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 "gc/shenandoah/brooksPointer.hpp"
29 #include "libadt/vectset.hpp"
30 #include "memory/allocation.hpp"
31 #include "opto/c2compiler.hpp"
32 #include "opto/arraycopynode.hpp"
33 #include "opto/callnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/compile.hpp"
36 #include "opto/escape.hpp"
37 #include "opto/phaseX.hpp"
38 #include "opto/movenode.hpp"
39 #include "opto/rootnode.hpp"
40 #include "opto/shenandoahSupport.hpp"
41
42 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
43 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
44 _in_worklist(C->comp_arena()),
45 _next_pidx(0),
46 _collecting(true),
47 _verify(false),
48 _compile(C),
49 _igvn(igvn),
50 _node_map(C->comp_arena()) {
51 // Add unknown java object.
52 add_java_object(C->top(), PointsToNode::GlobalEscape);
53 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
54 // Add ConP(#NULL) and ConN(#NULL) nodes.
55 Node* oop_null = igvn->zerocon(T_OBJECT);
56 assert(oop_null->_idx < nodes_size(), "should be created already");
57 add_java_object(oop_null, PointsToNode::NoEscape);
58 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
59 if (UseCompressedOops) {
60 Node* noop_null = igvn->zerocon(T_NARROWOOP);
61 assert(noop_null->_idx < nodes_size(), "should be created already");
62 map_ideal_node(noop_null, null_obj);
63 }
64 _pcmp_neq = NULL; // Should be initialized
65 _pcmp_eq = NULL;
66 }
67
68 bool ConnectionGraph::has_candidates(Compile *C) {
69 // EA brings benefits only when the code has allocations and/or locks which
70 // are represented by ideal Macro nodes.
71 int cnt = C->macro_count();
72 for (int i = 0; i < cnt; i++) {
73 Node *n = C->macro_node(i);
74 if (n->is_Allocate())
75 return true;
76 if (n->is_Lock()) {
77 Node* obj = n->as_Lock()->obj_node()->uncast();
78 if (!(obj->is_Parm() || obj->is_Con()))
79 return true;
80 }
81 if (n->is_CallStaticJava() &&
82 n->as_CallStaticJava()->is_boxing_method()) {
83 return true;
84 }
85 }
86 return false;
87 }
88
89 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
90 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
91 ResourceMark rm;
92
93 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
94 // to create space for them in ConnectionGraph::_nodes[].
95 Node* oop_null = igvn->zerocon(T_OBJECT);
96 Node* noop_null = igvn->zerocon(T_NARROWOOP);
97 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
98 // Perform escape analysis
99 if (congraph->compute_escape()) {
100 // There are non escaping objects.
101 C->set_congraph(congraph);
102 }
103 // Cleanup.
104 if (oop_null->outcnt() == 0)
105 igvn->hash_delete(oop_null);
106 if (noop_null->outcnt() == 0)
107 igvn->hash_delete(noop_null);
108 }
109
110 bool ConnectionGraph::compute_escape() {
111 Compile* C = _compile;
112 PhaseGVN* igvn = _igvn;
113
114 // Worklists used by EA.
115 Unique_Node_List delayed_worklist;
116 GrowableArray<Node*> alloc_worklist;
117 GrowableArray<Node*> ptr_cmp_worklist;
118 GrowableArray<Node*> storestore_worklist;
119 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
120 GrowableArray<PointsToNode*> ptnodes_worklist;
121 GrowableArray<JavaObjectNode*> java_objects_worklist;
122 GrowableArray<JavaObjectNode*> non_escaped_worklist;
123 GrowableArray<FieldNode*> oop_fields_worklist;
124 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
125
126 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
127
128 // 1. Populate Connection Graph (CG) with PointsTo nodes.
129 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
130 // Initialize worklist
131 if (C->root() != NULL) {
132 ideal_nodes.push(C->root());
133 }
134 // Processed ideal nodes are unique on ideal_nodes list
135 // but several ideal nodes are mapped to the phantom_obj.
136 // To avoid duplicated entries on the following worklists
137 // add the phantom_obj only once to them.
138 ptnodes_worklist.append(phantom_obj);
139 java_objects_worklist.append(phantom_obj);
140 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
141 Node* n = ideal_nodes.at(next);
142 // Create PointsTo nodes and add them to Connection Graph. Called
143 // only once per ideal node since ideal_nodes is Unique_Node list.
144 add_node_to_connection_graph(n, &delayed_worklist);
145 PointsToNode* ptn = ptnode_adr(n->_idx);
146 if (ptn != NULL && ptn != phantom_obj) {
147 ptnodes_worklist.append(ptn);
148 if (ptn->is_JavaObject()) {
149 java_objects_worklist.append(ptn->as_JavaObject());
150 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
151 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
152 // Only allocations and java static calls results are interesting.
153 non_escaped_worklist.append(ptn->as_JavaObject());
154 }
155 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
156 oop_fields_worklist.append(ptn->as_Field());
157 }
158 }
159 if (n->is_MergeMem()) {
160 // Collect all MergeMem nodes to add memory slices for
161 // scalar replaceable objects in split_unique_types().
162 _mergemem_worklist.append(n->as_MergeMem());
163 } else if (OptimizePtrCompare && n->is_Cmp() &&
164 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
165 // Collect compare pointers nodes.
166 ptr_cmp_worklist.append(n);
167 } else if (n->is_MemBarStoreStore()) {
168 // Collect all MemBarStoreStore nodes so that depending on the
169 // escape status of the associated Allocate node some of them
170 // may be eliminated.
171 storestore_worklist.append(n);
172 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
173 (n->req() > MemBarNode::Precedent)) {
174 record_for_optimizer(n);
175 #ifdef ASSERT
176 } else if (n->is_AddP()) {
177 // Collect address nodes for graph verification.
178 addp_worklist.append(n);
179 #endif
180 } else if (n->is_ArrayCopy()) {
181 // Keep a list of ArrayCopy nodes so if one of its input is non
182 // escaping, we can record a unique type
183 arraycopy_worklist.append(n->as_ArrayCopy());
184 }
185 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
186 Node* m = n->fast_out(i); // Get user
187 ideal_nodes.push(m);
188 }
189 }
190 if (non_escaped_worklist.length() == 0) {
191 _collecting = false;
192 return false; // Nothing to do.
193 }
194 // Add final simple edges to graph.
195 while(delayed_worklist.size() > 0) {
196 Node* n = delayed_worklist.pop();
197 add_final_edges(n);
198 }
199 int ptnodes_length = ptnodes_worklist.length();
200
201 #ifdef ASSERT
202 if (VerifyConnectionGraph) {
203 // Verify that no new simple edges could be created and all
204 // local vars has edges.
205 _verify = true;
206 for (int next = 0; next < ptnodes_length; ++next) {
207 PointsToNode* ptn = ptnodes_worklist.at(next);
208 add_final_edges(ptn->ideal_node());
209 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
210 ptn->dump();
211 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
212 }
213 }
214 _verify = false;
215 }
216 #endif
217 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
218 // processing, calls to CI to resolve symbols (types, fields, methods)
219 // referenced in bytecode. During symbol resolution VM may throw
220 // an exception which CI cleans and converts to compilation failure.
221 if (C->failing()) return false;
222
223 // 2. Finish Graph construction by propagating references to all
224 // java objects through graph.
225 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
226 java_objects_worklist, oop_fields_worklist)) {
227 // All objects escaped or hit time or iterations limits.
228 _collecting = false;
229 return false;
230 }
231
232 // 3. Adjust scalar_replaceable state of nonescaping objects and push
233 // scalar replaceable allocations on alloc_worklist for processing
234 // in split_unique_types().
235 int non_escaped_length = non_escaped_worklist.length();
236 for (int next = 0; next < non_escaped_length; next++) {
237 JavaObjectNode* ptn = non_escaped_worklist.at(next);
238 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
239 Node* n = ptn->ideal_node();
240 if (n->is_Allocate()) {
241 n->as_Allocate()->_is_non_escaping = noescape;
242 }
243 if (n->is_CallStaticJava()) {
244 n->as_CallStaticJava()->_is_non_escaping = noescape;
245 }
246 if (noescape && ptn->scalar_replaceable()) {
247 adjust_scalar_replaceable_state(ptn);
248 if (ptn->scalar_replaceable()) {
249 alloc_worklist.append(ptn->ideal_node());
250 }
251 }
252 }
253
254 #ifdef ASSERT
255 if (VerifyConnectionGraph) {
256 // Verify that graph is complete - no new edges could be added or needed.
257 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
258 java_objects_worklist, addp_worklist);
259 }
260 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
261 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
262 null_obj->edge_count() == 0 &&
263 !null_obj->arraycopy_src() &&
264 !null_obj->arraycopy_dst(), "sanity");
265 #endif
266
267 _collecting = false;
268
269 } // TracePhase t3("connectionGraph")
270
271 // 4. Optimize ideal graph based on EA information.
272 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
273 if (has_non_escaping_obj) {
274 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
275 }
276
277 #ifndef PRODUCT
278 if (PrintEscapeAnalysis) {
279 dump(ptnodes_worklist); // Dump ConnectionGraph
280 }
281 #endif
282
283 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
284 #ifdef ASSERT
285 if (VerifyConnectionGraph) {
286 int alloc_length = alloc_worklist.length();
287 for (int next = 0; next < alloc_length; ++next) {
288 Node* n = alloc_worklist.at(next);
289 PointsToNode* ptn = ptnode_adr(n->_idx);
290 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
291 }
292 }
293 #endif
294
295 // 5. Separate memory graph for scalar replaceable allcations.
296 if (has_scalar_replaceable_candidates &&
297 C->AliasLevel() >= 3 && EliminateAllocations) {
298 // Now use the escape information to create unique types for
299 // scalar replaceable objects.
300 split_unique_types(alloc_worklist, arraycopy_worklist);
301 if (C->failing()) return false;
302 C->print_method(PHASE_AFTER_EA, 2);
303
304 #ifdef ASSERT
305 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
306 tty->print("=== No allocations eliminated for ");
307 C->method()->print_short_name();
308 if(!EliminateAllocations) {
309 tty->print(" since EliminateAllocations is off ===");
310 } else if(!has_scalar_replaceable_candidates) {
311 tty->print(" since there are no scalar replaceable candidates ===");
312 } else if(C->AliasLevel() < 3) {
313 tty->print(" since AliasLevel < 3 ===");
314 }
315 tty->cr();
316 #endif
317 }
318 return has_non_escaping_obj;
319 }
320
321 // Utility function for nodes that load an object
322 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
323 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
324 // ThreadLocal has RawPtr type.
325 const Type* t = _igvn->type(n);
326 if (t->make_ptr() != NULL) {
327 Node* adr = n->in(MemNode::Address);
328 #ifdef ASSERT
329 if (!adr->is_AddP()) {
330 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
331 } else {
332 assert((ptnode_adr(adr->_idx) == NULL ||
333 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
334 }
335 #endif
336 add_local_var_and_edge(n, PointsToNode::NoEscape,
337 adr, delayed_worklist);
338 }
339 }
340
341 // Populate Connection Graph with PointsTo nodes and create simple
342 // connection graph edges.
343 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
344 assert(!_verify, "this method should not be called for verification");
345 PhaseGVN* igvn = _igvn;
346 uint n_idx = n->_idx;
347 PointsToNode* n_ptn = ptnode_adr(n_idx);
348 if (n_ptn != NULL)
349 return; // No need to redefine PointsTo node during first iteration.
350
351 if (n->is_Call()) {
352 // Arguments to allocation and locking don't escape.
353 if (n->is_AbstractLock()) {
354 // Put Lock and Unlock nodes on IGVN worklist to process them during
355 // first IGVN optimization when escape information is still available.
356 record_for_optimizer(n);
357 } else if (n->is_Allocate()) {
358 add_call_node(n->as_Call());
359 record_for_optimizer(n);
360 } else {
361 if (n->is_CallStaticJava()) {
362 const char* name = n->as_CallStaticJava()->_name;
363 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
364 return; // Skip uncommon traps
365 }
366 // Don't mark as processed since call's arguments have to be processed.
367 delayed_worklist->push(n);
368 // Check if a call returns an object.
369 if ((n->as_Call()->returns_pointer() &&
370 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
371 (n->is_CallStaticJava() &&
372 n->as_CallStaticJava()->is_boxing_method())) {
373 add_call_node(n->as_Call());
374 }
375 }
376 return;
377 }
378 // Put this check here to process call arguments since some call nodes
379 // point to phantom_obj.
380 if (n_ptn == phantom_obj || n_ptn == null_obj)
381 return; // Skip predefined nodes.
382
383 int opcode = n->Opcode();
384 switch (opcode) {
385 case Op_AddP: {
386 Node* base = get_addp_base(n);
387 PointsToNode* ptn_base = ptnode_adr(base->_idx);
388 // Field nodes are created for all field types. They are used in
389 // adjust_scalar_replaceable_state() and split_unique_types().
390 // Note, non-oop fields will have only base edges in Connection
391 // Graph because such fields are not used for oop loads and stores.
392 int offset = address_offset(n, igvn);
393 add_field(n, PointsToNode::NoEscape, offset);
394 if (ptn_base == NULL) {
395 delayed_worklist->push(n); // Process it later.
396 } else {
397 n_ptn = ptnode_adr(n_idx);
398 add_base(n_ptn->as_Field(), ptn_base);
399 }
400 break;
401 }
402 case Op_CastX2P: {
403 map_ideal_node(n, phantom_obj);
404 break;
405 }
406 case Op_CastPP:
407 case Op_CheckCastPP:
408 case Op_EncodeP:
409 case Op_DecodeN:
410 case Op_EncodePKlass:
411 case Op_DecodeNKlass: {
412 add_local_var_and_edge(n, PointsToNode::NoEscape,
413 n->in(1), delayed_worklist);
414 break;
415 }
416 case Op_CMoveP: {
417 add_local_var(n, PointsToNode::NoEscape);
418 // Do not add edges during first iteration because some could be
419 // not defined yet.
420 delayed_worklist->push(n);
421 break;
422 }
423 case Op_ConP:
424 case Op_ConN:
425 case Op_ConNKlass: {
426 // assume all oop constants globally escape except for null
427 PointsToNode::EscapeState es;
428 const Type* t = igvn->type(n);
429 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
430 es = PointsToNode::NoEscape;
431 } else {
432 es = PointsToNode::GlobalEscape;
433 }
434 add_java_object(n, es);
435 break;
436 }
437 case Op_CreateEx: {
438 // assume that all exception objects globally escape
439 map_ideal_node(n, phantom_obj);
440 break;
441 }
442 case Op_LoadKlass:
443 case Op_LoadNKlass: {
444 // Unknown class is loaded
445 map_ideal_node(n, phantom_obj);
446 break;
447 }
448 case Op_LoadP:
449 case Op_LoadN:
450 case Op_LoadPLocked: {
451 add_objload_to_connection_graph(n, delayed_worklist);
452 break;
453 }
454 case Op_Parm: {
455 map_ideal_node(n, phantom_obj);
456 break;
457 }
458 case Op_PartialSubtypeCheck: {
459 // Produces Null or notNull and is used in only in CmpP so
460 // phantom_obj could be used.
461 map_ideal_node(n, phantom_obj); // Result is unknown
462 break;
463 }
464 case Op_Phi: {
465 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
466 // ThreadLocal has RawPtr type.
467 const Type* t = n->as_Phi()->type();
468 if (t->make_ptr() != NULL) {
469 add_local_var(n, PointsToNode::NoEscape);
470 // Do not add edges during first iteration because some could be
471 // not defined yet.
472 delayed_worklist->push(n);
473 }
474 break;
475 }
476 case Op_Proj: {
477 // we are only interested in the oop result projection from a call
478 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
479 n->in(0)->as_Call()->returns_pointer()) {
480 add_local_var_and_edge(n, PointsToNode::NoEscape,
481 n->in(0), delayed_worklist);
482 }
483 break;
484 }
485 case Op_Rethrow: // Exception object escapes
486 case Op_Return: {
487 if (n->req() > TypeFunc::Parms &&
488 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
489 // Treat Return value as LocalVar with GlobalEscape escape state.
490 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
491 n->in(TypeFunc::Parms), delayed_worklist);
492 }
493 break;
494 }
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_CompareAndSwapP:
505 case Op_CompareAndSwapN: {
506 Node* adr = n->in(MemNode::Address);
507 const Type *adr_type = igvn->type(adr);
508 adr_type = adr_type->make_ptr();
509 if (adr_type == NULL) {
510 break; // skip dead nodes
511 }
512 if (adr_type->isa_oopptr() ||
513 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
514 (adr_type == TypeRawPtr::NOTNULL &&
515 adr->in(AddPNode::Address)->is_Proj() &&
516 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
517 delayed_worklist->push(n); // Process it later.
518 #ifdef ASSERT
519 assert(adr->is_AddP(), "expecting an AddP");
520 if (adr_type == TypeRawPtr::NOTNULL) {
521 // Verify a raw address for a store captured by Initialize node.
522 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
523 assert(offs != Type::OffsetBot, "offset must be a constant");
524 }
525 #endif
526 } else {
527 // Ignore copy the displaced header to the BoxNode (OSR compilation).
528 if (adr->is_BoxLock())
529 break;
530 // Stored value escapes in unsafe access.
531 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
532 // Pointer stores in G1 barriers looks like unsafe access.
533 // Ignore such stores to be able scalar replace non-escaping
534 // allocations.
535 if ((UseG1GC || UseShenandoahGC) && adr->is_AddP()) {
536 Node* base = get_addp_base(adr);
537 if (base->Opcode() == Op_LoadP &&
538 base->in(MemNode::Address)->is_AddP()) {
539 adr = base->in(MemNode::Address);
540 Node* tls = get_addp_base(adr);
541 if (tls->Opcode() == Op_ThreadLocal) {
542 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
543 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
544 PtrQueue::byte_offset_of_buf())) {
545 break; // G1 pre barrier previous oop value store.
546 }
547 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
548 PtrQueue::byte_offset_of_buf())) {
549 break; // G1 post barrier card address store.
550 }
551 }
552 }
553 }
554 delayed_worklist->push(n); // Process unsafe access later.
555 break;
556 }
557 #ifdef ASSERT
558 n->dump(1);
559 assert(false, "not unsafe or G1 barrier raw StoreP");
560 #endif
561 }
562 break;
563 }
564 case Op_AryEq:
565 case Op_StrComp:
566 case Op_StrEquals:
567 case Op_StrIndexOf:
568 case Op_EncodeISOArray: {
569 add_local_var(n, PointsToNode::ArgEscape);
570 delayed_worklist->push(n); // Process it later.
571 break;
572 }
573 case Op_ThreadLocal: {
574 add_java_object(n, PointsToNode::ArgEscape);
575 break;
576 }
577 case Op_ShenandoahReadBarrier:
578 case Op_ShenandoahWriteBarrier:
579 // Barriers 'pass through' its arguments. I.e. what goes in, comes out.
580 // It doesn't escape.
581 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahBarrierNode::ValueIn), delayed_worklist);
582 break;
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_CompareAndSwapP:
706 case Op_CompareAndSwapN:
707 case Op_GetAndSetP:
708 case Op_GetAndSetN: {
709 Node* adr = n->in(MemNode::Address);
710 const Type *adr_type = _igvn->type(adr);
711 adr_type = adr_type->make_ptr();
712 #ifdef ASSERT
713 if (adr_type == NULL) {
714 n->dump(1);
715 assert(adr_type != NULL, "dead node should not be on list");
716 break;
717 }
718 #endif
719 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN) {
720 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
721 }
722 if (adr_type->isa_oopptr() ||
723 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
724 (adr_type == TypeRawPtr::NOTNULL &&
725 adr->in(AddPNode::Address)->is_Proj() &&
726 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
727 // Point Address to Value
728 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
729 assert(adr_ptn != NULL &&
730 adr_ptn->as_Field()->is_oop(), "node should be registered");
731 Node *val = n->in(MemNode::ValueIn);
732 PointsToNode* ptn = ptnode_adr(val->_idx);
733 assert(ptn != NULL, "node should be registered");
734 add_edge(adr_ptn, ptn);
735 break;
736 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
737 // Stored value escapes in unsafe access.
738 Node *val = n->in(MemNode::ValueIn);
739 PointsToNode* ptn = ptnode_adr(val->_idx);
740 assert(ptn != NULL, "node should be registered");
741 set_escape_state(ptn, PointsToNode::GlobalEscape);
742 // Add edge to object for unsafe access with offset.
743 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
744 assert(adr_ptn != NULL, "node should be registered");
745 if (adr_ptn->is_Field()) {
746 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
747 add_edge(adr_ptn, ptn);
748 }
749 break;
750 }
751 ELSE_FAIL("Op_StoreP");
752 }
753 case Op_AryEq:
754 case Op_StrComp:
755 case Op_StrEquals:
756 case Op_StrIndexOf:
757 case Op_EncodeISOArray: {
758 // char[] arrays passed to string intrinsic do not escape but
759 // they are not scalar replaceable. Adjust escape state for them.
760 // Start from in(2) edge since in(1) is memory edge.
761 for (uint i = 2; i < n->req(); i++) {
762 Node* adr = n->in(i);
763 const Type* at = _igvn->type(adr);
764 if (!adr->is_top() && at->isa_ptr()) {
765 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
766 at->isa_ptr() != NULL, "expecting a pointer");
767 if (adr->is_AddP()) {
768 adr = get_addp_base(adr);
769 }
770 PointsToNode* ptn = ptnode_adr(adr->_idx);
771 assert(ptn != NULL, "node should be registered");
772 add_edge(n_ptn, ptn);
773 }
774 }
775 break;
776 }
777 case Op_ShenandoahReadBarrier:
778 case Op_ShenandoahWriteBarrier:
779 // Barriers 'pass through' its arguments. I.e. what goes in, comes out.
780 // It doesn't escape.
781 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahBarrierNode::ValueIn), NULL);
782 break;
783 default: {
784 // This method should be called only for EA specific nodes which may
785 // miss some edges when they were created.
786 #ifdef ASSERT
787 n->dump(1);
788 #endif
789 guarantee(false, "unknown node");
790 }
791 }
792 return;
793 }
794
795 void ConnectionGraph::add_call_node(CallNode* call) {
796 assert(call->returns_pointer(), "only for call which returns pointer");
797 uint call_idx = call->_idx;
798 if (call->is_Allocate()) {
799 Node* k = call->in(AllocateNode::KlassNode);
800 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
801 assert(kt != NULL, "TypeKlassPtr required.");
802 ciKlass* cik = kt->klass();
803 PointsToNode::EscapeState es = PointsToNode::NoEscape;
804 bool scalar_replaceable = true;
805 if (call->is_AllocateArray()) {
806 if (!cik->is_array_klass()) { // StressReflectiveCode
807 es = PointsToNode::GlobalEscape;
808 } else {
809 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
810 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
811 // Not scalar replaceable if the length is not constant or too big.
812 scalar_replaceable = false;
813 }
814 }
815 } else { // Allocate instance
816 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
817 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
818 !cik->is_instance_klass() || // StressReflectiveCode
819 cik->as_instance_klass()->has_finalizer()) {
820 es = PointsToNode::GlobalEscape;
821 }
822 }
823 add_java_object(call, es);
824 PointsToNode* ptn = ptnode_adr(call_idx);
825 if (!scalar_replaceable && ptn->scalar_replaceable()) {
826 ptn->set_scalar_replaceable(false);
827 }
828 } else if (call->is_CallStaticJava()) {
829 // Call nodes could be different types:
830 //
831 // 1. CallDynamicJavaNode (what happened during call is unknown):
832 //
833 // - mapped to GlobalEscape JavaObject node if oop is returned;
834 //
835 // - all oop arguments are escaping globally;
836 //
837 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
838 //
839 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
840 //
841 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
842 // - mapped to NoEscape JavaObject node if non-escaping object allocated
843 // during call is returned;
844 // - mapped to ArgEscape LocalVar node pointed to object arguments
845 // which are returned and does not escape during call;
846 //
847 // - oop arguments escaping status is defined by bytecode analysis;
848 //
849 // For a static call, we know exactly what method is being called.
850 // Use bytecode estimator to record whether the call's return value escapes.
851 ciMethod* meth = call->as_CallJava()->method();
852 if (meth == NULL) {
853 const char* name = call->as_CallStaticJava()->_name;
854 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
855 // Returns a newly allocated unescaped object.
856 add_java_object(call, PointsToNode::NoEscape);
857 ptnode_adr(call_idx)->set_scalar_replaceable(false);
858 } else if (meth->is_boxing_method()) {
859 // Returns boxing object
860 PointsToNode::EscapeState es;
861 vmIntrinsics::ID intr = meth->intrinsic_id();
862 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
863 // It does not escape if object is always allocated.
864 es = PointsToNode::NoEscape;
865 } else {
866 // It escapes globally if object could be loaded from cache.
867 es = PointsToNode::GlobalEscape;
868 }
869 add_java_object(call, es);
870 } else {
871 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
872 call_analyzer->copy_dependencies(_compile->dependencies());
873 if (call_analyzer->is_return_allocated()) {
874 // Returns a newly allocated unescaped object, simply
875 // update dependency information.
876 // Mark it as NoEscape so that objects referenced by
877 // it's fields will be marked as NoEscape at least.
878 add_java_object(call, PointsToNode::NoEscape);
879 ptnode_adr(call_idx)->set_scalar_replaceable(false);
880 } else {
881 // Determine whether any arguments are returned.
882 const TypeTuple* d = call->tf()->domain();
883 bool ret_arg = false;
884 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
885 if (d->field_at(i)->isa_ptr() != NULL &&
886 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
887 ret_arg = true;
888 break;
889 }
890 }
891 if (ret_arg) {
892 add_local_var(call, PointsToNode::ArgEscape);
893 } else {
894 // Returns unknown object.
895 map_ideal_node(call, phantom_obj);
896 }
897 }
898 }
899 } else {
900 // An other type of call, assume the worst case:
901 // returned value is unknown and globally escapes.
902 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
903 map_ideal_node(call, phantom_obj);
904 }
905 }
906
907 void ConnectionGraph::process_call_arguments(CallNode *call) {
908 bool is_arraycopy = false;
909 switch (call->Opcode()) {
910 #ifdef ASSERT
911 case Op_Allocate:
912 case Op_AllocateArray:
913 case Op_Lock:
914 case Op_Unlock:
915 assert(false, "should be done already");
916 break;
917 #endif
918 case Op_ArrayCopy:
919 case Op_CallLeafNoFP:
920 // Most array copies are ArrayCopy nodes at this point but there
921 // are still a few direct calls to the copy subroutines (See
922 // PhaseStringOpts::copy_string())
923 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
924 call->as_CallLeaf()->is_call_to_arraycopystub();
925 // fall through
926 case Op_CallLeaf: {
927 // Stub calls, objects do not escape but they are not scale replaceable.
928 // Adjust escape state for outgoing arguments.
929 const TypeTuple * d = call->tf()->domain();
930 bool src_has_oops = false;
931 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
932 const Type* at = d->field_at(i);
933 Node *arg = call->in(i);
934 if (arg == NULL) {
935 continue;
936 }
937 const Type *aat = _igvn->type(arg);
938 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
939 continue;
940 if (arg->is_AddP()) {
941 //
942 // The inline_native_clone() case when the arraycopy stub is called
943 // after the allocation before Initialize and CheckCastPP nodes.
944 // Or normal arraycopy for object arrays case.
945 //
946 // Set AddP's base (Allocate) as not scalar replaceable since
947 // pointer to the base (with offset) is passed as argument.
948 //
949 arg = get_addp_base(arg);
950 }
951 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
952 assert(arg_ptn != NULL, "should be registered");
953 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
954 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
955 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
956 aat->isa_ptr() != NULL, "expecting an Ptr");
957 bool arg_has_oops = aat->isa_oopptr() &&
958 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
959 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
960 if (i == TypeFunc::Parms) {
961 src_has_oops = arg_has_oops;
962 }
963 //
964 // src or dst could be j.l.Object when other is basic type array:
965 //
966 // arraycopy(char[],0,Object*,0,size);
967 // arraycopy(Object*,0,char[],0,size);
968 //
969 // Don't add edges in such cases.
970 //
971 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
972 arg_has_oops && (i > TypeFunc::Parms);
973 #ifdef ASSERT
974 if (!(is_arraycopy ||
975 (call->as_CallLeaf()->_name != NULL &&
976 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
977 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
978 strcmp(call->as_CallLeaf()->_name, "shenandoah_clone_barrier") == 0 ||
979 strcmp(call->as_CallLeaf()->_name, "shenandoah_cas_obj") == 0 ||
980 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
981 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
982 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
983 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
984 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
985 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
986 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
993 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0)
999 ))) {
1000 call->dump();
1001 fatal(err_msg_res("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name));
1002 }
1003 #endif
1004 // Always process arraycopy's destination object since
1005 // we need to add all possible edges to references in
1006 // source object.
1007 if (arg_esc >= PointsToNode::ArgEscape &&
1008 !arg_is_arraycopy_dest) {
1009 continue;
1010 }
1011 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1012 if (call->is_ArrayCopy()) {
1013 ArrayCopyNode* ac = call->as_ArrayCopy();
1014 if (ac->is_clonebasic() ||
1015 ac->is_arraycopy_validated() ||
1016 ac->is_copyof_validated() ||
1017 ac->is_copyofrange_validated()) {
1018 es = PointsToNode::NoEscape;
1019 }
1020 }
1021 set_escape_state(arg_ptn, es);
1022 if (arg_is_arraycopy_dest) {
1023 Node* src = call->in(TypeFunc::Parms);
1024 if (src->is_AddP()) {
1025 src = get_addp_base(src);
1026 }
1027 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1028 assert(src_ptn != NULL, "should be registered");
1029 if (arg_ptn != src_ptn) {
1030 // Special arraycopy edge:
1031 // A destination object's field can't have the source object
1032 // as base since objects escape states are not related.
1033 // Only escape state of destination object's fields affects
1034 // escape state of fields in source object.
1035 add_arraycopy(call, es, src_ptn, arg_ptn);
1036 }
1037 }
1038 }
1039 }
1040 break;
1041 }
1042 case Op_CallStaticJava: {
1043 // For a static call, we know exactly what method is being called.
1044 // Use bytecode estimator to record the call's escape affects
1045 #ifdef ASSERT
1046 const char* name = call->as_CallStaticJava()->_name;
1047 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1048 #endif
1049 ciMethod* meth = call->as_CallJava()->method();
1050 if ((meth != NULL) && meth->is_boxing_method()) {
1051 break; // Boxing methods do not modify any oops.
1052 }
1053 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1054 // fall-through if not a Java method or no analyzer information
1055 if (call_analyzer != NULL) {
1056 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1057 const TypeTuple* d = call->tf()->domain();
1058 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1059 const Type* at = d->field_at(i);
1060 int k = i - TypeFunc::Parms;
1061 Node* arg = call->in(i);
1062 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1063 if (at->isa_ptr() != NULL &&
1064 call_analyzer->is_arg_returned(k)) {
1065 // The call returns arguments.
1066 if (call_ptn != NULL) { // Is call's result used?
1067 assert(call_ptn->is_LocalVar(), "node should be registered");
1068 assert(arg_ptn != NULL, "node should be registered");
1069 add_edge(call_ptn, arg_ptn);
1070 }
1071 }
1072 if (at->isa_oopptr() != NULL &&
1073 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1074 if (!call_analyzer->is_arg_stack(k)) {
1075 // The argument global escapes
1076 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1077 } else {
1078 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1079 if (!call_analyzer->is_arg_local(k)) {
1080 // The argument itself doesn't escape, but any fields might
1081 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1082 }
1083 }
1084 }
1085 }
1086 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1087 // The call returns arguments.
1088 assert(call_ptn->edge_count() > 0, "sanity");
1089 if (!call_analyzer->is_return_local()) {
1090 // Returns also unknown object.
1091 add_edge(call_ptn, phantom_obj);
1092 }
1093 }
1094 break;
1095 }
1096 }
1097 default: {
1098 // Fall-through here if not a Java method or no analyzer information
1099 // or some other type of call, assume the worst case: all arguments
1100 // globally escape.
1101 const TypeTuple* d = call->tf()->domain();
1102 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1103 const Type* at = d->field_at(i);
1104 if (at->isa_oopptr() != NULL) {
1105 Node* arg = call->in(i);
1106 if (arg->is_AddP()) {
1107 arg = get_addp_base(arg);
1108 }
1109 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1110 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1111 }
1112 }
1113 }
1114 }
1115 }
1116
1117
1118 // Finish Graph construction.
1119 bool ConnectionGraph::complete_connection_graph(
1120 GrowableArray<PointsToNode*>& ptnodes_worklist,
1121 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1122 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1123 GrowableArray<FieldNode*>& oop_fields_worklist) {
1124 // Normally only 1-3 passes needed to build Connection Graph depending
1125 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1126 // Set limit to 20 to catch situation when something did go wrong and
1127 // bailout Escape Analysis.
1128 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1129 #define CG_BUILD_ITER_LIMIT 20
1130
1131 // Propagate GlobalEscape and ArgEscape escape states and check that
1132 // we still have non-escaping objects. The method pushs on _worklist
1133 // Field nodes which reference phantom_object.
1134 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1135 return false; // Nothing to do.
1136 }
1137 // Now propagate references to all JavaObject nodes.
1138 int java_objects_length = java_objects_worklist.length();
1139 elapsedTimer time;
1140 bool timeout = false;
1141 int new_edges = 1;
1142 int iterations = 0;
1143 do {
1144 while ((new_edges > 0) &&
1145 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1146 double start_time = time.seconds();
1147 time.start();
1148 new_edges = 0;
1149 // Propagate references to phantom_object for nodes pushed on _worklist
1150 // by find_non_escaped_objects() and find_field_value().
1151 new_edges += add_java_object_edges(phantom_obj, false);
1152 for (int next = 0; next < java_objects_length; ++next) {
1153 JavaObjectNode* ptn = java_objects_worklist.at(next);
1154 new_edges += add_java_object_edges(ptn, true);
1155
1156 #define SAMPLE_SIZE 4
1157 if ((next % SAMPLE_SIZE) == 0) {
1158 // Each 4 iterations calculate how much time it will take
1159 // to complete graph construction.
1160 time.stop();
1161 // Poll for requests from shutdown mechanism to quiesce compiler
1162 // because Connection graph construction may take long time.
1163 CompileBroker::maybe_block();
1164 double stop_time = time.seconds();
1165 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1166 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1167 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1168 timeout = true;
1169 break; // Timeout
1170 }
1171 start_time = stop_time;
1172 time.start();
1173 }
1174 #undef SAMPLE_SIZE
1175
1176 }
1177 if (timeout) break;
1178 if (new_edges > 0) {
1179 // Update escape states on each iteration if graph was updated.
1180 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1181 return false; // Nothing to do.
1182 }
1183 }
1184 time.stop();
1185 if (time.seconds() >= EscapeAnalysisTimeout) {
1186 timeout = true;
1187 break;
1188 }
1189 }
1190 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1191 time.start();
1192 // Find fields which have unknown value.
1193 int fields_length = oop_fields_worklist.length();
1194 for (int next = 0; next < fields_length; next++) {
1195 FieldNode* field = oop_fields_worklist.at(next);
1196 if (field->edge_count() == 0) {
1197 new_edges += find_field_value(field);
1198 // This code may added new edges to phantom_object.
1199 // Need an other cycle to propagate references to phantom_object.
1200 }
1201 }
1202 time.stop();
1203 if (time.seconds() >= EscapeAnalysisTimeout) {
1204 timeout = true;
1205 break;
1206 }
1207 } else {
1208 new_edges = 0; // Bailout
1209 }
1210 } while (new_edges > 0);
1211
1212 // Bailout if passed limits.
1213 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1214 Compile* C = _compile;
1215 if (C->log() != NULL) {
1216 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1217 C->log()->text("%s", timeout ? "time" : "iterations");
1218 C->log()->end_elem(" limit'");
1219 }
1220 assert(ExitEscapeAnalysisOnTimeout, err_msg_res("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1221 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length()));
1222 // Possible infinite build_connection_graph loop,
1223 // bailout (no changes to ideal graph were made).
1224 return false;
1225 }
1226 #ifdef ASSERT
1227 if (Verbose && PrintEscapeAnalysis) {
1228 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1229 iterations, nodes_size(), ptnodes_worklist.length());
1230 }
1231 #endif
1232
1233 #undef CG_BUILD_ITER_LIMIT
1234
1235 // Find fields initialized by NULL for non-escaping Allocations.
1236 int non_escaped_length = non_escaped_worklist.length();
1237 for (int next = 0; next < non_escaped_length; next++) {
1238 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1239 PointsToNode::EscapeState es = ptn->escape_state();
1240 assert(es <= PointsToNode::ArgEscape, "sanity");
1241 if (es == PointsToNode::NoEscape) {
1242 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1243 // Adding references to NULL object does not change escape states
1244 // since it does not escape. Also no fields are added to NULL object.
1245 add_java_object_edges(null_obj, false);
1246 }
1247 }
1248 Node* n = ptn->ideal_node();
1249 if (n->is_Allocate()) {
1250 // The object allocated by this Allocate node will never be
1251 // seen by an other thread. Mark it so that when it is
1252 // expanded no MemBarStoreStore is added.
1253 InitializeNode* ini = n->as_Allocate()->initialization();
1254 if (ini != NULL)
1255 ini->set_does_not_escape();
1256 }
1257 }
1258 return true; // Finished graph construction.
1259 }
1260
1261 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1262 // and check that we still have non-escaping java objects.
1263 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1264 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1265 GrowableArray<PointsToNode*> escape_worklist;
1266 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1267 int ptnodes_length = ptnodes_worklist.length();
1268 for (int next = 0; next < ptnodes_length; ++next) {
1269 PointsToNode* ptn = ptnodes_worklist.at(next);
1270 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1271 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1272 escape_worklist.push(ptn);
1273 }
1274 }
1275 // Set escape states to referenced nodes (edges list).
1276 while (escape_worklist.length() > 0) {
1277 PointsToNode* ptn = escape_worklist.pop();
1278 PointsToNode::EscapeState es = ptn->escape_state();
1279 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1280 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1281 es >= PointsToNode::ArgEscape) {
1282 // GlobalEscape or ArgEscape state of field means it has unknown value.
1283 if (add_edge(ptn, phantom_obj)) {
1284 // New edge was added
1285 add_field_uses_to_worklist(ptn->as_Field());
1286 }
1287 }
1288 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1289 PointsToNode* e = i.get();
1290 if (e->is_Arraycopy()) {
1291 assert(ptn->arraycopy_dst(), "sanity");
1292 // Propagate only fields escape state through arraycopy edge.
1293 if (e->fields_escape_state() < field_es) {
1294 set_fields_escape_state(e, field_es);
1295 escape_worklist.push(e);
1296 }
1297 } else if (es >= field_es) {
1298 // fields_escape_state is also set to 'es' if it is less than 'es'.
1299 if (e->escape_state() < es) {
1300 set_escape_state(e, es);
1301 escape_worklist.push(e);
1302 }
1303 } else {
1304 // Propagate field escape state.
1305 bool es_changed = false;
1306 if (e->fields_escape_state() < field_es) {
1307 set_fields_escape_state(e, field_es);
1308 es_changed = true;
1309 }
1310 if ((e->escape_state() < field_es) &&
1311 e->is_Field() && ptn->is_JavaObject() &&
1312 e->as_Field()->is_oop()) {
1313 // Change escape state of referenced fields.
1314 set_escape_state(e, field_es);
1315 es_changed = true;
1316 } else if (e->escape_state() < es) {
1317 set_escape_state(e, es);
1318 es_changed = true;
1319 }
1320 if (es_changed) {
1321 escape_worklist.push(e);
1322 }
1323 }
1324 }
1325 }
1326 // Remove escaped objects from non_escaped list.
1327 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1328 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1329 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1330 non_escaped_worklist.delete_at(next);
1331 }
1332 if (ptn->escape_state() == PointsToNode::NoEscape) {
1333 // Find fields in non-escaped allocations which have unknown value.
1334 find_init_values(ptn, phantom_obj, NULL);
1335 }
1336 }
1337 return (non_escaped_worklist.length() > 0);
1338 }
1339
1340 // Add all references to JavaObject node by walking over all uses.
1341 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1342 int new_edges = 0;
1343 if (populate_worklist) {
1344 // Populate _worklist by uses of jobj's uses.
1345 for (UseIterator i(jobj); i.has_next(); i.next()) {
1346 PointsToNode* use = i.get();
1347 if (use->is_Arraycopy())
1348 continue;
1349 add_uses_to_worklist(use);
1350 if (use->is_Field() && use->as_Field()->is_oop()) {
1351 // Put on worklist all field's uses (loads) and
1352 // related field nodes (same base and offset).
1353 add_field_uses_to_worklist(use->as_Field());
1354 }
1355 }
1356 }
1357 for (int l = 0; l < _worklist.length(); l++) {
1358 PointsToNode* use = _worklist.at(l);
1359 if (PointsToNode::is_base_use(use)) {
1360 // Add reference from jobj to field and from field to jobj (field's base).
1361 use = PointsToNode::get_use_node(use)->as_Field();
1362 if (add_base(use->as_Field(), jobj)) {
1363 new_edges++;
1364 }
1365 continue;
1366 }
1367 assert(!use->is_JavaObject(), "sanity");
1368 if (use->is_Arraycopy()) {
1369 if (jobj == null_obj) // NULL object does not have field edges
1370 continue;
1371 // Added edge from Arraycopy node to arraycopy's source java object
1372 if (add_edge(use, jobj)) {
1373 jobj->set_arraycopy_src();
1374 new_edges++;
1375 }
1376 // and stop here.
1377 continue;
1378 }
1379 if (!add_edge(use, jobj))
1380 continue; // No new edge added, there was such edge already.
1381 new_edges++;
1382 if (use->is_LocalVar()) {
1383 add_uses_to_worklist(use);
1384 if (use->arraycopy_dst()) {
1385 for (EdgeIterator i(use); i.has_next(); i.next()) {
1386 PointsToNode* e = i.get();
1387 if (e->is_Arraycopy()) {
1388 if (jobj == null_obj) // NULL object does not have field edges
1389 continue;
1390 // Add edge from arraycopy's destination java object to Arraycopy node.
1391 if (add_edge(jobj, e)) {
1392 new_edges++;
1393 jobj->set_arraycopy_dst();
1394 }
1395 }
1396 }
1397 }
1398 } else {
1399 // Added new edge to stored in field values.
1400 // Put on worklist all field's uses (loads) and
1401 // related field nodes (same base and offset).
1402 add_field_uses_to_worklist(use->as_Field());
1403 }
1404 }
1405 _worklist.clear();
1406 _in_worklist.Reset();
1407 return new_edges;
1408 }
1409
1410 // Put on worklist all related field nodes.
1411 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1412 assert(field->is_oop(), "sanity");
1413 int offset = field->offset();
1414 add_uses_to_worklist(field);
1415 // Loop over all bases of this field and push on worklist Field nodes
1416 // with the same offset and base (since they may reference the same field).
1417 for (BaseIterator i(field); i.has_next(); i.next()) {
1418 PointsToNode* base = i.get();
1419 add_fields_to_worklist(field, base);
1420 // Check if the base was source object of arraycopy and go over arraycopy's
1421 // destination objects since values stored to a field of source object are
1422 // accessable by uses (loads) of fields of destination objects.
1423 if (base->arraycopy_src()) {
1424 for (UseIterator j(base); j.has_next(); j.next()) {
1425 PointsToNode* arycp = j.get();
1426 if (arycp->is_Arraycopy()) {
1427 for (UseIterator k(arycp); k.has_next(); k.next()) {
1428 PointsToNode* abase = k.get();
1429 if (abase->arraycopy_dst() && abase != base) {
1430 // Look for the same arraycopy reference.
1431 add_fields_to_worklist(field, abase);
1432 }
1433 }
1434 }
1435 }
1436 }
1437 }
1438 }
1439
1440 // Put on worklist all related field nodes.
1441 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1442 int offset = field->offset();
1443 if (base->is_LocalVar()) {
1444 for (UseIterator j(base); j.has_next(); j.next()) {
1445 PointsToNode* f = j.get();
1446 if (PointsToNode::is_base_use(f)) { // Field
1447 f = PointsToNode::get_use_node(f);
1448 if (f == field || !f->as_Field()->is_oop())
1449 continue;
1450 int offs = f->as_Field()->offset();
1451 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1452 add_to_worklist(f);
1453 }
1454 }
1455 }
1456 } else {
1457 assert(base->is_JavaObject(), "sanity");
1458 if (// Skip phantom_object since it is only used to indicate that
1459 // this field's content globally escapes.
1460 (base != phantom_obj) &&
1461 // NULL object node does not have fields.
1462 (base != null_obj)) {
1463 for (EdgeIterator i(base); i.has_next(); i.next()) {
1464 PointsToNode* f = i.get();
1465 // Skip arraycopy edge since store to destination object field
1466 // does not update value in source object field.
1467 if (f->is_Arraycopy()) {
1468 assert(base->arraycopy_dst(), "sanity");
1469 continue;
1470 }
1471 if (f == field || !f->as_Field()->is_oop())
1472 continue;
1473 int offs = f->as_Field()->offset();
1474 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1475 add_to_worklist(f);
1476 }
1477 }
1478 }
1479 }
1480 }
1481
1482 // Find fields which have unknown value.
1483 int ConnectionGraph::find_field_value(FieldNode* field) {
1484 // Escaped fields should have init value already.
1485 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1486 int new_edges = 0;
1487 for (BaseIterator i(field); i.has_next(); i.next()) {
1488 PointsToNode* base = i.get();
1489 if (base->is_JavaObject()) {
1490 // Skip Allocate's fields which will be processed later.
1491 if (base->ideal_node()->is_Allocate())
1492 return 0;
1493 assert(base == null_obj, "only NULL ptr base expected here");
1494 }
1495 }
1496 if (add_edge(field, phantom_obj)) {
1497 // New edge was added
1498 new_edges++;
1499 add_field_uses_to_worklist(field);
1500 }
1501 return new_edges;
1502 }
1503
1504 // Find fields initializing values for allocations.
1505 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1506 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1507 int new_edges = 0;
1508 Node* alloc = pta->ideal_node();
1509 if (init_val == phantom_obj) {
1510 // Do nothing for Allocate nodes since its fields values are
1511 // "known" unless they are initialized by arraycopy/clone.
1512 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1513 return 0;
1514 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1515 #ifdef ASSERT
1516 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1517 const char* name = alloc->as_CallStaticJava()->_name;
1518 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1519 }
1520 #endif
1521 // Non-escaped allocation returned from Java or runtime call have
1522 // unknown values in fields.
1523 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1524 PointsToNode* field = i.get();
1525 if (field->is_Field() && field->as_Field()->is_oop()) {
1526 if (add_edge(field, phantom_obj)) {
1527 // New edge was added
1528 new_edges++;
1529 add_field_uses_to_worklist(field->as_Field());
1530 }
1531 }
1532 }
1533 return new_edges;
1534 }
1535 assert(init_val == null_obj, "sanity");
1536 // Do nothing for Call nodes since its fields values are unknown.
1537 if (!alloc->is_Allocate())
1538 return 0;
1539
1540 InitializeNode* ini = alloc->as_Allocate()->initialization();
1541 bool visited_bottom_offset = false;
1542 GrowableArray<int> offsets_worklist;
1543
1544 // Check if an oop field's initializing value is recorded and add
1545 // a corresponding NULL if field's value if it is not recorded.
1546 // Connection Graph does not record a default initialization by NULL
1547 // captured by Initialize node.
1548 //
1549 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1550 PointsToNode* field = i.get(); // Field (AddP)
1551 if (!field->is_Field() || !field->as_Field()->is_oop())
1552 continue; // Not oop field
1553 int offset = field->as_Field()->offset();
1554 if (offset == Type::OffsetBot) {
1555 if (!visited_bottom_offset) {
1556 // OffsetBot is used to reference array's element,
1557 // always add reference to NULL to all Field nodes since we don't
1558 // known which element is referenced.
1559 if (add_edge(field, null_obj)) {
1560 // New edge was added
1561 new_edges++;
1562 add_field_uses_to_worklist(field->as_Field());
1563 visited_bottom_offset = true;
1564 }
1565 }
1566 } else {
1567 // Check only oop fields.
1568 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1569 if (adr_type->isa_rawptr()) {
1570 #ifdef ASSERT
1571 // Raw pointers are used for initializing stores so skip it
1572 // since it should be recorded already
1573 Node* base = get_addp_base(field->ideal_node());
1574 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1575 (base->in(0) == alloc),"unexpected pointer type");
1576 #endif
1577 continue;
1578 }
1579 if (!offsets_worklist.contains(offset)) {
1580 offsets_worklist.append(offset);
1581 Node* value = NULL;
1582 if (ini != NULL) {
1583 // StoreP::memory_type() == T_ADDRESS
1584 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1585 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1586 // Make sure initializing store has the same type as this AddP.
1587 // This AddP may reference non existing field because it is on a
1588 // dead branch of bimorphic call which is not eliminated yet.
1589 if (store != NULL && store->is_Store() &&
1590 store->as_Store()->memory_type() == ft) {
1591 value = store->in(MemNode::ValueIn);
1592 #ifdef ASSERT
1593 if (VerifyConnectionGraph) {
1594 // Verify that AddP already points to all objects the value points to.
1595 PointsToNode* val = ptnode_adr(value->_idx);
1596 assert((val != NULL), "should be processed already");
1597 PointsToNode* missed_obj = NULL;
1598 if (val->is_JavaObject()) {
1599 if (!field->points_to(val->as_JavaObject())) {
1600 missed_obj = val;
1601 }
1602 } else {
1603 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1604 tty->print_cr("----------init store has invalid value -----");
1605 store->dump();
1606 val->dump();
1607 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1608 }
1609 for (EdgeIterator j(val); j.has_next(); j.next()) {
1610 PointsToNode* obj = j.get();
1611 if (obj->is_JavaObject()) {
1612 if (!field->points_to(obj->as_JavaObject())) {
1613 missed_obj = obj;
1614 break;
1615 }
1616 }
1617 }
1618 }
1619 if (missed_obj != NULL) {
1620 tty->print_cr("----------field---------------------------------");
1621 field->dump();
1622 tty->print_cr("----------missed referernce to object-----------");
1623 missed_obj->dump();
1624 tty->print_cr("----------object referernced by init store -----");
1625 store->dump();
1626 val->dump();
1627 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1628 }
1629 }
1630 #endif
1631 } else {
1632 // There could be initializing stores which follow allocation.
1633 // For example, a volatile field store is not collected
1634 // by Initialize node.
1635 //
1636 // Need to check for dependent loads to separate such stores from
1637 // stores which follow loads. For now, add initial value NULL so
1638 // that compare pointers optimization works correctly.
1639 }
1640 }
1641 if (value == NULL) {
1642 // A field's initializing value was not recorded. Add NULL.
1643 if (add_edge(field, null_obj)) {
1644 // New edge was added
1645 new_edges++;
1646 add_field_uses_to_worklist(field->as_Field());
1647 }
1648 }
1649 }
1650 }
1651 }
1652 return new_edges;
1653 }
1654
1655 // Adjust scalar_replaceable state after Connection Graph is built.
1656 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1657 // Search for non-escaping objects which are not scalar replaceable
1658 // and mark them to propagate the state to referenced objects.
1659
1660 // 1. An object is not scalar replaceable if the field into which it is
1661 // stored has unknown offset (stored into unknown element of an array).
1662 //
1663 for (UseIterator i(jobj); i.has_next(); i.next()) {
1664 PointsToNode* use = i.get();
1665 if (use->is_Arraycopy()) {
1666 continue;
1667 }
1668 if (use->is_Field()) {
1669 FieldNode* field = use->as_Field();
1670 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1671 if (field->offset() == Type::OffsetBot) {
1672 jobj->set_scalar_replaceable(false);
1673 return;
1674 }
1675 // 2. An object is not scalar replaceable if the field into which it is
1676 // stored has multiple bases one of which is null.
1677 if (field->base_count() > 1) {
1678 for (BaseIterator i(field); i.has_next(); i.next()) {
1679 PointsToNode* base = i.get();
1680 if (base == null_obj) {
1681 jobj->set_scalar_replaceable(false);
1682 return;
1683 }
1684 }
1685 }
1686 }
1687 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1688 // 3. An object is not scalar replaceable if it is merged with other objects.
1689 for (EdgeIterator j(use); j.has_next(); j.next()) {
1690 PointsToNode* ptn = j.get();
1691 if (ptn->is_JavaObject() && ptn != jobj) {
1692 // Mark all objects.
1693 jobj->set_scalar_replaceable(false);
1694 ptn->set_scalar_replaceable(false);
1695 }
1696 }
1697 if (!jobj->scalar_replaceable()) {
1698 return;
1699 }
1700 }
1701
1702 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1703 if (j.get()->is_Arraycopy()) {
1704 continue;
1705 }
1706
1707 // Non-escaping object node should point only to field nodes.
1708 FieldNode* field = j.get()->as_Field();
1709 int offset = field->as_Field()->offset();
1710
1711 // 4. An object is not scalar replaceable if it has a field with unknown
1712 // offset (array's element is accessed in loop).
1713 if (offset == Type::OffsetBot) {
1714 jobj->set_scalar_replaceable(false);
1715 return;
1716 }
1717 // 5. Currently an object is not scalar replaceable if a LoadStore node
1718 // access its field since the field value is unknown after it.
1719 //
1720 Node* n = field->ideal_node();
1721 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1722 if (n->fast_out(i)->is_LoadStore()) {
1723 jobj->set_scalar_replaceable(false);
1724 return;
1725 }
1726 }
1727
1728 // 6. Or the address may point to more then one object. This may produce
1729 // the false positive result (set not scalar replaceable)
1730 // since the flow-insensitive escape analysis can't separate
1731 // the case when stores overwrite the field's value from the case
1732 // when stores happened on different control branches.
1733 //
1734 // Note: it will disable scalar replacement in some cases:
1735 //
1736 // Point p[] = new Point[1];
1737 // p[0] = new Point(); // Will be not scalar replaced
1738 //
1739 // but it will save us from incorrect optimizations in next cases:
1740 //
1741 // Point p[] = new Point[1];
1742 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1743 //
1744 if (field->base_count() > 1) {
1745 for (BaseIterator i(field); i.has_next(); i.next()) {
1746 PointsToNode* base = i.get();
1747 // Don't take into account LocalVar nodes which
1748 // may point to only one object which should be also
1749 // this field's base by now.
1750 if (base->is_JavaObject() && base != jobj) {
1751 // Mark all bases.
1752 jobj->set_scalar_replaceable(false);
1753 base->set_scalar_replaceable(false);
1754 }
1755 }
1756 }
1757 }
1758 }
1759
1760 #ifdef ASSERT
1761 void ConnectionGraph::verify_connection_graph(
1762 GrowableArray<PointsToNode*>& ptnodes_worklist,
1763 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1764 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1765 GrowableArray<Node*>& addp_worklist) {
1766 // Verify that graph is complete - no new edges could be added.
1767 int java_objects_length = java_objects_worklist.length();
1768 int non_escaped_length = non_escaped_worklist.length();
1769 int new_edges = 0;
1770 for (int next = 0; next < java_objects_length; ++next) {
1771 JavaObjectNode* ptn = java_objects_worklist.at(next);
1772 new_edges += add_java_object_edges(ptn, true);
1773 }
1774 assert(new_edges == 0, "graph was not complete");
1775 // Verify that escape state is final.
1776 int length = non_escaped_worklist.length();
1777 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1778 assert((non_escaped_length == non_escaped_worklist.length()) &&
1779 (non_escaped_length == length) &&
1780 (_worklist.length() == 0), "escape state was not final");
1781
1782 // Verify fields information.
1783 int addp_length = addp_worklist.length();
1784 for (int next = 0; next < addp_length; ++next ) {
1785 Node* n = addp_worklist.at(next);
1786 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1787 if (field->is_oop()) {
1788 // Verify that field has all bases
1789 Node* base = get_addp_base(n);
1790 PointsToNode* ptn = ptnode_adr(base->_idx);
1791 if (ptn->is_JavaObject()) {
1792 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1793 } else {
1794 assert(ptn->is_LocalVar(), "sanity");
1795 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1796 PointsToNode* e = i.get();
1797 if (e->is_JavaObject()) {
1798 assert(field->has_base(e->as_JavaObject()), "sanity");
1799 }
1800 }
1801 }
1802 // Verify that all fields have initializing values.
1803 if (field->edge_count() == 0) {
1804 tty->print_cr("----------field does not have references----------");
1805 field->dump();
1806 for (BaseIterator i(field); i.has_next(); i.next()) {
1807 PointsToNode* base = i.get();
1808 tty->print_cr("----------field has next base---------------------");
1809 base->dump();
1810 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1811 tty->print_cr("----------base has fields-------------------------");
1812 for (EdgeIterator j(base); j.has_next(); j.next()) {
1813 j.get()->dump();
1814 }
1815 tty->print_cr("----------base has references---------------------");
1816 for (UseIterator j(base); j.has_next(); j.next()) {
1817 j.get()->dump();
1818 }
1819 }
1820 }
1821 for (UseIterator i(field); i.has_next(); i.next()) {
1822 i.get()->dump();
1823 }
1824 assert(field->edge_count() > 0, "sanity");
1825 }
1826 }
1827 }
1828 }
1829 #endif
1830
1831 // Optimize ideal graph.
1832 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1833 GrowableArray<Node*>& storestore_worklist) {
1834 Compile* C = _compile;
1835 PhaseIterGVN* igvn = _igvn;
1836 if (EliminateLocks) {
1837 // Mark locks before changing ideal graph.
1838 int cnt = C->macro_count();
1839 for( int i=0; i < cnt; i++ ) {
1840 Node *n = C->macro_node(i);
1841 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1842 AbstractLockNode* alock = n->as_AbstractLock();
1843 if (!alock->is_non_esc_obj()) {
1844 if (not_global_escape(alock->obj_node())) {
1845 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1846 // The lock could be marked eliminated by lock coarsening
1847 // code during first IGVN before EA. Replace coarsened flag
1848 // to eliminate all associated locks/unlocks.
1849 #ifdef ASSERT
1850 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1851 #endif
1852 alock->set_non_esc_obj();
1853 }
1854 }
1855 }
1856 }
1857 }
1858
1859 if (OptimizePtrCompare) {
1860 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1861 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1862 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1863 // Optimize objects compare.
1864 while (ptr_cmp_worklist.length() != 0) {
1865 Node *n = ptr_cmp_worklist.pop();
1866 Node *res = optimize_ptr_compare(n);
1867 if (res != NULL) {
1868 #ifndef PRODUCT
1869 if (PrintOptimizePtrCompare) {
1870 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"));
1871 if (Verbose) {
1872 n->dump(1);
1873 }
1874 }
1875 #endif
1876 igvn->replace_node(n, res);
1877 }
1878 }
1879 // cleanup
1880 if (_pcmp_neq->outcnt() == 0)
1881 igvn->hash_delete(_pcmp_neq);
1882 if (_pcmp_eq->outcnt() == 0)
1883 igvn->hash_delete(_pcmp_eq);
1884 }
1885
1886 // For MemBarStoreStore nodes added in library_call.cpp, check
1887 // escape status of associated AllocateNode and optimize out
1888 // MemBarStoreStore node if the allocated object never escapes.
1889 while (storestore_worklist.length() != 0) {
1890 Node *n = storestore_worklist.pop();
1891 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1892 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1893 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1894 if (not_global_escape(alloc)) {
1895 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1896 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1897 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1898 igvn->register_new_node_with_optimizer(mb);
1899 igvn->replace_node(storestore, mb);
1900 }
1901 }
1902 }
1903
1904 // Optimize objects compare.
1905 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1906 assert(OptimizePtrCompare, "sanity");
1907 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1908 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1909 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1910 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1911 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1912 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1913
1914 // Check simple cases first.
1915 if (jobj1 != NULL) {
1916 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1917 if (jobj1 == jobj2) {
1918 // Comparing the same not escaping object.
1919 return _pcmp_eq;
1920 }
1921 Node* obj = jobj1->ideal_node();
1922 // Comparing not escaping allocation.
1923 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1924 !ptn2->points_to(jobj1)) {
1925 return _pcmp_neq; // This includes nullness check.
1926 }
1927 }
1928 }
1929 if (jobj2 != NULL) {
1930 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1931 Node* obj = jobj2->ideal_node();
1932 // Comparing not escaping allocation.
1933 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1934 !ptn1->points_to(jobj2)) {
1935 return _pcmp_neq; // This includes nullness check.
1936 }
1937 }
1938 }
1939 if (jobj1 != NULL && jobj1 != phantom_obj &&
1940 jobj2 != NULL && jobj2 != phantom_obj &&
1941 jobj1->ideal_node()->is_Con() &&
1942 jobj2->ideal_node()->is_Con()) {
1943 // Klass or String constants compare. Need to be careful with
1944 // compressed pointers - compare types of ConN and ConP instead of nodes.
1945 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1946 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1947 if (t1->make_ptr() == t2->make_ptr()) {
1948 return _pcmp_eq;
1949 } else {
1950 return _pcmp_neq;
1951 }
1952 }
1953 if (ptn1->meet(ptn2)) {
1954 return NULL; // Sets are not disjoint
1955 }
1956
1957 // Sets are disjoint.
1958 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1959 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1960 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1961 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1962 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1963 set2_has_unknown_ptr && set1_has_null_ptr) {
1964 // Check nullness of unknown object.
1965 return NULL;
1966 }
1967
1968 // Disjointness by itself is not sufficient since
1969 // alias analysis is not complete for escaped objects.
1970 // Disjoint sets are definitely unrelated only when
1971 // at least one set has only not escaping allocations.
1972 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1973 if (ptn1->non_escaping_allocation()) {
1974 return _pcmp_neq;
1975 }
1976 }
1977 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1978 if (ptn2->non_escaping_allocation()) {
1979 return _pcmp_neq;
1980 }
1981 }
1982 return NULL;
1983 }
1984
1985 // Connection Graph constuction functions.
1986
1987 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
1988 PointsToNode* ptadr = _nodes.at(n->_idx);
1989 if (ptadr != NULL) {
1990 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
1991 return;
1992 }
1993 Compile* C = _compile;
1994 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
1995 _nodes.at_put(n->_idx, ptadr);
1996 }
1997
1998 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
1999 PointsToNode* ptadr = _nodes.at(n->_idx);
2000 if (ptadr != NULL) {
2001 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2002 return;
2003 }
2004 Compile* C = _compile;
2005 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2006 _nodes.at_put(n->_idx, ptadr);
2007 }
2008
2009 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2010 PointsToNode* ptadr = _nodes.at(n->_idx);
2011 if (ptadr != NULL) {
2012 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2013 return;
2014 }
2015 bool unsafe = false;
2016 bool is_oop = is_oop_field(n, offset, &unsafe);
2017 if (unsafe) {
2018 es = PointsToNode::GlobalEscape;
2019 }
2020 Compile* C = _compile;
2021 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2022 _nodes.at_put(n->_idx, field);
2023 }
2024
2025 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2026 PointsToNode* src, PointsToNode* dst) {
2027 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2028 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2029 PointsToNode* ptadr = _nodes.at(n->_idx);
2030 if (ptadr != NULL) {
2031 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2032 return;
2033 }
2034 Compile* C = _compile;
2035 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2036 _nodes.at_put(n->_idx, ptadr);
2037 // Add edge from arraycopy node to source object.
2038 (void)add_edge(ptadr, src);
2039 src->set_arraycopy_src();
2040 // Add edge from destination object to arraycopy node.
2041 (void)add_edge(dst, ptadr);
2042 dst->set_arraycopy_dst();
2043 }
2044
2045 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2046 const Type* adr_type = n->as_AddP()->bottom_type();
2047 BasicType bt = T_INT;
2048 if (offset == Type::OffsetBot) {
2049 // Check only oop fields.
2050 if (!adr_type->isa_aryptr() ||
2051 (adr_type->isa_aryptr()->klass() == NULL) ||
2052 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2053 // OffsetBot is used to reference array's element. Ignore first AddP.
2054 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2055 bt = T_OBJECT;
2056 }
2057 }
2058 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2059 if (adr_type->isa_instptr()) {
2060 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2061 if (field != NULL) {
2062 bt = field->layout_type();
2063 } else {
2064 // Check for unsafe oop field access
2065 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2066 bt = T_OBJECT;
2067 (*unsafe) = true;
2068 }
2069 }
2070 } else if (adr_type->isa_aryptr()) {
2071 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2072 // Ignore array length load.
2073 } else if (UseShenandoahGC && offset == BrooksPointer::BYTE_OFFSET) {
2074 // Shenandoah read barrier.
2075 bt = T_ARRAY;
2076 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2077 // Ignore first AddP.
2078 } else {
2079 const Type* elemtype = adr_type->isa_aryptr()->elem();
2080 bt = elemtype->array_element_basic_type();
2081 }
2082 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2083 // Allocation initialization, ThreadLocal field access, unsafe access
2084 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN)) {
2085 bt = T_OBJECT;
2086 }
2087 }
2088 }
2089 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2090 }
2091
2092 // Returns unique pointed java object or NULL.
2093 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2094 assert(!_collecting, "should not call when contructed graph");
2095 // If the node was created after the escape computation we can't answer.
2096 uint idx = n->_idx;
2097 if (idx >= nodes_size()) {
2098 return NULL;
2099 }
2100 PointsToNode* ptn = ptnode_adr(idx);
2101 if (ptn->is_JavaObject()) {
2102 return ptn->as_JavaObject();
2103 }
2104 assert(ptn->is_LocalVar(), "sanity");
2105 // Check all java objects it points to.
2106 JavaObjectNode* jobj = NULL;
2107 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2108 PointsToNode* e = i.get();
2109 if (e->is_JavaObject()) {
2110 if (jobj == NULL) {
2111 jobj = e->as_JavaObject();
2112 } else if (jobj != e) {
2113 return NULL;
2114 }
2115 }
2116 }
2117 return jobj;
2118 }
2119
2120 // Return true if this node points only to non-escaping allocations.
2121 bool PointsToNode::non_escaping_allocation() {
2122 if (is_JavaObject()) {
2123 Node* n = ideal_node();
2124 if (n->is_Allocate() || n->is_CallStaticJava()) {
2125 return (escape_state() == PointsToNode::NoEscape);
2126 } else {
2127 return false;
2128 }
2129 }
2130 assert(is_LocalVar(), "sanity");
2131 // Check all java objects it points to.
2132 for (EdgeIterator i(this); i.has_next(); i.next()) {
2133 PointsToNode* e = i.get();
2134 if (e->is_JavaObject()) {
2135 Node* n = e->ideal_node();
2136 if ((e->escape_state() != PointsToNode::NoEscape) ||
2137 !(n->is_Allocate() || n->is_CallStaticJava())) {
2138 return false;
2139 }
2140 }
2141 }
2142 return true;
2143 }
2144
2145 // Return true if we know the node does not escape globally.
2146 bool ConnectionGraph::not_global_escape(Node *n) {
2147 assert(!_collecting, "should not call during graph construction");
2148 // If the node was created after the escape computation we can't answer.
2149 uint idx = n->_idx;
2150 if (idx >= nodes_size()) {
2151 return false;
2152 }
2153 PointsToNode* ptn = ptnode_adr(idx);
2154 PointsToNode::EscapeState es = ptn->escape_state();
2155 // If we have already computed a value, return it.
2156 if (es >= PointsToNode::GlobalEscape)
2157 return false;
2158 if (ptn->is_JavaObject()) {
2159 return true; // (es < PointsToNode::GlobalEscape);
2160 }
2161 assert(ptn->is_LocalVar(), "sanity");
2162 // Check all java objects it points to.
2163 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2164 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2165 return false;
2166 }
2167 return true;
2168 }
2169
2170
2171 // Helper functions
2172
2173 // Return true if this node points to specified node or nodes it points to.
2174 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2175 if (is_JavaObject()) {
2176 return (this == ptn);
2177 }
2178 assert(is_LocalVar() || is_Field(), "sanity");
2179 for (EdgeIterator i(this); i.has_next(); i.next()) {
2180 if (i.get() == ptn)
2181 return true;
2182 }
2183 return false;
2184 }
2185
2186 // Return true if one node points to an other.
2187 bool PointsToNode::meet(PointsToNode* ptn) {
2188 if (this == ptn) {
2189 return true;
2190 } else if (ptn->is_JavaObject()) {
2191 return this->points_to(ptn->as_JavaObject());
2192 } else if (this->is_JavaObject()) {
2193 return ptn->points_to(this->as_JavaObject());
2194 }
2195 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2196 int ptn_count = ptn->edge_count();
2197 for (EdgeIterator i(this); i.has_next(); i.next()) {
2198 PointsToNode* this_e = i.get();
2199 for (int j = 0; j < ptn_count; j++) {
2200 if (this_e == ptn->edge(j))
2201 return true;
2202 }
2203 }
2204 return false;
2205 }
2206
2207 #ifdef ASSERT
2208 // Return true if bases point to this java object.
2209 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2210 for (BaseIterator i(this); i.has_next(); i.next()) {
2211 if (i.get() == jobj)
2212 return true;
2213 }
2214 return false;
2215 }
2216 #endif
2217
2218 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2219 const Type *adr_type = phase->type(adr);
2220 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2221 adr->in(AddPNode::Address)->is_Proj() &&
2222 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2223 // We are computing a raw address for a store captured by an Initialize
2224 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2225 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2226 assert(offs != Type::OffsetBot ||
2227 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2228 "offset must be a constant or it is initialization of array");
2229 return offs;
2230 }
2231 const TypePtr *t_ptr = adr_type->isa_ptr();
2232 assert(t_ptr != NULL, "must be a pointer type");
2233 return t_ptr->offset();
2234 }
2235
2236 Node* ConnectionGraph::get_addp_base(Node *addp) {
2237 assert(addp->is_AddP(), "must be AddP");
2238 //
2239 // AddP cases for Base and Address inputs:
2240 // case #1. Direct object's field reference:
2241 // Allocate
2242 // |
2243 // Proj #5 ( oop result )
2244 // |
2245 // CheckCastPP (cast to instance type)
2246 // | |
2247 // AddP ( base == address )
2248 //
2249 // case #2. Indirect object's field reference:
2250 // Phi
2251 // |
2252 // CastPP (cast to instance type)
2253 // | |
2254 // AddP ( base == address )
2255 //
2256 // case #3. Raw object's field reference for Initialize node:
2257 // Allocate
2258 // |
2259 // Proj #5 ( oop result )
2260 // top |
2261 // \ |
2262 // AddP ( base == top )
2263 //
2264 // case #4. Array's element reference:
2265 // {CheckCastPP | CastPP}
2266 // | | |
2267 // | AddP ( array's element offset )
2268 // | |
2269 // AddP ( array's offset )
2270 //
2271 // case #5. Raw object's field reference for arraycopy stub call:
2272 // The inline_native_clone() case when the arraycopy stub is called
2273 // after the allocation before Initialize and CheckCastPP nodes.
2274 // Allocate
2275 // |
2276 // Proj #5 ( oop result )
2277 // | |
2278 // AddP ( base == address )
2279 //
2280 // case #6. Constant Pool, ThreadLocal, CastX2P or
2281 // Raw object's field reference:
2282 // {ConP, ThreadLocal, CastX2P, raw Load}
2283 // top |
2284 // \ |
2285 // AddP ( base == top )
2286 //
2287 // case #7. Klass's field reference.
2288 // LoadKlass
2289 // | |
2290 // AddP ( base == address )
2291 //
2292 // case #8. narrow Klass's field reference.
2293 // LoadNKlass
2294 // |
2295 // DecodeN
2296 // | |
2297 // AddP ( base == address )
2298 //
2299 Node *base = addp->in(AddPNode::Base);
2300 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2301 base = addp->in(AddPNode::Address);
2302 while (base->is_AddP()) {
2303 // Case #6 (unsafe access) may have several chained AddP nodes.
2304 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2305 base = base->in(AddPNode::Address);
2306 }
2307 Node* uncast_base = base->uncast();
2308 int opcode = uncast_base->Opcode();
2309 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2310 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2311 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2312 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2313 }
2314 return base;
2315 }
2316
2317 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2318 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2319 Node* addp2 = addp->raw_out(0);
2320 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2321 addp2->in(AddPNode::Base) == n &&
2322 addp2->in(AddPNode::Address) == addp) {
2323 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2324 //
2325 // Find array's offset to push it on worklist first and
2326 // as result process an array's element offset first (pushed second)
2327 // to avoid CastPP for the array's offset.
2328 // Otherwise the inserted CastPP (LocalVar) will point to what
2329 // the AddP (Field) points to. Which would be wrong since
2330 // the algorithm expects the CastPP has the same point as
2331 // as AddP's base CheckCastPP (LocalVar).
2332 //
2333 // ArrayAllocation
2334 // |
2335 // CheckCastPP
2336 // |
2337 // memProj (from ArrayAllocation CheckCastPP)
2338 // | ||
2339 // | || Int (element index)
2340 // | || | ConI (log(element size))
2341 // | || | /
2342 // | || LShift
2343 // | || /
2344 // | AddP (array's element offset)
2345 // | |
2346 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2347 // | / /
2348 // AddP (array's offset)
2349 // |
2350 // Load/Store (memory operation on array's element)
2351 //
2352 return addp2;
2353 }
2354 return NULL;
2355 }
2356
2357 //
2358 // Adjust the type and inputs of an AddP which computes the
2359 // address of a field of an instance
2360 //
2361 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2362 PhaseGVN* igvn = _igvn;
2363 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2364 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2365 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2366 if (t == NULL) {
2367 // We are computing a raw address for a store captured by an Initialize
2368 // compute an appropriate address type (cases #3 and #5).
2369 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2370 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2371 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2372 assert(offs != Type::OffsetBot, "offset must be a constant");
2373 t = base_t->add_offset(offs)->is_oopptr();
2374 }
2375 int inst_id = base_t->instance_id();
2376 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2377 "old type must be non-instance or match new type");
2378
2379 // The type 't' could be subclass of 'base_t'.
2380 // As result t->offset() could be large then base_t's size and it will
2381 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2382 // constructor verifies correctness of the offset.
2383 //
2384 // It could happened on subclass's branch (from the type profiling
2385 // inlining) which was not eliminated during parsing since the exactness
2386 // of the allocation type was not propagated to the subclass type check.
2387 //
2388 // Or the type 't' could be not related to 'base_t' at all.
2389 // It could happened when CHA type is different from MDO type on a dead path
2390 // (for example, from instanceof check) which is not collapsed during parsing.
2391 //
2392 // Do nothing for such AddP node and don't process its users since
2393 // this code branch will go away.
2394 //
2395 if (!t->is_known_instance() &&
2396 !base_t->klass()->is_subtype_of(t->klass())) {
2397 return false; // bail out
2398 }
2399 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2400 // Do NOT remove the next line: ensure a new alias index is allocated
2401 // for the instance type. Note: C++ will not remove it since the call
2402 // has side effect.
2403 int alias_idx = _compile->get_alias_index(tinst);
2404 igvn->set_type(addp, tinst);
2405 // record the allocation in the node map
2406 set_map(addp, get_map(base->_idx));
2407 // Set addp's Base and Address to 'base'.
2408 Node *abase = addp->in(AddPNode::Base);
2409 Node *adr = addp->in(AddPNode::Address);
2410 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2411 adr->in(0)->_idx == (uint)inst_id) {
2412 // Skip AddP cases #3 and #5.
2413 } else {
2414 assert(!abase->is_top(), "sanity"); // AddP case #3
2415 if (abase != base) {
2416 igvn->hash_delete(addp);
2417 addp->set_req(AddPNode::Base, base);
2418 if (abase == adr) {
2419 addp->set_req(AddPNode::Address, base);
2420 } else {
2421 // AddP case #4 (adr is array's element offset AddP node)
2422 #ifdef ASSERT
2423 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2424 assert(adr->is_AddP() && atype != NULL &&
2425 atype->instance_id() == inst_id, "array's element offset should be processed first");
2426 #endif
2427 }
2428 igvn->hash_insert(addp);
2429 }
2430 }
2431 // Put on IGVN worklist since at least addp's type was changed above.
2432 record_for_optimizer(addp);
2433 return true;
2434 }
2435
2436 //
2437 // Create a new version of orig_phi if necessary. Returns either the newly
2438 // created phi or an existing phi. Sets create_new to indicate whether a new
2439 // phi was created. Cache the last newly created phi in the node map.
2440 //
2441 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2442 Compile *C = _compile;
2443 PhaseGVN* igvn = _igvn;
2444 new_created = false;
2445 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2446 // nothing to do if orig_phi is bottom memory or matches alias_idx
2447 if (phi_alias_idx == alias_idx) {
2448 return orig_phi;
2449 }
2450 // Have we recently created a Phi for this alias index?
2451 PhiNode *result = get_map_phi(orig_phi->_idx);
2452 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2453 return result;
2454 }
2455 // Previous check may fail when the same wide memory Phi was split into Phis
2456 // for different memory slices. Search all Phis for this region.
2457 if (result != NULL) {
2458 Node* region = orig_phi->in(0);
2459 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2460 Node* phi = region->fast_out(i);
2461 if (phi->is_Phi() &&
2462 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2463 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2464 return phi->as_Phi();
2465 }
2466 }
2467 }
2468 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2469 if (C->do_escape_analysis() == true && !C->failing()) {
2470 // Retry compilation without escape analysis.
2471 // If this is the first failure, the sentinel string will "stick"
2472 // to the Compile object, and the C2Compiler will see it and retry.
2473 C->record_failure(C2Compiler::retry_no_escape_analysis());
2474 }
2475 return NULL;
2476 }
2477 orig_phi_worklist.append_if_missing(orig_phi);
2478 const TypePtr *atype = C->get_adr_type(alias_idx);
2479 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2480 C->copy_node_notes_to(result, orig_phi);
2481 igvn->set_type(result, result->bottom_type());
2482 record_for_optimizer(result);
2483 set_map(orig_phi, result);
2484 new_created = true;
2485 return result;
2486 }
2487
2488 //
2489 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2490 // specified alias index.
2491 //
2492 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2493 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2494 Compile *C = _compile;
2495 PhaseGVN* igvn = _igvn;
2496 bool new_phi_created;
2497 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2498 if (!new_phi_created) {
2499 return result;
2500 }
2501 GrowableArray<PhiNode *> phi_list;
2502 GrowableArray<uint> cur_input;
2503 PhiNode *phi = orig_phi;
2504 uint idx = 1;
2505 bool finished = false;
2506 while(!finished) {
2507 while (idx < phi->req()) {
2508 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2509 if (mem != NULL && mem->is_Phi()) {
2510 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2511 if (new_phi_created) {
2512 // found an phi for which we created a new split, push current one on worklist and begin
2513 // processing new one
2514 phi_list.push(phi);
2515 cur_input.push(idx);
2516 phi = mem->as_Phi();
2517 result = newphi;
2518 idx = 1;
2519 continue;
2520 } else {
2521 mem = newphi;
2522 }
2523 }
2524 if (C->failing()) {
2525 return NULL;
2526 }
2527 result->set_req(idx++, mem);
2528 }
2529 #ifdef ASSERT
2530 // verify that the new Phi has an input for each input of the original
2531 assert( phi->req() == result->req(), "must have same number of inputs.");
2532 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2533 #endif
2534 // Check if all new phi's inputs have specified alias index.
2535 // Otherwise use old phi.
2536 for (uint i = 1; i < phi->req(); i++) {
2537 Node* in = result->in(i);
2538 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2539 }
2540 // we have finished processing a Phi, see if there are any more to do
2541 finished = (phi_list.length() == 0 );
2542 if (!finished) {
2543 phi = phi_list.pop();
2544 idx = cur_input.pop();
2545 PhiNode *prev_result = get_map_phi(phi->_idx);
2546 prev_result->set_req(idx++, result);
2547 result = prev_result;
2548 }
2549 }
2550 return result;
2551 }
2552
2553 //
2554 // The next methods are derived from methods in MemNode.
2555 //
2556 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2557 Node *mem = mmem;
2558 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2559 // means an array I have not precisely typed yet. Do not do any
2560 // alias stuff with it any time soon.
2561 if (toop->base() != Type::AnyPtr &&
2562 !(toop->klass() != NULL &&
2563 toop->klass()->is_java_lang_Object() &&
2564 toop->offset() == Type::OffsetBot)) {
2565 mem = mmem->memory_at(alias_idx);
2566 // Update input if it is progress over what we have now
2567 }
2568 return mem;
2569 }
2570
2571 //
2572 // Move memory users to their memory slices.
2573 //
2574 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2575 Compile* C = _compile;
2576 PhaseGVN* igvn = _igvn;
2577 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2578 assert(tp != NULL, "ptr type");
2579 int alias_idx = C->get_alias_index(tp);
2580 int general_idx = C->get_general_index(alias_idx);
2581
2582 // Move users first
2583 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2584 Node* use = n->fast_out(i);
2585 if (use->is_MergeMem()) {
2586 MergeMemNode* mmem = use->as_MergeMem();
2587 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2588 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2589 continue; // Nothing to do
2590 }
2591 // Replace previous general reference to mem node.
2592 uint orig_uniq = C->unique();
2593 Node* m = find_inst_mem(n, general_idx, orig_phis);
2594 assert(orig_uniq == C->unique(), "no new nodes");
2595 mmem->set_memory_at(general_idx, m);
2596 --imax;
2597 --i;
2598 } else if (use->is_MemBar()) {
2599 assert(!use->is_Initialize(), "initializing stores should not be moved");
2600 if (use->req() > MemBarNode::Precedent &&
2601 use->in(MemBarNode::Precedent) == n) {
2602 // Don't move related membars.
2603 record_for_optimizer(use);
2604 continue;
2605 }
2606 tp = use->as_MemBar()->adr_type()->isa_ptr();
2607 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2608 alias_idx == general_idx) {
2609 continue; // Nothing to do
2610 }
2611 // Move to general memory slice.
2612 uint orig_uniq = C->unique();
2613 Node* m = find_inst_mem(n, general_idx, orig_phis);
2614 assert(orig_uniq == C->unique(), "no new nodes");
2615 igvn->hash_delete(use);
2616 imax -= use->replace_edge(n, m);
2617 igvn->hash_insert(use);
2618 record_for_optimizer(use);
2619 --i;
2620 #ifdef ASSERT
2621 } else if (use->is_Mem()) {
2622 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2623 // Don't move related cardmark.
2624 continue;
2625 }
2626 // Memory nodes should have new memory input.
2627 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2628 assert(tp != NULL, "ptr type");
2629 int idx = C->get_alias_index(tp);
2630 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2631 "Following memory nodes should have new memory input or be on the same memory slice");
2632 } else if (use->is_Phi()) {
2633 // Phi nodes should be split and moved already.
2634 tp = use->as_Phi()->adr_type()->isa_ptr();
2635 assert(tp != NULL, "ptr type");
2636 int idx = C->get_alias_index(tp);
2637 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2638 } else {
2639 use->dump();
2640 assert(false, "should not be here");
2641 #endif
2642 }
2643 }
2644 }
2645
2646 //
2647 // Search memory chain of "mem" to find a MemNode whose address
2648 // is the specified alias index.
2649 //
2650 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2651 if (orig_mem == NULL)
2652 return orig_mem;
2653 Compile* C = _compile;
2654 PhaseGVN* igvn = _igvn;
2655 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2656 bool is_instance = (toop != NULL) && toop->is_known_instance();
2657 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2658 Node *prev = NULL;
2659 Node *result = orig_mem;
2660 while (prev != result) {
2661 prev = result;
2662 if (result == start_mem)
2663 break; // hit one of our sentinels
2664 if (result->is_Mem()) {
2665 const Type *at = igvn->type(result->in(MemNode::Address));
2666 if (at == Type::TOP)
2667 break; // Dead
2668 assert (at->isa_ptr() != NULL, "pointer type required.");
2669 int idx = C->get_alias_index(at->is_ptr());
2670 if (idx == alias_idx)
2671 break; // Found
2672 if (!is_instance && (at->isa_oopptr() == NULL ||
2673 !at->is_oopptr()->is_known_instance())) {
2674 break; // Do not skip store to general memory slice.
2675 }
2676 result = result->in(MemNode::Memory);
2677 }
2678 if (!is_instance)
2679 continue; // don't search further for non-instance types
2680 // skip over a call which does not affect this memory slice
2681 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2682 Node *proj_in = result->in(0);
2683 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2684 break; // hit one of our sentinels
2685 } else if (proj_in->is_Call()) {
2686 // ArrayCopy node processed here as well
2687 CallNode *call = proj_in->as_Call();
2688 if (!call->may_modify(toop, igvn)) {
2689 result = call->in(TypeFunc::Memory);
2690 }
2691 } else if (proj_in->is_Initialize()) {
2692 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2693 // Stop if this is the initialization for the object instance which
2694 // which contains this memory slice, otherwise skip over it.
2695 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2696 result = proj_in->in(TypeFunc::Memory);
2697 }
2698 } else if (proj_in->is_MemBar()) {
2699 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2700 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2701 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2702 // clone
2703 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2704 if (ac->may_modify(toop, igvn)) {
2705 break;
2706 }
2707 }
2708 result = proj_in->in(TypeFunc::Memory);
2709 }
2710 } else if (result->is_MergeMem()) {
2711 MergeMemNode *mmem = result->as_MergeMem();
2712 result = step_through_mergemem(mmem, alias_idx, toop);
2713 if (result == mmem->base_memory()) {
2714 // Didn't find instance memory, search through general slice recursively.
2715 result = mmem->memory_at(C->get_general_index(alias_idx));
2716 result = find_inst_mem(result, alias_idx, orig_phis);
2717 if (C->failing()) {
2718 return NULL;
2719 }
2720 mmem->set_memory_at(alias_idx, result);
2721 }
2722 } else if (result->is_Phi() &&
2723 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2724 Node *un = result->as_Phi()->unique_input(igvn);
2725 if (un != NULL) {
2726 orig_phis.append_if_missing(result->as_Phi());
2727 result = un;
2728 } else {
2729 break;
2730 }
2731 } else if (result->is_ClearArray()) {
2732 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2733 // Can not bypass initialization of the instance
2734 // we are looking for.
2735 break;
2736 }
2737 // Otherwise skip it (the call updated 'result' value).
2738 } else if (result->Opcode() == Op_SCMemProj) {
2739 Node* mem = result->in(0);
2740 Node* adr = NULL;
2741 if (mem->is_LoadStore()) {
2742 adr = mem->in(MemNode::Address);
2743 } else {
2744 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
2745 adr = mem->in(3); // Memory edge corresponds to destination array
2746 }
2747 const Type *at = igvn->type(adr);
2748 if (at != Type::TOP) {
2749 assert (at->isa_ptr() != NULL, "pointer type required.");
2750 int idx = C->get_alias_index(at->is_ptr());
2751 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
2752 break;
2753 }
2754 result = mem->in(MemNode::Memory);
2755 }
2756 }
2757 if (result->is_Phi()) {
2758 PhiNode *mphi = result->as_Phi();
2759 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2760 const TypePtr *t = mphi->adr_type();
2761 if (!is_instance) {
2762 // Push all non-instance Phis on the orig_phis worklist to update inputs
2763 // during Phase 4 if needed.
2764 orig_phis.append_if_missing(mphi);
2765 } else if (C->get_alias_index(t) != alias_idx) {
2766 // Create a new Phi with the specified alias index type.
2767 result = split_memory_phi(mphi, alias_idx, orig_phis);
2768 }
2769 }
2770 // the result is either MemNode, PhiNode, InitializeNode.
2771 return result;
2772 }
2773
2774 //
2775 // Convert the types of unescaped object to instance types where possible,
2776 // propagate the new type information through the graph, and update memory
2777 // edges and MergeMem inputs to reflect the new type.
2778 //
2779 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2780 // The processing is done in 4 phases:
2781 //
2782 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2783 // types for the CheckCastPP for allocations where possible.
2784 // Propagate the new types through users as follows:
2785 // casts and Phi: push users on alloc_worklist
2786 // AddP: cast Base and Address inputs to the instance type
2787 // push any AddP users on alloc_worklist and push any memnode
2788 // users onto memnode_worklist.
2789 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2790 // search the Memory chain for a store with the appropriate type
2791 // address type. If a Phi is found, create a new version with
2792 // the appropriate memory slices from each of the Phi inputs.
2793 // For stores, process the users as follows:
2794 // MemNode: push on memnode_worklist
2795 // MergeMem: push on mergemem_worklist
2796 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2797 // moving the first node encountered of each instance type to the
2798 // the input corresponding to its alias index.
2799 // appropriate memory slice.
2800 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2801 //
2802 // In the following example, the CheckCastPP nodes are the cast of allocation
2803 // results and the allocation of node 29 is unescaped and eligible to be an
2804 // instance type.
2805 //
2806 // We start with:
2807 //
2808 // 7 Parm #memory
2809 // 10 ConI "12"
2810 // 19 CheckCastPP "Foo"
2811 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2812 // 29 CheckCastPP "Foo"
2813 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2814 //
2815 // 40 StoreP 25 7 20 ... alias_index=4
2816 // 50 StoreP 35 40 30 ... alias_index=4
2817 // 60 StoreP 45 50 20 ... alias_index=4
2818 // 70 LoadP _ 60 30 ... alias_index=4
2819 // 80 Phi 75 50 60 Memory alias_index=4
2820 // 90 LoadP _ 80 30 ... alias_index=4
2821 // 100 LoadP _ 80 20 ... alias_index=4
2822 //
2823 //
2824 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2825 // and creating a new alias index for node 30. This gives:
2826 //
2827 // 7 Parm #memory
2828 // 10 ConI "12"
2829 // 19 CheckCastPP "Foo"
2830 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2831 // 29 CheckCastPP "Foo" iid=24
2832 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2833 //
2834 // 40 StoreP 25 7 20 ... alias_index=4
2835 // 50 StoreP 35 40 30 ... alias_index=6
2836 // 60 StoreP 45 50 20 ... alias_index=4
2837 // 70 LoadP _ 60 30 ... alias_index=6
2838 // 80 Phi 75 50 60 Memory alias_index=4
2839 // 90 LoadP _ 80 30 ... alias_index=6
2840 // 100 LoadP _ 80 20 ... alias_index=4
2841 //
2842 // In phase 2, new memory inputs are computed for the loads and stores,
2843 // And a new version of the phi is created. In phase 4, the inputs to
2844 // node 80 are updated and then the memory nodes are updated with the
2845 // values computed in phase 2. This results in:
2846 //
2847 // 7 Parm #memory
2848 // 10 ConI "12"
2849 // 19 CheckCastPP "Foo"
2850 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2851 // 29 CheckCastPP "Foo" iid=24
2852 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2853 //
2854 // 40 StoreP 25 7 20 ... alias_index=4
2855 // 50 StoreP 35 7 30 ... alias_index=6
2856 // 60 StoreP 45 40 20 ... alias_index=4
2857 // 70 LoadP _ 50 30 ... alias_index=6
2858 // 80 Phi 75 40 60 Memory alias_index=4
2859 // 120 Phi 75 50 50 Memory alias_index=6
2860 // 90 LoadP _ 120 30 ... alias_index=6
2861 // 100 LoadP _ 80 20 ... alias_index=4
2862 //
2863 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2864 GrowableArray<Node *> memnode_worklist;
2865 GrowableArray<PhiNode *> orig_phis;
2866 PhaseIterGVN *igvn = _igvn;
2867 uint new_index_start = (uint) _compile->num_alias_types();
2868 Arena* arena = Thread::current()->resource_area();
2869 VectorSet visited(arena);
2870 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2871 uint unique_old = _compile->unique();
2872
2873 // Phase 1: Process possible allocations from alloc_worklist.
2874 // Create instance types for the CheckCastPP for allocations where possible.
2875 //
2876 // (Note: don't forget to change the order of the second AddP node on
2877 // the alloc_worklist if the order of the worklist processing is changed,
2878 // see the comment in find_second_addp().)
2879 //
2880 while (alloc_worklist.length() != 0) {
2881 Node *n = alloc_worklist.pop();
2882 uint ni = n->_idx;
2883 if (n->is_Call()) {
2884 CallNode *alloc = n->as_Call();
2885 // copy escape information to call node
2886 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2887 PointsToNode::EscapeState es = ptn->escape_state();
2888 // We have an allocation or call which returns a Java object,
2889 // see if it is unescaped.
2890 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2891 continue;
2892 // Find CheckCastPP for the allocate or for the return value of a call
2893 n = alloc->result_cast();
2894 if (n == NULL) { // No uses except Initialize node
2895 if (alloc->is_Allocate()) {
2896 // Set the scalar_replaceable flag for allocation
2897 // so it could be eliminated if it has no uses.
2898 alloc->as_Allocate()->_is_scalar_replaceable = true;
2899 }
2900 if (alloc->is_CallStaticJava()) {
2901 // Set the scalar_replaceable flag for boxing method
2902 // so it could be eliminated if it has no uses.
2903 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2904 }
2905 continue;
2906 }
2907 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2908 assert(!alloc->is_Allocate(), "allocation should have unique type");
2909 continue;
2910 }
2911
2912 // The inline code for Object.clone() casts the allocation result to
2913 // java.lang.Object and then to the actual type of the allocated
2914 // object. Detect this case and use the second cast.
2915 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2916 // the allocation result is cast to java.lang.Object and then
2917 // to the actual Array type.
2918 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2919 && (alloc->is_AllocateArray() ||
2920 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2921 Node *cast2 = NULL;
2922 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2923 Node *use = n->fast_out(i);
2924 if (use->is_CheckCastPP()) {
2925 cast2 = use;
2926 break;
2927 }
2928 }
2929 if (cast2 != NULL) {
2930 n = cast2;
2931 } else {
2932 // Non-scalar replaceable if the allocation type is unknown statically
2933 // (reflection allocation), the object can't be restored during
2934 // deoptimization without precise type.
2935 continue;
2936 }
2937 }
2938
2939 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2940 if (t == NULL)
2941 continue; // not a TypeOopPtr
2942 if (!t->klass_is_exact())
2943 continue; // not an unique type
2944
2945 if (alloc->is_Allocate()) {
2946 // Set the scalar_replaceable flag for allocation
2947 // so it could be eliminated.
2948 alloc->as_Allocate()->_is_scalar_replaceable = true;
2949 }
2950 if (alloc->is_CallStaticJava()) {
2951 // Set the scalar_replaceable flag for boxing method
2952 // so it could be eliminated.
2953 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2954 }
2955 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
2956 // in order for an object to be scalar-replaceable, it must be:
2957 // - a direct allocation (not a call returning an object)
2958 // - non-escaping
2959 // - eligible to be a unique type
2960 // - not determined to be ineligible by escape analysis
2961 set_map(alloc, n);
2962 set_map(n, alloc);
2963 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
2964 igvn->hash_delete(n);
2965 igvn->set_type(n, tinst);
2966 n->raise_bottom_type(tinst);
2967 igvn->hash_insert(n);
2968 record_for_optimizer(n);
2969 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
2970
2971 // First, put on the worklist all Field edges from Connection Graph
2972 // which is more accurate than putting immediate users from Ideal Graph.
2973 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
2974 PointsToNode* tgt = e.get();
2975 if (tgt->is_Arraycopy()) {
2976 continue;
2977 }
2978 Node* use = tgt->ideal_node();
2979 assert(tgt->is_Field() && use->is_AddP(),
2980 "only AddP nodes are Field edges in CG");
2981 if (use->outcnt() > 0) { // Don't process dead nodes
2982 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
2983 if (addp2 != NULL) {
2984 assert(alloc->is_AllocateArray(),"array allocation was expected");
2985 alloc_worklist.append_if_missing(addp2);
2986 }
2987 alloc_worklist.append_if_missing(use);
2988 }
2989 }
2990
2991 // An allocation may have an Initialize which has raw stores. Scan
2992 // the users of the raw allocation result and push AddP users
2993 // on alloc_worklist.
2994 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
2995 assert (raw_result != NULL, "must have an allocation result");
2996 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
2997 Node *use = raw_result->fast_out(i);
2998 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
2999 Node* addp2 = find_second_addp(use, raw_result);
3000 if (addp2 != NULL) {
3001 assert(alloc->is_AllocateArray(),"array allocation was expected");
3002 alloc_worklist.append_if_missing(addp2);
3003 }
3004 alloc_worklist.append_if_missing(use);
3005 } else if (use->is_MemBar()) {
3006 memnode_worklist.append_if_missing(use);
3007 }
3008 }
3009 }
3010 } else if (n->is_AddP()) {
3011 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3012 if (jobj == NULL || jobj == phantom_obj) {
3013 #ifdef ASSERT
3014 ptnode_adr(get_addp_base(n)->_idx)->dump();
3015 ptnode_adr(n->_idx)->dump();
3016 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3017 #endif
3018 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3019 return;
3020 }
3021 Node *base = get_map(jobj->idx()); // CheckCastPP node
3022 if (!split_AddP(n, base)) continue; // wrong type from dead path
3023 } else if (n->is_Phi() ||
3024 n->is_CheckCastPP() ||
3025 n->is_EncodeP() ||
3026 n->is_DecodeN() ||
3027 n->is_ShenandoahBarrier() ||
3028 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3029 if (visited.test_set(n->_idx)) {
3030 assert(n->is_Phi(), "loops only through Phi's");
3031 continue; // already processed
3032 }
3033 JavaObjectNode* jobj = unique_java_object(n);
3034 if (jobj == NULL || jobj == phantom_obj) {
3035 #ifdef ASSERT
3036 ptnode_adr(n->_idx)->dump();
3037 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3038 #endif
3039 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3040 return;
3041 } else {
3042 Node *val = get_map(jobj->idx()); // CheckCastPP node
3043 TypeNode *tn = n->as_Type();
3044 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3045 assert(tinst != NULL && tinst->is_known_instance() &&
3046 tinst->instance_id() == jobj->idx() , "instance type expected.");
3047
3048 const Type *tn_type = igvn->type(tn);
3049 const TypeOopPtr *tn_t;
3050 if (tn_type->isa_narrowoop()) {
3051 tn_t = tn_type->make_ptr()->isa_oopptr();
3052 } else {
3053 tn_t = tn_type->isa_oopptr();
3054 }
3055 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3056 if (tn_type->isa_narrowoop()) {
3057 tn_type = tinst->make_narrowoop();
3058 } else {
3059 tn_type = tinst;
3060 }
3061 igvn->hash_delete(tn);
3062 igvn->set_type(tn, tn_type);
3063 tn->set_type(tn_type);
3064 igvn->hash_insert(tn);
3065 record_for_optimizer(n);
3066 } else {
3067 assert(tn_type == TypePtr::NULL_PTR ||
3068 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3069 "unexpected type");
3070 continue; // Skip dead path with different type
3071 }
3072 }
3073 } else {
3074 debug_only(n->dump();)
3075 assert(false, "EA: unexpected node");
3076 continue;
3077 }
3078 // push allocation's users on appropriate worklist
3079 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3080 Node *use = n->fast_out(i);
3081 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3082 // Load/store to instance's field
3083 memnode_worklist.append_if_missing(use);
3084 } else if (use->is_MemBar()) {
3085 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3086 memnode_worklist.append_if_missing(use);
3087 }
3088 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3089 Node* addp2 = find_second_addp(use, n);
3090 if (addp2 != NULL) {
3091 alloc_worklist.append_if_missing(addp2);
3092 }
3093 alloc_worklist.append_if_missing(use);
3094 } else if (use->is_Phi() ||
3095 use->is_CheckCastPP() ||
3096 use->is_EncodeNarrowPtr() ||
3097 use->is_DecodeNarrowPtr() ||
3098 use->is_ShenandoahBarrier() ||
3099 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3100 alloc_worklist.append_if_missing(use);
3101 #ifdef ASSERT
3102 } else if (use->is_Mem()) {
3103 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3104 } else if (use->is_MergeMem()) {
3105 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3106 } else if (use->is_SafePoint()) {
3107 // Look for MergeMem nodes for calls which reference unique allocation
3108 // (through CheckCastPP nodes) even for debug info.
3109 Node* m = use->in(TypeFunc::Memory);
3110 if (m->is_MergeMem()) {
3111 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3112 }
3113 } else if (use->Opcode() == Op_EncodeISOArray) {
3114 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3115 // EncodeISOArray overwrites destination array
3116 memnode_worklist.append_if_missing(use);
3117 }
3118 } else {
3119 uint op = use->Opcode();
3120 if (!(op == Op_CmpP || op == Op_Conv2B ||
3121 op == Op_CastP2X || op == Op_StoreCM ||
3122 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
3123 op == Op_StrEquals || op == Op_StrIndexOf ||
3124 op == Op_ShenandoahWBMemProj)) {
3125 n->dump();
3126 use->dump();
3127 assert(false, "EA: missing allocation reference path");
3128 }
3129 #endif
3130 }
3131 }
3132
3133 }
3134
3135 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3136 // type, record it in the ArrayCopy node so we know what memory this
3137 // node uses/modified.
3138 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3139 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3140 Node* dest = ac->in(ArrayCopyNode::Dest);
3141 if (dest->is_AddP()) {
3142 dest = get_addp_base(dest);
3143 }
3144 JavaObjectNode* jobj = unique_java_object(dest);
3145 if (jobj != NULL) {
3146 Node *base = get_map(jobj->idx());
3147 if (base != NULL) {
3148 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3149 ac->_dest_type = base_t;
3150 }
3151 }
3152 Node* src = ac->in(ArrayCopyNode::Src);
3153 if (src->is_AddP()) {
3154 src = get_addp_base(src);
3155 }
3156 jobj = unique_java_object(src);
3157 if (jobj != NULL) {
3158 Node* base = get_map(jobj->idx());
3159 if (base != NULL) {
3160 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3161 ac->_src_type = base_t;
3162 }
3163 }
3164 }
3165
3166 // New alias types were created in split_AddP().
3167 uint new_index_end = (uint) _compile->num_alias_types();
3168 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3169
3170 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3171 // compute new values for Memory inputs (the Memory inputs are not
3172 // actually updated until phase 4.)
3173 if (memnode_worklist.length() == 0)
3174 return; // nothing to do
3175 while (memnode_worklist.length() != 0) {
3176 Node *n = memnode_worklist.pop();
3177 if (visited.test_set(n->_idx))
3178 continue;
3179 if (n->is_Phi() || n->is_ClearArray()) {
3180 // we don't need to do anything, but the users must be pushed
3181 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3182 // we don't need to do anything, but the users must be pushed
3183 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3184 if (n == NULL)
3185 continue;
3186 } else if (n->Opcode() == Op_EncodeISOArray) {
3187 // get the memory projection
3188 n = n->find_out_with(Op_SCMemProj);
3189 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3190 } else {
3191 assert(n->is_Mem(), "memory node required.");
3192 Node *addr = n->in(MemNode::Address);
3193 const Type *addr_t = igvn->type(addr);
3194 if (addr_t == Type::TOP)
3195 continue;
3196 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3197 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3198 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3199 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3200 if (_compile->failing()) {
3201 return;
3202 }
3203 if (mem != n->in(MemNode::Memory)) {
3204 // We delay the memory edge update since we need old one in
3205 // MergeMem code below when instances memory slices are separated.
3206 set_map(n, mem);
3207 }
3208 if (n->is_Load()) {
3209 continue; // don't push users
3210 } else if (n->is_LoadStore()) {
3211 // get the memory projection
3212 n = n->find_out_with(Op_SCMemProj);
3213 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3214 }
3215 }
3216 // push user on appropriate worklist
3217 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3218 Node *use = n->fast_out(i);
3219 if (use->is_Phi() || use->is_ClearArray()) {
3220 memnode_worklist.append_if_missing(use);
3221 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3222 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3223 continue;
3224 memnode_worklist.append_if_missing(use);
3225 } else if (use->is_MemBar()) {
3226 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3227 memnode_worklist.append_if_missing(use);
3228 }
3229 #ifdef ASSERT
3230 } else if(use->is_Mem()) {
3231 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3232 } else if (use->is_MergeMem()) {
3233 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3234 } else if (use->Opcode() == Op_EncodeISOArray) {
3235 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3236 // EncodeISOArray overwrites destination array
3237 memnode_worklist.append_if_missing(use);
3238 }
3239 } else {
3240 uint op = use->Opcode();
3241 if (!(op == Op_StoreCM ||
3242 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3243 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3244 op == Op_AryEq || op == Op_StrComp ||
3245 op == Op_StrEquals || op == Op_StrIndexOf)) {
3246 n->dump();
3247 use->dump();
3248 assert(false, "EA: missing memory path");
3249 }
3250 #endif
3251 }
3252 }
3253 }
3254
3255 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3256 // Walk each memory slice moving the first node encountered of each
3257 // instance type to the the input corresponding to its alias index.
3258 uint length = _mergemem_worklist.length();
3259 for( uint next = 0; next < length; ++next ) {
3260 MergeMemNode* nmm = _mergemem_worklist.at(next);
3261 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3262 // Note: we don't want to use MergeMemStream here because we only want to
3263 // scan inputs which exist at the start, not ones we add during processing.
3264 // Note 2: MergeMem may already contains instance memory slices added
3265 // during find_inst_mem() call when memory nodes were processed above.
3266 igvn->hash_delete(nmm);
3267 uint nslices = MIN2(nmm->req(), new_index_start);
3268 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3269 Node* mem = nmm->in(i);
3270 Node* cur = NULL;
3271 if (mem == NULL || mem->is_top())
3272 continue;
3273 // First, update mergemem by moving memory nodes to corresponding slices
3274 // if their type became more precise since this mergemem was created.
3275 while (mem->is_Mem()) {
3276 const Type *at = igvn->type(mem->in(MemNode::Address));
3277 if (at != Type::TOP) {
3278 assert (at->isa_ptr() != NULL, "pointer type required.");
3279 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3280 if (idx == i) {
3281 if (cur == NULL)
3282 cur = mem;
3283 } else {
3284 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3285 nmm->set_memory_at(idx, mem);
3286 }
3287 }
3288 }
3289 mem = mem->in(MemNode::Memory);
3290 }
3291 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3292 // Find any instance of the current type if we haven't encountered
3293 // already a memory slice of the instance along the memory chain.
3294 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3295 if((uint)_compile->get_general_index(ni) == i) {
3296 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3297 if (nmm->is_empty_memory(m)) {
3298 Node* result = find_inst_mem(mem, ni, orig_phis);
3299 if (_compile->failing()) {
3300 return;
3301 }
3302 nmm->set_memory_at(ni, result);
3303 }
3304 }
3305 }
3306 }
3307 // Find the rest of instances values
3308 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3309 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3310 Node* result = step_through_mergemem(nmm, ni, tinst);
3311 if (result == nmm->base_memory()) {
3312 // Didn't find instance memory, search through general slice recursively.
3313 result = nmm->memory_at(_compile->get_general_index(ni));
3314 result = find_inst_mem(result, ni, orig_phis);
3315 if (_compile->failing()) {
3316 return;
3317 }
3318 nmm->set_memory_at(ni, result);
3319 }
3320 }
3321 igvn->hash_insert(nmm);
3322 record_for_optimizer(nmm);
3323 }
3324
3325 // Phase 4: Update the inputs of non-instance memory Phis and
3326 // the Memory input of memnodes
3327 // First update the inputs of any non-instance Phi's from
3328 // which we split out an instance Phi. Note we don't have
3329 // to recursively process Phi's encounted on the input memory
3330 // chains as is done in split_memory_phi() since they will
3331 // also be processed here.
3332 for (int j = 0; j < orig_phis.length(); j++) {
3333 PhiNode *phi = orig_phis.at(j);
3334 int alias_idx = _compile->get_alias_index(phi->adr_type());
3335 igvn->hash_delete(phi);
3336 for (uint i = 1; i < phi->req(); i++) {
3337 Node *mem = phi->in(i);
3338 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3339 if (_compile->failing()) {
3340 return;
3341 }
3342 if (mem != new_mem) {
3343 phi->set_req(i, new_mem);
3344 }
3345 }
3346 igvn->hash_insert(phi);
3347 record_for_optimizer(phi);
3348 }
3349
3350 // Update the memory inputs of MemNodes with the value we computed
3351 // in Phase 2 and move stores memory users to corresponding memory slices.
3352 // Disable memory split verification code until the fix for 6984348.
3353 // Currently it produces false negative results since it does not cover all cases.
3354 #if 0 // ifdef ASSERT
3355 visited.Reset();
3356 Node_Stack old_mems(arena, _compile->unique() >> 2);
3357 #endif
3358 for (uint i = 0; i < ideal_nodes.size(); i++) {
3359 Node* n = ideal_nodes.at(i);
3360 Node* nmem = get_map(n->_idx);
3361 assert(nmem != NULL, "sanity");
3362 if (n->is_Mem()) {
3363 #if 0 // ifdef ASSERT
3364 Node* old_mem = n->in(MemNode::Memory);
3365 if (!visited.test_set(old_mem->_idx)) {
3366 old_mems.push(old_mem, old_mem->outcnt());
3367 }
3368 #endif
3369 assert(n->in(MemNode::Memory) != nmem, "sanity");
3370 if (!n->is_Load()) {
3371 // Move memory users of a store first.
3372 move_inst_mem(n, orig_phis);
3373 }
3374 // Now update memory input
3375 igvn->hash_delete(n);
3376 n->set_req(MemNode::Memory, nmem);
3377 igvn->hash_insert(n);
3378 record_for_optimizer(n);
3379 } else {
3380 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3381 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3382 }
3383 }
3384 #if 0 // ifdef ASSERT
3385 // Verify that memory was split correctly
3386 while (old_mems.is_nonempty()) {
3387 Node* old_mem = old_mems.node();
3388 uint old_cnt = old_mems.index();
3389 old_mems.pop();
3390 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3391 }
3392 #endif
3393 }
3394
3395 #ifndef PRODUCT
3396 static const char *node_type_names[] = {
3397 "UnknownType",
3398 "JavaObject",
3399 "LocalVar",
3400 "Field",
3401 "Arraycopy"
3402 };
3403
3404 static const char *esc_names[] = {
3405 "UnknownEscape",
3406 "NoEscape",
3407 "ArgEscape",
3408 "GlobalEscape"
3409 };
3410
3411 void PointsToNode::dump(bool print_state) const {
3412 NodeType nt = node_type();
3413 tty->print("%s ", node_type_names[(int) nt]);
3414 if (print_state) {
3415 EscapeState es = escape_state();
3416 EscapeState fields_es = fields_escape_state();
3417 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3418 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3419 tty->print("NSR ");
3420 }
3421 if (is_Field()) {
3422 FieldNode* f = (FieldNode*)this;
3423 if (f->is_oop())
3424 tty->print("oop ");
3425 if (f->offset() > 0)
3426 tty->print("+%d ", f->offset());
3427 tty->print("(");
3428 for (BaseIterator i(f); i.has_next(); i.next()) {
3429 PointsToNode* b = i.get();
3430 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3431 }
3432 tty->print(" )");
3433 }
3434 tty->print("[");
3435 for (EdgeIterator i(this); i.has_next(); i.next()) {
3436 PointsToNode* e = i.get();
3437 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3438 }
3439 tty->print(" [");
3440 for (UseIterator i(this); i.has_next(); i.next()) {
3441 PointsToNode* u = i.get();
3442 bool is_base = false;
3443 if (PointsToNode::is_base_use(u)) {
3444 is_base = true;
3445 u = PointsToNode::get_use_node(u)->as_Field();
3446 }
3447 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3448 }
3449 tty->print(" ]] ");
3450 if (_node == NULL)
3451 tty->print_cr("<null>");
3452 else
3453 _node->dump();
3454 }
3455
3456 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3457 bool first = true;
3458 int ptnodes_length = ptnodes_worklist.length();
3459 for (int i = 0; i < ptnodes_length; i++) {
3460 PointsToNode *ptn = ptnodes_worklist.at(i);
3461 if (ptn == NULL || !ptn->is_JavaObject())
3462 continue;
3463 PointsToNode::EscapeState es = ptn->escape_state();
3464 if ((es != PointsToNode::NoEscape) && !Verbose) {
3465 continue;
3466 }
3467 Node* n = ptn->ideal_node();
3468 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3469 n->as_CallStaticJava()->is_boxing_method())) {
3470 if (first) {
3471 tty->cr();
3472 tty->print("======== Connection graph for ");
3473 _compile->method()->print_short_name();
3474 tty->cr();
3475 first = false;
3476 }
3477 ptn->dump();
3478 // Print all locals and fields which reference this allocation
3479 for (UseIterator j(ptn); j.has_next(); j.next()) {
3480 PointsToNode* use = j.get();
3481 if (use->is_LocalVar()) {
3482 use->dump(Verbose);
3483 } else if (Verbose) {
3484 use->dump();
3485 }
3486 }
3487 tty->cr();
3488 }
3489 }
3490 }
3491 #endif