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