1 /*
2 * Copyright (c) 2005, 2018, 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 _pcmp_neq = NULL; // Should be initialized
67 _pcmp_eq = NULL;
68 }
69
70 bool ConnectionGraph::has_candidates(Compile *C) {
71 // EA brings benefits only when the code has allocations and/or locks which
72 // are represented by ideal Macro nodes.
73 int cnt = C->macro_count();
74 for (int i = 0; i < cnt; i++) {
75 Node *n = C->macro_node(i);
76 if (n->is_Allocate())
77 return true;
78 if (n->is_Lock()) {
79 Node* obj = n->as_Lock()->obj_node()->uncast();
80 if (!(obj->is_Parm() || obj->is_Con()))
81 return true;
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 if (noop_null->outcnt() == 0)
109 igvn->hash_delete(noop_null);
110 }
111
112 bool ConnectionGraph::compute_escape() {
113 Compile* C = _compile;
114 PhaseGVN* igvn = _igvn;
115
116 // Worklists used by EA.
117 Unique_Node_List delayed_worklist;
118 GrowableArray<Node*> alloc_worklist;
119 GrowableArray<Node*> ptr_cmp_worklist;
120 GrowableArray<Node*> storestore_worklist;
121 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
122 GrowableArray<PointsToNode*> ptnodes_worklist;
123 GrowableArray<JavaObjectNode*> java_objects_worklist;
124 GrowableArray<JavaObjectNode*> non_escaped_worklist;
125 GrowableArray<FieldNode*> oop_fields_worklist;
126 GrowableArray<SafePointNode*> sfn_worklist;
127 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
128
129 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
130
131 // 1. Populate Connection Graph (CG) with PointsTo nodes.
132 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
133 // Initialize worklist
134 if (C->root() != NULL) {
135 ideal_nodes.push(C->root());
136 }
137 // Processed ideal nodes are unique on ideal_nodes list
138 // but several ideal nodes are mapped to the phantom_obj.
139 // To avoid duplicated entries on the following worklists
140 // add the phantom_obj only once to them.
141 ptnodes_worklist.append(phantom_obj);
142 java_objects_worklist.append(phantom_obj);
143 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
144 Node* n = ideal_nodes.at(next);
145 // Create PointsTo nodes and add them to Connection Graph. Called
146 // only once per ideal node since ideal_nodes is Unique_Node list.
147 add_node_to_connection_graph(n, &delayed_worklist);
148 PointsToNode* ptn = ptnode_adr(n->_idx);
149 if (ptn != NULL && ptn != phantom_obj) {
150 ptnodes_worklist.append(ptn);
151 if (ptn->is_JavaObject()) {
152 java_objects_worklist.append(ptn->as_JavaObject());
153 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
154 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
155 // Only allocations and java static calls results are interesting.
156 non_escaped_worklist.append(ptn->as_JavaObject());
157 }
158 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
159 oop_fields_worklist.append(ptn->as_Field());
160 }
161 }
162 if (n->is_MergeMem()) {
163 // Collect all MergeMem nodes to add memory slices for
164 // scalar replaceable objects in split_unique_types().
165 _mergemem_worklist.append(n->as_MergeMem());
166 } else if (OptimizePtrCompare && n->is_Cmp() &&
167 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
168 // Collect compare pointers nodes.
169 ptr_cmp_worklist.append(n);
170 } else if (n->is_MemBarStoreStore()) {
171 // Collect all MemBarStoreStore nodes so that depending on the
172 // escape status of the associated Allocate node some of them
173 // may be eliminated.
174 storestore_worklist.append(n);
175 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
176 (n->req() > MemBarNode::Precedent)) {
177 record_for_optimizer(n);
178 #ifdef ASSERT
179 } else if (n->is_AddP()) {
180 // Collect address nodes for graph verification.
181 addp_worklist.append(n);
182 #endif
183 } else if (n->is_ArrayCopy()) {
184 // Keep a list of ArrayCopy nodes so if one of its input is non
185 // escaping, we can record a unique type
186 arraycopy_worklist.append(n->as_ArrayCopy());
187 }
188 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
189 Node* m = n->fast_out(i); // Get user
190 ideal_nodes.push(m);
191 }
192 if (n-> is_SafePoint()) {
193 sfn_worklist.append(n->as_SafePoint());
194 }
195 }
196 if (non_escaped_worklist.length() == 0) {
197 _collecting = false;
198 return false; // Nothing to do.
199 }
200 // Add final simple edges to graph.
201 while(delayed_worklist.size() > 0) {
202 Node* n = delayed_worklist.pop();
203 add_final_edges(n);
204 }
205 int ptnodes_length = ptnodes_worklist.length();
206
207 #ifdef ASSERT
208 if (VerifyConnectionGraph) {
209 // Verify that no new simple edges could be created and all
210 // local vars has edges.
211 _verify = true;
212 for (int next = 0; next < ptnodes_length; ++next) {
213 PointsToNode* ptn = ptnodes_worklist.at(next);
214 add_final_edges(ptn->ideal_node());
215 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
216 ptn->dump();
217 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
218 }
219 }
220 _verify = false;
221 }
222 #endif
223 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
224 // processing, calls to CI to resolve symbols (types, fields, methods)
225 // referenced in bytecode. During symbol resolution VM may throw
226 // an exception which CI cleans and converts to compilation failure.
227 if (C->failing()) return false;
228
229 // 2. Finish Graph construction by propagating references to all
230 // java objects through graph.
231 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
232 java_objects_worklist, oop_fields_worklist)) {
233 // All objects escaped or hit time or iterations limits.
234 _collecting = false;
235 return false;
236 }
237
238 // 3. Adjust scalar_replaceable state of nonescaping objects and push
239 // scalar replaceable allocations on alloc_worklist for processing
240 // in split_unique_types().
241 int non_escaped_length = non_escaped_worklist.length();
242 for (int next = 0; next < non_escaped_length; next++) {
243 JavaObjectNode* ptn = non_escaped_worklist.at(next);
244 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
245 Node* n = ptn->ideal_node();
246 if (n->is_Allocate()) {
247 n->as_Allocate()->_is_non_escaping = noescape;
248 }
249 if (n->is_CallStaticJava()) {
250 n->as_CallStaticJava()->_is_non_escaping = noescape;
251 }
252 if (noescape && ptn->scalar_replaceable()) {
253 adjust_scalar_replaceable_state(ptn);
254 if (ptn->scalar_replaceable()) {
255 alloc_worklist.append(ptn->ideal_node());
256 }
257 }
258 }
259
260 #ifdef ASSERT
261 if (VerifyConnectionGraph) {
262 // Verify that graph is complete - no new edges could be added or needed.
263 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
264 java_objects_worklist, addp_worklist);
265 }
266 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
267 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
268 null_obj->edge_count() == 0 &&
269 !null_obj->arraycopy_src() &&
270 !null_obj->arraycopy_dst(), "sanity");
271 #endif
272
273 _collecting = false;
274
275 } // TracePhase t3("connectionGraph")
276
277 // 4. Optimize ideal graph based on EA information.
278 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
279 if (has_non_escaping_obj) {
280 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
281 }
282
283 #ifndef PRODUCT
284 if (PrintEscapeAnalysis) {
285 dump(ptnodes_worklist); // Dump ConnectionGraph
286 }
287 #endif
288
289 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
290 #ifdef ASSERT
291 if (VerifyConnectionGraph) {
292 int alloc_length = alloc_worklist.length();
293 for (int next = 0; next < alloc_length; ++next) {
294 Node* n = alloc_worklist.at(next);
295 PointsToNode* ptn = ptnode_adr(n->_idx);
296 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
297 }
298 }
299 #endif
300
301 // 5. Separate memory graph for scalar replaceable allcations.
302 if (has_scalar_replaceable_candidates &&
303 C->AliasLevel() >= 3 && EliminateAllocations) {
304 // Now use the escape information to create unique types for
305 // scalar replaceable objects.
306 split_unique_types(alloc_worklist, arraycopy_worklist);
307 if (C->failing()) return false;
308 C->print_method(PHASE_AFTER_EA, 2);
309
310 #ifdef ASSERT
311 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
312 tty->print("=== No allocations eliminated for ");
313 C->method()->print_short_name();
314 if(!EliminateAllocations) {
315 tty->print(" since EliminateAllocations is off ===");
316 } else if(!has_scalar_replaceable_candidates) {
317 tty->print(" since there are no scalar replaceable candidates ===");
318 } else if(C->AliasLevel() < 3) {
319 tty->print(" since AliasLevel < 3 ===");
320 }
321 tty->cr();
322 #endif
323 }
324
325 // Annotate at safepoints if they have <= ArgEscape objects in their scope and at
326 // java calls if they pass ArgEscape objects as parameters.
327 if (has_non_escaping_obj &&
328 (C->env()->should_retain_local_variables() ||
329 C->env()->jvmti_can_get_owned_monitor_info() ||
330 C->env()->jvmti_can_walk_any_space() ||
331 DeoptimizeObjectsALot)) {
332 int sfn_length = sfn_worklist.length();
333 for (int next = 0; next < sfn_length; next++) {
334 SafePointNode* sfn = sfn_worklist.at(next);
335 bool found_not_global_escape = false;
336 for (JVMState* jvms = sfn->jvms(); jvms && !found_not_global_escape; jvms = jvms->caller()) {
337 if (C->env()->should_retain_local_variables() || C->env()->jvmti_can_walk_any_space() ||
338 DeoptimizeObjectsALot) {
339 // Jvmti agents can access locals. Must provide info about local objects at runtime.
340 int num_locs = jvms->loc_size();
341 for(int idx = 0; idx < num_locs && !found_not_global_escape; idx++ ) {
342 Node* l = sfn->local(jvms, idx);
343 found_not_global_escape = not_global_escape(l);
344 }
345 }
346 if (C->env()->jvmti_can_get_owned_monitor_info() ||
347 C->env()->jvmti_can_walk_any_space() || DeoptimizeObjectsALot) {
348 // Jvmti agents can read monitors. Must provide info about locked objects at runtime.
349 int num_mon = jvms->nof_monitors();
350 for(int idx = 0; idx < num_mon && !found_not_global_escape; idx++ ) {
351 Node* m = sfn->monitor_obj(jvms, idx);
352 found_not_global_escape = m != NULL && not_global_escape(m);
353 }
354 }
355 }
356 sfn->set_not_global_escape_in_scope(found_not_global_escape);
357
358 if (sfn->is_CallJava()) {
359 CallJavaNode* call = sfn->as_CallJava();
360 bool found_arg_escape_in_args = false;
361 if (call->method() != NULL) {
362 uint max_idx = TypeFunc::Parms + call->method()->arg_size();
363 for(uint idx = TypeFunc::Parms; idx < max_idx && !found_arg_escape_in_args; idx++) {
364 Node* p = call->in(idx);
365 found_arg_escape_in_args = not_global_escape(p);
366 }
367 } else {
368 const char* name = call->as_CallStaticJava()->_name;
369 assert(name != NULL, "no name");
370 // no arg escapes through uncommon traps
371 if (strcmp(name, "uncommon_trap") != 0) {
372 // process_call_arguments() assumes that all arguments escape globally
373 const TypeTuple* d = call->tf()->domain();
374 for (uint i = TypeFunc::Parms; i < d->cnt() && !found_arg_escape_in_args; i++) {
375 const Type* at = d->field_at(i);
376 if (at->isa_oopptr() != NULL) {
377 found_arg_escape_in_args = true;
378 }
379 }
380 }
381 }
382 call->set_arg_escape(found_arg_escape_in_args);
383 }
384 }
385 }
386
387 return has_non_escaping_obj;
388 }
389
390 // Utility function for nodes that load an object
391 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
392 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
393 // ThreadLocal has RawPtr type.
394 const Type* t = _igvn->type(n);
395 if (t->make_ptr() != NULL) {
396 Node* adr = n->in(MemNode::Address);
397 #ifdef ASSERT
398 if (!adr->is_AddP()) {
399 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
400 } else {
401 assert((ptnode_adr(adr->_idx) == NULL ||
402 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
403 }
404 #endif
405 add_local_var_and_edge(n, PointsToNode::NoEscape,
406 adr, delayed_worklist);
407 }
408 }
409
410 // Populate Connection Graph with PointsTo nodes and create simple
411 // connection graph edges.
412 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
413 assert(!_verify, "this method should not be called for verification");
414 PhaseGVN* igvn = _igvn;
415 uint n_idx = n->_idx;
416 PointsToNode* n_ptn = ptnode_adr(n_idx);
417 if (n_ptn != NULL)
418 return; // No need to redefine PointsTo node during first iteration.
419
420 int opcode = n->Opcode();
421 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
422 if (gc_handled) {
423 return; // Ignore node if already handled by GC.
424 }
425
426 if (n->is_Call()) {
427 // Arguments to allocation and locking don't escape.
428 if (n->is_AbstractLock()) {
429 // Put Lock and Unlock nodes on IGVN worklist to process them during
430 // first IGVN optimization when escape information is still available.
431 record_for_optimizer(n);
432 } else if (n->is_Allocate()) {
433 add_call_node(n->as_Call());
434 record_for_optimizer(n);
435 } else {
436 if (n->is_CallStaticJava()) {
437 const char* name = n->as_CallStaticJava()->_name;
438 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
439 return; // Skip uncommon traps
440 }
441 // Don't mark as processed since call's arguments have to be processed.
442 delayed_worklist->push(n);
443 // Check if a call returns an object.
444 if ((n->as_Call()->returns_pointer() &&
445 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
446 (n->is_CallStaticJava() &&
447 n->as_CallStaticJava()->is_boxing_method())) {
448 add_call_node(n->as_Call());
449 }
450 }
451 return;
452 }
453 // Put this check here to process call arguments since some call nodes
454 // point to phantom_obj.
455 if (n_ptn == phantom_obj || n_ptn == null_obj)
456 return; // Skip predefined nodes.
457
458 switch (opcode) {
459 case Op_AddP: {
460 Node* base = get_addp_base(n);
461 PointsToNode* ptn_base = ptnode_adr(base->_idx);
462 // Field nodes are created for all field types. They are used in
463 // adjust_scalar_replaceable_state() and split_unique_types().
464 // Note, non-oop fields will have only base edges in Connection
465 // Graph because such fields are not used for oop loads and stores.
466 int offset = address_offset(n, igvn);
467 add_field(n, PointsToNode::NoEscape, offset);
468 if (ptn_base == NULL) {
469 delayed_worklist->push(n); // Process it later.
470 } else {
471 n_ptn = ptnode_adr(n_idx);
472 add_base(n_ptn->as_Field(), ptn_base);
473 }
474 break;
475 }
476 case Op_CastX2P: {
477 map_ideal_node(n, phantom_obj);
478 break;
479 }
480 case Op_CastPP:
481 case Op_CheckCastPP:
482 case Op_EncodeP:
483 case Op_DecodeN:
484 case Op_EncodePKlass:
485 case Op_DecodeNKlass: {
486 add_local_var_and_edge(n, PointsToNode::NoEscape,
487 n->in(1), delayed_worklist);
488 break;
489 }
490 case Op_CMoveP: {
491 add_local_var(n, PointsToNode::NoEscape);
492 // Do not add edges during first iteration because some could be
493 // not defined yet.
494 delayed_worklist->push(n);
495 break;
496 }
497 case Op_ConP:
498 case Op_ConN:
499 case Op_ConNKlass: {
500 // assume all oop constants globally escape except for null
501 PointsToNode::EscapeState es;
502 const Type* t = igvn->type(n);
503 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
504 es = PointsToNode::NoEscape;
505 } else {
506 es = PointsToNode::GlobalEscape;
507 }
508 add_java_object(n, es);
509 break;
510 }
511 case Op_CreateEx: {
512 // assume that all exception objects globally escape
513 map_ideal_node(n, phantom_obj);
514 break;
515 }
516 case Op_LoadKlass:
517 case Op_LoadNKlass: {
518 // Unknown class is loaded
519 map_ideal_node(n, phantom_obj);
520 break;
521 }
522 case Op_LoadP:
523 case Op_LoadN:
524 case Op_LoadPLocked: {
525 add_objload_to_connection_graph(n, delayed_worklist);
526 break;
527 }
528 case Op_Parm: {
529 map_ideal_node(n, phantom_obj);
530 break;
531 }
532 case Op_PartialSubtypeCheck: {
533 // Produces Null or notNull and is used in only in CmpP so
534 // phantom_obj could be used.
535 map_ideal_node(n, phantom_obj); // Result is unknown
536 break;
537 }
538 case Op_Phi: {
539 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
540 // ThreadLocal has RawPtr type.
541 const Type* t = n->as_Phi()->type();
542 if (t->make_ptr() != NULL) {
543 add_local_var(n, PointsToNode::NoEscape);
544 // Do not add edges during first iteration because some could be
545 // not defined yet.
546 delayed_worklist->push(n);
547 }
548 break;
549 }
550 case Op_Proj: {
551 // we are only interested in the oop result projection from a call
552 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
553 n->in(0)->as_Call()->returns_pointer()) {
554 add_local_var_and_edge(n, PointsToNode::NoEscape,
555 n->in(0), delayed_worklist);
556 }
557 break;
558 }
559 case Op_Rethrow: // Exception object escapes
560 case Op_Return: {
561 if (n->req() > TypeFunc::Parms &&
562 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
563 // Treat Return value as LocalVar with GlobalEscape escape state.
564 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
565 n->in(TypeFunc::Parms), delayed_worklist);
566 }
567 break;
568 }
569 case Op_CompareAndExchangeP:
570 case Op_CompareAndExchangeN:
571 case Op_GetAndSetP:
572 case Op_GetAndSetN: {
573 add_objload_to_connection_graph(n, delayed_worklist);
574 // fallthrough
575 }
576 case Op_StoreP:
577 case Op_StoreN:
578 case Op_StoreNKlass:
579 case Op_StorePConditional:
580 case Op_WeakCompareAndSwapP:
581 case Op_WeakCompareAndSwapN:
582 case Op_CompareAndSwapP:
583 case Op_CompareAndSwapN: {
584 add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
585 break;
586 }
587 case Op_AryEq:
588 case Op_HasNegatives:
589 case Op_StrComp:
590 case Op_StrEquals:
591 case Op_StrIndexOf:
592 case Op_StrIndexOfChar:
593 case Op_StrInflatedCopy:
594 case Op_StrCompressedCopy:
595 case Op_EncodeISOArray: {
596 add_local_var(n, PointsToNode::ArgEscape);
597 delayed_worklist->push(n); // Process it later.
598 break;
599 }
600 case Op_ThreadLocal: {
601 add_java_object(n, PointsToNode::ArgEscape);
602 break;
603 }
604 default:
605 ; // Do nothing for nodes not related to EA.
606 }
607 return;
608 }
609
610 #ifdef ASSERT
611 #define ELSE_FAIL(name) \
612 /* Should not be called for not pointer type. */ \
613 n->dump(1); \
614 assert(false, name); \
615 break;
616 #else
617 #define ELSE_FAIL(name) \
618 break;
619 #endif
620
621 // Add final simple edges to graph.
622 void ConnectionGraph::add_final_edges(Node *n) {
623 PointsToNode* n_ptn = ptnode_adr(n->_idx);
624 #ifdef ASSERT
625 if (_verify && n_ptn->is_JavaObject())
626 return; // This method does not change graph for JavaObject.
627 #endif
628
629 if (n->is_Call()) {
630 process_call_arguments(n->as_Call());
631 return;
632 }
633 assert(n->is_Store() || n->is_LoadStore() ||
634 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
635 "node should be registered already");
636 int opcode = n->Opcode();
637 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
638 if (gc_handled) {
639 return; // Ignore node if already handled by GC.
640 }
641 switch (opcode) {
642 case Op_AddP: {
643 Node* base = get_addp_base(n);
644 PointsToNode* ptn_base = ptnode_adr(base->_idx);
645 assert(ptn_base != NULL, "field's base should be registered");
646 add_base(n_ptn->as_Field(), ptn_base);
647 break;
648 }
649 case Op_CastPP:
650 case Op_CheckCastPP:
651 case Op_EncodeP:
652 case Op_DecodeN:
653 case Op_EncodePKlass:
654 case Op_DecodeNKlass: {
655 add_local_var_and_edge(n, PointsToNode::NoEscape,
656 n->in(1), NULL);
657 break;
658 }
659 case Op_CMoveP: {
660 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
661 Node* in = n->in(i);
662 if (in == NULL)
663 continue; // ignore NULL
664 Node* uncast_in = in->uncast();
665 if (uncast_in->is_top() || uncast_in == n)
666 continue; // ignore top or inputs which go back this node
667 PointsToNode* ptn = ptnode_adr(in->_idx);
668 assert(ptn != NULL, "node should be registered");
669 add_edge(n_ptn, ptn);
670 }
671 break;
672 }
673 case Op_LoadP:
674 case Op_LoadN:
675 case Op_LoadPLocked: {
676 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
677 // ThreadLocal has RawPtr type.
678 const Type* t = _igvn->type(n);
679 if (t->make_ptr() != NULL) {
680 Node* adr = n->in(MemNode::Address);
681 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
682 break;
683 }
684 ELSE_FAIL("Op_LoadP");
685 }
686 case Op_Phi: {
687 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
688 // ThreadLocal has RawPtr type.
689 const Type* t = n->as_Phi()->type();
690 if (t->make_ptr() != NULL) {
691 for (uint i = 1; i < n->req(); i++) {
692 Node* in = n->in(i);
693 if (in == NULL)
694 continue; // ignore NULL
695 Node* uncast_in = in->uncast();
696 if (uncast_in->is_top() || uncast_in == n)
697 continue; // ignore top or inputs which go back this node
698 PointsToNode* ptn = ptnode_adr(in->_idx);
699 assert(ptn != NULL, "node should be registered");
700 add_edge(n_ptn, ptn);
701 }
702 break;
703 }
704 ELSE_FAIL("Op_Phi");
705 }
706 case Op_Proj: {
707 // we are only interested in the oop result projection from a call
708 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
709 n->in(0)->as_Call()->returns_pointer()) {
710 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
711 break;
712 }
713 ELSE_FAIL("Op_Proj");
714 }
715 case Op_Rethrow: // Exception object escapes
716 case Op_Return: {
717 if (n->req() > TypeFunc::Parms &&
718 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
719 // Treat Return value as LocalVar with GlobalEscape escape state.
720 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
721 n->in(TypeFunc::Parms), NULL);
722 break;
723 }
724 ELSE_FAIL("Op_Return");
725 }
726 case Op_StoreP:
727 case Op_StoreN:
728 case Op_StoreNKlass:
729 case Op_StorePConditional:
730 case Op_CompareAndExchangeP:
731 case Op_CompareAndExchangeN:
732 case Op_CompareAndSwapP:
733 case Op_CompareAndSwapN:
734 case Op_WeakCompareAndSwapP:
735 case Op_WeakCompareAndSwapN:
736 case Op_GetAndSetP:
737 case Op_GetAndSetN: {
738 if (add_final_edges_unsafe_access(n, opcode)) {
739 break;
740 }
741 ELSE_FAIL("Op_StoreP");
742 }
743 case Op_AryEq:
744 case Op_HasNegatives:
745 case Op_StrComp:
746 case Op_StrEquals:
747 case Op_StrIndexOf:
748 case Op_StrIndexOfChar:
749 case Op_StrInflatedCopy:
750 case Op_StrCompressedCopy:
751 case Op_EncodeISOArray: {
752 // char[]/byte[] arrays passed to string intrinsic do not escape but
753 // they are not scalar replaceable. Adjust escape state for them.
754 // Start from in(2) edge since in(1) is memory edge.
755 for (uint i = 2; i < n->req(); i++) {
756 Node* adr = n->in(i);
757 const Type* at = _igvn->type(adr);
758 if (!adr->is_top() && at->isa_ptr()) {
759 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
760 at->isa_ptr() != NULL, "expecting a pointer");
761 if (adr->is_AddP()) {
762 adr = get_addp_base(adr);
763 }
764 PointsToNode* ptn = ptnode_adr(adr->_idx);
765 assert(ptn != NULL, "node should be registered");
766 add_edge(n_ptn, ptn);
767 }
768 }
769 break;
770 }
771 default: {
772 // This method should be called only for EA specific nodes which may
773 // miss some edges when they were created.
774 #ifdef ASSERT
775 n->dump(1);
776 #endif
777 guarantee(false, "unknown node");
778 }
779 }
780 return;
781 }
782
783 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
784 Node* adr = n->in(MemNode::Address);
785 const Type* adr_type = _igvn->type(adr);
786 adr_type = adr_type->make_ptr();
787 if (adr_type == NULL) {
788 return; // skip dead nodes
789 }
790 if (adr_type->isa_oopptr()
791 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
792 && adr_type == TypeRawPtr::NOTNULL
793 && adr->in(AddPNode::Address)->is_Proj()
794 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
795 delayed_worklist->push(n); // Process it later.
796 #ifdef ASSERT
797 assert (adr->is_AddP(), "expecting an AddP");
798 if (adr_type == TypeRawPtr::NOTNULL) {
799 // Verify a raw address for a store captured by Initialize node.
800 int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
801 assert(offs != Type::OffsetBot, "offset must be a constant");
802 }
803 #endif
804 } else {
805 // Ignore copy the displaced header to the BoxNode (OSR compilation).
806 if (adr->is_BoxLock()) {
807 return;
808 }
809 // Stored value escapes in unsafe access.
810 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
811 delayed_worklist->push(n); // Process unsafe access later.
812 return;
813 }
814 #ifdef ASSERT
815 n->dump(1);
816 assert(false, "not unsafe");
817 #endif
818 }
819 }
820
821 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
822 Node* adr = n->in(MemNode::Address);
823 const Type *adr_type = _igvn->type(adr);
824 adr_type = adr_type->make_ptr();
825 #ifdef ASSERT
826 if (adr_type == NULL) {
827 n->dump(1);
828 assert(adr_type != NULL, "dead node should not be on list");
829 return true;
830 }
831 #endif
832
833 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
834 opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
835 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
836 }
837
838 if (adr_type->isa_oopptr()
839 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
840 && adr_type == TypeRawPtr::NOTNULL
841 && adr->in(AddPNode::Address)->is_Proj()
842 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
843 // Point Address to Value
844 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
845 assert(adr_ptn != NULL &&
846 adr_ptn->as_Field()->is_oop(), "node should be registered");
847 Node* val = n->in(MemNode::ValueIn);
848 PointsToNode* ptn = ptnode_adr(val->_idx);
849 assert(ptn != NULL, "node should be registered");
850 add_edge(adr_ptn, ptn);
851 return true;
852 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
853 // Stored value escapes in unsafe access.
854 Node* val = n->in(MemNode::ValueIn);
855 PointsToNode* ptn = ptnode_adr(val->_idx);
856 assert(ptn != NULL, "node should be registered");
857 set_escape_state(ptn, PointsToNode::GlobalEscape);
858 // Add edge to object for unsafe access with offset.
859 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
860 assert(adr_ptn != NULL, "node should be registered");
861 if (adr_ptn->is_Field()) {
862 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
863 add_edge(adr_ptn, ptn);
864 }
865 return true;
866 }
867 return false;
868 }
869
870 void ConnectionGraph::add_call_node(CallNode* call) {
871 assert(call->returns_pointer(), "only for call which returns pointer");
872 uint call_idx = call->_idx;
873 if (call->is_Allocate()) {
874 Node* k = call->in(AllocateNode::KlassNode);
875 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
876 assert(kt != NULL, "TypeKlassPtr required.");
877 ciKlass* cik = kt->klass();
878 PointsToNode::EscapeState es = PointsToNode::NoEscape;
879 bool scalar_replaceable = true;
880 if (call->is_AllocateArray()) {
881 if (!cik->is_array_klass()) { // StressReflectiveCode
882 es = PointsToNode::GlobalEscape;
883 } else {
884 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
885 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
886 // Not scalar replaceable if the length is not constant or too big.
887 scalar_replaceable = false;
888 }
889 }
890 } else { // Allocate instance
891 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
892 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
893 !cik->is_instance_klass() || // StressReflectiveCode
894 !cik->as_instance_klass()->can_be_instantiated() ||
895 cik->as_instance_klass()->has_finalizer()) {
896 es = PointsToNode::GlobalEscape;
897 }
898 }
899 add_java_object(call, es);
900 PointsToNode* ptn = ptnode_adr(call_idx);
901 if (!scalar_replaceable && ptn->scalar_replaceable()) {
902 ptn->set_scalar_replaceable(false);
903 }
904 } else if (call->is_CallStaticJava()) {
905 // Call nodes could be different types:
906 //
907 // 1. CallDynamicJavaNode (what happened during call is unknown):
908 //
909 // - mapped to GlobalEscape JavaObject node if oop is returned;
910 //
911 // - all oop arguments are escaping globally;
912 //
913 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
914 //
915 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
916 //
917 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
918 // - mapped to NoEscape JavaObject node if non-escaping object allocated
919 // during call is returned;
920 // - mapped to ArgEscape LocalVar node pointed to object arguments
921 // which are returned and does not escape during call;
922 //
923 // - oop arguments escaping status is defined by bytecode analysis;
924 //
925 // For a static call, we know exactly what method is being called.
926 // Use bytecode estimator to record whether the call's return value escapes.
927 ciMethod* meth = call->as_CallJava()->method();
928 if (meth == NULL) {
929 const char* name = call->as_CallStaticJava()->_name;
930 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
931 // Returns a newly allocated unescaped object.
932 add_java_object(call, PointsToNode::NoEscape);
933 ptnode_adr(call_idx)->set_scalar_replaceable(false);
934 } else if (meth->is_boxing_method()) {
935 // Returns boxing object
936 PointsToNode::EscapeState es;
937 vmIntrinsics::ID intr = meth->intrinsic_id();
938 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
939 // It does not escape if object is always allocated.
940 es = PointsToNode::NoEscape;
941 } else {
942 // It escapes globally if object could be loaded from cache.
943 es = PointsToNode::GlobalEscape;
944 }
945 add_java_object(call, es);
946 } else {
947 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
948 call_analyzer->copy_dependencies(_compile->dependencies());
949 if (call_analyzer->is_return_allocated()) {
950 // Returns a newly allocated unescaped object, simply
951 // update dependency information.
952 // Mark it as NoEscape so that objects referenced by
953 // it's fields will be marked as NoEscape at least.
954 add_java_object(call, PointsToNode::NoEscape);
955 ptnode_adr(call_idx)->set_scalar_replaceable(false);
956 } else {
957 // Determine whether any arguments are returned.
958 const TypeTuple* d = call->tf()->domain();
959 bool ret_arg = false;
960 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
961 if (d->field_at(i)->isa_ptr() != NULL &&
962 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
963 ret_arg = true;
964 break;
965 }
966 }
967 if (ret_arg) {
968 add_local_var(call, PointsToNode::ArgEscape);
969 } else {
970 // Returns unknown object.
971 map_ideal_node(call, phantom_obj);
972 }
973 }
974 }
975 } else {
976 // An other type of call, assume the worst case:
977 // returned value is unknown and globally escapes.
978 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
979 map_ideal_node(call, phantom_obj);
980 }
981 }
982
983 void ConnectionGraph::process_call_arguments(CallNode *call) {
984 bool is_arraycopy = false;
985 switch (call->Opcode()) {
986 #ifdef ASSERT
987 case Op_Allocate:
988 case Op_AllocateArray:
989 case Op_Lock:
990 case Op_Unlock:
991 assert(false, "should be done already");
992 break;
993 #endif
994 case Op_ArrayCopy:
995 case Op_CallLeafNoFP:
996 // Most array copies are ArrayCopy nodes at this point but there
997 // are still a few direct calls to the copy subroutines (See
998 // PhaseStringOpts::copy_string())
999 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
1000 call->as_CallLeaf()->is_call_to_arraycopystub();
1001 // fall through
1002 case Op_CallLeaf: {
1003 // Stub calls, objects do not escape but they are not scale replaceable.
1004 // Adjust escape state for outgoing arguments.
1005 const TypeTuple * d = call->tf()->domain();
1006 bool src_has_oops = false;
1007 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1008 const Type* at = d->field_at(i);
1009 Node *arg = call->in(i);
1010 if (arg == NULL) {
1011 continue;
1012 }
1013 const Type *aat = _igvn->type(arg);
1014 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
1015 continue;
1016 if (arg->is_AddP()) {
1017 //
1018 // The inline_native_clone() case when the arraycopy stub is called
1019 // after the allocation before Initialize and CheckCastPP nodes.
1020 // Or normal arraycopy for object arrays case.
1021 //
1022 // Set AddP's base (Allocate) as not scalar replaceable since
1023 // pointer to the base (with offset) is passed as argument.
1024 //
1025 arg = get_addp_base(arg);
1026 }
1027 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1028 assert(arg_ptn != NULL, "should be registered");
1029 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
1030 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
1031 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1032 aat->isa_ptr() != NULL, "expecting an Ptr");
1033 bool arg_has_oops = aat->isa_oopptr() &&
1034 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
1035 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
1036 if (i == TypeFunc::Parms) {
1037 src_has_oops = arg_has_oops;
1038 }
1039 //
1040 // src or dst could be j.l.Object when other is basic type array:
1041 //
1042 // arraycopy(char[],0,Object*,0,size);
1043 // arraycopy(Object*,0,char[],0,size);
1044 //
1045 // Don't add edges in such cases.
1046 //
1047 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
1048 arg_has_oops && (i > TypeFunc::Parms);
1049 #ifdef ASSERT
1050 if (!(is_arraycopy ||
1051 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
1052 (call->as_CallLeaf()->_name != NULL &&
1053 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
1054 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
1055 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
1056 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
1057 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
1058 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
1059 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
1060 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_encryptAESCrypt") == 0 ||
1061 strcmp(call->as_CallLeaf()->_name, "electronicCodeBook_decryptAESCrypt") == 0 ||
1062 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
1063 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
1064 strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
1065 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
1066 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
1067 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
1068 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
1069 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1070 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1071 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1072 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1073 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1074 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1075 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1076 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1077 ))) {
1078 call->dump();
1079 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1080 }
1081 #endif
1082 // Always process arraycopy's destination object since
1083 // we need to add all possible edges to references in
1084 // source object.
1085 if (arg_esc >= PointsToNode::ArgEscape &&
1086 !arg_is_arraycopy_dest) {
1087 continue;
1088 }
1089 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1090 if (call->is_ArrayCopy()) {
1091 ArrayCopyNode* ac = call->as_ArrayCopy();
1092 if (ac->is_clonebasic() ||
1093 ac->is_arraycopy_validated() ||
1094 ac->is_copyof_validated() ||
1095 ac->is_copyofrange_validated()) {
1096 es = PointsToNode::NoEscape;
1097 }
1098 }
1099 set_escape_state(arg_ptn, es);
1100 if (arg_is_arraycopy_dest) {
1101 Node* src = call->in(TypeFunc::Parms);
1102 if (src->is_AddP()) {
1103 src = get_addp_base(src);
1104 }
1105 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1106 assert(src_ptn != NULL, "should be registered");
1107 if (arg_ptn != src_ptn) {
1108 // Special arraycopy edge:
1109 // A destination object's field can't have the source object
1110 // as base since objects escape states are not related.
1111 // Only escape state of destination object's fields affects
1112 // escape state of fields in source object.
1113 add_arraycopy(call, es, src_ptn, arg_ptn);
1114 }
1115 }
1116 }
1117 }
1118 break;
1119 }
1120 case Op_CallStaticJava: {
1121 // For a static call, we know exactly what method is being called.
1122 // Use bytecode estimator to record the call's escape affects
1123 #ifdef ASSERT
1124 const char* name = call->as_CallStaticJava()->_name;
1125 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1126 #endif
1127 ciMethod* meth = call->as_CallJava()->method();
1128 if ((meth != NULL) && meth->is_boxing_method()) {
1129 break; // Boxing methods do not modify any oops.
1130 }
1131 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1132 // fall-through if not a Java method or no analyzer information
1133 if (call_analyzer != NULL) {
1134 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1135 const TypeTuple* d = call->tf()->domain();
1136 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1137 const Type* at = d->field_at(i);
1138 int k = i - TypeFunc::Parms;
1139 Node* arg = call->in(i);
1140 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1141 if (at->isa_ptr() != NULL &&
1142 call_analyzer->is_arg_returned(k)) {
1143 // The call returns arguments.
1144 if (call_ptn != NULL) { // Is call's result used?
1145 assert(call_ptn->is_LocalVar(), "node should be registered");
1146 assert(arg_ptn != NULL, "node should be registered");
1147 add_edge(call_ptn, arg_ptn);
1148 }
1149 }
1150 if (at->isa_oopptr() != NULL &&
1151 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1152 if (!call_analyzer->is_arg_stack(k)) {
1153 // The argument global escapes
1154 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1155 } else {
1156 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1157 if (!call_analyzer->is_arg_local(k)) {
1158 // The argument itself doesn't escape, but any fields might
1159 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1160 }
1161 }
1162 }
1163 }
1164 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1165 // The call returns arguments.
1166 assert(call_ptn->edge_count() > 0, "sanity");
1167 if (!call_analyzer->is_return_local()) {
1168 // Returns also unknown object.
1169 add_edge(call_ptn, phantom_obj);
1170 }
1171 }
1172 break;
1173 }
1174 }
1175 default: {
1176 // Fall-through here if not a Java method or no analyzer information
1177 // or some other type of call, assume the worst case: all arguments
1178 // globally escape.
1179 const TypeTuple* d = call->tf()->domain();
1180 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1181 const Type* at = d->field_at(i);
1182 if (at->isa_oopptr() != NULL) {
1183 Node* arg = call->in(i);
1184 if (arg->is_AddP()) {
1185 arg = get_addp_base(arg);
1186 }
1187 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1188 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1189 }
1190 }
1191 }
1192 }
1193 }
1194
1195
1196 // Finish Graph construction.
1197 bool ConnectionGraph::complete_connection_graph(
1198 GrowableArray<PointsToNode*>& ptnodes_worklist,
1199 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1200 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1201 GrowableArray<FieldNode*>& oop_fields_worklist) {
1202 // Normally only 1-3 passes needed to build Connection Graph depending
1203 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1204 // Set limit to 20 to catch situation when something did go wrong and
1205 // bailout Escape Analysis.
1206 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1207 #define CG_BUILD_ITER_LIMIT 20
1208
1209 // Propagate GlobalEscape and ArgEscape escape states and check that
1210 // we still have non-escaping objects. The method pushs on _worklist
1211 // Field nodes which reference phantom_object.
1212 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1213 return false; // Nothing to do.
1214 }
1215 // Now propagate references to all JavaObject nodes.
1216 int java_objects_length = java_objects_worklist.length();
1217 elapsedTimer time;
1218 bool timeout = false;
1219 int new_edges = 1;
1220 int iterations = 0;
1221 do {
1222 while ((new_edges > 0) &&
1223 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1224 double start_time = time.seconds();
1225 time.start();
1226 new_edges = 0;
1227 // Propagate references to phantom_object for nodes pushed on _worklist
1228 // by find_non_escaped_objects() and find_field_value().
1229 new_edges += add_java_object_edges(phantom_obj, false);
1230 for (int next = 0; next < java_objects_length; ++next) {
1231 JavaObjectNode* ptn = java_objects_worklist.at(next);
1232 new_edges += add_java_object_edges(ptn, true);
1233
1234 #define SAMPLE_SIZE 4
1235 if ((next % SAMPLE_SIZE) == 0) {
1236 // Each 4 iterations calculate how much time it will take
1237 // to complete graph construction.
1238 time.stop();
1239 // Poll for requests from shutdown mechanism to quiesce compiler
1240 // because Connection graph construction may take long time.
1241 CompileBroker::maybe_block();
1242 double stop_time = time.seconds();
1243 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1244 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1245 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1246 timeout = true;
1247 break; // Timeout
1248 }
1249 start_time = stop_time;
1250 time.start();
1251 }
1252 #undef SAMPLE_SIZE
1253
1254 }
1255 if (timeout) break;
1256 if (new_edges > 0) {
1257 // Update escape states on each iteration if graph was updated.
1258 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1259 return false; // Nothing to do.
1260 }
1261 }
1262 time.stop();
1263 if (time.seconds() >= EscapeAnalysisTimeout) {
1264 timeout = true;
1265 break;
1266 }
1267 }
1268 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1269 time.start();
1270 // Find fields which have unknown value.
1271 int fields_length = oop_fields_worklist.length();
1272 for (int next = 0; next < fields_length; next++) {
1273 FieldNode* field = oop_fields_worklist.at(next);
1274 if (field->edge_count() == 0) {
1275 new_edges += find_field_value(field);
1276 // This code may added new edges to phantom_object.
1277 // Need an other cycle to propagate references to phantom_object.
1278 }
1279 }
1280 time.stop();
1281 if (time.seconds() >= EscapeAnalysisTimeout) {
1282 timeout = true;
1283 break;
1284 }
1285 } else {
1286 new_edges = 0; // Bailout
1287 }
1288 } while (new_edges > 0);
1289
1290 // Bailout if passed limits.
1291 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1292 Compile* C = _compile;
1293 if (C->log() != NULL) {
1294 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1295 C->log()->text("%s", timeout ? "time" : "iterations");
1296 C->log()->end_elem(" limit'");
1297 }
1298 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1299 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1300 // Possible infinite build_connection_graph loop,
1301 // bailout (no changes to ideal graph were made).
1302 return false;
1303 }
1304 #ifdef ASSERT
1305 if (Verbose && PrintEscapeAnalysis) {
1306 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1307 iterations, nodes_size(), ptnodes_worklist.length());
1308 }
1309 #endif
1310
1311 #undef CG_BUILD_ITER_LIMIT
1312
1313 // Find fields initialized by NULL for non-escaping Allocations.
1314 int non_escaped_length = non_escaped_worklist.length();
1315 for (int next = 0; next < non_escaped_length; next++) {
1316 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1317 PointsToNode::EscapeState es = ptn->escape_state();
1318 assert(es <= PointsToNode::ArgEscape, "sanity");
1319 if (es == PointsToNode::NoEscape) {
1320 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1321 // Adding references to NULL object does not change escape states
1322 // since it does not escape. Also no fields are added to NULL object.
1323 add_java_object_edges(null_obj, false);
1324 }
1325 }
1326 Node* n = ptn->ideal_node();
1327 if (n->is_Allocate()) {
1328 // The object allocated by this Allocate node will never be
1329 // seen by an other thread. Mark it so that when it is
1330 // expanded no MemBarStoreStore is added.
1331 InitializeNode* ini = n->as_Allocate()->initialization();
1332 if (ini != NULL)
1333 ini->set_does_not_escape();
1334 }
1335 }
1336 return true; // Finished graph construction.
1337 }
1338
1339 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1340 // and check that we still have non-escaping java objects.
1341 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1342 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1343 GrowableArray<PointsToNode*> escape_worklist;
1344 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1345 int ptnodes_length = ptnodes_worklist.length();
1346 for (int next = 0; next < ptnodes_length; ++next) {
1347 PointsToNode* ptn = ptnodes_worklist.at(next);
1348 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1349 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1350 escape_worklist.push(ptn);
1351 }
1352 }
1353 // Set escape states to referenced nodes (edges list).
1354 while (escape_worklist.length() > 0) {
1355 PointsToNode* ptn = escape_worklist.pop();
1356 PointsToNode::EscapeState es = ptn->escape_state();
1357 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1358 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1359 es >= PointsToNode::ArgEscape) {
1360 // GlobalEscape or ArgEscape state of field means it has unknown value.
1361 if (add_edge(ptn, phantom_obj)) {
1362 // New edge was added
1363 add_field_uses_to_worklist(ptn->as_Field());
1364 }
1365 }
1366 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1367 PointsToNode* e = i.get();
1368 if (e->is_Arraycopy()) {
1369 assert(ptn->arraycopy_dst(), "sanity");
1370 // Propagate only fields escape state through arraycopy edge.
1371 if (e->fields_escape_state() < field_es) {
1372 set_fields_escape_state(e, field_es);
1373 escape_worklist.push(e);
1374 }
1375 } else if (es >= field_es) {
1376 // fields_escape_state is also set to 'es' if it is less than 'es'.
1377 if (e->escape_state() < es) {
1378 set_escape_state(e, es);
1379 escape_worklist.push(e);
1380 }
1381 } else {
1382 // Propagate field escape state.
1383 bool es_changed = false;
1384 if (e->fields_escape_state() < field_es) {
1385 set_fields_escape_state(e, field_es);
1386 es_changed = true;
1387 }
1388 if ((e->escape_state() < field_es) &&
1389 e->is_Field() && ptn->is_JavaObject() &&
1390 e->as_Field()->is_oop()) {
1391 // Change escape state of referenced fields.
1392 set_escape_state(e, field_es);
1393 es_changed = true;
1394 } else if (e->escape_state() < es) {
1395 set_escape_state(e, es);
1396 es_changed = true;
1397 }
1398 if (es_changed) {
1399 escape_worklist.push(e);
1400 }
1401 }
1402 }
1403 }
1404 // Remove escaped objects from non_escaped list.
1405 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1406 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1407 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1408 non_escaped_worklist.delete_at(next);
1409 }
1410 if (ptn->escape_state() == PointsToNode::NoEscape) {
1411 // Find fields in non-escaped allocations which have unknown value.
1412 find_init_values(ptn, phantom_obj, NULL);
1413 }
1414 }
1415 return (non_escaped_worklist.length() > 0);
1416 }
1417
1418 // Add all references to JavaObject node by walking over all uses.
1419 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1420 int new_edges = 0;
1421 if (populate_worklist) {
1422 // Populate _worklist by uses of jobj's uses.
1423 for (UseIterator i(jobj); i.has_next(); i.next()) {
1424 PointsToNode* use = i.get();
1425 if (use->is_Arraycopy())
1426 continue;
1427 add_uses_to_worklist(use);
1428 if (use->is_Field() && use->as_Field()->is_oop()) {
1429 // Put on worklist all field's uses (loads) and
1430 // related field nodes (same base and offset).
1431 add_field_uses_to_worklist(use->as_Field());
1432 }
1433 }
1434 }
1435 for (int l = 0; l < _worklist.length(); l++) {
1436 PointsToNode* use = _worklist.at(l);
1437 if (PointsToNode::is_base_use(use)) {
1438 // Add reference from jobj to field and from field to jobj (field's base).
1439 use = PointsToNode::get_use_node(use)->as_Field();
1440 if (add_base(use->as_Field(), jobj)) {
1441 new_edges++;
1442 }
1443 continue;
1444 }
1445 assert(!use->is_JavaObject(), "sanity");
1446 if (use->is_Arraycopy()) {
1447 if (jobj == null_obj) // NULL object does not have field edges
1448 continue;
1449 // Added edge from Arraycopy node to arraycopy's source java object
1450 if (add_edge(use, jobj)) {
1451 jobj->set_arraycopy_src();
1452 new_edges++;
1453 }
1454 // and stop here.
1455 continue;
1456 }
1457 if (!add_edge(use, jobj))
1458 continue; // No new edge added, there was such edge already.
1459 new_edges++;
1460 if (use->is_LocalVar()) {
1461 add_uses_to_worklist(use);
1462 if (use->arraycopy_dst()) {
1463 for (EdgeIterator i(use); i.has_next(); i.next()) {
1464 PointsToNode* e = i.get();
1465 if (e->is_Arraycopy()) {
1466 if (jobj == null_obj) // NULL object does not have field edges
1467 continue;
1468 // Add edge from arraycopy's destination java object to Arraycopy node.
1469 if (add_edge(jobj, e)) {
1470 new_edges++;
1471 jobj->set_arraycopy_dst();
1472 }
1473 }
1474 }
1475 }
1476 } else {
1477 // Added new edge to stored in field values.
1478 // Put on worklist all field's uses (loads) and
1479 // related field nodes (same base and offset).
1480 add_field_uses_to_worklist(use->as_Field());
1481 }
1482 }
1483 _worklist.clear();
1484 _in_worklist.Reset();
1485 return new_edges;
1486 }
1487
1488 // Put on worklist all related field nodes.
1489 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1490 assert(field->is_oop(), "sanity");
1491 int offset = field->offset();
1492 add_uses_to_worklist(field);
1493 // Loop over all bases of this field and push on worklist Field nodes
1494 // with the same offset and base (since they may reference the same field).
1495 for (BaseIterator i(field); i.has_next(); i.next()) {
1496 PointsToNode* base = i.get();
1497 add_fields_to_worklist(field, base);
1498 // Check if the base was source object of arraycopy and go over arraycopy's
1499 // destination objects since values stored to a field of source object are
1500 // accessable by uses (loads) of fields of destination objects.
1501 if (base->arraycopy_src()) {
1502 for (UseIterator j(base); j.has_next(); j.next()) {
1503 PointsToNode* arycp = j.get();
1504 if (arycp->is_Arraycopy()) {
1505 for (UseIterator k(arycp); k.has_next(); k.next()) {
1506 PointsToNode* abase = k.get();
1507 if (abase->arraycopy_dst() && abase != base) {
1508 // Look for the same arraycopy reference.
1509 add_fields_to_worklist(field, abase);
1510 }
1511 }
1512 }
1513 }
1514 }
1515 }
1516 }
1517
1518 // Put on worklist all related field nodes.
1519 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1520 int offset = field->offset();
1521 if (base->is_LocalVar()) {
1522 for (UseIterator j(base); j.has_next(); j.next()) {
1523 PointsToNode* f = j.get();
1524 if (PointsToNode::is_base_use(f)) { // Field
1525 f = PointsToNode::get_use_node(f);
1526 if (f == field || !f->as_Field()->is_oop())
1527 continue;
1528 int offs = f->as_Field()->offset();
1529 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1530 add_to_worklist(f);
1531 }
1532 }
1533 }
1534 } else {
1535 assert(base->is_JavaObject(), "sanity");
1536 if (// Skip phantom_object since it is only used to indicate that
1537 // this field's content globally escapes.
1538 (base != phantom_obj) &&
1539 // NULL object node does not have fields.
1540 (base != null_obj)) {
1541 for (EdgeIterator i(base); i.has_next(); i.next()) {
1542 PointsToNode* f = i.get();
1543 // Skip arraycopy edge since store to destination object field
1544 // does not update value in source object field.
1545 if (f->is_Arraycopy()) {
1546 assert(base->arraycopy_dst(), "sanity");
1547 continue;
1548 }
1549 if (f == field || !f->as_Field()->is_oop())
1550 continue;
1551 int offs = f->as_Field()->offset();
1552 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1553 add_to_worklist(f);
1554 }
1555 }
1556 }
1557 }
1558 }
1559
1560 // Find fields which have unknown value.
1561 int ConnectionGraph::find_field_value(FieldNode* field) {
1562 // Escaped fields should have init value already.
1563 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1564 int new_edges = 0;
1565 for (BaseIterator i(field); i.has_next(); i.next()) {
1566 PointsToNode* base = i.get();
1567 if (base->is_JavaObject()) {
1568 // Skip Allocate's fields which will be processed later.
1569 if (base->ideal_node()->is_Allocate())
1570 return 0;
1571 assert(base == null_obj, "only NULL ptr base expected here");
1572 }
1573 }
1574 if (add_edge(field, phantom_obj)) {
1575 // New edge was added
1576 new_edges++;
1577 add_field_uses_to_worklist(field);
1578 }
1579 return new_edges;
1580 }
1581
1582 // Find fields initializing values for allocations.
1583 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1584 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1585 int new_edges = 0;
1586 Node* alloc = pta->ideal_node();
1587 if (init_val == phantom_obj) {
1588 // Do nothing for Allocate nodes since its fields values are
1589 // "known" unless they are initialized by arraycopy/clone.
1590 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1591 return 0;
1592 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1593 #ifdef ASSERT
1594 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1595 const char* name = alloc->as_CallStaticJava()->_name;
1596 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1597 }
1598 #endif
1599 // Non-escaped allocation returned from Java or runtime call have
1600 // unknown values in fields.
1601 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1602 PointsToNode* field = i.get();
1603 if (field->is_Field() && field->as_Field()->is_oop()) {
1604 if (add_edge(field, phantom_obj)) {
1605 // New edge was added
1606 new_edges++;
1607 add_field_uses_to_worklist(field->as_Field());
1608 }
1609 }
1610 }
1611 return new_edges;
1612 }
1613 assert(init_val == null_obj, "sanity");
1614 // Do nothing for Call nodes since its fields values are unknown.
1615 if (!alloc->is_Allocate())
1616 return 0;
1617
1618 InitializeNode* ini = alloc->as_Allocate()->initialization();
1619 bool visited_bottom_offset = false;
1620 GrowableArray<int> offsets_worklist;
1621
1622 // Check if an oop field's initializing value is recorded and add
1623 // a corresponding NULL if field's value if it is not recorded.
1624 // Connection Graph does not record a default initialization by NULL
1625 // captured by Initialize node.
1626 //
1627 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1628 PointsToNode* field = i.get(); // Field (AddP)
1629 if (!field->is_Field() || !field->as_Field()->is_oop())
1630 continue; // Not oop field
1631 int offset = field->as_Field()->offset();
1632 if (offset == Type::OffsetBot) {
1633 if (!visited_bottom_offset) {
1634 // OffsetBot is used to reference array's element,
1635 // always add reference to NULL to all Field nodes since we don't
1636 // known which element is referenced.
1637 if (add_edge(field, null_obj)) {
1638 // New edge was added
1639 new_edges++;
1640 add_field_uses_to_worklist(field->as_Field());
1641 visited_bottom_offset = true;
1642 }
1643 }
1644 } else {
1645 // Check only oop fields.
1646 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1647 if (adr_type->isa_rawptr()) {
1648 #ifdef ASSERT
1649 // Raw pointers are used for initializing stores so skip it
1650 // since it should be recorded already
1651 Node* base = get_addp_base(field->ideal_node());
1652 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1653 (base->in(0) == alloc),"unexpected pointer type");
1654 #endif
1655 continue;
1656 }
1657 if (!offsets_worklist.contains(offset)) {
1658 offsets_worklist.append(offset);
1659 Node* value = NULL;
1660 if (ini != NULL) {
1661 // StoreP::memory_type() == T_ADDRESS
1662 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1663 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1664 // Make sure initializing store has the same type as this AddP.
1665 // This AddP may reference non existing field because it is on a
1666 // dead branch of bimorphic call which is not eliminated yet.
1667 if (store != NULL && store->is_Store() &&
1668 store->as_Store()->memory_type() == ft) {
1669 value = store->in(MemNode::ValueIn);
1670 #ifdef ASSERT
1671 if (VerifyConnectionGraph) {
1672 // Verify that AddP already points to all objects the value points to.
1673 PointsToNode* val = ptnode_adr(value->_idx);
1674 assert((val != NULL), "should be processed already");
1675 PointsToNode* missed_obj = NULL;
1676 if (val->is_JavaObject()) {
1677 if (!field->points_to(val->as_JavaObject())) {
1678 missed_obj = val;
1679 }
1680 } else {
1681 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1682 tty->print_cr("----------init store has invalid value -----");
1683 store->dump();
1684 val->dump();
1685 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1686 }
1687 for (EdgeIterator j(val); j.has_next(); j.next()) {
1688 PointsToNode* obj = j.get();
1689 if (obj->is_JavaObject()) {
1690 if (!field->points_to(obj->as_JavaObject())) {
1691 missed_obj = obj;
1692 break;
1693 }
1694 }
1695 }
1696 }
1697 if (missed_obj != NULL) {
1698 tty->print_cr("----------field---------------------------------");
1699 field->dump();
1700 tty->print_cr("----------missed referernce to object-----------");
1701 missed_obj->dump();
1702 tty->print_cr("----------object referernced by init store -----");
1703 store->dump();
1704 val->dump();
1705 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1706 }
1707 }
1708 #endif
1709 } else {
1710 // There could be initializing stores which follow allocation.
1711 // For example, a volatile field store is not collected
1712 // by Initialize node.
1713 //
1714 // Need to check for dependent loads to separate such stores from
1715 // stores which follow loads. For now, add initial value NULL so
1716 // that compare pointers optimization works correctly.
1717 }
1718 }
1719 if (value == NULL) {
1720 // A field's initializing value was not recorded. Add NULL.
1721 if (add_edge(field, null_obj)) {
1722 // New edge was added
1723 new_edges++;
1724 add_field_uses_to_worklist(field->as_Field());
1725 }
1726 }
1727 }
1728 }
1729 }
1730 return new_edges;
1731 }
1732
1733 // Adjust scalar_replaceable state after Connection Graph is built.
1734 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1735 // Search for non-escaping objects which are not scalar replaceable
1736 // and mark them to propagate the state to referenced objects.
1737
1738 // 1. An object is not scalar replaceable if the field into which it is
1739 // stored has unknown offset (stored into unknown element of an array).
1740 //
1741 for (UseIterator i(jobj); i.has_next(); i.next()) {
1742 PointsToNode* use = i.get();
1743 if (use->is_Arraycopy()) {
1744 continue;
1745 }
1746 if (use->is_Field()) {
1747 FieldNode* field = use->as_Field();
1748 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1749 if (field->offset() == Type::OffsetBot) {
1750 jobj->set_scalar_replaceable(false);
1751 return;
1752 }
1753 // 2. An object is not scalar replaceable if the field into which it is
1754 // stored has multiple bases one of which is null.
1755 if (field->base_count() > 1) {
1756 for (BaseIterator i(field); i.has_next(); i.next()) {
1757 PointsToNode* base = i.get();
1758 if (base == null_obj) {
1759 jobj->set_scalar_replaceable(false);
1760 return;
1761 }
1762 }
1763 }
1764 }
1765 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1766 // 3. An object is not scalar replaceable if it is merged with other objects.
1767 for (EdgeIterator j(use); j.has_next(); j.next()) {
1768 PointsToNode* ptn = j.get();
1769 if (ptn->is_JavaObject() && ptn != jobj) {
1770 // Mark all objects.
1771 jobj->set_scalar_replaceable(false);
1772 ptn->set_scalar_replaceable(false);
1773 }
1774 }
1775 if (!jobj->scalar_replaceable()) {
1776 return;
1777 }
1778 }
1779
1780 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1781 if (j.get()->is_Arraycopy()) {
1782 continue;
1783 }
1784
1785 // Non-escaping object node should point only to field nodes.
1786 FieldNode* field = j.get()->as_Field();
1787 int offset = field->as_Field()->offset();
1788
1789 // 4. An object is not scalar replaceable if it has a field with unknown
1790 // offset (array's element is accessed in loop).
1791 if (offset == Type::OffsetBot) {
1792 jobj->set_scalar_replaceable(false);
1793 return;
1794 }
1795 // 5. Currently an object is not scalar replaceable if a LoadStore node
1796 // access its field since the field value is unknown after it.
1797 //
1798 Node* n = field->ideal_node();
1799
1800 // Test for an unsafe access that was parsed as maybe off heap
1801 // (with a CheckCastPP to raw memory).
1802 assert(n->is_AddP(), "expect an address computation");
1803 if (n->in(AddPNode::Base)->is_top() &&
1804 n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
1805 assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
1806 assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
1807 jobj->set_scalar_replaceable(false);
1808 return;
1809 }
1810
1811 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1812 Node* u = n->fast_out(i);
1813 if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
1814 jobj->set_scalar_replaceable(false);
1815 return;
1816 }
1817 }
1818
1819 // 6. Or the address may point to more then one object. This may produce
1820 // the false positive result (set not scalar replaceable)
1821 // since the flow-insensitive escape analysis can't separate
1822 // the case when stores overwrite the field's value from the case
1823 // when stores happened on different control branches.
1824 //
1825 // Note: it will disable scalar replacement in some cases:
1826 //
1827 // Point p[] = new Point[1];
1828 // p[0] = new Point(); // Will be not scalar replaced
1829 //
1830 // but it will save us from incorrect optimizations in next cases:
1831 //
1832 // Point p[] = new Point[1];
1833 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1834 //
1835 if (field->base_count() > 1) {
1836 for (BaseIterator i(field); i.has_next(); i.next()) {
1837 PointsToNode* base = i.get();
1838 // Don't take into account LocalVar nodes which
1839 // may point to only one object which should be also
1840 // this field's base by now.
1841 if (base->is_JavaObject() && base != jobj) {
1842 // Mark all bases.
1843 jobj->set_scalar_replaceable(false);
1844 base->set_scalar_replaceable(false);
1845 }
1846 }
1847 }
1848 }
1849 }
1850
1851 #ifdef ASSERT
1852 void ConnectionGraph::verify_connection_graph(
1853 GrowableArray<PointsToNode*>& ptnodes_worklist,
1854 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1855 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1856 GrowableArray<Node*>& addp_worklist) {
1857 // Verify that graph is complete - no new edges could be added.
1858 int java_objects_length = java_objects_worklist.length();
1859 int non_escaped_length = non_escaped_worklist.length();
1860 int new_edges = 0;
1861 for (int next = 0; next < java_objects_length; ++next) {
1862 JavaObjectNode* ptn = java_objects_worklist.at(next);
1863 new_edges += add_java_object_edges(ptn, true);
1864 }
1865 assert(new_edges == 0, "graph was not complete");
1866 // Verify that escape state is final.
1867 int length = non_escaped_worklist.length();
1868 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1869 assert((non_escaped_length == non_escaped_worklist.length()) &&
1870 (non_escaped_length == length) &&
1871 (_worklist.length() == 0), "escape state was not final");
1872
1873 // Verify fields information.
1874 int addp_length = addp_worklist.length();
1875 for (int next = 0; next < addp_length; ++next ) {
1876 Node* n = addp_worklist.at(next);
1877 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1878 if (field->is_oop()) {
1879 // Verify that field has all bases
1880 Node* base = get_addp_base(n);
1881 PointsToNode* ptn = ptnode_adr(base->_idx);
1882 if (ptn->is_JavaObject()) {
1883 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1884 } else {
1885 assert(ptn->is_LocalVar(), "sanity");
1886 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1887 PointsToNode* e = i.get();
1888 if (e->is_JavaObject()) {
1889 assert(field->has_base(e->as_JavaObject()), "sanity");
1890 }
1891 }
1892 }
1893 // Verify that all fields have initializing values.
1894 if (field->edge_count() == 0) {
1895 tty->print_cr("----------field does not have references----------");
1896 field->dump();
1897 for (BaseIterator i(field); i.has_next(); i.next()) {
1898 PointsToNode* base = i.get();
1899 tty->print_cr("----------field has next base---------------------");
1900 base->dump();
1901 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1902 tty->print_cr("----------base has fields-------------------------");
1903 for (EdgeIterator j(base); j.has_next(); j.next()) {
1904 j.get()->dump();
1905 }
1906 tty->print_cr("----------base has references---------------------");
1907 for (UseIterator j(base); j.has_next(); j.next()) {
1908 j.get()->dump();
1909 }
1910 }
1911 }
1912 for (UseIterator i(field); i.has_next(); i.next()) {
1913 i.get()->dump();
1914 }
1915 assert(field->edge_count() > 0, "sanity");
1916 }
1917 }
1918 }
1919 }
1920 #endif
1921
1922 // Optimize ideal graph.
1923 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1924 GrowableArray<Node*>& storestore_worklist) {
1925 Compile* C = _compile;
1926 PhaseIterGVN* igvn = _igvn;
1927 if (EliminateLocks) {
1928 // Mark locks before changing ideal graph.
1929 int cnt = C->macro_count();
1930 for( int i=0; i < cnt; i++ ) {
1931 Node *n = C->macro_node(i);
1932 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1933 AbstractLockNode* alock = n->as_AbstractLock();
1934 if (!alock->is_non_esc_obj()) {
1935 if (not_global_escape(alock->obj_node())) {
1936 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1937 // The lock could be marked eliminated by lock coarsening
1938 // code during first IGVN before EA. Replace coarsened flag
1939 // to eliminate all associated locks/unlocks.
1940 #ifdef ASSERT
1941 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1942 #endif
1943 alock->set_non_esc_obj();
1944 }
1945 }
1946 }
1947 }
1948 }
1949
1950 if (OptimizePtrCompare) {
1951 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1952 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1953 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1954 // Optimize objects compare.
1955 while (ptr_cmp_worklist.length() != 0) {
1956 Node *n = ptr_cmp_worklist.pop();
1957 Node *res = optimize_ptr_compare(n);
1958 if (res != NULL) {
1959 #ifndef PRODUCT
1960 if (PrintOptimizePtrCompare) {
1961 tty->print_cr("++++ Replaced: %d %s(%d,%d) --> %s", n->_idx, (n->Opcode() == Op_CmpP ? "CmpP" : "CmpN"), n->in(1)->_idx, n->in(2)->_idx, (res == _pcmp_eq ? "EQ" : "NotEQ"));
1962 if (Verbose) {
1963 n->dump(1);
1964 }
1965 }
1966 #endif
1967 igvn->replace_node(n, res);
1968 }
1969 }
1970 // cleanup
1971 if (_pcmp_neq->outcnt() == 0)
1972 igvn->hash_delete(_pcmp_neq);
1973 if (_pcmp_eq->outcnt() == 0)
1974 igvn->hash_delete(_pcmp_eq);
1975 }
1976
1977 // For MemBarStoreStore nodes added in library_call.cpp, check
1978 // escape status of associated AllocateNode and optimize out
1979 // MemBarStoreStore node if the allocated object never escapes.
1980 while (storestore_worklist.length() != 0) {
1981 Node *n = storestore_worklist.pop();
1982 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1983 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1984 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1985 if (not_global_escape(alloc)) {
1986 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1987 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1988 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1989 igvn->register_new_node_with_optimizer(mb);
1990 igvn->replace_node(storestore, mb);
1991 }
1992 }
1993 }
1994
1995 // Optimize objects compare.
1996 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1997 assert(OptimizePtrCompare, "sanity");
1998 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1999 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
2000 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
2001 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
2002 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
2003 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
2004
2005 // Check simple cases first.
2006 if (jobj1 != NULL) {
2007 if (jobj1->escape_state() == PointsToNode::NoEscape) {
2008 if (jobj1 == jobj2) {
2009 // Comparing the same not escaping object.
2010 return _pcmp_eq;
2011 }
2012 Node* obj = jobj1->ideal_node();
2013 // Comparing not escaping allocation.
2014 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2015 !ptn2->points_to(jobj1)) {
2016 return _pcmp_neq; // This includes nullness check.
2017 }
2018 }
2019 }
2020 if (jobj2 != NULL) {
2021 if (jobj2->escape_state() == PointsToNode::NoEscape) {
2022 Node* obj = jobj2->ideal_node();
2023 // Comparing not escaping allocation.
2024 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2025 !ptn1->points_to(jobj2)) {
2026 return _pcmp_neq; // This includes nullness check.
2027 }
2028 }
2029 }
2030 if (jobj1 != NULL && jobj1 != phantom_obj &&
2031 jobj2 != NULL && jobj2 != phantom_obj &&
2032 jobj1->ideal_node()->is_Con() &&
2033 jobj2->ideal_node()->is_Con()) {
2034 // Klass or String constants compare. Need to be careful with
2035 // compressed pointers - compare types of ConN and ConP instead of nodes.
2036 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
2037 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
2038 if (t1->make_ptr() == t2->make_ptr()) {
2039 return _pcmp_eq;
2040 } else {
2041 return _pcmp_neq;
2042 }
2043 }
2044 if (ptn1->meet(ptn2)) {
2045 return NULL; // Sets are not disjoint
2046 }
2047
2048 // Sets are disjoint.
2049 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
2050 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
2051 bool set1_has_null_ptr = ptn1->points_to(null_obj);
2052 bool set2_has_null_ptr = ptn2->points_to(null_obj);
2053 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
2054 (set2_has_unknown_ptr && set1_has_null_ptr)) {
2055 // Check nullness of unknown object.
2056 return NULL;
2057 }
2058
2059 // Disjointness by itself is not sufficient since
2060 // alias analysis is not complete for escaped objects.
2061 // Disjoint sets are definitely unrelated only when
2062 // at least one set has only not escaping allocations.
2063 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2064 if (ptn1->non_escaping_allocation()) {
2065 return _pcmp_neq;
2066 }
2067 }
2068 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2069 if (ptn2->non_escaping_allocation()) {
2070 return _pcmp_neq;
2071 }
2072 }
2073 return NULL;
2074 }
2075
2076 // Connection Graph constuction functions.
2077
2078 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2079 PointsToNode* ptadr = _nodes.at(n->_idx);
2080 if (ptadr != NULL) {
2081 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2082 return;
2083 }
2084 Compile* C = _compile;
2085 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2086 _nodes.at_put(n->_idx, ptadr);
2087 }
2088
2089 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2090 PointsToNode* ptadr = _nodes.at(n->_idx);
2091 if (ptadr != NULL) {
2092 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2093 return;
2094 }
2095 Compile* C = _compile;
2096 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2097 _nodes.at_put(n->_idx, ptadr);
2098 }
2099
2100 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2101 PointsToNode* ptadr = _nodes.at(n->_idx);
2102 if (ptadr != NULL) {
2103 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2104 return;
2105 }
2106 bool unsafe = false;
2107 bool is_oop = is_oop_field(n, offset, &unsafe);
2108 if (unsafe) {
2109 es = PointsToNode::GlobalEscape;
2110 }
2111 Compile* C = _compile;
2112 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2113 _nodes.at_put(n->_idx, field);
2114 }
2115
2116 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2117 PointsToNode* src, PointsToNode* dst) {
2118 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2119 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2120 PointsToNode* ptadr = _nodes.at(n->_idx);
2121 if (ptadr != NULL) {
2122 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2123 return;
2124 }
2125 Compile* C = _compile;
2126 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2127 _nodes.at_put(n->_idx, ptadr);
2128 // Add edge from arraycopy node to source object.
2129 (void)add_edge(ptadr, src);
2130 src->set_arraycopy_src();
2131 // Add edge from destination object to arraycopy node.
2132 (void)add_edge(dst, ptadr);
2133 dst->set_arraycopy_dst();
2134 }
2135
2136 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2137 const Type* adr_type = n->as_AddP()->bottom_type();
2138 BasicType bt = T_INT;
2139 if (offset == Type::OffsetBot) {
2140 // Check only oop fields.
2141 if (!adr_type->isa_aryptr() ||
2142 (adr_type->isa_aryptr()->klass() == NULL) ||
2143 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2144 // OffsetBot is used to reference array's element. Ignore first AddP.
2145 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2146 bt = T_OBJECT;
2147 }
2148 }
2149 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2150 if (adr_type->isa_instptr()) {
2151 ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
2152 if (field != NULL) {
2153 bt = field->layout_type();
2154 } else {
2155 // Check for unsafe oop field access
2156 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2157 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2158 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2159 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2160 bt = T_OBJECT;
2161 (*unsafe) = true;
2162 }
2163 }
2164 } else if (adr_type->isa_aryptr()) {
2165 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2166 // Ignore array length load.
2167 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2168 // Ignore first AddP.
2169 } else {
2170 const Type* elemtype = adr_type->isa_aryptr()->elem();
2171 bt = elemtype->array_element_basic_type();
2172 }
2173 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2174 // Allocation initialization, ThreadLocal field access, unsafe access
2175 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2176 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2177 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2178 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2179 bt = T_OBJECT;
2180 }
2181 }
2182 }
2183 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2184 }
2185
2186 // Returns unique pointed java object or NULL.
2187 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2188 assert(!_collecting, "should not call when contructed graph");
2189 // If the node was created after the escape computation we can't answer.
2190 uint idx = n->_idx;
2191 if (idx >= nodes_size()) {
2192 return NULL;
2193 }
2194 PointsToNode* ptn = ptnode_adr(idx);
2195 if (ptn->is_JavaObject()) {
2196 return ptn->as_JavaObject();
2197 }
2198 assert(ptn->is_LocalVar(), "sanity");
2199 // Check all java objects it points to.
2200 JavaObjectNode* jobj = NULL;
2201 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2202 PointsToNode* e = i.get();
2203 if (e->is_JavaObject()) {
2204 if (jobj == NULL) {
2205 jobj = e->as_JavaObject();
2206 } else if (jobj != e) {
2207 return NULL;
2208 }
2209 }
2210 }
2211 return jobj;
2212 }
2213
2214 // Return true if this node points only to non-escaping allocations.
2215 bool PointsToNode::non_escaping_allocation() {
2216 if (is_JavaObject()) {
2217 Node* n = ideal_node();
2218 if (n->is_Allocate() || n->is_CallStaticJava()) {
2219 return (escape_state() == PointsToNode::NoEscape);
2220 } else {
2221 return false;
2222 }
2223 }
2224 assert(is_LocalVar(), "sanity");
2225 // Check all java objects it points to.
2226 for (EdgeIterator i(this); i.has_next(); i.next()) {
2227 PointsToNode* e = i.get();
2228 if (e->is_JavaObject()) {
2229 Node* n = e->ideal_node();
2230 if ((e->escape_state() != PointsToNode::NoEscape) ||
2231 !(n->is_Allocate() || n->is_CallStaticJava())) {
2232 return false;
2233 }
2234 }
2235 }
2236 return true;
2237 }
2238
2239 // Return true if we know the node does not escape globally.
2240 bool ConnectionGraph::not_global_escape(Node *n) {
2241 assert(!_collecting, "should not call during graph construction");
2242 // If the node was created after the escape computation we can't answer.
2243 uint idx = n->_idx;
2244 if (idx >= nodes_size()) {
2245 return false;
2246 }
2247 PointsToNode* ptn = ptnode_adr(idx);
2248 if (!ptn) {
2249 return false; // not in congraph (e.g. ConI)
2250 }
2251 PointsToNode::EscapeState es = ptn->escape_state();
2252 // If we have already computed a value, return it.
2253 if (es >= PointsToNode::GlobalEscape)
2254 return false;
2255 if (ptn->is_JavaObject()) {
2256 return true; // (es < PointsToNode::GlobalEscape);
2257 }
2258 assert(ptn->is_LocalVar(), "sanity");
2259 // Check all java objects it points to.
2260 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2261 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2262 return false;
2263 }
2264 return true;
2265 }
2266
2267
2268 // Helper functions
2269
2270 // Return true if this node points to specified node or nodes it points to.
2271 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2272 if (is_JavaObject()) {
2273 return (this == ptn);
2274 }
2275 assert(is_LocalVar() || is_Field(), "sanity");
2276 for (EdgeIterator i(this); i.has_next(); i.next()) {
2277 if (i.get() == ptn)
2278 return true;
2279 }
2280 return false;
2281 }
2282
2283 // Return true if one node points to an other.
2284 bool PointsToNode::meet(PointsToNode* ptn) {
2285 if (this == ptn) {
2286 return true;
2287 } else if (ptn->is_JavaObject()) {
2288 return this->points_to(ptn->as_JavaObject());
2289 } else if (this->is_JavaObject()) {
2290 return ptn->points_to(this->as_JavaObject());
2291 }
2292 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2293 int ptn_count = ptn->edge_count();
2294 for (EdgeIterator i(this); i.has_next(); i.next()) {
2295 PointsToNode* this_e = i.get();
2296 for (int j = 0; j < ptn_count; j++) {
2297 if (this_e == ptn->edge(j))
2298 return true;
2299 }
2300 }
2301 return false;
2302 }
2303
2304 #ifdef ASSERT
2305 // Return true if bases point to this java object.
2306 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2307 for (BaseIterator i(this); i.has_next(); i.next()) {
2308 if (i.get() == jobj)
2309 return true;
2310 }
2311 return false;
2312 }
2313 #endif
2314
2315 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2316 const Type *adr_type = phase->type(adr);
2317 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2318 adr->in(AddPNode::Address)->is_Proj() &&
2319 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2320 // We are computing a raw address for a store captured by an Initialize
2321 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2322 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2323 assert(offs != Type::OffsetBot ||
2324 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2325 "offset must be a constant or it is initialization of array");
2326 return offs;
2327 }
2328 const TypePtr *t_ptr = adr_type->isa_ptr();
2329 assert(t_ptr != NULL, "must be a pointer type");
2330 return t_ptr->offset();
2331 }
2332
2333 Node* ConnectionGraph::get_addp_base(Node *addp) {
2334 assert(addp->is_AddP(), "must be AddP");
2335 //
2336 // AddP cases for Base and Address inputs:
2337 // case #1. Direct object's field reference:
2338 // Allocate
2339 // |
2340 // Proj #5 ( oop result )
2341 // |
2342 // CheckCastPP (cast to instance type)
2343 // | |
2344 // AddP ( base == address )
2345 //
2346 // case #2. Indirect object's field reference:
2347 // Phi
2348 // |
2349 // CastPP (cast to instance type)
2350 // | |
2351 // AddP ( base == address )
2352 //
2353 // case #3. Raw object's field reference for Initialize node:
2354 // Allocate
2355 // |
2356 // Proj #5 ( oop result )
2357 // top |
2358 // \ |
2359 // AddP ( base == top )
2360 //
2361 // case #4. Array's element reference:
2362 // {CheckCastPP | CastPP}
2363 // | | |
2364 // | AddP ( array's element offset )
2365 // | |
2366 // AddP ( array's offset )
2367 //
2368 // case #5. Raw object's field reference for arraycopy stub call:
2369 // The inline_native_clone() case when the arraycopy stub is called
2370 // after the allocation before Initialize and CheckCastPP nodes.
2371 // Allocate
2372 // |
2373 // Proj #5 ( oop result )
2374 // | |
2375 // AddP ( base == address )
2376 //
2377 // case #6. Constant Pool, ThreadLocal, CastX2P or
2378 // Raw object's field reference:
2379 // {ConP, ThreadLocal, CastX2P, raw Load}
2380 // top |
2381 // \ |
2382 // AddP ( base == top )
2383 //
2384 // case #7. Klass's field reference.
2385 // LoadKlass
2386 // | |
2387 // AddP ( base == address )
2388 //
2389 // case #8. narrow Klass's field reference.
2390 // LoadNKlass
2391 // |
2392 // DecodeN
2393 // | |
2394 // AddP ( base == address )
2395 //
2396 // case #9. Mixed unsafe access
2397 // {instance}
2398 // |
2399 // CheckCastPP (raw)
2400 // top |
2401 // \ |
2402 // AddP ( base == top )
2403 //
2404 Node *base = addp->in(AddPNode::Base);
2405 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2406 base = addp->in(AddPNode::Address);
2407 while (base->is_AddP()) {
2408 // Case #6 (unsafe access) may have several chained AddP nodes.
2409 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2410 base = base->in(AddPNode::Address);
2411 }
2412 if (base->Opcode() == Op_CheckCastPP &&
2413 base->bottom_type()->isa_rawptr() &&
2414 _igvn->type(base->in(1))->isa_oopptr()) {
2415 base = base->in(1); // Case #9
2416 } else {
2417 Node* uncast_base = base->uncast();
2418 int opcode = uncast_base->Opcode();
2419 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2420 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2421 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2422 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2423 }
2424 }
2425 return base;
2426 }
2427
2428 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2429 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2430 Node* addp2 = addp->raw_out(0);
2431 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2432 addp2->in(AddPNode::Base) == n &&
2433 addp2->in(AddPNode::Address) == addp) {
2434 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2435 //
2436 // Find array's offset to push it on worklist first and
2437 // as result process an array's element offset first (pushed second)
2438 // to avoid CastPP for the array's offset.
2439 // Otherwise the inserted CastPP (LocalVar) will point to what
2440 // the AddP (Field) points to. Which would be wrong since
2441 // the algorithm expects the CastPP has the same point as
2442 // as AddP's base CheckCastPP (LocalVar).
2443 //
2444 // ArrayAllocation
2445 // |
2446 // CheckCastPP
2447 // |
2448 // memProj (from ArrayAllocation CheckCastPP)
2449 // | ||
2450 // | || Int (element index)
2451 // | || | ConI (log(element size))
2452 // | || | /
2453 // | || LShift
2454 // | || /
2455 // | AddP (array's element offset)
2456 // | |
2457 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2458 // | / /
2459 // AddP (array's offset)
2460 // |
2461 // Load/Store (memory operation on array's element)
2462 //
2463 return addp2;
2464 }
2465 return NULL;
2466 }
2467
2468 //
2469 // Adjust the type and inputs of an AddP which computes the
2470 // address of a field of an instance
2471 //
2472 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2473 PhaseGVN* igvn = _igvn;
2474 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2475 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2476 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2477 if (t == NULL) {
2478 // We are computing a raw address for a store captured by an Initialize
2479 // compute an appropriate address type (cases #3 and #5).
2480 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2481 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2482 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2483 assert(offs != Type::OffsetBot, "offset must be a constant");
2484 t = base_t->add_offset(offs)->is_oopptr();
2485 }
2486 int inst_id = base_t->instance_id();
2487 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2488 "old type must be non-instance or match new type");
2489
2490 // The type 't' could be subclass of 'base_t'.
2491 // As result t->offset() could be large then base_t's size and it will
2492 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2493 // constructor verifies correctness of the offset.
2494 //
2495 // It could happened on subclass's branch (from the type profiling
2496 // inlining) which was not eliminated during parsing since the exactness
2497 // of the allocation type was not propagated to the subclass type check.
2498 //
2499 // Or the type 't' could be not related to 'base_t' at all.
2500 // It could happened when CHA type is different from MDO type on a dead path
2501 // (for example, from instanceof check) which is not collapsed during parsing.
2502 //
2503 // Do nothing for such AddP node and don't process its users since
2504 // this code branch will go away.
2505 //
2506 if (!t->is_known_instance() &&
2507 !base_t->klass()->is_subtype_of(t->klass())) {
2508 return false; // bail out
2509 }
2510 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2511 // Do NOT remove the next line: ensure a new alias index is allocated
2512 // for the instance type. Note: C++ will not remove it since the call
2513 // has side effect.
2514 int alias_idx = _compile->get_alias_index(tinst);
2515 igvn->set_type(addp, tinst);
2516 // record the allocation in the node map
2517 set_map(addp, get_map(base->_idx));
2518 // Set addp's Base and Address to 'base'.
2519 Node *abase = addp->in(AddPNode::Base);
2520 Node *adr = addp->in(AddPNode::Address);
2521 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2522 adr->in(0)->_idx == (uint)inst_id) {
2523 // Skip AddP cases #3 and #5.
2524 } else {
2525 assert(!abase->is_top(), "sanity"); // AddP case #3
2526 if (abase != base) {
2527 igvn->hash_delete(addp);
2528 addp->set_req(AddPNode::Base, base);
2529 if (abase == adr) {
2530 addp->set_req(AddPNode::Address, base);
2531 } else {
2532 // AddP case #4 (adr is array's element offset AddP node)
2533 #ifdef ASSERT
2534 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2535 assert(adr->is_AddP() && atype != NULL &&
2536 atype->instance_id() == inst_id, "array's element offset should be processed first");
2537 #endif
2538 }
2539 igvn->hash_insert(addp);
2540 }
2541 }
2542 // Put on IGVN worklist since at least addp's type was changed above.
2543 record_for_optimizer(addp);
2544 return true;
2545 }
2546
2547 //
2548 // Create a new version of orig_phi if necessary. Returns either the newly
2549 // created phi or an existing phi. Sets create_new to indicate whether a new
2550 // phi was created. Cache the last newly created phi in the node map.
2551 //
2552 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2553 Compile *C = _compile;
2554 PhaseGVN* igvn = _igvn;
2555 new_created = false;
2556 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2557 // nothing to do if orig_phi is bottom memory or matches alias_idx
2558 if (phi_alias_idx == alias_idx) {
2559 return orig_phi;
2560 }
2561 // Have we recently created a Phi for this alias index?
2562 PhiNode *result = get_map_phi(orig_phi->_idx);
2563 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2564 return result;
2565 }
2566 // Previous check may fail when the same wide memory Phi was split into Phis
2567 // for different memory slices. Search all Phis for this region.
2568 if (result != NULL) {
2569 Node* region = orig_phi->in(0);
2570 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2571 Node* phi = region->fast_out(i);
2572 if (phi->is_Phi() &&
2573 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2574 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2575 return phi->as_Phi();
2576 }
2577 }
2578 }
2579 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2580 if (C->do_escape_analysis() == true && !C->failing()) {
2581 // Retry compilation without escape analysis.
2582 // If this is the first failure, the sentinel string will "stick"
2583 // to the Compile object, and the C2Compiler will see it and retry.
2584 C->record_failure(C2Compiler::retry_no_escape_analysis());
2585 }
2586 return NULL;
2587 }
2588 orig_phi_worklist.append_if_missing(orig_phi);
2589 const TypePtr *atype = C->get_adr_type(alias_idx);
2590 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2591 C->copy_node_notes_to(result, orig_phi);
2592 igvn->set_type(result, result->bottom_type());
2593 record_for_optimizer(result);
2594 set_map(orig_phi, result);
2595 new_created = true;
2596 return result;
2597 }
2598
2599 //
2600 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2601 // specified alias index.
2602 //
2603 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2604 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2605 Compile *C = _compile;
2606 PhaseGVN* igvn = _igvn;
2607 bool new_phi_created;
2608 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2609 if (!new_phi_created) {
2610 return result;
2611 }
2612 GrowableArray<PhiNode *> phi_list;
2613 GrowableArray<uint> cur_input;
2614 PhiNode *phi = orig_phi;
2615 uint idx = 1;
2616 bool finished = false;
2617 while(!finished) {
2618 while (idx < phi->req()) {
2619 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2620 if (mem != NULL && mem->is_Phi()) {
2621 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2622 if (new_phi_created) {
2623 // found an phi for which we created a new split, push current one on worklist and begin
2624 // processing new one
2625 phi_list.push(phi);
2626 cur_input.push(idx);
2627 phi = mem->as_Phi();
2628 result = newphi;
2629 idx = 1;
2630 continue;
2631 } else {
2632 mem = newphi;
2633 }
2634 }
2635 if (C->failing()) {
2636 return NULL;
2637 }
2638 result->set_req(idx++, mem);
2639 }
2640 #ifdef ASSERT
2641 // verify that the new Phi has an input for each input of the original
2642 assert( phi->req() == result->req(), "must have same number of inputs.");
2643 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2644 #endif
2645 // Check if all new phi's inputs have specified alias index.
2646 // Otherwise use old phi.
2647 for (uint i = 1; i < phi->req(); i++) {
2648 Node* in = result->in(i);
2649 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2650 }
2651 // we have finished processing a Phi, see if there are any more to do
2652 finished = (phi_list.length() == 0 );
2653 if (!finished) {
2654 phi = phi_list.pop();
2655 idx = cur_input.pop();
2656 PhiNode *prev_result = get_map_phi(phi->_idx);
2657 prev_result->set_req(idx++, result);
2658 result = prev_result;
2659 }
2660 }
2661 return result;
2662 }
2663
2664 //
2665 // The next methods are derived from methods in MemNode.
2666 //
2667 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2668 Node *mem = mmem;
2669 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2670 // means an array I have not precisely typed yet. Do not do any
2671 // alias stuff with it any time soon.
2672 if (toop->base() != Type::AnyPtr &&
2673 !(toop->klass() != NULL &&
2674 toop->klass()->is_java_lang_Object() &&
2675 toop->offset() == Type::OffsetBot)) {
2676 mem = mmem->memory_at(alias_idx);
2677 // Update input if it is progress over what we have now
2678 }
2679 return mem;
2680 }
2681
2682 //
2683 // Move memory users to their memory slices.
2684 //
2685 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2686 Compile* C = _compile;
2687 PhaseGVN* igvn = _igvn;
2688 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2689 assert(tp != NULL, "ptr type");
2690 int alias_idx = C->get_alias_index(tp);
2691 int general_idx = C->get_general_index(alias_idx);
2692
2693 // Move users first
2694 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2695 Node* use = n->fast_out(i);
2696 if (use->is_MergeMem()) {
2697 MergeMemNode* mmem = use->as_MergeMem();
2698 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2699 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2700 continue; // Nothing to do
2701 }
2702 // Replace previous general reference to mem node.
2703 uint orig_uniq = C->unique();
2704 Node* m = find_inst_mem(n, general_idx, orig_phis);
2705 assert(orig_uniq == C->unique(), "no new nodes");
2706 mmem->set_memory_at(general_idx, m);
2707 --imax;
2708 --i;
2709 } else if (use->is_MemBar()) {
2710 assert(!use->is_Initialize(), "initializing stores should not be moved");
2711 if (use->req() > MemBarNode::Precedent &&
2712 use->in(MemBarNode::Precedent) == n) {
2713 // Don't move related membars.
2714 record_for_optimizer(use);
2715 continue;
2716 }
2717 tp = use->as_MemBar()->adr_type()->isa_ptr();
2718 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2719 alias_idx == general_idx) {
2720 continue; // Nothing to do
2721 }
2722 // Move to general memory slice.
2723 uint orig_uniq = C->unique();
2724 Node* m = find_inst_mem(n, general_idx, orig_phis);
2725 assert(orig_uniq == C->unique(), "no new nodes");
2726 igvn->hash_delete(use);
2727 imax -= use->replace_edge(n, m);
2728 igvn->hash_insert(use);
2729 record_for_optimizer(use);
2730 --i;
2731 #ifdef ASSERT
2732 } else if (use->is_Mem()) {
2733 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2734 // Don't move related cardmark.
2735 continue;
2736 }
2737 // Memory nodes should have new memory input.
2738 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2739 assert(tp != NULL, "ptr type");
2740 int idx = C->get_alias_index(tp);
2741 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2742 "Following memory nodes should have new memory input or be on the same memory slice");
2743 } else if (use->is_Phi()) {
2744 // Phi nodes should be split and moved already.
2745 tp = use->as_Phi()->adr_type()->isa_ptr();
2746 assert(tp != NULL, "ptr type");
2747 int idx = C->get_alias_index(tp);
2748 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2749 } else {
2750 use->dump();
2751 assert(false, "should not be here");
2752 #endif
2753 }
2754 }
2755 }
2756
2757 //
2758 // Search memory chain of "mem" to find a MemNode whose address
2759 // is the specified alias index.
2760 //
2761 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2762 if (orig_mem == NULL)
2763 return orig_mem;
2764 Compile* C = _compile;
2765 PhaseGVN* igvn = _igvn;
2766 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2767 bool is_instance = (toop != NULL) && toop->is_known_instance();
2768 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2769 Node *prev = NULL;
2770 Node *result = orig_mem;
2771 while (prev != result) {
2772 prev = result;
2773 if (result == start_mem)
2774 break; // hit one of our sentinels
2775 if (result->is_Mem()) {
2776 const Type *at = igvn->type(result->in(MemNode::Address));
2777 if (at == Type::TOP)
2778 break; // Dead
2779 assert (at->isa_ptr() != NULL, "pointer type required.");
2780 int idx = C->get_alias_index(at->is_ptr());
2781 if (idx == alias_idx)
2782 break; // Found
2783 if (!is_instance && (at->isa_oopptr() == NULL ||
2784 !at->is_oopptr()->is_known_instance())) {
2785 break; // Do not skip store to general memory slice.
2786 }
2787 result = result->in(MemNode::Memory);
2788 }
2789 if (!is_instance)
2790 continue; // don't search further for non-instance types
2791 // skip over a call which does not affect this memory slice
2792 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2793 Node *proj_in = result->in(0);
2794 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2795 break; // hit one of our sentinels
2796 } else if (proj_in->is_Call()) {
2797 // ArrayCopy node processed here as well
2798 CallNode *call = proj_in->as_Call();
2799 if (!call->may_modify(toop, igvn)) {
2800 result = call->in(TypeFunc::Memory);
2801 }
2802 } else if (proj_in->is_Initialize()) {
2803 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2804 // Stop if this is the initialization for the object instance which
2805 // which contains this memory slice, otherwise skip over it.
2806 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2807 result = proj_in->in(TypeFunc::Memory);
2808 }
2809 } else if (proj_in->is_MemBar()) {
2810 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2811 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2812 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2813 // clone
2814 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2815 if (ac->may_modify(toop, igvn)) {
2816 break;
2817 }
2818 }
2819 result = proj_in->in(TypeFunc::Memory);
2820 }
2821 } else if (result->is_MergeMem()) {
2822 MergeMemNode *mmem = result->as_MergeMem();
2823 result = step_through_mergemem(mmem, alias_idx, toop);
2824 if (result == mmem->base_memory()) {
2825 // Didn't find instance memory, search through general slice recursively.
2826 result = mmem->memory_at(C->get_general_index(alias_idx));
2827 result = find_inst_mem(result, alias_idx, orig_phis);
2828 if (C->failing()) {
2829 return NULL;
2830 }
2831 mmem->set_memory_at(alias_idx, result);
2832 }
2833 } else if (result->is_Phi() &&
2834 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2835 Node *un = result->as_Phi()->unique_input(igvn);
2836 if (un != NULL) {
2837 orig_phis.append_if_missing(result->as_Phi());
2838 result = un;
2839 } else {
2840 break;
2841 }
2842 } else if (result->is_ClearArray()) {
2843 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2844 // Can not bypass initialization of the instance
2845 // we are looking for.
2846 break;
2847 }
2848 // Otherwise skip it (the call updated 'result' value).
2849 } else if (result->Opcode() == Op_SCMemProj) {
2850 Node* mem = result->in(0);
2851 Node* adr = NULL;
2852 if (mem->is_LoadStore()) {
2853 adr = mem->in(MemNode::Address);
2854 } else {
2855 assert(mem->Opcode() == Op_EncodeISOArray ||
2856 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2857 adr = mem->in(3); // Memory edge corresponds to destination array
2858 }
2859 const Type *at = igvn->type(adr);
2860 if (at != Type::TOP) {
2861 assert(at->isa_ptr() != NULL, "pointer type required.");
2862 int idx = C->get_alias_index(at->is_ptr());
2863 if (idx == alias_idx) {
2864 // Assert in debug mode
2865 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2866 break; // In product mode return SCMemProj node
2867 }
2868 }
2869 result = mem->in(MemNode::Memory);
2870 } else if (result->Opcode() == Op_StrInflatedCopy) {
2871 Node* adr = result->in(3); // Memory edge corresponds to destination array
2872 const Type *at = igvn->type(adr);
2873 if (at != Type::TOP) {
2874 assert(at->isa_ptr() != NULL, "pointer type required.");
2875 int idx = C->get_alias_index(at->is_ptr());
2876 if (idx == alias_idx) {
2877 // Assert in debug mode
2878 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2879 break; // In product mode return SCMemProj node
2880 }
2881 }
2882 result = result->in(MemNode::Memory);
2883 }
2884 }
2885 if (result->is_Phi()) {
2886 PhiNode *mphi = result->as_Phi();
2887 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2888 const TypePtr *t = mphi->adr_type();
2889 if (!is_instance) {
2890 // Push all non-instance Phis on the orig_phis worklist to update inputs
2891 // during Phase 4 if needed.
2892 orig_phis.append_if_missing(mphi);
2893 } else if (C->get_alias_index(t) != alias_idx) {
2894 // Create a new Phi with the specified alias index type.
2895 result = split_memory_phi(mphi, alias_idx, orig_phis);
2896 }
2897 }
2898 // the result is either MemNode, PhiNode, InitializeNode.
2899 return result;
2900 }
2901
2902 //
2903 // Convert the types of unescaped object to instance types where possible,
2904 // propagate the new type information through the graph, and update memory
2905 // edges and MergeMem inputs to reflect the new type.
2906 //
2907 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2908 // The processing is done in 4 phases:
2909 //
2910 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2911 // types for the CheckCastPP for allocations where possible.
2912 // Propagate the new types through users as follows:
2913 // casts and Phi: push users on alloc_worklist
2914 // AddP: cast Base and Address inputs to the instance type
2915 // push any AddP users on alloc_worklist and push any memnode
2916 // users onto memnode_worklist.
2917 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2918 // search the Memory chain for a store with the appropriate type
2919 // address type. If a Phi is found, create a new version with
2920 // the appropriate memory slices from each of the Phi inputs.
2921 // For stores, process the users as follows:
2922 // MemNode: push on memnode_worklist
2923 // MergeMem: push on mergemem_worklist
2924 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2925 // moving the first node encountered of each instance type to the
2926 // the input corresponding to its alias index.
2927 // appropriate memory slice.
2928 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2929 //
2930 // In the following example, the CheckCastPP nodes are the cast of allocation
2931 // results and the allocation of node 29 is unescaped and eligible to be an
2932 // instance type.
2933 //
2934 // We start with:
2935 //
2936 // 7 Parm #memory
2937 // 10 ConI "12"
2938 // 19 CheckCastPP "Foo"
2939 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2940 // 29 CheckCastPP "Foo"
2941 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2942 //
2943 // 40 StoreP 25 7 20 ... alias_index=4
2944 // 50 StoreP 35 40 30 ... alias_index=4
2945 // 60 StoreP 45 50 20 ... alias_index=4
2946 // 70 LoadP _ 60 30 ... alias_index=4
2947 // 80 Phi 75 50 60 Memory alias_index=4
2948 // 90 LoadP _ 80 30 ... alias_index=4
2949 // 100 LoadP _ 80 20 ... alias_index=4
2950 //
2951 //
2952 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2953 // and creating a new alias index for node 30. This gives:
2954 //
2955 // 7 Parm #memory
2956 // 10 ConI "12"
2957 // 19 CheckCastPP "Foo"
2958 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2959 // 29 CheckCastPP "Foo" iid=24
2960 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2961 //
2962 // 40 StoreP 25 7 20 ... alias_index=4
2963 // 50 StoreP 35 40 30 ... alias_index=6
2964 // 60 StoreP 45 50 20 ... alias_index=4
2965 // 70 LoadP _ 60 30 ... alias_index=6
2966 // 80 Phi 75 50 60 Memory alias_index=4
2967 // 90 LoadP _ 80 30 ... alias_index=6
2968 // 100 LoadP _ 80 20 ... alias_index=4
2969 //
2970 // In phase 2, new memory inputs are computed for the loads and stores,
2971 // And a new version of the phi is created. In phase 4, the inputs to
2972 // node 80 are updated and then the memory nodes are updated with the
2973 // values computed in phase 2. This results in:
2974 //
2975 // 7 Parm #memory
2976 // 10 ConI "12"
2977 // 19 CheckCastPP "Foo"
2978 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2979 // 29 CheckCastPP "Foo" iid=24
2980 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2981 //
2982 // 40 StoreP 25 7 20 ... alias_index=4
2983 // 50 StoreP 35 7 30 ... alias_index=6
2984 // 60 StoreP 45 40 20 ... alias_index=4
2985 // 70 LoadP _ 50 30 ... alias_index=6
2986 // 80 Phi 75 40 60 Memory alias_index=4
2987 // 120 Phi 75 50 50 Memory alias_index=6
2988 // 90 LoadP _ 120 30 ... alias_index=6
2989 // 100 LoadP _ 80 20 ... alias_index=4
2990 //
2991 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2992 GrowableArray<Node *> memnode_worklist;
2993 GrowableArray<PhiNode *> orig_phis;
2994 PhaseIterGVN *igvn = _igvn;
2995 uint new_index_start = (uint) _compile->num_alias_types();
2996 Arena* arena = Thread::current()->resource_area();
2997 VectorSet visited(arena);
2998 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2999 uint unique_old = _compile->unique();
3000
3001 // Phase 1: Process possible allocations from alloc_worklist.
3002 // Create instance types for the CheckCastPP for allocations where possible.
3003 //
3004 // (Note: don't forget to change the order of the second AddP node on
3005 // the alloc_worklist if the order of the worklist processing is changed,
3006 // see the comment in find_second_addp().)
3007 //
3008 while (alloc_worklist.length() != 0) {
3009 Node *n = alloc_worklist.pop();
3010 uint ni = n->_idx;
3011 if (n->is_Call()) {
3012 CallNode *alloc = n->as_Call();
3013 // copy escape information to call node
3014 PointsToNode* ptn = ptnode_adr(alloc->_idx);
3015 PointsToNode::EscapeState es = ptn->escape_state();
3016 // We have an allocation or call which returns a Java object,
3017 // see if it is unescaped.
3018 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
3019 continue;
3020 // Find CheckCastPP for the allocate or for the return value of a call
3021 n = alloc->result_cast();
3022 if (n == NULL) { // No uses except Initialize node
3023 if (alloc->is_Allocate()) {
3024 // Set the scalar_replaceable flag for allocation
3025 // so it could be eliminated if it has no uses.
3026 alloc->as_Allocate()->_is_scalar_replaceable = true;
3027 }
3028 if (alloc->is_CallStaticJava()) {
3029 // Set the scalar_replaceable flag for boxing method
3030 // so it could be eliminated if it has no uses.
3031 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3032 }
3033 continue;
3034 }
3035 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
3036 assert(!alloc->is_Allocate(), "allocation should have unique type");
3037 continue;
3038 }
3039
3040 // The inline code for Object.clone() casts the allocation result to
3041 // java.lang.Object and then to the actual type of the allocated
3042 // object. Detect this case and use the second cast.
3043 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
3044 // the allocation result is cast to java.lang.Object and then
3045 // to the actual Array type.
3046 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
3047 && (alloc->is_AllocateArray() ||
3048 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
3049 Node *cast2 = NULL;
3050 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3051 Node *use = n->fast_out(i);
3052 if (use->is_CheckCastPP()) {
3053 cast2 = use;
3054 break;
3055 }
3056 }
3057 if (cast2 != NULL) {
3058 n = cast2;
3059 } else {
3060 // Non-scalar replaceable if the allocation type is unknown statically
3061 // (reflection allocation), the object can't be restored during
3062 // deoptimization without precise type.
3063 continue;
3064 }
3065 }
3066
3067 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
3068 if (t == NULL)
3069 continue; // not a TypeOopPtr
3070 if (!t->klass_is_exact())
3071 continue; // not an unique type
3072
3073 if (alloc->is_Allocate()) {
3074 // Set the scalar_replaceable flag for allocation
3075 // so it could be eliminated.
3076 alloc->as_Allocate()->_is_scalar_replaceable = true;
3077 }
3078 if (alloc->is_CallStaticJava()) {
3079 // Set the scalar_replaceable flag for boxing method
3080 // so it could be eliminated.
3081 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3082 }
3083 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3084 // in order for an object to be scalar-replaceable, it must be:
3085 // - a direct allocation (not a call returning an object)
3086 // - non-escaping
3087 // - eligible to be a unique type
3088 // - not determined to be ineligible by escape analysis
3089 set_map(alloc, n);
3090 set_map(n, alloc);
3091 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3092 igvn->hash_delete(n);
3093 igvn->set_type(n, tinst);
3094 n->raise_bottom_type(tinst);
3095 igvn->hash_insert(n);
3096 record_for_optimizer(n);
3097 // Allocate an alias index for the header fields. Accesses to
3098 // the header emitted during macro expansion wouldn't have
3099 // correct memory state otherwise.
3100 _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
3101 _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
3102 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3103
3104 // First, put on the worklist all Field edges from Connection Graph
3105 // which is more accurate than putting immediate users from Ideal Graph.
3106 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3107 PointsToNode* tgt = e.get();
3108 if (tgt->is_Arraycopy()) {
3109 continue;
3110 }
3111 Node* use = tgt->ideal_node();
3112 assert(tgt->is_Field() && use->is_AddP(),
3113 "only AddP nodes are Field edges in CG");
3114 if (use->outcnt() > 0) { // Don't process dead nodes
3115 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3116 if (addp2 != NULL) {
3117 assert(alloc->is_AllocateArray(),"array allocation was expected");
3118 alloc_worklist.append_if_missing(addp2);
3119 }
3120 alloc_worklist.append_if_missing(use);
3121 }
3122 }
3123
3124 // An allocation may have an Initialize which has raw stores. Scan
3125 // the users of the raw allocation result and push AddP users
3126 // on alloc_worklist.
3127 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3128 assert (raw_result != NULL, "must have an allocation result");
3129 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3130 Node *use = raw_result->fast_out(i);
3131 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3132 Node* addp2 = find_second_addp(use, raw_result);
3133 if (addp2 != NULL) {
3134 assert(alloc->is_AllocateArray(),"array allocation was expected");
3135 alloc_worklist.append_if_missing(addp2);
3136 }
3137 alloc_worklist.append_if_missing(use);
3138 } else if (use->is_MemBar()) {
3139 memnode_worklist.append_if_missing(use);
3140 }
3141 }
3142 }
3143 } else if (n->is_AddP()) {
3144 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3145 if (jobj == NULL || jobj == phantom_obj) {
3146 #ifdef ASSERT
3147 ptnode_adr(get_addp_base(n)->_idx)->dump();
3148 ptnode_adr(n->_idx)->dump();
3149 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3150 #endif
3151 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3152 return;
3153 }
3154 Node *base = get_map(jobj->idx()); // CheckCastPP node
3155 if (!split_AddP(n, base)) continue; // wrong type from dead path
3156 } else if (n->is_Phi() ||
3157 n->is_CheckCastPP() ||
3158 n->is_EncodeP() ||
3159 n->is_DecodeN() ||
3160 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3161 if (visited.test_set(n->_idx)) {
3162 assert(n->is_Phi(), "loops only through Phi's");
3163 continue; // already processed
3164 }
3165 JavaObjectNode* jobj = unique_java_object(n);
3166 if (jobj == NULL || jobj == phantom_obj) {
3167 #ifdef ASSERT
3168 ptnode_adr(n->_idx)->dump();
3169 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3170 #endif
3171 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3172 return;
3173 } else {
3174 Node *val = get_map(jobj->idx()); // CheckCastPP node
3175 TypeNode *tn = n->as_Type();
3176 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3177 assert(tinst != NULL && tinst->is_known_instance() &&
3178 tinst->instance_id() == jobj->idx() , "instance type expected.");
3179
3180 const Type *tn_type = igvn->type(tn);
3181 const TypeOopPtr *tn_t;
3182 if (tn_type->isa_narrowoop()) {
3183 tn_t = tn_type->make_ptr()->isa_oopptr();
3184 } else {
3185 tn_t = tn_type->isa_oopptr();
3186 }
3187 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3188 if (tn_type->isa_narrowoop()) {
3189 tn_type = tinst->make_narrowoop();
3190 } else {
3191 tn_type = tinst;
3192 }
3193 igvn->hash_delete(tn);
3194 igvn->set_type(tn, tn_type);
3195 tn->set_type(tn_type);
3196 igvn->hash_insert(tn);
3197 record_for_optimizer(n);
3198 } else {
3199 assert(tn_type == TypePtr::NULL_PTR ||
3200 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3201 "unexpected type");
3202 continue; // Skip dead path with different type
3203 }
3204 }
3205 } else {
3206 debug_only(n->dump();)
3207 assert(false, "EA: unexpected node");
3208 continue;
3209 }
3210 // push allocation's users on appropriate worklist
3211 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3212 Node *use = n->fast_out(i);
3213 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3214 // Load/store to instance's field
3215 memnode_worklist.append_if_missing(use);
3216 } else if (use->is_MemBar()) {
3217 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3218 memnode_worklist.append_if_missing(use);
3219 }
3220 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3221 Node* addp2 = find_second_addp(use, n);
3222 if (addp2 != NULL) {
3223 alloc_worklist.append_if_missing(addp2);
3224 }
3225 alloc_worklist.append_if_missing(use);
3226 } else if (use->is_Phi() ||
3227 use->is_CheckCastPP() ||
3228 use->is_EncodeNarrowPtr() ||
3229 use->is_DecodeNarrowPtr() ||
3230 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3231 alloc_worklist.append_if_missing(use);
3232 #ifdef ASSERT
3233 } else if (use->is_Mem()) {
3234 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3235 } else if (use->is_MergeMem()) {
3236 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3237 } else if (use->is_SafePoint()) {
3238 // Look for MergeMem nodes for calls which reference unique allocation
3239 // (through CheckCastPP nodes) even for debug info.
3240 Node* m = use->in(TypeFunc::Memory);
3241 if (m->is_MergeMem()) {
3242 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3243 }
3244 } else if (use->Opcode() == Op_EncodeISOArray) {
3245 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3246 // EncodeISOArray overwrites destination array
3247 memnode_worklist.append_if_missing(use);
3248 }
3249 } else {
3250 uint op = use->Opcode();
3251 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3252 (use->in(MemNode::Memory) == n)) {
3253 // They overwrite memory edge corresponding to destination array,
3254 memnode_worklist.append_if_missing(use);
3255 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3256 op == Op_CastP2X || op == Op_StoreCM ||
3257 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3258 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3259 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3260 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
3261 n->dump();
3262 use->dump();
3263 assert(false, "EA: missing allocation reference path");
3264 }
3265 #endif
3266 }
3267 }
3268
3269 }
3270
3271 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3272 // type, record it in the ArrayCopy node so we know what memory this
3273 // node uses/modified.
3274 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3275 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3276 Node* dest = ac->in(ArrayCopyNode::Dest);
3277 if (dest->is_AddP()) {
3278 dest = get_addp_base(dest);
3279 }
3280 JavaObjectNode* jobj = unique_java_object(dest);
3281 if (jobj != NULL) {
3282 Node *base = get_map(jobj->idx());
3283 if (base != NULL) {
3284 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3285 ac->_dest_type = base_t;
3286 }
3287 }
3288 Node* src = ac->in(ArrayCopyNode::Src);
3289 if (src->is_AddP()) {
3290 src = get_addp_base(src);
3291 }
3292 jobj = unique_java_object(src);
3293 if (jobj != NULL) {
3294 Node* base = get_map(jobj->idx());
3295 if (base != NULL) {
3296 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3297 ac->_src_type = base_t;
3298 }
3299 }
3300 }
3301
3302 // New alias types were created in split_AddP().
3303 uint new_index_end = (uint) _compile->num_alias_types();
3304 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3305
3306 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3307 // compute new values for Memory inputs (the Memory inputs are not
3308 // actually updated until phase 4.)
3309 if (memnode_worklist.length() == 0)
3310 return; // nothing to do
3311 while (memnode_worklist.length() != 0) {
3312 Node *n = memnode_worklist.pop();
3313 if (visited.test_set(n->_idx))
3314 continue;
3315 if (n->is_Phi() || n->is_ClearArray()) {
3316 // we don't need to do anything, but the users must be pushed
3317 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3318 // we don't need to do anything, but the users must be pushed
3319 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3320 if (n == NULL)
3321 continue;
3322 } else if (n->Opcode() == Op_StrCompressedCopy ||
3323 n->Opcode() == Op_EncodeISOArray) {
3324 // get the memory projection
3325 n = n->find_out_with(Op_SCMemProj);
3326 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3327 } else {
3328 assert(n->is_Mem(), "memory node required.");
3329 Node *addr = n->in(MemNode::Address);
3330 const Type *addr_t = igvn->type(addr);
3331 if (addr_t == Type::TOP)
3332 continue;
3333 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3334 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3335 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3336 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3337 if (_compile->failing()) {
3338 return;
3339 }
3340 if (mem != n->in(MemNode::Memory)) {
3341 // We delay the memory edge update since we need old one in
3342 // MergeMem code below when instances memory slices are separated.
3343 set_map(n, mem);
3344 }
3345 if (n->is_Load()) {
3346 continue; // don't push users
3347 } else if (n->is_LoadStore()) {
3348 // get the memory projection
3349 n = n->find_out_with(Op_SCMemProj);
3350 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3351 }
3352 }
3353 // push user on appropriate worklist
3354 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3355 Node *use = n->fast_out(i);
3356 if (use->is_Phi() || use->is_ClearArray()) {
3357 memnode_worklist.append_if_missing(use);
3358 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3359 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3360 continue;
3361 memnode_worklist.append_if_missing(use);
3362 } else if (use->is_MemBar()) {
3363 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3364 memnode_worklist.append_if_missing(use);
3365 }
3366 #ifdef ASSERT
3367 } else if(use->is_Mem()) {
3368 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3369 } else if (use->is_MergeMem()) {
3370 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3371 } else if (use->Opcode() == Op_EncodeISOArray) {
3372 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3373 // EncodeISOArray overwrites destination array
3374 memnode_worklist.append_if_missing(use);
3375 }
3376 } else {
3377 uint op = use->Opcode();
3378 if ((use->in(MemNode::Memory) == n) &&
3379 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3380 // They overwrite memory edge corresponding to destination array,
3381 memnode_worklist.append_if_missing(use);
3382 } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
3383 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3384 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3385 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3386 n->dump();
3387 use->dump();
3388 assert(false, "EA: missing memory path");
3389 }
3390 #endif
3391 }
3392 }
3393 }
3394
3395 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3396 // Walk each memory slice moving the first node encountered of each
3397 // instance type to the the input corresponding to its alias index.
3398 uint length = _mergemem_worklist.length();
3399 for( uint next = 0; next < length; ++next ) {
3400 MergeMemNode* nmm = _mergemem_worklist.at(next);
3401 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3402 // Note: we don't want to use MergeMemStream here because we only want to
3403 // scan inputs which exist at the start, not ones we add during processing.
3404 // Note 2: MergeMem may already contains instance memory slices added
3405 // during find_inst_mem() call when memory nodes were processed above.
3406 igvn->hash_delete(nmm);
3407 uint nslices = MIN2(nmm->req(), new_index_start);
3408 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3409 Node* mem = nmm->in(i);
3410 Node* cur = NULL;
3411 if (mem == NULL || mem->is_top())
3412 continue;
3413 // First, update mergemem by moving memory nodes to corresponding slices
3414 // if their type became more precise since this mergemem was created.
3415 while (mem->is_Mem()) {
3416 const Type *at = igvn->type(mem->in(MemNode::Address));
3417 if (at != Type::TOP) {
3418 assert (at->isa_ptr() != NULL, "pointer type required.");
3419 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3420 if (idx == i) {
3421 if (cur == NULL)
3422 cur = mem;
3423 } else {
3424 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3425 nmm->set_memory_at(idx, mem);
3426 }
3427 }
3428 }
3429 mem = mem->in(MemNode::Memory);
3430 }
3431 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3432 // Find any instance of the current type if we haven't encountered
3433 // already a memory slice of the instance along the memory chain.
3434 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3435 if((uint)_compile->get_general_index(ni) == i) {
3436 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3437 if (nmm->is_empty_memory(m)) {
3438 Node* result = find_inst_mem(mem, ni, orig_phis);
3439 if (_compile->failing()) {
3440 return;
3441 }
3442 nmm->set_memory_at(ni, result);
3443 }
3444 }
3445 }
3446 }
3447 // Find the rest of instances values
3448 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3449 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3450 Node* result = step_through_mergemem(nmm, ni, tinst);
3451 if (result == nmm->base_memory()) {
3452 // Didn't find instance memory, search through general slice recursively.
3453 result = nmm->memory_at(_compile->get_general_index(ni));
3454 result = find_inst_mem(result, ni, orig_phis);
3455 if (_compile->failing()) {
3456 return;
3457 }
3458 nmm->set_memory_at(ni, result);
3459 }
3460 }
3461 igvn->hash_insert(nmm);
3462 record_for_optimizer(nmm);
3463 }
3464
3465 // Phase 4: Update the inputs of non-instance memory Phis and
3466 // the Memory input of memnodes
3467 // First update the inputs of any non-instance Phi's from
3468 // which we split out an instance Phi. Note we don't have
3469 // to recursively process Phi's encounted on the input memory
3470 // chains as is done in split_memory_phi() since they will
3471 // also be processed here.
3472 for (int j = 0; j < orig_phis.length(); j++) {
3473 PhiNode *phi = orig_phis.at(j);
3474 int alias_idx = _compile->get_alias_index(phi->adr_type());
3475 igvn->hash_delete(phi);
3476 for (uint i = 1; i < phi->req(); i++) {
3477 Node *mem = phi->in(i);
3478 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3479 if (_compile->failing()) {
3480 return;
3481 }
3482 if (mem != new_mem) {
3483 phi->set_req(i, new_mem);
3484 }
3485 }
3486 igvn->hash_insert(phi);
3487 record_for_optimizer(phi);
3488 }
3489
3490 // Update the memory inputs of MemNodes with the value we computed
3491 // in Phase 2 and move stores memory users to corresponding memory slices.
3492 // Disable memory split verification code until the fix for 6984348.
3493 // Currently it produces false negative results since it does not cover all cases.
3494 #if 0 // ifdef ASSERT
3495 visited.Reset();
3496 Node_Stack old_mems(arena, _compile->unique() >> 2);
3497 #endif
3498 for (uint i = 0; i < ideal_nodes.size(); i++) {
3499 Node* n = ideal_nodes.at(i);
3500 Node* nmem = get_map(n->_idx);
3501 assert(nmem != NULL, "sanity");
3502 if (n->is_Mem()) {
3503 #if 0 // ifdef ASSERT
3504 Node* old_mem = n->in(MemNode::Memory);
3505 if (!visited.test_set(old_mem->_idx)) {
3506 old_mems.push(old_mem, old_mem->outcnt());
3507 }
3508 #endif
3509 assert(n->in(MemNode::Memory) != nmem, "sanity");
3510 if (!n->is_Load()) {
3511 // Move memory users of a store first.
3512 move_inst_mem(n, orig_phis);
3513 }
3514 // Now update memory input
3515 igvn->hash_delete(n);
3516 n->set_req(MemNode::Memory, nmem);
3517 igvn->hash_insert(n);
3518 record_for_optimizer(n);
3519 } else {
3520 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3521 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3522 }
3523 }
3524 #if 0 // ifdef ASSERT
3525 // Verify that memory was split correctly
3526 while (old_mems.is_nonempty()) {
3527 Node* old_mem = old_mems.node();
3528 uint old_cnt = old_mems.index();
3529 old_mems.pop();
3530 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3531 }
3532 #endif
3533 }
3534
3535 #ifndef PRODUCT
3536 static const char *node_type_names[] = {
3537 "UnknownType",
3538 "JavaObject",
3539 "LocalVar",
3540 "Field",
3541 "Arraycopy"
3542 };
3543
3544 static const char *esc_names[] = {
3545 "UnknownEscape",
3546 "NoEscape",
3547 "ArgEscape",
3548 "GlobalEscape"
3549 };
3550
3551 void PointsToNode::dump(bool print_state) const {
3552 NodeType nt = node_type();
3553 tty->print("%s ", node_type_names[(int) nt]);
3554 if (print_state) {
3555 EscapeState es = escape_state();
3556 EscapeState fields_es = fields_escape_state();
3557 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3558 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3559 tty->print("NSR ");
3560 }
3561 if (is_Field()) {
3562 FieldNode* f = (FieldNode*)this;
3563 if (f->is_oop())
3564 tty->print("oop ");
3565 if (f->offset() > 0)
3566 tty->print("+%d ", f->offset());
3567 tty->print("(");
3568 for (BaseIterator i(f); i.has_next(); i.next()) {
3569 PointsToNode* b = i.get();
3570 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3571 }
3572 tty->print(" )");
3573 }
3574 tty->print("[");
3575 for (EdgeIterator i(this); i.has_next(); i.next()) {
3576 PointsToNode* e = i.get();
3577 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3578 }
3579 tty->print(" [");
3580 for (UseIterator i(this); i.has_next(); i.next()) {
3581 PointsToNode* u = i.get();
3582 bool is_base = false;
3583 if (PointsToNode::is_base_use(u)) {
3584 is_base = true;
3585 u = PointsToNode::get_use_node(u)->as_Field();
3586 }
3587 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3588 }
3589 tty->print(" ]] ");
3590 if (_node == NULL)
3591 tty->print_cr("<null>");
3592 else
3593 _node->dump();
3594 }
3595
3596 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3597 bool first = true;
3598 int ptnodes_length = ptnodes_worklist.length();
3599 for (int i = 0; i < ptnodes_length; i++) {
3600 PointsToNode *ptn = ptnodes_worklist.at(i);
3601 if (ptn == NULL || !ptn->is_JavaObject())
3602 continue;
3603 PointsToNode::EscapeState es = ptn->escape_state();
3604 if ((es != PointsToNode::NoEscape) && !Verbose) {
3605 continue;
3606 }
3607 Node* n = ptn->ideal_node();
3608 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3609 n->as_CallStaticJava()->is_boxing_method())) {
3610 if (first) {
3611 tty->cr();
3612 tty->print("======== Connection graph for ");
3613 _compile->method()->print_short_name();
3614 tty->cr();
3615 first = false;
3616 }
3617 ptn->dump();
3618 // Print all locals and fields which reference this allocation
3619 for (UseIterator j(ptn); j.has_next(); j.next()) {
3620 PointsToNode* use = j.get();
3621 if (use->is_LocalVar()) {
3622 use->dump(Verbose);
3623 } else if (Verbose) {
3624 use->dump();
3625 }
3626 }
3627 tty->cr();
3628 }
3629 }
3630 }
3631 #endif
3632
3633 void ConnectionGraph::record_for_optimizer(Node *n) {
3634 _igvn->_worklist.push(n);
3635 _igvn->add_users_to_worklist(n);
3636 }