escape.cpp revision 1472:c18cbe5936b8
1/*
2 * Copyright (c) 2005, 2009, 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 "incls/_precompiled.incl"
26#include "incls/_escape.cpp.incl"
27
28void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
29  uint v = (targIdx << EdgeShift) + ((uint) et);
30  if (_edges == NULL) {
31     Arena *a = Compile::current()->comp_arena();
32    _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
33  }
34  _edges->append_if_missing(v);
35}
36
37void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
38  uint v = (targIdx << EdgeShift) + ((uint) et);
39
40  _edges->remove(v);
41}
42
43#ifndef PRODUCT
44static const char *node_type_names[] = {
45  "UnknownType",
46  "JavaObject",
47  "LocalVar",
48  "Field"
49};
50
51static const char *esc_names[] = {
52  "UnknownEscape",
53  "NoEscape",
54  "ArgEscape",
55  "GlobalEscape"
56};
57
58static const char *edge_type_suffix[] = {
59 "?", // UnknownEdge
60 "P", // PointsToEdge
61 "D", // DeferredEdge
62 "F"  // FieldEdge
63};
64
65void PointsToNode::dump(bool print_state) const {
66  NodeType nt = node_type();
67  tty->print("%s ", node_type_names[(int) nt]);
68  if (print_state) {
69    EscapeState es = escape_state();
70    tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
71  }
72  tty->print("[[");
73  for (uint i = 0; i < edge_count(); i++) {
74    tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
75  }
76  tty->print("]]  ");
77  if (_node == NULL)
78    tty->print_cr("<null>");
79  else
80    _node->dump();
81}
82#endif
83
84ConnectionGraph::ConnectionGraph(Compile * C) :
85  _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
86  _processed(C->comp_arena()),
87  _collecting(true),
88  _compile(C),
89  _node_map(C->comp_arena()) {
90
91  _phantom_object = C->top()->_idx,
92  add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
93
94  // Add ConP(#NULL) and ConN(#NULL) nodes.
95  PhaseGVN* igvn = C->initial_gvn();
96  Node* oop_null = igvn->zerocon(T_OBJECT);
97  _oop_null = oop_null->_idx;
98  assert(_oop_null < C->unique(), "should be created already");
99  add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
100
101  if (UseCompressedOops) {
102    Node* noop_null = igvn->zerocon(T_NARROWOOP);
103    _noop_null = noop_null->_idx;
104    assert(_noop_null < C->unique(), "should be created already");
105    add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
106  }
107}
108
109void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
110  PointsToNode *f = ptnode_adr(from_i);
111  PointsToNode *t = ptnode_adr(to_i);
112
113  assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
114  assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
115  assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
116  f->add_edge(to_i, PointsToNode::PointsToEdge);
117}
118
119void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
120  PointsToNode *f = ptnode_adr(from_i);
121  PointsToNode *t = ptnode_adr(to_i);
122
123  assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
124  assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
125  assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
126  // don't add a self-referential edge, this can occur during removal of
127  // deferred edges
128  if (from_i != to_i)
129    f->add_edge(to_i, PointsToNode::DeferredEdge);
130}
131
132int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
133  const Type *adr_type = phase->type(adr);
134  if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
135      adr->in(AddPNode::Address)->is_Proj() &&
136      adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
137    // We are computing a raw address for a store captured by an Initialize
138    // compute an appropriate address type. AddP cases #3 and #5 (see below).
139    int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
140    assert(offs != Type::OffsetBot ||
141           adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
142           "offset must be a constant or it is initialization of array");
143    return offs;
144  }
145  const TypePtr *t_ptr = adr_type->isa_ptr();
146  assert(t_ptr != NULL, "must be a pointer type");
147  return t_ptr->offset();
148}
149
150void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
151  PointsToNode *f = ptnode_adr(from_i);
152  PointsToNode *t = ptnode_adr(to_i);
153
154  assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
155  assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
156  assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
157  assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
158  t->set_offset(offset);
159
160  f->add_edge(to_i, PointsToNode::FieldEdge);
161}
162
163void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
164  PointsToNode *npt = ptnode_adr(ni);
165  PointsToNode::EscapeState old_es = npt->escape_state();
166  if (es > old_es)
167    npt->set_escape_state(es);
168}
169
170void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
171                               PointsToNode::EscapeState es, bool done) {
172  PointsToNode* ptadr = ptnode_adr(n->_idx);
173  ptadr->_node = n;
174  ptadr->set_node_type(nt);
175
176  // inline set_escape_state(idx, es);
177  PointsToNode::EscapeState old_es = ptadr->escape_state();
178  if (es > old_es)
179    ptadr->set_escape_state(es);
180
181  if (done)
182    _processed.set(n->_idx);
183}
184
185PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n, PhaseTransform *phase) {
186  uint idx = n->_idx;
187  PointsToNode::EscapeState es;
188
189  // If we are still collecting or there were no non-escaping allocations
190  // we don't know the answer yet
191  if (_collecting)
192    return PointsToNode::UnknownEscape;
193
194  // if the node was created after the escape computation, return
195  // UnknownEscape
196  if (idx >= nodes_size())
197    return PointsToNode::UnknownEscape;
198
199  es = ptnode_adr(idx)->escape_state();
200
201  // if we have already computed a value, return it
202  if (es != PointsToNode::UnknownEscape &&
203      ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
204    return es;
205
206  // PointsTo() calls n->uncast() which can return a new ideal node.
207  if (n->uncast()->_idx >= nodes_size())
208    return PointsToNode::UnknownEscape;
209
210  // compute max escape state of anything this node could point to
211  VectorSet ptset(Thread::current()->resource_area());
212  PointsTo(ptset, n, phase);
213  for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
214    uint pt = i.elem;
215    PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
216    if (pes > es)
217      es = pes;
218  }
219  // cache the computed escape state
220  assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
221  ptnode_adr(idx)->set_escape_state(es);
222  return es;
223}
224
225void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n, PhaseTransform *phase) {
226  VectorSet visited(Thread::current()->resource_area());
227  GrowableArray<uint>  worklist;
228
229#ifdef ASSERT
230  Node *orig_n = n;
231#endif
232
233  n = n->uncast();
234  PointsToNode* npt = ptnode_adr(n->_idx);
235
236  // If we have a JavaObject, return just that object
237  if (npt->node_type() == PointsToNode::JavaObject) {
238    ptset.set(n->_idx);
239    return;
240  }
241#ifdef ASSERT
242  if (npt->_node == NULL) {
243    if (orig_n != n)
244      orig_n->dump();
245    n->dump();
246    assert(npt->_node != NULL, "unregistered node");
247  }
248#endif
249  worklist.push(n->_idx);
250  while(worklist.length() > 0) {
251    int ni = worklist.pop();
252    if (visited.test_set(ni))
253      continue;
254
255    PointsToNode* pn = ptnode_adr(ni);
256    // ensure that all inputs of a Phi have been processed
257    assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
258
259    int edges_processed = 0;
260    uint e_cnt = pn->edge_count();
261    for (uint e = 0; e < e_cnt; e++) {
262      uint etgt = pn->edge_target(e);
263      PointsToNode::EdgeType et = pn->edge_type(e);
264      if (et == PointsToNode::PointsToEdge) {
265        ptset.set(etgt);
266        edges_processed++;
267      } else if (et == PointsToNode::DeferredEdge) {
268        worklist.push(etgt);
269        edges_processed++;
270      } else {
271        assert(false,"neither PointsToEdge or DeferredEdge");
272      }
273    }
274    if (edges_processed == 0) {
275      // no deferred or pointsto edges found.  Assume the value was set
276      // outside this method.  Add the phantom object to the pointsto set.
277      ptset.set(_phantom_object);
278    }
279  }
280}
281
282void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
283  // This method is most expensive during ConnectionGraph construction.
284  // Reuse vectorSet and an additional growable array for deferred edges.
285  deferred_edges->clear();
286  visited->Clear();
287
288  visited->set(ni);
289  PointsToNode *ptn = ptnode_adr(ni);
290
291  // Mark current edges as visited and move deferred edges to separate array.
292  for (uint i = 0; i < ptn->edge_count(); ) {
293    uint t = ptn->edge_target(i);
294#ifdef ASSERT
295    assert(!visited->test_set(t), "expecting no duplications");
296#else
297    visited->set(t);
298#endif
299    if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
300      ptn->remove_edge(t, PointsToNode::DeferredEdge);
301      deferred_edges->append(t);
302    } else {
303      i++;
304    }
305  }
306  for (int next = 0; next < deferred_edges->length(); ++next) {
307    uint t = deferred_edges->at(next);
308    PointsToNode *ptt = ptnode_adr(t);
309    uint e_cnt = ptt->edge_count();
310    for (uint e = 0; e < e_cnt; e++) {
311      uint etgt = ptt->edge_target(e);
312      if (visited->test_set(etgt))
313        continue;
314
315      PointsToNode::EdgeType et = ptt->edge_type(e);
316      if (et == PointsToNode::PointsToEdge) {
317        add_pointsto_edge(ni, etgt);
318        if(etgt == _phantom_object) {
319          // Special case - field set outside (globally escaping).
320          ptn->set_escape_state(PointsToNode::GlobalEscape);
321        }
322      } else if (et == PointsToNode::DeferredEdge) {
323        deferred_edges->append(etgt);
324      } else {
325        assert(false,"invalid connection graph");
326      }
327    }
328  }
329}
330
331
332//  Add an edge to node given by "to_i" from any field of adr_i whose offset
333//  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
334//  a pointsto edge is added if it is a JavaObject
335
336void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
337  PointsToNode* an = ptnode_adr(adr_i);
338  PointsToNode* to = ptnode_adr(to_i);
339  bool deferred = (to->node_type() == PointsToNode::LocalVar);
340
341  for (uint fe = 0; fe < an->edge_count(); fe++) {
342    assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
343    int fi = an->edge_target(fe);
344    PointsToNode* pf = ptnode_adr(fi);
345    int po = pf->offset();
346    if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
347      if (deferred)
348        add_deferred_edge(fi, to_i);
349      else
350        add_pointsto_edge(fi, to_i);
351    }
352  }
353}
354
355// Add a deferred  edge from node given by "from_i" to any field of adr_i
356// whose offset matches "offset".
357void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
358  PointsToNode* an = ptnode_adr(adr_i);
359  for (uint fe = 0; fe < an->edge_count(); fe++) {
360    assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
361    int fi = an->edge_target(fe);
362    PointsToNode* pf = ptnode_adr(fi);
363    int po = pf->offset();
364    if (pf->edge_count() == 0) {
365      // we have not seen any stores to this field, assume it was set outside this method
366      add_pointsto_edge(fi, _phantom_object);
367    }
368    if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
369      add_deferred_edge(from_i, fi);
370    }
371  }
372}
373
374// Helper functions
375
376static Node* get_addp_base(Node *addp) {
377  assert(addp->is_AddP(), "must be AddP");
378  //
379  // AddP cases for Base and Address inputs:
380  // case #1. Direct object's field reference:
381  //     Allocate
382  //       |
383  //     Proj #5 ( oop result )
384  //       |
385  //     CheckCastPP (cast to instance type)
386  //      | |
387  //     AddP  ( base == address )
388  //
389  // case #2. Indirect object's field reference:
390  //      Phi
391  //       |
392  //     CastPP (cast to instance type)
393  //      | |
394  //     AddP  ( base == address )
395  //
396  // case #3. Raw object's field reference for Initialize node:
397  //      Allocate
398  //        |
399  //      Proj #5 ( oop result )
400  //  top   |
401  //     \  |
402  //     AddP  ( base == top )
403  //
404  // case #4. Array's element reference:
405  //   {CheckCastPP | CastPP}
406  //     |  | |
407  //     |  AddP ( array's element offset )
408  //     |  |
409  //     AddP ( array's offset )
410  //
411  // case #5. Raw object's field reference for arraycopy stub call:
412  //          The inline_native_clone() case when the arraycopy stub is called
413  //          after the allocation before Initialize and CheckCastPP nodes.
414  //      Allocate
415  //        |
416  //      Proj #5 ( oop result )
417  //       | |
418  //       AddP  ( base == address )
419  //
420  // case #6. Constant Pool, ThreadLocal, CastX2P or
421  //          Raw object's field reference:
422  //      {ConP, ThreadLocal, CastX2P, raw Load}
423  //  top   |
424  //     \  |
425  //     AddP  ( base == top )
426  //
427  // case #7. Klass's field reference.
428  //      LoadKlass
429  //       | |
430  //       AddP  ( base == address )
431  //
432  // case #8. narrow Klass's field reference.
433  //      LoadNKlass
434  //       |
435  //      DecodeN
436  //       | |
437  //       AddP  ( base == address )
438  //
439  Node *base = addp->in(AddPNode::Base)->uncast();
440  if (base->is_top()) { // The AddP case #3 and #6.
441    base = addp->in(AddPNode::Address)->uncast();
442    while (base->is_AddP()) {
443      // Case #6 (unsafe access) may have several chained AddP nodes.
444      assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
445      base = base->in(AddPNode::Address)->uncast();
446    }
447    assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
448           base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
449           (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
450           (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
451  }
452  return base;
453}
454
455static Node* find_second_addp(Node* addp, Node* n) {
456  assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
457
458  Node* addp2 = addp->raw_out(0);
459  if (addp->outcnt() == 1 && addp2->is_AddP() &&
460      addp2->in(AddPNode::Base) == n &&
461      addp2->in(AddPNode::Address) == addp) {
462
463    assert(addp->in(AddPNode::Base) == n, "expecting the same base");
464    //
465    // Find array's offset to push it on worklist first and
466    // as result process an array's element offset first (pushed second)
467    // to avoid CastPP for the array's offset.
468    // Otherwise the inserted CastPP (LocalVar) will point to what
469    // the AddP (Field) points to. Which would be wrong since
470    // the algorithm expects the CastPP has the same point as
471    // as AddP's base CheckCastPP (LocalVar).
472    //
473    //    ArrayAllocation
474    //     |
475    //    CheckCastPP
476    //     |
477    //    memProj (from ArrayAllocation CheckCastPP)
478    //     |  ||
479    //     |  ||   Int (element index)
480    //     |  ||    |   ConI (log(element size))
481    //     |  ||    |   /
482    //     |  ||   LShift
483    //     |  ||  /
484    //     |  AddP (array's element offset)
485    //     |  |
486    //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
487    //     | / /
488    //     AddP (array's offset)
489    //      |
490    //     Load/Store (memory operation on array's element)
491    //
492    return addp2;
493  }
494  return NULL;
495}
496
497//
498// Adjust the type and inputs of an AddP which computes the
499// address of a field of an instance
500//
501bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
502  const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
503  assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
504  const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
505  if (t == NULL) {
506    // We are computing a raw address for a store captured by an Initialize
507    // compute an appropriate address type (cases #3 and #5).
508    assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
509    assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
510    intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
511    assert(offs != Type::OffsetBot, "offset must be a constant");
512    t = base_t->add_offset(offs)->is_oopptr();
513  }
514  int inst_id =  base_t->instance_id();
515  assert(!t->is_known_instance() || t->instance_id() == inst_id,
516                             "old type must be non-instance or match new type");
517
518  // The type 't' could be subclass of 'base_t'.
519  // As result t->offset() could be large then base_t's size and it will
520  // cause the failure in add_offset() with narrow oops since TypeOopPtr()
521  // constructor verifies correctness of the offset.
522  //
523  // It could happened on subclass's branch (from the type profiling
524  // inlining) which was not eliminated during parsing since the exactness
525  // of the allocation type was not propagated to the subclass type check.
526  //
527  // Or the type 't' could be not related to 'base_t' at all.
528  // It could happened when CHA type is different from MDO type on a dead path
529  // (for example, from instanceof check) which is not collapsed during parsing.
530  //
531  // Do nothing for such AddP node and don't process its users since
532  // this code branch will go away.
533  //
534  if (!t->is_known_instance() &&
535      !base_t->klass()->is_subtype_of(t->klass())) {
536     return false; // bail out
537  }
538
539  const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
540  // Do NOT remove the next line: ensure a new alias index is allocated
541  // for the instance type. Note: C++ will not remove it since the call
542  // has side effect.
543  int alias_idx = _compile->get_alias_index(tinst);
544  igvn->set_type(addp, tinst);
545  // record the allocation in the node map
546  assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
547  set_map(addp->_idx, get_map(base->_idx));
548
549  // Set addp's Base and Address to 'base'.
550  Node *abase = addp->in(AddPNode::Base);
551  Node *adr   = addp->in(AddPNode::Address);
552  if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
553      adr->in(0)->_idx == (uint)inst_id) {
554    // Skip AddP cases #3 and #5.
555  } else {
556    assert(!abase->is_top(), "sanity"); // AddP case #3
557    if (abase != base) {
558      igvn->hash_delete(addp);
559      addp->set_req(AddPNode::Base, base);
560      if (abase == adr) {
561        addp->set_req(AddPNode::Address, base);
562      } else {
563        // AddP case #4 (adr is array's element offset AddP node)
564#ifdef ASSERT
565        const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
566        assert(adr->is_AddP() && atype != NULL &&
567               atype->instance_id() == inst_id, "array's element offset should be processed first");
568#endif
569      }
570      igvn->hash_insert(addp);
571    }
572  }
573  // Put on IGVN worklist since at least addp's type was changed above.
574  record_for_optimizer(addp);
575  return true;
576}
577
578//
579// Create a new version of orig_phi if necessary. Returns either the newly
580// created phi or an existing phi.  Sets create_new to indicate wheter  a new
581// phi was created.  Cache the last newly created phi in the node map.
582//
583PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
584  Compile *C = _compile;
585  new_created = false;
586  int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
587  // nothing to do if orig_phi is bottom memory or matches alias_idx
588  if (phi_alias_idx == alias_idx) {
589    return orig_phi;
590  }
591  // Have we recently created a Phi for this alias index?
592  PhiNode *result = get_map_phi(orig_phi->_idx);
593  if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
594    return result;
595  }
596  // Previous check may fail when the same wide memory Phi was split into Phis
597  // for different memory slices. Search all Phis for this region.
598  if (result != NULL) {
599    Node* region = orig_phi->in(0);
600    for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
601      Node* phi = region->fast_out(i);
602      if (phi->is_Phi() &&
603          C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
604        assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
605        return phi->as_Phi();
606      }
607    }
608  }
609  if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
610    if (C->do_escape_analysis() == true && !C->failing()) {
611      // Retry compilation without escape analysis.
612      // If this is the first failure, the sentinel string will "stick"
613      // to the Compile object, and the C2Compiler will see it and retry.
614      C->record_failure(C2Compiler::retry_no_escape_analysis());
615    }
616    return NULL;
617  }
618  orig_phi_worklist.append_if_missing(orig_phi);
619  const TypePtr *atype = C->get_adr_type(alias_idx);
620  result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
621  C->copy_node_notes_to(result, orig_phi);
622  igvn->set_type(result, result->bottom_type());
623  record_for_optimizer(result);
624
625  debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
626  assert(pn == NULL || pn == orig_phi, "wrong node");
627  set_map(orig_phi->_idx, result);
628  ptnode_adr(orig_phi->_idx)->_node = orig_phi;
629
630  new_created = true;
631  return result;
632}
633
634//
635// Return a new version  of Memory Phi "orig_phi" with the inputs having the
636// specified alias index.
637//
638PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
639
640  assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
641  Compile *C = _compile;
642  bool new_phi_created;
643  PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
644  if (!new_phi_created) {
645    return result;
646  }
647
648  GrowableArray<PhiNode *>  phi_list;
649  GrowableArray<uint>  cur_input;
650
651  PhiNode *phi = orig_phi;
652  uint idx = 1;
653  bool finished = false;
654  while(!finished) {
655    while (idx < phi->req()) {
656      Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
657      if (mem != NULL && mem->is_Phi()) {
658        PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
659        if (new_phi_created) {
660          // found an phi for which we created a new split, push current one on worklist and begin
661          // processing new one
662          phi_list.push(phi);
663          cur_input.push(idx);
664          phi = mem->as_Phi();
665          result = newphi;
666          idx = 1;
667          continue;
668        } else {
669          mem = newphi;
670        }
671      }
672      if (C->failing()) {
673        return NULL;
674      }
675      result->set_req(idx++, mem);
676    }
677#ifdef ASSERT
678    // verify that the new Phi has an input for each input of the original
679    assert( phi->req() == result->req(), "must have same number of inputs.");
680    assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
681#endif
682    // Check if all new phi's inputs have specified alias index.
683    // Otherwise use old phi.
684    for (uint i = 1; i < phi->req(); i++) {
685      Node* in = result->in(i);
686      assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
687    }
688    // we have finished processing a Phi, see if there are any more to do
689    finished = (phi_list.length() == 0 );
690    if (!finished) {
691      phi = phi_list.pop();
692      idx = cur_input.pop();
693      PhiNode *prev_result = get_map_phi(phi->_idx);
694      prev_result->set_req(idx++, result);
695      result = prev_result;
696    }
697  }
698  return result;
699}
700
701
702//
703// The next methods are derived from methods in MemNode.
704//
705static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *tinst) {
706  Node *mem = mmem;
707  // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally
708  // means an array I have not precisely typed yet.  Do not do any
709  // alias stuff with it any time soon.
710  if( tinst->base() != Type::AnyPtr &&
711      !(tinst->klass()->is_java_lang_Object() &&
712        tinst->offset() == Type::OffsetBot) ) {
713    mem = mmem->memory_at(alias_idx);
714    // Update input if it is progress over what we have now
715  }
716  return mem;
717}
718
719//
720// Move memory users to their memory slices.
721//
722void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
723  Compile* C = _compile;
724
725  const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
726  assert(tp != NULL, "ptr type");
727  int alias_idx = C->get_alias_index(tp);
728  int general_idx = C->get_general_index(alias_idx);
729
730  // Move users first
731  for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
732    Node* use = n->fast_out(i);
733    if (use->is_MergeMem()) {
734      MergeMemNode* mmem = use->as_MergeMem();
735      assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
736      if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
737        continue; // Nothing to do
738      }
739      // Replace previous general reference to mem node.
740      uint orig_uniq = C->unique();
741      Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
742      assert(orig_uniq == C->unique(), "no new nodes");
743      mmem->set_memory_at(general_idx, m);
744      --imax;
745      --i;
746    } else if (use->is_MemBar()) {
747      assert(!use->is_Initialize(), "initializing stores should not be moved");
748      if (use->req() > MemBarNode::Precedent &&
749          use->in(MemBarNode::Precedent) == n) {
750        // Don't move related membars.
751        record_for_optimizer(use);
752        continue;
753      }
754      tp = use->as_MemBar()->adr_type()->isa_ptr();
755      if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
756          alias_idx == general_idx) {
757        continue; // Nothing to do
758      }
759      // Move to general memory slice.
760      uint orig_uniq = C->unique();
761      Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
762      assert(orig_uniq == C->unique(), "no new nodes");
763      igvn->hash_delete(use);
764      imax -= use->replace_edge(n, m);
765      igvn->hash_insert(use);
766      record_for_optimizer(use);
767      --i;
768#ifdef ASSERT
769    } else if (use->is_Mem()) {
770      if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
771        // Don't move related cardmark.
772        continue;
773      }
774      // Memory nodes should have new memory input.
775      tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
776      assert(tp != NULL, "ptr type");
777      int idx = C->get_alias_index(tp);
778      assert(get_map(use->_idx) != NULL || idx == alias_idx,
779             "Following memory nodes should have new memory input or be on the same memory slice");
780    } else if (use->is_Phi()) {
781      // Phi nodes should be split and moved already.
782      tp = use->as_Phi()->adr_type()->isa_ptr();
783      assert(tp != NULL, "ptr type");
784      int idx = C->get_alias_index(tp);
785      assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
786    } else {
787      use->dump();
788      assert(false, "should not be here");
789#endif
790    }
791  }
792}
793
794//
795// Search memory chain of "mem" to find a MemNode whose address
796// is the specified alias index.
797//
798Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
799  if (orig_mem == NULL)
800    return orig_mem;
801  Compile* C = phase->C;
802  const TypeOopPtr *tinst = C->get_adr_type(alias_idx)->isa_oopptr();
803  bool is_instance = (tinst != NULL) && tinst->is_known_instance();
804  Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
805  Node *prev = NULL;
806  Node *result = orig_mem;
807  while (prev != result) {
808    prev = result;
809    if (result == start_mem)
810      break;  // hit one of our sentinels
811    if (result->is_Mem()) {
812      const Type *at = phase->type(result->in(MemNode::Address));
813      if (at != Type::TOP) {
814        assert (at->isa_ptr() != NULL, "pointer type required.");
815        int idx = C->get_alias_index(at->is_ptr());
816        if (idx == alias_idx)
817          break;
818      }
819      result = result->in(MemNode::Memory);
820    }
821    if (!is_instance)
822      continue;  // don't search further for non-instance types
823    // skip over a call which does not affect this memory slice
824    if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
825      Node *proj_in = result->in(0);
826      if (proj_in->is_Allocate() && proj_in->_idx == (uint)tinst->instance_id()) {
827        break;  // hit one of our sentinels
828      } else if (proj_in->is_Call()) {
829        CallNode *call = proj_in->as_Call();
830        if (!call->may_modify(tinst, phase)) {
831          result = call->in(TypeFunc::Memory);
832        }
833      } else if (proj_in->is_Initialize()) {
834        AllocateNode* alloc = proj_in->as_Initialize()->allocation();
835        // Stop if this is the initialization for the object instance which
836        // which contains this memory slice, otherwise skip over it.
837        if (alloc == NULL || alloc->_idx != (uint)tinst->instance_id()) {
838          result = proj_in->in(TypeFunc::Memory);
839        }
840      } else if (proj_in->is_MemBar()) {
841        result = proj_in->in(TypeFunc::Memory);
842      }
843    } else if (result->is_MergeMem()) {
844      MergeMemNode *mmem = result->as_MergeMem();
845      result = step_through_mergemem(mmem, alias_idx, tinst);
846      if (result == mmem->base_memory()) {
847        // Didn't find instance memory, search through general slice recursively.
848        result = mmem->memory_at(C->get_general_index(alias_idx));
849        result = find_inst_mem(result, alias_idx, orig_phis, phase);
850        if (C->failing()) {
851          return NULL;
852        }
853        mmem->set_memory_at(alias_idx, result);
854      }
855    } else if (result->is_Phi() &&
856               C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
857      Node *un = result->as_Phi()->unique_input(phase);
858      if (un != NULL) {
859        orig_phis.append_if_missing(result->as_Phi());
860        result = un;
861      } else {
862        break;
863      }
864    } else if (result->is_ClearArray()) {
865      if (!ClearArrayNode::step_through(&result, (uint)tinst->instance_id(), phase)) {
866        // Can not bypass initialization of the instance
867        // we are looking for.
868        break;
869      }
870      // Otherwise skip it (the call updated 'result' value).
871    } else if (result->Opcode() == Op_SCMemProj) {
872      assert(result->in(0)->is_LoadStore(), "sanity");
873      const Type *at = phase->type(result->in(0)->in(MemNode::Address));
874      if (at != Type::TOP) {
875        assert (at->isa_ptr() != NULL, "pointer type required.");
876        int idx = C->get_alias_index(at->is_ptr());
877        assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
878        break;
879      }
880      result = result->in(0)->in(MemNode::Memory);
881    }
882  }
883  if (result->is_Phi()) {
884    PhiNode *mphi = result->as_Phi();
885    assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
886    const TypePtr *t = mphi->adr_type();
887    if (C->get_alias_index(t) != alias_idx) {
888      // Create a new Phi with the specified alias index type.
889      result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
890    } else if (!is_instance) {
891      // Push all non-instance Phis on the orig_phis worklist to update inputs
892      // during Phase 4 if needed.
893      orig_phis.append_if_missing(mphi);
894    }
895  }
896  // the result is either MemNode, PhiNode, InitializeNode.
897  return result;
898}
899
900//
901//  Convert the types of unescaped object to instance types where possible,
902//  propagate the new type information through the graph, and update memory
903//  edges and MergeMem inputs to reflect the new type.
904//
905//  We start with allocations (and calls which may be allocations)  on alloc_worklist.
906//  The processing is done in 4 phases:
907//
908//  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
909//            types for the CheckCastPP for allocations where possible.
910//            Propagate the the new types through users as follows:
911//               casts and Phi:  push users on alloc_worklist
912//               AddP:  cast Base and Address inputs to the instance type
913//                      push any AddP users on alloc_worklist and push any memnode
914//                      users onto memnode_worklist.
915//  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
916//            search the Memory chain for a store with the appropriate type
917//            address type.  If a Phi is found, create a new version with
918//            the appropriate memory slices from each of the Phi inputs.
919//            For stores, process the users as follows:
920//               MemNode:  push on memnode_worklist
921//               MergeMem: push on mergemem_worklist
922//  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
923//            moving the first node encountered of each  instance type to the
924//            the input corresponding to its alias index.
925//            appropriate memory slice.
926//  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
927//
928// In the following example, the CheckCastPP nodes are the cast of allocation
929// results and the allocation of node 29 is unescaped and eligible to be an
930// instance type.
931//
932// We start with:
933//
934//     7 Parm #memory
935//    10  ConI  "12"
936//    19  CheckCastPP   "Foo"
937//    20  AddP  _ 19 19 10  Foo+12  alias_index=4
938//    29  CheckCastPP   "Foo"
939//    30  AddP  _ 29 29 10  Foo+12  alias_index=4
940//
941//    40  StoreP  25   7  20   ... alias_index=4
942//    50  StoreP  35  40  30   ... alias_index=4
943//    60  StoreP  45  50  20   ... alias_index=4
944//    70  LoadP    _  60  30   ... alias_index=4
945//    80  Phi     75  50  60   Memory alias_index=4
946//    90  LoadP    _  80  30   ... alias_index=4
947//   100  LoadP    _  80  20   ... alias_index=4
948//
949//
950// Phase 1 creates an instance type for node 29 assigning it an instance id of 24
951// and creating a new alias index for node 30.  This gives:
952//
953//     7 Parm #memory
954//    10  ConI  "12"
955//    19  CheckCastPP   "Foo"
956//    20  AddP  _ 19 19 10  Foo+12  alias_index=4
957//    29  CheckCastPP   "Foo"  iid=24
958//    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
959//
960//    40  StoreP  25   7  20   ... alias_index=4
961//    50  StoreP  35  40  30   ... alias_index=6
962//    60  StoreP  45  50  20   ... alias_index=4
963//    70  LoadP    _  60  30   ... alias_index=6
964//    80  Phi     75  50  60   Memory alias_index=4
965//    90  LoadP    _  80  30   ... alias_index=6
966//   100  LoadP    _  80  20   ... alias_index=4
967//
968// In phase 2, new memory inputs are computed for the loads and stores,
969// And a new version of the phi is created.  In phase 4, the inputs to
970// node 80 are updated and then the memory nodes are updated with the
971// values computed in phase 2.  This results in:
972//
973//     7 Parm #memory
974//    10  ConI  "12"
975//    19  CheckCastPP   "Foo"
976//    20  AddP  _ 19 19 10  Foo+12  alias_index=4
977//    29  CheckCastPP   "Foo"  iid=24
978//    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
979//
980//    40  StoreP  25  7   20   ... alias_index=4
981//    50  StoreP  35  7   30   ... alias_index=6
982//    60  StoreP  45  40  20   ... alias_index=4
983//    70  LoadP    _  50  30   ... alias_index=6
984//    80  Phi     75  40  60   Memory alias_index=4
985//   120  Phi     75  50  50   Memory alias_index=6
986//    90  LoadP    _ 120  30   ... alias_index=6
987//   100  LoadP    _  80  20   ... alias_index=4
988//
989void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
990  GrowableArray<Node *>  memnode_worklist;
991  GrowableArray<PhiNode *>  orig_phis;
992
993  PhaseGVN  *igvn = _compile->initial_gvn();
994  uint new_index_start = (uint) _compile->num_alias_types();
995  Arena* arena = Thread::current()->resource_area();
996  VectorSet visited(arena);
997  VectorSet ptset(arena);
998
999
1000  //  Phase 1:  Process possible allocations from alloc_worklist.
1001  //  Create instance types for the CheckCastPP for allocations where possible.
1002  //
1003  // (Note: don't forget to change the order of the second AddP node on
1004  //  the alloc_worklist if the order of the worklist processing is changed,
1005  //  see the comment in find_second_addp().)
1006  //
1007  while (alloc_worklist.length() != 0) {
1008    Node *n = alloc_worklist.pop();
1009    uint ni = n->_idx;
1010    const TypeOopPtr* tinst = NULL;
1011    if (n->is_Call()) {
1012      CallNode *alloc = n->as_Call();
1013      // copy escape information to call node
1014      PointsToNode* ptn = ptnode_adr(alloc->_idx);
1015      PointsToNode::EscapeState es = escape_state(alloc, igvn);
1016      // We have an allocation or call which returns a Java object,
1017      // see if it is unescaped.
1018      if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
1019        continue;
1020
1021      // Find CheckCastPP for the allocate or for the return value of a call
1022      n = alloc->result_cast();
1023      if (n == NULL) {            // No uses except Initialize node
1024        if (alloc->is_Allocate()) {
1025          // Set the scalar_replaceable flag for allocation
1026          // so it could be eliminated if it has no uses.
1027          alloc->as_Allocate()->_is_scalar_replaceable = true;
1028        }
1029        continue;
1030      }
1031      if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1032        assert(!alloc->is_Allocate(), "allocation should have unique type");
1033        continue;
1034      }
1035
1036      // The inline code for Object.clone() casts the allocation result to
1037      // java.lang.Object and then to the actual type of the allocated
1038      // object. Detect this case and use the second cast.
1039      // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
1040      // the allocation result is cast to java.lang.Object and then
1041      // to the actual Array type.
1042      if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
1043          && (alloc->is_AllocateArray() ||
1044              igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
1045        Node *cast2 = NULL;
1046        for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1047          Node *use = n->fast_out(i);
1048          if (use->is_CheckCastPP()) {
1049            cast2 = use;
1050            break;
1051          }
1052        }
1053        if (cast2 != NULL) {
1054          n = cast2;
1055        } else {
1056          // Non-scalar replaceable if the allocation type is unknown statically
1057          // (reflection allocation), the object can't be restored during
1058          // deoptimization without precise type.
1059          continue;
1060        }
1061      }
1062      if (alloc->is_Allocate()) {
1063        // Set the scalar_replaceable flag for allocation
1064        // so it could be eliminated.
1065        alloc->as_Allocate()->_is_scalar_replaceable = true;
1066      }
1067      set_escape_state(n->_idx, es);
1068      // in order for an object to be scalar-replaceable, it must be:
1069      //   - a direct allocation (not a call returning an object)
1070      //   - non-escaping
1071      //   - eligible to be a unique type
1072      //   - not determined to be ineligible by escape analysis
1073      assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1074             ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1075      set_map(alloc->_idx, n);
1076      set_map(n->_idx, alloc);
1077      const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1078      if (t == NULL)
1079        continue;  // not a TypeInstPtr
1080      tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1081      igvn->hash_delete(n);
1082      igvn->set_type(n,  tinst);
1083      n->raise_bottom_type(tinst);
1084      igvn->hash_insert(n);
1085      record_for_optimizer(n);
1086      if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
1087          (t->isa_instptr() || t->isa_aryptr())) {
1088
1089        // First, put on the worklist all Field edges from Connection Graph
1090        // which is more accurate then putting immediate users from Ideal Graph.
1091        for (uint e = 0; e < ptn->edge_count(); e++) {
1092          Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1093          assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
1094                 "only AddP nodes are Field edges in CG");
1095          if (use->outcnt() > 0) { // Don't process dead nodes
1096            Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1097            if (addp2 != NULL) {
1098              assert(alloc->is_AllocateArray(),"array allocation was expected");
1099              alloc_worklist.append_if_missing(addp2);
1100            }
1101            alloc_worklist.append_if_missing(use);
1102          }
1103        }
1104
1105        // An allocation may have an Initialize which has raw stores. Scan
1106        // the users of the raw allocation result and push AddP users
1107        // on alloc_worklist.
1108        Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1109        assert (raw_result != NULL, "must have an allocation result");
1110        for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1111          Node *use = raw_result->fast_out(i);
1112          if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1113            Node* addp2 = find_second_addp(use, raw_result);
1114            if (addp2 != NULL) {
1115              assert(alloc->is_AllocateArray(),"array allocation was expected");
1116              alloc_worklist.append_if_missing(addp2);
1117            }
1118            alloc_worklist.append_if_missing(use);
1119          } else if (use->is_MemBar()) {
1120            memnode_worklist.append_if_missing(use);
1121          }
1122        }
1123      }
1124    } else if (n->is_AddP()) {
1125      ptset.Clear();
1126      PointsTo(ptset, get_addp_base(n), igvn);
1127      assert(ptset.Size() == 1, "AddP address is unique");
1128      uint elem = ptset.getelem(); // Allocation node's index
1129      if (elem == _phantom_object) {
1130        assert(false, "escaped allocation");
1131        continue; // Assume the value was set outside this method.
1132      }
1133      Node *base = get_map(elem);  // CheckCastPP node
1134      if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1135      tinst = igvn->type(base)->isa_oopptr();
1136    } else if (n->is_Phi() ||
1137               n->is_CheckCastPP() ||
1138               n->is_EncodeP() ||
1139               n->is_DecodeN() ||
1140               (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1141      if (visited.test_set(n->_idx)) {
1142        assert(n->is_Phi(), "loops only through Phi's");
1143        continue;  // already processed
1144      }
1145      ptset.Clear();
1146      PointsTo(ptset, n, igvn);
1147      if (ptset.Size() == 1) {
1148        uint elem = ptset.getelem(); // Allocation node's index
1149        if (elem == _phantom_object) {
1150          assert(false, "escaped allocation");
1151          continue; // Assume the value was set outside this method.
1152        }
1153        Node *val = get_map(elem);   // CheckCastPP node
1154        TypeNode *tn = n->as_Type();
1155        tinst = igvn->type(val)->isa_oopptr();
1156        assert(tinst != NULL && tinst->is_known_instance() &&
1157               (uint)tinst->instance_id() == elem , "instance type expected.");
1158
1159        const Type *tn_type = igvn->type(tn);
1160        const TypeOopPtr *tn_t;
1161        if (tn_type->isa_narrowoop()) {
1162          tn_t = tn_type->make_ptr()->isa_oopptr();
1163        } else {
1164          tn_t = tn_type->isa_oopptr();
1165        }
1166
1167        if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1168          if (tn_type->isa_narrowoop()) {
1169            tn_type = tinst->make_narrowoop();
1170          } else {
1171            tn_type = tinst;
1172          }
1173          igvn->hash_delete(tn);
1174          igvn->set_type(tn, tn_type);
1175          tn->set_type(tn_type);
1176          igvn->hash_insert(tn);
1177          record_for_optimizer(n);
1178        } else {
1179          assert(tn_type == TypePtr::NULL_PTR ||
1180                 tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
1181                 "unexpected type");
1182          continue; // Skip dead path with different type
1183        }
1184      }
1185    } else {
1186      debug_only(n->dump();)
1187      assert(false, "EA: unexpected node");
1188      continue;
1189    }
1190    // push allocation's users on appropriate worklist
1191    for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1192      Node *use = n->fast_out(i);
1193      if(use->is_Mem() && use->in(MemNode::Address) == n) {
1194        // Load/store to instance's field
1195        memnode_worklist.append_if_missing(use);
1196      } else if (use->is_MemBar()) {
1197        memnode_worklist.append_if_missing(use);
1198      } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1199        Node* addp2 = find_second_addp(use, n);
1200        if (addp2 != NULL) {
1201          alloc_worklist.append_if_missing(addp2);
1202        }
1203        alloc_worklist.append_if_missing(use);
1204      } else if (use->is_Phi() ||
1205                 use->is_CheckCastPP() ||
1206                 use->is_EncodeP() ||
1207                 use->is_DecodeN() ||
1208                 (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1209        alloc_worklist.append_if_missing(use);
1210#ifdef ASSERT
1211      } else if (use->is_Mem()) {
1212        assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
1213      } else if (use->is_MergeMem()) {
1214        assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1215      } else if (use->is_SafePoint()) {
1216        // Look for MergeMem nodes for calls which reference unique allocation
1217        // (through CheckCastPP nodes) even for debug info.
1218        Node* m = use->in(TypeFunc::Memory);
1219        if (m->is_MergeMem()) {
1220          assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1221        }
1222      } else {
1223        uint op = use->Opcode();
1224        if (!(op == Op_CmpP || op == Op_Conv2B ||
1225              op == Op_CastP2X || op == Op_StoreCM ||
1226              op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1227              op == Op_StrEquals || op == Op_StrIndexOf)) {
1228          n->dump();
1229          use->dump();
1230          assert(false, "EA: missing allocation reference path");
1231        }
1232#endif
1233      }
1234    }
1235
1236  }
1237  // New alias types were created in split_AddP().
1238  uint new_index_end = (uint) _compile->num_alias_types();
1239
1240  //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
1241  //            compute new values for Memory inputs  (the Memory inputs are not
1242  //            actually updated until phase 4.)
1243  if (memnode_worklist.length() == 0)
1244    return;  // nothing to do
1245
1246  while (memnode_worklist.length() != 0) {
1247    Node *n = memnode_worklist.pop();
1248    if (visited.test_set(n->_idx))
1249      continue;
1250    if (n->is_Phi() || n->is_ClearArray()) {
1251      // we don't need to do anything, but the users must be pushed
1252    } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1253      // we don't need to do anything, but the users must be pushed
1254      n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1255      if (n == NULL)
1256        continue;
1257    } else {
1258      assert(n->is_Mem(), "memory node required.");
1259      Node *addr = n->in(MemNode::Address);
1260      const Type *addr_t = igvn->type(addr);
1261      if (addr_t == Type::TOP)
1262        continue;
1263      assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1264      int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1265      assert ((uint)alias_idx < new_index_end, "wrong alias index");
1266      Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1267      if (_compile->failing()) {
1268        return;
1269      }
1270      if (mem != n->in(MemNode::Memory)) {
1271        // We delay the memory edge update since we need old one in
1272        // MergeMem code below when instances memory slices are separated.
1273        debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1274        assert(pn == NULL || pn == n, "wrong node");
1275        set_map(n->_idx, mem);
1276        ptnode_adr(n->_idx)->_node = n;
1277      }
1278      if (n->is_Load()) {
1279        continue;  // don't push users
1280      } else if (n->is_LoadStore()) {
1281        // get the memory projection
1282        for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1283          Node *use = n->fast_out(i);
1284          if (use->Opcode() == Op_SCMemProj) {
1285            n = use;
1286            break;
1287          }
1288        }
1289        assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1290      }
1291    }
1292    // push user on appropriate worklist
1293    for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1294      Node *use = n->fast_out(i);
1295      if (use->is_Phi() || use->is_ClearArray()) {
1296        memnode_worklist.append_if_missing(use);
1297      } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1298        if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
1299          continue;
1300        memnode_worklist.append_if_missing(use);
1301      } else if (use->is_MemBar()) {
1302        memnode_worklist.append_if_missing(use);
1303#ifdef ASSERT
1304      } else if(use->is_Mem()) {
1305        assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
1306      } else if (use->is_MergeMem()) {
1307        assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1308      } else {
1309        uint op = use->Opcode();
1310        if (!(op == Op_StoreCM ||
1311              (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
1312               strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
1313              op == Op_AryEq || op == Op_StrComp ||
1314              op == Op_StrEquals || op == Op_StrIndexOf)) {
1315          n->dump();
1316          use->dump();
1317          assert(false, "EA: missing memory path");
1318        }
1319#endif
1320      }
1321    }
1322  }
1323
1324  //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
1325  //            Walk each memory slice moving the first node encountered of each
1326  //            instance type to the the input corresponding to its alias index.
1327  uint length = _mergemem_worklist.length();
1328  for( uint next = 0; next < length; ++next ) {
1329    MergeMemNode* nmm = _mergemem_worklist.at(next);
1330    assert(!visited.test_set(nmm->_idx), "should not be visited before");
1331    // Note: we don't want to use MergeMemStream here because we only want to
1332    // scan inputs which exist at the start, not ones we add during processing.
1333    // Note 2: MergeMem may already contains instance memory slices added
1334    // during find_inst_mem() call when memory nodes were processed above.
1335    igvn->hash_delete(nmm);
1336    uint nslices = nmm->req();
1337    for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1338      Node* mem = nmm->in(i);
1339      Node* cur = NULL;
1340      if (mem == NULL || mem->is_top())
1341        continue;
1342      // First, update mergemem by moving memory nodes to corresponding slices
1343      // if their type became more precise since this mergemem was created.
1344      while (mem->is_Mem()) {
1345        const Type *at = igvn->type(mem->in(MemNode::Address));
1346        if (at != Type::TOP) {
1347          assert (at->isa_ptr() != NULL, "pointer type required.");
1348          uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1349          if (idx == i) {
1350            if (cur == NULL)
1351              cur = mem;
1352          } else {
1353            if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1354              nmm->set_memory_at(idx, mem);
1355            }
1356          }
1357        }
1358        mem = mem->in(MemNode::Memory);
1359      }
1360      nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1361      // Find any instance of the current type if we haven't encountered
1362      // already a memory slice of the instance along the memory chain.
1363      for (uint ni = new_index_start; ni < new_index_end; ni++) {
1364        if((uint)_compile->get_general_index(ni) == i) {
1365          Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1366          if (nmm->is_empty_memory(m)) {
1367            Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1368            if (_compile->failing()) {
1369              return;
1370            }
1371            nmm->set_memory_at(ni, result);
1372          }
1373        }
1374      }
1375    }
1376    // Find the rest of instances values
1377    for (uint ni = new_index_start; ni < new_index_end; ni++) {
1378      const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
1379      Node* result = step_through_mergemem(nmm, ni, tinst);
1380      if (result == nmm->base_memory()) {
1381        // Didn't find instance memory, search through general slice recursively.
1382        result = nmm->memory_at(_compile->get_general_index(ni));
1383        result = find_inst_mem(result, ni, orig_phis, igvn);
1384        if (_compile->failing()) {
1385          return;
1386        }
1387        nmm->set_memory_at(ni, result);
1388      }
1389    }
1390    igvn->hash_insert(nmm);
1391    record_for_optimizer(nmm);
1392  }
1393
1394  //  Phase 4:  Update the inputs of non-instance memory Phis and
1395  //            the Memory input of memnodes
1396  // First update the inputs of any non-instance Phi's from
1397  // which we split out an instance Phi.  Note we don't have
1398  // to recursively process Phi's encounted on the input memory
1399  // chains as is done in split_memory_phi() since they  will
1400  // also be processed here.
1401  for (int j = 0; j < orig_phis.length(); j++) {
1402    PhiNode *phi = orig_phis.at(j);
1403    int alias_idx = _compile->get_alias_index(phi->adr_type());
1404    igvn->hash_delete(phi);
1405    for (uint i = 1; i < phi->req(); i++) {
1406      Node *mem = phi->in(i);
1407      Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1408      if (_compile->failing()) {
1409        return;
1410      }
1411      if (mem != new_mem) {
1412        phi->set_req(i, new_mem);
1413      }
1414    }
1415    igvn->hash_insert(phi);
1416    record_for_optimizer(phi);
1417  }
1418
1419  // Update the memory inputs of MemNodes with the value we computed
1420  // in Phase 2 and move stores memory users to corresponding memory slices.
1421#ifdef ASSERT
1422  visited.Clear();
1423  Node_Stack old_mems(arena, _compile->unique() >> 2);
1424#endif
1425  for (uint i = 0; i < nodes_size(); i++) {
1426    Node *nmem = get_map(i);
1427    if (nmem != NULL) {
1428      Node *n = ptnode_adr(i)->_node;
1429      assert(n != NULL, "sanity");
1430      if (n->is_Mem()) {
1431#ifdef ASSERT
1432        Node* old_mem = n->in(MemNode::Memory);
1433        if (!visited.test_set(old_mem->_idx)) {
1434          old_mems.push(old_mem, old_mem->outcnt());
1435        }
1436#endif
1437        assert(n->in(MemNode::Memory) != nmem, "sanity");
1438        if (!n->is_Load()) {
1439          // Move memory users of a store first.
1440          move_inst_mem(n, orig_phis, igvn);
1441        }
1442        // Now update memory input
1443        igvn->hash_delete(n);
1444        n->set_req(MemNode::Memory, nmem);
1445        igvn->hash_insert(n);
1446        record_for_optimizer(n);
1447      } else {
1448        assert(n->is_Allocate() || n->is_CheckCastPP() ||
1449               n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1450      }
1451    }
1452  }
1453#ifdef ASSERT
1454  // Verify that memory was split correctly
1455  while (old_mems.is_nonempty()) {
1456    Node* old_mem = old_mems.node();
1457    uint  old_cnt = old_mems.index();
1458    old_mems.pop();
1459    assert(old_cnt = old_mem->outcnt(), "old mem could be lost");
1460  }
1461#endif
1462}
1463
1464bool ConnectionGraph::has_candidates(Compile *C) {
1465  // EA brings benefits only when the code has allocations and/or locks which
1466  // are represented by ideal Macro nodes.
1467  int cnt = C->macro_count();
1468  for( int i=0; i < cnt; i++ ) {
1469    Node *n = C->macro_node(i);
1470    if ( n->is_Allocate() )
1471      return true;
1472    if( n->is_Lock() ) {
1473      Node* obj = n->as_Lock()->obj_node()->uncast();
1474      if( !(obj->is_Parm() || obj->is_Con()) )
1475        return true;
1476    }
1477  }
1478  return false;
1479}
1480
1481bool ConnectionGraph::compute_escape() {
1482  Compile* C = _compile;
1483
1484  // 1. Populate Connection Graph (CG) with Ideal nodes.
1485
1486  Unique_Node_List worklist_init;
1487  worklist_init.map(C->unique(), NULL);  // preallocate space
1488
1489  // Initialize worklist
1490  if (C->root() != NULL) {
1491    worklist_init.push(C->root());
1492  }
1493
1494  GrowableArray<int> cg_worklist;
1495  PhaseGVN* igvn = C->initial_gvn();
1496  bool has_allocations = false;
1497
1498  // Push all useful nodes onto CG list and set their type.
1499  for( uint next = 0; next < worklist_init.size(); ++next ) {
1500    Node* n = worklist_init.at(next);
1501    record_for_escape_analysis(n, igvn);
1502    // Only allocations and java static calls results are checked
1503    // for an escape status. See process_call_result() below.
1504    if (n->is_Allocate() || n->is_CallStaticJava() &&
1505        ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1506      has_allocations = true;
1507    }
1508    if(n->is_AddP()) {
1509      // Collect address nodes which directly reference an allocation.
1510      // Use them during stage 3 below to build initial connection graph
1511      // field edges. Other field edges could be added after StoreP/LoadP
1512      // nodes are processed during stage 4 below.
1513      Node* base = get_addp_base(n);
1514      if(base->is_Proj() && base->in(0)->is_Allocate()) {
1515        cg_worklist.append(n->_idx);
1516      }
1517    } else if (n->is_MergeMem()) {
1518      // Collect all MergeMem nodes to add memory slices for
1519      // scalar replaceable objects in split_unique_types().
1520      _mergemem_worklist.append(n->as_MergeMem());
1521    }
1522    for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1523      Node* m = n->fast_out(i);   // Get user
1524      worklist_init.push(m);
1525    }
1526  }
1527
1528  if (!has_allocations) {
1529    _collecting = false;
1530    return false; // Nothing to do.
1531  }
1532
1533  // 2. First pass to create simple CG edges (doesn't require to walk CG).
1534  uint delayed_size = _delayed_worklist.size();
1535  for( uint next = 0; next < delayed_size; ++next ) {
1536    Node* n = _delayed_worklist.at(next);
1537    build_connection_graph(n, igvn);
1538  }
1539
1540  // 3. Pass to create fields edges (Allocate -F-> AddP).
1541  uint cg_length = cg_worklist.length();
1542  for( uint next = 0; next < cg_length; ++next ) {
1543    int ni = cg_worklist.at(next);
1544    build_connection_graph(ptnode_adr(ni)->_node, igvn);
1545  }
1546
1547  cg_worklist.clear();
1548  cg_worklist.append(_phantom_object);
1549
1550  // 4. Build Connection Graph which need
1551  //    to walk the connection graph.
1552  for (uint ni = 0; ni < nodes_size(); ni++) {
1553    PointsToNode* ptn = ptnode_adr(ni);
1554    Node *n = ptn->_node;
1555    if (n != NULL) { // Call, AddP, LoadP, StoreP
1556      build_connection_graph(n, igvn);
1557      if (ptn->node_type() != PointsToNode::UnknownType)
1558        cg_worklist.append(n->_idx); // Collect CG nodes
1559    }
1560  }
1561
1562  Arena* arena = Thread::current()->resource_area();
1563  VectorSet ptset(arena);
1564  GrowableArray<uint>  deferred_edges;
1565  VectorSet visited(arena);
1566
1567  // 5. Remove deferred edges from the graph and adjust
1568  //    escape state of nonescaping objects.
1569  cg_length = cg_worklist.length();
1570  for( uint next = 0; next < cg_length; ++next ) {
1571    int ni = cg_worklist.at(next);
1572    PointsToNode* ptn = ptnode_adr(ni);
1573    PointsToNode::NodeType nt = ptn->node_type();
1574    if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1575      remove_deferred(ni, &deferred_edges, &visited);
1576      Node *n = ptn->_node;
1577      if (n->is_AddP()) {
1578        // Search for objects which are not scalar replaceable
1579        // and adjust their escape state.
1580        verify_escape_state(ni, ptset, igvn);
1581      }
1582    }
1583  }
1584
1585  // 6. Propagate escape states.
1586  GrowableArray<int>  worklist;
1587  bool has_non_escaping_obj = false;
1588
1589  // push all GlobalEscape nodes on the worklist
1590  for( uint next = 0; next < cg_length; ++next ) {
1591    int nk = cg_worklist.at(next);
1592    if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
1593      worklist.push(nk);
1594  }
1595  // mark all nodes reachable from GlobalEscape nodes
1596  while(worklist.length() > 0) {
1597    PointsToNode* ptn = ptnode_adr(worklist.pop());
1598    uint e_cnt = ptn->edge_count();
1599    for (uint ei = 0; ei < e_cnt; ei++) {
1600      uint npi = ptn->edge_target(ei);
1601      PointsToNode *np = ptnode_adr(npi);
1602      if (np->escape_state() < PointsToNode::GlobalEscape) {
1603        np->set_escape_state(PointsToNode::GlobalEscape);
1604        worklist.push(npi);
1605      }
1606    }
1607  }
1608
1609  // push all ArgEscape nodes on the worklist
1610  for( uint next = 0; next < cg_length; ++next ) {
1611    int nk = cg_worklist.at(next);
1612    if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
1613      worklist.push(nk);
1614  }
1615  // mark all nodes reachable from ArgEscape nodes
1616  while(worklist.length() > 0) {
1617    PointsToNode* ptn = ptnode_adr(worklist.pop());
1618    if (ptn->node_type() == PointsToNode::JavaObject)
1619      has_non_escaping_obj = true; // Non GlobalEscape
1620    uint e_cnt = ptn->edge_count();
1621    for (uint ei = 0; ei < e_cnt; ei++) {
1622      uint npi = ptn->edge_target(ei);
1623      PointsToNode *np = ptnode_adr(npi);
1624      if (np->escape_state() < PointsToNode::ArgEscape) {
1625        np->set_escape_state(PointsToNode::ArgEscape);
1626        worklist.push(npi);
1627      }
1628    }
1629  }
1630
1631  GrowableArray<Node*> alloc_worklist;
1632
1633  // push all NoEscape nodes on the worklist
1634  for( uint next = 0; next < cg_length; ++next ) {
1635    int nk = cg_worklist.at(next);
1636    if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1637      worklist.push(nk);
1638  }
1639  // mark all nodes reachable from NoEscape nodes
1640  while(worklist.length() > 0) {
1641    PointsToNode* ptn = ptnode_adr(worklist.pop());
1642    if (ptn->node_type() == PointsToNode::JavaObject)
1643      has_non_escaping_obj = true; // Non GlobalEscape
1644    Node* n = ptn->_node;
1645    if (n->is_Allocate() && ptn->_scalar_replaceable ) {
1646      // Push scalar replaceable allocations on alloc_worklist
1647      // for processing in split_unique_types().
1648      alloc_worklist.append(n);
1649    }
1650    uint e_cnt = ptn->edge_count();
1651    for (uint ei = 0; ei < e_cnt; ei++) {
1652      uint npi = ptn->edge_target(ei);
1653      PointsToNode *np = ptnode_adr(npi);
1654      if (np->escape_state() < PointsToNode::NoEscape) {
1655        np->set_escape_state(PointsToNode::NoEscape);
1656        worklist.push(npi);
1657      }
1658    }
1659  }
1660
1661  _collecting = false;
1662  assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1663
1664  bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1665  if ( has_scalar_replaceable_candidates &&
1666       C->AliasLevel() >= 3 && EliminateAllocations ) {
1667
1668    // Now use the escape information to create unique types for
1669    // scalar replaceable objects.
1670    split_unique_types(alloc_worklist);
1671
1672    if (C->failing())  return false;
1673
1674    // Clean up after split unique types.
1675    ResourceMark rm;
1676    PhaseRemoveUseless pru(C->initial_gvn(), C->for_igvn());
1677
1678    C->print_method("After Escape Analysis", 2);
1679
1680#ifdef ASSERT
1681  } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1682    tty->print("=== No allocations eliminated for ");
1683    C->method()->print_short_name();
1684    if(!EliminateAllocations) {
1685      tty->print(" since EliminateAllocations is off ===");
1686    } else if(!has_scalar_replaceable_candidates) {
1687      tty->print(" since there are no scalar replaceable candidates ===");
1688    } else if(C->AliasLevel() < 3) {
1689      tty->print(" since AliasLevel < 3 ===");
1690    }
1691    tty->cr();
1692#endif
1693  }
1694  return has_non_escaping_obj;
1695}
1696
1697// Search for objects which are not scalar replaceable.
1698void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
1699  PointsToNode* ptn = ptnode_adr(nidx);
1700  Node* n = ptn->_node;
1701  assert(n->is_AddP(), "Should be called for AddP nodes only");
1702  // Search for objects which are not scalar replaceable.
1703  // Mark their escape state as ArgEscape to propagate the state
1704  // to referenced objects.
1705  // Note: currently there are no difference in compiler optimizations
1706  // for ArgEscape objects and NoEscape objects which are not
1707  // scalar replaceable.
1708
1709  Compile* C = _compile;
1710
1711  int offset = ptn->offset();
1712  Node* base = get_addp_base(n);
1713  ptset.Clear();
1714  PointsTo(ptset, base, phase);
1715  int ptset_size = ptset.Size();
1716
1717  // Check if a oop field's initializing value is recorded and add
1718  // a corresponding NULL field's value if it is not recorded.
1719  // Connection Graph does not record a default initialization by NULL
1720  // captured by Initialize node.
1721  //
1722  // Note: it will disable scalar replacement in some cases:
1723  //
1724  //    Point p[] = new Point[1];
1725  //    p[0] = new Point(); // Will be not scalar replaced
1726  //
1727  // but it will save us from incorrect optimizations in next cases:
1728  //
1729  //    Point p[] = new Point[1];
1730  //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1731  //
1732  // Do a simple control flow analysis to distinguish above cases.
1733  //
1734  if (offset != Type::OffsetBot && ptset_size == 1) {
1735    uint elem = ptset.getelem(); // Allocation node's index
1736    // It does not matter if it is not Allocation node since
1737    // only non-escaping allocations are scalar replaced.
1738    if (ptnode_adr(elem)->_node->is_Allocate() &&
1739        ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
1740      AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
1741      InitializeNode* ini = alloc->initialization();
1742
1743      // Check only oop fields.
1744      const Type* adr_type = n->as_AddP()->bottom_type();
1745      BasicType basic_field_type = T_INT;
1746      if (adr_type->isa_instptr()) {
1747        ciField* field = C->alias_type(adr_type->isa_instptr())->field();
1748        if (field != NULL) {
1749          basic_field_type = field->layout_type();
1750        } else {
1751          // Ignore non field load (for example, klass load)
1752        }
1753      } else if (adr_type->isa_aryptr()) {
1754        const Type* elemtype = adr_type->isa_aryptr()->elem();
1755        basic_field_type = elemtype->array_element_basic_type();
1756      } else {
1757        // Raw pointers are used for initializing stores so skip it.
1758        assert(adr_type->isa_rawptr() && base->is_Proj() &&
1759               (base->in(0) == alloc),"unexpected pointer type");
1760      }
1761      if (basic_field_type == T_OBJECT ||
1762          basic_field_type == T_NARROWOOP ||
1763          basic_field_type == T_ARRAY) {
1764        Node* value = NULL;
1765        if (ini != NULL) {
1766          BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1767          Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1768          if (store != NULL && store->is_Store()) {
1769            value = store->in(MemNode::ValueIn);
1770          } else if (ptn->edge_count() > 0) { // Are there oop stores?
1771            // Check for a store which follows allocation without branches.
1772            // For example, a volatile field store is not collected
1773            // by Initialize node. TODO: it would be nice to use idom() here.
1774            for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1775              store = n->fast_out(i);
1776              if (store->is_Store() && store->in(0) != NULL) {
1777                Node* ctrl = store->in(0);
1778                while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
1779                        ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
1780                        ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
1781                   ctrl = ctrl->in(0);
1782                }
1783                if (ctrl == ini || ctrl == alloc) {
1784                  value = store->in(MemNode::ValueIn);
1785                  break;
1786                }
1787              }
1788            }
1789          }
1790        }
1791        if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1792          // A field's initializing value was not recorded. Add NULL.
1793          uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1794          add_pointsto_edge(nidx, null_idx);
1795        }
1796      }
1797    }
1798  }
1799
1800  // An object is not scalar replaceable if the field which may point
1801  // to it has unknown offset (unknown element of an array of objects).
1802  //
1803  if (offset == Type::OffsetBot) {
1804    uint e_cnt = ptn->edge_count();
1805    for (uint ei = 0; ei < e_cnt; ei++) {
1806      uint npi = ptn->edge_target(ei);
1807      set_escape_state(npi, PointsToNode::ArgEscape);
1808      ptnode_adr(npi)->_scalar_replaceable = false;
1809    }
1810  }
1811
1812  // Currently an object is not scalar replaceable if a LoadStore node
1813  // access its field since the field value is unknown after it.
1814  //
1815  bool has_LoadStore = false;
1816  for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1817    Node *use = n->fast_out(i);
1818    if (use->is_LoadStore()) {
1819      has_LoadStore = true;
1820      break;
1821    }
1822  }
1823  // An object is not scalar replaceable if the address points
1824  // to unknown field (unknown element for arrays, offset is OffsetBot).
1825  //
1826  // Or the address may point to more then one object. This may produce
1827  // the false positive result (set scalar_replaceable to false)
1828  // since the flow-insensitive escape analysis can't separate
1829  // the case when stores overwrite the field's value from the case
1830  // when stores happened on different control branches.
1831  //
1832  if (ptset_size > 1 || ptset_size != 0 &&
1833      (has_LoadStore || offset == Type::OffsetBot)) {
1834    for( VectorSetI j(&ptset); j.test(); ++j ) {
1835      set_escape_state(j.elem, PointsToNode::ArgEscape);
1836      ptnode_adr(j.elem)->_scalar_replaceable = false;
1837    }
1838  }
1839}
1840
1841void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1842
1843    switch (call->Opcode()) {
1844#ifdef ASSERT
1845    case Op_Allocate:
1846    case Op_AllocateArray:
1847    case Op_Lock:
1848    case Op_Unlock:
1849      assert(false, "should be done already");
1850      break;
1851#endif
1852    case Op_CallLeaf:
1853    case Op_CallLeafNoFP:
1854    {
1855      // Stub calls, objects do not escape but they are not scale replaceable.
1856      // Adjust escape state for outgoing arguments.
1857      const TypeTuple * d = call->tf()->domain();
1858      VectorSet ptset(Thread::current()->resource_area());
1859      for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1860        const Type* at = d->field_at(i);
1861        Node *arg = call->in(i)->uncast();
1862        const Type *aat = phase->type(arg);
1863        if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
1864            ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
1865
1866          assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1867                 aat->isa_ptr() != NULL, "expecting an Ptr");
1868#ifdef ASSERT
1869          if (!(call->Opcode() == Op_CallLeafNoFP &&
1870                call->as_CallLeaf()->_name != NULL &&
1871                (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
1872                call->as_CallLeaf()->_name != NULL &&
1873                (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
1874                 strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
1875          ) {
1876            call->dump();
1877            assert(false, "EA: unexpected CallLeaf");
1878          }
1879#endif
1880          set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1881          if (arg->is_AddP()) {
1882            //
1883            // The inline_native_clone() case when the arraycopy stub is called
1884            // after the allocation before Initialize and CheckCastPP nodes.
1885            //
1886            // Set AddP's base (Allocate) as not scalar replaceable since
1887            // pointer to the base (with offset) is passed as argument.
1888            //
1889            arg = get_addp_base(arg);
1890          }
1891          ptset.Clear();
1892          PointsTo(ptset, arg, phase);
1893          for( VectorSetI j(&ptset); j.test(); ++j ) {
1894            uint pt = j.elem;
1895            set_escape_state(pt, PointsToNode::ArgEscape);
1896          }
1897        }
1898      }
1899      break;
1900    }
1901
1902    case Op_CallStaticJava:
1903    // For a static call, we know exactly what method is being called.
1904    // Use bytecode estimator to record the call's escape affects
1905    {
1906      ciMethod *meth = call->as_CallJava()->method();
1907      BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1908      // fall-through if not a Java method or no analyzer information
1909      if (call_analyzer != NULL) {
1910        const TypeTuple * d = call->tf()->domain();
1911        VectorSet ptset(Thread::current()->resource_area());
1912        bool copy_dependencies = false;
1913        for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1914          const Type* at = d->field_at(i);
1915          int k = i - TypeFunc::Parms;
1916          Node *arg = call->in(i)->uncast();
1917
1918          if (at->isa_oopptr() != NULL &&
1919              ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
1920
1921            bool global_escapes = false;
1922            bool fields_escapes = false;
1923            if (!call_analyzer->is_arg_stack(k)) {
1924              // The argument global escapes, mark everything it could point to
1925              set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1926              global_escapes = true;
1927            } else {
1928              if (!call_analyzer->is_arg_local(k)) {
1929                // The argument itself doesn't escape, but any fields might
1930                fields_escapes = true;
1931              }
1932              set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1933              copy_dependencies = true;
1934            }
1935
1936            ptset.Clear();
1937            PointsTo(ptset, arg, phase);
1938            for( VectorSetI j(&ptset); j.test(); ++j ) {
1939              uint pt = j.elem;
1940              if (global_escapes) {
1941                //The argument global escapes, mark everything it could point to
1942                set_escape_state(pt, PointsToNode::GlobalEscape);
1943              } else {
1944                if (fields_escapes) {
1945                  // The argument itself doesn't escape, but any fields might
1946                  add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
1947                }
1948                set_escape_state(pt, PointsToNode::ArgEscape);
1949              }
1950            }
1951          }
1952        }
1953        if (copy_dependencies)
1954          call_analyzer->copy_dependencies(_compile->dependencies());
1955        break;
1956      }
1957    }
1958
1959    default:
1960    // Fall-through here if not a Java method or no analyzer information
1961    // or some other type of call, assume the worst case: all arguments
1962    // globally escape.
1963    {
1964      // adjust escape state for  outgoing arguments
1965      const TypeTuple * d = call->tf()->domain();
1966      VectorSet ptset(Thread::current()->resource_area());
1967      for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1968        const Type* at = d->field_at(i);
1969        if (at->isa_oopptr() != NULL) {
1970          Node *arg = call->in(i)->uncast();
1971          set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1972          ptset.Clear();
1973          PointsTo(ptset, arg, phase);
1974          for( VectorSetI j(&ptset); j.test(); ++j ) {
1975            uint pt = j.elem;
1976            set_escape_state(pt, PointsToNode::GlobalEscape);
1977          }
1978        }
1979      }
1980    }
1981  }
1982}
1983void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
1984  CallNode   *call = resproj->in(0)->as_Call();
1985  uint    call_idx = call->_idx;
1986  uint resproj_idx = resproj->_idx;
1987
1988  switch (call->Opcode()) {
1989    case Op_Allocate:
1990    {
1991      Node *k = call->in(AllocateNode::KlassNode);
1992      const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
1993      assert(kt != NULL, "TypeKlassPtr  required.");
1994      ciKlass* cik = kt->klass();
1995
1996      PointsToNode::EscapeState es;
1997      uint edge_to;
1998      if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
1999         !cik->is_instance_klass() || // StressReflectiveCode
2000          cik->as_instance_klass()->has_finalizer()) {
2001        es = PointsToNode::GlobalEscape;
2002        edge_to = _phantom_object; // Could not be worse
2003      } else {
2004        es = PointsToNode::NoEscape;
2005        edge_to = call_idx;
2006      }
2007      set_escape_state(call_idx, es);
2008      add_pointsto_edge(resproj_idx, edge_to);
2009      _processed.set(resproj_idx);
2010      break;
2011    }
2012
2013    case Op_AllocateArray:
2014    {
2015
2016      Node *k = call->in(AllocateNode::KlassNode);
2017      const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2018      assert(kt != NULL, "TypeKlassPtr  required.");
2019      ciKlass* cik = kt->klass();
2020
2021      PointsToNode::EscapeState es;
2022      uint edge_to;
2023      if (!cik->is_array_klass()) { // StressReflectiveCode
2024        es = PointsToNode::GlobalEscape;
2025        edge_to = _phantom_object;
2026      } else {
2027        es = PointsToNode::NoEscape;
2028        edge_to = call_idx;
2029        int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2030        if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2031          // Not scalar replaceable if the length is not constant or too big.
2032          ptnode_adr(call_idx)->_scalar_replaceable = false;
2033        }
2034      }
2035      set_escape_state(call_idx, es);
2036      add_pointsto_edge(resproj_idx, edge_to);
2037      _processed.set(resproj_idx);
2038      break;
2039    }
2040
2041    case Op_CallStaticJava:
2042    // For a static call, we know exactly what method is being called.
2043    // Use bytecode estimator to record whether the call's return value escapes
2044    {
2045      bool done = true;
2046      const TypeTuple *r = call->tf()->range();
2047      const Type* ret_type = NULL;
2048
2049      if (r->cnt() > TypeFunc::Parms)
2050        ret_type = r->field_at(TypeFunc::Parms);
2051
2052      // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
2053      //        _multianewarray functions return a TypeRawPtr.
2054      if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2055        _processed.set(resproj_idx);
2056        break;  // doesn't return a pointer type
2057      }
2058      ciMethod *meth = call->as_CallJava()->method();
2059      const TypeTuple * d = call->tf()->domain();
2060      if (meth == NULL) {
2061        // not a Java method, assume global escape
2062        set_escape_state(call_idx, PointsToNode::GlobalEscape);
2063        add_pointsto_edge(resproj_idx, _phantom_object);
2064      } else {
2065        BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2066        bool copy_dependencies = false;
2067
2068        if (call_analyzer->is_return_allocated()) {
2069          // Returns a newly allocated unescaped object, simply
2070          // update dependency information.
2071          // Mark it as NoEscape so that objects referenced by
2072          // it's fields will be marked as NoEscape at least.
2073          set_escape_state(call_idx, PointsToNode::NoEscape);
2074          add_pointsto_edge(resproj_idx, call_idx);
2075          copy_dependencies = true;
2076        } else if (call_analyzer->is_return_local()) {
2077          // determine whether any arguments are returned
2078          set_escape_state(call_idx, PointsToNode::NoEscape);
2079          bool ret_arg = false;
2080          for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2081            const Type* at = d->field_at(i);
2082
2083            if (at->isa_oopptr() != NULL) {
2084              Node *arg = call->in(i)->uncast();
2085
2086              if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2087                ret_arg = true;
2088                PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2089                if (arg_esp->node_type() == PointsToNode::UnknownType)
2090                  done = false;
2091                else if (arg_esp->node_type() == PointsToNode::JavaObject)
2092                  add_pointsto_edge(resproj_idx, arg->_idx);
2093                else
2094                  add_deferred_edge(resproj_idx, arg->_idx);
2095                arg_esp->_hidden_alias = true;
2096              }
2097            }
2098          }
2099          if (done && !ret_arg) {
2100            // Returns unknown object.
2101            set_escape_state(call_idx, PointsToNode::GlobalEscape);
2102            add_pointsto_edge(resproj_idx, _phantom_object);
2103          }
2104          copy_dependencies = true;
2105        } else {
2106          set_escape_state(call_idx, PointsToNode::GlobalEscape);
2107          add_pointsto_edge(resproj_idx, _phantom_object);
2108          for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2109            const Type* at = d->field_at(i);
2110            if (at->isa_oopptr() != NULL) {
2111              Node *arg = call->in(i)->uncast();
2112              PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2113              arg_esp->_hidden_alias = true;
2114            }
2115          }
2116        }
2117        if (copy_dependencies)
2118          call_analyzer->copy_dependencies(_compile->dependencies());
2119      }
2120      if (done)
2121        _processed.set(resproj_idx);
2122      break;
2123    }
2124
2125    default:
2126    // Some other type of call, assume the worst case that the
2127    // returned value, if any, globally escapes.
2128    {
2129      const TypeTuple *r = call->tf()->range();
2130      if (r->cnt() > TypeFunc::Parms) {
2131        const Type* ret_type = r->field_at(TypeFunc::Parms);
2132
2133        // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
2134        //        _multianewarray functions return a TypeRawPtr.
2135        if (ret_type->isa_ptr() != NULL) {
2136          set_escape_state(call_idx, PointsToNode::GlobalEscape);
2137          add_pointsto_edge(resproj_idx, _phantom_object);
2138        }
2139      }
2140      _processed.set(resproj_idx);
2141    }
2142  }
2143}
2144
2145// Populate Connection Graph with Ideal nodes and create simple
2146// connection graph edges (do not need to check the node_type of inputs
2147// or to call PointsTo() to walk the connection graph).
2148void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2149  if (_processed.test(n->_idx))
2150    return; // No need to redefine node's state.
2151
2152  if (n->is_Call()) {
2153    // Arguments to allocation and locking don't escape.
2154    if (n->is_Allocate()) {
2155      add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2156      record_for_optimizer(n);
2157    } else if (n->is_Lock() || n->is_Unlock()) {
2158      // Put Lock and Unlock nodes on IGVN worklist to process them during
2159      // the first IGVN optimization when escape information is still available.
2160      record_for_optimizer(n);
2161      _processed.set(n->_idx);
2162    } else {
2163      // Don't mark as processed since call's arguments have to be processed.
2164      PointsToNode::NodeType nt = PointsToNode::UnknownType;
2165      PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2166
2167      // Check if a call returns an object.
2168      const TypeTuple *r = n->as_Call()->tf()->range();
2169      if (r->cnt() > TypeFunc::Parms &&
2170          r->field_at(TypeFunc::Parms)->isa_ptr() &&
2171          n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2172        nt = PointsToNode::JavaObject;
2173        if (!n->is_CallStaticJava()) {
2174          // Since the called mathod is statically unknown assume
2175          // the worst case that the returned value globally escapes.
2176          es = PointsToNode::GlobalEscape;
2177        }
2178      }
2179      add_node(n, nt, es, false);
2180    }
2181    return;
2182  }
2183
2184  // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2185  // ThreadLocal has RawPrt type.
2186  switch (n->Opcode()) {
2187    case Op_AddP:
2188    {
2189      add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
2190      break;
2191    }
2192    case Op_CastX2P:
2193    { // "Unsafe" memory access.
2194      add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2195      break;
2196    }
2197    case Op_CastPP:
2198    case Op_CheckCastPP:
2199    case Op_EncodeP:
2200    case Op_DecodeN:
2201    {
2202      add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2203      int ti = n->in(1)->_idx;
2204      PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2205      if (nt == PointsToNode::UnknownType) {
2206        _delayed_worklist.push(n); // Process it later.
2207        break;
2208      } else if (nt == PointsToNode::JavaObject) {
2209        add_pointsto_edge(n->_idx, ti);
2210      } else {
2211        add_deferred_edge(n->_idx, ti);
2212      }
2213      _processed.set(n->_idx);
2214      break;
2215    }
2216    case Op_ConP:
2217    {
2218      // assume all pointer constants globally escape except for null
2219      PointsToNode::EscapeState es;
2220      if (phase->type(n) == TypePtr::NULL_PTR)
2221        es = PointsToNode::NoEscape;
2222      else
2223        es = PointsToNode::GlobalEscape;
2224
2225      add_node(n, PointsToNode::JavaObject, es, true);
2226      break;
2227    }
2228    case Op_ConN:
2229    {
2230      // assume all narrow oop constants globally escape except for null
2231      PointsToNode::EscapeState es;
2232      if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2233        es = PointsToNode::NoEscape;
2234      else
2235        es = PointsToNode::GlobalEscape;
2236
2237      add_node(n, PointsToNode::JavaObject, es, true);
2238      break;
2239    }
2240    case Op_CreateEx:
2241    {
2242      // assume that all exception objects globally escape
2243      add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2244      break;
2245    }
2246    case Op_LoadKlass:
2247    case Op_LoadNKlass:
2248    {
2249      add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2250      break;
2251    }
2252    case Op_LoadP:
2253    case Op_LoadN:
2254    {
2255      const Type *t = phase->type(n);
2256      if (t->make_ptr() == NULL) {
2257        _processed.set(n->_idx);
2258        return;
2259      }
2260      add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2261      break;
2262    }
2263    case Op_Parm:
2264    {
2265      _processed.set(n->_idx); // No need to redefine it state.
2266      uint con = n->as_Proj()->_con;
2267      if (con < TypeFunc::Parms)
2268        return;
2269      const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2270      if (t->isa_ptr() == NULL)
2271        return;
2272      // We have to assume all input parameters globally escape
2273      // (Note: passing 'false' since _processed is already set).
2274      add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2275      break;
2276    }
2277    case Op_Phi:
2278    {
2279      const Type *t = n->as_Phi()->type();
2280      if (t->make_ptr() == NULL) {
2281        // nothing to do if not an oop or narrow oop
2282        _processed.set(n->_idx);
2283        return;
2284      }
2285      add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2286      uint i;
2287      for (i = 1; i < n->req() ; i++) {
2288        Node* in = n->in(i);
2289        if (in == NULL)
2290          continue;  // ignore NULL
2291        in = in->uncast();
2292        if (in->is_top() || in == n)
2293          continue;  // ignore top or inputs which go back this node
2294        int ti = in->_idx;
2295        PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2296        if (nt == PointsToNode::UnknownType) {
2297          break;
2298        } else if (nt == PointsToNode::JavaObject) {
2299          add_pointsto_edge(n->_idx, ti);
2300        } else {
2301          add_deferred_edge(n->_idx, ti);
2302        }
2303      }
2304      if (i >= n->req())
2305        _processed.set(n->_idx);
2306      else
2307        _delayed_worklist.push(n);
2308      break;
2309    }
2310    case Op_Proj:
2311    {
2312      // we are only interested in the oop result projection from a call
2313      if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2314        const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2315        assert(r->cnt() > TypeFunc::Parms, "sanity");
2316        if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2317          add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2318          int ti = n->in(0)->_idx;
2319          // The call may not be registered yet (since not all its inputs are registered)
2320          // if this is the projection from backbranch edge of Phi.
2321          if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2322            process_call_result(n->as_Proj(), phase);
2323          }
2324          if (!_processed.test(n->_idx)) {
2325            // The call's result may need to be processed later if the call
2326            // returns it's argument and the argument is not processed yet.
2327            _delayed_worklist.push(n);
2328          }
2329          break;
2330        }
2331      }
2332      _processed.set(n->_idx);
2333      break;
2334    }
2335    case Op_Return:
2336    {
2337      if( n->req() > TypeFunc::Parms &&
2338          phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2339        // Treat Return value as LocalVar with GlobalEscape escape state.
2340        add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2341        int ti = n->in(TypeFunc::Parms)->_idx;
2342        PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2343        if (nt == PointsToNode::UnknownType) {
2344          _delayed_worklist.push(n); // Process it later.
2345          break;
2346        } else if (nt == PointsToNode::JavaObject) {
2347          add_pointsto_edge(n->_idx, ti);
2348        } else {
2349          add_deferred_edge(n->_idx, ti);
2350        }
2351      }
2352      _processed.set(n->_idx);
2353      break;
2354    }
2355    case Op_StoreP:
2356    case Op_StoreN:
2357    {
2358      const Type *adr_type = phase->type(n->in(MemNode::Address));
2359      adr_type = adr_type->make_ptr();
2360      if (adr_type->isa_oopptr()) {
2361        add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2362      } else {
2363        Node* adr = n->in(MemNode::Address);
2364        if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2365            adr->in(AddPNode::Address)->is_Proj() &&
2366            adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2367          add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2368          // We are computing a raw address for a store captured
2369          // by an Initialize compute an appropriate address type.
2370          int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2371          assert(offs != Type::OffsetBot, "offset must be a constant");
2372        } else {
2373          _processed.set(n->_idx);
2374          return;
2375        }
2376      }
2377      break;
2378    }
2379    case Op_StorePConditional:
2380    case Op_CompareAndSwapP:
2381    case Op_CompareAndSwapN:
2382    {
2383      const Type *adr_type = phase->type(n->in(MemNode::Address));
2384      adr_type = adr_type->make_ptr();
2385      if (adr_type->isa_oopptr()) {
2386        add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2387      } else {
2388        _processed.set(n->_idx);
2389        return;
2390      }
2391      break;
2392    }
2393    case Op_AryEq:
2394    case Op_StrComp:
2395    case Op_StrEquals:
2396    case Op_StrIndexOf:
2397    {
2398      // char[] arrays passed to string intrinsics are not scalar replaceable.
2399      add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2400      break;
2401    }
2402    case Op_ThreadLocal:
2403    {
2404      add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2405      break;
2406    }
2407    default:
2408      ;
2409      // nothing to do
2410  }
2411  return;
2412}
2413
2414void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2415  uint n_idx = n->_idx;
2416  assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2417
2418  // Don't set processed bit for AddP, LoadP, StoreP since
2419  // they may need more then one pass to process.
2420  if (_processed.test(n_idx))
2421    return; // No need to redefine node's state.
2422
2423  if (n->is_Call()) {
2424    CallNode *call = n->as_Call();
2425    process_call_arguments(call, phase);
2426    _processed.set(n_idx);
2427    return;
2428  }
2429
2430  switch (n->Opcode()) {
2431    case Op_AddP:
2432    {
2433      Node *base = get_addp_base(n);
2434      // Create a field edge to this node from everything base could point to.
2435      VectorSet ptset(Thread::current()->resource_area());
2436      PointsTo(ptset, base, phase);
2437      for( VectorSetI i(&ptset); i.test(); ++i ) {
2438        uint pt = i.elem;
2439        add_field_edge(pt, n_idx, address_offset(n, phase));
2440      }
2441      break;
2442    }
2443    case Op_CastX2P:
2444    {
2445      assert(false, "Op_CastX2P");
2446      break;
2447    }
2448    case Op_CastPP:
2449    case Op_CheckCastPP:
2450    case Op_EncodeP:
2451    case Op_DecodeN:
2452    {
2453      int ti = n->in(1)->_idx;
2454      assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2455      if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2456        add_pointsto_edge(n_idx, ti);
2457      } else {
2458        add_deferred_edge(n_idx, ti);
2459      }
2460      _processed.set(n_idx);
2461      break;
2462    }
2463    case Op_ConP:
2464    {
2465      assert(false, "Op_ConP");
2466      break;
2467    }
2468    case Op_ConN:
2469    {
2470      assert(false, "Op_ConN");
2471      break;
2472    }
2473    case Op_CreateEx:
2474    {
2475      assert(false, "Op_CreateEx");
2476      break;
2477    }
2478    case Op_LoadKlass:
2479    case Op_LoadNKlass:
2480    {
2481      assert(false, "Op_LoadKlass");
2482      break;
2483    }
2484    case Op_LoadP:
2485    case Op_LoadN:
2486    {
2487      const Type *t = phase->type(n);
2488#ifdef ASSERT
2489      if (t->make_ptr() == NULL)
2490        assert(false, "Op_LoadP");
2491#endif
2492
2493      Node* adr = n->in(MemNode::Address)->uncast();
2494      Node* adr_base;
2495      if (adr->is_AddP()) {
2496        adr_base = get_addp_base(adr);
2497      } else {
2498        adr_base = adr;
2499      }
2500
2501      // For everything "adr_base" could point to, create a deferred edge from
2502      // this node to each field with the same offset.
2503      VectorSet ptset(Thread::current()->resource_area());
2504      PointsTo(ptset, adr_base, phase);
2505      int offset = address_offset(adr, phase);
2506      for( VectorSetI i(&ptset); i.test(); ++i ) {
2507        uint pt = i.elem;
2508        add_deferred_edge_to_fields(n_idx, pt, offset);
2509      }
2510      break;
2511    }
2512    case Op_Parm:
2513    {
2514      assert(false, "Op_Parm");
2515      break;
2516    }
2517    case Op_Phi:
2518    {
2519#ifdef ASSERT
2520      const Type *t = n->as_Phi()->type();
2521      if (t->make_ptr() == NULL)
2522        assert(false, "Op_Phi");
2523#endif
2524      for (uint i = 1; i < n->req() ; i++) {
2525        Node* in = n->in(i);
2526        if (in == NULL)
2527          continue;  // ignore NULL
2528        in = in->uncast();
2529        if (in->is_top() || in == n)
2530          continue;  // ignore top or inputs which go back this node
2531        int ti = in->_idx;
2532        PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2533        assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2534        if (nt == PointsToNode::JavaObject) {
2535          add_pointsto_edge(n_idx, ti);
2536        } else {
2537          add_deferred_edge(n_idx, ti);
2538        }
2539      }
2540      _processed.set(n_idx);
2541      break;
2542    }
2543    case Op_Proj:
2544    {
2545      // we are only interested in the oop result projection from a call
2546      if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2547        assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
2548               "all nodes should be registered");
2549        const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2550        assert(r->cnt() > TypeFunc::Parms, "sanity");
2551        if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2552          process_call_result(n->as_Proj(), phase);
2553          assert(_processed.test(n_idx), "all call results should be processed");
2554          break;
2555        }
2556      }
2557      assert(false, "Op_Proj");
2558      break;
2559    }
2560    case Op_Return:
2561    {
2562#ifdef ASSERT
2563      if( n->req() <= TypeFunc::Parms ||
2564          !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2565        assert(false, "Op_Return");
2566      }
2567#endif
2568      int ti = n->in(TypeFunc::Parms)->_idx;
2569      assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
2570      if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2571        add_pointsto_edge(n_idx, ti);
2572      } else {
2573        add_deferred_edge(n_idx, ti);
2574      }
2575      _processed.set(n_idx);
2576      break;
2577    }
2578    case Op_StoreP:
2579    case Op_StoreN:
2580    case Op_StorePConditional:
2581    case Op_CompareAndSwapP:
2582    case Op_CompareAndSwapN:
2583    {
2584      Node *adr = n->in(MemNode::Address);
2585      const Type *adr_type = phase->type(adr)->make_ptr();
2586#ifdef ASSERT
2587      if (!adr_type->isa_oopptr())
2588        assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2589#endif
2590
2591      assert(adr->is_AddP(), "expecting an AddP");
2592      Node *adr_base = get_addp_base(adr);
2593      Node *val = n->in(MemNode::ValueIn)->uncast();
2594      // For everything "adr_base" could point to, create a deferred edge
2595      // to "val" from each field with the same offset.
2596      VectorSet ptset(Thread::current()->resource_area());
2597      PointsTo(ptset, adr_base, phase);
2598      for( VectorSetI i(&ptset); i.test(); ++i ) {
2599        uint pt = i.elem;
2600        add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2601      }
2602      break;
2603    }
2604    case Op_AryEq:
2605    case Op_StrComp:
2606    case Op_StrEquals:
2607    case Op_StrIndexOf:
2608    {
2609      // char[] arrays passed to string intrinsic do not escape but
2610      // they are not scalar replaceable. Adjust escape state for them.
2611      // Start from in(2) edge since in(1) is memory edge.
2612      for (uint i = 2; i < n->req(); i++) {
2613        Node* adr = n->in(i)->uncast();
2614        const Type *at = phase->type(adr);
2615        if (!adr->is_top() && at->isa_ptr()) {
2616          assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
2617                 at->isa_ptr() != NULL, "expecting an Ptr");
2618          if (adr->is_AddP()) {
2619            adr = get_addp_base(adr);
2620          }
2621          // Mark as ArgEscape everything "adr" could point to.
2622          set_escape_state(adr->_idx, PointsToNode::ArgEscape);
2623        }
2624      }
2625      _processed.set(n_idx);
2626      break;
2627    }
2628    case Op_ThreadLocal:
2629    {
2630      assert(false, "Op_ThreadLocal");
2631      break;
2632    }
2633    default:
2634      // This method should be called only for EA specific nodes.
2635      ShouldNotReachHere();
2636  }
2637}
2638
2639#ifndef PRODUCT
2640void ConnectionGraph::dump() {
2641  PhaseGVN  *igvn = _compile->initial_gvn();
2642  bool first = true;
2643
2644  uint size = nodes_size();
2645  for (uint ni = 0; ni < size; ni++) {
2646    PointsToNode *ptn = ptnode_adr(ni);
2647    PointsToNode::NodeType ptn_type = ptn->node_type();
2648
2649    if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2650      continue;
2651    PointsToNode::EscapeState es = escape_state(ptn->_node, igvn);
2652    if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2653      if (first) {
2654        tty->cr();
2655        tty->print("======== Connection graph for ");
2656        _compile->method()->print_short_name();
2657        tty->cr();
2658        first = false;
2659      }
2660      tty->print("%6d ", ni);
2661      ptn->dump();
2662      // Print all locals which reference this allocation
2663      for (uint li = ni; li < size; li++) {
2664        PointsToNode *ptn_loc = ptnode_adr(li);
2665        PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2666        if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2667             ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2668          ptnode_adr(li)->dump(false);
2669        }
2670      }
2671      if (Verbose) {
2672        // Print all fields which reference this allocation
2673        for (uint i = 0; i < ptn->edge_count(); i++) {
2674          uint ei = ptn->edge_target(i);
2675          ptnode_adr(ei)->dump(false);
2676        }
2677      }
2678      tty->cr();
2679    }
2680  }
2681}
2682#endif
2683