1 /*
2 * Copyright (c) 2005, 2012, 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/rootnode.hpp"
37
38 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
39 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
40 _collecting(true),
41 _verify(false),
42 _compile(C),
43 _igvn(igvn),
44 _node_map(C->comp_arena()) {
45 // Add unknown java object.
46 add_java_object(C->top(), PointsToNode::GlobalEscape);
47 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
48 // Add ConP(#NULL) and ConN(#NULL) nodes.
49 Node* oop_null = igvn->zerocon(T_OBJECT);
50 assert(oop_null->_idx < nodes_size(), "should be created already");
51 add_java_object(oop_null, PointsToNode::NoEscape);
52 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
53 if (UseCompressedOops) {
54 Node* noop_null = igvn->zerocon(T_NARROWOOP);
55 assert(noop_null->_idx < nodes_size(), "should be created already");
56 map_ideal_node(noop_null, null_obj);
57 }
58 _pcmp_neq = NULL; // Should be initialized
59 _pcmp_eq = NULL;
60 }
61
62 bool ConnectionGraph::has_candidates(Compile *C) {
63 // EA brings benefits only when the code has allocations and/or locks which
64 // are represented by ideal Macro nodes.
65 int cnt = C->macro_count();
66 for( int i=0; i < cnt; i++ ) {
67 Node *n = C->macro_node(i);
68 if ( n->is_Allocate() )
69 return true;
70 if( n->is_Lock() ) {
71 Node* obj = n->as_Lock()->obj_node()->uncast();
72 if( !(obj->is_Parm() || obj->is_Con()) )
73 return true;
74 }
75 }
76 return false;
77 }
78
79 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
80 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
81 ResourceMark rm;
82
83 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
84 // to create space for them in ConnectionGraph::_nodes[].
85 Node* oop_null = igvn->zerocon(T_OBJECT);
86 Node* noop_null = igvn->zerocon(T_NARROWOOP);
87 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
88 // Perform escape analysis
89 if (congraph->compute_escape()) {
90 // There are non escaping objects.
91 C->set_congraph(congraph);
92 }
93 // Cleanup.
94 if (oop_null->outcnt() == 0)
95 igvn->hash_delete(oop_null);
96 if (noop_null->outcnt() == 0)
97 igvn->hash_delete(noop_null);
98 }
99
100 bool ConnectionGraph::compute_escape() {
101 Compile* C = _compile;
102 PhaseGVN* igvn = _igvn;
103
104 // Worklists used by EA.
105 Unique_Node_List delayed_worklist;
106 GrowableArray<Node*> alloc_worklist;
107 GrowableArray<Node*> ptr_cmp_worklist;
108 GrowableArray<Node*> storestore_worklist;
109 GrowableArray<PointsToNode*> ptnodes_worklist;
110 GrowableArray<JavaObjectNode*> java_objects_worklist;
111 GrowableArray<JavaObjectNode*> non_escaped_worklist;
112 GrowableArray<FieldNode*> oop_fields_worklist;
113 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
114
115 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
116
117 // 1. Populate Connection Graph (CG) with PointsTo nodes.
118 ideal_nodes.map(C->unique(), NULL); // preallocate space
119 // Initialize worklist
120 if (C->root() != NULL) {
121 ideal_nodes.push(C->root());
122 }
123 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
124 Node* n = ideal_nodes.at(next);
125 // Create PointsTo nodes and add them to Connection Graph. Called
126 // only once per ideal node since ideal_nodes is Unique_Node list.
127 add_node_to_connection_graph(n, &delayed_worklist);
128 PointsToNode* ptn = ptnode_adr(n->_idx);
129 if (ptn != NULL) {
130 ptnodes_worklist.append(ptn);
131 if (ptn->is_JavaObject()) {
132 java_objects_worklist.append(ptn->as_JavaObject());
133 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
134 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
135 // Only allocations and java static calls results are interesting.
136 non_escaped_worklist.append(ptn->as_JavaObject());
137 }
138 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
139 oop_fields_worklist.append(ptn->as_Field());
140 }
141 }
142 if (n->is_MergeMem()) {
143 // Collect all MergeMem nodes to add memory slices for
144 // scalar replaceable objects in split_unique_types().
145 _mergemem_worklist.append(n->as_MergeMem());
146 } else if (OptimizePtrCompare && n->is_Cmp() &&
147 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
148 // Collect compare pointers nodes.
149 ptr_cmp_worklist.append(n);
150 } else if (n->is_MemBarStoreStore()) {
151 // Collect all MemBarStoreStore nodes so that depending on the
152 // escape status of the associated Allocate node some of them
153 // may be eliminated.
154 storestore_worklist.append(n);
155 #ifdef ASSERT
156 } else if(n->is_AddP()) {
157 // Collect address nodes for graph verification.
158 addp_worklist.append(n);
159 #endif
160 }
161 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
162 Node* m = n->fast_out(i); // Get user
163 ideal_nodes.push(m);
164 }
165 }
166 if (non_escaped_worklist.length() == 0) {
167 _collecting = false;
168 return false; // Nothing to do.
169 }
170 // Add final simple edges to graph.
171 while(delayed_worklist.size() > 0) {
172 Node* n = delayed_worklist.pop();
173 add_final_edges(n);
174 }
175 int ptnodes_length = ptnodes_worklist.length();
176
177 #ifdef ASSERT
178 if (VerifyConnectionGraph) {
179 // Verify that no new simple edges could be created and all
180 // local vars has edges.
181 _verify = true;
182 for (int next = 0; next < ptnodes_length; ++next) {
183 PointsToNode* ptn = ptnodes_worklist.at(next);
184 add_final_edges(ptn->ideal_node());
185 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
186 ptn->dump();
187 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
188 }
189 }
190 _verify = false;
191 }
192 #endif
193
194 // 2. Finish Graph construction by propagating references to all
195 // java objects through graph.
196 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
197 java_objects_worklist, oop_fields_worklist)) {
198 // All objects escaped or hit time or iterations limits.
199 _collecting = false;
200 return false;
201 }
202
203 // 3. Adjust scalar_replaceable state of nonescaping objects and push
204 // scalar replaceable allocations on alloc_worklist for processing
205 // in split_unique_types().
206 int non_escaped_length = non_escaped_worklist.length();
207 for (int next = 0; next < non_escaped_length; next++) {
208 JavaObjectNode* ptn = non_escaped_worklist.at(next);
209 if (ptn->escape_state() == PointsToNode::NoEscape &&
210 ptn->scalar_replaceable()) {
211 adjust_scalar_replaceable_state(ptn);
212 if (ptn->scalar_replaceable()) {
213 alloc_worklist.append(ptn->ideal_node());
214 }
215 }
216 }
217
218 #ifdef ASSERT
219 if (VerifyConnectionGraph) {
220 // Verify that graph is complete - no new edges could be added or needed.
221 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
222 java_objects_worklist, addp_worklist);
223 }
224 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
225 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
226 null_obj->edge_count() == 0 &&
227 !null_obj->arraycopy_src() &&
228 !null_obj->arraycopy_dst(), "sanity");
229 #endif
230
231 _collecting = false;
232
233 } // TracePhase t3("connectionGraph")
234
235 // 4. Optimize ideal graph based on EA information.
236 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
237 if (has_non_escaping_obj) {
238 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
239 }
240
241 #ifndef PRODUCT
242 if (PrintEscapeAnalysis) {
243 dump(ptnodes_worklist); // Dump ConnectionGraph
244 }
245 #endif
246
247 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
248 #ifdef ASSERT
249 if (VerifyConnectionGraph) {
250 int alloc_length = alloc_worklist.length();
251 for (int next = 0; next < alloc_length; ++next) {
252 Node* n = alloc_worklist.at(next);
253 PointsToNode* ptn = ptnode_adr(n->_idx);
254 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
255 }
256 }
257 #endif
258
259 // 5. Separate memory graph for scalar replaceable allcations.
260 if (has_scalar_replaceable_candidates &&
261 C->AliasLevel() >= 3 && EliminateAllocations) {
262 // Now use the escape information to create unique types for
263 // scalar replaceable objects.
264 split_unique_types(alloc_worklist);
265 if (C->failing()) return false;
266 C->print_method(PHASE_AFTER_EA, 2);
267
268 #ifdef ASSERT
269 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
270 tty->print("=== No allocations eliminated for ");
271 C->method()->print_short_name();
272 if(!EliminateAllocations) {
273 tty->print(" since EliminateAllocations is off ===");
274 } else if(!has_scalar_replaceable_candidates) {
275 tty->print(" since there are no scalar replaceable candidates ===");
276 } else if(C->AliasLevel() < 3) {
277 tty->print(" since AliasLevel < 3 ===");
278 }
279 tty->cr();
280 #endif
281 }
282 return has_non_escaping_obj;
283 }
284
285 // Utility function for nodes that load an object
286 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
287 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
288 // ThreadLocal has RawPtr type.
289 const Type* t = _igvn->type(n);
290 if (t->make_ptr() != NULL) {
291 Node* adr = n->in(MemNode::Address);
292 #ifdef ASSERT
293 if (!adr->is_AddP()) {
294 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
295 } else {
296 assert((ptnode_adr(adr->_idx) == NULL ||
297 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
298 }
299 #endif
300 add_local_var_and_edge(n, PointsToNode::NoEscape,
301 adr, delayed_worklist);
302 }
303 }
304
305 // Populate Connection Graph with PointsTo nodes and create simple
306 // connection graph edges.
307 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
308 assert(!_verify, "this method sould not be called for verification");
309 PhaseGVN* igvn = _igvn;
310 uint n_idx = n->_idx;
311 PointsToNode* n_ptn = ptnode_adr(n_idx);
312 if (n_ptn != NULL)
313 return; // No need to redefine PointsTo node during first iteration.
314
315 if (n->is_Call()) {
316 // Arguments to allocation and locking don't escape.
317 if (n->is_AbstractLock()) {
318 // Put Lock and Unlock nodes on IGVN worklist to process them during
319 // first IGVN optimization when escape information is still available.
320 record_for_optimizer(n);
321 } else if (n->is_Allocate()) {
322 add_call_node(n->as_Call());
323 record_for_optimizer(n);
324 } else {
325 if (n->is_CallStaticJava()) {
326 const char* name = n->as_CallStaticJava()->_name;
327 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
328 return; // Skip uncommon traps
329 }
330 // Don't mark as processed since call's arguments have to be processed.
331 delayed_worklist->push(n);
332 // Check if a call returns an object.
333 if (n->as_Call()->returns_pointer() &&
334 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
335 add_call_node(n->as_Call());
336 }
337 }
338 return;
339 }
340 // Put this check here to process call arguments since some call nodes
341 // point to phantom_obj.
342 if (n_ptn == phantom_obj || n_ptn == null_obj)
343 return; // Skip predefined nodes.
344
345 int opcode = n->Opcode();
346 switch (opcode) {
347 case Op_AddP: {
348 Node* base = get_addp_base(n);
349 PointsToNode* ptn_base = ptnode_adr(base->_idx);
350 // Field nodes are created for all field types. They are used in
351 // adjust_scalar_replaceable_state() and split_unique_types().
352 // Note, non-oop fields will have only base edges in Connection
353 // Graph because such fields are not used for oop loads and stores.
354 int offset = address_offset(n, igvn);
355 add_field(n, PointsToNode::NoEscape, offset);
356 if (ptn_base == NULL) {
357 delayed_worklist->push(n); // Process it later.
358 } else {
359 n_ptn = ptnode_adr(n_idx);
360 add_base(n_ptn->as_Field(), ptn_base);
361 }
362 break;
363 }
364 case Op_CastX2P: {
365 map_ideal_node(n, phantom_obj);
366 break;
367 }
368 case Op_CastPP:
369 case Op_CheckCastPP:
370 case Op_EncodeP:
371 case Op_DecodeN: {
372 add_local_var_and_edge(n, PointsToNode::NoEscape,
373 n->in(1), delayed_worklist);
374 break;
375 }
376 case Op_CMoveP: {
377 add_local_var(n, PointsToNode::NoEscape);
378 // Do not add edges during first iteration because some could be
379 // not defined yet.
380 delayed_worklist->push(n);
381 break;
382 }
383 case Op_ConP:
384 case Op_ConN: {
385 // assume all oop constants globally escape except for null
386 PointsToNode::EscapeState es;
387 if (igvn->type(n) == TypePtr::NULL_PTR ||
388 igvn->type(n) == TypeNarrowOop::NULL_PTR) {
389 es = PointsToNode::NoEscape;
390 } else {
391 es = PointsToNode::GlobalEscape;
392 }
393 add_java_object(n, es);
394 break;
395 }
396 case Op_CreateEx: {
397 // assume that all exception objects globally escape
398 add_java_object(n, PointsToNode::GlobalEscape);
399 break;
400 }
401 case Op_LoadKlass:
402 case Op_LoadNKlass: {
403 // Unknown class is loaded
404 map_ideal_node(n, phantom_obj);
405 break;
406 }
407 case Op_LoadP:
408 case Op_LoadN:
409 case Op_LoadPLocked: {
410 add_objload_to_connection_graph(n, delayed_worklist);
411 break;
412 }
413 case Op_Parm: {
414 map_ideal_node(n, phantom_obj);
415 break;
416 }
417 case Op_PartialSubtypeCheck: {
418 // Produces Null or notNull and is used in only in CmpP so
419 // phantom_obj could be used.
420 map_ideal_node(n, phantom_obj); // Result is unknown
421 break;
422 }
423 case Op_Phi: {
424 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
425 // ThreadLocal has RawPtr type.
426 const Type* t = n->as_Phi()->type();
427 if (t->make_ptr() != NULL) {
428 add_local_var(n, PointsToNode::NoEscape);
429 // Do not add edges during first iteration because some could be
430 // not defined yet.
431 delayed_worklist->push(n);
432 }
433 break;
434 }
435 case Op_Proj: {
436 // we are only interested in the oop result projection from a call
437 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
438 n->in(0)->as_Call()->returns_pointer()) {
439 add_local_var_and_edge(n, PointsToNode::NoEscape,
440 n->in(0), delayed_worklist);
441 }
442 break;
443 }
444 case Op_Rethrow: // Exception object escapes
445 case Op_Return: {
446 if (n->req() > TypeFunc::Parms &&
447 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
448 // Treat Return value as LocalVar with GlobalEscape escape state.
449 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
450 n->in(TypeFunc::Parms), delayed_worklist);
451 }
452 break;
453 }
454 case Op_GetAndSetP:
455 case Op_GetAndSetN: {
456 add_objload_to_connection_graph(n, delayed_worklist);
457 // fallthrough
458 }
459 case Op_StoreP:
460 case Op_StoreN:
461 case Op_StorePConditional:
462 case Op_CompareAndSwapP:
463 case Op_CompareAndSwapN: {
464 Node* adr = n->in(MemNode::Address);
465 const Type *adr_type = igvn->type(adr);
466 adr_type = adr_type->make_ptr();
467 if (adr_type == NULL) {
468 break; // skip dead nodes
469 }
470 if (adr_type->isa_oopptr() ||
471 (opcode == Op_StoreP || opcode == Op_StoreN) &&
472 (adr_type == TypeRawPtr::NOTNULL &&
473 adr->in(AddPNode::Address)->is_Proj() &&
474 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
475 delayed_worklist->push(n); // Process it later.
476 #ifdef ASSERT
477 assert(adr->is_AddP(), "expecting an AddP");
478 if (adr_type == TypeRawPtr::NOTNULL) {
479 // Verify a raw address for a store captured by Initialize node.
480 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
481 assert(offs != Type::OffsetBot, "offset must be a constant");
482 }
483 #endif
484 } else {
485 // Ignore copy the displaced header to the BoxNode (OSR compilation).
486 if (adr->is_BoxLock())
487 break;
488 // Stored value escapes in unsafe access.
489 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
490 // Pointer stores in G1 barriers looks like unsafe access.
491 // Ignore such stores to be able scalar replace non-escaping
492 // allocations.
493 if (UseG1GC && adr->is_AddP()) {
494 Node* base = get_addp_base(adr);
495 if (base->Opcode() == Op_LoadP &&
496 base->in(MemNode::Address)->is_AddP()) {
497 adr = base->in(MemNode::Address);
498 Node* tls = get_addp_base(adr);
499 if (tls->Opcode() == Op_ThreadLocal) {
500 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
501 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
502 PtrQueue::byte_offset_of_buf())) {
503 break; // G1 pre barier previous oop value store.
504 }
505 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
506 PtrQueue::byte_offset_of_buf())) {
507 break; // G1 post barier card address store.
508 }
509 }
510 }
511 }
512 delayed_worklist->push(n); // Process unsafe access later.
513 break;
514 }
515 #ifdef ASSERT
516 n->dump(1);
517 assert(false, "not unsafe or G1 barrier raw StoreP");
518 #endif
519 }
520 break;
521 }
522 case Op_AryEq:
523 case Op_StrComp:
524 case Op_StrEquals:
525 case Op_StrIndexOf: {
526 add_local_var(n, PointsToNode::ArgEscape);
527 delayed_worklist->push(n); // Process it later.
528 break;
529 }
530 case Op_ThreadLocal: {
531 add_java_object(n, PointsToNode::ArgEscape);
532 break;
533 }
534 default:
535 ; // Do nothing for nodes not related to EA.
536 }
537 return;
538 }
539
540 #ifdef ASSERT
541 #define ELSE_FAIL(name) \
542 /* Should not be called for not pointer type. */ \
543 n->dump(1); \
544 assert(false, name); \
545 break;
546 #else
547 #define ELSE_FAIL(name) \
548 break;
549 #endif
550
551 // Add final simple edges to graph.
552 void ConnectionGraph::add_final_edges(Node *n) {
553 PointsToNode* n_ptn = ptnode_adr(n->_idx);
554 #ifdef ASSERT
555 if (_verify && n_ptn->is_JavaObject())
556 return; // This method does not change graph for JavaObject.
557 #endif
558
559 if (n->is_Call()) {
560 process_call_arguments(n->as_Call());
561 return;
562 }
563 assert(n->is_Store() || n->is_LoadStore() ||
564 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
565 "node should be registered already");
566 int opcode = n->Opcode();
567 switch (opcode) {
568 case Op_AddP: {
569 Node* base = get_addp_base(n);
570 PointsToNode* ptn_base = ptnode_adr(base->_idx);
571 assert(ptn_base != NULL, "field's base should be registered");
572 add_base(n_ptn->as_Field(), ptn_base);
573 break;
574 }
575 case Op_CastPP:
576 case Op_CheckCastPP:
577 case Op_EncodeP:
578 case Op_DecodeN: {
579 add_local_var_and_edge(n, PointsToNode::NoEscape,
580 n->in(1), NULL);
581 break;
582 }
583 case Op_CMoveP: {
584 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
585 Node* in = n->in(i);
586 if (in == NULL)
587 continue; // ignore NULL
588 Node* uncast_in = in->uncast();
589 if (uncast_in->is_top() || uncast_in == n)
590 continue; // ignore top or inputs which go back this node
591 PointsToNode* ptn = ptnode_adr(in->_idx);
592 assert(ptn != NULL, "node should be registered");
593 add_edge(n_ptn, ptn);
594 }
595 break;
596 }
597 case Op_LoadP:
598 case Op_LoadN:
599 case Op_LoadPLocked: {
600 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
601 // ThreadLocal has RawPtr type.
602 const Type* t = _igvn->type(n);
603 if (t->make_ptr() != NULL) {
604 Node* adr = n->in(MemNode::Address);
605 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
606 break;
607 }
608 ELSE_FAIL("Op_LoadP");
609 }
610 case Op_Phi: {
611 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
612 // ThreadLocal has RawPtr type.
613 const Type* t = n->as_Phi()->type();
614 if (t->make_ptr() != NULL) {
615 for (uint i = 1; i < n->req(); i++) {
616 Node* in = n->in(i);
617 if (in == NULL)
618 continue; // ignore NULL
619 Node* uncast_in = in->uncast();
620 if (uncast_in->is_top() || uncast_in == n)
621 continue; // ignore top or inputs which go back this node
622 PointsToNode* ptn = ptnode_adr(in->_idx);
623 assert(ptn != NULL, "node should be registered");
624 add_edge(n_ptn, ptn);
625 }
626 break;
627 }
628 ELSE_FAIL("Op_Phi");
629 }
630 case Op_Proj: {
631 // we are only interested in the oop result projection from a call
632 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
633 n->in(0)->as_Call()->returns_pointer()) {
634 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
635 break;
636 }
637 ELSE_FAIL("Op_Proj");
638 }
639 case Op_Rethrow: // Exception object escapes
640 case Op_Return: {
641 if (n->req() > TypeFunc::Parms &&
642 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
643 // Treat Return value as LocalVar with GlobalEscape escape state.
644 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
645 n->in(TypeFunc::Parms), NULL);
646 break;
647 }
648 ELSE_FAIL("Op_Return");
649 }
650 case Op_StoreP:
651 case Op_StoreN:
652 case Op_StorePConditional:
653 case Op_CompareAndSwapP:
654 case Op_CompareAndSwapN:
655 case Op_GetAndSetP:
656 case Op_GetAndSetN: {
657 Node* adr = n->in(MemNode::Address);
658 const Type *adr_type = _igvn->type(adr);
659 adr_type = adr_type->make_ptr();
660 #ifdef ASSERT
661 if (adr_type == NULL) {
662 n->dump(1);
663 assert(adr_type != NULL, "dead node should not be on list");
664 break;
665 }
666 #endif
667 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
668 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
669 }
670 if (adr_type->isa_oopptr() ||
671 (opcode == Op_StoreP || opcode == Op_StoreN) &&
672 (adr_type == TypeRawPtr::NOTNULL &&
673 adr->in(AddPNode::Address)->is_Proj() &&
674 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
675 // Point Address to Value
676 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
677 assert(adr_ptn != NULL &&
678 adr_ptn->as_Field()->is_oop(), "node should be registered");
679 Node *val = n->in(MemNode::ValueIn);
680 PointsToNode* ptn = ptnode_adr(val->_idx);
681 assert(ptn != NULL, "node should be registered");
682 add_edge(adr_ptn, ptn);
683 break;
684 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
685 // Stored value escapes in unsafe access.
686 Node *val = n->in(MemNode::ValueIn);
687 PointsToNode* ptn = ptnode_adr(val->_idx);
688 assert(ptn != NULL, "node should be registered");
689 ptn->set_escape_state(PointsToNode::GlobalEscape);
690 // Add edge to object for unsafe access with offset.
691 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
692 assert(adr_ptn != NULL, "node should be registered");
693 if (adr_ptn->is_Field()) {
694 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
695 add_edge(adr_ptn, ptn);
696 }
697 break;
698 }
699 ELSE_FAIL("Op_StoreP");
700 }
701 case Op_AryEq:
702 case Op_StrComp:
703 case Op_StrEquals:
704 case Op_StrIndexOf: {
705 // char[] arrays passed to string intrinsic do not escape but
706 // they are not scalar replaceable. Adjust escape state for them.
707 // Start from in(2) edge since in(1) is memory edge.
708 for (uint i = 2; i < n->req(); i++) {
709 Node* adr = n->in(i);
710 const Type* at = _igvn->type(adr);
711 if (!adr->is_top() && at->isa_ptr()) {
712 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
713 at->isa_ptr() != NULL, "expecting a pointer");
714 if (adr->is_AddP()) {
715 adr = get_addp_base(adr);
716 }
717 PointsToNode* ptn = ptnode_adr(adr->_idx);
718 assert(ptn != NULL, "node should be registered");
719 add_edge(n_ptn, ptn);
720 }
721 }
722 break;
723 }
724 default: {
725 // This method should be called only for EA specific nodes which may
726 // miss some edges when they were created.
727 #ifdef ASSERT
728 n->dump(1);
729 #endif
730 guarantee(false, "unknown node");
731 }
732 }
733 return;
734 }
735
736 void ConnectionGraph::add_call_node(CallNode* call) {
737 assert(call->returns_pointer(), "only for call which returns pointer");
738 uint call_idx = call->_idx;
739 if (call->is_Allocate()) {
740 Node* k = call->in(AllocateNode::KlassNode);
741 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
742 assert(kt != NULL, "TypeKlassPtr required.");
743 ciKlass* cik = kt->klass();
744 PointsToNode::EscapeState es = PointsToNode::NoEscape;
745 bool scalar_replaceable = true;
746 if (call->is_AllocateArray()) {
747 if (!cik->is_array_klass()) { // StressReflectiveCode
748 es = PointsToNode::GlobalEscape;
749 } else {
750 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
751 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
752 // Not scalar replaceable if the length is not constant or too big.
753 scalar_replaceable = false;
754 }
755 }
756 } else { // Allocate instance
757 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
758 !cik->is_instance_klass() || // StressReflectiveCode
759 cik->as_instance_klass()->has_finalizer()) {
760 es = PointsToNode::GlobalEscape;
761 }
762 }
763 add_java_object(call, es);
764 PointsToNode* ptn = ptnode_adr(call_idx);
765 if (!scalar_replaceable && ptn->scalar_replaceable()) {
766 ptn->set_scalar_replaceable(false);
767 }
768 } else if (call->is_CallStaticJava()) {
769 // Call nodes could be different types:
770 //
771 // 1. CallDynamicJavaNode (what happened during call is unknown):
772 //
773 // - mapped to GlobalEscape JavaObject node if oop is returned;
774 //
775 // - all oop arguments are escaping globally;
776 //
777 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
778 //
779 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
780 //
781 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
782 // - mapped to NoEscape JavaObject node if non-escaping object allocated
783 // during call is returned;
784 // - mapped to ArgEscape LocalVar node pointed to object arguments
785 // which are returned and does not escape during call;
786 //
787 // - oop arguments escaping status is defined by bytecode analysis;
788 //
789 // For a static call, we know exactly what method is being called.
790 // Use bytecode estimator to record whether the call's return value escapes.
791 ciMethod* meth = call->as_CallJava()->method();
792 if (meth == NULL) {
793 const char* name = call->as_CallStaticJava()->_name;
794 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
795 // Returns a newly allocated unescaped object.
796 add_java_object(call, PointsToNode::NoEscape);
797 ptnode_adr(call_idx)->set_scalar_replaceable(false);
798 } else {
799 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
800 call_analyzer->copy_dependencies(_compile->dependencies());
801 if (call_analyzer->is_return_allocated()) {
802 // Returns a newly allocated unescaped object, simply
803 // update dependency information.
804 // Mark it as NoEscape so that objects referenced by
805 // it's fields will be marked as NoEscape at least.
806 add_java_object(call, PointsToNode::NoEscape);
807 ptnode_adr(call_idx)->set_scalar_replaceable(false);
808 } else {
809 // Determine whether any arguments are returned.
810 const TypeTuple* d = call->tf()->domain();
811 bool ret_arg = false;
812 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
813 if (d->field_at(i)->isa_ptr() != NULL &&
814 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
815 ret_arg = true;
816 break;
817 }
818 }
819 if (ret_arg) {
820 add_local_var(call, PointsToNode::ArgEscape);
821 } else {
822 // Returns unknown object.
823 map_ideal_node(call, phantom_obj);
824 }
825 }
826 }
827 } else {
828 // An other type of call, assume the worst case:
829 // returned value is unknown and globally escapes.
830 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
831 map_ideal_node(call, phantom_obj);
832 }
833 }
834
835 void ConnectionGraph::process_call_arguments(CallNode *call) {
836 bool is_arraycopy = false;
837 switch (call->Opcode()) {
838 #ifdef ASSERT
839 case Op_Allocate:
840 case Op_AllocateArray:
841 case Op_Lock:
842 case Op_Unlock:
843 assert(false, "should be done already");
844 break;
845 #endif
846 case Op_CallLeafNoFP:
847 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
848 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
849 // fall through
850 case Op_CallLeaf: {
851 // Stub calls, objects do not escape but they are not scale replaceable.
852 // Adjust escape state for outgoing arguments.
853 const TypeTuple * d = call->tf()->domain();
854 bool src_has_oops = false;
855 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
856 const Type* at = d->field_at(i);
857 Node *arg = call->in(i);
858 const Type *aat = _igvn->type(arg);
859 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
860 continue;
861 if (arg->is_AddP()) {
862 //
863 // The inline_native_clone() case when the arraycopy stub is called
864 // after the allocation before Initialize and CheckCastPP nodes.
865 // Or normal arraycopy for object arrays case.
866 //
867 // Set AddP's base (Allocate) as not scalar replaceable since
868 // pointer to the base (with offset) is passed as argument.
869 //
870 arg = get_addp_base(arg);
871 }
872 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
873 assert(arg_ptn != NULL, "should be registered");
874 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
875 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
876 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
877 aat->isa_ptr() != NULL, "expecting an Ptr");
878 bool arg_has_oops = aat->isa_oopptr() &&
879 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
880 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
881 if (i == TypeFunc::Parms) {
882 src_has_oops = arg_has_oops;
883 }
884 //
885 // src or dst could be j.l.Object when other is basic type array:
886 //
887 // arraycopy(char[],0,Object*,0,size);
888 // arraycopy(Object*,0,char[],0,size);
889 //
890 // Don't add edges in such cases.
891 //
892 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
893 arg_has_oops && (i > TypeFunc::Parms);
894 #ifdef ASSERT
895 if (!(is_arraycopy ||
896 (call->as_CallLeaf()->_name != NULL &&
897 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
898 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
899 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
900 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
901 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
902 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0)
903 ))) {
904 call->dump();
905 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
906 }
907 #endif
908 // Always process arraycopy's destination object since
909 // we need to add all possible edges to references in
910 // source object.
911 if (arg_esc >= PointsToNode::ArgEscape &&
912 !arg_is_arraycopy_dest) {
913 continue;
914 }
915 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
916 if (arg_is_arraycopy_dest) {
917 Node* src = call->in(TypeFunc::Parms);
918 if (src->is_AddP()) {
919 src = get_addp_base(src);
920 }
921 PointsToNode* src_ptn = ptnode_adr(src->_idx);
922 assert(src_ptn != NULL, "should be registered");
923 if (arg_ptn != src_ptn) {
924 // Special arraycopy edge:
925 // A destination object's field can't have the source object
926 // as base since objects escape states are not related.
927 // Only escape state of destination object's fields affects
928 // escape state of fields in source object.
929 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
930 }
931 }
932 }
933 }
934 break;
935 }
936 case Op_CallStaticJava: {
937 // For a static call, we know exactly what method is being called.
938 // Use bytecode estimator to record the call's escape affects
939 #ifdef ASSERT
940 const char* name = call->as_CallStaticJava()->_name;
941 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
942 #endif
943 ciMethod* meth = call->as_CallJava()->method();
944 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
945 // fall-through if not a Java method or no analyzer information
946 if (call_analyzer != NULL) {
947 PointsToNode* call_ptn = ptnode_adr(call->_idx);
948 const TypeTuple* d = call->tf()->domain();
949 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
950 const Type* at = d->field_at(i);
951 int k = i - TypeFunc::Parms;
952 Node* arg = call->in(i);
953 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
954 if (at->isa_ptr() != NULL &&
955 call_analyzer->is_arg_returned(k)) {
956 // The call returns arguments.
957 if (call_ptn != NULL) { // Is call's result used?
958 assert(call_ptn->is_LocalVar(), "node should be registered");
959 assert(arg_ptn != NULL, "node should be registered");
960 add_edge(call_ptn, arg_ptn);
961 }
962 }
963 if (at->isa_oopptr() != NULL &&
964 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
965 if (!call_analyzer->is_arg_stack(k)) {
966 // The argument global escapes
967 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
968 } else {
969 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
970 if (!call_analyzer->is_arg_local(k)) {
971 // The argument itself doesn't escape, but any fields might
972 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
973 }
974 }
975 }
976 }
977 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
978 // The call returns arguments.
979 assert(call_ptn->edge_count() > 0, "sanity");
980 if (!call_analyzer->is_return_local()) {
981 // Returns also unknown object.
982 add_edge(call_ptn, phantom_obj);
983 }
984 }
985 break;
986 }
987 }
988 default: {
989 // Fall-through here if not a Java method or no analyzer information
990 // or some other type of call, assume the worst case: all arguments
991 // globally escape.
992 const TypeTuple* d = call->tf()->domain();
993 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
994 const Type* at = d->field_at(i);
995 if (at->isa_oopptr() != NULL) {
996 Node* arg = call->in(i);
997 if (arg->is_AddP()) {
998 arg = get_addp_base(arg);
999 }
1000 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1001 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1002 }
1003 }
1004 }
1005 }
1006 }
1007
1008
1009 // Finish Graph construction.
1010 bool ConnectionGraph::complete_connection_graph(
1011 GrowableArray<PointsToNode*>& ptnodes_worklist,
1012 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1013 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1014 GrowableArray<FieldNode*>& oop_fields_worklist) {
1015 // Normally only 1-3 passes needed to build Connection Graph depending
1016 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1017 // Set limit to 20 to catch situation when something did go wrong and
1018 // bailout Escape Analysis.
1019 // Also limit build time to 30 sec (60 in debug VM).
1020 #define CG_BUILD_ITER_LIMIT 20
1021 #ifdef ASSERT
1022 #define CG_BUILD_TIME_LIMIT 60.0
1023 #else
1024 #define CG_BUILD_TIME_LIMIT 30.0
1025 #endif
1026
1027 // Propagate GlobalEscape and ArgEscape escape states and check that
1028 // we still have non-escaping objects. The method pushs on _worklist
1029 // Field nodes which reference phantom_object.
1030 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1031 return false; // Nothing to do.
1032 }
1033 // Now propagate references to all JavaObject nodes.
1034 int java_objects_length = java_objects_worklist.length();
1035 elapsedTimer time;
1036 int new_edges = 1;
1037 int iterations = 0;
1038 do {
1039 while ((new_edges > 0) &&
1040 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1041 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1042 time.start();
1043 new_edges = 0;
1044 // Propagate references to phantom_object for nodes pushed on _worklist
1045 // by find_non_escaped_objects() and find_field_value().
1046 new_edges += add_java_object_edges(phantom_obj, false);
1047 for (int next = 0; next < java_objects_length; ++next) {
1048 JavaObjectNode* ptn = java_objects_worklist.at(next);
1049 new_edges += add_java_object_edges(ptn, true);
1050 }
1051 if (new_edges > 0) {
1052 // Update escape states on each iteration if graph was updated.
1053 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1054 return false; // Nothing to do.
1055 }
1056 }
1057 time.stop();
1058 }
1059 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1060 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1061 time.start();
1062 // Find fields which have unknown value.
1063 int fields_length = oop_fields_worklist.length();
1064 for (int next = 0; next < fields_length; next++) {
1065 FieldNode* field = oop_fields_worklist.at(next);
1066 if (field->edge_count() == 0) {
1067 new_edges += find_field_value(field);
1068 // This code may added new edges to phantom_object.
1069 // Need an other cycle to propagate references to phantom_object.
1070 }
1071 }
1072 time.stop();
1073 } else {
1074 new_edges = 0; // Bailout
1075 }
1076 } while (new_edges > 0);
1077
1078 // Bailout if passed limits.
1079 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1080 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1081 Compile* C = _compile;
1082 if (C->log() != NULL) {
1083 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1084 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1085 C->log()->end_elem(" limit'");
1086 }
1087 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1088 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1089 // Possible infinite build_connection_graph loop,
1090 // bailout (no changes to ideal graph were made).
1091 return false;
1092 }
1093 #ifdef ASSERT
1094 if (Verbose && PrintEscapeAnalysis) {
1095 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1096 iterations, nodes_size(), ptnodes_worklist.length());
1097 }
1098 #endif
1099
1100 #undef CG_BUILD_ITER_LIMIT
1101 #undef CG_BUILD_TIME_LIMIT
1102
1103 // Find fields initialized by NULL for non-escaping Allocations.
1104 int non_escaped_length = non_escaped_worklist.length();
1105 for (int next = 0; next < non_escaped_length; next++) {
1106 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1107 PointsToNode::EscapeState es = ptn->escape_state();
1108 assert(es <= PointsToNode::ArgEscape, "sanity");
1109 if (es == PointsToNode::NoEscape) {
1110 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1111 // Adding references to NULL object does not change escape states
1112 // since it does not escape. Also no fields are added to NULL object.
1113 add_java_object_edges(null_obj, false);
1114 }
1115 }
1116 Node* n = ptn->ideal_node();
1117 if (n->is_Allocate()) {
1118 // The object allocated by this Allocate node will never be
1119 // seen by an other thread. Mark it so that when it is
1120 // expanded no MemBarStoreStore is added.
1121 InitializeNode* ini = n->as_Allocate()->initialization();
1122 if (ini != NULL)
1123 ini->set_does_not_escape();
1124 }
1125 }
1126 return true; // Finished graph construction.
1127 }
1128
1129 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1130 // and check that we still have non-escaping java objects.
1131 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1132 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1133 GrowableArray<PointsToNode*> escape_worklist;
1134 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1135 int ptnodes_length = ptnodes_worklist.length();
1136 for (int next = 0; next < ptnodes_length; ++next) {
1137 PointsToNode* ptn = ptnodes_worklist.at(next);
1138 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1139 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1140 escape_worklist.push(ptn);
1141 }
1142 }
1143 // Set escape states to referenced nodes (edges list).
1144 while (escape_worklist.length() > 0) {
1145 PointsToNode* ptn = escape_worklist.pop();
1146 PointsToNode::EscapeState es = ptn->escape_state();
1147 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1148 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1149 es >= PointsToNode::ArgEscape) {
1150 // GlobalEscape or ArgEscape state of field means it has unknown value.
1151 if (add_edge(ptn, phantom_obj)) {
1152 // New edge was added
1153 add_field_uses_to_worklist(ptn->as_Field());
1154 }
1155 }
1156 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1157 PointsToNode* e = i.get();
1158 if (e->is_Arraycopy()) {
1159 assert(ptn->arraycopy_dst(), "sanity");
1160 // Propagate only fields escape state through arraycopy edge.
1161 if (e->fields_escape_state() < field_es) {
1162 set_fields_escape_state(e, field_es);
1163 escape_worklist.push(e);
1164 }
1165 } else if (es >= field_es) {
1166 // fields_escape_state is also set to 'es' if it is less than 'es'.
1167 if (e->escape_state() < es) {
1168 set_escape_state(e, es);
1169 escape_worklist.push(e);
1170 }
1171 } else {
1172 // Propagate field escape state.
1173 bool es_changed = false;
1174 if (e->fields_escape_state() < field_es) {
1175 set_fields_escape_state(e, field_es);
1176 es_changed = true;
1177 }
1178 if ((e->escape_state() < field_es) &&
1179 e->is_Field() && ptn->is_JavaObject() &&
1180 e->as_Field()->is_oop()) {
1181 // Change escape state of referenced fileds.
1182 set_escape_state(e, field_es);
1183 es_changed = true;;
1184 } else if (e->escape_state() < es) {
1185 set_escape_state(e, es);
1186 es_changed = true;;
1187 }
1188 if (es_changed) {
1189 escape_worklist.push(e);
1190 }
1191 }
1192 }
1193 }
1194 // Remove escaped objects from non_escaped list.
1195 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1196 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1197 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1198 non_escaped_worklist.delete_at(next);
1199 }
1200 if (ptn->escape_state() == PointsToNode::NoEscape) {
1201 // Find fields in non-escaped allocations which have unknown value.
1202 find_init_values(ptn, phantom_obj, NULL);
1203 }
1204 }
1205 return (non_escaped_worklist.length() > 0);
1206 }
1207
1208 // Add all references to JavaObject node by walking over all uses.
1209 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1210 int new_edges = 0;
1211 if (populate_worklist) {
1212 // Populate _worklist by uses of jobj's uses.
1213 for (UseIterator i(jobj); i.has_next(); i.next()) {
1214 PointsToNode* use = i.get();
1215 if (use->is_Arraycopy())
1216 continue;
1217 add_uses_to_worklist(use);
1218 if (use->is_Field() && use->as_Field()->is_oop()) {
1219 // Put on worklist all field's uses (loads) and
1220 // related field nodes (same base and offset).
1221 add_field_uses_to_worklist(use->as_Field());
1222 }
1223 }
1224 }
1225 while(_worklist.length() > 0) {
1226 PointsToNode* use = _worklist.pop();
1227 if (PointsToNode::is_base_use(use)) {
1228 // Add reference from jobj to field and from field to jobj (field's base).
1229 use = PointsToNode::get_use_node(use)->as_Field();
1230 if (add_base(use->as_Field(), jobj)) {
1231 new_edges++;
1232 }
1233 continue;
1234 }
1235 assert(!use->is_JavaObject(), "sanity");
1236 if (use->is_Arraycopy()) {
1237 if (jobj == null_obj) // NULL object does not have field edges
1238 continue;
1239 // Added edge from Arraycopy node to arraycopy's source java object
1240 if (add_edge(use, jobj)) {
1241 jobj->set_arraycopy_src();
1242 new_edges++;
1243 }
1244 // and stop here.
1245 continue;
1246 }
1247 if (!add_edge(use, jobj))
1248 continue; // No new edge added, there was such edge already.
1249 new_edges++;
1250 if (use->is_LocalVar()) {
1251 add_uses_to_worklist(use);
1252 if (use->arraycopy_dst()) {
1253 for (EdgeIterator i(use); i.has_next(); i.next()) {
1254 PointsToNode* e = i.get();
1255 if (e->is_Arraycopy()) {
1256 if (jobj == null_obj) // NULL object does not have field edges
1257 continue;
1258 // Add edge from arraycopy's destination java object to Arraycopy node.
1259 if (add_edge(jobj, e)) {
1260 new_edges++;
1261 jobj->set_arraycopy_dst();
1262 }
1263 }
1264 }
1265 }
1266 } else {
1267 // Added new edge to stored in field values.
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 return new_edges;
1274 }
1275
1276 // Put on worklist all related field nodes.
1277 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1278 assert(field->is_oop(), "sanity");
1279 int offset = field->offset();
1280 add_uses_to_worklist(field);
1281 // Loop over all bases of this field and push on worklist Field nodes
1282 // with the same offset and base (since they may reference the same field).
1283 for (BaseIterator i(field); i.has_next(); i.next()) {
1284 PointsToNode* base = i.get();
1285 add_fields_to_worklist(field, base);
1286 // Check if the base was source object of arraycopy and go over arraycopy's
1287 // destination objects since values stored to a field of source object are
1288 // accessable by uses (loads) of fields of destination objects.
1289 if (base->arraycopy_src()) {
1290 for (UseIterator j(base); j.has_next(); j.next()) {
1291 PointsToNode* arycp = j.get();
1292 if (arycp->is_Arraycopy()) {
1293 for (UseIterator k(arycp); k.has_next(); k.next()) {
1294 PointsToNode* abase = k.get();
1295 if (abase->arraycopy_dst() && abase != base) {
1296 // Look for the same arracopy reference.
1297 add_fields_to_worklist(field, abase);
1298 }
1299 }
1300 }
1301 }
1302 }
1303 }
1304 }
1305
1306 // Put on worklist all related field nodes.
1307 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1308 int offset = field->offset();
1309 if (base->is_LocalVar()) {
1310 for (UseIterator j(base); j.has_next(); j.next()) {
1311 PointsToNode* f = j.get();
1312 if (PointsToNode::is_base_use(f)) { // Field
1313 f = PointsToNode::get_use_node(f);
1314 if (f == field || !f->as_Field()->is_oop())
1315 continue;
1316 int offs = f->as_Field()->offset();
1317 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1318 add_to_worklist(f);
1319 }
1320 }
1321 }
1322 } else {
1323 assert(base->is_JavaObject(), "sanity");
1324 if (// Skip phantom_object since it is only used to indicate that
1325 // this field's content globally escapes.
1326 (base != phantom_obj) &&
1327 // NULL object node does not have fields.
1328 (base != null_obj)) {
1329 for (EdgeIterator i(base); i.has_next(); i.next()) {
1330 PointsToNode* f = i.get();
1331 // Skip arraycopy edge since store to destination object field
1332 // does not update value in source object field.
1333 if (f->is_Arraycopy()) {
1334 assert(base->arraycopy_dst(), "sanity");
1335 continue;
1336 }
1337 if (f == field || !f->as_Field()->is_oop())
1338 continue;
1339 int offs = f->as_Field()->offset();
1340 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1341 add_to_worklist(f);
1342 }
1343 }
1344 }
1345 }
1346 }
1347
1348 // Find fields which have unknown value.
1349 int ConnectionGraph::find_field_value(FieldNode* field) {
1350 // Escaped fields should have init value already.
1351 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1352 int new_edges = 0;
1353 for (BaseIterator i(field); i.has_next(); i.next()) {
1354 PointsToNode* base = i.get();
1355 if (base->is_JavaObject()) {
1356 // Skip Allocate's fields which will be processed later.
1357 if (base->ideal_node()->is_Allocate())
1358 return 0;
1359 assert(base == null_obj, "only NULL ptr base expected here");
1360 }
1361 }
1362 if (add_edge(field, phantom_obj)) {
1363 // New edge was added
1364 new_edges++;
1365 add_field_uses_to_worklist(field);
1366 }
1367 return new_edges;
1368 }
1369
1370 // Find fields initializing values for allocations.
1371 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1372 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1373 int new_edges = 0;
1374 Node* alloc = pta->ideal_node();
1375 if (init_val == phantom_obj) {
1376 // Do nothing for Allocate nodes since its fields values are "known".
1377 if (alloc->is_Allocate())
1378 return 0;
1379 assert(alloc->as_CallStaticJava(), "sanity");
1380 #ifdef ASSERT
1381 if (alloc->as_CallStaticJava()->method() == NULL) {
1382 const char* name = alloc->as_CallStaticJava()->_name;
1383 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1384 }
1385 #endif
1386 // Non-escaped allocation returned from Java or runtime call have
1387 // unknown values in fields.
1388 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1389 PointsToNode* field = i.get();
1390 if (field->is_Field() && field->as_Field()->is_oop()) {
1391 if (add_edge(field, phantom_obj)) {
1392 // New edge was added
1393 new_edges++;
1394 add_field_uses_to_worklist(field->as_Field());
1395 }
1396 }
1397 }
1398 return new_edges;
1399 }
1400 assert(init_val == null_obj, "sanity");
1401 // Do nothing for Call nodes since its fields values are unknown.
1402 if (!alloc->is_Allocate())
1403 return 0;
1404
1405 InitializeNode* ini = alloc->as_Allocate()->initialization();
1406 Compile* C = _compile;
1407 bool visited_bottom_offset = false;
1408 GrowableArray<int> offsets_worklist;
1409
1410 // Check if an oop field's initializing value is recorded and add
1411 // a corresponding NULL if field's value if it is not recorded.
1412 // Connection Graph does not record a default initialization by NULL
1413 // captured by Initialize node.
1414 //
1415 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1416 PointsToNode* field = i.get(); // Field (AddP)
1417 if (!field->is_Field() || !field->as_Field()->is_oop())
1418 continue; // Not oop field
1419 int offset = field->as_Field()->offset();
1420 if (offset == Type::OffsetBot) {
1421 if (!visited_bottom_offset) {
1422 // OffsetBot is used to reference array's element,
1423 // always add reference to NULL to all Field nodes since we don't
1424 // known which element is referenced.
1425 if (add_edge(field, null_obj)) {
1426 // New edge was added
1427 new_edges++;
1428 add_field_uses_to_worklist(field->as_Field());
1429 visited_bottom_offset = true;
1430 }
1431 }
1432 } else {
1433 // Check only oop fields.
1434 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1435 if (adr_type->isa_rawptr()) {
1436 #ifdef ASSERT
1437 // Raw pointers are used for initializing stores so skip it
1438 // since it should be recorded already
1439 Node* base = get_addp_base(field->ideal_node());
1440 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1441 (base->in(0) == alloc),"unexpected pointer type");
1442 #endif
1443 continue;
1444 }
1445 if (!offsets_worklist.contains(offset)) {
1446 offsets_worklist.append(offset);
1447 Node* value = NULL;
1448 if (ini != NULL) {
1449 // StoreP::memory_type() == T_ADDRESS
1450 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1451 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1452 // Make sure initializing store has the same type as this AddP.
1453 // This AddP may reference non existing field because it is on a
1454 // dead branch of bimorphic call which is not eliminated yet.
1455 if (store != NULL && store->is_Store() &&
1456 store->as_Store()->memory_type() == ft) {
1457 value = store->in(MemNode::ValueIn);
1458 #ifdef ASSERT
1459 if (VerifyConnectionGraph) {
1460 // Verify that AddP already points to all objects the value points to.
1461 PointsToNode* val = ptnode_adr(value->_idx);
1462 assert((val != NULL), "should be processed already");
1463 PointsToNode* missed_obj = NULL;
1464 if (val->is_JavaObject()) {
1465 if (!field->points_to(val->as_JavaObject())) {
1466 missed_obj = val;
1467 }
1468 } else {
1469 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1470 tty->print_cr("----------init store has invalid value -----");
1471 store->dump();
1472 val->dump();
1473 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1474 }
1475 for (EdgeIterator j(val); j.has_next(); j.next()) {
1476 PointsToNode* obj = j.get();
1477 if (obj->is_JavaObject()) {
1478 if (!field->points_to(obj->as_JavaObject())) {
1479 missed_obj = obj;
1480 break;
1481 }
1482 }
1483 }
1484 }
1485 if (missed_obj != NULL) {
1486 tty->print_cr("----------field---------------------------------");
1487 field->dump();
1488 tty->print_cr("----------missed referernce to object-----------");
1489 missed_obj->dump();
1490 tty->print_cr("----------object referernced by init store -----");
1491 store->dump();
1492 val->dump();
1493 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1494 }
1495 }
1496 #endif
1497 } else {
1498 // There could be initializing stores which follow allocation.
1499 // For example, a volatile field store is not collected
1500 // by Initialize node.
1501 //
1502 // Need to check for dependent loads to separate such stores from
1503 // stores which follow loads. For now, add initial value NULL so
1504 // that compare pointers optimization works correctly.
1505 }
1506 }
1507 if (value == NULL) {
1508 // A field's initializing value was not recorded. Add NULL.
1509 if (add_edge(field, null_obj)) {
1510 // New edge was added
1511 new_edges++;
1512 add_field_uses_to_worklist(field->as_Field());
1513 }
1514 }
1515 }
1516 }
1517 }
1518 return new_edges;
1519 }
1520
1521 // Adjust scalar_replaceable state after Connection Graph is built.
1522 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1523 // Search for non-escaping objects which are not scalar replaceable
1524 // and mark them to propagate the state to referenced objects.
1525
1526 // 1. An object is not scalar replaceable if the field into which it is
1527 // stored has unknown offset (stored into unknown element of an array).
1528 //
1529 for (UseIterator i(jobj); i.has_next(); i.next()) {
1530 PointsToNode* use = i.get();
1531 assert(!use->is_Arraycopy(), "sanity");
1532 if (use->is_Field()) {
1533 FieldNode* field = use->as_Field();
1534 assert(field->is_oop() && field->scalar_replaceable() &&
1535 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1536 if (field->offset() == Type::OffsetBot) {
1537 jobj->set_scalar_replaceable(false);
1538 return;
1539 }
1540 }
1541 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1542 // 2. An object is not scalar replaceable if it is merged with other objects.
1543 for (EdgeIterator j(use); j.has_next(); j.next()) {
1544 PointsToNode* ptn = j.get();
1545 if (ptn->is_JavaObject() && ptn != jobj) {
1546 // Mark all objects.
1547 jobj->set_scalar_replaceable(false);
1548 ptn->set_scalar_replaceable(false);
1549 }
1550 }
1551 if (!jobj->scalar_replaceable()) {
1552 return;
1553 }
1554 }
1555
1556 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1557 // Non-escaping object node should point only to field nodes.
1558 FieldNode* field = j.get()->as_Field();
1559 int offset = field->as_Field()->offset();
1560
1561 // 3. An object is not scalar replaceable if it has a field with unknown
1562 // offset (array's element is accessed in loop).
1563 if (offset == Type::OffsetBot) {
1564 jobj->set_scalar_replaceable(false);
1565 return;
1566 }
1567 // 4. Currently an object is not scalar replaceable if a LoadStore node
1568 // access its field since the field value is unknown after it.
1569 //
1570 Node* n = field->ideal_node();
1571 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1572 if (n->fast_out(i)->is_LoadStore()) {
1573 jobj->set_scalar_replaceable(false);
1574 return;
1575 }
1576 }
1577
1578 // 5. Or the address may point to more then one object. This may produce
1579 // the false positive result (set not scalar replaceable)
1580 // since the flow-insensitive escape analysis can't separate
1581 // the case when stores overwrite the field's value from the case
1582 // when stores happened on different control branches.
1583 //
1584 // Note: it will disable scalar replacement in some cases:
1585 //
1586 // Point p[] = new Point[1];
1587 // p[0] = new Point(); // Will be not scalar replaced
1588 //
1589 // but it will save us from incorrect optimizations in next cases:
1590 //
1591 // Point p[] = new Point[1];
1592 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1593 //
1594 if (field->base_count() > 1) {
1595 for (BaseIterator i(field); i.has_next(); i.next()) {
1596 PointsToNode* base = i.get();
1597 // Don't take into account LocalVar nodes which
1598 // may point to only one object which should be also
1599 // this field's base by now.
1600 if (base->is_JavaObject() && base != jobj) {
1601 // Mark all bases.
1602 jobj->set_scalar_replaceable(false);
1603 base->set_scalar_replaceable(false);
1604 }
1605 }
1606 }
1607 }
1608 }
1609
1610 #ifdef ASSERT
1611 void ConnectionGraph::verify_connection_graph(
1612 GrowableArray<PointsToNode*>& ptnodes_worklist,
1613 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1614 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1615 GrowableArray<Node*>& addp_worklist) {
1616 // Verify that graph is complete - no new edges could be added.
1617 int java_objects_length = java_objects_worklist.length();
1618 int non_escaped_length = non_escaped_worklist.length();
1619 int new_edges = 0;
1620 for (int next = 0; next < java_objects_length; ++next) {
1621 JavaObjectNode* ptn = java_objects_worklist.at(next);
1622 new_edges += add_java_object_edges(ptn, true);
1623 }
1624 assert(new_edges == 0, "graph was not complete");
1625 // Verify that escape state is final.
1626 int length = non_escaped_worklist.length();
1627 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1628 assert((non_escaped_length == non_escaped_worklist.length()) &&
1629 (non_escaped_length == length) &&
1630 (_worklist.length() == 0), "escape state was not final");
1631
1632 // Verify fields information.
1633 int addp_length = addp_worklist.length();
1634 for (int next = 0; next < addp_length; ++next ) {
1635 Node* n = addp_worklist.at(next);
1636 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1637 if (field->is_oop()) {
1638 // Verify that field has all bases
1639 Node* base = get_addp_base(n);
1640 PointsToNode* ptn = ptnode_adr(base->_idx);
1641 if (ptn->is_JavaObject()) {
1642 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1643 } else {
1644 assert(ptn->is_LocalVar(), "sanity");
1645 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1646 PointsToNode* e = i.get();
1647 if (e->is_JavaObject()) {
1648 assert(field->has_base(e->as_JavaObject()), "sanity");
1649 }
1650 }
1651 }
1652 // Verify that all fields have initializing values.
1653 if (field->edge_count() == 0) {
1654 tty->print_cr("----------field does not have references----------");
1655 field->dump();
1656 for (BaseIterator i(field); i.has_next(); i.next()) {
1657 PointsToNode* base = i.get();
1658 tty->print_cr("----------field has next base---------------------");
1659 base->dump();
1660 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1661 tty->print_cr("----------base has fields-------------------------");
1662 for (EdgeIterator j(base); j.has_next(); j.next()) {
1663 j.get()->dump();
1664 }
1665 tty->print_cr("----------base has references---------------------");
1666 for (UseIterator j(base); j.has_next(); j.next()) {
1667 j.get()->dump();
1668 }
1669 }
1670 }
1671 for (UseIterator i(field); i.has_next(); i.next()) {
1672 i.get()->dump();
1673 }
1674 assert(field->edge_count() > 0, "sanity");
1675 }
1676 }
1677 }
1678 }
1679 #endif
1680
1681 // Optimize ideal graph.
1682 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1683 GrowableArray<Node*>& storestore_worklist) {
1684 Compile* C = _compile;
1685 PhaseIterGVN* igvn = _igvn;
1686 if (EliminateLocks) {
1687 // Mark locks before changing ideal graph.
1688 int cnt = C->macro_count();
1689 for( int i=0; i < cnt; i++ ) {
1690 Node *n = C->macro_node(i);
1691 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1692 AbstractLockNode* alock = n->as_AbstractLock();
1693 if (!alock->is_non_esc_obj()) {
1694 if (not_global_escape(alock->obj_node())) {
1695 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1696 // The lock could be marked eliminated by lock coarsening
1697 // code during first IGVN before EA. Replace coarsened flag
1698 // to eliminate all associated locks/unlocks.
1699 alock->set_non_esc_obj();
1700 }
1701 }
1702 }
1703 }
1704 }
1705
1706 if (OptimizePtrCompare) {
1707 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1708 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1709 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1710 // Optimize objects compare.
1711 while (ptr_cmp_worklist.length() != 0) {
1712 Node *n = ptr_cmp_worklist.pop();
1713 Node *res = optimize_ptr_compare(n);
1714 if (res != NULL) {
1715 #ifndef PRODUCT
1716 if (PrintOptimizePtrCompare) {
1717 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"));
1718 if (Verbose) {
1719 n->dump(1);
1720 }
1721 }
1722 #endif
1723 igvn->replace_node(n, res);
1724 }
1725 }
1726 // cleanup
1727 if (_pcmp_neq->outcnt() == 0)
1728 igvn->hash_delete(_pcmp_neq);
1729 if (_pcmp_eq->outcnt() == 0)
1730 igvn->hash_delete(_pcmp_eq);
1731 }
1732
1733 // For MemBarStoreStore nodes added in library_call.cpp, check
1734 // escape status of associated AllocateNode and optimize out
1735 // MemBarStoreStore node if the allocated object never escapes.
1736 while (storestore_worklist.length() != 0) {
1737 Node *n = storestore_worklist.pop();
1738 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1739 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1740 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1741 if (not_global_escape(alloc)) {
1742 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1743 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1744 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1745 igvn->register_new_node_with_optimizer(mb);
1746 igvn->replace_node(storestore, mb);
1747 }
1748 }
1749 }
1750
1751 // Optimize objects compare.
1752 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1753 assert(OptimizePtrCompare, "sanity");
1754 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1755 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1756 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1757 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1758 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1759 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1760
1761 // Check simple cases first.
1762 if (jobj1 != NULL) {
1763 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1764 if (jobj1 == jobj2) {
1765 // Comparing the same not escaping object.
1766 return _pcmp_eq;
1767 }
1768 Node* obj = jobj1->ideal_node();
1769 // Comparing not escaping allocation.
1770 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1771 !ptn2->points_to(jobj1)) {
1772 return _pcmp_neq; // This includes nullness check.
1773 }
1774 }
1775 }
1776 if (jobj2 != NULL) {
1777 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1778 Node* obj = jobj2->ideal_node();
1779 // Comparing not escaping allocation.
1780 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1781 !ptn1->points_to(jobj2)) {
1782 return _pcmp_neq; // This includes nullness check.
1783 }
1784 }
1785 }
1786 if (jobj1 != NULL && jobj1 != phantom_obj &&
1787 jobj2 != NULL && jobj2 != phantom_obj &&
1788 jobj1->ideal_node()->is_Con() &&
1789 jobj2->ideal_node()->is_Con()) {
1790 // Klass or String constants compare. Need to be careful with
1791 // compressed pointers - compare types of ConN and ConP instead of nodes.
1792 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1793 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1794 if (t1->make_ptr() == t2->make_ptr()) {
1795 return _pcmp_eq;
1796 } else {
1797 return _pcmp_neq;
1798 }
1799 }
1800 if (ptn1->meet(ptn2)) {
1801 return NULL; // Sets are not disjoint
1802 }
1803
1804 // Sets are disjoint.
1805 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1806 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1807 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1808 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1809 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1810 set2_has_unknown_ptr && set1_has_null_ptr) {
1811 // Check nullness of unknown object.
1812 return NULL;
1813 }
1814
1815 // Disjointness by itself is not sufficient since
1816 // alias analysis is not complete for escaped objects.
1817 // Disjoint sets are definitely unrelated only when
1818 // at least one set has only not escaping allocations.
1819 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1820 if (ptn1->non_escaping_allocation()) {
1821 return _pcmp_neq;
1822 }
1823 }
1824 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1825 if (ptn2->non_escaping_allocation()) {
1826 return _pcmp_neq;
1827 }
1828 }
1829 return NULL;
1830 }
1831
1832 // Connection Graph constuction functions.
1833
1834 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1835 PointsToNode* ptadr = _nodes.at(n->_idx);
1836 if (ptadr != NULL) {
1837 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1838 return;
1839 }
1840 Compile* C = _compile;
1841 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1842 _nodes.at_put(n->_idx, ptadr);
1843 }
1844
1845 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1846 PointsToNode* ptadr = _nodes.at(n->_idx);
1847 if (ptadr != NULL) {
1848 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1849 return;
1850 }
1851 Compile* C = _compile;
1852 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1853 _nodes.at_put(n->_idx, ptadr);
1854 }
1855
1856 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1857 PointsToNode* ptadr = _nodes.at(n->_idx);
1858 if (ptadr != NULL) {
1859 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1860 return;
1861 }
1862 bool unsafe = false;
1863 bool is_oop = is_oop_field(n, offset, &unsafe);
1864 if (unsafe) {
1865 es = PointsToNode::GlobalEscape;
1866 }
1867 Compile* C = _compile;
1868 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1869 _nodes.at_put(n->_idx, field);
1870 }
1871
1872 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1873 PointsToNode* src, PointsToNode* dst) {
1874 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1875 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1876 PointsToNode* ptadr = _nodes.at(n->_idx);
1877 if (ptadr != NULL) {
1878 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1879 return;
1880 }
1881 Compile* C = _compile;
1882 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1883 _nodes.at_put(n->_idx, ptadr);
1884 // Add edge from arraycopy node to source object.
1885 (void)add_edge(ptadr, src);
1886 src->set_arraycopy_src();
1887 // Add edge from destination object to arraycopy node.
1888 (void)add_edge(dst, ptadr);
1889 dst->set_arraycopy_dst();
1890 }
1891
1892 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1893 const Type* adr_type = n->as_AddP()->bottom_type();
1894 BasicType bt = T_INT;
1895 if (offset == Type::OffsetBot) {
1896 // Check only oop fields.
1897 if (!adr_type->isa_aryptr() ||
1898 (adr_type->isa_aryptr()->klass() == NULL) ||
1899 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1900 // OffsetBot is used to reference array's element. Ignore first AddP.
1901 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1902 bt = T_OBJECT;
1903 }
1904 }
1905 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1906 if (adr_type->isa_instptr()) {
1907 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1908 if (field != NULL) {
1909 bt = field->layout_type();
1910 } else {
1911 // Check for unsafe oop field access
1912 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1913 int opcode = n->fast_out(i)->Opcode();
1914 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1915 opcode == Op_StoreN || opcode == Op_LoadN) {
1916 bt = T_OBJECT;
1917 (*unsafe) = true;
1918 break;
1919 }
1920 }
1921 }
1922 } else if (adr_type->isa_aryptr()) {
1923 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1924 // Ignore array length load.
1925 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1926 // Ignore first AddP.
1927 } else {
1928 const Type* elemtype = adr_type->isa_aryptr()->elem();
1929 bt = elemtype->array_element_basic_type();
1930 }
1931 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1932 // Allocation initialization, ThreadLocal field access, unsafe access
1933 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1934 int opcode = n->fast_out(i)->Opcode();
1935 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1936 opcode == Op_StoreN || opcode == Op_LoadN) {
1937 bt = T_OBJECT;
1938 break;
1939 }
1940 }
1941 }
1942 }
1943 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1944 }
1945
1946 // Returns unique pointed java object or NULL.
1947 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1948 assert(!_collecting, "should not call when contructed graph");
1949 // If the node was created after the escape computation we can't answer.
1950 uint idx = n->_idx;
1951 if (idx >= nodes_size()) {
1952 return NULL;
1953 }
1954 PointsToNode* ptn = ptnode_adr(idx);
1955 if (ptn->is_JavaObject()) {
1956 return ptn->as_JavaObject();
1957 }
1958 assert(ptn->is_LocalVar(), "sanity");
1959 // Check all java objects it points to.
1960 JavaObjectNode* jobj = NULL;
1961 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1962 PointsToNode* e = i.get();
1963 if (e->is_JavaObject()) {
1964 if (jobj == NULL) {
1965 jobj = e->as_JavaObject();
1966 } else if (jobj != e) {
1967 return NULL;
1968 }
1969 }
1970 }
1971 return jobj;
1972 }
1973
1974 // Return true if this node points only to non-escaping allocations.
1975 bool PointsToNode::non_escaping_allocation() {
1976 if (is_JavaObject()) {
1977 Node* n = ideal_node();
1978 if (n->is_Allocate() || n->is_CallStaticJava()) {
1979 return (escape_state() == PointsToNode::NoEscape);
1980 } else {
1981 return false;
1982 }
1983 }
1984 assert(is_LocalVar(), "sanity");
1985 // Check all java objects it points to.
1986 for (EdgeIterator i(this); i.has_next(); i.next()) {
1987 PointsToNode* e = i.get();
1988 if (e->is_JavaObject()) {
1989 Node* n = e->ideal_node();
1990 if ((e->escape_state() != PointsToNode::NoEscape) ||
1991 !(n->is_Allocate() || n->is_CallStaticJava())) {
1992 return false;
1993 }
1994 }
1995 }
1996 return true;
1997 }
1998
1999 // Return true if we know the node does not escape globally.
2000 bool ConnectionGraph::not_global_escape(Node *n) {
2001 assert(!_collecting, "should not call during graph construction");
2002 // If the node was created after the escape computation we can't answer.
2003 uint idx = n->_idx;
2004 if (idx >= nodes_size()) {
2005 return false;
2006 }
2007 PointsToNode* ptn = ptnode_adr(idx);
2008 PointsToNode::EscapeState es = ptn->escape_state();
2009 // If we have already computed a value, return it.
2010 if (es >= PointsToNode::GlobalEscape)
2011 return false;
2012 if (ptn->is_JavaObject()) {
2013 return true; // (es < PointsToNode::GlobalEscape);
2014 }
2015 assert(ptn->is_LocalVar(), "sanity");
2016 // Check all java objects it points to.
2017 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2018 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2019 return false;
2020 }
2021 return true;
2022 }
2023
2024
2025 // Helper functions
2026
2027 // Return true if this node points to specified node or nodes it points to.
2028 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2029 if (is_JavaObject()) {
2030 return (this == ptn);
2031 }
2032 assert(is_LocalVar() || is_Field(), "sanity");
2033 for (EdgeIterator i(this); i.has_next(); i.next()) {
2034 if (i.get() == ptn)
2035 return true;
2036 }
2037 return false;
2038 }
2039
2040 // Return true if one node points to an other.
2041 bool PointsToNode::meet(PointsToNode* ptn) {
2042 if (this == ptn) {
2043 return true;
2044 } else if (ptn->is_JavaObject()) {
2045 return this->points_to(ptn->as_JavaObject());
2046 } else if (this->is_JavaObject()) {
2047 return ptn->points_to(this->as_JavaObject());
2048 }
2049 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2050 int ptn_count = ptn->edge_count();
2051 for (EdgeIterator i(this); i.has_next(); i.next()) {
2052 PointsToNode* this_e = i.get();
2053 for (int j = 0; j < ptn_count; j++) {
2054 if (this_e == ptn->edge(j))
2055 return true;
2056 }
2057 }
2058 return false;
2059 }
2060
2061 #ifdef ASSERT
2062 // Return true if bases point to this java object.
2063 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2064 for (BaseIterator i(this); i.has_next(); i.next()) {
2065 if (i.get() == jobj)
2066 return true;
2067 }
2068 return false;
2069 }
2070 #endif
2071
2072 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2073 const Type *adr_type = phase->type(adr);
2074 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2075 adr->in(AddPNode::Address)->is_Proj() &&
2076 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2077 // We are computing a raw address for a store captured by an Initialize
2078 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2079 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2080 assert(offs != Type::OffsetBot ||
2081 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2082 "offset must be a constant or it is initialization of array");
2083 return offs;
2084 }
2085 const TypePtr *t_ptr = adr_type->isa_ptr();
2086 assert(t_ptr != NULL, "must be a pointer type");
2087 return t_ptr->offset();
2088 }
2089
2090 Node* ConnectionGraph::get_addp_base(Node *addp) {
2091 assert(addp->is_AddP(), "must be AddP");
2092 //
2093 // AddP cases for Base and Address inputs:
2094 // case #1. Direct object's field reference:
2095 // Allocate
2096 // |
2097 // Proj #5 ( oop result )
2098 // |
2099 // CheckCastPP (cast to instance type)
2100 // | |
2101 // AddP ( base == address )
2102 //
2103 // case #2. Indirect object's field reference:
2104 // Phi
2105 // |
2106 // CastPP (cast to instance type)
2107 // | |
2108 // AddP ( base == address )
2109 //
2110 // case #3. Raw object's field reference for Initialize node:
2111 // Allocate
2112 // |
2113 // Proj #5 ( oop result )
2114 // top |
2115 // \ |
2116 // AddP ( base == top )
2117 //
2118 // case #4. Array's element reference:
2119 // {CheckCastPP | CastPP}
2120 // | | |
2121 // | AddP ( array's element offset )
2122 // | |
2123 // AddP ( array's offset )
2124 //
2125 // case #5. Raw object's field reference for arraycopy stub call:
2126 // The inline_native_clone() case when the arraycopy stub is called
2127 // after the allocation before Initialize and CheckCastPP nodes.
2128 // Allocate
2129 // |
2130 // Proj #5 ( oop result )
2131 // | |
2132 // AddP ( base == address )
2133 //
2134 // case #6. Constant Pool, ThreadLocal, CastX2P or
2135 // Raw object's field reference:
2136 // {ConP, ThreadLocal, CastX2P, raw Load}
2137 // top |
2138 // \ |
2139 // AddP ( base == top )
2140 //
2141 // case #7. Klass's field reference.
2142 // LoadKlass
2143 // | |
2144 // AddP ( base == address )
2145 //
2146 // case #8. narrow Klass's field reference.
2147 // LoadNKlass
2148 // |
2149 // DecodeN
2150 // | |
2151 // AddP ( base == address )
2152 //
2153 Node *base = addp->in(AddPNode::Base);
2154 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2155 base = addp->in(AddPNode::Address);
2156 while (base->is_AddP()) {
2157 // Case #6 (unsafe access) may have several chained AddP nodes.
2158 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2159 base = base->in(AddPNode::Address);
2160 }
2161 Node* uncast_base = base->uncast();
2162 int opcode = uncast_base->Opcode();
2163 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2164 opcode == Op_CastX2P || uncast_base->is_DecodeN() ||
2165 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
2166 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2167 }
2168 return base;
2169 }
2170
2171 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2172 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2173 Node* addp2 = addp->raw_out(0);
2174 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2175 addp2->in(AddPNode::Base) == n &&
2176 addp2->in(AddPNode::Address) == addp) {
2177 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2178 //
2179 // Find array's offset to push it on worklist first and
2180 // as result process an array's element offset first (pushed second)
2181 // to avoid CastPP for the array's offset.
2182 // Otherwise the inserted CastPP (LocalVar) will point to what
2183 // the AddP (Field) points to. Which would be wrong since
2184 // the algorithm expects the CastPP has the same point as
2185 // as AddP's base CheckCastPP (LocalVar).
2186 //
2187 // ArrayAllocation
2188 // |
2189 // CheckCastPP
2190 // |
2191 // memProj (from ArrayAllocation CheckCastPP)
2192 // | ||
2193 // | || Int (element index)
2194 // | || | ConI (log(element size))
2195 // | || | /
2196 // | || LShift
2197 // | || /
2198 // | AddP (array's element offset)
2199 // | |
2200 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2201 // | / /
2202 // AddP (array's offset)
2203 // |
2204 // Load/Store (memory operation on array's element)
2205 //
2206 return addp2;
2207 }
2208 return NULL;
2209 }
2210
2211 //
2212 // Adjust the type and inputs of an AddP which computes the
2213 // address of a field of an instance
2214 //
2215 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2216 PhaseGVN* igvn = _igvn;
2217 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2218 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2219 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2220 if (t == NULL) {
2221 // We are computing a raw address for a store captured by an Initialize
2222 // compute an appropriate address type (cases #3 and #5).
2223 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2224 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2225 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2226 assert(offs != Type::OffsetBot, "offset must be a constant");
2227 t = base_t->add_offset(offs)->is_oopptr();
2228 }
2229 int inst_id = base_t->instance_id();
2230 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2231 "old type must be non-instance or match new type");
2232
2233 // The type 't' could be subclass of 'base_t'.
2234 // As result t->offset() could be large then base_t's size and it will
2235 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2236 // constructor verifies correctness of the offset.
2237 //
2238 // It could happened on subclass's branch (from the type profiling
2239 // inlining) which was not eliminated during parsing since the exactness
2240 // of the allocation type was not propagated to the subclass type check.
2241 //
2242 // Or the type 't' could be not related to 'base_t' at all.
2243 // It could happened when CHA type is different from MDO type on a dead path
2244 // (for example, from instanceof check) which is not collapsed during parsing.
2245 //
2246 // Do nothing for such AddP node and don't process its users since
2247 // this code branch will go away.
2248 //
2249 if (!t->is_known_instance() &&
2250 !base_t->klass()->is_subtype_of(t->klass())) {
2251 return false; // bail out
2252 }
2253 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2254 // Do NOT remove the next line: ensure a new alias index is allocated
2255 // for the instance type. Note: C++ will not remove it since the call
2256 // has side effect.
2257 int alias_idx = _compile->get_alias_index(tinst);
2258 igvn->set_type(addp, tinst);
2259 // record the allocation in the node map
2260 set_map(addp, get_map(base->_idx));
2261 // Set addp's Base and Address to 'base'.
2262 Node *abase = addp->in(AddPNode::Base);
2263 Node *adr = addp->in(AddPNode::Address);
2264 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2265 adr->in(0)->_idx == (uint)inst_id) {
2266 // Skip AddP cases #3 and #5.
2267 } else {
2268 assert(!abase->is_top(), "sanity"); // AddP case #3
2269 if (abase != base) {
2270 igvn->hash_delete(addp);
2271 addp->set_req(AddPNode::Base, base);
2272 if (abase == adr) {
2273 addp->set_req(AddPNode::Address, base);
2274 } else {
2275 // AddP case #4 (adr is array's element offset AddP node)
2276 #ifdef ASSERT
2277 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2278 assert(adr->is_AddP() && atype != NULL &&
2279 atype->instance_id() == inst_id, "array's element offset should be processed first");
2280 #endif
2281 }
2282 igvn->hash_insert(addp);
2283 }
2284 }
2285 // Put on IGVN worklist since at least addp's type was changed above.
2286 record_for_optimizer(addp);
2287 return true;
2288 }
2289
2290 //
2291 // Create a new version of orig_phi if necessary. Returns either the newly
2292 // created phi or an existing phi. Sets create_new to indicate whether a new
2293 // phi was created. Cache the last newly created phi in the node map.
2294 //
2295 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2296 Compile *C = _compile;
2297 PhaseGVN* igvn = _igvn;
2298 new_created = false;
2299 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2300 // nothing to do if orig_phi is bottom memory or matches alias_idx
2301 if (phi_alias_idx == alias_idx) {
2302 return orig_phi;
2303 }
2304 // Have we recently created a Phi for this alias index?
2305 PhiNode *result = get_map_phi(orig_phi->_idx);
2306 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2307 return result;
2308 }
2309 // Previous check may fail when the same wide memory Phi was split into Phis
2310 // for different memory slices. Search all Phis for this region.
2311 if (result != NULL) {
2312 Node* region = orig_phi->in(0);
2313 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2314 Node* phi = region->fast_out(i);
2315 if (phi->is_Phi() &&
2316 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2317 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2318 return phi->as_Phi();
2319 }
2320 }
2321 }
2322 if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2323 if (C->do_escape_analysis() == true && !C->failing()) {
2324 // Retry compilation without escape analysis.
2325 // If this is the first failure, the sentinel string will "stick"
2326 // to the Compile object, and the C2Compiler will see it and retry.
2327 C->record_failure(C2Compiler::retry_no_escape_analysis());
2328 }
2329 return NULL;
2330 }
2331 orig_phi_worklist.append_if_missing(orig_phi);
2332 const TypePtr *atype = C->get_adr_type(alias_idx);
2333 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2334 C->copy_node_notes_to(result, orig_phi);
2335 igvn->set_type(result, result->bottom_type());
2336 record_for_optimizer(result);
2337 set_map(orig_phi, result);
2338 new_created = true;
2339 return result;
2340 }
2341
2342 //
2343 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2344 // specified alias index.
2345 //
2346 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2347 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2348 Compile *C = _compile;
2349 PhaseGVN* igvn = _igvn;
2350 bool new_phi_created;
2351 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2352 if (!new_phi_created) {
2353 return result;
2354 }
2355 GrowableArray<PhiNode *> phi_list;
2356 GrowableArray<uint> cur_input;
2357 PhiNode *phi = orig_phi;
2358 uint idx = 1;
2359 bool finished = false;
2360 while(!finished) {
2361 while (idx < phi->req()) {
2362 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2363 if (mem != NULL && mem->is_Phi()) {
2364 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2365 if (new_phi_created) {
2366 // found an phi for which we created a new split, push current one on worklist and begin
2367 // processing new one
2368 phi_list.push(phi);
2369 cur_input.push(idx);
2370 phi = mem->as_Phi();
2371 result = newphi;
2372 idx = 1;
2373 continue;
2374 } else {
2375 mem = newphi;
2376 }
2377 }
2378 if (C->failing()) {
2379 return NULL;
2380 }
2381 result->set_req(idx++, mem);
2382 }
2383 #ifdef ASSERT
2384 // verify that the new Phi has an input for each input of the original
2385 assert( phi->req() == result->req(), "must have same number of inputs.");
2386 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2387 #endif
2388 // Check if all new phi's inputs have specified alias index.
2389 // Otherwise use old phi.
2390 for (uint i = 1; i < phi->req(); i++) {
2391 Node* in = result->in(i);
2392 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2393 }
2394 // we have finished processing a Phi, see if there are any more to do
2395 finished = (phi_list.length() == 0 );
2396 if (!finished) {
2397 phi = phi_list.pop();
2398 idx = cur_input.pop();
2399 PhiNode *prev_result = get_map_phi(phi->_idx);
2400 prev_result->set_req(idx++, result);
2401 result = prev_result;
2402 }
2403 }
2404 return result;
2405 }
2406
2407 //
2408 // The next methods are derived from methods in MemNode.
2409 //
2410 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2411 Node *mem = mmem;
2412 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2413 // means an array I have not precisely typed yet. Do not do any
2414 // alias stuff with it any time soon.
2415 if (toop->base() != Type::AnyPtr &&
2416 !(toop->klass() != NULL &&
2417 toop->klass()->is_java_lang_Object() &&
2418 toop->offset() == Type::OffsetBot)) {
2419 mem = mmem->memory_at(alias_idx);
2420 // Update input if it is progress over what we have now
2421 }
2422 return mem;
2423 }
2424
2425 //
2426 // Move memory users to their memory slices.
2427 //
2428 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2429 Compile* C = _compile;
2430 PhaseGVN* igvn = _igvn;
2431 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2432 assert(tp != NULL, "ptr type");
2433 int alias_idx = C->get_alias_index(tp);
2434 int general_idx = C->get_general_index(alias_idx);
2435
2436 // Move users first
2437 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2438 Node* use = n->fast_out(i);
2439 if (use->is_MergeMem()) {
2440 MergeMemNode* mmem = use->as_MergeMem();
2441 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2442 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2443 continue; // Nothing to do
2444 }
2445 // Replace previous general reference to mem node.
2446 uint orig_uniq = C->unique();
2447 Node* m = find_inst_mem(n, general_idx, orig_phis);
2448 assert(orig_uniq == C->unique(), "no new nodes");
2449 mmem->set_memory_at(general_idx, m);
2450 --imax;
2451 --i;
2452 } else if (use->is_MemBar()) {
2453 assert(!use->is_Initialize(), "initializing stores should not be moved");
2454 if (use->req() > MemBarNode::Precedent &&
2455 use->in(MemBarNode::Precedent) == n) {
2456 // Don't move related membars.
2457 record_for_optimizer(use);
2458 continue;
2459 }
2460 tp = use->as_MemBar()->adr_type()->isa_ptr();
2461 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2462 alias_idx == general_idx) {
2463 continue; // Nothing to do
2464 }
2465 // Move to general memory slice.
2466 uint orig_uniq = C->unique();
2467 Node* m = find_inst_mem(n, general_idx, orig_phis);
2468 assert(orig_uniq == C->unique(), "no new nodes");
2469 igvn->hash_delete(use);
2470 imax -= use->replace_edge(n, m);
2471 igvn->hash_insert(use);
2472 record_for_optimizer(use);
2473 --i;
2474 #ifdef ASSERT
2475 } else if (use->is_Mem()) {
2476 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2477 // Don't move related cardmark.
2478 continue;
2479 }
2480 // Memory nodes should have new memory input.
2481 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2482 assert(tp != NULL, "ptr type");
2483 int idx = C->get_alias_index(tp);
2484 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2485 "Following memory nodes should have new memory input or be on the same memory slice");
2486 } else if (use->is_Phi()) {
2487 // Phi nodes should be split and moved already.
2488 tp = use->as_Phi()->adr_type()->isa_ptr();
2489 assert(tp != NULL, "ptr type");
2490 int idx = C->get_alias_index(tp);
2491 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2492 } else {
2493 use->dump();
2494 assert(false, "should not be here");
2495 #endif
2496 }
2497 }
2498 }
2499
2500 //
2501 // Search memory chain of "mem" to find a MemNode whose address
2502 // is the specified alias index.
2503 //
2504 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2505 if (orig_mem == NULL)
2506 return orig_mem;
2507 Compile* C = _compile;
2508 PhaseGVN* igvn = _igvn;
2509 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2510 bool is_instance = (toop != NULL) && toop->is_known_instance();
2511 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2512 Node *prev = NULL;
2513 Node *result = orig_mem;
2514 while (prev != result) {
2515 prev = result;
2516 if (result == start_mem)
2517 break; // hit one of our sentinels
2518 if (result->is_Mem()) {
2519 const Type *at = igvn->type(result->in(MemNode::Address));
2520 if (at == Type::TOP)
2521 break; // Dead
2522 assert (at->isa_ptr() != NULL, "pointer type required.");
2523 int idx = C->get_alias_index(at->is_ptr());
2524 if (idx == alias_idx)
2525 break; // Found
2526 if (!is_instance && (at->isa_oopptr() == NULL ||
2527 !at->is_oopptr()->is_known_instance())) {
2528 break; // Do not skip store to general memory slice.
2529 }
2530 result = result->in(MemNode::Memory);
2531 }
2532 if (!is_instance)
2533 continue; // don't search further for non-instance types
2534 // skip over a call which does not affect this memory slice
2535 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2536 Node *proj_in = result->in(0);
2537 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2538 break; // hit one of our sentinels
2539 } else if (proj_in->is_Call()) {
2540 CallNode *call = proj_in->as_Call();
2541 if (!call->may_modify(toop, igvn)) {
2542 result = call->in(TypeFunc::Memory);
2543 }
2544 } else if (proj_in->is_Initialize()) {
2545 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2546 // Stop if this is the initialization for the object instance which
2547 // which contains this memory slice, otherwise skip over it.
2548 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2549 result = proj_in->in(TypeFunc::Memory);
2550 }
2551 } else if (proj_in->is_MemBar()) {
2552 result = proj_in->in(TypeFunc::Memory);
2553 }
2554 } else if (result->is_MergeMem()) {
2555 MergeMemNode *mmem = result->as_MergeMem();
2556 result = step_through_mergemem(mmem, alias_idx, toop);
2557 if (result == mmem->base_memory()) {
2558 // Didn't find instance memory, search through general slice recursively.
2559 result = mmem->memory_at(C->get_general_index(alias_idx));
2560 result = find_inst_mem(result, alias_idx, orig_phis);
2561 if (C->failing()) {
2562 return NULL;
2563 }
2564 mmem->set_memory_at(alias_idx, result);
2565 }
2566 } else if (result->is_Phi() &&
2567 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2568 Node *un = result->as_Phi()->unique_input(igvn);
2569 if (un != NULL) {
2570 orig_phis.append_if_missing(result->as_Phi());
2571 result = un;
2572 } else {
2573 break;
2574 }
2575 } else if (result->is_ClearArray()) {
2576 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2577 // Can not bypass initialization of the instance
2578 // we are looking for.
2579 break;
2580 }
2581 // Otherwise skip it (the call updated 'result' value).
2582 } else if (result->Opcode() == Op_SCMemProj) {
2583 assert(result->in(0)->is_LoadStore(), "sanity");
2584 const Type *at = igvn->type(result->in(0)->in(MemNode::Address));
2585 if (at != Type::TOP) {
2586 assert (at->isa_ptr() != NULL, "pointer type required.");
2587 int idx = C->get_alias_index(at->is_ptr());
2588 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2589 break;
2590 }
2591 result = result->in(0)->in(MemNode::Memory);
2592 }
2593 }
2594 if (result->is_Phi()) {
2595 PhiNode *mphi = result->as_Phi();
2596 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2597 const TypePtr *t = mphi->adr_type();
2598 if (!is_instance) {
2599 // Push all non-instance Phis on the orig_phis worklist to update inputs
2600 // during Phase 4 if needed.
2601 orig_phis.append_if_missing(mphi);
2602 } else if (C->get_alias_index(t) != alias_idx) {
2603 // Create a new Phi with the specified alias index type.
2604 result = split_memory_phi(mphi, alias_idx, orig_phis);
2605 }
2606 }
2607 // the result is either MemNode, PhiNode, InitializeNode.
2608 return result;
2609 }
2610
2611 //
2612 // Convert the types of unescaped object to instance types where possible,
2613 // propagate the new type information through the graph, and update memory
2614 // edges and MergeMem inputs to reflect the new type.
2615 //
2616 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2617 // The processing is done in 4 phases:
2618 //
2619 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2620 // types for the CheckCastPP for allocations where possible.
2621 // Propagate the the new types through users as follows:
2622 // casts and Phi: push users on alloc_worklist
2623 // AddP: cast Base and Address inputs to the instance type
2624 // push any AddP users on alloc_worklist and push any memnode
2625 // users onto memnode_worklist.
2626 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2627 // search the Memory chain for a store with the appropriate type
2628 // address type. If a Phi is found, create a new version with
2629 // the appropriate memory slices from each of the Phi inputs.
2630 // For stores, process the users as follows:
2631 // MemNode: push on memnode_worklist
2632 // MergeMem: push on mergemem_worklist
2633 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2634 // moving the first node encountered of each instance type to the
2635 // the input corresponding to its alias index.
2636 // appropriate memory slice.
2637 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2638 //
2639 // In the following example, the CheckCastPP nodes are the cast of allocation
2640 // results and the allocation of node 29 is unescaped and eligible to be an
2641 // instance type.
2642 //
2643 // We start with:
2644 //
2645 // 7 Parm #memory
2646 // 10 ConI "12"
2647 // 19 CheckCastPP "Foo"
2648 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2649 // 29 CheckCastPP "Foo"
2650 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2651 //
2652 // 40 StoreP 25 7 20 ... alias_index=4
2653 // 50 StoreP 35 40 30 ... alias_index=4
2654 // 60 StoreP 45 50 20 ... alias_index=4
2655 // 70 LoadP _ 60 30 ... alias_index=4
2656 // 80 Phi 75 50 60 Memory alias_index=4
2657 // 90 LoadP _ 80 30 ... alias_index=4
2658 // 100 LoadP _ 80 20 ... alias_index=4
2659 //
2660 //
2661 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2662 // and creating a new alias index for node 30. This gives:
2663 //
2664 // 7 Parm #memory
2665 // 10 ConI "12"
2666 // 19 CheckCastPP "Foo"
2667 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2668 // 29 CheckCastPP "Foo" iid=24
2669 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2670 //
2671 // 40 StoreP 25 7 20 ... alias_index=4
2672 // 50 StoreP 35 40 30 ... alias_index=6
2673 // 60 StoreP 45 50 20 ... alias_index=4
2674 // 70 LoadP _ 60 30 ... alias_index=6
2675 // 80 Phi 75 50 60 Memory alias_index=4
2676 // 90 LoadP _ 80 30 ... alias_index=6
2677 // 100 LoadP _ 80 20 ... alias_index=4
2678 //
2679 // In phase 2, new memory inputs are computed for the loads and stores,
2680 // And a new version of the phi is created. In phase 4, the inputs to
2681 // node 80 are updated and then the memory nodes are updated with the
2682 // values computed in phase 2. This results in:
2683 //
2684 // 7 Parm #memory
2685 // 10 ConI "12"
2686 // 19 CheckCastPP "Foo"
2687 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2688 // 29 CheckCastPP "Foo" iid=24
2689 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2690 //
2691 // 40 StoreP 25 7 20 ... alias_index=4
2692 // 50 StoreP 35 7 30 ... alias_index=6
2693 // 60 StoreP 45 40 20 ... alias_index=4
2694 // 70 LoadP _ 50 30 ... alias_index=6
2695 // 80 Phi 75 40 60 Memory alias_index=4
2696 // 120 Phi 75 50 50 Memory alias_index=6
2697 // 90 LoadP _ 120 30 ... alias_index=6
2698 // 100 LoadP _ 80 20 ... alias_index=4
2699 //
2700 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2701 GrowableArray<Node *> memnode_worklist;
2702 GrowableArray<PhiNode *> orig_phis;
2703 PhaseIterGVN *igvn = _igvn;
2704 uint new_index_start = (uint) _compile->num_alias_types();
2705 Arena* arena = Thread::current()->resource_area();
2706 VectorSet visited(arena);
2707 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2708 uint unique_old = _compile->unique();
2709
2710 // Phase 1: Process possible allocations from alloc_worklist.
2711 // Create instance types for the CheckCastPP for allocations where possible.
2712 //
2713 // (Note: don't forget to change the order of the second AddP node on
2714 // the alloc_worklist if the order of the worklist processing is changed,
2715 // see the comment in find_second_addp().)
2716 //
2717 while (alloc_worklist.length() != 0) {
2718 Node *n = alloc_worklist.pop();
2719 uint ni = n->_idx;
2720 if (n->is_Call()) {
2721 CallNode *alloc = n->as_Call();
2722 // copy escape information to call node
2723 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2724 PointsToNode::EscapeState es = ptn->escape_state();
2725 // We have an allocation or call which returns a Java object,
2726 // see if it is unescaped.
2727 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2728 continue;
2729 // Find CheckCastPP for the allocate or for the return value of a call
2730 n = alloc->result_cast();
2731 if (n == NULL) { // No uses except Initialize node
2732 if (alloc->is_Allocate()) {
2733 // Set the scalar_replaceable flag for allocation
2734 // so it could be eliminated if it has no uses.
2735 alloc->as_Allocate()->_is_scalar_replaceable = true;
2736 }
2737 continue;
2738 }
2739 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2740 assert(!alloc->is_Allocate(), "allocation should have unique type");
2741 continue;
2742 }
2743
2744 // The inline code for Object.clone() casts the allocation result to
2745 // java.lang.Object and then to the actual type of the allocated
2746 // object. Detect this case and use the second cast.
2747 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2748 // the allocation result is cast to java.lang.Object and then
2749 // to the actual Array type.
2750 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2751 && (alloc->is_AllocateArray() ||
2752 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2753 Node *cast2 = NULL;
2754 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2755 Node *use = n->fast_out(i);
2756 if (use->is_CheckCastPP()) {
2757 cast2 = use;
2758 break;
2759 }
2760 }
2761 if (cast2 != NULL) {
2762 n = cast2;
2763 } else {
2764 // Non-scalar replaceable if the allocation type is unknown statically
2765 // (reflection allocation), the object can't be restored during
2766 // deoptimization without precise type.
2767 continue;
2768 }
2769 }
2770 if (alloc->is_Allocate()) {
2771 // Set the scalar_replaceable flag for allocation
2772 // so it could be eliminated.
2773 alloc->as_Allocate()->_is_scalar_replaceable = true;
2774 }
2775 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2776 // in order for an object to be scalar-replaceable, it must be:
2777 // - a direct allocation (not a call returning an object)
2778 // - non-escaping
2779 // - eligible to be a unique type
2780 // - not determined to be ineligible by escape analysis
2781 set_map(alloc, n);
2782 set_map(n, alloc);
2783 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2784 if (t == NULL)
2785 continue; // not a TypeOopPtr
2786 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2787 igvn->hash_delete(n);
2788 igvn->set_type(n, tinst);
2789 n->raise_bottom_type(tinst);
2790 igvn->hash_insert(n);
2791 record_for_optimizer(n);
2792 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2793
2794 // First, put on the worklist all Field edges from Connection Graph
2795 // which is more accurate then putting immediate users from Ideal Graph.
2796 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2797 PointsToNode* tgt = e.get();
2798 Node* use = tgt->ideal_node();
2799 assert(tgt->is_Field() && use->is_AddP(),
2800 "only AddP nodes are Field edges in CG");
2801 if (use->outcnt() > 0) { // Don't process dead nodes
2802 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2803 if (addp2 != NULL) {
2804 assert(alloc->is_AllocateArray(),"array allocation was expected");
2805 alloc_worklist.append_if_missing(addp2);
2806 }
2807 alloc_worklist.append_if_missing(use);
2808 }
2809 }
2810
2811 // An allocation may have an Initialize which has raw stores. Scan
2812 // the users of the raw allocation result and push AddP users
2813 // on alloc_worklist.
2814 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2815 assert (raw_result != NULL, "must have an allocation result");
2816 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2817 Node *use = raw_result->fast_out(i);
2818 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2819 Node* addp2 = find_second_addp(use, raw_result);
2820 if (addp2 != NULL) {
2821 assert(alloc->is_AllocateArray(),"array allocation was expected");
2822 alloc_worklist.append_if_missing(addp2);
2823 }
2824 alloc_worklist.append_if_missing(use);
2825 } else if (use->is_MemBar()) {
2826 memnode_worklist.append_if_missing(use);
2827 }
2828 }
2829 }
2830 } else if (n->is_AddP()) {
2831 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2832 if (jobj == NULL || jobj == phantom_obj) {
2833 #ifdef ASSERT
2834 ptnode_adr(get_addp_base(n)->_idx)->dump();
2835 ptnode_adr(n->_idx)->dump();
2836 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2837 #endif
2838 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2839 return;
2840 }
2841 Node *base = get_map(jobj->idx()); // CheckCastPP node
2842 if (!split_AddP(n, base)) continue; // wrong type from dead path
2843 } else if (n->is_Phi() ||
2844 n->is_CheckCastPP() ||
2845 n->is_EncodeP() ||
2846 n->is_DecodeN() ||
2847 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2848 if (visited.test_set(n->_idx)) {
2849 assert(n->is_Phi(), "loops only through Phi's");
2850 continue; // already processed
2851 }
2852 JavaObjectNode* jobj = unique_java_object(n);
2853 if (jobj == NULL || jobj == phantom_obj) {
2854 #ifdef ASSERT
2855 ptnode_adr(n->_idx)->dump();
2856 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2857 #endif
2858 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2859 return;
2860 } else {
2861 Node *val = get_map(jobj->idx()); // CheckCastPP node
2862 TypeNode *tn = n->as_Type();
2863 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2864 assert(tinst != NULL && tinst->is_known_instance() &&
2865 tinst->instance_id() == jobj->idx() , "instance type expected.");
2866
2867 const Type *tn_type = igvn->type(tn);
2868 const TypeOopPtr *tn_t;
2869 if (tn_type->isa_narrowoop()) {
2870 tn_t = tn_type->make_ptr()->isa_oopptr();
2871 } else {
2872 tn_t = tn_type->isa_oopptr();
2873 }
2874 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2875 if (tn_type->isa_narrowoop()) {
2876 tn_type = tinst->make_narrowoop();
2877 } else {
2878 tn_type = tinst;
2879 }
2880 igvn->hash_delete(tn);
2881 igvn->set_type(tn, tn_type);
2882 tn->set_type(tn_type);
2883 igvn->hash_insert(tn);
2884 record_for_optimizer(n);
2885 } else {
2886 assert(tn_type == TypePtr::NULL_PTR ||
2887 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2888 "unexpected type");
2889 continue; // Skip dead path with different type
2890 }
2891 }
2892 } else {
2893 debug_only(n->dump();)
2894 assert(false, "EA: unexpected node");
2895 continue;
2896 }
2897 // push allocation's users on appropriate worklist
2898 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2899 Node *use = n->fast_out(i);
2900 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2901 // Load/store to instance's field
2902 memnode_worklist.append_if_missing(use);
2903 } else if (use->is_MemBar()) {
2904 memnode_worklist.append_if_missing(use);
2905 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2906 Node* addp2 = find_second_addp(use, n);
2907 if (addp2 != NULL) {
2908 alloc_worklist.append_if_missing(addp2);
2909 }
2910 alloc_worklist.append_if_missing(use);
2911 } else if (use->is_Phi() ||
2912 use->is_CheckCastPP() ||
2913 use->is_EncodeP() ||
2914 use->is_DecodeN() ||
2915 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2916 alloc_worklist.append_if_missing(use);
2917 #ifdef ASSERT
2918 } else if (use->is_Mem()) {
2919 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2920 } else if (use->is_MergeMem()) {
2921 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2922 } else if (use->is_SafePoint()) {
2923 // Look for MergeMem nodes for calls which reference unique allocation
2924 // (through CheckCastPP nodes) even for debug info.
2925 Node* m = use->in(TypeFunc::Memory);
2926 if (m->is_MergeMem()) {
2927 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2928 }
2929 } else {
2930 uint op = use->Opcode();
2931 if (!(op == Op_CmpP || op == Op_Conv2B ||
2932 op == Op_CastP2X || op == Op_StoreCM ||
2933 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
2934 op == Op_StrEquals || op == Op_StrIndexOf)) {
2935 n->dump();
2936 use->dump();
2937 assert(false, "EA: missing allocation reference path");
2938 }
2939 #endif
2940 }
2941 }
2942
2943 }
2944 // New alias types were created in split_AddP().
2945 uint new_index_end = (uint) _compile->num_alias_types();
2946 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
2947
2948 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2949 // compute new values for Memory inputs (the Memory inputs are not
2950 // actually updated until phase 4.)
2951 if (memnode_worklist.length() == 0)
2952 return; // nothing to do
2953 while (memnode_worklist.length() != 0) {
2954 Node *n = memnode_worklist.pop();
2955 if (visited.test_set(n->_idx))
2956 continue;
2957 if (n->is_Phi() || n->is_ClearArray()) {
2958 // we don't need to do anything, but the users must be pushed
2959 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
2960 // we don't need to do anything, but the users must be pushed
2961 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
2962 if (n == NULL)
2963 continue;
2964 } else {
2965 assert(n->is_Mem(), "memory node required.");
2966 Node *addr = n->in(MemNode::Address);
2967 const Type *addr_t = igvn->type(addr);
2968 if (addr_t == Type::TOP)
2969 continue;
2970 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
2971 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
2972 assert ((uint)alias_idx < new_index_end, "wrong alias index");
2973 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
2974 if (_compile->failing()) {
2975 return;
2976 }
2977 if (mem != n->in(MemNode::Memory)) {
2978 // We delay the memory edge update since we need old one in
2979 // MergeMem code below when instances memory slices are separated.
2980 set_map(n, mem);
2981 }
2982 if (n->is_Load()) {
2983 continue; // don't push users
2984 } else if (n->is_LoadStore()) {
2985 // get the memory projection
2986 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2987 Node *use = n->fast_out(i);
2988 if (use->Opcode() == Op_SCMemProj) {
2989 n = use;
2990 break;
2991 }
2992 }
2993 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
2994 }
2995 }
2996 // push user on appropriate worklist
2997 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2998 Node *use = n->fast_out(i);
2999 if (use->is_Phi() || use->is_ClearArray()) {
3000 memnode_worklist.append_if_missing(use);
3001 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
3002 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3003 continue;
3004 memnode_worklist.append_if_missing(use);
3005 } else if (use->is_MemBar()) {
3006 memnode_worklist.append_if_missing(use);
3007 #ifdef ASSERT
3008 } else if(use->is_Mem()) {
3009 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3010 } else if (use->is_MergeMem()) {
3011 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3012 } else {
3013 uint op = use->Opcode();
3014 if (!(op == Op_StoreCM ||
3015 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3016 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3017 op == Op_AryEq || op == Op_StrComp ||
3018 op == Op_StrEquals || op == Op_StrIndexOf)) {
3019 n->dump();
3020 use->dump();
3021 assert(false, "EA: missing memory path");
3022 }
3023 #endif
3024 }
3025 }
3026 }
3027
3028 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3029 // Walk each memory slice moving the first node encountered of each
3030 // instance type to the the input corresponding to its alias index.
3031 uint length = _mergemem_worklist.length();
3032 for( uint next = 0; next < length; ++next ) {
3033 MergeMemNode* nmm = _mergemem_worklist.at(next);
3034 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3035 // Note: we don't want to use MergeMemStream here because we only want to
3036 // scan inputs which exist at the start, not ones we add during processing.
3037 // Note 2: MergeMem may already contains instance memory slices added
3038 // during find_inst_mem() call when memory nodes were processed above.
3039 igvn->hash_delete(nmm);
3040 uint nslices = nmm->req();
3041 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3042 Node* mem = nmm->in(i);
3043 Node* cur = NULL;
3044 if (mem == NULL || mem->is_top())
3045 continue;
3046 // First, update mergemem by moving memory nodes to corresponding slices
3047 // if their type became more precise since this mergemem was created.
3048 while (mem->is_Mem()) {
3049 const Type *at = igvn->type(mem->in(MemNode::Address));
3050 if (at != Type::TOP) {
3051 assert (at->isa_ptr() != NULL, "pointer type required.");
3052 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3053 if (idx == i) {
3054 if (cur == NULL)
3055 cur = mem;
3056 } else {
3057 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3058 nmm->set_memory_at(idx, mem);
3059 }
3060 }
3061 }
3062 mem = mem->in(MemNode::Memory);
3063 }
3064 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3065 // Find any instance of the current type if we haven't encountered
3066 // already a memory slice of the instance along the memory chain.
3067 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3068 if((uint)_compile->get_general_index(ni) == i) {
3069 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3070 if (nmm->is_empty_memory(m)) {
3071 Node* result = find_inst_mem(mem, ni, orig_phis);
3072 if (_compile->failing()) {
3073 return;
3074 }
3075 nmm->set_memory_at(ni, result);
3076 }
3077 }
3078 }
3079 }
3080 // Find the rest of instances values
3081 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3082 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3083 Node* result = step_through_mergemem(nmm, ni, tinst);
3084 if (result == nmm->base_memory()) {
3085 // Didn't find instance memory, search through general slice recursively.
3086 result = nmm->memory_at(_compile->get_general_index(ni));
3087 result = find_inst_mem(result, ni, orig_phis);
3088 if (_compile->failing()) {
3089 return;
3090 }
3091 nmm->set_memory_at(ni, result);
3092 }
3093 }
3094 igvn->hash_insert(nmm);
3095 record_for_optimizer(nmm);
3096 }
3097
3098 // Phase 4: Update the inputs of non-instance memory Phis and
3099 // the Memory input of memnodes
3100 // First update the inputs of any non-instance Phi's from
3101 // which we split out an instance Phi. Note we don't have
3102 // to recursively process Phi's encounted on the input memory
3103 // chains as is done in split_memory_phi() since they will
3104 // also be processed here.
3105 for (int j = 0; j < orig_phis.length(); j++) {
3106 PhiNode *phi = orig_phis.at(j);
3107 int alias_idx = _compile->get_alias_index(phi->adr_type());
3108 igvn->hash_delete(phi);
3109 for (uint i = 1; i < phi->req(); i++) {
3110 Node *mem = phi->in(i);
3111 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3112 if (_compile->failing()) {
3113 return;
3114 }
3115 if (mem != new_mem) {
3116 phi->set_req(i, new_mem);
3117 }
3118 }
3119 igvn->hash_insert(phi);
3120 record_for_optimizer(phi);
3121 }
3122
3123 // Update the memory inputs of MemNodes with the value we computed
3124 // in Phase 2 and move stores memory users to corresponding memory slices.
3125 // Disable memory split verification code until the fix for 6984348.
3126 // Currently it produces false negative results since it does not cover all cases.
3127 #if 0 // ifdef ASSERT
3128 visited.Reset();
3129 Node_Stack old_mems(arena, _compile->unique() >> 2);
3130 #endif
3131 for (uint i = 0; i < ideal_nodes.size(); i++) {
3132 Node* n = ideal_nodes.at(i);
3133 Node* nmem = get_map(n->_idx);
3134 assert(nmem != NULL, "sanity");
3135 if (n->is_Mem()) {
3136 #if 0 // ifdef ASSERT
3137 Node* old_mem = n->in(MemNode::Memory);
3138 if (!visited.test_set(old_mem->_idx)) {
3139 old_mems.push(old_mem, old_mem->outcnt());
3140 }
3141 #endif
3142 assert(n->in(MemNode::Memory) != nmem, "sanity");
3143 if (!n->is_Load()) {
3144 // Move memory users of a store first.
3145 move_inst_mem(n, orig_phis);
3146 }
3147 // Now update memory input
3148 igvn->hash_delete(n);
3149 n->set_req(MemNode::Memory, nmem);
3150 igvn->hash_insert(n);
3151 record_for_optimizer(n);
3152 } else {
3153 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3154 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3155 }
3156 }
3157 #if 0 // ifdef ASSERT
3158 // Verify that memory was split correctly
3159 while (old_mems.is_nonempty()) {
3160 Node* old_mem = old_mems.node();
3161 uint old_cnt = old_mems.index();
3162 old_mems.pop();
3163 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3164 }
3165 #endif
3166 }
3167
3168 #ifndef PRODUCT
3169 static const char *node_type_names[] = {
3170 "UnknownType",
3171 "JavaObject",
3172 "LocalVar",
3173 "Field",
3174 "Arraycopy"
3175 };
3176
3177 static const char *esc_names[] = {
3178 "UnknownEscape",
3179 "NoEscape",
3180 "ArgEscape",
3181 "GlobalEscape"
3182 };
3183
3184 void PointsToNode::dump(bool print_state) const {
3185 NodeType nt = node_type();
3186 tty->print("%s ", node_type_names[(int) nt]);
3187 if (print_state) {
3188 EscapeState es = escape_state();
3189 EscapeState fields_es = fields_escape_state();
3190 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3191 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3192 tty->print("NSR ");
3193 }
3194 if (is_Field()) {
3195 FieldNode* f = (FieldNode*)this;
3196 if (f->is_oop())
3197 tty->print("oop ");
3198 if (f->offset() > 0)
3199 tty->print("+%d ", f->offset());
3200 tty->print("(");
3201 for (BaseIterator i(f); i.has_next(); i.next()) {
3202 PointsToNode* b = i.get();
3203 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3204 }
3205 tty->print(" )");
3206 }
3207 tty->print("[");
3208 for (EdgeIterator i(this); i.has_next(); i.next()) {
3209 PointsToNode* e = i.get();
3210 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3211 }
3212 tty->print(" [");
3213 for (UseIterator i(this); i.has_next(); i.next()) {
3214 PointsToNode* u = i.get();
3215 bool is_base = false;
3216 if (PointsToNode::is_base_use(u)) {
3217 is_base = true;
3218 u = PointsToNode::get_use_node(u)->as_Field();
3219 }
3220 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3221 }
3222 tty->print(" ]] ");
3223 if (_node == NULL)
3224 tty->print_cr("<null>");
3225 else
3226 _node->dump();
3227 }
3228
3229 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3230 bool first = true;
3231 int ptnodes_length = ptnodes_worklist.length();
3232 for (int i = 0; i < ptnodes_length; i++) {
3233 PointsToNode *ptn = ptnodes_worklist.at(i);
3234 if (ptn == NULL || !ptn->is_JavaObject())
3235 continue;
3236 PointsToNode::EscapeState es = ptn->escape_state();
3237 if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3238 if (first) {
3239 tty->cr();
3240 tty->print("======== Connection graph for ");
3241 _compile->method()->print_short_name();
3242 tty->cr();
3243 first = false;
3244 }
3245 ptn->dump();
3246 // Print all locals and fields which reference this allocation
3247 for (UseIterator j(ptn); j.has_next(); j.next()) {
3248 PointsToNode* use = j.get();
3249 if (use->is_LocalVar()) {
3250 use->dump(Verbose);
3251 } else if (Verbose) {
3252 use->dump();
3253 }
3254 }
3255 tty->cr();
3256 }
3257 }
3258 }
3259 #endif