1 /*
2 * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "opto/c2compiler.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/compile.hpp"
34 #include "opto/escape.hpp"
35 #include "opto/phaseX.hpp"
36 #include "opto/rootnode.hpp"
37
38 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
39 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
40 _collecting(true),
41 _verify(false),
42 _compile(C),
43 _igvn(igvn),
44 _node_map(C->comp_arena()) {
45 // Add unknown java object.
46 add_java_object(C->top(), PointsToNode::GlobalEscape);
47 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
48 // Add ConP(#NULL) and ConN(#NULL) nodes.
49 Node* oop_null = igvn->zerocon(T_OBJECT);
50 assert(oop_null->_idx < nodes_size(), "should be created already");
51 add_java_object(oop_null, PointsToNode::NoEscape);
52 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
53 if (UseCompressedOops) {
54 Node* noop_null = igvn->zerocon(T_NARROWOOP);
55 assert(noop_null->_idx < nodes_size(), "should be created already");
56 map_ideal_node(noop_null, null_obj);
57 }
58 _pcmp_neq = NULL; // Should be initialized
59 _pcmp_eq = NULL;
60 }
61
62 bool ConnectionGraph::has_candidates(Compile *C) {
63 // EA brings benefits only when the code has allocations and/or locks which
64 // are represented by ideal Macro nodes.
65 int cnt = C->macro_count();
66 for( int i=0; i < cnt; i++ ) {
67 Node *n = C->macro_node(i);
68 if ( n->is_Allocate() )
69 return true;
70 if( n->is_Lock() ) {
71 Node* obj = n->as_Lock()->obj_node()->uncast();
72 if( !(obj->is_Parm() || obj->is_Con()) )
73 return true;
74 }
75 }
76 return false;
77 }
78
79 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
80 Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
81 ResourceMark rm;
82
83 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
84 // to create space for them in ConnectionGraph::_nodes[].
85 Node* oop_null = igvn->zerocon(T_OBJECT);
86 Node* noop_null = igvn->zerocon(T_NARROWOOP);
87 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
88 // Perform escape analysis
89 if (congraph->compute_escape()) {
90 // There are non escaping objects.
91 C->set_congraph(congraph);
92 }
93 // Cleanup.
94 if (oop_null->outcnt() == 0)
95 igvn->hash_delete(oop_null);
96 if (noop_null->outcnt() == 0)
97 igvn->hash_delete(noop_null);
98 }
99
100 bool ConnectionGraph::compute_escape() {
101 Compile* C = _compile;
102 PhaseGVN* igvn = _igvn;
103
104 // Worklists used by EA.
105 Unique_Node_List delayed_worklist;
106 GrowableArray<Node*> alloc_worklist;
107 GrowableArray<Node*> ptr_cmp_worklist;
108 GrowableArray<Node*> storestore_worklist;
109 GrowableArray<PointsToNode*> ptnodes_worklist;
110 GrowableArray<JavaObjectNode*> java_objects_worklist;
111 GrowableArray<JavaObjectNode*> non_escaped_worklist;
112 GrowableArray<FieldNode*> oop_fields_worklist;
113 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
114
115 { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
116
117 // 1. Populate Connection Graph (CG) with PointsTo nodes.
118 ideal_nodes.map(C->unique(), NULL); // preallocate space
119 // Initialize worklist
120 if (C->root() != NULL) {
121 ideal_nodes.push(C->root());
122 }
123 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
124 Node* n = ideal_nodes.at(next);
125 // Create PointsTo nodes and add them to Connection Graph. Called
126 // only once per ideal node since ideal_nodes is Unique_Node list.
127 add_node_to_connection_graph(n, &delayed_worklist);
128 PointsToNode* ptn = ptnode_adr(n->_idx);
129 if (ptn != NULL) {
130 ptnodes_worklist.append(ptn);
131 if (ptn->is_JavaObject()) {
132 java_objects_worklist.append(ptn->as_JavaObject());
133 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
134 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
135 // Only allocations and java static calls results are interesting.
136 non_escaped_worklist.append(ptn->as_JavaObject());
137 }
138 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
139 oop_fields_worklist.append(ptn->as_Field());
140 }
141 }
142 if (n->is_MergeMem()) {
143 // Collect all MergeMem nodes to add memory slices for
144 // scalar replaceable objects in split_unique_types().
145 _mergemem_worklist.append(n->as_MergeMem());
146 } else if (OptimizePtrCompare && n->is_Cmp() &&
147 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
148 // Collect compare pointers nodes.
149 ptr_cmp_worklist.append(n);
150 } else if (n->is_MemBarStoreStore()) {
151 // Collect all MemBarStoreStore nodes so that depending on the
152 // escape status of the associated Allocate node some of them
153 // may be eliminated.
154 storestore_worklist.append(n);
155 #ifdef ASSERT
156 } else if(n->is_AddP()) {
157 // Collect address nodes for graph verification.
158 addp_worklist.append(n);
159 #endif
160 }
161 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
162 Node* m = n->fast_out(i); // Get user
163 ideal_nodes.push(m);
164 }
165 }
166 if (non_escaped_worklist.length() == 0) {
167 _collecting = false;
168 return false; // Nothing to do.
169 }
170 // Add final simple edges to graph.
171 while(delayed_worklist.size() > 0) {
172 Node* n = delayed_worklist.pop();
173 add_final_edges(n);
174 }
175 int ptnodes_length = ptnodes_worklist.length();
176
177 #ifdef ASSERT
178 if (VerifyConnectionGraph) {
179 // Verify that no new simple edges could be created and all
180 // local vars has edges.
181 _verify = true;
182 for (int next = 0; next < ptnodes_length; ++next) {
183 PointsToNode* ptn = ptnodes_worklist.at(next);
184 add_final_edges(ptn->ideal_node());
185 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
186 ptn->dump();
187 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
188 }
189 }
190 _verify = false;
191 }
192 #endif
193
194 // 2. Finish Graph construction by propagating references to all
195 // java objects through graph.
196 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
197 java_objects_worklist, oop_fields_worklist)) {
198 // All objects escaped or hit time or iterations limits.
199 _collecting = false;
200 return false;
201 }
202
203 // 3. Adjust scalar_replaceable state of nonescaping objects and push
204 // scalar replaceable allocations on alloc_worklist for processing
205 // in split_unique_types().
206 int non_escaped_length = non_escaped_worklist.length();
207 for (int next = 0; next < non_escaped_length; next++) {
208 JavaObjectNode* ptn = non_escaped_worklist.at(next);
209 if (ptn->escape_state() == PointsToNode::NoEscape &&
210 ptn->scalar_replaceable()) {
211 adjust_scalar_replaceable_state(ptn);
212 if (ptn->scalar_replaceable()) {
213 alloc_worklist.append(ptn->ideal_node());
214 }
215 }
216 }
217
218 #ifdef ASSERT
219 if (VerifyConnectionGraph) {
220 // Verify that graph is complete - no new edges could be added or needed.
221 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
222 java_objects_worklist, addp_worklist);
223 }
224 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
225 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
226 null_obj->edge_count() == 0 &&
227 !null_obj->arraycopy_src() &&
228 !null_obj->arraycopy_dst(), "sanity");
229 #endif
230
231 _collecting = false;
232
233 } // TracePhase t3("connectionGraph")
234
235 // 4. Optimize ideal graph based on EA information.
236 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
237 if (has_non_escaping_obj) {
238 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
239 }
240
241 #ifndef PRODUCT
242 if (PrintEscapeAnalysis) {
243 dump(ptnodes_worklist); // Dump ConnectionGraph
244 }
245 #endif
246
247 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
248 #ifdef ASSERT
249 if (VerifyConnectionGraph) {
250 int alloc_length = alloc_worklist.length();
251 for (int next = 0; next < alloc_length; ++next) {
252 Node* n = alloc_worklist.at(next);
253 PointsToNode* ptn = ptnode_adr(n->_idx);
254 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
255 }
256 }
257 #endif
258
259 // 5. Separate memory graph for scalar replaceable allcations.
260 if (has_scalar_replaceable_candidates &&
261 C->AliasLevel() >= 3 && EliminateAllocations) {
262 // Now use the escape information to create unique types for
263 // scalar replaceable objects.
264 split_unique_types(alloc_worklist);
265 if (C->failing()) return false;
266 C->print_method("After Escape Analysis", 2);
267
268 #ifdef ASSERT
269 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
270 tty->print("=== No allocations eliminated for ");
271 C->method()->print_short_name();
272 if(!EliminateAllocations) {
273 tty->print(" since EliminateAllocations is off ===");
274 } else if(!has_scalar_replaceable_candidates) {
275 tty->print(" since there are no scalar replaceable candidates ===");
276 } else if(C->AliasLevel() < 3) {
277 tty->print(" since AliasLevel < 3 ===");
278 }
279 tty->cr();
280 #endif
281 }
282 return has_non_escaping_obj;
283 }
284
285 // Populate Connection Graph with PointsTo nodes and create simple
286 // connection graph edges.
287 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
288 assert(!_verify, "this method sould not be called for verification");
289 PhaseGVN* igvn = _igvn;
290 uint n_idx = n->_idx;
291 PointsToNode* n_ptn = ptnode_adr(n_idx);
292 if (n_ptn != NULL)
293 return; // No need to redefine PointsTo node during first iteration.
294
295 if (n->is_Call()) {
296 // Arguments to allocation and locking don't escape.
297 if (n->is_AbstractLock()) {
298 // Put Lock and Unlock nodes on IGVN worklist to process them during
299 // first IGVN optimization when escape information is still available.
300 record_for_optimizer(n);
301 } else if (n->is_Allocate()) {
302 add_call_node(n->as_Call());
303 record_for_optimizer(n);
304 } else {
305 if (n->is_CallStaticJava()) {
306 const char* name = n->as_CallStaticJava()->_name;
307 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
308 return; // Skip uncommon traps
309 }
310 // Don't mark as processed since call's arguments have to be processed.
311 delayed_worklist->push(n);
312 // Check if a call returns an object.
313 if (n->as_Call()->returns_pointer() &&
314 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
315 add_call_node(n->as_Call());
316 }
317 }
318 return;
319 }
320 // Put this check here to process call arguments since some call nodes
321 // point to phantom_obj.
322 if (n_ptn == phantom_obj || n_ptn == null_obj)
323 return; // Skip predefined nodes.
324
325 int opcode = n->Opcode();
326 switch (opcode) {
327 case Op_AddP: {
328 Node* base = get_addp_base(n);
329 PointsToNode* ptn_base = ptnode_adr(base->_idx);
330 // Field nodes are created for all field types. They are used in
331 // adjust_scalar_replaceable_state() and split_unique_types().
332 // Note, non-oop fields will have only base edges in Connection
333 // Graph because such fields are not used for oop loads and stores.
334 int offset = address_offset(n, igvn);
335 add_field(n, PointsToNode::NoEscape, offset);
336 if (ptn_base == NULL) {
337 delayed_worklist->push(n); // Process it later.
338 } else {
339 n_ptn = ptnode_adr(n_idx);
340 add_base(n_ptn->as_Field(), ptn_base);
341 }
342 break;
343 }
344 case Op_CastX2P: {
345 map_ideal_node(n, phantom_obj);
346 break;
347 }
348 case Op_CastPP:
349 case Op_CheckCastPP:
350 case Op_EncodeP:
351 case Op_DecodeN: {
352 add_local_var_and_edge(n, PointsToNode::NoEscape,
353 n->in(1), delayed_worklist);
354 break;
355 }
356 case Op_CMoveP: {
357 add_local_var(n, PointsToNode::NoEscape);
358 // Do not add edges during first iteration because some could be
359 // not defined yet.
360 delayed_worklist->push(n);
361 break;
362 }
363 case Op_ConP:
364 case Op_ConN: {
365 // assume all oop constants globally escape except for null
366 PointsToNode::EscapeState es;
367 if (igvn->type(n) == TypePtr::NULL_PTR ||
368 igvn->type(n) == TypeNarrowOop::NULL_PTR) {
369 es = PointsToNode::NoEscape;
370 } else {
371 es = PointsToNode::GlobalEscape;
372 }
373 add_java_object(n, es);
374 break;
375 }
376 case Op_CreateEx: {
377 // assume that all exception objects globally escape
378 add_java_object(n, PointsToNode::GlobalEscape);
379 break;
380 }
381 case Op_LoadKlass:
382 case Op_LoadNKlass: {
383 // Unknown class is loaded
384 map_ideal_node(n, phantom_obj);
385 break;
386 }
387 case Op_LoadP:
388 case Op_LoadN:
389 case Op_LoadPLocked: {
390 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
391 // ThreadLocal has RawPrt type.
392 const Type* t = igvn->type(n);
393 if (t->make_ptr() != NULL) {
394 Node* adr = n->in(MemNode::Address);
395 #ifdef ASSERT
396 if (!adr->is_AddP()) {
397 assert(igvn->type(adr)->isa_rawptr(), "sanity");
398 } else {
399 assert((ptnode_adr(adr->_idx) == NULL ||
400 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
401 }
402 #endif
403 add_local_var_and_edge(n, PointsToNode::NoEscape,
404 adr, delayed_worklist);
405 }
406 break;
407 }
408 case Op_Parm: {
409 map_ideal_node(n, phantom_obj);
410 break;
411 }
412 case Op_PartialSubtypeCheck: {
413 // Produces Null or notNull and is used in only in CmpP so
414 // phantom_obj could be used.
415 map_ideal_node(n, phantom_obj); // Result is unknown
416 break;
417 }
418 case Op_Phi: {
419 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
420 // ThreadLocal has RawPrt type.
421 const Type* t = n->as_Phi()->type();
422 if (t->make_ptr() != NULL) {
423 add_local_var(n, PointsToNode::NoEscape);
424 // Do not add edges during first iteration because some could be
425 // not defined yet.
426 delayed_worklist->push(n);
427 }
428 break;
429 }
430 case Op_Proj: {
431 // we are only interested in the oop result projection from a call
432 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
433 n->in(0)->as_Call()->returns_pointer()) {
434 add_local_var_and_edge(n, PointsToNode::NoEscape,
435 n->in(0), delayed_worklist);
436 }
437 break;
438 }
439 case Op_Rethrow: // Exception object escapes
440 case Op_Return: {
441 if (n->req() > TypeFunc::Parms &&
442 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
443 // Treat Return value as LocalVar with GlobalEscape escape state.
444 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
445 n->in(TypeFunc::Parms), delayed_worklist);
446 }
447 break;
448 }
449 case Op_StoreP:
450 case Op_StoreN:
451 case Op_StorePConditional:
452 case Op_CompareAndSwapP:
453 case Op_CompareAndSwapN: {
454 Node* adr = n->in(MemNode::Address);
455 const Type *adr_type = igvn->type(adr);
456 adr_type = adr_type->make_ptr();
457 if (adr_type->isa_oopptr() ||
458 (opcode == Op_StoreP || opcode == Op_StoreN) &&
459 (adr_type == TypeRawPtr::NOTNULL &&
460 adr->in(AddPNode::Address)->is_Proj() &&
461 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
462 delayed_worklist->push(n); // Process it later.
463 #ifdef ASSERT
464 assert(adr->is_AddP(), "expecting an AddP");
465 if (adr_type == TypeRawPtr::NOTNULL) {
466 // Verify a raw address for a store captured by Initialize node.
467 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
468 assert(offs != Type::OffsetBot, "offset must be a constant");
469 }
470 #endif
471 } else {
472 // Ignore copy the displaced header to the BoxNode (OSR compilation).
473 if (adr->is_BoxLock())
474 break;
475 // Stored value escapes in unsafe access.
476 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
477 // Pointer stores in G1 barriers looks like unsafe access.
478 // Ignore such stores to be able scalar replace non-escaping
479 // allocations.
480 if (UseG1GC && adr->is_AddP()) {
481 Node* base = get_addp_base(adr);
482 if (base->Opcode() == Op_LoadP &&
483 base->in(MemNode::Address)->is_AddP()) {
484 adr = base->in(MemNode::Address);
485 Node* tls = get_addp_base(adr);
486 if (tls->Opcode() == Op_ThreadLocal) {
487 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
488 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
489 PtrQueue::byte_offset_of_buf())) {
490 break; // G1 pre barier previous oop value store.
491 }
492 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
493 PtrQueue::byte_offset_of_buf())) {
494 break; // G1 post barier card address store.
495 }
496 }
497 }
498 }
499 delayed_worklist->push(n); // Process unsafe access later.
500 break;
501 }
502 #ifdef ASSERT
503 n->dump(1);
504 assert(false, "not unsafe or G1 barrier raw StoreP");
505 #endif
506 }
507 break;
508 }
509 case Op_AryEq:
510 case Op_StrComp:
511 case Op_StrEquals:
512 case Op_StrIndexOf: {
513 add_local_var(n, PointsToNode::ArgEscape);
514 delayed_worklist->push(n); // Process it later.
515 break;
516 }
517 case Op_ThreadLocal: {
518 add_java_object(n, PointsToNode::ArgEscape);
519 break;
520 }
521 default:
522 ; // Do nothing for nodes not related to EA.
523 }
524 return;
525 }
526
527 #ifdef ASSERT
528 #define ELSE_FAIL(name) \
529 /* Should not be called for not pointer type. */ \
530 n->dump(1); \
531 assert(false, name); \
532 break;
533 #else
534 #define ELSE_FAIL(name) \
535 break;
536 #endif
537
538 // Add final simple edges to graph.
539 void ConnectionGraph::add_final_edges(Node *n) {
540 PointsToNode* n_ptn = ptnode_adr(n->_idx);
541 #ifdef ASSERT
542 if (_verify && n_ptn->is_JavaObject())
543 return; // This method does not change graph for JavaObject.
544 #endif
545
546 if (n->is_Call()) {
547 process_call_arguments(n->as_Call());
548 return;
549 }
550 assert(n->is_Store() || n->is_LoadStore() ||
551 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
552 "node should be registered already");
553 int opcode = n->Opcode();
554 switch (opcode) {
555 case Op_AddP: {
556 Node* base = get_addp_base(n);
557 PointsToNode* ptn_base = ptnode_adr(base->_idx);
558 assert(ptn_base != NULL, "field's base should be registered");
559 add_base(n_ptn->as_Field(), ptn_base);
560 break;
561 }
562 case Op_CastPP:
563 case Op_CheckCastPP:
564 case Op_EncodeP:
565 case Op_DecodeN: {
566 add_local_var_and_edge(n, PointsToNode::NoEscape,
567 n->in(1), NULL);
568 break;
569 }
570 case Op_CMoveP: {
571 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
572 Node* in = n->in(i);
573 if (in == NULL)
574 continue; // ignore NULL
575 Node* uncast_in = in->uncast();
576 if (uncast_in->is_top() || uncast_in == n)
577 continue; // ignore top or inputs which go back this node
578 PointsToNode* ptn = ptnode_adr(in->_idx);
579 assert(ptn != NULL, "node should be registered");
580 add_edge(n_ptn, ptn);
581 }
582 break;
583 }
584 case Op_LoadP:
585 case Op_LoadN:
586 case Op_LoadPLocked: {
587 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
588 // ThreadLocal has RawPrt type.
589 const Type* t = _igvn->type(n);
590 if (t->make_ptr() != NULL) {
591 Node* adr = n->in(MemNode::Address);
592 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
593 break;
594 }
595 ELSE_FAIL("Op_LoadP");
596 }
597 case Op_Phi: {
598 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
599 // ThreadLocal has RawPrt type.
600 const Type* t = n->as_Phi()->type();
601 if (t->make_ptr() != NULL) {
602 for (uint i = 1; i < n->req(); i++) {
603 Node* in = n->in(i);
604 if (in == NULL)
605 continue; // ignore NULL
606 Node* uncast_in = in->uncast();
607 if (uncast_in->is_top() || uncast_in == n)
608 continue; // ignore top or inputs which go back this node
609 PointsToNode* ptn = ptnode_adr(in->_idx);
610 assert(ptn != NULL, "node should be registered");
611 add_edge(n_ptn, ptn);
612 }
613 break;
614 }
615 ELSE_FAIL("Op_Phi");
616 }
617 case Op_Proj: {
618 // we are only interested in the oop result projection from a call
619 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
620 n->in(0)->as_Call()->returns_pointer()) {
621 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
622 break;
623 }
624 ELSE_FAIL("Op_Proj");
625 }
626 case Op_Rethrow: // Exception object escapes
627 case Op_Return: {
628 if (n->req() > TypeFunc::Parms &&
629 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
630 // Treat Return value as LocalVar with GlobalEscape escape state.
631 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
632 n->in(TypeFunc::Parms), NULL);
633 break;
634 }
635 ELSE_FAIL("Op_Return");
636 }
637 case Op_StoreP:
638 case Op_StoreN:
639 case Op_StorePConditional:
640 case Op_CompareAndSwapP:
641 case Op_CompareAndSwapN: {
642 Node* adr = n->in(MemNode::Address);
643 const Type *adr_type = _igvn->type(adr);
644 adr_type = adr_type->make_ptr();
645 if (adr_type->isa_oopptr() ||
646 (opcode == Op_StoreP || opcode == Op_StoreN) &&
647 (adr_type == TypeRawPtr::NOTNULL &&
648 adr->in(AddPNode::Address)->is_Proj() &&
649 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
650 // Point Address to Value
651 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
652 assert(adr_ptn != NULL &&
653 adr_ptn->as_Field()->is_oop(), "node should be registered");
654 Node *val = n->in(MemNode::ValueIn);
655 PointsToNode* ptn = ptnode_adr(val->_idx);
656 assert(ptn != NULL, "node should be registered");
657 add_edge(adr_ptn, ptn);
658 break;
659 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
660 // Stored value escapes in unsafe access.
661 Node *val = n->in(MemNode::ValueIn);
662 PointsToNode* ptn = ptnode_adr(val->_idx);
663 assert(ptn != NULL, "node should be registered");
664 ptn->set_escape_state(PointsToNode::GlobalEscape);
665 // Add edge to object for unsafe access with offset.
666 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
667 assert(adr_ptn != NULL, "node should be registered");
668 if (adr_ptn->is_Field()) {
669 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
670 add_edge(adr_ptn, ptn);
671 }
672 break;
673 }
674 ELSE_FAIL("Op_StoreP");
675 }
676 case Op_AryEq:
677 case Op_StrComp:
678 case Op_StrEquals:
679 case Op_StrIndexOf: {
680 // char[] arrays passed to string intrinsic do not escape but
681 // they are not scalar replaceable. Adjust escape state for them.
682 // Start from in(2) edge since in(1) is memory edge.
683 for (uint i = 2; i < n->req(); i++) {
684 Node* adr = n->in(i);
685 const Type* at = _igvn->type(adr);
686 if (!adr->is_top() && at->isa_ptr()) {
687 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
688 at->isa_ptr() != NULL, "expecting a pointer");
689 if (adr->is_AddP()) {
690 adr = get_addp_base(adr);
691 }
692 PointsToNode* ptn = ptnode_adr(adr->_idx);
693 assert(ptn != NULL, "node should be registered");
694 add_edge(n_ptn, ptn);
695 }
696 }
697 break;
698 }
699 default: {
700 // This method should be called only for EA specific nodes which may
701 // miss some edges when they were created.
702 #ifdef ASSERT
703 n->dump(1);
704 #endif
705 guarantee(false, "unknown node");
706 }
707 }
708 return;
709 }
710
711 void ConnectionGraph::add_call_node(CallNode* call) {
712 assert(call->returns_pointer(), "only for call which returns pointer");
713 uint call_idx = call->_idx;
714 if (call->is_Allocate()) {
715 Node* k = call->in(AllocateNode::KlassNode);
716 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
717 assert(kt != NULL, "TypeKlassPtr required.");
718 ciKlass* cik = kt->klass();
719 PointsToNode::EscapeState es = PointsToNode::NoEscape;
720 bool scalar_replaceable = true;
721 if (call->is_AllocateArray()) {
722 if (!cik->is_array_klass()) { // StressReflectiveCode
723 es = PointsToNode::GlobalEscape;
724 } else {
725 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
726 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
727 // Not scalar replaceable if the length is not constant or too big.
728 scalar_replaceable = false;
729 }
730 }
731 } else { // Allocate instance
732 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
733 !cik->is_instance_klass() || // StressReflectiveCode
734 cik->as_instance_klass()->has_finalizer()) {
735 es = PointsToNode::GlobalEscape;
736 }
737 }
738 add_java_object(call, es);
739 PointsToNode* ptn = ptnode_adr(call_idx);
740 if (!scalar_replaceable && ptn->scalar_replaceable()) {
741 ptn->set_scalar_replaceable(false);
742 }
743 } else if (call->is_CallStaticJava()) {
744 // Call nodes could be different types:
745 //
746 // 1. CallDynamicJavaNode (what happened during call is unknown):
747 //
748 // - mapped to GlobalEscape JavaObject node if oop is returned;
749 //
750 // - all oop arguments are escaping globally;
751 //
752 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
753 //
754 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
755 //
756 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
757 // - mapped to NoEscape JavaObject node if non-escaping object allocated
758 // during call is returned;
759 // - mapped to ArgEscape LocalVar node pointed to object arguments
760 // which are returned and does not escape during call;
761 //
762 // - oop arguments escaping status is defined by bytecode analysis;
763 //
764 // For a static call, we know exactly what method is being called.
765 // Use bytecode estimator to record whether the call's return value escapes.
766 ciMethod* meth = call->as_CallJava()->method();
767 if (meth == NULL) {
768 const char* name = call->as_CallStaticJava()->_name;
769 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
770 // Returns a newly allocated unescaped object.
771 add_java_object(call, PointsToNode::NoEscape);
772 ptnode_adr(call_idx)->set_scalar_replaceable(false);
773 } else {
774 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
775 call_analyzer->copy_dependencies(_compile->dependencies());
776 if (call_analyzer->is_return_allocated()) {
777 // Returns a newly allocated unescaped object, simply
778 // update dependency information.
779 // Mark it as NoEscape so that objects referenced by
780 // it's fields will be marked as NoEscape at least.
781 add_java_object(call, PointsToNode::NoEscape);
782 ptnode_adr(call_idx)->set_scalar_replaceable(false);
783 } else {
784 // Determine whether any arguments are returned.
785 const TypeTuple* d = call->tf()->domain();
786 bool ret_arg = false;
787 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
788 if (d->field_at(i)->isa_ptr() != NULL &&
789 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
790 ret_arg = true;
791 break;
792 }
793 }
794 if (ret_arg) {
795 add_local_var(call, PointsToNode::ArgEscape);
796 } else {
797 // Returns unknown object.
798 map_ideal_node(call, phantom_obj);
799 }
800 }
801 }
802 } else {
803 // An other type of call, assume the worst case:
804 // returned value is unknown and globally escapes.
805 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
806 map_ideal_node(call, phantom_obj);
807 }
808 }
809
810 void ConnectionGraph::process_call_arguments(CallNode *call) {
811 bool is_arraycopy = false;
812 switch (call->Opcode()) {
813 #ifdef ASSERT
814 case Op_Allocate:
815 case Op_AllocateArray:
816 case Op_Lock:
817 case Op_Unlock:
818 assert(false, "should be done already");
819 break;
820 #endif
821 case Op_CallLeafNoFP:
822 is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
823 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
824 // fall through
825 case Op_CallLeaf: {
826 // Stub calls, objects do not escape but they are not scale replaceable.
827 // Adjust escape state for outgoing arguments.
828 const TypeTuple * d = call->tf()->domain();
829 bool src_has_oops = false;
830 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
831 const Type* at = d->field_at(i);
832 Node *arg = call->in(i);
833 const Type *aat = _igvn->type(arg);
834 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
835 continue;
836 if (arg->is_AddP()) {
837 //
838 // The inline_native_clone() case when the arraycopy stub is called
839 // after the allocation before Initialize and CheckCastPP nodes.
840 // Or normal arraycopy for object arrays case.
841 //
842 // Set AddP's base (Allocate) as not scalar replaceable since
843 // pointer to the base (with offset) is passed as argument.
844 //
845 arg = get_addp_base(arg);
846 }
847 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
848 assert(arg_ptn != NULL, "should be registered");
849 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
850 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
851 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
852 aat->isa_ptr() != NULL, "expecting an Ptr");
853 bool arg_has_oops = aat->isa_oopptr() &&
854 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
855 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
856 if (i == TypeFunc::Parms) {
857 src_has_oops = arg_has_oops;
858 }
859 //
860 // src or dst could be j.l.Object when other is basic type array:
861 //
862 // arraycopy(char[],0,Object*,0,size);
863 // arraycopy(Object*,0,char[],0,size);
864 //
865 // Don't add edges in such cases.
866 //
867 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
868 arg_has_oops && (i > TypeFunc::Parms);
869 #ifdef ASSERT
870 if (!(is_arraycopy ||
871 call->as_CallLeaf()->_name != NULL &&
872 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
873 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
874 ) {
875 call->dump();
876 assert(false, "EA: unexpected CallLeaf");
877 }
878 #endif
879 // Always process arraycopy's destination object since
880 // we need to add all possible edges to references in
881 // source object.
882 if (arg_esc >= PointsToNode::ArgEscape &&
883 !arg_is_arraycopy_dest) {
884 continue;
885 }
886 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
887 if (arg_is_arraycopy_dest) {
888 Node* src = call->in(TypeFunc::Parms);
889 if (src->is_AddP()) {
890 src = get_addp_base(src);
891 }
892 PointsToNode* src_ptn = ptnode_adr(src->_idx);
893 assert(src_ptn != NULL, "should be registered");
894 if (arg_ptn != src_ptn) {
895 // Special arraycopy edge:
896 // A destination object's field can't have the source object
897 // as base since objects escape states are not related.
898 // Only escape state of destination object's fields affects
899 // escape state of fields in source object.
900 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
901 }
902 }
903 }
904 }
905 break;
906 }
907 case Op_CallStaticJava: {
908 // For a static call, we know exactly what method is being called.
909 // Use bytecode estimator to record the call's escape affects
910 #ifdef ASSERT
911 const char* name = call->as_CallStaticJava()->_name;
912 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
913 #endif
914 ciMethod* meth = call->as_CallJava()->method();
915 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
916 // fall-through if not a Java method or no analyzer information
917 if (call_analyzer != NULL) {
918 PointsToNode* call_ptn = ptnode_adr(call->_idx);
919 const TypeTuple* d = call->tf()->domain();
920 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
921 const Type* at = d->field_at(i);
922 int k = i - TypeFunc::Parms;
923 Node* arg = call->in(i);
924 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
925 if (at->isa_ptr() != NULL &&
926 call_analyzer->is_arg_returned(k)) {
927 // The call returns arguments.
928 if (call_ptn != NULL) { // Is call's result used?
929 assert(call_ptn->is_LocalVar(), "node should be registered");
930 assert(arg_ptn != NULL, "node should be registered");
931 add_edge(call_ptn, arg_ptn);
932 }
933 }
934 if (at->isa_oopptr() != NULL &&
935 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
936 if (!call_analyzer->is_arg_stack(k)) {
937 // The argument global escapes
938 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
939 } else {
940 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
941 if (!call_analyzer->is_arg_local(k)) {
942 // The argument itself doesn't escape, but any fields might
943 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
944 }
945 }
946 }
947 }
948 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
949 // The call returns arguments.
950 assert(call_ptn->edge_count() > 0, "sanity");
951 if (!call_analyzer->is_return_local()) {
952 // Returns also unknown object.
953 add_edge(call_ptn, phantom_obj);
954 }
955 }
956 break;
957 }
958 }
959 default: {
960 // Fall-through here if not a Java method or no analyzer information
961 // or some other type of call, assume the worst case: all arguments
962 // globally escape.
963 const TypeTuple* d = call->tf()->domain();
964 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
965 const Type* at = d->field_at(i);
966 if (at->isa_oopptr() != NULL) {
967 Node* arg = call->in(i);
968 if (arg->is_AddP()) {
969 arg = get_addp_base(arg);
970 }
971 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
972 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
973 }
974 }
975 }
976 }
977 }
978
979
980 // Finish Graph construction.
981 bool ConnectionGraph::complete_connection_graph(
982 GrowableArray<PointsToNode*>& ptnodes_worklist,
983 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
984 GrowableArray<JavaObjectNode*>& java_objects_worklist,
985 GrowableArray<FieldNode*>& oop_fields_worklist) {
986 // Normally only 1-3 passes needed to build Connection Graph depending
987 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
988 // Set limit to 20 to catch situation when something did go wrong and
989 // bailout Escape Analysis.
990 // Also limit build time to 30 sec (60 in debug VM).
991 #define CG_BUILD_ITER_LIMIT 20
992 #ifdef ASSERT
993 #define CG_BUILD_TIME_LIMIT 60.0
994 #else
995 #define CG_BUILD_TIME_LIMIT 30.0
996 #endif
997
998 // Propagate GlobalEscape and ArgEscape escape states and check that
999 // we still have non-escaping objects. The method pushs on _worklist
1000 // Field nodes which reference phantom_object.
1001 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1002 return false; // Nothing to do.
1003 }
1004 // Now propagate references to all JavaObject nodes.
1005 int java_objects_length = java_objects_worklist.length();
1006 elapsedTimer time;
1007 int new_edges = 1;
1008 int iterations = 0;
1009 do {
1010 while ((new_edges > 0) &&
1011 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1012 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1013 time.start();
1014 new_edges = 0;
1015 // Propagate references to phantom_object for nodes pushed on _worklist
1016 // by find_non_escaped_objects() and find_field_value().
1017 new_edges += add_java_object_edges(phantom_obj, false);
1018 for (int next = 0; next < java_objects_length; ++next) {
1019 JavaObjectNode* ptn = java_objects_worklist.at(next);
1020 new_edges += add_java_object_edges(ptn, true);
1021 }
1022 if (new_edges > 0) {
1023 // Update escape states on each iteration if graph was updated.
1024 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1025 return false; // Nothing to do.
1026 }
1027 }
1028 time.stop();
1029 }
1030 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1031 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1032 time.start();
1033 // Find fields which have unknown value.
1034 int fields_length = oop_fields_worklist.length();
1035 for (int next = 0; next < fields_length; next++) {
1036 FieldNode* field = oop_fields_worklist.at(next);
1037 if (field->edge_count() == 0) {
1038 new_edges += find_field_value(field);
1039 // This code may added new edges to phantom_object.
1040 // Need an other cycle to propagate references to phantom_object.
1041 }
1042 }
1043 time.stop();
1044 } else {
1045 new_edges = 0; // Bailout
1046 }
1047 } while (new_edges > 0);
1048
1049 // Bailout if passed limits.
1050 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1051 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1052 Compile* C = _compile;
1053 if (C->log() != NULL) {
1054 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1055 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1056 C->log()->end_elem(" limit'");
1057 }
1058 assert(false, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1059 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1060 // Possible infinite build_connection_graph loop,
1061 // bailout (no changes to ideal graph were made).
1062 return false;
1063 }
1064 #ifdef ASSERT
1065 if (Verbose && PrintEscapeAnalysis) {
1066 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1067 iterations, nodes_size(), ptnodes_worklist.length());
1068 }
1069 #endif
1070
1071 #undef CG_BUILD_ITER_LIMIT
1072 #undef CG_BUILD_TIME_LIMIT
1073
1074 // Find fields initialized by NULL for non-escaping Allocations.
1075 int non_escaped_length = non_escaped_worklist.length();
1076 for (int next = 0; next < non_escaped_length; next++) {
1077 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1078 PointsToNode::EscapeState es = ptn->escape_state();
1079 assert(es <= PointsToNode::ArgEscape, "sanity");
1080 if (es == PointsToNode::NoEscape) {
1081 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1082 // Adding references to NULL object does not change escape states
1083 // since it does not escape. Also no fields are added to NULL object.
1084 add_java_object_edges(null_obj, false);
1085 }
1086 }
1087 Node* n = ptn->ideal_node();
1088 if (n->is_Allocate()) {
1089 // The object allocated by this Allocate node will never be
1090 // seen by an other thread. Mark it so that when it is
1091 // expanded no MemBarStoreStore is added.
1092 InitializeNode* ini = n->as_Allocate()->initialization();
1093 if (ini != NULL)
1094 ini->set_does_not_escape();
1095 }
1096 }
1097 return true; // Finished graph construction.
1098 }
1099
1100 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1101 // and check that we still have non-escaping java objects.
1102 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1103 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1104 GrowableArray<PointsToNode*> escape_worklist;
1105 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1106 int ptnodes_length = ptnodes_worklist.length();
1107 for (int next = 0; next < ptnodes_length; ++next) {
1108 PointsToNode* ptn = ptnodes_worklist.at(next);
1109 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1110 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1111 escape_worklist.push(ptn);
1112 }
1113 }
1114 // Set escape states to referenced nodes (edges list).
1115 while (escape_worklist.length() > 0) {
1116 PointsToNode* ptn = escape_worklist.pop();
1117 PointsToNode::EscapeState es = ptn->escape_state();
1118 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1119 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1120 es >= PointsToNode::ArgEscape) {
1121 // GlobalEscape or ArgEscape state of field means it has unknown value.
1122 if (add_edge(ptn, phantom_obj)) {
1123 // New edge was added
1124 add_field_uses_to_worklist(ptn->as_Field());
1125 }
1126 }
1127 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1128 PointsToNode* e = i.get();
1129 if (e->is_Arraycopy()) {
1130 assert(ptn->arraycopy_dst(), "sanity");
1131 // Propagate only fields escape state through arraycopy edge.
1132 if (e->fields_escape_state() < field_es) {
1133 set_fields_escape_state(e, field_es);
1134 escape_worklist.push(e);
1135 }
1136 } else if (es >= field_es) {
1137 // fields_escape_state is also set to 'es' if it is less than 'es'.
1138 if (e->escape_state() < es) {
1139 set_escape_state(e, es);
1140 escape_worklist.push(e);
1141 }
1142 } else {
1143 // Propagate field escape state.
1144 bool es_changed = false;
1145 if (e->fields_escape_state() < field_es) {
1146 set_fields_escape_state(e, field_es);
1147 es_changed = true;
1148 }
1149 if ((e->escape_state() < field_es) &&
1150 e->is_Field() && ptn->is_JavaObject() &&
1151 e->as_Field()->is_oop()) {
1152 // Change escape state of referenced fileds.
1153 set_escape_state(e, field_es);
1154 es_changed = true;;
1155 } else if (e->escape_state() < es) {
1156 set_escape_state(e, es);
1157 es_changed = true;;
1158 }
1159 if (es_changed) {
1160 escape_worklist.push(e);
1161 }
1162 }
1163 }
1164 }
1165 // Remove escaped objects from non_escaped list.
1166 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1167 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1168 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1169 non_escaped_worklist.delete_at(next);
1170 }
1171 if (ptn->escape_state() == PointsToNode::NoEscape) {
1172 // Find fields in non-escaped allocations which have unknown value.
1173 find_init_values(ptn, phantom_obj, NULL);
1174 }
1175 }
1176 return (non_escaped_worklist.length() > 0);
1177 }
1178
1179 // Add all references to JavaObject node by walking over all uses.
1180 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1181 int new_edges = 0;
1182 if (populate_worklist) {
1183 // Populate _worklist by uses of jobj's uses.
1184 for (UseIterator i(jobj); i.has_next(); i.next()) {
1185 PointsToNode* use = i.get();
1186 if (use->is_Arraycopy())
1187 continue;
1188 add_uses_to_worklist(use);
1189 if (use->is_Field() && use->as_Field()->is_oop()) {
1190 // Put on worklist all field's uses (loads) and
1191 // related field nodes (same base and offset).
1192 add_field_uses_to_worklist(use->as_Field());
1193 }
1194 }
1195 }
1196 while(_worklist.length() > 0) {
1197 PointsToNode* use = _worklist.pop();
1198 if (PointsToNode::is_base_use(use)) {
1199 // Add reference from jobj to field and from field to jobj (field's base).
1200 use = PointsToNode::get_use_node(use)->as_Field();
1201 if (add_base(use->as_Field(), jobj)) {
1202 new_edges++;
1203 }
1204 continue;
1205 }
1206 assert(!use->is_JavaObject(), "sanity");
1207 if (use->is_Arraycopy()) {
1208 if (jobj == null_obj) // NULL object does not have field edges
1209 continue;
1210 // Added edge from Arraycopy node to arraycopy's source java object
1211 if (add_edge(use, jobj)) {
1212 jobj->set_arraycopy_src();
1213 new_edges++;
1214 }
1215 // and stop here.
1216 continue;
1217 }
1218 if (!add_edge(use, jobj))
1219 continue; // No new edge added, there was such edge already.
1220 new_edges++;
1221 if (use->is_LocalVar()) {
1222 add_uses_to_worklist(use);
1223 if (use->arraycopy_dst()) {
1224 for (EdgeIterator i(use); i.has_next(); i.next()) {
1225 PointsToNode* e = i.get();
1226 if (e->is_Arraycopy()) {
1227 if (jobj == null_obj) // NULL object does not have field edges
1228 continue;
1229 // Add edge from arraycopy's destination java object to Arraycopy node.
1230 if (add_edge(jobj, e)) {
1231 new_edges++;
1232 jobj->set_arraycopy_dst();
1233 }
1234 }
1235 }
1236 }
1237 } else {
1238 // Added new edge to stored in field values.
1239 // Put on worklist all field's uses (loads) and
1240 // related field nodes (same base and offset).
1241 add_field_uses_to_worklist(use->as_Field());
1242 }
1243 }
1244 return new_edges;
1245 }
1246
1247 // Put on worklist all related field nodes.
1248 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1249 assert(field->is_oop(), "sanity");
1250 int offset = field->offset();
1251 add_uses_to_worklist(field);
1252 // Loop over all bases of this field and push on worklist Field nodes
1253 // with the same offset and base (since they may reference the same field).
1254 for (BaseIterator i(field); i.has_next(); i.next()) {
1255 PointsToNode* base = i.get();
1256 add_fields_to_worklist(field, base);
1257 // Check if the base was source object of arraycopy and go over arraycopy's
1258 // destination objects since values stored to a field of source object are
1259 // accessable by uses (loads) of fields of destination objects.
1260 if (base->arraycopy_src()) {
1261 for (UseIterator j(base); j.has_next(); j.next()) {
1262 PointsToNode* arycp = j.get();
1263 if (arycp->is_Arraycopy()) {
1264 for (UseIterator k(arycp); k.has_next(); k.next()) {
1265 PointsToNode* abase = k.get();
1266 if (abase->arraycopy_dst() && abase != base) {
1267 // Look for the same arracopy reference.
1268 add_fields_to_worklist(field, abase);
1269 }
1270 }
1271 }
1272 }
1273 }
1274 }
1275 }
1276
1277 // Put on worklist all related field nodes.
1278 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1279 int offset = field->offset();
1280 if (base->is_LocalVar()) {
1281 for (UseIterator j(base); j.has_next(); j.next()) {
1282 PointsToNode* f = j.get();
1283 if (PointsToNode::is_base_use(f)) { // Field
1284 f = PointsToNode::get_use_node(f);
1285 if (f == field || !f->as_Field()->is_oop())
1286 continue;
1287 int offs = f->as_Field()->offset();
1288 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1289 add_to_worklist(f);
1290 }
1291 }
1292 }
1293 } else {
1294 assert(base->is_JavaObject(), "sanity");
1295 if (// Skip phantom_object since it is only used to indicate that
1296 // this field's content globally escapes.
1297 (base != phantom_obj) &&
1298 // NULL object node does not have fields.
1299 (base != null_obj)) {
1300 for (EdgeIterator i(base); i.has_next(); i.next()) {
1301 PointsToNode* f = i.get();
1302 // Skip arraycopy edge since store to destination object field
1303 // does not update value in source object field.
1304 if (f->is_Arraycopy()) {
1305 assert(base->arraycopy_dst(), "sanity");
1306 continue;
1307 }
1308 if (f == field || !f->as_Field()->is_oop())
1309 continue;
1310 int offs = f->as_Field()->offset();
1311 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1312 add_to_worklist(f);
1313 }
1314 }
1315 }
1316 }
1317 }
1318
1319 // Find fields which have unknown value.
1320 int ConnectionGraph::find_field_value(FieldNode* field) {
1321 // Escaped fields should have init value already.
1322 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1323 int new_edges = 0;
1324 for (BaseIterator i(field); i.has_next(); i.next()) {
1325 PointsToNode* base = i.get();
1326 if (base->is_JavaObject()) {
1327 // Skip Allocate's fields which will be processed later.
1328 if (base->ideal_node()->is_Allocate())
1329 return 0;
1330 assert(base == null_obj, "only NULL ptr base expected here");
1331 }
1332 }
1333 if (add_edge(field, phantom_obj)) {
1334 // New edge was added
1335 new_edges++;
1336 add_field_uses_to_worklist(field);
1337 }
1338 return new_edges;
1339 }
1340
1341 // Find fields initializing values for allocations.
1342 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1343 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1344 int new_edges = 0;
1345 Node* alloc = pta->ideal_node();
1346 if (init_val == phantom_obj) {
1347 // Do nothing for Allocate nodes since its fields values are "known".
1348 if (alloc->is_Allocate())
1349 return 0;
1350 assert(alloc->as_CallStaticJava(), "sanity");
1351 #ifdef ASSERT
1352 if (alloc->as_CallStaticJava()->method() == NULL) {
1353 const char* name = alloc->as_CallStaticJava()->_name;
1354 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1355 }
1356 #endif
1357 // Non-escaped allocation returned from Java or runtime call have
1358 // unknown values in fields.
1359 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1360 PointsToNode* ptn = i.get();
1361 if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
1362 if (add_edge(ptn, phantom_obj)) {
1363 // New edge was added
1364 new_edges++;
1365 add_field_uses_to_worklist(ptn->as_Field());
1366 }
1367 }
1368 }
1369 return new_edges;
1370 }
1371 assert(init_val == null_obj, "sanity");
1372 // Do nothing for Call nodes since its fields values are unknown.
1373 if (!alloc->is_Allocate())
1374 return 0;
1375
1376 InitializeNode* ini = alloc->as_Allocate()->initialization();
1377 Compile* C = _compile;
1378 bool visited_bottom_offset = false;
1379 GrowableArray<int> offsets_worklist;
1380
1381 // Check if an oop field's initializing value is recorded and add
1382 // a corresponding NULL if field's value if it is not recorded.
1383 // Connection Graph does not record a default initialization by NULL
1384 // captured by Initialize node.
1385 //
1386 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1387 PointsToNode* ptn = i.get(); // Field (AddP)
1388 if (!ptn->is_Field() || !ptn->as_Field()->is_oop())
1389 continue; // Not oop field
1390 int offset = ptn->as_Field()->offset();
1391 if (offset == Type::OffsetBot) {
1392 if (!visited_bottom_offset) {
1393 // OffsetBot is used to reference array's element,
1394 // always add reference to NULL to all Field nodes since we don't
1395 // known which element is referenced.
1396 if (add_edge(ptn, null_obj)) {
1397 // New edge was added
1398 new_edges++;
1399 add_field_uses_to_worklist(ptn->as_Field());
1400 visited_bottom_offset = true;
1401 }
1402 }
1403 } else {
1404 // Check only oop fields.
1405 const Type* adr_type = ptn->ideal_node()->as_AddP()->bottom_type();
1406 if (adr_type->isa_rawptr()) {
1407 #ifdef ASSERT
1408 // Raw pointers are used for initializing stores so skip it
1409 // since it should be recorded already
1410 Node* base = get_addp_base(ptn->ideal_node());
1411 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1412 (base->in(0) == alloc),"unexpected pointer type");
1413 #endif
1414 continue;
1415 }
1416 if (!offsets_worklist.contains(offset)) {
1417 offsets_worklist.append(offset);
1418 Node* value = NULL;
1419 if (ini != NULL) {
1420 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1421 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1422 if (store != NULL && store->is_Store()) {
1423 value = store->in(MemNode::ValueIn);
1424 } else {
1425 // There could be initializing stores which follow allocation.
1426 // For example, a volatile field store is not collected
1427 // by Initialize node.
1428 //
1429 // Need to check for dependent loads to separate such stores from
1430 // stores which follow loads. For now, add initial value NULL so
1431 // that compare pointers optimization works correctly.
1432 }
1433 }
1434 if (value == NULL) {
1435 // A field's initializing value was not recorded. Add NULL.
1436 if (add_edge(ptn, null_obj)) {
1437 // New edge was added
1438 new_edges++;
1439 add_field_uses_to_worklist(ptn->as_Field());
1440 }
1441 }
1442 }
1443 }
1444 }
1445 return new_edges;
1446 }
1447
1448 // Adjust scalar_replaceable state after Connection Graph is built.
1449 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1450 // Search for non-escaping objects which are not scalar replaceable
1451 // and mark them to propagate the state to referenced objects.
1452
1453 // 1. An object is not scalar replaceable if the field into which it is
1454 // stored has unknown offset (stored into unknown element of an array).
1455 //
1456 for (UseIterator i(jobj); i.has_next(); i.next()) {
1457 PointsToNode* use = i.get();
1458 assert(!use->is_Arraycopy(), "sanity");
1459 if (use->is_Field()) {
1460 FieldNode* field = use->as_Field();
1461 assert(field->is_oop() && field->scalar_replaceable() &&
1462 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1463 if (field->offset() == Type::OffsetBot) {
1464 jobj->set_scalar_replaceable(false);
1465 return;
1466 }
1467 }
1468 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1469 // 2. An object is not scalar replaceable if it is merged with other objects.
1470 for (EdgeIterator j(use); j.has_next(); j.next()) {
1471 PointsToNode* ptn = j.get();
1472 if (ptn->is_JavaObject() && ptn != jobj) {
1473 // Mark all objects.
1474 jobj->set_scalar_replaceable(false);
1475 ptn->set_scalar_replaceable(false);
1476 }
1477 }
1478 if (!jobj->scalar_replaceable()) {
1479 return;
1480 }
1481 }
1482
1483 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1484 // Non-escaping object node should point only to field nodes.
1485 FieldNode* field = j.get()->as_Field();
1486 int offset = field->as_Field()->offset();
1487
1488 // 3. An object is not scalar replaceable if it has a field with unknown
1489 // offset (array's element is accessed in loop).
1490 if (offset == Type::OffsetBot) {
1491 jobj->set_scalar_replaceable(false);
1492 return;
1493 }
1494 // 4. Currently an object is not scalar replaceable if a LoadStore node
1495 // access its field since the field value is unknown after it.
1496 //
1497 Node* n = field->ideal_node();
1498 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1499 if (n->fast_out(i)->is_LoadStore()) {
1500 jobj->set_scalar_replaceable(false);
1501 return;
1502 }
1503 }
1504
1505 // 5. Or the address may point to more then one object. This may produce
1506 // the false positive result (set not scalar replaceable)
1507 // since the flow-insensitive escape analysis can't separate
1508 // the case when stores overwrite the field's value from the case
1509 // when stores happened on different control branches.
1510 //
1511 // Note: it will disable scalar replacement in some cases:
1512 //
1513 // Point p[] = new Point[1];
1514 // p[0] = new Point(); // Will be not scalar replaced
1515 //
1516 // but it will save us from incorrect optimizations in next cases:
1517 //
1518 // Point p[] = new Point[1];
1519 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1520 //
1521 if (field->base_count() > 1) {
1522 for (BaseIterator i(field); i.has_next(); i.next()) {
1523 PointsToNode* base = i.get();
1524 // Don't take into account LocalVar nodes which
1525 // may point to only one object which should be also
1526 // this field's base by now.
1527 if (base->is_JavaObject() && base != jobj) {
1528 // Mark all bases.
1529 jobj->set_scalar_replaceable(false);
1530 base->set_scalar_replaceable(false);
1531 }
1532 }
1533 }
1534 }
1535 }
1536
1537 #ifdef ASSERT
1538 void ConnectionGraph::verify_connection_graph(
1539 GrowableArray<PointsToNode*>& ptnodes_worklist,
1540 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1541 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1542 GrowableArray<Node*>& addp_worklist) {
1543 // Verify that graph is complete - no new edges could be added.
1544 int java_objects_length = java_objects_worklist.length();
1545 int non_escaped_length = non_escaped_worklist.length();
1546 int new_edges = 0;
1547 for (int next = 0; next < java_objects_length; ++next) {
1548 JavaObjectNode* ptn = java_objects_worklist.at(next);
1549 new_edges += add_java_object_edges(ptn, true);
1550 }
1551 assert(new_edges == 0, "graph was not complete");
1552 // Verify that escape state is final.
1553 int length = non_escaped_worklist.length();
1554 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1555 assert((non_escaped_length == non_escaped_worklist.length()) &&
1556 (non_escaped_length == length) &&
1557 (_worklist.length() == 0), "escape state was not final");
1558
1559 // Verify fields information.
1560 int addp_length = addp_worklist.length();
1561 for (int next = 0; next < addp_length; ++next ) {
1562 Node* n = addp_worklist.at(next);
1563 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1564 if (field->is_oop()) {
1565 // Verify that field has all bases
1566 Node* base = get_addp_base(n);
1567 PointsToNode* ptn = ptnode_adr(base->_idx);
1568 if (ptn->is_JavaObject()) {
1569 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1570 } else {
1571 assert(ptn->is_LocalVar(), "sanity");
1572 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1573 PointsToNode* e = i.get();
1574 if (e->is_JavaObject()) {
1575 assert(field->has_base(e->as_JavaObject()), "sanity");
1576 }
1577 }
1578 }
1579 // Verify that all fields have initializing values.
1580 if (field->edge_count() == 0) {
1581 field->dump();
1582 assert(field->edge_count() > 0, "sanity");
1583 }
1584 }
1585 }
1586 }
1587 #endif
1588
1589 // Optimize ideal graph.
1590 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1591 GrowableArray<Node*>& storestore_worklist) {
1592 Compile* C = _compile;
1593 PhaseIterGVN* igvn = _igvn;
1594 if (EliminateLocks) {
1595 // Mark locks before changing ideal graph.
1596 int cnt = C->macro_count();
1597 for( int i=0; i < cnt; i++ ) {
1598 Node *n = C->macro_node(i);
1599 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1600 AbstractLockNode* alock = n->as_AbstractLock();
1601 if (!alock->is_non_esc_obj()) {
1602 if (not_global_escape(alock->obj_node())) {
1603 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1604 // The lock could be marked eliminated by lock coarsening
1605 // code during first IGVN before EA. Replace coarsened flag
1606 // to eliminate all associated locks/unlocks.
1607 alock->set_non_esc_obj();
1608 }
1609 }
1610 }
1611 }
1612 }
1613
1614 if (OptimizePtrCompare) {
1615 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1616 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1617 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1618 // Optimize objects compare.
1619 while (ptr_cmp_worklist.length() != 0) {
1620 Node *n = ptr_cmp_worklist.pop();
1621 Node *res = optimize_ptr_compare(n);
1622 if (res != NULL) {
1623 #ifndef PRODUCT
1624 if (PrintOptimizePtrCompare) {
1625 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"));
1626 if (Verbose) {
1627 n->dump(1);
1628 }
1629 }
1630 #endif
1631 igvn->replace_node(n, res);
1632 }
1633 }
1634 // cleanup
1635 if (_pcmp_neq->outcnt() == 0)
1636 igvn->hash_delete(_pcmp_neq);
1637 if (_pcmp_eq->outcnt() == 0)
1638 igvn->hash_delete(_pcmp_eq);
1639 }
1640
1641 // For MemBarStoreStore nodes added in library_call.cpp, check
1642 // escape status of associated AllocateNode and optimize out
1643 // MemBarStoreStore node if the allocated object never escapes.
1644 while (storestore_worklist.length() != 0) {
1645 Node *n = storestore_worklist.pop();
1646 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1647 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1648 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1649 if (not_global_escape(alloc)) {
1650 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1651 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1652 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1653 igvn->register_new_node_with_optimizer(mb);
1654 igvn->replace_node(storestore, mb);
1655 }
1656 }
1657 }
1658
1659 // Optimize objects compare.
1660 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1661 assert(OptimizePtrCompare, "sanity");
1662 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1663 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1664 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1665 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1666 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1667 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1668
1669 // Check simple cases first.
1670 if (jobj1 != NULL) {
1671 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1672 if (jobj1 == jobj2) {
1673 // Comparing the same not escaping object.
1674 return _pcmp_eq;
1675 }
1676 Node* obj = jobj1->ideal_node();
1677 // Comparing not escaping allocation.
1678 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1679 !ptn2->points_to(jobj1)) {
1680 return _pcmp_neq; // This includes nullness check.
1681 }
1682 }
1683 }
1684 if (jobj2 != NULL) {
1685 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1686 Node* obj = jobj2->ideal_node();
1687 // Comparing not escaping allocation.
1688 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1689 !ptn1->points_to(jobj2)) {
1690 return _pcmp_neq; // This includes nullness check.
1691 }
1692 }
1693 }
1694 if (jobj1 != NULL && jobj1 != phantom_obj &&
1695 jobj2 != NULL && jobj2 != phantom_obj &&
1696 jobj1->ideal_node()->is_Con() &&
1697 jobj2->ideal_node()->is_Con()) {
1698 // Klass or String constants compare. Need to be careful with
1699 // compressed pointers - compare types of ConN and ConP instead of nodes.
1700 const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr();
1701 const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr();
1702 assert(t1 != NULL && t2 != NULL, "sanity");
1703 if (t1->make_ptr() == t2->make_ptr()) {
1704 return _pcmp_eq;
1705 } else {
1706 return _pcmp_neq;
1707 }
1708 }
1709 if (ptn1->meet(ptn2)) {
1710 return NULL; // Sets are not disjoint
1711 }
1712
1713 // Sets are disjoint.
1714 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1715 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1716 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1717 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1718 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1719 set2_has_unknown_ptr && set1_has_null_ptr) {
1720 // Check nullness of unknown object.
1721 return NULL;
1722 }
1723
1724 // Disjointness by itself is not sufficient since
1725 // alias analysis is not complete for escaped objects.
1726 // Disjoint sets are definitely unrelated only when
1727 // at least one set has only not escaping allocations.
1728 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1729 if (ptn1->non_escaping_allocation()) {
1730 return _pcmp_neq;
1731 }
1732 }
1733 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1734 if (ptn2->non_escaping_allocation()) {
1735 return _pcmp_neq;
1736 }
1737 }
1738 return NULL;
1739 }
1740
1741 // Connection Graph constuction functions.
1742
1743 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1744 PointsToNode* ptadr = _nodes.at(n->_idx);
1745 if (ptadr != NULL) {
1746 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1747 return;
1748 }
1749 Compile* C = _compile;
1750 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1751 _nodes.at_put(n->_idx, ptadr);
1752 }
1753
1754 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1755 PointsToNode* ptadr = _nodes.at(n->_idx);
1756 if (ptadr != NULL) {
1757 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1758 return;
1759 }
1760 Compile* C = _compile;
1761 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1762 _nodes.at_put(n->_idx, ptadr);
1763 }
1764
1765 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1766 PointsToNode* ptadr = _nodes.at(n->_idx);
1767 if (ptadr != NULL) {
1768 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1769 return;
1770 }
1771 bool unsafe = false;
1772 bool is_oop = is_oop_field(n, offset, &unsafe);
1773 if (unsafe) {
1774 es = PointsToNode::GlobalEscape;
1775 }
1776 Compile* C = _compile;
1777 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1778 _nodes.at_put(n->_idx, field);
1779 }
1780
1781 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1782 PointsToNode* src, PointsToNode* dst) {
1783 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1784 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1785 PointsToNode* ptadr = _nodes.at(n->_idx);
1786 if (ptadr != NULL) {
1787 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1788 return;
1789 }
1790 Compile* C = _compile;
1791 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1792 _nodes.at_put(n->_idx, ptadr);
1793 // Add edge from arraycopy node to source object.
1794 (void)add_edge(ptadr, src);
1795 src->set_arraycopy_src();
1796 // Add edge from destination object to arraycopy node.
1797 (void)add_edge(dst, ptadr);
1798 dst->set_arraycopy_dst();
1799 }
1800
1801 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1802 const Type* adr_type = n->as_AddP()->bottom_type();
1803 BasicType bt = T_INT;
1804 if (offset == Type::OffsetBot) {
1805 // Check only oop fields.
1806 if (!adr_type->isa_aryptr() ||
1807 (adr_type->isa_aryptr()->klass() == NULL) ||
1808 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1809 // OffsetBot is used to reference array's element. Ignore first AddP.
1810 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1811 bt = T_OBJECT;
1812 }
1813 }
1814 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1815 if (adr_type->isa_instptr()) {
1816 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1817 if (field != NULL) {
1818 bt = field->layout_type();
1819 } else {
1820 // Check for unsafe oop field access
1821 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1822 int opcode = n->fast_out(i)->Opcode();
1823 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1824 opcode == Op_StoreN || opcode == Op_LoadN) {
1825 bt = T_OBJECT;
1826 (*unsafe) = true;
1827 break;
1828 }
1829 }
1830 }
1831 } else if (adr_type->isa_aryptr()) {
1832 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1833 // Ignore array length load.
1834 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1835 // Ignore first AddP.
1836 } else {
1837 const Type* elemtype = adr_type->isa_aryptr()->elem();
1838 bt = elemtype->array_element_basic_type();
1839 }
1840 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
1841 // Allocation initialization, ThreadLocal field access, unsafe access
1842 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1843 int opcode = n->fast_out(i)->Opcode();
1844 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1845 opcode == Op_StoreN || opcode == Op_LoadN) {
1846 bt = T_OBJECT;
1847 break;
1848 }
1849 }
1850 }
1851 }
1852 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
1853 }
1854
1855 // Returns unique pointed java object or NULL.
1856 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
1857 assert(!_collecting, "should not call when contructed graph");
1858 // If the node was created after the escape computation we can't answer.
1859 uint idx = n->_idx;
1860 if (idx >= nodes_size()) {
1861 return NULL;
1862 }
1863 PointsToNode* ptn = ptnode_adr(idx);
1864 if (ptn->is_JavaObject()) {
1865 return ptn->as_JavaObject();
1866 }
1867 assert(ptn->is_LocalVar(), "sanity");
1868 // Check all java objects it points to.
1869 JavaObjectNode* jobj = NULL;
1870 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1871 PointsToNode* e = i.get();
1872 if (e->is_JavaObject()) {
1873 if (jobj == NULL) {
1874 jobj = e->as_JavaObject();
1875 } else if (jobj != e) {
1876 return NULL;
1877 }
1878 }
1879 }
1880 return jobj;
1881 }
1882
1883 // Return true if this node points only to non-escaping allocations.
1884 bool PointsToNode::non_escaping_allocation() {
1885 if (is_JavaObject()) {
1886 Node* n = ideal_node();
1887 if (n->is_Allocate() || n->is_CallStaticJava()) {
1888 return (escape_state() == PointsToNode::NoEscape);
1889 } else {
1890 return false;
1891 }
1892 }
1893 assert(is_LocalVar(), "sanity");
1894 // Check all java objects it points to.
1895 for (EdgeIterator i(this); i.has_next(); i.next()) {
1896 PointsToNode* e = i.get();
1897 if (e->is_JavaObject()) {
1898 Node* n = e->ideal_node();
1899 if ((e->escape_state() != PointsToNode::NoEscape) ||
1900 !(n->is_Allocate() || n->is_CallStaticJava())) {
1901 return false;
1902 }
1903 }
1904 }
1905 return true;
1906 }
1907
1908 // Return true if we know the node does not escape globally.
1909 bool ConnectionGraph::not_global_escape(Node *n) {
1910 assert(!_collecting, "should not call during graph construction");
1911 // If the node was created after the escape computation we can't answer.
1912 uint idx = n->_idx;
1913 if (idx >= nodes_size()) {
1914 return false;
1915 }
1916 PointsToNode* ptn = ptnode_adr(idx);
1917 PointsToNode::EscapeState es = ptn->escape_state();
1918 // If we have already computed a value, return it.
1919 if (es >= PointsToNode::GlobalEscape)
1920 return false;
1921 if (ptn->is_JavaObject()) {
1922 return true; // (es < PointsToNode::GlobalEscape);
1923 }
1924 assert(ptn->is_LocalVar(), "sanity");
1925 // Check all java objects it points to.
1926 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1927 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
1928 return false;
1929 }
1930 return true;
1931 }
1932
1933
1934 // Helper functions
1935
1936 // Return true if this node points to specified node or nodes it points to.
1937 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
1938 if (is_JavaObject()) {
1939 return (this == ptn);
1940 }
1941 assert(is_LocalVar(), "sanity");
1942 for (EdgeIterator i(this); i.has_next(); i.next()) {
1943 if (i.get() == ptn)
1944 return true;
1945 }
1946 return false;
1947 }
1948
1949 // Return true if one node points to an other.
1950 bool PointsToNode::meet(PointsToNode* ptn) {
1951 if (this == ptn) {
1952 return true;
1953 } else if (ptn->is_JavaObject()) {
1954 return this->points_to(ptn->as_JavaObject());
1955 } else if (this->is_JavaObject()) {
1956 return ptn->points_to(this->as_JavaObject());
1957 }
1958 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
1959 int ptn_count = ptn->edge_count();
1960 for (EdgeIterator i(this); i.has_next(); i.next()) {
1961 PointsToNode* this_e = i.get();
1962 for (int j = 0; j < ptn_count; j++) {
1963 if (this_e == ptn->edge(j))
1964 return true;
1965 }
1966 }
1967 return false;
1968 }
1969
1970 #ifdef ASSERT
1971 // Return true if bases point to this java object.
1972 bool FieldNode::has_base(JavaObjectNode* jobj) const {
1973 for (BaseIterator i(this); i.has_next(); i.next()) {
1974 if (i.get() == jobj)
1975 return true;
1976 }
1977 return false;
1978 }
1979 #endif
1980
1981 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
1982 const Type *adr_type = phase->type(adr);
1983 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
1984 adr->in(AddPNode::Address)->is_Proj() &&
1985 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
1986 // We are computing a raw address for a store captured by an Initialize
1987 // compute an appropriate address type. AddP cases #3 and #5 (see below).
1988 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1989 assert(offs != Type::OffsetBot ||
1990 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
1991 "offset must be a constant or it is initialization of array");
1992 return offs;
1993 }
1994 const TypePtr *t_ptr = adr_type->isa_ptr();
1995 assert(t_ptr != NULL, "must be a pointer type");
1996 return t_ptr->offset();
1997 }
1998
1999 Node* ConnectionGraph::get_addp_base(Node *addp) {
2000 assert(addp->is_AddP(), "must be AddP");
2001 //
2002 // AddP cases for Base and Address inputs:
2003 // case #1. Direct object's field reference:
2004 // Allocate
2005 // |
2006 // Proj #5 ( oop result )
2007 // |
2008 // CheckCastPP (cast to instance type)
2009 // | |
2010 // AddP ( base == address )
2011 //
2012 // case #2. Indirect object's field reference:
2013 // Phi
2014 // |
2015 // CastPP (cast to instance type)
2016 // | |
2017 // AddP ( base == address )
2018 //
2019 // case #3. Raw object's field reference for Initialize node:
2020 // Allocate
2021 // |
2022 // Proj #5 ( oop result )
2023 // top |
2024 // \ |
2025 // AddP ( base == top )
2026 //
2027 // case #4. Array's element reference:
2028 // {CheckCastPP | CastPP}
2029 // | | |
2030 // | AddP ( array's element offset )
2031 // | |
2032 // AddP ( array's offset )
2033 //
2034 // case #5. Raw object's field reference for arraycopy stub call:
2035 // The inline_native_clone() case when the arraycopy stub is called
2036 // after the allocation before Initialize and CheckCastPP nodes.
2037 // Allocate
2038 // |
2039 // Proj #5 ( oop result )
2040 // | |
2041 // AddP ( base == address )
2042 //
2043 // case #6. Constant Pool, ThreadLocal, CastX2P or
2044 // Raw object's field reference:
2045 // {ConP, ThreadLocal, CastX2P, raw Load}
2046 // top |
2047 // \ |
2048 // AddP ( base == top )
2049 //
2050 // case #7. Klass's field reference.
2051 // LoadKlass
2052 // | |
2053 // AddP ( base == address )
2054 //
2055 // case #8. narrow Klass's field reference.
2056 // LoadNKlass
2057 // |
2058 // DecodeN
2059 // | |
2060 // AddP ( base == address )
2061 //
2062 Node *base = addp->in(AddPNode::Base);
2063 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2064 base = addp->in(AddPNode::Address);
2065 while (base->is_AddP()) {
2066 // Case #6 (unsafe access) may have several chained AddP nodes.
2067 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2068 base = base->in(AddPNode::Address);
2069 }
2070 Node* uncast_base = base->uncast();
2071 int opcode = uncast_base->Opcode();
2072 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2073 opcode == Op_CastX2P || uncast_base->is_DecodeN() ||
2074 (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
2075 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2076 }
2077 return base;
2078 }
2079
2080 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2081 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2082 Node* addp2 = addp->raw_out(0);
2083 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2084 addp2->in(AddPNode::Base) == n &&
2085 addp2->in(AddPNode::Address) == addp) {
2086 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2087 //
2088 // Find array's offset to push it on worklist first and
2089 // as result process an array's element offset first (pushed second)
2090 // to avoid CastPP for the array's offset.
2091 // Otherwise the inserted CastPP (LocalVar) will point to what
2092 // the AddP (Field) points to. Which would be wrong since
2093 // the algorithm expects the CastPP has the same point as
2094 // as AddP's base CheckCastPP (LocalVar).
2095 //
2096 // ArrayAllocation
2097 // |
2098 // CheckCastPP
2099 // |
2100 // memProj (from ArrayAllocation CheckCastPP)
2101 // | ||
2102 // | || Int (element index)
2103 // | || | ConI (log(element size))
2104 // | || | /
2105 // | || LShift
2106 // | || /
2107 // | AddP (array's element offset)
2108 // | |
2109 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2110 // | / /
2111 // AddP (array's offset)
2112 // |
2113 // Load/Store (memory operation on array's element)
2114 //
2115 return addp2;
2116 }
2117 return NULL;
2118 }
2119
2120 //
2121 // Adjust the type and inputs of an AddP which computes the
2122 // address of a field of an instance
2123 //
2124 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2125 PhaseGVN* igvn = _igvn;
2126 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2127 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2128 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2129 if (t == NULL) {
2130 // We are computing a raw address for a store captured by an Initialize
2131 // compute an appropriate address type (cases #3 and #5).
2132 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2133 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2134 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2135 assert(offs != Type::OffsetBot, "offset must be a constant");
2136 t = base_t->add_offset(offs)->is_oopptr();
2137 }
2138 int inst_id = base_t->instance_id();
2139 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2140 "old type must be non-instance or match new type");
2141
2142 // The type 't' could be subclass of 'base_t'.
2143 // As result t->offset() could be large then base_t's size and it will
2144 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2145 // constructor verifies correctness of the offset.
2146 //
2147 // It could happened on subclass's branch (from the type profiling
2148 // inlining) which was not eliminated during parsing since the exactness
2149 // of the allocation type was not propagated to the subclass type check.
2150 //
2151 // Or the type 't' could be not related to 'base_t' at all.
2152 // It could happened when CHA type is different from MDO type on a dead path
2153 // (for example, from instanceof check) which is not collapsed during parsing.
2154 //
2155 // Do nothing for such AddP node and don't process its users since
2156 // this code branch will go away.
2157 //
2158 if (!t->is_known_instance() &&
2159 !base_t->klass()->is_subtype_of(t->klass())) {
2160 return false; // bail out
2161 }
2162 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2163 // Do NOT remove the next line: ensure a new alias index is allocated
2164 // for the instance type. Note: C++ will not remove it since the call
2165 // has side effect.
2166 int alias_idx = _compile->get_alias_index(tinst);
2167 igvn->set_type(addp, tinst);
2168 // record the allocation in the node map
2169 set_map(addp, get_map(base->_idx));
2170 // Set addp's Base and Address to 'base'.
2171 Node *abase = addp->in(AddPNode::Base);
2172 Node *adr = addp->in(AddPNode::Address);
2173 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2174 adr->in(0)->_idx == (uint)inst_id) {
2175 // Skip AddP cases #3 and #5.
2176 } else {
2177 assert(!abase->is_top(), "sanity"); // AddP case #3
2178 if (abase != base) {
2179 igvn->hash_delete(addp);
2180 addp->set_req(AddPNode::Base, base);
2181 if (abase == adr) {
2182 addp->set_req(AddPNode::Address, base);
2183 } else {
2184 // AddP case #4 (adr is array's element offset AddP node)
2185 #ifdef ASSERT
2186 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2187 assert(adr->is_AddP() && atype != NULL &&
2188 atype->instance_id() == inst_id, "array's element offset should be processed first");
2189 #endif
2190 }
2191 igvn->hash_insert(addp);
2192 }
2193 }
2194 // Put on IGVN worklist since at least addp's type was changed above.
2195 record_for_optimizer(addp);
2196 return true;
2197 }
2198
2199 //
2200 // Create a new version of orig_phi if necessary. Returns either the newly
2201 // created phi or an existing phi. Sets create_new to indicate whether a new
2202 // phi was created. Cache the last newly created phi in the node map.
2203 //
2204 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2205 Compile *C = _compile;
2206 PhaseGVN* igvn = _igvn;
2207 new_created = false;
2208 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2209 // nothing to do if orig_phi is bottom memory or matches alias_idx
2210 if (phi_alias_idx == alias_idx) {
2211 return orig_phi;
2212 }
2213 // Have we recently created a Phi for this alias index?
2214 PhiNode *result = get_map_phi(orig_phi->_idx);
2215 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2216 return result;
2217 }
2218 // Previous check may fail when the same wide memory Phi was split into Phis
2219 // for different memory slices. Search all Phis for this region.
2220 if (result != NULL) {
2221 Node* region = orig_phi->in(0);
2222 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2223 Node* phi = region->fast_out(i);
2224 if (phi->is_Phi() &&
2225 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2226 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2227 return phi->as_Phi();
2228 }
2229 }
2230 }
2231 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
2232 if (C->do_escape_analysis() == true && !C->failing()) {
2233 // Retry compilation without escape analysis.
2234 // If this is the first failure, the sentinel string will "stick"
2235 // to the Compile object, and the C2Compiler will see it and retry.
2236 C->record_failure(C2Compiler::retry_no_escape_analysis());
2237 }
2238 return NULL;
2239 }
2240 orig_phi_worklist.append_if_missing(orig_phi);
2241 const TypePtr *atype = C->get_adr_type(alias_idx);
2242 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2243 C->copy_node_notes_to(result, orig_phi);
2244 igvn->set_type(result, result->bottom_type());
2245 record_for_optimizer(result);
2246 set_map(orig_phi, result);
2247 new_created = true;
2248 return result;
2249 }
2250
2251 //
2252 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2253 // specified alias index.
2254 //
2255 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2256 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2257 Compile *C = _compile;
2258 PhaseGVN* igvn = _igvn;
2259 bool new_phi_created;
2260 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2261 if (!new_phi_created) {
2262 return result;
2263 }
2264 GrowableArray<PhiNode *> phi_list;
2265 GrowableArray<uint> cur_input;
2266 PhiNode *phi = orig_phi;
2267 uint idx = 1;
2268 bool finished = false;
2269 while(!finished) {
2270 while (idx < phi->req()) {
2271 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2272 if (mem != NULL && mem->is_Phi()) {
2273 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2274 if (new_phi_created) {
2275 // found an phi for which we created a new split, push current one on worklist and begin
2276 // processing new one
2277 phi_list.push(phi);
2278 cur_input.push(idx);
2279 phi = mem->as_Phi();
2280 result = newphi;
2281 idx = 1;
2282 continue;
2283 } else {
2284 mem = newphi;
2285 }
2286 }
2287 if (C->failing()) {
2288 return NULL;
2289 }
2290 result->set_req(idx++, mem);
2291 }
2292 #ifdef ASSERT
2293 // verify that the new Phi has an input for each input of the original
2294 assert( phi->req() == result->req(), "must have same number of inputs.");
2295 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2296 #endif
2297 // Check if all new phi's inputs have specified alias index.
2298 // Otherwise use old phi.
2299 for (uint i = 1; i < phi->req(); i++) {
2300 Node* in = result->in(i);
2301 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2302 }
2303 // we have finished processing a Phi, see if there are any more to do
2304 finished = (phi_list.length() == 0 );
2305 if (!finished) {
2306 phi = phi_list.pop();
2307 idx = cur_input.pop();
2308 PhiNode *prev_result = get_map_phi(phi->_idx);
2309 prev_result->set_req(idx++, result);
2310 result = prev_result;
2311 }
2312 }
2313 return result;
2314 }
2315
2316 //
2317 // The next methods are derived from methods in MemNode.
2318 //
2319 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2320 Node *mem = mmem;
2321 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2322 // means an array I have not precisely typed yet. Do not do any
2323 // alias stuff with it any time soon.
2324 if (toop->base() != Type::AnyPtr &&
2325 !(toop->klass() != NULL &&
2326 toop->klass()->is_java_lang_Object() &&
2327 toop->offset() == Type::OffsetBot)) {
2328 mem = mmem->memory_at(alias_idx);
2329 // Update input if it is progress over what we have now
2330 }
2331 return mem;
2332 }
2333
2334 //
2335 // Move memory users to their memory slices.
2336 //
2337 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2338 Compile* C = _compile;
2339 PhaseGVN* igvn = _igvn;
2340 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2341 assert(tp != NULL, "ptr type");
2342 int alias_idx = C->get_alias_index(tp);
2343 int general_idx = C->get_general_index(alias_idx);
2344
2345 // Move users first
2346 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2347 Node* use = n->fast_out(i);
2348 if (use->is_MergeMem()) {
2349 MergeMemNode* mmem = use->as_MergeMem();
2350 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2351 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2352 continue; // Nothing to do
2353 }
2354 // Replace previous general reference to mem node.
2355 uint orig_uniq = C->unique();
2356 Node* m = find_inst_mem(n, general_idx, orig_phis);
2357 assert(orig_uniq == C->unique(), "no new nodes");
2358 mmem->set_memory_at(general_idx, m);
2359 --imax;
2360 --i;
2361 } else if (use->is_MemBar()) {
2362 assert(!use->is_Initialize(), "initializing stores should not be moved");
2363 if (use->req() > MemBarNode::Precedent &&
2364 use->in(MemBarNode::Precedent) == n) {
2365 // Don't move related membars.
2366 record_for_optimizer(use);
2367 continue;
2368 }
2369 tp = use->as_MemBar()->adr_type()->isa_ptr();
2370 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2371 alias_idx == general_idx) {
2372 continue; // Nothing to do
2373 }
2374 // Move to general memory slice.
2375 uint orig_uniq = C->unique();
2376 Node* m = find_inst_mem(n, general_idx, orig_phis);
2377 assert(orig_uniq == C->unique(), "no new nodes");
2378 igvn->hash_delete(use);
2379 imax -= use->replace_edge(n, m);
2380 igvn->hash_insert(use);
2381 record_for_optimizer(use);
2382 --i;
2383 #ifdef ASSERT
2384 } else if (use->is_Mem()) {
2385 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2386 // Don't move related cardmark.
2387 continue;
2388 }
2389 // Memory nodes should have new memory input.
2390 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2391 assert(tp != NULL, "ptr type");
2392 int idx = C->get_alias_index(tp);
2393 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2394 "Following memory nodes should have new memory input or be on the same memory slice");
2395 } else if (use->is_Phi()) {
2396 // Phi nodes should be split and moved already.
2397 tp = use->as_Phi()->adr_type()->isa_ptr();
2398 assert(tp != NULL, "ptr type");
2399 int idx = C->get_alias_index(tp);
2400 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2401 } else {
2402 use->dump();
2403 assert(false, "should not be here");
2404 #endif
2405 }
2406 }
2407 }
2408
2409 //
2410 // Search memory chain of "mem" to find a MemNode whose address
2411 // is the specified alias index.
2412 //
2413 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2414 if (orig_mem == NULL)
2415 return orig_mem;
2416 Compile* C = _compile;
2417 PhaseGVN* igvn = _igvn;
2418 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2419 bool is_instance = (toop != NULL) && toop->is_known_instance();
2420 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2421 Node *prev = NULL;
2422 Node *result = orig_mem;
2423 while (prev != result) {
2424 prev = result;
2425 if (result == start_mem)
2426 break; // hit one of our sentinels
2427 if (result->is_Mem()) {
2428 const Type *at = igvn->type(result->in(MemNode::Address));
2429 if (at == Type::TOP)
2430 break; // Dead
2431 assert (at->isa_ptr() != NULL, "pointer type required.");
2432 int idx = C->get_alias_index(at->is_ptr());
2433 if (idx == alias_idx)
2434 break; // Found
2435 if (!is_instance && (at->isa_oopptr() == NULL ||
2436 !at->is_oopptr()->is_known_instance())) {
2437 break; // Do not skip store to general memory slice.
2438 }
2439 result = result->in(MemNode::Memory);
2440 }
2441 if (!is_instance)
2442 continue; // don't search further for non-instance types
2443 // skip over a call which does not affect this memory slice
2444 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2445 Node *proj_in = result->in(0);
2446 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2447 break; // hit one of our sentinels
2448 } else if (proj_in->is_Call()) {
2449 CallNode *call = proj_in->as_Call();
2450 if (!call->may_modify(toop, igvn)) {
2451 result = call->in(TypeFunc::Memory);
2452 }
2453 } else if (proj_in->is_Initialize()) {
2454 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2455 // Stop if this is the initialization for the object instance which
2456 // which contains this memory slice, otherwise skip over it.
2457 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2458 result = proj_in->in(TypeFunc::Memory);
2459 }
2460 } else if (proj_in->is_MemBar()) {
2461 result = proj_in->in(TypeFunc::Memory);
2462 }
2463 } else if (result->is_MergeMem()) {
2464 MergeMemNode *mmem = result->as_MergeMem();
2465 result = step_through_mergemem(mmem, alias_idx, toop);
2466 if (result == mmem->base_memory()) {
2467 // Didn't find instance memory, search through general slice recursively.
2468 result = mmem->memory_at(C->get_general_index(alias_idx));
2469 result = find_inst_mem(result, alias_idx, orig_phis);
2470 if (C->failing()) {
2471 return NULL;
2472 }
2473 mmem->set_memory_at(alias_idx, result);
2474 }
2475 } else if (result->is_Phi() &&
2476 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2477 Node *un = result->as_Phi()->unique_input(igvn);
2478 if (un != NULL) {
2479 orig_phis.append_if_missing(result->as_Phi());
2480 result = un;
2481 } else {
2482 break;
2483 }
2484 } else if (result->is_ClearArray()) {
2485 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2486 // Can not bypass initialization of the instance
2487 // we are looking for.
2488 break;
2489 }
2490 // Otherwise skip it (the call updated 'result' value).
2491 } else if (result->Opcode() == Op_SCMemProj) {
2492 assert(result->in(0)->is_LoadStore(), "sanity");
2493 const Type *at = igvn->type(result->in(0)->in(MemNode::Address));
2494 if (at != Type::TOP) {
2495 assert (at->isa_ptr() != NULL, "pointer type required.");
2496 int idx = C->get_alias_index(at->is_ptr());
2497 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2498 break;
2499 }
2500 result = result->in(0)->in(MemNode::Memory);
2501 }
2502 }
2503 if (result->is_Phi()) {
2504 PhiNode *mphi = result->as_Phi();
2505 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2506 const TypePtr *t = mphi->adr_type();
2507 if (!is_instance) {
2508 // Push all non-instance Phis on the orig_phis worklist to update inputs
2509 // during Phase 4 if needed.
2510 orig_phis.append_if_missing(mphi);
2511 } else if (C->get_alias_index(t) != alias_idx) {
2512 // Create a new Phi with the specified alias index type.
2513 result = split_memory_phi(mphi, alias_idx, orig_phis);
2514 }
2515 }
2516 // the result is either MemNode, PhiNode, InitializeNode.
2517 return result;
2518 }
2519
2520 //
2521 // Convert the types of unescaped object to instance types where possible,
2522 // propagate the new type information through the graph, and update memory
2523 // edges and MergeMem inputs to reflect the new type.
2524 //
2525 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2526 // The processing is done in 4 phases:
2527 //
2528 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2529 // types for the CheckCastPP for allocations where possible.
2530 // Propagate the the new types through users as follows:
2531 // casts and Phi: push users on alloc_worklist
2532 // AddP: cast Base and Address inputs to the instance type
2533 // push any AddP users on alloc_worklist and push any memnode
2534 // users onto memnode_worklist.
2535 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2536 // search the Memory chain for a store with the appropriate type
2537 // address type. If a Phi is found, create a new version with
2538 // the appropriate memory slices from each of the Phi inputs.
2539 // For stores, process the users as follows:
2540 // MemNode: push on memnode_worklist
2541 // MergeMem: push on mergemem_worklist
2542 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2543 // moving the first node encountered of each instance type to the
2544 // the input corresponding to its alias index.
2545 // appropriate memory slice.
2546 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2547 //
2548 // In the following example, the CheckCastPP nodes are the cast of allocation
2549 // results and the allocation of node 29 is unescaped and eligible to be an
2550 // instance type.
2551 //
2552 // We start with:
2553 //
2554 // 7 Parm #memory
2555 // 10 ConI "12"
2556 // 19 CheckCastPP "Foo"
2557 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2558 // 29 CheckCastPP "Foo"
2559 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2560 //
2561 // 40 StoreP 25 7 20 ... alias_index=4
2562 // 50 StoreP 35 40 30 ... alias_index=4
2563 // 60 StoreP 45 50 20 ... alias_index=4
2564 // 70 LoadP _ 60 30 ... alias_index=4
2565 // 80 Phi 75 50 60 Memory alias_index=4
2566 // 90 LoadP _ 80 30 ... alias_index=4
2567 // 100 LoadP _ 80 20 ... alias_index=4
2568 //
2569 //
2570 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2571 // and creating a new alias index for node 30. This gives:
2572 //
2573 // 7 Parm #memory
2574 // 10 ConI "12"
2575 // 19 CheckCastPP "Foo"
2576 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2577 // 29 CheckCastPP "Foo" iid=24
2578 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2579 //
2580 // 40 StoreP 25 7 20 ... alias_index=4
2581 // 50 StoreP 35 40 30 ... alias_index=6
2582 // 60 StoreP 45 50 20 ... alias_index=4
2583 // 70 LoadP _ 60 30 ... alias_index=6
2584 // 80 Phi 75 50 60 Memory alias_index=4
2585 // 90 LoadP _ 80 30 ... alias_index=6
2586 // 100 LoadP _ 80 20 ... alias_index=4
2587 //
2588 // In phase 2, new memory inputs are computed for the loads and stores,
2589 // And a new version of the phi is created. In phase 4, the inputs to
2590 // node 80 are updated and then the memory nodes are updated with the
2591 // values computed in phase 2. This results in:
2592 //
2593 // 7 Parm #memory
2594 // 10 ConI "12"
2595 // 19 CheckCastPP "Foo"
2596 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2597 // 29 CheckCastPP "Foo" iid=24
2598 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2599 //
2600 // 40 StoreP 25 7 20 ... alias_index=4
2601 // 50 StoreP 35 7 30 ... alias_index=6
2602 // 60 StoreP 45 40 20 ... alias_index=4
2603 // 70 LoadP _ 50 30 ... alias_index=6
2604 // 80 Phi 75 40 60 Memory alias_index=4
2605 // 120 Phi 75 50 50 Memory alias_index=6
2606 // 90 LoadP _ 120 30 ... alias_index=6
2607 // 100 LoadP _ 80 20 ... alias_index=4
2608 //
2609 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2610 GrowableArray<Node *> memnode_worklist;
2611 GrowableArray<PhiNode *> orig_phis;
2612 PhaseIterGVN *igvn = _igvn;
2613 uint new_index_start = (uint) _compile->num_alias_types();
2614 Arena* arena = Thread::current()->resource_area();
2615 VectorSet visited(arena);
2616 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2617 uint unique_old = _compile->unique();
2618
2619 // Phase 1: Process possible allocations from alloc_worklist.
2620 // Create instance types for the CheckCastPP for allocations where possible.
2621 //
2622 // (Note: don't forget to change the order of the second AddP node on
2623 // the alloc_worklist if the order of the worklist processing is changed,
2624 // see the comment in find_second_addp().)
2625 //
2626 while (alloc_worklist.length() != 0) {
2627 Node *n = alloc_worklist.pop();
2628 uint ni = n->_idx;
2629 if (n->is_Call()) {
2630 CallNode *alloc = n->as_Call();
2631 // copy escape information to call node
2632 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2633 PointsToNode::EscapeState es = ptn->escape_state();
2634 // We have an allocation or call which returns a Java object,
2635 // see if it is unescaped.
2636 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2637 continue;
2638 // Find CheckCastPP for the allocate or for the return value of a call
2639 n = alloc->result_cast();
2640 if (n == NULL) { // No uses except Initialize node
2641 if (alloc->is_Allocate()) {
2642 // Set the scalar_replaceable flag for allocation
2643 // so it could be eliminated if it has no uses.
2644 alloc->as_Allocate()->_is_scalar_replaceable = true;
2645 }
2646 continue;
2647 }
2648 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2649 assert(!alloc->is_Allocate(), "allocation should have unique type");
2650 continue;
2651 }
2652
2653 // The inline code for Object.clone() casts the allocation result to
2654 // java.lang.Object and then to the actual type of the allocated
2655 // object. Detect this case and use the second cast.
2656 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2657 // the allocation result is cast to java.lang.Object and then
2658 // to the actual Array type.
2659 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2660 && (alloc->is_AllocateArray() ||
2661 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2662 Node *cast2 = NULL;
2663 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2664 Node *use = n->fast_out(i);
2665 if (use->is_CheckCastPP()) {
2666 cast2 = use;
2667 break;
2668 }
2669 }
2670 if (cast2 != NULL) {
2671 n = cast2;
2672 } else {
2673 // Non-scalar replaceable if the allocation type is unknown statically
2674 // (reflection allocation), the object can't be restored during
2675 // deoptimization without precise type.
2676 continue;
2677 }
2678 }
2679 if (alloc->is_Allocate()) {
2680 // Set the scalar_replaceable flag for allocation
2681 // so it could be eliminated.
2682 alloc->as_Allocate()->_is_scalar_replaceable = true;
2683 }
2684 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2685 // in order for an object to be scalar-replaceable, it must be:
2686 // - a direct allocation (not a call returning an object)
2687 // - non-escaping
2688 // - eligible to be a unique type
2689 // - not determined to be ineligible by escape analysis
2690 set_map(alloc, n);
2691 set_map(n, alloc);
2692 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2693 if (t == NULL)
2694 continue; // not a TypeOopPtr
2695 const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
2696 igvn->hash_delete(n);
2697 igvn->set_type(n, tinst);
2698 n->raise_bottom_type(tinst);
2699 igvn->hash_insert(n);
2700 record_for_optimizer(n);
2701 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2702
2703 // First, put on the worklist all Field edges from Connection Graph
2704 // which is more accurate then putting immediate users from Ideal Graph.
2705 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2706 PointsToNode* tgt = e.get();
2707 Node* use = tgt->ideal_node();
2708 assert(tgt->is_Field() && use->is_AddP(),
2709 "only AddP nodes are Field edges in CG");
2710 if (use->outcnt() > 0) { // Don't process dead nodes
2711 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2712 if (addp2 != NULL) {
2713 assert(alloc->is_AllocateArray(),"array allocation was expected");
2714 alloc_worklist.append_if_missing(addp2);
2715 }
2716 alloc_worklist.append_if_missing(use);
2717 }
2718 }
2719
2720 // An allocation may have an Initialize which has raw stores. Scan
2721 // the users of the raw allocation result and push AddP users
2722 // on alloc_worklist.
2723 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2724 assert (raw_result != NULL, "must have an allocation result");
2725 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2726 Node *use = raw_result->fast_out(i);
2727 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2728 Node* addp2 = find_second_addp(use, raw_result);
2729 if (addp2 != NULL) {
2730 assert(alloc->is_AllocateArray(),"array allocation was expected");
2731 alloc_worklist.append_if_missing(addp2);
2732 }
2733 alloc_worklist.append_if_missing(use);
2734 } else if (use->is_MemBar()) {
2735 memnode_worklist.append_if_missing(use);
2736 }
2737 }
2738 }
2739 } else if (n->is_AddP()) {
2740 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2741 if (jobj == NULL || jobj == phantom_obj) {
2742 #ifdef ASSERT
2743 ptnode_adr(get_addp_base(n)->_idx)->dump();
2744 ptnode_adr(n->_idx)->dump();
2745 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2746 #endif
2747 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2748 return;
2749 }
2750 Node *base = get_map(jobj->idx()); // CheckCastPP node
2751 if (!split_AddP(n, base)) continue; // wrong type from dead path
2752 } else if (n->is_Phi() ||
2753 n->is_CheckCastPP() ||
2754 n->is_EncodeP() ||
2755 n->is_DecodeN() ||
2756 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2757 if (visited.test_set(n->_idx)) {
2758 assert(n->is_Phi(), "loops only through Phi's");
2759 continue; // already processed
2760 }
2761 JavaObjectNode* jobj = unique_java_object(n);
2762 if (jobj == NULL || jobj == phantom_obj) {
2763 #ifdef ASSERT
2764 ptnode_adr(n->_idx)->dump();
2765 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2766 #endif
2767 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2768 return;
2769 } else {
2770 Node *val = get_map(jobj->idx()); // CheckCastPP node
2771 TypeNode *tn = n->as_Type();
2772 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2773 assert(tinst != NULL && tinst->is_known_instance() &&
2774 tinst->instance_id() == jobj->idx() , "instance type expected.");
2775
2776 const Type *tn_type = igvn->type(tn);
2777 const TypeOopPtr *tn_t;
2778 if (tn_type->isa_narrowoop()) {
2779 tn_t = tn_type->make_ptr()->isa_oopptr();
2780 } else {
2781 tn_t = tn_type->isa_oopptr();
2782 }
2783 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2784 if (tn_type->isa_narrowoop()) {
2785 tn_type = tinst->make_narrowoop();
2786 } else {
2787 tn_type = tinst;
2788 }
2789 igvn->hash_delete(tn);
2790 igvn->set_type(tn, tn_type);
2791 tn->set_type(tn_type);
2792 igvn->hash_insert(tn);
2793 record_for_optimizer(n);
2794 } else {
2795 assert(tn_type == TypePtr::NULL_PTR ||
2796 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2797 "unexpected type");
2798 continue; // Skip dead path with different type
2799 }
2800 }
2801 } else {
2802 debug_only(n->dump();)
2803 assert(false, "EA: unexpected node");
2804 continue;
2805 }
2806 // push allocation's users on appropriate worklist
2807 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2808 Node *use = n->fast_out(i);
2809 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2810 // Load/store to instance's field
2811 memnode_worklist.append_if_missing(use);
2812 } else if (use->is_MemBar()) {
2813 memnode_worklist.append_if_missing(use);
2814 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2815 Node* addp2 = find_second_addp(use, n);
2816 if (addp2 != NULL) {
2817 alloc_worklist.append_if_missing(addp2);
2818 }
2819 alloc_worklist.append_if_missing(use);
2820 } else if (use->is_Phi() ||
2821 use->is_CheckCastPP() ||
2822 use->is_EncodeP() ||
2823 use->is_DecodeN() ||
2824 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
2825 alloc_worklist.append_if_missing(use);
2826 #ifdef ASSERT
2827 } else if (use->is_Mem()) {
2828 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
2829 } else if (use->is_MergeMem()) {
2830 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2831 } else if (use->is_SafePoint()) {
2832 // Look for MergeMem nodes for calls which reference unique allocation
2833 // (through CheckCastPP nodes) even for debug info.
2834 Node* m = use->in(TypeFunc::Memory);
2835 if (m->is_MergeMem()) {
2836 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2837 }
2838 } else {
2839 uint op = use->Opcode();
2840 if (!(op == Op_CmpP || op == Op_Conv2B ||
2841 op == Op_CastP2X || op == Op_StoreCM ||
2842 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
2843 op == Op_StrEquals || op == Op_StrIndexOf)) {
2844 n->dump();
2845 use->dump();
2846 assert(false, "EA: missing allocation reference path");
2847 }
2848 #endif
2849 }
2850 }
2851
2852 }
2853 // New alias types were created in split_AddP().
2854 uint new_index_end = (uint) _compile->num_alias_types();
2855 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
2856
2857 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2858 // compute new values for Memory inputs (the Memory inputs are not
2859 // actually updated until phase 4.)
2860 if (memnode_worklist.length() == 0)
2861 return; // nothing to do
2862 while (memnode_worklist.length() != 0) {
2863 Node *n = memnode_worklist.pop();
2864 if (visited.test_set(n->_idx))
2865 continue;
2866 if (n->is_Phi() || n->is_ClearArray()) {
2867 // we don't need to do anything, but the users must be pushed
2868 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
2869 // we don't need to do anything, but the users must be pushed
2870 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
2871 if (n == NULL)
2872 continue;
2873 } else {
2874 assert(n->is_Mem(), "memory node required.");
2875 Node *addr = n->in(MemNode::Address);
2876 const Type *addr_t = igvn->type(addr);
2877 if (addr_t == Type::TOP)
2878 continue;
2879 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
2880 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
2881 assert ((uint)alias_idx < new_index_end, "wrong alias index");
2882 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
2883 if (_compile->failing()) {
2884 return;
2885 }
2886 if (mem != n->in(MemNode::Memory)) {
2887 // We delay the memory edge update since we need old one in
2888 // MergeMem code below when instances memory slices are separated.
2889 set_map(n, mem);
2890 }
2891 if (n->is_Load()) {
2892 continue; // don't push users
2893 } else if (n->is_LoadStore()) {
2894 // get the memory projection
2895 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2896 Node *use = n->fast_out(i);
2897 if (use->Opcode() == Op_SCMemProj) {
2898 n = use;
2899 break;
2900 }
2901 }
2902 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
2903 }
2904 }
2905 // push user on appropriate worklist
2906 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2907 Node *use = n->fast_out(i);
2908 if (use->is_Phi() || use->is_ClearArray()) {
2909 memnode_worklist.append_if_missing(use);
2910 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
2911 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
2912 continue;
2913 memnode_worklist.append_if_missing(use);
2914 } else if (use->is_MemBar()) {
2915 memnode_worklist.append_if_missing(use);
2916 #ifdef ASSERT
2917 } else if(use->is_Mem()) {
2918 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
2919 } else if (use->is_MergeMem()) {
2920 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
2921 } else {
2922 uint op = use->Opcode();
2923 if (!(op == Op_StoreCM ||
2924 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
2925 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
2926 op == Op_AryEq || op == Op_StrComp ||
2927 op == Op_StrEquals || op == Op_StrIndexOf)) {
2928 n->dump();
2929 use->dump();
2930 assert(false, "EA: missing memory path");
2931 }
2932 #endif
2933 }
2934 }
2935 }
2936
2937 // Phase 3: Process MergeMem nodes from mergemem_worklist.
2938 // Walk each memory slice moving the first node encountered of each
2939 // instance type to the the input corresponding to its alias index.
2940 uint length = _mergemem_worklist.length();
2941 for( uint next = 0; next < length; ++next ) {
2942 MergeMemNode* nmm = _mergemem_worklist.at(next);
2943 assert(!visited.test_set(nmm->_idx), "should not be visited before");
2944 // Note: we don't want to use MergeMemStream here because we only want to
2945 // scan inputs which exist at the start, not ones we add during processing.
2946 // Note 2: MergeMem may already contains instance memory slices added
2947 // during find_inst_mem() call when memory nodes were processed above.
2948 igvn->hash_delete(nmm);
2949 uint nslices = nmm->req();
2950 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
2951 Node* mem = nmm->in(i);
2952 Node* cur = NULL;
2953 if (mem == NULL || mem->is_top())
2954 continue;
2955 // First, update mergemem by moving memory nodes to corresponding slices
2956 // if their type became more precise since this mergemem was created.
2957 while (mem->is_Mem()) {
2958 const Type *at = igvn->type(mem->in(MemNode::Address));
2959 if (at != Type::TOP) {
2960 assert (at->isa_ptr() != NULL, "pointer type required.");
2961 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
2962 if (idx == i) {
2963 if (cur == NULL)
2964 cur = mem;
2965 } else {
2966 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
2967 nmm->set_memory_at(idx, mem);
2968 }
2969 }
2970 }
2971 mem = mem->in(MemNode::Memory);
2972 }
2973 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
2974 // Find any instance of the current type if we haven't encountered
2975 // already a memory slice of the instance along the memory chain.
2976 for (uint ni = new_index_start; ni < new_index_end; ni++) {
2977 if((uint)_compile->get_general_index(ni) == i) {
2978 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
2979 if (nmm->is_empty_memory(m)) {
2980 Node* result = find_inst_mem(mem, ni, orig_phis);
2981 if (_compile->failing()) {
2982 return;
2983 }
2984 nmm->set_memory_at(ni, result);
2985 }
2986 }
2987 }
2988 }
2989 // Find the rest of instances values
2990 for (uint ni = new_index_start; ni < new_index_end; ni++) {
2991 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
2992 Node* result = step_through_mergemem(nmm, ni, tinst);
2993 if (result == nmm->base_memory()) {
2994 // Didn't find instance memory, search through general slice recursively.
2995 result = nmm->memory_at(_compile->get_general_index(ni));
2996 result = find_inst_mem(result, ni, orig_phis);
2997 if (_compile->failing()) {
2998 return;
2999 }
3000 nmm->set_memory_at(ni, result);
3001 }
3002 }
3003 igvn->hash_insert(nmm);
3004 record_for_optimizer(nmm);
3005 }
3006
3007 // Phase 4: Update the inputs of non-instance memory Phis and
3008 // the Memory input of memnodes
3009 // First update the inputs of any non-instance Phi's from
3010 // which we split out an instance Phi. Note we don't have
3011 // to recursively process Phi's encounted on the input memory
3012 // chains as is done in split_memory_phi() since they will
3013 // also be processed here.
3014 for (int j = 0; j < orig_phis.length(); j++) {
3015 PhiNode *phi = orig_phis.at(j);
3016 int alias_idx = _compile->get_alias_index(phi->adr_type());
3017 igvn->hash_delete(phi);
3018 for (uint i = 1; i < phi->req(); i++) {
3019 Node *mem = phi->in(i);
3020 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3021 if (_compile->failing()) {
3022 return;
3023 }
3024 if (mem != new_mem) {
3025 phi->set_req(i, new_mem);
3026 }
3027 }
3028 igvn->hash_insert(phi);
3029 record_for_optimizer(phi);
3030 }
3031
3032 // Update the memory inputs of MemNodes with the value we computed
3033 // in Phase 2 and move stores memory users to corresponding memory slices.
3034 // Disable memory split verification code until the fix for 6984348.
3035 // Currently it produces false negative results since it does not cover all cases.
3036 #if 0 // ifdef ASSERT
3037 visited.Reset();
3038 Node_Stack old_mems(arena, _compile->unique() >> 2);
3039 #endif
3040 for (uint i = 0; i < ideal_nodes.size(); i++) {
3041 Node* n = ideal_nodes.at(i);
3042 Node* nmem = get_map(n->_idx);
3043 assert(nmem != NULL, "sanity");
3044 if (n->is_Mem()) {
3045 #if 0 // ifdef ASSERT
3046 Node* old_mem = n->in(MemNode::Memory);
3047 if (!visited.test_set(old_mem->_idx)) {
3048 old_mems.push(old_mem, old_mem->outcnt());
3049 }
3050 #endif
3051 assert(n->in(MemNode::Memory) != nmem, "sanity");
3052 if (!n->is_Load()) {
3053 // Move memory users of a store first.
3054 move_inst_mem(n, orig_phis);
3055 }
3056 // Now update memory input
3057 igvn->hash_delete(n);
3058 n->set_req(MemNode::Memory, nmem);
3059 igvn->hash_insert(n);
3060 record_for_optimizer(n);
3061 } else {
3062 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3063 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3064 }
3065 }
3066 #if 0 // ifdef ASSERT
3067 // Verify that memory was split correctly
3068 while (old_mems.is_nonempty()) {
3069 Node* old_mem = old_mems.node();
3070 uint old_cnt = old_mems.index();
3071 old_mems.pop();
3072 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3073 }
3074 #endif
3075 }
3076
3077 #ifndef PRODUCT
3078 static const char *node_type_names[] = {
3079 "UnknownType",
3080 "JavaObject",
3081 "LocalVar",
3082 "Field",
3083 "Arraycopy"
3084 };
3085
3086 static const char *esc_names[] = {
3087 "UnknownEscape",
3088 "NoEscape",
3089 "ArgEscape",
3090 "GlobalEscape"
3091 };
3092
3093 void PointsToNode::dump(bool print_state) const {
3094 NodeType nt = node_type();
3095 tty->print("%s ", node_type_names[(int) nt]);
3096 if (print_state) {
3097 EscapeState es = escape_state();
3098 EscapeState fields_es = fields_escape_state();
3099 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3100 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3101 tty->print("NSR");
3102 }
3103 if (is_Field()) {
3104 FieldNode* f = (FieldNode*)this;
3105 tty->print("(");
3106 for (BaseIterator i(f); i.has_next(); i.next()) {
3107 PointsToNode* b = i.get();
3108 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3109 }
3110 tty->print(" )");
3111 }
3112 tty->print("[");
3113 for (EdgeIterator i(this); i.has_next(); i.next()) {
3114 PointsToNode* e = i.get();
3115 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3116 }
3117 tty->print(" [");
3118 for (UseIterator i(this); i.has_next(); i.next()) {
3119 PointsToNode* u = i.get();
3120 bool is_base = false;
3121 if (PointsToNode::is_base_use(u)) {
3122 is_base = true;
3123 u = PointsToNode::get_use_node(u)->as_Field();
3124 }
3125 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3126 }
3127 tty->print(" ]] ");
3128 if (_node == NULL)
3129 tty->print_cr("<null>");
3130 else
3131 _node->dump();
3132 }
3133
3134 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3135 bool first = true;
3136 int ptnodes_length = ptnodes_worklist.length();
3137 for (int i = 0; i < ptnodes_length; i++) {
3138 PointsToNode *ptn = ptnodes_worklist.at(i);
3139 if (ptn == NULL || !ptn->is_JavaObject())
3140 continue;
3141 PointsToNode::EscapeState es = ptn->escape_state();
3142 if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3143 if (first) {
3144 tty->cr();
3145 tty->print("======== Connection graph for ");
3146 _compile->method()->print_short_name();
3147 tty->cr();
3148 first = false;
3149 }
3150 ptn->dump();
3151 // Print all locals and fields which reference this allocation
3152 for (UseIterator j(ptn); j.has_next(); j.next()) {
3153 PointsToNode* use = j.get();
3154 if (use->is_LocalVar()) {
3155 use->dump(Verbose);
3156 } else if (Verbose) {
3157 use->dump();
3158 }
3159 }
3160 tty->cr();
3161 }
3162 }
3163 }
3164 #endif