1 /*
   2  * Copyright 2005-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_escape.cpp.incl"
  27 
  28 void 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 
  37 void 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
  44 static const char *node_type_names[] = {
  45   "UnknownType",
  46   "JavaObject",
  47   "LocalVar",
  48   "Field"
  49 };
  50 
  51 static const char *esc_names[] = {
  52   "UnknownEscape",
  53   "NoEscape",
  54   "ArgEscape",
  55   "GlobalEscape"
  56 };
  57 
  58 static const char *edge_type_suffix[] = {
  59  "?", // UnknownEdge
  60  "P", // PointsToEdge
  61  "D", // DeferredEdge
  62  "F"  // FieldEdge
  63 };
  64 
  65 void 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 
  84 ConnectionGraph::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 
 109 void 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 
 119 void 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 
 132 int 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 
 150 void 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 
 163 void 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 
 170 void 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 
 185 PointsToNode::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 
 225 void 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 
 282 void 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 
 336 void 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".
 357 void 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 
 376 static 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 
 455 static 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 //
 501 bool 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   // Do nothing for such AddP node and don't process its users since
 528   // this code branch will go away.
 529   //
 530   if (!t->is_known_instance() &&
 531       !t->klass()->equals(base_t->klass()) &&
 532       t->klass()->is_subtype_of(base_t->klass())) {
 533      return false; // bail out
 534   }
 535 
 536   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
 537   // Do NOT remove the next call: ensure an new alias index is allocated
 538   // for the instance type
 539   int alias_idx = _compile->get_alias_index(tinst);
 540   igvn->set_type(addp, tinst);
 541   // record the allocation in the node map
 542   set_map(addp->_idx, get_map(base->_idx));
 543 
 544   // Set addp's Base and Address to 'base'.
 545   Node *abase = addp->in(AddPNode::Base);
 546   Node *adr   = addp->in(AddPNode::Address);
 547   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
 548       adr->in(0)->_idx == (uint)inst_id) {
 549     // Skip AddP cases #3 and #5.
 550   } else {
 551     assert(!abase->is_top(), "sanity"); // AddP case #3
 552     if (abase != base) {
 553       igvn->hash_delete(addp);
 554       addp->set_req(AddPNode::Base, base);
 555       if (abase == adr) {
 556         addp->set_req(AddPNode::Address, base);
 557       } else {
 558         // AddP case #4 (adr is array's element offset AddP node)
 559 #ifdef ASSERT
 560         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
 561         assert(adr->is_AddP() && atype != NULL &&
 562                atype->instance_id() == inst_id, "array's element offset should be processed first");
 563 #endif
 564       }
 565       igvn->hash_insert(addp);
 566     }
 567   }
 568   // Put on IGVN worklist since at least addp's type was changed above.
 569   record_for_optimizer(addp);
 570   return true;
 571 }
 572 
 573 //
 574 // Create a new version of orig_phi if necessary. Returns either the newly
 575 // created phi or an existing phi.  Sets create_new to indicate wheter  a new
 576 // phi was created.  Cache the last newly created phi in the node map.
 577 //
 578 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
 579   Compile *C = _compile;
 580   new_created = false;
 581   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
 582   // nothing to do if orig_phi is bottom memory or matches alias_idx
 583   if (phi_alias_idx == alias_idx) {
 584     return orig_phi;
 585   }
 586   // Have we recently created a Phi for this alias index?
 587   PhiNode *result = get_map_phi(orig_phi->_idx);
 588   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
 589     return result;
 590   }
 591   // Previous check may fail when the same wide memory Phi was split into Phis
 592   // for different memory slices. Search all Phis for this region.
 593   if (result != NULL) {
 594     Node* region = orig_phi->in(0);
 595     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
 596       Node* phi = region->fast_out(i);
 597       if (phi->is_Phi() &&
 598           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
 599         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
 600         return phi->as_Phi();
 601       }
 602     }
 603   }
 604   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
 605     if (C->do_escape_analysis() == true && !C->failing()) {
 606       // Retry compilation without escape analysis.
 607       // If this is the first failure, the sentinel string will "stick"
 608       // to the Compile object, and the C2Compiler will see it and retry.
 609       C->record_failure(C2Compiler::retry_no_escape_analysis());
 610     }
 611     return NULL;
 612   }
 613   orig_phi_worklist.append_if_missing(orig_phi);
 614   const TypePtr *atype = C->get_adr_type(alias_idx);
 615   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
 616   C->copy_node_notes_to(result, orig_phi);
 617   set_map_phi(orig_phi->_idx, result);
 618   igvn->set_type(result, result->bottom_type());
 619   record_for_optimizer(result);
 620   new_created = true;
 621   return result;
 622 }
 623 
 624 //
 625 // Return a new version  of Memory Phi "orig_phi" with the inputs having the
 626 // specified alias index.
 627 //
 628 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
 629 
 630   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
 631   Compile *C = _compile;
 632   bool new_phi_created;
 633   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
 634   if (!new_phi_created) {
 635     return result;
 636   }
 637 
 638   GrowableArray<PhiNode *>  phi_list;
 639   GrowableArray<uint>  cur_input;
 640 
 641   PhiNode *phi = orig_phi;
 642   uint idx = 1;
 643   bool finished = false;
 644   while(!finished) {
 645     while (idx < phi->req()) {
 646       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
 647       if (mem != NULL && mem->is_Phi()) {
 648         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
 649         if (new_phi_created) {
 650           // found an phi for which we created a new split, push current one on worklist and begin
 651           // processing new one
 652           phi_list.push(phi);
 653           cur_input.push(idx);
 654           phi = mem->as_Phi();
 655           result = newphi;
 656           idx = 1;
 657           continue;
 658         } else {
 659           mem = newphi;
 660         }
 661       }
 662       if (C->failing()) {
 663         return NULL;
 664       }
 665       result->set_req(idx++, mem);
 666     }
 667 #ifdef ASSERT
 668     // verify that the new Phi has an input for each input of the original
 669     assert( phi->req() == result->req(), "must have same number of inputs.");
 670     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
 671 #endif
 672     // Check if all new phi's inputs have specified alias index.
 673     // Otherwise use old phi.
 674     for (uint i = 1; i < phi->req(); i++) {
 675       Node* in = result->in(i);
 676       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
 677     }
 678     // we have finished processing a Phi, see if there are any more to do
 679     finished = (phi_list.length() == 0 );
 680     if (!finished) {
 681       phi = phi_list.pop();
 682       idx = cur_input.pop();
 683       PhiNode *prev_result = get_map_phi(phi->_idx);
 684       prev_result->set_req(idx++, result);
 685       result = prev_result;
 686     }
 687   }
 688   return result;
 689 }
 690 
 691 
 692 //
 693 // The next methods are derived from methods in MemNode.
 694 //
 695 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *tinst) {
 696   Node *mem = mmem;
 697   // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally
 698   // means an array I have not precisely typed yet.  Do not do any
 699   // alias stuff with it any time soon.
 700   if( tinst->base() != Type::AnyPtr &&
 701       !(tinst->klass()->is_java_lang_Object() &&
 702         tinst->offset() == Type::OffsetBot) ) {
 703     mem = mmem->memory_at(alias_idx);
 704     // Update input if it is progress over what we have now
 705   }
 706   return mem;
 707 }
 708 
 709 //
 710 // Search memory chain of "mem" to find a MemNode whose address
 711 // is the specified alias index.
 712 //
 713 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
 714   if (orig_mem == NULL)
 715     return orig_mem;
 716   Compile* C = phase->C;
 717   const TypeOopPtr *tinst = C->get_adr_type(alias_idx)->isa_oopptr();
 718   bool is_instance = (tinst != NULL) && tinst->is_known_instance();
 719   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 720   Node *prev = NULL;
 721   Node *result = orig_mem;
 722   while (prev != result) {
 723     prev = result;
 724     if (result == start_mem)
 725       break;  // hit one of our sentinels
 726     if (result->is_Mem()) {
 727       const Type *at = phase->type(result->in(MemNode::Address));
 728       if (at != Type::TOP) {
 729         assert (at->isa_ptr() != NULL, "pointer type required.");
 730         int idx = C->get_alias_index(at->is_ptr());
 731         if (idx == alias_idx)
 732           break;
 733       }
 734       result = result->in(MemNode::Memory);
 735     }
 736     if (!is_instance)
 737       continue;  // don't search further for non-instance types
 738     // skip over a call which does not affect this memory slice
 739     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
 740       Node *proj_in = result->in(0);
 741       if (proj_in->is_Allocate() && proj_in->_idx == (uint)tinst->instance_id()) {
 742         break;  // hit one of our sentinels
 743       } else if (proj_in->is_Call()) {
 744         CallNode *call = proj_in->as_Call();
 745         if (!call->may_modify(tinst, phase)) {
 746           result = call->in(TypeFunc::Memory);
 747         }
 748       } else if (proj_in->is_Initialize()) {
 749         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
 750         // Stop if this is the initialization for the object instance which
 751         // which contains this memory slice, otherwise skip over it.
 752         if (alloc == NULL || alloc->_idx != (uint)tinst->instance_id()) {
 753           result = proj_in->in(TypeFunc::Memory);
 754         }
 755       } else if (proj_in->is_MemBar()) {
 756         result = proj_in->in(TypeFunc::Memory);
 757       }
 758     } else if (result->is_MergeMem()) {
 759       MergeMemNode *mmem = result->as_MergeMem();
 760       result = step_through_mergemem(mmem, alias_idx, tinst);
 761       if (result == mmem->base_memory()) {
 762         // Didn't find instance memory, search through general slice recursively.
 763         result = mmem->memory_at(C->get_general_index(alias_idx));
 764         result = find_inst_mem(result, alias_idx, orig_phis, phase);
 765         if (C->failing()) {
 766           return NULL;
 767         }
 768         mmem->set_memory_at(alias_idx, result);
 769       }
 770     } else if (result->is_Phi() &&
 771                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
 772       Node *un = result->as_Phi()->unique_input(phase);
 773       if (un != NULL) {
 774         result = un;
 775       } else {
 776         break;
 777       }
 778     } else if (result->Opcode() == Op_SCMemProj) {
 779       assert(result->in(0)->is_LoadStore(), "sanity");
 780       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
 781       if (at != Type::TOP) {
 782         assert (at->isa_ptr() != NULL, "pointer type required.");
 783         int idx = C->get_alias_index(at->is_ptr());
 784         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
 785         break;
 786       }
 787       result = result->in(0)->in(MemNode::Memory);
 788     }
 789   }
 790   if (result->is_Phi()) {
 791     PhiNode *mphi = result->as_Phi();
 792     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
 793     const TypePtr *t = mphi->adr_type();
 794     if (C->get_alias_index(t) != alias_idx) {
 795       // Create a new Phi with the specified alias index type.
 796       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
 797     } else if (!is_instance) {
 798       // Push all non-instance Phis on the orig_phis worklist to update inputs
 799       // during Phase 4 if needed.
 800       orig_phis.append_if_missing(mphi);
 801     }
 802   }
 803   // the result is either MemNode, PhiNode, InitializeNode.
 804   return result;
 805 }
 806 
 807 
 808 //
 809 //  Convert the types of unescaped object to instance types where possible,
 810 //  propagate the new type information through the graph, and update memory
 811 //  edges and MergeMem inputs to reflect the new type.
 812 //
 813 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
 814 //  The processing is done in 4 phases:
 815 //
 816 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
 817 //            types for the CheckCastPP for allocations where possible.
 818 //            Propagate the the new types through users as follows:
 819 //               casts and Phi:  push users on alloc_worklist
 820 //               AddP:  cast Base and Address inputs to the instance type
 821 //                      push any AddP users on alloc_worklist and push any memnode
 822 //                      users onto memnode_worklist.
 823 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
 824 //            search the Memory chain for a store with the appropriate type
 825 //            address type.  If a Phi is found, create a new version with
 826 //            the appropriate memory slices from each of the Phi inputs.
 827 //            For stores, process the users as follows:
 828 //               MemNode:  push on memnode_worklist
 829 //               MergeMem: push on mergemem_worklist
 830 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
 831 //            moving the first node encountered of each  instance type to the
 832 //            the input corresponding to its alias index.
 833 //            appropriate memory slice.
 834 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
 835 //
 836 // In the following example, the CheckCastPP nodes are the cast of allocation
 837 // results and the allocation of node 29 is unescaped and eligible to be an
 838 // instance type.
 839 //
 840 // We start with:
 841 //
 842 //     7 Parm #memory
 843 //    10  ConI  "12"
 844 //    19  CheckCastPP   "Foo"
 845 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 846 //    29  CheckCastPP   "Foo"
 847 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
 848 //
 849 //    40  StoreP  25   7  20   ... alias_index=4
 850 //    50  StoreP  35  40  30   ... alias_index=4
 851 //    60  StoreP  45  50  20   ... alias_index=4
 852 //    70  LoadP    _  60  30   ... alias_index=4
 853 //    80  Phi     75  50  60   Memory alias_index=4
 854 //    90  LoadP    _  80  30   ... alias_index=4
 855 //   100  LoadP    _  80  20   ... alias_index=4
 856 //
 857 //
 858 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
 859 // and creating a new alias index for node 30.  This gives:
 860 //
 861 //     7 Parm #memory
 862 //    10  ConI  "12"
 863 //    19  CheckCastPP   "Foo"
 864 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 865 //    29  CheckCastPP   "Foo"  iid=24
 866 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
 867 //
 868 //    40  StoreP  25   7  20   ... alias_index=4
 869 //    50  StoreP  35  40  30   ... alias_index=6
 870 //    60  StoreP  45  50  20   ... alias_index=4
 871 //    70  LoadP    _  60  30   ... alias_index=6
 872 //    80  Phi     75  50  60   Memory alias_index=4
 873 //    90  LoadP    _  80  30   ... alias_index=6
 874 //   100  LoadP    _  80  20   ... alias_index=4
 875 //
 876 // In phase 2, new memory inputs are computed for the loads and stores,
 877 // And a new version of the phi is created.  In phase 4, the inputs to
 878 // node 80 are updated and then the memory nodes are updated with the
 879 // values computed in phase 2.  This results in:
 880 //
 881 //     7 Parm #memory
 882 //    10  ConI  "12"
 883 //    19  CheckCastPP   "Foo"
 884 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 885 //    29  CheckCastPP   "Foo"  iid=24
 886 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
 887 //
 888 //    40  StoreP  25  7   20   ... alias_index=4
 889 //    50  StoreP  35  7   30   ... alias_index=6
 890 //    60  StoreP  45  40  20   ... alias_index=4
 891 //    70  LoadP    _  50  30   ... alias_index=6
 892 //    80  Phi     75  40  60   Memory alias_index=4
 893 //   120  Phi     75  50  50   Memory alias_index=6
 894 //    90  LoadP    _ 120  30   ... alias_index=6
 895 //   100  LoadP    _  80  20   ... alias_index=4
 896 //
 897 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
 898   GrowableArray<Node *>  memnode_worklist;
 899   GrowableArray<Node *>  mergemem_worklist;
 900   GrowableArray<PhiNode *>  orig_phis;
 901   PhaseGVN  *igvn = _compile->initial_gvn();
 902   uint new_index_start = (uint) _compile->num_alias_types();
 903   VectorSet visited(Thread::current()->resource_area());
 904   VectorSet ptset(Thread::current()->resource_area());
 905 
 906 
 907   //  Phase 1:  Process possible allocations from alloc_worklist.
 908   //  Create instance types for the CheckCastPP for allocations where possible.
 909   //
 910   // (Note: don't forget to change the order of the second AddP node on
 911   //  the alloc_worklist if the order of the worklist processing is changed,
 912   //  see the comment in find_second_addp().)
 913   //
 914   while (alloc_worklist.length() != 0) {
 915     Node *n = alloc_worklist.pop();
 916     uint ni = n->_idx;
 917     const TypeOopPtr* tinst = NULL;
 918     if (n->is_Call()) {
 919       CallNode *alloc = n->as_Call();
 920       // copy escape information to call node
 921       PointsToNode* ptn = ptnode_adr(alloc->_idx);
 922       PointsToNode::EscapeState es = escape_state(alloc, igvn);
 923       // We have an allocation or call which returns a Java object,
 924       // see if it is unescaped.
 925       if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
 926         continue;
 927 
 928       // Find CheckCastPP for the allocate or for the return value of a call
 929       n = alloc->result_cast();
 930       if (n == NULL) {            // No uses except Initialize node
 931         if (alloc->is_Allocate()) {
 932           // Set the scalar_replaceable flag for allocation
 933           // so it could be eliminated if it has no uses.
 934           alloc->as_Allocate()->_is_scalar_replaceable = true;
 935         }
 936         continue;
 937       }
 938       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
 939         assert(!alloc->is_Allocate(), "allocation should have unique type");
 940         continue;
 941       }
 942 
 943       // The inline code for Object.clone() casts the allocation result to
 944       // java.lang.Object and then to the actual type of the allocated
 945       // object. Detect this case and use the second cast.
 946       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
 947       // the allocation result is cast to java.lang.Object and then
 948       // to the actual Array type.
 949       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
 950           && (alloc->is_AllocateArray() ||
 951               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
 952         Node *cast2 = NULL;
 953         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 954           Node *use = n->fast_out(i);
 955           if (use->is_CheckCastPP()) {
 956             cast2 = use;
 957             break;
 958           }
 959         }
 960         if (cast2 != NULL) {
 961           n = cast2;
 962         } else {
 963           // Non-scalar replaceable if the allocation type is unknown statically
 964           // (reflection allocation), the object can't be restored during
 965           // deoptimization without precise type.
 966           continue;
 967         }
 968       }
 969       if (alloc->is_Allocate()) {
 970         // Set the scalar_replaceable flag for allocation
 971         // so it could be eliminated.
 972         alloc->as_Allocate()->_is_scalar_replaceable = true;
 973       }
 974       set_escape_state(n->_idx, es);
 975       // in order for an object to be scalar-replaceable, it must be:
 976       //   - a direct allocation (not a call returning an object)
 977       //   - non-escaping
 978       //   - eligible to be a unique type
 979       //   - not determined to be ineligible by escape analysis
 980       set_map(alloc->_idx, n);
 981       set_map(n->_idx, alloc);
 982       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
 983       if (t == NULL)
 984         continue;  // not a TypeInstPtr
 985       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
 986       igvn->hash_delete(n);
 987       igvn->set_type(n,  tinst);
 988       n->raise_bottom_type(tinst);
 989       igvn->hash_insert(n);
 990       record_for_optimizer(n);
 991       if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
 992           (t->isa_instptr() || t->isa_aryptr())) {
 993 
 994         // First, put on the worklist all Field edges from Connection Graph
 995         // which is more accurate then putting immediate users from Ideal Graph.
 996         for (uint e = 0; e < ptn->edge_count(); e++) {
 997           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
 998           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
 999                  "only AddP nodes are Field edges in CG");
1000           if (use->outcnt() > 0) { // Don't process dead nodes
1001             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1002             if (addp2 != NULL) {
1003               assert(alloc->is_AllocateArray(),"array allocation was expected");
1004               alloc_worklist.append_if_missing(addp2);
1005             }
1006             alloc_worklist.append_if_missing(use);
1007           }
1008         }
1009 
1010         // An allocation may have an Initialize which has raw stores. Scan
1011         // the users of the raw allocation result and push AddP users
1012         // on alloc_worklist.
1013         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1014         assert (raw_result != NULL, "must have an allocation result");
1015         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1016           Node *use = raw_result->fast_out(i);
1017           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1018             Node* addp2 = find_second_addp(use, raw_result);
1019             if (addp2 != NULL) {
1020               assert(alloc->is_AllocateArray(),"array allocation was expected");
1021               alloc_worklist.append_if_missing(addp2);
1022             }
1023             alloc_worklist.append_if_missing(use);
1024           } else if (use->is_Initialize()) {
1025             memnode_worklist.append_if_missing(use);
1026           }
1027         }
1028       }
1029     } else if (n->is_AddP()) {
1030       ptset.Clear();
1031       PointsTo(ptset, get_addp_base(n), igvn);
1032       assert(ptset.Size() == 1, "AddP address is unique");
1033       uint elem = ptset.getelem(); // Allocation node's index
1034       if (elem == _phantom_object)
1035         continue; // Assume the value was set outside this method.
1036       Node *base = get_map(elem);  // CheckCastPP node
1037       if (!split_AddP(n, base, igvn)) continue; // wrong type
1038       tinst = igvn->type(base)->isa_oopptr();
1039     } else if (n->is_Phi() ||
1040                n->is_CheckCastPP() ||
1041                n->is_EncodeP() ||
1042                n->is_DecodeN() ||
1043                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1044       if (visited.test_set(n->_idx)) {
1045         assert(n->is_Phi(), "loops only through Phi's");
1046         continue;  // already processed
1047       }
1048       ptset.Clear();
1049       PointsTo(ptset, n, igvn);
1050       if (ptset.Size() == 1) {
1051         uint elem = ptset.getelem(); // Allocation node's index
1052         if (elem == _phantom_object)
1053           continue; // Assume the value was set outside this method.
1054         Node *val = get_map(elem);   // CheckCastPP node
1055         TypeNode *tn = n->as_Type();
1056         tinst = igvn->type(val)->isa_oopptr();
1057         assert(tinst != NULL && tinst->is_known_instance() &&
1058                (uint)tinst->instance_id() == elem , "instance type expected.");
1059 
1060         const Type *tn_type = igvn->type(tn);
1061         const TypeOopPtr *tn_t;
1062         if (tn_type->isa_narrowoop()) {
1063           tn_t = tn_type->make_ptr()->isa_oopptr();
1064         } else {
1065           tn_t = tn_type->isa_oopptr();
1066         }
1067 
1068         if (tn_t != NULL &&
1069             tinst->cast_to_instance_id(TypeOopPtr::InstanceBot)->higher_equal(tn_t)) {
1070           if (tn_type->isa_narrowoop()) {
1071             tn_type = tinst->make_narrowoop();
1072           } else {
1073             tn_type = tinst;
1074           }
1075           igvn->hash_delete(tn);
1076           igvn->set_type(tn, tn_type);
1077           tn->set_type(tn_type);
1078           igvn->hash_insert(tn);
1079           record_for_optimizer(n);
1080         } else {
1081           continue; // wrong type
1082         }
1083       }
1084     } else {
1085       continue;
1086     }
1087     // push users on appropriate worklist
1088     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1089       Node *use = n->fast_out(i);
1090       if(use->is_Mem() && use->in(MemNode::Address) == n) {
1091         memnode_worklist.append_if_missing(use);
1092       } else if (use->is_Initialize()) {
1093         memnode_worklist.append_if_missing(use);
1094       } else if (use->is_MergeMem()) {
1095         mergemem_worklist.append_if_missing(use);
1096       } else if (use->is_SafePoint() && tinst != NULL) {
1097         // Look for MergeMem nodes for calls which reference unique allocation
1098         // (through CheckCastPP nodes) even for debug info.
1099         Node* m = use->in(TypeFunc::Memory);
1100         uint iid = tinst->instance_id();
1101         while (m->is_Proj() && m->in(0)->is_SafePoint() &&
1102                m->in(0) != use && !m->in(0)->_idx != iid) {
1103           m = m->in(0)->in(TypeFunc::Memory);
1104         }
1105         if (m->is_MergeMem()) {
1106           mergemem_worklist.append_if_missing(m);
1107         }
1108       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1109         Node* addp2 = find_second_addp(use, n);
1110         if (addp2 != NULL) {
1111           alloc_worklist.append_if_missing(addp2);
1112         }
1113         alloc_worklist.append_if_missing(use);
1114       } else if (use->is_Phi() ||
1115                  use->is_CheckCastPP() ||
1116                  use->is_EncodeP() ||
1117                  use->is_DecodeN() ||
1118                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1119         alloc_worklist.append_if_missing(use);
1120       }
1121     }
1122 
1123   }
1124   // New alias types were created in split_AddP().
1125   uint new_index_end = (uint) _compile->num_alias_types();
1126 
1127   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
1128   //            compute new values for Memory inputs  (the Memory inputs are not
1129   //            actually updated until phase 4.)
1130   if (memnode_worklist.length() == 0)
1131     return;  // nothing to do
1132 
1133   while (memnode_worklist.length() != 0) {
1134     Node *n = memnode_worklist.pop();
1135     if (visited.test_set(n->_idx))
1136       continue;
1137     if (n->is_Phi()) {
1138       assert(n->as_Phi()->adr_type() != TypePtr::BOTTOM, "narrow memory slice required");
1139       // we don't need to do anything, but the users must be pushed if we haven't processed
1140       // this Phi before
1141     } else if (n->is_Initialize()) {
1142       // we don't need to do anything, but the users of the memory projection must be pushed
1143       n = n->as_Initialize()->proj_out(TypeFunc::Memory);
1144       if (n == NULL)
1145         continue;
1146     } else {
1147       assert(n->is_Mem(), "memory node required.");
1148       Node *addr = n->in(MemNode::Address);
1149       assert(addr->is_AddP(), "AddP required");
1150       const Type *addr_t = igvn->type(addr);
1151       if (addr_t == Type::TOP)
1152         continue;
1153       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1154       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1155       assert ((uint)alias_idx < new_index_end, "wrong alias index");
1156       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1157       if (_compile->failing()) {
1158         return;
1159       }
1160       if (mem != n->in(MemNode::Memory)) {
1161         set_map(n->_idx, mem);
1162         ptnode_adr(n->_idx)->_node = n;
1163       }
1164       if (n->is_Load()) {
1165         continue;  // don't push users
1166       } else if (n->is_LoadStore()) {
1167         // get the memory projection
1168         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1169           Node *use = n->fast_out(i);
1170           if (use->Opcode() == Op_SCMemProj) {
1171             n = use;
1172             break;
1173           }
1174         }
1175         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1176       }
1177     }
1178     // push user on appropriate worklist
1179     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1180       Node *use = n->fast_out(i);
1181       if (use->is_Phi()) {
1182         memnode_worklist.append_if_missing(use);
1183       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1184         memnode_worklist.append_if_missing(use);
1185       } else if (use->is_Initialize()) {
1186         memnode_worklist.append_if_missing(use);
1187       } else if (use->is_MergeMem()) {
1188         mergemem_worklist.append_if_missing(use);
1189       }
1190     }
1191   }
1192 
1193   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
1194   //            Walk each memory moving the first node encountered of each
1195   //            instance type to the the input corresponding to its alias index.
1196   while (mergemem_worklist.length() != 0) {
1197     Node *n = mergemem_worklist.pop();
1198     assert(n->is_MergeMem(), "MergeMem node required.");
1199     if (visited.test_set(n->_idx))
1200       continue;
1201     MergeMemNode *nmm = n->as_MergeMem();
1202     // Note: we don't want to use MergeMemStream here because we only want to
1203     //  scan inputs which exist at the start, not ones we add during processing.
1204     uint nslices = nmm->req();
1205     igvn->hash_delete(nmm);
1206     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1207       Node* mem = nmm->in(i);
1208       Node* cur = NULL;
1209       if (mem == NULL || mem->is_top())
1210         continue;
1211       while (mem->is_Mem()) {
1212         const Type *at = igvn->type(mem->in(MemNode::Address));
1213         if (at != Type::TOP) {
1214           assert (at->isa_ptr() != NULL, "pointer type required.");
1215           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1216           if (idx == i) {
1217             if (cur == NULL)
1218               cur = mem;
1219           } else {
1220             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1221               nmm->set_memory_at(idx, mem);
1222             }
1223           }
1224         }
1225         mem = mem->in(MemNode::Memory);
1226       }
1227       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1228       // Find any instance of the current type if we haven't encountered
1229       // a value of the instance along the chain.
1230       for (uint ni = new_index_start; ni < new_index_end; ni++) {
1231         if((uint)_compile->get_general_index(ni) == i) {
1232           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1233           if (nmm->is_empty_memory(m)) {
1234             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1235             if (_compile->failing()) {
1236               return;
1237             }
1238             nmm->set_memory_at(ni, result);
1239           }
1240         }
1241       }
1242     }
1243     // Find the rest of instances values
1244     for (uint ni = new_index_start; ni < new_index_end; ni++) {
1245       const TypeOopPtr *tinst = igvn->C->get_adr_type(ni)->isa_oopptr();
1246       Node* result = step_through_mergemem(nmm, ni, tinst);
1247       if (result == nmm->base_memory()) {
1248         // Didn't find instance memory, search through general slice recursively.
1249         result = nmm->memory_at(igvn->C->get_general_index(ni));
1250         result = find_inst_mem(result, ni, orig_phis, igvn);
1251         if (_compile->failing()) {
1252           return;
1253         }
1254         nmm->set_memory_at(ni, result);
1255       }
1256     }
1257     igvn->hash_insert(nmm);
1258     record_for_optimizer(nmm);
1259 
1260     // Propagate new memory slices to following MergeMem nodes.
1261     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1262       Node *use = n->fast_out(i);
1263       if (use->is_Call()) {
1264         CallNode* in = use->as_Call();
1265         if (in->proj_out(TypeFunc::Memory) != NULL) {
1266           Node* m = in->proj_out(TypeFunc::Memory);
1267           for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
1268             Node* mm = m->fast_out(j);
1269             if (mm->is_MergeMem()) {
1270               mergemem_worklist.append_if_missing(mm);
1271             }
1272           }
1273         }
1274         if (use->is_Allocate()) {
1275           use = use->as_Allocate()->initialization();
1276           if (use == NULL) {
1277             continue;
1278           }
1279         }
1280       }
1281       if (use->is_Initialize()) {
1282         InitializeNode* in = use->as_Initialize();
1283         if (in->proj_out(TypeFunc::Memory) != NULL) {
1284           Node* m = in->proj_out(TypeFunc::Memory);
1285           for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
1286             Node* mm = m->fast_out(j);
1287             if (mm->is_MergeMem()) {
1288               mergemem_worklist.append_if_missing(mm);
1289             }
1290           }
1291         }
1292       }
1293     }
1294   }
1295 
1296   //  Phase 4:  Update the inputs of non-instance memory Phis and
1297   //            the Memory input of memnodes
1298   // First update the inputs of any non-instance Phi's from
1299   // which we split out an instance Phi.  Note we don't have
1300   // to recursively process Phi's encounted on the input memory
1301   // chains as is done in split_memory_phi() since they  will
1302   // also be processed here.
1303   for (int j = 0; j < orig_phis.length(); j++) {
1304     PhiNode *phi = orig_phis.at(j);
1305     int alias_idx = _compile->get_alias_index(phi->adr_type());
1306     igvn->hash_delete(phi);
1307     for (uint i = 1; i < phi->req(); i++) {
1308       Node *mem = phi->in(i);
1309       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1310       if (_compile->failing()) {
1311         return;
1312       }
1313       if (mem != new_mem) {
1314         phi->set_req(i, new_mem);
1315       }
1316     }
1317     igvn->hash_insert(phi);
1318     record_for_optimizer(phi);
1319   }
1320 
1321   // Update the memory inputs of MemNodes with the value we computed
1322   // in Phase 2.
1323   for (uint i = 0; i < nodes_size(); i++) {
1324     Node *nmem = get_map(i);
1325     if (nmem != NULL) {
1326       Node *n = ptnode_adr(i)->_node;
1327       if (n != NULL && n->is_Mem()) {
1328         igvn->hash_delete(n);
1329         n->set_req(MemNode::Memory, nmem);
1330         igvn->hash_insert(n);
1331         record_for_optimizer(n);
1332       }
1333     }
1334   }
1335 }
1336 
1337 bool ConnectionGraph::has_candidates(Compile *C) {
1338   // EA brings benefits only when the code has allocations and/or locks which
1339   // are represented by ideal Macro nodes.
1340   int cnt = C->macro_count();
1341   for( int i=0; i < cnt; i++ ) {
1342     Node *n = C->macro_node(i);
1343     if ( n->is_Allocate() )
1344       return true;
1345     if( n->is_Lock() ) {
1346       Node* obj = n->as_Lock()->obj_node()->uncast();
1347       if( !(obj->is_Parm() || obj->is_Con()) )
1348         return true;
1349     }
1350   }
1351   return false;
1352 }
1353 
1354 bool ConnectionGraph::compute_escape() {
1355   Compile* C = _compile;
1356 
1357   // 1. Populate Connection Graph (CG) with Ideal nodes.
1358 
1359   Unique_Node_List worklist_init;
1360   worklist_init.map(C->unique(), NULL);  // preallocate space
1361 
1362   // Initialize worklist
1363   if (C->root() != NULL) {
1364     worklist_init.push(C->root());
1365   }
1366 
1367   GrowableArray<int> cg_worklist;
1368   PhaseGVN* igvn = C->initial_gvn();
1369   bool has_allocations = false;
1370 
1371   // Push all useful nodes onto CG list and set their type.
1372   for( uint next = 0; next < worklist_init.size(); ++next ) {
1373     Node* n = worklist_init.at(next);
1374     record_for_escape_analysis(n, igvn);
1375     // Only allocations and java static calls results are checked
1376     // for an escape status. See process_call_result() below.
1377     if (n->is_Allocate() || n->is_CallStaticJava() &&
1378         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1379       has_allocations = true;
1380     }
1381     if(n->is_AddP())
1382       cg_worklist.append(n->_idx);
1383     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1384       Node* m = n->fast_out(i);   // Get user
1385       worklist_init.push(m);
1386     }
1387   }
1388 
1389   if (!has_allocations) {
1390     _collecting = false;
1391     return false; // Nothing to do.
1392   }
1393 
1394   // 2. First pass to create simple CG edges (doesn't require to walk CG).
1395   uint delayed_size = _delayed_worklist.size();
1396   for( uint next = 0; next < delayed_size; ++next ) {
1397     Node* n = _delayed_worklist.at(next);
1398     build_connection_graph(n, igvn);
1399   }
1400 
1401   // 3. Pass to create fields edges (Allocate -F-> AddP).
1402   uint cg_length = cg_worklist.length();
1403   for( uint next = 0; next < cg_length; ++next ) {
1404     int ni = cg_worklist.at(next);
1405     build_connection_graph(ptnode_adr(ni)->_node, igvn);
1406   }
1407 
1408   cg_worklist.clear();
1409   cg_worklist.append(_phantom_object);
1410 
1411   // 4. Build Connection Graph which need
1412   //    to walk the connection graph.
1413   for (uint ni = 0; ni < nodes_size(); ni++) {
1414     PointsToNode* ptn = ptnode_adr(ni);
1415     Node *n = ptn->_node;
1416     if (n != NULL) { // Call, AddP, LoadP, StoreP
1417       build_connection_graph(n, igvn);
1418       if (ptn->node_type() != PointsToNode::UnknownType)
1419         cg_worklist.append(n->_idx); // Collect CG nodes
1420     }
1421   }
1422 
1423   VectorSet ptset(Thread::current()->resource_area());
1424   GrowableArray<uint>  deferred_edges;
1425   VectorSet visited(Thread::current()->resource_area());
1426 
1427   // 5. Remove deferred edges from the graph and collect
1428   //    information needed for type splitting.
1429   cg_length = cg_worklist.length();
1430   for( uint next = 0; next < cg_length; ++next ) {
1431     int ni = cg_worklist.at(next);
1432     PointsToNode* ptn = ptnode_adr(ni);
1433     PointsToNode::NodeType nt = ptn->node_type();
1434     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1435       remove_deferred(ni, &deferred_edges, &visited);
1436       Node *n = ptn->_node;
1437       if (n->is_AddP()) {
1438         // Search for objects which are not scalar replaceable.
1439         // Mark their escape state as ArgEscape to propagate the state
1440         // to referenced objects.
1441         // Note: currently there are no difference in compiler optimizations
1442         // for ArgEscape objects and NoEscape objects which are not
1443         // scalar replaceable.
1444 
1445         int offset = ptn->offset();
1446         Node *base = get_addp_base(n);
1447         ptset.Clear();
1448         PointsTo(ptset, base, igvn);
1449         int ptset_size = ptset.Size();
1450 
1451         // Check if a field's initializing value is recorded and add
1452         // a corresponding NULL field's value if it is not recorded.
1453         // Connection Graph does not record a default initialization by NULL
1454         // captured by Initialize node.
1455         //
1456         // Note: it will disable scalar replacement in some cases:
1457         //
1458         //    Point p[] = new Point[1];
1459         //    p[0] = new Point(); // Will be not scalar replaced
1460         //
1461         // but it will save us from incorrect optimizations in next cases:
1462         //
1463         //    Point p[] = new Point[1];
1464         //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1465         //
1466         // Without a control flow analysis we can't distinguish above cases.
1467         //
1468         if (offset != Type::OffsetBot && ptset_size == 1) {
1469           uint elem = ptset.getelem(); // Allocation node's index
1470           // It does not matter if it is not Allocation node since
1471           // only non-escaping allocations are scalar replaced.
1472           if (ptnode_adr(elem)->_node->is_Allocate() &&
1473               ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
1474             AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
1475             InitializeNode* ini = alloc->initialization();
1476             Node* value = NULL;
1477             if (ini != NULL) {
1478               BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1479               Node* store = ini->find_captured_store(offset, type2aelembytes(ft), igvn);
1480               if (store != NULL && store->is_Store())
1481                 value = store->in(MemNode::ValueIn);
1482             }
1483             if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1484               // A field's initializing value was not recorded. Add NULL.
1485               uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1486               add_pointsto_edge(ni, null_idx);
1487             }
1488           }
1489         }
1490 
1491         // An object is not scalar replaceable if the field which may point
1492         // to it has unknown offset (unknown element of an array of objects).
1493         //
1494         if (offset == Type::OffsetBot) {
1495           uint e_cnt = ptn->edge_count();
1496           for (uint ei = 0; ei < e_cnt; ei++) {
1497             uint npi = ptn->edge_target(ei);
1498             set_escape_state(npi, PointsToNode::ArgEscape);
1499             ptnode_adr(npi)->_scalar_replaceable = false;
1500           }
1501         }
1502 
1503         // Currently an object is not scalar replaceable if a LoadStore node
1504         // access its field since the field value is unknown after it.
1505         //
1506         bool has_LoadStore = false;
1507         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1508           Node *use = n->fast_out(i);
1509           if (use->is_LoadStore()) {
1510             has_LoadStore = true;
1511             break;
1512           }
1513         }
1514         // An object is not scalar replaceable if the address points
1515         // to unknown field (unknown element for arrays, offset is OffsetBot).
1516         //
1517         // Or the address may point to more then one object. This may produce
1518         // the false positive result (set scalar_replaceable to false)
1519         // since the flow-insensitive escape analysis can't separate
1520         // the case when stores overwrite the field's value from the case
1521         // when stores happened on different control branches.
1522         //
1523         if (ptset_size > 1 || ptset_size != 0 &&
1524             (has_LoadStore || offset == Type::OffsetBot)) {
1525           for( VectorSetI j(&ptset); j.test(); ++j ) {
1526             set_escape_state(j.elem, PointsToNode::ArgEscape);
1527             ptnode_adr(j.elem)->_scalar_replaceable = false;
1528           }
1529         }
1530       }
1531     }
1532   }
1533 
1534   // 6. Propagate escape states.
1535   GrowableArray<int>  worklist;
1536   bool has_non_escaping_obj = false;
1537 
1538   // push all GlobalEscape nodes on the worklist
1539   for( uint next = 0; next < cg_length; ++next ) {
1540     int nk = cg_worklist.at(next);
1541     if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
1542       worklist.push(nk);
1543   }
1544   // mark all nodes reachable from GlobalEscape nodes
1545   while(worklist.length() > 0) {
1546     PointsToNode* ptn = ptnode_adr(worklist.pop());
1547     uint e_cnt = ptn->edge_count();
1548     for (uint ei = 0; ei < e_cnt; ei++) {
1549       uint npi = ptn->edge_target(ei);
1550       PointsToNode *np = ptnode_adr(npi);
1551       if (np->escape_state() < PointsToNode::GlobalEscape) {
1552         np->set_escape_state(PointsToNode::GlobalEscape);
1553         worklist.push(npi);
1554       }
1555     }
1556   }
1557 
1558   // push all ArgEscape nodes on the worklist
1559   for( uint next = 0; next < cg_length; ++next ) {
1560     int nk = cg_worklist.at(next);
1561     if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
1562       worklist.push(nk);
1563   }
1564   // mark all nodes reachable from ArgEscape nodes
1565   while(worklist.length() > 0) {
1566     PointsToNode* ptn = ptnode_adr(worklist.pop());
1567     if (ptn->node_type() == PointsToNode::JavaObject)
1568       has_non_escaping_obj = true; // Non GlobalEscape
1569     uint e_cnt = ptn->edge_count();
1570     for (uint ei = 0; ei < e_cnt; ei++) {
1571       uint npi = ptn->edge_target(ei);
1572       PointsToNode *np = ptnode_adr(npi);
1573       if (np->escape_state() < PointsToNode::ArgEscape) {
1574         np->set_escape_state(PointsToNode::ArgEscape);
1575         worklist.push(npi);
1576       }
1577     }
1578   }
1579 
1580   GrowableArray<Node*> alloc_worklist;
1581 
1582   // push all NoEscape nodes on the worklist
1583   for( uint next = 0; next < cg_length; ++next ) {
1584     int nk = cg_worklist.at(next);
1585     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1586       worklist.push(nk);
1587   }
1588   // mark all nodes reachable from NoEscape nodes
1589   while(worklist.length() > 0) {
1590     PointsToNode* ptn = ptnode_adr(worklist.pop());
1591     if (ptn->node_type() == PointsToNode::JavaObject)
1592       has_non_escaping_obj = true; // Non GlobalEscape
1593     Node* n = ptn->_node;
1594     if (n->is_Allocate() && ptn->_scalar_replaceable ) {
1595       // Push scalar replaceable allocations on alloc_worklist
1596       // for processing in split_unique_types().
1597       alloc_worklist.append(n);
1598     }
1599     uint e_cnt = ptn->edge_count();
1600     for (uint ei = 0; ei < e_cnt; ei++) {
1601       uint npi = ptn->edge_target(ei);
1602       PointsToNode *np = ptnode_adr(npi);
1603       if (np->escape_state() < PointsToNode::NoEscape) {
1604         np->set_escape_state(PointsToNode::NoEscape);
1605         worklist.push(npi);
1606       }
1607     }
1608   }
1609 
1610   _collecting = false;
1611   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1612 
1613   bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1614   if ( has_scalar_replaceable_candidates &&
1615        C->AliasLevel() >= 3 && EliminateAllocations ) {
1616 
1617     // Now use the escape information to create unique types for
1618     // scalar replaceable objects.
1619     split_unique_types(alloc_worklist);
1620 
1621     if (C->failing())  return false;
1622 
1623     // Clean up after split unique types.
1624     ResourceMark rm;
1625     PhaseRemoveUseless pru(C->initial_gvn(), C->for_igvn());
1626 
1627     C->print_method("After Escape Analysis", 2);
1628 
1629 #ifdef ASSERT
1630   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1631     tty->print("=== No allocations eliminated for ");
1632     C->method()->print_short_name();
1633     if(!EliminateAllocations) {
1634       tty->print(" since EliminateAllocations is off ===");
1635     } else if(!has_scalar_replaceable_candidates) {
1636       tty->print(" since there are no scalar replaceable candidates ===");
1637     } else if(C->AliasLevel() < 3) {
1638       tty->print(" since AliasLevel < 3 ===");
1639     }
1640     tty->cr();
1641 #endif
1642   }
1643   return has_non_escaping_obj;
1644 }
1645 
1646 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1647 
1648     switch (call->Opcode()) {
1649 #ifdef ASSERT
1650     case Op_Allocate:
1651     case Op_AllocateArray:
1652     case Op_Lock:
1653     case Op_Unlock:
1654       assert(false, "should be done already");
1655       break;
1656 #endif
1657     case Op_CallLeafNoFP:
1658     {
1659       // Stub calls, objects do not escape but they are not scale replaceable.
1660       // Adjust escape state for outgoing arguments.
1661       const TypeTuple * d = call->tf()->domain();
1662       VectorSet ptset(Thread::current()->resource_area());
1663       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1664         const Type* at = d->field_at(i);
1665         Node *arg = call->in(i)->uncast();
1666         const Type *aat = phase->type(arg);
1667         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr()) {
1668           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1669                  aat->isa_ptr() != NULL, "expecting an Ptr");
1670           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1671           if (arg->is_AddP()) {
1672             //
1673             // The inline_native_clone() case when the arraycopy stub is called
1674             // after the allocation before Initialize and CheckCastPP nodes.
1675             //
1676             // Set AddP's base (Allocate) as not scalar replaceable since
1677             // pointer to the base (with offset) is passed as argument.
1678             //
1679             arg = get_addp_base(arg);
1680           }
1681           ptset.Clear();
1682           PointsTo(ptset, arg, phase);
1683           for( VectorSetI j(&ptset); j.test(); ++j ) {
1684             uint pt = j.elem;
1685             set_escape_state(pt, PointsToNode::ArgEscape);
1686           }
1687         }
1688       }
1689       break;
1690     }
1691 
1692     case Op_CallStaticJava:
1693     // For a static call, we know exactly what method is being called.
1694     // Use bytecode estimator to record the call's escape affects
1695     {
1696       ciMethod *meth = call->as_CallJava()->method();
1697       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1698       // fall-through if not a Java method or no analyzer information
1699       if (call_analyzer != NULL) {
1700         const TypeTuple * d = call->tf()->domain();
1701         VectorSet ptset(Thread::current()->resource_area());
1702         bool copy_dependencies = false;
1703         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1704           const Type* at = d->field_at(i);
1705           int k = i - TypeFunc::Parms;
1706 
1707           if (at->isa_oopptr() != NULL) {
1708             Node *arg = call->in(i)->uncast();
1709 
1710             bool global_escapes = false;
1711             bool fields_escapes = false;
1712             if (!call_analyzer->is_arg_stack(k)) {
1713               // The argument global escapes, mark everything it could point to
1714               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1715               global_escapes = true;
1716             } else {
1717               if (!call_analyzer->is_arg_local(k)) {
1718                 // The argument itself doesn't escape, but any fields might
1719                 fields_escapes = true;
1720               }
1721               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1722               copy_dependencies = true;
1723             }
1724 
1725             ptset.Clear();
1726             PointsTo(ptset, arg, phase);
1727             for( VectorSetI j(&ptset); j.test(); ++j ) {
1728               uint pt = j.elem;
1729               if (global_escapes) {
1730                 //The argument global escapes, mark everything it could point to
1731                 set_escape_state(pt, PointsToNode::GlobalEscape);
1732               } else {
1733                 if (fields_escapes) {
1734                   // The argument itself doesn't escape, but any fields might
1735                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
1736                 }
1737                 set_escape_state(pt, PointsToNode::ArgEscape);
1738               }
1739             }
1740           }
1741         }
1742         if (copy_dependencies)
1743           call_analyzer->copy_dependencies(_compile->dependencies());
1744         break;
1745       }
1746     }
1747 
1748     default:
1749     // Fall-through here if not a Java method or no analyzer information
1750     // or some other type of call, assume the worst case: all arguments
1751     // globally escape.
1752     {
1753       // adjust escape state for  outgoing arguments
1754       const TypeTuple * d = call->tf()->domain();
1755       VectorSet ptset(Thread::current()->resource_area());
1756       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1757         const Type* at = d->field_at(i);
1758         if (at->isa_oopptr() != NULL) {
1759           Node *arg = call->in(i)->uncast();
1760           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1761           ptset.Clear();
1762           PointsTo(ptset, arg, phase);
1763           for( VectorSetI j(&ptset); j.test(); ++j ) {
1764             uint pt = j.elem;
1765             set_escape_state(pt, PointsToNode::GlobalEscape);
1766           }
1767         }
1768       }
1769     }
1770   }
1771 }
1772 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
1773   CallNode   *call = resproj->in(0)->as_Call();
1774   uint    call_idx = call->_idx;
1775   uint resproj_idx = resproj->_idx;
1776 
1777   switch (call->Opcode()) {
1778     case Op_Allocate:
1779     {
1780       Node *k = call->in(AllocateNode::KlassNode);
1781       const TypeKlassPtr *kt;
1782       if (k->Opcode() == Op_LoadKlass) {
1783         kt = k->as_Load()->type()->isa_klassptr();
1784       } else {
1785         // Also works for DecodeN(LoadNKlass).
1786         kt = k->as_Type()->type()->isa_klassptr();
1787       }
1788       assert(kt != NULL, "TypeKlassPtr  required.");
1789       ciKlass* cik = kt->klass();
1790       ciInstanceKlass* ciik = cik->as_instance_klass();
1791 
1792       PointsToNode::EscapeState es;
1793       uint edge_to;
1794       if (cik->is_subclass_of(_compile->env()->Thread_klass()) || ciik->has_finalizer()) {
1795         es = PointsToNode::GlobalEscape;
1796         edge_to = _phantom_object; // Could not be worse
1797       } else {
1798         es = PointsToNode::NoEscape;
1799         edge_to = call_idx;
1800       }
1801       set_escape_state(call_idx, es);
1802       add_pointsto_edge(resproj_idx, edge_to);
1803       _processed.set(resproj_idx);
1804       break;
1805     }
1806 
1807     case Op_AllocateArray:
1808     {
1809       int length = call->in(AllocateNode::ALength)->find_int_con(-1);
1810       if (length < 0 || length > EliminateAllocationArraySizeLimit) {
1811         // Not scalar replaceable if the length is not constant or too big.
1812         ptnode_adr(call_idx)->_scalar_replaceable = false;
1813       }
1814       set_escape_state(call_idx, PointsToNode::NoEscape);
1815       add_pointsto_edge(resproj_idx, call_idx);
1816       _processed.set(resproj_idx);
1817       break;
1818     }
1819 
1820     case Op_CallStaticJava:
1821     // For a static call, we know exactly what method is being called.
1822     // Use bytecode estimator to record whether the call's return value escapes
1823     {
1824       bool done = true;
1825       const TypeTuple *r = call->tf()->range();
1826       const Type* ret_type = NULL;
1827 
1828       if (r->cnt() > TypeFunc::Parms)
1829         ret_type = r->field_at(TypeFunc::Parms);
1830 
1831       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
1832       //        _multianewarray functions return a TypeRawPtr.
1833       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
1834         _processed.set(resproj_idx);
1835         break;  // doesn't return a pointer type
1836       }
1837       ciMethod *meth = call->as_CallJava()->method();
1838       const TypeTuple * d = call->tf()->domain();
1839       if (meth == NULL) {
1840         // not a Java method, assume global escape
1841         set_escape_state(call_idx, PointsToNode::GlobalEscape);
1842         add_pointsto_edge(resproj_idx, _phantom_object);
1843       } else {
1844         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
1845         bool copy_dependencies = false;
1846 
1847         if (call_analyzer->is_return_allocated()) {
1848           // Returns a newly allocated unescaped object, simply
1849           // update dependency information.
1850           // Mark it as NoEscape so that objects referenced by
1851           // it's fields will be marked as NoEscape at least.
1852           set_escape_state(call_idx, PointsToNode::NoEscape);
1853           add_pointsto_edge(resproj_idx, call_idx);
1854           copy_dependencies = true;
1855         } else if (call_analyzer->is_return_local()) {
1856           // determine whether any arguments are returned
1857           set_escape_state(call_idx, PointsToNode::NoEscape);
1858           bool ret_arg = false;
1859           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1860             const Type* at = d->field_at(i);
1861 
1862             if (at->isa_oopptr() != NULL) {
1863               Node *arg = call->in(i)->uncast();
1864 
1865               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
1866                 ret_arg = true;
1867                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
1868                 if (arg_esp->node_type() == PointsToNode::UnknownType)
1869                   done = false;
1870                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
1871                   add_pointsto_edge(resproj_idx, arg->_idx);
1872                 else
1873                   add_deferred_edge(resproj_idx, arg->_idx);
1874                 arg_esp->_hidden_alias = true;
1875               }
1876             }
1877           }
1878           if (done && !ret_arg) {
1879             // Returns unknown object.
1880             set_escape_state(call_idx, PointsToNode::GlobalEscape);
1881             add_pointsto_edge(resproj_idx, _phantom_object);
1882           }
1883           copy_dependencies = true;
1884         } else {
1885           set_escape_state(call_idx, PointsToNode::GlobalEscape);
1886           add_pointsto_edge(resproj_idx, _phantom_object);
1887           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1888             const Type* at = d->field_at(i);
1889             if (at->isa_oopptr() != NULL) {
1890               Node *arg = call->in(i)->uncast();
1891               PointsToNode *arg_esp = ptnode_adr(arg->_idx);
1892               arg_esp->_hidden_alias = true;
1893             }
1894           }
1895         }
1896         if (copy_dependencies)
1897           call_analyzer->copy_dependencies(_compile->dependencies());
1898       }
1899       if (done)
1900         _processed.set(resproj_idx);
1901       break;
1902     }
1903 
1904     default:
1905     // Some other type of call, assume the worst case that the
1906     // returned value, if any, globally escapes.
1907     {
1908       const TypeTuple *r = call->tf()->range();
1909       if (r->cnt() > TypeFunc::Parms) {
1910         const Type* ret_type = r->field_at(TypeFunc::Parms);
1911 
1912         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
1913         //        _multianewarray functions return a TypeRawPtr.
1914         if (ret_type->isa_ptr() != NULL) {
1915           set_escape_state(call_idx, PointsToNode::GlobalEscape);
1916           add_pointsto_edge(resproj_idx, _phantom_object);
1917         }
1918       }
1919       _processed.set(resproj_idx);
1920     }
1921   }
1922 }
1923 
1924 // Populate Connection Graph with Ideal nodes and create simple
1925 // connection graph edges (do not need to check the node_type of inputs
1926 // or to call PointsTo() to walk the connection graph).
1927 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
1928   if (_processed.test(n->_idx))
1929     return; // No need to redefine node's state.
1930 
1931   if (n->is_Call()) {
1932     // Arguments to allocation and locking don't escape.
1933     if (n->is_Allocate()) {
1934       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
1935       record_for_optimizer(n);
1936     } else if (n->is_Lock() || n->is_Unlock()) {
1937       // Put Lock and Unlock nodes on IGVN worklist to process them during
1938       // the first IGVN optimization when escape information is still available.
1939       record_for_optimizer(n);
1940       _processed.set(n->_idx);
1941     } else {
1942       // Have to process call's arguments first.
1943       PointsToNode::NodeType nt = PointsToNode::UnknownType;
1944 
1945       // Check if a call returns an object.
1946       const TypeTuple *r = n->as_Call()->tf()->range();
1947       if (n->is_CallStaticJava() && r->cnt() > TypeFunc::Parms &&
1948           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
1949         // Note:  use isa_ptr() instead of isa_oopptr() here because
1950         //        the _multianewarray functions return a TypeRawPtr.
1951         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
1952           nt = PointsToNode::JavaObject;
1953         }
1954       }
1955       add_node(n, nt, PointsToNode::UnknownEscape, false);
1956     }
1957     return;
1958   }
1959 
1960   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1961   // ThreadLocal has RawPrt type.
1962   switch (n->Opcode()) {
1963     case Op_AddP:
1964     {
1965       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
1966       break;
1967     }
1968     case Op_CastX2P:
1969     { // "Unsafe" memory access.
1970       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1971       break;
1972     }
1973     case Op_CastPP:
1974     case Op_CheckCastPP:
1975     case Op_EncodeP:
1976     case Op_DecodeN:
1977     {
1978       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
1979       int ti = n->in(1)->_idx;
1980       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
1981       if (nt == PointsToNode::UnknownType) {
1982         _delayed_worklist.push(n); // Process it later.
1983         break;
1984       } else if (nt == PointsToNode::JavaObject) {
1985         add_pointsto_edge(n->_idx, ti);
1986       } else {
1987         add_deferred_edge(n->_idx, ti);
1988       }
1989       _processed.set(n->_idx);
1990       break;
1991     }
1992     case Op_ConP:
1993     {
1994       // assume all pointer constants globally escape except for null
1995       PointsToNode::EscapeState es;
1996       if (phase->type(n) == TypePtr::NULL_PTR)
1997         es = PointsToNode::NoEscape;
1998       else
1999         es = PointsToNode::GlobalEscape;
2000 
2001       add_node(n, PointsToNode::JavaObject, es, true);
2002       break;
2003     }
2004     case Op_ConN:
2005     {
2006       // assume all narrow oop constants globally escape except for null
2007       PointsToNode::EscapeState es;
2008       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2009         es = PointsToNode::NoEscape;
2010       else
2011         es = PointsToNode::GlobalEscape;
2012 
2013       add_node(n, PointsToNode::JavaObject, es, true);
2014       break;
2015     }
2016     case Op_CreateEx:
2017     {
2018       // assume that all exception objects globally escape
2019       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2020       break;
2021     }
2022     case Op_LoadKlass:
2023     case Op_LoadNKlass:
2024     {
2025       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2026       break;
2027     }
2028     case Op_LoadP:
2029     case Op_LoadN:
2030     {
2031       const Type *t = phase->type(n);
2032       if (t->make_ptr() == NULL) {
2033         _processed.set(n->_idx);
2034         return;
2035       }
2036       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2037       break;
2038     }
2039     case Op_Parm:
2040     {
2041       _processed.set(n->_idx); // No need to redefine it state.
2042       uint con = n->as_Proj()->_con;
2043       if (con < TypeFunc::Parms)
2044         return;
2045       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2046       if (t->isa_ptr() == NULL)
2047         return;
2048       // We have to assume all input parameters globally escape
2049       // (Note: passing 'false' since _processed is already set).
2050       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2051       break;
2052     }
2053     case Op_Phi:
2054     {
2055       const Type *t = n->as_Phi()->type();
2056       if (t->make_ptr() == NULL) {
2057         // nothing to do if not an oop or narrow oop
2058         _processed.set(n->_idx);
2059         return;
2060       }
2061       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2062       uint i;
2063       for (i = 1; i < n->req() ; i++) {
2064         Node* in = n->in(i);
2065         if (in == NULL)
2066           continue;  // ignore NULL
2067         in = in->uncast();
2068         if (in->is_top() || in == n)
2069           continue;  // ignore top or inputs which go back this node
2070         int ti = in->_idx;
2071         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2072         if (nt == PointsToNode::UnknownType) {
2073           break;
2074         } else if (nt == PointsToNode::JavaObject) {
2075           add_pointsto_edge(n->_idx, ti);
2076         } else {
2077           add_deferred_edge(n->_idx, ti);
2078         }
2079       }
2080       if (i >= n->req())
2081         _processed.set(n->_idx);
2082       else
2083         _delayed_worklist.push(n);
2084       break;
2085     }
2086     case Op_Proj:
2087     {
2088       // we are only interested in the result projection from a call
2089       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2090         add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2091         process_call_result(n->as_Proj(), phase);
2092         if (!_processed.test(n->_idx)) {
2093           // The call's result may need to be processed later if the call
2094           // returns it's argument and the argument is not processed yet.
2095           _delayed_worklist.push(n);
2096         }
2097       } else {
2098         _processed.set(n->_idx);
2099       }
2100       break;
2101     }
2102     case Op_Return:
2103     {
2104       if( n->req() > TypeFunc::Parms &&
2105           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2106         // Treat Return value as LocalVar with GlobalEscape escape state.
2107         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2108         int ti = n->in(TypeFunc::Parms)->_idx;
2109         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2110         if (nt == PointsToNode::UnknownType) {
2111           _delayed_worklist.push(n); // Process it later.
2112           break;
2113         } else if (nt == PointsToNode::JavaObject) {
2114           add_pointsto_edge(n->_idx, ti);
2115         } else {
2116           add_deferred_edge(n->_idx, ti);
2117         }
2118       }
2119       _processed.set(n->_idx);
2120       break;
2121     }
2122     case Op_StoreP:
2123     case Op_StoreN:
2124     {
2125       const Type *adr_type = phase->type(n->in(MemNode::Address));
2126       adr_type = adr_type->make_ptr();
2127       if (adr_type->isa_oopptr()) {
2128         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2129       } else {
2130         Node* adr = n->in(MemNode::Address);
2131         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2132             adr->in(AddPNode::Address)->is_Proj() &&
2133             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2134           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2135           // We are computing a raw address for a store captured
2136           // by an Initialize compute an appropriate address type.
2137           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2138           assert(offs != Type::OffsetBot, "offset must be a constant");
2139         } else {
2140           _processed.set(n->_idx);
2141           return;
2142         }
2143       }
2144       break;
2145     }
2146     case Op_StorePConditional:
2147     case Op_CompareAndSwapP:
2148     case Op_CompareAndSwapN:
2149     {
2150       const Type *adr_type = phase->type(n->in(MemNode::Address));
2151       adr_type = adr_type->make_ptr();
2152       if (adr_type->isa_oopptr()) {
2153         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2154       } else {
2155         _processed.set(n->_idx);
2156         return;
2157       }
2158       break;
2159     }
2160     case Op_ThreadLocal:
2161     {
2162       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2163       break;
2164     }
2165     default:
2166       ;
2167       // nothing to do
2168   }
2169   return;
2170 }
2171 
2172 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2173   uint n_idx = n->_idx;
2174 
2175   // Don't set processed bit for AddP, LoadP, StoreP since
2176   // they may need more then one pass to process.
2177   if (_processed.test(n_idx))
2178     return; // No need to redefine node's state.
2179 
2180   if (n->is_Call()) {
2181     CallNode *call = n->as_Call();
2182     process_call_arguments(call, phase);
2183     _processed.set(n_idx);
2184     return;
2185   }
2186 
2187   switch (n->Opcode()) {
2188     case Op_AddP:
2189     {
2190       Node *base = get_addp_base(n);
2191       // Create a field edge to this node from everything base could point to.
2192       VectorSet ptset(Thread::current()->resource_area());
2193       PointsTo(ptset, base, phase);
2194       for( VectorSetI i(&ptset); i.test(); ++i ) {
2195         uint pt = i.elem;
2196         add_field_edge(pt, n_idx, address_offset(n, phase));
2197       }
2198       break;
2199     }
2200     case Op_CastX2P:
2201     {
2202       assert(false, "Op_CastX2P");
2203       break;
2204     }
2205     case Op_CastPP:
2206     case Op_CheckCastPP:
2207     case Op_EncodeP:
2208     case Op_DecodeN:
2209     {
2210       int ti = n->in(1)->_idx;
2211       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2212         add_pointsto_edge(n_idx, ti);
2213       } else {
2214         add_deferred_edge(n_idx, ti);
2215       }
2216       _processed.set(n_idx);
2217       break;
2218     }
2219     case Op_ConP:
2220     {
2221       assert(false, "Op_ConP");
2222       break;
2223     }
2224     case Op_ConN:
2225     {
2226       assert(false, "Op_ConN");
2227       break;
2228     }
2229     case Op_CreateEx:
2230     {
2231       assert(false, "Op_CreateEx");
2232       break;
2233     }
2234     case Op_LoadKlass:
2235     case Op_LoadNKlass:
2236     {
2237       assert(false, "Op_LoadKlass");
2238       break;
2239     }
2240     case Op_LoadP:
2241     case Op_LoadN:
2242     {
2243       const Type *t = phase->type(n);
2244 #ifdef ASSERT
2245       if (t->make_ptr() == NULL)
2246         assert(false, "Op_LoadP");
2247 #endif
2248 
2249       Node* adr = n->in(MemNode::Address)->uncast();
2250       const Type *adr_type = phase->type(adr);
2251       Node* adr_base;
2252       if (adr->is_AddP()) {
2253         adr_base = get_addp_base(adr);
2254       } else {
2255         adr_base = adr;
2256       }
2257 
2258       // For everything "adr_base" could point to, create a deferred edge from
2259       // this node to each field with the same offset.
2260       VectorSet ptset(Thread::current()->resource_area());
2261       PointsTo(ptset, adr_base, phase);
2262       int offset = address_offset(adr, phase);
2263       for( VectorSetI i(&ptset); i.test(); ++i ) {
2264         uint pt = i.elem;
2265         add_deferred_edge_to_fields(n_idx, pt, offset);
2266       }
2267       break;
2268     }
2269     case Op_Parm:
2270     {
2271       assert(false, "Op_Parm");
2272       break;
2273     }
2274     case Op_Phi:
2275     {
2276 #ifdef ASSERT
2277       const Type *t = n->as_Phi()->type();
2278       if (t->make_ptr() == NULL)
2279         assert(false, "Op_Phi");
2280 #endif
2281       for (uint i = 1; i < n->req() ; i++) {
2282         Node* in = n->in(i);
2283         if (in == NULL)
2284           continue;  // ignore NULL
2285         in = in->uncast();
2286         if (in->is_top() || in == n)
2287           continue;  // ignore top or inputs which go back this node
2288         int ti = in->_idx;
2289         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2290         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2291         if (nt == PointsToNode::JavaObject) {
2292           add_pointsto_edge(n_idx, ti);
2293         } else {
2294           add_deferred_edge(n_idx, ti);
2295         }
2296       }
2297       _processed.set(n_idx);
2298       break;
2299     }
2300     case Op_Proj:
2301     {
2302       // we are only interested in the result projection from a call
2303       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2304         process_call_result(n->as_Proj(), phase);
2305         assert(_processed.test(n_idx), "all call results should be processed");
2306       } else {
2307         assert(false, "Op_Proj");
2308       }
2309       break;
2310     }
2311     case Op_Return:
2312     {
2313 #ifdef ASSERT
2314       if( n->req() <= TypeFunc::Parms ||
2315           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2316         assert(false, "Op_Return");
2317       }
2318 #endif
2319       int ti = n->in(TypeFunc::Parms)->_idx;
2320       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2321         add_pointsto_edge(n_idx, ti);
2322       } else {
2323         add_deferred_edge(n_idx, ti);
2324       }
2325       _processed.set(n_idx);
2326       break;
2327     }
2328     case Op_StoreP:
2329     case Op_StoreN:
2330     case Op_StorePConditional:
2331     case Op_CompareAndSwapP:
2332     case Op_CompareAndSwapN:
2333     {
2334       Node *adr = n->in(MemNode::Address);
2335       const Type *adr_type = phase->type(adr)->make_ptr();
2336 #ifdef ASSERT
2337       if (!adr_type->isa_oopptr())
2338         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2339 #endif
2340 
2341       assert(adr->is_AddP(), "expecting an AddP");
2342       Node *adr_base = get_addp_base(adr);
2343       Node *val = n->in(MemNode::ValueIn)->uncast();
2344       // For everything "adr_base" could point to, create a deferred edge
2345       // to "val" from each field with the same offset.
2346       VectorSet ptset(Thread::current()->resource_area());
2347       PointsTo(ptset, adr_base, phase);
2348       for( VectorSetI i(&ptset); i.test(); ++i ) {
2349         uint pt = i.elem;
2350         add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2351       }
2352       break;
2353     }
2354     case Op_ThreadLocal:
2355     {
2356       assert(false, "Op_ThreadLocal");
2357       break;
2358     }
2359     default:
2360       ;
2361       // nothing to do
2362   }
2363 }
2364 
2365 #ifndef PRODUCT
2366 void ConnectionGraph::dump() {
2367   PhaseGVN  *igvn = _compile->initial_gvn();
2368   bool first = true;
2369 
2370   uint size = nodes_size();
2371   for (uint ni = 0; ni < size; ni++) {
2372     PointsToNode *ptn = ptnode_adr(ni);
2373     PointsToNode::NodeType ptn_type = ptn->node_type();
2374 
2375     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2376       continue;
2377     PointsToNode::EscapeState es = escape_state(ptn->_node, igvn);
2378     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2379       if (first) {
2380         tty->cr();
2381         tty->print("======== Connection graph for ");
2382         _compile->method()->print_short_name();
2383         tty->cr();
2384         first = false;
2385       }
2386       tty->print("%6d ", ni);
2387       ptn->dump();
2388       // Print all locals which reference this allocation
2389       for (uint li = ni; li < size; li++) {
2390         PointsToNode *ptn_loc = ptnode_adr(li);
2391         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2392         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2393              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2394           ptnode_adr(li)->dump(false);
2395         }
2396       }
2397       if (Verbose) {
2398         // Print all fields which reference this allocation
2399         for (uint i = 0; i < ptn->edge_count(); i++) {
2400           uint ei = ptn->edge_target(i);
2401           ptnode_adr(ei)->dump(false);
2402         }
2403       }
2404       tty->cr();
2405     }
2406   }
2407 }
2408 #endif