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