1 /*
2 * Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/c2compiler.hpp"
32 #include "opto/arraycopynode.hpp"
33 #include "opto/callnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/compile.hpp"
36 #include "opto/escape.hpp"
37 #include "opto/phaseX.hpp"
38 #include "opto/movenode.hpp"
39 #include "opto/rootnode.hpp"
40
41 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
42 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
43 _in_worklist(C->comp_arena()),
44 _next_pidx(0),
45 _collecting(true),
46 _verify(false),
47 _compile(C),
48 _igvn(igvn),
49 _node_map(C->comp_arena()) {
50 // Add unknown java object.
51 add_java_object(C->top(), PointsToNode::GlobalEscape);
52 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
53 // Add ConP(#NULL) and ConN(#NULL) nodes.
54 Node* oop_null = igvn->zerocon(T_OBJECT);
55 assert(oop_null->_idx < nodes_size(), "should be created already");
56 add_java_object(oop_null, PointsToNode::NoEscape);
57 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
58 if (UseCompressedOops) {
59 Node* noop_null = igvn->zerocon(T_NARROWOOP);
60 assert(noop_null->_idx < nodes_size(), "should be created already");
61 map_ideal_node(noop_null, null_obj);
62 }
63 _pcmp_neq = NULL; // Should be initialized
64 _pcmp_eq = NULL;
65 }
66
67 bool ConnectionGraph::has_candidates(Compile *C) {
68 // EA brings benefits only when the code has allocations and/or locks which
69 // are represented by ideal Macro nodes.
70 int cnt = C->macro_count();
71 for (int i = 0; i < cnt; i++) {
72 Node *n = C->macro_node(i);
73 if (n->is_Allocate())
74 return true;
75 if (n->is_Lock()) {
76 Node* obj = n->as_Lock()->obj_node()->uncast();
77 if (!(obj->is_Parm() || obj->is_Con()))
78 return true;
79 }
80 if (n->is_CallStaticJava() &&
81 n->as_CallStaticJava()->is_boxing_method()) {
82 return true;
83 }
84 }
85 return false;
86 }
87
88 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
89 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
90 ResourceMark rm;
91
92 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
93 // to create space for them in ConnectionGraph::_nodes[].
94 Node* oop_null = igvn->zerocon(T_OBJECT);
95 Node* noop_null = igvn->zerocon(T_NARROWOOP);
96 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
97 // Perform escape analysis
98 if (congraph->compute_escape()) {
99 // There are non escaping objects.
100 C->set_congraph(congraph);
101 }
102 // Cleanup.
103 if (oop_null->outcnt() == 0)
104 igvn->hash_delete(oop_null);
105 if (noop_null->outcnt() == 0)
106 igvn->hash_delete(noop_null);
107 }
108
109 bool ConnectionGraph::compute_escape() {
110 Compile* C = _compile;
111 PhaseGVN* igvn = _igvn;
112
113 // Worklists used by EA.
114 Unique_Node_List delayed_worklist;
115 GrowableArray<Node*> alloc_worklist;
116 GrowableArray<Node*> ptr_cmp_worklist;
117 GrowableArray<Node*> storestore_worklist;
118 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
119 GrowableArray<PointsToNode*> ptnodes_worklist;
120 GrowableArray<JavaObjectNode*> java_objects_worklist;
121 GrowableArray<JavaObjectNode*> non_escaped_worklist;
122 GrowableArray<FieldNode*> oop_fields_worklist;
123 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
124
125 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
126
127 // 1. Populate Connection Graph (CG) with PointsTo nodes.
128 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
129 // Initialize worklist
130 if (C->root() != NULL) {
131 ideal_nodes.push(C->root());
132 }
133 // Processed ideal nodes are unique on ideal_nodes list
134 // but several ideal nodes are mapped to the phantom_obj.
135 // To avoid duplicated entries on the following worklists
136 // add the phantom_obj only once to them.
137 ptnodes_worklist.append(phantom_obj);
138 java_objects_worklist.append(phantom_obj);
139 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
140 Node* n = ideal_nodes.at(next);
141 // Create PointsTo nodes and add them to Connection Graph. Called
142 // only once per ideal node since ideal_nodes is Unique_Node list.
143 add_node_to_connection_graph(n, &delayed_worklist);
144 PointsToNode* ptn = ptnode_adr(n->_idx);
145 if (ptn != NULL && ptn != phantom_obj) {
146 ptnodes_worklist.append(ptn);
147 if (ptn->is_JavaObject()) {
148 java_objects_worklist.append(ptn->as_JavaObject());
149 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
150 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
151 // Only allocations and java static calls results are interesting.
152 non_escaped_worklist.append(ptn->as_JavaObject());
153 }
154 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
155 oop_fields_worklist.append(ptn->as_Field());
156 }
157 }
158 if (n->is_MergeMem()) {
159 // Collect all MergeMem nodes to add memory slices for
160 // scalar replaceable objects in split_unique_types().
161 _mergemem_worklist.append(n->as_MergeMem());
162 } else if (OptimizePtrCompare && n->is_Cmp() &&
163 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
164 // Collect compare pointers nodes.
165 ptr_cmp_worklist.append(n);
166 } else if (n->is_MemBarStoreStore()) {
167 // Collect all MemBarStoreStore nodes so that depending on the
168 // escape status of the associated Allocate node some of them
169 // may be eliminated.
170 storestore_worklist.append(n);
171 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
172 (n->req() > MemBarNode::Precedent)) {
173 record_for_optimizer(n);
174 #ifdef ASSERT
175 } else if (n->is_AddP()) {
176 // Collect address nodes for graph verification.
177 addp_worklist.append(n);
178 #endif
179 } else if (n->is_ArrayCopy()) {
180 // Keep a list of ArrayCopy nodes so if one of its input is non
181 // escaping, we can record a unique type
182 arraycopy_worklist.append(n->as_ArrayCopy());
183 }
184 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
185 Node* m = n->fast_out(i); // Get user
186 ideal_nodes.push(m);
187 }
188 }
189 if (non_escaped_worklist.length() == 0) {
190 _collecting = false;
191 return false; // Nothing to do.
192 }
193 // Add final simple edges to graph.
194 while(delayed_worklist.size() > 0) {
195 Node* n = delayed_worklist.pop();
196 add_final_edges(n);
197 }
198 int ptnodes_length = ptnodes_worklist.length();
199
200 #ifdef ASSERT
201 if (VerifyConnectionGraph) {
202 // Verify that no new simple edges could be created and all
203 // local vars has edges.
204 _verify = true;
205 for (int next = 0; next < ptnodes_length; ++next) {
206 PointsToNode* ptn = ptnodes_worklist.at(next);
207 add_final_edges(ptn->ideal_node());
208 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
209 ptn->dump();
210 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
211 }
212 }
213 _verify = false;
214 }
215 #endif
216 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
217 // processing, calls to CI to resolve symbols (types, fields, methods)
218 // referenced in bytecode. During symbol resolution VM may throw
219 // an exception which CI cleans and converts to compilation failure.
220 if (C->failing()) return false;
221
222 // 2. Finish Graph construction by propagating references to all
223 // java objects through graph.
224 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
225 java_objects_worklist, oop_fields_worklist)) {
226 // All objects escaped or hit time or iterations limits.
227 _collecting = false;
228 return false;
229 }
230
231 // 3. Adjust scalar_replaceable state of nonescaping objects and push
232 // scalar replaceable allocations on alloc_worklist for processing
233 // in split_unique_types().
234 int non_escaped_length = non_escaped_worklist.length();
235 for (int next = 0; next < non_escaped_length; next++) {
236 JavaObjectNode* ptn = non_escaped_worklist.at(next);
237 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
238 Node* n = ptn->ideal_node();
239 if (n->is_Allocate()) {
240 n->as_Allocate()->_is_non_escaping = noescape;
241 }
242 if (n->is_CallStaticJava()) {
243 n->as_CallStaticJava()->_is_non_escaping = noescape;
244 }
245 if (noescape && ptn->scalar_replaceable()) {
246 adjust_scalar_replaceable_state(ptn);
247 if (ptn->scalar_replaceable()) {
248 alloc_worklist.append(ptn->ideal_node());
249 }
250 }
251 }
252
253 #ifdef ASSERT
254 if (VerifyConnectionGraph) {
255 // Verify that graph is complete - no new edges could be added or needed.
256 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
257 java_objects_worklist, addp_worklist);
258 }
259 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
260 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
261 null_obj->edge_count() == 0 &&
262 !null_obj->arraycopy_src() &&
263 !null_obj->arraycopy_dst(), "sanity");
264 #endif
265
266 _collecting = false;
267
268 } // TracePhase t3("connectionGraph")
269
270 // 4. Optimize ideal graph based on EA information.
271 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
272 if (has_non_escaping_obj) {
273 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
274 }
275
276 #ifndef PRODUCT
277 if (PrintEscapeAnalysis) {
278 dump(ptnodes_worklist); // Dump ConnectionGraph
279 }
280 #endif
281
282 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
283 #ifdef ASSERT
284 if (VerifyConnectionGraph) {
285 int alloc_length = alloc_worklist.length();
286 for (int next = 0; next < alloc_length; ++next) {
287 Node* n = alloc_worklist.at(next);
288 PointsToNode* ptn = ptnode_adr(n->_idx);
289 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
290 }
291 }
292 #endif
293
294 // 5. Separate memory graph for scalar replaceable allcations.
295 if (has_scalar_replaceable_candidates &&
296 C->AliasLevel() >= 3 && EliminateAllocations) {
297 // Now use the escape information to create unique types for
298 // scalar replaceable objects.
299 split_unique_types(alloc_worklist, arraycopy_worklist);
300 if (C->failing()) return false;
301 C->print_method(PHASE_AFTER_EA, 2);
302
303 #ifdef ASSERT
304 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
305 tty->print("=== No allocations eliminated for ");
306 C->method()->print_short_name();
307 if(!EliminateAllocations) {
308 tty->print(" since EliminateAllocations is off ===");
309 } else if(!has_scalar_replaceable_candidates) {
310 tty->print(" since there are no scalar replaceable candidates ===");
311 } else if(C->AliasLevel() < 3) {
312 tty->print(" since AliasLevel < 3 ===");
313 }
314 tty->cr();
315 #endif
316 }
317 return has_non_escaping_obj;
318 }
319
320 // Utility function for nodes that load an object
321 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
322 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
323 // ThreadLocal has RawPtr type.
324 const Type* t = _igvn->type(n);
325 if (t->make_ptr() != NULL) {
326 Node* adr = n->in(MemNode::Address);
327 #ifdef ASSERT
328 if (!adr->is_AddP()) {
329 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
330 } else {
331 assert((ptnode_adr(adr->_idx) == NULL ||
332 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
333 }
334 #endif
335 add_local_var_and_edge(n, PointsToNode::NoEscape,
336 adr, delayed_worklist);
337 }
338 }
339
340 // Populate Connection Graph with PointsTo nodes and create simple
341 // connection graph edges.
342 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
343 assert(!_verify, "this method should not be called for verification");
344 PhaseGVN* igvn = _igvn;
345 uint n_idx = n->_idx;
346 PointsToNode* n_ptn = ptnode_adr(n_idx);
347 if (n_ptn != NULL)
348 return; // No need to redefine PointsTo node during first iteration.
349
350 if (n->is_Call()) {
351 // Arguments to allocation and locking don't escape.
352 if (n->is_AbstractLock()) {
353 // Put Lock and Unlock nodes on IGVN worklist to process them during
354 // first IGVN optimization when escape information is still available.
355 record_for_optimizer(n);
356 } else if (n->is_Allocate()) {
357 add_call_node(n->as_Call());
358 record_for_optimizer(n);
359 } else {
360 if (n->is_CallStaticJava()) {
361 const char* name = n->as_CallStaticJava()->_name;
362 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
363 return; // Skip uncommon traps
364 }
365 // Don't mark as processed since call's arguments have to be processed.
366 delayed_worklist->push(n);
367 // Check if a call returns an object.
368 if ((n->as_Call()->returns_pointer() &&
369 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) ||
370 (n->is_CallStaticJava() &&
371 n->as_CallStaticJava()->is_boxing_method())) {
372 add_call_node(n->as_Call());
373 } else if (n->as_Call()->tf()->returns_value_type_as_fields()) {
374 bool returns_oop = false;
375 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax && !returns_oop; i++) {
376 ProjNode* pn = n->fast_out(i)->as_Proj();
377 if (pn->_con >= TypeFunc::Parms && pn->bottom_type()->isa_oopptr()) {
378 returns_oop = true;
379 }
380 }
381 if (returns_oop) {
382 add_call_node(n->as_Call());
383 }
384 }
385 }
386 return;
387 }
388 // Put this check here to process call arguments since some call nodes
389 // point to phantom_obj.
390 if (n_ptn == phantom_obj || n_ptn == null_obj)
391 return; // Skip predefined nodes.
392
393 int opcode = n->Opcode();
394 switch (opcode) {
395 case Op_AddP: {
396 Node* base = get_addp_base(n);
397 PointsToNode* ptn_base = ptnode_adr(base->_idx);
398 // Field nodes are created for all field types. They are used in
399 // adjust_scalar_replaceable_state() and split_unique_types().
400 // Note, non-oop fields will have only base edges in Connection
401 // Graph because such fields are not used for oop loads and stores.
402 int offset = address_offset(n, igvn);
403 add_field(n, PointsToNode::NoEscape, offset);
404 if (ptn_base == NULL) {
405 delayed_worklist->push(n); // Process it later.
406 } else {
407 n_ptn = ptnode_adr(n_idx);
408 add_base(n_ptn->as_Field(), ptn_base);
409 }
410 break;
411 }
412 case Op_CastX2P: {
413 map_ideal_node(n, phantom_obj);
414 break;
415 }
416 case Op_CastPP:
417 case Op_CheckCastPP:
418 case Op_EncodeP:
419 case Op_DecodeN:
420 case Op_EncodePKlass:
421 case Op_DecodeNKlass: {
422 add_local_var_and_edge(n, PointsToNode::NoEscape,
423 n->in(1), delayed_worklist);
424 break;
425 }
426 case Op_CMoveP: {
427 add_local_var(n, PointsToNode::NoEscape);
428 // Do not add edges during first iteration because some could be
429 // not defined yet.
430 delayed_worklist->push(n);
431 break;
432 }
433 case Op_ConP:
434 case Op_ConN:
435 case Op_ConNKlass: {
436 // assume all oop constants globally escape except for null
437 PointsToNode::EscapeState es;
438 const Type* t = igvn->type(n);
439 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
440 es = PointsToNode::NoEscape;
441 } else {
442 es = PointsToNode::GlobalEscape;
443 }
444 add_java_object(n, es);
445 break;
446 }
447 case Op_CreateEx: {
448 // assume that all exception objects globally escape
449 map_ideal_node(n, phantom_obj);
450 break;
451 }
452 case Op_LoadKlass:
453 case Op_LoadNKlass: {
454 // Unknown class is loaded
455 map_ideal_node(n, phantom_obj);
456 break;
457 }
458 case Op_LoadP:
459 case Op_LoadN:
460 case Op_LoadPLocked: {
461 add_objload_to_connection_graph(n, delayed_worklist);
462 break;
463 }
464 case Op_Parm: {
465 map_ideal_node(n, phantom_obj);
466 break;
467 }
468 case Op_PartialSubtypeCheck: {
469 // Produces Null or notNull and is used in only in CmpP so
470 // phantom_obj could be used.
471 map_ideal_node(n, phantom_obj); // Result is unknown
472 break;
473 }
474 case Op_Phi: {
475 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
476 // ThreadLocal has RawPtr type.
477 const Type* t = n->as_Phi()->type();
478 if (t->make_ptr() != NULL) {
479 add_local_var(n, PointsToNode::NoEscape);
480 // Do not add edges during first iteration because some could be
481 // not defined yet.
482 delayed_worklist->push(n);
483 }
484 break;
485 }
486 case Op_Proj: {
487 // we are only interested in the oop result projection from a call
488 if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() &&
489 (n->in(0)->as_Call()->returns_pointer() || n->bottom_type()->isa_oopptr())) {
490 assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
491 n->in(0)->as_Call()->tf()->returns_value_type_as_fields(), "what kind of oop return is it?");
492 add_local_var_and_edge(n, PointsToNode::NoEscape,
493 n->in(0), delayed_worklist);
494 }
495 break;
496 }
497 case Op_Rethrow: // Exception object escapes
498 case Op_Return: {
499 if (n->req() > TypeFunc::Parms &&
500 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
501 // Treat Return value as LocalVar with GlobalEscape escape state.
502 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
503 n->in(TypeFunc::Parms), delayed_worklist);
504 }
505 break;
506 }
507 case Op_CompareAndExchangeP:
508 case Op_CompareAndExchangeN:
509 case Op_GetAndSetP:
510 case Op_GetAndSetN: {
511 add_objload_to_connection_graph(n, delayed_worklist);
512 // fallthrough
513 }
514 case Op_StoreP:
515 case Op_StoreN:
516 case Op_StoreNKlass:
517 case Op_StorePConditional:
518 case Op_WeakCompareAndSwapP:
519 case Op_WeakCompareAndSwapN:
520 case Op_CompareAndSwapP:
521 case Op_CompareAndSwapN: {
522 Node* adr = n->in(MemNode::Address);
523 const Type *adr_type = igvn->type(adr);
524 adr_type = adr_type->make_ptr();
525 if (adr_type == NULL) {
526 break; // skip dead nodes
527 }
528 if (adr_type->isa_oopptr() ||
529 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
530 (adr_type == TypeRawPtr::NOTNULL &&
531 adr->in(AddPNode::Address)->is_Proj() &&
532 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
533 delayed_worklist->push(n); // Process it later.
534 #ifdef ASSERT
535 assert(adr->is_AddP(), "expecting an AddP");
536 if (adr_type == TypeRawPtr::NOTNULL) {
537 // Verify a raw address for a store captured by Initialize node.
538 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
539 assert(offs != Type::OffsetBot, "offset must be a constant");
540 }
541 #endif
542 } else {
543 // Ignore copy the displaced header to the BoxNode (OSR compilation).
544 if (adr->is_BoxLock())
545 break;
546 // Stored value escapes in unsafe access.
547 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
548 // Pointer stores in G1 barriers looks like unsafe access.
549 // Ignore such stores to be able scalar replace non-escaping
550 // allocations.
551 if (UseG1GC && adr->is_AddP()) {
552 Node* base = get_addp_base(adr);
553 if (base->Opcode() == Op_LoadP &&
554 base->in(MemNode::Address)->is_AddP()) {
555 adr = base->in(MemNode::Address);
556 Node* tls = get_addp_base(adr);
557 if (tls->Opcode() == Op_ThreadLocal) {
558 int offs = (int)igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
559 if (offs == in_bytes(JavaThread::satb_mark_queue_offset() +
560 SATBMarkQueue::byte_offset_of_buf())) {
561 break; // G1 pre barrier previous oop value store.
562 }
563 if (offs == in_bytes(JavaThread::dirty_card_queue_offset() +
564 DirtyCardQueue::byte_offset_of_buf())) {
565 break; // G1 post barrier card address store.
566 }
567 }
568 }
569 }
570 delayed_worklist->push(n); // Process unsafe access later.
571 break;
572 }
573 #ifdef ASSERT
574 n->dump(1);
575 assert(false, "not unsafe or G1 barrier raw StoreP");
576 #endif
577 }
578 break;
579 }
580 case Op_AryEq:
581 case Op_HasNegatives:
582 case Op_StrComp:
583 case Op_StrEquals:
584 case Op_StrIndexOf:
585 case Op_StrIndexOfChar:
586 case Op_StrInflatedCopy:
587 case Op_StrCompressedCopy:
588 case Op_EncodeISOArray: {
589 add_local_var(n, PointsToNode::ArgEscape);
590 delayed_worklist->push(n); // Process it later.
591 break;
592 }
593 case Op_ThreadLocal: {
594 add_java_object(n, PointsToNode::ArgEscape);
595 break;
596 }
597 default:
598 ; // Do nothing for nodes not related to EA.
599 }
600 return;
601 }
602
603 #ifdef ASSERT
604 #define ELSE_FAIL(name) \
605 /* Should not be called for not pointer type. */ \
606 n->dump(1); \
607 assert(false, name); \
608 break;
609 #else
610 #define ELSE_FAIL(name) \
611 break;
612 #endif
613
614 // Add final simple edges to graph.
615 void ConnectionGraph::add_final_edges(Node *n) {
616 PointsToNode* n_ptn = ptnode_adr(n->_idx);
617 #ifdef ASSERT
618 if (_verify && n_ptn->is_JavaObject())
619 return; // This method does not change graph for JavaObject.
620 #endif
621
622 if (n->is_Call()) {
623 process_call_arguments(n->as_Call());
624 return;
625 }
626 assert(n->is_Store() || n->is_LoadStore() ||
627 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
628 "node should be registered already");
629 int opcode = n->Opcode();
630 switch (opcode) {
631 case Op_AddP: {
632 Node* base = get_addp_base(n);
633 PointsToNode* ptn_base = ptnode_adr(base->_idx);
634 assert(ptn_base != NULL, "field's base should be registered");
635 add_base(n_ptn->as_Field(), ptn_base);
636 break;
637 }
638 case Op_CastPP:
639 case Op_CheckCastPP:
640 case Op_EncodeP:
641 case Op_DecodeN:
642 case Op_EncodePKlass:
643 case Op_DecodeNKlass: {
644 add_local_var_and_edge(n, PointsToNode::NoEscape,
645 n->in(1), NULL);
646 break;
647 }
648 case Op_CMoveP: {
649 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
650 Node* in = n->in(i);
651 if (in == NULL)
652 continue; // ignore NULL
653 Node* uncast_in = in->uncast();
654 if (uncast_in->is_top() || uncast_in == n)
655 continue; // ignore top or inputs which go back this node
656 PointsToNode* ptn = ptnode_adr(in->_idx);
657 assert(ptn != NULL, "node should be registered");
658 add_edge(n_ptn, ptn);
659 }
660 break;
661 }
662 case Op_LoadP:
663 case Op_LoadN:
664 case Op_LoadPLocked: {
665 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
666 // ThreadLocal has RawPtr type.
667 const Type* t = _igvn->type(n);
668 if (t->make_ptr() != NULL) {
669 Node* adr = n->in(MemNode::Address);
670 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
671 break;
672 }
673 ELSE_FAIL("Op_LoadP");
674 }
675 case Op_Phi: {
676 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
677 // ThreadLocal has RawPtr type.
678 const Type* t = n->as_Phi()->type();
679 if (t->make_ptr() != NULL) {
680 for (uint i = 1; i < n->req(); i++) {
681 Node* in = n->in(i);
682 if (in == NULL)
683 continue; // ignore NULL
684 Node* uncast_in = in->uncast();
685 if (uncast_in->is_top() || uncast_in == n)
686 continue; // ignore top or inputs which go back this node
687 PointsToNode* ptn = ptnode_adr(in->_idx);
688 assert(ptn != NULL, "node should be registered");
689 add_edge(n_ptn, ptn);
690 }
691 break;
692 }
693 ELSE_FAIL("Op_Phi");
694 }
695 case Op_Proj: {
696 // we are only interested in the oop result projection from a call
697 if (n->as_Proj()->_con >= TypeFunc::Parms && n->in(0)->is_Call() &&
698 (n->in(0)->as_Call()->returns_pointer()|| n->bottom_type()->isa_oopptr())) {
699 assert((n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->as_Call()->returns_pointer()) ||
700 n->in(0)->as_Call()->tf()->returns_value_type_as_fields(), "what kind of oop return is it?");
701 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
702 break;
703 }
704 ELSE_FAIL("Op_Proj");
705 }
706 case Op_Rethrow: // Exception object escapes
707 case Op_Return: {
708 if (n->req() > TypeFunc::Parms &&
709 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
710 // Treat Return value as LocalVar with GlobalEscape escape state.
711 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
712 n->in(TypeFunc::Parms), NULL);
713 break;
714 }
715 ELSE_FAIL("Op_Return");
716 }
717 case Op_StoreP:
718 case Op_StoreN:
719 case Op_StoreNKlass:
720 case Op_StorePConditional:
721 case Op_CompareAndExchangeP:
722 case Op_CompareAndExchangeN:
723 case Op_CompareAndSwapP:
724 case Op_CompareAndSwapN:
725 case Op_WeakCompareAndSwapP:
726 case Op_WeakCompareAndSwapN:
727 case Op_GetAndSetP:
728 case Op_GetAndSetN: {
729 Node* adr = n->in(MemNode::Address);
730 const Type *adr_type = _igvn->type(adr);
731 adr_type = adr_type->make_ptr();
732 #ifdef ASSERT
733 if (adr_type == NULL) {
734 n->dump(1);
735 assert(adr_type != NULL, "dead node should not be on list");
736 break;
737 }
738 #endif
739 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
740 opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
741 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
742 }
743 if (adr_type->isa_oopptr() ||
744 (opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass) &&
745 (adr_type == TypeRawPtr::NOTNULL &&
746 adr->in(AddPNode::Address)->is_Proj() &&
747 adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
748 // Point Address to Value
749 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
750 assert(adr_ptn != NULL &&
751 adr_ptn->as_Field()->is_oop(), "node should be registered");
752 Node *val = n->in(MemNode::ValueIn);
753 PointsToNode* ptn = ptnode_adr(val->_idx);
754 assert(ptn != NULL, "node should be registered");
755 add_edge(adr_ptn, ptn);
756 break;
757 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
758 // Stored value escapes in unsafe access.
759 Node *val = n->in(MemNode::ValueIn);
760 PointsToNode* ptn = ptnode_adr(val->_idx);
761 assert(ptn != NULL, "node should be registered");
762 set_escape_state(ptn, PointsToNode::GlobalEscape);
763 // Add edge to object for unsafe access with offset.
764 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
765 assert(adr_ptn != NULL, "node should be registered");
766 if (adr_ptn->is_Field()) {
767 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
768 add_edge(adr_ptn, ptn);
769 }
770 break;
771 }
772 ELSE_FAIL("Op_StoreP");
773 }
774 case Op_AryEq:
775 case Op_HasNegatives:
776 case Op_StrComp:
777 case Op_StrEquals:
778 case Op_StrIndexOf:
779 case Op_StrIndexOfChar:
780 case Op_StrInflatedCopy:
781 case Op_StrCompressedCopy:
782 case Op_EncodeISOArray: {
783 // char[]/byte[] arrays passed to string intrinsic do not escape but
784 // they are not scalar replaceable. Adjust escape state for them.
785 // Start from in(2) edge since in(1) is memory edge.
786 for (uint i = 2; i < n->req(); i++) {
787 Node* adr = n->in(i);
788 const Type* at = _igvn->type(adr);
789 if (!adr->is_top() && at->isa_ptr()) {
790 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
791 at->isa_ptr() != NULL, "expecting a pointer");
792 if (adr->is_AddP()) {
793 adr = get_addp_base(adr);
794 }
795 PointsToNode* ptn = ptnode_adr(adr->_idx);
796 assert(ptn != NULL, "node should be registered");
797 add_edge(n_ptn, ptn);
798 }
799 }
800 break;
801 }
802 default: {
803 // This method should be called only for EA specific nodes which may
804 // miss some edges when they were created.
805 #ifdef ASSERT
806 n->dump(1);
807 #endif
808 guarantee(false, "unknown node");
809 }
810 }
811 return;
812 }
813
814 void ConnectionGraph::add_call_node(CallNode* call) {
815 assert(call->returns_pointer() || call->tf()->returns_value_type_as_fields(), "only for call which returns pointer");
816 uint call_idx = call->_idx;
817 if (call->is_Allocate()) {
818 Node* k = call->in(AllocateNode::KlassNode);
819 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
820 assert(kt != NULL, "TypeKlassPtr required.");
821 ciKlass* cik = kt->klass();
822 PointsToNode::EscapeState es = PointsToNode::NoEscape;
823 bool scalar_replaceable = true;
824 if (call->is_AllocateArray()) {
825 if (!cik->is_array_klass()) { // StressReflectiveCode
826 es = PointsToNode::GlobalEscape;
827 } else {
828 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
829 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
830 // Not scalar replaceable if the length is not constant or too big.
831 scalar_replaceable = false;
832 }
833 }
834 } else { // Allocate instance
835 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
836 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
837 !cik->is_instance_klass() || // StressReflectiveCode
838 !cik->as_instance_klass()->can_be_instantiated() ||
839 cik->as_instance_klass()->has_finalizer()) {
840 es = PointsToNode::GlobalEscape;
841 }
842 }
843 add_java_object(call, es);
844 PointsToNode* ptn = ptnode_adr(call_idx);
845 if (!scalar_replaceable && ptn->scalar_replaceable()) {
846 ptn->set_scalar_replaceable(false);
847 }
848 } else if (call->is_CallStaticJava()) {
849 // Call nodes could be different types:
850 //
851 // 1. CallDynamicJavaNode (what happened during call is unknown):
852 //
853 // - mapped to GlobalEscape JavaObject node if oop is returned;
854 //
855 // - all oop arguments are escaping globally;
856 //
857 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
858 //
859 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
860 //
861 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
862 // - mapped to NoEscape JavaObject node if non-escaping object allocated
863 // during call is returned;
864 // - mapped to ArgEscape LocalVar node pointed to object arguments
865 // which are returned and does not escape during call;
866 //
867 // - oop arguments escaping status is defined by bytecode analysis;
868 //
869 // For a static call, we know exactly what method is being called.
870 // Use bytecode estimator to record whether the call's return value escapes.
871 ciMethod* meth = call->as_CallJava()->method();
872 if (meth == NULL) {
873 const char* name = call->as_CallStaticJava()->_name;
874 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
875 // Returns a newly allocated unescaped object.
876 add_java_object(call, PointsToNode::NoEscape);
877 ptnode_adr(call_idx)->set_scalar_replaceable(false);
878 } else if (meth->is_boxing_method()) {
879 // Returns boxing object
880 PointsToNode::EscapeState es;
881 vmIntrinsics::ID intr = meth->intrinsic_id();
882 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
883 // It does not escape if object is always allocated.
884 es = PointsToNode::NoEscape;
885 } else {
886 // It escapes globally if object could be loaded from cache.
887 es = PointsToNode::GlobalEscape;
888 }
889 add_java_object(call, es);
890 } else {
891 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
892 call_analyzer->copy_dependencies(_compile->dependencies());
893 if (call_analyzer->is_return_allocated()) {
894 // Returns a newly allocated unescaped object, simply
895 // update dependency information.
896 // Mark it as NoEscape so that objects referenced by
897 // it's fields will be marked as NoEscape at least.
898 add_java_object(call, PointsToNode::NoEscape);
899 ptnode_adr(call_idx)->set_scalar_replaceable(false);
900 } else {
901 // Determine whether any arguments are returned.
902 const TypeTuple* d = call->tf()->domain_cc();
903 bool ret_arg = false;
904 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
905 if (d->field_at(i)->isa_ptr() != NULL &&
906 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
907 ret_arg = true;
908 break;
909 }
910 }
911 if (ret_arg) {
912 add_local_var(call, PointsToNode::ArgEscape);
913 } else {
914 // Returns unknown object.
915 map_ideal_node(call, phantom_obj);
916 }
917 }
918 }
919 } else {
920 // An other type of call, assume the worst case:
921 // returned value is unknown and globally escapes.
922 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
923 map_ideal_node(call, phantom_obj);
924 }
925 }
926
927 void ConnectionGraph::process_call_arguments(CallNode *call) {
928 bool is_arraycopy = false;
929 switch (call->Opcode()) {
930 #ifdef ASSERT
931 case Op_Allocate:
932 case Op_AllocateArray:
933 case Op_Lock:
934 case Op_Unlock:
935 assert(false, "should be done already");
936 break;
937 #endif
938 case Op_ArrayCopy:
939 case Op_CallLeafNoFP:
940 // Most array copies are ArrayCopy nodes at this point but there
941 // are still a few direct calls to the copy subroutines (See
942 // PhaseStringOpts::copy_string())
943 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
944 call->as_CallLeaf()->is_call_to_arraycopystub();
945 // fall through
946 case Op_CallLeaf: {
947 // Stub calls, objects do not escape but they are not scale replaceable.
948 // Adjust escape state for outgoing arguments.
949 const TypeTuple * d = call->tf()->domain_sig();
950 bool src_has_oops = false;
951 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
952 const Type* at = d->field_at(i);
953 Node *arg = call->in(i);
954 if (arg == NULL) {
955 continue;
956 }
957 const Type *aat = _igvn->type(arg);
958 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
959 continue;
960 if (arg->is_AddP()) {
961 //
962 // The inline_native_clone() case when the arraycopy stub is called
963 // after the allocation before Initialize and CheckCastPP nodes.
964 // Or normal arraycopy for object arrays case.
965 //
966 // Set AddP's base (Allocate) as not scalar replaceable since
967 // pointer to the base (with offset) is passed as argument.
968 //
969 arg = get_addp_base(arg);
970 }
971 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
972 assert(arg_ptn != NULL, "should be registered");
973 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
974 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
975 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
976 aat->isa_ptr() != NULL, "expecting an Ptr");
977 bool arg_has_oops = aat->isa_oopptr() &&
978 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
979 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
980 if (i == TypeFunc::Parms) {
981 src_has_oops = arg_has_oops;
982 }
983 //
984 // src or dst could be j.l.Object when other is basic type array:
985 //
986 // arraycopy(char[],0,Object*,0,size);
987 // arraycopy(Object*,0,char[],0,size);
988 //
989 // Don't add edges in such cases.
990 //
991 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
992 arg_has_oops && (i > TypeFunc::Parms);
993 #ifdef ASSERT
994 if (!(is_arraycopy ||
995 (call->as_CallLeaf()->_name != NULL &&
996 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
1002 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
1003 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
1004 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
1005 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
1006 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
1007 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
1008 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
1009 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
1010 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
1011 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1012 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1013 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1014 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1015 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1016 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1017 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1018 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1019 ))) {
1020 call->dump();
1021 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1022 }
1023 #endif
1024 // Always process arraycopy's destination object since
1025 // we need to add all possible edges to references in
1026 // source object.
1027 if (arg_esc >= PointsToNode::ArgEscape &&
1028 !arg_is_arraycopy_dest) {
1029 continue;
1030 }
1031 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1032 if (call->is_ArrayCopy()) {
1033 ArrayCopyNode* ac = call->as_ArrayCopy();
1034 if (ac->is_clonebasic() ||
1035 ac->is_arraycopy_validated() ||
1036 ac->is_copyof_validated() ||
1037 ac->is_copyofrange_validated()) {
1038 es = PointsToNode::NoEscape;
1039 }
1040 }
1041 set_escape_state(arg_ptn, es);
1042 if (arg_is_arraycopy_dest) {
1043 Node* src = call->in(TypeFunc::Parms);
1044 if (src->is_AddP()) {
1045 src = get_addp_base(src);
1046 }
1047 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1048 assert(src_ptn != NULL, "should be registered");
1049 if (arg_ptn != src_ptn) {
1050 // Special arraycopy edge:
1051 // A destination object's field can't have the source object
1052 // as base since objects escape states are not related.
1053 // Only escape state of destination object's fields affects
1054 // escape state of fields in source object.
1055 add_arraycopy(call, es, src_ptn, arg_ptn);
1056 }
1057 }
1058 }
1059 }
1060 break;
1061 }
1062 case Op_CallStaticJava: {
1063 // For a static call, we know exactly what method is being called.
1064 // Use bytecode estimator to record the call's escape affects
1065 #ifdef ASSERT
1066 const char* name = call->as_CallStaticJava()->_name;
1067 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1068 #endif
1069 ciMethod* meth = call->as_CallJava()->method();
1070 if ((meth != NULL) && meth->is_boxing_method()) {
1071 break; // Boxing methods do not modify any oops.
1072 }
1073 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1074 // fall-through if not a Java method or no analyzer information
1075 if (call_analyzer != NULL) {
1076 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1077 const TypeTuple* d = call->tf()->domain_cc();
1078 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1079 const Type* at = d->field_at(i);
1080 int k = i - TypeFunc::Parms;
1081 Node* arg = call->in(i);
1082 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1083 if (at->isa_ptr() != NULL &&
1084 call_analyzer->is_arg_returned(k)) {
1085 // The call returns arguments.
1086 if (call_ptn != NULL) { // Is call's result used?
1087 assert(call_ptn->is_LocalVar(), "node should be registered");
1088 assert(arg_ptn != NULL, "node should be registered");
1089 add_edge(call_ptn, arg_ptn);
1090 }
1091 }
1092 if (at->isa_oopptr() != NULL &&
1093 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1094 if (!call_analyzer->is_arg_stack(k)) {
1095 // The argument global escapes
1096 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1097 } else {
1098 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1099 if (!call_analyzer->is_arg_local(k)) {
1100 // The argument itself doesn't escape, but any fields might
1101 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1102 }
1103 }
1104 }
1105 }
1106 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1107 // The call returns arguments.
1108 assert(call_ptn->edge_count() > 0, "sanity");
1109 if (!call_analyzer->is_return_local()) {
1110 // Returns also unknown object.
1111 add_edge(call_ptn, phantom_obj);
1112 }
1113 }
1114 break;
1115 }
1116 }
1117 default: {
1118 // Fall-through here if not a Java method or no analyzer information
1119 // or some other type of call, assume the worst case: all arguments
1120 // globally escape.
1121 const TypeTuple* d = call->tf()->domain_cc();
1122 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1123 const Type* at = d->field_at(i);
1124 if (at->isa_oopptr() != NULL) {
1125 Node* arg = call->in(i);
1126 if (arg->is_AddP()) {
1127 arg = get_addp_base(arg);
1128 }
1129 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1130 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1131 }
1132 }
1133 }
1134 }
1135 }
1136
1137
1138 // Finish Graph construction.
1139 bool ConnectionGraph::complete_connection_graph(
1140 GrowableArray<PointsToNode*>& ptnodes_worklist,
1141 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1142 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1143 GrowableArray<FieldNode*>& oop_fields_worklist) {
1144 // Normally only 1-3 passes needed to build Connection Graph depending
1145 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1146 // Set limit to 20 to catch situation when something did go wrong and
1147 // bailout Escape Analysis.
1148 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1149 #define CG_BUILD_ITER_LIMIT 20
1150
1151 // Propagate GlobalEscape and ArgEscape escape states and check that
1152 // we still have non-escaping objects. The method pushs on _worklist
1153 // Field nodes which reference phantom_object.
1154 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1155 return false; // Nothing to do.
1156 }
1157 // Now propagate references to all JavaObject nodes.
1158 int java_objects_length = java_objects_worklist.length();
1159 elapsedTimer time;
1160 bool timeout = false;
1161 int new_edges = 1;
1162 int iterations = 0;
1163 do {
1164 while ((new_edges > 0) &&
1165 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1166 double start_time = time.seconds();
1167 time.start();
1168 new_edges = 0;
1169 // Propagate references to phantom_object for nodes pushed on _worklist
1170 // by find_non_escaped_objects() and find_field_value().
1171 new_edges += add_java_object_edges(phantom_obj, false);
1172 for (int next = 0; next < java_objects_length; ++next) {
1173 JavaObjectNode* ptn = java_objects_worklist.at(next);
1174 new_edges += add_java_object_edges(ptn, true);
1175
1176 #define SAMPLE_SIZE 4
1177 if ((next % SAMPLE_SIZE) == 0) {
1178 // Each 4 iterations calculate how much time it will take
1179 // to complete graph construction.
1180 time.stop();
1181 // Poll for requests from shutdown mechanism to quiesce compiler
1182 // because Connection graph construction may take long time.
1183 CompileBroker::maybe_block();
1184 double stop_time = time.seconds();
1185 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1186 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1187 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1188 timeout = true;
1189 break; // Timeout
1190 }
1191 start_time = stop_time;
1192 time.start();
1193 }
1194 #undef SAMPLE_SIZE
1195
1196 }
1197 if (timeout) break;
1198 if (new_edges > 0) {
1199 // Update escape states on each iteration if graph was updated.
1200 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1201 return false; // Nothing to do.
1202 }
1203 }
1204 time.stop();
1205 if (time.seconds() >= EscapeAnalysisTimeout) {
1206 timeout = true;
1207 break;
1208 }
1209 }
1210 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1211 time.start();
1212 // Find fields which have unknown value.
1213 int fields_length = oop_fields_worklist.length();
1214 for (int next = 0; next < fields_length; next++) {
1215 FieldNode* field = oop_fields_worklist.at(next);
1216 if (field->edge_count() == 0) {
1217 new_edges += find_field_value(field);
1218 // This code may added new edges to phantom_object.
1219 // Need an other cycle to propagate references to phantom_object.
1220 }
1221 }
1222 time.stop();
1223 if (time.seconds() >= EscapeAnalysisTimeout) {
1224 timeout = true;
1225 break;
1226 }
1227 } else {
1228 new_edges = 0; // Bailout
1229 }
1230 } while (new_edges > 0);
1231
1232 // Bailout if passed limits.
1233 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1234 Compile* C = _compile;
1235 if (C->log() != NULL) {
1236 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1237 C->log()->text("%s", timeout ? "time" : "iterations");
1238 C->log()->end_elem(" limit'");
1239 }
1240 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1241 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1242 // Possible infinite build_connection_graph loop,
1243 // bailout (no changes to ideal graph were made).
1244 return false;
1245 }
1246 #ifdef ASSERT
1247 if (Verbose && PrintEscapeAnalysis) {
1248 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1249 iterations, nodes_size(), ptnodes_worklist.length());
1250 }
1251 #endif
1252
1253 #undef CG_BUILD_ITER_LIMIT
1254
1255 // Find fields initialized by NULL for non-escaping Allocations.
1256 int non_escaped_length = non_escaped_worklist.length();
1257 for (int next = 0; next < non_escaped_length; next++) {
1258 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1259 PointsToNode::EscapeState es = ptn->escape_state();
1260 assert(es <= PointsToNode::ArgEscape, "sanity");
1261 if (es == PointsToNode::NoEscape) {
1262 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1263 // Adding references to NULL object does not change escape states
1264 // since it does not escape. Also no fields are added to NULL object.
1265 add_java_object_edges(null_obj, false);
1266 }
1267 }
1268 Node* n = ptn->ideal_node();
1269 if (n->is_Allocate()) {
1270 // The object allocated by this Allocate node will never be
1271 // seen by an other thread. Mark it so that when it is
1272 // expanded no MemBarStoreStore is added.
1273 InitializeNode* ini = n->as_Allocate()->initialization();
1274 if (ini != NULL)
1275 ini->set_does_not_escape();
1276 }
1277 }
1278 return true; // Finished graph construction.
1279 }
1280
1281 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1282 // and check that we still have non-escaping java objects.
1283 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1284 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1285 GrowableArray<PointsToNode*> escape_worklist;
1286 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1287 int ptnodes_length = ptnodes_worklist.length();
1288 for (int next = 0; next < ptnodes_length; ++next) {
1289 PointsToNode* ptn = ptnodes_worklist.at(next);
1290 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1291 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1292 escape_worklist.push(ptn);
1293 }
1294 }
1295 // Set escape states to referenced nodes (edges list).
1296 while (escape_worklist.length() > 0) {
1297 PointsToNode* ptn = escape_worklist.pop();
1298 PointsToNode::EscapeState es = ptn->escape_state();
1299 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1300 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1301 es >= PointsToNode::ArgEscape) {
1302 // GlobalEscape or ArgEscape state of field means it has unknown value.
1303 if (add_edge(ptn, phantom_obj)) {
1304 // New edge was added
1305 add_field_uses_to_worklist(ptn->as_Field());
1306 }
1307 }
1308 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1309 PointsToNode* e = i.get();
1310 if (e->is_Arraycopy()) {
1311 assert(ptn->arraycopy_dst(), "sanity");
1312 // Propagate only fields escape state through arraycopy edge.
1313 if (e->fields_escape_state() < field_es) {
1314 set_fields_escape_state(e, field_es);
1315 escape_worklist.push(e);
1316 }
1317 } else if (es >= field_es) {
1318 // fields_escape_state is also set to 'es' if it is less than 'es'.
1319 if (e->escape_state() < es) {
1320 set_escape_state(e, es);
1321 escape_worklist.push(e);
1322 }
1323 } else {
1324 // Propagate field escape state.
1325 bool es_changed = false;
1326 if (e->fields_escape_state() < field_es) {
1327 set_fields_escape_state(e, field_es);
1328 es_changed = true;
1329 }
1330 if ((e->escape_state() < field_es) &&
1331 e->is_Field() && ptn->is_JavaObject() &&
1332 e->as_Field()->is_oop()) {
1333 // Change escape state of referenced fields.
1334 set_escape_state(e, field_es);
1335 es_changed = true;
1336 } else if (e->escape_state() < es) {
1337 set_escape_state(e, es);
1338 es_changed = true;
1339 }
1340 if (es_changed) {
1341 escape_worklist.push(e);
1342 }
1343 }
1344 }
1345 }
1346 // Remove escaped objects from non_escaped list.
1347 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1348 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1349 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1350 non_escaped_worklist.delete_at(next);
1351 }
1352 if (ptn->escape_state() == PointsToNode::NoEscape) {
1353 // Find fields in non-escaped allocations which have unknown value.
1354 find_init_values(ptn, phantom_obj, NULL);
1355 }
1356 }
1357 return (non_escaped_worklist.length() > 0);
1358 }
1359
1360 // Add all references to JavaObject node by walking over all uses.
1361 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1362 int new_edges = 0;
1363 if (populate_worklist) {
1364 // Populate _worklist by uses of jobj's uses.
1365 for (UseIterator i(jobj); i.has_next(); i.next()) {
1366 PointsToNode* use = i.get();
1367 if (use->is_Arraycopy())
1368 continue;
1369 add_uses_to_worklist(use);
1370 if (use->is_Field() && use->as_Field()->is_oop()) {
1371 // Put on worklist all field's uses (loads) and
1372 // related field nodes (same base and offset).
1373 add_field_uses_to_worklist(use->as_Field());
1374 }
1375 }
1376 }
1377 for (int l = 0; l < _worklist.length(); l++) {
1378 PointsToNode* use = _worklist.at(l);
1379 if (PointsToNode::is_base_use(use)) {
1380 // Add reference from jobj to field and from field to jobj (field's base).
1381 use = PointsToNode::get_use_node(use)->as_Field();
1382 if (add_base(use->as_Field(), jobj)) {
1383 new_edges++;
1384 }
1385 continue;
1386 }
1387 assert(!use->is_JavaObject(), "sanity");
1388 if (use->is_Arraycopy()) {
1389 if (jobj == null_obj) // NULL object does not have field edges
1390 continue;
1391 // Added edge from Arraycopy node to arraycopy's source java object
1392 if (add_edge(use, jobj)) {
1393 jobj->set_arraycopy_src();
1394 new_edges++;
1395 }
1396 // and stop here.
1397 continue;
1398 }
1399 if (!add_edge(use, jobj))
1400 continue; // No new edge added, there was such edge already.
1401 new_edges++;
1402 if (use->is_LocalVar()) {
1403 add_uses_to_worklist(use);
1404 if (use->arraycopy_dst()) {
1405 for (EdgeIterator i(use); i.has_next(); i.next()) {
1406 PointsToNode* e = i.get();
1407 if (e->is_Arraycopy()) {
1408 if (jobj == null_obj) // NULL object does not have field edges
1409 continue;
1410 // Add edge from arraycopy's destination java object to Arraycopy node.
1411 if (add_edge(jobj, e)) {
1412 new_edges++;
1413 jobj->set_arraycopy_dst();
1414 }
1415 }
1416 }
1417 }
1418 } else {
1419 // Added new edge to stored in field values.
1420 // Put on worklist all field's uses (loads) and
1421 // related field nodes (same base and offset).
1422 add_field_uses_to_worklist(use->as_Field());
1423 }
1424 }
1425 _worklist.clear();
1426 _in_worklist.Reset();
1427 return new_edges;
1428 }
1429
1430 // Put on worklist all related field nodes.
1431 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1432 assert(field->is_oop(), "sanity");
1433 int offset = field->offset();
1434 add_uses_to_worklist(field);
1435 // Loop over all bases of this field and push on worklist Field nodes
1436 // with the same offset and base (since they may reference the same field).
1437 for (BaseIterator i(field); i.has_next(); i.next()) {
1438 PointsToNode* base = i.get();
1439 add_fields_to_worklist(field, base);
1440 // Check if the base was source object of arraycopy and go over arraycopy's
1441 // destination objects since values stored to a field of source object are
1442 // accessable by uses (loads) of fields of destination objects.
1443 if (base->arraycopy_src()) {
1444 for (UseIterator j(base); j.has_next(); j.next()) {
1445 PointsToNode* arycp = j.get();
1446 if (arycp->is_Arraycopy()) {
1447 for (UseIterator k(arycp); k.has_next(); k.next()) {
1448 PointsToNode* abase = k.get();
1449 if (abase->arraycopy_dst() && abase != base) {
1450 // Look for the same arraycopy reference.
1451 add_fields_to_worklist(field, abase);
1452 }
1453 }
1454 }
1455 }
1456 }
1457 }
1458 }
1459
1460 // Put on worklist all related field nodes.
1461 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1462 int offset = field->offset();
1463 if (base->is_LocalVar()) {
1464 for (UseIterator j(base); j.has_next(); j.next()) {
1465 PointsToNode* f = j.get();
1466 if (PointsToNode::is_base_use(f)) { // Field
1467 f = PointsToNode::get_use_node(f);
1468 if (f == field || !f->as_Field()->is_oop())
1469 continue;
1470 int offs = f->as_Field()->offset();
1471 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1472 add_to_worklist(f);
1473 }
1474 }
1475 }
1476 } else {
1477 assert(base->is_JavaObject(), "sanity");
1478 if (// Skip phantom_object since it is only used to indicate that
1479 // this field's content globally escapes.
1480 (base != phantom_obj) &&
1481 // NULL object node does not have fields.
1482 (base != null_obj)) {
1483 for (EdgeIterator i(base); i.has_next(); i.next()) {
1484 PointsToNode* f = i.get();
1485 // Skip arraycopy edge since store to destination object field
1486 // does not update value in source object field.
1487 if (f->is_Arraycopy()) {
1488 assert(base->arraycopy_dst(), "sanity");
1489 continue;
1490 }
1491 if (f == field || !f->as_Field()->is_oop())
1492 continue;
1493 int offs = f->as_Field()->offset();
1494 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1495 add_to_worklist(f);
1496 }
1497 }
1498 }
1499 }
1500 }
1501
1502 // Find fields which have unknown value.
1503 int ConnectionGraph::find_field_value(FieldNode* field) {
1504 // Escaped fields should have init value already.
1505 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1506 int new_edges = 0;
1507 for (BaseIterator i(field); i.has_next(); i.next()) {
1508 PointsToNode* base = i.get();
1509 if (base->is_JavaObject()) {
1510 // Skip Allocate's fields which will be processed later.
1511 if (base->ideal_node()->is_Allocate())
1512 return 0;
1513 assert(base == null_obj, "only NULL ptr base expected here");
1514 }
1515 }
1516 if (add_edge(field, phantom_obj)) {
1517 // New edge was added
1518 new_edges++;
1519 add_field_uses_to_worklist(field);
1520 }
1521 return new_edges;
1522 }
1523
1524 // Find fields initializing values for allocations.
1525 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1526 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1527 int new_edges = 0;
1528 Node* alloc = pta->ideal_node();
1529 if (init_val == phantom_obj) {
1530 // Do nothing for Allocate nodes since its fields values are
1531 // "known" unless they are initialized by arraycopy/clone.
1532 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1533 return 0;
1534 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1535 #ifdef ASSERT
1536 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1537 const char* name = alloc->as_CallStaticJava()->_name;
1538 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1539 }
1540 #endif
1541 // Non-escaped allocation returned from Java or runtime call have
1542 // unknown values in fields.
1543 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1544 PointsToNode* field = i.get();
1545 if (field->is_Field() && field->as_Field()->is_oop()) {
1546 if (add_edge(field, phantom_obj)) {
1547 // New edge was added
1548 new_edges++;
1549 add_field_uses_to_worklist(field->as_Field());
1550 }
1551 }
1552 }
1553 return new_edges;
1554 }
1555 assert(init_val == null_obj, "sanity");
1556 // Do nothing for Call nodes since its fields values are unknown.
1557 if (!alloc->is_Allocate())
1558 return 0;
1559
1560 InitializeNode* ini = alloc->as_Allocate()->initialization();
1561 bool visited_bottom_offset = false;
1562 GrowableArray<int> offsets_worklist;
1563
1564 // Check if an oop field's initializing value is recorded and add
1565 // a corresponding NULL if field's value if it is not recorded.
1566 // Connection Graph does not record a default initialization by NULL
1567 // captured by Initialize node.
1568 //
1569 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1570 PointsToNode* field = i.get(); // Field (AddP)
1571 if (!field->is_Field() || !field->as_Field()->is_oop())
1572 continue; // Not oop field
1573 int offset = field->as_Field()->offset();
1574 if (offset == Type::OffsetBot) {
1575 if (!visited_bottom_offset) {
1576 // OffsetBot is used to reference array's element,
1577 // always add reference to NULL to all Field nodes since we don't
1578 // known which element is referenced.
1579 if (add_edge(field, null_obj)) {
1580 // New edge was added
1581 new_edges++;
1582 add_field_uses_to_worklist(field->as_Field());
1583 visited_bottom_offset = true;
1584 }
1585 }
1586 } else {
1587 // Check only oop fields.
1588 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1589 if (adr_type->isa_rawptr()) {
1590 #ifdef ASSERT
1591 // Raw pointers are used for initializing stores so skip it
1592 // since it should be recorded already
1593 Node* base = get_addp_base(field->ideal_node());
1594 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1595 (base->in(0) == alloc),"unexpected pointer type");
1596 #endif
1597 continue;
1598 }
1599 if (!offsets_worklist.contains(offset)) {
1600 offsets_worklist.append(offset);
1601 Node* value = NULL;
1602 if (ini != NULL) {
1603 // StoreP::memory_type() == T_ADDRESS
1604 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1605 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1606 // Make sure initializing store has the same type as this AddP.
1607 // This AddP may reference non existing field because it is on a
1608 // dead branch of bimorphic call which is not eliminated yet.
1609 if (store != NULL && store->is_Store() &&
1610 store->as_Store()->memory_type() == ft) {
1611 value = store->in(MemNode::ValueIn);
1612 #ifdef ASSERT
1613 if (VerifyConnectionGraph) {
1614 // Verify that AddP already points to all objects the value points to.
1615 PointsToNode* val = ptnode_adr(value->_idx);
1616 assert((val != NULL), "should be processed already");
1617 PointsToNode* missed_obj = NULL;
1618 if (val->is_JavaObject()) {
1619 if (!field->points_to(val->as_JavaObject())) {
1620 missed_obj = val;
1621 }
1622 } else {
1623 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1624 tty->print_cr("----------init store has invalid value -----");
1625 store->dump();
1626 val->dump();
1627 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1628 }
1629 for (EdgeIterator j(val); j.has_next(); j.next()) {
1630 PointsToNode* obj = j.get();
1631 if (obj->is_JavaObject()) {
1632 if (!field->points_to(obj->as_JavaObject())) {
1633 missed_obj = obj;
1634 break;
1635 }
1636 }
1637 }
1638 }
1639 if (missed_obj != NULL) {
1640 tty->print_cr("----------field---------------------------------");
1641 field->dump();
1642 tty->print_cr("----------missed referernce to object-----------");
1643 missed_obj->dump();
1644 tty->print_cr("----------object referernced by init store -----");
1645 store->dump();
1646 val->dump();
1647 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1648 }
1649 }
1650 #endif
1651 } else {
1652 // There could be initializing stores which follow allocation.
1653 // For example, a volatile field store is not collected
1654 // by Initialize node.
1655 //
1656 // Need to check for dependent loads to separate such stores from
1657 // stores which follow loads. For now, add initial value NULL so
1658 // that compare pointers optimization works correctly.
1659 }
1660 }
1661 if (value == NULL) {
1662 // A field's initializing value was not recorded. Add NULL.
1663 if (add_edge(field, null_obj)) {
1664 // New edge was added
1665 new_edges++;
1666 add_field_uses_to_worklist(field->as_Field());
1667 }
1668 }
1669 }
1670 }
1671 }
1672 return new_edges;
1673 }
1674
1675 // Adjust scalar_replaceable state after Connection Graph is built.
1676 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1677 // Search for non-escaping objects which are not scalar replaceable
1678 // and mark them to propagate the state to referenced objects.
1679
1680 // 1. An object is not scalar replaceable if the field into which it is
1681 // stored has unknown offset (stored into unknown element of an array).
1682 //
1683 for (UseIterator i(jobj); i.has_next(); i.next()) {
1684 PointsToNode* use = i.get();
1685 if (use->is_Arraycopy()) {
1686 continue;
1687 }
1688 if (use->is_Field()) {
1689 FieldNode* field = use->as_Field();
1690 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1691 if (field->offset() == Type::OffsetBot) {
1692 jobj->set_scalar_replaceable(false);
1693 return;
1694 }
1695 // 2. An object is not scalar replaceable if the field into which it is
1696 // stored has multiple bases one of which is null.
1697 if (field->base_count() > 1) {
1698 for (BaseIterator i(field); i.has_next(); i.next()) {
1699 PointsToNode* base = i.get();
1700 if (base == null_obj) {
1701 jobj->set_scalar_replaceable(false);
1702 return;
1703 }
1704 }
1705 }
1706 }
1707 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1708 // 3. An object is not scalar replaceable if it is merged with other objects.
1709 for (EdgeIterator j(use); j.has_next(); j.next()) {
1710 PointsToNode* ptn = j.get();
1711 if (ptn->is_JavaObject() && ptn != jobj) {
1712 // Mark all objects.
1713 jobj->set_scalar_replaceable(false);
1714 ptn->set_scalar_replaceable(false);
1715 }
1716 }
1717 if (!jobj->scalar_replaceable()) {
1718 return;
1719 }
1720 }
1721
1722 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1723 if (j.get()->is_Arraycopy()) {
1724 continue;
1725 }
1726
1727 // Non-escaping object node should point only to field nodes.
1728 FieldNode* field = j.get()->as_Field();
1729 int offset = field->as_Field()->offset();
1730
1731 // 4. An object is not scalar replaceable if it has a field with unknown
1732 // offset (array's element is accessed in loop).
1733 if (offset == Type::OffsetBot) {
1734 jobj->set_scalar_replaceable(false);
1735 return;
1736 }
1737 // 5. Currently an object is not scalar replaceable if a LoadStore node
1738 // access its field since the field value is unknown after it.
1739 //
1740 Node* n = field->ideal_node();
1741 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1742 if (n->fast_out(i)->is_LoadStore()) {
1743 jobj->set_scalar_replaceable(false);
1744 return;
1745 }
1746 }
1747
1748 // 6. Or the address may point to more then one object. This may produce
1749 // the false positive result (set not scalar replaceable)
1750 // since the flow-insensitive escape analysis can't separate
1751 // the case when stores overwrite the field's value from the case
1752 // when stores happened on different control branches.
1753 //
1754 // Note: it will disable scalar replacement in some cases:
1755 //
1756 // Point p[] = new Point[1];
1757 // p[0] = new Point(); // Will be not scalar replaced
1758 //
1759 // but it will save us from incorrect optimizations in next cases:
1760 //
1761 // Point p[] = new Point[1];
1762 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1763 //
1764 if (field->base_count() > 1) {
1765 for (BaseIterator i(field); i.has_next(); i.next()) {
1766 PointsToNode* base = i.get();
1767 // Don't take into account LocalVar nodes which
1768 // may point to only one object which should be also
1769 // this field's base by now.
1770 if (base->is_JavaObject() && base != jobj) {
1771 // Mark all bases.
1772 jobj->set_scalar_replaceable(false);
1773 base->set_scalar_replaceable(false);
1774 }
1775 }
1776 }
1777 }
1778 }
1779
1780 #ifdef ASSERT
1781 void ConnectionGraph::verify_connection_graph(
1782 GrowableArray<PointsToNode*>& ptnodes_worklist,
1783 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1784 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1785 GrowableArray<Node*>& addp_worklist) {
1786 // Verify that graph is complete - no new edges could be added.
1787 int java_objects_length = java_objects_worklist.length();
1788 int non_escaped_length = non_escaped_worklist.length();
1789 int new_edges = 0;
1790 for (int next = 0; next < java_objects_length; ++next) {
1791 JavaObjectNode* ptn = java_objects_worklist.at(next);
1792 new_edges += add_java_object_edges(ptn, true);
1793 }
1794 assert(new_edges == 0, "graph was not complete");
1795 // Verify that escape state is final.
1796 int length = non_escaped_worklist.length();
1797 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1798 assert((non_escaped_length == non_escaped_worklist.length()) &&
1799 (non_escaped_length == length) &&
1800 (_worklist.length() == 0), "escape state was not final");
1801
1802 // Verify fields information.
1803 int addp_length = addp_worklist.length();
1804 for (int next = 0; next < addp_length; ++next ) {
1805 Node* n = addp_worklist.at(next);
1806 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1807 if (field->is_oop()) {
1808 // Verify that field has all bases
1809 Node* base = get_addp_base(n);
1810 PointsToNode* ptn = ptnode_adr(base->_idx);
1811 if (ptn->is_JavaObject()) {
1812 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1813 } else {
1814 assert(ptn->is_LocalVar(), "sanity");
1815 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1816 PointsToNode* e = i.get();
1817 if (e->is_JavaObject()) {
1818 assert(field->has_base(e->as_JavaObject()), "sanity");
1819 }
1820 }
1821 }
1822 // Verify that all fields have initializing values.
1823 if (field->edge_count() == 0) {
1824 tty->print_cr("----------field does not have references----------");
1825 field->dump();
1826 for (BaseIterator i(field); i.has_next(); i.next()) {
1827 PointsToNode* base = i.get();
1828 tty->print_cr("----------field has next base---------------------");
1829 base->dump();
1830 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1831 tty->print_cr("----------base has fields-------------------------");
1832 for (EdgeIterator j(base); j.has_next(); j.next()) {
1833 j.get()->dump();
1834 }
1835 tty->print_cr("----------base has references---------------------");
1836 for (UseIterator j(base); j.has_next(); j.next()) {
1837 j.get()->dump();
1838 }
1839 }
1840 }
1841 for (UseIterator i(field); i.has_next(); i.next()) {
1842 i.get()->dump();
1843 }
1844 assert(field->edge_count() > 0, "sanity");
1845 }
1846 }
1847 }
1848 }
1849 #endif
1850
1851 // Optimize ideal graph.
1852 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1853 GrowableArray<Node*>& storestore_worklist) {
1854 Compile* C = _compile;
1855 PhaseIterGVN* igvn = _igvn;
1856 if (EliminateLocks) {
1857 // Mark locks before changing ideal graph.
1858 int cnt = C->macro_count();
1859 for( int i=0; i < cnt; i++ ) {
1860 Node *n = C->macro_node(i);
1861 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1862 AbstractLockNode* alock = n->as_AbstractLock();
1863 if (!alock->is_non_esc_obj()) {
1864 if (not_global_escape(alock->obj_node())) {
1865 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1866 // The lock could be marked eliminated by lock coarsening
1867 // code during first IGVN before EA. Replace coarsened flag
1868 // to eliminate all associated locks/unlocks.
1869 #ifdef ASSERT
1870 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1871 #endif
1872 alock->set_non_esc_obj();
1873 }
1874 }
1875 }
1876 }
1877 }
1878
1879 if (OptimizePtrCompare) {
1880 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1881 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1882 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1883 // Optimize objects compare.
1884 while (ptr_cmp_worklist.length() != 0) {
1885 Node *n = ptr_cmp_worklist.pop();
1886 Node *res = optimize_ptr_compare(n);
1887 if (res != NULL) {
1888 #ifndef PRODUCT
1889 if (PrintOptimizePtrCompare) {
1890 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"));
1891 if (Verbose) {
1892 n->dump(1);
1893 }
1894 }
1895 #endif
1896 igvn->replace_node(n, res);
1897 }
1898 }
1899 // cleanup
1900 if (_pcmp_neq->outcnt() == 0)
1901 igvn->hash_delete(_pcmp_neq);
1902 if (_pcmp_eq->outcnt() == 0)
1903 igvn->hash_delete(_pcmp_eq);
1904 }
1905
1906 // For MemBarStoreStore nodes added in library_call.cpp, check
1907 // escape status of associated AllocateNode and optimize out
1908 // MemBarStoreStore node if the allocated object never escapes.
1909 while (storestore_worklist.length() != 0) {
1910 Node *n = storestore_worklist.pop();
1911 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1912 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1913 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1914 if (not_global_escape(alloc)) {
1915 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1916 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1917 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1918 igvn->register_new_node_with_optimizer(mb);
1919 igvn->replace_node(storestore, mb);
1920 }
1921 }
1922 }
1923
1924 // Optimize objects compare.
1925 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1926 assert(OptimizePtrCompare, "sanity");
1927 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1928 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1929 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1930 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1931 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1932 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1933
1934 // Check simple cases first.
1935 if (jobj1 != NULL) {
1936 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1937 if (jobj1 == jobj2) {
1938 // Comparing the same not escaping object.
1939 return _pcmp_eq;
1940 }
1941 Node* obj = jobj1->ideal_node();
1942 // Comparing not escaping allocation.
1943 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1944 !ptn2->points_to(jobj1)) {
1945 return _pcmp_neq; // This includes nullness check.
1946 }
1947 }
1948 }
1949 if (jobj2 != NULL) {
1950 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1951 Node* obj = jobj2->ideal_node();
1952 // Comparing not escaping allocation.
1953 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1954 !ptn1->points_to(jobj2)) {
1955 return _pcmp_neq; // This includes nullness check.
1956 }
1957 }
1958 }
1959 if (jobj1 != NULL && jobj1 != phantom_obj &&
1960 jobj2 != NULL && jobj2 != phantom_obj &&
1961 jobj1->ideal_node()->is_Con() &&
1962 jobj2->ideal_node()->is_Con()) {
1963 // Klass or String constants compare. Need to be careful with
1964 // compressed pointers - compare types of ConN and ConP instead of nodes.
1965 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1966 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1967 if (t1->make_ptr() == t2->make_ptr()) {
1968 return _pcmp_eq;
1969 } else {
1970 return _pcmp_neq;
1971 }
1972 }
1973 if (ptn1->meet(ptn2)) {
1974 return NULL; // Sets are not disjoint
1975 }
1976
1977 // Sets are disjoint.
1978 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1979 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1980 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1981 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1982 if (set1_has_unknown_ptr && set2_has_null_ptr ||
1983 set2_has_unknown_ptr && set1_has_null_ptr) {
1984 // Check nullness of unknown object.
1985 return NULL;
1986 }
1987
1988 // Disjointness by itself is not sufficient since
1989 // alias analysis is not complete for escaped objects.
1990 // Disjoint sets are definitely unrelated only when
1991 // at least one set has only not escaping allocations.
1992 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1993 if (ptn1->non_escaping_allocation()) {
1994 return _pcmp_neq;
1995 }
1996 }
1997 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1998 if (ptn2->non_escaping_allocation()) {
1999 return _pcmp_neq;
2000 }
2001 }
2002 return NULL;
2003 }
2004
2005 // Connection Graph constuction functions.
2006
2007 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2008 PointsToNode* ptadr = _nodes.at(n->_idx);
2009 if (ptadr != NULL) {
2010 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2011 return;
2012 }
2013 Compile* C = _compile;
2014 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2015 _nodes.at_put(n->_idx, ptadr);
2016 }
2017
2018 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2019 PointsToNode* ptadr = _nodes.at(n->_idx);
2020 if (ptadr != NULL) {
2021 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2022 return;
2023 }
2024 Compile* C = _compile;
2025 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2026 _nodes.at_put(n->_idx, ptadr);
2027 }
2028
2029 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2030 PointsToNode* ptadr = _nodes.at(n->_idx);
2031 if (ptadr != NULL) {
2032 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2033 return;
2034 }
2035 bool unsafe = false;
2036 bool is_oop = is_oop_field(n, offset, &unsafe);
2037 if (unsafe) {
2038 es = PointsToNode::GlobalEscape;
2039 }
2040 Compile* C = _compile;
2041 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2042 _nodes.at_put(n->_idx, field);
2043 }
2044
2045 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2046 PointsToNode* src, PointsToNode* dst) {
2047 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2048 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2049 PointsToNode* ptadr = _nodes.at(n->_idx);
2050 if (ptadr != NULL) {
2051 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2052 return;
2053 }
2054 Compile* C = _compile;
2055 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2056 _nodes.at_put(n->_idx, ptadr);
2057 // Add edge from arraycopy node to source object.
2058 (void)add_edge(ptadr, src);
2059 src->set_arraycopy_src();
2060 // Add edge from destination object to arraycopy node.
2061 (void)add_edge(dst, ptadr);
2062 dst->set_arraycopy_dst();
2063 }
2064
2065 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2066 const Type* adr_type = n->as_AddP()->bottom_type();
2067 int field_offset = adr_type->isa_aryptr() ? adr_type->isa_aryptr()->field_offset().get() : Type::OffsetBot;
2068 BasicType bt = T_INT;
2069 if (offset == Type::OffsetBot && field_offset == Type::OffsetBot) {
2070 // Check only oop fields.
2071 if (!adr_type->isa_aryptr() ||
2072 (adr_type->isa_aryptr()->klass() == NULL) ||
2073 adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
2074 // OffsetBot is used to reference array's element. Ignore first AddP.
2075 if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
2076 bt = T_OBJECT;
2077 }
2078 }
2079 } else if (offset != oopDesc::klass_offset_in_bytes()) {
2080 if (adr_type->isa_instptr() || adr_type->isa_valuetypeptr()) {
2081 ciField* field = _compile->alias_type(adr_type->is_ptr())->field();
2082 if (field != NULL) {
2083 bt = field->layout_type();
2084 } else {
2085 // Check for unsafe oop field access
2086 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2087 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2088 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2089 bt = T_OBJECT;
2090 (*unsafe) = true;
2091 }
2092 }
2093 } else if (adr_type->isa_aryptr()) {
2094 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2095 // Ignore array length load.
2096 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2097 // Ignore first AddP.
2098 } else {
2099 const Type* elemtype = adr_type->isa_aryptr()->elem();
2100 if (elemtype->isa_valuetype()) {
2101 assert(field_offset != Type::OffsetBot, "invalid field offset");
2102 ciValueKlass* vk = elemtype->is_valuetype()->value_klass();
2103 field_offset += vk->first_field_offset();
2104 bt = vk->get_field_by_offset(field_offset, false)->layout_type();
2105 } else {
2106 bt = elemtype->array_element_basic_type();
2107 }
2108 }
2109 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2110 // Allocation initialization, ThreadLocal field access, unsafe access
2111 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2112 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2113 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN)) {
2114 bt = T_OBJECT;
2115 }
2116 }
2117 }
2118 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2119 }
2120
2121 // Returns unique pointed java object or NULL.
2122 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2123 assert(!_collecting, "should not call when contructed graph");
2124 // If the node was created after the escape computation we can't answer.
2125 uint idx = n->_idx;
2126 if (idx >= nodes_size()) {
2127 return NULL;
2128 }
2129 PointsToNode* ptn = ptnode_adr(idx);
2130 if (ptn->is_JavaObject()) {
2131 return ptn->as_JavaObject();
2132 }
2133 assert(ptn->is_LocalVar(), "sanity");
2134 // Check all java objects it points to.
2135 JavaObjectNode* jobj = NULL;
2136 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2137 PointsToNode* e = i.get();
2138 if (e->is_JavaObject()) {
2139 if (jobj == NULL) {
2140 jobj = e->as_JavaObject();
2141 } else if (jobj != e) {
2142 return NULL;
2143 }
2144 }
2145 }
2146 return jobj;
2147 }
2148
2149 // Return true if this node points only to non-escaping allocations.
2150 bool PointsToNode::non_escaping_allocation() {
2151 if (is_JavaObject()) {
2152 Node* n = ideal_node();
2153 if (n->is_Allocate() || n->is_CallStaticJava()) {
2154 return (escape_state() == PointsToNode::NoEscape);
2155 } else {
2156 return false;
2157 }
2158 }
2159 assert(is_LocalVar(), "sanity");
2160 // Check all java objects it points to.
2161 for (EdgeIterator i(this); i.has_next(); i.next()) {
2162 PointsToNode* e = i.get();
2163 if (e->is_JavaObject()) {
2164 Node* n = e->ideal_node();
2165 if ((e->escape_state() != PointsToNode::NoEscape) ||
2166 !(n->is_Allocate() || n->is_CallStaticJava())) {
2167 return false;
2168 }
2169 }
2170 }
2171 return true;
2172 }
2173
2174 // Return true if we know the node does not escape globally.
2175 bool ConnectionGraph::not_global_escape(Node *n) {
2176 assert(!_collecting, "should not call during graph construction");
2177 // If the node was created after the escape computation we can't answer.
2178 uint idx = n->_idx;
2179 if (idx >= nodes_size()) {
2180 return false;
2181 }
2182 PointsToNode* ptn = ptnode_adr(idx);
2183 PointsToNode::EscapeState es = ptn->escape_state();
2184 // If we have already computed a value, return it.
2185 if (es >= PointsToNode::GlobalEscape)
2186 return false;
2187 if (ptn->is_JavaObject()) {
2188 return true; // (es < PointsToNode::GlobalEscape);
2189 }
2190 assert(ptn->is_LocalVar(), "sanity");
2191 // Check all java objects it points to.
2192 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2193 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2194 return false;
2195 }
2196 return true;
2197 }
2198
2199
2200 // Helper functions
2201
2202 // Return true if this node points to specified node or nodes it points to.
2203 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2204 if (is_JavaObject()) {
2205 return (this == ptn);
2206 }
2207 assert(is_LocalVar() || is_Field(), "sanity");
2208 for (EdgeIterator i(this); i.has_next(); i.next()) {
2209 if (i.get() == ptn)
2210 return true;
2211 }
2212 return false;
2213 }
2214
2215 // Return true if one node points to an other.
2216 bool PointsToNode::meet(PointsToNode* ptn) {
2217 if (this == ptn) {
2218 return true;
2219 } else if (ptn->is_JavaObject()) {
2220 return this->points_to(ptn->as_JavaObject());
2221 } else if (this->is_JavaObject()) {
2222 return ptn->points_to(this->as_JavaObject());
2223 }
2224 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2225 int ptn_count = ptn->edge_count();
2226 for (EdgeIterator i(this); i.has_next(); i.next()) {
2227 PointsToNode* this_e = i.get();
2228 for (int j = 0; j < ptn_count; j++) {
2229 if (this_e == ptn->edge(j))
2230 return true;
2231 }
2232 }
2233 return false;
2234 }
2235
2236 #ifdef ASSERT
2237 // Return true if bases point to this java object.
2238 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2239 for (BaseIterator i(this); i.has_next(); i.next()) {
2240 if (i.get() == jobj)
2241 return true;
2242 }
2243 return false;
2244 }
2245 #endif
2246
2247 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2248 const Type *adr_type = phase->type(adr);
2249 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2250 adr->in(AddPNode::Address)->is_Proj() &&
2251 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2252 // We are computing a raw address for a store captured by an Initialize
2253 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2254 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2255 assert(offs != Type::OffsetBot ||
2256 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2257 "offset must be a constant or it is initialization of array");
2258 return offs;
2259 }
2260 const TypePtr *t_ptr = adr_type->isa_ptr();
2261 assert(t_ptr != NULL, "must be a pointer type");
2262 return t_ptr->offset();
2263 }
2264
2265 Node* ConnectionGraph::get_addp_base(Node *addp) {
2266 assert(addp->is_AddP(), "must be AddP");
2267 //
2268 // AddP cases for Base and Address inputs:
2269 // case #1. Direct object's field reference:
2270 // Allocate
2271 // |
2272 // Proj #5 ( oop result )
2273 // |
2274 // CheckCastPP (cast to instance type)
2275 // | |
2276 // AddP ( base == address )
2277 //
2278 // case #2. Indirect object's field reference:
2279 // Phi
2280 // |
2281 // CastPP (cast to instance type)
2282 // | |
2283 // AddP ( base == address )
2284 //
2285 // case #3. Raw object's field reference for Initialize node:
2286 // Allocate
2287 // |
2288 // Proj #5 ( oop result )
2289 // top |
2290 // \ |
2291 // AddP ( base == top )
2292 //
2293 // case #4. Array's element reference:
2294 // {CheckCastPP | CastPP}
2295 // | | |
2296 // | AddP ( array's element offset )
2297 // | |
2298 // AddP ( array's offset )
2299 //
2300 // case #5. Raw object's field reference for arraycopy stub call:
2301 // The inline_native_clone() case when the arraycopy stub is called
2302 // after the allocation before Initialize and CheckCastPP nodes.
2303 // Allocate
2304 // |
2305 // Proj #5 ( oop result )
2306 // | |
2307 // AddP ( base == address )
2308 //
2309 // case #6. Constant Pool, ThreadLocal, CastX2P or
2310 // Raw object's field reference:
2311 // {ConP, ThreadLocal, CastX2P, raw Load}
2312 // top |
2313 // \ |
2314 // AddP ( base == top )
2315 //
2316 // case #7. Klass's field reference.
2317 // LoadKlass
2318 // | |
2319 // AddP ( base == address )
2320 //
2321 // case #8. narrow Klass's field reference.
2322 // LoadNKlass
2323 // |
2324 // DecodeN
2325 // | |
2326 // AddP ( base == address )
2327 //
2328 Node *base = addp->in(AddPNode::Base);
2329 if (base->uncast()->is_top()) { // The AddP case #3 and #6.
2330 base = addp->in(AddPNode::Address);
2331 while (base->is_AddP()) {
2332 // Case #6 (unsafe access) may have several chained AddP nodes.
2333 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2334 base = base->in(AddPNode::Address);
2335 }
2336 Node* uncast_base = base->uncast();
2337 int opcode = uncast_base->Opcode();
2338 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2339 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2340 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2341 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2342 }
2343 return base;
2344 }
2345
2346 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2347 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2348 Node* addp2 = addp->raw_out(0);
2349 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2350 addp2->in(AddPNode::Base) == n &&
2351 addp2->in(AddPNode::Address) == addp) {
2352 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2353 //
2354 // Find array's offset to push it on worklist first and
2355 // as result process an array's element offset first (pushed second)
2356 // to avoid CastPP for the array's offset.
2357 // Otherwise the inserted CastPP (LocalVar) will point to what
2358 // the AddP (Field) points to. Which would be wrong since
2359 // the algorithm expects the CastPP has the same point as
2360 // as AddP's base CheckCastPP (LocalVar).
2361 //
2362 // ArrayAllocation
2363 // |
2364 // CheckCastPP
2365 // |
2366 // memProj (from ArrayAllocation CheckCastPP)
2367 // | ||
2368 // | || Int (element index)
2369 // | || | ConI (log(element size))
2370 // | || | /
2371 // | || LShift
2372 // | || /
2373 // | AddP (array's element offset)
2374 // | |
2375 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2376 // | / /
2377 // AddP (array's offset)
2378 // |
2379 // Load/Store (memory operation on array's element)
2380 //
2381 return addp2;
2382 }
2383 return NULL;
2384 }
2385
2386 //
2387 // Adjust the type and inputs of an AddP which computes the
2388 // address of a field of an instance
2389 //
2390 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2391 PhaseGVN* igvn = _igvn;
2392 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2393 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2394 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2395 if (t == NULL) {
2396 // We are computing a raw address for a store captured by an Initialize
2397 // compute an appropriate address type (cases #3 and #5).
2398 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2399 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2400 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2401 assert(offs != Type::OffsetBot, "offset must be a constant");
2402 t = base_t->add_offset(offs)->is_oopptr();
2403 }
2404 int inst_id = base_t->instance_id();
2405 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2406 "old type must be non-instance or match new type");
2407
2408 // The type 't' could be subclass of 'base_t'.
2409 // As result t->offset() could be large then base_t's size and it will
2410 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2411 // constructor verifies correctness of the offset.
2412 //
2413 // It could happened on subclass's branch (from the type profiling
2414 // inlining) which was not eliminated during parsing since the exactness
2415 // of the allocation type was not propagated to the subclass type check.
2416 //
2417 // Or the type 't' could be not related to 'base_t' at all.
2418 // It could happened when CHA type is different from MDO type on a dead path
2419 // (for example, from instanceof check) which is not collapsed during parsing.
2420 //
2421 // Do nothing for such AddP node and don't process its users since
2422 // this code branch will go away.
2423 //
2424 if (!t->is_known_instance() &&
2425 !base_t->klass()->is_subtype_of(t->klass())) {
2426 return false; // bail out
2427 }
2428 const TypePtr* tinst = base_t->add_offset(t->offset());
2429 if (tinst->isa_aryptr() && t->isa_aryptr()) {
2430 // In the case of a flattened value type array, each field has its
2431 // own slice so we need to keep track of the field being accessed.
2432 tinst = tinst->is_aryptr()->with_field_offset(t->is_aryptr()->field_offset().get());
2433 }
2434
2435 // Do NOT remove the next line: ensure a new alias index is allocated
2436 // for the instance type. Note: C++ will not remove it since the call
2437 // has side effect.
2438 int alias_idx = _compile->get_alias_index(tinst);
2439 igvn->set_type(addp, tinst);
2440 // record the allocation in the node map
2441 set_map(addp, get_map(base->_idx));
2442 // Set addp's Base and Address to 'base'.
2443 Node *abase = addp->in(AddPNode::Base);
2444 Node *adr = addp->in(AddPNode::Address);
2445 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2446 adr->in(0)->_idx == (uint)inst_id) {
2447 // Skip AddP cases #3 and #5.
2448 } else {
2449 assert(!abase->is_top(), "sanity"); // AddP case #3
2450 if (abase != base) {
2451 igvn->hash_delete(addp);
2452 addp->set_req(AddPNode::Base, base);
2453 if (abase == adr) {
2454 addp->set_req(AddPNode::Address, base);
2455 } else {
2456 // AddP case #4 (adr is array's element offset AddP node)
2457 #ifdef ASSERT
2458 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2459 assert(adr->is_AddP() && atype != NULL &&
2460 atype->instance_id() == inst_id, "array's element offset should be processed first");
2461 #endif
2462 }
2463 igvn->hash_insert(addp);
2464 }
2465 }
2466 // Put on IGVN worklist since at least addp's type was changed above.
2467 record_for_optimizer(addp);
2468 return true;
2469 }
2470
2471 //
2472 // Create a new version of orig_phi if necessary. Returns either the newly
2473 // created phi or an existing phi. Sets create_new to indicate whether a new
2474 // phi was created. Cache the last newly created phi in the node map.
2475 //
2476 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2477 Compile *C = _compile;
2478 PhaseGVN* igvn = _igvn;
2479 new_created = false;
2480 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2481 // nothing to do if orig_phi is bottom memory or matches alias_idx
2482 if (phi_alias_idx == alias_idx) {
2483 return orig_phi;
2484 }
2485 // Have we recently created a Phi for this alias index?
2486 PhiNode *result = get_map_phi(orig_phi->_idx);
2487 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2488 return result;
2489 }
2490 // Previous check may fail when the same wide memory Phi was split into Phis
2491 // for different memory slices. Search all Phis for this region.
2492 if (result != NULL) {
2493 Node* region = orig_phi->in(0);
2494 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2495 Node* phi = region->fast_out(i);
2496 if (phi->is_Phi() &&
2497 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2498 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2499 return phi->as_Phi();
2500 }
2501 }
2502 }
2503 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2504 if (C->do_escape_analysis() == true && !C->failing()) {
2505 // Retry compilation without escape analysis.
2506 // If this is the first failure, the sentinel string will "stick"
2507 // to the Compile object, and the C2Compiler will see it and retry.
2508 C->record_failure(C2Compiler::retry_no_escape_analysis());
2509 }
2510 return NULL;
2511 }
2512 orig_phi_worklist.append_if_missing(orig_phi);
2513 const TypePtr *atype = C->get_adr_type(alias_idx);
2514 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2515 C->copy_node_notes_to(result, orig_phi);
2516 igvn->set_type(result, result->bottom_type());
2517 record_for_optimizer(result);
2518 set_map(orig_phi, result);
2519 new_created = true;
2520 return result;
2521 }
2522
2523 //
2524 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2525 // specified alias index.
2526 //
2527 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2528 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2529 Compile *C = _compile;
2530 PhaseGVN* igvn = _igvn;
2531 bool new_phi_created;
2532 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2533 if (!new_phi_created) {
2534 return result;
2535 }
2536 GrowableArray<PhiNode *> phi_list;
2537 GrowableArray<uint> cur_input;
2538 PhiNode *phi = orig_phi;
2539 uint idx = 1;
2540 bool finished = false;
2541 while(!finished) {
2542 while (idx < phi->req()) {
2543 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2544 if (mem != NULL && mem->is_Phi()) {
2545 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2546 if (new_phi_created) {
2547 // found an phi for which we created a new split, push current one on worklist and begin
2548 // processing new one
2549 phi_list.push(phi);
2550 cur_input.push(idx);
2551 phi = mem->as_Phi();
2552 result = newphi;
2553 idx = 1;
2554 continue;
2555 } else {
2556 mem = newphi;
2557 }
2558 }
2559 if (C->failing()) {
2560 return NULL;
2561 }
2562 result->set_req(idx++, mem);
2563 }
2564 #ifdef ASSERT
2565 // verify that the new Phi has an input for each input of the original
2566 assert( phi->req() == result->req(), "must have same number of inputs.");
2567 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2568 #endif
2569 // Check if all new phi's inputs have specified alias index.
2570 // Otherwise use old phi.
2571 for (uint i = 1; i < phi->req(); i++) {
2572 Node* in = result->in(i);
2573 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2574 }
2575 // we have finished processing a Phi, see if there are any more to do
2576 finished = (phi_list.length() == 0 );
2577 if (!finished) {
2578 phi = phi_list.pop();
2579 idx = cur_input.pop();
2580 PhiNode *prev_result = get_map_phi(phi->_idx);
2581 prev_result->set_req(idx++, result);
2582 result = prev_result;
2583 }
2584 }
2585 return result;
2586 }
2587
2588 //
2589 // The next methods are derived from methods in MemNode.
2590 //
2591 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2592 Node *mem = mmem;
2593 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2594 // means an array I have not precisely typed yet. Do not do any
2595 // alias stuff with it any time soon.
2596 if (toop->base() != Type::AnyPtr &&
2597 !(toop->klass() != NULL &&
2598 toop->klass()->is_java_lang_Object() &&
2599 toop->offset() == Type::OffsetBot)) {
2600 mem = mmem->memory_at(alias_idx);
2601 // Update input if it is progress over what we have now
2602 }
2603 return mem;
2604 }
2605
2606 //
2607 // Move memory users to their memory slices.
2608 //
2609 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2610 Compile* C = _compile;
2611 PhaseGVN* igvn = _igvn;
2612 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2613 assert(tp != NULL, "ptr type");
2614 int alias_idx = C->get_alias_index(tp);
2615 int general_idx = C->get_general_index(alias_idx);
2616
2617 // Move users first
2618 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2619 Node* use = n->fast_out(i);
2620 if (use->is_MergeMem()) {
2621 MergeMemNode* mmem = use->as_MergeMem();
2622 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2623 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2624 continue; // Nothing to do
2625 }
2626 // Replace previous general reference to mem node.
2627 uint orig_uniq = C->unique();
2628 Node* m = find_inst_mem(n, general_idx, orig_phis);
2629 assert(orig_uniq == C->unique(), "no new nodes");
2630 mmem->set_memory_at(general_idx, m);
2631 --imax;
2632 --i;
2633 } else if (use->is_MemBar()) {
2634 assert(!use->is_Initialize(), "initializing stores should not be moved");
2635 if (use->req() > MemBarNode::Precedent &&
2636 use->in(MemBarNode::Precedent) == n) {
2637 // Don't move related membars.
2638 record_for_optimizer(use);
2639 continue;
2640 }
2641 tp = use->as_MemBar()->adr_type()->isa_ptr();
2642 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
2643 alias_idx == general_idx) {
2644 continue; // Nothing to do
2645 }
2646 // Move to general memory slice.
2647 uint orig_uniq = C->unique();
2648 Node* m = find_inst_mem(n, general_idx, orig_phis);
2649 assert(orig_uniq == C->unique(), "no new nodes");
2650 igvn->hash_delete(use);
2651 imax -= use->replace_edge(n, m);
2652 igvn->hash_insert(use);
2653 record_for_optimizer(use);
2654 --i;
2655 #ifdef ASSERT
2656 } else if (use->is_Mem()) {
2657 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2658 // Don't move related cardmark.
2659 continue;
2660 }
2661 // Memory nodes should have new memory input.
2662 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2663 assert(tp != NULL, "ptr type");
2664 int idx = C->get_alias_index(tp);
2665 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2666 "Following memory nodes should have new memory input or be on the same memory slice");
2667 } else if (use->is_Phi()) {
2668 // Phi nodes should be split and moved already.
2669 tp = use->as_Phi()->adr_type()->isa_ptr();
2670 assert(tp != NULL, "ptr type");
2671 int idx = C->get_alias_index(tp);
2672 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2673 } else {
2674 use->dump();
2675 assert(false, "should not be here");
2676 #endif
2677 }
2678 }
2679 }
2680
2681 //
2682 // Search memory chain of "mem" to find a MemNode whose address
2683 // is the specified alias index.
2684 //
2685 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2686 if (orig_mem == NULL)
2687 return orig_mem;
2688 Compile* C = _compile;
2689 PhaseGVN* igvn = _igvn;
2690 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2691 bool is_instance = (toop != NULL) && toop->is_known_instance();
2692 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
2693 Node *prev = NULL;
2694 Node *result = orig_mem;
2695 while (prev != result) {
2696 prev = result;
2697 if (result == start_mem)
2698 break; // hit one of our sentinels
2699 if (result->is_Mem()) {
2700 const Type *at = igvn->type(result->in(MemNode::Address));
2701 if (at == Type::TOP)
2702 break; // Dead
2703 assert (at->isa_ptr() != NULL, "pointer type required.");
2704 int idx = C->get_alias_index(at->is_ptr());
2705 if (idx == alias_idx)
2706 break; // Found
2707 if (!is_instance && (at->isa_oopptr() == NULL ||
2708 !at->is_oopptr()->is_known_instance())) {
2709 break; // Do not skip store to general memory slice.
2710 }
2711 result = result->in(MemNode::Memory);
2712 }
2713 if (!is_instance)
2714 continue; // don't search further for non-instance types
2715 // skip over a call which does not affect this memory slice
2716 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2717 Node *proj_in = result->in(0);
2718 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2719 break; // hit one of our sentinels
2720 } else if (proj_in->is_Call()) {
2721 // ArrayCopy node processed here as well
2722 CallNode *call = proj_in->as_Call();
2723 if (!call->may_modify(toop, igvn)) {
2724 result = call->in(TypeFunc::Memory);
2725 }
2726 } else if (proj_in->is_Initialize()) {
2727 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2728 // Stop if this is the initialization for the object instance which
2729 // which contains this memory slice, otherwise skip over it.
2730 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2731 result = proj_in->in(TypeFunc::Memory);
2732 }
2733 } else if (proj_in->is_MemBar()) {
2734 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2735 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2736 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2737 // clone
2738 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2739 if (ac->may_modify(toop, igvn)) {
2740 break;
2741 }
2742 }
2743 result = proj_in->in(TypeFunc::Memory);
2744 }
2745 } else if (result->is_MergeMem()) {
2746 MergeMemNode *mmem = result->as_MergeMem();
2747 result = step_through_mergemem(mmem, alias_idx, toop);
2748 if (result == mmem->base_memory()) {
2749 // Didn't find instance memory, search through general slice recursively.
2750 result = mmem->memory_at(C->get_general_index(alias_idx));
2751 result = find_inst_mem(result, alias_idx, orig_phis);
2752 if (C->failing()) {
2753 return NULL;
2754 }
2755 mmem->set_memory_at(alias_idx, result);
2756 }
2757 } else if (result->is_Phi() &&
2758 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2759 Node *un = result->as_Phi()->unique_input(igvn);
2760 if (un != NULL) {
2761 orig_phis.append_if_missing(result->as_Phi());
2762 result = un;
2763 } else {
2764 break;
2765 }
2766 } else if (result->is_ClearArray()) {
2767 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2768 // Can not bypass initialization of the instance
2769 // we are looking for.
2770 break;
2771 }
2772 // Otherwise skip it (the call updated 'result' value).
2773 } else if (result->Opcode() == Op_SCMemProj) {
2774 Node* mem = result->in(0);
2775 Node* adr = NULL;
2776 if (mem->is_LoadStore()) {
2777 adr = mem->in(MemNode::Address);
2778 } else {
2779 assert(mem->Opcode() == Op_EncodeISOArray ||
2780 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2781 adr = mem->in(3); // Memory edge corresponds to destination array
2782 }
2783 const Type *at = igvn->type(adr);
2784 if (at != Type::TOP) {
2785 assert(at->isa_ptr() != NULL, "pointer type required.");
2786 int idx = C->get_alias_index(at->is_ptr());
2787 if (idx == alias_idx) {
2788 // Assert in debug mode
2789 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2790 break; // In product mode return SCMemProj node
2791 }
2792 }
2793 result = mem->in(MemNode::Memory);
2794 } else if (result->Opcode() == Op_StrInflatedCopy) {
2795 Node* adr = result->in(3); // Memory edge corresponds to destination array
2796 const Type *at = igvn->type(adr);
2797 if (at != Type::TOP) {
2798 assert(at->isa_ptr() != NULL, "pointer type required.");
2799 int idx = C->get_alias_index(at->is_ptr());
2800 if (idx == alias_idx) {
2801 // Assert in debug mode
2802 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2803 break; // In product mode return SCMemProj node
2804 }
2805 }
2806 result = result->in(MemNode::Memory);
2807 }
2808 }
2809 if (result->is_Phi()) {
2810 PhiNode *mphi = result->as_Phi();
2811 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2812 const TypePtr *t = mphi->adr_type();
2813 if (!is_instance) {
2814 // Push all non-instance Phis on the orig_phis worklist to update inputs
2815 // during Phase 4 if needed.
2816 orig_phis.append_if_missing(mphi);
2817 } else if (C->get_alias_index(t) != alias_idx) {
2818 // Create a new Phi with the specified alias index type.
2819 result = split_memory_phi(mphi, alias_idx, orig_phis);
2820 }
2821 }
2822 // the result is either MemNode, PhiNode, InitializeNode.
2823 return result;
2824 }
2825
2826 //
2827 // Convert the types of unescaped object to instance types where possible,
2828 // propagate the new type information through the graph, and update memory
2829 // edges and MergeMem inputs to reflect the new type.
2830 //
2831 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2832 // The processing is done in 4 phases:
2833 //
2834 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2835 // types for the CheckCastPP for allocations where possible.
2836 // Propagate the new types through users as follows:
2837 // casts and Phi: push users on alloc_worklist
2838 // AddP: cast Base and Address inputs to the instance type
2839 // push any AddP users on alloc_worklist and push any memnode
2840 // users onto memnode_worklist.
2841 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2842 // search the Memory chain for a store with the appropriate type
2843 // address type. If a Phi is found, create a new version with
2844 // the appropriate memory slices from each of the Phi inputs.
2845 // For stores, process the users as follows:
2846 // MemNode: push on memnode_worklist
2847 // MergeMem: push on mergemem_worklist
2848 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2849 // moving the first node encountered of each instance type to the
2850 // the input corresponding to its alias index.
2851 // appropriate memory slice.
2852 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2853 //
2854 // In the following example, the CheckCastPP nodes are the cast of allocation
2855 // results and the allocation of node 29 is unescaped and eligible to be an
2856 // instance type.
2857 //
2858 // We start with:
2859 //
2860 // 7 Parm #memory
2861 // 10 ConI "12"
2862 // 19 CheckCastPP "Foo"
2863 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2864 // 29 CheckCastPP "Foo"
2865 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2866 //
2867 // 40 StoreP 25 7 20 ... alias_index=4
2868 // 50 StoreP 35 40 30 ... alias_index=4
2869 // 60 StoreP 45 50 20 ... alias_index=4
2870 // 70 LoadP _ 60 30 ... alias_index=4
2871 // 80 Phi 75 50 60 Memory alias_index=4
2872 // 90 LoadP _ 80 30 ... alias_index=4
2873 // 100 LoadP _ 80 20 ... alias_index=4
2874 //
2875 //
2876 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2877 // and creating a new alias index for node 30. This gives:
2878 //
2879 // 7 Parm #memory
2880 // 10 ConI "12"
2881 // 19 CheckCastPP "Foo"
2882 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2883 // 29 CheckCastPP "Foo" iid=24
2884 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2885 //
2886 // 40 StoreP 25 7 20 ... alias_index=4
2887 // 50 StoreP 35 40 30 ... alias_index=6
2888 // 60 StoreP 45 50 20 ... alias_index=4
2889 // 70 LoadP _ 60 30 ... alias_index=6
2890 // 80 Phi 75 50 60 Memory alias_index=4
2891 // 90 LoadP _ 80 30 ... alias_index=6
2892 // 100 LoadP _ 80 20 ... alias_index=4
2893 //
2894 // In phase 2, new memory inputs are computed for the loads and stores,
2895 // And a new version of the phi is created. In phase 4, the inputs to
2896 // node 80 are updated and then the memory nodes are updated with the
2897 // values computed in phase 2. This results in:
2898 //
2899 // 7 Parm #memory
2900 // 10 ConI "12"
2901 // 19 CheckCastPP "Foo"
2902 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2903 // 29 CheckCastPP "Foo" iid=24
2904 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2905 //
2906 // 40 StoreP 25 7 20 ... alias_index=4
2907 // 50 StoreP 35 7 30 ... alias_index=6
2908 // 60 StoreP 45 40 20 ... alias_index=4
2909 // 70 LoadP _ 50 30 ... alias_index=6
2910 // 80 Phi 75 40 60 Memory alias_index=4
2911 // 120 Phi 75 50 50 Memory alias_index=6
2912 // 90 LoadP _ 120 30 ... alias_index=6
2913 // 100 LoadP _ 80 20 ... alias_index=4
2914 //
2915 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2916 GrowableArray<Node *> memnode_worklist;
2917 GrowableArray<PhiNode *> orig_phis;
2918 PhaseIterGVN *igvn = _igvn;
2919 uint new_index_start = (uint) _compile->num_alias_types();
2920 Arena* arena = Thread::current()->resource_area();
2921 VectorSet visited(arena);
2922 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2923 uint unique_old = _compile->unique();
2924
2925 // Phase 1: Process possible allocations from alloc_worklist.
2926 // Create instance types for the CheckCastPP for allocations where possible.
2927 //
2928 // (Note: don't forget to change the order of the second AddP node on
2929 // the alloc_worklist if the order of the worklist processing is changed,
2930 // see the comment in find_second_addp().)
2931 //
2932 while (alloc_worklist.length() != 0) {
2933 Node *n = alloc_worklist.pop();
2934 uint ni = n->_idx;
2935 if (n->is_Call()) {
2936 CallNode *alloc = n->as_Call();
2937 // copy escape information to call node
2938 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2939 PointsToNode::EscapeState es = ptn->escape_state();
2940 // We have an allocation or call which returns a Java object,
2941 // see if it is unescaped.
2942 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2943 continue;
2944 // Find CheckCastPP for the allocate or for the return value of a call
2945 n = alloc->result_cast();
2946 if (n == NULL) { // No uses except Initialize node
2947 if (alloc->is_Allocate()) {
2948 // Set the scalar_replaceable flag for allocation
2949 // so it could be eliminated if it has no uses.
2950 alloc->as_Allocate()->_is_scalar_replaceable = true;
2951 }
2952 if (alloc->is_CallStaticJava()) {
2953 // Set the scalar_replaceable flag for boxing method
2954 // so it could be eliminated if it has no uses.
2955 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2956 }
2957 continue;
2958 }
2959 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2960 assert(!alloc->is_Allocate(), "allocation should have unique type");
2961 continue;
2962 }
2963
2964 // The inline code for Object.clone() casts the allocation result to
2965 // java.lang.Object and then to the actual type of the allocated
2966 // object. Detect this case and use the second cast.
2967 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2968 // the allocation result is cast to java.lang.Object and then
2969 // to the actual Array type.
2970 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2971 && (alloc->is_AllocateArray() ||
2972 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2973 Node *cast2 = NULL;
2974 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2975 Node *use = n->fast_out(i);
2976 if (use->is_CheckCastPP()) {
2977 cast2 = use;
2978 break;
2979 }
2980 }
2981 if (cast2 != NULL) {
2982 n = cast2;
2983 } else {
2984 // Non-scalar replaceable if the allocation type is unknown statically
2985 // (reflection allocation), the object can't be restored during
2986 // deoptimization without precise type.
2987 continue;
2988 }
2989 }
2990
2991 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2992 if (t == NULL)
2993 continue; // not a TypeOopPtr
2994 if (!t->klass_is_exact())
2995 continue; // not an unique type
2996
2997 if (alloc->is_Allocate()) {
2998 // Set the scalar_replaceable flag for allocation
2999 // so it could be eliminated.
3000 alloc->as_Allocate()->_is_scalar_replaceable = true;
3001 }
3002 if (alloc->is_CallStaticJava()) {
3003 // Set the scalar_replaceable flag for boxing method
3004 // so it could be eliminated.
3005 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3006 }
3007 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3008 // in order for an object to be scalar-replaceable, it must be:
3009 // - a direct allocation (not a call returning an object)
3010 // - non-escaping
3011 // - eligible to be a unique type
3012 // - not determined to be ineligible by escape analysis
3013 set_map(alloc, n);
3014 set_map(n, alloc);
3015 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3016 igvn->hash_delete(n);
3017 igvn->set_type(n, tinst);
3018 n->raise_bottom_type(tinst);
3019 igvn->hash_insert(n);
3020 record_for_optimizer(n);
3021 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr() || t->isa_valuetypeptr())) {
3022
3023 // First, put on the worklist all Field edges from Connection Graph
3024 // which is more accurate than putting immediate users from Ideal Graph.
3025 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3026 PointsToNode* tgt = e.get();
3027 if (tgt->is_Arraycopy()) {
3028 continue;
3029 }
3030 Node* use = tgt->ideal_node();
3031 assert(tgt->is_Field() && use->is_AddP(),
3032 "only AddP nodes are Field edges in CG");
3033 if (use->outcnt() > 0) { // Don't process dead nodes
3034 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3035 if (addp2 != NULL) {
3036 assert(alloc->is_AllocateArray(),"array allocation was expected");
3037 alloc_worklist.append_if_missing(addp2);
3038 }
3039 alloc_worklist.append_if_missing(use);
3040 }
3041 }
3042
3043 // An allocation may have an Initialize which has raw stores. Scan
3044 // the users of the raw allocation result and push AddP users
3045 // on alloc_worklist.
3046 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
3047 assert (raw_result != NULL, "must have an allocation result");
3048 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3049 Node *use = raw_result->fast_out(i);
3050 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3051 Node* addp2 = find_second_addp(use, raw_result);
3052 if (addp2 != NULL) {
3053 assert(alloc->is_AllocateArray(),"array allocation was expected");
3054 alloc_worklist.append_if_missing(addp2);
3055 }
3056 alloc_worklist.append_if_missing(use);
3057 } else if (use->is_MemBar()) {
3058 memnode_worklist.append_if_missing(use);
3059 }
3060 }
3061 }
3062 } else if (n->is_AddP()) {
3063 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3064 if (jobj == NULL || jobj == phantom_obj) {
3065 #ifdef ASSERT
3066 ptnode_adr(get_addp_base(n)->_idx)->dump();
3067 ptnode_adr(n->_idx)->dump();
3068 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3069 #endif
3070 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3071 return;
3072 }
3073 Node *base = get_map(jobj->idx()); // CheckCastPP node
3074 if (!split_AddP(n, base)) continue; // wrong type from dead path
3075 } else if (n->is_Phi() ||
3076 n->is_CheckCastPP() ||
3077 n->is_EncodeP() ||
3078 n->is_DecodeN() ||
3079 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3080 if (visited.test_set(n->_idx)) {
3081 assert(n->is_Phi(), "loops only through Phi's");
3082 continue; // already processed
3083 }
3084 JavaObjectNode* jobj = unique_java_object(n);
3085 if (jobj == NULL || jobj == phantom_obj) {
3086 #ifdef ASSERT
3087 ptnode_adr(n->_idx)->dump();
3088 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3089 #endif
3090 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3091 return;
3092 } else {
3093 Node *val = get_map(jobj->idx()); // CheckCastPP node
3094 TypeNode *tn = n->as_Type();
3095 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3096 assert(tinst != NULL && tinst->is_known_instance() &&
3097 tinst->instance_id() == jobj->idx() , "instance type expected.");
3098
3099 const Type *tn_type = igvn->type(tn);
3100 const TypeOopPtr *tn_t;
3101 if (tn_type->isa_narrowoop()) {
3102 tn_t = tn_type->make_ptr()->isa_oopptr();
3103 } else {
3104 tn_t = tn_type->isa_oopptr();
3105 }
3106 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3107 if (tn_type->isa_narrowoop()) {
3108 tn_type = tinst->make_narrowoop();
3109 } else {
3110 tn_type = tinst;
3111 }
3112 igvn->hash_delete(tn);
3113 igvn->set_type(tn, tn_type);
3114 tn->set_type(tn_type);
3115 igvn->hash_insert(tn);
3116 record_for_optimizer(n);
3117 } else {
3118 assert(tn_type == TypePtr::NULL_PTR ||
3119 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3120 "unexpected type");
3121 continue; // Skip dead path with different type
3122 }
3123 }
3124 } else {
3125 debug_only(n->dump();)
3126 assert(false, "EA: unexpected node");
3127 continue;
3128 }
3129 // push allocation's users on appropriate worklist
3130 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3131 Node *use = n->fast_out(i);
3132 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3133 // Load/store to instance's field
3134 memnode_worklist.append_if_missing(use);
3135 } else if (use->is_MemBar()) {
3136 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3137 memnode_worklist.append_if_missing(use);
3138 }
3139 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3140 Node* addp2 = find_second_addp(use, n);
3141 if (addp2 != NULL) {
3142 alloc_worklist.append_if_missing(addp2);
3143 }
3144 alloc_worklist.append_if_missing(use);
3145 } else if (use->is_Phi() ||
3146 use->is_CheckCastPP() ||
3147 use->is_EncodeNarrowPtr() ||
3148 use->is_DecodeNarrowPtr() ||
3149 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3150 alloc_worklist.append_if_missing(use);
3151 #ifdef ASSERT
3152 } else if (use->is_Mem()) {
3153 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3154 } else if (use->is_MergeMem()) {
3155 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3156 } else if (use->is_SafePoint()) {
3157 // Look for MergeMem nodes for calls which reference unique allocation
3158 // (through CheckCastPP nodes) even for debug info.
3159 Node* m = use->in(TypeFunc::Memory);
3160 if (m->is_MergeMem()) {
3161 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3162 }
3163 } else if (use->Opcode() == Op_EncodeISOArray) {
3164 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3165 // EncodeISOArray overwrites destination array
3166 memnode_worklist.append_if_missing(use);
3167 }
3168 } else if (use->Opcode() == Op_Return) {
3169 Node* klass = use->in(TypeFunc::Parms);
3170 const TypeKlassPtr* tkls = igvn->type(klass)->isa_klassptr();
3171 ciValueKlass* vk = tkls->klass()->as_value_klass();
3172 assert(_compile->tf()->returns_value_type_as_fields(), "must return a value type");
3173 assert(vk->contains_oops(), "returned value type must contain a reference field");
3174 } else {
3175 uint op = use->Opcode();
3176 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3177 (use->in(MemNode::Memory) == n)) {
3178 // They overwrite memory edge corresponding to destination array,
3179 memnode_worklist.append_if_missing(use);
3180 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3181 op == Op_CastP2X || op == Op_StoreCM ||
3182 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3183 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3184 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3185 op == Op_ValueType)) {
3186 n->dump();
3187 use->dump();
3188 assert(false, "EA: missing allocation reference path");
3189 }
3190 #endif
3191 }
3192 }
3193
3194 }
3195
3196 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3197 // type, record it in the ArrayCopy node so we know what memory this
3198 // node uses/modified.
3199 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3200 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3201 Node* dest = ac->in(ArrayCopyNode::Dest);
3202 if (dest->is_AddP()) {
3203 dest = get_addp_base(dest);
3204 }
3205 JavaObjectNode* jobj = unique_java_object(dest);
3206 if (jobj != NULL) {
3207 Node *base = get_map(jobj->idx());
3208 if (base != NULL) {
3209 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3210 ac->_dest_type = base_t;
3211 }
3212 }
3213 Node* src = ac->in(ArrayCopyNode::Src);
3214 if (src->is_AddP()) {
3215 src = get_addp_base(src);
3216 }
3217 jobj = unique_java_object(src);
3218 if (jobj != NULL) {
3219 Node* base = get_map(jobj->idx());
3220 if (base != NULL) {
3221 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3222 ac->_src_type = base_t;
3223 }
3224 }
3225 }
3226
3227 // New alias types were created in split_AddP().
3228 uint new_index_end = (uint) _compile->num_alias_types();
3229 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3230
3231 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3232 // compute new values for Memory inputs (the Memory inputs are not
3233 // actually updated until phase 4.)
3234 if (memnode_worklist.length() == 0)
3235 return; // nothing to do
3236 while (memnode_worklist.length() != 0) {
3237 Node *n = memnode_worklist.pop();
3238 if (visited.test_set(n->_idx))
3239 continue;
3240 if (n->is_Phi() || n->is_ClearArray()) {
3241 // we don't need to do anything, but the users must be pushed
3242 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3243 // we don't need to do anything, but the users must be pushed
3244 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
3245 if (n == NULL)
3246 continue;
3247 } else if (n->Opcode() == Op_StrCompressedCopy ||
3248 n->Opcode() == Op_EncodeISOArray) {
3249 // get the memory projection
3250 n = n->find_out_with(Op_SCMemProj);
3251 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3252 } else {
3253 assert(n->is_Mem(), "memory node required.");
3254 Node *addr = n->in(MemNode::Address);
3255 const Type *addr_t = igvn->type(addr);
3256 if (addr_t == Type::TOP)
3257 continue;
3258 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3259 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3260 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3261 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3262 if (_compile->failing()) {
3263 return;
3264 }
3265 if (mem != n->in(MemNode::Memory)) {
3266 // We delay the memory edge update since we need old one in
3267 // MergeMem code below when instances memory slices are separated.
3268 set_map(n, mem);
3269 }
3270 if (n->is_Load()) {
3271 continue; // don't push users
3272 } else if (n->is_LoadStore()) {
3273 // get the memory projection
3274 n = n->find_out_with(Op_SCMemProj);
3275 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
3276 }
3277 }
3278 // push user on appropriate worklist
3279 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3280 Node *use = n->fast_out(i);
3281 if (use->is_Phi() || use->is_ClearArray()) {
3282 memnode_worklist.append_if_missing(use);
3283 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3284 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3285 continue;
3286 memnode_worklist.append_if_missing(use);
3287 } else if (use->is_MemBar()) {
3288 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3289 memnode_worklist.append_if_missing(use);
3290 }
3291 #ifdef ASSERT
3292 } else if(use->is_Mem()) {
3293 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3294 } else if (use->is_MergeMem()) {
3295 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3296 } else if (use->Opcode() == Op_EncodeISOArray) {
3297 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3298 // EncodeISOArray overwrites destination array
3299 memnode_worklist.append_if_missing(use);
3300 }
3301 } else {
3302 uint op = use->Opcode();
3303 if ((use->in(MemNode::Memory) == n) &&
3304 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3305 // They overwrite memory edge corresponding to destination array,
3306 memnode_worklist.append_if_missing(use);
3307 } else if (!(op == Op_StoreCM ||
3308 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
3309 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
3310 op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3311 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3312 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar)) {
3313 n->dump();
3314 use->dump();
3315 assert(false, "EA: missing memory path");
3316 }
3317 #endif
3318 }
3319 }
3320 }
3321
3322 // Phase 3: Process MergeMem nodes from mergemem_worklist.
3323 // Walk each memory slice moving the first node encountered of each
3324 // instance type to the input corresponding to its alias index.
3325 uint length = _mergemem_worklist.length();
3326 for( uint next = 0; next < length; ++next ) {
3327 MergeMemNode* nmm = _mergemem_worklist.at(next);
3328 assert(!visited.test_set(nmm->_idx), "should not be visited before");
3329 // Note: we don't want to use MergeMemStream here because we only want to
3330 // scan inputs which exist at the start, not ones we add during processing.
3331 // Note 2: MergeMem may already contains instance memory slices added
3332 // during find_inst_mem() call when memory nodes were processed above.
3333 igvn->hash_delete(nmm);
3334 uint nslices = MIN2(nmm->req(), new_index_start);
3335 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
3336 Node* mem = nmm->in(i);
3337 Node* cur = NULL;
3338 if (mem == NULL || mem->is_top())
3339 continue;
3340 // First, update mergemem by moving memory nodes to corresponding slices
3341 // if their type became more precise since this mergemem was created.
3342 while (mem->is_Mem()) {
3343 const Type *at = igvn->type(mem->in(MemNode::Address));
3344 if (at != Type::TOP) {
3345 assert (at->isa_ptr() != NULL, "pointer type required.");
3346 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
3347 if (idx == i) {
3348 if (cur == NULL)
3349 cur = mem;
3350 } else {
3351 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
3352 nmm->set_memory_at(idx, mem);
3353 }
3354 }
3355 }
3356 mem = mem->in(MemNode::Memory);
3357 }
3358 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
3359 // Find any instance of the current type if we haven't encountered
3360 // already a memory slice of the instance along the memory chain.
3361 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3362 if((uint)_compile->get_general_index(ni) == i) {
3363 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
3364 if (nmm->is_empty_memory(m)) {
3365 Node* result = find_inst_mem(mem, ni, orig_phis);
3366 if (_compile->failing()) {
3367 return;
3368 }
3369 nmm->set_memory_at(ni, result);
3370 }
3371 }
3372 }
3373 }
3374 // Find the rest of instances values
3375 for (uint ni = new_index_start; ni < new_index_end; ni++) {
3376 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
3377 Node* result = step_through_mergemem(nmm, ni, tinst);
3378 if (result == nmm->base_memory()) {
3379 // Didn't find instance memory, search through general slice recursively.
3380 result = nmm->memory_at(_compile->get_general_index(ni));
3381 result = find_inst_mem(result, ni, orig_phis);
3382 if (_compile->failing()) {
3383 return;
3384 }
3385 nmm->set_memory_at(ni, result);
3386 }
3387 }
3388 igvn->hash_insert(nmm);
3389 record_for_optimizer(nmm);
3390 }
3391
3392 // Phase 4: Update the inputs of non-instance memory Phis and
3393 // the Memory input of memnodes
3394 // First update the inputs of any non-instance Phi's from
3395 // which we split out an instance Phi. Note we don't have
3396 // to recursively process Phi's encountered on the input memory
3397 // chains as is done in split_memory_phi() since they will
3398 // also be processed here.
3399 for (int j = 0; j < orig_phis.length(); j++) {
3400 PhiNode *phi = orig_phis.at(j);
3401 int alias_idx = _compile->get_alias_index(phi->adr_type());
3402 igvn->hash_delete(phi);
3403 for (uint i = 1; i < phi->req(); i++) {
3404 Node *mem = phi->in(i);
3405 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis);
3406 if (_compile->failing()) {
3407 return;
3408 }
3409 if (mem != new_mem) {
3410 phi->set_req(i, new_mem);
3411 }
3412 }
3413 igvn->hash_insert(phi);
3414 record_for_optimizer(phi);
3415 }
3416
3417 // Update the memory inputs of MemNodes with the value we computed
3418 // in Phase 2 and move stores memory users to corresponding memory slices.
3419 // Disable memory split verification code until the fix for 6984348.
3420 // Currently it produces false negative results since it does not cover all cases.
3421 #if 0 // ifdef ASSERT
3422 visited.Reset();
3423 Node_Stack old_mems(arena, _compile->unique() >> 2);
3424 #endif
3425 for (uint i = 0; i < ideal_nodes.size(); i++) {
3426 Node* n = ideal_nodes.at(i);
3427 Node* nmem = get_map(n->_idx);
3428 assert(nmem != NULL, "sanity");
3429 if (n->is_Mem()) {
3430 #if 0 // ifdef ASSERT
3431 Node* old_mem = n->in(MemNode::Memory);
3432 if (!visited.test_set(old_mem->_idx)) {
3433 old_mems.push(old_mem, old_mem->outcnt());
3434 }
3435 #endif
3436 assert(n->in(MemNode::Memory) != nmem, "sanity");
3437 if (!n->is_Load()) {
3438 // Move memory users of a store first.
3439 move_inst_mem(n, orig_phis);
3440 }
3441 // Now update memory input
3442 igvn->hash_delete(n);
3443 n->set_req(MemNode::Memory, nmem);
3444 igvn->hash_insert(n);
3445 record_for_optimizer(n);
3446 } else {
3447 assert(n->is_Allocate() || n->is_CheckCastPP() ||
3448 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
3449 }
3450 }
3451 #if 0 // ifdef ASSERT
3452 // Verify that memory was split correctly
3453 while (old_mems.is_nonempty()) {
3454 Node* old_mem = old_mems.node();
3455 uint old_cnt = old_mems.index();
3456 old_mems.pop();
3457 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
3458 }
3459 #endif
3460 }
3461
3462 #ifndef PRODUCT
3463 static const char *node_type_names[] = {
3464 "UnknownType",
3465 "JavaObject",
3466 "LocalVar",
3467 "Field",
3468 "Arraycopy"
3469 };
3470
3471 static const char *esc_names[] = {
3472 "UnknownEscape",
3473 "NoEscape",
3474 "ArgEscape",
3475 "GlobalEscape"
3476 };
3477
3478 void PointsToNode::dump(bool print_state) const {
3479 NodeType nt = node_type();
3480 tty->print("%s ", node_type_names[(int) nt]);
3481 if (print_state) {
3482 EscapeState es = escape_state();
3483 EscapeState fields_es = fields_escape_state();
3484 tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3485 if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3486 tty->print("NSR ");
3487 }
3488 if (is_Field()) {
3489 FieldNode* f = (FieldNode*)this;
3490 if (f->is_oop())
3491 tty->print("oop ");
3492 if (f->offset() > 0)
3493 tty->print("+%d ", f->offset());
3494 tty->print("(");
3495 for (BaseIterator i(f); i.has_next(); i.next()) {
3496 PointsToNode* b = i.get();
3497 tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3498 }
3499 tty->print(" )");
3500 }
3501 tty->print("[");
3502 for (EdgeIterator i(this); i.has_next(); i.next()) {
3503 PointsToNode* e = i.get();
3504 tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3505 }
3506 tty->print(" [");
3507 for (UseIterator i(this); i.has_next(); i.next()) {
3508 PointsToNode* u = i.get();
3509 bool is_base = false;
3510 if (PointsToNode::is_base_use(u)) {
3511 is_base = true;
3512 u = PointsToNode::get_use_node(u)->as_Field();
3513 }
3514 tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3515 }
3516 tty->print(" ]] ");
3517 if (_node == NULL)
3518 tty->print_cr("<null>");
3519 else
3520 _node->dump();
3521 }
3522
3523 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3524 bool first = true;
3525 int ptnodes_length = ptnodes_worklist.length();
3526 for (int i = 0; i < ptnodes_length; i++) {
3527 PointsToNode *ptn = ptnodes_worklist.at(i);
3528 if (ptn == NULL || !ptn->is_JavaObject())
3529 continue;
3530 PointsToNode::EscapeState es = ptn->escape_state();
3531 if ((es != PointsToNode::NoEscape) && !Verbose) {
3532 continue;
3533 }
3534 Node* n = ptn->ideal_node();
3535 if (n->is_Allocate() || (n->is_CallStaticJava() &&
3536 n->as_CallStaticJava()->is_boxing_method())) {
3537 if (first) {
3538 tty->cr();
3539 tty->print("======== Connection graph for ");
3540 _compile->method()->print_short_name();
3541 tty->cr();
3542 first = false;
3543 }
3544 ptn->dump();
3545 // Print all locals and fields which reference this allocation
3546 for (UseIterator j(ptn); j.has_next(); j.next()) {
3547 PointsToNode* use = j.get();
3548 if (use->is_LocalVar()) {
3549 use->dump(Verbose);
3550 } else if (Verbose) {
3551 use->dump();
3552 }
3553 }
3554 tty->cr();
3555 }
3556 }
3557 }
3558 #endif