1 /*
2 * Copyright (c) 2005, 2011, 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 "libadt/vectset.hpp"
28 #include "memory/allocation.hpp"
29 #include "opto/c2compiler.hpp"
30 #include "opto/callnode.hpp"
31 #include "opto/cfgnode.hpp"
32 #include "opto/compile.hpp"
33 #include "opto/escape.hpp"
34 #include "opto/phaseX.hpp"
35 #include "opto/rootnode.hpp"
36
37 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
38 uint v = (targIdx << EdgeShift) + ((uint) et);
39 if (_edges == NULL) {
40 Arena *a = Compile::current()->comp_arena();
41 _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
42 }
43 _edges->append_if_missing(v);
44 }
45
46 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
47 uint v = (targIdx << EdgeShift) + ((uint) et);
48
49 _edges->remove(v);
50 }
51
52 #ifndef PRODUCT
53 static const char *node_type_names[] = {
54 "UnknownType",
55 "JavaObject",
56 "LocalVar",
57 "Field"
58 };
59
60 static const char *esc_names[] = {
61 "UnknownEscape",
62 "NoEscape",
63 "ControlEscape",
64 "ArgEscape",
65 "GlobalEscape"
66 };
67
68 static const char *edge_type_suffix[] = {
69 "?", // UnknownEdge
70 "P", // PointsToEdge
71 "D", // DeferredEdge
72 "F" // FieldEdge
73 };
74
75 void PointsToNode::dump(bool print_state) const {
76 NodeType nt = node_type();
77 tty->print("%s ", node_type_names[(int) nt]);
78 if (print_state) {
79 EscapeState es = escape_state();
80 tty->print("%s ", esc_names[(int) es]);
81 }
82 tty->print("[[");
83 for (uint i = 0; i < edge_count(); i++) {
84 tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
85 }
86 tty->print("]] ");
87 if (_node == NULL)
88 tty->print_cr("<null>");
89 else
90 _node->dump();
91 }
92 #endif
93
94 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
95 _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
96 _processed(C->comp_arena()),
97 pt_ptset(C->comp_arena()),
98 pt_visited(C->comp_arena()),
99 pt_worklist(C->comp_arena(), 4, 0, 0),
100 _collecting(true),
101 _progress(false),
102 _compile(C),
103 _igvn(igvn),
104 _node_map(C->comp_arena()) {
105
106 _phantom_object = C->top()->_idx,
107 add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
108
109 // Add ConP(#NULL) and ConN(#NULL) nodes.
110 Node* oop_null = igvn->zerocon(T_OBJECT);
111 _oop_null = oop_null->_idx;
112 assert(_oop_null < nodes_size(), "should be created already");
113 add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
114
115 if (UseCompressedOops) {
116 Node* noop_null = igvn->zerocon(T_NARROWOOP);
117 _noop_null = noop_null->_idx;
118 assert(_noop_null < nodes_size(), "should be created already");
119 add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
120 } else {
121 _noop_null = _oop_null; // Should be initialized
122 }
123 }
124
125 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
126 PointsToNode *f = ptnode_adr(from_i);
127 PointsToNode *t = ptnode_adr(to_i);
128
129 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
130 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
131 assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
132 add_edge(f, to_i, PointsToNode::PointsToEdge);
133 }
134
135 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
136 PointsToNode *f = ptnode_adr(from_i);
137 PointsToNode *t = ptnode_adr(to_i);
138
139 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
140 assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
141 assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
142 // don't add a self-referential edge, this can occur during removal of
143 // deferred edges
144 if (from_i != to_i)
145 add_edge(f, to_i, PointsToNode::DeferredEdge);
146 }
147
148 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
149 const Type *adr_type = phase->type(adr);
150 if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
151 adr->in(AddPNode::Address)->is_Proj() &&
152 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
153 // We are computing a raw address for a store captured by an Initialize
154 // compute an appropriate address type. AddP cases #3 and #5 (see below).
155 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
156 assert(offs != Type::OffsetBot ||
157 adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
158 "offset must be a constant or it is initialization of array");
159 return offs;
160 }
161 const TypePtr *t_ptr = adr_type->isa_ptr();
162 assert(t_ptr != NULL, "must be a pointer type");
163 return t_ptr->offset();
164 }
165
166 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
167 PointsToNode *f = ptnode_adr(from_i);
168 PointsToNode *t = ptnode_adr(to_i);
169
170 assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
171 assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
172 assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
173 assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
174 t->set_offset(offset);
175
176 add_edge(f, to_i, PointsToNode::FieldEdge);
177 }
178
179 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
180 // Don't change non-escaping state of NULL pointer.
181 if (ni == _noop_null || ni == _oop_null)
182 return;
183 PointsToNode *npt = ptnode_adr(ni);
184 PointsToNode::EscapeState old_es = npt->escape_state();
185 if (es > old_es)
186 npt->set_escape_state(es);
187 }
188
189 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
190 PointsToNode::EscapeState es, bool done) {
191 PointsToNode* ptadr = ptnode_adr(n->_idx);
192 ptadr->_node = n;
193 ptadr->set_node_type(nt);
194
195 // inline set_escape_state(idx, es);
196 PointsToNode::EscapeState old_es = ptadr->escape_state();
197 if (es > old_es)
198 ptadr->set_escape_state(es);
199
200 if (done)
201 _processed.set(n->_idx);
202 }
203
204 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
205 uint idx = n->_idx;
206 PointsToNode::EscapeState es;
207
208 // If we are still collecting or there were no non-escaping allocations
209 // we don't know the answer yet
210 if (_collecting)
211 return PointsToNode::UnknownEscape;
212
213 // if the node was created after the escape computation, return
214 // UnknownEscape
215 if (idx >= nodes_size())
216 return PointsToNode::UnknownEscape;
217
218 es = ptnode_adr(idx)->escape_state();
219
220 // if we have already computed a value, return it
221 if (es != PointsToNode::UnknownEscape &&
222 ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
223 return es;
224
225 // PointsTo() calls n->uncast() which can return a new ideal node.
226 if (n->uncast()->_idx >= nodes_size())
227 return PointsToNode::UnknownEscape;
228
229 PointsToNode::EscapeState orig_es = es;
230
231 // compute max escape state of anything this node could point to
232 for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
233 uint pt = i.elem;
234 PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
235 if (pes > es)
236 es = pes;
237 }
238 if (orig_es != es) {
239 // cache the computed escape state
240 assert(es > orig_es, "should have computed an escape state");
241 set_escape_state(idx, es);
242 } // orig_es could be PointsToNode::UnknownEscape
243 return es;
244 }
245
246 VectorSet* ConnectionGraph::PointsTo(Node * n) {
247 pt_ptset.Reset();
248 pt_visited.Reset();
249 pt_worklist.clear();
250
251 #ifdef ASSERT
252 Node *orig_n = n;
253 #endif
254
255 n = n->uncast();
256 PointsToNode* npt = ptnode_adr(n->_idx);
257
258 // If we have a JavaObject, return just that object
259 if (npt->node_type() == PointsToNode::JavaObject) {
260 pt_ptset.set(n->_idx);
261 return &pt_ptset;
262 }
263 #ifdef ASSERT
264 if (npt->_node == NULL) {
265 if (orig_n != n)
266 orig_n->dump();
267 n->dump();
268 assert(npt->_node != NULL, "unregistered node");
269 }
270 #endif
271 pt_worklist.push(n->_idx);
272 while(pt_worklist.length() > 0) {
273 int ni = pt_worklist.pop();
274 if (pt_visited.test_set(ni))
275 continue;
276
277 PointsToNode* pn = ptnode_adr(ni);
278 // ensure that all inputs of a Phi have been processed
279 assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
280
281 int edges_processed = 0;
282 uint e_cnt = pn->edge_count();
283 for (uint e = 0; e < e_cnt; e++) {
284 uint etgt = pn->edge_target(e);
285 PointsToNode::EdgeType et = pn->edge_type(e);
286 if (et == PointsToNode::PointsToEdge) {
287 pt_ptset.set(etgt);
288 edges_processed++;
289 } else if (et == PointsToNode::DeferredEdge) {
290 pt_worklist.push(etgt);
291 edges_processed++;
292 } else {
293 assert(false,"neither PointsToEdge or DeferredEdge");
294 }
295 }
296 if (edges_processed == 0) {
297 // no deferred or pointsto edges found. Assume the value was set
298 // outside this method. Add the phantom object to the pointsto set.
299 pt_ptset.set(_phantom_object);
300 }
301 }
302 return &pt_ptset;
303 }
304
305 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
306 // This method is most expensive during ConnectionGraph construction.
307 // Reuse vectorSet and an additional growable array for deferred edges.
308 deferred_edges->clear();
309 visited->Reset();
310
311 visited->set(ni);
312 PointsToNode *ptn = ptnode_adr(ni);
313
314 // Mark current edges as visited and move deferred edges to separate array.
315 for (uint i = 0; i < ptn->edge_count(); ) {
316 uint t = ptn->edge_target(i);
317 #ifdef ASSERT
318 assert(!visited->test_set(t), "expecting no duplications");
319 #else
320 visited->set(t);
321 #endif
322 if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
323 ptn->remove_edge(t, PointsToNode::DeferredEdge);
324 deferred_edges->append(t);
325 } else {
326 i++;
327 }
328 }
329 for (int next = 0; next < deferred_edges->length(); ++next) {
330 uint t = deferred_edges->at(next);
331 PointsToNode *ptt = ptnode_adr(t);
332 uint e_cnt = ptt->edge_count();
333 for (uint e = 0; e < e_cnt; e++) {
334 uint etgt = ptt->edge_target(e);
335 if (visited->test_set(etgt))
336 continue;
337
338 PointsToNode::EdgeType et = ptt->edge_type(e);
339 if (et == PointsToNode::PointsToEdge) {
340 add_pointsto_edge(ni, etgt);
341 if(etgt == _phantom_object) {
342 // Special case - field set outside (globally escaping).
343 set_escape_state(ni, PointsToNode::GlobalEscape);
344 }
345 } else if (et == PointsToNode::DeferredEdge) {
346 deferred_edges->append(etgt);
347 } else {
348 assert(false,"invalid connection graph");
349 }
350 }
351 }
352 }
353
354
355 // Add an edge to node given by "to_i" from any field of adr_i whose offset
356 // matches "offset" A deferred edge is added if to_i is a LocalVar, and
357 // a pointsto edge is added if it is a JavaObject
358
359 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
360 PointsToNode* an = ptnode_adr(adr_i);
361 PointsToNode* to = ptnode_adr(to_i);
362 bool deferred = (to->node_type() == PointsToNode::LocalVar);
363
364 for (uint fe = 0; fe < an->edge_count(); fe++) {
365 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
366 int fi = an->edge_target(fe);
367 PointsToNode* pf = ptnode_adr(fi);
368 int po = pf->offset();
369 if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
370 if (deferred)
371 add_deferred_edge(fi, to_i);
372 else
373 add_pointsto_edge(fi, to_i);
374 }
375 }
376 }
377
378 // Add a deferred edge from node given by "from_i" to any field of adr_i
379 // whose offset matches "offset".
380 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
381 PointsToNode* an = ptnode_adr(adr_i);
382 bool is_alloc = an->_node->is_Allocate();
383 for (uint fe = 0; fe < an->edge_count(); fe++) {
384 assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
385 int fi = an->edge_target(fe);
386 PointsToNode* pf = ptnode_adr(fi);
387 int offset = pf->offset();
388 if (!is_alloc) {
389 // Assume the field was set outside this method if it is not Allocation
390 add_pointsto_edge(fi, _phantom_object);
391 }
392 if (offset == offs || offset == Type::OffsetBot || offs == Type::OffsetBot) {
393 add_deferred_edge(from_i, fi);
394 }
395 }
396 }
397
398 // Helper functions
399
400 static Node* get_addp_base(Node *addp) {
401 assert(addp->is_AddP(), "must be AddP");
402 //
403 // AddP cases for Base and Address inputs:
404 // case #1. Direct object's field reference:
405 // Allocate
406 // |
407 // Proj #5 ( oop result )
408 // |
409 // CheckCastPP (cast to instance type)
410 // | |
411 // AddP ( base == address )
412 //
413 // case #2. Indirect object's field reference:
414 // Phi
415 // |
416 // CastPP (cast to instance type)
417 // | |
418 // AddP ( base == address )
419 //
420 // case #3. Raw object's field reference for Initialize node:
421 // Allocate
422 // |
423 // Proj #5 ( oop result )
424 // top |
425 // \ |
426 // AddP ( base == top )
427 //
428 // case #4. Array's element reference:
429 // {CheckCastPP | CastPP}
430 // | | |
431 // | AddP ( array's element offset )
432 // | |
433 // AddP ( array's offset )
434 //
435 // case #5. Raw object's field reference for arraycopy stub call:
436 // The inline_native_clone() case when the arraycopy stub is called
437 // after the allocation before Initialize and CheckCastPP nodes.
438 // Allocate
439 // |
440 // Proj #5 ( oop result )
441 // | |
442 // AddP ( base == address )
443 //
444 // case #6. Constant Pool, ThreadLocal, CastX2P or
445 // Raw object's field reference:
446 // {ConP, ThreadLocal, CastX2P, raw Load}
447 // top |
448 // \ |
449 // AddP ( base == top )
450 //
451 // case #7. Klass's field reference.
452 // LoadKlass
453 // | |
454 // AddP ( base == address )
455 //
456 // case #8. narrow Klass's field reference.
457 // LoadNKlass
458 // |
459 // DecodeN
460 // | |
461 // AddP ( base == address )
462 //
463 Node *base = addp->in(AddPNode::Base)->uncast();
464 if (base->is_top()) { // The AddP case #3 and #6.
465 base = addp->in(AddPNode::Address)->uncast();
466 while (base->is_AddP()) {
467 // Case #6 (unsafe access) may have several chained AddP nodes.
468 assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
469 base = base->in(AddPNode::Address)->uncast();
470 }
471 assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
472 base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
473 (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
474 (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
475 }
476 return base;
477 }
478
479 static Node* find_second_addp(Node* addp, Node* n) {
480 assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
481
482 Node* addp2 = addp->raw_out(0);
483 if (addp->outcnt() == 1 && addp2->is_AddP() &&
484 addp2->in(AddPNode::Base) == n &&
485 addp2->in(AddPNode::Address) == addp) {
486
487 assert(addp->in(AddPNode::Base) == n, "expecting the same base");
488 //
489 // Find array's offset to push it on worklist first and
490 // as result process an array's element offset first (pushed second)
491 // to avoid CastPP for the array's offset.
492 // Otherwise the inserted CastPP (LocalVar) will point to what
493 // the AddP (Field) points to. Which would be wrong since
494 // the algorithm expects the CastPP has the same point as
495 // as AddP's base CheckCastPP (LocalVar).
496 //
497 // ArrayAllocation
498 // |
499 // CheckCastPP
500 // |
501 // memProj (from ArrayAllocation CheckCastPP)
502 // | ||
503 // | || Int (element index)
504 // | || | ConI (log(element size))
505 // | || | /
506 // | || LShift
507 // | || /
508 // | AddP (array's element offset)
509 // | |
510 // | | ConI (array's offset: #12(32-bits) or #24(64-bits))
511 // | / /
512 // AddP (array's offset)
513 // |
514 // Load/Store (memory operation on array's element)
515 //
516 return addp2;
517 }
518 return NULL;
519 }
520
521 //
522 // Adjust the type and inputs of an AddP which computes the
523 // address of a field of an instance
524 //
525 bool ConnectionGraph::split_AddP(Node *addp, Node *base, PhaseGVN *igvn) {
526 const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
527 assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
528 const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
529 if (t == NULL) {
530 // We are computing a raw address for a store captured by an Initialize
531 // compute an appropriate address type (cases #3 and #5).
532 assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
533 assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
534 intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
535 assert(offs != Type::OffsetBot, "offset must be a constant");
536 t = base_t->add_offset(offs)->is_oopptr();
537 }
538 int inst_id = base_t->instance_id();
539 assert(!t->is_known_instance() || t->instance_id() == inst_id,
540 "old type must be non-instance or match new type");
541
542 // The type 't' could be subclass of 'base_t'.
543 // As result t->offset() could be large then base_t's size and it will
544 // cause the failure in add_offset() with narrow oops since TypeOopPtr()
545 // constructor verifies correctness of the offset.
546 //
547 // It could happened on subclass's branch (from the type profiling
548 // inlining) which was not eliminated during parsing since the exactness
549 // of the allocation type was not propagated to the subclass type check.
550 //
551 // Or the type 't' could be not related to 'base_t' at all.
552 // It could happened when CHA type is different from MDO type on a dead path
553 // (for example, from instanceof check) which is not collapsed during parsing.
554 //
555 // Do nothing for such AddP node and don't process its users since
556 // this code branch will go away.
557 //
558 if (!t->is_known_instance() &&
559 !base_t->klass()->is_subtype_of(t->klass())) {
560 return false; // bail out
561 }
562
563 const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
564 // Do NOT remove the next line: ensure a new alias index is allocated
565 // for the instance type. Note: C++ will not remove it since the call
566 // has side effect.
567 int alias_idx = _compile->get_alias_index(tinst);
568 igvn->set_type(addp, tinst);
569 // record the allocation in the node map
570 assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
571 set_map(addp->_idx, get_map(base->_idx));
572
573 // Set addp's Base and Address to 'base'.
574 Node *abase = addp->in(AddPNode::Base);
575 Node *adr = addp->in(AddPNode::Address);
576 if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
577 adr->in(0)->_idx == (uint)inst_id) {
578 // Skip AddP cases #3 and #5.
579 } else {
580 assert(!abase->is_top(), "sanity"); // AddP case #3
581 if (abase != base) {
582 igvn->hash_delete(addp);
583 addp->set_req(AddPNode::Base, base);
584 if (abase == adr) {
585 addp->set_req(AddPNode::Address, base);
586 } else {
587 // AddP case #4 (adr is array's element offset AddP node)
588 #ifdef ASSERT
589 const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
590 assert(adr->is_AddP() && atype != NULL &&
591 atype->instance_id() == inst_id, "array's element offset should be processed first");
592 #endif
593 }
594 igvn->hash_insert(addp);
595 }
596 }
597 // Put on IGVN worklist since at least addp's type was changed above.
598 record_for_optimizer(addp);
599 return true;
600 }
601
602 //
603 // Create a new version of orig_phi if necessary. Returns either the newly
604 // created phi or an existing phi. Sets create_new to indicate whether a new
605 // phi was created. Cache the last newly created phi in the node map.
606 //
607 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn, bool &new_created) {
608 Compile *C = _compile;
609 new_created = false;
610 int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
611 // nothing to do if orig_phi is bottom memory or matches alias_idx
612 if (phi_alias_idx == alias_idx) {
613 return orig_phi;
614 }
615 // Have we recently created a Phi for this alias index?
616 PhiNode *result = get_map_phi(orig_phi->_idx);
617 if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
618 return result;
619 }
620 // Previous check may fail when the same wide memory Phi was split into Phis
621 // for different memory slices. Search all Phis for this region.
622 if (result != NULL) {
623 Node* region = orig_phi->in(0);
624 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
625 Node* phi = region->fast_out(i);
626 if (phi->is_Phi() &&
627 C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
628 assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
629 return phi->as_Phi();
630 }
631 }
632 }
633 if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
634 if (C->do_escape_analysis() == true && !C->failing()) {
635 // Retry compilation without escape analysis.
636 // If this is the first failure, the sentinel string will "stick"
637 // to the Compile object, and the C2Compiler will see it and retry.
638 C->record_failure(C2Compiler::retry_no_escape_analysis());
639 }
640 return NULL;
641 }
642 orig_phi_worklist.append_if_missing(orig_phi);
643 const TypePtr *atype = C->get_adr_type(alias_idx);
644 result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
645 C->copy_node_notes_to(result, orig_phi);
646 igvn->set_type(result, result->bottom_type());
647 record_for_optimizer(result);
648
649 debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
650 assert(pn == NULL || pn == orig_phi, "wrong node");
651 set_map(orig_phi->_idx, result);
652 ptnode_adr(orig_phi->_idx)->_node = orig_phi;
653
654 new_created = true;
655 return result;
656 }
657
658 //
659 // Return a new version of Memory Phi "orig_phi" with the inputs having the
660 // specified alias index.
661 //
662 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *> &orig_phi_worklist, PhaseGVN *igvn) {
663
664 assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
665 Compile *C = _compile;
666 bool new_phi_created;
667 PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
668 if (!new_phi_created) {
669 return result;
670 }
671
672 GrowableArray<PhiNode *> phi_list;
673 GrowableArray<uint> cur_input;
674
675 PhiNode *phi = orig_phi;
676 uint idx = 1;
677 bool finished = false;
678 while(!finished) {
679 while (idx < phi->req()) {
680 Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
681 if (mem != NULL && mem->is_Phi()) {
682 PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
683 if (new_phi_created) {
684 // found an phi for which we created a new split, push current one on worklist and begin
685 // processing new one
686 phi_list.push(phi);
687 cur_input.push(idx);
688 phi = mem->as_Phi();
689 result = newphi;
690 idx = 1;
691 continue;
692 } else {
693 mem = newphi;
694 }
695 }
696 if (C->failing()) {
697 return NULL;
698 }
699 result->set_req(idx++, mem);
700 }
701 #ifdef ASSERT
702 // verify that the new Phi has an input for each input of the original
703 assert( phi->req() == result->req(), "must have same number of inputs.");
704 assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
705 #endif
706 // Check if all new phi's inputs have specified alias index.
707 // Otherwise use old phi.
708 for (uint i = 1; i < phi->req(); i++) {
709 Node* in = result->in(i);
710 assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
711 }
712 // we have finished processing a Phi, see if there are any more to do
713 finished = (phi_list.length() == 0 );
714 if (!finished) {
715 phi = phi_list.pop();
716 idx = cur_input.pop();
717 PhiNode *prev_result = get_map_phi(phi->_idx);
718 prev_result->set_req(idx++, result);
719 result = prev_result;
720 }
721 }
722 return result;
723 }
724
725
726 //
727 // The next methods are derived from methods in MemNode.
728 //
729 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
730 Node *mem = mmem;
731 // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
732 // means an array I have not precisely typed yet. Do not do any
733 // alias stuff with it any time soon.
734 if( toop->base() != Type::AnyPtr &&
735 !(toop->klass() != NULL &&
736 toop->klass()->is_java_lang_Object() &&
737 toop->offset() == Type::OffsetBot) ) {
738 mem = mmem->memory_at(alias_idx);
739 // Update input if it is progress over what we have now
740 }
741 return mem;
742 }
743
744 //
745 // Move memory users to their memory slices.
746 //
747 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *igvn) {
748 Compile* C = _compile;
749
750 const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
751 assert(tp != NULL, "ptr type");
752 int alias_idx = C->get_alias_index(tp);
753 int general_idx = C->get_general_index(alias_idx);
754
755 // Move users first
756 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
757 Node* use = n->fast_out(i);
758 if (use->is_MergeMem()) {
759 MergeMemNode* mmem = use->as_MergeMem();
760 assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
761 if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
762 continue; // Nothing to do
763 }
764 // Replace previous general reference to mem node.
765 uint orig_uniq = C->unique();
766 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
767 assert(orig_uniq == C->unique(), "no new nodes");
768 mmem->set_memory_at(general_idx, m);
769 --imax;
770 --i;
771 } else if (use->is_MemBar()) {
772 assert(!use->is_Initialize(), "initializing stores should not be moved");
773 if (use->req() > MemBarNode::Precedent &&
774 use->in(MemBarNode::Precedent) == n) {
775 // Don't move related membars.
776 record_for_optimizer(use);
777 continue;
778 }
779 tp = use->as_MemBar()->adr_type()->isa_ptr();
780 if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
781 alias_idx == general_idx) {
782 continue; // Nothing to do
783 }
784 // Move to general memory slice.
785 uint orig_uniq = C->unique();
786 Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
787 assert(orig_uniq == C->unique(), "no new nodes");
788 igvn->hash_delete(use);
789 imax -= use->replace_edge(n, m);
790 igvn->hash_insert(use);
791 record_for_optimizer(use);
792 --i;
793 #ifdef ASSERT
794 } else if (use->is_Mem()) {
795 if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
796 // Don't move related cardmark.
797 continue;
798 }
799 // Memory nodes should have new memory input.
800 tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
801 assert(tp != NULL, "ptr type");
802 int idx = C->get_alias_index(tp);
803 assert(get_map(use->_idx) != NULL || idx == alias_idx,
804 "Following memory nodes should have new memory input or be on the same memory slice");
805 } else if (use->is_Phi()) {
806 // Phi nodes should be split and moved already.
807 tp = use->as_Phi()->adr_type()->isa_ptr();
808 assert(tp != NULL, "ptr type");
809 int idx = C->get_alias_index(tp);
810 assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
811 } else {
812 use->dump();
813 assert(false, "should not be here");
814 #endif
815 }
816 }
817 }
818
819 //
820 // Search memory chain of "mem" to find a MemNode whose address
821 // is the specified alias index.
822 //
823 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *> &orig_phis, PhaseGVN *phase) {
824 if (orig_mem == NULL)
825 return orig_mem;
826 Compile* C = phase->C;
827 const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
828 bool is_instance = (toop != NULL) && toop->is_known_instance();
829 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
830 Node *prev = NULL;
831 Node *result = orig_mem;
832 while (prev != result) {
833 prev = result;
834 if (result == start_mem)
835 break; // hit one of our sentinels
836 if (result->is_Mem()) {
837 const Type *at = phase->type(result->in(MemNode::Address));
838 if (at == Type::TOP)
839 break; // Dead
840 assert (at->isa_ptr() != NULL, "pointer type required.");
841 int idx = C->get_alias_index(at->is_ptr());
842 if (idx == alias_idx)
843 break; // Found
844 if (!is_instance && (at->isa_oopptr() == NULL ||
845 !at->is_oopptr()->is_known_instance())) {
846 break; // Do not skip store to general memory slice.
847 }
848 result = result->in(MemNode::Memory);
849 }
850 if (!is_instance)
851 continue; // don't search further for non-instance types
852 // skip over a call which does not affect this memory slice
853 if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
854 Node *proj_in = result->in(0);
855 if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
856 break; // hit one of our sentinels
857 } else if (proj_in->is_Call()) {
858 CallNode *call = proj_in->as_Call();
859 if (!call->may_modify(toop, phase)) {
860 result = call->in(TypeFunc::Memory);
861 }
862 } else if (proj_in->is_Initialize()) {
863 AllocateNode* alloc = proj_in->as_Initialize()->allocation();
864 // Stop if this is the initialization for the object instance which
865 // which contains this memory slice, otherwise skip over it.
866 if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
867 result = proj_in->in(TypeFunc::Memory);
868 }
869 } else if (proj_in->is_MemBar()) {
870 result = proj_in->in(TypeFunc::Memory);
871 }
872 } else if (result->is_MergeMem()) {
873 MergeMemNode *mmem = result->as_MergeMem();
874 result = step_through_mergemem(mmem, alias_idx, toop);
875 if (result == mmem->base_memory()) {
876 // Didn't find instance memory, search through general slice recursively.
877 result = mmem->memory_at(C->get_general_index(alias_idx));
878 result = find_inst_mem(result, alias_idx, orig_phis, phase);
879 if (C->failing()) {
880 return NULL;
881 }
882 mmem->set_memory_at(alias_idx, result);
883 }
884 } else if (result->is_Phi() &&
885 C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
886 Node *un = result->as_Phi()->unique_input(phase);
887 if (un != NULL) {
888 orig_phis.append_if_missing(result->as_Phi());
889 result = un;
890 } else {
891 break;
892 }
893 } else if (result->is_ClearArray()) {
894 if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
895 // Can not bypass initialization of the instance
896 // we are looking for.
897 break;
898 }
899 // Otherwise skip it (the call updated 'result' value).
900 } else if (result->Opcode() == Op_SCMemProj) {
901 assert(result->in(0)->is_LoadStore(), "sanity");
902 const Type *at = phase->type(result->in(0)->in(MemNode::Address));
903 if (at != Type::TOP) {
904 assert (at->isa_ptr() != NULL, "pointer type required.");
905 int idx = C->get_alias_index(at->is_ptr());
906 assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
907 break;
908 }
909 result = result->in(0)->in(MemNode::Memory);
910 }
911 }
912 if (result->is_Phi()) {
913 PhiNode *mphi = result->as_Phi();
914 assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
915 const TypePtr *t = mphi->adr_type();
916 if (!is_instance) {
917 // Push all non-instance Phis on the orig_phis worklist to update inputs
918 // during Phase 4 if needed.
919 orig_phis.append_if_missing(mphi);
920 } else if (C->get_alias_index(t) != alias_idx) {
921 // Create a new Phi with the specified alias index type.
922 result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
923 }
924 }
925 // the result is either MemNode, PhiNode, InitializeNode.
926 return result;
927 }
928
929 //
930 // Convert the types of unescaped object to instance types where possible,
931 // propagate the new type information through the graph, and update memory
932 // edges and MergeMem inputs to reflect the new type.
933 //
934 // We start with allocations (and calls which may be allocations) on alloc_worklist.
935 // The processing is done in 4 phases:
936 //
937 // Phase 1: Process possible allocations from alloc_worklist. Create instance
938 // types for the CheckCastPP for allocations where possible.
939 // Propagate the the new types through users as follows:
940 // casts and Phi: push users on alloc_worklist
941 // AddP: cast Base and Address inputs to the instance type
942 // push any AddP users on alloc_worklist and push any memnode
943 // users onto memnode_worklist.
944 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
945 // search the Memory chain for a store with the appropriate type
946 // address type. If a Phi is found, create a new version with
947 // the appropriate memory slices from each of the Phi inputs.
948 // For stores, process the users as follows:
949 // MemNode: push on memnode_worklist
950 // MergeMem: push on mergemem_worklist
951 // Phase 3: Process MergeMem nodes from mergemem_worklist. Walk each memory slice
952 // moving the first node encountered of each instance type to the
953 // the input corresponding to its alias index.
954 // appropriate memory slice.
955 // Phase 4: Update the inputs of non-instance memory Phis and the Memory input of memnodes.
956 //
957 // In the following example, the CheckCastPP nodes are the cast of allocation
958 // results and the allocation of node 29 is unescaped and eligible to be an
959 // instance type.
960 //
961 // We start with:
962 //
963 // 7 Parm #memory
964 // 10 ConI "12"
965 // 19 CheckCastPP "Foo"
966 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
967 // 29 CheckCastPP "Foo"
968 // 30 AddP _ 29 29 10 Foo+12 alias_index=4
969 //
970 // 40 StoreP 25 7 20 ... alias_index=4
971 // 50 StoreP 35 40 30 ... alias_index=4
972 // 60 StoreP 45 50 20 ... alias_index=4
973 // 70 LoadP _ 60 30 ... alias_index=4
974 // 80 Phi 75 50 60 Memory alias_index=4
975 // 90 LoadP _ 80 30 ... alias_index=4
976 // 100 LoadP _ 80 20 ... alias_index=4
977 //
978 //
979 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
980 // and creating a new alias index for node 30. This gives:
981 //
982 // 7 Parm #memory
983 // 10 ConI "12"
984 // 19 CheckCastPP "Foo"
985 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
986 // 29 CheckCastPP "Foo" iid=24
987 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
988 //
989 // 40 StoreP 25 7 20 ... alias_index=4
990 // 50 StoreP 35 40 30 ... alias_index=6
991 // 60 StoreP 45 50 20 ... alias_index=4
992 // 70 LoadP _ 60 30 ... alias_index=6
993 // 80 Phi 75 50 60 Memory alias_index=4
994 // 90 LoadP _ 80 30 ... alias_index=6
995 // 100 LoadP _ 80 20 ... alias_index=4
996 //
997 // In phase 2, new memory inputs are computed for the loads and stores,
998 // And a new version of the phi is created. In phase 4, the inputs to
999 // node 80 are updated and then the memory nodes are updated with the
1000 // values computed in phase 2. This results in:
1001 //
1002 // 7 Parm #memory
1003 // 10 ConI "12"
1004 // 19 CheckCastPP "Foo"
1005 // 20 AddP _ 19 19 10 Foo+12 alias_index=4
1006 // 29 CheckCastPP "Foo" iid=24
1007 // 30 AddP _ 29 29 10 Foo+12 alias_index=6 iid=24
1008 //
1009 // 40 StoreP 25 7 20 ... alias_index=4
1010 // 50 StoreP 35 7 30 ... alias_index=6
1011 // 60 StoreP 45 40 20 ... alias_index=4
1012 // 70 LoadP _ 50 30 ... alias_index=6
1013 // 80 Phi 75 40 60 Memory alias_index=4
1014 // 120 Phi 75 50 50 Memory alias_index=6
1015 // 90 LoadP _ 120 30 ... alias_index=6
1016 // 100 LoadP _ 80 20 ... alias_index=4
1017 //
1018 void ConnectionGraph::split_unique_types(GrowableArray<Node *> &alloc_worklist) {
1019 GrowableArray<Node *> memnode_worklist;
1020 GrowableArray<PhiNode *> orig_phis;
1021
1022 PhaseIterGVN *igvn = _igvn;
1023 uint new_index_start = (uint) _compile->num_alias_types();
1024 Arena* arena = Thread::current()->resource_area();
1025 VectorSet visited(arena);
1026
1027
1028 // Phase 1: Process possible allocations from alloc_worklist.
1029 // Create instance types for the CheckCastPP for allocations where possible.
1030 //
1031 // (Note: don't forget to change the order of the second AddP node on
1032 // the alloc_worklist if the order of the worklist processing is changed,
1033 // see the comment in find_second_addp().)
1034 //
1035 while (alloc_worklist.length() != 0) {
1036 Node *n = alloc_worklist.pop();
1037 uint ni = n->_idx;
1038 const TypeOopPtr* tinst = NULL;
1039 if (n->is_Call()) {
1040 CallNode *alloc = n->as_Call();
1041 // copy escape information to call node
1042 PointsToNode* ptn = ptnode_adr(alloc->_idx);
1043 PointsToNode::EscapeState es = escape_state(alloc);
1044 // We have an allocation or call which returns a Java object,
1045 // see if it is unescaped.
1046 if (es != PointsToNode::NoEscape)
1047 continue;
1048
1049 // Find CheckCastPP for the allocate or for the return value of a call
1050 n = alloc->result_cast();
1051 if (n == NULL) { // No uses except Initialize node
1052 if (alloc->is_Allocate()) {
1053 // Set the scalar_replaceable flag for allocation
1054 // so it could be eliminated if it has no uses.
1055 alloc->as_Allocate()->_is_scalar_replaceable = true;
1056 }
1057 continue;
1058 }
1059 if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1060 assert(!alloc->is_Allocate(), "allocation should have unique type");
1061 continue;
1062 }
1063
1064 // The inline code for Object.clone() casts the allocation result to
1065 // java.lang.Object and then to the actual type of the allocated
1066 // object. Detect this case and use the second cast.
1067 // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
1068 // the allocation result is cast to java.lang.Object and then
1069 // to the actual Array type.
1070 if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
1071 && (alloc->is_AllocateArray() ||
1072 igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
1073 Node *cast2 = NULL;
1074 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1075 Node *use = n->fast_out(i);
1076 if (use->is_CheckCastPP()) {
1077 cast2 = use;
1078 break;
1079 }
1080 }
1081 if (cast2 != NULL) {
1082 n = cast2;
1083 } else {
1084 // Non-scalar replaceable if the allocation type is unknown statically
1085 // (reflection allocation), the object can't be restored during
1086 // deoptimization without precise type.
1087 continue;
1088 }
1089 }
1090 if (alloc->is_Allocate()) {
1091 // Set the scalar_replaceable flag for allocation
1092 // so it could be eliminated.
1093 alloc->as_Allocate()->_is_scalar_replaceable = true;
1094 }
1095 set_escape_state(n->_idx, es);
1096 // in order for an object to be scalar-replaceable, it must be:
1097 // - a direct allocation (not a call returning an object)
1098 // - non-escaping
1099 // - eligible to be a unique type
1100 // - not determined to be ineligible by escape analysis
1101 assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1102 ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1103 set_map(alloc->_idx, n);
1104 set_map(n->_idx, alloc);
1105 const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1106 if (t == NULL)
1107 continue; // not a TypeOopPtr
1108 tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1109 igvn->hash_delete(n);
1110 igvn->set_type(n, tinst);
1111 n->raise_bottom_type(tinst);
1112 igvn->hash_insert(n);
1113 record_for_optimizer(n);
1114 if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
1115
1116 // First, put on the worklist all Field edges from Connection Graph
1117 // which is more accurate then putting immediate users from Ideal Graph.
1118 for (uint e = 0; e < ptn->edge_count(); e++) {
1119 Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1120 assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
1121 "only AddP nodes are Field edges in CG");
1122 if (use->outcnt() > 0) { // Don't process dead nodes
1123 Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1124 if (addp2 != NULL) {
1125 assert(alloc->is_AllocateArray(),"array allocation was expected");
1126 alloc_worklist.append_if_missing(addp2);
1127 }
1128 alloc_worklist.append_if_missing(use);
1129 }
1130 }
1131
1132 // An allocation may have an Initialize which has raw stores. Scan
1133 // the users of the raw allocation result and push AddP users
1134 // on alloc_worklist.
1135 Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1136 assert (raw_result != NULL, "must have an allocation result");
1137 for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1138 Node *use = raw_result->fast_out(i);
1139 if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1140 Node* addp2 = find_second_addp(use, raw_result);
1141 if (addp2 != NULL) {
1142 assert(alloc->is_AllocateArray(),"array allocation was expected");
1143 alloc_worklist.append_if_missing(addp2);
1144 }
1145 alloc_worklist.append_if_missing(use);
1146 } else if (use->is_MemBar()) {
1147 memnode_worklist.append_if_missing(use);
1148 }
1149 }
1150 }
1151 } else if (n->is_AddP()) {
1152 VectorSet* ptset = PointsTo(get_addp_base(n));
1153 assert(ptset->Size() == 1, "AddP address is unique");
1154 uint elem = ptset->getelem(); // Allocation node's index
1155 if (elem == _phantom_object) {
1156 assert(false, "escaped allocation");
1157 continue; // Assume the value was set outside this method.
1158 }
1159 Node *base = get_map(elem); // CheckCastPP node
1160 if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1161 tinst = igvn->type(base)->isa_oopptr();
1162 } else if (n->is_Phi() ||
1163 n->is_CheckCastPP() ||
1164 n->is_EncodeP() ||
1165 n->is_DecodeN() ||
1166 (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1167 if (visited.test_set(n->_idx)) {
1168 assert(n->is_Phi(), "loops only through Phi's");
1169 continue; // already processed
1170 }
1171 VectorSet* ptset = PointsTo(n);
1172 if (ptset->Size() == 1) {
1173 uint elem = ptset->getelem(); // Allocation node's index
1174 if (elem == _phantom_object) {
1175 assert(false, "escaped allocation");
1176 continue; // Assume the value was set outside this method.
1177 }
1178 Node *val = get_map(elem); // CheckCastPP node
1179 TypeNode *tn = n->as_Type();
1180 tinst = igvn->type(val)->isa_oopptr();
1181 assert(tinst != NULL && tinst->is_known_instance() &&
1182 (uint)tinst->instance_id() == elem , "instance type expected.");
1183
1184 const Type *tn_type = igvn->type(tn);
1185 const TypeOopPtr *tn_t;
1186 if (tn_type->isa_narrowoop()) {
1187 tn_t = tn_type->make_ptr()->isa_oopptr();
1188 } else {
1189 tn_t = tn_type->isa_oopptr();
1190 }
1191
1192 if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1193 if (tn_type->isa_narrowoop()) {
1194 tn_type = tinst->make_narrowoop();
1195 } else {
1196 tn_type = tinst;
1197 }
1198 igvn->hash_delete(tn);
1199 igvn->set_type(tn, tn_type);
1200 tn->set_type(tn_type);
1201 igvn->hash_insert(tn);
1202 record_for_optimizer(n);
1203 } else {
1204 assert(tn_type == TypePtr::NULL_PTR ||
1205 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
1206 "unexpected type");
1207 continue; // Skip dead path with different type
1208 }
1209 }
1210 } else {
1211 debug_only(n->dump();)
1212 assert(false, "EA: unexpected node");
1213 continue;
1214 }
1215 // push allocation's users on appropriate worklist
1216 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1217 Node *use = n->fast_out(i);
1218 if(use->is_Mem() && use->in(MemNode::Address) == n) {
1219 // Load/store to instance's field
1220 memnode_worklist.append_if_missing(use);
1221 } else if (use->is_MemBar()) {
1222 memnode_worklist.append_if_missing(use);
1223 } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1224 Node* addp2 = find_second_addp(use, n);
1225 if (addp2 != NULL) {
1226 alloc_worklist.append_if_missing(addp2);
1227 }
1228 alloc_worklist.append_if_missing(use);
1229 } else if (use->is_Phi() ||
1230 use->is_CheckCastPP() ||
1231 use->is_EncodeP() ||
1232 use->is_DecodeN() ||
1233 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1234 alloc_worklist.append_if_missing(use);
1235 #ifdef ASSERT
1236 } else if (use->is_Mem()) {
1237 assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
1238 } else if (use->is_MergeMem()) {
1239 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1240 } else if (use->is_SafePoint()) {
1241 // Look for MergeMem nodes for calls which reference unique allocation
1242 // (through CheckCastPP nodes) even for debug info.
1243 Node* m = use->in(TypeFunc::Memory);
1244 if (m->is_MergeMem()) {
1245 assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1246 }
1247 } else {
1248 uint op = use->Opcode();
1249 if (!(op == Op_CmpP || op == Op_Conv2B ||
1250 op == Op_CastP2X || op == Op_StoreCM ||
1251 op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1252 op == Op_StrEquals || op == Op_StrIndexOf)) {
1253 n->dump();
1254 use->dump();
1255 assert(false, "EA: missing allocation reference path");
1256 }
1257 #endif
1258 }
1259 }
1260
1261 }
1262 // New alias types were created in split_AddP().
1263 uint new_index_end = (uint) _compile->num_alias_types();
1264
1265 // Phase 2: Process MemNode's from memnode_worklist. compute new address type and
1266 // compute new values for Memory inputs (the Memory inputs are not
1267 // actually updated until phase 4.)
1268 if (memnode_worklist.length() == 0)
1269 return; // nothing to do
1270
1271 while (memnode_worklist.length() != 0) {
1272 Node *n = memnode_worklist.pop();
1273 if (visited.test_set(n->_idx))
1274 continue;
1275 if (n->is_Phi() || n->is_ClearArray()) {
1276 // we don't need to do anything, but the users must be pushed
1277 } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1278 // we don't need to do anything, but the users must be pushed
1279 n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1280 if (n == NULL)
1281 continue;
1282 } else {
1283 assert(n->is_Mem(), "memory node required.");
1284 Node *addr = n->in(MemNode::Address);
1285 const Type *addr_t = igvn->type(addr);
1286 if (addr_t == Type::TOP)
1287 continue;
1288 assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1289 int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1290 assert ((uint)alias_idx < new_index_end, "wrong alias index");
1291 Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1292 if (_compile->failing()) {
1293 return;
1294 }
1295 if (mem != n->in(MemNode::Memory)) {
1296 // We delay the memory edge update since we need old one in
1297 // MergeMem code below when instances memory slices are separated.
1298 debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1299 assert(pn == NULL || pn == n, "wrong node");
1300 set_map(n->_idx, mem);
1301 ptnode_adr(n->_idx)->_node = n;
1302 }
1303 if (n->is_Load()) {
1304 continue; // don't push users
1305 } else if (n->is_LoadStore()) {
1306 // get the memory projection
1307 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1308 Node *use = n->fast_out(i);
1309 if (use->Opcode() == Op_SCMemProj) {
1310 n = use;
1311 break;
1312 }
1313 }
1314 assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1315 }
1316 }
1317 // push user on appropriate worklist
1318 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1319 Node *use = n->fast_out(i);
1320 if (use->is_Phi() || use->is_ClearArray()) {
1321 memnode_worklist.append_if_missing(use);
1322 } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1323 if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
1324 continue;
1325 memnode_worklist.append_if_missing(use);
1326 } else if (use->is_MemBar()) {
1327 memnode_worklist.append_if_missing(use);
1328 #ifdef ASSERT
1329 } else if(use->is_Mem()) {
1330 assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
1331 } else if (use->is_MergeMem()) {
1332 assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1333 } else {
1334 uint op = use->Opcode();
1335 if (!(op == Op_StoreCM ||
1336 (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
1337 strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
1338 op == Op_AryEq || op == Op_StrComp ||
1339 op == Op_StrEquals || op == Op_StrIndexOf)) {
1340 n->dump();
1341 use->dump();
1342 assert(false, "EA: missing memory path");
1343 }
1344 #endif
1345 }
1346 }
1347 }
1348
1349 // Phase 3: Process MergeMem nodes from mergemem_worklist.
1350 // Walk each memory slice moving the first node encountered of each
1351 // instance type to the the input corresponding to its alias index.
1352 uint length = _mergemem_worklist.length();
1353 for( uint next = 0; next < length; ++next ) {
1354 MergeMemNode* nmm = _mergemem_worklist.at(next);
1355 assert(!visited.test_set(nmm->_idx), "should not be visited before");
1356 // Note: we don't want to use MergeMemStream here because we only want to
1357 // scan inputs which exist at the start, not ones we add during processing.
1358 // Note 2: MergeMem may already contains instance memory slices added
1359 // during find_inst_mem() call when memory nodes were processed above.
1360 igvn->hash_delete(nmm);
1361 uint nslices = nmm->req();
1362 for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1363 Node* mem = nmm->in(i);
1364 Node* cur = NULL;
1365 if (mem == NULL || mem->is_top())
1366 continue;
1367 // First, update mergemem by moving memory nodes to corresponding slices
1368 // if their type became more precise since this mergemem was created.
1369 while (mem->is_Mem()) {
1370 const Type *at = igvn->type(mem->in(MemNode::Address));
1371 if (at != Type::TOP) {
1372 assert (at->isa_ptr() != NULL, "pointer type required.");
1373 uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1374 if (idx == i) {
1375 if (cur == NULL)
1376 cur = mem;
1377 } else {
1378 if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1379 nmm->set_memory_at(idx, mem);
1380 }
1381 }
1382 }
1383 mem = mem->in(MemNode::Memory);
1384 }
1385 nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1386 // Find any instance of the current type if we haven't encountered
1387 // already a memory slice of the instance along the memory chain.
1388 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1389 if((uint)_compile->get_general_index(ni) == i) {
1390 Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1391 if (nmm->is_empty_memory(m)) {
1392 Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1393 if (_compile->failing()) {
1394 return;
1395 }
1396 nmm->set_memory_at(ni, result);
1397 }
1398 }
1399 }
1400 }
1401 // Find the rest of instances values
1402 for (uint ni = new_index_start; ni < new_index_end; ni++) {
1403 const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
1404 Node* result = step_through_mergemem(nmm, ni, tinst);
1405 if (result == nmm->base_memory()) {
1406 // Didn't find instance memory, search through general slice recursively.
1407 result = nmm->memory_at(_compile->get_general_index(ni));
1408 result = find_inst_mem(result, ni, orig_phis, igvn);
1409 if (_compile->failing()) {
1410 return;
1411 }
1412 nmm->set_memory_at(ni, result);
1413 }
1414 }
1415 igvn->hash_insert(nmm);
1416 record_for_optimizer(nmm);
1417 }
1418
1419 // Phase 4: Update the inputs of non-instance memory Phis and
1420 // the Memory input of memnodes
1421 // First update the inputs of any non-instance Phi's from
1422 // which we split out an instance Phi. Note we don't have
1423 // to recursively process Phi's encounted on the input memory
1424 // chains as is done in split_memory_phi() since they will
1425 // also be processed here.
1426 for (int j = 0; j < orig_phis.length(); j++) {
1427 PhiNode *phi = orig_phis.at(j);
1428 int alias_idx = _compile->get_alias_index(phi->adr_type());
1429 igvn->hash_delete(phi);
1430 for (uint i = 1; i < phi->req(); i++) {
1431 Node *mem = phi->in(i);
1432 Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1433 if (_compile->failing()) {
1434 return;
1435 }
1436 if (mem != new_mem) {
1437 phi->set_req(i, new_mem);
1438 }
1439 }
1440 igvn->hash_insert(phi);
1441 record_for_optimizer(phi);
1442 }
1443
1444 // Update the memory inputs of MemNodes with the value we computed
1445 // in Phase 2 and move stores memory users to corresponding memory slices.
1446
1447 // Disable memory split verification code until the fix for 6984348.
1448 // Currently it produces false negative results since it does not cover all cases.
1449 #if 0 // ifdef ASSERT
1450 visited.Reset();
1451 Node_Stack old_mems(arena, _compile->unique() >> 2);
1452 #endif
1453 for (uint i = 0; i < nodes_size(); i++) {
1454 Node *nmem = get_map(i);
1455 if (nmem != NULL) {
1456 Node *n = ptnode_adr(i)->_node;
1457 assert(n != NULL, "sanity");
1458 if (n->is_Mem()) {
1459 #if 0 // ifdef ASSERT
1460 Node* old_mem = n->in(MemNode::Memory);
1461 if (!visited.test_set(old_mem->_idx)) {
1462 old_mems.push(old_mem, old_mem->outcnt());
1463 }
1464 #endif
1465 assert(n->in(MemNode::Memory) != nmem, "sanity");
1466 if (!n->is_Load()) {
1467 // Move memory users of a store first.
1468 move_inst_mem(n, orig_phis, igvn);
1469 }
1470 // Now update memory input
1471 igvn->hash_delete(n);
1472 n->set_req(MemNode::Memory, nmem);
1473 igvn->hash_insert(n);
1474 record_for_optimizer(n);
1475 } else {
1476 assert(n->is_Allocate() || n->is_CheckCastPP() ||
1477 n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1478 }
1479 }
1480 }
1481 #if 0 // ifdef ASSERT
1482 // Verify that memory was split correctly
1483 while (old_mems.is_nonempty()) {
1484 Node* old_mem = old_mems.node();
1485 uint old_cnt = old_mems.index();
1486 old_mems.pop();
1487 assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
1488 }
1489 #endif
1490 }
1491
1492 bool ConnectionGraph::has_candidates(Compile *C) {
1493 // EA brings benefits only when the code has allocations and/or locks which
1494 // are represented by ideal Macro nodes.
1495 int cnt = C->macro_count();
1496 for( int i=0; i < cnt; i++ ) {
1497 Node *n = C->macro_node(i);
1498 if ( n->is_Allocate() )
1499 return true;
1500 if( n->is_Lock() ) {
1501 Node* obj = n->as_Lock()->obj_node()->uncast();
1502 if( !(obj->is_Parm() || obj->is_Con()) )
1503 return true;
1504 }
1505 }
1506 return false;
1507 }
1508
1509 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1510 // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1511 // to create space for them in ConnectionGraph::_nodes[].
1512 Node* oop_null = igvn->zerocon(T_OBJECT);
1513 Node* noop_null = igvn->zerocon(T_NARROWOOP);
1514
1515 ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1516 // Perform escape analysis
1517 if (congraph->compute_escape()) {
1518 // There are non escaping objects.
1519 C->set_congraph(congraph);
1520 }
1521
1522 // Cleanup.
1523 if (oop_null->outcnt() == 0)
1524 igvn->hash_delete(oop_null);
1525 if (noop_null->outcnt() == 0)
1526 igvn->hash_delete(noop_null);
1527 }
1528
1529 bool ConnectionGraph::compute_escape() {
1530 Compile* C = _compile;
1531
1532 // 1. Populate Connection Graph (CG) with Ideal nodes.
1533
1534 Unique_Node_List worklist_init;
1535 worklist_init.map(C->unique(), NULL); // preallocate space
1536
1537 // Initialize worklist
1538 if (C->root() != NULL) {
1539 worklist_init.push(C->root());
1540 }
1541
1542 GrowableArray<Node*> alloc_worklist;
1543 GrowableArray<int> cg_worklist;
1544 PhaseGVN* igvn = _igvn;
1545 bool has_allocations = false;
1546
1547 // Push all useful nodes onto CG list and set their type.
1548 for( uint next = 0; next < worklist_init.size(); ++next ) {
1549 Node* n = worklist_init.at(next);
1550 record_for_escape_analysis(n, igvn);
1551 // Only allocations and java static calls results are checked
1552 // for an escape status. See process_call_result() below.
1553 if (n->is_Allocate() || n->is_CallStaticJava() &&
1554 ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1555 has_allocations = true;
1556 if (n->is_Allocate())
1557 alloc_worklist.append(n);
1558 }
1559 if(n->is_AddP()) {
1560 // Collect address nodes. Use them during stage 3 below
1561 // to build initial connection graph field edges.
1562 cg_worklist.append(n->_idx);
1563 } else if (n->is_MergeMem()) {
1564 // Collect all MergeMem nodes to add memory slices for
1565 // scalar replaceable objects in split_unique_types().
1566 _mergemem_worklist.append(n->as_MergeMem());
1567 }
1568 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1569 Node* m = n->fast_out(i); // Get user
1570 worklist_init.push(m);
1571 }
1572 }
1573
1574 if (!has_allocations) {
1575 _collecting = false;
1576 return false; // Nothing to do.
1577 }
1578
1579 // 2. First pass to create simple CG edges (doesn't require to walk CG).
1580 uint delayed_size = _delayed_worklist.size();
1581 for( uint next = 0; next < delayed_size; ++next ) {
1582 Node* n = _delayed_worklist.at(next);
1583 build_connection_graph(n, igvn);
1584 }
1585
1586 // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
1587 // to reduce number of iterations during stage 4 below.
1588 uint cg_length = cg_worklist.length();
1589 for( uint next = 0; next < cg_length; ++next ) {
1590 int ni = cg_worklist.at(next);
1591 Node* n = ptnode_adr(ni)->_node;
1592 Node* base = get_addp_base(n);
1593 if (base->is_Proj())
1594 base = base->in(0);
1595 PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
1596 if (nt == PointsToNode::JavaObject) {
1597 build_connection_graph(n, igvn);
1598 }
1599 }
1600
1601 cg_worklist.clear();
1602 cg_worklist.append(_phantom_object);
1603 GrowableArray<uint> worklist;
1604
1605 // 4. Build Connection Graph which need
1606 // to walk the connection graph.
1607 _progress = false;
1608 for (uint ni = 0; ni < nodes_size(); ni++) {
1609 PointsToNode* ptn = ptnode_adr(ni);
1610 Node *n = ptn->_node;
1611 if (n != NULL) { // Call, AddP, LoadP, StoreP
1612 build_connection_graph(n, igvn);
1613 if (ptn->node_type() != PointsToNode::UnknownType)
1614 cg_worklist.append(n->_idx); // Collect CG nodes
1615 if (!_processed.test(n->_idx))
1616 worklist.append(n->_idx); // Collect C/A/L/S nodes
1617 }
1618 }
1619
1620 // After IGVN user nodes may have smaller _idx than
1621 // their inputs so they will be processed first in
1622 // previous loop. Because of that not all Graph
1623 // edges will be created. Walk over interesting
1624 // nodes again until no new edges are created.
1625 //
1626 // Normally only 1-3 passes needed to build
1627 // Connection Graph depending on graph complexity.
1628 // Observed 8 passes in jvm2008 compiler.compiler.
1629 // Set limit to 20 to catch situation when something
1630 // did go wrong and recompile the method without EA.
1631
1632 #define CG_BUILD_ITER_LIMIT 20
1633
1634 uint length = worklist.length();
1635 int iterations = 0;
1636 while(_progress && (iterations++ < CG_BUILD_ITER_LIMIT)) {
1637 _progress = false;
1638 for( uint next = 0; next < length; ++next ) {
1639 int ni = worklist.at(next);
1640 PointsToNode* ptn = ptnode_adr(ni);
1641 Node* n = ptn->_node;
1642 assert(n != NULL, "should be known node");
1643 build_connection_graph(n, igvn);
1644 }
1645 }
1646 if (iterations >= CG_BUILD_ITER_LIMIT) {
1647 assert(iterations < CG_BUILD_ITER_LIMIT,
1648 err_msg("infinite EA connection graph build with %d nodes and worklist size %d",
1649 nodes_size(), length));
1650 // Possible infinite build_connection_graph loop,
1651 // retry compilation without escape analysis.
1652 C->record_failure(C2Compiler::retry_no_escape_analysis());
1653 _collecting = false;
1654 return false;
1655 }
1656 #undef CG_BUILD_ITER_LIMIT
1657
1658 Arena* arena = Thread::current()->resource_area();
1659 VectorSet visited(arena);
1660
1661 // 5. Find fields initializing values for not escaped allocations
1662 length = alloc_worklist.length();
1663 for (uint next = 0; next < length; ++next) {
1664 Node* n = alloc_worklist.at(next);
1665 if (ptnode_adr(n->_idx)->escape_state() == PointsToNode::NoEscape) {
1666 find_init_values(n, &visited, igvn);
1667 }
1668 }
1669
1670 worklist.clear();
1671 worklist_init.clear();
1672 alloc_worklist.clear();
1673
1674 // 6. Remove deferred edges from the graph.
1675 cg_length = cg_worklist.length();
1676 for (uint next = 0; next < cg_length; ++next) {
1677 int ni = cg_worklist.at(next);
1678 PointsToNode* ptn = ptnode_adr(ni);
1679 PointsToNode::NodeType nt = ptn->node_type();
1680 if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1681 remove_deferred(ni, &worklist, &visited);
1682 Node *n = ptn->_node;
1683 if (n->is_AddP()) {
1684 alloc_worklist.append(n);
1685 }
1686 }
1687 }
1688
1689 // 7. Adjust escape state of nonescaping objects.
1690 length = alloc_worklist.length();
1691 for (uint next = 0; next < length; ++next) {
1692 Node* n = alloc_worklist.at(next);
1693 adjust_escape_state(n);
1694 }
1695
1696 // 8. Propagate escape states.
1697 worklist.clear();
1698 bool has_non_escaping_obj = false;
1699
1700 // mark all nodes reachable from GlobalEscape nodes
1701 (void)propagate_escape_state(&cg_worklist, &worklist, PointsToNode::GlobalEscape);
1702
1703 // mark all nodes reachable from ArgEscape nodes
1704 has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ArgEscape);
1705
1706 // mark all nodes reachable from ControlEscape nodes
1707 has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ControlEscape);
1708
1709 alloc_worklist.clear();
1710
1711 // push all NoEscape nodes on the worklist
1712 for( uint next = 0; next < cg_length; ++next ) {
1713 int nk = cg_worklist.at(next);
1714 if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1715 worklist.push(nk);
1716 }
1717 // mark all nodes reachable from NoEscape nodes
1718 while(worklist.length() > 0) {
1719 uint nk = worklist.pop();
1720 PointsToNode* ptn = ptnode_adr(nk);
1721 if (ptn->node_type() == PointsToNode::JavaObject &&
1722 !(nk == _noop_null || nk == _oop_null))
1723 has_non_escaping_obj = true; // Non Escape
1724 Node* n = ptn->_node;
1725 if (n->is_Allocate()) {
1726 // Push scalar replaceable allocations on alloc_worklist
1727 // for processing in split_unique_types().
1728 alloc_worklist.append(n);
1729 }
1730 uint e_cnt = ptn->edge_count();
1731 for (uint ei = 0; ei < e_cnt; ei++) {
1732 uint npi = ptn->edge_target(ei);
1733 PointsToNode *np = ptnode_adr(npi);
1734 if (np->escape_state() < PointsToNode::NoEscape) {
1735 set_escape_state(npi, PointsToNode::NoEscape);
1736 worklist.push(npi);
1737 }
1738 }
1739 }
1740
1741 _collecting = false;
1742 assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1743
1744 assert(ptnode_adr(_oop_null)->escape_state() == PointsToNode::NoEscape, "sanity");
1745 if (UseCompressedOops) {
1746 assert(ptnode_adr(_noop_null)->escape_state() == PointsToNode::NoEscape, "sanity");
1747 }
1748
1749 if (EliminateLocks && has_non_escaping_obj) {
1750 // Mark locks before changing ideal graph.
1751 int cnt = C->macro_count();
1752 for( int i=0; i < cnt; i++ ) {
1753 Node *n = C->macro_node(i);
1754 if (n->is_AbstractLock()) { // Lock and Unlock nodes
1755 AbstractLockNode* alock = n->as_AbstractLock();
1756 if (!alock->is_eliminated()) {
1757 PointsToNode::EscapeState es = escape_state(alock->obj_node());
1758 assert(es != PointsToNode::UnknownEscape, "should know");
1759 if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
1760 // Mark it eliminated
1761 alock->set_eliminated();
1762 }
1763 }
1764 }
1765 }
1766 }
1767
1768 #ifndef PRODUCT
1769 if (PrintEscapeAnalysis) {
1770 dump(); // Dump ConnectionGraph
1771 }
1772 #endif
1773
1774 bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1775 if ( has_scalar_replaceable_candidates &&
1776 C->AliasLevel() >= 3 && EliminateAllocations ) {
1777
1778 // Now use the escape information to create unique types for
1779 // scalar replaceable objects.
1780 split_unique_types(alloc_worklist);
1781
1782 if (C->failing()) return false;
1783
1784 C->print_method("After Escape Analysis", 2);
1785
1786 #ifdef ASSERT
1787 } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1788 tty->print("=== No allocations eliminated for ");
1789 C->method()->print_short_name();
1790 if(!EliminateAllocations) {
1791 tty->print(" since EliminateAllocations is off ===");
1792 } else if(!has_scalar_replaceable_candidates) {
1793 tty->print(" since there are no scalar replaceable candidates ===");
1794 } else if(C->AliasLevel() < 3) {
1795 tty->print(" since AliasLevel < 3 ===");
1796 }
1797 tty->cr();
1798 #endif
1799 }
1800 return has_non_escaping_obj;
1801 }
1802
1803 // Find fields initializing values for allocations.
1804 void ConnectionGraph::find_init_values(Node* alloc, VectorSet* visited, PhaseTransform* phase) {
1805 assert(alloc->is_Allocate(), "Should be called for Allocate nodes only");
1806 PointsToNode* pta = ptnode_adr(alloc->_idx);
1807 assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
1808 InitializeNode* ini = alloc->as_Allocate()->initialization();
1809
1810 Compile* C = _compile;
1811 visited->Reset();
1812 // Check if a oop field's initializing value is recorded and add
1813 // a corresponding NULL field's value if it is not recorded.
1814 // Connection Graph does not record a default initialization by NULL
1815 // captured by Initialize node.
1816 //
1817 uint ae_cnt = pta->edge_count();
1818 for (uint ei = 0; ei < ae_cnt; ei++) {
1819 uint nidx = pta->edge_target(ei); // Field (AddP)
1820 PointsToNode* ptn = ptnode_adr(nidx);
1821 assert(ptn->_node->is_AddP(), "Should be AddP nodes only");
1822 int offset = ptn->offset();
1823 if (offset != Type::OffsetBot &&
1824 offset != oopDesc::klass_offset_in_bytes() &&
1825 !visited->test_set(offset)) {
1826
1827 // Check only oop fields.
1828 const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
1829 BasicType basic_field_type = T_INT;
1830 if (adr_type->isa_instptr()) {
1831 ciField* field = C->alias_type(adr_type->isa_instptr())->field();
1832 if (field != NULL) {
1833 basic_field_type = field->layout_type();
1834 } else {
1835 // Ignore non field load (for example, klass load)
1836 }
1837 } else if (adr_type->isa_aryptr()) {
1838 if (offset != arrayOopDesc::length_offset_in_bytes()) {
1839 const Type* elemtype = adr_type->isa_aryptr()->elem();
1840 basic_field_type = elemtype->array_element_basic_type();
1841 } else {
1842 // Ignore array length load
1843 }
1844 #ifdef ASSERT
1845 } else {
1846 // Raw pointers are used for initializing stores so skip it
1847 // since it should be recorded already
1848 Node* base = get_addp_base(ptn->_node);
1849 assert(adr_type->isa_rawptr() && base->is_Proj() &&
1850 (base->in(0) == alloc),"unexpected pointer type");
1851 #endif
1852 }
1853 if (basic_field_type == T_OBJECT ||
1854 basic_field_type == T_NARROWOOP ||
1855 basic_field_type == T_ARRAY) {
1856 Node* value = NULL;
1857 if (ini != NULL) {
1858 BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1859 Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1860 if (store != NULL && store->is_Store()) {
1861 value = store->in(MemNode::ValueIn);
1862 } else if (ptn->edge_count() > 0) { // Are there oop stores?
1863 // Check for a store which follows allocation without branches.
1864 // For example, a volatile field store is not collected
1865 // by Initialize node. TODO: it would be nice to use idom() here.
1866 //
1867 // Search all references to the same field which use different
1868 // AddP nodes, for example, in the next case:
1869 //
1870 // Point p[] = new Point[1];
1871 // if ( x ) { p[0] = new Point(); p[0].x = x; }
1872 // if ( p[0] != null ) { y = p[0].x; } // has CastPP
1873 //
1874 for (uint next = ei; (next < ae_cnt) && (value == NULL); next++) {
1875 uint fpi = pta->edge_target(next); // Field (AddP)
1876 PointsToNode *ptf = ptnode_adr(fpi);
1877 if (ptf->offset() == offset) {
1878 Node* nf = ptf->_node;
1879 for (DUIterator_Fast imax, i = nf->fast_outs(imax); i < imax; i++) {
1880 store = nf->fast_out(i);
1881 if (store->is_Store() && store->in(0) != NULL) {
1882 Node* ctrl = store->in(0);
1883 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
1884 ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
1885 ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
1886 ctrl = ctrl->in(0);
1887 }
1888 if (ctrl == ini || ctrl == alloc) {
1889 value = store->in(MemNode::ValueIn);
1890 break;
1891 }
1892 }
1893 }
1894 }
1895 }
1896 }
1897 }
1898 if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1899 // A field's initializing value was not recorded. Add NULL.
1900 uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1901 add_edge_from_fields(alloc->_idx, null_idx, offset);
1902 }
1903 }
1904 }
1905 }
1906 }
1907
1908 // Adjust escape state after Connection Graph is built.
1909 void ConnectionGraph::adjust_escape_state(Node* n) {
1910 PointsToNode* ptn = ptnode_adr(n->_idx);
1911 assert(n->is_AddP(), "Should be called for AddP nodes only");
1912 // Search for objects which are not scalar replaceable.
1913 // Mark their escape state as ControlEscape to propagate the state
1914 // to referenced objects.
1915
1916 int offset = ptn->offset();
1917 Node* base = get_addp_base(n);
1918 VectorSet* ptset = PointsTo(base);
1919 int ptset_size = ptset->Size();
1920
1921 // An object is not scalar replaceable if the field which may point
1922 // to it has unknown offset (unknown element of an array of objects).
1923 //
1924
1925 if (offset == Type::OffsetBot) {
1926 uint e_cnt = ptn->edge_count();
1927 for (uint ei = 0; ei < e_cnt; ei++) {
1928 uint npi = ptn->edge_target(ei);
1929 set_escape_state(npi, PointsToNode::ControlEscape);
1930 }
1931 }
1932
1933 // Currently an object is not scalar replaceable if a LoadStore node
1934 // access its field since the field value is unknown after it.
1935 //
1936 bool has_LoadStore = false;
1937 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1938 Node *use = n->fast_out(i);
1939 if (use->is_LoadStore()) {
1940 has_LoadStore = true;
1941 break;
1942 }
1943 }
1944 // An object is not scalar replaceable if the address points
1945 // to unknown field (unknown element for arrays, offset is OffsetBot).
1946 //
1947 // Or the address may point to more then one object. This may produce
1948 // the false positive result (set escape to ControlEscape)
1949 // since the flow-insensitive escape analysis can't separate
1950 // the case when stores overwrite the field's value from the case
1951 // when stores happened on different control branches.
1952 //
1953 // Note: it will disable scalar replacement in some cases:
1954 //
1955 // Point p[] = new Point[1];
1956 // p[0] = new Point(); // Will be not scalar replaced
1957 //
1958 // but it will save us from incorrect optimizations in next cases:
1959 //
1960 // Point p[] = new Point[1];
1961 // if ( x ) p[0] = new Point(); // Will be not scalar replaced
1962 //
1963 if (ptset_size > 1 || ptset_size != 0 &&
1964 (has_LoadStore || offset == Type::OffsetBot)) {
1965 for( VectorSetI j(ptset); j.test(); ++j ) {
1966 set_escape_state(j.elem, PointsToNode::ControlEscape);
1967 }
1968 }
1969 }
1970
1971 // Propagate escape states to referenced nodes.
1972 bool ConnectionGraph::propagate_escape_state(GrowableArray<int>* cg_worklist,
1973 GrowableArray<uint>* worklist,
1974 PointsToNode::EscapeState esc_state) {
1975 bool has_java_obj = false;
1976
1977 // push all nodes with the same escape state on the worklist
1978 uint cg_length = cg_worklist->length();
1979 for (uint next = 0; next < cg_length; ++next) {
1980 int nk = cg_worklist->at(next);
1981 if (ptnode_adr(nk)->escape_state() == esc_state)
1982 worklist->push(nk);
1983 }
1984 // mark all reachable nodes
1985 while (worklist->length() > 0) {
1986 PointsToNode* ptn = ptnode_adr(worklist->pop());
1987 if (ptn->node_type() == PointsToNode::JavaObject) {
1988 has_java_obj = true;
1989 }
1990 uint e_cnt = ptn->edge_count();
1991 for (uint ei = 0; ei < e_cnt; ei++) {
1992 uint npi = ptn->edge_target(ei);
1993 PointsToNode *np = ptnode_adr(npi);
1994 if (np->escape_state() < esc_state) {
1995 set_escape_state(npi, esc_state);
1996 worklist->push(npi);
1997 }
1998 }
1999 }
2000 // Has not escaping java objects
2001 return has_java_obj && (esc_state < PointsToNode::GlobalEscape);
2002 }
2003
2004 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
2005
2006 switch (call->Opcode()) {
2007 #ifdef ASSERT
2008 case Op_Allocate:
2009 case Op_AllocateArray:
2010 case Op_Lock:
2011 case Op_Unlock:
2012 assert(false, "should be done already");
2013 break;
2014 #endif
2015 case Op_CallLeaf:
2016 case Op_CallLeafNoFP:
2017 {
2018 // Stub calls, objects do not escape but they are not scale replaceable.
2019 // Adjust escape state for outgoing arguments.
2020 const TypeTuple * d = call->tf()->domain();
2021 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2022 const Type* at = d->field_at(i);
2023 Node *arg = call->in(i)->uncast();
2024 const Type *aat = phase->type(arg);
2025 if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
2026 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
2027
2028 assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2029 aat->isa_ptr() != NULL, "expecting an Ptr");
2030 #ifdef ASSERT
2031 if (!(call->Opcode() == Op_CallLeafNoFP &&
2032 call->as_CallLeaf()->_name != NULL &&
2033 (strstr(call->as_CallLeaf()->_name, "arraycopy") != 0) ||
2034 call->as_CallLeaf()->_name != NULL &&
2035 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre") == 0 ||
2036 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
2037 ) {
2038 call->dump();
2039 assert(false, "EA: unexpected CallLeaf");
2040 }
2041 #endif
2042 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
2043 if (arg->is_AddP()) {
2044 //
2045 // The inline_native_clone() case when the arraycopy stub is called
2046 // after the allocation before Initialize and CheckCastPP nodes.
2047 //
2048 // Set AddP's base (Allocate) as not scalar replaceable since
2049 // pointer to the base (with offset) is passed as argument.
2050 //
2051 arg = get_addp_base(arg);
2052 }
2053 for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2054 uint pt = j.elem;
2055 set_escape_state(pt, PointsToNode::ArgEscape);
2056 }
2057 }
2058 }
2059 break;
2060 }
2061
2062 case Op_CallStaticJava:
2063 // For a static call, we know exactly what method is being called.
2064 // Use bytecode estimator to record the call's escape affects
2065 {
2066 ciMethod *meth = call->as_CallJava()->method();
2067 BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
2068 // fall-through if not a Java method or no analyzer information
2069 if (call_analyzer != NULL) {
2070 const TypeTuple * d = call->tf()->domain();
2071 bool copy_dependencies = false;
2072 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2073 const Type* at = d->field_at(i);
2074 int k = i - TypeFunc::Parms;
2075 Node *arg = call->in(i)->uncast();
2076
2077 if (at->isa_oopptr() != NULL &&
2078 ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
2079
2080 bool global_escapes = false;
2081 bool fields_escapes = false;
2082 if (!call_analyzer->is_arg_stack(k)) {
2083 // The argument global escapes, mark everything it could point to
2084 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2085 global_escapes = true;
2086 } else {
2087 if (!call_analyzer->is_arg_local(k)) {
2088 // The argument itself doesn't escape, but any fields might
2089 fields_escapes = true;
2090 }
2091 set_escape_state(arg->_idx, PointsToNode::ArgEscape);
2092 copy_dependencies = true;
2093 }
2094
2095 for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2096 uint pt = j.elem;
2097 if (global_escapes) {
2098 //The argument global escapes, mark everything it could point to
2099 set_escape_state(pt, PointsToNode::GlobalEscape);
2100 } else {
2101 if (fields_escapes) {
2102 // The argument itself doesn't escape, but any fields might
2103 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2104 }
2105 set_escape_state(pt, PointsToNode::ArgEscape);
2106 }
2107 }
2108 }
2109 }
2110 if (copy_dependencies)
2111 call_analyzer->copy_dependencies(_compile->dependencies());
2112 break;
2113 }
2114 }
2115
2116 default:
2117 // Fall-through here if not a Java method or no analyzer information
2118 // or some other type of call, assume the worst case: all arguments
2119 // globally escape.
2120 {
2121 // adjust escape state for outgoing arguments
2122 const TypeTuple * d = call->tf()->domain();
2123 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2124 const Type* at = d->field_at(i);
2125 if (at->isa_oopptr() != NULL) {
2126 Node *arg = call->in(i)->uncast();
2127 set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2128 for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2129 uint pt = j.elem;
2130 set_escape_state(pt, PointsToNode::GlobalEscape);
2131 }
2132 }
2133 }
2134 }
2135 }
2136 }
2137 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
2138 CallNode *call = resproj->in(0)->as_Call();
2139 uint call_idx = call->_idx;
2140 uint resproj_idx = resproj->_idx;
2141
2142 switch (call->Opcode()) {
2143 case Op_Allocate:
2144 {
2145 Node *k = call->in(AllocateNode::KlassNode);
2146 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2147 assert(kt != NULL, "TypeKlassPtr required.");
2148 ciKlass* cik = kt->klass();
2149
2150 PointsToNode::EscapeState es;
2151 uint edge_to;
2152 if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2153 !cik->is_instance_klass() || // StressReflectiveCode
2154 cik->as_instance_klass()->has_finalizer()) {
2155 es = PointsToNode::GlobalEscape;
2156 edge_to = _phantom_object; // Could not be worse
2157 } else {
2158 es = PointsToNode::NoEscape;
2159 edge_to = call_idx;
2160 }
2161 set_escape_state(call_idx, es);
2162 add_pointsto_edge(resproj_idx, edge_to);
2163 _processed.set(resproj_idx);
2164 break;
2165 }
2166
2167 case Op_AllocateArray:
2168 {
2169
2170 Node *k = call->in(AllocateNode::KlassNode);
2171 const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2172 assert(kt != NULL, "TypeKlassPtr required.");
2173 ciKlass* cik = kt->klass();
2174
2175 PointsToNode::EscapeState es;
2176 uint edge_to;
2177 if (!cik->is_array_klass()) { // StressReflectiveCode
2178 es = PointsToNode::GlobalEscape;
2179 edge_to = _phantom_object;
2180 } else {
2181 es = PointsToNode::NoEscape;
2182 edge_to = call_idx;
2183 int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2184 if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2185 // Not scalar replaceable if the length is not constant or too big.
2186 es = PointsToNode::ControlEscape;
2187 }
2188 }
2189 set_escape_state(call_idx, es);
2190 add_pointsto_edge(resproj_idx, edge_to);
2191 _processed.set(resproj_idx);
2192 break;
2193 }
2194
2195 case Op_CallStaticJava:
2196 // For a static call, we know exactly what method is being called.
2197 // Use bytecode estimator to record whether the call's return value escapes
2198 {
2199 bool done = true;
2200 const TypeTuple *r = call->tf()->range();
2201 const Type* ret_type = NULL;
2202
2203 if (r->cnt() > TypeFunc::Parms)
2204 ret_type = r->field_at(TypeFunc::Parms);
2205
2206 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2207 // _multianewarray functions return a TypeRawPtr.
2208 if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2209 _processed.set(resproj_idx);
2210 break; // doesn't return a pointer type
2211 }
2212 ciMethod *meth = call->as_CallJava()->method();
2213 const TypeTuple * d = call->tf()->domain();
2214 if (meth == NULL) {
2215 // not a Java method, assume global escape
2216 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2217 add_pointsto_edge(resproj_idx, _phantom_object);
2218 } else {
2219 BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2220 bool copy_dependencies = false;
2221
2222 if (call_analyzer->is_return_allocated()) {
2223 // Returns a newly allocated unescaped object, simply
2224 // update dependency information.
2225 // Mark it as ControlEscape so that objects referenced by
2226 // it's fields will be marked as ControlEscape at least.
2227 set_escape_state(call_idx, PointsToNode::ControlEscape);
2228 add_pointsto_edge(resproj_idx, call_idx);
2229 copy_dependencies = true;
2230 } else if (call_analyzer->is_return_local()) {
2231 // determine whether any arguments are returned
2232 set_escape_state(call_idx, PointsToNode::ArgEscape);
2233 bool ret_arg = false;
2234 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2235 const Type* at = d->field_at(i);
2236
2237 if (at->isa_oopptr() != NULL) {
2238 Node *arg = call->in(i)->uncast();
2239
2240 if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2241 ret_arg = true;
2242 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2243 if (arg_esp->node_type() == PointsToNode::UnknownType)
2244 done = false;
2245 else if (arg_esp->node_type() == PointsToNode::JavaObject)
2246 add_pointsto_edge(resproj_idx, arg->_idx);
2247 else
2248 add_deferred_edge(resproj_idx, arg->_idx);
2249 }
2250 }
2251 }
2252 if (done && !ret_arg) {
2253 // Returns unknown object.
2254 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2255 add_pointsto_edge(resproj_idx, _phantom_object);
2256 }
2257 if (done) {
2258 copy_dependencies = true;
2259 }
2260 } else {
2261 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2262 add_pointsto_edge(resproj_idx, _phantom_object);
2263 }
2264 if (copy_dependencies)
2265 call_analyzer->copy_dependencies(_compile->dependencies());
2266 }
2267 if (done)
2268 _processed.set(resproj_idx);
2269 break;
2270 }
2271
2272 default:
2273 // Some other type of call, assume the worst case that the
2274 // returned value, if any, globally escapes.
2275 {
2276 const TypeTuple *r = call->tf()->range();
2277 if (r->cnt() > TypeFunc::Parms) {
2278 const Type* ret_type = r->field_at(TypeFunc::Parms);
2279
2280 // Note: we use isa_ptr() instead of isa_oopptr() here because the
2281 // _multianewarray functions return a TypeRawPtr.
2282 if (ret_type->isa_ptr() != NULL) {
2283 set_escape_state(call_idx, PointsToNode::GlobalEscape);
2284 add_pointsto_edge(resproj_idx, _phantom_object);
2285 }
2286 }
2287 _processed.set(resproj_idx);
2288 }
2289 }
2290 }
2291
2292 // Populate Connection Graph with Ideal nodes and create simple
2293 // connection graph edges (do not need to check the node_type of inputs
2294 // or to call PointsTo() to walk the connection graph).
2295 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2296 if (_processed.test(n->_idx))
2297 return; // No need to redefine node's state.
2298
2299 if (n->is_Call()) {
2300 // Arguments to allocation and locking don't escape.
2301 if (n->is_Allocate()) {
2302 add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2303 record_for_optimizer(n);
2304 } else if (n->is_Lock() || n->is_Unlock()) {
2305 // Put Lock and Unlock nodes on IGVN worklist to process them during
2306 // the first IGVN optimization when escape information is still available.
2307 record_for_optimizer(n);
2308 _processed.set(n->_idx);
2309 } else {
2310 // Don't mark as processed since call's arguments have to be processed.
2311 PointsToNode::NodeType nt = PointsToNode::UnknownType;
2312 PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2313
2314 // Check if a call returns an object.
2315 const TypeTuple *r = n->as_Call()->tf()->range();
2316 if (r->cnt() > TypeFunc::Parms &&
2317 r->field_at(TypeFunc::Parms)->isa_ptr() &&
2318 n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2319 nt = PointsToNode::JavaObject;
2320 if (!n->is_CallStaticJava()) {
2321 // Since the called mathod is statically unknown assume
2322 // the worst case that the returned value globally escapes.
2323 es = PointsToNode::GlobalEscape;
2324 }
2325 }
2326 add_node(n, nt, es, false);
2327 }
2328 return;
2329 }
2330
2331 // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2332 // ThreadLocal has RawPrt type.
2333 switch (n->Opcode()) {
2334 case Op_AddP:
2335 {
2336 add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
2337 break;
2338 }
2339 case Op_CastX2P:
2340 { // "Unsafe" memory access.
2341 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2342 break;
2343 }
2344 case Op_CastPP:
2345 case Op_CheckCastPP:
2346 case Op_EncodeP:
2347 case Op_DecodeN:
2348 {
2349 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2350 int ti = n->in(1)->_idx;
2351 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2352 if (nt == PointsToNode::UnknownType) {
2353 _delayed_worklist.push(n); // Process it later.
2354 break;
2355 } else if (nt == PointsToNode::JavaObject) {
2356 add_pointsto_edge(n->_idx, ti);
2357 } else {
2358 add_deferred_edge(n->_idx, ti);
2359 }
2360 _processed.set(n->_idx);
2361 break;
2362 }
2363 case Op_ConP:
2364 {
2365 // assume all pointer constants globally escape except for null
2366 PointsToNode::EscapeState es;
2367 if (phase->type(n) == TypePtr::NULL_PTR)
2368 es = PointsToNode::NoEscape;
2369 else
2370 es = PointsToNode::GlobalEscape;
2371
2372 add_node(n, PointsToNode::JavaObject, es, true);
2373 break;
2374 }
2375 case Op_ConN:
2376 {
2377 // assume all narrow oop constants globally escape except for null
2378 PointsToNode::EscapeState es;
2379 if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2380 es = PointsToNode::NoEscape;
2381 else
2382 es = PointsToNode::GlobalEscape;
2383
2384 add_node(n, PointsToNode::JavaObject, es, true);
2385 break;
2386 }
2387 case Op_CreateEx:
2388 {
2389 // assume that all exception objects globally escape
2390 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2391 break;
2392 }
2393 case Op_LoadKlass:
2394 case Op_LoadNKlass:
2395 {
2396 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2397 break;
2398 }
2399 case Op_LoadP:
2400 case Op_LoadN:
2401 {
2402 const Type *t = phase->type(n);
2403 if (t->make_ptr() == NULL) {
2404 _processed.set(n->_idx);
2405 return;
2406 }
2407 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2408 break;
2409 }
2410 case Op_Parm:
2411 {
2412 _processed.set(n->_idx); // No need to redefine it state.
2413 uint con = n->as_Proj()->_con;
2414 if (con < TypeFunc::Parms)
2415 return;
2416 const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2417 if (t->isa_ptr() == NULL)
2418 return;
2419 // We have to assume all input parameters globally escape
2420 // (Note: passing 'false' since _processed is already set).
2421 add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2422 break;
2423 }
2424 case Op_Phi:
2425 {
2426 const Type *t = n->as_Phi()->type();
2427 if (t->make_ptr() == NULL) {
2428 // nothing to do if not an oop or narrow oop
2429 _processed.set(n->_idx);
2430 return;
2431 }
2432 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2433 uint i;
2434 for (i = 1; i < n->req() ; i++) {
2435 Node* in = n->in(i);
2436 if (in == NULL)
2437 continue; // ignore NULL
2438 in = in->uncast();
2439 if (in->is_top() || in == n)
2440 continue; // ignore top or inputs which go back this node
2441 int ti = in->_idx;
2442 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2443 if (nt == PointsToNode::UnknownType) {
2444 break;
2445 } else if (nt == PointsToNode::JavaObject) {
2446 add_pointsto_edge(n->_idx, ti);
2447 } else {
2448 add_deferred_edge(n->_idx, ti);
2449 }
2450 }
2451 if (i >= n->req())
2452 _processed.set(n->_idx);
2453 else
2454 _delayed_worklist.push(n);
2455 break;
2456 }
2457 case Op_Proj:
2458 {
2459 // we are only interested in the oop result projection from a call
2460 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2461 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2462 assert(r->cnt() > TypeFunc::Parms, "sanity");
2463 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2464 add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2465 int ti = n->in(0)->_idx;
2466 // The call may not be registered yet (since not all its inputs are registered)
2467 // if this is the projection from backbranch edge of Phi.
2468 if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2469 process_call_result(n->as_Proj(), phase);
2470 }
2471 if (!_processed.test(n->_idx)) {
2472 // The call's result may need to be processed later if the call
2473 // returns it's argument and the argument is not processed yet.
2474 _delayed_worklist.push(n);
2475 }
2476 break;
2477 }
2478 }
2479 _processed.set(n->_idx);
2480 break;
2481 }
2482 case Op_Return:
2483 {
2484 if( n->req() > TypeFunc::Parms &&
2485 phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2486 // Treat Return value as LocalVar with GlobalEscape escape state.
2487 add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2488 int ti = n->in(TypeFunc::Parms)->_idx;
2489 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2490 if (nt == PointsToNode::UnknownType) {
2491 _delayed_worklist.push(n); // Process it later.
2492 break;
2493 } else if (nt == PointsToNode::JavaObject) {
2494 add_pointsto_edge(n->_idx, ti);
2495 } else {
2496 add_deferred_edge(n->_idx, ti);
2497 }
2498 }
2499 _processed.set(n->_idx);
2500 break;
2501 }
2502 case Op_StoreP:
2503 case Op_StoreN:
2504 {
2505 const Type *adr_type = phase->type(n->in(MemNode::Address));
2506 adr_type = adr_type->make_ptr();
2507 if (adr_type->isa_oopptr()) {
2508 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2509 } else {
2510 Node* adr = n->in(MemNode::Address);
2511 if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2512 adr->in(AddPNode::Address)->is_Proj() &&
2513 adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2514 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2515 // We are computing a raw address for a store captured
2516 // by an Initialize compute an appropriate address type.
2517 int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2518 assert(offs != Type::OffsetBot, "offset must be a constant");
2519 } else {
2520 _processed.set(n->_idx);
2521 return;
2522 }
2523 }
2524 break;
2525 }
2526 case Op_StorePConditional:
2527 case Op_CompareAndSwapP:
2528 case Op_CompareAndSwapN:
2529 {
2530 const Type *adr_type = phase->type(n->in(MemNode::Address));
2531 adr_type = adr_type->make_ptr();
2532 if (adr_type->isa_oopptr()) {
2533 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2534 } else {
2535 _processed.set(n->_idx);
2536 return;
2537 }
2538 break;
2539 }
2540 case Op_AryEq:
2541 case Op_StrComp:
2542 case Op_StrEquals:
2543 case Op_StrIndexOf:
2544 {
2545 // char[] arrays passed to string intrinsics are not scalar replaceable.
2546 add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2547 break;
2548 }
2549 case Op_ThreadLocal:
2550 {
2551 add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2552 break;
2553 }
2554 default:
2555 ;
2556 // nothing to do
2557 }
2558 return;
2559 }
2560
2561 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2562 uint n_idx = n->_idx;
2563 assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2564
2565 // Don't set processed bit for AddP, LoadP, StoreP since
2566 // they may need more then one pass to process.
2567 // Also don't mark as processed Call nodes since their
2568 // arguments may need more then one pass to process.
2569 if (_processed.test(n_idx))
2570 return; // No need to redefine node's state.
2571
2572 if (n->is_Call()) {
2573 CallNode *call = n->as_Call();
2574 process_call_arguments(call, phase);
2575 return;
2576 }
2577
2578 switch (n->Opcode()) {
2579 case Op_AddP:
2580 {
2581 Node *base = get_addp_base(n);
2582 // Create a field edge to this node from everything base could point to.
2583 for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
2584 uint pt = i.elem;
2585 add_field_edge(pt, n_idx, address_offset(n, phase));
2586 }
2587 break;
2588 }
2589 case Op_CastX2P:
2590 {
2591 assert(false, "Op_CastX2P");
2592 break;
2593 }
2594 case Op_CastPP:
2595 case Op_CheckCastPP:
2596 case Op_EncodeP:
2597 case Op_DecodeN:
2598 {
2599 int ti = n->in(1)->_idx;
2600 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2601 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2602 add_pointsto_edge(n_idx, ti);
2603 } else {
2604 add_deferred_edge(n_idx, ti);
2605 }
2606 _processed.set(n_idx);
2607 break;
2608 }
2609 case Op_ConP:
2610 {
2611 assert(false, "Op_ConP");
2612 break;
2613 }
2614 case Op_ConN:
2615 {
2616 assert(false, "Op_ConN");
2617 break;
2618 }
2619 case Op_CreateEx:
2620 {
2621 assert(false, "Op_CreateEx");
2622 break;
2623 }
2624 case Op_LoadKlass:
2625 case Op_LoadNKlass:
2626 {
2627 assert(false, "Op_LoadKlass");
2628 break;
2629 }
2630 case Op_LoadP:
2631 case Op_LoadN:
2632 {
2633 const Type *t = phase->type(n);
2634 #ifdef ASSERT
2635 if (t->make_ptr() == NULL)
2636 assert(false, "Op_LoadP");
2637 #endif
2638
2639 Node* adr = n->in(MemNode::Address)->uncast();
2640 Node* adr_base;
2641 if (adr->is_AddP()) {
2642 adr_base = get_addp_base(adr);
2643 } else {
2644 adr_base = adr;
2645 }
2646
2647 // For everything "adr_base" could point to, create a deferred edge from
2648 // this node to each field with the same offset.
2649 int offset = address_offset(adr, phase);
2650 for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
2651 uint pt = i.elem;
2652 add_deferred_edge_to_fields(n_idx, pt, offset);
2653 }
2654 break;
2655 }
2656 case Op_Parm:
2657 {
2658 assert(false, "Op_Parm");
2659 break;
2660 }
2661 case Op_Phi:
2662 {
2663 #ifdef ASSERT
2664 const Type *t = n->as_Phi()->type();
2665 if (t->make_ptr() == NULL)
2666 assert(false, "Op_Phi");
2667 #endif
2668 for (uint i = 1; i < n->req() ; i++) {
2669 Node* in = n->in(i);
2670 if (in == NULL)
2671 continue; // ignore NULL
2672 in = in->uncast();
2673 if (in->is_top() || in == n)
2674 continue; // ignore top or inputs which go back this node
2675 int ti = in->_idx;
2676 PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2677 assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2678 if (nt == PointsToNode::JavaObject) {
2679 add_pointsto_edge(n_idx, ti);
2680 } else {
2681 add_deferred_edge(n_idx, ti);
2682 }
2683 }
2684 _processed.set(n_idx);
2685 break;
2686 }
2687 case Op_Proj:
2688 {
2689 // we are only interested in the oop result projection from a call
2690 if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2691 assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
2692 "all nodes should be registered");
2693 const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2694 assert(r->cnt() > TypeFunc::Parms, "sanity");
2695 if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2696 process_call_result(n->as_Proj(), phase);
2697 assert(_processed.test(n_idx), "all call results should be processed");
2698 break;
2699 }
2700 }
2701 assert(false, "Op_Proj");
2702 break;
2703 }
2704 case Op_Return:
2705 {
2706 #ifdef ASSERT
2707 if( n->req() <= TypeFunc::Parms ||
2708 !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2709 assert(false, "Op_Return");
2710 }
2711 #endif
2712 int ti = n->in(TypeFunc::Parms)->_idx;
2713 assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
2714 if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2715 add_pointsto_edge(n_idx, ti);
2716 } else {
2717 add_deferred_edge(n_idx, ti);
2718 }
2719 _processed.set(n_idx);
2720 break;
2721 }
2722 case Op_StoreP:
2723 case Op_StoreN:
2724 case Op_StorePConditional:
2725 case Op_CompareAndSwapP:
2726 case Op_CompareAndSwapN:
2727 {
2728 Node *adr = n->in(MemNode::Address);
2729 const Type *adr_type = phase->type(adr)->make_ptr();
2730 #ifdef ASSERT
2731 if (!adr_type->isa_oopptr())
2732 assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2733 #endif
2734
2735 assert(adr->is_AddP(), "expecting an AddP");
2736 Node *adr_base = get_addp_base(adr);
2737 Node *val = n->in(MemNode::ValueIn)->uncast();
2738 // For everything "adr_base" could point to, create a deferred edge
2739 // to "val" from each field with the same offset.
2740 for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
2741 uint pt = i.elem;
2742 add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2743 }
2744 break;
2745 }
2746 case Op_AryEq:
2747 case Op_StrComp:
2748 case Op_StrEquals:
2749 case Op_StrIndexOf:
2750 {
2751 // char[] arrays passed to string intrinsic do not escape but
2752 // they are not scalar replaceable. Adjust escape state for them.
2753 // Start from in(2) edge since in(1) is memory edge.
2754 for (uint i = 2; i < n->req(); i++) {
2755 Node* adr = n->in(i)->uncast();
2756 const Type *at = phase->type(adr);
2757 if (!adr->is_top() && at->isa_ptr()) {
2758 assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
2759 at->isa_ptr() != NULL, "expecting an Ptr");
2760 if (adr->is_AddP()) {
2761 adr = get_addp_base(adr);
2762 }
2763 // Mark as ArgEscape everything "adr" could point to.
2764 set_escape_state(adr->_idx, PointsToNode::ArgEscape);
2765 }
2766 }
2767 _processed.set(n_idx);
2768 break;
2769 }
2770 case Op_ThreadLocal:
2771 {
2772 assert(false, "Op_ThreadLocal");
2773 break;
2774 }
2775 default:
2776 // This method should be called only for EA specific nodes.
2777 ShouldNotReachHere();
2778 }
2779 }
2780
2781 #ifndef PRODUCT
2782 void ConnectionGraph::dump() {
2783 bool first = true;
2784
2785 uint size = nodes_size();
2786 for (uint ni = 0; ni < size; ni++) {
2787 PointsToNode *ptn = ptnode_adr(ni);
2788 PointsToNode::NodeType ptn_type = ptn->node_type();
2789
2790 if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2791 continue;
2792 PointsToNode::EscapeState es = escape_state(ptn->_node);
2793 if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2794 if (first) {
2795 tty->cr();
2796 tty->print("======== Connection graph for ");
2797 _compile->method()->print_short_name();
2798 tty->cr();
2799 first = false;
2800 }
2801 tty->print("%6d ", ni);
2802 ptn->dump();
2803 // Print all locals which reference this allocation
2804 for (uint li = ni; li < size; li++) {
2805 PointsToNode *ptn_loc = ptnode_adr(li);
2806 PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2807 if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2808 ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2809 ptnode_adr(li)->dump(false);
2810 }
2811 }
2812 if (Verbose) {
2813 // Print all fields which reference this allocation
2814 for (uint i = 0; i < ptn->edge_count(); i++) {
2815 uint ei = ptn->edge_target(i);
2816 ptnode_adr(ei)->dump(false);
2817 }
2818 }
2819 tty->cr();
2820 }
2821 }
2822 }
2823 #endif