1 /*
2 * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/c2/barrierSetC2.hpp"
30 #include "libadt/vectset.hpp"
31 #include "memory/allocation.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "opto/c2compiler.hpp"
34 #include "opto/arraycopynode.hpp"
35 #include "opto/callnode.hpp"
36 #include "opto/cfgnode.hpp"
37 #include "opto/compile.hpp"
38 #include "opto/escape.hpp"
39 #include "opto/phaseX.hpp"
40 #include "opto/movenode.hpp"
41 #include "opto/rootnode.hpp"
42 #include "utilities/macros.hpp"
43
44 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
45 _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),
46 _in_worklist(C->comp_arena()),
47 _next_pidx(0),
48 _collecting(true),
49 _verify(false),
50 _compile(C),
51 _igvn(igvn),
52 _node_map(C->comp_arena()) {
53 // Add unknown java object.
54 add_java_object(C->top(), PointsToNode::GlobalEscape);
55 phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
56 // Add ConP(#NULL) and ConN(#NULL) nodes.
57 Node* oop_null = igvn->zerocon(T_OBJECT);
58 assert(oop_null->_idx < nodes_size(), "should be created already");
59 add_java_object(oop_null, PointsToNode::NoEscape);
60 null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
61 if (UseCompressedOops) {
62 Node* noop_null = igvn->zerocon(T_NARROWOOP);
63 assert(noop_null->_idx < nodes_size(), "should be created already");
64 map_ideal_node(noop_null, null_obj);
65 }
66 _pcmp_neq = NULL; // Should be initialized
67 _pcmp_eq = NULL;
68 }
69
70 bool ConnectionGraph::has_candidates(Compile *C) {
71 // EA brings benefits only when the code has allocations and/or locks which
72 // are represented by ideal Macro nodes.
73 int cnt = C->macro_count();
74 for (int i = 0; i < cnt; i++) {
75 Node *n = C->macro_node(i);
76 if (n->is_Allocate())
77 return true;
78 if (n->is_Lock()) {
79 Node* obj = n->as_Lock()->obj_node()->uncast();
80 if (!(obj->is_Parm() || obj->is_Con()))
81 return true;
82 }
83 if (n->is_CallStaticJava() &&
84 n->as_CallStaticJava()->is_boxing_method()) {
85 return true;
86 }
87 }
88 return false;
89 }
90
91 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
92 Compile::TracePhase tp("escapeAnalysis", &Phase::timers[Phase::_t_escapeAnalysis]);
93 ResourceMark rm;
94
95 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
96 // to create space for them in ConnectionGraph::_nodes[].
97 Node* oop_null = igvn->zerocon(T_OBJECT);
98 Node* noop_null = igvn->zerocon(T_NARROWOOP);
99 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
100 // Perform escape analysis
101 if (congraph->compute_escape()) {
102 // There are non escaping objects.
103 C->set_congraph(congraph);
104 }
105 // Cleanup.
106 if (oop_null->outcnt() == 0)
107 igvn->hash_delete(oop_null);
108 if (noop_null->outcnt() == 0)
109 igvn->hash_delete(noop_null);
110 }
111
112 bool ConnectionGraph::compute_escape() {
113 Compile* C = _compile;
114 PhaseGVN* igvn = _igvn;
115
116 // Worklists used by EA.
117 Unique_Node_List delayed_worklist;
118 GrowableArray<Node*> alloc_worklist;
119 GrowableArray<Node*> ptr_cmp_worklist;
120 GrowableArray<Node*> storestore_worklist;
121 GrowableArray<ArrayCopyNode*> arraycopy_worklist;
122 GrowableArray<PointsToNode*> ptnodes_worklist;
123 GrowableArray<JavaObjectNode*> java_objects_worklist;
124 GrowableArray<JavaObjectNode*> non_escaped_worklist;
125 GrowableArray<FieldNode*> oop_fields_worklist;
126 DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
127
128 { Compile::TracePhase tp("connectionGraph", &Phase::timers[Phase::_t_connectionGraph]);
129
130 // 1. Populate Connection Graph (CG) with PointsTo nodes.
131 ideal_nodes.map(C->live_nodes(), NULL); // preallocate space
132 // Initialize worklist
133 if (C->root() != NULL) {
134 ideal_nodes.push(C->root());
135 }
136 // Processed ideal nodes are unique on ideal_nodes list
137 // but several ideal nodes are mapped to the phantom_obj.
138 // To avoid duplicated entries on the following worklists
139 // add the phantom_obj only once to them.
140 ptnodes_worklist.append(phantom_obj);
141 java_objects_worklist.append(phantom_obj);
142 for( uint next = 0; next < ideal_nodes.size(); ++next ) {
143 Node* n = ideal_nodes.at(next);
144 // Create PointsTo nodes and add them to Connection Graph. Called
145 // only once per ideal node since ideal_nodes is Unique_Node list.
146 add_node_to_connection_graph(n, &delayed_worklist);
147 PointsToNode* ptn = ptnode_adr(n->_idx);
148 if (ptn != NULL && ptn != phantom_obj) {
149 ptnodes_worklist.append(ptn);
150 if (ptn->is_JavaObject()) {
151 java_objects_worklist.append(ptn->as_JavaObject());
152 if ((n->is_Allocate() || n->is_CallStaticJava()) &&
153 (ptn->escape_state() < PointsToNode::GlobalEscape)) {
154 // Only allocations and java static calls results are interesting.
155 non_escaped_worklist.append(ptn->as_JavaObject());
156 }
157 } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
158 oop_fields_worklist.append(ptn->as_Field());
159 }
160 }
161 if (n->is_MergeMem()) {
162 // Collect all MergeMem nodes to add memory slices for
163 // scalar replaceable objects in split_unique_types().
164 _mergemem_worklist.append(n->as_MergeMem());
165 } else if (OptimizePtrCompare && n->is_Cmp() &&
166 (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
167 // Collect compare pointers nodes.
168 ptr_cmp_worklist.append(n);
169 } else if (n->is_MemBarStoreStore()) {
170 // Collect all MemBarStoreStore nodes so that depending on the
171 // escape status of the associated Allocate node some of them
172 // may be eliminated.
173 storestore_worklist.append(n);
174 } else if (n->is_MemBar() && (n->Opcode() == Op_MemBarRelease) &&
175 (n->req() > MemBarNode::Precedent)) {
176 record_for_optimizer(n);
177 #ifdef ASSERT
178 } else if (n->is_AddP()) {
179 // Collect address nodes for graph verification.
180 addp_worklist.append(n);
181 #endif
182 } else if (n->is_ArrayCopy()) {
183 // Keep a list of ArrayCopy nodes so if one of its input is non
184 // escaping, we can record a unique type
185 arraycopy_worklist.append(n->as_ArrayCopy());
186 }
187 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
188 Node* m = n->fast_out(i); // Get user
189 ideal_nodes.push(m);
190 }
191 }
192 if (non_escaped_worklist.length() == 0) {
193 _collecting = false;
194 return false; // Nothing to do.
195 }
196 // Add final simple edges to graph.
197 while(delayed_worklist.size() > 0) {
198 Node* n = delayed_worklist.pop();
199 add_final_edges(n);
200 }
201 int ptnodes_length = ptnodes_worklist.length();
202
203 #ifdef ASSERT
204 if (VerifyConnectionGraph) {
205 // Verify that no new simple edges could be created and all
206 // local vars has edges.
207 _verify = true;
208 for (int next = 0; next < ptnodes_length; ++next) {
209 PointsToNode* ptn = ptnodes_worklist.at(next);
210 add_final_edges(ptn->ideal_node());
211 if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
212 ptn->dump();
213 assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");
214 }
215 }
216 _verify = false;
217 }
218 #endif
219 // Bytecode analyzer BCEscapeAnalyzer, used for Call nodes
220 // processing, calls to CI to resolve symbols (types, fields, methods)
221 // referenced in bytecode. During symbol resolution VM may throw
222 // an exception which CI cleans and converts to compilation failure.
223 if (C->failing()) return false;
224
225 // 2. Finish Graph construction by propagating references to all
226 // java objects through graph.
227 if (!complete_connection_graph(ptnodes_worklist, non_escaped_worklist,
228 java_objects_worklist, oop_fields_worklist)) {
229 // All objects escaped or hit time or iterations limits.
230 _collecting = false;
231 return false;
232 }
233
234 // 3. Adjust scalar_replaceable state of nonescaping objects and push
235 // scalar replaceable allocations on alloc_worklist for processing
236 // in split_unique_types().
237 int non_escaped_length = non_escaped_worklist.length();
238 for (int next = 0; next < non_escaped_length; next++) {
239 JavaObjectNode* ptn = non_escaped_worklist.at(next);
240 bool noescape = (ptn->escape_state() == PointsToNode::NoEscape);
241 Node* n = ptn->ideal_node();
242 if (n->is_Allocate()) {
243 n->as_Allocate()->_is_non_escaping = noescape;
244 }
245 if (n->is_CallStaticJava()) {
246 n->as_CallStaticJava()->_is_non_escaping = noescape;
247 }
248 if (noescape && ptn->scalar_replaceable()) {
249 adjust_scalar_replaceable_state(ptn);
250 if (ptn->scalar_replaceable()) {
251 alloc_worklist.append(ptn->ideal_node());
252 }
253 }
254 }
255
256 #ifdef ASSERT
257 if (VerifyConnectionGraph) {
258 // Verify that graph is complete - no new edges could be added or needed.
259 verify_connection_graph(ptnodes_worklist, non_escaped_worklist,
260 java_objects_worklist, addp_worklist);
261 }
262 assert(C->unique() == nodes_size(), "no new ideal nodes should be added during ConnectionGraph build");
263 assert(null_obj->escape_state() == PointsToNode::NoEscape &&
264 null_obj->edge_count() == 0 &&
265 !null_obj->arraycopy_src() &&
266 !null_obj->arraycopy_dst(), "sanity");
267 #endif
268
269 _collecting = false;
270
271 } // TracePhase t3("connectionGraph")
272
273 // 4. Optimize ideal graph based on EA information.
274 bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
275 if (has_non_escaping_obj) {
276 optimize_ideal_graph(ptr_cmp_worklist, storestore_worklist);
277 }
278
279 #ifndef PRODUCT
280 if (PrintEscapeAnalysis) {
281 dump(ptnodes_worklist); // Dump ConnectionGraph
282 }
283 #endif
284
285 bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
286 #ifdef ASSERT
287 if (VerifyConnectionGraph) {
288 int alloc_length = alloc_worklist.length();
289 for (int next = 0; next < alloc_length; ++next) {
290 Node* n = alloc_worklist.at(next);
291 PointsToNode* ptn = ptnode_adr(n->_idx);
292 assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");
293 }
294 }
295 #endif
296
297 // 5. Separate memory graph for scalar replaceable allcations.
298 if (has_scalar_replaceable_candidates &&
299 C->AliasLevel() >= 3 && EliminateAllocations) {
300 // Now use the escape information to create unique types for
301 // scalar replaceable objects.
302 split_unique_types(alloc_worklist, arraycopy_worklist);
303 if (C->failing()) return false;
304 C->print_method(PHASE_AFTER_EA, 2);
305
306 #ifdef ASSERT
307 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
308 tty->print("=== No allocations eliminated for ");
309 C->method()->print_short_name();
310 if(!EliminateAllocations) {
311 tty->print(" since EliminateAllocations is off ===");
312 } else if(!has_scalar_replaceable_candidates) {
313 tty->print(" since there are no scalar replaceable candidates ===");
314 } else if(C->AliasLevel() < 3) {
315 tty->print(" since AliasLevel < 3 ===");
316 }
317 tty->cr();
318 #endif
319 }
320 return has_non_escaping_obj;
321 }
322
323 // Utility function for nodes that load an object
324 void ConnectionGraph::add_objload_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
325 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
326 // ThreadLocal has RawPtr type.
327 const Type* t = _igvn->type(n);
328 if (t->make_ptr() != NULL) {
329 Node* adr = n->in(MemNode::Address);
330 #ifdef ASSERT
331 if (!adr->is_AddP()) {
332 assert(_igvn->type(adr)->isa_rawptr(), "sanity");
333 } else {
334 assert((ptnode_adr(adr->_idx) == NULL ||
335 ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
336 }
337 #endif
338 add_local_var_and_edge(n, PointsToNode::NoEscape,
339 adr, delayed_worklist);
340 }
341 }
342
343 // Populate Connection Graph with PointsTo nodes and create simple
344 // connection graph edges.
345 void ConnectionGraph::add_node_to_connection_graph(Node *n, Unique_Node_List *delayed_worklist) {
346 assert(!_verify, "this method should not be called for verification");
347 PhaseGVN* igvn = _igvn;
348 uint n_idx = n->_idx;
349 PointsToNode* n_ptn = ptnode_adr(n_idx);
350 if (n_ptn != NULL)
351 return; // No need to redefine PointsTo node during first iteration.
352
353 if (n->is_Call()) {
354 // Arguments to allocation and locking don't escape.
355 if (n->is_AbstractLock()) {
356 // Put Lock and Unlock nodes on IGVN worklist to process them during
357 // first IGVN optimization when escape information is still available.
358 record_for_optimizer(n);
359 } else if (n->is_Allocate()) {
360 add_call_node(n->as_Call());
361 record_for_optimizer(n);
362 } else {
363 if (n->is_CallStaticJava()) {
364 const char* name = n->as_CallStaticJava()->_name;
365 if (name != NULL && strcmp(name, "uncommon_trap") == 0)
366 return; // Skip uncommon traps
367 }
368 // Don't mark as processed since call's arguments have to be processed.
369 delayed_worklist->push(n);
370 // Check if a call returns an object.
371 if ((n->as_Call()->returns_pointer() &&
372 n->as_Call()->proj_out_or_null(TypeFunc::Parms) != NULL) ||
373 (n->is_CallStaticJava() &&
374 n->as_CallStaticJava()->is_boxing_method())) {
375 add_call_node(n->as_Call());
376 }
377 }
378 return;
379 }
380 // Put this check here to process call arguments since some call nodes
381 // point to phantom_obj.
382 if (n_ptn == phantom_obj || n_ptn == null_obj)
383 return; // Skip predefined nodes.
384
385 int opcode = n->Opcode();
386 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_to_con_graph(this, igvn, delayed_worklist, n, opcode);
387 if (gc_handled) {
388 return; // Ignore node if already handled by GC.
389 }
390 switch (opcode) {
391 case Op_AddP: {
392 Node* base = get_addp_base(n);
393 PointsToNode* ptn_base = ptnode_adr(base->_idx);
394 // Field nodes are created for all field types. They are used in
395 // adjust_scalar_replaceable_state() and split_unique_types().
396 // Note, non-oop fields will have only base edges in Connection
397 // Graph because such fields are not used for oop loads and stores.
398 int offset = address_offset(n, igvn);
399 add_field(n, PointsToNode::NoEscape, offset);
400 if (ptn_base == NULL) {
401 delayed_worklist->push(n); // Process it later.
402 } else {
403 n_ptn = ptnode_adr(n_idx);
404 add_base(n_ptn->as_Field(), ptn_base);
405 }
406 break;
407 }
408 case Op_CastX2P: {
409 map_ideal_node(n, phantom_obj);
410 break;
411 }
412 case Op_CastPP:
413 case Op_CheckCastPP:
414 case Op_EncodeP:
415 case Op_DecodeN:
416 case Op_EncodePKlass:
417 case Op_DecodeNKlass: {
418 add_local_var_and_edge(n, PointsToNode::NoEscape,
419 n->in(1), delayed_worklist);
420 break;
421 }
422 case Op_CMoveP: {
423 add_local_var(n, PointsToNode::NoEscape);
424 // Do not add edges during first iteration because some could be
425 // not defined yet.
426 delayed_worklist->push(n);
427 break;
428 }
429 case Op_ConP:
430 case Op_ConN:
431 case Op_ConNKlass: {
432 // assume all oop constants globally escape except for null
433 PointsToNode::EscapeState es;
434 const Type* t = igvn->type(n);
435 if (t == TypePtr::NULL_PTR || t == TypeNarrowOop::NULL_PTR) {
436 es = PointsToNode::NoEscape;
437 } else {
438 es = PointsToNode::GlobalEscape;
439 }
440 add_java_object(n, es);
441 break;
442 }
443 case Op_CreateEx: {
444 // assume that all exception objects globally escape
445 map_ideal_node(n, phantom_obj);
446 break;
447 }
448 case Op_LoadKlass:
449 case Op_LoadNKlass: {
450 // Unknown class is loaded
451 map_ideal_node(n, phantom_obj);
452 break;
453 }
454 case Op_LoadP:
455 case Op_LoadN:
456 case Op_LoadPLocked: {
457 add_objload_to_connection_graph(n, delayed_worklist);
458 break;
459 }
460 case Op_Parm: {
461 map_ideal_node(n, phantom_obj);
462 break;
463 }
464 case Op_PartialSubtypeCheck: {
465 // Produces Null or notNull and is used in only in CmpP so
466 // phantom_obj could be used.
467 map_ideal_node(n, phantom_obj); // Result is unknown
468 break;
469 }
470 case Op_Phi: {
471 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
472 // ThreadLocal has RawPtr type.
473 const Type* t = n->as_Phi()->type();
474 if (t->make_ptr() != NULL) {
475 add_local_var(n, PointsToNode::NoEscape);
476 // Do not add edges during first iteration because some could be
477 // not defined yet.
478 delayed_worklist->push(n);
479 }
480 break;
481 }
482 case Op_Proj: {
483 // we are only interested in the oop result projection from a call
484 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
485 n->in(0)->as_Call()->returns_pointer()) {
486 add_local_var_and_edge(n, PointsToNode::NoEscape,
487 n->in(0), delayed_worklist);
488 }
489 break;
490 }
491 case Op_Rethrow: // Exception object escapes
492 case Op_Return: {
493 if (n->req() > TypeFunc::Parms &&
494 igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
495 // Treat Return value as LocalVar with GlobalEscape escape state.
496 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
497 n->in(TypeFunc::Parms), delayed_worklist);
498 }
499 break;
500 }
501 case Op_CompareAndExchangeP:
502 case Op_CompareAndExchangeN:
503 case Op_GetAndSetP:
504 case Op_GetAndSetN: {
505 add_objload_to_connection_graph(n, delayed_worklist);
506 // fallthrough
507 }
508 case Op_StoreP:
509 case Op_StoreN:
510 case Op_StoreNKlass:
511 case Op_StorePConditional:
512 case Op_WeakCompareAndSwapP:
513 case Op_WeakCompareAndSwapN:
514 case Op_CompareAndSwapP:
515 case Op_CompareAndSwapN: {
516 add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
517 break;
518 }
519 case Op_AryEq:
520 case Op_HasNegatives:
521 case Op_StrComp:
522 case Op_StrEquals:
523 case Op_StrIndexOf:
524 case Op_StrIndexOfChar:
525 case Op_StrInflatedCopy:
526 case Op_StrCompressedCopy:
527 case Op_EncodeISOArray: {
528 add_local_var(n, PointsToNode::ArgEscape);
529 delayed_worklist->push(n); // Process it later.
530 break;
531 }
532 case Op_ThreadLocal: {
533 add_java_object(n, PointsToNode::ArgEscape);
534 break;
535 }
536 default:
537 ; // Do nothing for nodes not related to EA.
538 }
539 return;
540 }
541
542 #ifdef ASSERT
543 #define ELSE_FAIL(name) \
544 /* Should not be called for not pointer type. */ \
545 n->dump(1); \
546 assert(false, name); \
547 break;
548 #else
549 #define ELSE_FAIL(name) \
550 break;
551 #endif
552
553 // Add final simple edges to graph.
554 void ConnectionGraph::add_final_edges(Node *n) {
555 PointsToNode* n_ptn = ptnode_adr(n->_idx);
556 #ifdef ASSERT
557 if (_verify && n_ptn->is_JavaObject())
558 return; // This method does not change graph for JavaObject.
559 #endif
560
561 if (n->is_Call()) {
562 process_call_arguments(n->as_Call());
563 return;
564 }
565 assert(n->is_Store() || n->is_LoadStore() ||
566 (n_ptn != NULL) && (n_ptn->ideal_node() != NULL),
567 "node should be registered already");
568 int opcode = n->Opcode();
569 bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->escape_add_final_edges(this, _igvn, n, opcode);
570 if (gc_handled) {
571 return; // Ignore node if already handled by GC.
572 }
573 switch (opcode) {
574 case Op_AddP: {
575 Node* base = get_addp_base(n);
576 PointsToNode* ptn_base = ptnode_adr(base->_idx);
577 assert(ptn_base != NULL, "field's base should be registered");
578 add_base(n_ptn->as_Field(), ptn_base);
579 break;
580 }
581 case Op_CastPP:
582 case Op_CheckCastPP:
583 case Op_EncodeP:
584 case Op_DecodeN:
585 case Op_EncodePKlass:
586 case Op_DecodeNKlass: {
587 add_local_var_and_edge(n, PointsToNode::NoEscape,
588 n->in(1), NULL);
589 break;
590 }
591 case Op_CMoveP: {
592 for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {
593 Node* in = n->in(i);
594 if (in == NULL)
595 continue; // ignore NULL
596 Node* uncast_in = in->uncast();
597 if (uncast_in->is_top() || uncast_in == n)
598 continue; // ignore top or inputs which go back this node
599 PointsToNode* ptn = ptnode_adr(in->_idx);
600 assert(ptn != NULL, "node should be registered");
601 add_edge(n_ptn, ptn);
602 }
603 break;
604 }
605 case Op_LoadP:
606 case Op_LoadN:
607 case Op_LoadPLocked: {
608 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
609 // ThreadLocal has RawPtr type.
610 const Type* t = _igvn->type(n);
611 if (t->make_ptr() != NULL) {
612 Node* adr = n->in(MemNode::Address);
613 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
614 break;
615 }
616 ELSE_FAIL("Op_LoadP");
617 }
618 case Op_Phi: {
619 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
620 // ThreadLocal has RawPtr type.
621 const Type* t = n->as_Phi()->type();
622 if (t->make_ptr() != NULL) {
623 for (uint i = 1; i < n->req(); i++) {
624 Node* in = n->in(i);
625 if (in == NULL)
626 continue; // ignore NULL
627 Node* uncast_in = in->uncast();
628 if (uncast_in->is_top() || uncast_in == n)
629 continue; // ignore top or inputs which go back this node
630 PointsToNode* ptn = ptnode_adr(in->_idx);
631 assert(ptn != NULL, "node should be registered");
632 add_edge(n_ptn, ptn);
633 }
634 break;
635 }
636 ELSE_FAIL("Op_Phi");
637 }
638 case Op_Proj: {
639 // we are only interested in the oop result projection from a call
640 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
641 n->in(0)->as_Call()->returns_pointer()) {
642 add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(0), NULL);
643 break;
644 }
645 ELSE_FAIL("Op_Proj");
646 }
647 case Op_Rethrow: // Exception object escapes
648 case Op_Return: {
649 if (n->req() > TypeFunc::Parms &&
650 _igvn->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
651 // Treat Return value as LocalVar with GlobalEscape escape state.
652 add_local_var_and_edge(n, PointsToNode::GlobalEscape,
653 n->in(TypeFunc::Parms), NULL);
654 break;
655 }
656 ELSE_FAIL("Op_Return");
657 }
658 case Op_StoreP:
659 case Op_StoreN:
660 case Op_StoreNKlass:
661 case Op_StorePConditional:
662 case Op_CompareAndExchangeP:
663 case Op_CompareAndExchangeN:
664 case Op_CompareAndSwapP:
665 case Op_CompareAndSwapN:
666 case Op_WeakCompareAndSwapP:
667 case Op_WeakCompareAndSwapN:
668 case Op_GetAndSetP:
669 case Op_GetAndSetN: {
670 if (add_final_edges_unsafe_access(n, opcode)) {
671 break;
672 }
673 ELSE_FAIL("Op_StoreP");
674 }
675 case Op_AryEq:
676 case Op_HasNegatives:
677 case Op_StrComp:
678 case Op_StrEquals:
679 case Op_StrIndexOf:
680 case Op_StrIndexOfChar:
681 case Op_StrInflatedCopy:
682 case Op_StrCompressedCopy:
683 case Op_EncodeISOArray: {
684 // char[]/byte[] arrays passed to string intrinsic do not escape but
685 // they are not scalar replaceable. Adjust escape state for them.
686 // Start from in(2) edge since in(1) is memory edge.
687 for (uint i = 2; i < n->req(); i++) {
688 Node* adr = n->in(i);
689 const Type* at = _igvn->type(adr);
690 if (!adr->is_top() && at->isa_ptr()) {
691 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
692 at->isa_ptr() != NULL, "expecting a pointer");
693 if (adr->is_AddP()) {
694 adr = get_addp_base(adr);
695 }
696 PointsToNode* ptn = ptnode_adr(adr->_idx);
697 assert(ptn != NULL, "node should be registered");
698 add_edge(n_ptn, ptn);
699 }
700 }
701 break;
702 }
703 default: {
704 // This method should be called only for EA specific nodes which may
705 // miss some edges when they were created.
706 #ifdef ASSERT
707 n->dump(1);
708 #endif
709 guarantee(false, "unknown node");
710 }
711 }
712 return;
713 }
714
715 void ConnectionGraph::add_to_congraph_unsafe_access(Node* n, uint opcode, Unique_Node_List* delayed_worklist) {
716 Node* adr = n->in(MemNode::Address);
717 const Type* adr_type = _igvn->type(adr);
718 adr_type = adr_type->make_ptr();
719 if (adr_type == NULL) {
720 return; // skip dead nodes
721 }
722 if (adr_type->isa_oopptr()
723 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
724 && adr_type == TypeRawPtr::NOTNULL
725 && adr->in(AddPNode::Address)->is_Proj()
726 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
727 delayed_worklist->push(n); // Process it later.
728 #ifdef ASSERT
729 assert (adr->is_AddP(), "expecting an AddP");
730 if (adr_type == TypeRawPtr::NOTNULL) {
731 // Verify a raw address for a store captured by Initialize node.
732 int offs = (int) _igvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
733 assert(offs != Type::OffsetBot, "offset must be a constant");
734 }
735 #endif
736 } else {
737 // Ignore copy the displaced header to the BoxNode (OSR compilation).
738 if (adr->is_BoxLock()) {
739 return;
740 }
741 // Stored value escapes in unsafe access.
742 if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
743 delayed_worklist->push(n); // Process unsafe access later.
744 return;
745 }
746 #ifdef ASSERT
747 n->dump(1);
748 assert(false, "not unsafe");
749 #endif
750 }
751 }
752
753 bool ConnectionGraph::add_final_edges_unsafe_access(Node* n, uint opcode) {
754 Node* adr = n->in(MemNode::Address);
755 const Type *adr_type = _igvn->type(adr);
756 adr_type = adr_type->make_ptr();
757 #ifdef ASSERT
758 if (adr_type == NULL) {
759 n->dump(1);
760 assert(adr_type != NULL, "dead node should not be on list");
761 return true;
762 }
763 #endif
764
765 if (opcode == Op_GetAndSetP || opcode == Op_GetAndSetN ||
766 opcode == Op_CompareAndExchangeN || opcode == Op_CompareAndExchangeP) {
767 add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
768 }
769
770 if (adr_type->isa_oopptr()
771 || ((opcode == Op_StoreP || opcode == Op_StoreN || opcode == Op_StoreNKlass)
772 && adr_type == TypeRawPtr::NOTNULL
773 && adr->in(AddPNode::Address)->is_Proj()
774 && adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
775 // Point Address to Value
776 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
777 assert(adr_ptn != NULL &&
778 adr_ptn->as_Field()->is_oop(), "node should be registered");
779 Node* val = n->in(MemNode::ValueIn);
780 PointsToNode* ptn = ptnode_adr(val->_idx);
781 assert(ptn != NULL, "node should be registered");
782 add_edge(adr_ptn, ptn);
783 return true;
784 } else if ((opcode == Op_StoreP) && adr_type->isa_rawptr()) {
785 // Stored value escapes in unsafe access.
786 Node* val = n->in(MemNode::ValueIn);
787 PointsToNode* ptn = ptnode_adr(val->_idx);
788 assert(ptn != NULL, "node should be registered");
789 set_escape_state(ptn, PointsToNode::GlobalEscape);
790 // Add edge to object for unsafe access with offset.
791 PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
792 assert(adr_ptn != NULL, "node should be registered");
793 if (adr_ptn->is_Field()) {
794 assert(adr_ptn->as_Field()->is_oop(), "should be oop field");
795 add_edge(adr_ptn, ptn);
796 }
797 return true;
798 }
799 return false;
800 }
801
802 void ConnectionGraph::add_call_node(CallNode* call) {
803 assert(call->returns_pointer(), "only for call which returns pointer");
804 uint call_idx = call->_idx;
805 if (call->is_Allocate()) {
806 Node* k = call->in(AllocateNode::KlassNode);
807 const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
808 assert(kt != NULL, "TypeKlassPtr required.");
809 ciKlass* cik = kt->klass();
810 PointsToNode::EscapeState es = PointsToNode::NoEscape;
811 bool scalar_replaceable = true;
812 if (call->is_AllocateArray()) {
813 if (!cik->is_array_klass()) { // StressReflectiveCode
814 es = PointsToNode::GlobalEscape;
815 } else {
816 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
817 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
818 // Not scalar replaceable if the length is not constant or too big.
819 scalar_replaceable = false;
820 }
821 }
822 } else { // Allocate instance
823 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
824 cik->is_subclass_of(_compile->env()->Reference_klass()) ||
825 !cik->is_instance_klass() || // StressReflectiveCode
826 !cik->as_instance_klass()->can_be_instantiated() ||
827 cik->as_instance_klass()->has_finalizer()) {
828 es = PointsToNode::GlobalEscape;
829 }
830 }
831 add_java_object(call, es);
832 PointsToNode* ptn = ptnode_adr(call_idx);
833 if (!scalar_replaceable && ptn->scalar_replaceable()) {
834 ptn->set_scalar_replaceable(false);
835 }
836 } else if (call->is_CallStaticJava()) {
837 // Call nodes could be different types:
838 //
839 // 1. CallDynamicJavaNode (what happened during call is unknown):
840 //
841 // - mapped to GlobalEscape JavaObject node if oop is returned;
842 //
843 // - all oop arguments are escaping globally;
844 //
845 // 2. CallStaticJavaNode (execute bytecode analysis if possible):
846 //
847 // - the same as CallDynamicJavaNode if can't do bytecode analysis;
848 //
849 // - mapped to GlobalEscape JavaObject node if unknown oop is returned;
850 // - mapped to NoEscape JavaObject node if non-escaping object allocated
851 // during call is returned;
852 // - mapped to ArgEscape LocalVar node pointed to object arguments
853 // which are returned and does not escape during call;
854 //
855 // - oop arguments escaping status is defined by bytecode analysis;
856 //
857 // For a static call, we know exactly what method is being called.
858 // Use bytecode estimator to record whether the call's return value escapes.
859 ciMethod* meth = call->as_CallJava()->method();
860 if (meth == NULL) {
861 const char* name = call->as_CallStaticJava()->_name;
862 assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
863 // Returns a newly allocated unescaped object.
864 add_java_object(call, PointsToNode::NoEscape);
865 ptnode_adr(call_idx)->set_scalar_replaceable(false);
866 } else if (meth->is_boxing_method()) {
867 // Returns boxing object
868 PointsToNode::EscapeState es;
869 vmIntrinsics::ID intr = meth->intrinsic_id();
870 if (intr == vmIntrinsics::_floatValue || intr == vmIntrinsics::_doubleValue) {
871 // It does not escape if object is always allocated.
872 es = PointsToNode::NoEscape;
873 } else {
874 // It escapes globally if object could be loaded from cache.
875 es = PointsToNode::GlobalEscape;
876 }
877 add_java_object(call, es);
878 } else {
879 BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
880 call_analyzer->copy_dependencies(_compile->dependencies());
881 if (call_analyzer->is_return_allocated()) {
882 // Returns a newly allocated unescaped object, simply
883 // update dependency information.
884 // Mark it as NoEscape so that objects referenced by
885 // it's fields will be marked as NoEscape at least.
886 add_java_object(call, PointsToNode::NoEscape);
887 ptnode_adr(call_idx)->set_scalar_replaceable(false);
888 } else {
889 // Determine whether any arguments are returned.
890 const TypeTuple* d = call->tf()->domain();
891 bool ret_arg = false;
892 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
893 if (d->field_at(i)->isa_ptr() != NULL &&
894 call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
895 ret_arg = true;
896 break;
897 }
898 }
899 if (ret_arg) {
900 add_local_var(call, PointsToNode::ArgEscape);
901 } else {
902 // Returns unknown object.
903 map_ideal_node(call, phantom_obj);
904 }
905 }
906 }
907 } else {
908 // An other type of call, assume the worst case:
909 // returned value is unknown and globally escapes.
910 assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
911 map_ideal_node(call, phantom_obj);
912 }
913 }
914
915 void ConnectionGraph::process_call_arguments(CallNode *call) {
916 bool is_arraycopy = false;
917 switch (call->Opcode()) {
918 #ifdef ASSERT
919 case Op_Allocate:
920 case Op_AllocateArray:
921 case Op_Lock:
922 case Op_Unlock:
923 assert(false, "should be done already");
924 break;
925 #endif
926 case Op_ArrayCopy:
927 case Op_CallLeafNoFP:
928 // Most array copies are ArrayCopy nodes at this point but there
929 // are still a few direct calls to the copy subroutines (See
930 // PhaseStringOpts::copy_string())
931 is_arraycopy = (call->Opcode() == Op_ArrayCopy) ||
932 call->as_CallLeaf()->is_call_to_arraycopystub();
933 // fall through
934 case Op_CallLeaf: {
935 // Stub calls, objects do not escape but they are not scale replaceable.
936 // Adjust escape state for outgoing arguments.
937 const TypeTuple * d = call->tf()->domain();
938 bool src_has_oops = false;
939 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
940 const Type* at = d->field_at(i);
941 Node *arg = call->in(i);
942 if (arg == NULL) {
943 continue;
944 }
945 const Type *aat = _igvn->type(arg);
946 if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
947 continue;
948 if (arg->is_AddP()) {
949 //
950 // The inline_native_clone() case when the arraycopy stub is called
951 // after the allocation before Initialize and CheckCastPP nodes.
952 // Or normal arraycopy for object arrays case.
953 //
954 // Set AddP's base (Allocate) as not scalar replaceable since
955 // pointer to the base (with offset) is passed as argument.
956 //
957 arg = get_addp_base(arg);
958 }
959 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
960 assert(arg_ptn != NULL, "should be registered");
961 PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
962 if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
963 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
964 aat->isa_ptr() != NULL, "expecting an Ptr");
965 bool arg_has_oops = aat->isa_oopptr() &&
966 (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
967 (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
968 if (i == TypeFunc::Parms) {
969 src_has_oops = arg_has_oops;
970 }
971 //
972 // src or dst could be j.l.Object when other is basic type array:
973 //
974 // arraycopy(char[],0,Object*,0,size);
975 // arraycopy(Object*,0,char[],0,size);
976 //
977 // Don't add edges in such cases.
978 //
979 bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
980 arg_has_oops && (i > TypeFunc::Parms);
981 #ifdef ASSERT
982 if (!(is_arraycopy ||
983 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(call) ||
984 (call->as_CallLeaf()->_name != NULL &&
985 (strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32") == 0 ||
986 strcmp(call->as_CallLeaf()->_name, "updateBytesCRC32C") == 0 ||
987 strcmp(call->as_CallLeaf()->_name, "updateBytesAdler32") == 0 ||
988 strcmp(call->as_CallLeaf()->_name, "aescrypt_encryptBlock") == 0 ||
989 strcmp(call->as_CallLeaf()->_name, "aescrypt_decryptBlock") == 0 ||
990 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_encryptAESCrypt") == 0 ||
991 strcmp(call->as_CallLeaf()->_name, "cipherBlockChaining_decryptAESCrypt") == 0 ||
992 strcmp(call->as_CallLeaf()->_name, "counterMode_AESCrypt") == 0 ||
993 strcmp(call->as_CallLeaf()->_name, "ghash_processBlocks") == 0 ||
994 strcmp(call->as_CallLeaf()->_name, "encodeBlock") == 0 ||
995 strcmp(call->as_CallLeaf()->_name, "sha1_implCompress") == 0 ||
996 strcmp(call->as_CallLeaf()->_name, "sha1_implCompressMB") == 0 ||
997 strcmp(call->as_CallLeaf()->_name, "sha256_implCompress") == 0 ||
998 strcmp(call->as_CallLeaf()->_name, "sha256_implCompressMB") == 0 ||
999 strcmp(call->as_CallLeaf()->_name, "sha512_implCompress") == 0 ||
1000 strcmp(call->as_CallLeaf()->_name, "sha512_implCompressMB") == 0 ||
1001 strcmp(call->as_CallLeaf()->_name, "multiplyToLen") == 0 ||
1002 strcmp(call->as_CallLeaf()->_name, "squareToLen") == 0 ||
1003 strcmp(call->as_CallLeaf()->_name, "mulAdd") == 0 ||
1004 strcmp(call->as_CallLeaf()->_name, "montgomery_multiply") == 0 ||
1005 strcmp(call->as_CallLeaf()->_name, "montgomery_square") == 0 ||
1006 strcmp(call->as_CallLeaf()->_name, "vectorizedMismatch") == 0)
1007 ))) {
1008 call->dump();
1009 fatal("EA unexpected CallLeaf %s", call->as_CallLeaf()->_name);
1010 }
1011 #endif
1012 // Always process arraycopy's destination object since
1013 // we need to add all possible edges to references in
1014 // source object.
1015 if (arg_esc >= PointsToNode::ArgEscape &&
1016 !arg_is_arraycopy_dest) {
1017 continue;
1018 }
1019 PointsToNode::EscapeState es = PointsToNode::ArgEscape;
1020 if (call->is_ArrayCopy()) {
1021 ArrayCopyNode* ac = call->as_ArrayCopy();
1022 if (ac->is_clonebasic() ||
1023 ac->is_arraycopy_validated() ||
1024 ac->is_copyof_validated() ||
1025 ac->is_copyofrange_validated()) {
1026 es = PointsToNode::NoEscape;
1027 }
1028 }
1029 set_escape_state(arg_ptn, es);
1030 if (arg_is_arraycopy_dest) {
1031 Node* src = call->in(TypeFunc::Parms);
1032 if (src->is_AddP()) {
1033 src = get_addp_base(src);
1034 }
1035 PointsToNode* src_ptn = ptnode_adr(src->_idx);
1036 assert(src_ptn != NULL, "should be registered");
1037 if (arg_ptn != src_ptn) {
1038 // Special arraycopy edge:
1039 // A destination object's field can't have the source object
1040 // as base since objects escape states are not related.
1041 // Only escape state of destination object's fields affects
1042 // escape state of fields in source object.
1043 add_arraycopy(call, es, src_ptn, arg_ptn);
1044 }
1045 }
1046 }
1047 }
1048 break;
1049 }
1050 case Op_CallStaticJava: {
1051 // For a static call, we know exactly what method is being called.
1052 // Use bytecode estimator to record the call's escape affects
1053 #ifdef ASSERT
1054 const char* name = call->as_CallStaticJava()->_name;
1055 assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
1056 #endif
1057 ciMethod* meth = call->as_CallJava()->method();
1058 if ((meth != NULL) && meth->is_boxing_method()) {
1059 break; // Boxing methods do not modify any oops.
1060 }
1061 BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1062 // fall-through if not a Java method or no analyzer information
1063 if (call_analyzer != NULL) {
1064 PointsToNode* call_ptn = ptnode_adr(call->_idx);
1065 const TypeTuple* d = call->tf()->domain();
1066 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1067 const Type* at = d->field_at(i);
1068 int k = i - TypeFunc::Parms;
1069 Node* arg = call->in(i);
1070 PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
1071 if (at->isa_ptr() != NULL &&
1072 call_analyzer->is_arg_returned(k)) {
1073 // The call returns arguments.
1074 if (call_ptn != NULL) { // Is call's result used?
1075 assert(call_ptn->is_LocalVar(), "node should be registered");
1076 assert(arg_ptn != NULL, "node should be registered");
1077 add_edge(call_ptn, arg_ptn);
1078 }
1079 }
1080 if (at->isa_oopptr() != NULL &&
1081 arg_ptn->escape_state() < PointsToNode::GlobalEscape) {
1082 if (!call_analyzer->is_arg_stack(k)) {
1083 // The argument global escapes
1084 set_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1085 } else {
1086 set_escape_state(arg_ptn, PointsToNode::ArgEscape);
1087 if (!call_analyzer->is_arg_local(k)) {
1088 // The argument itself doesn't escape, but any fields might
1089 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
1090 }
1091 }
1092 }
1093 }
1094 if (call_ptn != NULL && call_ptn->is_LocalVar()) {
1095 // The call returns arguments.
1096 assert(call_ptn->edge_count() > 0, "sanity");
1097 if (!call_analyzer->is_return_local()) {
1098 // Returns also unknown object.
1099 add_edge(call_ptn, phantom_obj);
1100 }
1101 }
1102 break;
1103 }
1104 }
1105 default: {
1106 // Fall-through here if not a Java method or no analyzer information
1107 // or some other type of call, assume the worst case: all arguments
1108 // globally escape.
1109 const TypeTuple* d = call->tf()->domain();
1110 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1111 const Type* at = d->field_at(i);
1112 if (at->isa_oopptr() != NULL) {
1113 Node* arg = call->in(i);
1114 if (arg->is_AddP()) {
1115 arg = get_addp_base(arg);
1116 }
1117 assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
1118 set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
1119 }
1120 }
1121 }
1122 }
1123 }
1124
1125
1126 // Finish Graph construction.
1127 bool ConnectionGraph::complete_connection_graph(
1128 GrowableArray<PointsToNode*>& ptnodes_worklist,
1129 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1130 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1131 GrowableArray<FieldNode*>& oop_fields_worklist) {
1132 // Normally only 1-3 passes needed to build Connection Graph depending
1133 // on graph complexity. Observed 8 passes in jvm2008 compiler.compiler.
1134 // Set limit to 20 to catch situation when something did go wrong and
1135 // bailout Escape Analysis.
1136 // Also limit build time to 20 sec (60 in debug VM), EscapeAnalysisTimeout flag.
1137 #define CG_BUILD_ITER_LIMIT 20
1138
1139 // Propagate GlobalEscape and ArgEscape escape states and check that
1140 // we still have non-escaping objects. The method pushs on _worklist
1141 // Field nodes which reference phantom_object.
1142 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1143 return false; // Nothing to do.
1144 }
1145 // Now propagate references to all JavaObject nodes.
1146 int java_objects_length = java_objects_worklist.length();
1147 elapsedTimer time;
1148 bool timeout = false;
1149 int new_edges = 1;
1150 int iterations = 0;
1151 do {
1152 while ((new_edges > 0) &&
1153 (iterations++ < CG_BUILD_ITER_LIMIT)) {
1154 double start_time = time.seconds();
1155 time.start();
1156 new_edges = 0;
1157 // Propagate references to phantom_object for nodes pushed on _worklist
1158 // by find_non_escaped_objects() and find_field_value().
1159 new_edges += add_java_object_edges(phantom_obj, false);
1160 for (int next = 0; next < java_objects_length; ++next) {
1161 JavaObjectNode* ptn = java_objects_worklist.at(next);
1162 new_edges += add_java_object_edges(ptn, true);
1163
1164 #define SAMPLE_SIZE 4
1165 if ((next % SAMPLE_SIZE) == 0) {
1166 // Each 4 iterations calculate how much time it will take
1167 // to complete graph construction.
1168 time.stop();
1169 // Poll for requests from shutdown mechanism to quiesce compiler
1170 // because Connection graph construction may take long time.
1171 CompileBroker::maybe_block();
1172 double stop_time = time.seconds();
1173 double time_per_iter = (stop_time - start_time) / (double)SAMPLE_SIZE;
1174 double time_until_end = time_per_iter * (double)(java_objects_length - next);
1175 if ((start_time + time_until_end) >= EscapeAnalysisTimeout) {
1176 timeout = true;
1177 break; // Timeout
1178 }
1179 start_time = stop_time;
1180 time.start();
1181 }
1182 #undef SAMPLE_SIZE
1183
1184 }
1185 if (timeout) break;
1186 if (new_edges > 0) {
1187 // Update escape states on each iteration if graph was updated.
1188 if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1189 return false; // Nothing to do.
1190 }
1191 }
1192 time.stop();
1193 if (time.seconds() >= EscapeAnalysisTimeout) {
1194 timeout = true;
1195 break;
1196 }
1197 }
1198 if ((iterations < CG_BUILD_ITER_LIMIT) && !timeout) {
1199 time.start();
1200 // Find fields which have unknown value.
1201 int fields_length = oop_fields_worklist.length();
1202 for (int next = 0; next < fields_length; next++) {
1203 FieldNode* field = oop_fields_worklist.at(next);
1204 if (field->edge_count() == 0) {
1205 new_edges += find_field_value(field);
1206 // This code may added new edges to phantom_object.
1207 // Need an other cycle to propagate references to phantom_object.
1208 }
1209 }
1210 time.stop();
1211 if (time.seconds() >= EscapeAnalysisTimeout) {
1212 timeout = true;
1213 break;
1214 }
1215 } else {
1216 new_edges = 0; // Bailout
1217 }
1218 } while (new_edges > 0);
1219
1220 // Bailout if passed limits.
1221 if ((iterations >= CG_BUILD_ITER_LIMIT) || timeout) {
1222 Compile* C = _compile;
1223 if (C->log() != NULL) {
1224 C->log()->begin_elem("connectionGraph_bailout reason='reached ");
1225 C->log()->text("%s", timeout ? "time" : "iterations");
1226 C->log()->end_elem(" limit'");
1227 }
1228 assert(ExitEscapeAnalysisOnTimeout, "infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1229 time.seconds(), iterations, nodes_size(), ptnodes_worklist.length());
1230 // Possible infinite build_connection_graph loop,
1231 // bailout (no changes to ideal graph were made).
1232 return false;
1233 }
1234 #ifdef ASSERT
1235 if (Verbose && PrintEscapeAnalysis) {
1236 tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1237 iterations, nodes_size(), ptnodes_worklist.length());
1238 }
1239 #endif
1240
1241 #undef CG_BUILD_ITER_LIMIT
1242
1243 // Find fields initialized by NULL for non-escaping Allocations.
1244 int non_escaped_length = non_escaped_worklist.length();
1245 for (int next = 0; next < non_escaped_length; next++) {
1246 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1247 PointsToNode::EscapeState es = ptn->escape_state();
1248 assert(es <= PointsToNode::ArgEscape, "sanity");
1249 if (es == PointsToNode::NoEscape) {
1250 if (find_init_values(ptn, null_obj, _igvn) > 0) {
1251 // Adding references to NULL object does not change escape states
1252 // since it does not escape. Also no fields are added to NULL object.
1253 add_java_object_edges(null_obj, false);
1254 }
1255 }
1256 Node* n = ptn->ideal_node();
1257 if (n->is_Allocate()) {
1258 // The object allocated by this Allocate node will never be
1259 // seen by an other thread. Mark it so that when it is
1260 // expanded no MemBarStoreStore is added.
1261 InitializeNode* ini = n->as_Allocate()->initialization();
1262 if (ini != NULL)
1263 ini->set_does_not_escape();
1264 }
1265 }
1266 return true; // Finished graph construction.
1267 }
1268
1269 // Propagate GlobalEscape and ArgEscape escape states to all nodes
1270 // and check that we still have non-escaping java objects.
1271 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
1272 GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
1273 GrowableArray<PointsToNode*> escape_worklist;
1274 // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
1275 int ptnodes_length = ptnodes_worklist.length();
1276 for (int next = 0; next < ptnodes_length; ++next) {
1277 PointsToNode* ptn = ptnodes_worklist.at(next);
1278 if (ptn->escape_state() >= PointsToNode::ArgEscape ||
1279 ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
1280 escape_worklist.push(ptn);
1281 }
1282 }
1283 // Set escape states to referenced nodes (edges list).
1284 while (escape_worklist.length() > 0) {
1285 PointsToNode* ptn = escape_worklist.pop();
1286 PointsToNode::EscapeState es = ptn->escape_state();
1287 PointsToNode::EscapeState field_es = ptn->fields_escape_state();
1288 if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
1289 es >= PointsToNode::ArgEscape) {
1290 // GlobalEscape or ArgEscape state of field means it has unknown value.
1291 if (add_edge(ptn, phantom_obj)) {
1292 // New edge was added
1293 add_field_uses_to_worklist(ptn->as_Field());
1294 }
1295 }
1296 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1297 PointsToNode* e = i.get();
1298 if (e->is_Arraycopy()) {
1299 assert(ptn->arraycopy_dst(), "sanity");
1300 // Propagate only fields escape state through arraycopy edge.
1301 if (e->fields_escape_state() < field_es) {
1302 set_fields_escape_state(e, field_es);
1303 escape_worklist.push(e);
1304 }
1305 } else if (es >= field_es) {
1306 // fields_escape_state is also set to 'es' if it is less than 'es'.
1307 if (e->escape_state() < es) {
1308 set_escape_state(e, es);
1309 escape_worklist.push(e);
1310 }
1311 } else {
1312 // Propagate field escape state.
1313 bool es_changed = false;
1314 if (e->fields_escape_state() < field_es) {
1315 set_fields_escape_state(e, field_es);
1316 es_changed = true;
1317 }
1318 if ((e->escape_state() < field_es) &&
1319 e->is_Field() && ptn->is_JavaObject() &&
1320 e->as_Field()->is_oop()) {
1321 // Change escape state of referenced fields.
1322 set_escape_state(e, field_es);
1323 es_changed = true;
1324 } else if (e->escape_state() < es) {
1325 set_escape_state(e, es);
1326 es_changed = true;
1327 }
1328 if (es_changed) {
1329 escape_worklist.push(e);
1330 }
1331 }
1332 }
1333 }
1334 // Remove escaped objects from non_escaped list.
1335 for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
1336 JavaObjectNode* ptn = non_escaped_worklist.at(next);
1337 if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
1338 non_escaped_worklist.delete_at(next);
1339 }
1340 if (ptn->escape_state() == PointsToNode::NoEscape) {
1341 // Find fields in non-escaped allocations which have unknown value.
1342 find_init_values(ptn, phantom_obj, NULL);
1343 }
1344 }
1345 return (non_escaped_worklist.length() > 0);
1346 }
1347
1348 // Add all references to JavaObject node by walking over all uses.
1349 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj, bool populate_worklist) {
1350 int new_edges = 0;
1351 if (populate_worklist) {
1352 // Populate _worklist by uses of jobj's uses.
1353 for (UseIterator i(jobj); i.has_next(); i.next()) {
1354 PointsToNode* use = i.get();
1355 if (use->is_Arraycopy())
1356 continue;
1357 add_uses_to_worklist(use);
1358 if (use->is_Field() && use->as_Field()->is_oop()) {
1359 // Put on worklist all field's uses (loads) and
1360 // related field nodes (same base and offset).
1361 add_field_uses_to_worklist(use->as_Field());
1362 }
1363 }
1364 }
1365 for (int l = 0; l < _worklist.length(); l++) {
1366 PointsToNode* use = _worklist.at(l);
1367 if (PointsToNode::is_base_use(use)) {
1368 // Add reference from jobj to field and from field to jobj (field's base).
1369 use = PointsToNode::get_use_node(use)->as_Field();
1370 if (add_base(use->as_Field(), jobj)) {
1371 new_edges++;
1372 }
1373 continue;
1374 }
1375 assert(!use->is_JavaObject(), "sanity");
1376 if (use->is_Arraycopy()) {
1377 if (jobj == null_obj) // NULL object does not have field edges
1378 continue;
1379 // Added edge from Arraycopy node to arraycopy's source java object
1380 if (add_edge(use, jobj)) {
1381 jobj->set_arraycopy_src();
1382 new_edges++;
1383 }
1384 // and stop here.
1385 continue;
1386 }
1387 if (!add_edge(use, jobj))
1388 continue; // No new edge added, there was such edge already.
1389 new_edges++;
1390 if (use->is_LocalVar()) {
1391 add_uses_to_worklist(use);
1392 if (use->arraycopy_dst()) {
1393 for (EdgeIterator i(use); i.has_next(); i.next()) {
1394 PointsToNode* e = i.get();
1395 if (e->is_Arraycopy()) {
1396 if (jobj == null_obj) // NULL object does not have field edges
1397 continue;
1398 // Add edge from arraycopy's destination java object to Arraycopy node.
1399 if (add_edge(jobj, e)) {
1400 new_edges++;
1401 jobj->set_arraycopy_dst();
1402 }
1403 }
1404 }
1405 }
1406 } else {
1407 // Added new edge to stored in field values.
1408 // Put on worklist all field's uses (loads) and
1409 // related field nodes (same base and offset).
1410 add_field_uses_to_worklist(use->as_Field());
1411 }
1412 }
1413 _worklist.clear();
1414 _in_worklist.Reset();
1415 return new_edges;
1416 }
1417
1418 // Put on worklist all related field nodes.
1419 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
1420 assert(field->is_oop(), "sanity");
1421 int offset = field->offset();
1422 add_uses_to_worklist(field);
1423 // Loop over all bases of this field and push on worklist Field nodes
1424 // with the same offset and base (since they may reference the same field).
1425 for (BaseIterator i(field); i.has_next(); i.next()) {
1426 PointsToNode* base = i.get();
1427 add_fields_to_worklist(field, base);
1428 // Check if the base was source object of arraycopy and go over arraycopy's
1429 // destination objects since values stored to a field of source object are
1430 // accessable by uses (loads) of fields of destination objects.
1431 if (base->arraycopy_src()) {
1432 for (UseIterator j(base); j.has_next(); j.next()) {
1433 PointsToNode* arycp = j.get();
1434 if (arycp->is_Arraycopy()) {
1435 for (UseIterator k(arycp); k.has_next(); k.next()) {
1436 PointsToNode* abase = k.get();
1437 if (abase->arraycopy_dst() && abase != base) {
1438 // Look for the same arraycopy reference.
1439 add_fields_to_worklist(field, abase);
1440 }
1441 }
1442 }
1443 }
1444 }
1445 }
1446 }
1447
1448 // Put on worklist all related field nodes.
1449 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
1450 int offset = field->offset();
1451 if (base->is_LocalVar()) {
1452 for (UseIterator j(base); j.has_next(); j.next()) {
1453 PointsToNode* f = j.get();
1454 if (PointsToNode::is_base_use(f)) { // Field
1455 f = PointsToNode::get_use_node(f);
1456 if (f == field || !f->as_Field()->is_oop())
1457 continue;
1458 int offs = f->as_Field()->offset();
1459 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1460 add_to_worklist(f);
1461 }
1462 }
1463 }
1464 } else {
1465 assert(base->is_JavaObject(), "sanity");
1466 if (// Skip phantom_object since it is only used to indicate that
1467 // this field's content globally escapes.
1468 (base != phantom_obj) &&
1469 // NULL object node does not have fields.
1470 (base != null_obj)) {
1471 for (EdgeIterator i(base); i.has_next(); i.next()) {
1472 PointsToNode* f = i.get();
1473 // Skip arraycopy edge since store to destination object field
1474 // does not update value in source object field.
1475 if (f->is_Arraycopy()) {
1476 assert(base->arraycopy_dst(), "sanity");
1477 continue;
1478 }
1479 if (f == field || !f->as_Field()->is_oop())
1480 continue;
1481 int offs = f->as_Field()->offset();
1482 if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
1483 add_to_worklist(f);
1484 }
1485 }
1486 }
1487 }
1488 }
1489
1490 // Find fields which have unknown value.
1491 int ConnectionGraph::find_field_value(FieldNode* field) {
1492 // Escaped fields should have init value already.
1493 assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
1494 int new_edges = 0;
1495 for (BaseIterator i(field); i.has_next(); i.next()) {
1496 PointsToNode* base = i.get();
1497 if (base->is_JavaObject()) {
1498 // Skip Allocate's fields which will be processed later.
1499 if (base->ideal_node()->is_Allocate())
1500 return 0;
1501 assert(base == null_obj, "only NULL ptr base expected here");
1502 }
1503 }
1504 if (add_edge(field, phantom_obj)) {
1505 // New edge was added
1506 new_edges++;
1507 add_field_uses_to_worklist(field);
1508 }
1509 return new_edges;
1510 }
1511
1512 // Find fields initializing values for allocations.
1513 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {
1514 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1515 int new_edges = 0;
1516 Node* alloc = pta->ideal_node();
1517 if (init_val == phantom_obj) {
1518 // Do nothing for Allocate nodes since its fields values are
1519 // "known" unless they are initialized by arraycopy/clone.
1520 if (alloc->is_Allocate() && !pta->arraycopy_dst())
1521 return 0;
1522 assert(pta->arraycopy_dst() || alloc->as_CallStaticJava(), "sanity");
1523 #ifdef ASSERT
1524 if (!pta->arraycopy_dst() && alloc->as_CallStaticJava()->method() == NULL) {
1525 const char* name = alloc->as_CallStaticJava()->_name;
1526 assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
1527 }
1528 #endif
1529 // Non-escaped allocation returned from Java or runtime call have
1530 // unknown values in fields.
1531 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1532 PointsToNode* field = i.get();
1533 if (field->is_Field() && field->as_Field()->is_oop()) {
1534 if (add_edge(field, phantom_obj)) {
1535 // New edge was added
1536 new_edges++;
1537 add_field_uses_to_worklist(field->as_Field());
1538 }
1539 }
1540 }
1541 return new_edges;
1542 }
1543 assert(init_val == null_obj, "sanity");
1544 // Do nothing for Call nodes since its fields values are unknown.
1545 if (!alloc->is_Allocate())
1546 return 0;
1547
1548 InitializeNode* ini = alloc->as_Allocate()->initialization();
1549 bool visited_bottom_offset = false;
1550 GrowableArray<int> offsets_worklist;
1551
1552 // Check if an oop field's initializing value is recorded and add
1553 // a corresponding NULL if field's value if it is not recorded.
1554 // Connection Graph does not record a default initialization by NULL
1555 // captured by Initialize node.
1556 //
1557 for (EdgeIterator i(pta); i.has_next(); i.next()) {
1558 PointsToNode* field = i.get(); // Field (AddP)
1559 if (!field->is_Field() || !field->as_Field()->is_oop())
1560 continue; // Not oop field
1561 int offset = field->as_Field()->offset();
1562 if (offset == Type::OffsetBot) {
1563 if (!visited_bottom_offset) {
1564 // OffsetBot is used to reference array's element,
1565 // always add reference to NULL to all Field nodes since we don't
1566 // known which element is referenced.
1567 if (add_edge(field, null_obj)) {
1568 // New edge was added
1569 new_edges++;
1570 add_field_uses_to_worklist(field->as_Field());
1571 visited_bottom_offset = true;
1572 }
1573 }
1574 } else {
1575 // Check only oop fields.
1576 const Type* adr_type = field->ideal_node()->as_AddP()->bottom_type();
1577 if (adr_type->isa_rawptr()) {
1578 #ifdef ASSERT
1579 // Raw pointers are used for initializing stores so skip it
1580 // since it should be recorded already
1581 Node* base = get_addp_base(field->ideal_node());
1582 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1583 (base->in(0) == alloc),"unexpected pointer type");
1584 #endif
1585 continue;
1586 }
1587 if (!offsets_worklist.contains(offset)) {
1588 offsets_worklist.append(offset);
1589 Node* value = NULL;
1590 if (ini != NULL) {
1591 // StoreP::memory_type() == T_ADDRESS
1592 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_ADDRESS;
1593 Node* store = ini->find_captured_store(offset, type2aelembytes(ft, true), phase);
1594 // Make sure initializing store has the same type as this AddP.
1595 // This AddP may reference non existing field because it is on a
1596 // dead branch of bimorphic call which is not eliminated yet.
1597 if (store != NULL && store->is_Store() &&
1598 store->as_Store()->memory_type() == ft) {
1599 value = store->in(MemNode::ValueIn);
1600 #ifdef ASSERT
1601 if (VerifyConnectionGraph) {
1602 // Verify that AddP already points to all objects the value points to.
1603 PointsToNode* val = ptnode_adr(value->_idx);
1604 assert((val != NULL), "should be processed already");
1605 PointsToNode* missed_obj = NULL;
1606 if (val->is_JavaObject()) {
1607 if (!field->points_to(val->as_JavaObject())) {
1608 missed_obj = val;
1609 }
1610 } else {
1611 if (!val->is_LocalVar() || (val->edge_count() == 0)) {
1612 tty->print_cr("----------init store has invalid value -----");
1613 store->dump();
1614 val->dump();
1615 assert(val->is_LocalVar() && (val->edge_count() > 0), "should be processed already");
1616 }
1617 for (EdgeIterator j(val); j.has_next(); j.next()) {
1618 PointsToNode* obj = j.get();
1619 if (obj->is_JavaObject()) {
1620 if (!field->points_to(obj->as_JavaObject())) {
1621 missed_obj = obj;
1622 break;
1623 }
1624 }
1625 }
1626 }
1627 if (missed_obj != NULL) {
1628 tty->print_cr("----------field---------------------------------");
1629 field->dump();
1630 tty->print_cr("----------missed referernce to object-----------");
1631 missed_obj->dump();
1632 tty->print_cr("----------object referernced by init store -----");
1633 store->dump();
1634 val->dump();
1635 assert(!field->points_to(missed_obj->as_JavaObject()), "missed JavaObject reference");
1636 }
1637 }
1638 #endif
1639 } else {
1640 // There could be initializing stores which follow allocation.
1641 // For example, a volatile field store is not collected
1642 // by Initialize node.
1643 //
1644 // Need to check for dependent loads to separate such stores from
1645 // stores which follow loads. For now, add initial value NULL so
1646 // that compare pointers optimization works correctly.
1647 }
1648 }
1649 if (value == NULL) {
1650 // A field's initializing value was not recorded. Add NULL.
1651 if (add_edge(field, null_obj)) {
1652 // New edge was added
1653 new_edges++;
1654 add_field_uses_to_worklist(field->as_Field());
1655 }
1656 }
1657 }
1658 }
1659 }
1660 return new_edges;
1661 }
1662
1663 // Adjust scalar_replaceable state after Connection Graph is built.
1664 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
1665 // Search for non-escaping objects which are not scalar replaceable
1666 // and mark them to propagate the state to referenced objects.
1667
1668 // 1. An object is not scalar replaceable if the field into which it is
1669 // stored has unknown offset (stored into unknown element of an array).
1670 //
1671 for (UseIterator i(jobj); i.has_next(); i.next()) {
1672 PointsToNode* use = i.get();
1673 if (use->is_Arraycopy()) {
1674 continue;
1675 }
1676 if (use->is_Field()) {
1677 FieldNode* field = use->as_Field();
1678 assert(field->is_oop() && field->scalar_replaceable(), "sanity");
1679 if (field->offset() == Type::OffsetBot) {
1680 jobj->set_scalar_replaceable(false);
1681 return;
1682 }
1683 // 2. An object is not scalar replaceable if the field into which it is
1684 // stored has multiple bases one of which is null.
1685 if (field->base_count() > 1) {
1686 for (BaseIterator i(field); i.has_next(); i.next()) {
1687 PointsToNode* base = i.get();
1688 if (base == null_obj) {
1689 jobj->set_scalar_replaceable(false);
1690 return;
1691 }
1692 }
1693 }
1694 }
1695 assert(use->is_Field() || use->is_LocalVar(), "sanity");
1696 // 3. An object is not scalar replaceable if it is merged with other objects.
1697 for (EdgeIterator j(use); j.has_next(); j.next()) {
1698 PointsToNode* ptn = j.get();
1699 if (ptn->is_JavaObject() && ptn != jobj) {
1700 // Mark all objects.
1701 jobj->set_scalar_replaceable(false);
1702 ptn->set_scalar_replaceable(false);
1703 }
1704 }
1705 if (!jobj->scalar_replaceable()) {
1706 return;
1707 }
1708 }
1709
1710 for (EdgeIterator j(jobj); j.has_next(); j.next()) {
1711 if (j.get()->is_Arraycopy()) {
1712 continue;
1713 }
1714
1715 // Non-escaping object node should point only to field nodes.
1716 FieldNode* field = j.get()->as_Field();
1717 int offset = field->as_Field()->offset();
1718
1719 // 4. An object is not scalar replaceable if it has a field with unknown
1720 // offset (array's element is accessed in loop).
1721 if (offset == Type::OffsetBot) {
1722 jobj->set_scalar_replaceable(false);
1723 return;
1724 }
1725 // 5. Currently an object is not scalar replaceable if a LoadStore node
1726 // access its field since the field value is unknown after it.
1727 //
1728 Node* n = field->ideal_node();
1729
1730 // Test for an unsafe access that was parsed as maybe off heap
1731 // (with a CheckCastPP to raw memory).
1732 assert(n->is_AddP(), "expect an address computation");
1733 if (n->in(AddPNode::Base)->is_top() &&
1734 n->in(AddPNode::Address)->Opcode() == Op_CheckCastPP) {
1735 assert(n->in(AddPNode::Address)->bottom_type()->isa_rawptr(), "raw address so raw cast expected");
1736 assert(_igvn->type(n->in(AddPNode::Address)->in(1))->isa_oopptr(), "cast pattern at unsafe access expected");
1737 jobj->set_scalar_replaceable(false);
1738 return;
1739 }
1740
1741 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1742 Node* u = n->fast_out(i);
1743 if (u->is_LoadStore() || (u->is_Mem() && u->as_Mem()->is_mismatched_access())) {
1744 jobj->set_scalar_replaceable(false);
1745 return;
1746 }
1747 }
1748
1749 // 6. Or the address may point to more then one object. This may produce
1750 // the false positive result (set not scalar replaceable)
1751 // since the flow-insensitive escape analysis can't separate
1752 // the case when stores overwrite the field's value from the case
1753 // when stores happened on different control branches.
1754 //
1755 // Note: it will disable scalar replacement in some cases:
1756 //
1757 // Point p[] = new Point[1];
1758 // p[0] = new Point(); // Will be not scalar replaced
1759 //
1760 // but it will save us from incorrect optimizations in next cases:
1761 //
1762 // Point p[] = new Point[1];
1763 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1764 //
1765 if (field->base_count() > 1) {
1766 for (BaseIterator i(field); i.has_next(); i.next()) {
1767 PointsToNode* base = i.get();
1768 // Don't take into account LocalVar nodes which
1769 // may point to only one object which should be also
1770 // this field's base by now.
1771 if (base->is_JavaObject() && base != jobj) {
1772 // Mark all bases.
1773 jobj->set_scalar_replaceable(false);
1774 base->set_scalar_replaceable(false);
1775 }
1776 }
1777 }
1778 }
1779 }
1780
1781 #ifdef ASSERT
1782 void ConnectionGraph::verify_connection_graph(
1783 GrowableArray<PointsToNode*>& ptnodes_worklist,
1784 GrowableArray<JavaObjectNode*>& non_escaped_worklist,
1785 GrowableArray<JavaObjectNode*>& java_objects_worklist,
1786 GrowableArray<Node*>& addp_worklist) {
1787 // Verify that graph is complete - no new edges could be added.
1788 int java_objects_length = java_objects_worklist.length();
1789 int non_escaped_length = non_escaped_worklist.length();
1790 int new_edges = 0;
1791 for (int next = 0; next < java_objects_length; ++next) {
1792 JavaObjectNode* ptn = java_objects_worklist.at(next);
1793 new_edges += add_java_object_edges(ptn, true);
1794 }
1795 assert(new_edges == 0, "graph was not complete");
1796 // Verify that escape state is final.
1797 int length = non_escaped_worklist.length();
1798 find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1799 assert((non_escaped_length == non_escaped_worklist.length()) &&
1800 (non_escaped_length == length) &&
1801 (_worklist.length() == 0), "escape state was not final");
1802
1803 // Verify fields information.
1804 int addp_length = addp_worklist.length();
1805 for (int next = 0; next < addp_length; ++next ) {
1806 Node* n = addp_worklist.at(next);
1807 FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1808 if (field->is_oop()) {
1809 // Verify that field has all bases
1810 Node* base = get_addp_base(n);
1811 PointsToNode* ptn = ptnode_adr(base->_idx);
1812 if (ptn->is_JavaObject()) {
1813 assert(field->has_base(ptn->as_JavaObject()), "sanity");
1814 } else {
1815 assert(ptn->is_LocalVar(), "sanity");
1816 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
1817 PointsToNode* e = i.get();
1818 if (e->is_JavaObject()) {
1819 assert(field->has_base(e->as_JavaObject()), "sanity");
1820 }
1821 }
1822 }
1823 // Verify that all fields have initializing values.
1824 if (field->edge_count() == 0) {
1825 tty->print_cr("----------field does not have references----------");
1826 field->dump();
1827 for (BaseIterator i(field); i.has_next(); i.next()) {
1828 PointsToNode* base = i.get();
1829 tty->print_cr("----------field has next base---------------------");
1830 base->dump();
1831 if (base->is_JavaObject() && (base != phantom_obj) && (base != null_obj)) {
1832 tty->print_cr("----------base has fields-------------------------");
1833 for (EdgeIterator j(base); j.has_next(); j.next()) {
1834 j.get()->dump();
1835 }
1836 tty->print_cr("----------base has references---------------------");
1837 for (UseIterator j(base); j.has_next(); j.next()) {
1838 j.get()->dump();
1839 }
1840 }
1841 }
1842 for (UseIterator i(field); i.has_next(); i.next()) {
1843 i.get()->dump();
1844 }
1845 assert(field->edge_count() > 0, "sanity");
1846 }
1847 }
1848 }
1849 }
1850 #endif
1851
1852 // Optimize ideal graph.
1853 void ConnectionGraph::optimize_ideal_graph(GrowableArray<Node*>& ptr_cmp_worklist,
1854 GrowableArray<Node*>& storestore_worklist) {
1855 Compile* C = _compile;
1856 PhaseIterGVN* igvn = _igvn;
1857 if (EliminateLocks) {
1858 // Mark locks before changing ideal graph.
1859 int cnt = C->macro_count();
1860 for( int i=0; i < cnt; i++ ) {
1861 Node *n = C->macro_node(i);
1862 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1863 AbstractLockNode* alock = n->as_AbstractLock();
1864 if (!alock->is_non_esc_obj()) {
1865 if (not_global_escape(alock->obj_node())) {
1866 assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1867 // The lock could be marked eliminated by lock coarsening
1868 // code during first IGVN before EA. Replace coarsened flag
1869 // to eliminate all associated locks/unlocks.
1870 #ifdef ASSERT
1871 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc3");
1872 #endif
1873 alock->set_non_esc_obj();
1874 }
1875 }
1876 }
1877 }
1878 }
1879
1880 if (OptimizePtrCompare) {
1881 // Add ConI(#CC_GT) and ConI(#CC_EQ).
1882 _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1883 _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1884 // Optimize objects compare.
1885 while (ptr_cmp_worklist.length() != 0) {
1886 Node *n = ptr_cmp_worklist.pop();
1887 Node *res = optimize_ptr_compare(n);
1888 if (res != NULL) {
1889 #ifndef PRODUCT
1890 if (PrintOptimizePtrCompare) {
1891 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"));
1892 if (Verbose) {
1893 n->dump(1);
1894 }
1895 }
1896 #endif
1897 igvn->replace_node(n, res);
1898 }
1899 }
1900 // cleanup
1901 if (_pcmp_neq->outcnt() == 0)
1902 igvn->hash_delete(_pcmp_neq);
1903 if (_pcmp_eq->outcnt() == 0)
1904 igvn->hash_delete(_pcmp_eq);
1905 }
1906
1907 // For MemBarStoreStore nodes added in library_call.cpp, check
1908 // escape status of associated AllocateNode and optimize out
1909 // MemBarStoreStore node if the allocated object never escapes.
1910 while (storestore_worklist.length() != 0) {
1911 Node *n = storestore_worklist.pop();
1912 MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1913 Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1914 assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1915 if (not_global_escape(alloc)) {
1916 MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1917 mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1918 mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1919 igvn->register_new_node_with_optimizer(mb);
1920 igvn->replace_node(storestore, mb);
1921 }
1922 }
1923 }
1924
1925 // Optimize objects compare.
1926 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
1927 assert(OptimizePtrCompare, "sanity");
1928 PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
1929 PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
1930 JavaObjectNode* jobj1 = unique_java_object(n->in(1));
1931 JavaObjectNode* jobj2 = unique_java_object(n->in(2));
1932 assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
1933 assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
1934
1935 // Check simple cases first.
1936 if (jobj1 != NULL) {
1937 if (jobj1->escape_state() == PointsToNode::NoEscape) {
1938 if (jobj1 == jobj2) {
1939 // Comparing the same not escaping object.
1940 return _pcmp_eq;
1941 }
1942 Node* obj = jobj1->ideal_node();
1943 // Comparing not escaping allocation.
1944 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1945 !ptn2->points_to(jobj1)) {
1946 return _pcmp_neq; // This includes nullness check.
1947 }
1948 }
1949 }
1950 if (jobj2 != NULL) {
1951 if (jobj2->escape_state() == PointsToNode::NoEscape) {
1952 Node* obj = jobj2->ideal_node();
1953 // Comparing not escaping allocation.
1954 if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
1955 !ptn1->points_to(jobj2)) {
1956 return _pcmp_neq; // This includes nullness check.
1957 }
1958 }
1959 }
1960 if (jobj1 != NULL && jobj1 != phantom_obj &&
1961 jobj2 != NULL && jobj2 != phantom_obj &&
1962 jobj1->ideal_node()->is_Con() &&
1963 jobj2->ideal_node()->is_Con()) {
1964 // Klass or String constants compare. Need to be careful with
1965 // compressed pointers - compare types of ConN and ConP instead of nodes.
1966 const Type* t1 = jobj1->ideal_node()->get_ptr_type();
1967 const Type* t2 = jobj2->ideal_node()->get_ptr_type();
1968 if (t1->make_ptr() == t2->make_ptr()) {
1969 return _pcmp_eq;
1970 } else {
1971 return _pcmp_neq;
1972 }
1973 }
1974 if (ptn1->meet(ptn2)) {
1975 return NULL; // Sets are not disjoint
1976 }
1977
1978 // Sets are disjoint.
1979 bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
1980 bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
1981 bool set1_has_null_ptr = ptn1->points_to(null_obj);
1982 bool set2_has_null_ptr = ptn2->points_to(null_obj);
1983 if ((set1_has_unknown_ptr && set2_has_null_ptr) ||
1984 (set2_has_unknown_ptr && set1_has_null_ptr)) {
1985 // Check nullness of unknown object.
1986 return NULL;
1987 }
1988
1989 // Disjointness by itself is not sufficient since
1990 // alias analysis is not complete for escaped objects.
1991 // Disjoint sets are definitely unrelated only when
1992 // at least one set has only not escaping allocations.
1993 if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
1994 if (ptn1->non_escaping_allocation()) {
1995 return _pcmp_neq;
1996 }
1997 }
1998 if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
1999 if (ptn2->non_escaping_allocation()) {
2000 return _pcmp_neq;
2001 }
2002 }
2003 return NULL;
2004 }
2005
2006 // Connection Graph constuction functions.
2007
2008 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
2009 PointsToNode* ptadr = _nodes.at(n->_idx);
2010 if (ptadr != NULL) {
2011 assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");
2012 return;
2013 }
2014 Compile* C = _compile;
2015 ptadr = new (C->comp_arena()) LocalVarNode(this, n, es);
2016 _nodes.at_put(n->_idx, ptadr);
2017 }
2018
2019 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
2020 PointsToNode* ptadr = _nodes.at(n->_idx);
2021 if (ptadr != NULL) {
2022 assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
2023 return;
2024 }
2025 Compile* C = _compile;
2026 ptadr = new (C->comp_arena()) JavaObjectNode(this, n, es);
2027 _nodes.at_put(n->_idx, ptadr);
2028 }
2029
2030 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
2031 PointsToNode* ptadr = _nodes.at(n->_idx);
2032 if (ptadr != NULL) {
2033 assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
2034 return;
2035 }
2036 bool unsafe = false;
2037 bool is_oop = is_oop_field(n, offset, &unsafe);
2038 if (unsafe) {
2039 es = PointsToNode::GlobalEscape;
2040 }
2041 Compile* C = _compile;
2042 FieldNode* field = new (C->comp_arena()) FieldNode(this, n, es, offset, is_oop);
2043 _nodes.at_put(n->_idx, field);
2044 }
2045
2046 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
2047 PointsToNode* src, PointsToNode* dst) {
2048 assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
2049 assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
2050 PointsToNode* ptadr = _nodes.at(n->_idx);
2051 if (ptadr != NULL) {
2052 assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
2053 return;
2054 }
2055 Compile* C = _compile;
2056 ptadr = new (C->comp_arena()) ArraycopyNode(this, n, es);
2057 _nodes.at_put(n->_idx, ptadr);
2058 // Add edge from arraycopy node to source object.
2059 (void)add_edge(ptadr, src);
2060 src->set_arraycopy_src();
2061 // Add edge from destination object to arraycopy node.
2062 (void)add_edge(dst, ptadr);
2063 dst->set_arraycopy_dst();
2064 }
2065
2066 bool ConnectionGraph::is_oop_field(Node* n, int offset, bool* unsafe) {
2067 const Type* adr_type = n->as_AddP()->bottom_type();
2068 BasicType bt = T_INT;
2069 if (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()) {
2081 ciField* field = _compile->alias_type(adr_type->isa_instptr())->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 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2090 bt = T_OBJECT;
2091 (*unsafe) = true;
2092 }
2093 }
2094 } else if (adr_type->isa_aryptr()) {
2095 if (offset == arrayOopDesc::length_offset_in_bytes()) {
2096 // Ignore array length load.
2097 } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
2098 // Ignore first AddP.
2099 } else {
2100 const Type* elemtype = adr_type->isa_aryptr()->elem();
2101 bt = elemtype->array_element_basic_type();
2102 }
2103 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
2104 // Allocation initialization, ThreadLocal field access, unsafe access
2105 if (n->has_out_with(Op_StoreP, Op_LoadP, Op_StoreN, Op_LoadN) ||
2106 n->has_out_with(Op_GetAndSetP, Op_GetAndSetN, Op_CompareAndExchangeP, Op_CompareAndExchangeN) ||
2107 n->has_out_with(Op_CompareAndSwapP, Op_CompareAndSwapN, Op_WeakCompareAndSwapP, Op_WeakCompareAndSwapN) ||
2108 BarrierSet::barrier_set()->barrier_set_c2()->escape_has_out_with_unsafe_object(n)) {
2109 bt = T_OBJECT;
2110 }
2111 }
2112 }
2113 return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
2114 }
2115
2116 // Returns unique pointed java object or NULL.
2117 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
2118 assert(!_collecting, "should not call when contructed graph");
2119 // If the node was created after the escape computation we can't answer.
2120 uint idx = n->_idx;
2121 if (idx >= nodes_size()) {
2122 return NULL;
2123 }
2124 PointsToNode* ptn = ptnode_adr(idx);
2125 if (ptn->is_JavaObject()) {
2126 return ptn->as_JavaObject();
2127 }
2128 assert(ptn->is_LocalVar(), "sanity");
2129 // Check all java objects it points to.
2130 JavaObjectNode* jobj = NULL;
2131 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2132 PointsToNode* e = i.get();
2133 if (e->is_JavaObject()) {
2134 if (jobj == NULL) {
2135 jobj = e->as_JavaObject();
2136 } else if (jobj != e) {
2137 return NULL;
2138 }
2139 }
2140 }
2141 return jobj;
2142 }
2143
2144 // Return true if this node points only to non-escaping allocations.
2145 bool PointsToNode::non_escaping_allocation() {
2146 if (is_JavaObject()) {
2147 Node* n = ideal_node();
2148 if (n->is_Allocate() || n->is_CallStaticJava()) {
2149 return (escape_state() == PointsToNode::NoEscape);
2150 } else {
2151 return false;
2152 }
2153 }
2154 assert(is_LocalVar(), "sanity");
2155 // Check all java objects it points to.
2156 for (EdgeIterator i(this); i.has_next(); i.next()) {
2157 PointsToNode* e = i.get();
2158 if (e->is_JavaObject()) {
2159 Node* n = e->ideal_node();
2160 if ((e->escape_state() != PointsToNode::NoEscape) ||
2161 !(n->is_Allocate() || n->is_CallStaticJava())) {
2162 return false;
2163 }
2164 }
2165 }
2166 return true;
2167 }
2168
2169 // Return true if we know the node does not escape globally.
2170 bool ConnectionGraph::not_global_escape(Node *n) {
2171 assert(!_collecting, "should not call during graph construction");
2172 // If the node was created after the escape computation we can't answer.
2173 uint idx = n->_idx;
2174 if (idx >= nodes_size()) {
2175 return false;
2176 }
2177 PointsToNode* ptn = ptnode_adr(idx);
2178 PointsToNode::EscapeState es = ptn->escape_state();
2179 // If we have already computed a value, return it.
2180 if (es >= PointsToNode::GlobalEscape)
2181 return false;
2182 if (ptn->is_JavaObject()) {
2183 return true; // (es < PointsToNode::GlobalEscape);
2184 }
2185 assert(ptn->is_LocalVar(), "sanity");
2186 // Check all java objects it points to.
2187 for (EdgeIterator i(ptn); i.has_next(); i.next()) {
2188 if (i.get()->escape_state() >= PointsToNode::GlobalEscape)
2189 return false;
2190 }
2191 return true;
2192 }
2193
2194
2195 // Helper functions
2196
2197 // Return true if this node points to specified node or nodes it points to.
2198 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
2199 if (is_JavaObject()) {
2200 return (this == ptn);
2201 }
2202 assert(is_LocalVar() || is_Field(), "sanity");
2203 for (EdgeIterator i(this); i.has_next(); i.next()) {
2204 if (i.get() == ptn)
2205 return true;
2206 }
2207 return false;
2208 }
2209
2210 // Return true if one node points to an other.
2211 bool PointsToNode::meet(PointsToNode* ptn) {
2212 if (this == ptn) {
2213 return true;
2214 } else if (ptn->is_JavaObject()) {
2215 return this->points_to(ptn->as_JavaObject());
2216 } else if (this->is_JavaObject()) {
2217 return ptn->points_to(this->as_JavaObject());
2218 }
2219 assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
2220 int ptn_count = ptn->edge_count();
2221 for (EdgeIterator i(this); i.has_next(); i.next()) {
2222 PointsToNode* this_e = i.get();
2223 for (int j = 0; j < ptn_count; j++) {
2224 if (this_e == ptn->edge(j))
2225 return true;
2226 }
2227 }
2228 return false;
2229 }
2230
2231 #ifdef ASSERT
2232 // Return true if bases point to this java object.
2233 bool FieldNode::has_base(JavaObjectNode* jobj) const {
2234 for (BaseIterator i(this); i.has_next(); i.next()) {
2235 if (i.get() == jobj)
2236 return true;
2237 }
2238 return false;
2239 }
2240 #endif
2241
2242 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
2243 const Type *adr_type = phase->type(adr);
2244 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
2245 adr->in(AddPNode::Address)->is_Proj() &&
2246 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2247 // We are computing a raw address for a store captured by an Initialize
2248 // compute an appropriate address type. AddP cases #3 and #5 (see below).
2249 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2250 assert(offs != Type::OffsetBot ||
2251 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
2252 "offset must be a constant or it is initialization of array");
2253 return offs;
2254 }
2255 const TypePtr *t_ptr = adr_type->isa_ptr();
2256 assert(t_ptr != NULL, "must be a pointer type");
2257 return t_ptr->offset();
2258 }
2259
2260 Node* ConnectionGraph::get_addp_base(Node *addp) {
2261 assert(addp->is_AddP(), "must be AddP");
2262 //
2263 // AddP cases for Base and Address inputs:
2264 // case #1. Direct object's field reference:
2265 // Allocate
2266 // |
2267 // Proj #5 ( oop result )
2268 // |
2269 // CheckCastPP (cast to instance type)
2270 // | |
2271 // AddP ( base == address )
2272 //
2273 // case #2. Indirect object's field reference:
2274 // Phi
2275 // |
2276 // CastPP (cast to instance type)
2277 // | |
2278 // AddP ( base == address )
2279 //
2280 // case #3. Raw object's field reference for Initialize node:
2281 // Allocate
2282 // |
2283 // Proj #5 ( oop result )
2284 // top |
2285 // \ |
2286 // AddP ( base == top )
2287 //
2288 // case #4. Array's element reference:
2289 // {CheckCastPP | CastPP}
2290 // | | |
2291 // | AddP ( array's element offset )
2292 // | |
2293 // AddP ( array's offset )
2294 //
2295 // case #5. Raw object's field reference for arraycopy stub call:
2296 // The inline_native_clone() case when the arraycopy stub is called
2297 // after the allocation before Initialize and CheckCastPP nodes.
2298 // Allocate
2299 // |
2300 // Proj #5 ( oop result )
2301 // | |
2302 // AddP ( base == address )
2303 //
2304 // case #6. Constant Pool, ThreadLocal, CastX2P or
2305 // Raw object's field reference:
2306 // {ConP, ThreadLocal, CastX2P, raw Load}
2307 // top |
2308 // \ |
2309 // AddP ( base == top )
2310 //
2311 // case #7. Klass's field reference.
2312 // LoadKlass
2313 // | |
2314 // AddP ( base == address )
2315 //
2316 // case #8. narrow Klass's field reference.
2317 // LoadNKlass
2318 // |
2319 // DecodeN
2320 // | |
2321 // AddP ( base == address )
2322 //
2323 // case #9. Mixed unsafe access
2324 // {instance}
2325 // |
2326 // CheckCastPP (raw)
2327 // top |
2328 // \ |
2329 // AddP ( base == top )
2330 //
2331 Node *base = addp->in(AddPNode::Base);
2332 if (base->uncast()->is_top()) { // The AddP case #3 and #6 and #9.
2333 base = addp->in(AddPNode::Address);
2334 while (base->is_AddP()) {
2335 // Case #6 (unsafe access) may have several chained AddP nodes.
2336 assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
2337 base = base->in(AddPNode::Address);
2338 }
2339 if (base->Opcode() == Op_CheckCastPP &&
2340 base->bottom_type()->isa_rawptr() &&
2341 _igvn->type(base->in(1))->isa_oopptr()) {
2342 base = base->in(1); // Case #9
2343 } else {
2344 Node* uncast_base = base->uncast();
2345 int opcode = uncast_base->Opcode();
2346 assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
2347 opcode == Op_CastX2P || uncast_base->is_DecodeNarrowPtr() ||
2348 (uncast_base->is_Mem() && (uncast_base->bottom_type()->isa_rawptr() != NULL)) ||
2349 (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
2350 }
2351 }
2352 return base;
2353 }
2354
2355 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
2356 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
2357 Node* addp2 = addp->raw_out(0);
2358 if (addp->outcnt() == 1 && addp2->is_AddP() &&
2359 addp2->in(AddPNode::Base) == n &&
2360 addp2->in(AddPNode::Address) == addp) {
2361 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
2362 //
2363 // Find array's offset to push it on worklist first and
2364 // as result process an array's element offset first (pushed second)
2365 // to avoid CastPP for the array's offset.
2366 // Otherwise the inserted CastPP (LocalVar) will point to what
2367 // the AddP (Field) points to. Which would be wrong since
2368 // the algorithm expects the CastPP has the same point as
2369 // as AddP's base CheckCastPP (LocalVar).
2370 //
2371 // ArrayAllocation
2372 // |
2373 // CheckCastPP
2374 // |
2375 // memProj (from ArrayAllocation CheckCastPP)
2376 // | ||
2377 // | || Int (element index)
2378 // | || | ConI (log(element size))
2379 // | || | /
2380 // | || LShift
2381 // | || /
2382 // | AddP (array's element offset)
2383 // | |
2384 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
2385 // | / /
2386 // AddP (array's offset)
2387 // |
2388 // Load/Store (memory operation on array's element)
2389 //
2390 return addp2;
2391 }
2392 return NULL;
2393 }
2394
2395 //
2396 // Adjust the type and inputs of an AddP which computes the
2397 // address of a field of an instance
2398 //
2399 bool ConnectionGraph::split_AddP(Node *addp, Node *base) {
2400 PhaseGVN* igvn = _igvn;
2401 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
2402 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
2403 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
2404 if (t == NULL) {
2405 // We are computing a raw address for a store captured by an Initialize
2406 // compute an appropriate address type (cases #3 and #5).
2407 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
2408 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
2409 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
2410 assert(offs != Type::OffsetBot, "offset must be a constant");
2411 t = base_t->add_offset(offs)->is_oopptr();
2412 }
2413 int inst_id = base_t->instance_id();
2414 assert(!t->is_known_instance() || t->instance_id() == inst_id,
2415 "old type must be non-instance or match new type");
2416
2417 // The type 't' could be subclass of 'base_t'.
2418 // As result t->offset() could be large then base_t's size and it will
2419 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
2420 // constructor verifies correctness of the offset.
2421 //
2422 // It could happened on subclass's branch (from the type profiling
2423 // inlining) which was not eliminated during parsing since the exactness
2424 // of the allocation type was not propagated to the subclass type check.
2425 //
2426 // Or the type 't' could be not related to 'base_t' at all.
2427 // It could happened when CHA type is different from MDO type on a dead path
2428 // (for example, from instanceof check) which is not collapsed during parsing.
2429 //
2430 // Do nothing for such AddP node and don't process its users since
2431 // this code branch will go away.
2432 //
2433 if (!t->is_known_instance() &&
2434 !base_t->klass()->is_subtype_of(t->klass())) {
2435 return false; // bail out
2436 }
2437 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
2438 // Do NOT remove the next line: ensure a new alias index is allocated
2439 // for the instance type. Note: C++ will not remove it since the call
2440 // has side effect.
2441 int alias_idx = _compile->get_alias_index(tinst);
2442 igvn->set_type(addp, tinst);
2443 // record the allocation in the node map
2444 set_map(addp, get_map(base->_idx));
2445 // Set addp's Base and Address to 'base'.
2446 Node *abase = addp->in(AddPNode::Base);
2447 Node *adr = addp->in(AddPNode::Address);
2448 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
2449 adr->in(0)->_idx == (uint)inst_id) {
2450 // Skip AddP cases #3 and #5.
2451 } else {
2452 assert(!abase->is_top(), "sanity"); // AddP case #3
2453 if (abase != base) {
2454 igvn->hash_delete(addp);
2455 addp->set_req(AddPNode::Base, base);
2456 if (abase == adr) {
2457 addp->set_req(AddPNode::Address, base);
2458 } else {
2459 // AddP case #4 (adr is array's element offset AddP node)
2460 #ifdef ASSERT
2461 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
2462 assert(adr->is_AddP() && atype != NULL &&
2463 atype->instance_id() == inst_id, "array's element offset should be processed first");
2464 #endif
2465 }
2466 igvn->hash_insert(addp);
2467 }
2468 }
2469 // Put on IGVN worklist since at least addp's type was changed above.
2470 record_for_optimizer(addp);
2471 return true;
2472 }
2473
2474 //
2475 // Create a new version of orig_phi if necessary. Returns either the newly
2476 // created phi or an existing phi. Sets create_new to indicate whether a new
2477 // phi was created. Cache the last newly created phi in the node map.
2478 //
2479 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, bool &new_created) {
2480 Compile *C = _compile;
2481 PhaseGVN* igvn = _igvn;
2482 new_created = false;
2483 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
2484 // nothing to do if orig_phi is bottom memory or matches alias_idx
2485 if (phi_alias_idx == alias_idx) {
2486 return orig_phi;
2487 }
2488 // Have we recently created a Phi for this alias index?
2489 PhiNode *result = get_map_phi(orig_phi->_idx);
2490 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
2491 return result;
2492 }
2493 // Previous check may fail when the same wide memory Phi was split into Phis
2494 // for different memory slices. Search all Phis for this region.
2495 if (result != NULL) {
2496 Node* region = orig_phi->in(0);
2497 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
2498 Node* phi = region->fast_out(i);
2499 if (phi->is_Phi() &&
2500 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
2501 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
2502 return phi->as_Phi();
2503 }
2504 }
2505 }
2506 if (C->live_nodes() + 2*NodeLimitFudgeFactor > C->max_node_limit()) {
2507 if (C->do_escape_analysis() == true && !C->failing()) {
2508 // Retry compilation without escape analysis.
2509 // If this is the first failure, the sentinel string will "stick"
2510 // to the Compile object, and the C2Compiler will see it and retry.
2511 C->record_failure(C2Compiler::retry_no_escape_analysis());
2512 }
2513 return NULL;
2514 }
2515 orig_phi_worklist.append_if_missing(orig_phi);
2516 const TypePtr *atype = C->get_adr_type(alias_idx);
2517 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
2518 C->copy_node_notes_to(result, orig_phi);
2519 igvn->set_type(result, result->bottom_type());
2520 record_for_optimizer(result);
2521 set_map(orig_phi, result);
2522 new_created = true;
2523 return result;
2524 }
2525
2526 //
2527 // Return a new version of Memory Phi "orig_phi" with the inputs having the
2528 // specified alias index.
2529 //
2530 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist) {
2531 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
2532 Compile *C = _compile;
2533 PhaseGVN* igvn = _igvn;
2534 bool new_phi_created;
2535 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, new_phi_created);
2536 if (!new_phi_created) {
2537 return result;
2538 }
2539 GrowableArray<PhiNode *> phi_list;
2540 GrowableArray<uint> cur_input;
2541 PhiNode *phi = orig_phi;
2542 uint idx = 1;
2543 bool finished = false;
2544 while(!finished) {
2545 while (idx < phi->req()) {
2546 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist);
2547 if (mem != NULL && mem->is_Phi()) {
2548 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, new_phi_created);
2549 if (new_phi_created) {
2550 // found an phi for which we created a new split, push current one on worklist and begin
2551 // processing new one
2552 phi_list.push(phi);
2553 cur_input.push(idx);
2554 phi = mem->as_Phi();
2555 result = newphi;
2556 idx = 1;
2557 continue;
2558 } else {
2559 mem = newphi;
2560 }
2561 }
2562 if (C->failing()) {
2563 return NULL;
2564 }
2565 result->set_req(idx++, mem);
2566 }
2567 #ifdef ASSERT
2568 // verify that the new Phi has an input for each input of the original
2569 assert( phi->req() == result->req(), "must have same number of inputs.");
2570 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
2571 #endif
2572 // Check if all new phi's inputs have specified alias index.
2573 // Otherwise use old phi.
2574 for (uint i = 1; i < phi->req(); i++) {
2575 Node* in = result->in(i);
2576 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
2577 }
2578 // we have finished processing a Phi, see if there are any more to do
2579 finished = (phi_list.length() == 0 );
2580 if (!finished) {
2581 phi = phi_list.pop();
2582 idx = cur_input.pop();
2583 PhiNode *prev_result = get_map_phi(phi->_idx);
2584 prev_result->set_req(idx++, result);
2585 result = prev_result;
2586 }
2587 }
2588 return result;
2589 }
2590
2591 //
2592 // The next methods are derived from methods in MemNode.
2593 //
2594 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
2595 Node *mem = mmem;
2596 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
2597 // means an array I have not precisely typed yet. Do not do any
2598 // alias stuff with it any time soon.
2599 if (toop->base() != Type::AnyPtr &&
2600 !(toop->klass() != NULL &&
2601 toop->klass()->is_java_lang_Object() &&
2602 toop->offset() == Type::OffsetBot)) {
2603 mem = mmem->memory_at(alias_idx);
2604 // Update input if it is progress over what we have now
2605 }
2606 return mem;
2607 }
2608
2609 //
2610 // Move memory users to their memory slices.
2611 //
2612 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis) {
2613 Compile* C = _compile;
2614 PhaseGVN* igvn = _igvn;
2615 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
2616 assert(tp != NULL, "ptr type");
2617 int alias_idx = C->get_alias_index(tp);
2618 int general_idx = C->get_general_index(alias_idx);
2619
2620 // Move users first
2621 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2622 Node* use = n->fast_out(i);
2623 if (use->is_MergeMem()) {
2624 MergeMemNode* mmem = use->as_MergeMem();
2625 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
2626 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
2627 continue; // Nothing to do
2628 }
2629 // Replace previous general reference to mem node.
2630 uint orig_uniq = C->unique();
2631 Node* m = find_inst_mem(n, general_idx, orig_phis);
2632 assert(orig_uniq == C->unique(), "no new nodes");
2633 mmem->set_memory_at(general_idx, m);
2634 --imax;
2635 --i;
2636 } else if (use->is_MemBar()) {
2637 assert(!use->is_Initialize(), "initializing stores should not be moved");
2638 if (use->req() > MemBarNode::Precedent &&
2639 use->in(MemBarNode::Precedent) == n) {
2640 // Don't move related membars.
2641 record_for_optimizer(use);
2642 continue;
2643 }
2644 tp = use->as_MemBar()->adr_type()->isa_ptr();
2645 if ((tp != NULL && C->get_alias_index(tp) == alias_idx) ||
2646 alias_idx == general_idx) {
2647 continue; // Nothing to do
2648 }
2649 // Move to general memory slice.
2650 uint orig_uniq = C->unique();
2651 Node* m = find_inst_mem(n, general_idx, orig_phis);
2652 assert(orig_uniq == C->unique(), "no new nodes");
2653 igvn->hash_delete(use);
2654 imax -= use->replace_edge(n, m);
2655 igvn->hash_insert(use);
2656 record_for_optimizer(use);
2657 --i;
2658 #ifdef ASSERT
2659 } else if (use->is_Mem()) {
2660 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
2661 // Don't move related cardmark.
2662 continue;
2663 }
2664 // Memory nodes should have new memory input.
2665 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
2666 assert(tp != NULL, "ptr type");
2667 int idx = C->get_alias_index(tp);
2668 assert(get_map(use->_idx) != NULL || idx == alias_idx,
2669 "Following memory nodes should have new memory input or be on the same memory slice");
2670 } else if (use->is_Phi()) {
2671 // Phi nodes should be split and moved already.
2672 tp = use->as_Phi()->adr_type()->isa_ptr();
2673 assert(tp != NULL, "ptr type");
2674 int idx = C->get_alias_index(tp);
2675 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
2676 } else {
2677 use->dump();
2678 assert(false, "should not be here");
2679 #endif
2680 }
2681 }
2682 }
2683
2684 //
2685 // Search memory chain of "mem" to find a MemNode whose address
2686 // is the specified alias index.
2687 //
2688 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis) {
2689 if (orig_mem == NULL)
2690 return orig_mem;
2691 Compile* C = _compile;
2692 PhaseGVN* igvn = _igvn;
2693 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
2694 bool is_instance = (toop != NULL) && toop->is_known_instance();
2695 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
2696 Node *prev = NULL;
2697 Node *result = orig_mem;
2698 while (prev != result) {
2699 prev = result;
2700 if (result == start_mem)
2701 break; // hit one of our sentinels
2702 if (result->is_Mem()) {
2703 const Type *at = igvn->type(result->in(MemNode::Address));
2704 if (at == Type::TOP)
2705 break; // Dead
2706 assert (at->isa_ptr() != NULL, "pointer type required.");
2707 int idx = C->get_alias_index(at->is_ptr());
2708 if (idx == alias_idx)
2709 break; // Found
2710 if (!is_instance && (at->isa_oopptr() == NULL ||
2711 !at->is_oopptr()->is_known_instance())) {
2712 break; // Do not skip store to general memory slice.
2713 }
2714 result = result->in(MemNode::Memory);
2715 }
2716 if (!is_instance)
2717 continue; // don't search further for non-instance types
2718 // skip over a call which does not affect this memory slice
2719 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
2720 Node *proj_in = result->in(0);
2721 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
2722 break; // hit one of our sentinels
2723 } else if (proj_in->is_Call()) {
2724 // ArrayCopy node processed here as well
2725 CallNode *call = proj_in->as_Call();
2726 if (!call->may_modify(toop, igvn)) {
2727 result = call->in(TypeFunc::Memory);
2728 }
2729 } else if (proj_in->is_Initialize()) {
2730 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
2731 // Stop if this is the initialization for the object instance which
2732 // which contains this memory slice, otherwise skip over it.
2733 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
2734 result = proj_in->in(TypeFunc::Memory);
2735 }
2736 } else if (proj_in->is_MemBar()) {
2737 if (proj_in->in(TypeFunc::Memory)->is_MergeMem() &&
2738 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->is_Proj() &&
2739 proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->is_ArrayCopy()) {
2740 // clone
2741 ArrayCopyNode* ac = proj_in->in(TypeFunc::Memory)->as_MergeMem()->in(Compile::AliasIdxRaw)->in(0)->as_ArrayCopy();
2742 if (ac->may_modify(toop, igvn)) {
2743 break;
2744 }
2745 }
2746 result = proj_in->in(TypeFunc::Memory);
2747 }
2748 } else if (result->is_MergeMem()) {
2749 MergeMemNode *mmem = result->as_MergeMem();
2750 result = step_through_mergemem(mmem, alias_idx, toop);
2751 if (result == mmem->base_memory()) {
2752 // Didn't find instance memory, search through general slice recursively.
2753 result = mmem->memory_at(C->get_general_index(alias_idx));
2754 result = find_inst_mem(result, alias_idx, orig_phis);
2755 if (C->failing()) {
2756 return NULL;
2757 }
2758 mmem->set_memory_at(alias_idx, result);
2759 }
2760 } else if (result->is_Phi() &&
2761 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
2762 Node *un = result->as_Phi()->unique_input(igvn);
2763 if (un != NULL) {
2764 orig_phis.append_if_missing(result->as_Phi());
2765 result = un;
2766 } else {
2767 break;
2768 }
2769 } else if (result->is_ClearArray()) {
2770 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), igvn)) {
2771 // Can not bypass initialization of the instance
2772 // we are looking for.
2773 break;
2774 }
2775 // Otherwise skip it (the call updated 'result' value).
2776 } else if (result->Opcode() == Op_SCMemProj) {
2777 Node* mem = result->in(0);
2778 Node* adr = NULL;
2779 if (mem->is_LoadStore()) {
2780 adr = mem->in(MemNode::Address);
2781 } else {
2782 assert(mem->Opcode() == Op_EncodeISOArray ||
2783 mem->Opcode() == Op_StrCompressedCopy, "sanity");
2784 adr = mem->in(3); // Memory edge corresponds to destination array
2785 }
2786 const Type *at = igvn->type(adr);
2787 if (at != Type::TOP) {
2788 assert(at->isa_ptr() != NULL, "pointer type required.");
2789 int idx = C->get_alias_index(at->is_ptr());
2790 if (idx == alias_idx) {
2791 // Assert in debug mode
2792 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
2793 break; // In product mode return SCMemProj node
2794 }
2795 }
2796 result = mem->in(MemNode::Memory);
2797 } else if (result->Opcode() == Op_StrInflatedCopy) {
2798 Node* adr = result->in(3); // Memory edge corresponds to destination array
2799 const Type *at = igvn->type(adr);
2800 if (at != Type::TOP) {
2801 assert(at->isa_ptr() != NULL, "pointer type required.");
2802 int idx = C->get_alias_index(at->is_ptr());
2803 if (idx == alias_idx) {
2804 // Assert in debug mode
2805 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
2806 break; // In product mode return SCMemProj node
2807 }
2808 }
2809 result = result->in(MemNode::Memory);
2810 }
2811 }
2812 if (result->is_Phi()) {
2813 PhiNode *mphi = result->as_Phi();
2814 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
2815 const TypePtr *t = mphi->adr_type();
2816 if (!is_instance) {
2817 // Push all non-instance Phis on the orig_phis worklist to update inputs
2818 // during Phase 4 if needed.
2819 orig_phis.append_if_missing(mphi);
2820 } else if (C->get_alias_index(t) != alias_idx) {
2821 // Create a new Phi with the specified alias index type.
2822 result = split_memory_phi(mphi, alias_idx, orig_phis);
2823 }
2824 }
2825 // the result is either MemNode, PhiNode, InitializeNode.
2826 return result;
2827 }
2828
2829 //
2830 // Convert the types of unescaped object to instance types where possible,
2831 // propagate the new type information through the graph, and update memory
2832 // edges and MergeMem inputs to reflect the new type.
2833 //
2834 // We start with allocations (and calls which may be allocations) on alloc_worklist.
2835 // The processing is done in 4 phases:
2836 //
2837 // Phase 1: Process possible allocations from alloc_worklist. Create instance
2838 // types for the CheckCastPP for allocations where possible.
2839 // Propagate the new types through users as follows:
2840 // casts and Phi: push users on alloc_worklist
2841 // AddP: cast Base and Address inputs to the instance type
2842 // push any AddP users on alloc_worklist and push any memnode
2843 // users onto memnode_worklist.
2844 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
2845 // search the Memory chain for a store with the appropriate type
2846 // address type. If a Phi is found, create a new version with
2847 // the appropriate memory slices from each of the Phi inputs.
2848 // For stores, process the users as follows:
2849 // MemNode: push on memnode_worklist
2850 // MergeMem: push on mergemem_worklist
2851 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
2852 // moving the first node encountered of each instance type to the
2853 // the input corresponding to its alias index.
2854 // appropriate memory slice.
2855 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
2856 //
2857 // In the following example, the CheckCastPP nodes are the cast of allocation
2858 // results and the allocation of node 29 is unescaped and eligible to be an
2859 // instance type.
2860 //
2861 // We start with:
2862 //
2863 // 7 Parm #memory
2864 // 10 ConI "12"
2865 // 19 CheckCastPP "Foo"
2866 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2867 // 29 CheckCastPP "Foo"
2868 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
2869 //
2870 // 40 StoreP 25 7 20 ... alias_index=4
2871 // 50 StoreP 35 40 30 ... alias_index=4
2872 // 60 StoreP 45 50 20 ... alias_index=4
2873 // 70 LoadP _ 60 30 ... alias_index=4
2874 // 80 Phi 75 50 60 Memory alias_index=4
2875 // 90 LoadP _ 80 30 ... alias_index=4
2876 // 100 LoadP _ 80 20 ... alias_index=4
2877 //
2878 //
2879 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
2880 // and creating a new alias index for node 30. This gives:
2881 //
2882 // 7 Parm #memory
2883 // 10 ConI "12"
2884 // 19 CheckCastPP "Foo"
2885 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2886 // 29 CheckCastPP "Foo" iid=24
2887 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2888 //
2889 // 40 StoreP 25 7 20 ... alias_index=4
2890 // 50 StoreP 35 40 30 ... alias_index=6
2891 // 60 StoreP 45 50 20 ... alias_index=4
2892 // 70 LoadP _ 60 30 ... alias_index=6
2893 // 80 Phi 75 50 60 Memory alias_index=4
2894 // 90 LoadP _ 80 30 ... alias_index=6
2895 // 100 LoadP _ 80 20 ... alias_index=4
2896 //
2897 // In phase 2, new memory inputs are computed for the loads and stores,
2898 // And a new version of the phi is created. In phase 4, the inputs to
2899 // node 80 are updated and then the memory nodes are updated with the
2900 // values computed in phase 2. This results in:
2901 //
2902 // 7 Parm #memory
2903 // 10 ConI "12"
2904 // 19 CheckCastPP "Foo"
2905 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
2906 // 29 CheckCastPP "Foo" iid=24
2907 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
2908 //
2909 // 40 StoreP 25 7 20 ... alias_index=4
2910 // 50 StoreP 35 7 30 ... alias_index=6
2911 // 60 StoreP 45 40 20 ... alias_index=4
2912 // 70 LoadP _ 50 30 ... alias_index=6
2913 // 80 Phi 75 40 60 Memory alias_index=4
2914 // 120 Phi 75 50 50 Memory alias_index=6
2915 // 90 LoadP _ 120 30 ... alias_index=6
2916 // 100 LoadP _ 80 20 ... alias_index=4
2917 //
2918 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist, GrowableArray<ArrayCopyNode*> &arraycopy_worklist) {
2919 GrowableArray<Node *> memnode_worklist;
2920 GrowableArray<PhiNode *> orig_phis;
2921 PhaseIterGVN *igvn = _igvn;
2922 uint new_index_start = (uint) _compile->num_alias_types();
2923 Arena* arena = Thread::current()->resource_area();
2924 VectorSet visited(arena);
2925 ideal_nodes.clear(); // Reset for use with set_map/get_map.
2926 uint unique_old = _compile->unique();
2927
2928 // Phase 1: Process possible allocations from alloc_worklist.
2929 // Create instance types for the CheckCastPP for allocations where possible.
2930 //
2931 // (Note: don't forget to change the order of the second AddP node on
2932 // the alloc_worklist if the order of the worklist processing is changed,
2933 // see the comment in find_second_addp().)
2934 //
2935 while (alloc_worklist.length() != 0) {
2936 Node *n = alloc_worklist.pop();
2937 uint ni = n->_idx;
2938 if (n->is_Call()) {
2939 CallNode *alloc = n->as_Call();
2940 // copy escape information to call node
2941 PointsToNode* ptn = ptnode_adr(alloc->_idx);
2942 PointsToNode::EscapeState es = ptn->escape_state();
2943 // We have an allocation or call which returns a Java object,
2944 // see if it is unescaped.
2945 if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
2946 continue;
2947 // Find CheckCastPP for the allocate or for the return value of a call
2948 n = alloc->result_cast();
2949 if (n == NULL) { // No uses except Initialize node
2950 if (alloc->is_Allocate()) {
2951 // Set the scalar_replaceable flag for allocation
2952 // so it could be eliminated if it has no uses.
2953 alloc->as_Allocate()->_is_scalar_replaceable = true;
2954 }
2955 if (alloc->is_CallStaticJava()) {
2956 // Set the scalar_replaceable flag for boxing method
2957 // so it could be eliminated if it has no uses.
2958 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
2959 }
2960 continue;
2961 }
2962 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
2963 assert(!alloc->is_Allocate(), "allocation should have unique type");
2964 continue;
2965 }
2966
2967 // The inline code for Object.clone() casts the allocation result to
2968 // java.lang.Object and then to the actual type of the allocated
2969 // object. Detect this case and use the second cast.
2970 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
2971 // the allocation result is cast to java.lang.Object and then
2972 // to the actual Array type.
2973 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
2974 && (alloc->is_AllocateArray() ||
2975 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
2976 Node *cast2 = NULL;
2977 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2978 Node *use = n->fast_out(i);
2979 if (use->is_CheckCastPP()) {
2980 cast2 = use;
2981 break;
2982 }
2983 }
2984 if (cast2 != NULL) {
2985 n = cast2;
2986 } else {
2987 // Non-scalar replaceable if the allocation type is unknown statically
2988 // (reflection allocation), the object can't be restored during
2989 // deoptimization without precise type.
2990 continue;
2991 }
2992 }
2993
2994 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
2995 if (t == NULL)
2996 continue; // not a TypeOopPtr
2997 if (!t->klass_is_exact())
2998 continue; // not an unique type
2999
3000 if (alloc->is_Allocate()) {
3001 // Set the scalar_replaceable flag for allocation
3002 // so it could be eliminated.
3003 alloc->as_Allocate()->_is_scalar_replaceable = true;
3004 }
3005 if (alloc->is_CallStaticJava()) {
3006 // Set the scalar_replaceable flag for boxing method
3007 // so it could be eliminated.
3008 alloc->as_CallStaticJava()->_is_scalar_replaceable = true;
3009 }
3010 set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
3011 // in order for an object to be scalar-replaceable, it must be:
3012 // - a direct allocation (not a call returning an object)
3013 // - non-escaping
3014 // - eligible to be a unique type
3015 // - not determined to be ineligible by escape analysis
3016 set_map(alloc, n);
3017 set_map(n, alloc);
3018 const TypeOopPtr* tinst = t->cast_to_instance_id(ni);
3019 igvn->hash_delete(n);
3020 igvn->set_type(n, tinst);
3021 n->raise_bottom_type(tinst);
3022 igvn->hash_insert(n);
3023 record_for_optimizer(n);
3024 // Allocate an alias index for the header fields. Accesses to
3025 // the header emitted during macro expansion wouldn't have
3026 // correct memory state otherwise.
3027 _compile->get_alias_index(tinst->add_offset(oopDesc::mark_offset_in_bytes()));
3028 _compile->get_alias_index(tinst->add_offset(oopDesc::klass_offset_in_bytes()));
3029 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
3030
3031 // First, put on the worklist all Field edges from Connection Graph
3032 // which is more accurate than putting immediate users from Ideal Graph.
3033 for (EdgeIterator e(ptn); e.has_next(); e.next()) {
3034 PointsToNode* tgt = e.get();
3035 if (tgt->is_Arraycopy()) {
3036 continue;
3037 }
3038 Node* use = tgt->ideal_node();
3039 assert(tgt->is_Field() && use->is_AddP(),
3040 "only AddP nodes are Field edges in CG");
3041 if (use->outcnt() > 0) { // Don't process dead nodes
3042 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
3043 if (addp2 != NULL) {
3044 assert(alloc->is_AllocateArray(),"array allocation was expected");
3045 alloc_worklist.append_if_missing(addp2);
3046 }
3047 alloc_worklist.append_if_missing(use);
3048 }
3049 }
3050
3051 // An allocation may have an Initialize which has raw stores. Scan
3052 // the users of the raw allocation result and push AddP users
3053 // on alloc_worklist.
3054 Node *raw_result = alloc->proj_out_or_null(TypeFunc::Parms);
3055 assert (raw_result != NULL, "must have an allocation result");
3056 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
3057 Node *use = raw_result->fast_out(i);
3058 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
3059 Node* addp2 = find_second_addp(use, raw_result);
3060 if (addp2 != NULL) {
3061 assert(alloc->is_AllocateArray(),"array allocation was expected");
3062 alloc_worklist.append_if_missing(addp2);
3063 }
3064 alloc_worklist.append_if_missing(use);
3065 } else if (use->is_MemBar()) {
3066 memnode_worklist.append_if_missing(use);
3067 }
3068 }
3069 }
3070 } else if (n->is_AddP()) {
3071 JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
3072 if (jobj == NULL || jobj == phantom_obj) {
3073 #ifdef ASSERT
3074 ptnode_adr(get_addp_base(n)->_idx)->dump();
3075 ptnode_adr(n->_idx)->dump();
3076 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3077 #endif
3078 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3079 return;
3080 }
3081 Node *base = get_map(jobj->idx()); // CheckCastPP node
3082 if (!split_AddP(n, base)) continue; // wrong type from dead path
3083 } else if (n->is_Phi() ||
3084 n->is_CheckCastPP() ||
3085 n->is_EncodeP() ||
3086 n->is_DecodeN() ||
3087 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
3088 if (visited.test_set(n->_idx)) {
3089 assert(n->is_Phi(), "loops only through Phi's");
3090 continue; // already processed
3091 }
3092 JavaObjectNode* jobj = unique_java_object(n);
3093 if (jobj == NULL || jobj == phantom_obj) {
3094 #ifdef ASSERT
3095 ptnode_adr(n->_idx)->dump();
3096 assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
3097 #endif
3098 _compile->record_failure(C2Compiler::retry_no_escape_analysis());
3099 return;
3100 } else {
3101 Node *val = get_map(jobj->idx()); // CheckCastPP node
3102 TypeNode *tn = n->as_Type();
3103 const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
3104 assert(tinst != NULL && tinst->is_known_instance() &&
3105 tinst->instance_id() == jobj->idx() , "instance type expected.");
3106
3107 const Type *tn_type = igvn->type(tn);
3108 const TypeOopPtr *tn_t;
3109 if (tn_type->isa_narrowoop()) {
3110 tn_t = tn_type->make_ptr()->isa_oopptr();
3111 } else {
3112 tn_t = tn_type->isa_oopptr();
3113 }
3114 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
3115 if (tn_type->isa_narrowoop()) {
3116 tn_type = tinst->make_narrowoop();
3117 } else {
3118 tn_type = tinst;
3119 }
3120 igvn->hash_delete(tn);
3121 igvn->set_type(tn, tn_type);
3122 tn->set_type(tn_type);
3123 igvn->hash_insert(tn);
3124 record_for_optimizer(n);
3125 } else {
3126 assert(tn_type == TypePtr::NULL_PTR ||
3127 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
3128 "unexpected type");
3129 continue; // Skip dead path with different type
3130 }
3131 }
3132 } else {
3133 debug_only(n->dump();)
3134 assert(false, "EA: unexpected node");
3135 continue;
3136 }
3137 // push allocation's users on appropriate worklist
3138 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3139 Node *use = n->fast_out(i);
3140 if(use->is_Mem() && use->in(MemNode::Address) == n) {
3141 // Load/store to instance's field
3142 memnode_worklist.append_if_missing(use);
3143 } else if (use->is_MemBar()) {
3144 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3145 memnode_worklist.append_if_missing(use);
3146 }
3147 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
3148 Node* addp2 = find_second_addp(use, n);
3149 if (addp2 != NULL) {
3150 alloc_worklist.append_if_missing(addp2);
3151 }
3152 alloc_worklist.append_if_missing(use);
3153 } else if (use->is_Phi() ||
3154 use->is_CheckCastPP() ||
3155 use->is_EncodeNarrowPtr() ||
3156 use->is_DecodeNarrowPtr() ||
3157 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
3158 alloc_worklist.append_if_missing(use);
3159 #ifdef ASSERT
3160 } else if (use->is_Mem()) {
3161 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
3162 } else if (use->is_MergeMem()) {
3163 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3164 } else if (use->is_SafePoint()) {
3165 // Look for MergeMem nodes for calls which reference unique allocation
3166 // (through CheckCastPP nodes) even for debug info.
3167 Node* m = use->in(TypeFunc::Memory);
3168 if (m->is_MergeMem()) {
3169 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3170 }
3171 } else if (use->Opcode() == Op_EncodeISOArray) {
3172 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3173 // EncodeISOArray overwrites destination array
3174 memnode_worklist.append_if_missing(use);
3175 }
3176 } else {
3177 uint op = use->Opcode();
3178 if ((op == Op_StrCompressedCopy || op == Op_StrInflatedCopy) &&
3179 (use->in(MemNode::Memory) == n)) {
3180 // They overwrite memory edge corresponding to destination array,
3181 memnode_worklist.append_if_missing(use);
3182 } else if (!(op == Op_CmpP || op == Op_Conv2B ||
3183 op == Op_CastP2X || op == Op_StoreCM ||
3184 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp || op == Op_HasNegatives ||
3185 op == Op_StrCompressedCopy || op == Op_StrInflatedCopy ||
3186 op == Op_StrEquals || op == Op_StrIndexOf || op == Op_StrIndexOfChar ||
3187 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use))) {
3188 n->dump();
3189 use->dump();
3190 assert(false, "EA: missing allocation reference path");
3191 }
3192 #endif
3193 }
3194 }
3195
3196 }
3197
3198 // Go over all ArrayCopy nodes and if one of the inputs has a unique
3199 // type, record it in the ArrayCopy node so we know what memory this
3200 // node uses/modified.
3201 for (int next = 0; next < arraycopy_worklist.length(); next++) {
3202 ArrayCopyNode* ac = arraycopy_worklist.at(next);
3203 Node* dest = ac->in(ArrayCopyNode::Dest);
3204 if (dest->is_AddP()) {
3205 dest = get_addp_base(dest);
3206 }
3207 JavaObjectNode* jobj = unique_java_object(dest);
3208 if (jobj != NULL) {
3209 Node *base = get_map(jobj->idx());
3210 if (base != NULL) {
3211 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3212 ac->_dest_type = base_t;
3213 }
3214 }
3215 Node* src = ac->in(ArrayCopyNode::Src);
3216 if (src->is_AddP()) {
3217 src = get_addp_base(src);
3218 }
3219 jobj = unique_java_object(src);
3220 if (jobj != NULL) {
3221 Node* base = get_map(jobj->idx());
3222 if (base != NULL) {
3223 const TypeOopPtr *base_t = _igvn->type(base)->isa_oopptr();
3224 ac->_src_type = base_t;
3225 }
3226 }
3227 }
3228
3229 // New alias types were created in split_AddP().
3230 uint new_index_end = (uint) _compile->num_alias_types();
3231 assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
3232
3233 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
3234 // compute new values for Memory inputs (the Memory inputs are not
3235 // actually updated until phase 4.)
3236 if (memnode_worklist.length() == 0)
3237 return; // nothing to do
3238 while (memnode_worklist.length() != 0) {
3239 Node *n = memnode_worklist.pop();
3240 if (visited.test_set(n->_idx))
3241 continue;
3242 if (n->is_Phi() || n->is_ClearArray()) {
3243 // we don't need to do anything, but the users must be pushed
3244 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
3245 // we don't need to do anything, but the users must be pushed
3246 n = n->as_MemBar()->proj_out_or_null(TypeFunc::Memory);
3247 if (n == NULL)
3248 continue;
3249 } else if (n->Opcode() == Op_StrCompressedCopy ||
3250 n->Opcode() == Op_EncodeISOArray) {
3251 // get the memory projection
3252 n = n->find_out_with(Op_SCMemProj);
3253 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3254 } else {
3255 assert(n->is_Mem(), "memory node required.");
3256 Node *addr = n->in(MemNode::Address);
3257 const Type *addr_t = igvn->type(addr);
3258 if (addr_t == Type::TOP)
3259 continue;
3260 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
3261 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
3262 assert ((uint)alias_idx < new_index_end, "wrong alias index");
3263 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis);
3264 if (_compile->failing()) {
3265 return;
3266 }
3267 if (mem != n->in(MemNode::Memory)) {
3268 // We delay the memory edge update since we need old one in
3269 // MergeMem code below when instances memory slices are separated.
3270 set_map(n, mem);
3271 }
3272 if (n->is_Load()) {
3273 continue; // don't push users
3274 } else if (n->is_LoadStore()) {
3275 // get the memory projection
3276 n = n->find_out_with(Op_SCMemProj);
3277 assert(n != NULL && n->Opcode() == Op_SCMemProj, "memory projection required");
3278 }
3279 }
3280 // push user on appropriate worklist
3281 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
3282 Node *use = n->fast_out(i);
3283 if (use->is_Phi() || use->is_ClearArray()) {
3284 memnode_worklist.append_if_missing(use);
3285 } else if (use->is_Mem() && use->in(MemNode::Memory) == n) {
3286 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
3287 continue;
3288 memnode_worklist.append_if_missing(use);
3289 } else if (use->is_MemBar()) {
3290 if (use->in(TypeFunc::Memory) == n) { // Ignore precedent edge
3291 memnode_worklist.append_if_missing(use);
3292 }
3293 #ifdef ASSERT
3294 } else if(use->is_Mem()) {
3295 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
3296 } else if (use->is_MergeMem()) {
3297 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
3298 } else if (use->Opcode() == Op_EncodeISOArray) {
3299 if (use->in(MemNode::Memory) == n || use->in(3) == n) {
3300 // EncodeISOArray overwrites destination array
3301 memnode_worklist.append_if_missing(use);
3302 }
3303 } else {
3304 uint op = use->Opcode();
3305 if ((use->in(MemNode::Memory) == n) &&
3306 (op == Op_StrCompressedCopy || op == Op_StrInflatedCopy)) {
3307 // They overwrite memory edge corresponding to destination array,
3308 memnode_worklist.append_if_missing(use);
3309 } else if (!(BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(use) ||
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 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 encounted 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
3559
3560 void ConnectionGraph::record_for_optimizer(Node *n) {
3561 _igvn->_worklist.push(n);
3562 _igvn->add_users_to_worklist(n);
3563 }