Thu, 09 May 2013 17:28:04 -0700
8014189: JVM crash with SEGV in ConnectionGraph::record_for_escape_analysis()
Summary: Add NULL checks and asserts for Type::make_ptr() returned value.
Reviewed-by: twisti
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.
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23 */
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"
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 }
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 if (n->is_CallStaticJava() &&
76 n->as_CallStaticJava()->is_boxing_method()) {
77 return true;
78 }
79 }
80 return false;
81 }
83 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
84 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
85 ResourceMark rm;
87 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
88 // to create space for them in ConnectionGraph::_nodes[].
89 Node* oop_null = igvn->zerocon(T_OBJECT);
90 Node* noop_null = igvn->zerocon(T_NARROWOOP);
91 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
92 // Perform escape analysis
93 if (congraph->compute_escape()) {
94 // There are non escaping objects.
95 C->set_congraph(congraph);
96 }
97 // Cleanup.
98 if (oop_null->outcnt() == 0)
99 igvn->hash_delete(oop_null);
100 if (noop_null->outcnt() == 0)
101 igvn->hash_delete(noop_null);
102 }
104 bool ConnectionGraph::compute_escape() {
105 Compile* C = _compile;
106 PhaseGVN* igvn = _igvn;
108 // Worklists used by EA.
109 Unique_Node_List delayed_worklist;
110 GrowableArray<Node*> alloc_worklist;
111 GrowableArray<Node*> ptr_cmp_worklist;
112 GrowableArray<Node*> storestore_worklist;
113 GrowableArray<PointsToNode*> ptnodes_worklist;
114 GrowableArray<JavaObjectNode*> java_objects_worklist;
115 GrowableArray<JavaObjectNode*> non_escaped_worklist;
116 GrowableArray<FieldNode*> oop_fields_worklist;
117 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
119 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
121 // 1. Populate Connection Graph (CG) with PointsTo nodes.
122 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
123 // Initialize worklist
124 if (C->root() != NULL) {
125 ideal_nodes.push(C->root());
126 }
127 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
128 Node* n = ideal_nodes.at(next);
129 // Create PointsTo nodes and add them to Connection Graph. Called
130 // only once per ideal node since ideal_nodes is Unique_Node list.
131 add_node_to_connection_graph(n, &delayed_worklist);
132 PointsToNode* ptn = ptnode_adr(n->_idx);
133 if (ptn != NULL) {
134 ptnodes_worklist.append(ptn);
135 if (ptn->is_JavaObject()) {
136 java_objects_worklist.append(ptn->as_JavaObject());
137 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
138 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
139 // Only allocations and java static calls results are interesting.
140 non_escaped_worklist.append(ptn->as_JavaObject());
141 }
142 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
143 oop_fields_worklist.append(ptn->as_Field());
144 }
145 }
146 if (n->is_MergeMem()) {
147 // Collect all MergeMem nodes to add memory slices for
148 // scalar replaceable objects in split_unique_types().
149 _mergemem_worklist.append(n->as_MergeMem());
150 } else if (OptimizePtrCompare && n->is_Cmp() &&
151 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
152 // Collect compare pointers nodes.
153 ptr_cmp_worklist.append(n);
154 } else if (n->is_MemBarStoreStore()) {
155 // Collect all MemBarStoreStore nodes so that depending on the
156 // escape status of the associated Allocate node some of them
157 // may be eliminated.
158 storestore_worklist.append(n);
159 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
160 (n->req() > MemBarNode::Precedent)) {
161 record_for_optimizer(n);
162 #ifdef ASSERT
163 } else if (n->is_AddP()) {
164 // Collect address nodes for graph verification.
165 addp_worklist.append(n);
166 #endif
167 }
168 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
169 Node* m = n->fast_out(i); // Get user
170 ideal_nodes.push(m);
171 }
172 }
173 if (non_escaped_worklist.length() == 0) {
174 _collecting = false;
175 return false; // Nothing to do.
176 }
177 // Add final simple edges to graph.
178 while(delayed_worklist.size() > 0) {
179 Node* n = delayed_worklist.pop();
180 add_final_edges(n);
181 }
182 int ptnodes_length = ptnodes_worklist.length();
184 #ifdef ASSERT
185 if (VerifyConnectionGraph) {
186 // Verify that no new simple edges could be created and all
187 // local vars has edges.
188 _verify = true;
189 for (int next = 0; next < ptnodes_length; ++next) {
190 PointsToNode* ptn = ptnodes_worklist.at(next);
191 add_final_edges(ptn->ideal_node());
192 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
193 ptn->dump();
194 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
195 }
196 }
197 _verify = false;
198 }
199 #endif
201 // 2. Finish Graph construction by propagating references to all
202 // java objects through graph.
203 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
204 java_objects_worklist, oop_fields_worklist)) {
205 // All objects escaped or hit time or iterations limits.
206 _collecting = false;
207 return false;
208 }
210 // 3. Adjust scalar_replaceable state of nonescaping objects and push
211 // scalar replaceable allocations on alloc_worklist for processing
212 // in split_unique_types().
213 int non_escaped_length = non_escaped_worklist.length();
214 for (int next = 0; next < non_escaped_length; next++) {
215 JavaObjectNode* ptn = non_escaped_worklist.at(next);
216 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
217 Node* n = ptn->ideal_node();
218 if (n->is_Allocate()) {
219 n->as_Allocate()->_is_non_escaping = noescape;
220 }
221 if (n->is_CallStaticJava()) {
222 n->as_CallStaticJava()->_is_non_escaping = noescape;
223 }
224 if (noescape && ptn->scalar_replaceable()) {
225 adjust_scalar_replaceable_state(ptn);
226 if (ptn->scalar_replaceable()) {
227 alloc_worklist.append(ptn->ideal_node());
228 }
229 }
230 }
232 #ifdef ASSERT
233 if (VerifyConnectionGraph) {
234 // Verify that graph is complete - no new edges could be added or needed.
235 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
236 java_objects_worklist, addp_worklist);
237 }
238 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
239 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
240 null_obj->edge_count() == 0 &&
241 !null_obj->arraycopy_src() &&
242 !null_obj->arraycopy_dst(), "sanity");
243 #endif
245 _collecting = false;
247 } // TracePhase t3("connectionGraph")
249 // 4. Optimize ideal graph based on EA information.
250 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
251 if (has_non_escaping_obj) {
252 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
253 }
255 #ifndef PRODUCT
256 if (PrintEscapeAnalysis) {
257 dump(ptnodes_worklist); // Dump ConnectionGraph
258 }
259 #endif
261 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
262 #ifdef ASSERT
263 if (VerifyConnectionGraph) {
264 int alloc_length = alloc_worklist.length();
265 for (int next = 0; next < alloc_length; ++next) {
266 Node* n = alloc_worklist.at(next);
267 PointsToNode* ptn = ptnode_adr(n->_idx);
268 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
269 }
270 }
271 #endif
273 // 5. Separate memory graph for scalar replaceable allcations.
274 if (has_scalar_replaceable_candidates &&
275 C->AliasLevel() >= 3 && EliminateAllocations) {
276 // Now use the escape information to create unique types for
277 // scalar replaceable objects.
278 split_unique_types(alloc_worklist);
279 if (C->failing()) return false;
280 C->print_method("After Escape Analysis", 2);
282 #ifdef ASSERT
283 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
284 tty->print("=== No allocations eliminated for ");
285 C->method()->print_short_name();
286 if(!EliminateAllocations) {
287 tty->print(" since EliminateAllocations is off ===");
288 } else if(!has_scalar_replaceable_candidates) {
289 tty->print(" since there are no scalar replaceable candidates ===");
290 } else if(C->AliasLevel() < 3) {
291 tty->print(" since AliasLevel < 3 ===");
292 }
293 tty->cr();
294 #endif
295 }
296 return has_non_escaping_obj;
297 }
299 // Utility function for nodes that load an object
300 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
301 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
302 // ThreadLocal has RawPtr type.
303 const Type* t = _igvn->type(n);
304 if (t->make_ptr() != NULL) {
305 Node* adr = n->in(MemNode::Address);
306 #ifdef ASSERT
307 if (!adr->is_AddP()) {
308 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
309 } else {
310 assert((ptnode_adr(adr->_idx) == NULL ||
311 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
312 }
313 #endif
314 add_local_var_and_edge(n, PointsToNode::NoEscape,
315 adr, delayed_worklist);
316 }
317 }
319 // Populate Connection Graph with PointsTo nodes and create simple
320 // connection graph edges.
321 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
322 assert(!_verify, "this method sould not be called for verification");
323 PhaseGVN* igvn = _igvn;
324 uint n_idx = n->_idx;
325 PointsToNode* n_ptn = ptnode_adr(n_idx);
326 if (n_ptn != NULL)
327 return; // No need to redefine PointsTo node during first iteration.
329 if (n->is_Call()) {
330 // Arguments to allocation and locking don't escape.
331 if (n->is_AbstractLock()) {
332 // Put Lock and Unlock nodes on IGVN worklist to process them during
333 // first IGVN optimization when escape information is still available.
334 record_for_optimizer(n);
335 } else if (n->is_Allocate()) {
336 add_call_node(n->as_Call());
337 record_for_optimizer(n);
338 } else {
339 if (n->is_CallStaticJava()) {
340 const char* name = n->as_CallStaticJava()->_name;
341 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
342 return; // Skip uncommon traps
343 }
344 // Don't mark as processed since call's arguments have to be processed.
345 delayed_worklist->push(n);
346 // Check if a call returns an object.
347 if ((n->as_Call()->returns_pointer() &&
348 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
349 (n->is_CallStaticJava() &&
350 n->as_CallStaticJava()->is_boxing_method())) {
351 add_call_node(n->as_Call());
352 }
353 }
354 return;
355 }
356 // Put this check here to process call arguments since some call nodes
357 // point to phantom_obj.
358 if (n_ptn == phantom_obj || n_ptn == null_obj)
359 return; // Skip predefined nodes.
361 int opcode = n->Opcode();
362 switch (opcode) {
363 case Op_AddP: {
364 Node* base = get_addp_base(n);
365 PointsToNode* ptn_base = ptnode_adr(base->_idx);
366 // Field nodes are created for all field types. They are used in
367 // adjust_scalar_replaceable_state() and split_unique_types().
368 // Note, non-oop fields will have only base edges in Connection
369 // Graph because such fields are not used for oop loads and stores.
370 int offset = address_offset(n, igvn);
371 add_field(n, PointsToNode::NoEscape, offset);
372 if (ptn_base == NULL) {
373 delayed_worklist->push(n); // Process it later.
374 } else {
375 n_ptn = ptnode_adr(n_idx);
376 add_base(n_ptn->as_Field(), ptn_base);
377 }
378 break;
379 }
380 case Op_CastX2P: {
381 map_ideal_node(n, phantom_obj);
382 break;
383 }
384 case Op_CastPP:
385 case Op_CheckCastPP:
386 case Op_EncodeP:
387 case Op_DecodeN:
388 case Op_EncodePKlass:
389 case Op_DecodeNKlass: {
390 add_local_var_and_edge(n, PointsToNode::NoEscape,
391 n->in(1), delayed_worklist);
392 break;
393 }
394 case Op_CMoveP: {
395 add_local_var(n, PointsToNode::NoEscape);
396 // Do not add edges during first iteration because some could be
397 // not defined yet.
398 delayed_worklist->push(n);
399 break;
400 }
401 case Op_ConP:
402 case Op_ConN:
403 case Op_ConNKlass: {
404 // assume all oop constants globally escape except for null
405 PointsToNode::EscapeState es;
406 const Type* t = igvn->type(n);
407 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
408 es = PointsToNode::NoEscape;
409 } else {
410 es = PointsToNode::GlobalEscape;
411 }
412 add_java_object(n, es);
413 break;
414 }
415 case Op_CreateEx: {
416 // assume that all exception objects globally escape
417 add_java_object(n, PointsToNode::GlobalEscape);
418 break;
419 }
420 case Op_LoadKlass:
421 case Op_LoadNKlass: {
422 // Unknown class is loaded
423 map_ideal_node(n, phantom_obj);
424 break;
425 }
426 case Op_LoadP:
427 case Op_LoadN:
428 case Op_LoadPLocked: {
429 add_objload_to_connection_graph(n, delayed_worklist);
430 break;
431 }
432 case Op_Parm: {
433 map_ideal_node(n, phantom_obj);
434 break;
435 }
436 case Op_PartialSubtypeCheck: {
437 // Produces Null or notNull and is used in only in CmpP so
438 // phantom_obj could be used.
439 map_ideal_node(n, phantom_obj); // Result is unknown
440 break;
441 }
442 case Op_Phi: {
443 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
444 // ThreadLocal has RawPtr type.
445 const Type* t = n->as_Phi()->type();
446 if (t->make_ptr() != NULL) {
447 add_local_var(n, PointsToNode::NoEscape);
448 // Do not add edges during first iteration because some could be
449 // not defined yet.
450 delayed_worklist->push(n);
451 }
452 break;
453 }
454 case Op_Proj: {
455 // we are only interested in the oop result projection from a call
456 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
457 n->in(0)->as_Call()->returns_pointer()) {
458 add_local_var_and_edge(n, PointsToNode::NoEscape,
459 n->in(0), delayed_worklist);
460 }
461 break;
462 }
463 case Op_Rethrow: // Exception object escapes
464 case Op_Return: {
465 if (n->req() > TypeFunc::Parms &&
466 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
467 // Treat Return value as LocalVar with GlobalEscape escape state.
468 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
469 n->in(TypeFunc::Parms), delayed_worklist);
470 }
471 break;
472 }
473 case Op_GetAndSetP:
474 case Op_GetAndSetN: {
475 add_objload_to_connection_graph(n, delayed_worklist);
476 // fallthrough
477 }
478 case Op_StoreP:
479 case Op_StoreN:
480 case Op_StoreNKlass:
481 case Op_StorePConditional:
482 case Op_CompareAndSwapP:
483 case Op_CompareAndSwapN: {
484 Node* adr = n->in(MemNode::Address);
485 const Type *adr_type = igvn->type(adr);
486 adr_type = adr_type->make_ptr();
487 if (adr_type == NULL) {
488 break; // skip dead nodes
489 }
490 if (adr_type->isa_oopptr() ||
491 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
492 (adr_type == TypeRawPtr::NOTNULL &&
493 adr->in(AddPNode::Address)->is_Proj() &&
494 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
495 delayed_worklist->push(n); // Process it later.
496 #ifdef ASSERT
497 assert(adr->is_AddP(), "expecting an AddP");
498 if (adr_type == TypeRawPtr::NOTNULL) {
499 // Verify a raw address for a store captured by Initialize node.
500 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
501 assert(offs != Type::OffsetBot, "offset must be a constant");
502 }
503 #endif
504 } else {
505 // Ignore copy the displaced header to the BoxNode (OSR compilation).
506 if (adr->is_BoxLock())
507 break;
508 // Stored value escapes in unsafe access.
509 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
510 // Pointer stores in G1 barriers looks like unsafe access.
511 // Ignore such stores to be able scalar replace non-escaping
512 // allocations.
513 if (UseG1GC && adr->is_AddP()) {
514 Node* base = get_addp_base(adr);
515 if (base->Opcode() == Op_LoadP &&
516 base->in(MemNode::Address)->is_AddP()) {
517 adr = base->in(MemNode::Address);
518 Node* tls = get_addp_base(adr);
519 if (tls->Opcode() == Op_ThreadLocal) {
520 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
521 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
522 PtrQueue::byte_offset_of_buf())) {
523 break; // G1 pre barier previous oop value store.
524 }
525 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
526 PtrQueue::byte_offset_of_buf())) {
527 break; // G1 post barier card address store.
528 }
529 }
530 }
531 }
532 delayed_worklist->push(n); // Process unsafe access later.
533 break;
534 }
535 #ifdef ASSERT
536 n->dump(1);
537 assert(false, "not unsafe or G1 barrier raw StoreP");
538 #endif
539 }
540 break;
541 }
542 case Op_AryEq:
543 case Op_StrComp:
544 case Op_StrEquals:
545 case Op_StrIndexOf:
546 case Op_EncodeISOArray: {
547 add_local_var(n, PointsToNode::ArgEscape);
548 delayed_worklist->push(n); // Process it later.
549 break;
550 }
551 case Op_ThreadLocal: {
552 add_java_object(n, PointsToNode::ArgEscape);
553 break;
554 }
555 default:
556 ; // Do nothing for nodes not related to EA.
557 }
558 return;
559 }
561 #ifdef ASSERT
562 #define ELSE_FAIL(name) \
563 /* Should not be called for not pointer type. */ \
564 n->dump(1); \
565 assert(false, name); \
566 break;
567 #else
568 #define ELSE_FAIL(name) \
569 break;
570 #endif
572 // Add final simple edges to graph.
573 void ConnectionGraph::add_final_edges(Node *n) {
574 PointsToNode* n_ptn = ptnode_adr(n->_idx);
575 #ifdef ASSERT
576 if (_verify && n_ptn->is_JavaObject())
577 return; // This method does not change graph for JavaObject.
578 #endif
580 if (n->is_Call()) {
581 process_call_arguments(n->as_Call());
582 return;
583 }
584 assert(n->is_Store() || n->is_LoadStore() ||
585 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
586 "node should be registered already");
587 int opcode = n->Opcode();
588 switch (opcode) {
589 case Op_AddP: {
590 Node* base = get_addp_base(n);
591 PointsToNode* ptn_base = ptnode_adr(base->_idx);
592 assert(ptn_base != NULL, "field's base should be registered");
593 add_base(n_ptn->as_Field(), ptn_base);
594 break;
595 }
596 case Op_CastPP:
597 case Op_CheckCastPP:
598 case Op_EncodeP:
599 case Op_DecodeN:
600 case Op_EncodePKlass:
601 case Op_DecodeNKlass: {
602 add_local_var_and_edge(n, PointsToNode::NoEscape,
603 n->in(1), NULL);
604 break;
605 }
606 case Op_CMoveP: {
607 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
608 Node* in = n->in(i);
609 if (in == NULL)
610 continue; // ignore NULL
611 Node* uncast_in = in->uncast();
612 if (uncast_in->is_top() || uncast_in == n)
613 continue; // ignore top or inputs which go back this node
614 PointsToNode* ptn = ptnode_adr(in->_idx);
615 assert(ptn != NULL, "node should be registered");
616 add_edge(n_ptn, ptn);
617 }
618 break;
619 }
620 case Op_LoadP:
621 case Op_LoadN:
622 case Op_LoadPLocked: {
623 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
624 // ThreadLocal has RawPtr type.
625 const Type* t = _igvn->type(n);
626 if (t->make_ptr() != NULL) {
627 Node* adr = n->in(MemNode::Address);
628 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
629 break;
630 }
631 ELSE_FAIL("Op_LoadP");
632 }
633 case Op_Phi: {
634 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
635 // ThreadLocal has RawPtr type.
636 const Type* t = n->as_Phi()->type();
637 if (t->make_ptr() != NULL) {
638 for (uint i = 1; i < n->req(); i++) {
639 Node* in = n->in(i);
640 if (in == NULL)
641 continue; // ignore NULL
642 Node* uncast_in = in->uncast();
643 if (uncast_in->is_top() || uncast_in == n)
644 continue; // ignore top or inputs which go back this node
645 PointsToNode* ptn = ptnode_adr(in->_idx);
646 assert(ptn != NULL, "node should be registered");
647 add_edge(n_ptn, ptn);
648 }
649 break;
650 }
651 ELSE_FAIL("Op_Phi");
652 }
653 case Op_Proj: {
654 // we are only interested in the oop result projection from a call
655 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
656 n->in(0)->as_Call()->returns_pointer()) {
657 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
658 break;
659 }
660 ELSE_FAIL("Op_Proj");
661 }
662 case Op_Rethrow: // Exception object escapes
663 case Op_Return: {
664 if (n->req() > TypeFunc::Parms &&
665 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
666 // Treat Return value as LocalVar with GlobalEscape escape state.
667 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
668 n->in(TypeFunc::Parms), NULL);
669 break;
670 }
671 ELSE_FAIL("Op_Return");
672 }
673 case Op_StoreP:
674 case Op_StoreN:
675 case Op_StoreNKlass:
676 case Op_StorePConditional:
677 case Op_CompareAndSwapP:
678 case Op_CompareAndSwapN:
679 case Op_GetAndSetP:
680 case Op_GetAndSetN: {
681 Node* adr = n->in(MemNode::Address);
682 const Type *adr_type = _igvn->type(adr);
683 adr_type = adr_type->make_ptr();
684 #ifdef ASSERT
685 if (adr_type == NULL) {
686 n->dump(1);
687 assert(adr_type != NULL, "dead node should not be on list");
688 break;
689 }
690 #endif
691 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
692 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
693 }
694 if (adr_type->isa_oopptr() ||
695 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
696 (adr_type == TypeRawPtr::NOTNULL &&
697 adr->in(AddPNode::Address)->is_Proj() &&
698 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
699 // Point Address to Value
700 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
701 assert(adr_ptn != NULL &&
702 adr_ptn->as_Field()->is_oop(), "node should be registered");
703 Node *val = n->in(MemNode::ValueIn);
704 PointsToNode* ptn = ptnode_adr(val->_idx);
705 assert(ptn != NULL, "node should be registered");
706 add_edge(adr_ptn, ptn);
707 break;
708 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
709 // Stored value escapes in unsafe access.
710 Node *val = n->in(MemNode::ValueIn);
711 PointsToNode* ptn = ptnode_adr(val->_idx);
712 assert(ptn != NULL, "node should be registered");
713 ptn->set_escape_state(PointsToNode::GlobalEscape);
714 // Add edge to object for unsafe access with offset.
715 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
716 assert(adr_ptn != NULL, "node should be registered");
717 if (adr_ptn->is_Field()) {
718 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
719 add_edge(adr_ptn, ptn);
720 }
721 break;
722 }
723 ELSE_FAIL("Op_StoreP");
724 }
725 case Op_AryEq:
726 case Op_StrComp:
727 case Op_StrEquals:
728 case Op_StrIndexOf:
729 case Op_EncodeISOArray: {
730 // char[] arrays passed to string intrinsic do not escape but
731 // they are not scalar replaceable. Adjust escape state for them.
732 // Start from in(2) edge since in(1) is memory edge.
733 for (uint i = 2; i < n->req(); i++) {
734 Node* adr = n->in(i);
735 const Type* at = _igvn->type(adr);
736 if (!adr->is_top() && at->isa_ptr()) {
737 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
738 at->isa_ptr() != NULL, "expecting a pointer");
739 if (adr->is_AddP()) {
740 adr = get_addp_base(adr);
741 }
742 PointsToNode* ptn = ptnode_adr(adr->_idx);
743 assert(ptn != NULL, "node should be registered");
744 add_edge(n_ptn, ptn);
745 }
746 }
747 break;
748 }
749 default: {
750 // This method should be called only for EA specific nodes which may
751 // miss some edges when they were created.
752 #ifdef ASSERT
753 n->dump(1);
754 #endif
755 guarantee(false, "unknown node");
756 }
757 }
758 return;
759 }
761 void ConnectionGraph::add_call_node(CallNode* call) {
762 assert(call->returns_pointer(), "only for call which returns pointer");
763 uint call_idx = call->_idx;
764 if (call->is_Allocate()) {
765 Node* k = call->in(AllocateNode::KlassNode);
766 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
767 assert(kt != NULL, "TypeKlassPtr required.");
768 ciKlass* cik = kt->klass();
769 PointsToNode::EscapeState es = PointsToNode::NoEscape;
770 bool scalar_replaceable = true;
771 if (call->is_AllocateArray()) {
772 if (!cik->is_array_klass()) { // StressReflectiveCode
773 es = PointsToNode::GlobalEscape;
774 } else {
775 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
776 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
777 // Not scalar replaceable if the length is not constant or too big.
778 scalar_replaceable = false;
779 }
780 }
781 } else { // Allocate instance
782 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
783 !cik->is_instance_klass() || // StressReflectiveCode
784 cik->as_instance_klass()->has_finalizer()) {
785 es = PointsToNode::GlobalEscape;
786 }
787 }
788 add_java_object(call, es);
789 PointsToNode* ptn = ptnode_adr(call_idx);
790 if (!scalar_replaceable && ptn->scalar_replaceable()) {
791 ptn->set_scalar_replaceable(false);
792 }
793 } else if (call->is_CallStaticJava()) {
794 // Call nodes could be different types:
795 //
796 // 1. CallDynamicJavaNode (what happened during call is unknown):
797 //
798 // - mapped to GlobalEscape JavaObject node if oop is returned;
799 //
800 // - all oop arguments are escaping globally;
801 //
802 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
803 //
804 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
805 //
806 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
807 // - mapped to NoEscape JavaObject node if non-escaping object allocated
808 // during call is returned;
809 // - mapped to ArgEscape LocalVar node pointed to object arguments
810 // which are returned and does not escape during call;
811 //
812 // - oop arguments escaping status is defined by bytecode analysis;
813 //
814 // For a static call, we know exactly what method is being called.
815 // Use bytecode estimator to record whether the call's return value escapes.
816 ciMethod* meth = call->as_CallJava()->method();
817 if (meth == NULL) {
818 const char* name = call->as_CallStaticJava()->_name;
819 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
820 // Returns a newly allocated unescaped object.
821 add_java_object(call, PointsToNode::NoEscape);
822 ptnode_adr(call_idx)->set_scalar_replaceable(false);
823 } else if (meth->is_boxing_method()) {
824 // Returns boxing object
825 add_java_object(call, PointsToNode::NoEscape);
826 } else {
827 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
828 call_analyzer->copy_dependencies(_compile->dependencies());
829 if (call_analyzer->is_return_allocated()) {
830 // Returns a newly allocated unescaped object, simply
831 // update dependency information.
832 // Mark it as NoEscape so that objects referenced by
833 // it's fields will be marked as NoEscape at least.
834 add_java_object(call, PointsToNode::NoEscape);
835 ptnode_adr(call_idx)->set_scalar_replaceable(false);
836 } else {
837 // Determine whether any arguments are returned.
838 const TypeTuple* d = call->tf()->domain();
839 bool ret_arg = false;
840 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
841 if (d->field_at(i)->isa_ptr() != NULL &&
842 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
843 ret_arg = true;
844 break;
845 }
846 }
847 if (ret_arg) {
848 add_local_var(call, PointsToNode::ArgEscape);
849 } else {
850 // Returns unknown object.
851 map_ideal_node(call, phantom_obj);
852 }
853 }
854 }
855 } else {
856 // An other type of call, assume the worst case:
857 // returned value is unknown and globally escapes.
858 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
859 map_ideal_node(call, phantom_obj);
860 }
861 }
863 void ConnectionGraph::process_call_arguments(CallNode *call) {
864 bool is_arraycopy = false;
865 switch (call->Opcode()) {
866 #ifdef ASSERT
867 case Op_Allocate:
868 case Op_AllocateArray:
869 case Op_Lock:
870 case Op_Unlock:
871 assert(false, "should be done already");
872 break;
873 #endif
874 case Op_CallLeafNoFP:
875 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
876 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
877 // fall through
878 case Op_CallLeaf: {
879 // Stub calls, objects do not escape but they are not scale replaceable.
880 // Adjust escape state for outgoing arguments.
881 const TypeTuple * d = call->tf()->domain();
882 bool src_has_oops = false;
883 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
884 const Type* at = d->field_at(i);
885 Node *arg = call->in(i);
886 const Type *aat = _igvn->type(arg);
887 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
888 continue;
889 if (arg->is_AddP()) {
890 //
891 // The inline_native_clone() case when the arraycopy stub is called
892 // after the allocation before Initialize and CheckCastPP nodes.
893 // Or normal arraycopy for object arrays case.
894 //
895 // Set AddP's base (Allocate) as not scalar replaceable since
896 // pointer to the base (with offset) is passed as argument.
897 //
898 arg = get_addp_base(arg);
899 }
900 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
901 assert(arg_ptn != NULL, "should be registered");
902 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
903 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
904 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
905 aat->isa_ptr() != NULL, "expecting an Ptr");
906 bool arg_has_oops = aat->isa_oopptr() &&
907 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
908 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
909 if (i == TypeFunc::Parms) {
910 src_has_oops = arg_has_oops;
911 }
912 //
913 // src or dst could be j.l.Object when other is basic type array:
914 //
915 // arraycopy(char[],0,Object*,0,size);
916 // arraycopy(Object*,0,char[],0,size);
917 //
918 // Don't add edges in such cases.
919 //
920 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
921 arg_has_oops && (i > TypeFunc::Parms);
922 #ifdef ASSERT
923 if (!(is_arraycopy ||
924 (call->as_CallLeaf()->_name != NULL &&
925 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
926 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
927 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
928 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
929 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
930 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0)
931 ))) {
932 call->dump();
933 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
934 }
935 #endif
936 // Always process arraycopy's destination object since
937 // we need to add all possible edges to references in
938 // source object.
939 if (arg_esc >= PointsToNode::ArgEscape &&
940 !arg_is_arraycopy_dest) {
941 continue;
942 }
943 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
944 if (arg_is_arraycopy_dest) {
945 Node* src = call->in(TypeFunc::Parms);
946 if (src->is_AddP()) {
947 src = get_addp_base(src);
948 }
949 PointsToNode* src_ptn = ptnode_adr(src->_idx);
950 assert(src_ptn != NULL, "should be registered");
951 if (arg_ptn != src_ptn) {
952 // Special arraycopy edge:
953 // A destination object's field can't have the source object
954 // as base since objects escape states are not related.
955 // Only escape state of destination object's fields affects
956 // escape state of fields in source object.
957 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
958 }
959 }
960 }
961 }
962 break;
963 }
964 case Op_CallStaticJava: {
965 // For a static call, we know exactly what method is being called.
966 // Use bytecode estimator to record the call's escape affects
967 #ifdef ASSERT
968 const char* name = call->as_CallStaticJava()->_name;
969 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
970 #endif
971 ciMethod* meth = call->as_CallJava()->method();
972 if ((meth != NULL) && meth->is_boxing_method()) {
973 break; // Boxing methods do not modify any oops.
974 }
975 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
976 // fall-through if not a Java method or no analyzer information
977 if (call_analyzer != NULL) {
978 PointsToNode* call_ptn = ptnode_adr(call->_idx);
979 const TypeTuple* d = call->tf()->domain();
980 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
981 const Type* at = d->field_at(i);
982 int k = i - TypeFunc::Parms;
983 Node* arg = call->in(i);
984 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
985 if (at->isa_ptr() != NULL &&
986 call_analyzer->is_arg_returned(k)) {
987 // The call returns arguments.
988 if (call_ptn != NULL) { // Is call's result used?
989 assert(call_ptn->is_LocalVar(), "node should be registered");
990 assert(arg_ptn != NULL, "node should be registered");
991 add_edge(call_ptn, arg_ptn);
992 }
993 }
994 if (at->isa_oopptr() != NULL &&
995 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
996 if (!call_analyzer->is_arg_stack(k)) {
997 // The argument global escapes
998 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
999 } else {
1000 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1001 if (!call_analyzer->is_arg_local(k)) {
1002 // The argument itself doesn't escape, but any fields might
1003 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1004 }
1005 }
1006 }
1007 }
1008 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1009 // The call returns arguments.
1010 assert(call_ptn->edge_count() > 0, "sanity");
1011 if (!call_analyzer->is_return_local()) {
1012 // Returns also unknown object.
1013 add_edge(call_ptn, phantom_obj);
1014 }
1015 }
1016 break;
1017 }
1018 }
1019 default: {
1020 // Fall-through here if not a Java method or no analyzer information
1021 // or some other type of call, assume the worst case: all arguments
1022 // globally escape.
1023 const TypeTuple* d = call->tf()->domain();
1024 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1025 const Type* at = d->field_at(i);
1026 if (at->isa_oopptr() != NULL) {
1027 Node* arg = call->in(i);
1028 if (arg->is_AddP()) {
1029 arg = get_addp_base(arg);
1030 }
1031 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1032 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1033 }
1034 }
1035 }
1036 }
1037 }
1040 // Finish Graph construction.
1041 bool ConnectionGraph::complete_connection_graph(
1042 GrowableArray<PointsToNode*>& ptnodes_worklist,
1043 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1044 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1045 GrowableArray<FieldNode*>& oop_fields_worklist) {
1046 // Normally only 1-3 passes needed to build Connection Graph depending
1047 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1048 // Set limit to 20 to catch situation when something did go wrong and
1049 // bailout Escape Analysis.
1050 // Also limit build time to 30 sec (60 in debug VM).
1051 #define CG_BUILD_ITER_LIMIT 20
1052 #ifdef ASSERT
1053 #define CG_BUILD_TIME_LIMIT 60.0
1054 #else
1055 #define CG_BUILD_TIME_LIMIT 30.0
1056 #endif
1058 // Propagate GlobalEscape and ArgEscape escape states and check that
1059 // we still have non-escaping objects. The method pushs on _worklist
1060 // Field nodes which reference phantom_object.
1061 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1062 return false; // Nothing to do.
1063 }
1064 // Now propagate references to all JavaObject nodes.
1065 int java_objects_length = java_objects_worklist.length();
1066 elapsedTimer time;
1067 int new_edges = 1;
1068 int iterations = 0;
1069 do {
1070 while ((new_edges > 0) &&
1071 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1072 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1073 time.start();
1074 new_edges = 0;
1075 // Propagate references to phantom_object for nodes pushed on _worklist
1076 // by find_non_escaped_objects() and find_field_value().
1077 new_edges += add_java_object_edges(phantom_obj, false);
1078 for (int next = 0; next < java_objects_length; ++next) {
1079 JavaObjectNode* ptn = java_objects_worklist.at(next);
1080 new_edges += add_java_object_edges(ptn, true);
1081 }
1082 if (new_edges > 0) {
1083 // Update escape states on each iteration if graph was updated.
1084 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1085 return false; // Nothing to do.
1086 }
1087 }
1088 time.stop();
1089 }
1090 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1091 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1092 time.start();
1093 // Find fields which have unknown value.
1094 int fields_length = oop_fields_worklist.length();
1095 for (int next = 0; next < fields_length; next++) {
1096 FieldNode* field = oop_fields_worklist.at(next);
1097 if (field->edge_count() == 0) {
1098 new_edges += find_field_value(field);
1099 // This code may added new edges to phantom_object.
1100 // Need an other cycle to propagate references to phantom_object.
1101 }
1102 }
1103 time.stop();
1104 } else {
1105 new_edges = 0; // Bailout
1106 }
1107 } while (new_edges > 0);
1109 // Bailout if passed limits.
1110 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1111 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1112 Compile* C = _compile;
1113 if (C->log() != NULL) {
1114 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1115 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1116 C->log()->end_elem(" limit'");
1117 }
1118 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1119 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1120 // Possible infinite build_connection_graph loop,
1121 // bailout (no changes to ideal graph were made).
1122 return false;
1123 }
1124 #ifdef ASSERT
1125 if (Verbose && PrintEscapeAnalysis) {
1126 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1127 iterations, nodes_size(), ptnodes_worklist.length());
1128 }
1129 #endif
1131 #undef CG_BUILD_ITER_LIMIT
1132 #undef CG_BUILD_TIME_LIMIT
1134 // Find fields initialized by NULL for non-escaping Allocations.
1135 int non_escaped_length = non_escaped_worklist.length();
1136 for (int next = 0; next < non_escaped_length; next++) {
1137 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1138 PointsToNode::EscapeState es = ptn->escape_state();
1139 assert(es <= PointsToNode::ArgEscape, "sanity");
1140 if (es == PointsToNode::NoEscape) {
1141 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1142 // Adding references to NULL object does not change escape states
1143 // since it does not escape. Also no fields are added to NULL object.
1144 add_java_object_edges(null_obj, false);
1145 }
1146 }
1147 Node* n = ptn->ideal_node();
1148 if (n->is_Allocate()) {
1149 // The object allocated by this Allocate node will never be
1150 // seen by an other thread. Mark it so that when it is
1151 // expanded no MemBarStoreStore is added.
1152 InitializeNode* ini = n->as_Allocate()->initialization();
1153 if (ini != NULL)
1154 ini->set_does_not_escape();
1155 }
1156 }
1157 return true; // Finished graph construction.
1158 }
1160 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1161 // and check that we still have non-escaping java objects.
1162 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1163 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1164 GrowableArray<PointsToNode*> escape_worklist;
1165 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1166 int ptnodes_length = ptnodes_worklist.length();
1167 for (int next = 0; next < ptnodes_length; ++next) {
1168 PointsToNode* ptn = ptnodes_worklist.at(next);
1169 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1170 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1171 escape_worklist.push(ptn);
1172 }
1173 }
1174 // Set escape states to referenced nodes (edges list).
1175 while (escape_worklist.length() > 0) {
1176 PointsToNode* ptn = escape_worklist.pop();
1177 PointsToNode::EscapeState es = ptn->escape_state();
1178 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1179 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1180 es >= PointsToNode::ArgEscape) {
1181 // GlobalEscape or ArgEscape state of field means it has unknown value.
1182 if (add_edge(ptn, phantom_obj)) {
1183 // New edge was added
1184 add_field_uses_to_worklist(ptn->as_Field());
1185 }
1186 }
1187 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1188 PointsToNode* e = i.get();
1189 if (e->is_Arraycopy()) {
1190 assert(ptn->arraycopy_dst(), "sanity");
1191 // Propagate only fields escape state through arraycopy edge.
1192 if (e->fields_escape_state() < field_es) {
1193 set_fields_escape_state(e, field_es);
1194 escape_worklist.push(e);
1195 }
1196 } else if (es >= field_es) {
1197 // fields_escape_state is also set to 'es' if it is less than 'es'.
1198 if (e->escape_state() < es) {
1199 set_escape_state(e, es);
1200 escape_worklist.push(e);
1201 }
1202 } else {
1203 // Propagate field escape state.
1204 bool es_changed = false;
1205 if (e->fields_escape_state() < field_es) {
1206 set_fields_escape_state(e, field_es);
1207 es_changed = true;
1208 }
1209 if ((e->escape_state() < field_es) &&
1210 e->is_Field() && ptn->is_JavaObject() &&
1211 e->as_Field()->is_oop()) {
1212 // Change escape state of referenced fileds.
1213 set_escape_state(e, field_es);
1214 es_changed = true;;
1215 } else if (e->escape_state() < es) {
1216 set_escape_state(e, es);
1217 es_changed = true;;
1218 }
1219 if (es_changed) {
1220 escape_worklist.push(e);
1221 }
1222 }
1223 }
1224 }
1225 // Remove escaped objects from non_escaped list.
1226 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1227 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1228 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1229 non_escaped_worklist.delete_at(next);
1230 }
1231 if (ptn->escape_state() == PointsToNode::NoEscape) {
1232 // Find fields in non-escaped allocations which have unknown value.
1233 find_init_values(ptn, phantom_obj, NULL);
1234 }
1235 }
1236 return (non_escaped_worklist.length() > 0);
1237 }
1239 // Add all references to JavaObject node by walking over all uses.
1240 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1241 int new_edges = 0;
1242 if (populate_worklist) {
1243 // Populate _worklist by uses of jobj's uses.
1244 for (UseIterator i(jobj); i.has_next(); i.next()) {
1245 PointsToNode* use = i.get();
1246 if (use->is_Arraycopy())
1247 continue;
1248 add_uses_to_worklist(use);
1249 if (use->is_Field() && use->as_Field()->is_oop()) {
1250 // Put on worklist all field's uses (loads) and
1251 // related field nodes (same base and offset).
1252 add_field_uses_to_worklist(use->as_Field());
1253 }
1254 }
1255 }
1256 while(_worklist.length() > 0) {
1257 PointsToNode* use = _worklist.pop();
1258 if (PointsToNode::is_base_use(use)) {
1259 // Add reference from jobj to field and from field to jobj (field's base).
1260 use = PointsToNode::get_use_node(use)->as_Field();
1261 if (add_base(use->as_Field(), jobj)) {
1262 new_edges++;
1263 }
1264 continue;
1265 }
1266 assert(!use->is_JavaObject(), "sanity");
1267 if (use->is_Arraycopy()) {
1268 if (jobj == null_obj) // NULL object does not have field edges
1269 continue;
1270 // Added edge from Arraycopy node to arraycopy's source java object
1271 if (add_edge(use, jobj)) {
1272 jobj->set_arraycopy_src();
1273 new_edges++;
1274 }
1275 // and stop here.
1276 continue;
1277 }
1278 if (!add_edge(use, jobj))
1279 continue; // No new edge added, there was such edge already.
1280 new_edges++;
1281 if (use->is_LocalVar()) {
1282 add_uses_to_worklist(use);
1283 if (use->arraycopy_dst()) {
1284 for (EdgeIterator i(use); i.has_next(); i.next()) {
1285 PointsToNode* e = i.get();
1286 if (e->is_Arraycopy()) {
1287 if (jobj == null_obj) // NULL object does not have field edges
1288 continue;
1289 // Add edge from arraycopy's destination java object to Arraycopy node.
1290 if (add_edge(jobj, e)) {
1291 new_edges++;
1292 jobj->set_arraycopy_dst();
1293 }
1294 }
1295 }
1296 }
1297 } else {
1298 // Added new edge to stored in field values.
1299 // Put on worklist all field's uses (loads) and
1300 // related field nodes (same base and offset).
1301 add_field_uses_to_worklist(use->as_Field());
1302 }
1303 }
1304 return new_edges;
1305 }
1307 // Put on worklist all related field nodes.
1308 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1309 assert(field->is_oop(), "sanity");
1310 int offset = field->offset();
1311 add_uses_to_worklist(field);
1312 // Loop over all bases of this field and push on worklist Field nodes
1313 // with the same offset and base (since they may reference the same field).
1314 for (BaseIterator i(field); i.has_next(); i.next()) {
1315 PointsToNode* base = i.get();
1316 add_fields_to_worklist(field, base);
1317 // Check if the base was source object of arraycopy and go over arraycopy's
1318 // destination objects since values stored to a field of source object are
1319 // accessable by uses (loads) of fields of destination objects.
1320 if (base->arraycopy_src()) {
1321 for (UseIterator j(base); j.has_next(); j.next()) {
1322 PointsToNode* arycp = j.get();
1323 if (arycp->is_Arraycopy()) {
1324 for (UseIterator k(arycp); k.has_next(); k.next()) {
1325 PointsToNode* abase = k.get();
1326 if (abase->arraycopy_dst() && abase != base) {
1327 // Look for the same arracopy reference.
1328 add_fields_to_worklist(field, abase);
1329 }
1330 }
1331 }
1332 }
1333 }
1334 }
1335 }
1337 // Put on worklist all related field nodes.
1338 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1339 int offset = field->offset();
1340 if (base->is_LocalVar()) {
1341 for (UseIterator j(base); j.has_next(); j.next()) {
1342 PointsToNode* f = j.get();
1343 if (PointsToNode::is_base_use(f)) { // Field
1344 f = PointsToNode::get_use_node(f);
1345 if (f == field || !f->as_Field()->is_oop())
1346 continue;
1347 int offs = f->as_Field()->offset();
1348 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1349 add_to_worklist(f);
1350 }
1351 }
1352 }
1353 } else {
1354 assert(base->is_JavaObject(), "sanity");
1355 if (// Skip phantom_object since it is only used to indicate that
1356 // this field's content globally escapes.
1357 (base != phantom_obj) &&
1358 // NULL object node does not have fields.
1359 (base != null_obj)) {
1360 for (EdgeIterator i(base); i.has_next(); i.next()) {
1361 PointsToNode* f = i.get();
1362 // Skip arraycopy edge since store to destination object field
1363 // does not update value in source object field.
1364 if (f->is_Arraycopy()) {
1365 assert(base->arraycopy_dst(), "sanity");
1366 continue;
1367 }
1368 if (f == field || !f->as_Field()->is_oop())
1369 continue;
1370 int offs = f->as_Field()->offset();
1371 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1372 add_to_worklist(f);
1373 }
1374 }
1375 }
1376 }
1377 }
1379 // Find fields which have unknown value.
1380 int ConnectionGraph::find_field_value(FieldNode* field) {
1381 // Escaped fields should have init value already.
1382 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1383 int new_edges = 0;
1384 for (BaseIterator i(field); i.has_next(); i.next()) {
1385 PointsToNode* base = i.get();
1386 if (base->is_JavaObject()) {
1387 // Skip Allocate's fields which will be processed later.
1388 if (base->ideal_node()->is_Allocate())
1389 return 0;
1390 assert(base == null_obj, "only NULL ptr base expected here");
1391 }
1392 }
1393 if (add_edge(field, phantom_obj)) {
1394 // New edge was added
1395 new_edges++;
1396 add_field_uses_to_worklist(field);
1397 }
1398 return new_edges;
1399 }
1401 // Find fields initializing values for allocations.
1402 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1403 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1404 int new_edges = 0;
1405 Node* alloc = pta->ideal_node();
1406 if (init_val == phantom_obj) {
1407 // Do nothing for Allocate nodes since its fields values are "known".
1408 if (alloc->is_Allocate())
1409 return 0;
1410 assert(alloc->as_CallStaticJava(), "sanity");
1411 #ifdef ASSERT
1412 if (alloc->as_CallStaticJava()->method() == NULL) {
1413 const char* name = alloc->as_CallStaticJava()->_name;
1414 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1415 }
1416 #endif
1417 // Non-escaped allocation returned from Java or runtime call have
1418 // unknown values in fields.
1419 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1420 PointsToNode* field = i.get();
1421 if (field->is_Field() && field->as_Field()->is_oop()) {
1422 if (add_edge(field, phantom_obj)) {
1423 // New edge was added
1424 new_edges++;
1425 add_field_uses_to_worklist(field->as_Field());
1426 }
1427 }
1428 }
1429 return new_edges;
1430 }
1431 assert(init_val == null_obj, "sanity");
1432 // Do nothing for Call nodes since its fields values are unknown.
1433 if (!alloc->is_Allocate())
1434 return 0;
1436 InitializeNode* ini = alloc->as_Allocate()->initialization();
1437 Compile* C = _compile;
1438 bool visited_bottom_offset = false;
1439 GrowableArray<int> offsets_worklist;
1441 // Check if an oop field's initializing value is recorded and add
1442 // a corresponding NULL if field's value if it is not recorded.
1443 // Connection Graph does not record a default initialization by NULL
1444 // captured by Initialize node.
1445 //
1446 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1447 PointsToNode* field = i.get(); // Field (AddP)
1448 if (!field->is_Field() || !field->as_Field()->is_oop())
1449 continue; // Not oop field
1450 int offset = field->as_Field()->offset();
1451 if (offset == Type::OffsetBot) {
1452 if (!visited_bottom_offset) {
1453 // OffsetBot is used to reference array's element,
1454 // always add reference to NULL to all Field nodes since we don't
1455 // known which element is referenced.
1456 if (add_edge(field, null_obj)) {
1457 // New edge was added
1458 new_edges++;
1459 add_field_uses_to_worklist(field->as_Field());
1460 visited_bottom_offset = true;
1461 }
1462 }
1463 } else {
1464 // Check only oop fields.
1465 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1466 if (adr_type->isa_rawptr()) {
1467 #ifdef ASSERT
1468 // Raw pointers are used for initializing stores so skip it
1469 // since it should be recorded already
1470 Node* base = get_addp_base(field->ideal_node());
1471 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1472 (base->in(0) == alloc),"unexpected pointer type");
1473 #endif
1474 continue;
1475 }
1476 if (!offsets_worklist.contains(offset)) {
1477 offsets_worklist.append(offset);
1478 Node* value = NULL;
1479 if (ini != NULL) {
1480 // StoreP::memory_type() == T_ADDRESS
1481 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1482 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1483 // Make sure initializing store has the same type as this AddP.
1484 // This AddP may reference non existing field because it is on a
1485 // dead branch of bimorphic call which is not eliminated yet.
1486 if (store != NULL && store->is_Store() &&
1487 store->as_Store()->memory_type() == ft) {
1488 value = store->in(MemNode::ValueIn);
1489 #ifdef ASSERT
1490 if (VerifyConnectionGraph) {
1491 // Verify that AddP already points to all objects the value points to.
1492 PointsToNode* val = ptnode_adr(value->_idx);
1493 assert((val != NULL), "should be processed already");
1494 PointsToNode* missed_obj = NULL;
1495 if (val->is_JavaObject()) {
1496 if (!field->points_to(val->as_JavaObject())) {
1497 missed_obj = val;
1498 }
1499 } else {
1500 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1501 tty->print_cr("----------init store has invalid value -----");
1502 store->dump();
1503 val->dump();
1504 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1505 }
1506 for (EdgeIterator j(val); j.has_next(); j.next()) {
1507 PointsToNode* obj = j.get();
1508 if (obj->is_JavaObject()) {
1509 if (!field->points_to(obj->as_JavaObject())) {
1510 missed_obj = obj;
1511 break;
1512 }
1513 }
1514 }
1515 }
1516 if (missed_obj != NULL) {
1517 tty->print_cr("----------field---------------------------------");
1518 field->dump();
1519 tty->print_cr("----------missed referernce to object-----------");
1520 missed_obj->dump();
1521 tty->print_cr("----------object referernced by init store -----");
1522 store->dump();
1523 val->dump();
1524 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1525 }
1526 }
1527 #endif
1528 } else {
1529 // There could be initializing stores which follow allocation.
1530 // For example, a volatile field store is not collected
1531 // by Initialize node.
1532 //
1533 // Need to check for dependent loads to separate such stores from
1534 // stores which follow loads. For now, add initial value NULL so
1535 // that compare pointers optimization works correctly.
1536 }
1537 }
1538 if (value == NULL) {
1539 // A field's initializing value was not recorded. Add NULL.
1540 if (add_edge(field, null_obj)) {
1541 // New edge was added
1542 new_edges++;
1543 add_field_uses_to_worklist(field->as_Field());
1544 }
1545 }
1546 }
1547 }
1548 }
1549 return new_edges;
1550 }
1552 // Adjust scalar_replaceable state after Connection Graph is built.
1553 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1554 // Search for non-escaping objects which are not scalar replaceable
1555 // and mark them to propagate the state to referenced objects.
1557 // 1. An object is not scalar replaceable if the field into which it is
1558 // stored has unknown offset (stored into unknown element of an array).
1559 //
1560 for (UseIterator i(jobj); i.has_next(); i.next()) {
1561 PointsToNode* use = i.get();
1562 assert(!use->is_Arraycopy(), "sanity");
1563 if (use->is_Field()) {
1564 FieldNode* field = use->as_Field();
1565 assert(field->is_oop() && field->scalar_replaceable() &&
1566 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1567 if (field->offset() == Type::OffsetBot) {
1568 jobj->set_scalar_replaceable(false);
1569 return;
1570 }
1571 }
1572 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1573 // 2. An object is not scalar replaceable if it is merged with other objects.
1574 for (EdgeIterator j(use); j.has_next(); j.next()) {
1575 PointsToNode* ptn = j.get();
1576 if (ptn->is_JavaObject() && ptn != jobj) {
1577 // Mark all objects.
1578 jobj->set_scalar_replaceable(false);
1579 ptn->set_scalar_replaceable(false);
1580 }
1581 }
1582 if (!jobj->scalar_replaceable()) {
1583 return;
1584 }
1585 }
1587 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1588 // Non-escaping object node should point only to field nodes.
1589 FieldNode* field = j.get()->as_Field();
1590 int offset = field->as_Field()->offset();
1592 // 3. An object is not scalar replaceable if it has a field with unknown
1593 // offset (array's element is accessed in loop).
1594 if (offset == Type::OffsetBot) {
1595 jobj->set_scalar_replaceable(false);
1596 return;
1597 }
1598 // 4. Currently an object is not scalar replaceable if a LoadStore node
1599 // access its field since the field value is unknown after it.
1600 //
1601 Node* n = field->ideal_node();
1602 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1603 if (n->fast_out(i)->is_LoadStore()) {
1604 jobj->set_scalar_replaceable(false);
1605 return;
1606 }
1607 }
1609 // 5. Or the address may point to more then one object. This may produce
1610 // the false positive result (set not scalar replaceable)
1611 // since the flow-insensitive escape analysis can't separate
1612 // the case when stores overwrite the field's value from the case
1613 // when stores happened on different control branches.
1614 //
1615 // Note: it will disable scalar replacement in some cases:
1616 //
1617 // Point p[] = new Point[1];
1618 // p[0] = new Point(); // Will be not scalar replaced
1619 //
1620 // but it will save us from incorrect optimizations in next cases:
1621 //
1622 // Point p[] = new Point[1];
1623 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1624 //
1625 if (field->base_count() > 1) {
1626 for (BaseIterator i(field); i.has_next(); i.next()) {
1627 PointsToNode* base = i.get();
1628 // Don't take into account LocalVar nodes which
1629 // may point to only one object which should be also
1630 // this field's base by now.
1631 if (base->is_JavaObject() && base != jobj) {
1632 // Mark all bases.
1633 jobj->set_scalar_replaceable(false);
1634 base->set_scalar_replaceable(false);
1635 }
1636 }
1637 }
1638 }
1639 }
1641 #ifdef ASSERT
1642 void ConnectionGraph::verify_connection_graph(
1643 GrowableArray<PointsToNode*>& ptnodes_worklist,
1644 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1645 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1646 GrowableArray<Node*>& addp_worklist) {
1647 // Verify that graph is complete - no new edges could be added.
1648 int java_objects_length = java_objects_worklist.length();
1649 int non_escaped_length = non_escaped_worklist.length();
1650 int new_edges = 0;
1651 for (int next = 0; next < java_objects_length; ++next) {
1652 JavaObjectNode* ptn = java_objects_worklist.at(next);
1653 new_edges += add_java_object_edges(ptn, true);
1654 }
1655 assert(new_edges == 0, "graph was not complete");
1656 // Verify that escape state is final.
1657 int length = non_escaped_worklist.length();
1658 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1659 assert((non_escaped_length == non_escaped_worklist.length()) &&
1660 (non_escaped_length == length) &&
1661 (_worklist.length() == 0), "escape state was not final");
1663 // Verify fields information.
1664 int addp_length = addp_worklist.length();
1665 for (int next = 0; next < addp_length; ++next ) {
1666 Node* n = addp_worklist.at(next);
1667 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1668 if (field->is_oop()) {
1669 // Verify that field has all bases
1670 Node* base = get_addp_base(n);
1671 PointsToNode* ptn = ptnode_adr(base->_idx);
1672 if (ptn->is_JavaObject()) {
1673 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1674 } else {
1675 assert(ptn->is_LocalVar(), "sanity");
1676 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1677 PointsToNode* e = i.get();
1678 if (e->is_JavaObject()) {
1679 assert(field->has_base(e->as_JavaObject()), "sanity");
1680 }
1681 }
1682 }
1683 // Verify that all fields have initializing values.
1684 if (field->edge_count() == 0) {
1685 tty->print_cr("----------field does not have references----------");
1686 field->dump();
1687 for (BaseIterator i(field); i.has_next(); i.next()) {
1688 PointsToNode* base = i.get();
1689 tty->print_cr("----------field has next base---------------------");
1690 base->dump();
1691 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1692 tty->print_cr("----------base has fields-------------------------");
1693 for (EdgeIterator j(base); j.has_next(); j.next()) {
1694 j.get()->dump();
1695 }
1696 tty->print_cr("----------base has references---------------------");
1697 for (UseIterator j(base); j.has_next(); j.next()) {
1698 j.get()->dump();
1699 }
1700 }
1701 }
1702 for (UseIterator i(field); i.has_next(); i.next()) {
1703 i.get()->dump();
1704 }
1705 assert(field->edge_count() > 0, "sanity");
1706 }
1707 }
1708 }
1709 }
1710 #endif
1712 // Optimize ideal graph.
1713 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1714 GrowableArray<Node*>& storestore_worklist) {
1715 Compile* C = _compile;
1716 PhaseIterGVN* igvn = _igvn;
1717 if (EliminateLocks) {
1718 // Mark locks before changing ideal graph.
1719 int cnt = C->macro_count();
1720 for( int i=0; i < cnt; i++ ) {
1721 Node *n = C->macro_node(i);
1722 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1723 AbstractLockNode* alock = n->as_AbstractLock();
1724 if (!alock->is_non_esc_obj()) {
1725 if (not_global_escape(alock->obj_node())) {
1726 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1727 // The lock could be marked eliminated by lock coarsening
1728 // code during first IGVN before EA. Replace coarsened flag
1729 // to eliminate all associated locks/unlocks.
1730 alock->set_non_esc_obj();
1731 }
1732 }
1733 }
1734 }
1735 }
1737 if (OptimizePtrCompare) {
1738 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1739 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1740 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1741 // Optimize objects compare.
1742 while (ptr_cmp_worklist.length() != 0) {
1743 Node *n = ptr_cmp_worklist.pop();
1744 Node *res = optimize_ptr_compare(n);
1745 if (res != NULL) {
1746 #ifndef PRODUCT
1747 if (PrintOptimizePtrCompare) {
1748 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"));
1749 if (Verbose) {
1750 n->dump(1);
1751 }
1752 }
1753 #endif
1754 igvn->replace_node(n, res);
1755 }
1756 }
1757 // cleanup
1758 if (_pcmp_neq->outcnt() == 0)
1759 igvn->hash_delete(_pcmp_neq);
1760 if (_pcmp_eq->outcnt() == 0)
1761 igvn->hash_delete(_pcmp_eq);
1762 }
1764 // For MemBarStoreStore nodes added in library_call.cpp, check
1765 // escape status of associated AllocateNode and optimize out
1766 // MemBarStoreStore node if the allocated object never escapes.
1767 while (storestore_worklist.length() != 0) {
1768 Node *n = storestore_worklist.pop();
1769 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1770 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1771 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1772 if (not_global_escape(alloc)) {
1773 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1774 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1775 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1776 igvn->register_new_node_with_optimizer(mb);
1777 igvn->replace_node(storestore, mb);
1778 }
1779 }
1780 }
1782 // Optimize objects compare.
1783 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1784 assert(OptimizePtrCompare, "sanity");
1785 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1786 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1787 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1788 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1789 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1790 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1792 // Check simple cases first.
1793 if (jobj1 != NULL) {
1794 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1795 if (jobj1 == jobj2) {
1796 // Comparing the same not escaping object.
1797 return _pcmp_eq;
1798 }
1799 Node* obj = jobj1->ideal_node();
1800 // Comparing not escaping allocation.
1801 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1802 !ptn2->points_to(jobj1)) {
1803 return _pcmp_neq; // This includes nullness check.
1804 }
1805 }
1806 }
1807 if (jobj2 != NULL) {
1808 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1809 Node* obj = jobj2->ideal_node();
1810 // Comparing not escaping allocation.
1811 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1812 !ptn1->points_to(jobj2)) {
1813 return _pcmp_neq; // This includes nullness check.
1814 }
1815 }
1816 }
1817 if (jobj1 != NULL && jobj1 != phantom_obj &&
1818 jobj2 != NULL && jobj2 != phantom_obj &&
1819 jobj1->ideal_node()->is_Con() &&
1820 jobj2->ideal_node()->is_Con()) {
1821 // Klass or String constants compare. Need to be careful with
1822 // compressed pointers - compare types of ConN and ConP instead of nodes.
1823 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1824 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1825 if (t1->make_ptr() == t2->make_ptr()) {
1826 return _pcmp_eq;
1827 } else {
1828 return _pcmp_neq;
1829 }
1830 }
1831 if (ptn1->meet(ptn2)) {
1832 return NULL; // Sets are not disjoint
1833 }
1835 // Sets are disjoint.
1836 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1837 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1838 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1839 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1840 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1841 set2_has_unknown_ptr && set1_has_null_ptr) {
1842 // Check nullness of unknown object.
1843 return NULL;
1844 }
1846 // Disjointness by itself is not sufficient since
1847 // alias analysis is not complete for escaped objects.
1848 // Disjoint sets are definitely unrelated only when
1849 // at least one set has only not escaping allocations.
1850 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1851 if (ptn1->non_escaping_allocation()) {
1852 return _pcmp_neq;
1853 }
1854 }
1855 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1856 if (ptn2->non_escaping_allocation()) {
1857 return _pcmp_neq;
1858 }
1859 }
1860 return NULL;
1861 }
1863 // Connection Graph constuction functions.
1865 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1866 PointsToNode* ptadr = _nodes.at(n->_idx);
1867 if (ptadr != NULL) {
1868 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1869 return;
1870 }
1871 Compile* C = _compile;
1872 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1873 _nodes.at_put(n->_idx, ptadr);
1874 }
1876 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1877 PointsToNode* ptadr = _nodes.at(n->_idx);
1878 if (ptadr != NULL) {
1879 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1880 return;
1881 }
1882 Compile* C = _compile;
1883 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1884 _nodes.at_put(n->_idx, ptadr);
1885 }
1887 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1888 PointsToNode* ptadr = _nodes.at(n->_idx);
1889 if (ptadr != NULL) {
1890 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1891 return;
1892 }
1893 bool unsafe = false;
1894 bool is_oop = is_oop_field(n, offset, &unsafe);
1895 if (unsafe) {
1896 es = PointsToNode::GlobalEscape;
1897 }
1898 Compile* C = _compile;
1899 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1900 _nodes.at_put(n->_idx, field);
1901 }
1903 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1904 PointsToNode* src, PointsToNode* dst) {
1905 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1906 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1907 PointsToNode* ptadr = _nodes.at(n->_idx);
1908 if (ptadr != NULL) {
1909 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1910 return;
1911 }
1912 Compile* C = _compile;
1913 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1914 _nodes.at_put(n->_idx, ptadr);
1915 // Add edge from arraycopy node to source object.
1916 (void)add_edge(ptadr, src);
1917 src->set_arraycopy_src();
1918 // Add edge from destination object to arraycopy node.
1919 (void)add_edge(dst, ptadr);
1920 dst->set_arraycopy_dst();
1921 }
1923 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1924 const Type* adr_type = n->as_AddP()->bottom_type();
1925 BasicType bt = T_INT;
1926 if (offset == Type::OffsetBot) {
1927 // Check only oop fields.
1928 if (!adr_type->isa_aryptr() ||
1929 (adr_type->isa_aryptr()->klass() == NULL) ||
1930 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1931 // OffsetBot is used to reference array's element. Ignore first AddP.
1932 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1933 bt = T_OBJECT;
1934 }
1935 }
1936 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1937 if (adr_type->isa_instptr()) {
1938 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1939 if (field != NULL) {
1940 bt = field->layout_type();
1941 } else {
1942 // Check for unsafe oop field access
1943 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1944 int opcode = n->fast_out(i)->Opcode();
1945 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1946 opcode == Op_StoreN || opcode == Op_LoadN) {
1947 bt = T_OBJECT;
1948 (*unsafe) = true;
1949 break;
1950 }
1951 }
1952 }
1953 } else if (adr_type->isa_aryptr()) {
1954 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1955 // Ignore array length load.
1956 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1957 // Ignore first AddP.
1958 } else {
1959 const Type* elemtype = adr_type->isa_aryptr()->elem();
1960 bt = elemtype->array_element_basic_type();
1961 }
1962 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1963 // Allocation initialization, ThreadLocal field access, unsafe access
1964 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1965 int opcode = n->fast_out(i)->Opcode();
1966 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1967 opcode == Op_StoreN || opcode == Op_LoadN) {
1968 bt = T_OBJECT;
1969 break;
1970 }
1971 }
1972 }
1973 }
1974 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1975 }
1977 // Returns unique pointed java object or NULL.
1978 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1979 assert(!_collecting, "should not call when contructed graph");
1980 // If the node was created after the escape computation we can't answer.
1981 uint idx = n->_idx;
1982 if (idx >= nodes_size()) {
1983 return NULL;
1984 }
1985 PointsToNode* ptn = ptnode_adr(idx);
1986 if (ptn->is_JavaObject()) {
1987 return ptn->as_JavaObject();
1988 }
1989 assert(ptn->is_LocalVar(), "sanity");
1990 // Check all java objects it points to.
1991 JavaObjectNode* jobj = NULL;
1992 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1993 PointsToNode* e = i.get();
1994 if (e->is_JavaObject()) {
1995 if (jobj == NULL) {
1996 jobj = e->as_JavaObject();
1997 } else if (jobj != e) {
1998 return NULL;
1999 }
2000 }
2001 }
2002 return jobj;
2003 }
2005 // Return true if this node points only to non-escaping allocations.
2006 bool PointsToNode::non_escaping_allocation() {
2007 if (is_JavaObject()) {
2008 Node* n = ideal_node();
2009 if (n->is_Allocate() || n->is_CallStaticJava()) {
2010 return (escape_state() == PointsToNode::NoEscape);
2011 } else {
2012 return false;
2013 }
2014 }
2015 assert(is_LocalVar(), "sanity");
2016 // Check all java objects it points to.
2017 for (EdgeIterator i(this); i.has_next(); i.next()) {
2018 PointsToNode* e = i.get();
2019 if (e->is_JavaObject()) {
2020 Node* n = e->ideal_node();
2021 if ((e->escape_state() != PointsToNode::NoEscape) ||
2022 !(n->is_Allocate() || n->is_CallStaticJava())) {
2023 return false;
2024 }
2025 }
2026 }
2027 return true;
2028 }
2030 // Return true if we know the node does not escape globally.
2031 bool ConnectionGraph::not_global_escape(Node *n) {
2032 assert(!_collecting, "should not call during graph construction");
2033 // If the node was created after the escape computation we can't answer.
2034 uint idx = n->_idx;
2035 if (idx >= nodes_size()) {
2036 return false;
2037 }
2038 PointsToNode* ptn = ptnode_adr(idx);
2039 PointsToNode::EscapeState es = ptn->escape_state();
2040 // If we have already computed a value, return it.
2041 if (es >= PointsToNode::GlobalEscape)
2042 return false;
2043 if (ptn->is_JavaObject()) {
2044 return true; // (es < PointsToNode::GlobalEscape);
2045 }
2046 assert(ptn->is_LocalVar(), "sanity");
2047 // Check all java objects it points to.
2048 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2049 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2050 return false;
2051 }
2052 return true;
2053 }
2056 // Helper functions
2058 // Return true if this node points to specified node or nodes it points to.
2059 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2060 if (is_JavaObject()) {
2061 return (this == ptn);
2062 }
2063 assert(is_LocalVar() || is_Field(), "sanity");
2064 for (EdgeIterator i(this); i.has_next(); i.next()) {
2065 if (i.get() == ptn)
2066 return true;
2067 }
2068 return false;
2069 }
2071 // Return true if one node points to an other.
2072 bool PointsToNode::meet(PointsToNode* ptn) {
2073 if (this == ptn) {
2074 return true;
2075 } else if (ptn->is_JavaObject()) {
2076 return this->points_to(ptn->as_JavaObject());
2077 } else if (this->is_JavaObject()) {
2078 return ptn->points_to(this->as_JavaObject());
2079 }
2080 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2081 int ptn_count = ptn->edge_count();
2082 for (EdgeIterator i(this); i.has_next(); i.next()) {
2083 PointsToNode* this_e = i.get();
2084 for (int j = 0; j < ptn_count; j++) {
2085 if (this_e == ptn->edge(j))
2086 return true;
2087 }
2088 }
2089 return false;
2090 }
2092 #ifdef ASSERT
2093 // Return true if bases point to this java object.
2094 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2095 for (BaseIterator i(this); i.has_next(); i.next()) {
2096 if (i.get() == jobj)
2097 return true;
2098 }
2099 return false;
2100 }
2101 #endif
2103 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2104 const Type *adr_type = phase->type(adr);
2105 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2106 adr->in(AddPNode::Address)->is_Proj() &&
2107 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2108 // We are computing a raw address for a store captured by an Initialize
2109 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2110 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2111 assert(offs != Type::OffsetBot ||
2112 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2113 "offset must be a constant or it is initialization of array");
2114 return offs;
2115 }
2116 const TypePtr *t_ptr = adr_type->isa_ptr();
2117 assert(t_ptr != NULL, "must be a pointer type");
2118 return t_ptr->offset();
2119 }
2121 Node* ConnectionGraph::get_addp_base(Node *addp) {
2122 assert(addp->is_AddP(), "must be AddP");
2123 //
2124 // AddP cases for Base and Address inputs:
2125 // case #1. Direct object's field reference:
2126 // Allocate
2127 // |
2128 // Proj #5 ( oop result )
2129 // |
2130 // CheckCastPP (cast to instance type)
2131 // | |
2132 // AddP ( base == address )
2133 //
2134 // case #2. Indirect object's field reference:
2135 // Phi
2136 // |
2137 // CastPP (cast to instance type)
2138 // | |
2139 // AddP ( base == address )
2140 //
2141 // case #3. Raw object's field reference for Initialize node:
2142 // Allocate
2143 // |
2144 // Proj #5 ( oop result )
2145 // top |
2146 // \ |
2147 // AddP ( base == top )
2148 //
2149 // case #4. Array's element reference:
2150 // {CheckCastPP | CastPP}
2151 // | | |
2152 // | AddP ( array's element offset )
2153 // | |
2154 // AddP ( array's offset )
2155 //
2156 // case #5. Raw object's field reference for arraycopy stub call:
2157 // The inline_native_clone() case when the arraycopy stub is called
2158 // after the allocation before Initialize and CheckCastPP nodes.
2159 // Allocate
2160 // |
2161 // Proj #5 ( oop result )
2162 // | |
2163 // AddP ( base == address )
2164 //
2165 // case #6. Constant Pool, ThreadLocal, CastX2P or
2166 // Raw object's field reference:
2167 // {ConP, ThreadLocal, CastX2P, raw Load}
2168 // top |
2169 // \ |
2170 // AddP ( base == top )
2171 //
2172 // case #7. Klass's field reference.
2173 // LoadKlass
2174 // | |
2175 // AddP ( base == address )
2176 //
2177 // case #8. narrow Klass's field reference.
2178 // LoadNKlass
2179 // |
2180 // DecodeN
2181 // | |
2182 // AddP ( base == address )
2183 //
2184 Node *base = addp->in(AddPNode::Base);
2185 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2186 base = addp->in(AddPNode::Address);
2187 while (base->is_AddP()) {
2188 // Case #6 (unsafe access) may have several chained AddP nodes.
2189 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2190 base = base->in(AddPNode::Address);
2191 }
2192 Node* uncast_base = base->uncast();
2193 int opcode = uncast_base->Opcode();
2194 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2195 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2196 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
2197 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2198 }
2199 return base;
2200 }
2202 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2203 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2204 Node* addp2 = addp->raw_out(0);
2205 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2206 addp2->in(AddPNode::Base) == n &&
2207 addp2->in(AddPNode::Address) == addp) {
2208 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2209 //
2210 // Find array's offset to push it on worklist first and
2211 // as result process an array's element offset first (pushed second)
2212 // to avoid CastPP for the array's offset.
2213 // Otherwise the inserted CastPP (LocalVar) will point to what
2214 // the AddP (Field) points to. Which would be wrong since
2215 // the algorithm expects the CastPP has the same point as
2216 // as AddP's base CheckCastPP (LocalVar).
2217 //
2218 // ArrayAllocation
2219 // |
2220 // CheckCastPP
2221 // |
2222 // memProj (from ArrayAllocation CheckCastPP)
2223 // | ||
2224 // | || Int (element index)
2225 // | || | ConI (log(element size))
2226 // | || | /
2227 // | || LShift
2228 // | || /
2229 // | AddP (array's element offset)
2230 // | |
2231 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2232 // | / /
2233 // AddP (array's offset)
2234 // |
2235 // Load/Store (memory operation on array's element)
2236 //
2237 return addp2;
2238 }
2239 return NULL;
2240 }
2242 //
2243 // Adjust the type and inputs of an AddP which computes the
2244 // address of a field of an instance
2245 //
2246 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2247 PhaseGVN* igvn = _igvn;
2248 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2249 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2250 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2251 if (t == NULL) {
2252 // We are computing a raw address for a store captured by an Initialize
2253 // compute an appropriate address type (cases #3 and #5).
2254 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2255 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2256 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2257 assert(offs != Type::OffsetBot, "offset must be a constant");
2258 t = base_t->add_offset(offs)->is_oopptr();
2259 }
2260 int inst_id = base_t->instance_id();
2261 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2262 "old type must be non-instance or match new type");
2264 // The type 't' could be subclass of 'base_t'.
2265 // As result t->offset() could be large then base_t's size and it will
2266 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2267 // constructor verifies correctness of the offset.
2268 //
2269 // It could happened on subclass's branch (from the type profiling
2270 // inlining) which was not eliminated during parsing since the exactness
2271 // of the allocation type was not propagated to the subclass type check.
2272 //
2273 // Or the type 't' could be not related to 'base_t' at all.
2274 // It could happened when CHA type is different from MDO type on a dead path
2275 // (for example, from instanceof check) which is not collapsed during parsing.
2276 //
2277 // Do nothing for such AddP node and don't process its users since
2278 // this code branch will go away.
2279 //
2280 if (!t->is_known_instance() &&
2281 !base_t->klass()->is_subtype_of(t->klass())) {
2282 return false; // bail out
2283 }
2284 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2285 // Do NOT remove the next line: ensure a new alias index is allocated
2286 // for the instance type. Note: C++ will not remove it since the call
2287 // has side effect.
2288 int alias_idx = _compile->get_alias_index(tinst);
2289 igvn->set_type(addp, tinst);
2290 // record the allocation in the node map
2291 set_map(addp, get_map(base->_idx));
2292 // Set addp's Base and Address to 'base'.
2293 Node *abase = addp->in(AddPNode::Base);
2294 Node *adr = addp->in(AddPNode::Address);
2295 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2296 adr->in(0)->_idx == (uint)inst_id) {
2297 // Skip AddP cases #3 and #5.
2298 } else {
2299 assert(!abase->is_top(), "sanity"); // AddP case #3
2300 if (abase != base) {
2301 igvn->hash_delete(addp);
2302 addp->set_req(AddPNode::Base, base);
2303 if (abase == adr) {
2304 addp->set_req(AddPNode::Address, base);
2305 } else {
2306 // AddP case #4 (adr is array's element offset AddP node)
2307 #ifdef ASSERT
2308 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2309 assert(adr->is_AddP() && atype != NULL &&
2310 atype->instance_id() == inst_id, "array's element offset should be processed first");
2311 #endif
2312 }
2313 igvn->hash_insert(addp);
2314 }
2315 }
2316 // Put on IGVN worklist since at least addp's type was changed above.
2317 record_for_optimizer(addp);
2318 return true;
2319 }
2321 //
2322 // Create a new version of orig_phi if necessary. Returns either the newly
2323 // created phi or an existing phi. Sets create_new to indicate whether a new
2324 // phi was created. Cache the last newly created phi in the node map.
2325 //
2326 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2327 Compile *C = _compile;
2328 PhaseGVN* igvn = _igvn;
2329 new_created = false;
2330 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2331 // nothing to do if orig_phi is bottom memory or matches alias_idx
2332 if (phi_alias_idx == alias_idx) {
2333 return orig_phi;
2334 }
2335 // Have we recently created a Phi for this alias index?
2336 PhiNode *result = get_map_phi(orig_phi->_idx);
2337 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2338 return result;
2339 }
2340 // Previous check may fail when the same wide memory Phi was split into Phis
2341 // for different memory slices. Search all Phis for this region.
2342 if (result != NULL) {
2343 Node* region = orig_phi->in(0);
2344 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2345 Node* phi = region->fast_out(i);
2346 if (phi->is_Phi() &&
2347 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2348 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2349 return phi->as_Phi();
2350 }
2351 }
2352 }
2353 if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2354 if (C->do_escape_analysis() == true && !C->failing()) {
2355 // Retry compilation without escape analysis.
2356 // If this is the first failure, the sentinel string will "stick"
2357 // to the Compile object, and the C2Compiler will see it and retry.
2358 C->record_failure(C2Compiler::retry_no_escape_analysis());
2359 }
2360 return NULL;
2361 }
2362 orig_phi_worklist.append_if_missing(orig_phi);
2363 const TypePtr *atype = C->get_adr_type(alias_idx);
2364 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2365 C->copy_node_notes_to(result, orig_phi);
2366 igvn->set_type(result, result->bottom_type());
2367 record_for_optimizer(result);
2368 set_map(orig_phi, result);
2369 new_created = true;
2370 return result;
2371 }
2373 //
2374 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2375 // specified alias index.
2376 //
2377 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2378 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2379 Compile *C = _compile;
2380 PhaseGVN* igvn = _igvn;
2381 bool new_phi_created;
2382 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2383 if (!new_phi_created) {
2384 return result;
2385 }
2386 GrowableArray<PhiNode *> phi_list;
2387 GrowableArray<uint> cur_input;
2388 PhiNode *phi = orig_phi;
2389 uint idx = 1;
2390 bool finished = false;
2391 while(!finished) {
2392 while (idx < phi->req()) {
2393 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2394 if (mem != NULL && mem->is_Phi()) {
2395 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2396 if (new_phi_created) {
2397 // found an phi for which we created a new split, push current one on worklist and begin
2398 // processing new one
2399 phi_list.push(phi);
2400 cur_input.push(idx);
2401 phi = mem->as_Phi();
2402 result = newphi;
2403 idx = 1;
2404 continue;
2405 } else {
2406 mem = newphi;
2407 }
2408 }
2409 if (C->failing()) {
2410 return NULL;
2411 }
2412 result->set_req(idx++, mem);
2413 }
2414 #ifdef ASSERT
2415 // verify that the new Phi has an input for each input of the original
2416 assert( phi->req() == result->req(), "must have same number of inputs.");
2417 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2418 #endif
2419 // Check if all new phi's inputs have specified alias index.
2420 // Otherwise use old phi.
2421 for (uint i = 1; i < phi->req(); i++) {
2422 Node* in = result->in(i);
2423 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2424 }
2425 // we have finished processing a Phi, see if there are any more to do
2426 finished = (phi_list.length() == 0 );
2427 if (!finished) {
2428 phi = phi_list.pop();
2429 idx = cur_input.pop();
2430 PhiNode *prev_result = get_map_phi(phi->_idx);
2431 prev_result->set_req(idx++, result);
2432 result = prev_result;
2433 }
2434 }
2435 return result;
2436 }
2438 //
2439 // The next methods are derived from methods in MemNode.
2440 //
2441 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2442 Node *mem = mmem;
2443 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2444 // means an array I have not precisely typed yet. Do not do any
2445 // alias stuff with it any time soon.
2446 if (toop->base() != Type::AnyPtr &&
2447 !(toop->klass() != NULL &&
2448 toop->klass()->is_java_lang_Object() &&
2449 toop->offset() == Type::OffsetBot)) {
2450 mem = mmem->memory_at(alias_idx);
2451 // Update input if it is progress over what we have now
2452 }
2453 return mem;
2454 }
2456 //
2457 // Move memory users to their memory slices.
2458 //
2459 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2460 Compile* C = _compile;
2461 PhaseGVN* igvn = _igvn;
2462 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2463 assert(tp != NULL, "ptr type");
2464 int alias_idx = C->get_alias_index(tp);
2465 int general_idx = C->get_general_index(alias_idx);
2467 // Move users first
2468 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2469 Node* use = n->fast_out(i);
2470 if (use->is_MergeMem()) {
2471 MergeMemNode* mmem = use->as_MergeMem();
2472 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2473 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2474 continue; // Nothing to do
2475 }
2476 // Replace previous general reference to mem node.
2477 uint orig_uniq = C->unique();
2478 Node* m = find_inst_mem(n, general_idx, orig_phis);
2479 assert(orig_uniq == C->unique(), "no new nodes");
2480 mmem->set_memory_at(general_idx, m);
2481 --imax;
2482 --i;
2483 } else if (use->is_MemBar()) {
2484 assert(!use->is_Initialize(), "initializing stores should not be moved");
2485 if (use->req() > MemBarNode::Precedent &&
2486 use->in(MemBarNode::Precedent) == n) {
2487 // Don't move related membars.
2488 record_for_optimizer(use);
2489 continue;
2490 }
2491 tp = use->as_MemBar()->adr_type()->isa_ptr();
2492 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2493 alias_idx == general_idx) {
2494 continue; // Nothing to do
2495 }
2496 // Move to general memory slice.
2497 uint orig_uniq = C->unique();
2498 Node* m = find_inst_mem(n, general_idx, orig_phis);
2499 assert(orig_uniq == C->unique(), "no new nodes");
2500 igvn->hash_delete(use);
2501 imax -= use->replace_edge(n, m);
2502 igvn->hash_insert(use);
2503 record_for_optimizer(use);
2504 --i;
2505 #ifdef ASSERT
2506 } else if (use->is_Mem()) {
2507 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2508 // Don't move related cardmark.
2509 continue;
2510 }
2511 // Memory nodes should have new memory input.
2512 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2513 assert(tp != NULL, "ptr type");
2514 int idx = C->get_alias_index(tp);
2515 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2516 "Following memory nodes should have new memory input or be on the same memory slice");
2517 } else if (use->is_Phi()) {
2518 // Phi nodes should be split and moved already.
2519 tp = use->as_Phi()->adr_type()->isa_ptr();
2520 assert(tp != NULL, "ptr type");
2521 int idx = C->get_alias_index(tp);
2522 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2523 } else {
2524 use->dump();
2525 assert(false, "should not be here");
2526 #endif
2527 }
2528 }
2529 }
2531 //
2532 // Search memory chain of "mem" to find a MemNode whose address
2533 // is the specified alias index.
2534 //
2535 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2536 if (orig_mem == NULL)
2537 return orig_mem;
2538 Compile* C = _compile;
2539 PhaseGVN* igvn = _igvn;
2540 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2541 bool is_instance = (toop != NULL) && toop->is_known_instance();
2542 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2543 Node *prev = NULL;
2544 Node *result = orig_mem;
2545 while (prev != result) {
2546 prev = result;
2547 if (result == start_mem)
2548 break; // hit one of our sentinels
2549 if (result->is_Mem()) {
2550 const Type *at = igvn->type(result->in(MemNode::Address));
2551 if (at == Type::TOP)
2552 break; // Dead
2553 assert (at->isa_ptr() != NULL, "pointer type required.");
2554 int idx = C->get_alias_index(at->is_ptr());
2555 if (idx == alias_idx)
2556 break; // Found
2557 if (!is_instance && (at->isa_oopptr() == NULL ||
2558 !at->is_oopptr()->is_known_instance())) {
2559 break; // Do not skip store to general memory slice.
2560 }
2561 result = result->in(MemNode::Memory);
2562 }
2563 if (!is_instance)
2564 continue; // don't search further for non-instance types
2565 // skip over a call which does not affect this memory slice
2566 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2567 Node *proj_in = result->in(0);
2568 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2569 break; // hit one of our sentinels
2570 } else if (proj_in->is_Call()) {
2571 CallNode *call = proj_in->as_Call();
2572 if (!call->may_modify(toop, igvn)) {
2573 result = call->in(TypeFunc::Memory);
2574 }
2575 } else if (proj_in->is_Initialize()) {
2576 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2577 // Stop if this is the initialization for the object instance which
2578 // which contains this memory slice, otherwise skip over it.
2579 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2580 result = proj_in->in(TypeFunc::Memory);
2581 }
2582 } else if (proj_in->is_MemBar()) {
2583 result = proj_in->in(TypeFunc::Memory);
2584 }
2585 } else if (result->is_MergeMem()) {
2586 MergeMemNode *mmem = result->as_MergeMem();
2587 result = step_through_mergemem(mmem, alias_idx, toop);
2588 if (result == mmem->base_memory()) {
2589 // Didn't find instance memory, search through general slice recursively.
2590 result = mmem->memory_at(C->get_general_index(alias_idx));
2591 result = find_inst_mem(result, alias_idx, orig_phis);
2592 if (C->failing()) {
2593 return NULL;
2594 }
2595 mmem->set_memory_at(alias_idx, result);
2596 }
2597 } else if (result->is_Phi() &&
2598 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2599 Node *un = result->as_Phi()->unique_input(igvn);
2600 if (un != NULL) {
2601 orig_phis.append_if_missing(result->as_Phi());
2602 result = un;
2603 } else {
2604 break;
2605 }
2606 } else if (result->is_ClearArray()) {
2607 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2608 // Can not bypass initialization of the instance
2609 // we are looking for.
2610 break;
2611 }
2612 // Otherwise skip it (the call updated 'result' value).
2613 } else if (result->Opcode() == Op_SCMemProj) {
2614 Node* mem = result->in(0);
2615 Node* adr = NULL;
2616 if (mem->is_LoadStore()) {
2617 adr = mem->in(MemNode::Address);
2618 } else {
2619 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2620 adr = mem->in(3); // Memory edge corresponds to destination array
2621 }
2622 const Type *at = igvn->type(adr);
2623 if (at != Type::TOP) {
2624 assert (at->isa_ptr() != NULL, "pointer type required.");
2625 int idx = C->get_alias_index(at->is_ptr());
2626 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2627 break;
2628 }
2629 result = mem->in(MemNode::Memory);
2630 }
2631 }
2632 if (result->is_Phi()) {
2633 PhiNode *mphi = result->as_Phi();
2634 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2635 const TypePtr *t = mphi->adr_type();
2636 if (!is_instance) {
2637 // Push all non-instance Phis on the orig_phis worklist to update inputs
2638 // during Phase 4 if needed.
2639 orig_phis.append_if_missing(mphi);
2640 } else if (C->get_alias_index(t) != alias_idx) {
2641 // Create a new Phi with the specified alias index type.
2642 result = split_memory_phi(mphi, alias_idx, orig_phis);
2643 }
2644 }
2645 // the result is either MemNode, PhiNode, InitializeNode.
2646 return result;
2647 }
2649 //
2650 // Convert the types of unescaped object to instance types where possible,
2651 // propagate the new type information through the graph, and update memory
2652 // edges and MergeMem inputs to reflect the new type.
2653 //
2654 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2655 // The processing is done in 4 phases:
2656 //
2657 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2658 // types for the CheckCastPP for allocations where possible.
2659 // Propagate the the new types through users as follows:
2660 // casts and Phi: push users on alloc_worklist
2661 // AddP: cast Base and Address inputs to the instance type
2662 // push any AddP users on alloc_worklist and push any memnode
2663 // users onto memnode_worklist.
2664 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2665 // search the Memory chain for a store with the appropriate type
2666 // address type. If a Phi is found, create a new version with
2667 // the appropriate memory slices from each of the Phi inputs.
2668 // For stores, process the users as follows:
2669 // MemNode: push on memnode_worklist
2670 // MergeMem: push on mergemem_worklist
2671 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2672 // moving the first node encountered of each instance type to the
2673 // the input corresponding to its alias index.
2674 // appropriate memory slice.
2675 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2676 //
2677 // In the following example, the CheckCastPP nodes are the cast of allocation
2678 // results and the allocation of node 29 is unescaped and eligible to be an
2679 // instance type.
2680 //
2681 // We start with:
2682 //
2683 // 7 Parm #memory
2684 // 10 ConI "12"
2685 // 19 CheckCastPP "Foo"
2686 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2687 // 29 CheckCastPP "Foo"
2688 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2689 //
2690 // 40 StoreP 25 7 20 ... alias_index=4
2691 // 50 StoreP 35 40 30 ... alias_index=4
2692 // 60 StoreP 45 50 20 ... alias_index=4
2693 // 70 LoadP _ 60 30 ... alias_index=4
2694 // 80 Phi 75 50 60 Memory alias_index=4
2695 // 90 LoadP _ 80 30 ... alias_index=4
2696 // 100 LoadP _ 80 20 ... alias_index=4
2697 //
2698 //
2699 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2700 // and creating a new alias index for node 30. This gives:
2701 //
2702 // 7 Parm #memory
2703 // 10 ConI "12"
2704 // 19 CheckCastPP "Foo"
2705 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2706 // 29 CheckCastPP "Foo" iid=24
2707 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2708 //
2709 // 40 StoreP 25 7 20 ... alias_index=4
2710 // 50 StoreP 35 40 30 ... alias_index=6
2711 // 60 StoreP 45 50 20 ... alias_index=4
2712 // 70 LoadP _ 60 30 ... alias_index=6
2713 // 80 Phi 75 50 60 Memory alias_index=4
2714 // 90 LoadP _ 80 30 ... alias_index=6
2715 // 100 LoadP _ 80 20 ... alias_index=4
2716 //
2717 // In phase 2, new memory inputs are computed for the loads and stores,
2718 // And a new version of the phi is created. In phase 4, the inputs to
2719 // node 80 are updated and then the memory nodes are updated with the
2720 // values computed in phase 2. This results in:
2721 //
2722 // 7 Parm #memory
2723 // 10 ConI "12"
2724 // 19 CheckCastPP "Foo"
2725 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2726 // 29 CheckCastPP "Foo" iid=24
2727 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2728 //
2729 // 40 StoreP 25 7 20 ... alias_index=4
2730 // 50 StoreP 35 7 30 ... alias_index=6
2731 // 60 StoreP 45 40 20 ... alias_index=4
2732 // 70 LoadP _ 50 30 ... alias_index=6
2733 // 80 Phi 75 40 60 Memory alias_index=4
2734 // 120 Phi 75 50 50 Memory alias_index=6
2735 // 90 LoadP _ 120 30 ... alias_index=6
2736 // 100 LoadP _ 80 20 ... alias_index=4
2737 //
2738 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2739 GrowableArray<Node *> memnode_worklist;
2740 GrowableArray<PhiNode *> orig_phis;
2741 PhaseIterGVN *igvn = _igvn;
2742 uint new_index_start = (uint) _compile->num_alias_types();
2743 Arena* arena = Thread::current()->resource_area();
2744 VectorSet visited(arena);
2745 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2746 uint unique_old = _compile->unique();
2748 // Phase 1: Process possible allocations from alloc_worklist.
2749 // Create instance types for the CheckCastPP for allocations where possible.
2750 //
2751 // (Note: don't forget to change the order of the second AddP node on
2752 // the alloc_worklist if the order of the worklist processing is changed,
2753 // see the comment in find_second_addp().)
2754 //
2755 while (alloc_worklist.length() != 0) {
2756 Node *n = alloc_worklist.pop();
2757 uint ni = n->_idx;
2758 if (n->is_Call()) {
2759 CallNode *alloc = n->as_Call();
2760 // copy escape information to call node
2761 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2762 PointsToNode::EscapeState es = ptn->escape_state();
2763 // We have an allocation or call which returns a Java object,
2764 // see if it is unescaped.
2765 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2766 continue;
2767 // Find CheckCastPP for the allocate or for the return value of a call
2768 n = alloc->result_cast();
2769 if (n == NULL) { // No uses except Initialize node
2770 if (alloc->is_Allocate()) {
2771 // Set the scalar_replaceable flag for allocation
2772 // so it could be eliminated if it has no uses.
2773 alloc->as_Allocate()->_is_scalar_replaceable = true;
2774 }
2775 if (alloc->is_CallStaticJava()) {
2776 // Set the scalar_replaceable flag for boxing method
2777 // so it could be eliminated if it has no uses.
2778 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2779 }
2780 continue;
2781 }
2782 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2783 assert(!alloc->is_Allocate(), "allocation should have unique type");
2784 continue;
2785 }
2787 // The inline code for Object.clone() casts the allocation result to
2788 // java.lang.Object and then to the actual type of the allocated
2789 // object. Detect this case and use the second cast.
2790 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2791 // the allocation result is cast to java.lang.Object and then
2792 // to the actual Array type.
2793 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2794 && (alloc->is_AllocateArray() ||
2795 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2796 Node *cast2 = NULL;
2797 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2798 Node *use = n->fast_out(i);
2799 if (use->is_CheckCastPP()) {
2800 cast2 = use;
2801 break;
2802 }
2803 }
2804 if (cast2 != NULL) {
2805 n = cast2;
2806 } else {
2807 // Non-scalar replaceable if the allocation type is unknown statically
2808 // (reflection allocation), the object can't be restored during
2809 // deoptimization without precise type.
2810 continue;
2811 }
2812 }
2813 if (alloc->is_Allocate()) {
2814 // Set the scalar_replaceable flag for allocation
2815 // so it could be eliminated.
2816 alloc->as_Allocate()->_is_scalar_replaceable = true;
2817 }
2818 if (alloc->is_CallStaticJava()) {
2819 // Set the scalar_replaceable flag for boxing method
2820 // so it could be eliminated.
2821 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2822 }
2823 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2824 // in order for an object to be scalar-replaceable, it must be:
2825 // - a direct allocation (not a call returning an object)
2826 // - non-escaping
2827 // - eligible to be a unique type
2828 // - not determined to be ineligible by escape analysis
2829 set_map(alloc, n);
2830 set_map(n, alloc);
2831 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2832 if (t == NULL)
2833 continue; // not a TypeOopPtr
2834 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2835 igvn->hash_delete(n);
2836 igvn->set_type(n, tinst);
2837 n->raise_bottom_type(tinst);
2838 igvn->hash_insert(n);
2839 record_for_optimizer(n);
2840 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2842 // First, put on the worklist all Field edges from Connection Graph
2843 // which is more accurate then putting immediate users from Ideal Graph.
2844 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2845 PointsToNode* tgt = e.get();
2846 Node* use = tgt->ideal_node();
2847 assert(tgt->is_Field() && use->is_AddP(),
2848 "only AddP nodes are Field edges in CG");
2849 if (use->outcnt() > 0) { // Don't process dead nodes
2850 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2851 if (addp2 != NULL) {
2852 assert(alloc->is_AllocateArray(),"array allocation was expected");
2853 alloc_worklist.append_if_missing(addp2);
2854 }
2855 alloc_worklist.append_if_missing(use);
2856 }
2857 }
2859 // An allocation may have an Initialize which has raw stores. Scan
2860 // the users of the raw allocation result and push AddP users
2861 // on alloc_worklist.
2862 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2863 assert (raw_result != NULL, "must have an allocation result");
2864 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2865 Node *use = raw_result->fast_out(i);
2866 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2867 Node* addp2 = find_second_addp(use, raw_result);
2868 if (addp2 != NULL) {
2869 assert(alloc->is_AllocateArray(),"array allocation was expected");
2870 alloc_worklist.append_if_missing(addp2);
2871 }
2872 alloc_worklist.append_if_missing(use);
2873 } else if (use->is_MemBar()) {
2874 memnode_worklist.append_if_missing(use);
2875 }
2876 }
2877 }
2878 } else if (n->is_AddP()) {
2879 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2880 if (jobj == NULL || jobj == phantom_obj) {
2881 #ifdef ASSERT
2882 ptnode_adr(get_addp_base(n)->_idx)->dump();
2883 ptnode_adr(n->_idx)->dump();
2884 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2885 #endif
2886 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2887 return;
2888 }
2889 Node *base = get_map(jobj->idx()); // CheckCastPP node
2890 if (!split_AddP(n, base)) continue; // wrong type from dead path
2891 } else if (n->is_Phi() ||
2892 n->is_CheckCastPP() ||
2893 n->is_EncodeP() ||
2894 n->is_DecodeN() ||
2895 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2896 if (visited.test_set(n->_idx)) {
2897 assert(n->is_Phi(), "loops only through Phi's");
2898 continue; // already processed
2899 }
2900 JavaObjectNode* jobj = unique_java_object(n);
2901 if (jobj == NULL || jobj == phantom_obj) {
2902 #ifdef ASSERT
2903 ptnode_adr(n->_idx)->dump();
2904 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2905 #endif
2906 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2907 return;
2908 } else {
2909 Node *val = get_map(jobj->idx()); // CheckCastPP node
2910 TypeNode *tn = n->as_Type();
2911 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2912 assert(tinst != NULL && tinst->is_known_instance() &&
2913 tinst->instance_id() == jobj->idx() , "instance type expected.");
2915 const Type *tn_type = igvn->type(tn);
2916 const TypeOopPtr *tn_t;
2917 if (tn_type->isa_narrowoop()) {
2918 tn_t = tn_type->make_ptr()->isa_oopptr();
2919 } else {
2920 tn_t = tn_type->isa_oopptr();
2921 }
2922 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2923 if (tn_type->isa_narrowoop()) {
2924 tn_type = tinst->make_narrowoop();
2925 } else {
2926 tn_type = tinst;
2927 }
2928 igvn->hash_delete(tn);
2929 igvn->set_type(tn, tn_type);
2930 tn->set_type(tn_type);
2931 igvn->hash_insert(tn);
2932 record_for_optimizer(n);
2933 } else {
2934 assert(tn_type == TypePtr::NULL_PTR ||
2935 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2936 "unexpected type");
2937 continue; // Skip dead path with different type
2938 }
2939 }
2940 } else {
2941 debug_only(n->dump();)
2942 assert(false, "EA: unexpected node");
2943 continue;
2944 }
2945 // push allocation's users on appropriate worklist
2946 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2947 Node *use = n->fast_out(i);
2948 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2949 // Load/store to instance's field
2950 memnode_worklist.append_if_missing(use);
2951 } else if (use->is_MemBar()) {
2952 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
2953 memnode_worklist.append_if_missing(use);
2954 }
2955 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2956 Node* addp2 = find_second_addp(use, n);
2957 if (addp2 != NULL) {
2958 alloc_worklist.append_if_missing(addp2);
2959 }
2960 alloc_worklist.append_if_missing(use);
2961 } else if (use->is_Phi() ||
2962 use->is_CheckCastPP() ||
2963 use->is_EncodeNarrowPtr() ||
2964 use->is_DecodeNarrowPtr() ||
2965 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2966 alloc_worklist.append_if_missing(use);
2967 #ifdef ASSERT
2968 } else if (use->is_Mem()) {
2969 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2970 } else if (use->is_MergeMem()) {
2971 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2972 } else if (use->is_SafePoint()) {
2973 // Look for MergeMem nodes for calls which reference unique allocation
2974 // (through CheckCastPP nodes) even for debug info.
2975 Node* m = use->in(TypeFunc::Memory);
2976 if (m->is_MergeMem()) {
2977 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2978 }
2979 } else if (use->Opcode() == Op_EncodeISOArray) {
2980 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
2981 // EncodeISOArray overwrites destination array
2982 memnode_worklist.append_if_missing(use);
2983 }
2984 } else {
2985 uint op = use->Opcode();
2986 if (!(op == Op_CmpP || op == Op_Conv2B ||
2987 op == Op_CastP2X || op == Op_StoreCM ||
2988 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
2989 op == Op_StrEquals || op == Op_StrIndexOf)) {
2990 n->dump();
2991 use->dump();
2992 assert(false, "EA: missing allocation reference path");
2993 }
2994 #endif
2995 }
2996 }
2998 }
2999 // New alias types were created in split_AddP().
3000 uint new_index_end = (uint) _compile->num_alias_types();
3001 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3003 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3004 // compute new values for Memory inputs (the Memory inputs are not
3005 // actually updated until phase 4.)
3006 if (memnode_worklist.length() == 0)
3007 return; // nothing to do
3008 while (memnode_worklist.length() != 0) {
3009 Node *n = memnode_worklist.pop();
3010 if (visited.test_set(n->_idx))
3011 continue;
3012 if (n->is_Phi() || n->is_ClearArray()) {
3013 // we don't need to do anything, but the users must be pushed
3014 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3015 // we don't need to do anything, but the users must be pushed
3016 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3017 if (n == NULL)
3018 continue;
3019 } else if (n->Opcode() == Op_EncodeISOArray) {
3020 // get the memory projection
3021 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3022 Node *use = n->fast_out(i);
3023 if (use->Opcode() == Op_SCMemProj) {
3024 n = use;
3025 break;
3026 }
3027 }
3028 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3029 } else {
3030 assert(n->is_Mem(), "memory node required.");
3031 Node *addr = n->in(MemNode::Address);
3032 const Type *addr_t = igvn->type(addr);
3033 if (addr_t == Type::TOP)
3034 continue;
3035 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3036 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3037 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3038 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3039 if (_compile->failing()) {
3040 return;
3041 }
3042 if (mem != n->in(MemNode::Memory)) {
3043 // We delay the memory edge update since we need old one in
3044 // MergeMem code below when instances memory slices are separated.
3045 set_map(n, mem);
3046 }
3047 if (n->is_Load()) {
3048 continue; // don't push users
3049 } else if (n->is_LoadStore()) {
3050 // get the memory projection
3051 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3052 Node *use = n->fast_out(i);
3053 if (use->Opcode() == Op_SCMemProj) {
3054 n = use;
3055 break;
3056 }
3057 }
3058 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3059 }
3060 }
3061 // push user on appropriate worklist
3062 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3063 Node *use = n->fast_out(i);
3064 if (use->is_Phi() || use->is_ClearArray()) {
3065 memnode_worklist.append_if_missing(use);
3066 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3067 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3068 continue;
3069 memnode_worklist.append_if_missing(use);
3070 } else if (use->is_MemBar()) {
3071 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3072 memnode_worklist.append_if_missing(use);
3073 }
3074 #ifdef ASSERT
3075 } else if(use->is_Mem()) {
3076 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3077 } else if (use->is_MergeMem()) {
3078 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3079 } else if (use->Opcode() == Op_EncodeISOArray) {
3080 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3081 // EncodeISOArray overwrites destination array
3082 memnode_worklist.append_if_missing(use);
3083 }
3084 } else {
3085 uint op = use->Opcode();
3086 if (!(op == Op_StoreCM ||
3087 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3088 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3089 op == Op_AryEq || op == Op_StrComp ||
3090 op == Op_StrEquals || op == Op_StrIndexOf)) {
3091 n->dump();
3092 use->dump();
3093 assert(false, "EA: missing memory path");
3094 }
3095 #endif
3096 }
3097 }
3098 }
3100 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3101 // Walk each memory slice moving the first node encountered of each
3102 // instance type to the the input corresponding to its alias index.
3103 uint length = _mergemem_worklist.length();
3104 for( uint next = 0; next < length; ++next ) {
3105 MergeMemNode* nmm = _mergemem_worklist.at(next);
3106 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3107 // Note: we don't want to use MergeMemStream here because we only want to
3108 // scan inputs which exist at the start, not ones we add during processing.
3109 // Note 2: MergeMem may already contains instance memory slices added
3110 // during find_inst_mem() call when memory nodes were processed above.
3111 igvn->hash_delete(nmm);
3112 uint nslices = nmm->req();
3113 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3114 Node* mem = nmm->in(i);
3115 Node* cur = NULL;
3116 if (mem == NULL || mem->is_top())
3117 continue;
3118 // First, update mergemem by moving memory nodes to corresponding slices
3119 // if their type became more precise since this mergemem was created.
3120 while (mem->is_Mem()) {
3121 const Type *at = igvn->type(mem->in(MemNode::Address));
3122 if (at != Type::TOP) {
3123 assert (at->isa_ptr() != NULL, "pointer type required.");
3124 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3125 if (idx == i) {
3126 if (cur == NULL)
3127 cur = mem;
3128 } else {
3129 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3130 nmm->set_memory_at(idx, mem);
3131 }
3132 }
3133 }
3134 mem = mem->in(MemNode::Memory);
3135 }
3136 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3137 // Find any instance of the current type if we haven't encountered
3138 // already a memory slice of the instance along the memory chain.
3139 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3140 if((uint)_compile->get_general_index(ni) == i) {
3141 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3142 if (nmm->is_empty_memory(m)) {
3143 Node* result = find_inst_mem(mem, ni, orig_phis);
3144 if (_compile->failing()) {
3145 return;
3146 }
3147 nmm->set_memory_at(ni, result);
3148 }
3149 }
3150 }
3151 }
3152 // Find the rest of instances values
3153 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3154 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3155 Node* result = step_through_mergemem(nmm, ni, tinst);
3156 if (result == nmm->base_memory()) {
3157 // Didn't find instance memory, search through general slice recursively.
3158 result = nmm->memory_at(_compile->get_general_index(ni));
3159 result = find_inst_mem(result, ni, orig_phis);
3160 if (_compile->failing()) {
3161 return;
3162 }
3163 nmm->set_memory_at(ni, result);
3164 }
3165 }
3166 igvn->hash_insert(nmm);
3167 record_for_optimizer(nmm);
3168 }
3170 // Phase 4: Update the inputs of non-instance memory Phis and
3171 // the Memory input of memnodes
3172 // First update the inputs of any non-instance Phi's from
3173 // which we split out an instance Phi. Note we don't have
3174 // to recursively process Phi's encounted on the input memory
3175 // chains as is done in split_memory_phi() since they will
3176 // also be processed here.
3177 for (int j = 0; j < orig_phis.length(); j++) {
3178 PhiNode *phi = orig_phis.at(j);
3179 int alias_idx = _compile->get_alias_index(phi->adr_type());
3180 igvn->hash_delete(phi);
3181 for (uint i = 1; i < phi->req(); i++) {
3182 Node *mem = phi->in(i);
3183 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3184 if (_compile->failing()) {
3185 return;
3186 }
3187 if (mem != new_mem) {
3188 phi->set_req(i, new_mem);
3189 }
3190 }
3191 igvn->hash_insert(phi);
3192 record_for_optimizer(phi);
3193 }
3195 // Update the memory inputs of MemNodes with the value we computed
3196 // in Phase 2 and move stores memory users to corresponding memory slices.
3197 // Disable memory split verification code until the fix for 6984348.
3198 // Currently it produces false negative results since it does not cover all cases.
3199 #if 0 // ifdef ASSERT
3200 visited.Reset();
3201 Node_Stack old_mems(arena, _compile->unique() >> 2);
3202 #endif
3203 for (uint i = 0; i < ideal_nodes.size(); i++) {
3204 Node* n = ideal_nodes.at(i);
3205 Node* nmem = get_map(n->_idx);
3206 assert(nmem != NULL, "sanity");
3207 if (n->is_Mem()) {
3208 #if 0 // ifdef ASSERT
3209 Node* old_mem = n->in(MemNode::Memory);
3210 if (!visited.test_set(old_mem->_idx)) {
3211 old_mems.push(old_mem, old_mem->outcnt());
3212 }
3213 #endif
3214 assert(n->in(MemNode::Memory) != nmem, "sanity");
3215 if (!n->is_Load()) {
3216 // Move memory users of a store first.
3217 move_inst_mem(n, orig_phis);
3218 }
3219 // Now update memory input
3220 igvn->hash_delete(n);
3221 n->set_req(MemNode::Memory, nmem);
3222 igvn->hash_insert(n);
3223 record_for_optimizer(n);
3224 } else {
3225 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3226 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3227 }
3228 }
3229 #if 0 // ifdef ASSERT
3230 // Verify that memory was split correctly
3231 while (old_mems.is_nonempty()) {
3232 Node* old_mem = old_mems.node();
3233 uint old_cnt = old_mems.index();
3234 old_mems.pop();
3235 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3236 }
3237 #endif
3238 }
3240 #ifndef PRODUCT
3241 static const char *node_type_names[] = {
3242 "UnknownType",
3243 "JavaObject",
3244 "LocalVar",
3245 "Field",
3246 "Arraycopy"
3247 };
3249 static const char *esc_names[] = {
3250 "UnknownEscape",
3251 "NoEscape",
3252 "ArgEscape",
3253 "GlobalEscape"
3254 };
3256 void PointsToNode::dump(bool print_state) const {
3257 NodeType nt = node_type();
3258 tty->print("%s ", node_type_names[(int) nt]);
3259 if (print_state) {
3260 EscapeState es = escape_state();
3261 EscapeState fields_es = fields_escape_state();
3262 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3263 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3264 tty->print("NSR ");
3265 }
3266 if (is_Field()) {
3267 FieldNode* f = (FieldNode*)this;
3268 if (f->is_oop())
3269 tty->print("oop ");
3270 if (f->offset() > 0)
3271 tty->print("+%d ", f->offset());
3272 tty->print("(");
3273 for (BaseIterator i(f); i.has_next(); i.next()) {
3274 PointsToNode* b = i.get();
3275 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3276 }
3277 tty->print(" )");
3278 }
3279 tty->print("[");
3280 for (EdgeIterator i(this); i.has_next(); i.next()) {
3281 PointsToNode* e = i.get();
3282 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3283 }
3284 tty->print(" [");
3285 for (UseIterator i(this); i.has_next(); i.next()) {
3286 PointsToNode* u = i.get();
3287 bool is_base = false;
3288 if (PointsToNode::is_base_use(u)) {
3289 is_base = true;
3290 u = PointsToNode::get_use_node(u)->as_Field();
3291 }
3292 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3293 }
3294 tty->print(" ]] ");
3295 if (_node == NULL)
3296 tty->print_cr("<null>");
3297 else
3298 _node->dump();
3299 }
3301 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3302 bool first = true;
3303 int ptnodes_length = ptnodes_worklist.length();
3304 for (int i = 0; i < ptnodes_length; i++) {
3305 PointsToNode *ptn = ptnodes_worklist.at(i);
3306 if (ptn == NULL || !ptn->is_JavaObject())
3307 continue;
3308 PointsToNode::EscapeState es = ptn->escape_state();
3309 if ((es != PointsToNode::NoEscape) && !Verbose) {
3310 continue;
3311 }
3312 Node* n = ptn->ideal_node();
3313 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3314 n->as_CallStaticJava()->is_boxing_method())) {
3315 if (first) {
3316 tty->cr();
3317 tty->print("======== Connection graph for ");
3318 _compile->method()->print_short_name();
3319 tty->cr();
3320 first = false;
3321 }
3322 ptn->dump();
3323 // Print all locals and fields which reference this allocation
3324 for (UseIterator j(ptn); j.has_next(); j.next()) {
3325 PointsToNode* use = j.get();
3326 if (use->is_LocalVar()) {
3327 use->dump(Verbose);
3328 } else if (Verbose) {
3329 use->dump();
3330 }
3331 }
3332 tty->cr();
3333 }
3334 }
3335 }
3336 #endif