1 /*
   2  * Copyright 2005-2006 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 uint PointsToNode::edge_target(uint e) const {
  29   assert(_edges != NULL && e < (uint)_edges->length(), "valid edge index");
  30   return (_edges->at(e) >> EdgeShift);
  31 }
  32 
  33 PointsToNode::EdgeType PointsToNode::edge_type(uint e) const {
  34   assert(_edges != NULL && e < (uint)_edges->length(), "valid edge index");
  35   return (EdgeType) (_edges->at(e) & EdgeMask);
  36 }
  37 
  38 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
  39   uint v = (targIdx << EdgeShift) + ((uint) et);
  40   if (_edges == NULL) {
  41      Arena *a = Compile::current()->comp_arena();
  42     _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
  43   }
  44   _edges->append_if_missing(v);
  45 }
  46 
  47 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
  48   uint v = (targIdx << EdgeShift) + ((uint) et);
  49 
  50   _edges->remove(v);
  51 }
  52 
  53 #ifndef PRODUCT
  54 static char *node_type_names[] = {
  55   "UnknownType",
  56   "JavaObject",
  57   "LocalVar",
  58   "Field"
  59 };
  60 
  61 static char *esc_names[] = {
  62   "UnknownEscape",
  63   "NoEscape",
  64   "ArgEscape",
  65   "GlobalEscape"
  66 };
  67 
  68 static char *edge_type_suffix[] = {
  69  "?", // UnknownEdge
  70  "P", // PointsToEdge
  71  "D", // DeferredEdge
  72  "F"  // FieldEdge
  73 };
  74 
  75 void PointsToNode::dump() const {
  76   NodeType nt = node_type();
  77   EscapeState es = escape_state();
  78   tty->print("%s %s %s [[", node_type_names[(int) nt], esc_names[(int) es], _scalar_replaceable ? "" : "NSR");
  79   for (uint i = 0; i < edge_count(); i++) {
  80     tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
  81   }
  82   tty->print("]]  ");
  83   if (_node == NULL)
  84     tty->print_cr("<null>");
  85   else
  86     _node->dump();
  87 }
  88 #endif
  89 
  90 ConnectionGraph::ConnectionGraph(Compile * C) : _processed(C->comp_arena()), _node_map(C->comp_arena()) {
  91   _collecting = true;
  92   this->_compile = C;
  93   const PointsToNode &dummy = PointsToNode();
  94   int sz = C->unique();
  95   _nodes = new(C->comp_arena()) GrowableArray<PointsToNode>(C->comp_arena(), sz, sz, dummy);
  96   _phantom_object = C->top()->_idx;
  97   PointsToNode *phn = ptnode_adr(_phantom_object);
  98   phn->_node = C->top();
  99   phn->set_node_type(PointsToNode::JavaObject);
 100   phn->set_escape_state(PointsToNode::GlobalEscape);
 101 }
 102 
 103 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
 104   PointsToNode *f = ptnode_adr(from_i);
 105   PointsToNode *t = ptnode_adr(to_i);
 106 
 107   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 108   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
 109   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
 110   f->add_edge(to_i, PointsToNode::PointsToEdge);
 111 }
 112 
 113 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
 114   PointsToNode *f = ptnode_adr(from_i);
 115   PointsToNode *t = ptnode_adr(to_i);
 116 
 117   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 118   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
 119   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
 120   // don't add a self-referential edge, this can occur during removal of
 121   // deferred edges
 122   if (from_i != to_i)
 123     f->add_edge(to_i, PointsToNode::DeferredEdge);
 124 }
 125 
 126 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
 127   const Type *adr_type = phase->type(adr);
 128   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
 129       adr->in(AddPNode::Address)->is_Proj() &&
 130       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
 131     // We are computing a raw address for a store captured by an Initialize
 132     // compute an appropriate address type. AddP cases #3 and #5 (see below).
 133     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 134     assert(offs != Type::OffsetBot ||
 135            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
 136            "offset must be a constant or it is initialization of array");
 137     return offs;
 138   }
 139   const TypePtr *t_ptr = adr_type->isa_ptr();
 140   assert(t_ptr != NULL, "must be a pointer type");
 141   return t_ptr->offset();
 142 }
 143 
 144 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
 145   PointsToNode *f = ptnode_adr(from_i);
 146   PointsToNode *t = ptnode_adr(to_i);
 147 
 148   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 149   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
 150   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
 151   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
 152   t->set_offset(offset);
 153 
 154   f->add_edge(to_i, PointsToNode::FieldEdge);
 155 }
 156 
 157 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
 158   PointsToNode *npt = ptnode_adr(ni);
 159   PointsToNode::EscapeState old_es = npt->escape_state();
 160   if (es > old_es)
 161     npt->set_escape_state(es);
 162 }
 163 
 164 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
 165                                PointsToNode::EscapeState es, bool done) {
 166   PointsToNode* ptadr = ptnode_adr(n->_idx);
 167   ptadr->_node = n;
 168   ptadr->set_node_type(nt);
 169 
 170   // inline set_escape_state(idx, es);
 171   PointsToNode::EscapeState old_es = ptadr->escape_state();
 172   if (es > old_es)
 173     ptadr->set_escape_state(es);
 174 
 175   if (done)
 176     _processed.set(n->_idx);
 177 }
 178 
 179 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n, PhaseTransform *phase) {
 180   uint idx = n->_idx;
 181   PointsToNode::EscapeState es;
 182 
 183   // If we are still collecting or there were no non-escaping allocations
 184   // we don't know the answer yet
 185   if (_collecting || !_has_allocations)
 186     return PointsToNode::UnknownEscape;
 187 
 188   // if the node was created after the escape computation, return
 189   // UnknownEscape
 190   if (idx >= (uint)_nodes->length())
 191     return PointsToNode::UnknownEscape;
 192 
 193   es = _nodes->at_grow(idx).escape_state();
 194 
 195   // if we have already computed a value, return it
 196   if (es != PointsToNode::UnknownEscape)
 197     return es;
 198 
 199   // compute max escape state of anything this node could point to
 200   VectorSet ptset(Thread::current()->resource_area());
 201   PointsTo(ptset, n, phase);
 202   for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
 203     uint pt = i.elem;
 204     PointsToNode::EscapeState pes = _nodes->adr_at(pt)->escape_state();
 205     if (pes > es)
 206       es = pes;
 207   }
 208   // cache the computed escape state
 209   assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
 210   _nodes->adr_at(idx)->set_escape_state(es);
 211   return es;
 212 }
 213 
 214 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n, PhaseTransform *phase) {
 215   VectorSet visited(Thread::current()->resource_area());
 216   GrowableArray<uint>  worklist;
 217 
 218   n = n->uncast();
 219   PointsToNode  npt = _nodes->at_grow(n->_idx);
 220 
 221   // If we have a JavaObject, return just that object
 222   if (npt.node_type() == PointsToNode::JavaObject) {
 223     ptset.set(n->_idx);
 224     return;
 225   }
 226   assert(npt._node != NULL, "unregistered node");
 227 
 228   worklist.push(n->_idx);
 229   while(worklist.length() > 0) {
 230     int ni = worklist.pop();
 231     PointsToNode pn = _nodes->at_grow(ni);
 232     if (!visited.test_set(ni)) {
 233       // ensure that all inputs of a Phi have been processed
 234       assert(!_collecting || !pn._node->is_Phi() || _processed.test(ni),"");
 235 
 236       int edges_processed = 0;
 237       for (uint e = 0; e < pn.edge_count(); e++) {
 238         uint etgt = pn.edge_target(e);
 239         PointsToNode::EdgeType et = pn.edge_type(e);
 240         if (et == PointsToNode::PointsToEdge) {
 241           ptset.set(etgt);
 242           edges_processed++;
 243         } else if (et == PointsToNode::DeferredEdge) {
 244           worklist.push(etgt);
 245           edges_processed++;
 246         } else {
 247           assert(false,"neither PointsToEdge or DeferredEdge");
 248         }
 249       }
 250       if (edges_processed == 0) {
 251         // no deferred or pointsto edges found.  Assume the value was set
 252         // outside this method.  Add the phantom object to the pointsto set.
 253         ptset.set(_phantom_object);
 254       }
 255     }
 256   }
 257 }
 258 
 259 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
 260   // This method is most expensive during ConnectionGraph construction.
 261   // Reuse vectorSet and an additional growable array for deferred edges.
 262   deferred_edges->clear();
 263   visited->Clear();
 264 
 265   uint i = 0;
 266   PointsToNode *ptn = ptnode_adr(ni);
 267 
 268   // Mark current edges as visited and move deferred edges to separate array.
 269   for (; i < ptn->edge_count(); i++) {
 270     uint t = ptn->edge_target(i);
 271 #ifdef ASSERT
 272     assert(!visited->test_set(t), "expecting no duplications");
 273 #else
 274     visited->set(t);
 275 #endif
 276     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
 277       ptn->remove_edge(t, PointsToNode::DeferredEdge);
 278       deferred_edges->append(t);
 279     }
 280   }
 281   for (int next = 0; next < deferred_edges->length(); ++next) {
 282     uint t = deferred_edges->at(next);
 283     PointsToNode *ptt = ptnode_adr(t);
 284     for (uint j = 0; j < ptt->edge_count(); j++) {
 285       uint n1 = ptt->edge_target(j);
 286       if (visited->test_set(n1))
 287         continue;
 288       switch(ptt->edge_type(j)) {
 289         case PointsToNode::PointsToEdge:
 290           add_pointsto_edge(ni, n1);
 291           if(n1 == _phantom_object) {
 292             // Special case - field set outside (globally escaping).
 293             ptn->set_escape_state(PointsToNode::GlobalEscape);
 294           }
 295           break;
 296         case PointsToNode::DeferredEdge:
 297           deferred_edges->append(n1);
 298           break;
 299         case PointsToNode::FieldEdge:
 300           assert(false, "invalid connection graph");
 301           break;
 302       }
 303     }
 304   }
 305 }
 306 
 307 
 308 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
 309 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
 310 //  a pointsto edge is added if it is a JavaObject
 311 
 312 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
 313   PointsToNode an = _nodes->at_grow(adr_i);
 314   PointsToNode to = _nodes->at_grow(to_i);
 315   bool deferred = (to.node_type() == PointsToNode::LocalVar);
 316 
 317   for (uint fe = 0; fe < an.edge_count(); fe++) {
 318     assert(an.edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
 319     int fi = an.edge_target(fe);
 320     PointsToNode pf = _nodes->at_grow(fi);
 321     int po = pf.offset();
 322     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
 323       if (deferred)
 324         add_deferred_edge(fi, to_i);
 325       else
 326         add_pointsto_edge(fi, to_i);
 327     }
 328   }
 329 }
 330 
 331 // Add a deferred  edge from node given by "from_i" to any field of adr_i
 332 // whose offset matches "offset".
 333 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
 334   PointsToNode an = _nodes->at_grow(adr_i);
 335   for (uint fe = 0; fe < an.edge_count(); fe++) {
 336     assert(an.edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
 337     int fi = an.edge_target(fe);
 338     PointsToNode pf = _nodes->at_grow(fi);
 339     int po = pf.offset();
 340     if (pf.edge_count() == 0) {
 341       // we have not seen any stores to this field, assume it was set outside this method
 342       add_pointsto_edge(fi, _phantom_object);
 343     }
 344     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
 345       add_deferred_edge(from_i, fi);
 346     }
 347   }
 348 }
 349 
 350 // Helper functions
 351 
 352 static Node* get_addp_base(Node *addp) {
 353   assert(addp->is_AddP(), "must be AddP");
 354   //
 355   // AddP cases for Base and Address inputs:
 356   // case #1. Direct object's field reference:
 357   //     Allocate
 358   //       |
 359   //     Proj #5 ( oop result )
 360   //       |
 361   //     CheckCastPP (cast to instance type)
 362   //      | |
 363   //     AddP  ( base == address )
 364   //
 365   // case #2. Indirect object's field reference:
 366   //      Phi
 367   //       |
 368   //     CastPP (cast to instance type)
 369   //      | |
 370   //     AddP  ( base == address )
 371   //
 372   // case #3. Raw object's field reference for Initialize node:
 373   //      Allocate
 374   //        |
 375   //      Proj #5 ( oop result )
 376   //  top   |
 377   //     \  |
 378   //     AddP  ( base == top )
 379   //
 380   // case #4. Array's element reference:
 381   //   {CheckCastPP | CastPP}
 382   //     |  | |
 383   //     |  AddP ( array's element offset )
 384   //     |  |
 385   //     AddP ( array's offset )
 386   //
 387   // case #5. Raw object's field reference for arraycopy stub call:
 388   //          The inline_native_clone() case when the arraycopy stub is called
 389   //          after the allocation before Initialize and CheckCastPP nodes.
 390   //      Allocate
 391   //        |
 392   //      Proj #5 ( oop result )
 393   //       | |
 394   //       AddP  ( base == address )
 395   //
 396   // case #6. Constant Pool or ThreadLocal or Raw object's field reference:
 397   //      ConP # Object from Constant Pool.
 398   //  top   |
 399   //     \  |
 400   //     AddP  ( base == top )
 401   //
 402   Node *base = addp->in(AddPNode::Base)->uncast();
 403   if (base->is_top()) { // The AddP case #3 and #6.
 404     base = addp->in(AddPNode::Address)->uncast();
 405     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
 406            base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL ||
 407            base->is_Proj() && base->in(0)->is_Allocate(), "sanity");
 408   }
 409   return base;
 410 }
 411 
 412 static Node* find_second_addp(Node* addp, Node* n) {
 413   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
 414 
 415   Node* addp2 = addp->raw_out(0);
 416   if (addp->outcnt() == 1 && addp2->is_AddP() &&
 417       addp2->in(AddPNode::Base) == n &&
 418       addp2->in(AddPNode::Address) == addp) {
 419 
 420     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
 421     //
 422     // Find array's offset to push it on worklist first and
 423     // as result process an array's element offset first (pushed second)
 424     // to avoid CastPP for the array's offset.
 425     // Otherwise the inserted CastPP (LocalVar) will point to what
 426     // the AddP (Field) points to. Which would be wrong since
 427     // the algorithm expects the CastPP has the same point as
 428     // as AddP's base CheckCastPP (LocalVar).
 429     //
 430     //    ArrayAllocation
 431     //     |
 432     //    CheckCastPP
 433     //     |
 434     //    memProj (from ArrayAllocation CheckCastPP)
 435     //     |  ||
 436     //     |  ||   Int (element index)
 437     //     |  ||    |   ConI (log(element size))
 438     //     |  ||    |   /
 439     //     |  ||   LShift
 440     //     |  ||  /
 441     //     |  AddP (array's element offset)
 442     //     |  |
 443     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
 444     //     | / /
 445     //     AddP (array's offset)
 446     //      |
 447     //     Load/Store (memory operation on array's element)
 448     //
 449     return addp2;
 450   }
 451   return NULL;
 452 }
 453 
 454 //
 455 // Adjust the type and inputs of an AddP which computes the
 456 // address of a field of an instance
 457 //
 458 void ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
 459   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
 460   assert(base_t != NULL && base_t->is_instance(), "expecting instance oopptr");
 461   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
 462   if (t == NULL) {
 463     // We are computing a raw address for a store captured by an Initialize
 464     // compute an appropriate address type.
 465     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
 466     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
 467     int offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
 468     assert(offs != Type::OffsetBot, "offset must be a constant");
 469     t = base_t->add_offset(offs)->is_oopptr();
 470   }
 471   uint inst_id =  base_t->instance_id();
 472   assert(!t->is_instance() || t->instance_id() == inst_id,
 473                              "old type must be non-instance or match new type");
 474   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
 475   // Do NOT remove the next call: ensure an new alias index is allocated
 476   // for the instance type
 477   int alias_idx = _compile->get_alias_index(tinst);
 478   igvn->set_type(addp, tinst);
 479   // record the allocation in the node map
 480   set_map(addp->_idx, get_map(base->_idx));
 481   // if the Address input is not the appropriate instance type
 482   // (due to intervening casts,) insert a cast
 483   Node *adr = addp->in(AddPNode::Address);
 484   const TypeOopPtr  *atype = igvn->type(adr)->isa_oopptr();
 485   if (atype != NULL && atype->instance_id() != inst_id) {
 486     assert(!atype->is_instance(), "no conflicting instances");
 487     const TypeOopPtr *new_atype = base_t->add_offset(atype->offset())->isa_oopptr();
 488     Node *acast = new (_compile, 2) CastPPNode(adr, new_atype);
 489     acast->set_req(0, adr->in(0));
 490     igvn->set_type(acast, new_atype);
 491     record_for_optimizer(acast);
 492     Node *bcast = acast;
 493     Node *abase = addp->in(AddPNode::Base);
 494     if (abase != adr) {
 495       bcast = new (_compile, 2) CastPPNode(abase, base_t);
 496       bcast->set_req(0, abase->in(0));
 497       igvn->set_type(bcast, base_t);
 498       record_for_optimizer(bcast);
 499     }
 500     igvn->hash_delete(addp);
 501     addp->set_req(AddPNode::Base, bcast);
 502     addp->set_req(AddPNode::Address, acast);
 503     igvn->hash_insert(addp);
 504   }
 505   // Put on IGVN worklist since at least addp's type was changed above.
 506   record_for_optimizer(addp);
 507 }
 508 
 509 //
 510 // Create a new version of orig_phi if necessary. Returns either the newly
 511 // created phi or an existing phi.  Sets create_new to indicate wheter  a new
 512 // phi was created.  Cache the last newly created phi in the node map.
 513 //
 514 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
 515   Compile *C = _compile;
 516   new_created = false;
 517   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
 518   // nothing to do if orig_phi is bottom memory or matches alias_idx
 519   if (phi_alias_idx == alias_idx) {
 520     return orig_phi;
 521   }
 522   // have we already created a Phi for this alias index?
 523   PhiNode *result = get_map_phi(orig_phi->_idx);
 524   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
 525     return result;
 526   }
 527   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
 528     if (C->do_escape_analysis() == true && !C->failing()) {
 529       // Retry compilation without escape analysis.
 530       // If this is the first failure, the sentinel string will "stick"
 531       // to the Compile object, and the C2Compiler will see it and retry.
 532       C->record_failure(C2Compiler::retry_no_escape_analysis());
 533     }
 534     return NULL;
 535   }
 536   orig_phi_worklist.append_if_missing(orig_phi);
 537   const TypePtr *atype = C->get_adr_type(alias_idx);
 538   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
 539   set_map_phi(orig_phi->_idx, result);
 540   igvn->set_type(result, result->bottom_type());
 541   record_for_optimizer(result);
 542   new_created = true;
 543   return result;
 544 }
 545 
 546 //
 547 // Return a new version  of Memory Phi "orig_phi" with the inputs having the
 548 // specified alias index.
 549 //
 550 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
 551 
 552   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
 553   Compile *C = _compile;
 554   bool new_phi_created;
 555   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
 556   if (!new_phi_created) {
 557     return result;
 558   }
 559 
 560   GrowableArray<PhiNode *>  phi_list;
 561   GrowableArray<uint>  cur_input;
 562 
 563   PhiNode *phi = orig_phi;
 564   uint idx = 1;
 565   bool finished = false;
 566   while(!finished) {
 567     while (idx < phi->req()) {
 568       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
 569       if (mem != NULL && mem->is_Phi()) {
 570         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
 571         if (new_phi_created) {
 572           // found an phi for which we created a new split, push current one on worklist and begin
 573           // processing new one
 574           phi_list.push(phi);
 575           cur_input.push(idx);
 576           phi = mem->as_Phi();
 577           result = newphi;
 578           idx = 1;
 579           continue;
 580         } else {
 581           mem = newphi;
 582         }
 583       }
 584       if (C->failing()) {
 585         return NULL;
 586       }
 587       result->set_req(idx++, mem);
 588     }
 589 #ifdef ASSERT
 590     // verify that the new Phi has an input for each input of the original
 591     assert( phi->req() == result->req(), "must have same number of inputs.");
 592     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
 593 #endif
 594     // Check if all new phi's inputs have specified alias index.
 595     // Otherwise use old phi.
 596     for (uint i = 1; i < phi->req(); i++) {
 597       Node* in = result->in(i);
 598       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
 599     }
 600     // we have finished processing a Phi, see if there are any more to do
 601     finished = (phi_list.length() == 0 );
 602     if (!finished) {
 603       phi = phi_list.pop();
 604       idx = cur_input.pop();
 605       PhiNode *prev_result = get_map_phi(phi->_idx);
 606       prev_result->set_req(idx++, result);
 607       result = prev_result;
 608     }
 609   }
 610   return result;
 611 }
 612 
 613 
 614 //
 615 // The next methods are derived from methods in MemNode.
 616 //
 617 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *tinst) {
 618   Node *mem = mmem;
 619   // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally
 620   // means an array I have not precisely typed yet.  Do not do any
 621   // alias stuff with it any time soon.
 622   if( tinst->base() != Type::AnyPtr &&
 623       !(tinst->klass()->is_java_lang_Object() &&
 624         tinst->offset() == Type::OffsetBot) ) {
 625     mem = mmem->memory_at(alias_idx);
 626     // Update input if it is progress over what we have now
 627   }
 628   return mem;
 629 }
 630 
 631 //
 632 // Search memory chain of "mem" to find a MemNode whose address
 633 // is the specified alias index.
 634 //
 635 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
 636   if (orig_mem == NULL)
 637     return orig_mem;
 638   Compile* C = phase->C;
 639   const TypeOopPtr *tinst = C->get_adr_type(alias_idx)->isa_oopptr();
 640   bool is_instance = (tinst != NULL) && tinst->is_instance();
 641   Node *prev = NULL;
 642   Node *result = orig_mem;
 643   while (prev != result) {
 644     prev = result;
 645     if (result->is_Mem()) {
 646       MemNode *mem = result->as_Mem();
 647       const Type *at = phase->type(mem->in(MemNode::Address));
 648       if (at != Type::TOP) {
 649         assert (at->isa_ptr() != NULL, "pointer type required.");
 650         int idx = C->get_alias_index(at->is_ptr());
 651         if (idx == alias_idx)
 652           break;
 653       }
 654       result = mem->in(MemNode::Memory);
 655     }
 656     if (!is_instance)
 657       continue;  // don't search further for non-instance types
 658     // skip over a call which does not affect this memory slice
 659     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
 660       Node *proj_in = result->in(0);
 661       if (proj_in->is_Call()) {
 662         CallNode *call = proj_in->as_Call();
 663         if (!call->may_modify(tinst, phase)) {
 664           result = call->in(TypeFunc::Memory);
 665         }
 666       } else if (proj_in->is_Initialize()) {
 667         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
 668         // Stop if this is the initialization for the object instance which
 669         // which contains this memory slice, otherwise skip over it.
 670         if (alloc == NULL || alloc->_idx != tinst->instance_id()) {
 671           result = proj_in->in(TypeFunc::Memory);
 672         }
 673       } else if (proj_in->is_MemBar()) {
 674         result = proj_in->in(TypeFunc::Memory);
 675       }
 676     } else if (result->is_MergeMem()) {
 677       MergeMemNode *mmem = result->as_MergeMem();
 678       result = step_through_mergemem(mmem, alias_idx, tinst);
 679       if (result == mmem->base_memory()) {
 680         // Didn't find instance memory, search through general slice recursively.
 681         result = mmem->memory_at(C->get_general_index(alias_idx));
 682         result = find_inst_mem(result, alias_idx, orig_phis, phase);
 683         if (C->failing()) {
 684           return NULL;
 685         }
 686         mmem->set_memory_at(alias_idx, result);
 687       }
 688     } else if (result->is_Phi() &&
 689                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
 690       Node *un = result->as_Phi()->unique_input(phase);
 691       if (un != NULL) {
 692         result = un;
 693       } else {
 694         break;
 695       }
 696     }
 697   }
 698   if (is_instance && result->is_Phi()) {
 699     PhiNode *mphi = result->as_Phi();
 700     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
 701     const TypePtr *t = mphi->adr_type();
 702     if (C->get_alias_index(t) != alias_idx) {
 703       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
 704     }
 705   }
 706   // the result is either MemNode, PhiNode, InitializeNode.
 707   return result;
 708 }
 709 
 710 
 711 //
 712 //  Convert the types of unescaped object to instance types where possible,
 713 //  propagate the new type information through the graph, and update memory
 714 //  edges and MergeMem inputs to reflect the new type.
 715 //
 716 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
 717 //  The processing is done in 4 phases:
 718 //
 719 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
 720 //            types for the CheckCastPP for allocations where possible.
 721 //            Propagate the the new types through users as follows:
 722 //               casts and Phi:  push users on alloc_worklist
 723 //               AddP:  cast Base and Address inputs to the instance type
 724 //                      push any AddP users on alloc_worklist and push any memnode
 725 //                      users onto memnode_worklist.
 726 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
 727 //            search the Memory chain for a store with the appropriate type
 728 //            address type.  If a Phi is found, create a new version with
 729 //            the approriate memory slices from each of the Phi inputs.
 730 //            For stores, process the users as follows:
 731 //               MemNode:  push on memnode_worklist
 732 //               MergeMem: push on mergemem_worklist
 733 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
 734 //            moving the first node encountered of each  instance type to the
 735 //            the input corresponding to its alias index.
 736 //            appropriate memory slice.
 737 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
 738 //
 739 // In the following example, the CheckCastPP nodes are the cast of allocation
 740 // results and the allocation of node 29 is unescaped and eligible to be an
 741 // instance type.
 742 //
 743 // We start with:
 744 //
 745 //     7 Parm #memory
 746 //    10  ConI  "12"
 747 //    19  CheckCastPP   "Foo"
 748 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 749 //    29  CheckCastPP   "Foo"
 750 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
 751 //
 752 //    40  StoreP  25   7  20   ... alias_index=4
 753 //    50  StoreP  35  40  30   ... alias_index=4
 754 //    60  StoreP  45  50  20   ... alias_index=4
 755 //    70  LoadP    _  60  30   ... alias_index=4
 756 //    80  Phi     75  50  60   Memory alias_index=4
 757 //    90  LoadP    _  80  30   ... alias_index=4
 758 //   100  LoadP    _  80  20   ... alias_index=4
 759 //
 760 //
 761 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
 762 // and creating a new alias index for node 30.  This gives:
 763 //
 764 //     7 Parm #memory
 765 //    10  ConI  "12"
 766 //    19  CheckCastPP   "Foo"
 767 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 768 //    29  CheckCastPP   "Foo"  iid=24
 769 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
 770 //
 771 //    40  StoreP  25   7  20   ... alias_index=4
 772 //    50  StoreP  35  40  30   ... alias_index=6
 773 //    60  StoreP  45  50  20   ... alias_index=4
 774 //    70  LoadP    _  60  30   ... alias_index=6
 775 //    80  Phi     75  50  60   Memory alias_index=4
 776 //    90  LoadP    _  80  30   ... alias_index=6
 777 //   100  LoadP    _  80  20   ... alias_index=4
 778 //
 779 // In phase 2, new memory inputs are computed for the loads and stores,
 780 // And a new version of the phi is created.  In phase 4, the inputs to
 781 // node 80 are updated and then the memory nodes are updated with the
 782 // values computed in phase 2.  This results in:
 783 //
 784 //     7 Parm #memory
 785 //    10  ConI  "12"
 786 //    19  CheckCastPP   "Foo"
 787 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 788 //    29  CheckCastPP   "Foo"  iid=24
 789 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
 790 //
 791 //    40  StoreP  25  7   20   ... alias_index=4
 792 //    50  StoreP  35  7   30   ... alias_index=6
 793 //    60  StoreP  45  40  20   ... alias_index=4
 794 //    70  LoadP    _  50  30   ... alias_index=6
 795 //    80  Phi     75  40  60   Memory alias_index=4
 796 //   120  Phi     75  50  50   Memory alias_index=6
 797 //    90  LoadP    _ 120  30   ... alias_index=6
 798 //   100  LoadP    _  80  20   ... alias_index=4
 799 //
 800 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
 801   GrowableArray<Node *>  memnode_worklist;
 802   GrowableArray<Node *>  mergemem_worklist;
 803   GrowableArray<PhiNode *>  orig_phis;
 804   PhaseGVN  *igvn = _compile->initial_gvn();
 805   uint new_index_start = (uint) _compile->num_alias_types();
 806   VectorSet visited(Thread::current()->resource_area());
 807   VectorSet ptset(Thread::current()->resource_area());
 808 
 809 
 810   //  Phase 1:  Process possible allocations from alloc_worklist.
 811   //  Create instance types for the CheckCastPP for allocations where possible.
 812   while (alloc_worklist.length() != 0) {
 813     Node *n = alloc_worklist.pop();
 814     uint ni = n->_idx;
 815     const TypeOopPtr* tinst = NULL;
 816     if (n->is_Call()) {
 817       CallNode *alloc = n->as_Call();
 818       // copy escape information to call node
 819       PointsToNode* ptn = _nodes->adr_at(alloc->_idx);
 820       PointsToNode::EscapeState es = escape_state(alloc, igvn);
 821       // We have an allocation or call which returns a Java object,
 822       // see if it is unescaped.
 823       if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
 824         continue;
 825       if (alloc->is_Allocate()) {
 826         // Set the scalar_replaceable flag before the next check.
 827         alloc->as_Allocate()->_is_scalar_replaceable = true;
 828       }
 829       // find CheckCastPP of call return value
 830       n = alloc->result_cast();
 831       if (n == NULL ||          // No uses accept Initialize or
 832           !n->is_CheckCastPP()) // not unique CheckCastPP.
 833         continue;
 834       // The inline code for Object.clone() casts the allocation result to
 835       // java.lang.Object and then to the the actual type of the allocated
 836       // object. Detect this case and use the second cast.
 837       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
 838           && igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT) {
 839         Node *cast2 = NULL;
 840         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 841           Node *use = n->fast_out(i);
 842           if (use->is_CheckCastPP()) {
 843             cast2 = use;
 844             break;
 845           }
 846         }
 847         if (cast2 != NULL) {
 848           n = cast2;
 849         } else {
 850           continue;
 851         }
 852       }
 853       set_escape_state(n->_idx, es);
 854       // in order for an object to be stackallocatable, it must be:
 855       //   - a direct allocation (not a call returning an object)
 856       //   - non-escaping
 857       //   - eligible to be a unique type
 858       //   - not determined to be ineligible by escape analysis
 859       set_map(alloc->_idx, n);
 860       set_map(n->_idx, alloc);
 861       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
 862       if (t == NULL)
 863         continue;  // not a TypeInstPtr
 864       tinst = t->cast_to_instance(ni);
 865       igvn->hash_delete(n);
 866       igvn->set_type(n,  tinst);
 867       n->raise_bottom_type(tinst);
 868       igvn->hash_insert(n);
 869       record_for_optimizer(n);
 870       if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
 871           (t->isa_instptr() || t->isa_aryptr())) {
 872         // An allocation may have an Initialize which has raw stores. Scan
 873         // the users of the raw allocation result and push AddP users
 874         // on alloc_worklist.
 875         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
 876         assert (raw_result != NULL, "must have an allocation result");
 877         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
 878           Node *use = raw_result->fast_out(i);
 879           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
 880             Node* addp2 = find_second_addp(use, raw_result);
 881             if (addp2 != NULL) {
 882               assert(alloc->is_AllocateArray(),"array allocation was expected");
 883               alloc_worklist.append_if_missing(addp2);
 884             }
 885             alloc_worklist.append_if_missing(use);
 886           } else if (use->is_Initialize()) {
 887             memnode_worklist.append_if_missing(use);
 888           }
 889         }
 890       }
 891     } else if (n->is_AddP()) {
 892       ptset.Clear();
 893       PointsTo(ptset, get_addp_base(n), igvn);
 894       assert(ptset.Size() == 1, "AddP address is unique");
 895       uint elem = ptset.getelem(); // Allocation node's index
 896       if (elem == _phantom_object)
 897         continue; // Assume the value was set outside this method.
 898       Node *base = get_map(elem);  // CheckCastPP node
 899       split_AddP(n, base, igvn);
 900       tinst = igvn->type(base)->isa_oopptr();
 901     } else if (n->is_Phi() ||
 902                n->is_CheckCastPP() ||
 903                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
 904       if (visited.test_set(n->_idx)) {
 905         assert(n->is_Phi(), "loops only through Phi's");
 906         continue;  // already processed
 907       }
 908       ptset.Clear();
 909       PointsTo(ptset, n, igvn);
 910       if (ptset.Size() == 1) {
 911         uint elem = ptset.getelem(); // Allocation node's index
 912         if (elem == _phantom_object)
 913           continue; // Assume the value was set outside this method.
 914         Node *val = get_map(elem);   // CheckCastPP node
 915         TypeNode *tn = n->as_Type();
 916         tinst = igvn->type(val)->isa_oopptr();
 917         assert(tinst != NULL && tinst->is_instance() &&
 918                tinst->instance_id() == elem , "instance type expected.");
 919         const TypeOopPtr *tn_t = igvn->type(tn)->isa_oopptr();
 920 
 921         if (tn_t != NULL &&
 922  tinst->cast_to_instance(TypeOopPtr::UNKNOWN_INSTANCE)->higher_equal(tn_t)) {
 923           igvn->hash_delete(tn);
 924           igvn->set_type(tn, tinst);
 925           tn->set_type(tinst);
 926           igvn->hash_insert(tn);
 927           record_for_optimizer(n);
 928         }
 929       }
 930     } else {
 931       continue;
 932     }
 933     // push users on appropriate worklist
 934     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 935       Node *use = n->fast_out(i);
 936       if(use->is_Mem() && use->in(MemNode::Address) == n) {
 937         memnode_worklist.append_if_missing(use);
 938       } else if (use->is_Initialize()) {
 939         memnode_worklist.append_if_missing(use);
 940       } else if (use->is_MergeMem()) {
 941         mergemem_worklist.append_if_missing(use);
 942       } else if (use->is_Call() && tinst != NULL) {
 943         // Look for MergeMem nodes for calls which reference unique allocation
 944         // (through CheckCastPP nodes) even for debug info.
 945         Node* m = use->in(TypeFunc::Memory);
 946         uint iid = tinst->instance_id();
 947         while (m->is_Proj() && m->in(0)->is_Call() &&
 948                m->in(0) != use && !m->in(0)->_idx != iid) {
 949           m = m->in(0)->in(TypeFunc::Memory);
 950         }
 951         if (m->is_MergeMem()) {
 952           mergemem_worklist.append_if_missing(m);
 953         }
 954       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
 955         Node* addp2 = find_second_addp(use, n);
 956         if (addp2 != NULL) {
 957           alloc_worklist.append_if_missing(addp2);
 958         }
 959         alloc_worklist.append_if_missing(use);
 960       } else if (use->is_Phi() ||
 961                  use->is_CheckCastPP() ||
 962                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
 963         alloc_worklist.append_if_missing(use);
 964       }
 965     }
 966 
 967   }
 968   // New alias types were created in split_AddP().
 969   uint new_index_end = (uint) _compile->num_alias_types();
 970 
 971   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
 972   //            compute new values for Memory inputs  (the Memory inputs are not
 973   //            actually updated until phase 4.)
 974   if (memnode_worklist.length() == 0)
 975     return;  // nothing to do
 976 
 977   while (memnode_worklist.length() != 0) {
 978     Node *n = memnode_worklist.pop();
 979     if (visited.test_set(n->_idx))
 980       continue;
 981     if (n->is_Phi()) {
 982       assert(n->as_Phi()->adr_type() != TypePtr::BOTTOM, "narrow memory slice required");
 983       // we don't need to do anything, but the users must be pushed if we haven't processed
 984       // this Phi before
 985     } else if (n->is_Initialize()) {
 986       // we don't need to do anything, but the users of the memory projection must be pushed
 987       n = n->as_Initialize()->proj_out(TypeFunc::Memory);
 988       if (n == NULL)
 989         continue;
 990     } else {
 991       assert(n->is_Mem(), "memory node required.");
 992       Node *addr = n->in(MemNode::Address);
 993       assert(addr->is_AddP(), "AddP required");
 994       const Type *addr_t = igvn->type(addr);
 995       if (addr_t == Type::TOP)
 996         continue;
 997       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
 998       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
 999       assert ((uint)alias_idx < new_index_end, "wrong alias index");
1000       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1001       if (_compile->failing()) {
1002         return;
1003       }
1004       if (mem != n->in(MemNode::Memory)) {
1005         set_map(n->_idx, mem);
1006         _nodes->adr_at(n->_idx)->_node = n;
1007       }
1008       if (n->is_Load()) {
1009         continue;  // don't push users
1010       } else if (n->is_LoadStore()) {
1011         // get the memory projection
1012         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1013           Node *use = n->fast_out(i);
1014           if (use->Opcode() == Op_SCMemProj) {
1015             n = use;
1016             break;
1017           }
1018         }
1019         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1020       }
1021     }
1022     // push user on appropriate worklist
1023     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1024       Node *use = n->fast_out(i);
1025       if (use->is_Phi()) {
1026         memnode_worklist.append_if_missing(use);
1027       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1028         memnode_worklist.append_if_missing(use);
1029       } else if (use->is_Initialize()) {
1030         memnode_worklist.append_if_missing(use);
1031       } else if (use->is_MergeMem()) {
1032         mergemem_worklist.append_if_missing(use);
1033       }
1034     }
1035   }
1036 
1037   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
1038   //            Walk each memory moving the first node encountered of each
1039   //            instance type to the the input corresponding to its alias index.
1040   while (mergemem_worklist.length() != 0) {
1041     Node *n = mergemem_worklist.pop();
1042     assert(n->is_MergeMem(), "MergeMem node required.");
1043     if (visited.test_set(n->_idx))
1044       continue;
1045     MergeMemNode *nmm = n->as_MergeMem();
1046     // Note: we don't want to use MergeMemStream here because we only want to
1047     //  scan inputs which exist at the start, not ones we add during processing.
1048     uint nslices = nmm->req();
1049     igvn->hash_delete(nmm);
1050     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1051       Node* mem = nmm->in(i);
1052       Node* cur = NULL;
1053       if (mem == NULL || mem->is_top())
1054         continue;
1055       while (mem->is_Mem()) {
1056         const Type *at = igvn->type(mem->in(MemNode::Address));
1057         if (at != Type::TOP) {
1058           assert (at->isa_ptr() != NULL, "pointer type required.");
1059           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1060           if (idx == i) {
1061             if (cur == NULL)
1062               cur = mem;
1063           } else {
1064             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1065               nmm->set_memory_at(idx, mem);
1066             }
1067           }
1068         }
1069         mem = mem->in(MemNode::Memory);
1070       }
1071       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1072       // Find any instance of the current type if we haven't encountered
1073       // a value of the instance along the chain.
1074       for (uint ni = new_index_start; ni < new_index_end; ni++) {
1075         if((uint)_compile->get_general_index(ni) == i) {
1076           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1077           if (nmm->is_empty_memory(m)) {
1078             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1079             if (_compile->failing()) {
1080               return;
1081             }
1082             nmm->set_memory_at(ni, result);
1083           }
1084         }
1085       }
1086     }
1087     // Find the rest of instances values
1088     for (uint ni = new_index_start; ni < new_index_end; ni++) {
1089       const TypeOopPtr *tinst = igvn->C->get_adr_type(ni)->isa_oopptr();
1090       Node* result = step_through_mergemem(nmm, ni, tinst);
1091       if (result == nmm->base_memory()) {
1092         // Didn't find instance memory, search through general slice recursively.
1093         result = nmm->memory_at(igvn->C->get_general_index(ni));
1094         result = find_inst_mem(result, ni, orig_phis, igvn);
1095         if (_compile->failing()) {
1096           return;
1097         }
1098         nmm->set_memory_at(ni, result);
1099       }
1100     }
1101     igvn->hash_insert(nmm);
1102     record_for_optimizer(nmm);
1103 
1104     // Propagate new memory slices to following MergeMem nodes.
1105     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1106       Node *use = n->fast_out(i);
1107       if (use->is_Call()) {
1108         CallNode* in = use->as_Call();
1109         if (in->proj_out(TypeFunc::Memory) != NULL) {
1110           Node* m = in->proj_out(TypeFunc::Memory);
1111           for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
1112             Node* mm = m->fast_out(j);
1113             if (mm->is_MergeMem()) {
1114               mergemem_worklist.append_if_missing(mm);
1115             }
1116           }
1117         }
1118         if (use->is_Allocate()) {
1119           use = use->as_Allocate()->initialization();
1120           if (use == NULL) {
1121             continue;
1122           }
1123         }
1124       }
1125       if (use->is_Initialize()) {
1126         InitializeNode* in = use->as_Initialize();
1127         if (in->proj_out(TypeFunc::Memory) != NULL) {
1128           Node* m = in->proj_out(TypeFunc::Memory);
1129           for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
1130             Node* mm = m->fast_out(j);
1131             if (mm->is_MergeMem()) {
1132               mergemem_worklist.append_if_missing(mm);
1133             }
1134           }
1135         }
1136       }
1137     }
1138   }
1139 
1140   //  Phase 4:  Update the inputs of non-instance memory Phis and
1141   //            the Memory input of memnodes
1142   // First update the inputs of any non-instance Phi's from
1143   // which we split out an instance Phi.  Note we don't have
1144   // to recursively process Phi's encounted on the input memory
1145   // chains as is done in split_memory_phi() since they  will
1146   // also be processed here.
1147   while (orig_phis.length() != 0) {
1148     PhiNode *phi = orig_phis.pop();
1149     int alias_idx = _compile->get_alias_index(phi->adr_type());
1150     igvn->hash_delete(phi);
1151     for (uint i = 1; i < phi->req(); i++) {
1152       Node *mem = phi->in(i);
1153       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1154       if (_compile->failing()) {
1155         return;
1156       }
1157       if (mem != new_mem) {
1158         phi->set_req(i, new_mem);
1159       }
1160     }
1161     igvn->hash_insert(phi);
1162     record_for_optimizer(phi);
1163   }
1164 
1165   // Update the memory inputs of MemNodes with the value we computed
1166   // in Phase 2.
1167   for (int i = 0; i < _nodes->length(); i++) {
1168     Node *nmem = get_map(i);
1169     if (nmem != NULL) {
1170       Node *n = _nodes->adr_at(i)->_node;
1171       if (n != NULL && n->is_Mem()) {
1172         igvn->hash_delete(n);
1173         n->set_req(MemNode::Memory, nmem);
1174         igvn->hash_insert(n);
1175         record_for_optimizer(n);
1176       }
1177     }
1178   }
1179 }
1180 
1181 void ConnectionGraph::compute_escape() {
1182 
1183   // 1. Populate Connection Graph with Ideal nodes.
1184 
1185   Unique_Node_List worklist_init;
1186   worklist_init.map(_compile->unique(), NULL);  // preallocate space
1187 
1188   // Initialize worklist
1189   if (_compile->root() != NULL) {
1190     worklist_init.push(_compile->root());
1191   }
1192 
1193   GrowableArray<int> cg_worklist;
1194   PhaseGVN* igvn = _compile->initial_gvn();
1195   bool has_allocations = false;
1196 
1197   // Push all useful nodes onto CG list and set their type.
1198   for( uint next = 0; next < worklist_init.size(); ++next ) {
1199     Node* n = worklist_init.at(next);
1200     record_for_escape_analysis(n, igvn);
1201     if (n->is_Call() &&
1202         _nodes->adr_at(n->_idx)->node_type() == PointsToNode::JavaObject) {
1203       has_allocations = true;
1204     }
1205     if(n->is_AddP())
1206       cg_worklist.append(n->_idx);
1207     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1208       Node* m = n->fast_out(i);   // Get user
1209       worklist_init.push(m);
1210     }
1211   }
1212 
1213   if (has_allocations) {
1214     _has_allocations = true;
1215   } else {
1216     _has_allocations = false;
1217     _collecting = false;
1218     return; // Nothing to do.
1219   }
1220 
1221   // 2. First pass to create simple CG edges (doesn't require to walk CG).
1222   for( uint next = 0; next < _delayed_worklist.size(); ++next ) {
1223     Node* n = _delayed_worklist.at(next);
1224     build_connection_graph(n, igvn);
1225   }
1226 
1227   // 3. Pass to create fields edges (Allocate -F-> AddP).
1228   for( int next = 0; next < cg_worklist.length(); ++next ) {
1229     int ni = cg_worklist.at(next);
1230     build_connection_graph(_nodes->adr_at(ni)->_node, igvn);
1231   }
1232 
1233   cg_worklist.clear();
1234   cg_worklist.append(_phantom_object);
1235 
1236   // 4. Build Connection Graph which need
1237   //    to walk the connection graph.
1238   for (uint ni = 0; ni < (uint)_nodes->length(); ni++) {
1239     PointsToNode* ptn = _nodes->adr_at(ni);
1240     Node *n = ptn->_node;
1241     if (n != NULL) { // Call, AddP, LoadP, StoreP
1242       build_connection_graph(n, igvn);
1243       if (ptn->node_type() != PointsToNode::UnknownType)
1244         cg_worklist.append(n->_idx); // Collect CG nodes
1245     }
1246   }
1247 
1248   VectorSet ptset(Thread::current()->resource_area());
1249   GrowableArray<Node*> alloc_worklist;
1250   GrowableArray<int>   worklist;
1251   GrowableArray<uint>  deferred_edges;
1252   VectorSet visited(Thread::current()->resource_area());
1253 
1254   // remove deferred edges from the graph and collect
1255   // information we will need for type splitting
1256   for( int next = 0; next < cg_worklist.length(); ++next ) {
1257     int ni = cg_worklist.at(next);
1258     PointsToNode* ptn = _nodes->adr_at(ni);
1259     PointsToNode::NodeType nt = ptn->node_type();
1260     Node *n = ptn->_node;
1261     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1262       remove_deferred(ni, &deferred_edges, &visited);
1263       if (n->is_AddP()) {
1264         // If this AddP computes an address which may point to more that one
1265         // object, nothing the address points to can be scalar replaceable.
1266         Node *base = get_addp_base(n);
1267         ptset.Clear();
1268         PointsTo(ptset, base, igvn);
1269         if (ptset.Size() > 1) {
1270           for( VectorSetI j(&ptset); j.test(); ++j ) {
1271             uint pt = j.elem;
1272             ptnode_adr(pt)->_scalar_replaceable = false;
1273           }
1274         }
1275       }
1276     } else if (nt == PointsToNode::JavaObject && n->is_Call()) {
1277       // Push call on alloc_worlist (alocations are calls)
1278       // for processing by split_unique_types().
1279       alloc_worklist.append(n);
1280     }
1281   }
1282 
1283   // push all GlobalEscape nodes on the worklist
1284   for( int next = 0; next < cg_worklist.length(); ++next ) {
1285     int nk = cg_worklist.at(next);
1286     if (_nodes->adr_at(nk)->escape_state() == PointsToNode::GlobalEscape)
1287       worklist.append(nk);
1288   }
1289   // mark all node reachable from GlobalEscape nodes
1290   while(worklist.length() > 0) {
1291     PointsToNode n = _nodes->at(worklist.pop());
1292     for (uint ei = 0; ei < n.edge_count(); ei++) {
1293       uint npi = n.edge_target(ei);
1294       PointsToNode *np = ptnode_adr(npi);
1295       if (np->escape_state() < PointsToNode::GlobalEscape) {
1296         np->set_escape_state(PointsToNode::GlobalEscape);
1297         worklist.append_if_missing(npi);
1298       }
1299     }
1300   }
1301 
1302   // push all ArgEscape nodes on the worklist
1303   for( int next = 0; next < cg_worklist.length(); ++next ) {
1304     int nk = cg_worklist.at(next);
1305     if (_nodes->adr_at(nk)->escape_state() == PointsToNode::ArgEscape)
1306       worklist.push(nk);
1307   }
1308   // mark all node reachable from ArgEscape nodes
1309   while(worklist.length() > 0) {
1310     PointsToNode n = _nodes->at(worklist.pop());
1311     for (uint ei = 0; ei < n.edge_count(); ei++) {
1312       uint npi = n.edge_target(ei);
1313       PointsToNode *np = ptnode_adr(npi);
1314       if (np->escape_state() < PointsToNode::ArgEscape) {
1315         np->set_escape_state(PointsToNode::ArgEscape);
1316         worklist.append_if_missing(npi);
1317       }
1318     }
1319   }
1320 
1321   // push all NoEscape nodes on the worklist
1322   for( int next = 0; next < cg_worklist.length(); ++next ) {
1323     int nk = cg_worklist.at(next);
1324     if (_nodes->adr_at(nk)->escape_state() == PointsToNode::NoEscape)
1325       worklist.push(nk);
1326   }
1327   // mark all node reachable from NoEscape nodes
1328   while(worklist.length() > 0) {
1329     PointsToNode n = _nodes->at(worklist.pop());
1330     for (uint ei = 0; ei < n.edge_count(); ei++) {
1331       uint npi = n.edge_target(ei);
1332       PointsToNode *np = ptnode_adr(npi);
1333       if (np->escape_state() < PointsToNode::NoEscape) {
1334         np->set_escape_state(PointsToNode::NoEscape);
1335         worklist.append_if_missing(npi);
1336       }
1337     }
1338   }
1339 
1340   _collecting = false;
1341 
1342   has_allocations = false; // Are there scalar replaceable allocations?
1343 
1344   for( int next = 0; next < alloc_worklist.length(); ++next ) {
1345     Node* n = alloc_worklist.at(next);
1346     uint ni = n->_idx;
1347     PointsToNode* ptn = _nodes->adr_at(ni);
1348     PointsToNode::EscapeState es = ptn->escape_state();
1349     if (ptn->escape_state() == PointsToNode::NoEscape &&
1350         ptn->_scalar_replaceable) {
1351       has_allocations = true;
1352       break;
1353     }
1354   }
1355   if (!has_allocations) {
1356     return; // Nothing to do.
1357   }
1358 
1359   if(_compile->AliasLevel() >= 3 && EliminateAllocations) {
1360     // Now use the escape information to create unique types for
1361     // unescaped objects
1362     split_unique_types(alloc_worklist);
1363     if (_compile->failing())  return;
1364 
1365     // Clean up after split unique types.
1366     ResourceMark rm;
1367     PhaseRemoveUseless pru(_compile->initial_gvn(), _compile->for_igvn());
1368 
1369 #ifdef ASSERT
1370   } else if (PrintEscapeAnalysis || PrintEliminateAllocations) {
1371     tty->print("=== No allocations eliminated for ");
1372     C()->method()->print_short_name();
1373     if(!EliminateAllocations) {
1374       tty->print(" since EliminateAllocations is off ===");
1375     } else if(_compile->AliasLevel() < 3) {
1376       tty->print(" since AliasLevel < 3 ===");
1377     }
1378     tty->cr();
1379 #endif
1380   }
1381 }
1382 
1383 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1384 
1385     switch (call->Opcode()) {
1386 #ifdef ASSERT
1387     case Op_Allocate:
1388     case Op_AllocateArray:
1389     case Op_Lock:
1390     case Op_Unlock:
1391       assert(false, "should be done already");
1392       break;
1393 #endif
1394     case Op_CallLeafNoFP:
1395     {
1396       // Stub calls, objects do not escape but they are not scale replaceable.
1397       // Adjust escape state for outgoing arguments.
1398       const TypeTuple * d = call->tf()->domain();
1399       VectorSet ptset(Thread::current()->resource_area());
1400       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1401         const Type* at = d->field_at(i);
1402         Node *arg = call->in(i)->uncast();
1403         const Type *aat = phase->type(arg);
1404         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr()) {
1405           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1406                  aat->isa_ptr() != NULL, "expecting an Ptr");
1407           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1408           if (arg->is_AddP()) {
1409             //
1410             // The inline_native_clone() case when the arraycopy stub is called
1411             // after the allocation before Initialize and CheckCastPP nodes.
1412             //
1413             // Set AddP's base (Allocate) as not scalar replaceable since
1414             // pointer to the base (with offset) is passed as argument.
1415             //
1416             arg = get_addp_base(arg);
1417           }
1418           ptset.Clear();
1419           PointsTo(ptset, arg, phase);
1420           for( VectorSetI j(&ptset); j.test(); ++j ) {
1421             uint pt = j.elem;
1422             set_escape_state(pt, PointsToNode::ArgEscape);
1423           }
1424         }
1425       }
1426       break;
1427     }
1428 
1429     case Op_CallStaticJava:
1430     // For a static call, we know exactly what method is being called.
1431     // Use bytecode estimator to record the call's escape affects
1432     {
1433       ciMethod *meth = call->as_CallJava()->method();
1434       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1435       // fall-through if not a Java method or no analyzer information
1436       if (call_analyzer != NULL) {
1437         const TypeTuple * d = call->tf()->domain();
1438         VectorSet ptset(Thread::current()->resource_area());
1439         bool copy_dependencies = false;
1440         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1441           const Type* at = d->field_at(i);
1442           int k = i - TypeFunc::Parms;
1443 
1444           if (at->isa_oopptr() != NULL) {
1445             Node *arg = call->in(i)->uncast();
1446 
1447             bool global_escapes = false;
1448             bool fields_escapes = false;
1449             if (!call_analyzer->is_arg_stack(k)) {
1450               // The argument global escapes, mark everything it could point to
1451               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1452               global_escapes = true;
1453             } else {
1454               if (!call_analyzer->is_arg_local(k)) {
1455                 // The argument itself doesn't escape, but any fields might
1456                 fields_escapes = true;
1457               }
1458               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1459               copy_dependencies = true;
1460             }
1461 
1462             ptset.Clear();
1463             PointsTo(ptset, arg, phase);
1464             for( VectorSetI j(&ptset); j.test(); ++j ) {
1465               uint pt = j.elem;
1466               if (global_escapes) {
1467                 //The argument global escapes, mark everything it could point to
1468                 set_escape_state(pt, PointsToNode::GlobalEscape);
1469               } else {
1470                 if (fields_escapes) {
1471                   // The argument itself doesn't escape, but any fields might
1472                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
1473                 }
1474                 set_escape_state(pt, PointsToNode::ArgEscape);
1475               }
1476             }
1477           }
1478         }
1479         if (copy_dependencies)
1480           call_analyzer->copy_dependencies(C()->dependencies());
1481         break;
1482       }
1483     }
1484 
1485     default:
1486     // Fall-through here if not a Java method or no analyzer information
1487     // or some other type of call, assume the worst case: all arguments
1488     // globally escape.
1489     {
1490       // adjust escape state for  outgoing arguments
1491       const TypeTuple * d = call->tf()->domain();
1492       VectorSet ptset(Thread::current()->resource_area());
1493       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1494         const Type* at = d->field_at(i);
1495         if (at->isa_oopptr() != NULL) {
1496           Node *arg = call->in(i)->uncast();
1497           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1498           ptset.Clear();
1499           PointsTo(ptset, arg, phase);
1500           for( VectorSetI j(&ptset); j.test(); ++j ) {
1501             uint pt = j.elem;
1502             set_escape_state(pt, PointsToNode::GlobalEscape);
1503             PointsToNode *ptadr = ptnode_adr(pt);
1504           }
1505         }
1506       }
1507     }
1508   }
1509 }
1510 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
1511   PointsToNode *ptadr = ptnode_adr(resproj->_idx);
1512 
1513   CallNode *call = resproj->in(0)->as_Call();
1514   switch (call->Opcode()) {
1515     case Op_Allocate:
1516     {
1517       Node *k = call->in(AllocateNode::KlassNode);
1518       const TypeKlassPtr *kt;
1519       if (k->Opcode() == Op_LoadKlass) {
1520         kt = k->as_Load()->type()->isa_klassptr();
1521       } else {
1522         kt = k->as_Type()->type()->isa_klassptr();
1523       }
1524       assert(kt != NULL, "TypeKlassPtr  required.");
1525       ciKlass* cik = kt->klass();
1526       ciInstanceKlass* ciik = cik->as_instance_klass();
1527 
1528       PointsToNode *ptadr = ptnode_adr(call->_idx);
1529       PointsToNode::EscapeState es;
1530       uint edge_to;
1531       if (cik->is_subclass_of(_compile->env()->Thread_klass()) || ciik->has_finalizer()) {
1532         es = PointsToNode::GlobalEscape;
1533         edge_to = _phantom_object; // Could not be worse
1534       } else {
1535         es = PointsToNode::NoEscape;
1536         edge_to = call->_idx;
1537       }
1538       set_escape_state(call->_idx, es);
1539       add_pointsto_edge(resproj->_idx, edge_to);
1540       _processed.set(resproj->_idx);
1541       break;
1542     }
1543 
1544     case Op_AllocateArray:
1545     {
1546       PointsToNode *ptadr = ptnode_adr(call->_idx);
1547       int length = call->in(AllocateNode::ALength)->find_int_con(-1);
1548       if (length < 0 || length > EliminateAllocationArraySizeLimit) {
1549         // Not scalar replaceable if the length is not constant or too big.
1550         ptadr->_scalar_replaceable = false;
1551       }
1552       set_escape_state(call->_idx, PointsToNode::NoEscape);
1553       add_pointsto_edge(resproj->_idx, call->_idx);
1554       _processed.set(resproj->_idx);
1555       break;
1556     }
1557 
1558     case Op_CallStaticJava:
1559     // For a static call, we know exactly what method is being called.
1560     // Use bytecode estimator to record whether the call's return value escapes
1561     {
1562       bool done = true;
1563       const TypeTuple *r = call->tf()->range();
1564       const Type* ret_type = NULL;
1565 
1566       if (r->cnt() > TypeFunc::Parms)
1567         ret_type = r->field_at(TypeFunc::Parms);
1568 
1569       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
1570       //        _multianewarray functions return a TypeRawPtr.
1571       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
1572         _processed.set(resproj->_idx);
1573         break;  // doesn't return a pointer type
1574       }
1575       ciMethod *meth = call->as_CallJava()->method();
1576       const TypeTuple * d = call->tf()->domain();
1577       if (meth == NULL) {
1578         // not a Java method, assume global escape
1579         set_escape_state(call->_idx, PointsToNode::GlobalEscape);
1580         if (resproj != NULL)
1581           add_pointsto_edge(resproj->_idx, _phantom_object);
1582       } else {
1583         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
1584         VectorSet ptset(Thread::current()->resource_area());
1585         bool copy_dependencies = false;
1586 
1587         if (call_analyzer->is_return_allocated()) {
1588           // Returns a newly allocated unescaped object, simply
1589           // update dependency information.
1590           // Mark it as NoEscape so that objects referenced by
1591           // it's fields will be marked as NoEscape at least.
1592           set_escape_state(call->_idx, PointsToNode::NoEscape);
1593           if (resproj != NULL)
1594             add_pointsto_edge(resproj->_idx, call->_idx);
1595           copy_dependencies = true;
1596         } else if (call_analyzer->is_return_local() && resproj != NULL) {
1597           // determine whether any arguments are returned
1598           set_escape_state(call->_idx, PointsToNode::NoEscape);
1599           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1600             const Type* at = d->field_at(i);
1601 
1602             if (at->isa_oopptr() != NULL) {
1603               Node *arg = call->in(i)->uncast();
1604 
1605               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
1606                 PointsToNode *arg_esp = _nodes->adr_at(arg->_idx);
1607                 if (arg_esp->node_type() == PointsToNode::UnknownType)
1608                   done = false;
1609                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
1610                   add_pointsto_edge(resproj->_idx, arg->_idx);
1611                 else
1612                   add_deferred_edge(resproj->_idx, arg->_idx);
1613                 arg_esp->_hidden_alias = true;
1614               }
1615             }
1616           }
1617           copy_dependencies = true;
1618         } else {
1619           set_escape_state(call->_idx, PointsToNode::GlobalEscape);
1620           if (resproj != NULL)
1621             add_pointsto_edge(resproj->_idx, _phantom_object);
1622           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1623             const Type* at = d->field_at(i);
1624             if (at->isa_oopptr() != NULL) {
1625               Node *arg = call->in(i)->uncast();
1626               PointsToNode *arg_esp = _nodes->adr_at(arg->_idx);
1627               arg_esp->_hidden_alias = true;
1628             }
1629           }
1630         }
1631         if (copy_dependencies)
1632           call_analyzer->copy_dependencies(C()->dependencies());
1633       }
1634       if (done)
1635         _processed.set(resproj->_idx);
1636       break;
1637     }
1638 
1639     default:
1640     // Some other type of call, assume the worst case that the
1641     // returned value, if any, globally escapes.
1642     {
1643       const TypeTuple *r = call->tf()->range();
1644       if (r->cnt() > TypeFunc::Parms) {
1645         const Type* ret_type = r->field_at(TypeFunc::Parms);
1646 
1647         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
1648         //        _multianewarray functions return a TypeRawPtr.
1649         if (ret_type->isa_ptr() != NULL) {
1650           PointsToNode *ptadr = ptnode_adr(call->_idx);
1651           set_escape_state(call->_idx, PointsToNode::GlobalEscape);
1652           if (resproj != NULL)
1653             add_pointsto_edge(resproj->_idx, _phantom_object);
1654         }
1655       }
1656       _processed.set(resproj->_idx);
1657     }
1658   }
1659 }
1660 
1661 // Populate Connection Graph with Ideal nodes and create simple
1662 // connection graph edges (do not need to check the node_type of inputs
1663 // or to call PointsTo() to walk the connection graph).
1664 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
1665   if (_processed.test(n->_idx))
1666     return; // No need to redefine node's state.
1667 
1668   if (n->is_Call()) {
1669     // Arguments to allocation and locking don't escape.
1670     if (n->is_Allocate()) {
1671       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
1672       record_for_optimizer(n);
1673     } else if (n->is_Lock() || n->is_Unlock()) {
1674       // Put Lock and Unlock nodes on IGVN worklist to process them during
1675       // the first IGVN optimization when escape information is still available.
1676       record_for_optimizer(n);
1677       _processed.set(n->_idx);
1678     } else {
1679       // Have to process call's arguments first.
1680       PointsToNode::NodeType nt = PointsToNode::UnknownType;
1681 
1682       // Check if a call returns an object.
1683       const TypeTuple *r = n->as_Call()->tf()->range();
1684       if (r->cnt() > TypeFunc::Parms &&
1685           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
1686         // Note:  use isa_ptr() instead of isa_oopptr() here because
1687         //        the _multianewarray functions return a TypeRawPtr.
1688         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
1689           nt = PointsToNode::JavaObject;
1690         }
1691       }
1692       add_node(n, nt, PointsToNode::UnknownEscape, false);
1693     }
1694     return;
1695   }
1696 
1697   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
1698   // ThreadLocal has RawPrt type.
1699   switch (n->Opcode()) {
1700     case Op_AddP:
1701     {
1702       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
1703       break;
1704     }
1705     case Op_CastX2P:
1706     { // "Unsafe" memory access.
1707       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1708       break;
1709     }
1710     case Op_CastPP:
1711     case Op_CheckCastPP:
1712     {
1713       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
1714       int ti = n->in(1)->_idx;
1715       PointsToNode::NodeType nt = _nodes->adr_at(ti)->node_type();
1716       if (nt == PointsToNode::UnknownType) {
1717         _delayed_worklist.push(n); // Process it later.
1718         break;
1719       } else if (nt == PointsToNode::JavaObject) {
1720         add_pointsto_edge(n->_idx, ti);
1721       } else {
1722         add_deferred_edge(n->_idx, ti);
1723       }
1724       _processed.set(n->_idx);
1725       break;
1726     }
1727     case Op_ConP:
1728     {
1729       // assume all pointer constants globally escape except for null
1730       PointsToNode::EscapeState es;
1731       if (phase->type(n) == TypePtr::NULL_PTR)
1732         es = PointsToNode::NoEscape;
1733       else
1734         es = PointsToNode::GlobalEscape;
1735 
1736       add_node(n, PointsToNode::JavaObject, es, true);
1737       break;
1738     }
1739     case Op_CreateEx:
1740     {
1741       // assume that all exception objects globally escape
1742       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1743       break;
1744     }
1745     case Op_LoadKlass:
1746     {
1747       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
1748       break;
1749     }
1750     case Op_LoadP:
1751     {
1752       const Type *t = phase->type(n);
1753       if (t->isa_ptr() == NULL) {
1754         _processed.set(n->_idx);
1755         return;
1756       }
1757       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
1758       break;
1759     }
1760     case Op_Parm:
1761     {
1762       _processed.set(n->_idx); // No need to redefine it state.
1763       uint con = n->as_Proj()->_con;
1764       if (con < TypeFunc::Parms)
1765         return;
1766       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
1767       if (t->isa_ptr() == NULL)
1768         return;
1769       // We have to assume all input parameters globally escape
1770       // (Note: passing 'false' since _processed is already set).
1771       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
1772       break;
1773     }
1774     case Op_Phi:
1775     {
1776       if (n->as_Phi()->type()->isa_ptr() == NULL) {
1777         // nothing to do if not an oop
1778         _processed.set(n->_idx);
1779         return;
1780       }
1781       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
1782       uint i;
1783       for (i = 1; i < n->req() ; i++) {
1784         Node* in = n->in(i);
1785         if (in == NULL)
1786           continue;  // ignore NULL
1787         in = in->uncast();
1788         if (in->is_top() || in == n)
1789           continue;  // ignore top or inputs which go back this node
1790         int ti = in->_idx;
1791         PointsToNode::NodeType nt = _nodes->adr_at(ti)->node_type();
1792         if (nt == PointsToNode::UnknownType) {
1793           break;
1794         } else if (nt == PointsToNode::JavaObject) {
1795           add_pointsto_edge(n->_idx, ti);
1796         } else {
1797           add_deferred_edge(n->_idx, ti);
1798         }
1799       }
1800       if (i >= n->req())
1801         _processed.set(n->_idx);
1802       else
1803         _delayed_worklist.push(n);
1804       break;
1805     }
1806     case Op_Proj:
1807     {
1808       // we are only interested in the result projection from a call
1809       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
1810         add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
1811         process_call_result(n->as_Proj(), phase);
1812         if (!_processed.test(n->_idx)) {
1813           // The call's result may need to be processed later if the call
1814           // returns it's argument and the argument is not processed yet.
1815           _delayed_worklist.push(n);
1816         }
1817       } else {
1818         _processed.set(n->_idx);
1819       }
1820       break;
1821     }
1822     case Op_Return:
1823     {
1824       if( n->req() > TypeFunc::Parms &&
1825           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
1826         // Treat Return value as LocalVar with GlobalEscape escape state.
1827         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
1828         int ti = n->in(TypeFunc::Parms)->_idx;
1829         PointsToNode::NodeType nt = _nodes->adr_at(ti)->node_type();
1830         if (nt == PointsToNode::UnknownType) {
1831           _delayed_worklist.push(n); // Process it later.
1832           break;
1833         } else if (nt == PointsToNode::JavaObject) {
1834           add_pointsto_edge(n->_idx, ti);
1835         } else {
1836           add_deferred_edge(n->_idx, ti);
1837         }
1838       }
1839       _processed.set(n->_idx);
1840       break;
1841     }
1842     case Op_StoreP:
1843     {
1844       const Type *adr_type = phase->type(n->in(MemNode::Address));
1845       if (adr_type->isa_oopptr()) {
1846         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
1847       } else {
1848         Node* adr = n->in(MemNode::Address);
1849         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
1850             adr->in(AddPNode::Address)->is_Proj() &&
1851             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
1852           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
1853           // We are computing a raw address for a store captured
1854           // by an Initialize compute an appropriate address type.
1855           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1856           assert(offs != Type::OffsetBot, "offset must be a constant");
1857         } else {
1858           _processed.set(n->_idx);
1859           return;
1860         }
1861       }
1862       break;
1863     }
1864     case Op_StorePConditional:
1865     case Op_CompareAndSwapP:
1866     {
1867       const Type *adr_type = phase->type(n->in(MemNode::Address));
1868       if (adr_type->isa_oopptr()) {
1869         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
1870       } else {
1871         _processed.set(n->_idx);
1872         return;
1873       }
1874       break;
1875     }
1876     case Op_ThreadLocal:
1877     {
1878       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
1879       break;
1880     }
1881     default:
1882       ;
1883       // nothing to do
1884   }
1885   return;
1886 }
1887 
1888 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
1889   // Don't set processed bit for AddP, LoadP, StoreP since
1890   // they may need more then one pass to process.
1891   if (_processed.test(n->_idx))
1892     return; // No need to redefine node's state.
1893 
1894   PointsToNode *ptadr = ptnode_adr(n->_idx);
1895 
1896   if (n->is_Call()) {
1897     CallNode *call = n->as_Call();
1898     process_call_arguments(call, phase);
1899     _processed.set(n->_idx);
1900     return;
1901   }
1902 
1903   switch (n->Opcode()) {
1904     case Op_AddP:
1905     {
1906       Node *base = get_addp_base(n);
1907       // Create a field edge to this node from everything base could point to.
1908       VectorSet ptset(Thread::current()->resource_area());
1909       PointsTo(ptset, base, phase);
1910       for( VectorSetI i(&ptset); i.test(); ++i ) {
1911         uint pt = i.elem;
1912         add_field_edge(pt, n->_idx, address_offset(n, phase));
1913       }
1914       break;
1915     }
1916     case Op_CastX2P:
1917     {
1918       assert(false, "Op_CastX2P");
1919       break;
1920     }
1921     case Op_CastPP:
1922     case Op_CheckCastPP:
1923     {
1924       int ti = n->in(1)->_idx;
1925       if (_nodes->adr_at(ti)->node_type() == PointsToNode::JavaObject) {
1926         add_pointsto_edge(n->_idx, ti);
1927       } else {
1928         add_deferred_edge(n->_idx, ti);
1929       }
1930       _processed.set(n->_idx);
1931       break;
1932     }
1933     case Op_ConP:
1934     {
1935       assert(false, "Op_ConP");
1936       break;
1937     }
1938     case Op_CreateEx:
1939     {
1940       assert(false, "Op_CreateEx");
1941       break;
1942     }
1943     case Op_LoadKlass:
1944     {
1945       assert(false, "Op_LoadKlass");
1946       break;
1947     }
1948     case Op_LoadP:
1949     {
1950       const Type *t = phase->type(n);
1951 #ifdef ASSERT
1952       if (t->isa_ptr() == NULL)
1953         assert(false, "Op_LoadP");
1954 #endif
1955 
1956       Node* adr = n->in(MemNode::Address)->uncast();
1957       const Type *adr_type = phase->type(adr);
1958       Node* adr_base;
1959       if (adr->is_AddP()) {
1960         adr_base = get_addp_base(adr);
1961       } else {
1962         adr_base = adr;
1963       }
1964 
1965       // For everything "adr_base" could point to, create a deferred edge from
1966       // this node to each field with the same offset.
1967       VectorSet ptset(Thread::current()->resource_area());
1968       PointsTo(ptset, adr_base, phase);
1969       int offset = address_offset(adr, phase);
1970       for( VectorSetI i(&ptset); i.test(); ++i ) {
1971         uint pt = i.elem;
1972         add_deferred_edge_to_fields(n->_idx, pt, offset);
1973       }
1974       break;
1975     }
1976     case Op_Parm:
1977     {
1978       assert(false, "Op_Parm");
1979       break;
1980     }
1981     case Op_Phi:
1982     {
1983 #ifdef ASSERT
1984       if (n->as_Phi()->type()->isa_ptr() == NULL)
1985         assert(false, "Op_Phi");
1986 #endif
1987       for (uint i = 1; i < n->req() ; i++) {
1988         Node* in = n->in(i);
1989         if (in == NULL)
1990           continue;  // ignore NULL
1991         in = in->uncast();
1992         if (in->is_top() || in == n)
1993           continue;  // ignore top or inputs which go back this node
1994         int ti = in->_idx;
1995         if (_nodes->adr_at(in->_idx)->node_type() == PointsToNode::JavaObject) {
1996           add_pointsto_edge(n->_idx, ti);
1997         } else {
1998           add_deferred_edge(n->_idx, ti);
1999         }
2000       }
2001       _processed.set(n->_idx);
2002       break;
2003     }
2004     case Op_Proj:
2005     {
2006       // we are only interested in the result projection from a call
2007       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2008         process_call_result(n->as_Proj(), phase);
2009         assert(_processed.test(n->_idx), "all call results should be processed");
2010       } else {
2011         assert(false, "Op_Proj");
2012       }
2013       break;
2014     }
2015     case Op_Return:
2016     {
2017 #ifdef ASSERT
2018       if( n->req() <= TypeFunc::Parms ||
2019           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2020         assert(false, "Op_Return");
2021       }
2022 #endif
2023       int ti = n->in(TypeFunc::Parms)->_idx;
2024       if (_nodes->adr_at(ti)->node_type() == PointsToNode::JavaObject) {
2025         add_pointsto_edge(n->_idx, ti);
2026       } else {
2027         add_deferred_edge(n->_idx, ti);
2028       }
2029       _processed.set(n->_idx);
2030       break;
2031     }
2032     case Op_StoreP:
2033     case Op_StorePConditional:
2034     case Op_CompareAndSwapP:
2035     {
2036       Node *adr = n->in(MemNode::Address);
2037       const Type *adr_type = phase->type(adr);
2038 #ifdef ASSERT
2039       if (!adr_type->isa_oopptr())
2040         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2041 #endif
2042 
2043       assert(adr->is_AddP(), "expecting an AddP");
2044       Node *adr_base = get_addp_base(adr);
2045       Node *val = n->in(MemNode::ValueIn)->uncast();
2046       // For everything "adr_base" could point to, create a deferred edge
2047       // to "val" from each field with the same offset.
2048       VectorSet ptset(Thread::current()->resource_area());
2049       PointsTo(ptset, adr_base, phase);
2050       for( VectorSetI i(&ptset); i.test(); ++i ) {
2051         uint pt = i.elem;
2052         add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2053       }
2054       break;
2055     }
2056     case Op_ThreadLocal:
2057     {
2058       assert(false, "Op_ThreadLocal");
2059       break;
2060     }
2061     default:
2062       ;
2063       // nothing to do
2064   }
2065 }
2066 
2067 #ifndef PRODUCT
2068 void ConnectionGraph::dump() {
2069   PhaseGVN  *igvn = _compile->initial_gvn();
2070   bool first = true;
2071 
2072   uint size = (uint)_nodes->length();
2073   for (uint ni = 0; ni < size; ni++) {
2074     PointsToNode *ptn = _nodes->adr_at(ni);
2075     PointsToNode::NodeType ptn_type = ptn->node_type();
2076 
2077     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2078       continue;
2079     PointsToNode::EscapeState es = escape_state(ptn->_node, igvn);
2080     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2081       if (first) {
2082         tty->cr();
2083         tty->print("======== Connection graph for ");
2084         C()->method()->print_short_name();
2085         tty->cr();
2086         first = false;
2087       }
2088       tty->print("%6d ", ni);
2089       ptn->dump();
2090       // Print all locals which reference this allocation
2091       for (uint li = ni; li < size; li++) {
2092         PointsToNode *ptn_loc = _nodes->adr_at(li);
2093         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2094         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2095              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2096           tty->print("%6d  LocalVar [[%d]]", li, ni);
2097           _nodes->adr_at(li)->_node->dump();
2098         }
2099       }
2100       if (Verbose) {
2101         // Print all fields which reference this allocation
2102         for (uint i = 0; i < ptn->edge_count(); i++) {
2103           uint ei = ptn->edge_target(i);
2104           tty->print("%6d  Field [[%d]]", ei, ni);
2105           _nodes->adr_at(ei)->_node->dump();
2106         }
2107       }
2108       tty->cr();
2109     }
2110   }
2111 }
2112 #endif