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