1 /*
2 * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "opto/c2compiler.hpp"
31 #include "opto/callnode.hpp"
32 #include "opto/cfgnode.hpp"
33 #include "opto/compile.hpp"
34 #include "opto/escape.hpp"
35 #include "opto/phaseX.hpp"
36 #include "opto/movenode.hpp"
37 #include "opto/rootnode.hpp"
38
39 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
40 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
41 _collecting(true),
42 _verify(false),
43 _compile(C),
44 _igvn(igvn),
45 _node_map(C->comp_arena()) {
46 // Add unknown java object.
47 add_java_object(C->top(), PointsToNode::GlobalEscape);
48 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
49 // Add ConP(#NULL) and ConN(#NULL) nodes.
50 Node* oop_null = igvn->zerocon(T_OBJECT);
51 assert(oop_null->_idx < nodes_size(), "should be created already");
52 add_java_object(oop_null, PointsToNode::NoEscape);
53 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
54 if (UseCompressedOops) {
55 Node* noop_null = igvn->zerocon(T_NARROWOOP);
56 assert(noop_null->_idx < nodes_size(), "should be created already");
57 map_ideal_node(noop_null, null_obj);
58 }
59 _pcmp_neq = NULL; // Should be initialized
60 _pcmp_eq = NULL;
61 }
62
63 bool ConnectionGraph::has_candidates(Compile *C) {
64 // EA brings benefits only when the code has allocations and/or locks which
65 // are represented by ideal Macro nodes.
66 int cnt = C->macro_count();
67 for (int i = 0; i < cnt; i++) {
68 Node *n = C->macro_node(i);
69 if (n->is_Allocate())
70 return true;
71 if (n->is_Lock()) {
72 Node* obj = n->as_Lock()->obj_node()->uncast();
73 if (!(obj->is_Parm() || obj->is_Con()))
74 return true;
75 }
76 if (n->is_CallStaticJava() &&
77 n->as_CallStaticJava()->is_boxing_method()) {
78 return true;
79 }
80 }
81 return false;
82 }
83
84 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
85 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
86 ResourceMark rm;
87
88 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
89 // to create space for them in ConnectionGraph::_nodes[].
90 Node* oop_null = igvn->zerocon(T_OBJECT);
91 Node* noop_null = igvn->zerocon(T_NARROWOOP);
92 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
93 // Perform escape analysis
94 if (congraph->compute_escape()) {
95 // There are non escaping objects.
96 C->set_congraph(congraph);
97 }
98 // Cleanup.
99 if (oop_null->outcnt() == 0)
100 igvn->hash_delete(oop_null);
101 if (noop_null->outcnt() == 0)
102 igvn->hash_delete(noop_null);
103 }
104
105 bool ConnectionGraph::compute_escape() {
106 Compile* C = _compile;
107 PhaseGVN* igvn = _igvn;
108
109 // Worklists used by EA.
110 Unique_Node_List delayed_worklist;
111 GrowableArray<Node*> alloc_worklist;
112 GrowableArray<Node*> ptr_cmp_worklist;
113 GrowableArray<Node*> storestore_worklist;
114 GrowableArray<PointsToNode*> ptnodes_worklist;
115 GrowableArray<JavaObjectNode*> java_objects_worklist;
116 GrowableArray<JavaObjectNode*> non_escaped_worklist;
117 GrowableArray<FieldNode*> oop_fields_worklist;
118 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
119
120 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
121
122 // 1. Populate Connection Graph (CG) with PointsTo nodes.
123 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
124 // Initialize worklist
125 if (C->root() != NULL) {
126 ideal_nodes.push(C->root());
127 }
128 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
129 Node* n = ideal_nodes.at(next);
130 // Create PointsTo nodes and add them to Connection Graph. Called
131 // only once per ideal node since ideal_nodes is Unique_Node list.
132 add_node_to_connection_graph(n, &delayed_worklist);
133 PointsToNode* ptn = ptnode_adr(n->_idx);
134 if (ptn != NULL) {
135 ptnodes_worklist.append(ptn);
136 if (ptn->is_JavaObject()) {
137 java_objects_worklist.append(ptn->as_JavaObject());
138 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
139 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
140 // Only allocations and java static calls results are interesting.
141 non_escaped_worklist.append(ptn->as_JavaObject());
142 }
143 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
144 oop_fields_worklist.append(ptn->as_Field());
145 }
146 }
147 if (n->is_MergeMem()) {
148 // Collect all MergeMem nodes to add memory slices for
149 // scalar replaceable objects in split_unique_types().
150 _mergemem_worklist.append(n->as_MergeMem());
151 } else if (OptimizePtrCompare && n->is_Cmp() &&
152 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
153 // Collect compare pointers nodes.
154 ptr_cmp_worklist.append(n);
155 } else if (n->is_MemBarStoreStore()) {
156 // Collect all MemBarStoreStore nodes so that depending on the
157 // escape status of the associated Allocate node some of them
158 // may be eliminated.
159 storestore_worklist.append(n);
160 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
161 (n->req() > MemBarNode::Precedent)) {
162 record_for_optimizer(n);
163 #ifdef ASSERT
164 } else if (n->is_AddP()) {
165 // Collect address nodes for graph verification.
166 addp_worklist.append(n);
167 #endif
168 }
169 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
170 Node* m = n->fast_out(i); // Get user
171 ideal_nodes.push(m);
172 }
173 }
174 if (non_escaped_worklist.length() == 0) {
175 _collecting = false;
176 return false; // Nothing to do.
177 }
178 // Add final simple edges to graph.
179 while(delayed_worklist.size() > 0) {
180 Node* n = delayed_worklist.pop();
181 add_final_edges(n);
182 }
183 int ptnodes_length = ptnodes_worklist.length();
184
185 #ifdef ASSERT
186 if (VerifyConnectionGraph) {
187 // Verify that no new simple edges could be created and all
188 // local vars has edges.
189 _verify = true;
190 for (int next = 0; next < ptnodes_length; ++next) {
191 PointsToNode* ptn = ptnodes_worklist.at(next);
192 add_final_edges(ptn->ideal_node());
193 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
194 ptn->dump();
195 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
196 }
197 }
198 _verify = false;
199 }
200 #endif
201
202 // 2. Finish Graph construction by propagating references to all
203 // java objects through graph.
204 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
205 java_objects_worklist, oop_fields_worklist)) {
206 // All objects escaped or hit time or iterations limits.
207 _collecting = false;
208 return false;
209 }
210
211 // 3. Adjust scalar_replaceable state of nonescaping objects and push
212 // scalar replaceable allocations on alloc_worklist for processing
213 // in split_unique_types().
214 int non_escaped_length = non_escaped_worklist.length();
215 for (int next = 0; next < non_escaped_length; next++) {
216 JavaObjectNode* ptn = non_escaped_worklist.at(next);
217 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
218 Node* n = ptn->ideal_node();
219 if (n->is_Allocate()) {
220 n->as_Allocate()->_is_non_escaping = noescape;
221 }
222 if (n->is_CallStaticJava()) {
223 n->as_CallStaticJava()->_is_non_escaping = noescape;
224 }
225 if (noescape && ptn->scalar_replaceable()) {
226 adjust_scalar_replaceable_state(ptn);
227 if (ptn->scalar_replaceable()) {
228 alloc_worklist.append(ptn->ideal_node());
229 }
230 }
231 }
232
233 #ifdef ASSERT
234 if (VerifyConnectionGraph) {
235 // Verify that graph is complete - no new edges could be added or needed.
236 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
237 java_objects_worklist, addp_worklist);
238 }
239 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
240 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
241 null_obj->edge_count() == 0 &&
242 !null_obj->arraycopy_src() &&
243 !null_obj->arraycopy_dst(), "sanity");
244 #endif
245
246 _collecting = false;
247
248 } // TracePhase t3("connectionGraph")
249
250 // 4. Optimize ideal graph based on EA information.
251 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
252 if (has_non_escaping_obj) {
253 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
254 }
255
256 #ifndef PRODUCT
257 if (PrintEscapeAnalysis) {
258 dump(ptnodes_worklist); // Dump ConnectionGraph
259 }
260 #endif
261
262 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
263 #ifdef ASSERT
264 if (VerifyConnectionGraph) {
265 int alloc_length = alloc_worklist.length();
266 for (int next = 0; next < alloc_length; ++next) {
267 Node* n = alloc_worklist.at(next);
268 PointsToNode* ptn = ptnode_adr(n->_idx);
269 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
270 }
271 }
272 #endif
273
274 // 5. Separate memory graph for scalar replaceable allcations.
275 if (has_scalar_replaceable_candidates &&
276 C->AliasLevel() >= 3 && EliminateAllocations) {
277 // Now use the escape information to create unique types for
278 // scalar replaceable objects.
279 split_unique_types(alloc_worklist);
280 if (C->failing()) return false;
281 C->print_method(PHASE_AFTER_EA, 2);
282
283 #ifdef ASSERT
284 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
285 tty->print("=== No allocations eliminated for ");
286 C->method()->print_short_name();
287 if(!EliminateAllocations) {
288 tty->print(" since EliminateAllocations is off ===");
289 } else if(!has_scalar_replaceable_candidates) {
290 tty->print(" since there are no scalar replaceable candidates ===");
291 } else if(C->AliasLevel() < 3) {
292 tty->print(" since AliasLevel < 3 ===");
293 }
294 tty->cr();
295 #endif
296 }
297 return has_non_escaping_obj;
298 }
299
300 // Utility function for nodes that load an object
301 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
302 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
303 // ThreadLocal has RawPtr type.
304 const Type* t = _igvn->type(n);
305 if (t->make_ptr() != NULL) {
306 Node* adr = n->in(MemNode::Address);
307 #ifdef ASSERT
308 if (!adr->is_AddP()) {
309 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
310 } else {
311 assert((ptnode_adr(adr->_idx) == NULL ||
312 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
313 }
314 #endif
315 add_local_var_and_edge(n, PointsToNode::NoEscape,
316 adr, delayed_worklist);
317 }
318 }
319
320 // Populate Connection Graph with PointsTo nodes and create simple
321 // connection graph edges.
322 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
323 assert(!_verify, "this method sould not be called for verification");
324 PhaseGVN* igvn = _igvn;
325 uint n_idx = n->_idx;
326 PointsToNode* n_ptn = ptnode_adr(n_idx);
327 if (n_ptn != NULL)
328 return; // No need to redefine PointsTo node during first iteration.
329
330 if (n->is_Call()) {
331 // Arguments to allocation and locking don't escape.
332 if (n->is_AbstractLock()) {
333 // Put Lock and Unlock nodes on IGVN worklist to process them during
334 // first IGVN optimization when escape information is still available.
335 record_for_optimizer(n);
336 } else if (n->is_Allocate()) {
337 add_call_node(n->as_Call());
338 record_for_optimizer(n);
339 } else {
340 if (n->is_CallStaticJava()) {
341 const char* name = n->as_CallStaticJava()->_name;
342 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
343 return; // Skip uncommon traps
344 }
345 // Don't mark as processed since call's arguments have to be processed.
346 delayed_worklist->push(n);
347 // Check if a call returns an object.
348 if ((n->as_Call()->returns_pointer() &&
349 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
350 (n->is_CallStaticJava() &&
351 n->as_CallStaticJava()->is_boxing_method())) {
352 add_call_node(n->as_Call());
353 }
354 }
355 return;
356 }
357 // Put this check here to process call arguments since some call nodes
358 // point to phantom_obj.
359 if (n_ptn == phantom_obj || n_ptn == null_obj)
360 return; // Skip predefined nodes.
361
362 int opcode = n->Opcode();
363 switch (opcode) {
364 case Op_AddP: {
365 Node* base = get_addp_base(n);
366 PointsToNode* ptn_base = ptnode_adr(base->_idx);
367 // Field nodes are created for all field types. They are used in
368 // adjust_scalar_replaceable_state() and split_unique_types().
369 // Note, non-oop fields will have only base edges in Connection
370 // Graph because such fields are not used for oop loads and stores.
371 int offset = address_offset(n, igvn);
372 add_field(n, PointsToNode::NoEscape, offset);
373 if (ptn_base == NULL) {
374 delayed_worklist->push(n); // Process it later.
375 } else {
376 n_ptn = ptnode_adr(n_idx);
377 add_base(n_ptn->as_Field(), ptn_base);
378 }
379 break;
380 }
381 case Op_CastX2P: {
382 map_ideal_node(n, phantom_obj);
383 break;
384 }
385 case Op_CastPP:
386 case Op_CheckCastPP:
387 case Op_EncodeP:
388 case Op_DecodeN:
389 case Op_EncodePKlass:
390 case Op_DecodeNKlass: {
391 add_local_var_and_edge(n, PointsToNode::NoEscape,
392 n->in(1), delayed_worklist);
393 break;
394 }
395 case Op_CMoveP: {
396 add_local_var(n, PointsToNode::NoEscape);
397 // Do not add edges during first iteration because some could be
398 // not defined yet.
399 delayed_worklist->push(n);
400 break;
401 }
402 case Op_ConP:
403 case Op_ConN:
404 case Op_ConNKlass: {
405 // assume all oop constants globally escape except for null
406 PointsToNode::EscapeState es;
407 const Type* t = igvn->type(n);
408 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
409 es = PointsToNode::NoEscape;
410 } else {
411 es = PointsToNode::GlobalEscape;
412 }
413 add_java_object(n, es);
414 break;
415 }
416 case Op_CreateEx: {
417 // assume that all exception objects globally escape
418 add_java_object(n, PointsToNode::GlobalEscape);
419 break;
420 }
421 case Op_LoadKlass:
422 case Op_LoadNKlass: {
423 // Unknown class is loaded
424 map_ideal_node(n, phantom_obj);
425 break;
426 }
427 case Op_LoadP:
428 case Op_LoadN:
429 case Op_LoadPLocked: {
430 add_objload_to_connection_graph(n, delayed_worklist);
431 break;
432 }
433 case Op_Parm: {
434 map_ideal_node(n, phantom_obj);
435 break;
436 }
437 case Op_PartialSubtypeCheck: {
438 // Produces Null or notNull and is used in only in CmpP so
439 // phantom_obj could be used.
440 map_ideal_node(n, phantom_obj); // Result is unknown
441 break;
442 }
443 case Op_Phi: {
444 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
445 // ThreadLocal has RawPtr type.
446 const Type* t = n->as_Phi()->type();
447 if (t->make_ptr() != NULL) {
448 add_local_var(n, PointsToNode::NoEscape);
449 // Do not add edges during first iteration because some could be
450 // not defined yet.
451 delayed_worklist->push(n);
452 }
453 break;
454 }
455 case Op_Proj: {
456 // we are only interested in the oop result projection from a call
457 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
458 n->in(0)->as_Call()->returns_pointer()) {
459 add_local_var_and_edge(n, PointsToNode::NoEscape,
460 n->in(0), delayed_worklist);
461 }
462 break;
463 }
464 case Op_Rethrow: // Exception object escapes
465 case Op_Return: {
466 if (n->req() > TypeFunc::Parms &&
467 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
468 // Treat Return value as LocalVar with GlobalEscape escape state.
469 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
470 n->in(TypeFunc::Parms), delayed_worklist);
471 }
472 break;
473 }
474 case Op_GetAndSetP:
475 case Op_GetAndSetN: {
476 add_objload_to_connection_graph(n, delayed_worklist);
477 // fallthrough
478 }
479 case Op_StoreP:
480 case Op_StoreN:
481 case Op_StoreNKlass:
482 case Op_StorePConditional:
483 case Op_CompareAndSwapP:
484 case Op_CompareAndSwapN: {
485 Node* adr = n->in(MemNode::Address);
486 const Type *adr_type = igvn->type(adr);
487 adr_type = adr_type->make_ptr();
488 if (adr_type == NULL) {
489 break; // skip dead nodes
490 }
491 if (adr_type->isa_oopptr() ||
492 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
493 (adr_type == TypeRawPtr::NOTNULL &&
494 adr->in(AddPNode::Address)->is_Proj() &&
495 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
496 delayed_worklist->push(n); // Process it later.
497 #ifdef ASSERT
498 assert(adr->is_AddP(), "expecting an AddP");
499 if (adr_type == TypeRawPtr::NOTNULL) {
500 // Verify a raw address for a store captured by Initialize node.
501 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
502 assert(offs != Type::OffsetBot, "offset must be a constant");
503 }
504 #endif
505 } else {
506 // Ignore copy the displaced header to the BoxNode (OSR compilation).
507 if (adr->is_BoxLock())
508 break;
509 // Stored value escapes in unsafe access.
510 if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
511 // Pointer stores in G1 barriers looks like unsafe access.
512 // Ignore such stores to be able scalar replace non-escaping
513 // allocations.
514 if (UseG1GC && adr->is_AddP()) {
515 Node* base = get_addp_base(adr);
516 if (base->Opcode() == Op_LoadP &&
517 base->in(MemNode::Address)->is_AddP()) {
518 adr = base->in(MemNode::Address);
519 Node* tls = get_addp_base(adr);
520 if (tls->Opcode() == Op_ThreadLocal) {
521 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
522 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
523 PtrQueue::byte_offset_of_buf())) {
524 break; // G1 pre barier previous oop value store.
525 }
526 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
527 PtrQueue::byte_offset_of_buf())) {
528 break; // G1 post barier card address store.
529 }
530 }
531 }
532 }
533 delayed_worklist->push(n); // Process unsafe access later.
534 break;
535 }
536 #ifdef ASSERT
537 n->dump(1);
538 assert(false, "not unsafe or G1 barrier raw StoreP");
539 #endif
540 }
541 break;
542 }
543 case Op_AryEq:
544 case Op_StrComp:
545 case Op_StrEquals:
546 case Op_StrIndexOf:
547 case Op_EncodeISOArray: {
548 add_local_var(n, PointsToNode::ArgEscape);
549 delayed_worklist->push(n); // Process it later.
550 break;
551 }
552 case Op_ThreadLocal: {
553 add_java_object(n, PointsToNode::ArgEscape);
554 break;
555 }
556 default:
557 ; // Do nothing for nodes not related to EA.
558 }
559 return;
560 }
561
562 #ifdef ASSERT
563 #define ELSE_FAIL(name) \
564 /* Should not be called for not pointer type. */ \
565 n->dump(1); \
566 assert(false, name); \
567 break;
568 #else
569 #define ELSE_FAIL(name) \
570 break;
571 #endif
572
573 // Add final simple edges to graph.
574 void ConnectionGraph::add_final_edges(Node *n) {
575 PointsToNode* n_ptn = ptnode_adr(n->_idx);
576 #ifdef ASSERT
577 if (_verify && n_ptn->is_JavaObject())
578 return; // This method does not change graph for JavaObject.
579 #endif
580
581 if (n->is_Call()) {
582 process_call_arguments(n->as_Call());
583 return;
584 }
585 assert(n->is_Store() || n->is_LoadStore() ||
586 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
587 "node should be registered already");
588 int opcode = n->Opcode();
589 switch (opcode) {
590 case Op_AddP: {
591 Node* base = get_addp_base(n);
592 PointsToNode* ptn_base = ptnode_adr(base->_idx);
593 assert(ptn_base != NULL, "field's base should be registered");
594 add_base(n_ptn->as_Field(), ptn_base);
595 break;
596 }
597 case Op_CastPP:
598 case Op_CheckCastPP:
599 case Op_EncodeP:
600 case Op_DecodeN:
601 case Op_EncodePKlass:
602 case Op_DecodeNKlass: {
603 add_local_var_and_edge(n, PointsToNode::NoEscape,
604 n->in(1), NULL);
605 break;
606 }
607 case Op_CMoveP: {
608 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
609 Node* in = n->in(i);
610 if (in == NULL)
611 continue; // ignore NULL
612 Node* uncast_in = in->uncast();
613 if (uncast_in->is_top() || uncast_in == n)
614 continue; // ignore top or inputs which go back this node
615 PointsToNode* ptn = ptnode_adr(in->_idx);
616 assert(ptn != NULL, "node should be registered");
617 add_edge(n_ptn, ptn);
618 }
619 break;
620 }
621 case Op_LoadP:
622 case Op_LoadN:
623 case Op_LoadPLocked: {
624 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
625 // ThreadLocal has RawPtr type.
626 const Type* t = _igvn->type(n);
627 if (t->make_ptr() != NULL) {
628 Node* adr = n->in(MemNode::Address);
629 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
630 break;
631 }
632 ELSE_FAIL("Op_LoadP");
633 }
634 case Op_Phi: {
635 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
636 // ThreadLocal has RawPtr type.
637 const Type* t = n->as_Phi()->type();
638 if (t->make_ptr() != NULL) {
639 for (uint i = 1; i < n->req(); i++) {
640 Node* in = n->in(i);
641 if (in == NULL)
642 continue; // ignore NULL
643 Node* uncast_in = in->uncast();
644 if (uncast_in->is_top() || uncast_in == n)
645 continue; // ignore top or inputs which go back this node
646 PointsToNode* ptn = ptnode_adr(in->_idx);
647 assert(ptn != NULL, "node should be registered");
648 add_edge(n_ptn, ptn);
649 }
650 break;
651 }
652 ELSE_FAIL("Op_Phi");
653 }
654 case Op_Proj: {
655 // we are only interested in the oop result projection from a call
656 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
657 n->in(0)->as_Call()->returns_pointer()) {
658 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
659 break;
660 }
661 ELSE_FAIL("Op_Proj");
662 }
663 case Op_Rethrow: // Exception object escapes
664 case Op_Return: {
665 if (n->req() > TypeFunc::Parms &&
666 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
667 // Treat Return value as LocalVar with GlobalEscape escape state.
668 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
669 n->in(TypeFunc::Parms), NULL);
670 break;
671 }
672 ELSE_FAIL("Op_Return");
673 }
674 case Op_StoreP:
675 case Op_StoreN:
676 case Op_StoreNKlass:
677 case Op_StorePConditional:
678 case Op_CompareAndSwapP:
679 case Op_CompareAndSwapN:
680 case Op_GetAndSetP:
681 case Op_GetAndSetN: {
682 Node* adr = n->in(MemNode::Address);
683 const Type *adr_type = _igvn->type(adr);
684 adr_type = adr_type->make_ptr();
685 #ifdef ASSERT
686 if (adr_type == NULL) {
687 n->dump(1);
688 assert(adr_type != NULL, "dead node should not be on list");
689 break;
690 }
691 #endif
692 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
693 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
694 }
695 if (adr_type->isa_oopptr() ||
696 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
697 (adr_type == TypeRawPtr::NOTNULL &&
698 adr->in(AddPNode::Address)->is_Proj() &&
699 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
700 // Point Address to Value
701 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
702 assert(adr_ptn != NULL &&
703 adr_ptn->as_Field()->is_oop(), "node should be registered");
704 Node *val = n->in(MemNode::ValueIn);
705 PointsToNode* ptn = ptnode_adr(val->_idx);
706 assert(ptn != NULL, "node should be registered");
707 add_edge(adr_ptn, ptn);
708 break;
709 } else if ((opcode == Op_StoreP) && (adr_type == TypeRawPtr::BOTTOM)) {
710 // Stored value escapes in unsafe access.
711 Node *val = n->in(MemNode::ValueIn);
712 PointsToNode* ptn = ptnode_adr(val->_idx);
713 assert(ptn != NULL, "node should be registered");
714 set_escape_state(ptn, PointsToNode::GlobalEscape);
715 // Add edge to object for unsafe access with offset.
716 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
717 assert(adr_ptn != NULL, "node should be registered");
718 if (adr_ptn->is_Field()) {
719 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
720 add_edge(adr_ptn, ptn);
721 }
722 break;
723 }
724 ELSE_FAIL("Op_StoreP");
725 }
726 case Op_AryEq:
727 case Op_StrComp:
728 case Op_StrEquals:
729 case Op_StrIndexOf:
730 case Op_EncodeISOArray: {
731 // char[] arrays passed to string intrinsic do not escape but
732 // they are not scalar replaceable. Adjust escape state for them.
733 // Start from in(2) edge since in(1) is memory edge.
734 for (uint i = 2; i < n->req(); i++) {
735 Node* adr = n->in(i);
736 const Type* at = _igvn->type(adr);
737 if (!adr->is_top() && at->isa_ptr()) {
738 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
739 at->isa_ptr() != NULL, "expecting a pointer");
740 if (adr->is_AddP()) {
741 adr = get_addp_base(adr);
742 }
743 PointsToNode* ptn = ptnode_adr(adr->_idx);
744 assert(ptn != NULL, "node should be registered");
745 add_edge(n_ptn, ptn);
746 }
747 }
748 break;
749 }
750 default: {
751 // This method should be called only for EA specific nodes which may
752 // miss some edges when they were created.
753 #ifdef ASSERT
754 n->dump(1);
755 #endif
756 guarantee(false, "unknown node");
757 }
758 }
759 return;
760 }
761
762 void ConnectionGraph::add_call_node(CallNode* call) {
763 assert(call->returns_pointer(), "only for call which returns pointer");
764 uint call_idx = call->_idx;
765 if (call->is_Allocate()) {
766 Node* k = call->in(AllocateNode::KlassNode);
767 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
768 assert(kt != NULL, "TypeKlassPtr required.");
769 ciKlass* cik = kt->klass();
770 PointsToNode::EscapeState es = PointsToNode::NoEscape;
771 bool scalar_replaceable = true;
772 if (call->is_AllocateArray()) {
773 if (!cik->is_array_klass()) { // StressReflectiveCode
774 es = PointsToNode::GlobalEscape;
775 } else {
776 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
777 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
778 // Not scalar replaceable if the length is not constant or too big.
779 scalar_replaceable = false;
780 }
781 }
782 } else { // Allocate instance
783 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
784 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
785 !cik->is_instance_klass() || // StressReflectiveCode
786 cik->as_instance_klass()->has_finalizer()) {
787 es = PointsToNode::GlobalEscape;
788 }
789 }
790 add_java_object(call, es);
791 PointsToNode* ptn = ptnode_adr(call_idx);
792 if (!scalar_replaceable && ptn->scalar_replaceable()) {
793 ptn->set_scalar_replaceable(false);
794 }
795 } else if (call->is_CallStaticJava()) {
796 // Call nodes could be different types:
797 //
798 // 1. CallDynamicJavaNode (what happened during call is unknown):
799 //
800 // - mapped to GlobalEscape JavaObject node if oop is returned;
801 //
802 // - all oop arguments are escaping globally;
803 //
804 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
805 //
806 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
807 //
808 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
809 // - mapped to NoEscape JavaObject node if non-escaping object allocated
810 // during call is returned;
811 // - mapped to ArgEscape LocalVar node pointed to object arguments
812 // which are returned and does not escape during call;
813 //
814 // - oop arguments escaping status is defined by bytecode analysis;
815 //
816 // For a static call, we know exactly what method is being called.
817 // Use bytecode estimator to record whether the call's return value escapes.
818 ciMethod* meth = call->as_CallJava()->method();
819 if (meth == NULL) {
820 const char* name = call->as_CallStaticJava()->_name;
821 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
822 // Returns a newly allocated unescaped object.
823 add_java_object(call, PointsToNode::NoEscape);
824 ptnode_adr(call_idx)->set_scalar_replaceable(false);
825 } else if (meth->is_boxing_method()) {
826 // Returns boxing object
827 PointsToNode::EscapeState es;
828 vmIntrinsics::ID intr = meth->intrinsic_id();
829 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
830 // It does not escape if object is always allocated.
831 es = PointsToNode::NoEscape;
832 } else {
833 // It escapes globally if object could be loaded from cache.
834 es = PointsToNode::GlobalEscape;
835 }
836 add_java_object(call, es);
837 } else {
838 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
839 call_analyzer->copy_dependencies(_compile->dependencies());
840 if (call_analyzer->is_return_allocated()) {
841 // Returns a newly allocated unescaped object, simply
842 // update dependency information.
843 // Mark it as NoEscape so that objects referenced by
844 // it's fields will be marked as NoEscape at least.
845 add_java_object(call, PointsToNode::NoEscape);
846 ptnode_adr(call_idx)->set_scalar_replaceable(false);
847 } else {
848 // Determine whether any arguments are returned.
849 const TypeTuple* d = call->tf()->domain();
850 bool ret_arg = false;
851 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
852 if (d->field_at(i)->isa_ptr() != NULL &&
853 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
854 ret_arg = true;
855 break;
856 }
857 }
858 if (ret_arg) {
859 add_local_var(call, PointsToNode::ArgEscape);
860 } else {
861 // Returns unknown object.
862 map_ideal_node(call, phantom_obj);
863 }
864 }
865 }
866 } else {
867 // An other type of call, assume the worst case:
868 // returned value is unknown and globally escapes.
869 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
870 map_ideal_node(call, phantom_obj);
871 }
872 }
873
874 void ConnectionGraph::process_call_arguments(CallNode *call) {
875 bool is_arraycopy = false;
876 switch (call->Opcode()) {
877 #ifdef ASSERT
878 case Op_Allocate:
879 case Op_AllocateArray:
880 case Op_Lock:
881 case Op_Unlock:
882 assert(false, "should be done already");
883 break;
884 #endif
885 case Op_ArrayCopy:
886 case Op_CallLeafNoFP:
887 // Most array copies are ArrayCopy nodes at this point but there
888 // are still a few direct calls to the copy subroutines (See
889 // PhaseStringOpts::copy_string())
890 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
891 (call->as_CallLeaf()->_name != NULL &&
892 strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
893 // fall through
894 case Op_CallLeaf: {
895 // Stub calls, objects do not escape but they are not scale replaceable.
896 // Adjust escape state for outgoing arguments.
897 const TypeTuple * d = call->tf()->domain();
898 bool src_has_oops = false;
899 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
900 const Type* at = d->field_at(i);
901 Node *arg = call->in(i);
902 if (arg == NULL) {
903 continue;
904 }
905 const Type *aat = _igvn->type(arg);
906 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
907 continue;
908 if (arg->is_AddP()) {
909 //
910 // The inline_native_clone() case when the arraycopy stub is called
911 // after the allocation before Initialize and CheckCastPP nodes.
912 // Or normal arraycopy for object arrays case.
913 //
914 // Set AddP's base (Allocate) as not scalar replaceable since
915 // pointer to the base (with offset) is passed as argument.
916 //
917 arg = get_addp_base(arg);
918 }
919 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
920 assert(arg_ptn != NULL, "should be registered");
921 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
922 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
923 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
924 aat->isa_ptr() != NULL, "expecting an Ptr");
925 bool arg_has_oops = aat->isa_oopptr() &&
926 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
927 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
928 if (i == TypeFunc::Parms) {
929 src_has_oops = arg_has_oops;
930 }
931 //
932 // src or dst could be j.l.Object when other is basic type array:
933 //
934 // arraycopy(char[],0,Object*,0,size);
935 // arraycopy(Object*,0,char[],0,size);
936 //
937 // Don't add edges in such cases.
938 //
939 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
940 arg_has_oops && (i > TypeFunc::Parms);
941 #ifdef ASSERT
942 if (!(is_arraycopy ||
943 (call->as_CallLeaf()->_name != NULL &&
944 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
945 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
946 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
947 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
948 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
949 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
950 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
951 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
952 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
953 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
954 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
955 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
956 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
957 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0)
958 ))) {
959 call->dump();
960 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
961 }
962 #endif
963 // Always process arraycopy's destination object since
964 // we need to add all possible edges to references in
965 // source object.
966 if (arg_esc >= PointsToNode::ArgEscape &&
967 !arg_is_arraycopy_dest) {
968 continue;
969 }
970 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
971 if (arg_is_arraycopy_dest) {
972 Node* src = call->in(TypeFunc::Parms);
973 if (src->is_AddP()) {
974 src = get_addp_base(src);
975 }
976 PointsToNode* src_ptn = ptnode_adr(src->_idx);
977 assert(src_ptn != NULL, "should be registered");
978 if (arg_ptn != src_ptn) {
979 // Special arraycopy edge:
980 // A destination object's field can't have the source object
981 // as base since objects escape states are not related.
982 // Only escape state of destination object's fields affects
983 // escape state of fields in source object.
984 add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
985 }
986 }
987 }
988 }
989 break;
990 }
991 case Op_CallStaticJava: {
992 // For a static call, we know exactly what method is being called.
993 // Use bytecode estimator to record the call's escape affects
994 #ifdef ASSERT
995 const char* name = call->as_CallStaticJava()->_name;
996 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
997 #endif
998 ciMethod* meth = call->as_CallJava()->method();
999 if ((meth != NULL) && meth->is_boxing_method()) {
1000 break; // Boxing methods do not modify any oops.
1001 }
1002 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1003 // fall-through if not a Java method or no analyzer information
1004 if (call_analyzer != NULL) {
1005 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1006 const TypeTuple* d = call->tf()->domain();
1007 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1008 const Type* at = d->field_at(i);
1009 int k = i - TypeFunc::Parms;
1010 Node* arg = call->in(i);
1011 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1012 if (at->isa_ptr() != NULL &&
1013 call_analyzer->is_arg_returned(k)) {
1014 // The call returns arguments.
1015 if (call_ptn != NULL) { // Is call's result used?
1016 assert(call_ptn->is_LocalVar(), "node should be registered");
1017 assert(arg_ptn != NULL, "node should be registered");
1018 add_edge(call_ptn, arg_ptn);
1019 }
1020 }
1021 if (at->isa_oopptr() != NULL &&
1022 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1023 if (!call_analyzer->is_arg_stack(k)) {
1024 // The argument global escapes
1025 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1026 } else {
1027 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1028 if (!call_analyzer->is_arg_local(k)) {
1029 // The argument itself doesn't escape, but any fields might
1030 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1031 }
1032 }
1033 }
1034 }
1035 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1036 // The call returns arguments.
1037 assert(call_ptn->edge_count() > 0, "sanity");
1038 if (!call_analyzer->is_return_local()) {
1039 // Returns also unknown object.
1040 add_edge(call_ptn, phantom_obj);
1041 }
1042 }
1043 break;
1044 }
1045 }
1046 default: {
1047 // Fall-through here if not a Java method or no analyzer information
1048 // or some other type of call, assume the worst case: all arguments
1049 // globally escape.
1050 const TypeTuple* d = call->tf()->domain();
1051 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1052 const Type* at = d->field_at(i);
1053 if (at->isa_oopptr() != NULL) {
1054 Node* arg = call->in(i);
1055 if (arg->is_AddP()) {
1056 arg = get_addp_base(arg);
1057 }
1058 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1059 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1060 }
1061 }
1062 }
1063 }
1064 }
1065
1066
1067 // Finish Graph construction.
1068 bool ConnectionGraph::complete_connection_graph(
1069 GrowableArray<PointsToNode*>& ptnodes_worklist,
1070 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1071 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1072 GrowableArray<FieldNode*>& oop_fields_worklist) {
1073 // Normally only 1-3 passes needed to build Connection Graph depending
1074 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1075 // Set limit to 20 to catch situation when something did go wrong and
1076 // bailout Escape Analysis.
1077 // Also limit build time to 30 sec (60 in debug VM).
1078 #define CG_BUILD_ITER_LIMIT 20
1079 #ifdef ASSERT
1080 #define CG_BUILD_TIME_LIMIT 60.0
1081 #else
1082 #define CG_BUILD_TIME_LIMIT 30.0
1083 #endif
1084
1085 // Propagate GlobalEscape and ArgEscape escape states and check that
1086 // we still have non-escaping objects. The method pushs on _worklist
1087 // Field nodes which reference phantom_object.
1088 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1089 return false; // Nothing to do.
1090 }
1091 // Now propagate references to all JavaObject nodes.
1092 int java_objects_length = java_objects_worklist.length();
1093 elapsedTimer time;
1094 int new_edges = 1;
1095 int iterations = 0;
1096 do {
1097 while ((new_edges > 0) &&
1098 (iterations++ < CG_BUILD_ITER_LIMIT) &&
1099 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1100 time.start();
1101 new_edges = 0;
1102 // Propagate references to phantom_object for nodes pushed on _worklist
1103 // by find_non_escaped_objects() and find_field_value().
1104 new_edges += add_java_object_edges(phantom_obj, false);
1105 for (int next = 0; next < java_objects_length; ++next) {
1106 JavaObjectNode* ptn = java_objects_worklist.at(next);
1107 new_edges += add_java_object_edges(ptn, true);
1108 }
1109 if (new_edges > 0) {
1110 // Update escape states on each iteration if graph was updated.
1111 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1112 return false; // Nothing to do.
1113 }
1114 }
1115 time.stop();
1116 }
1117 if ((iterations < CG_BUILD_ITER_LIMIT) &&
1118 (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1119 time.start();
1120 // Find fields which have unknown value.
1121 int fields_length = oop_fields_worklist.length();
1122 for (int next = 0; next < fields_length; next++) {
1123 FieldNode* field = oop_fields_worklist.at(next);
1124 if (field->edge_count() == 0) {
1125 new_edges += find_field_value(field);
1126 // This code may added new edges to phantom_object.
1127 // Need an other cycle to propagate references to phantom_object.
1128 }
1129 }
1130 time.stop();
1131 } else {
1132 new_edges = 0; // Bailout
1133 }
1134 } while (new_edges > 0);
1135
1136 // Bailout if passed limits.
1137 if ((iterations >= CG_BUILD_ITER_LIMIT) ||
1138 (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1139 Compile* C = _compile;
1140 if (C->log() != NULL) {
1141 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1142 C->log()->text("%s", (iterations >= CG_BUILD_ITER_LIMIT) ? "iterations" : "time");
1143 C->log()->end_elem(" limit'");
1144 }
1145 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1146 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1147 // Possible infinite build_connection_graph loop,
1148 // bailout (no changes to ideal graph were made).
1149 return false;
1150 }
1151 #ifdef ASSERT
1152 if (Verbose && PrintEscapeAnalysis) {
1153 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1154 iterations, nodes_size(), ptnodes_worklist.length());
1155 }
1156 #endif
1157
1158 #undef CG_BUILD_ITER_LIMIT
1159 #undef CG_BUILD_TIME_LIMIT
1160
1161 // Find fields initialized by NULL for non-escaping Allocations.
1162 int non_escaped_length = non_escaped_worklist.length();
1163 for (int next = 0; next < non_escaped_length; next++) {
1164 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1165 PointsToNode::EscapeState es = ptn->escape_state();
1166 assert(es <= PointsToNode::ArgEscape, "sanity");
1167 if (es == PointsToNode::NoEscape) {
1168 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1169 // Adding references to NULL object does not change escape states
1170 // since it does not escape. Also no fields are added to NULL object.
1171 add_java_object_edges(null_obj, false);
1172 }
1173 }
1174 Node* n = ptn->ideal_node();
1175 if (n->is_Allocate()) {
1176 // The object allocated by this Allocate node will never be
1177 // seen by an other thread. Mark it so that when it is
1178 // expanded no MemBarStoreStore is added.
1179 InitializeNode* ini = n->as_Allocate()->initialization();
1180 if (ini != NULL)
1181 ini->set_does_not_escape();
1182 }
1183 }
1184 return true; // Finished graph construction.
1185 }
1186
1187 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1188 // and check that we still have non-escaping java objects.
1189 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1190 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1191 GrowableArray<PointsToNode*> escape_worklist;
1192 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1193 int ptnodes_length = ptnodes_worklist.length();
1194 for (int next = 0; next < ptnodes_length; ++next) {
1195 PointsToNode* ptn = ptnodes_worklist.at(next);
1196 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1197 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1198 escape_worklist.push(ptn);
1199 }
1200 }
1201 // Set escape states to referenced nodes (edges list).
1202 while (escape_worklist.length() > 0) {
1203 PointsToNode* ptn = escape_worklist.pop();
1204 PointsToNode::EscapeState es = ptn->escape_state();
1205 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1206 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1207 es >= PointsToNode::ArgEscape) {
1208 // GlobalEscape or ArgEscape state of field means it has unknown value.
1209 if (add_edge(ptn, phantom_obj)) {
1210 // New edge was added
1211 add_field_uses_to_worklist(ptn->as_Field());
1212 }
1213 }
1214 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1215 PointsToNode* e = i.get();
1216 if (e->is_Arraycopy()) {
1217 assert(ptn->arraycopy_dst(), "sanity");
1218 // Propagate only fields escape state through arraycopy edge.
1219 if (e->fields_escape_state() < field_es) {
1220 set_fields_escape_state(e, field_es);
1221 escape_worklist.push(e);
1222 }
1223 } else if (es >= field_es) {
1224 // fields_escape_state is also set to 'es' if it is less than 'es'.
1225 if (e->escape_state() < es) {
1226 set_escape_state(e, es);
1227 escape_worklist.push(e);
1228 }
1229 } else {
1230 // Propagate field escape state.
1231 bool es_changed = false;
1232 if (e->fields_escape_state() < field_es) {
1233 set_fields_escape_state(e, field_es);
1234 es_changed = true;
1235 }
1236 if ((e->escape_state() < field_es) &&
1237 e->is_Field() && ptn->is_JavaObject() &&
1238 e->as_Field()->is_oop()) {
1239 // Change escape state of referenced fileds.
1240 set_escape_state(e, field_es);
1241 es_changed = true;;
1242 } else if (e->escape_state() < es) {
1243 set_escape_state(e, es);
1244 es_changed = true;;
1245 }
1246 if (es_changed) {
1247 escape_worklist.push(e);
1248 }
1249 }
1250 }
1251 }
1252 // Remove escaped objects from non_escaped list.
1253 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1254 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1255 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1256 non_escaped_worklist.delete_at(next);
1257 }
1258 if (ptn->escape_state() == PointsToNode::NoEscape) {
1259 // Find fields in non-escaped allocations which have unknown value.
1260 find_init_values(ptn, phantom_obj, NULL);
1261 }
1262 }
1263 return (non_escaped_worklist.length() > 0);
1264 }
1265
1266 // Add all references to JavaObject node by walking over all uses.
1267 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1268 int new_edges = 0;
1269 if (populate_worklist) {
1270 // Populate _worklist by uses of jobj's uses.
1271 for (UseIterator i(jobj); i.has_next(); i.next()) {
1272 PointsToNode* use = i.get();
1273 if (use->is_Arraycopy())
1274 continue;
1275 add_uses_to_worklist(use);
1276 if (use->is_Field() && use->as_Field()->is_oop()) {
1277 // Put on worklist all field's uses (loads) and
1278 // related field nodes (same base and offset).
1279 add_field_uses_to_worklist(use->as_Field());
1280 }
1281 }
1282 }
1283 while(_worklist.length() > 0) {
1284 PointsToNode* use = _worklist.pop();
1285 if (PointsToNode::is_base_use(use)) {
1286 // Add reference from jobj to field and from field to jobj (field's base).
1287 use = PointsToNode::get_use_node(use)->as_Field();
1288 if (add_base(use->as_Field(), jobj)) {
1289 new_edges++;
1290 }
1291 continue;
1292 }
1293 assert(!use->is_JavaObject(), "sanity");
1294 if (use->is_Arraycopy()) {
1295 if (jobj == null_obj) // NULL object does not have field edges
1296 continue;
1297 // Added edge from Arraycopy node to arraycopy's source java object
1298 if (add_edge(use, jobj)) {
1299 jobj->set_arraycopy_src();
1300 new_edges++;
1301 }
1302 // and stop here.
1303 continue;
1304 }
1305 if (!add_edge(use, jobj))
1306 continue; // No new edge added, there was such edge already.
1307 new_edges++;
1308 if (use->is_LocalVar()) {
1309 add_uses_to_worklist(use);
1310 if (use->arraycopy_dst()) {
1311 for (EdgeIterator i(use); i.has_next(); i.next()) {
1312 PointsToNode* e = i.get();
1313 if (e->is_Arraycopy()) {
1314 if (jobj == null_obj) // NULL object does not have field edges
1315 continue;
1316 // Add edge from arraycopy's destination java object to Arraycopy node.
1317 if (add_edge(jobj, e)) {
1318 new_edges++;
1319 jobj->set_arraycopy_dst();
1320 }
1321 }
1322 }
1323 }
1324 } else {
1325 // Added new edge to stored in field values.
1326 // Put on worklist all field's uses (loads) and
1327 // related field nodes (same base and offset).
1328 add_field_uses_to_worklist(use->as_Field());
1329 }
1330 }
1331 return new_edges;
1332 }
1333
1334 // Put on worklist all related field nodes.
1335 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1336 assert(field->is_oop(), "sanity");
1337 int offset = field->offset();
1338 add_uses_to_worklist(field);
1339 // Loop over all bases of this field and push on worklist Field nodes
1340 // with the same offset and base (since they may reference the same field).
1341 for (BaseIterator i(field); i.has_next(); i.next()) {
1342 PointsToNode* base = i.get();
1343 add_fields_to_worklist(field, base);
1344 // Check if the base was source object of arraycopy and go over arraycopy's
1345 // destination objects since values stored to a field of source object are
1346 // accessable by uses (loads) of fields of destination objects.
1347 if (base->arraycopy_src()) {
1348 for (UseIterator j(base); j.has_next(); j.next()) {
1349 PointsToNode* arycp = j.get();
1350 if (arycp->is_Arraycopy()) {
1351 for (UseIterator k(arycp); k.has_next(); k.next()) {
1352 PointsToNode* abase = k.get();
1353 if (abase->arraycopy_dst() && abase != base) {
1354 // Look for the same arracopy reference.
1355 add_fields_to_worklist(field, abase);
1356 }
1357 }
1358 }
1359 }
1360 }
1361 }
1362 }
1363
1364 // Put on worklist all related field nodes.
1365 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1366 int offset = field->offset();
1367 if (base->is_LocalVar()) {
1368 for (UseIterator j(base); j.has_next(); j.next()) {
1369 PointsToNode* f = j.get();
1370 if (PointsToNode::is_base_use(f)) { // Field
1371 f = PointsToNode::get_use_node(f);
1372 if (f == field || !f->as_Field()->is_oop())
1373 continue;
1374 int offs = f->as_Field()->offset();
1375 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1376 add_to_worklist(f);
1377 }
1378 }
1379 }
1380 } else {
1381 assert(base->is_JavaObject(), "sanity");
1382 if (// Skip phantom_object since it is only used to indicate that
1383 // this field's content globally escapes.
1384 (base != phantom_obj) &&
1385 // NULL object node does not have fields.
1386 (base != null_obj)) {
1387 for (EdgeIterator i(base); i.has_next(); i.next()) {
1388 PointsToNode* f = i.get();
1389 // Skip arraycopy edge since store to destination object field
1390 // does not update value in source object field.
1391 if (f->is_Arraycopy()) {
1392 assert(base->arraycopy_dst(), "sanity");
1393 continue;
1394 }
1395 if (f == field || !f->as_Field()->is_oop())
1396 continue;
1397 int offs = f->as_Field()->offset();
1398 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1399 add_to_worklist(f);
1400 }
1401 }
1402 }
1403 }
1404 }
1405
1406 // Find fields which have unknown value.
1407 int ConnectionGraph::find_field_value(FieldNode* field) {
1408 // Escaped fields should have init value already.
1409 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1410 int new_edges = 0;
1411 for (BaseIterator i(field); i.has_next(); i.next()) {
1412 PointsToNode* base = i.get();
1413 if (base->is_JavaObject()) {
1414 // Skip Allocate's fields which will be processed later.
1415 if (base->ideal_node()->is_Allocate())
1416 return 0;
1417 assert(base == null_obj, "only NULL ptr base expected here");
1418 }
1419 }
1420 if (add_edge(field, phantom_obj)) {
1421 // New edge was added
1422 new_edges++;
1423 add_field_uses_to_worklist(field);
1424 }
1425 return new_edges;
1426 }
1427
1428 // Find fields initializing values for allocations.
1429 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1430 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1431 int new_edges = 0;
1432 Node* alloc = pta->ideal_node();
1433 if (init_val == phantom_obj) {
1434 // Do nothing for Allocate nodes since its fields values are "known".
1435 if (alloc->is_Allocate())
1436 return 0;
1437 assert(alloc->as_CallStaticJava(), "sanity");
1438 #ifdef ASSERT
1439 if (alloc->as_CallStaticJava()->method() == NULL) {
1440 const char* name = alloc->as_CallStaticJava()->_name;
1441 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1442 }
1443 #endif
1444 // Non-escaped allocation returned from Java or runtime call have
1445 // unknown values in fields.
1446 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1447 PointsToNode* field = i.get();
1448 if (field->is_Field() && field->as_Field()->is_oop()) {
1449 if (add_edge(field, phantom_obj)) {
1450 // New edge was added
1451 new_edges++;
1452 add_field_uses_to_worklist(field->as_Field());
1453 }
1454 }
1455 }
1456 return new_edges;
1457 }
1458 assert(init_val == null_obj, "sanity");
1459 // Do nothing for Call nodes since its fields values are unknown.
1460 if (!alloc->is_Allocate())
1461 return 0;
1462
1463 InitializeNode* ini = alloc->as_Allocate()->initialization();
1464 bool visited_bottom_offset = false;
1465 GrowableArray<int> offsets_worklist;
1466
1467 // Check if an oop field's initializing value is recorded and add
1468 // a corresponding NULL if field's value if it is not recorded.
1469 // Connection Graph does not record a default initialization by NULL
1470 // captured by Initialize node.
1471 //
1472 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1473 PointsToNode* field = i.get(); // Field (AddP)
1474 if (!field->is_Field() || !field->as_Field()->is_oop())
1475 continue; // Not oop field
1476 int offset = field->as_Field()->offset();
1477 if (offset == Type::OffsetBot) {
1478 if (!visited_bottom_offset) {
1479 // OffsetBot is used to reference array's element,
1480 // always add reference to NULL to all Field nodes since we don't
1481 // known which element is referenced.
1482 if (add_edge(field, null_obj)) {
1483 // New edge was added
1484 new_edges++;
1485 add_field_uses_to_worklist(field->as_Field());
1486 visited_bottom_offset = true;
1487 }
1488 }
1489 } else {
1490 // Check only oop fields.
1491 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1492 if (adr_type->isa_rawptr()) {
1493 #ifdef ASSERT
1494 // Raw pointers are used for initializing stores so skip it
1495 // since it should be recorded already
1496 Node* base = get_addp_base(field->ideal_node());
1497 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1498 (base->in(0) == alloc),"unexpected pointer type");
1499 #endif
1500 continue;
1501 }
1502 if (!offsets_worklist.contains(offset)) {
1503 offsets_worklist.append(offset);
1504 Node* value = NULL;
1505 if (ini != NULL) {
1506 // StoreP::memory_type() == T_ADDRESS
1507 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1508 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1509 // Make sure initializing store has the same type as this AddP.
1510 // This AddP may reference non existing field because it is on a
1511 // dead branch of bimorphic call which is not eliminated yet.
1512 if (store != NULL && store->is_Store() &&
1513 store->as_Store()->memory_type() == ft) {
1514 value = store->in(MemNode::ValueIn);
1515 #ifdef ASSERT
1516 if (VerifyConnectionGraph) {
1517 // Verify that AddP already points to all objects the value points to.
1518 PointsToNode* val = ptnode_adr(value->_idx);
1519 assert((val != NULL), "should be processed already");
1520 PointsToNode* missed_obj = NULL;
1521 if (val->is_JavaObject()) {
1522 if (!field->points_to(val->as_JavaObject())) {
1523 missed_obj = val;
1524 }
1525 } else {
1526 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1527 tty->print_cr("----------init store has invalid value -----");
1528 store->dump();
1529 val->dump();
1530 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1531 }
1532 for (EdgeIterator j(val); j.has_next(); j.next()) {
1533 PointsToNode* obj = j.get();
1534 if (obj->is_JavaObject()) {
1535 if (!field->points_to(obj->as_JavaObject())) {
1536 missed_obj = obj;
1537 break;
1538 }
1539 }
1540 }
1541 }
1542 if (missed_obj != NULL) {
1543 tty->print_cr("----------field---------------------------------");
1544 field->dump();
1545 tty->print_cr("----------missed referernce to object-----------");
1546 missed_obj->dump();
1547 tty->print_cr("----------object referernced by init store -----");
1548 store->dump();
1549 val->dump();
1550 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1551 }
1552 }
1553 #endif
1554 } else {
1555 // There could be initializing stores which follow allocation.
1556 // For example, a volatile field store is not collected
1557 // by Initialize node.
1558 //
1559 // Need to check for dependent loads to separate such stores from
1560 // stores which follow loads. For now, add initial value NULL so
1561 // that compare pointers optimization works correctly.
1562 }
1563 }
1564 if (value == NULL) {
1565 // A field's initializing value was not recorded. Add NULL.
1566 if (add_edge(field, null_obj)) {
1567 // New edge was added
1568 new_edges++;
1569 add_field_uses_to_worklist(field->as_Field());
1570 }
1571 }
1572 }
1573 }
1574 }
1575 return new_edges;
1576 }
1577
1578 // Adjust scalar_replaceable state after Connection Graph is built.
1579 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1580 // Search for non-escaping objects which are not scalar replaceable
1581 // and mark them to propagate the state to referenced objects.
1582
1583 // 1. An object is not scalar replaceable if the field into which it is
1584 // stored has unknown offset (stored into unknown element of an array).
1585 //
1586 for (UseIterator i(jobj); i.has_next(); i.next()) {
1587 PointsToNode* use = i.get();
1588 assert(!use->is_Arraycopy(), "sanity");
1589 if (use->is_Field()) {
1590 FieldNode* field = use->as_Field();
1591 assert(field->is_oop() && field->scalar_replaceable() &&
1592 field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
1593 if (field->offset() == Type::OffsetBot) {
1594 jobj->set_scalar_replaceable(false);
1595 return;
1596 }
1597 // 2. An object is not scalar replaceable if the field into which it is
1598 // stored has multiple bases one of which is null.
1599 if (field->base_count() > 1) {
1600 for (BaseIterator i(field); i.has_next(); i.next()) {
1601 PointsToNode* base = i.get();
1602 if (base == null_obj) {
1603 jobj->set_scalar_replaceable(false);
1604 return;
1605 }
1606 }
1607 }
1608 }
1609 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1610 // 3. An object is not scalar replaceable if it is merged with other objects.
1611 for (EdgeIterator j(use); j.has_next(); j.next()) {
1612 PointsToNode* ptn = j.get();
1613 if (ptn->is_JavaObject() && ptn != jobj) {
1614 // Mark all objects.
1615 jobj->set_scalar_replaceable(false);
1616 ptn->set_scalar_replaceable(false);
1617 }
1618 }
1619 if (!jobj->scalar_replaceable()) {
1620 return;
1621 }
1622 }
1623
1624 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1625 // Non-escaping object node should point only to field nodes.
1626 FieldNode* field = j.get()->as_Field();
1627 int offset = field->as_Field()->offset();
1628
1629 // 4. An object is not scalar replaceable if it has a field with unknown
1630 // offset (array's element is accessed in loop).
1631 if (offset == Type::OffsetBot) {
1632 jobj->set_scalar_replaceable(false);
1633 return;
1634 }
1635 // 5. Currently an object is not scalar replaceable if a LoadStore node
1636 // access its field since the field value is unknown after it.
1637 //
1638 Node* n = field->ideal_node();
1639 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1640 if (n->fast_out(i)->is_LoadStore()) {
1641 jobj->set_scalar_replaceable(false);
1642 return;
1643 }
1644 }
1645
1646 // 6. Or the address may point to more then one object. This may produce
1647 // the false positive result (set not scalar replaceable)
1648 // since the flow-insensitive escape analysis can't separate
1649 // the case when stores overwrite the field's value from the case
1650 // when stores happened on different control branches.
1651 //
1652 // Note: it will disable scalar replacement in some cases:
1653 //
1654 // Point p[] = new Point[1];
1655 // p[0] = new Point(); // Will be not scalar replaced
1656 //
1657 // but it will save us from incorrect optimizations in next cases:
1658 //
1659 // Point p[] = new Point[1];
1660 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1661 //
1662 if (field->base_count() > 1) {
1663 for (BaseIterator i(field); i.has_next(); i.next()) {
1664 PointsToNode* base = i.get();
1665 // Don't take into account LocalVar nodes which
1666 // may point to only one object which should be also
1667 // this field's base by now.
1668 if (base->is_JavaObject() && base != jobj) {
1669 // Mark all bases.
1670 jobj->set_scalar_replaceable(false);
1671 base->set_scalar_replaceable(false);
1672 }
1673 }
1674 }
1675 }
1676 }
1677
1678 #ifdef ASSERT
1679 void ConnectionGraph::verify_connection_graph(
1680 GrowableArray<PointsToNode*>& ptnodes_worklist,
1681 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1682 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1683 GrowableArray<Node*>& addp_worklist) {
1684 // Verify that graph is complete - no new edges could be added.
1685 int java_objects_length = java_objects_worklist.length();
1686 int non_escaped_length = non_escaped_worklist.length();
1687 int new_edges = 0;
1688 for (int next = 0; next < java_objects_length; ++next) {
1689 JavaObjectNode* ptn = java_objects_worklist.at(next);
1690 new_edges += add_java_object_edges(ptn, true);
1691 }
1692 assert(new_edges == 0, "graph was not complete");
1693 // Verify that escape state is final.
1694 int length = non_escaped_worklist.length();
1695 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1696 assert((non_escaped_length == non_escaped_worklist.length()) &&
1697 (non_escaped_length == length) &&
1698 (_worklist.length() == 0), "escape state was not final");
1699
1700 // Verify fields information.
1701 int addp_length = addp_worklist.length();
1702 for (int next = 0; next < addp_length; ++next ) {
1703 Node* n = addp_worklist.at(next);
1704 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1705 if (field->is_oop()) {
1706 // Verify that field has all bases
1707 Node* base = get_addp_base(n);
1708 PointsToNode* ptn = ptnode_adr(base->_idx);
1709 if (ptn->is_JavaObject()) {
1710 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1711 } else {
1712 assert(ptn->is_LocalVar(), "sanity");
1713 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1714 PointsToNode* e = i.get();
1715 if (e->is_JavaObject()) {
1716 assert(field->has_base(e->as_JavaObject()), "sanity");
1717 }
1718 }
1719 }
1720 // Verify that all fields have initializing values.
1721 if (field->edge_count() == 0) {
1722 tty->print_cr("----------field does not have references----------");
1723 field->dump();
1724 for (BaseIterator i(field); i.has_next(); i.next()) {
1725 PointsToNode* base = i.get();
1726 tty->print_cr("----------field has next base---------------------");
1727 base->dump();
1728 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1729 tty->print_cr("----------base has fields-------------------------");
1730 for (EdgeIterator j(base); j.has_next(); j.next()) {
1731 j.get()->dump();
1732 }
1733 tty->print_cr("----------base has references---------------------");
1734 for (UseIterator j(base); j.has_next(); j.next()) {
1735 j.get()->dump();
1736 }
1737 }
1738 }
1739 for (UseIterator i(field); i.has_next(); i.next()) {
1740 i.get()->dump();
1741 }
1742 assert(field->edge_count() > 0, "sanity");
1743 }
1744 }
1745 }
1746 }
1747 #endif
1748
1749 // Optimize ideal graph.
1750 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1751 GrowableArray<Node*>& storestore_worklist) {
1752 Compile* C = _compile;
1753 PhaseIterGVN* igvn = _igvn;
1754 if (EliminateLocks) {
1755 // Mark locks before changing ideal graph.
1756 int cnt = C->macro_count();
1757 for( int i=0; i < cnt; i++ ) {
1758 Node *n = C->macro_node(i);
1759 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1760 AbstractLockNode* alock = n->as_AbstractLock();
1761 if (!alock->is_non_esc_obj()) {
1762 if (not_global_escape(alock->obj_node())) {
1763 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1764 // The lock could be marked eliminated by lock coarsening
1765 // code during first IGVN before EA. Replace coarsened flag
1766 // to eliminate all associated locks/unlocks.
1767 alock->set_non_esc_obj();
1768 }
1769 }
1770 }
1771 }
1772 }
1773
1774 if (OptimizePtrCompare) {
1775 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1776 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1777 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1778 // Optimize objects compare.
1779 while (ptr_cmp_worklist.length() != 0) {
1780 Node *n = ptr_cmp_worklist.pop();
1781 Node *res = optimize_ptr_compare(n);
1782 if (res != NULL) {
1783 #ifndef PRODUCT
1784 if (PrintOptimizePtrCompare) {
1785 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"));
1786 if (Verbose) {
1787 n->dump(1);
1788 }
1789 }
1790 #endif
1791 igvn->replace_node(n, res);
1792 }
1793 }
1794 // cleanup
1795 if (_pcmp_neq->outcnt() == 0)
1796 igvn->hash_delete(_pcmp_neq);
1797 if (_pcmp_eq->outcnt() == 0)
1798 igvn->hash_delete(_pcmp_eq);
1799 }
1800
1801 // For MemBarStoreStore nodes added in library_call.cpp, check
1802 // escape status of associated AllocateNode and optimize out
1803 // MemBarStoreStore node if the allocated object never escapes.
1804 while (storestore_worklist.length() != 0) {
1805 Node *n = storestore_worklist.pop();
1806 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1807 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1808 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1809 if (not_global_escape(alloc)) {
1810 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1811 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1812 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1813 igvn->register_new_node_with_optimizer(mb);
1814 igvn->replace_node(storestore, mb);
1815 }
1816 }
1817 }
1818
1819 // Optimize objects compare.
1820 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1821 assert(OptimizePtrCompare, "sanity");
1822 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1823 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1824 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1825 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1826 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1827 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1828
1829 // Check simple cases first.
1830 if (jobj1 != NULL) {
1831 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1832 if (jobj1 == jobj2) {
1833 // Comparing the same not escaping object.
1834 return _pcmp_eq;
1835 }
1836 Node* obj = jobj1->ideal_node();
1837 // Comparing not escaping allocation.
1838 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1839 !ptn2->points_to(jobj1)) {
1840 return _pcmp_neq; // This includes nullness check.
1841 }
1842 }
1843 }
1844 if (jobj2 != NULL) {
1845 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1846 Node* obj = jobj2->ideal_node();
1847 // Comparing not escaping allocation.
1848 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1849 !ptn1->points_to(jobj2)) {
1850 return _pcmp_neq; // This includes nullness check.
1851 }
1852 }
1853 }
1854 if (jobj1 != NULL && jobj1 != phantom_obj &&
1855 jobj2 != NULL && jobj2 != phantom_obj &&
1856 jobj1->ideal_node()->is_Con() &&
1857 jobj2->ideal_node()->is_Con()) {
1858 // Klass or String constants compare. Need to be careful with
1859 // compressed pointers - compare types of ConN and ConP instead of nodes.
1860 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1861 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1862 if (t1->make_ptr() == t2->make_ptr()) {
1863 return _pcmp_eq;
1864 } else {
1865 return _pcmp_neq;
1866 }
1867 }
1868 if (ptn1->meet(ptn2)) {
1869 return NULL; // Sets are not disjoint
1870 }
1871
1872 // Sets are disjoint.
1873 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1874 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1875 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1876 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1877 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1878 set2_has_unknown_ptr && set1_has_null_ptr) {
1879 // Check nullness of unknown object.
1880 return NULL;
1881 }
1882
1883 // Disjointness by itself is not sufficient since
1884 // alias analysis is not complete for escaped objects.
1885 // Disjoint sets are definitely unrelated only when
1886 // at least one set has only not escaping allocations.
1887 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1888 if (ptn1->non_escaping_allocation()) {
1889 return _pcmp_neq;
1890 }
1891 }
1892 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1893 if (ptn2->non_escaping_allocation()) {
1894 return _pcmp_neq;
1895 }
1896 }
1897 return NULL;
1898 }
1899
1900 // Connection Graph constuction functions.
1901
1902 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1903 PointsToNode* ptadr = _nodes.at(n->_idx);
1904 if (ptadr != NULL) {
1905 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1906 return;
1907 }
1908 Compile* C = _compile;
1909 ptadr = new (C->comp_arena()) LocalVarNode(C, n, es);
1910 _nodes.at_put(n->_idx, ptadr);
1911 }
1912
1913 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1914 PointsToNode* ptadr = _nodes.at(n->_idx);
1915 if (ptadr != NULL) {
1916 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
1917 return;
1918 }
1919 Compile* C = _compile;
1920 ptadr = new (C->comp_arena()) JavaObjectNode(C, n, es);
1921 _nodes.at_put(n->_idx, ptadr);
1922 }
1923
1924 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
1925 PointsToNode* ptadr = _nodes.at(n->_idx);
1926 if (ptadr != NULL) {
1927 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
1928 return;
1929 }
1930 bool unsafe = false;
1931 bool is_oop = is_oop_field(n, offset, &unsafe);
1932 if (unsafe) {
1933 es = PointsToNode::GlobalEscape;
1934 }
1935 Compile* C = _compile;
1936 FieldNode* field = new (C->comp_arena()) FieldNode(C, n, es, offset, is_oop);
1937 _nodes.at_put(n->_idx, field);
1938 }
1939
1940 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
1941 PointsToNode* src, PointsToNode* dst) {
1942 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
1943 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
1944 PointsToNode* ptadr = _nodes.at(n->_idx);
1945 if (ptadr != NULL) {
1946 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
1947 return;
1948 }
1949 Compile* C = _compile;
1950 ptadr = new (C->comp_arena()) ArraycopyNode(C, n, es);
1951 _nodes.at_put(n->_idx, ptadr);
1952 // Add edge from arraycopy node to source object.
1953 (void)add_edge(ptadr, src);
1954 src->set_arraycopy_src();
1955 // Add edge from destination object to arraycopy node.
1956 (void)add_edge(dst, ptadr);
1957 dst->set_arraycopy_dst();
1958 }
1959
1960 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
1961 const Type* adr_type = n->as_AddP()->bottom_type();
1962 BasicType bt = T_INT;
1963 if (offset == Type::OffsetBot) {
1964 // Check only oop fields.
1965 if (!adr_type->isa_aryptr() ||
1966 (adr_type->isa_aryptr()->klass() == NULL) ||
1967 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1968 // OffsetBot is used to reference array's element. Ignore first AddP.
1969 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
1970 bt = T_OBJECT;
1971 }
1972 }
1973 } else if (offset != oopDesc::klass_offset_in_bytes()) {
1974 if (adr_type->isa_instptr()) {
1975 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
1976 if (field != NULL) {
1977 bt = field->layout_type();
1978 } else {
1979 // Check for unsafe oop field access
1980 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1981 int opcode = n->fast_out(i)->Opcode();
1982 if (opcode == Op_StoreP || opcode == Op_LoadP ||
1983 opcode == Op_StoreN || opcode == Op_LoadN) {
1984 bt = T_OBJECT;
1985 (*unsafe) = true;
1986 break;
1987 }
1988 }
1989 }
1990 } else if (adr_type->isa_aryptr()) {
1991 if (offset == arrayOopDesc::length_offset_in_bytes()) {
1992 // Ignore array length load.
1993 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
1994 // Ignore first AddP.
1995 } else {
1996 const Type* elemtype = adr_type->isa_aryptr()->elem();
1997 bt = elemtype->array_element_basic_type();
1998 }
1999 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2000 // Allocation initialization, ThreadLocal field access, unsafe access
2001 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2002 int opcode = n->fast_out(i)->Opcode();
2003 if (opcode == Op_StoreP || opcode == Op_LoadP ||
2004 opcode == Op_StoreN || opcode == Op_LoadN) {
2005 bt = T_OBJECT;
2006 break;
2007 }
2008 }
2009 }
2010 }
2011 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2012 }
2013
2014 // Returns unique pointed java object or NULL.
2015 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2016 assert(!_collecting, "should not call when contructed graph");
2017 // If the node was created after the escape computation we can't answer.
2018 uint idx = n->_idx;
2019 if (idx >= nodes_size()) {
2020 return NULL;
2021 }
2022 PointsToNode* ptn = ptnode_adr(idx);
2023 if (ptn->is_JavaObject()) {
2024 return ptn->as_JavaObject();
2025 }
2026 assert(ptn->is_LocalVar(), "sanity");
2027 // Check all java objects it points to.
2028 JavaObjectNode* jobj = NULL;
2029 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2030 PointsToNode* e = i.get();
2031 if (e->is_JavaObject()) {
2032 if (jobj == NULL) {
2033 jobj = e->as_JavaObject();
2034 } else if (jobj != e) {
2035 return NULL;
2036 }
2037 }
2038 }
2039 return jobj;
2040 }
2041
2042 // Return true if this node points only to non-escaping allocations.
2043 bool PointsToNode::non_escaping_allocation() {
2044 if (is_JavaObject()) {
2045 Node* n = ideal_node();
2046 if (n->is_Allocate() || n->is_CallStaticJava()) {
2047 return (escape_state() == PointsToNode::NoEscape);
2048 } else {
2049 return false;
2050 }
2051 }
2052 assert(is_LocalVar(), "sanity");
2053 // Check all java objects it points to.
2054 for (EdgeIterator i(this); i.has_next(); i.next()) {
2055 PointsToNode* e = i.get();
2056 if (e->is_JavaObject()) {
2057 Node* n = e->ideal_node();
2058 if ((e->escape_state() != PointsToNode::NoEscape) ||
2059 !(n->is_Allocate() || n->is_CallStaticJava())) {
2060 return false;
2061 }
2062 }
2063 }
2064 return true;
2065 }
2066
2067 // Return true if we know the node does not escape globally.
2068 bool ConnectionGraph::not_global_escape(Node *n) {
2069 assert(!_collecting, "should not call during graph construction");
2070 // If the node was created after the escape computation we can't answer.
2071 uint idx = n->_idx;
2072 if (idx >= nodes_size()) {
2073 return false;
2074 }
2075 PointsToNode* ptn = ptnode_adr(idx);
2076 PointsToNode::EscapeState es = ptn->escape_state();
2077 // If we have already computed a value, return it.
2078 if (es >= PointsToNode::GlobalEscape)
2079 return false;
2080 if (ptn->is_JavaObject()) {
2081 return true; // (es < PointsToNode::GlobalEscape);
2082 }
2083 assert(ptn->is_LocalVar(), "sanity");
2084 // Check all java objects it points to.
2085 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2086 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2087 return false;
2088 }
2089 return true;
2090 }
2091
2092
2093 // Helper functions
2094
2095 // Return true if this node points to specified node or nodes it points to.
2096 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2097 if (is_JavaObject()) {
2098 return (this == ptn);
2099 }
2100 assert(is_LocalVar() || is_Field(), "sanity");
2101 for (EdgeIterator i(this); i.has_next(); i.next()) {
2102 if (i.get() == ptn)
2103 return true;
2104 }
2105 return false;
2106 }
2107
2108 // Return true if one node points to an other.
2109 bool PointsToNode::meet(PointsToNode* ptn) {
2110 if (this == ptn) {
2111 return true;
2112 } else if (ptn->is_JavaObject()) {
2113 return this->points_to(ptn->as_JavaObject());
2114 } else if (this->is_JavaObject()) {
2115 return ptn->points_to(this->as_JavaObject());
2116 }
2117 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2118 int ptn_count = ptn->edge_count();
2119 for (EdgeIterator i(this); i.has_next(); i.next()) {
2120 PointsToNode* this_e = i.get();
2121 for (int j = 0; j < ptn_count; j++) {
2122 if (this_e == ptn->edge(j))
2123 return true;
2124 }
2125 }
2126 return false;
2127 }
2128
2129 #ifdef ASSERT
2130 // Return true if bases point to this java object.
2131 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2132 for (BaseIterator i(this); i.has_next(); i.next()) {
2133 if (i.get() == jobj)
2134 return true;
2135 }
2136 return false;
2137 }
2138 #endif
2139
2140 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2141 const Type *adr_type = phase->type(adr);
2142 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2143 adr->in(AddPNode::Address)->is_Proj() &&
2144 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2145 // We are computing a raw address for a store captured by an Initialize
2146 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2147 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2148 assert(offs != Type::OffsetBot ||
2149 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2150 "offset must be a constant or it is initialization of array");
2151 return offs;
2152 }
2153 const TypePtr *t_ptr = adr_type->isa_ptr();
2154 assert(t_ptr != NULL, "must be a pointer type");
2155 return t_ptr->offset();
2156 }
2157
2158 Node* ConnectionGraph::get_addp_base(Node *addp) {
2159 assert(addp->is_AddP(), "must be AddP");
2160 //
2161 // AddP cases for Base and Address inputs:
2162 // case #1. Direct object's field reference:
2163 // Allocate
2164 // |
2165 // Proj #5 ( oop result )
2166 // |
2167 // CheckCastPP (cast to instance type)
2168 // | |
2169 // AddP ( base == address )
2170 //
2171 // case #2. Indirect object's field reference:
2172 // Phi
2173 // |
2174 // CastPP (cast to instance type)
2175 // | |
2176 // AddP ( base == address )
2177 //
2178 // case #3. Raw object's field reference for Initialize node:
2179 // Allocate
2180 // |
2181 // Proj #5 ( oop result )
2182 // top |
2183 // \ |
2184 // AddP ( base == top )
2185 //
2186 // case #4. Array's element reference:
2187 // {CheckCastPP | CastPP}
2188 // | | |
2189 // | AddP ( array's element offset )
2190 // | |
2191 // AddP ( array's offset )
2192 //
2193 // case #5. Raw object's field reference for arraycopy stub call:
2194 // The inline_native_clone() case when the arraycopy stub is called
2195 // after the allocation before Initialize and CheckCastPP nodes.
2196 // Allocate
2197 // |
2198 // Proj #5 ( oop result )
2199 // | |
2200 // AddP ( base == address )
2201 //
2202 // case #6. Constant Pool, ThreadLocal, CastX2P or
2203 // Raw object's field reference:
2204 // {ConP, ThreadLocal, CastX2P, raw Load}
2205 // top |
2206 // \ |
2207 // AddP ( base == top )
2208 //
2209 // case #7. Klass's field reference.
2210 // LoadKlass
2211 // | |
2212 // AddP ( base == address )
2213 //
2214 // case #8. narrow Klass's field reference.
2215 // LoadNKlass
2216 // |
2217 // DecodeN
2218 // | |
2219 // AddP ( base == address )
2220 //
2221 Node *base = addp->in(AddPNode::Base);
2222 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2223 base = addp->in(AddPNode::Address);
2224 while (base->is_AddP()) {
2225 // Case #6 (unsafe access) may have several chained AddP nodes.
2226 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2227 base = base->in(AddPNode::Address);
2228 }
2229 Node* uncast_base = base->uncast();
2230 int opcode = uncast_base->Opcode();
2231 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2232 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2233 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2234 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2235 }
2236 return base;
2237 }
2238
2239 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2240 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2241 Node* addp2 = addp->raw_out(0);
2242 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2243 addp2->in(AddPNode::Base) == n &&
2244 addp2->in(AddPNode::Address) == addp) {
2245 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2246 //
2247 // Find array's offset to push it on worklist first and
2248 // as result process an array's element offset first (pushed second)
2249 // to avoid CastPP for the array's offset.
2250 // Otherwise the inserted CastPP (LocalVar) will point to what
2251 // the AddP (Field) points to. Which would be wrong since
2252 // the algorithm expects the CastPP has the same point as
2253 // as AddP's base CheckCastPP (LocalVar).
2254 //
2255 // ArrayAllocation
2256 // |
2257 // CheckCastPP
2258 // |
2259 // memProj (from ArrayAllocation CheckCastPP)
2260 // | ||
2261 // | || Int (element index)
2262 // | || | ConI (log(element size))
2263 // | || | /
2264 // | || LShift
2265 // | || /
2266 // | AddP (array's element offset)
2267 // | |
2268 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2269 // | / /
2270 // AddP (array's offset)
2271 // |
2272 // Load/Store (memory operation on array's element)
2273 //
2274 return addp2;
2275 }
2276 return NULL;
2277 }
2278
2279 //
2280 // Adjust the type and inputs of an AddP which computes the
2281 // address of a field of an instance
2282 //
2283 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2284 PhaseGVN* igvn = _igvn;
2285 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2286 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2287 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2288 if (t == NULL) {
2289 // We are computing a raw address for a store captured by an Initialize
2290 // compute an appropriate address type (cases #3 and #5).
2291 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2292 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2293 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2294 assert(offs != Type::OffsetBot, "offset must be a constant");
2295 t = base_t->add_offset(offs)->is_oopptr();
2296 }
2297 int inst_id = base_t->instance_id();
2298 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2299 "old type must be non-instance or match new type");
2300
2301 // The type 't' could be subclass of 'base_t'.
2302 // As result t->offset() could be large then base_t's size and it will
2303 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2304 // constructor verifies correctness of the offset.
2305 //
2306 // It could happened on subclass's branch (from the type profiling
2307 // inlining) which was not eliminated during parsing since the exactness
2308 // of the allocation type was not propagated to the subclass type check.
2309 //
2310 // Or the type 't' could be not related to 'base_t' at all.
2311 // It could happened when CHA type is different from MDO type on a dead path
2312 // (for example, from instanceof check) which is not collapsed during parsing.
2313 //
2314 // Do nothing for such AddP node and don't process its users since
2315 // this code branch will go away.
2316 //
2317 if (!t->is_known_instance() &&
2318 !base_t->klass()->is_subtype_of(t->klass())) {
2319 return false; // bail out
2320 }
2321 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2322 // Do NOT remove the next line: ensure a new alias index is allocated
2323 // for the instance type. Note: C++ will not remove it since the call
2324 // has side effect.
2325 int alias_idx = _compile->get_alias_index(tinst);
2326 igvn->set_type(addp, tinst);
2327 // record the allocation in the node map
2328 set_map(addp, get_map(base->_idx));
2329 // Set addp's Base and Address to 'base'.
2330 Node *abase = addp->in(AddPNode::Base);
2331 Node *adr = addp->in(AddPNode::Address);
2332 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2333 adr->in(0)->_idx == (uint)inst_id) {
2334 // Skip AddP cases #3 and #5.
2335 } else {
2336 assert(!abase->is_top(), "sanity"); // AddP case #3
2337 if (abase != base) {
2338 igvn->hash_delete(addp);
2339 addp->set_req(AddPNode::Base, base);
2340 if (abase == adr) {
2341 addp->set_req(AddPNode::Address, base);
2342 } else {
2343 // AddP case #4 (adr is array's element offset AddP node)
2344 #ifdef ASSERT
2345 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2346 assert(adr->is_AddP() && atype != NULL &&
2347 atype->instance_id() == inst_id, "array's element offset should be processed first");
2348 #endif
2349 }
2350 igvn->hash_insert(addp);
2351 }
2352 }
2353 // Put on IGVN worklist since at least addp's type was changed above.
2354 record_for_optimizer(addp);
2355 return true;
2356 }
2357
2358 //
2359 // Create a new version of orig_phi if necessary. Returns either the newly
2360 // created phi or an existing phi. Sets create_new to indicate whether a new
2361 // phi was created. Cache the last newly created phi in the node map.
2362 //
2363 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2364 Compile *C = _compile;
2365 PhaseGVN* igvn = _igvn;
2366 new_created = false;
2367 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2368 // nothing to do if orig_phi is bottom memory or matches alias_idx
2369 if (phi_alias_idx == alias_idx) {
2370 return orig_phi;
2371 }
2372 // Have we recently created a Phi for this alias index?
2373 PhiNode *result = get_map_phi(orig_phi->_idx);
2374 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2375 return result;
2376 }
2377 // Previous check may fail when the same wide memory Phi was split into Phis
2378 // for different memory slices. Search all Phis for this region.
2379 if (result != NULL) {
2380 Node* region = orig_phi->in(0);
2381 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2382 Node* phi = region->fast_out(i);
2383 if (phi->is_Phi() &&
2384 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2385 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2386 return phi->as_Phi();
2387 }
2388 }
2389 }
2390 if ((int) (C->live_nodes() + 2*NodeLimitFudgeFactor) > MaxNodeLimit) {
2391 if (C->do_escape_analysis() == true && !C->failing()) {
2392 // Retry compilation without escape analysis.
2393 // If this is the first failure, the sentinel string will "stick"
2394 // to the Compile object, and the C2Compiler will see it and retry.
2395 C->record_failure(C2Compiler::retry_no_escape_analysis());
2396 }
2397 return NULL;
2398 }
2399 orig_phi_worklist.append_if_missing(orig_phi);
2400 const TypePtr *atype = C->get_adr_type(alias_idx);
2401 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2402 C->copy_node_notes_to(result, orig_phi);
2403 igvn->set_type(result, result->bottom_type());
2404 record_for_optimizer(result);
2405 set_map(orig_phi, result);
2406 new_created = true;
2407 return result;
2408 }
2409
2410 //
2411 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2412 // specified alias index.
2413 //
2414 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2415 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2416 Compile *C = _compile;
2417 PhaseGVN* igvn = _igvn;
2418 bool new_phi_created;
2419 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2420 if (!new_phi_created) {
2421 return result;
2422 }
2423 GrowableArray<PhiNode *> phi_list;
2424 GrowableArray<uint> cur_input;
2425 PhiNode *phi = orig_phi;
2426 uint idx = 1;
2427 bool finished = false;
2428 while(!finished) {
2429 while (idx < phi->req()) {
2430 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2431 if (mem != NULL && mem->is_Phi()) {
2432 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2433 if (new_phi_created) {
2434 // found an phi for which we created a new split, push current one on worklist and begin
2435 // processing new one
2436 phi_list.push(phi);
2437 cur_input.push(idx);
2438 phi = mem->as_Phi();
2439 result = newphi;
2440 idx = 1;
2441 continue;
2442 } else {
2443 mem = newphi;
2444 }
2445 }
2446 if (C->failing()) {
2447 return NULL;
2448 }
2449 result->set_req(idx++, mem);
2450 }
2451 #ifdef ASSERT
2452 // verify that the new Phi has an input for each input of the original
2453 assert( phi->req() == result->req(), "must have same number of inputs.");
2454 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2455 #endif
2456 // Check if all new phi's inputs have specified alias index.
2457 // Otherwise use old phi.
2458 for (uint i = 1; i < phi->req(); i++) {
2459 Node* in = result->in(i);
2460 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2461 }
2462 // we have finished processing a Phi, see if there are any more to do
2463 finished = (phi_list.length() == 0 );
2464 if (!finished) {
2465 phi = phi_list.pop();
2466 idx = cur_input.pop();
2467 PhiNode *prev_result = get_map_phi(phi->_idx);
2468 prev_result->set_req(idx++, result);
2469 result = prev_result;
2470 }
2471 }
2472 return result;
2473 }
2474
2475 //
2476 // The next methods are derived from methods in MemNode.
2477 //
2478 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2479 Node *mem = mmem;
2480 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2481 // means an array I have not precisely typed yet. Do not do any
2482 // alias stuff with it any time soon.
2483 if (toop->base() != Type::AnyPtr &&
2484 !(toop->klass() != NULL &&
2485 toop->klass()->is_java_lang_Object() &&
2486 toop->offset() == Type::OffsetBot)) {
2487 mem = mmem->memory_at(alias_idx);
2488 // Update input if it is progress over what we have now
2489 }
2490 return mem;
2491 }
2492
2493 //
2494 // Move memory users to their memory slices.
2495 //
2496 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2497 Compile* C = _compile;
2498 PhaseGVN* igvn = _igvn;
2499 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2500 assert(tp != NULL, "ptr type");
2501 int alias_idx = C->get_alias_index(tp);
2502 int general_idx = C->get_general_index(alias_idx);
2503
2504 // Move users first
2505 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2506 Node* use = n->fast_out(i);
2507 if (use->is_MergeMem()) {
2508 MergeMemNode* mmem = use->as_MergeMem();
2509 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2510 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2511 continue; // Nothing to do
2512 }
2513 // Replace previous general reference to mem node.
2514 uint orig_uniq = C->unique();
2515 Node* m = find_inst_mem(n, general_idx, orig_phis);
2516 assert(orig_uniq == C->unique(), "no new nodes");
2517 mmem->set_memory_at(general_idx, m);
2518 --imax;
2519 --i;
2520 } else if (use->is_MemBar()) {
2521 assert(!use->is_Initialize(), "initializing stores should not be moved");
2522 if (use->req() > MemBarNode::Precedent &&
2523 use->in(MemBarNode::Precedent) == n) {
2524 // Don't move related membars.
2525 record_for_optimizer(use);
2526 continue;
2527 }
2528 tp = use->as_MemBar()->adr_type()->isa_ptr();
2529 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2530 alias_idx == general_idx) {
2531 continue; // Nothing to do
2532 }
2533 // Move to general memory slice.
2534 uint orig_uniq = C->unique();
2535 Node* m = find_inst_mem(n, general_idx, orig_phis);
2536 assert(orig_uniq == C->unique(), "no new nodes");
2537 igvn->hash_delete(use);
2538 imax -= use->replace_edge(n, m);
2539 igvn->hash_insert(use);
2540 record_for_optimizer(use);
2541 --i;
2542 #ifdef ASSERT
2543 } else if (use->is_Mem()) {
2544 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2545 // Don't move related cardmark.
2546 continue;
2547 }
2548 // Memory nodes should have new memory input.
2549 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2550 assert(tp != NULL, "ptr type");
2551 int idx = C->get_alias_index(tp);
2552 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2553 "Following memory nodes should have new memory input or be on the same memory slice");
2554 } else if (use->is_Phi()) {
2555 // Phi nodes should be split and moved already.
2556 tp = use->as_Phi()->adr_type()->isa_ptr();
2557 assert(tp != NULL, "ptr type");
2558 int idx = C->get_alias_index(tp);
2559 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2560 } else {
2561 use->dump();
2562 assert(false, "should not be here");
2563 #endif
2564 }
2565 }
2566 }
2567
2568 //
2569 // Search memory chain of "mem" to find a MemNode whose address
2570 // is the specified alias index.
2571 //
2572 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2573 if (orig_mem == NULL)
2574 return orig_mem;
2575 Compile* C = _compile;
2576 PhaseGVN* igvn = _igvn;
2577 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2578 bool is_instance = (toop != NULL) && toop->is_known_instance();
2579 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2580 Node *prev = NULL;
2581 Node *result = orig_mem;
2582 while (prev != result) {
2583 prev = result;
2584 if (result == start_mem)
2585 break; // hit one of our sentinels
2586 if (result->is_Mem()) {
2587 const Type *at = igvn->type(result->in(MemNode::Address));
2588 if (at == Type::TOP)
2589 break; // Dead
2590 assert (at->isa_ptr() != NULL, "pointer type required.");
2591 int idx = C->get_alias_index(at->is_ptr());
2592 if (idx == alias_idx)
2593 break; // Found
2594 if (!is_instance && (at->isa_oopptr() == NULL ||
2595 !at->is_oopptr()->is_known_instance())) {
2596 break; // Do not skip store to general memory slice.
2597 }
2598 result = result->in(MemNode::Memory);
2599 }
2600 if (!is_instance)
2601 continue; // don't search further for non-instance types
2602 // skip over a call which does not affect this memory slice
2603 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2604 Node *proj_in = result->in(0);
2605 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2606 break; // hit one of our sentinels
2607 } else if (proj_in->is_Call()) {
2608 CallNode *call = proj_in->as_Call();
2609 if (!call->may_modify(toop, igvn)) {
2610 result = call->in(TypeFunc::Memory);
2611 }
2612 } else if (proj_in->is_Initialize()) {
2613 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2614 // Stop if this is the initialization for the object instance which
2615 // which contains this memory slice, otherwise skip over it.
2616 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2617 result = proj_in->in(TypeFunc::Memory);
2618 }
2619 } else if (proj_in->is_MemBar()) {
2620 result = proj_in->in(TypeFunc::Memory);
2621 }
2622 } else if (result->is_MergeMem()) {
2623 MergeMemNode *mmem = result->as_MergeMem();
2624 result = step_through_mergemem(mmem, alias_idx, toop);
2625 if (result == mmem->base_memory()) {
2626 // Didn't find instance memory, search through general slice recursively.
2627 result = mmem->memory_at(C->get_general_index(alias_idx));
2628 result = find_inst_mem(result, alias_idx, orig_phis);
2629 if (C->failing()) {
2630 return NULL;
2631 }
2632 mmem->set_memory_at(alias_idx, result);
2633 }
2634 } else if (result->is_Phi() &&
2635 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2636 Node *un = result->as_Phi()->unique_input(igvn);
2637 if (un != NULL) {
2638 orig_phis.append_if_missing(result->as_Phi());
2639 result = un;
2640 } else {
2641 break;
2642 }
2643 } else if (result->is_ClearArray()) {
2644 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2645 // Can not bypass initialization of the instance
2646 // we are looking for.
2647 break;
2648 }
2649 // Otherwise skip it (the call updated 'result' value).
2650 } else if (result->Opcode() == Op_SCMemProj) {
2651 Node* mem = result->in(0);
2652 Node* adr = NULL;
2653 if (mem->is_LoadStore()) {
2654 adr = mem->in(MemNode::Address);
2655 } else {
2656 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2657 adr = mem->in(3); // Memory edge corresponds to destination array
2658 }
2659 const Type *at = igvn->type(adr);
2660 if (at != Type::TOP) {
2661 assert (at->isa_ptr() != NULL, "pointer type required.");
2662 int idx = C->get_alias_index(at->is_ptr());
2663 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2664 break;
2665 }
2666 result = mem->in(MemNode::Memory);
2667 }
2668 }
2669 if (result->is_Phi()) {
2670 PhiNode *mphi = result->as_Phi();
2671 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2672 const TypePtr *t = mphi->adr_type();
2673 if (!is_instance) {
2674 // Push all non-instance Phis on the orig_phis worklist to update inputs
2675 // during Phase 4 if needed.
2676 orig_phis.append_if_missing(mphi);
2677 } else if (C->get_alias_index(t) != alias_idx) {
2678 // Create a new Phi with the specified alias index type.
2679 result = split_memory_phi(mphi, alias_idx, orig_phis);
2680 }
2681 }
2682 // the result is either MemNode, PhiNode, InitializeNode.
2683 return result;
2684 }
2685
2686 //
2687 // Convert the types of unescaped object to instance types where possible,
2688 // propagate the new type information through the graph, and update memory
2689 // edges and MergeMem inputs to reflect the new type.
2690 //
2691 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2692 // The processing is done in 4 phases:
2693 //
2694 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2695 // types for the CheckCastPP for allocations where possible.
2696 // Propagate the the new types through users as follows:
2697 // casts and Phi: push users on alloc_worklist
2698 // AddP: cast Base and Address inputs to the instance type
2699 // push any AddP users on alloc_worklist and push any memnode
2700 // users onto memnode_worklist.
2701 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2702 // search the Memory chain for a store with the appropriate type
2703 // address type. If a Phi is found, create a new version with
2704 // the appropriate memory slices from each of the Phi inputs.
2705 // For stores, process the users as follows:
2706 // MemNode: push on memnode_worklist
2707 // MergeMem: push on mergemem_worklist
2708 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2709 // moving the first node encountered of each instance type to the
2710 // the input corresponding to its alias index.
2711 // appropriate memory slice.
2712 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2713 //
2714 // In the following example, the CheckCastPP nodes are the cast of allocation
2715 // results and the allocation of node 29 is unescaped and eligible to be an
2716 // instance type.
2717 //
2718 // We start with:
2719 //
2720 // 7 Parm #memory
2721 // 10 ConI "12"
2722 // 19 CheckCastPP "Foo"
2723 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2724 // 29 CheckCastPP "Foo"
2725 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2726 //
2727 // 40 StoreP 25 7 20 ... alias_index=4
2728 // 50 StoreP 35 40 30 ... alias_index=4
2729 // 60 StoreP 45 50 20 ... alias_index=4
2730 // 70 LoadP _ 60 30 ... alias_index=4
2731 // 80 Phi 75 50 60 Memory alias_index=4
2732 // 90 LoadP _ 80 30 ... alias_index=4
2733 // 100 LoadP _ 80 20 ... alias_index=4
2734 //
2735 //
2736 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2737 // and creating a new alias index for node 30. This gives:
2738 //
2739 // 7 Parm #memory
2740 // 10 ConI "12"
2741 // 19 CheckCastPP "Foo"
2742 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2743 // 29 CheckCastPP "Foo" iid=24
2744 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2745 //
2746 // 40 StoreP 25 7 20 ... alias_index=4
2747 // 50 StoreP 35 40 30 ... alias_index=6
2748 // 60 StoreP 45 50 20 ... alias_index=4
2749 // 70 LoadP _ 60 30 ... alias_index=6
2750 // 80 Phi 75 50 60 Memory alias_index=4
2751 // 90 LoadP _ 80 30 ... alias_index=6
2752 // 100 LoadP _ 80 20 ... alias_index=4
2753 //
2754 // In phase 2, new memory inputs are computed for the loads and stores,
2755 // And a new version of the phi is created. In phase 4, the inputs to
2756 // node 80 are updated and then the memory nodes are updated with the
2757 // values computed in phase 2. This results in:
2758 //
2759 // 7 Parm #memory
2760 // 10 ConI "12"
2761 // 19 CheckCastPP "Foo"
2762 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2763 // 29 CheckCastPP "Foo" iid=24
2764 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2765 //
2766 // 40 StoreP 25 7 20 ... alias_index=4
2767 // 50 StoreP 35 7 30 ... alias_index=6
2768 // 60 StoreP 45 40 20 ... alias_index=4
2769 // 70 LoadP _ 50 30 ... alias_index=6
2770 // 80 Phi 75 40 60 Memory alias_index=4
2771 // 120 Phi 75 50 50 Memory alias_index=6
2772 // 90 LoadP _ 120 30 ... alias_index=6
2773 // 100 LoadP _ 80 20 ... alias_index=4
2774 //
2775 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
2776 GrowableArray<Node *> memnode_worklist;
2777 GrowableArray<PhiNode *> orig_phis;
2778 PhaseIterGVN *igvn = _igvn;
2779 uint new_index_start = (uint) _compile->num_alias_types();
2780 Arena* arena = Thread::current()->resource_area();
2781 VectorSet visited(arena);
2782 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2783 uint unique_old = _compile->unique();
2784
2785 // Phase 1: Process possible allocations from alloc_worklist.
2786 // Create instance types for the CheckCastPP for allocations where possible.
2787 //
2788 // (Note: don't forget to change the order of the second AddP node on
2789 // the alloc_worklist if the order of the worklist processing is changed,
2790 // see the comment in find_second_addp().)
2791 //
2792 while (alloc_worklist.length() != 0) {
2793 Node *n = alloc_worklist.pop();
2794 uint ni = n->_idx;
2795 if (n->is_Call()) {
2796 CallNode *alloc = n->as_Call();
2797 // copy escape information to call node
2798 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2799 PointsToNode::EscapeState es = ptn->escape_state();
2800 // We have an allocation or call which returns a Java object,
2801 // see if it is unescaped.
2802 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2803 continue;
2804 // Find CheckCastPP for the allocate or for the return value of a call
2805 n = alloc->result_cast();
2806 if (n == NULL) { // No uses except Initialize node
2807 if (alloc->is_Allocate()) {
2808 // Set the scalar_replaceable flag for allocation
2809 // so it could be eliminated if it has no uses.
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 if it has no uses.
2815 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2816 }
2817 continue;
2818 }
2819 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2820 assert(!alloc->is_Allocate(), "allocation should have unique type");
2821 continue;
2822 }
2823
2824 // The inline code for Object.clone() casts the allocation result to
2825 // java.lang.Object and then to the actual type of the allocated
2826 // object. Detect this case and use the second cast.
2827 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2828 // the allocation result is cast to java.lang.Object and then
2829 // to the actual Array type.
2830 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2831 && (alloc->is_AllocateArray() ||
2832 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2833 Node *cast2 = NULL;
2834 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2835 Node *use = n->fast_out(i);
2836 if (use->is_CheckCastPP()) {
2837 cast2 = use;
2838 break;
2839 }
2840 }
2841 if (cast2 != NULL) {
2842 n = cast2;
2843 } else {
2844 // Non-scalar replaceable if the allocation type is unknown statically
2845 // (reflection allocation), the object can't be restored during
2846 // deoptimization without precise type.
2847 continue;
2848 }
2849 }
2850
2851 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2852 if (t == NULL)
2853 continue; // not a TypeOopPtr
2854 if (!t->klass_is_exact())
2855 continue; // not an unique type
2856
2857 if (alloc->is_Allocate()) {
2858 // Set the scalar_replaceable flag for allocation
2859 // so it could be eliminated.
2860 alloc->as_Allocate()->_is_scalar_replaceable = true;
2861 }
2862 if (alloc->is_CallStaticJava()) {
2863 // Set the scalar_replaceable flag for boxing method
2864 // so it could be eliminated.
2865 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2866 }
2867 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2868 // in order for an object to be scalar-replaceable, it must be:
2869 // - a direct allocation (not a call returning an object)
2870 // - non-escaping
2871 // - eligible to be a unique type
2872 // - not determined to be ineligible by escape analysis
2873 set_map(alloc, n);
2874 set_map(n, alloc);
2875 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2876 igvn->hash_delete(n);
2877 igvn->set_type(n, tinst);
2878 n->raise_bottom_type(tinst);
2879 igvn->hash_insert(n);
2880 record_for_optimizer(n);
2881 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2882
2883 // First, put on the worklist all Field edges from Connection Graph
2884 // which is more accurate then putting immediate users from Ideal Graph.
2885 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2886 PointsToNode* tgt = e.get();
2887 Node* use = tgt->ideal_node();
2888 assert(tgt->is_Field() && use->is_AddP(),
2889 "only AddP nodes are Field edges in CG");
2890 if (use->outcnt() > 0) { // Don't process dead nodes
2891 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2892 if (addp2 != NULL) {
2893 assert(alloc->is_AllocateArray(),"array allocation was expected");
2894 alloc_worklist.append_if_missing(addp2);
2895 }
2896 alloc_worklist.append_if_missing(use);
2897 }
2898 }
2899
2900 // An allocation may have an Initialize which has raw stores. Scan
2901 // the users of the raw allocation result and push AddP users
2902 // on alloc_worklist.
2903 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2904 assert (raw_result != NULL, "must have an allocation result");
2905 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2906 Node *use = raw_result->fast_out(i);
2907 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2908 Node* addp2 = find_second_addp(use, raw_result);
2909 if (addp2 != NULL) {
2910 assert(alloc->is_AllocateArray(),"array allocation was expected");
2911 alloc_worklist.append_if_missing(addp2);
2912 }
2913 alloc_worklist.append_if_missing(use);
2914 } else if (use->is_MemBar()) {
2915 memnode_worklist.append_if_missing(use);
2916 }
2917 }
2918 }
2919 } else if (n->is_AddP()) {
2920 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
2921 if (jobj == NULL || jobj == phantom_obj) {
2922 #ifdef ASSERT
2923 ptnode_adr(get_addp_base(n)->_idx)->dump();
2924 ptnode_adr(n->_idx)->dump();
2925 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2926 #endif
2927 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2928 return;
2929 }
2930 Node *base = get_map(jobj->idx()); // CheckCastPP node
2931 if (!split_AddP(n, base)) continue; // wrong type from dead path
2932 } else if (n->is_Phi() ||
2933 n->is_CheckCastPP() ||
2934 n->is_EncodeP() ||
2935 n->is_DecodeN() ||
2936 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
2937 if (visited.test_set(n->_idx)) {
2938 assert(n->is_Phi(), "loops only through Phi's");
2939 continue; // already processed
2940 }
2941 JavaObjectNode* jobj = unique_java_object(n);
2942 if (jobj == NULL || jobj == phantom_obj) {
2943 #ifdef ASSERT
2944 ptnode_adr(n->_idx)->dump();
2945 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
2946 #endif
2947 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
2948 return;
2949 } else {
2950 Node *val = get_map(jobj->idx()); // CheckCastPP node
2951 TypeNode *tn = n->as_Type();
2952 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
2953 assert(tinst != NULL && tinst->is_known_instance() &&
2954 tinst->instance_id() == jobj->idx() , "instance type expected.");
2955
2956 const Type *tn_type = igvn->type(tn);
2957 const TypeOopPtr *tn_t;
2958 if (tn_type->isa_narrowoop()) {
2959 tn_t = tn_type->make_ptr()->isa_oopptr();
2960 } else {
2961 tn_t = tn_type->isa_oopptr();
2962 }
2963 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
2964 if (tn_type->isa_narrowoop()) {
2965 tn_type = tinst->make_narrowoop();
2966 } else {
2967 tn_type = tinst;
2968 }
2969 igvn->hash_delete(tn);
2970 igvn->set_type(tn, tn_type);
2971 tn->set_type(tn_type);
2972 igvn->hash_insert(tn);
2973 record_for_optimizer(n);
2974 } else {
2975 assert(tn_type == TypePtr::NULL_PTR ||
2976 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
2977 "unexpected type");
2978 continue; // Skip dead path with different type
2979 }
2980 }
2981 } else {
2982 debug_only(n->dump();)
2983 assert(false, "EA: unexpected node");
2984 continue;
2985 }
2986 // push allocation's users on appropriate worklist
2987 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2988 Node *use = n->fast_out(i);
2989 if(use->is_Mem() && use->in(MemNode::Address) == n) {
2990 // Load/store to instance's field
2991 memnode_worklist.append_if_missing(use);
2992 } else if (use->is_MemBar()) {
2993 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
2994 memnode_worklist.append_if_missing(use);
2995 }
2996 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
2997 Node* addp2 = find_second_addp(use, n);
2998 if (addp2 != NULL) {
2999 alloc_worklist.append_if_missing(addp2);
3000 }
3001 alloc_worklist.append_if_missing(use);
3002 } else if (use->is_Phi() ||
3003 use->is_CheckCastPP() ||
3004 use->is_EncodeNarrowPtr() ||
3005 use->is_DecodeNarrowPtr() ||
3006 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3007 alloc_worklist.append_if_missing(use);
3008 #ifdef ASSERT
3009 } else if (use->is_Mem()) {
3010 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3011 } else if (use->is_MergeMem()) {
3012 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3013 } else if (use->is_SafePoint()) {
3014 // Look for MergeMem nodes for calls which reference unique allocation
3015 // (through CheckCastPP nodes) even for debug info.
3016 Node* m = use->in(TypeFunc::Memory);
3017 if (m->is_MergeMem()) {
3018 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3019 }
3020 } else if (use->Opcode() == Op_EncodeISOArray) {
3021 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3022 // EncodeISOArray overwrites destination array
3023 memnode_worklist.append_if_missing(use);
3024 }
3025 } else {
3026 uint op = use->Opcode();
3027 if (!(op == Op_CmpP || op == Op_Conv2B ||
3028 op == Op_CastP2X || op == Op_StoreCM ||
3029 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3030 op == Op_StrEquals || op == Op_StrIndexOf)) {
3031 n->dump();
3032 use->dump();
3033 assert(false, "EA: missing allocation reference path");
3034 }
3035 #endif
3036 }
3037 }
3038
3039 }
3040 // New alias types were created in split_AddP().
3041 uint new_index_end = (uint) _compile->num_alias_types();
3042 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3043
3044 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3045 // compute new values for Memory inputs (the Memory inputs are not
3046 // actually updated until phase 4.)
3047 if (memnode_worklist.length() == 0)
3048 return; // nothing to do
3049 while (memnode_worklist.length() != 0) {
3050 Node *n = memnode_worklist.pop();
3051 if (visited.test_set(n->_idx))
3052 continue;
3053 if (n->is_Phi() || n->is_ClearArray()) {
3054 // we don't need to do anything, but the users must be pushed
3055 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3056 // we don't need to do anything, but the users must be pushed
3057 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3058 if (n == NULL)
3059 continue;
3060 } else if (n->Opcode() == Op_EncodeISOArray) {
3061 // get the memory projection
3062 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3063 Node *use = n->fast_out(i);
3064 if (use->Opcode() == Op_SCMemProj) {
3065 n = use;
3066 break;
3067 }
3068 }
3069 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3070 } else {
3071 assert(n->is_Mem(), "memory node required.");
3072 Node *addr = n->in(MemNode::Address);
3073 const Type *addr_t = igvn->type(addr);
3074 if (addr_t == Type::TOP)
3075 continue;
3076 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3077 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3078 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3079 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3080 if (_compile->failing()) {
3081 return;
3082 }
3083 if (mem != n->in(MemNode::Memory)) {
3084 // We delay the memory edge update since we need old one in
3085 // MergeMem code below when instances memory slices are separated.
3086 set_map(n, mem);
3087 }
3088 if (n->is_Load()) {
3089 continue; // don't push users
3090 } else if (n->is_LoadStore()) {
3091 // get the memory projection
3092 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3093 Node *use = n->fast_out(i);
3094 if (use->Opcode() == Op_SCMemProj) {
3095 n = use;
3096 break;
3097 }
3098 }
3099 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3100 }
3101 }
3102 // push user on appropriate worklist
3103 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3104 Node *use = n->fast_out(i);
3105 if (use->is_Phi() || use->is_ClearArray()) {
3106 memnode_worklist.append_if_missing(use);
3107 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3108 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3109 continue;
3110 memnode_worklist.append_if_missing(use);
3111 } else if (use->is_MemBar()) {
3112 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3113 memnode_worklist.append_if_missing(use);
3114 }
3115 #ifdef ASSERT
3116 } else if(use->is_Mem()) {
3117 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3118 } else if (use->is_MergeMem()) {
3119 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3120 } else if (use->Opcode() == Op_EncodeISOArray) {
3121 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3122 // EncodeISOArray overwrites destination array
3123 memnode_worklist.append_if_missing(use);
3124 }
3125 } else {
3126 uint op = use->Opcode();
3127 if (!(op == Op_StoreCM ||
3128 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3129 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3130 op == Op_AryEq || op == Op_StrComp ||
3131 op == Op_StrEquals || op == Op_StrIndexOf)) {
3132 n->dump();
3133 use->dump();
3134 assert(false, "EA: missing memory path");
3135 }
3136 #endif
3137 }
3138 }
3139 }
3140
3141 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3142 // Walk each memory slice moving the first node encountered of each
3143 // instance type to the the input corresponding to its alias index.
3144 uint length = _mergemem_worklist.length();
3145 for( uint next = 0; next < length; ++next ) {
3146 MergeMemNode* nmm = _mergemem_worklist.at(next);
3147 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3148 // Note: we don't want to use MergeMemStream here because we only want to
3149 // scan inputs which exist at the start, not ones we add during processing.
3150 // Note 2: MergeMem may already contains instance memory slices added
3151 // during find_inst_mem() call when memory nodes were processed above.
3152 igvn->hash_delete(nmm);
3153 uint nslices = nmm->req();
3154 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3155 Node* mem = nmm->in(i);
3156 Node* cur = NULL;
3157 if (mem == NULL || mem->is_top())
3158 continue;
3159 // First, update mergemem by moving memory nodes to corresponding slices
3160 // if their type became more precise since this mergemem was created.
3161 while (mem->is_Mem()) {
3162 const Type *at = igvn->type(mem->in(MemNode::Address));
3163 if (at != Type::TOP) {
3164 assert (at->isa_ptr() != NULL, "pointer type required.");
3165 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3166 if (idx == i) {
3167 if (cur == NULL)
3168 cur = mem;
3169 } else {
3170 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3171 nmm->set_memory_at(idx, mem);
3172 }
3173 }
3174 }
3175 mem = mem->in(MemNode::Memory);
3176 }
3177 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3178 // Find any instance of the current type if we haven't encountered
3179 // already a memory slice of the instance along the memory chain.
3180 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3181 if((uint)_compile->get_general_index(ni) == i) {
3182 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3183 if (nmm->is_empty_memory(m)) {
3184 Node* result = find_inst_mem(mem, ni, orig_phis);
3185 if (_compile->failing()) {
3186 return;
3187 }
3188 nmm->set_memory_at(ni, result);
3189 }
3190 }
3191 }
3192 }
3193 // Find the rest of instances values
3194 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3195 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3196 Node* result = step_through_mergemem(nmm, ni, tinst);
3197 if (result == nmm->base_memory()) {
3198 // Didn't find instance memory, search through general slice recursively.
3199 result = nmm->memory_at(_compile->get_general_index(ni));
3200 result = find_inst_mem(result, ni, orig_phis);
3201 if (_compile->failing()) {
3202 return;
3203 }
3204 nmm->set_memory_at(ni, result);
3205 }
3206 }
3207 igvn->hash_insert(nmm);
3208 record_for_optimizer(nmm);
3209 }
3210
3211 // Phase 4: Update the inputs of non-instance memory Phis and
3212 // the Memory input of memnodes
3213 // First update the inputs of any non-instance Phi's from
3214 // which we split out an instance Phi. Note we don't have
3215 // to recursively process Phi's encounted on the input memory
3216 // chains as is done in split_memory_phi() since they will
3217 // also be processed here.
3218 for (int j = 0; j < orig_phis.length(); j++) {
3219 PhiNode *phi = orig_phis.at(j);
3220 int alias_idx = _compile->get_alias_index(phi->adr_type());
3221 igvn->hash_delete(phi);
3222 for (uint i = 1; i < phi->req(); i++) {
3223 Node *mem = phi->in(i);
3224 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3225 if (_compile->failing()) {
3226 return;
3227 }
3228 if (mem != new_mem) {
3229 phi->set_req(i, new_mem);
3230 }
3231 }
3232 igvn->hash_insert(phi);
3233 record_for_optimizer(phi);
3234 }
3235
3236 // Update the memory inputs of MemNodes with the value we computed
3237 // in Phase 2 and move stores memory users to corresponding memory slices.
3238 // Disable memory split verification code until the fix for 6984348.
3239 // Currently it produces false negative results since it does not cover all cases.
3240 #if 0 // ifdef ASSERT
3241 visited.Reset();
3242 Node_Stack old_mems(arena, _compile->unique() >> 2);
3243 #endif
3244 for (uint i = 0; i < ideal_nodes.size(); i++) {
3245 Node* n = ideal_nodes.at(i);
3246 Node* nmem = get_map(n->_idx);
3247 assert(nmem != NULL, "sanity");
3248 if (n->is_Mem()) {
3249 #if 0 // ifdef ASSERT
3250 Node* old_mem = n->in(MemNode::Memory);
3251 if (!visited.test_set(old_mem->_idx)) {
3252 old_mems.push(old_mem, old_mem->outcnt());
3253 }
3254 #endif
3255 assert(n->in(MemNode::Memory) != nmem, "sanity");
3256 if (!n->is_Load()) {
3257 // Move memory users of a store first.
3258 move_inst_mem(n, orig_phis);
3259 }
3260 // Now update memory input
3261 igvn->hash_delete(n);
3262 n->set_req(MemNode::Memory, nmem);
3263 igvn->hash_insert(n);
3264 record_for_optimizer(n);
3265 } else {
3266 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3267 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3268 }
3269 }
3270 #if 0 // ifdef ASSERT
3271 // Verify that memory was split correctly
3272 while (old_mems.is_nonempty()) {
3273 Node* old_mem = old_mems.node();
3274 uint old_cnt = old_mems.index();
3275 old_mems.pop();
3276 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3277 }
3278 #endif
3279 }
3280
3281 #ifndef PRODUCT
3282 static const char *node_type_names[] = {
3283 "UnknownType",
3284 "JavaObject",
3285 "LocalVar",
3286 "Field",
3287 "Arraycopy"
3288 };
3289
3290 static const char *esc_names[] = {
3291 "UnknownEscape",
3292 "NoEscape",
3293 "ArgEscape",
3294 "GlobalEscape"
3295 };
3296
3297 void PointsToNode::dump(bool print_state) const {
3298 NodeType nt = node_type();
3299 tty->print("%s ", node_type_names[(int) nt]);
3300 if (print_state) {
3301 EscapeState es = escape_state();
3302 EscapeState fields_es = fields_escape_state();
3303 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3304 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3305 tty->print("NSR ");
3306 }
3307 if (is_Field()) {
3308 FieldNode* f = (FieldNode*)this;
3309 if (f->is_oop())
3310 tty->print("oop ");
3311 if (f->offset() > 0)
3312 tty->print("+%d ", f->offset());
3313 tty->print("(");
3314 for (BaseIterator i(f); i.has_next(); i.next()) {
3315 PointsToNode* b = i.get();
3316 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3317 }
3318 tty->print(" )");
3319 }
3320 tty->print("[");
3321 for (EdgeIterator i(this); i.has_next(); i.next()) {
3322 PointsToNode* e = i.get();
3323 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3324 }
3325 tty->print(" [");
3326 for (UseIterator i(this); i.has_next(); i.next()) {
3327 PointsToNode* u = i.get();
3328 bool is_base = false;
3329 if (PointsToNode::is_base_use(u)) {
3330 is_base = true;
3331 u = PointsToNode::get_use_node(u)->as_Field();
3332 }
3333 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3334 }
3335 tty->print(" ]] ");
3336 if (_node == NULL)
3337 tty->print_cr("<null>");
3338 else
3339 _node->dump();
3340 }
3341
3342 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3343 bool first = true;
3344 int ptnodes_length = ptnodes_worklist.length();
3345 for (int i = 0; i < ptnodes_length; i++) {
3346 PointsToNode *ptn = ptnodes_worklist.at(i);
3347 if (ptn == NULL || !ptn->is_JavaObject())
3348 continue;
3349 PointsToNode::EscapeState es = ptn->escape_state();
3350 if ((es != PointsToNode::NoEscape) && !Verbose) {
3351 continue;
3352 }
3353 Node* n = ptn->ideal_node();
3354 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3355 n->as_CallStaticJava()->is_boxing_method())) {
3356 if (first) {
3357 tty->cr();
3358 tty->print("======== Connection graph for ");
3359 _compile->method()->print_short_name();
3360 tty->cr();
3361 first = false;
3362 }
3363 ptn->dump();
3364 // Print all locals and fields which reference this allocation
3365 for (UseIterator j(ptn); j.has_next(); j.next()) {
3366 PointsToNode* use = j.get();
3367 if (use->is_LocalVar()) {
3368 use->dump(Verbose);
3369 } else if (Verbose) {
3370 use->dump();
3371 }
3372 }
3373 tty->cr();
3374 }
3375 }
3376 }
3377 #endif