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