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
240 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
241 null_obj->edge_count() == 0 &&
242 !null_obj->arraycopy_src() &&
243 !null_obj->arraycopy_dst(), "sanity");
244 #endif
245
246 _collecting = false;
247
248 } // TracePhase t3("connectionGraph")
249
250 // 4. Optimize ideal graph based on EA information.
251 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
252 if (has_non_escaping_obj) {
253 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
254 }
255
256 #ifndef PRODUCT
257 if (PrintEscapeAnalysis) {
258 dump(ptnodes_worklist); // Dump ConnectionGraph
259 }
260 #endif
261
262 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
263 #ifdef ASSERT
264 if (VerifyConnectionGraph) {
265 int alloc_length = alloc_worklist.length();
266 for (int next = 0; next < alloc_length; ++next) {
267 Node* n = alloc_worklist.at(next);
268 PointsToNode* ptn = ptnode_adr(n->_idx);
269 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
270 }
271 }
272 #endif
273
274 // 5. Separate memory graph for scalar replaceable allcations.
275 if (has_scalar_replaceable_candidates &&
276 C->AliasLevel() >= 3 && EliminateAllocations) {
277 // Now use the escape information to create unique types for
278 // scalar replaceable objects.
279 split_unique_types(alloc_worklist);
280 if (C->failing()) return false;
281 C->print_method(PHASE_AFTER_EA, 2);
282
283 #ifdef ASSERT
284 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
285 tty->print("=== No allocations eliminated for ");
286 C->method()->print_short_name();
287 if(!EliminateAllocations) {
288 tty->print(" since EliminateAllocations is off ===");
289 } else if(!has_scalar_replaceable_candidates) {
290 tty->print(" since there are no scalar replaceable candidates ===");
291 } else if(C->AliasLevel() < 3) {
292 tty->print(" since AliasLevel < 3 ===");
293 }
294 tty->cr();
295 #endif
296 }
297 return has_non_escaping_obj;
298 }
299
300 // Utility function for nodes that load an object
301 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
302 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
303 // ThreadLocal has RawPtr type.
304 const Type* t = _igvn->type(n);
305 if (t->make_ptr() != NULL) {
306 Node* adr = n->in(MemNode::Address);
307 #ifdef ASSERT
308 if (!adr->is_AddP()) {
309 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
310 } else {
311 assert((ptnode_adr(adr->_idx) == NULL ||
312 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
313 }
314 #endif
315 add_local_var_and_edge(n, PointsToNode::NoEscape,
316 adr, delayed_worklist);
317 }
318 }
319
320 // Populate Connection Graph with PointsTo nodes and create simple
321 // connection graph edges.
322 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
323 assert(!_verify, "this method sould not be called for verification");
324 PhaseGVN* igvn = _igvn;
325 uint n_idx = n->_idx;
326 PointsToNode* n_ptn = ptnode_adr(n_idx);
327 if (n_ptn != NULL)
328 return; // No need to redefine PointsTo node during first iteration.
329
330 if (n->is_Call()) {
331 // Arguments to allocation and locking don't escape.
332 if (n->is_AbstractLock()) {
333 // Put Lock and Unlock nodes on IGVN worklist to process them during
334 // first IGVN optimization when escape information is still available.
335 record_for_optimizer(n);
336 } else if (n->is_Allocate()) {
337 add_call_node(n->as_Call());
338 record_for_optimizer(n);
339 } else {
340 if (n->is_CallStaticJava()) {
341 const char* name = n->as_CallStaticJava()->_name;
342 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
343 return; // Skip uncommon traps
344 }
345 // Don't mark as processed since call's arguments have to be processed.
346 delayed_worklist->push(n);
347 // Check if a call returns an object.
348 if ((n->as_Call()->returns_pointer() &&
349 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
350 (n->is_CallStaticJava() &&
351 n->as_CallStaticJava()->is_boxing_method())) {
352 add_call_node(n->as_Call());
353 }
354 }
355 return;
356 }
357 // Put this check here to process call arguments since some call nodes
358 // point to phantom_obj.
359 if (n_ptn == phantom_obj || n_ptn == null_obj)
360 return; // Skip predefined nodes.
361
362 int opcode = n->Opcode();
363 switch (opcode) {
364 case Op_AddP: {
365 Node* base = get_addp_base(n);
366 PointsToNode* ptn_base = ptnode_adr(base->_idx);
367 // Field nodes are created for all field types. They are used in
368 // adjust_scalar_replaceable_state() and split_unique_types().
369 // Note, non-oop fields will have only base edges in Connection
370 // Graph because such fields are not used for oop loads and stores.
371 int offset = address_offset(n, igvn);
372 add_field(n, PointsToNode::NoEscape, offset);
373 if (ptn_base == NULL) {
374 delayed_worklist->push(n); // Process it later.
375 } else {
376 n_ptn = ptnode_adr(n_idx);
377 add_base(n_ptn->as_Field(), ptn_base);
378 }
379 break;
380 }
381 case Op_CastX2P: {
382 map_ideal_node(n, phantom_obj);
383 break;
384 }
385 case Op_CastPP:
386 case Op_CheckCastPP:
387 case Op_EncodeP:
388 case Op_DecodeN:
389 case Op_EncodePKlass:
390 case Op_DecodeNKlass: {
391 add_local_var_and_edge(n, PointsToNode::NoEscape,
392 n->in(1), delayed_worklist);
393 break;
394 }
395 case Op_CMoveP: {
396 add_local_var(n, PointsToNode::NoEscape);
397 // Do not add edges during first iteration because some could be
398 // not defined yet.
399 delayed_worklist->push(n);
400 break;
401 }
402 case Op_ConP:
403 case Op_ConN:
404 case Op_ConNKlass: {
405 // assume all oop constants globally escape except for null
406 PointsToNode::EscapeState es;
407 const Type* t = igvn->type(n);
408 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
409 es = PointsToNode::NoEscape;
410 } else {
411 es = PointsToNode::GlobalEscape;
412 }
413 add_java_object(n, es);
414 break;
415 }
416 case Op_CreateEx: {
417 // assume that all exception objects globally escape
418 add_java_object(n, PointsToNode::GlobalEscape);
419 break;
420 }
421 case Op_LoadKlass:
422 case Op_LoadNKlass: {
423 // Unknown class is loaded
424 map_ideal_node(n, phantom_obj);
425 break;
426 }
427 case Op_LoadP:
428 case Op_LoadN:
429 case Op_LoadPLocked: {
430 add_objload_to_connection_graph(n, delayed_worklist);
431 break;
432 }
433 case Op_Parm: {
434 map_ideal_node(n, phantom_obj);
435 break;
436 }
437 case Op_PartialSubtypeCheck: {
438 // Produces Null or notNull and is used in only in CmpP so
439 // phantom_obj could be used.
440 map_ideal_node(n, phantom_obj); // Result is unknown
441 break;
442 }
443 case Op_Phi: {
444 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
445 // ThreadLocal has RawPtr type.
446 const Type* t = n->as_Phi()->type();
447 if (t->make_ptr() != NULL) {
448 add_local_var(n, PointsToNode::NoEscape);
449 // Do not add edges during first iteration because some could be
450 // not defined yet.
451 delayed_worklist->push(n);
452 }
453 break;
454 }
455 case Op_Proj: {
456 // we are only interested in the oop result projection from a call
457 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
458 n->in(0)->as_Call()->returns_pointer()) {
459 add_local_var_and_edge(n, PointsToNode::NoEscape,
460 n->in(0), delayed_worklist);
461 }
462 break;
463 }
464 case Op_Rethrow: // Exception object escapes
465 case Op_Return: {
466 if (n->req() > TypeFunc::Parms &&
467 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
468 // Treat Return value as LocalVar with GlobalEscape escape state.
469 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
470 n->in(TypeFunc::Parms), delayed_worklist);
471 }
472 break;
473 }
474 case Op_GetAndSetP:
475 case Op_GetAndSetN: {
476 add_objload_to_connection_graph(n, delayed_worklist);
477 // fallthrough
478 }
479 case Op_StoreP:
480 case Op_StoreN:
481 case Op_StoreNKlass:
482 case Op_StorePConditional:
483 case Op_CompareAndSwapP:
484 case Op_CompareAndSwapN: {
485 Node* adr = n->in(MemNode::Address);
486 const Type *adr_type = igvn->type(adr);
487 adr_type = adr_type->make_ptr();
488 if (adr_type == NULL) {
489 break; // skip dead nodes
490 }
491 if (adr_type->isa_oopptr() ||
492 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
493 (adr_type == TypeRawPtr::NOTNULL &&
494 adr->in(AddPNode::Address)->is_Proj() &&
495 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
496 delayed_worklist->push(n); // Process it later.
497 #ifdef ASSERT
498 assert(adr->is_AddP(), "expecting an AddP");
499 if (adr_type == TypeRawPtr::NOTNULL) {
500 // Verify a raw address for a store captured by Initialize node.
501 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
502 assert(offs != Type::OffsetBot, "offset must be a constant");
503 }
504 #endif
505 } else {
506 // Ignore copy the displaced header to the BoxNode (OSR compilation).
507 if (adr->is_BoxLock())
508 break;
509 // Stored value escapes in unsafe access.
510 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
511 // Pointer stores in G1 barriers looks like unsafe access.
512 // Ignore such stores to be able scalar replace non-escaping
513 // allocations.
514 if (UseG1GC && adr->is_AddP()) {
515 Node* base = get_addp_base(adr);
516 if (base->Opcode() == Op_LoadP &&
517 base->in(MemNode::Address)->is_AddP()) {
518 adr = base->in(MemNode::Address);
519 Node* tls = get_addp_base(adr);
520 if (tls->Opcode() == Op_ThreadLocal) {
521 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
522 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
523 PtrQueue::byte_offset_of_buf())) {
524 break; // G1 pre barier previous oop value store.
525 }
526 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
527 PtrQueue::byte_offset_of_buf())) {
528 break; // G1 post barier card address store.
529 }
530 }
531 }
532 }
533 delayed_worklist->push(n); // Process unsafe access later.
534 break;
535 }
536 #ifdef ASSERT
537 n->dump(1);
538 assert(false, "not unsafe or G1 barrier raw StoreP");
539 #endif
540 }
541 break;
542 }
543 case Op_AryEq:
544 case Op_StrComp:
545 case Op_StrEquals:
546 case Op_StrIndexOf:
547 case Op_EncodeISOArray: {
548 add_local_var(n, PointsToNode::ArgEscape);
549 delayed_worklist->push(n); // Process it later.
550 break;
551 }
552 case Op_ThreadLocal: {
553 add_java_object(n, PointsToNode::ArgEscape);
554 break;
555 }
556 default:
557 ; // Do nothing for nodes not related to EA.
558 }
559 return;
560 }
561
562 #ifdef ASSERT
563 #define ELSE_FAIL(name) \
564 /* Should not be called for not pointer type. */ \
565 n->dump(1); \
566 assert(false, name); \
567 break;
568 #else
569 #define ELSE_FAIL(name) \
570 break;
571 #endif
572
573 // Add final simple edges to graph.
574 void ConnectionGraph::add_final_edges(Node *n) {
575 PointsToNode* n_ptn = ptnode_adr(n->_idx);
576 #ifdef ASSERT
577 if (_verify && n_ptn->is_JavaObject())
578 return; // This method does not change graph for JavaObject.
579 #endif
580
581 if (n->is_Call()) {
582 process_call_arguments(n->as_Call());
583 return;
584 }
585 assert(n->is_Store() || n->is_LoadStore() ||
586 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
587 "node should be registered already");
588 int opcode = n->Opcode();
589 switch (opcode) {
590 case Op_AddP: {
591 Node* base = get_addp_base(n);
592 PointsToNode* ptn_base = ptnode_adr(base->_idx);
593 assert(ptn_base != NULL, "field's base should be registered");
594 add_base(n_ptn->as_Field(), ptn_base);
595 break;
596 }
597 case Op_CastPP:
598 case Op_CheckCastPP:
599 case Op_EncodeP:
600 case Op_DecodeN:
601 case Op_EncodePKlass:
602 case Op_DecodeNKlass: {
603 add_local_var_and_edge(n, PointsToNode::NoEscape,
604 n->in(1), NULL);
605 break;
606 }
607 case Op_CMoveP: {
608 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
609 Node* in = n->in(i);
610 if (in == NULL)
611 continue; // ignore NULL
612 Node* uncast_in = in->uncast();
613 if (uncast_in->is_top() || uncast_in == n)
614 continue; // ignore top or inputs which go back this node
615 PointsToNode* ptn = ptnode_adr(in->_idx);
616 assert(ptn != NULL, "node should be registered");
617 add_edge(n_ptn, ptn);
618 }
619 break;
620 }
621 case Op_LoadP:
622 case Op_LoadN:
623 case Op_LoadPLocked: {
624 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
625 // ThreadLocal has RawPtr type.
626 const Type* t = _igvn->type(n);
627 if (t->make_ptr() != NULL) {
628 Node* adr = n->in(MemNode::Address);
629 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
630 break;
631 }
632 ELSE_FAIL("Op_LoadP");
633 }
634 case Op_Phi: {
635 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
636 // ThreadLocal has RawPtr type.
637 const Type* t = n->as_Phi()->type();
638 if (t->make_ptr() != NULL) {
639 for (uint i = 1; i < n->req(); i++) {
640 Node* in = n->in(i);
641 if (in == NULL)
642 continue; // ignore NULL
643 Node* uncast_in = in->uncast();
644 if (uncast_in->is_top() || uncast_in == n)
645 continue; // ignore top or inputs which go back this node
646 PointsToNode* ptn = ptnode_adr(in->_idx);
647 assert(ptn != NULL, "node should be registered");
648 add_edge(n_ptn, ptn);
649 }
650 break;
651 }
652 ELSE_FAIL("Op_Phi");
653 }
654 case Op_Proj: {
655 // we are only interested in the oop result projection from a call
656 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
657 n->in(0)->as_Call()->returns_pointer()) {
658 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
659 break;
660 }
661 ELSE_FAIL("Op_Proj");
662 }
663 case Op_Rethrow: // Exception object escapes
664 case Op_Return: {
665 if (n->req() > TypeFunc::Parms &&
666 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
667 // Treat Return value as LocalVar with GlobalEscape escape state.
668 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
669 n->in(TypeFunc::Parms), NULL);
670 break;
671 }
672 ELSE_FAIL("Op_Return");
673 }
674 case Op_StoreP:
675 case Op_StoreN:
676 case Op_StoreNKlass:
677 case Op_StorePConditional:
678 case Op_CompareAndSwapP:
679 case Op_CompareAndSwapN:
680 case Op_GetAndSetP:
681 case Op_GetAndSetN: {
682 Node* adr = n->in(MemNode::Address);
683 const Type *adr_type = _igvn->type(adr);
684 adr_type = adr_type->make_ptr();
685 #ifdef ASSERT
686 if (adr_type == NULL) {
687 n->dump(1);
688 assert(adr_type != NULL, "dead node should not be on list");
689 break;
690 }
691 #endif
692 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
693 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
694 }
695 if (adr_type->isa_oopptr() ||
696 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
697 (adr_type == TypeRawPtr::NOTNULL &&
698 adr->in(AddPNode::Address)->is_Proj() &&
699 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
700 // Point Address to Value
701 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
702 assert(adr_ptn != NULL &&
703 adr_ptn->as_Field()->is_oop(), "node should be registered");
704 Node *val = n->in(MemNode::ValueIn);
705 PointsToNode* ptn = ptnode_adr(val->_idx);
706 assert(ptn != NULL, "node should be registered");
707 add_edge(adr_ptn, ptn);
708 break;
709 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
710 // Stored value escapes in unsafe access.
711 Node *val = n->in(MemNode::ValueIn);
712 PointsToNode* ptn = ptnode_adr(val->_idx);
713 assert(ptn != NULL, "node should be registered");
714 set_escape_state(ptn, PointsToNode::GlobalEscape);
715 // Add edge to object for unsafe access with offset.
716 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
717 assert(adr_ptn != NULL, "node should be registered");
718 if (adr_ptn->is_Field()) {
719 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
720 add_edge(adr_ptn, ptn);
721 }
722 break;
723 }
724 ELSE_FAIL("Op_StoreP");
725 }
726 case Op_AryEq:
727 case Op_StrComp:
728 case Op_StrEquals:
729 case Op_StrIndexOf:
730 case Op_EncodeISOArray: {
731 // char[] arrays passed to string intrinsic do not escape but
732 // they are not scalar replaceable. Adjust escape state for them.
733 // Start from in(2) edge since in(1) is memory edge.
734 for (uint i = 2; i < n->req(); i++) {
735 Node* adr = n->in(i);
736 const Type* at = _igvn->type(adr);
737 if (!adr->is_top() && at->isa_ptr()) {
738 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
739 at->isa_ptr() != NULL, "expecting a pointer");
740 if (adr->is_AddP()) {
741 adr = get_addp_base(adr);
742 }
743 PointsToNode* ptn = ptnode_adr(adr->_idx);
744 assert(ptn != NULL, "node should be registered");
745 add_edge(n_ptn, ptn);
746 }
747 }
748 break;
749 }
750 default: {
751 // This method should be called only for EA specific nodes which may
752 // miss some edges when they were created.
753 #ifdef ASSERT
754 n->dump(1);
755 #endif
756 guarantee(false, "unknown node");
757 }
758 }
759 return;
760 }
761
762 void ConnectionGraph::add_call_node(CallNode* call) {
763 assert(call->returns_pointer(), "only for call which returns pointer");
764 uint call_idx = call->_idx;
765 if (call->is_Allocate()) {
766 Node* k = call->in(AllocateNode::KlassNode);
767 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
768 assert(kt != NULL, "TypeKlassPtr required.");
769 ciKlass* cik = kt->klass();
770 PointsToNode::EscapeState es = PointsToNode::NoEscape;
771 bool scalar_replaceable = true;
772 if (call->is_AllocateArray()) {
773 if (!cik->is_array_klass()) { // StressReflectiveCode
774 es = PointsToNode::GlobalEscape;
775 } else {
776 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
777 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
778 // Not scalar replaceable if the length is not constant or too big.
779 scalar_replaceable = false;
780 }
781 }
782 } else { // Allocate instance
783 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
784 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
785 !cik->is_instance_klass() || // StressReflectiveCode
786 cik->as_instance_klass()->has_finalizer()) {
787 es = PointsToNode::GlobalEscape;
788 }
789 }
790 add_java_object(call, es);
791 PointsToNode* ptn = ptnode_adr(call_idx);
792 if (!scalar_replaceable && ptn->scalar_replaceable()) {
793 ptn->set_scalar_replaceable(false);
794 }
795 } else if (call->is_CallStaticJava()) {
796 // Call nodes could be different types:
797 //
798 // 1. CallDynamicJavaNode (what happened during call is unknown):
799 //
800 // - mapped to GlobalEscape JavaObject node if oop is returned;
801 //
802 // - all oop arguments are escaping globally;
803 //
804 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
805 //
806 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
807 //
808 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
809 // - mapped to NoEscape JavaObject node if non-escaping object allocated
810 // during call is returned;
811 // - mapped to ArgEscape LocalVar node pointed to object arguments
812 // which are returned and does not escape during call;
813 //
814 // - oop arguments escaping status is defined by bytecode analysis;
815 //
816 // For a static call, we know exactly what method is being called.
817 // Use bytecode estimator to record whether the call's return value escapes.
818 ciMethod* meth = call->as_CallJava()->method();
819 if (meth == NULL) {
820 const char* name = call->as_CallStaticJava()->_name;
821 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
822 // Returns a newly allocated unescaped object.
823 add_java_object(call, PointsToNode::NoEscape);
824 ptnode_adr(call_idx)->set_scalar_replaceable(false);
825 } else if (meth->is_boxing_method()) {
826 // Returns boxing object
827 PointsToNode::EscapeState es;
828 vmIntrinsics::ID intr = meth->intrinsic_id();
829 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
830 // It does not escape if object is always allocated.
831 es = PointsToNode::NoEscape;
832 } else {
833 // It escapes globally if object could be loaded from cache.
834 es = PointsToNode::GlobalEscape;
835 }
836 add_java_object(call, es);
837 } else {
838 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
839 call_analyzer->copy_dependencies(_compile->dependencies());
840 if (call_analyzer->is_return_allocated()) {
841 // Returns a newly allocated unescaped object, simply
842 // update dependency information.
843 // Mark it as NoEscape so that objects referenced by
844 // it's fields will be marked as NoEscape at least.
845 add_java_object(call, PointsToNode::NoEscape);
846 ptnode_adr(call_idx)->set_scalar_replaceable(false);
847 } else {
848 // Determine whether any arguments are returned.
849 const TypeTuple* d = call->tf()->domain();
850 bool ret_arg = false;
851 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
852 if (d->field_at(i)->isa_ptr() != NULL &&
853 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
854 ret_arg = true;
855 break;
856 }
857 }
858 if (ret_arg) {
859 add_local_var(call, PointsToNode::ArgEscape);
860 } else {
861 // Returns unknown object.
862 map_ideal_node(call, phantom_obj);
863 }
864 }
865 }
866 } else {
867 // An other type of call, assume the worst case:
868 // returned value is unknown and globally escapes.
869 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
870 map_ideal_node(call, phantom_obj);
871 }
872 }
873
874 void ConnectionGraph::process_call_arguments(CallNode *call) {
875 bool is_arraycopy = false;
876 switch (call->Opcode()) {
877 #ifdef ASSERT
878 case Op_Allocate:
879 case Op_AllocateArray:
880 case Op_Lock:
881 case Op_Unlock:
882 assert(false, "should be done already");
883 break;
884 #endif
885 case Op_CallLeafNoFP:
886 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
887 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
888 // fall through
889 case Op_CallLeaf: {
890 // Stub calls, objects do not escape but they are not scale replaceable.
891 // Adjust escape state for outgoing arguments.
892 const TypeTuple * d = call->tf()->domain();
893 bool src_has_oops = false;
894 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
895 const Type* at = d->field_at(i);
896 Node *arg = call->in(i);
897 const Type *aat = _igvn->type(arg);
898 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
899 continue;
900 if (arg->is_AddP()) {
901 //
902 // The inline_native_clone() case when the arraycopy stub is called
903 // after the allocation before Initialize and CheckCastPP nodes.
904 // Or normal arraycopy for object arrays case.
905 //
906 // Set AddP's base (Allocate) as not scalar replaceable since
907 // pointer to the base (with offset) is passed as argument.
908 //
909 arg = get_addp_base(arg);
910 }
911 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
912 assert(arg_ptn != NULL, "should be registered");
913 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
914 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
915 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
916 aat->isa_ptr() != NULL, "expecting an Ptr");
917 bool arg_has_oops = aat->isa_oopptr() &&
918 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
919 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
920 if (i == TypeFunc::Parms) {
921 src_has_oops = arg_has_oops;
922 }
923 //
924 // src or dst could be j.l.Object when other is basic type array:
925 //
926 // arraycopy(char[],0,Object*,0,size);
927 // arraycopy(Object*,0,char[],0,size);
928 //
929 // Don't add edges in such cases.
930 //
931 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
932 arg_has_oops && (i > TypeFunc::Parms);
933 #ifdef ASSERT
934 if (!(is_arraycopy ||
935 (call->as_CallLeaf()->_name != NULL &&
936 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
937 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
938 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
939 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
940 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
941 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
942 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
943 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
944 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
945 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
946 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
947 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
948 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0)
949 ))) {
950 call->dump();
951 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
952 }
953 #endif
954 // Always process arraycopy's destination object since
955 // we need to add all possible edges to references in
956 // source object.
957 if (arg_esc >= PointsToNode::ArgEscape &&
958 !arg_is_arraycopy_dest) {
959 continue;
960 }
961 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
962 if (arg_is_arraycopy_dest) {
963 Node* src = call->in(TypeFunc::Parms);
964 if (src->is_AddP()) {
965 src = get_addp_base(src);
966 }
967 PointsToNode* src_ptn = ptnode_adr(src->_idx);
968 assert(src_ptn != NULL, "should be registered");
969 if (arg_ptn != src_ptn) {
970 // Special arraycopy edge:
971 // A destination object's field can't have the source object
972 // as base since objects escape states are not related.
973 // Only escape state of destination object's fields affects
974 // escape state of fields in source object.
975 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
976 }
977 }
978 }
979 }
980 break;
981 }
982 case Op_CallStaticJava: {
983 // For a static call, we know exactly what method is being called.
984 // Use bytecode estimator to record the call's escape affects
985 #ifdef ASSERT
986 const char* name = call->as_CallStaticJava()->_name;
987 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
988 #endif
989 ciMethod* meth = call->as_CallJava()->method();
990 if ((meth != NULL) && meth->is_boxing_method()) {
991 break; // Boxing methods do not modify any oops.
992 }
993 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
994 // fall-through if not a Java method or no analyzer information
995 if (call_analyzer != NULL) {
996 PointsToNode* call_ptn = ptnode_adr(call->_idx);
997 const TypeTuple* d = call->tf()->domain();
998 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
999 const Type* at = d->field_at(i);
1000 int k = i - TypeFunc::Parms;
1001 Node* arg = call->in(i);
1002 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1003 if (at->isa_ptr() != NULL &&
1004 call_analyzer->is_arg_returned(k)) {
1005 // The call returns arguments.
1006 if (call_ptn != NULL) { // Is call's result used?
1007 assert(call_ptn->is_LocalVar(), "node should be registered");
1008 assert(arg_ptn != NULL, "node should be registered");
1009 add_edge(call_ptn, arg_ptn);
1010 }
1011 }
1012 if (at->isa_oopptr() != NULL &&
1013 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1014 if (!call_analyzer->is_arg_stack(k)) {
1015 // The argument global escapes
1016 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1017 } else {
1018 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1019 if (!call_analyzer->is_arg_local(k)) {
1020 // The argument itself doesn't escape, but any fields might
1021 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1022 }
1023 }
1024 }
1025 }
1026 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1027 // The call returns arguments.
1028 assert(call_ptn->edge_count() > 0, "sanity");
1029 if (!call_analyzer->is_return_local()) {
1030 // Returns also unknown object.
1031 add_edge(call_ptn, phantom_obj);
1032 }
1033 }
1034 break;
1035 }
1036 }
1037 default: {
1038 // Fall-through here if not a Java method or no analyzer information
1039 // or some other type of call, assume the worst case: all arguments
1040 // globally escape.
1041 const TypeTuple* d = call->tf()->domain();
1042 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1043 const Type* at = d->field_at(i);
1044 if (at->isa_oopptr() != NULL) {
1045 Node* arg = call->in(i);
1046 if (arg->is_AddP()) {
1047 arg = get_addp_base(arg);
1048 }
1049 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1050 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1051 }
1052 }
1053 }
1054 }
1055 }
1056
1057
1058 // Finish Graph construction.
1059 bool ConnectionGraph::complete_connection_graph(
1060 GrowableArray<PointsToNode*>& ptnodes_worklist,
1061 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1062 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1063 GrowableArray<FieldNode*>& oop_fields_worklist) {
1064 // Normally only 1-3 passes needed to build Connection Graph depending
1065 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1066 // Set limit to 20 to catch situation when something did go wrong and
1067 // bailout Escape Analysis.
1068 // Also limit build time to 30 sec (60 in debug VM).
1069 #define CG_BUILD_ITER_LIMIT 20
1070 #ifdef ASSERT
1071 #define CG_BUILD_TIME_LIMIT 60.0
1072 #else
1073 #define CG_BUILD_TIME_LIMIT 30.0
1074 #endif
1075
1076 // Propagate GlobalEscape and ArgEscape escape states and check that
1077 // we still have non-escaping objects. The method pushs on _worklist
1078 // Field nodes which reference phantom_object.
1079 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1080 return false; // Nothing to do.
1081 }
1082 // Now propagate references to all JavaObject nodes.
1083 int java_objects_length = java_objects_worklist.length();
1084 elapsedTimer time;
1085 int new_edges = 1;
1086 int iterations = 0;
1087 do {
1088 while ((new_edges > 0) &&
1089 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1090 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1091 time.start();
1092 new_edges = 0;
1093 // Propagate references to phantom_object for nodes pushed on _worklist
1094 // by find_non_escaped_objects() and find_field_value().
1095 new_edges += add_java_object_edges(phantom_obj, false);
1096 for (int next = 0; next < java_objects_length; ++next) {
1097 JavaObjectNode* ptn = java_objects_worklist.at(next);
1098 new_edges += add_java_object_edges(ptn, true);
1099 }
1100 if (new_edges > 0) {
1101 // Update escape states on each iteration if graph was updated.
1102 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1103 return false; // Nothing to do.
1104 }
1105 }
1106 time.stop();
1107 }
1108 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1109 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1110 time.start();
1111 // Find fields which have unknown value.
1112 int fields_length = oop_fields_worklist.length();
1113 for (int next = 0; next < fields_length; next++) {
1114 FieldNode* field = oop_fields_worklist.at(next);
1115 if (field->edge_count() == 0) {
1116 new_edges += find_field_value(field);
1117 // This code may added new edges to phantom_object.
1118 // Need an other cycle to propagate references to phantom_object.
1119 }
1120 }
1121 time.stop();
1122 } else {
1123 new_edges = 0; // Bailout
1124 }
1125 } while (new_edges > 0);
1126
1127 // Bailout if passed limits.
1128 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1129 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1130 Compile* C = _compile;
1131 if (C->log() != NULL) {
1132 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1133 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1134 C->log()->end_elem(" limit'");
1135 }
1136 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1137 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1138 // Possible infinite build_connection_graph loop,
1139 // bailout (no changes to ideal graph were made).
1140 return false;
1141 }
1142 #ifdef ASSERT
1143 if (Verbose && PrintEscapeAnalysis) {
1144 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1145 iterations, nodes_size(), ptnodes_worklist.length());
1146 }
1147 #endif
1148
1149 #undef CG_BUILD_ITER_LIMIT
1150 #undef CG_BUILD_TIME_LIMIT
1151
1152 // Find fields initialized by NULL for non-escaping Allocations.
1153 int non_escaped_length = non_escaped_worklist.length();
1154 for (int next = 0; next < non_escaped_length; next++) {
1155 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1156 PointsToNode::EscapeState es = ptn->escape_state();
1157 assert(es <= PointsToNode::ArgEscape, "sanity");
1158 if (es == PointsToNode::NoEscape) {
1159 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1160 // Adding references to NULL object does not change escape states
1161 // since it does not escape. Also no fields are added to NULL object.
1162 add_java_object_edges(null_obj, false);
1163 }
1164 }
1165 Node* n = ptn->ideal_node();
1166 if (n->is_Allocate()) {
1167 // The object allocated by this Allocate node will never be
1168 // seen by an other thread. Mark it so that when it is
1169 // expanded no MemBarStoreStore is added.
1170 InitializeNode* ini = n->as_Allocate()->initialization();
1171 if (ini != NULL)
1172 ini->set_does_not_escape();
1173 }
1174 }
1175 return true; // Finished graph construction.
1176 }
1177
1178 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1179 // and check that we still have non-escaping java objects.
1180 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1181 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1182 GrowableArray<PointsToNode*> escape_worklist;
1183 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1184 int ptnodes_length = ptnodes_worklist.length();
1185 for (int next = 0; next < ptnodes_length; ++next) {
1186 PointsToNode* ptn = ptnodes_worklist.at(next);
1187 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1188 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1189 escape_worklist.push(ptn);
1190 }
1191 }
1192 // Set escape states to referenced nodes (edges list).
1193 while (escape_worklist.length() > 0) {
1194 PointsToNode* ptn = escape_worklist.pop();
1195 PointsToNode::EscapeState es = ptn->escape_state();
1196 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1197 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1198 es >= PointsToNode::ArgEscape) {
1199 // GlobalEscape or ArgEscape state of field means it has unknown value.
1200 if (add_edge(ptn, phantom_obj)) {
1201 // New edge was added
1202 add_field_uses_to_worklist(ptn->as_Field());
1203 }
1204 }
1205 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1206 PointsToNode* e = i.get();
1207 if (e->is_Arraycopy()) {
1208 assert(ptn->arraycopy_dst(), "sanity");
1209 // Propagate only fields escape state through arraycopy edge.
1210 if (e->fields_escape_state() < field_es) {
1211 set_fields_escape_state(e, field_es);
1212 escape_worklist.push(e);
1213 }
1214 } else if (es >= field_es) {
1215 // fields_escape_state is also set to 'es' if it is less than 'es'.
1216 if (e->escape_state() < es) {
1217 set_escape_state(e, es);
1218 escape_worklist.push(e);
1219 }
1220 } else {
1221 // Propagate field escape state.
1222 bool es_changed = false;
1223 if (e->fields_escape_state() < field_es) {
1224 set_fields_escape_state(e, field_es);
1225 es_changed = true;
1226 }
1227 if ((e->escape_state() < field_es) &&
1228 e->is_Field() && ptn->is_JavaObject() &&
1229 e->as_Field()->is_oop()) {
1230 // Change escape state of referenced fileds.
1231 set_escape_state(e, field_es);
1232 es_changed = true;;
1233 } else if (e->escape_state() < es) {
1234 set_escape_state(e, es);
1235 es_changed = true;;
1236 }
1237 if (es_changed) {
1238 escape_worklist.push(e);
1239 }
1240 }
1241 }
1242 }
1243 // Remove escaped objects from non_escaped list.
1244 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1245 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1246 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1247 non_escaped_worklist.delete_at(next);
1248 }
1249 if (ptn->escape_state() == PointsToNode::NoEscape) {
1250 // Find fields in non-escaped allocations which have unknown value.
1251 find_init_values(ptn, phantom_obj, NULL);
1252 }
1253 }
1254 return (non_escaped_worklist.length() > 0);
1255 }
1256
1257 // Add all references to JavaObject node by walking over all uses.
1258 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1259 int new_edges = 0;
1260 if (populate_worklist) {
1261 // Populate _worklist by uses of jobj's uses.
1262 for (UseIterator i(jobj); i.has_next(); i.next()) {
1263 PointsToNode* use = i.get();
1264 if (use->is_Arraycopy())
1265 continue;
1266 add_uses_to_worklist(use);
1267 if (use->is_Field() && use->as_Field()->is_oop()) {
1268 // Put on worklist all field's uses (loads) and
1269 // related field nodes (same base and offset).
1270 add_field_uses_to_worklist(use->as_Field());
1271 }
1272 }
1273 }
1274 while(_worklist.length() > 0) {
1275 PointsToNode* use = _worklist.pop();
1276 if (PointsToNode::is_base_use(use)) {
1277 // Add reference from jobj to field and from field to jobj (field's base).
1278 use = PointsToNode::get_use_node(use)->as_Field();
1279 if (add_base(use->as_Field(), jobj)) {
1280 new_edges++;
1281 }
1282 continue;
1283 }
1284 assert(!use->is_JavaObject(), "sanity");
1285 if (use->is_Arraycopy()) {
1286 if (jobj == null_obj) // NULL object does not have field edges
1287 continue;
1288 // Added edge from Arraycopy node to arraycopy's source java object
1289 if (add_edge(use, jobj)) {
1290 jobj->set_arraycopy_src();
1291 new_edges++;
1292 }
1293 // and stop here.
1294 continue;
1295 }
1296 if (!add_edge(use, jobj))
1297 continue; // No new edge added, there was such edge already.
1298 new_edges++;
1299 if (use->is_LocalVar()) {
1300 add_uses_to_worklist(use);
1301 if (use->arraycopy_dst()) {
1302 for (EdgeIterator i(use); i.has_next(); i.next()) {
1303 PointsToNode* e = i.get();
1304 if (e->is_Arraycopy()) {
1305 if (jobj == null_obj) // NULL object does not have field edges
1306 continue;
1307 // Add edge from arraycopy's destination java object to Arraycopy node.
1308 if (add_edge(jobj, e)) {
1309 new_edges++;
1310 jobj->set_arraycopy_dst();
1311 }
1312 }
1313 }
1314 }
1315 } else {
1316 // Added new edge to stored in field values.
1317 // Put on worklist all field's uses (loads) and
1318 // related field nodes (same base and offset).
1319 add_field_uses_to_worklist(use->as_Field());
1320 }
1321 }
1322 return new_edges;
1323 }
1324
1325 // Put on worklist all related field nodes.
1326 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1327 assert(field->is_oop(), "sanity");
1328 int offset = field->offset();
1329 add_uses_to_worklist(field);
1330 // Loop over all bases of this field and push on worklist Field nodes
1331 // with the same offset and base (since they may reference the same field).
1332 for (BaseIterator i(field); i.has_next(); i.next()) {
1333 PointsToNode* base = i.get();
1334 add_fields_to_worklist(field, base);
1335 // Check if the base was source object of arraycopy and go over arraycopy's
1336 // destination objects since values stored to a field of source object are
1337 // accessable by uses (loads) of fields of destination objects.
1338 if (base->arraycopy_src()) {
1339 for (UseIterator j(base); j.has_next(); j.next()) {
1340 PointsToNode* arycp = j.get();
1341 if (arycp->is_Arraycopy()) {
1342 for (UseIterator k(arycp); k.has_next(); k.next()) {
1343 PointsToNode* abase = k.get();
1344 if (abase->arraycopy_dst() && abase != base) {
1345 // Look for the same arracopy reference.
1346 add_fields_to_worklist(field, abase);
1347 }
1348 }
1349 }
1350 }
1351 }
1352 }
1353 }
1354
1355 // Put on worklist all related field nodes.
1356 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1357 int offset = field->offset();
1358 if (base->is_LocalVar()) {
1359 for (UseIterator j(base); j.has_next(); j.next()) {
1360 PointsToNode* f = j.get();
1361 if (PointsToNode::is_base_use(f)) { // Field
1362 f = PointsToNode::get_use_node(f);
1363 if (f == field || !f->as_Field()->is_oop())
1364 continue;
1365 int offs = f->as_Field()->offset();
1366 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1367 add_to_worklist(f);
1368 }
1369 }
1370 }
1371 } else {
1372 assert(base->is_JavaObject(), "sanity");
1373 if (// Skip phantom_object since it is only used to indicate that
1374 // this field's content globally escapes.
1375 (base != phantom_obj) &&
1376 // NULL object node does not have fields.
1377 (base != null_obj)) {
1378 for (EdgeIterator i(base); i.has_next(); i.next()) {
1379 PointsToNode* f = i.get();
1380 // Skip arraycopy edge since store to destination object field
1381 // does not update value in source object field.
1382 if (f->is_Arraycopy()) {
1383 assert(base->arraycopy_dst(), "sanity");
1384 continue;
1385 }
1386 if (f == field || !f->as_Field()->is_oop())
1387 continue;
1388 int offs = f->as_Field()->offset();
1389 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1390 add_to_worklist(f);
1391 }
1392 }
1393 }
1394 }
1395 }
1396
1397 // Find fields which have unknown value.
1398 int ConnectionGraph::find_field_value(FieldNode* field) {
1399 // Escaped fields should have init value already.
1400 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1401 int new_edges = 0;
1402 for (BaseIterator i(field); i.has_next(); i.next()) {
1403 PointsToNode* base = i.get();
1404 if (base->is_JavaObject()) {
1405 // Skip Allocate's fields which will be processed later.
1406 if (base->ideal_node()->is_Allocate())
1407 return 0;
1408 assert(base == null_obj, "only NULL ptr base expected here");
1409 }
1410 }
1411 if (add_edge(field, phantom_obj)) {
1412 // New edge was added
1413 new_edges++;
1414 add_field_uses_to_worklist(field);
1415 }
1416 return new_edges;
1417 }
1418
1419 // Find fields initializing values for allocations.
1420 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1421 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1422 int new_edges = 0;
1423 Node* alloc = pta->ideal_node();
1424 if (init_val == phantom_obj) {
1425 // Do nothing for Allocate nodes since its fields values are "known".
1426 if (alloc->is_Allocate())
1427 return 0;
1428 assert(alloc->as_CallStaticJava(), "sanity");
1429 #ifdef ASSERT
1430 if (alloc->as_CallStaticJava()->method() == NULL) {
1431 const char* name = alloc->as_CallStaticJava()->_name;
1432 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1433 }
1434 #endif
1435 // Non-escaped allocation returned from Java or runtime call have
1436 // unknown values in fields.
1437 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1438 PointsToNode* field = i.get();
1439 if (field->is_Field() && field->as_Field()->is_oop()) {
1440 if (add_edge(field, phantom_obj)) {
1441 // New edge was added
1442 new_edges++;
1443 add_field_uses_to_worklist(field->as_Field());
1444 }
1445 }
1446 }
1447 return new_edges;
1448 }
1449 assert(init_val == null_obj, "sanity");
1450 // Do nothing for Call nodes since its fields values are unknown.
1451 if (!alloc->is_Allocate())
1452 return 0;
1453
1454 InitializeNode* ini = alloc->as_Allocate()->initialization();
1455 bool visited_bottom_offset = false;
1456 GrowableArray<int> offsets_worklist;
1457
1458 // Check if an oop field's initializing value is recorded and add
1459 // a corresponding NULL if field's value if it is not recorded.
1460 // Connection Graph does not record a default initialization by NULL
1461 // captured by Initialize node.
1462 //
1463 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1464 PointsToNode* field = i.get(); // Field (AddP)
1465 if (!field->is_Field() || !field->as_Field()->is_oop())
1466 continue; // Not oop field
1467 int offset = field->as_Field()->offset();
1468 if (offset == Type::OffsetBot) {
1469 if (!visited_bottom_offset) {
1470 // OffsetBot is used to reference array's element,
1471 // always add reference to NULL to all Field nodes since we don't
1472 // known which element is referenced.
1473 if (add_edge(field, null_obj)) {
1474 // New edge was added
1475 new_edges++;
1476 add_field_uses_to_worklist(field->as_Field());
1477 visited_bottom_offset = true;
1478 }
1479 }
1480 } else {
1481 // Check only oop fields.
1482 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1483 if (adr_type->isa_rawptr()) {
1484 #ifdef ASSERT
1485 // Raw pointers are used for initializing stores so skip it
1486 // since it should be recorded already
1487 Node* base = get_addp_base(field->ideal_node());
1488 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1489 (base->in(0) == alloc),"unexpected pointer type");
1490 #endif
1491 continue;
1492 }
1493 if (!offsets_worklist.contains(offset)) {
1494 offsets_worklist.append(offset);
1495 Node* value = NULL;
1496 if (ini != NULL) {
1497 // StoreP::memory_type() == T_ADDRESS
1498 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1499 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1500 // Make sure initializing store has the same type as this AddP.
1501 // This AddP may reference non existing field because it is on a
1502 // dead branch of bimorphic call which is not eliminated yet.
1503 if (store != NULL && store->is_Store() &&
1504 store->as_Store()->memory_type() == ft) {
1505 value = store->in(MemNode::ValueIn);
1506 #ifdef ASSERT
1507 if (VerifyConnectionGraph) {
1508 // Verify that AddP already points to all objects the value points to.
1509 PointsToNode* val = ptnode_adr(value->_idx);
1510 assert((val != NULL), "should be processed already");
1511 PointsToNode* missed_obj = NULL;
1512 if (val->is_JavaObject()) {
1513 if (!field->points_to(val->as_JavaObject())) {
1514 missed_obj = val;
1515 }
1516 } else {
1517 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1518 tty->print_cr("----------init store has invalid value -----");
1519 store->dump();
1520 val->dump();
1521 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1522 }
1523 for (EdgeIterator j(val); j.has_next(); j.next()) {
1524 PointsToNode* obj = j.get();
1525 if (obj->is_JavaObject()) {
1526 if (!field->points_to(obj->as_JavaObject())) {
1527 missed_obj = obj;
1528 break;
1529 }
1530 }
1531 }
1532 }
1533 if (missed_obj != NULL) {
1534 tty->print_cr("----------field---------------------------------");
1535 field->dump();
1536 tty->print_cr("----------missed referernce to object-----------");
1537 missed_obj->dump();
1538 tty->print_cr("----------object referernced by init store -----");
1539 store->dump();
1540 val->dump();
1541 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1542 }
1543 }
1544 #endif
1545 } else {
1546 // There could be initializing stores which follow allocation.
1547 // For example, a volatile field store is not collected
1548 // by Initialize node.
1549 //
1550 // Need to check for dependent loads to separate such stores from
1551 // stores which follow loads. For now, add initial value NULL so
1552 // that compare pointers optimization works correctly.
1553 }
1554 }
1555 if (value == NULL) {
1556 // A field's initializing value was not recorded. Add NULL.
1557 if (add_edge(field, null_obj)) {
1558 // New edge was added
1559 new_edges++;
1560 add_field_uses_to_worklist(field->as_Field());
1561 }
1562 }
1563 }
1564 }
1565 }
1566 return new_edges;
1567 }
1568
1569 // Adjust scalar_replaceable state after Connection Graph is built.
1570 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1571 // Search for non-escaping objects which are not scalar replaceable
1572 // and mark them to propagate the state to referenced objects.
1573
1574 // 1. An object is not scalar replaceable if the field into which it is
1575 // stored has unknown offset (stored into unknown element of an array).
1576 //
1577 for (UseIterator i(jobj); i.has_next(); i.next()) {
1578 PointsToNode* use = i.get();
1579 assert(!use->is_Arraycopy(), "sanity");
1580 if (use->is_Field()) {
1581 FieldNode* field = use->as_Field();
1582 assert(field->is_oop() && field->scalar_replaceable() &&
1583 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1584 if (field->offset() == Type::OffsetBot) {
1585 jobj->set_scalar_replaceable(false);
1586 return;
1587 }
1588 // 2. An object is not scalar replaceable if the field into which it is
1589 // stored has multiple bases one of which is null.
1590 if (field->base_count() > 1) {
1591 for (BaseIterator i(field); i.has_next(); i.next()) {
1592 PointsToNode* base = i.get();
1593 if (base == null_obj) {
1594 jobj->set_scalar_replaceable(false);
1595 return;
1596 }
1597 }
1598 }
1599 }
1600 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1601 // 3. An object is not scalar replaceable if it is merged with other objects.
1602 for (EdgeIterator j(use); j.has_next(); j.next()) {
1603 PointsToNode* ptn = j.get();
1604 if (ptn->is_JavaObject() && ptn != jobj) {
1605 // Mark all objects.
1606 jobj->set_scalar_replaceable(false);
1607 ptn->set_scalar_replaceable(false);
1608 }
1609 }
1610 if (!jobj->scalar_replaceable()) {
1611 return;
1612 }
1613 }
1614
1615 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1616 // Non-escaping object node should point only to field nodes.
1617 FieldNode* field = j.get()->as_Field();
1618 int offset = field->as_Field()->offset();
1619
1620 // 4. An object is not scalar replaceable if it has a field with unknown
1621 // offset (array's element is accessed in loop).
1622 if (offset == Type::OffsetBot) {
1623 jobj->set_scalar_replaceable(false);
1624 return;
1625 }
1626 // 5. Currently an object is not scalar replaceable if a LoadStore node
1627 // access its field since the field value is unknown after it.
1628 //
1629 Node* n = field->ideal_node();
1630 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1631 if (n->fast_out(i)->is_LoadStore()) {
1632 jobj->set_scalar_replaceable(false);
1633 return;
1634 }
1635 }
1636
1637 // 6. Or the address may point to more then one object. This may produce
1638 // the false positive result (set not scalar replaceable)
1639 // since the flow-insensitive escape analysis can't separate
1640 // the case when stores overwrite the field's value from the case
1641 // when stores happened on different control branches.
1642 //
1643 // Note: it will disable scalar replacement in some cases:
1644 //
1645 // Point p[] = new Point[1];
1646 // p[0] = new Point(); // Will be not scalar replaced
1647 //
1648 // but it will save us from incorrect optimizations in next cases:
1649 //
1650 // Point p[] = new Point[1];
1651 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1652 //
1653 if (field->base_count() > 1) {
1654 for (BaseIterator i(field); i.has_next(); i.next()) {
1655 PointsToNode* base = i.get();
1656 // Don't take into account LocalVar nodes which
1657 // may point to only one object which should be also
1658 // this field's base by now.
1659 if (base->is_JavaObject() && base != jobj) {
1660 // Mark all bases.
1661 jobj->set_scalar_replaceable(false);
1662 base->set_scalar_replaceable(false);
1663 }
1664 }
1665 }
1666 }
1667 }
1668
1669 #ifdef ASSERT
1670 void ConnectionGraph::verify_connection_graph(
1671 GrowableArray<PointsToNode*>& ptnodes_worklist,
1672 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1673 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1674 GrowableArray<Node*>& addp_worklist) {
1675 // Verify that graph is complete - no new edges could be added.
1676 int java_objects_length = java_objects_worklist.length();
1677 int non_escaped_length = non_escaped_worklist.length();
1678 int new_edges = 0;
1679 for (int next = 0; next < java_objects_length; ++next) {
1680 JavaObjectNode* ptn = java_objects_worklist.at(next);
1681 new_edges += add_java_object_edges(ptn, true);
1682 }
1683 assert(new_edges == 0, "graph was not complete");
1684 // Verify that escape state is final.
1685 int length = non_escaped_worklist.length();
1686 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1687 assert((non_escaped_length == non_escaped_worklist.length()) &&
1688 (non_escaped_length == length) &&
1689 (_worklist.length() == 0), "escape state was not final");
1690
1691 // Verify fields information.
1692 int addp_length = addp_worklist.length();
1693 for (int next = 0; next < addp_length; ++next ) {
1694 Node* n = addp_worklist.at(next);
1695 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1696 if (field->is_oop()) {
1697 // Verify that field has all bases
1698 Node* base = get_addp_base(n);
1699 PointsToNode* ptn = ptnode_adr(base->_idx);
1700 if (ptn->is_JavaObject()) {
1701 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1702 } else {
1703 assert(ptn->is_LocalVar(), "sanity");
1704 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1705 PointsToNode* e = i.get();
1706 if (e->is_JavaObject()) {
1707 assert(field->has_base(e->as_JavaObject()), "sanity");
1708 }
1709 }
1710 }
1711 // Verify that all fields have initializing values.
1712 if (field->edge_count() == 0) {
1713 tty->print_cr("----------field does not have references----------");
1714 field->dump();
1715 for (BaseIterator i(field); i.has_next(); i.next()) {
1716 PointsToNode* base = i.get();
1717 tty->print_cr("----------field has next base---------------------");
1718 base->dump();
1719 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1720 tty->print_cr("----------base has fields-------------------------");
1721 for (EdgeIterator j(base); j.has_next(); j.next()) {
1722 j.get()->dump();
1723 }
1724 tty->print_cr("----------base has references---------------------");
1725 for (UseIterator j(base); j.has_next(); j.next()) {
1726 j.get()->dump();
1727 }
1728 }
1729 }
1730 for (UseIterator i(field); i.has_next(); i.next()) {
1731 i.get()->dump();
1732 }
1733 assert(field->edge_count() > 0, "sanity");
1734 }
1735 }
1736 }
1737 }
1738 #endif
1739
1740 // Optimize ideal graph.
1741 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1742 GrowableArray<Node*>& storestore_worklist) {
1743 Compile* C = _compile;
1744 PhaseIterGVN* igvn = _igvn;
1745 if (EliminateLocks) {
1746 // Mark locks before changing ideal graph.
1747 int cnt = C->macro_count();
1748 for( int i=0; i < cnt; i++ ) {
1749 Node *n = C->macro_node(i);
1750 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1751 AbstractLockNode* alock = n->as_AbstractLock();
1752 if (!alock->is_non_esc_obj()) {
1753 if (not_global_escape(alock->obj_node())) {
1754 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1755 // The lock could be marked eliminated by lock coarsening
1756 // code during first IGVN before EA. Replace coarsened flag
1757 // to eliminate all associated locks/unlocks.
1758 alock->set_non_esc_obj();
1759 }
1760 }
1761 }
1762 }
1763 }
1764
1765 if (OptimizePtrCompare) {
1766 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1767 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1768 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1769 // Optimize objects compare.
1770 while (ptr_cmp_worklist.length() != 0) {
1771 Node *n = ptr_cmp_worklist.pop();
1772 Node *res = optimize_ptr_compare(n);
1773 if (res != NULL) {
1774 #ifndef PRODUCT
1775 if (PrintOptimizePtrCompare) {
1776 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"));
1777 if (Verbose) {
1778 n->dump(1);
1779 }
1780 }
1781 #endif
1782 igvn->replace_node(n, res);
1783 }
1784 }
1785 // cleanup
1786 if (_pcmp_neq->outcnt() == 0)
1787 igvn->hash_delete(_pcmp_neq);
1788 if (_pcmp_eq->outcnt() == 0)
1789 igvn->hash_delete(_pcmp_eq);
1790 }
1791
1792 // For MemBarStoreStore nodes added in library_call.cpp, check
1793 // escape status of associated AllocateNode and optimize out
1794 // MemBarStoreStore node if the allocated object never escapes.
1795 while (storestore_worklist.length() != 0) {
1796 Node *n = storestore_worklist.pop();
1797 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1798 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1799 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1800 if (not_global_escape(alloc)) {
1801 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1802 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1803 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1804 igvn->register_new_node_with_optimizer(mb);
1805 igvn->replace_node(storestore, mb);
1806 }
1807 }
1808 }
1809
1810 // Optimize objects compare.
1811 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1812 assert(OptimizePtrCompare, "sanity");
1813 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1814 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1815 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1816 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1817 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1818 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1819
1820 // Check simple cases first.
1821 if (jobj1 != NULL) {
1822 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1823 if (jobj1 == jobj2) {
1824 // Comparing the same not escaping object.
1825 return _pcmp_eq;
1826 }
1827 Node* obj = jobj1->ideal_node();
1828 // Comparing not escaping allocation.
1829 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1830 !ptn2->points_to(jobj1)) {
1831 return _pcmp_neq; // This includes nullness check.
1832 }
1833 }
1834 }
1835 if (jobj2 != NULL) {
1836 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1837 Node* obj = jobj2->ideal_node();
1838 // Comparing not escaping allocation.
1839 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1840 !ptn1->points_to(jobj2)) {
1841 return _pcmp_neq; // This includes nullness check.
1842 }
1843 }
1844 }
1845 if (jobj1 != NULL && jobj1 != phantom_obj &&
1846 jobj2 != NULL && jobj2 != phantom_obj &&
1847 jobj1->ideal_node()->is_Con() &&
1848 jobj2->ideal_node()->is_Con()) {
1849 // Klass or String constants compare. Need to be careful with
1850 // compressed pointers - compare types of ConN and ConP instead of nodes.
1851 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1852 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1853 if (t1->make_ptr() == t2->make_ptr()) {
1854 return _pcmp_eq;
1855 } else {
1856 return _pcmp_neq;
1857 }
1858 }
1859 if (ptn1->meet(ptn2)) {
1860 return NULL; // Sets are not disjoint
1861 }
1862
1863 // Sets are disjoint.
1864 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1865 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1866 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1867 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1868 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1869 set2_has_unknown_ptr && set1_has_null_ptr) {
1870 // Check nullness of unknown object.
1871 return NULL;
1872 }
1873
1874 // Disjointness by itself is not sufficient since
1875 // alias analysis is not complete for escaped objects.
1876 // Disjoint sets are definitely unrelated only when
1877 // at least one set has only not escaping allocations.
1878 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1879 if (ptn1->non_escaping_allocation()) {
1880 return _pcmp_neq;
1881 }
1882 }
1883 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1884 if (ptn2->non_escaping_allocation()) {
1885 return _pcmp_neq;
1886 }
1887 }
1888 return NULL;
1889 }
1890
1891 // Connection Graph constuction functions.
1892
1893 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1894 PointsToNode* ptadr = _nodes.at(n->_idx);
1895 if (ptadr != NULL) {
1896 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1897 return;
1898 }
1899 Compile* C = _compile;
1900 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1901 _nodes.at_put(n->_idx, ptadr);
1902 }
1903
1904 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1905 PointsToNode* ptadr = _nodes.at(n->_idx);
1906 if (ptadr != NULL) {
1907 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1908 return;
1909 }
1910 Compile* C = _compile;
1911 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1912 _nodes.at_put(n->_idx, ptadr);
1913 }
1914
1915 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1916 PointsToNode* ptadr = _nodes.at(n->_idx);
1917 if (ptadr != NULL) {
1918 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1919 return;
1920 }
1921 bool unsafe = false;
1922 bool is_oop = is_oop_field(n, offset, &unsafe);
1923 if (unsafe) {
1924 es = PointsToNode::GlobalEscape;
1925 }
1926 Compile* C = _compile;
1927 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1928 _nodes.at_put(n->_idx, field);
1929 }
1930
1931 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1932 PointsToNode* src, PointsToNode* dst) {
1933 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1934 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1935 PointsToNode* ptadr = _nodes.at(n->_idx);
1936 if (ptadr != NULL) {
1937 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1938 return;
1939 }
1940 Compile* C = _compile;
1941 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1942 _nodes.at_put(n->_idx, ptadr);
1943 // Add edge from arraycopy node to source object.
1944 (void)add_edge(ptadr, src);
1945 src->set_arraycopy_src();
1946 // Add edge from destination object to arraycopy node.
1947 (void)add_edge(dst, ptadr);
1948 dst->set_arraycopy_dst();
1949 }
1950
1951 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1952 const Type* adr_type = n->as_AddP()->bottom_type();
1953 BasicType bt = T_INT;
1954 if (offset == Type::OffsetBot) {
1955 // Check only oop fields.
1956 if (!adr_type->isa_aryptr() ||
1957 (adr_type->isa_aryptr()->klass() == NULL) ||
1958 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1959 // OffsetBot is used to reference array's element. Ignore first AddP.
1960 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1961 bt = T_OBJECT;
1962 }
1963 }
1964 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1965 if (adr_type->isa_instptr()) {
1966 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1967 if (field != NULL) {
1968 bt = field->layout_type();
1969 } else {
1970 // Check for unsafe oop field access
1971 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1972 int opcode = n->fast_out(i)->Opcode();
1973 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1974 opcode == Op_StoreN || opcode == Op_LoadN) {
1975 bt = T_OBJECT;
1976 (*unsafe) = true;
1977 break;
1978 }
1979 }
1980 }
1981 } else if (adr_type->isa_aryptr()) {
1982 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1983 // Ignore array length load.
1984 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1985 // Ignore first AddP.
1986 } else {
1987 const Type* elemtype = adr_type->isa_aryptr()->elem();
1988 bt = elemtype->array_element_basic_type();
1989 }
1990 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1991 // Allocation initialization, ThreadLocal field access, unsafe access
1992 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1993 int opcode = n->fast_out(i)->Opcode();
1994 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1995 opcode == Op_StoreN || opcode == Op_LoadN) {
1996 bt = T_OBJECT;
1997 break;
1998 }
1999 }
2000 }
2001 }
2002 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2003 }
2004
2005 // Returns unique pointed java object or NULL.
2006 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2007 assert(!_collecting, "should not call when contructed graph");
2008 // If the node was created after the escape computation we can't answer.
2009 uint idx = n->_idx;
2010 if (idx >= nodes_size()) {
2011 return NULL;
2012 }
2013 PointsToNode* ptn = ptnode_adr(idx);
2014 if (ptn->is_JavaObject()) {
2015 return ptn->as_JavaObject();
2016 }
2017 assert(ptn->is_LocalVar(), "sanity");
2018 // Check all java objects it points to.
2019 JavaObjectNode* jobj = NULL;
2020 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2021 PointsToNode* e = i.get();
2022 if (e->is_JavaObject()) {
2023 if (jobj == NULL) {
2024 jobj = e->as_JavaObject();
2025 } else if (jobj != e) {
2026 return NULL;
2027 }
2028 }
2029 }
2030 return jobj;
2031 }
2032
2033 // Return true if this node points only to non-escaping allocations.
2034 bool PointsToNode::non_escaping_allocation() {
2035 if (is_JavaObject()) {
2036 Node* n = ideal_node();
2037 if (n->is_Allocate() || n->is_CallStaticJava()) {
2038 return (escape_state() == PointsToNode::NoEscape);
2039 } else {
2040 return false;
2041 }
2042 }
2043 assert(is_LocalVar(), "sanity");
2044 // Check all java objects it points to.
2045 for (EdgeIterator i(this); i.has_next(); i.next()) {
2046 PointsToNode* e = i.get();
2047 if (e->is_JavaObject()) {
2048 Node* n = e->ideal_node();
2049 if ((e->escape_state() != PointsToNode::NoEscape) ||
2050 !(n->is_Allocate() || n->is_CallStaticJava())) {
2051 return false;
2052 }
2053 }
2054 }
2055 return true;
2056 }
2057
2058 // Return true if we know the node does not escape globally.
2059 bool ConnectionGraph::not_global_escape(Node *n) {
2060 assert(!_collecting, "should not call during graph construction");
2061 // If the node was created after the escape computation we can't answer.
2062 uint idx = n->_idx;
2063 if (idx >= nodes_size()) {
2064 return false;
2065 }
2066 PointsToNode* ptn = ptnode_adr(idx);
2067 PointsToNode::EscapeState es = ptn->escape_state();
2068 // If we have already computed a value, return it.
2069 if (es >= PointsToNode::GlobalEscape)
2070 return false;
2071 if (ptn->is_JavaObject()) {
2072 return true; // (es < PointsToNode::GlobalEscape);
2073 }
2074 assert(ptn->is_LocalVar(), "sanity");
2075 // Check all java objects it points to.
2076 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2077 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2078 return false;
2079 }
2080 return true;
2081 }
2082
2083
2084 // Helper functions
2085
2086 // Return true if this node points to specified node or nodes it points to.
2087 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2088 if (is_JavaObject()) {
2089 return (this == ptn);
2090 }
2091 assert(is_LocalVar() || is_Field(), "sanity");
2092 for (EdgeIterator i(this); i.has_next(); i.next()) {
2093 if (i.get() == ptn)
2094 return true;
2095 }
2096 return false;
2097 }
2098
2099 // Return true if one node points to an other.
2100 bool PointsToNode::meet(PointsToNode* ptn) {
2101 if (this == ptn) {
2102 return true;
2103 } else if (ptn->is_JavaObject()) {
2104 return this->points_to(ptn->as_JavaObject());
2105 } else if (this->is_JavaObject()) {
2106 return ptn->points_to(this->as_JavaObject());
2107 }
2108 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2109 int ptn_count = ptn->edge_count();
2110 for (EdgeIterator i(this); i.has_next(); i.next()) {
2111 PointsToNode* this_e = i.get();
2112 for (int j = 0; j < ptn_count; j++) {
2113 if (this_e == ptn->edge(j))
2114 return true;
2115 }
2116 }
2117 return false;
2118 }
2119
2120 #ifdef ASSERT
2121 // Return true if bases point to this java object.
2122 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2123 for (BaseIterator i(this); i.has_next(); i.next()) {
2124 if (i.get() == jobj)
2125 return true;
2126 }
2127 return false;
2128 }
2129 #endif
2130
2131 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2132 const Type *adr_type = phase->type(adr);
2133 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2134 adr->in(AddPNode::Address)->is_Proj() &&
2135 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2136 // We are computing a raw address for a store captured by an Initialize
2137 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2138 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2139 assert(offs != Type::OffsetBot ||
2140 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2141 "offset must be a constant or it is initialization of array");
2142 return offs;
2143 }
2144 const TypePtr *t_ptr = adr_type->isa_ptr();
2145 assert(t_ptr != NULL, "must be a pointer type");
2146 return t_ptr->offset();
2147 }
2148
2149 Node* ConnectionGraph::get_addp_base(Node *addp) {
2150 assert(addp->is_AddP(), "must be AddP");
2151 //
2152 // AddP cases for Base and Address inputs:
2153 // case #1. Direct object's field reference:
2154 // Allocate
2155 // |
2156 // Proj #5 ( oop result )
2157 // |
2158 // CheckCastPP (cast to instance type)
2159 // | |
2160 // AddP ( base == address )
2161 //
2162 // case #2. Indirect object's field reference:
2163 // Phi
2164 // |
2165 // CastPP (cast to instance type)
2166 // | |
2167 // AddP ( base == address )
2168 //
2169 // case #3. Raw object's field reference for Initialize node:
2170 // Allocate
2171 // |
2172 // Proj #5 ( oop result )
2173 // top |
2174 // \ |
2175 // AddP ( base == top )
2176 //
2177 // case #4. Array's element reference:
2178 // {CheckCastPP | CastPP}
2179 // | | |
2180 // | AddP ( array's element offset )
2181 // | |
2182 // AddP ( array's offset )
2183 //
2184 // case #5. Raw object's field reference for arraycopy stub call:
2185 // The inline_native_clone() case when the arraycopy stub is called
2186 // after the allocation before Initialize and CheckCastPP nodes.
2187 // Allocate
2188 // |
2189 // Proj #5 ( oop result )
2190 // | |
2191 // AddP ( base == address )
2192 //
2193 // case #6. Constant Pool, ThreadLocal, CastX2P or
2194 // Raw object's field reference:
2195 // {ConP, ThreadLocal, CastX2P, raw Load}
2196 // top |
2197 // \ |
2198 // AddP ( base == top )
2199 //
2200 // case #7. Klass's field reference.
2201 // LoadKlass
2202 // | |
2203 // AddP ( base == address )
2204 //
2205 // case #8. narrow Klass's field reference.
2206 // LoadNKlass
2207 // |
2208 // DecodeN
2209 // | |
2210 // AddP ( base == address )
2211 //
2212 Node *base = addp->in(AddPNode::Base);
2213 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2214 base = addp->in(AddPNode::Address);
2215 while (base->is_AddP()) {
2216 // Case #6 (unsafe access) may have several chained AddP nodes.
2217 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2218 base = base->in(AddPNode::Address);
2219 }
2220 Node* uncast_base = base->uncast();
2221 int opcode = uncast_base->Opcode();
2222 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2223 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2224 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2225 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2226 }
2227 return base;
2228 }
2229
2230 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2231 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2232 Node* addp2 = addp->raw_out(0);
2233 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2234 addp2->in(AddPNode::Base) == n &&
2235 addp2->in(AddPNode::Address) == addp) {
2236 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2237 //
2238 // Find array's offset to push it on worklist first and
2239 // as result process an array's element offset first (pushed second)
2240 // to avoid CastPP for the array's offset.
2241 // Otherwise the inserted CastPP (LocalVar) will point to what
2242 // the AddP (Field) points to. Which would be wrong since
2243 // the algorithm expects the CastPP has the same point as
2244 // as AddP's base CheckCastPP (LocalVar).
2245 //
2246 // ArrayAllocation
2247 // |
2248 // CheckCastPP
2249 // |
2250 // memProj (from ArrayAllocation CheckCastPP)
2251 // | ||
2252 // | || Int (element index)
2253 // | || | ConI (log(element size))
2254 // | || | /
2255 // | || LShift
2256 // | || /
2257 // | AddP (array's element offset)
2258 // | |
2259 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2260 // | / /
2261 // AddP (array's offset)
2262 // |
2263 // Load/Store (memory operation on array's element)
2264 //
2265 return addp2;
2266 }
2267 return NULL;
2268 }
2269
2270 //
2271 // Adjust the type and inputs of an AddP which computes the
2272 // address of a field of an instance
2273 //
2274 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2275 PhaseGVN* igvn = _igvn;
2276 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2277 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2278 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2279 if (t == NULL) {
2280 // We are computing a raw address for a store captured by an Initialize
2281 // compute an appropriate address type (cases #3 and #5).
2282 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2283 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2284 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2285 assert(offs != Type::OffsetBot, "offset must be a constant");
2286 t = base_t->add_offset(offs)->is_oopptr();
2287 }
2288 int inst_id = base_t->instance_id();
2289 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2290 "old type must be non-instance or match new type");
2291
2292 // The type 't' could be subclass of 'base_t'.
2293 // As result t->offset() could be large then base_t's size and it will
2294 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2295 // constructor verifies correctness of the offset.
2296 //
2297 // It could happened on subclass's branch (from the type profiling
2298 // inlining) which was not eliminated during parsing since the exactness
2299 // of the allocation type was not propagated to the subclass type check.
2300 //
2301 // Or the type 't' could be not related to 'base_t' at all.
2302 // It could happened when CHA type is different from MDO type on a dead path
2303 // (for example, from instanceof check) which is not collapsed during parsing.
2304 //
2305 // Do nothing for such AddP node and don't process its users since
2306 // this code branch will go away.
2307 //
2308 if (!t->is_known_instance() &&
2309 !base_t->klass()->is_subtype_of(t->klass())) {
2310 return false; // bail out
2311 }
2312 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2313 // Do NOT remove the next line: ensure a new alias index is allocated
2314 // for the instance type. Note: C++ will not remove it since the call
2315 // has side effect.
2316 int alias_idx = _compile->get_alias_index(tinst);
2317 igvn->set_type(addp, tinst);
2318 // record the allocation in the node map
2319 set_map(addp, get_map(base->_idx));
2320 // Set addp's Base and Address to 'base'.
2321 Node *abase = addp->in(AddPNode::Base);
2322 Node *adr = addp->in(AddPNode::Address);
2323 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2324 adr->in(0)->_idx == (uint)inst_id) {
2325 // Skip AddP cases #3 and #5.
2326 } else {
2327 assert(!abase->is_top(), "sanity"); // AddP case #3
2328 if (abase != base) {
2329 igvn->hash_delete(addp);
2330 addp->set_req(AddPNode::Base, base);
2331 if (abase == adr) {
2332 addp->set_req(AddPNode::Address, base);
2333 } else {
2334 // AddP case #4 (adr is array's element offset AddP node)
2335 #ifdef ASSERT
2336 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2337 assert(adr->is_AddP() && atype != NULL &&
2338 atype->instance_id() == inst_id, "array's element offset should be processed first");
2339 #endif
2340 }
2341 igvn->hash_insert(addp);
2342 }
2343 }
2344 // Put on IGVN worklist since at least addp's type was changed above.
2345 record_for_optimizer(addp);
2346 return true;
2347 }
2348
2349 //
2350 // Create a new version of orig_phi if necessary. Returns either the newly
2351 // created phi or an existing phi. Sets create_new to indicate whether a new
2352 // phi was created. Cache the last newly created phi in the node map.
2353 //
2354 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2355 Compile *C = _compile;
2356 PhaseGVN* igvn = _igvn;
2357 new_created = false;
2358 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2359 // nothing to do if orig_phi is bottom memory or matches alias_idx
2360 if (phi_alias_idx == alias_idx) {
2361 return orig_phi;
2362 }
2363 // Have we recently created a Phi for this alias index?
2364 PhiNode *result = get_map_phi(orig_phi->_idx);
2365 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2366 return result;
2367 }
2368 // Previous check may fail when the same wide memory Phi was split into Phis
2369 // for different memory slices. Search all Phis for this region.
2370 if (result != NULL) {
2371 Node* region = orig_phi->in(0);
2372 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2373 Node* phi = region->fast_out(i);
2374 if (phi->is_Phi() &&
2375 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2376 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2377 return phi->as_Phi();
2378 }
2379 }
2380 }
2381 if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2382 if (C->do_escape_analysis() == true && !C->failing()) {
2383 // Retry compilation without escape analysis.
2384 // If this is the first failure, the sentinel string will "stick"
2385 // to the Compile object, and the C2Compiler will see it and retry.
2386 C->record_failure(C2Compiler::retry_no_escape_analysis());
2387 }
2388 return NULL;
2389 }
2390 orig_phi_worklist.append_if_missing(orig_phi);
2391 const TypePtr *atype = C->get_adr_type(alias_idx);
2392 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2393 C->copy_node_notes_to(result, orig_phi);
2394 igvn->set_type(result, result->bottom_type());
2395 record_for_optimizer(result);
2396 set_map(orig_phi, result);
2397 new_created = true;
2398 return result;
2399 }
2400
2401 //
2402 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2403 // specified alias index.
2404 //
2405 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2406 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2407 Compile *C = _compile;
2408 PhaseGVN* igvn = _igvn;
2409 bool new_phi_created;
2410 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2411 if (!new_phi_created) {
2412 return result;
2413 }
2414 GrowableArray<PhiNode *> phi_list;
2415 GrowableArray<uint> cur_input;
2416 PhiNode *phi = orig_phi;
2417 uint idx = 1;
2418 bool finished = false;
2419 while(!finished) {
2420 while (idx < phi->req()) {
2421 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2422 if (mem != NULL && mem->is_Phi()) {
2423 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2424 if (new_phi_created) {
2425 // found an phi for which we created a new split, push current one on worklist and begin
2426 // processing new one
2427 phi_list.push(phi);
2428 cur_input.push(idx);
2429 phi = mem->as_Phi();
2430 result = newphi;
2431 idx = 1;
2432 continue;
2433 } else {
2434 mem = newphi;
2435 }
2436 }
2437 if (C->failing()) {
2438 return NULL;
2439 }
2440 result->set_req(idx++, mem);
2441 }
2442 #ifdef ASSERT
2443 // verify that the new Phi has an input for each input of the original
2444 assert( phi->req() == result->req(), "must have same number of inputs.");
2445 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2446 #endif
2447 // Check if all new phi's inputs have specified alias index.
2448 // Otherwise use old phi.
2449 for (uint i = 1; i < phi->req(); i++) {
2450 Node* in = result->in(i);
2451 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2452 }
2453 // we have finished processing a Phi, see if there are any more to do
2454 finished = (phi_list.length() == 0 );
2455 if (!finished) {
2456 phi = phi_list.pop();
2457 idx = cur_input.pop();
2458 PhiNode *prev_result = get_map_phi(phi->_idx);
2459 prev_result->set_req(idx++, result);
2460 result = prev_result;
2461 }
2462 }
2463 return result;
2464 }
2465
2466 //
2467 // The next methods are derived from methods in MemNode.
2468 //
2469 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2470 Node *mem = mmem;
2471 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2472 // means an array I have not precisely typed yet. Do not do any
2473 // alias stuff with it any time soon.
2474 if (toop->base() != Type::AnyPtr &&
2475 !(toop->klass() != NULL &&
2476 toop->klass()->is_java_lang_Object() &&
2477 toop->offset() == Type::OffsetBot)) {
2478 mem = mmem->memory_at(alias_idx);
2479 // Update input if it is progress over what we have now
2480 }
2481 return mem;
2482 }
2483
2484 //
2485 // Move memory users to their memory slices.
2486 //
2487 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2488 Compile* C = _compile;
2489 PhaseGVN* igvn = _igvn;
2490 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2491 assert(tp != NULL, "ptr type");
2492 int alias_idx = C->get_alias_index(tp);
2493 int general_idx = C->get_general_index(alias_idx);
2494
2495 // Move users first
2496 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2497 Node* use = n->fast_out(i);
2498 if (use->is_MergeMem()) {
2499 MergeMemNode* mmem = use->as_MergeMem();
2500 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2501 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2502 continue; // Nothing to do
2503 }
2504 // Replace previous general reference to mem node.
2505 uint orig_uniq = C->unique();
2506 Node* m = find_inst_mem(n, general_idx, orig_phis);
2507 assert(orig_uniq == C->unique(), "no new nodes");
2508 mmem->set_memory_at(general_idx, m);
2509 --imax;
2510 --i;
2511 } else if (use->is_MemBar()) {
2512 assert(!use->is_Initialize(), "initializing stores should not be moved");
2513 if (use->req() > MemBarNode::Precedent &&
2514 use->in(MemBarNode::Precedent) == n) {
2515 // Don't move related membars.
2516 record_for_optimizer(use);
2517 continue;
2518 }
2519 tp = use->as_MemBar()->adr_type()->isa_ptr();
2520 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2521 alias_idx == general_idx) {
2522 continue; // Nothing to do
2523 }
2524 // Move to general memory slice.
2525 uint orig_uniq = C->unique();
2526 Node* m = find_inst_mem(n, general_idx, orig_phis);
2527 assert(orig_uniq == C->unique(), "no new nodes");
2528 igvn->hash_delete(use);
2529 imax -= use->replace_edge(n, m);
2530 igvn->hash_insert(use);
2531 record_for_optimizer(use);
2532 --i;
2533 #ifdef ASSERT
2534 } else if (use->is_Mem()) {
2535 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2536 // Don't move related cardmark.
2537 continue;
2538 }
2539 // Memory nodes should have new memory input.
2540 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2541 assert(tp != NULL, "ptr type");
2542 int idx = C->get_alias_index(tp);
2543 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2544 "Following memory nodes should have new memory input or be on the same memory slice");
2545 } else if (use->is_Phi()) {
2546 // Phi nodes should be split and moved already.
2547 tp = use->as_Phi()->adr_type()->isa_ptr();
2548 assert(tp != NULL, "ptr type");
2549 int idx = C->get_alias_index(tp);
2550 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2551 } else {
2552 use->dump();
2553 assert(false, "should not be here");
2554 #endif
2555 }
2556 }
2557 }
2558
2559 //
2560 // Search memory chain of "mem" to find a MemNode whose address
2561 // is the specified alias index.
2562 //
2563 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2564 if (orig_mem == NULL)
2565 return orig_mem;
2566 Compile* C = _compile;
2567 PhaseGVN* igvn = _igvn;
2568 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2569 bool is_instance = (toop != NULL) && toop->is_known_instance();
2570 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2571 Node *prev = NULL;
2572 Node *result = orig_mem;
2573 while (prev != result) {
2574 prev = result;
2575 if (result == start_mem)
2576 break; // hit one of our sentinels
2577 if (result->is_Mem()) {
2578 const Type *at = igvn->type(result->in(MemNode::Address));
2579 if (at == Type::TOP)
2580 break; // Dead
2581 assert (at->isa_ptr() != NULL, "pointer type required.");
2582 int idx = C->get_alias_index(at->is_ptr());
2583 if (idx == alias_idx)
2584 break; // Found
2585 if (!is_instance && (at->isa_oopptr() == NULL ||
2586 !at->is_oopptr()->is_known_instance())) {
2587 break; // Do not skip store to general memory slice.
2588 }
2589 result = result->in(MemNode::Memory);
2590 }
2591 if (!is_instance)
2592 continue; // don't search further for non-instance types
2593 // skip over a call which does not affect this memory slice
2594 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2595 Node *proj_in = result->in(0);
2596 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2597 break; // hit one of our sentinels
2598 } else if (proj_in->is_Call()) {
2599 CallNode *call = proj_in->as_Call();
2600 if (!call->may_modify(toop, igvn)) {
2601 result = call->in(TypeFunc::Memory);
2602 }
2603 } else if (proj_in->is_Initialize()) {
2604 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2605 // Stop if this is the initialization for the object instance which
2606 // which contains this memory slice, otherwise skip over it.
2607 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2608 result = proj_in->in(TypeFunc::Memory);
2609 }
2610 } else if (proj_in->is_MemBar()) {
2611 result = proj_in->in(TypeFunc::Memory);
2612 }
2613 } else if (result->is_MergeMem()) {
2614 MergeMemNode *mmem = result->as_MergeMem();
2615 result = step_through_mergemem(mmem, alias_idx, toop);
2616 if (result == mmem->base_memory()) {
2617 // Didn't find instance memory, search through general slice recursively.
2618 result = mmem->memory_at(C->get_general_index(alias_idx));
2619 result = find_inst_mem(result, alias_idx, orig_phis);
2620 if (C->failing()) {
2621 return NULL;
2622 }
2623 mmem->set_memory_at(alias_idx, result);
2624 }
2625 } else if (result->is_Phi() &&
2626 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2627 Node *un = result->as_Phi()->unique_input(igvn);
2628 if (un != NULL) {
2629 orig_phis.append_if_missing(result->as_Phi());
2630 result = un;
2631 } else {
2632 break;
2633 }
2634 } else if (result->is_ClearArray()) {
2635 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2636 // Can not bypass initialization of the instance
2637 // we are looking for.
2638 break;
2639 }
2640 // Otherwise skip it (the call updated 'result' value).
2641 } else if (result->Opcode() == Op_SCMemProj) {
2642 Node* mem = result->in(0);
2643 Node* adr = NULL;
2644 if (mem->is_LoadStore()) {
2645 adr = mem->in(MemNode::Address);
2646 } else {
2647 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2648 adr = mem->in(3); // Memory edge corresponds to destination array
2649 }
2650 const Type *at = igvn->type(adr);
2651 if (at != Type::TOP) {
2652 assert (at->isa_ptr() != NULL, "pointer type required.");
2653 int idx = C->get_alias_index(at->is_ptr());
2654 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2655 break;
2656 }
2657 result = mem->in(MemNode::Memory);
2658 }
2659 }
2660 if (result->is_Phi()) {
2661 PhiNode *mphi = result->as_Phi();
2662 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2663 const TypePtr *t = mphi->adr_type();
2664 if (!is_instance) {
2665 // Push all non-instance Phis on the orig_phis worklist to update inputs
2666 // during Phase 4 if needed.
2667 orig_phis.append_if_missing(mphi);
2668 } else if (C->get_alias_index(t) != alias_idx) {
2669 // Create a new Phi with the specified alias index type.
2670 result = split_memory_phi(mphi, alias_idx, orig_phis);
2671 }
2672 }
2673 // the result is either MemNode, PhiNode, InitializeNode.
2674 return result;
2675 }
2676
2677 //
2678 // Convert the types of unescaped object to instance types where possible,
2679 // propagate the new type information through the graph, and update memory
2680 // edges and MergeMem inputs to reflect the new type.
2681 //
2682 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2683 // The processing is done in 4 phases:
2684 //
2685 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2686 // types for the CheckCastPP for allocations where possible.
2687 // Propagate the the new types through users as follows:
2688 // casts and Phi: push users on alloc_worklist
2689 // AddP: cast Base and Address inputs to the instance type
2690 // push any AddP users on alloc_worklist and push any memnode
2691 // users onto memnode_worklist.
2692 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2693 // search the Memory chain for a store with the appropriate type
2694 // address type. If a Phi is found, create a new version with
2695 // the appropriate memory slices from each of the Phi inputs.
2696 // For stores, process the users as follows:
2697 // MemNode: push on memnode_worklist
2698 // MergeMem: push on mergemem_worklist
2699 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2700 // moving the first node encountered of each instance type to the
2701 // the input corresponding to its alias index.
2702 // appropriate memory slice.
2703 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2704 //
2705 // In the following example, the CheckCastPP nodes are the cast of allocation
2706 // results and the allocation of node 29 is unescaped and eligible to be an
2707 // instance type.
2708 //
2709 // We start with:
2710 //
2711 // 7 Parm #memory
2712 // 10 ConI "12"
2713 // 19 CheckCastPP "Foo"
2714 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2715 // 29 CheckCastPP "Foo"
2716 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2717 //
2718 // 40 StoreP 25 7 20 ... alias_index=4
2719 // 50 StoreP 35 40 30 ... alias_index=4
2720 // 60 StoreP 45 50 20 ... alias_index=4
2721 // 70 LoadP _ 60 30 ... alias_index=4
2722 // 80 Phi 75 50 60 Memory alias_index=4
2723 // 90 LoadP _ 80 30 ... alias_index=4
2724 // 100 LoadP _ 80 20 ... alias_index=4
2725 //
2726 //
2727 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2728 // and creating a new alias index for node 30. This gives:
2729 //
2730 // 7 Parm #memory
2731 // 10 ConI "12"
2732 // 19 CheckCastPP "Foo"
2733 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2734 // 29 CheckCastPP "Foo" iid=24
2735 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2736 //
2737 // 40 StoreP 25 7 20 ... alias_index=4
2738 // 50 StoreP 35 40 30 ... alias_index=6
2739 // 60 StoreP 45 50 20 ... alias_index=4
2740 // 70 LoadP _ 60 30 ... alias_index=6
2741 // 80 Phi 75 50 60 Memory alias_index=4
2742 // 90 LoadP _ 80 30 ... alias_index=6
2743 // 100 LoadP _ 80 20 ... alias_index=4
2744 //
2745 // In phase 2, new memory inputs are computed for the loads and stores,
2746 // And a new version of the phi is created. In phase 4, the inputs to
2747 // node 80 are updated and then the memory nodes are updated with the
2748 // values computed in phase 2. This results in:
2749 //
2750 // 7 Parm #memory
2751 // 10 ConI "12"
2752 // 19 CheckCastPP "Foo"
2753 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2754 // 29 CheckCastPP "Foo" iid=24
2755 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2756 //
2757 // 40 StoreP 25 7 20 ... alias_index=4
2758 // 50 StoreP 35 7 30 ... alias_index=6
2759 // 60 StoreP 45 40 20 ... alias_index=4
2760 // 70 LoadP _ 50 30 ... alias_index=6
2761 // 80 Phi 75 40 60 Memory alias_index=4
2762 // 120 Phi 75 50 50 Memory alias_index=6
2763 // 90 LoadP _ 120 30 ... alias_index=6
2764 // 100 LoadP _ 80 20 ... alias_index=4
2765 //
2766 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2767 GrowableArray<Node *> memnode_worklist;
2768 GrowableArray<PhiNode *> orig_phis;
2769 PhaseIterGVN *igvn = _igvn;
2770 uint new_index_start = (uint) _compile->num_alias_types();
2771 Arena* arena = Thread::current()->resource_area();
2772 VectorSet visited(arena);
2773 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2774 uint unique_old = _compile->unique();
2775
2776 // Phase 1: Process possible allocations from alloc_worklist.
2777 // Create instance types for the CheckCastPP for allocations where possible.
2778 //
2779 // (Note: don't forget to change the order of the second AddP node on
2780 // the alloc_worklist if the order of the worklist processing is changed,
2781 // see the comment in find_second_addp().)
2782 //
2783 while (alloc_worklist.length() != 0) {
2784 Node *n = alloc_worklist.pop();
2785 uint ni = n->_idx;
2786 if (n->is_Call()) {
2787 CallNode *alloc = n->as_Call();
2788 // copy escape information to call node
2789 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2790 PointsToNode::EscapeState es = ptn->escape_state();
2791 // We have an allocation or call which returns a Java object,
2792 // see if it is unescaped.
2793 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2794 continue;
2795 // Find CheckCastPP for the allocate or for the return value of a call
2796 n = alloc->result_cast();
2797 if (n == NULL) { // No uses except Initialize node
2798 if (alloc->is_Allocate()) {
2799 // Set the scalar_replaceable flag for allocation
2800 // so it could be eliminated if it has no uses.
2801 alloc->as_Allocate()->_is_scalar_replaceable = true;
2802 }
2803 if (alloc->is_CallStaticJava()) {
2804 // Set the scalar_replaceable flag for boxing method
2805 // so it could be eliminated if it has no uses.
2806 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2807 }
2808 continue;
2809 }
2810 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2811 assert(!alloc->is_Allocate(), "allocation should have unique type");
2812 continue;
2813 }
2814
2815 // The inline code for Object.clone() casts the allocation result to
2816 // java.lang.Object and then to the actual type of the allocated
2817 // object. Detect this case and use the second cast.
2818 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2819 // the allocation result is cast to java.lang.Object and then
2820 // to the actual Array type.
2821 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2822 && (alloc->is_AllocateArray() ||
2823 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2824 Node *cast2 = NULL;
2825 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2826 Node *use = n->fast_out(i);
2827 if (use->is_CheckCastPP()) {
2828 cast2 = use;
2829 break;
2830 }
2831 }
2832 if (cast2 != NULL) {
2833 n = cast2;
2834 } else {
2835 // Non-scalar replaceable if the allocation type is unknown statically
2836 // (reflection allocation), the object can't be restored during
2837 // deoptimization without precise type.
2838 continue;
2839 }
2840 }
2841 if (alloc->is_Allocate()) {
2842 // Set the scalar_replaceable flag for allocation
2843 // so it could be eliminated.
2844 alloc->as_Allocate()->_is_scalar_replaceable = true;
2845 }
2846 if (alloc->is_CallStaticJava()) {
2847 // Set the scalar_replaceable flag for boxing method
2848 // so it could be eliminated.
2849 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2850 }
2851 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2852 // in order for an object to be scalar-replaceable, it must be:
2853 // - a direct allocation (not a call returning an object)
2854 // - non-escaping
2855 // - eligible to be a unique type
2856 // - not determined to be ineligible by escape analysis
2857 set_map(alloc, n);
2858 set_map(n, alloc);
2859 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2860 if (t == NULL)
2861 continue; // not a TypeOopPtr
2862 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2863 igvn->hash_delete(n);
2864 igvn->set_type(n, tinst);
2865 n->raise_bottom_type(tinst);
2866 igvn->hash_insert(n);
2867 record_for_optimizer(n);
2868 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2869
2870 // First, put on the worklist all Field edges from Connection Graph
2871 // which is more accurate then putting immediate users from Ideal Graph.
2872 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2873 PointsToNode* tgt = e.get();
2874 Node* use = tgt->ideal_node();
2875 assert(tgt->is_Field() && use->is_AddP(),
2876 "only AddP nodes are Field edges in CG");
2877 if (use->outcnt() > 0) { // Don't process dead nodes
2878 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2879 if (addp2 != NULL) {
2880 assert(alloc->is_AllocateArray(),"array allocation was expected");
2881 alloc_worklist.append_if_missing(addp2);
2882 }
2883 alloc_worklist.append_if_missing(use);
2884 }
2885 }
2886
2887 // An allocation may have an Initialize which has raw stores. Scan
2888 // the users of the raw allocation result and push AddP users
2889 // on alloc_worklist.
2890 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2891 assert (raw_result != NULL, "must have an allocation result");
2892 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2893 Node *use = raw_result->fast_out(i);
2894 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2895 Node* addp2 = find_second_addp(use, raw_result);
2896 if (addp2 != NULL) {
2897 assert(alloc->is_AllocateArray(),"array allocation was expected");
2898 alloc_worklist.append_if_missing(addp2);
2899 }
2900 alloc_worklist.append_if_missing(use);
2901 } else if (use->is_MemBar()) {
2902 memnode_worklist.append_if_missing(use);
2903 }
2904 }
2905 }
2906 } else if (n->is_AddP()) {
2907 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2908 if (jobj == NULL || jobj == phantom_obj) {
2909 #ifdef ASSERT
2910 ptnode_adr(get_addp_base(n)->_idx)->dump();
2911 ptnode_adr(n->_idx)->dump();
2912 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2913 #endif
2914 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2915 return;
2916 }
2917 Node *base = get_map(jobj->idx()); // CheckCastPP node
2918 if (!split_AddP(n, base)) continue; // wrong type from dead path
2919 } else if (n->is_Phi() ||
2920 n->is_CheckCastPP() ||
2921 n->is_EncodeP() ||
2922 n->is_DecodeN() ||
2923 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2924 if (visited.test_set(n->_idx)) {
2925 assert(n->is_Phi(), "loops only through Phi's");
2926 continue; // already processed
2927 }
2928 JavaObjectNode* jobj = unique_java_object(n);
2929 if (jobj == NULL || jobj == phantom_obj) {
2930 #ifdef ASSERT
2931 ptnode_adr(n->_idx)->dump();
2932 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2933 #endif
2934 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2935 return;
2936 } else {
2937 Node *val = get_map(jobj->idx()); // CheckCastPP node
2938 TypeNode *tn = n->as_Type();
2939 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2940 assert(tinst != NULL && tinst->is_known_instance() &&
2941 tinst->instance_id() == jobj->idx() , "instance type expected.");
2942
2943 const Type *tn_type = igvn->type(tn);
2944 const TypeOopPtr *tn_t;
2945 if (tn_type->isa_narrowoop()) {
2946 tn_t = tn_type->make_ptr()->isa_oopptr();
2947 } else {
2948 tn_t = tn_type->isa_oopptr();
2949 }
2950 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2951 if (tn_type->isa_narrowoop()) {
2952 tn_type = tinst->make_narrowoop();
2953 } else {
2954 tn_type = tinst;
2955 }
2956 igvn->hash_delete(tn);
2957 igvn->set_type(tn, tn_type);
2958 tn->set_type(tn_type);
2959 igvn->hash_insert(tn);
2960 record_for_optimizer(n);
2961 } else {
2962 assert(tn_type == TypePtr::NULL_PTR ||
2963 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2964 "unexpected type");
2965 continue; // Skip dead path with different type
2966 }
2967 }
2968 } else {
2969 debug_only(n->dump();)
2970 assert(false, "EA: unexpected node");
2971 continue;
2972 }
2973 // push allocation's users on appropriate worklist
2974 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2975 Node *use = n->fast_out(i);
2976 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2977 // Load/store to instance's field
2978 memnode_worklist.append_if_missing(use);
2979 } else if (use->is_MemBar()) {
2980 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
2981 memnode_worklist.append_if_missing(use);
2982 }
2983 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2984 Node* addp2 = find_second_addp(use, n);
2985 if (addp2 != NULL) {
2986 alloc_worklist.append_if_missing(addp2);
2987 }
2988 alloc_worklist.append_if_missing(use);
2989 } else if (use->is_Phi() ||
2990 use->is_CheckCastPP() ||
2991 use->is_EncodeNarrowPtr() ||
2992 use->is_DecodeNarrowPtr() ||
2993 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2994 alloc_worklist.append_if_missing(use);
2995 #ifdef ASSERT
2996 } else if (use->is_Mem()) {
2997 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2998 } else if (use->is_MergeMem()) {
2999 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3000 } else if (use->is_SafePoint()) {
3001 // Look for MergeMem nodes for calls which reference unique allocation
3002 // (through CheckCastPP nodes) even for debug info.
3003 Node* m = use->in(TypeFunc::Memory);
3004 if (m->is_MergeMem()) {
3005 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3006 }
3007 } else if (use->Opcode() == Op_EncodeISOArray) {
3008 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3009 // EncodeISOArray overwrites destination array
3010 memnode_worklist.append_if_missing(use);
3011 }
3012 } else {
3013 uint op = use->Opcode();
3014 if (!(op == Op_CmpP || op == Op_Conv2B ||
3015 op == Op_CastP2X || op == Op_StoreCM ||
3016 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3017 op == Op_StrEquals || op == Op_StrIndexOf)) {
3018 n->dump();
3019 use->dump();
3020 assert(false, "EA: missing allocation reference path");
3021 }
3022 #endif
3023 }
3024 }
3025
3026 }
3027 // New alias types were created in split_AddP().
3028 uint new_index_end = (uint) _compile->num_alias_types();
3029 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3030
3031 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3032 // compute new values for Memory inputs (the Memory inputs are not
3033 // actually updated until phase 4.)
3034 if (memnode_worklist.length() == 0)
3035 return; // nothing to do
3036 while (memnode_worklist.length() != 0) {
3037 Node *n = memnode_worklist.pop();
3038 if (visited.test_set(n->_idx))
3039 continue;
3040 if (n->is_Phi() || n->is_ClearArray()) {
3041 // we don't need to do anything, but the users must be pushed
3042 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3043 // we don't need to do anything, but the users must be pushed
3044 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3045 if (n == NULL)
3046 continue;
3047 } else if (n->Opcode() == Op_EncodeISOArray) {
3048 // get the memory projection
3049 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3050 Node *use = n->fast_out(i);
3051 if (use->Opcode() == Op_SCMemProj) {
3052 n = use;
3053 break;
3054 }
3055 }
3056 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3057 } else {
3058 assert(n->is_Mem(), "memory node required.");
3059 Node *addr = n->in(MemNode::Address);
3060 const Type *addr_t = igvn->type(addr);
3061 if (addr_t == Type::TOP)
3062 continue;
3063 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3064 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3065 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3066 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3067 if (_compile->failing()) {
3068 return;
3069 }
3070 if (mem != n->in(MemNode::Memory)) {
3071 // We delay the memory edge update since we need old one in
3072 // MergeMem code below when instances memory slices are separated.
3073 set_map(n, mem);
3074 }
3075 if (n->is_Load()) {
3076 continue; // don't push users
3077 } else if (n->is_LoadStore()) {
3078 // get the memory projection
3079 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3080 Node *use = n->fast_out(i);
3081 if (use->Opcode() == Op_SCMemProj) {
3082 n = use;
3083 break;
3084 }
3085 }
3086 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3087 }
3088 }
3089 // push user on appropriate worklist
3090 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3091 Node *use = n->fast_out(i);
3092 if (use->is_Phi() || use->is_ClearArray()) {
3093 memnode_worklist.append_if_missing(use);
3094 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3095 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3096 continue;
3097 memnode_worklist.append_if_missing(use);
3098 } else if (use->is_MemBar()) {
3099 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3100 memnode_worklist.append_if_missing(use);
3101 }
3102 #ifdef ASSERT
3103 } else if(use->is_Mem()) {
3104 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3105 } else if (use->is_MergeMem()) {
3106 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3107 } else if (use->Opcode() == Op_EncodeISOArray) {
3108 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3109 // EncodeISOArray overwrites destination array
3110 memnode_worklist.append_if_missing(use);
3111 }
3112 } else {
3113 uint op = use->Opcode();
3114 if (!(op == Op_StoreCM ||
3115 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3116 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3117 op == Op_AryEq || op == Op_StrComp ||
3118 op == Op_StrEquals || op == Op_StrIndexOf)) {
3119 n->dump();
3120 use->dump();
3121 assert(false, "EA: missing memory path");
3122 }
3123 #endif
3124 }
3125 }
3126 }
3127
3128 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3129 // Walk each memory slice moving the first node encountered of each
3130 // instance type to the the input corresponding to its alias index.
3131 uint length = _mergemem_worklist.length();
3132 for( uint next = 0; next < length; ++next ) {
3133 MergeMemNode* nmm = _mergemem_worklist.at(next);
3134 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3135 // Note: we don't want to use MergeMemStream here because we only want to
3136 // scan inputs which exist at the start, not ones we add during processing.
3137 // Note 2: MergeMem may already contains instance memory slices added
3138 // during find_inst_mem() call when memory nodes were processed above.
3139 igvn->hash_delete(nmm);
3140 uint nslices = nmm->req();
3141 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3142 Node* mem = nmm->in(i);
3143 Node* cur = NULL;
3144 if (mem == NULL || mem->is_top())
3145 continue;
3146 // First, update mergemem by moving memory nodes to corresponding slices
3147 // if their type became more precise since this mergemem was created.
3148 while (mem->is_Mem()) {
3149 const Type *at = igvn->type(mem->in(MemNode::Address));
3150 if (at != Type::TOP) {
3151 assert (at->isa_ptr() != NULL, "pointer type required.");
3152 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3153 if (idx == i) {
3154 if (cur == NULL)
3155 cur = mem;
3156 } else {
3157 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3158 nmm->set_memory_at(idx, mem);
3159 }
3160 }
3161 }
3162 mem = mem->in(MemNode::Memory);
3163 }
3164 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3165 // Find any instance of the current type if we haven't encountered
3166 // already a memory slice of the instance along the memory chain.
3167 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3168 if((uint)_compile->get_general_index(ni) == i) {
3169 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3170 if (nmm->is_empty_memory(m)) {
3171 Node* result = find_inst_mem(mem, ni, orig_phis);
3172 if (_compile->failing()) {
3173 return;
3174 }
3175 nmm->set_memory_at(ni, result);
3176 }
3177 }
3178 }
3179 }
3180 // Find the rest of instances values
3181 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3182 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3183 Node* result = step_through_mergemem(nmm, ni, tinst);
3184 if (result == nmm->base_memory()) {
3185 // Didn't find instance memory, search through general slice recursively.
3186 result = nmm->memory_at(_compile->get_general_index(ni));
3187 result = find_inst_mem(result, ni, orig_phis);
3188 if (_compile->failing()) {
3189 return;
3190 }
3191 nmm->set_memory_at(ni, result);
3192 }
3193 }
3194 igvn->hash_insert(nmm);
3195 record_for_optimizer(nmm);
3196 }
3197
3198 // Phase 4: Update the inputs of non-instance memory Phis and
3199 // the Memory input of memnodes
3200 // First update the inputs of any non-instance Phi's from
3201 // which we split out an instance Phi. Note we don't have
3202 // to recursively process Phi's encounted on the input memory
3203 // chains as is done in split_memory_phi() since they will
3204 // also be processed here.
3205 for (int j = 0; j < orig_phis.length(); j++) {
3206 PhiNode *phi = orig_phis.at(j);
3207 int alias_idx = _compile->get_alias_index(phi->adr_type());
3208 igvn->hash_delete(phi);
3209 for (uint i = 1; i < phi->req(); i++) {
3210 Node *mem = phi->in(i);
3211 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3212 if (_compile->failing()) {
3213 return;
3214 }
3215 if (mem != new_mem) {
3216 phi->set_req(i, new_mem);
3217 }
3218 }
3219 igvn->hash_insert(phi);
3220 record_for_optimizer(phi);
3221 }
3222
3223 // Update the memory inputs of MemNodes with the value we computed
3224 // in Phase 2 and move stores memory users to corresponding memory slices.
3225 // Disable memory split verification code until the fix for 6984348.
3226 // Currently it produces false negative results since it does not cover all cases.
3227 #if 0 // ifdef ASSERT
3228 visited.Reset();
3229 Node_Stack old_mems(arena, _compile->unique() >> 2);
3230 #endif
3231 for (uint i = 0; i < ideal_nodes.size(); i++) {
3232 Node* n = ideal_nodes.at(i);
3233 Node* nmem = get_map(n->_idx);
3234 assert(nmem != NULL, "sanity");
3235 if (n->is_Mem()) {
3236 #if 0 // ifdef ASSERT
3237 Node* old_mem = n->in(MemNode::Memory);
3238 if (!visited.test_set(old_mem->_idx)) {
3239 old_mems.push(old_mem, old_mem->outcnt());
3240 }
3241 #endif
3242 assert(n->in(MemNode::Memory) != nmem, "sanity");
3243 if (!n->is_Load()) {
3244 // Move memory users of a store first.
3245 move_inst_mem(n, orig_phis);
3246 }
3247 // Now update memory input
3248 igvn->hash_delete(n);
3249 n->set_req(MemNode::Memory, nmem);
3250 igvn->hash_insert(n);
3251 record_for_optimizer(n);
3252 } else {
3253 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3254 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3255 }
3256 }
3257 #if 0 // ifdef ASSERT
3258 // Verify that memory was split correctly
3259 while (old_mems.is_nonempty()) {
3260 Node* old_mem = old_mems.node();
3261 uint old_cnt = old_mems.index();
3262 old_mems.pop();
3263 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3264 }
3265 #endif
3266 }
3267
3268 #ifndef PRODUCT
3269 static const char *node_type_names[] = {
3270 "UnknownType",
3271 "JavaObject",
3272 "LocalVar",
3273 "Field",
3274 "Arraycopy"
3275 };
3276
3277 static const char *esc_names[] = {
3278 "UnknownEscape",
3279 "NoEscape",
3280 "ArgEscape",
3281 "GlobalEscape"
3282 };
3283
3284 void PointsToNode::dump(bool print_state) const {
3285 NodeType nt = node_type();
3286 tty->print("%s ", node_type_names[(int) nt]);
3287 if (print_state) {
3288 EscapeState es = escape_state();
3289 EscapeState fields_es = fields_escape_state();
3290 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3291 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3292 tty->print("NSR ");
3293 }
3294 if (is_Field()) {
3295 FieldNode* f = (FieldNode*)this;
3296 if (f->is_oop())
3297 tty->print("oop ");
3298 if (f->offset() > 0)
3299 tty->print("+%d ", f->offset());
3300 tty->print("(");
3301 for (BaseIterator i(f); i.has_next(); i.next()) {
3302 PointsToNode* b = i.get();
3303 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3304 }
3305 tty->print(" )");
3306 }
3307 tty->print("[");
3308 for (EdgeIterator i(this); i.has_next(); i.next()) {
3309 PointsToNode* e = i.get();
3310 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3311 }
3312 tty->print(" [");
3313 for (UseIterator i(this); i.has_next(); i.next()) {
3314 PointsToNode* u = i.get();
3315 bool is_base = false;
3316 if (PointsToNode::is_base_use(u)) {
3317 is_base = true;
3318 u = PointsToNode::get_use_node(u)->as_Field();
3319 }
3320 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3321 }
3322 tty->print(" ]] ");
3323 if (_node == NULL)
3324 tty->print_cr("<null>");
3325 else
3326 _node->dump();
3327 }
3328
3329 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3330 bool first = true;
3331 int ptnodes_length = ptnodes_worklist.length();
3332 for (int i = 0; i < ptnodes_length; i++) {
3333 PointsToNode *ptn = ptnodes_worklist.at(i);
3334 if (ptn == NULL || !ptn->is_JavaObject())
3335 continue;
3336 PointsToNode::EscapeState es = ptn->escape_state();
3337 if ((es != PointsToNode::NoEscape) && !Verbose) {
3338 continue;
3339 }
3340 Node* n = ptn->ideal_node();
3341 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3342 n->as_CallStaticJava()->is_boxing_method())) {
3343 if (first) {
3344 tty->cr();
3345 tty->print("======== Connection graph for ");
3346 _compile->method()->print_short_name();
3347 tty->cr();
3348 first = false;
3349 }
3350 ptn->dump();
3351 // Print all locals and fields which reference this allocation
3352 for (UseIterator j(ptn); j.has_next(); j.next()) {
3353 PointsToNode* use = j.get();
3354 if (use->is_LocalVar()) {
3355 use->dump(Verbose);
3356 } else if (Verbose) {
3357 use->dump();
3358 }
3359 }
3360 tty->cr();
3361 }
3362 }
3363 }
3364 #endif