1 /*
   2  * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_escape.cpp.incl"
  27 
  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, PhaseIterGVN *igvn) :
  85   _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
  86   _processed(C->comp_arena()),
  87   _collecting(true),
  88   _progress(false),
  89   _compile(C),
  90   _igvn(igvn),
  91   _node_map(C->comp_arena()) {
  92 
  93   _phantom_object = C->top()->_idx,
  94   add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
  95 
  96   // Add ConP(#NULL) and ConN(#NULL) nodes.
  97   Node* oop_null = igvn->zerocon(T_OBJECT);
  98   _oop_null = oop_null->_idx;
  99   assert(_oop_null < C->unique(), "should be created already");
 100   add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
 101 
 102   if (UseCompressedOops) {
 103     Node* noop_null = igvn->zerocon(T_NARROWOOP);
 104     _noop_null = noop_null->_idx;
 105     assert(_noop_null < C->unique(), "should be created already");
 106     add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
 107   }
 108 }
 109 
 110 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
 111   PointsToNode *f = ptnode_adr(from_i);
 112   PointsToNode *t = ptnode_adr(to_i);
 113 
 114   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 115   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
 116   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
 117   add_edge(f, to_i, PointsToNode::PointsToEdge);
 118 }
 119 
 120 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
 121   PointsToNode *f = ptnode_adr(from_i);
 122   PointsToNode *t = ptnode_adr(to_i);
 123 
 124   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 125   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
 126   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
 127   // don't add a self-referential edge, this can occur during removal of
 128   // deferred edges
 129   if (from_i != to_i)
 130     add_edge(f, to_i, PointsToNode::DeferredEdge);
 131 }
 132 
 133 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
 134   const Type *adr_type = phase->type(adr);
 135   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
 136       adr->in(AddPNode::Address)->is_Proj() &&
 137       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
 138     // We are computing a raw address for a store captured by an Initialize
 139     // compute an appropriate address type. AddP cases #3 and #5 (see below).
 140     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 141     assert(offs != Type::OffsetBot ||
 142            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
 143            "offset must be a constant or it is initialization of array");
 144     return offs;
 145   }
 146   const TypePtr *t_ptr = adr_type->isa_ptr();
 147   assert(t_ptr != NULL, "must be a pointer type");
 148   return t_ptr->offset();
 149 }
 150 
 151 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
 152   PointsToNode *f = ptnode_adr(from_i);
 153   PointsToNode *t = ptnode_adr(to_i);
 154 
 155   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 156   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
 157   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
 158   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
 159   t->set_offset(offset);
 160 
 161   add_edge(f, to_i, PointsToNode::FieldEdge);
 162 }
 163 
 164 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
 165   PointsToNode *npt = ptnode_adr(ni);
 166   PointsToNode::EscapeState old_es = npt->escape_state();
 167   if (es > old_es)
 168     npt->set_escape_state(es);
 169 }
 170 
 171 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
 172                                PointsToNode::EscapeState es, bool done) {
 173   PointsToNode* ptadr = ptnode_adr(n->_idx);
 174   ptadr->_node = n;
 175   ptadr->set_node_type(nt);
 176 
 177   // inline set_escape_state(idx, es);
 178   PointsToNode::EscapeState old_es = ptadr->escape_state();
 179   if (es > old_es)
 180     ptadr->set_escape_state(es);
 181 
 182   if (done)
 183     _processed.set(n->_idx);
 184 }
 185 
 186 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
 187   uint idx = n->_idx;
 188   PointsToNode::EscapeState es;
 189 
 190   // If we are still collecting or there were no non-escaping allocations
 191   // we don't know the answer yet
 192   if (_collecting)
 193     return PointsToNode::UnknownEscape;
 194 
 195   // if the node was created after the escape computation, return
 196   // UnknownEscape
 197   if (idx >= nodes_size())
 198     return PointsToNode::UnknownEscape;
 199 
 200   es = ptnode_adr(idx)->escape_state();
 201 
 202   // if we have already computed a value, return it
 203   if (es != PointsToNode::UnknownEscape &&
 204       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
 205     return es;
 206 
 207   // PointsTo() calls n->uncast() which can return a new ideal node.
 208   if (n->uncast()->_idx >= nodes_size())
 209     return PointsToNode::UnknownEscape;
 210 
 211   PointsToNode::EscapeState orig_es = es;
 212 
 213   // compute max escape state of anything this node could point to
 214   VectorSet ptset(Thread::current()->resource_area());
 215   PointsTo(ptset, n);
 216   for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
 217     uint pt = i.elem;
 218     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
 219     if (pes > es)
 220       es = pes;
 221   }
 222   if (orig_es != es) {
 223     // cache the computed escape state
 224     assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
 225     ptnode_adr(idx)->set_escape_state(es);
 226   } // orig_es could be PointsToNode::UnknownEscape
 227   return es;
 228 }
 229 
 230 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n) {
 231   VectorSet visited(Thread::current()->resource_area());
 232   GrowableArray<uint>  worklist;
 233 
 234 #ifdef ASSERT
 235   Node *orig_n = n;
 236 #endif
 237 
 238   n = n->uncast();
 239   PointsToNode* npt = ptnode_adr(n->_idx);
 240 
 241   // If we have a JavaObject, return just that object
 242   if (npt->node_type() == PointsToNode::JavaObject) {
 243     ptset.set(n->_idx);
 244     return;
 245   }
 246 #ifdef ASSERT
 247   if (npt->_node == NULL) {
 248     if (orig_n != n)
 249       orig_n->dump();
 250     n->dump();
 251     assert(npt->_node != NULL, "unregistered node");
 252   }
 253 #endif
 254   worklist.push(n->_idx);
 255   while(worklist.length() > 0) {
 256     int ni = worklist.pop();
 257     if (visited.test_set(ni))
 258       continue;
 259 
 260     PointsToNode* pn = ptnode_adr(ni);
 261     // ensure that all inputs of a Phi have been processed
 262     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
 263 
 264     int edges_processed = 0;
 265     uint e_cnt = pn->edge_count();
 266     for (uint e = 0; e < e_cnt; e++) {
 267       uint etgt = pn->edge_target(e);
 268       PointsToNode::EdgeType et = pn->edge_type(e);
 269       if (et == PointsToNode::PointsToEdge) {
 270         ptset.set(etgt);
 271         edges_processed++;
 272       } else if (et == PointsToNode::DeferredEdge) {
 273         worklist.push(etgt);
 274         edges_processed++;
 275       } else {
 276         assert(false,"neither PointsToEdge or DeferredEdge");
 277       }
 278     }
 279     if (edges_processed == 0) {
 280       // no deferred or pointsto edges found.  Assume the value was set
 281       // outside this method.  Add the phantom object to the pointsto set.
 282       ptset.set(_phantom_object);
 283     }
 284   }
 285 }
 286 
 287 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
 288   // This method is most expensive during ConnectionGraph construction.
 289   // Reuse vectorSet and an additional growable array for deferred edges.
 290   deferred_edges->clear();
 291   visited->Clear();
 292 
 293   visited->set(ni);
 294   PointsToNode *ptn = ptnode_adr(ni);
 295 
 296   // Mark current edges as visited and move deferred edges to separate array.
 297   for (uint i = 0; i < ptn->edge_count(); ) {
 298     uint t = ptn->edge_target(i);
 299 #ifdef ASSERT
 300     assert(!visited->test_set(t), "expecting no duplications");
 301 #else
 302     visited->set(t);
 303 #endif
 304     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
 305       ptn->remove_edge(t, PointsToNode::DeferredEdge);
 306       deferred_edges->append(t);
 307     } else {
 308       i++;
 309     }
 310   }
 311   for (int next = 0; next < deferred_edges->length(); ++next) {
 312     uint t = deferred_edges->at(next);
 313     PointsToNode *ptt = ptnode_adr(t);
 314     uint e_cnt = ptt->edge_count();
 315     for (uint e = 0; e < e_cnt; e++) {
 316       uint etgt = ptt->edge_target(e);
 317       if (visited->test_set(etgt))
 318         continue;
 319 
 320       PointsToNode::EdgeType et = ptt->edge_type(e);
 321       if (et == PointsToNode::PointsToEdge) {
 322         add_pointsto_edge(ni, etgt);
 323         if(etgt == _phantom_object) {
 324           // Special case - field set outside (globally escaping).
 325           ptn->set_escape_state(PointsToNode::GlobalEscape);
 326         }
 327       } else if (et == PointsToNode::DeferredEdge) {
 328         deferred_edges->append(etgt);
 329       } else {
 330         assert(false,"invalid connection graph");
 331       }
 332     }
 333   }
 334 }
 335 
 336 
 337 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
 338 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
 339 //  a pointsto edge is added if it is a JavaObject
 340 
 341 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
 342   PointsToNode* an = ptnode_adr(adr_i);
 343   PointsToNode* to = ptnode_adr(to_i);
 344   bool deferred = (to->node_type() == PointsToNode::LocalVar);
 345 
 346   for (uint fe = 0; fe < an->edge_count(); fe++) {
 347     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
 348     int fi = an->edge_target(fe);
 349     PointsToNode* pf = ptnode_adr(fi);
 350     int po = pf->offset();
 351     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
 352       if (deferred)
 353         add_deferred_edge(fi, to_i);
 354       else
 355         add_pointsto_edge(fi, to_i);
 356     }
 357   }
 358 }
 359 
 360 // Add a deferred  edge from node given by "from_i" to any field of adr_i
 361 // whose offset matches "offset".
 362 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
 363   PointsToNode* an = ptnode_adr(adr_i);
 364   for (uint fe = 0; fe < an->edge_count(); fe++) {
 365     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
 366     int fi = an->edge_target(fe);
 367     PointsToNode* pf = ptnode_adr(fi);
 368     int po = pf->offset();
 369     if (pf->edge_count() == 0) {
 370       // we have not seen any stores to this field, assume it was set outside this method
 371       add_pointsto_edge(fi, _phantom_object);
 372     }
 373     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
 374       add_deferred_edge(from_i, fi);
 375     }
 376   }
 377 }
 378 
 379 // Helper functions
 380 
 381 static Node* get_addp_base(Node *addp) {
 382   assert(addp->is_AddP(), "must be AddP");
 383   //
 384   // AddP cases for Base and Address inputs:
 385   // case #1. Direct object's field reference:
 386   //     Allocate
 387   //       |
 388   //     Proj #5 ( oop result )
 389   //       |
 390   //     CheckCastPP (cast to instance type)
 391   //      | |
 392   //     AddP  ( base == address )
 393   //
 394   // case #2. Indirect object's field reference:
 395   //      Phi
 396   //       |
 397   //     CastPP (cast to instance type)
 398   //      | |
 399   //     AddP  ( base == address )
 400   //
 401   // case #3. Raw object's field reference for Initialize node:
 402   //      Allocate
 403   //        |
 404   //      Proj #5 ( oop result )
 405   //  top   |
 406   //     \  |
 407   //     AddP  ( base == top )
 408   //
 409   // case #4. Array's element reference:
 410   //   {CheckCastPP | CastPP}
 411   //     |  | |
 412   //     |  AddP ( array's element offset )
 413   //     |  |
 414   //     AddP ( array's offset )
 415   //
 416   // case #5. Raw object's field reference for arraycopy stub call:
 417   //          The inline_native_clone() case when the arraycopy stub is called
 418   //          after the allocation before Initialize and CheckCastPP nodes.
 419   //      Allocate
 420   //        |
 421   //      Proj #5 ( oop result )
 422   //       | |
 423   //       AddP  ( base == address )
 424   //
 425   // case #6. Constant Pool, ThreadLocal, CastX2P or
 426   //          Raw object's field reference:
 427   //      {ConP, ThreadLocal, CastX2P, raw Load}
 428   //  top   |
 429   //     \  |
 430   //     AddP  ( base == top )
 431   //
 432   // case #7. Klass's field reference.
 433   //      LoadKlass
 434   //       | |
 435   //       AddP  ( base == address )
 436   //
 437   // case #8. narrow Klass's field reference.
 438   //      LoadNKlass
 439   //       |
 440   //      DecodeN
 441   //       | |
 442   //       AddP  ( base == address )
 443   //
 444   Node *base = addp->in(AddPNode::Base)->uncast();
 445   if (base->is_top()) { // The AddP case #3 and #6.
 446     base = addp->in(AddPNode::Address)->uncast();
 447     while (base->is_AddP()) {
 448       // Case #6 (unsafe access) may have several chained AddP nodes.
 449       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
 450       base = base->in(AddPNode::Address)->uncast();
 451     }
 452     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
 453            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
 454            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
 455            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
 456   }
 457   return base;
 458 }
 459 
 460 static Node* find_second_addp(Node* addp, Node* n) {
 461   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
 462 
 463   Node* addp2 = addp->raw_out(0);
 464   if (addp->outcnt() == 1 && addp2->is_AddP() &&
 465       addp2->in(AddPNode::Base) == n &&
 466       addp2->in(AddPNode::Address) == addp) {
 467 
 468     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
 469     //
 470     // Find array's offset to push it on worklist first and
 471     // as result process an array's element offset first (pushed second)
 472     // to avoid CastPP for the array's offset.
 473     // Otherwise the inserted CastPP (LocalVar) will point to what
 474     // the AddP (Field) points to. Which would be wrong since
 475     // the algorithm expects the CastPP has the same point as
 476     // as AddP's base CheckCastPP (LocalVar).
 477     //
 478     //    ArrayAllocation
 479     //     |
 480     //    CheckCastPP
 481     //     |
 482     //    memProj (from ArrayAllocation CheckCastPP)
 483     //     |  ||
 484     //     |  ||   Int (element index)
 485     //     |  ||    |   ConI (log(element size))
 486     //     |  ||    |   /
 487     //     |  ||   LShift
 488     //     |  ||  /
 489     //     |  AddP (array's element offset)
 490     //     |  |
 491     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
 492     //     | / /
 493     //     AddP (array's offset)
 494     //      |
 495     //     Load/Store (memory operation on array's element)
 496     //
 497     return addp2;
 498   }
 499   return NULL;
 500 }
 501 
 502 //
 503 // Adjust the type and inputs of an AddP which computes the
 504 // address of a field of an instance
 505 //
 506 bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
 507   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
 508   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
 509   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
 510   if (t == NULL) {
 511     // We are computing a raw address for a store captured by an Initialize
 512     // compute an appropriate address type (cases #3 and #5).
 513     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
 514     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
 515     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
 516     assert(offs != Type::OffsetBot, "offset must be a constant");
 517     t = base_t->add_offset(offs)->is_oopptr();
 518   }
 519   int inst_id =  base_t->instance_id();
 520   assert(!t->is_known_instance() || t->instance_id() == inst_id,
 521                              "old type must be non-instance or match new type");
 522 
 523   // The type 't' could be subclass of 'base_t'.
 524   // As result t->offset() could be large then base_t's size and it will
 525   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
 526   // constructor verifies correctness of the offset.
 527   //
 528   // It could happened on subclass's branch (from the type profiling
 529   // inlining) which was not eliminated during parsing since the exactness
 530   // of the allocation type was not propagated to the subclass type check.
 531   //
 532   // Or the type 't' could be not related to 'base_t' at all.
 533   // It could happened when CHA type is different from MDO type on a dead path
 534   // (for example, from instanceof check) which is not collapsed during parsing.
 535   //
 536   // Do nothing for such AddP node and don't process its users since
 537   // this code branch will go away.
 538   //
 539   if (!t->is_known_instance() &&
 540       !base_t->klass()->is_subtype_of(t->klass())) {
 541      return false; // bail out
 542   }
 543 
 544   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
 545   // Do NOT remove the next line: ensure a new alias index is allocated
 546   // for the instance type. Note: C++ will not remove it since the call
 547   // has side effect.
 548   int alias_idx = _compile->get_alias_index(tinst);
 549   igvn->set_type(addp, tinst);
 550   // record the allocation in the node map
 551   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
 552   set_map(addp->_idx, get_map(base->_idx));
 553 
 554   // Set addp's Base and Address to 'base'.
 555   Node *abase = addp->in(AddPNode::Base);
 556   Node *adr   = addp->in(AddPNode::Address);
 557   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
 558       adr->in(0)->_idx == (uint)inst_id) {
 559     // Skip AddP cases #3 and #5.
 560   } else {
 561     assert(!abase->is_top(), "sanity"); // AddP case #3
 562     if (abase != base) {
 563       igvn->hash_delete(addp);
 564       addp->set_req(AddPNode::Base, base);
 565       if (abase == adr) {
 566         addp->set_req(AddPNode::Address, base);
 567       } else {
 568         // AddP case #4 (adr is array's element offset AddP node)
 569 #ifdef ASSERT
 570         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
 571         assert(adr->is_AddP() && atype != NULL &&
 572                atype->instance_id() == inst_id, "array's element offset should be processed first");
 573 #endif
 574       }
 575       igvn->hash_insert(addp);
 576     }
 577   }
 578   // Put on IGVN worklist since at least addp's type was changed above.
 579   record_for_optimizer(addp);
 580   return true;
 581 }
 582 
 583 //
 584 // Create a new version of orig_phi if necessary. Returns either the newly
 585 // created phi or an existing phi.  Sets create_new to indicate wheter  a new
 586 // phi was created.  Cache the last newly created phi in the node map.
 587 //
 588 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
 589   Compile *C = _compile;
 590   new_created = false;
 591   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
 592   // nothing to do if orig_phi is bottom memory or matches alias_idx
 593   if (phi_alias_idx == alias_idx) {
 594     return orig_phi;
 595   }
 596   // Have we recently created a Phi for this alias index?
 597   PhiNode *result = get_map_phi(orig_phi->_idx);
 598   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
 599     return result;
 600   }
 601   // Previous check may fail when the same wide memory Phi was split into Phis
 602   // for different memory slices. Search all Phis for this region.
 603   if (result != NULL) {
 604     Node* region = orig_phi->in(0);
 605     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
 606       Node* phi = region->fast_out(i);
 607       if (phi->is_Phi() &&
 608           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
 609         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
 610         return phi->as_Phi();
 611       }
 612     }
 613   }
 614   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
 615     if (C->do_escape_analysis() == true && !C->failing()) {
 616       // Retry compilation without escape analysis.
 617       // If this is the first failure, the sentinel string will "stick"
 618       // to the Compile object, and the C2Compiler will see it and retry.
 619       C->record_failure(C2Compiler::retry_no_escape_analysis());
 620     }
 621     return NULL;
 622   }
 623   orig_phi_worklist.append_if_missing(orig_phi);
 624   const TypePtr *atype = C->get_adr_type(alias_idx);
 625   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
 626   C->copy_node_notes_to(result, orig_phi);
 627   igvn->set_type(result, result->bottom_type());
 628   record_for_optimizer(result);
 629 
 630   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
 631   assert(pn == NULL || pn == orig_phi, "wrong node");
 632   set_map(orig_phi->_idx, result);
 633   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
 634 
 635   new_created = true;
 636   return result;
 637 }
 638 
 639 //
 640 // Return a new version  of Memory Phi "orig_phi" with the inputs having the
 641 // specified alias index.
 642 //
 643 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
 644 
 645   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
 646   Compile *C = _compile;
 647   bool new_phi_created;
 648   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
 649   if (!new_phi_created) {
 650     return result;
 651   }
 652 
 653   GrowableArray<PhiNode *>  phi_list;
 654   GrowableArray<uint>  cur_input;
 655 
 656   PhiNode *phi = orig_phi;
 657   uint idx = 1;
 658   bool finished = false;
 659   while(!finished) {
 660     while (idx < phi->req()) {
 661       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
 662       if (mem != NULL && mem->is_Phi()) {
 663         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
 664         if (new_phi_created) {
 665           // found an phi for which we created a new split, push current one on worklist and begin
 666           // processing new one
 667           phi_list.push(phi);
 668           cur_input.push(idx);
 669           phi = mem->as_Phi();
 670           result = newphi;
 671           idx = 1;
 672           continue;
 673         } else {
 674           mem = newphi;
 675         }
 676       }
 677       if (C->failing()) {
 678         return NULL;
 679       }
 680       result->set_req(idx++, mem);
 681     }
 682 #ifdef ASSERT
 683     // verify that the new Phi has an input for each input of the original
 684     assert( phi->req() == result->req(), "must have same number of inputs.");
 685     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
 686 #endif
 687     // Check if all new phi's inputs have specified alias index.
 688     // Otherwise use old phi.
 689     for (uint i = 1; i < phi->req(); i++) {
 690       Node* in = result->in(i);
 691       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
 692     }
 693     // we have finished processing a Phi, see if there are any more to do
 694     finished = (phi_list.length() == 0 );
 695     if (!finished) {
 696       phi = phi_list.pop();
 697       idx = cur_input.pop();
 698       PhiNode *prev_result = get_map_phi(phi->_idx);
 699       prev_result->set_req(idx++, result);
 700       result = prev_result;
 701     }
 702   }
 703   return result;
 704 }
 705 
 706 
 707 //
 708 // The next methods are derived from methods in MemNode.
 709 //
 710 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
 711   Node *mem = mmem;
 712   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
 713   // means an array I have not precisely typed yet.  Do not do any
 714   // alias stuff with it any time soon.
 715   if( toop->base() != Type::AnyPtr &&
 716       !(toop->klass() != NULL &&
 717         toop->klass()->is_java_lang_Object() &&
 718         toop->offset() == Type::OffsetBot) ) {
 719     mem = mmem->memory_at(alias_idx);
 720     // Update input if it is progress over what we have now
 721   }
 722   return mem;
 723 }
 724 
 725 //
 726 // Move memory users to their memory slices.
 727 //
 728 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
 729   Compile* C = _compile;
 730 
 731   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
 732   assert(tp != NULL, "ptr type");
 733   int alias_idx = C->get_alias_index(tp);
 734   int general_idx = C->get_general_index(alias_idx);
 735 
 736   // Move users first
 737   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 738     Node* use = n->fast_out(i);
 739     if (use->is_MergeMem()) {
 740       MergeMemNode* mmem = use->as_MergeMem();
 741       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
 742       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
 743         continue; // Nothing to do
 744       }
 745       // Replace previous general reference to mem node.
 746       uint orig_uniq = C->unique();
 747       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
 748       assert(orig_uniq == C->unique(), "no new nodes");
 749       mmem->set_memory_at(general_idx, m);
 750       --imax;
 751       --i;
 752     } else if (use->is_MemBar()) {
 753       assert(!use->is_Initialize(), "initializing stores should not be moved");
 754       if (use->req() > MemBarNode::Precedent &&
 755           use->in(MemBarNode::Precedent) == n) {
 756         // Don't move related membars.
 757         record_for_optimizer(use);
 758         continue;
 759       }
 760       tp = use->as_MemBar()->adr_type()->isa_ptr();
 761       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
 762           alias_idx == general_idx) {
 763         continue; // Nothing to do
 764       }
 765       // Move to general memory slice.
 766       uint orig_uniq = C->unique();
 767       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
 768       assert(orig_uniq == C->unique(), "no new nodes");
 769       igvn->hash_delete(use);
 770       imax -= use->replace_edge(n, m);
 771       igvn->hash_insert(use);
 772       record_for_optimizer(use);
 773       --i;
 774 #ifdef ASSERT
 775     } else if (use->is_Mem()) {
 776       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
 777         // Don't move related cardmark.
 778         continue;
 779       }
 780       // Memory nodes should have new memory input.
 781       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
 782       assert(tp != NULL, "ptr type");
 783       int idx = C->get_alias_index(tp);
 784       assert(get_map(use->_idx) != NULL || idx == alias_idx,
 785              "Following memory nodes should have new memory input or be on the same memory slice");
 786     } else if (use->is_Phi()) {
 787       // Phi nodes should be split and moved already.
 788       tp = use->as_Phi()->adr_type()->isa_ptr();
 789       assert(tp != NULL, "ptr type");
 790       int idx = C->get_alias_index(tp);
 791       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
 792     } else {
 793       use->dump();
 794       assert(false, "should not be here");
 795 #endif
 796     }
 797   }
 798 }
 799 
 800 //
 801 // Search memory chain of "mem" to find a MemNode whose address
 802 // is the specified alias index.
 803 //
 804 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
 805   if (orig_mem == NULL)
 806     return orig_mem;
 807   Compile* C = phase->C;
 808   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
 809   bool is_instance = (toop != NULL) && toop->is_known_instance();
 810   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
 811   Node *prev = NULL;
 812   Node *result = orig_mem;
 813   while (prev != result) {
 814     prev = result;
 815     if (result == start_mem)
 816       break;  // hit one of our sentinels
 817     if (result->is_Mem()) {
 818       const Type *at = phase->type(result->in(MemNode::Address));
 819       if (at != Type::TOP) {
 820         assert (at->isa_ptr() != NULL, "pointer type required.");
 821         int idx = C->get_alias_index(at->is_ptr());
 822         if (idx == alias_idx)
 823           break;
 824       }
 825       result = result->in(MemNode::Memory);
 826     }
 827     if (!is_instance)
 828       continue;  // don't search further for non-instance types
 829     // skip over a call which does not affect this memory slice
 830     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
 831       Node *proj_in = result->in(0);
 832       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
 833         break;  // hit one of our sentinels
 834       } else if (proj_in->is_Call()) {
 835         CallNode *call = proj_in->as_Call();
 836         if (!call->may_modify(toop, phase)) {
 837           result = call->in(TypeFunc::Memory);
 838         }
 839       } else if (proj_in->is_Initialize()) {
 840         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
 841         // Stop if this is the initialization for the object instance which
 842         // which contains this memory slice, otherwise skip over it.
 843         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
 844           result = proj_in->in(TypeFunc::Memory);
 845         }
 846       } else if (proj_in->is_MemBar()) {
 847         result = proj_in->in(TypeFunc::Memory);
 848       }
 849     } else if (result->is_MergeMem()) {
 850       MergeMemNode *mmem = result->as_MergeMem();
 851       result = step_through_mergemem(mmem, alias_idx, toop);
 852       if (result == mmem->base_memory()) {
 853         // Didn't find instance memory, search through general slice recursively.
 854         result = mmem->memory_at(C->get_general_index(alias_idx));
 855         result = find_inst_mem(result, alias_idx, orig_phis, phase);
 856         if (C->failing()) {
 857           return NULL;
 858         }
 859         mmem->set_memory_at(alias_idx, result);
 860       }
 861     } else if (result->is_Phi() &&
 862                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
 863       Node *un = result->as_Phi()->unique_input(phase);
 864       if (un != NULL) {
 865         orig_phis.append_if_missing(result->as_Phi());
 866         result = un;
 867       } else {
 868         break;
 869       }
 870     } else if (result->is_ClearArray()) {
 871       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
 872         // Can not bypass initialization of the instance
 873         // we are looking for.
 874         break;
 875       }
 876       // Otherwise skip it (the call updated 'result' value).
 877     } else if (result->Opcode() == Op_SCMemProj) {
 878       assert(result->in(0)->is_LoadStore(), "sanity");
 879       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
 880       if (at != Type::TOP) {
 881         assert (at->isa_ptr() != NULL, "pointer type required.");
 882         int idx = C->get_alias_index(at->is_ptr());
 883         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
 884         break;
 885       }
 886       result = result->in(0)->in(MemNode::Memory);
 887     }
 888   }
 889   if (result->is_Phi()) {
 890     PhiNode *mphi = result->as_Phi();
 891     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
 892     const TypePtr *t = mphi->adr_type();
 893     if (C->get_alias_index(t) != alias_idx) {
 894       // Create a new Phi with the specified alias index type.
 895       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
 896     } else if (!is_instance) {
 897       // Push all non-instance Phis on the orig_phis worklist to update inputs
 898       // during Phase 4 if needed.
 899       orig_phis.append_if_missing(mphi);
 900     }
 901   }
 902   // the result is either MemNode, PhiNode, InitializeNode.
 903   return result;
 904 }
 905 
 906 //
 907 //  Convert the types of unescaped object to instance types where possible,
 908 //  propagate the new type information through the graph, and update memory
 909 //  edges and MergeMem inputs to reflect the new type.
 910 //
 911 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
 912 //  The processing is done in 4 phases:
 913 //
 914 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
 915 //            types for the CheckCastPP for allocations where possible.
 916 //            Propagate the the new types through users as follows:
 917 //               casts and Phi:  push users on alloc_worklist
 918 //               AddP:  cast Base and Address inputs to the instance type
 919 //                      push any AddP users on alloc_worklist and push any memnode
 920 //                      users onto memnode_worklist.
 921 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
 922 //            search the Memory chain for a store with the appropriate type
 923 //            address type.  If a Phi is found, create a new version with
 924 //            the appropriate memory slices from each of the Phi inputs.
 925 //            For stores, process the users as follows:
 926 //               MemNode:  push on memnode_worklist
 927 //               MergeMem: push on mergemem_worklist
 928 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
 929 //            moving the first node encountered of each  instance type to the
 930 //            the input corresponding to its alias index.
 931 //            appropriate memory slice.
 932 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
 933 //
 934 // In the following example, the CheckCastPP nodes are the cast of allocation
 935 // results and the allocation of node 29 is unescaped and eligible to be an
 936 // instance type.
 937 //
 938 // We start with:
 939 //
 940 //     7 Parm #memory
 941 //    10  ConI  "12"
 942 //    19  CheckCastPP   "Foo"
 943 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 944 //    29  CheckCastPP   "Foo"
 945 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
 946 //
 947 //    40  StoreP  25   7  20   ... alias_index=4
 948 //    50  StoreP  35  40  30   ... alias_index=4
 949 //    60  StoreP  45  50  20   ... alias_index=4
 950 //    70  LoadP    _  60  30   ... alias_index=4
 951 //    80  Phi     75  50  60   Memory alias_index=4
 952 //    90  LoadP    _  80  30   ... alias_index=4
 953 //   100  LoadP    _  80  20   ... alias_index=4
 954 //
 955 //
 956 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
 957 // and creating a new alias index for node 30.  This gives:
 958 //
 959 //     7 Parm #memory
 960 //    10  ConI  "12"
 961 //    19  CheckCastPP   "Foo"
 962 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 963 //    29  CheckCastPP   "Foo"  iid=24
 964 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
 965 //
 966 //    40  StoreP  25   7  20   ... alias_index=4
 967 //    50  StoreP  35  40  30   ... alias_index=6
 968 //    60  StoreP  45  50  20   ... alias_index=4
 969 //    70  LoadP    _  60  30   ... alias_index=6
 970 //    80  Phi     75  50  60   Memory alias_index=4
 971 //    90  LoadP    _  80  30   ... alias_index=6
 972 //   100  LoadP    _  80  20   ... alias_index=4
 973 //
 974 // In phase 2, new memory inputs are computed for the loads and stores,
 975 // And a new version of the phi is created.  In phase 4, the inputs to
 976 // node 80 are updated and then the memory nodes are updated with the
 977 // values computed in phase 2.  This results in:
 978 //
 979 //     7 Parm #memory
 980 //    10  ConI  "12"
 981 //    19  CheckCastPP   "Foo"
 982 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
 983 //    29  CheckCastPP   "Foo"  iid=24
 984 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
 985 //
 986 //    40  StoreP  25  7   20   ... alias_index=4
 987 //    50  StoreP  35  7   30   ... alias_index=6
 988 //    60  StoreP  45  40  20   ... alias_index=4
 989 //    70  LoadP    _  50  30   ... alias_index=6
 990 //    80  Phi     75  40  60   Memory alias_index=4
 991 //   120  Phi     75  50  50   Memory alias_index=6
 992 //    90  LoadP    _ 120  30   ... alias_index=6
 993 //   100  LoadP    _  80  20   ... alias_index=4
 994 //
 995 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
 996   GrowableArray<Node *>  memnode_worklist;
 997   GrowableArray<PhiNode *>  orig_phis;
 998 
 999   PhaseIterGVN  *igvn = _igvn;
1000   uint new_index_start = (uint) _compile->num_alias_types();
1001   Arena* arena = Thread::current()->resource_area();
1002   VectorSet visited(arena);
1003   VectorSet ptset(arena);
1004 
1005 
1006   //  Phase 1:  Process possible allocations from alloc_worklist.
1007   //  Create instance types for the CheckCastPP for allocations where possible.
1008   //
1009   // (Note: don't forget to change the order of the second AddP node on
1010   //  the alloc_worklist if the order of the worklist processing is changed,
1011   //  see the comment in find_second_addp().)
1012   //
1013   while (alloc_worklist.length() != 0) {
1014     Node *n = alloc_worklist.pop();
1015     uint ni = n->_idx;
1016     const TypeOopPtr* tinst = NULL;
1017     if (n->is_Call()) {
1018       CallNode *alloc = n->as_Call();
1019       // copy escape information to call node
1020       PointsToNode* ptn = ptnode_adr(alloc->_idx);
1021       PointsToNode::EscapeState es = escape_state(alloc);
1022       // We have an allocation or call which returns a Java object,
1023       // see if it is unescaped.
1024       if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
1025         continue;
1026 
1027       // Find CheckCastPP for the allocate or for the return value of a call
1028       n = alloc->result_cast();
1029       if (n == NULL) {            // No uses except Initialize node
1030         if (alloc->is_Allocate()) {
1031           // Set the scalar_replaceable flag for allocation
1032           // so it could be eliminated if it has no uses.
1033           alloc->as_Allocate()->_is_scalar_replaceable = true;
1034         }
1035         continue;
1036       }
1037       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1038         assert(!alloc->is_Allocate(), "allocation should have unique type");
1039         continue;
1040       }
1041 
1042       // The inline code for Object.clone() casts the allocation result to
1043       // java.lang.Object and then to the actual type of the allocated
1044       // object. Detect this case and use the second cast.
1045       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
1046       // the allocation result is cast to java.lang.Object and then
1047       // to the actual Array type.
1048       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
1049           && (alloc->is_AllocateArray() ||
1050               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
1051         Node *cast2 = NULL;
1052         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1053           Node *use = n->fast_out(i);
1054           if (use->is_CheckCastPP()) {
1055             cast2 = use;
1056             break;
1057           }
1058         }
1059         if (cast2 != NULL) {
1060           n = cast2;
1061         } else {
1062           // Non-scalar replaceable if the allocation type is unknown statically
1063           // (reflection allocation), the object can't be restored during
1064           // deoptimization without precise type.
1065           continue;
1066         }
1067       }
1068       if (alloc->is_Allocate()) {
1069         // Set the scalar_replaceable flag for allocation
1070         // so it could be eliminated.
1071         alloc->as_Allocate()->_is_scalar_replaceable = true;
1072       }
1073       set_escape_state(n->_idx, es);
1074       // in order for an object to be scalar-replaceable, it must be:
1075       //   - a direct allocation (not a call returning an object)
1076       //   - non-escaping
1077       //   - eligible to be a unique type
1078       //   - not determined to be ineligible by escape analysis
1079       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1080              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1081       set_map(alloc->_idx, n);
1082       set_map(n->_idx, alloc);
1083       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1084       if (t == NULL)
1085         continue;  // not a TypeInstPtr
1086       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1087       igvn->hash_delete(n);
1088       igvn->set_type(n,  tinst);
1089       n->raise_bottom_type(tinst);
1090       igvn->hash_insert(n);
1091       record_for_optimizer(n);
1092       if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
1093           (t->isa_instptr() || t->isa_aryptr())) {
1094 
1095         // First, put on the worklist all Field edges from Connection Graph
1096         // which is more accurate then putting immediate users from Ideal Graph.
1097         for (uint e = 0; e < ptn->edge_count(); e++) {
1098           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1099           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
1100                  "only AddP nodes are Field edges in CG");
1101           if (use->outcnt() > 0) { // Don't process dead nodes
1102             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1103             if (addp2 != NULL) {
1104               assert(alloc->is_AllocateArray(),"array allocation was expected");
1105               alloc_worklist.append_if_missing(addp2);
1106             }
1107             alloc_worklist.append_if_missing(use);
1108           }
1109         }
1110 
1111         // An allocation may have an Initialize which has raw stores. Scan
1112         // the users of the raw allocation result and push AddP users
1113         // on alloc_worklist.
1114         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1115         assert (raw_result != NULL, "must have an allocation result");
1116         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1117           Node *use = raw_result->fast_out(i);
1118           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1119             Node* addp2 = find_second_addp(use, raw_result);
1120             if (addp2 != NULL) {
1121               assert(alloc->is_AllocateArray(),"array allocation was expected");
1122               alloc_worklist.append_if_missing(addp2);
1123             }
1124             alloc_worklist.append_if_missing(use);
1125           } else if (use->is_MemBar()) {
1126             memnode_worklist.append_if_missing(use);
1127           }
1128         }
1129       }
1130     } else if (n->is_AddP()) {
1131       ptset.Clear();
1132       PointsTo(ptset, get_addp_base(n));
1133       assert(ptset.Size() == 1, "AddP address is unique");
1134       uint elem = ptset.getelem(); // Allocation node's index
1135       if (elem == _phantom_object) {
1136         assert(false, "escaped allocation");
1137         continue; // Assume the value was set outside this method.
1138       }
1139       Node *base = get_map(elem);  // CheckCastPP node
1140       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1141       tinst = igvn->type(base)->isa_oopptr();
1142     } else if (n->is_Phi() ||
1143                n->is_CheckCastPP() ||
1144                n->is_EncodeP() ||
1145                n->is_DecodeN() ||
1146                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1147       if (visited.test_set(n->_idx)) {
1148         assert(n->is_Phi(), "loops only through Phi's");
1149         continue;  // already processed
1150       }
1151       ptset.Clear();
1152       PointsTo(ptset, n);
1153       if (ptset.Size() == 1) {
1154         uint elem = ptset.getelem(); // Allocation node's index
1155         if (elem == _phantom_object) {
1156           assert(false, "escaped allocation");
1157           continue; // Assume the value was set outside this method.
1158         }
1159         Node *val = get_map(elem);   // CheckCastPP node
1160         TypeNode *tn = n->as_Type();
1161         tinst = igvn->type(val)->isa_oopptr();
1162         assert(tinst != NULL && tinst->is_known_instance() &&
1163                (uint)tinst->instance_id() == elem , "instance type expected.");
1164 
1165         const Type *tn_type = igvn->type(tn);
1166         const TypeOopPtr *tn_t;
1167         if (tn_type->isa_narrowoop()) {
1168           tn_t = tn_type->make_ptr()->isa_oopptr();
1169         } else {
1170           tn_t = tn_type->isa_oopptr();
1171         }
1172 
1173         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1174           if (tn_type->isa_narrowoop()) {
1175             tn_type = tinst->make_narrowoop();
1176           } else {
1177             tn_type = tinst;
1178           }
1179           igvn->hash_delete(tn);
1180           igvn->set_type(tn, tn_type);
1181           tn->set_type(tn_type);
1182           igvn->hash_insert(tn);
1183           record_for_optimizer(n);
1184         } else {
1185           assert(tn_type == TypePtr::NULL_PTR ||
1186                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
1187                  "unexpected type");
1188           continue; // Skip dead path with different type
1189         }
1190       }
1191     } else {
1192       debug_only(n->dump();)
1193       assert(false, "EA: unexpected node");
1194       continue;
1195     }
1196     // push allocation's users on appropriate worklist
1197     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1198       Node *use = n->fast_out(i);
1199       if(use->is_Mem() && use->in(MemNode::Address) == n) {
1200         // Load/store to instance's field
1201         memnode_worklist.append_if_missing(use);
1202       } else if (use->is_MemBar()) {
1203         memnode_worklist.append_if_missing(use);
1204       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
1205         Node* addp2 = find_second_addp(use, n);
1206         if (addp2 != NULL) {
1207           alloc_worklist.append_if_missing(addp2);
1208         }
1209         alloc_worklist.append_if_missing(use);
1210       } else if (use->is_Phi() ||
1211                  use->is_CheckCastPP() ||
1212                  use->is_EncodeP() ||
1213                  use->is_DecodeN() ||
1214                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
1215         alloc_worklist.append_if_missing(use);
1216 #ifdef ASSERT
1217       } else if (use->is_Mem()) {
1218         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
1219       } else if (use->is_MergeMem()) {
1220         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1221       } else if (use->is_SafePoint()) {
1222         // Look for MergeMem nodes for calls which reference unique allocation
1223         // (through CheckCastPP nodes) even for debug info.
1224         Node* m = use->in(TypeFunc::Memory);
1225         if (m->is_MergeMem()) {
1226           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1227         }
1228       } else {
1229         uint op = use->Opcode();
1230         if (!(op == Op_CmpP || op == Op_Conv2B ||
1231               op == Op_CastP2X || op == Op_StoreCM ||
1232               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1233               op == Op_StrEquals || op == Op_StrIndexOf)) {
1234           n->dump();
1235           use->dump();
1236           assert(false, "EA: missing allocation reference path");
1237         }
1238 #endif
1239       }
1240     }
1241 
1242   }
1243   // New alias types were created in split_AddP().
1244   uint new_index_end = (uint) _compile->num_alias_types();
1245 
1246   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
1247   //            compute new values for Memory inputs  (the Memory inputs are not
1248   //            actually updated until phase 4.)
1249   if (memnode_worklist.length() == 0)
1250     return;  // nothing to do
1251 
1252   while (memnode_worklist.length() != 0) {
1253     Node *n = memnode_worklist.pop();
1254     if (visited.test_set(n->_idx))
1255       continue;
1256     if (n->is_Phi() || n->is_ClearArray()) {
1257       // we don't need to do anything, but the users must be pushed
1258     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1259       // we don't need to do anything, but the users must be pushed
1260       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1261       if (n == NULL)
1262         continue;
1263     } else {
1264       assert(n->is_Mem(), "memory node required.");
1265       Node *addr = n->in(MemNode::Address);
1266       const Type *addr_t = igvn->type(addr);
1267       if (addr_t == Type::TOP)
1268         continue;
1269       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1270       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1271       assert ((uint)alias_idx < new_index_end, "wrong alias index");
1272       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1273       if (_compile->failing()) {
1274         return;
1275       }
1276       if (mem != n->in(MemNode::Memory)) {
1277         // We delay the memory edge update since we need old one in
1278         // MergeMem code below when instances memory slices are separated.
1279         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1280         assert(pn == NULL || pn == n, "wrong node");
1281         set_map(n->_idx, mem);
1282         ptnode_adr(n->_idx)->_node = n;
1283       }
1284       if (n->is_Load()) {
1285         continue;  // don't push users
1286       } else if (n->is_LoadStore()) {
1287         // get the memory projection
1288         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1289           Node *use = n->fast_out(i);
1290           if (use->Opcode() == Op_SCMemProj) {
1291             n = use;
1292             break;
1293           }
1294         }
1295         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1296       }
1297     }
1298     // push user on appropriate worklist
1299     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1300       Node *use = n->fast_out(i);
1301       if (use->is_Phi() || use->is_ClearArray()) {
1302         memnode_worklist.append_if_missing(use);
1303       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
1304         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
1305           continue;
1306         memnode_worklist.append_if_missing(use);
1307       } else if (use->is_MemBar()) {
1308         memnode_worklist.append_if_missing(use);
1309 #ifdef ASSERT
1310       } else if(use->is_Mem()) {
1311         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
1312       } else if (use->is_MergeMem()) {
1313         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1314       } else {
1315         uint op = use->Opcode();
1316         if (!(op == Op_StoreCM ||
1317               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
1318                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
1319               op == Op_AryEq || op == Op_StrComp ||
1320               op == Op_StrEquals || op == Op_StrIndexOf)) {
1321           n->dump();
1322           use->dump();
1323           assert(false, "EA: missing memory path");
1324         }
1325 #endif
1326       }
1327     }
1328   }
1329 
1330   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
1331   //            Walk each memory slice moving the first node encountered of each
1332   //            instance type to the the input corresponding to its alias index.
1333   uint length = _mergemem_worklist.length();
1334   for( uint next = 0; next < length; ++next ) {
1335     MergeMemNode* nmm = _mergemem_worklist.at(next);
1336     assert(!visited.test_set(nmm->_idx), "should not be visited before");
1337     // Note: we don't want to use MergeMemStream here because we only want to
1338     // scan inputs which exist at the start, not ones we add during processing.
1339     // Note 2: MergeMem may already contains instance memory slices added
1340     // during find_inst_mem() call when memory nodes were processed above.
1341     igvn->hash_delete(nmm);
1342     uint nslices = nmm->req();
1343     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
1344       Node* mem = nmm->in(i);
1345       Node* cur = NULL;
1346       if (mem == NULL || mem->is_top())
1347         continue;
1348       // First, update mergemem by moving memory nodes to corresponding slices
1349       // if their type became more precise since this mergemem was created.
1350       while (mem->is_Mem()) {
1351         const Type *at = igvn->type(mem->in(MemNode::Address));
1352         if (at != Type::TOP) {
1353           assert (at->isa_ptr() != NULL, "pointer type required.");
1354           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
1355           if (idx == i) {
1356             if (cur == NULL)
1357               cur = mem;
1358           } else {
1359             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
1360               nmm->set_memory_at(idx, mem);
1361             }
1362           }
1363         }
1364         mem = mem->in(MemNode::Memory);
1365       }
1366       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
1367       // Find any instance of the current type if we haven't encountered
1368       // already a memory slice of the instance along the memory chain.
1369       for (uint ni = new_index_start; ni < new_index_end; ni++) {
1370         if((uint)_compile->get_general_index(ni) == i) {
1371           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
1372           if (nmm->is_empty_memory(m)) {
1373             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
1374             if (_compile->failing()) {
1375               return;
1376             }
1377             nmm->set_memory_at(ni, result);
1378           }
1379         }
1380       }
1381     }
1382     // Find the rest of instances values
1383     for (uint ni = new_index_start; ni < new_index_end; ni++) {
1384       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
1385       Node* result = step_through_mergemem(nmm, ni, tinst);
1386       if (result == nmm->base_memory()) {
1387         // Didn't find instance memory, search through general slice recursively.
1388         result = nmm->memory_at(_compile->get_general_index(ni));
1389         result = find_inst_mem(result, ni, orig_phis, igvn);
1390         if (_compile->failing()) {
1391           return;
1392         }
1393         nmm->set_memory_at(ni, result);
1394       }
1395     }
1396     igvn->hash_insert(nmm);
1397     record_for_optimizer(nmm);
1398   }
1399 
1400   //  Phase 4:  Update the inputs of non-instance memory Phis and
1401   //            the Memory input of memnodes
1402   // First update the inputs of any non-instance Phi's from
1403   // which we split out an instance Phi.  Note we don't have
1404   // to recursively process Phi's encounted on the input memory
1405   // chains as is done in split_memory_phi() since they  will
1406   // also be processed here.
1407   for (int j = 0; j < orig_phis.length(); j++) {
1408     PhiNode *phi = orig_phis.at(j);
1409     int alias_idx = _compile->get_alias_index(phi->adr_type());
1410     igvn->hash_delete(phi);
1411     for (uint i = 1; i < phi->req(); i++) {
1412       Node *mem = phi->in(i);
1413       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
1414       if (_compile->failing()) {
1415         return;
1416       }
1417       if (mem != new_mem) {
1418         phi->set_req(i, new_mem);
1419       }
1420     }
1421     igvn->hash_insert(phi);
1422     record_for_optimizer(phi);
1423   }
1424 
1425   // Update the memory inputs of MemNodes with the value we computed
1426   // in Phase 2 and move stores memory users to corresponding memory slices.
1427 #ifdef ASSERT
1428   visited.Clear();
1429   Node_Stack old_mems(arena, _compile->unique() >> 2);
1430 #endif
1431   for (uint i = 0; i < nodes_size(); i++) {
1432     Node *nmem = get_map(i);
1433     if (nmem != NULL) {
1434       Node *n = ptnode_adr(i)->_node;
1435       assert(n != NULL, "sanity");
1436       if (n->is_Mem()) {
1437 #ifdef ASSERT
1438         Node* old_mem = n->in(MemNode::Memory);
1439         if (!visited.test_set(old_mem->_idx)) {
1440           old_mems.push(old_mem, old_mem->outcnt());
1441         }
1442 #endif
1443         assert(n->in(MemNode::Memory) != nmem, "sanity");
1444         if (!n->is_Load()) {
1445           // Move memory users of a store first.
1446           move_inst_mem(n, orig_phis, igvn);
1447         }
1448         // Now update memory input
1449         igvn->hash_delete(n);
1450         n->set_req(MemNode::Memory, nmem);
1451         igvn->hash_insert(n);
1452         record_for_optimizer(n);
1453       } else {
1454         assert(n->is_Allocate() || n->is_CheckCastPP() ||
1455                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1456       }
1457     }
1458   }
1459 #ifdef ASSERT
1460   // Verify that memory was split correctly
1461   while (old_mems.is_nonempty()) {
1462     Node* old_mem = old_mems.node();
1463     uint  old_cnt = old_mems.index();
1464     old_mems.pop();
1465     assert(old_cnt = old_mem->outcnt(), "old mem could be lost");
1466   }
1467 #endif
1468 }
1469 
1470 bool ConnectionGraph::has_candidates(Compile *C) {
1471   // EA brings benefits only when the code has allocations and/or locks which
1472   // are represented by ideal Macro nodes.
1473   int cnt = C->macro_count();
1474   for( int i=0; i < cnt; i++ ) {
1475     Node *n = C->macro_node(i);
1476     if ( n->is_Allocate() )
1477       return true;
1478     if( n->is_Lock() ) {
1479       Node* obj = n->as_Lock()->obj_node()->uncast();
1480       if( !(obj->is_Parm() || obj->is_Con()) )
1481         return true;
1482     }
1483   }
1484   return false;
1485 }
1486 
1487 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1488   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1489   // to create space for them in ConnectionGraph::_nodes[].
1490   Node* oop_null = igvn->zerocon(T_OBJECT);
1491   Node* noop_null = igvn->zerocon(T_NARROWOOP);
1492 
1493   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1494   // Perform escape analysis
1495   if (congraph->compute_escape()) {
1496     // There are non escaping objects.
1497     C->set_congraph(congraph);
1498   }
1499 
1500   // Cleanup.
1501   if (oop_null->outcnt() == 0)
1502     igvn->hash_delete(oop_null);
1503   if (noop_null->outcnt() == 0)
1504     igvn->hash_delete(noop_null);
1505 }
1506 
1507 bool ConnectionGraph::compute_escape() {
1508   Compile* C = _compile;
1509 
1510   // 1. Populate Connection Graph (CG) with Ideal nodes.
1511 
1512   Unique_Node_List worklist_init;
1513   worklist_init.map(C->unique(), NULL);  // preallocate space
1514 
1515   // Initialize worklist
1516   if (C->root() != NULL) {
1517     worklist_init.push(C->root());
1518   }
1519 
1520   GrowableArray<int> cg_worklist;
1521   PhaseGVN* igvn = _igvn;
1522   bool has_allocations = false;
1523 
1524   // Push all useful nodes onto CG list and set their type.
1525   for( uint next = 0; next < worklist_init.size(); ++next ) {
1526     Node* n = worklist_init.at(next);
1527     record_for_escape_analysis(n, igvn);
1528     // Only allocations and java static calls results are checked
1529     // for an escape status. See process_call_result() below.
1530     if (n->is_Allocate() || n->is_CallStaticJava() &&
1531         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1532       has_allocations = true;
1533     }
1534     if(n->is_AddP()) {
1535       // Collect address nodes. Use them during stage 3 below
1536       // to build initial connection graph field edges.
1537       cg_worklist.append(n->_idx);
1538     } else if (n->is_MergeMem()) {
1539       // Collect all MergeMem nodes to add memory slices for
1540       // scalar replaceable objects in split_unique_types().
1541       _mergemem_worklist.append(n->as_MergeMem());
1542     }
1543     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1544       Node* m = n->fast_out(i);   // Get user
1545       worklist_init.push(m);
1546     }
1547   }
1548 
1549   if (!has_allocations) {
1550     _collecting = false;
1551     return false; // Nothing to do.
1552   }
1553 
1554   // 2. First pass to create simple CG edges (doesn't require to walk CG).
1555   uint delayed_size = _delayed_worklist.size();
1556   for( uint next = 0; next < delayed_size; ++next ) {
1557     Node* n = _delayed_worklist.at(next);
1558     build_connection_graph(n, igvn);
1559   }
1560 
1561   // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
1562   //    to reduce number of iterations during stage 4 below.
1563   uint cg_length = cg_worklist.length();
1564   for( uint next = 0; next < cg_length; ++next ) {
1565     int ni = cg_worklist.at(next);
1566     Node* n = ptnode_adr(ni)->_node;
1567     Node* base = get_addp_base(n);
1568     if (base->is_Proj())
1569       base = base->in(0);
1570     PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
1571     if (nt == PointsToNode::JavaObject) {
1572       build_connection_graph(n, igvn);
1573     }
1574   }
1575 
1576   cg_worklist.clear();
1577   cg_worklist.append(_phantom_object);
1578 
1579   // 4. Build Connection Graph which need
1580   //    to walk the connection graph.
1581   _progress = false;
1582   for (uint ni = 0; ni < nodes_size(); ni++) {
1583     PointsToNode* ptn = ptnode_adr(ni);
1584     Node *n = ptn->_node;
1585     if (n != NULL) { // Call, AddP, LoadP, StoreP
1586       build_connection_graph(n, igvn);
1587       if (ptn->node_type() != PointsToNode::UnknownType)
1588         cg_worklist.append(n->_idx); // Collect CG nodes
1589     }
1590   }
1591   // After IGVN user nodes may have smaller _idx than
1592   // their inputs so they will be processed first in
1593   // previous loop. Because of that not all Graph
1594   // edges will be created. Walk over interesting
1595   // nodes again until no new edges are created.
1596   // Set limit on iterations.
1597   cg_length = cg_worklist.length();
1598   int iterations = 0;
1599   while(_progress && (iterations++ < 10)) {
1600     _progress = false;
1601     for( uint next = 0; next < cg_length; ++next ) {
1602       int ni = cg_worklist.at(next);
1603       PointsToNode* ptn = ptnode_adr(ni);
1604       DEBUG_ONLY(PointsToNode::NodeType nt = ptn->node_type());
1605       Node* n = ptn->_node;
1606       assert(n != NULL && nt != PointsToNode::UnknownType, "should be known node");
1607       build_connection_graph(n, igvn);
1608     }
1609   }
1610   if (iterations >= 10) {
1611     // Possible infinit build_connection_graph loop.
1612     // Retry compilation without escape analysis.
1613     C->record_failure(C2Compiler::retry_no_escape_analysis());
1614     _collecting = false;
1615     return false;
1616   }
1617 
1618   Arena* arena = Thread::current()->resource_area();
1619   VectorSet ptset(arena);
1620   GrowableArray<uint>  deferred_edges;
1621   VectorSet visited(arena);
1622 
1623   // 5. Remove deferred edges from the graph and adjust
1624   //    escape state of nonescaping objects.
1625   for( uint next = 0; next < cg_length; ++next ) {
1626     int ni = cg_worklist.at(next);
1627     PointsToNode* ptn = ptnode_adr(ni);
1628     PointsToNode::NodeType nt = ptn->node_type();
1629     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1630       remove_deferred(ni, &deferred_edges, &visited);
1631       Node *n = ptn->_node;
1632       if (n->is_AddP()) {
1633         // Search for objects which are not scalar replaceable
1634         // and adjust their escape state.
1635         verify_escape_state(ni, ptset, igvn);
1636       }
1637     }
1638   }
1639 
1640   // 6. Propagate escape states.
1641   GrowableArray<int>  worklist;
1642   bool has_non_escaping_obj = false;
1643 
1644   // push all GlobalEscape nodes on the worklist
1645   for( uint next = 0; next < cg_length; ++next ) {
1646     int nk = cg_worklist.at(next);
1647     if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
1648       worklist.push(nk);
1649   }
1650   // mark all nodes reachable from GlobalEscape nodes
1651   while(worklist.length() > 0) {
1652     PointsToNode* ptn = ptnode_adr(worklist.pop());
1653     uint e_cnt = ptn->edge_count();
1654     for (uint ei = 0; ei < e_cnt; ei++) {
1655       uint npi = ptn->edge_target(ei);
1656       PointsToNode *np = ptnode_adr(npi);
1657       if (np->escape_state() < PointsToNode::GlobalEscape) {
1658         np->set_escape_state(PointsToNode::GlobalEscape);
1659         worklist.push(npi);
1660       }
1661     }
1662   }
1663 
1664   // push all ArgEscape nodes on the worklist
1665   for( uint next = 0; next < cg_length; ++next ) {
1666     int nk = cg_worklist.at(next);
1667     if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
1668       worklist.push(nk);
1669   }
1670   // mark all nodes reachable from ArgEscape nodes
1671   while(worklist.length() > 0) {
1672     PointsToNode* ptn = ptnode_adr(worklist.pop());
1673     if (ptn->node_type() == PointsToNode::JavaObject)
1674       has_non_escaping_obj = true; // Non GlobalEscape
1675     uint e_cnt = ptn->edge_count();
1676     for (uint ei = 0; ei < e_cnt; ei++) {
1677       uint npi = ptn->edge_target(ei);
1678       PointsToNode *np = ptnode_adr(npi);
1679       if (np->escape_state() < PointsToNode::ArgEscape) {
1680         np->set_escape_state(PointsToNode::ArgEscape);
1681         worklist.push(npi);
1682       }
1683     }
1684   }
1685 
1686   GrowableArray<Node*> alloc_worklist;
1687 
1688   // push all NoEscape nodes on the worklist
1689   for( uint next = 0; next < cg_length; ++next ) {
1690     int nk = cg_worklist.at(next);
1691     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
1692       worklist.push(nk);
1693   }
1694   // mark all nodes reachable from NoEscape nodes
1695   while(worklist.length() > 0) {
1696     PointsToNode* ptn = ptnode_adr(worklist.pop());
1697     if (ptn->node_type() == PointsToNode::JavaObject)
1698       has_non_escaping_obj = true; // Non GlobalEscape
1699     Node* n = ptn->_node;
1700     if (n->is_Allocate() && ptn->_scalar_replaceable ) {
1701       // Push scalar replaceable allocations on alloc_worklist
1702       // for processing in split_unique_types().
1703       alloc_worklist.append(n);
1704     }
1705     uint e_cnt = ptn->edge_count();
1706     for (uint ei = 0; ei < e_cnt; ei++) {
1707       uint npi = ptn->edge_target(ei);
1708       PointsToNode *np = ptnode_adr(npi);
1709       if (np->escape_state() < PointsToNode::NoEscape) {
1710         np->set_escape_state(PointsToNode::NoEscape);
1711         worklist.push(npi);
1712       }
1713     }
1714   }
1715 
1716   _collecting = false;
1717   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1718 
1719 #ifndef PRODUCT
1720   if (PrintEscapeAnalysis) {
1721     dump(); // Dump ConnectionGraph
1722   }
1723 #endif
1724 
1725   bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
1726   if ( has_scalar_replaceable_candidates &&
1727        C->AliasLevel() >= 3 && EliminateAllocations ) {
1728 
1729     // Now use the escape information to create unique types for
1730     // scalar replaceable objects.
1731     split_unique_types(alloc_worklist);
1732 
1733     if (C->failing())  return false;
1734 
1735     C->print_method("After Escape Analysis", 2);
1736 
1737 #ifdef ASSERT
1738   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1739     tty->print("=== No allocations eliminated for ");
1740     C->method()->print_short_name();
1741     if(!EliminateAllocations) {
1742       tty->print(" since EliminateAllocations is off ===");
1743     } else if(!has_scalar_replaceable_candidates) {
1744       tty->print(" since there are no scalar replaceable candidates ===");
1745     } else if(C->AliasLevel() < 3) {
1746       tty->print(" since AliasLevel < 3 ===");
1747     }
1748     tty->cr();
1749 #endif
1750   }
1751   return has_non_escaping_obj;
1752 }
1753 
1754 // Search for objects which are not scalar replaceable.
1755 void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
1756   PointsToNode* ptn = ptnode_adr(nidx);
1757   Node* n = ptn->_node;
1758   assert(n->is_AddP(), "Should be called for AddP nodes only");
1759   // Search for objects which are not scalar replaceable.
1760   // Mark their escape state as ArgEscape to propagate the state
1761   // to referenced objects.
1762   // Note: currently there are no difference in compiler optimizations
1763   // for ArgEscape objects and NoEscape objects which are not
1764   // scalar replaceable.
1765 
1766   Compile* C = _compile;
1767 
1768   int offset = ptn->offset();
1769   Node* base = get_addp_base(n);
1770   ptset.Clear();
1771   PointsTo(ptset, base);
1772   int ptset_size = ptset.Size();
1773 
1774   // Check if a oop field's initializing value is recorded and add
1775   // a corresponding NULL field's value if it is not recorded.
1776   // Connection Graph does not record a default initialization by NULL
1777   // captured by Initialize node.
1778   //
1779   // Note: it will disable scalar replacement in some cases:
1780   //
1781   //    Point p[] = new Point[1];
1782   //    p[0] = new Point(); // Will be not scalar replaced
1783   //
1784   // but it will save us from incorrect optimizations in next cases:
1785   //
1786   //    Point p[] = new Point[1];
1787   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
1788   //
1789   // Do a simple control flow analysis to distinguish above cases.
1790   //
1791   if (offset != Type::OffsetBot && ptset_size == 1) {
1792     uint elem = ptset.getelem(); // Allocation node's index
1793     // It does not matter if it is not Allocation node since
1794     // only non-escaping allocations are scalar replaced.
1795     if (ptnode_adr(elem)->_node->is_Allocate() &&
1796         ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
1797       AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
1798       InitializeNode* ini = alloc->initialization();
1799 
1800       // Check only oop fields.
1801       const Type* adr_type = n->as_AddP()->bottom_type();
1802       BasicType basic_field_type = T_INT;
1803       if (adr_type->isa_instptr()) {
1804         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
1805         if (field != NULL) {
1806           basic_field_type = field->layout_type();
1807         } else {
1808           // Ignore non field load (for example, klass load)
1809         }
1810       } else if (adr_type->isa_aryptr()) {
1811         const Type* elemtype = adr_type->isa_aryptr()->elem();
1812         basic_field_type = elemtype->array_element_basic_type();
1813       } else {
1814         // Raw pointers are used for initializing stores so skip it.
1815         assert(adr_type->isa_rawptr() && base->is_Proj() &&
1816                (base->in(0) == alloc),"unexpected pointer type");
1817       }
1818       if (basic_field_type == T_OBJECT ||
1819           basic_field_type == T_NARROWOOP ||
1820           basic_field_type == T_ARRAY) {
1821         Node* value = NULL;
1822         if (ini != NULL) {
1823           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
1824           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
1825           if (store != NULL && store->is_Store()) {
1826             value = store->in(MemNode::ValueIn);
1827           } else if (ptn->edge_count() > 0) { // Are there oop stores?
1828             // Check for a store which follows allocation without branches.
1829             // For example, a volatile field store is not collected
1830             // by Initialize node. TODO: it would be nice to use idom() here.
1831             for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1832               store = n->fast_out(i);
1833               if (store->is_Store() && store->in(0) != NULL) {
1834                 Node* ctrl = store->in(0);
1835                 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
1836                         ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
1837                         ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
1838                    ctrl = ctrl->in(0);
1839                 }
1840                 if (ctrl == ini || ctrl == alloc) {
1841                   value = store->in(MemNode::ValueIn);
1842                   break;
1843                 }
1844               }
1845             }
1846           }
1847         }
1848         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
1849           // A field's initializing value was not recorded. Add NULL.
1850           uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1851           add_pointsto_edge(nidx, null_idx);
1852         }
1853       }
1854     }
1855   }
1856 
1857   // An object is not scalar replaceable if the field which may point
1858   // to it has unknown offset (unknown element of an array of objects).
1859   //
1860   if (offset == Type::OffsetBot) {
1861     uint e_cnt = ptn->edge_count();
1862     for (uint ei = 0; ei < e_cnt; ei++) {
1863       uint npi = ptn->edge_target(ei);
1864       set_escape_state(npi, PointsToNode::ArgEscape);
1865       ptnode_adr(npi)->_scalar_replaceable = false;
1866     }
1867   }
1868 
1869   // Currently an object is not scalar replaceable if a LoadStore node
1870   // access its field since the field value is unknown after it.
1871   //
1872   bool has_LoadStore = false;
1873   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1874     Node *use = n->fast_out(i);
1875     if (use->is_LoadStore()) {
1876       has_LoadStore = true;
1877       break;
1878     }
1879   }
1880   // An object is not scalar replaceable if the address points
1881   // to unknown field (unknown element for arrays, offset is OffsetBot).
1882   //
1883   // Or the address may point to more then one object. This may produce
1884   // the false positive result (set scalar_replaceable to false)
1885   // since the flow-insensitive escape analysis can't separate
1886   // the case when stores overwrite the field's value from the case
1887   // when stores happened on different control branches.
1888   //
1889   if (ptset_size > 1 || ptset_size != 0 &&
1890       (has_LoadStore || offset == Type::OffsetBot)) {
1891     for( VectorSetI j(&ptset); j.test(); ++j ) {
1892       set_escape_state(j.elem, PointsToNode::ArgEscape);
1893       ptnode_adr(j.elem)->_scalar_replaceable = false;
1894     }
1895   }
1896 }
1897 
1898 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
1899 
1900     switch (call->Opcode()) {
1901 #ifdef ASSERT
1902     case Op_Allocate:
1903     case Op_AllocateArray:
1904     case Op_Lock:
1905     case Op_Unlock:
1906       assert(false, "should be done already");
1907       break;
1908 #endif
1909     case Op_CallLeaf:
1910     case Op_CallLeafNoFP:
1911     {
1912       // Stub calls, objects do not escape but they are not scale replaceable.
1913       // Adjust escape state for outgoing arguments.
1914       const TypeTuple * d = call->tf()->domain();
1915       VectorSet ptset(Thread::current()->resource_area());
1916       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1917         const Type* at = d->field_at(i);
1918         Node *arg = call->in(i)->uncast();
1919         const Type *aat = phase->type(arg);
1920         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
1921             ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
1922 
1923           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
1924                  aat->isa_ptr() != NULL, "expecting an Ptr");
1925 #ifdef ASSERT
1926           if (!(call->Opcode() == Op_CallLeafNoFP &&
1927                 call->as_CallLeaf()->_name != NULL &&
1928                 (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
1929                 call->as_CallLeaf()->_name != NULL &&
1930                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
1931                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
1932           ) {
1933             call->dump();
1934             assert(false, "EA: unexpected CallLeaf");
1935           }
1936 #endif
1937           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1938           if (arg->is_AddP()) {
1939             //
1940             // The inline_native_clone() case when the arraycopy stub is called
1941             // after the allocation before Initialize and CheckCastPP nodes.
1942             //
1943             // Set AddP's base (Allocate) as not scalar replaceable since
1944             // pointer to the base (with offset) is passed as argument.
1945             //
1946             arg = get_addp_base(arg);
1947           }
1948           ptset.Clear();
1949           PointsTo(ptset, arg);
1950           for( VectorSetI j(&ptset); j.test(); ++j ) {
1951             uint pt = j.elem;
1952             set_escape_state(pt, PointsToNode::ArgEscape);
1953           }
1954         }
1955       }
1956       break;
1957     }
1958 
1959     case Op_CallStaticJava:
1960     // For a static call, we know exactly what method is being called.
1961     // Use bytecode estimator to record the call's escape affects
1962     {
1963       ciMethod *meth = call->as_CallJava()->method();
1964       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
1965       // fall-through if not a Java method or no analyzer information
1966       if (call_analyzer != NULL) {
1967         const TypeTuple * d = call->tf()->domain();
1968         VectorSet ptset(Thread::current()->resource_area());
1969         bool copy_dependencies = false;
1970         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
1971           const Type* at = d->field_at(i);
1972           int k = i - TypeFunc::Parms;
1973           Node *arg = call->in(i)->uncast();
1974 
1975           if (at->isa_oopptr() != NULL &&
1976               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
1977 
1978             bool global_escapes = false;
1979             bool fields_escapes = false;
1980             if (!call_analyzer->is_arg_stack(k)) {
1981               // The argument global escapes, mark everything it could point to
1982               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
1983               global_escapes = true;
1984             } else {
1985               if (!call_analyzer->is_arg_local(k)) {
1986                 // The argument itself doesn't escape, but any fields might
1987                 fields_escapes = true;
1988               }
1989               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
1990               copy_dependencies = true;
1991             }
1992 
1993             ptset.Clear();
1994             PointsTo(ptset, arg);
1995             for( VectorSetI j(&ptset); j.test(); ++j ) {
1996               uint pt = j.elem;
1997               if (global_escapes) {
1998                 //The argument global escapes, mark everything it could point to
1999                 set_escape_state(pt, PointsToNode::GlobalEscape);
2000               } else {
2001                 if (fields_escapes) {
2002                   // The argument itself doesn't escape, but any fields might
2003                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2004                 }
2005                 set_escape_state(pt, PointsToNode::ArgEscape);
2006               }
2007             }
2008           }
2009         }
2010         if (copy_dependencies)
2011           call_analyzer->copy_dependencies(_compile->dependencies());
2012         break;
2013       }
2014     }
2015 
2016     default:
2017     // Fall-through here if not a Java method or no analyzer information
2018     // or some other type of call, assume the worst case: all arguments
2019     // globally escape.
2020     {
2021       // adjust escape state for  outgoing arguments
2022       const TypeTuple * d = call->tf()->domain();
2023       VectorSet ptset(Thread::current()->resource_area());
2024       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2025         const Type* at = d->field_at(i);
2026         if (at->isa_oopptr() != NULL) {
2027           Node *arg = call->in(i)->uncast();
2028           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2029           ptset.Clear();
2030           PointsTo(ptset, arg);
2031           for( VectorSetI j(&ptset); j.test(); ++j ) {
2032             uint pt = j.elem;
2033             set_escape_state(pt, PointsToNode::GlobalEscape);
2034           }
2035         }
2036       }
2037     }
2038   }
2039 }
2040 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
2041   CallNode   *call = resproj->in(0)->as_Call();
2042   uint    call_idx = call->_idx;
2043   uint resproj_idx = resproj->_idx;
2044 
2045   switch (call->Opcode()) {
2046     case Op_Allocate:
2047     {
2048       Node *k = call->in(AllocateNode::KlassNode);
2049       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2050       assert(kt != NULL, "TypeKlassPtr  required.");
2051       ciKlass* cik = kt->klass();
2052 
2053       PointsToNode::EscapeState es;
2054       uint edge_to;
2055       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2056          !cik->is_instance_klass() || // StressReflectiveCode
2057           cik->as_instance_klass()->has_finalizer()) {
2058         es = PointsToNode::GlobalEscape;
2059         edge_to = _phantom_object; // Could not be worse
2060       } else {
2061         es = PointsToNode::NoEscape;
2062         edge_to = call_idx;
2063       }
2064       set_escape_state(call_idx, es);
2065       add_pointsto_edge(resproj_idx, edge_to);
2066       _processed.set(resproj_idx);
2067       break;
2068     }
2069 
2070     case Op_AllocateArray:
2071     {
2072 
2073       Node *k = call->in(AllocateNode::KlassNode);
2074       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2075       assert(kt != NULL, "TypeKlassPtr  required.");
2076       ciKlass* cik = kt->klass();
2077 
2078       PointsToNode::EscapeState es;
2079       uint edge_to;
2080       if (!cik->is_array_klass()) { // StressReflectiveCode
2081         es = PointsToNode::GlobalEscape;
2082         edge_to = _phantom_object;
2083       } else {
2084         es = PointsToNode::NoEscape;
2085         edge_to = call_idx;
2086         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2087         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2088           // Not scalar replaceable if the length is not constant or too big.
2089           ptnode_adr(call_idx)->_scalar_replaceable = false;
2090         }
2091       }
2092       set_escape_state(call_idx, es);
2093       add_pointsto_edge(resproj_idx, edge_to);
2094       _processed.set(resproj_idx);
2095       break;
2096     }
2097 
2098     case Op_CallStaticJava:
2099     // For a static call, we know exactly what method is being called.
2100     // Use bytecode estimator to record whether the call's return value escapes
2101     {
2102       bool done = true;
2103       const TypeTuple *r = call->tf()->range();
2104       const Type* ret_type = NULL;
2105 
2106       if (r->cnt() > TypeFunc::Parms)
2107         ret_type = r->field_at(TypeFunc::Parms);
2108 
2109       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
2110       //        _multianewarray functions return a TypeRawPtr.
2111       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2112         _processed.set(resproj_idx);
2113         break;  // doesn't return a pointer type
2114       }
2115       ciMethod *meth = call->as_CallJava()->method();
2116       const TypeTuple * d = call->tf()->domain();
2117       if (meth == NULL) {
2118         // not a Java method, assume global escape
2119         set_escape_state(call_idx, PointsToNode::GlobalEscape);
2120         add_pointsto_edge(resproj_idx, _phantom_object);
2121       } else {
2122         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2123         bool copy_dependencies = false;
2124 
2125         if (call_analyzer->is_return_allocated()) {
2126           // Returns a newly allocated unescaped object, simply
2127           // update dependency information.
2128           // Mark it as NoEscape so that objects referenced by
2129           // it's fields will be marked as NoEscape at least.
2130           set_escape_state(call_idx, PointsToNode::NoEscape);
2131           add_pointsto_edge(resproj_idx, call_idx);
2132           copy_dependencies = true;
2133         } else if (call_analyzer->is_return_local()) {
2134           // determine whether any arguments are returned
2135           set_escape_state(call_idx, PointsToNode::NoEscape);
2136           bool ret_arg = false;
2137           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2138             const Type* at = d->field_at(i);
2139 
2140             if (at->isa_oopptr() != NULL) {
2141               Node *arg = call->in(i)->uncast();
2142 
2143               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2144                 ret_arg = true;
2145                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2146                 if (arg_esp->node_type() == PointsToNode::UnknownType)
2147                   done = false;
2148                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
2149                   add_pointsto_edge(resproj_idx, arg->_idx);
2150                 else
2151                   add_deferred_edge(resproj_idx, arg->_idx);
2152                 arg_esp->_hidden_alias = true;
2153               }
2154             }
2155           }
2156           if (done && !ret_arg) {
2157             // Returns unknown object.
2158             set_escape_state(call_idx, PointsToNode::GlobalEscape);
2159             add_pointsto_edge(resproj_idx, _phantom_object);
2160           }
2161           copy_dependencies = true;
2162         } else {
2163           set_escape_state(call_idx, PointsToNode::GlobalEscape);
2164           add_pointsto_edge(resproj_idx, _phantom_object);
2165           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2166             const Type* at = d->field_at(i);
2167             if (at->isa_oopptr() != NULL) {
2168               Node *arg = call->in(i)->uncast();
2169               PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2170               arg_esp->_hidden_alias = true;
2171             }
2172           }
2173         }
2174         if (copy_dependencies)
2175           call_analyzer->copy_dependencies(_compile->dependencies());
2176       }
2177       if (done)
2178         _processed.set(resproj_idx);
2179       break;
2180     }
2181 
2182     default:
2183     // Some other type of call, assume the worst case that the
2184     // returned value, if any, globally escapes.
2185     {
2186       const TypeTuple *r = call->tf()->range();
2187       if (r->cnt() > TypeFunc::Parms) {
2188         const Type* ret_type = r->field_at(TypeFunc::Parms);
2189 
2190         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
2191         //        _multianewarray functions return a TypeRawPtr.
2192         if (ret_type->isa_ptr() != NULL) {
2193           set_escape_state(call_idx, PointsToNode::GlobalEscape);
2194           add_pointsto_edge(resproj_idx, _phantom_object);
2195         }
2196       }
2197       _processed.set(resproj_idx);
2198     }
2199   }
2200 }
2201 
2202 // Populate Connection Graph with Ideal nodes and create simple
2203 // connection graph edges (do not need to check the node_type of inputs
2204 // or to call PointsTo() to walk the connection graph).
2205 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2206   if (_processed.test(n->_idx))
2207     return; // No need to redefine node's state.
2208 
2209   if (n->is_Call()) {
2210     // Arguments to allocation and locking don't escape.
2211     if (n->is_Allocate()) {
2212       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2213       record_for_optimizer(n);
2214     } else if (n->is_Lock() || n->is_Unlock()) {
2215       // Put Lock and Unlock nodes on IGVN worklist to process them during
2216       // the first IGVN optimization when escape information is still available.
2217       record_for_optimizer(n);
2218       _processed.set(n->_idx);
2219     } else {
2220       // Don't mark as processed since call's arguments have to be processed.
2221       PointsToNode::NodeType nt = PointsToNode::UnknownType;
2222       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2223 
2224       // Check if a call returns an object.
2225       const TypeTuple *r = n->as_Call()->tf()->range();
2226       if (r->cnt() > TypeFunc::Parms &&
2227           r->field_at(TypeFunc::Parms)->isa_ptr() &&
2228           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2229         nt = PointsToNode::JavaObject;
2230         if (!n->is_CallStaticJava()) {
2231           // Since the called mathod is statically unknown assume
2232           // the worst case that the returned value globally escapes.
2233           es = PointsToNode::GlobalEscape;
2234         }
2235       }
2236       add_node(n, nt, es, false);
2237     }
2238     return;
2239   }
2240 
2241   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2242   // ThreadLocal has RawPrt type.
2243   switch (n->Opcode()) {
2244     case Op_AddP:
2245     {
2246       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
2247       break;
2248     }
2249     case Op_CastX2P:
2250     { // "Unsafe" memory access.
2251       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2252       break;
2253     }
2254     case Op_CastPP:
2255     case Op_CheckCastPP:
2256     case Op_EncodeP:
2257     case Op_DecodeN:
2258     {
2259       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2260       int ti = n->in(1)->_idx;
2261       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2262       if (nt == PointsToNode::UnknownType) {
2263         _delayed_worklist.push(n); // Process it later.
2264         break;
2265       } else if (nt == PointsToNode::JavaObject) {
2266         add_pointsto_edge(n->_idx, ti);
2267       } else {
2268         add_deferred_edge(n->_idx, ti);
2269       }
2270       _processed.set(n->_idx);
2271       break;
2272     }
2273     case Op_ConP:
2274     {
2275       // assume all pointer constants globally escape except for null
2276       PointsToNode::EscapeState es;
2277       if (phase->type(n) == TypePtr::NULL_PTR)
2278         es = PointsToNode::NoEscape;
2279       else
2280         es = PointsToNode::GlobalEscape;
2281 
2282       add_node(n, PointsToNode::JavaObject, es, true);
2283       break;
2284     }
2285     case Op_ConN:
2286     {
2287       // assume all narrow oop constants globally escape except for null
2288       PointsToNode::EscapeState es;
2289       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2290         es = PointsToNode::NoEscape;
2291       else
2292         es = PointsToNode::GlobalEscape;
2293 
2294       add_node(n, PointsToNode::JavaObject, es, true);
2295       break;
2296     }
2297     case Op_CreateEx:
2298     {
2299       // assume that all exception objects globally escape
2300       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2301       break;
2302     }
2303     case Op_LoadKlass:
2304     case Op_LoadNKlass:
2305     {
2306       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2307       break;
2308     }
2309     case Op_LoadP:
2310     case Op_LoadN:
2311     {
2312       const Type *t = phase->type(n);
2313       if (t->make_ptr() == NULL) {
2314         _processed.set(n->_idx);
2315         return;
2316       }
2317       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2318       break;
2319     }
2320     case Op_Parm:
2321     {
2322       _processed.set(n->_idx); // No need to redefine it state.
2323       uint con = n->as_Proj()->_con;
2324       if (con < TypeFunc::Parms)
2325         return;
2326       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2327       if (t->isa_ptr() == NULL)
2328         return;
2329       // We have to assume all input parameters globally escape
2330       // (Note: passing 'false' since _processed is already set).
2331       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2332       break;
2333     }
2334     case Op_Phi:
2335     {
2336       const Type *t = n->as_Phi()->type();
2337       if (t->make_ptr() == NULL) {
2338         // nothing to do if not an oop or narrow oop
2339         _processed.set(n->_idx);
2340         return;
2341       }
2342       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2343       uint i;
2344       for (i = 1; i < n->req() ; i++) {
2345         Node* in = n->in(i);
2346         if (in == NULL)
2347           continue;  // ignore NULL
2348         in = in->uncast();
2349         if (in->is_top() || in == n)
2350           continue;  // ignore top or inputs which go back this node
2351         int ti = in->_idx;
2352         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2353         if (nt == PointsToNode::UnknownType) {
2354           break;
2355         } else if (nt == PointsToNode::JavaObject) {
2356           add_pointsto_edge(n->_idx, ti);
2357         } else {
2358           add_deferred_edge(n->_idx, ti);
2359         }
2360       }
2361       if (i >= n->req())
2362         _processed.set(n->_idx);
2363       else
2364         _delayed_worklist.push(n);
2365       break;
2366     }
2367     case Op_Proj:
2368     {
2369       // we are only interested in the oop result projection from a call
2370       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2371         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2372         assert(r->cnt() > TypeFunc::Parms, "sanity");
2373         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2374           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2375           int ti = n->in(0)->_idx;
2376           // The call may not be registered yet (since not all its inputs are registered)
2377           // if this is the projection from backbranch edge of Phi.
2378           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2379             process_call_result(n->as_Proj(), phase);
2380           }
2381           if (!_processed.test(n->_idx)) {
2382             // The call's result may need to be processed later if the call
2383             // returns it's argument and the argument is not processed yet.
2384             _delayed_worklist.push(n);
2385           }
2386           break;
2387         }
2388       }
2389       _processed.set(n->_idx);
2390       break;
2391     }
2392     case Op_Return:
2393     {
2394       if( n->req() > TypeFunc::Parms &&
2395           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2396         // Treat Return value as LocalVar with GlobalEscape escape state.
2397         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2398         int ti = n->in(TypeFunc::Parms)->_idx;
2399         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2400         if (nt == PointsToNode::UnknownType) {
2401           _delayed_worklist.push(n); // Process it later.
2402           break;
2403         } else if (nt == PointsToNode::JavaObject) {
2404           add_pointsto_edge(n->_idx, ti);
2405         } else {
2406           add_deferred_edge(n->_idx, ti);
2407         }
2408       }
2409       _processed.set(n->_idx);
2410       break;
2411     }
2412     case Op_StoreP:
2413     case Op_StoreN:
2414     {
2415       const Type *adr_type = phase->type(n->in(MemNode::Address));
2416       adr_type = adr_type->make_ptr();
2417       if (adr_type->isa_oopptr()) {
2418         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2419       } else {
2420         Node* adr = n->in(MemNode::Address);
2421         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2422             adr->in(AddPNode::Address)->is_Proj() &&
2423             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2424           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2425           // We are computing a raw address for a store captured
2426           // by an Initialize compute an appropriate address type.
2427           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2428           assert(offs != Type::OffsetBot, "offset must be a constant");
2429         } else {
2430           _processed.set(n->_idx);
2431           return;
2432         }
2433       }
2434       break;
2435     }
2436     case Op_StorePConditional:
2437     case Op_CompareAndSwapP:
2438     case Op_CompareAndSwapN:
2439     {
2440       const Type *adr_type = phase->type(n->in(MemNode::Address));
2441       adr_type = adr_type->make_ptr();
2442       if (adr_type->isa_oopptr()) {
2443         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2444       } else {
2445         _processed.set(n->_idx);
2446         return;
2447       }
2448       break;
2449     }
2450     case Op_AryEq:
2451     case Op_StrComp:
2452     case Op_StrEquals:
2453     case Op_StrIndexOf:
2454     {
2455       // char[] arrays passed to string intrinsics are not scalar replaceable.
2456       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2457       break;
2458     }
2459     case Op_ThreadLocal:
2460     {
2461       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2462       break;
2463     }
2464     default:
2465       ;
2466       // nothing to do
2467   }
2468   return;
2469 }
2470 
2471 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2472   uint n_idx = n->_idx;
2473   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2474 
2475   // Don't set processed bit for AddP, LoadP, StoreP since
2476   // they may need more then one pass to process.
2477   if (_processed.test(n_idx))
2478     return; // No need to redefine node's state.
2479 
2480   if (n->is_Call()) {
2481     CallNode *call = n->as_Call();
2482     process_call_arguments(call, phase);
2483     _processed.set(n_idx);
2484     return;
2485   }
2486 
2487   switch (n->Opcode()) {
2488     case Op_AddP:
2489     {
2490       Node *base = get_addp_base(n);
2491       // Create a field edge to this node from everything base could point to.
2492       VectorSet ptset(Thread::current()->resource_area());
2493       PointsTo(ptset, base);
2494       for( VectorSetI i(&ptset); i.test(); ++i ) {
2495         uint pt = i.elem;
2496         add_field_edge(pt, n_idx, address_offset(n, phase));
2497       }
2498       break;
2499     }
2500     case Op_CastX2P:
2501     {
2502       assert(false, "Op_CastX2P");
2503       break;
2504     }
2505     case Op_CastPP:
2506     case Op_CheckCastPP:
2507     case Op_EncodeP:
2508     case Op_DecodeN:
2509     {
2510       int ti = n->in(1)->_idx;
2511       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2512       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2513         add_pointsto_edge(n_idx, ti);
2514       } else {
2515         add_deferred_edge(n_idx, ti);
2516       }
2517       _processed.set(n_idx);
2518       break;
2519     }
2520     case Op_ConP:
2521     {
2522       assert(false, "Op_ConP");
2523       break;
2524     }
2525     case Op_ConN:
2526     {
2527       assert(false, "Op_ConN");
2528       break;
2529     }
2530     case Op_CreateEx:
2531     {
2532       assert(false, "Op_CreateEx");
2533       break;
2534     }
2535     case Op_LoadKlass:
2536     case Op_LoadNKlass:
2537     {
2538       assert(false, "Op_LoadKlass");
2539       break;
2540     }
2541     case Op_LoadP:
2542     case Op_LoadN:
2543     {
2544       const Type *t = phase->type(n);
2545 #ifdef ASSERT
2546       if (t->make_ptr() == NULL)
2547         assert(false, "Op_LoadP");
2548 #endif
2549 
2550       Node* adr = n->in(MemNode::Address)->uncast();
2551       Node* adr_base;
2552       if (adr->is_AddP()) {
2553         adr_base = get_addp_base(adr);
2554       } else {
2555         adr_base = adr;
2556       }
2557 
2558       // For everything "adr_base" could point to, create a deferred edge from
2559       // this node to each field with the same offset.
2560       VectorSet ptset(Thread::current()->resource_area());
2561       PointsTo(ptset, adr_base);
2562       int offset = address_offset(adr, phase);
2563       for( VectorSetI i(&ptset); i.test(); ++i ) {
2564         uint pt = i.elem;
2565         add_deferred_edge_to_fields(n_idx, pt, offset);
2566       }
2567       break;
2568     }
2569     case Op_Parm:
2570     {
2571       assert(false, "Op_Parm");
2572       break;
2573     }
2574     case Op_Phi:
2575     {
2576 #ifdef ASSERT
2577       const Type *t = n->as_Phi()->type();
2578       if (t->make_ptr() == NULL)
2579         assert(false, "Op_Phi");
2580 #endif
2581       for (uint i = 1; i < n->req() ; i++) {
2582         Node* in = n->in(i);
2583         if (in == NULL)
2584           continue;  // ignore NULL
2585         in = in->uncast();
2586         if (in->is_top() || in == n)
2587           continue;  // ignore top or inputs which go back this node
2588         int ti = in->_idx;
2589         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2590         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2591         if (nt == PointsToNode::JavaObject) {
2592           add_pointsto_edge(n_idx, ti);
2593         } else {
2594           add_deferred_edge(n_idx, ti);
2595         }
2596       }
2597       _processed.set(n_idx);
2598       break;
2599     }
2600     case Op_Proj:
2601     {
2602       // we are only interested in the oop result projection from a call
2603       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2604         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
2605                "all nodes should be registered");
2606         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2607         assert(r->cnt() > TypeFunc::Parms, "sanity");
2608         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2609           process_call_result(n->as_Proj(), phase);
2610           assert(_processed.test(n_idx), "all call results should be processed");
2611           break;
2612         }
2613       }
2614       assert(false, "Op_Proj");
2615       break;
2616     }
2617     case Op_Return:
2618     {
2619 #ifdef ASSERT
2620       if( n->req() <= TypeFunc::Parms ||
2621           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2622         assert(false, "Op_Return");
2623       }
2624 #endif
2625       int ti = n->in(TypeFunc::Parms)->_idx;
2626       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
2627       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2628         add_pointsto_edge(n_idx, ti);
2629       } else {
2630         add_deferred_edge(n_idx, ti);
2631       }
2632       _processed.set(n_idx);
2633       break;
2634     }
2635     case Op_StoreP:
2636     case Op_StoreN:
2637     case Op_StorePConditional:
2638     case Op_CompareAndSwapP:
2639     case Op_CompareAndSwapN:
2640     {
2641       Node *adr = n->in(MemNode::Address);
2642       const Type *adr_type = phase->type(adr)->make_ptr();
2643 #ifdef ASSERT
2644       if (!adr_type->isa_oopptr())
2645         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
2646 #endif
2647 
2648       assert(adr->is_AddP(), "expecting an AddP");
2649       Node *adr_base = get_addp_base(adr);
2650       Node *val = n->in(MemNode::ValueIn)->uncast();
2651       // For everything "adr_base" could point to, create a deferred edge
2652       // to "val" from each field with the same offset.
2653       VectorSet ptset(Thread::current()->resource_area());
2654       PointsTo(ptset, adr_base);
2655       for( VectorSetI i(&ptset); i.test(); ++i ) {
2656         uint pt = i.elem;
2657         add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
2658       }
2659       break;
2660     }
2661     case Op_AryEq:
2662     case Op_StrComp:
2663     case Op_StrEquals:
2664     case Op_StrIndexOf:
2665     {
2666       // char[] arrays passed to string intrinsic do not escape but
2667       // they are not scalar replaceable. Adjust escape state for them.
2668       // Start from in(2) edge since in(1) is memory edge.
2669       for (uint i = 2; i < n->req(); i++) {
2670         Node* adr = n->in(i)->uncast();
2671         const Type *at = phase->type(adr);
2672         if (!adr->is_top() && at->isa_ptr()) {
2673           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
2674                  at->isa_ptr() != NULL, "expecting an Ptr");
2675           if (adr->is_AddP()) {
2676             adr = get_addp_base(adr);
2677           }
2678           // Mark as ArgEscape everything "adr" could point to.
2679           set_escape_state(adr->_idx, PointsToNode::ArgEscape);
2680         }
2681       }
2682       _processed.set(n_idx);
2683       break;
2684     }
2685     case Op_ThreadLocal:
2686     {
2687       assert(false, "Op_ThreadLocal");
2688       break;
2689     }
2690     default:
2691       // This method should be called only for EA specific nodes.
2692       ShouldNotReachHere();
2693   }
2694 }
2695 
2696 #ifndef PRODUCT
2697 void ConnectionGraph::dump() {
2698   bool first = true;
2699 
2700   uint size = nodes_size();
2701   for (uint ni = 0; ni < size; ni++) {
2702     PointsToNode *ptn = ptnode_adr(ni);
2703     PointsToNode::NodeType ptn_type = ptn->node_type();
2704 
2705     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
2706       continue;
2707     PointsToNode::EscapeState es = escape_state(ptn->_node);
2708     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
2709       if (first) {
2710         tty->cr();
2711         tty->print("======== Connection graph for ");
2712         _compile->method()->print_short_name();
2713         tty->cr();
2714         first = false;
2715       }
2716       tty->print("%6d ", ni);
2717       ptn->dump();
2718       // Print all locals which reference this allocation
2719       for (uint li = ni; li < size; li++) {
2720         PointsToNode *ptn_loc = ptnode_adr(li);
2721         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
2722         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
2723              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
2724           ptnode_adr(li)->dump(false);
2725         }
2726       }
2727       if (Verbose) {
2728         // Print all fields which reference this allocation
2729         for (uint i = 0; i < ptn->edge_count(); i++) {
2730           uint ei = ptn->edge_target(i);
2731           ptnode_adr(ei)->dump(false);
2732         }
2733       }
2734       tty->cr();
2735     }
2736   }
2737 }
2738 #endif