src/share/vm/opto/escape.cpp

Wed, 20 Apr 2011 18:29:35 -0700

author
kvn
date
Wed, 20 Apr 2011 18:29:35 -0700
changeset 2810
66b0e2371912
parent 2741
55973726c600
child 2951
642c68c75db9
permissions
-rw-r--r--

7026700: regression in 6u24-rev-b23: Crash in C2 compiler in PhaseIdealLoop::build_loop_late_post
Summary: memory slices should be always created for non-static fields after allocation
Reviewed-by: never

     1 /*
     2  * Copyright (c) 2005, 2011, 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 "precompiled.hpp"
    26 #include "ci/bcEscapeAnalyzer.hpp"
    27 #include "libadt/vectset.hpp"
    28 #include "memory/allocation.hpp"
    29 #include "opto/c2compiler.hpp"
    30 #include "opto/callnode.hpp"
    31 #include "opto/cfgnode.hpp"
    32 #include "opto/compile.hpp"
    33 #include "opto/escape.hpp"
    34 #include "opto/phaseX.hpp"
    35 #include "opto/rootnode.hpp"
    37 void PointsToNode::add_edge(uint targIdx, PointsToNode::EdgeType et) {
    38   uint v = (targIdx << EdgeShift) + ((uint) et);
    39   if (_edges == NULL) {
    40      Arena *a = Compile::current()->comp_arena();
    41     _edges = new(a) GrowableArray<uint>(a, INITIAL_EDGE_COUNT, 0, 0);
    42   }
    43   _edges->append_if_missing(v);
    44 }
    46 void PointsToNode::remove_edge(uint targIdx, PointsToNode::EdgeType et) {
    47   uint v = (targIdx << EdgeShift) + ((uint) et);
    49   _edges->remove(v);
    50 }
    52 #ifndef PRODUCT
    53 static const char *node_type_names[] = {
    54   "UnknownType",
    55   "JavaObject",
    56   "LocalVar",
    57   "Field"
    58 };
    60 static const char *esc_names[] = {
    61   "UnknownEscape",
    62   "NoEscape",
    63   "ArgEscape",
    64   "GlobalEscape"
    65 };
    67 static const char *edge_type_suffix[] = {
    68  "?", // UnknownEdge
    69  "P", // PointsToEdge
    70  "D", // DeferredEdge
    71  "F"  // FieldEdge
    72 };
    74 void PointsToNode::dump(bool print_state) const {
    75   NodeType nt = node_type();
    76   tty->print("%s ", node_type_names[(int) nt]);
    77   if (print_state) {
    78     EscapeState es = escape_state();
    79     tty->print("%s %s ", esc_names[(int) es], _scalar_replaceable ? "":"NSR");
    80   }
    81   tty->print("[[");
    82   for (uint i = 0; i < edge_count(); i++) {
    83     tty->print(" %d%s", edge_target(i), edge_type_suffix[(int) edge_type(i)]);
    84   }
    85   tty->print("]]  ");
    86   if (_node == NULL)
    87     tty->print_cr("<null>");
    88   else
    89     _node->dump();
    90 }
    91 #endif
    93 ConnectionGraph::ConnectionGraph(Compile * C, PhaseIterGVN *igvn) :
    94   _nodes(C->comp_arena(), C->unique(), C->unique(), PointsToNode()),
    95   _processed(C->comp_arena()),
    96   pt_ptset(C->comp_arena()),
    97   pt_visited(C->comp_arena()),
    98   pt_worklist(C->comp_arena(), 4, 0, 0),
    99   _collecting(true),
   100   _progress(false),
   101   _compile(C),
   102   _igvn(igvn),
   103   _node_map(C->comp_arena()) {
   105   _phantom_object = C->top()->_idx,
   106   add_node(C->top(), PointsToNode::JavaObject, PointsToNode::GlobalEscape,true);
   108   // Add ConP(#NULL) and ConN(#NULL) nodes.
   109   Node* oop_null = igvn->zerocon(T_OBJECT);
   110   _oop_null = oop_null->_idx;
   111   assert(_oop_null < C->unique(), "should be created already");
   112   add_node(oop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   114   if (UseCompressedOops) {
   115     Node* noop_null = igvn->zerocon(T_NARROWOOP);
   116     _noop_null = noop_null->_idx;
   117     assert(_noop_null < C->unique(), "should be created already");
   118     add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   119   }
   120 }
   122 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
   123   PointsToNode *f = ptnode_adr(from_i);
   124   PointsToNode *t = ptnode_adr(to_i);
   126   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   127   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
   128   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
   129   add_edge(f, to_i, PointsToNode::PointsToEdge);
   130 }
   132 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
   133   PointsToNode *f = ptnode_adr(from_i);
   134   PointsToNode *t = ptnode_adr(to_i);
   136   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   137   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
   138   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
   139   // don't add a self-referential edge, this can occur during removal of
   140   // deferred edges
   141   if (from_i != to_i)
   142     add_edge(f, to_i, PointsToNode::DeferredEdge);
   143 }
   145 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
   146   const Type *adr_type = phase->type(adr);
   147   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
   148       adr->in(AddPNode::Address)->is_Proj() &&
   149       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
   150     // We are computing a raw address for a store captured by an Initialize
   151     // compute an appropriate address type. AddP cases #3 and #5 (see below).
   152     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
   153     assert(offs != Type::OffsetBot ||
   154            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
   155            "offset must be a constant or it is initialization of array");
   156     return offs;
   157   }
   158   const TypePtr *t_ptr = adr_type->isa_ptr();
   159   assert(t_ptr != NULL, "must be a pointer type");
   160   return t_ptr->offset();
   161 }
   163 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
   164   PointsToNode *f = ptnode_adr(from_i);
   165   PointsToNode *t = ptnode_adr(to_i);
   167   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   168   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
   169   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
   170   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
   171   t->set_offset(offset);
   173   add_edge(f, to_i, PointsToNode::FieldEdge);
   174 }
   176 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
   177   PointsToNode *npt = ptnode_adr(ni);
   178   PointsToNode::EscapeState old_es = npt->escape_state();
   179   if (es > old_es)
   180     npt->set_escape_state(es);
   181 }
   183 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
   184                                PointsToNode::EscapeState es, bool done) {
   185   PointsToNode* ptadr = ptnode_adr(n->_idx);
   186   ptadr->_node = n;
   187   ptadr->set_node_type(nt);
   189   // inline set_escape_state(idx, es);
   190   PointsToNode::EscapeState old_es = ptadr->escape_state();
   191   if (es > old_es)
   192     ptadr->set_escape_state(es);
   194   if (done)
   195     _processed.set(n->_idx);
   196 }
   198 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
   199   uint idx = n->_idx;
   200   PointsToNode::EscapeState es;
   202   // If we are still collecting or there were no non-escaping allocations
   203   // we don't know the answer yet
   204   if (_collecting)
   205     return PointsToNode::UnknownEscape;
   207   // if the node was created after the escape computation, return
   208   // UnknownEscape
   209   if (idx >= nodes_size())
   210     return PointsToNode::UnknownEscape;
   212   es = ptnode_adr(idx)->escape_state();
   214   // if we have already computed a value, return it
   215   if (es != PointsToNode::UnknownEscape &&
   216       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
   217     return es;
   219   // PointsTo() calls n->uncast() which can return a new ideal node.
   220   if (n->uncast()->_idx >= nodes_size())
   221     return PointsToNode::UnknownEscape;
   223   PointsToNode::EscapeState orig_es = es;
   225   // compute max escape state of anything this node could point to
   226   for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
   227     uint pt = i.elem;
   228     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
   229     if (pes > es)
   230       es = pes;
   231   }
   232   if (orig_es != es) {
   233     // cache the computed escape state
   234     assert(es != PointsToNode::UnknownEscape, "should have computed an escape state");
   235     ptnode_adr(idx)->set_escape_state(es);
   236   } // orig_es could be PointsToNode::UnknownEscape
   237   return es;
   238 }
   240 VectorSet* ConnectionGraph::PointsTo(Node * n) {
   241   pt_ptset.Reset();
   242   pt_visited.Reset();
   243   pt_worklist.clear();
   245 #ifdef ASSERT
   246   Node *orig_n = n;
   247 #endif
   249   n = n->uncast();
   250   PointsToNode* npt = ptnode_adr(n->_idx);
   252   // If we have a JavaObject, return just that object
   253   if (npt->node_type() == PointsToNode::JavaObject) {
   254     pt_ptset.set(n->_idx);
   255     return &pt_ptset;
   256   }
   257 #ifdef ASSERT
   258   if (npt->_node == NULL) {
   259     if (orig_n != n)
   260       orig_n->dump();
   261     n->dump();
   262     assert(npt->_node != NULL, "unregistered node");
   263   }
   264 #endif
   265   pt_worklist.push(n->_idx);
   266   while(pt_worklist.length() > 0) {
   267     int ni = pt_worklist.pop();
   268     if (pt_visited.test_set(ni))
   269       continue;
   271     PointsToNode* pn = ptnode_adr(ni);
   272     // ensure that all inputs of a Phi have been processed
   273     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
   275     int edges_processed = 0;
   276     uint e_cnt = pn->edge_count();
   277     for (uint e = 0; e < e_cnt; e++) {
   278       uint etgt = pn->edge_target(e);
   279       PointsToNode::EdgeType et = pn->edge_type(e);
   280       if (et == PointsToNode::PointsToEdge) {
   281         pt_ptset.set(etgt);
   282         edges_processed++;
   283       } else if (et == PointsToNode::DeferredEdge) {
   284         pt_worklist.push(etgt);
   285         edges_processed++;
   286       } else {
   287         assert(false,"neither PointsToEdge or DeferredEdge");
   288       }
   289     }
   290     if (edges_processed == 0) {
   291       // no deferred or pointsto edges found.  Assume the value was set
   292       // outside this method.  Add the phantom object to the pointsto set.
   293       pt_ptset.set(_phantom_object);
   294     }
   295   }
   296   return &pt_ptset;
   297 }
   299 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
   300   // This method is most expensive during ConnectionGraph construction.
   301   // Reuse vectorSet and an additional growable array for deferred edges.
   302   deferred_edges->clear();
   303   visited->Reset();
   305   visited->set(ni);
   306   PointsToNode *ptn = ptnode_adr(ni);
   308   // Mark current edges as visited and move deferred edges to separate array.
   309   for (uint i = 0; i < ptn->edge_count(); ) {
   310     uint t = ptn->edge_target(i);
   311 #ifdef ASSERT
   312     assert(!visited->test_set(t), "expecting no duplications");
   313 #else
   314     visited->set(t);
   315 #endif
   316     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
   317       ptn->remove_edge(t, PointsToNode::DeferredEdge);
   318       deferred_edges->append(t);
   319     } else {
   320       i++;
   321     }
   322   }
   323   for (int next = 0; next < deferred_edges->length(); ++next) {
   324     uint t = deferred_edges->at(next);
   325     PointsToNode *ptt = ptnode_adr(t);
   326     uint e_cnt = ptt->edge_count();
   327     for (uint e = 0; e < e_cnt; e++) {
   328       uint etgt = ptt->edge_target(e);
   329       if (visited->test_set(etgt))
   330         continue;
   332       PointsToNode::EdgeType et = ptt->edge_type(e);
   333       if (et == PointsToNode::PointsToEdge) {
   334         add_pointsto_edge(ni, etgt);
   335         if(etgt == _phantom_object) {
   336           // Special case - field set outside (globally escaping).
   337           ptn->set_escape_state(PointsToNode::GlobalEscape);
   338         }
   339       } else if (et == PointsToNode::DeferredEdge) {
   340         deferred_edges->append(etgt);
   341       } else {
   342         assert(false,"invalid connection graph");
   343       }
   344     }
   345   }
   346 }
   349 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
   350 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
   351 //  a pointsto edge is added if it is a JavaObject
   353 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
   354   PointsToNode* an = ptnode_adr(adr_i);
   355   PointsToNode* to = ptnode_adr(to_i);
   356   bool deferred = (to->node_type() == PointsToNode::LocalVar);
   358   for (uint fe = 0; fe < an->edge_count(); fe++) {
   359     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   360     int fi = an->edge_target(fe);
   361     PointsToNode* pf = ptnode_adr(fi);
   362     int po = pf->offset();
   363     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   364       if (deferred)
   365         add_deferred_edge(fi, to_i);
   366       else
   367         add_pointsto_edge(fi, to_i);
   368     }
   369   }
   370 }
   372 // Add a deferred  edge from node given by "from_i" to any field of adr_i
   373 // whose offset matches "offset".
   374 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
   375   PointsToNode* an = ptnode_adr(adr_i);
   376   for (uint fe = 0; fe < an->edge_count(); fe++) {
   377     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   378     int fi = an->edge_target(fe);
   379     PointsToNode* pf = ptnode_adr(fi);
   380     int po = pf->offset();
   381     if (pf->edge_count() == 0) {
   382       // we have not seen any stores to this field, assume it was set outside this method
   383       add_pointsto_edge(fi, _phantom_object);
   384     }
   385     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   386       add_deferred_edge(from_i, fi);
   387     }
   388   }
   389 }
   391 // Helper functions
   393 static Node* get_addp_base(Node *addp) {
   394   assert(addp->is_AddP(), "must be AddP");
   395   //
   396   // AddP cases for Base and Address inputs:
   397   // case #1. Direct object's field reference:
   398   //     Allocate
   399   //       |
   400   //     Proj #5 ( oop result )
   401   //       |
   402   //     CheckCastPP (cast to instance type)
   403   //      | |
   404   //     AddP  ( base == address )
   405   //
   406   // case #2. Indirect object's field reference:
   407   //      Phi
   408   //       |
   409   //     CastPP (cast to instance type)
   410   //      | |
   411   //     AddP  ( base == address )
   412   //
   413   // case #3. Raw object's field reference for Initialize node:
   414   //      Allocate
   415   //        |
   416   //      Proj #5 ( oop result )
   417   //  top   |
   418   //     \  |
   419   //     AddP  ( base == top )
   420   //
   421   // case #4. Array's element reference:
   422   //   {CheckCastPP | CastPP}
   423   //     |  | |
   424   //     |  AddP ( array's element offset )
   425   //     |  |
   426   //     AddP ( array's offset )
   427   //
   428   // case #5. Raw object's field reference for arraycopy stub call:
   429   //          The inline_native_clone() case when the arraycopy stub is called
   430   //          after the allocation before Initialize and CheckCastPP nodes.
   431   //      Allocate
   432   //        |
   433   //      Proj #5 ( oop result )
   434   //       | |
   435   //       AddP  ( base == address )
   436   //
   437   // case #6. Constant Pool, ThreadLocal, CastX2P or
   438   //          Raw object's field reference:
   439   //      {ConP, ThreadLocal, CastX2P, raw Load}
   440   //  top   |
   441   //     \  |
   442   //     AddP  ( base == top )
   443   //
   444   // case #7. Klass's field reference.
   445   //      LoadKlass
   446   //       | |
   447   //       AddP  ( base == address )
   448   //
   449   // case #8. narrow Klass's field reference.
   450   //      LoadNKlass
   451   //       |
   452   //      DecodeN
   453   //       | |
   454   //       AddP  ( base == address )
   455   //
   456   Node *base = addp->in(AddPNode::Base)->uncast();
   457   if (base->is_top()) { // The AddP case #3 and #6.
   458     base = addp->in(AddPNode::Address)->uncast();
   459     while (base->is_AddP()) {
   460       // Case #6 (unsafe access) may have several chained AddP nodes.
   461       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
   462       base = base->in(AddPNode::Address)->uncast();
   463     }
   464     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
   465            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
   466            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
   467            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
   468   }
   469   return base;
   470 }
   472 static Node* find_second_addp(Node* addp, Node* n) {
   473   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
   475   Node* addp2 = addp->raw_out(0);
   476   if (addp->outcnt() == 1 && addp2->is_AddP() &&
   477       addp2->in(AddPNode::Base) == n &&
   478       addp2->in(AddPNode::Address) == addp) {
   480     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
   481     //
   482     // Find array's offset to push it on worklist first and
   483     // as result process an array's element offset first (pushed second)
   484     // to avoid CastPP for the array's offset.
   485     // Otherwise the inserted CastPP (LocalVar) will point to what
   486     // the AddP (Field) points to. Which would be wrong since
   487     // the algorithm expects the CastPP has the same point as
   488     // as AddP's base CheckCastPP (LocalVar).
   489     //
   490     //    ArrayAllocation
   491     //     |
   492     //    CheckCastPP
   493     //     |
   494     //    memProj (from ArrayAllocation CheckCastPP)
   495     //     |  ||
   496     //     |  ||   Int (element index)
   497     //     |  ||    |   ConI (log(element size))
   498     //     |  ||    |   /
   499     //     |  ||   LShift
   500     //     |  ||  /
   501     //     |  AddP (array's element offset)
   502     //     |  |
   503     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
   504     //     | / /
   505     //     AddP (array's offset)
   506     //      |
   507     //     Load/Store (memory operation on array's element)
   508     //
   509     return addp2;
   510   }
   511   return NULL;
   512 }
   514 //
   515 // Adjust the type and inputs of an AddP which computes the
   516 // address of a field of an instance
   517 //
   518 bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
   519   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
   520   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
   521   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
   522   if (t == NULL) {
   523     // We are computing a raw address for a store captured by an Initialize
   524     // compute an appropriate address type (cases #3 and #5).
   525     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
   526     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
   527     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
   528     assert(offs != Type::OffsetBot, "offset must be a constant");
   529     t = base_t->add_offset(offs)->is_oopptr();
   530   }
   531   int inst_id =  base_t->instance_id();
   532   assert(!t->is_known_instance() || t->instance_id() == inst_id,
   533                              "old type must be non-instance or match new type");
   535   // The type 't' could be subclass of 'base_t'.
   536   // As result t->offset() could be large then base_t's size and it will
   537   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
   538   // constructor verifies correctness of the offset.
   539   //
   540   // It could happened on subclass's branch (from the type profiling
   541   // inlining) which was not eliminated during parsing since the exactness
   542   // of the allocation type was not propagated to the subclass type check.
   543   //
   544   // Or the type 't' could be not related to 'base_t' at all.
   545   // It could happened when CHA type is different from MDO type on a dead path
   546   // (for example, from instanceof check) which is not collapsed during parsing.
   547   //
   548   // Do nothing for such AddP node and don't process its users since
   549   // this code branch will go away.
   550   //
   551   if (!t->is_known_instance() &&
   552       !base_t->klass()->is_subtype_of(t->klass())) {
   553      return false; // bail out
   554   }
   556   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
   557   // Do NOT remove the next line: ensure a new alias index is allocated
   558   // for the instance type. Note: C++ will not remove it since the call
   559   // has side effect.
   560   int alias_idx = _compile->get_alias_index(tinst);
   561   igvn->set_type(addp, tinst);
   562   // record the allocation in the node map
   563   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
   564   set_map(addp->_idx, get_map(base->_idx));
   566   // Set addp's Base and Address to 'base'.
   567   Node *abase = addp->in(AddPNode::Base);
   568   Node *adr   = addp->in(AddPNode::Address);
   569   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
   570       adr->in(0)->_idx == (uint)inst_id) {
   571     // Skip AddP cases #3 and #5.
   572   } else {
   573     assert(!abase->is_top(), "sanity"); // AddP case #3
   574     if (abase != base) {
   575       igvn->hash_delete(addp);
   576       addp->set_req(AddPNode::Base, base);
   577       if (abase == adr) {
   578         addp->set_req(AddPNode::Address, base);
   579       } else {
   580         // AddP case #4 (adr is array's element offset AddP node)
   581 #ifdef ASSERT
   582         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
   583         assert(adr->is_AddP() && atype != NULL &&
   584                atype->instance_id() == inst_id, "array's element offset should be processed first");
   585 #endif
   586       }
   587       igvn->hash_insert(addp);
   588     }
   589   }
   590   // Put on IGVN worklist since at least addp's type was changed above.
   591   record_for_optimizer(addp);
   592   return true;
   593 }
   595 //
   596 // Create a new version of orig_phi if necessary. Returns either the newly
   597 // created phi or an existing phi.  Sets create_new to indicate whether a new
   598 // phi was created.  Cache the last newly created phi in the node map.
   599 //
   600 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
   601   Compile *C = _compile;
   602   new_created = false;
   603   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
   604   // nothing to do if orig_phi is bottom memory or matches alias_idx
   605   if (phi_alias_idx == alias_idx) {
   606     return orig_phi;
   607   }
   608   // Have we recently created a Phi for this alias index?
   609   PhiNode *result = get_map_phi(orig_phi->_idx);
   610   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
   611     return result;
   612   }
   613   // Previous check may fail when the same wide memory Phi was split into Phis
   614   // for different memory slices. Search all Phis for this region.
   615   if (result != NULL) {
   616     Node* region = orig_phi->in(0);
   617     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
   618       Node* phi = region->fast_out(i);
   619       if (phi->is_Phi() &&
   620           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
   621         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
   622         return phi->as_Phi();
   623       }
   624     }
   625   }
   626   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
   627     if (C->do_escape_analysis() == true && !C->failing()) {
   628       // Retry compilation without escape analysis.
   629       // If this is the first failure, the sentinel string will "stick"
   630       // to the Compile object, and the C2Compiler will see it and retry.
   631       C->record_failure(C2Compiler::retry_no_escape_analysis());
   632     }
   633     return NULL;
   634   }
   635   orig_phi_worklist.append_if_missing(orig_phi);
   636   const TypePtr *atype = C->get_adr_type(alias_idx);
   637   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
   638   C->copy_node_notes_to(result, orig_phi);
   639   igvn->set_type(result, result->bottom_type());
   640   record_for_optimizer(result);
   642   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
   643   assert(pn == NULL || pn == orig_phi, "wrong node");
   644   set_map(orig_phi->_idx, result);
   645   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
   647   new_created = true;
   648   return result;
   649 }
   651 //
   652 // Return a new version of Memory Phi "orig_phi" with the inputs having the
   653 // specified alias index.
   654 //
   655 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
   657   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
   658   Compile *C = _compile;
   659   bool new_phi_created;
   660   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
   661   if (!new_phi_created) {
   662     return result;
   663   }
   665   GrowableArray<PhiNode *>  phi_list;
   666   GrowableArray<uint>  cur_input;
   668   PhiNode *phi = orig_phi;
   669   uint idx = 1;
   670   bool finished = false;
   671   while(!finished) {
   672     while (idx < phi->req()) {
   673       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
   674       if (mem != NULL && mem->is_Phi()) {
   675         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
   676         if (new_phi_created) {
   677           // found an phi for which we created a new split, push current one on worklist and begin
   678           // processing new one
   679           phi_list.push(phi);
   680           cur_input.push(idx);
   681           phi = mem->as_Phi();
   682           result = newphi;
   683           idx = 1;
   684           continue;
   685         } else {
   686           mem = newphi;
   687         }
   688       }
   689       if (C->failing()) {
   690         return NULL;
   691       }
   692       result->set_req(idx++, mem);
   693     }
   694 #ifdef ASSERT
   695     // verify that the new Phi has an input for each input of the original
   696     assert( phi->req() == result->req(), "must have same number of inputs.");
   697     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
   698 #endif
   699     // Check if all new phi's inputs have specified alias index.
   700     // Otherwise use old phi.
   701     for (uint i = 1; i < phi->req(); i++) {
   702       Node* in = result->in(i);
   703       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
   704     }
   705     // we have finished processing a Phi, see if there are any more to do
   706     finished = (phi_list.length() == 0 );
   707     if (!finished) {
   708       phi = phi_list.pop();
   709       idx = cur_input.pop();
   710       PhiNode *prev_result = get_map_phi(phi->_idx);
   711       prev_result->set_req(idx++, result);
   712       result = prev_result;
   713     }
   714   }
   715   return result;
   716 }
   719 //
   720 // The next methods are derived from methods in MemNode.
   721 //
   722 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
   723   Node *mem = mmem;
   724   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
   725   // means an array I have not precisely typed yet.  Do not do any
   726   // alias stuff with it any time soon.
   727   if( toop->base() != Type::AnyPtr &&
   728       !(toop->klass() != NULL &&
   729         toop->klass()->is_java_lang_Object() &&
   730         toop->offset() == Type::OffsetBot) ) {
   731     mem = mmem->memory_at(alias_idx);
   732     // Update input if it is progress over what we have now
   733   }
   734   return mem;
   735 }
   737 //
   738 // Move memory users to their memory slices.
   739 //
   740 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
   741   Compile* C = _compile;
   743   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
   744   assert(tp != NULL, "ptr type");
   745   int alias_idx = C->get_alias_index(tp);
   746   int general_idx = C->get_general_index(alias_idx);
   748   // Move users first
   749   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
   750     Node* use = n->fast_out(i);
   751     if (use->is_MergeMem()) {
   752       MergeMemNode* mmem = use->as_MergeMem();
   753       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
   754       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
   755         continue; // Nothing to do
   756       }
   757       // Replace previous general reference to mem node.
   758       uint orig_uniq = C->unique();
   759       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   760       assert(orig_uniq == C->unique(), "no new nodes");
   761       mmem->set_memory_at(general_idx, m);
   762       --imax;
   763       --i;
   764     } else if (use->is_MemBar()) {
   765       assert(!use->is_Initialize(), "initializing stores should not be moved");
   766       if (use->req() > MemBarNode::Precedent &&
   767           use->in(MemBarNode::Precedent) == n) {
   768         // Don't move related membars.
   769         record_for_optimizer(use);
   770         continue;
   771       }
   772       tp = use->as_MemBar()->adr_type()->isa_ptr();
   773       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
   774           alias_idx == general_idx) {
   775         continue; // Nothing to do
   776       }
   777       // Move to general memory slice.
   778       uint orig_uniq = C->unique();
   779       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   780       assert(orig_uniq == C->unique(), "no new nodes");
   781       igvn->hash_delete(use);
   782       imax -= use->replace_edge(n, m);
   783       igvn->hash_insert(use);
   784       record_for_optimizer(use);
   785       --i;
   786 #ifdef ASSERT
   787     } else if (use->is_Mem()) {
   788       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
   789         // Don't move related cardmark.
   790         continue;
   791       }
   792       // Memory nodes should have new memory input.
   793       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
   794       assert(tp != NULL, "ptr type");
   795       int idx = C->get_alias_index(tp);
   796       assert(get_map(use->_idx) != NULL || idx == alias_idx,
   797              "Following memory nodes should have new memory input or be on the same memory slice");
   798     } else if (use->is_Phi()) {
   799       // Phi nodes should be split and moved already.
   800       tp = use->as_Phi()->adr_type()->isa_ptr();
   801       assert(tp != NULL, "ptr type");
   802       int idx = C->get_alias_index(tp);
   803       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
   804     } else {
   805       use->dump();
   806       assert(false, "should not be here");
   807 #endif
   808     }
   809   }
   810 }
   812 //
   813 // Search memory chain of "mem" to find a MemNode whose address
   814 // is the specified alias index.
   815 //
   816 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
   817   if (orig_mem == NULL)
   818     return orig_mem;
   819   Compile* C = phase->C;
   820   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
   821   bool is_instance = (toop != NULL) && toop->is_known_instance();
   822   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   823   Node *prev = NULL;
   824   Node *result = orig_mem;
   825   while (prev != result) {
   826     prev = result;
   827     if (result == start_mem)
   828       break;  // hit one of our sentinels
   829     if (result->is_Mem()) {
   830       const Type *at = phase->type(result->in(MemNode::Address));
   831       if (at == Type::TOP)
   832         break; // Dead
   833       assert (at->isa_ptr() != NULL, "pointer type required.");
   834       int idx = C->get_alias_index(at->is_ptr());
   835       if (idx == alias_idx)
   836         break; // Found
   837       if (!is_instance && (at->isa_oopptr() == NULL ||
   838                            !at->is_oopptr()->is_known_instance())) {
   839         break; // Do not skip store to general memory slice.
   840       }
   841       result = result->in(MemNode::Memory);
   842     }
   843     if (!is_instance)
   844       continue;  // don't search further for non-instance types
   845     // skip over a call which does not affect this memory slice
   846     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
   847       Node *proj_in = result->in(0);
   848       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
   849         break;  // hit one of our sentinels
   850       } else if (proj_in->is_Call()) {
   851         CallNode *call = proj_in->as_Call();
   852         if (!call->may_modify(toop, phase)) {
   853           result = call->in(TypeFunc::Memory);
   854         }
   855       } else if (proj_in->is_Initialize()) {
   856         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
   857         // Stop if this is the initialization for the object instance which
   858         // which contains this memory slice, otherwise skip over it.
   859         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
   860           result = proj_in->in(TypeFunc::Memory);
   861         }
   862       } else if (proj_in->is_MemBar()) {
   863         result = proj_in->in(TypeFunc::Memory);
   864       }
   865     } else if (result->is_MergeMem()) {
   866       MergeMemNode *mmem = result->as_MergeMem();
   867       result = step_through_mergemem(mmem, alias_idx, toop);
   868       if (result == mmem->base_memory()) {
   869         // Didn't find instance memory, search through general slice recursively.
   870         result = mmem->memory_at(C->get_general_index(alias_idx));
   871         result = find_inst_mem(result, alias_idx, orig_phis, phase);
   872         if (C->failing()) {
   873           return NULL;
   874         }
   875         mmem->set_memory_at(alias_idx, result);
   876       }
   877     } else if (result->is_Phi() &&
   878                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
   879       Node *un = result->as_Phi()->unique_input(phase);
   880       if (un != NULL) {
   881         orig_phis.append_if_missing(result->as_Phi());
   882         result = un;
   883       } else {
   884         break;
   885       }
   886     } else if (result->is_ClearArray()) {
   887       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
   888         // Can not bypass initialization of the instance
   889         // we are looking for.
   890         break;
   891       }
   892       // Otherwise skip it (the call updated 'result' value).
   893     } else if (result->Opcode() == Op_SCMemProj) {
   894       assert(result->in(0)->is_LoadStore(), "sanity");
   895       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
   896       if (at != Type::TOP) {
   897         assert (at->isa_ptr() != NULL, "pointer type required.");
   898         int idx = C->get_alias_index(at->is_ptr());
   899         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
   900         break;
   901       }
   902       result = result->in(0)->in(MemNode::Memory);
   903     }
   904   }
   905   if (result->is_Phi()) {
   906     PhiNode *mphi = result->as_Phi();
   907     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
   908     const TypePtr *t = mphi->adr_type();
   909     if (!is_instance) {
   910       // Push all non-instance Phis on the orig_phis worklist to update inputs
   911       // during Phase 4 if needed.
   912       orig_phis.append_if_missing(mphi);
   913     } else if (C->get_alias_index(t) != alias_idx) {
   914       // Create a new Phi with the specified alias index type.
   915       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
   916     }
   917   }
   918   // the result is either MemNode, PhiNode, InitializeNode.
   919   return result;
   920 }
   922 //
   923 //  Convert the types of unescaped object to instance types where possible,
   924 //  propagate the new type information through the graph, and update memory
   925 //  edges and MergeMem inputs to reflect the new type.
   926 //
   927 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
   928 //  The processing is done in 4 phases:
   929 //
   930 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
   931 //            types for the CheckCastPP for allocations where possible.
   932 //            Propagate the the new types through users as follows:
   933 //               casts and Phi:  push users on alloc_worklist
   934 //               AddP:  cast Base and Address inputs to the instance type
   935 //                      push any AddP users on alloc_worklist and push any memnode
   936 //                      users onto memnode_worklist.
   937 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
   938 //            search the Memory chain for a store with the appropriate type
   939 //            address type.  If a Phi is found, create a new version with
   940 //            the appropriate memory slices from each of the Phi inputs.
   941 //            For stores, process the users as follows:
   942 //               MemNode:  push on memnode_worklist
   943 //               MergeMem: push on mergemem_worklist
   944 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
   945 //            moving the first node encountered of each  instance type to the
   946 //            the input corresponding to its alias index.
   947 //            appropriate memory slice.
   948 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
   949 //
   950 // In the following example, the CheckCastPP nodes are the cast of allocation
   951 // results and the allocation of node 29 is unescaped and eligible to be an
   952 // instance type.
   953 //
   954 // We start with:
   955 //
   956 //     7 Parm #memory
   957 //    10  ConI  "12"
   958 //    19  CheckCastPP   "Foo"
   959 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   960 //    29  CheckCastPP   "Foo"
   961 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
   962 //
   963 //    40  StoreP  25   7  20   ... alias_index=4
   964 //    50  StoreP  35  40  30   ... alias_index=4
   965 //    60  StoreP  45  50  20   ... alias_index=4
   966 //    70  LoadP    _  60  30   ... alias_index=4
   967 //    80  Phi     75  50  60   Memory alias_index=4
   968 //    90  LoadP    _  80  30   ... alias_index=4
   969 //   100  LoadP    _  80  20   ... alias_index=4
   970 //
   971 //
   972 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
   973 // and creating a new alias index for node 30.  This gives:
   974 //
   975 //     7 Parm #memory
   976 //    10  ConI  "12"
   977 //    19  CheckCastPP   "Foo"
   978 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   979 //    29  CheckCastPP   "Foo"  iid=24
   980 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
   981 //
   982 //    40  StoreP  25   7  20   ... alias_index=4
   983 //    50  StoreP  35  40  30   ... alias_index=6
   984 //    60  StoreP  45  50  20   ... alias_index=4
   985 //    70  LoadP    _  60  30   ... alias_index=6
   986 //    80  Phi     75  50  60   Memory alias_index=4
   987 //    90  LoadP    _  80  30   ... alias_index=6
   988 //   100  LoadP    _  80  20   ... alias_index=4
   989 //
   990 // In phase 2, new memory inputs are computed for the loads and stores,
   991 // And a new version of the phi is created.  In phase 4, the inputs to
   992 // node 80 are updated and then the memory nodes are updated with the
   993 // values computed in phase 2.  This results in:
   994 //
   995 //     7 Parm #memory
   996 //    10  ConI  "12"
   997 //    19  CheckCastPP   "Foo"
   998 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   999 //    29  CheckCastPP   "Foo"  iid=24
  1000 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
  1001 //
  1002 //    40  StoreP  25  7   20   ... alias_index=4
  1003 //    50  StoreP  35  7   30   ... alias_index=6
  1004 //    60  StoreP  45  40  20   ... alias_index=4
  1005 //    70  LoadP    _  50  30   ... alias_index=6
  1006 //    80  Phi     75  40  60   Memory alias_index=4
  1007 //   120  Phi     75  50  50   Memory alias_index=6
  1008 //    90  LoadP    _ 120  30   ... alias_index=6
  1009 //   100  LoadP    _  80  20   ... alias_index=4
  1010 //
  1011 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
  1012   GrowableArray<Node *>  memnode_worklist;
  1013   GrowableArray<PhiNode *>  orig_phis;
  1015   PhaseIterGVN  *igvn = _igvn;
  1016   uint new_index_start = (uint) _compile->num_alias_types();
  1017   Arena* arena = Thread::current()->resource_area();
  1018   VectorSet visited(arena);
  1021   //  Phase 1:  Process possible allocations from alloc_worklist.
  1022   //  Create instance types for the CheckCastPP for allocations where possible.
  1023   //
  1024   // (Note: don't forget to change the order of the second AddP node on
  1025   //  the alloc_worklist if the order of the worklist processing is changed,
  1026   //  see the comment in find_second_addp().)
  1027   //
  1028   while (alloc_worklist.length() != 0) {
  1029     Node *n = alloc_worklist.pop();
  1030     uint ni = n->_idx;
  1031     const TypeOopPtr* tinst = NULL;
  1032     if (n->is_Call()) {
  1033       CallNode *alloc = n->as_Call();
  1034       // copy escape information to call node
  1035       PointsToNode* ptn = ptnode_adr(alloc->_idx);
  1036       PointsToNode::EscapeState es = escape_state(alloc);
  1037       // We have an allocation or call which returns a Java object,
  1038       // see if it is unescaped.
  1039       if (es != PointsToNode::NoEscape || !ptn->_scalar_replaceable)
  1040         continue;
  1042       // Find CheckCastPP for the allocate or for the return value of a call
  1043       n = alloc->result_cast();
  1044       if (n == NULL) {            // No uses except Initialize node
  1045         if (alloc->is_Allocate()) {
  1046           // Set the scalar_replaceable flag for allocation
  1047           // so it could be eliminated if it has no uses.
  1048           alloc->as_Allocate()->_is_scalar_replaceable = true;
  1050         continue;
  1052       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
  1053         assert(!alloc->is_Allocate(), "allocation should have unique type");
  1054         continue;
  1057       // The inline code for Object.clone() casts the allocation result to
  1058       // java.lang.Object and then to the actual type of the allocated
  1059       // object. Detect this case and use the second cast.
  1060       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
  1061       // the allocation result is cast to java.lang.Object and then
  1062       // to the actual Array type.
  1063       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
  1064           && (alloc->is_AllocateArray() ||
  1065               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
  1066         Node *cast2 = NULL;
  1067         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1068           Node *use = n->fast_out(i);
  1069           if (use->is_CheckCastPP()) {
  1070             cast2 = use;
  1071             break;
  1074         if (cast2 != NULL) {
  1075           n = cast2;
  1076         } else {
  1077           // Non-scalar replaceable if the allocation type is unknown statically
  1078           // (reflection allocation), the object can't be restored during
  1079           // deoptimization without precise type.
  1080           continue;
  1083       if (alloc->is_Allocate()) {
  1084         // Set the scalar_replaceable flag for allocation
  1085         // so it could be eliminated.
  1086         alloc->as_Allocate()->_is_scalar_replaceable = true;
  1088       set_escape_state(n->_idx, es);
  1089       // in order for an object to be scalar-replaceable, it must be:
  1090       //   - a direct allocation (not a call returning an object)
  1091       //   - non-escaping
  1092       //   - eligible to be a unique type
  1093       //   - not determined to be ineligible by escape analysis
  1094       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
  1095              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
  1096       set_map(alloc->_idx, n);
  1097       set_map(n->_idx, alloc);
  1098       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
  1099       if (t == NULL)
  1100         continue;  // not a TypeInstPtr
  1101       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
  1102       igvn->hash_delete(n);
  1103       igvn->set_type(n,  tinst);
  1104       n->raise_bottom_type(tinst);
  1105       igvn->hash_insert(n);
  1106       record_for_optimizer(n);
  1107       if (alloc->is_Allocate() && ptn->_scalar_replaceable &&
  1108           (t->isa_instptr() || t->isa_aryptr())) {
  1110         // First, put on the worklist all Field edges from Connection Graph
  1111         // which is more accurate then putting immediate users from Ideal Graph.
  1112         for (uint e = 0; e < ptn->edge_count(); e++) {
  1113           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
  1114           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
  1115                  "only AddP nodes are Field edges in CG");
  1116           if (use->outcnt() > 0) { // Don't process dead nodes
  1117             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
  1118             if (addp2 != NULL) {
  1119               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1120               alloc_worklist.append_if_missing(addp2);
  1122             alloc_worklist.append_if_missing(use);
  1126         // An allocation may have an Initialize which has raw stores. Scan
  1127         // the users of the raw allocation result and push AddP users
  1128         // on alloc_worklist.
  1129         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
  1130         assert (raw_result != NULL, "must have an allocation result");
  1131         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
  1132           Node *use = raw_result->fast_out(i);
  1133           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
  1134             Node* addp2 = find_second_addp(use, raw_result);
  1135             if (addp2 != NULL) {
  1136               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1137               alloc_worklist.append_if_missing(addp2);
  1139             alloc_worklist.append_if_missing(use);
  1140           } else if (use->is_MemBar()) {
  1141             memnode_worklist.append_if_missing(use);
  1145     } else if (n->is_AddP()) {
  1146       VectorSet* ptset = PointsTo(get_addp_base(n));
  1147       assert(ptset->Size() == 1, "AddP address is unique");
  1148       uint elem = ptset->getelem(); // Allocation node's index
  1149       if (elem == _phantom_object) {
  1150         assert(false, "escaped allocation");
  1151         continue; // Assume the value was set outside this method.
  1153       Node *base = get_map(elem);  // CheckCastPP node
  1154       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
  1155       tinst = igvn->type(base)->isa_oopptr();
  1156     } else if (n->is_Phi() ||
  1157                n->is_CheckCastPP() ||
  1158                n->is_EncodeP() ||
  1159                n->is_DecodeN() ||
  1160                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
  1161       if (visited.test_set(n->_idx)) {
  1162         assert(n->is_Phi(), "loops only through Phi's");
  1163         continue;  // already processed
  1165       VectorSet* ptset = PointsTo(n);
  1166       if (ptset->Size() == 1) {
  1167         uint elem = ptset->getelem(); // Allocation node's index
  1168         if (elem == _phantom_object) {
  1169           assert(false, "escaped allocation");
  1170           continue; // Assume the value was set outside this method.
  1172         Node *val = get_map(elem);   // CheckCastPP node
  1173         TypeNode *tn = n->as_Type();
  1174         tinst = igvn->type(val)->isa_oopptr();
  1175         assert(tinst != NULL && tinst->is_known_instance() &&
  1176                (uint)tinst->instance_id() == elem , "instance type expected.");
  1178         const Type *tn_type = igvn->type(tn);
  1179         const TypeOopPtr *tn_t;
  1180         if (tn_type->isa_narrowoop()) {
  1181           tn_t = tn_type->make_ptr()->isa_oopptr();
  1182         } else {
  1183           tn_t = tn_type->isa_oopptr();
  1186         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
  1187           if (tn_type->isa_narrowoop()) {
  1188             tn_type = tinst->make_narrowoop();
  1189           } else {
  1190             tn_type = tinst;
  1192           igvn->hash_delete(tn);
  1193           igvn->set_type(tn, tn_type);
  1194           tn->set_type(tn_type);
  1195           igvn->hash_insert(tn);
  1196           record_for_optimizer(n);
  1197         } else {
  1198           assert(tn_type == TypePtr::NULL_PTR ||
  1199                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
  1200                  "unexpected type");
  1201           continue; // Skip dead path with different type
  1204     } else {
  1205       debug_only(n->dump();)
  1206       assert(false, "EA: unexpected node");
  1207       continue;
  1209     // push allocation's users on appropriate worklist
  1210     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1211       Node *use = n->fast_out(i);
  1212       if(use->is_Mem() && use->in(MemNode::Address) == n) {
  1213         // Load/store to instance's field
  1214         memnode_worklist.append_if_missing(use);
  1215       } else if (use->is_MemBar()) {
  1216         memnode_worklist.append_if_missing(use);
  1217       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
  1218         Node* addp2 = find_second_addp(use, n);
  1219         if (addp2 != NULL) {
  1220           alloc_worklist.append_if_missing(addp2);
  1222         alloc_worklist.append_if_missing(use);
  1223       } else if (use->is_Phi() ||
  1224                  use->is_CheckCastPP() ||
  1225                  use->is_EncodeP() ||
  1226                  use->is_DecodeN() ||
  1227                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
  1228         alloc_worklist.append_if_missing(use);
  1229 #ifdef ASSERT
  1230       } else if (use->is_Mem()) {
  1231         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
  1232       } else if (use->is_MergeMem()) {
  1233         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1234       } else if (use->is_SafePoint()) {
  1235         // Look for MergeMem nodes for calls which reference unique allocation
  1236         // (through CheckCastPP nodes) even for debug info.
  1237         Node* m = use->in(TypeFunc::Memory);
  1238         if (m->is_MergeMem()) {
  1239           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1241       } else {
  1242         uint op = use->Opcode();
  1243         if (!(op == Op_CmpP || op == Op_Conv2B ||
  1244               op == Op_CastP2X || op == Op_StoreCM ||
  1245               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
  1246               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1247           n->dump();
  1248           use->dump();
  1249           assert(false, "EA: missing allocation reference path");
  1251 #endif
  1256   // New alias types were created in split_AddP().
  1257   uint new_index_end = (uint) _compile->num_alias_types();
  1259   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
  1260   //            compute new values for Memory inputs  (the Memory inputs are not
  1261   //            actually updated until phase 4.)
  1262   if (memnode_worklist.length() == 0)
  1263     return;  // nothing to do
  1265   while (memnode_worklist.length() != 0) {
  1266     Node *n = memnode_worklist.pop();
  1267     if (visited.test_set(n->_idx))
  1268       continue;
  1269     if (n->is_Phi() || n->is_ClearArray()) {
  1270       // we don't need to do anything, but the users must be pushed
  1271     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
  1272       // we don't need to do anything, but the users must be pushed
  1273       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
  1274       if (n == NULL)
  1275         continue;
  1276     } else {
  1277       assert(n->is_Mem(), "memory node required.");
  1278       Node *addr = n->in(MemNode::Address);
  1279       const Type *addr_t = igvn->type(addr);
  1280       if (addr_t == Type::TOP)
  1281         continue;
  1282       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
  1283       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
  1284       assert ((uint)alias_idx < new_index_end, "wrong alias index");
  1285       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
  1286       if (_compile->failing()) {
  1287         return;
  1289       if (mem != n->in(MemNode::Memory)) {
  1290         // We delay the memory edge update since we need old one in
  1291         // MergeMem code below when instances memory slices are separated.
  1292         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
  1293         assert(pn == NULL || pn == n, "wrong node");
  1294         set_map(n->_idx, mem);
  1295         ptnode_adr(n->_idx)->_node = n;
  1297       if (n->is_Load()) {
  1298         continue;  // don't push users
  1299       } else if (n->is_LoadStore()) {
  1300         // get the memory projection
  1301         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1302           Node *use = n->fast_out(i);
  1303           if (use->Opcode() == Op_SCMemProj) {
  1304             n = use;
  1305             break;
  1308         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
  1311     // push user on appropriate worklist
  1312     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1313       Node *use = n->fast_out(i);
  1314       if (use->is_Phi() || use->is_ClearArray()) {
  1315         memnode_worklist.append_if_missing(use);
  1316       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
  1317         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
  1318           continue;
  1319         memnode_worklist.append_if_missing(use);
  1320       } else if (use->is_MemBar()) {
  1321         memnode_worklist.append_if_missing(use);
  1322 #ifdef ASSERT
  1323       } else if(use->is_Mem()) {
  1324         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
  1325       } else if (use->is_MergeMem()) {
  1326         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1327       } else {
  1328         uint op = use->Opcode();
  1329         if (!(op == Op_StoreCM ||
  1330               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
  1331                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
  1332               op == Op_AryEq || op == Op_StrComp ||
  1333               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1334           n->dump();
  1335           use->dump();
  1336           assert(false, "EA: missing memory path");
  1338 #endif
  1343   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
  1344   //            Walk each memory slice moving the first node encountered of each
  1345   //            instance type to the the input corresponding to its alias index.
  1346   uint length = _mergemem_worklist.length();
  1347   for( uint next = 0; next < length; ++next ) {
  1348     MergeMemNode* nmm = _mergemem_worklist.at(next);
  1349     assert(!visited.test_set(nmm->_idx), "should not be visited before");
  1350     // Note: we don't want to use MergeMemStream here because we only want to
  1351     // scan inputs which exist at the start, not ones we add during processing.
  1352     // Note 2: MergeMem may already contains instance memory slices added
  1353     // during find_inst_mem() call when memory nodes were processed above.
  1354     igvn->hash_delete(nmm);
  1355     uint nslices = nmm->req();
  1356     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
  1357       Node* mem = nmm->in(i);
  1358       Node* cur = NULL;
  1359       if (mem == NULL || mem->is_top())
  1360         continue;
  1361       // First, update mergemem by moving memory nodes to corresponding slices
  1362       // if their type became more precise since this mergemem was created.
  1363       while (mem->is_Mem()) {
  1364         const Type *at = igvn->type(mem->in(MemNode::Address));
  1365         if (at != Type::TOP) {
  1366           assert (at->isa_ptr() != NULL, "pointer type required.");
  1367           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
  1368           if (idx == i) {
  1369             if (cur == NULL)
  1370               cur = mem;
  1371           } else {
  1372             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
  1373               nmm->set_memory_at(idx, mem);
  1377         mem = mem->in(MemNode::Memory);
  1379       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
  1380       // Find any instance of the current type if we haven't encountered
  1381       // already a memory slice of the instance along the memory chain.
  1382       for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1383         if((uint)_compile->get_general_index(ni) == i) {
  1384           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
  1385           if (nmm->is_empty_memory(m)) {
  1386             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
  1387             if (_compile->failing()) {
  1388               return;
  1390             nmm->set_memory_at(ni, result);
  1395     // Find the rest of instances values
  1396     for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1397       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
  1398       Node* result = step_through_mergemem(nmm, ni, tinst);
  1399       if (result == nmm->base_memory()) {
  1400         // Didn't find instance memory, search through general slice recursively.
  1401         result = nmm->memory_at(_compile->get_general_index(ni));
  1402         result = find_inst_mem(result, ni, orig_phis, igvn);
  1403         if (_compile->failing()) {
  1404           return;
  1406         nmm->set_memory_at(ni, result);
  1409     igvn->hash_insert(nmm);
  1410     record_for_optimizer(nmm);
  1413   //  Phase 4:  Update the inputs of non-instance memory Phis and
  1414   //            the Memory input of memnodes
  1415   // First update the inputs of any non-instance Phi's from
  1416   // which we split out an instance Phi.  Note we don't have
  1417   // to recursively process Phi's encounted on the input memory
  1418   // chains as is done in split_memory_phi() since they  will
  1419   // also be processed here.
  1420   for (int j = 0; j < orig_phis.length(); j++) {
  1421     PhiNode *phi = orig_phis.at(j);
  1422     int alias_idx = _compile->get_alias_index(phi->adr_type());
  1423     igvn->hash_delete(phi);
  1424     for (uint i = 1; i < phi->req(); i++) {
  1425       Node *mem = phi->in(i);
  1426       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
  1427       if (_compile->failing()) {
  1428         return;
  1430       if (mem != new_mem) {
  1431         phi->set_req(i, new_mem);
  1434     igvn->hash_insert(phi);
  1435     record_for_optimizer(phi);
  1438   // Update the memory inputs of MemNodes with the value we computed
  1439   // in Phase 2 and move stores memory users to corresponding memory slices.
  1441   // Disable memory split verification code until the fix for 6984348.
  1442   // Currently it produces false negative results since it does not cover all cases.
  1443 #if 0 // ifdef ASSERT
  1444   visited.Reset();
  1445   Node_Stack old_mems(arena, _compile->unique() >> 2);
  1446 #endif
  1447   for (uint i = 0; i < nodes_size(); i++) {
  1448     Node *nmem = get_map(i);
  1449     if (nmem != NULL) {
  1450       Node *n = ptnode_adr(i)->_node;
  1451       assert(n != NULL, "sanity");
  1452       if (n->is_Mem()) {
  1453 #if 0 // ifdef ASSERT
  1454         Node* old_mem = n->in(MemNode::Memory);
  1455         if (!visited.test_set(old_mem->_idx)) {
  1456           old_mems.push(old_mem, old_mem->outcnt());
  1458 #endif
  1459         assert(n->in(MemNode::Memory) != nmem, "sanity");
  1460         if (!n->is_Load()) {
  1461           // Move memory users of a store first.
  1462           move_inst_mem(n, orig_phis, igvn);
  1464         // Now update memory input
  1465         igvn->hash_delete(n);
  1466         n->set_req(MemNode::Memory, nmem);
  1467         igvn->hash_insert(n);
  1468         record_for_optimizer(n);
  1469       } else {
  1470         assert(n->is_Allocate() || n->is_CheckCastPP() ||
  1471                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
  1475 #if 0 // ifdef ASSERT
  1476   // Verify that memory was split correctly
  1477   while (old_mems.is_nonempty()) {
  1478     Node* old_mem = old_mems.node();
  1479     uint  old_cnt = old_mems.index();
  1480     old_mems.pop();
  1481     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
  1483 #endif
  1486 bool ConnectionGraph::has_candidates(Compile *C) {
  1487   // EA brings benefits only when the code has allocations and/or locks which
  1488   // are represented by ideal Macro nodes.
  1489   int cnt = C->macro_count();
  1490   for( int i=0; i < cnt; i++ ) {
  1491     Node *n = C->macro_node(i);
  1492     if ( n->is_Allocate() )
  1493       return true;
  1494     if( n->is_Lock() ) {
  1495       Node* obj = n->as_Lock()->obj_node()->uncast();
  1496       if( !(obj->is_Parm() || obj->is_Con()) )
  1497         return true;
  1500   return false;
  1503 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  1504   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  1505   // to create space for them in ConnectionGraph::_nodes[].
  1506   Node* oop_null = igvn->zerocon(T_OBJECT);
  1507   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  1509   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  1510   // Perform escape analysis
  1511   if (congraph->compute_escape()) {
  1512     // There are non escaping objects.
  1513     C->set_congraph(congraph);
  1516   // Cleanup.
  1517   if (oop_null->outcnt() == 0)
  1518     igvn->hash_delete(oop_null);
  1519   if (noop_null->outcnt() == 0)
  1520     igvn->hash_delete(noop_null);
  1523 bool ConnectionGraph::compute_escape() {
  1524   Compile* C = _compile;
  1526   // 1. Populate Connection Graph (CG) with Ideal nodes.
  1528   Unique_Node_List worklist_init;
  1529   worklist_init.map(C->unique(), NULL);  // preallocate space
  1531   // Initialize worklist
  1532   if (C->root() != NULL) {
  1533     worklist_init.push(C->root());
  1536   GrowableArray<int> cg_worklist;
  1537   PhaseGVN* igvn = _igvn;
  1538   bool has_allocations = false;
  1540   // Push all useful nodes onto CG list and set their type.
  1541   for( uint next = 0; next < worklist_init.size(); ++next ) {
  1542     Node* n = worklist_init.at(next);
  1543     record_for_escape_analysis(n, igvn);
  1544     // Only allocations and java static calls results are checked
  1545     // for an escape status. See process_call_result() below.
  1546     if (n->is_Allocate() || n->is_CallStaticJava() &&
  1547         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
  1548       has_allocations = true;
  1550     if(n->is_AddP()) {
  1551       // Collect address nodes. Use them during stage 3 below
  1552       // to build initial connection graph field edges.
  1553       cg_worklist.append(n->_idx);
  1554     } else if (n->is_MergeMem()) {
  1555       // Collect all MergeMem nodes to add memory slices for
  1556       // scalar replaceable objects in split_unique_types().
  1557       _mergemem_worklist.append(n->as_MergeMem());
  1559     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1560       Node* m = n->fast_out(i);   // Get user
  1561       worklist_init.push(m);
  1565   if (!has_allocations) {
  1566     _collecting = false;
  1567     return false; // Nothing to do.
  1570   // 2. First pass to create simple CG edges (doesn't require to walk CG).
  1571   uint delayed_size = _delayed_worklist.size();
  1572   for( uint next = 0; next < delayed_size; ++next ) {
  1573     Node* n = _delayed_worklist.at(next);
  1574     build_connection_graph(n, igvn);
  1577   // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
  1578   //    to reduce number of iterations during stage 4 below.
  1579   uint cg_length = cg_worklist.length();
  1580   for( uint next = 0; next < cg_length; ++next ) {
  1581     int ni = cg_worklist.at(next);
  1582     Node* n = ptnode_adr(ni)->_node;
  1583     Node* base = get_addp_base(n);
  1584     if (base->is_Proj())
  1585       base = base->in(0);
  1586     PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
  1587     if (nt == PointsToNode::JavaObject) {
  1588       build_connection_graph(n, igvn);
  1592   cg_worklist.clear();
  1593   cg_worklist.append(_phantom_object);
  1594   GrowableArray<uint>  worklist;
  1596   // 4. Build Connection Graph which need
  1597   //    to walk the connection graph.
  1598   _progress = false;
  1599   for (uint ni = 0; ni < nodes_size(); ni++) {
  1600     PointsToNode* ptn = ptnode_adr(ni);
  1601     Node *n = ptn->_node;
  1602     if (n != NULL) { // Call, AddP, LoadP, StoreP
  1603       build_connection_graph(n, igvn);
  1604       if (ptn->node_type() != PointsToNode::UnknownType)
  1605         cg_worklist.append(n->_idx); // Collect CG nodes
  1606       if (!_processed.test(n->_idx))
  1607         worklist.append(n->_idx); // Collect C/A/L/S nodes
  1611   // After IGVN user nodes may have smaller _idx than
  1612   // their inputs so they will be processed first in
  1613   // previous loop. Because of that not all Graph
  1614   // edges will be created. Walk over interesting
  1615   // nodes again until no new edges are created.
  1616   //
  1617   // Normally only 1-3 passes needed to build
  1618   // Connection Graph depending on graph complexity.
  1619   // Observed 8 passes in jvm2008 compiler.compiler.
  1620   // Set limit to 20 to catch situation when something
  1621   // did go wrong and recompile the method without EA.
  1623 #define CG_BUILD_ITER_LIMIT 20
  1625   uint length = worklist.length();
  1626   int iterations = 0;
  1627   while(_progress && (iterations++ < CG_BUILD_ITER_LIMIT)) {
  1628     _progress = false;
  1629     for( uint next = 0; next < length; ++next ) {
  1630       int ni = worklist.at(next);
  1631       PointsToNode* ptn = ptnode_adr(ni);
  1632       Node* n = ptn->_node;
  1633       assert(n != NULL, "should be known node");
  1634       build_connection_graph(n, igvn);
  1637   if (iterations >= CG_BUILD_ITER_LIMIT) {
  1638     assert(iterations < CG_BUILD_ITER_LIMIT,
  1639            err_msg("infinite EA connection graph build with %d nodes and worklist size %d",
  1640            nodes_size(), length));
  1641     // Possible infinite build_connection_graph loop,
  1642     // retry compilation without escape analysis.
  1643     C->record_failure(C2Compiler::retry_no_escape_analysis());
  1644     _collecting = false;
  1645     return false;
  1647 #undef CG_BUILD_ITER_LIMIT
  1649   Arena* arena = Thread::current()->resource_area();
  1650   VectorSet visited(arena);
  1651   worklist.clear();
  1653   // 5. Remove deferred edges from the graph and adjust
  1654   //    escape state of nonescaping objects.
  1655   cg_length = cg_worklist.length();
  1656   for( uint next = 0; next < cg_length; ++next ) {
  1657     int ni = cg_worklist.at(next);
  1658     PointsToNode* ptn = ptnode_adr(ni);
  1659     PointsToNode::NodeType nt = ptn->node_type();
  1660     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
  1661       remove_deferred(ni, &worklist, &visited);
  1662       Node *n = ptn->_node;
  1663       if (n->is_AddP()) {
  1664         // Search for objects which are not scalar replaceable
  1665         // and adjust their escape state.
  1666         adjust_escape_state(ni, igvn);
  1671   // 6. Propagate escape states.
  1672   worklist.clear();
  1673   bool has_non_escaping_obj = false;
  1675   // push all GlobalEscape nodes on the worklist
  1676   for( uint next = 0; next < cg_length; ++next ) {
  1677     int nk = cg_worklist.at(next);
  1678     if (ptnode_adr(nk)->escape_state() == PointsToNode::GlobalEscape)
  1679       worklist.push(nk);
  1681   // mark all nodes reachable from GlobalEscape nodes
  1682   while(worklist.length() > 0) {
  1683     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1684     uint e_cnt = ptn->edge_count();
  1685     for (uint ei = 0; ei < e_cnt; ei++) {
  1686       uint npi = ptn->edge_target(ei);
  1687       PointsToNode *np = ptnode_adr(npi);
  1688       if (np->escape_state() < PointsToNode::GlobalEscape) {
  1689         np->set_escape_state(PointsToNode::GlobalEscape);
  1690         worklist.push(npi);
  1695   // push all ArgEscape nodes on the worklist
  1696   for( uint next = 0; next < cg_length; ++next ) {
  1697     int nk = cg_worklist.at(next);
  1698     if (ptnode_adr(nk)->escape_state() == PointsToNode::ArgEscape)
  1699       worklist.push(nk);
  1701   // mark all nodes reachable from ArgEscape nodes
  1702   while(worklist.length() > 0) {
  1703     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1704     if (ptn->node_type() == PointsToNode::JavaObject)
  1705       has_non_escaping_obj = true; // Non GlobalEscape
  1706     uint e_cnt = ptn->edge_count();
  1707     for (uint ei = 0; ei < e_cnt; ei++) {
  1708       uint npi = ptn->edge_target(ei);
  1709       PointsToNode *np = ptnode_adr(npi);
  1710       if (np->escape_state() < PointsToNode::ArgEscape) {
  1711         np->set_escape_state(PointsToNode::ArgEscape);
  1712         worklist.push(npi);
  1717   GrowableArray<Node*> alloc_worklist;
  1719   // push all NoEscape nodes on the worklist
  1720   for( uint next = 0; next < cg_length; ++next ) {
  1721     int nk = cg_worklist.at(next);
  1722     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
  1723       worklist.push(nk);
  1725   // mark all nodes reachable from NoEscape nodes
  1726   while(worklist.length() > 0) {
  1727     PointsToNode* ptn = ptnode_adr(worklist.pop());
  1728     if (ptn->node_type() == PointsToNode::JavaObject)
  1729       has_non_escaping_obj = true; // Non GlobalEscape
  1730     Node* n = ptn->_node;
  1731     if (n->is_Allocate() && ptn->_scalar_replaceable ) {
  1732       // Push scalar replaceable allocations on alloc_worklist
  1733       // for processing in split_unique_types().
  1734       alloc_worklist.append(n);
  1736     uint e_cnt = ptn->edge_count();
  1737     for (uint ei = 0; ei < e_cnt; ei++) {
  1738       uint npi = ptn->edge_target(ei);
  1739       PointsToNode *np = ptnode_adr(npi);
  1740       if (np->escape_state() < PointsToNode::NoEscape) {
  1741         np->set_escape_state(PointsToNode::NoEscape);
  1742         worklist.push(npi);
  1747   _collecting = false;
  1748   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
  1750 #ifndef PRODUCT
  1751   if (PrintEscapeAnalysis) {
  1752     dump(); // Dump ConnectionGraph
  1754 #endif
  1756   bool has_scalar_replaceable_candidates = alloc_worklist.length() > 0;
  1757   if ( has_scalar_replaceable_candidates &&
  1758        C->AliasLevel() >= 3 && EliminateAllocations ) {
  1760     // Now use the escape information to create unique types for
  1761     // scalar replaceable objects.
  1762     split_unique_types(alloc_worklist);
  1764     if (C->failing())  return false;
  1766     C->print_method("After Escape Analysis", 2);
  1768 #ifdef ASSERT
  1769   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
  1770     tty->print("=== No allocations eliminated for ");
  1771     C->method()->print_short_name();
  1772     if(!EliminateAllocations) {
  1773       tty->print(" since EliminateAllocations is off ===");
  1774     } else if(!has_scalar_replaceable_candidates) {
  1775       tty->print(" since there are no scalar replaceable candidates ===");
  1776     } else if(C->AliasLevel() < 3) {
  1777       tty->print(" since AliasLevel < 3 ===");
  1779     tty->cr();
  1780 #endif
  1782   return has_non_escaping_obj;
  1785 // Adjust escape state after Connection Graph is built.
  1786 void ConnectionGraph::adjust_escape_state(int nidx, PhaseTransform* phase) {
  1787   PointsToNode* ptn = ptnode_adr(nidx);
  1788   Node* n = ptn->_node;
  1789   assert(n->is_AddP(), "Should be called for AddP nodes only");
  1790   // Search for objects which are not scalar replaceable.
  1791   // Mark their escape state as ArgEscape to propagate the state
  1792   // to referenced objects.
  1793   // Note: currently there are no difference in compiler optimizations
  1794   // for ArgEscape objects and NoEscape objects which are not
  1795   // scalar replaceable.
  1797   Compile* C = _compile;
  1799   int offset = ptn->offset();
  1800   Node* base = get_addp_base(n);
  1801   VectorSet* ptset = PointsTo(base);
  1802   int ptset_size = ptset->Size();
  1804   // Check if a oop field's initializing value is recorded and add
  1805   // a corresponding NULL field's value if it is not recorded.
  1806   // Connection Graph does not record a default initialization by NULL
  1807   // captured by Initialize node.
  1808   //
  1809   // Note: it will disable scalar replacement in some cases:
  1810   //
  1811   //    Point p[] = new Point[1];
  1812   //    p[0] = new Point(); // Will be not scalar replaced
  1813   //
  1814   // but it will save us from incorrect optimizations in next cases:
  1815   //
  1816   //    Point p[] = new Point[1];
  1817   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
  1818   //
  1819   // Do a simple control flow analysis to distinguish above cases.
  1820   //
  1821   if (offset != Type::OffsetBot && ptset_size == 1) {
  1822     uint elem = ptset->getelem(); // Allocation node's index
  1823     // It does not matter if it is not Allocation node since
  1824     // only non-escaping allocations are scalar replaced.
  1825     if (ptnode_adr(elem)->_node->is_Allocate() &&
  1826         ptnode_adr(elem)->escape_state() == PointsToNode::NoEscape) {
  1827       AllocateNode* alloc = ptnode_adr(elem)->_node->as_Allocate();
  1828       InitializeNode* ini = alloc->initialization();
  1830       // Check only oop fields.
  1831       const Type* adr_type = n->as_AddP()->bottom_type();
  1832       BasicType basic_field_type = T_INT;
  1833       if (adr_type->isa_instptr()) {
  1834         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
  1835         if (field != NULL) {
  1836           basic_field_type = field->layout_type();
  1837         } else {
  1838           // Ignore non field load (for example, klass load)
  1840       } else if (adr_type->isa_aryptr()) {
  1841         const Type* elemtype = adr_type->isa_aryptr()->elem();
  1842         basic_field_type = elemtype->array_element_basic_type();
  1843       } else {
  1844         // Raw pointers are used for initializing stores so skip it.
  1845         assert(adr_type->isa_rawptr() && base->is_Proj() &&
  1846                (base->in(0) == alloc),"unexpected pointer type");
  1848       if (basic_field_type == T_OBJECT ||
  1849           basic_field_type == T_NARROWOOP ||
  1850           basic_field_type == T_ARRAY) {
  1851         Node* value = NULL;
  1852         if (ini != NULL) {
  1853           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
  1854           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
  1855           if (store != NULL && store->is_Store()) {
  1856             value = store->in(MemNode::ValueIn);
  1857           } else if (ptn->edge_count() > 0) { // Are there oop stores?
  1858             // Check for a store which follows allocation without branches.
  1859             // For example, a volatile field store is not collected
  1860             // by Initialize node. TODO: it would be nice to use idom() here.
  1861             for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1862               store = n->fast_out(i);
  1863               if (store->is_Store() && store->in(0) != NULL) {
  1864                 Node* ctrl = store->in(0);
  1865                 while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
  1866                         ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
  1867                         ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
  1868                    ctrl = ctrl->in(0);
  1870                 if (ctrl == ini || ctrl == alloc) {
  1871                   value = store->in(MemNode::ValueIn);
  1872                   break;
  1878         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
  1879           // A field's initializing value was not recorded. Add NULL.
  1880           uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
  1881           add_pointsto_edge(nidx, null_idx);
  1887   // An object is not scalar replaceable if the field which may point
  1888   // to it has unknown offset (unknown element of an array of objects).
  1889   //
  1890   if (offset == Type::OffsetBot) {
  1891     uint e_cnt = ptn->edge_count();
  1892     for (uint ei = 0; ei < e_cnt; ei++) {
  1893       uint npi = ptn->edge_target(ei);
  1894       set_escape_state(npi, PointsToNode::ArgEscape);
  1895       ptnode_adr(npi)->_scalar_replaceable = false;
  1899   // Currently an object is not scalar replaceable if a LoadStore node
  1900   // access its field since the field value is unknown after it.
  1901   //
  1902   bool has_LoadStore = false;
  1903   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1904     Node *use = n->fast_out(i);
  1905     if (use->is_LoadStore()) {
  1906       has_LoadStore = true;
  1907       break;
  1910   // An object is not scalar replaceable if the address points
  1911   // to unknown field (unknown element for arrays, offset is OffsetBot).
  1912   //
  1913   // Or the address may point to more then one object. This may produce
  1914   // the false positive result (set scalar_replaceable to false)
  1915   // since the flow-insensitive escape analysis can't separate
  1916   // the case when stores overwrite the field's value from the case
  1917   // when stores happened on different control branches.
  1918   //
  1919   if (ptset_size > 1 || ptset_size != 0 &&
  1920       (has_LoadStore || offset == Type::OffsetBot)) {
  1921     for( VectorSetI j(ptset); j.test(); ++j ) {
  1922       set_escape_state(j.elem, PointsToNode::ArgEscape);
  1923       ptnode_adr(j.elem)->_scalar_replaceable = false;
  1928 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
  1930     switch (call->Opcode()) {
  1931 #ifdef ASSERT
  1932     case Op_Allocate:
  1933     case Op_AllocateArray:
  1934     case Op_Lock:
  1935     case Op_Unlock:
  1936       assert(false, "should be done already");
  1937       break;
  1938 #endif
  1939     case Op_CallLeaf:
  1940     case Op_CallLeafNoFP:
  1942       // Stub calls, objects do not escape but they are not scale replaceable.
  1943       // Adjust escape state for outgoing arguments.
  1944       const TypeTuple * d = call->tf()->domain();
  1945       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1946         const Type* at = d->field_at(i);
  1947         Node *arg = call->in(i)->uncast();
  1948         const Type *aat = phase->type(arg);
  1949         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
  1950             ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
  1952           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
  1953                  aat->isa_ptr() != NULL, "expecting an Ptr");
  1954 #ifdef ASSERT
  1955           if (!(call->Opcode() == Op_CallLeafNoFP &&
  1956                 call->as_CallLeaf()->_name != NULL &&
  1957                 (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
  1958                 call->as_CallLeaf()->_name != NULL &&
  1959                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
  1960                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
  1961           ) {
  1962             call->dump();
  1963             assert(false, "EA: unexpected CallLeaf");
  1965 #endif
  1966           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  1967           if (arg->is_AddP()) {
  1968             //
  1969             // The inline_native_clone() case when the arraycopy stub is called
  1970             // after the allocation before Initialize and CheckCastPP nodes.
  1971             //
  1972             // Set AddP's base (Allocate) as not scalar replaceable since
  1973             // pointer to the base (with offset) is passed as argument.
  1974             //
  1975             arg = get_addp_base(arg);
  1977           for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  1978             uint pt = j.elem;
  1979             set_escape_state(pt, PointsToNode::ArgEscape);
  1983       break;
  1986     case Op_CallStaticJava:
  1987     // For a static call, we know exactly what method is being called.
  1988     // Use bytecode estimator to record the call's escape affects
  1990       ciMethod *meth = call->as_CallJava()->method();
  1991       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
  1992       // fall-through if not a Java method or no analyzer information
  1993       if (call_analyzer != NULL) {
  1994         const TypeTuple * d = call->tf()->domain();
  1995         bool copy_dependencies = false;
  1996         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  1997           const Type* at = d->field_at(i);
  1998           int k = i - TypeFunc::Parms;
  1999           Node *arg = call->in(i)->uncast();
  2001           if (at->isa_oopptr() != NULL &&
  2002               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
  2004             bool global_escapes = false;
  2005             bool fields_escapes = false;
  2006             if (!call_analyzer->is_arg_stack(k)) {
  2007               // The argument global escapes, mark everything it could point to
  2008               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2009               global_escapes = true;
  2010             } else {
  2011               if (!call_analyzer->is_arg_local(k)) {
  2012                 // The argument itself doesn't escape, but any fields might
  2013                 fields_escapes = true;
  2015               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  2016               copy_dependencies = true;
  2019             for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2020               uint pt = j.elem;
  2021               if (global_escapes) {
  2022                 //The argument global escapes, mark everything it could point to
  2023                 set_escape_state(pt, PointsToNode::GlobalEscape);
  2024               } else {
  2025                 if (fields_escapes) {
  2026                   // The argument itself doesn't escape, but any fields might
  2027                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  2029                 set_escape_state(pt, PointsToNode::ArgEscape);
  2034         if (copy_dependencies)
  2035           call_analyzer->copy_dependencies(_compile->dependencies());
  2036         break;
  2040     default:
  2041     // Fall-through here if not a Java method or no analyzer information
  2042     // or some other type of call, assume the worst case: all arguments
  2043     // globally escape.
  2045       // adjust escape state for  outgoing arguments
  2046       const TypeTuple * d = call->tf()->domain();
  2047       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2048         const Type* at = d->field_at(i);
  2049         if (at->isa_oopptr() != NULL) {
  2050           Node *arg = call->in(i)->uncast();
  2051           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2052           for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2053             uint pt = j.elem;
  2054             set_escape_state(pt, PointsToNode::GlobalEscape);
  2061 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
  2062   CallNode   *call = resproj->in(0)->as_Call();
  2063   uint    call_idx = call->_idx;
  2064   uint resproj_idx = resproj->_idx;
  2066   switch (call->Opcode()) {
  2067     case Op_Allocate:
  2069       Node *k = call->in(AllocateNode::KlassNode);
  2070       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2071       assert(kt != NULL, "TypeKlassPtr  required.");
  2072       ciKlass* cik = kt->klass();
  2074       PointsToNode::EscapeState es;
  2075       uint edge_to;
  2076       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
  2077          !cik->is_instance_klass() || // StressReflectiveCode
  2078           cik->as_instance_klass()->has_finalizer()) {
  2079         es = PointsToNode::GlobalEscape;
  2080         edge_to = _phantom_object; // Could not be worse
  2081       } else {
  2082         es = PointsToNode::NoEscape;
  2083         edge_to = call_idx;
  2085       set_escape_state(call_idx, es);
  2086       add_pointsto_edge(resproj_idx, edge_to);
  2087       _processed.set(resproj_idx);
  2088       break;
  2091     case Op_AllocateArray:
  2094       Node *k = call->in(AllocateNode::KlassNode);
  2095       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2096       assert(kt != NULL, "TypeKlassPtr  required.");
  2097       ciKlass* cik = kt->klass();
  2099       PointsToNode::EscapeState es;
  2100       uint edge_to;
  2101       if (!cik->is_array_klass()) { // StressReflectiveCode
  2102         es = PointsToNode::GlobalEscape;
  2103         edge_to = _phantom_object;
  2104       } else {
  2105         es = PointsToNode::NoEscape;
  2106         edge_to = call_idx;
  2107         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
  2108         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
  2109           // Not scalar replaceable if the length is not constant or too big.
  2110           ptnode_adr(call_idx)->_scalar_replaceable = false;
  2113       set_escape_state(call_idx, es);
  2114       add_pointsto_edge(resproj_idx, edge_to);
  2115       _processed.set(resproj_idx);
  2116       break;
  2119     case Op_CallStaticJava:
  2120     // For a static call, we know exactly what method is being called.
  2121     // Use bytecode estimator to record whether the call's return value escapes
  2123       bool done = true;
  2124       const TypeTuple *r = call->tf()->range();
  2125       const Type* ret_type = NULL;
  2127       if (r->cnt() > TypeFunc::Parms)
  2128         ret_type = r->field_at(TypeFunc::Parms);
  2130       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2131       //        _multianewarray functions return a TypeRawPtr.
  2132       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
  2133         _processed.set(resproj_idx);
  2134         break;  // doesn't return a pointer type
  2136       ciMethod *meth = call->as_CallJava()->method();
  2137       const TypeTuple * d = call->tf()->domain();
  2138       if (meth == NULL) {
  2139         // not a Java method, assume global escape
  2140         set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2141         add_pointsto_edge(resproj_idx, _phantom_object);
  2142       } else {
  2143         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
  2144         bool copy_dependencies = false;
  2146         if (call_analyzer->is_return_allocated()) {
  2147           // Returns a newly allocated unescaped object, simply
  2148           // update dependency information.
  2149           // Mark it as NoEscape so that objects referenced by
  2150           // it's fields will be marked as NoEscape at least.
  2151           set_escape_state(call_idx, PointsToNode::NoEscape);
  2152           add_pointsto_edge(resproj_idx, call_idx);
  2153           copy_dependencies = true;
  2154         } else if (call_analyzer->is_return_local()) {
  2155           // determine whether any arguments are returned
  2156           set_escape_state(call_idx, PointsToNode::NoEscape);
  2157           bool ret_arg = false;
  2158           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2159             const Type* at = d->field_at(i);
  2161             if (at->isa_oopptr() != NULL) {
  2162               Node *arg = call->in(i)->uncast();
  2164               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
  2165                 ret_arg = true;
  2166                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2167                 if (arg_esp->node_type() == PointsToNode::UnknownType)
  2168                   done = false;
  2169                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
  2170                   add_pointsto_edge(resproj_idx, arg->_idx);
  2171                 else
  2172                   add_deferred_edge(resproj_idx, arg->_idx);
  2173                 arg_esp->_hidden_alias = true;
  2177           if (done && !ret_arg) {
  2178             // Returns unknown object.
  2179             set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2180             add_pointsto_edge(resproj_idx, _phantom_object);
  2182           copy_dependencies = true;
  2183         } else {
  2184           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2185           add_pointsto_edge(resproj_idx, _phantom_object);
  2186           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2187             const Type* at = d->field_at(i);
  2188             if (at->isa_oopptr() != NULL) {
  2189               Node *arg = call->in(i)->uncast();
  2190               PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2191               arg_esp->_hidden_alias = true;
  2195         if (copy_dependencies)
  2196           call_analyzer->copy_dependencies(_compile->dependencies());
  2198       if (done)
  2199         _processed.set(resproj_idx);
  2200       break;
  2203     default:
  2204     // Some other type of call, assume the worst case that the
  2205     // returned value, if any, globally escapes.
  2207       const TypeTuple *r = call->tf()->range();
  2208       if (r->cnt() > TypeFunc::Parms) {
  2209         const Type* ret_type = r->field_at(TypeFunc::Parms);
  2211         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2212         //        _multianewarray functions return a TypeRawPtr.
  2213         if (ret_type->isa_ptr() != NULL) {
  2214           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2215           add_pointsto_edge(resproj_idx, _phantom_object);
  2218       _processed.set(resproj_idx);
  2223 // Populate Connection Graph with Ideal nodes and create simple
  2224 // connection graph edges (do not need to check the node_type of inputs
  2225 // or to call PointsTo() to walk the connection graph).
  2226 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
  2227   if (_processed.test(n->_idx))
  2228     return; // No need to redefine node's state.
  2230   if (n->is_Call()) {
  2231     // Arguments to allocation and locking don't escape.
  2232     if (n->is_Allocate()) {
  2233       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
  2234       record_for_optimizer(n);
  2235     } else if (n->is_Lock() || n->is_Unlock()) {
  2236       // Put Lock and Unlock nodes on IGVN worklist to process them during
  2237       // the first IGVN optimization when escape information is still available.
  2238       record_for_optimizer(n);
  2239       _processed.set(n->_idx);
  2240     } else {
  2241       // Don't mark as processed since call's arguments have to be processed.
  2242       PointsToNode::NodeType nt = PointsToNode::UnknownType;
  2243       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
  2245       // Check if a call returns an object.
  2246       const TypeTuple *r = n->as_Call()->tf()->range();
  2247       if (r->cnt() > TypeFunc::Parms &&
  2248           r->field_at(TypeFunc::Parms)->isa_ptr() &&
  2249           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
  2250         nt = PointsToNode::JavaObject;
  2251         if (!n->is_CallStaticJava()) {
  2252           // Since the called mathod is statically unknown assume
  2253           // the worst case that the returned value globally escapes.
  2254           es = PointsToNode::GlobalEscape;
  2257       add_node(n, nt, es, false);
  2259     return;
  2262   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
  2263   // ThreadLocal has RawPrt type.
  2264   switch (n->Opcode()) {
  2265     case Op_AddP:
  2267       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
  2268       break;
  2270     case Op_CastX2P:
  2271     { // "Unsafe" memory access.
  2272       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2273       break;
  2275     case Op_CastPP:
  2276     case Op_CheckCastPP:
  2277     case Op_EncodeP:
  2278     case Op_DecodeN:
  2280       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2281       int ti = n->in(1)->_idx;
  2282       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2283       if (nt == PointsToNode::UnknownType) {
  2284         _delayed_worklist.push(n); // Process it later.
  2285         break;
  2286       } else if (nt == PointsToNode::JavaObject) {
  2287         add_pointsto_edge(n->_idx, ti);
  2288       } else {
  2289         add_deferred_edge(n->_idx, ti);
  2291       _processed.set(n->_idx);
  2292       break;
  2294     case Op_ConP:
  2296       // assume all pointer constants globally escape except for null
  2297       PointsToNode::EscapeState es;
  2298       if (phase->type(n) == TypePtr::NULL_PTR)
  2299         es = PointsToNode::NoEscape;
  2300       else
  2301         es = PointsToNode::GlobalEscape;
  2303       add_node(n, PointsToNode::JavaObject, es, true);
  2304       break;
  2306     case Op_ConN:
  2308       // assume all narrow oop constants globally escape except for null
  2309       PointsToNode::EscapeState es;
  2310       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
  2311         es = PointsToNode::NoEscape;
  2312       else
  2313         es = PointsToNode::GlobalEscape;
  2315       add_node(n, PointsToNode::JavaObject, es, true);
  2316       break;
  2318     case Op_CreateEx:
  2320       // assume that all exception objects globally escape
  2321       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2322       break;
  2324     case Op_LoadKlass:
  2325     case Op_LoadNKlass:
  2327       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2328       break;
  2330     case Op_LoadP:
  2331     case Op_LoadN:
  2333       const Type *t = phase->type(n);
  2334       if (t->make_ptr() == NULL) {
  2335         _processed.set(n->_idx);
  2336         return;
  2338       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2339       break;
  2341     case Op_Parm:
  2343       _processed.set(n->_idx); // No need to redefine it state.
  2344       uint con = n->as_Proj()->_con;
  2345       if (con < TypeFunc::Parms)
  2346         return;
  2347       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
  2348       if (t->isa_ptr() == NULL)
  2349         return;
  2350       // We have to assume all input parameters globally escape
  2351       // (Note: passing 'false' since _processed is already set).
  2352       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
  2353       break;
  2355     case Op_Phi:
  2357       const Type *t = n->as_Phi()->type();
  2358       if (t->make_ptr() == NULL) {
  2359         // nothing to do if not an oop or narrow oop
  2360         _processed.set(n->_idx);
  2361         return;
  2363       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2364       uint i;
  2365       for (i = 1; i < n->req() ; i++) {
  2366         Node* in = n->in(i);
  2367         if (in == NULL)
  2368           continue;  // ignore NULL
  2369         in = in->uncast();
  2370         if (in->is_top() || in == n)
  2371           continue;  // ignore top or inputs which go back this node
  2372         int ti = in->_idx;
  2373         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2374         if (nt == PointsToNode::UnknownType) {
  2375           break;
  2376         } else if (nt == PointsToNode::JavaObject) {
  2377           add_pointsto_edge(n->_idx, ti);
  2378         } else {
  2379           add_deferred_edge(n->_idx, ti);
  2382       if (i >= n->req())
  2383         _processed.set(n->_idx);
  2384       else
  2385         _delayed_worklist.push(n);
  2386       break;
  2388     case Op_Proj:
  2390       // we are only interested in the oop result projection from a call
  2391       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2392         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2393         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2394         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2395           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2396           int ti = n->in(0)->_idx;
  2397           // The call may not be registered yet (since not all its inputs are registered)
  2398           // if this is the projection from backbranch edge of Phi.
  2399           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
  2400             process_call_result(n->as_Proj(), phase);
  2402           if (!_processed.test(n->_idx)) {
  2403             // The call's result may need to be processed later if the call
  2404             // returns it's argument and the argument is not processed yet.
  2405             _delayed_worklist.push(n);
  2407           break;
  2410       _processed.set(n->_idx);
  2411       break;
  2413     case Op_Return:
  2415       if( n->req() > TypeFunc::Parms &&
  2416           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2417         // Treat Return value as LocalVar with GlobalEscape escape state.
  2418         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
  2419         int ti = n->in(TypeFunc::Parms)->_idx;
  2420         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2421         if (nt == PointsToNode::UnknownType) {
  2422           _delayed_worklist.push(n); // Process it later.
  2423           break;
  2424         } else if (nt == PointsToNode::JavaObject) {
  2425           add_pointsto_edge(n->_idx, ti);
  2426         } else {
  2427           add_deferred_edge(n->_idx, ti);
  2430       _processed.set(n->_idx);
  2431       break;
  2433     case Op_StoreP:
  2434     case Op_StoreN:
  2436       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2437       adr_type = adr_type->make_ptr();
  2438       if (adr_type->isa_oopptr()) {
  2439         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2440       } else {
  2441         Node* adr = n->in(MemNode::Address);
  2442         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
  2443             adr->in(AddPNode::Address)->is_Proj() &&
  2444             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
  2445           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2446           // We are computing a raw address for a store captured
  2447           // by an Initialize compute an appropriate address type.
  2448           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
  2449           assert(offs != Type::OffsetBot, "offset must be a constant");
  2450         } else {
  2451           _processed.set(n->_idx);
  2452           return;
  2455       break;
  2457     case Op_StorePConditional:
  2458     case Op_CompareAndSwapP:
  2459     case Op_CompareAndSwapN:
  2461       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2462       adr_type = adr_type->make_ptr();
  2463       if (adr_type->isa_oopptr()) {
  2464         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2465       } else {
  2466         _processed.set(n->_idx);
  2467         return;
  2469       break;
  2471     case Op_AryEq:
  2472     case Op_StrComp:
  2473     case Op_StrEquals:
  2474     case Op_StrIndexOf:
  2476       // char[] arrays passed to string intrinsics are not scalar replaceable.
  2477       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2478       break;
  2480     case Op_ThreadLocal:
  2482       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
  2483       break;
  2485     default:
  2487       // nothing to do
  2489   return;
  2492 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
  2493   uint n_idx = n->_idx;
  2494   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
  2496   // Don't set processed bit for AddP, LoadP, StoreP since
  2497   // they may need more then one pass to process.
  2498   // Also don't mark as processed Call nodes since their
  2499   // arguments may need more then one pass to process.
  2500   if (_processed.test(n_idx))
  2501     return; // No need to redefine node's state.
  2503   if (n->is_Call()) {
  2504     CallNode *call = n->as_Call();
  2505     process_call_arguments(call, phase);
  2506     return;
  2509   switch (n->Opcode()) {
  2510     case Op_AddP:
  2512       Node *base = get_addp_base(n);
  2513       // Create a field edge to this node from everything base could point to.
  2514       for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
  2515         uint pt = i.elem;
  2516         add_field_edge(pt, n_idx, address_offset(n, phase));
  2518       break;
  2520     case Op_CastX2P:
  2522       assert(false, "Op_CastX2P");
  2523       break;
  2525     case Op_CastPP:
  2526     case Op_CheckCastPP:
  2527     case Op_EncodeP:
  2528     case Op_DecodeN:
  2530       int ti = n->in(1)->_idx;
  2531       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
  2532       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2533         add_pointsto_edge(n_idx, ti);
  2534       } else {
  2535         add_deferred_edge(n_idx, ti);
  2537       _processed.set(n_idx);
  2538       break;
  2540     case Op_ConP:
  2542       assert(false, "Op_ConP");
  2543       break;
  2545     case Op_ConN:
  2547       assert(false, "Op_ConN");
  2548       break;
  2550     case Op_CreateEx:
  2552       assert(false, "Op_CreateEx");
  2553       break;
  2555     case Op_LoadKlass:
  2556     case Op_LoadNKlass:
  2558       assert(false, "Op_LoadKlass");
  2559       break;
  2561     case Op_LoadP:
  2562     case Op_LoadN:
  2564       const Type *t = phase->type(n);
  2565 #ifdef ASSERT
  2566       if (t->make_ptr() == NULL)
  2567         assert(false, "Op_LoadP");
  2568 #endif
  2570       Node* adr = n->in(MemNode::Address)->uncast();
  2571       Node* adr_base;
  2572       if (adr->is_AddP()) {
  2573         adr_base = get_addp_base(adr);
  2574       } else {
  2575         adr_base = adr;
  2578       // For everything "adr_base" could point to, create a deferred edge from
  2579       // this node to each field with the same offset.
  2580       int offset = address_offset(adr, phase);
  2581       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
  2582         uint pt = i.elem;
  2583         add_deferred_edge_to_fields(n_idx, pt, offset);
  2585       break;
  2587     case Op_Parm:
  2589       assert(false, "Op_Parm");
  2590       break;
  2592     case Op_Phi:
  2594 #ifdef ASSERT
  2595       const Type *t = n->as_Phi()->type();
  2596       if (t->make_ptr() == NULL)
  2597         assert(false, "Op_Phi");
  2598 #endif
  2599       for (uint i = 1; i < n->req() ; i++) {
  2600         Node* in = n->in(i);
  2601         if (in == NULL)
  2602           continue;  // ignore NULL
  2603         in = in->uncast();
  2604         if (in->is_top() || in == n)
  2605           continue;  // ignore top or inputs which go back this node
  2606         int ti = in->_idx;
  2607         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2608         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
  2609         if (nt == PointsToNode::JavaObject) {
  2610           add_pointsto_edge(n_idx, ti);
  2611         } else {
  2612           add_deferred_edge(n_idx, ti);
  2615       _processed.set(n_idx);
  2616       break;
  2618     case Op_Proj:
  2620       // we are only interested in the oop result projection from a call
  2621       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2622         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
  2623                "all nodes should be registered");
  2624         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2625         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2626         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2627           process_call_result(n->as_Proj(), phase);
  2628           assert(_processed.test(n_idx), "all call results should be processed");
  2629           break;
  2632       assert(false, "Op_Proj");
  2633       break;
  2635     case Op_Return:
  2637 #ifdef ASSERT
  2638       if( n->req() <= TypeFunc::Parms ||
  2639           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2640         assert(false, "Op_Return");
  2642 #endif
  2643       int ti = n->in(TypeFunc::Parms)->_idx;
  2644       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
  2645       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2646         add_pointsto_edge(n_idx, ti);
  2647       } else {
  2648         add_deferred_edge(n_idx, ti);
  2650       _processed.set(n_idx);
  2651       break;
  2653     case Op_StoreP:
  2654     case Op_StoreN:
  2655     case Op_StorePConditional:
  2656     case Op_CompareAndSwapP:
  2657     case Op_CompareAndSwapN:
  2659       Node *adr = n->in(MemNode::Address);
  2660       const Type *adr_type = phase->type(adr)->make_ptr();
  2661 #ifdef ASSERT
  2662       if (!adr_type->isa_oopptr())
  2663         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
  2664 #endif
  2666       assert(adr->is_AddP(), "expecting an AddP");
  2667       Node *adr_base = get_addp_base(adr);
  2668       Node *val = n->in(MemNode::ValueIn)->uncast();
  2669       // For everything "adr_base" could point to, create a deferred edge
  2670       // to "val" from each field with the same offset.
  2671       for( VectorSetI i(PointsTo(adr_base)); 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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