1 /*
2 * Copyright (c) 2005, 2021, 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/shared/barrierSet.hpp"
29 #include "gc/shared/c2/barrierSetC2.hpp"
30 #include "libadt/vectset.hpp"
31 #include "memory/allocation.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "opto/c2compiler.hpp"
34 #include "opto/arraycopynode.hpp"
35 #include "opto/callnode.hpp"
36 #include "opto/cfgnode.hpp"
37 #include "opto/compile.hpp"
38 #include "opto/escape.hpp"
39 #include "opto/phaseX.hpp"
40 #include "opto/movenode.hpp"
41 #include "opto/rootnode.hpp"
42 #include "utilities/macros.hpp"
43
44 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
45 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
46 _in_worklist(C->comp_arena()),
47 _next_pidx(0),
48 _collecting(true),
49 _verify(false),
50 _compile(C),
51 _igvn(igvn),
52 _node_map(C->comp_arena()) {
53 // Add unknown java object.
54 add_java_object(C->top(), PointsToNode::GlobalEscape);
55 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
56 // Add ConP(#NULL) and ConN(#NULL) nodes.
57 Node* oop_null = igvn->zerocon(T_OBJECT);
58 assert(oop_null->_idx < nodes_size(), "should be created already");
59 add_java_object(oop_null, PointsToNode::NoEscape);
60 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
61 if (UseCompressedOops) {
62 Node* noop_null = igvn->zerocon(T_NARROWOOP);
63 assert(noop_null->_idx < nodes_size(), "should be created already");
64 map_ideal_node(noop_null, null_obj);
65 }
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 }
77 if (n->is_Lock()) {
78 Node* obj = n->as_Lock()->obj_node()->uncast();
79 if (!(obj->is_Parm() || obj->is_Con())) {
80 return true;
81 }
82 }
83 if (n->is_CallStaticJava() &&
84 n->as_CallStaticJava()->is_boxing_method()) {
85 return true;
86 }
87 }
88 return false;
89 }
90
91 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
92 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
93 ResourceMark rm;
94
95 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
96 // to create space for them in ConnectionGraph::_nodes[].
97 Node* oop_null = igvn->zerocon(T_OBJECT);
98 Node* noop_null = igvn->zerocon(T_NARROWOOP);
99 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
100 // Perform escape analysis
101 if (congraph->compute_escape()) {
102 // There are non escaping objects.
103 C->set_congraph(congraph);
104 }
105 // Cleanup.
106 if (oop_null->outcnt() == 0) {
107 igvn->hash_delete(oop_null);
108 }
109 if (noop_null->outcnt() == 0) {
110 igvn->hash_delete(noop_null);
111 }
112 }
113
114 bool ConnectionGraph::compute_escape() {
115 Compile* C = _compile;
116 PhaseGVN* igvn = _igvn;
117
118 // Worklists used by EA.
119 Unique_Node_List delayed_worklist;
120 GrowableArray<Node*> alloc_worklist;
121 GrowableArray<Node*> ptr_cmp_worklist;
122 GrowableArray<MemBarStoreStoreNode*> storestore_worklist;
123 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
124 GrowableArray<PointsToNode*> ptnodes_worklist;
125 GrowableArray<JavaObjectNode*> java_objects_worklist;
126 GrowableArray<JavaObjectNode*> non_escaped_allocs_worklist;
127 GrowableArray<FieldNode*> oop_fields_worklist;
128 GrowableArray<SafePointNode*> sfn_worklist;
129 GrowableArray<MergeMemNode*> mergemem_worklist;
130 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
131
132 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
133
134 // 1. Populate Connection Graph (CG) with PointsTo nodes.
135 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
136 // Initialize worklist
137 if (C->root() != NULL) {
138 ideal_nodes.push(C->root());
139 }
140 // Processed ideal nodes are unique on ideal_nodes list
141 // but several ideal nodes are mapped to the phantom_obj.
142 // To avoid duplicated entries on the following worklists
143 // add the phantom_obj only once to them.
144 ptnodes_worklist.append(phantom_obj);
145 java_objects_worklist.append(phantom_obj);
146 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
147 Node* n = ideal_nodes.at(next);
148 // Create PointsTo nodes and add them to Connection Graph. Called
149 // only once per ideal node since ideal_nodes is Unique_Node list.
150 add_node_to_connection_graph(n, &delayed_worklist);
151 PointsToNode* ptn = ptnode_adr(n->_idx);
152 if (ptn != NULL && ptn != phantom_obj) {
153 ptnodes_worklist.append(ptn);
154 if (ptn->is_JavaObject()) {
155 java_objects_worklist.append(ptn->as_JavaObject());
156 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
157 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
158 // Only allocations and java static calls results are interesting.
159 non_escaped_allocs_worklist.append(ptn->as_JavaObject());
160 }
161 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
162 oop_fields_worklist.append(ptn->as_Field());
163 }
164 }
165 // Collect some interesting nodes for futher use.
166 switch (n->Opcode()) {
167 case Op_MergeMem:
168 // Collect all MergeMem nodes to add memory slices for
169 // scalar replaceable objects in split_unique_types().
170 mergemem_worklist.append(n->as_MergeMem());
171 break;
172 case Op_CmpP:
173 case Op_CmpN:
174 // Collect compare pointers nodes.
175 if (OptimizePtrCompare) {
176 ptr_cmp_worklist.append(n);
177 }
178 break;
179 case Op_MemBarStoreStore:
180 // Collect all MemBarStoreStore nodes so that depending on the
181 // escape status of the associated Allocate node some of them
182 // may be eliminated.
183 storestore_worklist.append(n->as_MemBarStoreStore());
184 break;
185 case Op_MemBarRelease:
186 if (n->req() > MemBarNode::Precedent) {
187 record_for_optimizer(n);
188 }
189 break;
190 #ifdef ASSERT
191 case Op_AddP:
192 // Collect address nodes for graph verification.
193 addp_worklist.append(n);
194 break;
195 #endif
196 case Op_ArrayCopy:
197 // Keep a list of ArrayCopy nodes so if one of its input is non
198 // escaping, we can record a unique type
199 arraycopy_worklist.append(n->as_ArrayCopy());
200 break;
201 default:
202 // not interested now, ignore...
203 break;
204 }
205 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
206 Node* m = n->fast_out(i); // Get user
207 ideal_nodes.push(m);
208 }
209 if (n->is_SafePoint()) {
210 sfn_worklist.append(n->as_SafePoint());
211 }
212 }
213 if (non_escaped_allocs_worklist.length() == 0) {
214 _collecting = false;
215 return false; // Nothing to do.
216 }
217 // Add final simple edges to graph.
218 while(delayed_worklist.size() > 0) {
219 Node* n = delayed_worklist.pop();
220 add_final_edges(n);
221 }
222
223 #ifdef ASSERT
224 if (VerifyConnectionGraph) {
225 // Verify that no new simple edges could be created and all
226 // local vars has edges.
227 _verify = true;
228 int ptnodes_length = ptnodes_worklist.length();
229 for (int next = 0; next < ptnodes_length; ++next) {
230 PointsToNode* ptn = ptnodes_worklist.at(next);
231 add_final_edges(ptn->ideal_node());
232 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
233 ptn->dump();
234 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
235 }
236 }
237 _verify = false;
238 }
239 #endif
240 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
241 // processing, calls to CI to resolve symbols (types, fields, methods)
242 // referenced in bytecode. During symbol resolution VM may throw
243 // an exception which CI cleans and converts to compilation failure.
244 if (C->failing()) return false;
245
246 // 2. Finish Graph construction by propagating references to all
247 // java objects through graph.
248 if (!complete_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
249 java_objects_worklist, oop_fields_worklist)) {
250 // All objects escaped or hit time or iterations limits.
251 _collecting = false;
252 return false;
253 }
254
255 // 3. Adjust scalar_replaceable state of nonescaping objects and push
256 // scalar replaceable allocations on alloc_worklist for processing
257 // in split_unique_types().
258 int non_escaped_length = non_escaped_allocs_worklist.length();
259 for (int next = 0; next < non_escaped_length; next++) {
260 JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
261 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
262 Node* n = ptn->ideal_node();
263 if (n->is_Allocate()) {
264 n->as_Allocate()->_is_non_escaping = noescape;
265 }
266 if (noescape && ptn->scalar_replaceable()) {
267 adjust_scalar_replaceable_state(ptn);
268 if (ptn->scalar_replaceable()) {
269 alloc_worklist.append(ptn->ideal_node());
270 }
271 }
272 }
273
274 #ifdef ASSERT
275 if (VerifyConnectionGraph) {
276 // Verify that graph is complete - no new edges could be added or needed.
277 verify_connection_graph(ptnodes_worklist, non_escaped_allocs_worklist,
278 java_objects_worklist, addp_worklist);
279 }
280 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
281 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
282 null_obj->edge_count() == 0 &&
283 !null_obj->arraycopy_src() &&
284 !null_obj->arraycopy_dst(), "sanity");
285 #endif
286
287 _collecting = false;
288
289 } // TracePhase t3("connectionGraph")
290
291 // 4. Optimize ideal graph based on EA information.
292 bool has_non_escaping_obj = (non_escaped_allocs_worklist.length() > 0);
293 if (has_non_escaping_obj) {
294 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
295 }
296
297 #ifndef PRODUCT
298 if (PrintEscapeAnalysis) {
299 dump(ptnodes_worklist); // Dump ConnectionGraph
300 }
301 #endif
302
303 #ifdef ASSERT
304 if (VerifyConnectionGraph) {
305 int alloc_length = alloc_worklist.length();
306 for (int next = 0; next < alloc_length; ++next) {
307 Node* n = alloc_worklist.at(next);
308 PointsToNode* ptn = ptnode_adr(n->_idx);
309 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
310 }
311 }
312 #endif
313
314 // 5. Separate memory graph for scalar replaceable allcations.
315 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
316 if (has_scalar_replaceable_candidates &&
317 C->AliasLevel() >= 3 && EliminateAllocations) {
318 // Now use the escape information to create unique types for
319 // scalar replaceable objects.
320 split_unique_types(alloc_worklist, arraycopy_worklist, mergemem_worklist);
321 if (C->failing()) return false;
322 C->print_method(PHASE_AFTER_EA, 2);
323
324 #ifdef ASSERT
325 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
326 tty->print("=== No allocations eliminated for ");
327 C->method()->print_short_name();
328 if (!EliminateAllocations) {
329 tty->print(" since EliminateAllocations is off ===");
330 } else if(!has_scalar_replaceable_candidates) {
331 tty->print(" since there are no scalar replaceable candidates ===");
332 } else if(C->AliasLevel() < 3) {
333 tty->print(" since AliasLevel < 3 ===");
334 }
335 tty->cr();
336 #endif
337 }
338
339 // Annotate at safepoints if they have <= ArgEscape objects in their scope and at
340 // java calls if they pass ArgEscape objects as parameters.
341 if (has_non_escaping_obj &&
342 (C->env()->should_retain_local_variables() ||
343 C->env()->jvmti_can_get_owned_monitor_info() ||
344 C->env()->jvmti_can_walk_any_space() ||
345 DeoptimizeObjectsALot)) {
346 int sfn_length = sfn_worklist.length();
347 for (int next = 0; next < sfn_length; next++) {
348 SafePointNode* sfn = sfn_worklist.at(next);
349 sfn->set_has_ea_local_in_scope(has_ea_local_in_scope(sfn));
350 if (sfn->is_CallJava()) {
351 CallJavaNode* call = sfn->as_CallJava();
352 call->set_arg_escape(has_arg_escape(call));
353 }
354 }
355 }
356
357 return has_non_escaping_obj;
358 }
359
360 // Returns true if there is an object in the scope of sfn that does not escape globally.
361 bool ConnectionGraph::has_ea_local_in_scope(SafePointNode* sfn) {
362 Compile* C = _compile;
363 for (JVMState* jvms = sfn->jvms(); jvms != NULL; jvms = jvms->caller()) {
364 if (C->env()->should_retain_local_variables() || C->env()->jvmti_can_walk_any_space() ||
365 DeoptimizeObjectsALot) {
366 // Jvmti agents can access locals. Must provide info about local objects at runtime.
367 int num_locs = jvms->loc_size();
368 for (int idx = 0; idx < num_locs; idx++) {
369 Node* l = sfn->local(jvms, idx);
370 if (not_global_escape(l)) {
371 return true;
372 }
373 }
374 }
375 if (C->env()->jvmti_can_get_owned_monitor_info() ||
376 C->env()->jvmti_can_walk_any_space() || DeoptimizeObjectsALot) {
377 // Jvmti agents can read monitors. Must provide info about locked objects at runtime.
378 int num_mon = jvms->nof_monitors();
379 for (int idx = 0; idx < num_mon; idx++) {
380 Node* m = sfn->monitor_obj(jvms, idx);
381 if (m != NULL && not_global_escape(m)) {
382 return true;
383 }
384 }
385 }
386 }
387 return false;
388 }
389
390 // Returns true if at least one of the arguments to the call is an object
391 // that does not escape globally.
392 bool ConnectionGraph::has_arg_escape(CallJavaNode* call) {
393 if (call->method() != NULL) {
394 uint max_idx = TypeFunc::Parms + call->method()->arg_size();
395 for (uint idx = TypeFunc::Parms; idx < max_idx; idx++) {
396 Node* p = call->in(idx);
397 if (not_global_escape(p)) {
398 return true;
399 }
400 }
401 } else {
402 const char* name = call->as_CallStaticJava()->_name;
403 assert(name != NULL, "no name");
404 // no arg escapes through uncommon traps
405 if (strcmp(name, "uncommon_trap") != 0) {
406 // process_call_arguments() assumes that all arguments escape globally
407 const TypeTuple* d = call->tf()->domain();
408 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
409 const Type* at = d->field_at(i);
410 if (at->isa_oopptr() != NULL) {
411 return true;
412 }
413 }
414 }
415 }
416 return false;
417 }
418
419
420
421 // Utility function for nodes that load an object
422 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
423 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
424 // ThreadLocal has RawPtr type.
425 const Type* t = _igvn->type(n);
426 if (t->make_ptr() != NULL) {
427 Node* adr = n->in(MemNode::Address);
428 #ifdef ASSERT
429 if (!adr->is_AddP()) {
430 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
431 } else {
432 assert((ptnode_adr(adr->_idx) == NULL ||
433 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
434 }
435 #endif
436 add_local_var_and_edge(n, PointsToNode::NoEscape,
437 adr, delayed_worklist);
438 }
439 }
440
441 // Populate Connection Graph with PointsTo nodes and create simple
442 // connection graph edges.
443 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
444 assert(!_verify, "this method should not be called for verification");
445 PhaseGVN* igvn = _igvn;
446 uint n_idx = n->_idx;
447 PointsToNode* n_ptn = ptnode_adr(n_idx);
448 if (n_ptn != NULL) {
449 return; // No need to redefine PointsTo node during first iteration.
450 }
451 int opcode = n->Opcode();
452 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
453 if (gc_handled) {
454 return; // Ignore node if already handled by GC.
455 }
456
457 if (n->is_Call()) {
458 // Arguments to allocation and locking don't escape.
459 if (n->is_AbstractLock()) {
460 // Put Lock and Unlock nodes on IGVN worklist to process them during
461 // first IGVN optimization when escape information is still available.
462 record_for_optimizer(n);
463 } else if (n->is_Allocate()) {
464 add_call_node(n->as_Call());
465 record_for_optimizer(n);
466 } else {
467 if (n->is_CallStaticJava()) {
468 const char* name = n->as_CallStaticJava()->_name;
469 if (name != NULL && strcmp(name, "uncommon_trap") == 0) {
470 return; // Skip uncommon traps
471 }
472 }
473 // Don't mark as processed since call's arguments have to be processed.
474 delayed_worklist->push(n);
475 // Check if a call returns an object.
476 if ((n->as_Call()->returns_pointer() &&
477 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
478 (n->is_CallStaticJava() &&
479 n->as_CallStaticJava()->is_boxing_method())) {
480 add_call_node(n->as_Call());
481 }
482 }
483 return;
484 }
485 // Put this check here to process call arguments since some call nodes
486 // point to phantom_obj.
487 if (n_ptn == phantom_obj || n_ptn == null_obj) {
488 return; // Skip predefined nodes.
489 }
490 switch (opcode) {
491 case Op_AddP: {
492 Node* base = get_addp_base(n);
493 PointsToNode* ptn_base = ptnode_adr(base->_idx);
494 // Field nodes are created for all field types. They are used in
495 // adjust_scalar_replaceable_state() and split_unique_types().
496 // Note, non-oop fields will have only base edges in Connection
497 // Graph because such fields are not used for oop loads and stores.
498 int offset = address_offset(n, igvn);
499 add_field(n, PointsToNode::NoEscape, offset);
500 if (ptn_base == NULL) {
501 delayed_worklist->push(n); // Process it later.
502 } else {
503 n_ptn = ptnode_adr(n_idx);
504 add_base(n_ptn->as_Field(), ptn_base);
505 }
506 break;
507 }
508 case Op_CastX2P: {
509 map_ideal_node(n, phantom_obj);
510 break;
511 }
512 case Op_CastPP:
513 case Op_CheckCastPP:
514 case Op_EncodeP:
515 case Op_DecodeN:
516 case Op_EncodePKlass:
517 case Op_DecodeNKlass: {
518 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
519 break;
520 }
521 case Op_CMoveP: {
522 add_local_var(n, PointsToNode::NoEscape);
523 // Do not add edges during first iteration because some could be
524 // not defined yet.
525 delayed_worklist->push(n);
526 break;
527 }
528 case Op_ConP:
529 case Op_ConN:
530 case Op_ConNKlass: {
531 // assume all oop constants globally escape except for null
532 PointsToNode::EscapeState es;
533 const Type* t = igvn->type(n);
534 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
535 es = PointsToNode::NoEscape;
536 } else {
537 es = PointsToNode::GlobalEscape;
538 }
539 add_java_object(n, es);
540 break;
541 }
542 case Op_CreateEx: {
543 // assume that all exception objects globally escape
544 map_ideal_node(n, phantom_obj);
545 break;
546 }
547 case Op_LoadKlass:
548 case Op_LoadNKlass: {
549 // Unknown class is loaded
550 map_ideal_node(n, phantom_obj);
551 break;
552 }
553 case Op_LoadP:
554 case Op_LoadN:
555 case Op_LoadPLocked: {
556 add_objload_to_connection_graph(n, delayed_worklist);
557 break;
558 }
559 case Op_Parm: {
560 map_ideal_node(n, phantom_obj);
561 break;
562 }
563 case Op_PartialSubtypeCheck: {
564 // Produces Null or notNull and is used in only in CmpP so
565 // phantom_obj could be used.
566 map_ideal_node(n, phantom_obj); // Result is unknown
567 break;
568 }
569 case Op_Phi: {
570 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
571 // ThreadLocal has RawPtr type.
572 const Type* t = n->as_Phi()->type();
573 if (t->make_ptr() != NULL) {
574 add_local_var(n, PointsToNode::NoEscape);
575 // Do not add edges during first iteration because some could be
576 // not defined yet.
577 delayed_worklist->push(n);
578 }
579 break;
580 }
581 case Op_Proj: {
582 // we are only interested in the oop result projection from a call
583 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
584 n->in(0)->as_Call()->returns_pointer()) {
585 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), delayed_worklist);
586 }
587 break;
588 }
589 case Op_Rethrow: // Exception object escapes
590 case Op_Return: {
591 if (n->req() > TypeFunc::Parms &&
592 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
593 // Treat Return value as LocalVar with GlobalEscape escape state.
594 add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), delayed_worklist);
595 }
596 break;
597 }
598 case Op_CompareAndExchangeP:
599 case Op_CompareAndExchangeN:
600 case Op_GetAndSetP:
601 case Op_GetAndSetN: {
602 add_objload_to_connection_graph(n, delayed_worklist);
603 // fall-through
604 }
605 case Op_StoreP:
606 case Op_StoreN:
607 case Op_StoreNKlass:
608 case Op_StorePConditional:
609 case Op_WeakCompareAndSwapP:
610 case Op_WeakCompareAndSwapN:
611 case Op_CompareAndSwapP:
612 case Op_CompareAndSwapN: {
613 add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
614 break;
615 }
616 case Op_AryEq:
617 case Op_HasNegatives:
618 case Op_StrComp:
619 case Op_StrEquals:
620 case Op_StrIndexOf:
621 case Op_StrIndexOfChar:
622 case Op_StrInflatedCopy:
623 case Op_StrCompressedCopy:
624 case Op_EncodeISOArray: {
625 add_local_var(n, PointsToNode::ArgEscape);
626 delayed_worklist->push(n); // Process it later.
627 break;
628 }
629 case Op_ThreadLocal: {
630 add_java_object(n, PointsToNode::ArgEscape);
631 break;
632 }
633 default:
634 ; // Do nothing for nodes not related to EA.
635 }
636 return;
637 }
638
639 // Add final simple edges to graph.
640 void ConnectionGraph::add_final_edges(Node *n) {
641 PointsToNode* n_ptn = ptnode_adr(n->_idx);
642 #ifdef ASSERT
643 if (_verify && n_ptn->is_JavaObject())
644 return; // This method does not change graph for JavaObject.
645 #endif
646
647 if (n->is_Call()) {
648 process_call_arguments(n->as_Call());
649 return;
650 }
651 assert(n->is_Store() || n->is_LoadStore() ||
652 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
653 "node should be registered already");
654 int opcode = n->Opcode();
655 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
656 if (gc_handled) {
657 return; // Ignore node if already handled by GC.
658 }
659 switch (opcode) {
660 case Op_AddP: {
661 Node* base = get_addp_base(n);
662 PointsToNode* ptn_base = ptnode_adr(base->_idx);
663 assert(ptn_base != NULL, "field's base should be registered");
664 add_base(n_ptn->as_Field(), ptn_base);
665 break;
666 }
667 case Op_CastPP:
668 case Op_CheckCastPP:
669 case Op_EncodeP:
670 case Op_DecodeN:
671 case Op_EncodePKlass:
672 case Op_DecodeNKlass: {
673 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL);
674 break;
675 }
676 case Op_CMoveP: {
677 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
678 Node* in = n->in(i);
679 if (in == NULL) {
680 continue; // ignore NULL
681 }
682 Node* uncast_in = in->uncast();
683 if (uncast_in->is_top() || uncast_in == n) {
684 continue; // ignore top or inputs which go back this node
685 }
686 PointsToNode* ptn = ptnode_adr(in->_idx);
687 assert(ptn != NULL, "node should be registered");
688 add_edge(n_ptn, ptn);
689 }
690 break;
691 }
692 case Op_LoadP:
693 case Op_LoadN:
694 case Op_LoadPLocked: {
695 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
696 // ThreadLocal has RawPtr type.
697 assert(_igvn->type(n)->make_ptr() != NULL, "Unexpected node type");
698 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), NULL);
699 break;
700 }
701 case Op_Phi: {
702 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
703 // ThreadLocal has RawPtr type.
704 assert(n->as_Phi()->type()->make_ptr() != NULL, "Unexpected node type");
705 for (uint i = 1; i < n->req(); i++) {
706 Node* in = n->in(i);
707 if (in == NULL) {
708 continue; // ignore NULL
709 }
710 Node* uncast_in = in->uncast();
711 if (uncast_in->is_top() || uncast_in == n) {
712 continue; // ignore top or inputs which go back this node
713 }
714 PointsToNode* ptn = ptnode_adr(in->_idx);
715 assert(ptn != NULL, "node should be registered");
716 add_edge(n_ptn, ptn);
717 }
718 break;
719 }
720 case Op_Proj: {
721 // we are only interested in the oop result projection from a call
722 assert(n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
723 n->in(0)->as_Call()->returns_pointer(), "Unexpected node type");
724 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
725 break;
726 }
727 case Op_Rethrow: // Exception object escapes
728 case Op_Return: {
729 assert(n->req() > TypeFunc::Parms && _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr(),
730 "Unexpected node type");
731 // Treat Return value as LocalVar with GlobalEscape escape state.
732 add_local_var_and_edge(n, PointsToNode::GlobalEscape, n->in(TypeFunc::Parms), NULL);
733 break;
734 }
735 case Op_CompareAndExchangeP:
736 case Op_CompareAndExchangeN:
737 case Op_GetAndSetP:
738 case Op_GetAndSetN:{
739 assert(_igvn->type(n)->make_ptr() != NULL, "Unexpected node type");
740 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(MemNode::Address), NULL);
741 // fall-through
742 }
743 case Op_CompareAndSwapP:
744 case Op_CompareAndSwapN:
745 case Op_WeakCompareAndSwapP:
746 case Op_WeakCompareAndSwapN:
747 case Op_StoreP:
748 case Op_StoreN:
749 case Op_StoreNKlass:
750 case Op_StorePConditional:{
751 add_final_edges_unsafe_access(n, opcode);
752 break;
753 }
754 case Op_AryEq:
755 case Op_HasNegatives:
756 case Op_StrComp:
757 case Op_StrEquals:
758 case Op_StrIndexOf:
759 case Op_StrIndexOfChar:
760 case Op_StrInflatedCopy:
761 case Op_StrCompressedCopy:
762 case Op_EncodeISOArray: {
763 // char[]/byte[] arrays passed to string intrinsic do not escape but
764 // they are not scalar replaceable. Adjust escape state for them.
765 // Start from in(2) edge since in(1) is memory edge.
766 for (uint i = 2; i < n->req(); i++) {
767 Node* adr = n->in(i);
768 const Type* at = _igvn->type(adr);
769 if (!adr->is_top() && at->isa_ptr()) {
770 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
771 at->isa_ptr() != NULL, "expecting a pointer");
772 if (adr->is_AddP()) {
773 adr = get_addp_base(adr);
774 }
775 PointsToNode* ptn = ptnode_adr(adr->_idx);
776 assert(ptn != NULL, "node should be registered");
777 add_edge(n_ptn, ptn);
778 }
779 }
780 break;
781 }
782 default: {
783 // This method should be called only for EA specific nodes which may
784 // miss some edges when they were created.
785 #ifdef ASSERT
786 n->dump(1);
787 #endif
788 guarantee(false, "unknown node");
789 }
790 }
791 return;
792 }
793
794 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
795 Node* adr = n->in(MemNode::Address);
796 const Type* adr_type = _igvn->type(adr);
797 adr_type = adr_type->make_ptr();
798 if (adr_type == NULL) {
799 return; // skip dead nodes
800 }
801 if (adr_type->isa_oopptr()
802 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
803 && adr_type == TypeRawPtr::NOTNULL
804 && is_captured_store_address(adr))) {
805 delayed_worklist->push(n); // Process it later.
806 #ifdef ASSERT
807 assert (adr->is_AddP(), "expecting an AddP");
808 if (adr_type == TypeRawPtr::NOTNULL) {
809 // Verify a raw address for a store captured by Initialize node.
810 int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
811 assert(offs != Type::OffsetBot, "offset must be a constant");
812 }
813 #endif
814 } else {
815 // Ignore copy the displaced header to the BoxNode (OSR compilation).
816 if (adr->is_BoxLock()) {
817 return;
818 }
819 // Stored value escapes in unsafe access.
820 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
821 delayed_worklist->push(n); // Process unsafe access later.
822 return;
823 }
824 #ifdef ASSERT
825 n->dump(1);
826 assert(false, "not unsafe");
827 #endif
828 }
829 }
830
831 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
832 Node* adr = n->in(MemNode::Address);
833 const Type *adr_type = _igvn->type(adr);
834 adr_type = adr_type->make_ptr();
835 #ifdef ASSERT
836 if (adr_type == NULL) {
837 n->dump(1);
838 assert(adr_type != NULL, "dead node should not be on list");
839 return true;
840 }
841 #endif
842
843 if (adr_type->isa_oopptr()
844 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
845 && adr_type == TypeRawPtr::NOTNULL
846 && is_captured_store_address(adr))) {
847 // Point Address to Value
848 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
849 assert(adr_ptn != NULL &&
850 adr_ptn->as_Field()->is_oop(), "node should be registered");
851 Node* val = n->in(MemNode::ValueIn);
852 PointsToNode* ptn = ptnode_adr(val->_idx);
853 assert(ptn != NULL, "node should be registered");
854 add_edge(adr_ptn, ptn);
855 return true;
856 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
857 // Stored value escapes in unsafe access.
858 Node* val = n->in(MemNode::ValueIn);
859 PointsToNode* ptn = ptnode_adr(val->_idx);
860 assert(ptn != NULL, "node should be registered");
861 set_escape_state(ptn, PointsToNode::GlobalEscape);
862 // Add edge to object for unsafe access with offset.
863 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
864 assert(adr_ptn != NULL, "node should be registered");
865 if (adr_ptn->is_Field()) {
866 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
867 add_edge(adr_ptn, ptn);
868 }
869 return true;
870 }
871 #ifdef ASSERT
872 n->dump(1);
873 assert(false, "not unsafe");
874 #endif
875 return false;
876 }
877
878 void ConnectionGraph::add_call_node(CallNode* call) {
879 assert(call->returns_pointer(), "only for call which returns pointer");
880 uint call_idx = call->_idx;
881 if (call->is_Allocate()) {
882 Node* k = call->in(AllocateNode::KlassNode);
883 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
884 assert(kt != NULL, "TypeKlassPtr required.");
885 ciKlass* cik = kt->klass();
886 PointsToNode::EscapeState es = PointsToNode::NoEscape;
887 bool scalar_replaceable = true;
888 if (call->is_AllocateArray()) {
889 if (!cik->is_array_klass()) { // StressReflectiveCode
890 es = PointsToNode::GlobalEscape;
891 } else {
892 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
893 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
894 // Not scalar replaceable if the length is not constant or too big.
895 scalar_replaceable = false;
896 }
897 }
898 } else { // Allocate instance
899 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
900 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
901 !cik->is_instance_klass() || // StressReflectiveCode
902 !cik->as_instance_klass()->can_be_instantiated() ||
903 cik->as_instance_klass()->has_finalizer()) {
904 es = PointsToNode::GlobalEscape;
905 } else {
906 int nfields = cik->as_instance_klass()->nof_nonstatic_fields();
907 if (nfields > EliminateAllocationFieldsLimit) {
908 // Not scalar replaceable if there are too many fields.
909 scalar_replaceable = false;
910 }
911 }
912 }
913 add_java_object(call, es);
914 PointsToNode* ptn = ptnode_adr(call_idx);
915 if (!scalar_replaceable && ptn->scalar_replaceable()) {
916 ptn->set_scalar_replaceable(false);
917 }
918 } else if (call->is_CallStaticJava()) {
919 // Call nodes could be different types:
920 //
921 // 1. CallDynamicJavaNode (what happened during call is unknown):
922 //
923 // - mapped to GlobalEscape JavaObject node if oop is returned;
924 //
925 // - all oop arguments are escaping globally;
926 //
927 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
928 //
929 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
930 //
931 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
932 // - mapped to NoEscape JavaObject node if non-escaping object allocated
933 // during call is returned;
934 // - mapped to ArgEscape LocalVar node pointed to object arguments
935 // which are returned and does not escape during call;
936 //
937 // - oop arguments escaping status is defined by bytecode analysis;
938 //
939 // For a static call, we know exactly what method is being called.
940 // Use bytecode estimator to record whether the call's return value escapes.
941 ciMethod* meth = call->as_CallJava()->method();
942 if (meth == NULL) {
943 const char* name = call->as_CallStaticJava()->_name;
944 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
945 // Returns a newly allocated non-escaped object.
946 add_java_object(call, PointsToNode::NoEscape);
947 ptnode_adr(call_idx)->set_scalar_replaceable(false);
948 } else if (meth->is_boxing_method()) {
949 // Returns boxing object
950 PointsToNode::EscapeState es;
951 vmIntrinsics::ID intr = meth->intrinsic_id();
952 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
953 // It does not escape if object is always allocated.
954 es = PointsToNode::NoEscape;
955 } else {
956 // It escapes globally if object could be loaded from cache.
957 es = PointsToNode::GlobalEscape;
958 }
959 add_java_object(call, es);
960 } else {
961 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
962 call_analyzer->copy_dependencies(_compile->dependencies());
963 if (call_analyzer->is_return_allocated()) {
964 // Returns a newly allocated non-escaped object, simply
965 // update dependency information.
966 // Mark it as NoEscape so that objects referenced by
967 // it's fields will be marked as NoEscape at least.
968 add_java_object(call, PointsToNode::NoEscape);
969 ptnode_adr(call_idx)->set_scalar_replaceable(false);
970 } else {
971 // Determine whether any arguments are returned.
972 const TypeTuple* d = call->tf()->domain();
973 bool ret_arg = false;
974 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
975 if (d->field_at(i)->isa_ptr() != NULL &&
976 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
977 ret_arg = true;
978 break;
979 }
980 }
981 if (ret_arg) {
982 add_local_var(call, PointsToNode::ArgEscape);
983 } else {
984 // Returns unknown object.
985 map_ideal_node(call, phantom_obj);
986 }
987 }
988 }
989 } else {
990 // An other type of call, assume the worst case:
991 // returned value is unknown and globally escapes.
992 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
993 map_ideal_node(call, phantom_obj);
994 }
995 }
996
997 void ConnectionGraph::process_call_arguments(CallNode *call) {
998 bool is_arraycopy = false;
999 switch (call->Opcode()) {
1000 #ifdef ASSERT
1001 case Op_Allocate:
1002 case Op_AllocateArray:
1003 case Op_Lock:
1004 case Op_Unlock:
1005 assert(false, "should be done already");
1006 break;
1007 #endif
1008 case Op_ArrayCopy:
1009 case Op_CallLeafNoFP:
1010 // Most array copies are ArrayCopy nodes at this point but there
1011 // are still a few direct calls to the copy subroutines (See
1012 // PhaseStringOpts::copy_string())
1013 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
1014 call->as_CallLeaf()->is_call_to_arraycopystub();
1015 // fall through
1016 case Op_CallLeafVector:
1017 case Op_CallLeaf: {
1018 // Stub calls, objects do not escape but they are not scale replaceable.
1019 // Adjust escape state for outgoing arguments.
1020 const TypeTuple * d = call->tf()->domain();
1021 bool src_has_oops = false;
1022 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1023 const Type* at = d->field_at(i);
1024 Node *arg = call->in(i);
1025 if (arg == NULL) {
1026 continue;
1027 }
1028 const Type *aat = _igvn->type(arg);
1029 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr()) {
1030 continue;
1031 }
1032 if (arg->is_AddP()) {
1033 //
1034 // The inline_native_clone() case when the arraycopy stub is called
1035 // after the allocation before Initialize and CheckCastPP nodes.
1036 // Or normal arraycopy for object arrays case.
1037 //
1038 // Set AddP's base (Allocate) as not scalar replaceable since
1039 // pointer to the base (with offset) is passed as argument.
1040 //
1041 arg = get_addp_base(arg);
1042 }
1043 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1044 assert(arg_ptn != NULL, "should be registered");
1045 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
1046 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
1047 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1048 aat->isa_ptr() != NULL, "expecting an Ptr");
1049 bool arg_has_oops = aat->isa_oopptr() &&
1050 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
1051 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
1052 if (i == TypeFunc::Parms) {
1053 src_has_oops = arg_has_oops;
1054 }
1055 //
1056 // src or dst could be j.l.Object when other is basic type array:
1057 //
1058 // arraycopy(char[],0,Object*,0,size);
1059 // arraycopy(Object*,0,char[],0,size);
1060 //
1061 // Don't add edges in such cases.
1062 //
1063 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
1064 arg_has_oops && (i > TypeFunc::Parms);
1065 #ifdef ASSERT
1066 if (!(is_arraycopy ||
1067 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
1068 (call->as_CallLeaf()->_name != NULL &&
1069 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
1070 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
1071 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
1072 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
1073 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
1074 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
1075 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
1076 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
1077 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
1078 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
1079 strcmp(call->as_CallLeaf()->_name, "galoisCounterMode_AESCrypt") == 0 ||
1080 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
1081 strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
1082 strcmp(call->as_CallLeaf()->_name, "decodeBlock") == 0 ||
1083 strcmp(call->as_CallLeaf()->_name, "md5_implCompress") == 0 ||
1084 strcmp(call->as_CallLeaf()->_name, "md5_implCompressMB") == 0 ||
1085 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
1086 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
1087 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
1088 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
1089 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1090 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1091 strcmp(call->as_CallLeaf()->_name, "sha3_implCompress") == 0 ||
1092 strcmp(call->as_CallLeaf()->_name, "sha3_implCompressMB") == 0 ||
1093 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1094 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1095 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1096 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1097 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1098 strcmp(call->as_CallLeaf()->_name, "bigIntegerRightShiftWorker") == 0 ||
1099 strcmp(call->as_CallLeaf()->_name, "bigIntegerLeftShiftWorker") == 0 ||
1100 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0 ||
1101 strcmp(call->as_CallLeaf()->_name, "get_class_id_intrinsic") == 0)
1102 ))) {
1103 call->dump();
1104 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1105 }
1106 #endif
1107 // Always process arraycopy's destination object since
1108 // we need to add all possible edges to references in
1109 // source object.
1110 if (arg_esc >= PointsToNode::ArgEscape &&
1111 !arg_is_arraycopy_dest) {
1112 continue;
1113 }
1114 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1115 if (call->is_ArrayCopy()) {
1116 ArrayCopyNode* ac = call->as_ArrayCopy();
1117 if (ac->is_clonebasic() ||
1118 ac->is_arraycopy_validated() ||
1119 ac->is_copyof_validated() ||
1120 ac->is_copyofrange_validated()) {
1121 es = PointsToNode::NoEscape;
1122 }
1123 }
1124 set_escape_state(arg_ptn, es);
1125 if (arg_is_arraycopy_dest) {
1126 Node* src = call->in(TypeFunc::Parms);
1127 if (src->is_AddP()) {
1128 src = get_addp_base(src);
1129 }
1130 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1131 assert(src_ptn != NULL, "should be registered");
1132 if (arg_ptn != src_ptn) {
1133 // Special arraycopy edge:
1134 // A destination object's field can't have the source object
1135 // as base since objects escape states are not related.
1136 // Only escape state of destination object's fields affects
1137 // escape state of fields in source object.
1138 add_arraycopy(call, es, src_ptn, arg_ptn);
1139 }
1140 }
1141 }
1142 }
1143 break;
1144 }
1145 case Op_CallStaticJava: {
1146 // For a static call, we know exactly what method is being called.
1147 // Use bytecode estimator to record the call's escape affects
1148 #ifdef ASSERT
1149 const char* name = call->as_CallStaticJava()->_name;
1150 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1151 #endif
1152 ciMethod* meth = call->as_CallJava()->method();
1153 if ((meth != NULL) && meth->is_boxing_method()) {
1154 break; // Boxing methods do not modify any oops.
1155 }
1156 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1157 // fall-through if not a Java method or no analyzer information
1158 if (call_analyzer != NULL) {
1159 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1160 const TypeTuple* d = call->tf()->domain();
1161 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1162 const Type* at = d->field_at(i);
1163 int k = i - TypeFunc::Parms;
1164 Node* arg = call->in(i);
1165 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1166 if (at->isa_ptr() != NULL &&
1167 call_analyzer->is_arg_returned(k)) {
1168 // The call returns arguments.
1169 if (call_ptn != NULL) { // Is call's result used?
1170 assert(call_ptn->is_LocalVar(), "node should be registered");
1171 assert(arg_ptn != NULL, "node should be registered");
1172 add_edge(call_ptn, arg_ptn);
1173 }
1174 }
1175 if (at->isa_oopptr() != NULL &&
1176 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1177 if (!call_analyzer->is_arg_stack(k)) {
1178 // The argument global escapes
1179 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1180 } else {
1181 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1182 if (!call_analyzer->is_arg_local(k)) {
1183 // The argument itself doesn't escape, but any fields might
1184 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1185 }
1186 }
1187 }
1188 }
1189 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1190 // The call returns arguments.
1191 assert(call_ptn->edge_count() > 0, "sanity");
1192 if (!call_analyzer->is_return_local()) {
1193 // Returns also unknown object.
1194 add_edge(call_ptn, phantom_obj);
1195 }
1196 }
1197 break;
1198 }
1199 }
1200 default: {
1201 // Fall-through here if not a Java method or no analyzer information
1202 // or some other type of call, assume the worst case: all arguments
1203 // globally escape.
1204 const TypeTuple* d = call->tf()->domain();
1205 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1206 const Type* at = d->field_at(i);
1207 if (at->isa_oopptr() != NULL) {
1208 Node* arg = call->in(i);
1209 if (arg->is_AddP()) {
1210 arg = get_addp_base(arg);
1211 }
1212 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1213 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1214 }
1215 }
1216 }
1217 }
1218 }
1219
1220
1221 // Finish Graph construction.
1222 bool ConnectionGraph::complete_connection_graph(
1223 GrowableArray<PointsToNode*>& ptnodes_worklist,
1224 GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
1225 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1226 GrowableArray<FieldNode*>& oop_fields_worklist) {
1227 // Normally only 1-3 passes needed to build Connection Graph depending
1228 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1229 // Set limit to 20 to catch situation when something did go wrong and
1230 // bailout Escape Analysis.
1231 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1232 #define GRAPH_BUILD_ITER_LIMIT 20
1233
1234 // Propagate GlobalEscape and ArgEscape escape states and check that
1235 // we still have non-escaping objects. The method pushs on _worklist
1236 // Field nodes which reference phantom_object.
1237 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
1238 return false; // Nothing to do.
1239 }
1240 // Now propagate references to all JavaObject nodes.
1241 int java_objects_length = java_objects_worklist.length();
1242 elapsedTimer build_time;
1243 build_time.start();
1244 elapsedTimer time;
1245 bool timeout = false;
1246 int new_edges = 1;
1247 int iterations = 0;
1248 do {
1249 while ((new_edges > 0) &&
1250 (iterations++ < GRAPH_BUILD_ITER_LIMIT)) {
1251 double start_time = time.seconds();
1252 time.start();
1253 new_edges = 0;
1254 // Propagate references to phantom_object for nodes pushed on _worklist
1255 // by find_non_escaped_objects() and find_field_value().
1256 new_edges += add_java_object_edges(phantom_obj, false);
1257 for (int next = 0; next < java_objects_length; ++next) {
1258 JavaObjectNode* ptn = java_objects_worklist.at(next);
1259 new_edges += add_java_object_edges(ptn, true);
1260
1261 #define SAMPLE_SIZE 4
1262 if ((next % SAMPLE_SIZE) == 0) {
1263 // Each 4 iterations calculate how much time it will take
1264 // to complete graph construction.
1265 time.stop();
1266 // Poll for requests from shutdown mechanism to quiesce compiler
1267 // because Connection graph construction may take long time.
1268 CompileBroker::maybe_block();
1269 double stop_time = time.seconds();
1270 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1271 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1272 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1273 timeout = true;
1274 break; // Timeout
1275 }
1276 start_time = stop_time;
1277 time.start();
1278 }
1279 #undef SAMPLE_SIZE
1280
1281 }
1282 if (timeout) break;
1283 if (new_edges > 0) {
1284 // Update escape states on each iteration if graph was updated.
1285 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist)) {
1286 return false; // Nothing to do.
1287 }
1288 }
1289 time.stop();
1290 if (time.seconds() >= EscapeAnalysisTimeout) {
1291 timeout = true;
1292 break;
1293 }
1294 }
1295 if ((iterations < GRAPH_BUILD_ITER_LIMIT) && !timeout) {
1296 time.start();
1297 // Find fields which have unknown value.
1298 int fields_length = oop_fields_worklist.length();
1299 for (int next = 0; next < fields_length; next++) {
1300 FieldNode* field = oop_fields_worklist.at(next);
1301 if (field->edge_count() == 0) {
1302 new_edges += find_field_value(field);
1303 // This code may added new edges to phantom_object.
1304 // Need an other cycle to propagate references to phantom_object.
1305 }
1306 }
1307 time.stop();
1308 if (time.seconds() >= EscapeAnalysisTimeout) {
1309 timeout = true;
1310 break;
1311 }
1312 } else {
1313 new_edges = 0; // Bailout
1314 }
1315 } while (new_edges > 0);
1316
1317 build_time.stop();
1318 _build_time = build_time.seconds();
1319 _build_iterations = iterations;
1320
1321 // Bailout if passed limits.
1322 if ((iterations >= GRAPH_BUILD_ITER_LIMIT) || timeout) {
1323 Compile* C = _compile;
1324 if (C->log() != NULL) {
1325 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1326 C->log()->text("%s", timeout ? "time" : "iterations");
1327 C->log()->end_elem(" limit'");
1328 }
1329 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1330 _build_time, _build_iterations, nodes_size(), ptnodes_worklist.length());
1331 // Possible infinite build_connection_graph loop,
1332 // bailout (no changes to ideal graph were made).
1333 return false;
1334 }
1335 #ifdef ASSERT
1336 if (Verbose && PrintEscapeAnalysis) {
1337 tty->print_cr("EA: %d iterations and %f sec to build connection graph with %d nodes and worklist size %d",
1338 _build_iterations, _build_time, nodes_size(), ptnodes_worklist.length());
1339 }
1340 #endif
1341
1342 #undef GRAPH_BUILD_ITER_LIMIT
1343
1344 // Find fields initialized by NULL for non-escaping Allocations.
1345 int non_escaped_length = non_escaped_allocs_worklist.length();
1346 for (int next = 0; next < non_escaped_length; next++) {
1347 JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
1348 PointsToNode::EscapeState es = ptn->escape_state();
1349 assert(es <= PointsToNode::ArgEscape, "sanity");
1350 if (es == PointsToNode::NoEscape) {
1351 if (find_init_values_null(ptn, _igvn) > 0) {
1352 // Adding references to NULL object does not change escape states
1353 // since it does not escape. Also no fields are added to NULL object.
1354 add_java_object_edges(null_obj, false);
1355 }
1356 }
1357 Node* n = ptn->ideal_node();
1358 if (n->is_Allocate()) {
1359 // The object allocated by this Allocate node will never be
1360 // seen by an other thread. Mark it so that when it is
1361 // expanded no MemBarStoreStore is added.
1362 InitializeNode* ini = n->as_Allocate()->initialization();
1363 if (ini != NULL)
1364 ini->set_does_not_escape();
1365 }
1366 }
1367 return true; // Finished graph construction.
1368 }
1369
1370 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1371 // and check that we still have non-escaping java objects.
1372 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1373 GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist) {
1374 GrowableArray<PointsToNode*> escape_worklist;
1375 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1376 int ptnodes_length = ptnodes_worklist.length();
1377 for (int next = 0; next < ptnodes_length; ++next) {
1378 PointsToNode* ptn = ptnodes_worklist.at(next);
1379 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1380 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1381 escape_worklist.push(ptn);
1382 }
1383 }
1384 // Set escape states to referenced nodes (edges list).
1385 while (escape_worklist.length() > 0) {
1386 PointsToNode* ptn = escape_worklist.pop();
1387 PointsToNode::EscapeState es = ptn->escape_state();
1388 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1389 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1390 es >= PointsToNode::ArgEscape) {
1391 // GlobalEscape or ArgEscape state of field means it has unknown value.
1392 if (add_edge(ptn, phantom_obj)) {
1393 // New edge was added
1394 add_field_uses_to_worklist(ptn->as_Field());
1395 }
1396 }
1397 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1398 PointsToNode* e = i.get();
1399 if (e->is_Arraycopy()) {
1400 assert(ptn->arraycopy_dst(), "sanity");
1401 // Propagate only fields escape state through arraycopy edge.
1402 if (e->fields_escape_state() < field_es) {
1403 set_fields_escape_state(e, field_es);
1404 escape_worklist.push(e);
1405 }
1406 } else if (es >= field_es) {
1407 // fields_escape_state is also set to 'es' if it is less than 'es'.
1408 if (e->escape_state() < es) {
1409 set_escape_state(e, es);
1410 escape_worklist.push(e);
1411 }
1412 } else {
1413 // Propagate field escape state.
1414 bool es_changed = false;
1415 if (e->fields_escape_state() < field_es) {
1416 set_fields_escape_state(e, field_es);
1417 es_changed = true;
1418 }
1419 if ((e->escape_state() < field_es) &&
1420 e->is_Field() && ptn->is_JavaObject() &&
1421 e->as_Field()->is_oop()) {
1422 // Change escape state of referenced fields.
1423 set_escape_state(e, field_es);
1424 es_changed = true;
1425 } else if (e->escape_state() < es) {
1426 set_escape_state(e, es);
1427 es_changed = true;
1428 }
1429 if (es_changed) {
1430 escape_worklist.push(e);
1431 }
1432 }
1433 }
1434 }
1435 // Remove escaped objects from non_escaped list.
1436 for (int next = non_escaped_allocs_worklist.length()-1; next >= 0 ; --next) {
1437 JavaObjectNode* ptn = non_escaped_allocs_worklist.at(next);
1438 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1439 non_escaped_allocs_worklist.delete_at(next);
1440 }
1441 if (ptn->escape_state() == PointsToNode::NoEscape) {
1442 // Find fields in non-escaped allocations which have unknown value.
1443 find_init_values_phantom(ptn);
1444 }
1445 }
1446 return (non_escaped_allocs_worklist.length() > 0);
1447 }
1448
1449 // Add all references to JavaObject node by walking over all uses.
1450 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1451 int new_edges = 0;
1452 if (populate_worklist) {
1453 // Populate _worklist by uses of jobj's uses.
1454 for (UseIterator i(jobj); i.has_next(); i.next()) {
1455 PointsToNode* use = i.get();
1456 if (use->is_Arraycopy()) {
1457 continue;
1458 }
1459 add_uses_to_worklist(use);
1460 if (use->is_Field() && use->as_Field()->is_oop()) {
1461 // Put on worklist all field's uses (loads) and
1462 // related field nodes (same base and offset).
1463 add_field_uses_to_worklist(use->as_Field());
1464 }
1465 }
1466 }
1467 for (int l = 0; l < _worklist.length(); l++) {
1468 PointsToNode* use = _worklist.at(l);
1469 if (PointsToNode::is_base_use(use)) {
1470 // Add reference from jobj to field and from field to jobj (field's base).
1471 use = PointsToNode::get_use_node(use)->as_Field();
1472 if (add_base(use->as_Field(), jobj)) {
1473 new_edges++;
1474 }
1475 continue;
1476 }
1477 assert(!use->is_JavaObject(), "sanity");
1478 if (use->is_Arraycopy()) {
1479 if (jobj == null_obj) { // NULL object does not have field edges
1480 continue;
1481 }
1482 // Added edge from Arraycopy node to arraycopy's source java object
1483 if (add_edge(use, jobj)) {
1484 jobj->set_arraycopy_src();
1485 new_edges++;
1486 }
1487 // and stop here.
1488 continue;
1489 }
1490 if (!add_edge(use, jobj)) {
1491 continue; // No new edge added, there was such edge already.
1492 }
1493 new_edges++;
1494 if (use->is_LocalVar()) {
1495 add_uses_to_worklist(use);
1496 if (use->arraycopy_dst()) {
1497 for (EdgeIterator i(use); i.has_next(); i.next()) {
1498 PointsToNode* e = i.get();
1499 if (e->is_Arraycopy()) {
1500 if (jobj == null_obj) { // NULL object does not have field edges
1501 continue;
1502 }
1503 // Add edge from arraycopy's destination java object to Arraycopy node.
1504 if (add_edge(jobj, e)) {
1505 new_edges++;
1506 jobj->set_arraycopy_dst();
1507 }
1508 }
1509 }
1510 }
1511 } else {
1512 // Added new edge to stored in field values.
1513 // Put on worklist all field's uses (loads) and
1514 // related field nodes (same base and offset).
1515 add_field_uses_to_worklist(use->as_Field());
1516 }
1517 }
1518 _worklist.clear();
1519 _in_worklist.reset();
1520 return new_edges;
1521 }
1522
1523 // Put on worklist all related field nodes.
1524 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1525 assert(field->is_oop(), "sanity");
1526 int offset = field->offset();
1527 add_uses_to_worklist(field);
1528 // Loop over all bases of this field and push on worklist Field nodes
1529 // with the same offset and base (since they may reference the same field).
1530 for (BaseIterator i(field); i.has_next(); i.next()) {
1531 PointsToNode* base = i.get();
1532 add_fields_to_worklist(field, base);
1533 // Check if the base was source object of arraycopy and go over arraycopy's
1534 // destination objects since values stored to a field of source object are
1535 // accessable by uses (loads) of fields of destination objects.
1536 if (base->arraycopy_src()) {
1537 for (UseIterator j(base); j.has_next(); j.next()) {
1538 PointsToNode* arycp = j.get();
1539 if (arycp->is_Arraycopy()) {
1540 for (UseIterator k(arycp); k.has_next(); k.next()) {
1541 PointsToNode* abase = k.get();
1542 if (abase->arraycopy_dst() && abase != base) {
1543 // Look for the same arraycopy reference.
1544 add_fields_to_worklist(field, abase);
1545 }
1546 }
1547 }
1548 }
1549 }
1550 }
1551 }
1552
1553 // Put on worklist all related field nodes.
1554 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1555 int offset = field->offset();
1556 if (base->is_LocalVar()) {
1557 for (UseIterator j(base); j.has_next(); j.next()) {
1558 PointsToNode* f = j.get();
1559 if (PointsToNode::is_base_use(f)) { // Field
1560 f = PointsToNode::get_use_node(f);
1561 if (f == field || !f->as_Field()->is_oop()) {
1562 continue;
1563 }
1564 int offs = f->as_Field()->offset();
1565 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1566 add_to_worklist(f);
1567 }
1568 }
1569 }
1570 } else {
1571 assert(base->is_JavaObject(), "sanity");
1572 if (// Skip phantom_object since it is only used to indicate that
1573 // this field's content globally escapes.
1574 (base != phantom_obj) &&
1575 // NULL object node does not have fields.
1576 (base != null_obj)) {
1577 for (EdgeIterator i(base); i.has_next(); i.next()) {
1578 PointsToNode* f = i.get();
1579 // Skip arraycopy edge since store to destination object field
1580 // does not update value in source object field.
1581 if (f->is_Arraycopy()) {
1582 assert(base->arraycopy_dst(), "sanity");
1583 continue;
1584 }
1585 if (f == field || !f->as_Field()->is_oop()) {
1586 continue;
1587 }
1588 int offs = f->as_Field()->offset();
1589 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1590 add_to_worklist(f);
1591 }
1592 }
1593 }
1594 }
1595 }
1596
1597 // Find fields which have unknown value.
1598 int ConnectionGraph::find_field_value(FieldNode* field) {
1599 // Escaped fields should have init value already.
1600 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1601 int new_edges = 0;
1602 for (BaseIterator i(field); i.has_next(); i.next()) {
1603 PointsToNode* base = i.get();
1604 if (base->is_JavaObject()) {
1605 // Skip Allocate's fields which will be processed later.
1606 if (base->ideal_node()->is_Allocate()) {
1607 return 0;
1608 }
1609 assert(base == null_obj, "only NULL ptr base expected here");
1610 }
1611 }
1612 if (add_edge(field, phantom_obj)) {
1613 // New edge was added
1614 new_edges++;
1615 add_field_uses_to_worklist(field);
1616 }
1617 return new_edges;
1618 }
1619
1620 // Find fields initializing values for allocations.
1621 int ConnectionGraph::find_init_values_phantom(JavaObjectNode* pta) {
1622 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1623 Node* alloc = pta->ideal_node();
1624
1625 // Do nothing for Allocate nodes since its fields values are
1626 // "known" unless they are initialized by arraycopy/clone.
1627 if (alloc->is_Allocate() && !pta->arraycopy_dst()) {
1628 return 0;
1629 }
1630 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1631 #ifdef ASSERT
1632 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1633 const char* name = alloc->as_CallStaticJava()->_name;
1634 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1635 }
1636 #endif
1637 // Non-escaped allocation returned from Java or runtime call have unknown values in fields.
1638 int new_edges = 0;
1639 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1640 PointsToNode* field = i.get();
1641 if (field->is_Field() && field->as_Field()->is_oop()) {
1642 if (add_edge(field, phantom_obj)) {
1643 // New edge was added
1644 new_edges++;
1645 add_field_uses_to_worklist(field->as_Field());
1646 }
1647 }
1648 }
1649 return new_edges;
1650 }
1651
1652 // Find fields initializing values for allocations.
1653 int ConnectionGraph::find_init_values_null(JavaObjectNode* pta, PhaseTransform* phase) {
1654 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1655 Node* alloc = pta->ideal_node();
1656 // Do nothing for Call nodes since its fields values are unknown.
1657 if (!alloc->is_Allocate()) {
1658 return 0;
1659 }
1660 InitializeNode* ini = alloc->as_Allocate()->initialization();
1661 bool visited_bottom_offset = false;
1662 GrowableArray<int> offsets_worklist;
1663 int new_edges = 0;
1664
1665 // Check if an oop field's initializing value is recorded and add
1666 // a corresponding NULL if field's value if it is not recorded.
1667 // Connection Graph does not record a default initialization by NULL
1668 // captured by Initialize node.
1669 //
1670 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1671 PointsToNode* field = i.get(); // Field (AddP)
1672 if (!field->is_Field() || !field->as_Field()->is_oop()) {
1673 continue; // Not oop field
1674 }
1675 int offset = field->as_Field()->offset();
1676 if (offset == Type::OffsetBot) {
1677 if (!visited_bottom_offset) {
1678 // OffsetBot is used to reference array's element,
1679 // always add reference to NULL to all Field nodes since we don't
1680 // known which element is referenced.
1681 if (add_edge(field, null_obj)) {
1682 // New edge was added
1683 new_edges++;
1684 add_field_uses_to_worklist(field->as_Field());
1685 visited_bottom_offset = true;
1686 }
1687 }
1688 } else {
1689 // Check only oop fields.
1690 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1691 if (adr_type->isa_rawptr()) {
1692 #ifdef ASSERT
1693 // Raw pointers are used for initializing stores so skip it
1694 // since it should be recorded already
1695 Node* base = get_addp_base(field->ideal_node());
1696 assert(adr_type->isa_rawptr() && is_captured_store_address(field->ideal_node()), "unexpected pointer type");
1697 #endif
1698 continue;
1699 }
1700 if (!offsets_worklist.contains(offset)) {
1701 offsets_worklist.append(offset);
1702 Node* value = NULL;
1703 if (ini != NULL) {
1704 // StoreP::memory_type() == T_ADDRESS
1705 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1706 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1707 // Make sure initializing store has the same type as this AddP.
1708 // This AddP may reference non existing field because it is on a
1709 // dead branch of bimorphic call which is not eliminated yet.
1710 if (store != NULL && store->is_Store() &&
1711 store->as_Store()->memory_type() == ft) {
1712 value = store->in(MemNode::ValueIn);
1713 #ifdef ASSERT
1714 if (VerifyConnectionGraph) {
1715 // Verify that AddP already points to all objects the value points to.
1716 PointsToNode* val = ptnode_adr(value->_idx);
1717 assert((val != NULL), "should be processed already");
1718 PointsToNode* missed_obj = NULL;
1719 if (val->is_JavaObject()) {
1720 if (!field->points_to(val->as_JavaObject())) {
1721 missed_obj = val;
1722 }
1723 } else {
1724 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1725 tty->print_cr("----------init store has invalid value -----");
1726 store->dump();
1727 val->dump();
1728 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1729 }
1730 for (EdgeIterator j(val); j.has_next(); j.next()) {
1731 PointsToNode* obj = j.get();
1732 if (obj->is_JavaObject()) {
1733 if (!field->points_to(obj->as_JavaObject())) {
1734 missed_obj = obj;
1735 break;
1736 }
1737 }
1738 }
1739 }
1740 if (missed_obj != NULL) {
1741 tty->print_cr("----------field---------------------------------");
1742 field->dump();
1743 tty->print_cr("----------missed referernce to object-----------");
1744 missed_obj->dump();
1745 tty->print_cr("----------object referernced by init store -----");
1746 store->dump();
1747 val->dump();
1748 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1749 }
1750 }
1751 #endif
1752 } else {
1753 // There could be initializing stores which follow allocation.
1754 // For example, a volatile field store is not collected
1755 // by Initialize node.
1756 //
1757 // Need to check for dependent loads to separate such stores from
1758 // stores which follow loads. For now, add initial value NULL so
1759 // that compare pointers optimization works correctly.
1760 }
1761 }
1762 if (value == NULL) {
1763 // A field's initializing value was not recorded. Add NULL.
1764 if (add_edge(field, null_obj)) {
1765 // New edge was added
1766 new_edges++;
1767 add_field_uses_to_worklist(field->as_Field());
1768 }
1769 }
1770 }
1771 }
1772 }
1773 return new_edges;
1774 }
1775
1776 // Adjust scalar_replaceable state after Connection Graph is built.
1777 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1778 // Search for non-escaping objects which are not scalar replaceable
1779 // and mark them to propagate the state to referenced objects.
1780
1781 for (UseIterator i(jobj); i.has_next(); i.next()) {
1782 PointsToNode* use = i.get();
1783 if (use->is_Arraycopy()) {
1784 continue;
1785 }
1786 if (use->is_Field()) {
1787 FieldNode* field = use->as_Field();
1788 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1789 // 1. An object is not scalar replaceable if the field into which it is
1790 // stored has unknown offset (stored into unknown element of an array).
1791 if (field->offset() == Type::OffsetBot) {
1792 jobj->set_scalar_replaceable(false);
1793 return;
1794 }
1795 // 2. An object is not scalar replaceable if the field into which it is
1796 // stored has multiple bases one of which is null.
1797 if (field->base_count() > 1) {
1798 for (BaseIterator i(field); i.has_next(); i.next()) {
1799 PointsToNode* base = i.get();
1800 if (base == null_obj) {
1801 jobj->set_scalar_replaceable(false);
1802 return;
1803 }
1804 }
1805 }
1806 }
1807 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1808 // 3. An object is not scalar replaceable if it is merged with other objects.
1809 for (EdgeIterator j(use); j.has_next(); j.next()) {
1810 PointsToNode* ptn = j.get();
1811 if (ptn->is_JavaObject() && ptn != jobj) {
1812 // Mark all objects.
1813 jobj->set_scalar_replaceable(false);
1814 ptn->set_scalar_replaceable(false);
1815 }
1816 }
1817 if (!jobj->scalar_replaceable()) {
1818 return;
1819 }
1820 }
1821
1822 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1823 if (j.get()->is_Arraycopy()) {
1824 continue;
1825 }
1826
1827 // Non-escaping object node should point only to field nodes.
1828 FieldNode* field = j.get()->as_Field();
1829 int offset = field->as_Field()->offset();
1830
1831 // 4. An object is not scalar replaceable if it has a field with unknown
1832 // offset (array's element is accessed in loop).
1833 if (offset == Type::OffsetBot) {
1834 jobj->set_scalar_replaceable(false);
1835 return;
1836 }
1837 // 5. Currently an object is not scalar replaceable if a LoadStore node
1838 // access its field since the field value is unknown after it.
1839 //
1840 Node* n = field->ideal_node();
1841
1842 // Test for an unsafe access that was parsed as maybe off heap
1843 // (with a CheckCastPP to raw memory).
1844 assert(n->is_AddP(), "expect an address computation");
1845 if (n->in(AddPNode::Base)->is_top() &&
1846 n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
1847 assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
1848 assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
1849 jobj->set_scalar_replaceable(false);
1850 return;
1851 }
1852
1853 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1854 Node* u = n->fast_out(i);
1855 if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
1856 jobj->set_scalar_replaceable(false);
1857 return;
1858 }
1859 }
1860
1861 // 6. Or the address may point to more then one object. This may produce
1862 // the false positive result (set not scalar replaceable)
1863 // since the flow-insensitive escape analysis can't separate
1864 // the case when stores overwrite the field's value from the case
1865 // when stores happened on different control branches.
1866 //
1867 // Note: it will disable scalar replacement in some cases:
1868 //
1869 // Point p[] = new Point[1];
1870 // p[0] = new Point(); // Will be not scalar replaced
1871 //
1872 // but it will save us from incorrect optimizations in next cases:
1873 //
1874 // Point p[] = new Point[1];
1875 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1876 //
1877 if (field->base_count() > 1) {
1878 for (BaseIterator i(field); i.has_next(); i.next()) {
1879 PointsToNode* base = i.get();
1880 // Don't take into account LocalVar nodes which
1881 // may point to only one object which should be also
1882 // this field's base by now.
1883 if (base->is_JavaObject() && base != jobj) {
1884 // Mark all bases.
1885 jobj->set_scalar_replaceable(false);
1886 base->set_scalar_replaceable(false);
1887 }
1888 }
1889 }
1890 }
1891 }
1892
1893 #ifdef ASSERT
1894 void ConnectionGraph::verify_connection_graph(
1895 GrowableArray<PointsToNode*>& ptnodes_worklist,
1896 GrowableArray<JavaObjectNode*>& non_escaped_allocs_worklist,
1897 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1898 GrowableArray<Node*>& addp_worklist) {
1899 // Verify that graph is complete - no new edges could be added.
1900 int java_objects_length = java_objects_worklist.length();
1901 int non_escaped_length = non_escaped_allocs_worklist.length();
1902 int new_edges = 0;
1903 for (int next = 0; next < java_objects_length; ++next) {
1904 JavaObjectNode* ptn = java_objects_worklist.at(next);
1905 new_edges += add_java_object_edges(ptn, true);
1906 }
1907 assert(new_edges == 0, "graph was not complete");
1908 // Verify that escape state is final.
1909 int length = non_escaped_allocs_worklist.length();
1910 find_non_escaped_objects(ptnodes_worklist, non_escaped_allocs_worklist);
1911 assert((non_escaped_length == non_escaped_allocs_worklist.length()) &&
1912 (non_escaped_length == length) &&
1913 (_worklist.length() == 0), "escape state was not final");
1914
1915 // Verify fields information.
1916 int addp_length = addp_worklist.length();
1917 for (int next = 0; next < addp_length; ++next ) {
1918 Node* n = addp_worklist.at(next);
1919 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1920 if (field->is_oop()) {
1921 // Verify that field has all bases
1922 Node* base = get_addp_base(n);
1923 PointsToNode* ptn = ptnode_adr(base->_idx);
1924 if (ptn->is_JavaObject()) {
1925 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1926 } else {
1927 assert(ptn->is_LocalVar(), "sanity");
1928 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1929 PointsToNode* e = i.get();
1930 if (e->is_JavaObject()) {
1931 assert(field->has_base(e->as_JavaObject()), "sanity");
1932 }
1933 }
1934 }
1935 // Verify that all fields have initializing values.
1936 if (field->edge_count() == 0) {
1937 tty->print_cr("----------field does not have references----------");
1938 field->dump();
1939 for (BaseIterator i(field); i.has_next(); i.next()) {
1940 PointsToNode* base = i.get();
1941 tty->print_cr("----------field has next base---------------------");
1942 base->dump();
1943 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1944 tty->print_cr("----------base has fields-------------------------");
1945 for (EdgeIterator j(base); j.has_next(); j.next()) {
1946 j.get()->dump();
1947 }
1948 tty->print_cr("----------base has references---------------------");
1949 for (UseIterator j(base); j.has_next(); j.next()) {
1950 j.get()->dump();
1951 }
1952 }
1953 }
1954 for (UseIterator i(field); i.has_next(); i.next()) {
1955 i.get()->dump();
1956 }
1957 assert(field->edge_count() > 0, "sanity");
1958 }
1959 }
1960 }
1961 }
1962 #endif
1963
1964 // Optimize ideal graph.
1965 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1966 GrowableArray<MemBarStoreStoreNode*>& storestore_worklist) {
1967 Compile* C = _compile;
1968 PhaseIterGVN* igvn = _igvn;
1969 if (EliminateLocks) {
1970 // Mark locks before changing ideal graph.
1971 int cnt = C->macro_count();
1972 for (int i = 0; i < cnt; i++) {
1973 Node *n = C->macro_node(i);
1974 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1975 AbstractLockNode* alock = n->as_AbstractLock();
1976 if (!alock->is_non_esc_obj()) {
1977 if (not_global_escape(alock->obj_node())) {
1978 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1979 // The lock could be marked eliminated by lock coarsening
1980 // code during first IGVN before EA. Replace coarsened flag
1981 // to eliminate all associated locks/unlocks.
1982 #ifdef ASSERT
1983 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1984 #endif
1985 alock->set_non_esc_obj();
1986 }
1987 }
1988 }
1989 }
1990 }
1991
1992 if (OptimizePtrCompare) {
1993 for (int i = 0; i < ptr_cmp_worklist.length(); i++) {
1994 Node *n = ptr_cmp_worklist.at(i);
1995 const TypeInt* tcmp = optimize_ptr_compare(n);
1996 if (tcmp->singleton()) {
1997 Node* cmp = igvn->makecon(tcmp);
1998 #ifndef PRODUCT
1999 if (PrintOptimizePtrCompare) {
2000 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, (tcmp == TypeInt::CC_EQ ? "EQ" : "NotEQ"));
2001 if (Verbose) {
2002 n->dump(1);
2003 }
2004 }
2005 #endif
2006 igvn->replace_node(n, cmp);
2007 }
2008 }
2009 }
2010
2011 // For MemBarStoreStore nodes added in library_call.cpp, check
2012 // escape status of associated AllocateNode and optimize out
2013 // MemBarStoreStore node if the allocated object never escapes.
2014 for (int i = 0; i < storestore_worklist.length(); i++) {
2015 Node* storestore = storestore_worklist.at(i);
2016 Node* alloc = storestore->in(MemBarNode::Precedent)->in(0);
2017 if (alloc->is_Allocate() && not_global_escape(alloc)) {
2018 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
2019 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
2020 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
2021 igvn->register_new_node_with_optimizer(mb);
2022 igvn->replace_node(storestore, mb);
2023 }
2024 }
2025 }
2026
2027 // Optimize objects compare.
2028 const TypeInt* ConnectionGraph::optimize_ptr_compare(Node* n) {
2029 assert(OptimizePtrCompare, "sanity");
2030 assert(n->Opcode() == Op_CmpN || n->Opcode() == Op_CmpP, "must be");
2031 const TypeInt* EQ = TypeInt::CC_EQ; // [0] == ZERO
2032 const TypeInt* NE = TypeInt::CC_GT; // [1] == ONE
2033 const TypeInt* UNKNOWN = TypeInt::CC; // [-1, 0,1]
2034
2035 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
2036 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
2037 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
2038 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
2039 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
2040 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
2041
2042 // Check simple cases first.
2043 if (jobj1 != NULL) {
2044 if (jobj1->escape_state() == PointsToNode::NoEscape) {
2045 if (jobj1 == jobj2) {
2046 // Comparing the same not escaping object.
2047 return EQ;
2048 }
2049 Node* obj = jobj1->ideal_node();
2050 // Comparing not escaping allocation.
2051 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2052 !ptn2->points_to(jobj1)) {
2053 return NE; // This includes nullness check.
2054 }
2055 }
2056 }
2057 if (jobj2 != NULL) {
2058 if (jobj2->escape_state() == PointsToNode::NoEscape) {
2059 Node* obj = jobj2->ideal_node();
2060 // Comparing not escaping allocation.
2061 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2062 !ptn1->points_to(jobj2)) {
2063 return NE; // This includes nullness check.
2064 }
2065 }
2066 }
2067 if (jobj1 != NULL && jobj1 != phantom_obj &&
2068 jobj2 != NULL && jobj2 != phantom_obj &&
2069 jobj1->ideal_node()->is_Con() &&
2070 jobj2->ideal_node()->is_Con()) {
2071 // Klass or String constants compare. Need to be careful with
2072 // compressed pointers - compare types of ConN and ConP instead of nodes.
2073 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
2074 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
2075 if (t1->make_ptr() == t2->make_ptr()) {
2076 return EQ;
2077 } else {
2078 return NE;
2079 }
2080 }
2081 if (ptn1->meet(ptn2)) {
2082 return UNKNOWN; // Sets are not disjoint
2083 }
2084
2085 // Sets are disjoint.
2086 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
2087 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
2088 bool set1_has_null_ptr = ptn1->points_to(null_obj);
2089 bool set2_has_null_ptr = ptn2->points_to(null_obj);
2090 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
2091 (set2_has_unknown_ptr && set1_has_null_ptr)) {
2092 // Check nullness of unknown object.
2093 return UNKNOWN;
2094 }
2095
2096 // Disjointness by itself is not sufficient since
2097 // alias analysis is not complete for escaped objects.
2098 // Disjoint sets are definitely unrelated only when
2099 // at least one set has only not escaping allocations.
2100 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2101 if (ptn1->non_escaping_allocation()) {
2102 return NE;
2103 }
2104 }
2105 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2106 if (ptn2->non_escaping_allocation()) {
2107 return NE;
2108 }
2109 }
2110 return UNKNOWN;
2111 }
2112
2113 // Connection Graph construction functions.
2114
2115 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2116 PointsToNode* ptadr = _nodes.at(n->_idx);
2117 if (ptadr != NULL) {
2118 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2119 return;
2120 }
2121 Compile* C = _compile;
2122 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2123 map_ideal_node(n, ptadr);
2124 }
2125
2126 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2127 PointsToNode* ptadr = _nodes.at(n->_idx);
2128 if (ptadr != NULL) {
2129 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2130 return;
2131 }
2132 Compile* C = _compile;
2133 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2134 map_ideal_node(n, ptadr);
2135 }
2136
2137 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2138 PointsToNode* ptadr = _nodes.at(n->_idx);
2139 if (ptadr != NULL) {
2140 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2141 return;
2142 }
2143 bool unsafe = false;
2144 bool is_oop = is_oop_field(n, offset, &unsafe);
2145 if (unsafe) {
2146 es = PointsToNode::GlobalEscape;
2147 }
2148 Compile* C = _compile;
2149 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2150 map_ideal_node(n, field);
2151 }
2152
2153 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2154 PointsToNode* src, PointsToNode* dst) {
2155 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2156 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2157 PointsToNode* ptadr = _nodes.at(n->_idx);
2158 if (ptadr != NULL) {
2159 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2160 return;
2161 }
2162 Compile* C = _compile;
2163 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2164 map_ideal_node(n, ptadr);
2165 // Add edge from arraycopy node to source object.
2166 (void)add_edge(ptadr, src);
2167 src->set_arraycopy_src();
2168 // Add edge from destination object to arraycopy node.
2169 (void)add_edge(dst, ptadr);
2170 dst->set_arraycopy_dst();
2171 }
2172
2173 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2174 const Type* adr_type = n->as_AddP()->bottom_type();
2175 BasicType bt = T_INT;
2176 if (offset == Type::OffsetBot) {
2177 // Check only oop fields.
2178 if (!adr_type->isa_aryptr() ||
2179 (adr_type->isa_aryptr()->klass() == NULL) ||
2180 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2181 // OffsetBot is used to reference array's element. Ignore first AddP.
2182 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2183 bt = T_OBJECT;
2184 }
2185 }
2186 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2187 if (adr_type->isa_instptr()) {
2188 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2189 if (field != NULL) {
2190 bt = field->layout_type();
2191 } else {
2192 // Check for unsafe oop field access
2193 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2194 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2195 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2196 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2197 bt = T_OBJECT;
2198 (*unsafe) = true;
2199 }
2200 }
2201 } else if (adr_type->isa_aryptr()) {
2202 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2203 // Ignore array length load.
2204 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2205 // Ignore first AddP.
2206 } else {
2207 const Type* elemtype = adr_type->isa_aryptr()->elem();
2208 bt = elemtype->array_element_basic_type();
2209 }
2210 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2211 // Allocation initialization, ThreadLocal field access, unsafe access
2212 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2213 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2214 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2215 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2216 bt = T_OBJECT;
2217 }
2218 }
2219 }
2220 // Note: T_NARROWOOP is not classed as a real reference type
2221 return (is_reference_type(bt) || bt == T_NARROWOOP);
2222 }
2223
2224 // Returns unique pointed java object or NULL.
2225 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2226 assert(!_collecting, "should not call when constructed graph");
2227 // If the node was created after the escape computation we can't answer.
2228 uint idx = n->_idx;
2229 if (idx >= nodes_size()) {
2230 return NULL;
2231 }
2232 PointsToNode* ptn = ptnode_adr(idx);
2233 if (ptn == NULL) {
2234 return NULL;
2235 }
2236 if (ptn->is_JavaObject()) {
2237 return ptn->as_JavaObject();
2238 }
2239 assert(ptn->is_LocalVar(), "sanity");
2240 // Check all java objects it points to.
2241 JavaObjectNode* jobj = NULL;
2242 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2243 PointsToNode* e = i.get();
2244 if (e->is_JavaObject()) {
2245 if (jobj == NULL) {
2246 jobj = e->as_JavaObject();
2247 } else if (jobj != e) {
2248 return NULL;
2249 }
2250 }
2251 }
2252 return jobj;
2253 }
2254
2255 // Return true if this node points only to non-escaping allocations.
2256 bool PointsToNode::non_escaping_allocation() {
2257 if (is_JavaObject()) {
2258 Node* n = ideal_node();
2259 if (n->is_Allocate() || n->is_CallStaticJava()) {
2260 return (escape_state() == PointsToNode::NoEscape);
2261 } else {
2262 return false;
2263 }
2264 }
2265 assert(is_LocalVar(), "sanity");
2266 // Check all java objects it points to.
2267 for (EdgeIterator i(this); i.has_next(); i.next()) {
2268 PointsToNode* e = i.get();
2269 if (e->is_JavaObject()) {
2270 Node* n = e->ideal_node();
2271 if ((e->escape_state() != PointsToNode::NoEscape) ||
2272 !(n->is_Allocate() || n->is_CallStaticJava())) {
2273 return false;
2274 }
2275 }
2276 }
2277 return true;
2278 }
2279
2280 // Return true if we know the node does not escape globally.
2281 bool ConnectionGraph::not_global_escape(Node *n) {
2282 assert(!_collecting, "should not call during graph construction");
2283 // If the node was created after the escape computation we can't answer.
2284 uint idx = n->_idx;
2285 if (idx >= nodes_size()) {
2286 return false;
2287 }
2288 PointsToNode* ptn = ptnode_adr(idx);
2289 if (ptn == NULL) {
2290 return false; // not in congraph (e.g. ConI)
2291 }
2292 PointsToNode::EscapeState es = ptn->escape_state();
2293 // If we have already computed a value, return it.
2294 if (es >= PointsToNode::GlobalEscape) {
2295 return false;
2296 }
2297 if (ptn->is_JavaObject()) {
2298 return true; // (es < PointsToNode::GlobalEscape);
2299 }
2300 assert(ptn->is_LocalVar(), "sanity");
2301 // Check all java objects it points to.
2302 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2303 if (i.get()->escape_state() >= PointsToNode::GlobalEscape) {
2304 return false;
2305 }
2306 }
2307 return true;
2308 }
2309
2310
2311 // Helper functions
2312
2313 // Return true if this node points to specified node or nodes it points to.
2314 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2315 if (is_JavaObject()) {
2316 return (this == ptn);
2317 }
2318 assert(is_LocalVar() || is_Field(), "sanity");
2319 for (EdgeIterator i(this); i.has_next(); i.next()) {
2320 if (i.get() == ptn) {
2321 return true;
2322 }
2323 }
2324 return false;
2325 }
2326
2327 // Return true if one node points to an other.
2328 bool PointsToNode::meet(PointsToNode* ptn) {
2329 if (this == ptn) {
2330 return true;
2331 } else if (ptn->is_JavaObject()) {
2332 return this->points_to(ptn->as_JavaObject());
2333 } else if (this->is_JavaObject()) {
2334 return ptn->points_to(this->as_JavaObject());
2335 }
2336 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2337 int ptn_count = ptn->edge_count();
2338 for (EdgeIterator i(this); i.has_next(); i.next()) {
2339 PointsToNode* this_e = i.get();
2340 for (int j = 0; j < ptn_count; j++) {
2341 if (this_e == ptn->edge(j)) {
2342 return true;
2343 }
2344 }
2345 }
2346 return false;
2347 }
2348
2349 #ifdef ASSERT
2350 // Return true if bases point to this java object.
2351 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2352 for (BaseIterator i(this); i.has_next(); i.next()) {
2353 if (i.get() == jobj) {
2354 return true;
2355 }
2356 }
2357 return false;
2358 }
2359 #endif
2360
2361 bool ConnectionGraph::is_captured_store_address(Node* addp) {
2362 // Handle simple case first.
2363 assert(_igvn->type(addp)->isa_oopptr() == NULL, "should be raw access");
2364 if (addp->in(AddPNode::Address)->is_Proj() && addp->in(AddPNode::Address)->in(0)->is_Allocate()) {
2365 return true;
2366 } else if (addp->in(AddPNode::Address)->is_Phi()) {
2367 for (DUIterator_Fast imax, i = addp->fast_outs(imax); i < imax; i++) {
2368 Node* addp_use = addp->fast_out(i);
2369 if (addp_use->is_Store()) {
2370 for (DUIterator_Fast jmax, j = addp_use->fast_outs(jmax); j < jmax; j++) {
2371 if (addp_use->fast_out(j)->is_Initialize()) {
2372 return true;
2373 }
2374 }
2375 }
2376 }
2377 }
2378 return false;
2379 }
2380
2381 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2382 const Type *adr_type = phase->type(adr);
2383 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL && is_captured_store_address(adr)) {
2384 // We are computing a raw address for a store captured by an Initialize
2385 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2386 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2387 assert(offs != Type::OffsetBot ||
2388 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2389 "offset must be a constant or it is initialization of array");
2390 return offs;
2391 }
2392 const TypePtr *t_ptr = adr_type->isa_ptr();
2393 assert(t_ptr != NULL, "must be a pointer type");
2394 return t_ptr->offset();
2395 }
2396
2397 Node* ConnectionGraph::get_addp_base(Node *addp) {
2398 assert(addp->is_AddP(), "must be AddP");
2399 //
2400 // AddP cases for Base and Address inputs:
2401 // case #1. Direct object's field reference:
2402 // Allocate
2403 // |
2404 // Proj #5 ( oop result )
2405 // |
2406 // CheckCastPP (cast to instance type)
2407 // | |
2408 // AddP ( base == address )
2409 //
2410 // case #2. Indirect object's field reference:
2411 // Phi
2412 // |
2413 // CastPP (cast to instance type)
2414 // | |
2415 // AddP ( base == address )
2416 //
2417 // case #3. Raw object's field reference for Initialize node:
2418 // Allocate
2419 // |
2420 // Proj #5 ( oop result )
2421 // top |
2422 // \ |
2423 // AddP ( base == top )
2424 //
2425 // case #4. Array's element reference:
2426 // {CheckCastPP | CastPP}
2427 // | | |
2428 // | AddP ( array's element offset )
2429 // | |
2430 // AddP ( array's offset )
2431 //
2432 // case #5. Raw object's field reference for arraycopy stub call:
2433 // The inline_native_clone() case when the arraycopy stub is called
2434 // after the allocation before Initialize and CheckCastPP nodes.
2435 // Allocate
2436 // |
2437 // Proj #5 ( oop result )
2438 // | |
2439 // AddP ( base == address )
2440 //
2441 // case #6. Constant Pool, ThreadLocal, CastX2P or
2442 // Raw object's field reference:
2443 // {ConP, ThreadLocal, CastX2P, raw Load}
2444 // top |
2445 // \ |
2446 // AddP ( base == top )
2447 //
2448 // case #7. Klass's field reference.
2449 // LoadKlass
2450 // | |
2451 // AddP ( base == address )
2452 //
2453 // case #8. narrow Klass's field reference.
2454 // LoadNKlass
2455 // |
2456 // DecodeN
2457 // | |
2458 // AddP ( base == address )
2459 //
2460 // case #9. Mixed unsafe access
2461 // {instance}
2462 // |
2463 // CheckCastPP (raw)
2464 // top |
2465 // \ |
2466 // AddP ( base == top )
2467 //
2468 Node *base = addp->in(AddPNode::Base);
2469 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2470 base = addp->in(AddPNode::Address);
2471 while (base->is_AddP()) {
2472 // Case #6 (unsafe access) may have several chained AddP nodes.
2473 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2474 base = base->in(AddPNode::Address);
2475 }
2476 if (base->Opcode() == Op_CheckCastPP &&
2477 base->bottom_type()->isa_rawptr() &&
2478 _igvn->type(base->in(1))->isa_oopptr()) {
2479 base = base->in(1); // Case #9
2480 } else {
2481 Node* uncast_base = base->uncast();
2482 int opcode = uncast_base->Opcode();
2483 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2484 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2485 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2486 is_captured_store_address(addp), "sanity");
2487 }
2488 }
2489 return base;
2490 }
2491
2492 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2493 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2494 Node* addp2 = addp->raw_out(0);
2495 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2496 addp2->in(AddPNode::Base) == n &&
2497 addp2->in(AddPNode::Address) == addp) {
2498 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2499 //
2500 // Find array's offset to push it on worklist first and
2501 // as result process an array's element offset first (pushed second)
2502 // to avoid CastPP for the array's offset.
2503 // Otherwise the inserted CastPP (LocalVar) will point to what
2504 // the AddP (Field) points to. Which would be wrong since
2505 // the algorithm expects the CastPP has the same point as
2506 // as AddP's base CheckCastPP (LocalVar).
2507 //
2508 // ArrayAllocation
2509 // |
2510 // CheckCastPP
2511 // |
2512 // memProj (from ArrayAllocation CheckCastPP)
2513 // | ||
2514 // | || Int (element index)
2515 // | || | ConI (log(element size))
2516 // | || | /
2517 // | || LShift
2518 // | || /
2519 // | AddP (array's element offset)
2520 // | |
2521 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2522 // | / /
2523 // AddP (array's offset)
2524 // |
2525 // Load/Store (memory operation on array's element)
2526 //
2527 return addp2;
2528 }
2529 return NULL;
2530 }
2531
2532 //
2533 // Adjust the type and inputs of an AddP which computes the
2534 // address of a field of an instance
2535 //
2536 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2537 PhaseGVN* igvn = _igvn;
2538 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2539 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2540 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2541 if (t == NULL) {
2542 // We are computing a raw address for a store captured by an Initialize
2543 // compute an appropriate address type (cases #3 and #5).
2544 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2545 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2546 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2547 assert(offs != Type::OffsetBot, "offset must be a constant");
2548 t = base_t->add_offset(offs)->is_oopptr();
2549 }
2550 int inst_id = base_t->instance_id();
2551 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2552 "old type must be non-instance or match new type");
2553
2554 // The type 't' could be subclass of 'base_t'.
2555 // As result t->offset() could be large then base_t's size and it will
2556 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2557 // constructor verifies correctness of the offset.
2558 //
2559 // It could happened on subclass's branch (from the type profiling
2560 // inlining) which was not eliminated during parsing since the exactness
2561 // of the allocation type was not propagated to the subclass type check.
2562 //
2563 // Or the type 't' could be not related to 'base_t' at all.
2564 // It could happened when CHA type is different from MDO type on a dead path
2565 // (for example, from instanceof check) which is not collapsed during parsing.
2566 //
2567 // Do nothing for such AddP node and don't process its users since
2568 // this code branch will go away.
2569 //
2570 if (!t->is_known_instance() &&
2571 !base_t->klass()->is_subtype_of(t->klass())) {
2572 return false; // bail out
2573 }
2574 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2575 // Do NOT remove the next line: ensure a new alias index is allocated
2576 // for the instance type. Note: C++ will not remove it since the call
2577 // has side effect.
2578 int alias_idx = _compile->get_alias_index(tinst);
2579 igvn->set_type(addp, tinst);
2580 // record the allocation in the node map
2581 set_map(addp, get_map(base->_idx));
2582 // Set addp's Base and Address to 'base'.
2583 Node *abase = addp->in(AddPNode::Base);
2584 Node *adr = addp->in(AddPNode::Address);
2585 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2586 adr->in(0)->_idx == (uint)inst_id) {
2587 // Skip AddP cases #3 and #5.
2588 } else {
2589 assert(!abase->is_top(), "sanity"); // AddP case #3
2590 if (abase != base) {
2591 igvn->hash_delete(addp);
2592 addp->set_req(AddPNode::Base, base);
2593 if (abase == adr) {
2594 addp->set_req(AddPNode::Address, base);
2595 } else {
2596 // AddP case #4 (adr is array's element offset AddP node)
2597 #ifdef ASSERT
2598 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2599 assert(adr->is_AddP() && atype != NULL &&
2600 atype->instance_id() == inst_id, "array's element offset should be processed first");
2601 #endif
2602 }
2603 igvn->hash_insert(addp);
2604 }
2605 }
2606 // Put on IGVN worklist since at least addp's type was changed above.
2607 record_for_optimizer(addp);
2608 return true;
2609 }
2610
2611 //
2612 // Create a new version of orig_phi if necessary. Returns either the newly
2613 // created phi or an existing phi. Sets create_new to indicate whether a new
2614 // phi was created. Cache the last newly created phi in the node map.
2615 //
2616 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2617 Compile *C = _compile;
2618 PhaseGVN* igvn = _igvn;
2619 new_created = false;
2620 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2621 // nothing to do if orig_phi is bottom memory or matches alias_idx
2622 if (phi_alias_idx == alias_idx) {
2623 return orig_phi;
2624 }
2625 // Have we recently created a Phi for this alias index?
2626 PhiNode *result = get_map_phi(orig_phi->_idx);
2627 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2628 return result;
2629 }
2630 // Previous check may fail when the same wide memory Phi was split into Phis
2631 // for different memory slices. Search all Phis for this region.
2632 if (result != NULL) {
2633 Node* region = orig_phi->in(0);
2634 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2635 Node* phi = region->fast_out(i);
2636 if (phi->is_Phi() &&
2637 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2638 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2639 return phi->as_Phi();
2640 }
2641 }
2642 }
2643 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2644 if (C->do_escape_analysis() == true && !C->failing()) {
2645 // Retry compilation without escape analysis.
2646 // If this is the first failure, the sentinel string will "stick"
2647 // to the Compile object, and the C2Compiler will see it and retry.
2648 C->record_failure(C2Compiler::retry_no_escape_analysis());
2649 }
2650 return NULL;
2651 }
2652 orig_phi_worklist.append_if_missing(orig_phi);
2653 const TypePtr *atype = C->get_adr_type(alias_idx);
2654 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2655 C->copy_node_notes_to(result, orig_phi);
2656 igvn->set_type(result, result->bottom_type());
2657 record_for_optimizer(result);
2658 set_map(orig_phi, result);
2659 new_created = true;
2660 return result;
2661 }
2662
2663 //
2664 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2665 // specified alias index.
2666 //
2667 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2668 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2669 Compile *C = _compile;
2670 PhaseGVN* igvn = _igvn;
2671 bool new_phi_created;
2672 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2673 if (!new_phi_created) {
2674 return result;
2675 }
2676 GrowableArray<PhiNode *> phi_list;
2677 GrowableArray<uint> cur_input;
2678 PhiNode *phi = orig_phi;
2679 uint idx = 1;
2680 bool finished = false;
2681 while(!finished) {
2682 while (idx < phi->req()) {
2683 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2684 if (mem != NULL && mem->is_Phi()) {
2685 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2686 if (new_phi_created) {
2687 // found an phi for which we created a new split, push current one on worklist and begin
2688 // processing new one
2689 phi_list.push(phi);
2690 cur_input.push(idx);
2691 phi = mem->as_Phi();
2692 result = newphi;
2693 idx = 1;
2694 continue;
2695 } else {
2696 mem = newphi;
2697 }
2698 }
2699 if (C->failing()) {
2700 return NULL;
2701 }
2702 result->set_req(idx++, mem);
2703 }
2704 #ifdef ASSERT
2705 // verify that the new Phi has an input for each input of the original
2706 assert( phi->req() == result->req(), "must have same number of inputs.");
2707 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2708 #endif
2709 // Check if all new phi's inputs have specified alias index.
2710 // Otherwise use old phi.
2711 for (uint i = 1; i < phi->req(); i++) {
2712 Node* in = result->in(i);
2713 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2714 }
2715 // we have finished processing a Phi, see if there are any more to do
2716 finished = (phi_list.length() == 0 );
2717 if (!finished) {
2718 phi = phi_list.pop();
2719 idx = cur_input.pop();
2720 PhiNode *prev_result = get_map_phi(phi->_idx);
2721 prev_result->set_req(idx++, result);
2722 result = prev_result;
2723 }
2724 }
2725 return result;
2726 }
2727
2728 //
2729 // The next methods are derived from methods in MemNode.
2730 //
2731 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2732 Node *mem = mmem;
2733 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2734 // means an array I have not precisely typed yet. Do not do any
2735 // alias stuff with it any time soon.
2736 if (toop->base() != Type::AnyPtr &&
2737 !(toop->klass() != NULL &&
2738 toop->klass()->is_java_lang_Object() &&
2739 toop->offset() == Type::OffsetBot)) {
2740 mem = mmem->memory_at(alias_idx);
2741 // Update input if it is progress over what we have now
2742 }
2743 return mem;
2744 }
2745
2746 //
2747 // Move memory users to their memory slices.
2748 //
2749 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2750 Compile* C = _compile;
2751 PhaseGVN* igvn = _igvn;
2752 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2753 assert(tp != NULL, "ptr type");
2754 int alias_idx = C->get_alias_index(tp);
2755 int general_idx = C->get_general_index(alias_idx);
2756
2757 // Move users first
2758 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2759 Node* use = n->fast_out(i);
2760 if (use->is_MergeMem()) {
2761 MergeMemNode* mmem = use->as_MergeMem();
2762 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2763 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2764 continue; // Nothing to do
2765 }
2766 // Replace previous general reference to mem node.
2767 uint orig_uniq = C->unique();
2768 Node* m = find_inst_mem(n, general_idx, orig_phis);
2769 assert(orig_uniq == C->unique(), "no new nodes");
2770 mmem->set_memory_at(general_idx, m);
2771 --imax;
2772 --i;
2773 } else if (use->is_MemBar()) {
2774 assert(!use->is_Initialize(), "initializing stores should not be moved");
2775 if (use->req() > MemBarNode::Precedent &&
2776 use->in(MemBarNode::Precedent) == n) {
2777 // Don't move related membars.
2778 record_for_optimizer(use);
2779 continue;
2780 }
2781 tp = use->as_MemBar()->adr_type()->isa_ptr();
2782 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2783 alias_idx == general_idx) {
2784 continue; // Nothing to do
2785 }
2786 // Move to general memory slice.
2787 uint orig_uniq = C->unique();
2788 Node* m = find_inst_mem(n, general_idx, orig_phis);
2789 assert(orig_uniq == C->unique(), "no new nodes");
2790 igvn->hash_delete(use);
2791 imax -= use->replace_edge(n, m, igvn);
2792 igvn->hash_insert(use);
2793 record_for_optimizer(use);
2794 --i;
2795 #ifdef ASSERT
2796 } else if (use->is_Mem()) {
2797 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2798 // Don't move related cardmark.
2799 continue;
2800 }
2801 // Memory nodes should have new memory input.
2802 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2803 assert(tp != NULL, "ptr type");
2804 int idx = C->get_alias_index(tp);
2805 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2806 "Following memory nodes should have new memory input or be on the same memory slice");
2807 } else if (use->is_Phi()) {
2808 // Phi nodes should be split and moved already.
2809 tp = use->as_Phi()->adr_type()->isa_ptr();
2810 assert(tp != NULL, "ptr type");
2811 int idx = C->get_alias_index(tp);
2812 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2813 } else {
2814 use->dump();
2815 assert(false, "should not be here");
2816 #endif
2817 }
2818 }
2819 }
2820
2821 //
2822 // Search memory chain of "mem" to find a MemNode whose address
2823 // is the specified alias index.
2824 //
2825 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2826 if (orig_mem == NULL) {
2827 return orig_mem;
2828 }
2829 Compile* C = _compile;
2830 PhaseGVN* igvn = _igvn;
2831 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2832 bool is_instance = (toop != NULL) && toop->is_known_instance();
2833 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2834 Node *prev = NULL;
2835 Node *result = orig_mem;
2836 while (prev != result) {
2837 prev = result;
2838 if (result == start_mem) {
2839 break; // hit one of our sentinels
2840 }
2841 if (result->is_Mem()) {
2842 const Type *at = igvn->type(result->in(MemNode::Address));
2843 if (at == Type::TOP) {
2844 break; // Dead
2845 }
2846 assert (at->isa_ptr() != NULL, "pointer type required.");
2847 int idx = C->get_alias_index(at->is_ptr());
2848 if (idx == alias_idx) {
2849 break; // Found
2850 }
2851 if (!is_instance && (at->isa_oopptr() == NULL ||
2852 !at->is_oopptr()->is_known_instance())) {
2853 break; // Do not skip store to general memory slice.
2854 }
2855 result = result->in(MemNode::Memory);
2856 }
2857 if (!is_instance) {
2858 continue; // don't search further for non-instance types
2859 }
2860 // skip over a call which does not affect this memory slice
2861 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2862 Node *proj_in = result->in(0);
2863 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2864 break; // hit one of our sentinels
2865 } else if (proj_in->is_Call()) {
2866 // ArrayCopy node processed here as well
2867 CallNode *call = proj_in->as_Call();
2868 if (!call->may_modify(toop, igvn)) {
2869 result = call->in(TypeFunc::Memory);
2870 }
2871 } else if (proj_in->is_Initialize()) {
2872 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2873 // Stop if this is the initialization for the object instance which
2874 // which contains this memory slice, otherwise skip over it.
2875 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2876 result = proj_in->in(TypeFunc::Memory);
2877 }
2878 } else if (proj_in->is_MemBar()) {
2879 // Check if there is an array copy for a clone
2880 // Step over GC barrier when ReduceInitialCardMarks is disabled
2881 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2882 Node* control_proj_ac = bs->step_over_gc_barrier(proj_in->in(0));
2883
2884 if (control_proj_ac->is_Proj() && control_proj_ac->in(0)->is_ArrayCopy()) {
2885 // Stop if it is a clone
2886 ArrayCopyNode* ac = control_proj_ac->in(0)->as_ArrayCopy();
2887 if (ac->may_modify(toop, igvn)) {
2888 break;
2889 }
2890 }
2891 result = proj_in->in(TypeFunc::Memory);
2892 }
2893 } else if (result->is_MergeMem()) {
2894 MergeMemNode *mmem = result->as_MergeMem();
2895 result = step_through_mergemem(mmem, alias_idx, toop);
2896 if (result == mmem->base_memory()) {
2897 // Didn't find instance memory, search through general slice recursively.
2898 result = mmem->memory_at(C->get_general_index(alias_idx));
2899 result = find_inst_mem(result, alias_idx, orig_phis);
2900 if (C->failing()) {
2901 return NULL;
2902 }
2903 mmem->set_memory_at(alias_idx, result);
2904 }
2905 } else if (result->is_Phi() &&
2906 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2907 Node *un = result->as_Phi()->unique_input(igvn);
2908 if (un != NULL) {
2909 orig_phis.append_if_missing(result->as_Phi());
2910 result = un;
2911 } else {
2912 break;
2913 }
2914 } else if (result->is_ClearArray()) {
2915 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2916 // Can not bypass initialization of the instance
2917 // we are looking for.
2918 break;
2919 }
2920 // Otherwise skip it (the call updated 'result' value).
2921 } else if (result->Opcode() == Op_SCMemProj) {
2922 Node* mem = result->in(0);
2923 Node* adr = NULL;
2924 if (mem->is_LoadStore()) {
2925 adr = mem->in(MemNode::Address);
2926 } else {
2927 assert(mem->Opcode() == Op_EncodeISOArray ||
2928 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2929 adr = mem->in(3); // Memory edge corresponds to destination array
2930 }
2931 const Type *at = igvn->type(adr);
2932 if (at != Type::TOP) {
2933 assert(at->isa_ptr() != NULL, "pointer type required.");
2934 int idx = C->get_alias_index(at->is_ptr());
2935 if (idx == alias_idx) {
2936 // Assert in debug mode
2937 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2938 break; // In product mode return SCMemProj node
2939 }
2940 }
2941 result = mem->in(MemNode::Memory);
2942 } else if (result->Opcode() == Op_StrInflatedCopy) {
2943 Node* adr = result->in(3); // Memory edge corresponds to destination array
2944 const Type *at = igvn->type(adr);
2945 if (at != Type::TOP) {
2946 assert(at->isa_ptr() != NULL, "pointer type required.");
2947 int idx = C->get_alias_index(at->is_ptr());
2948 if (idx == alias_idx) {
2949 // Assert in debug mode
2950 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2951 break; // In product mode return SCMemProj node
2952 }
2953 }
2954 result = result->in(MemNode::Memory);
2955 }
2956 }
2957 if (result->is_Phi()) {
2958 PhiNode *mphi = result->as_Phi();
2959 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2960 const TypePtr *t = mphi->adr_type();
2961 if (!is_instance) {
2962 // Push all non-instance Phis on the orig_phis worklist to update inputs
2963 // during Phase 4 if needed.
2964 orig_phis.append_if_missing(mphi);
2965 } else if (C->get_alias_index(t) != alias_idx) {
2966 // Create a new Phi with the specified alias index type.
2967 result = split_memory_phi(mphi, alias_idx, orig_phis);
2968 }
2969 }
2970 // the result is either MemNode, PhiNode, InitializeNode.
2971 return result;
2972 }
2973
2974 //
2975 // Convert the types of non-escaped object to instance types where possible,
2976 // propagate the new type information through the graph, and update memory
2977 // edges and MergeMem inputs to reflect the new type.
2978 //
2979 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2980 // The processing is done in 4 phases:
2981 //
2982 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2983 // types for the CheckCastPP for allocations where possible.
2984 // Propagate the new types through users as follows:
2985 // casts and Phi: push users on alloc_worklist
2986 // AddP: cast Base and Address inputs to the instance type
2987 // push any AddP users on alloc_worklist and push any memnode
2988 // users onto memnode_worklist.
2989 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2990 // search the Memory chain for a store with the appropriate type
2991 // address type. If a Phi is found, create a new version with
2992 // the appropriate memory slices from each of the Phi inputs.
2993 // For stores, process the users as follows:
2994 // MemNode: push on memnode_worklist
2995 // MergeMem: push on mergemem_worklist
2996 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2997 // moving the first node encountered of each instance type to the
2998 // the input corresponding to its alias index.
2999 // appropriate memory slice.
3000 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
3001 //
3002 // In the following example, the CheckCastPP nodes are the cast of allocation
3003 // results and the allocation of node 29 is non-escaped and eligible to be an
3004 // instance type.
3005 //
3006 // We start with:
3007 //
3008 // 7 Parm #memory
3009 // 10 ConI "12"
3010 // 19 CheckCastPP "Foo"
3011 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
3012 // 29 CheckCastPP "Foo"
3013 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
3014 //
3015 // 40 StoreP 25 7 20 ... alias_index=4
3016 // 50 StoreP 35 40 30 ... alias_index=4
3017 // 60 StoreP 45 50 20 ... alias_index=4
3018 // 70 LoadP _ 60 30 ... alias_index=4
3019 // 80 Phi 75 50 60 Memory alias_index=4
3020 // 90 LoadP _ 80 30 ... alias_index=4
3021 // 100 LoadP _ 80 20 ... alias_index=4
3022 //
3023 //
3024 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
3025 // and creating a new alias index for node 30. This gives:
3026 //
3027 // 7 Parm #memory
3028 // 10 ConI "12"
3029 // 19 CheckCastPP "Foo"
3030 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
3031 // 29 CheckCastPP "Foo" iid=24
3032 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
3033 //
3034 // 40 StoreP 25 7 20 ... alias_index=4
3035 // 50 StoreP 35 40 30 ... alias_index=6
3036 // 60 StoreP 45 50 20 ... alias_index=4
3037 // 70 LoadP _ 60 30 ... alias_index=6
3038 // 80 Phi 75 50 60 Memory alias_index=4
3039 // 90 LoadP _ 80 30 ... alias_index=6
3040 // 100 LoadP _ 80 20 ... alias_index=4
3041 //
3042 // In phase 2, new memory inputs are computed for the loads and stores,
3043 // And a new version of the phi is created. In phase 4, the inputs to
3044 // node 80 are updated and then the memory nodes are updated with the
3045 // values computed in phase 2. This results in:
3046 //
3047 // 7 Parm #memory
3048 // 10 ConI "12"
3049 // 19 CheckCastPP "Foo"
3050 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
3051 // 29 CheckCastPP "Foo" iid=24
3052 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
3053 //
3054 // 40 StoreP 25 7 20 ... alias_index=4
3055 // 50 StoreP 35 7 30 ... alias_index=6
3056 // 60 StoreP 45 40 20 ... alias_index=4
3057 // 70 LoadP _ 50 30 ... alias_index=6
3058 // 80 Phi 75 40 60 Memory alias_index=4
3059 // 120 Phi 75 50 50 Memory alias_index=6
3060 // 90 LoadP _ 120 30 ... alias_index=6
3061 // 100 LoadP _ 80 20 ... alias_index=4
3062 //
3063 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist,
3064 GrowableArray<ArrayCopyNode*> &arraycopy_worklist,
3065 GrowableArray<MergeMemNode*> &mergemem_worklist) {
3066 GrowableArray<Node *> memnode_worklist;
3067 GrowableArray<PhiNode *> orig_phis;
3068 PhaseIterGVN *igvn = _igvn;
3069 uint new_index_start = (uint) _compile->num_alias_types();
3070 VectorSet visited;
3071 ideal_nodes.clear(); // Reset for use with set_map/get_map.
3072 uint unique_old = _compile->unique();
3073
3074 // Phase 1: Process possible allocations from alloc_worklist.
3075 // Create instance types for the CheckCastPP for allocations where possible.
3076 //
3077 // (Note: don't forget to change the order of the second AddP node on
3078 // the alloc_worklist if the order of the worklist processing is changed,
3079 // see the comment in find_second_addp().)
3080 //
3081 while (alloc_worklist.length() != 0) {
3082 Node *n = alloc_worklist.pop();
3083 uint ni = n->_idx;
3084 if (n->is_Call()) {
3085 CallNode *alloc = n->as_Call();
3086 // copy escape information to call node
3087 PointsToNode* ptn = ptnode_adr(alloc->_idx);
3088 PointsToNode::EscapeState es = ptn->escape_state();
3089 // We have an allocation or call which returns a Java object,
3090 // see if it is non-escaped.
3091 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable()) {
3092 continue;
3093 }
3094 // Find CheckCastPP for the allocate or for the return value of a call
3095 n = alloc->result_cast();
3096 if (n == NULL) { // No uses except Initialize node
3097 if (alloc->is_Allocate()) {
3098 // Set the scalar_replaceable flag for allocation
3099 // so it could be eliminated if it has no uses.
3100 alloc->as_Allocate()->_is_scalar_replaceable = true;
3101 }
3102 continue;
3103 }
3104 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
3105 // we could reach here for allocate case if one init is associated with many allocs.
3106 if (alloc->is_Allocate()) {
3107 alloc->as_Allocate()->_is_scalar_replaceable = false;
3108 }
3109 continue;
3110 }
3111
3112 // The inline code for Object.clone() casts the allocation result to
3113 // java.lang.Object and then to the actual type of the allocated
3114 // object. Detect this case and use the second cast.
3115 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
3116 // the allocation result is cast to java.lang.Object and then
3117 // to the actual Array type.
3118 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
3119 && (alloc->is_AllocateArray() ||
3120 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeInstKlassPtr::OBJECT)) {
3121 Node *cast2 = NULL;
3122 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3123 Node *use = n->fast_out(i);
3124 if (use->is_CheckCastPP()) {
3125 cast2 = use;
3126 break;
3127 }
3128 }
3129 if (cast2 != NULL) {
3130 n = cast2;
3131 } else {
3132 // Non-scalar replaceable if the allocation type is unknown statically
3133 // (reflection allocation), the object can't be restored during
3134 // deoptimization without precise type.
3135 continue;
3136 }
3137 }
3138
3139 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
3140 if (t == NULL) {
3141 continue; // not a TypeOopPtr
3142 }
3143 if (!t->klass_is_exact()) {
3144 continue; // not an unique type
3145 }
3146 if (alloc->is_Allocate()) {
3147 // Set the scalar_replaceable flag for allocation
3148 // so it could be eliminated.
3149 alloc->as_Allocate()->_is_scalar_replaceable = true;
3150 }
3151 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3152 // in order for an object to be scalar-replaceable, it must be:
3153 // - a direct allocation (not a call returning an object)
3154 // - non-escaping
3155 // - eligible to be a unique type
3156 // - not determined to be ineligible by escape analysis
3157 set_map(alloc, n);
3158 set_map(n, alloc);
3159 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3160 igvn->hash_delete(n);
3161 igvn->set_type(n, tinst);
3162 n->raise_bottom_type(tinst);
3163 igvn->hash_insert(n);
3164 record_for_optimizer(n);
3165 // Allocate an alias index for the header fields. Accesses to
3166 // the header emitted during macro expansion wouldn't have
3167 // correct memory state otherwise.
3168 _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
3169 _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
3170 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3171
3172 // First, put on the worklist all Field edges from Connection Graph
3173 // which is more accurate than putting immediate users from Ideal Graph.
3174 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3175 PointsToNode* tgt = e.get();
3176 if (tgt->is_Arraycopy()) {
3177 continue;
3178 }
3179 Node* use = tgt->ideal_node();
3180 assert(tgt->is_Field() && use->is_AddP(),
3181 "only AddP nodes are Field edges in CG");
3182 if (use->outcnt() > 0) { // Don't process dead nodes
3183 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3184 if (addp2 != NULL) {
3185 assert(alloc->is_AllocateArray(),"array allocation was expected");
3186 alloc_worklist.append_if_missing(addp2);
3187 }
3188 alloc_worklist.append_if_missing(use);
3189 }
3190 }
3191
3192 // An allocation may have an Initialize which has raw stores. Scan
3193 // the users of the raw allocation result and push AddP users
3194 // on alloc_worklist.
3195 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3196 assert (raw_result != NULL, "must have an allocation result");
3197 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3198 Node *use = raw_result->fast_out(i);
3199 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3200 Node* addp2 = find_second_addp(use, raw_result);
3201 if (addp2 != NULL) {
3202 assert(alloc->is_AllocateArray(),"array allocation was expected");
3203 alloc_worklist.append_if_missing(addp2);
3204 }
3205 alloc_worklist.append_if_missing(use);
3206 } else if (use->is_MemBar()) {
3207 memnode_worklist.append_if_missing(use);
3208 }
3209 }
3210 }
3211 } else if (n->is_AddP()) {
3212 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3213 if (jobj == NULL || jobj == phantom_obj) {
3214 #ifdef ASSERT
3215 ptnode_adr(get_addp_base(n)->_idx)->dump();
3216 ptnode_adr(n->_idx)->dump();
3217 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3218 #endif
3219 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3220 return;
3221 }
3222 Node *base = get_map(jobj->idx()); // CheckCastPP node
3223 if (!split_AddP(n, base)) continue; // wrong type from dead path
3224 } else if (n->is_Phi() ||
3225 n->is_CheckCastPP() ||
3226 n->is_EncodeP() ||
3227 n->is_DecodeN() ||
3228 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3229 if (visited.test_set(n->_idx)) {
3230 assert(n->is_Phi(), "loops only through Phi's");
3231 continue; // already processed
3232 }
3233 JavaObjectNode* jobj = unique_java_object(n);
3234 if (jobj == NULL || jobj == phantom_obj) {
3235 #ifdef ASSERT
3236 ptnode_adr(n->_idx)->dump();
3237 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3238 #endif
3239 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3240 return;
3241 } else {
3242 Node *val = get_map(jobj->idx()); // CheckCastPP node
3243 TypeNode *tn = n->as_Type();
3244 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3245 assert(tinst != NULL && tinst->is_known_instance() &&
3246 tinst->instance_id() == jobj->idx() , "instance type expected.");
3247
3248 const Type *tn_type = igvn->type(tn);
3249 const TypeOopPtr *tn_t;
3250 if (tn_type->isa_narrowoop()) {
3251 tn_t = tn_type->make_ptr()->isa_oopptr();
3252 } else {
3253 tn_t = tn_type->isa_oopptr();
3254 }
3255 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3256 if (tn_type->isa_narrowoop()) {
3257 tn_type = tinst->make_narrowoop();
3258 } else {
3259 tn_type = tinst;
3260 }
3261 igvn->hash_delete(tn);
3262 igvn->set_type(tn, tn_type);
3263 tn->set_type(tn_type);
3264 igvn->hash_insert(tn);
3265 record_for_optimizer(n);
3266 } else {
3267 assert(tn_type == TypePtr::NULL_PTR ||
3268 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3269 "unexpected type");
3270 continue; // Skip dead path with different type
3271 }
3272 }
3273 } else {
3274 debug_only(n->dump();)
3275 assert(false, "EA: unexpected node");
3276 continue;
3277 }
3278 // push allocation's users on appropriate worklist
3279 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3280 Node *use = n->fast_out(i);
3281 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3282 // Load/store to instance's field
3283 memnode_worklist.append_if_missing(use);
3284 } else if (use->is_MemBar()) {
3285 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3286 memnode_worklist.append_if_missing(use);
3287 }
3288 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3289 Node* addp2 = find_second_addp(use, n);
3290 if (addp2 != NULL) {
3291 alloc_worklist.append_if_missing(addp2);
3292 }
3293 alloc_worklist.append_if_missing(use);
3294 } else if (use->is_Phi() ||
3295 use->is_CheckCastPP() ||
3296 use->is_EncodeNarrowPtr() ||
3297 use->is_DecodeNarrowPtr() ||
3298 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3299 alloc_worklist.append_if_missing(use);
3300 #ifdef ASSERT
3301 } else if (use->is_Mem()) {
3302 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3303 } else if (use->is_MergeMem()) {
3304 assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3305 } else if (use->is_SafePoint()) {
3306 // Look for MergeMem nodes for calls which reference unique allocation
3307 // (through CheckCastPP nodes) even for debug info.
3308 Node* m = use->in(TypeFunc::Memory);
3309 if (m->is_MergeMem()) {
3310 assert(mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3311 }
3312 } else if (use->Opcode() == Op_EncodeISOArray) {
3313 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3314 // EncodeISOArray overwrites destination array
3315 memnode_worklist.append_if_missing(use);
3316 }
3317 } else {
3318 uint op = use->Opcode();
3319 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3320 (use->in(MemNode::Memory) == n)) {
3321 // They overwrite memory edge corresponding to destination array,
3322 memnode_worklist.append_if_missing(use);
3323 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3324 op == Op_CastP2X || op == Op_StoreCM ||
3325 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3326 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3327 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3328 op == Op_SubTypeCheck ||
3329 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
3330 n->dump();
3331 use->dump();
3332 assert(false, "EA: missing allocation reference path");
3333 }
3334 #endif
3335 }
3336 }
3337
3338 }
3339
3340 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3341 // type, record it in the ArrayCopy node so we know what memory this
3342 // node uses/modified.
3343 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3344 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3345 Node* dest = ac->in(ArrayCopyNode::Dest);
3346 if (dest->is_AddP()) {
3347 dest = get_addp_base(dest);
3348 }
3349 JavaObjectNode* jobj = unique_java_object(dest);
3350 if (jobj != NULL) {
3351 Node *base = get_map(jobj->idx());
3352 if (base != NULL) {
3353 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3354 ac->_dest_type = base_t;
3355 }
3356 }
3357 Node* src = ac->in(ArrayCopyNode::Src);
3358 if (src->is_AddP()) {
3359 src = get_addp_base(src);
3360 }
3361 jobj = unique_java_object(src);
3362 if (jobj != NULL) {
3363 Node* base = get_map(jobj->idx());
3364 if (base != NULL) {
3365 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3366 ac->_src_type = base_t;
3367 }
3368 }
3369 }
3370
3371 // New alias types were created in split_AddP().
3372 uint new_index_end = (uint) _compile->num_alias_types();
3373 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3374
3375 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3376 // compute new values for Memory inputs (the Memory inputs are not
3377 // actually updated until phase 4.)
3378 if (memnode_worklist.length() == 0)
3379 return; // nothing to do
3380 while (memnode_worklist.length() != 0) {
3381 Node *n = memnode_worklist.pop();
3382 if (visited.test_set(n->_idx)) {
3383 continue;
3384 }
3385 if (n->is_Phi() || n->is_ClearArray()) {
3386 // we don't need to do anything, but the users must be pushed
3387 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3388 // we don't need to do anything, but the users must be pushed
3389 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3390 if (n == NULL) {
3391 continue;
3392 }
3393 } else if (n->Opcode() == Op_StrCompressedCopy ||
3394 n->Opcode() == Op_EncodeISOArray) {
3395 // get the memory projection
3396 n = n->find_out_with(Op_SCMemProj);
3397 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3398 } else {
3399 assert(n->is_Mem(), "memory node required.");
3400 Node *addr = n->in(MemNode::Address);
3401 const Type *addr_t = igvn->type(addr);
3402 if (addr_t == Type::TOP) {
3403 continue;
3404 }
3405 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3406 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3407 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3408 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3409 if (_compile->failing()) {
3410 return;
3411 }
3412 if (mem != n->in(MemNode::Memory)) {
3413 // We delay the memory edge update since we need old one in
3414 // MergeMem code below when instances memory slices are separated.
3415 set_map(n, mem);
3416 }
3417 if (n->is_Load()) {
3418 continue; // don't push users
3419 } else if (n->is_LoadStore()) {
3420 // get the memory projection
3421 n = n->find_out_with(Op_SCMemProj);
3422 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3423 }
3424 }
3425 // push user on appropriate worklist
3426 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3427 Node *use = n->fast_out(i);
3428 if (use->is_Phi() || use->is_ClearArray()) {
3429 memnode_worklist.append_if_missing(use);
3430 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3431 if (use->Opcode() == Op_StoreCM) { // Ignore cardmark stores
3432 continue;
3433 }
3434 memnode_worklist.append_if_missing(use);
3435 } else if (use->is_MemBar()) {
3436 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3437 memnode_worklist.append_if_missing(use);
3438 }
3439 #ifdef ASSERT
3440 } else if(use->is_Mem()) {
3441 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3442 } else if (use->is_MergeMem()) {
3443 assert(mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3444 } else if (use->Opcode() == Op_EncodeISOArray) {
3445 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3446 // EncodeISOArray overwrites destination array
3447 memnode_worklist.append_if_missing(use);
3448 }
3449 } else {
3450 uint op = use->Opcode();
3451 if ((use->in(MemNode::Memory) == n) &&
3452 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3453 // They overwrite memory edge corresponding to destination array,
3454 memnode_worklist.append_if_missing(use);
3455 } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
3456 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3457 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3458 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3459 n->dump();
3460 use->dump();
3461 assert(false, "EA: missing memory path");
3462 }
3463 #endif
3464 }
3465 }
3466 }
3467
3468 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3469 // Walk each memory slice moving the first node encountered of each
3470 // instance type to the the input corresponding to its alias index.
3471 uint length = mergemem_worklist.length();
3472 for( uint next = 0; next < length; ++next ) {
3473 MergeMemNode* nmm = mergemem_worklist.at(next);
3474 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3475 // Note: we don't want to use MergeMemStream here because we only want to
3476 // scan inputs which exist at the start, not ones we add during processing.
3477 // Note 2: MergeMem may already contains instance memory slices added
3478 // during find_inst_mem() call when memory nodes were processed above.
3479 igvn->hash_delete(nmm);
3480 uint nslices = MIN2(nmm->req(), new_index_start);
3481 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3482 Node* mem = nmm->in(i);
3483 Node* cur = NULL;
3484 if (mem == NULL || mem->is_top()) {
3485 continue;
3486 }
3487 // First, update mergemem by moving memory nodes to corresponding slices
3488 // if their type became more precise since this mergemem was created.
3489 while (mem->is_Mem()) {
3490 const Type *at = igvn->type(mem->in(MemNode::Address));
3491 if (at != Type::TOP) {
3492 assert (at->isa_ptr() != NULL, "pointer type required.");
3493 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3494 if (idx == i) {
3495 if (cur == NULL) {
3496 cur = mem;
3497 }
3498 } else {
3499 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3500 nmm->set_memory_at(idx, mem);
3501 }
3502 }
3503 }
3504 mem = mem->in(MemNode::Memory);
3505 }
3506 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3507 // Find any instance of the current type if we haven't encountered
3508 // already a memory slice of the instance along the memory chain.
3509 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3510 if((uint)_compile->get_general_index(ni) == i) {
3511 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3512 if (nmm->is_empty_memory(m)) {
3513 Node* result = find_inst_mem(mem, ni, orig_phis);
3514 if (_compile->failing()) {
3515 return;
3516 }
3517 nmm->set_memory_at(ni, result);
3518 }
3519 }
3520 }
3521 }
3522 // Find the rest of instances values
3523 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3524 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3525 Node* result = step_through_mergemem(nmm, ni, tinst);
3526 if (result == nmm->base_memory()) {
3527 // Didn't find instance memory, search through general slice recursively.
3528 result = nmm->memory_at(_compile->get_general_index(ni));
3529 result = find_inst_mem(result, ni, orig_phis);
3530 if (_compile->failing()) {
3531 return;
3532 }
3533 nmm->set_memory_at(ni, result);
3534 }
3535 }
3536 igvn->hash_insert(nmm);
3537 record_for_optimizer(nmm);
3538 }
3539
3540 // Phase 4: Update the inputs of non-instance memory Phis and
3541 // the Memory input of memnodes
3542 // First update the inputs of any non-instance Phi's from
3543 // which we split out an instance Phi. Note we don't have
3544 // to recursively process Phi's encountered on the input memory
3545 // chains as is done in split_memory_phi() since they will
3546 // also be processed here.
3547 for (int j = 0; j < orig_phis.length(); j++) {
3548 PhiNode *phi = orig_phis.at(j);
3549 int alias_idx = _compile->get_alias_index(phi->adr_type());
3550 igvn->hash_delete(phi);
3551 for (uint i = 1; i < phi->req(); i++) {
3552 Node *mem = phi->in(i);
3553 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3554 if (_compile->failing()) {
3555 return;
3556 }
3557 if (mem != new_mem) {
3558 phi->set_req(i, new_mem);
3559 }
3560 }
3561 igvn->hash_insert(phi);
3562 record_for_optimizer(phi);
3563 }
3564
3565 // Update the memory inputs of MemNodes with the value we computed
3566 // in Phase 2 and move stores memory users to corresponding memory slices.
3567 // Disable memory split verification code until the fix for 6984348.
3568 // Currently it produces false negative results since it does not cover all cases.
3569 #if 0 // ifdef ASSERT
3570 visited.Reset();
3571 Node_Stack old_mems(arena, _compile->unique() >> 2);
3572 #endif
3573 for (uint i = 0; i < ideal_nodes.size(); i++) {
3574 Node* n = ideal_nodes.at(i);
3575 Node* nmem = get_map(n->_idx);
3576 assert(nmem != NULL, "sanity");
3577 if (n->is_Mem()) {
3578 #if 0 // ifdef ASSERT
3579 Node* old_mem = n->in(MemNode::Memory);
3580 if (!visited.test_set(old_mem->_idx)) {
3581 old_mems.push(old_mem, old_mem->outcnt());
3582 }
3583 #endif
3584 assert(n->in(MemNode::Memory) != nmem, "sanity");
3585 if (!n->is_Load()) {
3586 // Move memory users of a store first.
3587 move_inst_mem(n, orig_phis);
3588 }
3589 // Now update memory input
3590 igvn->hash_delete(n);
3591 n->set_req(MemNode::Memory, nmem);
3592 igvn->hash_insert(n);
3593 record_for_optimizer(n);
3594 } else {
3595 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3596 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3597 }
3598 }
3599 #if 0 // ifdef ASSERT
3600 // Verify that memory was split correctly
3601 while (old_mems.is_nonempty()) {
3602 Node* old_mem = old_mems.node();
3603 uint old_cnt = old_mems.index();
3604 old_mems.pop();
3605 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3606 }
3607 #endif
3608 }
3609
3610 #ifndef PRODUCT
3611 static const char *node_type_names[] = {
3612 "UnknownType",
3613 "JavaObject",
3614 "LocalVar",
3615 "Field",
3616 "Arraycopy"
3617 };
3618
3619 static const char *esc_names[] = {
3620 "UnknownEscape",
3621 "NoEscape",
3622 "ArgEscape",
3623 "GlobalEscape"
3624 };
3625
3626 void PointsToNode::dump(bool print_state) const {
3627 NodeType nt = node_type();
3628 tty->print("%s ", node_type_names[(int) nt]);
3629 if (print_state) {
3630 EscapeState es = escape_state();
3631 EscapeState fields_es = fields_escape_state();
3632 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3633 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable()) {
3634 tty->print("NSR ");
3635 }
3636 }
3637 if (is_Field()) {
3638 FieldNode* f = (FieldNode*)this;
3639 if (f->is_oop()) {
3640 tty->print("oop ");
3641 }
3642 if (f->offset() > 0) {
3643 tty->print("+%d ", f->offset());
3644 }
3645 tty->print("(");
3646 for (BaseIterator i(f); i.has_next(); i.next()) {
3647 PointsToNode* b = i.get();
3648 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3649 }
3650 tty->print(" )");
3651 }
3652 tty->print("[");
3653 for (EdgeIterator i(this); i.has_next(); i.next()) {
3654 PointsToNode* e = i.get();
3655 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3656 }
3657 tty->print(" [");
3658 for (UseIterator i(this); i.has_next(); i.next()) {
3659 PointsToNode* u = i.get();
3660 bool is_base = false;
3661 if (PointsToNode::is_base_use(u)) {
3662 is_base = true;
3663 u = PointsToNode::get_use_node(u)->as_Field();
3664 }
3665 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3666 }
3667 tty->print(" ]] ");
3668 if (_node == NULL) {
3669 tty->print_cr("<null>");
3670 } else {
3671 _node->dump();
3672 }
3673 }
3674
3675 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3676 bool first = true;
3677 int ptnodes_length = ptnodes_worklist.length();
3678 for (int i = 0; i < ptnodes_length; i++) {
3679 PointsToNode *ptn = ptnodes_worklist.at(i);
3680 if (ptn == NULL || !ptn->is_JavaObject()) {
3681 continue;
3682 }
3683 PointsToNode::EscapeState es = ptn->escape_state();
3684 if ((es != PointsToNode::NoEscape) && !Verbose) {
3685 continue;
3686 }
3687 Node* n = ptn->ideal_node();
3688 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3689 n->as_CallStaticJava()->is_boxing_method())) {
3690 if (first) {
3691 tty->cr();
3692 tty->print("======== Connection graph for ");
3693 _compile->method()->print_short_name();
3694 tty->cr();
3695 first = false;
3696 }
3697 ptn->dump();
3698 // Print all locals and fields which reference this allocation
3699 for (UseIterator j(ptn); j.has_next(); j.next()) {
3700 PointsToNode* use = j.get();
3701 if (use->is_LocalVar()) {
3702 use->dump(Verbose);
3703 } else if (Verbose) {
3704 use->dump();
3705 }
3706 }
3707 tty->cr();
3708 }
3709 }
3710 }
3711 #endif
3712
3713 void ConnectionGraph::record_for_optimizer(Node *n) {
3714 _igvn->_worklist.push(n);
3715 _igvn->add_users_to_worklist(n);
3716 }