src/share/vm/opto/escape.cpp
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src/share/vm/opto/escape.cpp

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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/bcEscapeAnalyzer.hpp"
  27 #include "libadt/vectset.hpp"
  28 #include "memory/allocation.hpp"
  29 #include "opto/c2compiler.hpp"
  30 #include "opto/callnode.hpp"
  31 #include "opto/cfgnode.hpp"
  32 #include "opto/compile.hpp"
  33 #include "opto/escape.hpp"
  34 #include "opto/phaseX.hpp"
  35 #include "opto/rootnode.hpp"
  36 
  37 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
  38   uint v = (targIdx << EdgeShift) + ((uint) et);
  39   if (_edges == NULL) {
  40      Arena *a = Compile::current()->comp_arena();
  41     _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
  42   }
  43   _edges->append_if_missing(v);
  44 }
  45 
  46 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
  47   uint v = (targIdx << EdgeShift) + ((uint) et);
  48 
  49   _edges->remove(v);
  50 }
  51 
  52 #ifndef PRODUCT
  53 static const char *node_type_names[] = {
  54   "UnknownType",
  55   "JavaObject",
  56   "LocalVar",
  57   "Field"
  58 };
  59 
  60 static const char *esc_names[] = {
  61   "UnknownEscape",
  62   "NoEscape",
  63   "ArgEscape",
  64   "GlobalEscape"
  65 };
  66 
  67 static const char *edge_type_suffix[] = {
  68  "?", // UnknownEdge
  69  "P", // PointsToEdge
  70  "D", // DeferredEdge
  71  "F"  // FieldEdge
  72 };
  73 
  74 void PointsToNode::dump(bool print_state) const {
  75   NodeType nt = node_type();
  76   tty->print("%s ", node_type_names[(int) nt]);
  77   if (print_state) {
  78     EscapeState es = escape_state();
  79     tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
  80   }
  81   tty->print("[[");
  82   for (uint i = 0; i < edge_count(); i++) {
  83     tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
  84   }
  85   tty->print("]]  ");
  86   if (_node == NULL)
  87     tty->print_cr("<null>");
  88   else
  89     _node->dump();
  90 }
  91 #endif
  92 
  93 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  94   _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
  95   _processed(C->comp_arena()),
  96   pt_ptset(C->comp_arena()),
  97   pt_visited(C->comp_arena()),
  98   pt_worklist(C->comp_arena(), 4, 0, 0),
  99   _collecting(true),
 100   _progress(false),
 101   _compile(C),
 102   _igvn(igvn),
 103   _node_map(C->comp_arena()) {
 104 
 105   _phantom_object = C->top()->_idx,
 106   add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
 107 
 108   // Add ConP(#NULL) and ConN(#NULL) nodes.
 109   Node* oop_null = igvn->zerocon(T_OBJECT);
 110   _oop_null = oop_null->_idx;
 111   assert(_oop_null < nodes_size(), "should be created already");
 112   add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
 113 
 114   if (UseCompressedOops) {
 115     Node* noop_null = igvn->zerocon(T_NARROWOOP);
 116     _noop_null = noop_null->_idx;
 117     assert(_noop_null < nodes_size(), "should be created already");
 118     add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
 119   } else {
 120     _noop_null = _oop_null; // Should be initialized
 121   }
 122   _pcmp_neq = NULL; // Should be initialized
 123   _pcmp_eq  = NULL;
 124 }
 125 
 126 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
 127   PointsToNode *f = ptnode_adr(from_i);
 128   PointsToNode *t = ptnode_adr(to_i);
 129 
 130   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 131   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
 132   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
 133   if (to_i == _phantom_object) { // Quick test for most common object
 134     if (f->has_unknown_ptr()) {
 135       return;
 136     } else {
 137       f->set_has_unknown_ptr();
 138     }
 139   }
 140   add_edge(f, to_i, PointsToNode::PointsToEdge);
 141 }
 142 
 143 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
 144   PointsToNode *f = ptnode_adr(from_i);
 145   PointsToNode *t = ptnode_adr(to_i);
 146 
 147   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 148   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
 149   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
 150   // don't add a self-referential edge, this can occur during removal of
 151   // deferred edges
 152   if (from_i != to_i)
 153     add_edge(f, to_i, PointsToNode::DeferredEdge);
 154 }
 155 
 156 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
 157   const Type *adr_type = phase->type(adr);
 158   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
 159       adr->in(AddPNode::Address)->is_Proj() &&
 160       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
 161     // We are computing a raw address for a store captured by an Initialize
 162     // compute an appropriate address type. AddP cases #3 and #5 (see below).
 163     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 164     assert(offs != Type::OffsetBot ||
 165            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
 166            "offset must be a constant or it is initialization of array");
 167     return offs;
 168   }
 169   const TypePtr *t_ptr = adr_type->isa_ptr();
 170   assert(t_ptr != NULL, "must be a pointer type");
 171   return t_ptr->offset();
 172 }
 173 
 174 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
 175   // Don't add fields to NULL pointer.
 176   if (is_null_ptr(from_i))

 177     return;
 178   PointsToNode *f = ptnode_adr(from_i);
 179   PointsToNode *t = ptnode_adr(to_i);
 180 
 181   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
 182   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
 183   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
 184   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
 185   t->set_offset(offset);
 186 
 187   add_edge(f, to_i, PointsToNode::FieldEdge);
 188 }
 189 
 190 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
 191   // Don't change non-escaping state of NULL pointer.
 192   if (is_null_ptr(ni))




 193     return;
 194   PointsToNode *npt = ptnode_adr(ni);
 195   PointsToNode::EscapeState old_es = npt->escape_state();
 196   if (es > old_es)
 197     npt->set_escape_state(es);





 198 }
 199 
 200 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
 201                                PointsToNode::EscapeState es, bool done) {
 202   PointsToNode* ptadr = ptnode_adr(n->_idx);
 203   ptadr->_node = n;
 204   ptadr->set_node_type(nt);
 205 
 206   // inline set_escape_state(idx, es);
 207   PointsToNode::EscapeState old_es = ptadr->escape_state();
 208   if (es > old_es)
 209     ptadr->set_escape_state(es);
 210 
 211   if (done)
 212     _processed.set(n->_idx);





























 213 }
 214 
 215 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
 216   uint idx = n->_idx;
 217   PointsToNode::EscapeState es;








 218 
 219   // If we are still collecting or there were no non-escaping allocations
 220   // we don't know the answer yet
 221   if (_collecting)
 222     return PointsToNode::UnknownEscape;




 223 
 224   // if the node was created after the escape computation, return
 225   // UnknownEscape
 226   if (idx >= nodes_size())
 227     return PointsToNode::UnknownEscape;
 228 
 229   es = ptnode_adr(idx)->escape_state();







 230 
 231   // if we have already computed a value, return it
 232   if (es != PointsToNode::UnknownEscape &&
 233       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
 234     return es;
 235 
 236   // PointsTo() calls n->uncast() which can return a new ideal node.
 237   if (n->uncast()->_idx >= nodes_size())
 238     return PointsToNode::UnknownEscape;





 239 
 240   PointsToNode::EscapeState orig_es = es;

 241 
 242   // compute max escape state of anything this node could point to
 243   for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
 244     uint pt = i.elem;
 245     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
 246     if (pes > es)
 247       es = pes;









 248   }
 249   if (orig_es != es) {
 250     // cache the computed escape state
 251     assert(es > orig_es, "should have computed an escape state");
 252     set_escape_state(idx, es);
 253   } // orig_es could be PointsToNode::UnknownEscape
 254   return es;





 255 }
 256 
 257 VectorSet* ConnectionGraph::PointsTo(Node * n) {
 258   pt_ptset.Reset();
 259   pt_visited.Reset();
 260   pt_worklist.clear();

 261 
 262 #ifdef ASSERT
 263   Node *orig_n = n;
 264 #endif



 265 
 266   n = n->uncast();
 267   PointsToNode* npt = ptnode_adr(n->_idx);
 268 
 269   // If we have a JavaObject, return just that object
 270   if (npt->node_type() == PointsToNode::JavaObject) {
 271     pt_ptset.set(n->_idx);
 272     return &pt_ptset;







 273   }
 274 #ifdef ASSERT
 275   if (npt->_node == NULL) {
 276     if (orig_n != n)
 277       orig_n->dump();
 278     n->dump();
 279     assert(npt->_node != NULL, "unregistered node");
 280   }
 281 #endif
 282   pt_worklist.push(n->_idx);
 283   while(pt_worklist.length() > 0) {
 284     int ni = pt_worklist.pop();
 285     if (pt_visited.test_set(ni))
 286       continue;
 287 
 288     PointsToNode* pn = ptnode_adr(ni);
 289     // ensure that all inputs of a Phi have been processed
 290     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
 291 
 292     int edges_processed = 0;
 293     uint e_cnt = pn->edge_count();
 294     for (uint e = 0; e < e_cnt; e++) {
 295       uint etgt = pn->edge_target(e);
 296       PointsToNode::EdgeType et = pn->edge_type(e);
 297       if (et == PointsToNode::PointsToEdge) {
 298         pt_ptset.set(etgt);
 299         edges_processed++;
 300       } else if (et == PointsToNode::DeferredEdge) {
 301         pt_worklist.push(etgt);
 302         edges_processed++;


 303       } else {
 304         assert(false,"neither PointsToEdge or DeferredEdge");













 305       }





 306     }
 307     if (edges_processed == 0) {
 308       // no deferred or pointsto edges found.  Assume the value was set
 309       // outside this method.  Add the phantom object to the pointsto set.
 310       pt_ptset.set(_phantom_object);
 311     }
 312   }
 313   return &pt_ptset;
 314 }
 315 
 316 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
 317   // This method is most expensive during ConnectionGraph construction.
 318   // Reuse vectorSet and an additional growable array for deferred edges.
 319   deferred_edges->clear();
 320   visited->Reset();
 321 
 322   visited->set(ni);
 323   PointsToNode *ptn = ptnode_adr(ni);
 324   assert(ptn->node_type() == PointsToNode::LocalVar ||
 325          ptn->node_type() == PointsToNode::Field, "sanity");
 326   assert(ptn->edge_count() != 0, "should have at least phantom_object");
 327 
 328   // Mark current edges as visited and move deferred edges to separate array.
 329   for (uint i = 0; i < ptn->edge_count(); ) {
 330     uint t = ptn->edge_target(i);
 331 #ifdef ASSERT
 332     assert(!visited->test_set(t), "expecting no duplications");
 333 #else
 334     visited->set(t);
 335 #endif
 336     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
 337       ptn->remove_edge(t, PointsToNode::DeferredEdge);
 338       deferred_edges->append(t);
 339     } else {
 340       i++;
 341     }












 342   }
 343   for (int next = 0; next < deferred_edges->length(); ++next) {
 344     uint t = deferred_edges->at(next);
 345     PointsToNode *ptt = ptnode_adr(t);
 346     uint e_cnt = ptt->edge_count();
 347     assert(e_cnt != 0, "should have at least phantom_object");
 348     for (uint e = 0; e < e_cnt; e++) {
 349       uint etgt = ptt->edge_target(e);
 350       if (visited->test_set(etgt))
 351         continue;
 352 
 353       PointsToNode::EdgeType et = ptt->edge_type(e);
 354       if (et == PointsToNode::PointsToEdge) {
 355         add_pointsto_edge(ni, etgt);
 356       } else if (et == PointsToNode::DeferredEdge) {
 357         deferred_edges->append(etgt);

 358       } else {
 359         assert(false,"invalid connection graph");
 360       }
 361     }










 362   }
 363   if (ptn->edge_count() == 0) {
 364     // No pointsto edges found after deferred edges are removed.
 365     // For example, in the next case where call is replaced
 366     // with uncommon trap and as result array's load references
 367     // itself through deferred edges:
 368     //
 369     // A a = b[i];
 370     // if (c!=null) a = c.foo();
 371     // b[i] = a;
 372     //
 373     // Assume the value was set outside this method and
 374     // add edge to phantom object.
 375     add_pointsto_edge(ni, _phantom_object);
 376   }


 377 }
 378 



 379 
 380 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
 381 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
 382 //  a pointsto edge is added if it is a JavaObject

 383 
 384 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
 385   // No fields for NULL pointer.
 386   if (is_null_ptr(adr_i)) {
 387     return;





 388   }
 389   PointsToNode* an = ptnode_adr(adr_i);
 390   PointsToNode* to = ptnode_adr(to_i);
 391   bool deferred = (to->node_type() == PointsToNode::LocalVar);
 392   bool escaped  = (to_i == _phantom_object) && (offs == Type::OffsetTop);
 393   if (escaped) {
 394     // Values in fields escaped during call.
 395     assert(an->escape_state() >= PointsToNode::ArgEscape, "sanity");
 396     offs = Type::OffsetBot;
 397   }
 398   for (uint fe = 0; fe < an->edge_count(); fe++) {
 399     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
 400     int fi = an->edge_target(fe);
 401     if (escaped) {
 402       set_escape_state(fi, PointsToNode::GlobalEscape);













 403     }
 404     PointsToNode* pf = ptnode_adr(fi);
 405     int po = pf->offset();
 406     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
 407       if (deferred)
 408         add_deferred_edge(fi, to_i);
 409       else
 410         add_pointsto_edge(fi, to_i);

















 411     }
 412   }

 413 }
 414 
 415 // Add a deferred  edge from node given by "from_i" to any field of adr_i
 416 // whose offset matches "offset".
 417 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
 418   // No fields for NULL pointer.
 419   if (is_null_ptr(adr_i)) {
 420     return;


 421   }
 422   if (adr_i == _phantom_object) {
 423     // Add only one edge for unknown object.
 424     add_pointsto_edge(from_i, _phantom_object);
 425     return;












 426   }
 427   PointsToNode* an = ptnode_adr(adr_i);
 428   bool is_alloc = an->_node->is_Allocate();
 429   for (uint fe = 0; fe < an->edge_count(); fe++) {
 430     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
 431     int fi = an->edge_target(fe);
 432     PointsToNode* pf = ptnode_adr(fi);
 433     int offset = pf->offset();
 434     if (!is_alloc) {
 435       // Assume the field was set outside this method if it is not Allocation
 436       add_pointsto_edge(fi, _phantom_object);
 437     }
 438     if (offset == offs || offset == Type::OffsetBot || offs == Type::OffsetBot) {
 439       add_deferred_edge(from_i, fi);
 440     }
 441   }
 442   // Some fields references (AddP) may still be missing
 443   // until Connection Graph construction is complete.
 444   // For example, loads from RAW pointers with offset 0
 445   // which don't have AddP.
 446   // A reference to phantom_object will be added if
 447   // a field reference is still missing after completing
 448   // Connection Graph (see remove_deferred()).
 449 }
 450 
 451 // Helper functions
 452 
 453 static Node* get_addp_base(Node *addp) {
 454   assert(addp->is_AddP(), "must be AddP");
 455   //
 456   // AddP cases for Base and Address inputs:
 457   // case #1. Direct object's field reference:
 458   //     Allocate
 459   //       |
 460   //     Proj #5 ( oop result )
 461   //       |
 462   //     CheckCastPP (cast to instance type)
 463   //      | |
 464   //     AddP  ( base == address )
 465   //
 466   // case #2. Indirect object's field reference:
 467   //      Phi
 468   //       |
 469   //     CastPP (cast to instance type)
 470   //      | |
 471   //     AddP  ( base == address )
 472   //
 473   // case #3. Raw object's field reference for Initialize node:


 496   //
 497   // case #6. Constant Pool, ThreadLocal, CastX2P or
 498   //          Raw object's field reference:
 499   //      {ConP, ThreadLocal, CastX2P, raw Load}
 500   //  top   |
 501   //     \  |
 502   //     AddP  ( base == top )
 503   //
 504   // case #7. Klass's field reference.
 505   //      LoadKlass
 506   //       | |
 507   //       AddP  ( base == address )
 508   //
 509   // case #8. narrow Klass's field reference.
 510   //      LoadNKlass
 511   //       |
 512   //      DecodeN
 513   //       | |
 514   //       AddP  ( base == address )
 515   //
 516   Node *base = addp->in(AddPNode::Base)->uncast();
 517   if (base->is_top()) { // The AddP case #3 and #6.
 518     base = addp->in(AddPNode::Address)->uncast();
 519     while (base->is_AddP()) {
 520       // Case #6 (unsafe access) may have several chained AddP nodes.
 521       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
 522       base = base->in(AddPNode::Address)->uncast();
 523     }
 524     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
 525            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
 526            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
 527            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");


 528   }
 529   return base;
 530 }
 531 
 532 static Node* find_second_addp(Node* addp, Node* n) {
 533   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
 534 
 535   Node* addp2 = addp->raw_out(0);
 536   if (addp->outcnt() == 1 && addp2->is_AddP() &&
 537       addp2->in(AddPNode::Base) == n &&
 538       addp2->in(AddPNode::Address) == addp) {
 539 
 540     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
 541     //
 542     // Find array's offset to push it on worklist first and
 543     // as result process an array's element offset first (pushed second)
 544     // to avoid CastPP for the array's offset.
 545     // Otherwise the inserted CastPP (LocalVar) will point to what
 546     // the AddP (Field) points to. Which would be wrong since
 547     // the algorithm expects the CastPP has the same point as
 548     // as AddP's base CheckCastPP (LocalVar).
 549     //
 550     //    ArrayAllocation
 551     //     |
 552     //    CheckCastPP


 603   //
 604   // Or the type 't' could be not related to 'base_t' at all.
 605   // It could happened when CHA type is different from MDO type on a dead path
 606   // (for example, from instanceof check) which is not collapsed during parsing.
 607   //
 608   // Do nothing for such AddP node and don't process its users since
 609   // this code branch will go away.
 610   //
 611   if (!t->is_known_instance() &&
 612       !base_t->klass()->is_subtype_of(t->klass())) {
 613      return false; // bail out
 614   }
 615 
 616   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
 617   // Do NOT remove the next line: ensure a new alias index is allocated
 618   // for the instance type. Note: C++ will not remove it since the call
 619   // has side effect.
 620   int alias_idx = _compile->get_alias_index(tinst);
 621   igvn->set_type(addp, tinst);
 622   // record the allocation in the node map
 623   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
 624   set_map(addp->_idx, get_map(base->_idx));
 625 
 626   // Set addp's Base and Address to 'base'.
 627   Node *abase = addp->in(AddPNode::Base);
 628   Node *adr   = addp->in(AddPNode::Address);
 629   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
 630       adr->in(0)->_idx == (uint)inst_id) {
 631     // Skip AddP cases #3 and #5.
 632   } else {
 633     assert(!abase->is_top(), "sanity"); // AddP case #3
 634     if (abase != base) {
 635       igvn->hash_delete(addp);
 636       addp->set_req(AddPNode::Base, base);
 637       if (abase == adr) {
 638         addp->set_req(AddPNode::Address, base);
 639       } else {
 640         // AddP case #4 (adr is array's element offset AddP node)
 641 #ifdef ASSERT
 642         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
 643         assert(adr->is_AddP() && atype != NULL &&
 644                atype->instance_id() == inst_id, "array's element offset should be processed first");


 682         return phi->as_Phi();
 683       }
 684     }
 685   }
 686   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
 687     if (C->do_escape_analysis() == true && !C->failing()) {
 688       // Retry compilation without escape analysis.
 689       // If this is the first failure, the sentinel string will "stick"
 690       // to the Compile object, and the C2Compiler will see it and retry.
 691       C->record_failure(C2Compiler::retry_no_escape_analysis());
 692     }
 693     return NULL;
 694   }
 695   orig_phi_worklist.append_if_missing(orig_phi);
 696   const TypePtr *atype = C->get_adr_type(alias_idx);
 697   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
 698   C->copy_node_notes_to(result, orig_phi);
 699   igvn->set_type(result, result->bottom_type());
 700   record_for_optimizer(result);
 701 
 702   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
 703   assert(pn == NULL || pn == orig_phi, "wrong node");
 704   set_map(orig_phi->_idx, result);
 705   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
 706 
 707   new_created = true;
 708   return result;
 709 }
 710 
 711 //
 712 // Return a new version of Memory Phi "orig_phi" with the inputs having the
 713 // specified alias index.
 714 //
 715 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
 716 
 717   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
 718   Compile *C = _compile;
 719   bool new_phi_created;
 720   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
 721   if (!new_phi_created) {
 722     return result;
 723   }
 724 
 725   GrowableArray<PhiNode *>  phi_list;


 762       Node* in = result->in(i);
 763       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
 764     }
 765     // we have finished processing a Phi, see if there are any more to do
 766     finished = (phi_list.length() == 0 );
 767     if (!finished) {
 768       phi = phi_list.pop();
 769       idx = cur_input.pop();
 770       PhiNode *prev_result = get_map_phi(phi->_idx);
 771       prev_result->set_req(idx++, result);
 772       result = prev_result;
 773     }
 774   }
 775   return result;
 776 }
 777 
 778 
 779 //
 780 // The next methods are derived from methods in MemNode.
 781 //
 782 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
 783   Node *mem = mmem;
 784   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
 785   // means an array I have not precisely typed yet.  Do not do any
 786   // alias stuff with it any time soon.
 787   if( toop->base() != Type::AnyPtr &&
 788       !(toop->klass() != NULL &&
 789         toop->klass()->is_java_lang_Object() &&
 790         toop->offset() == Type::OffsetBot) ) {
 791     mem = mmem->memory_at(alias_idx);
 792     // Update input if it is progress over what we have now
 793   }
 794   return mem;
 795 }
 796 
 797 //
 798 // Move memory users to their memory slices.
 799 //
 800 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
 801   Compile* C = _compile;
 802 
 803   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
 804   assert(tp != NULL, "ptr type");
 805   int alias_idx = C->get_alias_index(tp);
 806   int general_idx = C->get_general_index(alias_idx);
 807 
 808   // Move users first
 809   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 810     Node* use = n->fast_out(i);


1060 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
1061 //
1062 //    40  StoreP  25  7   20   ... alias_index=4
1063 //    50  StoreP  35  7   30   ... alias_index=6
1064 //    60  StoreP  45  40  20   ... alias_index=4
1065 //    70  LoadP    _  50  30   ... alias_index=6
1066 //    80  Phi     75  40  60   Memory alias_index=4
1067 //   120  Phi     75  50  50   Memory alias_index=6
1068 //    90  LoadP    _ 120  30   ... alias_index=6
1069 //   100  LoadP    _  80  20   ... alias_index=4
1070 //
1071 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
1072   GrowableArray<Node *>  memnode_worklist;
1073   GrowableArray<PhiNode *>  orig_phis;
1074 
1075   PhaseIterGVN  *igvn = _igvn;
1076   uint new_index_start = (uint) _compile->num_alias_types();
1077   Arena* arena = Thread::current()->resource_area();
1078   VectorSet visited(arena);
1079 

1080 


1081   //  Phase 1:  Process possible allocations from alloc_worklist.
1082   //  Create instance types for the CheckCastPP for allocations where possible.
1083   //
1084   // (Note: don't forget to change the order of the second AddP node on
1085   //  the alloc_worklist if the order of the worklist processing is changed,
1086   //  see the comment in find_second_addp().)
1087   //
1088   while (alloc_worklist.length() != 0) {
1089     Node *n = alloc_worklist.pop();
1090     uint ni = n->_idx;
1091     const TypeOopPtr* tinst = NULL;
1092     if (n->is_Call()) {
1093       CallNode *alloc = n->as_Call();
1094       // copy escape information to call node
1095       PointsToNode* ptn = ptnode_adr(alloc->_idx);
1096       PointsToNode::EscapeState es = escape_state(alloc);
1097       // We have an allocation or call which returns a Java object,
1098       // see if it is unescaped.
1099       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
1100         continue;
1101 
1102       // Find CheckCastPP for the allocate or for the return value of a call
1103       n = alloc->result_cast();
1104       if (n == NULL) {            // No uses except Initialize node
1105         if (alloc->is_Allocate()) {
1106           // Set the scalar_replaceable flag for allocation
1107           // so it could be eliminated if it has no uses.
1108           alloc->as_Allocate()->_is_scalar_replaceable = true;
1109         }
1110         continue;
1111       }
1112       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1113         assert(!alloc->is_Allocate(), "allocation should have unique type");
1114         continue;
1115       }
1116 


1128           Node *use = n->fast_out(i);
1129           if (use->is_CheckCastPP()) {
1130             cast2 = use;
1131             break;
1132           }
1133         }
1134         if (cast2 != NULL) {
1135           n = cast2;
1136         } else {
1137           // Non-scalar replaceable if the allocation type is unknown statically
1138           // (reflection allocation), the object can't be restored during
1139           // deoptimization without precise type.
1140           continue;
1141         }
1142       }
1143       if (alloc->is_Allocate()) {
1144         // Set the scalar_replaceable flag for allocation
1145         // so it could be eliminated.
1146         alloc->as_Allocate()->_is_scalar_replaceable = true;
1147       }
1148       set_escape_state(n->_idx, es); // CheckCastPP escape state
1149       // in order for an object to be scalar-replaceable, it must be:
1150       //   - a direct allocation (not a call returning an object)
1151       //   - non-escaping
1152       //   - eligible to be a unique type
1153       //   - not determined to be ineligible by escape analysis
1154       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
1155              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
1156       set_map(alloc->_idx, n);
1157       set_map(n->_idx, alloc);
1158       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1159       if (t == NULL)
1160         continue;  // not a TypeOopPtr
1161       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1162       igvn->hash_delete(n);
1163       igvn->set_type(n,  tinst);
1164       n->raise_bottom_type(tinst);
1165       igvn->hash_insert(n);
1166       record_for_optimizer(n);
1167       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
1168 
1169         // First, put on the worklist all Field edges from Connection Graph
1170         // which is more accurate then putting immediate users from Ideal Graph.
1171         for (uint e = 0; e < ptn->edge_count(); e++) {
1172           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
1173           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),

1174                  "only AddP nodes are Field edges in CG");
1175           if (use->outcnt() > 0) { // Don't process dead nodes
1176             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1177             if (addp2 != NULL) {
1178               assert(alloc->is_AllocateArray(),"array allocation was expected");
1179               alloc_worklist.append_if_missing(addp2);
1180             }
1181             alloc_worklist.append_if_missing(use);
1182           }
1183         }
1184 
1185         // An allocation may have an Initialize which has raw stores. Scan
1186         // the users of the raw allocation result and push AddP users
1187         // on alloc_worklist.
1188         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1189         assert (raw_result != NULL, "must have an allocation result");
1190         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1191           Node *use = raw_result->fast_out(i);
1192           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1193             Node* addp2 = find_second_addp(use, raw_result);
1194             if (addp2 != NULL) {
1195               assert(alloc->is_AllocateArray(),"array allocation was expected");
1196               alloc_worklist.append_if_missing(addp2);
1197             }
1198             alloc_worklist.append_if_missing(use);
1199           } else if (use->is_MemBar()) {
1200             memnode_worklist.append_if_missing(use);
1201           }
1202         }
1203       }
1204     } else if (n->is_AddP()) {
1205       VectorSet* ptset = PointsTo(get_addp_base(n));
1206       assert(ptset->Size() == 1, "AddP address is unique");
1207       uint elem = ptset->getelem(); // Allocation node's index
1208       if (elem == _phantom_object) {
1209         assert(false, "escaped allocation");
1210         continue; // Assume the value was set outside this method.



1211       }
1212       Node *base = get_map(elem);  // CheckCastPP node
1213       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
1214       tinst = igvn->type(base)->isa_oopptr();
1215     } else if (n->is_Phi() ||
1216                n->is_CheckCastPP() ||
1217                n->is_EncodeP() ||
1218                n->is_DecodeN() ||
1219                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1220       if (visited.test_set(n->_idx)) {
1221         assert(n->is_Phi(), "loops only through Phi's");
1222         continue;  // already processed
1223       }
1224       VectorSet* ptset = PointsTo(n);
1225       if (ptset->Size() == 1) {
1226         uint elem = ptset->getelem(); // Allocation node's index
1227         if (elem == _phantom_object) {
1228           assert(false, "escaped allocation");
1229           continue; // Assume the value was set outside this method.
1230         }
1231         Node *val = get_map(elem);   // CheckCastPP node


1232         TypeNode *tn = n->as_Type();
1233         tinst = igvn->type(val)->isa_oopptr();
1234         assert(tinst != NULL && tinst->is_known_instance() &&
1235                (uint)tinst->instance_id() == elem , "instance type expected.");
1236 
1237         const Type *tn_type = igvn->type(tn);
1238         const TypeOopPtr *tn_t;
1239         if (tn_type->isa_narrowoop()) {
1240           tn_t = tn_type->make_ptr()->isa_oopptr();
1241         } else {
1242           tn_t = tn_type->isa_oopptr();
1243         }
1244 
1245         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1246           if (tn_type->isa_narrowoop()) {
1247             tn_type = tinst->make_narrowoop();
1248           } else {
1249             tn_type = tinst;
1250           }
1251           igvn->hash_delete(tn);
1252           igvn->set_type(tn, tn_type);
1253           tn->set_type(tn_type);
1254           igvn->hash_insert(tn);
1255           record_for_optimizer(n);


1298           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1299         }
1300       } else {
1301         uint op = use->Opcode();
1302         if (!(op == Op_CmpP || op == Op_Conv2B ||
1303               op == Op_CastP2X || op == Op_StoreCM ||
1304               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1305               op == Op_StrEquals || op == Op_StrIndexOf)) {
1306           n->dump();
1307           use->dump();
1308           assert(false, "EA: missing allocation reference path");
1309         }
1310 #endif
1311       }
1312     }
1313 
1314   }
1315   // New alias types were created in split_AddP().
1316   uint new_index_end = (uint) _compile->num_alias_types();
1317 


1318   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
1319   //            compute new values for Memory inputs  (the Memory inputs are not
1320   //            actually updated until phase 4.)
1321   if (memnode_worklist.length() == 0)
1322     return;  // nothing to do
1323 
1324   while (memnode_worklist.length() != 0) {
1325     Node *n = memnode_worklist.pop();
1326     if (visited.test_set(n->_idx))
1327       continue;
1328     if (n->is_Phi() || n->is_ClearArray()) {
1329       // we don't need to do anything, but the users must be pushed
1330     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1331       // we don't need to do anything, but the users must be pushed
1332       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1333       if (n == NULL)
1334         continue;
1335     } else {
1336       assert(n->is_Mem(), "memory node required.");
1337       Node *addr = n->in(MemNode::Address);
1338       const Type *addr_t = igvn->type(addr);
1339       if (addr_t == Type::TOP)
1340         continue;
1341       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1342       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1343       assert ((uint)alias_idx < new_index_end, "wrong alias index");
1344       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1345       if (_compile->failing()) {
1346         return;
1347       }
1348       if (mem != n->in(MemNode::Memory)) {
1349         // We delay the memory edge update since we need old one in
1350         // MergeMem code below when instances memory slices are separated.
1351         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
1352         assert(pn == NULL || pn == n, "wrong node");
1353         set_map(n->_idx, mem);
1354         ptnode_adr(n->_idx)->_node = n;
1355       }
1356       if (n->is_Load()) {
1357         continue;  // don't push users
1358       } else if (n->is_LoadStore()) {
1359         // get the memory projection
1360         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1361           Node *use = n->fast_out(i);
1362           if (use->Opcode() == Op_SCMemProj) {
1363             n = use;
1364             break;
1365           }
1366         }
1367         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1368       }
1369     }
1370     // push user on appropriate worklist
1371     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1372       Node *use = n->fast_out(i);
1373       if (use->is_Phi() || use->is_ClearArray()) {
1374         memnode_worklist.append_if_missing(use);


1486       if (_compile->failing()) {
1487         return;
1488       }
1489       if (mem != new_mem) {
1490         phi->set_req(i, new_mem);
1491       }
1492     }
1493     igvn->hash_insert(phi);
1494     record_for_optimizer(phi);
1495   }
1496 
1497   // Update the memory inputs of MemNodes with the value we computed
1498   // in Phase 2 and move stores memory users to corresponding memory slices.
1499 
1500   // Disable memory split verification code until the fix for 6984348.
1501   // Currently it produces false negative results since it does not cover all cases.
1502 #if 0 // ifdef ASSERT
1503   visited.Reset();
1504   Node_Stack old_mems(arena, _compile->unique() >> 2);
1505 #endif
1506   for (uint i = 0; i < nodes_size(); i++) {
1507     Node *nmem = get_map(i);
1508     if (nmem != NULL) {
1509       Node *n = ptnode_adr(i)->_node;
1510       assert(n != NULL, "sanity");
1511       if (n->is_Mem()) {
1512 #if 0 // ifdef ASSERT
1513         Node* old_mem = n->in(MemNode::Memory);
1514         if (!visited.test_set(old_mem->_idx)) {
1515           old_mems.push(old_mem, old_mem->outcnt());
1516         }
1517 #endif
1518         assert(n->in(MemNode::Memory) != nmem, "sanity");
1519         if (!n->is_Load()) {
1520           // Move memory users of a store first.
1521           move_inst_mem(n, orig_phis, igvn);
1522         }
1523         // Now update memory input
1524         igvn->hash_delete(n);
1525         n->set_req(MemNode::Memory, nmem);
1526         igvn->hash_insert(n);
1527         record_for_optimizer(n);
1528       } else {
1529         assert(n->is_Allocate() || n->is_CheckCastPP() ||
1530                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1531       }
1532     }
1533   }
1534 #if 0 // ifdef ASSERT
1535   // Verify that memory was split correctly
1536   while (old_mems.is_nonempty()) {
1537     Node* old_mem = old_mems.node();
1538     uint  old_cnt = old_mems.index();
1539     old_mems.pop();
1540     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
1541   }
1542 #endif
1543 }
1544 
1545 bool ConnectionGraph::has_candidates(Compile *C) {
1546   // EA brings benefits only when the code has allocations and/or locks which
1547   // are represented by ideal Macro nodes.
1548   int cnt = C->macro_count();
1549   for( int i=0; i < cnt; i++ ) {
1550     Node *n = C->macro_node(i);
1551     if ( n->is_Allocate() )
1552       return true;
1553     if( n->is_Lock() ) {
1554       Node* obj = n->as_Lock()->obj_node()->uncast();
1555       if( !(obj->is_Parm() || obj->is_Con()) )
1556         return true;
1557     }
1558   }
1559   return false;
1560 }
1561 
1562 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {


1563   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1564   // to create space for them in ConnectionGraph::_nodes[].
1565   Node* oop_null = igvn->zerocon(T_OBJECT);
1566   Node* noop_null = igvn->zerocon(T_NARROWOOP);
1567 
1568   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1569   // Perform escape analysis
1570   if (congraph->compute_escape()) {
1571     // There are non escaping objects.
1572     C->set_congraph(congraph);
1573   }
1574 
1575   // Cleanup.
1576   if (oop_null->outcnt() == 0)
1577     igvn->hash_delete(oop_null);
1578   if (noop_null->outcnt() == 0)
1579     igvn->hash_delete(noop_null);
1580 }
1581 
1582 bool ConnectionGraph::compute_escape() {
1583   Compile* C = _compile;

1584 
1585   // 1. Populate Connection Graph (CG) with Ideal nodes.
1586 
1587   Unique_Node_List worklist_init;
1588   worklist_init.map(C->unique(), NULL);  // preallocate space
1589 
1590   // Initialize worklist
1591   if (C->root() != NULL) {
1592     worklist_init.push(C->root());
1593   }
1594 



1595   GrowableArray<Node*> alloc_worklist;
1596   GrowableArray<Node*> addp_worklist;
1597   GrowableArray<Node*> ptr_cmp_worklist;
1598   GrowableArray<Node*> storestore_worklist;
1599   PhaseGVN* igvn = _igvn;
1600 







1601   // Push all useful nodes onto CG list and set their type.
1602   for( uint next = 0; next < worklist_init.size(); ++next ) {
1603     Node* n = worklist_init.at(next);
1604     record_for_escape_analysis(n, igvn);
1605     // Only allocations and java static calls results are checked
1606     // for an escape status. See process_call_result() below.
1607     if (n->is_Allocate() || n->is_CallStaticJava() &&
1608         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
1609       alloc_worklist.append(n);
1610     } else if(n->is_AddP()) {
1611       // Collect address nodes. Use them during stage 3 below
1612       // to build initial connection graph field edges.
1613       addp_worklist.append(n);
1614     } else if (n->is_MergeMem()) {








1615       // Collect all MergeMem nodes to add memory slices for
1616       // scalar replaceable objects in split_unique_types().
1617       _mergemem_worklist.append(n->as_MergeMem());
1618     } else if (OptimizePtrCompare && n->is_Cmp() &&
1619                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
1620       // Compare pointers nodes
1621       ptr_cmp_worklist.append(n);
1622     } else if (n->is_MemBarStoreStore()) {
1623       // Collect all MemBarStoreStore nodes so that depending on the
1624       // escape status of the associated Allocate node some of them
1625       // may be eliminated.
1626       storestore_worklist.append(n);






1627     }
1628     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1629       Node* m = n->fast_out(i);   // Get user
1630       worklist_init.push(m);
1631     }
1632   }
1633 
1634   if (alloc_worklist.length() == 0) {
1635     _collecting = false;
1636     return false; // Nothing to do.
1637   }
1638 
1639   // 2. First pass to create simple CG edges (doesn't require to walk CG).
1640   uint delayed_size = _delayed_worklist.size();
1641   for( uint next = 0; next < delayed_size; ++next ) {
1642     Node* n = _delayed_worklist.at(next);
1643     build_connection_graph(n, igvn);
1644   }
1645 
1646   // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
1647   //    to reduce number of iterations during stage 4 below.
1648   uint addp_length = addp_worklist.length();
1649   for( uint next = 0; next < addp_length; ++next ) {
1650     Node* n = addp_worklist.at(next);
1651     Node* base = get_addp_base(n);
1652     if (base->is_Proj() && base->in(0)->is_Call())
1653       base = base->in(0);
1654     PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
1655     if (nt == PointsToNode::JavaObject) {
1656       build_connection_graph(n, igvn);
1657     }
1658   }
1659 
1660   GrowableArray<int> cg_worklist;
1661   cg_worklist.append(_phantom_object);
1662   GrowableArray<uint>  worklist;
1663 
1664   // 4. Build Connection Graph which need
1665   //    to walk the connection graph.
1666   _progress = false;
1667   for (uint ni = 0; ni < nodes_size(); ni++) {
1668     PointsToNode* ptn = ptnode_adr(ni);
1669     Node *n = ptn->_node;
1670     if (n != NULL) { // Call, AddP, LoadP, StoreP
1671       build_connection_graph(n, igvn);
1672       if (ptn->node_type() != PointsToNode::UnknownType)
1673         cg_worklist.append(n->_idx); // Collect CG nodes
1674       if (!_processed.test(n->_idx))
1675         worklist.append(n->_idx); // Collect C/A/L/S nodes
1676     }
1677   }



1678 
1679   // After IGVN user nodes may have smaller _idx than
1680   // their inputs so they will be processed first in
1681   // previous loop. Because of that not all Graph
1682   // edges will be created. Walk over interesting
1683   // nodes again until no new edges are created.
1684   //
1685   // Normally only 1-3 passes needed to build
1686   // Connection Graph depending on graph complexity.
1687   // Observed 8 passes in jvm2008 compiler.compiler.
1688   // Set limit to 20 to catch situation when something
1689   // did go wrong and recompile the method without EA.
1690   // Also limit build time to 30 sec (60 in debug VM).
1691 
1692 #define CG_BUILD_ITER_LIMIT 20
1693 
1694 #ifdef ASSERT
1695 #define CG_BUILD_TIME_LIMIT 60.0
1696 #else
1697 #define CG_BUILD_TIME_LIMIT 30.0
1698 #endif
1699 
1700   uint length = worklist.length();
1701   int iterations = 0;












1702   elapsedTimer time;
1703   while(_progress &&


1704         (iterations++   < CG_BUILD_ITER_LIMIT) &&
1705         (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1706     time.start();
1707     _progress = false;
1708     for( uint next = 0; next < length; ++next ) {
1709       int ni = worklist.at(next);
1710       PointsToNode* ptn = ptnode_adr(ni);
1711       Node* n = ptn->_node;
1712       assert(n != NULL, "should be known node");
1713       build_connection_graph(n, igvn);
1714     }







1715     time.stop();
1716   }


















1717   if ((iterations     >= CG_BUILD_ITER_LIMIT) ||
1718       (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1719     assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1720            time.seconds(), iterations, nodes_size(), length));
1721     // Possible infinite build_connection_graph loop,
1722     // bailout (no changes to ideal graph were made).
1723     _collecting = false;
1724     return false;
1725   }








1726 #undef CG_BUILD_ITER_LIMIT
1727 #undef CG_BUILD_TIME_LIMIT
1728 
1729   // 5. Propagate escaped states.
1730   worklist.clear();
1731 
1732   // mark all nodes reachable from GlobalEscape nodes
1733   (void)propagate_escape_state(&cg_worklist, &worklist, PointsToNode::GlobalEscape);
1734 
1735   // mark all nodes reachable from ArgEscape nodes
1736   bool has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ArgEscape);



1737 
1738   Arena* arena = Thread::current()->resource_area();
1739   VectorSet visited(arena);
1740 
1741   // 6. Find fields initializing values for not escaped allocations
1742   uint alloc_length = alloc_worklist.length();
1743   for (uint next = 0; next < alloc_length; ++next) {
1744     Node* n = alloc_worklist.at(next);
1745     PointsToNode::EscapeState es = ptnode_adr(n->_idx)->escape_state();
1746     if (es == PointsToNode::NoEscape) {
1747       has_non_escaping_obj = true;






1748       if (n->is_Allocate()) {
1749         find_init_values(n, &visited, igvn);
1750         // The object allocated by this Allocate node will never be
1751         // seen by an other thread. Mark it so that when it is
1752         // expanded no MemBarStoreStore is added.
1753         n->as_Allocate()->initialization()->set_does_not_escape();


1754       }
1755     } else if ((es == PointsToNode::ArgEscape) && n->is_Allocate()) {
1756       // Same as above. Mark this Allocate node so that when it is
1757       // expanded no MemBarStoreStore is added.
1758       n->as_Allocate()->initialization()->set_does_not_escape();
1759     }
1760   }
1761 
1762   uint cg_length = cg_worklist.length();
1763 
1764   // Skip the rest of code if all objects escaped.
1765   if (!has_non_escaping_obj) {
1766     cg_length = 0;
1767     addp_length = 0;













1768   }
1769 
1770   for (uint next = 0; next < cg_length; ++next) {
1771     int ni = cg_worklist.at(next);
1772     PointsToNode* ptn = ptnode_adr(ni);
1773     PointsToNode::NodeType nt = ptn->node_type();
1774     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1775       if (ptn->edge_count() == 0) {
1776         // No values were found. Assume the value was set
1777         // outside this method - add edge to phantom object.
1778         add_pointsto_edge(ni, _phantom_object);
1779       }
1780     }




1781   }
1782 
1783   // 7. Remove deferred edges from the graph.
1784   for (uint next = 0; next < cg_length; ++next) {
1785     int ni = cg_worklist.at(next);
1786     PointsToNode* ptn = ptnode_adr(ni);
1787     PointsToNode::NodeType nt = ptn->node_type();
1788     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
1789       remove_deferred(ni, &worklist, &visited);
1790     }
1791   }
1792 
1793   // 8. Adjust escape state of nonescaping objects.
1794   for (uint next = 0; next < addp_length; ++next) {
1795     Node* n = addp_worklist.at(next);
1796     adjust_escape_state(n);
1797   }

1798 
1799   // push all NoEscape nodes on the worklist
1800   worklist.clear();
1801   for( uint next = 0; next < cg_length; ++next ) {
1802     int nk = cg_worklist.at(next);
1803     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape &&
1804         !is_null_ptr(nk))
1805       worklist.push(nk);
1806   }
1807 
1808   alloc_worklist.clear();
1809   // Propagate scalar_replaceable value.
1810   while(worklist.length() > 0) {
1811     uint nk = worklist.pop();
1812     PointsToNode* ptn = ptnode_adr(nk);
1813     Node* n = ptn->_node;
1814     bool scalar_replaceable = ptn->scalar_replaceable();
1815     if (n->is_Allocate() && scalar_replaceable) {
1816       // Push scalar replaceable allocations on alloc_worklist
1817       // for processing in split_unique_types(). Note,
1818       // following code may change scalar_replaceable value.
1819       alloc_worklist.append(n);
1820     }
1821     uint e_cnt = ptn->edge_count();
1822     for (uint ei = 0; ei < e_cnt; ei++) {
1823       uint npi = ptn->edge_target(ei);
1824       if (is_null_ptr(npi))
1825         continue;
1826       PointsToNode *np = ptnode_adr(npi);
1827       if (np->escape_state() < PointsToNode::NoEscape) {
1828         set_escape_state(npi, PointsToNode::NoEscape);
1829         if (!scalar_replaceable) {
1830           np->set_scalar_replaceable(false);
1831         }
1832         worklist.push(npi);
1833       } else if (np->scalar_replaceable() && !scalar_replaceable) {
1834         np->set_scalar_replaceable(false);
1835         worklist.push(npi);
1836       }








1837     }








1838   }

1839 
1840   _collecting = false;
1841   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1842 
1843   assert(ptnode_adr(_oop_null)->escape_state() == PointsToNode::NoEscape &&
1844          ptnode_adr(_oop_null)->edge_count() == 0, "sanity");
1845   if (UseCompressedOops) {
1846     assert(ptnode_adr(_noop_null)->escape_state() == PointsToNode::NoEscape &&
1847            ptnode_adr(_noop_null)->edge_count() == 0, "sanity");
1848   }
1849 




1850   if (EliminateLocks && has_non_escaping_obj) {
1851     // Mark locks before changing ideal graph.
1852     int cnt = C->macro_count();
1853     for( int i=0; i < cnt; i++ ) {
1854       Node *n = C->macro_node(i);
1855       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1856         AbstractLockNode* alock = n->as_AbstractLock();
1857         if (!alock->is_non_esc_obj()) {
1858           PointsToNode::EscapeState es = escape_state(alock->obj_node());
1859           assert(es != PointsToNode::UnknownEscape, "should know");
1860           if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
1861             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1862             // The lock could be marked eliminated by lock coarsening
1863             // code during first IGVN before EA. Replace coarsened flag
1864             // to eliminate all associated locks/unlocks.
1865             alock->set_non_esc_obj();
1866           }
1867         }
1868       }
1869     }
1870   }
1871 
1872   if (OptimizePtrCompare && has_non_escaping_obj) {
1873     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1874     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1875     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1876     // Optimize objects compare.
1877     while (ptr_cmp_worklist.length() != 0) {
1878       Node *n = ptr_cmp_worklist.pop();
1879       Node *res = optimize_ptr_compare(n);
1880       if (res != NULL) {


1900   // escape status of associated AllocateNode and optimize out
1901   // MemBarStoreStore node if the allocated object never escapes.
1902   while (storestore_worklist.length() != 0) {
1903     Node *n = storestore_worklist.pop();
1904     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1905     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1906     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1907     PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
1908     if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
1909       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1910       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1911       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1912 
1913       _igvn->register_new_node_with_optimizer(mb);
1914       _igvn->replace_node(storestore, mb);
1915     }
1916   }
1917 
1918 #ifndef PRODUCT
1919   if (PrintEscapeAnalysis) {
1920     dump(); // Dump ConnectionGraph
1921   }
1922 #endif
1923 
1924   bool has_scalar_replaceable_candidates = false;
1925   alloc_length = alloc_worklist.length();


1926   for (uint next = 0; next < alloc_length; ++next) {
1927     Node* n = alloc_worklist.at(next);
1928     PointsToNode* ptn = ptnode_adr(n->_idx);
1929     assert(ptn->escape_state() == PointsToNode::NoEscape, "sanity");
1930     if (ptn->scalar_replaceable()) {
1931       has_scalar_replaceable_candidates = true;
1932       break;
1933     }
1934   }

1935 
1936   if ( has_scalar_replaceable_candidates &&
1937        C->AliasLevel() >= 3 && EliminateAllocations ) {
1938 
1939     // Now use the escape information to create unique types for
1940     // scalar replaceable objects.
1941     split_unique_types(alloc_worklist);
1942 
1943     if (C->failing())  return false;
1944 
1945     C->print_method("After Escape Analysis", 2);
1946 
1947 #ifdef ASSERT
1948   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
1949     tty->print("=== No allocations eliminated for ");
1950     C->method()->print_short_name();
1951     if(!EliminateAllocations) {
1952       tty->print(" since EliminateAllocations is off ===");
1953     } else if(!has_scalar_replaceable_candidates) {
1954       tty->print(" since there are no scalar replaceable candidates ===");
1955     } else if(C->AliasLevel() < 3) {
1956       tty->print(" since AliasLevel < 3 ===");
1957     }
1958     tty->cr();
1959 #endif
1960   }
1961   return has_non_escaping_obj;
1962 }
1963 

























1964 // Find fields initializing values for allocations.
1965 void ConnectionGraph::find_init_values(Node* alloc, VectorSet* visited, PhaseTransform* phase) {
1966   assert(alloc->is_Allocate(), "Should be called for Allocate nodes only");
1967   PointsToNode* pta = ptnode_adr(alloc->_idx);
1968   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");







































1969   InitializeNode* ini = alloc->as_Allocate()->initialization();
1970 
1971   Compile* C = _compile;
1972   visited->Reset();


1973   // Check if a oop field's initializing value is recorded and add
1974   // a corresponding NULL field's value if it is not recorded.
1975   // Connection Graph does not record a default initialization by NULL
1976   // captured by Initialize node.
1977   //
1978   uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
1979   uint ae_cnt = pta->edge_count();
1980   bool visited_bottom_offset = false;
1981   for (uint ei = 0; ei < ae_cnt; ei++) {
1982     uint nidx = pta->edge_target(ei); // Field (AddP)
1983     PointsToNode* ptn = ptnode_adr(nidx);
1984     assert(ptn->_node->is_AddP(), "Should be AddP nodes only");
1985     int offset = ptn->offset();


1986     if (offset == Type::OffsetBot) {
1987       if (!visited_bottom_offset) {
1988         visited_bottom_offset = true;
1989         // Check only oop fields.
1990         const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
1991         if (!adr_type->isa_aryptr() ||
1992             (adr_type->isa_aryptr()->klass() == NULL) ||
1993              adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
1994           // OffsetBot is used to reference array's element,
1995           // always add reference to NULL since we don't
1996           // known which element is referenced.
1997           add_edge_from_fields(alloc->_idx, null_idx, offset);




1998         }
1999       }
2000     } else if (offset != oopDesc::klass_offset_in_bytes() &&
2001                !visited->test_set(offset)) {
2002 
2003       // Check only oop fields.
2004       const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
2005       BasicType basic_field_type = T_INT;
2006       if (adr_type->isa_instptr()) {
2007         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
2008         if (field != NULL) {
2009           basic_field_type = field->layout_type();
2010         } else {
2011           // Ignore non field load (for example, klass load)
2012         }
2013       } else if (adr_type->isa_aryptr()) {
2014         if (offset != arrayOopDesc::length_offset_in_bytes()) {
2015           const Type* elemtype = adr_type->isa_aryptr()->elem();
2016           basic_field_type = elemtype->array_element_basic_type();
2017         } else {
2018           // Ignore array length load
2019         }
2020 #ifdef ASSERT
2021       } else {
2022         // Raw pointers are used for initializing stores so skip it
2023         // since it should be recorded already
2024         Node* base = get_addp_base(ptn->_node);
2025         assert(adr_type->isa_rawptr() && base->is_Proj() &&
2026                (base->in(0) == alloc),"unexpected pointer type");
2027 #endif

2028       }
2029       if (basic_field_type == T_OBJECT ||
2030           basic_field_type == T_NARROWOOP ||
2031           basic_field_type == T_ARRAY) {
2032         Node* value = NULL;
2033         if (ini != NULL) {
2034           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
2035           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
2036           if (store != NULL && store->is_Store()) {
2037             value = store->in(MemNode::ValueIn);
2038           } else {
2039             // There could be initializing stores which follow allocation.
2040             // For example, a volatile field store is not collected
2041             // by Initialize node.
2042             //
2043             // Need to check for dependent loads to separate such stores from
2044             // stores which follow loads. For now, add initial value NULL so
2045             // that compare pointers optimization works correctly.
2046           }
2047         }
2048         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
2049           // A field's initializing value was not recorded. Add NULL.
2050           add_edge_from_fields(alloc->_idx, null_idx, offset);



2051         }
2052       }
2053     }
2054   }


2055 }
2056 
2057 // Adjust escape state after Connection Graph is built.
2058 void ConnectionGraph::adjust_escape_state(Node* n) {
2059   PointsToNode* ptn = ptnode_adr(n->_idx);
2060   assert(n->is_AddP(), "Should be called for AddP nodes only");
2061   // Search for objects which are not scalar replaceable
2062   // and mark them to propagate the state to referenced objects.



2063   //














2064 
2065   int offset = ptn->offset();
2066   Node* base = get_addp_base(n);
2067   VectorSet* ptset = PointsTo(base);
2068   int ptset_size = ptset->Size();










2069 
2070   // An object is not scalar replaceable if the field which may point
2071   // to it has unknown offset (unknown element of an array of objects).
2072   //


2073 


2074   if (offset == Type::OffsetBot) {
2075     uint e_cnt = ptn->edge_count();
2076     for (uint ei = 0; ei < e_cnt; ei++) {
2077       uint npi = ptn->edge_target(ei);
2078       ptnode_adr(npi)->set_scalar_replaceable(false);
2079     }
2080   }
2081 
2082   // Currently an object is not scalar replaceable if a LoadStore node
2083   // access its field since the field value is unknown after it.
2084   //
2085   bool has_LoadStore = false;
2086   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2087     Node *use = n->fast_out(i);
2088     if (use->is_LoadStore()) {
2089       has_LoadStore = true;
2090       break;
2091     }
2092   }
2093   // An object is not scalar replaceable if the address points
2094   // to unknown field (unknown element for arrays, offset is OffsetBot).
2095   //
2096   // Or the address may point to more then one object. This may produce
2097   // the false positive result (set not scalar replaceable)
2098   // since the flow-insensitive escape analysis can't separate
2099   // the case when stores overwrite the field's value from the case
2100   // when stores happened on different control branches.
2101   //
2102   // Note: it will disable scalar replacement in some cases:
2103   //
2104   //    Point p[] = new Point[1];
2105   //    p[0] = new Point(); // Will be not scalar replaced
2106   //
2107   // but it will save us from incorrect optimizations in next cases:
2108   //
2109   //    Point p[] = new Point[1];
2110   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
2111   //
2112   if (ptset_size > 1 || ptset_size != 0 &&
2113       (has_LoadStore || offset == Type::OffsetBot)) {
2114     for( VectorSetI j(ptset); j.test(); ++j ) {
2115       ptnode_adr(j.elem)->set_scalar_replaceable(false);







2116     }
2117   }


2118 }
2119 
2120 // Propagate escape states to referenced nodes.
2121 bool ConnectionGraph::propagate_escape_state(GrowableArray<int>* cg_worklist,
2122                                              GrowableArray<uint>* worklist,
2123                                              PointsToNode::EscapeState esc_state) {
2124   bool has_java_obj = false;
2125 
2126   // push all nodes with the same escape state on the worklist
2127   uint cg_length = cg_worklist->length();
2128   for (uint next = 0; next < cg_length; ++next) {
2129     int nk = cg_worklist->at(next);
2130     if (ptnode_adr(nk)->escape_state() == esc_state)
2131       worklist->push(nk);







2132   }
2133   // mark all reachable nodes
2134   while (worklist->length() > 0) {
2135     int pt = worklist->pop();
2136     PointsToNode* ptn = ptnode_adr(pt);
2137     if (ptn->node_type() == PointsToNode::JavaObject &&
2138         !is_null_ptr(pt)) {
2139       has_java_obj = true;
2140       if (esc_state > PointsToNode::NoEscape) {
2141         // fields values are unknown if object escapes
2142         add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2143       }











2144     }
2145     uint e_cnt = ptn->edge_count();
2146     for (uint ei = 0; ei < e_cnt; ei++) {
2147       uint npi = ptn->edge_target(ei);
2148       if (is_null_ptr(npi))
2149         continue;
2150       PointsToNode *np = ptnode_adr(npi);
2151       if (np->escape_state() < esc_state) {
2152         set_escape_state(npi, esc_state);
2153         worklist->push(npi);
2154       }









2155     }





2156   }
2157   // Has not escaping java objects
2158   return has_java_obj && (esc_state < PointsToNode::GlobalEscape);



































2159 }
2160 
2161 // Optimize objects compare.
2162 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
2163   assert(OptimizePtrCompare, "sanity");
2164   // Clone returned Set since PointsTo() returns pointer
2165   // to the same structure ConnectionGraph.pt_ptset.
2166   VectorSet ptset1 = *PointsTo(n->in(1));
2167   VectorSet ptset2 = *PointsTo(n->in(2));
2168 








2169   // Check simple cases first.
2170   if (ptset1.Size() == 1) {
2171     uint pt1 = ptset1.getelem();
2172     PointsToNode* ptn1 = ptnode_adr(pt1);
2173     if (ptn1->escape_state() == PointsToNode::NoEscape) {
2174       if (ptset2.Size() == 1 && ptset2.getelem() == pt1) {
2175         // Comparing the same not escaping object.
2176         return _pcmp_eq;
2177       }
2178       Node* obj = ptn1->_node;
2179       // Comparing not escaping allocation.
2180       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2181           !ptset2.test(pt1)) {
2182         return _pcmp_neq; // This includes nullness check.
2183       }
2184     }
2185   } else if (ptset2.Size() == 1) {
2186     uint pt2 = ptset2.getelem();
2187     PointsToNode* ptn2 = ptnode_adr(pt2);
2188     if (ptn2->escape_state() == PointsToNode::NoEscape) {
2189       Node* obj = ptn2->_node;
2190       // Comparing not escaping allocation.
2191       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2192           !ptset1.test(pt2)) {
2193         return _pcmp_neq; // This includes nullness check.
2194       }
2195     }
2196   }
2197 
2198   if (!ptset1.disjoint(ptset2)) {
















2199     return NULL; // Sets are not disjoint
2200   }
2201 
2202   // Sets are disjoint.
2203   bool set1_has_unknown_ptr = ptset1.test(_phantom_object) != 0;
2204   bool set2_has_unknown_ptr = ptset2.test(_phantom_object) != 0;
2205   bool set1_has_null_ptr   = (ptset1.test(_oop_null) | ptset1.test(_noop_null)) != 0;
2206   bool set2_has_null_ptr   = (ptset2.test(_oop_null) | ptset2.test(_noop_null)) != 0;
2207 
2208   if (set1_has_unknown_ptr && set2_has_null_ptr ||
2209       set2_has_unknown_ptr && set1_has_null_ptr) {
2210     // Check nullness of unknown object.
2211     return NULL;
2212   }
2213 
2214   // Disjointness by itself is not sufficient since
2215   // alias analysis is not complete for escaped objects.
2216   // Disjoint sets are definitely unrelated only when
2217   // at least one set has only not escaping objects.
2218   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2219     bool has_only_non_escaping_alloc = true;
2220     for (VectorSetI i(&ptset1); i.test(); ++i) {
2221       uint pt = i.elem;
2222       PointsToNode* ptn = ptnode_adr(pt);
2223       Node* obj = ptn->_node;
2224       if (ptn->escape_state() != PointsToNode::NoEscape ||
2225           !(obj->is_Allocate() || obj->is_CallStaticJava())) {
2226         has_only_non_escaping_alloc = false;
2227         break;
2228       }
2229     }
2230     if (has_only_non_escaping_alloc) {
2231       return _pcmp_neq;
2232     }
2233   }
2234   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2235     bool has_only_non_escaping_alloc = true;
2236     for (VectorSetI i(&ptset2); i.test(); ++i) {
2237       uint pt = i.elem;
2238       PointsToNode* ptn = ptnode_adr(pt);
2239       Node* obj = ptn->_node;
2240       if (ptn->escape_state() != PointsToNode::NoEscape ||
2241           !(obj->is_Allocate() || obj->is_CallStaticJava())) {
2242         has_only_non_escaping_alloc = false;
2243         break;
2244       }
2245     }
2246     if (has_only_non_escaping_alloc) {
2247       return _pcmp_neq;
2248     }
2249   }
2250   return NULL;
2251 }
2252 
2253 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
2254     bool is_arraycopy = false;
2255     switch (call->Opcode()) {
2256 #ifdef ASSERT
2257     case Op_Allocate:
2258     case Op_AllocateArray:
2259     case Op_Lock:
2260     case Op_Unlock:
2261       assert(false, "should be done already");
2262       break;
2263 #endif
2264     case Op_CallLeafNoFP:
2265       is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
2266                       strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
2267       // fall through
2268     case Op_CallLeaf:
2269     {
2270       // Stub calls, objects do not escape but they are not scale replaceable.
2271       // Adjust escape state for outgoing arguments.
2272       const TypeTuple * d = call->tf()->domain();
2273       bool src_has_oops = false;
2274       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2275         const Type* at = d->field_at(i);
2276         Node *arg = call->in(i)->uncast();
2277         const Type *aat = phase->type(arg);
2278         PointsToNode::EscapeState arg_esc = ptnode_adr(arg->_idx)->escape_state();
2279         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
2280             (is_arraycopy || arg_esc < PointsToNode::ArgEscape)) {
2281 #ifdef ASSERT
2282           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2283                  aat->isa_ptr() != NULL, "expecting an Ptr");
2284           if (!(is_arraycopy ||
2285                 call->as_CallLeaf()->_name != NULL &&
2286                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
2287                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
2288           ) {
2289             call->dump();
2290             assert(false, "EA: unexpected CallLeaf");
2291           }
2292 #endif
2293           if (arg_esc < PointsToNode::ArgEscape) {
2294             set_escape_state(arg->_idx, PointsToNode::ArgEscape);
2295             Node* arg_base = arg;
2296             if (arg->is_AddP()) {
2297               //
2298               // The inline_native_clone() case when the arraycopy stub is called
2299               // after the allocation before Initialize and CheckCastPP nodes.
2300               // Or normal arraycopy for object arrays case.
2301               //
2302               // Set AddP's base (Allocate) as not scalar replaceable since
2303               // pointer to the base (with offset) is passed as argument.
2304               //
2305               arg_base = get_addp_base(arg);
2306               set_escape_state(arg_base->_idx, PointsToNode::ArgEscape);
2307             }
2308           }
2309 




2310           bool arg_has_oops = aat->isa_oopptr() &&
2311                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
2312                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
2313           if (i == TypeFunc::Parms) {
2314             src_has_oops = arg_has_oops;
2315           }
2316           //
2317           // src or dst could be j.l.Object when other is basic type array:
2318           //
2319           //   arraycopy(char[],0,Object*,0,size);
2320           //   arraycopy(Object*,0,char[],0,size);
2321           //
2322           // Do nothing special in such cases.
2323           //
2324           if (is_arraycopy && (i > TypeFunc::Parms) &&
2325               src_has_oops && arg_has_oops) {
2326             // Destination object's fields reference an unknown object.
2327             Node* arg_base = arg;
2328             if (arg->is_AddP()) {
2329               arg_base = get_addp_base(arg);




2330             }
2331             for (VectorSetI s(PointsTo(arg_base)); s.test(); ++s) {
2332               uint ps = s.elem;
2333               set_escape_state(ps, PointsToNode::ArgEscape);
2334               add_edge_from_fields(ps, _phantom_object, Type::OffsetBot);



2335             }
2336             // Conservatively all values in source object fields globally escape
2337             // since we don't know if values in destination object fields
2338             // escape (it could be traced but it is too expensive).
2339             Node* src = call->in(TypeFunc::Parms)->uncast();
2340             Node* src_base = src;
2341             if (src->is_AddP()) {
2342               src_base  = get_addp_base(src);
2343             }
2344             for (VectorSetI s(PointsTo(src_base)); s.test(); ++s) {
2345               uint ps = s.elem;
2346               set_escape_state(ps, PointsToNode::ArgEscape);
2347               // Use OffsetTop to indicate fields global escape.
2348               add_edge_from_fields(ps, _phantom_object, Type::OffsetTop);




2349             }
2350           }
2351         }
2352       }
2353       break;
2354     }
2355 
2356     case Op_CallStaticJava:
2357     // For a static call, we know exactly what method is being called.
2358     // Use bytecode estimator to record the call's escape affects
2359     {
2360       ciMethod *meth = call->as_CallJava()->method();
2361       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;





2362       // fall-through if not a Java method or no analyzer information
2363       if (call_analyzer != NULL) {
2364         const TypeTuple * d = call->tf()->domain();
2365         bool copy_dependencies = false;
2366         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2367           const Type* at = d->field_at(i);
2368           int k = i - TypeFunc::Parms;
2369           Node *arg = call->in(i)->uncast();
2370 









2371           if (at->isa_oopptr() != NULL &&
2372               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
2373 
2374             bool global_escapes = false;
2375             bool fields_escapes = false;
2376             if (!call_analyzer->is_arg_stack(k)) {
2377               // The argument global escapes, mark everything it could point to
2378               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2379               global_escapes = true;
2380             } else {

2381               if (!call_analyzer->is_arg_local(k)) {
2382                 // The argument itself doesn't escape, but any fields might
2383                 fields_escapes = true;
2384               }
2385               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
2386               copy_dependencies = true;
2387             }
2388 
2389             for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2390               uint pt = j.elem;
2391               if (global_escapes) {
2392                 // The argument global escapes, mark everything it could point to
2393                 set_escape_state(pt, PointsToNode::GlobalEscape);
2394                 add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2395               } else {
2396                 set_escape_state(pt, PointsToNode::ArgEscape);
2397                 if (fields_escapes) {
2398                   // The argument itself doesn't escape, but any fields might.
2399                   // Use OffsetTop to indicate such case.
2400                   add_edge_from_fields(pt, _phantom_object, Type::OffsetTop);
2401                 }
2402               }






2403             }
2404           }
2405         }
2406         if (copy_dependencies)
2407           call_analyzer->copy_dependencies(_compile->dependencies());
2408         break;
2409       }
2410     }
2411 
2412     default:
2413     // Fall-through here if not a Java method or no analyzer information
2414     // or some other type of call, assume the worst case: all arguments
2415     // globally escape.
2416     {
2417       // adjust escape state for  outgoing arguments
2418       const TypeTuple * d = call->tf()->domain();
2419       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2420         const Type* at = d->field_at(i);
2421         if (at->isa_oopptr() != NULL) {
2422           Node *arg = call->in(i)->uncast();
2423           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
2424           for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
2425             uint pt = j.elem;
2426             set_escape_state(pt, PointsToNode::GlobalEscape);
2427             add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
2428           }


2429         }
2430       }
2431     }
2432   }
2433 }
2434 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
2435   CallNode   *call = resproj->in(0)->as_Call();
2436   uint    call_idx = call->_idx;
2437   uint resproj_idx = resproj->_idx;
2438 
2439   switch (call->Opcode()) {
2440     case Op_Allocate:
2441     {
2442       Node *k = call->in(AllocateNode::KlassNode);
2443       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();

2444       assert(kt != NULL, "TypeKlassPtr  required.");
2445       ciKlass* cik = kt->klass();
2446 
2447       PointsToNode::EscapeState es;
2448       uint edge_to;
2449       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2450          !cik->is_instance_klass() || // StressReflectiveCode
2451           cik->as_instance_klass()->has_finalizer()) {
2452         es = PointsToNode::GlobalEscape;
2453         edge_to = _phantom_object; // Could not be worse
2454       } else {
2455         es = PointsToNode::NoEscape;
2456         edge_to = call_idx;
2457         assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
2458       }
2459       set_escape_state(call_idx, es);
2460       add_pointsto_edge(resproj_idx, edge_to);
2461       _processed.set(resproj_idx);
2462       break;
2463     }
2464 
2465     case Op_AllocateArray:
2466     {
2467 
2468       Node *k = call->in(AllocateNode::KlassNode);
2469       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
2470       assert(kt != NULL, "TypeKlassPtr  required.");
2471       ciKlass* cik = kt->klass();
2472 
2473       PointsToNode::EscapeState es;
2474       uint edge_to;
2475       if (!cik->is_array_klass()) { // StressReflectiveCode
2476         es = PointsToNode::GlobalEscape;
2477         edge_to = _phantom_object;
2478       } else {
2479         es = PointsToNode::NoEscape;
2480         edge_to = call_idx;
2481         assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
2482         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2483         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2484           // Not scalar replaceable if the length is not constant or too big.
2485           ptnode_adr(call_idx)->set_scalar_replaceable(false);
2486         }
2487       }
2488       set_escape_state(call_idx, es);
2489       add_pointsto_edge(resproj_idx, edge_to);
2490       _processed.set(resproj_idx);
2491       break;

2492     }





2493 
2494     case Op_CallStaticJava:
2495     // For a static call, we know exactly what method is being called.
2496     // Use bytecode estimator to record whether the call's return value escapes
2497     {
2498       bool done = true;
2499       const TypeTuple *r = call->tf()->range();
2500       const Type* ret_type = NULL;














2501 
2502       if (r->cnt() > TypeFunc::Parms)
2503         ret_type = r->field_at(TypeFunc::Parms);
2504 
2505       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
2506       //        _multianewarray functions return a TypeRawPtr.
2507       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
2508         _processed.set(resproj_idx);
2509         break;  // doesn't return a pointer type
2510       }
2511       ciMethod *meth = call->as_CallJava()->method();
2512       const TypeTuple * d = call->tf()->domain();
2513       if (meth == NULL) {
2514         // not a Java method, assume global escape
2515         set_escape_state(call_idx, PointsToNode::GlobalEscape);
2516         add_pointsto_edge(resproj_idx, _phantom_object);


2517       } else {
2518         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
2519         bool copy_dependencies = false;
2520 
2521         if (call_analyzer->is_return_allocated()) {
2522           // Returns a newly allocated unescaped object, simply
2523           // update dependency information.
2524           // Mark it as NoEscape so that objects referenced by
2525           // it's fields will be marked as NoEscape at least.
2526           set_escape_state(call_idx, PointsToNode::NoEscape);
2527           ptnode_adr(call_idx)->set_scalar_replaceable(false);
2528           // Fields values are unknown
2529           add_edge_from_fields(call_idx, _phantom_object, Type::OffsetBot);
2530           add_pointsto_edge(resproj_idx, call_idx);
2531           copy_dependencies = true;
2532         } else {
2533           // determine whether any arguments are returned
2534           set_escape_state(call_idx, PointsToNode::ArgEscape);
2535           bool ret_arg = false;
2536           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2537             const Type* at = d->field_at(i);
2538             if (at->isa_oopptr() != NULL) {
2539               Node *arg = call->in(i)->uncast();
2540 
2541               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
2542                 ret_arg = true;
2543                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
2544                 if (arg_esp->node_type() == PointsToNode::UnknownType)
2545                   done = false;
2546                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
2547                   add_pointsto_edge(resproj_idx, arg->_idx);
2548                 else
2549                   add_deferred_edge(resproj_idx, arg->_idx);
2550               }
2551             }
2552           }
2553           if (done) {
2554             copy_dependencies = true;
2555             // is_return_local() is true when only arguments are returned.
2556             if (!ret_arg || !call_analyzer->is_return_local()) {
2557               // Returns unknown object.
2558               add_pointsto_edge(resproj_idx, _phantom_object);
2559             }
2560           }
2561         }
2562         if (copy_dependencies)
2563           call_analyzer->copy_dependencies(_compile->dependencies());



2564       }
2565       if (done)
2566         _processed.set(resproj_idx);
2567       break;
2568     }
2569 
2570     default:
2571     // Some other type of call, assume the worst case that the
2572     // returned value, if any, globally escapes.
2573     {
2574       const TypeTuple *r = call->tf()->range();
2575       if (r->cnt() > TypeFunc::Parms) {
2576         const Type* ret_type = r->field_at(TypeFunc::Parms);

2577 
2578         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
2579         //        _multianewarray functions return a TypeRawPtr.
2580         if (ret_type->isa_ptr() != NULL) {
2581           set_escape_state(call_idx, PointsToNode::GlobalEscape);
2582           add_pointsto_edge(resproj_idx, _phantom_object);
2583         }
2584       }
2585       _processed.set(resproj_idx);
2586     }
2587   }
2588 }
2589 
2590 // Populate Connection Graph with Ideal nodes and create simple
2591 // connection graph edges (do not need to check the node_type of inputs
2592 // or to call PointsTo() to walk the connection graph).
2593 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
2594   if (_processed.test(n->_idx))
2595     return; // No need to redefine node's state.
2596 
2597   if (n->is_Call()) {




2598     // Arguments to allocation and locking don't escape.
2599     if (n->is_Allocate()) {
2600       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
2601       record_for_optimizer(n);
2602     } else if (n->is_Lock() || n->is_Unlock()) {
2603       // Put Lock and Unlock nodes on IGVN worklist to process them during
2604       // the first IGVN optimization when escape information is still available.
2605       record_for_optimizer(n);
2606       _processed.set(n->_idx);


2607     } else {





2608       // Don't mark as processed since call's arguments have to be processed.
2609       PointsToNode::NodeType nt = PointsToNode::UnknownType;
2610       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
2611 
2612       // Check if a call returns an object.
2613       const TypeTuple *r = n->as_Call()->tf()->range();
2614       if (r->cnt() > TypeFunc::Parms &&
2615           r->field_at(TypeFunc::Parms)->isa_ptr() &&
2616           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2617         nt = PointsToNode::JavaObject;
2618         if (!n->is_CallStaticJava()) {
2619           // Since the called mathod is statically unknown assume
2620           // the worst case that the returned value globally escapes.
2621           es = PointsToNode::GlobalEscape;
2622         }
2623       }
2624       add_node(n, nt, es, false);
2625     }
2626     return;
2627   }
2628 
2629   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2630   // ThreadLocal has RawPrt type.
2631   switch (n->Opcode()) {








2632     case Op_AddP:
2633     {
2634       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
















2635       break;
2636     }
2637     case Op_CastX2P:
2638     { // "Unsafe" memory access.
2639       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);





2640       break;
2641     }
2642     case Op_CastPP:
2643     case Op_CheckCastPP:
2644     case Op_EncodeP:
2645     case Op_DecodeN:
2646     {
2647       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2648       int ti = n->in(1)->_idx;
2649       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2650       if (nt == PointsToNode::UnknownType) {
2651         _delayed_worklist.push(n); // Process it later.
2652         break;
2653       } else if (nt == PointsToNode::JavaObject) {
2654         add_pointsto_edge(n->_idx, ti);
2655       } else {
2656         add_deferred_edge(n->_idx, ti);
2657       }
2658       _processed.set(n->_idx);
2659       break;
2660     }
2661     case Op_ConP:
2662     {
2663       // assume all pointer constants globally escape except for null
2664       PointsToNode::EscapeState es;
2665       if (phase->type(n) == TypePtr::NULL_PTR)
2666         es = PointsToNode::NoEscape;
2667       else
2668         es = PointsToNode::GlobalEscape;
2669 
2670       add_node(n, PointsToNode::JavaObject, es, true);
2671       break;
2672     }
2673     case Op_ConN:
2674     {
2675       // assume all narrow oop constants globally escape except for null
2676       PointsToNode::EscapeState es;
2677       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
2678         es = PointsToNode::NoEscape;
2679       else
2680         es = PointsToNode::GlobalEscape;
2681 
2682       add_node(n, PointsToNode::JavaObject, es, true);
2683       break;
2684     }
2685     case Op_CreateEx:
2686     {
2687       // assume that all exception objects globally escape
2688       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2689       break;
2690     }
2691     case Op_LoadKlass:
2692     case Op_LoadNKlass:
2693     {
2694       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
2695       break;
2696     }
2697     case Op_LoadP:
2698     case Op_LoadN:
2699     {
2700       const Type *t = phase->type(n);
2701       if (t->make_ptr() == NULL) {
2702         _processed.set(n->_idx);
2703         return;
2704       }
2705       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2706       break;
2707     }
2708     case Op_Parm:
2709     {
2710       _processed.set(n->_idx); // No need to redefine it state.
2711       uint con = n->as_Proj()->_con;
2712       if (con < TypeFunc::Parms)
2713         return;
2714       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
2715       if (t->isa_ptr() == NULL)
2716         return;
2717       // We have to assume all input parameters globally escape
2718       // (Note: passing 'false' since _processed is already set).
2719       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
2720       break;
2721     }
2722     case Op_PartialSubtypeCheck:
2723     { // Produces Null or notNull and is used in CmpP.
2724       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2725       break;
2726     }
2727     case Op_Phi:
2728     {
2729       const Type *t = n->as_Phi()->type();
2730       if (t->make_ptr() == NULL) {
2731         // nothing to do if not an oop or narrow oop
2732         _processed.set(n->_idx);
2733         return;
2734       }
2735       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2736       uint i;
2737       for (i = 1; i < n->req() ; i++) {
2738         Node* in = n->in(i);
2739         if (in == NULL)
2740           continue;  // ignore NULL
2741         in = in->uncast();
2742         if (in->is_top() || in == n)
2743           continue;  // ignore top or inputs which go back this node
2744         int ti = in->_idx;
2745         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2746         if (nt == PointsToNode::UnknownType) {
2747           break;
2748         } else if (nt == PointsToNode::JavaObject) {
2749           add_pointsto_edge(n->_idx, ti);
2750         } else {
2751           add_deferred_edge(n->_idx, ti);
2752         }
2753       }
2754       if (i >= n->req())
2755         _processed.set(n->_idx);
2756       else
2757         _delayed_worklist.push(n);
2758       break;
2759     }
2760     case Op_Proj:
2761     {
2762       // we are only interested in the oop result projection from a call
2763       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
2764         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
2765         assert(r->cnt() > TypeFunc::Parms, "sanity");
2766         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
2767           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
2768           int ti = n->in(0)->_idx;
2769           // The call may not be registered yet (since not all its inputs are registered)
2770           // if this is the projection from backbranch edge of Phi.
2771           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
2772             process_call_result(n->as_Proj(), phase);
2773           }
2774           if (!_processed.test(n->_idx)) {
2775             // The call's result may need to be processed later if the call
2776             // returns it's argument and the argument is not processed yet.
2777             _delayed_worklist.push(n);
2778           }
2779           break;
2780         }
2781       }
2782       _processed.set(n->_idx);
2783       break;
2784     }
2785     case Op_Return:
2786     {
2787       if( n->req() > TypeFunc::Parms &&
2788           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
2789         // Treat Return value as LocalVar with GlobalEscape escape state.
2790         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
2791         int ti = n->in(TypeFunc::Parms)->_idx;
2792         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2793         if (nt == PointsToNode::UnknownType) {
2794           _delayed_worklist.push(n); // Process it later.
2795           break;
2796         } else if (nt == PointsToNode::JavaObject) {
2797           add_pointsto_edge(n->_idx, ti);
2798         } else {
2799           add_deferred_edge(n->_idx, ti);
2800         }
2801       }
2802       _processed.set(n->_idx);
2803       break;
2804     }
2805     case Op_StoreP:
2806     case Op_StoreN:
2807     {
2808       const Type *adr_type = phase->type(n->in(MemNode::Address));
2809       adr_type = adr_type->make_ptr();
2810       if (adr_type->isa_oopptr()) {
2811         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2812       } else {
2813         Node* adr = n->in(MemNode::Address);
2814         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
2815             adr->in(AddPNode::Address)->is_Proj() &&
2816             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
2817           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2818           // We are computing a raw address for a store captured
2819           // by an Initialize compute an appropriate address type.
2820           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
2821           assert(offs != Type::OffsetBot, "offset must be a constant");
2822         } else {
2823           _processed.set(n->_idx);
2824           return;
2825         }
2826       }
2827       break;
2828     }
2829     case Op_StorePConditional:
2830     case Op_CompareAndSwapP:
2831     case Op_CompareAndSwapN:
2832     {
2833       const Type *adr_type = phase->type(n->in(MemNode::Address));
2834       adr_type = adr_type->make_ptr();
2835       if (adr_type->isa_oopptr()) {
2836         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2837       } else {
2838         _processed.set(n->_idx);
2839         return;
2840       }
2841       break;
2842     }
2843     case Op_AryEq:
2844     case Op_StrComp:
2845     case Op_StrEquals:
2846     case Op_StrIndexOf:
2847     {
2848       // char[] arrays passed to string intrinsics are not scalar replaceable.
2849       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
2850       break;
2851     }
2852     case Op_ThreadLocal:
2853     {
2854       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
2855       break;
2856     }
2857     default:
2858       ;
2859       // nothing to do
2860   }
2861   return;
2862 }
2863 
2864 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
2865   uint n_idx = n->_idx;
2866   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
2867 
2868   // Don't set processed bit for AddP, LoadP, StoreP since
2869   // they may need more then one pass to process.
2870   // Also don't mark as processed Call nodes since their
2871   // arguments may need more then one pass to process.
2872   if (_processed.test(n_idx))
2873     return; // No need to redefine node's state.
2874 
2875   if (n->is_Call()) {
2876     CallNode *call = n->as_Call();
2877     process_call_arguments(call, phase);
2878     return;
2879   }
2880 
2881   switch (n->Opcode()) {
2882     case Op_AddP:
2883     {
2884       Node *base = get_addp_base(n);
2885       int offset = address_offset(n, phase);
2886       // Create a field edge to this node from everything base could point to.
2887       for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
2888         uint pt = i.elem;
2889         add_field_edge(pt, n_idx, offset);
2890       }
2891       break;
2892     }
2893     case Op_CastX2P:

2894     {
2895       assert(false, "Op_CastX2P");
2896       break;
2897     }
2898     case Op_CastPP:
2899     case Op_CheckCastPP:
2900     case Op_EncodeP:
2901     case Op_DecodeN:
2902     {
2903       int ti = n->in(1)->_idx;
2904       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
2905       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
2906         add_pointsto_edge(n_idx, ti);
2907       } else {
2908         add_deferred_edge(n_idx, ti);
2909       }
2910       _processed.set(n_idx);
2911       break;
2912     }
2913     case Op_ConP:
2914     {
2915       assert(false, "Op_ConP");
2916       break;
2917     }
2918     case Op_ConN:
2919     {
2920       assert(false, "Op_ConN");
2921       break;
2922     }
2923     case Op_CreateEx:
2924     {




2925       assert(false, "Op_CreateEx");

2926       break;
2927     }
2928     case Op_LoadKlass:
2929     case Op_LoadNKlass:
2930     {




2931       assert(false, "Op_LoadKlass");

2932       break;
2933     }
2934     case Op_LoadP:
2935     case Op_LoadN:

2936     {
2937       const Type *t = phase->type(n);












2938 #ifdef ASSERT
2939       if (t->make_ptr() == NULL)

2940         assert(false, "Op_LoadP");
2941 #endif
2942 
2943       Node* adr = n->in(MemNode::Address)->uncast();
2944       Node* adr_base;
2945       if (adr->is_AddP()) {
2946         adr_base = get_addp_base(adr);
2947       } else {
2948         adr_base = adr;
2949       }
2950 
2951       // For everything "adr_base" could point to, create a deferred edge from
2952       // this node to each field with the same offset.
2953       int offset = address_offset(adr, phase);
2954       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
2955         uint pt = i.elem;
2956         if (adr->is_AddP()) {
2957           // Add field edge if it is missing.
2958           add_field_edge(pt, adr->_idx, offset);
2959         }
2960         add_deferred_edge_to_fields(n_idx, pt, offset);
2961       }
2962       break;
2963     }
2964     case Op_Parm:
2965     {




2966       assert(false, "Op_Parm");

2967       break;
2968     }
2969     case Op_PartialSubtypeCheck:
2970     {







2971       assert(false, "Op_PartialSubtypeCheck");

2972       break;
2973     }
2974     case Op_Phi:
2975     {
2976 #ifdef ASSERT
2977       const Type *t = n->as_Phi()->type();
2978       if (t->make_ptr() == NULL)
2979         assert(false, "Op_Phi");
2980 #endif
2981       for (uint i = 1; i < n->req() ; i++) {






2982         Node* in = n->in(i);
2983         if (in == NULL)
2984           continue;  // ignore NULL
2985         in = in->uncast();
2986         if (in->is_top() || in == n)
2987           continue;  // ignore top or inputs which go back this node
2988         int ti = in->_idx;
2989         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
2990         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
2991         if (nt == PointsToNode::JavaObject) {
2992           add_pointsto_edge(n_idx, ti);
2993         } else {
2994           add_deferred_edge(n_idx, ti);
2995         }
2996       }
2997       _processed.set(n_idx);





2998       break;
2999     }
3000     case Op_Proj:
3001     {
3002       // we are only interested in the oop result projection from a call
3003       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
3004         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
3005                "all nodes should be registered");
3006         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
3007         assert(r->cnt() > TypeFunc::Parms, "sanity");
3008         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
3009           process_call_result(n->as_Proj(), phase);
3010           assert(_processed.test(n_idx), "all call results should be processed");
3011           break;
3012         }
3013       }
3014       assert(false, "Op_Proj");


3015       break;
3016     }

3017     case Op_Return:
3018     {





3019 #ifdef ASSERT
3020       if( n->req() <= TypeFunc::Parms ||
3021           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
3022         assert(false, "Op_Return");
3023       }
3024 #endif
3025       int ti = n->in(TypeFunc::Parms)->_idx;
3026       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
3027       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
3028         add_pointsto_edge(n_idx, ti);
3029       } else {
3030         add_deferred_edge(n_idx, ti);
3031       }
3032       _processed.set(n_idx);
3033       break;
3034     }
3035     case Op_StoreP:
3036     case Op_StoreN:
3037     case Op_StorePConditional:
3038     case Op_CompareAndSwapP:
3039     case Op_CompareAndSwapN:
3040     {
3041       Node *adr = n->in(MemNode::Address);
3042       const Type *adr_type = phase->type(adr)->make_ptr();






3043 #ifdef ASSERT
3044       if (!adr_type->isa_oopptr())
3045         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");




3046 #endif


















3047 


3048       assert(adr->is_AddP(), "expecting an AddP");
3049       Node *adr_base = get_addp_base(adr);
3050       Node *val = n->in(MemNode::ValueIn)->uncast();
3051       int offset = address_offset(adr, phase);
3052       // For everything "adr_base" could point to, create a deferred edge
3053       // to "val" from each field with the same offset.
3054       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
3055         uint pt = i.elem;
3056         // Add field edge if it is missing.
3057         add_field_edge(pt, adr->_idx, offset);
3058         add_edge_from_fields(pt, val->_idx, offset);
3059       }








3060       break;
3061     }
3062     case Op_AryEq:
3063     case Op_StrComp:
3064     case Op_StrEquals:
3065     case Op_StrIndexOf:
3066     {





3067       // char[] arrays passed to string intrinsic do not escape but
3068       // they are not scalar replaceable. Adjust escape state for them.
3069       // Start from in(2) edge since in(1) is memory edge.
3070       for (uint i = 2; i < n->req(); i++) {
3071         Node* adr = n->in(i)->uncast();
3072         const Type *at = phase->type(adr);
3073         if (!adr->is_top() && at->isa_ptr()) {
3074           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
3075                  at->isa_ptr() != NULL, "expecting an Ptr");
3076           if (adr->is_AddP()) {
3077             adr = get_addp_base(adr);
3078           }
3079           // Mark as ArgEscape everything "adr" could point to.
3080           set_escape_state(adr->_idx, PointsToNode::ArgEscape);

3081         }
3082       }
3083       _processed.set(n_idx);
3084       break;
3085     }
3086     case Op_ThreadLocal:
3087     {



3088       assert(false, "Op_ThreadLocal");

3089       break;
3090     }
3091     default:
3092       // This method should be called only for EA specific nodes.



3093       ShouldNotReachHere();
3094   }


3095 }
3096 
3097 #ifndef PRODUCT
3098 void ConnectionGraph::dump() {
3099   bool first = true;





3100 
3101   uint size = nodes_size();
3102   for (uint ni = 0; ni < size; ni++) {
3103     PointsToNode *ptn = ptnode_adr(ni);
3104     PointsToNode::NodeType ptn_type = ptn->node_type();


3105 
3106     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)















































3107       continue;
3108     PointsToNode::EscapeState es = escape_state(ptn->_node);
3109     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3110       if (first) {
3111         tty->cr();
3112         tty->print("======== Connection graph for ");
3113         _compile->method()->print_short_name();
3114         tty->cr();
3115         first = false;
3116       }
3117       tty->print("%6d ", ni);
3118       ptn->dump();
3119       // Print all locals which reference this allocation
3120       for (uint li = ni; li < size; li++) {
3121         PointsToNode *ptn_loc = ptnode_adr(li);
3122         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
3123         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
3124              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
3125           ptnode_adr(li)->dump(false);

3126         }
3127       }
3128       if (Verbose) {
3129         // Print all fields which reference this allocation
3130         for (uint i = 0; i < ptn->edge_count(); i++) {
3131           uint ei = ptn->edge_target(i);
3132           ptnode_adr(ei)->dump(false);
3133         }
3134       }
3135       tty->cr();
3136     }
3137   }
3138 }
3139 #endif


  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/bcEscapeAnalyzer.hpp"
  27 #include "libadt/vectset.hpp"
  28 #include "memory/allocation.hpp"
  29 #include "opto/c2compiler.hpp"
  30 #include "opto/callnode.hpp"
  31 #include "opto/cfgnode.hpp"
  32 #include "opto/compile.hpp"
  33 #include "opto/escape.hpp"
  34 #include "opto/phaseX.hpp"
  35 #include "opto/rootnode.hpp"
  36 
























































  37 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
  38   _nodes(C->comp_arena(), C->unique(), C->unique(), NULL),




  39   _collecting(true),
  40   _verify(false),
  41   _compile(C),
  42   _igvn(igvn),
  43   _node_map(C->comp_arena()) {
  44 
  45   add_java_object(C->top(), PointsToNode::GlobalEscape);
  46   phantom_obj = ptnode_adr(C->top()->_idx)->as_JavaObject();
  47 
  48   // Add ConP(#NULL) and ConN(#NULL) nodes.
  49   Node* oop_null = igvn->zerocon(T_OBJECT);
  50   assert(oop_null->_idx < nodes_size(), "should be created already");
  51   add_java_object(oop_null, PointsToNode::NoEscape);
  52   null_obj = ptnode_adr(oop_null->_idx)->as_JavaObject();
  53 
  54   if (UseCompressedOops) {
  55     Node* noop_null = igvn->zerocon(T_NARROWOOP);
  56     assert(noop_null->_idx < nodes_size(), "should be created already");
  57     map_ideal_node(noop_null, null_obj);



  58   }
  59   _pcmp_neq = NULL; // Should be initialized
  60   _pcmp_eq  = NULL;
  61 }
  62 
  63 // Connection Graph constuction functions.


  64 
  65 void ConnectionGraph::add_local_var(Node *n, PointsToNode::EscapeState es) {
  66   PointsToNode* ptadr = _nodes.at(n->_idx);
  67   if (ptadr != NULL) {
  68     assert(ptadr->is_LocalVar() && ptadr->ideal_node() == n, "sanity");

  69     return;


  70   }
  71   ptadr = new LocalVarNode(n, es);
  72   _nodes.at_put(n->_idx, ptadr);
  73 }
  74 
  75 void ConnectionGraph::add_java_object(Node *n, PointsToNode::EscapeState es) {
  76   PointsToNode* ptadr = _nodes.at(n->_idx);
  77   if (ptadr != NULL) {
  78     assert(ptadr->is_JavaObject() && ptadr->ideal_node() == n, "sanity");
  79     return;




















  80   }
  81   ptadr = new JavaObjectNode(n, es);
  82   _nodes.at_put(n->_idx, ptadr);

  83 }
  84 
  85 void ConnectionGraph::add_field(Node *n, PointsToNode::EscapeState es, int offset) {
  86   PointsToNode* ptadr = _nodes.at(n->_idx);
  87   if (ptadr != NULL) {
  88     assert(ptadr->is_Field() && ptadr->ideal_node() == n, "sanity");
  89     return;
  90   }
  91   bool is_oop = is_oop_field(n, offset);
  92   FieldNode* field = new FieldNode(n, es, offset, is_oop);
  93   _nodes.at_put(n->_idx, field);






  94 }
  95 
  96 void ConnectionGraph::add_arraycopy(Node *n, PointsToNode::EscapeState es,
  97                                     PointsToNode* src, PointsToNode* dst) {
  98   assert(!src->is_Field() && !dst->is_Field(), "only for JavaObject and LocalVar");
  99   assert((src != null_obj) && (dst != null_obj), "not for ConP NULL");
 100   PointsToNode* ptadr = _nodes.at(n->_idx);
 101   if (ptadr != NULL) {
 102     assert(ptadr->is_Arraycopy() && ptadr->ideal_node() == n, "sanity");
 103     return;
 104   }
 105   ptadr = new ArraycopyNode(n, es);
 106   _nodes.at_put(n->_idx, ptadr);
 107   // Add edge from arraycopy node to source object.
 108   (void)add_edge(ptadr, src);
 109   src->set_arraycopy_src();
 110   // Add edge from destination object to arraycopy node.
 111   (void)add_edge(dst, ptadr);
 112   dst->set_arraycopy_dst();
 113 }
 114 
 115 bool ConnectionGraph::is_oop_field(Node* n, int offset) {
 116   const Type* adr_type = n->as_AddP()->bottom_type();
 117   BasicType bt = T_INT;
 118   if (offset == Type::OffsetBot) {
 119     // Check only oop fields.
 120     if (!adr_type->isa_aryptr() ||
 121         (adr_type->isa_aryptr()->klass() == NULL) ||
 122          adr_type->isa_aryptr()->klass()->is_obj_array_klass()) {
 123       // OffsetBot is used to reference array's element. Ignore first AddP.
 124       if (find_second_addp(n, n->in(AddPNode::Base)) == NULL) {
 125         bt = T_OBJECT;
 126       }
 127     }
 128   } else if (offset != oopDesc::klass_offset_in_bytes()) {
 129     if (adr_type->isa_instptr()) {
 130       ciField* field = _compile->alias_type(adr_type->isa_instptr())->field();
 131       if (field != NULL) {
 132         bt = field->layout_type();
 133       } else {
 134         // Ignore non field load (for example, klass load)
 135       }
 136     } else if (adr_type->isa_aryptr()) {
 137       if (offset == arrayOopDesc::length_offset_in_bytes()) {
 138         // Ignore array length load.
 139       } else if (find_second_addp(n, n->in(AddPNode::Base)) != NULL) {
 140         // Ignore first AddP.
 141       } else {
 142         const Type* elemtype = adr_type->isa_aryptr()->elem();
 143         bt = elemtype->array_element_basic_type();
 144       }
 145     } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
 146       // Allocation initialization, ThreadLocal field access, unsafe access
 147       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 148         int opcode = n->fast_out(i)->Opcode();
 149         if (opcode == Op_StoreP || opcode == Op_LoadP ||
 150             opcode == Op_StoreN || opcode == Op_LoadN) {
 151           bt = T_OBJECT;
 152         }
 153       }
 154     }
 155   }
 156   return (bt == T_OBJECT || bt == T_NARROWOOP || bt == T_ARRAY);
 157 }
 158 
 159 // Add all references to JavaObject node by walking over all uses.
 160 int ConnectionGraph::add_java_object_edges(JavaObjectNode* jobj,
 161                                             bool populate_worklist) {
 162   int new_edges = 0;
 163   if (populate_worklist) {
 164     // Populate _worklist by uses of jobj's uses.
 165     uint count = jobj->use_count();
 166     for (uint i = 0; i < count; i++) {
 167       PointsToNode* use = jobj->use(i);
 168       if (use->is_Arraycopy())
 169         continue;
 170 
 171       add_uses_to_worklist(use);
 172       if (use->is_Field() && use->as_Field()->is_oop()) {
 173         // Put on worklist all field's uses (loads) and
 174         // related field nodes (same base and offset).
 175         add_field_uses_to_worklist(use->as_Field());
 176       }
 177     }
 178   }
 179 
 180   while(_worklist.length() > 0) {
 181     PointsToNode* use = _worklist.pop();


 182 
 183     if (PointsToNode::is_base_use(use)) {
 184       // Add reference from jobj to field and from field to jobj (field's base).
 185       use = PointsToNode::get_use_node(use)->as_Field();
 186       if (add_base(use->as_Field(), jobj))
 187         new_edges++;
 188       continue;
 189     }
 190     assert(!use->is_JavaObject(), "sanity");
 191 
 192     if (use->is_Arraycopy()) {
 193       if (jobj == null_obj) // NULL object does not have field edges
 194         continue;

 195 
 196       // Added edge from Arraycopy node to arraycopy's source java object
 197       if (add_edge(use, jobj)) {
 198         jobj->set_arraycopy_src();
 199         new_edges++;
 200       }
 201       // and stop here.
 202       continue;
 203     }
 204 
 205     if (!add_edge(use, jobj))
 206       continue; // No new edge added, there was such edge already.
 207 
 208     new_edges++;
 209 
 210     if (use->is_LocalVar()) {
 211       add_uses_to_worklist(use);
 212       if (use->arraycopy_dst()) {
 213         uint ecnt = use->edge_count();
 214         for (uint j = 0; j < ecnt; j++) {
 215           PointsToNode* e = use->edge(j);
 216           if (e->is_Arraycopy()) {
 217             if (jobj == null_obj) // NULL object does not have field edges
 218               continue;
 219             // Add edge from arraycopy's destination java object to Arraycopy node.
 220             if (add_edge(jobj, e)) {
 221               new_edges++;
 222               jobj->set_arraycopy_dst();
 223             }
 224           }
 225         }
 226       }
 227     } else {
 228       // Added new edge to stored in field values.
 229       // Put on worklist all field's uses (loads) and
 230       // related field nodes (same base and offset).
 231       add_field_uses_to_worklist(use->as_Field());
 232     }
 233   }
 234   return new_edges;
 235 }
 236 
 237 // Put on worklist all related field nodes.
 238 void ConnectionGraph::add_field_uses_to_worklist(FieldNode* field) {
 239   assert(field->is_oop(), "sanity");
 240   int offset = field->offset();
 241   add_uses_to_worklist(field);
 242 
 243   // Loop over all bases of this field and push on worklist Field nodes
 244   // with the same offset and base (since they may reference the same field).
 245   uint bcnt = field->base_count();
 246   for (uint i = 0; i < bcnt; i++) {
 247     PointsToNode* base = field->base(i);
 248     add_fields_to_worklist(field, base);
 249 
 250     // Check if the base was source object of arraycopy and go over arraycopy's
 251     // destination objects since values stored to a field of source object are
 252     // accessable by uses (loads) of fields of destination objects.
 253     if (base->arraycopy_src()) {
 254       uint ucnt = base->use_count();
 255       for (uint j = 0; j < ucnt; j++) {
 256         PointsToNode* arycp = base->use(j);
 257         if (arycp->is_Arraycopy()) {
 258           uint acnt = arycp->use_count();
 259           for (uint k = 0; k < acnt; k++) {
 260             PointsToNode* abase = arycp->use(k);
 261             if (abase->arraycopy_dst() && abase != base) {
 262               // Look for the same arracopy reference.
 263               add_fields_to_worklist(field, abase);
 264             }






 265           }
 266         }
 267       }
 268     }
 269   }
 270 }

 271 
 272 // Put on worklist all related field nodes.
 273 void ConnectionGraph::add_fields_to_worklist(FieldNode* field, PointsToNode* base) {
 274   int offset = field->offset();
 275   if (base->is_LocalVar()) {
 276     uint fcnt = base->use_count();
 277     for (uint j = 0; j < fcnt; j++) {
 278       PointsToNode* f = base->use(j);
 279       if (PointsToNode::is_base_use(f)) { // Field
 280         f = PointsToNode::get_use_node(f);
 281         if (f == field || !f->as_Field()->is_oop())
 282           continue;
 283         int offs = f->as_Field()->offset();
 284         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
 285           add_to_worklist(f);
 286         }
 287       }
 288     }
 289   } else {
 290     assert(base->is_JavaObject(), "sanity");
 291     if (// Skip phantom_object since it is only used to indicate that
 292         // this field's content globally escapes.
 293         (base != phantom_obj) &&
 294         // NULL object node does not have fields.
 295         (base != null_obj)) {
 296       uint fcnt = base->edge_count();
 297       for (uint j = 0; j < fcnt; j++) {
 298         PointsToNode* f = base->edge(j);
 299         // Skip arraycopy edge since store to destination object field
 300         // does not update value in source object field.
 301         if (f->is_Arraycopy()) {
 302           assert(base->arraycopy_dst(), "sanity");
 303           continue;
 304         }
 305         if (f == field || !f->as_Field()->is_oop())
 306           continue;
 307         int offs = f->as_Field()->offset();
 308         if (offs == offset || offset == Type::OffsetBot || offs == Type::OffsetBot) {
 309           add_to_worklist(f);
 310         }




 311       }
 312     }
 313   }
 314 }
 315 
 316 // Returns unique pointed java object or NULL.
 317 JavaObjectNode* ConnectionGraph::unique_java_object(Node *n) {
 318   assert(!_collecting, "should not call when contructed graph");


 319 
 320   // If the node was created after the escape computation we can't answer.
 321   uint idx = n->_idx;
 322   if (idx >= nodes_size())
 323     return NULL;

 324 
 325   PointsToNode* ptn = ptnode_adr(idx);
 326   if (ptn->is_JavaObject()) {
 327     return ptn->as_JavaObject();










 328   }
 329 
 330   assert(ptn->is_LocalVar(), "sanity");
 331   // Check all java objects it points to.
 332   uint count = ptn->edge_count();
 333   JavaObjectNode* jobj = NULL;
 334   for (uint i = 0; i < count; i++) {
 335     PointsToNode* e = ptn->edge(i);
 336     if (e->is_JavaObject()) {
 337       if (jobj == NULL) {
 338         jobj = e->as_JavaObject();
 339       } else if (jobj != e) {
 340         return NULL;
 341       }
 342     }
 343   }
 344   return jobj;
 345 }





 346 
 347 // Return true if nodes points only to non-escaped allocations.
 348 bool PointsToNode::not_escaped_allocation() {
 349   if (is_JavaObject()) {
 350     Node* n = ideal_node();
 351     if (n->is_Allocate() || n->is_CallStaticJava()) {
 352       return (escape_state() == PointsToNode::NoEscape);
 353     } else {
 354       return false;
 355     }
 356   }
 357   assert(is_LocalVar(), "sanity");
 358   // Check all java objects it points to.
 359   uint count = edge_count();
 360   for (uint i = 0; i < count; i++) {
 361     PointsToNode* e = edge(i);
 362     if (e->is_JavaObject()) {
 363       Node* n = e->ideal_node();
 364       if ((e->escape_state() != PointsToNode::NoEscape) ||
 365           !(n->is_Allocate() || n->is_CallStaticJava())) {
 366         return false;
 367       }













 368     }
 369   }
 370   return true;
 371 }
 372 
 373 // Return true if we know the node does not escape globally.
 374 bool ConnectionGraph::not_global_escape(Node *n) {
 375   assert(!_collecting, "should not call during graph construction");
 376 
 377   // If the node was created after the escape computation we can't answer.
 378   uint idx = n->_idx;
 379   if (idx >= nodes_size())
 380     return false;
 381 
 382   PointsToNode* ptn = ptnode_adr(idx);
 383   PointsToNode::EscapeState es = ptn->escape_state();
 384 
 385   // If we have already computed a value, return it.
 386   if (es >= PointsToNode::GlobalEscape)
 387     return false;
 388 
 389   if (ptn->is_JavaObject()) {
 390     return true; // (es < PointsToNode::GlobalEscape);
 391   }
 392 
 393   assert(ptn->is_LocalVar(), "sanity");
 394   // Check all java objects it points to.
 395   uint count = ptn->edge_count();
 396   for (uint i = 0; i < count; i++) {
 397     if (ptn->edge(i)->escape_state() >= PointsToNode::GlobalEscape)
 398       return false;

 399   }
 400   return true;
 401 }
 402 
 403 
 404 // Helper functions
 405 
 406 // Return true if this node points to specified node or nodes it points to.
 407 bool PointsToNode::points_to(JavaObjectNode* ptn) const {
 408   if (this->is_JavaObject())
 409     return (this == ptn);
 410 
 411   assert(this->is_LocalVar(), "sanity");
 412 
 413   uint count = this->edge_count();
 414   for (uint i = 0; i < count; i++) {
 415     PointsToNode* e = this->edge(i);
 416     if (e == ptn)
 417       return true;
 418   }
 419   return false;
 420 }
 421 
 422 // Return true if one node points to an other.
 423 bool PointsToNode::meet(PointsToNode* ptn) {
 424   if (this == ptn)
 425     return true;
 426 
 427   if (ptn->is_JavaObject())
 428     return this->points_to(ptn->as_JavaObject());
 429 
 430   if (this->is_JavaObject())
 431     return ptn->points_to(this->as_JavaObject());
 432 
 433   assert(this->is_LocalVar() && ptn->is_LocalVar(), "sanity");
 434 
 435   uint this_count = this->edge_count();
 436   uint  ptn_count =  ptn->edge_count();
 437   for (uint i = 0; i < this_count; i++) {
 438     PointsToNode* this_e = this->edge(i);
 439     for (uint j = 0; j < ptn_count; j++) {
 440       PointsToNode* ptn_e = ptn->edge(j);
 441       if (this_e == ptn_e)
 442         return true;
 443     }
 444   }
 445   return false;
 446 }
 447 
 448 #ifdef ASSERT
 449 // Return true if bases points to this java object.
 450 bool FieldNode::has_base(JavaObjectNode* jobj) const {
 451   uint count = this->base_count();
 452   for (uint i = 0; i < count; i++) {
 453     PointsToNode* b = this->base(i);
 454     if (b == jobj)
 455       return true;
 456   }
 457   return false;
 458 }
 459 #endif
 460 
 461 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
 462   const Type *adr_type = phase->type(adr);
 463   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
 464       adr->in(AddPNode::Address)->is_Proj() &&
 465       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
 466     // We are computing a raw address for a store captured by an Initialize
 467     // compute an appropriate address type. AddP cases #3 and #5 (see below).
 468     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
 469     assert(offs != Type::OffsetBot ||
 470            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
 471            "offset must be a constant or it is initialization of array");
 472     return offs;
 473   }
 474   const TypePtr *t_ptr = adr_type->isa_ptr();
 475   assert(t_ptr != NULL, "must be a pointer type");
 476   return t_ptr->offset();



















 477 }
 478 
 479 Node* ConnectionGraph::get_addp_base(Node *addp) {


 480   assert(addp->is_AddP(), "must be AddP");
 481   //
 482   // AddP cases for Base and Address inputs:
 483   // case #1. Direct object's field reference:
 484   //     Allocate
 485   //       |
 486   //     Proj #5 ( oop result )
 487   //       |
 488   //     CheckCastPP (cast to instance type)
 489   //      | |
 490   //     AddP  ( base == address )
 491   //
 492   // case #2. Indirect object's field reference:
 493   //      Phi
 494   //       |
 495   //     CastPP (cast to instance type)
 496   //      | |
 497   //     AddP  ( base == address )
 498   //
 499   // case #3. Raw object's field reference for Initialize node:


 522   //
 523   // case #6. Constant Pool, ThreadLocal, CastX2P or
 524   //          Raw object's field reference:
 525   //      {ConP, ThreadLocal, CastX2P, raw Load}
 526   //  top   |
 527   //     \  |
 528   //     AddP  ( base == top )
 529   //
 530   // case #7. Klass's field reference.
 531   //      LoadKlass
 532   //       | |
 533   //       AddP  ( base == address )
 534   //
 535   // case #8. narrow Klass's field reference.
 536   //      LoadNKlass
 537   //       |
 538   //      DecodeN
 539   //       | |
 540   //       AddP  ( base == address )
 541   //
 542   Node *base = addp->in(AddPNode::Base);
 543   if (base->uncast()->is_top()) { // The AddP case #3 and #6.
 544     base = addp->in(AddPNode::Address);
 545     while (base->is_AddP()) {
 546       // Case #6 (unsafe access) may have several chained AddP nodes.
 547       assert(base->in(AddPNode::Base)->uncast()->is_top(), "expected unsafe access address only");
 548       base = base->in(AddPNode::Address);
 549     }
 550     Node* uncast_base = base->uncast();
 551     int opcode = uncast_base->Opcode();
 552     assert(opcode == Op_ConP || opcode == Op_ThreadLocal ||
 553            opcode == Op_CastX2P || uncast_base->is_DecodeN() ||
 554            (uncast_base->is_Mem() && uncast_base->bottom_type() == TypeRawPtr::NOTNULL) ||
 555            (uncast_base->is_Proj() && uncast_base->in(0)->is_Allocate()), "sanity");
 556   }
 557   return base;
 558 }
 559 
 560 Node* ConnectionGraph::find_second_addp(Node* addp, Node* n) {
 561   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
 562 
 563   Node* addp2 = addp->raw_out(0);
 564   if (addp->outcnt() == 1 && addp2->is_AddP() &&
 565       addp2->in(AddPNode::Base) == n &&
 566       addp2->in(AddPNode::Address) == addp) {
 567 
 568     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
 569     //
 570     // Find array's offset to push it on worklist first and
 571     // as result process an array's element offset first (pushed second)
 572     // to avoid CastPP for the array's offset.
 573     // Otherwise the inserted CastPP (LocalVar) will point to what
 574     // the AddP (Field) points to. Which would be wrong since
 575     // the algorithm expects the CastPP has the same point as
 576     // as AddP's base CheckCastPP (LocalVar).
 577     //
 578     //    ArrayAllocation
 579     //     |
 580     //    CheckCastPP


 631   //
 632   // Or the type 't' could be not related to 'base_t' at all.
 633   // It could happened when CHA type is different from MDO type on a dead path
 634   // (for example, from instanceof check) which is not collapsed during parsing.
 635   //
 636   // Do nothing for such AddP node and don't process its users since
 637   // this code branch will go away.
 638   //
 639   if (!t->is_known_instance() &&
 640       !base_t->klass()->is_subtype_of(t->klass())) {
 641      return false; // bail out
 642   }
 643 
 644   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
 645   // Do NOT remove the next line: ensure a new alias index is allocated
 646   // for the instance type. Note: C++ will not remove it since the call
 647   // has side effect.
 648   int alias_idx = _compile->get_alias_index(tinst);
 649   igvn->set_type(addp, tinst);
 650   // record the allocation in the node map
 651   set_map(addp, get_map(base->_idx));

 652 
 653   // Set addp's Base and Address to 'base'.
 654   Node *abase = addp->in(AddPNode::Base);
 655   Node *adr   = addp->in(AddPNode::Address);
 656   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
 657       adr->in(0)->_idx == (uint)inst_id) {
 658     // Skip AddP cases #3 and #5.
 659   } else {
 660     assert(!abase->is_top(), "sanity"); // AddP case #3
 661     if (abase != base) {
 662       igvn->hash_delete(addp);
 663       addp->set_req(AddPNode::Base, base);
 664       if (abase == adr) {
 665         addp->set_req(AddPNode::Address, base);
 666       } else {
 667         // AddP case #4 (adr is array's element offset AddP node)
 668 #ifdef ASSERT
 669         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
 670         assert(adr->is_AddP() && atype != NULL &&
 671                atype->instance_id() == inst_id, "array's element offset should be processed first");


 709         return phi->as_Phi();
 710       }
 711     }
 712   }
 713   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
 714     if (C->do_escape_analysis() == true && !C->failing()) {
 715       // Retry compilation without escape analysis.
 716       // If this is the first failure, the sentinel string will "stick"
 717       // to the Compile object, and the C2Compiler will see it and retry.
 718       C->record_failure(C2Compiler::retry_no_escape_analysis());
 719     }
 720     return NULL;
 721   }
 722   orig_phi_worklist.append_if_missing(orig_phi);
 723   const TypePtr *atype = C->get_adr_type(alias_idx);
 724   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
 725   C->copy_node_notes_to(result, orig_phi);
 726   igvn->set_type(result, result->bottom_type());
 727   record_for_optimizer(result);
 728 
 729   set_map(orig_phi, result);



 730 
 731   new_created = true;
 732   return result;
 733 }
 734 
 735 //
 736 // Return a new version of Memory Phi "orig_phi" with the inputs having the
 737 // specified alias index.
 738 //
 739 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
 740 
 741   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
 742   Compile *C = _compile;
 743   bool new_phi_created;
 744   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
 745   if (!new_phi_created) {
 746     return result;
 747   }
 748 
 749   GrowableArray<PhiNode *>  phi_list;


 786       Node* in = result->in(i);
 787       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
 788     }
 789     // we have finished processing a Phi, see if there are any more to do
 790     finished = (phi_list.length() == 0 );
 791     if (!finished) {
 792       phi = phi_list.pop();
 793       idx = cur_input.pop();
 794       PhiNode *prev_result = get_map_phi(phi->_idx);
 795       prev_result->set_req(idx++, result);
 796       result = prev_result;
 797     }
 798   }
 799   return result;
 800 }
 801 
 802 
 803 //
 804 // The next methods are derived from methods in MemNode.
 805 //
 806 Node* ConnectionGraph::step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
 807   Node *mem = mmem;
 808   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
 809   // means an array I have not precisely typed yet.  Do not do any
 810   // alias stuff with it any time soon.
 811   if (toop->base() != Type::AnyPtr &&
 812       !(toop->klass() != NULL &&
 813         toop->klass()->is_java_lang_Object() &&
 814         toop->offset() == Type::OffsetBot)) {
 815     mem = mmem->memory_at(alias_idx);
 816     // Update input if it is progress over what we have now
 817   }
 818   return mem;
 819 }
 820 
 821 //
 822 // Move memory users to their memory slices.
 823 //
 824 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
 825   Compile* C = _compile;
 826 
 827   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
 828   assert(tp != NULL, "ptr type");
 829   int alias_idx = C->get_alias_index(tp);
 830   int general_idx = C->get_general_index(alias_idx);
 831 
 832   // Move users first
 833   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
 834     Node* use = n->fast_out(i);


1084 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
1085 //
1086 //    40  StoreP  25  7   20   ... alias_index=4
1087 //    50  StoreP  35  7   30   ... alias_index=6
1088 //    60  StoreP  45  40  20   ... alias_index=4
1089 //    70  LoadP    _  50  30   ... alias_index=6
1090 //    80  Phi     75  40  60   Memory alias_index=4
1091 //   120  Phi     75  50  50   Memory alias_index=6
1092 //    90  LoadP    _ 120  30   ... alias_index=6
1093 //   100  LoadP    _  80  20   ... alias_index=4
1094 //
1095 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
1096   GrowableArray<Node *>  memnode_worklist;
1097   GrowableArray<PhiNode *>  orig_phis;
1098 
1099   PhaseIterGVN  *igvn = _igvn;
1100   uint new_index_start = (uint) _compile->num_alias_types();
1101   Arena* arena = Thread::current()->resource_area();
1102   VectorSet visited(arena);
1103 
1104   ideal_nodes.clear(); // Reset for use with set_map/get_map.
1105 
1106   uint unique_old = _compile->unique();
1107 
1108   //  Phase 1:  Process possible allocations from alloc_worklist.
1109   //  Create instance types for the CheckCastPP for allocations where possible.
1110   //
1111   // (Note: don't forget to change the order of the second AddP node on
1112   //  the alloc_worklist if the order of the worklist processing is changed,
1113   //  see the comment in find_second_addp().)
1114   //
1115   while (alloc_worklist.length() != 0) {
1116     Node *n = alloc_worklist.pop();
1117     uint ni = n->_idx;

1118     if (n->is_Call()) {
1119       CallNode *alloc = n->as_Call();
1120       // copy escape information to call node
1121       PointsToNode* ptn = ptnode_adr(alloc->_idx);
1122       PointsToNode::EscapeState es = ptn->escape_state();
1123       // We have an allocation or call which returns a Java object,
1124       // see if it is unescaped.
1125       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
1126         continue;
1127 
1128       // Find CheckCastPP for the allocate or for the return value of a call
1129       n = alloc->result_cast();
1130       if (n == NULL) {            // No uses except Initialize node
1131         if (alloc->is_Allocate()) {
1132           // Set the scalar_replaceable flag for allocation
1133           // so it could be eliminated if it has no uses.
1134           alloc->as_Allocate()->_is_scalar_replaceable = true;
1135         }
1136         continue;
1137       }
1138       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
1139         assert(!alloc->is_Allocate(), "allocation should have unique type");
1140         continue;
1141       }
1142 


1154           Node *use = n->fast_out(i);
1155           if (use->is_CheckCastPP()) {
1156             cast2 = use;
1157             break;
1158           }
1159         }
1160         if (cast2 != NULL) {
1161           n = cast2;
1162         } else {
1163           // Non-scalar replaceable if the allocation type is unknown statically
1164           // (reflection allocation), the object can't be restored during
1165           // deoptimization without precise type.
1166           continue;
1167         }
1168       }
1169       if (alloc->is_Allocate()) {
1170         // Set the scalar_replaceable flag for allocation
1171         // so it could be eliminated.
1172         alloc->as_Allocate()->_is_scalar_replaceable = true;
1173       }
1174       set_escape_state(ptnode_adr(n->_idx), es); // CheckCastPP escape state
1175       // in order for an object to be scalar-replaceable, it must be:
1176       //   - a direct allocation (not a call returning an object)
1177       //   - non-escaping
1178       //   - eligible to be a unique type
1179       //   - not determined to be ineligible by escape analysis
1180       set_map(alloc, n);
1181       set_map(n, alloc);


1182       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
1183       if (t == NULL)
1184         continue;  // not a TypeOopPtr
1185       const TypeOopPtr* tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
1186       igvn->hash_delete(n);
1187       igvn->set_type(n,  tinst);
1188       n->raise_bottom_type(tinst);
1189       igvn->hash_insert(n);
1190       record_for_optimizer(n);
1191       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
1192 
1193         // First, put on the worklist all Field edges from Connection Graph
1194         // which is more accurate then putting immediate users from Ideal Graph.
1195         for (uint e = 0; e < ptn->edge_count(); e++) {
1196           PointsToNode* tgt = ptn->edge(e);
1197           Node* use = tgt->ideal_node();
1198           assert(tgt->is_Field() && use->is_AddP(),
1199                  "only AddP nodes are Field edges in CG");
1200           if (use->outcnt() > 0) { // Don't process dead nodes
1201             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
1202             if (addp2 != NULL) {
1203               assert(alloc->is_AllocateArray(),"array allocation was expected");
1204               alloc_worklist.append_if_missing(addp2);
1205             }
1206             alloc_worklist.append_if_missing(use);
1207           }
1208         }
1209 
1210         // An allocation may have an Initialize which has raw stores. Scan
1211         // the users of the raw allocation result and push AddP users
1212         // on alloc_worklist.
1213         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
1214         assert (raw_result != NULL, "must have an allocation result");
1215         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
1216           Node *use = raw_result->fast_out(i);
1217           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
1218             Node* addp2 = find_second_addp(use, raw_result);
1219             if (addp2 != NULL) {
1220               assert(alloc->is_AllocateArray(),"array allocation was expected");
1221               alloc_worklist.append_if_missing(addp2);
1222             }
1223             alloc_worklist.append_if_missing(use);
1224           } else if (use->is_MemBar()) {
1225             memnode_worklist.append_if_missing(use);
1226           }
1227         }
1228       }
1229     } else if (n->is_AddP()) {
1230       JavaObjectNode* jobj = unique_java_object(get_addp_base(n));
1231       if (jobj == NULL || jobj == phantom_obj) {
1232 #ifdef ASSERT
1233         ptnode_adr(get_addp_base(n)->_idx)->dump();
1234         ptnode_adr(n->_idx)->dump();
1235         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
1236 #endif
1237         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
1238         return;
1239       }
1240       Node *base = get_map(jobj->idx());  // CheckCastPP node
1241       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path

1242     } else if (n->is_Phi() ||
1243                n->is_CheckCastPP() ||
1244                n->is_EncodeP() ||
1245                n->is_DecodeN() ||
1246                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
1247       if (visited.test_set(n->_idx)) {
1248         assert(n->is_Phi(), "loops only through Phi's");
1249         continue;  // already processed
1250       }
1251       JavaObjectNode* jobj = unique_java_object(n);
1252       if (jobj == NULL || jobj == phantom_obj) {
1253 #ifdef ASSERT
1254         ptnode_adr(n->_idx)->dump();
1255         assert(jobj != NULL && jobj != phantom_obj, "escaped allocation");
1256 #endif
1257         _compile->record_failure(C2Compiler::retry_no_escape_analysis());
1258         return;
1259       } else {
1260         Node *val = get_map(jobj->idx());   // CheckCastPP node
1261         TypeNode *tn = n->as_Type();
1262         const TypeOopPtr* tinst = igvn->type(val)->isa_oopptr();
1263         assert(tinst != NULL && tinst->is_known_instance() &&
1264                tinst->instance_id() == jobj->idx() , "instance type expected.");
1265 
1266         const Type *tn_type = igvn->type(tn);
1267         const TypeOopPtr *tn_t;
1268         if (tn_type->isa_narrowoop()) {
1269           tn_t = tn_type->make_ptr()->isa_oopptr();
1270         } else {
1271           tn_t = tn_type->isa_oopptr();
1272         }
1273 
1274         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
1275           if (tn_type->isa_narrowoop()) {
1276             tn_type = tinst->make_narrowoop();
1277           } else {
1278             tn_type = tinst;
1279           }
1280           igvn->hash_delete(tn);
1281           igvn->set_type(tn, tn_type);
1282           tn->set_type(tn_type);
1283           igvn->hash_insert(tn);
1284           record_for_optimizer(n);


1327           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
1328         }
1329       } else {
1330         uint op = use->Opcode();
1331         if (!(op == Op_CmpP || op == Op_Conv2B ||
1332               op == Op_CastP2X || op == Op_StoreCM ||
1333               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
1334               op == Op_StrEquals || op == Op_StrIndexOf)) {
1335           n->dump();
1336           use->dump();
1337           assert(false, "EA: missing allocation reference path");
1338         }
1339 #endif
1340       }
1341     }
1342 
1343   }
1344   // New alias types were created in split_AddP().
1345   uint new_index_end = (uint) _compile->num_alias_types();
1346 
1347   assert(unique_old == _compile->unique(), "there should be no new ideal nodes after Phase 1");
1348 
1349   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
1350   //            compute new values for Memory inputs  (the Memory inputs are not
1351   //            actually updated until phase 4.)
1352   if (memnode_worklist.length() == 0)
1353     return;  // nothing to do
1354 
1355   while (memnode_worklist.length() != 0) {
1356     Node *n = memnode_worklist.pop();
1357     if (visited.test_set(n->_idx))
1358       continue;
1359     if (n->is_Phi() || n->is_ClearArray()) {
1360       // we don't need to do anything, but the users must be pushed
1361     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
1362       // we don't need to do anything, but the users must be pushed
1363       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
1364       if (n == NULL)
1365         continue;
1366     } else {
1367       assert(n->is_Mem(), "memory node required.");
1368       Node *addr = n->in(MemNode::Address);
1369       const Type *addr_t = igvn->type(addr);
1370       if (addr_t == Type::TOP)
1371         continue;
1372       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
1373       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
1374       assert ((uint)alias_idx < new_index_end, "wrong alias index");
1375       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
1376       if (_compile->failing()) {
1377         return;
1378       }
1379       if (mem != n->in(MemNode::Memory)) {
1380         // We delay the memory edge update since we need old one in
1381         // MergeMem code below when instances memory slices are separated.
1382         set_map(n, mem);



1383       }
1384       if (n->is_Load()) {
1385         continue;  // don't push users
1386       } else if (n->is_LoadStore()) {
1387         // get the memory projection
1388         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1389           Node *use = n->fast_out(i);
1390           if (use->Opcode() == Op_SCMemProj) {
1391             n = use;
1392             break;
1393           }
1394         }
1395         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
1396       }
1397     }
1398     // push user on appropriate worklist
1399     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1400       Node *use = n->fast_out(i);
1401       if (use->is_Phi() || use->is_ClearArray()) {
1402         memnode_worklist.append_if_missing(use);


1514       if (_compile->failing()) {
1515         return;
1516       }
1517       if (mem != new_mem) {
1518         phi->set_req(i, new_mem);
1519       }
1520     }
1521     igvn->hash_insert(phi);
1522     record_for_optimizer(phi);
1523   }
1524 
1525   // Update the memory inputs of MemNodes with the value we computed
1526   // in Phase 2 and move stores memory users to corresponding memory slices.
1527 
1528   // Disable memory split verification code until the fix for 6984348.
1529   // Currently it produces false negative results since it does not cover all cases.
1530 #if 0 // ifdef ASSERT
1531   visited.Reset();
1532   Node_Stack old_mems(arena, _compile->unique() >> 2);
1533 #endif
1534   for (uint i = 0; i < ideal_nodes.size(); i++) {
1535     Node*    n = ideal_nodes.at(i);
1536     Node* nmem = get_map(n->_idx);
1537     assert(nmem != NULL, "sanity");

1538     if (n->is_Mem()) {
1539 #if 0 // ifdef ASSERT
1540       Node* old_mem = n->in(MemNode::Memory);
1541       if (!visited.test_set(old_mem->_idx)) {
1542         old_mems.push(old_mem, old_mem->outcnt());
1543       }
1544 #endif
1545       assert(n->in(MemNode::Memory) != nmem, "sanity");
1546       if (!n->is_Load()) {
1547         // Move memory users of a store first.
1548         move_inst_mem(n, orig_phis, igvn);
1549       }
1550       // Now update memory input
1551       igvn->hash_delete(n);
1552       n->set_req(MemNode::Memory, nmem);
1553       igvn->hash_insert(n);
1554       record_for_optimizer(n);
1555     } else {
1556       assert(n->is_Allocate() || n->is_CheckCastPP() ||
1557              n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
1558     }
1559   }

1560 #if 0 // ifdef ASSERT
1561   // Verify that memory was split correctly
1562   while (old_mems.is_nonempty()) {
1563     Node* old_mem = old_mems.node();
1564     uint  old_cnt = old_mems.index();
1565     old_mems.pop();
1566     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
1567   }
1568 #endif
1569 }
1570 
1571 bool ConnectionGraph::has_candidates(Compile *C) {
1572   // EA brings benefits only when the code has allocations and/or locks which
1573   // are represented by ideal Macro nodes.
1574   int cnt = C->macro_count();
1575   for( int i=0; i < cnt; i++ ) {
1576     Node *n = C->macro_node(i);
1577     if ( n->is_Allocate() )
1578       return true;
1579     if( n->is_Lock() ) {
1580       Node* obj = n->as_Lock()->obj_node()->uncast();
1581       if( !(obj->is_Parm() || obj->is_Con()) )
1582         return true;
1583     }
1584   }
1585   return false;
1586 }
1587 
1588 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
1589   Compile::TracePhase t2("escapeAnalysis", &Phase::_t_escapeAnalysis, true);
1590 
1591   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
1592   // to create space for them in ConnectionGraph::_nodes[].
1593   Node* oop_null = igvn->zerocon(T_OBJECT);
1594   Node* noop_null = igvn->zerocon(T_NARROWOOP);
1595 
1596   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
1597   // Perform escape analysis
1598   if (congraph->compute_escape()) {
1599     // There are non escaping objects.
1600     C->set_congraph(congraph);
1601   }
1602 
1603   // Cleanup.
1604   if (oop_null->outcnt() == 0)
1605     igvn->hash_delete(oop_null);
1606   if (noop_null->outcnt() == 0)
1607     igvn->hash_delete(noop_null);
1608 }
1609 
1610 bool ConnectionGraph::compute_escape() {
1611   Compile* C = _compile;
1612   PhaseGVN* igvn = _igvn;
1613 
1614   // 1. Populate Connection Graph (CG) with PointsTo nodes.
1615 
1616   ideal_nodes.map(C->unique(), NULL);  // preallocate space

1617 
1618   // Initialize worklist
1619   if (C->root() != NULL) {
1620     ideal_nodes.push(C->root());
1621   }
1622 
1623   DEBUG_ONLY( GrowableArray<Node*> addp_worklist; )
1624 
1625   Unique_Node_List delayed_worklist;
1626   GrowableArray<Node*> alloc_worklist;

1627   GrowableArray<Node*> ptr_cmp_worklist;
1628   GrowableArray<Node*> storestore_worklist;

1629 
1630   GrowableArray<PointsToNode*>   ptnodes_worklist;
1631   GrowableArray<JavaObjectNode*> java_objects_worklist;
1632   GrowableArray<JavaObjectNode*> non_escaped_worklist;
1633   GrowableArray<FieldNode*>      oop_fields_worklist;
1634 
1635   { Compile::TracePhase t3("connectionGraph", &Phase::_t_connectionGraph, true);
1636 
1637   // Push all useful nodes onto CG list and set their type.
1638   for( uint next = 0; next < ideal_nodes.size(); ++next ) {
1639     Node* n = ideal_nodes.at(next);
1640 
1641     // It is called only once per node since ideal_nodes is Unique_Node list.
1642     build_connection_graph(n, &delayed_worklist, igvn);
1643 
1644     PointsToNode* ptn = ptnode_adr(n->_idx);
1645     if (ptn != NULL) {
1646       ptnodes_worklist.append(ptn);
1647       if (ptn->is_JavaObject()) {
1648         java_objects_worklist.append(ptn->as_JavaObject());
1649         if ((n->is_Allocate() || n->is_CallStaticJava()) &&
1650             (ptn->escape_state() < PointsToNode::GlobalEscape)) {
1651           // Only allocations and java static calls results are interesting.
1652           non_escaped_worklist.append(ptn->as_JavaObject());
1653         }
1654       } else if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
1655         oop_fields_worklist.append(ptn->as_Field());
1656       }
1657     }
1658     if (n->is_MergeMem()) {
1659       // Collect all MergeMem nodes to add memory slices for
1660       // scalar replaceable objects in split_unique_types().
1661       _mergemem_worklist.append(n->as_MergeMem());
1662     } else if (OptimizePtrCompare && n->is_Cmp() &&
1663                (n->Opcode() == Op_CmpP || n->Opcode() == Op_CmpN)) {
1664       // Compare pointers nodes
1665       ptr_cmp_worklist.append(n);
1666     } else if (n->is_MemBarStoreStore()) {
1667       // Collect all MemBarStoreStore nodes so that depending on the
1668       // escape status of the associated Allocate node some of them
1669       // may be eliminated.
1670       storestore_worklist.append(n);
1671 #ifdef ASSERT
1672     } else if(n->is_AddP()) {
1673       // Collect address nodes. Use them during stage 3 below
1674       // to build initial connection graph field edges.
1675       addp_worklist.append(n);
1676 #endif
1677     }
1678     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1679       Node* m = n->fast_out(i);   // Get user
1680       ideal_nodes.push(m);
1681     }
1682   }
1683 
1684   if (non_escaped_worklist.length() == 0) {
1685     _collecting = false;
1686     return false; // Nothing to do.
1687   }
1688 
1689   // Add final simple edges.
1690   while(delayed_worklist.size() > 0) {
1691     Node* n = delayed_worklist.pop();
1692     build_connection_graph(n, NULL, igvn);

1693   }
1694 
1695   uint ptnodes_length = ptnodes_worklist.length();












1696 
1697 #ifdef ASSERT
1698   if (VerifyConnectionGraph) {
1699     // Verify that no new simple edges could be created and all
1700     // local vars has edges.
1701     _verify = true;
1702     for (uint next = 0; next < ptnodes_length; ++next) {
1703       PointsToNode* ptn = ptnodes_worklist.at(next);
1704       build_connection_graph(ptn->ideal_node(), NULL, igvn);
1705       if (ptn->is_LocalVar() && ptn->edge_count() == 0) {
1706         ptn->dump();
1707         assert(ptn->as_LocalVar()->edge_count() > 0, "sanity");





1708       }
1709     }
1710     _verify = false;
1711   }
1712 #endif
1713 
1714   // 2. Finish Graph construction.
1715 




1716   // Normally only 1-3 passes needed to build
1717   // Connection Graph depending on graph complexity.
1718   // Observed 8 passes in jvm2008 compiler.compiler.
1719   // Set limit to 20 to catch situation when something
1720   // did go wrong and recompile the method without EA.
1721   // Also limit build time to 30 sec (60 in debug VM).
1722 
1723 #define CG_BUILD_ITER_LIMIT 20
1724 
1725 #ifdef ASSERT
1726 #define CG_BUILD_TIME_LIMIT 60.0
1727 #else
1728 #define CG_BUILD_TIME_LIMIT 30.0
1729 #endif
1730 

1731   int iterations = 0;
1732 
1733   // Propagate GlobalEscape and ArgEscape escape states
1734   // and check that we still have non escaped objects.
1735   // The method pushs on _worklist Field nodes which reference phantom_object.
1736   if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1737     _collecting = false;
1738     return false; // Nothing to do.
1739   }
1740 
1741   // Propagate references to all JavaObject nodes.
1742   uint java_objects_length = java_objects_worklist.length();
1743 
1744   elapsedTimer time;
1745   int new_edges = 1;
1746   do {
1747     while ((new_edges > 0) &&
1748           (iterations++   < CG_BUILD_ITER_LIMIT) &&
1749           (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1750       time.start();
1751       new_edges = 0;
1752       // Propagate references to phantom_object for nodes pushed on _worklist
1753       // by find_non_escaped_objects() and find_field_value().
1754       new_edges += add_java_object_edges(phantom_obj, false);
1755       for (uint next = 0; next < java_objects_length; ++next) {
1756         JavaObjectNode* ptn = java_objects_worklist.at(next);
1757         new_edges += add_java_object_edges(ptn, true);
1758       }
1759       if (new_edges > 0) {
1760         // Update escape states on each iteration if graph was updated.
1761         if (!find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist)) {
1762           _collecting = false;
1763           return false; // Nothing to do.
1764         }
1765       }
1766       time.stop();
1767     }
1768 
1769     if ((iterations     < CG_BUILD_ITER_LIMIT) &&
1770         (time.seconds() < CG_BUILD_TIME_LIMIT)) {
1771       time.start();
1772       // Find fields which have unknown value.
1773       uint fields_length = oop_fields_worklist.length();
1774       for (uint next = 0; next < fields_length; next++) {
1775         FieldNode* field = oop_fields_worklist.at(next);
1776         if (field->edge_count() == 0) {
1777           new_edges += find_field_value(field);
1778           // This code may added new edges to phantom_object.
1779           // Need an other cycle to propagate references to phantom_object.
1780         }
1781       }
1782       time.stop();
1783     }
1784   } while (new_edges > 0);
1785 
1786   if ((iterations     >= CG_BUILD_ITER_LIMIT) ||
1787       (time.seconds() >= CG_BUILD_TIME_LIMIT)) {
1788     assert(false, err_msg("infinite EA connection graph build (%f sec, %d iterations) with %d nodes and worklist size %d",
1789            time.seconds(), iterations, nodes_size(), ptnodes_length));
1790     // Possible infinite build_connection_graph loop,
1791     // bailout (no changes to ideal graph were made).
1792     _collecting = false;
1793     return false;
1794   }
1795 
1796 #ifdef ASSERT
1797   if (Verbose && PrintEscapeAnalysis) {
1798     tty->print_cr("EA: %d iterations to build connection graph with %d nodes and worklist size %d",
1799                   iterations, nodes_size(), ptnodes_length);
1800   }
1801 #endif
1802 
1803 #undef CG_BUILD_ITER_LIMIT
1804 #undef CG_BUILD_TIME_LIMIT
1805 


1806 
1807   // 3. Find fields initialized by NULL for non escaped Allocations.

1808 
1809   uint non_escaped_length = non_escaped_worklist.length();
1810   for (uint next = 0; next < non_escaped_length; next++) {
1811     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1812     PointsToNode::EscapeState es = ptn->escape_state();
1813     assert(es <= PointsToNode::ArgEscape, "sanity");
1814 








1815     if (es == PointsToNode::NoEscape) {
1816       if (find_init_values(ptn, null_obj, igvn) > 0) {
1817         // Adding references to NULL object does not change escape states
1818         // since it does not escape. Also no fields are added to NULL object.
1819         add_java_object_edges(null_obj, false);
1820       }
1821     }
1822     Node* n = ptn->ideal_node();
1823     if (n->is_Allocate()) {

1824       // The object allocated by this Allocate node will never be
1825       // seen by an other thread. Mark it so that when it is
1826       // expanded no MemBarStoreStore is added.
1827       InitializeNode* ini = n->as_Allocate()->initialization();
1828       if (ini != NULL)
1829         ini->set_does_not_escape();
1830     }




1831   }

1832 
1833 #ifdef ASSERT
1834   if (VerifyConnectionGraph) {
1835     uint addp_length = addp_worklist.length();
1836     for (uint next = 0; next < addp_length; ++next ) {
1837       Node* n = addp_worklist.at(next);
1838       FieldNode* field = ptnode_adr(n->_idx)->as_Field();
1839       if (field->is_oop()) {
1840         // Verify that field has all bases
1841         Node* base = get_addp_base(n);
1842         PointsToNode* ptn = ptnode_adr(base->_idx);
1843         if (ptn->is_JavaObject()) {
1844           assert(field->has_base(ptn->as_JavaObject()), "sanity");
1845         } else {
1846           assert(ptn->is_LocalVar(), "sanity");
1847           uint count = ptn->edge_count();
1848           for (uint i = 0; i < count; i++) {
1849             PointsToNode* e = ptn->edge(i);
1850             if (e->is_JavaObject()) {
1851               assert(field->has_base(e->as_JavaObject()), "sanity");
1852             }










1853           }
1854         }
1855         // Verify that all fields have initializing values.
1856         if (field->edge_count() == 0) {
1857           field->dump();
1858           assert(field->edge_count() > 0, "sanity");
1859         }








1860       }
1861     }





1862   }
1863 #endif
1864 
1865   // 4. Adjust scalar_replaceable state of nonescaping objects.







1866 
1867   for (uint next = 0; next < non_escaped_length; next++) {
1868     JavaObjectNode* ptn = non_escaped_worklist.at(next);
1869     if (ptn->escape_state() == PointsToNode::NoEscape &&
1870         ptn->scalar_replaceable()) {
1871       adjust_scalar_replaceable_state(ptn);
1872 
1873       if (ptn->scalar_replaceable()) {

1874         // Push scalar replaceable allocations on alloc_worklist
1875         // for processing in split_unique_types().
1876         alloc_worklist.append(ptn->ideal_node());

1877       }










1878     }




1879   }
1880 
1881 #ifdef ASSERT
1882   if (VerifyConnectionGraph) {
1883     // Verify that graph is complete - no new edges could be added.
1884     new_edges = 0;
1885     for (uint next = 0; next < java_objects_length; ++next) {
1886       JavaObjectNode* ptn = java_objects_worklist.at(next);
1887       new_edges += add_java_object_edges(ptn, true);
1888     }
1889     assert(new_edges == 0, "graph was not complete");
1890 
1891     // Verify that escape state is final.
1892     uint length = non_escaped_worklist.length();
1893     find_non_escaped_objects(ptnodes_worklist, non_escaped_worklist);
1894     assert((non_escaped_length == (uint)non_escaped_worklist.length()) &&
1895            (non_escaped_length == length) &&
1896            (_worklist.length() == 0), "escape state was not final");
1897   }
1898 #endif
1899 
1900   _collecting = false;
1901   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
1902 
1903   assert(null_obj->escape_state() == PointsToNode::NoEscape &&
1904          null_obj->edge_count() == 0 &&
1905          !null_obj->arraycopy_src() &&
1906          !null_obj->arraycopy_dst(), "sanity");


1907 
1908   } // TracePhase t3("connectionGraph")
1909 
1910   bool has_non_escaping_obj = (non_escaped_worklist.length() > 0);
1911 
1912   if (EliminateLocks && has_non_escaping_obj) {
1913     // Mark locks before changing ideal graph.
1914     int cnt = C->macro_count();
1915     for( int i=0; i < cnt; i++ ) {
1916       Node *n = C->macro_node(i);
1917       if (n->is_AbstractLock()) { // Lock and Unlock nodes
1918         AbstractLockNode* alock = n->as_AbstractLock();
1919         if (!alock->is_non_esc_obj()) {
1920           if (not_global_escape(alock->obj_node())) {


1921             assert(!alock->is_eliminated() || alock->is_coarsened(), "sanity");
1922             // The lock could be marked eliminated by lock coarsening
1923             // code during first IGVN before EA. Replace coarsened flag
1924             // to eliminate all associated locks/unlocks.
1925             alock->set_non_esc_obj();
1926           }
1927         }
1928       }
1929     }
1930   }
1931 
1932   if (OptimizePtrCompare && has_non_escaping_obj) {
1933     // Add ConI(#CC_GT) and ConI(#CC_EQ).
1934     _pcmp_neq = igvn->makecon(TypeInt::CC_GT);
1935     _pcmp_eq = igvn->makecon(TypeInt::CC_EQ);
1936     // Optimize objects compare.
1937     while (ptr_cmp_worklist.length() != 0) {
1938       Node *n = ptr_cmp_worklist.pop();
1939       Node *res = optimize_ptr_compare(n);
1940       if (res != NULL) {


1960   // escape status of associated AllocateNode and optimize out
1961   // MemBarStoreStore node if the allocated object never escapes.
1962   while (storestore_worklist.length() != 0) {
1963     Node *n = storestore_worklist.pop();
1964     MemBarStoreStoreNode *storestore = n ->as_MemBarStoreStore();
1965     Node *alloc = storestore->in(MemBarNode::Precedent)->in(0);
1966     assert (alloc->is_Allocate(), "storestore should point to AllocateNode");
1967     PointsToNode::EscapeState es = ptnode_adr(alloc->_idx)->escape_state();
1968     if (es == PointsToNode::NoEscape || es == PointsToNode::ArgEscape) {
1969       MemBarNode* mb = MemBarNode::make(C, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1970       mb->init_req(TypeFunc::Memory, storestore->in(TypeFunc::Memory));
1971       mb->init_req(TypeFunc::Control, storestore->in(TypeFunc::Control));
1972 
1973       _igvn->register_new_node_with_optimizer(mb);
1974       _igvn->replace_node(storestore, mb);
1975     }
1976   }
1977 
1978 #ifndef PRODUCT
1979   if (PrintEscapeAnalysis) {
1980     dump(ptnodes_worklist); // Dump ConnectionGraph
1981   }
1982 #endif
1983 
1984   bool has_scalar_replaceable_candidates = (alloc_worklist.length() > 0);
1985 #ifdef ASSERT
1986   if (VerifyConnectionGraph) {
1987     uint alloc_length = alloc_worklist.length();
1988     for (uint next = 0; next < alloc_length; ++next) {
1989       Node* n = alloc_worklist.at(next);
1990       PointsToNode* ptn = ptnode_adr(n->_idx);
1991       assert(ptn->escape_state() == PointsToNode::NoEscape && ptn->scalar_replaceable(), "sanity");



1992     }
1993   }
1994 #endif
1995 
1996   if (has_scalar_replaceable_candidates &&
1997       C->AliasLevel() >= 3 && EliminateAllocations) {
1998 
1999     // Now use the escape information to create unique types for
2000     // scalar replaceable objects.
2001     split_unique_types(alloc_worklist);
2002 
2003     if (C->failing())  return false;
2004 
2005     C->print_method("After Escape Analysis", 2);
2006 
2007 #ifdef ASSERT
2008   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
2009     tty->print("=== No allocations eliminated for ");
2010     C->method()->print_short_name();
2011     if(!EliminateAllocations) {
2012       tty->print(" since EliminateAllocations is off ===");
2013     } else if(!has_scalar_replaceable_candidates) {
2014       tty->print(" since there are no scalar replaceable candidates ===");
2015     } else if(C->AliasLevel() < 3) {
2016       tty->print(" since AliasLevel < 3 ===");
2017     }
2018     tty->cr();
2019 #endif
2020   }
2021   return has_non_escaping_obj;
2022 }
2023 
2024 // Find fields which have unknown value.
2025 int ConnectionGraph::find_field_value(FieldNode* field) {
2026   // Escaped fields should have init value already.
2027   assert(field->escape_state() == PointsToNode::NoEscape, "sanity");
2028 
2029   int new_edges = 0;
2030 
2031   uint bcnt = field->base_count();
2032   for (uint i = 0; i < bcnt; i++) {
2033     PointsToNode* base = field->base(i);
2034     if (base->is_JavaObject()) {
2035       // Skip Allocate's fields which will be processed later.
2036       if (base->ideal_node()->is_Allocate())
2037         return 0;
2038       assert(base == null_obj, "only NULL ptr base expected here");
2039     }
2040   }
2041   if (add_edge(field, phantom_obj)) {
2042     // New edge was added
2043     new_edges++;
2044     add_field_uses_to_worklist(field);
2045   }
2046   return new_edges;
2047 }
2048 
2049 // Find fields initializing values for allocations.
2050 int ConnectionGraph::find_init_values(JavaObjectNode* pta, PointsToNode* init_val, PhaseTransform* phase) {


2051   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
2052 
2053   int new_edges = 0;
2054 
2055   Node* alloc = pta->ideal_node();
2056 
2057   if (init_val == phantom_obj) {
2058     // Do nothing for Allocate nodes since its fields values are "known".
2059     if (alloc->is_Allocate())
2060       return 0;
2061 
2062     assert(alloc->as_CallStaticJava(), "sanity");
2063 #ifdef ASSERT
2064     if (alloc->as_CallStaticJava()->method() == NULL) {
2065       const char* name = alloc->as_CallStaticJava()->_name;
2066       assert(strncmp(name, "_multianewarray", 15) == 0, "sanity");
2067     }
2068 #endif
2069 
2070     // Non-escaped allocation returned from Java or runtime call have
2071     // unknown values in fields.
2072     uint cnt = pta->edge_count();
2073     for (uint i = 0; i < cnt; i++) {
2074       PointsToNode* ptn = pta->edge(i);
2075       if (ptn->is_Field() && ptn->as_Field()->is_oop()) {
2076         if (add_edge(ptn, phantom_obj)) {
2077           // New edge was added
2078           new_edges++;
2079           add_field_uses_to_worklist(ptn->as_Field());
2080         }
2081       }
2082     }
2083     return new_edges;
2084   }
2085 
2086   assert(init_val == null_obj, "sanity");
2087   // Do nothing for Call nodes since its fields values are unknown.
2088   if (!alloc->is_Allocate())
2089     return 0;
2090 
2091   InitializeNode* ini = alloc->as_Allocate()->initialization();
2092 
2093   Compile* C = _compile;
2094   bool visited_bottom_offset = false;
2095   GrowableArray<int> offsets_worklist;
2096 
2097   // Check if a oop field's initializing value is recorded and add
2098   // a corresponding NULL if field's value if it is not recorded.
2099   // Connection Graph does not record a default initialization by NULL
2100   // captured by Initialize node.
2101   //

2102   uint ae_cnt = pta->edge_count();

2103   for (uint ei = 0; ei < ae_cnt; ei++) {
2104 
2105     PointsToNode* ptn = pta->edge(ei); // Field (AddP)
2106     if (!ptn->is_Field() || !ptn->as_Field()->is_oop())
2107       continue; // Not oop field
2108 
2109     int offset = ptn->as_Field()->offset();
2110     if (offset == Type::OffsetBot) {
2111       if (!visited_bottom_offset) {






2112         // OffsetBot is used to reference array's element,
2113         // always add reference to NULL to all Field nodes since we don't
2114         // known which element is referenced.
2115         if (add_edge(ptn, null_obj)) {
2116           // New edge was added
2117           new_edges++;
2118           add_field_uses_to_worklist(ptn->as_Field());
2119           visited_bottom_offset = true;
2120         }
2121       }










2122     } else {
2123       // Check only oop fields.
2124       const Type* adr_type = ptn->ideal_node()->as_AddP()->bottom_type();
2125       if (adr_type->isa_rawptr()) {






2126 #ifdef ASSERT

2127         // Raw pointers are used for initializing stores so skip it
2128         // since it should be recorded already
2129         Node* base = get_addp_base(ptn->ideal_node());
2130         assert(adr_type->isa_rawptr() && base->is_Proj() &&
2131                (base->in(0) == alloc),"unexpected pointer type");
2132 #endif
2133         continue;
2134       }
2135       if (!offsets_worklist.contains(offset)) {
2136         offsets_worklist.append(offset);

2137         Node* value = NULL;
2138         if (ini != NULL) {
2139           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
2140           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
2141           if (store != NULL && store->is_Store()) {
2142             value = store->in(MemNode::ValueIn);
2143           } else {
2144             // There could be initializing stores which follow allocation.
2145             // For example, a volatile field store is not collected
2146             // by Initialize node.
2147             //
2148             // Need to check for dependent loads to separate such stores from
2149             // stores which follow loads. For now, add initial value NULL so
2150             // that compare pointers optimization works correctly.
2151           }
2152         }
2153         if (value == NULL) {
2154           // A field's initializing value was not recorded. Add NULL.
2155           if (add_edge(ptn, null_obj)) {
2156             // New edge was added
2157             new_edges++;
2158             add_field_uses_to_worklist(ptn->as_Field());
2159           }
2160         }
2161       }
2162     }
2163   }
2164   return new_edges;
2165 }
2166 
2167 // Adjust scalar_replaceable state after Connection Graph is built.
2168 void ConnectionGraph::adjust_scalar_replaceable_state(JavaObjectNode* jobj) {
2169   // Search for non escaped objects which are not scalar replaceable


2170   // and mark them to propagate the state to referenced objects.
2171 
2172   // 1. An object is not scalar replaceable if the field into which it is
2173   // stored has unknown offset (stored into unknown element of an array).
2174   //
2175   uint count = jobj->use_count();
2176   for (uint i = 0; i < count; i++) {
2177     PointsToNode* use = jobj->use(i);
2178     assert(!use->is_Arraycopy(), "sanity");
2179     if (use->is_Field()) {
2180       FieldNode* field = use->as_Field();
2181       assert(field->is_oop() && field->scalar_replaceable() &&
2182              field->fields_escape_state() == PointsToNode::NoEscape, "sanity");
2183       if (field->offset() == Type::OffsetBot) {
2184         jobj->set_scalar_replaceable(false);
2185         return;
2186       }
2187     }
2188     assert(use->is_Field() || use->is_LocalVar(), "sanity");
2189 
2190     // 2. An object is not scalar replaceable if it is merged with other objects.
2191     uint e_count = use->edge_count();
2192     for (uint j = 0; j < e_count; j++) {
2193       PointsToNode* ptn = use->edge(j);
2194       if (ptn->is_JavaObject() && ptn != jobj) {
2195         // Mark all objects.
2196         jobj->set_scalar_replaceable(false);
2197          ptn->set_scalar_replaceable(false);
2198       }
2199     }
2200     if (!jobj->scalar_replaceable()) {
2201       return;
2202     }
2203   }
2204 
2205   count = jobj->edge_count();
2206   for (uint j = 0; j < count; j++) {
2207     // Non escaped object should points only to fields.
2208     FieldNode* field = jobj->edge(j)->as_Field();
2209     int offset = field->as_Field()->offset();
2210 
2211     // 3. An object is not scalar replaceable if it has a field with unknown
2212     // offset (array's element is accessed in loop).
2213     if (offset == Type::OffsetBot) {
2214       jobj->set_scalar_replaceable(false);
2215       return;


2216     }

2217 
2218     // 4. Currently an object is not scalar replaceable if a LoadStore node
2219     // access its field since the field value is unknown after it.
2220     //
2221     Node* n = field->ideal_node();
2222     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2223       if (n->fast_out(i)->is_LoadStore()) {
2224         jobj->set_scalar_replaceable(false);
2225         return;

2226       }
2227     }
2228 
2229     // 5. Or the address may point to more then one object. This may produce


2230     // the false positive result (set not scalar replaceable)
2231     // since the flow-insensitive escape analysis can't separate
2232     // the case when stores overwrite the field's value from the case
2233     // when stores happened on different control branches.
2234     //
2235     // Note: it will disable scalar replacement in some cases:
2236     //
2237     //    Point p[] = new Point[1];
2238     //    p[0] = new Point(); // Will be not scalar replaced
2239     //
2240     // but it will save us from incorrect optimizations in next cases:
2241     //
2242     //    Point p[] = new Point[1];
2243     //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
2244     //
2245     uint bcnt = field->base_count();
2246     if (bcnt > 1) {
2247       for (uint i = 0; i < bcnt; i++) {
2248         PointsToNode* base = field->base(i);
2249         // Don't take into account LocalVar nodes which
2250         // may point to only one object which should be also
2251         // this field's base by now.
2252         if (base->is_JavaObject() && base != jobj) {
2253           // Mark all bases.
2254           jobj->set_scalar_replaceable(false);
2255           base->set_scalar_replaceable(false);
2256         }
2257       }
2258     }
2259   }
2260 }
2261 





2262 
2263 // Propagate GlobalEscape and ArgEscape escape states to all nodes
2264 // and check that we still have non escaped java objects.
2265 bool ConnectionGraph::find_non_escaped_objects(GrowableArray<PointsToNode*>& ptnodes_worklist,
2266                                                GrowableArray<JavaObjectNode*>& non_escaped_worklist) {
2267   GrowableArray<PointsToNode*> escape_worklist;
2268 
2269   // First, put all nodes with GlobalEscape and ArgEscape states on worklist.
2270   uint ptnodes_length = ptnodes_worklist.length();
2271   for (uint next = 0; next < ptnodes_length; ++next) {
2272     PointsToNode* ptn = ptnodes_worklist.at(next);
2273     if (ptn->escape_state() >= PointsToNode::ArgEscape ||
2274         ptn->fields_escape_state() >= PointsToNode::ArgEscape) {
2275       escape_worklist.push(ptn);
2276     }










2277   }
2278   // Set escape states to referenced nodes (edges list).
2279   while (escape_worklist.length() > 0) {
2280     PointsToNode* ptn = escape_worklist.pop();
2281     PointsToNode::EscapeState es  = ptn->escape_state();
2282     PointsToNode::EscapeState field_es = ptn->fields_escape_state();
2283     if (ptn->is_Field() && ptn->as_Field()->is_oop() &&
2284         es >= PointsToNode::ArgEscape) {
2285       // GlobalEscape or ArgEscape state of field means it has unknown value.
2286       if (add_edge(ptn, phantom_obj)) {
2287         // New edge was added
2288         add_field_uses_to_worklist(ptn->as_Field());
2289       }









2290     }
2291     uint cnt = ptn->edge_count();
2292     for (uint i = 0; i < cnt; i++) {
2293       PointsToNode* e = ptn->edge(i);
2294       if (e->is_Arraycopy()) {
2295         assert(ptn->arraycopy_dst(), "sanity");
2296         // Propagate only fields escape state through arraycopy edge.
2297         if (e->fields_escape_state() < field_es) {
2298           set_fields_escape_state(e, field_es);
2299           escape_worklist.push(e);
2300         }
2301       } else if (es >= field_es) {
2302         // fields_escape_state is also set to 'es' if it is less than 'es'.
2303         if (e->escape_state() < es) {
2304           set_escape_state(e, es);
2305           escape_worklist.push(e);
2306         }
2307       } else {
2308         // Propagate field escape state.
2309         bool es_changed = false;
2310         if (e->fields_escape_state() < field_es) {
2311           set_fields_escape_state(e, field_es);
2312           es_changed = true;
2313         }
2314         if ((e->escape_state() < field_es) &&
2315             e->is_Field() && ptn->is_JavaObject() &&
2316             e->as_Field()->is_oop()) {
2317           // Change escape state of referenced fileds.
2318           set_escape_state(e, field_es);
2319           es_changed = true;;
2320         } else if (e->escape_state() < es) {
2321           set_escape_state(e, es);
2322           es_changed = true;;
2323         }
2324         if (es_changed) {
2325           escape_worklist.push(e);
2326         }
2327       }
2328     }
2329   }
2330 
2331   // Remove escaped objects from non_escaped list.
2332   for (int next = non_escaped_worklist.length()-1; next >= 0 ; --next) {
2333     JavaObjectNode* ptn = non_escaped_worklist.at(next);
2334     if (ptn->escape_state() >= PointsToNode::GlobalEscape) {
2335       non_escaped_worklist.delete_at(next);
2336     }
2337     if (ptn->escape_state() == PointsToNode::NoEscape) {
2338       // Find fields in non-escaped allocations which have unknown value.
2339       find_init_values(ptn, phantom_obj, NULL);
2340     }
2341   }
2342 
2343   return (non_escaped_worklist.length() > 0);
2344 }
2345 
2346 // Optimize objects compare.
2347 Node* ConnectionGraph::optimize_ptr_compare(Node* n) {
2348   assert(OptimizePtrCompare, "sanity");




2349 
2350   PointsToNode* ptn1 = ptnode_adr(n->in(1)->_idx);
2351   PointsToNode* ptn2 = ptnode_adr(n->in(2)->_idx);
2352   assert(ptn1->is_JavaObject() || ptn1->is_LocalVar(), "sanity");
2353   assert(ptn2->is_JavaObject() || ptn2->is_LocalVar(), "sanity");
2354 
2355   JavaObjectNode* jobj1 = unique_java_object(n->in(1));
2356   JavaObjectNode* jobj2 = unique_java_object(n->in(2));
2357 
2358   // Check simple cases first.
2359   if (jobj1 != NULL) {
2360     if (jobj1->escape_state() == PointsToNode::NoEscape) {
2361       if (jobj1 == jobj2) {


2362         // Comparing the same not escaping object.
2363         return _pcmp_eq;
2364       }
2365       Node* obj = jobj1->ideal_node();
2366       // Comparing not escaping allocation.
2367       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2368           !ptn2->points_to(jobj1)) {
2369         return _pcmp_neq; // This includes nullness check.
2370       }
2371     }
2372   }
2373   if (jobj2 != NULL) {
2374     if (jobj2->escape_state() == PointsToNode::NoEscape) {
2375       Node* obj = jobj2->ideal_node();

2376       // Comparing not escaping allocation.
2377       if ((obj->is_Allocate() || obj->is_CallStaticJava()) &&
2378           !ptn1->points_to(jobj2)) {
2379         return _pcmp_neq; // This includes nullness check.
2380       }
2381     }
2382   }
2383 
2384   if (jobj1 != NULL && jobj1 != phantom_obj &&
2385       jobj2 != NULL && jobj2 != phantom_obj &&
2386       jobj1->ideal_node()->is_Con() &&
2387       jobj2->ideal_node()->is_Con()) {
2388     // Klass or String constants compare. Need to be careful with
2389     // compressed pointers - compare types of ConN and ConP instead of nodes.
2390     const Type* t1 = jobj1->ideal_node()->bottom_type()->make_ptr();
2391     const Type* t2 = jobj2->ideal_node()->bottom_type()->make_ptr();
2392     assert(t1 != NULL && t2 != NULL, "sanity");
2393     if (t1->make_ptr() == t2->make_ptr()) {
2394       return _pcmp_eq;
2395     } else {
2396       return _pcmp_neq;
2397     }
2398   }
2399 
2400   if (ptn1->meet(ptn2)) {
2401     return NULL; // Sets are not disjoint
2402   }
2403 
2404   // Sets are disjoint.
2405   bool set1_has_unknown_ptr = ptn1->points_to(phantom_obj);
2406   bool set2_has_unknown_ptr = ptn2->points_to(phantom_obj);
2407   bool set1_has_null_ptr    = ptn1->points_to(null_obj);
2408   bool set2_has_null_ptr    = ptn2->points_to(null_obj);
2409 
2410   if (set1_has_unknown_ptr && set2_has_null_ptr ||
2411       set2_has_unknown_ptr && set1_has_null_ptr) {
2412     // Check nullness of unknown object.
2413     return NULL;
2414   }
2415 
2416   // Disjointness by itself is not sufficient since
2417   // alias analysis is not complete for escaped objects.
2418   // Disjoint sets are definitely unrelated only when
2419   // at least one set has only not escaping allocations.
2420   if (!set1_has_unknown_ptr && !set1_has_null_ptr) {
2421     if (ptn1->not_escaped_allocation()) {











2422       return _pcmp_neq;
2423     }
2424   }
2425   if (!set2_has_unknown_ptr && !set2_has_null_ptr) {
2426     if (ptn2->not_escaped_allocation()) {











2427       return _pcmp_neq;
2428     }
2429   }
2430   return NULL;
2431 }
2432 
2433 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
2434     bool is_arraycopy = false;
2435     switch (call->Opcode()) {
2436 #ifdef ASSERT
2437     case Op_Allocate:
2438     case Op_AllocateArray:
2439     case Op_Lock:
2440     case Op_Unlock:
2441       assert(false, "should be done already");
2442       break;
2443 #endif
2444     case Op_CallLeafNoFP:
2445       is_arraycopy = (call->as_CallLeaf()->_name != NULL &&
2446                       strstr(call->as_CallLeaf()->_name, "arraycopy") != 0);
2447       // fall through
2448     case Op_CallLeaf:
2449     {
2450       // Stub calls, objects do not escape but they are not scale replaceable.
2451       // Adjust escape state for outgoing arguments.
2452       const TypeTuple * d = call->tf()->domain();
2453       bool src_has_oops = false;
2454       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2455         const Type* at = d->field_at(i);
2456         Node *arg = call->in(i);
2457         const Type *aat = phase->type(arg);
2458         if (arg->is_top() || !at->isa_ptr() || !aat->isa_ptr())
2459           continue;
















2460         if (arg->is_AddP()) {
2461           //
2462           // The inline_native_clone() case when the arraycopy stub is called
2463           // after the allocation before Initialize and CheckCastPP nodes.
2464           // Or normal arraycopy for object arrays case.
2465           //
2466           // Set AddP's base (Allocate) as not scalar replaceable since
2467           // pointer to the base (with offset) is passed as argument.
2468           //
2469           arg = get_addp_base(arg);

2470         }
2471         PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2472         assert(arg_ptn != NULL, "should be registered");
2473         PointsToNode::EscapeState arg_esc = arg_ptn->escape_state();
2474         if (is_arraycopy || arg_esc < PointsToNode::ArgEscape) {
2475           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
2476                  aat->isa_ptr() != NULL, "expecting an Ptr");
2477           bool arg_has_oops = aat->isa_oopptr() &&
2478                               (aat->isa_oopptr()->klass() == NULL || aat->isa_instptr() ||
2479                                (aat->isa_aryptr() && aat->isa_aryptr()->klass()->is_obj_array_klass()));
2480           if (i == TypeFunc::Parms) {
2481             src_has_oops = arg_has_oops;
2482           }
2483           //
2484           // src or dst could be j.l.Object when other is basic type array:
2485           //
2486           //   arraycopy(char[],0,Object*,0,size);
2487           //   arraycopy(Object*,0,char[],0,size);
2488           //
2489           // Don't add edges in such cases.
2490           //
2491           bool arg_is_arraycopy_dest = src_has_oops && is_arraycopy &&
2492                                        arg_has_oops && (i > TypeFunc::Parms);
2493 #ifdef ASSERT
2494           if (!(is_arraycopy ||
2495                 call->as_CallLeaf()->_name != NULL &&
2496                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
2497                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
2498           ) {
2499             call->dump();
2500             assert(false, "EA: unexpected CallLeaf");
2501           }
2502 #endif
2503           // Always process arraycopy's destination object since
2504           // we need to add all possible edges to references in
2505           // source object.
2506           if (arg_esc >= PointsToNode::ArgEscape &&
2507               !arg_is_arraycopy_dest) {
2508             continue;
2509           }
2510           set_escape_state(arg_ptn, PointsToNode::ArgEscape);
2511           if (arg_is_arraycopy_dest) {
2512             Node* src = call->in(TypeFunc::Parms);


2513             if (src->is_AddP()) {
2514               src = get_addp_base(src);
2515             }
2516             PointsToNode* src_ptn = ptnode_adr(src->_idx);
2517             assert(src_ptn != NULL, "should be registered");
2518             if (arg_ptn != src_ptn) {
2519               // Special arraycopy edge:
2520               // A destination object's field can't have the source object
2521               // as base since objects escape states are not related.
2522               // Only escape state of destination object's fields affects
2523               // escape state of fields in source object.
2524               add_arraycopy(call, PointsToNode::ArgEscape, src_ptn, arg_ptn);
2525             }
2526           }
2527         }
2528       }
2529       break;
2530     }
2531 
2532     case Op_CallStaticJava:
2533     // For a static call, we know exactly what method is being called.
2534     // Use bytecode estimator to record the call's escape affects
2535     {
2536 #ifdef ASSERT
2537       const char* name = call->as_CallStaticJava()->_name;
2538       assert((name == NULL || strcmp(name, "uncommon_trap") != 0), "normal calls only");
2539 #endif
2540 
2541       ciMethod* meth = call->as_CallJava()->method();
2542       BCEscapeAnalyzer* call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
2543       // fall-through if not a Java method or no analyzer information
2544       if (call_analyzer != NULL) {
2545         PointsToNode* call_ptn = ptnode_adr(call->_idx);
2546         const TypeTuple* d = call->tf()->domain();
2547         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2548           const Type* at = d->field_at(i);
2549           int k = i - TypeFunc::Parms;
2550           Node* arg = call->in(i);
2551           PointsToNode* arg_ptn = ptnode_adr(arg->_idx);
2552           if (at->isa_ptr() != NULL &&
2553               call_analyzer->is_arg_returned(k)) {
2554             // The call returns arguments.
2555             if (call_ptn != NULL) { // Is call's result used?
2556               assert(call_ptn->is_LocalVar(), "node should be registered");
2557               assert(arg_ptn != NULL, "node should be registered");
2558               add_edge(call_ptn, arg_ptn);
2559             }
2560           }
2561           if (at->isa_oopptr() != NULL &&
2562               arg_ptn->escape_state() < PointsToNode::GlobalEscape) {

2563             bool global_escapes = false;
2564             bool fields_escapes = false;
2565             if (!call_analyzer->is_arg_stack(k)) {
2566               // The argument global escapes
2567               set_escape_state(arg_ptn, PointsToNode::GlobalEscape);

2568             } else {
2569               set_escape_state(arg_ptn, PointsToNode::ArgEscape);
2570               if (!call_analyzer->is_arg_local(k)) {
2571                 // The argument itself doesn't escape, but any fields might
2572                 set_fields_escape_state(arg_ptn, PointsToNode::GlobalEscape);
2573               }


2574             }













2575           }
2576         }
2577         if (call_ptn != NULL && call_ptn->is_LocalVar()) {
2578           // The call returns arguments.
2579           assert(call_ptn->edge_count() > 0, "sanity");
2580           if (!call_analyzer->is_return_local()) {
2581             // Returns also unknown object.
2582             add_edge(call_ptn, phantom_obj);
2583           }
2584         }



2585         break;
2586       }
2587     }
2588 
2589     default:
2590     // Fall-through here if not a Java method or no analyzer information
2591     // or some other type of call, assume the worst case: all arguments
2592     // globally escape.
2593     {
2594       const TypeTuple* d = call->tf()->domain();

2595       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2596         const Type* at = d->field_at(i);
2597         if (at->isa_oopptr() != NULL) {
2598           Node* arg = call->in(i);
2599           if (arg->is_AddP()) {
2600             arg = get_addp_base(arg);



2601           }
2602           assert(ptnode_adr(arg->_idx) != NULL, "should be defined already");
2603           set_escape_state(ptnode_adr(arg->_idx), PointsToNode::GlobalEscape);
2604         }
2605       }
2606     }
2607   }
2608 }




2609 
2610 void ConnectionGraph::add_call_node(CallNode* call) {
2611   assert(call->returns_pointer(), "only for call which returns pointer");
2612   uint    call_idx = call->_idx;
2613   if (call->is_Allocate()) {
2614     Node* k = call->in(AllocateNode::KlassNode);
2615     const TypeKlassPtr* kt = k->bottom_type()->isa_klassptr();
2616     assert(kt != NULL, "TypeKlassPtr  required.");
2617     ciKlass* cik = kt->klass();
2618 
2619     PointsToNode::EscapeState es = PointsToNode::NoEscape;
2620     bool scalar_replaceable = true;
2621     if (call->is_AllocateArray()) {

























2622       if (!cik->is_array_klass()) { // StressReflectiveCode
2623         es = PointsToNode::GlobalEscape;

2624       } else {



2625         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
2626         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
2627           // Not scalar replaceable if the length is not constant or too big.
2628           scalar_replaceable = false;
2629         }
2630       }
2631     } else {  // Allocate instance
2632       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
2633          !cik->is_instance_klass() || // StressReflectiveCode
2634           cik->as_instance_klass()->has_finalizer()) {
2635         es = PointsToNode::GlobalEscape;
2636       }
2637     }
2638     add_java_object(call, es);
2639     PointsToNode* ptn = ptnode_adr(call_idx);
2640     if (!scalar_replaceable && ptn->scalar_replaceable())
2641       ptn->set_scalar_replaceable(false);
2642 
2643   } else if (call->is_CallStaticJava()) {
2644     // Call nodes could be different types:
2645     //
2646     // 1. CallDynamicJavaNode (what happened during call is unknown):
2647     //
2648     //    - mapped to GlobalEscape JavaObject node if oop is returned;
2649     //
2650     //    - all oop arguments are escaping globally;
2651     //
2652     // 2. CallStaticJavaNode (execute bytecode analysis if possible):
2653     //
2654     //    - the same as CallDynamicJavaNode if can't do bytecode analysis;
2655     //
2656     //    - mapped to GlobalEscape JavaObject node if unknown oop is returned;
2657     //    - mapped to NoEscape JavaObject node if non escaped object allocated
2658     //      during call is returned;
2659     //    - mapped to ArgEscape LocalVar node pointed to object arguments
2660     //      which are returned and does not escape during call;
2661     //
2662     //    - oop arguments escaping status is defined by bytecode analysis;
2663     //
2664 
2665     // For a static call, we know exactly what method is being called.
2666     // Use bytecode estimator to record whether the call's return value escapes.
2667     ciMethod* meth = call->as_CallJava()->method();








2668     if (meth == NULL) {
2669       const char* name = call->as_CallStaticJava()->_name;
2670       assert(strncmp(name, "_multianewarray", 15) == 0, "TODO: add failed case check");
2671       // Returns a newly allocated unescaped object.
2672       add_java_object(call, PointsToNode::NoEscape);
2673       ptnode_adr(call_idx)->set_scalar_replaceable(false);
2674     } else {
2675       BCEscapeAnalyzer* call_analyzer = meth->get_bcea();
2676       call_analyzer->copy_dependencies(_compile->dependencies());

2677       if (call_analyzer->is_return_allocated()) {
2678         // Returns a newly allocated unescaped object, simply
2679         // update dependency information.
2680         // Mark it as NoEscape so that objects referenced by
2681         // it's fields will be marked as NoEscape at least.
2682         add_java_object(call, PointsToNode::NoEscape);
2683         ptnode_adr(call_idx)->set_scalar_replaceable(false);




2684       } else {
2685         // Determine whether any arguments are returned.
2686         const TypeTuple* d = call->tf()->domain();
2687         bool ret_arg = false;
2688         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
2689           if (d->field_at(i)->isa_ptr() != NULL &&
2690               call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {



2691             ret_arg = true;
2692             break;






2693           }
2694         }
2695         if (ret_arg) {
2696           add_local_var(call, PointsToNode::ArgEscape);
2697         } else {


2698           // Returns unknown object.
2699           map_ideal_node(call, phantom_obj);
2700         }
2701       }
2702     }
2703   } else {
2704     // An other type of call, assume the worst case:
2705     // returned value is unknown and globally escapes.
2706     assert(call->Opcode() == Op_CallDynamicJava, "add failed case check");
2707     map_ideal_node(call, phantom_obj);
2708   }
2709 }



2710 
2711 // Populate Connection Graph with PointsTo nodes and create simple
2712 // connection graph edges.
2713 void ConnectionGraph::build_connection_graph(Node *n,
2714                                              Unique_Node_List *delayed_worklist,
2715                                              PhaseTransform *phase) {
2716   // During first iteration create PointsTo nodes and simple edges.
2717   // During second iteration create the rest of edges.
2718   bool first_iteration = (delayed_worklist != NULL);
2719 
2720   uint n_idx = n->_idx;
2721   PointsToNode* n_ptn = ptnode_adr(n_idx);
2722   if (first_iteration && n_ptn != NULL)
2723     return; // No need to redefine PointsTo node during first iteration.







2724 
2725 #ifdef ASSERT
2726   if (_verify && n_ptn->is_JavaObject())
2727     return; // Following code for JavaObject does not change graph.
2728 #endif


2729 
2730   if (n->is_Call()) {
2731     if (!first_iteration) {
2732       process_call_arguments(n->as_Call(), phase);
2733       return;
2734     }
2735     // Arguments to allocation and locking don't escape.
2736     if (n->is_AbstractLock()) {



2737       // Put Lock and Unlock nodes on IGVN worklist to process them during
2738       // first IGVN optimization when escape information is still available.
2739       record_for_optimizer(n);
2740     } else if (n->is_Allocate()) {
2741       add_call_node(n->as_Call());
2742       record_for_optimizer(n);
2743     } else {
2744       if (n->is_CallStaticJava()) {
2745         const char* name = n->as_CallStaticJava()->_name;
2746         if (name != NULL && strcmp(name, "uncommon_trap") == 0)
2747           return; // Skip uncommon traps
2748       }
2749       // Don't mark as processed since call's arguments have to be processed.
2750       delayed_worklist->push(n);

2751 
2752       // Check if a call returns an object.
2753       if (n->as_Call()->returns_pointer() &&


2754           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
2755         add_call_node(n->as_Call());




2756       }
2757     }


2758     return;
2759   }
2760 
2761   // Put this check here to process call arguments since some call nodes
2762   // point to phantom_obj.
2763   if (n_ptn == phantom_obj || n_ptn == null_obj)
2764     return; // Skip predefined nodes.
2765 
2766   assert(first_iteration || n->is_Store() || n->is_LoadStore() ||
2767          n_ptn != NULL && n_ptn->ideal_node() != NULL,
2768          "node should be registered during second iteration");
2769 
2770   int opcode = n->Opcode();
2771   switch (opcode) {
2772     case Op_AddP:
2773     {
2774       Node* base = get_addp_base(n);
2775       PointsToNode* ptn = ptnode_adr(base->_idx);
2776       if (first_iteration) {
2777         // Field node is created for all field types. It will help in
2778         // split_unique_types(). Note, there will be no uses of non oop fields
2779         // in Connection Graph.
2780         int offset = address_offset(n, phase);
2781         add_field(n, PointsToNode::NoEscape, offset);
2782         if (ptn == NULL) {
2783           delayed_worklist->push(n);
2784           return; // Process it later.
2785         }
2786         n_ptn = ptnode_adr(n_idx);
2787       } else {
2788         assert(ptn != NULL, "node should be registered");
2789       }
2790       add_base(n_ptn->as_Field(), ptn);
2791       break;
2792     }
2793     case Op_CastX2P:
2794     {
2795       if (first_iteration) {
2796         // "Unsafe" memory access to unknown object.
2797         map_ideal_node(n, phantom_obj);
2798       } else {
2799         assert(false, "Op_CastX2P");
2800       }
2801       break;
2802     }
2803     case Op_CastPP:
2804     case Op_CheckCastPP:
2805     case Op_EncodeP:
2806     case Op_DecodeN:
2807     {
2808       add_local_var_and_edge(n, PointsToNode::NoEscape,
2809                              n->in(1), delayed_worklist);



2810       break;




2811     }
2812     case Op_CMoveP:



2813     {
2814       if (first_iteration) {
2815         add_local_var(n, PointsToNode::NoEscape);
2816         // Do not add edges during first iteration because some could be
2817         // not defined yet.
2818         delayed_worklist->push(n);
2819         return; // Process it later.
2820       } else {
2821         for (uint i = CMoveNode::IfFalse; i < n->req(); i++) {



































































2822           Node* in = n->in(i);
2823           if (in == NULL)
2824             continue;  // ignore NULL
2825           Node* uncast_in = in->uncast();
2826           if (uncast_in->is_top() || uncast_in == n)
2827             continue;  // ignore top or inputs which go back this node























































































































2828 
2829           PointsToNode* ptn = ptnode_adr(in->_idx);
2830           assert(ptn != NULL, "node should be registered");
2831           add_edge(n_ptn, ptn);












2832         }










2833       }
2834       break;
2835     }
2836     case Op_ConP:
2837     case Op_ConN:
2838     {
2839       // assume all oop constants globally escape except for null
2840       if (first_iteration) {
2841         PointsToNode::EscapeState es;
2842         if (phase->type(n) == TypePtr::NULL_PTR ||
2843             phase->type(n) == TypeNarrowOop::NULL_PTR) {
2844           es = PointsToNode::NoEscape;






2845         } else {
2846           es = PointsToNode::GlobalEscape;
2847         }
2848         add_java_object(n, es);
2849       } else {



2850         assert(false, "Op_ConP");

2851       }



2852       break;
2853     }
2854     case Op_CreateEx:
2855     {
2856       if (first_iteration) {
2857         // assume that all exception objects globally escape
2858         add_java_object(n, PointsToNode::GlobalEscape);
2859       } else {
2860         assert(false, "Op_CreateEx");
2861       }
2862       break;
2863     }
2864     case Op_LoadKlass:
2865     case Op_LoadNKlass:
2866     {
2867       if (first_iteration) {
2868         // Unknown class is loaded
2869         map_ideal_node(n, phantom_obj);
2870       } else {
2871         assert(false, "Op_LoadKlass");
2872       }
2873       break;
2874     }
2875     case Op_LoadP:
2876     case Op_LoadN:
2877     case Op_LoadPLocked:
2878     {
2879       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2880       // ThreadLocal has RawPrt type.
2881       const Type* t = phase->type(n);
2882       if (t->make_ptr() != NULL) {
2883         Node* adr = n->in(MemNode::Address);
2884         if (!adr->is_AddP()) {
2885           assert(phase->type(adr)->isa_rawptr(), "sanity");
2886         } else {
2887           assert((ptnode_adr(adr->_idx) == NULL ||
2888                   ptnode_adr(adr->_idx)->as_Field()->is_oop()), "sanity");
2889         }
2890         add_local_var_and_edge(n, PointsToNode::NoEscape,
2891                                adr, delayed_worklist);
2892 #ifdef ASSERT
2893       } else if (!first_iteration) {
2894         n->dump(1);
2895         assert(false, "Op_LoadP");
2896 #endif







2897       }












2898       break;
2899     }
2900     case Op_Parm:
2901     {
2902       if (first_iteration) {
2903         // We have to assume all input parameters globally escape
2904         map_ideal_node(n, phantom_obj);
2905       } else {
2906         assert(false, "Op_Parm");
2907       }
2908       break;
2909     }
2910     case Op_PartialSubtypeCheck:
2911     {
2912       if (first_iteration) {
2913         // Produces Null or notNull and is used in only in CmpP so
2914         // phantom_obj could be used.
2915         map_ideal_node(n, phantom_obj); // Result is unknown
2916       } else {
2917         // Arguments are klasses which globally escape so do not need
2918         // to point to them.
2919         assert(false, "Op_PartialSubtypeCheck");
2920       }
2921       break;
2922     }
2923     case Op_Phi:
2924     {
2925       // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
2926       // ThreadLocal has RawPrt type.
2927       const Type* t = n->as_Phi()->type();
2928       if (t->make_ptr() != NULL) {
2929         if (first_iteration) {
2930           add_local_var(n, PointsToNode::NoEscape);
2931           // Do not add edges during first iteration because some could be
2932           // not defined yet.
2933           delayed_worklist->push(n);
2934           return; // Process it later.
2935         } else {
2936           for (uint i = 1; i < n->req(); i++) {
2937             Node* in = n->in(i);
2938             if (in == NULL)
2939               continue;  // ignore NULL
2940             Node* uncast_in = in->uncast();
2941             if (uncast_in->is_top() || uncast_in == n)
2942               continue;  // ignore top or inputs which go back this node
2943 
2944             PointsToNode* ptn = ptnode_adr(in->_idx);
2945             assert(ptn != NULL, "node should be registered");
2946             add_edge(n_ptn, ptn);



2947           }
2948         }
2949 #ifdef ASSERT
2950       } else if (!first_iteration) {
2951         n->dump(1);
2952         assert(false, "Op_Phi");
2953 #endif
2954       }
2955       break;
2956     }
2957     case Op_Proj:
2958     {
2959       // we are only interested in the oop result projection from a call
2960       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() &&
2961           n->in(0)->as_Call()->returns_pointer()) {
2962         add_local_var_and_edge(n, PointsToNode::NoEscape,
2963                                n->in(0), delayed_worklist);
2964 #ifdef ASSERT
2965       } else if (!first_iteration) {
2966         n->dump(1);




2967         assert(false, "Op_Proj");
2968 #endif
2969       }
2970       break;
2971     }
2972     case Op_Rethrow: // Exception object escapes
2973     case Op_Return:
2974     {
2975       if (n->req() > TypeFunc::Parms &&
2976           phase->type(n->in(TypeFunc::Parms))->isa_oopptr()) {
2977         // Treat Return value as LocalVar with GlobalEscape escape state.
2978         add_local_var_and_edge(n, PointsToNode::GlobalEscape,
2979                                n->in(TypeFunc::Parms), delayed_worklist);
2980 #ifdef ASSERT
2981       } else if (!first_iteration) {

2982         assert(false, "Op_Return");

2983 #endif






2984       }

2985       break;
2986     }
2987     case Op_StoreP:
2988     case Op_StoreN:
2989     case Op_StorePConditional:
2990     case Op_CompareAndSwapP:
2991     case Op_CompareAndSwapN:
2992     {
2993       Node* adr = n->in(MemNode::Address);
2994       const Type *adr_type = phase->type(adr);
2995       adr_type = adr_type->make_ptr();
2996       if (adr_type->isa_oopptr() ||
2997           (opcode == Op_StoreP || opcode == Op_StoreN) &&
2998                         (adr_type == TypeRawPtr::NOTNULL &&
2999                          adr->in(AddPNode::Address)->is_Proj() &&
3000                          adr->in(AddPNode::Address)->in(0)->is_Allocate())) {
3001 #ifdef ASSERT
3002         assert(adr->is_AddP(), "expecting an AddP");
3003         if (adr_type == TypeRawPtr::NOTNULL) {
3004           // Verify a raw address for a store captured by Initialize node.
3005           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
3006           assert(offs != Type::OffsetBot, "offset must be a constant");
3007         }
3008 #endif
3009         if (first_iteration) {
3010           delayed_worklist->push(n);
3011           return; // Process it later.
3012         } else {
3013           // Point Address to Value
3014           PointsToNode* adr_ptn = ptnode_adr(adr->_idx);
3015           assert(adr_ptn != NULL &&
3016                  adr_ptn->as_Field()->is_oop(), "node should be registered");
3017           Node *val = n->in(MemNode::ValueIn);
3018           PointsToNode* ptn = ptnode_adr(val->_idx);
3019           assert(ptn != NULL, "node should be registered");
3020           add_edge(adr_ptn, ptn);
3021         }
3022 #ifdef ASSERT
3023       } else {
3024         // Ignore copy the displaced header to the BoxNode (OSR compilation).
3025         if (adr->is_BoxLock())
3026           break;
3027 
3028         if (!adr->is_AddP()) {
3029           n->dump(1);
3030           assert(adr->is_AddP(), "expecting an AddP");










3031         }
3032         // Ignore G1 barrier's stores.
3033         if (!UseG1GC || (opcode != Op_StoreP) ||
3034             (adr_type != TypeRawPtr::BOTTOM)) {
3035           n->dump(1);
3036           assert(false, "not G1 barrier raw StoreP");
3037         }
3038 #endif
3039       }
3040       break;
3041     }
3042     case Op_AryEq:
3043     case Op_StrComp:
3044     case Op_StrEquals:
3045     case Op_StrIndexOf:
3046     {
3047       if (first_iteration) {
3048         add_local_var(n, PointsToNode::ArgEscape);
3049         delayed_worklist->push(n);
3050         return; // Process it later.
3051       } else {
3052         // char[] arrays passed to string intrinsic do not escape but
3053         // they are not scalar replaceable. Adjust escape state for them.
3054         // Start from in(2) edge since in(1) is memory edge.
3055         for (uint i = 2; i < n->req(); i++) {
3056           Node* adr = n->in(i);
3057           const Type* at = phase->type(adr);
3058           if (!adr->is_top() && at->isa_ptr()) {
3059             assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
3060                    at->isa_ptr() != NULL, "expecting a pointer");
3061             if (adr->is_AddP()) {
3062               adr = get_addp_base(adr);
3063             }
3064             PointsToNode* ptn = ptnode_adr(adr->_idx);
3065             assert(ptn != NULL, "node should be registered");
3066             add_edge(n_ptn, ptn);
3067           }
3068         }
3069       }
3070       break;
3071     }
3072     case Op_ThreadLocal:
3073     {
3074       if (first_iteration) {
3075         add_java_object(n, PointsToNode::ArgEscape);
3076       } else {
3077         assert(false, "Op_ThreadLocal");
3078       }
3079       break;
3080     }
3081     default:
3082       // During first iteration (when all ideal nodes are scanned) do nothing
3083       // for nodes not related to EA. During second iteration this method
3084       // should be called only for EA specific nodes.
3085       if (!first_iteration) {
3086         ShouldNotReachHere();
3087       }
3088   }
3089   return;
3090 }
3091 
3092 #ifndef PRODUCT
3093 static const char *node_type_names[] = {
3094   "UnknownType",
3095   "JavaObject",
3096   "LocalVar",
3097   "Field",
3098   "Arraycopy"
3099 };
3100 
3101 static const char *esc_names[] = {
3102   "UnknownEscape",
3103   "NoEscape",
3104   "ArgEscape",
3105   "GlobalEscape"
3106 };
3107 
3108 void PointsToNode::dump(bool print_state) const {
3109   NodeType nt = node_type();
3110   tty->print("%s ", node_type_names[(int) nt]);
3111   if (print_state) {
3112     EscapeState es = escape_state();
3113     EscapeState fields_es = fields_escape_state();
3114     tty->print("%s(%s) ", esc_names[(int)es], esc_names[(int)fields_es]);
3115     if (nt == PointsToNode::JavaObject && !this->scalar_replaceable())
3116       tty->print("NSR");
3117   }
3118   if (is_Field()) {
3119     FieldNode* f = (FieldNode*)this;
3120     tty->print("(");
3121     for (uint i = 0; i < f->base_count(); i++) {
3122       PointsToNode* b = f->base(i);
3123       tty->print(" %d%s", b->idx(),(b->is_JavaObject() ? "P" : ""));
3124     }
3125     tty->print(" )");
3126   }
3127   tty->print("[");
3128   for (uint i = 0; i < edge_count(); i++) {
3129     PointsToNode* e = edge(i);
3130     tty->print(" %d%s%s", e->idx(),(e->is_JavaObject() ? "P" : (e->is_Field() ? "F" : "")), e->is_Arraycopy() ? "cp" : "");
3131   }
3132   tty->print(" [");
3133   for (uint i = 0; i < use_count(); i++) {
3134     PointsToNode* u = use(i);
3135     bool is_base = false;
3136     if (PointsToNode::is_base_use(u)) {
3137       is_base = true;
3138       u = PointsToNode::get_use_node(u)->as_Field();
3139     }
3140     tty->print(" %d%s%s", u->idx(), is_base ? "b" : "", u->is_Arraycopy() ? "cp" : "");
3141   }
3142   tty->print(" ]]  ");
3143   if (_node == NULL)
3144     tty->print_cr("<null>");
3145   else
3146     _node->dump();
3147 }
3148 
3149 void ConnectionGraph::dump(GrowableArray<PointsToNode*>& ptnodes_worklist) {
3150   bool first = true;
3151 
3152   uint ptnodes_length = ptnodes_worklist.length();
3153   for (uint i = 0; i < ptnodes_length; i++) {
3154     PointsToNode *ptn = ptnodes_worklist.at(i);
3155     if (ptn == NULL || !ptn->is_JavaObject())
3156       continue;
3157     PointsToNode::EscapeState es = ptn->escape_state();
3158     if (ptn->ideal_node()->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
3159       if (first) {
3160         tty->cr();
3161         tty->print("======== Connection graph for ");
3162         _compile->method()->print_short_name();
3163         tty->cr();
3164         first = false;
3165       }

3166       ptn->dump();
3167       // Print all locals and fields which reference this allocation
3168       uint count = ptn->use_count();
3169       for (uint i = 0; i < count; i++) {
3170         PointsToNode* use = ptn->use(i);
3171         if (use->is_LocalVar()) {
3172           use->dump(Verbose);
3173         } else if (Verbose) {
3174           use->dump();
3175         }
3176       }







3177       tty->cr();
3178     }
3179   }
3180 }
3181 #endif
src/share/vm/opto/escape.cpp
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