1 /*
2 * Copyright (c) 2005, 2015, 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/arraycopynode.hpp"
32 #include "opto/callnode.hpp"
33 #include "opto/cfgnode.hpp"
34 #include "opto/compile.hpp"
35 #include "opto/escape.hpp"
36 #include "opto/phaseX.hpp"
37 #include "opto/movenode.hpp"
38 #include "opto/rootnode.hpp"
39
40 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
41 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
42 _in_worklist(C->comp_arena()),
43 _next_pidx(0),
44 _collecting(true),
45 _verify(false),
46 _compile(C),
47 _igvn(igvn),
48 _node_map(C->comp_arena()) {
49 // Add unknown java object.
50 add_java_object(C->top(), PointsToNode::GlobalEscape);
51 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
52 // Add ConP(#NULL) and ConN(#NULL) nodes.
53 Node* oop_null = igvn->zerocon(T_OBJECT);
54 assert(oop_null->_idx < nodes_size(), "should be created already");
55 add_java_object(oop_null, PointsToNode::NoEscape);
56 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
57 if (UseCompressedOops) {
58 Node* noop_null = igvn->zerocon(T_NARROWOOP);
59 assert(noop_null->_idx < nodes_size(), "should be created already");
60 map_ideal_node(noop_null, null_obj);
61 }
62 _pcmp_neq = NULL; // Should be initialized
63 _pcmp_eq = NULL;
64 }
65
66 bool ConnectionGraph::has_candidates(Compile *C) {
67 // EA brings benefits only when the code has allocations and/or locks which
68 // are represented by ideal Macro nodes.
69 int cnt = C->macro_count();
70 for (int i = 0; i < cnt; i++) {
71 Node *n = C->macro_node(i);
72 if (n->is_Allocate())
73 return true;
74 if (n->is_Lock()) {
75 Node* obj = n->as_Lock()->obj_node()->uncast();
76 if (!(obj->is_Parm() || obj->is_Con()))
77 return true;
78 }
79 if (n->is_CallStaticJava() &&
80 n->as_CallStaticJava()->is_boxing_method()) {
81 return true;
82 }
83 }
84 return false;
85 }
86
87 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
88 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
89 ResourceMark rm;
90
91 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
92 // to create space for them in ConnectionGraph::_nodes[].
93 Node* oop_null = igvn->zerocon(T_OBJECT);
94 Node* noop_null = igvn->zerocon(T_NARROWOOP);
95 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
96 // Perform escape analysis
97 if (congraph->compute_escape()) {
98 // There are non escaping objects.
99 C->set_congraph(congraph);
100 }
101 // Cleanup.
102 if (oop_null->outcnt() == 0)
103 igvn->hash_delete(oop_null);
104 if (noop_null->outcnt() == 0)
105 igvn->hash_delete(noop_null);
106 }
107
108 bool ConnectionGraph::compute_escape() {
109 Compile* C = _compile;
110 PhaseGVN* igvn = _igvn;
111
112 // Worklists used by EA.
113 Unique_Node_List delayed_worklist;
114 GrowableArray<Node*> alloc_worklist;
115 GrowableArray<Node*> ptr_cmp_worklist;
116 GrowableArray<Node*> storestore_worklist;
117 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
118 GrowableArray<PointsToNode*> ptnodes_worklist;
119 GrowableArray<JavaObjectNode*> java_objects_worklist;
120 GrowableArray<JavaObjectNode*> non_escaped_worklist;
121 GrowableArray<FieldNode*> oop_fields_worklist;
122 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
123
124 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
125
126 // 1. Populate Connection Graph (CG) with PointsTo nodes.
127 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
128 // Initialize worklist
129 if (C->root() != NULL) {
130 ideal_nodes.push(C->root());
131 }
132 // Processed ideal nodes are unique on ideal_nodes list
133 // but several ideal nodes are mapped to the phantom_obj.
134 // To avoid duplicated entries on the following worklists
135 // add the phantom_obj only once to them.
136 ptnodes_worklist.append(phantom_obj);
137 java_objects_worklist.append(phantom_obj);
138 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
139 Node* n = ideal_nodes.at(next);
140 // Create PointsTo nodes and add them to Connection Graph. Called
141 // only once per ideal node since ideal_nodes is Unique_Node list.
142 add_node_to_connection_graph(n, &delayed_worklist);
143 PointsToNode* ptn = ptnode_adr(n->_idx);
144 if (ptn != NULL && ptn != phantom_obj) {
145 ptnodes_worklist.append(ptn);
146 if (ptn->is_JavaObject()) {
147 java_objects_worklist.append(ptn->as_JavaObject());
148 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
149 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
150 // Only allocations and java static calls results are interesting.
151 non_escaped_worklist.append(ptn->as_JavaObject());
152 }
153 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
154 oop_fields_worklist.append(ptn->as_Field());
155 }
156 }
157 if (n->is_MergeMem()) {
158 // Collect all MergeMem nodes to add memory slices for
159 // scalar replaceable objects in split_unique_types().
160 _mergemem_worklist.append(n->as_MergeMem());
161 } else if (OptimizePtrCompare && n->is_Cmp() &&
162 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
163 // Collect compare pointers nodes.
164 ptr_cmp_worklist.append(n);
165 } else if (n->is_MemBarStoreStore()) {
166 // Collect all MemBarStoreStore nodes so that depending on the
167 // escape status of the associated Allocate node some of them
168 // may be eliminated.
169 storestore_worklist.append(n);
170 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
171 (n->req() > MemBarNode::Precedent)) {
172 record_for_optimizer(n);
173 #ifdef ASSERT
174 } else if (n->is_AddP()) {
175 // Collect address nodes for graph verification.
176 addp_worklist.append(n);
177 #endif
178 } else if (n->is_ArrayCopy()) {
179 // Keep a list of ArrayCopy nodes so if one of its input is non
180 // escaping, we can record a unique type
181 arraycopy_worklist.append(n->as_ArrayCopy());
182 }
183 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
184 Node* m = n->fast_out(i); // Get user
185 ideal_nodes.push(m);
186 }
187 }
188 if (non_escaped_worklist.length() == 0) {
189 _collecting = false;
190 return false; // Nothing to do.
191 }
192 // Add final simple edges to graph.
193 while(delayed_worklist.size() > 0) {
194 Node* n = delayed_worklist.pop();
195 add_final_edges(n);
196 }
197 int ptnodes_length = ptnodes_worklist.length();
198
199 #ifdef ASSERT
200 if (VerifyConnectionGraph) {
201 // Verify that no new simple edges could be created and all
202 // local vars has edges.
203 _verify = true;
204 for (int next = 0; next < ptnodes_length; ++next) {
205 PointsToNode* ptn = ptnodes_worklist.at(next);
206 add_final_edges(ptn->ideal_node());
207 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
208 ptn->dump();
209 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
210 }
211 }
212 _verify = false;
213 }
214 #endif
215 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
216 // processing, calls to CI to resolve symbols (types, fields, methods)
217 // referenced in bytecode. During symbol resolution VM may throw
218 // an exception which CI cleans and converts to compilation failure.
219 if (C->failing()) return false;
220
221 // 2. Finish Graph construction by propagating references to all
222 // java objects through graph.
223 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
224 java_objects_worklist, oop_fields_worklist)) {
225 // All objects escaped or hit time or iterations limits.
226 _collecting = false;
227 return false;
228 }
229
230 // 3. Adjust scalar_replaceable state of nonescaping objects and push
231 // scalar replaceable allocations on alloc_worklist for processing
232 // in split_unique_types().
233 int non_escaped_length = non_escaped_worklist.length();
234 for (int next = 0; next < non_escaped_length; next++) {
235 JavaObjectNode* ptn = non_escaped_worklist.at(next);
236 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
237 Node* n = ptn->ideal_node();
238 if (n->is_Allocate()) {
239 n->as_Allocate()->_is_non_escaping = noescape;
240 }
241 if (n->is_CallStaticJava()) {
242 n->as_CallStaticJava()->_is_non_escaping = noescape;
243 }
244 if (noescape && ptn->scalar_replaceable()) {
245 adjust_scalar_replaceable_state(ptn);
246 if (ptn->scalar_replaceable()) {
247 alloc_worklist.append(ptn->ideal_node());
248 }
249 }
250 }
251
252 #ifdef ASSERT
253 if (VerifyConnectionGraph) {
254 // Verify that graph is complete - no new edges could be added or needed.
255 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
256 java_objects_worklist, addp_worklist);
257 }
258 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
259 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
260 null_obj->edge_count() == 0 &&
261 !null_obj->arraycopy_src() &&
262 !null_obj->arraycopy_dst(), "sanity");
263 #endif
264
265 _collecting = false;
266
267 } // TracePhase t3("connectionGraph")
268
269 // 4. Optimize ideal graph based on EA information.
270 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
271 if (has_non_escaping_obj) {
272 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
273 }
274
275 #ifndef PRODUCT
276 if (PrintEscapeAnalysis) {
277 dump(ptnodes_worklist); // Dump ConnectionGraph
278 }
279 #endif
280
281 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
282 #ifdef ASSERT
283 if (VerifyConnectionGraph) {
284 int alloc_length = alloc_worklist.length();
285 for (int next = 0; next < alloc_length; ++next) {
286 Node* n = alloc_worklist.at(next);
287 PointsToNode* ptn = ptnode_adr(n->_idx);
288 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
289 }
290 }
291 #endif
292
293 // 5. Separate memory graph for scalar replaceable allcations.
294 if (has_scalar_replaceable_candidates &&
295 C->AliasLevel() >= 3 && EliminateAllocations) {
296 // Now use the escape information to create unique types for
297 // scalar replaceable objects.
298 split_unique_types(alloc_worklist, arraycopy_worklist);
299 if (C->failing()) return false;
300 C->print_method(PHASE_AFTER_EA, 2);
301
302 #ifdef ASSERT
303 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
304 tty->print("=== No allocations eliminated for ");
305 C->method()->print_short_name();
306 if(!EliminateAllocations) {
307 tty->print(" since EliminateAllocations is off ===");
308 } else if(!has_scalar_replaceable_candidates) {
309 tty->print(" since there are no scalar replaceable candidates ===");
310 } else if(C->AliasLevel() < 3) {
311 tty->print(" since AliasLevel < 3 ===");
312 }
313 tty->cr();
314 #endif
315 }
316 return has_non_escaping_obj;
317 }
318
319 // Utility function for nodes that load an object
320 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
321 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
322 // ThreadLocal has RawPtr type.
323 const Type* t = _igvn->type(n);
324 if (t->make_ptr() != NULL) {
325 Node* adr = n->in(MemNode::Address);
326 #ifdef ASSERT
327 if (!adr->is_AddP()) {
328 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
329 } else {
330 assert((ptnode_adr(adr->_idx) == NULL ||
331 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
332 }
333 #endif
334 add_local_var_and_edge(n, PointsToNode::NoEscape,
335 adr, delayed_worklist);
336 }
337 }
338
339 // Populate Connection Graph with PointsTo nodes and create simple
340 // connection graph edges.
341 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
342 assert(!_verify, "this method should not be called for verification");
343 PhaseGVN* igvn = _igvn;
344 uint n_idx = n->_idx;
345 PointsToNode* n_ptn = ptnode_adr(n_idx);
346 if (n_ptn != NULL)
347 return; // No need to redefine PointsTo node during first iteration.
348
349 if (n->is_Call()) {
350 // Arguments to allocation and locking don't escape.
351 if (n->is_AbstractLock()) {
352 // Put Lock and Unlock nodes on IGVN worklist to process them during
353 // first IGVN optimization when escape information is still available.
354 record_for_optimizer(n);
355 } else if (n->is_Allocate()) {
356 add_call_node(n->as_Call());
357 record_for_optimizer(n);
358 } else {
359 if (n->is_CallStaticJava()) {
360 const char* name = n->as_CallStaticJava()->_name;
361 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
362 return; // Skip uncommon traps
363 }
364 // Don't mark as processed since call's arguments have to be processed.
365 delayed_worklist->push(n);
366 // Check if a call returns an object.
367 if ((n->as_Call()->returns_pointer() &&
368 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
369 (n->is_CallStaticJava() &&
370 n->as_CallStaticJava()->is_boxing_method())) {
371 add_call_node(n->as_Call());
372 }
373 }
374 return;
375 }
376 // Put this check here to process call arguments since some call nodes
377 // point to phantom_obj.
378 if (n_ptn == phantom_obj || n_ptn == null_obj)
379 return; // Skip predefined nodes.
380
381 int opcode = n->Opcode();
382 switch (opcode) {
383 case Op_AddP: {
384 Node* base = get_addp_base(n);
385 PointsToNode* ptn_base = ptnode_adr(base->_idx);
386 // Field nodes are created for all field types. They are used in
387 // adjust_scalar_replaceable_state() and split_unique_types().
388 // Note, non-oop fields will have only base edges in Connection
389 // Graph because such fields are not used for oop loads and stores.
390 int offset = address_offset(n, igvn);
391 add_field(n, PointsToNode::NoEscape, offset);
392 if (ptn_base == NULL) {
393 delayed_worklist->push(n); // Process it later.
394 } else {
395 n_ptn = ptnode_adr(n_idx);
396 add_base(n_ptn->as_Field(), ptn_base);
397 }
398 break;
399 }
400 case Op_CastX2P: {
401 map_ideal_node(n, phantom_obj);
402 break;
403 }
404 case Op_CastPP:
405 case Op_CheckCastPP:
406 case Op_EncodeP:
407 case Op_DecodeN:
408 case Op_EncodePKlass:
409 case Op_DecodeNKlass: {
410 add_local_var_and_edge(n, PointsToNode::NoEscape,
411 n->in(1), delayed_worklist);
412 break;
413 }
414 case Op_CMoveP: {
415 add_local_var(n, PointsToNode::NoEscape);
416 // Do not add edges during first iteration because some could be
417 // not defined yet.
418 delayed_worklist->push(n);
419 break;
420 }
421 case Op_ConP:
422 case Op_ConN:
423 case Op_ConNKlass: {
424 // assume all oop constants globally escape except for null
425 PointsToNode::EscapeState es;
426 const Type* t = igvn->type(n);
427 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
428 es = PointsToNode::NoEscape;
429 } else {
430 es = PointsToNode::GlobalEscape;
431 }
432 add_java_object(n, es);
433 break;
434 }
435 case Op_CreateEx: {
436 // assume that all exception objects globally escape
437 map_ideal_node(n, phantom_obj);
438 break;
439 }
440 case Op_LoadKlass:
441 case Op_LoadNKlass: {
442 // Unknown class is loaded
443 map_ideal_node(n, phantom_obj);
444 break;
445 }
446 case Op_LoadP:
447 case Op_LoadN:
448 case Op_LoadPLocked: {
449 add_objload_to_connection_graph(n, delayed_worklist);
450 break;
451 }
452 case Op_Parm: {
453 map_ideal_node(n, phantom_obj);
454 break;
455 }
456 case Op_PartialSubtypeCheck: {
457 // Produces Null or notNull and is used in only in CmpP so
458 // phantom_obj could be used.
459 map_ideal_node(n, phantom_obj); // Result is unknown
460 break;
461 }
462 case Op_Phi: {
463 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
464 // ThreadLocal has RawPtr type.
465 const Type* t = n->as_Phi()->type();
466 if (t->make_ptr() != NULL) {
467 add_local_var(n, PointsToNode::NoEscape);
468 // Do not add edges during first iteration because some could be
469 // not defined yet.
470 delayed_worklist->push(n);
471 }
472 break;
473 }
474 case Op_Proj: {
475 // we are only interested in the oop result projection from a call
476 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
477 n->in(0)->as_Call()->returns_pointer()) {
478 add_local_var_and_edge(n, PointsToNode::NoEscape,
479 n->in(0), delayed_worklist);
480 }
481 break;
482 }
483 case Op_Rethrow: // Exception object escapes
484 case Op_Return: {
485 if (n->req() > TypeFunc::Parms &&
486 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
487 // Treat Return value as LocalVar with GlobalEscape escape state.
488 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
489 n->in(TypeFunc::Parms), delayed_worklist);
490 }
491 break;
492 }
493 case Op_CompareAndExchangeP:
494 case Op_CompareAndExchangeN:
495 case Op_GetAndSetP:
496 case Op_GetAndSetN: {
497 add_objload_to_connection_graph(n, delayed_worklist);
498 // fallthrough
499 }
500 case Op_StoreP:
501 case Op_StoreN:
502 case Op_StoreNKlass:
503 case Op_StorePConditional:
504 case Op_WeakCompareAndSwapP:
505 case Op_WeakCompareAndSwapN:
506 case Op_CompareAndSwapP:
507 case Op_CompareAndSwapN: {
508 Node* adr = n->in(MemNode::Address);
509 const Type *adr_type = igvn->type(adr);
510 adr_type = adr_type->make_ptr();
511 if (adr_type == NULL) {
512 break; // skip dead nodes
513 }
514 if (adr_type->isa_oopptr() ||
515 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
516 (adr_type == TypeRawPtr::NOTNULL &&
517 adr->in(AddPNode::Address)->is_Proj() &&
518 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
519 delayed_worklist->push(n); // Process it later.
520 #ifdef ASSERT
521 assert(adr->is_AddP(), "expecting an AddP");
522 if (adr_type == TypeRawPtr::NOTNULL) {
523 // Verify a raw address for a store captured by Initialize node.
524 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
525 assert(offs != Type::OffsetBot, "offset must be a constant");
526 }
527 #endif
528 } else {
529 // Ignore copy the displaced header to the BoxNode (OSR compilation).
530 if (adr->is_BoxLock())
531 break;
532 // Stored value escapes in unsafe access.
533 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
534 // Pointer stores in G1 barriers looks like unsafe access.
535 // Ignore such stores to be able scalar replace non-escaping
536 // allocations.
537 if (UseG1GC && adr->is_AddP()) {
538 Node* base = get_addp_base(adr);
539 if (base->Opcode() == Op_LoadP &&
540 base->in(MemNode::Address)->is_AddP()) {
541 adr = base->in(MemNode::Address);
542 Node* tls = get_addp_base(adr);
543 if (tls->Opcode() == Op_ThreadLocal) {
544 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
545 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
546 SATBMarkQueue::byte_offset_of_buf())) {
547 break; // G1 pre barrier previous oop value store.
548 }
549 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
550 DirtyCardQueue::byte_offset_of_buf())) {
551 break; // G1 post barrier card address store.
552 }
553 }
554 }
555 }
556 delayed_worklist->push(n); // Process unsafe access later.
557 break;
558 }
559 #ifdef ASSERT
560 n->dump(1);
561 assert(false, "not unsafe or G1 barrier raw StoreP");
562 #endif
563 }
564 break;
565 }
566 case Op_AryEq:
567 case Op_HasNegatives:
568 case Op_StrComp:
569 case Op_StrEquals:
570 case Op_StrIndexOf:
571 case Op_StrIndexOfChar:
572 case Op_StrInflatedCopy:
573 case Op_StrCompressedCopy:
574 case Op_EncodeISOArray: {
575 add_local_var(n, PointsToNode::ArgEscape);
576 delayed_worklist->push(n); // Process it later.
577 break;
578 }
579 case Op_ThreadLocal: {
580 add_java_object(n, PointsToNode::ArgEscape);
581 break;
582 }
583 default:
584 ; // Do nothing for nodes not related to EA.
585 }
586 return;
587 }
588
589 #ifdef ASSERT
590 #define ELSE_FAIL(name) \
591 /* Should not be called for not pointer type. */ \
592 n->dump(1); \
593 assert(false, name); \
594 break;
595 #else
596 #define ELSE_FAIL(name) \
597 break;
598 #endif
599
600 // Add final simple edges to graph.
601 void ConnectionGraph::add_final_edges(Node *n) {
602 PointsToNode* n_ptn = ptnode_adr(n->_idx);
603 #ifdef ASSERT
604 if (_verify && n_ptn->is_JavaObject())
605 return; // This method does not change graph for JavaObject.
606 #endif
607
608 if (n->is_Call()) {
609 process_call_arguments(n->as_Call());
610 return;
611 }
612 assert(n->is_Store() || n->is_LoadStore() ||
613 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
614 "node should be registered already");
615 int opcode = n->Opcode();
616 switch (opcode) {
617 case Op_AddP: {
618 Node* base = get_addp_base(n);
619 PointsToNode* ptn_base = ptnode_adr(base->_idx);
620 assert(ptn_base != NULL, "field's base should be registered");
621 add_base(n_ptn->as_Field(), ptn_base);
622 break;
623 }
624 case Op_CastPP:
625 case Op_CheckCastPP:
626 case Op_EncodeP:
627 case Op_DecodeN:
628 case Op_EncodePKlass:
629 case Op_DecodeNKlass: {
630 add_local_var_and_edge(n, PointsToNode::NoEscape,
631 n->in(1), NULL);
632 break;
633 }
634 case Op_CMoveP: {
635 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
636 Node* in = n->in(i);
637 if (in == NULL)
638 continue; // ignore NULL
639 Node* uncast_in = in->uncast();
640 if (uncast_in->is_top() || uncast_in == n)
641 continue; // ignore top or inputs which go back this node
642 PointsToNode* ptn = ptnode_adr(in->_idx);
643 assert(ptn != NULL, "node should be registered");
644 add_edge(n_ptn, ptn);
645 }
646 break;
647 }
648 case Op_LoadP:
649 case Op_LoadN:
650 case Op_LoadPLocked: {
651 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
652 // ThreadLocal has RawPtr type.
653 const Type* t = _igvn->type(n);
654 if (t->make_ptr() != NULL) {
655 Node* adr = n->in(MemNode::Address);
656 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
657 break;
658 }
659 ELSE_FAIL("Op_LoadP");
660 }
661 case Op_Phi: {
662 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
663 // ThreadLocal has RawPtr type.
664 const Type* t = n->as_Phi()->type();
665 if (t->make_ptr() != NULL) {
666 for (uint i = 1; i < n->req(); i++) {
667 Node* in = n->in(i);
668 if (in == NULL)
669 continue; // ignore NULL
670 Node* uncast_in = in->uncast();
671 if (uncast_in->is_top() || uncast_in == n)
672 continue; // ignore top or inputs which go back this node
673 PointsToNode* ptn = ptnode_adr(in->_idx);
674 assert(ptn != NULL, "node should be registered");
675 add_edge(n_ptn, ptn);
676 }
677 break;
678 }
679 ELSE_FAIL("Op_Phi");
680 }
681 case Op_Proj: {
682 // we are only interested in the oop result projection from a call
683 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
684 n->in(0)->as_Call()->returns_pointer()) {
685 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
686 break;
687 }
688 ELSE_FAIL("Op_Proj");
689 }
690 case Op_Rethrow: // Exception object escapes
691 case Op_Return: {
692 if (n->req() > TypeFunc::Parms &&
693 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
694 // Treat Return value as LocalVar with GlobalEscape escape state.
695 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
696 n->in(TypeFunc::Parms), NULL);
697 break;
698 }
699 ELSE_FAIL("Op_Return");
700 }
701 case Op_StoreP:
702 case Op_StoreN:
703 case Op_StoreNKlass:
704 case Op_StorePConditional:
705 case Op_CompareAndExchangeP:
706 case Op_CompareAndExchangeN:
707 case Op_CompareAndSwapP:
708 case Op_CompareAndSwapN:
709 case Op_WeakCompareAndSwapP:
710 case Op_WeakCompareAndSwapN:
711 case Op_GetAndSetP:
712 case Op_GetAndSetN: {
713 Node* adr = n->in(MemNode::Address);
714 const Type *adr_type = _igvn->type(adr);
715 adr_type = adr_type->make_ptr();
716 #ifdef ASSERT
717 if (adr_type == NULL) {
718 n->dump(1);
719 assert(adr_type != NULL, "dead node should not be on list");
720 break;
721 }
722 #endif
723 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
724 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
725 }
726 if (adr_type->isa_oopptr() ||
727 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
728 (adr_type == TypeRawPtr::NOTNULL &&
729 adr->in(AddPNode::Address)->is_Proj() &&
730 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
731 // Point Address to Value
732 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
733 assert(adr_ptn != NULL &&
734 adr_ptn->as_Field()->is_oop(), "node should be registered");
735 Node *val = n->in(MemNode::ValueIn);
736 PointsToNode* ptn = ptnode_adr(val->_idx);
737 assert(ptn != NULL, "node should be registered");
738 add_edge(adr_ptn, ptn);
739 break;
740 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
741 // Stored value escapes in unsafe access.
742 Node *val = n->in(MemNode::ValueIn);
743 PointsToNode* ptn = ptnode_adr(val->_idx);
744 assert(ptn != NULL, "node should be registered");
745 set_escape_state(ptn, PointsToNode::GlobalEscape);
746 // Add edge to object for unsafe access with offset.
747 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
748 assert(adr_ptn != NULL, "node should be registered");
749 if (adr_ptn->is_Field()) {
750 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
751 add_edge(adr_ptn, ptn);
752 }
753 break;
754 }
755 ELSE_FAIL("Op_StoreP");
756 }
757 case Op_AryEq:
758 case Op_HasNegatives:
759 case Op_StrComp:
760 case Op_StrEquals:
761 case Op_StrIndexOf:
762 case Op_StrIndexOfChar:
763 case Op_StrInflatedCopy:
764 case Op_StrCompressedCopy:
765 case Op_EncodeISOArray: {
766 // char[]/byte[] arrays passed to string intrinsic do not escape but
767 // they are not scalar replaceable. Adjust escape state for them.
768 // Start from in(2) edge since in(1) is memory edge.
769 for (uint i = 2; i < n->req(); i++) {
770 Node* adr = n->in(i);
771 const Type* at = _igvn->type(adr);
772 if (!adr->is_top() && at->isa_ptr()) {
773 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
774 at->isa_ptr() != NULL, "expecting a pointer");
775 if (adr->is_AddP()) {
776 adr = get_addp_base(adr);
777 }
778 PointsToNode* ptn = ptnode_adr(adr->_idx);
779 assert(ptn != NULL, "node should be registered");
780 add_edge(n_ptn, ptn);
781 }
782 }
783 break;
784 }
785 default: {
786 // This method should be called only for EA specific nodes which may
787 // miss some edges when they were created.
788 #ifdef ASSERT
789 n->dump(1);
790 #endif
791 guarantee(false, "unknown node");
792 }
793 }
794 return;
795 }
796
797 void ConnectionGraph::add_call_node(CallNode* call) {
798 assert(call->returns_pointer(), "only for call which returns pointer");
799 uint call_idx = call->_idx;
800 if (call->is_Allocate()) {
801 Node* k = call->in(AllocateNode::KlassNode);
802 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
803 assert(kt != NULL, "TypeKlassPtr required.");
804 ciKlass* cik = kt->klass();
805 PointsToNode::EscapeState es = PointsToNode::NoEscape;
806 bool scalar_replaceable = true;
807 if (call->is_AllocateArray()) {
808 if (!cik->is_array_klass()) { // StressReflectiveCode
809 es = PointsToNode::GlobalEscape;
810 } else {
811 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
812 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
813 // Not scalar replaceable if the length is not constant or too big.
814 scalar_replaceable = false;
815 }
816 }
817 } else { // Allocate instance
818 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
819 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
820 !cik->is_instance_klass() || // StressReflectiveCode
821 !cik->as_instance_klass()->can_be_instantiated() ||
822 cik->as_instance_klass()->has_finalizer()) {
823 es = PointsToNode::GlobalEscape;
824 }
825 }
826 add_java_object(call, es);
827 PointsToNode* ptn = ptnode_adr(call_idx);
828 if (!scalar_replaceable && ptn->scalar_replaceable()) {
829 ptn->set_scalar_replaceable(false);
830 }
831 } else if (call->is_CallStaticJava()) {
832 // Call nodes could be different types:
833 //
834 // 1. CallDynamicJavaNode (what happened during call is unknown):
835 //
836 // - mapped to GlobalEscape JavaObject node if oop is returned;
837 //
838 // - all oop arguments are escaping globally;
839 //
840 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
841 //
842 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
843 //
844 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
845 // - mapped to NoEscape JavaObject node if non-escaping object allocated
846 // during call is returned;
847 // - mapped to ArgEscape LocalVar node pointed to object arguments
848 // which are returned and does not escape during call;
849 //
850 // - oop arguments escaping status is defined by bytecode analysis;
851 //
852 // For a static call, we know exactly what method is being called.
853 // Use bytecode estimator to record whether the call's return value escapes.
854 ciMethod* meth = call->as_CallJava()->method();
855 if (meth == NULL) {
856 const char* name = call->as_CallStaticJava()->_name;
857 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
858 // Returns a newly allocated unescaped object.
859 add_java_object(call, PointsToNode::NoEscape);
860 ptnode_adr(call_idx)->set_scalar_replaceable(false);
861 } else if (meth->is_boxing_method()) {
862 // Returns boxing object
863 PointsToNode::EscapeState es;
864 vmIntrinsics::ID intr = meth->intrinsic_id();
865 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
866 // It does not escape if object is always allocated.
867 es = PointsToNode::NoEscape;
868 } else {
869 // It escapes globally if object could be loaded from cache.
870 es = PointsToNode::GlobalEscape;
871 }
872 add_java_object(call, es);
873 } else {
874 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
875 call_analyzer->copy_dependencies(_compile->dependencies());
876 if (call_analyzer->is_return_allocated()) {
877 // Returns a newly allocated unescaped object, simply
878 // update dependency information.
879 // Mark it as NoEscape so that objects referenced by
880 // it's fields will be marked as NoEscape at least.
881 add_java_object(call, PointsToNode::NoEscape);
882 ptnode_adr(call_idx)->set_scalar_replaceable(false);
883 } else {
884 // Determine whether any arguments are returned.
885 const TypeTuple* d = call->tf()->domain_sig();
886 bool ret_arg = false;
887 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
888 if (d->field_at(i)->isa_ptr() != NULL &&
889 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
890 ret_arg = true;
891 break;
892 }
893 }
894 if (ret_arg) {
895 add_local_var(call, PointsToNode::ArgEscape);
896 } else {
897 // Returns unknown object.
898 map_ideal_node(call, phantom_obj);
899 }
900 }
901 }
902 } else {
903 // An other type of call, assume the worst case:
904 // returned value is unknown and globally escapes.
905 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
906 map_ideal_node(call, phantom_obj);
907 }
908 }
909
910 void ConnectionGraph::process_call_arguments(CallNode *call) {
911 bool is_arraycopy = false;
912 switch (call->Opcode()) {
913 #ifdef ASSERT
914 case Op_Allocate:
915 case Op_AllocateArray:
916 case Op_Lock:
917 case Op_Unlock:
918 assert(false, "should be done already");
919 break;
920 #endif
921 case Op_ArrayCopy:
922 case Op_CallLeafNoFP:
923 // Most array copies are ArrayCopy nodes at this point but there
924 // are still a few direct calls to the copy subroutines (See
925 // PhaseStringOpts::copy_string())
926 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
927 call->as_CallLeaf()->is_call_to_arraycopystub();
928 // fall through
929 case Op_CallLeaf: {
930 // Stub calls, objects do not escape but they are not scale replaceable.
931 // Adjust escape state for outgoing arguments.
932 const TypeTuple * d = call->tf()->domain_sig();
933 bool src_has_oops = false;
934 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
935 const Type* at = d->field_at(i);
936 Node *arg = call->in(i);
937 if (arg == NULL) {
938 continue;
939 }
940 const Type *aat = _igvn->type(arg);
941 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
942 continue;
943 if (arg->is_AddP()) {
944 //
945 // The inline_native_clone() case when the arraycopy stub is called
946 // after the allocation before Initialize and CheckCastPP nodes.
947 // Or normal arraycopy for object arrays case.
948 //
949 // Set AddP's base (Allocate) as not scalar replaceable since
950 // pointer to the base (with offset) is passed as argument.
951 //
952 arg = get_addp_base(arg);
953 }
954 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
955 assert(arg_ptn != NULL, "should be registered");
956 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
957 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
958 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
959 aat->isa_ptr() != NULL, "expecting an Ptr");
960 bool arg_has_oops = aat->isa_oopptr() &&
961 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
962 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
963 if (i == TypeFunc::Parms) {
964 src_has_oops = arg_has_oops;
965 }
966 //
967 // src or dst could be j.l.Object when other is basic type array:
968 //
969 // arraycopy(char[],0,Object*,0,size);
970 // arraycopy(Object*,0,char[],0,size);
971 //
972 // Don't add edges in such cases.
973 //
974 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
975 arg_has_oops && (i > TypeFunc::Parms);
976 #ifdef ASSERT
977 if (!(is_arraycopy ||
978 (call->as_CallLeaf()->_name != NULL &&
979 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
980 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
981 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
982 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
983 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
984 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
985 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
986 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
993 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1002 ))) {
1003 call->dump();
1004 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1005 }
1006 #endif
1007 // Always process arraycopy's destination object since
1008 // we need to add all possible edges to references in
1009 // source object.
1010 if (arg_esc >= PointsToNode::ArgEscape &&
1011 !arg_is_arraycopy_dest) {
1012 continue;
1013 }
1014 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1015 if (call->is_ArrayCopy()) {
1016 ArrayCopyNode* ac = call->as_ArrayCopy();
1017 if (ac->is_clonebasic() ||
1018 ac->is_arraycopy_validated() ||
1019 ac->is_copyof_validated() ||
1020 ac->is_copyofrange_validated()) {
1021 es = PointsToNode::NoEscape;
1022 }
1023 }
1024 set_escape_state(arg_ptn, es);
1025 if (arg_is_arraycopy_dest) {
1026 Node* src = call->in(TypeFunc::Parms);
1027 if (src->is_AddP()) {
1028 src = get_addp_base(src);
1029 }
1030 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1031 assert(src_ptn != NULL, "should be registered");
1032 if (arg_ptn != src_ptn) {
1033 // Special arraycopy edge:
1034 // A destination object's field can't have the source object
1035 // as base since objects escape states are not related.
1036 // Only escape state of destination object's fields affects
1037 // escape state of fields in source object.
1038 add_arraycopy(call, es, src_ptn, arg_ptn);
1039 }
1040 }
1041 }
1042 }
1043 break;
1044 }
1045 case Op_CallStaticJava: {
1046 // For a static call, we know exactly what method is being called.
1047 // Use bytecode estimator to record the call's escape affects
1048 #ifdef ASSERT
1049 const char* name = call->as_CallStaticJava()->_name;
1050 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1051 #endif
1052 ciMethod* meth = call->as_CallJava()->method();
1053 if ((meth != NULL) && meth->is_boxing_method()) {
1054 break; // Boxing methods do not modify any oops.
1055 }
1056 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1057 // fall-through if not a Java method or no analyzer information
1058 if (call_analyzer != NULL) {
1059 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1060 const TypeTuple* d = call->tf()->domain_sig();
1061 int extra = 0;
1062 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1063 const Type* at = d->field_at(i);
1064 if (at->isa_valuetypeptr()) {
1065 extra += at->is_valuetypeptr()->value_type()->value_klass()->get_field_count() - 1;
1066 continue;
1067 }
1068 int k = i - TypeFunc::Parms;
1069 Node* arg = call->in(i + extra);
1070 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1071 if (at->isa_ptr() != NULL &&
1072 call_analyzer->is_arg_returned(k)) {
1073 // The call returns arguments.
1074 if (call_ptn != NULL) { // Is call's result used?
1075 assert(call_ptn->is_LocalVar(), "node should be registered");
1076 assert(arg_ptn != NULL, "node should be registered");
1077 add_edge(call_ptn, arg_ptn);
1078 }
1079 }
1080 if (at->isa_oopptr() != NULL &&
1081 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1082 if (!call_analyzer->is_arg_stack(k)) {
1083 // The argument global escapes
1084 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1085 } else {
1086 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1087 if (!call_analyzer->is_arg_local(k)) {
1088 // The argument itself doesn't escape, but any fields might
1089 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1090 }
1091 }
1092 }
1093 }
1094 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1095 // The call returns arguments.
1096 assert(call_ptn->edge_count() > 0, "sanity");
1097 if (!call_analyzer->is_return_local()) {
1098 // Returns also unknown object.
1099 add_edge(call_ptn, phantom_obj);
1100 }
1101 }
1102 break;
1103 }
1104 }
1105 default: {
1106 // Fall-through here if not a Java method or no analyzer information
1107 // or some other type of call, assume the worst case: all arguments
1108 // globally escape.
1109 const TypeTuple* d = call->tf()->domain_sig();
1110 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1111 const Type* at = d->field_at(i);
1112 if (at->isa_oopptr() != NULL) {
1113 Node* arg = call->in(i);
1114 if (arg->is_AddP()) {
1115 arg = get_addp_base(arg);
1116 }
1117 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1118 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1119 }
1120 }
1121 }
1122 }
1123 }
1124
1125
1126 // Finish Graph construction.
1127 bool ConnectionGraph::complete_connection_graph(
1128 GrowableArray<PointsToNode*>& ptnodes_worklist,
1129 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1130 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1131 GrowableArray<FieldNode*>& oop_fields_worklist) {
1132 // Normally only 1-3 passes needed to build Connection Graph depending
1133 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1134 // Set limit to 20 to catch situation when something did go wrong and
1135 // bailout Escape Analysis.
1136 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1137 #define CG_BUILD_ITER_LIMIT 20
1138
1139 // Propagate GlobalEscape and ArgEscape escape states and check that
1140 // we still have non-escaping objects. The method pushs on _worklist
1141 // Field nodes which reference phantom_object.
1142 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1143 return false; // Nothing to do.
1144 }
1145 // Now propagate references to all JavaObject nodes.
1146 int java_objects_length = java_objects_worklist.length();
1147 elapsedTimer time;
1148 bool timeout = false;
1149 int new_edges = 1;
1150 int iterations = 0;
1151 do {
1152 while ((new_edges > 0) &&
1153 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1154 double start_time = time.seconds();
1155 time.start();
1156 new_edges = 0;
1157 // Propagate references to phantom_object for nodes pushed on _worklist
1158 // by find_non_escaped_objects() and find_field_value().
1159 new_edges += add_java_object_edges(phantom_obj, false);
1160 for (int next = 0; next < java_objects_length; ++next) {
1161 JavaObjectNode* ptn = java_objects_worklist.at(next);
1162 new_edges += add_java_object_edges(ptn, true);
1163
1164 #define SAMPLE_SIZE 4
1165 if ((next % SAMPLE_SIZE) == 0) {
1166 // Each 4 iterations calculate how much time it will take
1167 // to complete graph construction.
1168 time.stop();
1169 // Poll for requests from shutdown mechanism to quiesce compiler
1170 // because Connection graph construction may take long time.
1171 CompileBroker::maybe_block();
1172 double stop_time = time.seconds();
1173 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1174 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1175 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1176 timeout = true;
1177 break; // Timeout
1178 }
1179 start_time = stop_time;
1180 time.start();
1181 }
1182 #undef SAMPLE_SIZE
1183
1184 }
1185 if (timeout) break;
1186 if (new_edges > 0) {
1187 // Update escape states on each iteration if graph was updated.
1188 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1189 return false; // Nothing to do.
1190 }
1191 }
1192 time.stop();
1193 if (time.seconds() >= EscapeAnalysisTimeout) {
1194 timeout = true;
1195 break;
1196 }
1197 }
1198 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1199 time.start();
1200 // Find fields which have unknown value.
1201 int fields_length = oop_fields_worklist.length();
1202 for (int next = 0; next < fields_length; next++) {
1203 FieldNode* field = oop_fields_worklist.at(next);
1204 if (field->edge_count() == 0) {
1205 new_edges += find_field_value(field);
1206 // This code may added new edges to phantom_object.
1207 // Need an other cycle to propagate references to phantom_object.
1208 }
1209 }
1210 time.stop();
1211 if (time.seconds() >= EscapeAnalysisTimeout) {
1212 timeout = true;
1213 break;
1214 }
1215 } else {
1216 new_edges = 0; // Bailout
1217 }
1218 } while (new_edges > 0);
1219
1220 // Bailout if passed limits.
1221 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1222 Compile* C = _compile;
1223 if (C->log() != NULL) {
1224 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1225 C->log()->text("%s", timeout ? "time" : "iterations");
1226 C->log()->end_elem(" limit'");
1227 }
1228 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1229 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1230 // Possible infinite build_connection_graph loop,
1231 // bailout (no changes to ideal graph were made).
1232 return false;
1233 }
1234 #ifdef ASSERT
1235 if (Verbose && PrintEscapeAnalysis) {
1236 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1237 iterations, nodes_size(), ptnodes_worklist.length());
1238 }
1239 #endif
1240
1241 #undef CG_BUILD_ITER_LIMIT
1242
1243 // Find fields initialized by NULL for non-escaping Allocations.
1244 int non_escaped_length = non_escaped_worklist.length();
1245 for (int next = 0; next < non_escaped_length; next++) {
1246 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1247 PointsToNode::EscapeState es = ptn->escape_state();
1248 assert(es <= PointsToNode::ArgEscape, "sanity");
1249 if (es == PointsToNode::NoEscape) {
1250 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1251 // Adding references to NULL object does not change escape states
1252 // since it does not escape. Also no fields are added to NULL object.
1253 add_java_object_edges(null_obj, false);
1254 }
1255 }
1256 Node* n = ptn->ideal_node();
1257 if (n->is_Allocate()) {
1258 // The object allocated by this Allocate node will never be
1259 // seen by an other thread. Mark it so that when it is
1260 // expanded no MemBarStoreStore is added.
1261 InitializeNode* ini = n->as_Allocate()->initialization();
1262 if (ini != NULL)
1263 ini->set_does_not_escape();
1264 }
1265 }
1266 return true; // Finished graph construction.
1267 }
1268
1269 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1270 // and check that we still have non-escaping java objects.
1271 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1272 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1273 GrowableArray<PointsToNode*> escape_worklist;
1274 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1275 int ptnodes_length = ptnodes_worklist.length();
1276 for (int next = 0; next < ptnodes_length; ++next) {
1277 PointsToNode* ptn = ptnodes_worklist.at(next);
1278 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1279 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1280 escape_worklist.push(ptn);
1281 }
1282 }
1283 // Set escape states to referenced nodes (edges list).
1284 while (escape_worklist.length() > 0) {
1285 PointsToNode* ptn = escape_worklist.pop();
1286 PointsToNode::EscapeState es = ptn->escape_state();
1287 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1288 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1289 es >= PointsToNode::ArgEscape) {
1290 // GlobalEscape or ArgEscape state of field means it has unknown value.
1291 if (add_edge(ptn, phantom_obj)) {
1292 // New edge was added
1293 add_field_uses_to_worklist(ptn->as_Field());
1294 }
1295 }
1296 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1297 PointsToNode* e = i.get();
1298 if (e->is_Arraycopy()) {
1299 assert(ptn->arraycopy_dst(), "sanity");
1300 // Propagate only fields escape state through arraycopy edge.
1301 if (e->fields_escape_state() < field_es) {
1302 set_fields_escape_state(e, field_es);
1303 escape_worklist.push(e);
1304 }
1305 } else if (es >= field_es) {
1306 // fields_escape_state is also set to 'es' if it is less than 'es'.
1307 if (e->escape_state() < es) {
1308 set_escape_state(e, es);
1309 escape_worklist.push(e);
1310 }
1311 } else {
1312 // Propagate field escape state.
1313 bool es_changed = false;
1314 if (e->fields_escape_state() < field_es) {
1315 set_fields_escape_state(e, field_es);
1316 es_changed = true;
1317 }
1318 if ((e->escape_state() < field_es) &&
1319 e->is_Field() && ptn->is_JavaObject() &&
1320 e->as_Field()->is_oop()) {
1321 // Change escape state of referenced fields.
1322 set_escape_state(e, field_es);
1323 es_changed = true;
1324 } else if (e->escape_state() < es) {
1325 set_escape_state(e, es);
1326 es_changed = true;
1327 }
1328 if (es_changed) {
1329 escape_worklist.push(e);
1330 }
1331 }
1332 }
1333 }
1334 // Remove escaped objects from non_escaped list.
1335 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1336 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1337 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1338 non_escaped_worklist.delete_at(next);
1339 }
1340 if (ptn->escape_state() == PointsToNode::NoEscape) {
1341 // Find fields in non-escaped allocations which have unknown value.
1342 find_init_values(ptn, phantom_obj, NULL);
1343 }
1344 }
1345 return (non_escaped_worklist.length() > 0);
1346 }
1347
1348 // Add all references to JavaObject node by walking over all uses.
1349 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1350 int new_edges = 0;
1351 if (populate_worklist) {
1352 // Populate _worklist by uses of jobj's uses.
1353 for (UseIterator i(jobj); i.has_next(); i.next()) {
1354 PointsToNode* use = i.get();
1355 if (use->is_Arraycopy())
1356 continue;
1357 add_uses_to_worklist(use);
1358 if (use->is_Field() && use->as_Field()->is_oop()) {
1359 // Put on worklist all field's uses (loads) and
1360 // related field nodes (same base and offset).
1361 add_field_uses_to_worklist(use->as_Field());
1362 }
1363 }
1364 }
1365 for (int l = 0; l < _worklist.length(); l++) {
1366 PointsToNode* use = _worklist.at(l);
1367 if (PointsToNode::is_base_use(use)) {
1368 // Add reference from jobj to field and from field to jobj (field's base).
1369 use = PointsToNode::get_use_node(use)->as_Field();
1370 if (add_base(use->as_Field(), jobj)) {
1371 new_edges++;
1372 }
1373 continue;
1374 }
1375 assert(!use->is_JavaObject(), "sanity");
1376 if (use->is_Arraycopy()) {
1377 if (jobj == null_obj) // NULL object does not have field edges
1378 continue;
1379 // Added edge from Arraycopy node to arraycopy's source java object
1380 if (add_edge(use, jobj)) {
1381 jobj->set_arraycopy_src();
1382 new_edges++;
1383 }
1384 // and stop here.
1385 continue;
1386 }
1387 if (!add_edge(use, jobj))
1388 continue; // No new edge added, there was such edge already.
1389 new_edges++;
1390 if (use->is_LocalVar()) {
1391 add_uses_to_worklist(use);
1392 if (use->arraycopy_dst()) {
1393 for (EdgeIterator i(use); i.has_next(); i.next()) {
1394 PointsToNode* e = i.get();
1395 if (e->is_Arraycopy()) {
1396 if (jobj == null_obj) // NULL object does not have field edges
1397 continue;
1398 // Add edge from arraycopy's destination java object to Arraycopy node.
1399 if (add_edge(jobj, e)) {
1400 new_edges++;
1401 jobj->set_arraycopy_dst();
1402 }
1403 }
1404 }
1405 }
1406 } else {
1407 // Added new edge to stored in field values.
1408 // Put on worklist all field's uses (loads) and
1409 // related field nodes (same base and offset).
1410 add_field_uses_to_worklist(use->as_Field());
1411 }
1412 }
1413 _worklist.clear();
1414 _in_worklist.Reset();
1415 return new_edges;
1416 }
1417
1418 // Put on worklist all related field nodes.
1419 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1420 assert(field->is_oop(), "sanity");
1421 int offset = field->offset();
1422 add_uses_to_worklist(field);
1423 // Loop over all bases of this field and push on worklist Field nodes
1424 // with the same offset and base (since they may reference the same field).
1425 for (BaseIterator i(field); i.has_next(); i.next()) {
1426 PointsToNode* base = i.get();
1427 add_fields_to_worklist(field, base);
1428 // Check if the base was source object of arraycopy and go over arraycopy's
1429 // destination objects since values stored to a field of source object are
1430 // accessable by uses (loads) of fields of destination objects.
1431 if (base->arraycopy_src()) {
1432 for (UseIterator j(base); j.has_next(); j.next()) {
1433 PointsToNode* arycp = j.get();
1434 if (arycp->is_Arraycopy()) {
1435 for (UseIterator k(arycp); k.has_next(); k.next()) {
1436 PointsToNode* abase = k.get();
1437 if (abase->arraycopy_dst() && abase != base) {
1438 // Look for the same arraycopy reference.
1439 add_fields_to_worklist(field, abase);
1440 }
1441 }
1442 }
1443 }
1444 }
1445 }
1446 }
1447
1448 // Put on worklist all related field nodes.
1449 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1450 int offset = field->offset();
1451 if (base->is_LocalVar()) {
1452 for (UseIterator j(base); j.has_next(); j.next()) {
1453 PointsToNode* f = j.get();
1454 if (PointsToNode::is_base_use(f)) { // Field
1455 f = PointsToNode::get_use_node(f);
1456 if (f == field || !f->as_Field()->is_oop())
1457 continue;
1458 int offs = f->as_Field()->offset();
1459 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1460 add_to_worklist(f);
1461 }
1462 }
1463 }
1464 } else {
1465 assert(base->is_JavaObject(), "sanity");
1466 if (// Skip phantom_object since it is only used to indicate that
1467 // this field's content globally escapes.
1468 (base != phantom_obj) &&
1469 // NULL object node does not have fields.
1470 (base != null_obj)) {
1471 for (EdgeIterator i(base); i.has_next(); i.next()) {
1472 PointsToNode* f = i.get();
1473 // Skip arraycopy edge since store to destination object field
1474 // does not update value in source object field.
1475 if (f->is_Arraycopy()) {
1476 assert(base->arraycopy_dst(), "sanity");
1477 continue;
1478 }
1479 if (f == field || !f->as_Field()->is_oop())
1480 continue;
1481 int offs = f->as_Field()->offset();
1482 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1483 add_to_worklist(f);
1484 }
1485 }
1486 }
1487 }
1488 }
1489
1490 // Find fields which have unknown value.
1491 int ConnectionGraph::find_field_value(FieldNode* field) {
1492 // Escaped fields should have init value already.
1493 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1494 int new_edges = 0;
1495 for (BaseIterator i(field); i.has_next(); i.next()) {
1496 PointsToNode* base = i.get();
1497 if (base->is_JavaObject()) {
1498 // Skip Allocate's fields which will be processed later.
1499 if (base->ideal_node()->is_Allocate())
1500 return 0;
1501 assert(base == null_obj, "only NULL ptr base expected here");
1502 }
1503 }
1504 if (add_edge(field, phantom_obj)) {
1505 // New edge was added
1506 new_edges++;
1507 add_field_uses_to_worklist(field);
1508 }
1509 return new_edges;
1510 }
1511
1512 // Find fields initializing values for allocations.
1513 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1514 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1515 int new_edges = 0;
1516 Node* alloc = pta->ideal_node();
1517 if (init_val == phantom_obj) {
1518 // Do nothing for Allocate nodes since its fields values are
1519 // "known" unless they are initialized by arraycopy/clone.
1520 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1521 return 0;
1522 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1523 #ifdef ASSERT
1524 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1525 const char* name = alloc->as_CallStaticJava()->_name;
1526 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1527 }
1528 #endif
1529 // Non-escaped allocation returned from Java or runtime call have
1530 // unknown values in fields.
1531 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1532 PointsToNode* field = i.get();
1533 if (field->is_Field() && field->as_Field()->is_oop()) {
1534 if (add_edge(field, phantom_obj)) {
1535 // New edge was added
1536 new_edges++;
1537 add_field_uses_to_worklist(field->as_Field());
1538 }
1539 }
1540 }
1541 return new_edges;
1542 }
1543 assert(init_val == null_obj, "sanity");
1544 // Do nothing for Call nodes since its fields values are unknown.
1545 if (!alloc->is_Allocate())
1546 return 0;
1547
1548 InitializeNode* ini = alloc->as_Allocate()->initialization();
1549 bool visited_bottom_offset = false;
1550 GrowableArray<int> offsets_worklist;
1551
1552 // Check if an oop field's initializing value is recorded and add
1553 // a corresponding NULL if field's value if it is not recorded.
1554 // Connection Graph does not record a default initialization by NULL
1555 // captured by Initialize node.
1556 //
1557 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1558 PointsToNode* field = i.get(); // Field (AddP)
1559 if (!field->is_Field() || !field->as_Field()->is_oop())
1560 continue; // Not oop field
1561 int offset = field->as_Field()->offset();
1562 if (offset == Type::OffsetBot) {
1563 if (!visited_bottom_offset) {
1564 // OffsetBot is used to reference array's element,
1565 // always add reference to NULL to all Field nodes since we don't
1566 // known which element is referenced.
1567 if (add_edge(field, null_obj)) {
1568 // New edge was added
1569 new_edges++;
1570 add_field_uses_to_worklist(field->as_Field());
1571 visited_bottom_offset = true;
1572 }
1573 }
1574 } else {
1575 // Check only oop fields.
1576 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1577 if (adr_type->isa_rawptr()) {
1578 #ifdef ASSERT
1579 // Raw pointers are used for initializing stores so skip it
1580 // since it should be recorded already
1581 Node* base = get_addp_base(field->ideal_node());
1582 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1583 (base->in(0) == alloc),"unexpected pointer type");
1584 #endif
1585 continue;
1586 }
1587 if (!offsets_worklist.contains(offset)) {
1588 offsets_worklist.append(offset);
1589 Node* value = NULL;
1590 if (ini != NULL) {
1591 // StoreP::memory_type() == T_ADDRESS
1592 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1593 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1594 // Make sure initializing store has the same type as this AddP.
1595 // This AddP may reference non existing field because it is on a
1596 // dead branch of bimorphic call which is not eliminated yet.
1597 if (store != NULL && store->is_Store() &&
1598 store->as_Store()->memory_type() == ft) {
1599 value = store->in(MemNode::ValueIn);
1600 #ifdef ASSERT
1601 if (VerifyConnectionGraph) {
1602 // Verify that AddP already points to all objects the value points to.
1603 PointsToNode* val = ptnode_adr(value->_idx);
1604 assert((val != NULL), "should be processed already");
1605 PointsToNode* missed_obj = NULL;
1606 if (val->is_JavaObject()) {
1607 if (!field->points_to(val->as_JavaObject())) {
1608 missed_obj = val;
1609 }
1610 } else {
1611 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1612 tty->print_cr("----------init store has invalid value -----");
1613 store->dump();
1614 val->dump();
1615 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1616 }
1617 for (EdgeIterator j(val); j.has_next(); j.next()) {
1618 PointsToNode* obj = j.get();
1619 if (obj->is_JavaObject()) {
1620 if (!field->points_to(obj->as_JavaObject())) {
1621 missed_obj = obj;
1622 break;
1623 }
1624 }
1625 }
1626 }
1627 if (missed_obj != NULL) {
1628 tty->print_cr("----------field---------------------------------");
1629 field->dump();
1630 tty->print_cr("----------missed referernce to object-----------");
1631 missed_obj->dump();
1632 tty->print_cr("----------object referernced by init store -----");
1633 store->dump();
1634 val->dump();
1635 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1636 }
1637 }
1638 #endif
1639 } else {
1640 // There could be initializing stores which follow allocation.
1641 // For example, a volatile field store is not collected
1642 // by Initialize node.
1643 //
1644 // Need to check for dependent loads to separate such stores from
1645 // stores which follow loads. For now, add initial value NULL so
1646 // that compare pointers optimization works correctly.
1647 }
1648 }
1649 if (value == NULL) {
1650 // A field's initializing value was not recorded. Add NULL.
1651 if (add_edge(field, null_obj)) {
1652 // New edge was added
1653 new_edges++;
1654 add_field_uses_to_worklist(field->as_Field());
1655 }
1656 }
1657 }
1658 }
1659 }
1660 return new_edges;
1661 }
1662
1663 // Adjust scalar_replaceable state after Connection Graph is built.
1664 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1665 // Search for non-escaping objects which are not scalar replaceable
1666 // and mark them to propagate the state to referenced objects.
1667
1668 // 1. An object is not scalar replaceable if the field into which it is
1669 // stored has unknown offset (stored into unknown element of an array).
1670 //
1671 for (UseIterator i(jobj); i.has_next(); i.next()) {
1672 PointsToNode* use = i.get();
1673 if (use->is_Arraycopy()) {
1674 continue;
1675 }
1676 if (use->is_Field()) {
1677 FieldNode* field = use->as_Field();
1678 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1679 if (field->offset() == Type::OffsetBot) {
1680 jobj->set_scalar_replaceable(false);
1681 return;
1682 }
1683 // 2. An object is not scalar replaceable if the field into which it is
1684 // stored has multiple bases one of which is null.
1685 if (field->base_count() > 1) {
1686 for (BaseIterator i(field); i.has_next(); i.next()) {
1687 PointsToNode* base = i.get();
1688 if (base == null_obj) {
1689 jobj->set_scalar_replaceable(false);
1690 return;
1691 }
1692 }
1693 }
1694 }
1695 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1696 // 3. An object is not scalar replaceable if it is merged with other objects.
1697 for (EdgeIterator j(use); j.has_next(); j.next()) {
1698 PointsToNode* ptn = j.get();
1699 if (ptn->is_JavaObject() && ptn != jobj) {
1700 // Mark all objects.
1701 jobj->set_scalar_replaceable(false);
1702 ptn->set_scalar_replaceable(false);
1703 }
1704 }
1705 if (!jobj->scalar_replaceable()) {
1706 return;
1707 }
1708 }
1709
1710 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1711 if (j.get()->is_Arraycopy()) {
1712 continue;
1713 }
1714
1715 // Non-escaping object node should point only to field nodes.
1716 FieldNode* field = j.get()->as_Field();
1717 int offset = field->as_Field()->offset();
1718
1719 // 4. An object is not scalar replaceable if it has a field with unknown
1720 // offset (array's element is accessed in loop).
1721 if (offset == Type::OffsetBot) {
1722 jobj->set_scalar_replaceable(false);
1723 return;
1724 }
1725 // 5. Currently an object is not scalar replaceable if a LoadStore node
1726 // access its field since the field value is unknown after it.
1727 //
1728 Node* n = field->ideal_node();
1729 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1730 if (n->fast_out(i)->is_LoadStore()) {
1731 jobj->set_scalar_replaceable(false);
1732 return;
1733 }
1734 }
1735
1736 // 6. Or the address may point to more then one object. This may produce
1737 // the false positive result (set not scalar replaceable)
1738 // since the flow-insensitive escape analysis can't separate
1739 // the case when stores overwrite the field's value from the case
1740 // when stores happened on different control branches.
1741 //
1742 // Note: it will disable scalar replacement in some cases:
1743 //
1744 // Point p[] = new Point[1];
1745 // p[0] = new Point(); // Will be not scalar replaced
1746 //
1747 // but it will save us from incorrect optimizations in next cases:
1748 //
1749 // Point p[] = new Point[1];
1750 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1751 //
1752 if (field->base_count() > 1) {
1753 for (BaseIterator i(field); i.has_next(); i.next()) {
1754 PointsToNode* base = i.get();
1755 // Don't take into account LocalVar nodes which
1756 // may point to only one object which should be also
1757 // this field's base by now.
1758 if (base->is_JavaObject() && base != jobj) {
1759 // Mark all bases.
1760 jobj->set_scalar_replaceable(false);
1761 base->set_scalar_replaceable(false);
1762 }
1763 }
1764 }
1765 }
1766 }
1767
1768 #ifdef ASSERT
1769 void ConnectionGraph::verify_connection_graph(
1770 GrowableArray<PointsToNode*>& ptnodes_worklist,
1771 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1772 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1773 GrowableArray<Node*>& addp_worklist) {
1774 // Verify that graph is complete - no new edges could be added.
1775 int java_objects_length = java_objects_worklist.length();
1776 int non_escaped_length = non_escaped_worklist.length();
1777 int new_edges = 0;
1778 for (int next = 0; next < java_objects_length; ++next) {
1779 JavaObjectNode* ptn = java_objects_worklist.at(next);
1780 new_edges += add_java_object_edges(ptn, true);
1781 }
1782 assert(new_edges == 0, "graph was not complete");
1783 // Verify that escape state is final.
1784 int length = non_escaped_worklist.length();
1785 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1786 assert((non_escaped_length == non_escaped_worklist.length()) &&
1787 (non_escaped_length == length) &&
1788 (_worklist.length() == 0), "escape state was not final");
1789
1790 // Verify fields information.
1791 int addp_length = addp_worklist.length();
1792 for (int next = 0; next < addp_length; ++next ) {
1793 Node* n = addp_worklist.at(next);
1794 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1795 if (field->is_oop()) {
1796 // Verify that field has all bases
1797 Node* base = get_addp_base(n);
1798 PointsToNode* ptn = ptnode_adr(base->_idx);
1799 if (ptn->is_JavaObject()) {
1800 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1801 } else {
1802 assert(ptn->is_LocalVar(), "sanity");
1803 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1804 PointsToNode* e = i.get();
1805 if (e->is_JavaObject()) {
1806 assert(field->has_base(e->as_JavaObject()), "sanity");
1807 }
1808 }
1809 }
1810 // Verify that all fields have initializing values.
1811 if (field->edge_count() == 0) {
1812 tty->print_cr("----------field does not have references----------");
1813 field->dump();
1814 for (BaseIterator i(field); i.has_next(); i.next()) {
1815 PointsToNode* base = i.get();
1816 tty->print_cr("----------field has next base---------------------");
1817 base->dump();
1818 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1819 tty->print_cr("----------base has fields-------------------------");
1820 for (EdgeIterator j(base); j.has_next(); j.next()) {
1821 j.get()->dump();
1822 }
1823 tty->print_cr("----------base has references---------------------");
1824 for (UseIterator j(base); j.has_next(); j.next()) {
1825 j.get()->dump();
1826 }
1827 }
1828 }
1829 for (UseIterator i(field); i.has_next(); i.next()) {
1830 i.get()->dump();
1831 }
1832 assert(field->edge_count() > 0, "sanity");
1833 }
1834 }
1835 }
1836 }
1837 #endif
1838
1839 // Optimize ideal graph.
1840 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1841 GrowableArray<Node*>& storestore_worklist) {
1842 Compile* C = _compile;
1843 PhaseIterGVN* igvn = _igvn;
1844 if (EliminateLocks) {
1845 // Mark locks before changing ideal graph.
1846 int cnt = C->macro_count();
1847 for( int i=0; i < cnt; i++ ) {
1848 Node *n = C->macro_node(i);
1849 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1850 AbstractLockNode* alock = n->as_AbstractLock();
1851 if (!alock->is_non_esc_obj()) {
1852 if (not_global_escape(alock->obj_node())) {
1853 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1854 // The lock could be marked eliminated by lock coarsening
1855 // code during first IGVN before EA. Replace coarsened flag
1856 // to eliminate all associated locks/unlocks.
1857 #ifdef ASSERT
1858 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1859 #endif
1860 alock->set_non_esc_obj();
1861 }
1862 }
1863 }
1864 }
1865 }
1866
1867 if (OptimizePtrCompare) {
1868 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1869 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1870 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1871 // Optimize objects compare.
1872 while (ptr_cmp_worklist.length() != 0) {
1873 Node *n = ptr_cmp_worklist.pop();
1874 Node *res = optimize_ptr_compare(n);
1875 if (res != NULL) {
1876 #ifndef PRODUCT
1877 if (PrintOptimizePtrCompare) {
1878 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"));
1879 if (Verbose) {
1880 n->dump(1);
1881 }
1882 }
1883 #endif
1884 igvn->replace_node(n, res);
1885 }
1886 }
1887 // cleanup
1888 if (_pcmp_neq->outcnt() == 0)
1889 igvn->hash_delete(_pcmp_neq);
1890 if (_pcmp_eq->outcnt() == 0)
1891 igvn->hash_delete(_pcmp_eq);
1892 }
1893
1894 // For MemBarStoreStore nodes added in library_call.cpp, check
1895 // escape status of associated AllocateNode and optimize out
1896 // MemBarStoreStore node if the allocated object never escapes.
1897 while (storestore_worklist.length() != 0) {
1898 Node *n = storestore_worklist.pop();
1899 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1900 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1901 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1902 if (not_global_escape(alloc)) {
1903 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1904 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1905 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1906 igvn->register_new_node_with_optimizer(mb);
1907 igvn->replace_node(storestore, mb);
1908 }
1909 }
1910 }
1911
1912 // Optimize objects compare.
1913 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1914 assert(OptimizePtrCompare, "sanity");
1915 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1916 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1917 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1918 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1919 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1920 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1921
1922 // Check simple cases first.
1923 if (jobj1 != NULL) {
1924 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1925 if (jobj1 == jobj2) {
1926 // Comparing the same not escaping object.
1927 return _pcmp_eq;
1928 }
1929 Node* obj = jobj1->ideal_node();
1930 // Comparing not escaping allocation.
1931 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1932 !ptn2->points_to(jobj1)) {
1933 return _pcmp_neq; // This includes nullness check.
1934 }
1935 }
1936 }
1937 if (jobj2 != NULL) {
1938 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1939 Node* obj = jobj2->ideal_node();
1940 // Comparing not escaping allocation.
1941 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1942 !ptn1->points_to(jobj2)) {
1943 return _pcmp_neq; // This includes nullness check.
1944 }
1945 }
1946 }
1947 if (jobj1 != NULL && jobj1 != phantom_obj &&
1948 jobj2 != NULL && jobj2 != phantom_obj &&
1949 jobj1->ideal_node()->is_Con() &&
1950 jobj2->ideal_node()->is_Con()) {
1951 // Klass or String constants compare. Need to be careful with
1952 // compressed pointers - compare types of ConN and ConP instead of nodes.
1953 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1954 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1955 if (t1->make_ptr() == t2->make_ptr()) {
1956 return _pcmp_eq;
1957 } else {
1958 return _pcmp_neq;
1959 }
1960 }
1961 if (ptn1->meet(ptn2)) {
1962 return NULL; // Sets are not disjoint
1963 }
1964
1965 // Sets are disjoint.
1966 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1967 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1968 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1969 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1970 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1971 set2_has_unknown_ptr && set1_has_null_ptr) {
1972 // Check nullness of unknown object.
1973 return NULL;
1974 }
1975
1976 // Disjointness by itself is not sufficient since
1977 // alias analysis is not complete for escaped objects.
1978 // Disjoint sets are definitely unrelated only when
1979 // at least one set has only not escaping allocations.
1980 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1981 if (ptn1->non_escaping_allocation()) {
1982 return _pcmp_neq;
1983 }
1984 }
1985 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1986 if (ptn2->non_escaping_allocation()) {
1987 return _pcmp_neq;
1988 }
1989 }
1990 return NULL;
1991 }
1992
1993 // Connection Graph constuction functions.
1994
1995 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1996 PointsToNode* ptadr = _nodes.at(n->_idx);
1997 if (ptadr != NULL) {
1998 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1999 return;
2000 }
2001 Compile* C = _compile;
2002 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2003 _nodes.at_put(n->_idx, ptadr);
2004 }
2005
2006 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2007 PointsToNode* ptadr = _nodes.at(n->_idx);
2008 if (ptadr != NULL) {
2009 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2010 return;
2011 }
2012 Compile* C = _compile;
2013 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2014 _nodes.at_put(n->_idx, ptadr);
2015 }
2016
2017 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2018 PointsToNode* ptadr = _nodes.at(n->_idx);
2019 if (ptadr != NULL) {
2020 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2021 return;
2022 }
2023 bool unsafe = false;
2024 bool is_oop = is_oop_field(n, offset, &unsafe);
2025 if (unsafe) {
2026 es = PointsToNode::GlobalEscape;
2027 }
2028 Compile* C = _compile;
2029 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2030 _nodes.at_put(n->_idx, field);
2031 }
2032
2033 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2034 PointsToNode* src, PointsToNode* dst) {
2035 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2036 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2037 PointsToNode* ptadr = _nodes.at(n->_idx);
2038 if (ptadr != NULL) {
2039 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2040 return;
2041 }
2042 Compile* C = _compile;
2043 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2044 _nodes.at_put(n->_idx, ptadr);
2045 // Add edge from arraycopy node to source object.
2046 (void)add_edge(ptadr, src);
2047 src->set_arraycopy_src();
2048 // Add edge from destination object to arraycopy node.
2049 (void)add_edge(dst, ptadr);
2050 dst->set_arraycopy_dst();
2051 }
2052
2053 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2054 const Type* adr_type = n->as_AddP()->bottom_type();
2055 BasicType bt = T_INT;
2056 if (offset == Type::OffsetBot) {
2057 // Check only oop fields.
2058 if (!adr_type->isa_aryptr() ||
2059 (adr_type->isa_aryptr()->klass() == NULL) ||
2060 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2061 // OffsetBot is used to reference array's element. Ignore first AddP.
2062 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2063 bt = T_OBJECT;
2064 }
2065 }
2066 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2067 if (adr_type->isa_instptr()) {
2068 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2069 if (field != NULL) {
2070 bt = field->layout_type();
2071 } else {
2072 // Check for unsafe oop field access
2073 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2074 bt = T_OBJECT;
2075 (*unsafe) = true;
2076 }
2077 }
2078 } else if (adr_type->isa_aryptr()) {
2079 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2080 // Ignore array length load.
2081 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2082 // Ignore first AddP.
2083 } else {
2084 const Type* elemtype = adr_type->isa_aryptr()->elem();
2085 bt = elemtype->array_element_basic_type();
2086 }
2087 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2088 // Allocation initialization, ThreadLocal field access, unsafe access
2089 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2090 bt = T_OBJECT;
2091 }
2092 }
2093 }
2094 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2095 }
2096
2097 // Returns unique pointed java object or NULL.
2098 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2099 assert(!_collecting, "should not call when contructed graph");
2100 // If the node was created after the escape computation we can't answer.
2101 uint idx = n->_idx;
2102 if (idx >= nodes_size()) {
2103 return NULL;
2104 }
2105 PointsToNode* ptn = ptnode_adr(idx);
2106 if (ptn->is_JavaObject()) {
2107 return ptn->as_JavaObject();
2108 }
2109 assert(ptn->is_LocalVar(), "sanity");
2110 // Check all java objects it points to.
2111 JavaObjectNode* jobj = NULL;
2112 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2113 PointsToNode* e = i.get();
2114 if (e->is_JavaObject()) {
2115 if (jobj == NULL) {
2116 jobj = e->as_JavaObject();
2117 } else if (jobj != e) {
2118 return NULL;
2119 }
2120 }
2121 }
2122 return jobj;
2123 }
2124
2125 // Return true if this node points only to non-escaping allocations.
2126 bool PointsToNode::non_escaping_allocation() {
2127 if (is_JavaObject()) {
2128 Node* n = ideal_node();
2129 if (n->is_Allocate() || n->is_CallStaticJava()) {
2130 return (escape_state() == PointsToNode::NoEscape);
2131 } else {
2132 return false;
2133 }
2134 }
2135 assert(is_LocalVar(), "sanity");
2136 // Check all java objects it points to.
2137 for (EdgeIterator i(this); i.has_next(); i.next()) {
2138 PointsToNode* e = i.get();
2139 if (e->is_JavaObject()) {
2140 Node* n = e->ideal_node();
2141 if ((e->escape_state() != PointsToNode::NoEscape) ||
2142 !(n->is_Allocate() || n->is_CallStaticJava())) {
2143 return false;
2144 }
2145 }
2146 }
2147 return true;
2148 }
2149
2150 // Return true if we know the node does not escape globally.
2151 bool ConnectionGraph::not_global_escape(Node *n) {
2152 assert(!_collecting, "should not call during graph construction");
2153 // If the node was created after the escape computation we can't answer.
2154 uint idx = n->_idx;
2155 if (idx >= nodes_size()) {
2156 return false;
2157 }
2158 PointsToNode* ptn = ptnode_adr(idx);
2159 PointsToNode::EscapeState es = ptn->escape_state();
2160 // If we have already computed a value, return it.
2161 if (es >= PointsToNode::GlobalEscape)
2162 return false;
2163 if (ptn->is_JavaObject()) {
2164 return true; // (es < PointsToNode::GlobalEscape);
2165 }
2166 assert(ptn->is_LocalVar(), "sanity");
2167 // Check all java objects it points to.
2168 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2169 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2170 return false;
2171 }
2172 return true;
2173 }
2174
2175
2176 // Helper functions
2177
2178 // Return true if this node points to specified node or nodes it points to.
2179 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2180 if (is_JavaObject()) {
2181 return (this == ptn);
2182 }
2183 assert(is_LocalVar() || is_Field(), "sanity");
2184 for (EdgeIterator i(this); i.has_next(); i.next()) {
2185 if (i.get() == ptn)
2186 return true;
2187 }
2188 return false;
2189 }
2190
2191 // Return true if one node points to an other.
2192 bool PointsToNode::meet(PointsToNode* ptn) {
2193 if (this == ptn) {
2194 return true;
2195 } else if (ptn->is_JavaObject()) {
2196 return this->points_to(ptn->as_JavaObject());
2197 } else if (this->is_JavaObject()) {
2198 return ptn->points_to(this->as_JavaObject());
2199 }
2200 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2201 int ptn_count = ptn->edge_count();
2202 for (EdgeIterator i(this); i.has_next(); i.next()) {
2203 PointsToNode* this_e = i.get();
2204 for (int j = 0; j < ptn_count; j++) {
2205 if (this_e == ptn->edge(j))
2206 return true;
2207 }
2208 }
2209 return false;
2210 }
2211
2212 #ifdef ASSERT
2213 // Return true if bases point to this java object.
2214 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2215 for (BaseIterator i(this); i.has_next(); i.next()) {
2216 if (i.get() == jobj)
2217 return true;
2218 }
2219 return false;
2220 }
2221 #endif
2222
2223 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2224 const Type *adr_type = phase->type(adr);
2225 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2226 adr->in(AddPNode::Address)->is_Proj() &&
2227 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2228 // We are computing a raw address for a store captured by an Initialize
2229 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2230 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2231 assert(offs != Type::OffsetBot ||
2232 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2233 "offset must be a constant or it is initialization of array");
2234 return offs;
2235 }
2236 const TypePtr *t_ptr = adr_type->isa_ptr();
2237 assert(t_ptr != NULL, "must be a pointer type");
2238 return t_ptr->offset();
2239 }
2240
2241 Node* ConnectionGraph::get_addp_base(Node *addp) {
2242 assert(addp->is_AddP(), "must be AddP");
2243 //
2244 // AddP cases for Base and Address inputs:
2245 // case #1. Direct object's field reference:
2246 // Allocate
2247 // |
2248 // Proj #5 ( oop result )
2249 // |
2250 // CheckCastPP (cast to instance type)
2251 // | |
2252 // AddP ( base == address )
2253 //
2254 // case #2. Indirect object's field reference:
2255 // Phi
2256 // |
2257 // CastPP (cast to instance type)
2258 // | |
2259 // AddP ( base == address )
2260 //
2261 // case #3. Raw object's field reference for Initialize node:
2262 // Allocate
2263 // |
2264 // Proj #5 ( oop result )
2265 // top |
2266 // \ |
2267 // AddP ( base == top )
2268 //
2269 // case #4. Array's element reference:
2270 // {CheckCastPP | CastPP}
2271 // | | |
2272 // | AddP ( array's element offset )
2273 // | |
2274 // AddP ( array's offset )
2275 //
2276 // case #5. Raw object's field reference for arraycopy stub call:
2277 // The inline_native_clone() case when the arraycopy stub is called
2278 // after the allocation before Initialize and CheckCastPP nodes.
2279 // Allocate
2280 // |
2281 // Proj #5 ( oop result )
2282 // | |
2283 // AddP ( base == address )
2284 //
2285 // case #6. Constant Pool, ThreadLocal, CastX2P or
2286 // Raw object's field reference:
2287 // {ConP, ThreadLocal, CastX2P, raw Load}
2288 // top |
2289 // \ |
2290 // AddP ( base == top )
2291 //
2292 // case #7. Klass's field reference.
2293 // LoadKlass
2294 // | |
2295 // AddP ( base == address )
2296 //
2297 // case #8. narrow Klass's field reference.
2298 // LoadNKlass
2299 // |
2300 // DecodeN
2301 // | |
2302 // AddP ( base == address )
2303 //
2304 Node *base = addp->in(AddPNode::Base);
2305 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2306 base = addp->in(AddPNode::Address);
2307 while (base->is_AddP()) {
2308 // Case #6 (unsafe access) may have several chained AddP nodes.
2309 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2310 base = base->in(AddPNode::Address);
2311 }
2312 Node* uncast_base = base->uncast();
2313 int opcode = uncast_base->Opcode();
2314 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2315 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2316 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2317 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2318 }
2319 return base;
2320 }
2321
2322 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2323 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2324 Node* addp2 = addp->raw_out(0);
2325 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2326 addp2->in(AddPNode::Base) == n &&
2327 addp2->in(AddPNode::Address) == addp) {
2328 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2329 //
2330 // Find array's offset to push it on worklist first and
2331 // as result process an array's element offset first (pushed second)
2332 // to avoid CastPP for the array's offset.
2333 // Otherwise the inserted CastPP (LocalVar) will point to what
2334 // the AddP (Field) points to. Which would be wrong since
2335 // the algorithm expects the CastPP has the same point as
2336 // as AddP's base CheckCastPP (LocalVar).
2337 //
2338 // ArrayAllocation
2339 // |
2340 // CheckCastPP
2341 // |
2342 // memProj (from ArrayAllocation CheckCastPP)
2343 // | ||
2344 // | || Int (element index)
2345 // | || | ConI (log(element size))
2346 // | || | /
2347 // | || LShift
2348 // | || /
2349 // | AddP (array's element offset)
2350 // | |
2351 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2352 // | / /
2353 // AddP (array's offset)
2354 // |
2355 // Load/Store (memory operation on array's element)
2356 //
2357 return addp2;
2358 }
2359 return NULL;
2360 }
2361
2362 //
2363 // Adjust the type and inputs of an AddP which computes the
2364 // address of a field of an instance
2365 //
2366 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2367 PhaseGVN* igvn = _igvn;
2368 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2369 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2370 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2371 if (t == NULL) {
2372 // We are computing a raw address for a store captured by an Initialize
2373 // compute an appropriate address type (cases #3 and #5).
2374 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2375 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2376 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2377 assert(offs != Type::OffsetBot, "offset must be a constant");
2378 t = base_t->add_offset(offs)->is_oopptr();
2379 }
2380 int inst_id = base_t->instance_id();
2381 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2382 "old type must be non-instance or match new type");
2383
2384 // The type 't' could be subclass of 'base_t'.
2385 // As result t->offset() could be large then base_t's size and it will
2386 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2387 // constructor verifies correctness of the offset.
2388 //
2389 // It could happened on subclass's branch (from the type profiling
2390 // inlining) which was not eliminated during parsing since the exactness
2391 // of the allocation type was not propagated to the subclass type check.
2392 //
2393 // Or the type 't' could be not related to 'base_t' at all.
2394 // It could happened when CHA type is different from MDO type on a dead path
2395 // (for example, from instanceof check) which is not collapsed during parsing.
2396 //
2397 // Do nothing for such AddP node and don't process its users since
2398 // this code branch will go away.
2399 //
2400 if (!t->is_known_instance() &&
2401 !base_t->klass()->is_subtype_of(t->klass())) {
2402 return false; // bail out
2403 }
2404 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2405 // Do NOT remove the next line: ensure a new alias index is allocated
2406 // for the instance type. Note: C++ will not remove it since the call
2407 // has side effect.
2408 int alias_idx = _compile->get_alias_index(tinst);
2409 igvn->set_type(addp, tinst);
2410 // record the allocation in the node map
2411 set_map(addp, get_map(base->_idx));
2412 // Set addp's Base and Address to 'base'.
2413 Node *abase = addp->in(AddPNode::Base);
2414 Node *adr = addp->in(AddPNode::Address);
2415 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2416 adr->in(0)->_idx == (uint)inst_id) {
2417 // Skip AddP cases #3 and #5.
2418 } else {
2419 assert(!abase->is_top(), "sanity"); // AddP case #3
2420 if (abase != base) {
2421 igvn->hash_delete(addp);
2422 addp->set_req(AddPNode::Base, base);
2423 if (abase == adr) {
2424 addp->set_req(AddPNode::Address, base);
2425 } else {
2426 // AddP case #4 (adr is array's element offset AddP node)
2427 #ifdef ASSERT
2428 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2429 assert(adr->is_AddP() && atype != NULL &&
2430 atype->instance_id() == inst_id, "array's element offset should be processed first");
2431 #endif
2432 }
2433 igvn->hash_insert(addp);
2434 }
2435 }
2436 // Put on IGVN worklist since at least addp's type was changed above.
2437 record_for_optimizer(addp);
2438 return true;
2439 }
2440
2441 //
2442 // Create a new version of orig_phi if necessary. Returns either the newly
2443 // created phi or an existing phi. Sets create_new to indicate whether a new
2444 // phi was created. Cache the last newly created phi in the node map.
2445 //
2446 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2447 Compile *C = _compile;
2448 PhaseGVN* igvn = _igvn;
2449 new_created = false;
2450 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2451 // nothing to do if orig_phi is bottom memory or matches alias_idx
2452 if (phi_alias_idx == alias_idx) {
2453 return orig_phi;
2454 }
2455 // Have we recently created a Phi for this alias index?
2456 PhiNode *result = get_map_phi(orig_phi->_idx);
2457 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2458 return result;
2459 }
2460 // Previous check may fail when the same wide memory Phi was split into Phis
2461 // for different memory slices. Search all Phis for this region.
2462 if (result != NULL) {
2463 Node* region = orig_phi->in(0);
2464 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2465 Node* phi = region->fast_out(i);
2466 if (phi->is_Phi() &&
2467 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2468 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2469 return phi->as_Phi();
2470 }
2471 }
2472 }
2473 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2474 if (C->do_escape_analysis() == true && !C->failing()) {
2475 // Retry compilation without escape analysis.
2476 // If this is the first failure, the sentinel string will "stick"
2477 // to the Compile object, and the C2Compiler will see it and retry.
2478 C->record_failure(C2Compiler::retry_no_escape_analysis());
2479 }
2480 return NULL;
2481 }
2482 orig_phi_worklist.append_if_missing(orig_phi);
2483 const TypePtr *atype = C->get_adr_type(alias_idx);
2484 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2485 C->copy_node_notes_to(result, orig_phi);
2486 igvn->set_type(result, result->bottom_type());
2487 record_for_optimizer(result);
2488 set_map(orig_phi, result);
2489 new_created = true;
2490 return result;
2491 }
2492
2493 //
2494 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2495 // specified alias index.
2496 //
2497 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2498 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2499 Compile *C = _compile;
2500 PhaseGVN* igvn = _igvn;
2501 bool new_phi_created;
2502 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2503 if (!new_phi_created) {
2504 return result;
2505 }
2506 GrowableArray<PhiNode *> phi_list;
2507 GrowableArray<uint> cur_input;
2508 PhiNode *phi = orig_phi;
2509 uint idx = 1;
2510 bool finished = false;
2511 while(!finished) {
2512 while (idx < phi->req()) {
2513 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2514 if (mem != NULL && mem->is_Phi()) {
2515 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2516 if (new_phi_created) {
2517 // found an phi for which we created a new split, push current one on worklist and begin
2518 // processing new one
2519 phi_list.push(phi);
2520 cur_input.push(idx);
2521 phi = mem->as_Phi();
2522 result = newphi;
2523 idx = 1;
2524 continue;
2525 } else {
2526 mem = newphi;
2527 }
2528 }
2529 if (C->failing()) {
2530 return NULL;
2531 }
2532 result->set_req(idx++, mem);
2533 }
2534 #ifdef ASSERT
2535 // verify that the new Phi has an input for each input of the original
2536 assert( phi->req() == result->req(), "must have same number of inputs.");
2537 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2538 #endif
2539 // Check if all new phi's inputs have specified alias index.
2540 // Otherwise use old phi.
2541 for (uint i = 1; i < phi->req(); i++) {
2542 Node* in = result->in(i);
2543 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2544 }
2545 // we have finished processing a Phi, see if there are any more to do
2546 finished = (phi_list.length() == 0 );
2547 if (!finished) {
2548 phi = phi_list.pop();
2549 idx = cur_input.pop();
2550 PhiNode *prev_result = get_map_phi(phi->_idx);
2551 prev_result->set_req(idx++, result);
2552 result = prev_result;
2553 }
2554 }
2555 return result;
2556 }
2557
2558 //
2559 // The next methods are derived from methods in MemNode.
2560 //
2561 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2562 Node *mem = mmem;
2563 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2564 // means an array I have not precisely typed yet. Do not do any
2565 // alias stuff with it any time soon.
2566 if (toop->base() != Type::AnyPtr &&
2567 !(toop->klass() != NULL &&
2568 toop->klass()->is_java_lang_Object() &&
2569 toop->offset() == Type::OffsetBot)) {
2570 mem = mmem->memory_at(alias_idx);
2571 // Update input if it is progress over what we have now
2572 }
2573 return mem;
2574 }
2575
2576 //
2577 // Move memory users to their memory slices.
2578 //
2579 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2580 Compile* C = _compile;
2581 PhaseGVN* igvn = _igvn;
2582 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2583 assert(tp != NULL, "ptr type");
2584 int alias_idx = C->get_alias_index(tp);
2585 int general_idx = C->get_general_index(alias_idx);
2586
2587 // Move users first
2588 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2589 Node* use = n->fast_out(i);
2590 if (use->is_MergeMem()) {
2591 MergeMemNode* mmem = use->as_MergeMem();
2592 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2593 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2594 continue; // Nothing to do
2595 }
2596 // Replace previous general reference to mem node.
2597 uint orig_uniq = C->unique();
2598 Node* m = find_inst_mem(n, general_idx, orig_phis);
2599 assert(orig_uniq == C->unique(), "no new nodes");
2600 mmem->set_memory_at(general_idx, m);
2601 --imax;
2602 --i;
2603 } else if (use->is_MemBar()) {
2604 assert(!use->is_Initialize(), "initializing stores should not be moved");
2605 if (use->req() > MemBarNode::Precedent &&
2606 use->in(MemBarNode::Precedent) == n) {
2607 // Don't move related membars.
2608 record_for_optimizer(use);
2609 continue;
2610 }
2611 tp = use->as_MemBar()->adr_type()->isa_ptr();
2612 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2613 alias_idx == general_idx) {
2614 continue; // Nothing to do
2615 }
2616 // Move to general memory slice.
2617 uint orig_uniq = C->unique();
2618 Node* m = find_inst_mem(n, general_idx, orig_phis);
2619 assert(orig_uniq == C->unique(), "no new nodes");
2620 igvn->hash_delete(use);
2621 imax -= use->replace_edge(n, m);
2622 igvn->hash_insert(use);
2623 record_for_optimizer(use);
2624 --i;
2625 #ifdef ASSERT
2626 } else if (use->is_Mem()) {
2627 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2628 // Don't move related cardmark.
2629 continue;
2630 }
2631 // Memory nodes should have new memory input.
2632 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2633 assert(tp != NULL, "ptr type");
2634 int idx = C->get_alias_index(tp);
2635 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2636 "Following memory nodes should have new memory input or be on the same memory slice");
2637 } else if (use->is_Phi()) {
2638 // Phi nodes should be split and moved already.
2639 tp = use->as_Phi()->adr_type()->isa_ptr();
2640 assert(tp != NULL, "ptr type");
2641 int idx = C->get_alias_index(tp);
2642 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2643 } else {
2644 use->dump();
2645 assert(false, "should not be here");
2646 #endif
2647 }
2648 }
2649 }
2650
2651 //
2652 // Search memory chain of "mem" to find a MemNode whose address
2653 // is the specified alias index.
2654 //
2655 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2656 if (orig_mem == NULL)
2657 return orig_mem;
2658 Compile* C = _compile;
2659 PhaseGVN* igvn = _igvn;
2660 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2661 bool is_instance = (toop != NULL) && toop->is_known_instance();
2662 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2663 Node *prev = NULL;
2664 Node *result = orig_mem;
2665 while (prev != result) {
2666 prev = result;
2667 if (result == start_mem)
2668 break; // hit one of our sentinels
2669 if (result->is_Mem()) {
2670 const Type *at = igvn->type(result->in(MemNode::Address));
2671 if (at == Type::TOP)
2672 break; // Dead
2673 assert (at->isa_ptr() != NULL, "pointer type required.");
2674 int idx = C->get_alias_index(at->is_ptr());
2675 if (idx == alias_idx)
2676 break; // Found
2677 if (!is_instance && (at->isa_oopptr() == NULL ||
2678 !at->is_oopptr()->is_known_instance())) {
2679 break; // Do not skip store to general memory slice.
2680 }
2681 result = result->in(MemNode::Memory);
2682 }
2683 if (!is_instance)
2684 continue; // don't search further for non-instance types
2685 // skip over a call which does not affect this memory slice
2686 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2687 Node *proj_in = result->in(0);
2688 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2689 break; // hit one of our sentinels
2690 } else if (proj_in->is_Call()) {
2691 // ArrayCopy node processed here as well
2692 CallNode *call = proj_in->as_Call();
2693 if (!call->may_modify(toop, igvn)) {
2694 result = call->in(TypeFunc::Memory);
2695 }
2696 } else if (proj_in->is_Initialize()) {
2697 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2698 // Stop if this is the initialization for the object instance which
2699 // which contains this memory slice, otherwise skip over it.
2700 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2701 result = proj_in->in(TypeFunc::Memory);
2702 }
2703 } else if (proj_in->is_MemBar()) {
2704 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2705 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2706 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2707 // clone
2708 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2709 if (ac->may_modify(toop, igvn)) {
2710 break;
2711 }
2712 }
2713 result = proj_in->in(TypeFunc::Memory);
2714 }
2715 } else if (result->is_MergeMem()) {
2716 MergeMemNode *mmem = result->as_MergeMem();
2717 result = step_through_mergemem(mmem, alias_idx, toop);
2718 if (result == mmem->base_memory()) {
2719 // Didn't find instance memory, search through general slice recursively.
2720 result = mmem->memory_at(C->get_general_index(alias_idx));
2721 result = find_inst_mem(result, alias_idx, orig_phis);
2722 if (C->failing()) {
2723 return NULL;
2724 }
2725 mmem->set_memory_at(alias_idx, result);
2726 }
2727 } else if (result->is_Phi() &&
2728 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2729 Node *un = result->as_Phi()->unique_input(igvn);
2730 if (un != NULL) {
2731 orig_phis.append_if_missing(result->as_Phi());
2732 result = un;
2733 } else {
2734 break;
2735 }
2736 } else if (result->is_ClearArray()) {
2737 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2738 // Can not bypass initialization of the instance
2739 // we are looking for.
2740 break;
2741 }
2742 // Otherwise skip it (the call updated 'result' value).
2743 } else if (result->Opcode() == Op_SCMemProj) {
2744 Node* mem = result->in(0);
2745 Node* adr = NULL;
2746 if (mem->is_LoadStore()) {
2747 adr = mem->in(MemNode::Address);
2748 } else {
2749 assert(mem->Opcode() == Op_EncodeISOArray ||
2750 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2751 adr = mem->in(3); // Memory edge corresponds to destination array
2752 }
2753 const Type *at = igvn->type(adr);
2754 if (at != Type::TOP) {
2755 assert(at->isa_ptr() != NULL, "pointer type required.");
2756 int idx = C->get_alias_index(at->is_ptr());
2757 if (idx == alias_idx) {
2758 // Assert in debug mode
2759 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2760 break; // In product mode return SCMemProj node
2761 }
2762 }
2763 result = mem->in(MemNode::Memory);
2764 } else if (result->Opcode() == Op_StrInflatedCopy) {
2765 Node* adr = result->in(3); // Memory edge corresponds to destination array
2766 const Type *at = igvn->type(adr);
2767 if (at != Type::TOP) {
2768 assert(at->isa_ptr() != NULL, "pointer type required.");
2769 int idx = C->get_alias_index(at->is_ptr());
2770 if (idx == alias_idx) {
2771 // Assert in debug mode
2772 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2773 break; // In product mode return SCMemProj node
2774 }
2775 }
2776 result = result->in(MemNode::Memory);
2777 }
2778 }
2779 if (result->is_Phi()) {
2780 PhiNode *mphi = result->as_Phi();
2781 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2782 const TypePtr *t = mphi->adr_type();
2783 if (!is_instance) {
2784 // Push all non-instance Phis on the orig_phis worklist to update inputs
2785 // during Phase 4 if needed.
2786 orig_phis.append_if_missing(mphi);
2787 } else if (C->get_alias_index(t) != alias_idx) {
2788 // Create a new Phi with the specified alias index type.
2789 result = split_memory_phi(mphi, alias_idx, orig_phis);
2790 }
2791 }
2792 // the result is either MemNode, PhiNode, InitializeNode.
2793 return result;
2794 }
2795
2796 //
2797 // Convert the types of unescaped object to instance types where possible,
2798 // propagate the new type information through the graph, and update memory
2799 // edges and MergeMem inputs to reflect the new type.
2800 //
2801 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2802 // The processing is done in 4 phases:
2803 //
2804 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2805 // types for the CheckCastPP for allocations where possible.
2806 // Propagate the new types through users as follows:
2807 // casts and Phi: push users on alloc_worklist
2808 // AddP: cast Base and Address inputs to the instance type
2809 // push any AddP users on alloc_worklist and push any memnode
2810 // users onto memnode_worklist.
2811 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2812 // search the Memory chain for a store with the appropriate type
2813 // address type. If a Phi is found, create a new version with
2814 // the appropriate memory slices from each of the Phi inputs.
2815 // For stores, process the users as follows:
2816 // MemNode: push on memnode_worklist
2817 // MergeMem: push on mergemem_worklist
2818 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2819 // moving the first node encountered of each instance type to the
2820 // the input corresponding to its alias index.
2821 // appropriate memory slice.
2822 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2823 //
2824 // In the following example, the CheckCastPP nodes are the cast of allocation
2825 // results and the allocation of node 29 is unescaped and eligible to be an
2826 // instance type.
2827 //
2828 // We start with:
2829 //
2830 // 7 Parm #memory
2831 // 10 ConI "12"
2832 // 19 CheckCastPP "Foo"
2833 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2834 // 29 CheckCastPP "Foo"
2835 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2836 //
2837 // 40 StoreP 25 7 20 ... alias_index=4
2838 // 50 StoreP 35 40 30 ... alias_index=4
2839 // 60 StoreP 45 50 20 ... alias_index=4
2840 // 70 LoadP _ 60 30 ... alias_index=4
2841 // 80 Phi 75 50 60 Memory alias_index=4
2842 // 90 LoadP _ 80 30 ... alias_index=4
2843 // 100 LoadP _ 80 20 ... alias_index=4
2844 //
2845 //
2846 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2847 // and creating a new alias index for node 30. This gives:
2848 //
2849 // 7 Parm #memory
2850 // 10 ConI "12"
2851 // 19 CheckCastPP "Foo"
2852 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2853 // 29 CheckCastPP "Foo" iid=24
2854 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2855 //
2856 // 40 StoreP 25 7 20 ... alias_index=4
2857 // 50 StoreP 35 40 30 ... alias_index=6
2858 // 60 StoreP 45 50 20 ... alias_index=4
2859 // 70 LoadP _ 60 30 ... alias_index=6
2860 // 80 Phi 75 50 60 Memory alias_index=4
2861 // 90 LoadP _ 80 30 ... alias_index=6
2862 // 100 LoadP _ 80 20 ... alias_index=4
2863 //
2864 // In phase 2, new memory inputs are computed for the loads and stores,
2865 // And a new version of the phi is created. In phase 4, the inputs to
2866 // node 80 are updated and then the memory nodes are updated with the
2867 // values computed in phase 2. This results in:
2868 //
2869 // 7 Parm #memory
2870 // 10 ConI "12"
2871 // 19 CheckCastPP "Foo"
2872 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2873 // 29 CheckCastPP "Foo" iid=24
2874 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2875 //
2876 // 40 StoreP 25 7 20 ... alias_index=4
2877 // 50 StoreP 35 7 30 ... alias_index=6
2878 // 60 StoreP 45 40 20 ... alias_index=4
2879 // 70 LoadP _ 50 30 ... alias_index=6
2880 // 80 Phi 75 40 60 Memory alias_index=4
2881 // 120 Phi 75 50 50 Memory alias_index=6
2882 // 90 LoadP _ 120 30 ... alias_index=6
2883 // 100 LoadP _ 80 20 ... alias_index=4
2884 //
2885 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2886 GrowableArray<Node *> memnode_worklist;
2887 GrowableArray<PhiNode *> orig_phis;
2888 PhaseIterGVN *igvn = _igvn;
2889 uint new_index_start = (uint) _compile->num_alias_types();
2890 Arena* arena = Thread::current()->resource_area();
2891 VectorSet visited(arena);
2892 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2893 uint unique_old = _compile->unique();
2894
2895 // Phase 1: Process possible allocations from alloc_worklist.
2896 // Create instance types for the CheckCastPP for allocations where possible.
2897 //
2898 // (Note: don't forget to change the order of the second AddP node on
2899 // the alloc_worklist if the order of the worklist processing is changed,
2900 // see the comment in find_second_addp().)
2901 //
2902 while (alloc_worklist.length() != 0) {
2903 Node *n = alloc_worklist.pop();
2904 uint ni = n->_idx;
2905 if (n->is_Call()) {
2906 CallNode *alloc = n->as_Call();
2907 // copy escape information to call node
2908 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2909 PointsToNode::EscapeState es = ptn->escape_state();
2910 // We have an allocation or call which returns a Java object,
2911 // see if it is unescaped.
2912 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2913 continue;
2914 // Find CheckCastPP for the allocate or for the return value of a call
2915 n = alloc->result_cast();
2916 if (n == NULL) { // No uses except Initialize node
2917 if (alloc->is_Allocate()) {
2918 // Set the scalar_replaceable flag for allocation
2919 // so it could be eliminated if it has no uses.
2920 alloc->as_Allocate()->_is_scalar_replaceable = true;
2921 }
2922 if (alloc->is_CallStaticJava()) {
2923 // Set the scalar_replaceable flag for boxing method
2924 // so it could be eliminated if it has no uses.
2925 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2926 }
2927 continue;
2928 }
2929 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2930 assert(!alloc->is_Allocate(), "allocation should have unique type");
2931 continue;
2932 }
2933
2934 // The inline code for Object.clone() casts the allocation result to
2935 // java.lang.Object and then to the actual type of the allocated
2936 // object. Detect this case and use the second cast.
2937 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2938 // the allocation result is cast to java.lang.Object and then
2939 // to the actual Array type.
2940 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2941 && (alloc->is_AllocateArray() ||
2942 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2943 Node *cast2 = NULL;
2944 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2945 Node *use = n->fast_out(i);
2946 if (use->is_CheckCastPP()) {
2947 cast2 = use;
2948 break;
2949 }
2950 }
2951 if (cast2 != NULL) {
2952 n = cast2;
2953 } else {
2954 // Non-scalar replaceable if the allocation type is unknown statically
2955 // (reflection allocation), the object can't be restored during
2956 // deoptimization without precise type.
2957 continue;
2958 }
2959 }
2960
2961 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2962 if (t == NULL)
2963 continue; // not a TypeOopPtr
2964 if (!t->klass_is_exact())
2965 continue; // not an unique type
2966
2967 if (alloc->is_Allocate()) {
2968 // Set the scalar_replaceable flag for allocation
2969 // so it could be eliminated.
2970 alloc->as_Allocate()->_is_scalar_replaceable = true;
2971 }
2972 if (alloc->is_CallStaticJava()) {
2973 // Set the scalar_replaceable flag for boxing method
2974 // so it could be eliminated.
2975 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2976 }
2977 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2978 // in order for an object to be scalar-replaceable, it must be:
2979 // - a direct allocation (not a call returning an object)
2980 // - non-escaping
2981 // - eligible to be a unique type
2982 // - not determined to be ineligible by escape analysis
2983 set_map(alloc, n);
2984 set_map(n, alloc);
2985 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2986 igvn->hash_delete(n);
2987 igvn->set_type(n, tinst);
2988 n->raise_bottom_type(tinst);
2989 igvn->hash_insert(n);
2990 record_for_optimizer(n);
2991 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2992
2993 // First, put on the worklist all Field edges from Connection Graph
2994 // which is more accurate than putting immediate users from Ideal Graph.
2995 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2996 PointsToNode* tgt = e.get();
2997 if (tgt->is_Arraycopy()) {
2998 continue;
2999 }
3000 Node* use = tgt->ideal_node();
3001 assert(tgt->is_Field() && use->is_AddP(),
3002 "only AddP nodes are Field edges in CG");
3003 if (use->outcnt() > 0) { // Don't process dead nodes
3004 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3005 if (addp2 != NULL) {
3006 assert(alloc->is_AllocateArray(),"array allocation was expected");
3007 alloc_worklist.append_if_missing(addp2);
3008 }
3009 alloc_worklist.append_if_missing(use);
3010 }
3011 }
3012
3013 // An allocation may have an Initialize which has raw stores. Scan
3014 // the users of the raw allocation result and push AddP users
3015 // on alloc_worklist.
3016 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
3017 assert (raw_result != NULL, "must have an allocation result");
3018 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3019 Node *use = raw_result->fast_out(i);
3020 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3021 Node* addp2 = find_second_addp(use, raw_result);
3022 if (addp2 != NULL) {
3023 assert(alloc->is_AllocateArray(),"array allocation was expected");
3024 alloc_worklist.append_if_missing(addp2);
3025 }
3026 alloc_worklist.append_if_missing(use);
3027 } else if (use->is_MemBar()) {
3028 memnode_worklist.append_if_missing(use);
3029 }
3030 }
3031 }
3032 } else if (n->is_AddP()) {
3033 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3034 if (jobj == NULL || jobj == phantom_obj) {
3035 #ifdef ASSERT
3036 ptnode_adr(get_addp_base(n)->_idx)->dump();
3037 ptnode_adr(n->_idx)->dump();
3038 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3039 #endif
3040 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3041 return;
3042 }
3043 Node *base = get_map(jobj->idx()); // CheckCastPP node
3044 if (!split_AddP(n, base)) continue; // wrong type from dead path
3045 } else if (n->is_Phi() ||
3046 n->is_CheckCastPP() ||
3047 n->is_EncodeP() ||
3048 n->is_DecodeN() ||
3049 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3050 if (visited.test_set(n->_idx)) {
3051 assert(n->is_Phi(), "loops only through Phi's");
3052 continue; // already processed
3053 }
3054 JavaObjectNode* jobj = unique_java_object(n);
3055 if (jobj == NULL || jobj == phantom_obj) {
3056 #ifdef ASSERT
3057 ptnode_adr(n->_idx)->dump();
3058 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3059 #endif
3060 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3061 return;
3062 } else {
3063 Node *val = get_map(jobj->idx()); // CheckCastPP node
3064 TypeNode *tn = n->as_Type();
3065 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3066 assert(tinst != NULL && tinst->is_known_instance() &&
3067 tinst->instance_id() == jobj->idx() , "instance type expected.");
3068
3069 const Type *tn_type = igvn->type(tn);
3070 const TypeOopPtr *tn_t;
3071 if (tn_type->isa_narrowoop()) {
3072 tn_t = tn_type->make_ptr()->isa_oopptr();
3073 } else {
3074 tn_t = tn_type->isa_oopptr();
3075 }
3076 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3077 if (tn_type->isa_narrowoop()) {
3078 tn_type = tinst->make_narrowoop();
3079 } else {
3080 tn_type = tinst;
3081 }
3082 igvn->hash_delete(tn);
3083 igvn->set_type(tn, tn_type);
3084 tn->set_type(tn_type);
3085 igvn->hash_insert(tn);
3086 record_for_optimizer(n);
3087 } else {
3088 assert(tn_type == TypePtr::NULL_PTR ||
3089 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3090 "unexpected type");
3091 continue; // Skip dead path with different type
3092 }
3093 }
3094 } else {
3095 debug_only(n->dump();)
3096 assert(false, "EA: unexpected node");
3097 continue;
3098 }
3099 // push allocation's users on appropriate worklist
3100 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3101 Node *use = n->fast_out(i);
3102 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3103 // Load/store to instance's field
3104 memnode_worklist.append_if_missing(use);
3105 } else if (use->is_MemBar()) {
3106 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3107 memnode_worklist.append_if_missing(use);
3108 }
3109 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3110 Node* addp2 = find_second_addp(use, n);
3111 if (addp2 != NULL) {
3112 alloc_worklist.append_if_missing(addp2);
3113 }
3114 alloc_worklist.append_if_missing(use);
3115 } else if (use->is_Phi() ||
3116 use->is_CheckCastPP() ||
3117 use->is_EncodeNarrowPtr() ||
3118 use->is_DecodeNarrowPtr() ||
3119 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3120 alloc_worklist.append_if_missing(use);
3121 #ifdef ASSERT
3122 } else if (use->is_Mem()) {
3123 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3124 } else if (use->is_MergeMem()) {
3125 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3126 } else if (use->is_SafePoint()) {
3127 // Look for MergeMem nodes for calls which reference unique allocation
3128 // (through CheckCastPP nodes) even for debug info.
3129 Node* m = use->in(TypeFunc::Memory);
3130 if (m->is_MergeMem()) {
3131 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3132 }
3133 } else if (use->Opcode() == Op_EncodeISOArray) {
3134 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3135 // EncodeISOArray overwrites destination array
3136 memnode_worklist.append_if_missing(use);
3137 }
3138 } else {
3139 uint op = use->Opcode();
3140 if ((use->in(MemNode::Memory) == n) &&
3141 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3142 // They overwrite memory edge corresponding to destination array,
3143 memnode_worklist.append_if_missing(use);
3144 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3145 op == Op_CastP2X || op == Op_StoreCM ||
3146 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3147 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3148 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3149 op == Op_ValueType)) {
3150 n->dump();
3151 use->dump();
3152 assert(false, "EA: missing allocation reference path");
3153 }
3154 #endif
3155 }
3156 }
3157
3158 }
3159
3160 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3161 // type, record it in the ArrayCopy node so we know what memory this
3162 // node uses/modified.
3163 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3164 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3165 Node* dest = ac->in(ArrayCopyNode::Dest);
3166 if (dest->is_AddP()) {
3167 dest = get_addp_base(dest);
3168 }
3169 JavaObjectNode* jobj = unique_java_object(dest);
3170 if (jobj != NULL) {
3171 Node *base = get_map(jobj->idx());
3172 if (base != NULL) {
3173 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3174 ac->_dest_type = base_t;
3175 }
3176 }
3177 Node* src = ac->in(ArrayCopyNode::Src);
3178 if (src->is_AddP()) {
3179 src = get_addp_base(src);
3180 }
3181 jobj = unique_java_object(src);
3182 if (jobj != NULL) {
3183 Node* base = get_map(jobj->idx());
3184 if (base != NULL) {
3185 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3186 ac->_src_type = base_t;
3187 }
3188 }
3189 }
3190
3191 // New alias types were created in split_AddP().
3192 uint new_index_end = (uint) _compile->num_alias_types();
3193 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3194
3195 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3196 // compute new values for Memory inputs (the Memory inputs are not
3197 // actually updated until phase 4.)
3198 if (memnode_worklist.length() == 0)
3199 return; // nothing to do
3200 while (memnode_worklist.length() != 0) {
3201 Node *n = memnode_worklist.pop();
3202 if (visited.test_set(n->_idx))
3203 continue;
3204 if (n->is_Phi() || n->is_ClearArray()) {
3205 // we don't need to do anything, but the users must be pushed
3206 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3207 // we don't need to do anything, but the users must be pushed
3208 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3209 if (n == NULL)
3210 continue;
3211 } else if (n->Opcode() == Op_StrCompressedCopy ||
3212 n->Opcode() == Op_EncodeISOArray) {
3213 // get the memory projection
3214 n = n->find_out_with(Op_SCMemProj);
3215 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3216 } else {
3217 assert(n->is_Mem(), "memory node required.");
3218 Node *addr = n->in(MemNode::Address);
3219 const Type *addr_t = igvn->type(addr);
3220 if (addr_t == Type::TOP)
3221 continue;
3222 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3223 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3224 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3225 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3226 if (_compile->failing()) {
3227 return;
3228 }
3229 if (mem != n->in(MemNode::Memory)) {
3230 // We delay the memory edge update since we need old one in
3231 // MergeMem code below when instances memory slices are separated.
3232 set_map(n, mem);
3233 }
3234 if (n->is_Load()) {
3235 continue; // don't push users
3236 } else if (n->is_LoadStore()) {
3237 // get the memory projection
3238 n = n->find_out_with(Op_SCMemProj);
3239 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3240 }
3241 }
3242 // push user on appropriate worklist
3243 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3244 Node *use = n->fast_out(i);
3245 if (use->is_Phi() || use->is_ClearArray()) {
3246 memnode_worklist.append_if_missing(use);
3247 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3248 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3249 continue;
3250 memnode_worklist.append_if_missing(use);
3251 } else if (use->is_MemBar()) {
3252 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3253 memnode_worklist.append_if_missing(use);
3254 }
3255 #ifdef ASSERT
3256 } else if(use->is_Mem()) {
3257 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3258 } else if (use->is_MergeMem()) {
3259 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3260 } else if (use->Opcode() == Op_EncodeISOArray) {
3261 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3262 // EncodeISOArray overwrites destination array
3263 memnode_worklist.append_if_missing(use);
3264 }
3265 } else {
3266 uint op = use->Opcode();
3267 if ((use->in(MemNode::Memory) == n) &&
3268 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3269 // They overwrite memory edge corresponding to destination array,
3270 memnode_worklist.append_if_missing(use);
3271 } else if (!(op == Op_StoreCM ||
3272 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3273 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3274 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3275 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3276 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3277 n->dump();
3278 use->dump();
3279 assert(false, "EA: missing memory path");
3280 }
3281 #endif
3282 }
3283 }
3284 }
3285
3286 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3287 // Walk each memory slice moving the first node encountered of each
3288 // instance type to the the input corresponding to its alias index.
3289 uint length = _mergemem_worklist.length();
3290 for( uint next = 0; next < length; ++next ) {
3291 MergeMemNode* nmm = _mergemem_worklist.at(next);
3292 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3293 // Note: we don't want to use MergeMemStream here because we only want to
3294 // scan inputs which exist at the start, not ones we add during processing.
3295 // Note 2: MergeMem may already contains instance memory slices added
3296 // during find_inst_mem() call when memory nodes were processed above.
3297 igvn->hash_delete(nmm);
3298 uint nslices = MIN2(nmm->req(), new_index_start);
3299 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3300 Node* mem = nmm->in(i);
3301 Node* cur = NULL;
3302 if (mem == NULL || mem->is_top())
3303 continue;
3304 // First, update mergemem by moving memory nodes to corresponding slices
3305 // if their type became more precise since this mergemem was created.
3306 while (mem->is_Mem()) {
3307 const Type *at = igvn->type(mem->in(MemNode::Address));
3308 if (at != Type::TOP) {
3309 assert (at->isa_ptr() != NULL, "pointer type required.");
3310 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3311 if (idx == i) {
3312 if (cur == NULL)
3313 cur = mem;
3314 } else {
3315 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3316 nmm->set_memory_at(idx, mem);
3317 }
3318 }
3319 }
3320 mem = mem->in(MemNode::Memory);
3321 }
3322 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3323 // Find any instance of the current type if we haven't encountered
3324 // already a memory slice of the instance along the memory chain.
3325 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3326 if((uint)_compile->get_general_index(ni) == i) {
3327 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3328 if (nmm->is_empty_memory(m)) {
3329 Node* result = find_inst_mem(mem, ni, orig_phis);
3330 if (_compile->failing()) {
3331 return;
3332 }
3333 nmm->set_memory_at(ni, result);
3334 }
3335 }
3336 }
3337 }
3338 // Find the rest of instances values
3339 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3340 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3341 Node* result = step_through_mergemem(nmm, ni, tinst);
3342 if (result == nmm->base_memory()) {
3343 // Didn't find instance memory, search through general slice recursively.
3344 result = nmm->memory_at(_compile->get_general_index(ni));
3345 result = find_inst_mem(result, ni, orig_phis);
3346 if (_compile->failing()) {
3347 return;
3348 }
3349 nmm->set_memory_at(ni, result);
3350 }
3351 }
3352 igvn->hash_insert(nmm);
3353 record_for_optimizer(nmm);
3354 }
3355
3356 // Phase 4: Update the inputs of non-instance memory Phis and
3357 // the Memory input of memnodes
3358 // First update the inputs of any non-instance Phi's from
3359 // which we split out an instance Phi. Note we don't have
3360 // to recursively process Phi's encounted on the input memory
3361 // chains as is done in split_memory_phi() since they will
3362 // also be processed here.
3363 for (int j = 0; j < orig_phis.length(); j++) {
3364 PhiNode *phi = orig_phis.at(j);
3365 int alias_idx = _compile->get_alias_index(phi->adr_type());
3366 igvn->hash_delete(phi);
3367 for (uint i = 1; i < phi->req(); i++) {
3368 Node *mem = phi->in(i);
3369 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3370 if (_compile->failing()) {
3371 return;
3372 }
3373 if (mem != new_mem) {
3374 phi->set_req(i, new_mem);
3375 }
3376 }
3377 igvn->hash_insert(phi);
3378 record_for_optimizer(phi);
3379 }
3380
3381 // Update the memory inputs of MemNodes with the value we computed
3382 // in Phase 2 and move stores memory users to corresponding memory slices.
3383 // Disable memory split verification code until the fix for 6984348.
3384 // Currently it produces false negative results since it does not cover all cases.
3385 #if 0 // ifdef ASSERT
3386 visited.Reset();
3387 Node_Stack old_mems(arena, _compile->unique() >> 2);
3388 #endif
3389 for (uint i = 0; i < ideal_nodes.size(); i++) {
3390 Node* n = ideal_nodes.at(i);
3391 Node* nmem = get_map(n->_idx);
3392 assert(nmem != NULL, "sanity");
3393 if (n->is_Mem()) {
3394 #if 0 // ifdef ASSERT
3395 Node* old_mem = n->in(MemNode::Memory);
3396 if (!visited.test_set(old_mem->_idx)) {
3397 old_mems.push(old_mem, old_mem->outcnt());
3398 }
3399 #endif
3400 assert(n->in(MemNode::Memory) != nmem, "sanity");
3401 if (!n->is_Load()) {
3402 // Move memory users of a store first.
3403 move_inst_mem(n, orig_phis);
3404 }
3405 // Now update memory input
3406 igvn->hash_delete(n);
3407 n->set_req(MemNode::Memory, nmem);
3408 igvn->hash_insert(n);
3409 record_for_optimizer(n);
3410 } else {
3411 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3412 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3413 }
3414 }
3415 #if 0 // ifdef ASSERT
3416 // Verify that memory was split correctly
3417 while (old_mems.is_nonempty()) {
3418 Node* old_mem = old_mems.node();
3419 uint old_cnt = old_mems.index();
3420 old_mems.pop();
3421 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3422 }
3423 #endif
3424 }
3425
3426 #ifndef PRODUCT
3427 static const char *node_type_names[] = {
3428 "UnknownType",
3429 "JavaObject",
3430 "LocalVar",
3431 "Field",
3432 "Arraycopy"
3433 };
3434
3435 static const char *esc_names[] = {
3436 "UnknownEscape",
3437 "NoEscape",
3438 "ArgEscape",
3439 "GlobalEscape"
3440 };
3441
3442 void PointsToNode::dump(bool print_state) const {
3443 NodeType nt = node_type();
3444 tty->print("%s ", node_type_names[(int) nt]);
3445 if (print_state) {
3446 EscapeState es = escape_state();
3447 EscapeState fields_es = fields_escape_state();
3448 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3449 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3450 tty->print("NSR ");
3451 }
3452 if (is_Field()) {
3453 FieldNode* f = (FieldNode*)this;
3454 if (f->is_oop())
3455 tty->print("oop ");
3456 if (f->offset() > 0)
3457 tty->print("+%d ", f->offset());
3458 tty->print("(");
3459 for (BaseIterator i(f); i.has_next(); i.next()) {
3460 PointsToNode* b = i.get();
3461 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3462 }
3463 tty->print(" )");
3464 }
3465 tty->print("[");
3466 for (EdgeIterator i(this); i.has_next(); i.next()) {
3467 PointsToNode* e = i.get();
3468 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3469 }
3470 tty->print(" [");
3471 for (UseIterator i(this); i.has_next(); i.next()) {
3472 PointsToNode* u = i.get();
3473 bool is_base = false;
3474 if (PointsToNode::is_base_use(u)) {
3475 is_base = true;
3476 u = PointsToNode::get_use_node(u)->as_Field();
3477 }
3478 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3479 }
3480 tty->print(" ]] ");
3481 if (_node == NULL)
3482 tty->print_cr("<null>");
3483 else
3484 _node->dump();
3485 }
3486
3487 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3488 bool first = true;
3489 int ptnodes_length = ptnodes_worklist.length();
3490 for (int i = 0; i < ptnodes_length; i++) {
3491 PointsToNode *ptn = ptnodes_worklist.at(i);
3492 if (ptn == NULL || !ptn->is_JavaObject())
3493 continue;
3494 PointsToNode::EscapeState es = ptn->escape_state();
3495 if ((es != PointsToNode::NoEscape) && !Verbose) {
3496 continue;
3497 }
3498 Node* n = ptn->ideal_node();
3499 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3500 n->as_CallStaticJava()->is_boxing_method())) {
3501 if (first) {
3502 tty->cr();
3503 tty->print("======== Connection graph for ");
3504 _compile->method()->print_short_name();
3505 tty->cr();
3506 first = false;
3507 }
3508 ptn->dump();
3509 // Print all locals and fields which reference this allocation
3510 for (UseIterator j(ptn); j.has_next(); j.next()) {
3511 PointsToNode* use = j.get();
3512 if (use->is_LocalVar()) {
3513 use->dump(Verbose);
3514 } else if (Verbose) {
3515 use->dump();
3516 }
3517 }
3518 tty->cr();
3519 }
3520 }
3521 }
3522 #endif