src/share/vm/opto/escape.cpp

Sat, 06 Nov 2010 20:35:36 -0700

author
kvn
date
Sat, 06 Nov 2010 20:35:36 -0700
changeset 2276
e4fcbeb5a698
parent 2170
5867d89c129b
child 2314
f95d63e2154a
permissions
-rw-r--r--

6991188: C2 Crashes while compiling method
Summary: Do several iterations to build EA Connection Graph.
Reviewed-by: never, twisti, ysr

     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   _progress(false),
    89   _compile(C),
    90   _igvn(igvn),
    91   _node_map(C->comp_arena()) {
    93   _phantom_object = C->top()->_idx,
    94   add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
    96   // Add ConP(#NULL) and ConN(#NULL) nodes.
    97   Node* oop_null = igvn->zerocon(T_OBJECT);
    98   _oop_null = oop_null->_idx;
    99   assert(_oop_null < C->unique(), "should be created already");
   100   add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   102   if (UseCompressedOops) {
   103     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   104     _noop_null = noop_null->_idx;
   105     assert(_noop_null < C->unique(), "should be created already");
   106     add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   107   }
   108 }
   110 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
   111   PointsToNode *f = ptnode_adr(from_i);
   112   PointsToNode *t = ptnode_adr(to_i);
   114   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   115   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
   116   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
   117   add_edge(f, to_i, PointsToNode::PointsToEdge);
   118 }
   120 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
   121   PointsToNode *f = ptnode_adr(from_i);
   122   PointsToNode *t = ptnode_adr(to_i);
   124   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   125   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
   126   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
   127   // don't add a self-referential edge, this can occur during removal of
   128   // deferred edges
   129   if (from_i != to_i)
   130     add_edge(f, to_i, PointsToNode::DeferredEdge);
   131 }
   133 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
   134   const Type *adr_type = phase->type(adr);
   135   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
   136       adr->in(AddPNode::Address)->is_Proj() &&
   137       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
   138     // We are computing a raw address for a store captured by an Initialize
   139     // compute an appropriate address type. AddP cases #3 and #5 (see below).
   140     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
   141     assert(offs != Type::OffsetBot ||
   142            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
   143            "offset must be a constant or it is initialization of array");
   144     return offs;
   145   }
   146   const TypePtr *t_ptr = adr_type->isa_ptr();
   147   assert(t_ptr != NULL, "must be a pointer type");
   148   return t_ptr->offset();
   149 }
   151 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
   152   PointsToNode *f = ptnode_adr(from_i);
   153   PointsToNode *t = ptnode_adr(to_i);
   155   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   156   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
   157   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
   158   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
   159   t->set_offset(offset);
   161   add_edge(f, to_i, PointsToNode::FieldEdge);
   162 }
   164 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
   165   PointsToNode *npt = ptnode_adr(ni);
   166   PointsToNode::EscapeState old_es = npt->escape_state();
   167   if (es > old_es)
   168     npt->set_escape_state(es);
   169 }
   171 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
   172                                PointsToNode::EscapeState es, bool done) {
   173   PointsToNode* ptadr = ptnode_adr(n->_idx);
   174   ptadr->_node = n;
   175   ptadr->set_node_type(nt);
   177   // inline set_escape_state(idx, es);
   178   PointsToNode::EscapeState old_es = ptadr->escape_state();
   179   if (es > old_es)
   180     ptadr->set_escape_state(es);
   182   if (done)
   183     _processed.set(n->_idx);
   184 }
   186 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
   187   uint idx = n->_idx;
   188   PointsToNode::EscapeState es;
   190   // If we are still collecting or there were no non-escaping allocations
   191   // we don't know the answer yet
   192   if (_collecting)
   193     return PointsToNode::UnknownEscape;
   195   // if the node was created after the escape computation, return
   196   // UnknownEscape
   197   if (idx >= nodes_size())
   198     return PointsToNode::UnknownEscape;
   200   es = ptnode_adr(idx)->escape_state();
   202   // if we have already computed a value, return it
   203   if (es != PointsToNode::UnknownEscape &&
   204       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
   205     return es;
   207   // PointsTo() calls n->uncast() which can return a new ideal node.
   208   if (n->uncast()->_idx >= nodes_size())
   209     return PointsToNode::UnknownEscape;
   211   PointsToNode::EscapeState orig_es = es;
   213   // compute max escape state of anything this node could point to
   214   VectorSet ptset(Thread::current()->resource_area());
   215   PointsTo(ptset, n);
   216   for(VectorSetI i(&ptset); i.test() && es != PointsToNode::GlobalEscape; ++i) {
   217     uint pt = i.elem;
   218     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
   219     if (pes > es)
   220       es = pes;
   221   }
   222   if (orig_es != es) {
   223     // cache the computed escape state
   224     assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
   225     ptnode_adr(idx)->set_escape_state(es);
   226   } // orig_es could be PointsToNode::UnknownEscape
   227   return es;
   228 }
   230 void ConnectionGraph::PointsTo(VectorSet &ptset, Node * n) {
   231   VectorSet visited(Thread::current()->resource_area());
   232   GrowableArray<uint>  worklist;
   234 #ifdef ASSERT
   235   Node *orig_n = n;
   236 #endif
   238   n = n->uncast();
   239   PointsToNode* npt = ptnode_adr(n->_idx);
   241   // If we have a JavaObject, return just that object
   242   if (npt->node_type() == PointsToNode::JavaObject) {
   243     ptset.set(n->_idx);
   244     return;
   245   }
   246 #ifdef ASSERT
   247   if (npt->_node == NULL) {
   248     if (orig_n != n)
   249       orig_n->dump();
   250     n->dump();
   251     assert(npt->_node != NULL, "unregistered node");
   252   }
   253 #endif
   254   worklist.push(n->_idx);
   255   while(worklist.length() > 0) {
   256     int ni = worklist.pop();
   257     if (visited.test_set(ni))
   258       continue;
   260     PointsToNode* pn = ptnode_adr(ni);
   261     // ensure that all inputs of a Phi have been processed
   262     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
   264     int edges_processed = 0;
   265     uint e_cnt = pn->edge_count();
   266     for (uint e = 0; e < e_cnt; e++) {
   267       uint etgt = pn->edge_target(e);
   268       PointsToNode::EdgeType et = pn->edge_type(e);
   269       if (et == PointsToNode::PointsToEdge) {
   270         ptset.set(etgt);
   271         edges_processed++;
   272       } else if (et == PointsToNode::DeferredEdge) {
   273         worklist.push(etgt);
   274         edges_processed++;
   275       } else {
   276         assert(false,"neither PointsToEdge or DeferredEdge");
   277       }
   278     }
   279     if (edges_processed == 0) {
   280       // no deferred or pointsto edges found.  Assume the value was set
   281       // outside this method.  Add the phantom object to the pointsto set.
   282       ptset.set(_phantom_object);
   283     }
   284   }
   285 }
   287 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
   288   // This method is most expensive during ConnectionGraph construction.
   289   // Reuse vectorSet and an additional growable array for deferred edges.
   290   deferred_edges->clear();
   291   visited->Clear();
   293   visited->set(ni);
   294   PointsToNode *ptn = ptnode_adr(ni);
   296   // Mark current edges as visited and move deferred edges to separate array.
   297   for (uint i = 0; i < ptn->edge_count(); ) {
   298     uint t = ptn->edge_target(i);
   299 #ifdef ASSERT
   300     assert(!visited->test_set(t), "expecting no duplications");
   301 #else
   302     visited->set(t);
   303 #endif
   304     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
   305       ptn->remove_edge(t, PointsToNode::DeferredEdge);
   306       deferred_edges->append(t);
   307     } else {
   308       i++;
   309     }
   310   }
   311   for (int next = 0; next < deferred_edges->length(); ++next) {
   312     uint t = deferred_edges->at(next);
   313     PointsToNode *ptt = ptnode_adr(t);
   314     uint e_cnt = ptt->edge_count();
   315     for (uint e = 0; e < e_cnt; e++) {
   316       uint etgt = ptt->edge_target(e);
   317       if (visited->test_set(etgt))
   318         continue;
   320       PointsToNode::EdgeType et = ptt->edge_type(e);
   321       if (et == PointsToNode::PointsToEdge) {
   322         add_pointsto_edge(ni, etgt);
   323         if(etgt == _phantom_object) {
   324           // Special case - field set outside (globally escaping).
   325           ptn->set_escape_state(PointsToNode::GlobalEscape);
   326         }
   327       } else if (et == PointsToNode::DeferredEdge) {
   328         deferred_edges->append(etgt);
   329       } else {
   330         assert(false,"invalid connection graph");
   331       }
   332     }
   333   }
   334 }
   337 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
   338 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
   339 //  a pointsto edge is added if it is a JavaObject
   341 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
   342   PointsToNode* an = ptnode_adr(adr_i);
   343   PointsToNode* to = ptnode_adr(to_i);
   344   bool deferred = (to->node_type() == PointsToNode::LocalVar);
   346   for (uint fe = 0; fe < an->edge_count(); fe++) {
   347     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   348     int fi = an->edge_target(fe);
   349     PointsToNode* pf = ptnode_adr(fi);
   350     int po = pf->offset();
   351     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   352       if (deferred)
   353         add_deferred_edge(fi, to_i);
   354       else
   355         add_pointsto_edge(fi, to_i);
   356     }
   357   }
   358 }
   360 // Add a deferred  edge from node given by "from_i" to any field of adr_i
   361 // whose offset matches "offset".
   362 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
   363   PointsToNode* an = ptnode_adr(adr_i);
   364   for (uint fe = 0; fe < an->edge_count(); fe++) {
   365     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   366     int fi = an->edge_target(fe);
   367     PointsToNode* pf = ptnode_adr(fi);
   368     int po = pf->offset();
   369     if (pf->edge_count() == 0) {
   370       // we have not seen any stores to this field, assume it was set outside this method
   371       add_pointsto_edge(fi, _phantom_object);
   372     }
   373     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   374       add_deferred_edge(from_i, fi);
   375     }
   376   }
   377 }
   379 // Helper functions
   381 static Node* get_addp_base(Node *addp) {
   382   assert(addp->is_AddP(), "must be AddP");
   383   //
   384   // AddP cases for Base and Address inputs:
   385   // case #1. Direct object's field reference:
   386   //     Allocate
   387   //       |
   388   //     Proj #5 ( oop result )
   389   //       |
   390   //     CheckCastPP (cast to instance type)
   391   //      | |
   392   //     AddP  ( base == address )
   393   //
   394   // case #2. Indirect object's field reference:
   395   //      Phi
   396   //       |
   397   //     CastPP (cast to instance type)
   398   //      | |
   399   //     AddP  ( base == address )
   400   //
   401   // case #3. Raw object's field reference for Initialize node:
   402   //      Allocate
   403   //        |
   404   //      Proj #5 ( oop result )
   405   //  top   |
   406   //     \  |
   407   //     AddP  ( base == top )
   408   //
   409   // case #4. Array's element reference:
   410   //   {CheckCastPP | CastPP}
   411   //     |  | |
   412   //     |  AddP ( array's element offset )
   413   //     |  |
   414   //     AddP ( array's offset )
   415   //
   416   // case #5. Raw object's field reference for arraycopy stub call:
   417   //          The inline_native_clone() case when the arraycopy stub is called
   418   //          after the allocation before Initialize and CheckCastPP nodes.
   419   //      Allocate
   420   //        |
   421   //      Proj #5 ( oop result )
   422   //       | |
   423   //       AddP  ( base == address )
   424   //
   425   // case #6. Constant Pool, ThreadLocal, CastX2P or
   426   //          Raw object's field reference:
   427   //      {ConP, ThreadLocal, CastX2P, raw Load}
   428   //  top   |
   429   //     \  |
   430   //     AddP  ( base == top )
   431   //
   432   // case #7. Klass's field reference.
   433   //      LoadKlass
   434   //       | |
   435   //       AddP  ( base == address )
   436   //
   437   // case #8. narrow Klass's field reference.
   438   //      LoadNKlass
   439   //       |
   440   //      DecodeN
   441   //       | |
   442   //       AddP  ( base == address )
   443   //
   444   Node *base = addp->in(AddPNode::Base)->uncast();
   445   if (base->is_top()) { // The AddP case #3 and #6.
   446     base = addp->in(AddPNode::Address)->uncast();
   447     while (base->is_AddP()) {
   448       // Case #6 (unsafe access) may have several chained AddP nodes.
   449       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
   450       base = base->in(AddPNode::Address)->uncast();
   451     }
   452     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
   453            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
   454            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
   455            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
   456   }
   457   return base;
   458 }
   460 static Node* find_second_addp(Node* addp, Node* n) {
   461   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
   463   Node* addp2 = addp->raw_out(0);
   464   if (addp->outcnt() == 1 && addp2->is_AddP() &&
   465       addp2->in(AddPNode::Base) == n &&
   466       addp2->in(AddPNode::Address) == addp) {
   468     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
   469     //
   470     // Find array's offset to push it on worklist first and
   471     // as result process an array's element offset first (pushed second)
   472     // to avoid CastPP for the array's offset.
   473     // Otherwise the inserted CastPP (LocalVar) will point to what
   474     // the AddP (Field) points to. Which would be wrong since
   475     // the algorithm expects the CastPP has the same point as
   476     // as AddP's base CheckCastPP (LocalVar).
   477     //
   478     //    ArrayAllocation
   479     //     |
   480     //    CheckCastPP
   481     //     |
   482     //    memProj (from ArrayAllocation CheckCastPP)
   483     //     |  ||
   484     //     |  ||   Int (element index)
   485     //     |  ||    |   ConI (log(element size))
   486     //     |  ||    |   /
   487     //     |  ||   LShift
   488     //     |  ||  /
   489     //     |  AddP (array's element offset)
   490     //     |  |
   491     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
   492     //     | / /
   493     //     AddP (array's offset)
   494     //      |
   495     //     Load/Store (memory operation on array's element)
   496     //
   497     return addp2;
   498   }
   499   return NULL;
   500 }
   502 //
   503 // Adjust the type and inputs of an AddP which computes the
   504 // address of a field of an instance
   505 //
   506 bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
   507   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
   508   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
   509   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
   510   if (t == NULL) {
   511     // We are computing a raw address for a store captured by an Initialize
   512     // compute an appropriate address type (cases #3 and #5).
   513     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
   514     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
   515     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
   516     assert(offs != Type::OffsetBot, "offset must be a constant");
   517     t = base_t->add_offset(offs)->is_oopptr();
   518   }
   519   int inst_id =  base_t->instance_id();
   520   assert(!t->is_known_instance() || t->instance_id() == inst_id,
   521                              "old type must be non-instance or match new type");
   523   // The type 't' could be subclass of 'base_t'.
   524   // As result t->offset() could be large then base_t's size and it will
   525   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
   526   // constructor verifies correctness of the offset.
   527   //
   528   // It could happened on subclass's branch (from the type profiling
   529   // inlining) which was not eliminated during parsing since the exactness
   530   // of the allocation type was not propagated to the subclass type check.
   531   //
   532   // Or the type 't' could be not related to 'base_t' at all.
   533   // It could happened when CHA type is different from MDO type on a dead path
   534   // (for example, from instanceof check) which is not collapsed during parsing.
   535   //
   536   // Do nothing for such AddP node and don't process its users since
   537   // this code branch will go away.
   538   //
   539   if (!t->is_known_instance() &&
   540       !base_t->klass()->is_subtype_of(t->klass())) {
   541      return false; // bail out
   542   }
   544   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
   545   // Do NOT remove the next line: ensure a new alias index is allocated
   546   // for the instance type. Note: C++ will not remove it since the call
   547   // has side effect.
   548   int alias_idx = _compile->get_alias_index(tinst);
   549   igvn->set_type(addp, tinst);
   550   // record the allocation in the node map
   551   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
   552   set_map(addp->_idx, get_map(base->_idx));
   554   // Set addp's Base and Address to 'base'.
   555   Node *abase = addp->in(AddPNode::Base);
   556   Node *adr   = addp->in(AddPNode::Address);
   557   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
   558       adr->in(0)->_idx == (uint)inst_id) {
   559     // Skip AddP cases #3 and #5.
   560   } else {
   561     assert(!abase->is_top(), "sanity"); // AddP case #3
   562     if (abase != base) {
   563       igvn->hash_delete(addp);
   564       addp->set_req(AddPNode::Base, base);
   565       if (abase == adr) {
   566         addp->set_req(AddPNode::Address, base);
   567       } else {
   568         // AddP case #4 (adr is array's element offset AddP node)
   569 #ifdef ASSERT
   570         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
   571         assert(adr->is_AddP() && atype != NULL &&
   572                atype->instance_id() == inst_id, "array's element offset should be processed first");
   573 #endif
   574       }
   575       igvn->hash_insert(addp);
   576     }
   577   }
   578   // Put on IGVN worklist since at least addp's type was changed above.
   579   record_for_optimizer(addp);
   580   return true;
   581 }
   583 //
   584 // Create a new version of orig_phi if necessary. Returns either the newly
   585 // created phi or an existing phi.  Sets create_new to indicate wheter  a new
   586 // phi was created.  Cache the last newly created phi in the node map.
   587 //
   588 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
   589   Compile *C = _compile;
   590   new_created = false;
   591   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
   592   // nothing to do if orig_phi is bottom memory or matches alias_idx
   593   if (phi_alias_idx == alias_idx) {
   594     return orig_phi;
   595   }
   596   // Have we recently created a Phi for this alias index?
   597   PhiNode *result = get_map_phi(orig_phi->_idx);
   598   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
   599     return result;
   600   }
   601   // Previous check may fail when the same wide memory Phi was split into Phis
   602   // for different memory slices. Search all Phis for this region.
   603   if (result != NULL) {
   604     Node* region = orig_phi->in(0);
   605     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
   606       Node* phi = region->fast_out(i);
   607       if (phi->is_Phi() &&
   608           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
   609         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
   610         return phi->as_Phi();
   611       }
   612     }
   613   }
   614   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
   615     if (C->do_escape_analysis() == true && !C->failing()) {
   616       // Retry compilation without escape analysis.
   617       // If this is the first failure, the sentinel string will "stick"
   618       // to the Compile object, and the C2Compiler will see it and retry.
   619       C->record_failure(C2Compiler::retry_no_escape_analysis());
   620     }
   621     return NULL;
   622   }
   623   orig_phi_worklist.append_if_missing(orig_phi);
   624   const TypePtr *atype = C->get_adr_type(alias_idx);
   625   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
   626   C->copy_node_notes_to(result, orig_phi);
   627   igvn->set_type(result, result->bottom_type());
   628   record_for_optimizer(result);
   630   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
   631   assert(pn == NULL || pn == orig_phi, "wrong node");
   632   set_map(orig_phi->_idx, result);
   633   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
   635   new_created = true;
   636   return result;
   637 }
   639 //
   640 // Return a new version  of Memory Phi "orig_phi" with the inputs having the
   641 // specified alias index.
   642 //
   643 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
   645   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
   646   Compile *C = _compile;
   647   bool new_phi_created;
   648   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
   649   if (!new_phi_created) {
   650     return result;
   651   }
   653   GrowableArray<PhiNode *>  phi_list;
   654   GrowableArray<uint>  cur_input;
   656   PhiNode *phi = orig_phi;
   657   uint idx = 1;
   658   bool finished = false;
   659   while(!finished) {
   660     while (idx < phi->req()) {
   661       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
   662       if (mem != NULL && mem->is_Phi()) {
   663         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
   664         if (new_phi_created) {
   665           // found an phi for which we created a new split, push current one on worklist and begin
   666           // processing new one
   667           phi_list.push(phi);
   668           cur_input.push(idx);
   669           phi = mem->as_Phi();
   670           result = newphi;
   671           idx = 1;
   672           continue;
   673         } else {
   674           mem = newphi;
   675         }
   676       }
   677       if (C->failing()) {
   678         return NULL;
   679       }
   680       result->set_req(idx++, mem);
   681     }
   682 #ifdef ASSERT
   683     // verify that the new Phi has an input for each input of the original
   684     assert( phi->req() == result->req(), "must have same number of inputs.");
   685     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
   686 #endif
   687     // Check if all new phi's inputs have specified alias index.
   688     // Otherwise use old phi.
   689     for (uint i = 1; i < phi->req(); i++) {
   690       Node* in = result->in(i);
   691       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
   692     }
   693     // we have finished processing a Phi, see if there are any more to do
   694     finished = (phi_list.length() == 0 );
   695     if (!finished) {
   696       phi = phi_list.pop();
   697       idx = cur_input.pop();
   698       PhiNode *prev_result = get_map_phi(phi->_idx);
   699       prev_result->set_req(idx++, result);
   700       result = prev_result;
   701     }
   702   }
   703   return result;
   704 }
   707 //
   708 // The next methods are derived from methods in MemNode.
   709 //
   710 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
   711   Node *mem = mmem;
   712   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
   713   // means an array I have not precisely typed yet.  Do not do any
   714   // alias stuff with it any time soon.
   715   if( toop->base() != Type::AnyPtr &&
   716       !(toop->klass() != NULL &&
   717         toop->klass()->is_java_lang_Object() &&
   718         toop->offset() == Type::OffsetBot) ) {
   719     mem = mmem->memory_at(alias_idx);
   720     // Update input if it is progress over what we have now
   721   }
   722   return mem;
   723 }
   725 //
   726 // Move memory users to their memory slices.
   727 //
   728 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
   729   Compile* C = _compile;
   731   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
   732   assert(tp != NULL, "ptr type");
   733   int alias_idx = C->get_alias_index(tp);
   734   int general_idx = C->get_general_index(alias_idx);
   736   // Move users first
   737   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
   738     Node* use = n->fast_out(i);
   739     if (use->is_MergeMem()) {
   740       MergeMemNode* mmem = use->as_MergeMem();
   741       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
   742       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
   743         continue; // Nothing to do
   744       }
   745       // Replace previous general reference to mem node.
   746       uint orig_uniq = C->unique();
   747       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   748       assert(orig_uniq == C->unique(), "no new nodes");
   749       mmem->set_memory_at(general_idx, m);
   750       --imax;
   751       --i;
   752     } else if (use->is_MemBar()) {
   753       assert(!use->is_Initialize(), "initializing stores should not be moved");
   754       if (use->req() > MemBarNode::Precedent &&
   755           use->in(MemBarNode::Precedent) == n) {
   756         // Don't move related membars.
   757         record_for_optimizer(use);
   758         continue;
   759       }
   760       tp = use->as_MemBar()->adr_type()->isa_ptr();
   761       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
   762           alias_idx == general_idx) {
   763         continue; // Nothing to do
   764       }
   765       // Move to general memory slice.
   766       uint orig_uniq = C->unique();
   767       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   768       assert(orig_uniq == C->unique(), "no new nodes");
   769       igvn->hash_delete(use);
   770       imax -= use->replace_edge(n, m);
   771       igvn->hash_insert(use);
   772       record_for_optimizer(use);
   773       --i;
   774 #ifdef ASSERT
   775     } else if (use->is_Mem()) {
   776       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
   777         // Don't move related cardmark.
   778         continue;
   779       }
   780       // Memory nodes should have new memory input.
   781       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
   782       assert(tp != NULL, "ptr type");
   783       int idx = C->get_alias_index(tp);
   784       assert(get_map(use->_idx) != NULL || idx == alias_idx,
   785              "Following memory nodes should have new memory input or be on the same memory slice");
   786     } else if (use->is_Phi()) {
   787       // Phi nodes should be split and moved already.
   788       tp = use->as_Phi()->adr_type()->isa_ptr();
   789       assert(tp != NULL, "ptr type");
   790       int idx = C->get_alias_index(tp);
   791       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
   792     } else {
   793       use->dump();
   794       assert(false, "should not be here");
   795 #endif
   796     }
   797   }
   798 }
   800 //
   801 // Search memory chain of "mem" to find a MemNode whose address
   802 // is the specified alias index.
   803 //
   804 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
   805   if (orig_mem == NULL)
   806     return orig_mem;
   807   Compile* C = phase->C;
   808   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
   809   bool is_instance = (toop != NULL) && toop->is_known_instance();
   810   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   811   Node *prev = NULL;
   812   Node *result = orig_mem;
   813   while (prev != result) {
   814     prev = result;
   815     if (result == start_mem)
   816       break;  // hit one of our sentinels
   817     if (result->is_Mem()) {
   818       const Type *at = phase->type(result->in(MemNode::Address));
   819       if (at != Type::TOP) {
   820         assert (at->isa_ptr() != NULL, "pointer type required.");
   821         int idx = C->get_alias_index(at->is_ptr());
   822         if (idx == alias_idx)
   823           break;
   824       }
   825       result = result->in(MemNode::Memory);
   826     }
   827     if (!is_instance)
   828       continue;  // don't search further for non-instance types
   829     // skip over a call which does not affect this memory slice
   830     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
   831       Node *proj_in = result->in(0);
   832       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
   833         break;  // hit one of our sentinels
   834       } else if (proj_in->is_Call()) {
   835         CallNode *call = proj_in->as_Call();
   836         if (!call->may_modify(toop, phase)) {
   837           result = call->in(TypeFunc::Memory);
   838         }
   839       } else if (proj_in->is_Initialize()) {
   840         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
   841         // Stop if this is the initialization for the object instance which
   842         // which contains this memory slice, otherwise skip over it.
   843         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
   844           result = proj_in->in(TypeFunc::Memory);
   845         }
   846       } else if (proj_in->is_MemBar()) {
   847         result = proj_in->in(TypeFunc::Memory);
   848       }
   849     } else if (result->is_MergeMem()) {
   850       MergeMemNode *mmem = result->as_MergeMem();
   851       result = step_through_mergemem(mmem, alias_idx, toop);
   852       if (result == mmem->base_memory()) {
   853         // Didn't find instance memory, search through general slice recursively.
   854         result = mmem->memory_at(C->get_general_index(alias_idx));
   855         result = find_inst_mem(result, alias_idx, orig_phis, phase);
   856         if (C->failing()) {
   857           return NULL;
   858         }
   859         mmem->set_memory_at(alias_idx, result);
   860       }
   861     } else if (result->is_Phi() &&
   862                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
   863       Node *un = result->as_Phi()->unique_input(phase);
   864       if (un != NULL) {
   865         orig_phis.append_if_missing(result->as_Phi());
   866         result = un;
   867       } else {
   868         break;
   869       }
   870     } else if (result->is_ClearArray()) {
   871       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
   872         // Can not bypass initialization of the instance
   873         // we are looking for.
   874         break;
   875       }
   876       // Otherwise skip it (the call updated 'result' value).
   877     } else if (result->Opcode() == Op_SCMemProj) {
   878       assert(result->in(0)->is_LoadStore(), "sanity");
   879       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
   880       if (at != Type::TOP) {
   881         assert (at->isa_ptr() != NULL, "pointer type required.");
   882         int idx = C->get_alias_index(at->is_ptr());
   883         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
   884         break;
   885       }
   886       result = result->in(0)->in(MemNode::Memory);
   887     }
   888   }
   889   if (result->is_Phi()) {
   890     PhiNode *mphi = result->as_Phi();
   891     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
   892     const TypePtr *t = mphi->adr_type();
   893     if (C->get_alias_index(t) != alias_idx) {
   894       // Create a new Phi with the specified alias index type.
   895       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
   896     } else if (!is_instance) {
   897       // Push all non-instance Phis on the orig_phis worklist to update inputs
   898       // during Phase 4 if needed.
   899       orig_phis.append_if_missing(mphi);
   900     }
   901   }
   902   // the result is either MemNode, PhiNode, InitializeNode.
   903   return result;
   904 }
   906 //
   907 //  Convert the types of unescaped object to instance types where possible,
   908 //  propagate the new type information through the graph, and update memory
   909 //  edges and MergeMem inputs to reflect the new type.
   910 //
   911 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
   912 //  The processing is done in 4 phases:
   913 //
   914 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
   915 //            types for the CheckCastPP for allocations where possible.
   916 //            Propagate the the new types through users as follows:
   917 //               casts and Phi:  push users on alloc_worklist
   918 //               AddP:  cast Base and Address inputs to the instance type
   919 //                      push any AddP users on alloc_worklist and push any memnode
   920 //                      users onto memnode_worklist.
   921 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
   922 //            search the Memory chain for a store with the appropriate type
   923 //            address type.  If a Phi is found, create a new version with
   924 //            the appropriate memory slices from each of the Phi inputs.
   925 //            For stores, process the users as follows:
   926 //               MemNode:  push on memnode_worklist
   927 //               MergeMem: push on mergemem_worklist
   928 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
   929 //            moving the first node encountered of each  instance type to the
   930 //            the input corresponding to its alias index.
   931 //            appropriate memory slice.
   932 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
   933 //
   934 // In the following example, the CheckCastPP nodes are the cast of allocation
   935 // results and the allocation of node 29 is unescaped and eligible to be an
   936 // instance type.
   937 //
   938 // We start with:
   939 //
   940 //     7 Parm #memory
   941 //    10  ConI  "12"
   942 //    19  CheckCastPP   "Foo"
   943 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   944 //    29  CheckCastPP   "Foo"
   945 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
   946 //
   947 //    40  StoreP  25   7  20   ... alias_index=4
   948 //    50  StoreP  35  40  30   ... alias_index=4
   949 //    60  StoreP  45  50  20   ... alias_index=4
   950 //    70  LoadP    _  60  30   ... alias_index=4
   951 //    80  Phi     75  50  60   Memory alias_index=4
   952 //    90  LoadP    _  80  30   ... alias_index=4
   953 //   100  LoadP    _  80  20   ... alias_index=4
   954 //
   955 //
   956 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
   957 // and creating a new alias index for node 30.  This gives:
   958 //
   959 //     7 Parm #memory
   960 //    10  ConI  "12"
   961 //    19  CheckCastPP   "Foo"
   962 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   963 //    29  CheckCastPP   "Foo"  iid=24
   964 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
   965 //
   966 //    40  StoreP  25   7  20   ... alias_index=4
   967 //    50  StoreP  35  40  30   ... alias_index=6
   968 //    60  StoreP  45  50  20   ... alias_index=4
   969 //    70  LoadP    _  60  30   ... alias_index=6
   970 //    80  Phi     75  50  60   Memory alias_index=4
   971 //    90  LoadP    _  80  30   ... alias_index=6
   972 //   100  LoadP    _  80  20   ... alias_index=4
   973 //
   974 // In phase 2, new memory inputs are computed for the loads and stores,
   975 // And a new version of the phi is created.  In phase 4, the inputs to
   976 // node 80 are updated and then the memory nodes are updated with the
   977 // values computed in phase 2.  This results in:
   978 //
   979 //     7 Parm #memory
   980 //    10  ConI  "12"
   981 //    19  CheckCastPP   "Foo"
   982 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   983 //    29  CheckCastPP   "Foo"  iid=24
   984 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
   985 //
   986 //    40  StoreP  25  7   20   ... alias_index=4
   987 //    50  StoreP  35  7   30   ... alias_index=6
   988 //    60  StoreP  45  40  20   ... alias_index=4
   989 //    70  LoadP    _  50  30   ... alias_index=6
   990 //    80  Phi     75  40  60   Memory alias_index=4
   991 //   120  Phi     75  50  50   Memory alias_index=6
   992 //    90  LoadP    _ 120  30   ... alias_index=6
   993 //   100  LoadP    _  80  20   ... alias_index=4
   994 //
   995 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
   996   GrowableArray<Node *>  memnode_worklist;
   997   GrowableArray<PhiNode *>  orig_phis;
   999   PhaseIterGVN  *igvn = _igvn;
  1000   uint new_index_start = (uint) _compile->num_alias_types();
  1001   Arena* arena = Thread::current()->resource_area();
  1002   VectorSet visited(arena);
  1003   VectorSet ptset(arena);
  1006   //  Phase 1:  Process possible allocations from alloc_worklist.
  1007   //  Create instance types for the CheckCastPP for allocations where possible.
  1008   //
  1009   // (Note: don't forget to change the order of the second AddP node on
  1010   //  the alloc_worklist if the order of the worklist processing is changed,
  1011   //  see the comment in find_second_addp().)
  1012   //
  1013   while (alloc_worklist.length() != 0) {
  1014     Node *n = alloc_worklist.pop();
  1015     uint ni = n->_idx;
  1016     const TypeOopPtr* tinst = NULL;
  1017     if (n->is_Call()) {
  1018       CallNode *alloc = n->as_Call();
  1019       // copy escape information to call node
  1020       PointsToNode* ptn = ptnode_adr(alloc->_idx);
  1021       PointsToNode::EscapeState es = escape_state(alloc);
  1022       // We have an allocation or call which returns a Java object,
  1023       // see if it is unescaped.
  1024       if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
  1025         continue;
  1027       // Find CheckCastPP for the allocate or for the return value of a call
  1028       n = alloc->result_cast();
  1029       if (n == NULL) {            // No uses except Initialize node
  1030         if (alloc->is_Allocate()) {
  1031           // Set the scalar_replaceable flag for allocation
  1032           // so it could be eliminated if it has no uses.
  1033           alloc->as_Allocate()->_is_scalar_replaceable = true;
  1035         continue;
  1037       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
  1038         assert(!alloc->is_Allocate(), "allocation should have unique type");
  1039         continue;
  1042       // The inline code for Object.clone() casts the allocation result to
  1043       // java.lang.Object and then to the actual type of the allocated
  1044       // object. Detect this case and use the second cast.
  1045       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
  1046       // the allocation result is cast to java.lang.Object and then
  1047       // to the actual Array type.
  1048       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
  1049           && (alloc->is_AllocateArray() ||
  1050               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
  1051         Node *cast2 = NULL;
  1052         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1053           Node *use = n->fast_out(i);
  1054           if (use->is_CheckCastPP()) {
  1055             cast2 = use;
  1056             break;
  1059         if (cast2 != NULL) {
  1060           n = cast2;
  1061         } else {
  1062           // Non-scalar replaceable if the allocation type is unknown statically
  1063           // (reflection allocation), the object can't be restored during
  1064           // deoptimization without precise type.
  1065           continue;
  1068       if (alloc->is_Allocate()) {
  1069         // Set the scalar_replaceable flag for allocation
  1070         // so it could be eliminated.
  1071         alloc->as_Allocate()->_is_scalar_replaceable = true;
  1073       set_escape_state(n->_idx, es);
  1074       // in order for an object to be scalar-replaceable, it must be:
  1075       //   - a direct allocation (not a call returning an object)
  1076       //   - non-escaping
  1077       //   - eligible to be a unique type
  1078       //   - not determined to be ineligible by escape analysis
  1079       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
  1080              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
  1081       set_map(alloc->_idx, n);
  1082       set_map(n->_idx, alloc);
  1083       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
  1084       if (t == NULL)
  1085         continue;  // not a TypeInstPtr
  1086       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
  1087       igvn->hash_delete(n);
  1088       igvn->set_type(n,  tinst);
  1089       n->raise_bottom_type(tinst);
  1090       igvn->hash_insert(n);
  1091       record_for_optimizer(n);
  1092       if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
  1093           (t->isa_instptr() || t->isa_aryptr())) {
  1095         // First, put on the worklist all Field edges from Connection Graph
  1096         // which is more accurate then putting immediate users from Ideal Graph.
  1097         for (uint e = 0; e < ptn->edge_count(); e++) {
  1098           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
  1099           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
  1100                  "only AddP nodes are Field edges in CG");
  1101           if (use->outcnt() > 0) { // Don't process dead nodes
  1102             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
  1103             if (addp2 != NULL) {
  1104               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1105               alloc_worklist.append_if_missing(addp2);
  1107             alloc_worklist.append_if_missing(use);
  1111         // An allocation may have an Initialize which has raw stores. Scan
  1112         // the users of the raw allocation result and push AddP users
  1113         // on alloc_worklist.
  1114         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
  1115         assert (raw_result != NULL, "must have an allocation result");
  1116         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
  1117           Node *use = raw_result->fast_out(i);
  1118           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
  1119             Node* addp2 = find_second_addp(use, raw_result);
  1120             if (addp2 != NULL) {
  1121               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1122               alloc_worklist.append_if_missing(addp2);
  1124             alloc_worklist.append_if_missing(use);
  1125           } else if (use->is_MemBar()) {
  1126             memnode_worklist.append_if_missing(use);
  1130     } else if (n->is_AddP()) {
  1131       ptset.Clear();
  1132       PointsTo(ptset, get_addp_base(n));
  1133       assert(ptset.Size() == 1, "AddP address is unique");
  1134       uint elem = ptset.getelem(); // Allocation node's index
  1135       if (elem == _phantom_object) {
  1136         assert(false, "escaped allocation");
  1137         continue; // Assume the value was set outside this method.
  1139       Node *base = get_map(elem);  // CheckCastPP node
  1140       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
  1141       tinst = igvn->type(base)->isa_oopptr();
  1142     } else if (n->is_Phi() ||
  1143                n->is_CheckCastPP() ||
  1144                n->is_EncodeP() ||
  1145                n->is_DecodeN() ||
  1146                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
  1147       if (visited.test_set(n->_idx)) {
  1148         assert(n->is_Phi(), "loops only through Phi's");
  1149         continue;  // already processed
  1151       ptset.Clear();
  1152       PointsTo(ptset, n);
  1153       if (ptset.Size() == 1) {
  1154         uint elem = ptset.getelem(); // Allocation node's index
  1155         if (elem == _phantom_object) {
  1156           assert(false, "escaped allocation");
  1157           continue; // Assume the value was set outside this method.
  1159         Node *val = get_map(elem);   // CheckCastPP node
  1160         TypeNode *tn = n->as_Type();
  1161         tinst = igvn->type(val)->isa_oopptr();
  1162         assert(tinst != NULL && tinst->is_known_instance() &&
  1163                (uint)tinst->instance_id() == elem , "instance type expected.");
  1165         const Type *tn_type = igvn->type(tn);
  1166         const TypeOopPtr *tn_t;
  1167         if (tn_type->isa_narrowoop()) {
  1168           tn_t = tn_type->make_ptr()->isa_oopptr();
  1169         } else {
  1170           tn_t = tn_type->isa_oopptr();
  1173         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
  1174           if (tn_type->isa_narrowoop()) {
  1175             tn_type = tinst->make_narrowoop();
  1176           } else {
  1177             tn_type = tinst;
  1179           igvn->hash_delete(tn);
  1180           igvn->set_type(tn, tn_type);
  1181           tn->set_type(tn_type);
  1182           igvn->hash_insert(tn);
  1183           record_for_optimizer(n);
  1184         } else {
  1185           assert(tn_type == TypePtr::NULL_PTR ||
  1186                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
  1187                  "unexpected type");
  1188           continue; // Skip dead path with different type
  1191     } else {
  1192       debug_only(n->dump();)
  1193       assert(false, "EA: unexpected node");
  1194       continue;
  1196     // push allocation's users on appropriate worklist
  1197     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1198       Node *use = n->fast_out(i);
  1199       if(use->is_Mem() && use->in(MemNode::Address) == n) {
  1200         // Load/store to instance's field
  1201         memnode_worklist.append_if_missing(use);
  1202       } else if (use->is_MemBar()) {
  1203         memnode_worklist.append_if_missing(use);
  1204       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
  1205         Node* addp2 = find_second_addp(use, n);
  1206         if (addp2 != NULL) {
  1207           alloc_worklist.append_if_missing(addp2);
  1209         alloc_worklist.append_if_missing(use);
  1210       } else if (use->is_Phi() ||
  1211                  use->is_CheckCastPP() ||
  1212                  use->is_EncodeP() ||
  1213                  use->is_DecodeN() ||
  1214                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
  1215         alloc_worklist.append_if_missing(use);
  1216 #ifdef ASSERT
  1217       } else if (use->is_Mem()) {
  1218         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
  1219       } else if (use->is_MergeMem()) {
  1220         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1221       } else if (use->is_SafePoint()) {
  1222         // Look for MergeMem nodes for calls which reference unique allocation
  1223         // (through CheckCastPP nodes) even for debug info.
  1224         Node* m = use->in(TypeFunc::Memory);
  1225         if (m->is_MergeMem()) {
  1226           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1228       } else {
  1229         uint op = use->Opcode();
  1230         if (!(op == Op_CmpP || op == Op_Conv2B ||
  1231               op == Op_CastP2X || op == Op_StoreCM ||
  1232               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
  1233               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1234           n->dump();
  1235           use->dump();
  1236           assert(false, "EA: missing allocation reference path");
  1238 #endif
  1243   // New alias types were created in split_AddP().
  1244   uint new_index_end = (uint) _compile->num_alias_types();
  1246   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
  1247   //            compute new values for Memory inputs  (the Memory inputs are not
  1248   //            actually updated until phase 4.)
  1249   if (memnode_worklist.length() == 0)
  1250     return;  // nothing to do
  1252   while (memnode_worklist.length() != 0) {
  1253     Node *n = memnode_worklist.pop();
  1254     if (visited.test_set(n->_idx))
  1255       continue;
  1256     if (n->is_Phi() || n->is_ClearArray()) {
  1257       // we don't need to do anything, but the users must be pushed
  1258     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
  1259       // we don't need to do anything, but the users must be pushed
  1260       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
  1261       if (n == NULL)
  1262         continue;
  1263     } else {
  1264       assert(n->is_Mem(), "memory node required.");
  1265       Node *addr = n->in(MemNode::Address);
  1266       const Type *addr_t = igvn->type(addr);
  1267       if (addr_t == Type::TOP)
  1268         continue;
  1269       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
  1270       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
  1271       assert ((uint)alias_idx < new_index_end, "wrong alias index");
  1272       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
  1273       if (_compile->failing()) {
  1274         return;
  1276       if (mem != n->in(MemNode::Memory)) {
  1277         // We delay the memory edge update since we need old one in
  1278         // MergeMem code below when instances memory slices are separated.
  1279         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
  1280         assert(pn == NULL || pn == n, "wrong node");
  1281         set_map(n->_idx, mem);
  1282         ptnode_adr(n->_idx)->_node = n;
  1284       if (n->is_Load()) {
  1285         continue;  // don't push users
  1286       } else if (n->is_LoadStore()) {
  1287         // get the memory projection
  1288         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1289           Node *use = n->fast_out(i);
  1290           if (use->Opcode() == Op_SCMemProj) {
  1291             n = use;
  1292             break;
  1295         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
  1298     // push user on appropriate worklist
  1299     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1300       Node *use = n->fast_out(i);
  1301       if (use->is_Phi() || use->is_ClearArray()) {
  1302         memnode_worklist.append_if_missing(use);
  1303       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
  1304         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
  1305           continue;
  1306         memnode_worklist.append_if_missing(use);
  1307       } else if (use->is_MemBar()) {
  1308         memnode_worklist.append_if_missing(use);
  1309 #ifdef ASSERT
  1310       } else if(use->is_Mem()) {
  1311         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
  1312       } else if (use->is_MergeMem()) {
  1313         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1314       } else {
  1315         uint op = use->Opcode();
  1316         if (!(op == Op_StoreCM ||
  1317               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
  1318                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
  1319               op == Op_AryEq || op == Op_StrComp ||
  1320               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1321           n->dump();
  1322           use->dump();
  1323           assert(false, "EA: missing memory path");
  1325 #endif
  1330   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
  1331   //            Walk each memory slice moving the first node encountered of each
  1332   //            instance type to the the input corresponding to its alias index.
  1333   uint length = _mergemem_worklist.length();
  1334   for( uint next = 0; next < length; ++next ) {
  1335     MergeMemNode* nmm = _mergemem_worklist.at(next);
  1336     assert(!visited.test_set(nmm->_idx), "should not be visited before");
  1337     // Note: we don't want to use MergeMemStream here because we only want to
  1338     // scan inputs which exist at the start, not ones we add during processing.
  1339     // Note 2: MergeMem may already contains instance memory slices added
  1340     // during find_inst_mem() call when memory nodes were processed above.
  1341     igvn->hash_delete(nmm);
  1342     uint nslices = nmm->req();
  1343     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
  1344       Node* mem = nmm->in(i);
  1345       Node* cur = NULL;
  1346       if (mem == NULL || mem->is_top())
  1347         continue;
  1348       // First, update mergemem by moving memory nodes to corresponding slices
  1349       // if their type became more precise since this mergemem was created.
  1350       while (mem->is_Mem()) {
  1351         const Type *at = igvn->type(mem->in(MemNode::Address));
  1352         if (at != Type::TOP) {
  1353           assert (at->isa_ptr() != NULL, "pointer type required.");
  1354           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
  1355           if (idx == i) {
  1356             if (cur == NULL)
  1357               cur = mem;
  1358           } else {
  1359             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
  1360               nmm->set_memory_at(idx, mem);
  1364         mem = mem->in(MemNode::Memory);
  1366       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
  1367       // Find any instance of the current type if we haven't encountered
  1368       // already a memory slice of the instance along the memory chain.
  1369       for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1370         if((uint)_compile->get_general_index(ni) == i) {
  1371           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
  1372           if (nmm->is_empty_memory(m)) {
  1373             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
  1374             if (_compile->failing()) {
  1375               return;
  1377             nmm->set_memory_at(ni, result);
  1382     // Find the rest of instances values
  1383     for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1384       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
  1385       Node* result = step_through_mergemem(nmm, ni, tinst);
  1386       if (result == nmm->base_memory()) {
  1387         // Didn't find instance memory, search through general slice recursively.
  1388         result = nmm->memory_at(_compile->get_general_index(ni));
  1389         result = find_inst_mem(result, ni, orig_phis, igvn);
  1390         if (_compile->failing()) {
  1391           return;
  1393         nmm->set_memory_at(ni, result);
  1396     igvn->hash_insert(nmm);
  1397     record_for_optimizer(nmm);
  1400   //  Phase 4:  Update the inputs of non-instance memory Phis and
  1401   //            the Memory input of memnodes
  1402   // First update the inputs of any non-instance Phi's from
  1403   // which we split out an instance Phi.  Note we don't have
  1404   // to recursively process Phi's encounted on the input memory
  1405   // chains as is done in split_memory_phi() since they  will
  1406   // also be processed here.
  1407   for (int j = 0; j < orig_phis.length(); j++) {
  1408     PhiNode *phi = orig_phis.at(j);
  1409     int alias_idx = _compile->get_alias_index(phi->adr_type());
  1410     igvn->hash_delete(phi);
  1411     for (uint i = 1; i < phi->req(); i++) {
  1412       Node *mem = phi->in(i);
  1413       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
  1414       if (_compile->failing()) {
  1415         return;
  1417       if (mem != new_mem) {
  1418         phi->set_req(i, new_mem);
  1421     igvn->hash_insert(phi);
  1422     record_for_optimizer(phi);
  1425   // Update the memory inputs of MemNodes with the value we computed
  1426   // in Phase 2 and move stores memory users to corresponding memory slices.
  1427 #ifdef ASSERT
  1428   visited.Clear();
  1429   Node_Stack old_mems(arena, _compile->unique() >> 2);
  1430 #endif
  1431   for (uint i = 0; i < nodes_size(); i++) {
  1432     Node *nmem = get_map(i);
  1433     if (nmem != NULL) {
  1434       Node *n = ptnode_adr(i)->_node;
  1435       assert(n != NULL, "sanity");
  1436       if (n->is_Mem()) {
  1437 #ifdef ASSERT
  1438         Node* old_mem = n->in(MemNode::Memory);
  1439         if (!visited.test_set(old_mem->_idx)) {
  1440           old_mems.push(old_mem, old_mem->outcnt());
  1442 #endif
  1443         assert(n->in(MemNode::Memory) != nmem, "sanity");
  1444         if (!n->is_Load()) {
  1445           // Move memory users of a store first.
  1446           move_inst_mem(n, orig_phis, igvn);
  1448         // Now update memory input
  1449         igvn->hash_delete(n);
  1450         n->set_req(MemNode::Memory, nmem);
  1451         igvn->hash_insert(n);
  1452         record_for_optimizer(n);
  1453       } else {
  1454         assert(n->is_Allocate() || n->is_CheckCastPP() ||
  1455                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
  1459 #ifdef ASSERT
  1460   // Verify that memory was split correctly
  1461   while (old_mems.is_nonempty()) {
  1462     Node* old_mem = old_mems.node();
  1463     uint  old_cnt = old_mems.index();
  1464     old_mems.pop();
  1465     assert(old_cnt = old_mem->outcnt(), "old mem could be lost");
  1467 #endif
  1470 bool ConnectionGraph::has_candidates(Compile *C) {
  1471   // EA brings benefits only when the code has allocations and/or locks which
  1472   // are represented by ideal Macro nodes.
  1473   int cnt = C->macro_count();
  1474   for( int i=0; i < cnt; i++ ) {
  1475     Node *n = C->macro_node(i);
  1476     if ( n->is_Allocate() )
  1477       return true;
  1478     if( n->is_Lock() ) {
  1479       Node* obj = n->as_Lock()->obj_node()->uncast();
  1480       if( !(obj->is_Parm() || obj->is_Con()) )
  1481         return true;
  1484   return false;
  1487 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  1488   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  1489   // to create space for them in ConnectionGraph::_nodes[].
  1490   Node* oop_null = igvn->zerocon(T_OBJECT);
  1491   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  1493   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  1494   // Perform escape analysis
  1495   if (congraph->compute_escape()) {
  1496     // There are non escaping objects.
  1497     C->set_congraph(congraph);
  1500   // Cleanup.
  1501   if (oop_null->outcnt() == 0)
  1502     igvn->hash_delete(oop_null);
  1503   if (noop_null->outcnt() == 0)
  1504     igvn->hash_delete(noop_null);
  1507 bool ConnectionGraph::compute_escape() {
  1508   Compile* C = _compile;
  1510   // 1. Populate Connection Graph (CG) with Ideal nodes.
  1512   Unique_Node_List worklist_init;
  1513   worklist_init.map(C->unique(), NULL);  // preallocate space
  1515   // Initialize worklist
  1516   if (C->root() != NULL) {
  1517     worklist_init.push(C->root());
  1520   GrowableArray<int> cg_worklist;
  1521   PhaseGVN* igvn = _igvn;
  1522   bool has_allocations = false;
  1524   // Push all useful nodes onto CG list and set their type.
  1525   for( uint next = 0; next < worklist_init.size(); ++next ) {
  1526     Node* n = worklist_init.at(next);
  1527     record_for_escape_analysis(n, igvn);
  1528     // Only allocations and java static calls results are checked
  1529     // for an escape status. See process_call_result() below.
  1530     if (n->is_Allocate() || n->is_CallStaticJava() &&
  1531         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
  1532       has_allocations = true;
  1534     if(n->is_AddP()) {
  1535       // Collect address nodes. Use them during stage 3 below
  1536       // to build initial connection graph field edges.
  1537       cg_worklist.append(n->_idx);
  1538     } else if (n->is_MergeMem()) {
  1539       // Collect all MergeMem nodes to add memory slices for
  1540       // scalar replaceable objects in split_unique_types().
  1541       _mergemem_worklist.append(n->as_MergeMem());
  1543     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1544       Node* m = n->fast_out(i);   // Get user
  1545       worklist_init.push(m);
  1549   if (!has_allocations) {
  1550     _collecting = false;
  1551     return false; // Nothing to do.
  1554   // 2. First pass to create simple CG edges (doesn't require to walk CG).
  1555   uint delayed_size = _delayed_worklist.size();
  1556   for( uint next = 0; next < delayed_size; ++next ) {
  1557     Node* n = _delayed_worklist.at(next);
  1558     build_connection_graph(n, igvn);
  1561   // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
  1562   //    to reduce number of iterations during stage 4 below.
  1563   uint cg_length = cg_worklist.length();
  1564   for( uint next = 0; next < cg_length; ++next ) {
  1565     int ni = cg_worklist.at(next);
  1566     Node* n = ptnode_adr(ni)->_node;
  1567     Node* base = get_addp_base(n);
  1568     if (base->is_Proj())
  1569       base = base->in(0);
  1570     PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
  1571     if (nt == PointsToNode::JavaObject) {
  1572       build_connection_graph(n, igvn);
  1576   cg_worklist.clear();
  1577   cg_worklist.append(_phantom_object);
  1578   GrowableArray<uint>  worklist;
  1580   // 4. Build Connection Graph which need
  1581   //    to walk the connection graph.
  1582   _progress = false;
  1583   for (uint ni = 0; ni < nodes_size(); ni++) {
  1584     PointsToNode* ptn = ptnode_adr(ni);
  1585     Node *n = ptn->_node;
  1586     if (n != NULL) { // Call, AddP, LoadP, StoreP
  1587       build_connection_graph(n, igvn);
  1588       if (ptn->node_type() != PointsToNode::UnknownType)
  1589         cg_worklist.append(n->_idx); // Collect CG nodes
  1590       if (!_processed.test(n->_idx))
  1591         worklist.append(n->_idx); // Collect C/A/L/S nodes
  1595   // After IGVN user nodes may have smaller _idx than
  1596   // their inputs so they will be processed first in
  1597   // previous loop. Because of that not all Graph
  1598   // edges will be created. Walk over interesting
  1599   // nodes again until no new edges are created.
  1600   //
  1601   // Normally only 1-3 passes needed to build
  1602   // Connection Graph depending on graph complexity.
  1603   // Set limit to 10 to catch situation when something
  1604   // did go wrong and recompile the method without EA.
  1606 #define CG_BUILD_ITER_LIMIT 10
  1608   uint length = worklist.length();
  1609   int iterations = 0;
  1610   while(_progress && (iterations++ < CG_BUILD_ITER_LIMIT)) {
  1611     _progress = false;
  1612     for( uint next = 0; next < length; ++next ) {
  1613       int ni = worklist.at(next);
  1614       PointsToNode* ptn = ptnode_adr(ni);
  1615       Node* n = ptn->_node;
  1616       assert(n != NULL, "should be known node");
  1617       build_connection_graph(n, igvn);
  1620   if (iterations >= CG_BUILD_ITER_LIMIT) {
  1621     assert(iterations < CG_BUILD_ITER_LIMIT,
  1622            err_msg("infinite EA connection graph build with %d nodes and worklist size %d",
  1623            nodes_size(), length));
  1624     // Possible infinite build_connection_graph loop,
  1625     // retry compilation without escape analysis.
  1626     C->record_failure(C2Compiler::retry_no_escape_analysis());
  1627     _collecting = false;
  1628     return false;
  1630 #undef CG_BUILD_ITER_LIMIT
  1632   Arena* arena = Thread::current()->resource_area();
  1633   VectorSet ptset(arena);
  1634   VectorSet visited(arena);
  1635   worklist.clear();
  1637   // 5. Remove deferred edges from the graph and adjust
  1638   //    escape state of nonescaping objects.
  1639   cg_length = cg_worklist.length();
  1640   for( uint next = 0; next < cg_length; ++next ) {
  1641     int ni = cg_worklist.at(next);
  1642     PointsToNode* ptn = ptnode_adr(ni);
  1643     PointsToNode::NodeType nt = ptn->node_type();
  1644     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
  1645       remove_deferred(ni, &worklist, &visited);
  1646       Node *n = ptn->_node;
  1647       if (n->is_AddP()) {
  1648         // Search for objects which are not scalar replaceable
  1649         // and adjust their escape state.
  1650         verify_escape_state(ni, ptset, igvn);
  1655   // 6. Propagate escape states.
  1656   worklist.clear();
  1657   bool has_non_escaping_obj = false;
  1659   // push all GlobalEscape nodes on the worklist
  1660   for( uint next = 0; next < cg_length; ++next ) {
  1661     int nk = cg_worklist.at(next);
  1662     if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
  1663       worklist.push(nk);
  1665   // mark all nodes reachable from GlobalEscape nodes
  1666   while(worklist.length() > 0) {
  1667     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1668     uint e_cnt = ptn->edge_count();
  1669     for (uint ei = 0; ei < e_cnt; ei++) {
  1670       uint npi = ptn->edge_target(ei);
  1671       PointsToNode *np = ptnode_adr(npi);
  1672       if (np->escape_state() < PointsToNode::GlobalEscape) {
  1673         np->set_escape_state(PointsToNode::GlobalEscape);
  1674         worklist.push(npi);
  1679   // push all ArgEscape nodes on the worklist
  1680   for( uint next = 0; next < cg_length; ++next ) {
  1681     int nk = cg_worklist.at(next);
  1682     if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
  1683       worklist.push(nk);
  1685   // mark all nodes reachable from ArgEscape nodes
  1686   while(worklist.length() > 0) {
  1687     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1688     if (ptn->node_type() == PointsToNode::JavaObject)
  1689       has_non_escaping_obj = true; // Non GlobalEscape
  1690     uint e_cnt = ptn->edge_count();
  1691     for (uint ei = 0; ei < e_cnt; ei++) {
  1692       uint npi = ptn->edge_target(ei);
  1693       PointsToNode *np = ptnode_adr(npi);
  1694       if (np->escape_state() < PointsToNode::ArgEscape) {
  1695         np->set_escape_state(PointsToNode::ArgEscape);
  1696         worklist.push(npi);
  1701   GrowableArray<Node*> alloc_worklist;
  1703   // push all NoEscape nodes on the worklist
  1704   for( uint next = 0; next < cg_length; ++next ) {
  1705     int nk = cg_worklist.at(next);
  1706     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
  1707       worklist.push(nk);
  1709   // mark all nodes reachable from NoEscape nodes
  1710   while(worklist.length() > 0) {
  1711     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1712     if (ptn->node_type() == PointsToNode::JavaObject)
  1713       has_non_escaping_obj = true; // Non GlobalEscape
  1714     Node* n = ptn->_node;
  1715     if (n->is_Allocate() && ptn->_scalar_replaceable ) {
  1716       // Push scalar replaceable allocations on alloc_worklist
  1717       // for processing in split_unique_types().
  1718       alloc_worklist.append(n);
  1720     uint e_cnt = ptn->edge_count();
  1721     for (uint ei = 0; ei < e_cnt; ei++) {
  1722       uint npi = ptn->edge_target(ei);
  1723       PointsToNode *np = ptnode_adr(npi);
  1724       if (np->escape_state() < PointsToNode::NoEscape) {
  1725         np->set_escape_state(PointsToNode::NoEscape);
  1726         worklist.push(npi);
  1731   _collecting = false;
  1732   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
  1734 #ifndef PRODUCT
  1735   if (PrintEscapeAnalysis) {
  1736     dump(); // Dump ConnectionGraph
  1738 #endif
  1740   bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
  1741   if ( has_scalar_replaceable_candidates &&
  1742        C->AliasLevel() >= 3 && EliminateAllocations ) {
  1744     // Now use the escape information to create unique types for
  1745     // scalar replaceable objects.
  1746     split_unique_types(alloc_worklist);
  1748     if (C->failing())  return false;
  1750     C->print_method("After Escape Analysis", 2);
  1752 #ifdef ASSERT
  1753   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
  1754     tty->print("=== No allocations eliminated for ");
  1755     C->method()->print_short_name();
  1756     if(!EliminateAllocations) {
  1757       tty->print(" since EliminateAllocations is off ===");
  1758     } else if(!has_scalar_replaceable_candidates) {
  1759       tty->print(" since there are no scalar replaceable candidates ===");
  1760     } else if(C->AliasLevel() < 3) {
  1761       tty->print(" since AliasLevel < 3 ===");
  1763     tty->cr();
  1764 #endif
  1766   return has_non_escaping_obj;
  1769 // Search for objects which are not scalar replaceable.
  1770 void ConnectionGraph::verify_escape_state(int nidx, VectorSet& ptset, PhaseTransform* phase) {
  1771   PointsToNode* ptn = ptnode_adr(nidx);
  1772   Node* n = ptn->_node;
  1773   assert(n->is_AddP(), "Should be called for AddP nodes only");
  1774   // Search for objects which are not scalar replaceable.
  1775   // Mark their escape state as ArgEscape to propagate the state
  1776   // to referenced objects.
  1777   // Note: currently there are no difference in compiler optimizations
  1778   // for ArgEscape objects and NoEscape objects which are not
  1779   // scalar replaceable.
  1781   Compile* C = _compile;
  1783   int offset = ptn->offset();
  1784   Node* base = get_addp_base(n);
  1785   ptset.Clear();
  1786   PointsTo(ptset, base);
  1787   int ptset_size = ptset.Size();
  1789   // Check if a oop field's initializing value is recorded and add
  1790   // a corresponding NULL field's value if it is not recorded.
  1791   // Connection Graph does not record a default initialization by NULL
  1792   // captured by Initialize node.
  1793   //
  1794   // Note: it will disable scalar replacement in some cases:
  1795   //
  1796   //    Point p[] = new Point[1];
  1797   //    p[0] = new Point(); // Will be not scalar replaced
  1798   //
  1799   // but it will save us from incorrect optimizations in next cases:
  1800   //
  1801   //    Point p[] = new Point[1];
  1802   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
  1803   //
  1804   // Do a simple control flow analysis to distinguish above cases.
  1805   //
  1806   if (offset != Type::OffsetBot && ptset_size == 1) {
  1807     uint elem = ptset.getelem(); // Allocation node's index
  1808     // It does not matter if it is not Allocation node since
  1809     // only non-escaping allocations are scalar replaced.
  1810     if (ptnode_adr(elem)->_node->is_Allocate() &&
  1811         ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
  1812       AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
  1813       InitializeNode* ini = alloc->initialization();
  1815       // Check only oop fields.
  1816       const Type* adr_type = n->as_AddP()->bottom_type();
  1817       BasicType basic_field_type = T_INT;
  1818       if (adr_type->isa_instptr()) {
  1819         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
  1820         if (field != NULL) {
  1821           basic_field_type = field->layout_type();
  1822         } else {
  1823           // Ignore non field load (for example, klass load)
  1825       } else if (adr_type->isa_aryptr()) {
  1826         const Type* elemtype = adr_type->isa_aryptr()->elem();
  1827         basic_field_type = elemtype->array_element_basic_type();
  1828       } else {
  1829         // Raw pointers are used for initializing stores so skip it.
  1830         assert(adr_type->isa_rawptr() && base->is_Proj() &&
  1831                (base->in(0) == alloc),"unexpected pointer type");
  1833       if (basic_field_type == T_OBJECT ||
  1834           basic_field_type == T_NARROWOOP ||
  1835           basic_field_type == T_ARRAY) {
  1836         Node* value = NULL;
  1837         if (ini != NULL) {
  1838           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
  1839           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
  1840           if (store != NULL && store->is_Store()) {
  1841             value = store->in(MemNode::ValueIn);
  1842           } else if (ptn->edge_count() > 0) { // Are there oop stores?
  1843             // Check for a store which follows allocation without branches.
  1844             // For example, a volatile field store is not collected
  1845             // by Initialize node. TODO: it would be nice to use idom() here.
  1846             for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1847               store = n->fast_out(i);
  1848               if (store->is_Store() && store->in(0) != NULL) {
  1849                 Node* ctrl = store->in(0);
  1850                 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
  1851                         ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
  1852                         ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
  1853                    ctrl = ctrl->in(0);
  1855                 if (ctrl == ini || ctrl == alloc) {
  1856                   value = store->in(MemNode::ValueIn);
  1857                   break;
  1863         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
  1864           // A field's initializing value was not recorded. Add NULL.
  1865           uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
  1866           add_pointsto_edge(nidx, null_idx);
  1872   // An object is not scalar replaceable if the field which may point
  1873   // to it has unknown offset (unknown element of an array of objects).
  1874   //
  1875   if (offset == Type::OffsetBot) {
  1876     uint e_cnt = ptn->edge_count();
  1877     for (uint ei = 0; ei < e_cnt; ei++) {
  1878       uint npi = ptn->edge_target(ei);
  1879       set_escape_state(npi, PointsToNode::ArgEscape);
  1880       ptnode_adr(npi)->_scalar_replaceable = false;
  1884   // Currently an object is not scalar replaceable if a LoadStore node
  1885   // access its field since the field value is unknown after it.
  1886   //
  1887   bool has_LoadStore = false;
  1888   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1889     Node *use = n->fast_out(i);
  1890     if (use->is_LoadStore()) {
  1891       has_LoadStore = true;
  1892       break;
  1895   // An object is not scalar replaceable if the address points
  1896   // to unknown field (unknown element for arrays, offset is OffsetBot).
  1897   //
  1898   // Or the address may point to more then one object. This may produce
  1899   // the false positive result (set scalar_replaceable to false)
  1900   // since the flow-insensitive escape analysis can't separate
  1901   // the case when stores overwrite the field's value from the case
  1902   // when stores happened on different control branches.
  1903   //
  1904   if (ptset_size > 1 || ptset_size != 0 &&
  1905       (has_LoadStore || offset == Type::OffsetBot)) {
  1906     for( VectorSetI j(&ptset); j.test(); ++j ) {
  1907       set_escape_state(j.elem, PointsToNode::ArgEscape);
  1908       ptnode_adr(j.elem)->_scalar_replaceable = false;
  1913 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
  1915     switch (call->Opcode()) {
  1916 #ifdef ASSERT
  1917     case Op_Allocate:
  1918     case Op_AllocateArray:
  1919     case Op_Lock:
  1920     case Op_Unlock:
  1921       assert(false, "should be done already");
  1922       break;
  1923 #endif
  1924     case Op_CallLeaf:
  1925     case Op_CallLeafNoFP:
  1927       // Stub calls, objects do not escape but they are not scale replaceable.
  1928       // Adjust escape state for outgoing arguments.
  1929       const TypeTuple * d = call->tf()->domain();
  1930       VectorSet ptset(Thread::current()->resource_area());
  1931       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1932         const Type* at = d->field_at(i);
  1933         Node *arg = call->in(i)->uncast();
  1934         const Type *aat = phase->type(arg);
  1935         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
  1936             ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
  1938           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
  1939                  aat->isa_ptr() != NULL, "expecting an Ptr");
  1940 #ifdef ASSERT
  1941           if (!(call->Opcode() == Op_CallLeafNoFP &&
  1942                 call->as_CallLeaf()->_name != NULL &&
  1943                 (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
  1944                 call->as_CallLeaf()->_name != NULL &&
  1945                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
  1946                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
  1947           ) {
  1948             call->dump();
  1949             assert(false, "EA: unexpected CallLeaf");
  1951 #endif
  1952           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  1953           if (arg->is_AddP()) {
  1954             //
  1955             // The inline_native_clone() case when the arraycopy stub is called
  1956             // after the allocation before Initialize and CheckCastPP nodes.
  1957             //
  1958             // Set AddP's base (Allocate) as not scalar replaceable since
  1959             // pointer to the base (with offset) is passed as argument.
  1960             //
  1961             arg = get_addp_base(arg);
  1963           ptset.Clear();
  1964           PointsTo(ptset, arg);
  1965           for( VectorSetI j(&ptset); j.test(); ++j ) {
  1966             uint pt = j.elem;
  1967             set_escape_state(pt, PointsToNode::ArgEscape);
  1971       break;
  1974     case Op_CallStaticJava:
  1975     // For a static call, we know exactly what method is being called.
  1976     // Use bytecode estimator to record the call's escape affects
  1978       ciMethod *meth = call->as_CallJava()->method();
  1979       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
  1980       // fall-through if not a Java method or no analyzer information
  1981       if (call_analyzer != NULL) {
  1982         const TypeTuple * d = call->tf()->domain();
  1983         VectorSet ptset(Thread::current()->resource_area());
  1984         bool copy_dependencies = false;
  1985         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1986           const Type* at = d->field_at(i);
  1987           int k = i - TypeFunc::Parms;
  1988           Node *arg = call->in(i)->uncast();
  1990           if (at->isa_oopptr() != NULL &&
  1991               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
  1993             bool global_escapes = false;
  1994             bool fields_escapes = false;
  1995             if (!call_analyzer->is_arg_stack(k)) {
  1996               // The argument global escapes, mark everything it could point to
  1997               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  1998               global_escapes = true;
  1999             } else {
  2000               if (!call_analyzer->is_arg_local(k)) {
  2001                 // The argument itself doesn't escape, but any fields might
  2002                 fields_escapes = true;
  2004               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  2005               copy_dependencies = true;
  2008             ptset.Clear();
  2009             PointsTo(ptset, arg);
  2010             for( VectorSetI j(&ptset); j.test(); ++j ) {
  2011               uint pt = j.elem;
  2012               if (global_escapes) {
  2013                 //The argument global escapes, mark everything it could point to
  2014                 set_escape_state(pt, PointsToNode::GlobalEscape);
  2015               } else {
  2016                 if (fields_escapes) {
  2017                   // The argument itself doesn't escape, but any fields might
  2018                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  2020                 set_escape_state(pt, PointsToNode::ArgEscape);
  2025         if (copy_dependencies)
  2026           call_analyzer->copy_dependencies(_compile->dependencies());
  2027         break;
  2031     default:
  2032     // Fall-through here if not a Java method or no analyzer information
  2033     // or some other type of call, assume the worst case: all arguments
  2034     // globally escape.
  2036       // adjust escape state for  outgoing arguments
  2037       const TypeTuple * d = call->tf()->domain();
  2038       VectorSet ptset(Thread::current()->resource_area());
  2039       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2040         const Type* at = d->field_at(i);
  2041         if (at->isa_oopptr() != NULL) {
  2042           Node *arg = call->in(i)->uncast();
  2043           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2044           ptset.Clear();
  2045           PointsTo(ptset, arg);
  2046           for( VectorSetI j(&ptset); j.test(); ++j ) {
  2047             uint pt = j.elem;
  2048             set_escape_state(pt, PointsToNode::GlobalEscape);
  2055 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
  2056   CallNode   *call = resproj->in(0)->as_Call();
  2057   uint    call_idx = call->_idx;
  2058   uint resproj_idx = resproj->_idx;
  2060   switch (call->Opcode()) {
  2061     case Op_Allocate:
  2063       Node *k = call->in(AllocateNode::KlassNode);
  2064       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2065       assert(kt != NULL, "TypeKlassPtr  required.");
  2066       ciKlass* cik = kt->klass();
  2068       PointsToNode::EscapeState es;
  2069       uint edge_to;
  2070       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
  2071          !cik->is_instance_klass() || // StressReflectiveCode
  2072           cik->as_instance_klass()->has_finalizer()) {
  2073         es = PointsToNode::GlobalEscape;
  2074         edge_to = _phantom_object; // Could not be worse
  2075       } else {
  2076         es = PointsToNode::NoEscape;
  2077         edge_to = call_idx;
  2079       set_escape_state(call_idx, es);
  2080       add_pointsto_edge(resproj_idx, edge_to);
  2081       _processed.set(resproj_idx);
  2082       break;
  2085     case Op_AllocateArray:
  2088       Node *k = call->in(AllocateNode::KlassNode);
  2089       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2090       assert(kt != NULL, "TypeKlassPtr  required.");
  2091       ciKlass* cik = kt->klass();
  2093       PointsToNode::EscapeState es;
  2094       uint edge_to;
  2095       if (!cik->is_array_klass()) { // StressReflectiveCode
  2096         es = PointsToNode::GlobalEscape;
  2097         edge_to = _phantom_object;
  2098       } else {
  2099         es = PointsToNode::NoEscape;
  2100         edge_to = call_idx;
  2101         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
  2102         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
  2103           // Not scalar replaceable if the length is not constant or too big.
  2104           ptnode_adr(call_idx)->_scalar_replaceable = false;
  2107       set_escape_state(call_idx, es);
  2108       add_pointsto_edge(resproj_idx, edge_to);
  2109       _processed.set(resproj_idx);
  2110       break;
  2113     case Op_CallStaticJava:
  2114     // For a static call, we know exactly what method is being called.
  2115     // Use bytecode estimator to record whether the call's return value escapes
  2117       bool done = true;
  2118       const TypeTuple *r = call->tf()->range();
  2119       const Type* ret_type = NULL;
  2121       if (r->cnt() > TypeFunc::Parms)
  2122         ret_type = r->field_at(TypeFunc::Parms);
  2124       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2125       //        _multianewarray functions return a TypeRawPtr.
  2126       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
  2127         _processed.set(resproj_idx);
  2128         break;  // doesn't return a pointer type
  2130       ciMethod *meth = call->as_CallJava()->method();
  2131       const TypeTuple * d = call->tf()->domain();
  2132       if (meth == NULL) {
  2133         // not a Java method, assume global escape
  2134         set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2135         add_pointsto_edge(resproj_idx, _phantom_object);
  2136       } else {
  2137         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
  2138         bool copy_dependencies = false;
  2140         if (call_analyzer->is_return_allocated()) {
  2141           // Returns a newly allocated unescaped object, simply
  2142           // update dependency information.
  2143           // Mark it as NoEscape so that objects referenced by
  2144           // it's fields will be marked as NoEscape at least.
  2145           set_escape_state(call_idx, PointsToNode::NoEscape);
  2146           add_pointsto_edge(resproj_idx, call_idx);
  2147           copy_dependencies = true;
  2148         } else if (call_analyzer->is_return_local()) {
  2149           // determine whether any arguments are returned
  2150           set_escape_state(call_idx, PointsToNode::NoEscape);
  2151           bool ret_arg = false;
  2152           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2153             const Type* at = d->field_at(i);
  2155             if (at->isa_oopptr() != NULL) {
  2156               Node *arg = call->in(i)->uncast();
  2158               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
  2159                 ret_arg = true;
  2160                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2161                 if (arg_esp->node_type() == PointsToNode::UnknownType)
  2162                   done = false;
  2163                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
  2164                   add_pointsto_edge(resproj_idx, arg->_idx);
  2165                 else
  2166                   add_deferred_edge(resproj_idx, arg->_idx);
  2167                 arg_esp->_hidden_alias = true;
  2171           if (done && !ret_arg) {
  2172             // Returns unknown object.
  2173             set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2174             add_pointsto_edge(resproj_idx, _phantom_object);
  2176           copy_dependencies = true;
  2177         } else {
  2178           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2179           add_pointsto_edge(resproj_idx, _phantom_object);
  2180           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2181             const Type* at = d->field_at(i);
  2182             if (at->isa_oopptr() != NULL) {
  2183               Node *arg = call->in(i)->uncast();
  2184               PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2185               arg_esp->_hidden_alias = true;
  2189         if (copy_dependencies)
  2190           call_analyzer->copy_dependencies(_compile->dependencies());
  2192       if (done)
  2193         _processed.set(resproj_idx);
  2194       break;
  2197     default:
  2198     // Some other type of call, assume the worst case that the
  2199     // returned value, if any, globally escapes.
  2201       const TypeTuple *r = call->tf()->range();
  2202       if (r->cnt() > TypeFunc::Parms) {
  2203         const Type* ret_type = r->field_at(TypeFunc::Parms);
  2205         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2206         //        _multianewarray functions return a TypeRawPtr.
  2207         if (ret_type->isa_ptr() != NULL) {
  2208           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2209           add_pointsto_edge(resproj_idx, _phantom_object);
  2212       _processed.set(resproj_idx);
  2217 // Populate Connection Graph with Ideal nodes and create simple
  2218 // connection graph edges (do not need to check the node_type of inputs
  2219 // or to call PointsTo() to walk the connection graph).
  2220 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
  2221   if (_processed.test(n->_idx))
  2222     return; // No need to redefine node's state.
  2224   if (n->is_Call()) {
  2225     // Arguments to allocation and locking don't escape.
  2226     if (n->is_Allocate()) {
  2227       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
  2228       record_for_optimizer(n);
  2229     } else if (n->is_Lock() || n->is_Unlock()) {
  2230       // Put Lock and Unlock nodes on IGVN worklist to process them during
  2231       // the first IGVN optimization when escape information is still available.
  2232       record_for_optimizer(n);
  2233       _processed.set(n->_idx);
  2234     } else {
  2235       // Don't mark as processed since call's arguments have to be processed.
  2236       PointsToNode::NodeType nt = PointsToNode::UnknownType;
  2237       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
  2239       // Check if a call returns an object.
  2240       const TypeTuple *r = n->as_Call()->tf()->range();
  2241       if (r->cnt() > TypeFunc::Parms &&
  2242           r->field_at(TypeFunc::Parms)->isa_ptr() &&
  2243           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
  2244         nt = PointsToNode::JavaObject;
  2245         if (!n->is_CallStaticJava()) {
  2246           // Since the called mathod is statically unknown assume
  2247           // the worst case that the returned value globally escapes.
  2248           es = PointsToNode::GlobalEscape;
  2251       add_node(n, nt, es, false);
  2253     return;
  2256   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
  2257   // ThreadLocal has RawPrt type.
  2258   switch (n->Opcode()) {
  2259     case Op_AddP:
  2261       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
  2262       break;
  2264     case Op_CastX2P:
  2265     { // "Unsafe" memory access.
  2266       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2267       break;
  2269     case Op_CastPP:
  2270     case Op_CheckCastPP:
  2271     case Op_EncodeP:
  2272     case Op_DecodeN:
  2274       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2275       int ti = n->in(1)->_idx;
  2276       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2277       if (nt == PointsToNode::UnknownType) {
  2278         _delayed_worklist.push(n); // Process it later.
  2279         break;
  2280       } else if (nt == PointsToNode::JavaObject) {
  2281         add_pointsto_edge(n->_idx, ti);
  2282       } else {
  2283         add_deferred_edge(n->_idx, ti);
  2285       _processed.set(n->_idx);
  2286       break;
  2288     case Op_ConP:
  2290       // assume all pointer constants globally escape except for null
  2291       PointsToNode::EscapeState es;
  2292       if (phase->type(n) == TypePtr::NULL_PTR)
  2293         es = PointsToNode::NoEscape;
  2294       else
  2295         es = PointsToNode::GlobalEscape;
  2297       add_node(n, PointsToNode::JavaObject, es, true);
  2298       break;
  2300     case Op_ConN:
  2302       // assume all narrow oop constants globally escape except for null
  2303       PointsToNode::EscapeState es;
  2304       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
  2305         es = PointsToNode::NoEscape;
  2306       else
  2307         es = PointsToNode::GlobalEscape;
  2309       add_node(n, PointsToNode::JavaObject, es, true);
  2310       break;
  2312     case Op_CreateEx:
  2314       // assume that all exception objects globally escape
  2315       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2316       break;
  2318     case Op_LoadKlass:
  2319     case Op_LoadNKlass:
  2321       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2322       break;
  2324     case Op_LoadP:
  2325     case Op_LoadN:
  2327       const Type *t = phase->type(n);
  2328       if (t->make_ptr() == NULL) {
  2329         _processed.set(n->_idx);
  2330         return;
  2332       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2333       break;
  2335     case Op_Parm:
  2337       _processed.set(n->_idx); // No need to redefine it state.
  2338       uint con = n->as_Proj()->_con;
  2339       if (con < TypeFunc::Parms)
  2340         return;
  2341       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
  2342       if (t->isa_ptr() == NULL)
  2343         return;
  2344       // We have to assume all input parameters globally escape
  2345       // (Note: passing 'false' since _processed is already set).
  2346       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
  2347       break;
  2349     case Op_Phi:
  2351       const Type *t = n->as_Phi()->type();
  2352       if (t->make_ptr() == NULL) {
  2353         // nothing to do if not an oop or narrow oop
  2354         _processed.set(n->_idx);
  2355         return;
  2357       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2358       uint i;
  2359       for (i = 1; i < n->req() ; i++) {
  2360         Node* in = n->in(i);
  2361         if (in == NULL)
  2362           continue;  // ignore NULL
  2363         in = in->uncast();
  2364         if (in->is_top() || in == n)
  2365           continue;  // ignore top or inputs which go back this node
  2366         int ti = in->_idx;
  2367         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2368         if (nt == PointsToNode::UnknownType) {
  2369           break;
  2370         } else if (nt == PointsToNode::JavaObject) {
  2371           add_pointsto_edge(n->_idx, ti);
  2372         } else {
  2373           add_deferred_edge(n->_idx, ti);
  2376       if (i >= n->req())
  2377         _processed.set(n->_idx);
  2378       else
  2379         _delayed_worklist.push(n);
  2380       break;
  2382     case Op_Proj:
  2384       // we are only interested in the oop result projection from a call
  2385       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2386         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2387         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2388         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2389           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2390           int ti = n->in(0)->_idx;
  2391           // The call may not be registered yet (since not all its inputs are registered)
  2392           // if this is the projection from backbranch edge of Phi.
  2393           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
  2394             process_call_result(n->as_Proj(), phase);
  2396           if (!_processed.test(n->_idx)) {
  2397             // The call's result may need to be processed later if the call
  2398             // returns it's argument and the argument is not processed yet.
  2399             _delayed_worklist.push(n);
  2401           break;
  2404       _processed.set(n->_idx);
  2405       break;
  2407     case Op_Return:
  2409       if( n->req() > TypeFunc::Parms &&
  2410           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2411         // Treat Return value as LocalVar with GlobalEscape escape state.
  2412         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
  2413         int ti = n->in(TypeFunc::Parms)->_idx;
  2414         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2415         if (nt == PointsToNode::UnknownType) {
  2416           _delayed_worklist.push(n); // Process it later.
  2417           break;
  2418         } else if (nt == PointsToNode::JavaObject) {
  2419           add_pointsto_edge(n->_idx, ti);
  2420         } else {
  2421           add_deferred_edge(n->_idx, ti);
  2424       _processed.set(n->_idx);
  2425       break;
  2427     case Op_StoreP:
  2428     case Op_StoreN:
  2430       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2431       adr_type = adr_type->make_ptr();
  2432       if (adr_type->isa_oopptr()) {
  2433         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2434       } else {
  2435         Node* adr = n->in(MemNode::Address);
  2436         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
  2437             adr->in(AddPNode::Address)->is_Proj() &&
  2438             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
  2439           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2440           // We are computing a raw address for a store captured
  2441           // by an Initialize compute an appropriate address type.
  2442           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
  2443           assert(offs != Type::OffsetBot, "offset must be a constant");
  2444         } else {
  2445           _processed.set(n->_idx);
  2446           return;
  2449       break;
  2451     case Op_StorePConditional:
  2452     case Op_CompareAndSwapP:
  2453     case Op_CompareAndSwapN:
  2455       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2456       adr_type = adr_type->make_ptr();
  2457       if (adr_type->isa_oopptr()) {
  2458         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2459       } else {
  2460         _processed.set(n->_idx);
  2461         return;
  2463       break;
  2465     case Op_AryEq:
  2466     case Op_StrComp:
  2467     case Op_StrEquals:
  2468     case Op_StrIndexOf:
  2470       // char[] arrays passed to string intrinsics are not scalar replaceable.
  2471       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2472       break;
  2474     case Op_ThreadLocal:
  2476       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
  2477       break;
  2479     default:
  2481       // nothing to do
  2483   return;
  2486 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
  2487   uint n_idx = n->_idx;
  2488   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
  2490   // Don't set processed bit for AddP, LoadP, StoreP since
  2491   // they may need more then one pass to process.
  2492   // Also don't mark as processed Call nodes since their
  2493   // arguments may need more then one pass to process.
  2494   if (_processed.test(n_idx))
  2495     return; // No need to redefine node's state.
  2497   if (n->is_Call()) {
  2498     CallNode *call = n->as_Call();
  2499     process_call_arguments(call, phase);
  2500     return;
  2503   switch (n->Opcode()) {
  2504     case Op_AddP:
  2506       Node *base = get_addp_base(n);
  2507       // Create a field edge to this node from everything base could point to.
  2508       VectorSet ptset(Thread::current()->resource_area());
  2509       PointsTo(ptset, base);
  2510       for( VectorSetI i(&ptset); i.test(); ++i ) {
  2511         uint pt = i.elem;
  2512         add_field_edge(pt, n_idx, address_offset(n, phase));
  2514       break;
  2516     case Op_CastX2P:
  2518       assert(false, "Op_CastX2P");
  2519       break;
  2521     case Op_CastPP:
  2522     case Op_CheckCastPP:
  2523     case Op_EncodeP:
  2524     case Op_DecodeN:
  2526       int ti = n->in(1)->_idx;
  2527       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
  2528       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2529         add_pointsto_edge(n_idx, ti);
  2530       } else {
  2531         add_deferred_edge(n_idx, ti);
  2533       _processed.set(n_idx);
  2534       break;
  2536     case Op_ConP:
  2538       assert(false, "Op_ConP");
  2539       break;
  2541     case Op_ConN:
  2543       assert(false, "Op_ConN");
  2544       break;
  2546     case Op_CreateEx:
  2548       assert(false, "Op_CreateEx");
  2549       break;
  2551     case Op_LoadKlass:
  2552     case Op_LoadNKlass:
  2554       assert(false, "Op_LoadKlass");
  2555       break;
  2557     case Op_LoadP:
  2558     case Op_LoadN:
  2560       const Type *t = phase->type(n);
  2561 #ifdef ASSERT
  2562       if (t->make_ptr() == NULL)
  2563         assert(false, "Op_LoadP");
  2564 #endif
  2566       Node* adr = n->in(MemNode::Address)->uncast();
  2567       Node* adr_base;
  2568       if (adr->is_AddP()) {
  2569         adr_base = get_addp_base(adr);
  2570       } else {
  2571         adr_base = adr;
  2574       // For everything "adr_base" could point to, create a deferred edge from
  2575       // this node to each field with the same offset.
  2576       VectorSet ptset(Thread::current()->resource_area());
  2577       PointsTo(ptset, adr_base);
  2578       int offset = address_offset(adr, phase);
  2579       for( VectorSetI i(&ptset); i.test(); ++i ) {
  2580         uint pt = i.elem;
  2581         add_deferred_edge_to_fields(n_idx, pt, offset);
  2583       break;
  2585     case Op_Parm:
  2587       assert(false, "Op_Parm");
  2588       break;
  2590     case Op_Phi:
  2592 #ifdef ASSERT
  2593       const Type *t = n->as_Phi()->type();
  2594       if (t->make_ptr() == NULL)
  2595         assert(false, "Op_Phi");
  2596 #endif
  2597       for (uint i = 1; i < n->req() ; i++) {
  2598         Node* in = n->in(i);
  2599         if (in == NULL)
  2600           continue;  // ignore NULL
  2601         in = in->uncast();
  2602         if (in->is_top() || in == n)
  2603           continue;  // ignore top or inputs which go back this node
  2604         int ti = in->_idx;
  2605         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2606         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
  2607         if (nt == PointsToNode::JavaObject) {
  2608           add_pointsto_edge(n_idx, ti);
  2609         } else {
  2610           add_deferred_edge(n_idx, ti);
  2613       _processed.set(n_idx);
  2614       break;
  2616     case Op_Proj:
  2618       // we are only interested in the oop result projection from a call
  2619       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2620         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
  2621                "all nodes should be registered");
  2622         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2623         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2624         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2625           process_call_result(n->as_Proj(), phase);
  2626           assert(_processed.test(n_idx), "all call results should be processed");
  2627           break;
  2630       assert(false, "Op_Proj");
  2631       break;
  2633     case Op_Return:
  2635 #ifdef ASSERT
  2636       if( n->req() <= TypeFunc::Parms ||
  2637           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2638         assert(false, "Op_Return");
  2640 #endif
  2641       int ti = n->in(TypeFunc::Parms)->_idx;
  2642       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
  2643       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2644         add_pointsto_edge(n_idx, ti);
  2645       } else {
  2646         add_deferred_edge(n_idx, ti);
  2648       _processed.set(n_idx);
  2649       break;
  2651     case Op_StoreP:
  2652     case Op_StoreN:
  2653     case Op_StorePConditional:
  2654     case Op_CompareAndSwapP:
  2655     case Op_CompareAndSwapN:
  2657       Node *adr = n->in(MemNode::Address);
  2658       const Type *adr_type = phase->type(adr)->make_ptr();
  2659 #ifdef ASSERT
  2660       if (!adr_type->isa_oopptr())
  2661         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
  2662 #endif
  2664       assert(adr->is_AddP(), "expecting an AddP");
  2665       Node *adr_base = get_addp_base(adr);
  2666       Node *val = n->in(MemNode::ValueIn)->uncast();
  2667       // For everything "adr_base" could point to, create a deferred edge
  2668       // to "val" from each field with the same offset.
  2669       VectorSet ptset(Thread::current()->resource_area());
  2670       PointsTo(ptset, adr_base);
  2671       for( VectorSetI i(&ptset); i.test(); ++i ) {
  2672         uint pt = i.elem;
  2673         add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
  2675       break;
  2677     case Op_AryEq:
  2678     case Op_StrComp:
  2679     case Op_StrEquals:
  2680     case Op_StrIndexOf:
  2682       // char[] arrays passed to string intrinsic do not escape but
  2683       // they are not scalar replaceable. Adjust escape state for them.
  2684       // Start from in(2) edge since in(1) is memory edge.
  2685       for (uint i = 2; i < n->req(); i++) {
  2686         Node* adr = n->in(i)->uncast();
  2687         const Type *at = phase->type(adr);
  2688         if (!adr->is_top() && at->isa_ptr()) {
  2689           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
  2690                  at->isa_ptr() != NULL, "expecting an Ptr");
  2691           if (adr->is_AddP()) {
  2692             adr = get_addp_base(adr);
  2694           // Mark as ArgEscape everything "adr" could point to.
  2695           set_escape_state(adr->_idx, PointsToNode::ArgEscape);
  2698       _processed.set(n_idx);
  2699       break;
  2701     case Op_ThreadLocal:
  2703       assert(false, "Op_ThreadLocal");
  2704       break;
  2706     default:
  2707       // This method should be called only for EA specific nodes.
  2708       ShouldNotReachHere();
  2712 #ifndef PRODUCT
  2713 void ConnectionGraph::dump() {
  2714   bool first = true;
  2716   uint size = nodes_size();
  2717   for (uint ni = 0; ni < size; ni++) {
  2718     PointsToNode *ptn = ptnode_adr(ni);
  2719     PointsToNode::NodeType ptn_type = ptn->node_type();
  2721     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
  2722       continue;
  2723     PointsToNode::EscapeState es = escape_state(ptn->_node);
  2724     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
  2725       if (first) {
  2726         tty->cr();
  2727         tty->print("======== Connection graph for ");
  2728         _compile->method()->print_short_name();
  2729         tty->cr();
  2730         first = false;
  2732       tty->print("%6d ", ni);
  2733       ptn->dump();
  2734       // Print all locals which reference this allocation
  2735       for (uint li = ni; li < size; li++) {
  2736         PointsToNode *ptn_loc = ptnode_adr(li);
  2737         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
  2738         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
  2739              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
  2740           ptnode_adr(li)->dump(false);
  2743       if (Verbose) {
  2744         // Print all fields which reference this allocation
  2745         for (uint i = 0; i < ptn->edge_count(); i++) {
  2746           uint ei = ptn->edge_target(i);
  2747           ptnode_adr(ei)->dump(false);
  2750       tty->cr();
  2754 #endif

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