src/share/vm/opto/escape.cpp

Mon, 07 Nov 2011 14:33:57 -0800

author
kvn
date
Mon, 07 Nov 2011 14:33:57 -0800
changeset 3254
59e515ee9354
parent 3242
e69a66a1457b
child 3309
8c57262447d3
permissions
-rw-r--r--

7059047: EA: can't find initializing store with several CheckCastPP
Summary: Split adjust_escape_state() method into two methods to find initializing stores.
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 < nodes_size(), "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 < nodes_size(), "should be created already");
   118     add_node(noop_null, PointsToNode::JavaObject, PointsToNode::NoEscape, true);
   119   } else {
   120     _noop_null = _oop_null; // Should be initialized
   121   }
   122 }
   124 void ConnectionGraph::add_pointsto_edge(uint from_i, uint to_i) {
   125   PointsToNode *f = ptnode_adr(from_i);
   126   PointsToNode *t = ptnode_adr(to_i);
   128   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   129   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of PointsTo edge");
   130   assert(t->node_type() == PointsToNode::JavaObject, "invalid destination of PointsTo edge");
   131   add_edge(f, to_i, PointsToNode::PointsToEdge);
   132 }
   134 void ConnectionGraph::add_deferred_edge(uint from_i, uint to_i) {
   135   PointsToNode *f = ptnode_adr(from_i);
   136   PointsToNode *t = ptnode_adr(to_i);
   138   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   139   assert(f->node_type() == PointsToNode::LocalVar || f->node_type() == PointsToNode::Field, "invalid source of Deferred edge");
   140   assert(t->node_type() == PointsToNode::LocalVar || t->node_type() == PointsToNode::Field, "invalid destination of Deferred edge");
   141   // don't add a self-referential edge, this can occur during removal of
   142   // deferred edges
   143   if (from_i != to_i)
   144     add_edge(f, to_i, PointsToNode::DeferredEdge);
   145 }
   147 int ConnectionGraph::address_offset(Node* adr, PhaseTransform *phase) {
   148   const Type *adr_type = phase->type(adr);
   149   if (adr->is_AddP() && adr_type->isa_oopptr() == NULL &&
   150       adr->in(AddPNode::Address)->is_Proj() &&
   151       adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
   152     // We are computing a raw address for a store captured by an Initialize
   153     // compute an appropriate address type. AddP cases #3 and #5 (see below).
   154     int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
   155     assert(offs != Type::OffsetBot ||
   156            adr->in(AddPNode::Address)->in(0)->is_AllocateArray(),
   157            "offset must be a constant or it is initialization of array");
   158     return offs;
   159   }
   160   const TypePtr *t_ptr = adr_type->isa_ptr();
   161   assert(t_ptr != NULL, "must be a pointer type");
   162   return t_ptr->offset();
   163 }
   165 void ConnectionGraph::add_field_edge(uint from_i, uint to_i, int offset) {
   166   PointsToNode *f = ptnode_adr(from_i);
   167   PointsToNode *t = ptnode_adr(to_i);
   169   assert(f->node_type() != PointsToNode::UnknownType && t->node_type() != PointsToNode::UnknownType, "node types must be set");
   170   assert(f->node_type() == PointsToNode::JavaObject, "invalid destination of Field edge");
   171   assert(t->node_type() == PointsToNode::Field, "invalid destination of Field edge");
   172   assert (t->offset() == -1 || t->offset() == offset, "conflicting field offsets");
   173   t->set_offset(offset);
   175   add_edge(f, to_i, PointsToNode::FieldEdge);
   176 }
   178 void ConnectionGraph::set_escape_state(uint ni, PointsToNode::EscapeState es) {
   179   // Don't change non-escaping state of NULL pointer.
   180   if (ni == _noop_null || ni == _oop_null)
   181     return;
   182   PointsToNode *npt = ptnode_adr(ni);
   183   PointsToNode::EscapeState old_es = npt->escape_state();
   184   if (es > old_es)
   185     npt->set_escape_state(es);
   186 }
   188 void ConnectionGraph::add_node(Node *n, PointsToNode::NodeType nt,
   189                                PointsToNode::EscapeState es, bool done) {
   190   PointsToNode* ptadr = ptnode_adr(n->_idx);
   191   ptadr->_node = n;
   192   ptadr->set_node_type(nt);
   194   // inline set_escape_state(idx, es);
   195   PointsToNode::EscapeState old_es = ptadr->escape_state();
   196   if (es > old_es)
   197     ptadr->set_escape_state(es);
   199   if (done)
   200     _processed.set(n->_idx);
   201 }
   203 PointsToNode::EscapeState ConnectionGraph::escape_state(Node *n) {
   204   uint idx = n->_idx;
   205   PointsToNode::EscapeState es;
   207   // If we are still collecting or there were no non-escaping allocations
   208   // we don't know the answer yet
   209   if (_collecting)
   210     return PointsToNode::UnknownEscape;
   212   // if the node was created after the escape computation, return
   213   // UnknownEscape
   214   if (idx >= nodes_size())
   215     return PointsToNode::UnknownEscape;
   217   es = ptnode_adr(idx)->escape_state();
   219   // if we have already computed a value, return it
   220   if (es != PointsToNode::UnknownEscape &&
   221       ptnode_adr(idx)->node_type() == PointsToNode::JavaObject)
   222     return es;
   224   // PointsTo() calls n->uncast() which can return a new ideal node.
   225   if (n->uncast()->_idx >= nodes_size())
   226     return PointsToNode::UnknownEscape;
   228   PointsToNode::EscapeState orig_es = es;
   230   // compute max escape state of anything this node could point to
   231   for(VectorSetI i(PointsTo(n)); i.test() && es != PointsToNode::GlobalEscape; ++i) {
   232     uint pt = i.elem;
   233     PointsToNode::EscapeState pes = ptnode_adr(pt)->escape_state();
   234     if (pes > es)
   235       es = pes;
   236   }
   237   if (orig_es != es) {
   238     // cache the computed escape state
   239     assert(es > orig_es, "should have computed an escape state");
   240     set_escape_state(idx, es);
   241   } // orig_es could be PointsToNode::UnknownEscape
   242   return es;
   243 }
   245 VectorSet* ConnectionGraph::PointsTo(Node * n) {
   246   pt_ptset.Reset();
   247   pt_visited.Reset();
   248   pt_worklist.clear();
   250 #ifdef ASSERT
   251   Node *orig_n = n;
   252 #endif
   254   n = n->uncast();
   255   PointsToNode* npt = ptnode_adr(n->_idx);
   257   // If we have a JavaObject, return just that object
   258   if (npt->node_type() == PointsToNode::JavaObject) {
   259     pt_ptset.set(n->_idx);
   260     return &pt_ptset;
   261   }
   262 #ifdef ASSERT
   263   if (npt->_node == NULL) {
   264     if (orig_n != n)
   265       orig_n->dump();
   266     n->dump();
   267     assert(npt->_node != NULL, "unregistered node");
   268   }
   269 #endif
   270   pt_worklist.push(n->_idx);
   271   while(pt_worklist.length() > 0) {
   272     int ni = pt_worklist.pop();
   273     if (pt_visited.test_set(ni))
   274       continue;
   276     PointsToNode* pn = ptnode_adr(ni);
   277     // ensure that all inputs of a Phi have been processed
   278     assert(!_collecting || !pn->_node->is_Phi() || _processed.test(ni),"");
   280     int edges_processed = 0;
   281     uint e_cnt = pn->edge_count();
   282     for (uint e = 0; e < e_cnt; e++) {
   283       uint etgt = pn->edge_target(e);
   284       PointsToNode::EdgeType et = pn->edge_type(e);
   285       if (et == PointsToNode::PointsToEdge) {
   286         pt_ptset.set(etgt);
   287         edges_processed++;
   288       } else if (et == PointsToNode::DeferredEdge) {
   289         pt_worklist.push(etgt);
   290         edges_processed++;
   291       } else {
   292         assert(false,"neither PointsToEdge or DeferredEdge");
   293       }
   294     }
   295     if (edges_processed == 0) {
   296       // no deferred or pointsto edges found.  Assume the value was set
   297       // outside this method.  Add the phantom object to the pointsto set.
   298       pt_ptset.set(_phantom_object);
   299     }
   300   }
   301   return &pt_ptset;
   302 }
   304 void ConnectionGraph::remove_deferred(uint ni, GrowableArray<uint>* deferred_edges, VectorSet* visited) {
   305   // This method is most expensive during ConnectionGraph construction.
   306   // Reuse vectorSet and an additional growable array for deferred edges.
   307   deferred_edges->clear();
   308   visited->Reset();
   310   visited->set(ni);
   311   PointsToNode *ptn = ptnode_adr(ni);
   313   // Mark current edges as visited and move deferred edges to separate array.
   314   for (uint i = 0; i < ptn->edge_count(); ) {
   315     uint t = ptn->edge_target(i);
   316 #ifdef ASSERT
   317     assert(!visited->test_set(t), "expecting no duplications");
   318 #else
   319     visited->set(t);
   320 #endif
   321     if (ptn->edge_type(i) == PointsToNode::DeferredEdge) {
   322       ptn->remove_edge(t, PointsToNode::DeferredEdge);
   323       deferred_edges->append(t);
   324     } else {
   325       i++;
   326     }
   327   }
   328   for (int next = 0; next < deferred_edges->length(); ++next) {
   329     uint t = deferred_edges->at(next);
   330     PointsToNode *ptt = ptnode_adr(t);
   331     uint e_cnt = ptt->edge_count();
   332     for (uint e = 0; e < e_cnt; e++) {
   333       uint etgt = ptt->edge_target(e);
   334       if (visited->test_set(etgt))
   335         continue;
   337       PointsToNode::EdgeType et = ptt->edge_type(e);
   338       if (et == PointsToNode::PointsToEdge) {
   339         add_pointsto_edge(ni, etgt);
   340         if(etgt == _phantom_object) {
   341           // Special case - field set outside (globally escaping).
   342           set_escape_state(ni, PointsToNode::GlobalEscape);
   343         }
   344       } else if (et == PointsToNode::DeferredEdge) {
   345         deferred_edges->append(etgt);
   346       } else {
   347         assert(false,"invalid connection graph");
   348       }
   349     }
   350   }
   351 }
   354 //  Add an edge to node given by "to_i" from any field of adr_i whose offset
   355 //  matches "offset"  A deferred edge is added if to_i is a LocalVar, and
   356 //  a pointsto edge is added if it is a JavaObject
   358 void ConnectionGraph::add_edge_from_fields(uint adr_i, uint to_i, int offs) {
   359   PointsToNode* an = ptnode_adr(adr_i);
   360   PointsToNode* to = ptnode_adr(to_i);
   361   bool deferred = (to->node_type() == PointsToNode::LocalVar);
   363   for (uint fe = 0; fe < an->edge_count(); fe++) {
   364     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   365     int fi = an->edge_target(fe);
   366     PointsToNode* pf = ptnode_adr(fi);
   367     int po = pf->offset();
   368     if (po == offs || po == Type::OffsetBot || offs == Type::OffsetBot) {
   369       if (deferred)
   370         add_deferred_edge(fi, to_i);
   371       else
   372         add_pointsto_edge(fi, to_i);
   373     }
   374   }
   375 }
   377 // Add a deferred  edge from node given by "from_i" to any field of adr_i
   378 // whose offset matches "offset".
   379 void ConnectionGraph::add_deferred_edge_to_fields(uint from_i, uint adr_i, int offs) {
   380   PointsToNode* an = ptnode_adr(adr_i);
   381   bool is_alloc = an->_node->is_Allocate();
   382   for (uint fe = 0; fe < an->edge_count(); fe++) {
   383     assert(an->edge_type(fe) == PointsToNode::FieldEdge, "expecting a field edge");
   384     int fi = an->edge_target(fe);
   385     PointsToNode* pf = ptnode_adr(fi);
   386     int offset = pf->offset();
   387     if (!is_alloc) {
   388       // Assume the field was set outside this method if it is not Allocation
   389       add_pointsto_edge(fi, _phantom_object);
   390     }
   391     if (offset == offs || offset == Type::OffsetBot || offs == Type::OffsetBot) {
   392       add_deferred_edge(from_i, fi);
   393     }
   394   }
   395 }
   397 // Helper functions
   399 static Node* get_addp_base(Node *addp) {
   400   assert(addp->is_AddP(), "must be AddP");
   401   //
   402   // AddP cases for Base and Address inputs:
   403   // case #1. Direct object's field reference:
   404   //     Allocate
   405   //       |
   406   //     Proj #5 ( oop result )
   407   //       |
   408   //     CheckCastPP (cast to instance type)
   409   //      | |
   410   //     AddP  ( base == address )
   411   //
   412   // case #2. Indirect object's field reference:
   413   //      Phi
   414   //       |
   415   //     CastPP (cast to instance type)
   416   //      | |
   417   //     AddP  ( base == address )
   418   //
   419   // case #3. Raw object's field reference for Initialize node:
   420   //      Allocate
   421   //        |
   422   //      Proj #5 ( oop result )
   423   //  top   |
   424   //     \  |
   425   //     AddP  ( base == top )
   426   //
   427   // case #4. Array's element reference:
   428   //   {CheckCastPP | CastPP}
   429   //     |  | |
   430   //     |  AddP ( array's element offset )
   431   //     |  |
   432   //     AddP ( array's offset )
   433   //
   434   // case #5. Raw object's field reference for arraycopy stub call:
   435   //          The inline_native_clone() case when the arraycopy stub is called
   436   //          after the allocation before Initialize and CheckCastPP nodes.
   437   //      Allocate
   438   //        |
   439   //      Proj #5 ( oop result )
   440   //       | |
   441   //       AddP  ( base == address )
   442   //
   443   // case #6. Constant Pool, ThreadLocal, CastX2P or
   444   //          Raw object's field reference:
   445   //      {ConP, ThreadLocal, CastX2P, raw Load}
   446   //  top   |
   447   //     \  |
   448   //     AddP  ( base == top )
   449   //
   450   // case #7. Klass's field reference.
   451   //      LoadKlass
   452   //       | |
   453   //       AddP  ( base == address )
   454   //
   455   // case #8. narrow Klass's field reference.
   456   //      LoadNKlass
   457   //       |
   458   //      DecodeN
   459   //       | |
   460   //       AddP  ( base == address )
   461   //
   462   Node *base = addp->in(AddPNode::Base)->uncast();
   463   if (base->is_top()) { // The AddP case #3 and #6.
   464     base = addp->in(AddPNode::Address)->uncast();
   465     while (base->is_AddP()) {
   466       // Case #6 (unsafe access) may have several chained AddP nodes.
   467       assert(base->in(AddPNode::Base)->is_top(), "expected unsafe access address only");
   468       base = base->in(AddPNode::Address)->uncast();
   469     }
   470     assert(base->Opcode() == Op_ConP || base->Opcode() == Op_ThreadLocal ||
   471            base->Opcode() == Op_CastX2P || base->is_DecodeN() ||
   472            (base->is_Mem() && base->bottom_type() == TypeRawPtr::NOTNULL) ||
   473            (base->is_Proj() && base->in(0)->is_Allocate()), "sanity");
   474   }
   475   return base;
   476 }
   478 static Node* find_second_addp(Node* addp, Node* n) {
   479   assert(addp->is_AddP() && addp->outcnt() > 0, "Don't process dead nodes");
   481   Node* addp2 = addp->raw_out(0);
   482   if (addp->outcnt() == 1 && addp2->is_AddP() &&
   483       addp2->in(AddPNode::Base) == n &&
   484       addp2->in(AddPNode::Address) == addp) {
   486     assert(addp->in(AddPNode::Base) == n, "expecting the same base");
   487     //
   488     // Find array's offset to push it on worklist first and
   489     // as result process an array's element offset first (pushed second)
   490     // to avoid CastPP for the array's offset.
   491     // Otherwise the inserted CastPP (LocalVar) will point to what
   492     // the AddP (Field) points to. Which would be wrong since
   493     // the algorithm expects the CastPP has the same point as
   494     // as AddP's base CheckCastPP (LocalVar).
   495     //
   496     //    ArrayAllocation
   497     //     |
   498     //    CheckCastPP
   499     //     |
   500     //    memProj (from ArrayAllocation CheckCastPP)
   501     //     |  ||
   502     //     |  ||   Int (element index)
   503     //     |  ||    |   ConI (log(element size))
   504     //     |  ||    |   /
   505     //     |  ||   LShift
   506     //     |  ||  /
   507     //     |  AddP (array's element offset)
   508     //     |  |
   509     //     |  | ConI (array's offset: #12(32-bits) or #24(64-bits))
   510     //     | / /
   511     //     AddP (array's offset)
   512     //      |
   513     //     Load/Store (memory operation on array's element)
   514     //
   515     return addp2;
   516   }
   517   return NULL;
   518 }
   520 //
   521 // Adjust the type and inputs of an AddP which computes the
   522 // address of a field of an instance
   523 //
   524 bool ConnectionGraph::split_AddP(Node *addp, Node *base,  PhaseGVN  *igvn) {
   525   const TypeOopPtr *base_t = igvn->type(base)->isa_oopptr();
   526   assert(base_t != NULL && base_t->is_known_instance(), "expecting instance oopptr");
   527   const TypeOopPtr *t = igvn->type(addp)->isa_oopptr();
   528   if (t == NULL) {
   529     // We are computing a raw address for a store captured by an Initialize
   530     // compute an appropriate address type (cases #3 and #5).
   531     assert(igvn->type(addp) == TypeRawPtr::NOTNULL, "must be raw pointer");
   532     assert(addp->in(AddPNode::Address)->is_Proj(), "base of raw address must be result projection from allocation");
   533     intptr_t offs = (int)igvn->find_intptr_t_con(addp->in(AddPNode::Offset), Type::OffsetBot);
   534     assert(offs != Type::OffsetBot, "offset must be a constant");
   535     t = base_t->add_offset(offs)->is_oopptr();
   536   }
   537   int inst_id =  base_t->instance_id();
   538   assert(!t->is_known_instance() || t->instance_id() == inst_id,
   539                              "old type must be non-instance or match new type");
   541   // The type 't' could be subclass of 'base_t'.
   542   // As result t->offset() could be large then base_t's size and it will
   543   // cause the failure in add_offset() with narrow oops since TypeOopPtr()
   544   // constructor verifies correctness of the offset.
   545   //
   546   // It could happened on subclass's branch (from the type profiling
   547   // inlining) which was not eliminated during parsing since the exactness
   548   // of the allocation type was not propagated to the subclass type check.
   549   //
   550   // Or the type 't' could be not related to 'base_t' at all.
   551   // It could happened when CHA type is different from MDO type on a dead path
   552   // (for example, from instanceof check) which is not collapsed during parsing.
   553   //
   554   // Do nothing for such AddP node and don't process its users since
   555   // this code branch will go away.
   556   //
   557   if (!t->is_known_instance() &&
   558       !base_t->klass()->is_subtype_of(t->klass())) {
   559      return false; // bail out
   560   }
   562   const TypeOopPtr *tinst = base_t->add_offset(t->offset())->is_oopptr();
   563   // Do NOT remove the next line: ensure a new alias index is allocated
   564   // for the instance type. Note: C++ will not remove it since the call
   565   // has side effect.
   566   int alias_idx = _compile->get_alias_index(tinst);
   567   igvn->set_type(addp, tinst);
   568   // record the allocation in the node map
   569   assert(ptnode_adr(addp->_idx)->_node != NULL, "should be registered");
   570   set_map(addp->_idx, get_map(base->_idx));
   572   // Set addp's Base and Address to 'base'.
   573   Node *abase = addp->in(AddPNode::Base);
   574   Node *adr   = addp->in(AddPNode::Address);
   575   if (adr->is_Proj() && adr->in(0)->is_Allocate() &&
   576       adr->in(0)->_idx == (uint)inst_id) {
   577     // Skip AddP cases #3 and #5.
   578   } else {
   579     assert(!abase->is_top(), "sanity"); // AddP case #3
   580     if (abase != base) {
   581       igvn->hash_delete(addp);
   582       addp->set_req(AddPNode::Base, base);
   583       if (abase == adr) {
   584         addp->set_req(AddPNode::Address, base);
   585       } else {
   586         // AddP case #4 (adr is array's element offset AddP node)
   587 #ifdef ASSERT
   588         const TypeOopPtr *atype = igvn->type(adr)->isa_oopptr();
   589         assert(adr->is_AddP() && atype != NULL &&
   590                atype->instance_id() == inst_id, "array's element offset should be processed first");
   591 #endif
   592       }
   593       igvn->hash_insert(addp);
   594     }
   595   }
   596   // Put on IGVN worklist since at least addp's type was changed above.
   597   record_for_optimizer(addp);
   598   return true;
   599 }
   601 //
   602 // Create a new version of orig_phi if necessary. Returns either the newly
   603 // created phi or an existing phi.  Sets create_new to indicate whether a new
   604 // phi was created.  Cache the last newly created phi in the node map.
   605 //
   606 PhiNode *ConnectionGraph::create_split_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn, bool &new_created) {
   607   Compile *C = _compile;
   608   new_created = false;
   609   int phi_alias_idx = C->get_alias_index(orig_phi->adr_type());
   610   // nothing to do if orig_phi is bottom memory or matches alias_idx
   611   if (phi_alias_idx == alias_idx) {
   612     return orig_phi;
   613   }
   614   // Have we recently created a Phi for this alias index?
   615   PhiNode *result = get_map_phi(orig_phi->_idx);
   616   if (result != NULL && C->get_alias_index(result->adr_type()) == alias_idx) {
   617     return result;
   618   }
   619   // Previous check may fail when the same wide memory Phi was split into Phis
   620   // for different memory slices. Search all Phis for this region.
   621   if (result != NULL) {
   622     Node* region = orig_phi->in(0);
   623     for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
   624       Node* phi = region->fast_out(i);
   625       if (phi->is_Phi() &&
   626           C->get_alias_index(phi->as_Phi()->adr_type()) == alias_idx) {
   627         assert(phi->_idx >= nodes_size(), "only new Phi per instance memory slice");
   628         return phi->as_Phi();
   629       }
   630     }
   631   }
   632   if ((int)C->unique() + 2*NodeLimitFudgeFactor > MaxNodeLimit) {
   633     if (C->do_escape_analysis() == true && !C->failing()) {
   634       // Retry compilation without escape analysis.
   635       // If this is the first failure, the sentinel string will "stick"
   636       // to the Compile object, and the C2Compiler will see it and retry.
   637       C->record_failure(C2Compiler::retry_no_escape_analysis());
   638     }
   639     return NULL;
   640   }
   641   orig_phi_worklist.append_if_missing(orig_phi);
   642   const TypePtr *atype = C->get_adr_type(alias_idx);
   643   result = PhiNode::make(orig_phi->in(0), NULL, Type::MEMORY, atype);
   644   C->copy_node_notes_to(result, orig_phi);
   645   igvn->set_type(result, result->bottom_type());
   646   record_for_optimizer(result);
   648   debug_only(Node* pn = ptnode_adr(orig_phi->_idx)->_node;)
   649   assert(pn == NULL || pn == orig_phi, "wrong node");
   650   set_map(orig_phi->_idx, result);
   651   ptnode_adr(orig_phi->_idx)->_node = orig_phi;
   653   new_created = true;
   654   return result;
   655 }
   657 //
   658 // Return a new version of Memory Phi "orig_phi" with the inputs having the
   659 // specified alias index.
   660 //
   661 PhiNode *ConnectionGraph::split_memory_phi(PhiNode *orig_phi, int alias_idx, GrowableArray<PhiNode *>  &orig_phi_worklist, PhaseGVN  *igvn) {
   663   assert(alias_idx != Compile::AliasIdxBot, "can't split out bottom memory");
   664   Compile *C = _compile;
   665   bool new_phi_created;
   666   PhiNode *result = create_split_phi(orig_phi, alias_idx, orig_phi_worklist, igvn, new_phi_created);
   667   if (!new_phi_created) {
   668     return result;
   669   }
   671   GrowableArray<PhiNode *>  phi_list;
   672   GrowableArray<uint>  cur_input;
   674   PhiNode *phi = orig_phi;
   675   uint idx = 1;
   676   bool finished = false;
   677   while(!finished) {
   678     while (idx < phi->req()) {
   679       Node *mem = find_inst_mem(phi->in(idx), alias_idx, orig_phi_worklist, igvn);
   680       if (mem != NULL && mem->is_Phi()) {
   681         PhiNode *newphi = create_split_phi(mem->as_Phi(), alias_idx, orig_phi_worklist, igvn, new_phi_created);
   682         if (new_phi_created) {
   683           // found an phi for which we created a new split, push current one on worklist and begin
   684           // processing new one
   685           phi_list.push(phi);
   686           cur_input.push(idx);
   687           phi = mem->as_Phi();
   688           result = newphi;
   689           idx = 1;
   690           continue;
   691         } else {
   692           mem = newphi;
   693         }
   694       }
   695       if (C->failing()) {
   696         return NULL;
   697       }
   698       result->set_req(idx++, mem);
   699     }
   700 #ifdef ASSERT
   701     // verify that the new Phi has an input for each input of the original
   702     assert( phi->req() == result->req(), "must have same number of inputs.");
   703     assert( result->in(0) != NULL && result->in(0) == phi->in(0), "regions must match");
   704 #endif
   705     // Check if all new phi's inputs have specified alias index.
   706     // Otherwise use old phi.
   707     for (uint i = 1; i < phi->req(); i++) {
   708       Node* in = result->in(i);
   709       assert((phi->in(i) == NULL) == (in == NULL), "inputs must correspond.");
   710     }
   711     // we have finished processing a Phi, see if there are any more to do
   712     finished = (phi_list.length() == 0 );
   713     if (!finished) {
   714       phi = phi_list.pop();
   715       idx = cur_input.pop();
   716       PhiNode *prev_result = get_map_phi(phi->_idx);
   717       prev_result->set_req(idx++, result);
   718       result = prev_result;
   719     }
   720   }
   721   return result;
   722 }
   725 //
   726 // The next methods are derived from methods in MemNode.
   727 //
   728 static Node *step_through_mergemem(MergeMemNode *mmem, int alias_idx, const TypeOopPtr *toop) {
   729   Node *mem = mmem;
   730   // TypeOopPtr::NOTNULL+any is an OOP with unknown offset - generally
   731   // means an array I have not precisely typed yet.  Do not do any
   732   // alias stuff with it any time soon.
   733   if( toop->base() != Type::AnyPtr &&
   734       !(toop->klass() != NULL &&
   735         toop->klass()->is_java_lang_Object() &&
   736         toop->offset() == Type::OffsetBot) ) {
   737     mem = mmem->memory_at(alias_idx);
   738     // Update input if it is progress over what we have now
   739   }
   740   return mem;
   741 }
   743 //
   744 // Move memory users to their memory slices.
   745 //
   746 void ConnectionGraph::move_inst_mem(Node* n, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *igvn) {
   747   Compile* C = _compile;
   749   const TypePtr* tp = igvn->type(n->in(MemNode::Address))->isa_ptr();
   750   assert(tp != NULL, "ptr type");
   751   int alias_idx = C->get_alias_index(tp);
   752   int general_idx = C->get_general_index(alias_idx);
   754   // Move users first
   755   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
   756     Node* use = n->fast_out(i);
   757     if (use->is_MergeMem()) {
   758       MergeMemNode* mmem = use->as_MergeMem();
   759       assert(n == mmem->memory_at(alias_idx), "should be on instance memory slice");
   760       if (n != mmem->memory_at(general_idx) || alias_idx == general_idx) {
   761         continue; // Nothing to do
   762       }
   763       // Replace previous general reference to mem node.
   764       uint orig_uniq = C->unique();
   765       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   766       assert(orig_uniq == C->unique(), "no new nodes");
   767       mmem->set_memory_at(general_idx, m);
   768       --imax;
   769       --i;
   770     } else if (use->is_MemBar()) {
   771       assert(!use->is_Initialize(), "initializing stores should not be moved");
   772       if (use->req() > MemBarNode::Precedent &&
   773           use->in(MemBarNode::Precedent) == n) {
   774         // Don't move related membars.
   775         record_for_optimizer(use);
   776         continue;
   777       }
   778       tp = use->as_MemBar()->adr_type()->isa_ptr();
   779       if (tp != NULL && C->get_alias_index(tp) == alias_idx ||
   780           alias_idx == general_idx) {
   781         continue; // Nothing to do
   782       }
   783       // Move to general memory slice.
   784       uint orig_uniq = C->unique();
   785       Node* m = find_inst_mem(n, general_idx, orig_phis, igvn);
   786       assert(orig_uniq == C->unique(), "no new nodes");
   787       igvn->hash_delete(use);
   788       imax -= use->replace_edge(n, m);
   789       igvn->hash_insert(use);
   790       record_for_optimizer(use);
   791       --i;
   792 #ifdef ASSERT
   793     } else if (use->is_Mem()) {
   794       if (use->Opcode() == Op_StoreCM && use->in(MemNode::OopStore) == n) {
   795         // Don't move related cardmark.
   796         continue;
   797       }
   798       // Memory nodes should have new memory input.
   799       tp = igvn->type(use->in(MemNode::Address))->isa_ptr();
   800       assert(tp != NULL, "ptr type");
   801       int idx = C->get_alias_index(tp);
   802       assert(get_map(use->_idx) != NULL || idx == alias_idx,
   803              "Following memory nodes should have new memory input or be on the same memory slice");
   804     } else if (use->is_Phi()) {
   805       // Phi nodes should be split and moved already.
   806       tp = use->as_Phi()->adr_type()->isa_ptr();
   807       assert(tp != NULL, "ptr type");
   808       int idx = C->get_alias_index(tp);
   809       assert(idx == alias_idx, "Following Phi nodes should be on the same memory slice");
   810     } else {
   811       use->dump();
   812       assert(false, "should not be here");
   813 #endif
   814     }
   815   }
   816 }
   818 //
   819 // Search memory chain of "mem" to find a MemNode whose address
   820 // is the specified alias index.
   821 //
   822 Node* ConnectionGraph::find_inst_mem(Node *orig_mem, int alias_idx, GrowableArray<PhiNode *>  &orig_phis, PhaseGVN *phase) {
   823   if (orig_mem == NULL)
   824     return orig_mem;
   825   Compile* C = phase->C;
   826   const TypeOopPtr *toop = C->get_adr_type(alias_idx)->isa_oopptr();
   827   bool is_instance = (toop != NULL) && toop->is_known_instance();
   828   Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
   829   Node *prev = NULL;
   830   Node *result = orig_mem;
   831   while (prev != result) {
   832     prev = result;
   833     if (result == start_mem)
   834       break;  // hit one of our sentinels
   835     if (result->is_Mem()) {
   836       const Type *at = phase->type(result->in(MemNode::Address));
   837       if (at == Type::TOP)
   838         break; // Dead
   839       assert (at->isa_ptr() != NULL, "pointer type required.");
   840       int idx = C->get_alias_index(at->is_ptr());
   841       if (idx == alias_idx)
   842         break; // Found
   843       if (!is_instance && (at->isa_oopptr() == NULL ||
   844                            !at->is_oopptr()->is_known_instance())) {
   845         break; // Do not skip store to general memory slice.
   846       }
   847       result = result->in(MemNode::Memory);
   848     }
   849     if (!is_instance)
   850       continue;  // don't search further for non-instance types
   851     // skip over a call which does not affect this memory slice
   852     if (result->is_Proj() && result->as_Proj()->_con == TypeFunc::Memory) {
   853       Node *proj_in = result->in(0);
   854       if (proj_in->is_Allocate() && proj_in->_idx == (uint)toop->instance_id()) {
   855         break;  // hit one of our sentinels
   856       } else if (proj_in->is_Call()) {
   857         CallNode *call = proj_in->as_Call();
   858         if (!call->may_modify(toop, phase)) {
   859           result = call->in(TypeFunc::Memory);
   860         }
   861       } else if (proj_in->is_Initialize()) {
   862         AllocateNode* alloc = proj_in->as_Initialize()->allocation();
   863         // Stop if this is the initialization for the object instance which
   864         // which contains this memory slice, otherwise skip over it.
   865         if (alloc == NULL || alloc->_idx != (uint)toop->instance_id()) {
   866           result = proj_in->in(TypeFunc::Memory);
   867         }
   868       } else if (proj_in->is_MemBar()) {
   869         result = proj_in->in(TypeFunc::Memory);
   870       }
   871     } else if (result->is_MergeMem()) {
   872       MergeMemNode *mmem = result->as_MergeMem();
   873       result = step_through_mergemem(mmem, alias_idx, toop);
   874       if (result == mmem->base_memory()) {
   875         // Didn't find instance memory, search through general slice recursively.
   876         result = mmem->memory_at(C->get_general_index(alias_idx));
   877         result = find_inst_mem(result, alias_idx, orig_phis, phase);
   878         if (C->failing()) {
   879           return NULL;
   880         }
   881         mmem->set_memory_at(alias_idx, result);
   882       }
   883     } else if (result->is_Phi() &&
   884                C->get_alias_index(result->as_Phi()->adr_type()) != alias_idx) {
   885       Node *un = result->as_Phi()->unique_input(phase);
   886       if (un != NULL) {
   887         orig_phis.append_if_missing(result->as_Phi());
   888         result = un;
   889       } else {
   890         break;
   891       }
   892     } else if (result->is_ClearArray()) {
   893       if (!ClearArrayNode::step_through(&result, (uint)toop->instance_id(), phase)) {
   894         // Can not bypass initialization of the instance
   895         // we are looking for.
   896         break;
   897       }
   898       // Otherwise skip it (the call updated 'result' value).
   899     } else if (result->Opcode() == Op_SCMemProj) {
   900       assert(result->in(0)->is_LoadStore(), "sanity");
   901       const Type *at = phase->type(result->in(0)->in(MemNode::Address));
   902       if (at != Type::TOP) {
   903         assert (at->isa_ptr() != NULL, "pointer type required.");
   904         int idx = C->get_alias_index(at->is_ptr());
   905         assert(idx != alias_idx, "Object is not scalar replaceable if a LoadStore node access its field");
   906         break;
   907       }
   908       result = result->in(0)->in(MemNode::Memory);
   909     }
   910   }
   911   if (result->is_Phi()) {
   912     PhiNode *mphi = result->as_Phi();
   913     assert(mphi->bottom_type() == Type::MEMORY, "memory phi required");
   914     const TypePtr *t = mphi->adr_type();
   915     if (!is_instance) {
   916       // Push all non-instance Phis on the orig_phis worklist to update inputs
   917       // during Phase 4 if needed.
   918       orig_phis.append_if_missing(mphi);
   919     } else if (C->get_alias_index(t) != alias_idx) {
   920       // Create a new Phi with the specified alias index type.
   921       result = split_memory_phi(mphi, alias_idx, orig_phis, phase);
   922     }
   923   }
   924   // the result is either MemNode, PhiNode, InitializeNode.
   925   return result;
   926 }
   928 //
   929 //  Convert the types of unescaped object to instance types where possible,
   930 //  propagate the new type information through the graph, and update memory
   931 //  edges and MergeMem inputs to reflect the new type.
   932 //
   933 //  We start with allocations (and calls which may be allocations)  on alloc_worklist.
   934 //  The processing is done in 4 phases:
   935 //
   936 //  Phase 1:  Process possible allocations from alloc_worklist.  Create instance
   937 //            types for the CheckCastPP for allocations where possible.
   938 //            Propagate the the new types through users as follows:
   939 //               casts and Phi:  push users on alloc_worklist
   940 //               AddP:  cast Base and Address inputs to the instance type
   941 //                      push any AddP users on alloc_worklist and push any memnode
   942 //                      users onto memnode_worklist.
   943 //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
   944 //            search the Memory chain for a store with the appropriate type
   945 //            address type.  If a Phi is found, create a new version with
   946 //            the appropriate memory slices from each of the Phi inputs.
   947 //            For stores, process the users as follows:
   948 //               MemNode:  push on memnode_worklist
   949 //               MergeMem: push on mergemem_worklist
   950 //  Phase 3:  Process MergeMem nodes from mergemem_worklist.  Walk each memory slice
   951 //            moving the first node encountered of each  instance type to the
   952 //            the input corresponding to its alias index.
   953 //            appropriate memory slice.
   954 //  Phase 4:  Update the inputs of non-instance memory Phis and the Memory input of memnodes.
   955 //
   956 // In the following example, the CheckCastPP nodes are the cast of allocation
   957 // results and the allocation of node 29 is unescaped and eligible to be an
   958 // instance type.
   959 //
   960 // We start with:
   961 //
   962 //     7 Parm #memory
   963 //    10  ConI  "12"
   964 //    19  CheckCastPP   "Foo"
   965 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   966 //    29  CheckCastPP   "Foo"
   967 //    30  AddP  _ 29 29 10  Foo+12  alias_index=4
   968 //
   969 //    40  StoreP  25   7  20   ... alias_index=4
   970 //    50  StoreP  35  40  30   ... alias_index=4
   971 //    60  StoreP  45  50  20   ... alias_index=4
   972 //    70  LoadP    _  60  30   ... alias_index=4
   973 //    80  Phi     75  50  60   Memory alias_index=4
   974 //    90  LoadP    _  80  30   ... alias_index=4
   975 //   100  LoadP    _  80  20   ... alias_index=4
   976 //
   977 //
   978 // Phase 1 creates an instance type for node 29 assigning it an instance id of 24
   979 // and creating a new alias index for node 30.  This gives:
   980 //
   981 //     7 Parm #memory
   982 //    10  ConI  "12"
   983 //    19  CheckCastPP   "Foo"
   984 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
   985 //    29  CheckCastPP   "Foo"  iid=24
   986 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
   987 //
   988 //    40  StoreP  25   7  20   ... alias_index=4
   989 //    50  StoreP  35  40  30   ... alias_index=6
   990 //    60  StoreP  45  50  20   ... alias_index=4
   991 //    70  LoadP    _  60  30   ... alias_index=6
   992 //    80  Phi     75  50  60   Memory alias_index=4
   993 //    90  LoadP    _  80  30   ... alias_index=6
   994 //   100  LoadP    _  80  20   ... alias_index=4
   995 //
   996 // In phase 2, new memory inputs are computed for the loads and stores,
   997 // And a new version of the phi is created.  In phase 4, the inputs to
   998 // node 80 are updated and then the memory nodes are updated with the
   999 // values computed in phase 2.  This results in:
  1000 //
  1001 //     7 Parm #memory
  1002 //    10  ConI  "12"
  1003 //    19  CheckCastPP   "Foo"
  1004 //    20  AddP  _ 19 19 10  Foo+12  alias_index=4
  1005 //    29  CheckCastPP   "Foo"  iid=24
  1006 //    30  AddP  _ 29 29 10  Foo+12  alias_index=6  iid=24
  1007 //
  1008 //    40  StoreP  25  7   20   ... alias_index=4
  1009 //    50  StoreP  35  7   30   ... alias_index=6
  1010 //    60  StoreP  45  40  20   ... alias_index=4
  1011 //    70  LoadP    _  50  30   ... alias_index=6
  1012 //    80  Phi     75  40  60   Memory alias_index=4
  1013 //   120  Phi     75  50  50   Memory alias_index=6
  1014 //    90  LoadP    _ 120  30   ... alias_index=6
  1015 //   100  LoadP    _  80  20   ... alias_index=4
  1016 //
  1017 void ConnectionGraph::split_unique_types(GrowableArray<Node *>  &alloc_worklist) {
  1018   GrowableArray<Node *>  memnode_worklist;
  1019   GrowableArray<PhiNode *>  orig_phis;
  1021   PhaseIterGVN  *igvn = _igvn;
  1022   uint new_index_start = (uint) _compile->num_alias_types();
  1023   Arena* arena = Thread::current()->resource_area();
  1024   VectorSet visited(arena);
  1027   //  Phase 1:  Process possible allocations from alloc_worklist.
  1028   //  Create instance types for the CheckCastPP for allocations where possible.
  1029   //
  1030   // (Note: don't forget to change the order of the second AddP node on
  1031   //  the alloc_worklist if the order of the worklist processing is changed,
  1032   //  see the comment in find_second_addp().)
  1033   //
  1034   while (alloc_worklist.length() != 0) {
  1035     Node *n = alloc_worklist.pop();
  1036     uint ni = n->_idx;
  1037     const TypeOopPtr* tinst = NULL;
  1038     if (n->is_Call()) {
  1039       CallNode *alloc = n->as_Call();
  1040       // copy escape information to call node
  1041       PointsToNode* ptn = ptnode_adr(alloc->_idx);
  1042       PointsToNode::EscapeState es = escape_state(alloc);
  1043       // We have an allocation or call which returns a Java object,
  1044       // see if it is unescaped.
  1045       if (es != PointsToNode::NoEscape || !ptn->scalar_replaceable())
  1046         continue;
  1048       // Find CheckCastPP for the allocate or for the return value of a call
  1049       n = alloc->result_cast();
  1050       if (n == NULL) {            // No uses except Initialize node
  1051         if (alloc->is_Allocate()) {
  1052           // Set the scalar_replaceable flag for allocation
  1053           // so it could be eliminated if it has no uses.
  1054           alloc->as_Allocate()->_is_scalar_replaceable = true;
  1056         continue;
  1058       if (!n->is_CheckCastPP()) { // not unique CheckCastPP.
  1059         assert(!alloc->is_Allocate(), "allocation should have unique type");
  1060         continue;
  1063       // The inline code for Object.clone() casts the allocation result to
  1064       // java.lang.Object and then to the actual type of the allocated
  1065       // object. Detect this case and use the second cast.
  1066       // Also detect j.l.reflect.Array.newInstance(jobject, jint) case when
  1067       // the allocation result is cast to java.lang.Object and then
  1068       // to the actual Array type.
  1069       if (alloc->is_Allocate() && n->as_Type()->type() == TypeInstPtr::NOTNULL
  1070           && (alloc->is_AllocateArray() ||
  1071               igvn->type(alloc->in(AllocateNode::KlassNode)) != TypeKlassPtr::OBJECT)) {
  1072         Node *cast2 = NULL;
  1073         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1074           Node *use = n->fast_out(i);
  1075           if (use->is_CheckCastPP()) {
  1076             cast2 = use;
  1077             break;
  1080         if (cast2 != NULL) {
  1081           n = cast2;
  1082         } else {
  1083           // Non-scalar replaceable if the allocation type is unknown statically
  1084           // (reflection allocation), the object can't be restored during
  1085           // deoptimization without precise type.
  1086           continue;
  1089       if (alloc->is_Allocate()) {
  1090         // Set the scalar_replaceable flag for allocation
  1091         // so it could be eliminated.
  1092         alloc->as_Allocate()->_is_scalar_replaceable = true;
  1094       set_escape_state(n->_idx, es); // CheckCastPP escape state
  1095       // in order for an object to be scalar-replaceable, it must be:
  1096       //   - a direct allocation (not a call returning an object)
  1097       //   - non-escaping
  1098       //   - eligible to be a unique type
  1099       //   - not determined to be ineligible by escape analysis
  1100       assert(ptnode_adr(alloc->_idx)->_node != NULL &&
  1101              ptnode_adr(n->_idx)->_node != NULL, "should be registered");
  1102       set_map(alloc->_idx, n);
  1103       set_map(n->_idx, alloc);
  1104       const TypeOopPtr *t = igvn->type(n)->isa_oopptr();
  1105       if (t == NULL)
  1106         continue;  // not a TypeOopPtr
  1107       tinst = t->cast_to_exactness(true)->is_oopptr()->cast_to_instance_id(ni);
  1108       igvn->hash_delete(n);
  1109       igvn->set_type(n,  tinst);
  1110       n->raise_bottom_type(tinst);
  1111       igvn->hash_insert(n);
  1112       record_for_optimizer(n);
  1113       if (alloc->is_Allocate() && (t->isa_instptr() || t->isa_aryptr())) {
  1115         // First, put on the worklist all Field edges from Connection Graph
  1116         // which is more accurate then putting immediate users from Ideal Graph.
  1117         for (uint e = 0; e < ptn->edge_count(); e++) {
  1118           Node *use = ptnode_adr(ptn->edge_target(e))->_node;
  1119           assert(ptn->edge_type(e) == PointsToNode::FieldEdge && use->is_AddP(),
  1120                  "only AddP nodes are Field edges in CG");
  1121           if (use->outcnt() > 0) { // Don't process dead nodes
  1122             Node* addp2 = find_second_addp(use, use->in(AddPNode::Base));
  1123             if (addp2 != NULL) {
  1124               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1125               alloc_worklist.append_if_missing(addp2);
  1127             alloc_worklist.append_if_missing(use);
  1131         // An allocation may have an Initialize which has raw stores. Scan
  1132         // the users of the raw allocation result and push AddP users
  1133         // on alloc_worklist.
  1134         Node *raw_result = alloc->proj_out(TypeFunc::Parms);
  1135         assert (raw_result != NULL, "must have an allocation result");
  1136         for (DUIterator_Fast imax, i = raw_result->fast_outs(imax); i < imax; i++) {
  1137           Node *use = raw_result->fast_out(i);
  1138           if (use->is_AddP() && use->outcnt() > 0) { // Don't process dead nodes
  1139             Node* addp2 = find_second_addp(use, raw_result);
  1140             if (addp2 != NULL) {
  1141               assert(alloc->is_AllocateArray(),"array allocation was expected");
  1142               alloc_worklist.append_if_missing(addp2);
  1144             alloc_worklist.append_if_missing(use);
  1145           } else if (use->is_MemBar()) {
  1146             memnode_worklist.append_if_missing(use);
  1150     } else if (n->is_AddP()) {
  1151       VectorSet* ptset = PointsTo(get_addp_base(n));
  1152       assert(ptset->Size() == 1, "AddP address is unique");
  1153       uint elem = ptset->getelem(); // Allocation node's index
  1154       if (elem == _phantom_object) {
  1155         assert(false, "escaped allocation");
  1156         continue; // Assume the value was set outside this method.
  1158       Node *base = get_map(elem);  // CheckCastPP node
  1159       if (!split_AddP(n, base, igvn)) continue; // wrong type from dead path
  1160       tinst = igvn->type(base)->isa_oopptr();
  1161     } else if (n->is_Phi() ||
  1162                n->is_CheckCastPP() ||
  1163                n->is_EncodeP() ||
  1164                n->is_DecodeN() ||
  1165                (n->is_ConstraintCast() && n->Opcode() == Op_CastPP)) {
  1166       if (visited.test_set(n->_idx)) {
  1167         assert(n->is_Phi(), "loops only through Phi's");
  1168         continue;  // already processed
  1170       VectorSet* ptset = PointsTo(n);
  1171       if (ptset->Size() == 1) {
  1172         uint elem = ptset->getelem(); // Allocation node's index
  1173         if (elem == _phantom_object) {
  1174           assert(false, "escaped allocation");
  1175           continue; // Assume the value was set outside this method.
  1177         Node *val = get_map(elem);   // CheckCastPP node
  1178         TypeNode *tn = n->as_Type();
  1179         tinst = igvn->type(val)->isa_oopptr();
  1180         assert(tinst != NULL && tinst->is_known_instance() &&
  1181                (uint)tinst->instance_id() == elem , "instance type expected.");
  1183         const Type *tn_type = igvn->type(tn);
  1184         const TypeOopPtr *tn_t;
  1185         if (tn_type->isa_narrowoop()) {
  1186           tn_t = tn_type->make_ptr()->isa_oopptr();
  1187         } else {
  1188           tn_t = tn_type->isa_oopptr();
  1191         if (tn_t != NULL && tinst->klass()->is_subtype_of(tn_t->klass())) {
  1192           if (tn_type->isa_narrowoop()) {
  1193             tn_type = tinst->make_narrowoop();
  1194           } else {
  1195             tn_type = tinst;
  1197           igvn->hash_delete(tn);
  1198           igvn->set_type(tn, tn_type);
  1199           tn->set_type(tn_type);
  1200           igvn->hash_insert(tn);
  1201           record_for_optimizer(n);
  1202         } else {
  1203           assert(tn_type == TypePtr::NULL_PTR ||
  1204                  tn_t != NULL && !tinst->klass()->is_subtype_of(tn_t->klass()),
  1205                  "unexpected type");
  1206           continue; // Skip dead path with different type
  1209     } else {
  1210       debug_only(n->dump();)
  1211       assert(false, "EA: unexpected node");
  1212       continue;
  1214     // push allocation's users on appropriate worklist
  1215     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1216       Node *use = n->fast_out(i);
  1217       if(use->is_Mem() && use->in(MemNode::Address) == n) {
  1218         // Load/store to instance's field
  1219         memnode_worklist.append_if_missing(use);
  1220       } else if (use->is_MemBar()) {
  1221         memnode_worklist.append_if_missing(use);
  1222       } else if (use->is_AddP() && use->outcnt() > 0) { // No dead nodes
  1223         Node* addp2 = find_second_addp(use, n);
  1224         if (addp2 != NULL) {
  1225           alloc_worklist.append_if_missing(addp2);
  1227         alloc_worklist.append_if_missing(use);
  1228       } else if (use->is_Phi() ||
  1229                  use->is_CheckCastPP() ||
  1230                  use->is_EncodeP() ||
  1231                  use->is_DecodeN() ||
  1232                  (use->is_ConstraintCast() && use->Opcode() == Op_CastPP)) {
  1233         alloc_worklist.append_if_missing(use);
  1234 #ifdef ASSERT
  1235       } else if (use->is_Mem()) {
  1236         assert(use->in(MemNode::Address) != n, "EA: missing allocation reference path");
  1237       } else if (use->is_MergeMem()) {
  1238         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1239       } else if (use->is_SafePoint()) {
  1240         // Look for MergeMem nodes for calls which reference unique allocation
  1241         // (through CheckCastPP nodes) even for debug info.
  1242         Node* m = use->in(TypeFunc::Memory);
  1243         if (m->is_MergeMem()) {
  1244           assert(_mergemem_worklist.contains(m->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1246       } else {
  1247         uint op = use->Opcode();
  1248         if (!(op == Op_CmpP || op == Op_Conv2B ||
  1249               op == Op_CastP2X || op == Op_StoreCM ||
  1250               op == Op_FastLock || op == Op_AryEq || op == Op_StrComp ||
  1251               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1252           n->dump();
  1253           use->dump();
  1254           assert(false, "EA: missing allocation reference path");
  1256 #endif
  1261   // New alias types were created in split_AddP().
  1262   uint new_index_end = (uint) _compile->num_alias_types();
  1264   //  Phase 2:  Process MemNode's from memnode_worklist. compute new address type and
  1265   //            compute new values for Memory inputs  (the Memory inputs are not
  1266   //            actually updated until phase 4.)
  1267   if (memnode_worklist.length() == 0)
  1268     return;  // nothing to do
  1270   while (memnode_worklist.length() != 0) {
  1271     Node *n = memnode_worklist.pop();
  1272     if (visited.test_set(n->_idx))
  1273       continue;
  1274     if (n->is_Phi() || n->is_ClearArray()) {
  1275       // we don't need to do anything, but the users must be pushed
  1276     } else if (n->is_MemBar()) { // Initialize, MemBar nodes
  1277       // we don't need to do anything, but the users must be pushed
  1278       n = n->as_MemBar()->proj_out(TypeFunc::Memory);
  1279       if (n == NULL)
  1280         continue;
  1281     } else {
  1282       assert(n->is_Mem(), "memory node required.");
  1283       Node *addr = n->in(MemNode::Address);
  1284       const Type *addr_t = igvn->type(addr);
  1285       if (addr_t == Type::TOP)
  1286         continue;
  1287       assert (addr_t->isa_ptr() != NULL, "pointer type required.");
  1288       int alias_idx = _compile->get_alias_index(addr_t->is_ptr());
  1289       assert ((uint)alias_idx < new_index_end, "wrong alias index");
  1290       Node *mem = find_inst_mem(n->in(MemNode::Memory), alias_idx, orig_phis, igvn);
  1291       if (_compile->failing()) {
  1292         return;
  1294       if (mem != n->in(MemNode::Memory)) {
  1295         // We delay the memory edge update since we need old one in
  1296         // MergeMem code below when instances memory slices are separated.
  1297         debug_only(Node* pn = ptnode_adr(n->_idx)->_node;)
  1298         assert(pn == NULL || pn == n, "wrong node");
  1299         set_map(n->_idx, mem);
  1300         ptnode_adr(n->_idx)->_node = n;
  1302       if (n->is_Load()) {
  1303         continue;  // don't push users
  1304       } else if (n->is_LoadStore()) {
  1305         // get the memory projection
  1306         for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1307           Node *use = n->fast_out(i);
  1308           if (use->Opcode() == Op_SCMemProj) {
  1309             n = use;
  1310             break;
  1313         assert(n->Opcode() == Op_SCMemProj, "memory projection required");
  1316     // push user on appropriate worklist
  1317     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1318       Node *use = n->fast_out(i);
  1319       if (use->is_Phi() || use->is_ClearArray()) {
  1320         memnode_worklist.append_if_missing(use);
  1321       } else if(use->is_Mem() && use->in(MemNode::Memory) == n) {
  1322         if (use->Opcode() == Op_StoreCM) // Ignore cardmark stores
  1323           continue;
  1324         memnode_worklist.append_if_missing(use);
  1325       } else if (use->is_MemBar()) {
  1326         memnode_worklist.append_if_missing(use);
  1327 #ifdef ASSERT
  1328       } else if(use->is_Mem()) {
  1329         assert(use->in(MemNode::Memory) != n, "EA: missing memory path");
  1330       } else if (use->is_MergeMem()) {
  1331         assert(_mergemem_worklist.contains(use->as_MergeMem()), "EA: missing MergeMem node in the worklist");
  1332       } else {
  1333         uint op = use->Opcode();
  1334         if (!(op == Op_StoreCM ||
  1335               (op == Op_CallLeaf && use->as_CallLeaf()->_name != NULL &&
  1336                strcmp(use->as_CallLeaf()->_name, "g1_wb_pre") == 0) ||
  1337               op == Op_AryEq || op == Op_StrComp ||
  1338               op == Op_StrEquals || op == Op_StrIndexOf)) {
  1339           n->dump();
  1340           use->dump();
  1341           assert(false, "EA: missing memory path");
  1343 #endif
  1348   //  Phase 3:  Process MergeMem nodes from mergemem_worklist.
  1349   //            Walk each memory slice moving the first node encountered of each
  1350   //            instance type to the the input corresponding to its alias index.
  1351   uint length = _mergemem_worklist.length();
  1352   for( uint next = 0; next < length; ++next ) {
  1353     MergeMemNode* nmm = _mergemem_worklist.at(next);
  1354     assert(!visited.test_set(nmm->_idx), "should not be visited before");
  1355     // Note: we don't want to use MergeMemStream here because we only want to
  1356     // scan inputs which exist at the start, not ones we add during processing.
  1357     // Note 2: MergeMem may already contains instance memory slices added
  1358     // during find_inst_mem() call when memory nodes were processed above.
  1359     igvn->hash_delete(nmm);
  1360     uint nslices = nmm->req();
  1361     for (uint i = Compile::AliasIdxRaw+1; i < nslices; i++) {
  1362       Node* mem = nmm->in(i);
  1363       Node* cur = NULL;
  1364       if (mem == NULL || mem->is_top())
  1365         continue;
  1366       // First, update mergemem by moving memory nodes to corresponding slices
  1367       // if their type became more precise since this mergemem was created.
  1368       while (mem->is_Mem()) {
  1369         const Type *at = igvn->type(mem->in(MemNode::Address));
  1370         if (at != Type::TOP) {
  1371           assert (at->isa_ptr() != NULL, "pointer type required.");
  1372           uint idx = (uint)_compile->get_alias_index(at->is_ptr());
  1373           if (idx == i) {
  1374             if (cur == NULL)
  1375               cur = mem;
  1376           } else {
  1377             if (idx >= nmm->req() || nmm->is_empty_memory(nmm->in(idx))) {
  1378               nmm->set_memory_at(idx, mem);
  1382         mem = mem->in(MemNode::Memory);
  1384       nmm->set_memory_at(i, (cur != NULL) ? cur : mem);
  1385       // Find any instance of the current type if we haven't encountered
  1386       // already a memory slice of the instance along the memory chain.
  1387       for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1388         if((uint)_compile->get_general_index(ni) == i) {
  1389           Node *m = (ni >= nmm->req()) ? nmm->empty_memory() : nmm->in(ni);
  1390           if (nmm->is_empty_memory(m)) {
  1391             Node* result = find_inst_mem(mem, ni, orig_phis, igvn);
  1392             if (_compile->failing()) {
  1393               return;
  1395             nmm->set_memory_at(ni, result);
  1400     // Find the rest of instances values
  1401     for (uint ni = new_index_start; ni < new_index_end; ni++) {
  1402       const TypeOopPtr *tinst = _compile->get_adr_type(ni)->isa_oopptr();
  1403       Node* result = step_through_mergemem(nmm, ni, tinst);
  1404       if (result == nmm->base_memory()) {
  1405         // Didn't find instance memory, search through general slice recursively.
  1406         result = nmm->memory_at(_compile->get_general_index(ni));
  1407         result = find_inst_mem(result, ni, orig_phis, igvn);
  1408         if (_compile->failing()) {
  1409           return;
  1411         nmm->set_memory_at(ni, result);
  1414     igvn->hash_insert(nmm);
  1415     record_for_optimizer(nmm);
  1418   //  Phase 4:  Update the inputs of non-instance memory Phis and
  1419   //            the Memory input of memnodes
  1420   // First update the inputs of any non-instance Phi's from
  1421   // which we split out an instance Phi.  Note we don't have
  1422   // to recursively process Phi's encounted on the input memory
  1423   // chains as is done in split_memory_phi() since they  will
  1424   // also be processed here.
  1425   for (int j = 0; j < orig_phis.length(); j++) {
  1426     PhiNode *phi = orig_phis.at(j);
  1427     int alias_idx = _compile->get_alias_index(phi->adr_type());
  1428     igvn->hash_delete(phi);
  1429     for (uint i = 1; i < phi->req(); i++) {
  1430       Node *mem = phi->in(i);
  1431       Node *new_mem = find_inst_mem(mem, alias_idx, orig_phis, igvn);
  1432       if (_compile->failing()) {
  1433         return;
  1435       if (mem != new_mem) {
  1436         phi->set_req(i, new_mem);
  1439     igvn->hash_insert(phi);
  1440     record_for_optimizer(phi);
  1443   // Update the memory inputs of MemNodes with the value we computed
  1444   // in Phase 2 and move stores memory users to corresponding memory slices.
  1446   // Disable memory split verification code until the fix for 6984348.
  1447   // Currently it produces false negative results since it does not cover all cases.
  1448 #if 0 // ifdef ASSERT
  1449   visited.Reset();
  1450   Node_Stack old_mems(arena, _compile->unique() >> 2);
  1451 #endif
  1452   for (uint i = 0; i < nodes_size(); i++) {
  1453     Node *nmem = get_map(i);
  1454     if (nmem != NULL) {
  1455       Node *n = ptnode_adr(i)->_node;
  1456       assert(n != NULL, "sanity");
  1457       if (n->is_Mem()) {
  1458 #if 0 // ifdef ASSERT
  1459         Node* old_mem = n->in(MemNode::Memory);
  1460         if (!visited.test_set(old_mem->_idx)) {
  1461           old_mems.push(old_mem, old_mem->outcnt());
  1463 #endif
  1464         assert(n->in(MemNode::Memory) != nmem, "sanity");
  1465         if (!n->is_Load()) {
  1466           // Move memory users of a store first.
  1467           move_inst_mem(n, orig_phis, igvn);
  1469         // Now update memory input
  1470         igvn->hash_delete(n);
  1471         n->set_req(MemNode::Memory, nmem);
  1472         igvn->hash_insert(n);
  1473         record_for_optimizer(n);
  1474       } else {
  1475         assert(n->is_Allocate() || n->is_CheckCastPP() ||
  1476                n->is_AddP() || n->is_Phi(), "unknown node used for set_map()");
  1480 #if 0 // ifdef ASSERT
  1481   // Verify that memory was split correctly
  1482   while (old_mems.is_nonempty()) {
  1483     Node* old_mem = old_mems.node();
  1484     uint  old_cnt = old_mems.index();
  1485     old_mems.pop();
  1486     assert(old_cnt == old_mem->outcnt(), "old mem could be lost");
  1488 #endif
  1491 bool ConnectionGraph::has_candidates(Compile *C) {
  1492   // EA brings benefits only when the code has allocations and/or locks which
  1493   // are represented by ideal Macro nodes.
  1494   int cnt = C->macro_count();
  1495   for( int i=0; i < cnt; i++ ) {
  1496     Node *n = C->macro_node(i);
  1497     if ( n->is_Allocate() )
  1498       return true;
  1499     if( n->is_Lock() ) {
  1500       Node* obj = n->as_Lock()->obj_node()->uncast();
  1501       if( !(obj->is_Parm() || obj->is_Con()) )
  1502         return true;
  1505   return false;
  1508 void ConnectionGraph::do_analysis(Compile *C, PhaseIterGVN *igvn) {
  1509   // Add ConP#NULL and ConN#NULL nodes before ConnectionGraph construction
  1510   // to create space for them in ConnectionGraph::_nodes[].
  1511   Node* oop_null = igvn->zerocon(T_OBJECT);
  1512   Node* noop_null = igvn->zerocon(T_NARROWOOP);
  1514   ConnectionGraph* congraph = new(C->comp_arena()) ConnectionGraph(C, igvn);
  1515   // Perform escape analysis
  1516   if (congraph->compute_escape()) {
  1517     // There are non escaping objects.
  1518     C->set_congraph(congraph);
  1521   // Cleanup.
  1522   if (oop_null->outcnt() == 0)
  1523     igvn->hash_delete(oop_null);
  1524   if (noop_null->outcnt() == 0)
  1525     igvn->hash_delete(noop_null);
  1528 bool ConnectionGraph::compute_escape() {
  1529   Compile* C = _compile;
  1531   // 1. Populate Connection Graph (CG) with Ideal nodes.
  1533   Unique_Node_List worklist_init;
  1534   worklist_init.map(C->unique(), NULL);  // preallocate space
  1536   // Initialize worklist
  1537   if (C->root() != NULL) {
  1538     worklist_init.push(C->root());
  1541   GrowableArray<Node*> alloc_worklist;
  1542   GrowableArray<Node*> addp_worklist;
  1543   PhaseGVN* igvn = _igvn;
  1544   bool has_allocations = false;
  1546   // Push all useful nodes onto CG list and set their type.
  1547   for( uint next = 0; next < worklist_init.size(); ++next ) {
  1548     Node* n = worklist_init.at(next);
  1549     record_for_escape_analysis(n, igvn);
  1550     // Only allocations and java static calls results are checked
  1551     // for an escape status. See process_call_result() below.
  1552     if (n->is_Allocate() || n->is_CallStaticJava() &&
  1553         ptnode_adr(n->_idx)->node_type() == PointsToNode::JavaObject) {
  1554       has_allocations = true;
  1555       if (n->is_Allocate())
  1556         alloc_worklist.append(n);
  1558     if(n->is_AddP()) {
  1559       // Collect address nodes. Use them during stage 3 below
  1560       // to build initial connection graph field edges.
  1561       addp_worklist.append(n);
  1562     } else if (n->is_MergeMem()) {
  1563       // Collect all MergeMem nodes to add memory slices for
  1564       // scalar replaceable objects in split_unique_types().
  1565       _mergemem_worklist.append(n->as_MergeMem());
  1567     for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1568       Node* m = n->fast_out(i);   // Get user
  1569       worklist_init.push(m);
  1573   if (!has_allocations) {
  1574     _collecting = false;
  1575     return false; // Nothing to do.
  1578   // 2. First pass to create simple CG edges (doesn't require to walk CG).
  1579   uint delayed_size = _delayed_worklist.size();
  1580   for( uint next = 0; next < delayed_size; ++next ) {
  1581     Node* n = _delayed_worklist.at(next);
  1582     build_connection_graph(n, igvn);
  1585   // 3. Pass to create initial fields edges (JavaObject -F-> AddP)
  1586   //    to reduce number of iterations during stage 4 below.
  1587   uint addp_length = addp_worklist.length();
  1588   for( uint next = 0; next < addp_length; ++next ) {
  1589     Node* n = addp_worklist.at(next);
  1590     Node* base = get_addp_base(n);
  1591     if (base->is_Proj())
  1592       base = base->in(0);
  1593     PointsToNode::NodeType nt = ptnode_adr(base->_idx)->node_type();
  1594     if (nt == PointsToNode::JavaObject) {
  1595       build_connection_graph(n, igvn);
  1599   GrowableArray<int> cg_worklist;
  1600   cg_worklist.append(_phantom_object);
  1601   GrowableArray<uint>  worklist;
  1603   // 4. Build Connection Graph which need
  1604   //    to walk the connection graph.
  1605   _progress = false;
  1606   for (uint ni = 0; ni < nodes_size(); ni++) {
  1607     PointsToNode* ptn = ptnode_adr(ni);
  1608     Node *n = ptn->_node;
  1609     if (n != NULL) { // Call, AddP, LoadP, StoreP
  1610       build_connection_graph(n, igvn);
  1611       if (ptn->node_type() != PointsToNode::UnknownType)
  1612         cg_worklist.append(n->_idx); // Collect CG nodes
  1613       if (!_processed.test(n->_idx))
  1614         worklist.append(n->_idx); // Collect C/A/L/S nodes
  1618   // After IGVN user nodes may have smaller _idx than
  1619   // their inputs so they will be processed first in
  1620   // previous loop. Because of that not all Graph
  1621   // edges will be created. Walk over interesting
  1622   // nodes again until no new edges are created.
  1623   //
  1624   // Normally only 1-3 passes needed to build
  1625   // Connection Graph depending on graph complexity.
  1626   // Observed 8 passes in jvm2008 compiler.compiler.
  1627   // Set limit to 20 to catch situation when something
  1628   // did go wrong and recompile the method without EA.
  1630 #define CG_BUILD_ITER_LIMIT 20
  1632   uint length = worklist.length();
  1633   int iterations = 0;
  1634   while(_progress && (iterations++ < CG_BUILD_ITER_LIMIT)) {
  1635     _progress = false;
  1636     for( uint next = 0; next < length; ++next ) {
  1637       int ni = worklist.at(next);
  1638       PointsToNode* ptn = ptnode_adr(ni);
  1639       Node* n = ptn->_node;
  1640       assert(n != NULL, "should be known node");
  1641       build_connection_graph(n, igvn);
  1644   if (iterations >= CG_BUILD_ITER_LIMIT) {
  1645     assert(iterations < CG_BUILD_ITER_LIMIT,
  1646            err_msg("infinite EA connection graph build with %d nodes and worklist size %d",
  1647            nodes_size(), length));
  1648     // Possible infinite build_connection_graph loop,
  1649     // retry compilation without escape analysis.
  1650     C->record_failure(C2Compiler::retry_no_escape_analysis());
  1651     _collecting = false;
  1652     return false;
  1654 #undef CG_BUILD_ITER_LIMIT
  1656   Arena* arena = Thread::current()->resource_area();
  1657   VectorSet visited(arena);
  1659   // 5. Find fields initializing values for not escaped allocations
  1660   uint alloc_length = alloc_worklist.length();
  1661   for (uint next = 0; next < alloc_length; ++next) {
  1662     Node* n = alloc_worklist.at(next);
  1663     if (ptnode_adr(n->_idx)->escape_state() == PointsToNode::NoEscape) {
  1664       find_init_values(n, &visited, igvn);
  1668   worklist.clear();
  1670   // 6. Remove deferred edges from the graph.
  1671   uint cg_length = cg_worklist.length();
  1672   for (uint next = 0; next < cg_length; ++next) {
  1673     int ni = cg_worklist.at(next);
  1674     PointsToNode* ptn = ptnode_adr(ni);
  1675     PointsToNode::NodeType nt = ptn->node_type();
  1676     if (nt == PointsToNode::LocalVar || nt == PointsToNode::Field) {
  1677       remove_deferred(ni, &worklist, &visited);
  1678       Node *n = ptn->_node;
  1682   // 7. Adjust escape state of nonescaping objects.
  1683   for (uint next = 0; next < addp_length; ++next) {
  1684     Node* n = addp_worklist.at(next);
  1685     adjust_escape_state(n);
  1688   // 8. Propagate escape states.
  1689   worklist.clear();
  1691   // mark all nodes reachable from GlobalEscape nodes
  1692   (void)propagate_escape_state(&cg_worklist, &worklist, PointsToNode::GlobalEscape);
  1694   // mark all nodes reachable from ArgEscape nodes
  1695   bool has_non_escaping_obj = propagate_escape_state(&cg_worklist, &worklist, PointsToNode::ArgEscape);
  1697   // push all NoEscape nodes on the worklist
  1698   for( uint next = 0; next < cg_length; ++next ) {
  1699     int nk = cg_worklist.at(next);
  1700     if (ptnode_adr(nk)->escape_state() == PointsToNode::NoEscape)
  1701       worklist.push(nk);
  1703   alloc_worklist.clear();
  1704   // mark all nodes reachable from NoEscape nodes
  1705   while(worklist.length() > 0) {
  1706     uint nk = worklist.pop();
  1707     PointsToNode* ptn = ptnode_adr(nk);
  1708     if (ptn->node_type() == PointsToNode::JavaObject &&
  1709         !(nk == _noop_null || nk == _oop_null))
  1710       has_non_escaping_obj = true; // Non Escape
  1711     Node* n = ptn->_node;
  1712     bool scalar_replaceable = ptn->scalar_replaceable();
  1713     if (n->is_Allocate() && scalar_replaceable) {
  1714       // Push scalar replaceable allocations on alloc_worklist
  1715       // for processing in split_unique_types(). Note,
  1716       // following code may change scalar_replaceable value.
  1717       alloc_worklist.append(n);
  1719     uint e_cnt = ptn->edge_count();
  1720     for (uint ei = 0; ei < e_cnt; ei++) {
  1721       uint npi = ptn->edge_target(ei);
  1722       PointsToNode *np = ptnode_adr(npi);
  1723       if (np->escape_state() < PointsToNode::NoEscape) {
  1724         set_escape_state(npi, PointsToNode::NoEscape);
  1725         if (!scalar_replaceable) {
  1726           np->set_scalar_replaceable(false);
  1728         worklist.push(npi);
  1729       } else if (np->scalar_replaceable() && !scalar_replaceable) {
  1730         // Propagate scalar_replaceable value.
  1731         np->set_scalar_replaceable(false);
  1732         worklist.push(npi);
  1737   _collecting = false;
  1738   assert(C->unique() == nodes_size(), "there should be no new ideal nodes during ConnectionGraph build");
  1740   assert(ptnode_adr(_oop_null)->escape_state() == PointsToNode::NoEscape, "sanity");
  1741   if (UseCompressedOops) {
  1742     assert(ptnode_adr(_noop_null)->escape_state() == PointsToNode::NoEscape, "sanity");
  1745   if (EliminateLocks && has_non_escaping_obj) {
  1746     // Mark locks before changing ideal graph.
  1747     int cnt = C->macro_count();
  1748     for( int i=0; i < cnt; i++ ) {
  1749       Node *n = C->macro_node(i);
  1750       if (n->is_AbstractLock()) { // Lock and Unlock nodes
  1751         AbstractLockNode* alock = n->as_AbstractLock();
  1752         if (!alock->is_eliminated()) {
  1753           PointsToNode::EscapeState es = escape_state(alock->obj_node());
  1754           assert(es != PointsToNode::UnknownEscape, "should know");
  1755           if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
  1756             // Mark it eliminated
  1757             alock->set_eliminated();
  1764 #ifndef PRODUCT
  1765   if (PrintEscapeAnalysis) {
  1766     dump(); // Dump ConnectionGraph
  1768 #endif
  1770   bool has_scalar_replaceable_candidates = false;
  1771   alloc_length = alloc_worklist.length();
  1772   for (uint next = 0; next < alloc_length; ++next) {
  1773     Node* n = alloc_worklist.at(next);
  1774     PointsToNode* ptn = ptnode_adr(n->_idx);
  1775     assert(ptn->escape_state() == PointsToNode::NoEscape, "sanity");
  1776     if (ptn->scalar_replaceable()) {
  1777       has_scalar_replaceable_candidates = true;
  1778       break;
  1782   if ( has_scalar_replaceable_candidates &&
  1783        C->AliasLevel() >= 3 && EliminateAllocations ) {
  1785     // Now use the escape information to create unique types for
  1786     // scalar replaceable objects.
  1787     split_unique_types(alloc_worklist);
  1789     if (C->failing())  return false;
  1791     C->print_method("After Escape Analysis", 2);
  1793 #ifdef ASSERT
  1794   } else if (Verbose && (PrintEscapeAnalysis || PrintEliminateAllocations)) {
  1795     tty->print("=== No allocations eliminated for ");
  1796     C->method()->print_short_name();
  1797     if(!EliminateAllocations) {
  1798       tty->print(" since EliminateAllocations is off ===");
  1799     } else if(!has_scalar_replaceable_candidates) {
  1800       tty->print(" since there are no scalar replaceable candidates ===");
  1801     } else if(C->AliasLevel() < 3) {
  1802       tty->print(" since AliasLevel < 3 ===");
  1804     tty->cr();
  1805 #endif
  1807   return has_non_escaping_obj;
  1810 // Find fields initializing values for allocations.
  1811 void ConnectionGraph::find_init_values(Node* alloc, VectorSet* visited, PhaseTransform* phase) {
  1812   assert(alloc->is_Allocate(), "Should be called for Allocate nodes only");
  1813   PointsToNode* pta = ptnode_adr(alloc->_idx);
  1814   assert(pta->escape_state() == PointsToNode::NoEscape, "Not escaped Allocate nodes only");
  1815   InitializeNode* ini = alloc->as_Allocate()->initialization();
  1817   Compile* C = _compile;
  1818   visited->Reset();
  1819   // Check if a oop field's initializing value is recorded and add
  1820   // a corresponding NULL field's value if it is not recorded.
  1821   // Connection Graph does not record a default initialization by NULL
  1822   // captured by Initialize node.
  1823   //
  1824   uint ae_cnt = pta->edge_count();
  1825   for (uint ei = 0; ei < ae_cnt; ei++) {
  1826     uint nidx = pta->edge_target(ei); // Field (AddP)
  1827     PointsToNode* ptn = ptnode_adr(nidx);
  1828     assert(ptn->_node->is_AddP(), "Should be AddP nodes only");
  1829     int offset = ptn->offset();
  1830     if (offset != Type::OffsetBot &&
  1831         offset != oopDesc::klass_offset_in_bytes() &&
  1832         !visited->test_set(offset)) {
  1834       // Check only oop fields.
  1835       const Type* adr_type = ptn->_node->as_AddP()->bottom_type();
  1836       BasicType basic_field_type = T_INT;
  1837       if (adr_type->isa_instptr()) {
  1838         ciField* field = C->alias_type(adr_type->isa_instptr())->field();
  1839         if (field != NULL) {
  1840           basic_field_type = field->layout_type();
  1841         } else {
  1842           // Ignore non field load (for example, klass load)
  1844       } else if (adr_type->isa_aryptr()) {
  1845         if (offset != arrayOopDesc::length_offset_in_bytes()) {
  1846           const Type* elemtype = adr_type->isa_aryptr()->elem();
  1847           basic_field_type = elemtype->array_element_basic_type();
  1848         } else {
  1849           // Ignore array length load
  1851 #ifdef ASSERT
  1852       } else {
  1853         // Raw pointers are used for initializing stores so skip it
  1854         // since it should be recorded already
  1855         Node* base = get_addp_base(ptn->_node);
  1856         assert(adr_type->isa_rawptr() && base->is_Proj() &&
  1857                (base->in(0) == alloc),"unexpected pointer type");
  1858 #endif
  1860       if (basic_field_type == T_OBJECT ||
  1861           basic_field_type == T_NARROWOOP ||
  1862           basic_field_type == T_ARRAY) {
  1863         Node* value = NULL;
  1864         if (ini != NULL) {
  1865           BasicType ft = UseCompressedOops ? T_NARROWOOP : T_OBJECT;
  1866           Node* store = ini->find_captured_store(offset, type2aelembytes(ft), phase);
  1867           if (store != NULL && store->is_Store()) {
  1868             value = store->in(MemNode::ValueIn);
  1869           } else if (ptn->edge_count() > 0) { // Are there oop stores?
  1870             // Check for a store which follows allocation without branches.
  1871             // For example, a volatile field store is not collected
  1872             // by Initialize node. TODO: it would be nice to use idom() here.
  1873             //
  1874             // Search all references to the same field which use different
  1875             // AddP nodes, for example, in the next case:
  1876             //
  1877             //    Point p[] = new Point[1];
  1878             //    if ( x ) { p[0] = new Point(); p[0].x = x; }
  1879             //    if ( p[0] != null ) { y = p[0].x; } // has CastPP
  1880             //
  1881             for (uint next = ei; (next < ae_cnt) && (value == NULL); next++) {
  1882               uint fpi = pta->edge_target(next); // Field (AddP)
  1883               PointsToNode *ptf = ptnode_adr(fpi);
  1884               if (ptf->offset() == offset) {
  1885                 Node* nf = ptf->_node;
  1886                 for (DUIterator_Fast imax, i = nf->fast_outs(imax); i < imax; i++) {
  1887                   store = nf->fast_out(i);
  1888                   if (store->is_Store() && store->in(0) != NULL) {
  1889                     Node* ctrl = store->in(0);
  1890                     while(!(ctrl == ini || ctrl == alloc || ctrl == NULL ||
  1891                             ctrl == C->root() || ctrl == C->top() || ctrl->is_Region() ||
  1892                             ctrl->is_IfTrue() || ctrl->is_IfFalse())) {
  1893                        ctrl = ctrl->in(0);
  1895                     if (ctrl == ini || ctrl == alloc) {
  1896                       value = store->in(MemNode::ValueIn);
  1897                       break;
  1905         if (value == NULL || value != ptnode_adr(value->_idx)->_node) {
  1906           // A field's initializing value was not recorded. Add NULL.
  1907           uint null_idx = UseCompressedOops ? _noop_null : _oop_null;
  1908           add_edge_from_fields(alloc->_idx, null_idx, offset);
  1915 // Adjust escape state after Connection Graph is built.
  1916 void ConnectionGraph::adjust_escape_state(Node* n) {
  1917   PointsToNode* ptn = ptnode_adr(n->_idx);
  1918   assert(n->is_AddP(), "Should be called for AddP nodes only");
  1919   // Search for objects which are not scalar replaceable
  1920   // and mark them to propagate the state to referenced objects.
  1921   //
  1923   int offset = ptn->offset();
  1924   Node* base = get_addp_base(n);
  1925   VectorSet* ptset = PointsTo(base);
  1926   int ptset_size = ptset->Size();
  1928   // An object is not scalar replaceable if the field which may point
  1929   // to it has unknown offset (unknown element of an array of objects).
  1930   //
  1932   if (offset == Type::OffsetBot) {
  1933     uint e_cnt = ptn->edge_count();
  1934     for (uint ei = 0; ei < e_cnt; ei++) {
  1935       uint npi = ptn->edge_target(ei);
  1936       ptnode_adr(npi)->set_scalar_replaceable(false);
  1940   // Currently an object is not scalar replaceable if a LoadStore node
  1941   // access its field since the field value is unknown after it.
  1942   //
  1943   bool has_LoadStore = false;
  1944   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  1945     Node *use = n->fast_out(i);
  1946     if (use->is_LoadStore()) {
  1947       has_LoadStore = true;
  1948       break;
  1951   // An object is not scalar replaceable if the address points
  1952   // to unknown field (unknown element for arrays, offset is OffsetBot).
  1953   //
  1954   // Or the address may point to more then one object. This may produce
  1955   // the false positive result (set not scalar replaceable)
  1956   // since the flow-insensitive escape analysis can't separate
  1957   // the case when stores overwrite the field's value from the case
  1958   // when stores happened on different control branches.
  1959   //
  1960   // Note: it will disable scalar replacement in some cases:
  1961   //
  1962   //    Point p[] = new Point[1];
  1963   //    p[0] = new Point(); // Will be not scalar replaced
  1964   //
  1965   // but it will save us from incorrect optimizations in next cases:
  1966   //
  1967   //    Point p[] = new Point[1];
  1968   //    if ( x ) p[0] = new Point(); // Will be not scalar replaced
  1969   //
  1970   if (ptset_size > 1 || ptset_size != 0 &&
  1971       (has_LoadStore || offset == Type::OffsetBot)) {
  1972     for( VectorSetI j(ptset); j.test(); ++j ) {
  1973       ptnode_adr(j.elem)->set_scalar_replaceable(false);
  1978 // Propagate escape states to referenced nodes.
  1979 bool ConnectionGraph::propagate_escape_state(GrowableArray<int>* cg_worklist,
  1980                                              GrowableArray<uint>* worklist,
  1981                                              PointsToNode::EscapeState esc_state) {
  1982   bool has_java_obj = false;
  1984   // push all nodes with the same escape state on the worklist
  1985   uint cg_length = cg_worklist->length();
  1986   for (uint next = 0; next < cg_length; ++next) {
  1987     int nk = cg_worklist->at(next);
  1988     if (ptnode_adr(nk)->escape_state() == esc_state)
  1989       worklist->push(nk);
  1991   // mark all reachable nodes
  1992   while (worklist->length() > 0) {
  1993     PointsToNode* ptn = ptnode_adr(worklist->pop());
  1994     if (ptn->node_type() == PointsToNode::JavaObject) {
  1995       has_java_obj = true;
  1997     uint e_cnt = ptn->edge_count();
  1998     for (uint ei = 0; ei < e_cnt; ei++) {
  1999       uint npi = ptn->edge_target(ei);
  2000       PointsToNode *np = ptnode_adr(npi);
  2001       if (np->escape_state() < esc_state) {
  2002         set_escape_state(npi, esc_state);
  2003         worklist->push(npi);
  2007   // Has not escaping java objects
  2008   return has_java_obj && (esc_state < PointsToNode::GlobalEscape);
  2011 void ConnectionGraph::process_call_arguments(CallNode *call, PhaseTransform *phase) {
  2013     switch (call->Opcode()) {
  2014 #ifdef ASSERT
  2015     case Op_Allocate:
  2016     case Op_AllocateArray:
  2017     case Op_Lock:
  2018     case Op_Unlock:
  2019       assert(false, "should be done already");
  2020       break;
  2021 #endif
  2022     case Op_CallLeaf:
  2023     case Op_CallLeafNoFP:
  2025       // Stub calls, objects do not escape but they are not scale replaceable.
  2026       // Adjust escape state for outgoing arguments.
  2027       const TypeTuple * d = call->tf()->domain();
  2028       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2029         const Type* at = d->field_at(i);
  2030         Node *arg = call->in(i)->uncast();
  2031         const Type *aat = phase->type(arg);
  2032         if (!arg->is_top() && at->isa_ptr() && aat->isa_ptr() &&
  2033             ptnode_adr(arg->_idx)->escape_state() < PointsToNode::ArgEscape) {
  2035           assert(aat == Type::TOP || aat == TypePtr::NULL_PTR ||
  2036                  aat->isa_ptr() != NULL, "expecting an Ptr");
  2037 #ifdef ASSERT
  2038           if (!(call->Opcode() == Op_CallLeafNoFP &&
  2039                 call->as_CallLeaf()->_name != NULL &&
  2040                 (strstr(call->as_CallLeaf()->_name, "arraycopy")  != 0) ||
  2041                 call->as_CallLeaf()->_name != NULL &&
  2042                 (strcmp(call->as_CallLeaf()->_name, "g1_wb_pre")  == 0 ||
  2043                  strcmp(call->as_CallLeaf()->_name, "g1_wb_post") == 0 ))
  2044           ) {
  2045             call->dump();
  2046             assert(false, "EA: unexpected CallLeaf");
  2048 #endif
  2049           set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  2050           if (arg->is_AddP()) {
  2051             //
  2052             // The inline_native_clone() case when the arraycopy stub is called
  2053             // after the allocation before Initialize and CheckCastPP nodes.
  2054             //
  2055             // Set AddP's base (Allocate) as not scalar replaceable since
  2056             // pointer to the base (with offset) is passed as argument.
  2057             //
  2058             arg = get_addp_base(arg);
  2060           for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2061             uint pt = j.elem;
  2062             set_escape_state(pt, PointsToNode::ArgEscape);
  2066       break;
  2069     case Op_CallStaticJava:
  2070     // For a static call, we know exactly what method is being called.
  2071     // Use bytecode estimator to record the call's escape affects
  2073       ciMethod *meth = call->as_CallJava()->method();
  2074       BCEscapeAnalyzer *call_analyzer = (meth !=NULL) ? meth->get_bcea() : NULL;
  2075       // fall-through if not a Java method or no analyzer information
  2076       if (call_analyzer != NULL) {
  2077         const TypeTuple * d = call->tf()->domain();
  2078         bool copy_dependencies = false;
  2079         for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2080           const Type* at = d->field_at(i);
  2081           int k = i - TypeFunc::Parms;
  2082           Node *arg = call->in(i)->uncast();
  2084           if (at->isa_oopptr() != NULL &&
  2085               ptnode_adr(arg->_idx)->escape_state() < PointsToNode::GlobalEscape) {
  2087             bool global_escapes = false;
  2088             bool fields_escapes = false;
  2089             if (!call_analyzer->is_arg_stack(k)) {
  2090               // The argument global escapes, mark everything it could point to
  2091               set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2092               global_escapes = true;
  2093             } else {
  2094               if (!call_analyzer->is_arg_local(k)) {
  2095                 // The argument itself doesn't escape, but any fields might
  2096                 fields_escapes = true;
  2098               set_escape_state(arg->_idx, PointsToNode::ArgEscape);
  2099               copy_dependencies = true;
  2102             for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2103               uint pt = j.elem;
  2104               if (global_escapes) {
  2105                 //The argument global escapes, mark everything it could point to
  2106                 set_escape_state(pt, PointsToNode::GlobalEscape);
  2107               } else {
  2108                 if (fields_escapes) {
  2109                   // The argument itself doesn't escape, but any fields might
  2110                   add_edge_from_fields(pt, _phantom_object, Type::OffsetBot);
  2112                 set_escape_state(pt, PointsToNode::ArgEscape);
  2117         if (copy_dependencies)
  2118           call_analyzer->copy_dependencies(_compile->dependencies());
  2119         break;
  2123     default:
  2124     // Fall-through here if not a Java method or no analyzer information
  2125     // or some other type of call, assume the worst case: all arguments
  2126     // globally escape.
  2128       // adjust escape state for  outgoing arguments
  2129       const TypeTuple * d = call->tf()->domain();
  2130       for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2131         const Type* at = d->field_at(i);
  2132         if (at->isa_oopptr() != NULL) {
  2133           Node *arg = call->in(i)->uncast();
  2134           set_escape_state(arg->_idx, PointsToNode::GlobalEscape);
  2135           for( VectorSetI j(PointsTo(arg)); j.test(); ++j ) {
  2136             uint pt = j.elem;
  2137             set_escape_state(pt, PointsToNode::GlobalEscape);
  2144 void ConnectionGraph::process_call_result(ProjNode *resproj, PhaseTransform *phase) {
  2145   CallNode   *call = resproj->in(0)->as_Call();
  2146   uint    call_idx = call->_idx;
  2147   uint resproj_idx = resproj->_idx;
  2149   switch (call->Opcode()) {
  2150     case Op_Allocate:
  2152       Node *k = call->in(AllocateNode::KlassNode);
  2153       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2154       assert(kt != NULL, "TypeKlassPtr  required.");
  2155       ciKlass* cik = kt->klass();
  2157       PointsToNode::EscapeState es;
  2158       uint edge_to;
  2159       if (cik->is_subclass_of(_compile->env()->Thread_klass()) ||
  2160          !cik->is_instance_klass() || // StressReflectiveCode
  2161           cik->as_instance_klass()->has_finalizer()) {
  2162         es = PointsToNode::GlobalEscape;
  2163         edge_to = _phantom_object; // Could not be worse
  2164       } else {
  2165         es = PointsToNode::NoEscape;
  2166         edge_to = call_idx;
  2167         assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
  2169       set_escape_state(call_idx, es);
  2170       add_pointsto_edge(resproj_idx, edge_to);
  2171       _processed.set(resproj_idx);
  2172       break;
  2175     case Op_AllocateArray:
  2178       Node *k = call->in(AllocateNode::KlassNode);
  2179       const TypeKlassPtr *kt = k->bottom_type()->isa_klassptr();
  2180       assert(kt != NULL, "TypeKlassPtr  required.");
  2181       ciKlass* cik = kt->klass();
  2183       PointsToNode::EscapeState es;
  2184       uint edge_to;
  2185       if (!cik->is_array_klass()) { // StressReflectiveCode
  2186         es = PointsToNode::GlobalEscape;
  2187         edge_to = _phantom_object;
  2188       } else {
  2189         es = PointsToNode::NoEscape;
  2190         edge_to = call_idx;
  2191         assert(ptnode_adr(call_idx)->scalar_replaceable(), "sanity");
  2192         int length = call->in(AllocateNode::ALength)->find_int_con(-1);
  2193         if (length < 0 || length > EliminateAllocationArraySizeLimit) {
  2194           // Not scalar replaceable if the length is not constant or too big.
  2195           ptnode_adr(call_idx)->set_scalar_replaceable(false);
  2198       set_escape_state(call_idx, es);
  2199       add_pointsto_edge(resproj_idx, edge_to);
  2200       _processed.set(resproj_idx);
  2201       break;
  2204     case Op_CallStaticJava:
  2205     // For a static call, we know exactly what method is being called.
  2206     // Use bytecode estimator to record whether the call's return value escapes
  2208       bool done = true;
  2209       const TypeTuple *r = call->tf()->range();
  2210       const Type* ret_type = NULL;
  2212       if (r->cnt() > TypeFunc::Parms)
  2213         ret_type = r->field_at(TypeFunc::Parms);
  2215       // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2216       //        _multianewarray functions return a TypeRawPtr.
  2217       if (ret_type == NULL || ret_type->isa_ptr() == NULL) {
  2218         _processed.set(resproj_idx);
  2219         break;  // doesn't return a pointer type
  2221       ciMethod *meth = call->as_CallJava()->method();
  2222       const TypeTuple * d = call->tf()->domain();
  2223       if (meth == NULL) {
  2224         // not a Java method, assume global escape
  2225         set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2226         add_pointsto_edge(resproj_idx, _phantom_object);
  2227       } else {
  2228         BCEscapeAnalyzer *call_analyzer = meth->get_bcea();
  2229         bool copy_dependencies = false;
  2231         if (call_analyzer->is_return_allocated()) {
  2232           // Returns a newly allocated unescaped object, simply
  2233           // update dependency information.
  2234           // Mark it as NoEscape so that objects referenced by
  2235           // it's fields will be marked as NoEscape at least.
  2236           set_escape_state(call_idx, PointsToNode::NoEscape);
  2237           ptnode_adr(call_idx)->set_scalar_replaceable(false);
  2238           add_pointsto_edge(resproj_idx, call_idx);
  2239           copy_dependencies = true;
  2240         } else if (call_analyzer->is_return_local()) {
  2241           // determine whether any arguments are returned
  2242           set_escape_state(call_idx, PointsToNode::ArgEscape);
  2243           bool ret_arg = false;
  2244           for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
  2245             const Type* at = d->field_at(i);
  2247             if (at->isa_oopptr() != NULL) {
  2248               Node *arg = call->in(i)->uncast();
  2250               if (call_analyzer->is_arg_returned(i - TypeFunc::Parms)) {
  2251                 ret_arg = true;
  2252                 PointsToNode *arg_esp = ptnode_adr(arg->_idx);
  2253                 if (arg_esp->node_type() == PointsToNode::UnknownType)
  2254                   done = false;
  2255                 else if (arg_esp->node_type() == PointsToNode::JavaObject)
  2256                   add_pointsto_edge(resproj_idx, arg->_idx);
  2257                 else
  2258                   add_deferred_edge(resproj_idx, arg->_idx);
  2262           if (done && !ret_arg) {
  2263             // Returns unknown object.
  2264             set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2265             add_pointsto_edge(resproj_idx, _phantom_object);
  2267           if (done) {
  2268             copy_dependencies = true;
  2270         } else {
  2271           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2272           add_pointsto_edge(resproj_idx, _phantom_object);
  2274         if (copy_dependencies)
  2275           call_analyzer->copy_dependencies(_compile->dependencies());
  2277       if (done)
  2278         _processed.set(resproj_idx);
  2279       break;
  2282     default:
  2283     // Some other type of call, assume the worst case that the
  2284     // returned value, if any, globally escapes.
  2286       const TypeTuple *r = call->tf()->range();
  2287       if (r->cnt() > TypeFunc::Parms) {
  2288         const Type* ret_type = r->field_at(TypeFunc::Parms);
  2290         // Note:  we use isa_ptr() instead of isa_oopptr()  here because the
  2291         //        _multianewarray functions return a TypeRawPtr.
  2292         if (ret_type->isa_ptr() != NULL) {
  2293           set_escape_state(call_idx, PointsToNode::GlobalEscape);
  2294           add_pointsto_edge(resproj_idx, _phantom_object);
  2297       _processed.set(resproj_idx);
  2302 // Populate Connection Graph with Ideal nodes and create simple
  2303 // connection graph edges (do not need to check the node_type of inputs
  2304 // or to call PointsTo() to walk the connection graph).
  2305 void ConnectionGraph::record_for_escape_analysis(Node *n, PhaseTransform *phase) {
  2306   if (_processed.test(n->_idx))
  2307     return; // No need to redefine node's state.
  2309   if (n->is_Call()) {
  2310     // Arguments to allocation and locking don't escape.
  2311     if (n->is_Allocate()) {
  2312       add_node(n, PointsToNode::JavaObject, PointsToNode::UnknownEscape, true);
  2313       record_for_optimizer(n);
  2314     } else if (n->is_Lock() || n->is_Unlock()) {
  2315       // Put Lock and Unlock nodes on IGVN worklist to process them during
  2316       // the first IGVN optimization when escape information is still available.
  2317       record_for_optimizer(n);
  2318       _processed.set(n->_idx);
  2319     } else {
  2320       // Don't mark as processed since call's arguments have to be processed.
  2321       PointsToNode::NodeType nt = PointsToNode::UnknownType;
  2322       PointsToNode::EscapeState es = PointsToNode::UnknownEscape;
  2324       // Check if a call returns an object.
  2325       const TypeTuple *r = n->as_Call()->tf()->range();
  2326       if (r->cnt() > TypeFunc::Parms &&
  2327           r->field_at(TypeFunc::Parms)->isa_ptr() &&
  2328           n->as_Call()->proj_out(TypeFunc::Parms) != NULL) {
  2329         nt = PointsToNode::JavaObject;
  2330         if (!n->is_CallStaticJava()) {
  2331           // Since the called mathod is statically unknown assume
  2332           // the worst case that the returned value globally escapes.
  2333           es = PointsToNode::GlobalEscape;
  2336       add_node(n, nt, es, false);
  2338     return;
  2341   // Using isa_ptr() instead of isa_oopptr() for LoadP and Phi because
  2342   // ThreadLocal has RawPrt type.
  2343   switch (n->Opcode()) {
  2344     case Op_AddP:
  2346       add_node(n, PointsToNode::Field, PointsToNode::UnknownEscape, false);
  2347       break;
  2349     case Op_CastX2P:
  2350     { // "Unsafe" memory access.
  2351       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2352       break;
  2354     case Op_CastPP:
  2355     case Op_CheckCastPP:
  2356     case Op_EncodeP:
  2357     case Op_DecodeN:
  2359       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2360       int ti = n->in(1)->_idx;
  2361       PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2362       if (nt == PointsToNode::UnknownType) {
  2363         _delayed_worklist.push(n); // Process it later.
  2364         break;
  2365       } else if (nt == PointsToNode::JavaObject) {
  2366         add_pointsto_edge(n->_idx, ti);
  2367       } else {
  2368         add_deferred_edge(n->_idx, ti);
  2370       _processed.set(n->_idx);
  2371       break;
  2373     case Op_ConP:
  2375       // assume all pointer constants globally escape except for null
  2376       PointsToNode::EscapeState es;
  2377       if (phase->type(n) == TypePtr::NULL_PTR)
  2378         es = PointsToNode::NoEscape;
  2379       else
  2380         es = PointsToNode::GlobalEscape;
  2382       add_node(n, PointsToNode::JavaObject, es, true);
  2383       break;
  2385     case Op_ConN:
  2387       // assume all narrow oop constants globally escape except for null
  2388       PointsToNode::EscapeState es;
  2389       if (phase->type(n) == TypeNarrowOop::NULL_PTR)
  2390         es = PointsToNode::NoEscape;
  2391       else
  2392         es = PointsToNode::GlobalEscape;
  2394       add_node(n, PointsToNode::JavaObject, es, true);
  2395       break;
  2397     case Op_CreateEx:
  2399       // assume that all exception objects globally escape
  2400       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2401       break;
  2403     case Op_LoadKlass:
  2404     case Op_LoadNKlass:
  2406       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, true);
  2407       break;
  2409     case Op_LoadP:
  2410     case Op_LoadN:
  2412       const Type *t = phase->type(n);
  2413       if (t->make_ptr() == NULL) {
  2414         _processed.set(n->_idx);
  2415         return;
  2417       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2418       break;
  2420     case Op_Parm:
  2422       _processed.set(n->_idx); // No need to redefine it state.
  2423       uint con = n->as_Proj()->_con;
  2424       if (con < TypeFunc::Parms)
  2425         return;
  2426       const Type *t = n->in(0)->as_Start()->_domain->field_at(con);
  2427       if (t->isa_ptr() == NULL)
  2428         return;
  2429       // We have to assume all input parameters globally escape
  2430       // (Note: passing 'false' since _processed is already set).
  2431       add_node(n, PointsToNode::JavaObject, PointsToNode::GlobalEscape, false);
  2432       break;
  2434     case Op_Phi:
  2436       const Type *t = n->as_Phi()->type();
  2437       if (t->make_ptr() == NULL) {
  2438         // nothing to do if not an oop or narrow oop
  2439         _processed.set(n->_idx);
  2440         return;
  2442       add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2443       uint i;
  2444       for (i = 1; i < n->req() ; i++) {
  2445         Node* in = n->in(i);
  2446         if (in == NULL)
  2447           continue;  // ignore NULL
  2448         in = in->uncast();
  2449         if (in->is_top() || in == n)
  2450           continue;  // ignore top or inputs which go back this node
  2451         int ti = in->_idx;
  2452         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2453         if (nt == PointsToNode::UnknownType) {
  2454           break;
  2455         } else if (nt == PointsToNode::JavaObject) {
  2456           add_pointsto_edge(n->_idx, ti);
  2457         } else {
  2458           add_deferred_edge(n->_idx, ti);
  2461       if (i >= n->req())
  2462         _processed.set(n->_idx);
  2463       else
  2464         _delayed_worklist.push(n);
  2465       break;
  2467     case Op_Proj:
  2469       // we are only interested in the oop result projection from a call
  2470       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2471         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2472         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2473         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2474           add_node(n, PointsToNode::LocalVar, PointsToNode::UnknownEscape, false);
  2475           int ti = n->in(0)->_idx;
  2476           // The call may not be registered yet (since not all its inputs are registered)
  2477           // if this is the projection from backbranch edge of Phi.
  2478           if (ptnode_adr(ti)->node_type() != PointsToNode::UnknownType) {
  2479             process_call_result(n->as_Proj(), phase);
  2481           if (!_processed.test(n->_idx)) {
  2482             // The call's result may need to be processed later if the call
  2483             // returns it's argument and the argument is not processed yet.
  2484             _delayed_worklist.push(n);
  2486           break;
  2489       _processed.set(n->_idx);
  2490       break;
  2492     case Op_Return:
  2494       if( n->req() > TypeFunc::Parms &&
  2495           phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2496         // Treat Return value as LocalVar with GlobalEscape escape state.
  2497         add_node(n, PointsToNode::LocalVar, PointsToNode::GlobalEscape, false);
  2498         int ti = n->in(TypeFunc::Parms)->_idx;
  2499         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2500         if (nt == PointsToNode::UnknownType) {
  2501           _delayed_worklist.push(n); // Process it later.
  2502           break;
  2503         } else if (nt == PointsToNode::JavaObject) {
  2504           add_pointsto_edge(n->_idx, ti);
  2505         } else {
  2506           add_deferred_edge(n->_idx, ti);
  2509       _processed.set(n->_idx);
  2510       break;
  2512     case Op_StoreP:
  2513     case Op_StoreN:
  2515       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2516       adr_type = adr_type->make_ptr();
  2517       if (adr_type->isa_oopptr()) {
  2518         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2519       } else {
  2520         Node* adr = n->in(MemNode::Address);
  2521         if (adr->is_AddP() && phase->type(adr) == TypeRawPtr::NOTNULL &&
  2522             adr->in(AddPNode::Address)->is_Proj() &&
  2523             adr->in(AddPNode::Address)->in(0)->is_Allocate()) {
  2524           add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2525           // We are computing a raw address for a store captured
  2526           // by an Initialize compute an appropriate address type.
  2527           int offs = (int)phase->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
  2528           assert(offs != Type::OffsetBot, "offset must be a constant");
  2529         } else {
  2530           _processed.set(n->_idx);
  2531           return;
  2534       break;
  2536     case Op_StorePConditional:
  2537     case Op_CompareAndSwapP:
  2538     case Op_CompareAndSwapN:
  2540       const Type *adr_type = phase->type(n->in(MemNode::Address));
  2541       adr_type = adr_type->make_ptr();
  2542       if (adr_type->isa_oopptr()) {
  2543         add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2544       } else {
  2545         _processed.set(n->_idx);
  2546         return;
  2548       break;
  2550     case Op_AryEq:
  2551     case Op_StrComp:
  2552     case Op_StrEquals:
  2553     case Op_StrIndexOf:
  2555       // char[] arrays passed to string intrinsics are not scalar replaceable.
  2556       add_node(n, PointsToNode::UnknownType, PointsToNode::UnknownEscape, false);
  2557       break;
  2559     case Op_ThreadLocal:
  2561       add_node(n, PointsToNode::JavaObject, PointsToNode::ArgEscape, true);
  2562       break;
  2564     default:
  2566       // nothing to do
  2568   return;
  2571 void ConnectionGraph::build_connection_graph(Node *n, PhaseTransform *phase) {
  2572   uint n_idx = n->_idx;
  2573   assert(ptnode_adr(n_idx)->_node != NULL, "node should be registered");
  2575   // Don't set processed bit for AddP, LoadP, StoreP since
  2576   // they may need more then one pass to process.
  2577   // Also don't mark as processed Call nodes since their
  2578   // arguments may need more then one pass to process.
  2579   if (_processed.test(n_idx))
  2580     return; // No need to redefine node's state.
  2582   if (n->is_Call()) {
  2583     CallNode *call = n->as_Call();
  2584     process_call_arguments(call, phase);
  2585     return;
  2588   switch (n->Opcode()) {
  2589     case Op_AddP:
  2591       Node *base = get_addp_base(n);
  2592       // Create a field edge to this node from everything base could point to.
  2593       for( VectorSetI i(PointsTo(base)); i.test(); ++i ) {
  2594         uint pt = i.elem;
  2595         add_field_edge(pt, n_idx, address_offset(n, phase));
  2597       break;
  2599     case Op_CastX2P:
  2601       assert(false, "Op_CastX2P");
  2602       break;
  2604     case Op_CastPP:
  2605     case Op_CheckCastPP:
  2606     case Op_EncodeP:
  2607     case Op_DecodeN:
  2609       int ti = n->in(1)->_idx;
  2610       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "all nodes should be registered");
  2611       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2612         add_pointsto_edge(n_idx, ti);
  2613       } else {
  2614         add_deferred_edge(n_idx, ti);
  2616       _processed.set(n_idx);
  2617       break;
  2619     case Op_ConP:
  2621       assert(false, "Op_ConP");
  2622       break;
  2624     case Op_ConN:
  2626       assert(false, "Op_ConN");
  2627       break;
  2629     case Op_CreateEx:
  2631       assert(false, "Op_CreateEx");
  2632       break;
  2634     case Op_LoadKlass:
  2635     case Op_LoadNKlass:
  2637       assert(false, "Op_LoadKlass");
  2638       break;
  2640     case Op_LoadP:
  2641     case Op_LoadN:
  2643       const Type *t = phase->type(n);
  2644 #ifdef ASSERT
  2645       if (t->make_ptr() == NULL)
  2646         assert(false, "Op_LoadP");
  2647 #endif
  2649       Node* adr = n->in(MemNode::Address)->uncast();
  2650       Node* adr_base;
  2651       if (adr->is_AddP()) {
  2652         adr_base = get_addp_base(adr);
  2653       } else {
  2654         adr_base = adr;
  2657       // For everything "adr_base" could point to, create a deferred edge from
  2658       // this node to each field with the same offset.
  2659       int offset = address_offset(adr, phase);
  2660       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
  2661         uint pt = i.elem;
  2662         add_deferred_edge_to_fields(n_idx, pt, offset);
  2664       break;
  2666     case Op_Parm:
  2668       assert(false, "Op_Parm");
  2669       break;
  2671     case Op_Phi:
  2673 #ifdef ASSERT
  2674       const Type *t = n->as_Phi()->type();
  2675       if (t->make_ptr() == NULL)
  2676         assert(false, "Op_Phi");
  2677 #endif
  2678       for (uint i = 1; i < n->req() ; i++) {
  2679         Node* in = n->in(i);
  2680         if (in == NULL)
  2681           continue;  // ignore NULL
  2682         in = in->uncast();
  2683         if (in->is_top() || in == n)
  2684           continue;  // ignore top or inputs which go back this node
  2685         int ti = in->_idx;
  2686         PointsToNode::NodeType nt = ptnode_adr(ti)->node_type();
  2687         assert(nt != PointsToNode::UnknownType, "all nodes should be known");
  2688         if (nt == PointsToNode::JavaObject) {
  2689           add_pointsto_edge(n_idx, ti);
  2690         } else {
  2691           add_deferred_edge(n_idx, ti);
  2694       _processed.set(n_idx);
  2695       break;
  2697     case Op_Proj:
  2699       // we are only interested in the oop result projection from a call
  2700       if (n->as_Proj()->_con == TypeFunc::Parms && n->in(0)->is_Call() ) {
  2701         assert(ptnode_adr(n->in(0)->_idx)->node_type() != PointsToNode::UnknownType,
  2702                "all nodes should be registered");
  2703         const TypeTuple *r = n->in(0)->as_Call()->tf()->range();
  2704         assert(r->cnt() > TypeFunc::Parms, "sanity");
  2705         if (r->field_at(TypeFunc::Parms)->isa_ptr() != NULL) {
  2706           process_call_result(n->as_Proj(), phase);
  2707           assert(_processed.test(n_idx), "all call results should be processed");
  2708           break;
  2711       assert(false, "Op_Proj");
  2712       break;
  2714     case Op_Return:
  2716 #ifdef ASSERT
  2717       if( n->req() <= TypeFunc::Parms ||
  2718           !phase->type(n->in(TypeFunc::Parms))->isa_oopptr() ) {
  2719         assert(false, "Op_Return");
  2721 #endif
  2722       int ti = n->in(TypeFunc::Parms)->_idx;
  2723       assert(ptnode_adr(ti)->node_type() != PointsToNode::UnknownType, "node should be registered");
  2724       if (ptnode_adr(ti)->node_type() == PointsToNode::JavaObject) {
  2725         add_pointsto_edge(n_idx, ti);
  2726       } else {
  2727         add_deferred_edge(n_idx, ti);
  2729       _processed.set(n_idx);
  2730       break;
  2732     case Op_StoreP:
  2733     case Op_StoreN:
  2734     case Op_StorePConditional:
  2735     case Op_CompareAndSwapP:
  2736     case Op_CompareAndSwapN:
  2738       Node *adr = n->in(MemNode::Address);
  2739       const Type *adr_type = phase->type(adr)->make_ptr();
  2740 #ifdef ASSERT
  2741       if (!adr_type->isa_oopptr())
  2742         assert(phase->type(adr) == TypeRawPtr::NOTNULL, "Op_StoreP");
  2743 #endif
  2745       assert(adr->is_AddP(), "expecting an AddP");
  2746       Node *adr_base = get_addp_base(adr);
  2747       Node *val = n->in(MemNode::ValueIn)->uncast();
  2748       // For everything "adr_base" could point to, create a deferred edge
  2749       // to "val" from each field with the same offset.
  2750       for( VectorSetI i(PointsTo(adr_base)); i.test(); ++i ) {
  2751         uint pt = i.elem;
  2752         add_edge_from_fields(pt, val->_idx, address_offset(adr, phase));
  2754       break;
  2756     case Op_AryEq:
  2757     case Op_StrComp:
  2758     case Op_StrEquals:
  2759     case Op_StrIndexOf:
  2761       // char[] arrays passed to string intrinsic do not escape but
  2762       // they are not scalar replaceable. Adjust escape state for them.
  2763       // Start from in(2) edge since in(1) is memory edge.
  2764       for (uint i = 2; i < n->req(); i++) {
  2765         Node* adr = n->in(i)->uncast();
  2766         const Type *at = phase->type(adr);
  2767         if (!adr->is_top() && at->isa_ptr()) {
  2768           assert(at == Type::TOP || at == TypePtr::NULL_PTR ||
  2769                  at->isa_ptr() != NULL, "expecting an Ptr");
  2770           if (adr->is_AddP()) {
  2771             adr = get_addp_base(adr);
  2773           // Mark as ArgEscape everything "adr" could point to.
  2774           set_escape_state(adr->_idx, PointsToNode::ArgEscape);
  2777       _processed.set(n_idx);
  2778       break;
  2780     case Op_ThreadLocal:
  2782       assert(false, "Op_ThreadLocal");
  2783       break;
  2785     default:
  2786       // This method should be called only for EA specific nodes.
  2787       ShouldNotReachHere();
  2791 #ifndef PRODUCT
  2792 void ConnectionGraph::dump() {
  2793   bool first = true;
  2795   uint size = nodes_size();
  2796   for (uint ni = 0; ni < size; ni++) {
  2797     PointsToNode *ptn = ptnode_adr(ni);
  2798     PointsToNode::NodeType ptn_type = ptn->node_type();
  2800     if (ptn_type != PointsToNode::JavaObject || ptn->_node == NULL)
  2801       continue;
  2802     PointsToNode::EscapeState es = escape_state(ptn->_node);
  2803     if (ptn->_node->is_Allocate() && (es == PointsToNode::NoEscape || Verbose)) {
  2804       if (first) {
  2805         tty->cr();
  2806         tty->print("======== Connection graph for ");
  2807         _compile->method()->print_short_name();
  2808         tty->cr();
  2809         first = false;
  2811       tty->print("%6d ", ni);
  2812       ptn->dump();
  2813       // Print all locals which reference this allocation
  2814       for (uint li = ni; li < size; li++) {
  2815         PointsToNode *ptn_loc = ptnode_adr(li);
  2816         PointsToNode::NodeType ptn_loc_type = ptn_loc->node_type();
  2817         if ( ptn_loc_type == PointsToNode::LocalVar && ptn_loc->_node != NULL &&
  2818              ptn_loc->edge_count() == 1 && ptn_loc->edge_target(0) == ni ) {
  2819           ptnode_adr(li)->dump(false);
  2822       if (Verbose) {
  2823         // Print all fields which reference this allocation
  2824         for (uint i = 0; i < ptn->edge_count(); i++) {
  2825           uint ei = ptn->edge_target(i);
  2826           ptnode_adr(ei)->dump(false);
  2829       tty->cr();
  2833 #endif

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