src/share/vm/opto/escape.cpp

Fri, 20 Aug 2010 23:40:30 -0700

author
jrose
date
Fri, 20 Aug 2010 23:40:30 -0700
changeset 2101
4b29a725c43c
parent 1989
60a14ad85270
child 2170
5867d89c129b
permissions
-rw-r--r--

6912064: type profiles need to be exploited more for dynamic language support
Reviewed-by: kvn

     1 /*
     2  * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "incls/_precompiled.incl"
    26 #include "incls/_escape.cpp.incl"
    28 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
    29   uint v = (targIdx << EdgeShift) + ((uint) et);
    30   if (_edges == NULL) {
    31      Arena *a = Compile::current()->comp_arena();
    32     _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
    33   }
    34   _edges->append_if_missing(v);
    35 }
    37 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
    38   uint v = (targIdx << EdgeShift) + ((uint) et);
    40   _edges->remove(v);
    41 }
    43 #ifndef PRODUCT
    44 static const char *node_type_names[] = {
    45   "UnknownType",
    46   "JavaObject",
    47   "LocalVar",
    48   "Field"
    49 };
    51 static const char *esc_names[] = {
    52   "UnknownEscape",
    53   "NoEscape",
    54   "ArgEscape",
    55   "GlobalEscape"
    56 };
    58 static const char *edge_type_suffix[] = {
    59  "?", // UnknownEdge
    60  "P", // PointsToEdge
    61  "D", // DeferredEdge
    62  "F"  // FieldEdge
    63 };
    65 void PointsToNode::dump(bool print_state) const {
    66   NodeType nt = node_type();
    67   tty->print("%s ", node_type_names[(int) nt]);
    68   if (print_state) {
    69     EscapeState es = escape_state();
    70     tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
    71   }
    72   tty->print("[[");
    73   for (uint i = 0; i < edge_count(); i++) {
    74     tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
    75   }
    76   tty->print("]]  ");
    77   if (_node == NULL)
    78     tty->print_cr("<null>");
    79   else
    80     _node->dump();
    81 }
    82 #endif
    84 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
    85   _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
    86   _processed(C->comp_arena()),
    87   _collecting(true),
    88   _compile(C),
    89   _igvn(igvn),
    90   _node_map(C->comp_arena()) {
    92   _phantom_object = C->top()->_idx,
    93   add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
    95   // Add ConP(#NULL) and ConN(#NULL) nodes.
    96   Node* oop_null = igvn->zerocon(T_OBJECT);
    97   _oop_null = oop_null->_idx;
    98   assert(_oop_null < C->unique(), "should be created already");
    99   add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   101   if (UseCompressedOops) {
   102     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   103     _noop_null = noop_null->_idx;
   104     assert(_noop_null < C->unique(), "should be created already");
   105     add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   106   }
   107 }
   109 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
   110   PointsToNode *f = ptnode_adr(from_i);
   111   PointsToNode *t = ptnode_adr(to_i);
   113   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   114   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
   115   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
   116   f->add_edge(to_i, PointsToNode::PointsToEdge);
   117 }
   119 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
   120   PointsToNode *f = ptnode_adr(from_i);
   121   PointsToNode *t = ptnode_adr(to_i);
   123   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   124   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
   125   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
   126   // don't add a self-referential edge, this can occur during removal of
   127   // deferred edges
   128   if (from_i != to_i)
   129     f->add_edge(to_i, PointsToNode::DeferredEdge);
   130 }
   132 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
   133   const Type *adr_type = phase->type(adr);
   134   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
   135       adr->in(AddPNode::Address)->is_Proj() &&
   136       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
   137     // We are computing a raw address for a store captured by an Initialize
   138     // compute an appropriate address type. AddP cases #3 and #5 (see below).
   139     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
   140     assert(offs != Type::OffsetBot ||
   141            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
   142            "offset must be a constant or it is initialization of array");
   143     return offs;
   144   }
   145   const TypePtr *t_ptr = adr_type->isa_ptr();
   146   assert(t_ptr != NULL, "must be a pointer type");
   147   return t_ptr->offset();
   148 }
   150 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
   151   PointsToNode *f = ptnode_adr(from_i);
   152   PointsToNode *t = ptnode_adr(to_i);
   154   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   155   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
   156   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
   157   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
   158   t->set_offset(offset);
   160   f->add_edge(to_i, PointsToNode::FieldEdge);
   161 }
   163 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
   164   PointsToNode *npt = ptnode_adr(ni);
   165   PointsToNode::EscapeState old_es = npt->escape_state();
   166   if (es > old_es)
   167     npt->set_escape_state(es);
   168 }
   170 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
   171                                PointsToNode::EscapeState es, bool done) {
   172   PointsToNode* ptadr = ptnode_adr(n->_idx);
   173   ptadr->_node = n;
   174   ptadr->set_node_type(nt);
   176   // inline set_escape_state(idx, es);
   177   PointsToNode::EscapeState old_es = ptadr->escape_state();
   178   if (es > old_es)
   179     ptadr->set_escape_state(es);
   181   if (done)
   182     _processed.set(n->_idx);
   183 }
   185 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
   186   uint idx = n->_idx;
   187   PointsToNode::EscapeState es;
   189   // If we are still collecting or there were no non-escaping allocations
   190   // we don't know the answer yet
   191   if (_collecting)
   192     return PointsToNode::UnknownEscape;
   194   // if the node was created after the escape computation, return
   195   // UnknownEscape
   196   if (idx >= nodes_size())
   197     return PointsToNode::UnknownEscape;
   199   es = ptnode_adr(idx)->escape_state();
   201   // if we have already computed a value, return it
   202   if (es != PointsToNode::UnknownEscape &&
   203       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
   204     return es;
   206   // PointsTo() calls n->uncast() which can return a new ideal node.
   207   if (n->uncast()->_idx >= nodes_size())
   208     return PointsToNode::UnknownEscape;
   210   PointsToNode::EscapeState orig_es = es;
   212   // compute max escape state of anything this node could point to
   213   VectorSet ptset(Thread::current()->resource_area());
   214   PointsTo(ptset, n);
   215   for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
   216     uint pt = i.elem;
   217     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
   218     if (pes > es)
   219       es = pes;
   220   }
   221   if (orig_es != es) {
   222     // cache the computed escape state
   223     assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
   224     ptnode_adr(idx)->set_escape_state(es);
   225   } // orig_es could be PointsToNode::UnknownEscape
   226   return es;
   227 }
   229 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n) {
   230   VectorSet visited(Thread::current()->resource_area());
   231   GrowableArray<uint>  worklist;
   233 #ifdef ASSERT
   234   Node *orig_n = n;
   235 #endif
   237   n = n->uncast();
   238   PointsToNode* npt = ptnode_adr(n->_idx);
   240   // If we have a JavaObject, return just that object
   241   if (npt->node_type() == PointsToNode::JavaObject) {
   242     ptset.set(n->_idx);
   243     return;
   244   }
   245 #ifdef ASSERT
   246   if (npt->_node == NULL) {
   247     if (orig_n != n)
   248       orig_n->dump();
   249     n->dump();
   250     assert(npt->_node != NULL, "unregistered node");
   251   }
   252 #endif
   253   worklist.push(n->_idx);
   254   while(worklist.length() > 0) {
   255     int ni = worklist.pop();
   256     if (visited.test_set(ni))
   257       continue;
   259     PointsToNode* pn = ptnode_adr(ni);
   260     // ensure that all inputs of a Phi have been processed
   261     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
   263     int edges_processed = 0;
   264     uint e_cnt = pn->edge_count();
   265     for (uint e = 0; e < e_cnt; e++) {
   266       uint etgt = pn->edge_target(e);
   267       PointsToNode::EdgeType et = pn->edge_type(e);
   268       if (et == PointsToNode::PointsToEdge) {
   269         ptset.set(etgt);
   270         edges_processed++;
   271       } else if (et == PointsToNode::DeferredEdge) {
   272         worklist.push(etgt);
   273         edges_processed++;
   274       } else {
   275         assert(false,"neither PointsToEdge or DeferredEdge");
   276       }
   277     }
   278     if (edges_processed == 0) {
   279       // no deferred or pointsto edges found.  Assume the value was set
   280       // outside this method.  Add the phantom object to the pointsto set.
   281       ptset.set(_phantom_object);
   282     }
   283   }
   284 }
   286 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
   287   // This method is most expensive during ConnectionGraph construction.
   288   // Reuse vectorSet and an additional growable array for deferred edges.
   289   deferred_edges->clear();
   290   visited->Clear();
   292   visited->set(ni);
   293   PointsToNode *ptn = ptnode_adr(ni);
   295   // Mark current edges as visited and move deferred edges to separate array.
   296   for (uint i = 0; i < ptn->edge_count(); ) {
   297     uint t = ptn->edge_target(i);
   298 #ifdef ASSERT
   299     assert(!visited->test_set(t), "expecting no duplications");
   300 #else
   301     visited->set(t);
   302 #endif
   303     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
   304       ptn->remove_edge(t, PointsToNode::DeferredEdge);
   305       deferred_edges->append(t);
   306     } else {
   307       i++;
   308     }
   309   }
   310   for (int next = 0; next < deferred_edges->length(); ++next) {
   311     uint t = deferred_edges->at(next);
   312     PointsToNode *ptt = ptnode_adr(t);
   313     uint e_cnt = ptt->edge_count();
   314     for (uint e = 0; e < e_cnt; e++) {
   315       uint etgt = ptt->edge_target(e);
   316       if (visited->test_set(etgt))
   317         continue;
   319       PointsToNode::EdgeType et = ptt->edge_type(e);
   320       if (et == PointsToNode::PointsToEdge) {
   321         add_pointsto_edge(ni, etgt);
   322         if(etgt == _phantom_object) {
   323           // Special case - field set outside (globally escaping).
   324           ptn->set_escape_state(PointsToNode::GlobalEscape);
   325         }
   326       } else if (et == PointsToNode::DeferredEdge) {
   327         deferred_edges->append(etgt);
   328       } else {
   329         assert(false,"invalid connection graph");
   330       }
   331     }
   332   }
   333 }
   336 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
   337 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
   338 //  a pointsto edge is added if it is a JavaObject
   340 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
   341   PointsToNode* an = ptnode_adr(adr_i);
   342   PointsToNode* to = ptnode_adr(to_i);
   343   bool deferred = (to->node_type() == PointsToNode::LocalVar);
   345   for (uint fe = 0; fe < an->edge_count(); fe++) {
   346     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   347     int fi = an->edge_target(fe);
   348     PointsToNode* pf = ptnode_adr(fi);
   349     int po = pf->offset();
   350     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   351       if (deferred)
   352         add_deferred_edge(fi, to_i);
   353       else
   354         add_pointsto_edge(fi, to_i);
   355     }
   356   }
   357 }
   359 // Add a deferred  edge from node given by "from_i" to any field of adr_i
   360 // whose offset matches "offset".
   361 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
   362   PointsToNode* an = ptnode_adr(adr_i);
   363   for (uint fe = 0; fe < an->edge_count(); fe++) {
   364     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   365     int fi = an->edge_target(fe);
   366     PointsToNode* pf = ptnode_adr(fi);
   367     int po = pf->offset();
   368     if (pf->edge_count() == 0) {
   369       // we have not seen any stores to this field, assume it was set outside this method
   370       add_pointsto_edge(fi, _phantom_object);
   371     }
   372     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   373       add_deferred_edge(from_i, fi);
   374     }
   375   }
   376 }
   378 // Helper functions
   380 static Node* get_addp_base(Node *addp) {
   381   assert(addp->is_AddP(), "must be AddP");
   382   //
   383   // AddP cases for Base and Address inputs:
   384   // case #1. Direct object's field reference:
   385   //     Allocate
   386   //       |
   387   //     Proj #5 ( oop result )
   388   //       |
   389   //     CheckCastPP (cast to instance type)
   390   //      | |
   391   //     AddP  ( base == address )
   392   //
   393   // case #2. Indirect object's field reference:
   394   //      Phi
   395   //       |
   396   //     CastPP (cast to instance type)
   397   //      | |
   398   //     AddP  ( base == address )
   399   //
   400   // case #3. Raw object's field reference for Initialize node:
   401   //      Allocate
   402   //        |
   403   //      Proj #5 ( oop result )
   404   //  top   |
   405   //     \  |
   406   //     AddP  ( base == top )
   407   //
   408   // case #4. Array's element reference:
   409   //   {CheckCastPP | CastPP}
   410   //     |  | |
   411   //     |  AddP ( array's element offset )
   412   //     |  |
   413   //     AddP ( array's offset )
   414   //
   415   // case #5. Raw object's field reference for arraycopy stub call:
   416   //          The inline_native_clone() case when the arraycopy stub is called
   417   //          after the allocation before Initialize and CheckCastPP nodes.
   418   //      Allocate
   419   //        |
   420   //      Proj #5 ( oop result )
   421   //       | |
   422   //       AddP  ( base == address )
   423   //
   424   // case #6. Constant Pool, ThreadLocal, CastX2P or
   425   //          Raw object's field reference:
   426   //      {ConP, ThreadLocal, CastX2P, raw Load}
   427   //  top   |
   428   //     \  |
   429   //     AddP  ( base == top )
   430   //
   431   // case #7. Klass's field reference.
   432   //      LoadKlass
   433   //       | |
   434   //       AddP  ( base == address )
   435   //
   436   // case #8. narrow Klass's field reference.
   437   //      LoadNKlass
   438   //       |
   439   //      DecodeN
   440   //       | |
   441   //       AddP  ( base == address )
   442   //
   443   Node *base = addp->in(AddPNode::Base)->uncast();
   444   if (base->is_top()) { // The AddP case #3 and #6.
   445     base = addp->in(AddPNode::Address)->uncast();
   446     while (base->is_AddP()) {
   447       // Case #6 (unsafe access) may have several chained AddP nodes.
   448       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
   449       base = base->in(AddPNode::Address)->uncast();
   450     }
   451     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
   452            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
   453            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
   454            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
   455   }
   456   return base;
   457 }
   459 static Node* find_second_addp(Node* addp, Node* n) {
   460   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
   462   Node* addp2 = addp->raw_out(0);
   463   if (addp->outcnt() == 1 && addp2->is_AddP() &&
   464       addp2->in(AddPNode::Base) == n &&
   465       addp2->in(AddPNode::Address) == addp) {
   467     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
   468     //
   469     // Find array's offset to push it on worklist first and
   470     // as result process an array's element offset first (pushed second)
   471     // to avoid CastPP for the array's offset.
   472     // Otherwise the inserted CastPP (LocalVar) will point to what
   473     // the AddP (Field) points to. Which would be wrong since
   474     // the algorithm expects the CastPP has the same point as
   475     // as AddP's base CheckCastPP (LocalVar).
   476     //
   477     //    ArrayAllocation
   478     //     |
   479     //    CheckCastPP
   480     //     |
   481     //    memProj (from ArrayAllocation CheckCastPP)
   482     //     |  ||
   483     //     |  ||   Int (element index)
   484     //     |  ||    |   ConI (log(element size))
   485     //     |  ||    |   /
   486     //     |  ||   LShift
   487     //     |  ||  /
   488     //     |  AddP (array's element offset)
   489     //     |  |
   490     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
   491     //     | / /
   492     //     AddP (array's offset)
   493     //      |
   494     //     Load/Store (memory operation on array's element)
   495     //
   496     return addp2;
   497   }
   498   return NULL;
   499 }
   501 //
   502 // Adjust the type and inputs of an AddP which computes the
   503 // address of a field of an instance
   504 //
   505 bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
   506   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
   507   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
   508   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
   509   if (t == NULL) {
   510     // We are computing a raw address for a store captured by an Initialize
   511     // compute an appropriate address type (cases #3 and #5).
   512     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
   513     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
   514     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
   515     assert(offs != Type::OffsetBot, "offset must be a constant");
   516     t = base_t->add_offset(offs)->is_oopptr();
   517   }
   518   int inst_id =  base_t->instance_id();
   519   assert(!t->is_known_instance() || t->instance_id() == inst_id,
   520                              "old type must be non-instance or match new type");
   522   // The type 't' could be subclass of 'base_t'.
   523   // As result t->offset() could be large then base_t's size and it will
   524   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
   525   // constructor verifies correctness of the offset.
   526   //
   527   // It could happened on subclass's branch (from the type profiling
   528   // inlining) which was not eliminated during parsing since the exactness
   529   // of the allocation type was not propagated to the subclass type check.
   530   //
   531   // Or the type 't' could be not related to 'base_t' at all.
   532   // It could happened when CHA type is different from MDO type on a dead path
   533   // (for example, from instanceof check) which is not collapsed during parsing.
   534   //
   535   // Do nothing for such AddP node and don't process its users since
   536   // this code branch will go away.
   537   //
   538   if (!t->is_known_instance() &&
   539       !base_t->klass()->is_subtype_of(t->klass())) {
   540      return false; // bail out
   541   }
   543   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
   544   // Do NOT remove the next line: ensure a new alias index is allocated
   545   // for the instance type. Note: C++ will not remove it since the call
   546   // has side effect.
   547   int alias_idx = _compile->get_alias_index(tinst);
   548   igvn->set_type(addp, tinst);
   549   // record the allocation in the node map
   550   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
   551   set_map(addp->_idx, get_map(base->_idx));
   553   // Set addp's Base and Address to 'base'.
   554   Node *abase = addp->in(AddPNode::Base);
   555   Node *adr   = addp->in(AddPNode::Address);
   556   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
   557       adr->in(0)->_idx == (uint)inst_id) {
   558     // Skip AddP cases #3 and #5.
   559   } else {
   560     assert(!abase->is_top(), "sanity"); // AddP case #3
   561     if (abase != base) {
   562       igvn->hash_delete(addp);
   563       addp->set_req(AddPNode::Base, base);
   564       if (abase == adr) {
   565         addp->set_req(AddPNode::Address, base);
   566       } else {
   567         // AddP case #4 (adr is array's element offset AddP node)
   568 #ifdef ASSERT
   569         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
   570         assert(adr->is_AddP() && atype != NULL &&
   571                atype->instance_id() == inst_id, "array's element offset should be processed first");
   572 #endif
   573       }
   574       igvn->hash_insert(addp);
   575     }
   576   }
   577   // Put on IGVN worklist since at least addp's type was changed above.
   578   record_for_optimizer(addp);
   579   return true;
   580 }
   582 //
   583 // Create a new version of orig_phi if necessary. Returns either the newly
   584 // created phi or an existing phi.  Sets create_new to indicate wheter  a new
   585 // phi was created.  Cache the last newly created phi in the node map.
   586 //
   587 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
   588   Compile *C = _compile;
   589   new_created = false;
   590   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
   591   // nothing to do if orig_phi is bottom memory or matches alias_idx
   592   if (phi_alias_idx == alias_idx) {
   593     return orig_phi;
   594   }
   595   // Have we recently created a Phi for this alias index?
   596   PhiNode *result = get_map_phi(orig_phi->_idx);
   597   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
   598     return result;
   599   }
   600   // Previous check may fail when the same wide memory Phi was split into Phis
   601   // for different memory slices. Search all Phis for this region.
   602   if (result != NULL) {
   603     Node* region = orig_phi->in(0);
   604     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
   605       Node* phi = region->fast_out(i);
   606       if (phi->is_Phi() &&
   607           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
   608         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
   609         return phi->as_Phi();
   610       }
   611     }
   612   }
   613   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
   614     if (C->do_escape_analysis() == true && !C->failing()) {
   615       // Retry compilation without escape analysis.
   616       // If this is the first failure, the sentinel string will "stick"
   617       // to the Compile object, and the C2Compiler will see it and retry.
   618       C->record_failure(C2Compiler::retry_no_escape_analysis());
   619     }
   620     return NULL;
   621   }
   622   orig_phi_worklist.append_if_missing(orig_phi);
   623   const TypePtr *atype = C->get_adr_type(alias_idx);
   624   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
   625   C->copy_node_notes_to(result, orig_phi);
   626   igvn->set_type(result, result->bottom_type());
   627   record_for_optimizer(result);
   629   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
   630   assert(pn == NULL || pn == orig_phi, "wrong node");
   631   set_map(orig_phi->_idx, result);
   632   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
   634   new_created = true;
   635   return result;
   636 }
   638 //
   639 // Return a new version  of Memory Phi "orig_phi" with the inputs having the
   640 // specified alias index.
   641 //
   642 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
   644   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
   645   Compile *C = _compile;
   646   bool new_phi_created;
   647   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
   648   if (!new_phi_created) {
   649     return result;
   650   }
   652   GrowableArray<PhiNode *>  phi_list;
   653   GrowableArray<uint>  cur_input;
   655   PhiNode *phi = orig_phi;
   656   uint idx = 1;
   657   bool finished = false;
   658   while(!finished) {
   659     while (idx < phi->req()) {
   660       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
   661       if (mem != NULL && mem->is_Phi()) {
   662         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
   663         if (new_phi_created) {
   664           // found an phi for which we created a new split, push current one on worklist and begin
   665           // processing new one
   666           phi_list.push(phi);
   667           cur_input.push(idx);
   668           phi = mem->as_Phi();
   669           result = newphi;
   670           idx = 1;
   671           continue;
   672         } else {
   673           mem = newphi;
   674         }
   675       }
   676       if (C->failing()) {
   677         return NULL;
   678       }
   679       result->set_req(idx++, mem);
   680     }
   681 #ifdef ASSERT
   682     // verify that the new Phi has an input for each input of the original
   683     assert( phi->req() == result->req(), "must have same number of inputs.");
   684     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
   685 #endif
   686     // Check if all new phi's inputs have specified alias index.
   687     // Otherwise use old phi.
   688     for (uint i = 1; i < phi->req(); i++) {
   689       Node* in = result->in(i);
   690       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
   691     }
   692     // we have finished processing a Phi, see if there are any more to do
   693     finished = (phi_list.length() == 0 );
   694     if (!finished) {
   695       phi = phi_list.pop();
   696       idx = cur_input.pop();
   697       PhiNode *prev_result = get_map_phi(phi->_idx);
   698       prev_result->set_req(idx++, result);
   699       result = prev_result;
   700     }
   701   }
   702   return result;
   703 }
   706 //
   707 // The next methods are derived from methods in MemNode.
   708 //
   709 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *tinst) {
   710   Node *mem = mmem;
   711   // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally
   712   // means an array I have not precisely typed yet.  Do not do any
   713   // alias stuff with it any time soon.
   714   if( tinst->base() != Type::AnyPtr &&
   715       !(tinst->klass()->is_java_lang_Object() &&
   716         tinst->offset() == Type::OffsetBot) ) {
   717     mem = mmem->memory_at(alias_idx);
   718     // Update input if it is progress over what we have now
   719   }
   720   return mem;
   721 }
   723 //
   724 // Move memory users to their memory slices.
   725 //
   726 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
   727   Compile* C = _compile;
   729   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
   730   assert(tp != NULL, "ptr type");
   731   int alias_idx = C->get_alias_index(tp);
   732   int general_idx = C->get_general_index(alias_idx);
   734   // Move users first
   735   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
   736     Node* use = n->fast_out(i);
   737     if (use->is_MergeMem()) {
   738       MergeMemNode* mmem = use->as_MergeMem();
   739       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
   740       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
   741         continue; // Nothing to do
   742       }
   743       // Replace previous general reference to mem node.
   744       uint orig_uniq = C->unique();
   745       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   746       assert(orig_uniq == C->unique(), "no new nodes");
   747       mmem->set_memory_at(general_idx, m);
   748       --imax;
   749       --i;
   750     } else if (use->is_MemBar()) {
   751       assert(!use->is_Initialize(), "initializing stores should not be moved");
   752       if (use->req() > MemBarNode::Precedent &&
   753           use->in(MemBarNode::Precedent) == n) {
   754         // Don't move related membars.
   755         record_for_optimizer(use);
   756         continue;
   757       }
   758       tp = use->as_MemBar()->adr_type()->isa_ptr();
   759       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
   760           alias_idx == general_idx) {
   761         continue; // Nothing to do
   762       }
   763       // Move to general memory slice.
   764       uint orig_uniq = C->unique();
   765       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   766       assert(orig_uniq == C->unique(), "no new nodes");
   767       igvn->hash_delete(use);
   768       imax -= use->replace_edge(n, m);
   769       igvn->hash_insert(use);
   770       record_for_optimizer(use);
   771       --i;
   772 #ifdef ASSERT
   773     } else if (use->is_Mem()) {
   774       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
   775         // Don't move related cardmark.
   776         continue;
   777       }
   778       // Memory nodes should have new memory input.
   779       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
   780       assert(tp != NULL, "ptr type");
   781       int idx = C->get_alias_index(tp);
   782       assert(get_map(use->_idx) != NULL || idx == alias_idx,
   783              "Following memory nodes should have new memory input or be on the same memory slice");
   784     } else if (use->is_Phi()) {
   785       // Phi nodes should be split and moved already.
   786       tp = use->as_Phi()->adr_type()->isa_ptr();
   787       assert(tp != NULL, "ptr type");
   788       int idx = C->get_alias_index(tp);
   789       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
   790     } else {
   791       use->dump();
   792       assert(false, "should not be here");
   793 #endif
   794     }
   795   }
   796 }
   798 //
   799 // Search memory chain of "mem" to find a MemNode whose address
   800 // is the specified alias index.
   801 //
   802 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
   803   if (orig_mem == NULL)
   804     return orig_mem;
   805   Compile* C = phase->C;
   806   const TypeOopPtr *tinst = C->get_adr_type(alias_idx)->isa_oopptr();
   807   bool is_instance = (tinst != NULL) && tinst->is_known_instance();
   808   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   809   Node *prev = NULL;
   810   Node *result = orig_mem;
   811   while (prev != result) {
   812     prev = result;
   813     if (result == start_mem)
   814       break;  // hit one of our sentinels
   815     if (result->is_Mem()) {
   816       const Type *at = phase->type(result->in(MemNode::Address));
   817       if (at != Type::TOP) {
   818         assert (at->isa_ptr() != NULL, "pointer type required.");
   819         int idx = C->get_alias_index(at->is_ptr());
   820         if (idx == alias_idx)
   821           break;
   822       }
   823       result = result->in(MemNode::Memory);
   824     }
   825     if (!is_instance)
   826       continue;  // don't search further for non-instance types
   827     // skip over a call which does not affect this memory slice
   828     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
   829       Node *proj_in = result->in(0);
   830       if (proj_in->is_Allocate() && proj_in->_idx == (uint)tinst->instance_id()) {
   831         break;  // hit one of our sentinels
   832       } else if (proj_in->is_Call()) {
   833         CallNode *call = proj_in->as_Call();
   834         if (!call->may_modify(tinst, phase)) {
   835           result = call->in(TypeFunc::Memory);
   836         }
   837       } else if (proj_in->is_Initialize()) {
   838         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
   839         // Stop if this is the initialization for the object instance which
   840         // which contains this memory slice, otherwise skip over it.
   841         if (alloc == NULL || alloc->_idx != (uint)tinst->instance_id()) {
   842           result = proj_in->in(TypeFunc::Memory);
   843         }
   844       } else if (proj_in->is_MemBar()) {
   845         result = proj_in->in(TypeFunc::Memory);
   846       }
   847     } else if (result->is_MergeMem()) {
   848       MergeMemNode *mmem = result->as_MergeMem();
   849       result = step_through_mergemem(mmem, alias_idx, tinst);
   850       if (result == mmem->base_memory()) {
   851         // Didn't find instance memory, search through general slice recursively.
   852         result = mmem->memory_at(C->get_general_index(alias_idx));
   853         result = find_inst_mem(result, alias_idx, orig_phis, phase);
   854         if (C->failing()) {
   855           return NULL;
   856         }
   857         mmem->set_memory_at(alias_idx, result);
   858       }
   859     } else if (result->is_Phi() &&
   860                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
   861       Node *un = result->as_Phi()->unique_input(phase);
   862       if (un != NULL) {
   863         orig_phis.append_if_missing(result->as_Phi());
   864         result = un;
   865       } else {
   866         break;
   867       }
   868     } else if (result->is_ClearArray()) {
   869       if (!ClearArrayNode::step_through(&result, (uint)tinst->instance_id(), phase)) {
   870         // Can not bypass initialization of the instance
   871         // we are looking for.
   872         break;
   873       }
   874       // Otherwise skip it (the call updated 'result' value).
   875     } else if (result->Opcode() == Op_SCMemProj) {
   876       assert(result->in(0)->is_LoadStore(), "sanity");
   877       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
   878       if (at != Type::TOP) {
   879         assert (at->isa_ptr() != NULL, "pointer type required.");
   880         int idx = C->get_alias_index(at->is_ptr());
   881         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
   882         break;
   883       }
   884       result = result->in(0)->in(MemNode::Memory);
   885     }
   886   }
   887   if (result->is_Phi()) {
   888     PhiNode *mphi = result->as_Phi();
   889     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
   890     const TypePtr *t = mphi->adr_type();
   891     if (C->get_alias_index(t) != alias_idx) {
   892       // Create a new Phi with the specified alias index type.
   893       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
   894     } else if (!is_instance) {
   895       // Push all non-instance Phis on the orig_phis worklist to update inputs
   896       // during Phase 4 if needed.
   897       orig_phis.append_if_missing(mphi);
   898     }
   899   }
   900   // the result is either MemNode, PhiNode, InitializeNode.
   901   return result;
   902 }
   904 //
   905 //  Convert the types of unescaped object to instance types where possible,
   906 //  propagate the new type information through the graph, and update memory
   907 //  edges and MergeMem inputs to reflect the new type.
   908 //
   909 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
   910 //  The processing is done in 4 phases:
   911 //
   912 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
   913 //            types for the CheckCastPP for allocations where possible.
   914 //            Propagate the the new types through users as follows:
   915 //               casts and Phi:  push users on alloc_worklist
   916 //               AddP:  cast Base and Address inputs to the instance type
   917 //                      push any AddP users on alloc_worklist and push any memnode
   918 //                      users onto memnode_worklist.
   919 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
   920 //            search the Memory chain for a store with the appropriate type
   921 //            address type.  If a Phi is found, create a new version with
   922 //            the appropriate memory slices from each of the Phi inputs.
   923 //            For stores, process the users as follows:
   924 //               MemNode:  push on memnode_worklist
   925 //               MergeMem: push on mergemem_worklist
   926 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
   927 //            moving the first node encountered of each  instance type to the
   928 //            the input corresponding to its alias index.
   929 //            appropriate memory slice.
   930 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
   931 //
   932 // In the following example, the CheckCastPP nodes are the cast of allocation
   933 // results and the allocation of node 29 is unescaped and eligible to be an
   934 // instance type.
   935 //
   936 // We start with:
   937 //
   938 //     7 Parm #memory
   939 //    10  ConI  "12"
   940 //    19  CheckCastPP   "Foo"
   941 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   942 //    29  CheckCastPP   "Foo"
   943 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
   944 //
   945 //    40  StoreP  25   7  20   ... alias_index=4
   946 //    50  StoreP  35  40  30   ... alias_index=4
   947 //    60  StoreP  45  50  20   ... alias_index=4
   948 //    70  LoadP    _  60  30   ... alias_index=4
   949 //    80  Phi     75  50  60   Memory alias_index=4
   950 //    90  LoadP    _  80  30   ... alias_index=4
   951 //   100  LoadP    _  80  20   ... alias_index=4
   952 //
   953 //
   954 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
   955 // and creating a new alias index for node 30.  This gives:
   956 //
   957 //     7 Parm #memory
   958 //    10  ConI  "12"
   959 //    19  CheckCastPP   "Foo"
   960 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   961 //    29  CheckCastPP   "Foo"  iid=24
   962 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
   963 //
   964 //    40  StoreP  25   7  20   ... alias_index=4
   965 //    50  StoreP  35  40  30   ... alias_index=6
   966 //    60  StoreP  45  50  20   ... alias_index=4
   967 //    70  LoadP    _  60  30   ... alias_index=6
   968 //    80  Phi     75  50  60   Memory alias_index=4
   969 //    90  LoadP    _  80  30   ... alias_index=6
   970 //   100  LoadP    _  80  20   ... alias_index=4
   971 //
   972 // In phase 2, new memory inputs are computed for the loads and stores,
   973 // And a new version of the phi is created.  In phase 4, the inputs to
   974 // node 80 are updated and then the memory nodes are updated with the
   975 // values computed in phase 2.  This results in:
   976 //
   977 //     7 Parm #memory
   978 //    10  ConI  "12"
   979 //    19  CheckCastPP   "Foo"
   980 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   981 //    29  CheckCastPP   "Foo"  iid=24
   982 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
   983 //
   984 //    40  StoreP  25  7   20   ... alias_index=4
   985 //    50  StoreP  35  7   30   ... alias_index=6
   986 //    60  StoreP  45  40  20   ... alias_index=4
   987 //    70  LoadP    _  50  30   ... alias_index=6
   988 //    80  Phi     75  40  60   Memory alias_index=4
   989 //   120  Phi     75  50  50   Memory alias_index=6
   990 //    90  LoadP    _ 120  30   ... alias_index=6
   991 //   100  LoadP    _  80  20   ... alias_index=4
   992 //
   993 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
   994   GrowableArray<Node *>  memnode_worklist;
   995   GrowableArray<PhiNode *>  orig_phis;
   997   PhaseGVN  *igvn = _igvn;
   998   uint new_index_start = (uint) _compile->num_alias_types();
   999   Arena* arena = Thread::current()->resource_area();
  1000   VectorSet visited(arena);
  1001   VectorSet ptset(arena);
  1004   //  Phase 1:  Process possible allocations from alloc_worklist.
  1005   //  Create instance types for the CheckCastPP for allocations where possible.
  1006   //
  1007   // (Note: don't forget to change the order of the second AddP node on
  1008   //  the alloc_worklist if the order of the worklist processing is changed,
  1009   //  see the comment in find_second_addp().)
  1010   //
  1011   while (alloc_worklist.length() != 0) {
  1012     Node *n = alloc_worklist.pop();
  1013     uint ni = n->_idx;
  1014     const TypeOopPtr* tinst = NULL;
  1015     if (n->is_Call()) {
  1016       CallNode *alloc = n->as_Call();
  1017       // copy escape information to call node
  1018       PointsToNode* ptn = ptnode_adr(alloc->_idx);
  1019       PointsToNode::EscapeState es = escape_state(alloc);
  1020       // We have an allocation or call which returns a Java object,
  1021       // see if it is unescaped.
  1022       if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
  1023         continue;
  1025       // Find CheckCastPP for the allocate or for the return value of a call
  1026       n = alloc->result_cast();
  1027       if (n == NULL) {            // No uses except Initialize node
  1028         if (alloc->is_Allocate()) {
  1029           // Set the scalar_replaceable flag for allocation
  1030           // so it could be eliminated if it has no uses.
  1031           alloc->as_Allocate()->_is_scalar_replaceable = true;
  1033         continue;
  1035       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
  1036         assert(!alloc->is_Allocate(), "allocation should have unique type");
  1037         continue;
  1040       // The inline code for Object.clone() casts the allocation result to
  1041       // java.lang.Object and then to the actual type of the allocated
  1042       // object. Detect this case and use the second cast.
  1043       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
  1044       // the allocation result is cast to java.lang.Object and then
  1045       // to the actual Array type.
  1046       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
  1047           && (alloc->is_AllocateArray() ||
  1048               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
  1049         Node *cast2 = NULL;
  1050         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1051           Node *use = n->fast_out(i);
  1052           if (use->is_CheckCastPP()) {
  1053             cast2 = use;
  1054             break;
  1057         if (cast2 != NULL) {
  1058           n = cast2;
  1059         } else {
  1060           // Non-scalar replaceable if the allocation type is unknown statically
  1061           // (reflection allocation), the object can't be restored during
  1062           // deoptimization without precise type.
  1063           continue;
  1066       if (alloc->is_Allocate()) {
  1067         // Set the scalar_replaceable flag for allocation
  1068         // so it could be eliminated.
  1069         alloc->as_Allocate()->_is_scalar_replaceable = true;
  1071       set_escape_state(n->_idx, es);
  1072       // in order for an object to be scalar-replaceable, it must be:
  1073       //   - a direct allocation (not a call returning an object)
  1074       //   - non-escaping
  1075       //   - eligible to be a unique type
  1076       //   - not determined to be ineligible by escape analysis
  1077       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
  1078              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
  1079       set_map(alloc->_idx, n);
  1080       set_map(n->_idx, alloc);
  1081       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
  1082       if (t == NULL)
  1083         continue;  // not a TypeInstPtr
  1084       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
  1085       igvn->hash_delete(n);
  1086       igvn->set_type(n,  tinst);
  1087       n->raise_bottom_type(tinst);
  1088       igvn->hash_insert(n);
  1089       record_for_optimizer(n);
  1090       if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
  1091           (t->isa_instptr() || t->isa_aryptr())) {
  1093         // First, put on the worklist all Field edges from Connection Graph
  1094         // which is more accurate then putting immediate users from Ideal Graph.
  1095         for (uint e = 0; e < ptn->edge_count(); e++) {
  1096           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
  1097           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
  1098                  "only AddP nodes are Field edges in CG");
  1099           if (use->outcnt() > 0) { // Don't process dead nodes
  1100             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
  1101             if (addp2 != NULL) {
  1102               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1103               alloc_worklist.append_if_missing(addp2);
  1105             alloc_worklist.append_if_missing(use);
  1109         // An allocation may have an Initialize which has raw stores. Scan
  1110         // the users of the raw allocation result and push AddP users
  1111         // on alloc_worklist.
  1112         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
  1113         assert (raw_result != NULL, "must have an allocation result");
  1114         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
  1115           Node *use = raw_result->fast_out(i);
  1116           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
  1117             Node* addp2 = find_second_addp(use, raw_result);
  1118             if (addp2 != NULL) {
  1119               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1120               alloc_worklist.append_if_missing(addp2);
  1122             alloc_worklist.append_if_missing(use);
  1123           } else if (use->is_MemBar()) {
  1124             memnode_worklist.append_if_missing(use);
  1128     } else if (n->is_AddP()) {
  1129       ptset.Clear();
  1130       PointsTo(ptset, get_addp_base(n));
  1131       assert(ptset.Size() == 1, "AddP address is unique");
  1132       uint elem = ptset.getelem(); // Allocation node's index
  1133       if (elem == _phantom_object) {
  1134         assert(false, "escaped allocation");
  1135         continue; // Assume the value was set outside this method.
  1137       Node *base = get_map(elem);  // CheckCastPP node
  1138       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
  1139       tinst = igvn->type(base)->isa_oopptr();
  1140     } else if (n->is_Phi() ||
  1141                n->is_CheckCastPP() ||
  1142                n->is_EncodeP() ||
  1143                n->is_DecodeN() ||
  1144                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
  1145       if (visited.test_set(n->_idx)) {
  1146         assert(n->is_Phi(), "loops only through Phi's");
  1147         continue;  // already processed
  1149       ptset.Clear();
  1150       PointsTo(ptset, n);
  1151       if (ptset.Size() == 1) {
  1152         uint elem = ptset.getelem(); // Allocation node's index
  1153         if (elem == _phantom_object) {
  1154           assert(false, "escaped allocation");
  1155           continue; // Assume the value was set outside this method.
  1157         Node *val = get_map(elem);   // CheckCastPP node
  1158         TypeNode *tn = n->as_Type();
  1159         tinst = igvn->type(val)->isa_oopptr();
  1160         assert(tinst != NULL && tinst->is_known_instance() &&
  1161                (uint)tinst->instance_id() == elem , "instance type expected.");
  1163         const Type *tn_type = igvn->type(tn);
  1164         const TypeOopPtr *tn_t;
  1165         if (tn_type->isa_narrowoop()) {
  1166           tn_t = tn_type->make_ptr()->isa_oopptr();
  1167         } else {
  1168           tn_t = tn_type->isa_oopptr();
  1171         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
  1172           if (tn_type->isa_narrowoop()) {
  1173             tn_type = tinst->make_narrowoop();
  1174           } else {
  1175             tn_type = tinst;
  1177           igvn->hash_delete(tn);
  1178           igvn->set_type(tn, tn_type);
  1179           tn->set_type(tn_type);
  1180           igvn->hash_insert(tn);
  1181           record_for_optimizer(n);
  1182         } else {
  1183           assert(tn_type == TypePtr::NULL_PTR ||
  1184                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
  1185                  "unexpected type");
  1186           continue; // Skip dead path with different type
  1189     } else {
  1190       debug_only(n->dump();)
  1191       assert(false, "EA: unexpected node");
  1192       continue;
  1194     // push allocation's users on appropriate worklist
  1195     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1196       Node *use = n->fast_out(i);
  1197       if(use->is_Mem() && use->in(MemNode::Address) == n) {
  1198         // Load/store to instance's field
  1199         memnode_worklist.append_if_missing(use);
  1200       } else if (use->is_MemBar()) {
  1201         memnode_worklist.append_if_missing(use);
  1202       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
  1203         Node* addp2 = find_second_addp(use, n);
  1204         if (addp2 != NULL) {
  1205           alloc_worklist.append_if_missing(addp2);
  1207         alloc_worklist.append_if_missing(use);
  1208       } else if (use->is_Phi() ||
  1209                  use->is_CheckCastPP() ||
  1210                  use->is_EncodeP() ||
  1211                  use->is_DecodeN() ||
  1212                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
  1213         alloc_worklist.append_if_missing(use);
  1214 #ifdef ASSERT
  1215       } else if (use->is_Mem()) {
  1216         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
  1217       } else if (use->is_MergeMem()) {
  1218         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1219       } else if (use->is_SafePoint()) {
  1220         // Look for MergeMem nodes for calls which reference unique allocation
  1221         // (through CheckCastPP nodes) even for debug info.
  1222         Node* m = use->in(TypeFunc::Memory);
  1223         if (m->is_MergeMem()) {
  1224           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1226       } else {
  1227         uint op = use->Opcode();
  1228         if (!(op == Op_CmpP || op == Op_Conv2B ||
  1229               op == Op_CastP2X || op == Op_StoreCM ||
  1230               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
  1231               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1232           n->dump();
  1233           use->dump();
  1234           assert(false, "EA: missing allocation reference path");
  1236 #endif
  1241   // New alias types were created in split_AddP().
  1242   uint new_index_end = (uint) _compile->num_alias_types();
  1244   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
  1245   //            compute new values for Memory inputs  (the Memory inputs are not
  1246   //            actually updated until phase 4.)
  1247   if (memnode_worklist.length() == 0)
  1248     return;  // nothing to do
  1250   while (memnode_worklist.length() != 0) {
  1251     Node *n = memnode_worklist.pop();
  1252     if (visited.test_set(n->_idx))
  1253       continue;
  1254     if (n->is_Phi() || n->is_ClearArray()) {
  1255       // we don't need to do anything, but the users must be pushed
  1256     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
  1257       // we don't need to do anything, but the users must be pushed
  1258       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
  1259       if (n == NULL)
  1260         continue;
  1261     } else {
  1262       assert(n->is_Mem(), "memory node required.");
  1263       Node *addr = n->in(MemNode::Address);
  1264       const Type *addr_t = igvn->type(addr);
  1265       if (addr_t == Type::TOP)
  1266         continue;
  1267       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
  1268       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
  1269       assert ((uint)alias_idx < new_index_end, "wrong alias index");
  1270       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
  1271       if (_compile->failing()) {
  1272         return;
  1274       if (mem != n->in(MemNode::Memory)) {
  1275         // We delay the memory edge update since we need old one in
  1276         // MergeMem code below when instances memory slices are separated.
  1277         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
  1278         assert(pn == NULL || pn == n, "wrong node");
  1279         set_map(n->_idx, mem);
  1280         ptnode_adr(n->_idx)->_node = n;
  1282       if (n->is_Load()) {
  1283         continue;  // don't push users
  1284       } else if (n->is_LoadStore()) {
  1285         // get the memory projection
  1286         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1287           Node *use = n->fast_out(i);
  1288           if (use->Opcode() == Op_SCMemProj) {
  1289             n = use;
  1290             break;
  1293         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
  1296     // push user on appropriate worklist
  1297     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1298       Node *use = n->fast_out(i);
  1299       if (use->is_Phi() || use->is_ClearArray()) {
  1300         memnode_worklist.append_if_missing(use);
  1301       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
  1302         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
  1303           continue;
  1304         memnode_worklist.append_if_missing(use);
  1305       } else if (use->is_MemBar()) {
  1306         memnode_worklist.append_if_missing(use);
  1307 #ifdef ASSERT
  1308       } else if(use->is_Mem()) {
  1309         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
  1310       } else if (use->is_MergeMem()) {
  1311         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1312       } else {
  1313         uint op = use->Opcode();
  1314         if (!(op == Op_StoreCM ||
  1315               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
  1316                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
  1317               op == Op_AryEq || op == Op_StrComp ||
  1318               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1319           n->dump();
  1320           use->dump();
  1321           assert(false, "EA: missing memory path");
  1323 #endif
  1328   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
  1329   //            Walk each memory slice moving the first node encountered of each
  1330   //            instance type to the the input corresponding to its alias index.
  1331   uint length = _mergemem_worklist.length();
  1332   for( uint next = 0; next < length; ++next ) {
  1333     MergeMemNode* nmm = _mergemem_worklist.at(next);
  1334     assert(!visited.test_set(nmm->_idx), "should not be visited before");
  1335     // Note: we don't want to use MergeMemStream here because we only want to
  1336     // scan inputs which exist at the start, not ones we add during processing.
  1337     // Note 2: MergeMem may already contains instance memory slices added
  1338     // during find_inst_mem() call when memory nodes were processed above.
  1339     igvn->hash_delete(nmm);
  1340     uint nslices = nmm->req();
  1341     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
  1342       Node* mem = nmm->in(i);
  1343       Node* cur = NULL;
  1344       if (mem == NULL || mem->is_top())
  1345         continue;
  1346       // First, update mergemem by moving memory nodes to corresponding slices
  1347       // if their type became more precise since this mergemem was created.
  1348       while (mem->is_Mem()) {
  1349         const Type *at = igvn->type(mem->in(MemNode::Address));
  1350         if (at != Type::TOP) {
  1351           assert (at->isa_ptr() != NULL, "pointer type required.");
  1352           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
  1353           if (idx == i) {
  1354             if (cur == NULL)
  1355               cur = mem;
  1356           } else {
  1357             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
  1358               nmm->set_memory_at(idx, mem);
  1362         mem = mem->in(MemNode::Memory);
  1364       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
  1365       // Find any instance of the current type if we haven't encountered
  1366       // already a memory slice of the instance along the memory chain.
  1367       for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1368         if((uint)_compile->get_general_index(ni) == i) {
  1369           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
  1370           if (nmm->is_empty_memory(m)) {
  1371             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
  1372             if (_compile->failing()) {
  1373               return;
  1375             nmm->set_memory_at(ni, result);
  1380     // Find the rest of instances values
  1381     for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1382       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
  1383       Node* result = step_through_mergemem(nmm, ni, tinst);
  1384       if (result == nmm->base_memory()) {
  1385         // Didn't find instance memory, search through general slice recursively.
  1386         result = nmm->memory_at(_compile->get_general_index(ni));
  1387         result = find_inst_mem(result, ni, orig_phis, igvn);
  1388         if (_compile->failing()) {
  1389           return;
  1391         nmm->set_memory_at(ni, result);
  1394     igvn->hash_insert(nmm);
  1395     record_for_optimizer(nmm);
  1398   //  Phase 4:  Update the inputs of non-instance memory Phis and
  1399   //            the Memory input of memnodes
  1400   // First update the inputs of any non-instance Phi's from
  1401   // which we split out an instance Phi.  Note we don't have
  1402   // to recursively process Phi's encounted on the input memory
  1403   // chains as is done in split_memory_phi() since they  will
  1404   // also be processed here.
  1405   for (int j = 0; j < orig_phis.length(); j++) {
  1406     PhiNode *phi = orig_phis.at(j);
  1407     int alias_idx = _compile->get_alias_index(phi->adr_type());
  1408     igvn->hash_delete(phi);
  1409     for (uint i = 1; i < phi->req(); i++) {
  1410       Node *mem = phi->in(i);
  1411       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
  1412       if (_compile->failing()) {
  1413         return;
  1415       if (mem != new_mem) {
  1416         phi->set_req(i, new_mem);
  1419     igvn->hash_insert(phi);
  1420     record_for_optimizer(phi);
  1423   // Update the memory inputs of MemNodes with the value we computed
  1424   // in Phase 2 and move stores memory users to corresponding memory slices.
  1425 #ifdef ASSERT
  1426   visited.Clear();
  1427   Node_Stack old_mems(arena, _compile->unique() >> 2);
  1428 #endif
  1429   for (uint i = 0; i < nodes_size(); i++) {
  1430     Node *nmem = get_map(i);
  1431     if (nmem != NULL) {
  1432       Node *n = ptnode_adr(i)->_node;
  1433       assert(n != NULL, "sanity");
  1434       if (n->is_Mem()) {
  1435 #ifdef ASSERT
  1436         Node* old_mem = n->in(MemNode::Memory);
  1437         if (!visited.test_set(old_mem->_idx)) {
  1438           old_mems.push(old_mem, old_mem->outcnt());
  1440 #endif
  1441         assert(n->in(MemNode::Memory) != nmem, "sanity");
  1442         if (!n->is_Load()) {
  1443           // Move memory users of a store first.
  1444           move_inst_mem(n, orig_phis, igvn);
  1446         // Now update memory input
  1447         igvn->hash_delete(n);
  1448         n->set_req(MemNode::Memory, nmem);
  1449         igvn->hash_insert(n);
  1450         record_for_optimizer(n);
  1451       } else {
  1452         assert(n->is_Allocate() || n->is_CheckCastPP() ||
  1453                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
  1457 #ifdef ASSERT
  1458   // Verify that memory was split correctly
  1459   while (old_mems.is_nonempty()) {
  1460     Node* old_mem = old_mems.node();
  1461     uint  old_cnt = old_mems.index();
  1462     old_mems.pop();
  1463     assert(old_cnt = old_mem->outcnt(), "old mem could be lost");
  1465 #endif
  1468 bool ConnectionGraph::has_candidates(Compile *C) {
  1469   // EA brings benefits only when the code has allocations and/or locks which
  1470   // are represented by ideal Macro nodes.
  1471   int cnt = C->macro_count();
  1472   for( int i=0; i < cnt; i++ ) {
  1473     Node *n = C->macro_node(i);
  1474     if ( n->is_Allocate() )
  1475       return true;
  1476     if( n->is_Lock() ) {
  1477       Node* obj = n->as_Lock()->obj_node()->uncast();
  1478       if( !(obj->is_Parm() || obj->is_Con()) )
  1479         return true;
  1482   return false;
  1485 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  1486   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  1487   // to create space for them in ConnectionGraph::_nodes[].
  1488   Node* oop_null = igvn->zerocon(T_OBJECT);
  1489   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  1491   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  1492   // Perform escape analysis
  1493   if (congraph->compute_escape()) {
  1494     // There are non escaping objects.
  1495     C->set_congraph(congraph);
  1498   // Cleanup.
  1499   if (oop_null->outcnt() == 0)
  1500     igvn->hash_delete(oop_null);
  1501   if (noop_null->outcnt() == 0)
  1502     igvn->hash_delete(noop_null);
  1505 bool ConnectionGraph::compute_escape() {
  1506   Compile* C = _compile;
  1508   // 1. Populate Connection Graph (CG) with Ideal nodes.
  1510   Unique_Node_List worklist_init;
  1511   worklist_init.map(C->unique(), NULL);  // preallocate space
  1513   // Initialize worklist
  1514   if (C->root() != NULL) {
  1515     worklist_init.push(C->root());
  1518   GrowableArray<int> cg_worklist;
  1519   PhaseGVN* igvn = _igvn;
  1520   bool has_allocations = false;
  1522   // Push all useful nodes onto CG list and set their type.
  1523   for( uint next = 0; next < worklist_init.size(); ++next ) {
  1524     Node* n = worklist_init.at(next);
  1525     record_for_escape_analysis(n, igvn);
  1526     // Only allocations and java static calls results are checked
  1527     // for an escape status. See process_call_result() below.
  1528     if (n->is_Allocate() || n->is_CallStaticJava() &&
  1529         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
  1530       has_allocations = true;
  1532     if(n->is_AddP()) {
  1533       // Collect address nodes which directly reference an allocation.
  1534       // Use them during stage 3 below to build initial connection graph
  1535       // field edges. Other field edges could be added after StoreP/LoadP
  1536       // nodes are processed during stage 4 below.
  1537       Node* base = get_addp_base(n);
  1538       if(base->is_Proj() && base->in(0)->is_Allocate()) {
  1539         cg_worklist.append(n->_idx);
  1541     } else if (n->is_MergeMem()) {
  1542       // Collect all MergeMem nodes to add memory slices for
  1543       // scalar replaceable objects in split_unique_types().
  1544       _mergemem_worklist.append(n->as_MergeMem());
  1546     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1547       Node* m = n->fast_out(i);   // Get user
  1548       worklist_init.push(m);
  1552   if (!has_allocations) {
  1553     _collecting = false;
  1554     return false; // Nothing to do.
  1557   // 2. First pass to create simple CG edges (doesn't require to walk CG).
  1558   uint delayed_size = _delayed_worklist.size();
  1559   for( uint next = 0; next < delayed_size; ++next ) {
  1560     Node* n = _delayed_worklist.at(next);
  1561     build_connection_graph(n, igvn);
  1564   // 3. Pass to create fields edges (Allocate -F-> AddP).
  1565   uint cg_length = cg_worklist.length();
  1566   for( uint next = 0; next < cg_length; ++next ) {
  1567     int ni = cg_worklist.at(next);
  1568     build_connection_graph(ptnode_adr(ni)->_node, igvn);
  1571   cg_worklist.clear();
  1572   cg_worklist.append(_phantom_object);
  1574   // 4. Build Connection Graph which need
  1575   //    to walk the connection graph.
  1576   for (uint ni = 0; ni < nodes_size(); ni++) {
  1577     PointsToNode* ptn = ptnode_adr(ni);
  1578     Node *n = ptn->_node;
  1579     if (n != NULL) { // Call, AddP, LoadP, StoreP
  1580       build_connection_graph(n, igvn);
  1581       if (ptn->node_type() != PointsToNode::UnknownType)
  1582         cg_worklist.append(n->_idx); // Collect CG nodes
  1586   Arena* arena = Thread::current()->resource_area();
  1587   VectorSet ptset(arena);
  1588   GrowableArray<uint>  deferred_edges;
  1589   VectorSet visited(arena);
  1591   // 5. Remove deferred edges from the graph and adjust
  1592   //    escape state of nonescaping objects.
  1593   cg_length = cg_worklist.length();
  1594   for( uint next = 0; next < cg_length; ++next ) {
  1595     int ni = cg_worklist.at(next);
  1596     PointsToNode* ptn = ptnode_adr(ni);
  1597     PointsToNode::NodeType nt = ptn->node_type();
  1598     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
  1599       remove_deferred(ni, &deferred_edges, &visited);
  1600       Node *n = ptn->_node;
  1601       if (n->is_AddP()) {
  1602         // Search for objects which are not scalar replaceable
  1603         // and adjust their escape state.
  1604         verify_escape_state(ni, ptset, igvn);
  1609   // 6. Propagate escape states.
  1610   GrowableArray<int>  worklist;
  1611   bool has_non_escaping_obj = false;
  1613   // push all GlobalEscape nodes on the worklist
  1614   for( uint next = 0; next < cg_length; ++next ) {
  1615     int nk = cg_worklist.at(next);
  1616     if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
  1617       worklist.push(nk);
  1619   // mark all nodes reachable from GlobalEscape nodes
  1620   while(worklist.length() > 0) {
  1621     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1622     uint e_cnt = ptn->edge_count();
  1623     for (uint ei = 0; ei < e_cnt; ei++) {
  1624       uint npi = ptn->edge_target(ei);
  1625       PointsToNode *np = ptnode_adr(npi);
  1626       if (np->escape_state() < PointsToNode::GlobalEscape) {
  1627         np->set_escape_state(PointsToNode::GlobalEscape);
  1628         worklist.push(npi);
  1633   // push all ArgEscape nodes on the worklist
  1634   for( uint next = 0; next < cg_length; ++next ) {
  1635     int nk = cg_worklist.at(next);
  1636     if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
  1637       worklist.push(nk);
  1639   // mark all nodes reachable from ArgEscape nodes
  1640   while(worklist.length() > 0) {
  1641     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1642     if (ptn->node_type() == PointsToNode::JavaObject)
  1643       has_non_escaping_obj = true; // Non GlobalEscape
  1644     uint e_cnt = ptn->edge_count();
  1645     for (uint ei = 0; ei < e_cnt; ei++) {
  1646       uint npi = ptn->edge_target(ei);
  1647       PointsToNode *np = ptnode_adr(npi);
  1648       if (np->escape_state() < PointsToNode::ArgEscape) {
  1649         np->set_escape_state(PointsToNode::ArgEscape);
  1650         worklist.push(npi);
  1655   GrowableArray<Node*> alloc_worklist;
  1657   // push all NoEscape nodes on the worklist
  1658   for( uint next = 0; next < cg_length; ++next ) {
  1659     int nk = cg_worklist.at(next);
  1660     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
  1661       worklist.push(nk);
  1663   // mark all nodes reachable from NoEscape nodes
  1664   while(worklist.length() > 0) {
  1665     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1666     if (ptn->node_type() == PointsToNode::JavaObject)
  1667       has_non_escaping_obj = true; // Non GlobalEscape
  1668     Node* n = ptn->_node;
  1669     if (n->is_Allocate() && ptn->_scalar_replaceable ) {
  1670       // Push scalar replaceable allocations on alloc_worklist
  1671       // for processing in split_unique_types().
  1672       alloc_worklist.append(n);
  1674     uint e_cnt = ptn->edge_count();
  1675     for (uint ei = 0; ei < e_cnt; ei++) {
  1676       uint npi = ptn->edge_target(ei);
  1677       PointsToNode *np = ptnode_adr(npi);
  1678       if (np->escape_state() < PointsToNode::NoEscape) {
  1679         np->set_escape_state(PointsToNode::NoEscape);
  1680         worklist.push(npi);
  1685   _collecting = false;
  1686   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
  1688 #ifndef PRODUCT
  1689   if (PrintEscapeAnalysis) {
  1690     dump(); // Dump ConnectionGraph
  1692 #endif
  1694   bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
  1695   if ( has_scalar_replaceable_candidates &&
  1696        C->AliasLevel() >= 3 && EliminateAllocations ) {
  1698     // Now use the escape information to create unique types for
  1699     // scalar replaceable objects.
  1700     split_unique_types(alloc_worklist);
  1702     if (C->failing())  return false;
  1704     C->print_method("After Escape Analysis", 2);
  1706 #ifdef ASSERT
  1707   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
  1708     tty->print("=== No allocations eliminated for ");
  1709     C->method()->print_short_name();
  1710     if(!EliminateAllocations) {
  1711       tty->print(" since EliminateAllocations is off ===");
  1712     } else if(!has_scalar_replaceable_candidates) {
  1713       tty->print(" since there are no scalar replaceable candidates ===");
  1714     } else if(C->AliasLevel() < 3) {
  1715       tty->print(" since AliasLevel < 3 ===");
  1717     tty->cr();
  1718 #endif
  1720   return has_non_escaping_obj;
  1723 // Search for objects which are not scalar replaceable.
  1724 void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
  1725   PointsToNode* ptn = ptnode_adr(nidx);
  1726   Node* n = ptn->_node;
  1727   assert(n->is_AddP(), "Should be called for AddP nodes only");
  1728   // Search for objects which are not scalar replaceable.
  1729   // Mark their escape state as ArgEscape to propagate the state
  1730   // to referenced objects.
  1731   // Note: currently there are no difference in compiler optimizations
  1732   // for ArgEscape objects and NoEscape objects which are not
  1733   // scalar replaceable.
  1735   Compile* C = _compile;
  1737   int offset = ptn->offset();
  1738   Node* base = get_addp_base(n);
  1739   ptset.Clear();
  1740   PointsTo(ptset, base);
  1741   int ptset_size = ptset.Size();
  1743   // Check if a oop field's initializing value is recorded and add
  1744   // a corresponding NULL field's value if it is not recorded.
  1745   // Connection Graph does not record a default initialization by NULL
  1746   // captured by Initialize node.
  1747   //
  1748   // Note: it will disable scalar replacement in some cases:
  1749   //
  1750   //    Point p[] = new Point[1];
  1751   //    p[0] = new Point(); // Will be not scalar replaced
  1752   //
  1753   // but it will save us from incorrect optimizations in next cases:
  1754   //
  1755   //    Point p[] = new Point[1];
  1756   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
  1757   //
  1758   // Do a simple control flow analysis to distinguish above cases.
  1759   //
  1760   if (offset != Type::OffsetBot && ptset_size == 1) {
  1761     uint elem = ptset.getelem(); // Allocation node's index
  1762     // It does not matter if it is not Allocation node since
  1763     // only non-escaping allocations are scalar replaced.
  1764     if (ptnode_adr(elem)->_node->is_Allocate() &&
  1765         ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
  1766       AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
  1767       InitializeNode* ini = alloc->initialization();
  1769       // Check only oop fields.
  1770       const Type* adr_type = n->as_AddP()->bottom_type();
  1771       BasicType basic_field_type = T_INT;
  1772       if (adr_type->isa_instptr()) {
  1773         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
  1774         if (field != NULL) {
  1775           basic_field_type = field->layout_type();
  1776         } else {
  1777           // Ignore non field load (for example, klass load)
  1779       } else if (adr_type->isa_aryptr()) {
  1780         const Type* elemtype = adr_type->isa_aryptr()->elem();
  1781         basic_field_type = elemtype->array_element_basic_type();
  1782       } else {
  1783         // Raw pointers are used for initializing stores so skip it.
  1784         assert(adr_type->isa_rawptr() && base->is_Proj() &&
  1785                (base->in(0) == alloc),"unexpected pointer type");
  1787       if (basic_field_type == T_OBJECT ||
  1788           basic_field_type == T_NARROWOOP ||
  1789           basic_field_type == T_ARRAY) {
  1790         Node* value = NULL;
  1791         if (ini != NULL) {
  1792           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
  1793           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
  1794           if (store != NULL && store->is_Store()) {
  1795             value = store->in(MemNode::ValueIn);
  1796           } else if (ptn->edge_count() > 0) { // Are there oop stores?
  1797             // Check for a store which follows allocation without branches.
  1798             // For example, a volatile field store is not collected
  1799             // by Initialize node. TODO: it would be nice to use idom() here.
  1800             for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1801               store = n->fast_out(i);
  1802               if (store->is_Store() && store->in(0) != NULL) {
  1803                 Node* ctrl = store->in(0);
  1804                 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
  1805                         ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
  1806                         ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
  1807                    ctrl = ctrl->in(0);
  1809                 if (ctrl == ini || ctrl == alloc) {
  1810                   value = store->in(MemNode::ValueIn);
  1811                   break;
  1817         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
  1818           // A field's initializing value was not recorded. Add NULL.
  1819           uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
  1820           add_pointsto_edge(nidx, null_idx);
  1826   // An object is not scalar replaceable if the field which may point
  1827   // to it has unknown offset (unknown element of an array of objects).
  1828   //
  1829   if (offset == Type::OffsetBot) {
  1830     uint e_cnt = ptn->edge_count();
  1831     for (uint ei = 0; ei < e_cnt; ei++) {
  1832       uint npi = ptn->edge_target(ei);
  1833       set_escape_state(npi, PointsToNode::ArgEscape);
  1834       ptnode_adr(npi)->_scalar_replaceable = false;
  1838   // Currently an object is not scalar replaceable if a LoadStore node
  1839   // access its field since the field value is unknown after it.
  1840   //
  1841   bool has_LoadStore = false;
  1842   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1843     Node *use = n->fast_out(i);
  1844     if (use->is_LoadStore()) {
  1845       has_LoadStore = true;
  1846       break;
  1849   // An object is not scalar replaceable if the address points
  1850   // to unknown field (unknown element for arrays, offset is OffsetBot).
  1851   //
  1852   // Or the address may point to more then one object. This may produce
  1853   // the false positive result (set scalar_replaceable to false)
  1854   // since the flow-insensitive escape analysis can't separate
  1855   // the case when stores overwrite the field's value from the case
  1856   // when stores happened on different control branches.
  1857   //
  1858   if (ptset_size > 1 || ptset_size != 0 &&
  1859       (has_LoadStore || offset == Type::OffsetBot)) {
  1860     for( VectorSetI j(&ptset); j.test(); ++j ) {
  1861       set_escape_state(j.elem, PointsToNode::ArgEscape);
  1862       ptnode_adr(j.elem)->_scalar_replaceable = false;
  1867 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
  1869     switch (call->Opcode()) {
  1870 #ifdef ASSERT
  1871     case Op_Allocate:
  1872     case Op_AllocateArray:
  1873     case Op_Lock:
  1874     case Op_Unlock:
  1875       assert(false, "should be done already");
  1876       break;
  1877 #endif
  1878     case Op_CallLeaf:
  1879     case Op_CallLeafNoFP:
  1881       // Stub calls, objects do not escape but they are not scale replaceable.
  1882       // Adjust escape state for outgoing arguments.
  1883       const TypeTuple * d = call->tf()->domain();
  1884       VectorSet ptset(Thread::current()->resource_area());
  1885       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1886         const Type* at = d->field_at(i);
  1887         Node *arg = call->in(i)->uncast();
  1888         const Type *aat = phase->type(arg);
  1889         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
  1890             ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
  1892           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
  1893                  aat->isa_ptr() != NULL, "expecting an Ptr");
  1894 #ifdef ASSERT
  1895           if (!(call->Opcode() == Op_CallLeafNoFP &&
  1896                 call->as_CallLeaf()->_name != NULL &&
  1897                 (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
  1898                 call->as_CallLeaf()->_name != NULL &&
  1899                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
  1900                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
  1901           ) {
  1902             call->dump();
  1903             assert(false, "EA: unexpected CallLeaf");
  1905 #endif
  1906           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  1907           if (arg->is_AddP()) {
  1908             //
  1909             // The inline_native_clone() case when the arraycopy stub is called
  1910             // after the allocation before Initialize and CheckCastPP nodes.
  1911             //
  1912             // Set AddP's base (Allocate) as not scalar replaceable since
  1913             // pointer to the base (with offset) is passed as argument.
  1914             //
  1915             arg = get_addp_base(arg);
  1917           ptset.Clear();
  1918           PointsTo(ptset, arg);
  1919           for( VectorSetI j(&ptset); j.test(); ++j ) {
  1920             uint pt = j.elem;
  1921             set_escape_state(pt, PointsToNode::ArgEscape);
  1925       break;
  1928     case Op_CallStaticJava:
  1929     // For a static call, we know exactly what method is being called.
  1930     // Use bytecode estimator to record the call's escape affects
  1932       ciMethod *meth = call->as_CallJava()->method();
  1933       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
  1934       // fall-through if not a Java method or no analyzer information
  1935       if (call_analyzer != NULL) {
  1936         const TypeTuple * d = call->tf()->domain();
  1937         VectorSet ptset(Thread::current()->resource_area());
  1938         bool copy_dependencies = false;
  1939         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1940           const Type* at = d->field_at(i);
  1941           int k = i - TypeFunc::Parms;
  1942           Node *arg = call->in(i)->uncast();
  1944           if (at->isa_oopptr() != NULL &&
  1945               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
  1947             bool global_escapes = false;
  1948             bool fields_escapes = false;
  1949             if (!call_analyzer->is_arg_stack(k)) {
  1950               // The argument global escapes, mark everything it could point to
  1951               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  1952               global_escapes = true;
  1953             } else {
  1954               if (!call_analyzer->is_arg_local(k)) {
  1955                 // The argument itself doesn't escape, but any fields might
  1956                 fields_escapes = true;
  1958               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  1959               copy_dependencies = true;
  1962             ptset.Clear();
  1963             PointsTo(ptset, arg);
  1964             for( VectorSetI j(&ptset); j.test(); ++j ) {
  1965               uint pt = j.elem;
  1966               if (global_escapes) {
  1967                 //The argument global escapes, mark everything it could point to
  1968                 set_escape_state(pt, PointsToNode::GlobalEscape);
  1969               } else {
  1970                 if (fields_escapes) {
  1971                   // The argument itself doesn't escape, but any fields might
  1972                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  1974                 set_escape_state(pt, PointsToNode::ArgEscape);
  1979         if (copy_dependencies)
  1980           call_analyzer->copy_dependencies(_compile->dependencies());
  1981         break;
  1985     default:
  1986     // Fall-through here if not a Java method or no analyzer information
  1987     // or some other type of call, assume the worst case: all arguments
  1988     // globally escape.
  1990       // adjust escape state for  outgoing arguments
  1991       const TypeTuple * d = call->tf()->domain();
  1992       VectorSet ptset(Thread::current()->resource_area());
  1993       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1994         const Type* at = d->field_at(i);
  1995         if (at->isa_oopptr() != NULL) {
  1996           Node *arg = call->in(i)->uncast();
  1997           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  1998           ptset.Clear();
  1999           PointsTo(ptset, arg);
  2000           for( VectorSetI j(&ptset); j.test(); ++j ) {
  2001             uint pt = j.elem;
  2002             set_escape_state(pt, PointsToNode::GlobalEscape);
  2009 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
  2010   CallNode   *call = resproj->in(0)->as_Call();
  2011   uint    call_idx = call->_idx;
  2012   uint resproj_idx = resproj->_idx;
  2014   switch (call->Opcode()) {
  2015     case Op_Allocate:
  2017       Node *k = call->in(AllocateNode::KlassNode);
  2018       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2019       assert(kt != NULL, "TypeKlassPtr  required.");
  2020       ciKlass* cik = kt->klass();
  2022       PointsToNode::EscapeState es;
  2023       uint edge_to;
  2024       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
  2025          !cik->is_instance_klass() || // StressReflectiveCode
  2026           cik->as_instance_klass()->has_finalizer()) {
  2027         es = PointsToNode::GlobalEscape;
  2028         edge_to = _phantom_object; // Could not be worse
  2029       } else {
  2030         es = PointsToNode::NoEscape;
  2031         edge_to = call_idx;
  2033       set_escape_state(call_idx, es);
  2034       add_pointsto_edge(resproj_idx, edge_to);
  2035       _processed.set(resproj_idx);
  2036       break;
  2039     case Op_AllocateArray:
  2042       Node *k = call->in(AllocateNode::KlassNode);
  2043       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2044       assert(kt != NULL, "TypeKlassPtr  required.");
  2045       ciKlass* cik = kt->klass();
  2047       PointsToNode::EscapeState es;
  2048       uint edge_to;
  2049       if (!cik->is_array_klass()) { // StressReflectiveCode
  2050         es = PointsToNode::GlobalEscape;
  2051         edge_to = _phantom_object;
  2052       } else {
  2053         es = PointsToNode::NoEscape;
  2054         edge_to = call_idx;
  2055         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
  2056         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
  2057           // Not scalar replaceable if the length is not constant or too big.
  2058           ptnode_adr(call_idx)->_scalar_replaceable = false;
  2061       set_escape_state(call_idx, es);
  2062       add_pointsto_edge(resproj_idx, edge_to);
  2063       _processed.set(resproj_idx);
  2064       break;
  2067     case Op_CallStaticJava:
  2068     // For a static call, we know exactly what method is being called.
  2069     // Use bytecode estimator to record whether the call's return value escapes
  2071       bool done = true;
  2072       const TypeTuple *r = call->tf()->range();
  2073       const Type* ret_type = NULL;
  2075       if (r->cnt() > TypeFunc::Parms)
  2076         ret_type = r->field_at(TypeFunc::Parms);
  2078       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2079       //        _multianewarray functions return a TypeRawPtr.
  2080       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
  2081         _processed.set(resproj_idx);
  2082         break;  // doesn't return a pointer type
  2084       ciMethod *meth = call->as_CallJava()->method();
  2085       const TypeTuple * d = call->tf()->domain();
  2086       if (meth == NULL) {
  2087         // not a Java method, assume global escape
  2088         set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2089         add_pointsto_edge(resproj_idx, _phantom_object);
  2090       } else {
  2091         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
  2092         bool copy_dependencies = false;
  2094         if (call_analyzer->is_return_allocated()) {
  2095           // Returns a newly allocated unescaped object, simply
  2096           // update dependency information.
  2097           // Mark it as NoEscape so that objects referenced by
  2098           // it's fields will be marked as NoEscape at least.
  2099           set_escape_state(call_idx, PointsToNode::NoEscape);
  2100           add_pointsto_edge(resproj_idx, call_idx);
  2101           copy_dependencies = true;
  2102         } else if (call_analyzer->is_return_local()) {
  2103           // determine whether any arguments are returned
  2104           set_escape_state(call_idx, PointsToNode::NoEscape);
  2105           bool ret_arg = false;
  2106           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2107             const Type* at = d->field_at(i);
  2109             if (at->isa_oopptr() != NULL) {
  2110               Node *arg = call->in(i)->uncast();
  2112               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
  2113                 ret_arg = true;
  2114                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2115                 if (arg_esp->node_type() == PointsToNode::UnknownType)
  2116                   done = false;
  2117                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
  2118                   add_pointsto_edge(resproj_idx, arg->_idx);
  2119                 else
  2120                   add_deferred_edge(resproj_idx, arg->_idx);
  2121                 arg_esp->_hidden_alias = true;
  2125           if (done && !ret_arg) {
  2126             // Returns unknown object.
  2127             set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2128             add_pointsto_edge(resproj_idx, _phantom_object);
  2130           copy_dependencies = true;
  2131         } else {
  2132           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2133           add_pointsto_edge(resproj_idx, _phantom_object);
  2134           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2135             const Type* at = d->field_at(i);
  2136             if (at->isa_oopptr() != NULL) {
  2137               Node *arg = call->in(i)->uncast();
  2138               PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2139               arg_esp->_hidden_alias = true;
  2143         if (copy_dependencies)
  2144           call_analyzer->copy_dependencies(_compile->dependencies());
  2146       if (done)
  2147         _processed.set(resproj_idx);
  2148       break;
  2151     default:
  2152     // Some other type of call, assume the worst case that the
  2153     // returned value, if any, globally escapes.
  2155       const TypeTuple *r = call->tf()->range();
  2156       if (r->cnt() > TypeFunc::Parms) {
  2157         const Type* ret_type = r->field_at(TypeFunc::Parms);
  2159         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2160         //        _multianewarray functions return a TypeRawPtr.
  2161         if (ret_type->isa_ptr() != NULL) {
  2162           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2163           add_pointsto_edge(resproj_idx, _phantom_object);
  2166       _processed.set(resproj_idx);
  2171 // Populate Connection Graph with Ideal nodes and create simple
  2172 // connection graph edges (do not need to check the node_type of inputs
  2173 // or to call PointsTo() to walk the connection graph).
  2174 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
  2175   if (_processed.test(n->_idx))
  2176     return; // No need to redefine node's state.
  2178   if (n->is_Call()) {
  2179     // Arguments to allocation and locking don't escape.
  2180     if (n->is_Allocate()) {
  2181       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
  2182       record_for_optimizer(n);
  2183     } else if (n->is_Lock() || n->is_Unlock()) {
  2184       // Put Lock and Unlock nodes on IGVN worklist to process them during
  2185       // the first IGVN optimization when escape information is still available.
  2186       record_for_optimizer(n);
  2187       _processed.set(n->_idx);
  2188     } else {
  2189       // Don't mark as processed since call's arguments have to be processed.
  2190       PointsToNode::NodeType nt = PointsToNode::UnknownType;
  2191       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
  2193       // Check if a call returns an object.
  2194       const TypeTuple *r = n->as_Call()->tf()->range();
  2195       if (r->cnt() > TypeFunc::Parms &&
  2196           r->field_at(TypeFunc::Parms)->isa_ptr() &&
  2197           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
  2198         nt = PointsToNode::JavaObject;
  2199         if (!n->is_CallStaticJava()) {
  2200           // Since the called mathod is statically unknown assume
  2201           // the worst case that the returned value globally escapes.
  2202           es = PointsToNode::GlobalEscape;
  2205       add_node(n, nt, es, false);
  2207     return;
  2210   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
  2211   // ThreadLocal has RawPrt type.
  2212   switch (n->Opcode()) {
  2213     case Op_AddP:
  2215       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
  2216       break;
  2218     case Op_CastX2P:
  2219     { // "Unsafe" memory access.
  2220       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2221       break;
  2223     case Op_CastPP:
  2224     case Op_CheckCastPP:
  2225     case Op_EncodeP:
  2226     case Op_DecodeN:
  2228       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2229       int ti = n->in(1)->_idx;
  2230       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2231       if (nt == PointsToNode::UnknownType) {
  2232         _delayed_worklist.push(n); // Process it later.
  2233         break;
  2234       } else if (nt == PointsToNode::JavaObject) {
  2235         add_pointsto_edge(n->_idx, ti);
  2236       } else {
  2237         add_deferred_edge(n->_idx, ti);
  2239       _processed.set(n->_idx);
  2240       break;
  2242     case Op_ConP:
  2244       // assume all pointer constants globally escape except for null
  2245       PointsToNode::EscapeState es;
  2246       if (phase->type(n) == TypePtr::NULL_PTR)
  2247         es = PointsToNode::NoEscape;
  2248       else
  2249         es = PointsToNode::GlobalEscape;
  2251       add_node(n, PointsToNode::JavaObject, es, true);
  2252       break;
  2254     case Op_ConN:
  2256       // assume all narrow oop constants globally escape except for null
  2257       PointsToNode::EscapeState es;
  2258       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
  2259         es = PointsToNode::NoEscape;
  2260       else
  2261         es = PointsToNode::GlobalEscape;
  2263       add_node(n, PointsToNode::JavaObject, es, true);
  2264       break;
  2266     case Op_CreateEx:
  2268       // assume that all exception objects globally escape
  2269       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2270       break;
  2272     case Op_LoadKlass:
  2273     case Op_LoadNKlass:
  2275       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2276       break;
  2278     case Op_LoadP:
  2279     case Op_LoadN:
  2281       const Type *t = phase->type(n);
  2282       if (t->make_ptr() == NULL) {
  2283         _processed.set(n->_idx);
  2284         return;
  2286       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2287       break;
  2289     case Op_Parm:
  2291       _processed.set(n->_idx); // No need to redefine it state.
  2292       uint con = n->as_Proj()->_con;
  2293       if (con < TypeFunc::Parms)
  2294         return;
  2295       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
  2296       if (t->isa_ptr() == NULL)
  2297         return;
  2298       // We have to assume all input parameters globally escape
  2299       // (Note: passing 'false' since _processed is already set).
  2300       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
  2301       break;
  2303     case Op_Phi:
  2305       const Type *t = n->as_Phi()->type();
  2306       if (t->make_ptr() == NULL) {
  2307         // nothing to do if not an oop or narrow oop
  2308         _processed.set(n->_idx);
  2309         return;
  2311       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2312       uint i;
  2313       for (i = 1; i < n->req() ; i++) {
  2314         Node* in = n->in(i);
  2315         if (in == NULL)
  2316           continue;  // ignore NULL
  2317         in = in->uncast();
  2318         if (in->is_top() || in == n)
  2319           continue;  // ignore top or inputs which go back this node
  2320         int ti = in->_idx;
  2321         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2322         if (nt == PointsToNode::UnknownType) {
  2323           break;
  2324         } else if (nt == PointsToNode::JavaObject) {
  2325           add_pointsto_edge(n->_idx, ti);
  2326         } else {
  2327           add_deferred_edge(n->_idx, ti);
  2330       if (i >= n->req())
  2331         _processed.set(n->_idx);
  2332       else
  2333         _delayed_worklist.push(n);
  2334       break;
  2336     case Op_Proj:
  2338       // we are only interested in the oop result projection from a call
  2339       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2340         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2341         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2342         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2343           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2344           int ti = n->in(0)->_idx;
  2345           // The call may not be registered yet (since not all its inputs are registered)
  2346           // if this is the projection from backbranch edge of Phi.
  2347           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
  2348             process_call_result(n->as_Proj(), phase);
  2350           if (!_processed.test(n->_idx)) {
  2351             // The call's result may need to be processed later if the call
  2352             // returns it's argument and the argument is not processed yet.
  2353             _delayed_worklist.push(n);
  2355           break;
  2358       _processed.set(n->_idx);
  2359       break;
  2361     case Op_Return:
  2363       if( n->req() > TypeFunc::Parms &&
  2364           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2365         // Treat Return value as LocalVar with GlobalEscape escape state.
  2366         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
  2367         int ti = n->in(TypeFunc::Parms)->_idx;
  2368         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2369         if (nt == PointsToNode::UnknownType) {
  2370           _delayed_worklist.push(n); // Process it later.
  2371           break;
  2372         } else if (nt == PointsToNode::JavaObject) {
  2373           add_pointsto_edge(n->_idx, ti);
  2374         } else {
  2375           add_deferred_edge(n->_idx, ti);
  2378       _processed.set(n->_idx);
  2379       break;
  2381     case Op_StoreP:
  2382     case Op_StoreN:
  2384       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2385       adr_type = adr_type->make_ptr();
  2386       if (adr_type->isa_oopptr()) {
  2387         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2388       } else {
  2389         Node* adr = n->in(MemNode::Address);
  2390         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
  2391             adr->in(AddPNode::Address)->is_Proj() &&
  2392             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
  2393           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2394           // We are computing a raw address for a store captured
  2395           // by an Initialize compute an appropriate address type.
  2396           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
  2397           assert(offs != Type::OffsetBot, "offset must be a constant");
  2398         } else {
  2399           _processed.set(n->_idx);
  2400           return;
  2403       break;
  2405     case Op_StorePConditional:
  2406     case Op_CompareAndSwapP:
  2407     case Op_CompareAndSwapN:
  2409       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2410       adr_type = adr_type->make_ptr();
  2411       if (adr_type->isa_oopptr()) {
  2412         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2413       } else {
  2414         _processed.set(n->_idx);
  2415         return;
  2417       break;
  2419     case Op_AryEq:
  2420     case Op_StrComp:
  2421     case Op_StrEquals:
  2422     case Op_StrIndexOf:
  2424       // char[] arrays passed to string intrinsics are not scalar replaceable.
  2425       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2426       break;
  2428     case Op_ThreadLocal:
  2430       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
  2431       break;
  2433     default:
  2435       // nothing to do
  2437   return;
  2440 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
  2441   uint n_idx = n->_idx;
  2442   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
  2444   // Don't set processed bit for AddP, LoadP, StoreP since
  2445   // they may need more then one pass to process.
  2446   if (_processed.test(n_idx))
  2447     return; // No need to redefine node's state.
  2449   if (n->is_Call()) {
  2450     CallNode *call = n->as_Call();
  2451     process_call_arguments(call, phase);
  2452     _processed.set(n_idx);
  2453     return;
  2456   switch (n->Opcode()) {
  2457     case Op_AddP:
  2459       Node *base = get_addp_base(n);
  2460       // Create a field edge to this node from everything base could point to.
  2461       VectorSet ptset(Thread::current()->resource_area());
  2462       PointsTo(ptset, base);
  2463       for( VectorSetI i(&ptset); i.test(); ++i ) {
  2464         uint pt = i.elem;
  2465         add_field_edge(pt, n_idx, address_offset(n, phase));
  2467       break;
  2469     case Op_CastX2P:
  2471       assert(false, "Op_CastX2P");
  2472       break;
  2474     case Op_CastPP:
  2475     case Op_CheckCastPP:
  2476     case Op_EncodeP:
  2477     case Op_DecodeN:
  2479       int ti = n->in(1)->_idx;
  2480       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
  2481       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2482         add_pointsto_edge(n_idx, ti);
  2483       } else {
  2484         add_deferred_edge(n_idx, ti);
  2486       _processed.set(n_idx);
  2487       break;
  2489     case Op_ConP:
  2491       assert(false, "Op_ConP");
  2492       break;
  2494     case Op_ConN:
  2496       assert(false, "Op_ConN");
  2497       break;
  2499     case Op_CreateEx:
  2501       assert(false, "Op_CreateEx");
  2502       break;
  2504     case Op_LoadKlass:
  2505     case Op_LoadNKlass:
  2507       assert(false, "Op_LoadKlass");
  2508       break;
  2510     case Op_LoadP:
  2511     case Op_LoadN:
  2513       const Type *t = phase->type(n);
  2514 #ifdef ASSERT
  2515       if (t->make_ptr() == NULL)
  2516         assert(false, "Op_LoadP");
  2517 #endif
  2519       Node* adr = n->in(MemNode::Address)->uncast();
  2520       Node* adr_base;
  2521       if (adr->is_AddP()) {
  2522         adr_base = get_addp_base(adr);
  2523       } else {
  2524         adr_base = adr;
  2527       // For everything "adr_base" could point to, create a deferred edge from
  2528       // this node to each field with the same offset.
  2529       VectorSet ptset(Thread::current()->resource_area());
  2530       PointsTo(ptset, adr_base);
  2531       int offset = address_offset(adr, phase);
  2532       for( VectorSetI i(&ptset); i.test(); ++i ) {
  2533         uint pt = i.elem;
  2534         add_deferred_edge_to_fields(n_idx, pt, offset);
  2536       break;
  2538     case Op_Parm:
  2540       assert(false, "Op_Parm");
  2541       break;
  2543     case Op_Phi:
  2545 #ifdef ASSERT
  2546       const Type *t = n->as_Phi()->type();
  2547       if (t->make_ptr() == NULL)
  2548         assert(false, "Op_Phi");
  2549 #endif
  2550       for (uint i = 1; i < n->req() ; i++) {
  2551         Node* in = n->in(i);
  2552         if (in == NULL)
  2553           continue;  // ignore NULL
  2554         in = in->uncast();
  2555         if (in->is_top() || in == n)
  2556           continue;  // ignore top or inputs which go back this node
  2557         int ti = in->_idx;
  2558         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2559         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
  2560         if (nt == PointsToNode::JavaObject) {
  2561           add_pointsto_edge(n_idx, ti);
  2562         } else {
  2563           add_deferred_edge(n_idx, ti);
  2566       _processed.set(n_idx);
  2567       break;
  2569     case Op_Proj:
  2571       // we are only interested in the oop result projection from a call
  2572       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2573         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
  2574                "all nodes should be registered");
  2575         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2576         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2577         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2578           process_call_result(n->as_Proj(), phase);
  2579           assert(_processed.test(n_idx), "all call results should be processed");
  2580           break;
  2583       assert(false, "Op_Proj");
  2584       break;
  2586     case Op_Return:
  2588 #ifdef ASSERT
  2589       if( n->req() <= TypeFunc::Parms ||
  2590           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2591         assert(false, "Op_Return");
  2593 #endif
  2594       int ti = n->in(TypeFunc::Parms)->_idx;
  2595       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
  2596       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2597         add_pointsto_edge(n_idx, ti);
  2598       } else {
  2599         add_deferred_edge(n_idx, ti);
  2601       _processed.set(n_idx);
  2602       break;
  2604     case Op_StoreP:
  2605     case Op_StoreN:
  2606     case Op_StorePConditional:
  2607     case Op_CompareAndSwapP:
  2608     case Op_CompareAndSwapN:
  2610       Node *adr = n->in(MemNode::Address);
  2611       const Type *adr_type = phase->type(adr)->make_ptr();
  2612 #ifdef ASSERT
  2613       if (!adr_type->isa_oopptr())
  2614         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
  2615 #endif
  2617       assert(adr->is_AddP(), "expecting an AddP");
  2618       Node *adr_base = get_addp_base(adr);
  2619       Node *val = n->in(MemNode::ValueIn)->uncast();
  2620       // For everything "adr_base" could point to, create a deferred edge
  2621       // to "val" from each field with the same offset.
  2622       VectorSet ptset(Thread::current()->resource_area());
  2623       PointsTo(ptset, adr_base);
  2624       for( VectorSetI i(&ptset); i.test(); ++i ) {
  2625         uint pt = i.elem;
  2626         add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
  2628       break;
  2630     case Op_AryEq:
  2631     case Op_StrComp:
  2632     case Op_StrEquals:
  2633     case Op_StrIndexOf:
  2635       // char[] arrays passed to string intrinsic do not escape but
  2636       // they are not scalar replaceable. Adjust escape state for them.
  2637       // Start from in(2) edge since in(1) is memory edge.
  2638       for (uint i = 2; i < n->req(); i++) {
  2639         Node* adr = n->in(i)->uncast();
  2640         const Type *at = phase->type(adr);
  2641         if (!adr->is_top() && at->isa_ptr()) {
  2642           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
  2643                  at->isa_ptr() != NULL, "expecting an Ptr");
  2644           if (adr->is_AddP()) {
  2645             adr = get_addp_base(adr);
  2647           // Mark as ArgEscape everything "adr" could point to.
  2648           set_escape_state(adr->_idx, PointsToNode::ArgEscape);
  2651       _processed.set(n_idx);
  2652       break;
  2654     case Op_ThreadLocal:
  2656       assert(false, "Op_ThreadLocal");
  2657       break;
  2659     default:
  2660       // This method should be called only for EA specific nodes.
  2661       ShouldNotReachHere();
  2665 #ifndef PRODUCT
  2666 void ConnectionGraph::dump() {
  2667   bool first = true;
  2669   uint size = nodes_size();
  2670   for (uint ni = 0; ni < size; ni++) {
  2671     PointsToNode *ptn = ptnode_adr(ni);
  2672     PointsToNode::NodeType ptn_type = ptn->node_type();
  2674     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
  2675       continue;
  2676     PointsToNode::EscapeState es = escape_state(ptn->_node);
  2677     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
  2678       if (first) {
  2679         tty->cr();
  2680         tty->print("======== Connection graph for ");
  2681         _compile->method()->print_short_name();
  2682         tty->cr();
  2683         first = false;
  2685       tty->print("%6d ", ni);
  2686       ptn->dump();
  2687       // Print all locals which reference this allocation
  2688       for (uint li = ni; li < size; li++) {
  2689         PointsToNode *ptn_loc = ptnode_adr(li);
  2690         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
  2691         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
  2692              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
  2693           ptnode_adr(li)->dump(false);
  2696       if (Verbose) {
  2697         // Print all fields which reference this allocation
  2698         for (uint i = 0; i < ptn->edge_count(); i++) {
  2699           uint ei = ptn->edge_target(i);
  2700           ptnode_adr(ei)->dump(false);
  2703       tty->cr();
  2707 #endif

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